阅读说明：本技术 立体造形物及其制造方法 (Three-dimensional shaped object and method for producing same ) 是由 高桥秀树 于 2019-09-03 设计创作，主要内容包括：本发明提供立体造形物及其制造方法。该立体造形物,是由热塑性树脂构成的片状的基材在棱线处弯曲变形而成的,其特征在于,在至少上述棱线处的、上述基材的弯曲而成为外侧的面上覆盖有热膨胀层,该热膨胀层在被加热到上述热塑性树脂的热变形温度以上的情况下膨胀,上述热膨胀层在上述棱线处膨胀。(The invention provides a three-dimensional shaped object and a manufacturing method thereof. The three-dimensional object is formed by bending and deforming a sheet-like base material made of a thermoplastic resin at a ridge line, and is characterized in that at least the ridge line and the surface of the base material which becomes the outer side by bending are covered with a thermal expansion layer which expands when heated to a thermal deformation temperature of the thermoplastic resin or higher, and the thermal expansion layer expands at the ridge line.)

1. A three-dimensional shaped article comprising a sheet-like base material made of a thermoplastic resin and deformed by bending at a ridge line,

a thermally expandable layer covering at least the ridge line on the surface of the base material that is on the outside of the base material and is curved, the thermally expandable layer being expanded when heated to a temperature equal to or higher than the thermal deformation temperature of the thermoplastic resin,

the thermal expansion layer expands at the ridge line.

2. The stereomodeling object of claim 1,

the thermal expansion layer covers both sides of the base material,

the outer thermal expansion layer of the base material after bending expands more than the inner thermal expansion layer at the ridge line.

3. A stereomodeling object as claimed in claim 2,

the thermal expansion layer on one surface of the base material is thicker than the thermal expansion layer on the other surface except the ridge line.

4. The stereomodeling object of claim 1,

at least one of the surfaces of the ridge lines has a photothermal conversion component that converts absorbed light into heat and emits the heat.

5. The stereomodeling object of claim 1,

the above-mentioned base material transmits light,

a photothermal conversion component that converts absorbed light into heat and emits the heat is attached to the surface between the thermal expansion layer and the base material at the ridge line.

6. A stereomodeling object as claimed in claim 4,

an ink receiving layer is formed on the surface to which the photothermal conversion component is attached.

7. The stereomodeling object of claim 1,

the thicker the thickness of the ridge line is, the larger the bending of the base material is.

8. A method for manufacturing a three-dimensional shaped object is characterized in that,

the following steps are carried out:

a thermal expansion layer forming step of forming a thermal expansion layer that expands when heated to a predetermined temperature range, on a sheet-like base material made of a thermoplastic resin having a thermal deformation temperature of not more than the predetermined temperature range;

a printing step of drawing a line with a printing material containing a photothermal conversion component that converts absorbed light into heat and emits the heat, on the surface of at least one of the thermally-expansible sheets on which the thermally-expansible layer is formed in the thermally-expansible layer forming step; and

a light irradiation step of irradiating the side on which the line is drawn with light converted into heat by the photothermal conversion component,

in the light irradiation step, the thermal expansion layer directly below the thread is expanded, and the base material is bent at the thread with the expanded thermal expansion layer as an outer side.

9. The method of manufacturing a three-dimensional object according to claim 8,

the thermal expansion layer forming step of forming the thermal expansion layers on both surfaces of the base material,

in the light irradiation step, the thermally-expansible layers on both surfaces directly below the thread are expanded so as to have different expansion amounts from each other, and the thermally-expansible layers having a large expansion amount are set outside the thermally-expansible layers to cause bending at the thread.

10. The method of manufacturing a three-dimensional object as claimed in claim 9,

in the thermal expansion layer forming step, the thermal expansion layer is formed thicker on one surface of the base material than on the other surface.

11. The method of manufacturing a three-dimensional object according to claim 8,

a release layer forming step of forming a release layer between the base material and the thermal expansion layer before the thermal expansion layer forming step,

after the light irradiation step, a thermal expansion layer removing step of removing the thermal expansion layer by peeling the thermal expansion layer from the substrate with the peeling layer is performed.

12. The method of manufacturing a three-dimensional object according to claim 8,

the thicker the thickness of the wire is, the larger the base material is bent.

13. A method for manufacturing a three-dimensional shaped object, comprising the steps of:

a printing step of drawing a line with a printing material containing a photothermal conversion component that converts absorbed light into heat and emits the heat;

a thermal expansion layer forming step of forming a thermal expansion layer that expands when heated to a predetermined temperature range, on one surface of a sheet-like base material made of a thermoplastic resin and having a thermal deformation temperature of not more than the predetermined temperature range, the base material transmitting the light; and

a light irradiation step of irradiating the substrate side with light converted into heat by the photothermal conversion component,

in the printing step, the lines are drawn on the one surface of the base material or the surface of the thermal expansion layer on the side of the base material,

in the light irradiation step, the thermal expansion layer directly below the wire is expanded, and the base material is bent at the wire with the one surface being an outer side.

14. The method of manufacturing a three-dimensional object as claimed in claim 13,

an ink-receiving layer forming step of forming a receiving layer of the printing material, prior to the printing step,

in the printing step, the lines are drawn on the surface of the receiving layer.

15. The method of manufacturing a three-dimensional object as claimed in claim 14,

a release layer forming step of forming a release layer before the ink receiving layer forming step,

in the ink-receiving layer forming step, the receiving layer is formed on the release layer,

after the light irradiation step, an ink removal step of removing the receiving layer by peeling it off the release layer is performed.

16. The method of manufacturing a three-dimensional object as claimed in claim 14,

a release layer forming step of forming a release layer between the base material and the thermal expansion layer before the thermal expansion layer forming step,

after the light irradiation step, a thermal expansion layer removing step of removing the thermal expansion layer by peeling the thermal expansion layer from the substrate through the peeling layer is performed.

17. The method of manufacturing a three-dimensional object as claimed in claim 16,

before the light irradiation step, a cutting step of cutting the base material and processing the cut base material into a desired planar shape is performed.

18. The method of manufacturing a three-dimensional object as claimed in claim 17,

in the cutting step, the base material is cut so that a part of the outline of the planar shape remains, and the base material is cut so that the base material has 1 or more connecting portions which are connected from the part of the outline to the peripheral edge before the cutting step,

after or at the same time as the light irradiation step, the connecting portion of the base material is cut at the contour line.

19. The method of manufacturing a three-dimensional object as claimed in claim 18,

in the printing step, a line intersecting the connecting portion is drawn with the printing material,

in the light irradiation step, the connecting portion of the base material is melted and cut at the line crossing the connecting portion.

20. The method of manufacturing a three-dimensional object as claimed in claim 13,

the thicker the thickness of the wire is, the larger the base material is bent.

Technical Field

The present invention relates to a three-dimensional shaped article obtained by molding a sheet-like resin and a method for producing the same.

Background

Thermoplastic resins such as polyvinyl chloride (PVC) and polyethylene terephthalate (PET) are produced into containers and the like having desired three-dimensional shapes by stretching and bending a sheet or film-like member formed into a flat surface by a press molding method, a vacuum molding method, or the like (see, for example, patent documents 1 and 2). Further, because of its transparency, texture, and the like, it is molded into a box shape and used as a packaging container or the like (for example, see patent document 3).

Patent document 1: japanese patent No. 6166304

Patent document 2: japanese patent laid-open publication No. 2016-198969

Patent document 3: japanese patent No. 5963930

Since a die corresponding to the shape after forming is used for forming the sheet, the manufacturing cost is high in trial and production in a small amount in comparison with the number. In addition, if the period of manufacturing the mold is also included, it takes time from design to completion, and therefore, if the specification change is repeated in trial work, time and cost increase. In the bending process, although a manual work using a ruler or the like is possible, once the sheet is bent, a fold remains in the sheet, and therefore, the sheet cannot be reworked, and accuracy is required. Further, it is difficult to stop the fold line at a desired position without folding the sheet to the end of the sheet, and to provide a curved fold line. Further, in a sheet having a high rigidity such as a certain thickness, cracks are likely to occur during bending, and even if 1-time bending is possible, the sheet may be broken at a fold line when a convex fold line is folded back into a concave fold line.

Disclosure of Invention

The present invention addresses the problem of providing a three-dimensional shaped article which can be produced appropriately and easily in a small amount of production and trial work and which is obtained by molding a sheet-like resin into a desired shape, and a method for producing the three-dimensional shaped article.

In order to solve the above problems, a three-dimensional shaped object of the present invention is a three-dimensional shaped object formed by bending and deforming a sheet-like base material made of a thermoplastic resin at ridges, wherein at least the ridges are covered with a thermal expansion layer on the surface of the base material that is bent to the outside, the thermal expansion layer expanding when heated to a thermal deformation temperature of the thermoplastic resin or higher, and the thermal expansion layer expanding at the ridges.

The method for producing a three-dimensional shaped object of the present invention is a method for producing a three-dimensional shaped object in which a sheet-like base material made of a thermoplastic resin is bent and deformed at a ridge line. The method for manufacturing the three-dimensional shaped object comprises the following steps: a thermal expansion layer forming step of forming a thermal expansion layer that expands when heated to a predetermined temperature range, on a sheet-like base material made of a thermoplastic resin having a thermal deformation temperature of not more than the predetermined temperature range; a printing step of drawing a line on at least one surface of the substrate with a printing material containing a photothermal conversion component for converting absorbed light into heat and releasing the converted heat; and a light irradiation step of irradiating the side on which the line is drawn with light converted into heat by the photothermal conversion component. In the light irradiation step, the thermal expansion layer directly below the thread is expanded, and the base material is bent at the thread with the expanded thermal expansion layer as an outer side. Alternatively, in the method for producing a three-dimensional shaped object of the present invention, the base material transmits light, and the following steps are performed: a printing step of drawing a line with the printing material; a thermal expansion layer forming step of forming a thermal expansion layer on one surface of the base material; and a light irradiation step of irradiating the substrate side with the light. In the printing step, the lines are drawn on the one surface of the base material or the surface of the thermal expansion layer on the base material side.

Effects of the invention

According to the three-dimensional shape of the present invention, a packaging container or the like having a desired shape can be easily obtained from a thermoplastic resin sheet. According to the method for producing a three-dimensional shaped object of the present invention, a thermoplastic resin sheet can be easily molded into a desired three-dimensional shape without preparing a mold.

Drawings

Fig. 1A is an external view of the three-dimensional object of the present invention.

Fig. 1B is a development view of the three-dimensional shaped object shown in fig. 1A, and is a plan view in a cutting step of the method for manufacturing the three-dimensional shaped object.

Fig. 2A is an external view of the three-dimensional object of the present invention.

Fig. 2B is a development view of the three-dimensional shaped object shown in fig. 2A, and is a plan view in a cutting step of the method for manufacturing the three-dimensional shaped object.

Fig. 3 is a partial sectional view schematically showing the structure of the three-dimensional shaped object according to embodiment 1 of the present invention.

Fig. 4 is a cross-sectional view schematically showing the structure of a thermally expandable layer-covered resin sheet as a material of the three-dimensional structure according to embodiment 1 of the present invention.

Fig. 5 is a cross-sectional view schematically illustrating a light irradiation device used for manufacturing a three-dimensional object.

Fig. 6 is a cross-sectional view schematically illustrating a light irradiation device used for manufacturing a three-dimensional object.

Fig. 7 is a flowchart showing a flow of the method for manufacturing a three-dimensional shaped object according to embodiment 1 of the present invention.

Fig. 8A is a schematic view illustrating a method for manufacturing a three-dimensional shaped object according to embodiment 1 of the present invention, and shows a cross-sectional view in a thermal expansion layer forming step.

Fig. 8B is a schematic view illustrating the method for producing a three-dimensional shaped object according to embodiment 1 of the present invention, and shows a cross-sectional view in the ink receiving layer forming step.

Fig. 8C is a schematic view illustrating the method for manufacturing a three-dimensional shaped object according to embodiment 1 of the present invention, and shows a cross-sectional view in the printing step.

Fig. 8D is a schematic view illustrating the method for producing a three-dimensional shaped object according to embodiment 1 of the present invention, and shows a cross-sectional view in the light irradiation step.

Fig. 9 is a schematic view illustrating a method for manufacturing a three-dimensional shaped object according to a modification of embodiment 1 of the present invention, and shows a plan view in a cutting step.

Fig. 10 is a partial sectional view schematically showing the structure of a three-dimensional shaped object according to a modification of embodiment 1 of the present invention.

Fig. 11 is a cross-sectional view schematically showing a structure in which a thermally expandable layer covering a resin sheet is used as a material of a three-dimensional structure according to a modification example of embodiment 1 of the present invention.

Fig. 12 is a cross-sectional view schematically showing a structure in which a thermally expandable layer covering a resin sheet is used as a material of a three-dimensional structure according to a modification example of embodiment 1 of the present invention.

Fig. 13A is a schematic view illustrating a method for manufacturing a three-dimensional shaped object according to a modification of embodiment 1 of the present invention, and shows a cross-sectional view in a printing step.

Fig. 13B is a schematic view illustrating a method for manufacturing a three-dimensional shaped object according to a modification of embodiment 1 of the present invention, and shows a cross-sectional view in a light irradiation step.

Fig. 14 is a flowchart showing a flow of the method for manufacturing a three-dimensional shaped object according to embodiment 2 of the present invention.

Fig. 15A is a schematic view illustrating a method for manufacturing a three-dimensional shaped object according to embodiment 2 of the present invention, and shows a cross-sectional view in a thermal expansion layer forming step.

Fig. 15B is a schematic view illustrating the method for manufacturing a three-dimensional shaped object according to embodiment 2 of the present invention, and shows a cross-sectional view in the printing step.

Fig. 15C is a schematic view illustrating the method for manufacturing a three-dimensional shaped object according to embodiment 2 of the present invention, and shows a cross-sectional view in the bonding step.

Fig. 15D is a schematic view illustrating the method for producing a three-dimensional shaped object according to embodiment 2 of the present invention, and shows a cross-sectional view in the light irradiation step.

Fig. 16A is an external view of the three-dimensional object of the present invention.

Fig. 16B is an expanded view of the three-dimensional shaping object shown in fig. 16A.

Fig. 17 is a partial sectional view schematically showing the structure of the three-dimensional shaped object according to embodiment 3 of the present invention.

Fig. 18 is a sectional view schematically showing the structure of a thermally expandable layer-covered resin sheet as a material of the three-dimensional structure according to embodiment 3 of the present invention.

Fig. 19 is a sectional view schematically illustrating a light irradiation device used for manufacturing a three-dimensional object.

Fig. 20A is a schematic view illustrating a method for manufacturing a three-dimensional shaped object according to embodiment 3 of the present invention, and shows a cross-sectional view in a printing step.

Fig. 20B is a schematic view illustrating the method for producing a three-dimensional shaped object according to embodiment 3 of the present invention, and shows a cross-sectional view in the light irradiation step.

Fig. 21 is a schematic view for explaining a method for manufacturing a three-dimensional shaped object according to a modification of embodiment 3 of the present invention, and shows a cross-sectional view in a printing step.

Fig. 22A is a schematic view illustrating a method for manufacturing a three-dimensional shaped object according to embodiment 4 of the present invention, and shows a cross-sectional view in a printing step.

Fig. 22B is a schematic view illustrating the method for producing a three-dimensional shaped object according to embodiment 4 of the present invention, and shows a cross-sectional view in the light irradiation step.

Fig. 23 is a cross-sectional view schematically showing a structure in which a thermally expandable layer covering a resin sheet is used as a material of a three-dimensional structure according to a modification example of embodiment 4 of the present invention.

Fig. 24 is a partial sectional view schematically showing the structure of a three-dimensional shaped object according to a modification example of embodiment 4 of the present invention.

Fig. 25 is a cross-sectional view schematically showing a structure in which a thermally expandable layer covering a resin sheet is used as a material of a three-dimensional structure according to a modification example of embodiment 4 of the present invention.

Fig. 26A is a schematic view illustrating a method for manufacturing a three-dimensional shaped object according to a modification example of embodiment 4 of the present invention, and shows a cross-sectional view in a printing step.

Fig. 26B is a schematic view illustrating a method for manufacturing a three-dimensional shaped object according to a modification example of embodiment 4 of the present invention, and shows a cross-sectional view in a light irradiation step.

Fig. 27 is an external view schematically illustrating a light irradiation device used for manufacturing a three-dimensional object.

Fig. 28 is a schematic view illustrating a method for manufacturing a three-dimensional shaped object according to embodiment 5 of the present invention, and shows a plan view in a cutting process.

Fig. 29 is a schematic view illustrating a method for manufacturing a three-dimensional shaped object according to embodiment 5 of the present invention, and shows a plan view in a cutting process.

Detailed Description

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. The following embodiments are illustrative of wiring boards and the like for embodying the technical idea of the present embodiment, and are not limited to the following. In the members shown in the drawings, the sizes, positional relationships, and the like may be exaggerated for clarity of the description, and the shapes may be simplified. In the following description, the same or similar members and steps are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

The structure of the three-dimensional shaped object of the present invention will be described with reference to fig. 1A, 1B, 2A, 2B, and 3. Fig. 1A and 2A are external views of the three-dimensional shaped object of the present invention, and fig. 1B and 2B are developed views of the three-dimensional shaped objects. Fig. 3 is a partial sectional view schematically showing the structure of the three-dimensional shaped object according to embodiment 1 of the present invention.

[ sheet molded article ]

As shown in fig. 1A, a sheet molded article (three-dimensional article) 11 is a box having a rectangular prism shape with a low profile, and is assembled by folding a flat plate-like sheet cut into a planar shape shown in fig. 1B with a solid line (photothermal conversion member 5) of the drawing as a fold line. In the present specification, the sheet molded article refers to an article formed by bending or curving a flat plate-like sheet having a uniform thickness to have a three-dimensional outer shape. The sheet material has rigidity and a certain degree of flexibility, and is provided with convex folds (or concave folds) at all fold lines. In the sheet molded article 11, a square in the center of fig. 1B is a bottom surface, rectangles continuous to 4 sides of the bottom surface are side surfaces, and a substantially triangular shape continuous to the side of each side surface facing the bottom surface constitutes a top surface (cover) with 4 surfaces. Further, a small quadrangle continuous with the other 1 side of each side face constitutes a flap (flap) folded toward the inner face side in order to avoid a gap from being generated between the flap and the adjacent side face. The sheet-shaped product 11 is bent at right angles at each fold line, and is fixed to the case by engaging substantially circular projections continuous with the apexes of substantially triangles constituting the 4 surfaces of the cover with each other.

As shown in fig. 2A, the sheet molded article (three-dimensional article) 12 is a so-called pillow-shaped case formed of a 4-sided curved surface (cylindrical surface), and is assembled by folding a flat plate-like sheet cut into a planar shape shown in fig. 2B with a solid line (photothermal conversion member 5) of the drawing as a fold line, similarly to the sheet molded article 11. The sheet molded article 12 includes a convex surface (bottom surface and top surface) of the opposing 2 surfaces curved so as to expand outward, and a concave surface (side surface) of the opposing 2 surfaces curved so as to recess inward. As shown in fig. 2B, the bottom surface and the top surface include straight 2 sides facing each other in parallel and arc-shaped 2 sides protruding inward, and are continuous with the straight 1 side. The overlap region (margin) 1m is continuous with the other 1 linear sides of the top surface, and a notch 1c is formed in the center of the 1 side. On the other hand, the claws corresponding to the length of the notch 1c are continuous with the center of the other linear side 1 of the bottom surface. The side surface is a leaf type (convex lens type) composed of 2 sides of an arc shape, the 2 sides of the arc shape are respectively continuous with the bottom surface and the top surface, and a semicircular notch is formed on the side surface of the bottom surface side to be used as a finger rest. The sheet molded article 12 is fixed in a tubular shape by folding the overlapping region 1m inward and inserting a claw into the notch 1c from the outside, and connecting the linear sides of the bottom surface and the top surface to each other. At this time, the side surface on the top surface side and the side surface on the bottom surface side are overlapped with each other. Since the sheet molded articles 11 and 12 are folded at the ridge lines and fixed in a three-dimensional shape without being stuck, they can be easily assembled by hand to form a packaging container such as a gift box.

[ 1 st embodiment ]

As shown in fig. 3, the sheet molded articles 11 and 12 (appropriately summarized as the sheet molded article 11) according to embodiment 1 of the present invention include a base material 1 and a thermally-expansible layer 2 laminated on the outer surface of the ridge line thereof, and the thermally-expansible layer 2 expands on the ridge line. The sheet molded article 11 of the present embodiment is manufactured from the thermal expansion layer-covered resin sheet 10 shown in fig. 4.

[ thermal expansion layer covering resin sheet ]

The structure of the thermal expansion layer-covered resin sheet 10 before the sheet molded article 11 is molded will be described below with reference to fig. 4. Fig. 4 is a cross-sectional view schematically showing the structure of a thermally expandable layer-covered resin sheet as a material of the three-dimensional structure according to embodiment 1 of the present invention. The thermal expansion layer-covering resin sheet 10 is a flat plate-like member having a uniform thickness, and is formed by sequentially laminating a base material 1, a thermal expansion layer 2, a release layer 31, and an ink receiving layer 4 each having a uniform thickness. The thermal expansion layer-coated resin sheet 10 is a printed material for printing black ink constituting the photothermal conversion member 5 on the ink receiving layer 4, which is the front surface. Therefore, the thermally-expansible layer-covering resin sheet 10 may have a size (a set size) corresponding to a printer for forming the photothermal conversion element 5 in the production of the sheet molded article 11, and may have a size equal to or larger than the developed shape (see fig. 1B and 2B) of the sheet molded article 11(12), for example, a3 paper size.

(substrate)

The base material 1 is a main element of the sheet molded product 11, and is a sheet-like member having rigidity for holding the shape of the sheet molded product 11 as a box and having flexibility. The base material 1 is flat before the sheet molded article 11 is molded (the thermal expansion layer covers the resin sheet 10), and the sheet molded article 11 has fold lines that are raised (or depressed) at all the ridge lines. The substrate 1 is made of a thermoplastic resin, and specifically, polyvinyl chloride (PVC), polyethylene terephthalate (PET), polypropylene (PP), and the like are used, and formed into a non-oriented film or a biaxially oriented film. The substrate 1 may contain a colorant such as a pigment to be colored in a desired color. The base material 1 is formed to have the above-described rigidity, and on the other hand, the thicker the base material, the more difficult it is to bend, and the lower the flexibility, the more difficult it is to form a curved surface. The base material 1 is preferably 0.2 to 0.5mm thick before molding so as to have appropriate rigidity and flexibility depending on the material.

(thermal expansion layer)

The thermally-expansible layer 2 is a member that expands when heated to a predetermined temperature range (expansion temperature range), and as described later, by locally expanding linearly in the process of producing the sheet molded article 11, a load is applied to the base material 1, and the base material plastically expandsDeforming it to bend it. The thermally expandable layer 2 is a thermally expandable microcapsule containing a thermally expandable microcapsule used in a known thermally expandable sheet, and is formed to have a uniform thickness t before molding the sheet molded article 11 (the thermally expandable layer covers the resin sheet 10) using a thermoplastic resin as a binder₀The film of (1). The thermal expansion layer 2 may contain a white pigment such as titanium oxide or a pigment other than black (not containing carbon black), and be colored in a desired color. The microcapsule is formed of a thermoplastic resin shell containing a volatile solvent, and expands to a magnitude corresponding to a heating temperature and further a heating time when heated to an expansion temperature range. The thermally-expansible layer 2 is expanded to about 10 times the volume before expansion at maximum, depending on the formulation of the microcapsule or the like. The lower limit of the expansion temperature range (expansion start temperature T) of the thermal expansion layer 2 can be set by selecting the thermoplastic resin and the volatile solvent in the microcapsule_Es) Suitably designed from a low temperature of about 70 c to a high temperature of approximately 300 c.

In the present invention, the thermal deformation temperature T of the thermoplastic resin constituting the substrate 1_DDesigned to be within or lower than the expansion temperature range of the thermal expansion layer 2, in the present embodiment, the expansion start temperature T of the thermal expansion layer 2 is preferably_EsHereinafter, it is more preferable that the temperature is less than the expansion start temperature T_Es. Further, the thermal deformation temperature T of the thermoplastic resin_DTemperatures at low loads are preferred. However, if the expansion start temperature T of the thermal expansion layer 2 is high_EsHeat distortion temperature T relative to the base material 1_DIf the temperature is too high, the substrate 1 and the thermally-expansible layer 2 are heated to the expansion temperature range, and if the temperature is too high, the substrate is excessively softened and thinned, and further melted to be perforated, cracked, or welded to the device. In addition, after the heating is completed and the progress of the expansion of the thermal expansion layer 2 is stopped by natural cooling or the like, the base material 1 may be subjected to unintended plastic deformation due to its own weight or the like. Specifically, the heating temperature (maximum temperature) set within the expansion temperature range of the thermal expansion layer 2, preferably the temperature at which the expansion rate of the microcapsules reaches the maximum (maximum expansion temperature T)_Emax) The base material 1 is smaller than the melting point if it is made of a crystalline resin, and is in a state of easily plastically deformed while maintaining the sheet (film) shape. Namely, as described later in the manufacturing methodAs described in the method, when heated to the same temperature, the base material 1 is bent by the load of expansion and deformation of the thermal expansion layer 2. Therefore, it is preferable to set the expansion temperature range for the thermal expansion layer 2 and to prepare the material in accordance with the thermal properties of the thermoplastic resin constituting the substrate 1.

Thermal expansion layer 2, thickness before forming (initial thickness) t₀The thicker the thickness, the larger the increase in volume (expansion amount) due to expansion, so that the load acting on the base material 1 due to deformation becomes high, and the base material 1 is likely to bend. On the other hand, the thermal expansion layer 2, if the initial thickness t is₀When the thickness is large, the amount of expansion is large, so that the expansion on the ridge line is large in the sheet molded article 11, the ridge line floats up to be conspicuous, and heat is less likely to propagate to the base material 1 in the process of producing the sheet molded article 11. Specifically, the initial thickness t of the thermal expansion layer 2₀Preferably 50 to 200 μm, and more preferably designed according to the thickness of the substrate 1.

The local expansion of the thermal expansion layer 2 is caused by local heating of the thermal expansion layer 2, and is performed by converting irradiated light and emitting heat by the photothermal conversion member 5 made of black ink attached to the surface of the thermal expansion layer-covering resin sheet 10, as described in the manufacturing method described later.

(peeling layer)

The release layer 31 is provided as needed, that is, is configured to be releasable from the thermal expansion layer 2 as a base thereof, in order to remove the photothermal conversion member 5 made of black ink printed linearly on the surface of the thermal expansion layer-coated resin sheet 10 together with the ink receiving layer 4 of the uppermost layer in the process of manufacturing the sheet molded article 11. The release layer 31 is formed without containing an organic solvent or the like for dissolving the thermal expansion layer 2, and does not require the expansion start temperature T of the thermal expansion layer 2_EsThe above heated material. The release layer 31 may be formed by fixing the ink receiving layer 4 to the surface before the completion of the light irradiation of the resin sheet 10 covering the thermal expansion layer in the production process of the sheet molded article 11, and may have, for example, a low elasticity, and may be formed by the upper surface of the thermal expansion layer 2 (and the release layer) after the completion of the light irradiation31) elongation and deformation, fracture and separation occur. The release layer 31 may be a heat-peelable adhesive whose adhesive strength is reduced by heating to a predetermined temperature or higher. The predetermined temperature is lower than the expansion start temperature T of the thermal expansion layer 2_EsThe heating temperature is a heating temperature in a region where the photothermal conversion member 5 is not attached due to light irradiation to the thermal expansion layer-coated resin sheet 10. The release layer 31 is preferably formed to have a thickness of about 1 μm to several μm, using a known easy-release adhesive such as a vinyl chloride-vinyl acetate copolymer. The release layer 31 may have a structure in which a resin film is laminated on these adhesives. That is, an adhesive is applied to the surface of the thermal expansion layer 2 to bond the resin film. By adopting such a configuration, the ink-receiving layer 4 can be effectively removed in the manufacturing process of the sheet formed article 11. The resin film is preferably about 10 to several tens of μm thick, and a known film commercially available for food packaging and the like can be used.

(ink-receiving layer)

Since the thermal expansion layer 2 is generally hydrophobic and is less likely to adhere ink before expansion, the ink receiving layer 4 is provided on the outermost surface of the thermal expansion layer-covering resin sheet 10 in order to adhere black ink constituting the photothermal conversion member 5. The ink receiving layer 4 is formed of porous silica or alumina (void type) having voids for absorbing ink, or a highly water-absorbent polymer (swelling type) that swells and absorbs ink, and is formed to have a thickness of about 10 to several tens of μm depending on the material or the like.

[ method for producing sheet molded article ]

(manufacturing apparatus)

An apparatus used for manufacturing a sheet molded product of the present invention will be briefly described. In the production of the thermal expansion layer-covered resin sheet 10, which is a material of the sheet molded article 11, there are used coating apparatuses for forming the thermal expansion layer 2, the release layer 31, and the ink receiving layer 4 before expansion on the base material 1, and a known cutter (not shown) for cutting paper or the like as necessary to process the thermal expansion layer-covered resin sheet 10 into a predetermined size. In the production of the sheet molded article 11, a printer (not shown) for printing the photothermal conversion member 5 with black ink on the surface of the thermal expansion layer-covered resin sheet 10, a processing tool (not shown) for cutting the thermal expansion layer-covered resin sheet 10 into the developed shape of the sheet molded article 11, and a light irradiation device 7 (see fig. 5) for irradiating the thermal expansion layer-covered resin sheet 10 with near infrared rays to heat the photothermal conversion member 5 and expand the thermal expansion layer 2 are used.

The coating device is a device for applying the coating material to a sheet-like member to form a coating film having a uniform thickness, and a known device such as a bar coating, roll coating, spray coating, etc. can be used.

The printer is a printer that prints the photothermal conversion element 5 with black ink, and can select a device corresponding to the printing quality or the like from known devices such as offset printing and inkjet printing, and an inkjet type suitable for mass production is particularly preferable. The printer adopts a specification that can be matched with the size and thickness of the thermal expansion layer covering resin sheet 10 as the object to be printed, and adopts a method in which the object to be printed is not heated to the expansion start temperature T of the thermal expansion layer 2_EsIn the above manner.

The processing tool is a tool for cutting the thermal expansion layer-coated resin sheet 10 into the developed shape of the sheet molded article 11 (see fig. 1B). Specifically, a cutter such as scissors or a cutter, a punching machine, or an electric saw is used in accordance with the rigidity, thickness, or the like of the thermal expansion layer-coated resin sheet 10, and the non-processed member is not heated to the expansion start temperature T of the thermal expansion layer 2_EsThe known tool described above.

The light irradiation device 7 irradiates light to the surface (printing surface) of the thermal expansion layer-coated resin sheet 10 on which the photothermal conversion member 5 is formed, and heats the thermal expansion layer 2. The following description will be made briefly with reference to fig. 5 and 6. Fig. 5 and 6 are cross-sectional views illustrating an outline of a light irradiation device used for manufacturing a sheet molded product.

As shown in fig. 5, the light irradiation device 7 includes a light irradiation unit 71, a cooler 72, a protection plate 73, and a conveyance mechanism 8. The light irradiation unit 71 is a main component of the light irradiation device 7 that irradiates light to the object to be processed (the cut thermal expansion layer-covered resin sheet 10), and includes a light source 7a and a reflection plate 7 b. In the light irradiation device 7, the light irradiation section 71 is provided above the conveyance mechanism 8 that conveys the object to be processed in order to irradiate the upper surface of the object to be processed with light, and irradiates the light over the entire length (full width) of the object to be processed in the conveyance width direction (the direction perpendicular to the paper surface in fig. 5) that the light irradiation device 7 can cope with. The light source 7a emits light including near infrared rays converted into heat by the photothermal conversion element 5, and a halogen lamp is used, for example. The reflecting plate 7b is formed into a curved surface having a substantially semi-cylindrical shape and has a mirror surface on the inner side thereof, and covers the upper side opposite to the side of the light source 7a facing the object, that is, the upper side, in order to efficiently irradiate the object with light from the light source 7 a. The light irradiation section 71 can be a member of a known apparatus for forming a three-dimensional object having irregularities on the surface from a thermally expandable sheet obtained by laminating a thermally expandable layer 2 on a thick paper or the like. The cooler 72 is an air-cooling fan, a water-cooling radiator, or the like, and is provided in the vicinity of the reflection plate 7 b. The shield plate 73 is a flat plate member horizontally disposed right below the light irradiation section 71, and is provided as needed to prevent the object from contacting the reflection plate 7b and the light source 7a when the object is lifted from the conveyance path, and to prevent the object from approaching the light source 7a and generating excessive heat. The shielding plate 73 is made of, for example, a glass plate having high transmittance of light (near infrared rays) so as to avoid shielding light from the light irradiation section 71.

The conveyance mechanism 8 conveys the object to be processed in one horizontal direction at a constant speed, and moves the entire object to be processed (the length in the conveyance direction) at least by a distance that completely passes through an area (light irradiation area) irradiated with light from the light irradiation section 71, that is, immediately below the light irradiation section 71. The conveying mechanism 8 is, for example, a belt conveyor, and is configured by a belt 81, a driving pulley (driving pulley) 82, a tail pulley 83, a motor (not shown) for driving the driving pulley 82 to rotate, and the like. The belt 81 on which the object to be treated is placed is made of rubber or the like having low thermal conductivity so as to prevent heat from propagating in the planar direction in the thermal expansion layer-coated resin sheet 10 as the object to be treated.

The light irradiation device 7 can also irradiate the lower surface of the object to be processed (the thermally-expansible layer-coated resin sheet 10) with light by vertically inverting the light irradiation section 71. In this case, since the light irradiation section 71 is disposed below the belt 81 on the lower or upper side of the conveying mechanism 8, the belt 81 is made of a light-transmitting member to avoid shielding the light from the light irradiation section 71. Such a belt for transmitting light is formed of, for example, glass cloth impregnated with a highly heat-resistant resin, and can be a belt of a belt conveyor used for appearance inspection of products and the like.

The conveying mechanism 8 is not limited to a belt conveyor, and may include, for example, a roller conveyor and a running table on which the object to be treated is placed (see embodiment 3 described later). Alternatively, the transport mechanism 8 may be a known linear motion mechanism such as a rack and pinion system or a ball screw system, and may be disposed so as to avoid the light irradiation region and connected to the edge of the table. Further, the transport mechanism 8 may employ a linear motion mechanism that moves the light irradiation section 71 in one direction instead of the object to be processed. The light irradiation device 7 may be configured not to include the transport mechanism 8 and to irradiate the entire upper surface or lower surface of the object with light simultaneously by using a configuration in which a plurality of light sources 7a are arranged in an array in the light irradiation section 71 to irradiate light in a planar manner.

Alternatively, as shown in fig. 6, the light irradiation device 7A includes a light irradiation section 71, a cooler 72, a table 74, a carry-in guide plate 75, a pressure roller 76, a conveying mechanism 8A, and a conveying mechanism 8B. The light irradiation unit 71 and the cooler 72 have the same structure as the light irradiation device 7 except that the light irradiation unit 71 is disposed to be inverted vertically so as to irradiate light upward. The table 74 is a flat plate-like member on which the object to be processed is placed, and is disposed horizontally over the entire area immediately above and behind the light irradiation section 71. The stage 74 is provided up to the front end of the light irradiation region in order to avoid interference with deformation of the object to be processed by light irradiation. The table 74 is made of a material having high light transmittance and low thermal conductivity as in the case of the belt 81 of the light irradiation device 7, and is made of, for example, a glass plate so that light from the lower light irradiation section 71 is irradiated to the lower surface of the object to be treated. The carry-in guide plate 75 is a horizontal flat plate-like member that supports the supplied object to be processed, and is provided on the rear side of the table 74 so as to be guided to the table 74 by the conveying mechanism 8A. The pressure roller 76 is disposed above the object to be processed and near the front end of the light irradiation region, and is provided as needed to press the object from above so as to prevent the object to be processed from floating from the table 74 and separating from the light irradiation section 71. The platen roller 76 is rotatably supported by a shaft in the conveyance width direction so that conveyance thereof is not hindered even if the object to be processed comes into contact therewith.

The conveying mechanism 8A conveys the object to be processed in one horizontal direction at a constant speed so as to pass through the light irradiation region. The conveying mechanism 8A is a sheet loader (sheet loader) applied to a conveying mechanism such as a printing press, and is configured by a main conveying roller 84, conveying rollers 85 and 85, a motor (not shown) for driving them to rotate, and the like. The main transport roller 84 is disposed above the table 74, and transports the object to be processed while pressing the table 74 from above and sliding the object. Preferably, the main transport roller 84 is disposed at the center of the light irradiation region in the transport direction or at the rear thereof so as not to interfere with the deformation of the object to be processed due to the light irradiation. The conveyance rollers 85, 85 nip the object to be processed from both surfaces in a group of up and down, and convey the object to the table 74 from the conveyance guide plate 75. The main conveyor roller 84 and the conveyor rollers 85 and 85 are provided over the entire conveyance width direction (the entire width) so as to convey in one direction regardless of the planar shape of the object to be processed, that is, the spread shape of the sheet formed product 11.

The conveyance mechanism 8B is provided as necessary to smoothly carry the object to be processed (irradiated with light) out of the light irradiation region, and is disposed below the stage 74 in the vicinity of the front side of the stage 74. The conveying mechanism 8B is, for example, a belt conveyor similar to the conveying mechanism 8 of the light irradiation device 7 (see fig. 5).

(method of producing sheet molded article)

A method for manufacturing a sheet molded article according to embodiment 1 will be described with reference to fig. 7 and 8A to 8D, and with appropriate reference to fig. 1 to 3. Fig. 7 is a flowchart showing a flow of the method for manufacturing a three-dimensional shaped object according to embodiment 1 of the present invention. Fig. 8A to 8D are schematic views for explaining the method for producing a three-dimensional shaped object according to embodiment 1 of the present invention, in which fig. 8A shows a cross-sectional view in a thermal expansion layer forming step, fig. 8B shows a cross-sectional view in an ink receiving layer forming step, fig. 8C shows a cross-sectional view in a printing step, and fig. 8D shows a cross-sectional view in a light irradiation step. As shown in fig. 7, the method of manufacturing a sheet molded article according to the present embodiment sequentially includes a thermal expansion layer-covering resin sheet manufacturing step S10, a printing step S21, a cutting step S23, a light irradiation step S24, and an ink removal step S25, which are steps of manufacturing the thermal expansion layer-covering resin sheet 10. The thermally-expansible layer-covering resin sheet manufacturing step S10 includes a thermally-expansible layer forming step S11, a release layer forming step S12, and an ink-receiving layer forming step S13 in this order, and further includes a cutting step S14 as needed.

In the thermal expansion layer forming step S11, as shown in fig. 8A, the thermal expansion layer 2 is formed on one surface (front side) of the substrate 1. The base material 1 is, for example, a long roll having a size corresponding to the size of the coating apparatus before cutting. Mixing the heat-expandable microcapsules, the white pigment and the thermoplastic resin solution to prepare a paste (slurry), applying the paste to the substrate 1 with a coating apparatus, drying the paste, and further re-applying the paste as needed to form a constant thickness t₀The thermal expansion layer 2. In fig. 8A to 8D and the cross-sectional views for explaining the other three-dimensional shaped object production method described later, the thermal expansion layer 2 is represented by a dot pattern simulating a microcapsule, and the degree of expansion is represented by the size of the dot (circle) diameter.

In the release layer forming step S12, the release layer 31 is formed on the thermally expandable layer 2 (see fig. 8B). Then, in the ink receiving layer forming step S13, the ink receiving layer 4 is formed on the release layer 31 as shown in fig. 8B. In these steps S12 and S13, the material of each of the release layer 31 and the ink-receiving layer 4 is coated with a coating device and dried to have a predetermined thickness.

In the cutting step S14, the base material 1, and the thermally-expansible layer 2, the release layer 31, and the ink-receiving layer 4 thereon are cut to obtain a thermally-expansible layer-coated resin sheet 10 (see fig. 4) having a size corresponding to the printer used in the subsequent printing step S21.

In the printing step S21, as shown in fig. 8C and 1B or 2B, the photothermal conversion member 5 is formed by printing a line with black ink on the ink receiving layer 4 in which the surface of the resin sheet 10 is covered with the thermal expansion layer. Fig. 8C and 8D and cross-sectional views described later show cross sections perpendicular to a line (photothermal conversion member 5). Here, the photothermal conversion member will be described.

The photothermal conversion member 5 is a black pattern formed in a linear shape on the surface of the thermal expansion layer-coated resin sheet 10, and the sheet molded product 11 is formed by bending the substrate 1 inward at this line. In the present embodiment, the photothermal conversion member 5 corresponds to a convex fold line since it is formed on the surface of the substrate 1 on the thermal expansion layer 2 side. The photothermal conversion member 5 absorbs light in a specific wavelength band, for example, near infrared rays (wavelength of 780nm to 2.5 μm), converts the light into heat, and emits the heat, and specifically, is composed of black (K) ink for ordinary printing containing carbon black. The photothermal conversion member 5 emits heat when irradiated with light, heats the thermal expansion layer 2 and the substrate 1, expands the thermal expansion layer 2, and enables plastic deformation of the substrate 1. In the printing step S21, the photothermal conversion element 5 may be printed not only with the raised line but also with a contour line (a thick line in fig. 1B and 2B) that becomes a cut line used in the subsequent cutting step S23. In the present specification, the term "light" refers to near infrared rays (near infrared rays) that are converted into heat by the carbon black of the photothermal conversion member 5, unless otherwise stated. In addition, as long as the heat can be converted into heat, electromagnetic waves including radio waves and the like can be applied without being limited to light.

The photothermal conversion member 5 is adjusted to have a concentration (black concentration) at which the thermal expansion layer 2 and the substrate 1 are heated to an appropriate temperature in the subsequent light irradiation step S24, because the higher the concentration of carbon black, that is, the darker the color (black). In the photothermal conversion member 5, the wider the line width (lateral length in the drawing), the wider the region in which the thermal expansion layer 2 expands and the larger the amount of expansion (increase in volume), and the load applied to the substrate 1 by the thermal expansion layer 2 can be increased to bend at a larger angle. The photothermal conversion element 5 is black if the line width is thick enoughThe substrate 1 can be bent even if the concentration is somewhat low. However, if the line width of the photothermal conversion member 5 is too large, the ridge line of the sheet molded product 11 has a low curvature and is rounded, and the ridge line is a double line. Conversely, when the line width of the photothermal conversion member 5 is too small, the amount of expansion of the thermal expansion layer 2 is insufficient, the heated region of the substrate 1 is narrow, and the substrate 1 cannot be bent, and even if the black concentration is high, the absolute amount of carbon black is insufficient and the thermal expansion layer 2 does not expand. The thicker the substrate 1, the higher the black density of the photothermal conversion member 5 is designed, and the thicker the line width is designed, so that the load applied becomes high and the heat is propagated from the photothermal conversion member 5 as a whole in the thickness direction. In the subsequent light irradiation step S24, when the light output is high and the irradiation time is long, the amount of expansion of the thermal expansion layer 2 increases. Therefore, the photothermal conversion member 5 preferably has a line width set according to the black density in accordance with the thickness of the substrate 1, the irradiation condition of light, and the like. Further, the line width and the black density may be changed according to a desired bend angle. In the case of printing the contour lines described above, the thermal expansion layer 2 is printed so as not to be heated to the expansion start temperature T within a range where the thermal expansion layer can be visually recognized_EsThe above black density (gray) and line width are cut and removed inside the contour line in the cutting step S23.

In the cutting step S23, the thermally-expansible layer-coated resin sheet 10 on which the photothermal conversion member 5 is formed is cut into the developed shape of the sheet molded product 11 by a contour line indicated by a thick line in fig. 1B (or fig. 2B).

In the light irradiation step S24, the cut thermal expansion layer-coated resin sheet 10 is irradiated with light by the light irradiation device 7(7A) on the surface (front surface) on which the photothermal conversion member 5 is printed. The thermal expansion layer-covering resin sheet 10 is conveyed by the conveyance mechanism 8(8A) so that the portion printed with the photothermal conversion element 5 enters the light irradiation region, light is incident on the photothermal conversion element 5, and is converted into heat when absorbed so that the photothermal conversion element 5 generates heat, the thermal expansion layer 2 is heated, and further heat is transmitted in the thickness direction from the surface of the thermal expansion layer 2 so that the substrate 1 is heated. In the thermally-expansible layer 2, the expansion-starting temperature T is reached_EsThe above-described partial foaming is to expand from directly below the linear photothermal conversion member 5 in four directions around the line, mainly to the surface without any obstacle as shown by the white arrows in fig. 8D, and further to expand so as to push outward in the line width direction in the thermal expansion layer 2. At this time, if the substrate 1 reaches the thermal deformation temperature T_DAs described above, as indicated by the white arrows in the figure, the force pushing the thermal expansion layer 2 outward acts on the substrate 1, and the thermal expansion layer-covering resin sheet 10 bends toward the substrate 1 and bends on both sides of the line (the photothermal conversion member 5) due to plastic deformation of the substrate 1. When the portion of the resin sheet 10 on which the photothermal conversion member 5 is printed is retreated from the light irradiation region and the irradiation of light to the portion is stopped for a certain period of time (short time), the substrate 1 heated by the photothermal conversion member 5 is cooled to less than the thermal deformation temperature T_DThereby, the thermal expansion layer of the portion on which the photothermal conversion member 5 is printed covers the deformation of the resin sheet 10. The thermal expansion layer covers the resin sheet 10 when the base material 1 has a thermal deformation temperature T_DAs described above and the expansion of the thermal expansion layer 2 progresses, the bending angle gradually increases. Therefore, if the thermal expansion layer 2 does not expand enough, the longer the light irradiation time, the larger the bending angle of the ridge line. The irradiation time of the light can be adjusted by the conveyance speed of the light irradiation device 7.

In the present embodiment, when the light irradiation device 7 that irradiates light from above is used, the thermally-expansible layer-coated resin sheet 10 is processed so that the surface faces upward, and the ridge line is raised as shown in fig. 5. On the other hand, in the case of using the light irradiation device 7A that irradiates light from below, the thermally-expansible layer-coated resin sheet 10 is processed with its surface facing downward, and as shown in fig. 6, the ridge line becomes concave and the end portion floats.

Preferably, the expansion start temperature T is reached at the thermal expansion layer 2_EsAt the point in time when the substrate 1 reaches the heat distortion temperature T_DThe above. With respect to the thermally expandable layer 2, if the substrate 1 is less than the thermal deformation temperature T at the time of expansion_DSince the material expands toward the surface side, the amount of expansion in the line width direction is reduced, and even after the substrate 1 reaches the heat distortion temperature T_DThe load acting on the base material 1 is also reduced, and the bending angle is reduced. In the present embodiment, the temperature of the thermal expansion layer 2 rises earlier than the substrate 1 by the heat-generating photothermal conversion member 5, and therefore, as described above, the expansion start temperature T of the thermal expansion layer 2 is preferably set to be higher than the expansion start temperature T of the substrate 1_EsSpecific heat distortion temperature T of base material 1_DHigh. In addition, the heating temperature (maximum temperature) of the thermal expansion layer 2 is preferably the maximum expansion temperature T_Emax(T_EsAbout +30 to 50 ℃), specifically (T)_Emax+5 ℃ or lower. Therefore, with the photothermal conversion element 5, the black density is designed to generate heat to T_EsAbove and T_DAbove, it is preferable to design the heat generation to T_EmaxThe near black density.

In addition, if the thermally-expansible layer-covering resin sheet 10 is bent in the light-irradiated region, the distance between the photothermal conversion member 5 and the light source 7a on the surface of the thermally-expansible layer-covering resin sheet 10 may vary, and thus the thermally-expansible layer-covering resin sheet may not be heated to the designed temperature. On the other hand, a certain amount of time is required from when the photothermal conversion member 5 generates heat by being irradiated with light to when the heat propagates through the thermal expansion layer 2 and the substrate 1 to start expansion and bending. Therefore, in the light irradiation step S24, it is preferable that the thermally-expansible layer-covering resin sheet 10 starts to bend after passing through the light irradiation region of the light irradiation device 7 (7A). The light irradiation is performed for a sufficient time to heat the photothermal conversion member 5 to a desired temperature, and the output, conveyance speed, and the like of the light source 7a of the light irradiation device 7 are set so that the thermally-expansible layer-covering resin sheet 10 is bent at the above-described timing. The conveyance direction of the thermal expansion layer-covered resin sheet 10 is not particularly limited as long as the cut thermal expansion layer-covered resin sheet 10 (the developed shape of the sheet molded article 11) is within the conveyance width of the light irradiation device 7(7A), but the conveyance direction length of the photothermal conversion element 5 for forming the ridge line of 1 side of the sheet molded article 11 is preferably small. Therefore, the sheet molded article 11 is preferably conveyed in the left-right direction or the up-down direction in fig. 1B.

Further, when the light irradiation device 7 is used, it is preferable that the entire thermally-expansible layer-covering resin sheet 10 (the developed shape of the sheet molded article 11) passes through the light irradiation region and then starts to bend. When the area irradiated with light first is bent in a state where the area not irradiated with light by the light irradiation device 7 remains, the thermal expansion layer-coated resin sheet 10 may float from the belt 81 as the predetermined conveyance path in the light irradiation area and not be heated to the designed temperature depending on the shape of the sheet molded article 11. On the other hand, in the case of using the light irradiation device 7A, the thermally expandable layer-coated resin sheet 10 is conveyed in a state of being held in contact with the table 74 while being sandwiched in the conveyance width direction at 2 positions of the conveyance rollers 85 and 85, the main conveyance roller 84, and the table 74, respectively, so that the distance between the light source 7A of the light irradiation section 71 and the object to be processed is kept constant. Therefore, even if the entire thermally-expansible layer-covering resin sheet 10 starts to bend light before passing through the light-irradiated region, the size of the developed shape of the sheet molded article 11 can be large.

In the ink removing step S25, the surface of the resin sheet 10 is covered with the curved thermally-expansible layer, and the ink-receiving layer 4 is peeled off from the release layer 31. This removes the light-heat conversion member 5, which is a black line on the ridge line, to obtain a sheet molded article 11 shown in fig. 3.

The sheet molded article 11 is further assembled into a box as shown in fig. 1A to complete the case. At this time, the fold line formed in the light irradiation step S24 is further bent deeper so as to increase the bending angle or is unfolded so as to decrease the bending angle by some external force such as manual work, as necessary. Since the fold line itself is formed in the light irradiation step S24 and is creased, the position of the fold line (ridge line) is not displaced, and thus, cracks are not generated in the substrate 1. Further, since the sheet molded article 12 is formed by raising the side surfaces from the top surface and the bottom surface by the arc-shaped folding line and in a state in which each surface is bent, the linear folding line such as between the top surface and the bottom surface is bent deeply as necessary, and the claw is inserted into the notch 1c as described above (see fig. 2A and 2B). Alternatively, the sheet molded article 12 may have the overlapping region 1m (see fig. 2B) as the bonding region, and the surface (thermal expansion layer 2) thereof and the bonding regionThe back surface (base material 1) of the bottom surface end is bonded with an adhesive or thermocompression bonded. The expansion starting temperature T of the base material 1 to which the heat-press-bonding is applied is lower than that of the thermal expansion layer 2_EsAnd is made of a resin material that can be thermocompression bonded. In these cases, the claws and the notches 1c are not formed.

(modification example)

In the cutting step S23, the thermal expansion layer-coated resin sheet 10 may be in a shape in which the curvature in the light irradiation step S24 is not hindered, without cutting the entire contour line. In this case, after the light irradiation step S24, the curved thermal expansion layer-covering resin sheet 10 is cut at the remaining contour line with scissors or the like to cut off unnecessary portions.

In the case where the light irradiation device 7A is used in the light irradiation step S24, the thermally-expansible layer-coated resin sheet 10 is not sandwiched after the trailing end passes through the main conveyance roller 84, and light irradiation to the vicinity of the trailing end is not controlled. Therefore, for example, in the sheet molded article 12 having a ridge line in the vicinity of the end of the developed shape (see fig. 2B), it is preferable that the grip portion 10t is connected to one end as shown in fig. 9 in the cutting step S23. Here, the grip portion 10t is connected to the overlapping region 1m that is folded inward by the assembly of the sheet molded article 12. The thermally expandable layer covers the resin sheet 10 and is supplied to the light irradiation device 7A so that the grip portion 10t is the trailing end. In fig. 9, the conveyance direction of the thermal expansion layer-coated resin sheet 10 is indicated by a blank arrow. The shortest length of the grip portion 10t in the conveyance direction from the end thereof to the photothermal conversion member 5 is equal to or longer than the distance from the contact position with the main conveyance roller 84 to the front end of the light irradiation region in the light irradiation device 7A. The length of the gripping portion 10t in the conveying width direction is set to a length at which the thermally-expansible layer-coated resin sheet 10 is sufficiently strongly gripped by the main conveying roller 84 and the table 74 and conveyed without being inclined in the conveying width direction. By leaving the grip portion 10t in the light irradiation step S24, the thermally-expansible layer-coated resin sheet 10 can be uniformly irradiated with light on all the photothermal conversion members 5 by the light irradiation device 7A.

The photothermal conversion element 5 can also be formed without using a printer. In the printing step S21, a raised line is formed on the surface of the thermal expansion layer-coated resin sheet 10 by hand drawing with a writing instrument such as a felt pen, ink, pen, or pencil using black ink. As for the writing instrument, a writing instrument which is easily drawn with a constant black density and a constant line width and whose pressure is not high because the thermal expansion layer 2 is soft, specifically, a felt pen is preferable.

The sheet molded article 11 may be kept in a state where the photothermal conversion member 5 is attached along the ridge line on the surface without performing the ink removal step S25 depending on the purpose or the like. In this case, the thermally expandable layer-covering resin sheet 10 may not include the release layer 31, and therefore the release layer forming step S12 is not performed.

The curved thermally-expansible layer-coated resin sheet 10 may be a sheet-formed article 11A composed only of the curved substrate 1 as shown in fig. 10, in which the thermally-expansible layer 2 is peeled off together with the underlying thermally-expansible layer 4 when the ink-receiving layer 4 is removed in the ink removing step S25. Since the sheet molded article 11A has no thermal expansion layer 2, the ridges do not float and are conspicuous, and the sheet molded article has a texture of the base material 1 and further has a transparent feel depending on the material of the base material 1. The sheet molded article 11A is manufactured by covering the resin sheet 10B with the thermal expansion layer shown in fig. 11. Fig. 11 is a cross-sectional view schematically showing a structure in which a thermally expandable layer covering a resin sheet is used as a material of a three-dimensional structure according to a modification example of embodiment 1 of the present invention.

In order to enable the thermal expansion layer 2 to be peeled from the substrate 1, the thermal expansion layer-covering resin sheet 10B is provided with a release layer 31A laminated between the substrate 1 and the thermal expansion layer 2, instead of the release layer 31 of the thermal expansion layer-covering resin sheet 10, as shown in fig. 11. The respective structures of the substrate 1, the thermal expansion layer 2, and the ink receiving layer 4 are as described in the above embodiments.

(peeling layer)

The release layer 31A is provided to remove the thermal expansion layer 2 expanded in the ridge line from the bent base material 1 (sheet molded article 11A) in the process of manufacturing the sheet molded article 11A. The release layer 31A has at least temporary heat resistance against a heating temperature at which the thermal expansion layer 2 is expanded in the production process of the sheet molded article 11A, has an adhesive strength that does not peel off when the thermal expansion layer 2 is expanded and the substrate 1 is bent, and forms a flexible coating film in order to avoid hindrance to bending of the substrate 1 and the like. For example, a thermosetting adhesive or an ultraviolet-curable adhesive which can be cured at a temperature at which the substrate 1 does not melt can be used for the release layer 31A, and a thickness of about 1 μm to several μm is preferable. The release layer 31A may have a structure in which a flexible resin film is laminated on these adhesives. The resin film is preferably a film having a thickness of about 1 to 20 μm so as not to hinder the propagation of heat from the thermally-expansible layer 2 to the substrate 1, and a commercially available film for food packaging or the like can be used. Examples of the resin film include an ethylene-vinyl alcohol copolymer (EVOH) resin film. Further, the release layer 31A may be formed of a resin film alone or may be formed by thermocompression bonding (lamination) to the substrate 1. The thermal compression bonding may be based on the heat-sealing (heat-welding) property of either the base material 1 or the resin film constituting the release layer 31A.

(method of producing sheet molded article)

As shown in fig. 7, the method of manufacturing a sheet molded article according to this modification includes a thermal expansion layer-covered resin sheet manufacturing step S10, a printing step S21, a cutting step S23, a light irradiation step S24, and an ink removal step S25 (thermal expansion layer removal step) in this order. In the thermally expandable layer-covering resin sheet manufacturing step S10, the release layer forming step S12 and the ink receiving layer forming step S13 in the same step S10 in the above embodiment are performed in the order mentioned. That is, the thermally expandable layer 2 is formed on the surface of the release layer 31A on the substrate 1. In the ink removing step S25, the thermally-expansible layer 2 is peeled from the bent thermally-expansible layer-covering resin sheet 10B to form the sheet molded article 11A. When the sheet-shaped product 12 (see fig. 2A and 2B) has a bonding region (overlapping region 1m), the substrates 1 can be bonded to each other by heat pressing.

Alternatively, the release layer 31A may be formed on a resin filmAfter the thermally expandable layer 2 is formed, the release layer 31A and the substrate 1 are set to a temperature lower than the expansion starting temperature T of the thermally expandable layer 2_EsAnd then thermocompression bonded. In addition, in the present modification, since the heat-expandable layer 2 and the substrate 1 can be separated from each other without providing the release layer 31A, the expansion start temperature T of the heat-expandable layer 2 can be set to be lower than that of the substrate 1_EsAnd a resin to be thermocompression bonded. Specifically, the heat-expandable layer 2 is formed on a release paper or the like, and the surface thereof is thermally pressed against the substrate 1, and the release paper is peeled off to form the ink-receiving layer 4. Alternatively, the ink receiving layer 4 may be formed on a release paper or the like, and the thermal expansion layer 2 may be formed thereon.

The sheet molded article 11 can also be produced by printing black lines on the surface (back surface) of the thermal expansion layer-coated resin sheet on the substrate 1 side and irradiating the surface with light. When the sheet molded article 11 is assembled into a case, the line is printed on the inner surface, so that the sheet molded article is difficult to visually recognize, and the ink removing step S25 may not be performed. Such a sheet molded article 11 is manufactured by covering the resin sheet 10C with the thermal expansion layer shown in fig. 12. Fig. 12 is a cross-sectional view schematically showing a structure in which a thermally expandable layer covering a resin sheet is used as a material of a three-dimensional structure according to a modification example of embodiment 1 of the present invention.

As shown in fig. 12, the thermal expansion layer-covering resin sheet 10C is formed by covering the ink receiving layer 4 on the back surface of the base 1, that is, by laminating the ink receiving layer 4, the base 1, the thermal expansion layer 2, and the ink receiving layer 4 in this order so that printing can be performed on the back surface. The respective elements of the thermal expansion layer-coated resin sheet 10C are as described in the above embodiment. However, in this modification, a pigment other than black (not containing carbon black) is used for the substrate 1 when it is colored. In addition, the heat distortion temperature T of the base material 1_DIt may be higher than the expansion start temperature T as long as it is within the expansion temperature range of the thermal expansion layer 2_Es。

(method of producing sheet molded article)

A method for manufacturing a sheet molded article according to this modification will be described with reference to fig. 13A and 13B, as appropriate, and fig. 7. Fig. 13A and 13B are schematic views for explaining a method for manufacturing a three-dimensional shaped object according to a modification example of embodiment 1 of the present invention, in which fig. 13A is a cross-sectional view in a printing step, and fig. 13B is a cross-sectional view in a light irradiation step. The method of manufacturing a sheet molded article according to this modification includes a thermal expansion layer-covered resin sheet manufacturing step S10, a printing step S21, a cutting step S23, and a light irradiation step S24 (see fig. 7) in this order, in which the thermal expansion layer-covered resin sheet 10C is manufactured. In the thermally expandable layer-covering resin sheet manufacturing step S10, the release layer forming step S12 in the same step S10 in the above embodiment is not performed, and the ink receiving layer forming step S13 is performed on both sides. Alternatively, the ink receiving layer 4 may be formed on the back surface of the substrate 1, and then the thermally expandable layer 2 may be formed on the surface of the substrate 1. Further, the steps different from the above embodiment will be described in detail.

In the printing step S21, as shown in fig. 13A, the photothermal conversion member 5A is formed by printing a line with black ink on the ink receiving layer 4 in which the thermal expansion layer covers the back surface of the resin sheet 10C. The photothermal conversion element 5A is formed in a linear black pattern on the back surface of the thermal expansion layer-covered resin sheet 10C, and the thermal expansion layer-covered resin sheet 10C is bent with the surface thereof being on the outer side in the subsequent light irradiation step S24 in the same manner as in the above embodiment, so that the photothermal conversion element 5A corresponds to a concave folding line. The other structure of the photothermal conversion member 5A is substantially the same as that of the photothermal conversion member 5 in the above embodiment, and a contour line serving as a cut line for the cutting step S23 may be printed. However, in the light irradiation step S24, since the thermal expansion layer 2 expands in a region somewhat extended in the line width direction directly above the photothermal conversion member 5A, it is preferable to design the line width of the photothermal conversion member 5A to be small in a range where the heated region of the substrate 1 is secured.

In the light irradiation step S24, the surface (back surface) of the thermal expansion layer-coated resin sheet 10C cut in the cutting step S23 on which the photothermal conversion member 5A is printed is irradiated with light by the light irradiation device 7 (7A). Then, the photothermal conversion member 5A generates heat, the substrate 1 is heated, and further the heat propagates in the thickness direction in the substrate 1, and the thermal expansion layer 2 is heated. Thereby, as shown in FIG. 13BAs in the above embodiment, the thermal expansion layer 2 expands directly above and in the vicinity of the photothermal conversion member 5A, the substrate 1 is plastically deformed, and the thermal expansion layer-covering resin sheet 10C bends and bends toward the substrate 1 side on both sides of the line (photothermal conversion member 5A). In this modification, since the photothermal conversion member 5A serving as a heat source is disposed close to the substrate 1, the substrate 1 is heated earlier than the thermal expansion layer 2. Therefore, the thermal expansion layer 2 reaches the expansion start temperature T_EsBefore, the substrate 1 was liable to reach the heat distortion temperature T_DIn particular, even if the substrate 1 is thick, the entire thickness direction thereof is heated to the heat distortion temperature T_DThe above is easily plastically deformed. On the other hand, the thermal expansion layer 2 has an expansion start temperature T as compared with the above embodiment_EsThe above time, i.e., the time during which the expansion progresses, is shorter than the light irradiation time, and this tendency becomes stronger as the thickness of the substrate 1 becomes thicker. Therefore, in order to sufficiently expand the thermal expansion layer 2, it is preferable to set the black density and line width of the photothermal conversion member 5A or the output of the light irradiation device 7 so that the photothermal conversion member 5A generates heat to a high temperature in a short time.

In the present modification, when the light irradiation device 7 is used, the thermal expansion layer-coated resin sheet 10C is disposed with the back surface (printing surface) facing upward, and the ridge line is folded concave and the end portion floats. On the other hand, when the light irradiation device 7A is used, the thermally expandable layer-coated resin sheet 10C is disposed with the back surface facing downward, and the ridge line is raised.

Since the ink receiving layer 4 is also provided on the surface (on the thermal expansion layer 2) of the thermal expansion layer-coated resin sheet 10C, the photothermal conversion element 5 can be printed on the surface in the same manner as in the above embodiment. By covering the resin sheet 10C with the thermal expansion layer to produce the sheet molded article 11, the black yarn can be attached to either the outer surface or the inner surface, in other words, the yarn can be prevented from being attached to the desired surface. Alternatively, the thermally-expansible layer-coated resin sheet 10C may be used exclusively for back printing, and may be formed by coating the ink-receiving layer 4 only on the back surface, further providing a release layer 31 (see fig. 4) between the ink-receiving layer 4 and the substrate 1, and performing the ink removing step S25 after the light irradiation step S24 to produce a sheet molded article 11 having no black lines on the inner surface. The release layer 31 in this modification can be formed by, for example, thermally bonding a resin film to the base material 1.

[ 2 nd embodiment ]

In the stereomorphic object according to embodiment 1, since the thermal expansion layer and the 2 layers of the base material are heated by the linear photothermal conversion member printed on one surface of the thermal expansion layer-coated resin sheet, in order to bend the thermal expansion layer-coated resin sheet, the 2 layers need to be heated so as to be limited to the region on the line (photothermal conversion member) and to reach the respective appropriate temperatures at appropriate times. Therefore, it is difficult to make each layer, especially the substrate, thick. Therefore, a configuration is adopted in which each layer can be easily and appropriately heated by applying a member that transmits light to the base material. Hereinafter, the three-dimensional shaped object according to embodiment 2 of the present invention will be described with reference to fig. 14 and 15A to 15D, and with appropriate reference to fig. 1A, 1B, 2A, 2B, and 10, together with a method for manufacturing the same. Fig. 14 is a flowchart showing a flow of the method for manufacturing a three-dimensional shaped object according to embodiment 2 of the present invention. Fig. 15A to 15D are schematic views for explaining the method for producing a three-dimensional shaped object according to embodiment 2 of the present invention, in which fig. 15A shows a cross-sectional view in a thermal expansion layer forming step, fig. 15B shows a cross-sectional view in a printing step, fig. 15C shows a cross-sectional view in a bonding step, and fig. 15D shows a cross-sectional view in a light irradiation step. The same elements as those in the above-described embodiment (see fig. 1 to 11) are denoted by the same reference numerals, and description thereof is omitted.

A sheet molded article (three-dimensional shaped article) 11A according to embodiment 2 of the present invention is a box shown in fig. 1A or 2A, like the sheet molded article 11 or the sheet molded article 12 according to embodiment 1, and is configured only by a bent base material 1A, like the modification of embodiment 1, as shown in fig. 10. Such a sheet molded article 11A is manufactured from the thermal expansion film 20 and the resin sheet 10A shown in fig. 15A and 15B.

The resin sheet 10A is a printed material for printing black ink constituting the photothermal conversion member 5, and as shown in fig. 15B, an ink receiving layer 4 is covered on the surface (upper surface) so that the base material 1A can be printed, and a release layer 31A is further provided between the ink receiving layer 4 and the base material 1A. As in the case of the thermally-expansible layer-coated resin sheet 10 according to embodiment 1, the resin sheet 10A may have a size equal to or larger than the developed shape (see fig. 1B and 2B) of the sheet molded article 11A, and may have a size corresponding to a printer used for forming the photothermal conversion member 5 when the sheet molded article 11A is produced. The thermal expansion film 20 is a film-like member capable of easily laminating the thermal expansion layer 2 on the substrate 1A (resin sheet 10A) in the production of the sheet molded article 11A, and is formed by laminating the thermal expansion layer 2 and the adhesive layer 32, and the adhesive layer 32 side is bonded to and supported by the release paper 33. The thermally-expansible film 20 may have the same shape as the resin sheet 10A or a smaller size than the resin sheet 11A, as long as it has a size equal to or larger than the developed shape of the sheet molded article 11A.

The substrate 1A has substantially the same structure as the substrate 1 of embodiment 1, but has a structure that sufficiently transmits light, and when colored, it is preferable to suppress the content of the pigment according to the thickness or the like, and it does not contain a black pigment. The release layer 31A is provided for removing the ink receiving layer 4 and the thermal expansion layer 2 attached thereto from the bent substrate 1A (sheet molded article 11A) in the process of manufacturing the sheet molded article 11A, and has the same configuration as the modification of embodiment 1 (see fig. 11). The respective structures of the thermal expansion layer 2 and the ink receiving layer 4 are as described in embodiment 1. The adhesive layer 32 is an adhesive for bonding the ink receiving layer 4 on the surface of the resin sheet 10A to the thermally expandable layer 2, and is selected from known adhesives. Therefore, the adhesive layer 32 is an adhesive which has good adhesion to the ink receiving layer 4 and the thermal expansion layer 2, is higher than at least the adhesion between the release layer 31A and the substrate 1A, can maintain the adhesion even at a heating temperature for plastically deforming and expanding the substrate 1A and the thermal expansion layer 2, and has flexibility so as not to hinder the bending of the substrate 1A and the like. The adhesive layer 32 is preferably formed to have a thickness of about 1 to 20 μm, and more preferably less than 10 μm, so as not to hinder the heat transfer from the photothermal conversion member 5 to the heat expansion layer 2. The release paper 33 is provided on the back surface of the thermal expansion film 20, covers the adhesive layer 32, and supports the soft thermal expansion layer 2. Since the release paper 33 is removed in the process of manufacturing the sheet molded article 11A, it is a film-like member that can be peeled from the adhesive layer 32, and a release paper of a general double-sided adhesive tape can be used. That is, both the adhesive layer 32 and the release paper 33 can be double-sided tapes.

(method of producing sheet molded article)

As shown in fig. 14, the method for producing a sheet molded article according to the present embodiment includes, after performing the thermal expansion layer forming step S11A of producing the thermal expansion film 20, the steps S12A, S13, and S14 of producing the resin sheet 10A, and the printing step S21, the bonding step S22 of bonding the resin sheet 10A to the thermal expansion film 20, the dicing step S23, the light irradiation step S24A, and the thermal expansion layer removing step S25A are performed in this order. After the thermal expansion layer forming step S11A and before the bonding step S22, a dicing step S15 is performed to dice the thermal expansion film 20 as necessary. In the production of the sheet formed article of the present embodiment, the apparatus used in the production of the sheet formed article of embodiment 1 can be used.

In the thermal expansion layer forming step S11A, as shown in fig. 15A, a paste is applied to the adhesive layer 32 applied to the release paper 33 to form the thermal expansion layer 2, and the thermal expansion film 20 is obtained. The same procedure as in the thermal expansion layer forming step S11 of embodiment 1 is used except for the difference in the substrate to be formed. Alternatively, the thermal expansion layer 2 may be formed on another release paper or the like, and the adhesive layer 32 may be applied thereon and bonded to the release paper 33. The obtained thermally-expansible film 20 is cut into a shape corresponding to the developed shape of the resin sheet 10A or the sheet molded article 11A in the cutting step S15.

In the release layer forming step S12A, the release layer 31A is formed on the substrate 1A (see fig. 15B). For example, a resin film constituting the release layer 31A is stacked on the base 1A and thermocompression bonded. Then, in the ink receiving layer forming step S13, the ink receiving layer 4 is formed on the release layer 31A (see fig. 15B). In the cutting step S14, the base material 1A on which the release layer 31A and the ink receiving layer 4 are formed is cut into a predetermined size to obtain a resin sheet 10A.

In the printing step S21, as shown in fig. 15B, the photothermal conversion member 5 is formed by printing a line with black ink on the ink receiving layer 4 on the surface of the resin sheet 10A. As described in embodiment 1, the photothermal conversion element 5 has a structure in which the resin sheet 10A is bent so that the printing surface is outward in the subsequent light irradiation step S24A, and therefore the photothermal conversion element 5 corresponds to a raised line. In addition, a contour line to be a cut line for the cutting step S23 may be printed.

In the bonding step S22, as shown in fig. 15C, the release paper 33 is peeled from the thermal expansion film 20, and is bonded and adhered to the surface (printing surface) of the resin sheet 10A by the adhesive layer 32. At this time, the thermal expansion film 20 is bonded so as to completely cover the region of the resin sheet 10A constituting the sheet molded article 11A. Then, the bonded resin sheet 10A and the thermal expansion film 20 (laminate) are cut into the developed shape of the sheet molded article 11A in the cutting step S23.

In the light irradiation step S24A, the cut laminate of the resin sheet 10A and the thermal expansion film 20 is irradiated with light from the light irradiation device 7(7A) toward the surface of the resin sheet 10A (the back surface of the substrate 1A). When light is transmitted through the substrate 1A and is incident on the photothermal conversion element 5, the photothermal conversion element 5 generates heat, and the thermal expansion layer 2 and the substrate 1A above and below it are heated, respectively, and as shown in fig. 15D, the laminated body is bent and curved to the substrate 1A side on both sides of the line (photothermal conversion element 5). In the present embodiment, since the photothermal conversion element 5 serving as a heat source is provided between the thermal expansion layer 2 and the substrate 1A, heat is transmitted in both the vertical direction to improve thermal efficiency, and the thermal expansion layer 2 is heated in parallel with the substrate 1A. Therefore, the thermal expansion layer 2 reaches the expansion start temperature T_EsBefore, the substrate 1A was apt to reach the heat distortion temperature T_DIn particular, even if the substrate 1A is thick, the entire substrate in the thickness direction is heated to the heat distortion temperature T_DThe above is easily plastically deformed. Further, since the propagation distance of heat in the thickness direction is short, the thermal expansion layer 2 and the heated region of the substrate 1A are less likely to spread in the line width direction from the photothermal conversion element 5, and particularly, the expansion of the thermal expansion layer 2 is easily controlled, whereby the roundness of the ridge line of the substrate 1A is suppressed.

In the present embodiment, when the light irradiation device 7 is used, the surface on the resin sheet 10A side (the back surface of the base material 1A) is treated so as to face upward, and the ridge line is folded concavely and the end portion floats. On the other hand, when the light irradiation device 7A is used, the resin sheet 10A side is treated with the surface facing downward, and the ridge line is raised.

In the thermally-expansible layer-removing step S25A, the thermally-expansible film 20 bonded to the surface is peeled from the curved resin sheet 10A. The ink receiving layer 4 and the release layer 31A of the resin sheet 10A were removed together by the adhesive layer 32 of the thermal expansion film 20, and a sheet molded article 11A composed only of the bent substrate 1A was obtained.

(modification example)

In the present embodiment, the thermal expansion film 20 may be bonded to the resin sheet 10A by applying an adhesive (adhesive layer 32) in the bonding step S22 without providing the adhesive layer 32 to the thermal expansion film 20.

In the present embodiment, the photothermal conversion member 5 may be printed on the thermal expansion film 20. Therefore, in the thermal expansion layer forming step S11A, the thermal expansion layer 2 is applied to and formed on release paper or the like, the ink receiving layer 4 is formed on the thermal expansion layer 2, and then the thermal expansion film 20 is cut into a size corresponding to a printer. A photothermal conversion element 5 is formed on the ink receiving layer 4 of the thermal expansion film 20. Next, the base material 1A is bonded to the printing surface of the thermal expansion film 20 (bonding step S22), and the release paper is peeled off to expose the thermal expansion layer 2 on the surface. At this time, the adhesive layer may be bonded with the release layer 31A such as an adhesive, or may be made to be lower than the expansion start temperature T of the thermally-expansible layer 2_EsThe bonding is performed by heat pressing the base material 1A at the temperature of (1). Thereafter, as in the above embodiment, the dicing step S23, the light irradiation step S24A, and the thermal expansion layer removing step S25A are performed in this order.

In the present embodiment, it is also possible to manufacture a sheet molded article 11 (see fig. 3) whose outer surface is covered with the thermal expansion layer 2. That is, since the thermally-expansible layer removing step S25A is not performed and the release layer 31A is not required, the release layer forming step S12A is not performed, and the ink-receiving layer 4 is formed directly on the substrate 1A (or on the thermally-expansible film 20). The sheet molded article 11 of this modification depends on the thickness of the thermal expansion layer 2, the black density and the line width of the photothermal conversion member 5, but the black line (photothermal conversion member 5) is covered with the expanded thermal expansion layer 2, and therefore the black line is not easily visually recognized on the ridge line in terms of appearance. Further, black lines are not easily visually recognized on the inner surface even by coloring of the base material 1A.

In the sheet molded article 11A of the present embodiment, the thermal expansion layer 2, i.e., the thermal expansion film 20, may be provided over the entire surface thereof during the production process, and at least the photothermal conversion member 5 may be covered, and preferably, the photothermal conversion member 5 is covered with the thickness of the substrate 1A (and the initial thickness t of the thermal expansion layer 2) or more on both outer sides in the line width direction thereof₀Above). The thermal expansion film 20 preferably has a width of a certain degree or more in order to secure adhesion to the resin sheet 10A. Therefore, the thermal expansion film 20 is cut into a band shape in the cutting step S15, and the band-shaped thermal expansion film 20 is attached to the resin sheet 10A along the printed black line (photothermal conversion member 5) in the attaching step S22. Alternatively, the photothermal conversion member 5 may be printed on the thermal expansion film 20, the thermal expansion film 20 may be cut into a strip shape so that the photothermal conversion member 5 becomes the center line, and the printed surface of the thermal expansion film 20 may be attached to the bent portion of the base material 1A.

[ 3 rd embodiment ]

The three-dimensional shaped objects according to embodiments 1 and 2 and their modifications are formed by bending the surface of the base material on the side covered with the thermal expansion layer as the outer side, and therefore have a three-dimensional shape formed only by convex folding (or only concave folding). Therefore, by covering both surfaces of the base material with the thermal expansion layer, a shape in which the convex folds and the concave folds are mixed is formed. Hereinafter, the three-dimensional shaped object according to embodiment 3 of the present invention will be described with reference to fig. 16A, 16B, and 17. Fig. 16A is an external view of the three-dimensional structure of the present invention, and fig. 16B is a development view of the three-dimensional structure. Fig. 17 is a partial sectional view schematically showing the structure of the three-dimensional shaped object according to embodiment 3 of the present invention. The same elements as those in the above-described embodiment (see fig. 1 to 13) are denoted by the same reference numerals, and description thereof is omitted.

(sheet Molding)

As shown in fig. 16A, the sheet molded article (three-dimensional article) 13 has a shape in which squares of 6 surfaces having diagonal lines oriented in the vertical direction are connected at vertexes and arranged in a ring shape in the horizontal direction, and the upper and lower ends of a cylindrical body having its upper and lower portions bent in a corrugated shape are narrowed, and can be used as an accessory such as a lamp cover, for example. Such a sheet molded article 13 is assembled by folding a rectangular flat sheet shown in fig. 16B with the solid line (photothermal conversion member 51) in the figure as a convex folding line and the broken line (photothermal conversion member 52) as a concave folding line, and joining the left and right sides to each other to form a tube shape with the overlapping region 1m as a bonded region.

As shown in fig. 17, the sheet molded article 13 according to embodiment 3 of the present invention is composed of a base material 1 and thermal expansion layers 21 and 22 laminated on both surfaces thereof, and the thermal expansion layer 21 or the thermal expansion layer 22 covering the outer surface thereof on the ridge line expands. The sheet molded article 13 of the present embodiment is manufactured from the thermal expansion layer-covered resin sheet 10D shown in fig. 18.

(thermal expansion layer covering resin sheet)

The structure in which the thermal expansion layer of the sheet molded article 13 covers the resin sheet 10D before molding will be described below with reference to fig. 18. Fig. 18 is a sectional view schematically showing the structure of a thermally expandable layer-covered resin sheet as a material of the three-dimensional structure according to embodiment 3 of the present invention. The thermal expansion layer-covering resin sheet 10D is a flat plate-like member having a uniform thickness, and is formed by laminating the 1 st thermal expansion layer 21 on one surface of the base 1, the 2 nd thermal expansion layer 22 on the other surface, and further laminating the release layer 31 and the ink-receiving layer 4 in this order on both surfaces. The thermal expansion layer-coated resin sheet 10D is a printed matter for printing black ink constituting the photothermal conversion members 51, 52 on both sides, i.e., the ink receiving layers 4, 4. Therefore, the thermal expansion layer-covered resin sheet 10D has a size (set size) corresponding to a printer used for forming the photothermal conversion members 51, 52 when the sheet molded product 13 is manufactured, as in the case of the thermal expansion layer-covered resin sheet 10 of embodiment 1, as long as the sheet molded product 13 has a developed shape (see fig. 16B) or more, and is, for example, a3 paper size.

The respective structures of the substrate 1, the release layer 31, and the ink-receiving layer 4 are as described in embodiment 1. The 1 st thermal expansion layer 21 and the 2 nd thermal expansion layer 22 (appropriately summarized as the thermal expansion layers 21 and 22) have the same configuration as the thermal expansion layer 2 of embodiment 1. The materials of the 1 st and 2 nd thermal expansion layers 21 and 22 and the initial thickness t₁、t₂Same (t)₁＝t₂). Further, the thermal deformation temperature T of the thermoplastic resin constituting the substrate 1_DPreferably the expansion start temperature T_EsHereinafter, it is more preferably less than the expansion start temperature T_Es. If the initial thickness t of the thermal expansion layers 21, 22 is₁、t₂When the thickness is large, as described in embodiment 1, the load acting on the base material 1 due to expansion increases in the process of producing the sheet molded article 13. However, on the other hand, the thermal expansion layer 22(21) which becomes the inner side when the thermal expansion layer-coated resin sheet 10D is bent is excessively (with a high curvature), and it is difficult to largely bend due to elasticity, which hinders plastic deformation of the base material 1. Specifically, the initial thickness t of the thermal expansion layers 21, 22₁、t₂Preferably 50 to 100 μm. Further, it is preferable to design the initial thickness t₁、t₂So that the load due to the expansion of the outer thermal expansion layers 21 and 22 and the thickness t of the inner non-expansion layer₂(t₁) The thermal expansion layers 22 and 21 of (2) are all suitable.

(manufacturing apparatus)

The apparatus used for manufacturing the sheet formed product of the present embodiment will be briefly described. In the production of the thermal expansion layer-covered resin sheet 10D, which is a material of the sheet molded article 13, a coating device and a cutter (not shown) are used in the same manner as in the production of the thermal expansion layer-covered resin sheet 10 according to embodiment 1. In the production of the sheet molded article 13, a printer that prints the photothermal conversion members 51 and 52 with black ink on both surfaces of the thermal expansion layer-covered resin sheet 10D, and a processing tool (not shown) that cuts the thermal expansion layer-covered resin sheet 10D into the developed shape of the sheet molded article 13 are used, as described in embodiment 1. In the present embodiment, a light irradiation device 7B (see fig. 19) is also used which irradiates both surfaces of the thermal expansion layer-coated resin sheet 10D with near infrared rays simultaneously. Hereinafter, the light irradiation device will be described in brief with reference to fig. 19. Fig. 19 is a sectional view schematically illustrating a light irradiation device used for manufacturing a three-dimensional object.

As shown in fig. 19, the light irradiation device 7B includes 2 light irradiation units 71 and coolers 72, and further includes a protection plate 73, a table 77, and a conveyance mechanism 8C. The light irradiation unit 71, the cooler 72, and the protection plate 73 have the same configuration as the light irradiation device 7 (see fig. 5) used in embodiments 1 and 2. The light irradiation device 7B includes a light irradiation unit 71 and a cooler 72 that are vertically inverted as in the light irradiation device 7A (see fig. 6), and a table 77, and further includes a conveyance mechanism 8C in place of the conveyance mechanism 8, in addition to the light irradiation device 7 that irradiates the upper surface of the object to be processed with light. The table 77 is a flat plate-like member on which the object to be processed is placed, and is conveyed by the conveying mechanism 8C together with the object to be processed. The table 77 is made of a material having high light transmittance and low thermal conductivity as in the case of the belt 81 of the light irradiation device 7 so that the light from the lower light irradiation section 71 is irradiated to the lower surface of the object to be treated, and is made of, for example, a glass plate. The light irradiation device 7B is preferably configured such that 2 light irradiation portions 71 and 71 are disposed to face each other so that the light irradiation areas coincide with each other, and the amount of light transmitted through the shield plate 73 or the table 77 and incident on the upper surface and the lower surface of the object to be processed is the same.

The conveying mechanism 8C conveys the table 77 together with the object to be processed thereon in one horizontal direction at a constant speed without shielding light from the light irradiation section 71 on the lower side. The conveying mechanism 8C is, for example, a roller conveyor, and includes a plurality of carrier rollers 86, 86, … arranged in a row in the conveying direction, a motor for driving the carrier rollers 86 to rotate at the same rotational speed (circumferential speed), a transmission mechanism (not shown) such as a belt or a chain, and the like. The carrier roller 86 is disposed so as to avoid the light irradiation region (directly above the lower light irradiation part 71). Alternatively, the conveying mechanism 8C may be configured by a belt conveyor in the same manner as the conveying mechanism 8 of the light irradiation device 7. However, in order not to shield the light from the light irradiation section 71, 2 belts were provided at both ends (both edges) in the conveyance width direction, and a table 77 was installed between the belts. Alternatively, as described in embodiment 1, the belt 81 (see fig. 5) of the conveying mechanism 8 may be a translucent member, and the object to be treated may be directly placed without using the table 77. Alternatively, the transport mechanism 8C may be a known linear motion mechanism such as a rack and pinion system or a ball screw system, and may be disposed so as to avoid the light irradiation region and connected to the table 77 at the edge or the like.

The light irradiation device 7B may further include a conveyance mechanism 8A configured by a sheet loader, as in the light irradiation device 7A (see fig. 6) according to embodiment 1. In the light irradiation device 7B, the main transport roller 84 is disposed in the vicinity of the rear side of the light irradiation region.

(method of producing sheet molded article)

A method for manufacturing a sheet molded article according to embodiment 3 will be described with reference to fig. 7, 20A, and 20B, and with reference to fig. 16 to 19 as appropriate. Fig. 20A and 20B are schematic views for explaining the method for producing a three-dimensional shaped object according to embodiment 3 of the present invention, in which fig. 20A shows a cross-sectional view in a printing step and fig. 20B shows a cross-sectional view in a light irradiation step. As shown in fig. 7, the method of manufacturing a sheet molded article according to the present embodiment sequentially includes a thermal expansion layer-covered resin sheet manufacturing step S10, a printing step S21, a cutting step S23, a light irradiation step S24, and an ink removal step S25, which are steps of manufacturing the thermal expansion layer-covered resin sheet 10D. In addition, in the thermally-expansible layer-covering resin sheet manufacturing step S10, as in embodiment 1, the thermally-expansible layer forming step S11, the peeling layer forming step S12, and the ink-receiving layer forming step S13 are performed in this order, but the step is performed on both sides of the base material, and thereafter, the step is performed as needed, and the step is performed as a cutting step S14.

In the thermal expansion layer forming step S11, the thickness t is set on one surface (upper side) of the substrate 1₁The 1 st thermal expansion layer 21 is formed on the other surface (lower side) with a thickness t₂(t₁＝t₂) The 2 nd thermal expansion layer 22 is formed. Method for forming each of thermal expansion layers 21 and 22, and thermal expansion according to embodiment 1The bulge forming step S11 is the same. Then, in the release layer forming step S12, the release layer 31 is formed on each of the thermally expandable layers 21 and 22, and in the ink receiving layer forming step S13, the ink receiving layer 4 is formed on each of the release layers 31 and 31 on both sides. For example, after the 1 st thermally-expansible layer 21, the release layer 31, and the ink-receiving layer 4 are formed in this order on one surface of the substrate 1, the 2 nd thermally-expansible layer 22, the release layer 31, and the ink-receiving layer 4 may be formed in this order on the other surface of the substrate 1. In the cutting step S14, the base material 1 on which the thermal expansion layers 21 and 22 and the like are formed is cut into thermal expansion layer-covered resin sheets 10D (see fig. 18) having a size corresponding to the printer used in the subsequent printing step S21, in the same manner as in embodiment 1.

In the printing step S21, as shown in fig. 20A and 16B, the photothermal conversion members 51 and 52 are formed by printing lines with black ink on the ink receiving layers 4 and 4 with the thermal expansion layer covering both sides of the resin sheet 10D. The photothermal conversion members 51 and 52 are formed on the respective printing surfaces at positions serving as the convex folding lines. The photothermal conversion member 51 on one surface side and the photothermal conversion member 52 on the other surface side of the thermal expansion layer-coated resin sheet 10D have the same structure as the photothermal conversion member 5 of embodiment 1. The photothermal conversion member 51 and the photothermal conversion member 52 are printed at the same black density with the same amount of light irradiated on both sides by the light irradiation device 7B in order to generate heat at the same temperature in the subsequent light irradiation step S24. In addition, the photothermal conversion element 51 or the photothermal conversion element 52 is preferably not formed at the intersection or junction of the convex folding line and the concave folding line (photothermal conversion element 51 and photothermal conversion element 52). When both the photothermal conversion members 51 and 52 are formed in the same region in plan view, the thermally-expansible layer-covering resin sheet 10D is excessively heated to a high temperature in the subsequent light irradiation step S24, and the thermally- expansible layers 21 and 22 may be excessively expanded, and the substrate 1 may be perforated. In addition, as in embodiment 1, the outline lines (thick lines in fig. 16B) to be the cut lines used in the cutting step S23 may be printed simultaneously with the photothermal conversion member 51 or photothermal conversion member 52.

In the cutting step S23, the thermal expansion layer-coated resin sheet 10D on which the photothermal conversion members 51 and 52 are formed is cut into an expanded shape of the sheet molded product 13 by a contour line indicated by a thick line in fig. 16B.

In the light irradiation step S24, the cut thermal expansion layer-coated resin sheet 10D is irradiated with light on both sides by the light irradiation device 7B. The photothermal conversion member 51 generates heat due to light from above, the 1 st thermal expansion layer 21 is heated, and further heat propagates from the surface of the 1 st thermal expansion layer 21 in the thickness direction (downward) so that the substrate 1 is heated. In addition, the photothermal conversion member 52 generates heat due to light from below, the 2 nd thermal expansion layer 22 is heated, and further heat propagates from the surface of the 2 nd thermal expansion layer 22 in the thickness direction (upward) to heat the substrate 1. Thus, as shown in fig. 20B, in the same manner as in embodiment 1 (see fig. 8D), directly below the photothermal conversion member 51, the 1 st thermally-expansible layer 21 expands, the base material 1 plastically deforms, and the thermally-expansible layer-covering resin sheet 10D bends and bends toward the 2 nd thermally-expansible layer 22 side on both sides of the line (photothermal conversion member 51). Further, immediately above the photothermal conversion member 52, the 2 nd thermally-expansible layer 22 expands, the base material 1 plastically deforms, and the thermally-expansible layer-covering resin sheet 10D bends and bends toward the 1 st thermally-expansible layer 21 side on both sides of the line (photothermal conversion member 52). After the irradiation of the heat-expandable-layer-covering resin sheet 10D with light is stopped, the base material 1 is cooled to less than the thermal deformation temperature T_DThereby, the deformation of the thermal expansion layer covering resin sheet 10D is completed.

Here, directly below the photothermal conversion member 51, the heat from the photothermal conversion member 51 propagates through the 1 st thermal expansion layer 21 and the substrate 1 in this order, and further propagates through the 2 nd thermal expansion layer 22. The heating temperature (maximum temperature) of the 2 nd thermal expansion layer 22 directly below the photothermal conversion element 51 is lower than that of the 1 st thermal expansion layer 21, so that even if it is heated to expand, the amount of expansion is suppressed to be smaller than that of the 1 st thermal expansion layer 21. Ideally, it is preferable that the 2 nd thermally-expansible layer 22 is not expanded, that is, does not reach the expansion-starting temperature T of the thermally- expansible layers 21, 22_EsThe above. On the other hand, since the 1 st thermally-expansible layer 21 is preferably expanded by a larger amount, as described in embodiment 1, the heating temperature of the 1 st thermally-expansible layer 21 is preferably set to the maximum temperature of the thermally-expansible layers 21 and 22Large expansion temperature T_EmaxNearby. Similarly, it is preferable that the 1 st thermal expansion layer 21 is expanded by a smaller amount than the 2 nd thermal expansion layer 22 directly above the photothermal conversion element 52, and the 2 nd thermal expansion layer 22 is expanded by a larger amount. Accordingly, the photothermal conversion members 51, 52 are preferably designed to have a black density at the maximum expansion temperature T, as in the photothermal conversion member 5 of embodiment 1_EmaxThe vicinity generates heat. In the light irradiation step S24, it is preferable that the photothermal conversion members 51 and 52 and the 1 st or 2 nd thermal expansion layer 21 or 22 closest thereto be cooled naturally by stopping the light irradiation promptly after reaching the highest temperature, and the 2 nd or 1 st thermal expansion layer 22 or 21 whose temperature increase is delayed through the substrate 1 does not reach the expansion start temperature T_EsAnd is most preferably cooled. Therefore, it is preferable that the heating rate (the temperature rise rate of the photothermal conversion members 51, 52) be high, and the output, the transport speed, and the like of the light source 7a of the light irradiation device 7B are set so as to achieve such temperature transition. In addition, the materials of the base material 1 and the thermal expansion layers 21, 22, etc. are selected so that the base material 1 is heated to the thermal deformation temperature T under such conditions_DThe above.

In the ink removing step S25, each of the two surfaces of the resin sheet 10D is covered with the curved thermally-expansible layer, and the ink-receiving layer 4 is peeled off by the peeling layer 31 in the same manner as in embodiment 1, thereby obtaining a sheet molded article 13 shown in fig. 17. The sheet molded article 13 is completed by setting the overlapping region 1m (see fig. 16B) as a bonding region, bonding the front surface (1 st thermal expansion layer 21) and the back surface (2 nd thermal expansion layer 22) opposite to one end of the overlapping region 1m with an adhesive to form a cylindrical body, and adjusting the shape as shown in fig. 16A.

(modification example)

The sheet molded article 13 may be held in a state where the photothermal conversion members 51, 52 are adhered along the ridge lines on both sides or one side, depending on the application such as a trial. In this case, the thermally-expansible layer-covering resin sheet 10D may not have the release layer 31 on both sides or may not have the release layer 31 on one side.

When the ink receiving layer 4 is removed in the ink removing step S25, the sheet molded article 13 may be configured only by the substrate 1 that is bent, as in the sheet molded article 11A (see fig. 10) according to the modification of embodiment 1, by peeling off the thermal expansion layers 21 and 22 therebelow. Therefore, the thermally-expansible layer-covering resin sheet 10D includes a release layer 31A between the base 1 and each of the thermally- expansible layers 21 and 22, instead of the release layer 31. Such a sheet molded article 13 can be produced in the same manner as the thermal expansion layer-coated resin sheet 10B (see fig. 11) and the sheet molded article 11A according to the modification of embodiment 1. Further, for example, it is also possible to manufacture a sheet molded article 13 (not shown) having the release layer 31A only between the 2 nd thermal expansion layer 22 and the substrate 1, the 1 st thermal expansion layer 21 on one surface, and the substrate 1 exposed on the other surface.

In the case where the substrate 1 is soft or has low rigidity such as a small thickness, and is not broken or the like even when the bent fold line is stretched by an external force and returned to flat and is bent again, the sheet molded article 13 can be produced by irradiating one surface of each of the thermal expansion layer-covered resin sheets 10D with light using the light irradiation device 7A (see fig. 6) in the light irradiation step S24. That is, after the 1 st light irradiation, the curved thermal expansion layer-coated resin sheet 10D is returned to flat, and then the 2 nd light irradiation is performed.

In the printing step S21, as shown in fig. 21, the light lines (hereinafter, gray lines) 52l and 51l having low black density may be printed on the surfaces of the photothermal conversion members 51 and 52 on the opposite sides of the same region in plan view. That is, on both sides of the same region of the thermal expansion layer-coated resin sheet 10D, lines (photothermal conversion members 51, 52) having a high black density and gray lines 52l, 51l are formed, respectively. The gray lines 52l and 51l are set so that the 1 st thermal expansion layer 21 or the 2 nd thermal expansion layer 22 which is closest to the light irradiation step S24 is heated to the expansion starting temperature T_EsBlack concentration at low temperature. When the thermally-expansible layer-coated resin sheet 10D is irradiated with light from both sides in the light irradiation step S24, the base material 1 is effectively heated to the thermal deformation temperature T because the light is heated to some extent not only from the photothermal conversion members 51 and 52 but also from the gray lines on the opposite sides thereof_DThe above is effective particularly when the substrate 1 is thick.

(modification of embodiment 1)

The heating of the black lines and the gray lines printed on both sides by the light irradiation device 7B as in the modification described above can also be applied to the production of the sheet molded articles 11 and 11A according to embodiment 1 and the modification thereof. That is, the ink receiving layer 4 is provided so that both sides can be printed as in the case of the thermally expandable layer-coated resin sheet 10C (see fig. 12), and in the printing step S21, the photothermal conversion member 5 is formed on the front surface and the photothermal conversion member 5A is formed on the rear surface in the same region in plan view. Preferably, the black density of each of the photothermal conversion members 5, 5A is set according to the thermal properties of each of the thermal expansion layer 2 and the substrate 1. Thus, when light is irradiated from both sides in the light irradiation step S24, the heat expansion layer 2 is transferred with heat from the photothermal conversion element 5 directly above, and the substrate 1 is transferred with heat mainly from the photothermal conversion element 5A directly below and also from the photothermal conversion element 5 directly above via the heat expansion layer 2, so that both the heat expansion layer 2 and the substrate 1 are easily heated to the appropriate temperatures (maximum expansion temperature T) of each of them_EmaxThermal deformation temperature T_DAbove). As a result, the thermal expansion layer-coated resin sheet 10(10B) can be bent appropriately, and particularly, when the substrate 1 is thick, the thermal deformation temperature T can be set appropriately_DThis is effective in the case of relatively high temperature.

[ 4 th embodiment ]

The three-dimensional shaped object of embodiment 3 and its modified example is formed in a shape in which the convex folds and the concave folds are mixed, and therefore, the three-dimensional shaped object can be manufactured by covering both surfaces of the base material with the thermal expansion layer and irradiating both surfaces with light. Hereinafter, a method for manufacturing a three-dimensional shaped object according to embodiment 4 of the present invention will be described. The same elements as those in the above-described embodiment (see fig. 1 to 20) are denoted by the same reference numerals, and description thereof is omitted.

In the method for producing a three-dimensional shaped object according to the present embodiment, the obtained sheet molded article (three-dimensional shaped object) 13 has the shape and structure shown in fig. 16A, 16B, and 17, as in embodiment 3. On the other hand, in the present embodiment, the sheet molded article 13 can be produced from the thermally-expansible layer-coated resin sheet 10D (see fig. 18) in the same manner as in embodiment 3, but since the photothermal conversion member is formed only on one side in the production process and light is irradiated, it can be produced from the thermally-expansible layer-coated resin sheet 10E (see fig. 22A) having the ink-receiving layer 4 on one side. Specifically, the thermally-expansible layer-covering resin sheet 10E has a structure in which the release layer 31 and the ink-receiving layer 4 are laminated only on the 1 st thermally-expansible layer 21 side, that is, the release layer 31 and the ink-receiving layer 4 on the 2 nd thermally-expansible layer 22 side are removed from the thermally-expansible layer-covering resin sheet 10D, and the respective elements are as described in embodiment 3.

(method of producing sheet molded article)

The method for producing a sheet molded article according to the present embodiment will be described with reference to fig. 7, 22A, and 22B, and with reference to fig. 16A and 16B as appropriate. Fig. 22A and 22B are schematic views for explaining the method for producing a three-dimensional shaped object according to embodiment 4 of the present invention, in which fig. 22A shows a cross-sectional view in a printing step and fig. 22B shows a cross-sectional view in a light irradiation step. As shown in fig. 7, the method of manufacturing a sheet molded article according to the present embodiment sequentially includes a thermal expansion layer-covered resin sheet manufacturing step S10 of manufacturing a thermal expansion layer-covered resin sheet 10E, a printing step S21, a cutting step S23, a light irradiation step S24, and an ink removal step S25. The thermally-expansible layer-covering resin sheet manufacturing step S10 is performed by sequentially performing the thermally-expansible layer forming step S11, the release layer forming step S12, and the ink-receiving layer forming step S13, and then performing the cutting step S14 as needed, in the same manner as in embodiment 1, but the thermally-expansible layer forming step S11 is performed on both sides of the base material. In addition, in the production of the sheet formed article of the present embodiment, the apparatus used in the production of the sheet formed article of embodiment 1 can be used.

In the thermal expansion layer forming step S11, one surface (upper surface) of the substrate 1 is formed to have a thickness t, as in embodiment 3₁The 1 st thermal expansion layer 21 is formed on the other surface (lower surface) with a thickness t₂(t₁＝t₂) The 2 nd thermal expansion layer 22 is formed. Then, in the release layer forming step S12, the release layer 31 is formed on the 1 st thermal expansion layer 21, and in the ink receiving layer forming step S13, the release layer 31 is formed on the substrateAn ink receiving layer 4. In the cutting step S14, as in embodiment 1, the base material 1 on which the thermally- expansible layer 21, 22 and the like are formed is cut to obtain a thermally-expansible layer-coated resin sheet 10E having a size corresponding to the printer used in the subsequent printing step S21 (see fig. 22A).

In the printing step S21, as shown in fig. 22A and 16B, the photothermal conversion members 51A and 52A ( photothermal conversion members 51 and 52 in fig. 16B) are formed by printing lines of black ink on the ink receiving layer 4 having the thermal expansion layer covering one surface side of the resin sheet 10E. The thermal expansion layer covers the printing surface (one surface side) of the resin sheet 10E, and the photothermal conversion member 51A is a convex fold line and the photothermal conversion member 52A is a concave fold line. The photothermal conversion members 51A, 52A have the same configuration as the photothermal conversion member 5 of embodiment 1, but the photothermal conversion member 51A is formed to have a lower black density (lighter) than the photothermal conversion member 52A. This is to cause the photothermal conversion member 52A to generate heat at a high temperature in the subsequent light irradiation step S24. Specifically, as described in the light irradiation step S24, the photothermal conversion member 51A is heated to the expansion start temperature T so that the nearest 1 st thermal expansion layer 21 is expanded directly below by heat generation_EsAbove, preferably at the maximum expansion temperature T_EmaxAnd heating the substrate 1 to a heat distortion temperature T_DThe above. On the other hand, the photothermal conversion element 52A heats the 1 st thermally-expansible layer 21 immediately below to more than the maximum expansion temperature T by heat generation_EmaxHeating the substrate 1 to a heat distortion temperature T_DIn this way, the 2 nd thermally-expansible layer 22 is further heated to the expansion-starting temperature T_EsThereby expanding it. The photothermal conversion members 51A and 52A are set to have black densities so that the same amount of light is irradiated in the light irradiation step S24 and heat is generated at such a temperature. Further, since the 2 nd thermal expansion layer 22 expands in a region that expands to some extent in the line width direction directly below the photothermal conversion member 52A, it is preferable that the photothermal conversion member 52A be designed to have a small line width within a range where the heated region of the substrate 1 is secured, as in the photothermal conversion member 5A of the modification example of the 1 st embodiment. In addition, also can be combined withSimilarly to embodiment 1, the outline (thick line in fig. 16B) to be the cut line in the subsequent dicing step S23 is printed together with the photothermal conversion members 51A and 52A.

In the cutting step S23, the thermally-expansible layer-coated resin sheet 10E on which the photothermal conversion members 51A and 52A are formed is cut into the developed shape of the sheet molded product 13 by a contour line indicated by a thick line in fig. 16B, as in embodiment 3.

In the light irradiation step S24, the cut thermal expansion layer-coated resin sheet 10E is irradiated with light by the light irradiation device 7(7A) onto the surface (one surface) on which the photothermal conversion members 51A and 52A are printed. Then, the photothermal conversion members 51A, 52A generate heat at a temperature corresponding to the respective black densities, and the heat propagates through the 1 st thermal expansion layer 21, the substrate 1, and the 2 nd thermal expansion layer 22 in this order. As shown in fig. 22B, directly below the photothermal conversion member 51A, the 1 st thermal expansion layer 21 expands, the substrate 1 plastically deforms, and the thermal expansion layer-covering resin sheet 10E bends and curves toward the 2 nd thermal expansion layer 22 side on both sides of the line (photothermal conversion member 51A), as in the case of directly below the photothermal conversion member 51 in embodiment 3 (see fig. 20B). The 2 nd thermally-expansible layer 22 has a lower maximum temperature than the 1 st thermally-expansible layer 21, so that the amount of expansion is small, and ideally does not reach the expansion-starting temperature T_EsBut not expanded. On the other hand, in order to expand the 1 st thermal expansion layer 21 more, the photothermal conversion member 51A is preferably set to have black density so as to generate heat to the maximum expansion temperature T_EmaxNearby.

Further, immediately below the photothermal conversion element 52A, the base material 1 reaches the thermal deformation temperature T_DAs described above, the 2 nd thermally-expansible layer 22 reaches the expansion-starting temperature T_EsThe above expansion. On the other hand, the 1 st thermal expansion layer 21 closest to the photothermal conversion element 52A is heated to a higher temperature to exceed the maximum expansion temperature T_Emax. The microcapsules are usually heated above the maximum expansion temperature T_EmaxThe high temperature of (2) causes the volatile solvent contained therein to permeate through the shell at a high rate and diffuse, so that the expansion rate decreases, and when the volatile solvent has already expanded, the volatile solvent shrinks. Therefore, the 1 st thermal expansion layer 21 has its expansion rate directly below the photothermal conversion element 52ALess than the maximum expansion rate and thus a lower expansion rate than the 2 nd thermally-expansible layer 22. As a result, the 2 nd thermally-expansible layer 22 expands more than the 1 st thermally-expansible layer 21, so the load acting on the substrate 1 is high, and as shown in fig. 22B, the thermally-expansible layer-covering resin sheet 10E bends and bends toward the 1 st thermally-expansible layer 21 side on both sides of the line (the photothermal conversion member 52A). Further, immediately below the photothermal conversion member 52A, the 1 st thermally-expansible layer 21 that is closest thereto is first heated to the expansion start temperature T_Es. However, by being heated at a high speed, the maximum expansion temperature T is further increased to a temperature much higher than the maximum expansion temperature T before the 1 st thermally-expansible layer 21 expands to plastically deform the base material 1_EmaxOr the 2 nd thermal expansion layer 22 reaches a temperature exceeding the expansion rate of the 1 st thermal expansion layer 21.

In this way, it is preferable that the 1 st thermal expansion layer 21 closest to the photothermal conversion member 52A be at the maximum expansion temperature T higher than the thermal expansion layers 21 and 22 immediately below the photothermal conversion member 52A_EmaxHigh temperature, temperature (T) at which expansion rate is sufficiently reduced_Es+ 50-80 ℃ or higher). Therefore, as for the photothermal conversion member 52A, it is preferable to design the black density so that heat is generated to the maximum expansion temperature T_EmaxThe above-mentioned high temperature. In addition, the 2 nd thermal expansion layer 22 is preferably set to the maximum expansion temperature T so that the expansion amount is larger_EmaxNearby and not increasing the temperature continuously, specifically (T)_Emax+5 ℃ or less, more preferably T_EmaxThe following. In addition, since the portion directly below the photothermal conversion member 52A is heated to a higher temperature than the portion directly below the photothermal conversion member 51A, the base material 1 can be plastically deformed with a lower load, and even if the 1 st thermal expansion layer 21 expands to some extent and the difference in expansion amount from the 2 nd thermal expansion layer 22 is small, the base material 1 can be bent equally to the portion directly below the photothermal conversion member 51A.

In order to show the above-described temperature gradient in the 1 st thermal expansion layer 21 and the 2 nd thermal expansion layer 22 directly below the photothermal conversion members 51A, 52A, respectively, it is preferable that the heating rate (the temperature increase rate of the photothermal conversion members 51A, 52A) be high, and that the photothermal conversion members 51A, 52A be cooled promptly after reaching the highest temperature, as in embodiment 3.

In the ink removing step S25, the surface of the resin sheet 10E is covered with the curved thermally-expansible layer, and the ink-receiving layer 4 is peeled off by the peeling layer 31 in the same manner as in embodiment 1, thereby obtaining a sheet molded article 13 shown in fig. 17. The sheet molded article 13 is assembled as shown in fig. 16A and completed as in embodiment 3.

(modification example)

The sheet molded article 13 can maintain the state where the photothermal conversion members 51A and 52A are attached along the ridge line depending on the application, such as the trial operation, as in embodiment 3, and in this case, the thermally-expansible layer-covering resin sheet 10E may not have the release layer 31. In addition, when the ink receiving layer 4 is removed in the ink removing step S25, the sheet molded product 13 may be composed of the substrate 1 which is bent and the 2 nd thermally-expansible layer 22 covering one side thereof, in which the 1 st thermally-expansible layer 21 under the ink receiving layer is peeled off together. Alternatively, the 2 nd thermally-expansible layer 22 may be peeled off, and may be constituted only by the base material 1 (not shown) as in the sheet molded article 11A (see fig. 10) of the modification of embodiment 1. Therefore, the thermally-expansible layer-covering resin sheet 10E includes a release layer 31A between the substrate 1 and the 1 st thermally-expansible layer 21 instead of the release layer 31, or further includes a release layer 31A between the substrate 1 and the 2 nd thermally-expansible layer 22. Such a sheet molded article 13 can be produced in the same manner as the thermal expansion layer-coated resin sheet 10B (see fig. 11) and the sheet molded article 11A according to the modification of embodiment 1.

In the present embodiment, the expansion rates of the 1 st thermal expansion layer 21 and the 2 nd thermal expansion layer 22 are different and the expansion amounts are different, but in order to make the difference between the expansion amounts larger and make it easy to bend the base material 1, it is also possible to provide the initial thickness t from the one shown in fig. 23₁、t₂The different thermal expansion layers 21A and 22A are formed by covering the resin sheet 10F. Specifically, the initial thickness t of the 2 nd thermal expansion layer 22A having a large distance to the printing surface (ink receiving layer 4) of the thermal expansion layer-coated resin sheet 10F is set to be larger₂Is set to be thicker (t)₁＜t₂). Thus, the obtained sheet molded article (three-dimensional shaped article) 13A was thermally expanded on the ridge line other than the ridge line as shown in the sectional view of FIG. 24The thermal expansion layer 22A is formed thicker than the swelling layer 21A.

The method of manufacturing the sheet molded article 13A from the thermal expansion layer-covered resin sheet 10F is the same as that of embodiment 4 (see fig. 22A and 22B). That is, the thermally-expansible layer covers the resin sheet 10F, and is bent toward the 2 nd thermally-expansible layer 22A by the expansion of the 1 st thermally-expansible layer 21A directly below the photothermal conversion member 51A. On the other hand, directly below the photothermal conversion element 52A, the 2 nd thermal expansion layer 22A expands at a high expansion rate, preferably at the maximum expansion rate. At this time, even if the 1 st thermal expansion layer 21A expands at the same expansion rate as the 2 nd thermal expansion layer 22A, the 2 nd thermal expansion layer 22A having a large initial thickness has a large expansion amount (absolute amount), and therefore bends toward the 1 st thermal expansion layer 21A side. Therefore, even if the thermal expansion layers 21A, 22A have a temperature exceeding the maximum expansion temperature T_EmaxThe sheet molded article 13A having both convex and concave folds can be produced by irradiating only one surface with light without a structure (such as microcapsules) having a low expansion ratio at high temperature.

In the thermal expansion layer-covering resin sheet 10F, the 1 st and 2 nd thermal expansion layers 21A and 22A are not limited to the initial thickness t as long as the expansion amounts (absolute amounts) are different at the same expansion rate₁、t₂The difference in (2) may be adjusted by changing the formulation of the microcapsules, for example, so that the expansion amount of the 2 nd thermally-expansible layer 22A is larger at each maximum expansion ratio.

In the method of manufacturing a sheet molded article according to embodiment 4, the thermal expansion layers 21 and 22 sandwiching the substrate 1 from both sides are expanded at a relatively high expansion ratio on a desired side by utilizing a temperature gradient generated by a difference in distance from the photothermal conversion members 51A and 52A on one side, and the convex fold and the concave fold are freely manufactured. A method for manufacturing a sheet molded article according to a modification of embodiment 4 will be described below.

In the present modification, the sheet molded article 13 is manufactured by covering the resin sheet 10G with the thermal expansion layer shown in fig. 25. Fig. 25 is a cross-sectional view schematically showing a structure in which a thermally expandable layer covering a resin sheet is used as a material of a three-dimensional structure according to a modification example of embodiment 4 of the present invention. The thermal expansion layer-covering resin sheet 10G is a flat plate-like member having a uniform thickness, and has a 1 st thermal expansion layer 21B laminated on one surface of the base 1, a 2 nd thermal expansion layer 22B laminated on the other surface, and a release layer 31 and an ink-receiving layer 4 laminated in this order on the 2 nd thermal expansion layer 22B. The thermal expansion layer-covered resin sheet 10G is a printed matter for printing black ink constituting the photothermal conversion members 51B, 52B on the ink receiving layer 4, similarly to the thermal expansion layer-covered resin sheet 10E of the above embodiment and the like, and in this modification, the surface on the other surface side on which the ink receiving layer 4 is formed is a printed surface.

The respective structures of the substrate 1, the release layer 31, and the ink receiving layer 4 are as described in embodiments 1 and 3. The 1 st and 2 nd thermal expansion layers 21B, 22B (appropriately summarized as the thermal expansion layers 21B, 22B) have the same structures as the thermal expansion layers 21, 22 of the 3 rd and 4 th embodiments, respectively, and have initial thicknesses t₁、t₂Same (t)₁＝t₂). However, the 1 st thermal expansion layer 21B and the 2 nd thermal expansion layer 22B start to expand at a temperature T1_Es、T2_EsIs formulated in a different manner, the expansion start temperature T2 of the 2 nd thermal expansion layer 22B_EsExpansion starting temperature T1 with the 1 st thermally-expansible layer 21B_EsCompared with high temperature (T1)_Es＜T2_Es). In addition, the maximum expansion temperature T1 of the 1 st thermal expansion layer 21B_EmaxIt is preferable that the maximum expansion temperature T2 with the 2 nd thermally-expansible layer 22B is_EmaxCompared with low temperature (T1)_Emax＜T2_Emax) More preferably, the expansion start temperature T2 with the 2 nd thermally-expansible layer 22B_EsCompared with low temperature (T1)_Emax＜T2_Es). In addition, it is preferable that the thermal deformation temperature T of the thermoplastic resin constituting the substrate 1_DLess than the expansion start temperature T2 of the 2 nd thermally-expansible layer 22B_Es(T_D＜T2_Es). The thermal properties of the base material 1 and the thermal expansion layers 21B and 22B in this modification will be described in detail by the following production method.

(method of producing sheet molded article)

A method for manufacturing a sheet molded article according to this modification will be described with reference to fig. 26A and 26B, as appropriate, and fig. 7. Fig. 26A and 26B are schematic views for explaining a three-dimensional shaped object manufacturing method according to a modification example of embodiment 4 of the present invention, in which fig. 26A is a cross-sectional view in a printing step, and fig. 26B is a cross-sectional view in a light irradiation step. As shown in fig. 7, the method of manufacturing a sheet molded article according to this modification includes a thermal expansion layer-covered resin sheet manufacturing step S10 of manufacturing a thermal expansion layer-covered resin sheet 10G, a printing step S21, a cutting step S23, a light irradiation step S24, and an ink removal step S25 in this order. In the thermal expansion layer-covering resin sheet manufacturing step S10, as in the above embodiment, the thermal expansion layer forming step S11, the peeling layer forming step S12, and the ink receiving layer forming step S13 are performed in this order, and then, if necessary, the cutting step S14 is performed.

In the thermal expansion layer forming step S11, one surface (upper surface) of the substrate 1 is formed to have a thickness t₁The 1 st thermal expansion layer 21B is formed on the other surface (lower surface) with a thickness t₂(t₁＝t₂) The 2 nd thermal expansion layer 22B is formed. The method of forming each of the thermal expansion layers 21B and 22B is the same as the thermal expansion layer forming step S11 of embodiment 1. In this modification, since the 1 st thermal expansion layer 21B and the 2 nd thermal expansion layer 22B are made of different materials, pastes are prepared separately. Then, in the release layer forming step S12, the release layer 31 is formed on the 2 nd thermally-expansible layer 22B, and in the ink-receiving layer forming step S13, the ink-receiving layer 4 is formed on the release layer 31. In the cutting step S14, as in embodiment 1, the base material 1 on which the thermally- expansible layer 21B, 22B, etc. are formed is cut to obtain a thermally-expansible layer-coated resin sheet 10G (see fig. 25) having a size corresponding to the printer used in the subsequent printing step S21.

In the printing step S21, as shown in fig. 26A and 16B, the photothermal conversion members 51B and 52B ( photothermal conversion members 51 and 52 in fig. 16B) are formed by printing lines with black ink on the ink receiving layer 4 on the other surface side of the thermal expansion layer-coated resin sheet 10G. In fig. 26A and 26B, the printing surface is shown facing upward. The thermal expansion layer covers the printing surface (the other surface side) of the resin sheet 10G, and light is emittedThe thermal conversion member 51B is a concave fold line, and the photothermal conversion member 52B is a convex fold line. The photothermal conversion members 51B, 52B are similar to the photothermal conversion members 51A, 52A of the above embodiments, respectively, and the photothermal conversion member 51B is formed to have a lower black density (lighter) than the photothermal conversion member 52B. Specifically, as described in the light irradiation step S24, the photothermal conversion member 51B heats the substrate 1 to the thermal deformation temperature T directly below by heat generation_DAs described above, the 1 st thermally-expansible layer 21B having the low expansion-starting temperature among the thermally- expansible layers 21B and 22B is heated to the expansion-starting temperature T1 to expand_EsAbove, it is preferably heated to the maximum expansion temperature T1_EmaxNearby. On the other hand, the photothermal conversion member 52B heats the 2 nd thermally-expansible layer 22B to the expansion start temperature T2 in order to expand it immediately below by heat generation_EsAbove, it is preferably heated to the maximum expansion temperature T2_EmaxAnd heating the substrate 1 to a heat distortion temperature T_DIn this way, the 1 st thermally-expansible layer 21B is further heated to exceed the maximum expansion temperature T1_EmaxHigh temperature of (2). The photothermal conversion members 51B and 52B are designed to emit the same amount of light in the light irradiation step S24 and generate heat to the temperature described above. Further, since the 1 st thermal expansion layer 21B expands in a region that expands to some extent in the linear width direction directly below each of the photothermal conversion members 51B, 52B, it is preferable that the photothermal conversion member 51B has a narrow line width in a range where the heated region of the substrate 1 is secured, as in the photothermal conversion member 5A of the modification example of the 1 st embodiment. In addition, as in embodiment 1, a contour line (a thick line in fig. 16B) serving as a cut line for the subsequent dicing step S23 may be printed together with the photothermal conversion members 51B and 52B.

In the cutting step S23, the thermal expansion layer-coated resin sheet 10G on which the photothermal conversion members 51B, 52B are formed is cut along a contour line indicated by a thick line in fig. 16B, and the developed shape of the sheet molded product 13 is cut, as in the above-described embodiment.

In the light irradiation step S24, the cut thermal expansion layer is covered with the resin sheet 10G,the surface (the other surface) on which the photothermal conversion members 51B, 52B are printed is irradiated with light by the light irradiation device 7 (7A). Then, the photothermal conversion members 51B, 52B generate heat at temperatures corresponding to the respective black densities, and the heat propagates through the 2 nd thermal expansion layer 22B, the substrate 1, and the 1 st thermal expansion layer 21B in this order. Immediately below the photothermal conversion element 51B, the substrate 1 reaches the thermal deformation temperature T_DThus, the 1 st thermally-expansible layer 21B reaches the expansion-starting temperature T1_EsThe above expansion. As a result, as shown in fig. 26B, the thermally-expansible layer-covering resin sheet 10G is bent and bent toward the 2 nd thermally-expansible layer 22B side on both sides of the line (the photothermal conversion member 51B). The closest 2 nd thermal expansion layer 22B of the photothermal conversion member 51B is low in expansion temperature range, has a smaller expansion amount than the 1 st thermal expansion layer 21B, and ideally does not reach the expansion start temperature T2_EsBut not expanded. On the other hand, the 1 st thermally-expansible layer 21 is preferably brought to the maximum expansion temperature T1 for greater expansion_EmaxNearby. Therefore, the photothermal conversion element 51B is designed to have a black density such that heat is generated to T1_EsAbove and T_DAbove and below ratio T2_EmaxSufficiently low temperature, preferably designed to generate heat to less than T2_EsIs more preferably designed to generate heat to T1_EmaxThe near black density.

Further, immediately below the photothermal conversion element 52B, the 2 nd thermally-expansible layer 22B reaches the expansion start temperature T2_EsExpands as above, and the substrate 1 reaches the thermal deformation temperature T_DThe above. On the other hand, the 1 st thermally-expansible layer 21B reaches the temperature exceeding the maximum expansion temperature T_E1maxHas a lower expansion rate than the 2 nd thermally-expansible layer 22B. Therefore, as shown in fig. 26B, the thermally-expansible layer-covering resin sheet 10G is bent and bent toward the 1 st thermally-expansible layer 21B on both sides of the line (the photothermal conversion member 52B). In the 2 nd thermally-expansible layer 22B, in order to increase the expansion amount, it is preferable to reach the maximum expansion temperature T2_EmaxIn the vicinity, it is preferable that the 1 st thermal expansion layer 21B has a temperature at which the expansion rate is sufficiently lowered (T1)_Es+ 50-80 ℃ or higher). Therefore, with respect to the photothermal conversion member 52B, the black density is designed to be heated to T2_EsAbove (and T)_DAbove) and exceeds T1_EmaxPreferably, the heat generation ratio is designed to be T1_EmaxSufficiently high temperature and T2_EmaxThe near black density.

Immediately below the photothermal conversion member 52B, the thermal deformation temperature T is reached when the substrate 1 reaches the thermal deformation temperature T in order to prevent plastic deformation of the substrate 1 due to expansion of the 1 st thermal expansion layer 21B_DAnd the 1 st thermal expansion layer 21B reaches the expansion start temperature T1_EsBefore expanding to plastically deform the base material 1, the 1 st thermally-expansible layer 21B preferably reaches a temperature (highest temperature) at which the expansion ratio is sufficiently reduced, as in embodiment 4. Alternatively, it is preferable that the 2 nd thermally-expansible layer 22B reach the expansion-starting temperature T2_EsAnd begins to expand. Therefore, it is preferable that the heating rate (the temperature increase rate of the photothermal conversion members 51B, 52B) be high. In addition, as in embodiment 4, since the temperature directly below the photothermal conversion member 52B is heated to a higher temperature than the temperature directly below the photothermal conversion member 51B, the base material 1 can be plastically deformed under a lower load. The present modification is effective also in the case where a sufficient temperature gradient is not likely to occur between the thermal expansion layers 21B and 22B, for example, when the thickness of the base material 1 is small.

In the ink removing step S25, the surface of the resin sheet 10G is covered with the curved thermally-expansible layer, and the ink-receiving layer 4 is peeled off by the peeling layer 31 in the same manner as in the above-described embodiment, thereby obtaining the sheet molded article 13 shown in fig. 22. The sheet molded article 13 is assembled as shown in fig. 16A and completed as in embodiment 3.

In this modification as well, the sheet molded article 13 may be kept in a state where the photothermal conversion members 51B, 52B are adhered along the ridge line depending on the application, and in this case, the thermally-expansible layer-covering resin sheet 10G may not include the release layer 31, as in the case of embodiments 3 and 4. As described in the above embodiment, when the ink receiving layer 4 is removed in the ink removing step S25, the underlying 2 nd thermally-expansible layer 22B may be peeled off together, and the 1 st thermally-expansible layer 21B may be peeled off.

In this modification as well, similarly to embodiment 4, the base material 1 is made to be easily bent in order to make the difference in expansion amount largerThe initial thickness t of the thermal expansion layers 21B, 22B may be set to be as large as the thermal expansion layer-covering resin sheet 10F (see FIG. 23)₁、t₂Different. In detail, the initial thickness t of the 2 nd thermal expansion layer 22B whose expansion start temperature is high is set to be higher₂Is set to be thicker (t)₁＜t₂). Even if the 1 st thermal expansion layer 21B exceeds the maximum expansion temperature T_E1maxThe thermal expansion layer-covering resin sheet 10G is bent toward the 1 st thermal expansion layer 21B side and is bent because the expansion amount (absolute amount) of the 2 nd thermal expansion layer 22B is larger directly below the photothermal conversion member 52B. Alternatively, the expansion amount of the 2 nd thermally-expansible layer 22B may be adjusted so as to be larger at the respective maximum expansion rates by blending microcapsules or the like.

[ 5 th embodiment ]

Since the three-dimensional shaped object of the present invention is formed by bending when irradiated with light during the production process, when the size of the three-dimensional shaped object in the developed shape before irradiation is large, the region irradiated with light is bent in a state where the region not irradiated with light by the light irradiation device remains. In this case, as described in the modification of embodiment 1, light can be appropriately irradiated by being nipped and conveyed by the sheet loader, but conveyance becomes difficult depending on the shape. Further, it is preferable that the three-dimensional shaped object is not in contact with the apparatus when irradiated with light. Therefore, the light irradiation device is constituted so as to fix the position of the three-dimensional formation in a non-contact and definite manner in the region irradiated with light. Hereinafter, a method for manufacturing a three-dimensional shaped object according to embodiment 5 of the present invention will be described with reference to fig. 27 and 28. Fig. 27 is an external view schematically illustrating a light irradiation device used for manufacturing a three-dimensional object. Fig. 28 is a schematic view illustrating a method for manufacturing a three-dimensional shaped object according to embodiment 5 of the present invention, and is a plan view illustrating a cutting process. The same elements as those in the above-described embodiment (see fig. 1 to 26) are denoted by the same reference numerals, and description thereof is omitted.

(light irradiation device)

In the present embodiment, the light irradiation device 7C shown in fig. 27 is used in the light irradiation step S24. The light irradiation device 7C includes a light irradiation unit 71, a cooler 72 (not shown), a shield plate 73, a conveyance mechanism 8D, and a cutting mechanism 9. The light irradiation device 7C irradiates the upper surface of the object to be processed with light in the same manner as the light irradiation device 7 (see fig. 5) used in embodiments 1, 2, and 4, and the light irradiation section 71, the cooler 72, and the protection plate 73 have the same structure as the light irradiation device 7.

The conveying mechanism 8D conveys the object to be processed in one horizontal direction at a constant speed so as to pass through the light irradiation region. The conveying mechanism 8D includes a total of 4 sets of belt conveyors arranged above and below the object to be processed so as to be disposed at each of both edges and further sandwiched at least in the light irradiation region, in order to nip and convey the object to be processed having a predetermined size in the vicinity of both ends (both edges) in the conveying width direction. Therefore, the conveying mechanism 8D includes 4 belts 81A, drive pulleys (drive pulleys) 82, and tail pulleys 83, and further includes an idler pulley (idle pulley)87 in the upper 2 sets of belt conveyors, and is configured by a motor (not shown) or the like that rotationally drives the 4 drive pulleys 82. Further, a carry-in guide plate 75 and a conveying roller 85 of the light irradiation device 7A may be provided behind the conveying mechanism 8D.

The cutting mechanism 9 is a cutter (slider) that continuously cuts the object to be processed along the conveying direction at a predetermined position inside the conveying mechanism 8D in the conveying width direction, and includes an upper blade 91 and a lower blade 92 so as to sandwich the object to be processed from above and below in front of the light irradiation region and in the vicinity of both edges. The positions of the blades 91 and 92 in the conveying direction are set to be before the light irradiation region and after the position where the object to be processed (the thermally-expansible layer-covering resin sheet 10) starts to bend. The blades 91 and 92 are preferably provided so that the position thereof can be adjusted in the conveying width direction or in the conveying direction.

According to the light irradiation device 7C, the object to be processed is irradiated with light stably without being separated from the conveyance path in the light irradiation region, and since the object is not in contact with the members of the light irradiation device 7C and the like, the propagation state of heat is uniform, and expansion of the thermal expansion layer is not hindered. On the other hand, the object to be processed is cut at both edges held by the conveying mechanism 8D by the cutting mechanism 9 at a portion passing through the light irradiation region, and thus bending and deformation are not hindered. The light irradiation device 7C may be configured such that the light irradiation unit 71, the cooler 72, and the protection plate 73 are disposed upside down to irradiate light on the lower surface of the object to be processed, and may be configured to include 2 light irradiation units 71, coolers 72, and protection plates 73 to irradiate light simultaneously on both surfaces of the object to be processed.

When the light irradiation device 7C irradiates light, the thermal expansion layer-covering resin sheet 10 leaves a frame 10f in a frame shape on the periphery thereof in the cutting step S23 as shown in fig. 28, and is connected to the frame 10f by a tie bar (tiebar)10b without cutting a part of the contour line. The frame 10f is a portion to be held by the conveyance mechanism 8D of the light irradiation device 7C. The connecting bar 10b is provided to connect the thermal expansion layer-coated resin sheet 10 (before bending of the sheet molded article 11) to the frame 10f, and is cut by the cutting mechanism 9 of the light irradiation device 7C. Therefore, the connecting strip 10b is formed so as to be connected to both ends (both edges) in the conveying width direction of the frame 10f and extend from the contour line in a non-parallel manner to the conveying direction, and is preferably formed so as to extend in the conveying width direction. The interval (pitch) between the connecting strips 10b, 10b in the conveying direction is formed such that, when the connecting strip 10b is cut by the cutting mechanism 9, the connecting strip 10b at the rear thereof passes through the light irradiation region. Further, the connecting strip 10b is preferably connected to a portion of the assembled sheet molded article 11 that is not exposed on the front side.

In the light irradiation step S24, when the light irradiation device 7C irradiates the cut thermal expansion layer-covered resin sheet 10 with light, the portion that has passed through the light irradiation region is cut by the cutting mechanism 9 to allow the connecting bar 10b to start bending along the photothermal conversion member 5. After the light irradiation step S24, the resin sheet 10 is covered with the bent thermal expansion layer, and the remaining connecting bar 10b is cut out by cutting the contour line with scissors or the like.

(modification example)

In the above embodiment, the cutting mechanism is provided to the light irradiation device to mechanically cut both edges, but since the object to be treated is mainly made of a thermoplastic resin, both edges can be cut without using the cutting mechanism. Hereinafter, a method for manufacturing a three-dimensional shaped object according to a modification of embodiment 5 will be described with reference to fig. 29. Fig. 29 is a schematic view illustrating a method for manufacturing a three-dimensional shaped object according to a modification of embodiment 5 of the present invention, and is a plan view illustrating a cutting process. The same elements as those in the above-described embodiment (see fig. 1 to 27) are denoted by the same reference numerals, and description thereof is omitted.

In the present modification, the light irradiation device 7C (see fig. 27) used in the above embodiment can be used, but the cutting mechanism 9 is not required.

In the cutting step S23, as shown in fig. 29, the thermally expandable layer-coated resin sheet 10 is connected to the frame 10f by the connecting strip 10b without cutting a part of the outline, with the frame 10f remaining in a frame shape at the peripheral edge, as in the above-described embodiment. In this modification, the extending direction of the connecting bar 10b is not particularly limited, and the connecting bar may be connected to both ends of the frame 10f in the conveying direction. In addition, it is preferable that the connecting strip 10b is thin enough to maintain the connection. In the printing step S21, the lines 5d crossing the connecting strips 10b are printed with black ink together with the photothermal conversion element 5. The wire 5d generates heat when light is irradiated by the light irradiation device 7C, and melts the thermal expansion layer-covering resin sheet 10 (the base material 1 and the thermal expansion layer 2), thereby cutting the connecting bar 10 b. Therefore, the line 5d is formed by making the black density sufficiently high and making the line width thick. The position of the line 5d in the connecting strip 10b is not particularly formed, and may be on the contour line.

In the light irradiation step S24, the thermally-expansible layer-coated resin sheet 10 cut out as described above is irradiated with light by the light irradiation device 7C, and the portion that has passed through the light irradiation region starts to bend along the photothermal conversion member 5, and is melted directly below the wire 5d, and the connecting bar 10b is cut by a load that is to be applied to the bending. After the light irradiation step S24, the resin sheet 10 is covered with the bent thermal expansion layer, and the remaining connecting bar 10b is cut at the contour line with scissors or the like.

Examples 1 to 4 of the present inventionThe three-dimensional shaped object of the embodiment is a three-dimensional shape formed by bending a plane or a three-dimensional shape formed by a curved developable surface. However, since the thermoplastic resin constituting the base material is thermally deformed, it is also possible to manufacture a sheet molded article (not shown) having a surface close to a three-dimensional curved surface such as a spherical surface, in which a linear region where the photothermal conversion member is formed is a frame. The thermal expansion layer-coated resin sheet 10 is bent at each of the photothermal conversion members 5 in a narrow region between the photothermal conversion members 5, and is largely bent as a whole, and is gently bent in a large region, and therefore can be deformed into an arbitrary surface shape in accordance with the pattern of the photothermal conversion member 5, or the bending angle can be adjusted in accordance with the black density and line width of the photothermal conversion member 5. In particular, the base material 1 is heated to the thermal deformation temperature T directly below and in the vicinity of the photothermal conversion element 5_DSince the above deformation is easy, the space between the photothermal conversion members 5, 5 is formed narrow, and thus the photothermal conversion members can be deformed into a smoother curved surface.

As described above, according to the present invention, a desired three-dimensional shape can be obtained by bending and curving a resin sheet without using a die or the like.

The present invention is not limited to the above-described embodiments, and can be modified and implemented within a scope not departing from the gist of the present invention.