阅读说明：本技术 装饰片及其制造方法、显示装置 (Decorative sheet, method for manufacturing same, and display device ) 是由 杉山知德 金内和彦 中川英秋 永原孝行 于 2020-03-03 设计创作，主要内容包括：装饰片具备表面侧的表面粗糙度R1大于背面侧的表面粗糙度R2的原材料片、在原材料片的表面侧设置的第一粘接层、在原材料片的表面侧隔着第一粘接层设置的具有至少包含各自为一层以上的硬涂层、UV阻隔层的多层结构的薄膜层、在原材料片的背面侧设置的第二粘接层、以及在原材料片的背面侧隔着第二粘接层设置的片材支承层,各层一体化成一个片状,在第一粘接层与原材料片的表面侧的凹凸形状的谷之间的界面处存在空气层。(The decorative sheet comprises a raw material sheet having a surface roughness R1 of the front surface side larger than a surface roughness R2 of the back surface side, a first adhesive layer provided on the front surface side of the raw material sheet, a film layer provided on the front surface side of the raw material sheet via the first adhesive layer and having a multilayer structure including at least one hard coat layer and a UV barrier layer, a second adhesive layer provided on the back surface side of the raw material sheet, and a sheet support layer provided on the back surface side of the raw material sheet via the second adhesive layer, wherein the layers are integrated into one sheet, and an air layer is present at the interface between the first adhesive layer and the valleys of the uneven shape on the front surface side of the raw material sheet.)

1. A decorative sheet is provided with:

a raw material sheet having a surface roughness R1 of the surface side larger than a surface roughness R2 of the back surface side;

a first adhesive layer provided on a surface side of the raw material sheet;

a film layer provided on a surface side of the raw material sheet with the first adhesive layer interposed therebetween;

a second adhesive layer provided on the back surface side of the raw material sheet; and

a sheet supporting layer provided on the back surface side of the raw material sheet with the second adhesive layer interposed therebetween,

the film layer is a multilayer structure comprising at least a hard coat layer and a UV barrier layer each of which is one or more layers,

the raw material sheet, the first adhesive layer, the film layer, the second adhesive layer, and the sheet supporting layer are integrated into one sheet, and an air layer is present at an interface between the first adhesive layer and a valley of the uneven shape on the surface side of the raw material sheet.

2. The decorative sheet according to claim 1, wherein the surface roughness RA of the surface of the film layer opposite to the first adhesive layer, the surface roughness RB of the surface side of the raw material sheet, and the surface roughness RC of the surface of the sheet supporting layer on the second adhesive layer side satisfy the relationship RB > RA > RC.

3. The decorative sheet according to claim 1 or 2, wherein the sheet supporting layer contains at least 1 selected from a polymer film and a nonwoven fabric containing polyethylene terephthalate, an acrylic polymer, polycarbonate, or the like as a main component.

4. The decorative sheet according to any one of claims 1 to 3, further comprising: and a reinforcing layer containing a resin provided on the opposite side of the sheet supporting layer from the second adhesive layer.

5. The decorative sheet according to any one of claims 1 to 4, wherein an uneven shape different from that of the surface side of the raw material sheet when seen through from the normal direction is arranged on the surface of the film layer opposite to the first adhesive layer.

6. The decorative sheet according to any one of claims 1 to 5, further comprising: and a light source for irradiating light from the back side to the front side of the decorative sheet.

7. The decorative sheet according to any one of claims 1 to 6, wherein between the second adhesive layer and the sheet supporting layer are provided in this order:

a printing layer at least comprising more than 1 hiding layer and light diffusion layer;

a substrate for disposing the printing layer; and

and a fourth adhesive layer for bonding the substrate to the sheet supporting layer.

8. The decorative sheet according to any one of claims 1 to 7, wherein the raw material sheet is at least one raw material sheet selected from stone, wood, cork, cloth, and leather.

9. A display device is provided with:

the decorative sheet of any one of claims 1 to 8; and

and a contact operation control device provided on a surface of the decorative sheet opposite to the second adhesive layer, for a user to control an electronic device.

10. A display device is provided with:

the decorative sheet of any one of claims 1 to 8; and

and a noncontact operation control device provided on the side of the sheet supporting layer of the decorative sheet opposite to the second adhesive layer and configured to control an electronic device in accordance with a movement of a user's palm or arm.

11. A display device is provided with:

the decorative sheet of any one of claims 1 to 8; and

a contact type operation control device and a non-contact type operation control device for controlling an electronic device provided on a surface of the sheet supporting layer of the decorative sheet opposite to the second adhesive layer,

the contact operation control device and the noncontact operation control device can assign control of operations according to the content of use of a user.

12. A method of manufacturing a decorative sheet, comprising:

a step of sequentially arranging a first adhesive layer and a film layer on the front surface side of a material sheet having a surface roughness R1 of the front surface side larger than a surface roughness R2 of the back surface side, and sequentially arranging a second adhesive layer and a sheet supporting layer on the back surface side;

a step of sandwiching the thin film layer on the front surface side and the sheet supporting layer on the back surface side of the raw material sheet from a normal direction and simultaneously applying pressure and heat; and

and removing pressure and heat from the film layer, the first adhesive layer, the raw material sheet, the second adhesive layer, and the sheet support layer.

Technical Field

The present invention relates to a decorative sheet obtained by combining a thin film and a stone sheet as a raw material sheet, a method for producing the same, and a display device using the same.

Background

In recent years, in surface decoration methods for parts, panels, and the like in the field of exterior and interior of home appliances and vehicles, a wide design expression and a high-grade design demand have been increasing due to diversification of customer intentions and recent genuine intention/high-grade intention. Among them, there is an increasing demand for using a raw material such as stone or cork as a decorative raw material on the basis of a raw material which has been popular from the past such as natural wood or genuine leather. These decorative materials are used as a high-grade expression system having excellent design properties by providing the user with texture derived from the material, such as appearance and hand touch. The decorative raw material mentioned here is a sheet-like raw material having a thickness of 5mm or less. When these decorative materials are applied to home electric appliances, vehicle interior, and the like, a protective layer is usually formed on the surface of the material in order to ensure the reliability as a product.

Patent document 1 discloses a wood decorative molded article having a top coat film layer formed on the upper portion of a veneer (japanese text: raised panel). The structure thereof is shown in FIG. 5.

The wood decorative molded article 100 of fig. 5 is composed of a top coat film layer 101, a veneer 102, and a base material 103. A single plate 102 as a raw material sheet is formed to be thin to a thickness of about 2mm and thus has a certain degree of transparency, and a base material 103 having transparency is joined and integrated to the back surface of the single plate 102 by injection molding.

Disclosure of Invention

The decorative sheet of the present invention comprises:

a raw material sheet having a surface roughness R1 of the surface side larger than a surface roughness R2 of the back surface side;

a first adhesive layer provided on a surface side of the raw material sheet;

a film layer provided on a front surface side of the raw material sheet with the first adhesive layer interposed therebetween;

a second adhesive layer provided on the back surface side of the raw material sheet; and

a sheet supporting layer provided on the back surface side of the raw material sheet with the second adhesive layer interposed therebetween,

the film layer is a multilayer structure comprising at least one hard coat layer and one UV barrier layer,

the material sheet, the first adhesive layer, the film layer, the second adhesive layer, and the sheet supporting layer are integrated into one sheet, and an air layer is present at an interface between the first adhesive layer and a valley of the uneven shape of the surface of the material sheet.

The method for manufacturing the decorative sheet of the present invention comprises:

a step of sequentially arranging a first adhesive layer and a film layer on the front surface side of a material sheet having a surface roughness R1 of the front surface side larger than a surface roughness R2 of the back surface side, and sequentially arranging a second adhesive layer and a sheet supporting layer on the back surface side;

a step of sandwiching the thin film layer on the front surface side and the sheet supporting layer on the back surface side of the raw material sheet from a normal direction and applying pressure and heat at the same time; and

and removing pressure and heat from the film layer, the first adhesive layer, the raw material sheet, the second adhesive layer, and the sheet supporting layer.

Drawings

Fig. 1A is a plan view of the decorative sheet according to embodiment 1.

FIG. 1B is a cross-sectional view A-A of the decorative sheet of FIG. 1A.

Fig. 1C is a cross-sectional view of the method for manufacturing a decorative sheet according to embodiment 1 before the thermocompression bonding step.

Fig. 1D is a cross-sectional view of the thermal compression bonding step in the method for manufacturing a decorative sheet according to embodiment 1.

Fig. 1E is a sectional view of the method for manufacturing a decorative sheet according to embodiment 1 immediately after the completion of the thermocompression bonding step.

Fig. 2A is a plan view of the decorative sheet according to embodiment 2.

Fig. 2B is a B-B sectional view of a formed article including the decorative sheet of fig. 2B.

Fig. 3A is a plan view of the decorative sheet with a light source according to embodiment 3.

FIG. 3B is a cross-sectional view C-C of the decorative sheet with a light source of FIG. 3A.

Fig. 3C is a plan view of another example of the decorative sheet with a light source.

FIG. 3D is a cross-sectional view C1-C1 of the decorative sheet of FIG. 3C.

Fig. 4A is a top view of the display device according to embodiment 4.

Fig. 4B is a D-D sectional view of the display device of fig. 4A.

Fig. 4C is a plan view of another example of the display device.

FIG. 4D is a cross-sectional view D1-D1 of the display device of FIG. 4C.

Fig. 5 is a sectional view of the wood decorative molded article of patent document 1.

Description of the reference numerals

1 Stone sheet

2 film layer

3 first adhesive layer

4 second adhesive layer

5 sheet support layer

6 third adhesive layer

7 enhancement layer

8 printing layer

9 base material

10 fourth adhesive layer

11 light source

12a, 12b, 12c light source

13 substrate

14 light diffusion layer

15 hidden layer

16 arbitrary characters, marks, patterns and patterns

17a, 17b, 17c conceal light transmission portions in the layer 15

18a, 18b, 18c, indicia on the film layer 2 indicating the display area

19 recess groove

20a, 20b, 20c annular recesses provided on the surface of the thin film layer 2

25 operation control device

31 decorative sheet

41 molded article

50. 50a decorative sheet with light source

60. 60a display device

Detailed Description

In the above-described conventional example, the top-coat film layer 101 having a thick film is formed on the surface of the veneer 102 used as the decorative raw material sheet by top-coat coating. Therefore, the veneer 102 is perceived as a glossy and deep appearance, and therefore, is perceived as a feeling of incongruity compared with the material itself. Further, the surface roughness of the single sheet 102 is buried in the top coat film layer 101. Therefore, it is difficult to maintain the original texture of the single plate 102 such as the appearance and the tactile sensation.

Further, since the surface protective layer is formed by coating, the uneven shape of the surface of the material is completely filled. That is, the surface protective layer is formed in close contact with the uneven shape of the surface of the material without providing a gap between the surface of the material and the surface protective layer. Therefore, when repeated expansion and contraction occurs due to a difference in thermal expansion of the material caused by repeated changes in ambient temperature, there is a possibility that defects such as cracks may occur in the top coating film layer and the decorative material during use over the years. In particular, in an environment where the temperature changes drastically, such as in-vehicle interior, the influence of the thermal expansion difference is significant.

The present invention has been made to solve these two conventional problems, and an object of the present invention is to provide a decorative sheet that can reduce defects due to aging, such as cracking of a decorative material or a surface protective layer, caused by a difference in thermal expansion between different materials, while maintaining the texture of the material.

The decorative sheet according to the first aspect includes:

a raw material sheet satisfying a relation of inequality R1> R2 indicating that the surface roughness R1 of the front surface side is larger than the surface roughness R2 of the back surface side;

a first adhesive layer provided on a surface side of the raw material sheet;

a multilayer-structured film layer provided on the surface side of the raw material sheet with the first adhesive layer interposed therebetween and including at least one hard coat layer and one UV blocking layer;

a second adhesive layer provided on the back surface side of the raw material sheet; and

a sheet supporting layer provided on the back surface side of the raw material sheet with the second adhesive layer interposed therebetween,

each of the layers is integrated into one sheet, and an air layer is present at an interface between the first adhesive layer and a valley of the uneven shape on the surface side of the raw material sheet.

According to the above configuration, since the thin film layer has a multilayer structure including at least one hard coat layer and one UV blocking layer, the thin film layer can be made thin and can maintain sufficient strength. Therefore, the film layer provided on the front surface side of the raw material sheet can protect the raw material sheet, and the texture of the raw material sheet can be maintained. Further, the air layer existing at the interface between the first adhesive layer and the valleys of the uneven shape on the surface side of the raw material sheet can absorb the volume difference caused by the difference in thermal expansion between the raw material sheet and the thin film layer against the temperature change of the decorative sheet. This can suppress the occurrence of defects due to aging.

According to a second aspect of the decorative sheet of the first aspect, in the first aspect, the surface roughness RA of the surface of the film layer opposite to the first adhesive layer, the surface roughness RB of the surface side of the raw material sheet, and the surface roughness RC of the surface of the sheet supporting layer on the second adhesive layer side may satisfy the relationship RB > RA > RC.

According to the above configuration, the surface roughness RB of the raw material sheet positioned in the middle of the decorative sheet is made larger than the surface roughness RA of the surface side of the thin film layer and the surface roughness RC of the second adhesive layer side of the sheet supporting layer, whereby the stress applied to the entire sheet from the transverse direction can be efficiently absorbed. Further, regarding the relationship between the surface roughness RA and RC, by making the surface roughness RA of the film layer touched by a user with a hand larger than RC, the user can feel a tactile sensation from the material when touching with a hand.

The decorative sheet according to the third aspect, in the first or second aspect, the sheet supporting layer may include at least 1 selected from a polymer film and a nonwoven fabric containing polyethylene terephthalate, an acrylic polymer (アクリル), polycarbonate, or the like as a main component.

The decorative sheet according to a fourth aspect may further include a reinforcing layer made of a resin and provided on the sheet supporting layer on the side opposite to the second adhesive layer in any one of the first to third aspects.

According to a fifth aspect of the decorative sheet of any one of the first to fourth aspects, an uneven shape different from that of the surface side of the material sheet when viewed from the normal direction may be disposed on the surface of the film layer opposite to the first adhesive layer.

According to the above configuration, the appearance such as the gloss of the surface of the film layer opposite to the first adhesive layer touched by the user can be changed. Further, the tactile sensation from the raw material sheet can be emphasized, and the combination shows different tactile sensations.

The decorative sheet according to a sixth aspect may further include a light source that irradiates light from a back side toward a front side of the decorative sheet in any one of the first to fifth aspects.

A decorative sheet according to a seventh aspect of the present invention is the decorative sheet according to any one of the first to sixth aspects, wherein:

a printing layer at least comprising more than 1 hiding layer and light diffusion layer;

a base material for providing the printing layer; and

and a fourth adhesive layer for adhering the base material to the sheet supporting layer.

The decorative sheet according to an eighth aspect of the present invention is the decorative sheet according to any one of the first to seventh aspects, wherein the material sheet may be at least one material sheet selected from the group consisting of stone, wood, cork, cloth, and leather.

A display device according to a ninth aspect includes:

the decorative sheet according to any one of the first to eighth aspects; and

and a contact operation control device provided on a surface of the decorative sheet opposite to the second adhesive layer, for a user to control an electronic device.

A display device according to a tenth aspect includes:

the decorative sheet according to any one of the first to eighth aspects; and

and a noncontact operation control device provided on the sheet supporting layer of the decorative sheet on the side opposite to the second adhesive layer and configured to control an electronic device in accordance with the movement of a user's palm or arm.

The display device according to an eleventh aspect includes:

the decorative sheet according to any one of the first to eighth aspects; and

a contact type operation control device and a noncontact type operation control device provided on a surface of the decorative sheet opposite to the second adhesive layer for controlling an electronic device,

the contact operation control device and the noncontact operation control device can assign operation control according to the content of use of the user.

A method of manufacturing a decorative sheet according to a twelfth aspect includes:

a step of sequentially arranging a first adhesive layer and a film layer on the front surface side of a raw material sheet and a second adhesive layer and a sheet supporting layer on the back surface side of the raw material sheet, the first adhesive layer and the film layer satisfying the relation of inequality R1> R2 indicating that the surface roughness R1 on the front surface side is larger than the surface roughness R2 on the back surface side;

a step of sandwiching the thin film layer on the front surface side and the sheet supporting layer on the back surface side of the raw material sheet from a normal direction and applying pressure and heat at the same time; and

and removing pressure and heat from the film layer, the first adhesive layer, the raw material sheet, the second adhesive layer, and the sheet supporting layer.

According to the above configuration, the uneven shape on the surface side of the material sheet is deformed so that the interval between the uneven shapes becomes wider in the thermocompression bonding step, and the first adhesive layer penetrates into the deformed uneven shape. When the deformed uneven shape is restored to the original shape after the thermocompression bonding step, the first adhesive layer in a molten state due to the residual heat is immersed so as to be drawn into the deformed uneven shape. This improves the conformability of the thin film layer formed on the upper portion to the uneven shape on the surface side of the material sheet.

In this way, by forming the protective layer of the thin film so as to follow the uneven shape of the surface of the decorative material, the feeling of depth in appearance can be prevented, and the original touch of the material can be maintained. This makes it possible to protect the surface of the decorative material without impairing the texture of the decorative material.

Further, in the thermoplastic adhesive layer for bonding the film layer and the decorative material, when the thermoplastic adhesive layer is immersed in a molten state into the concave and convex portions of the decorative material, an air layer remains at the interface between the thermoplastic adhesive layer and the surface of the decorative material. This air layer thus plays a role of a cushion material for relaxing stress caused by a difference in thermal expansion between the respective materials. Therefore, defects such as cracks caused by repeated expansion and contraction of the raw material and the thin film protective layer over time can be reduced.

Hereinafter, a decorative sheet, a method of manufacturing the same, and a display device using the same according to embodiments will be described with reference to the drawings. In the drawings, substantially the same components are denoted by the same reference numerals.

(embodiment mode 1)

Fig. 1A is a plan view of the decorative sheet according to embodiment 1 in which a stone sheet is used as a decorative material sheet. FIG. 1B is a cross-sectional view A-A of FIG. 1A.

The decorative sheet 31 is configured as a decorative sheet 31 having the stone sheet 1 as a component. Specifically, the decorative sheet 31 uses the natural stone sheet 1 as a raw material sheet. A first adhesive layer 3 is provided on the front surface side of the stone sheet 1, and a thin film layer 2 is provided on the outermost surface through the first adhesive layer 3. Further, a second adhesive layer 4 is provided on the back surface side of the stone sheet 1, and a sheet supporting layer 5 is provided through the second adhesive layer 4. The stone material sheet 1 as the original material sheet satisfies the relation of inequality R1> R2 in which the surface roughness R1 of the front surface side is larger than the surface roughness R2 of the back surface side. The film layer 2 has a multilayer structure including at least one hard coat layer and one UV blocking layer. Further, the layers are integrated into one sheet, and an air layer E is present at the interface between the first adhesive layer 3 and the valleys of the uneven shape on the surface of the stone sheet 1.

According to the configuration of the decorative sheet 31 described in embodiment 1, the stone sheet 1 can be protected by the thin film layer 2 provided on the surface side of the stone sheet 1, the texture from the raw material can be maintained, and the air layer E, which is present at the interface between the first adhesive layer 3 and the valleys of the uneven shape on the surface side of the stone sheet 1, functions as a cushion material, and can alleviate the stress in the decorative raw material and the thin film layer due to the difference in thermal expansion between different raw materials, and reduce the occurrence of cracks and the like during the aged change.

Hereinafter, the members constituting the decorative sheet will be described.

< Stone sheet >

The maximum thickness of the stone piece 1 is 5mm or less, and the minimum thickness is 0.1mm or more. If the thickness is more than 5mm, the flexibility of the stone sheet 1 is lost, and thus it is difficult to perform processing such as bending, and if it is less than 0.1mm, the stone sheet 1 itself is difficult to manufacture.

The stone slab 1 has the feature of at least partially transmitting light by transmitting it from the back side. The front surface side has irregularities from the material, while the back surface side has a relatively smooth surface with few irregularities. Specifically, when the surface roughness Rz of the front surface side is denoted as R1 and the surface roughness Rz of the back surface side is denoted as R2, the relationships of R1> R2, 5 μm < R1 < 20000 μm, and 1 μm < R2 < 200 μm are satisfied. R2 is "maximum height roughness". Specifically, the peak highest in the cross-sectional curve within the range of the standard length thereof is expressed in numerical values by the Japanese Industrial Standard (JIS), and the obtained value is expressed in micrometers. If R1> R2 is not satisfied within this range, the difference in the size of the surface irregularities becomes large, and the ability of the thin film layer 2 to follow the surface of the stone sheet 1 is reduced. In this way, selecting a stone piece having a surface roughness on the front side larger than that on the back side increases the surface area, which is advantageous in that heat is easily released from the front side to the outside in an environment exposed to high temperature such as a vehicle interior. On the other hand, by providing the rear surface side with a relatively smooth surface, when the decorative sheet 31 is repeatedly thermally expanded due to a temperature difference, the effect of alleviating the difference in expansion and contraction of the uneven shape on the front surface side by the smooth surface on the rear surface side is exerted. This can reduce the influence of the difference in expansion and contraction on the other layers formed on the back surface of the decorative sheet 31.

< thin film layer >

The film layer 2 has a multilayer structure including at least one hard coat layer and one UV blocking layer. The hard coat layer and the UV blocking layer each have a thickness in the range of 1 to 20 [ mu ] m. Since the thin film layer 2 has transparency with a total film thickness of 3 μm to 50 μm, the distance from the stone chip 1 is reduced, and the feeling of depth in the case of applying a general top coat with a thick film is not felt, but the original texture of the stone chip 1 can be felt. The hard coat layer and the UV blocking layer may contain additives such as a filler and a flame retardant. Further, when the thin film layer 2 is formed, arbitrary unevenness can be given to the shape of the outermost surface by using the mold abrasive grains (gold シボ), the plate with abrasive grains, the film with abrasive grains, the filler, and the like, and the appearance, touch, gloss, and the like of the surface of the decorative sheet 31 can be freely changed. Further, when insert molding is performed using the thin film layer 2 on a material such as a stone sheet 1 which is hard and from which a stone is partially peeled in a mold, the decorative sheet 31 can be directly insert molded without using a separate protective material for preventing the mold surface from being stained or damaged.

The surface of the film layer 2 opposite to the first adhesive layer 3 may be provided with an uneven shape different from that of the surface side of the stone sheet 1 as a raw material sheet when viewed from the normal direction. This makes it possible to change the appearance such as the gloss of the surface of the film layer 2 opposite to the first adhesive layer 3 that is touched by the user. Further, the tactile sensation from the raw material can be emphasized, and the combination can exhibit different tactile sensations.

< first adhesive layer, second adhesive layer >

The first adhesive layer 3 and the second adhesive layer 4 are made of transparent thermoplastic components such as olefin and polyolefin. The thickness thereof may be arbitrarily set, and particularly, the thickness of the first adhesive layer 3 is preferably 1 μm or more and 30 μm or less in order to improve the followability of the thin film layer 2 to the surface of the stone sheet 1.

< sheet supporting layer >

The sheet supporting layer 5 is made of a polymer film such as polyethylene terephthalate, an acrylic polymer, or polycarbonate, or a nonwoven fabric. Therefore, even when the uneven shape on the surface of the stone sheet 1 is deformed by applying pressure in the thermocompression bonding step in the method for producing a decorative sheet, the deformation is buffered by the sheet supporting layer 5, and the uneven shape is less likely to be broken. The material, thickness, and the like of the sheet supporting layer 5 can be selected according to the application.

< relationship with respect to surface roughness >

The surface roughness RA of the surface of the film layer 2 opposite to the first adhesive layer 3, the surface roughness RB of the surface side of the stone sheet 1, and the surface roughness RC of the surface of the sheet support layer 5 on the second adhesive layer 4 side satisfy the relationship RB > RA > RC.

By making the surface roughness RB of the surface side of the stone material sheet 1 positioned at the middle inside the decorative sheet 31 larger than the surface roughness RA of the surface side of the thin film layer 2 and the surface roughness RC of the surface of the sheet support layer 5 on the second adhesive layer 4 side, it is possible to efficiently absorb the stress applied to the entire sheet from the lateral direction. In the relationship between the surface roughness RA and RC, the surface roughness RA of the film layer 2 touched by the user with the hand is made larger than RC, so that the user can feel a tactile sensation from the material when touching with the hand.

< method for producing decorative sheet >

Fig. 1C, 1D, and 1E are cross-sectional views showing cross-sections of the decorative sheet 31 according to embodiment 1 before, during, and immediately after the completion of the thermocompression bonding step.

(1) A stone sheet 1 is prepared as a raw material sheet, and a first adhesive layer 3 and a film layer 2 are disposed on the surface side. Further, a second adhesive layer 4 and a sheet supporting layer 5 are disposed on the back surface side of the stone sheet 1. As shown in fig. 1C, the first adhesive layer 3 and the thin film layer 2 are in a state of contacting with each other only without following the surface shape of the stone material piece 1 before the thermocompression bonding step.

(2) In the thermocompression bonding step of fig. 1D, the thin film layer 2 on the front surface side and the sheet supporting layer 5 on the back surface side of the stone sheet 1 are sandwiched from the normal direction by a thermocompression bonding apparatus N such as a vacuum thermocompressor or a thermocompressor, and pressure and heat are simultaneously applied. Thereby, the interval between the convex portions S1 and S2 on the front surface side of the stone sheet 1 is deformed in the direction in which the pressure of the thermocompression bonding device N spreads. Fig. 1D shows a state in which the first adhesive layer 3 having been thermally melted is immersed in the recess h. At this time, air remains in the recess h by the penetration of the first adhesive layer 3, thereby forming an air layer E.

(3) Immediately after the thermal compression bonding process of fig. 1E is completed, the pressure and heat generated by the thermal compression bonding apparatus N are removed. Thereby, the pressure applied to the convex portions S1, S2 on the front surface side of the stone sheet 1 by the thermocompression bonding apparatus N is removed. Thus, when the original shape of fig. 1C is restored, the first adhesive layer 3 in a molten state due to the residual heat during thermocompression bonding enters so as to be further pushed into the inside of the concave portion h. As a result, the thin-film layer 2 formed on the upper portion of the first adhesive layer 3 also enters the inside of the concave portion h so as to be drawn in, and as a result, the thin-film layer 2 has improved conformability to the uneven shape of the surface of the stone sheet 1. The air layer E remains as it is.

According to these configurations, the following ability of the thin film layer 2 to the surface of the stone sheet 1 is improved, and the unevenness of the stone sheet 1 and the unevenness of the thin film layer 2 are close to each other in a similar shape, so that the appearance depth feeling of the decorative sheet 31 can be prevented, and the original feeling of the material can be maintained. Therefore, the surface-protected decoration can be realized without impairing the texture of the decorative material. Further, the air layer E remaining inside the valley bottom of the uneven shape of the decorative material plays a role of a cushion material for relaxing stress caused by a difference in thermal expansion between different materials, and plays a role of reducing defects such as crack generation caused by repeated expansion and contraction of the decorative material and the thin film layer due to aging. In other words, when the thermal expansion of the thin film layer 2 is larger than that of the stone material sheet 1, when the decorative sheet 31 reaches a high temperature from a low temperature, the thin film layer 2 expands to deform the surface of the decorative sheet 31, but the air layer E reduces the deformation.

(embodiment mode 2)

Fig. 2A shows a decorative sheet 31 according to embodiment 2 in which the stone sheet 1 is used as a decorative material. Fig. 2B is a B-B sectional view of a molded article 41 including the decorative sheet 31 of fig. 2A.

Note that, the same reference numerals are given to the components that achieve the same functions as those in embodiment 1, and the description is given. Embodiment 2 is configured as follows: in addition to the configuration of embodiment 1, the molded article 41 of the third adhesive layer 6 and the reinforcing layer 7 is provided on the back surface side of the sheet supporting layer 5 constituting the decorative sheet 31.

The decorative sheet 31 may be attached as a sheet itself like wallpaper, or may be integrated with the reinforcing layer 7 by vacuum pressure forming, insert forming, or the like.

The third adhesive layer 6 has a thickness of 1 μm or more and 50 μm or less, and may be formed of any of a thermoplastic adhesive or a thermosetting adhesive of a coating type, a sheet shape, or the like.

The reinforcing layer 7 is formed of resin by insert molding, but any resin plate, glass plate, or the like having the same strength may be used. Examples of the resin usable as the resin material of the reinforcing layer 7 include general-purpose molding resins such as PMMA resin, ABS resin, PS resin, and PC resin. In addition, the resin composition can be applied to resins requiring high-temperature molding such as resins for optical use and super engineering resins.

In addition, although fig. 2B shows a cross-sectional view in which the third adhesive layer 6 is formed, when the sheet support layer 5 is insert-molded using a nonwoven fabric, the molding resin enters the gap between the nonwoven fabric to generate an anchor effect, so that the third adhesive layer 6 does not need to be formed, and the decorative sheet 31 can be used as it is as an insert-molding member.

(embodiment mode 3)

Fig. 3A is a plan view showing a decorative sheet 50 with a light source according to embodiment 3 in which a stone sheet is used as a decorative material. Fig. 3B is a C-C sectional view of the decorative sheet with a light source 50 of fig. 3A. Note that the same reference numerals are used to describe components that perform the same functions as those in embodiments 1 and 2. In embodiment 3, the light source 11 is provided on the back surface side of the stone piece 1 in addition to embodiments 1 to 2.

In fig. 3A and 3B, the light source 11 is provided on the back surface of the decorative sheet 31. In the decorative sheet with a light source 50, light emitted from the light source 11 passes through the sheet supporting layer 5, the second adhesive layer 4, the stone sheet 1, the first adhesive layer 3, and the film layer 2, respectively. As a result, the thickness variation of the stone piece 1 becomes different in light transmittance, and the observer can visually confirm the light design of the decorative piece 31 showing the shade. The same configuration may be provided on the back surface of the molded article 41 of embodiment 2. In the case of the molded article 41, similarly, the light emitted from the light source 11 is transmitted through the reinforcing layer 7, the third adhesive layer 6, the sheet supporting layer 5, the second adhesive layer 4, the stone sheet 1, the first adhesive layer 3, and the film layer 2, respectively, as the light transmittances of the third adhesive layer 6 and the reinforcing layer 7, and the optical design of the molded article 41 can be expressed.

According to these configurations, for example, when the decorative sheet is used for an in-vehicle interior member, the light source 11 can be turned on to illuminate the interior space of the vehicle.

Fig. 3C is a plan view of another example of the decorative sheet with a light source 50 a. FIG. 3D is a cross-sectional view C1-C1 of the lighted trim piece 50a of FIG. 3C.

The decorative sheet with a light source 50a of this other example is characterized in that a printed layer 8, a base material 9 for forming the printed layer 8, and a fourth adhesive layer 10 for bonding the base material 9 to the sheet supporting layer 5 are formed in this order between the second adhesive layer 4 and the sheet supporting layer 5. Further, the light sources 12a, 12b, and 12c and the substrate 13 are provided on the back surface side of the decorative sheet 31. In the same manner as described above, the same configuration may be provided on the back side of the molded article 41.

< printing layer >

The printing layer 8 is formed by a configuration in which at least 1 or more light diffusion layers 14 and a concealing layer 15 are printed on the back side thereof.

< light diffusion layer >

The light diffusion layer 14 has an effect of uniformly diffusing light emitted from the light sources 12a, 12b, and 12c and transmitting the light. Thus, even when the light sources 12a, 12b, and 12c use point-emitting light sources such as LEDs, the transmitted light can be uniformly emitted regardless of the distance from the light sources, and the light can be transmitted through the surface of the decorative sheet.

< hidden layer >

The concealing layer 15 has light transmitting portions 17a, 17b, and 17c having arbitrary shapes 16 of characters, marks, and patterns in part, and is formed of a light-shielding material which does not transmit light except for the light transmitting portions 17a, 17b, and 17 c. When light is emitted from the light sources 12a, 12b, and 12c, only the light transmitting portions 17a, 17b, and 17c transmit the light, and the shape 16 is displayed on the surface of the decorative sheet 31. When the light source 12a is turned on, the light passes through the sheet supporting layer 5, the fourth adhesive layer 10, the base material 9, the light transmitting portion 17a of the concealing layer 15, the light diffusing layer 14, the second adhesive layer 4, the stone sheet 1, the first adhesive layer 3, and the film layer 2, and the mark 18a indicating the display region is displayed on the surface of the film layer 2. The shape of the light-transmitting portion 17a is shown as the shape of the mark 18 a. When the light source 12b is turned on, the light passes through the sheet supporting layer 5, the fourth adhesive layer 10, the base material 9, the light transmitting portion 17b of the concealing layer 15, the light diffusing layer 14, the second adhesive layer 4, the stone sheet 1, the first adhesive layer 3, and the film layer 2, and a mark 18b indicating a display region is displayed on the surface of the film layer 2. The shape of the light-transmitting portion 17b is shown as the shape of the mark 18 b. When the light source 12c is turned on, the light passes through the sheet supporting layer 5, the fourth adhesive layer 10, the base material 9, the light transmitting portion 17c of the concealing layer 15, the light diffusing layer 14, the second adhesive layer 4, the stone sheet 1, the first adhesive layer 3, and the film layer 2, and a mark 18c indicating a display region is displayed on the surface of the film layer 2. The shape of the light-transmitting portion 17c is shown as the shape of the mark 18 c.

< shape >

The shape, size, number, display position, and other design of the shape 16 can be arbitrarily set by the user. The display is not limited to the mark, and may be in a display form such as a character, 7-segment number, or the like, and may be set arbitrarily by the user.

< substrate >

The substrate 9 is formed of a general polymer film such as a polyethylene terephthalate film, an acrylic polymer film, or a polycarbonate film. The thickness may be set arbitrarily as long as it is 200 μm or less, and is preferably 100 μm or less in consideration of the warpage of the decorative sheet 31.

< fourth adhesive layer >

The fourth adhesive layer 10 is composed of a transparent thermoplastic component such as olefin or polyolefin, as in the first adhesive layer 3 and the second adhesive layer 4, and the thickness thereof can be set arbitrarily.

< light Source >

The light sources 12a, 12b, and 12c are configured by incorporating light emitting diode chips of blue, red, and green (three primary colors of light) into a single package, and thus can easily control color change and the like, thereby expressing full color. In addition, other light sources than LEDs may be used as the backlight. In the case of the molded article 41, the light sources 12a, 12b, and 12c and the substrate 13 may be embedded between the reinforcing layer 7 and the third adhesive layer 6 or inside the reinforcing layer 7, and may be designed according to the use situation of the user. Further, the sheet supporting layer 5 may be provided with a half mirror film or the like instead of the polymer film or the nonwoven fabric, so that the transmittance of light emitted from the light source can be adjusted.

According to these configurations, by combining the texture of the decorative material and the design of the light, a decorative sheet or a molded article having more excellent design can be provided to the user.

(embodiment mode 4)

Fig. 4A is a plan view showing a display device 60 according to embodiment 4 in which a stone sheet is used as a decorative material. Fig. 4B is a D-D sectional view of the display device 60 of fig. 4A. Fig. 4C is a plan view of another example of the display device 60 a. FIG. 4D is a cross-sectional view D1-D1 of the display device 60a of FIG. 4C. In fig. 4D, the uneven shapes of the stone sheet 1, the thin film layer 2, and the first adhesive layer 3 are omitted. In the drawings, the same reference numerals are given to the components that achieve the same functions as those in embodiments 1 to 3, and the description is given.

Embodiment 4 is configured as follows: in addition to embodiments 1 to 3, a display device is provided in which a contact type or non-contact type operation control device 25 is provided on the back surface side of the decorative sheet 31. The same configuration may be provided on the back surface of the molded article 41.

With these configurations, the electronic apparatus can be controlled by detecting an input operation by a finger motion or a gesture motion of a user sliding on the operation panel of the display device. For example, the brightness of the information display device, the volume setting, the output volume setting of the audio device, the temperature setting of the air conditioner, and the like can be increased/decreased. Further, by combining the display using the optical design described in embodiment 3 with the operation control device 25, a user interface having more excellent design can be provided.

When the noncontact operation control device 25 of fig. 4A and 4B is used, the operation can be controlled by reading the movement of the palm or arm of the user with a capacitance-type or distance image sensor.

On the other hand, in the operation control device 25 of fig. 4C and 4D, when a contact type operation control device of electrostatic capacitance or the like is used, an annular concave groove 19 is formed around the marks 18a, 18b, and 18C. The concave groove 19 is formed by shaping the film layer 2 formed on the surface side of the stone sheet 1 into the shape of annular concave portions 20a, 20b, and 20c from the top by using a press or the like. The properties of the thin film layer 2 and the stone sheet 1 are the same as those of embodiment 1. When a user touches an operation input portion for displaying on the front surface side of the thin film layer 2 with a finger, at least the following electrode pattern along the operation input portion is required: an electrode pattern is formed so that the coordinates when the user's finger approaches can be detected. Further, the depth of the concave groove 19 from the outermost surface SF of the decorative sheet 31 is preferably 1mm to 20mm, and the width W of the concave groove 19 is preferably 3mm to 30mm, for the concave groove 19, and if the depth is in this range, the user can freely design. In embodiment 4, the diameter D of the concave groove 19 is 40mm, the width W of the concave groove 19 is 8mm, and the depth of the concave groove 19 is 2 mm.

In the present embodiment, the concave groove 19 is designed to be annular, but by using an arc-shaped or linear concave groove having an arbitrary length, not only the input of the rotational operation but also the linear operation of the slide type can be realized. Specifically, the depth from the outermost surface of the display device is 1mm to 20mm, and the width of the concave groove is 3mm to 30mm, similarly to the above.

By providing the concave groove 19 in this manner, operability of the finger of the user in a contact state to a desired position can be improved. The touch detection type input device is not limited in its type of detection method as long as it can detect a touch of a finger on the touch panel, such as a capacitance type or a pressure-sensitive type.

In embodiments 1 to 4, a stone sheet is used as the decorative raw material sheet, but the decorative raw material sheet is not limited to a stone sheet as long as the raw material sheet satisfies the relationship of inequality R1> R2 with respect to the surface roughness R1 on the front surface side and the surface roughness R2 on the back surface side of the stone sheet. In other words, instead of the stone sheet, any raw material such as wood, cork, cloth, leather, or the like may be used as the raw material sheet.

The present application includes a combination of any of the various embodiments and/or examples described above as appropriate, and effects of the various embodiments and/or examples can be exhibited.

According to the configuration of the decorative sheet of the present invention, the thin film layer provided on the surface side of the raw material sheet can protect the raw material sheet, and the texture of the raw material sheet can be maintained, and the air layer present at the interface between the first adhesive layer and the valleys of the uneven shape on the surface side of the raw material sheet can play a role as a cushion material, and the air layer can alleviate stress in the decorative material and the thin film layer due to a difference in thermal expansion between different raw materials, thereby reducing the occurrence of cracks and the like during the aged change.

In the method for producing a decorative sheet according to the present invention, the thin film layer having a multilayer structure is formed so as to follow the uneven shape of the surface of the raw material sheet by using the thermocompression bonding step. Thus, the surface protective layer can be formed into a thin film without impairing the appearance and touch of the decorative material as the material sheet. Therefore, the original texture of the decorative material can be remarkably improved as compared with a top-coated protective layer which is strong in gloss and depth and emphasizes the appearance of a plastic material.

Industrial applicability

The decorative sheet of the present invention contributes to high functionality and high design in fields requiring decoration, such as exterior trim of various home appliances and interior trim of vehicles.