阅读说明：本技术 热敏孔版原纸用支承体和热敏孔版原纸 (Support for thermosensitive porous base paper and thermosensitive porous base paper ) 是由 荒井正胜 松浦宏和 山本光保 于 2020-08-13 设计创作，主要内容包括：本发明为热敏孔版原纸用支承体和热敏孔版原纸,该热敏孔版原纸用支承体包含麻浆和合成纤维,横向的JAPAN TAPPI No.71中规定的拉伸断裂伸长率相对于纵向的JAPAN TAPPI No.71中规定的拉伸断裂伸长率之比为1.0～1.4。(The present invention relates to a support for a heat-sensitive stencil sheet, and a heat-sensitive stencil sheet, wherein the support for a heat-sensitive stencil sheet comprises hemp pulp and synthetic fibers, and the ratio of the tensile elongation at break specified in the horizontal JAPAN TAPPI No.71 to the tensile elongation at break specified in the vertical JAPAN TAPPI No.71 is 1.0 to 1.4.)

1. A support for heat-sensitive mimeograph stencil paper, which comprises a hemp pulp and a synthetic fiber,

the ratio of the tensile elongation at break specified in JAPAN TAPPI No.71 in the transverse direction to the tensile elongation at break specified in JAPAN TAPPI No.71 in the longitudinal direction is 1.00 to 1.40.

2. The support for a thermosensitive porous base paper according to claim 1, wherein the compression work measured in a state where the support for a thermosensitive porous base paper is stacked by 10 sheets is 1.200 to 1.460 gf-cm/cm²。

3. The support for heat-sensitive mimeograph stencil as claimed in claim 1 or 2, wherein the ratio of the tensile strength specified in the transverse direction JAPAN TAPPI No.71 to the tensile strength specified in the longitudinal direction JAPAN TAPPI No.71 is 0.20 to 0.40.

4. The support for a heat-sensitive mimeograph stencil as claimed in any one of claims 1 to 3, wherein the mass ratio of the hemp pulp to the synthetic fiber (hemp pulp: synthetic fiber) is 30: 70-45: 55.

5. the support for heat-sensitive stencil printing paper according to any of claims 1 to 4, wherein the ratio of the tensile elongation at break specified in JAPAN TAPPI No.71 in the transverse direction to the tensile elongation at break specified in JAPAN TAPPI No.71 in the longitudinal direction is 1.20 to 1.40.

6. The support for heat-sensitive stencil printing paper according to any of claims 1 to 5, wherein the elongation at break in tension specified in JAPAN TAPPI No.71 in the machine direction is 4.5% or less.

7. A heat-sensitive mimeograph stencil comprising the support for a heat-sensitive mimeograph stencil as claimed in any one of claims 1 to 6 and a thermoplastic resin film.

Technical Field

Embodiments of the present invention relate to a support for a thermosensitive stencil sheet and a thermosensitive stencil sheet.

Background

A heat-sensitive stencil sheet (hereinafter, also referred to as a "stencil sheet") generally includes a porous support and a thermoplastic resin film laminated on the porous support.

In general, a thermal head (TPH) is used for plate making of a stencil sheet, and when unevenness is present on the surface of the stencil sheet, the following may occur: during plate making, the adhesion between TPH and the film is deteriorated, and a portion which is easily perforated and a portion which is difficult to perforate are generated. Therefore, perforation such as that of an original document may not be possible, and a good print image may not be obtained using the stencil sheet.

Patent document 1 discloses a base paper for thermal stencil printing having a specific tensile strength elongation characteristic.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 8-58262

Disclosure of Invention

Problems to be solved by the invention

An object of an embodiment of the present invention is to provide a support for a thermal stencil sheet that can obtain a printed image with good image quality even when the thermal stencil sheet is stored and reused, and a thermal stencil sheet using the same.

Means for solving the problems

Embodiments of the present invention relate to a support for heat-sensitive stencil paper, which comprises hemp pulp and synthetic fibers, and has a ratio of tensile elongation at break specified in the transverse direction JAPAN TAPPI No.71 to tensile elongation at break specified in the longitudinal direction JAPAN TAPPI No.71 of 1.00 to 1.40.

Another embodiment of the present invention relates to a heat-sensitive mimeograph stencil including the support for a heat-sensitive mimeograph stencil and a thermoplastic resin film.

ADVANTAGEOUS EFFECTS OF INVENTION

The embodiment of the present invention can provide a support for a thermosensitive stencil sheet that can obtain a printed image with good image quality even when the thermosensitive stencil sheet is stored and then used, and a thermosensitive stencil sheet using the same.

Drawings

Fig. 1 is a diagram illustrating compression work.

Detailed Description

The embodiments of the present invention will be described in detail below, but the present invention is not limited to these embodiments, and various modifications and changes can be applied thereto.

< support for thermal mimeograph stencil >

The support for a heat-sensitive stencil sheet of the present embodiment comprises a pulp and a synthetic fiber, and the ratio of the tensile elongation at break specified in JAPAN TAPPI No.71 in the transverse direction to the tensile elongation at break specified in JAPAN TAPPI No.71 in the longitudinal direction is 1.00 to 1.40. In the present specification, the longitudinal direction is defined as a vertical direction, and a direction perpendicular to the longitudinal direction is defined as a horizontal direction.

If the surface of the stencil paper, particularly the film, has irregularities, when a Thermal Print Head (TPH) is used to make a plate, the TPH and the film have poor adhesion, and a portion that is easy to perforate and a portion that is difficult to perforate are generated, and perforation like a document is not possible, and a good printed image may not be obtained.

Even if the surface smoothness of the stencil paper in the sheet state is excellent, the surface smoothness may deteriorate with time when the stencil paper is wound in a roll shape, and the surface smoothness may not be maintained as in the sheet state. Therefore, when a plate making and printing are performed using a stencil sheet wound in a roll shape after storage, a good print image may not be obtained. The reason for this is presumed to be: the porous base paper wound in a roll shape is pressed by the fibers of the support compressed by pressure in the laminating step and/or the rolling step of winding the porous base paper in a roll shape, and as a result, the film is pressed, and as a result, unevenness occurs in the film, and the surface smoothness is lowered. In particular, the winding pressure is high in the vicinity of the core of the roll, and the stress generated by the recovery of the thickness concentrates toward the core, so that this phenomenon becomes remarkable and tends to deteriorate with the passage of time. On the other hand, in order to avoid this, if the winding pressure of the roll is reduced, the handling property as a product is reduced.

When the support for a thermosensitive stencil sheet is used, a thermosensitive stencil sheet can be obtained which can suppress the deterioration of the surface smoothness of the thermosensitive stencil sheet during storage over time and can form a printed image with good image quality even when used after storage.

The support for a heat-sensitive mimeograph stencil (hereinafter sometimes referred to as "support") preferably contains hemp pulp and synthetic fibers. The support is preferably a porous support.

The support body is preferably elongated. The support preferably uses the longitudinal direction (longitudinal direction) of the strip as the conveyance direction.

As the form of the support, for example, a sheet paper, a nonwoven fabric, a woven fabric, a screen yarn, or the like can be used.

The hemp pulp is natural fiber and can be obtained by cooking and pulping the raw materials. The hemp pulp has the characteristics of high strength and difficult stretching.

Examples of the raw material of the hemp pulp include manila hemp, kenaf (kenaf), sisal hemp, ecuador hemp, jute and the like. The support may be used with only 1 kind of hemp pulp or two or more kinds in combination.

The support body contains, in addition to hemp pulp, natural fibers such as dime, daphne, etc. The support may use only 1 kind of natural fiber other than these pulps, or two or more kinds in combination.

As the synthetic fibers, for example, polyester, polyamide, polyphenylene sulfide, polyacrylonitrile, polypropylene, polyethylene, or a copolymer thereof can be used. These synthetic fibers may be used alone or in combination of two or more.

Among these, from the viewpoint of strength and/or water resistance, polyester and polyacrylonitrile are preferable, and for example, it is also preferable to use polyester and polyacrylonitrile in combination. Examples of the polyester include polyethylene terephthalate, a copolymer of ethylene terephthalate and ethylene isophthalate, polyethylene naphthalate, polyhexamethylene terephthalate, and a copolymer of hexamethylene terephthalate and 1, 4-cyclohexanedimethanol terephthalate. Examples of the polyester fiber generally include a polyethylene terephthalate drawn polyester fiber, an undrawn polyester fiber, and a polyester composite fiber having a polyethylene terephthalate polyester as a core component and an amorphous copolyester composed of terephthalic acid, isophthalic acid, ethylene glycol, diethylene glycol, or the like as a sheath component.

The synthetic fibers used as the support may be those having various fiber diameters according to the quality required for the base paper, and may be those having a single fiber diameter or those having two or more fiber diameters in combination. For example, coarse fibers may be blended to improve rigidity and brushing resistance, and fine fibers may be blended to improve image quality.

The average fiber diameter and the fiber length of the fibers contained in the support are not particularly limited.

The average fiber diameter of the hemp pulp is preferably 0.1 to 60 μm, more preferably 1 to 30 μm. The fiber length of the hemp pulp is preferably 0.1mm to 15 mm.

The average fiber diameter of the synthetic fibers is preferably 40 μm or less, more preferably 20 μm or less, and still more preferably 15 μm or less. The average fiber diameter of the synthetic fibers is preferably 0.1 to 40 μm, more preferably 1 to 20 μm, and still more preferably 1 to 15 μm. The synthetic fibers preferably have a fiber length of 0.1mm to 5 mm.

From the viewpoints of reducing image blur due to so-called fibers called japanese paper and obtaining a support that is difficult to recover in thickness after being compressed and flattened, the mass ratio of the content of the hemp pulp to the content of the synthetic fibers in the support (hemp pulp: synthetic fibers) is preferably 25: 75-50: 50, more preferably 30: 70-45: 55.

the support may contain flame retardants, heat stabilizers, antioxidants, ultraviolet absorbers, pigments, dyes, fatty acid esters, organic lubricating materials such as waxes, antifoaming agents such as polysiloxanes, paper strength enhancers, wet paper strength enhancers, sizing agents, and the like.

From the improvement of the use of heat-sensitive stencil paper immediately after manufactureThe tensile elongation at break (E) prescribed in JAPAN TAPPI No.71 in the transverse direction of the support is considered from the viewpoints of the image quality of the obtained printed matter and the image quality of the printed matter obtained using the stored heat-sensitive stencil paper_D2) Tensile elongation at Break (E) specified in JAPAN TAPPI No.71 with respect to the longitudinal direction_D1) Ratio of (E)_D2/E_D1) (hereinafter, it may be referred to as "E of tensile elongation at break_D2/E_D1Ratio ") is preferably 1.00 to 1.40, more preferably 1.10 to 1.40, still more preferably 1.20 to 1.40, and still more preferably 1.20 to 1.35.

If the tensile elongation at break of the support is E_D2/E_D1When the ratio is 1.40 or less, the elongation in the transverse direction with respect to the longitudinal direction does not become excessively large, and therefore, deformation is less likely to occur when the support is stretched in, for example, a laminating step of laminating the support and the thermoplastic resin film, a winding step of winding a stencil sheet into a roll, or the like. Therefore, the quality of the printed matter obtained by using the stored thermal mimeograph stencil paper can be kept good.

E tensile elongation at break of the support_D2/E_D1The ratio is preferably 1.40 or less, more preferably 1.35 or less.

If the tensile elongation at break of the support is E_D2/E_D1When the ratio is 1.00 or more, the elongation in the longitudinal direction with respect to the transverse direction does not become too large, so that deformation does not occur easily, and the image quality of a printed matter obtained by using the stored heat-sensitive mimeograph stencil paper can be maintained good.

E tensile elongation at break of the support_D2/E_D1The ratio is preferably 1.00 or more, and from the viewpoint of improving the image quality of a printed matter obtained using the heat-sensitive mimeograph stencil paper immediately after production, more preferably 1.10 or more, and even more preferably 1.20 or more.

Tensile elongation at Break (E) specified in JAPAN TAPPI No.71 of longitudinal direction of support_D1) Preferably 5.0% or less, more preferably 4.8% or less. From the viewpoint of further improving the image quality of a printed matter obtained using the stored heat-sensitive stencil paper, the tensile elongation at break (E) specified in JAPAN TAPPI No.71 in the longitudinal direction of the support body_D1) More preferably 4.5% or less.

On the other hand, the tensile elongation at break (E) specified in JAPAN TAPPI No.71 in the longitudinal direction of the support_D1) Preferably 3.8% or more, more preferably 4.0% or more.

Tensile elongation at Break (E) specified in JAPAN TAPPI No.71 of longitudinal direction of support_D1) For example, it is preferably 3.8 to 5.0%, more preferably 3.8 to 4.8%, and further preferably 4.0 to 4.5%.

Tensile elongation at Break (E) specified in JAPAN TAPPI No.71 of the support in transverse direction_D2) Preferably 6.8% or less, more preferably 6.5% or less.

Tensile elongation at Break (E) specified in JAPAN TAPPI No.71 of the support in transverse direction_D2) Preferably 4.8% or more, more preferably 5.0% or more.

Tensile elongation at Break (E) specified in JAPAN TAPPI No.71 of the support in transverse direction_D2) For example, the concentration is preferably 4.8 to 6.8%, more preferably 5.0 to 6.5%.

The compression work (hereinafter, sometimes simply referred to as "compression work") measured in a state where 10 supports are stacked is preferably 1.200 to 1.460gf cm/cm²。

The larger the value of the compression work, the more easily the support is compressed. By setting the compression work of the support body to the above range, the support body which ensures ink permeability and is less likely to be compressed can be produced. Therefore, it is easy to further improve the image quality of a printed matter obtained using the heat-sensitive mimeograph stencil paper immediately after production and the image quality of a printed matter obtained using the heat-sensitive mimeograph stencil paper after storage.

The compression work of the support is preferably 1.200gf cm/cm²More preferably 1.300gf cm/cm²The above. If the compression work of the support is 1.200gf cm/cm²As described above, the ink passage property is more favorably ensured, a favorable image density can be obtained, and the image quality of a printed matter obtained using the heat-sensitive mimeograph stencil paper immediately after production can be improved.

Improvement in compression resistance of support and in picture of printed matter obtained by using stored heat-sensitive stencil paperFrom the viewpoint of quality, the compression work of the support is preferably 1.460gf cm/cm²The following.

The compression work of the support can be measured by, for example, vol.33no.2 (1980) "which is the journal of the society of mechanics of kawa-end quarternary male fibers (fiber engineering) (the society of labor やさしい of feng いと) at the point of clothing, and by reference to" the society of mechanics of kawa-end quarternary male fibers ( engineering) ".

As a measuring device for measuring the compression work of the support, for example, a KES-G5 compression tester manufactured by Kato Tech co., ltd. or a measuring device capable of realizing the above-mentioned measuring method described in "the journal of the society of china-end and china-season male fiber mechanics (fiber engineering) vol.33no.2 (1980)", which is a popular explanation of texture and clothing points, may be used. When a KES-G5 compression tester was used, the area of the pressing plate was 2.0cm in a state where 10 supports were stacked²The compression deformation rate (the descending (ascending) rate of the pressurizing plate) was 0.02 mm/sec, and the maximum compression load was 300gf/cm²Under the conditions of (1). The measurement temperature and the measurement humidity are set to 20 to 30 ℃ and 50 to 70% RH.

Fig. 1 shows a diagram for determining the compression work. In FIG. 1, the y-axis direction (vertical axis direction) represents the pressure P (gf/cm) against the support²) In the figure, the x-axis direction (horizontal axis direction) represents the thickness t (mm) per 10 support members (thickness obtained by overlapping 10 support members).

In FIG. 1, T₀Indicates that the pressure P is 50gf/cm²Thickness T obtained by superposing 10 support bodies_MThe pressure P is 300gf/cm which is the maximum compression load²The thickness of the support was 10 sheets. The compression work takes T as T₀～T_MThe integral value of P at that time, i.e., the area of the portion a in the figure, is calculated.

Tensile Strength (S) specified in JAPAN TAPPI No.71 in the transverse direction of the support_D2) Tensile Strength (S) specified in JAPAN TAPPI No.71 with respect to the machine direction_D1) Ratio of (S)_D2/S_D1) (hereinafter, it may be referred to as "S of tensile Strength_D2/S_D1Ratio ") is preferably0.10 to 0.40, preferably 0.20 to 0.40, and more preferably 0.25 to 0.40.

If S is the tensile strength of the support_D2/S_D1When the ratio is large, the fiber orientation in the transverse direction tends to increase, and when the tensile strength of the support is S_D2/S_D1When the ratio is smaller, the fiber orientation in the machine direction tends to increase. If the orientation of the fibers is uniform in any direction, the ink permeability tends to decrease. S in tensile strength of support_D2/S_D1The ratio is in the range of 0.10 to 0.40, and the fibers are oriented in the longitudinal direction more, so that S having a tensile strength in this range exists_D2/S_D1The larger the ratio becomes, the more the ink passage property tends to be improved.

S for tensile strength of support from the viewpoint of improving image quality of printed matter obtained using stored heat-sensitive mimeograph stencil paper_D2/S_D1The ratio is preferably 0.40 or less. If S is the tensile strength of the support_D2/S_D1When the ratio is 0.40 or less, the overlapping of the longitudinal fibers and the transverse fibers tends to be small, and the elasticity in the thickness direction tends to be low. Therefore, in the laminating process and the rolling process, the support is temporarily compressed, and then, even when the heat-sensitive stencil sheet is stored in a state of being wound in a roll, the support has a tensile strength S_D2/S_D1When the ratio is 0.40 or less, the deterioration of image quality due to the thickness recovery can be further reduced.

S of tensile strength of support_D2/S_D1The ratio is preferably 0.10 or more, more preferably 0.20 or more, and still more preferably 0.25 or more. If S is the tensile strength of the support_D2/S_D1When the ratio is 0.10 or more, the image quality of a printed matter obtained by using the heat-sensitive mimeograph stencil paper immediately after production can be easily improved, and therefore, the image quality of a printed matter obtained by using the heat-sensitive mimeograph stencil paper after storage can also be easily improved.

Tensile Strength (S) specified in JAPAN TAPPI No.71 of the longitudinal direction of the support_D1) Preferably 0.7kN/m or more, more preferably 0.8kN/m or more. On the other hand, the tensile strength (S) specified in JAPAN TAPPI No.71 in the longitudinal direction of the support_D1) Preferably 1.2kN/m or less, more preferably 1.1kN/m or less.

For example, the tensile strength (S) specified in JAPAN TAPPI No.71 in the longitudinal direction of the support_D1) Preferably 0.7 to 1.2kN/m or more, and more preferably 0.8 to 1.1 kN/m.

Tensile Strength (S) specified in JAPAN TAPPI No.71 in the transverse direction of the support_D2) Preferably 0.1kN/m or more. On the other hand, the tensile strength (S) specified in JAPAN TAPPI No.71 in the transverse direction of the support_D2) Preferably 0.4kN/m or less.

For example, the tensile strength (S) specified in JAPAN TAPPI No.71 in the transverse direction of the support_D2) Preferably 0.1 to 0.4 kN/m.

The air permeability resistance (hereinafter, also simply referred to as "air permeability resistance") measured by the gurley test method according to JIS P8117(2009) in a state in which 32 pieces of the support are superposed is preferably 0.47 sec/100 mL or less, and more preferably 0.45 sec/100 mL or less.

The air permeability resistance of the support is a value measured by the gurley test method according to JIS P8117(2009) with the volume of air to be measured being 100mL in a state where 32 pieces of the support are stacked.

If the air permeation resistance of the support is 0.47 seconds/100 mL or less, the ink passage property is more favorably ensured, a favorable image density can be obtained, and the image quality of a printed matter obtained using the heat-sensitive mimeograph stencil paper immediately after production can be improved.

On the other hand, the air permeability resistance of the support is preferably 0.20 sec/100 mL or more, more preferably 0.35 sec/100 mL or more, from the viewpoint of obtaining a preferable strength.

The air permeability resistance of the support is, for example, preferably 0.20 sec/100 mL-0.47 sec/100 mL, more preferably 0.35 sec/100 mL-0.45 sec/100 mL.

The basis weight of the support is preferably 20g/m²Hereinafter, more preferably 5g/m²～20g/m²More preferably 5g/m²～15g/m². Basis weight of 20g/m²When the amount of the ink is less than the above range, more excellent ink passing property and image clarity can be easily obtained, and the basis weight is 5g/m²In the above case, the preferable support is easily obtainedStrength.

The density of the support is preferably 0.05 to 1g/cm³More preferably 0.1 to 0.5g/cm³。

The thickness of the support is preferably 10 to 100. mu.m, more preferably 20 to 75 μm.

The support can be produced by a paper-making process such as a wet paper-making process. In the wet papermaking method, for example, a support can be produced by dispersing and filtering fibers, then taking the fibers out onto a wire (wire mesh), dewatering the fibers, and drying the fibers. The support is preferably manufactured using a cylinder, short-wire or fourdrinier papermaking machine.

In addition, from the viewpoint of imparting strength, brush resistance, dimensional stability, and rigidity, it is preferable to apply a water-soluble synthetic resin and/or a water-dispersible resin to a support obtained by a paper-making process such as a wet paper-making process. As the coating method, a roll coater, a gravure coater, a reverse coater, a bar coater, or the like can be used, but is not particularly limited. Examples of the water-soluble synthetic resin or water-dispersible resin include viscose, urethane resin, epoxy resin, acrylic resin, polyvinyl acetate resin, vinyl chloride resin, natural rubber such as SBR and NBR, PVA, etc., and preferably include viscose, urethane resin, or a mixture of urethane resin and another resin. The water-soluble synthetic resin may be used in the form of, for example, an aqueous solution, and the water-dispersible resin may be used in the form of, for example, an aqueous dispersion. The coating amount of the water-soluble synthetic resin and/or water-dispersible resin is preferably 0.01 to 3.0g/m in terms of solid content²。

The water-soluble synthetic resin and/or the water-dispersible resin are preferably heated after coating.

The support obtained in this manner is preferably wound into a roll.

The basis weight of the support can be controlled by adjusting the amount of the fiber material supplied to the wire during papermaking.

E tensile elongation at break of the support_D2/E_D1S of specific and tensile strength_D2/S_D1The ratio can be adjusted by, for example, adjusting the ratio of natural fibers to synthetic fibers, the degree of beatingSpeed in paper making, etc.

< Heat-sensitive stencil sheet >

The thermosensitive stencil sheet of the present embodiment includes the support (support) for thermosensitive stencil sheets and a thermoplastic resin film. When the heat-sensitive stencil sheet is used, the heat-sensitive stencil sheet can prevent the reduction of the surface smoothness over time during the storage of the heat-sensitive stencil sheet, and can form a print image with good image quality even after the heat-sensitive stencil sheet is used after the storage.

The thermosensitive stencil sheet includes a support (support) for the thermosensitive stencil sheet and a thermoplastic resin film, and the thermoplastic resin film is preferably provided on the support for the thermosensitive stencil sheet.

As the thermoplastic resin used for the thermoplastic resin film, for example, polyester, polyamide, polypropylene, polyethylene, polyvinyl chloride, polyvinylidene chloride, or a copolymer thereof can be used, and among these, polyester and polyvinylidene chloride are preferable, and polyester is more preferable, from the viewpoint of the punchability. Examples of the polyester include polyethylene terephthalate, polybutylene terephthalate, a copolymer of ethylene terephthalate and ethylene isophthalate, polyethylene naphthalate, polyhexamethylene terephthalate, and a copolymer of hexamethylene terephthalate and 1, 4-cyclohexanedimethanol terephthalate.

The thermoplastic resin film may contain organic lubricating materials such as flame retardants, heat stabilizers, antioxidants, ultraviolet absorbers, pigments, dyes, fatty acid esters, and waxes, or defoaming agents such as silicones, in amounts that do not impair the effects of the present invention. The thickness of the thermoplastic resin film is suitably determined in accordance with the sensitivity required for the base paper, and is usually 0.1 to 10 μm, preferably 0.1 to 5 μm, and more preferably 0.1 to 3 μm. When the thickness is 10 μm or less, more excellent punching properties can be easily obtained, and when the thickness is 0.1 μm or more, more excellent film forming stability of the film can be obtained.

The method for producing the heat-sensitive mimeograph stencil is not particularly limited, and it can be produced, for example, by a method including a step of bonding a support and a thermoplastic resin film. The method for bonding the support and the thermoplastic resin film is not particularly limited, and for example, an adhesive or the like can be used. Examples of the adhesive for bonding the support and the thermoplastic resin film include heat-type adhesives such as vinyl acetate-based (e.g., vinyl acetate resin), (meth) acrylic, vinyl chloride-vinyl acetate copolymer-based, polyester-based, and urethane-based adhesives; photocurable (preferably ultraviolet curable) adhesives such as (meth) acrylate, polyester (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, and polyol (meth) acrylate.

The heat-sensitive stencil sheet thus obtained is preferably wound into a roll.

Examples

The present invention will be described in detail below based on examples and comparative examples, but the present invention is not limited to these examples. In the case where nothing is specifically described, "%" is "% by mass". The amounts of the respective components in the table are also indicated by "% by mass".

< production of support for thermal mimeograph stencil >

Table 1 shows the raw materials of the supports (supports) for thermal mimeograph stencil of examples 1 to 5 and comparative examples 1 to 2 and the characteristic values of the respective supports. Each support body contained the raw materials (hemp pulp, polyester fiber, and polyacrylonitrile fiber) in the proportions shown in table 1.

For each support, using the raw materials in the proportions shown in table 1, paper making was performed using a cylinder mould machine so as to achieve specific basis weight, tensile elongation at break and tensile strength, and an impregnation coater was used at 1.3g/m²The amount (solid content) of (b) was measured, and the obtained film was wound into a roll.

Details of the raw materials described in table 1 are shown below.

Pulping the hemp: the manila hemp pulp is suitably pulped for use.

Polyester fiber: an average fiber diameter of 7 μm and a fiber length of 3mm

Polyacrylonitrile fiber: the average fiber diameter was 4 μm and the fiber length was 3mm

The tensile strength, tensile elongation at break, air permeation resistance and compression work of the support shown in table 1 were determined as follows.

(Standard State)

The standard state for testing the support was 23. + -. 1 ℃ and 50. + -. 2% RH in accordance with JIS P8111 (1998).

(tensile Strength, tensile elongation at Break)

The tensile strength and tensile elongation at break were each determined based on JAPAN TAPPI No. 71. More specifically, the tensile strength (S) in the machine direction of each support was measured based on JAPAN TAPPI No.71_D1) And the transverse tensile strength (S) of the support_D2). In the table, S of the tensile strength of the support is also shown_D2/S_D1Ratio (S)_D2/S_D1)。

Further, the tensile elongation at break (E) in the longitudinal direction of the support was measured based on JAPAN TAPPI No.71, respectively_D1) And tensile elongation at break (E) in the transverse direction of the support_D2). In the table, E of the tensile elongation at break of the support is also shown_D2/E_D1Ratio (E)_D2/E_D1)。

(degree of air resistance)

The air permeability resistance of the support was set to the following value: the air volume to be measured in a state where 32 supports were stacked was 100mL, and the value was measured according to the gurley test method of JIS P8117 (2009).

(work of compression)

The compression work of the support body was determined as follows.

As a measuring device, a KES-G5 compression tester manufactured by Kato Tech Co., Ltd was used, and in a state where 10 support members were stacked, the area of the pressure plate was 2.0cm²The compression deformation rate (pressing plate lowering rate) was 0.02 mm/sec (0.002 cm/sec), and the maximum compression load was 300gf/cm²The measurement was performed under the measurement conditions of (1), and a graph shown in FIG. 1 was produced. In FIG. 1, the y-axis direction (vertical axis direction) represents the pressure P (gf/cm) applied to the support²) In the figure, the x-axis direction (horizontal axis direction) represents 10 pieces per pieceThe thickness of the support body (the thickness obtained by overlapping 10 support bodies) T (mm). In FIG. 1, T₀Indicates that the pressure P is 50gf/cm²Thickness T obtained by superposing 10 support bodies_MThe pressure P is 300gf/cm which is the maximum compression load²The thickness of the support was 10 sheets. The compression work takes T as T₀～T_MThe integral value of P at that time, i.e., the area of the portion a in the figure, is calculated.

< production of thermal stencil paper and evaluation of image quality >

The heat-sensitive stencil papers of the examples and comparative examples were produced as follows.

On one side of a polyester film (biaxially stretched polyethylene terephthalate film, thickness: 2 μm), at a ratio of 0.45g/m²After a UV curable adhesive (urethane (meth) acrylate) was applied to the above-mentioned amount, the support prepared as described above was laminated thereon, and then an ultraviolet irradiation device (OHD-320M manufactured by ORC) was used to irradiate an ultraviolet ray from the polyester film side to cure the UV curable adhesive, and the obtained stencil sheet was wound into a roll. Thus, a stencil sheet was produced in the form of a roll having a length of 108m and a width of 320 mm.

The thermal stencil paper immediately after production and the thermal stencil paper stored for 6 months after production were subjected to plate making and printing with a plate making press ("RISOGRAPH MD 6650W", manufactured by idealistic scientific industries co., ltd.), and the image quality of the resultant printed matter was evaluated visually according to the following evaluation criteria. In table 1, the result of evaluating the image quality of the heat-sensitive stencil paper immediately after production is shown as "initial image quality". The evaluation result of the image quality of the heat-sensitive stencil paper after 6 months of storage after production is indicated as "post-storage image quality".

AA: almost no blur and white spots

A: with slight blurring and/or white spots

B: there is a slight blur and/or white spot

C: there is a lot of blurring and/or white spots

[ Table 1]

As shown in Table 1, the tensile elongation at break (E) specified in JAPAN TAPPI No.71 using the transverse direction_D2) Tensile elongation at Break (E) specified in JAPAN TAPPI No.71 with respect to the longitudinal direction_D1) Ratio of (E)_D2/E_D1) (tensile elongation at Break E_D2/E_D1Ratio) of the base material to the support in the range of 1.00 to 1.40, in examples 1 to 5, when plate making and printing were performed using the heat-sensitive stencil sheet after 6 months of storage after production, a printed image having more excellent image quality than the comparative example could be obtained.