JPH11309954A - Stencil paper for thermal stencil printing and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide stencil paper for thermal stencil printing and a manufacturing method thereof improving a speed of production of the stencil paper by using an ultraviolet-curing type adhesive, preventing sticking of an uncured component of the adhesive and improving an adhesion strength and the printing resistance of the stencil paper. SOLUTION: (1) Stencil paper for thermal stencil printing prepared by sticking a porous support and a thermoplastic resin film together by an adhesive. As to the adhesive, an ultraviolet-curing adhesive containing 2-benzyl-2- dimethylamino-1-(4-morpholinophenyl)-butanone-1 and an ultraviolet-curing component is used. (2) On the occasion when the stencil paper for thermal stencil printing is manufactured by interposing the adhesive between the porous support and the thermoplastic resin film and by curing this adhesive by ultraviolet irradiation, the adhesive is cured by the irradiation of ultraviolet rays having an emission wavelength of 1-450 nm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stencil sheet for heat-sensitive stencil printing and a method for producing the same, and more particularly to a stencil sheet for heat-sensitive stencil printing suitable for making a plate using a heating element of a thermal head.

[0002]

2. Description of the Related Art In general, as heat-sensitive stencil base paper,
A base paper is used in which a thin thermoplastic resin film of about several μm is adhered to the surface of a porous support such as paper with an adhesive. As the adhesive, a solvent-based or water-based adhesive is used (for example, Japanese Patent Publication Nos. 47-1188 and 47-1187). In the case of a solvent-based adhesive, a large amount of solvent is used. Therefore, there is a problem that the cost is high for the collection, the working environment is deteriorated, the obtained product is inferior in solvent resistance, and the ink used is limited. In addition, in the case of an aqueous adhesive, the amount of heat required for drying is enormous, and the heat during drying causes shrinkage of the thermoplastic resin film and dimensional change of the porous support, resulting in curling and wrinkling. Was.

In order to solve such disadvantages, use of a non-solvent type adhesive such as a thermosetting type, a room temperature curing type, a moisture curing type, and an ultraviolet ray curing type has been proposed (JP-A-61-286).
Nos. 131, 58-153697 and 62-
181374, 63-233890, etc.). However, in the case of thermosetting adhesives, the amount of heat required for curing is enormous, and furthermore, during production, the thermoplastic resin film shrinks and the dimensional change of the porous support occurs, causing the problem of curling and wrinkling. there were. Further, in the case of a room temperature curing type or moisture curing type adhesive, there is a problem that the curing speed is slow, a long time is required for producing base paper, and productivity is poor. In addition, acrylate-based UV-curable adhesives are generally inhibited from curing by oxygen in the atmosphere, and uncured components are generated. When uncured components are pierced with a thermal head for thermal stencil printing, the surface of the heating element of the thermal head is heated. Had the problem of contaminating it.

In Japanese Patent Publication No. Hei 7-106678,
To reduce the effect of oxygen inhibition, as a photoinitiator,
2-methyl [4- (methylthio) phenyl] -2-morpholino-propanone-1 and a tertiary amine photoinitiator or a tertiary amine sensitizer, or a tertiary amine photosensitizer and thioxanthone It has been proposed to use a combination of photoinitiators. However, in the former case, the curing speed is low when irradiating ultraviolet rays from the polyester film side to cure, and the productivity cannot be improved.In the case of the latter combination, the surface curability is poor, and it is suitable for thin film curing. There was a disadvantage that there was no.

[0005]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, improves the production speed of heat-sensitive stencil base paper by using an ultraviolet-curable adhesive, and cures the uncured adhesive. A heat-sensitive stencil sheet and a method for producing the same, which can prevent the components from adhering to the heating element of the thermal head, and can improve the adhesive strength between the porous support and the thermoplastic resin film and the printing durability of the base paper. To provide.

[0006]

Means for Solving the Problems In view of the above problems, the present inventors have conducted intensive studies. As a result, a polyester film mainly used as a thermoplastic resin film has a transmittance of ultraviolet rays of 320 nm or less of 5% or less, A considerable amount of light energy is absorbed by the polyester film and the curing of the adhesive becomes insufficient, and the uncured adhesive component and the insufficiently cured adhesive component that is tacky contaminate the heat generating part of the thermal head, Focusing on causing a decrease in adhesive strength, the above-mentioned problems are solved by using a specific photopolymerization initiator having an absorption characteristic at a wavelength of 320 to 450 nm and having excellent surface curability. The present inventors have found out what can be done and have reached the present invention.

The invention claimed in the present application is as follows. (1) A heat-sensitive stencil sheet obtained by laminating a porous support and a thermoplastic resin film with an adhesive, wherein the adhesive is 2-benzyl-2-dimethylamino-1-
A heat-sensitive stencil sheet using an ultraviolet-curable adhesive containing (4-morpholinophenyl) -butanone-1 and an ultraviolet-curable compound. (2) The ultraviolet-curable compound is a monomer having at least one (meth) acryloyl group in a molecule of 20 to 100.
(1) The heat-sensitive stencil printing paper according to (1), comprising: by weight, and 0 to 80% by weight of an oligomer having two or more (meth) acryloyl groups in a molecule.

(3) The monomer having one or more (meth) acryloyl groups in the molecule is phenyloxyethyl (meth) acrylate, tricyclodecane (meth) acrylate, isobornyl (meth) acrylate, tetrahydrofurfuryl ( (Meth) acrylate, morpholine acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, neopentyl glycol di (meth)
Acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol hydroxypivalate di (meth) acrylate, caprolactone-modified neopentyl glycol hydroxypivalate di (meth) acrylate, dipentaerythritol penta (meth) acrylate, di (2) The heat sensitivity according to (2), which is at least one of pentaerythritol hexa (meth) acrylate, tris [(meth) acryloxyethyl] isocyanurate and caprolactone-modified tris [(meth) acryloxyethyl] isocyanurate. Base paper for stencil printing.

(4) The oligomer having two or more (meth) acryloyl groups in the molecule is an epoxy (meth)
(2) or (3), which is at least one of an oligomer mainly composed of acrylate and an oligomer mainly composed of urethane (meth) acrylate.
The heat-sensitive stencil sheet described in the above. (5) The adhesive according to any one of (1) to (4) is interposed between the porous support and the thermoplastic resin film, and the adhesive is cured by irradiation with ultraviolet light to obtain a heat-sensitive stencil sheet. A method for producing a heat-sensitive stencil printing base paper, wherein the adhesive is cured by irradiation with ultraviolet light having an emission wavelength of 320 to 450 nm. (6) The method for producing a heat-sensitive stencil sheet according to (5), wherein the ultraviolet irradiation is performed by a lamp having a continuous emission wavelength between 320 and 450 nm.

[0010]

In general, when an ultraviolet-curable adhesive is used when producing a heat-sensitive stencil sheet, the adhesive layer is in contact with the atmosphere because one adherend is a porous support. The thickness of the adhesive applied is very thin, 0.1 to 5μ, so the dissolved oxygen concentration in the adhesive coating becomes very high, and the other material, polyester film, is 320nm or less generated by a high-pressure mercury lamp or the like. Since only 5% or less of the short-wavelength ultraviolet light is transmitted, when a photopolymerization initiator sensitive to such a short-wavelength ultraviolet light is used, the effective energy for curing the adhesive is reduced, and rapid curing is achieved. And curing inhibition is likely to occur.

On the other hand, in the present invention, 2-methyl [4- (methylthio) phenyl] -2 which is a conventional photoinitiator is used.
-The maximum absorption wavelength of morpholino-propanone-1 (λma
2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 (λmax = 325n) having a maximum absorption wavelength on the longer wavelength side than x = 305 nm)
Since m) is used, effective energy for curing the adhesive is increased, the curing speed can be improved, and excellent thin film curability can be obtained. Therefore, the amount of the uncured adhesive component is reduced, the amount of deposits on the heating element can be reduced, and the adhesive strength and printing durability can be improved. In addition, 320 to 450 nm irradiated from an ultraviolet irradiation device such as a metal halide lamp or an electrodeless D bulb manufactured by FUSION.
By using an ultraviolet ray having a continuous emission spectrum, energy not absorbed by the polyester film can be effectively used.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The thermoplastic resin film used in the present invention includes, for example, polyester film, polycarbonate film, polypropylene film, polyvinyl chloride-vinylidene chloride copolymer film, and the like. A polyester film is generally used from the viewpoint of image quality. The thickness of the film is preferably 10 μm or less, more preferably 1 to 6 μm.
In addition, a biaxially stretched film is usually used as the film, and the stretch ratio in both the longitudinal direction and the transverse direction is 150 to 40.
0% is preferably used.

As the material of the porous support used in the present invention, synthetic fibers such as polyester fiber, vinylon fiber and nylon fiber, and natural fibers such as manila hemp, mulberry, mitsumata and pulp are used. More than one kind can be mixed and used. The weight of the porous support is preferably from 6 to 15 g / m ² , more preferably from 8 to 15 g / m ^2.
13 g / m ² . Furthermore, its thickness is 10-60 μm
And more preferably 15 to 55 μm.

In the present invention, the adhesive between the thermoplastic resin film and the porous support comprises 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 and an ultraviolet curable compound. An ultraviolet curable adhesive containing the same is used. 2-benzyl-2- used in the present invention
Dimethylamino-1- (4-morpholinophenyl) -butanone-1 is a photopolymerization initiator having a maximum absorption wavelength at 325 nm, is less susceptible to oxygen inhibition, has excellent thin-film surface curability, and has a polyester film to inhibit permeation. Since it is not easily affected by heat, it exhibits excellent curing characteristics when producing heat-sensitive stencil printing base paper. The amount of the photopolymerization initiator used is from 0.1 to 15% by weight, preferably from 0.5 to 10% by weight, based on the total amount of the ultraviolet curable adhesive from the viewpoints of curability and storage stability. Is preferred.

2-benzyl-2-dimethylamino-1-
32 other than (4-morpholinophenyl) -butanone-1
Examples of the photoinitiator having a large light absorption property at 0 nm or more include Michler's ketone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, isopropylthioxanthone, and bis (2,6-dimethoxybenzoyl) -2 , 4,
4-trimethylpentylphosphine oxide, 2,
4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl)
-Phenylphosphine oxide and the like are known,
When these photoinitiators are used, they are susceptible to oxygen inhibition under the conditions of thin film coating of 2 μm or less required for production of heat-sensitive stencil printing paper, and the surface curability is reduced. Is within the range not adversely affected by the above-mentioned 2-benzyl-2-dimethylamino-1- (4-
Morpholinophenyl) -butanone-1.

A photopolymerization initiation aid such as amines, for example, 4,4'-bis (diethylamino) benzophenone,
-Diethylaminoethyl benzoate, 2-dimethylaminoethyl benzoate, dimethylaminoacetophenone, ethyl p-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate and the like can also be used in combination.
The amount of the photopolymerization initiation aid used is usually 0 to 15% by weight, preferably 0 to 10% by weight, based on the total amount of the adhesive.

As the ultraviolet-curable compound used in the present invention, a monomer having one or more (meth) acryloyl groups in the molecule is preferable, and when higher adhesive strength and durability (prevention of deterioration) are required. Is preferably used by mixing the monomer with an oligomer having two or more (meth) acryloyl groups in the molecule. The weight ratio of the monomer and oligomer (monomer / oligomer) is 20
~ 100/0 ~ 80, more preferably 20 ~
95/5 to 80, more preferably 50 to 95/5 to 5
0.

The monomer having one or more (meth) acryloyl groups in the molecule includes one (meth) acrylic group in the molecule.
Monofunctional acrylic monomers having an acryloyl group and polyfunctional acrylic monomers having two or more (meth) acryloyl groups in a molecule can be exemplified. Examples of the monofunctional acrylic monomer include, for example, an acrylic monomer having a ring structure such as an aliphatic ring, an aromatic ring, and a heterocyclic ring,
Examples thereof include aliphatic acrylates having a hydroxyl group.

Examples of the acrylic monomer having a ring structure such as an aliphatic ring, an aromatic ring, and a heterocyclic ring include, for example, tricyclodecane (meth) acrylate, dicyclopentenyl (meth) acrylate, isobornyl (meth) acrylate, and adamantyl ( (Meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, morpholine acrylate, phenylglycidyl (meth)
Acrylate and the like. Further, these alkylene oxide modified products can also be used. In particular, modified alkylene oxides having 2 to 3 carbon atoms, such as dicyclopentenyloxyethyl (meth) acrylate and phenyloxyethyl (meth) acrylate, are preferred.

As the aliphatic acrylate having a hydroxyl group, for example, an acrylate in which a hydroxyl group is bonded to an aliphatic group having 2 to 9 carbon atoms is preferable, and a hydroxyl group is more preferably bonded to an aliphatic group having 2 to 4 carbon atoms. Acrylate compound. A substituent such as a phenoxy group may be bonded to the aliphatic acrylate. Examples of the acrylate compound include 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 2-hydroxy-3-phenoxypropyl (meth).
Acrylate and the like.

Of the above-mentioned monofunctional acrylic monomers, particularly preferred from the viewpoint of maintaining viscosity, wet heat resistance and adhesiveness, for example, phenyloxyethyl (meth) acrylate, tricyclodecane (meth) acrylate, isobornyl ( (Meth) acrylate, tetrahydrofurfuryl (meth) acrylate, morpholine acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth)
Acrylate and the like.

The polyfunctional acrylic monomers are classified into bifunctional acrylic monomers and trifunctional or higher functional acrylic monomers. Examples of the bifunctional acrylic monomer include an acrylate compound of an aliphatic diol having 4 to 9 carbon atoms, an alkylene oxide type acrylic monomer, and an acrylic monomer having a ring structure. Examples of the aliphatic diol acrylate compound having 4 to 9 carbon atoms include neopentyl glycol di (meth) acrylate and 1,6-hexanediol di (meth) acrylate. The acrylate compound of the aliphatic diol may be modified with an aliphatic ester or an alkylene oxide. Examples of the aliphatic ester-modified acrylate compound include neopentyl glycol hydroxypivalate di (meth) acrylate and caprolactone-modified neopentyl glycol hydroxypivalate di (meth) acrylate.

Examples of the alkylene oxide-modified acrylate compound include diethylene oxide-modified neopentyl glycol di (meth) acrylate, dipropylene oxide-modified neopentyl glycol di (meth) acrylate, and diethylene oxide-modified 1,6-hexanediol di (meth) acrylate. Acrylate, dipropylene oxide-modified 1,6-hexanediol di (meth) acrylate and the like can be mentioned. Examples of the alkylene oxide type acrylic monomer include neopentyl glycol-modified trimethylolpropane di (meth) acrylate,
Examples include polyethylene glycol di (meth) acrylate and polypropylene glycol di (meth) acrylate. As the acrylic monomer having a ring structure,
For example, tricyclodecane dimethylol di (meth) acrylate, dicyclopentanyl di (meth) acrylate and the like can be mentioned.

Examples of the trifunctional or higher functional acrylic monomer include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, aliphatic modified dipentaerythritol penta (meth) acrylate having 2 to 5 carbon atoms, carbon 2-5 aliphatic modified dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, caprolactone modified dipentaerythritol hexa (meth) acrylate, pentaerythritol tetra ( (Meth) acrylate, tris [(meth) acryloxyethyl] isocyanurate, caprolactone-modified tris [(meth) acryloxyethyl] isocyanurate, ditrimethylolpropane Tiger (meth) acrylate.

Among the above-mentioned polyfunctional acrylic monomers, those which are particularly preferable from the viewpoint of maintaining viscosity, wet heat resistance and adhesiveness include bifunctional acrylic monomers such as neopentyl glycol di (meth) acrylate and 1,6-
Aliphatic diol acrylate compounds having 4 to 9 carbon atoms such as hexanediol di (meth) acrylate, neopentyl glycol hydroxypivalate di (meth) acrylate, caprolactone-modified neopentyl glycol hydroxypivalate di (meth) acrylate, etc. Aliphatic ester-modified aliphatic diol acrylates are exemplified. Examples of trifunctional or higher acrylic monomers include dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and tris [(meth) acryloxyethyl] isocyanate. Nurate,
Caprolactone-modified tris [(meth) acryloxyethyl] isocyanurate.

The amount of these monomers used is preferably 5 to 90% by weight based on the total amount of the ultraviolet-curable adhesive. These monomers may be used singly or in combination of two or more at an arbitrary ratio. However, from the viewpoint of viscosity, the use of a monofunctional acrylic monomer or a bifunctional acrylic monomer is preferred, and the use of a trifunctional acrylic monomer is preferred. It is preferable to use the above-mentioned acrylic monomers as needed.

The oligomer having two or more (meth) acryloyl groups in the molecule is preferably used by mixing with the above monomer when higher adhesive strength and durability (prevention of deterioration) are required as described above. . The oligomer is preferably one that dissolves in the above-mentioned monomer. Examples of such an oligomer include oligomers containing epoxy (meth) acrylate, polyester (meth) acrylate, or urethane acrylate as a main component. The oligomer having epoxy (meth) acrylate as a main component is obtained by a reaction between an epoxy resin and (meth) acrylic acid. Examples of the epoxy resin include bisphenol type epoxy resins such as bisphenol A type epoxy resin and bisphenol F type epoxy resin, and novolak type epoxy resins. Examples of the bisphenol A type epoxy resin include Epicoat 828 (trade name, manufactured by Yuka Shell Epoxy Co., Ltd .; the same applies hereinafter), Epicoat 1
001, Epicoat 1004 and the like. Examples of the bisphenol F type epoxy resin include Epicoat 40
01P, Epicoat 4002P, Epicoat 4003P
And the like. Further, examples of the novolak type epoxy resin include Epicoat 152 and Epicoat 154.

The oligomer having a polyester (meth) acrylate as a main component is obtained by a reaction between a polyester polyol and (meth) acrylic acid. The polyester polyol is obtained by a reaction between a polyhydric alcohol and a polybasic acid. Examples of the polyhydric alcohol include neopentyl glycol, ethylene glycol, propylene glycol, 1,6-hexanediol, trimethylolpropane, pentaerythritol, tricyclodecane dimethylol, bis- [hydroxymethyl] -cyclohexane, and the like. Examples of the polybasic acid include succinic acid, phthalic acid, hexahydrophthalic anhydride, terephthalic acid, adipic acid, azelaic acid, tetrahydrophthalic anhydride and the like.

Oligomers containing urethane (meth) acrylate as a main component include those obtained by the reaction of a polyol with an organic polyisocyanate and a hydroxy (meth) acrylate compound, and the use of an organic polyisocyanate without using a polyol. Those obtained by a two-way reaction with a hydroxy (meth) acrylate compound are exemplified. As the polyol, polypropylene glycol, polyether polyol such as polytetramethylene glycol, a polyester polyol obtained by reacting the polyhydric alcohol with the polybasic acid, a reaction between the polyhydric alcohol, the polybasic acid and ε-caprolactone And a polycarbonate polyol (for example, a polycarbonate polyol obtained by a reaction between 1,6-hexanediol and diphenyl carbonate).
As the organic polyisocyanate, for example, isophorone diisocyanate, hexamethylene diisocyanate, tolylene diisocyanate, xylene diisocyanate,
Diphenylmethane-4,4'-diisocyanate, dicyclopentanyl diisocyanate, and the like. Those obtained by the three reactions or those obtained by the two reactions may be used alone or in combination.

Of these oligomers, particularly preferred are oligomers containing epoxy (meth) acrylate or urethane (meth) acrylate as a main component in terms of maintaining viscosity, heat and moisture resistance and adhesiveness. These oligomers may be used alone or in combination of two or more kinds at an arbitrary ratio. In the ultraviolet-curable adhesive used in the present invention, for example, a polyester-based, polycarbonate-based, polyacryl-based, polyurethane-based, polyvinyl-based resin, or the like may be used as a high molecular polymer, if necessary. If necessary, silane coupling agents, polymerization inhibitors, leveling agents, surface lubricants, defoamers, light stabilizers, antioxidants, antistatic agents,
Additives such as fillers can also be used in combination.

Examples of the silane coupling agent include an alkyl type, an amine type, a (meth) acrylate type, an isocyanate type, an epoxy type and a thiol type. The amount of the silane coupling agent used is usually about 0 to 10% by weight based on the total amount of the adhesive. Examples of the polymerization inhibitor include methoquinone and methylhydroquinone.
The amount of the polymerization inhibitor used is usually about 0 to 1% by weight based on the total amount of the adhesive. Examples of the leveling agent, the surface lubricant, and the defoaming agent include organic polymer, silicon, and fluorine. Examples of the antioxidant include hindered amines, hindered phenols, and high molecular phenols. The amounts of these leveling agents, surface lubricants, defoamers, and antioxidants used are generally about 0 to 5% by weight based on the total amount of the adhesive. Antistatic agents include quaternary ammonium, polyether,
Conductive powder and the like. The amount of the antistatic agent is usually about 0 to 30% by weight based on the total amount of the adhesive. It is preferable that the amount of these additives used is appropriately selected within the above range according to the purpose.

The UV-curable adhesive used in the present invention has a remarkable temperature dependence of the viscosity, and the viscosity drops sharply by slightly increasing the coating temperature of the adhesive. Is obtained. In addition, after the adhesive is applied to the porous support in a thin film, the viscosity of the adhesive rises sharply only by slightly lowering the temperature of the adhesive. Stencil paper with excellent resolution and image quality can be obtained, and the initial holding force that suppresses the peeling of the porous film and the thermoplastic film generated during lamination occurs, and the laminating workability is improved. Become. The UV-curable adhesive has a viscosity of 50
300 mPa · s or less at 25 ° C and 1200 mP at 25 ° C
It is preferably at least a · s, and it is preferable to mix the above-mentioned components so as to obtain such a viscosity in view of coating properties on the porous support, initial holding power, and impregnation prevention properties.

The base paper for heat-sensitive stencil printing according to the present invention is characterized in that the above-mentioned UV-curable adhesive is used for a thermoplastic resin film and / or
Alternatively, it can be obtained by applying the composition to a porous support, bringing them into close contact with each other, and then irradiating ultraviolet rays to cure and adhere the composition. A multi-roll coating method is preferable as a method of applying the ultraviolet curable adhesive, but a blade coating method, a gravure coating method, a knife coating method, a reverse roll coating method, a spray coating method, an offset gravure coating method, a kiss coating method, etc. You may. The thickness of the coating film of the ultraviolet curing multi-adhesive is 0.0
A range of 1 to 2.0 μm is preferred.

There is no particular limitation on the light source for curing the ultraviolet-curable adhesive, for example, a pressure or high pressure mercury lamp,
Metal halide lamps, xenon lamps, electrodeless discharge lamps, carbon arc lamps, etc. can be used.
It is preferable to use a metal halide lamp or an electrodeless discharge lamp D bulb having a continuous wavelength between 20 and 450 nm because the curing speed can be improved. Although the heat-sensitive stencil sheet of the present invention has excellent plate-making properties, when forming a perforation by heating the thermoplastic resin film by a thermal head or other methods, depending on the conditions, the thermal head may be a thermoplastic resin film. When a perforation is formed by exposure through a positive original film, the thermoplastic resin film may adhere to the positive original film.

In order to solve such a problem, it is preferable to form an anti-adhesion layer having heat-fusibility and non-adhesion on the thermoplastic resin film. In order to obtain heat melting property, for example, polytetrafluoroethylene, polychlorotrifluoroethylene, tetrafluoroethylene, hexafluoroethylene copolymer, fluorine resin such as polyvinylidene fluoride, silicone resin, epoxy resin, melamine resin, phenol Resin, polyimide resin,
Polyvinyl acetal resin, polyvinyl butyral resin, polyoxyethylene terephthalate, polyethylene oxide resin, and the like are used. Further, in order to obtain the slipperiness (non-adhesiveness) of the anti-adhesion layer, a surfactant such as stearic acid, palmitic acid, Fatty acid metal salts such as metal salts such as lithium, potassium, sodium, calcium, barium, and aluminum such as lauric acid and oleic acid; phosphate ester surfactants; polyoxyethylene surfactants; mono- and dialkyl phosphoric acids Esters, tri (polyoxyethylene alkyl ether) phosphates, etc.
Alternatively, a silicone oil or the like is used.

The anti-adhesion layer preferably contains about 10 to 200 parts by weight of a surfactant or the like per 100 parts by weight of the resin, and these materials are dissolved or dispersed in an organic solvent or water to prepare a coating liquid. What is necessary is just to form, apply | coat and apply this to the surface of a thermoplastic resin film layer by arbitrary methods. If the thickness of the anti-adhesion layer is too large, the heat sensitivity is lowered and the formation of perforations becomes insufficient, so that the anti-adhesion layer is preferably thin, for example, about 0.001 to 1 μm. The timing of forming the anti-adhesion layer is not particularly limited, and it may be after forming the heat-sensitive stencil printing base paper, during formation, or may be formed on a raw thermoplastic resin film.

[0037]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. . As the adhesive, various adhesives I to VI manufactured by mixing the components and the amounts shown in Table 1 were used.
In addition, lamps i to iv shown in Table 2 were used as ultraviolet irradiation devices.

[0038]

[Table 1]

A: bisphenol A glycidyl ether diacrylate oligomer B: urethane acrylate oligomer C: 2-hydroxy-3-phenoxypropyl acrylate D: tetrahydrofurfuryl acrylate E: 2-benzyl-2-dimethylamino-1- (4- Morpholinophenyl) -butanone-1 F: 2-methyl [4- (methylthio) phenyl] -2-
Morpholino-propanone-1 G: bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (initiator having light absorption characteristics at 320 to 450 nm) H: 4,4'-bis (diethylamino) benzophenone I: 4 -Diethylaminoethyl benzoate

[0040]

[Table 2] * 1: An electrodeless discharge lamp having a continuous emission wavelength between 320 and 450 nm, similar to a metal halide lamp. * 2: An electrodeless discharge lamp with the same waveform as a high-pressure mercury lamp and no continuous emission wavelength.

Examples 1 to 6 and Comparative Examples 1 and 2 The respective UV-curable adhesives I to VI shown in Table 3 were heated to 40 ° C. on a surface of a polyester film having a thickness of 2 μm using a roll coater. Then, after coating so as to have a coating thickness of 0.8 μm, weighing 12 g as a porous support
/ M ² polyester fiber 30% by weight and Japanese paper fiber 7
A mixed fiber paper containing 0% by weight was pressed. Immediately thereafter, ultraviolet rays were irradiated from the polyester film side with each of the ultraviolet irradiation devices i to iv shown in Table 3 to cure the adhesive, and the film and the support were bonded together. At this time, the irradiation distance from the lamp was 120 mm, and the traveling speed was 40 m / m.
was in. Next, a release agent composed of a silicone resin was applied to the film surface of the base paper so as to have a thickness of 0.2 μm using a roll coater to obtain a heat-sensitive stencil printing base paper.

The obtained heat-sensitive stencil sheet was converted into a digital stencil printing machine (RISOGRAPHIC TR-15, manufactured by Riso Kagaku Kogyo KK).
Plate-making printing was performed using 3). The characteristics at this time were examined as follows, and the results are shown in Table 3. The evaluation of the contamination of the thermal head (TPH) was repeated up to 150 plates by continuous plate making of a solid portion, and thereafter, changes in the surface state of the heating element and changes in the print density of the printed matter were observed, and evaluated according to the following criteria. A: The surface of the TPH element was very clean, and there was no deposit, and a clear image having no influence on printing was obtained. ：: Some deposits were observed on the surface of the TPH element,
A clear image without affecting printing was obtained. X: A considerable deposit was observed on the surface of the TPH element, and white streaks caused by the deposit were observed in the printed matter.

The curability was evaluated by peeling the film portion of the heat-sensitive stencil sheet immediately after irradiation with ultraviolet light from the porous support, observing the cured state of the adhesive adhering to the film by hand, and curing and tacking. The presence or absence of adhesiveness was observed and evaluated according to the following criteria. ◎: Completely cured, no tack was observed. ：: Hardened but tacky. ×: Not cured at all.

The peel strength (lamination adhesive strength) of the heat-sensitive stencil printing paper was 50 (CD direction) × 150 (MD direction) of the base paper on which kraft tape was stuck on both sides for reinforcement.
The test piece was cut into a test piece having a size of 5 mm and the film and the support were peeled at a peel angle of 180 ° and a peel speed of 300 m / min.
It measured by the magnitude of the peel strength per 0 mm. The water resistance and the solvent resistance were measured by measuring the peel strength after immersing the test piece having the above peel strength in pure water and a petroleum-based high-boiling solvent at 40 ° C. for 24 hours, and measuring the water resistance and the solvent resistance, respectively. .

[0045]

[Table 3]

From Table 3, it can be seen that the heat-sensitive stencil printing paper of the present invention (Examples 1 to 7) has little TPH contamination, has excellent adhesive curability, and has excellent peel strength, water resistance and solvent resistance. It is shown to be excellent. In contrast, the base paper of Comparative Example 1 uses a compound having a wavelength of λ 302 nm as a photopolymerization initiator, and thus the curing speed of the adhesive is low,
An uncured component of the adhesive was present, TPH contamination occurred, and peel strength, water resistance, and solvent resistance were poor. Further, in the base paper of Comparative Example 2, although a compound having an absorption property at 320 nm or more was used as a photopolymerization initiator, curing was inhibited due to the influence of oxygen, and curing was not performed. could not.

[0047]

According to the heat-sensitive stencil printing paper of the present invention,
Since a specific photopolymerization initiator having an absorption property at a wavelength of 320 to 450 nm and excellent in surface curability is used as an ultraviolet-curable adhesive, the adhesive comes into contact with oxygen in the atmosphere in a thin film. In the state where, even when the adhesive is cured by irradiation of ultraviolet rays through a polyester film that hardly transmits ultraviolet rays having a short wavelength of 320 nm or less,
It has excellent curing properties and can be completely cured with little tack even at high production line speeds.
Accordingly, there is no adhesion of deposits on the surface of the thermal head heating element, stable thermosensitive plate making properties can be obtained, and clear printed matter can be obtained. In addition, there is no need to clean the thermal head, and the plate-making workability is excellent. In addition, since the thermoplastic resin film and the porous support can be firmly cured and adhered by the ultraviolet curable adhesive, the laminate adhesive strength is high and the printing durability is excellent.

Claims (6)

[Claims] 1. A heat-sensitive stencil printing paper in which a porous support and a thermoplastic resin film are bonded together with an adhesive, wherein the adhesive is 2-benzyl-2-dimethylamino-1- (4-morpholino). Phenyl) -butanone-1
A heat-sensitive stencil sheet using an ultraviolet-curable adhesive containing a compound and an ultraviolet-curable compound. 2. The method according to claim 1, wherein the ultraviolet-curable compound has one molecule per molecule.
Monomer 20 having at least two (meth) acryloyl groups
2. The heat-sensitive stencil printing paper according to claim 1, wherein the base paper comprises from 100 to 100% by weight and from 0 to 80% by weight of an oligomer having two or more (meth) acryloyl groups in a molecule. 3. The monomer having one or more (meth) acryloyl groups in the molecule is phenyloxyethyl (meth) acrylate, tricyclodecane (meth) acrylate, isobornyl (meth) acrylate, tetrahydrofurfuryl (meth) ) Acrylate, morpholine acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth)
Acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol hydroxypivalate di (meth) acrylate, caprolactone-modified neopentyl glycol hydroxypivalate di (meth) acrylate, di Pentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tris [(meth) acryloxyethyl] isocyanurate and caprolactone-modified tris [(meth)
Acryloxyethyl] isocyanurate
The heat-sensitive stencil sheet according to claim 2, which is a seed. 4. The oligomer having two or more (meth) acryloyl groups in the molecule is at least one of an oligomer mainly composed of epoxy (meth) acrylate and an oligomer mainly composed of urethane (meth) acrylate. The heat-sensitive stencil printing paper according to claim 2 or 3, wherein: 5. The heat-sensitive stencil printing base paper is obtained by interposing the adhesive according to claim 1 between a porous support and a thermoplastic resin film, and curing the adhesive by ultraviolet irradiation. A method for producing a heat-sensitive stencil printing base paper, wherein the adhesive is cured by irradiation with ultraviolet light having an emission wavelength of 1 to 450 nm. 6. The method for producing a stencil sheet for heat-sensitive stencil printing according to claim 5, wherein the ultraviolet irradiation is performed by a lamp having a continuous emission wavelength between 320 and 450 nm.