JP2744936B2 - Base paper for heat sensitive stencil - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a heat-sensitive stencil sheet, and more particularly to a heat-sensitive stencil sheet suitable for perforation by a thermal head.

[Prior art and problems]

The heat-sensitive stencil sheet has a structure in which a thermoplastic film is bonded to a porous support. In order to obtain a stencil sheet by piercing such a stencil sheet, a method of closely contacting a document with the stencil sheet and irradiating infrared rays or a method of contacting a stencil sheet with a heat-sensitive element such as a thermal head has been used.

By the way, in the heat-sensitive stencil base paper as described above,
In order to prevent the plastic melted at the time of plate making from adhering to the original and the thermal head, an anti-fusing layer containing an anti-fusing agent such as a higher fatty acid salt or a silicone resin is provided. However, in such a conventional anti-fusing layer, electric resistance is high, static electricity is generated, and a base paper conveyance jam occurs, or at the time of printing, the base paper cannot be separated from the printing paper due to the charging of the base paper, There has been a problem that a paper winding jam occurs.

On the other hand, in order to impart antistatic properties to the anti-fusing layer, phosphate esters (JP-A-61-102294 and JP-A-61-102295) are used.
) Or a tertiary amine-type or quaternary amine-type cationic surfactant (JP-A-63-11394). Although these materials exhibit a relatively good antistatic effect, when the base paper is wound into a roll and stored, the antistatic substances used for the anti-fusion layer are removed from the anti-fusion layer. There is a problem that the migration to the side of the porous support in contact therewith results in a reduction in the fusion prevention effect and the antistatic effect.

[Problem of the Invention]

An object of the present invention is to provide a heat-sensitive stencil sheet having an anti-fusing layer having excellent antistatic properties and anti-fusing properties.

[Means for solving the problem]

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that the problems can be solved by using an anti-fusing layer containing a polymeric cationic conductive agent, thereby completing the present invention. Reached.

That is, according to the present invention, in a heat-sensitive stencil base paper in which a thermoplastic film is bonded to a porous support, a fusion prevention layer containing a polymer cationic conductive agent is provided on the surface of the film. Is provided.

The anti-fusing layer used in the present invention is characterized by containing a polymer cationic conductive agent. Such a polymeric cationic conductive agent is a conventionally known substance, and can be obtained by using a polymer having an amino group as a raw material and converting the amino group into a quaternary ammonium group, and is preferably used. And an olefinically unsaturated monomer having a quaternary ammonium group and an unsaturated monomer.

Next, a method for producing a polymer cationic conductive agent by a copolymerization method will be described in detail.

[Quaternary ammonium group-containing olefinically unsaturated monomer] As this monomer, those represented by the following general formula are preferably used.

 In the above formula, R¹Is a hydrogen or methyl group, and A is a carbon number 1-4.
Alkylene group or hydroxyalkyl having 1 to 4 carbon atoms
Group, R^Two, R^ThreeIs an alkyl group having 1 to 4 carbon atoms or 2 carbon atoms
4 to 4 hydroxyalkyl groups, R^FourIs an alkyl having 1 to 4 carbon atoms
A kill group, a hydroxyalkyl group having 2 to 4 carbon atoms or ara
Is a alkyl group. X Represents a counter anion.

 The aforementioned counter anion X As a halogen ion (CC
l^-, Br^-) And CH_ThreeOSO_Three ^-, C_TwoH_FiveOSO_Three ^-, HSO_Four ^-, H_TwoPO_Four ^-,
CH_ThreeCOO^-, CH_ThreeSO_Three ^-, NO_Two ^-And the like, but preferably,
Cl^-, Br^-, CH_ThreeOSO_Three ^-, C_TwoH_FiveOSO_Three ^-, HSO_Four ^-It is.

Specific examples of the preferable monomer used in the present invention are shown in the following table in relation to the general formula (I).

Examples of the monomer having a quaternary ammonium group include those represented by the above general formula (I), and vinylbenzyl-based monomers such as vinylbenzyltrialkylammonium salts (such as vinylbenzyltrimethylammonium chloride) and dialkyldiallyl-based monomers. Examples thereof include vinyl monomers such as dialkyldiallylammonium salts (such as dimethyldiallylammonium chloride) and quaternized vinyl monomers such as quaternized vinyl imidazoline and vinyl pyridine.

(Unsaturated monomer)

As the monomer copolymerized with the monomer having a quaternary ammonium group, various vinyl monomers are used. Such compounds include, for example, unsaturated alkyl esters such as alkyl acrylate, alkyl methacrylate, alkyl crotonate, mono (or di) alkyl itaconate, and aromatic unsaturated esters such as styrene, methyl styrene, and chlorostyrene. Monomers, acrylonitrile, unsaturated nitriles such as methacrylonitrile, ethylene,
Examples include olefins such as vinyl chloride and vinylidene chloride, and haloolefins, and vinyl esters such as vinyl acetate and vinyl basate.

Furthermore, unsaturated acids having a functional group such as unsaturated acids such as acrylic acid, methacrylic acid and crotonic acid, unsaturated acid amides, N-methylolates of unsaturated acid amides, glycidyl (meth) acrylate and hydroxyalkyl (meth) acrylate Monomers.

In the copolymer of the olefinically unsaturated monomer (A) having a quaternary ammonium group and the unsaturated monomer (B), the use ratio of the monomer (A) is 5 to 95% by weight, It is preferably 10 to 60% by weight, and the monomer (B) is 95 to 5% by weight, preferably 90 to 40% by weight. When the usage ratio of the monomer (A) is less than 5% by weight, the conductivity of the polymer becomes poor, and when it exceeds 95% by weight, the film strength of the polymer becomes weak. The number average molecular weight of the copolymer is 2,000 to 150,000,
Preferably it is 10,000-100,000. Number average molecular weight is 2,0
If it is smaller than 00, the film strength of the polymer becomes weak, and 150,
If it exceeds 000, the viscosity of the polymer solution increases, and the coating workability deteriorates. As the polymer cationic conductive agent comprising the above-mentioned copolymer, a commercially available one can be used. For example, Elecond 50B (Soken Chemical Co., Ltd.), Chemistat (6300, 8800, 5500) (Sanyo Chemical Co., Ltd.), Conductive Polymer C-280 (Calgon), Gosei Fimer C-760 (Nihon Gosei Co., Ltd.) )) And so on.

The heat-sensitive stencil sheet of the present invention is produced by laminating a thermoplastic film on a porous support, and forming an anti-fusing layer containing a polymeric cationic conductive agent on the surface of the film.

As the porous support, those generally used for this type of heat-sensitive stencil base paper can be arbitrarily used. For example, those formed into a paper shape using various fibers can be preferably used. In this case, as the fibers, synthetic fibers such as polyester fibers, vinylon fibers and nylon fibers, and natural fibers such as manila hemp, mulberry, mitsumata, and pulp can be used alone or in combination. The basis weight of the porous support is usually 6 to 14 g / m ² , preferably 7 to 14 g / m ² .
13 g / m ² and its thickness is 20 to 60 μm, preferably 25 to
50 μm.

As the thermoplastic plastic film, those conventionally used generally can be arbitrarily used. As such, for example, polyester film,
Polycarbonate film, polypropylene film,
Examples include a polyvinyl chloride film. The thickness of the film is usually 10 μm or less, preferably 1 to 5 μm.
As this film, a biaxially stretched film is preferably used.

In the present invention, the anti-fusing layer provided on the surface of the film can be formed by using only a polymeric cationic conductive agent, or can be formed by adding this to a conventional anti-fusing layer. The polymeric cationic conductive agent used in the present invention is particularly advantageously used in combination with a fusion preventing agent such as a silicone resin, a fluororesin, a phosphate ester, and a polyoxyethylene-based activator.

In order to form the anti-fusing layer of the present invention on the surface of the thermoplastic film, a polymer cationic conductive agent or a general anti-fusing agent, and a total solid content in water or an organic solvent are used.
It is dissolved so as to have a concentration of about 0.1 to ² % by weight, and is applied and dried so that the solid content adhered to the film surface is 0.001 to 0.5 g / m ² . If the solid content is too small, the conductivity and the anti-fusing property of the formed anti-fusing layer will be inferior. On the other hand, if the amount is too large, the solid content will be reduced when the plate is made by the thermal head. And the thermal head is easily stained. When the polymer cationic conductive agent is used together with the conventional anti-fusing agent, the proportion of the polymer cationic conductive agent is 0.05 to 2 parts by weight based on 1 part by weight of the anti-fusing agent.

〔Example〕

Next, the present invention will be described in more detail with reference to examples.
In addition, all the parts and% shown below are based on weight.

Example 1 Japanese paper consisting of a 1.8 μm polyester film and 11 g / m ² basis weight Manila hemp was bonded together using a chlorinated polypropylene resin (dry adhesion 1 g / m ² ) to prepare a base paper. The following coating liquid for an anti-fusing layer was applied to the film surface of the base paper and dried to form an anti-fusing layer having a solid content of 0.1 g / m ² , thereby obtaining a heat-sensitive stencil sheet.

Fluororesin (solid content 3%) (manufactured by Daikin Industries, Ltd.
33.3 parts Polymer cationic conductive agent (solid content: 50%) (Soken Chemical Co., Ltd., Elecond 50B) 0.5 part Water 66.2 parts Example 2 The following paper was applied to the film surface of the base paper shown in Example 1. The coating liquid for an anti-fusing layer was applied and dried to provide an anti-fusing layer having a solid content of 0.02 g / m ² , to obtain a heat-sensitive stencil sheet.

Silicone acrylic resin (solid content 30%) (Toa Gosei Chemical Co., Ltd., Aron XS705) 0.83 parts Polymer cationic conductive agent (solid content 3%) (Sanyo Chemical Co., Ltd., Chemistat 6300) 0.76 parts Isopropyl alcohol 68.41 parts Water 30 parts Example 3 The following coating solution for an anti-fusing layer was applied to the film surface of the base paper shown in Example 1 and dried to provide an anti-fusing layer to obtain a heat-sensitive stencil sheet.

Room temperature curing silicone acrylic resin (solid content 50%) (Toray Silicone Co., Ltd., SR2400) 2.0 parts Curing catalyst (Toray Silicone Co., Ltd., SPX · 242AC) 0.08 part Polymer cationic conductive agent (solid content 50%) (MAC, manufactured by Nippon Junyaku Co., Ltd.) 0.5 part Isopropyl alcohol 97.5 parts Comparative Examples 1 to 3 Examples 1 to 3 were repeated in the same manner as in Examples 1 to 3, except that the high molecular weight cationic conductive agent was omitted. A stencil sheet for comparison corresponding to was prepared.

Comparative Example 4 A 1% methanol solution of a cationic surfactant (Newfine Chemical Co., Ltd.) was applied to the surface of the base paper shown in Example 1.
Co., Ltd., a coating liquid for an anti-adhesion layer consisting of Elecnon OR300) was applied and dried to provide an anti-adhesion layer having a solid content of 0.2 g / m ² , thereby obtaining a stencil sheet.

Each heat-sensitive stencil sheet obtained as described above was evaluated as follows, and the results are shown in Table 2.

(1) Surface Resistance After being left in a room at 20 ° C. and 60% RH for 24 hours, the surface resistance of the anti-fusion layer was measured with a high resistance meter manufactured by Yokogawa Hewlett-Packard Company.

(2) Surface potential After standing in a room at 20 ° C. and 60% RH for 24 hours, the surface potential (V ₀ ) when −6 kv was charged on the surface of the anti-fusion layer with a paper analyzer manufactured by Kawaguchi Electric Co. for 15 seconds, The surface potential (V ₁₀ ) at the time of decay after 10 seconds was measured. (3) Workability At a line speed of 3 m / sec on a 16 dot / mm thermal head
Perform test pattern printing with applied energy of 0.11 mJ,
The piercing property, sticking property and head contamination at that time were examined. The head dirt was evaluated by observing the thermal head surface after printing 50 sheets of B4 size.

(4) Storage properties The stencil paper was wound 30 m around a paper tube, stored in a 50 ° C. constant temperature bath for 3 weeks, and then subjected to a printing test for evaluation.

：: No sticking occurred Δ: Slightly sticking ×: Sticking occurred [Effects of the Invention] The heat-sensitive stencil sheet of the present invention can perform perforation by thermal printing without fusing to a thermal head, and has excellent storage stability. Further, the product of the present invention
Since the antistatic effect is also very good, occurrence of stencil conveyance jam and occurrence of paper winding jam during printing are prevented.

Claims (1)

(57) [Claims] 1. A heat-sensitive stencil comprising a heat-sensitive stencil sheet having a thermoplastic support film bonded to a porous support, wherein a heat-sealing prevention layer containing a polymeric cationic conductive agent is provided on the surface of the heat-sensitive stencil sheet. Base paper.