JPS6233691A - Thermal stencil base paper - Google Patents

Abstract

PURPOSE:To prevent heat fusion of a film to a thermal head when a thermal stencil base paper is perforated, by a method wherein an anti-sticking layer containing any one or more of a polypropylene glycol and a polyethylene glycol/ polypropylene glycol block copolymer, or that containing a polyethylene glycol in addition to one or more of the above contents is formed on the surface of the polyester film. CONSTITUTION:A polypropylene glycol and a polyethylene glycol/polypropylene glycol block copolymer with molecular weights ranging 5,000-20,000 are preferable, because those of higher molecular weight deteriorates in its solubility to water. These substances dissolved in water is coated on the film, preferably 0.05-0.3g/m<2> in amount, together with a wetting agent including a surface-active agents of nonionic, anionic, or cationic series, and thereafter dried to form an anti-sticking layer. The polyester film of not more than 4mum thick is desirably used and a porous tissue or the like is used as a substrate therefor.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a thermal stencil paper used for digital plate making by thermal head writing perforation. For more details,
The present invention relates to a heat-sensitive stencil paper having a specific anti-stick layer provided on the surface of a polyester film.

[Prior Art] Until now, so-called heat-sensitive stencil paper, in which a thermoplastic synthetic resin film is laminated with a porous support such as porous thin paper or screen mesh through which ink can pass, has been superimposed on an original and irradiated with electromagnetic waves including infrared rays. It has been proposed to provide a release layer on the surface of the film in order to prevent the perforated film from fusing with the original, making it difficult to remove or damaging the film. ing. However, in the conventional perforation method, the direction of adhesion of the release layer (overcoat layer) material is such that the perforability of the film is not greatly affected by the amount of overcoat layer deposited, and the layer material is attached to the film and overcoat 1. It was not very important because the drilling residue caused almost no problem.

However, in the film perforation method using thermal head writing, the type of overcoat layer material and its adhesion m greatly influence the perforation performance. For example, if the amount of adhesion increases, the perforation performance decreases, or the overcoat material adheres to and accumulates on the head, causing problems that degrade the performance of the thermal head. Therefore, the solution to this problem lies in how to prevent sticking with a small amount of attached Wffi. Therefore, as a method, it has been proposed to sandwich paper between the thermal head and the heat-sensitive stencil paper and make holes (Japanese Patent Application Laid-Open No. 55-1039
However, it is impossible to perforate the film by this method with the energy (heat capacity, heat conduction, heat diffusion) of the current thermal head. Furthermore, even if holes can be made, the wI image power will be reduced and the image quality will be poor.

[Purpose] The present invention has been made in view of the above-mentioned current situation, and its purpose is to prevent a polyester film from being thermally fused to a thermal head during perforation of a heat-sensitive stencil sheet by writing with a thermal head. To improve the runnability of the base paper during drilling by eliminating secondary problems such as fuzzing, tearing, and peeling of the film that occur due to blocking and sticking phenomena, and to prevent film residue and film residue during drilling that adheres to the bone nurse head. Stick prevention layer (overcoat layer) The purpose of this layer is to prevent coating substances from adhering to improve the running performance of the thermal head.

[Structure] In order to achieve the above object, the present invention provides a so-called heat-sensitive stencil paper in which a polyester film is laminated to a porous support capable of ink mimeographing.
or a stick prevention layer comprising at least one of the polypropylene glycol and the polyethylene glycol/polypropylene glycol block copolymer of the following formula II; The object is to provide a stick prevention layer containing polyethylene glycol.

Formula ■ Formula III l(0(C112CI+20).11 In each of the above formulas, vote and n each represent an integer of 1 or more.

Although the anti-stick effect varies somewhat depending on the molecular weight of each of the above-mentioned substances from Shikiku to II-III used in the present invention, it is effective if the molecular weight of each substance is 5,000 or more. However, if the molecular weight becomes too large, the solubility in water will deteriorate, so for practical purposes it is
A range of 00 is preferred.

The anti-stick layer made of the above substance in the present invention exhibits a high anti-stick effect even with a very small amount of adhesion, and the amount of adhesion is 0.01 to 0.5 g/TrL2, preferably 0.0
5 to 0.3 (J/17L2 is sufficient. The anti-stick layer can be formed on the surface of the polyester film by dissolving the above substance in water and then coating the film and drying it.

In this case, the concentration of the substance in the aqueous solution is about 0.1 to 5% by weight, preferably about 0.5 to 3% by weight. Dry is 70
Normal drying at ~100°C for about 30 seconds is sufficient.

In addition, when applying a dilute solution to a film, repellency may occur on the coating film, so nonionic surfactants such as poloxyethylene alkylamide, poloxyethylene alkylamide, and polyester are used as wetting agents. Oxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyhydric alcohol, anionic surfactants such as alkyl sulfonates, alkylbenzene sulfonates, alkyl sulfates, alkyl sulfonates, alkyl carbonates, etc., or cationic surfactants such as quaternary ammonium salts. It is recommended to use something like In particular, nonionic polyoxyethylene alkyl ether is preferred because it does not reduce the stick prevention effect. Further, the addition of the above-mentioned wetting agent is not limited to one type, and the amount added may be appropriately determined in relation to the degree of repellency and stick prevention ability.

The polyester film used in the present invention has a thickness of 4
It is preferable that the porous support is less than μ, and porous Fj'JR paper (Tengucho), porous synthetic fiber paper, mixed paper, screen mesh, various woven fabrics, non-woven fabrics, etc. can be used as the porous support. I can do it. Further, the porous support and the polyester film can be laminated with or without an adhesive (eg, thermoplastic resin) (eg, thermal bonding).

[Example] The present invention will be further explained with reference to Examples below, but the present invention is not limited thereto.

2μ thick polyester film and tsubo 112g/ln
2 Tengucho paper is made of vinyl acetate-ethylene copolymerization (EVA)
A laminated heat-sensitive stencil paper was prepared using resin. In addition, the amount of adhesive resin attached is 1 to 3 g/7712.
After making one adjustment, it was coated on a polynisdel film using a wire bar (order of 0 and 3 diameters) and laminated by a wet lamination method.

Next, an overcoat layer having the contents shown in Table 1 below was coated on the film surface of this heat-sensitive stencil paper and dried.
Each product from No. 1 to H-2 was produced.

Furthermore, in this example, the amount of the anti-stick layer deposited is extremely small (0.5 per m2 of base paper).
In Table 1, the amount of the stick prevention layer adhered is expressed using the concentration of the coating liquid in consideration of measurement errors. The diameter of the wire bar used for coating was 0.
It is 1 μmφ.

Next, using the heat-sensitive stencil paper created as described above, the heat-sensitive recording facsimile receiver Rifax 5320H (
The perforation performance of each sample was evaluated by performing perforation with a thermal head in copy mode using a RICOH Co., Ltd. product. The results are shown in Table 2 below.

Table 1 Table 1 (continued) PPG-polypropylene glycol, PEG/PPG = polyethylene glycol/polypropylene glycol Table 2 From the above results, the conventional overcoat layer material provides satisfactory stick prevention when the applied amount is small. It can be seen that although no effect is obtained, the product of the present invention can sufficiently achieve its purpose with a small amount of coating. In addition, when the products of the present invention, Samples A-1 to F-2, were perforated using Lingraph FX7200 (manufactured by Riso Kagaku Kogyo), which is a perforation method using infrared irradiation, all the samples showed good original peelability and no damage to the film. There were no problems and a clear perforation image was obtained.

Furthermore, when the same procedure as in this example was carried out by changing the molecular weight and mixing ratio of polyethylene glycol and polypropylene glycol used as the stick-inhibiting agent in the present invention, almost the same results as above were obtained.

[Effects] According to the heat-sensitive stencil paper of the present invention constructed as described above, the following advantages can be obtained.

(1) Since the substance used in the present invention achieves the stick prevention effect with a very small amount of coating, the overcoat layer material hardly adheres or accumulates on the thermal head and has good perforation properties.

(2) Since the substance used in the present invention has a polypropylene group, it has good wettability to polyester films and the coating film is difficult to repel (even substances with molecules of 110,000 or more have less repellency), so when applying a dilute solution, the surfactant is Since only a small amount is added, the amount of head residue adhering to the head is reduced.

(3) Stick prevention prevents film fuzz and peeling.
The base paper runs smoothly without any phenomena such as tearing, and the running performance is improved.

Patent applicant Rico Co., Ltd. General Co., Ltd. 2-? l:I

Claims (1)

[Scope of Claims] A polyester film is laminated to a porous support, and at least one of a polypropylene glycol of the following formula I and a polyethylene glycol/polypropylene glycol block copolymer of the following formula II is applied to the surface of the film. or a stick prevention layer containing at least one of the polypropylene glycol and the block copolymer and a polyethylene glycol represented by the following formula III. , chemical formulas, tables, etc. ▼ Formula II ▲ Numerical formulas, chemical formulas, tables, etc. ▼ Formula III ▲ Numerical formulas, chemical formulas, tables, etc. ▼ (In each of the above formulas, m and n each represent an integer of 1 or more) .