JPH0641233B2 - Heat sensitive stencil paper - Google Patents

Description

TECHNICAL FIELD The present invention relates to a heat-sensitive stencil sheet having a polyester film provided with a non-stick layer made of a phosphate ester type surfactant on the surface thereof. More specifically, the present invention relates to a heat-sensitive stencil sheet used for digital plate making by thermal head writing.

[Prior art]

Up to now, a so-called heat-sensitive stencil sheet made by pasting a thermoplastic synthetic resin film with a porous support such as porous thin paper or screed mesh which can pass through ink is overlapped with the original, and the film is irradiated with electromagnetic waves including infrared rays. In the method of punching, it has been proposed to provide a release layer on the surface of the film for the purpose of preventing the film after punching from being fused with the original to make it difficult to peel off or damaging the film. However, in the conventional perforation method, the deposition amount of the release layer (overcoat layer) material is not largely affected by the deposition amount of the overcoat layer, and the film perforation property is not significantly affected. It was not so important as it did not cause any problems with drilling residue.

However, in the method of punching a film by thermal head writing, the type of the overcoat layer material and the amount of adhesion thereof greatly affect the punching performance. For example, if the adhesion amount is increased, there is a problem that the perforation property is deteriorated, and the overcoat material is adhered to and deposited on the head to deteriorate the performance of the thermal head. Therefore, the solution to this problem is how to prevent sticking with a small adhesion amount. Therefore, as one means, it has been proposed to perforate by sandwiching a paper between the thermal head and the heat-sensitive stencil sheet (see Japanese Patent Laid-Open No. 55-103957), but the energy of the current thermal head (heat capacity) is used. , Heat conduction, heat diffusion), it is impossible to perforate the film by this method. Further, even if the holes can be punched, the resolution is lowered and the image quality becomes poor.

〔Purpose〕

The present invention has been made in view of the above-mentioned present situation, and its purpose is to prevent thermal fusion of the polyester film to the thermal head during perforation of the heat sensitive stencil sheet by thermal head writing, blocking with a thermal head, To prevent secondary problems such as fluffing, tearing, and peeling of the film caused by the sticking phenomenon to improve the running property of the base paper during punching, and to prevent film scraps and sticking layer from sticking to the thermal head during punching. (Overcoat layer) The purpose is to prevent the coating substance from adhering to improve the running performance of the thermal head.

〔Constitution〕

In order to achieve the above object, the present invention is to provide a stick preventing layer made of a specific phosphate ester type surfactant on the surface of polyester. That is, according to the present invention, a polyester film is laminated on a porous support, and the film of the following formula I, formula II, formula III and formula I is formed on the surface of the film.
V or a phosphoric ester type surfactant represented by the formula V, or a phosphoric ester type surfactant represented by the following formula I, formula II, formula III, formula IV or formula V At least one of
A heat-sensitive stencil sheet is provided, which is provided with a stick prevention layer made of a combination with a phosphate ester type surfactant represented by VI.

Formula I Formula II Formula III Formula IV Formula V And formula VI In each of the above formulas, R represents an alkyl group or an alkylphenyl group, and in a surfactant, it usually has 8 carbon atoms.
It ranges from ~ 24. X represents a hydrogen atom or an alkali metal (when X is a hydrogen atom, it is not completely dissolved in water but coating is possible). N, which means the number of moles of ethylene oxide added, represents an integer of 1 or more, and one having a range of 1 to 20 usually has good solubility and is easy to use. However, even if it is larger than this, it does not change in terms of performance. As a typical example of the alkali metal, sodium or potassium can be given.

Such a phosphate ester type surfactant used in the present invention exhibits a high anti-sticking effect even with an extremely small amount of adhesion, and the amount of adhesion is 0.01 to 0.5 g / m ^2, preferably 0.05 to 0. 0.3 g / m ² is sufficient. The formation of a stick-preventive layer comprising a phosphate ester type surfactant on a polyester film is carried out by dissolving the surfactant in a suitable solvent such as water, ethanol, methanol, acetic acid ester or an organic solvent such as methyl ethyl ketone. Can be applied and dried. In this case, the concentration of the phosphate ester type surfactant in the solvent is 0.1 to 5% by weight, preferably about 0.5 to 3% by weight, and the drying condition is 70 to 100 ° C. for about 10 to 30 seconds. Good.

The polyester film used in the present invention has a thickness of 4
A material having a thickness of μ or less is preferable, and as the porous support, porous thin paper (standard paper), porous synthetic fiber paper, mixed paper, screen, various woven cloth, non-woven cloth and the like can be used. Further, the lamination of the porous support and the polyester film can be carried out with or without an adhesive (for example, thermal bonding).

〔Example〕

The present invention is further described below with reference to examples, but the present invention is not limited thereto.

A laminated heat-sensitive stencil sheet was prepared by using a polyester film having a thickness of 2 μm and a standard stencil paper having a basis weight of 12 g / m ² using a vinyl acetate-ethylene copolymerization (EVA) resin. The concentration of the adhesive resin was adjusted to be ² to 3 g / m ^2, and the polyester film was coated with a wire bar (0.3 mmφ) and laminated by the wet laminating method.

Next, an overcoat layer having the contents shown in Table 1 below was applied to the film surface of the heat-sensitive stencil sheet and dried to obtain A- shown in Table 1.
Products 1 to G-2 were produced.

Furthermore, in this example, the amount of the sticking prevention layer deposited was extremely small (0.5 g per 1 m ^{2 of} base paper).
In the following, in consideration of the measurement error, the adhesion amount of the stick prevention layer is expressed in Table 1 by using the concentration of the coating liquid. The diameter of the wire bar used when applying was 0.
It is 1 mmφ.

Next, the heat-sensitive stencil sheet prepared as described above was used to perform perforation by a copy mode thermal head using a thermal recording type Facsimile receiver Rifax 5320H (manufactured by Ricoh), and the perforation performance of each sample was evaluated. The results are shown in Table 2 below.

Incidentally, in the surfactant shown in the product of the present invention, With the diester type of Since it is difficult to completely separate it from the monoester form of Is also included, and similarly, the samples of B-1 and B-2 Also, the C-1 and C-2 samples are However, the D-1 and D-2 samples are , And the E-1 and E-2 samples are It also includes some. The samples of F-1 and F-2 are It includes a little.

From the above results, it can be seen that when the coating amount of the conventional overcoat layer is reduced, the effect of preventing sticking cannot be obtained, but with the product of the present invention, the purpose can be sufficiently achieved with an extremely small coating amount. In addition, a lithographic method for piercing the samples A-1 and B-2 of the present invention by infrared irradiation.
When punched using FX7200 (manufactured by Riso Kagaku Kogyo Co., Ltd.), clear peeling images were obtained without any problems such as breakage of the film with good document peeling property for all the samples.

Further, the same results as the above results were obtained by carrying out the same procedure as in this example by changing the type of the alkyl group and the number of moles of oxyethylene added of the phosphate ester type surfactant used as the anti-stick agent in the present invention. Was obtained.

[Effect]

According to the heat-sensitive stencil sheet of the present invention configured as described above, the following advantages can be obtained.

(1) Since the phosphate ester type surfactant used in the present invention achieves the sticking prevention effect with an extremely small coating amount, the overcoat layer material hardly adheres to and deposits on the thermal head and has good perforation property.

(2) Film fluffing, peeling, and
Phenomena such as tearing do not occur and the perforation quality is good, so a high quality image can be obtained.

(3) The running performance of the base paper is smooth, and the running performance (at the time of punching) is improved.

(4) Due to the nature of the phosphoric acid ester type surfactant used in the present invention, the adsorption force (ion adsorption) on the film surface is strong (because of the high oil film strength), the amount of scraping off by the thermal head is small, and therefore the adhesion. The amount deposited is also very small.

(5) Since the phosphate ester type surfactant used in the present invention has an antistatic effect, the coated film is free from dust, dust, and dust due to static electricity, and is easy to process without sticking to the film.

Claims (1)

[Claims] 1. A polyester film is laminated on a porous support, and the film of the following formula I and formula II is formed on the surface of the film.
A phosphate ester comprising at least one of the phosphate ester type surfactants represented by Formula III, Formula IV or Formula V, or represented by the following Formula I, Formula II, Formula III, Formula IV or Formula V A heat-sensitive stencil sheet, which is provided with a stick-preventing layer made of a combination of at least one type of surface active agent and a phosphoric acid ester type surface active agent represented by the following formula VI. Formula I Formula II Formula III Formula IV Formula V Formula VI (However, in each of the above formulas, R represents an alkyl group or an alkylphenyl group, X represents a hydrogen atom or an alkali metal, and n represents an integer of 1 or more.)