JPH0324357B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a heat-sensitive stencil plate in which a vinylidene chloride copolymer film and a porous thin paper or a mesh-like sheet are bonded together with an adhesive, and a silicone coating layer is provided on the surface of the vinylidene chloride copolymer film. It concerns the original paper.

Conventionally, a major drawback of heat-sensitive stencil paper is the problem of fusion between the heat-sensitive stencil film and the original during plate-making, especially for PPC originals copied using toner containing epoxy resin, urethane-based resin, or polyester-based resin. When using
In some cases, not only the manuscript but also the plate was damaged.

In order to prevent this fusion, it is possible to provide a release layer on the film surface that comes into contact with the original, for example, in
10093, Special Publication No. 47-5139, Special Publication No. 1009-1977,
It has been proposed in Special Publication No. 1531, Special Publication No. 48-30570, etc. In these known techniques, various fine powders of inorganic and organic substances, sodium stearate, surfactants, and silicone are used as materials to prevent the film and the original from fusing, but other than silicone cannot prevent fusing. It is sufficient, and the perforation clarity is also poor. The silicone used for this purpose is a high temperature curing type (cured at 100° C. or higher) silicone resin or silicone oil.

When using high-temperature curing silicone resin to form a release layer on a film, it must be heated to over 100°C to cure it, but since the film is extremely thin at around 10μ, fine wrinkles will occur due to heating. . These wrinkles extremely deteriorate the adhesion between the document and the film during plate making, reducing the clarity of the perforated image. Furthermore, when silicone oil is used, since it is liquid at room temperature, there are drawbacks such as staining the manuscript during plate making, or the release layer becoming sticky when touched by hand, resulting in the silicone oil being transferred to the hands.

The present invention provides a heat-sensitive stencil paper which has improved the above-mentioned drawbacks.

That is, the present invention provides a heat-sensitive stencil paper in which a vinylidene chloride copolymer film and a porous thin paper or a mesh-like sheet are bonded together with an adhesive, and a silicone coating layer is provided on the surface, and the silicone is a room-temperature curing silicone resin. This is a heat-sensitive stencil paper characterized by using.

The vinylidene chloride copolymer film used in the present invention preferably has a thickness of 8 to 15 μm,
In addition, porous tissue paper with a basis weight of 5 to 15 g/m ² is mainly made of natural fibers such as Manila hemp, kozo, and mitsumata, synthetic fibers such as polyester, vinylon, and acrylic, and semi-synthetic fibers such as rayon. Can be used. Furthermore, the mesh-like sheet is preferably one made of woven fibers of nylon, polyester, polypropylene, etc. with a thickness of 30 to 50 microns, and the lattice spacing is 50 to 150 microns.

As the adhesive, vinyl acetate resin, acrylic resin, and polyester resin can be used.

Next, the room temperature curable silicone resin used in the present invention includes all those in which the curing reaction proceeds without requiring heating above 100°C.
Tore Silicone manufactured by Tore Silicone Co., Ltd.
Examples include SR2402 resin, Toray silicone SR2410 resin, and Toray silicone SR2411 resin.

The effect of preventing fusion is greatly influenced by the amount of silicone resin applied, and the effect increases as the amount of application increases. However, if the coating amount is too large, the energy required for plate making will increase and the clarity of the perforated image will also drop significantly. Therefore, in order to obtain a practically satisfactory fusion prevention effect, it is necessary to apply an appropriate amount, and in the heat-sensitive stencil paper of the present invention, a dry weight of 0.02 to 2 g/m ² is suitable.

The thermal stencil paper of the present invention has the following features and advantages.

(1) Since no heat treatment is required to harden the silicone resin, the film does not undergo thermal shrinkage and does not produce any wrinkles that would prevent the reproduction of the original image.

(2) Since it forms a hardened film, it does not migrate like silicone oil and does not contaminate anything that comes into contact with the silicone film layer.

(3) Silicone has high mold releasability and is extremely effective in preventing adhesion, and since it is effective with just a small amount of application, the perforation image is sharp and has high resolution.

(4) Silicone has a low surface tension, and silicone paint spreads easily on the film surface, so it spreads over all parts and forms a thin film.

(5) The cured silicone resin coating is chemically inert and has long-term storage stability.

The present invention will be specifically explained below with reference to Examples.

Example 1 Saturated polyester resin (manufactured by Toyobo Co., Ltd.,
Byron 300) was dissolved in methyl ethyl ketone,
An adhesive solution with a solid content concentration of 10% was prepared. Using this adhesive, a 11μ thick vinylidene chloride/vinyl chloride copolymer film (Kureha Chemical Industry Co., Ltd., Klerap) was bonded to a 27μ thick porous thin paper with a basis weight of 8.7g/m ² and heat sensitive. A stencil paper was made. This is the standard product.

Next, a 1% methyl ethyl ketone solution of Toray Silicone SR2411 was applied as a release agent to the surface of the standard film, dried at 40°C for 15 minutes to form a release layer, and left at room temperature for 3 days. The coating amount of the release layer was 0.1 g/m ² .

Comparative Example 1 On the surface of the standard film prepared in Example 1,
A 1% n-hexane solution of silicone oil was applied as a release agent and dried at 40°C to form a release layer. The coating amount of the release layer was 0.2 g/m ² .

Comparative Example 2 High temperature curing type Shin-Etsu silicone as release agent
Add 4 parts by weight of catalyst PL-3 to 100 parts by weight of KS707, make a 2% solution with n-hexane, apply this solution to the surface of the standard film prepared in Example 1, and test the silicone release agent. It was heated for 10 seconds at 130°C, which is the minimum heating temperature required for curing, to form a release layer. The coating amount of this release layer was 0.2 g/m ² . Under these curing conditions, fine wrinkles appeared in the heat-sensitive stencil paper due to thermal contraction of the film. Wrinkles caused by heat shrinkage of the film during heat drying began to appear at around 50°C.

Example 2 4 parts by weight of catalyst SRX242AC was added to 100 parts by weight of Toray Silicone SR2402 as a release agent,
The solution was adjusted to 1% with n-hexane, and this solution was applied to the surface of the standard film prepared in Example 1, dried at 40°C to form a release layer, and left at room temperature for 3 days. The coating weight of the release layer was 1.5 g/m ² .

The heat-sensitive stencil sheets of Examples and Comparative Examples prepared as described above were made into plates using a plate making machine (manufactured by Riso Kagaku Kogyo Co., Ltd., FX-150).

First, a copy is made on high-quality paper using a PPC copying machine (manufactured by Sharp Co., Ltd., SF740), this copy is brought into close contact with the surface of a heat-sensitive stencil paper film, and exposed to xenon flash at a light intensity of S-5 from the thin paper surface. A perforation corresponding to the image was formed, the manuscript was separated, and a stencil for mimeographing was prepared. In the case of a standard product printed with this stencil using a rotary copying machine (REX ROTARY 1000), when the original was separated after being irradiated with xenon flash, the thick text or solid printing part of the original fused to the film surface, resulting in heat-sensitive The fused portion of the stencil paper and its surrounding area were also damaged. Even finer and smaller letters caused minute fusion, resulting in so-called print removal. When printing was carried out using this stencil, the mimeograph ink passed through the fused portion and the surrounding portion excessively, and a printed image reproducing the original image could not be obtained.

On the other hand, in the embodiment of the present invention, there are no wrinkles and no silicone migration, so there is no problem when separating the original after xenon flash irradiation, the separation is easy, and there is no melting on the original or the perforated part. No clothes were allowed. During printing, the flow of the mimeograph ink was extremely good, and as a result, the printed images were extremely clear, and we were able to obtain over 5,000 good-quality prints that faithfully reproduced the original images.

On the other hand, in Comparative Example 1, the silicone migrated to the original and seriously stained the original. In addition, the original was fused to the area where the silicone had transferred, resulting in plate removal. When printing using this plate, a clear image could not be obtained. In the case of Comparative Example 2, the wrinkles that occurred during heating and drying after silicone application inhibited the adhesion between the film surface and the original during plate making, and the areas that were not in close contact were not perforated, making it impossible to obtain a printed image that reproduced the original image. I couldn't.

Claims (1)

[Claims] 1. In a heat-sensitive stencil paper in which a vinylidene chloride copolymer film and a porous tissue paper or a mesh-like sheet are bonded together with an adhesive, and a silicone coating layer is provided on the surface of the film, a room temperature curing silicone resin is used as the silicone. A heat-sensitive stencil paper featuring the following.