JPS6221596A - Thermal stencil paper - Google Patents

Abstract

PURPOSE:To ensure that perforation can be performed by a thermal printer, a thermal printing head can be smoothly moved, and clear images can be formed at high speed without accumulation of adhered matter, by adhering a porous base sheet to one side of a polyvinylidene fluoride film. CONSTITUTION:The polyvinylidene fluoride is a homopolymer or copolymer of vinylidene fluoride, in which the vinylidene fluoride content is preferably not less than 70mol%. The thickness of the film is 0.5-10mum, preferably, 1-5mum, and the film is preferably unidirectionally stretched. The porous base sheet preferably has a basis weight of 5-20g/m<2> and a thickness of 10-70mum. The film and the base are adhered to each other by applying an appropriate amount of an adhesive to the film, placing the base thereon and drying the adhesive by heating. Accordingly, stencil can be made directly from the stencil paper by a thermal printer without using manuscripts.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a base paper used for stencil printing, and more particularly to a heat-sensitive stencil paper that can be punched with a clear image at high speed.

(Prior art and its problems) Conventional stencil printing involves overlapping the original and heat-sensitive stencil paper and irradiating them with infrared rays. The mainstream is the thermal method, in which the plastic film of the base paper is melted and perforated by the heat generated by the heat source, and a perforated image is formed.However, in recent years, with the spread of office computers and word processors, thermal There is a rapidly increasing demand for the development of a method for directly making stencil paper for stencil printing without using a manuscript in a printer.

Conventionally, as heat-sensitive stencil paper, 1. ff IJ Bivinyl chloride Vinylidene chloride, polypropylene, ? It is used by attaching a film such as polyethylene terephthalate to a porous support such as Japanese paper, but when perforating this using infrared rays, a large output power is required from the light source.

Also, when using it as a base paper for a thermal printer,
The release agent adheres to the thermal printer, which is made up of a plurality of electrical point-shaped heating elements, making it difficult for the thermal printer head to move smoothly and increasing the number of drilling errors.

Additionally, if the application of mold release agent is omitted in order to avoid adhesion of the mold release agent, low molecular weight substances etc. leached from the film will adhere to the thermal printer head during perforation, which may cause problems when the mold release agent is applied. In the same way, the problem cannot be solved because the margrinter head is strained and drilling mistakes occur frequently in order to move smoothly.

In addition, polyethylene terephthalate film, which is most commonly used for heat-sensitive stencil paper, has a melting temperature of 26
Since the temperature is as high as around 0°C, it has the disadvantage that it is difficult to obtain a clear perforation image when perforated with a thermal printer, and this disadvantage becomes particularly noticeable when perforation is performed at high speed.

(Objective of the Invention) The present invention solves these problems, and when drilling with infrared rays, it is possible to form a clear image with a low-output light source, and it also makes it possible to perform drilling with a thermal printer. In addition, it is an object of the present invention to provide a heat-sensitive stencil paper that can smoothly move V-docks to a thermal printer and form clear images at high speed without the accumulation of deposits.

(Summary of the Invention) As a result of intensive studies, the present inventors have achieved the above object by the following means.

That is, the present invention relates to a heat-sensitive stencil paper formed by pasting a porous support sheet on one side of a polyvinylidene fluoride film.

(Detailed Description of the Invention) The polyvinylidene fluoride referred to in the present invention includes a homopolymer of vinylidene fluoride or a monomer of vinylidene fluoride, and a copolymer of vinylidene fluoride and other monomers such as fluoride. Copolymers with vinyl, ethylene trifluoride, ethylene tetrafluoride, vinylidene fluoride chloride, ethylene chloride trifluoride, propylene hexafluoride, etc. can be used.

The vinylidene fluoride content in the copolymer is preferably 70 moles or more.

Moreover, polymer blends of these polymers and other polymers such as polymethyl methacrylate can also be used.

Polyvinylidene fluoride film has a thickness of 0.5 to 10μ
, preferably 1 to 5μ.

If the thickness is less than 0.5μ, the strength will decrease and the film will be more likely to tear during the process of adhering to a porous support, which is not preferable.

Moreover, if it exceeds 10μ, the electric point heating element will not be able to make sufficient holes and a clear hole image will not be obtained.

It is desirable that the polyvinylidene fluoride film used in the present invention be stretched in at least one direction.

The stretching ratio used is 3 to 7 times, preferably 4 to 6 times. - The tensile modulus measured according to JIS K-7113 in the stretching direction is preferably 20,000'q/cm" or more.

Stretching ratio and tensile modulus are each less than 3 times, 20.
If it is less than 1,000 kglon, the film tends to wrinkle due to stretching and the perforation image tends to become unclear.

Furthermore, if the stretching ratio exceeds 7 times, the film tends to tear easily during the adhesion process with the porous support, which is not preferable.

Polyvinylidene fluoride film can be stretched in one direction or two directions, but if it is stretched in one direction, it is necessary to prevent wrinkles from forming due to stretching of the film during the process of attaching it to a porous support. In order to achieve this, it is preferable that the longitudinal direction of the film and the stretching direction coincide with each other.

The porous support referred to in the present invention is paper made from synthetic fibers such as polyester fibers, vinylon fibers, nylon fibers, or natural fibers such as Manila hemp, paper mulberry, and mitsumata, either singly or in combination.B is a nonwoven fabric of natural fibers. .

The porous support sheet preferably has a basis weight of 5 to 2017 m'' and a thickness of 10 to 70 μm. If the basis weight or thickness of the porous support sheet is less than 59/m2 and less than 10 μm, the adhesion to the film may be difficult. This is not preferable because the porous support becomes easily torn during the coating process. Also, if the basis weight or thickness exceeds 2017 m" and 701 t, respectively, too much printing ink will enter the porous support, resulting in clear problems. This is not preferable because it makes it difficult to obtain printed matter.

The polyvinidene fluoride film and the porous support can be attached by using an adhesive or by thermal welding. □When using an adhesive, known adhesives such as acrylic, vinyl chloride, polyester, vinyl acetate, and rubber adhesives can be used, but there are no particular limitations. It's not something you can do.

The dry coating amount of adhesive is 0.3 to 3. ! It is preferable to apply the coating so that the ratio is i'/m2.

The method of adhering the polyvinylidene fluoride film and the porous support is preferably to apply an appropriate amount of the adhesive to the film side, then overlap the porous supports, adhere them, and heat dry.

When using the heat-sensitive stencil paper of the present invention, the surface of the polyvinylidene fluoride film is perforated by applying an electric point heating element or infrared rays to form a perforated image. Next, the surface of the porous support is set in contact with the printing ink supply surface of a rotary press to absorb and retain the printing ink in the porous support, and the printing ink is absorbed and retained from the perforations in the film to the printing paper surface that contacts the film. It can be printed by infiltrating the perforated image through the holes.

(Effect of the invention) As described above, if the heat-sensitive stencil paper of the present invention is used,
It becomes possible to directly make a stencil sheet for stencil printing without using a manuscript with a thermal printer.

In addition, the thermal printer head moves smoothly,
Clear images can be formed at high speed without deposits.

When copying using a light source such as infrared light, a light source with low output can be used, which is practical.

Hereinafter, the present invention will be explained in detail with reference to Examples.

(Example) Polyvinylidene fluoride [KYNAR manufactured by Pennwalt Co., Ltd.]
i;;-Registered Trademark)] and polypropylene [Noblen (registered trademark) manufactured by Mitsubishi Yuka Co., Ltd.] on the front and back sides of this polyvinylidene fluoride, and after uniaxially stretching 5 times at 125°C, both sides were After removing the polypropylene on the side, a polyvinylidene fluoride film with a tensile modulus of 25,000 kg/cm in the stretching direction measured according to JIS K-7113 and a thickness of 4 microns was obtained.The obtained film was coated with acrylic. A paper based adhesive (solid content concentration 20 cm) was applied so that the dry coating amount was IJi'/m'', and then 80 parts of polyester fiber and 20 parts of Manila hemp were mixed together to obtain a paper with a basis weight of 1011/m. Porous supports having a size of 40 μm and a thickness of 40 μm were stacked and dried by heating at 90° C. to obtain a heat-sensitive stencil paper.

The obtained heat-sensitive stencil paper was set in a multi-printer (PCPR405) manufactured by NEC Corporation and perforated. During drilling, low molecular weight substances did not adhere to the thermal head, and the thermal head moved smoothly. The perforation image that could not be obtained was clear and no printing errors were observed.

The perforated heat-sensitive stencil paper was printed on a Gess 420W rotary printing press manufactured by Kestettner, and 3000 very clear prints were obtained.

Claims (1)

[Claims] A heat-sensitive stencil paper comprising a porous support sheet adhered to one side of a polyvinylidene fluoride film.