JPH0335116B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to an improvement in a heat-sensitive stencil paper having a porous support layer and a heat-sensitive film layer. (Prior art) As a conventional heat-sensitive stencil paper of this kind, Mitsumata,
Porous supports such as paper, nonwoven fabrics, or woven fabrics made mainly of natural fibers such as Manila hemp, chemical fibers such as rayon, vinylon, polyester, etc., are vinylidene chloride-vinyl chloride copolymers, polyesters, etc. A method of making stencil paper from such base paper is to place the manuscript in close contact with the film of the base paper and flash light from a light source consisting of infrared, visible light to near-infrared light. This is done by melting, coagulating, etc., the part of the heat-sensitive film that is in contact with the black area of the document whose temperature has increased by irradiating it with light containing isothermal lines, or by bringing a heat-sensitive element into contact with the film of the base paper and heating it. . (Problems to be Solved by the Invention) Among the above-mentioned conventional techniques, for example, base paper using vinylidene chloride-vinyl chloride copolymer film as a heat-sensitive film can be made with relatively low energy; This poses a serious problem in practical use because it shrinks significantly over time and tends to curl. Additionally, base paper made from polyester film is currently widely used for office purposes, but in order to perforate it with low energy, it is necessary to reduce the heat capacity of the film and make it thinner. This decreases the film cost and increases the cost of the film, which is economically disadvantageous. The present invention overcomes the above-mentioned difficulties in the conventional technology, allows drilling with low energy, can be used for both hobby and office purposes, has excellent physical strength, and is low cost. The purpose of this invention is to provide a heat-sensitive stencil paper. (Means for Solving the Problems) The present invention can be summarized as a heat-sensitive stencil paper having a porous support layer and an ultraviolet irradiated polypropylene film layer. (Function) Many of the plastic films conventionally used were not modified by ultraviolet irradiation and did not become easily perforated by low energy. If a small amount of polyethylene film is used, it can be modified by ultraviolet irradiation, but it can only be made relatively thick, about 10 μm, and because of this, it is not expected that the heat capacity will decrease much, and favorable results cannot be obtained. Ta. On the other hand, according to the present invention, the polypropylene film itself can be manufactured as an extremely thin film, so that when it is irradiated with ultraviolet rays, a thin film that is extremely easily modified is formed.
It can perforate with low energy, and the perforation performance is improved even in the case of thin originals such as pencil writing (halftone), images with low carbon content, and dye-based black and blue, and the reproducibility of originals is good. You can achieve excellent results. In carrying out the present invention, the ultraviolet irradiation is carried out in a normal air atmosphere, and the polypropylene film is biaxially stretched or produced by the inflation method using a T-die. Can be done. Further, the timing of irradiating the polypropylene film layer with ultraviolet rays to obtain the base paper of the present invention is before winding up the film in the film forming process of the polypropylene film, immediately before laminating the polypropylene film to a porous support, or immediately before the polypropylene film is laminated onto a porous support. This may be carried out after the film is laminated to the porous support. The amount of ultraviolet rays irradiated is approximately 20KWatt
sec/ ^cm2 or more is desirable. The heat-sensitive stencil paper obtained according to the present invention can be plate-made by using conventionally used xenon lamps, tungsten lamps, halogen lamps, krypton lamps, infrared lamps, etc., or by using a thermal head. Furthermore, it goes without saying that in the present invention, the polypropylene film may be heat-sealed to the porous support without using an adhesive. (Example) Examples of the structure of the heat-sensitive stencil paper according to the present invention are as shown in FIG. As shown in the figure, although a porous support layer 1 and an ultraviolet ray irradiated polypropylene film layer 2 are bonded together by an adhesive layer 4, the image lines of the original are not fused by heat onto the ultraviolet ray irradiated polypropylene film layer 2. There is one in which anti-fusing layers 3 are sequentially provided to prevent fusion. Hereinafter, several types of samples were prepared for the heat-sensitive stencil paper according to the present invention and a conventional heat-sensitive stencil paper, and comparative tests were conducted. The sample was manufactured as follows. A porous support made of polyester tissue paper with a basis weight of 12 g/m ² and a saturated polyester resin (Vylon
300, manufactured by Toyobo Co., Ltd.) with an application amount of 2.5
g/m ² with a wire bar (0.3 mmφ) and irradiated with ultraviolet rays under the respective predetermined conditions as shown in Examples 1 to 5 in Table 1. A room temperature curing silicone (SR-2411, manufactured by Toray Silicone Co., Ltd.) was laminated onto the support, and a coating amount of room temperature curing silicone (SR-2411, manufactured by Toray Silicone Co., Ltd.) was applied as an anti-fusing layer to prevent fusing with the original image on the ultraviolet irradiated polypropylene film.
A heat-sensitive stencil paper according to the present invention was prepared by coating at a concentration of 0.2 g/m ² . Moreover, as comparative samples, polypropylene films and polyester films that were not irradiated with ultraviolet rays were used instead of the polypropylene films that were irradiated with ultraviolet rays in the above examples. Heat-sensitive stencil papers shown in Comparative Examples 1 to 3 were prepared.

[Table] Next, the heat-sensitive stencil sheets of the Examples and Comparative Examples shown in Table 1 above were used as manuscripts on high-quality paper (K・TOS81.4g/
Plate-making was carried out using offset printing on ^M2 (manufactured by Sanyo Kokusaku Pulp Co., Ltd.) using the plate-making machine and plate-making conditions described below. In this case, Table 2 shows the image density of original images (1), (2) and (3) printed on 1 cm squares measured by a Macbeth reflection densitometer and the dilution rate of the printing ink with the medium (resin for dilution). The printing ink used was "Hayabusa, manufactured by Osaka Ink Co., Ltd.".

[Table] In this case, the plate-making machine was a heat-sensitive stencil-making machine (V-1, manufactured by Tokyo Aircraft Instruments Co., Ltd.), and the plate-making conditions were standard conditions, that is, the voltage applied to the capacitor of the xenon lamp (a guideline for the amount of light) was 650 V. . The base paper made under the above conditions was stencil-printed using Risograph AP-7200 manufactured by Riso Kagakusha, and the density of the printed material corresponding to the image density of the original was measured using a Macbeth reflection densitometer. Table 3 shows the results.

【table】

[Table] As is clear from Table 3 above, it is clear that the printing density of the thermal stencil paper according to the present invention is excellent at any original density. )] It was confirmed that the present invention is superior to each comparative example. (Effects of the Invention) As explained above, the present invention uses ultraviolet irradiated polypropylene as a heat-sensitive film, thereby making image perforation possible with low energy.
In other words, when perforating with a conventional plate-making machine under the same perforation conditions, the perforation performance is improved even when using a thin original (halftone) such as a pencil drawing, and the reproducibility of the original is improved. Therefore, the present invention can produce various effects such as being able to use originals with a small amount of carbon, reducing white spots in solid areas, and making perforation possible even when using originals other than black, such as blue. can.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of one embodiment of the present invention, and FIG. 2 is a cross-sectional view of another embodiment. DESCRIPTION OF SYMBOLS 1... Porous support layer, 2... Ultraviolet irradiation polypropylene film layer, 3... Fusion prevention layer, 4...
...adhesive layer.

Claims (1)

[Claims] 1. A heat-sensitive stencil paper comprising a porous support layer and an ultraviolet irradiated polypropylene film layer bonded to the porous support layer.