JPH1134521A - Thermal transfer medium for producing negative or positive film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a plate making sheet for high resolution, high gradation pattern more economically by adding a UV-ray absorbent into a thermal transfer layer. SOLUTION: An easily peelable layer is provided on a support and then a coloring agent layer and an adhesive layer being printed adhesively to a body being bonded, i.e., a transparent or a translucent sheet, are laminated sequentially thereon. Subsequently, a UV-ray absorbent is added into the peelable layer, the coloring agent layer or the adhesive layer. Preferably, it is added into the coloring agent layer. Among benzophenobe based, cyanoacrylate based, salicylate based or benzotriazole based UV-ray absorbents, the benzotriazole based UV-ray absorbent most effective in the UV-ray wavelength region for plate making is employed in the UV-ray absorbent layer. According to the arrangement, an extremely high resolution, high gradation plate making sheet can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer medium, and more particularly, to a high-definition, high-gradation plate making by printing a desired pattern on a transparent or translucent substrate using a thermal head or the like. The present invention relates to a heat-sensitive transfer medium capable of producing a negative or positive sheet.

[0002]

2. Description of the Related Art Conventionally, in the field of printing, when producing a negative film or a positive film for producing a printing plate, a silver halide film is photographed with a camera or the like, and then developed.
The use of photoengraving technology performed in steps such as fixing and drying was common. For this reason, photoengraving requires many work steps, and requires advanced technology and expensive equipment. In addition, there is already a technique for producing a negative film by peeling using a thermal transfer printer.For that purpose, a negative sheet, a special sheet having a UV blocking layer for production to be a positive sheet, and a negative film using a thermal head, A heat-sensitive ribbon for peeling required for producing a positive film was required. Also, in the method of producing a negative film by peeling, when producing a positive film, it is necessary to peel most of the special sheet for production with a thermal ribbon for peeling, which requires a large amount of thermal ribbon for peeling, and is economical. Was also a problem.
Technically, when a positive film is produced with high precision, it is necessary to completely separate the film, and a high level of technology is required.
In addition, a conventional black thermal transfer medium may be used for printing on an OHP sheet or the like, but has a poor concealing property, and does not have a sufficient ultraviolet shielding effect for preparing a negative for a plate making and a positive sheet using ultraviolet rays.

[0003]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a transparent or translucent base using a heat-sensitive transfer medium coated with a heat-sensitive transfer layer having an ultraviolet absorber on a support. It is possible to print and produce a desired pattern on a material with a thermal head or the like, and to produce a negative / positive film that enables simpler and more economical, high-definition, high-gradation pattern reproduction. It was possible to reproduce a high gradation pattern.

[0004]

In order to solve the above-mentioned problems, the heat-sensitive transfer medium for producing a negative / positive film of the present invention is a heat-sensitive transfer medium comprising a support and an easily peelable heat-sensitive transfer layer provided on a support. And an ultraviolet absorber is contained in the thermal transfer layer. Any plastic film can be used as the support. For example,
Examples thereof include polyolefins such as polyethylene and polypropylene, polyethylene terephthalate, polyvinyl chloride, acrylonitrile-butadiene-styrene copolymer, polyethylene naphthalate, and the like. In general, polyethylene terephthalate having good heat resistance and mechanical strength is easily used. Further, in order to prevent hot sticking at the time of printing with a thermal head, an antistatic agent composed of a heat-resistant silicone resin or a surfactant may be applied to the back surface of the support.

[0005] As the heat-sensitive transfer layer, a release layer which can be easily peeled off is provided on the support, a colorant layer is provided on the release layer, and further, it can be printed and adhered to a transparent or translucent sheet as an adherend. Various adhesive layers are sequentially laminated and formed. In addition, there is no problem even if a mixture of the colorant layer and the adhesive layer, the release layer and the colorant layer, or the release layer, the colorant layer and the adhesive layer is used. An ultraviolet absorber for the function of the present invention may be added and blended to the release layer, the colorant layer or the adhesive layer, but is not particularly limited, but is preferably blended to the colorant layer. The reason is that when printing with a thermal head, a short printing operation with low energy is required, so the peeling sensitivity needs to be increased, and the peeling layer function needs to be enhanced. is there.
Although there is no problem in adding and blending in the adhesive layer, it is necessary to give priority to the print adhesion function to a transparent or translucent sheet used as an adherend. As the release layer, wax having a melting point of 60 to 120 ° C can be used. For example, carnauba wax, paraffin wax,
Montan wax, ester wax, higher fatty acid, higher fatty acid amide, higher fatty acid ester and the like can be generally used.

The release layer is preferably applied in a thickness of 0.5 to 3.0 μm by various coating methods such as gravure coating, roll coating, bar coating, knife coating and blade coating. Colorant layer is acrylic resin, acrylic urethane resin, urethane resin, cellulose resin,
Ethylene-vinyl acetate resins, chlorinated polypropylene resins, chlorinated polyethylene resins, diallyl phthalate resins and the like are generally used. In the colorant layer, dyes necessary for coloring, inorganic pigments such as carbon black, and organic pigments may be used. In particular, carbon black is excellent in the function of blocking ultraviolet rays among inorganic pigments, and is also suitable for checking print quality, and is preferably used. The ultraviolet absorber layer used to have the ultraviolet blocking function of the present invention is generally a benzophenone-based, cyanoacrylate-based, salicylate-based, benzotriazole-based ultraviolet absorber, etc. 360 to 380 nm, which is the ultraviolet wavelength range
It is preferable to use a benzotriazole-based ultraviolet absorber which is most effective. It is effective to mix the ultraviolet absorber in a range of 5 to 30% based on the total solid content of the colorant layer.

The thickness of the colorant layer is preferably in the range of 0.5 to 4.0 μm, and is preferably applied by various coating methods such as gravure coating, roll coating, bar coating, knife coating and blade coating. If it is less than 0.5 μm, it is difficult to obtain an ultraviolet blocking function. If it exceeds 0 μm, there is a disadvantage that a pattern with higher definition and higher gradation cannot be printed. In order to improve the abrasion resistance of the colorant layer, a natural wax, a synthetic wax, or the like may be appropriately added as needed. Further, a metal deposited layer of aluminum or the like may be provided after the application of the colorant layer, so that the effect of blocking ultraviolet rays can be further enhanced. As the adhesive layer, it is necessary to use an adhesive that can be printed and adhered to a transparent or translucent plate-making sheet as an adherend, and generally, carnauba wax, acrylic resin, ethylene-vinyl acetate resin , Polyolefin resin, urethane resin, epoxy resin and the like. The adhesive layer is preferably applied in a thickness of 1.0 to 3.0 μm by various coating methods such as gravure coating, roll coating, bar coating, knife coating, blade coating and the like.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments.

[0009]

Example 1 [Release layer] Montan wax 5.0 (parts by weight) Toluene 76.0 Xylene 19.0 Total 100.0 [Coloring layer] Ethylene-vinyl acetate resin 16.0 (parts by weight) carbon black 10.0 Benzotriazole UV absorber 4.0 Polyethylene wax 3.0 Methyl ethyl ketone 60.0 Toluene 7.0 Total 100.0 [Adhesive layer] Carnauba wax emulsion 32.0 (parts by weight) (NV = 30%) Ethylene -Vinyl acetate resin emulsion 2.0 (NV = 20%) Methanol 66.0 Total 100.0 3.5 [mu] m One side of a polyethylene terephthalate film which has been subjected to a back treatment with a thickness of 3.5 [mu] m, and a dry film thickness of 1 [mu] m by a gravure coating method. And a colorant layer having a dry film thickness of 1 μm on the release agent layer. Form, further an adhesive layer to prepare a thermal transfer medium having a dry film thickness of 1.0μm formed present invention to the colorant layer. Using the thermal transfer medium of the present invention, a desired pattern was printed on a sand-matted translucent PET film using a thermal head. As a result, a very high-definition, high-gradation plate-making sheet was obtained.

[0010]

[Example 2] [Release layer] Montan wax 5.0 (parts by weight) Toluene 76.0 Xylene 19.0 Total 100.0 [Coloring layer] Acrylic urethane resin 14.0 (parts by weight) Dye 3.0 Benzotriazole UV absorber 3.0 Methyl ethyl ketone 72.0 Cyclohexanone 8.0 Total 100.0 [Metal deposited layer] Aluminum vacuum deposited layer 20 nm (High frequency induction heating method) [Adhesive layer] Polypropylene resin 64.0 (parts by weight) (NV = 15%) Ketone resin 2.0 Silica 2.0 Toluene 32.0 Total 100.0 3.5 μm One side of a polyethylene terephthalate film having a 3.5 μm thick back surface processed by a gravure coating method and a dry film thickness of 1 μm And a colorant layer having a dry film thickness of 1 μm is formed on the release agent layer, Aluminum film deposition film thickness 20 by wave induction heating method
After forming the film, an adhesive layer was formed on the vacuum-deposited layer to a dry thickness of 1.0 μm to prepare a thermal transfer medium of the present invention.
When a desired pattern was printed on a transparent OPP film using a thermal head by using the thermal transfer medium of the present invention, an extremely fine and high gradation plate-making sheet was obtained.

[0011]

The heat-sensitive transfer medium of the present invention is a heat-sensitive transfer medium for producing an extremely high-definition, high-gradation negative or positive for plate making on a transparent or translucent sheet using a general thermal head. It was effective as a medium manufacturing method.

Claims (1)

[Claims] 1. A heat-sensitive transfer medium for producing a negative / positive heat-sensitive transfer medium comprising a heat-sensitive transfer layer having an easily peelable heat-sensitive transfer layer provided on a support, wherein the heat-sensitive transfer layer contains an ultraviolet absorbent.