JPH0123778B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an antistatic, light-shielding masking film comprising an antistatic, light-shielding release layer provided on a plastic support. One of the purposes of using the light-shielding masking film obtained in the present invention is to use it for photolithography, and by peeling off the required portion, various original images can be produced immediately. Conventionally, materials for the release layer of masking films used for this purpose include vinyl chloride resin, vinyl chloride copolymer, nitrocellulose,
Plasticizers and the like are used in addition to resins such as acetyl cellulose, but the surface of the release layer is highly sticky, the peel strength is low, and there are difficulties in workability. In order to improve the above-mentioned drawbacks, the present inventors
Compatible with nitrile rubber which has good adhesion to the plastic support as a release layer;
In addition, the use of a mixture of a substance that is not sticky at room temperature and a light-shielding dye and pigment was proposed in Japanese Patent Application Laid-Open No. 104902/1983. However, since plastic supports and compositions containing nitrile rubber all have electrical insulating properties, friction between masking films or between masking films and other substances occurs during the production or use of light-shielding masking films. When the material is electrostatically charged and peeled off, various problems occur due to the adhesion of dust and the like. Particularly in the case of photographic light-sensitive materials, the photographic light-sensitive layer is exposed to light during discharge, resulting in the formation of static marks. As a solution to this problem, a method is usually adopted in which an antistatic agent is added to a composition solution containing nitrile rubber. The viscosity of the coating solution to which the agent was added increased over time, making coating difficult in some cases. The present inventors have conducted extensive studies on antistatic agents that do not impair the releasability, flexibility, film formability, light shielding properties, and antistatic properties of the release layer and have excellent stability of coating liquid viscosity over time. As a result, it was discovered that ionic antistatic agents are preferable. That is, the present invention relates to an antistatically treated light-shielding masking film in which a nitrile rubber composition containing an ionic antistatic agent is coated on a plastic support. The present invention will be explained in more detail below. Examples of the plastic support used in the present invention include polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyoxybenzoate, or polycarbonate films, which may be stretched or unstretched. As the nitrile rubber composition, nitrile rubber or a mixture with a substance that is compatible with nitrile rubber and is not sticky at room temperature is used. As the nitrile rubber, an acrylonitrile-butadiene copolymer or an acrylonitrile-butadiene copolymer having an acrylonitrile content of 19 to 51% by weight is used.
Examples include terpolymers of carboxyl group-containing monomers. Further, substances to be used in combination with nitrile rubber include polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, nitrocellulose, polystyrene resin, polyacrylate resin, polyamide resin, polyvinyl acetal resin, etc. . One particularly preferred example is vinyl chloride-
It is a vinyl acetate copolymer, and the copolymerization ratio of vinyl chloride monomer and vinyl acetate monomer is 91 to 93 by weight.
It is preferably in the range of 9 to 17, and may also be a terpolymer resin containing a monomer containing a carboxyl group or a hydroxyl group. Next, any ionic antistatic agent used in the nitrile rubber composition of the present invention may be used as long as it is soluble in the solvent used for the nitrile rubber composition. For example, anionic antistatic agents such as alkyl sulfonates, allyl sulfonates, alkyl sulfosuccinates, amine salts of sulfuric acid esters, phosphate ester salts, alkyl carboxylates, alkyl amine salts, amidoamine or its salts, and esters. Examples include cationic antistatic agents such as amine quaternary ammonium salts, and amphoteric antistatic agents such as guanidine salts, betaine derivatives, and imidazoline derivatives. The amount of these antistatic agents added is 0.5 to the solid content in the nitrile rubber composition.
-5.0% by weight, preferably 1.0-4.0% by weight.
If the amount added is less than 0.5% by weight, there will be no antistatic effect, and if it is added more than 5.0% by weight, the antistatic effect will not change, but on the contrary, it will bleed onto the surface and become sticky.
Blocking tends to occur, which is undesirable. When a nonionic antistatic agent or a mixture of this and an ionic antistatic agent is used as an antistatic agent, the viscosity of the prepared coating solution increases over time, and coating becomes difficult in about 2 weeks to 1 month. I get used to it. As the coloring agent added to the nitrile rubber composition to impart light-shielding properties, dyes, pigments, and mixtures of dyes and pigments can be used. Any material may be used as long as it has good compatibility with the system composition and has little change in color tone with respect to heat and ultraviolet rays. As the solvent, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, ethyl acetate, butyl acetate, etc., and mixtures of these with benzene, toluene, xylene, etc. can be used. Next, the present invention will be specifically explained using examples. Examples 1 to 3, Comparative Examples 1 to 3 A light-shielding coating liquid containing no antistatic agent and having the following composition was prepared. Vinyl chloride-vinyl acetate (90:10) copolymer
140 parts by weight Nitrile rubber (AN content = 33%) 60 parts by weight 3:1 mixture of Neozapon Red GE and Neozapon Orange GR (dye) 16 parts by weight Mixture of methyl ethyl ketone/toluene (7:3) 1220 parts by weight Top coat Add various antistatic agents listed in Table 1 to the solution.
A light-shielding coating liquid with antistatic properties was prepared by adding 4.3 parts by weight. When the coating solution was left at 20°C and the viscosity change was measured over time, the viscosity of the systems containing the ionic antistatic agents of Examples 1 to 3 showed almost no change even after one month had passed. However, Comparative Examples 1 to 3
In the system containing the nonionic antistatic agent, an increase in viscosity over time was observed. The coating solutions of Examples 1 to 3 (one month after preparation) were coated on a biaxially stretched polyethylene terephthalate film having a thickness of 100 μm to give a thickness after drying.
It was applied to a thickness of 25μ and dried to obtain a ruby-colored transparent film. All of the obtained films had excellent antistatic properties, appropriate peel strength from the base film, and good light shielding properties, and no stickiness was observed on the surface. The coating liquids of Comparative Examples 1 to 3 had high viscosity and could not be coated. 【table】

Claims (1)

[Claims] 1. A light-shielding masking film that has been subjected to antistatic treatment, in which a nitrile rubber composition containing an ionic antistatic agent is coated on a plastic support.