GB1492500A - Photopolymerizable composition - Google Patents

Abstract

1492500 Photopolymerizable compositions MITSUBISHI RAYON CO Ltd 11 Dec 1975 50895/75 Heading C3R [Also in Division G2] A photopolymerizable composition comprises (a) 30-95 wt. per cent of an unsaturated polyester having an acid value of 5-100 derived from a carboxylic acid component at least 40 mole per cent of which is of the formula in which R 1 is hydrogen or C1-C4 alkyl, and a diol component, at least 30 mole per cent of which is of the formula in which R 2 is C2-C4 alkylene and n is an integer from 2-5; (b) 5-70 wt. per cent of a photopolymerizable unsaturated monomer, and (c) a photosensitizer. The unsaturated polyester of acid value 5-100 may be prepared by first preparing an unsaturated polyester having a hydroxyl value of 5-200 and then reacting this with a polycarboxylic acid or anhydride. The examples describe (a) unsaturated polyesters derived from α-methylene-#-methyl adipic acid with adipic, succinic, phthalic or terephthalic acids, and di-, tri- or tetra-ethylene glycol or dipropylene glycol, optionally with ethylene glycol or 1,4-butanediol, the unsaturated polyesters being optionally modified with phthalic anhydride, succinic anhydride, maleic anhydride or citraconic acid, (b) forming a photopolymerizable composition by mixing the unsaturated polyesters with various unsaturated monomers, e.g. a mixture of hydroxypropylmethacrylate, ethylene glycol dimethacrylate and triethylene glycol diacrylate, and a photosensitizer, and (c) coating the composition on a substrate, e.g. aluminium, polyester or polymethylmethacrylate, imagewise exposing the composition and washing out the uncured areas.