Resin composition curable with an active energy ray containing photopolymerizable polyurethane

Claim 1

A resin composition curable with an active energy ray comprising: (i) a graft copolymerized polymer having a number average molecular weight of 5,000 or more and a weight average molecular weight of 50,000 or less which comprises a trunk chain composed mainly of structural units derived from at least one monomer selected from the group consisting of alkyl methacrylates, acrylonitrile and styrene and has graft chains having- structural units derived from at least one monomer selected from the group consisting of the monomers represented by the following formula I and other monomers presented by the formula II: ##STR6## (wherein R 1 is hydrogen or an alkyl or hydroxyalkyl group having 1 to 3 carbon atoms, R 2 is hydrogen or an alkyl or acyl group having 1 to 4 carbon atoms which may have hydroxy group, R 3 is an alkyl group having 2 to 6 carbon atoms, a halogen-substituted alkyl group having 2 to 6 carbon atoms, an alkylether group represented by the formula: ##STR7## (wherein 2≦m+n≦6, n≠0 and m≠0), or a phenylalkyl group represented by the formula: ##STR8## (wherein 2≦m+n≦4, or the case where n=0 or m=0 is contained), added to said trunk chain; (ii) a linear polymer having a number average molecular weight of 50,000 or more and a weight average molecular weight of 350,000 or less and having a glass transition temperature of 60° C. or more which comprises structural units derived from at least one monomer selected from the group consisting of methyl methacrylate, ethyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, benzyl methacrylate, acrylonitrile, isobornyl methacrylate, isobornyl acrylate, tricyclodecaneacrylate, tricyclodecane methacrylate, tricyclodecaneoxyethyl methacrylate, styrene, dimethylaminoethyl methacrylate and cyclohexyl methacrylate and other structural units derived from at least one monomer in amounts from 5 to 30 mole percent selected from the group consisting of the monomers represented by said formula (I) and the monomers represented by said formula (II); (iii) an esterified polyurethane obtained from oligoesterdiol or from oligoesterdiol and dihydric isocyanate which has a molecular chain terminal end being esterified with acrylic acid: and (iv) a photopolymerization initiator.