Photopolymerizable resin composition employing (meth) acrylonitrile in the linear copolymer to impart additional flexibility of the composition

摘要

The present invention relates to a photopolymerizable resin composition developable with an aqueous weak alkaine solution and suitable for a printed circuit board.PPThe photopolymerizable resin composition of the present invention is mainly composed of:PP(a) a linear acrylic copolymer,P P(b) an ethylenically unsaturated compound, andPP(c) a photopolymerization initiator,PPwherein said linear acrylic copolymer comprises as indispensable comonomers:PP i) at least one compound represented by the general formula: ##STR1## wherein X is a hydrogen atom or a methyl group, Y is an oxygen atom or an imino group and Z is an alkylene group having 1 to 5 carbon atoms, and PPii) an ethylenically unsaturated compound having a carboxyl group.PPthe photopolymerizable resin composition of the present invention can afford a resist film having excellent flexibility and adhesion through the use of the above-described particular linear acrylic copolymer. Therefore, when, for example, a printed circuit board is prepared by making use of the photopolymerizable resin composition of the present invention, occurrence of defectives can be remarkably reduced because no crack occurs on the resist film and no etchant penetrates into the gap formed between the resist film and the surface of the board.