Polymers for aqueous processed photoresists

Claim 1

A photopolymerizable composition in the form of a dry film on a support capable of being formed into rolls and exhibiting improved cold flow properties comprising: (A) from 10 to 60 parts by weight of one or more addition polymerizable non-gaseous ethylenically unsaturated compounds having a boiling point above 100° C.; (B) a photo-initiated free-radical generating addition polymerization initiating system; and (C) from 40 to 90 parts by weight of a preformed macromolecular polymeric binding agent which is a polymer of 40to 60 parts of a first monomeric material which contains one or more styrene-type compounds selected from the group having the general formula: ##STR2## wherein R is hydrogen, an alkyl group having from 1 to 6 carbon atoms or a halo group or ring-substituted derivative thereof; 15to 45 percent of a second monomeric material which contains one or more compounds selected from the group comprising alkyl acrylate, alkyl methacrylate, hydroxyalkyl acrylate or an hydroxyalkyl methacrylate wherein the alkyl groups have from 1 to 6 carbon atoms and the hydroxyalkyl groups have from 2 to 6 carbon atoms; and 15 to 40 percent of a third monomeric material which contains one or more alpha, beta-unsaturated carboxyl-containing monomers having from 3 to 15 carbon atoms; the preformed macromolecular binding agent, when dissolved in methyl ethyl ketone to form a 40% solution, having a viscosity of at least 2,000 centipoises on the Brookfield Viscometer; the photopolymerizable composition being soluble in an aqueous alkali solution having a pH of from 9 to 14 having a Sward hardness number of from 10 to 20 when in the form of a 1 mil thick film and a Sward hardness number of from 8 to 14 when in the form of 2 mil thick film.