Positive type actinic-ray-curable dry film and pattern-forming method by use of the same

A positive actinic ray-decomposing and developing dry film having, on the surface of a nonactinic ray-decomposing and developing substrate removed after application, a solid positive type actinic ray-decomposing and developing urethane resin layer formed by coating and heat-crosslinking (1) a resin composition containing, as essential components, (A1) at least one unsaturated compound selected from the group consisting of a vinyl ether group-containing compound, vinyl ester group-containing compound and propenyl ester group-containing compound, (B1) an acid group containing urethane resin having a weight average molecular weight of 1,000 to 200,000 and an acid group content in the range of 0.5 to 10 equivalents per one kg of the resin, and (C) a photo-acid generator, (2) a resin composition containing, as essential components, (A2) at least one unsaturated urethane based compound selected from the group consisting of a vinyl ether uretriane based compound, vinyl ester urethane based compound and propenyl ester urethane based compound, (B2) at least one resin selected from the group consisting of (a) a carboxyl group and hydroxyphenyl group-containing polymer, (b) a carboxyl-group containing polymer and (c) a hydroxyphenyl group-containing polymer, and (C) a photo-acid generator, or (3) a resin composition containing, as essential components, (A2) at least one unsaturated urethane based compound selected from the group consisting of a vinyl ether urethane based compound, vinyl ester urethane based compound and propenyl ester urethane based compound, (B1) an acid-group containing urethane resin having a weight average molecular weight of 1,000 to 200,000 and an acid group content in the range of 0.5 to 10 equivalents per one kg of the resin, and (C) a photo-acid generator, the acid group-containing urethane resin (B1) being prepared by reacting a polyisocyanate, dimethylobutyric acid and a glycol, the vinyl ether urethane based compound being prepared by reacting a polyisocyanate compound, dimethylobutyric acid and glycol.