Abstract:
Disclosed is a photosensitive resin composition containing a carboxyl group-containing photosensitive urethane resin (A), a photopolymerization initiator (B) and a photosensitive ethylenically unsaturated group-containing compound (C). This photosensitive resin composition is characterized in that the carboxyl group-containing photosensitive urethane resin (A) is a resin obtained by reacting a hydroxy group in a hydroxy group-containing urethane prepolymer (c) with an acid anhydride group in an acid anhydride group-containing compound (d). The hydroxy group-containing urethane prepolymer (c) is obtained by reacting a carboxyl group in a carboxyl group-containing urethane prepolymer (a), which is obtained by reacting a polymer polyol (e), a carboxylic acid compound (f) having two hydroxy groups in a molecule and a diisocyanate compound (g) as essential ingredients, with an epoxy group or an oxethane group in a compound (b) having an epoxy group or an oxethane group and an ethylenically unsaturated group. This photosensitive resin composition is excellent in sensitivity to an active energy ray and enables to form a fine pattern. A cured coating film of the photosensitive resin composition is excellent in flexibility, insulating property, adhesion, solder heat resistance, coating film resistance and flame retardance, and is thus suitably used for a photosolder resist.