摘要 |
Disclosed is a photopolymerizable resin composition suitable for forming a solder mask layer, for example, on a printed circuit board. The photopolymerizable resin composition of the invention can be prepared in the form of an aqueous solution and is developable with water as the developer liquid so that the problems and disadvantages inherent in the use of organic solvents can be completely solved. The composition comprises, in addition to a photopolymerization initiator and a polyenic compound as a reactive diluent, a unique prepolymer as a resinous ingredient which is a copolymer of, for example, an alkyl (meth)acrylate and glycidyl (meth)acrylate modified at the epoxy groups in the copolymer partly by the reaction with (meth)acrylic acid and partly by the reaction with an onium group-containing compound, e.g. a quaternary ammonium compound, to impart solubility in water.
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