| 摘要 |
PROBLEM TO BE SOLVED: To provide a bisphenol S-containing high molecular wight epoxy resin having an aromatic ring or a heterocycle as substituents with excellent water resistance and high glass transformation temperature, a resin composition containing such high molecular weight epoxy resin, and a resin composition for printed wiring board made of such resin composition.SOLUTION: A high molecular weight epoxy resin having a weight average molecular weight of 10,000 to 200,000 in terms of standard polystyrene measured by gel permeation chromatography is provided by polymerization reaction of (X) a two-functional epoxy resin and (Y) a dihydric phenol compound containing as essential components a bisphenol S having an aromatic ring or a heterocycle as substituents in the presence of a catalyst. An epoxy resin composition containing the high molecular weight epoxy resin, other epoxy resin and an epoxy resin curing agent as essential components as well as a cured product obtained by curing the epoxy resin composition are also provided. |
