METHOD OF PRODUCING PHENOL RESIN

摘要

PROBLEM TO BE SOLVED: To provide a method of producing a phenol resin that can be used as a curing agent for semiconductor sealing material as it includes a reduced amount of ionic impurities and has a low molecular-weight and a low melt viscosity. SOLUTION: When a phenol and an aldehyde are allowed to react with each other to produce a phenol resin, a salt formed by the neutralization reaction between an acid and a base is used as a polymerization catalyst. The weight of the salt is 0.01-5 wt.% based on the whole weight of the phenol and the aldehyde. The catalyst is removed by washing with water or extraction treatment whereby the resultant phenol resin includes a reduced amount of ionic impurities and is useful as a curing agent for a semiconductor-sealing epoxy resin.