PURPOSE: To produce titled resin which provides moldings having excellent flexibility, water resistance, electrical properties, etc., by reacting a mixture obtained by adding a cyclopentadiene-derived oil having a specified viscosity to a reaction mixture of a phenol and an aldehyde during or after the reaction.
CONSTITUTION: In the reaction of (A) a phenol with (B) an aldehyde, a modified phenol resin having excellent flexibility, water resistance, electrical properties, etc., is prepared either by adding (C) a cyclopentadiene-derived oil having a viscosity at 25°C, of 100W50,000cp during the reaction or by adding component (C) after the reaction and reacting the resulting mixture. As the component (A), there can be mentioned phenol, cresol or bisphenol A and as the component (B), there can be mentioned acetaldehyde or furfural. The component (C) is a homopolymer or copolymer of a cyclopentadiene type monomer, having at least 30wt% of units derived from the monomer.
KOMAI HISATAKA
ISHIKAWA ATSUO
