METHOD FOR PRODUCING NOVOLAC TYPE PHENOLIC RESIN AND NOVOLAC TYPE PHENOLIC RESIN

摘要

PROBLEM TO BE SOLVED: To provide a novolac type phenolic resin having high molecular weight and high heat resistance by introducing a monohydroxy aromatic aldehyde into the resin skeleton sufficiently.SOLUTION: A method for producing a novolac type phenolic resin comprises a first step of reacting first reactive phenols with a monohydroxy aromatic aldehyde in the presence of an acid catalyst to obtain a reactive phenols-aromatic aldehyde condensate, in which the first phenols comprise only a phenol having a substituent at only one meta position. The method may further comprise a second step of reacting the reactive phenols-aromatic aldehyde condensate, second reactive phenols and an aliphatic aldehyde. A substituent at the meta position of the first reactive phenols may be an alkyl group. The first reactive phenols may be m-cresol and/or 3-ethyl phenol.SELECTED DRAWING: None