PREPARATION OF PHENOL RESIN, CURING AGENT FOR EPOXY RESIN AND EPOXY RESIN MOLDING MATERIAL FOR USE IN SEALING ELECTRONIC PARTS

摘要

PROBLEM TO BE SOLVED: To provide a method for preparing a phenol resin which can be used as a curing agent capable of producing an epoxy resin which not only has a high glass transition temp. but also exhibits excellent resistance to reflow cracking when a packaged product manufactured using the epoxy resin is soldered onto a circuit board, a curing agent for an epoxy resin comprising the phenol resin, and an epoxy resin molding material for use in sealing electronic parts. ;SOLUTION: This method comprises reacting a mixture of a naphthol and a phenol having a naphthol content of 10 to 90% by mole with an aldehyde in the presence of an acid catalyst, followed by reducing the water content of the reaction system to a level of 5% or less, heating the reaction system at a temp. of 80 to 120°C for 1 to 2hr in the presence of a strong acid or a super acid, and then subjecting it to concentration under reduced pressure and/or steam distillation at a temp of 230°C or lower in order to remove the unreacted phenol. A curing agent for an epoxy resin comprising the phenol resin thus prepd., and an epoxy resin molding material for use in sealing electronic parts are also disclosed.;COPYRIGHT: (C)1997,JPO