Phenol aralkyl resin composition and its use as a curing agent for epoxy resins.

摘要

A phenolic resin composition comprises a mixture of 100 parts by weight of a phenol aralkyl resin and 5 to 60 parts by weight of a novolak type phenolic resin having a content of binuclear components of not more than 10% by area, and a content of trinuclear components of not less than 50% by area and a sum content of tri- and tetra-nuclear components of 75% by area based on the total novolak phenolic resin except for the binuclear components. An epoxy-cured product is obtained by curing an epoxy resin while using the phenolic resin composition as a curing agent. The phenolic resin composition has a low viscosity and, when used as a curing agent for epoxy resins, the resulting epoxy-cured product has a low water absorption rate, excellent resistance to moisture and a high glass transition temperature as compared with the cured product obtained using a novolak type phenolic resin as a curing agent.