BLOCK COPOLYMER, METHOD FOR PRODUCING SAME, EPOXY RESIN COMPOSITION, CURED PRODUCT, AND SEMICONDUCTOR ENCAPSULATING MATERIAL

摘要

Provided is a polysiloxane-polyalkylene glycol block copolymer which can be obtained by reacting a polysiloxane (A) having a functional group selected from among a carboxylic acid anhydride group, a hydroxyl group, an epoxy group, a carboxyl group, and an amino group, with a polyalkylene glycol (B) having a functional group selected from among a carboxylic acid anhydride group, a hydroxyl group, a carboxyl group, an amino group, an epoxy group, a thiol group, and an isocyanate group, wherein the content of a structure derived from the polysiloxane (A) is 20-90 mass% with respect to 100 mass% of the block copolymer. When added to an epoxy resin, this polysiloxane-polyalkylene glycol block copolymer is homogeneously and finely dispersed in the epoxy resin so that bleed-out of the block copolymer from an epoxy resin cured product that is obtained can be suppressed and the epoxy resin cured product can have reduced stress and increased toughness. Furthermore, a reduction in fluidity is suppressed by adding the block copolymer to the epoxy resin. Thus, the block copolymer is useful as a variety of additives, such as a surfactant and a resin modifier, and particularly suitable as a stress reducing agent for a semiconductor encapsulating material.