초록

A heat curable thermosetting epoxy resin formulation useful for making prepregs and electrical laminates containing a viscosity modifier, wherein the viscosity modifier is:

대표청구항 ▼

[ What is claimed is:] [1.]1. A thermosetting resin composition comprising a heat-curable thermosetting resin having a molecular weight of from about 200 to about 3000, and from about 0.5 to about 40 percent by weight, based on the resin composition, of a viscosity modifier which is a thermoplastic

[ What is claimed is:] [1.]1. A thermosetting resin composition comprising a heat-curable thermosetting resin having a molecular weight of from about 200 to about 3000, and from about 0.5 to about 40 percent by weight, based on the resin composition, of a viscosity modifier which is a thermoplastic resin having a molecular weight of at least about 5000 and a hydroxyl content not exceeding about 0.2 hydroxyl equivalents per 100 g of the resin composition, said viscosity modifier used as a viscosity modifying additive to control the viscosity characteristics and flow characteristics of the heat-curable thermosetting resin while maintaining an adequate Tg in a final cured resin resulting from curing the heat-curable thermosetting resin; wherein the viscosity modifier is an oxazolidone ring-containing compound having a Tg of at least 86.degree. C. which is the reaction product of:a) a polyisocyanate having an isocyanate functionality of from about 1.9 to about 2.1;b) a polyepoxide having an epoxide functionality of from about 1.9 to about 2.1; and optionally,c) a chain extender.