Low shrink low density laminate formulation

摘要

A multilayer composite contains a gel coat layer, a laminate layer, and a barrier layer disposed between the gel coat and the laminate layer. The laminate contains from 40-80% by weight paste and from 20-60% by weight reinforcing fibers. The barrier coat also comprises a cured polyester resin, and contains reinforcing fibers shorter than those in the laminate layer. The barrier layer has sufficient flexibility to avoid cracking during demolding and handling. Preferably, the barrier layer exhibits an elongation at break of more than 1%, and more preferably about 2% or more. The resin of the barrier layer can contain up to about 25% by weight of the resin of an isophthalic acid based polyester resin. The composites can be made using an open tool molding process.