Low-density molding compound

摘要

A molding composition formulation includes a thermoset cross-linkable polymeric resin. Glass microspheroids are present such that upon cure of the resin the resulting article has a linear shrinkage of less than ±0.06% and a density of less than 1.65. An article formed from such a composition is further strengthened by the addition of a surface activating agent bonded to the surface of the glass microspheroids. Conventional particulate fillers when added to an inventive formulation provide enhanced performance when the filler particle has a size sufficiently small to insert within adjacent microspheroid interstitial voids. An unsaturated polyester resin so formed is particularly well suited for the formation of sheet molding compound formulations.