| abstract |
Sheet molding compound is prepared from unsaturated polyester resin syrup, particulate fillers, randomly oriented reinforcing fibers, a polyhydroxy polyacrylate or polyhydroxy polymethacrylate and an organic polyisocyanate. At the time of manufacturing the sheet molding compound, the organic diisocyanate combines with the polyhydroxy polyacrylate or polyhydroxy polymethacrylate to thicken the sheet molding compound without causing polymerization of the unsaturated polyester resin syrup. |