CAST ARTICLE OF UNSATURATED POLYESTERS

摘要

Masonry blocks are provided with a cured resinous coating of an ethylenically-unsaturated polyester. The polyhydric alcohol in the ester is primarily neopentyl glycol to provide water resistance. The acid in the ester is isophthalic acid with 10 to 33% maleic anhydride, based on the total weight of the polyester. If the upper limit on the maleic anhydride is exceeded, stain resistance is lost. Triethyl phosphate is preferably incorporated to provide fire resistance while eliminating flame and smoke problems when employing methyl methacrylate as a polymerizable solvent. The sand-polyester compositions of the invention can also be formed as cast articles without a masonry unit backing.