Internal mold release compositions containing phosphate esters

Abstract

Internal mold release compositions for molding polyurethane and polythiourethane is disclosed herein. The composition includes a mixture of: (a) a mono C.sub.2 -C.sub.6 alkyl phosphate; (b) a di C.sub.2 -C.sub.6 alkyl phosphate, wherein the alkyl groups of the di-alkyl phosphate may be the same or different, and wherein the alkyl groups of the mono- and di-alkyl phosphate may be the same or different; and (c) a C.sub.7 -C.sub.18 mono- and/or di-alkyl phosphate. Also disclosed is a polymerizable composition which includes (a) one or more monomers containing two or more isocyanate groups; (b) one or more monomers containing two or more functional groups selected from a thiol group and a hydroxyl group; (c) a mixture of a mono- C.sub.2 -C.sub.6 alkyl phosphate and a di- C.sub.2 -C.sub.6 alkyl phosphate, wherein the alkyl groups of the di-alkyl phosphate may be the same or different and wherein the alkyl groups of the mono- and di-alkyl phosphate mixture may be the same or different, wherein the mono- C.sub.2 -C.sub.6 alkyl phosphate is present in an amount of .gtoreq.20 wt %, based on the total weight of the mixture of the mono- C.sub.2 -C.sub.6 alkyl phosphate and the di- C.sub.2 -C.sub.6 alkyl phosphate. The composition can also optionally include the C.sub.7 -C.sub.18 mono- and/or di-alkyl phosphate.