Process for the production of organic polyisocyanate-based molded polymers

摘要

An improved process for the production of organic polyisocyanate-based molded polymers prepared from at least one organic polyisocyanate and at least one polyol wherein there is employed an internal mold release agent comprising an amino-polysiloxane having at least one group of the formula RNH-alkylene-O- bonded to a silicon atom of a polysiloxane, wherein R is selected from the group consisting of hydrogen, lower-alkyl, cycloalkyl, and ECHR''CHR'- wherein E is an electron withdrawing group and R' and R'' are independently selected from the group consisting of hydrogen and methyl. The molding process can be repeated many times before the mold surfaces must be cleaned or treated with release agent. The ease of release of the molded polyurethanes makes the process particularly suitable for RIM production methods.