Patent ID: 6562932
Filing Date: 2003-05-13
Classification: B32B,C08G

Abstract:
A process for the production of an optically clear, light-stable polyurethane-urea elastomer having an onset softening point of at least 130Â° C., comprising reacting:A) a liquid polyisocyanate or polyisocyanate prepolymer having an NCO group content of about 5 to about 50%, an average functionality of 2 to 3, a viscosity of less than 5,000 mPa.s at 25Â° C., and comprising the reaction product of: (1) from 20 to 100% by weight, based on 100% by weight of A), of a (cyclo)aliphatic polyisocyanate having an NCO group content of about 32% to about 50% by weight and a functionality of about 2, wherein said (cyclo)aliphatic polyisocyanate is selected from the group consisting of 4,4â€²-dicyclohexylmethane diisocyanate (rMDI), 1,6-hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), 1,4-cyclohexane diisocyanate (CHDI), m-tetramethylxylene diisocyanate (m-TMXDI), and mixtures thereof; and (2) from 0 to 80% by weight, based on 100% by weight of A), of at least one organic compound having at least two hydroxyl groups, and a molecular weight of from about 62 to about 8,000; and B) an isocyanate-reactive component comprising: 1) from 3% to 90% by weight, based on 100% by weight of component B), of at least one organic compound containing at least two aromatic amine groups, and having a molecular weight of 100 to 1,000; and 2) from 10% to 97% by weight, based on 100% by weight of component B), of at least one organic compound having at least two hydroxyl groups and a molecular weight of about 62 to 6,000; in the presence of C) at least one organometallic catalyst; wherein the components are casted in a mold at an isocyanate index of 95 to 120.