PROCESS FOR THE PRODUCTION OF CELLULAR POLYURETHANE ELASTOMERS

摘要

Mo-2055 LeA 19,643 PROCESS FOR THE PRODUCTION OF CELLULAR POLYURETHANE ELASTOMERS The instant invention is directed to a process for the production of a cellular polyurethane elastomer having a density of 0.45 to 0.8 g/cm3, comprising: (a) preparing a prepolymer having an isocyanate content of 10 to 25% by weight from aromatic polyisocyanates and a portion of one or more polyhydroxyl compounds having a molecular weight of from 400 to 6,000; and (b) reacting said prepolymer with the remainder of said polyhydroxyl compound and water; wherein the quantity of said water is 0.3 to 1% by weight and the equivalent ratio of isocyanate groups to isocyanate reactive compounds is in the range of 0.95:1 to 1.1:1, characterized in that from 0.1 to 0.8% by weight, based on the whole reaction mixture, of aromatic diprimary diamines having a molecular weight from 108 to 500 are also used in (a) or (b). LeA 19,643