GB1228900A - - Google Patents

Abstract

1,228,900. Stabilized polyurethane elastomer compositions. SOC. BHODIACETA. 7 Oct., 1968 [10 Oct., 1967], No. 47476/68. Heading C3R. Stabilized polyurethane elastomer compositions comprise (a) a polyurethane obtained by the prepolymer method using as chain extending agent a bi-functional compound in which the functional groups comprise nitrogen atoms carrying labile hydrogen atoms, (b) an antioxidant containing at least two hydroxyaryl radicals, each substituted by at least one tertiary hydrocarbon radical, and joined to one another by an aliphatic carbon atom, (c) a substituted urea containing at least one unit of the formula in which the remaining valency of the nitrogen is substituted by a substituted or unsubstituted cycloaliphatic radical, and R is an aliphatic, cyclo-aliphatic or aromatic radical or a polyester or polyether residue. The substituted ureas may be those prepared by reacting an isocyanate with a cycloaliphatic N-cyanoethylated amine e.g. by reacting cyclohexylamine, 4,4<SP>1 </SP>- diaminodicyclohexylamine or 1,4-diamino cyclohexane with phenyl isocyanate, 4,4<SP>1</SP>-diisocyanato-diphenylmethane or 4,4<SP>1 </SP>- diisocyanato - dicyclohexylmethane. The substituted urea may be prepared beforehand and added to the elastomer solution or it may be prepared in situ. Suitable phenolic antioxidants are those of the formula The substituted urea and phenolic antioxidant are each generally used in amounts of 0.25 to 10%, preferably 1 to 5%, by weight based on the polyurethane. In the examples the polyurethanes are obtained by reacting 4,4<SP>1</SP>- diisocyanato-diphenyl methane with polyesters obtained from ethylene glycol, propylene glycol and adipic acid, neopentyl glycol and adipic acid or hexanediol and adipic acid, followed by chain extension with aminoacetic hydrazide or propylene diamine. The resulting solution in organic solvents may be wet spun to form filaments.