Patent ID: 6087465
Filing Date: 2000-07-11
Classification: C08G

Abstract:
Melt-processible poly(ester urethane) polymer, which contains structural units derived from a polyester and structural units derived from a diisocyanate, whereinthe polyester has a number average molar mass of 1,000 to 8,000 g/mol,the bonds between the structural units consist essentially of urethane bonds,50-99.9% of the polyester is formed by hydroxy acid monomer units and 50 to 0.1% of diol monomer units,the number average molar mass, M.sub.n, of the polymer is at least 10,000 g/mol, its weight average molar mass, M.sub.w, is over 20,000 g/mol and its molar mass ratio, expressed as the ratio M.sub.w /M.sub.n is over 2,the poly(ester urethane) is long-chain branched,the polymer is essentially free from free isocyanate groups, andthe poly(ester urethane) is obtained by copolymerizing the polyester with the diisocyanate at a temperature in the range of about 130.degree. C. to 240.degree. C. for a time period greater than about 30 minutes.