Patent ID: 9175127
Filing Date: 2015-11-03
Classification: C08G

Abstract:
1. A method for producing an aliphatic polyester having an increased molecular weight comprising the steps of: (i) introducing into a mixing tank equipped with an inlet for injecting a diisocyanate: (ii) injecting the diisocyanate into the aliphatic polyester prepolymer, wherein the diisocyanate comprises isocyanate groups in an amount equivalent to between one tenth and two times the amount of the hydroxyl groups in the aliphatic polyester prepolymer and wherein the diisocyanate is injected into the aliphatic polyester prepolymer below a vapor phase portion of the mixing tank; and (iii) reacting the aliphatic polyester prepolymer with the diisocyanate, to obtain the aliphatic polyester having the increased molecular weight.