Patent ID: 6806346
Filing Date: 2004-10-19
Classification: C08G,C09D

Abstract:
A process for the copolymerization of cyclic ester oligomers, comprising, contacting under ring opening polymerization conditions a mixture of two or more molten chemically different cyclic ester oligomers of the formula with a catalyst for the ring opening polymerization of cyclic ester oligomers, to form a copolyester, wherein:R1 and R2 are each independently hydrocarbylene or substituted hydrocarbylene; and m is an integer of 1 or more; and provided that when every R1 in each molecule of cyclic ester oligomer is not the same and/or every R2 in each molecule of cyclic ester oligomer is not the same, at least two of the chemically different cyclic ester oligomers present are at least 15 mole percent to total amount of cyclic ester oligomers present.