Process for substantially increasing the flexibility of a polyester

Claim 1

A process for substantially increasing the flexibility of a polyester in its final physical form comprising annealing at a temperature of at least 100° C. for a period of at least 5 minutes (A) a first polyester having an inherent viscosity of at least 0.6 prepared from at least (1) a dicarboxylic acid component which is (a) from 90 to 60 mole percent 1,4-cyclohexanedicarboxylic acid having a trans isomer content of at least 80 percent, and (b) from 10 to 40 mole percent dimer acid, and (2) 1,4-cyclohexanedimethanol having a trans isomer content of at least 60 percent, or (B) a second polyester having an inherent viscosity of at least 0.6 prepared from at least (1) 1,4-cyclohexanedicarboxylic acid having a trans isomer content of at least 80 percent, (2) a diol cmponent comprised of (a) 1,4-cyclohexanedimethanol, (b) from 20 to 50 weight percent, based on the weight of the polyester, of a poly(alkylene oxide) glycol having 2, 3 or 4 carbon atoms in the repeating unit and having a molecular weight in the range of 600 to 4,000.