Polymerization of the poly (1,4 - butylene rear phthalate) in the solid state of aggregation

摘要

1489430 Solid phase polymerization of polybutylene terephthalate GENERAL ELECTRIC CO 4 Oct 1974 [12 Nov 1973] 43172/73 Heading C3R Solid phase polymerization of particulate polybutylene terephthalate or a branched copolyester thereof with 0À01 to 3 mole per cent, based on the terephthalate units, of units of a branching compound, the polyester having an intrinsic viscosity of less than 1À05 dl./g., comprises heating particles of the polyester by themselves at a temperature of above 150‹ C. and below the melting point thereof until an intrinsic viscosity of at least 1À05 dl./g. is obtained. A vacuum may be applied to the particles during the heating step. The examples describe solid phase polymerization of polybutylene terephthalate and copolyesters thereof with trimethylolethane and pentaerythritol.