Preparation of high-viscosity mixtures containing thermoplastic polyesters

摘要

An improvement in a process for preparing an antimony oxide stabilized polymethylene terephthalate polymeric composition wherein polymethylene terepthalate is produced by polycondensing a polymethylene terephthalate precondensate, the improvement residing in compounding said precondensate with said antimony oxide and thereafter subjecting the resultant composition to solid phase polycondensation. In particular is described a process for the stabilization of high molecular weight (high viscosity) polymethylene terephthalate wherein together with the antimony oxide there is added a stabilizer or other additive to the precondensate and the resultant composition is subjected to solid phase polycondensation. Also described are the resultant products of such processes.