Abstract: A process for preparing inherently light- and heat-stabilized polyamides comprises polymerizing in the presence of at least one triacetonediamine compound of the formula where R is hydrogen or hydrocarbyl having from 1 to 20 carbon atoms, preferably alkyl having from 1 to 18 carbon atoms, or benzyl.

Abstract: A process for treating butanediol obtained as a condensate during the manufacture of polybutylene terephthalate, wherein an alkali metal alcoholate or alkali metal hydride is added to the condensate at an elevated temperature. After purification, the butanediol obtained is re-used for the manufacture of polybutylene terephthalate.

Abstract: A process for the continuous manufacture of linear, high molecular weight, polybutylene terephthalates, in which dimethyl terephthalate is trans-esterified with 1,4-butanediol, if desired in the presence of up to 40 mole% of other starting materials which form linear polyesters, in the molar ratio of from 1:1.2 to 1:1.5, in a plurality of successive stages at temperatures rising from 160.degree. to 230.degree. C, the mixture thus obtained is passed, at from 230.degree. to 270.degree. C and from 2 mm Hg to 20 mm Hg, upward through a bundle of stationary heated tubes, and immediately thereafter through a hold tank, with the proviso that the volume of the hold tank is at least 1/4 and at most 2.5 times the volume of the tube bundle and the mean residence time in the tube bundle and hold tank together is from 10 to 60 minutes, and the precondensate thus obtained is polycondensed at from 240.degree. to 260.degree. C and from 0.1 to 2 mm Hg. with continuous formation of thin films.

Abstract: Polybutylene terephthalate molding compositions containing from 0.5 to 20% by weight, based on the polyester, of an alkoxylated polyamide finely distributed therein to reduce the tendency of the polyester to electrification.