Basf Aktiengesellschaft

Ludwig Beer

Wolfgang Seydl

Hermann Fischer

Karl Schlichting

Paul Matthies

Hugo Strehler

Eduard Heil

Friedrich Urbanek

Karlheinz Mell

Heinrich Mandel

Klaus Weinerth

Inherently light- and heat-stabilized polyamides

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.

Treatment of butanediol obtained as a condensate during the manufacture

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. The polybutylene terephthalates manufactured by the above process may be used for the manufacture of products such as fibers, films, sheeting and injection moldings.

Continuous manufacture of polybutylene terephthalates

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.

Antistatic polybutylene terephthalate molding compositions containing

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Ludwigshafen, Germany

Ludwig Beer