Chemische Werke Huels Aktiengesellschaft

Huls Aktiengesellschaft

Joern Rueter

Roland Feinauer

Klaus Burzin

Karl-Heinz Magosch

Salih Mumcu

Hans J Panoch

Raban Grundamann

A precipitation procedure for preparing pulverulent coating compositions of high molecular weights by post condensation and based on polyamides having at least ten aliphatically bound carbon atoms per carbonamide group. The starting materials are uncontrolled polyamides having a relative solution viscosity of between 1.7 and 2.0 (measured in 0.5% meta cresol solution at 25.degree. C.) and contain not more than 0.2% by weight of phosphoric acid. After the cooling stage of the precipitation step of the polyamides, from 0.3 to 1.2% by weight of phosphoric acid referred to the polyamide are dispersed in the suspension prior to the precipitation in the solution or after the precipitation stage.

Process for preparing polyamide-based, pulverulent coating compositions

Cyclic esters of dodecanedioic acid with aliphatic diols of 2-12 carbon atoms in the chain and substituted by up to two alkyl of 1-4 carbon atoms, are produced by thermolysis of corresponding linear polyesters under reduced pressure in the presence of catalysts by subjecting the linear polyesters to thermolysis at temperatures between 200.degree. and 300.degree. C., and by utilizing as catalyst a tin(II) salt of an aliphatic monocarboxylic acid of up to 18 carbon atoms, of an aromatic or araliphatic monocarboxylic acid of up to 36 carbon atoms, of an aliphatic or aromatic hydroxy-, poly-, ketocarboxylic acid or of a dicarboxylic acid of up to 18 carbon atoms; or a mixture of an organotin compound of the formula ##STR1## wherein R.sub.1 and R.sub.2 are alkyl of 1-18 carbon atoms, or aryl or aralkyl of 6-36 carbon atoms, and an O,O-dialkyl-(3,5-di-tert.-butyl-4-hydroxybenzyl)-phosphonate wherein each alkyl is of 2-18 carbon atoms.

Process for the production of cyclic diesters of dodecanedioic acid

Nonflammable molding compositions consisting of:

Flame retardant polyesters

Growing community of inventors

Marl, Germany

Joern Rueter