Ciba Specialty Chemicals Corporation

Andr&eacute; Schmitter

Daniel Thibaut

Benjamin Breitenstein

Christoph Kleiner

Andr&eacute; Geoffroy

Matthias Von Frieling

Martin Von B&uuml;ren

Alfred Georges Oertli

A description is given of an extrusion process for the preparation of a low-dust stabiliser, using a subcooled melt as granulation liquid, as well as of novel amorphous modifications of different stabilisers, including 2,2&prime;-methylenebis(4-&lsqb;1,1,3,3-tetramethylbutyl&rsqb;-6-benzotriazol-2-yl-phenol), and of the &bgr;-crystalline modification of 2-(2-hydroxy-3,5-di-tert-butylphenyl)-5-chlorobenzotriazole and of the preparation thereof. The novel process affords products which are easy to handle and which are flowable, and the novel modifications have advantages as regards their preparation, processing and their use as stabiliser.

Preparation of low-dust stabilisers

This invention relates to compositions comprising a polycarbonate, polyester or polyketone which is subject to oxidative, thermal and/or light-induced degradation, or their mixtures and blends, and at least one benzofuran-2-one type compound, to the use thereof for stabilising polycarbonate, polyester or polyketone or their mixtures or blends against oxidative, thermal and/or light-induced degradation, as well as to a process for stabilising these plastic materials.

Stabilizing polycarbonates

A description is given of an extrusion process for the preparation of a low-dust stabilizer, using a subcooled melt as granulation liquid, as well as of novel amorphous modifications of different stabilizers, including 2,2&prime;-methylenebis(4-&lsqb;1,1,3,3-tetramethylbutyl&rsqb;-6-benzotriazol-2-yl-phenol), and of the &bgr;-crystalline modification of 2-(2-hydroxy-3,5-di-tert-butylphenyl)-5-chlorobenzotriazole and of the preparation thereof. The novel process affords products which are easy to handle and which are flowable, and the novel modifications have advantages as regards their preparation, processing and their use as stabilizer.

Preparation of low-dust stabilizers

Growing community of inventors

Hegenheim, France

André Schmitter

Growing community of inventors

Hegenheim, France

Andr&eacute; Schmitter

André Schmitter