Ciba Specialty Chemicals Corporation

Basf Se Corporation

Christoph Kleiner

Daniel Thibaut

Benjamin Breitenstein

Martin Von Büren

Andr&eacute; Schmitter

Andr&eacute; Geoffroy

Matthias Von Frieling

Martin Von B&uuml;ren

André Geoffroy

André Schmitter

A process for the preparation of a compound of formula (I)wherein

Method for preparing hydroxyphenyl carboxylic acid esters

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

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

Gipf-Oberfrick, Switzerland

Christoph Kleiner