Preparation of low-dust stabilisers

US6740694B2 · kind B2 · utility

Assignee

• Ciba Specialty Chemicals Corporation · US

Inventors

• Daniel Thibaut · Michelbach-le-Bas, FR
• Andre Schmitter · Hégenheim, FR
• Benjamin Breitenstein · Rheinfelden, CH
• Christoph Kleiner · Aarau, CH
• Matthias von Frieling · Weil am Rhein, DE
• Martin Von Büren · Muttenz, CH
• Andre Geoffroy · Habsheim, FR

Key dates

• Filing date: Mar 23, 2001
• Grant date: May 25, 2004
• Expiry date: Aug 1, 2021

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C323/20
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

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′-methylenebis(4-[1,1,3,3-tetramethylbutyl]-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.