Process for the preparation of polyesters and copolyesters, the products prepared by this process and their use

US5736621A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Peter Simon · Marburg, DE
• Andree Henze · Hofheim, DE
• Karsten Blatter · Lechenich, DE

Key dates

• Filing date: Jun 27, 1996
• Grant date: Apr 7, 1998
• Expiry date: Jun 27, 2016

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G63/78
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A process is described for the preparation of polyesters by polycondensation of dicarboxylic acid-diol precondensates (oligomers) at elevated temperature in a liquid heat transfer medium in the presence of customary polycondensation catalysts and, if appropriate, cocondensable modifying agents, wherein the liquid heat transfer medium is inert and free of aromatic structural groups and has a boiling point in the range from 200.degree. to 320.degree. C., wherein the weight ratio of dicarboxylic acid-diol precondensate (oligomers) employed to liquid heat transfer medium is in the range from 20:80 to 80:20 and wherein the polycondensation is carried out in the reaction mixture at 200.degree. to 320.degree. C. in the presence of a dispersion stabilizer. Furthermore, the polyesters and copolyester which can be prepared by the process and their use are described.