Increasing the molecular weight of polyesters

US6265533A · kind A · utility

Assignee

• Ciba Specialty Chemicals Corporation · US

Inventors

• Karin Regel · Hückelhoven, DE
• Roland Andernach · Lampertheim, DE
• Peter Schwarz · Speyer, DE
• Heinz Herbst · Herbstein, DE
• Kurt Hoffmann · Taufkirchen, DE
• Rudolf Pfaendner · Rimbach, DE
• Dirk Simon · Mutterstadt, DE

Key dates

• Filing date: Oct 19, 2000
• Grant date: Jul 24, 2001
• Expiry date: Oct 19, 2020

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08K5/5333
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

This invention relates to a process for increasing the molecular weight of polyesters, copolyesters or polyester blends by adding an organic phosphate to the processing apparatus and fusing the mixture to above the melting point, in which process the processing apparatus is a single-screw extruder, twin-screw extruder, planetary-gear extruder, ring extruder or co-kneader having at least one vent zone to which underpressure is applied.