Method for the continuous production of polybutylene terephthalate from terephthal acid and butane diole

US6657040B1 · kind B1 · utility

Assignee

• BASF SE

Inventors

• Thomas Heitz · Ludwigshafen am Rhein, DE
• Martin Klatt · Bad Dürkheim, DE
• Ralf Neuhaus · Drensteinfurt, DE

Key dates

• Filing date: Dec 19, 2001
• Grant date: Dec 2, 2003
• Expiry date: Apr 23, 2022

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G63/85
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The invention relates to a method for the continuous production of polybutylene terephthalate from terephthal acid and 1,4-butane diole, comprising the following stages: a) direct esterification of terephthal acid with 1,4-butane diole in a reactor cascade of at least two reactors b) pre-condensation of the esterification product obtained in stage a), c) polycondensation of the pre-condensate obtained in stage b), whereby the temperature of the reactor cascade in stage a) is progressively decreased during its operation.