Process for continuous polycondensation of terephthalic acid and 1,4-bis(hydroxymethyl)cyclohexane

US5198530A · kind A · utility

Assignee

• Zimmer, Inc. · US

Inventors

• Manfred Kyber · Maintal, DE
• Wolfgang Schmidt · Frankfurt, DE
• Ulrich Thiele · Bruchköbel, DE

Key dates

• Filing date: Mar 20, 1992
• Grant date: Mar 30, 1993
• Expiry date: Mar 20, 2012

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G63/199
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

Process for continuous production of polyesters by esterification of terephthalic acid with 1,4-bis(hydroxymethyl)cyclohexane with a split feed in the presence of a titanium catalyst at 265.degree. to 305.degree. C. and 0.8 to 1.5 bar up to a conversion of 98.0% to 99.0%, then performing precondensation at 290.degree. to 305.degree. C. and 0.01 to 1.5 bar up to a conversion of 99.4% to 99.7% and finally performing polycondensation at 295.degree. to 310.degree. C. and less than 1.5 mbar up to a conversion corresponding to 50% to 95% of the maximum possible viscosity after adding more titanium catalyst.