The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 30, 1993
Filed:
Mar. 20, 1992
Applicant:
Inventors:
Assignee:
Zimmer Aktiengesellschaft, Frankfurt, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C08G / ; C08G / ; C08G / ;
U.S. Cl.
CPC ...
528279 ; 528272 ;
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.