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:
Apr. 29, 1980
Filed:
Feb. 14, 1979
Applicant:
Inventors:
Gernot Horlbeck, Haltern, DE;
Klaus Burzin, Marl, DE;
Assignee:
Chemische Werke Huls A.G., Marl, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C08G / ;
U.S. Cl.
CPC ...
528274 ; 528298 ; 528309 ; 525437 ;
Abstract
In a process for preparing very viscous, heat-stable poly(butylene terephthalate) by condensing terephthalic acid, or a lower alkyl ester thereof, with 1,4-butanediol in two stages at an elevated temperature and in the presence of conventional catalysts, an improvement comprises carrying out the condensation in the presence of 0.5 to 15 mole %, relative to the number of moles of terephthalic acid units, of 9,10-dihydro-9,10-[cis-11,12-bis(hydroxymethyl)-ethano]-anthracene.