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:
Jan. 23, 1979
Filed:
Feb. 28, 1978
Applicant:
Inventors:
Klaus Burzin, Marl, DE;
Jorn Ruter, Marl, DE;
Assignee:
Chemische Werke Huels, A.G., Marl, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
260343 ;
Abstract
A process for the production of cyclic esters of undecanedioic acid with aliphatic diols comprising thermolyzing the corresponding linear polyesters derived from said acid and said diols under reduced pressure at temperatures of 200.degree.-300.degree. C in the presence of organotin and phosphonate catalysts, wherein the organotin catalyst is of the formula ##STR1## wherein R.sub.1 and R.sub.2 are alkyl of 1-18 carbon atoms, or aryl or aralkyl each of 6-36 carbon atoms, and the phosphonate is O,O-dialkyl-(3,5-di-tert-butyl-4-hydroxybenzyl)-phosphonate, the alkyl groups of which each contain 2-18 carbon atoms.