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. 12, 1999
Filed:
Nov. 13, 1997
Heinz-Dieter Schumann, Maintal, DE;
Abstract
The present invention comprises a process for the production of flame-resistant polyesters with at least 50 mol-% ethylene carboxylate units through esterification or ester interchange and co-polycondensation of at least one diol and a dicarboxylic acid or its dialkyl ester with a carboxyphosphinic acid, whereby the carboxyphosphinic acid, before being added to the co-polycondensation mixture, is dissolved in ethylene glycol of not more than 90.degree. C., and the acid number of this solution is standardized to 50 to 350 mg KOH/g of carboxyphosphinic acid by adding at least one basic alkali metal compound in the absence of oxygen, and said solution is added to the co-polycondensation mixture during the second half of the esterification or ester interchange reaction.