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:
Jul. 28, 1992
Filed:
Dec. 23, 1991
A Wayne Cooke, Charlotte, NC (US);
Barrie L Davies, Weddington, NC (US);
Hoechst Celanese Corporation, Somerville, NJ (US);
Abstract
Poly(butylene terephthalate) copolyester advantageous of use as sheath materials in bicomponent fibers are prepared by a process for preparing a high-molecular weight, linear copolyester by condensing 40-85 molar percent of terephthalic acid optionally in the form of a dialkyl ester, half of which component can optionally be replaced by another dicarboxylic acid also optionally in the dialkyl ester form, and 60-15 molar percent of a blend of dimethyl adipate, dimethyl glutarate and dimethyl succinate with an alkanediol of 2-6 carbon atoms in its carbon chain, at an elevated temperature in the presence of a conventional catalyst, in a first condensation stage which is an interesterification or esterification stage and a second condensation stage which is a polycondensation stage, whereby a copolyester melt is produce. The process comprises, before or during the first condensation stage, adding 0.005-0.1 molar percent, based on the total acid component, of a C.sub.6 -aryl or C.sub.7 -alkaryl ester of phosphorous acid or of phosphoric acid to the reaction mixture.