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:
May. 26, 1992
Filed:
Nov. 13, 1990
Applicant:
Inventor:
Edward F McBride, Wilmington, DE (US);
Assignee:
E. I. Du Pont de Nemours and Company, Wilmington, DE (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07C / ; C07C / ; 560 ; 560 ; 528 ; 528 ;
U.S. Cl.
CPC ...
560 87 ; 528272 ; 528295 ; 560 96 ;
Abstract
Allyl end-capped propylene terephthalate polyester oligomers are sulfonated in an aqueous system in the presence of a free radical initiator by a process in which only a part (about 15% to 40%) of the source of bisulfite is added at the start of the sulfonation step with the remainder being added later in that step, in such increments as will permit maintaining a clear single phase, to give sulfinate-containing sulfonated products, following which the sulfinate content is oxidized to give sulfonated end-capped propylene terephthalate polyester oligomers.