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. 13, 1993
Filed:
Dec. 31, 1991
Maria Spinu, Wilmington, DE (US);
E. I. Du Pont de Nemours and Company, Wilmington, DE (US);
Abstract
Polymers of the general formula R--(A-B-A-I)-.sub.x A-B-A-R and their preparation are disclosed. In the general formula, -A- is a polyhydroxy acid residue preferably a polymer of either 98 to 100% L-lactide or 98 to 100% D-lactide having a molecular weight of 500 to 40,000 and preferably 2,000 to 20,000, -B- is an oligomeric diol or diamine residue, having a number average molecular weight of 500 to 20,000 and preferably 2,000 to 8,000. The polymers are prepared by polymerizing a lactone onto the diol or diamine followed by reacting the resulting polymeric H-A-B-A-H with an diisocyanate or diacyl chloride to form the -L- chain extending units in the general formula.