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. 08, 1984
Filed:
Oct. 15, 1981
Shmuel Dabi, Fair Lawn, NJ (US);
Peter Loewrigkeit, Wyckoff, NJ (US);
Witco Chemical Corporation, New York, NY (US);
Abstract
A process for providing water based anionic polyurethanes having improved thermal oxidation color stability. Water dispersed amine salts of anionic prepolymers prepared from the reaction of polyhydroxy compounds and dihydroxy carboxylic acids with diisocyanates are chain-extended with hydrazine or hydrazide and thereafter optionally with a diamine, when cured at temperatures in excess of 150.degree. C., form polyurethane products having substantially no discoloration and good mechanical properties. Alternately, the hydrazide may be employed as an additive rather than as a chain-extender. The process is particularly useful when employing cross-linking agents which react only at high temperatures.