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:
Oct. 13, 1992
Filed:
Oct. 30, 1989
Robert K Pinschmidt, Jr, Allentown, PA (US);
Ta-Wang Lai, Novato, CA (US);
Lawrence K Wempe, Center Valley, PA (US);
Air Products and Chemicals, Inc., Allentown, PA (US);
Abstract
A modified poly(vinyl alcohol) copolymer is provided containing copolymerized units of allylamine and/or diallylamine by copolymerizing a vinyl ester, such as vinyl acetate, and an N-allylamide and/or N,N-diallylamide, such as N-allylformamide and/or N,N-diallylformamide and hydrolyzing first the ester groups to hydroxy groups and then the amide groups to amine groups. The second hydrolysis is carried out on solvent-swollen particulate polymer slurried in an acidic or basic medium. The modified polymer can contain small amounts of unhydrolyzed ester and amide groups in addition to the hydroxy and amine functionality which characterizes the copolymer.