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:
Mar. 14, 1995
Filed:
Mar. 07, 1994
Lloyd M Robeson, Macungie, PA (US);
George Davidowich, Allentown, PA (US);
Robert K Pinschmidt, Jr, Allentown, PA (US);
Air Products and Chemicals, Inc., Allentown, PA (US);
Abstract
The wet strength of cellulosic paper is improved by adding the combination of an amine-functional poly(vinyl alcohol) and a cellulose reactive size which is a 4 or 5 membered cyclic ester or anhydride having alkyl or alkenyl substituents of 4 or more carbon atoms. The amine-functional polymer is preferably a hydrolyzed copolymer of vinyl acetate and N-vinylformamide in which about 1-25 mole % of the monomer units are incorporated N-vinylformamide, and the cellulose reactive size is preferably an alkyl ketene dimer or an alkenyl succinic anhydride. A paper product is provided having improved wet-strength and containing normally 0.05 to 4.0 wt % based on the dry pulp of the additive amine-functional polymer and cellulose reactive size. The particular compounds which represent the polymer and the size cooperate to provide improvements in wet-tensile strength for paper which could not have been foreseen from the effects of either material acting alone.