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. 20, 1997
Filed:
May. 21, 1996
Claudia Nilz, Roedersheim-Gronau, DE;
Walter Denzinger, Speyer, DE;
Heinrich Hartmann, Limburgerhof, DE;
Michael Kroener, Mannheim, DE;
Friedrich Linhart, Heidelberg, DE;
Rudolf Schuhmacher, Boehl-Iggelheim, DE;
Dietmar Moench, Weinheim, DE;
Andreas Stange, Mannheim, DE;
BASF Aktiengesellschaft, Ludwigshafen, DE;
Abstract
Copolymers which are obtained by copolymerization of a) from 5 to 99 mol % of N-vinylcarboxamides, b) from 95 to 1 mol % of monoethylenically unsaturated carboxylic acids and/or the alkali metal, alkaline earth metal, ammonium or amine salts thereof, and if required, c) up to 30 mol % of other monoethylenically unsaturated compounds, and if required, d) up to 2 mol % of crosslinking agents, and subsequent partial or complete elimination of the acyl groups from the N-vinylcarboxamides polymerized in the copolymer, with formation of amino or ammonium groups, are used as additives to paper stock for increasing the drainage rate and the retention in papermaking, and the dry and wet strength of the paper.