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:
Sep. 08, 1992
Filed:
Jan. 16, 1991
Applicant:
Inventors:
Werner Auhorn, Frankenthal, DE;
Friedrich Linhart, Heidelberg, DE;
Primoz Lorencak, Ludwigshafen, DE;
Michael Kroener, Mannheim, DE;
Norbert Sendhoff, Gruenstadt, DE;
Walter Denzinger, Speyer, DE;
Heinrich Hartmann, Limburgerhof, DE;
Assignee:
BASF Aktiengesellschaft, Ludwigshafen, DE;
Primary Examiner:
Int. Cl.
CPC ...
D21H / ;
U.S. Cl.
CPC ...
1621682 ; 1621646 ; 1621683 ; 162183 ;
Abstract
Paper, board and cardboard are produced by draining a paper stock, containing undesirable substances, in the presence of hydrolyzed homo- and/or copolymers of N-vinylformamide having a degree of hydrolysis of not less than 60% and a cationic retention aid. According to the invention, faster drainage and improved retention are obtained compared with the use of known fixing agents.