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. 24, 1992
Filed:
Jan. 09, 1991
Applicant:
Inventors:
Enrique Freudenberg, Schifferstadt, DE;
Friedrich Linhart, Heidelberg, DE;
Rainer Tresch, Maxdorf, DE;
Heinrich Hartmann, Limburgerhof, DE;
Walter Denzinger, Speyer, DE;
Michael Kroener, Mannheim, DE;
Norbert Sendhoff, Gruenstadt, DE;
Assignee:
BASF Aktiengesellschaft, Ludwigshafen, DE;
Primary Examiner:
Int. Cl.
CPC ...
D21H / ;
U.S. Cl.
CPC ...
1621682 ; 1621646 ;
Abstract
Paper, board and cardboard are produced from paper stocks containing foreign substances by drainage in the presence of a polymer which contains, as typical polymerized constituents, units of the formulae ##STR1## where R.sup.1 and R.sup.2 are each H, C.sub.1 -C.sub.3 -alkyl, and which have K values of not less than 130, the polymers containing less than 10 mol % of units of the formula II.