Patent · US Expired

Making paper, board and cardboard of high dry strength

US4940514A · kind A · utility

29Cited by

6References

6Claims

0Family size

Assignee

BASF SE

Inventors

Andreas Stange · Mannheim, DE
Hans-Juergen Degen · Lorsch, DE
Werner Auhorn · Bischofswerda, DE
Volkmar Weberndoerfer · Mannheim, DE
Michael Kroener · Mannheim, DE
Heinrich Hartmann · Schifferstadt, DE

Key dates

Filing date	Jul 25, 1988
Grant date	Jul 10, 1990
Priority date	—
Expiry date	Jul 25, 2008

Classification

Technology area (CPC D)Textiles; Paper
CPC primaryD21H21/18
WIPO fieldTextile and paper machines
WIPO sectorMechanical engineering

Abstract

Paper, board, and cardboard having high dry strength are made by adding to the paper stock a dry strength agent which is obtainable by mixing enzymatically digested starch having a viscosity of from 20 to 2,000 mPa.s (measured in 7.5% strength aqueous solution at 45.degree. C.) and a cationic polymer which contains, as typical copolymerized monomers, PA1 (a) diallyldimethylammonium chloride, PA1 (b) N-vinylamine or PA1 (c) an unsubstituted or substituted N-vinylimidazoline, the K value of the cationic polymer in each case being not less than 30, and draining the paper stock with sheet formation.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.