Patent · US Expired

Production of paper and paperboard of high dry strength

US4818341A · kind A · utility

30Cited by

2References

6Claims

0Family size

Assignee

BASF SE

Inventors

Hans-Juergen Degen · Lorsch, DE
Sigberg Pfohl · Speyer, DE
Volkmar Weberndoerfer · Mannheim, DE
Gerd Rehmer · Beindersheim, DE
Michael Kroener · Mannheim, DE
Andreas Stange · Mannheim, DE

Key dates

Filing date	Feb 12, 1988
Grant date	Apr 4, 1989
Priority date	—
Expiry date	Feb 12, 2008

Classification

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

Abstract

Paper and paperboard of high dry strength are produced by adding a dry strength enhancer to the paper stock and dewatering the paper stock with sheet formation by using as the dry strength enhancer a mixture of a cationic polymer which contains as characteristic monomers copolymerized units of PA1 (a) diallyldimethylammonium chloride, PA1 (b) N-vinylamine or PA1 (c) a substituted or unsubstituted N-vinylimidazoline and has a K value of not less than 30, and natural potato starch which is converted into a water-soluble form by heating in an aqueous medium at above the gelatinization temperature of natural potato starch in the absence of any oxidizing agents or alkali.

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