MAKING PAPER, BOARD AND CARDBOARD OF HIGH DRY STRENGTH

摘要

O.Z. 0050/39344 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, a) diallyldimethylammonium chloride, b) N-vinylamine or 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.