Patent ID: 7041197

Claim:
A method for making a cellulosic paper to enhance its wet strength and softness, the method comprising: a) providing a pulp furnish containing at least one cellulosic component possessing anionic sites; b) adding separately to the pulp furnish to form a treated pulp, i. cationic wet strength resin possessing cationic sites which bond to anionic sites on the cellulosic component of the pulp furnish, there being present cationic wet strength resin possessing unbound cationic sites, and ii. anionic polyelectrolyte possessing anionic sites and hydrophobic groups, with anionic sites of the anionic polyelectrolyte bonding to unbound cationic sites of the wet strength resin; c) forming the treated pulp into a sheet; and, d) drying the sheet, wherein the anionic polyelectrolyte is made by reacting a polymeric compound having anhydride groups with an amine having the formula: HNR 1 R 2 wherein R 1 and R 2 are each selected from the group consisting of hydrogen and a saturated or unsaturated, straight chain or branched aliphatic group having from 1 to 36 carbon atoms, with the proviso that at least one of R 1 and R 2 is a hydrophobic saturated or unsaturated, straight chain or branched aliphatic group having from about 8 to about 36 carbon atoms, and wherein the polymeric compound having anhydride groups is a copolymer of ethylene and maleic anhydride and the amine is octadecylamine or N-methyl-N-octadecylamine.