Patent ID: 8518215

Claim:
A method of making paper providing improved strength and optionally retention and drainage and fixative properties, the method comprising the step of adding from 0.05 to 2.0 wt percent of a polymer based on the dry weight of pulp to the wet end of a paper machine, the polymer comprising randomly distributed repeating monomer units having at least one of the formulae (I) and (II): wherein X − is an anion; R 1 is a straight chain or branched alkyl group containing up to 12 carbons, optionally substituted with hydroxyl; R 2 and R 3 , identically or differently are H or a straight chain or branched alkyl containing up to 22 carbons; R 4 is H or a straight chain or branched alkyl containing up to 22 carbons; n 1 , and n 2 independently may be 0 mole percent; wherein the sum of n 1 and n 2 is greater than 0.1 mole percent and less than 20 mole percent; and wherein said polymer has a molecular weight in the range of from about 20,000 to about 800,000 Daltons.