Patent ID: 7776181
Filing Date: 2010-08-17
Classification: C08B,C08L,D21H

Abstract:
1. A method of papermaking, which comprises adding a composition for improving retention to stuff as a raw material for paper making, and then carrying out papermaking using said stuff to which said composition has been added, wherein said composition consists of (A) a cationic water-soluble polymer and (B) an amphoteric water-soluble polymer, in which said cationic water-soluble polymer (A) comprises 0.5 to 55.0 mole percent of a cationic radical-polymerizable monomer unit consisting essentially of a quaternary salt of a dialkylaminoalkyl (meth)acrylate, said amphoteric water-soluble polymer (B) comprises a cationic radical-polymerizable monomer unit consisting essentially of a quaternary salt of a dialkylaminoalkyl (meth)acrylate, an anionic radical-polymerizable monomer unit consisting essentially of a (meth)acrylic acid or a salt thereof, and a nonionic radical-polymerizable monomer unit consisting essentially of a (meth) acrylamide, and said component (B) has a molar proportion of the cationic radical-polymerizable monomer unit to the anionic radical-polymerizable monomer unit (hereinafter referred to as Ca/An) which satisfies a Ca/An of 5 to 15, and having a 0.5% salted viscosity of 10 to 80 mPa·s.