Patent ID: 7488402

Claim:
A process for the production of paper from an aqueous suspension containing cellulosic fibers, and optional fillers, which comprises adding to the suspension (i) a cationic vinyl addition polymer prepared by polymerizing one or more ethylenically unsaturated monomers comprising a cationic monomer represented by the general structural formula (II): wherein R 3 is H or CH 3 ; R 1 and R 2 are each H or alkyl having from 1 to 3 carbon atoms; A 2 is O or NH; B 2 is an alkyl or alkylene group having from 2 to 8 carbon atoms, or a hydroxy propylene group; Q is a benzyl group; and X − is an anionic counterion, the cationic vinyl addition polymer being added in an amount of at least 0.001% by weight based on dry cellulosic fibers and optional fillers; and (ii) an anionic polymer having one or more aromatic groups, the anionic polymer being added in an amount of at least 0.001% by weight based on dry cellulosic fibers, and optional fillers, and wherein the anionic polymer is a sulphonated lignin polymer; wherein (i) and (ii) are separately added to the suspension; and (iii) an anionic microparticulate material selected from the group consisting of silica-based particles and clay of smectite type; and forming and draining the obtained suspension on a wire.