PAPERMAKING ADDITIVE, PROCESS FOR PRODUCING PAPERMAKING ADDITIVE, AND PAPER CONTAINING PAPERMAKING ADDITIVE

摘要

A papermaking additive which brings about excellent drainage, excellent yield, and enhanced paper strength even when the effect of enhancing paper strength is difficult to obtain because the pH of the pulp slurry to be subjected to sheet formation fluctuates due to fluctuations in feed material quality, and because of impurity inclusion due to feed material deterioration and of an increase in the amount of fine fibers, etc.; and a process for producing the papermaking additive. The process comprises adding a polymerization initiator to a monomer mixture (A) comprising (a) a (meth)acrylamide, (b) a vinyl monomer having a carboxyl group and/or a sulfo group and a salt of the monomer, (c) a vinyl monomer having a tertiary or quaternary amino group, and (d) a crosslinking monomer to initiate polymerization and, at the time when 20 to 96% of the monomer mixture (A) has reacted, dropping a monomer solution (B) containing at least one of the monomers (a), (b), (c), and (d) to further conduct polymerization.