| abstract |
According to the present invention, the following general formula (1):n n n (One)n n n At least one vinyl monomer (a) selected from the group consisting of a vinyl monomer represented by (wherein R 1 represents a hydrogen atom or a lower alkyl group having 1 to 3 carbon atoms and n is an integer of 1 to 8) and salts thereof; Polymer (B) obtained by polymerizing one or more vinyl monomers (c) in the presence of a polymer (A) prepared by polymerizing one or more vinyl monomers (b) copolymerizable with this vinyl monomer component (a), In the cationic polymer (C) obtained by Hoffman decomposition at alkaline pH, one or both of the vinyl monomers (b) and (c) are monomers having an amide group, and the cationic polymer according to the present invention is The cationic polymer is very useful as a strength enhancer or drainage aid, because it can show excellent effects on the water-free property and the Z-axis strength, and can improve the strength increase. |