Vinyl alcohol copolymers containing cationic groups

摘要

A water-soluble cationic copolymer and methods for producing the same is disclosed which comprises comonomer units respectively represented by the formulae: (I) (II) wherein R1 is H or lower alkyl; B is R2, R3 and R4 are each independently lower alkyl or lower alkyl which contain a substituent; X is an anion capable of forming a salt with the ammonium nitrogen; and A is a group which links the nitrogen atom in B to the amide nitrogen atom. These copolymers are used in preparing paper strength additives.