| abstract |
(57) Abstract: The present invention is produced by reacting an acrylamide-based copolymer with a hypohalite under an alkaline range, The present invention relates to a cationic polyacrylamide and a paper strength enhancer and drainage improver for Z-axis paper strength and interlayer paper strength, each of which contains the cationic polyacrylamide as an active ingredient. (A) a group containing a carbamoyl group; Mol%, (b) 3 to 40 N, N'-dimethylamide groups. The acrylamide-based copolymer and the hypohalite, each containing at least one mol% of the acrylamide-based copolymer and the hypohalite, at a temperature (T) in the range of 50 to 110 ° C. within a short time (t) defined below at least under alkaline conditions of pH 11 or more. It is a cationic polyacrylamide obtained by performing a reaction. e 15,150 / (273 + T) × 2.5 × 10 −20 ≦ t (sec) ≦ e 15,150 / (273 + T) × 10 −18 +30 (T is the reaction temperature (° C.)) |