| 摘要 |
<p>Provided are a wet paper strengthening agent which has a high solid content, exhibits excellent storage stability and exhibits an excellent wet paper strength improvement effect, and a paper that contains this wet paper strengthening agent. This wet paper strengthening agent is characterized by containing (A) a polyamide-polyamine-epihalohydrin resin, which is obtained by reacting specified proportions of an epihalohydrin and a polyamide-polyamine obtained by reacting a polyalkylene polyamine with a dibasic carboxylic acid or (B) a polyamide-polyamine-polyurea-epihalohydrin resin, which is obtained by reacting specified proportions of an epihalohydrin and a polyamide-polyamine-polyurea obtained by reacting specified proportions of a polyalkylene polyamine, a dibasic carboxylic acid and a urea compound, and is also characterized by having a specified intrinsic viscosity, a specified Huggins constant, a specified degree of cationization, a specified weight average molecular weight, and a specified proportion of components having a weight average molecular weight of 5000 or higher.</p> |
