| 摘要 |
PROBLEM TO BE SOLVED: To provide an additive and a method for paper making that are excellent in fixation of a neutral sizing agent, suppression of a pitch trouble, and improvement in freeness and squeezing property in a papermaking process under a neutral papermaking condition.SOLUTION: The additive for papermaking is a water-soluble polymer dispersion (D) including the following (A) to (C) and exerts an excellent effect on fixation of a neutral sizing agent, suppression of a pitch trouble, and improvement in freeness and squeezing property by adding the additive to a raw material before papermaking. The water-soluble polymer dispersion (D) includes: (A) at least one kind of water-soluble polymer fine particles selected from cationic, amphoteric and nonionic water-soluble polymer fine particles; (B) 30 to 300 mass% of a reaction product obtained by reacting an amine with an epihalohydrin or/and derivative thereof with respect to the water-soluble polymer fine particles; and (C) 1.0 to 35 mass% of an inorganic salt with respect to the water-soluble polymer dispersion (D). |
