| 摘要 |
PROBLEM TO BE SOLVED: To provide an emulsion sizing agent for paper making having less production of an aggregate by interaction with cationic substances such as calcium existing in a papermaking system, having stability of pH and hardness of water for papermaking in a wide range, and excellent in sizing property.SOLUTION: An emulsion sizing agent is provided as a dispersion prepared from a dehydration condensate (A), obtained by a dehydration condensation of a trivalent or tetravalent carboxylic acid (a1) and at least one kind of compound (a2) selected from a group consisting of monovalent aliphatic alcohol (a2-1) having an alkyl group or an alkenyl group having 6 to 22 carbon atoms and aliphatic amine (a2-2) having an alkyl group and/or an alkenyl group having 6 to 22 carbon atoms, by using, as a dispersant, (meth)acryl amide-based copolymer (B) obtained by polymerizing a monomer containing (meth)acryl amide (b1) of 50 to 90 mol%, a carboxyl group-containing monomer (b2) of 2 to 40 mol%, a sulfo group-containing monomer (b3) of 0.1 to 10 mol% and a hydrophobic monomer (b4) of 2 to 30 mol%. |
