The production mannered null alkyl ketene dimer of the surface size medicine, and its

摘要

PROBLEM TO BE SOLVED: To provide a two-pack surface sizing agent composed of an alkylketene dimer (AKD) emulsion and a water-soluble copolymer and having excellent storage stability, sizing performance, etc.;SOLUTION: The surface sizing agent is produced by mixing an AKD emulsion having a ζ-potential of -5 to +20 mV with a water-soluble copolymer having an acid value of 150-350 mgKOH/g. The AKD emulsion is obtained by emulsifying AKD in water with a cationic polymer compound and contains a water-soluble metal salt, and the water-soluble copolymer is produced by reacting a hydrophobic monomer with an anionic monomer containing a carboxylic acid group. Since the agent is a particular AKD emulsion containing the water-soluble metal salt and having suppressed cationic charge by a specific ζ-potential, it has good compatibility with the water-soluble copolymer and excellent storage stability. The problem of the water-soluble copolymer comprising the poor developability of the sizing performance in neutral paper, etc., is solved by the use of AKD to improve the sizing performance of neutral to acidic papers. It does not lower the friction coefficient of a coated paper.;COPYRIGHT: (C)2003,JPO