Surface sizing agent for papermaking

Abstract

To provide a surface sizing agent for papermaking, which has good low foamability and mechanical stability and has an excellent sizing effect. The surface sizing agent for papermaking is a surface sizing agent for papermaking, comprising a composition obtained by polymerizing unsaturated monomers in the presence of a starch, wherein the amount of the starch is 25 to 40 mass % based on the total amount of the starch and the unsaturated monomers, the unsaturated monomers comprise at least a styrenic compound and a (meth)acrylic ester compound, and the amount of the styrenic compound is 10 mass % or more and less than 30 mass %, and the amount of the (meth)acrylic ester compound is 20 to 50 mass %, based on the total amount of the starch and the unsaturated monomers.

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