| abstract |
The invention provides a surface sizing agent for paper making with good low foaming properties and mechanical stability, and excellent sizing effect. A surface sizing agent for papermaking, comprising a composition obtained by polymerizing unsaturated monomers in the presence of starch, whereinnThe starches are 25% to 40% by mass in the total of starches and unsaturated monomers,nThe unsaturated monomers include at least styrenes and (meth)acrylates, and in the total of starches and unsaturated monomers, the styrenes are 10% by mass or more and less than 30% by mass, and The (meth)acrylates are 20% by mass to 50% by mass. |