| 摘要 |
PROBLEM TO BE SOLVED: To provide a binder for nonaqueous secondary battery porous film capable of forming a porous film excellent in durability, and enhancing stability of a composition for porous film under high shear.SOLUTION: In a binder for nonaqueous secondary battery porous film containing particulate polymer, the particulate polymer is a random copolymer containing 35 mass% or more of (meth)acrylic acid alkyl ester monomer unit, and 30-65 mass% of aromatic mono vinyl monomer unit, and the degree of swelling of the particulate polymer to a nonaqueous electrolyte is over one time and equal to or less than two times. |
