BINDER FOR NONAQUEOUS SECONDARY BATTERY POROUS FILM, COMPOSITION FOR NONAQUEOUS SECONDARY BATTERY POROUS FILM, POROUS FILM FOR NONAQUEOUS SECONDARY BATTERY, AND NONAQUEOUS SECONDARY BATTERY

摘要

PROBLEM TO BE SOLVED: To provide a binder for a nonaqueous secondary battery porous film, which enables the formation of a porous film superior in endurance and enables the increase in stability of a composition for a porous film under a high shear condition.SOLUTION: A binder for a nonaqueous secondary battery porous film comprises: a particulate polymer; and a sulfonate compound. The particulate polymer is a random copolymer including 35 mass% or more of (meth)acrylic acid alkyl ester monomer units, and 20-65 mass% of aromatic monovinyl monomer units. A value determined by dividing a blend amount of the sulfonate compound by a blend amount of the particulate polymer is 0.005 or larger.SELECTED DRAWING: None