abstract |
A particulate polymer for a binder of a lithium ion secondary battery, wherein ion conductivity of a film formed by the particulate polymer after being immersed in an electrolytic solution at 60° C. for 72 hours is 1×10 −5 S/cm to 1×10 3 S/cm, and tensile strength of the film is 500 N/cm 2 to 4000 N/cm 2 . |