| abstract |
The present invention provides a separator for a non-aqueous secondary battery having excellent heat resistance, shutdown characteristics, membrane resistance, and handling properties. The present invention provides a polyolefin microporous membrane for use in a separator for a non-aqueous secondary battery in which a heat-resistant porous layer is coated on at least one surface of a polyolefin microporous membrane to be integrated, (A) a film thickness of 5 to 20 µm, and (B). Porosity 35-50%, (C) Permeability per unit thickness (JIS P 8117) is 10-30 sec / 100 cc · μm, and permeability (JIS P 8117) of the entire membrane is 400 sec / 100 cc or less , (D) Y / X = 1 × 10 −3 when the air resistance (JIS P 8117) is X sec / 100 cc and the membrane resistance when the polyolefin microporous membrane is impregnated with an electrolyte solution is Y ohm · cm 2. To 1 × 10 −2 ohm · cm 2 / (second / 100 cc). |