| abstract |
In order to propose a laminated porous film having both a shut-off (SD) characteristic in which a hole is reliably occluded and a high break-down (BD) characteristic, a porous membrane layer (A layer) other than a nonwoven fabric having a film thickness of 10 µm or more and a fiber diameter The film after heating with the air permeability (AP2) of the film before it is heated by heating for a predetermined time in the oven which consists of at least 2 layer of this 1 micrometer or less nonwoven fabric layer (B layer), and heated at predetermined temperature, and In the heating test for measuring the air permeability (AP1), the value of the ratio between the air permeability (AP1) and the air permeability (AP2) before heating (AP1 / AP2) when heated for 3 minutes at a heating temperature of 150 ° C to 200 ° C. ) The laminated porous film which is 10 or more at any heating temperature of 150 degreeC-200 degreeC is proposed.n n n Laminated porous film, air permeability, porous membrane layer, nonwoven fabric layer, battery separator |