| abstract |
A porous substrate comprising a polyolefin resin as a main component; and a porous layer containing a polyvinylidene fluoride resin laminated on at least one surface of the porous substrate, wherein the porous substrate comprises diethyl carbonate And the spot diameter of the diethyl carbonate after 10 seconds dropped onto the porous substrate is 20 mm or more, and the reduction rate of the polyvinylidene fluoride resin in the polyvinylidene fluoride resin is from 15 to 20 seconds / A separator for a nonaqueous electrolyte secondary battery comprising a laminate characterized in that the content of the? -type crystal is 36 mol% or more when the sum of the contents of? -form crystals and? -form crystals is 100 mol% Can be suppressed. |