Laminated porous film and non-aqueous electrolyte secondary cell

1. A laminated porous film, comprising:

a porous layer containing a polyolefin; and

a porous layer containing a heat-resistant material and provided on one or both surfaces of the porous layer containing the polyolefin,

the laminated porous film satisfying Formula (I) below,

0.1136×α+0.0819×β+3.8034≥4.40  (I),

where

α is a value of a film resistance (Ω·cm 2 ) of the laminated porous film, and

β is a value of a volume (cc/m 2 ) of the heat-resistant material contained per 1 m 2 of the porous layer containing the heat-resistant material,

wherein the value α is within a range of 0.25 Ω·cm 2 to 2.00 Ω·cm 2 ,

wherein the value β is within a range of 5 cc/m 2 to 10 cc/m 2 ,

wherein the porous layer containing the polyolefin has a thickness within a range of 5 μm to 30 μm,

wherein the porous layer containing the heat-resistant material has a thickness within a range of 1 μm to 20 μm,

wherein the laminated porous film has an air permeability within a range of 50 sec/100 cc to 2000 sec/100 cc,

wherein the heat resistant-material is contained at a proportion of more than 50% by volume based on an entire solid content of the porous layer,

wherein the heat-resistant material includes a binder and filler, the binder being a water-soluble polymer,

wherein the filler has a proportion of 20% by weight to 99% by weight with respect to the combined weight of the binder and the filler, and

wherein the filler is made of alumina.

2. The laminated porous film according to claim 1 ,

wherein

the laminated porous film satisfies Formula (I-2) below,

4.90≥0.1136×α+0.0819×β+3.8034≥4.40  (I-2).

3. A nonaqueous electrolyte secondary battery, comprising

a laminated porous film according to claim 1 .

4. The laminated porous film according to claim 1 , wherein the water-soluble polymer is a carboxy alkyl cellulose, an alkyl cellulose, a hydroxyalkyl cellulose, starch, polyvinyl alcohol, or sodium alginate.