Porous multi-layer film
AssigneeUbe Industries, Ltd.
InventorsHiroshi Kurauchi, Tetuo Akazawa, Akira Kawabata
Life of this patent
Estimating the term…
Abstract
A porous multi-layer film favorably employable as a separator film for a nonaqueous electric battery comprises at least three united polyolefin layers, in which at least one polyolefin layer is a polyethylene layer and at least one polyolefin layer is a polypropylene layer which is placed in contact with the polyethylene layer. The polyolefin layers are combined to form a united structure with a peel strength of at least 3 g/15 mm and has a pore volume of 30-80%, a maximum pore size of 0.02-2 .mu.m, a shutdown temperature of 135.degree.-140.degree. C., and a thermal durability to maintain the shutdown condition up to at least 180.degree. C.
Claims18
A porous multi-layer film comprising two polypropylene layers with a polyethylene layer sandwiched therebetween, said three layers being combined to form a united structure with a peel strength of at least 3 g/15 mm, which has a pore volume in the range of 30 to 80%, a maximum pore size in the range of 0.02 to 2 .mu.m, a gas permeability in the range of 150 to 1,500 in terms of Gurley Number, a shutdown temperature in the range of 135.degree. to 140.degree. C., and a thermal durability to maintain the shutdown condition up to at least 180.degree. C.
Dependencies are inferred from the claim text.