| 摘要 |
<p>Provided is a separator for batteries, which uses a laminated porous film that exhibits high heat resistance, while having a microporous structure for providing high air permeability and electrolyte solution diffusion/retention function. The separator for batteries is characterized by having at least two layers, namely a layer (I) that is mainly composed of a polypropylene resin and a layer (II) that is composed of a resin composition which contains a polypropylene resin and a filler, and by having beta activity. The separator for batteries is also characterized in that the content of the filler contained in the layer (II) is from 20% by mass to 80% by mass (inclusive) relative to 100% by mass of the resin composition.</p> |
