The porous polypropylene film exhibits extremely excellent uniformity of film-widthwise thermal dimensional change.

Provided is a porous polypropylene film having excellent safety and low air permeation resistance.

Provided is a porous polypropylene film that has both air permeability and piercing strength.

Disclosed is a porous polypropylene film characterized in that the air permeability change rate is low even in a high temperature environment and the initial air permeability is excellent.

The porous polypropylene film exhibits extremely excellent uniformity of film-widthwise thermal dimensional change.

Provided is a porous polypropylene film having excellent safety and low air permeation resistance.

Provided is a porous polypropylene film that has both air permeability and piercing strength.

In the illustrated embodiment, the separator was formed of porous polypropylene.

A film for thermal porous printing paper and a thermal porous printing paper composed of the film and a porous support are disclosed.

Proposed is a porous polypropylene resin film which comprises a polypropylene-based resin as the main component and in which the coefficient of static friction between the films is higher than that between the film and SUS.

When used as a cell separator, the porous polypropylene resin film exhibits excellent slipperiness and workability.

The polypropylene for a film capacitor and the polypropylene sheet for a film capacitor are suitable for a polypropylene film for a film capacitor and a film capacitor comprising the film.

Also disclosed is a multilayer porous film obtained by arranging the porous film and another porous film containing a thermoplastic resin in layers.

The hydrophobic material may be microporous polyethylene, polypropylene, or polytetrafluoroethylene.

Provided are a porous polypropylene film with excellent productivity, air permeability, mechanical properties, and heat resistance, and an electrical storage device.