Laminated porous film, separator for lithium cell, and cell

A laminated porous film, comprising:

• a layer A comprising a polypropylene resin as a main component thereof;
• and
• a layer B comprising a polyethylene resin,
• wherein the laminated porous film has β activity, and
• wherein a ratio (HMD/HTD) of a tear strength (HMD) in a flow direction (MD) of the laminated porous film to a tear strength (HTD) in a direction (TD) vertical to the flow direction (MD) is 0.08 to 2.0.

A laminated porous film, comprising:

• a layer A comprising a polypropylene resin as a main component thereof;
• and
• a layer B comprising a polyethylene resin,
• wherein the laminated porous film has a β activity,
• wherein when the laminated porous film is heated at 105° C. for one hour in a direction (TD) vertical to a flow direction (MD) of the laminated porous film, a shrinkage factor STD2 is not more than 10%;
• and
• when the laminated porous film is heated at 105° C. for one hour in the flow direction (MD) and in the direction (TD) vertical to the flow direction, a ratio of a shrinkage factor SMD2 in the flow direction (MD) to a shrinkage factor STD2 in the direction (TD) vertical to the flow direction (MD) is 0.1 to 3.0.