Toray Industries, Inc.

Teruo Monno

Masami Sugata

Tetsuya Asano

Takanori Nakatsuka

Masami Mizushima

A biaxially stretched polypropylene film includes protrusions on both surfaces, in which the biaxially stretched polypropylene film has a thickness t1 of 1 &#x3bc;m to 3 &#x3bc;m, has a tensile strength in the machine direction of 120 MPa to 250 MPa, has a tensile strength in the transverse direction of 250 MPa to 400 MPa, has a minimum protrusion height Pof 100 nm or greater and a maximum protrusion height Pof 1,600 nm or smaller for either surface, and satisfies all of Formulae (1) to (3) when one of the surfaces is surface A and the other is surface B: 0.5&#x2266;Pa/Pa&#x2266;1.0 (1), 0.5&#x2266;Pb/Pb&#x2266;1.0 (2), and 600&#x2266;Pa+Pb&#x2266;1,200 (3).

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Tsuchiura, Japan

Teruo Monno