Biaxially stretched polypropylene film, metallized film and film capacitor

摘要

A biaxially stretched polypropylene film includes protrusions on both surfaces, in which the biaxially stretched polypropylene film has a thickness t1 of 1 μm to 3 μm, 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 Pmin of 100 nm or greater and a maximum protrusion height Pmax of 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≦Pa250-450/Pa≦1.0 (1), 0.5≦Pb450-1600/Pb≦1.0 (2), and 600≦Pa+Pb≦1,200 (3).

主权项

1. A biaxially stretched polypropylene film comprising protrusions on both surfaces, and having a thickness t1 of 1 μm to 3 μm, a tensile strength in a machine direction of 120 MPa to 250 MPa, a tensile strength in a transverse direction of 250 MPa to 400 MPa, a minimum protrusion height Pmin of 100 nm or greater and a maximum protrusion height Pmax of 1,600 nm or smaller for either surface, and satisfying all of Formulae (1) to (3) when one of the surfaces is surface A and another is surface B:
0.5≦Pa250-450/Pa≦1.0  (1) 0.5≦Pb450-1600/Pb≦1.0  (2) 600≦Pa+Pb≦1,200  (3) in Formulae (1) to (3), Pa250-450 is a number of protrusions with a height of not smaller than 250 nm and smaller than 450 nm per 0.1 mm2 on surface A, Pb450-1600 is a number of protrusions with a height of not smaller than 450 nm and smaller than 1600 nm per 0.1 mm2 on surface B, Pa is a number of protrusions per 0.1 mm2 on surface A, and Pb is a number of protrusions per 0.1 mm2 on surface B.