| abstract |
A biaxially oriented laminate film comprising a thermoplastic resin layer A and a thermoplastic resin layer B which is laminated on one side of the thermoplastic resin layer A. The surface of the thermoplastic resin layer A has protrusions having an average height of 2 to 85 nm and an average width of 20 to 500 mu m, at a density of 4 to 2,500/mm2. The thermoplastic resin layer B contains inert fine particles, and the surface of the thermoplastic resin layer B is rougher than the surface of the thermoplastic resin layer A. The laminate film can have furher a layer C on the thermoplastic resin layer A. The surface of the thermoplastic resin layer C has protrusions having an average height of 2 to 85 nm and an average width of 20 to 500 mu m, at a density of 4 to 2,500/mm2. These laminate film are useful as a base film for magnetic recording medium. |