Patent ID: 8211507

Claim:
A method for producing a thermoplastic resin film, comprising: providing a polyolefin-based thermoplastic resin film (i) which is a multi-layered resin film comprising a substrate layer (ii) and a surface layer (iii) formed over at least one face of the substrate layer (ii); oxidizing a surface of the polyolefin-based thermoplastic resin film (i); applying a surface modifier to the surface of the polyolefin-based thermoplastic resin film (i); and stretching the polyolefin-based thermoplastic resin film (i), wherein the substrate layer (ii) comprises from 40 to 99.5% by weight of a polyolefin-based thermoplastic resin and from 0.5 to 60% by weight of inorganic fine powder, the surface layer (iii) comprises an unsaturated carboxylic acid-modified polyolefin-based thermoplastic resin in an amount of 10% or more by weight, the surface layer (iii) is free from inorganic fine powder, and a degree of modification with an unsaturated carboxylic acid of the unsaturated carboxylic acid-modified polyolefin-based resin is from 0.01 to 10% by weight.