Patent ID: 8529241

Claim:
A method for manufacturing a thermoplastic resin film by a melt-film forming method, comprising: extruding a thermoplastic resin melted by an extruder from a die as a sheet-like melted resin; nipping the sheet-like melted resin between a metallic elastic roller and a cooling roller; and cooling and solidifying the sheet-like melted resin on the cooling roller, wherein an arithmetic average height Ra of surfaces of the elastic roller and the cooling roller is not more than 100 nm, a periphery speed ratio (Vcd/Vtr) of a periphery speed Vtr of the elastic roller and a periphery speed Vcd of the cooling roller is 0.99 to 1.01, a difference (Tcd−Ttr) between a surface temperature Ttr of the elastic roller and a surface temperature Tcd of the cooling roller is 0.01° C. to 30° C., a maximum linear pressure which is applied to the sheet-like melted resin passing through a vicinity of a portion where a gap between the elastic roller and the cooling roller is narrowest when the sheet-like melted resin is nipped between the elastic roller and the cooling roller is 0.3 MPa to 3 MPa, wherein the metallic elastic roller includes a metallic shaft, a liquid medium layer covering over the metallic shaft and a metallic cylinder covering over the liquid medium layer and said metallic cylinder having a wall thickness of 1.5 mm to 5 mm, a surface temperature Ttr of the elastic roller is lower than a surface temperature Tcd of the cooling roller, and wherein retardation due to residual strain is not generated.