| 摘要 |
PURPOSE:To obtain the title film excellent in gloss, adhesiveness, running performance at high temperature and high humidity and abrasion resistance, comprising a specified polyester copolymer composition. CONSTITUTION:A dicarboxylic acid is reacted with a diol in the presence of a polyfunctional organic compound having a 6C or higher long-chain alkyl group (e.g., 1,2-octanediol) and inert particles (e.g., CaCO3) of an average particle diameter of 0.08-5mu and 0.06-4wt.% organic particles to obtain a polyester copolymer composition having copolymerized repeating units having a 6C or higher long-chain alkyl group as a side chain. This composition is mixed with a polymer containing internal particles and a polymer containing no particles, and this mixture is molded into a sheet to obtain an unstretched film. This film is uniaxially or biaxially stretched at 70-130 deg.C and a stretch ratio of 2-5, heat-treated at 130-250 deg.C and subjected to corona discharge treatment with an applied electric energy of 5-70W.min per m<2> of the film to be treated to obtain a polyester film of which the surface roughness Ra on at least either surface is 0.005-0.09mum. |
