| 摘要 |
PURPOSE:To provide an oriented polyester film containing a poly(alkylene glycol) and a higher fatty acid (derivative) and/or higher aliphatic alcohol, having excellent flatness, slippery and abrasion resistance and suitable for magnetic recording medium. CONSTITUTION:The objective film having a surface tension of 50-85dyne/cm, surface roughness Ra of 0.002-0.025mum, preferably 0.005-0.017mum and a kinetic friction coefficient mud of 0.1-0.7, preferably 0.1-0.35 and containing 0.001-1% inner particles and/or inert particles having an average particle diameter of 0.1-3mum is produced by mixing 100pts.wt. of a polyester with (A) 0.005-2(wt)% poly(alkylene glycol) component having a molecular weight of 600-200,000 and (B) 0.005-2% one or more components selected from >=8C higher fatty acid (preferably >=33C synthetic monocarboxylic acid), its derivative (e.g. ester, metallic salt, amide, etc.) and higher aliphatic alcohol having a melting point of >=50 deg.C and drawing the obtained composition. |
