| 摘要 |
PURPOSE:To obtain the subject film having a specific plane orientation degree, containing specific amounts of aluminum oxide particles, etc., and calcium carbonate particles, etc., having excellent slittability and abrasion resistance and useful as a base film for magnetic recording medium. CONSTITUTION:A polyester produced by reacting naphthalene-2,6-dicarboxylic acid, etc., as main acid components with ethylene glycol as main glycol component is used as a raw material for the objective film. The film having a plane orientation degree of 0.255-0.28 is produced by compounding the polyester with (A) 0.02-1.0wt.% of silicon oxide and aluminum oxide particles having an average particle size of 0.03-0.2mum and consisting of agglomerate of primary particles having an average particle size of 0.005-0.08mum and (B) 0.005-0.3wt.% of crosslinked polymer particles or calcium carbonate particles having an average particle size of 0.2-0.8mum. |
