| 摘要 |
PURPOSE:To obtain a polyester film which is resistant to shaving and scratch and suitable for a magnetic recording medium by compounding a polyester with specific fine platy particles of aluminum oxide. CONSTITUTION:This polyester film for a magnetic recording medium is obtd. by compounding a polyester with 0. 05-2.0wt.% platy aluminum oxide particles having thicknesses of 0.25mum or lower and a mean plate size of 0.05-3mum as the lubricant. The shaving resistance of the film is improved by using the aluminum oxide particles which contain particles having an aspect ratio of 2-20%, pref. 5-15%, in an amt. of 50% or higher, pref. 80% or higher (based on the number of particles). Esp. pref. examples of the polyester are polyethylene terephthalate and polyethylene 2, 6-naphthalenedicarboxylate. Thus, obtd. film exhibits good shaving and scratch resistances to a coarse guide in a cassette. |
