| 摘要 |
PURPOSE:To improve a cinching phenomenon, the wear of a back layer, the adhesion between a magnetic layer and the back layer, etc., by obtaining the back layer of a magnetic recording medium (tape) by dispersing the nonmagnetic powder into a specific binder. CONSTITUTION:A composition for a back layer is obtained by dispersing (D) nonmagnetic powder (such as CaCO3, carbon black, etc.) into a binder containing (A) 10-80wt% polyvinyl chloride-polyvinyl acetate copolymer, (B) about 90- 20wt% polyurethane and (C) 5-80wt% isocyanate compound per 100wt% total resin quantity. This composition is coated on the rear surface of a supporter (such as polyethylene terephthalate film) having a magnetic recording layer on the upper surface. Thus a back layer is obtained. |
