Magnetic recording medium

Abstract

Abstract PURPOSE:To sufficiently suppress the swelling or dissolving by the solvent in a magnetic coating compd. by providing a under coating layer contg. specific components at specific ratios between a nonmagnetic base and a magnetic layer. CONSTITUTION:The under coating layer to be provided between the nonmagnetic base and the magnetic layer is formed of the components such as >=2 kinds of resins A selected from the group consisting of a polyester resin having a hydroxyl group and polyurethane resin having a hydroxyl group, a polyisocyanate compd. B, 1 or >=2 kinds of compds. C selected from an org. metal compd. and tertiary amine compd., and carbon black D having <=50mmu average particle size and <=100gDBP/100g oil absorption, etc. The swelling or dissolving by the solvent in the magnetic coating compd. is sufficiently suppressed and the magnetic recording medium having good surface characteristics and high durability is obtd. if the content ratio of the resin A and the carbon black D is specified to 30/70-70/30 ratio by weight, the content ratio of the compd. B to the resin A to 15-50wt.% and the content ratio of the compds. C to the resin A to 0.5-5wt.%.

Inventors

• 👤 Atsushi Suzuki
• 👤 Shigeru Koyama

Bibliographic Details