MAGNETIC RECORDING MEDIUM WITH REAR-SIDE COATING CONTAINING POLYMER PARTICLES

摘要

PROBLEM TO BE SOLVED: To increase the travel durability by incorporating nonmagnetic particles of specific composition, dispersed in a polymer binder, in the reverse- side coating. SOLUTION: The magnetic recording medium has a magnetic layer on one major surface of a base which have two major surfaces and the reverse-side coating on the other major surface. This reverse-side coating contains the inorganic nonmagnetic particles dispelled in polymer binder. the particles contain at least one kind of polymerizing di(meta)acryalte monomer expressed by the formula by about 50 pts.wt. and at least one kind of polymerizing hydroxyl containing monomer by about 2-50 pts.wt. In the formal, R4 is independently H or CH3 and X is a bivalent branch or nonbranch fatty acid or aromatic combination group. Thus, the polymer particles are used in the reverse-side coating to obtain improved tape tension, improved air bleeding characteristics, and improved cleaning property.