| 摘要 |
PURPOSE:To obtain a magnetic recording medium having improved durability, electromagnetic conversion characteristic, surface characteristic, etc. by incorporating a specific polymer prepd. by introducing a hydrophilic group into a copolymer of VC-vinyl acetate-VA, etc. as a binder together with magnetic powder in a magnetic layer. CONSTITUTION:A magnetic coating contg. the compd. obtd. by bringing a compd. expressed by Cl-X, Cl-Y into reaction with the VC-vinyl acetate-VA copolymer expressed by the formula I (X is H or a group expressed by th formula II, Y is a group expressed by the formulas III-VI, Z is -CH3 or -CH2CH3, R1, R2 are H, 1-6C hydrocarbon, R3 is 1-17C hydrocarbon, R4, R5 are 3-17C hydrocarbon, m, n, p are respectively 0-3, (i) is 200-800, (j) is 0-200, (k) is 1-200, where k+l is <=200) as a binder together with an urethane resin, and contg. magnetic powder and a necessary additive such as pigment, abrasive or the like is prepd. A magnetic layer is formed by using such coating, and a magnetic recording medium which has good dispersibility of magnetic powder, is free from dislodging of powder, etc., and has an excellent running characteristic, video characteristic etc. is obtd. |
