| 摘要 |
PURPOSE:To improve dispersibility and productivity by incorporating a compd. which is obtd. from the reaction of the three; a specific compd., aliphat. polyol and di- or triisocyanate and has the carboxy group or carboxy group salt bound on the tertiary carbon into a magnetic layer. CONSTITUTION:The magnetic recording medium provided with the magnetic layer contg. magnetic powder and binder on a base contains the magnetic layer which is obtd. by the reaction of at least the three; the compd. expressed by the formula I, the aliphat. polyol and the di- or triisocyanate and has the carboxy group or carboxy group salt bound on the tertiary carbon in the magnetic layer. In the formula I, R1 and R2 are a bivalent residual hydrocarbon group, R3 is a monovalent residual hydrocarbon group, X1 and X2 are a group reactive with the isocyanate and M denotes a hydrogen atom, alkaline metal atom or alkaline earth metal atom. The magnetic recording medium which has the high output and high S/N and has the magnetic layer formed by using the magnetic coating compd. having the good stagnation stability, hence good productivity is thus obtd.
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