| 摘要 |
PURPOSE:To obtain a magnetic recording medium which has the substantially improved effect of preventing electrostatic charge and has excellent durability, squareness ratio and sensitivity by crosslinking the functional group on the surface of carbon black particles and the functional group of a binder resin by a polyisocyanate having a low mol.wt. thereby providing the structure arrangement to pulverous needle-like magnetic powder. CONSTITUTION:The structure for the pulverous needle-like magnetic particles or powder can be formed by the use of a slight amt. of carbon black if the functional group on the surface of the carbon particles is preliminarily bronded chemically with the functional group of the binder resin by the polyisocyanate having the low mol.wt. and therefore the electric resistance of a coated film can be decreased down to about 10<3>OMEGA and the dispersibility can be improved. The uniformity, etc. of the coated film is thereby assured and the durability, sensitivity and squareness ratio are improved.
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