| 摘要 |
PURPOSE:To obtain a magnetic recording medium for high-density recording by forming a magnetic layer which contains specific barium ferrite magnetic powder, gamma-Fe2O3 having nearly the same grain size, etc., and contains said barium ferrite by >=50% on the basis of the whole magnetic powder. CONSTITUTION:Magnetic powder is obtained by uniformly dispersing 45pts.wt. barium ferrite magnetic powder 45, shown by the general formula, having >= 600-1,500 Oe coercive force and <=0.3mum mean grain size and 35pts.wt. gamma-Fe2O3 or Co magnetic powder having <=0.4mum grain size. This is dispersed in a ketone or toluene solution of a vinyl chloride-vinyl acetate copolymer to prepare a magnetic paint, with which a polyethylene terephthalate film is coated and dried to obtain a magnetic film. Using this magnetic film obtains high output over the entire frequency range from the audio band to the video band which can not be obtained by the used of magnetic powder as a simple substance. |
