| 摘要 |
PURPOSE:To eliminate transfer from a back layer to a magnetic layer by depositing the magnetic layer which consists of specific ferromagnetic alloy powder dispersed in a resin binder and has specific coercive force and surface roughness on a base and forming the back layer consisting of a radiation-sensitive resin on the rear of the base. CONSTITUTION:A magnetic layer which contains magnetic alloy powder having >=48m<2>/g specific surface area by the BET method and has <=0.08mum surface roughness and >=1,000Oe coercive force is coated on a base. A back layer which consists of a radiation-curing type resin and is dispersed with a prescribed filler if necessary, is formed on the rear of such base. Co, Fe-Co, Fe-Co-Ni and Co-Ni are used for the magnetic alloy having the above-mentioned characteristics and pulverous powder consisting of said alloys added with Cr, Al, Si, etc. is used. The alloys are obtd. by a method of reducing metallic salts with a reducing agent such as BH4 by a wet process, etc. and have 2,000-3,000Gauss residual magnetic flux density Br. The radiation-curing resin used for the back layer is a resin having acrylic double bond, maleic double bond which have radiation- curable double bond. |
