| 摘要 |
PURPOSE:To improve recording and reproducing characteristics by forming a magnetic layer contg. the magnetic powder of which the surfaces are covered with a trisaturated fatty acid ester of anhydrosorbitol and a phosphate as well as a binder and a hardener. CONSTITUTION:The magnetic powder of which the surfaces are covered by adding 100pst.wt. magnetic powder to a methyl ethyl ketone soln. of 0.2-20pts.wt. a trisaturated fatty acid ester of anhydrosorbitol and 0.5-3pts.wt. a phosphate consisting of an alkoxylated higher alcohol or alkyl phenol, and adsorbing both of the above-described esters to the surface of the magnetic powders then taking out the magnetic powder and drying the same is prepd. The magnetic coating consisting of adding about 30pts. a binder resin (an urethane prepolymer and a vinyl chloridevinyl acetate copolymer, etc.) and about 9pts. hardener to this 100pts. covered magnetic powder is prepd. and this coating is coated on a substrate then dried, whereby the magnetic recording medium is obtained. In this way, the superior tape which is low in coefft. of dynamic friction, and does not cause degradation of characteristics owing to peeling of the magnetic powder and sticking on magnetic heads is obtained. |
