| 摘要 |
PURPOSE:To obtain a recording medium having improved recording characteristics and durability by providing a magnetic layer dispersed with the magnetic powder adsorbed with a monomer and polymer having a vinyl group, ethylene oxide addition group and phosphoric acid radical in molecular structure on the surface in a binder. CONSTITUTION:The magnetic powder produced by mixing phosphate monomer of the compd. expressed by the formula (Y is H or CH3, n=1-50), a polymn. catalyst and magnetic powder, and filtering the same by passing the mixture through a filter of about 20mu pore size is dried in a constant temp. dryer kept at 100 deg.C to polymerize the above-described monomer, whereby the magnetic powder contg. also the unpolymerized monomer is obtd. The coating liquid prepd. by dispersing such magnetic powder in a binder resin soln. is coated on a substrate such as polyester film, and the surface is smoothed with calender rolls, whereby a magnetic recording medium is obtd. The coating magnetic powder is dispersed uniformly in the binder and the excellent recording characteristics and durability are obtd. |
