| 摘要 |
PURPOSE:To obtain sufficient wear resistance and electromagnetic conversion characteristic by coating a magnetic coating compd. prepd. by subjecting the same to primary dispersion with a polyurethane resin into which a hydrophilic group is introduced, then to secondary dispersion with a vinyl chloride resin on a nonmagnetic base, thereby forming a magnetic layer. CONSTITUTION:The amt. of the polyurethane resin to be adsorbed can be increased to the amt. of the vinyl chloride resin to be adsorbed or above by introducing the hydrophilic group into the molecules of said resin. The secure adsorption of the polyurethane resin having the wear resistance better than the wear resistance of the vinyl chloride resin to the magnetic powder is, therefore, permitted by the hydrophilic group in the molecules. The better durability is thus obtd. with the magnetic coated film formed by the primary dispersion with the polyurethane resin having the hydrophilic group and the secondary dispersion with the vinyl chloride resin than the magnetic coated film obtd. by the reverse sequence.
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