| 摘要 |
PURPOSE:To provide a magnetic recording medium which has good dispersibility of fillers and low viscosity of a coating compd. and obviates the dehydrochlorination by lapse of time and heating by providing a layer contg. a PVC resin contg. a sulfonic acid group and/or sulfonate residue and epoxy group and polyurethane resin having <=60,000wt average mol.wt. CONSTITUTION:This magnetic recording medium has the layer contg. the PVC resin contg. 0.5-4wt% sulfonic acid group and/or sulfonate residue and 0.5-3wt% epoxy group and the polyurethane resin having <=60,000wt average mol.wt. More specifically, the sulfonic acid and sulfonate residue is particularly effective to improve the dispersibility of magnetic powder and the adequate content thereof is 0.5-4wt%. the introduction of the epoxy group into the resin is effective to suppress the generation of the dehydrochlorination by heating or lapse of time and the adequate content thereof is 0.5-3wt% in terms of Tg of the resin, solubility, etc. The dispersibility is improved and the viscosity of the coating compd. is decreased if the polyurethane resin having <=60,000mol. wt. is used for blending.
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