| 摘要 |
PROBLEM TO BE SOLVED: To considerably improve corrosion resistance while maintaining high magnetic characteristics even when magnetic powder turned into fine particles is used by attracting p-benzoquinone having a specified structure to ferromagnetic powder having a specified particle diameter in a magnetic layer having a specified thickness. SOLUTION: A magnetic coating material is prepd. by attracting p- benzoquinone represented by formula I to ferromagnetic powder having 0.05-0.2μm particle diameter and adding a binder to the powder, and a magnetic layer having 0.1-2μm thickness is formed on a substrate by coating with the coating material to produce the objective magnetic recording medium. When magnetic powder is turned into fine particles while thinning an oxidized coating film, the deterioration of corrosion resistance begins from <=0.2μm particle diameter of the magnetic powder and is remarkable in the case of <=0.15μm. The particle diameter of the p-benzoquinone as a functional material is therefore regulated to <=0.2μm, preferably <=0.15μm. |
