| 摘要 |
PURPOSE:To improve a square ratio, wear resistance and secular stability by using specific dialkylsulfosuccinate as a treating agent and by treating ferromagnetic powder in a medium including a high-polar hydrophilic organic solvent having more than specific values of dielectric constant and solubility to water. CONSTITUTION:As a treating agent, 0.5-10wt% dialkylsulfosuccinate expressed by the equation [R1 and R2 for CnH2n+1, (n) for 5-20, and M for Na and K] is used for ferromagnetic powder. This and a high-polar hydrophilic organic solvent (methanol, glycol, etc.) of four or more in dielectric constant and 50g or more in solubility to 100g water at 20 deg.C are included in a treating medium by 5% or more. For example, ferromagnetic powder is kneaded in a solution obtained by adding the above-mentioned treating agent and high-polar solvent to a mixture of methyl ethyl ketone and toluene equal in weight as the treating medium and then additives for magnetic ink such as a binder, lubricant are added to manufacture magnetic ink. |
