| 摘要 |
PURPOSE:To prevent stripping-off of a magnetic layer and to improve durability by using an aliphat. hydrocarbon having a branch and number of carbon atoms in a specific range as a solvent and performing surface treatment. CONSTITUTION:A surface treatment is performed by using an aliphat. hydrocarbon having a branch and 6-9C as a solvent. The surface treatment can be performed by using a lubricant such as higher fatty acid, higher alcohol, fatty acid ester or the like as a surface treating agent. An aliphat. hydrocarbon having a branch and 6-9C is used as the solvent for the surface treating agent. If the number of carbon atom is >9, the b.p. increases and the removal of the solvent by evaporation is difficult. If the number of carbon atom is <6, the solvent is gas at an ordinary temp. or the b.p. is too small to utilize as the solvent, The straight chain aliphat. hydrocarbon having no branch gives a damage on the metallic magnetic layer and is therefore undesirable. |
