| 摘要 |
PURPOSE:To improve durability by making combination use of a specific urethane resin as a binder for a magnetic layer and specific higher fatty acid as a lubricating agent. CONSTITUTION:The polyurethane resin has the polyester polyol contg. >=50mol% alcohol residue of >=1 kinds selected from alicyclic dihydric alcohol and arom. dihydric alcohol as a alcohol component and/or >=50mol% acid residue of >=1 kinds selected from alicyclic dicarboxylic acid and arom. dicarboxylic acid as an acid component and >=1 kinds of the polyiocyanate selected from tolylene diisocyanate, diphenylmethane-4,4'-diisocyanate, etc., as the main skeleton. The polyurethane resin having >=5mol% ratio of the diisocyanate component to the sum of the total alcohol component and the total acid component is used as the binder component. The higher fatty acid of 12-22C is further used together at 0.1-4pts.wt. per 100pts.wt. CrO2. The running performance and durability are thereby improved and the long-period preservable property is improved. |
