| 摘要 |
PURPOSE:To obtain the superior dispersibility of magnetic powder, to increase durability, and to decrease surface electric resistance by adding sulfone modified polyester resin and a partially sulfonated styrene polymer as binder components for a magnetic layer. CONSTITUTION:As binder components for a magnetic layer, polyester resin having sulfonic acid and metallic sulfonate base in a molecule and a polystyrene or styrene copolymer having similar groups in a molecule are added. The sulfonic acid and metallic sulfonate base introduced in the molecule conributes to the improvement of the dispersibility of magnetic powder, its content is normally 10mol% per 100mol styrene composing a molecular skeleton and favorably 0.05- 3.0mol%, and the rate of a partially sulfonated styrene polymer in use is normally 90-1wt% of the total amount of sulfone modified polyester resin, and preferably 40-5wt%. |
