| abstract |
(57) [Problem] To provide a magnetic layer having high dispersibility and durability that can be used even under special use conditions. SOLUTION: A magnetic layer 2 is formed by copolymerization of a polyurethane resin having a urethane group concentration of 3 mmol / g or more and a vinyl group-containing compound as a binder, in which glycol and an aromatic diisocyanate are polymerized. And the glass transition temperature of the magnetic layer 2 is 100 ° C. or higher. |