| 摘要 |
<p>PROBLEM TO BE SOLVED: To ensure superior wettability and dispersion stability of a pigment by incorporating a substrate with a magnetic coating contg. a two-phase star block copolymer having pendant dispersible groups on the surface. SOLUTION: This magnetic recording medium contains a polymer binder made of a star block copolymer presented by the formula (A-B)m -X, wherein X is a multifunctional coupling part, (A-B)'s are polymer bonding radicals extending radially from the part X, (m) is at least 3 on average, A is a rigid glassy polymer segment, B is a flexible rubberlike polymer segment and the segment A is not compatible with the segment B.</p> |
