Magnetic recording medium

Abstract

The magnetic recording medium according to the invention contains as a binder a modified polymer prepared by graft polymerizing with a polymerizable unsaturated compound having a sulfonic group or a metal sulfonate group onto a polymer through irradiation. The modified polymer provides a good binding of magnetic powder because of the presence of the sulfonic group or the metal sulfonate group and improves the dispersibility and packing properties of the magnetic powder. The magnetic recording medium thus shows excellent durability. Further, since the modified polymer can be produced by graft polymerization utilizing irradiation, the kind of polymer which may be used in the method of manufacturing the magnetic recording medium according to the invention extends over such a wide range that the magnetic recording medium may be manufactured by an industrially practical process.

Dependencies are inferred from the claim text.