Patent ID: 9047904
Filing Date: 2015-06-02
Classification: G11B

Abstract:
1. A magnetic recording medium comprising a nonmagnetic layer comprising a nonmagnetic powder and a binder and a magnetic layer comprising a ferromagnetic powder and a binder in this order on a nonmagnetic support, wherein the nonmagnetic layer comprises organic acid A and organic acid B below, with an acid strength pKa(A) of organic acid A and an acid strength pKa(B) of organic acid B satisfying a relation of pKa(A)<pKa(B); organic acid A: an unsaturated bond-containing organic acid comprising one substituent selected from the group consisting of a carboxyl group and a phosphoric acid group per molecule in which the unsaturated bond is included in an aromatic heterocyclic ring selected from the group consisting of the following three aromatic heterocyclic rings: organic acid B: an aliphatic or alicyclic organic acid in which two or more substituents substituted onto adjacent carbon atoms within the molecule are present per molecule, and at least one of the substituents is a carboxyl group.