Patent ID: 6824867
Filing Date: 2004-11-30
Classification: B82Y,C01P,C09C,G11B,Y10T

Abstract:
A non-magnetic substrate for magnetic recording medium, comprising:a base film; and a non-magnetic undercoat layer formed on said base film, comprising a binder resin and non-magnetic composite particles having an average particle size of 0.01 to 0.3 &mgr;m, the non-magnetic composite particles comprising: non-magnetic particles as core particles; and inorganic fine particles having an average particle size of 0.001 to 0.07 &mgr;m, which are present on the surface of each non-magnetic particle, and consist of at least one inorganic compound selected from the group consisting of oxides, nitrides, carbides and sulfides of an element selected from the group consisting of an aluminum element, zirconium element, cerium element, titanium element, silicon element, boron element and molybdenum element, said inorganic fine particles being fixed or anchored on the surface of each non-magnetic particle through a silicon compound derived from tetraalkoxysilanes and the amount of said inorganic fine particles being 0.1 to 20% by weight based on the weight of said non-magnetic particles.