Magnetic recording medium, non-magnetic acicular composite particels and process for producing the particles

摘要

A magnetic recording medium comprises: (i) a non-magnetic base film; (ii) a non-magnetic undercoat layer on the non-magnetic base film, comprising a binder resin and non-magnetic acicular composite particles having an average major axis diameter of 0.01 to 0.3 mu m and comprising: acicular hematite particles or acicular iron oxide hydroxide particles as non-magnetic core particles, a coating on said acicular hematite particles or acicular iron oxide hydroxide particles, comprising at least one organosilicon compound selected from: (1) organosilane compounds obtainable from alkoxysilane compounds, and (2) polysiloxanes or modified polysiloxanes, and a phthalocyanine-based pigment coat which is provided on said coating layer and which is present in an amount of from 1 to 100 parts by weight based on 100 parts by weight of said acicular hematite particles or acicular iron oxide hydroxide particles; and (iii) a magnetic recording layer on the non-magnetic undercoat layer, comprising magnetic particles and a binder resin.