| 摘要 |
PURPOSE:To obtain a magnetic recording medium having lower light transmittance than a conventional magnetic recording medium by forming a magnetic recording layer contg. colored aluminum oxide besides powder of a ferromagnetic body and a binder as principal components on a nonmagnetic support. CONSTITUTION:Aluminum oxide used in this invention is corundum (alpha-Al2O3) contg. 0.01-4% one or more kinds of inorg. impurities such as Cr2O3, NiO, Fe3O4, V2O5 and TiO2. Corundum contg. Cr2O3 is known as ruby, and corundum contg. TiO2 as sapphire. Light absorbing power in a desired wavelength range can be provided in accordance with the kinds and the amount of inorg. additives in aluminum oxide, and high dispersibility peculiar to aluminum oxide is not deteriorated. Magnetic iron oxide powder, chromium dioxide powder or metallic magnetic powder is arbitrarily used as magnetic powder in a magnetic recording layer. |
