Kabushiki Kaisha Toshiba

Konica Corporation

Tokyo Shibaura Denki Kabushiki Kaisha

Toshio Fukaya

Hajime Takeuchi

Takeo Ito

Seiichi Tobisawa

Toshihiko Oguchi

Minoru Hashimoto

Masumi Koishi

Masahiko Yotuyanagi

Ken-ichi Furuhata

A magnetic recording medium comprises a non-magnetic base material; a lower magnetic layer containing a magnetic powder for recording in a long wavelength range and a resin binder; an upper magnetic layer containing a magnetic powder for recording in a short wavelength range and a resin binder; and an intermediate layer disposed between the two magnetic layers. By properly selecting the type and amount of resin binder contained in the upper magnetic layer and by disposing the intermediate layer whose main component is a resin binder, dispersion property of the magnetic powder in the upper magnetic layer can highly be improved, and thin and smooth magnetic layers can be obtained. Thus, the recording medium provides excellent reproduction characteristics in the wide wavelength range and has excellent running durability. In particular, the reproduction characteristics in a short wavelength range can be improved. A hexagonal ferrite powder is suitably used as the magnetic powder for recording in the short wavelength range. As the resin binder for the intermediate layer, a polyisocyanate compound whose molecular weight is 1,000 or less is particularly effective.

Magnetic records medium having multiple magnetic layers for recording in

A method of manufacturing a magnetic recording medium has a step of mechanically pulverizing and mixing a composition of a binder consisting of a solid resin and a magnetic powder so as to form a mixed powder. The method allows mass-production of magnetic recording media having excellent outputs and S/N ratios.

Method of manufacturing magnetic recording medium

There is disclosed a method of making a solar energy collector element which comprises the step of forming a carbon containing film on at least the sunlight receiving surface of a substrate which is made of an iron metal material, and then heat-treating at least the sunlight receiving surface in an oxidizing atmosphere. The solar energy collector element made by the method of the present invention is superior in selective absorption characteristics for the solar energy and inexpensive in manufacturing.

Method of making a solar energy collector element

Growing community of inventors

Yokohama, Japan

Toshio Fukaya