Tdk Electronics Company, Limited

Tdk Corporation

Fujio Shibata

Hiroshi Kawahara

Hitoshi Azegami

Shinji Umeki

Kiyotaka Okuyama

Kazuo Takada

Kenji Hirabayashi

Chiho Mikura

Chihoto Mikura

A magnetic recording medium, comprising a magnetic layer and a non-magnetic substrate therefor, which magnetic layer is formed by dispersing magnetic powder in a vehicle formed of a copolymer containing vinyl chloride, another monomer copolymerizable with said vinyl chloride, a vinyl ester of an alkanoic acid and a saponification product thereof and having an OH/CH absorption ratio of 0.2 to 0.7 in the infrared absorption spectrum, and a rubbery binder.

Magnetic recording medium

A magnetic recording medium obtained by kneading ferromagnetic particles with a binder composition and coating on a non-magnetic substrate, which is characterized by that the binder composition comprises a copolymer comprising 80-89% of vinyl chloride, 5-10% of vinyl acetate and 6-10% of vinyl alcohol and a polyurethane elastomer.

High density magnetic recording medium

A magnetic recording medium comprised of a nonmagnetic base and a magnetic coating layer thereon, said magnetic coating layer comprises ferromagnetic particles dispersed in a binder vehicle, characterized in that said magnetic coating layer contains a glyceride and a sorbitan ester of fatty acid.

A magnetic recording medium, having formed on the surface of a non-magnetic substrate, a layer of the dispersion in a binder vehicle of magnetic particles having the surface thereof coated with a polyaminoamide phosphate.

Magnetic recording medium and method of manufacture

A magnetic recording tape or disc which has excellent physical characteristics of adhesive strength, a repeated running durability, and a gloss degree of the surface as well as excellent electromagnetic characteristics. A binder of a magnetic paint coating comprises 30 to 70 wt. % of an urethane resin, 10 to 50 wt. % of an epoxy resin and 10 to 50 wt. % of nitrocellulose, and if necessary a curing agent.

A magnetic recording medium including a substrate having a magnetic coating layer thereon, said magnetic coating layer comprising ferromagnetic particles dispersed in a binder vehicle, characterized in that the magnetic coating layer contains one or more ketones selected from the compounds expressed by the general formula ##STR1## wherein R.sub.1 and R.sub.2 represent saturated or unsaturated chain aliphatic radicals, both or either of which have 11 to 22 carbon atoms and may contain hydroxyl, carboxyl or amino groups.

Both solid magnetic coat layers formed on a substrate of a magnetic recording medium by coating a magnetic varnish are simultaneously smoothed by passing the magnetic recording medium between one or more pairs of rigid rotary rolls which press both magnetic coat layers during their rotation.

Method for smoothing both magnetic coat layers of magnetic recording

A read device for reading magnetic data stored in a plane magnetic recording medium comprises a magnetic head for reading magnetic data stored in a rotatable flexible plane magnetic recording medium and a pad pushing a rear surface of the magnetic recording medium to a direction of the magnetic head so as to contact the front surface of the magnetic recording medium with the magnetic head, and means for adjusting a projected distance of the pad to the magnetic recording medium.

Read device for plane magnetic recording medium

A magnetic recording medium is disclosed as comprising powdered magnetic particles upon which there is deposited a ferro-magnetic metal or alloy such as cobalt or a cobalt alloy. Each magnetic particle is a spiculate magnetite and the deposite of cobalt or a cobalt alloy is in the range of 0.5 wt.% to 30 wt.%. The particles are heat treated in either a reducing or inert atmosphere to a sufficient temperature to improve the magnetic characteristics of the particles including their coercive force, Br/.rho. and Bm/.rho.. A layer of the recording medium is disposed on a support layer of polyester to form a magnetic tape.

Magnetic recording medium comprising cobalt or cobalt alloy coated

A process is disclosed for the production of powdered magnetic material for use in magnetic recording materials. The process comprises the steps of dispersing finely divided particles of a ferromagnetic oxide into an aqueous solution, dissolving therein salts of one or more ferromagnetic metals and a water soluble reducing agent, and then heating the dispersion while stirring to form and deposit a coating of the ferromagnetic metal (or alloy) on the surface of the finely divided particles of ferromagnetic oxide.

Growing community of inventors

Komoro, Japan

Fujio Shibata