Abstract: A magnetic disk cartridge retains a rotational magnetic disk in a case through liners, which contact the associated surfaces of the disk and each have multiple long protrusions formed almost uniformly and almost in parallel to one another on the whole surface on the disk side. As the magnetic disk rotates, the angle of the disk surface contacting the long protrusions can gradually change, thus ensuring removal of dust from the disk. In additon, this structure can reduce the frictional resistance between the liner's surface and magnetic disk, which contributes to faster rotation of the disk.

Abstract: In a magnetic disk jacket including a liner partly welded to the inner surface of a case and adapted to clean the surface of a magnetic disk, the liner contains 0.001 to 0.05g of a polydimethylsiloxane derivative having a viscosity of from 50 to 3000 cSt at 25.degree. C. and having a polyether group or both polyether group and epoxy group in a molecule per 1 g of the liner.

Abstract: This invention provides an inexpensive structure for a protecting jacket for rotatable magnetic recording media which has a dimension sufficient to cover openings on the jacket and is provided as a sheet adhered to the jacket to cover said openings and prevent entry of dust.

Abstract: The present invention concerns a glass-like carbon material which may be bonded to other materials, the carbon material having a high thermal expansion coefficient and being highly applicable for use as a slider part for a recording medium.

Abstract: A substrate for magnetic discs, which are to be used as external storage in data processors, is formed from glass-like carbon materials by themselves or contained in a thermosetting resin matrix. The glass-like carbon materials have excellent thermal resistance, can be finished to a mirror-like surface, and have less surface defects than aluminum substrates. Magnetic materials can be adhered directly onto the surface of such substrates shaped in the form of a disc. The resulting disc has good hardness, is resistant to elevated temperatures, is less likely to deform, and is low in cost.

Abstract: A magnetic recording medium exhibiting reduced abrasion and improved lubricant properties comprising a non-magnetic substrate having a magnetic layer containing a magnetic powder thereon, the magnetic layer including a glasslike carbon powder having an average particle diameter of from 0.1 to 2.0 .mu.m present in an amount of from 0.5 to 15 parts by weight per 100 parts by weight of the magnetic powder.

Abstract: A magnetic head for recording and reading out of a magnetic recording medium in a perpendicular magnetic recording system is described in which the surface which is close to or in contact with the recording medium are covered with a film of a glasslike carbon material. This film improves the lubrication properties with respect to the adjacent recording medium and serves to prevent abrasion.

Abstract: A magnetic head is disclosed in which a non-magnetic base substance which supports a writing or reading converter for writing or reading on a magnetic recording medium is constructed with an aggregate of carbon material, or a composite material comprising an aggregate of carbon material, and a thermosetting resin and/or a carbonaceous filler.