Sony Corporation

Seiichi Onodera

Naoki Ikeda

Kazunari Motohashi

Shinya Yoshida

Tomoe Sato

Takashi Kanou

Hiroshi Kano

Kazuhiko Suzuki

Ken Kobayashi

Tadashi Ozue

Yoshito Ikeda

Takanori Sato

Teruo Inaguma

Hidetoshi Honda

Seiji Onoe

Takahiro Kawana

Hitoshi Wako

Tetsuo Samoto

Yutaka Iwamoto

Tomoe Iwano

Daizo Shiga

A magnetic recording medium includes a tape-shaped nonmagnetic support, and a vertical magnetic layer formed on a main surface of the nonmagnetic support by a vacuum thin-film forming technique, signals being recorded on and reproduced from the vertical magnetic layer in a linear system. In the magnetic recording medium, the dipulse ratio of the vertical recording layer is 0.36 or more.

Magnetic recording medium and magnetic recording/reproducing system

The present invention provides a lubricant capable of holding an excellent lubricating property under various types of service conditions, maintaining a lubricating effect for a long period of time and providing excellent traveling property, abrasion resistance, durability and the like, a recording medium using the lubricant and a carboxylic acid type compound constituting the lubricant. The lubricant is formed by using a carboxylic acid type compound having at least two carboxyl groups and one ester bond as represented by the following general formula (1) (for example, a compound as represented by the following chemical formula (1)) as a constituting mixture and, then, the thus-formed lubricant is allowed to be contained on or in a recording layer of the recording medium: in which Rf represents a non-substituted or substituted, saturated or unsaturated, fluorine-containing hydrocarbon group or hydrocarbon group; Es represents an ester bond; and R may be omitted or represent a non-substituted or substituted, saturated or unsaturated hydrocarbon group.

Lubricant, recording medium and carboxylic acid compound

There is provided a magnetic recording medium which exhibits superior lubricating properties and superior tape-transport properties as well as superior robustness even in a low-temperature environment. A magnetic layer containing a ferromagnetic metal is formed on a nonmagnetic support, and a protecting film is formed on the magnetic layer. A lubricant auxiliary coating composition comprising an aromatic alcohol is applied to the protecting film to form a lubricant auxiliary layer, and a lubricant coating composition comprising a compound represented by the formula (1) below is applied to the lubricant auxiliary layer to form a lubricant layer.RCH(COOR)CHCOOR&#x2003;&#x2003;(1)wherein Rrepresents an aliphatic alkyl group, an aliphatic alkenyl group, or a hydrogen atom, and each of Rand Rindependently represents a fluoroalkyl group, a fluoroalkenyl group, a fluoropolyether group, or a hydrogen atom.

Magnetic recording medium

Fine projections on a magnetic layer surface are controlled so as to reduce a media noise and improve C/N characteristic. A magnetic recording medium allows reproduction through a MR head or a GMR head. The magnetic layer on a main surface of a non-magnetic base has a coercive force of 80 KA/m or more and 180 KA/m or less. Assuming that a height of the fine projections is h and a diameter of the fine projections at a half-height h/2 is &phgr; , 99% of the fine projections having a height not less than 10 nm satisfy a relationship as expressed by 100 nm&gE;&phgr; &gE;40 nm.

In the metallic thin film magnetic recording medium having the magnetic layer formed on a main face of a nonmagnetic supporting body according to vacuum thin film formation technology, the thickness of the nonmagnetic supporting body is 5 &mgr;m or less, the thickness of the magnetic layer is 20 nm-100 nm and a lining layer 20 nm-200 am in thickness is formed of metal, non-metal or alloy of these materials or oxide compound thereof according to vacuum thin film formation technology. Light transmittance is 5% or less and permeating water vapor amount is 5 g/m &middot;day or less. The lining layer and the back layer are formed successively on a main face opposite to the magnetic layer formation face. The relative roughness factor (Ra) of the topmost surface of the lining layer formation face is 2-15 nm.

Metallic thin film magnetic recording medium

Magnetoresistive head with azimuth angle and magnetic recording/reproducing tape apparatus using same

Growing community of inventors

Miyagi, Japan

Seiichi Onodera