JPS629520A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To improve the durability of the sliding of a titled medium with a head, to permit the easy handling of the medium and to improve the storage characteristic thereof by impregnating a perfluoroalkyl polyether lubricating agent into the porous part of a porous aluminum oxide film. CONSTITUTION:A high magnetic permeability film 7 consisting of Fe or Ni alloy is formed by sputtering on a polyester film 3 and a vertically magnetized film 8 consisting of Co-Cr is further formed likewise by sputtering thereon. The aluminum film is further formed thereon continuously in the same vacuum vessel. The aluminum film as an anode is then anodized in a sulfuric acid soln. to form a porous oxide film 9. The film is thereafter immersed in a soln. prepd. by dissolving the perfluoroalkyl polyether lubricating agent in a solvent after cleaning and drying and is dried at about 60 deg.C by which the medium impregnated with the lubricating agent 11 in the pore parts 10 is continuously formed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic recording medium used in floppy disks for external memory of computers, magnetic tapes for video tape recorders, and the like.

Conventional magnetic recording media include media in which magnetic powder 4 of metal or metal oxide is mixed with a binder 5 to form a coating material, and a magnetic layer is formed on a film 3 by a coating method, as shown in FIG. In this case, since it consists of magnetic powder 4, a binder 6 for binding it, a lubricant 6, and other fillers, there is a limit to the amount of magnetic powder per unit volume, and therefore the recording density There were also limits. Note that 2 is a magnetic head.

Problems to be Solved by the Invention Recently, the market has been demanding improved recording density. Media for forming metal thin films by vapor deposition, sputtering, or plating are expected, and research into this technology is being actively conducted.

FIG. 3 shows such a conventional metal thin film medium, where 7 is a permalloy high permeability film and 8 is a Go-Cr perpendicular magnetization film.

From a practical point of view, as mentioned above, with conventional coating media, a lubricant is also mixed at the same time as the paint is formed, so this lubricant functions as a lubricant on the media surface after the coating film hardens, and the floppy disk In an example, a sliding life of more than 100,000 busses has been confirmed.

On the other hand, in the case of metal thin film magnetic media, the film itself does not have a lubricating function, so when the head runs on the surface of the medium, direct metal-to-metal sliding occurs, which accelerates mutual wear and can be used for an extremely short time. Destruction of the metal thin film has been observed, and major practical issues remain.

As a solution, attempts have been made to form a solid protective film on the media surface and to use sticky lubricants, but the former has problems with the film thickness due to spacing loss between the head and the media. Due to the limitations, a practical durable life cannot be obtained, and the latter forms a sticky film on the surface of the medium, which poses problems in handling and storage, so it has not been put to practical use.

The present invention is intended to solve these problems, and aims to improve the durability of the sliding movement between the head and the medium, facilitate the handling of the medium, and solve storage problems.

Means for Solving the Problem In order to solve this problem, the present invention provides a surface of an extremely thin porous aluminum oxide film on the metal magnetic film within the allowable spacing loss between the head and the medium. By forming a protective film.

In addition to increasing the hardness of the sliding surface, the holes are impregnated with lubricant.

With this configuration, the extremely thin, hard protective film on the media surface minimizes the spacing loss between the head and the media and prevents wear on the media sliding surface. The lubricant impregnated into the oxide film improves lubricity and prevents wear on the head and media protective film, and by sealing the lubricant in the holes, it eliminates stickiness on the media surface and prevents dirt and grime during handling or storage. This will prevent problems such as dust adhesion.

Embodiment FIG. 1 is a sectional view of a metal thin film magnetic medium having a porous protective film according to an embodiment of the present invention. In FIG. 1, He is deposited on a polyester film 3.

A high magnetic permeability film 7 of N1 alloy is formed by sputtering, a Go-Or perpendicular magnetization film 8 is formed on it by sputtering, and an aluminum film is further formed on top of it in the same vacuum chamber. A film is continuously formed by sputtering, and then this aluminum film is used as an anode and anodized in a sulfuric acid solution to form a porous oxide film 9. After washing and drying, a perfluoroalkyl polyether lubricant is applied. Immerse it in a solution dissolved in a solvent for 60 minutes.
The medium was dried at .degree. C., the holes 10 were impregnated with the lubricant 11, and the medium was continuously prepared, and finally punched into the shape of a floppy disk.

Effects of the Invention As described above, according to the present invention, it is possible to form a thin, porous, uniform surface protective film that has a hard surface and an appropriate surface roughness of 200 Å or less, and has a high oil film strength. By using a perfluoroalkyl polyether lubricant that has strong lubricity, excellent lubricity and long-lasting properties, and is chemically stable and long-lasting in the pores, the durability of the head and media is dramatically improved. At the same time, stable electromagnetic conversion characteristics can be obtained, and the effects of easy handling and excellent storage properties can be obtained. Moreover, since the manufacturing method allows continuous production using a long film from film formation to anodization and lubricant impregnation, a practical effect can be obtained in that a product with stable characteristics can be supplied at a low cost.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a metal thin film magnetic recording medium having a porous protective film according to an embodiment of the present invention, FIG. 2 is a sectional view of a conventional coating type magnetic recording medium, and FIG. 3 is a sectional view of a metal thin film magnetic recording medium according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing a recording medium. 3... Film, 7... High magnetic permeability film,
8... Perpendicular magnetization film, 9... Oxide film,
10... Hole, 11... Lubricant.

Claims (1)

[Claims] A thin aluminum film layer is formed on at least one metal magnetic film formed on a non-magnetic film, a porous oxide film layer is formed on the aluminum layer, and a porous portion of the oxide film is formed. A magnetic recording medium made by impregnating perfluoroalkyl polyether lubricant.