JPS62219369A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To improve the scratch resistance and the wear resistance by impregnating a pad with a lubricant. CONSTITUTION:In a magnetic disk device which executes recording and reproduction by pressing a magnetic head from the opposite side, against a disk body which has been supported by a pad so that the magnetic head contacts the disk body by a prescribed contact pressure, the pad 20 consists of felt, and supported by a pad supporting body 22 so that a felt part 21 whose diameter is several mm and whose contact surface is a plane, and which consists of a columnar body contacts the disk body 10. The pad 20 consists of animal hair felt, and it is impregnated with alkylpolyether which has been fluorinated to a high level, as a lubricant.

Description

Detailed Description of the Invention [Field of Application] The present invention relates to a magnetic disk device using a disk body made of a flexible "A-film pear-shaped magnetic recording medium," and more specifically, to a magnetic disk device that uses a disk body made of a flexible "A-film pear-shaped magnetic recording medium," and more specifically, a magnetic disk drive in which a magnetic head is applied to the disk body with a predetermined contact pressure. The present invention relates to an improvement in a magnetic disk device that records and reproduces information by pressing a magnetic head from the opposite side against a disk body supported by pads so as to be in contact with the disk body.

[Prior art] The magnetic disk device mentioned above is a floppy disk.

It is well known as a microdisk and is widely used as an auxiliary storage device for computers.

In recent years, the demand for high-density recording has become higher and higher.
Instead of the conventional coated magnetic recording media that uses a binder in the disk body, there are those that use a ferromagnetic metal thin film for the magnetic recording layer, as well as Japanese Patent Publications No. 1983-91 and Japanese Patent Application Laid-Open No. 1982-5
It has been proposed to use a thin film type magnetic recording medium having a recording layer made of a metal thin film, such as one using a cobalt alloy metal film having perpendicular magnetic anisotropy, as disclosed in Japanese Patent No. 404. However, when such gold BWJWA is used as the magnetic recording layer, there is a drawback that it is susceptible to wear and damage and lacks durability because of the large frictional resistance with the magnetic recording head.

For this reason, various proposals have been made in the past in which organic polymers, high-hardness metals, ceramics, etc. are further provided as protective films on ferromagnetic metal thin films.

However, the wear resistance of magnetic disks using these thin-film magnetic recording media for the disk body, that is, the lifespan of the magnetic recording media when repeatedly run on a magnetic head, is longer than that of conventional coated magnetic recording media. It is inferior to a disk, and has the disadvantage that the metallic thin film itself is easily scratched and worn out, so it is still not in a satisfactory state for practical use.

[Object of the Invention] The present invention was made in view of the current situation, and is aimed at a magnetic disk device whose disk body is a thin-film magnetic recording medium that has sufficient scratch resistance and wear resistance for practical use. .

[Structure and effects of the invention] The above objects are achieved by the invention as follows.

That is, the present invention provides a magnetic disk device in which a disk body made of a flexible thin-film magnetic recording medium is supported by a pad, and a magnetic head is pressed against the rotating disk body from the opposite side of the support portion to perform recording and reproduction. This magnetic disk device is characterized in that a pad is impregnated with a lubricant.

The present invention described above was made as follows. In other words, as a result of various studies on sliding characteristics and durability, we found that if a thin-film magnetic recording medium is supported by a simple pad as in the past, the pad will cause scratches and other damage to the surface of the medium, as well as foreign matter. It has been found that these particles gradually expand and impair durability. As a result of various studies on countermeasures, it was surprisingly found that by impregnating the pad with lubricant, the occurrence of the above-mentioned scratches was suppressed, the adhesion of foreign substances was also reduced, and the durability was greatly improved. The heading was made.

This point will be explained below using an example using a WJwA type perpendicular magnetic recording medium.

FIG. 1 is an enlarged view of the configuration of the main parts of the embodiment.

In the figure, 10 is a disk body, 20 is a pad, and 30 is a perpendicular magnetic head.
Similar to the floppy drive (see figure), a spring is used to press the perpendicular magnetic head 30 against the pad 20 with a predetermined contact pressure, and it is incorporated into a commercially available floppy disk drive.

The disk body 10 is the following flexible double-sided perpendicular magnetic recording medium. That is, a polyethylene terephthalate film with a diameter of 5.25 inches and a thickness of 50 μm is used as a base 11, and on both sides thereof, a metal U layer 12 with high magnetic permeability made of a nickel-iron alloy with a thickness of 0.4 μm and a cobalt film with a thickness of 0.4 μm are formed. In Example 1, a perpendicular magnetic recording layer 13 made of a chromium (20 wt %) alloy thin film was sequentially laminated by the facing target sputtering method as in JP-A-57-100627. In Comparative Example 1), a protective film 14 of 300 cobalt oxides was further laminated thereon by reactive sputtering in an oxidizing gas atmosphere using cobalt metal as a target (Example 2).

The pad 20 is made of felt, and a felt portion 21 made of a cylindrical body with a diameter of several mm and a flat contact surface is supported by a pad support 22 so as to be in contact with the disk body 10. Specifically, the pad 20 is made of animal hair felt for National FDD JK875A, which is used as it is.
rytOX■143-AZ (manufactured by DuPont)
(Example 1.2) was prepared by impregnating Krytox@143AZ with CCf12F.
0 parts of the polyether in 100 parts of solvent such as CCuFz
．． The felt part 21 of the pad 20 is filled with liquids o and sg containing 2 parts.
The pad 20 was impregnated with water and dried to remove the solvent.

The perpendicular magnetic head 30 has a main magnetic pole 31 made of permalloy (nickel/iron) thin film with a width of 300 μm and a thickness of 1 μm.
It is supported by a zinc ferrite core 32, wound by an excitation coil 33, and further sandwiched between the tip of the main magnetic pole 31 so that the sliding surface with the disk body 10 is a spherical surface with a curvature of 50 mR and a diameter of 1.
A slider portion 34 made of cylindrical alumina-based ceramics of 0111I11 is provided, and comes into contact with the disk body 10 supported by the pad 20 with a predetermined contact pressure for recording and reproduction.

The durability is determined by the durability of the medium after 3 million busses when the perpendicular magnetic head 30 and the pad 20 are fixedly in contact with each other on a fixed radius (track) of the disk body 10, facing each other through the disk body 10. Evaluation was made by observing the occurrence of scratches and the state of soiling of the medium. The results are shown in Table 1.

Regarding media deterioration, the surface roughness before and after the sliding test is determined as the center line average roughness Ra using a surface roughness meter, and the relative value (Ra up) is calculated by dividing the Ra value after interlocking by the Ra value before sliding. Ratio). Therefore, the greater the Ra increase ratio, the rougher the surface of the medium after sliding.

It means that it has deteriorated.

From the examples shown in Table 1 and above, it is clear that a magnetic disk device having a thin ntA type magnetic recording medium excellent in durability as a disk body can be put to practical use according to the present invention in which the pad is impregnated with a lubricant.

However, it is clear from the gist of the present invention that the present invention is not limited to the above-described embodiments.

That is, the disk body of the present invention can be any thin film magnetic recording medium in which a magnetic recording layer made of a magnetic metal thin film is formed on a nonmagnetic support by a thin film forming method such as physical vapor deposition. For example, as a support, a polymer film such as polyester is used, and as a magnetic recording layer, Co-P system, Co
system, C0=Fe system, Co-Ni system, Co-Cr system, Fe
-Ni-based materials and other known materials can be used in a single layer or in combination in multiple layers. As is clear from the above examples, it is preferable to provide a protective film made of an inorganic substance, but such inorganic substances include Cr, N!, etc. for metals. ,
Examples include Rtl, Pd, Pj, W, and H (7) alloys, and examples of ceramics include carbides, nitrides, oxides, etc. of various metals and alloys. Among these inorganic substances, metal oxides are preferred, and oxides of aluminum, silicon, cobalt, chromium alloys, etc. are particularly preferred.

By the way, the above-mentioned disk main body is used while being housed in a case like a normal conventional floppy disk.

The case has a conventional liner on its inner surface, and can be made of plastic such as vinyl chloride resin.

The wall thickness of the case is not particularly limited, and it may be a flexible case or a hard case that does not easily deform.

Also, known liners can be used, such as woven fabric,
Examples include fabrics such as raised fabrics and non-woven fabrics, and materials include natural fibers such as cotton, recycled fibers such as rayon, semi-synthetic fibers such as acetate, and synthetic fibers such as polypropylene, polyester, and nylon. . The liner is preferably impregnated with a lubricant, similar to conventional floppy disks. Examples of such lubricants include those mainly composed of highly fluorinated alkyl polyethers, which will be described later.

On the other hand, the pad itself can be of any known type, but it is preferably felt, which is an aggregate of fibers such as natural fibers and synthetic fibers, and more preferably animal hair such as wool and rabbit hair among natural fibers. It is. Impregnate the pad 1
lFfl agent is the W of conventional floppy disk liner.
Although known lubricants such as JW4 agent can be used as they are, a lubricant mainly consisting of a highly fluorinated alkyl polyether disclosed in Japanese Patent Publication No. 55-2666 is preferably used. In addition, as this highly fluorinated alkyl polyether, repeating units -CF2 CF2 0, -CF-CF2 are used as described in the same publication.
Highly fluorinated ethyl polyethers such as 0-CF3.

I can give you propyl polyether. In order to impregnate the liner with a lubricant such as highly fluorinated alkyl polyether, the lubricant such as highly fluorinated alkyl polyether is mixed and dissolved in a solvent such as water or a paid solvent. Just soak the liner. On this occasion,
A binder and other additives may be added to the solution.

Conventional types such as magnetic heads and ring heads can also be applied.

Part of the slider can be applied to either a flat type with a flat contact surface with the disk body or a button type with a spherical contact surface, but from the viewpoint of durability and stable recording and playback characteristics, a felt pad with a flat contact surface is applicable. In this combination, a button type is preferable. Also, if you prepare two sets of these head and button combinations and arrange them so that both sides of the disc body can be recorded and played,
A double-sided magnetic disk device is obtained. In this double-sided type, the flat pad and the button-shaped head are arranged side by side on one support, and this is arranged on both sides of the disc body so that the head of one support and the pad of the other support face each other. , the structure is similar to that of the embodiment and is pressed against the disk body from both sides with a predetermined contact pressure using a spring or the like, which is durable.

This is preferable in terms of recording/reproducing characteristics and in that the conventional floppy disk mechanism can be applied as is.

As described above, the present invention can be implemented in various embodiments and is very useful in providing a magnetic disk device whose disk main body is a flexible thin-film magnetic recording medium with excellent durability and stability in recording and reproducing characteristics. .

[Brief explanation of drawings]

FIG. 1 is an enlarged side sectional view of the main parts of the embodiment. 10: Disc body, 20: Pad 30: Vertical magnetic head -X 11 cheers

Claims (1)

[Claims] 1. A magnetic recording and reproducing system in which a disk body made of a flexible thin-film magnetic recording medium is supported by a pad, and a magnetic head is pressed against the rotating disk body from the opposite side of the support. A magnetic disk device characterized in that a pad is impregnated with a lubricant. 2. The magnetic disk device according to claim 1, wherein the contact surface of the magnetic head with the disk is a spherical surface, and the contact surface of the pad is a flat surface. 3. A patent claim in which a magnetic head and a pad are arranged side by side on a common support, and the magnetic head on one support and the pad on the other support are provided on both sides of the disk body so as to face each other. A magnetic disk device according to scope 1 or 2. 4. A magnetic disk drive according to any one of claims 1 to 3, wherein the pad is made of felt and impregnated with a lubricant mainly made of highly fluorinated polyether. 5. Claims 1 to 5 comprising a thin-film magnetic recording medium in which the disk body has a protective film made of an inorganic material on the surface layer.
Any of the magnetic disk devices described in item 4. 6. The magnetic disk device according to claim 5, wherein the disk main body is housed in a case having a liner whose inner surface is impregnated with lubricant.