JPH08161736A - Manufacture of magnetic recording medium - Google Patents

Abstract

PURPOSE: To obtain an excellent magnetic recording medium with limited foul of a head even under a high temperature and high humidity. CONSTITUTION: A method of manufacturing a magnetic recording medium in which a magnetic layer, a protective layer and a lubrication layer are formed sequentially on a non-magnetic substrate, prior to the formation of the lubrication layer, a washing is made by hot pure water above 55 deg.C but below 90 deg.C. This enables the obtaining of a magnetic recording medium which excels in durability with excellent lubricating property and wear resistance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a high recording density magnetic recording medium used in the information industry and the like.

[0002]

2. Description of the Related Art A thin film magnetic recording medium, which is a typical example of a high recording density magnetic recording medium used in the information industry, is
It is usually manufactured by depositing a magnetic metal or its alloy on a non-magnetic substrate by plating, vapor deposition or sputtering. In actual use, the magnetic head and the magnetic recording medium come into contact with each other at high speed and slide, so that the magnetic head may be damaged by wear or the magnetic characteristics may be deteriorated.

As a method for solving such a drawback, it has been proposed to provide a protective film or a lubricating layer on the magnetic layer to reduce static / dynamic friction during contact sliding as much as possible and improve wear resistance. ing. As the protective film, a carbonaceous film,
An oxide film, a nitride film, a boride film or the like is used.

[0004]

When the magnetic recording medium is used, the disk medium is rapidly rotated and accelerated from a stopped state. Along with this, buoyancy is applied to the flying head slider and the head flies. When the power is cut off after use, the motor that rotates the disk medium stops, and the head and medium make contact at high speed and slide.

However, in recent years, in order to increase the areal recording density, it is required to lower the flying height of the head and increase the disk rotation speed. The media substrate tends to be smoother. It is very effective to provide a liquid lubricant film to reduce the dynamic friction coefficient, but as the liquid lubricant film is made thicker, a micromeniscus is formed between the head and the disk due to the surface tension of the liquid lubricant. It is known that the sticking phenomenon occurs. For this reason, it has been pointed out that the static friction coefficient increases, and the head is often inoperable while being stuck to the disk.

[0006]

A method of manufacturing a magnetic recording medium according to the present invention is characterized in that an excellent magnetic recording medium with less head contamination even under high temperature and high humidity is obtained. The magnetic recording medium obtained by the present invention can be applied to a composite head, a MIG head and a thin film head. Hereinafter, the present invention will be described in detail.

In the magnetic recording medium to which the present invention is applied, as the non-magnetic substrate, an aluminum alloy plate or a glass substrate provided with a nickel-phosphorus layer is usually used, but in addition to this, a ceramic substrate, a carbon substrate, a resin substrate. Etc. can also be used. As the magnetic layer, after providing an undercoat layer if necessary, for example, Co or CoP-based alloy, C
A Co alloy such as an oNiP-based alloy, a CoNiCr-based alloy, a CoNiPt-based alloy, a CoCrPt-based alloy, and a CoCrPtTa-based alloy is formed by an electroless plating method, a sputtering method, or the like. The film thickness of the magnetic layer is determined by the characteristics required for the magnetic recording medium, and is usually 200 to 150.
It is 0Å. The protective film on the thin film magnetic layer is not necessarily essential, and is formed as necessary in consideration of physical properties such as hardness and elastic modulus of the magnetic film. A carbonaceous film, an oxide film, a nitride film, a boride film or the like is used as the protective film,
It is formed by a sputtering method, an ion plating method, a plasma polymerization method, or the like. A carbonaceous film such as amorphous carbon or hydrogenated carbon is preferably used as the protective film, and is usually 50 to 500 Å, preferably 100 to 3
Used with a film thickness of 00Å. If necessary, surface treatment of the protective film such as irradiation with ultraviolet rays can be performed.

The surface of the formed protective film is washed with warm pure water, and then a lubricating layer is formed. It is considered that the water-soluble impurities existing on the surface of the protective film weaken the binding force between the protective film and the lubricant, and the lubricant is transferred to the head when the disk is driven.
By cleaning the impurities on the disk surface with warm pure water to elute and remove the impurities before forming the lubricating layer, the lubricating layer can be formed on a clean surface. It is considered that there is no part where the protective film and the lubricant have a weak bonding force, and the head is not contaminated even if CSS is performed. It is possible to obtain a disk with less head contamination not only under normal temperature and normal humidity but also under severe environments such as high temperature and high humidity. As a cleaning method, the disk is dipped in warm pure water and then dried. The temperature of the hot pure water is required to be a temperature at which the surface of the disk dries after it is dipped, and 55 ° C. or more and 90 ° C. or less is suitable within a temperature range where pure water does not boil. Ultrasonic cleaning may be performed together with the step of cleaning with warm pure water.

[0009]

EXAMPLES Next, the present invention will be described more specifically by way of examples, but the present invention is not limited to the following examples unless it exceeds the gist. Example 1 A chromium underlayer (500 Å) and a cobalt alloy magnetic thin film (6) were formed on an aluminum alloy substrate by a sputtering method.
00 Å) and the carbonaceous protective film (260 Å) were formed, and the magnetic disk having a diameter of 3.5 inches and subjected to tape cleaning treatment was dipped in warm pure water at a temperature of 65 ° C for 30 seconds and dried. A perfluoropolyether lubricating layer (Fombline Z Dol / 2000) was formed on this disc, and glide treatment was performed.

For the glide-treated disk,
CSS test under the environment of temperature 32 ° C and relative humidity 80%
When I went, almost no dirt on the head was seen
Was. For the CSS test, select a thin film with a peripheral speed of 3600 rpm.
Dead slider (material: Al ₂0₃TiC)
It was. Energize the spindle for 10 seconds, then power for 24 seconds
The total of 34 seconds for disconnecting the
Eggling was performed 20000 times.

Example 2 A magnetic disk obtained in the same manner as in Example 1 except that it was immersed in warm pure water at a temperature of 73 ° C. after the tape cleaning treatment was subjected to a CSS test. It was hardly seen. Comparative Example 1 A magnetic disk obtained in the same manner as in Example 1 except that it was immersed in pure water at a temperature of 25 ° C. after the tape cleaning treatment was subjected to a CSS test. I was seen.

Comparative Example 2 A disk which was subjected to the same treatment as in Example 1 up to the tape cleaning was subjected to the CSS test in the same manner as in Example 1 with respect to the disk on which the lubricating layer was formed and the glide treatment was carried out. Severe dirt was found on the entire head.

[0013]

According to the present invention, a thin film having excellent lubricity
It is possible to obtain a highly reliable magnetic recording medium which has abrasion resistance and can maintain excellent durability for a long period of time.
Even in the SS test, the contamination of the head can be reduced, and a highly reliable magnetic recording medium can be obtained for a long period of time.

Claims (2)

[Claims] 1. A method of manufacturing a magnetic recording medium comprising a magnetic layer, a protective layer and a lubricating layer which are sequentially formed on a non-magnetic substrate,
A method for manufacturing a magnetic recording medium, which comprises washing with warm pure water of 55 ° C. or higher and 90 ° C. or lower before forming a lubricating layer 2. A method of manufacturing a magnetic recording medium according to claim 1, wherein ultrasonic cleaning is performed before forming the lubricating layer.