JPH0684168A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To achieve improved wear resistance and lubrication characteristics by forming a carbon lamination protection film consisting of two layers of a wear resistance film and a lubrication film which are formed on a non- magnetic substrate. CONSTITUTION:An intermediate layer 2 such as Cr alloy is provided on a non- magnetic substrate 1 such as Al allay or a glass and then a magnetic layer 3 consisting of Co or its alloy is provided on it and further a carbon lamination protection layer 4 and an organic lubrication layer 5 are provided on it. The protection layer 4 consists of two layers of a wear resistance film 4a containing nitrogen with improved wear resistance and a lubrication film 4b containing hydrogen with improved lubrication characteristics. The wear resistance film 4a is formed in a mixed gas with Ar gas containing 25% nitrogen gas and the lubrication film 4b is formed in Ar gas containing 20% hydrogen gas. Since the carbon lamination protection film consisting of the wear resistance film 4a and the lubrication film 4b is formed on the magnetic layer 3, a magnetic recording medium with improved wear resistance and lubrication characteristics can be mass-produced inexpensively with a high yield.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording medium such as a magnetic disk used in computers, word processors and the like.

[0002]

2. Description of the Related Art In recent years, a metal thin film disk has been used as a magnetic recording medium for high density recording. When performing recording / reproducing on such a magnetic recording medium, the CSS method (contact start / stop method) is generally used. In the above method, the magnetic head and the magnetic recording medium are in contact with each other when stopped, and a minute air layer is formed between the magnetic head and the magnetic recording medium by applying rotation to the magnetic recording medium. It is formed and recorded and reproduced.

In such a CSS system, the frictional force generated between the magnetic head and the magnetic recording medium sometimes damages the magnetic layer, or the rotation of the magnetic recording medium is hindered by an adsorption phenomenon at the start of operation. I have something to do. Therefore, a carbon-based protective film having abrasion resistance and lubricity is formed by a sputtering method, and an organic lubricant is applied on the carbon-based protective film to prevent an increase in the friction coefficient. For higher density, the material of magnetic head is ferrite to ceramic,
Since Al ₂ O ₃ TiC and hard materials tend to be used, it is indispensable to improve wear resistance performance for magnetic recording media.
Furthermore, as a labor-saving measure, it is equipped with a function to automatically turn off the power when it is not used for a long time, and the number of times of CSS is increasing.

[0004]

However, in the structure of the conventional magnetic recording medium described above, there is a problem that a carbon-based protective film containing no nitrogen cannot provide sufficient abrasion resistance. In addition, the carbon-based protective film formed in nitrogen gas has a problem of increasing the friction coefficient due to the phenomenon of adsorption to the magnetic head, and therefore it has become essential to make the organic lubricating film as thin as possible. .

The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a magnetic recording medium such as a magnetic disk excellent in lubricity and wear resistance.

[0006]

In order to achieve the above object, a magnetic recording medium of the present invention is a carbon-based medium in which two layers of a wear resistant film and a lubricating film are laminated on a magnetic layer on a non-magnetic substrate. A laminated protective layer is provided, and the wear-resistant film is a nitrogen-containing wear-resistant film and the lubricating film is a hydrogen-containing lubricating film.

[0007]

According to the present invention, therefore, excellent wear resistance and lubricity can be obtained by dividing the carbon-based laminated protective layer into two layers and comprising a nitrogen-containing wear resistant film and a hydrogen-containing lubricative film. be able to.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a magnetic recording medium according to an embodiment of the present invention. In the figure, 1 is a non-magnetic substrate made of aluminum alloy, glass, etc., 2 is an intermediate layer made of chromium alloy, 3 is a magnetic layer made of cobalt or its alloy, 4 is a carbon-based laminated protective film, and has excellent wear resistance It is composed of two layers, that is, an excellent wear resistant film 4a containing nitrogen and a lubricating film 4b containing hydrogen excellent in lubricating property. Reference numeral 5 is an organic lubricating layer.

Samples of the magnetic recording mediums of the examples and comparative examples having the above-mentioned constitution were prepared as follows.

(Example 1) An abrasion resistant film 4a was formed in a mixed gas of argon gas containing 25% of nitrogen gas,
A lubricous film 4b was formed thereon in an argon gas containing 20% hydrogen gas to prepare a sample of a magnetic recording medium.

Example 2 A magnetic recording medium sample was prepared in the same manner as in Example 1 except that the abrasion resistant film 4a was formed in nitrogen gas instead of mixed gas.

(Comparative Example 1) A wear-resistant film 4a is formed in an argon gas containing no nitrogen gas, and a lubricating film 4b is formed thereon in a mixed gas of argon gas containing no nitrogen gas and hydrogen gas. Was formed into a film to prepare a magnetic recording medium sample.

(Comparative Example 2) A sample of a magnetic recording medium was prepared in the same manner as in (Example 2) except that the lubricating film 4b was formed in nitrogen gas. It means that it is composed entirely of the abrasion resistant film 4a).

A sliding test, an adsorption test and a peel strength were measured for each of the examples and comparative examples configured as described above.

[0016]

[Table 1]

The above (Table 1) shows the influence on the magnetic layer after the low speed sliding test was conducted on the above (Examples 1 and 2) and (Comparative Examples 1 and 2). It was performed using a 50 × microscope. Sliding condition is disk rotation speed 1
Rotate at 00 rpm and put the magnetic head on it 6
It was performed by sliding for 0 min. The slider component of the magnetic head used here is a monolithic type magnetic head whose main component is Mn-Zn-Fe,
The head load was 9.5 g. The magnetic disk used in this test is a non-circulating magnetic disk having no organic lubricating layer 5 shown in FIG.

As is clear from Table 1, in the appearance inspection of the magnetic recording medium after the test, in Examples 1 and 2, no damage to the magnetic layer 3 was observed, and in Comparative Examples 1 and 2. )
Shows scratches that are thought to have been damaged by the friction between the ABS of the magnetic head slider and the magnetic disk. This indicates the relationship between the hardness of the magnetic head and the hardness of the carbon-based protective film, and indicates that the hardness of the magnetic disk is harder than the magnetic head material.

Next, (Table 2) shows the results of measuring the adsorption characteristics of (Examples 1 and 2) and (Comparative Examples 1 and 2).

[0020]

[Table 2]

The conditions of the adsorption test are as follows: a magnetic head is kept in contact with a constant temperature and humidity chamber at 65 ° C. and 80% RH for 24 hours, the magnetic disk is left unrotated, and further left at room temperature and normal humidity for 24 hours. The initial torque was measured.

As the magnetic head for the test, a composite type magnetic head containing calcium titanate as a main component was used.

As is clear from Table 2, the adsorption characteristics include the lubricating film 4b formed by using a mixed gas of argon gas or hydrogen gas (Examples 1, 2, and 3).
Comparative Example 1) is superior, while the abrasion-resistant film 4a formed only in a mixed gas containing nitrogen (Comparative Example 2) is excellent in wettability with water, and is therefore an organic lubricant. Layer 5
The wettability does not deteriorate even when applied with water, and as a result, water and lubricant are evenly present between the magnetic head and the magnetic recording medium under high humidity to cause an adsorption phenomenon, resulting in a large friction coefficient (μs). Become.

Next, (Table 3) shows the results of measuring the peel strength of (Examples 1 and 2) and (Comparative Examples 1 and 2).

[0025]

[Table 3]

The peel strength was measured by oscillating the needle left and right using a diamond needle. With respect to this peel strength, the adhesion between the magnetic film and the carbon-based protective film and the hardness of the carbon-based protective film are simultaneously evaluated from the principle of measurement.

As is clear from (Table 3), (Examples 1 and 2) have a peel strength of 1 to 3 gf higher than that of (Comparative Examples 1 and 2).

As described above, according to the above embodiment, the abrasion resistant film 4a is formed in a mixed gas of nitrogen gas and argon gas or in nitrogen gas, and the lubricating film 4b is formed thereon with argon gas and hydrogen gas. Since the film is formed in the mixed gas of, wear resistance and lubricity can be improved. The thickness of each of the wear resistant film 4a and the lubricating film 4b is at least 10 nm.
The above is necessary, and the total thickness of the carbon-based laminated protective film 4 is 40 n.
It is desirable that it is m or less.

[0029]

As is apparent from the above embodiments, according to the present invention, a carbon-based laminated protective film consisting of two layers of a wear resistant film and a lubricious film is formed on a magnetic layer formed on a non-magnetic substrate. The magnetic recording medium having excellent wear resistance and lubrication characteristics can be mass-produced with high yield and at low cost.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a magnetic recording medium that is an embodiment of the present invention.

[Explanation of symbols]

 1 Non-Magnetic Substrate 2 Intermediate Layer 3 Magnetic Layer 4 Carbon-Based Laminated Protective Film 4a Abrasion Resistant Film 4b Lubricating Film

Claims (3)

[Claims] 1. A magnetic recording medium comprising a non-magnetic substrate, an intermediate layer, a magnetic layer, and a carbon-based lubrication protective layer formed on the non-magnetic substrate, wherein the carbon-based lubrication protective layer is a wear-resistant film and a lubrication film. Of 2
A magnetic recording medium, which is a carbon-based laminated protective layer laminated on a layer. 2. The magnetic recording medium according to claim 1, wherein the wear-resistant film is a nitrogen-containing wear-resistant film formed in a mixed gas of argon gas and nitrogen gas or nitrogen gas as a sputtering gas. 3. The magnetic recording medium according to claim 1, wherein the lubricating film is a hydrogen-containing lubricating film formed as a sputtering gas in a mixed gas of argon gas and hydrogen gas.