JPH02304714A - Magnetic recording medium and its production - Google Patents

Abstract

PURPOSE:To obtain a magnetic recording medium which is free from mechanical damage in its ferromagnetic metal medium and shows no increase in the coefft. of friction by covering with a thin film comprising oxides, nitrides, carbides or carbon on the ferromagnetic metal medium and then impregnating the film with a liquid lubricant or a solid lubricant. CONSTITUTION:A thin film comprising at least one material selected from oxides, nitrides, carbides and carbon is formed on the ferromagnetic metal medium, and then the thin film is impregnated with at least one kind of liquid lubricant or solid lubricant. Although oxides, nitrides, carbides and carbon formed on the ferromagnetic metal substrate act as a buffer against impact by a magnetic head, even the film is abraded on CSS when the magnetic head has a hard slider. Therefore, it is necessary to laminate a single layer, mixture or multilayer of liquid lubricant and/or solid lubricant with good lublicity. Or a diluted soltuion of liquid or solid lubricant is made to diffuse or permeate in the thin film of oxide, nitride, carbide or carbon by use of ultrasonic in the process of coating the lubricant. Thus, the medium has long-term CSS dura bility.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic storage medium comprising a ferromagnetic metal thin film provided on a non-magnetic substrate, and a method for manufacturing the same.

[Conventional technology]

It is essential for a magnetic storage medium having a metal medium to have sufficient mechanical reliability to withstand contact with a magnetic head. Contact start/stop (hereinafter referred to as C8S method) has been adopted for magnetic storage media to simplify the drive configuration, and in order to protect the magnetic recording surface, cs is applied to the same track in the shipping zone other than the magnetic recording surface.
s-b: Often performed.

In addition, as magnetic recording density increases, magnetic heads are changing from ferrite mini-monolithic heads to composite heads and thin film heads, and as the hardness of slider materials increases, there is a need to improve the durability of the protective film of magnetic storage media. .

Conventionally, there has been a method of providing an organic lubricant layer of saturated fatty acids or the like on the surface of a metal magnetic medium (Japanese Patent Publication No. 56-30609), a method of providing a mixed lubricant layer of fatty acid amide and a phosphorus compound (Japanese Patent Publication No. 56-30609).
9-165238) There is a method of providing a mixed lubricating layer of higher fatty acids and fatty acid metal salts (Japanese Patent Publication No. 59-177728), but C
8S has problems with increased friction coefficient and crashes.

Carbonaceous film exhibiting the characteristics of both a lubricating layer and a protective film layer (Japanese Patent Publication No. 54-33521) (Japanese Patent Publication No. 53-143206) (
Japanese Patent Application Laid-Open No. 56-41524) does not cause scratches during C8S and buffers the impact of the magnetic head, so no deterioration of magnetic properties is observed. However, in C8S with a magnetic head with a highly hard slider, There was a problem in that as the carbonaceous film increased, the carbonaceous film was worn away and the abrasive coefficient increased.

[Problem and purpose to be solved by the invention] As mentioned above
In the conventional technology, sufficient mechanical reliability could not be obtained with C8S using a magnetic head having a highly hard slider, and an increase in the coefficient of friction could not be suppressed.

Therefore, the present invention is intended to solve these problems, and its purpose is to avoid mechanical damage to the ferromagnetic metal medium even with C8S in a magnetic head with a highly hard slider, and to increase the coefficient of friction. The objective is to provide a magnetic storage medium that does not.

[Means to solve the problem]

In the magnetic storage medium of the present invention, a ferromagnetic metal medium formed on a non-magnetic substrate is coated with a thin film made of at least one substance selected from oxides, nitrides, carbides, and carbon. It is characterized by being impregnated with at least one type of liquid lubricant or solid lubricant using ultrasonic waves.

Oxides include 5if2, TiC2, Cr, 03, etc., nitrides include TiN, TazN, AIN, S 1sNt, etc., carbides include SiC, TiC, etc., and carbon includes diamond, diamond, etc.
It may be either graphite or amorphous, and the film thickness is 150 to 800.

The above can be formed by any method such as a vacuum evaporation method, a sputtering method, an ion blating method, or a CVD method.

In addition to the ultrasonic method, lubrication can be impregnated by a high-pressure jet spray method, a bubble jet method, a HIP method, or the like.

Perfluoropolyether is used as the liquid lubricant, and higher alcohol, saturated or unsaturated fatty acid, etc. are used as the solid lubricant. Both are diluted with a soluble solvent and formed by the above-mentioned impregnation method and dipping.

[Effect]

The oxides, nitrides, carbides, and carbon formed on the ferromagnetic metal medium have the function of buffering the impact of the magnetic head, but they are scraped by C8S with a magnetic head having a highly hard slider. Therefore, liquid lubricants and solid lubricants with excellent lubricity are used in a single layer, mixed or laminated.

The N film of oxide, nitride, carbide, and carbon is formed as a porous film, and simply covering it with a lubricant cannot clear C8S in a hard magnetic head.

In the present invention, in the lubricant application step, ultrasonic waves are applied to the diluted solvent of liquid lubrication or solid lubrication to diffuse and penetrate the lubricant into a thin film of oxide, nitride, carbide, or carbon.

By maintaining the effect of this impregnated lubricant, it became possible to ensure long-term C8S durability.

Next, examples will be specifically explained.

[Example-1] Approximately 15 μm of N1-P alloy plating was applied as non-magnetic alloy plating to a disk-shaped aluminum alloy substrate with mirror finish.
After plating to a thickness of m, polish to a thickness of 10 μm and a surface roughness of 0.03 μm or less, and then coat as a metal magnetic thin film.
o-N1-P alloy was plated to a thickness of about 0.06 μm.

Next, 300 amorphous carbonaceous films were formed by magnetron sputtering.

Next, Fomblin AM2001 (liquid lubricant) was dissolved in Daiflon S-3 solvent at a concentration of O,0 OIW/V%, and 6
After applying ultrasonic waves (30 kHz, 1.6 W/cm) for 0 seconds, coating was performed by a dipping method (10 cm 2 /I!1 inch).

[Example 2] A disk having a metal medium was produced in the same manner as in Example 1.

Next, 700 Ta2N films were formed using a magnetron sputtering device. Next, lignoceric acid (solid lubricant) was added to a mixed solvent of Daiflon S-3 and methanol (volume ratio 80:20).
) at a concentration of 0.002 W/V%, and after applying ultrasonic waves (25 kHz, 0.8 W/c+1) for 30 seconds, it was applied by a dipping method (10 cta/min).

[Example 3] A disk having a metal medium was produced in the same manner as in Example 1.

Next, 800 graphite-like carbonaceous films were formed using a magnetron sputtering device. Next, Stearin M (solid lubricant) was added to a mixed solvent of Daiflon S-3 and methanol (volume ratio 60:40) at 0.0. Dissolved at OIW/V% concentration,
Ultrasound for 120 seconds (30kHz, 1,2W/cj
) and then applied by dipping method (100 m/m1n).

[Example 4] A disk having a metal medium was produced in the same manner as in Example 1.

Next, 500 graphite-like carbonaceous films were formed using a magnetron sputtering device. Next, potassium stearate (
A solid lubricant) was dissolved in a mixed solvent of Daiflon S-3 and methanol (volume ratio 75:25) at a concentration of 0.002 W/V%, and then subjected to ultrasonic waves (15 kHz, 0.8 w/c) for 30 seconds.
+a) and then the dipping method (LoCm/m1
n).

[Comparative Example-1] A sample was prepared in Example 1 by applying lubrication without applying ultrasonic waves.

[Comparative Example-2] A sample was prepared in Example 2 by applying lubrication without applying ultrasonic waves.

[Comparative Example-3] A sample was prepared in Example 3 by applying lubrication without applying ultrasonic waves.

[Comparative Example-4] A sample was prepared in Example 4 by applying lubrication without applying ultrasonic waves.

[Comparative Example-5] A sample was prepared in Example 4 without applying a lubricant.

The disks of the above Examples and Comparative Examples were subjected to a C8S test. C
In the SS test, a thin film head made of alumina titanium carbide as a slider material with a flying height of 0.20 μm and Hv 1200 was used to measure the coefficient of static friction before CSS and after 20000 cycles of C3S. The results are shown in Table 1.

〔Effect of the invention〕

As described above, according to the present invention, oxides, nitrides,
The durability of CSS has been improved by forcibly impregnating and diffusing a liquid lubricant or solid lubricant into carbide or carbon using ultrasonic waves.

Furthermore, improvements in the durability of hard magnetic heads have made it possible to provide magnetic disks with high recording densities.

Table 1 company

Claims (4)

[Claims] (1) A ferromagnetic metal thin film medium formed on a nonmagnetic substrate is coated with a thin film made of at least one substance selected from oxides, nitrides, carbides, or carbon, and a liquid lubricant or A magnetic storage medium impregnated with at least one solid lubricant. (2) A thin film made of at least one substance selected from oxides, nitrides, carbides, or carbon is impregnated with at least one liquid lubricant or solid lubricant using ultrasonic waves. 2. The magnetic storage medium according to claim 1. (3) A thin film made of at least one substance selected from oxide, nitride, carbide, or carbon is coated on a ferromagnetic metal thin film medium formed on a nonmagnetic substrate, and a liquid lubricant or A method for producing a magnetic storage medium, comprising the step of impregnating it with at least one solid lubricant. (4) A process of impregnating a thin film made of at least one substance selected from oxides, nitrides, carbides, or carbon with at least one liquid lubricant or solid lubricant using ultrasonic waves. 4. The method for manufacturing a magnetic storage medium according to item 3.