JPS6196512A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To improve the corrosion resistance of a protective carbon layer and to obtain a recording medium having a lowered coefft. of friction by forming a lubricating layer on the carbon layer formed on a thin metallic film as a magnetic recording layer so that part of the org. solid or liq. lubricant is filled into the pores in the carbon layer. CONSTITUTION:A lubricant having >=50 deg.C m.p. such as paraffin, higher fatty acid, higher fatty acid ester or amide or higher alcohol or a liq. lubricant such as fluorocarbon is dissolved in an org. solvent or diluted with a solvent and applied to a carbon layer formed as a protective layer 2 on the surface of a thin ferromagnetic metallic film formed as a recording layer 3 on a substrate 1 to form a lubricating layer 1 on the carbon layer 2. At this time, part of the lubricant is filled into the pores in the carbon layer 2. The corrosion resistance of the magnetic metallic layer is improved, and a magnetic recording medium having superior wear resistance and traveling performance is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic recording medium used in a magnetic recording device widely used as an external storage device for computers.

[Conventional technology]

A magnetic recording medium with a four-metal film as a recording layer has sufficient mechanical reliability to withstand contact with the head.
It is necessary to form a protective film having corrosion resistance to protect the thin metal PA from corrosion.

Conventionally, metal layers such as Rh, Or, N1-P, and Av are formed, and %Si, N, 1. Ag, O,...
Oxides such as WC, Ti(!, SiO, E, (:!), etc.
Carbides and nitrides have been proposed as protective layers. However, these are extremely susceptible to scratches and have many problems with adhesion, oil lubricity, and reproducibility.

On the other hand, in recent years, carbon films have been proposed as a protective M[[[[], and relatively good results have been obtained. As a forming method, a sputtering method is used, and good reproducibility is obtained. Furthermore, the reliability of contact with the head is satisfied to some extent, and it has become mainstream as a protective film for metal-based media.

[Problem that the invention seeks to solve]

However, as the carbon film becomes thinner, bores are present, which causes pitting corrosion in the presence of moisture.

Furthermore, since the carbon film is electrically conductive, it has the disadvantage of undergoing galvanic corrosion processes.

In addition, although the carbon film has a small friction coefficient compared to the friction between metal and the head, it cannot be said to be sufficiently small, and the coefficient of friction fluctuates considerably, making it possible to improve mechanical contact with the head. Therefore, the present invention is intended to solve these problems.The purpose of the present invention is to improve the corrosion resistance of the carbon film protective film, as well as improve the coefficient of friction and provide a highly reliable carbon film. [Means for Solving the Problem] The present invention aims to provide a metal thin magnetic recording medium. [Means for solving the problem] The present invention provides a magnetic recording medium that can be used after the entire metal magnetic 1# is formed, after the carbon protective film is directly formed, or after the intermediate 11i such as Or is formed. After forming the carbon protective film via the carbon protective film, an organic solid lubricant layer or liquid lubricant layer 1- is formed.

Any type of organic solid lubricant may be used as long as it has a melting point of 50°C or higher and has excellent lubricity. Examples of compounds without polar groups include hydrocarbon compounds such as paraffins and olefins; examples of compounds with polar groups include carbon membranes.
8 or higher fatty acids, metal salts of higher fatty acids, higher alcohols, esterification products of higher fatty acids and higher alcohols,
There are ^-class amines, etc.

As the liquid lubricant layer, a fluorocarbon oil lubricant or the like is suitable.

Formation methods include dissolving or diluting the lubricant in an organic solvent, spin code method, and dipping method.

Use a spray method, etc.

FIG. 1 shows the configuration of the present invention. 1 is an organic solid lubricant layer or a liquid lubricant layer, 2 is a carboxylate layer, 3 is a magnetic layer, and 4 is a substrate.

[Example 1] A plated hard disk medium with carbon protection N (5ooX) formed by sputtering was used as a comparison sample, and stearyl alcohol (claRsyOE) was used as the solid lubricant in this example. Stearyl alcohol was diluted to 11 wt % with isopropyl alcohol, and a film was formed using a spear coating method.

The coefficient of dynamic friction of the carbon layer alone -c' was changed to Cl3, and its fluctuation was (from L1 or more to αo5 or less).

For corrosion resistance, the sample was immersed in pure water at 50°C for 24 hours.
The change in magnetization over time was measured by VSM, and it was found that the carbon layer alone had a decrease of 22 degrees, but the decrease was 8%.

[Example 2] The comparative sample used in Example 1 was coated with perfluoroalkyl ether (trade name: Krytx 15) as a liquid lubricant layer.
875M was used. This was diluted to 1 wt% with fluorine-chlorine solvent (trade name: DiFlono S2), and this was prepared using the spin code method.

The coefficient of dynamic friction was Cl15, and its fluctuation was 0.02 or less.

Regarding corrosion resistance, 5% (
He became a senior.

〔Effect of the invention〕

The results of the Examples are summarized in Table 1.

The coefficient of friction (Fi) and its fluctuations decreased significantly, and even when tested in a contact start-and-stop (aSS) test, an improvement in durability was observed.

Table 1 Regarding corrosion resistance, organic solid or liquid lubricant layer penetrated into a portion of the bore of the carbon layer, resulting in a significant improvement in corrosion resistance.

As described above, the present invention has been developed to create a magnetic recording medium having a metal layer as a recording layer, which has sufficient mechanical reliability to withstand contact with the head and protects the metal layer from corrosion. A protective film with corrosion resistance could be obtained.

Although the embodiments have been described with respect to plated hard disk media, the effects of the present invention are also the same with media in which a magnetic film is formed by sputtering. Furthermore, the same effect is obtained even when the layer phase is flexinople media.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of the present invention. 1 is an organic solid lubricant layer or a liquid lubricant layer, 2 is 1ii% carbon, 5 is a magnetic layer, and 4 is a base plate. Above 2-De-1 Figure 1

Claims (1)

[Claims] A magnetic recording medium having a thin metal film as a recording layer is characterized in that after carbon is formed as a protective layer, an organic solid oil lubricant layer or a liquid oil lubricant layer is formed, and a portion of the layer is impregnated into the bore portion of the carbon layer. magnetic recording media.