JPS58211323A - Formation of surface lubricating film of magnetic recording medium - Google Patents

Abstract

PURPOSE:To obtain a surface lubricating film nonsticking to a magnetic head and to enhance durability, by applying a solid surface lubricant in a heat melted state without using a solvent dilution method and thinning the coated film. CONSTITUTION:A magnetic disc is obtained by forming magnetic thin films 2 on both sides of a circular aluminum substrate 1 by a spin coating method or vapor deposition method or the like, and the lubricting film 4 is formed by coating the disc with a surface lubricant is a heat melted state. As the solid lubricant, higher aliphatic acid, its metal salt, aliphatic ester, etc. having >=45 deg. melting point are used. For example, the film 4 is formed by forming a gamma-Fe2O3 magnetic film on the substrate 1 by the sputtering method, heating the obtained sputter disc surface to 130-140 deg.C, and coating the surface with behenic acid heated to 110-120 deg.C, heating the surface of the medium to 110-120 deg.C, and wiping the surface with a roll of paper.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to a method for forming a lubricating film in Table 1m of a recording medium for an iJ magnetic disk.

(b) Background of the technology A magnetic disk is a recording medium in which N layers made of magnetic material are formed on the upper and lower surfaces of a disc-shaped aluminum alloy substrate approximately 2 mm thick. A magnetic head is held on a disk with a small gap therebetween, and information is recorded on a large number of tracks within the 4Ib, allowing random access.

Until now, the magnetic material that acts as a recording medium has been shaped like a sword.
Fe + O+ (iron r17) magnetic powder has been used. In other words, magnetic powder mixed with binder is
A recording 41 surface layer with a j17 of less than 1 μn1 has been produced and used by applying it onto a substrate using a coating method, a spray method, or the like.

In order to increase the bit density, we have to increase the thickness of the coating layer. ! When the /1 film is thinned, the reading output becomes low, the film strength decreases, and data loss caused by non-uniformity of the ζ film, which has not been a problem in the past, becomes noticeable.

- About the new Ken 11 powder and thin J conversion forming method
My research is 1” I/Koyu! k % Co-N1 (cobalt-nickel) or r-Fe+Oa can be coated with plating, vacuum evaporation, sputtering, etc. instead of conventional coating methods.
The pleural method has started to be used for magnetic phases such as ne.1.

Such a magnetic film has a film thickness of 0.05 to 02 .mu.n1, which is much thinner than the coating method, and is therefore suitable for high density.

Now, the loading and reading of information to the disk is carried out by moving back and forth along the surface of the magnetic disk, and is suspended by a distance of 0.1 to 0.5 μm due to the magnetic force exerted by the magnetic disk. C35) Take configuration (
In a 1-pressure disk drive, the magnetic head is in contact with the magnetic disk in a pinched manner, so there is a lot of friction; Contact with the magnetic disk 1fu due to the jump may damage the recording medium made of the magnetic film and cause it to peel off.

In addition, even when the magnetic head is operating with a floating height of 01 to 05 μm, if the magnetic head is covered with recording medium powder or dust (1J), the magnetic head will fall, and the impact and friction at that time will cause the recording medium to become damaged. There are times when there are four members.

Therefore, a protective film or a 1 to 4 m thick film is provided on the surface of the recording medium in order to reduce the contact resistance when the head comes into contact with the magnetic disk and to significantly increase the mechanical strength.

(c) Conventional technology + Problems 8111 and 1 show a typical example of a magnetic y1 disk, in which magnetic recording material a11 is formed on a disk-shaped aluminum alloy substrate l with a thickness of about 27 nm. The film 2 is formed by a spearfoot method, a vacuum evaporation method, a sputtering method, a plating method, or the like.

First in this
In order to increase fi, it is necessary to form the magnetic film 2 thinly, and in this respect, the vacuum 4'a+ 8.1 method, scring method, plating method, etc. are more effective than forming a coating film by the spearfoot method. It has also been put into practical use because of its advantages, such as the fact that the recording medium is formed continuously when viewed microscopically, and there is less noise.

Magnetic 1:12 Tame media include oxide-based media such as γFe+0+ and metal-based media such as Co-Ni alloy or CO-Cr alloy, but in the case of gold striped thread, the hardness is low and the hardness is low. The thickness is 10 because it is easily damaged by 8+ etc.
It is also possible to provide a non-magnetic filler with a thickness of about tJ ~2000λ (0.01-0.2 μm) as a fragility retaining layer.

Next 1c (1f:i l':l-membrane 2 tD upper K t
J', d:'a) A method is used in which a Pa film 4 is formed to reduce the friction between the magnet and the throat 3.

The non-explosion ψJ is caused by 1) the formation method of this dAI Pff film 4, and conventionally, when the liquid lubricant is formed, the solid lubricant is removed and the slippage 4 is formed.

In other words, a fluoride warp is used as the liquid binding agent, and in this case, 7F tends to stick to the magnetic head 3, and when a C8S configuration is adopted, 451 scratches are particularly likely to occur.

Furthermore, even when the lubricant film 4 is in a solid state, since IA was conventionally carried out using a solvent diluted method, there is residual solvent, which inevitably causes it to stick to the magnetic head 3, and the adhesive strength with the substrate deteriorates. If the heat treatment is performed to remove the solvent, the lubricant film 4 will be damaged by the evaporation of the solvent, which will impair the continuity of the film and reduce the strength and durability of the lubricant film 4.
There was a drawback that the value decreased.

((I) Purpose of the Invention The present invention provides a surface iNi lubricant film that maintains strong contact with a magnetic film or a magnetic film provided thereon to prevent film breakage, has excellent durability, and does not stick to a magnetic head. The purpose is to provide a method for forming.

(e) Structure of the Invention The purpose of "Unexploded W" is to apply a solid surface lubricant in a heated and molten state without using a solvent dilution method to form a film.I)J
can be achieved.

(, f) The embodiments of the invention are suitable, such as myristic acid (melting point 53.8 °C), copper stearate (115-120 °C), mago myristate, num L 131.6 °C), etc. 0 To apply these solid lubricants to the magnetic film on the substrate or the image retention film provided thereon, the solid lubricant must be heated to a temperature higher than its melting point, preferably 20 to 100°C. It is formed using any conventional coating film forming method such as a spin code method, a dipping method, or a spray method in a heated state.

However, in order to increase the contact force with the substrate, it is effective to heat the substrate and form a coating film in a strip-like manner.

However, the thickness of the coating film formed in this way is much thicker than the target 1"J film of several molecules of JNiNr, and is not suitable for JIA.

So 7L and the board r I used IIJ for this? ; Heating at 1 above the melting point of the T agent and wiping off the excess moisture to make the II body approximately several molecular layers thick.

In the following, for every 2+3 real h1μ example, the effect of 1 tree up 6ψ will be removed from W4.

Example-1 γ was deposited on a substrate using a sprinkling method and a heat treatment for alcoholization.
-The surface of the Subanota disk on which the Fe+O+ magnetic film was formed was heated to 130-140°C, and the
Behenic acid heated to 0 to 120°C was applied using the Subin coat method. Next, the medium was heated to 110-120'' CK while the surface of the medium was wiped with a roll of paper to form a lubricating film.

Example 2 On the surface of the Menki disk on which the Ni-Co magnetic film was formed by the Menoki method, an oxidized layer of {L1:Sin. y-ru {i = 130-140°C, and spin coated (j.
(While heating the media to a temperature of 4.5 C, the surface of the medium was wiped with a roll of paper to form a 4'51 synovial membrane.

Example 3 The surface of the Menogi disc manufactured in the same manner as Example 2 was
It was heated to 0 to 130°C and then melted to 140°C. A wet film was formed by immersing the sample in a copper stearate bath and wiping it off with a roll of paper.

The surface of the spanota disk made in the same manner as in Example 1 was 8
Heat the stearic acid to 0-90°C, then use a K sprayer to remove the stearic acid heated to 80-90°C. In particular, a lubricating film was formed.

The 41'1 film formed by the above method has a thickness of just a few molecules and has good adhesion to the substrate, while not adhering to the magnetic helix.

Actual MII Example 5 Co-Cr magnetic {jl:. 'UBiL,
After applying 4 coats of cloth, heat the media surface to 80 to 90°C and wipe with a roll-shaped beaver (N':31VI film).
b completed.

Furthermore, 113 physical K hardness, friction coefficient and durability t'J
-, compared with that obtained by the conventional solvent-diluted 1' method, it is extremely superior as shown in the table.

Here, the adhesion value was determined by visual inspection of the presence of adhesion after the Taberfuranoto type ferrite head was brought into contact with the simple synovial membrane Im1 for 811-"j11{1}, and the friction value was determined to be 2.
5. ? Alumina henode pressurized to 40-60c per second
The coefficient of friction when contacting and sliding at 500 m was compared, and the durability was compared by the number of times until scratches appeared after sliding up to 5,000 times under the same conditions as in the seat friction measurement.

(jJ) Effects of the Invention The present invention directly forms a surface moistening Mj film provided on the magnetic film of a magnetic disk by melting.
By carrying out this method, it was possible to put into practical use a highly durable surface synovial membrane that does not have adhesion to magnetic henodes, has a low abrasion coefficient, and is durable.

[Brief explanation of the drawing]

Figure VI is a configuration diagram explaining the Jil construction of a magnetic disk.
, 3t.

Claims (1)

[Claims] 1. Provided on a non-magnetic substrate. Magnet 1'l: Formed on the layer, used to record information by washing the magnetic head and
The surface retention film that prevents the retention of the magnetic layer during the formation is formed on the surface from the melt without using the solvent method, and is thinned out using the Butsu wiping method. A method for simulating surface lubrication of magnetic recording media.