JPH01178120A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To improve durability and corrosion resistance by incorporating a lubricating agent or rust inhibitor into the many fine pores of a magnetic layer. CONSTITUTION:An anodized film 5 which is formed by anodizing a thin film of aluminum or aluminum alloy and has the many fine pores is provided directly or via a nonmagnetic underlying layer on a nonmagnetic substrate 6. The magnetic layer 3 consisting of a thin ferromagnetic metallic film is formed on the anodized film 5, by which the magnetic layer 3 having the fine pores is formed. At least one kind of the lubricating agent 1 or the rust inhibitor is impregnated into such fine pores. A proper amt. of the lubricating agent or rust inhibitor is, therefore, supplied always to the surface part of the magnetic recording medium. The durability and corrosion resistance are thereby improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic recording medium, and more particularly to a magnetic recording medium whose magnetic layer is a ferromagnetic metal thin film having excellent durability and corrosion resistance.

[Conventional technology]

Many magnetic recording media that are currently in circulation are coated magnetic recording media that are manufactured by dispersing magnetic powder in a binder and coating it on a substrate. This coating type magnetic recording medium maintains good durability by containing a lubricant in a binder containing magnetic powder.

For example, magnetic recording media in which a porous magnetic layer composed of an epoxyphenol-based thermosetting resin and inorganic particles is impregnated with a lubricant (Japanese Patent Application Laid-Open No. 104202/1982), liquid paraffin, etc. A method for obtaining a porous magnetic layer with excellent lubricity by adding organic additives to magnetic paint and thermally decomposing and evaporating the additives during the coating film curing (Japanese Patent Laid-Open No. 56-3
435, No. 59-96701), and recently, regarding high-density magnetic recording media using thermoplastic resin suitable for floppy disks, a magnetic recording medium in which a lubricant is contained in the undercoat layer (Japanese Patent Laid-Open No. 61 -73235 publication)
Many other proposals have been made.

In contrast, in recent years, ferromagnetic metal thin film magnetic recording media, which have been actively researched and put into practical use because they have excellent magnetic properties suitable for high-density magnetic recording, have a magnetic recording layer ( Since the magnetic layer (magnetic layer) is made of metal, a lubricant cannot be contained in the magnetic layer. For this reason, various lubricants and the like are applied to the surface of the magnetic layer in an attempt to improve the durability of the magnetic recording medium. However, by simply applying lubricant, the lubricant layer peels off due to sliding contact with the magnetic head, making it impossible to obtain sufficient durability.

[Problem to be solved by the invention]

As mentioned above, conventional ferromagnetic metal thin film type magnetic recording media have a problem in that it is difficult to stably retain lubricants, anti-corrosion agents, etc. on the surface of the magnetic layer, and as a result, durability is poor.

An object of the present invention is to solve the problems of the prior art described above, and to provide a highly reliable ferromagnetic metal thin film type magnetic recording medium that retains lubricant and anti-corrosion agent very well, has excellent durability and corrosion resistance, and is highly reliable. It is about providing.

[Means to solve the problem]

The object of the present invention is to provide a thin film made of aluminum or an aluminum alloy on a non-magnetic substrate, perform an anodic oxidation treatment on the thin film to form an anodic oxide film having many fine pores, and then perform vapor deposition. A magnetic layer made of a ferromagnetic metal thin film is formed by a method, and the inner diameter of the magnetic layer is 50 mm.
This is achieved by forming a large number of fine pores of about 2,000 to 2,000 pores, and impregnating a lubricant or an anti-corrosion agent into the large number of fine pores.

That is, in the magnetic recording medium of the present invention, a thin film made of aluminum or an aluminum alloy is deposited on a non-magnetic substrate directly or through a non-magnetic underlayer by vacuum evaporation,
It is formed by a vapor deposition method such as sputtering method or ion blasting method, and then anodized to form an anodic oxide film made of aluminum or aluminum alloy with many fine pores. A magnetic layer made of a ferromagnetic metal thin film is formed on top of the magnetic layer by a vapor deposition method, either directly or through a crystal orientation control film of a magnetic layer such as Ti, Ge, Or, etc., thereby forming a large number of fine pores. forming a magnetic layer;
At least one of a lubricant and an anti-corrosion agent is impregnated into the large number of fine pores, or Si is impregnated on the magnetic layer.

After providing a hard protective film such as B or C, a magnetic recording medium is prepared in which a lubricant or anti-corrosion agent is impregnated into the large number of minute pores. An appropriate amount of lubricant or anti-corrosion agent is always supplied, further improving durability and corrosion resistance.

In the magnetic recording medium of the present invention, commonly used lubricants and anti-corrosion agents can be suitably used, and the types thereof are not particularly limited.

In the magnetic recording medium of the present invention, the ferromagnetic metal material constituting the magnetic layer may include single metals such as Co, Ni, and Fe, or alloys thereof, as well as Fe-9i and Fe-R.
h, Fe-V, Fe-Ti, Co-P, Co-B, Co
-Ti, Co-Fe, Co-Pd.

Co-5i, Co-V, Co-Y, Co-3m, Co-
Mn, Go-Ni, Co-N1-P, Go-Ni-B.

Co-Cr, Co-Ni-Cr, Co-Ni-Ag, C
o-Ni-Pd, Co-Ni-Zn, Co-Cu, Co
-Ni-Cu, Co-W, Co-N1-W, Co-Fe
-Cr.

Go-Mn-P, Go-8m-Cu, Co-N1-Zn
-P, Co-V-Cr, etc. can be suitably used.

Further, the magnetic recording medium of the present invention is a synthetic resin film such as polyethylene terephthalate, polyester, polyimide, polyamide, polyvinyl chloride, etc., or a film containing SL, Cu, Ti, or Fe in these.

Substrates mixed with AQ, Cr particles, or their oxide particles, or graphite, molybdenum disulfide, carbon fiber, etc., as well as substrates made of AQ, Af1 alloy, Ti, Ti alloy, Cu, Zn, etc., glass, etc. Tape based on inorganic material.

It can be applied to magnetic recording media such as sheets, cards, disks, drums, etc. that have a structure that makes sliding contact with a magnetic head.

〔Example〕

An embodiment of the present invention will be described below in more detail with reference to the drawings.

(Example 1) The floppy disk shown in FIG. 1 was manufactured by the procedure shown below.

Using 99.9% high purity AQ as the evaporation source material, a polyimide film with a thickness of 50/711 was fabricated by a batch vacuum evaporation method.
A film with a thickness of 0.2. An AQ deposited film of m was formed. The evaporation conditions at this time were a vacuum level of 5 x 10” Torr and a film formation rate of 20 people/deposition.
It was S. Next, the surface oxide layer of the above AQ vapor-deposited film was removed by immersing it in a 5 wt% (weight) sodium hydroxide solution, and after washing with water, it was neutralized with a 5 mol% nitric acid solution, and after washing with water, a 1 mol. Anodizing was performed in a solution of sulfuric acid with a concentration of /Q and aluminum sulfate of 5 g/Ω, and the thickness was 0.
．． An anodic oxide film 5 of AQ 2- was formed. This is 1
The anodic oxide film 5 of AQ was immersed in a phosphoric acid solution of 5% by weight.
We carried out processing to enlarge the bore diameter of the fine holes formed in the . Next, by a batch vacuum evaporation method, a 0.02-thick Ti base layer 4 was formed on the Afl anodic oxide film 5 using 99.9% high purity Ti as an evaporation source material.

On top of that, as a Co90 wt%-CrlOwt% gold alloy deposition source material, a thickness of 0.2. Co80wt%-
A Co--Cr magnetic layer 3 made of a 20 wt % Cr alloy was formed, and a Si protective film 2 with a thickness of 0.027 m was formed thereon using 99.9% high purity Si as an evaporation source material.

The above film forming conditions are as follows: degree of vacuum during evaporation: 5XIO-'T o
rr, the substrate temperature immediately before deposition is 150°C, and the film formation rate is:
They were 10 people/s, 50 people/s, and 10 people/s, respectively.

The magnetic film produced in this way was coated with 0.1% of the lubricant Fow+brin DOL (trade name manufactured by MONTE FLUO3).
After immersing the lubricant in wt% diluted solution (using Freon as a solvent) and allowing it to fully penetrate into the fine pores formed by the anodizing treatment of Ω above, remove the excess lubricant by shaking it off with a spinner. A 5-inch diameter floppy disk having a cross-sectional structure shown in FIG. 1 was prepared by forming a lubricant layer 1.

(Example 2) Using the vacuum evaporation apparatus shown in FIG.
A 0.2-thick AQ vapor deposited film was formed.

The degree of vacuum during vapor deposition was 5 x 10-' Torr, and the film-forming rate was 200 people/s. Next, this AQ vapor-deposited film was processed to a thickness of 0.05 mm using the anodization apparatus shown in FIG. 2-
An anodic oxide film of AQ was formed. Next, using the same anodic oxidation apparatus shown in FIG. Using the vacuum evaporation apparatus shown in the figure, Co80 with a thickness of 0.2-
A magnetic layer of wt%-Ni20 wt% was formed. The degree of vacuum during vapor deposition was 5×10 −′ Torr + the film formation rate was 1000 people/S. A 0.5 wt % diluted solution of oleylamine (methyl isobutyl ketone was used as a solvent) was applied to the magnetic film produced by the above procedure to produce a magnetic tape having the cross-sectional structure shown in FIG. 5.

(Comparative Example 1) A 5-inch diameter floppy disk was produced in the same manner as in Example 1, except that the anodic oxidation treatment of the deposited film of A and the bore diameter enlargement treatment were not performed.

(Comparative Example 2) A magnetic tape was produced in the same manner as in Example 2, except that the anodic oxidation treatment of the deposited film of A and the bore diameter enlargement treatment were not performed.

What is the durability of the magnetic disks and magnetic tapes produced in the above Examples and Comparative Examples?

Corrosion resistance is evaluated by the number of times a commercially available 5-inch diameter floppy disk is slid repeatedly until the playback output drops by 2 dB from the initial value.
5o21 PPmp H2S at 5°C and 75% RH
1 in an atmosphere containing 0.5 ppm, NOx I PPm
The amount of sulfur infiltrated into the magnetic layer after being left for 00 hours was measured and evaluated by XMA (X-ray microanalyzer) analysis. The results are shown in Tables 1 and 2.

As is clear from Tables 1 and 2, it can be seen that the 5-inch diameter floppy disk of the present invention has a significantly increased number of sliding operations and is further superior in durability. Further, as is clear from Table 2, the magnetic tape of the present invention has a small amount of sulfur penetrating into the magnetic layer, and has extremely excellent corrosion resistance.

〔Effect of the invention〕

As explained in detail above, by forming a ferromagnetic metal thin film on the anodic oxide film having many fine pores formed by anodizing the aluminum or aluminum alloy thin film of the present invention, A magnetic recording medium made of a ferromagnetic metal thin film in which a magnetic layer with pores is formed, and a lubricant or an anti-corrosion agent is impregnated into the many fine pores has superior durability and corrosion resistance. , an extremely reliable magnetic recording medium can be obtained.

[Brief explanation of the drawing]

1@ is a schematic diagram showing the cross-sectional structure of the floppy disk manufactured in Example 1 of the present invention, FIG. 2 is a schematic diagram showing the structure of the vacuum evaporation apparatus used in Example 2 of the present invention, and FIG. A schematic diagram showing the structure of the AQ anodizing device used in Example 2, FIG. 4 is a schematic diagram showing the structure of the vacuum evaporation device used in Example 2, and FIG. 5 shows the magnetic tape produced in Example 2. FIG. 2 is a schematic diagram showing the cross-sectional structure of the 1...Lubricant 2...Si protective film 3...
Co-Cr magnetic layer 4...Ti underlayer 5...anodized film 6...substrate 7...supply roll 8.
... Auxiliary roll 9 ... Rotating drum 10 ... Winding roll 11 ... AQ evaporation source 12 ... Electron gun 13 ... Power supply roll 14 ... Cathode plate 15-C
o-Ni evaporation source 16-Co-Ni magnetic layer 17... Anti-contract agent Patent attorney Junnosuke Nakamura Figure 3 Figure 4

Claims (1)

[Claims] 1. An anodic oxide film with fine pores formed on a non-magnetic substrate by anodizing an aluminum or aluminum alloy thin film directly or through a non-magnetic underlayer. By forming a magnetic layer made of a ferromagnetic metal thin film on the anodic oxide film, a magnetic layer having fine pores is formed, and a lubricant and anti-corrosion agent are added to the fine pores. A magnetic recording medium characterized in that it is impregnated with at least one kind of. 2. The magnetic recording medium according to claim 1, further comprising a crystal orientation control film for controlling crystal orientation of the magnetic layer provided on the anodic oxide film. 3. The magnetic recording medium according to claim 1 or 2, characterized in that a protective film is provided on the magnetic layer.