JPH02173929A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To give no mechanical damage to a ferromagnetic metal medium and to avoid an increase of coefft. of friction on contact-start-stop (CSS) with a magnetic head using a hard slider by forming a condensation polymerization film of silicon compd. and covering the film with org. fluorocompound. CONSTITUTION:On a ferromagnetic metal thin film medium formed on a nonmagnetic substrate, a thin film comprising carbide and carbon material and a smooth oxide are deposited. Then the condensation polymerization film of silicon compd. and the org. fluorocompound are deposited thereon. The carbide or carbon material film absorbs the shock caused by a magnetic head and the smooth oxide has excellent lubricating property. The condensation polymerization film of silicon compd. enhances the adhesion strength of the metal thin film and the lubricant. The org. fluorocompound has excellent lubricating property. Thereby mechanical reliability of the medium is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a magnetic storage medium comprising a strong penta-f1 metal thin film provided on a non-magnetic substrate.

[Prior Art] It is essential for a magnetic storage medium having a metal medium to have mechanical reliability sufficient to withstand contact with a magnetic field.

The magnetic storage medium has a contact start-stop method (hereinafter abbreviated as C5S method) due to a simplified drive configuration.
In addition, in order to protect the magnetic recording surface, the C8
S is 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 have been methods for providing an organic lubricating layer such as saturated fatty acids on the surface of a metal 61-based medium (Japanese Patent Publication No. 56-30609) and a method for providing a mixed lubricating layer of fatty acid amide and phosphorus compound (Japanese Patent Publication No. 59-165238) for higher fatty acids. There is a method of providing a mixed lubricating layer of a fatty acid metal salt (Japanese Patent Publication No. 59-177728), but C8S with a magnetic head having a highly hard slider has problems such as an increase in the coefficient of friction 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 there is no deterioration in magnetic properties. 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 scraped and the coefficient of friction increased.

[Problems to be Solved by the Invention] As mentioned above, in the prior art, sufficient mechanical reliability could not be obtained in C8S with a magnetic head having a highly hard slider, and an increase in the coefficient of friction could not be suppressed.

The present invention is intended to solve these problems, and its purpose is to avoid mechanical damage to a strong 5n metal medium even in C8S in a magnetic head with a highly hard slider, and to reduce the coefficient of friction. It is an object of the present invention to provide a magnetic storage medium that does not increase

[Means for Solving the Problems 1] The magnetic storage medium of the present invention comprises a ferromagnetic metal medium formed on a non-magnetic substrate, coated with a thin film of carbide and carbon substances and a slippery oxide, Next, a polycondensation film of a silicon compound is coated, and a fluorinated organic substance is further coated.

Cr, Ti, Ta, and Nb are coated in order to further ensure the adhesion between the ferromagnetic metal medium and the carbide and carbon, and a film thickness of 50 to 100 is sufficient.

The carbon may be diamond-like, graphite-like, or amorphous, and the film thickness is 150 to 800.

The lubricating oxide is mixed with carbon or formed on the carbon film. 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.

Next, a silicon compound having an alkoxy group on one side of the molecule and at least one functional group of an amino group or an imino group on the other side is defined as HJ-(CHil 2-NH-(CHtl 3-3i-
(OCH315HJ-(CHal 2-NH-(CH2
15-3i-(OCHs) 2N3 H2N-(CH2+ 2-NH-(CH-+ 2-NH
-fcH-)-3i-fOcH-13, which is diluted with a soluble solvent, applied by a known method such as a spray method, spinner method, dipping method, or pyrosol method, and then condensed by baking. Forms a film. There are no particular restrictions on the solvent; alcohols and halogenated hydrocarbons are used, and the concentration is determined depending on the desired film thickness. Further, baking at 60 to 200°C for 5 to 20 minutes is sufficient.

As for the film thickness, it is effective even with a few people (monolayer), and there is no problem even with a thicker film.

Perfluoropolyethers having a carboxyl group or a derivative thereof in the molecule are represented by Fomblin Z-DEAL and Z-DIAC manufactured by Montegisson, and these are Z-D.

It may be used in combination with the L and AM series.

Further, perfluoropolyethers having a carboxyl group or a derivative thereof at one end of the molecule or at the center of the molecule as shown below are used.

Here R is -CL H,. 1 or -CzFi or
and Rfl is -CF20- fc2F, ol. -fcF,o
l, -CF2- to Rtz -(:F20- fc2F
,01,-f(:F20+ ,-C:F-, l
, Ill + II are integers of 1 or more.

These can be diluted with a fluorine-based solvent and applied by a spinner method or a dipping method. The film thickness is sufficient for 10 people to be effective.

[Function] Carbide and carbon formed on a strong metal medium have the function of buffering the impact of a magnetic head, but in C8S with a magnetic head that has a highly hard slider, the carbonaceous film will be scraped. Therefore, lubricating oxides (PbO,
CdO, SbiOx) are mixed or stacked. A polycondensation film of a silicon compound having an alkoxy group and at least one functional group such as an amine group or an imino group on the other hand is formed, thereby increasing the adhesion strength between the thin film and the lubricant. Alkoxy groups are OH groups present on the nitrogen oxide film and the outermost surface of carbon, C0
0) Forms a thin film with strong adhesion through a dehydration condensation reaction with the (group) and the OH group on the surface of the metal medium in the pinhole part.On the other hand, the amino group or imino group is combined with the carboxyl group of the fluorinated organic substance described below. It exhibits strong anti-corrosion properties, has the effect of preventing fluorinated organic substances from being easily removed due to impact abrasion of the head, and has a high trapping effect on corrosive factors such as chlorine (and exhibits anti-corrosion effects).

The fluorinated organic substance of the present invention is widely used as a lubricant for coated media, and exhibits excellent lubrication performance unless removed from the surface of the storage medium.

As a result of the above, mechanical reliability has been significantly improved.

Next, examples will be specifically explained.

[Example 11: Approximately 15 μm of N1-P alloy plating was applied as non-magnetic alloy plating to a mirror-finished disc-shaped aluminum alloy substrate.
After plating to a thickness of m, the plate was polished to a thickness of 10 μm and a surface roughness of 0.03 μm or less, and then a Co-N1-P alloy was plated to a thickness of about 0.06 μm as a metal 6f1 thin film.

Next, 100 Cr films and 300 amorphous carbonaceous films were successively formed by magnetron sputtering. Furthermore, 100 layers of PbO were formed by magnetron sputtering.

Next, the silicon compounds shown in Table 1 were dissolved in Guiflon S-3 solvent at a concentration of 0.0 OIW/V%, and the dipping method (l
Oam/min), then 110°C
Baked for 5 minutes.

Furthermore, the fluorinated organic substances shown in Table 1 were added to Guiflon S-
3 at a concentration of 0.03 W/V% and dipping method (
10 cm/min), and then heat-treated at 90° C. for 10 minutes.

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

Next, an amorphous carbonaceous film was successively formed using Nb by 100 people and 300 people using a magnetron sputtering device. Furthermore, 50 CdOs were formed by magnetron sputtering, and then the silicon compounds shown in Table 1 were added to Guiflon S-3 solvent.
．． 002W/V% concentration and dipping method (10
cm/min) and then baked at 110°C for 10 minutes.

Furthermore, the fluorinated organic substances shown in Table 1 were added to Guiflon S-3.
．． Dissolved at a concentration of 0.02W/V% and dipping method (10c
m/min) and then heat-treated at 90°C for 10 minutes.

[Example 31 A disk having a metal medium was produced in the same manner as in Example 1.

Next, 50 T1 layers and 50 Ta layers were formed using a magnetron sputtering device.

Furthermore, 800 pieces of amorphous carbonaceous film and Sbz O3 were mixed using a magnetron sputtering device. Next, the silicon compounds shown in Table 1 were added to Guiflon 3-3 solvent with O,0
Dissolve at OIW/V% concentration and dipping method (10 cm
/min) and then baked at 110'C for 10 minutes.

Furthermore, the fluorinated organic substances shown in Table 1 were dissolved in Guiflon S-3 at a concentration of 0.05 W/V%, and the dipping method (10
cm/min), then at 90°C for 10 minutes.
Heat treated.

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

Next, the graphite-like carbonaceous film was acidified using a magnetron sputtering device using a mixture of 500 people and 200 people of CdO. Next, the silicon compounds shown in Table 1 were added to Guiflon S-3 solvent.
．． 002W/V% concentration and dipping method (10
cm/min) and baked at 110°C for 15 minutes.

Furthermore, the fluorinated organic substances shown in Table 1 are added to Guiflon 5-3j:
0. Dissolved at IW/V% concentration and dipping method (10a
m/min) and then at 80°C for 10 minutes.
Heat treatment was performed.

[Comparative Example-1] A sample was prepared in Example 1 without sprinkling PbO.

[Comparative Example-2] A sample was prepared in Example 2 without sprinkling CdO.

[Comparative Example-3] A sample was prepared in Example 3 without sputtering Sb203.

[Comparative Example-41 A sample was prepared in Example 4 without using the fluorinated organic substance.

[Comparative Example-5] A sample was prepared in Example 4 without using the silicon compound.

The disks of the above Examples and Comparative Examples were subjected to a C8S test. C
In the SS test, the static friction coefficient was measured before C8S and after C5520000 times using a thin film head made of alumina titanium carbide as a slider material with a flying height of 0-20 um and Hv1200. The results are shown in Table 2.

The present invention can also be applied to floppy disks, magnetic tapes, and magnetic cards, and the same effect can be achieved even when the substrate material is glass or plastic.

Effects of the invention as shown in Table 1, Table 2] As described above, according to the present invention, by forming a polycondensation film of a silicon compound and coating the fluorinated organic substance thereon, the fluorinated organic substance is removed by impact abrasion of the head. The coating is not easily removed (and also has an extremely excellent effect on corrosive factors).

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Claims (5)

[Claims] (1) A thin film of carbide and carbon and a slippery oxide are coated on a ferromagnetic metal thin film medium formed in the shape of a nonmagnetic substrate, and a polycondensation film of a silicon compound is coated thereon,
A magnetic storage medium further characterized by being coated with a fluorinated organic substance. (2) The magnetic storage medium according to claim 1, wherein the polycondensation film of the silicon compound has an alkoxy group on one side of the molecule and at least one functional group of an amino group or an imino group on the other side. . (3) The magnetic storage medium according to claim 1, wherein the fluorinated organic substance is a perfluoropolyether containing at least a carboxyl group or its dielectric in its molecule. (4) The lubricating oxide is PbO, CdO, Sb_2O_
3. The magnetic storage medium according to claim 1, wherein the magnetic storage medium is 3. (5) Cr, Ti, Ta,
2. The magnetic storage medium according to claim 1, further comprising a coating formed of at least one substance selected from Nb.