JPS60157725A - Magnetic storage medium - Google Patents

Abstract

PURPOSE:To prevent deterioration in the wear resistance of a magnetic storage medium even after exposure to an environment at high humidity by forming a cross-linked protective film of hydrocarbon on the surface of the storage medium having a ferromagnetic metallic thin film on the substrate. CONSTITUTION:A cross-linked protective film of hydrocarbon is formed by subjecting gaseous satd. hydrocarbon to plasma decomposition and polymn. or a carbon target to bias sputtering in an atmosphere contg. gaseous hydrocarbon. The protective film is very hard and has a very low coefft. of friction even after exposure to an environmemt at high humidity, so when the film is formed on a magnetic storage medium, it shows especially superior function as a protective film. The thickness of the protective film is <=2,000Angstrom , preferably <=1,000Angstrom . A protective film of >2,000Angstrom thickness increases the spacing loss.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a magnetic storage medium that exhibits excellent abrasion resistance even when exposed to humid conditions. The present invention relates to a magnetic storage medium in the form of a disk, drum, or disk used for recording or recording.

In recent years, with the aim of improving recording density, iron, cobalt,
Magnetic storage media have been proposed in which a thin ferromagnetic gold ingot film made of nickel or an alloy thereof is deposited on a substrate by vacuum deposition, sputtering, or plating. These four gold bullion magnetic storage media have excellent recording density, but when used in recording and reproducing devices, they run at high speed while physically contacting the magnetic head, so they have excellent wear resistance. It's not practical.

In order to improve wear resistance, liquid or solid hydrocarbons such as paraffin are coated on the surface of the strong metal.
It has been proposed to apply a lubricant or to form a thin film by vacuum ablation.

The hydrocarbon 9f film formed by these coating methods or the vacuum boiling method is not cross-linked and is soluble in bath additives, so its abrasion resistance under normal conditions is 9, but even when exposed to humidity. It has the disadvantage that after being exposed to such conditions, its wear and tear deteriorates significantly.

In order to remedy these shortcomings, the present inventors have conducted research on rice milling and the protection of magnetic storage media by cross-linking hydrocarbons at high elevations or by using them under humid conditions. The present invention was arrived at based on the knowledge that the wear resistance does not deteriorate even in the case of abrasion resistance.

That is, the present invention is an 8B magnetic storage medium in which a crosslinked hydrocarbon protective film is formed on the surface of a magnetic storage medium in which a ferromagnetic metal layer is provided on a base.

The present invention will be further explained in detail below.

In the present invention, the cross-linked hydrocarbon-retaining H1 layer (hereinafter referred to as a protective film) refers to the image plasma decomposition polymerization of saturated hydrocarbon gas, or the method of slapping a carbon target in an atmosphere containing hydrocarbon gas. It can be formed by

The protective film according to the present invention is not bathed in bath agents, and its infrared spectroscopic analysis shows that absorption peaks of C-H bonds exist, and its elemental analysis shows that an aqueous system with a molar ratio of O/[() of 50150 or less It is true that there are words.

As the aqueous content decreases, the hardness of the film increases as well as its circular stress and dynamic friction coefficient. Therefore,
As a protective group for magnetic storage media (Y, C/H molar ratio 5
Range 0.0150 to 98/2. ) is preferred, and a particularly preferred range is from 60/4Ll to 91J/10
It is.

The protective film is particularly good as a protective layer when laminated onto a magnetic storage medium because it is very hard even after exposure to high humidity conditions and still has a very low coefficient of friction. When using products other than those of the present invention under high humidity conditions, in practical use, the film thickness should be maintained at 1°, preferably 20 mm or less, and particularly preferably 10 mm or less. Yes, if the thickness is greater than that, the spacing loss will increase.

A method for assembling the product of the present invention will be explained.

Specifically, the apparatus produced by the protection group according to the present invention includes an ionized plasma separation apparatus and a bias sputtering apparatus.

FIG. 1 is an explanatory diagram of an ionization plasma decomposition device. The reaction vessel 4 is arranged in a central manner with an air tank held on a reaction vessel stand, and the reaction vessel stand 5 is provided with a hydrocarbon gas supply port 6 and an exhaust port 1f7 connected to an exhaust pump. There is. In addition, plasma is generated in the reaction vessel 4 by electrodes 2 and 3, and the same potential as that of the electrode 2 is applied to the magnetic storage medium having a protective film layer 7L placed on the electrode 2. A protective film is formed on a magnetic storage medium by ionization plasma decomposition polymerization.

FIG. 2 is an explanation Q of the bias sputtering device.

The reaction vessel 14 is configured to be airtight, and is provided with a hydrocarbon gas supply port 15 and an exhaust pipe 16 connected to an exhaust pump. Further, a magnetic disk 8 and a disk holder 9 connected to a bias mechanism #t12 are arranged in the reaction vessel 14, and a carbon target 1u and a disk holder 9 are connected to the sputtering tunnel W through an appropriate distance from the magnetic disk 8. A target holder 11 is arranged. In this device K, sputtered carbon particles react in plasma containing a hydrocarbon system, and a protective film is formed on the surface of the magnetic disk.

C2H2r C2H4 is used as raw material gas in such equipment.
+02H6,O[(4,C!, Hlo and other saturated or unsaturated hydrocarbons, C6H6, C6H, etc., which are liquid hydrocarbons gasified at room temperature and voltage, or these gases To form a protective film on the surface of a magnetic storage medium provided with a magnetic layer provided in an apparatus by supplying a mixed gas of a hydrocarbon-based gas and a gas other than hydrocarbons such as Ar, He, Ne, H2, etc. I can do it.

In the present invention, the protective film may be formed directly on the magnetic layer, but may be formed using Au, Pt, N, P, Or.

Ni, 5i02. Si, Ti, Ti-C, Eli3N
It can also be formed through a non-magnetic underlayer such as No. 4.

The operating conditions for the ionization plasma decomposition polymerization apparatus are the pressure in the reactor 'vo, o o i ~ I CI Tor.
r, and apply a direct or alternating voltage of 200 to 2000'V between the electrodes or 200 to 2UtllL.
It is preferable to apply an IV pressure of 100 KH2 to 29 MH2.

In addition, the operating conditions for bias sputtering equipment include gas pressure, sputtering power source, device voltage, and reaction time, etc., but these conditions vary depending on the shape of the equipment, size, etc., so it is difficult to specify or it is not normally used. This can be done under the conditions specified.

As explained above, the present invention provides a magnetic storage medium in which a cross-linked hydrocarbon group having a carbon/hydrogen ratio of 50,150 to 98/2 in molar ratio is formed in a magnetic 6 self-promoting medium. Accordingly, the present invention has the excellent effect that l111t abrasion resistance does not deteriorate even when exposed to high humidity conditions.

The present invention will be further described below with reference to Examples.

Example 1 A mirror-polished aluminum plate with a diameter of 9 cm and a thickness of 2 rruπ was plated with non-magnetic N1-P to a thickness of 50 μm, then polished to a thickness of 60 μm, and then 1
Co-nl-p (
ao: 80%.

(Ni: 15%, P: 5%) magnetic NAk 0.1
Electroless plating was performed to obtain μm rhinoceros. As a pretreatment for electroless plating, Nippon Kanigen Co., Ltd.'s 1 Schumer Sensitizer and Schumer Activator were used.

[Plating conditions] pH near: 5, liquid temperature: 75'C The plated disk was used as a sample as plated disk A.

Manufacture of magnetic storage media Using an ionized plasma separation device with the structure shown in Fig. 1, using each apple hydrocarbon gas as a raw material, a plated disk A with a thickness of 800X was coated under the conditions shown in Fig. 2. A hydrocarbon was formed.

For comparison, I would like to create a bath of paraffin with a melting point of 50 to 70''C in cyclohexane at a thickness of 80 degrees on a menki disc A (Experiment A67).

Table 2 (Note) Do... Direct current, AC... Alternating current Table 6 Also, assuming that the raw material gas, gas pressure, and applied voltage are the same as 0, the raw material gas, the gas pressure, and the applied voltage, the long ratio is 1 + jliJ The fourth step is to polish the rice to create a thick film, then divide the C and G elements.

Table 4 Example 2 Bias sputtering apparatus shown in Fig. 2 [(Closed) Tokuda P9I mag-tron type sputtering IJ7 apparatus (
The product name "0FS-8ESJ" is used, and as a target material, high purity carbon (Hitachi Chemical (closed) product name [
Using carbon HOB-18J) and sputtering under the conditions shown in Table 5, a carbonized ice cream protective film was formed on the plating disk A with a coating thickness of 800%. Formed thickly.

As a comparative example, sputtering was performed using Ar gas alone to obtain a carbon-based film of 800 years on plating disk A (Experiment 414).The formation conditions and evaluation results are shown below.
Shown in Table and Table 6.

Table 5 (Note) RF-・Radio Frequency Table 6 Also, experiments/168 to A14, atmospheric gas, gas pressure,
Table M7 shows the results of sputtering electrolytic corrosion and OH original analysis using the same conditions for the same bias voltage and longer reaction time to form a thicker film.

The physical properties shown in Tables 6 and 6 of Table 7 were measured as follows.

1) The dynamic friction coefficient measuring device used was a sliding property measuring device having the structure shown in Fig. 6, the head was a 2 mmφ sapphire ball, the head load was 5I,
The coefficient of dynamic friction was measured at a relative speed of 5III/sec.

2) Measuring the number of sliding movements Using the sliding property measuring device shown in Fig. 6, the head is 2mmφ.
Sapphire ball, head load 10J, relative speed 10W
The number of times of sliding was determined as the number of times until the protective film was destroyed under SeC conditions.

3) ASS (contact start stop) test head is YH-5350 type, head load 9.8
In the evening, rotation speed 3600 r, p, m, oN-oF
The number of cycles until a head crash occurred under the F30 second cycle condition was taken as the number of YO8S tests.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 shows ionized plasma decomposition,! ! FIG. 2 is an explanatory diagram of the bias sputtering device, and FIG. 6 is an explanatory diagram of the shield animal two-legged device. Number 1: Magnetic disk 2: Electrode 3: Electrode 4: Reaction vessel 5: Reaction vessel stand 6: Gas supply port A: Exhaust pipe 8 2 Magnetic disk 9: Disk holder 10: Carbon target 11: Target holder 12: Bias Power supply 13 Varnish buttering power supply 14: Reaction vessel 15: Gas supply port 16: Exhaust pipe 17: Magnetic disk 18: Holder 19: Sapphire bulb 20: Leaf spring 21: Strain cage 22: XY stage 23: Dinuk rotation motor 24: Frame patent applicant Denki Kagaku Kogyo Co., Ltd.

Claims (1)

[Claims] The molar ratio of carbon/hydrogen on the surface of a magnetic storage medium in which a gi magnetic metal compound is provided on a substrate is from 50,150 to 98/
A magnetic storage medium formed by forming a crosslinked hydrocarbon X-protected group having a range of 2.