JPH01267837A - Method and apparatus for producing magnetic recording medium - Google Patents

Abstract

PURPOSE:To stably assure and adequate amt. of a lubricating agent by introducing the vapor of a chain polymer having a functional group having a photosensitive characteristic at the terminal into a carbonaceous protective film, then subjecting the film to irradiation by UV light or far-UV light to bring the functional group having the photosensitive characteristic into reaction, thereby generating a chemical bond among the carbon atoms constituting the carbonaceous protective film. CONSTITUTION:A 1st layer having ferromagnetic is provided on the surface of a nonmagnetic substrate and the 2nd layer essentially consisting of amorphous carbon is provided on the 1st layer. The sample obt. in such a manner is held in the vapor of the compd. which is the chain polymer contg. the functional group having the photosensitive characteristic and is of 5-20C in the chain part. The sample is then irradiated by the UV light or far UV light to fix the compd. of 5-20C to the surface of the 2nd layer. The carbonaceous protective film and lubricating film are thereby formed, by which the lubricating agent is securely fixed to the surface of the carbonaceous protective film and, therefore, the lubricating performance is maintained stably over a long period of time.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to the manufacture of magnetic recording media such as magnetic disks, magnetic tapes, Freonbie disks, and magnetic cards, and particularly relates to the production of highly reliable head sliding devices. The present invention relates to a method and apparatus for manufacturing a magnetic recording medium that can manufacture a magnetic recording medium with high reproducibility.

[Conventional technology]

The capacity of magnetic disks, which are widely used as external storage devices for computers and the like, is increasing year by year, and there is an increasing demand for recording media with a high recording density per surface. Therefore, as a magnetic layer, Co-Ni
So-called sputter magnetic disks using thin films of metal alloys and the like are used, but when such metal thin films are used as recording layers, J
In order to avoid abrasion or damage to the recording layer or the head due to abrasion, it is necessary to coat the recording layer with a protective film and lubricant, and depending on the characteristics of the protective film and lubricant, the magnetic disk The reliability or lifespan of the product is greatly affected. Moreover, in order to improve the recording density, it is necessary to further narrow the flying spacing between the head and the disk, which increases the possibility of damage to the disk. Therefore, as a protective film and lubricant, A material with even better properties is required.

Regarding the above-mentioned retainers and lubricants, for example, see Journal of the Japanese Society of Applied Magnetics Vol. 1.10. NO, 1 (1986) 1st
As shown on page 0, as a mould-retaining film, hard <, J
A carbonaceous thin film is often used because it is difficult to damage, and a low molecular weight fluorine-containing bulky polymer compound is used as the lubricant.

[Invention or problem to be solved]

However, in the above conventional technology, the lubricant is
It merely adheres to the surface of the a1 film, and when the lubricant is consumed by finger movement with the head, the 1# friction coefficient between the head and the disk increases, eventually leading to destruction. Furthermore, if the amount of lubricant is increased to prevent this, there is a problem that when the head stops, the lubricant gathers around the slider and sticks to the head, causing malfunction.

Therefore, it is necessary to uniformly apply an appropriate amount of lubricant for agricultural maintenance, but since the wettability of the lubricant varies depending on the surface condition of the protective film, uneven coating may occur or There was also the problem that the amount fluctuated easily and the process lacked stability.0 The purpose of the invention was to overcome the problems of the prior art described above - to eliminate oil, reduce lubricant consumption, and provide appropriate lubrication. It is an object of the present invention to provide a method and apparatus for manufacturing a magnetic recording medium that can stably secure the amount of agent.

(Means for solving ajll) The above purpose is to place a disk-plate with a carbonaceous stock protection film formed on a magnetic thin film in a reaction tank, and in the tank, a disk plate having a photosensitive functional group at the end is placed in a reaction tank. After introducing the vapor of chain molecules゛□,
This can be achieved by irradiating the surface of the substrate with ultraviolet light or ultra-ultraviolet light to cause the photosensitive functional group to react and form a chemical bond with the carbon atoms constituting the carbonaceous bond. .

I will explain chain molecules that have photosensitive functional groups at their ends. First, the photosensitive functional groups described above are those that generate radicals or ions when irradiated with short wavelength light. For example, the following It's something like this.

Phenylazide group (>N.

Sulfonyl azide group -8Ot Ns carbonyl azide group -CONs Isocyanate group -NCO Cinnamoyl group +CH=C)1- CO-o()c)
l -CHi halogen group -CH2Cl, -
CM, Br, -CHtI The main chain of the chain molecule having the photosensitive functional group at its end is preferably linear and has about 5 to 20 carbon atoms. This is because when the number of carbon atoms is too small, the lubricity is poor, and when the number of carbon atoms is too large, it becomes difficult to evaporate. Also, if the main chain contains fluorine, it evaporates more easily (and has excellent lubricity).

Examples of counterfeits with main chains containing fluorine include per70roalkyl (-CF2-)n or perfluoropolyether (-CF, -0)n1%CFt-
CF2-0+n, (CF-CFz O→n (X is F or CHa), etc.

A brief explanation of the formation of the carbonaceous peritoneum is as follows.
The nucleus layer is formed by (a) using graphite as a target and sputtering it in an inert gas such as Ar, Xe, or Ne; (b) using a hydrocarbon gas or alcohol;
Organic compounds such as acetone alone or H2.

A method of mixing with Ar, He, Ne, etc. and forming by plasma CVD method, (c) ionizing a hydrocarbon gas or an organic compound such as alcohol, acetone, etc.
It can be created by an ion beam deposition method that accelerates it with a voltage of 1000 V and causes it to collide with a substrate to form a film.Which of these methods can be used? The plasma CVD method (b) is more preferable because it is likely to cause bonding with the terminal M functional group that destroys the photosensitivity in the lubricant due to a substitution reaction with hydrogen.

[Effect]

By forming the carbon film and lubricant layer through the process described above, the lubricant is firmly fixed on the surface of the carbonaceous protective film, ensuring stable lubrication performance over a long period of time. Furthermore, a phenomenon in which the lubricant aggregates around the head slider also occurs, and therefore the reliability and life of the magnetic disk can be dramatically improved.

Furthermore, by controlling the intensity of the irradiated light and the heat radiation time, the thickness of the lubricant layer can be adjusted and the in-plane distribution can be made uniform.

〔Example〕

Hereinafter, a method and apparatus for manufacturing a magnetic recording medium according to the present invention will be explained using examples.

Embodiment 1 FIG. 1 is a partially cross-sectional schematic diagram showing the structure of a magnetic recording medium manufacturing apparatus (@lubricant fixing device fl) according to the present invention, in which substrate supporting means 2. A reaction tank 1 consisting of raw material this, a quartz glass window 4, etc., and a low pressure mercury lamp 5. Heat source for heating raw material tank6. Piping 7
．． It is shown that it consists of a vacuum pump 8.

First, on an AA disk substrate with N1-P hard plating, a 0.5 μm thick Cr film, a 0.05 ttm thick UJCo-Nii alloy film, and a 0.05 μm carbon film were formed by sputtering. After the sequential formation, the substrate was placed in the reaction 4I11 of FIG. 1 and fixed by the substrate support means 2. Next, the inside of the reaction tank 1 is heated by the vacuum pump 8.
After evacuation until the pressure reaches orr or less, the raw material 'm5 containing perfluoropolyether whose end has been changed to phenylazide as a lubricant raw material is heated to 70° to 100°C by the heat source 6 for heating the raw material tank. The reactor 4111 is filled with vapor 9 of the raw material, and ultraviolet light M10 emitted from the low-pressure mercury lamp 5 is passed through the quartz glass window 4 to the substrate surface 11-
The top was irradiated for about 1 minute. The above process is shown in FIG.

A contact start/stop test (C8S test) was performed on the disk substrate obtained as described above. Using a test head of the same material and shape as the actual head, the disk was placed in contact with the disk surface. As a result of the test, the life of the disk was evaluated using a test in which the disk was rotated, the head was floated, and then the disk rotation was stopped again and the original state was returned to the original state at regular intervals. No damage was observed, and the results showed that the frictional force applied to the head during rotation increased by only about 20% compared to the initial value after 50 rotations. In addition, as a result of analyzing the six sides of the Dainuk substrate by 7-1 Lier transform infrared spectroscopy (FT-IR),
A peak corresponding to the absorption of the C-F bond was detected as N5. Since this peak does not disappear even when the disk substrate is heated to about 150° CG, it is considered that the above bond exists on the surface of the underlying carbon film.

For comparison, the above @ lubricant layer was not formed on the carbon film surface, and the above lubricant raw material was simply coated on the carbon film surface using a spin cord.
Similarly, as a result of conducting the C8S test, it was found that the surface of the carbon film developed scratches after IOK cycles or less, and the frictional force applied to the head increased by more than three times compared to the initial value. .

〔Effect of the invention〕

As described above, by manufacturing a magnetic recording medium using the manufacturing method and manufacturing apparatus of the present invention, the problems of the prior art can be solved and carbonaceous retention can be achieved! Manufacture a long-life, highly reliable magnetic recording medium that can form a lubricant layer on the film that is firmly bonded to the protective film, and that can ensure stability in head movement over a long period of time. 〇In the above explanation, we mainly talked about the example of magnetic tape, but magnetic tape, floppy disk
Other magnetic recording media such as tapes have similar problems regarding head sliding, and the same effects can be obtained by applying the present invention.

[Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional schematic diagram showing the structure of the magnetic recording medium manufacturing apparatus (@ lubricant fixing device) according to the present invention, and FIG. 2 is a process diagram showing the processing procedure of the magnetic recording medium manufacturing method of the present invention. 1... Reaction + Il! 2... Substrate support means 3... Raw material 4... Quartz glass window 5.
...Low pressure mercury lamp 6...Heat source for heating raw material tank 7...
・Piping 8...Vacuum bomb 9...Raw material vapor 1o...Ultraviolet light 11...Substrate surface

Claims (1)

[Claims] 1. A method for manufacturing a magnetic recording medium, characterized by comprising the following steps. i Step of providing a first layer having ferromagnetism on the surface of the non-magnetic substrate ii Step of providing a second layer mainly made of amorphous carbon on the first layer iii Step of exposing the sample obtained in step ii A chain molecule with a functional group at the end, and the number of carbon atoms in the chain part is 5 to 5.
Step 2 of fixing the compound on the surface of the second layer by holding the compound in the vapor of No. 20 and irradiating it with ultraviolet light or deep ultraviolet light, the photosensitive functional group is a phenyl azide group, 2. The method for producing a magnetic recording medium according to claim 1, wherein the group is any one of a sulfonyl azide group, a carbonyl azide group, a glycidyl group, an isocyanate group, a cinnamoyl group, and a halogen group. 3. The chain molecule with the photosensitive functional group at the end has the structure of the chain part (-CF_2-)m, (-C
F_2-O-)n, ▲There are mathematical formulas, chemical formulas, tables, etc.▼
3. The method for manufacturing a magnetic recording medium according to claim 1, wherein X is a chain molecule represented by either F or CF_3, m≦20, n≦10. 4. Claims 1 to 3, wherein the second layer mainly consisting of amorphous carbon is a layer deposited by decomposing a hydrocarbon compound or an oxygen-containing hydrocarbon compound by a plasma CVD method. A method of manufacturing the magnetic recording medium described above. 5. An apparatus for manufacturing a magnetic recording medium, characterized in that the main components are a reaction tank body consisting of a substrate support device, a raw material tank, a quartz glass window, a vacuum pump, a low-pressure mercury lamp, and a heat source for heating the raw material tank.