JPH0366733B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a continuous magnetic medium that is widely used as a recording medium such as a floppy disk, a video recording tape, and an audio recording tape, and a method for manufacturing the same.

[Prior Art] In recent years, with the demand for high-density magnetic recording, research has been actively conducted on continuous magnetic media in which the magnetic layer is formed only of magnetic materials. Continuous magnetic media are manufactured by vacuum evaporation, sputtering, or plating. Since the magnetic layer of this continuous magnetic medium is a continuous thin film, dramatic improvements in recording density are expected not only in longitudinal magnetic recording but also in perpendicular recording systems. Further, development of applications to various product forms such as magnetic tapes and disk-shaped magnetic recording media is underway.

In particular, a long continuous thin film magnetic medium is conveyed in a meandering S-shape by conveyance guide rolls, passing between positioning rings and substrate holders provided in vertically symmetrical positions in a sputtering device. However, the magnetic layer is manufactured by depositing the magnetic layer on both sides of the substrate one side at a time through the ring from a target provided on the ring side.

[Problems to be Solved by the Invention] However, unlike coated magnetic media, the above-mentioned continuous magnetic media does not contain any binder, lubricant, etc. in the magnetic layer, so it has poor flexibility and lubricity and is not durable. I have a sexual problem.

For this purpose, a film 33 is formed on the continuous magnetic medium surface 32 by applying fluorine-based lubricant, silicone oil, higher fatty acids, and their derivatives singly or in combination as shown in FIG. Alternatively, as shown in FIG. 5, attempts have been made to form a continuous protective film 43 of amorphous carbon, a compound represented by SiO _x (x=1 to 2, etc.) on the surface of the continuous magnetic layer 42. However, none of them have achieved sufficient durability.

The present invention has been made in view of the above-mentioned drawbacks, and provides a continuous magnetic medium having sufficient durability by forming a protective layer made of a carbon fluoride thin film on the surface of a continuous magnetic layer on a heat-resistant base material, and manufacturing thereof. The purpose is to provide a method.

[Means for Solving the Problems] According to the present invention, a heat-resistant base material, a continuous magnetic layer formed only of a magnetic material on the heat-resistant base material,
The chemical formula (C _x F) _o formed on this continuous magnetic layer
(x is a number from 1 to 2, n is a natural number) A continuous magnetic medium is obtained, which is characterized by comprising a protective layer.

Furthermore, according to the present invention, a continuous magnetic layer made of only magnetic material is formed on a heat-resistant base material by a sputtering method,
Next, a carbon layer is formed on this continuous magnetic layer by a sputtering method, and then this carbon layer is heated in a mixed gas of nitrogen and fluorine at a temperature within the range of 200 to 600°C in order to fluorinate the carbon layer. , there is obtained a method for manufacturing a continuous magnetic medium characterized by forming a protective layer made of a carbon fluoride thin film.

[Effect] The operation of the present invention will be described.

When a high voltage is applied in a low-pressure argon atmosphere, argon plasma is generated by glow discharge or the like. Atoms ejected from the target by plasma collision collide with the surface of the base material, forming a thin film.

At this time, when the cathode target is Co/Cr,
A continuous magnetic layer consisting of a Co/Cr thin film having magnetic anisotropy perpendicular to the substrate plane is formed. Subsequently, a carbon thin film is formed on the continuous magnetic layer using carbon as the cathode target.

Next, this carbon thin film was placed in a nitrogen/fluorine mixture gas.
By heating at a temperature in the range of 200 to 600°C, the carbon thin film is fluorinated to form a protective layer of fluorocarbon. Note that the heating time is preferably about 2 hours.

The continuous magnetic medium thus obtained has extremely high durability because the continuous magnetic layer is covered with a fluorocarbon protective film.

Here, the magnetic material of the continuous magnetic layer is:
In addition to Co/Cr, a two-layer medium of Co/Cr and Ni/Fe or a continuous thin film of Ni/P/Co or the like can be used.

Further, as the heat-resistant base material, polyimide having a thickness of about 50 μm can be used, but the heat-resistant base material is not limited thereto.

Further, the sputtering method of forming the continuous magnetic layer and the carbon layer can be performed even in the same container.

[Example] An example of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view showing an example of a continuous magnetic medium according to the present invention. In this figure, a continuous magnetic layer 2 of a Co/Cr thin film is formed with a thickness of 0.2 μm over both surfaces of a heat-resistant substrate 1 made of a suitable film such as polyimide with a thickness of 50 μm.
Further, on this continuous magnetic layer 2, a protective layer 3 of a carbon fluoride thin film is formed.

Next, a method for manufacturing the above continuous magnetic medium will be explained step by step.

FIG. 2a is a schematic diagram showing an example of a method for forming a continuous magnetic thin film of a continuous magnetic medium according to the present invention. In this figure, a heat-resistant base material 1 is provided on a substrate holder 11. The target 10 made of Co/Cr magnetic material, the holder 11, and the heat-resistant base material 1 are placed in a vacuum container 12, and the vacuum container 12 is provided with an exhaust pipe connected to a vacuum pump 13 and an argon gas introduction pipe 14. There is. A continuous magnetic layer 2 made of a 0.2 μm thick Co/Cr thin film is formed on both sides of the heat-resistant substrate 1 by a sputtering method in a low-pressure argon gas atmosphere 15 inside the vacuum container 12 . That is, applying a high voltage between the holder 11 and the target 10,
Generates a glow discharge and generates argon plasma. This plasma starts from target 10,
The Co/Cr particles 10a are knocked out, and the Co/Cr particles 10a collide with the surface of the base material 1 and precipitate, forming a Co/Cr thin film 2 on the surface of the base material 1.

FIG. 2b is a schematic diagram showing an example of a method for forming a carbon thin film of a continuous magnetic medium according to the present invention.

In this figure, a continuous magnetic layer 2 of Co/Cr thin film is shown.
The heat-resistant base material 1 on which is formed is provided in a holder 17. Carbon target (abbreviated as C target) 16, the above base material 1 and holder 17
is inside the vacuum vessel 18. Here, vacuum container 1
8 is provided with an exhaust pipe connected to a vacuum pump 19 and an argon gas introduction pipe 14. Vacuum container 1
8 is made into a low pressure argon gas atmosphere 21, and a sputtering method is applied to the surface of the continuous magnetic layer 2 on the base material 1.
A carbon layer 4 made of a thin film with a thickness of 200A is formed.

FIG. 2c is a schematic diagram showing an example of a method for forming a fluorocarbon thin film of a continuous magnetic medium according to the present invention. The heat-resistant base material on which the Co/Cr thin film was formed as the continuous magnetic layer 2, and then the carbon layer 4 was formed, was heated in an electric furnace 22.
will be put into the The electric furnace 22 has a sealed structure and is provided with a heater 23 and a mixed gas introduction pipe 24 of fluorine and nitrogen. As a result, the inside of the electric furnace 22 is filled with a mixed gas 25 of nitrogen and fluorine.
Note that 26 and 27 are nitrogen and fluorine gas cylinders, respectively. By heating in the atmosphere of this mixed gas 25 at a temperature of 500°C for 2 hours, the carbon layer 4 on the heat-resistant base continuous magnetic layer 2 is fluorinated to form carbon fluoride represented by (C _x F) _o . A protective layer (3 in FIG. 1) is formed.

FIG. 3 shows the results of testing the durability of continuous magnetic media. In this figure, a curve 28 shows the relationship between the number of passes and the reproduction output of the continuous magnetic medium according to the embodiment of the present invention, and the reproduction output is shown as a relative value when the reproduction output when the number of passes is 0 is set to 1. . As is clear from this curve 28, the reproduction output of the continuous magnetic medium according to the example hardly decreases even after 2×10 ⁷ passes.

This durability test was conducted as follows. When installed in a commercially available double-sided floppy disk driver, the recording density is 10 [KFRPI] and the relative speed is 1.0 [m/s].
So I did a passware test.

For comparison, the test results of the conventional continuous magnetic media shown in FIGS. 4 and 5 are shown in curves 35 and 45 in FIG. 3, respectively.

In addition, in a continuous magnetic medium as shown in Fig. 4,
Continuous magnetic layer 32 of Co/Cr thin film on heat-resistant base material 31
is formed by sputtering method as in the example,
Furthermore, a fluorine-based lubricant (trade name, manufactured by Kreitx DuPont Co., Ltd.) is manufactured by spin coating on the continuous magnetic layer 32. In addition, in the continuous magnetic medium shown in FIG. 5, a continuous magnetic layer 42 of a thin Co/Cr film on a heat-resistant base material 41 is formed by the sputtering method as in the embodiment, and a layer 42 with a thickness of 200A is formed on the magnetic layer 42. of
A protective layer 43 made of a SiO ₂ film is formed.

[Effects of the Invention] As described above, according to the present invention, by forming a thin film of carbon fluoride on the surface of the continuous magnetic layer, a continuous magnetic layer having excellent adhesion to the continuous magnetic layer and sufficient durability can be obtained. A medium and a method for producing the same are obtained.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a continuous magnetic medium according to an embodiment of the present invention, FIG. 2a, FIG. 2b, and FIG. 2c
3 is a diagram showing the durability of the continuous magnetic medium according to the embodiment of the present invention, and FIG. 4 is a diagram showing the durability of the continuous magnetic medium according to the embodiment of the present invention. A sectional view showing an example of a continuous magnetic medium. FIG. 5 is a sectional view showing another example of a conventional continuous magnetic medium. In the figure, 1 is a heat-resistant base material, 2 is a continuous magnetic layer, 3 is a protective layer, 4 is a carbon layer, 10 is a Co/Cr target, 1
6 is C target, 11 and 17 are holders, 1
2 and 18 are vacuum containers, 22 is an electric furnace, 23 is a heater, 25 is a mixed gas of nitrogen and fluorine, 31 is a heat-resistant base material, 32 is a continuous magnetic layer, 33 is a film, 41 is a heat-resistant base material, and 42 is continuous The magnetic layer 43 is a continuous protective film.

Claims (1)

[Claims] 1. A heat-resistant base material, a continuous magnetic layer formed only of magnetic material on the heat-resistant base material, and a chemical formula (C _x F) _o (x is 1) formed on the continuous magnetic layer. A continuous magnetic medium comprising a protective layer represented by a number from 1 to 2, where n is a natural number. 2 The above magnetic materials include Co・Cr, Ni・Fe, Ni・
The continuous magnetic medium according to claim 1, characterized in that the continuous magnetic medium is made of at least one member selected from the group of P.Co. 3 Form a continuous magnetic layer made of only magnetic material on a heat-resistant base material by sputtering, then form a carbon layer on the continuous magnetic layer by sputtering, and then add nitrogen and fluorine to fluorinate the carbon layer. Heating at a temperature within the range of 200 to 600℃ in a mixed gas of
A method for manufacturing a continuous magnetic medium, comprising forming a protective layer made of a carbon fluoride thin film. 4 The above magnetic materials are Co・Cr, Ni・Fe, Ni・P・
4. The method for producing a continuous magnetic medium according to claim 3, wherein the continuous magnetic medium is made of at least one member selected from the group of Co.