JPH07334830A - Recording medium and manufacturing method thereof - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a recording medium provided with a protective layer which has an excellent protective function and is capable of sufficiently exhibiting the function even if it is thin. A recording medium comprising a support, a recording layer, and a protective layer, wherein the protective layer is composed of diamond-like carbon containing an N component.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording medium such as a magnetic recording medium, and more particularly to a recording medium having a protective layer composed of diamond-like carbon containing N component.

[0002]

BACKGROUND OF THE INVENTION In a magnetic recording medium such as a magnetic tape, due to a demand for high density recording, a binder resin is not used as a magnetic film provided on a non-magnetic support instead of a coating type using a binder resin. It is well known that a metal thin film type that is not used has been proposed.

That is, there has been proposed a magnetic recording medium having a magnetic layer formed by a wet plating means such as electroless plating, or a dry plating means such as vacuum deposition, sputtering or ion plating. Since the magnetic recording medium of this type has a high packing density of magnetic material, it is suitable for high-density recording. By the way, since the metal magnetic film in this kind of metal thin film type magnetic recording medium is poor in durability due to sliding with the magnetic head, surface oxidation treatment is performed to provide a protective film by an oxide film. .

However, the surface oxidation means has little effect of improving the durability, and further studies have been conducted. From such a viewpoint, it has been proposed to provide a protective film of carbon, particularly diamond-like carbon, instead of the surface oxide film. For example, a C ₆ H ₆ gas as a carbon source is supplied to a plasma CVD apparatus, and the plasma gas from this is deposited on the surface of the metal magnetic film to form a magnetic recording medium having a protective film made of diamond-like carbon on the surface. Has been proposed (JP-A-6-41758).

However, this proposal is not enough. That is, in order to fully exhibit the intended function with this protective film made of diamond-like carbon, the thickness of the protective film needs to be about 100Å. By the way, it is preferable that the distance between the magnetic head and the magnetic film is small. This is because when the distance between the magnetic head and the magnetic film is d and the recording wavelength is λ, an output reduction (unit: dB) represented by −54.6 (d / λ) is brought about. Incidentally, it is said that, depending on a person, this output decrease is larger than that represented by the above equation and is as large as −100 (d / λ).

Therefore, considering that it is preferable that the distance (spacing loss) between the magnetic head and the magnetic film is small, a protective film which requires a thickness of 100 Å is never satisfactory.

[0007]

DISCLOSURE OF THE INVENTION It is an object of the present invention to provide a recording medium provided with a protective layer which has an excellent protective function and is capable of sufficiently exhibiting the function even if it is thin. The object of the present invention is a recording medium comprising a support, a recording layer and a protective layer, wherein the protective layer is composed of diamond-like carbon containing an N component. Accomplished by the medium.

A method of manufacturing a recording medium comprising a support, a recording layer, and a protective layer composed of diamond-like carbon containing an N component, wherein the protective layer is a C component and an N component. It is achieved by a method for producing a recording medium, characterized in that it is constituted by a CVD means using a compound having A method for producing a recording medium, comprising a support, a recording layer, and a protective layer composed of diamond-like carbon containing an N component,
The protective layer is achieved by a CVD method using a compound having a C component and a compound having an N component.

A method of manufacturing a recording medium comprising a support, a recording layer, and a protective layer composed of diamond-like carbon containing an N component, wherein the protective layer is a C component and an N component. CV using a compound having C, a compound having a C component, and / or a compound having an N component
This is achieved by a method for manufacturing a recording medium, which is characterized in that the recording medium is constituted by D means.

The N component of the diamond-like carbon protective layer in the present invention is 0.01 to 10%.
Is preferable. The diamond-like carbon film containing the N component according to the present invention is 2
The thickness is preferably 0 to 500Å. The lower limit of the thickness of the diamond-like carbon film containing the N component is more preferably 30Å, even more preferably 40Å, and even more preferably 50Å. The upper limit of the thickness of the diamond-like carbon film containing N component is 3
It is more preferably 00Å, even more preferably 200Å, further preferably 150Å, more preferably 100Å, most preferably 90Å.

The C component and N used in the above CVD (chemical vapor deposition) in the present invention.
As the compound having the component, a nitrogen-containing cyclic hydrocarbon can be preferably mentioned. In particular, a nitrogen-containing cyclic hydrocarbon containing N as a ring constituent can be mentioned as a preferable example. More preferably, the temperature is 25
A nitrogen-containing cyclic hydrocarbon containing N having a vapor pressure of 1 atm or more at 0 ° C. as a ring constituent element can be mentioned.
Preferred examples include compounds such as pyrazine, pyrazolidine, pyrazoline, pyrazole, pyridine, pyridazine, pyrimidine, piperidine, piperazine, imidazole, pyrrole, and their homologues and derivatives.

Further, only the nitrogen-containing cyclic hydrocarbon may be used, but cyclic hydrocarbons such as benzene and cyclohexane may be used together, or nitrogen compounds such as nitrogen and ammonia may be used together. Alternatively, both the cyclic hydrocarbon and the nitrogen compound may be used together. That is, nitrogen-containing cyclic hydrocarbons, cyclic hydrocarbons, such that the N component in diamond-like carbon is 0.01 to 10%,
The protective film may be formed by CVD using a nitrogen compound.

Further, when a compound having a C component and an N component such as a nitrogen-containing cyclic hydrocarbon is not used in CVD, that is, a compound having a C component and a compound having an N component are used, the C component is contained. Hydrocarbons are used as the compound. In particular cyclic hydrocarbons,
For example, benzene or homologues or derivatives thereof can be mentioned as preferable ones. Then, as the compound having the N component used together with the cyclic hydrocarbon such as benzene, for example, gases such as N ₂ , NH ₃ , NO ₂ and NO can be mentioned. Also in this case, the compound having the C component and the compound having the N component are mixed at a predetermined ratio so that the N component in the diamond-like carbon becomes 0.01 to 10%, and the protective film is formed by CVD. It should be formed.

The support of the magnetic recording medium used in the present invention is preferably non-magnetic, and the support is polyester such as PET, polyamide, polyimide, polysulfone, polycarbonate, olefin resin such as polypropylene, cellulose or the like. Polymer materials such as the above resins and vinyl chloride resins, and inorganic materials such as glass and ceramics are used.

A metal thin film type magnetic film is provided on the support by dry plating means such as vapor deposition means and sputtering means. Incidentally, a conventionally known vapor deposition device may be used. Examples of the material of the magnetic particles forming the metal magnetic film include metals such as Fe, Co, and Ni, as well as Co—Ni alloys, Co—Pt alloys, and Co—Ni—
Pt alloy, Fe-Co alloy, Fe-Ni alloy, Fe-C
o-Ni alloy, Fe-Co-B alloy, Co-Ni-Fe
A -B alloy, a Co-Cr alloy, or those containing a metal such as Al is used. In addition, an oxidizing gas or the like is provided at the time of forming the metal magnetic film, so that the magnetic characteristics are improved.

If necessary, a back coat layer is provided on the other surface side of the support. This back coat layer may be a metallic thin film formed by dry plating means such as vapor deposition means, or may be a coating type formed by applying a coating material containing carbon black or a binder resin. . A protective film is formed on the magnetic film. This protective film is composed of diamond-like carbon containing N component, and this type of protective film is formed as follows.

That is, as shown in FIG. 1, a magnetic recording medium 1 having a metal magnetic film provided on a support is wound from a supply side roll 3a arranged in a vacuum container 2 through a cooling can roller 4 to a winding side. Roll on roll 3b, and CVD device 5
Is operated to blow plasma of piperidine gas onto the metal magnetic film of the magnetic recording medium 1 attached to the cooling can roller 4, a diamond-like carbon film containing an N component is formed on the surface of the metal magnetic film. To be done. still,
In FIG. 1, 6 is a bias power supply.

When the diamond-like carbon film thus formed was examined by Auger electron spectroscopy or X-ray photoelectron spectroscopy, it was confirmed that this film contained N component. In addition, when a diamond-like carbon film formed by a CVD means was formed by using benzene instead of piperidine, this film did not have N. IIa
Type diamond-like carbon film, which was different from the diamond-like carbon film formed by using piperidine.

The present invention will be described below with reference to specific examples.

[0020]

【Example】

[Example 1] The thickness was 0.1 on a non-magnetic support surface such as a PET film having a thickness of 2 to 50 µm by oblique vapor deposition means.
A 5 μm Co—Ni (80% -20%) alloy magnetic film was provided.

A diamond-like carbon film 6 is formed on the alloy magnetic film by using the CVD means shown in FIG.
It was deposited to 0Å thickness. The gas introduced during this CVD was gasified by heating piperidine, and the gas introduction rate was 20 ml / min. The output of the microwave oscillator for generating plasma is 1 kW, the frequency is 2.45 GHz, the ECR magnetic field is 875 G, and the vacuum degree in the apparatus is 5 mTorr.

[Example 2] The same procedure as in Example 1 was carried out to form a diamond-like carbon film having a thickness of 50Å on the magnetic film. [Embodiment 3] The same operation as in Embodiment 1 is performed to obtain a thickness of 70Å
The diamond-like carbon film of No. 1 was provided on the magnetic film.

Example 4 In Example 1, piperidine (introduction rate: 20 ml / min) and N ₂ (carrier gas, introduction rate: 3 ml / min) were introduced to give a thickness of 40.
A diamond-like carbon film of Å was provided on the magnetic film. Example 5 In Example 1, piperidine (introduction rate is 20 ml / min) and N ₂ (carrier gas, introduction rate is 10 ml / min) are introduced, and a diamond-like carbon film having a thickness of 40 Å is placed on the magnetic film. Set up in.

Example 6 In Example 1, piperidine (introduction rate: 20 ml / min) and N ₂ (carrier gas, introduction rate: 100 ml / min) were introduced to form a diamond-like carbon film having a thickness of 40 Å. It was provided on the magnetic film. [Example 7] In Example 1, piperidine (introduction rate was 20 ml / min) and benzene (introduction rate was 5 ml / min).
min) and a diamond-like carbon film having a thickness of 50Å was provided on the magnetic film.

[Example 8] In Example 1, piperidine (introduction rate: 20 ml / min) and benzene (introduction rate: 20 ml / min) were introduced, and a diamond-like carbon film having a thickness of 50 Å was formed on the magnetic film. Provided. [Example 9] In Example 1, piperidine (introduction rate was 20 ml / min) and N ₂ (introduction rate was 3 ml / mi).
n) and benzene (the introduction speed was 100 ml / min) were introduced, and a diamond-like carbon film having a thickness of 50Å was provided on the magnetic film.

Example 10 In Example 1, piperidine (introduction rate was 20 ml / min), N ₂ (introduction rate was 3 ml / min), and cyclohexane (introduction rate was 20 ml / min).
and a diamond-like carbon film having a thickness of 50 Å was provided on the magnetic film. [Example 11] In Example 1, pyrazine (introduction rate: 18 ml / min) was introduced instead of piperidine,
A diamond-like carbon film having a thickness of 50Å was provided on the magnetic film.

Example 12 In Example 1, instead of piperidine, pyridine (introduction rate was 30 ml / mi
n) was introduced to form a diamond-like carbon film having a thickness of 70Å on the magnetic film. Example 13 In Example 1, instead of piperidine, benzene (introduction rate was 20 ml / min), N ₂ (introduction rate was 20 ml / min) and H ₂ (introduction rate was 200).
and a diamond-like carbon film having a thickness of 50 Å was provided on the magnetic film.

Example 14 In Example 1, benzene (introduction rate was 20 ml / mi) was used instead of piperidine.
n) and N ₂ (introduction rate is 100 ml / min) and H
₂ (the introduction speed is 200 ml / min), and a diamond-like carbon film having a thickness of 50Å was provided on the magnetic film.

Example 15 In Example 1, instead of piperidine, benzene (introduction rate was 20 ml / mi
n) and N ₂ (introduction rate is 200 ml / min) and H
₂ (the introduction speed is 200 ml / min), and a diamond-like carbon film having a thickness of 50Å was provided on the magnetic film.

Example 16 In Example 1, benzene (introduction rate was 20 ml / mi) was used instead of piperidine.
n) and N ₂ (introduction rate is 2000 ml / min) and H ₂
(The introduction speed is 200 ml / min) and the thickness is 6
A 0Å diamond-like carbon film was provided on the magnetic film.

Comparative Example 1 In Example 1, benzene (introduction rate: 20 ml / min) was used instead of piperidine.
And a diamond-like carbon film having a thickness of 60Å was provided on the magnetic film. Comparative Example 2 In Example 1, benzene (introduction rate was 20 ml / min) was introduced instead of piperidine, and a diamond-like carbon film having a thickness of 120 Å was provided on the magnetic film.

[Characteristics] A fluorine-based lubricant was applied on the diamond-like carbon film of the magnetic tape obtained in each of the above examples, and a 20 Å thick lubricating film was applied. And 8m
Slit to m width, load into 8mm VTR cassette,
It was mounted on a reproducing apparatus and the reproduction output at 7 MHz and the still durability (output decrease) were examined. The results are shown in Table-1.

Table-1 Reproduction output of N 7 MHz in protective film Still durability (dB) (atomic%) (dB) After 50 hours and after 100 hours Example 1 0.04 0.2 -1.4 -2. 5 Example 2 0.04 0.2-1.5 -2.4 Example 3 0.05 0.0 -1.3 -2.3 Example 4 0.12 0.4 -1.2 -1 .9 Example 5 0.14 0.5 -1.5 -2.8 Example 6 0.62 0.5 -1.7 -2.4 Example 7 0.03 0.3 -1.6- 2.6 Example 8 0.02 0.3 -1.3 -2.1 Example 9 0.01 0.3 -1.7 -2.3 Example 10 0.02 0.4 -1.6 -2.5 Example 11 0.04 0.5 -1.8 -2.6 Example 12 0.09 0.0 -1.4 -2.4 Example 13 0.10 0.4 -1. 3-2.5 Example 14 0.52 0.4 1.3-2.5 Example 15 1.03 0.3 -1.4 -2.6 Example 16 10.0 0.0 -1.5 -2.6 Comparative Example 1 0 0.0 -2 .8-5.7 Comparative Example 2 0-1.5-1.9-3.1 * N in the protective film is determined by Auger electron spectroscopy.

* Still durability is a decrease in output in still reproduction (7 MHz) after 50 and 100 hours. This shows that the diamond-like carbon film provided on the surface of the magnetic film contains N component. It turns out that it is rich in. In particular, even a thin film having a thickness of 40Å is highly durable, and the spacing loss can be reduced, so that the reproduction output becomes large.

[0035]

According to the present invention, a recording medium excellent in durability and reproduction output can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a diamond-like carbon film forming apparatus.

[Explanation of symbols]

 1 magnetic recording medium 2 vacuum container 5 CVD apparatus

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Shigemi Wakabayashi Inventor Shigemi Wakabayashi 2606 Akabane, Kaiga-cho, Haga-gun, Tochigi Kao Co., Ltd.Institute of Information Science (72) Inventor Akira Shiga 2606 Akabane, Kaiga-cho, Haga-gun, Tochigi Kao Company Information Science Laboratory

Claims (10)

[Claims] 1. A recording medium comprising a support, a recording layer, and a protective layer, wherein the protective layer is composed of diamond-like carbon containing an N component. 2. The recording medium according to claim 1, wherein the N content of the protective layer made of diamond-like carbon containing the N content is 0.01 to 10%. 3. A method for producing a recording medium comprising a support, a recording layer, and a protective layer made of diamond-like carbon containing an N component, wherein the protective layer is a C component and an N component. A method of manufacturing a recording medium, which comprises a CVD means using a compound having 4. A method for producing a recording medium comprising a support, a recording layer, and a protective layer made of diamond-like carbon containing an N component, wherein the protective layer is a compound having a C component. And a compound having an N component are used to form a recording medium. 5. A method for producing a recording medium comprising a support, a recording layer, and a protective layer made of diamond-like carbon containing an N component, wherein the protective layer is a C component and an N component. Using a compound having C, a compound having a C component, and / or a compound having an N component
A method of manufacturing a recording medium, characterized in that it is configured by means. 6. The method for producing a recording medium according to claim 3, wherein the compound having a C component and an N component is a nitrogen-containing cyclic hydrocarbon. 7. A compound having a C component and an N component is N
7. The method for manufacturing a recording medium according to claim 3, wherein the recording medium is selected from the group of nitrogen-containing cyclic hydrocarbons containing as a ring constituent element. 8. The method for producing a recording medium according to claim 4, wherein the compound having a C component is a hydrocarbon. 9. The method for producing a recording medium according to claim 4, wherein the compound having a C component is a cyclic hydrocarbon. 10. A compound having an N component is N ₂ , N
The method for producing a recording medium according to claim 4 or 5, wherein the recording medium is selected from the group consisting of H ₃ , NO ₂ , and NO.