JPH0954932A - Magnetic recording media - Google Patents

Abstract

(57) [PROBLEMS] To provide a metal thin film type magnetic recording medium having excellent electromagnetic conversion characteristics, excellent durability and corrosion resistance, and excellent running stability when using Fe as a material. It is to be. SOLUTION: The support and one or two or more layers of Fe- having Fe, N and O provided on one surface side of the support.
An N—O-based metal magnetic film, a diamond-like carbon film provided on the Fe—N—O-based metal magnetic film, and a fluorine-based lubricant film provided on the diamond-like carbon film; A magnetic recording medium comprising a metal thin film type back coat film provided on the other surface side of the support.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a magnetic recording medium having an Fe-based metal magnetic film.

[0002]

A metal thin film type magnetic recording medium in which a magnetic film is formed by dry plating means such as vapor deposition or sputtering is widely known. There are various materials for forming the magnetic film. For example, Co-Ni and Co-Cr magnetic alloys have been mainly used so far.

However, Co, Ni, Cr, etc. are expensive. In view of this problem, Fe is drawing attention. That is, Fe is low in price and rarely causes pollution problems. However, when Fe is used,
The examination of how the entire structure should be made is in the process of development, and it is a groping condition.

Therefore, an object of the present invention is to use a metal thin film type magnetic recording medium having excellent electromagnetic conversion characteristics, excellent durability and corrosion resistance, and excellent running stability when using Fe as a material. Is to provide.

[0005]

The object of the present invention is to provide a support and Fe, N and O provided on one side of the support.
A Fe-NO-based metal magnetic film having one or more layers, a diamond-like carbon film provided on the Fe-N-O-based metal magnetic film, and a diamond-like carbon film provided on the diamond-like carbon film. The magnetic recording medium is characterized by comprising a film of the above-mentioned fluorine-based lubricant and a metal thin film type back coat film provided on the other surface side of the support.

Particularly, a support and one or more layers of F having Fe, N and O provided on one surface side of the support.
an e-N-O-based metal magnetic film, a diamond-like carbon film provided on the Fe-N-O-based metal magnetic film,
A film of a fluorine-based lubricant provided on the diamond-like carbon film, a metal thin film type back coat film provided on the other surface side of the support, and a fluorine provided on the back coat film. And a film of a system-based lubricant.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention comprises a support and one or more Fe—N—O-based metal magnetic films having Fe, N and O provided on one surface of the support, Fe-N-
A diamond-like carbon film provided on the O-based metal magnetic film, a fluorine-based lubricant film provided on the diamond-like carbon film, and a metal thin film type provided on the other surface side of the support. And a back coat film.

In particular, a support and one or more layers of F having Fe, N and O provided on one surface side of the support.
an e-N-O-based metal magnetic film, a diamond-like carbon film provided on the Fe-N-O-based metal magnetic film,
A film of a fluorine-based lubricant provided on the diamond-like carbon film, a metal thin film type back coat film provided on the other surface side of the support, and a fluorine provided on the back coat film. And a film of a system lubricant.

As a support for the magnetic recording medium of the present invention,
It may be magnetic or non-magnetic. Typical examples include polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycyclohexylene dimethylene terephthalate, polyethylene bisphenoxycarboxylate, polyolefins such as polyethylene and polypropylene, cellulose acetate butyrate, cellulose acetate Examples thereof include cellulose derivatives such as pionate, vinyl-based resins such as polyvinyl chloride and polyvinylidene chloride, and non-magnetic plastic materials such as polyamide and polycarbonate. Of course, it is not limited to these. Also, various kinds of processing may be performed. For example, surface treatment is performed by corona discharge or other appropriate means. Further, polyester, polyurethane, oligomer or the like may be applied for improving the adhesiveness.

On one side of this support, PV such as oblique vapor deposition is used.
Fe-by the D (physical vapor deposition) method
One or two or more N—O type metal magnetic films are provided. This film formation will be described below by taking an evaporation method having a high film formation rate as an example. First, the inside of the oblique vapor deposition apparatus is evacuated to a predetermined vacuum degree, the Fe-based metal material is evaporated by an electron gun or other means, and the Fe-based metal particles are attached / deposited on the running support. At the time of this attachment / deposition, nitrogen gas (or nitrogen ions), oxygen gas (or oxygen ions), or the like is irradiated toward the Fe-based metal vaporized particles or the deposition surface to form 800 to 500 on the non-magnetic support.
The magnetic film having a thickness of 0Å is an Fe—N—O-based metal magnetic film. Fe: N: O is 50 to 85 at%: 10 to 40
at%: 5 to 40 at% is preferable. More preferably,
Fe: N: O 55-75 at%: 15-30 at%:
It is 10 to 30 at%. Since the content of metal elements other than Fe is small, for example, 5 wt% or less, the variation due to these metal elements is small.
It is specified only by N and O.

A protective film is provided on the surface of the magnetic film. As a material for forming this protective film, for example, Al, S
Although oxides, nitrides, carbides, boron nitrides, etc. of metals such as i, Ti, Cr, Zr, Nb, Mo, Ta, W, etc. are considered, diamond-like carbon was selected in the present invention. The diamond-like carbon protective film has a thickness of about 10 to 500Å. Particularly, about 30 to 200Å is preferable.

The protective film made of diamond-like carbon is formed by using, for example, CVD means. That is, the CVD device is operated on the support (metal magnetic film) running from the supply-side roll arranged in the vacuum tank to the winding-side roll through the cooling-can roll, and is attached to the cooling-can roll. When a hydrocarbon gas plasma is blown onto the formed metal magnetic film, a diamond-like carbon film is formed on the surface. As the hydrocarbon-based gas for forming the diamond-like carbon film, a paraffin-based hydrocarbon such as methane, an aromatic hydrocarbon such as benzene, or nitrogen containing N such as a homologue or derivative thereof as a ring constituent element is used. Examples of the contained cyclic hydrocarbons. In addition, H ₂ , O ₂ , N ₂ , NH ₃ , NO ₂ , NO
Etc. can also be used together with a hydrocarbon gas.

On the other surface (back surface) of the support, a back coat layer, particularly a metal thin film type back coat film (metal film) is provided. That is, for example, a wet-type plating means such as electroless plating, a vapor deposition method, a DC sputtering method, an AC sputtering method, a high-frequency sputtering method, a DC magnetron sputtering method, a high-frequency magnetron sputtering method, an ion beam sputtering method, etc. Is provided. The back coat film has a thickness of 1000 to 5000.
Å, more preferably about 1500 to 3500Å.
As the material of the metal particles forming the back coat film, for example, metals such as Al, Zn, Sn, Ni, Ag, Fe and Ti are used. Also, Cu-Al-X (where X is M
One or more selected from the group consisting of n, Fe and Ni) based alloys, Al-Si based alloys, Ti alloys and the like are used. Cu-Al-X (where X is Mn, Fe,
One or two or more selected from the group of Ni) -based alloy has a Cu content of 70 to 90 at%, an Al content of 8 to 25 at%, and a Mn content of 0.5 to 4 at%.
It is preferable that the Fe content is 0.4 to 5 at%, the Ni content is 0.4 to 4 at%, and the total content of Mn, Fe, and Ni is 1 to 6 at%. Also, Al-Si
The Al content in the system alloy is preferably 15 to 70 at%, and the Si content is preferably 15 to 70 at%.

Further, at the time of forming the back coat film, an oxidizing gas, oxygen ions or oxygen radical may be supplied to oxidize the surface layer portion of the metal film. Alternatively, a highly reactive nitrogen compound, nitrogen ion, or nitrogen radical may be supplied to nitride the surface layer portion of the metal-based film. Alternatively, a highly reactive carbon compound, carbon ion or carbon radical may be supplied to carbonize the surface layer portion of the metal-based film. It is preferable to supply a highly reactive carbon compound, carbon ion, or carbon radical to carbonize the surface layer portion of the metal-based film because it resembles the diamond-like carbon film.

The metal thin film type magnetic film or the metal thin film type back coat film may be formed by forming the magnetic film and then forming the back coat film. Conversely, the magnetic film may be formed after forming the back coat film. Alternatively, the films may be formed in almost the same process. Incidentally, in terms of process, since the diamond-like carbon film is provided on the magnetic film, it is preferable to form the magnetic film after forming the back coat film.

After the Fe--N--O type metal magnetic film, the diamond-like carbon film, and the metal thin film type back coat film are formed as described above, the fluorine type lubricant film is immersed or ultrasonically sprayed. 20-70Å by means such as
It is provided with a certain thickness. This fluorine-based lubricant is applied on the diamond-like carbon film. Alternatively, it is applied on the diamond-like carbon film and the metal thin film type back coat film. Of course, it is preferable to attach it on both sides. As the lubricant, for example, - (C (R) F- CF 2 -O) p - ( where group such as R is _{F, CF 3, CH 3)} , in particular HOOC-CF ₂
(OC ₂ F ₄ ) _p (OCF ₂ ) _q -OCF ₂ -COOH, F- (CF ₂ CF ₂ CF ₂ O) _n -CF
₂ CF ₂ COOH Carboxyl group-modified perfluoropolyether such as HOCH ₂ -CF ₂ (OC ₂ F ₄ ) _p (OCF ₂ ) _q -OC
F ₂ -CH ₂ OH, HO- (C ₂ H ₄ -O) _m -CH _2- (OC ₂ F ₄ ) _p (OCF ₂ ) _q-
OCH _2- (OCH ₂ CH ₂ ) _n -OH, F- (CF ₂ CF ₂ CF ₂ O) _n -CF ₂ CF ₂ CH ₂ OH
Alcohol-modified perfluoropolyethers such as those mentioned above, or saturated hydrocarbon groups such as alkyl groups, or unsaturated hydrocarbon groups, or aromatic hydrocarbon groups, or other functional groups on one or part of the molecule. The thing with a base etc. is mentioned. Specifically, Montecatini's FOMBL
INZ DIAC, FOMBLIN Z DOL, and Demnum SA manufactured by Daikin Industries, Ltd. are available.

[0017]

EXAMPLE 1 FIG. 1 shows a magnetic recording medium according to the present invention (8 m
It is a schematic diagram of a first embodiment of a magnetic tape for MVTR).
In FIG. 1, 1 is a PET film having a thickness of 7 μm. 2 is
1 provided on the surface of PET film 1 by oblique vapor deposition means
800Å thick Fe-N-O (Fe70at%: N15a
t%: O15 at%) based metal magnetic film.

A diamond-like carbon film 3 having a thickness of 75 Å is provided on the Fe-NO-based metal magnetic film 2. 4 is Cu-provided on the back surface of the PET film 1.
This is a 2000 Å thick metal-based film (back coat film) made of an Al-based alloy. In this metal thin film type magnetic recording medium, first, the PET film 1 is loaded into a vapor deposition apparatus, and a Cu—Al alloy filled in a crucible in the apparatus is irradiated with an electron beam to introduce oxygen gas. After vapor-depositing Cu-Al alloy particles on the back surface of the PET film 1, it is guided to an oblique vapor deposition apparatus and the Fe-based metal material filled in the crucible in the apparatus is irradiated with an electron beam to remove nitrogen ions and oxygen ions. Fe-based metal particles are deposited on the surface of the PET film 1 while irradiating with an ion gun. After that, the diamond-like carbon film 3 is provided on the Fe—N—O-based metal magnetic film 2 by guiding it to the ECR plasma CVD apparatus.

Numerals 5a and 5b are fluorine-based lubricants (FOMBL) having a thickness of 20Å, which are provided by ultrasonic spraying after the diamond-like carbon film 3 and the back coat film 4 are formed.
INZ DIAC) film.

[0020]

[Embodiment 2] In Embodiment 1, the Fe-N-O based metal magnetic film is formed of Fe-N-O (Fe75at%: N15at).
%: O10 at%) Example 1 except that a metal magnetic film was used.
It was carried out according to.

[0021]

Third Embodiment In the first embodiment, the Fe—N—O based metal magnetic film is formed of Fe—N—O (Fe80 at%: N10 at).
%: O10 at%) Example 1 except that a metal magnetic film was used.
It was carried out according to.

[0022]

Fourth Embodiment In the first embodiment, the Fe—N—O based metal magnetic film is formed of Fe—N—O (Fe65 at%: N30 at).
%: O5 at%) A metal magnetic film was used according to Example 1.

[0023]

[Comparative Example 1] Example 1 except that an Fe metal magnetic film was used instead of the Fe-N-O-based metal magnetic film.
It was carried out according to.

[0024]

[Comparative Example 2] In Example 1, when the Fe-based metal particles were vapor-deposited, nitrogen ions were not irradiated, and only oxygen gas was irradiated.
Instead of the e-N-O type metal magnetic film, Fe-O (Fe7
0 at%: O30 at%) A metal magnetic film was used in the same manner as in Example 1.

[0025]

COMPARATIVE EXAMPLE 3 The procedure of Example 1 was repeated except that a Si target was used instead of the diamond-like carbon film 3 and a SiO _x film was formed by DC magnetron sputtering while flowing an oxygen gas. .

[0026]

COMPARATIVE EXAMPLE 4 Example 1 was repeated except that myristic acid (lubricant) was used in place of the fluorine-based lubricant.

[0027]

COMPARATIVE EXAMPLE 5 In Example 1, carbon black having an average primary particle size of 20 nm and carbon black having an average primary particle size of 60 nm were mixed in a binder resin in a ratio of 1: 1 in place of the metal film 4 having a thickness of 2000Å. The procedure of Example 1 was repeated except that the added coating material was applied and dried to form a backcoat film having a thickness of 5000 liters.

[0028]

[Characteristics] The magnetic tapes obtained in the above examples were examined for running stability, durability and corrosion resistance. The results are shown in Table 1. Running stability is based on the jitter measurement value, durability is based on the still durability result, and corrosion resistance is 6
The rate of decrease in the saturation magnetic flux density Bs after standing for 1 week at 0 ° C. and 90% RH was used as a guide. The jitter was measured by using a commercially available Hi8mm VTR modified and a jitter meter was connected to it. Still durability was measured by using a spectrum analyzer to measure the decrease in luminance signal output at 7MHz when still reproduction was performed for 3 hours. It was measured.

Table-1 Jitter (ns) Still durability (dB) Corrosion resistance ΔBs (%) Example 1 47 -0.3 3 Example 2 45 -0.5 5 Example 3 49 -0.6 7 Implementation Example 4 48 -0.5 5 Comparative Example 1 73 -2.8 23 Comparative Example 2 61 -2.1 12 Comparative Example 3 51 -1.5 9 Comparative Example 4 64 -2.4 11 Comparative Example 5 58-0 .4 3 According to this, a Fe—N—O-based metal magnetic film, a diamond-like carbon film provided thereon, a fluorine-based lubricant film provided on the diamond-like carbon film, It can be seen that the magnetic recording medium which is combined with the metal thin film type back coat film is superior to the magnetic recording medium which is a comparative example in which any one of these constitutional requirements is lacking. That is, it is possible to understand how important the combination of the present invention is.

For example, as can be seen from the comparison between Example 1 and Comparative Examples 1 and 2, a diamond-like carbon film,
Even if the requirements for the fluorine-based lubricant film and the metal thin film type back coat film are satisfied, if the requirements for the Fe-NO-based metal magnetic film are lacking, the running property, durability, and corrosion resistance are poor. However, the features of the present invention cannot be achieved at all. Further, as can be seen from the comparison between Example 1 and Comparative Example 3, even if the requirements of the Fe—N—O based metal magnetic film, the fluorine based lubricant film, and the metal thin film type back coat film are satisfied, diamond-like If the requirements for the carbon film are lacked, the durability will be poor and the features of the present invention cannot be achieved at all.

Further, as can be seen from the comparison between Example 1 and Comparative Example 4, even if the requirements of the Fe—N—O based metal magnetic film, the diamond-like carbon film, and the metal thin film type back coat film are satisfied, Without the requirement for a system lubricant film,
The running property and durability are poor, and the features of the present invention cannot be achieved at all. Further, as can be seen from the comparison between Example 1 and Comparative Example 5, even if the requirements of the Fe—N—O based metal magnetic film, the diamond-like carbon film, and the film of the fluorine based lubricant are satisfied, the metal thin film type back If the requirements for the coat film are lacking, the running property is poor and the features of the present invention cannot be achieved at all.

[0032]

The magnetic recording medium suitable for high density recording can be obtained by using inexpensive Fe. Moreover, this magnetic recording medium is excellent in running property, durability and corrosion resistance.

[Brief description of drawings]

FIG. 1 is a schematic view of a magnetic recording medium according to the present invention.

[Explanation of symbols]

 1 Support 2 Metal Magnetic Film 3 Diamond-Like Carbon Film 4 Metal Film (Backcoat Film) 5a, 5b Fluorine Lubricant Film

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Junko Ishikawa 2606 Akabane, Kai-cho, Haga-gun, Tochigi Prefecture Kao Corporation Company Information Science Laboratory

Claims (2)

[Claims] 1. A support, one or two or more layers of Fe—N—O-based metal magnetic film having Fe, N and O provided on one surface side of the support, and the Fe—N—O system. A diamond-like carbon film provided on the metal magnetic film, a fluorine-based lubricant film provided on the diamond-like carbon film, and a metal thin film type backing film provided on the other surface side of the support. A magnetic recording medium comprising a coat film. 2. A support, one or more Fe—N—O-based metal magnetic film having Fe, N and O provided on one surface side of the support, and the Fe—N—O system. A diamond-like carbon film provided on the metal magnetic film, a fluorine-based lubricant film provided on the diamond-like carbon film, and a metal thin film type backing film provided on the other surface side of the support. A magnetic recording medium comprising a coat film and a film of a fluorine-based lubricant provided on the back coat film.