JPH10275323A - Magnetic recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance a slit characteristic at the time of production and to lower an error rate by disposing thin-film layers between a nonmagnetic base and a magnetic layer and between the magnetic layer of the nonmagnetic base and the surface on the opposite side thereof, respectively. SOLUTION: This magnetic recording medium 1 includes the nonmagnetic base 2, the magnetic layer 3 disposed on one surface side of this base 2 and a back-coating layer 4 disposed on the other surface side of the base 2. The first thin-film layer 5 is disposed between the base 2 and the magnetic layer 3 and the second thin-film layer 6 is disposed between the base 2 and the backcoating layer 4. These thin-film layers are formed of materials different from each other. The rigidity of the magnetic recording medium itself may be optimized by providing the medium with the first protective layer 5 and the second protective layer 6. In addition, the slit characteristic is improved, by which the spilling down of magnetic material powder, etc., from the end faces of the slits is prevented and the error rate of the magnetic recording medium is drastically lowered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording medium, and more particularly, to a magnetic recording medium having a high slit property at the time of manufacture and a reduced error rate.

[0002]

2. Description of the Related Art A magnetic recording medium such as a magnetic tape generally has a structure in which a magnetic layer containing a magnetic powder and a binder is formed on a support by coating. When such a type of magnetic tape is accommodated in a tape cartridge of a predetermined standard and used, in order to increase the recording capacity,
The thickness of the magnetic tape, especially the thickness of the support, must be reduced.

However, when the thickness of the support is reduced, the rigidity of the magnetic tape is reduced, so that the slitting process at the time of manufacturing the magnetic tape becomes unstable, the slit width varies, and various powders contained in the magnetic tape are produced. Spills off from the slit end face, which causes an increase in the error rate. There is also a disadvantage that high-speed slitting becomes difficult.

On the other hand, as a technique for forming a thin film on a support for the purpose of improving magnetic properties, for example, Japanese Patent Application Laid-Open No.
0-114206 and JP-A-6-103557
And the like are known. However, according to the technology described in the above publication, only one metal thin film layer is formed on the support, so that the rigidity of the magnetic recording medium is not sufficient, and it is still unsatisfactory to stabilize the slitting process. Did not. In addition, the technique described in the above publication aims to improve the conductivity of the magnetic recording medium and prevent the transfer of the back coat layer to the magnetic layer, and there is no mention of stabilizing the slitting process. Absent.

Accordingly, it is an object of the present invention to provide a magnetic recording medium having a high slit property at the time of manufacture and a reduced error rate.

[0006]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that the above object can be achieved by a magnetic recording medium provided with a specific layer at specific positions on both surfaces of a support.

The present invention has been made based on the above findings.
In a magnetic recording medium comprising a non-magnetic support and a magnetic layer provided on the non-magnetic support and containing a magnetic powder and a binder, the magnetic recording medium includes a non-magnetic support between the non-magnetic support and the magnetic layer. The above object has been attained by providing a magnetic recording medium characterized in that a thin film layer made of a different material is provided on each surface of the non-magnetic support opposite to the magnetic layer.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the magnetic recording medium of the present invention will be described below with reference to the drawings. here,
FIG. 1 is a schematic diagram showing the structure of the first embodiment of the magnetic recording medium of the present invention.

A magnetic recording medium 1 shown in FIG. 1 includes a non-magnetic support 2, a magnetic layer 3 provided on one surface of the support 2,
And a back coat layer 4 provided on the other surface side of the support 2. A first thin film layer 5 is provided between the support 2 and the magnetic layer 3, and a second thin film layer 6 is provided between the support 2 and the back coat layer 4. Is provided. Hereinafter, details of the support and each layer will be described.

The non-magnetic material constituting the support 2 includes polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycyclohexylene dimethylene terephthalate and polyethylene bisphenoxycarboxylate, and polyolefins such as polyethylene and polypropylene. And cellulose derivatives such as cellulose acetate butyrate and cellulose acetate propionate; vinyl resins such as polyvinyl chloride and polyvinylidene chloride; and plastic materials such as polyamide and polycarbonate. The support composed of these materials may be subjected to a uniaxial or biaxial stretching treatment, a corona discharge treatment, or the like, as necessary.

In particular, from the viewpoint of obtaining a thin and highly durable magnetic recording medium, 350 to 100
It is preferable to use a polyester film having a Young's modulus of 0 kg / mm ² and a thickness of 1.0 to 5.8 μm. That is, if the Young's modulus is less than 350 kg / mm ^2, it may be difficult to improve the durability and the like of the magnetic recording medium. It is not realistic because it is necessary to increase the thickness, and if it exceeds 1000 kg / mm ² , the rigidity and strength become too high, which may be unfavorable. If the thickness is less than 1.0 μm, the ratio of the thickness of the support 2 to the thickness of the thin film layers 5 and 6 becomes too large, and the rigidity of the support 2 is less than the rigidity of the support 2. When the rigidity is high, the magnetic recording medium may be rather hard. When the thickness exceeds 5.8 μm, the ratio of the thickness of the support 2 to the thickness of the thin film layers 5 and 6 is too small, and Since the effect of providing 5 and 6 may be reduced, it is preferable to be within the above range. When using a support made of the polyester film, its Young's modulus is 500 to 1000 kg /.
mm ² , more preferably 600 to 950 kg
/ Mm ² is more preferable. Also, the thickness is 2
More preferably, it is 5.5 μm, and 2.5 to 5.3.
More preferably, it is μm. Further, on the polyester film, it is necessary to have a smooth surface because a magnetic layer adapted for high-density recording is applied, and
Since it is necessary to have appropriate running properties, it is necessary to have appropriate unevenness. Therefore, the lower limit of the center line surface roughness Ra of the polyester film is preferably 0.001.
5 μm, more preferably 0.002 μm, most preferably 0.003 μm, and the upper limit is preferably 0.02 μm.
It is 5 μm, more preferably 0.020 μm, and most preferably 0.018 μm. The lower limit of the ten-point average roughness Rz of the polyester film is preferably 0.0%.
20 μm, more preferably 0.025 μm, and most preferably 0.030 μm, and the upper limit is preferably 0.1
It is 2 μm, more preferably 0.10 μm, and most preferably 0.09 μm. PET as the above polyester
(Polyethylene terephthalate), PEN (polyethylene naphthalate) and the like are preferably used.

The magnetic layer 3 contains a magnetic substance powder and a binder as described above. As the magnetic powder,
What is usually used for magnetic recording media, for example, metal oxide magnetic powder, metal magnetic powder, hexagonal ferrite magnetic powder and the like can be used without any particular limitation. Similarly, as the binder, those commonly used for magnetic recording media, for example, thermoplastic resins, thermosetting resins, reactive resins, and mixtures thereof can be used without any particular limitation.

The magnetic layer 3 is formed by applying a magnetic paint obtained by dispersing and dissolving the magnetic powder, the binder, and various additives used as necessary in a solvent. As the solvent, a ketone solvent, an ester solvent, an ether solvent, an aromatic hydrocarbon solvent, a chlorinated hydrocarbon solvent, or the like can be appropriately selected and used. Also, various solvents described in JP-A-57-162128 can be used. As the additive, an antistatic agent, a lubricant, an abrasive, and the like can be appropriately selected and used. Further, various additives described in JP-A-57-162128 can also be used.

The thickness of the magnetic layer 3 is preferably smaller than the thickness of the support 2. Further, from the viewpoints of high C / N and high output, it is necessary to make the magnetic layer 3 multilayer, or to make the upper layer of the magnetic layer particularly thin as in the third embodiment described later. Is preferred. In particular, from the viewpoint of improving output and durability, the thickness of the magnetic layer 3 is 0.1 to 2.5 μm.
And more preferably 0.15 to 2.0 μm. The magnetic layer 3 and the first thin film layer 5
An undercoat layer (including a binder, a filler, and the like) for the magnetic layer 3 may be provided between the first and second magnetic layers.

The back coat layer 4 is an optional layer, and is usually formed by applying a known back coat paint. The components contained in the backcoat paint include a binder, an antistatic agent, a lubricant, an abrasive, and the like. As these components, the same components as those contained in the magnetic paint are used.

Thus, in the magnetic recording medium 1 shown in FIG. 1, the first thin film layer 5 is provided between the support 2 and the magnetic layer 3 as described above. A second thin film layer 6 is provided between the second coating layer 2 and the back coat layer 4. These two thin film layers are formed from different materials.

By providing the first thin film layer 5 and the second thin film layer 6, the rigidity of the magnetic recording medium itself can be optimized, and the displacement of the elongation in the width direction of the magnetic recording medium (particularly, magnetic tape) can be improved. Can be suppressed. As a result, width fluctuation at the time of slitting is reduced, and the slitting process is stabilized. In particular, as is clear from the examples described below,
High speed slitting is also possible. In addition, by improving the slitting property, the slit end face becomes smooth, and various powders such as magnetic powder contained in the magnetic recording medium are prevented from spilling from the slit end face, and an error of the magnetic recording medium is prevented. The rate is greatly reduced.

The material for forming the first thin film layer 5 and the second thin film layer 6 can optimize the rigidity of the magnetic recording medium and is not particularly limited as long as they are different from each other. In particular, the first thin film layer 5 is formed of a metal or a semi-metal or an alloy thereof, and the second thin film layer 6 is formed of a metal or a semi-metal from the viewpoint of optimizing film forming properties, rigidity, strength and hardness. It is preferably formed from a metal oxide, nitride, carbide, silicide, or a composite thereof. By using such a material as the material for forming the first thin film layer 5 and the second thin film layer 6, the rigidity can be properly balanced.

Metals Fe, N forming the first thin film layer 5
i, Co, Ti, W, Mo, Al, Mn, Cr, Cu,
At least one selected from the group consisting of Zn, Zr and Sn is preferably used, and the metalloid is B, Si,
At least one selected from the group consisting of Ge and Sb is preferably used, but is not limited thereto. The first thin film layer 5 is made of Fe, Ni, Co, T
i, W, Mo, Al, Mn, Cr, Cu, Zn, Zr,
It may be formed from an alloy selected from the group consisting of Sn, B, Si, Ge and Sb. Of these materials,
Particularly preferably used are Co, Cu, Al, Ti
And a metal such as Ni, a metal such as Si and Ge or an alloy thereof, and particularly preferably used are a metal such as Co, Ti, Ni and Cu,
It is a simple substance of a semimetal such as i and Ge or an alloy thereof.
On the other hand, the metal, metalloid oxide, nitride, carbide, silicide, or a composite thereof that forms the second thin film layer 6 is formed from the metal or metalloid used to form the first thin film layer 5. Is preferably performed. By forming the second thin film layer 6 from such a material, there is an advantage that the second thin film layer 6 can be made into ceramics to further optimize the rigidity of the magnetic recording medium.

The first thin film layer 5 may be formed of a magnetic metal or an alloy thereof, or may be formed of a non-magnetic metal or metalloid or an alloy thereof. The second thin film layer 6 may be formed of a metal oxide having magnetism, or may be formed of a metal or metalloid oxide, nitride, carbide, or silicide having no magnetism. May be.

The first thin film layer 5 and the second thin film layer 6
Are formed by known thin film forming means. Examples of such a thin film forming means include a vacuum plating method (dry plating method) such as a wet plating method, vacuum deposition, sputtering, and ion plating, and it is particularly preferable to use a vacuum film forming method from the viewpoint of corrosion resistance.

The thicknesses of the first thin film layer 5 and the second thin film layer 6 are not particularly limited, and are appropriately selected depending on the material and thickness of the support to be used.
It is preferably 1 μm, more preferably 0.08 to 0.3 μm. In this case, the thicknesses of the two may be the same or different, but the ratio of the thicknesses of the two (first thin film layer 5 / second thin film layer 6) is 0.6 to 1.2.
Is preferable, and more preferably 0.7 to 1.1.

The total thickness of the first thin film layer 5 and the second thin film layer 6 is preferably 0.05 to 1 μm, more preferably 0.08 to 0.6 μm, and 0.1 to 0.6 μm. More preferably, it is 1 to 0.4 μm. If the total thickness is less than 0.05 μm,
6 may not be sufficiently effective, and if it exceeds 1 μm, depending on the material used, the rigidity of the magnetic recording medium generally becomes too strong, resulting in poor contact with the head and a decrease in output. In some cases, problems such as dripping and uneven wear of the head may occur.

In the magnetic recording medium 1 of the present embodiment having the above configuration, the overall thickness is 2.5 to 8.0 μm.
m, more preferably 3.0 to 7.0 μm.

Next, the second and third embodiments of the magnetic recording medium of the present invention will be described with reference to FIGS. Here, FIGS. 2 and 3 are schematic diagrams (corresponding to FIG. 1 respectively) showing the structures of the magnetic recording medium according to the second and third embodiments of the present invention. In the second and third embodiments, only the points different from the first embodiment will be described, and for the points not particularly described, the detailed description of the first embodiment will be applied as appropriate. You. 2 and 3, the same members as those in FIG. 1 are denoted by the same reference numerals.

In the magnetic recording medium 1 of the embodiment shown in FIG. 2, carbon is mainly applied to the surface (outer surface) of at least one of the first and second thin film layers 5 and 6 (both in FIG. 2). A thin film as a component (hereinafter simply referred to as a “carbon thin film”) is provided continuously. That is, the first carbon thin film 7 is provided between the first thin film layer 5 and the magnetic layer 3.
Is provided, and a second carbon thin film 8 is provided between the second thin film layer 6 and the back coat layer 4.
By providing such a carbon film, there is an advantage that the film adhesion between the layers is improved, the durability of the magnetic recording medium is improved, and the recording / reproducing characteristics are improved.

The first carbon thin film 7 and the second carbon thin film 8 are each formed of a carbonaceous material, for example, diamond-like carbon (DLC), glassy carbon, graphite-like carbon (GLC), or the like. In this case, the material for forming the first carbon thin film 7 and the second carbon thin film 8 may be the same or different, but in particular, in order to realize good head contact and obtain high output. Preferably, both layers are formed from DLC.

The first carbon thin film 7 and the second carbon thin film 8 are formed by various types of PVD (physical vapor deposition) such as vapor deposition, DC sputtering, AC sputtering, high-frequency magnetron sputtering, and ion beam sputtering. And / or CVD (chemical vapor deposition) means.

The thickness of the first carbon thin film 7 and the thickness of the second carbon thin film 8 may be the same or different, and are preferably each 0.00 to obtain a suitable rigidity.
6-1 μm, more preferably 0.08-0.6 μm
m. The sum of the thicknesses of the two is 0.08 to 0.2 to achieve high output by achieving good head contact.
It is preferably 8 μm, more preferably 0.1 to 0.4 μm.

In the magnetic recording medium 1 of the embodiment shown in FIG. 3, a nonmagnetic or magnetic coating layer 9 is provided between the first thin film layer 5 and the magnetic layer 3. By providing such a coating layer 9, there is an advantage that the bonding between the layers is improved and the durability of the magnetic recording medium is improved.

When the coating layer 9 is non-magnetic, the coating layer 9
Is composed mainly of non-magnetic powder, in addition to this, a binder,
It is formed by applying a non-magnetic paint in which an antistatic agent, a lubricant, an abrasive and the like are dispersed and dissolved in a solvent.
On the other hand, when the coating layer 9 is magnetic, the coating layer 9 is mainly composed of a magnetic powder such as a hard magnetic powder or a soft magnetic powder, and in addition, a binder, an antistatic agent, a lubricant and It is formed by applying a magnetic paint in which an abrasive or the like is dispersed and dissolved in a solvent.

When the coating layer 9 is provided, it is preferable that the coating layer 9 is formed together with the magnetic layer 3 by a simultaneous multi-layer coating method using a wet-on-wet method, so that the boundary between them is smooth. In addition, it is preferable because the surface property of the magnetic layer 3 is improved.

The thickness of the coating layer 9 is preferably 0.05 to 2 μm from the viewpoints of flexural rigidity of the magnetic recording medium, prevention of occurrence of cupping and curling, and 0.1 to 0.1 μm.
More preferably, it is 5 μm.

Although the magnetic recording medium of the present invention has been described based on the preferred embodiments, the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention. For example, in addition to the above embodiment, the magnetic recording medium of the present invention has a configuration as shown in FIG. 4, that is, a non-magnetic support 2, a magnetic layer 3 provided on one surface side of the support 2, A back coat layer 4 provided on the other surface side of the support 2; a first thin film layer 5 is provided between the support 2 and the magnetic layer 3; A second thin film layer 6 is provided between the back coat layer 4 and a first carbon thin film 7 between the first thin film layer 5 and the magnetic layer 3. A second carbon thin film is provided between the second thin film layer and the back coat layer; and a non-magnetic or magnetic coating layer is provided between the first thin film layer and the magnetic layer. 9 may be provided. Further, a primer layer may be provided between the support 2 and the first thin film layer 5 or the second thin film layer 6, or a hard system using a long wavelength signal between any layers in a magnetic recording medium. Correspondingly, another magnetic layer and another layer for recording a servo signal or the like may be provided.
Further, in the magnetic recording medium shown in FIGS. 1 to 4, the back coat layer may not be formed. Further, in the magnetic recording medium shown in FIGS. 2 and 4, both the first carbon thin film and the second carbon thin film are formed, but one of these layers may not be formed. In addition, the magnetic recording medium of the present invention uses an 8 mm video tape or D
Although it is suitable as a magnetic tape such as an AT tape, a DLT tape, and a DVC tape, it is particularly suitable as a magnetic tape having a small total thickness among them.

[0035]

The following examples illustrate the effectiveness of the present invention. However, the scope of the present invention is not limited to such an embodiment.

Example 1 PET film having a thickness of 4.5 μm (support: Ra = 0.006 μm, Rz = 0.04)
A first thin film layer (0.15 μm thick) made of Co is formed on one surface of the
On the other surface of the film, a second thin film layer (0.15 μm in thickness) made of Co—O was formed by vacuum evaporation. Next, a first carbon thin film (thickness 0.03 μm) and a second carbon thin film (thickness 0.03 μm) made of DLC were formed on the first thin film layer and the second thin film layer by microwave plasma CVD. . A magnetic paint having the following composition is applied on the first carbon thin film to a thickness of 0.8
A magnetic layer having a thickness of 90 μm and 300 kg /
After performing a calendering treatment under the condition of cm, a back coat having the following composition was applied on the second carbon thin film to form a back coat layer having a thickness of 0.5 μm. After this,
After aging at 50 ° C for 12 hours, speed 300m
The sample was slit into 3.81 mm width at / min and loaded into a DDS-2 cassette.

<Mixing of magnetic paint> 100 parts by weight of acicular metal magnetic powder mainly composed of iron (major axis length: 0.065 μm, axial ratio: 5, Hc: 1980 Oe, saturation magnetization: 143 emu / g) 7 parts by weight of alumina (abrasive, average particle diameter: 0.18 μm) 2 parts by weight of carbon black (antistatic agent) (average primary particle diameter: 0.02 μm) 10 parts by weight of vinyl chloride copolymer (binder) Parts: 7 parts by weight of polyurethane resin (binder) 1.5 parts by weight of stearic acid (lubricant) 3 parts by weight of 2-ethylhexyl oleate (lubricant) 4 parts by weight of isocyanate curing agent 120 parts by weight of methyl ethyl ketone 80 parts by weight ・ cyclohexanone 40 parts by weight

<Blending of backcoat paint>-40 parts by weight of carbon black (antistatic agent) (average primary particle diameter: 0.018 µm)-50 parts by weight of Nipporan 2301 (binder) [trade name: Nippon Polyurethane Industry Co., Ltd.] Polyurethane] 4 parts by weight of polyisocyanate (curing agent) [trade name (D-250N) manufactured by Takeda Pharmaceutical Co., Ltd.] 20 parts by weight of nitrocellulose 1 part by weight of stearic acid 140 parts by weight of methyl ethyl ketone Toluene 140 Parts by weight ・ 140 parts by weight of cyclohexanone

Example 2 PET film having a thickness of 5.5 μm (support: Ra = 0.005 μm, Rz = 0.04)
8 μm) on one surface by Ni-Fe (80-
20 at%) and a second thin film layer (thickness 0.15 μm) made of SiO _{x on} the other surface of the PET film by vacuum evaporation.
m) was formed. Next, a second carbon thin film (0.04 μm in thickness) made of DLC was formed on the second thin film layer by microwave plasma CVD. Subsequent operations were performed in the same manner as in Example 1 except that the slit speed was set to 400 m / min to obtain a magnetic tape.

Example 3 PET film having a thickness of 4.5 μm (support: Ra = 0.006 μm, Rz = 0.04)
5 μm), a first thin film layer (thickness 0.3 μm) made of Al—O is formed on one surface of the PE by vacuum evaporation, and the PE
A second layer made of Cu by vacuum evaporation on the other surface of the T film.
A thin film layer (thickness 0.15 μm) was formed. Subsequent operations were performed in the same manner as in Example 1 to obtain a magnetic tape.

Comparative Example 1 A PET film having a thickness of 4.5 μm without a first carbon thin film, a first thin film layer, a second carbon thin film and a second thin film layer (support; Ra = 0.00)
A magnetic tape was obtained in the same manner as in Example 1 except that 6 μm, Rz = 0.045 μm) was used as it was.

[Evaluation of Performance] In order to evaluate the performance of the magnetic tapes obtained in Examples and Comparative Examples, 1) fluctuation of the slit width, 2) powder falling off from the slit end face,
3) The state of the slit end face and 4) the error rate were measured by the following methods. Table 1 shows the results.

<Deviation of Slit Width> The tape width was measured with an optical microscope.

<Spilled powder from slit end face and state of slit end face> Observed by a scanning electron microscope (SEM).

<Error rate> Measured using a DDS-2 drive.

[0046]

[Table 1]

As is evident from the results shown in Table 1, the magnetic tape obtained in the example had better slits and a lower error rate than the magnetic tape obtained in the comparative example. You can see that there is.

[0048]

As described above, according to the present invention,
By using the above-described thin film layer, the rigidity of the magnetic recording medium itself is optimized, and the displacement of the magnetic recording medium (particularly, magnetic tape) in elongation in the width direction can be suppressed. As a result, width fluctuation at the time of slitting is reduced, and the slitting process is stabilized. Also, a high-speed slit is possible.
In addition, by improving the slitting property, various powders can be prevented from falling off from the slit end face, and a magnetic recording medium having a significantly reduced error rate can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a structure of a first embodiment of a magnetic recording medium of the present invention.

FIG. 2 is a schematic diagram (corresponding to FIG. 1) showing the structure of a magnetic recording medium according to a second embodiment of the present invention.

FIG. 3 is a schematic diagram (corresponding to FIG. 1) showing the structure of a third embodiment of the magnetic recording medium of the present invention.

FIG. 4 is a schematic diagram (corresponding to FIG. 1) showing the structure of another embodiment of the magnetic recording medium of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magnetic recording medium 2 Nonmagnetic support 3 Magnetic layer 4 Back coat layer 5 First thin film layer 6 Second thin film layer 7 First carbon thin film 8 Second carbon thin film 9 Nonmagnetic or magnetic coating layer

Claims (10)

[Claims] 1. A magnetic recording medium comprising: a nonmagnetic support; and a magnetic layer provided on the nonmagnetic support and containing a magnetic powder and a binder. A magnetic recording medium characterized in that thin film layers made of different materials are provided between the magnetic layer and on the surface of the non-magnetic support opposite to the magnetic layer. 2. The method according to claim 1, wherein the non-magnetic support is 350 to 1000
kg / mm ² Young's modulus and a polyester film having a thickness of 1.0～5.8Myuemu, claim 1 magnetic recording medium according. 3. The total thickness of the thin film layer is 0.1 to 1 μm.
The magnetic recording medium according to claim 1, wherein m is m. 4. A thin film layer provided between the nonmagnetic support and the magnetic layer is formed of a metal, a semimetal, or an alloy thereof, and is opposite to the magnetic layer in the nonmagnetic support. 4. The magnetic recording medium according to claim 1, wherein the thin film layer provided on the surface is formed of a metal or metalloid oxide, nitride, carbide, silicide, or a composite thereof. 5. The method according to claim 1, wherein the metal is Fe, Ni, Co, Ti,
W, Mo, Al, Mn, Cr, Cu, Zn, Zr and S
5. The magnetic recording medium according to claim 4, wherein the magnetic recording medium is at least one selected from the group consisting of n. 6. The method according to claim 1, wherein the metalloid is B, Si, Ge and Sb.
5. The magnetic recording medium according to claim 4, wherein the magnetic recording medium is at least one selected from the group consisting of: 7. The method according to claim 7, wherein the metal or metalloid is Fe, Ni,
Co, Ti, W, Mo, Al, Mn, Cr, Cu, Z
The magnetic recording medium according to claim 4, wherein the magnetic recording medium is an alloy selected from the group consisting of n, Zr, Sn, B, Si, Ge, and Sb. 8. A thin film mainly composed of carbon is provided on at least one surface of the thin film layer.
The magnetic recording medium according to claim 1. 9. The magnetic recording medium according to claim 1, wherein the carbon-based thin film is a diamond-like carbon film. 10. A non-magnetic or magnetic coating layer is provided between the thin film layer and the magnetic layer.
10. The magnetic recording medium according to any one of items 9.