JPH1150240A - Production of magnetic recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a magnetic recording medium having a high output, good adhesion of magnetic coating and enough durability by specifying the running rate of a supporting body and the current density of an electron beam to be applied to magnetic metal and to evaporate the magnetic metal. SOLUTION: By a vacuum oblique deposition device, a magnet metal evaporating source is irradiated with an electron beam to evaporate magnetic metal, and the evaporated magnetic metal is vapor-deposited on a running supporting body (PET film) 1 to form magnetic coating, where the running rate of the supporting body is regulated to 5 to 200 m/min, and the current density of the electron beam is regulated to 1 to 8 A/cm<2> . As the current density of the electron beam is made high of >1 A/cm<2> , magnetic coating of high output can be obtd., but, in the case that it is made excessive of >8 A/cm<2> , the supporting body is subjected to heat damage and is made defective. As for the running rate of the supporting body, even if the current density of the electron beam lies in the above range, in the case that it is excessive, magnetic coating of high output can not be obtd. to reduce the bindability and durability of the magnetic coating, therefore, the above range is regulated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for manufacturing a magnetic recording medium.

[0002]

2. Description of the Related Art Conventionally, as a magnetic film provided on a support, not a coating type using a binder resin,
A metal thin film type without using a binder resin has been proposed. This metal thin film type magnetic recording medium has a high packing density of a magnetic material and is suitable for high density recording.

As a method of manufacturing a metal thin film type magnetic recording medium, particularly a method of forming a metal thin film type magnetic film, wet plating means such as electroless plating, dry plating means such as vacuum evaporation, sputtering or ion plating. It has been known. Above all, the vacuum evaporation method has a high magnetic film formation rate. Therefore, there are many proposals for a method of manufacturing a magnetic recording medium by a vacuum evaporation method.

However, a magnetic film formed by a vacuum deposition method has a weaker adhesion to a support and is less durable than a magnetic film formed by a sputtering method. For these reasons, researches on improving durability have been actively conducted. For example, Japanese Patent Publication No. 18371/1992 discloses a method of manufacturing a magnetic recording medium by depositing a ferromagnetic material on a substrate that continuously moves in a vacuum atmosphere. There is disclosed a method for manufacturing a magnetic recording medium, which comprises irradiating an electron beam having a beam current density of up to 0.6 A / cm ² to perform evaporation.

According to this technique, it is claimed that a magnetic film having excellent adhesion and still durability can be obtained.

[0006]

However, it is not sufficient for the magnetic recording medium to have only a good magnetic film adhesion and still durability. First, the power must be high. In particular, the output must be high in a short wavelength region suitable for high-density recording.

In this respect, Japanese Patent Publication No. 4-18371
Technology was not enough. Accordingly, an object of the present invention is to provide a technique capable of efficiently producing a magnetic recording medium having high output, good magnetic film binding property, and high durability.

[0008]

An object of the present invention is to form a magnetic film by irradiating a magnetic metal evaporation source with an electron beam to evaporate the magnetic metal and depositing the evaporated magnetic metal on a running support. In the method for manufacturing a magnetic recording medium, the running speed of the support is 5 to 200 m / min, and the current density of the electron beam is 1 to 8 A / cm ² . Will be resolved.

In particular, in a method for manufacturing a magnetic recording medium, a magnetic film is formed by irradiating a magnetic metal evaporation source with an electron beam to evaporate the magnetic metal and depositing the evaporated magnetic metal on a running support to form a magnetic film. The traveling speed of the support is 5 to 200
m / min, and the electron beam is scanned in a width direction of the support orthogonal to a running direction of the support, the scan width is 0.20 to 1.5 m, and the current density of the electron beam is Is 1 to 8 A / cm ² .

Further, the present invention provides a method for manufacturing a magnetic recording medium, comprising irradiating a magnetic metal evaporation source with an electron beam to evaporate the magnetic metal and depositing the evaporated magnetic metal on a running support to form a magnetic film. The traveling speed of the support is 5 to 20;
0 m / min, the electron beam is scanned in the width direction of the support orthogonal to the running direction of the support, and the electron beam is also scanned in the running direction of the support orthogonal to the scanning direction; The scan width in the width direction of the support is 0.20 to 1.5 m, and the scan width in the running direction of the support is 0.1 to 1.5 m.
03 to 0.30, and the current density of the electron beam is 1
-8 A / cm < ² >.

That is, when irradiating a magnetic metal evaporation source with an electron beam to evaporate the magnetic metal and deposit the evaporated magnetic metal on a running support to form a magnetic film,
As we investigated the relationship between the traveling speed of the support and the intensity of the electron beam irradiated on the magnetic metal evaporation source, there was a close relationship between these and the output characteristics and the binding and durability of the magnetic film. I came across something.

That is, the current density of the electron beam is 1 A / c
It has been found that a higher output can be obtained as the value exceeds m ² . However, when the current density of the electron beam was too large, exceeding 8 A / cm ² , the support was damaged by heat and became defective. Thus, when the current density of the electron beam applied to the magnetic metal evaporation source is 1 to 8 A / cm ² , a high-output magnetic film can be obtained,
Moreover, this magnetic film was rich in binding properties and durability. Further, in such a case, the formation (production) efficiency of the magnetic film was also high.

Even if the current density of the electron beam applied to the magnetic metal evaporation source is 1 to 8 A / cm ² , a high output magnetic film can be obtained if the running speed of the support is too high. In addition, the binding property and durability of the magnetic film were low. When the traveling speed of the support was low, the production efficiency of the magnetic film was low. From such a thing,
The current density of the electron beam irradiating the magnetic metal evaporation source is 1 to
8A / cm ² and the running speed of the support 5
It has been found that control at ~ 200 m / min is important from the viewpoints of output characteristics, binding property / durability of the magnetic film, and productivity.

The current density of the electron beam applied to the magnetic metal evaporation source is more preferably 1.5 to 6.0 A / cm ² . The traveling speed of the support is 50 to
More preferably, the speed was 100 m / min. That is, by further limiting the current density of the electron beam and the traveling speed of the support, it was possible to obtain a magnetic film excellent in output characteristics, binding property and durability with high productivity.

Further, in consideration of the productivity of the magnetic film, it is preferable that the electron beam is scanned in the width direction of the support orthogonal to the running direction of the support. In addition, this scanning of the electron beam efficiently forms a uniform magnetic film in the width direction of the support. Therefore, it is preferable to scan the electron beam in the width direction of the support orthogonal to the running direction of the support. However, if the scan width is too large, the magnetic film cannot be manufactured efficiently. In addition, the binding property and durability of the obtained magnetic film were low. From such a viewpoint, when the current density of the electron beam applied to the magnetic metal evaporation source is controlled to 1 to 8 A / cm ² and the traveling speed of the support is controlled to 5 to 200 m / min, the support of the electron beam The scan width in the width direction was preferably 0.2 to 1.5 m.

For the same reason, the scan width in the traveling direction of the support is 0.03 to 0.30 m, particularly 0.03 to 0.30 m.
Scanning to be 3-0.15 m was preferred. The thickness of the support may be basically any. However, those having a size of 5 μm or less were preferred.
That is, when considering a large-capacity tape, if the thickness exceeds 5 μm and is too thick, the total thickness becomes large and the volume becomes large. However, if it is too thin, the degree of thermal damage during vapor deposition is large, and
2 μm because it is difficult to run the support at a constant speed
It is preferable that the thickness is not less than the above.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for manufacturing a magnetic recording medium according to the present invention
Irradiates the magnetic metal evaporation source with an electron beam to convert the magnetic metal
Evaporate and deposit the evaporated magnetic metal on a moving support
Method for manufacturing a magnetic recording medium in which a magnetic film is formed by
And the traveling speed of the support is 5 to 200 m / min.
50 to 100 m / min) and the electron beam
Current density of 1 to 8 A / cm^Two(Especially, 1.5 to 6.0.
A / cm^Two). In particular, electron beam
Irradiation of the magnetic metal to evaporate the magnetic metal,
Magnetic recording to form a magnetic film by vapor deposition on a moving support
In the method for manufacturing a recording medium, the running speed of the support may be 5
Up to 200 m / min (particularly 50 to 100 m / min)
Where the width of the support is orthogonal to the running direction of the support.
The electron beam is scanned in the direction
The scan width is 0.20 to 1.5 m.
Current density of 1 to 8 A / cm^Two(Especially, 1.5-6.
0A / cm ^Two). Furthermore, the electron is transferred to the magnetic metal evaporation source.
The magnetic metal is evaporated by irradiating the beam, and the evaporated magnetic gold
Magnetism to form a magnetic film by vapor deposition on a metal-supporting support
In the method for manufacturing a gas recording medium, the traveling speed of the support is
Is 5 to 200 m / min (particularly, 50 to 100 m / mi
n), of the support orthogonal to the running direction of the support.
In the width direction, the electron beam is scanned and
In the running direction of the support orthogonal to the scanning direction.
Even if the electron beam is scanned, the width of the support
The scan width in the direction is 0.20 to 1.5 m,
The scan width in the running direction of the support is 0.03 to
0.30m (especially 0.03-0.15m)
The current density of the electron beam is 1 to 8 A / cm^Two(Especially,
1.5 to 6.0 A / cm^Two).

Hereinafter, this will be described in more detail. [Support] As a support on which a magnetic film, particularly a vapor deposition type magnetic film is provided, a known support in the technical field can be used without particular limitation. In particular,
Known resins such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyphenylene sulfide, polycarbonate, polyamide, polyimide, polyamide imide, polysulfone, aramid, and aromatic polyamide; metals such as aluminum and copper;
Paper, ceramics, and the like can be used. The form is
Any of a film, a tape, a sheet, a disk, a drum and the like may be used. Before the magnetic film is provided on the support, the surface thereof may be subjected to corona discharge treatment, plasma treatment, easy adhesion treatment, heat treatment, dustproof treatment, bombardment treatment, or the like in the air and / or in vacuum. The thickness of the support is preferably 2 to 5 μm. The reason is as described above.

[Magnetic Film, Especially Metal Thin Film (Evaporation Type) Magnetic Film] For forming the magnetic film, a known metal thin film forming means can be used. However, the present invention employs a vapor deposition method.
In particular, an oblique deposition method is used. That is, as shown in FIG. 1, a vacuum oblique deposition apparatus is used. In FIG. 1, 1 is a support, 2 is a cooling can roll, 3a is a supply-side roll of the support 1, 3b is a take-up roll of the support 1, 4 is a crucible, and 5 is a crucible filled in the crucible 4. Magnetic metal, 6 is an electron gun, 7 is a shielding plate, and 8 is an oxygen gas supply nozzle. still,
These are arranged in a vacuum chamber.

In order to form a magnetic film on the support 1 using the above-described vacuum oblique deposition apparatus, first, the inside of the vacuum chamber is set to 1 × 10 ^-4 to
Evacuate to 1 × 10 ⁻⁶ Torr. And support 1
From the supply side roll 3a along the cooling can roll 2, and is wound up by the winding side roll 3b. At this time,
The traveling speed of the support 1 is 5 to 200 m / min, especially 30
It is controlled to １００100 m / min.

The ferromagnetic metal 5 filled in the crucible 4 is irradiated with an electron beam from the electron gun 6 to evaporate the ferromagnetic metal, and the evaporated ferromagnetic metal particles along the cooling can roll 2. It is deposited on the running support 1. At this time, the current density of the electron beam from the electron gun 6 is 1 to 8 A /
cm ² , especially 1.5 to 6.0 A / cm ² .

Here, the current density of the electron beam is defined as follows. The current is an emission current of the electron gun. Between the emission current, the output of the electron gun, and the acceleration voltage, the output (w) of the electron gun =
There is a relationship of acceleration voltage (v) × emission current (A), and the value of the emission current is obtained from the output of the electron gun and the set value of the acceleration voltage. The value obtained by dividing the value of the emission current by the area value is the current density of the electron beam in the present invention. The area value is the size of the electron beam immediately after exiting from the main body of the electron gun 6 (the area in a cross section in a direction perpendicular to the direction of irradiation of the electron beam).

Therefore, the control of the current density of the electron beam is
This is performed by controlling the output of the electron gun, the acceleration voltage, and the degree of aperture of the electron beam. Specifically, the current density of the electron beam is 1 to 8 A / cm ² , particularly 1.5 to 6.0.
The output of the electron gun 6 is set to 30 to 30 so as to satisfy A / cm ^2.
This is achieved by controlling the power to 0 kw, the acceleration voltage to 10 to 40 kv, and the size of the electron beam to about 0.2 to 3.2 cm ² .

Also, by adjusting the positions of the crucible 4 and the shielding plate 7,
The incident angle when the evaporated ferromagnetic metal particles are deposited on the support 1 running along the cooling can roll 2, that is, the maximum incident angle is 90 ° to 80 °, and the minimum incident angle is 60 ° to 40 °.
Set to °. As the ferromagnetic metal forming the magnetic film, for example, in addition to metals such as Fe, Co, and Ni, C
o-Ni alloy, Co-Pt alloy, Co-Ni-Pt
Alloy, Fe-Co alloy, Fe-Ni alloy, Fe-
Co-Ni-based alloy, Fe-Co-B-based alloy, Co-Ni
-Fe-B-based alloys, Co-Cr-based alloys, or alloys containing a metal such as Al are used. Further, these oxides, nitrides, carbides and the like are also used.

The magnetic film may be composed of a single metal thin film or a laminate of two or more metal thin films. When the magnetic film is composed of two or more metal thin films,
The material of each metal thin film may be the same or different. The magnetic film obtained in the present invention has an overall thickness of 0.3 mm.
1 to 0.2 μm.

[Protective Film] The protective film 12 is formed on the magnetic film shown in FIG.
Is provided. Examples of the protective film include carbon, boron carbide, silicon carbide, boron nitride, silicon nitride, silicon oxide, chromium oxide, and aluminum oxide. Among them, a carbon film having a diamond bond and a graphite bond is preferable. Particularly, a diamond-like carbon film having a diamond bond and a graphite bond is preferable. The protective film has a thickness of 3 to 15 nm. In particular, if the thickness is 5-10
nm.

The diamond-like carbon film is made of, for example, an ECR (Electron Cyclottr) shown in FIG.
on Resonance) Plasma CVD (Chem)
The electrode can be formed by using an electrical vapor deposition (IC) device. In FIG. 3, reference numeral 21 denotes a support provided with the magnetic film 11, reference numeral 22 denotes a cooling can roll, reference numeral 23a denotes a supply-side roll of the support 21, reference numeral 23b denotes a winding-side roll of the support 21, reference numeral 24 denotes a vacuum tank, 25 is a plasma reaction tube, 26 is a magnet, 27 is a raw material supply nozzle, and 28 is a microwave waveguide. The conditions for forming the diamond-like carbon film are, for example, that the traveling speed of the support 21 is 5 to 50 m / m.
in, the temperature of the cooling can roll 22 is 20 to 60 ° C., μ
Wave output is 300 ~ 1000w and 2 × 10 ^-5 ~ 2
The ratio of the raw material supplied from the nozzle 27 to the plasma reaction tube 25 disposed in the vacuum chamber having a vacuum degree of × 10 ⁻⁷ Torr is set to 1.2 × 10 ⁻² to 1.2 × 10 ⁻⁵ Torr. It controls so that it becomes. The raw material is a hydrocarbon gas such as methane, ethylene, acetylene, benzene, etc., particularly a chain-like unsaturated hydrocarbon having a double or triple bond such as ethylene or acetylene, benzene, toluene, benzoic acid, benzaldehyde, etc. Cyclic unsaturated hydrocarbons (aromatic hydrocarbons), and other hydrocarbon-based compounds having an unsaturated bond, such as those obtained by diluting naphthalene or anthracene in benzene or toluene. . In addition to these raw materials, it is preferable to use a rare gas such as hydrogen or argon, carbon dioxide, or nitrogen.

[Back Film] A so-called back film 13 is provided on the surface of the support opposite to the surface on which the magnetic film is formed, in order to improve the running properties and durability of the magnetic recording medium. . As the back film, either a coating type or a metal thin film type may be used. In general, a metal thin film type back film is
It is formed by depositing a non-magnetic metal such as Al, Cu, Si, Fe, Mo, Mn, Zn, etc., or an alloy, oxide, nitride, or carbide thereof by PVD means such as vapor deposition. The thickness of the back film is 0.1 to 0.5 μm.

[Lubricant] After the back film and the protective film are formed, a film of a lubricant, particularly a fluorine-based lubricant, is provided to a thickness of about 20 to 100 nm by means such as immersion or ultrasonic spraying. As a fluorine-based lubricant, for example, HOOC-CF ₂
(OC ₂ F ₄ ) _p (OCF ₂ ) _q -OCF ₂ -COOH, F- (CF ₂ CF ₂ CF ₂ O) _n -C
Carboxyl group-modified perfluoropolyether called F ₂ CF ₂ COOH, HOCH ₂ -CF ₂ (OC ₂ F ₄ ) _p (OCF ₂ ) _q -OCF ₂ -CH ₂
Alcohol-modified perfluoropolyether called OH,
In addition, a molecule in which a saturated hydrocarbon group such as an alkyl group or the like, an unsaturated hydrocarbon group, an aromatic hydrocarbon group, or another functional group is attached to one or a part of the molecules is used. Specifically, the brand name FOMB of Montecatini
LIN Z DIAC, FOMBLIN Z DOL,
Daikin Industries Co., Ltd. brand name Demnum SA and the like.

Hereinafter, the present invention will be described with reference to specific examples.

[0031]

Example 1 A support (a surface roughness Ra on the side on which a magnetic film is formed is 2 nm, a surface roughness Ra on the opposite side is 5 nm, a width is 0.5 m and a thickness is 0.5 mm). 6μ
The magnetic film 11 was formed on the (m PET film) 1.
The conditions for forming the magnetic film are as follows.

Traveling speed of the support 1; 30 m / min ferromagnetic metal; Co vacuum degree of vacuum chamber; 1.0 × 10 ⁻⁶ Torr output of the electron gun 6; 60 kW current density of the electron beam from the electron gun 6; 1.8A / cm ² emission current; 2A electron beam size; scan width of the electron beam in the traveling direction of the 0.6m support;; 1.13 cm ² scan width of the electron beam in the width direction of the support 0m ferromagnetic 90 ° Minimum incident angle of ferromagnetic metal particles; 60 ° Oxygen gas supply from nozzle 8; 420 sccm Thickness of magnetic film 11 formed under the above conditions is 0.18 μm
Met. The coercive force Hc was 1,480 Oe, the saturation magnetic flux density Bs was 6,200 G, and the squareness ratio Sq was 0.88.

Next, the PET on which the magnetic film 11 is formed
The film 1 was loaded into the ECR plasma CVD apparatus shown in FIG. 3, and a diamond-like carbon film 12 having a diamond bond and a graphite bond was formed on the magnetic film 11. On the surface opposite to the magnetic film 11, a thickness of 0.5 μm made of a binder resin containing carbon black is used.
Of the back film 13 was formed.

Then, a lubricant (FO of Montecatini) was used.
MBLIN Z DIAC) was applied to a thickness of 50 nm to form a lubricant layer 14. The raw material of the magnetic recording medium obtained as described above was cut into a predetermined width to obtain a magnetic tape shown in FIG.

[0035]

Example 2 A magnetic tape was obtained according to the method of Example 1, except that the conditions for forming the magnetic film 11 were changed as follows. Current density of the electron beam than 60kw electron gun 6; output of 1.0 × 10 ^-6 Torr electron gun 6; 30 m / min ferromagnetic metal; Co degree of vacuum in the vacuum vessel traveling speed of the support 1 2.5A / cm ² emission current; of 2A electron beam size; of 0m ferromagnetic metal particles; 0.78 cm ² scan width of the electron beam in the width direction of the support; 0.6 m scan width of the electron beam in the traveling direction of the support Maximum incident angle: 90 ° Minimum incident angle of ferromagnetic metal particles: 60 ° Oxygen gas supply from nozzle 8: 450 sccm The thickness of the magnetic film 11 formed under the above conditions is 0.18 μm.
Met. The coercive force Hc was 1500 Oe, the saturation magnetic flux density Bs was 6150 G, and the squareness ratio Sq was 0.89.

[0036]

Example 3 A magnetic tape was obtained according to the method of Example 1, except that the conditions for forming the magnetic film 11 were changed as follows. 37 m / min Ferromagnetic metal; Co Degree of vacuum in vacuum chamber; 1.0 × 10 ⁻⁶ Torr Output of electron gun 6; 75 kW Current density of electron beam from electron gun 6; / cm ² emission current; 2.5A electron beam size; 0.2 m little; scan width of the electron beam in the traveling direction of the 0.6m support; 1.13 cm ² scan width of the electron beam in the width direction of the support Maximum incident angle of magnetic metal particles: 90 ° Minimum incident angle of ferromagnetic metal particles: 60 ° Oxygen gas supply from nozzle 8: 530 sccm The thickness of magnetic film 11 formed under the above conditions is 0.18 μm.
Met. The coercive force Hc was 1530 Oe, the saturation magnetic flux density Bs was 5900 G, and the squareness ratio Sq was 0.90.

[0037]

Example 4 A magnetic tape was obtained according to the method of Example 1, except that the conditions for forming the magnetic film 11 were changed as follows. Traveling speed of support 1; 50 m / min ferromagnetic metal; Co vacuum degree of vacuum chamber; 1.0 × 10 ^-6 Torr output of electron gun 6; 90 kW current density of electron beam from electron gun 6; / cm ² emission current; 3A electron beam size; scan width of the electron beam in the traveling direction of the 0.6m support;; 1.13 cm ² scan width of the electron beam in the width direction of the support 0.2m ferromagnetic metal Maximum incident angle of particles: 85 ° Minimum incident angle of ferromagnetic metal particles: 60 ° Oxygen gas supply from nozzle 8: 690 sccm The thickness of the magnetic film 11 formed under the above conditions is 0.18 μm.
Met. The coercive force Hc was 1500 Oe, the saturation magnetic flux density Bs was 5850 G, and the squareness ratio Sq was 0.87.

[0038]

Example 5 A magnetic tape was obtained according to the method of Example 1, except that the conditions for forming the magnetic film 11 were changed as follows. Traveling speed of the support 1; 55 m / min ferromagnetic metal; vacuum degree of the Co vacuum chamber; 1.0 × 10 ⁻⁶ Torr output of the electron gun 6; 102 kw current density of the electron beam from the electron gun 6; ² Emission current; 3.4 A Size of electron beam; 1.13 cm ² Scan width of electron beam in the width direction of the support; 0.6 m Scan width of electron beam in the running direction of the support; 0 m Maximum incident angle; 90 ° Minimum incident angle of ferromagnetic metal particles; 55 ° Oxygen gas supply from nozzle 8; 720 sccm The thickness of the magnetic film 11 formed under the above conditions is 0.17 μm.
Met. The coercive force Hc was 1520 Oe, the saturation magnetic flux density Bs was 6110 G, and the squareness ratio Sq was 0.90.

[0039]

Example 6 A magnetic tape was obtained according to the method of Example 1, except that the conditions for forming the magnetic film 11 were changed as follows. Traveling speed of support 1; 70 m / min ferromagnetic metal; Co vacuum degree of vacuum chamber; 1.0 × 10 ^-6 Torr output of electron gun 6; 130 kW current density of electron beam from electron gun 6; / cm ² emission current; of 4.3A electron beam size; of 0m ferromagnetic metal particles; 0.78 cm ² scan width of the electron beam in the width direction of the support; 1 m scan width of the electron beam in the traveling direction of the support Maximum incident angle; 90 ° Minimum incident angle of ferromagnetic metal particles; 60 ° Oxygen gas supply from nozzle 8; 930 sccm The thickness of the magnetic film 11 formed under the above conditions is 0.18 μm.
Met. The coercive force Hc was 1,480 Oe, the saturation magnetic flux density Bs was 6,080 G, and the squareness ratio Sq was 0.89.

[0040]

Example 7 A magnetic tape was obtained according to the method of Example 1, except that the conditions for forming the magnetic film 11 were changed as follows. Traveling speed of the support 1; 80 m / min ferromagnetic metal; Co vacuum degree of the vacuum chamber; 1.0 × 10 ⁻⁶ Torr output of the electron gun 6; 141 kW current density of the electron beam from the electron gun 6; ² Emission current; 4.7 A Electron beam size; 0.78 cm ² Scan width of electron beam in the width direction of the support; 1 m Scan width of electron beam in the running direction of the support; 0.2 m Maximum incident angle; 85 ° Minimum incident angle of ferromagnetic metal particles; 55 ° Oxygen gas supply from nozzle 8; 1100 sccm The thickness of the magnetic film 11 formed under the above conditions is 0.17 μm.
Met. The coercive force Hc was 1460 Oe, the saturation magnetic flux density Bs was 5990 G, and the squareness ratio Sq was 0.84.

[0041]

Example 8 A magnetic tape was obtained according to the method of Example 1, except that the conditions for forming the magnetic film 11 were changed as follows. Traveling speed of the support 1; 100 m / min; ferromagnetic metal; degree of vacuum in a Co vacuum chamber; 1.0 × 10 ⁻⁶ Torr output of the electron gun 6; 180 kW current density of the electron beam from the electron gun 6; / cm ² emission current; 5.9A electron beam size; scan width of the electron beam in the traveling direction of 1m support;; 0.78 cm ² scan width of the electron beam in the width direction of the support 0.2m ferromagnetic metal Maximum incident angle of particles; 90 ° Minimum incident angle of ferromagnetic metal particles; 60 ° Supply amount of oxygen gas from nozzle 8; 1300 sccm The thickness of the magnetic film 11 formed under the above conditions is 0.17 μm.
Met. The coercive force Hc was 15,10 Oe, the saturation magnetic flux density Bs was 6,170 G, and the squareness ratio Sq was 0.88.

[0042]

Comparative Example 1 A magnetic tape was obtained in the same manner as in Example 1 except that the following conditions among the conditions for forming the magnetic film 11 in Example 1 were changed as follows. Traveling speed of the support 1; 15 m / min output of the electron gun 6; 17 kw current density of the electron beam from the electron gun 6; 0.5 A / cm ² emission current; 0.57 A oxygen gas supply from the nozzle 8; The thickness of the magnetic film 11 formed under the above conditions is 0.17 μm
Met. The coercive force Hc was 1500 Oe, the saturation magnetic flux density Bs was 5700 G, and the squareness ratio Sq was 0.89.

[0043]

Comparative Example 2 A magnetic tape was obtained in the same manner as in Example 1 except that the following conditions among the conditions for forming the magnetic film 11 in Example 1 were changed as follows. Traveling speed of the support 1; 19 m / min output of the electron gun 6; 20 kw current density of the electron beam from the electron gun 6; 0.6 A / cm ² emission current; 0.68 A oxygen gas supply from the nozzle 8; 210 sccm The thickness of the magnetic film 11 formed under the above conditions is 0.18 μm.
Met. The coercive force Hc was 1520 Oe, the saturation magnetic flux density Bs was 5620 G, and the squareness ratio Sq was 0.88.

[0044]

Comparative Example 3 The method of Example 1 was followed, except that the conditions for forming the magnetic film 11 in Example 1 were changed as described below. Current density of 210kw electron beam from the electron gun 6;; 9A / cm ² emission current; output of 15 m / min electron gun 6; traveling speed of the support 1 7A electron beam size; 0.78 cm ² the width of the support member 1 m Scan width of electron beam in the direction of travel; 1 m Scan width of electron beam in the direction of travel of the support; 0.2 m Maximum incident angle of ferromagnetic metal particles; 85 ° Minimum incident angle of ferromagnetic metal particles; 55 ° From nozzle 8 Oxygen gas supply amount; 190 sccm

[0045]

Comparative Example 4 A magnetic tape was obtained in the same manner as in Example 1 except that the conditions described below among the conditions for forming the magnetic film 11 in Example 1 were changed as follows. Running speed of the support 1; 210 m / min Scanning width of the electron beam in the running direction of the support; 0.2 m Minimum incident angle of the ferromagnetic metal particles; 55 ° Oxygen gas supply amount from the nozzle 8; 2120 sccm The thickness of the magnetic film 11 is 0.035 μm.
m. The coercive force Hc was 1500 Oe, the saturation magnetic flux density Bs was 5710 G, and the squareness ratio Sq was 0.90.

[0046]

[Characteristics] With respect to the magnetic tape obtained in each of the above examples, the output when information having a recording wavelength of 2 μm, 1 μm, 0.5 μm, and 0.25 μm was reproduced was examined. The results are shown in Table 1. The reproduction output is a head tester device shown in FIG. 4 (using a Hi8 VCR / EP head and a track width of 15).
μm, effective gap length 0.23 μm).

Further, the binding properties of the magnetic film were also examined, and the results are also shown in Table 1. In addition, the binding property was evaluated by performing a peeling test using an electric insulating tape No. 56 manufactured by Scotch, and when the tape side had 10% or more of the total area after the peeling test, the result was indicated by x. Further, the formation efficiency (productivity) of the magnetic film was also examined, and the results are also shown in Table 1. The productivity is expressed by the ratio of the line speed when obtaining a film having the same thickness.
This is a relative ratio when 1 is set to 1. As the value is larger, more magnetic films can be formed in the same time, so that the productivity is higher.

Table 1 Reproduction output (dB) binding productivity Productivity 2 μm 1 μm 0.5 μm 0.25 μm Example 1 0.6 0.8 1.0 1.4 ○ 2.0 Example 2 0.8 1 1.5 1.7 2.3 2.0 Example 3 0.7 1.2 1.6 2.1 2.5 Example 4 1.2 1.6 2.2 2.7 3.3 Example 5 1.8 2.1 2.6 3.2 3.7 Example 6 2.1 2.6 2.9 3.6 ○ 4.7 Example 7 2.6 2.9 3.7 4.2 ○ 5.3 Example 8 1.4 1.8 2.1 2.9 ○ 6.7 Comparative Example 100 000 × 1 Comparative Example 2 0.0 0.0 0.2 0.3 × 1.3 Comparative Example 3 Due to thermal damage, magnetic tape could not be formed and could not be evaluated Comparative Example 4 -4.5 -3.2 -2.0 -1.2 × 2.9 * Production of Comparative Example 4 The properties are calculated assuming that the film thickness is 0.17 μm. From Table 1, it can be seen that the device according to the present invention has excellent output characteristics. In particular, in the case of short wavelength recording in which the shortest recording wavelength is 0.33 μm or less, the reproduction output is extremely high. In addition, the magnetic film is firmly bound to the support, so that a material having high durability is obtained. Further, it can be seen that the productivity of the magnetic film is high.

[0049]

When the magnetic metal evaporation source is irradiated with an electron beam to evaporate the magnetic metal and deposit the evaporated magnetic metal on a running support to form a magnetic film, the running speed of the support is reduced to 5%. And the current density of the electron beam irradiating the magnetic metal evaporation source is 1 to 8 A / min.
cm ² , a magnetic film having a high reproduction output is formed, and the magnetic film has good binding to the support, is durable, and has high productivity and high quality. A magnetic recording medium is obtained.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a vacuum oblique deposition apparatus.

FIG. 2 is a schematic sectional view of a magnetic recording medium.

FIG. 3 is a schematic diagram of an ECR plasma CVD apparatus.

FIG. 4 is a schematic diagram of a head tester device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Support 11 Co deposited metal magnetic film 12 Protective film

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takeshi Miyamura 2606 Akabane, Kaigamachi, Haga-gun, Tochigi Pref.

Claims (5)

[Claims] 1. A method for manufacturing a magnetic recording medium, comprising: irradiating an electron beam to a magnetic metal evaporation source to evaporate the magnetic metal; and depositing the evaporated magnetic metal on a running support to form a magnetic film. A method for manufacturing a magnetic recording medium, wherein a traveling speed of a support is 5 to 200 m / min, and a current density of the electron beam is 1 to 8 A / cm ² . 2. A method for manufacturing a magnetic recording medium, comprising: irradiating a magnetic metal evaporation source with an electron beam to evaporate the magnetic metal; and depositing the evaporated magnetic metal on a running support to form a magnetic film. The traveling speed of the support is 5 to 200 m / min, and the electron beam is scanned in a width direction of the support orthogonal to the traveling direction of the support, and the scan width is 0.20 to 1.5 m. A method for manufacturing a magnetic recording medium, wherein the current density of the electron beam is 1 to 8 A / cm ² . 3. A method of manufacturing a magnetic recording medium, comprising irradiating an electron beam to a magnetic metal evaporation source to evaporate the magnetic metal and depositing the evaporated magnetic metal on a running support to form a magnetic film. The traveling speed of the support is 5 to 200 m / min, and the electron beam is scanned in the width direction of the support perpendicular to the traveling direction of the support, and in the traveling direction of the support perpendicular to the scanning direction. The electron beam is also scanned, and the scan width in the width direction of the support is 0.20 to 0.20.
1.5 m, and the scan width in the running direction of the support is 0.03 to
0.30, and the current density of the electron beam is 1 to 8 A / cm ² . 4. The method for manufacturing a magnetic recording medium according to claim 1, wherein the support has a thickness of 2 to 5 μm. 5. The method for manufacturing a magnetic recording medium according to claim 1, wherein a magnetic recording medium having a minimum recording wavelength of 0.33 μm or less used for recording is manufactured.