JPH10143862A - Production of magnetic recording medium and apparatus therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lessen the yielding to heat and the degradation in a preservable property which are the drawbacks of high-frequency induction heating by improving the vapor deposition efficiency of an apparatus for production of magnetic recording media. SOLUTION: An evaporation vessel 11 is heated by a high-frequency induction heating coil 12 and an electron beam 32 emitted from an electron gun 30 is passed through the splashing space of vapor flow and is further reflected by a reflection plate 31. The electron beam is made incident on a base film 3. The film 3 is brought into tight contact with a cooling can 4 by the Coulomb force of the electron beam 32 and the heat by vapor deposition is made to well escape to the cooling can 4 and, therefore, the yielding of the film 3 to the heat is prevented. Further, the evaporated particles are ionized by the electron beam 32 and are, therefore, more easily adherable to the base film 3. The vapor deposition efficiency is thus improved as well.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a magnetic recording medium, and more particularly, to a method of heating and melting a magnetic material, evaporating the magnetic material, and depositing the vapor flow on a flexible substrate such as a base film. The present invention relates to a method for manufacturing a magnetic recording medium in which a magnetic recording layer is formed by a so-called vapor deposition process for growing.

[0002]

2. Description of the Related Art Conventionally, as a magnetic recording medium, γ-Fe
₂ O ₃ , Co-doped Fe ₃ O ₄ , γ-Fe ₂ O ₃
Magnetic material as a berthollide compound of Fe ₃ O _4, berthollide compound doped with Co, from CrO _3, Ba oxide magnetic material such as ferrite, or Fe, Co, an alloy magnetic material mainly composed of Ni or the like Are dispersed and mixed together with additives into a polymer binder such as a vinyl chloride-vinyl acetate copolymer, a styrene-butadiene copolymer, an epoxy resin, or a polyurethane resin, and the dispersion mixture is mixed with polyethylene terephthalate (PET) or the like. 2. Description of the Related Art A so-called coating type magnetic tape which is manufactured by coating a base film (substrate) made of a polyolefin such as polyester or polypropylene and then curing or drying the base film is widely known.

On the other hand, in recent years, the demand for higher recording density has become stronger, and the density of the magnetic material in the magnetic layer of the magnetic recording medium has been increased, the coercive force has been improved, the magnetic layer has been reduced in thickness, or the frequency characteristics have been shortened. Consideration has been given to shifting to the side.

However, in a coating type tape, it is difficult to satisfy the above-described various conditions required for high-density recording because a binder remains in the magnetic layer.

Therefore, attention has been paid to a method of manufacturing a magnetic recording medium by a vapor deposition method such as vacuum deposition, sputtering, or ion plating, or a plating method such as electroplating or electroless plating, and various proposals have been made. According to these methods, the magnetic layer can be formed by depositing and growing a magnetic material directly on a substrate without using a binder, so that the packing density of the magnetic material in the magnetic layer is increased, and Can also be made thinner.

Further, these vapor deposition methods and the like make it easy to adjust and control the thickness of the film formed on the base film, adjust the coating solution of the magnetic layer in the manufacturing process of the coating type tape, and perform drying after coating. This has practically useful advantages such as eliminating the need for processing steps associated with the formation of a magnetic layer.

[0007] In particular, the vapor deposition method has the advantages that the waste liquid treatment required in the plating method is not required and that the growth rate of the deposited magnetic film is high.
A magnetic tape using a magnetic layer formed on a base film by such a vapor deposition method as a recording layer has a much higher reproduction output and a shorter frequency characteristic of a recording signal than a conventional coating type magnetic tape. It is useful as a high-density magnetic recording medium, for example, it is improved on the wavelength side.

It is known that the manufacture of a magnetic recording medium by a vapor deposition method is performed in detail by, for example, a vacuum vapor deposition apparatus 1 shown in FIG. As shown in FIG.
A long base film 3 made of a non-magnetic material such as a polyester film, a polyamide film, or a polyimide film is formed inside a vacuum chamber 2 in a reduced pressure state. The cooling film 4 is wound in the direction Y. The cooling film 4 is rotated in the direction of arrow Y, and the base film 3 which is transferred from the side of the delivery shaft 5 to the side of the winding shaft 6 is provided on the outer peripheral surface of the cylinder. Conveyed.

The inside of the vacuum chamber 2 is controlled by a partition plate 7 to take up and wind up the base film 3 in a winding chamber 8.
And a deposition chamber 9 for depositing a magnetic material on the base film 3. In the vapor deposition chamber 9, Co, CoNi alloy, CoCr alloy, CoC
An evaporation container 11 containing a magnetic material 10 as an evaporation source such as an rNi alloy is provided, and the magnetic material 10 is heated and evaporated by heating means 12 such as electron gun heating, resistance heating, and high frequency induction heating. Particles of the magnetic material 10 (referred to as magnetic particles or evaporating particles), which evaporate and rise, are continuously deposited on the surface of the base film 3 conveyed in the direction of arrow Y with the rotation of the cooling can 4. They collide and deposit there by cooling, thus forming a magnetic layer.

Here, in order to efficiently deposit the evaporated magnetic material particles on the substrate to increase the vapor deposition efficiency, it is sufficient to prevent the evaporated particles from diffusing widely. According to the technique disclosed in Japanese Patent Application Laid-Open No. 2-56730, the portion between the evaporation source and the cooling can, around which the evaporated particles pass, is surrounded by a peripheral wall to regulate the flow path. In order to do so, for example, a steam diffusion control wall (steam diffusion control means) 15 having a cylindrical shape may be provided. The vapor diffusion control wall 15 has a temperature of the inner wall surface in order to re-evaporate or coagulate and collect the evaporated particles of the magnetic material 10 attached to the inner wall surface or to combine re-evaporation and coagulation and recovery. Is provided with means for heating or cooling.

When such a vapor diffusion control wall 15 is provided, it is difficult to use an electron gun heating means generally used as a heating means. That is, in this case, it is necessary to secure a passage of the electron beam from the electron gun to the magnetic material 10 placed in the evaporating vessel 11.
This is because, when the vapor diffusion control wall 15 is provided above the above, it is difficult to secure the passage trajectory of the electron beam. Therefore, high frequency induction heating means is usually used as the heating means.

The magnetic properties of the magnetic thin film formed on the base film by vapor deposition, particularly its coercive force, depend on the angle formed by the base film 3 when the vapor of the magnetic material 10 reaches the base film 3, ie, the evaporation container 11 The base film 3 of the magnetic material 10 scattered from inside toward the base film 3
Is determined by the angle of incidence on For this reason, usually, the cooling can 4 side of the evaporating vessel 11 (below the cooling can 4 in the figure).
Are provided with masks 13 and 14 serving as shielding members at a predetermined distance from the cooling can 4.
The maximum incident angle is regulated by the mask 13 located on the upstream side with respect to the transport direction, and the minimum incident angle is regulated by the mask 14 located on the downstream side, and the vapor of the magnetic material 10
Through the opening 18 formed by the base film 3 and 14, the liquid is supplied to the surface of the base film 3 from obliquely below in the drawing. The angle of incidence refers to an angle between the base film 3 and a straight line perpendicular to the surface of the base film 3.

It has been found that it is effective to spray oxygen during the vapor deposition in order to further improve the coercive force of the magnetic thin film. In the method of blowing oxygen, usually, a gas blowing unit 17 is provided near a mask 14 located on the downstream side in the transport direction of the base film 3 to blow oxygen gas to the evaporated particles of the magnetic material 10. It is done by. For example, according to the technology disclosed in Japanese Patent Publication No. 2-27732, the oxygen gas is blown from the vicinity of the minimum incident angle, and the inert gas is also blown from the vapor deposition start side (the maximum incident angle side). The filling rate and the magnetic filling rate are adjusted.

Although it is different from the purpose of improving the coercive force, oxygen gas is blown into the system during the vapor deposition also for the purpose of improving the corrosion resistance of the magnetic recording medium. For example, according to the technology disclosed in Japanese Patent Publication No. 3-19621, an oxidizing gas is sprayed into the system from a plurality of nozzles arranged in the width direction of a base film as a substrate to form an element constituting a magnetic layer. To form an oxide, and the oxide film of the oxide has a protective effect against corrosion.

On the other hand, in order to improve the production efficiency of a magnetic recording medium and the efficiency of vapor deposition of a magnetic material, a vacuum vapor deposition apparatus that heats an evaporation container by combining a method using electron gun heating and a method using induction heating has been proposed. (JP-A-5-219913). In this device, the evaporation energy of the magnetic material in the evaporation container is mainly given from the electron gun, and the energy due to the induction heating is transferred to the outside of the evaporation container out of the energy supplied as the evaporation energy from the electric gun as heat conduction or as radiation. It is used to supplement the energy that escapes. According to this apparatus, even if the output of the electron gun is reduced, the efficiency of vapor deposition of the magnetic material can be improved, so that a high-output electron gun is not required and the equipment cost can be reduced. Although the frequency of induction heating is relatively low, such as 30 to 50 Hz, a high frequency of, for example, 1 KHz is often used.

[0016]

However, in the heating method using an electron beam, the production efficiency of a magnetic recording medium or the vapor deposition efficiency of a magnetic material is low and the production cost is considerably required as described in JP-A-5-219913. Disadvantage. Although high-frequency induction heating can improve the vapor deposition efficiency as compared with the method using an electron beam, it has a problem in the process that heat loss easily occurs and a problem in quality that storage stability is inferior. Here, losing heat means
Among the wrinkles of the substrate (base film) generated during vapor deposition, those generated by thermal factors such as latent heat of evaporating particles and radiant heat from the evaporation container. Normally, the cooling can is cooled to about -30 ° C, and the substrate that comes into uniform contact with the surface can absorb heat (latent heat of evaporating particles and radiant heat from the evaporating vessel and scene) when the magnetic material adheres. By letting it escape to the cooling can side, its own temperature rise is suppressed. Here, if there is a portion where the base material is partially lifted from the cooling can, heat escape from the base material in that portion becomes worse, and the temperature of the base material increases. Thereafter, degassing from the substrate occurs as the temperature rises (both front and back of the substrate)
In addition, the temperature of the base material rises because the heat hardly escapes. On the other hand, since a tension is applied to the substrate in the transport direction, a portion where the substrate is softened due to a rise in the temperature of the substrate is elongated, and wrinkles are generated. The generation of the wrinkles is a heat loss.

In addition, the storability refers to the degree of deterioration of characteristics with respect to the environment of the medium, and is evaluated, for example, by corrosion due to sulfurous acid gas and change in surface reflectance under a high-humidity and high-temperature environment. The cause of the poor preservability of the magnetic recording medium deposited by high-frequency induction heating is considered to be the presence or absence of ionization of the evaporated particles or the introduced oxidizing gas molecules, or the effect of electron beam irradiation of the magnetic layer surface by reflected electrons.

Further, in the vacuum vapor deposition apparatus disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 5-271913, although the equipment cost can be reduced, the vapor deposition efficiency cannot be improved so much.

The present invention has been made in view of the above circumstances, and it is possible to further improve the vapor deposition efficiency, to prevent heat loss, which is a drawback of high-frequency induction heating, and to improve storage stability at the same time. It is an object of the present invention to provide a method and an apparatus for manufacturing a magnetic recording medium.

[0020]

According to a method of manufacturing a magnetic recording medium of the present invention, a long flexible substrate is transported in a vacuum atmosphere, and is disposed below a path along which the substrate is transported. The evaporation source made of the magnetic material is heated to evaporate the magnetic material, and the diffusion direction of the vapor flow generated between the evaporation source and the flexible substrate caused by the evaporation of the magnetic material is regulated and controlled. An incident angle regulating means for regulating the incident angle of the vapor flow to the flexible substrate, and controlling the directivity of the vapor flow and further oxidizing the vapor flow. Vaporizing the vapor flow on the surface of the flexible substrate while spraying a reactive gas onto the vapor flow,
In a method of manufacturing a magnetic recording medium on which a magnetic thin film is formed, an electron beam is applied to a region where the vapor flow is deposited on the long flexible support.

According to a first aspect of the present invention, there is provided a magnetic recording medium manufacturing apparatus, comprising: a conveying unit for conveying a long flexible substrate in a vacuum atmosphere; and a magnetic material disposed below the substrate. An evaporation source for heating and evaporating the evaporation source; and a cylinder disposed between the evaporation unit and the flexible substrate, for regulating and controlling the diffusion direction of the vapor flow heated and evaporated by the evaporation unit. Steam flow diffusion control means, incident angle regulating means for regulating the incident angle of the vapor flow to the flexible substrate, and gas blowing means for blowing an oxidizing gas to the vapor flow. In a magnetic recording medium manufacturing apparatus for forming a magnetic thin film on a flexible substrate, an electron beam generating means for generating an electron beam passing through the vapor flow, and an electron beam passing through the vapor flow, wherein the vapor flow To the long flexible substrate Is characterized in that a reflecting means for reflecting to be irradiated in the area to be deposited.

The second apparatus for manufacturing a magnetic recording medium according to the present invention comprises a transporting means for transporting a long flexible substrate in a vacuum atmosphere, and a magnetic material disposed below which the substrate is transported. An evaporation source for heating and evaporating the evaporation source; and a cylinder disposed between the evaporation unit and the flexible substrate, for regulating and controlling the diffusion direction of the vapor flow heated and evaporated by the evaporation unit. Steam flow diffusion control means, incident angle regulating means for regulating the incident angle of the vapor flow to the flexible substrate, and gas blowing means for blowing an oxidizing gas to the vapor flow. In a magnetic recording medium manufacturing apparatus for forming a magnetic thin film on a flexible substrate, an electron beam is
An electron beam generating means for irradiating an area where the vapor flow is vapor-deposited on the long flexible substrate is provided.

The surface of the reflecting means has a melting point of 2800
° K or higher metals, oxides, carbides, nitrides, borides,
It is preferable to use a silicide.

Further, it is preferable to provide a cooling means for cooling the reflection means.

Here, the term “evaporation source” means a source formed of a magnetic material, but in this specification, for convenience of explanation,
The evaporation source may be an evaporation source including an evaporation container containing a magnetic material.

[0026]

The first and second embodiments of the present invention will now be described.
In the magnetic recording medium manufacturing apparatus, the electron beam is reflected by the reflecting means or directly irradiates the region of the base material where the magnetic material is deposited, so that the electrons are injected into the base material and the space charge Will remain on the substrate. Thereby, a Coulomb force acts between the space charge and the opposing induced charge induced on the cooling means for cooling the substrate, whereby the substrate adheres to the cooling means, and the evaporated magnetic material Since the heat of the base material is satisfactorily released to the cooling means, heat loss of the base material does not occur. Further, the evaporating particles and the oxidizing gas for oxidizing the evaporating particles are also positively and negatively ionized by the electron beam, respectively, so that the oxidation of the evaporating particles by the oxidizing gas is promoted.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments for carrying out a method for manufacturing a magnetic recording medium according to the present invention will be described with reference to the drawings. FIG. 1 shows a schematic configuration of an embodiment of a magnetic recording medium manufacturing apparatus (vacuum vapor deposition apparatus) for carrying out the magnetic recording medium manufacturing method of the present invention.

The illustrated vacuum evaporation apparatus 1 has a cylindrical cooling can 4 inside a vacuum chamber 2, and a cylindrical film (outer peripheral surface) of the cooling can 4 has a base film as a base material of a magnetic recording medium. 3 is wound. The base film 3 is made of a polyester such as polyethylene terephthalate (PET) or polyethylene naphthalate, a polyolefin such as polypropylene, a cellulose dielectric such as cellulose triacetate or cellulose diacetate, a vinyl resin such as polyvinyl chloride,
It is formed by processing a plastic such as polycarbonate, polyamide, or polyphenylene sulfide into a long film, and the thickness thereof is, for example, 3 to 100 μm. In this embodiment, the one having a thickness of 6 μm is used.

An undercoat is applied to the surface of the base film 3 if necessary. The undercoat is made of a binder (cellulose such as methylcellulose, P
Saturated polyesters such as ET, phenoxy resins, polyamides, polyacrylates, etc.) and fillers (silica, titania, alumina, calcium carbonate, etc.) are dissolved and applied, and the surface projections have a height of 5 to 30 nm.
In those with a protrusion density 5000000-100000000 pieces / mm ^2. In this embodiment, the particle size is 18 μm and the density is 5500.
10,000 / mm ² . The height and density can be appropriately selected depending on the required adhesion performance and the like.

Further, the base film 3 may be subjected to a pretreatment such as a glow discharge treatment, an ion irradiation treatment, a heat treatment, and a chemical treatment.

The base film 3 is wrapped around the winding shaft 6 from the delivery shaft 5 through the cylindrical surface of the cooling can 4, and rotates on the cylindrical surface of the cooling can 4 by rotating the cooling can 4 in the direction of arrow Y. For example, it is conveyed at a speed of 10 to 100 m / min, and is taken up on a take-up shaft 6. The cooling can 4 has a diameter
It is a cylindrical drum of 600 mm and width of 220 mm. The surface is hard chrome plated and mirror-polished to 0.3 S or less. Cooling water and other refrigerant (ethylene glycol) are circulated inside. For example, it is maintained at −35 to + 25 ° C. (−28 ° C. in the present embodiment).

On the surface of the cooling can 4, masks 13 and 14 whose main body is formed of SUS304 or the like are provided, and the cooling water or the coolant is circulated inside the cooling can 4 at a predetermined distance. This distance is between 2 and 15 mm, more preferably between 2 and 10 mm, most preferably between 3 and 5 mm. 2mm
If it is narrower, the space for installing the first gas blowing section described later cannot be secured, and if it is more than 15 mm, the vapor flow goes between the mask and the base film and adheres to the cooling can 4, causing contamination. Because. This is because the heat transfer coefficient between the can and the base film changes in the portion where the dirt is generated, or the adhesion of the can to the base film becomes insufficient and the can becomes easily damaged by heat. The maximum incident angle (θmax) is defined by the mask 13 located on the upstream side in the transport direction of the base film 3 and the minimum incident angle (θmin) is defined by the mask 14 located on the downstream side in the transport direction of the base film 3. The angle of incidence is based on the center of the circle of the melted surface in the refractory crucible 11a, which will be described later. The maximum incident angle (θmax) regulated by the mask 13 is limited to 90 °, more preferably 87 °, most preferably 85 °, and the minimum incident angle regulated by the mask 14. It is desirable that the angle (θmin) is set so that the lower limit is 20 °, more preferably 25 °, and most preferably 30 °. This is because a desired coercive force cannot be obtained outside the above range. Mask 13
The opening width in the width direction (direction perpendicular to the transfer direction of the base film 3) of the mask opening 18 formed by the mask film 14 and the mask opening 14 can be arbitrarily set.

The masks 13 and 14 have a curved shape along the front surfaces of the masks 13 and 14, respectively.
And has a function of preventing the evaporated metal particles of the magnetic material 10 from adhering to the surface of the base material 3, circulating cooling water inside, and a movable type having a main body formed of SUS304 or the like. (Not shown).

The vacuum chamber 2 is provided with a winding chamber 8 for feeding and winding the base film 3 by a partition plate 7,
The base film 3 is partitioned into a deposition chamber 9 for depositing a magnetic material. Each of the winding chamber 8 and the vapor deposition chamber 9 is provided with an exhaust system (not shown) for reducing pressure, and the pressure in each chamber can be adjusted individually. In particular, since an oxidizing gas, which will be described later, is introduced into the vapor deposition chamber 9 from the outside of the vacuum chamber 2, the pressure in the chamber and the partial pressure of various residual gases are constantly adjusted by adjusting means (not shown).

The take-up chamber 8 contains the base film 3.
For the pre- and post-treatments described above, for example, glow discharge treatment device, ion irradiation treatment device, heat treatment device, C
A VD processing device or the like may be provided. In addition, cooling can 4
Is not limited to a cylindrical shape, and may be an endless belt-shaped metal plate capable of forming a predetermined slope with respect to the evaporating container 11.

An evaporating vessel 11 containing a magnetic material 10 is disposed below the cooling can 4 in the vapor deposition chamber 9.
Around the periphery of 11, a high-frequency induction heating coil 12 having a tubular structure through which cooling water circulates for heating the magnetic material 10 is provided. Further, a high frequency power supply 20 for supplying high frequency power to the high frequency induction heating coil 12 and a high frequency power supply feeder 21 for transmitting high frequency power are provided.

The magnetic material 10 is made of, for example, Fe, Co, Ni,
CoNi, FeCo, FeCu, FeCr, CoCr,
CoCu, CoAu, CoPt, CoW, NiCr, C
oV, MnBi, MnAl, CoFeCr, CoNiC
r, CoRh, CoNiPt, CoNiFe, CoNi
It is appropriately selected from ferromagnetic metals and ferromagnetic alloys such as FeB, FeCoNiCr, and CiNiZn.

The magnetic material 10 which is a component of the evaporation vessel 11
The refractory crucible 11a for containing MgO, ZrO
₂ , Al ₂ O ₃ , CaO, Y ₂ O ₃ , ThO ₂ , BN,
BeOCaO stabilized ZrO ₂ , Y ₂ O ₃ stabilized ZrO ₂
And other materials having heat resistance, such as ceramics, carbon or carbon compounds, and other materials having heat resistance. In addition, this refractory crucible 11
The shape of a is a container type having a bottom, and the horizontal cross-sectional shape may be a perfect circle, an ellipse, an oval, a square, a rectangle, or any other shape, and the vertical cross-section is also a square.
It may be rectangular, trapezoidal, or any other shape.
Preferably, the high-frequency induction heating coil 12 has a shape corresponding to the side surface of the refractory crucible 11a.

Further, the evaporation chamber 9 is located between the cooling can 4 and the evaporation vessel 11 provided with the magnetic material 10,
A steam flow diffusion control means 15 is provided as means for preventing the diffusion of steam so as to surround a path through which a steam flow generated by evaporation of the gas passes. In the vicinity of 14, there is provided a gas blowing unit 17 for blowing a mixed gas of an acidifying gas or an oxidizing gas and an inert gas toward the base film 3.

The gas spraying section 17 is located downstream with respect to the transport direction of the base film 3 and is built in the surface of the mask 14 on the side of the cooling can 4 near the mask 14 that regulates the minimum incident angle (θmin). ing. In addition, O ₂
Gas was used. The blowing direction of the gas blowing slit 17a is substantially parallel to a tangent line on the cooling can 4 at a reference point on the cooling can 4 which defines the minimum incident angle (θmin). Relative scattering direction of the evaporation particles that has passed through the opening of the steam flow diffusion control means 15 which will be described later by spraying O ₂ gas from the gas blowing part 17, in a substantially diagonal direction of the O ₂ gas is blown evaporated metal particles one Oxidize parts.

The inner peripheral wall of the vapor flow diffusion control means 15 is made of, for example, MgO, ZrO ₂ , Al ₂ O ₃ , CaO, Y ₂ O ₃ ,
ThO ₂ , BN, BeOCaO stabilized ZrO ₂ , Y ₂ O
₍₃₎ A steam flow path formed of ceramics such as stabilized ZrO ₂ , carbon or a carbon compound, or other heat-resistant material, and surrounded by a regulating surface extending substantially vertically in a state substantially continuous with the refractory crucible 11a. Are arranged so that
The lower surface and the upper surface are cylindrical so as to allow the passage of evaporated particles of the magnetic material 10 and improve the directivity thereof, and have a cylindrical shape having only a peripheral wall, and have a horizontal cross-sectional shape of a circle, an ellipse, an oval, and a square. , A rectangle, or any other shape. The vertical cross-section may also be square, rectangular, trapezoidal, or any other shape.

Further, the vapor flow diffusion control means 15 is, for example,
From the center of the opening toward the outside, concentric circles of the inner wall 15a,
It has a laminated structure composed of a plurality of members such as two layers of the outer peripheral portion 15c.

Further, an electron gun 30 is provided on the wall surface of the vacuum chamber 2, and an electron beam 32 emitted from the electron gun 30 passes above the opening of the vapor flow diffusion control means 15, which is a space where evaporation particles are scattered. Thereafter, the electron beam is applied to an electron beam reflector 31 provided between the mask 14 near the evaporation vessel 11 and the vapor diffusion control means 15, and then the diffused reflected electrons are diffused into the base film 3.
Irradiated on the deposition surface of. The maximum output of the electron gun 30 is 30K
W.

As shown in FIG. 3, the electron beam reflecting plate 31 is a reflecting plate 31a (W120 mm × L) whose surface is made of Mo.
The cooling block 31b is made of oxygen-free copper and has a structure in which cooling water circulates inside.
And a seal member 31c from which the cooling water does not leak. The electron beam reflector 31 is inclined to efficiently irradiate the irradiated electron beam 32 to the deposition surface of the base film 3.

[0045]

In this embodiment, the refractory crucible 11a has a cup shape (inner diameter φ80 mm, outer diameter φ96 mm, height 100 mm,
(Internal depth is 90 mm) and the material is Y ₂ O ₃ stabilized ZrO _{2
(ZrO 2; 88.0% ~95.0%} , Y 2 O 3; 5.0% ~12.0
%). Co ₉₅ Ni ₅ was used as a ferromagnetic material 10 for evaporation inside the refractory crucible 11a.

The high-frequency induction heating coil 12 is made of a Cu pipe having a diameter of φ12 mm through which cooling water circulates. The high-frequency induction heating coil 12 has eight turns, an inner diameter of φ120 mm, and a height h105 mm. Two high frequency power supplies 20 having an oscillation frequency of 25 kHz and an output of 40 kW are provided outside the vacuum chamber 2, and two high frequency power sources provided inside the vacuum chamber 2 through a high frequency feeder 21 and a vacuum feedthrough (not shown). Connected to heating coil 12. The high-frequency feeder 21 is made of a Cu plate, and the extended Cu pipe portions of the high-frequency induction heating coil 12 are each surrounded by an insulating tube made of Al ₂ O ₃ and are electrically insulated from each other.

The inner wall 15a of the vapor diffusion control means 15 has a cylindrical shape (inner diameter φ80 mm, outer diameter φ96 mm, height h90 mm).
aO stabilized ZrO ₂ (ZrO ₂ ; 90.0% to 98.0%, Ca
O; 2.0% ~7.0%, MgO , Al 2 O 3, SiO 2,
Each component of FeO ₃ and TiO ₂ was 0.0% to 2.0%).

The outer peripheral portion 15c has a cylindrical shape (inner diameter φ96 mm, outer diameter φ140 mm, height h90 mm), circulates cooling water of 18 ° C. inside, and has a main body formed of oxygen-free copper. Was used.

Next, the operation of the magnetic recording medium manufacturing apparatus of this embodiment will be described.

First, a gas such as air in the vapor deposition chamber 9 and the winding chamber 8 is exhausted to the outside by a decompression means (not shown) such as a vacuum pump. For example, 5.0 × 10 ^{-5 to} 4.0 × 10 ^-4 To
The pressure is reduced to rr. In this example, 5.0
× 10 ^-5 Torr. After the insides of the vapor deposition chamber 9 and the winding chamber 8 are depressurized as described above, power is supplied to the high-frequency induction heating coil 12 using the high-frequency power supply 13, whereby the high-frequency induction heating coil 12 generates heat and evaporates. 11 magnetic materials 10
Was heated and evaporated.

After the magnetic material 10 is completely dissolved and the evaporation rate becomes constant, the base film 3 is moved by the delivery shaft 5.
At a transport speed of 60 m / min and a tension of 2.0 kgf / 100 mm. In a pretreatment chamber (not shown), the side of the base film 3 on which the magnetic thin film is formed is subjected to glow discharge treatment using O ₂ gas. After the application, it is transported on the cooling can 4.
Then, the shutter device is driven to an "open" state. Then, the electron gun 30 is operated to allow the electron beam to pass above the opening of the vapor flow diffusion control means 15, and then is irradiated on the surface of the electron beam reflector 31 (irradiation range is W80 mm × L180 mm). At this time, the output of the high-frequency induction heating power supply 20 is, for example, 22 KW, and the output of the electron gun 30 is 10 KW. At the same time the gas blowing part 17 spray amount 300 cc / min, width O ₂ gas of the first layer on the base film 3 while blowing CoNi-
After forming an O magnetic thin film (thickness 700 Å), it is continuously wound around the winding shaft 6 to form a metal magnetic thin film having a length of 3000 m. The blowing of O ₂ gas from 17, the supply of power from the high-frequency power supply 20 and the stopping of the electron gun 30 were stopped, and the film formation of the first layer was completed.

The web once wound on the winding shaft 6 is as follows:
The paper is sent out from the winding shaft 6 by the reverse rotation operation, and is rewound on the feeding shaft 5. Thereafter, a second layer of Co—O magnetic thin film (thickness: 700 Å) is formed by the same vapor deposition method described above, and a two-layer magnetic thin film (total thickness of 14 Å) is formed.
00 angstroms).

After depositing a magnetic thin film on the base film 3 and correcting the curl of the magnetic layer by a heat treatment, the surface of the magnetic thin film is formed as a phosphoric acid monoester compound as C ₁₂ H _25.
A solution of OPO ₃ H ₂ in methyl ethyl ketone was applied so that the coating amount on the magnetic layer was 20 μmol / m ² and dried. Subsequently, a resin composition comprising carbon black and a resin binder is applied to the surface opposite to the surface on which the magnetic layer has been formed, and dried to form a backcoat layer.As a fatty acid ester compound on this backcoat layer, C ₈ F ₁₇ COOC ₁₈
Applying a solution of H ₃₇ in ethanol so that the 20 [mu] mol / m ^2, was wound up dry. The above process is performed by varying the outputs of the high-frequency induction heating coil 12 and the electron gun 30 to obtain a raw material on which a magnetic thin film is formed, and the raw material is cut into an 8 mm width to obtain a magnetic recording medium for evaluation. Created.

Then, the following preservability and heat loss were evaluated.

[Evaluation Method of Storage Property] (1) The magnetic recording medium was stored for 72 hours in an environment of 27 ° C., 80% RH, and 1 ppm of sulfur dioxide gas. Is not observed, the metal gloss on the entire surface of the tape is retained but corrosion is observed, and the magnetic layer is partially or wholly dissolved by corrosion.

(2) The tape was stored in an environment of 60 ° C. and 90% RH in a reel wound state for 72 hours, and the visible light reflectance of the portion in contact with the back surface was measured and compared with the reflectance before the test. .

[Method of Evaluating Heat Loss] The occurrence of heat loss was visually observed on the front surface side by irradiating visible light from the back side of the vapor-deposited raw material having a width of 100 mm and a length of 3000 m. The inspection position was investigated for 1000 m between 1000 m and 2000 m based on the evaporation start position.

The evaluation criteria are as follows: a double circle indicates no heat loss, a circle indicates no heat loss within ± 30 mm from the center in the base width direction, and a continuous heat loss (longitudinal direction). Is not recognized, but the heat loss caused by itself is less than 10 places. The continuous heat loss is not recognized, but the heat loss caused alone is not recognized.
△ ×, heat loss continuously in 10 or more places (longitudinal direction)
(Having a length of 20 mm or more) was evaluated as x, and those in which wrinkles were constantly generated due to heat loss were evaluated as xx. Table 1 below shows the results of evaluating the storage stability and heat loss.

The total weight W _{ms of the} ferromagnetic material 10 before melting is W _ms
Evaporation total amount from the difference between (g) and W _me of deposition after the end of the residual material (g) W to calculate the _mev (g), based the total weight of the pre-deposition to the base of the post-deposition to the total weight W _{be (g)} From the difference, the total vapor weight W _bev (g) is calculated. And the total evaporation amount W _mev
If the ratio of the total weight W _bev (g) of vapor deposition to (g) is defined as vapor deposition efficiency ξ (%), the relationship is as shown in the following equation.

Ξ (%) = W _bev (g) / W _mev (g) × 100 (%) The input power of the high-frequency induction heating source was kept constant at 22 KW.

[0061]

[Table 1]

As shown in Table 1, the electron beam 32 was applied to the reflector 31.
By irradiating the base film 3 with reflection, the electron beam is not irradiated at all, that is, as compared with the case of heating only by high-frequency induction heating, the vapor deposition efficiency is not so much changed, but the heat loss and storage stability (SO ₂ corrosion resistance)
Was found to improve.

In the above-described embodiment, as shown in FIG. 1, after the electron beam passes through the scattering space of the evaporating particles in the high-frequency induction heating evaporation container 11, the electron beam is reflected by the reflection plate 31 and irradiated on the base film 3. However, the present invention is not limited to this. For example, as shown in FIG. 3, the electron beam 32 is first reflected by the reflector 31 and then the reflected electron beam 32 is scattered in the scattering space of the evaporated particles. The light may be passed through and the base film 3 may be irradiated.

Here, the embodiment shown in FIG. 3 is different from the embodiment shown in FIG. 1 in the following points. That is, the electron reflected by the reflector 31 is generally 30% of the power of the original electron beam.
It is attenuated below, and its diffusion range is greatly expanded. Therefore, in the case of the embodiment shown in FIG.
The main purpose is to irradiate the scattering space of the evaporating particles with the electron beam 32 before irradiating the reflecting plate 31 to promote ionization of the evaporating particles or the oxidizing gas.
The main purpose of the reflected electrons after the reflection is to inject charges into the base film 3 by irradiating an electron beam when forming a deposited film on the base film 3. On the other hand, in the embodiment shown in FIG. 3, the electron beam is first spread over a wide space by irradiating the reflector 31 with the electron beam, so that the electron beam is applied to the base film 3 when the deposited film is formed on the base film 3 surface. The main purpose is to inject charges.

Further, in addition to the embodiment shown in FIGS. 1 and 3, an electron gun is provided without providing a reflecting plate as shown in FIG.
The electron beam 32 generated from 30 may be directly applied to the base film 3. in this case,
For example, the output of the high-frequency induction heating power supply 20 is 22 kW and the electron gun 30
Output is 0.5 kW, irradiation area is 120 mm width and length
400 mm (including the mask part). In the embodiment shown in FIG. 4, in addition to the electron gun 30, an ion gun may be used to perform both ion irradiation and electron beam irradiation.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of an apparatus for manufacturing a magnetic recording medium according to the present invention.

FIG. 2 is a diagram for explaining cooling of a reflection plate;

FIG. 3 is a diagram showing another embodiment of a magnetic recording medium manufacturing apparatus according to the present invention.

FIG. 4 is a diagram showing still another embodiment of a magnetic recording medium manufacturing apparatus according to the present invention.

FIG. 5 is a diagram showing a conventional magnetic recording medium manufacturing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magnetic recording medium manufacturing apparatus (vacuum vapor deposition apparatus) 2 Vacuum tank 3 Base film 4 Cooling can 5 Delivery axis 6 Winding axis 7 Partition plate 8 Winding chamber 9 Deposition chamber 10 Magnetic material 11 Evaporation vessel 11a Refractory crucible 12 High frequency Induction heating coils 13, 14 Mask 15 Vapor flow diffusion control means 17 Gas spray section 18 Mask opening 30 Electron gun 31 Reflector 32 Electron beam

Claims (3)

[Claims] 1. A method for transporting a long flexible substrate in a vacuum atmosphere, and heating an evaporation source made of a magnetic material disposed below a path along which the substrate is transported, thereby forming the magnetic material. Through a vapor flow diffusion control means provided between the evaporation source and the flexible substrate, which regulates and controls the diffusion direction of the vapor flow generated by the evaporation of the magnetic material. The incident angle restricting means for restricting the incident angle to the flexible substrate is provided to control the directivity of the vapor flow, and further, while blowing the oxidizing gas onto the vapor flow, A method of manufacturing a magnetic recording medium, wherein a magnetic thin film is formed by vapor deposition on a surface of a flexible substrate, wherein an electron beam is irradiated to a region where the vapor stream is vapor-deposited on the long flexible support. Of manufacturing magnetic recording medium 2. A transport means for transporting a long flexible substrate in a vacuum atmosphere, an evaporation source made of a magnetic material disposed below which the substrate is transported, and heating and evaporation of the evaporation source. Evaporating means, and a cylindrical vapor flow diffusion control means disposed between the evaporating means and the flexible substrate, for regulating and controlling the diffusion direction of the vapor flow heated and evaporated by the evaporating means,
Forming a magnetic thin film on the flexible substrate, the device comprising: an incident angle regulating unit for regulating an incident angle of the vapor flow to the flexible substrate; and a gas blowing unit for blowing an oxidizing gas to the vapor flow. An apparatus for producing a magnetic recording medium, comprising: an electron beam generating means for generating an electron beam passing through the vapor flow; and an electron beam passing through the vapor flow.
Reflecting means for reflecting the vapor flow so as to irradiate an area to be deposited on the long flexible substrate, the apparatus for manufacturing a magnetic recording medium. 3. A transport means for transporting a long flexible substrate in a vacuum atmosphere, an evaporation source made of a magnetic material disposed below which the substrate is transported, and heating and evaporating the evaporation source. Evaporating means, and a cylindrical vapor flow diffusion control means disposed between the evaporating means and the flexible substrate, for regulating and controlling the diffusion direction of the vapor flow heated and evaporated by the evaporating means,
Forming a magnetic thin film on the flexible substrate, the device comprising: an incident angle regulating unit for regulating an incident angle of the vapor flow to the flexible substrate; and a gas blowing unit for blowing an oxidizing gas to the vapor flow. An apparatus for manufacturing a magnetic recording medium, comprising: an electron beam generating means for irradiating an electron beam to a region where the vapor flow is deposited on the long flexible substrate. apparatus.