JPH09209129A - Production of magnetic recording medium and apparatus for production therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an inexpensive magnetic recording medium by continuously supplying a magnetic material into a vacuum chamber form the atm. outside the vacuum chamber. SOLUTION: A ferromagnetic material 9, such as metal or alloy, used as the constituting material of a ferromagnetic metallic thin film is continuously supplied from the atm. outside the vacuum chamber 1 into a vapor deposition source at the time of forming the ferromagnetic metallic thin film by a vacuum thin film forming technique on a nonmagnetic base 2. The means for supplying this ferromagnetic material 9 is preferably a differential discharge mechanism or the like constituted in such a manner that the difference between the atm. pressure and the pressure in the vacuum chamber is maintained constant by plural discharge means.

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 manufacturing method and a manufacturing apparatus suitable for use in forming a magnetic layer composed of a ferromagnetic metal thin film on a non-magnetic support by a vacuum thin film forming technique. .

[0002]

2. Description of the Related Art For example, in the field of magnetic recording such as a video tape recorder, there is a strong demand for higher density, and as a magnetic recording medium corresponding to this, metal, Co--Ni alloy, Co--Cr alloy is required. A ferromagnetic metal material such as Co, O or Co is directly coated on a non-magnetic support such as a polyester film, polyamide or polyimide film by plating or vacuum thin film forming technology (vacuum deposition method, sputtering method, ion plating method, etc.). A so-called metal magnetic thin film type magnetic recording medium in which a magnetic layer is formed by wearing the magnetic recording medium has been proposed and attracted attention.

This metal magnetic thin film type magnetic recording medium is excellent in coercive force, squareness ratio and the like, and the thickness of the magnetic layer can be made extremely thin, so that the thickness loss during recording demagnetization and reproduction is extremely small and electromagnetic waves at short wavelengths are reduced. Not only is it excellent in conversion characteristics, but since it is not necessary to mix a binder, which is a non-magnetic material, in the magnetic layer, it has various advantages such that the packing density of the magnetic material can be increased. For this reason, it is considered that this metal magnetic thin film type magnetic recording medium becomes the mainstream of high density magnetic recording due to its superior magnetic characteristics.

In such a metal magnetic thin film type magnetic recording medium, in order to improve the electromagnetic conversion characteristics and achieve higher output, the magnetic material forming the magnetic layer is supported non-magnetically when forming the magnetic layer. A so-called oblique vapor deposition method is used in which vapor deposition is performed obliquely to the surface of the body.

When manufacturing a magnetic recording medium by this oblique vapor deposition method, the vapor flow evaporated from the vapor deposition source is covered with a shutter or a mask to make a predetermined incidence on the surface of the non-magnetic support which is the object to be processed. Excellent magnetic characteristics and electromagnetic conversion characteristics are realized by using only the vapor deposition components that have an angle and are obliquely incident. Therefore, extra vapor deposition components other than the vapor deposition component having a predetermined incident angle with respect to the surface of the non-magnetic support adheres to the water-cooled shutter or mask, and is cleaned and discarded after the vapor deposition is completed. ing.

Further, in this oblique vapor deposition method, continuous vapor deposition is generally performed for a long time in order to improve productivity. Under such circumstances, it is necessary to continuously or intermittently supply the metal or alloy as the constituent material of the magnetic layer.

As a method of supplying such a metal or alloy, a wire having a diameter of 10 mm or less is generally used.
The wire method that continuously feeds from the upper part of the crucible, the pellet feeding method that puts the metal or alloy material in the form of pellets with a diameter of about 10 mm and a length of about several tens of mm into the crucible at regular intervals, a rod with a diameter of 60-80 mm A rod feed method or the like is used in which the metal or alloy material processed into the above is continuously raised from the lower part of the crucible.

[0008]

However, in any of the above-mentioned metal or alloy supply methods, there are the following problems.

That is, in the wire method, the processing cost for processing a metal or alloy into a wire (wire shape) is high and the alloy cost is high.

Similarly, in the pellet feeding system, the metal or alloy is once processed into a wire shape and the wire is cut into a certain length, so that the processing cost is high and the metal or alloy in the crucible is supplied at the time of supplying to the crucible. There are problems such as rampage and splash of hot water.

Further, although the rod feed method is superior to the above two in terms of processing cost, it is necessary to adopt a structure in which a material with a large diameter is supplied from the bottom of the crucible or from the side, and the vapor deposition apparatus becomes large. Has the drawback of being unavoidable.

Further, in these supply methods, the metal or alloy is set in the vacuum chamber for each batch of vapor deposition, and is supplied and arranged in the vacuum chamber before evacuation.

Therefore, when the supply is interrupted due to the abnormal shape of the magnetic material or the trouble of the supply mechanism occurs, the evaporation is interrupted, the vacuum chamber is returned to the atmospheric pressure, and after the recovery, the vacuum is exhausted again before the evaporation. I have to restart.

If the wire-shaped alloy (metal) or rod-feed alloy (metal) is not manufactured to a length (an integral multiple of) used in one vapor deposition, a fraction is generated and the fraction is regenerated. Since it is necessary to perform processing such as dissolution, the rate of waste is large and improvement is required from the viewpoint of cost.

Therefore, the present invention has been proposed in view of such circumstances, and an inexpensive magnetic recording medium is obtained by continuously supplying a magnetic material into the vacuum chamber from the atmosphere outside the vacuum chamber. An object of the present invention is to provide a method and an apparatus for manufacturing a magnetic recording medium that can be obtained.

[0016]

Means for Solving the Problems The inventors of the present invention have made earnest studies that they cannot achieve the above-mentioned object, and as a result, a mechanism for continuously supplying a magnetic material from the atmosphere outside the vacuum chamber is installed to form a film. By doing, without spending the processing cost of the magnetic material,
The present inventors have completed the present invention by finding that efficient continuous vapor deposition becomes possible and an inexpensive magnetic recording medium can be manufactured.

That is, the method of manufacturing a magnetic recording medium according to the present invention is the same as the method of manufacturing a magnetic recording medium in which a ferromagnetic metal thin film is formed on a non-magnetic support by a vacuum thin film forming technique. At this time, the metal or alloy used as the constituent material of the ferromagnetic metal thin film is continuously supplied from the atmosphere outside the vacuum chamber.

Further, the magnetic recording medium manufacturing apparatus of the present invention is a magnetic recording medium manufacturing apparatus for forming a ferromagnetic metal thin film on a non-magnetic support by a vacuum thin film forming technique. It is characterized by having a mechanism for continuously supplying the metal or alloy used as the above from the atmosphere outside the vacuum chamber.

The magnetic recording medium manufactured by the manufacturing method and manufacturing apparatus of the present invention is a so-called metal magnetic thin film type in which a ferromagnetic metal thin film is formed as a magnetic layer on a non-magnetic support by a vacuum thin film forming technique. A magnetic recording medium may be used.

In the above-mentioned metal magnetic thin film type magnetic recording medium, the non-magnetic support and the ferromagnetic material forming the ferromagnetic metal thin film are all those conventionally used in this type of magnetic recording medium. It is possible and is not particularly limited.

As a specific example, examples of the ferromagnetic material include ferromagnetic metal materials such as Co-Ni alloy, Co-Cr alloy, and Co-O. In addition, Fe, Co, N
Ferromagnetic metals such as i, Fe-Co, Co-O, Fe-Co
-Ni, Fe-Cu, Co-Cu, Co-Au, Co-
Pt, Fe-Cr, Co-Cr, Ni-Cr, Fe-C
o-Cr, Co-Ni-Cr, Fe-Co-Ni-Cr
It is also possible to use a ferromagnetic alloy or the like.

The magnetic layer may be a single layer film of a ferromagnetic metal thin film made of these ferromagnetic materials or a multi-layer film.

In addition, between the non-magnetic support and the ferromagnetic metal thin film, or in the case of a multilayer film, an underlayer or an intermediate layer is provided in order to improve the adhesive force between the layers and control the coercive force. May be provided. Further, for example, the vicinity of the surface of the magnetic layer may be an oxide in order to improve the corrosion resistance.

As a means for forming this ferromagnetic metal thin film, a vacuum vapor deposition method in which the above-mentioned ferromagnetic metal material is heated and evaporated under vacuum to be deposited on the above-mentioned non-magnetic support is suitable. A so-called PVD method such as an ion plating method in which evaporation of a metal material is performed in a discharge can be used.

A protective film layer may be formed on the ferromagnetic metal thin film thus formed.

The constituent material of the protective film layer may be any material as long as it is usually used in this kind of magnetic recording medium. To give a concrete example,
Carbon, CrO ₂ , Al ₂ O ₃ , BN, Co oxide, M
gO, SiO ₂ , Si ₃ O ₄ , SiNx, SiC, SiN
_{x-SiO 2, ZrO 2,} TiO 2, TiC , and the like.

The protective film layer may be a single layer film or a multilayer film made of these protective film layer materials.

In the present invention, the ferromagnetic material is continuously supplied from the atmosphere outside the vacuum chamber when forming the ferromagnetic metal thin film. As a result, continuous vapor deposition can be efficiently performed without requiring the processing cost of the ferromagnetic material. Therefore, the cost can be reduced, and an inexpensive magnetic recording medium can be manufactured. Further, since this method is a simple method of supplying the raw material, it can be mounted on an existing manufacturing apparatus relatively easily, and can be manufactured at low cost even when newly manufactured.

Of course, the structure of the magnetic recording medium manufactured according to the present invention is not limited to this, and may be changed without departing from the scope of the present invention, for example, a back coat layer may be formed if necessary. There is no problem in forming the undercoat layer on the non-magnetic support or forming various layers such as a lubricant and a rust preventive. In this case, as the non-magnetic pigment, the resin binder, the material contained in the lubricant layer, etc. contained in the back coat layer, any conventionally known materials can be used.

[0030]

EXAMPLES The present invention will be described below with reference to specific examples, but it goes without saying that the present invention is not limited to these examples.

Example 1 First, the structure of a continuous winding type vacuum vapor deposition apparatus used when forming the magnetic layer of the magnetic tape manufactured in this example will be described.

As shown in FIG. 1, this continuous winding type vacuum vapor deposition apparatus has an exhaust port 1 provided at the head and the bottom, respectively.
5 is exhausted and the inside is in a vacuum state (here, the degree of vacuum is 7 × 1).
It was set to 0 ^-2 Pa. ) Is provided inside the vacuum chamber 1, a feed roll 3 that rotates at a constant speed in the clockwise direction in FIG. 1 and a winding roll 4 that also rotates at a constant speed in the clockwise direction are provided.
The tape-shaped non-magnetic support 2 which is the object to be processed is sequentially run from the feed roll 3 toward the winding roll 4.

A winding roll 4 from the side of the feed roll 3
In the middle part where the non-magnetic support 2 travels over the side,
The non-magnetic support 2 is provided so as to be pulled out downward in FIG. 1, and the cooling can 5 having a diameter larger than that of each of the rolls 3 and 4 is rotated at a constant speed in the clockwise direction in FIG. It is provided.

The cooling can 5 is constructed so as to be cooled to a predetermined temperature by a cooling means (not shown) provided inside, and runs along the outer peripheral surface of the cooling can 5. The non-magnetic support 2 is prevented from being deformed due to a temperature rise during vapor deposition.

The feed roll 3, the winding roll 4 and the cooling can 5 each have a cylindrical shape having a length substantially the same as the width of the non-magnetic support 2.

Therefore, in this vacuum vapor deposition apparatus, the non-magnetic support 2 is sequentially fed from the feed roll 3, passes along the outer peripheral surface of the cooling can 5, and is further wound on the winding roll 4. It is designed to be taken.

Guide rolls 6 and 7 are provided between the feed roll 3 and the cooling can 5 and between the cooling can 5 and the take-up roll 4, respectively. From the cooling can 5 and the non-magnetic support 2 traveling from the cooling can 5 to the winding roll 4 while applying a predetermined tension thereto, the non-magnetic support 2 smoothly travels. .

In the vacuum chamber 1, a crucible 8 is disposed below the cooling can 5, and the crucible 8 is filled with a ferromagnetic material 9.

A differential evacuation mechanism 19 is provided in the vacuum chamber 1 so as to penetrate the side wall of the vacuum chamber 1.
9, the ferromagnetic material 9 is continuously supplied to the end portion of the crucible 8 from the atmosphere outside the vacuum chamber 1.

As shown in FIG. 2, the differential evacuation mechanism 19 has a cylindrical ferromagnetic material introducing pipe 20 into which a ferromagnetic material 18 having an appropriate shape is introduced, and the ferromagnetic material introducing pipe 20 has the above-mentioned structure. Ferromagnetic material supply means 21 for continuously supplying the ferromagnetic material 18 and a plurality (for example, three) exhaust means 22, 23, 2 for maintaining a constant pressure difference between the atmospheric pressure and the vacuum chamber 1.
And 4.

The ferromagnetic material introducing pipe 20 is designed so that the clearance between the ferromagnetic material introducing pipe 20 and the ferromagnetic material 18 introduced through the introducing port 20a from the ferromagnetic material supplying means 21 becomes as small as possible, and The length of the material introducing pipe 20 itself is preferably long. As a result, conductance can be increased and the degree of vacuum can be maintained.

In this embodiment, a rod-shaped material having a predetermined diameter (for example, 6 mm) is used as the ferromagnetic material 18, and a ferromagnetic material introducing pipe 20 into which the ferromagnetic material 18 is introduced has an inner diameter of 6.5 mm. The length was about 1500 mm.

At this time, since the ferromagnetic material 18 is wound in a coil shape as a raw material, it is straightened (shaped) before being introduced into the ferromagnetic material introducing pipe 20. Need to supply.

The supply rate of the ferromagnetic material 18 is
There is no reduction in the level of the crucible 8 due to evaporation of the ferromagnetic material 18 supplied to the end of the crucible 8 from the surface of the crucible 8 (that is, the level of the level of the crucible 8 is constant). Adjusted accordingly.

Further, the exhaust means 22, 23, 24 are
The ferromagnetic material introducing pipes 20 are attached to the middle portions of the ferromagnetic material introducing pipes 20 at predetermined intervals. These exhaust means 22, 2
As 3 and 24, various pumps can be used and are not limited at all. However, in order to improve the degree of vacuum in order from the atmosphere side, those arranged closer to the vacuum chamber 1 are preferred. It is preferable to use a highly accurate one. In the present embodiment, a rotary pump is used as the first exhaust means 22 and a second exhaust means 23 in order from the atmosphere side.
A roots pump was used as the above, and a turbo molecular pump was used as the third exhaust means 24.

Therefore, in this vacuum vapor deposition apparatus, the ferromagnetic material 18 is introduced from the ferromagnetic material supply means 21 through the introduction port 20a of the ferromagnetic material introduction pipe 20, and the ferromagnetic material introduction pipe 20 is introduced. While the pressure difference between the atmospheric pressure and the vacuum chamber 1 is kept constant while passing through, the atmosphere outside the vacuum chamber 1 is continuously supplied to the end of the crucible 8. Continuous vapor deposition can be performed efficiently. This makes it possible to manufacture an inexpensive magnetic recording medium by simply attaching the differential evacuation mechanism 19 as described above to the existing manufacturing apparatus.

On the other hand, an electron gun 10 is externally attached to the side wall of the vacuum chamber 1 as a means for heating and evaporating the ferromagnetic material 9 filled in the crucible 8. The electron beam X emitted from the electron gun 10 is arranged at a position where it is irradiated onto the ferromagnetic material (here, Co ₉₀ Ni ₁₀ is used) 9 in the crucible 8. The vapor flow heated and melted by the electron gun 10 and evaporated from the crucible 6 is vapor-deposited on the non-magnetic support 2 traveling along the outer peripheral surface of the cooling can 5 to form a magnetic layer. It is designed to be.

Here, the electron beam X normally emitted from the electron gun 10 is made uniform in the vapor distribution in the width direction by scanning the electron beam X in the width direction at a constant period, but in the present embodiment, the ferromagnetic material 18 is used. Since the vapor deposition rate is low on the end side of the crucible 8 to which is supplied, the scanning conditions of the electron beam X were changed to control the vapor distribution in the width direction to be uniform.

Further, a shutter 13 is arranged in the vicinity of the cooling can 5 between the cooling can 5 and the crucible 8. The shutter 13 is formed so as to cover a predetermined region of the non-magnetic support 2 traveling along the outer peripheral surface of the cooling can 5, and is only on the surface of the non-magnetic support 2 exposed from the shutter 13. A vapor stream evaporated from the crucible 6 is vapor-deposited. That is, the shutter 13 regulates the incident angle of the vapor flow evaporated from the crucible 6 with respect to the surface of the non-magnetic support 2, and the non-magnetic support 2 within a predetermined angle range.
The oblique deposition will be performed on the surface of the.

Further, an oxygen gas introduction port 8 of oxygen gas introduced in order to miniaturize the particles of the ferromagnetic metal thin film obtained at the time of such vapor deposition is provided so as to penetrate the side wall of the vacuum chamber 1. To be done. Oxygen gas is supplied to the surface of the non-magnetic support 2 through the oxygen gas inlet 8 to improve the magnetic characteristics, durability and weather resistance.

A partition plate 16 is arranged in a substantially central portion of the vacuum chamber 1 so as to divide the region where the crucible 6 is provided and the region where the feed roll 3 and the take-up roll 4 are provided. Set up. A tape feeding / winding chamber 11 (upper side in FIG. 1) in which the non-magnetic support 2 is fed or wound in the vacuum chamber 1 by the partition plate 16
And a vapor deposition chamber 1 in which vapor deposition is performed on the non-magnetic support 2
2 (lower side in FIG. 1) to prevent the vapor flow evaporated from the crucible 6 from diffusing into a region other than the region where vapor deposition is performed on the non-magnetic support 2. Has been done.

Therefore, using a vacuum vapor deposition apparatus having such a structure, the water-soluble latex containing acrylate as a main component has a density of 10 million pieces / mm as an undercoat layer.
Polyethylene terephthalate (PET) coated with ²
Co-Ni alloy was obliquely vapor-deposited in an oxygen atmosphere under the following conditions on a base film having a thickness of 10 μm and a width of 150 mm, and a single layer film of a ferromagnetic metal thin film having a film thickness of 200 nm was formed as a magnetic layer. Formed as.

<Conditions during vapor deposition> Incident angle of vapor flow θ: 45 to 90 ° Deposition source: Co ₉₀ Ni ₁₀ alloy (numerical values represent weight%) Feed rate of non-magnetic support: 25 m / min During deposition Degree of vacuum: 5-8 × 10 ^-2 Pa Oxygen gas introduction rate: 250 cc / min Next, a back coat layer made of a mixed system of carbon and urethane binder is applied on the side opposite to the magnetic layer forming surface of the base film. Was 0.6 μm.

Subsequently, a top coat layer was formed by coating with perfluoropolyether on the surface of the magnetic layer.

Further, the obtained wide base film is
A sample tape was produced by slitting the sample into a width of mm.

Example 2 In the continuous winding type vacuum vapor deposition apparatus used for forming the magnetic layer of the magnetic tape manufactured in Example 1, the shape of the ferromagnetic material 18 of the differential evacuation mechanism 19 was pelletized. The shape was changed (here, the diameter was 10 mm and the length was 12 mm), the other members were made to have the same configuration as in Example 1, and a sample tape was produced in the same manner as in Example 1 using this vacuum vapor deposition apparatus.

Here, when the ferromagnetic material 18 was supplied, since it was used in the form of pellets in advance,
It need not be shaped as described above. However, when a large gap is generated between the pellets or between the pellet and the ferromagnetic material introducing tube 20 during supply, the degree of vacuum in the vapor deposition chamber 12 is disturbed and the differential exhaust mechanism 19 causes a pressure difference. Since it becomes impossible to control, the pellets were aligned as much as possible at the time of supply so that the above gap was made small.

In the sample tapes produced in the respective examples as described above, and in the continuous winding type vacuum vapor deposition apparatus for comparison, the linear material having a diameter of 6 mm was used as the ferromagnetic material 18 of the differential evacuation mechanism 19. Of the
The crucible 8 is continuously extruded from the side of the crucible 8.
When the height of the molten metal surface of the crucible 8 is supplied so as to be constant (Comparative Example 1), a pellet-shaped product having a diameter of 10 mm and a length of 12 mm is intermittently provided at time intervals where the height of the molten metal surface of the crucible 8 is constant. In the case of being supplied in a specific manner (Comparative Example 2), the dropout and magnetic properties were evaluated.

As a test for confirming the difference in shape and supply method (form) of the ferromagnetic material 18, molten alloys of the same lot were processed into respective shapes. The impurity content of the alloy used at this time is as shown in Table 1 below.

[0060]

[Table 1]

For the dropout, a high band 8 mm video deck manufactured by Sony; a modified EV-S900 (trade name) was used, and the reproduction output level was 16 dB / 10.
Measurement was performed for 10 minutes with the output decrease of μ seconds or more as a dropout, and the number of dropouts per minute was obtained.
The results are shown in Table 2 below.

Further, Table 2 below also shows the processing cost depending on the shape of each ferromagnetic material 18 used in Examples 1 and 2 and Comparative Examples 1 and 2. In general, the ferromagnetic material 1
The cost of No. 8 increases as the number of processing processes increases and as the processed shape becomes smaller.

[0063]

[Table 2]

The magnetic characteristic is a sample vibration type magnetometer (VSM).
It was measured at. The results are shown in Table 3 below.

[0065]

[Table 3]

As shown in Tables 2 and 3, the present Example 1,
2, the product qualities such as dropout and magnetic properties are almost at the same level as in the case of using the conventional ferromagnetic material supply method (Comparative Examples 1 and 2). As a result, it was found that the ferromagnetic material was continuously supplied from the outside of the vacuum chamber without causing any actual damage.

Further, in Comparative Example 1, the shape of the above-mentioned ferromagnetic material was made into a relatively thin linear shape, but a considerable amount of length is required to cope with the vapor deposition for a long time. It is necessary to dispose a reel mechanism, a mechanism for straightening a curved linear alloy into a linear shape, and the like in the vacuum chamber, resulting in an increase in the size of the entire apparatus. For this reason, installation in existing equipment is not easy.

Similarly, in Comparative Example 2, when supplying the pellet-shaped ferromagnetic material, it is necessary to arrange a mechanism for aligning the pellets in the vacuum chamber, and in this case as well, the configuration of the entire apparatus becomes large. There is a drawback that.

On the other hand, in the first and second embodiments, since the mechanism for supplying the ferromagnetic material is arranged in the atmosphere outside the vacuum chamber, the differential evacuation mechanism is evacuated. Although it is externally attached to the side wall of the chamber, the structure of the vacuum chamber itself is simplified and the entire apparatus becomes compact.

Further, in Comparative Example 1, it is necessary to take out the wire-shaped ferromagnetic material remaining in the vacuum chamber once and supply a new wire into the vacuum chamber again, and the remaining wire is melted again. Newly used as a long wire material. This is not preferable because it leads to repeated machining of the alloy and raises the alloy cost.

Further, when the raw material alloy is supplied for each batch of vapor deposition as in Comparative Example 2, it is difficult to switch the raw material in the vacuum chamber and to replenish it thereafter, so that an extra raw material alloy is supplied in advance. However, there are many factors that increase the cost, such as a large proportion of the raw material supply system in the equipment volume and the need to enlarge the pump.

On the other hand, in the first and second embodiments, it is possible to attach the differential pumping mechanism to an existing manufacturing apparatus relatively easily, and the manufacturing cost is low even when newly manufactured. be able to.

[0073]

As is apparent from the above description, in the present invention, when a magnetic layer composed of a ferromagnetic metal thin film is formed on a non-magnetic support by a vacuum deposition method, the structure of the ferromagnetic metal thin film is formed. Since the ferromagnetic material used as the material is continuously supplied from the atmosphere, an inexpensive magnetic recording medium can be realized.

Further, the means for supplying the above-mentioned ferromagnetic material to the evaporation source used in the present invention has a relatively simple structure and can be made compact and does not occupy a space. Can be easily introduced.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a configuration example of a vacuum vapor deposition apparatus used when a magnetic tape is manufactured by applying the present invention.

FIG. 2 is a schematic diagram showing a configuration example of a differential evacuation mechanism for supplying a ferromagnetic material from the atmosphere to a vapor deposition source.

[Explanation of symbols]

 1 Vacuum Chamber 2 Non-Magnetic Support 3 Feed Roll 4 Winding Roll 5 Cooling Can 6, 7 Guide Roll 8 Crucible 9 Ferromagnetic Material 10 Electron Gun 11 Tape Feed / Wind Chamber 12 Vapor Deposition Chamber 13 Shutter 14 Oxygen Gas Inlet Port 15 Exhaust port 16 Partition plate 18 Ferromagnetic material 19 Differential evacuation mechanism 20 Ferromagnetic material introduction pipe 21 Ferromagnetic material supply means 22, 23, 24 Exhaust means

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location H01F 41/20 H01F 41/20

Claims (3)

[Claims] 1. A method of manufacturing a magnetic recording medium in which a ferromagnetic metal thin film is formed on a non-magnetic support by a vacuum thin film forming technique, the constituent material of the ferromagnetic metal thin film when the ferromagnetic metal thin film is formed. A method for producing a magnetic recording medium, characterized in that a metal or an alloy used as the above is continuously supplied from the atmosphere outside the vacuum chamber. 2. In a magnetic recording medium manufacturing apparatus for forming a ferromagnetic metal thin film on a non-magnetic support by a vacuum thin film forming technique, a metal or alloy used as a constituent material of the ferromagnetic metal thin film is removed from a vacuum chamber. An apparatus for manufacturing a magnetic recording medium, which has a mechanism for continuously supplying from the atmosphere. 3. The magnetic recording medium manufacturing apparatus according to claim 1, further comprising a differential pumping mechanism.