JPH08194944A - Method and system for producing magnetic recording medium - Google Patents

Abstract

PURPOSE: To obtain a thin magnetic metal film having enhanced magnetic characteristics and excellent in durability by passing evaporated magnetic particles through a plasmatic space before the particles arrive at a support in the production of a magnetic recording medium. CONSTITUTION: The system for producing a magnetic recording medium comprises a cooling can roll 1, a roll 2a on the feeding side of a support 3, a roll 2b on the winding side of support 3, a crucible 4, a magnetic metal 5, a shielding plate 6, an oxygen gas supply nozzle 7, means 8 for irradiating microwave of 2.45 GHz at 800W, a magnet 9 for forming a plasmatic atmosphere, and a vacuum tank 10. An oblique evaporation unit A is provided with an ECR plasma unit B for generating a plasma of magnetic metal evaporation particles. The magnetic metal 5 being filled in the crucible 4 includes Fe, Co, Co-Ni alloy, etc. The tank 10 is evacuated to 10<-4> -10<-6> Torr and the magnetic metal Co-Ni (80-20) in the crucible 4 is evaporated. Subsequently, it is irradiated with microwave by the microwave irradiating means 8 to generate a plasma thus depositing the magnetic metal by 2000Å thick on the support 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for manufacturing a magnetic recording medium.

[0002]

BACKGROUND OF THE INVENTION In a magnetic recording medium such as a magnetic tape, due to a demand for high density recording, a binder resin is not used as a magnetic layer provided on a non-magnetic support, instead of a coating type using a binder resin. A metal thin film type that is not used has been proposed. That is, there has been proposed a magnetic recording medium having a magnetic layer formed by PVD means such as vacuum deposition, sputtering or ion plating. Since this type of magnetic recording medium has a high packing density of magnetic material,
It is suitable for high density recording.

This PVD means, for example, an apparatus for producing a magnetic recording medium by vapor deposition is generally constructed as shown in FIG. In FIG. 2, 31 is a cooling can roll, 32a is a polyethylene terephthalate (PET) film 33 supply side roll, and 32b is a PET film 3.
3 roll on the winding side, 34 a shielding plate, 35 a crucible, 36
Is a magnetic metal, and 37 is a vacuum chamber. And the vacuum chamber 37
After the inside is evacuated to a predetermined vacuum degree, the electron gun 38 is operated to evaporate (scatter) the magnetic metal 36 in the crucible 35, and evaporate particles of the magnetic metal 36 are deposited (evaporated) on the PET film 33. By doing so, a magnetic recording medium is manufactured.

Here, the vapor deposition method is taken up particularly because the formation speed of the magnetic film is high. That is, the vapor deposition method has a faster magnetic film formation rate than the sputtering method. However, when comparing the vapor-deposited magnetic film and the sputtered magnetic film, the vapor-deposited magnetic film has a low binding strength to the support. Moreover, magnetic characteristics such as saturation magnetic flux density are low. As described above, the conventional metal thin film type magnetic film is a two-way type that sacrifices deposition rate (productivity) or sacrifices magnetic characteristics. Was given.

[0005]

DISCLOSURE OF THE INVENTION As a result of intensive investigations in accordance with the above demands, if plasma energy is applied to evaporated magnetic particles,
When deposited on a support, it was deposited with the same characteristics as sputtered magnetic particles, and the revelation that the binding strength of the magnetic film would be high and the saturation magnetic flux density would also be improved was obtained.

The present invention has been achieved based on this finding, and a metal thin film type magnetic film can be efficiently formed, and the obtained magnetic film has high binding strength and excellent magnetic properties. Another object of the present invention is to provide a magnetic recording medium. An object of the present invention is a method for producing a magnetic recording medium in which a metal thin film type magnetic film is provided on a support by evaporating metal magnetic particles and depositing them on a support, This is achieved by a method of manufacturing a magnetic recording medium, characterized in that the vaporized metal magnetic particles are allowed to pass through a plasma space before reaching the support.

An apparatus for producing a magnetic recording medium having a metal thin film type magnetic film provided on a support by evaporating metal magnetic particles and depositing the magnetic particles on the support, which is an evaporation apparatus. And a plasma-generating means for converting the evaporated metal magnetic particles into plasma in the step of depositing the metal magnetic particles by the vapor deposition apparatus.

In particular, an apparatus for producing a magnetic recording medium in which a metal thin film type magnetic film is provided on a support by evaporating metal magnetic particles and depositing them on the support, Supply means, winding means for the support, traveling means for moving the support from the supply means to the winding means, a vacuum tank, and a cooling can provided in the vacuum tank for guiding the support. A roll, an evaporation source of the metal magnetic particles to which the metal magnetic particles deposited on the support guided by the cooling can roll are supplied, a heating means for evaporating the metal magnetic particles from the evaporation source of the metal magnetic particles, and And a plasma generating means for converting metal magnetic particles from an evaporation source into plasma.

The plasma generating means may be an apparatus comprising a magnetic field applying means and a microwave irradiating means, for example, an ECR plasma device. Hereinafter, the present invention will be described with reference to specific examples.

[0010]

1 is a schematic view of an apparatus for manufacturing a magnetic recording medium according to the present invention. In the figure, 1 is a cooling can roll, 2
a is a supply side roll of the support 3, 2b is a roll on the support 3 side, 4 is a crucible, 5 is a magnetic metal, 6 is a shield plate, 7 is an oxygen gas supply nozzle, 8 is an output of 800 W, and 2. 45G
Hz microwave irradiation means, 9 is a magnet for forming a plasma atmosphere, and 10 is a vacuum chamber. Although the entire structure is new, the partial structure is well known, and thus detailed description thereof will be omitted. The important point is that the ECR is applied to the oblique deposition equipment A.
The point is that a plasma device B is added to convert the evaporated metal magnetic particles into plasma.

The support 3 may be magnetic or non-magnetic. However, a non-magnetic material is generally used. For example, polyester such as PET, polyamide, polyimide, polysulfone, polycarbonate,
An olefin resin such as polypropylene, a cellulose resin, a polymer material such as a vinyl chloride resin, an inorganic material such as glass and ceramics, and a metal material such as an aluminum alloy are used. An undercoat layer for improving the adhesion of the magnetic layer (magnetic thin film) is provided on the surface of the support 1 as needed.

The magnetic metal 5 to be filled in the crucible 4 is, for example, a metal such as Fe, Co or Ni, and Co--N.
i alloy, Co-Pt alloy, Co-Ni-Pt alloy, Fe
-Co alloy, Fe-Ni alloy, Fe-Co-Ni alloy,
Fe-Co-B alloy, Co-Ni-Fe-B alloy, Co
-Cr alloys, alloys containing these metals such as Al, or the like.

In the apparatus constructed as described above, the inside of the vacuum chamber 10 is about 10 ⁻⁴ to 10 ⁻⁶ Torr, for example, 2 ×.
After evacuation to a vacuum degree of 10 ⁻⁵ Torr, the magnetic metal (Co—Ni (80-2
0)) 5 is evaporated. The evaporated magnetic metal particles are magnets 9
Fly through the magnetic field formed by. At this time, the microwave from the microwave irradiation means 8 is applied. As a result, plasma is generated, and the vaporized particles are converted into those having high energy characteristics equivalent to the sputtered particles. And
For example, when reaching the support 1 traveling at 5 m / min,
The magnetic metal 5 having a thickness of 04 to 2 μm, for example 2000 Å, is deposited to manufacture a metal thin film type magnetic recording medium.

When forming this magnetic thin film, O ₂ gas is supplied from the nozzle 7 at a rate of 180 sccm,
The surface layer portion of the magnetic thin film deposited on the support 1 is forcedly oxidized. In this way, the magnetic thin film is formed and wound on the winding side roll 2b, and then the winding side roll 2b is taken out and is composed of carbon black having an average particle diameter of 20 nm, vinyl chloride resin and urethane prepolymer. A back coat coating material in which a binder resin is dispersed is applied by a direct gravure method to the surface of the support 1 opposite to the magnetic film to form a back coat layer having a dry thickness of 0.5 μm.

Fluorine perfluoropolyether (grade: FOMBLIN ZDIAC carboxyl group modified, manufactured by Nippon Montedison Co., Ltd.) was diluted to 0.1% in a fluorine inert liquid (Fluorinert, FC-84, manufactured by Sumitomo 3M Limited). The dispersed coating material was applied to the magnetic surface by a die coating method so that the thickness after drying was about 20Å, dried at 70 ° C., and slit into a width of 8 mm.

When the magnetic characteristics of the thus obtained 8 mm magnetic tape for VTR were examined, the coercive force Hc was 920 O.
e, the saturation magnetic flux density Bs was 5800G. Moreover, when the output after the 1-hour repeated running test is examined, it is 0.6d.
B was falling. On the other hand, in the apparatus shown in FIG. 1, the oblique vapor deposition apparatus A from which the ECR plasma apparatus B including the microwave irradiation means 8 and the magnet 9 is removed is similarly used,
An 8 mm VTR magnetic tape for comparison was obtained.

When the magnetic characteristics of this comparative magnetic tape were examined, the coercive force Hc was 920 Oe, but the saturation magnetic flux density Bs was 4900 G, and the output after a 1-hour repeated running test showed a decrease of 1.7 dB. Was. Therefore, according to the present invention, a metal thin film type magnetic film having improved magnetic characteristics and excellent durability is formed.

Moreover, since this magnetic film is formed by the vapor deposition method, the film forming efficiency is high. That is, when the magnetic film is formed, it has the features of both the vapor deposition method and the sputtering method.

[0019]

[Effect] A metal thin film type magnetic film having improved magnetic characteristics and excellent durability can be formed with high productivity.

[Brief description of drawings]

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

FIG. 2 is a schematic diagram of a conventional magnetic recording medium manufacturing apparatus.

[Explanation of symbols]

 A Diagonal evaporation equipment B ECR plasma equipment

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

Claims (4)

[Claims] 1. A method of producing a magnetic recording medium having a metal thin film type magnetic film provided on a support by evaporating metal magnetic particles and depositing the metal magnetic particles on the support, the method comprising: A method of manufacturing a magnetic recording medium, characterized in that metal magnetic particles are passed through a plasma-converted space before reaching a support. 2. An apparatus for producing a magnetic recording medium having a metal thin film type magnetic film provided on a support by evaporating metal magnetic particles and depositing the metal magnetic particles on the support. An apparatus for producing a magnetic recording medium, comprising: and a plasma-generating means for converting vaporized metal magnetic particles into plasma in the step of depositing metal magnetic particles by the vapor deposition apparatus. 3. An apparatus for producing a magnetic recording medium having a metal thin film type magnetic film provided on a support by evaporating metal magnetic particles and depositing the metal magnetic particles on the support, the support comprising: Supply means, winding means for the support, and traveling means for causing the support means to travel from the supply means to the winding means,
A vacuum tank, a cooling can roll provided in the vacuum tank for guiding the support, and an evaporation source of the metal magnetic particles to which the metal magnetic particles deposited on the support guided by the cooling can roll are supplied. An apparatus for producing a magnetic recording medium, comprising: heating means for evaporating the metal magnetic particles from the evaporation source of the metal magnetic particles; and plasma generation means for converting the metal magnetic particles from the evaporation source into plasma. 4. The apparatus for manufacturing a magnetic recording medium according to claim 2, wherein the plasma generating means includes a magnetic field applying means and a microwave irradiating means.