JPH0765373A - Device for producing magnetic recording medium - Google Patents

Abstract

PURPOSE:To prevent irregular vapor deposition and to form a smooth magnetic film by depositing sputtered magnetic material on a substrate to form the magnetic film and using a drum-like roll on which the substrate is guided. CONSTITUTION:After a vacuum chamber 6 is evacuated to 10<-4> to 10<-6>Torr vacuum, a magnetic metal 5 in a crucible 4 is molten and vaporized by resistance heating, induction heating, or electron beam heating method to form a thin film of the magnetic metal 5 to 0.04-1mum thickness on a substrate 3 such as a PET film in contact with and guided on a can roll 1. Thus, a metal thin film type magnetic recording medium is produced. By this method, such a problem that a smooth magnetic film is not obtd. when a cylindrical can roll is used can be avoided. No irregular deposition is caused, and the obtd. magnetic recording medium is excellent in recording and reproducing characteristics.

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 apparatus.

[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, it is well known that a magnetic recording medium having a magnetic layer formed by a dry plating means such as vacuum deposition, sputtering or ion plating has been proposed. Since the magnetic recording medium of this type has a high packing density of magnetic material, it is suitable for high-density recording.

An apparatus for producing a magnetic recording medium by such dry plating means is generally constructed as shown in FIG. In FIG. 3, 21 is a cooling can roll,
22a is a polyethylene terephthalate (PET) film 23 supply side roll, 22b is a PET film 23 winding side roll, 24 is a crucible, 25 is a magnetic metal, and 26 is a vacuum container. Then, after evacuating the inside of the vacuum container 26 to have a predetermined vacuum degree, the electron gun is operated to operate the crucible 24.
The magnetic recording medium is manufactured by evaporating the magnetic metal 25 in the inside and depositing (evaporating) evaporated particles of the magnetic metal 25 on the PET film 23.

However, it has been found that there is a problem such as deposition unevenness when forming a magnetic film using such a deposition apparatus.

[0005]

DISCLOSURE OF THE INVENTION While the research on the above problems has been earnestly promoted, it has become clear that the problem of vapor deposition unevenness lies in the PET film 23. That is, the PET film 23 guided by the can roll 21 is 1 to 5 kg.
/ A tension of about the width is applied to the roll 22a from the supply side 22a to the winding side 22b, but when it is attached to the can roll 21, the direction crossing the axial direction of the can roll 21 (PET film) I noticed that streaky wrinkles were formed along the longitudinal direction 23. Then, when the vaporized particles of the magnetic metal 25 fly and are deposited (deposited) on the place where the line-shaped wrinkles are formed, the wrinkles are formed so as to be transferred as they are, and uneven deposition occurs. It was speculated that it might be.

By the way, while pushing forward with further research on the cause of the wrinkles, it has come to be noticed that wrinkles are scarcely observed when magnetic metal particles are not vapor-deposited. As a result of further research based on such knowledge, wrinkles act on the PET film 23 in which heat from the deposited magnetic metal or radiant heat from the evaporation source is attached to the can roll 21. It came to the revelation that it might be the result.

Therefore, if it is assumed that heat causes wrinkles, it was thought that it would be better to eliminate the effect of this heat. For example, PET film 23
If the heat-dissipating efficiency is improved by further adhering to the can roll 21, it is considered that the PET film 23 in the central portion where the wrinkles are generated is further closely adhered to the can-roll 21 to improve the heat dissipation efficiency. It was Then, based on such an idea, the can roll 21 is configured in a drum shape, and magnetic metal is vapor-deposited on the support attached to the drum roll. The vapor deposition was not uneven.

The present invention has been achieved on the basis of such findings, and an object of the present invention is to provide a technique for forming a clean magnetic film. The purpose of this invention is
A magnetic recording medium manufacturing apparatus for forming a magnetic film by depositing flying magnetic material on a support, wherein a roll for guiding the support is formed in a drum shape. This is achieved by a medium manufacturing apparatus.

The roll is a can roll, and the can roll has a circumferential shape of 10 cm in length.
Drum shape having an inclination of about 1 to 2 mm, especially the radius r _{1 of the} center of the can roll is about 100 to 1000 m
m, the radius r _{2 at} a position 10 cm away from the center of the can roll is about 98 to 999 mm, and r ₁ -r ₂ is 1 to 2
The drum shape is preferably mm.

[0010]

1 and 2 show an embodiment of a magnetic recording medium manufacturing apparatus according to the present invention. FIG. 1 is a schematic view of the whole, and FIG. 2 is a perspective view of a main part (can roll). is there. In each figure, 1 is a cooling can roll, 2a is a supply side roll, and 2b.
Is a roll on the take-up side, and a polymer material such as polyester such as PET, polyamide, polyimide, polysulfone, polycarbonate, olefin resin such as polypropylene, cellulose resin, vinyl chloride resin,
Non-magnetic thickness 10 μm, width 20 made of inorganic material such as glass and ceramics, metal material such as aluminum alloy
A support body 3 of about 0 mm is fed from the supply-side roll 2a, wound around the can roll 1, and then wound around the winding-side roll 2b.

As can be seen from FIG. 2, the can roll 1 has a drum shape. Especially, the radius r at the center
₁ is about 100 to 1000 mm, for example 125 mm, radius r at a position 10 cm away from the center of the can roll
₂ is about 98-999 mm, for example 123.5 mm, r ₁
-R ₂ is configured to have a drum shape of 1.5 mm. That is, although the can roll 1 looks like a cylinder at first glance, it is designed to have a shape that bulges at the center like a drum when observed strictly. The length L of the can roll 1 in the axial direction is about 100 to 100.
The width of the support body 3 has a margin of about 1 mm or more, such as 0 mm.

An undercoat layer for improving the adhesion of the magnetic layer (magnetic thin film) is provided on the surface of the non-magnetic support 3. That is, by appropriately roughening the surface roughness, for example, the adhesion of the magnetic thin film formed by the oblique vapor deposition method is improved, and the surface roughness of the magnetic recording medium surface is moderated to improve the running property. Therefore, for example, Si
The thickness containing particles such as O ₂ is 0.005 to 0.1 μ
The undercoat layer is formed by providing the coating film of m.

Reference numeral 4 is a crucible, and in this crucible 4,
For example, in addition to metals such as Fe, Co and Ni, Co-Ni alloys, Co-Pt alloys, Co-Ni-Pt alloys, Fe-C
o alloy, Fe-Ni alloy, Fe-Co-Ni alloy, Fe
-Co-B alloy, Co-Ni-Fe-B alloy, Co-C
r alloy, or these are filled with magnetic metal 5 such as Al or Ta.

As a constituent material of the crucible 4, for example,
MgO, ZrO, BeO, Al₂O ₃, Si₃N_Four, B
N, ThO₂, CaO, SiO₂, B_FourCeramic such as C
Weaving like a cous or plain weave or a weave
Examples include ceramics with intervening carbon fibers.
It Among them, the preferred one is B_FourC crucible
Is a crucible made of ceramics with a carbon fiber interposed.
The inner wall of the crucible 4 in which the magnetic metal 5 is placed is a rear
Many sharp-angled recesses are formed like the Shiki coast
Of.

Reference numeral 6 is a vacuum container. In the apparatus configured as described above, the inside of the vacuum container 6 is 10 ⁻⁴ to 10 ⁻⁶ To.
After exhausting to a vacuum degree of about rr, the magnetic metal 5 in the crucible 4 is melted and evaporated by resistance heating, high frequency heating, electron beam heating, etc., and the PET film etc. attached to the can roll 1 is supported. 0.04 to 1μ for body 3
A metal thin film type magnetic recording medium is manufactured by vapor-depositing the magnetic metal 5 having a thickness of m. At the time of forming the magnetic thin film, it is preferable to supply oxygen to the vapor deposition portion and forcibly oxidize it to oxidize the surface layer portion of the magnetic thin film to form a protective layer of an oxide film. However, the thickness of the protective layer composed of this oxide film is about several tens of liters, and an oxide film of this thickness may be composed of natural oxidation. In some cases, no action is required.

Since the support 3 was attached to the drum-shaped can roll 1, wrinkles were not formed on the support 3 when the magnetic metal 5 was deposited. Therefore,
There is no problem that the magnetic film cannot be made clean as in the case of being attached to the conventional cylindrical can roll 1, that is, vapor deposition unevenness does not occur and the magnetic film is formed neatly and recording / reproducing characteristics are improved. An excellent magnetic recording medium can be obtained.

In this way, the take-up roll 2b, on which the support 3 having a magnetic thin film having no vapor deposition unevenness is wound, is taken out, and carbon black having an average particle size of 20 nm, vinyl chloride resin and urethane are taken out. A coating material for a backcoat in which a binder resin composed of a prepolymer is dispersed is applied by a direct gravure method on the surface of the support 3 opposite to the magnetic layer to form a backcoat layer having a dry thickness of 0.5 μm. Set up.

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). -Apply the dispersed coating material on the magnetic surface by a die coating method so that the thickness after drying is about 20Å, and dry at 70 ° C.

After that, a magnetic tape or the like is obtained by slitting into a predetermined width.

[0020]

According to the present invention, a magnetic film is formed neatly and a high performance magnetic recording medium can be obtained.

[Brief description of drawings]

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

FIG. 2 is a perspective view of essential parts of an embodiment of a magnetic recording medium manufacturing apparatus according to the present invention.

FIG. 3 is a schematic explanatory diagram of a conventional magnetic recording medium manufacturing apparatus.

[Explanation of symbols]

 1 Can roll 2a Supply side roll 2b Winding side roll 3 Support 5 Magnetic metal

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akira Shiga 2606 Akabane, Kai-cho, Haga-gun, Tochigi Prefecture Kao Co., Ltd.

Claims (3)

[Claims] 1. A manufacturing apparatus for a magnetic recording medium, which comprises a magnetic film by depositing flying magnetic material on a support, wherein a roll on which the support is guided is formed in a drum shape. An apparatus for producing a characteristic magnetic recording medium. 2. The roll is a can roll, and the peripheral shape of the can roll is 1 to 2 mm for a length of 10 cm.
The apparatus for manufacturing a magnetic recording medium according to claim 1, wherein the apparatus has a drum shape having a certain degree of inclination. 3. The roll is a can roll, and the radius r _{1 of the} center of the can roll is about 100 to 1000 mm,
The radius r _{2 at} a position 10 cm away from the center of the can roll is about 98 to 999 mm, and r ₁ -r ₂ is _{1 to 2} mm.
3. The apparatus for producing a magnetic recording medium according to claim 1, wherein the apparatus has a drum shape.