JPH07244851A - Method and apparatus for manufacture of magnetic recording medium - Google Patents

Abstract

PURPOSE:To obtain a high performance magnetic recording medium which has excellent magnetic characteristics and corrosion-resistance by a method wherein specific ion neutralized atoms are applied to magnetic metal deposited on a supporter. CONSTITUTION:A supporter 1 is paid off from a pay-off side roll 2a and taken up by a take-up side roll 2b through a cooling can roll 3. Magnetic metal Fe 6 in a crucible 5 is evaporated by the operation of an electron gun 7 and deposited on the supporter l. When the magnetic metal Fe is deposited, ions N<+> are emitted from the ion gun of an ion gas apparatus 10 and electrons from an electron emission source are made to collide with the ions N<+> to neutralize them and excited atoms N* in a valence electron exciting state are emitted to the deposited Fe film. By this application, N* and Fe react with each other and an FexN ferromagnetic film is formed on the supporter 1 surface. With this constitution, a magnetic recording medium which is composed of the magnetic film having excellent corrosion-resistance and which has excellent magnetic characteristics can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for manufacturing a metal thin film type 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. It is well known that 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 a wet plating means such as electroless plating, or a dry plating means such as vacuum deposition, sputtering or ion plating. Since the magnetic recording medium of this type has a high packing density of magnetic material, it is suitable for high-density recording. By the way, as a magnetic material forming a magnetic layer in a metal thin film type magnetic recording medium of this type, a magnetic metal such as a Co—Cr alloy or a Co—Ni alloy is used. However, since Co is a rare substance, there are problems of cost and environmental pollution.

On the other hand, in view of the fact that Fe does not have the above-mentioned problems, Fe has begun to attract attention as a magnetic material for a metal thin film type magnetic recording medium. That is, although Fe and Ni can be considered as the non-Co-based metallic magnetic material, it is said that Fe is preferable in view of the magnitude of saturation magnetization. By the way, since Fe is more likely to rust than Co, it is necessary to be chemically stable. From such a point of view, it is proposed that the magnetic film is made of Fe _x N (Japanese Patent Laid-Open Nos. 60-236113 and 63-2372).
No. 19). A magnetic recording medium having a magnetic film made of these Fe-based metal compounds is said to have good magnetic characteristics, excellent corrosion resistance, and excellent high-density recording.

As means for forming the magnetic film of these Fe-based metal compounds, means by ion assist using an ion gun has been proposed. That is, in the process of depositing Fe on the support by the oblique vapor deposition method, a means has been proposed in which nitrogen ions are bombarded toward the deposited metal film by an ion gun. However, such a conventional ion assist method is not satisfactory.

[0006]

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a magnetic recording medium having excellent magnetic characteristics. The purpose of this invention is
A step of evaporating a magnetic metal and depositing the evaporated particles on a non-magnetic support; a step of neutralizing ions that react with the magnetic metal to improve magnetic properties; and And a step of irradiating the magnetic recording medium.

Further, a container containing the magnetic metal, an evaporation means for evaporating the magnetic metal in the container, and a non-magnetic support for accumulating evaporated particles evaporated by the evaporation means,
The present invention is achieved by an apparatus for manufacturing a magnetic recording medium, comprising: an ion gun arranged toward the deposited film, and a neutralization processing means for neutralizing ions emitted from the ion gun.

In the above invention, there is a method of neutralizing the ion by applying an electron to neutralize the ion, that is, a method of performing neutralization treatment by electron irradiation means can be adopted.
Examples of the magnetic metal used as the evaporation source material in the present invention include Fe and Fe having a purity of 99.95% or more.
-Co alloy, Fe-Ni alloy, Fe-Pt alloy (however,
When adopting a means such as binary vapor deposition, it is sufficient to put Fe and an alloying element such as Ni in each crucible, and it is not always necessary to use an alloy). An Fe-based metal containing this as a main component is a preferred example.

Further, it reacts with a magnetic metal to improve magnetic characteristics.
The ions to be generated are, for example, nitrogen gas (N ₂), With nitrogen and hydrogen
Mixed gas (N₂+ H₂), A mixture of ammonia and hydrogen
Gas (NH₃+ H₂), A mixed gas of nitrogen and oxygen (N₂
+ O₂) Etc. are supplied to the ion gun and released from this
Ions can be used. And such a
If the on-flow is irradiated with an electron flow from the side, the ions
Is neutralized, the magnetic metal in the direction of the ion flow is
If the deposited film is left, the neutralized one is the magnetic metal.
The deposited film is irradiated and the magnetic properties are excellent.
For example Fe_xThe N film can be efficiently obtained.

The present invention will be described in more detail below. FIG. 1 is a schematic view of an apparatus in which the method for manufacturing a magnetic recording medium of the present invention is implemented. In the figure, 1 is a non-magnetic support, and this support 1 is polyester such as polyethylene terephthalate (PET), polyamide, polyimide, polysulfone, polycarbonate, olefin resin such as polypropylene, cellulose resin, Polymer materials such as vinyl chloride resins, inorganic materials such as glass and ceramics, and metal materials such as aluminum alloys are used.

An undercoat layer for improving the adhesion to the magnetic film is provided on the surface of the support 1. That is, in order to improve the adhesion of the magnetic film formed by dry plating by appropriately roughening the surface roughness and further improve the runnability by making the surface roughness of the magnetic recording medium surface moderate, for example, The undercoat layer is formed by providing a coating film containing particles such as SiO ₂ and having a thickness of 0.01 to 0.5 μm.

Reference numeral 2a is a supply side roll, 2b is a winding side roll, and the support 1 is configured to run between them. 3 is a cooling can roll, 4 is a shielding plate, 5 is a crucible, 6 is Fe with a purity of 99.95% or more, 7 is an electron gun,
Reference numeral 8 is a vacuum container, 9 is an oxygen gas supply nozzle for irradiating oxygen along the film deposited on the support 1 guided by the cooling can roll 3, and 10 is an ion gun device provided with electron irradiation means.

This ion gun device 10 is constructed as shown in FIG. 2, and an electron emission device is provided on the front side of a normal ion gun. That is, the ion accelerating electrode 12 is emitted from the ion gun 11.
Electrons emitted from the electron emission source 13 arranged on the side of the ion flow accelerated by the electron flow and accelerated by the electron acceleration electrode 14 (for neutralizing the ions and causing valence electron excitation). By applying electrons, the ions are neutralized and become in a state of excited valence electrons, which are made to collide with the film deposited on the support 1.

Then, the inside of the vacuum container 8 is evacuated to a predetermined vacuum degree, the support 1 is run, and in this state, the electron gun 7
Then, Fe in the crucible 5 is melted and evaporated, and deposited on the support 1. In this state, ions (for example, N ⁺ ) are being emitted from the ion gun 11, and the N
^{The +} ions are neutralized by the collision of the electrons from the electron emission source 13 and become in the state of valence electron excitation. This excited N ^* is irradiated toward the Fe vapor deposition film, and this excited N ^* reacts with Fe. Then, the Fe _x N ferromagnetic film is formed on the surface of the support 1.

Further, at this time, if oxygen is irradiated from the oxygen gas supply nozzle 9 toward the vapor deposition (deposition) film, surface oxidation will be performed. In this way, the Fe-based compound ferromagnetic film is formed. An interesting point of the present invention is that an Fe-based compound ferromagnetic film having a high coercive force Hc and a large saturation magnetic flux density Bs was obtained as compared with the case where the film was formed using a simple ion gun. That is, it is possible to obtain a magnetic material having more excellent magnetic characteristics. Moreover, this Fe-based compound ferromagnetic film was also excellent in corrosion resistance. Furthermore, the film forming rate was also high.

[0016]

【Example】

Example 1 A PET film 1 having a thickness of 10 μm was mounted on an oblique vapor deposition apparatus as shown in FIG. 1, and the PET film 1 was run at a running speed of 5 m / min. The purity of 99.9 contained in the magnesium oxide crucible 5
9% Fe was evaporated by operating the electron gun 7 of 15 kW, and Fe was deposited and deposited on the PET film 1. still,
At this time, the inside of the vacuum container 8 was 2 × 10 ⁻⁵ Torr.

During the Fe deposition, N ⁺ is emitted from the ion gun 11 toward the PET film 1, and this N ⁺ is released.
Electrons from the electron emission source 13 were made to collide with to neutralize the valence electrons so that the valence electrons were excited, and the excited N ^* was irradiated toward the Fe vapor deposition film. In this way, carbon black having an average particle size of 20 nm is dispersed in a binder resin of urethane prepolymer and vinyl chloride resin on the back surface side of the PET film 1 having the Fe _x N ferromagnetic film formed on the front surface in a thickness of 1500 Å. The back coat paint thus obtained was applied by a direct gravure method so that the dry thickness was 0.5 μm, and dried.

After this, perfluoropolyether (FO
MBLIN Z DIAC Carboxyl group-modified, manufactured by Nippon Montedison Co., Ltd.) is diluted and dispersed in a fluorine-inert liquid (Fluorinert, FC-77, Sumitomo 3M Co., Ltd.) to a concentration of 0.1% and dried by a die coating method. It is applied to the surface of the metal magnetic film so that the thickness afterwards is about 20 Å, dried at 105 ° C, and slit into a predetermined width,
I got a magnetic tape.

[Example 2] In Example 1, oxygen was blown from the oxygen gas supply nozzle 9 toward the vapor deposition film during film formation. [Embodiment 3] The same procedure as in Embodiment 1 is performed except that a mixed gas of ammonia and hydrogen (NH ₃ : H ₂ = 3: 1) is supplied instead of supplying the nitrogen gas to the ion gun 11. Got

[Example 4] In Example 1, the purity was 9
A magnetic tape was obtained in the same manner except that an Fe-Ni alloy was used instead of 9.99% Fe. [Comparative Example 1] A magnetic tape was obtained in the same manner as in Example 1, except that the N ⁺ from the ion gun 11 was not bombarded with electrons and the N ⁺ as it was was irradiated toward the Fe vapor deposition film.

[Characteristics] The magnetic characteristics of the magnetic tapes obtained in each of the above examples were examined. The results are shown in the table below.
Shown in 1. Table-1 Coercive force (Oe) Saturated magnetic flux density (G) Corrosion resistance ΔBs (%) Example 1 2100 6300 3 Example 2 2500 4700 6 Example 3 2300 6000 3 Example 4 1700 4000 2 Comparative Example 1 1800 5000 5000 5 * corrosion resistance according to this rate of decrease of the saturation magnetic flux density Bs when soaked 1 week in a 5% saline solution, high performance magnetism who than illuminating the N ⁺ irradiated with N ^* and excellent magnetic properties It can be seen that a recording medium can be obtained.

Further, it can be seen that the obtained magnetic film is also excellent in corrosion resistance.

[0023]

According to the present invention, a high performance magnetic recording medium having excellent magnetic characteristics and corrosion resistance can be obtained.

[Brief description of drawings]

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

FIG. 2 is a schematic view of a main part of a magnetic recording medium manufacturing apparatus of the present invention.

[Explanation of symbols]

 1 Support 2a Supply Side Roll 2b Winding Side Roll 3 Cooling Can Roll 4 Shielding Plate 5 Crucible 6 Fe 7 Electron Gun with Purity of 99.95% or More 8 Vacuum Container 9 Oxygen Gas Supply Nozzle 10 Ion Gun Device 11 Ion Gun 12 Ion Acceleration Electrode 13 Electron emission source 14 Electron acceleration electrode

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Shigemi Wakabayashi Inventor Shigemi Wakabayashi 2606 Akabane, Kaiga-cho, Haga-gun, Tochigi Kao Co., Ltd.Institute of Information Science (72) Inventor Akira Shiga 2606 Akabane, Kaiga-cho, Haga-gun, Tochigi Kao Company Information Science Laboratory

Claims (4)

[Claims] 1. A step of evaporating a magnetic metal and depositing the evaporated particles on a non-magnetic support, and a step of neutralizing ions that react with the magnetic metal to improve magnetic properties.
And a step of irradiating the neutralized one. 2. The magnetic recording according to claim 1, wherein the step of neutralizing the ions that react with the magnetic metal to improve the magnetic properties is performed by applying electrons to the ions to neutralize the ions. Medium manufacturing method. 3. A container containing a magnetic metal, an evaporation means for evaporating the magnetic metal in the container, a non-magnetic support for accumulating evaporated particles evaporated by the evaporation means, and a container for the deposited film. An apparatus for manufacturing a magnetic recording medium, comprising: an installed ion gun; and a neutralization processing means for neutralizing ions emitted from the ion gun. 4. The apparatus for producing a magnetic recording medium according to claim 3, wherein the neutralization processing means is an electron irradiation means.