JPS5841443A - Manufacture of magnetic recording medium - Google Patents

Abstract

PURPOSE:To improve the reproduction output characteristics and adhesive strength by moving a substrate so that the incident angle of a flow of vapor of a magnetic metallic material is continuously changed from a large incident angle to a small incident angle and by introducing an oxidizing gas into the small incident angle part. CONSTITUTION:A flow of vapor of a ferromagnetic body is diagonally vacuum- deposited on a support 2 transferred along a cylindrical cooling can 1 in the direction of an arrow 3 from an evaporating source 4 through a mask 5 so that the incident angle is continuously changed from a large incident angle thetamax to a small incident angle thetamin, and a gas introducing pipe 6 is installed at the small incident angle part to introduce an oxidizing gas such as gaseous oxygen.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a magnetic recording medium by forming an engineered magnetic thin film by vacuum deposition on a flexible substrate such as a moving polymer molded article.

Conventional magnetic recording media include K r on a non-magnetic support.
F+! 2 U s e Co f dope r
Fe x 03゜Fe a () 4s Cor
Dope Shiri F @ z 04 e r F e fA
Bertolide compound with U s and k e 30 <, Cr
Powdered magnetic materials such as oxide magnetic powder such as Oz or ferromagnetic alloy powder are dispersed in an organic binder such as vinyl chloride-vinyl acetate copolymer, styrene-butadiene copolymer, epoxy resin, polyurethane resin, etc. Coat-on type products, in which a material is coated and dried, have been widely used.

In recent years, as the demand for high-density recording has increased, the strength of forming KL has increased, and plating methods such as vacuum evaporation, sputtering, ion plating, etc., 41-deposition methods, and electroplating, electroless plating, etc. BACKGROUND ART So-called binder-free magnetic recording media, which do not use a binder and have a magnetic metal thin film as a magnetic recording layer, are attracting attention, and various efforts are being made to put them into practical use.

Conventional coating-type magnetic recording media mainly use ferromagnetic metal
D Because metal oxides with low saturation magnetization are used as magnetic materials, the thinning required for high-density recording leads to a decrease in signal output, which is reaching its limit, and the production process is also complicated. -, it has the disadvantage of requiring large auxiliary equipment for recovering the starting material or preventing separation. In non-binder type magnetic F recording media, the oxide material is formed as a thin film without containing a non-magnetic material such as a strong sulfur material having a large saturation magnetization. It has the advantage of being able to be made into an ultra-thin shape, and the manufacturing process is simple.

High coercive force and thinness have been proposed both theoretically and experimentally as one of the requirements for magnetic recording media for high-density recording, and coating-type magnetic recording media have also reached an order of magnitude. There are great expectations for non-binder type magnetic recording media that can be easily made small and thin and have a high saturation magnetic flux density.

The vacuum deposition method has great advantages because it does not require a wastewater treatment process as in the case of plating, the manufacturing process is simple, and the deposition rate of the film can be increased. A method for manufacturing a magnetic film having coercive force and squareness desirable for magnetic recording media by vacuum deposition is disclosed in U.S. Pat. No. 7,424.
The oblique vapor deposition method described in No. 3, J3≠2633, etc. is known. According to this method, the larger the angle of incidence of the vapor flow incident on the substrate, the higher the coercive force of the medium can be obtained. However, there is a problem in that the deposition efficiency decreases when the incident angle is large.

As a method of forming a magnetic thin film with high coercive force at a relatively low angle of incidence, a method has been proposed in which a bulk acid is introduced into a vacuum chamber during oblique deposition, but the conventional method does not have sufficient reproducibility. , it had the disadvantage 1- of high noise.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method by which a magnetic recording medium having excellent S gas characteristics and low noise can be produced with good reproducibility using an oblique vapor deposition method.

That is, the present invention provides a method for producing a magnetic recording medium in which a vapor flow of evaporated magnetic metal material from an evaporation source L9 is obliquely deposited on a moving substrate, in which the incident angle (#) of the vapor flow with respect to the moving substrate is high. The base is moved so that the angle of incidence (Fma +
This is a method for producing an octane recording medium characterized by forming a strong thin film while introducing an oxidizing gas near the point where the steam flows.

Figures 1 and 1B schematically illustrate a method for manufacturing a magnetic recording medium according to the present invention. A tape-shaped support λ is moved in the direction of arrow J by a cylindrical cooling can l [4] arranged in a vacuum container 81 (only seven parts are shown). An evaporation source charged with magnetic material is installed below the cylindrical cooling can, making it a mask! ? Oblique incidence deposition can be carried out on the support λ which moves along the cooling can L through the support λ. As the tape-shaped support 2 moves, a high incident angle θma is maintained at the start of deposition of the magnetic thin film on the tape-shaped support λ.
Oblique deposition starts at x, and as the support 462 moves, the incident angle # decreases continuously, and the mask! Deposition of the magnetic thin film onto the support λ is stopped at a low incident angle θm1n) (determined by A gas introduction pipe 4 is arranged, and the S injection thin film is deposited while introducing an oxidizing gas from outside the vacuum chamber through the gas introduction passage 7. In the example of Figure 1 and B, the gas introduction pipe 6 is connected to the mask J. The oxidizing agent δ is supplied to the vapor flow of the magnetic material from the small hole t attached to the tip of the inlet pipe.

In the present invention, the incident angle is generally JO@~20@
It is desirable that the incident angle #max be 40'to'' and that the incident angle θmin be JO@~71'.

The magnetic metal materials used in the present invention include Fe, Co
, metals such as Ni, or Fe-Co.

Fe-Ni, Co-Ni, Fe-Co-N
i, re-Rh.

re-Cu, Co-Cu, Co-human u, Co-Y, Co
-La.

Co-Pr, Co-Gd, Co-8m, Co
-8i, Co-Pt.

NmuCu, Mn-B1, Mn-8b, Mn-At,
Fe-Ct.

Co-Cr, N1-Cr, Fe-Co-Cr
, Ni-Co-Cr.

These are ferromagnetic alloys such as Fe-Co, N1-Cr, and Fe-8i. % is preferably Co or C
It is an alloy containing more than 70g of oT7r. The thickness of the magnetic thin film is generally about 0.0λμrnP to about 2.0μm, since it needs to be thick enough to provide sufficient output as a magnetic recording medium and thin enough to perform high-density recording.
Preferably 0.0! Brn7yh et al. λ, oprt1.

Vapor deposition in the present invention refers to the above-mentioned U.S. Pat. No. 334'u4
In addition to the normal vacuum evaporation described in the specification of No.
It also includes a method of forming a thin film on a support in an atmosphere with a large mean free path of vaporized molecules by ionizing or accelerating a vapor flow using an electric field, magnetic field or electron beam irradiation, for example. Published by Japanese Patent Publication No. Shoj/-74'
The electric field evaporation method shown in the specification of No. 2001, Tokuko Sho≠j-//! λ! No., Tokuko Sho≠6--〇≠t4L No., Tokuko Sho 17-2417P, Tokuko Sho≠Tar≠Jhiro 32
No., Tokukai Sho≠2-JJ! No. 90, Tokukai Sho≠? -3u4L
Ionization vapor deposition methods such as those disclosed in Publication No. I3, % Open/Close 4CF-444231 may also be used in the present invention.

The tape-shaped support used in the present invention is a plastic base such as polyethylene terephthalate, polyimide, polyamide, polyvinyl chloride, cellulose triacetate, polycarbonate, polyethylene naphthalate, At, At alloy, Ti, Ti alloy, A metal strip such as stainless steel is used.

It is best to use oxygen as the oxidizing gas, and oxygen can be used alone or mixed with other gases.The amount of oxidizing gas introduced depends on the vacuum chamber volume, pumping speed, layout inside the vacuum chamber, and magnetic material. It cannot be limited because it varies greatly depending on the evaporation rate, the moving speed of the tape-shaped substrate, the width of the tape-shaped substrate, the type of magnetic material, etc.

Generally, there is oxygen in the formed magnetic thin film! ~JJat
It is preferable to introduce the gas so that the concentration of the gas is 1.0 m%.

EXAMPLES Next, the present invention will be specifically explained with reference to Examples, but the present invention is not limited thereto.

Example L: Oblique vapor deposition method Kx? on a polyethylene terephthalate film with a thickness of -23 μm using a winding type vapor deposition apparatus shown in Fig. 1 and its main parts. ) Copal) 7 was deposited to produce a magnetic tape. An electron beam heating type evaporation source was used as the evaporation source, and the evaporation source was introduced from the gas introduction tube 6 near the polyethylene terephthalide film moving along the oxygen gas t-can and near the vapor flow at a low incidence angle, while being operated at various degrees of vacuum. Cobalt was evaporated. Thickness of magnetic film 62/j 0
The angle of incidence during vapor deposition is set at θm.
axk201'1 0m1f14'ko It was set to 0.

Furthermore, for comparison, a magnetic tape was produced using a conventional reel type vapor deposition apparatus as shown in FIG. In FIG. 2, a cylindrical cooling can is placed in a vacuum container 82 (only seven parts are shown).
is moved in the direction of arrow II. An evaporation source 741C is placed below the cylindrical cooling can. Oblique-incidence deposition is carried out on the support via. The oxidizing gas is introduced through a gas introduction hole provided on the wall of the vacuum vessel S2. When preparing a comparative sample using the conventional method, the conditions except for the method of introducing oxygen gas, i.e., 23 μm polyethylene terephthalate film, copal) material IPr, 11 emission source, magnetic film thickness, and incident angle settings were as follows. The electromagnetic conversion characteristics of the obtained magnetic tape were measured using a VH8 type VT. Magnetic properties of magnetic tape when changing oxygen gas introduction pressure, 4! JM when recording MHz signal
The modulation noise level in Hz is shown in Table 1.

Table 7 The magnetic tape obtained by evaporating cobalt while introducing an oxidizing gas near a substrate and near a low-incidence vapor flow according to the present invention has a magnetic property that is different from that of a magnetic tape obtained by the conventional method of introducing an oxidizing gas. It can be seen that the quality is excellent and the noise is low.

Example 2 Similarly to Example 1, Co-N1 (Ni-2
Weight%) Alloy kli! A magnetic tape was produced by evaporation under the introduction of accumulated gas.

The thickness of the magnetic layer is set to JoooA, and the incident angle during vapor deposition is set as θmaXQrj', θmi nkjjo
And so. A comparative sample was prepared by using the winding type vapor deposition apparatus shown in FIG. 2 in the same manner as the comparative sample in Example IK, and by introducing oxygen gas using the conventional method. Magnetic properties of magnetic tape when oxygen gas introduction pressure is reduced, jMHz
Table 1 shows the noise level at $MHz when the signal tone was recorded. Variable noise is the average value of samples made 5 times, and the degree of noise variation in 3 times is li%.
It is shown in Table λ.

Table 2 shows that the magnetic tape according to the present invention has excellent characteristics compared to conventional magnetic tapes, has low noise, and can be manufactured with high reproducibility.

In the examples, only the case where the hexagonal thin film is multilayered is shown, but it is also possible to laminate the a-thickness thin film according to the method of the present invention, and the magnetic layer formed by further lamination may be 1ccr between
, Si, At, Mn, Bl, Ti.

Is Sn, Pb, In, Zn, Cu alloy a non-containing layer of these oxides, nitrides, etc.? It is also possible to intervene.

Furthermore, a base layer may be provided between the amorphous thin film and the substrate, or an organic or inorganic retention layer may be provided on the a-containing thin film. If the purpose is L, is there a back layer on the substrate surface on the opposite side from the magnetic thin film? It is also possible to provide one.

[Brief explanation of the drawing]

Figure 1 and B schematically show an apparatus based on the method of manufacturing a magnetic recording medium according to the present invention, and Figure 2 shows an apparatus according to a conventional method. Diagrammatically shown. / is a cylindrical cooling can, -2 is a support, ≠ is an evaporation source, !
is a mask, and 6 is an oxidizing gas introduction tube. Applicant: Fuji Photo Film Co., Ltd. Figure 1 A Figure 1 B 啜〒子〉4 Figure 2 Procedural Amendment 1939 Tapfz7 (3 Patent Office Commissioner Haruki Shimada 1, Indication of Case 1948 Patent Application No. 13?3 Co. No. 2, Title of the invention Method for manufacturing magnetic brass media 3 Relationship with the case of the person making the amendment Patent applicant 4, Subject of the amendment ``Detailed description of the invention'' column of the specification & Amendment Contents - L Book Ilf! 4 Specification Page 1! Between line 11 and @/λ line [, ``Also, in the example below, 9 shows an example in which a small hole is provided as a gas inlet, This may be changed to a slit-like shape, etc.," is inserted.

Claims (1)

[Claims] (1) In a method for producing a magnetic recording medium in which a vapor flow of a magnetic metal material evaporated from an evaporation source is obliquely deposited onto a moving substrate, the incident angle (θ) of the vapor flow with respect to the moving substrate is a high incident angle. (θWaX) to low incident angle (0m1n
), and forming a ferromagnetic thin film while introducing an oxidizing gas in the vicinity of the substrate and near the low-incidence (0 m1n) vapor flow.
A method for producing a magnetic recording medium having characteristics III.