JPS60224124A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To obtain the titled recording medium having excellent rust resistance, etc. by vapor-depositing a magnetic metallic material on the surface of a moving substrate in the form of a bent inclined column while changing the incident angle continuously from a high to a low incident angle, and vapor-depositing a nonmagnetic material on said vapor-deposited film while changing the incident angle continuously from a high to a low incident angle. CONSTITUTION:A metal such as Fe, Co, Ni, or an alloy of said metals is vapor-deposited from a crucible 23 on a nonmagnetic strip-shaped substrate 21 of polyester, etc. to form an inclined columnar magnetic layer 2 on the substrate 1(21) while transporting the substrate 21 along a cooling can 22 in the direction as shown by the arrow A, changing the incident angle continuously from a high incident angle such as 90 deg. to a low incident angle of 25 deg., and controlling the vapor flow with deposition preventive plates 27 and 28. Then >=1 kind of nonmagnetic metallic material selected from Cr, Ti, Sn, Cu, and Al from a crucible 25 is vapor-deposited on the layer 2 to form a film 3 while reversely winding and transporting the substrate 21 in the direction as shown by the arrow B and again transporting the substrate in the direction as shown by the arrow A, and changing the vapor flow continuously from a high to a low incident angle with deposition preventive plates 28 and 29. The magnetic recording medium having excellent rust resistance and less curls is obtained in this way.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a magnetic recording medium comprising a ferromagnetic metal thin film formed by oblique incidence deposition as a magnetic recording layer on a non-magnetic support. The present invention relates to a metal thin film magnetic recording medium that has excellent properties and less curl.

[Prior art]

Conventionally, as a magnetic recording medium, r-
1-Fe2O3*Fe doped with Fe2071*Co
3O4* Co-doped Fea04* r-Fea
Bertolide compound of rs and Fe3O4 * Magnetic powder such as CrO2 or ferromagnetic alloy powder is mixed with a powdered magnetic material in an organic binder such as vinyl chloride-vinyl acetate copolymer, styrene-butadiene copolymer, epoxy resin, polyurethane resin, etc. Paint-on type products have been widely used, in which a dispersed material is applied and dried. In recent years, with the increasing demand for high-density recording, the magnetic recording layer is a ferromagnetic metal thin film formed by paper deposition methods such as vacuum evaporation, sputtering, and ion blating, or plating methods such as electroplating and electroless plating. . So-called binder-free magnetic recording media that do not use a binder are attracting attention, and various efforts are being made to put them into practical use.

Conventional coating-type magnetic recording media mainly use ferromagnetic metals or metal oxides with low saturation magnetization as magnetic materials, and the thinner layers required for high-density recording result in a reduction in signal output. It has reached its limits, and its manufacturing process is complicated, and it has the drawback of requiring large auxiliary equipment for solvent recovery and pollution prevention. In a non-binder type magnetic recording medium, a ferromagnetic metal having a surface saturation magnetization larger than that of the above oxide is formed as a thin film without containing a non-magnetic substance such as a binder.

It has the advantage that it can be made ultra-thin for high-density recording, and the manufacturing process is greatly simplified.

As one of the conditions required for magnetic recording media for high-density recording, high coercive force and thinner layers have been proposed both theoretically and experimentally. There are great expectations for non-binder type magnetic recording media that can easily be made thinner by an order of magnitude and have a high saturation magnetic flux density.

The method using K vacuum evaporation does not require drainage treatment 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 Kadoya ratio desirable for magnetic recording media by vacuum deposition is disclosed in U.S. Patent No. 33μ2t.
The oblique incidence vapor deposition method described in No. 3 Co., No. 334'JAjJ, etc. is known.

Furthermore, major problems concerning magnetic recording media made of ferromagnetic metal thin films include strength against corrosion and abrasion, and running stability. During the process of recording, reproducing, and erasing magnetic signals, the magnetic recording medium is subjected to high-speed relative motion with the magnetic head, but at this time, the movement must be smooth and stable, and at the same time, contact with the head must be maintained. There shall be no wear or damage due to It is also required that recorded signals should not be reduced or lost due to changes over time due to corrosion or the like while the magnetic recording medium is being stored. Providing a protective layer is being considered as a method of improving durability and weather resistance.

As a method of improving the characteristics of a metal thin film type magnetic recording medium by providing a protective layer, for example, providing an organic layer is disclosed in U.S. Pat. No. 12,4417, same da.

/j2. No. 14/-7, No. 3, 02≠, rit
It is known from U.S. Pat. sit, tt.

It is known from No. 001, same≠9.2ψg.

In order to further improve durability and weather resistance, a method was proposed in which Cr was vapor-deposited on the surface of a ferromagnetic metal thin film in a moderate vacuum to form a layer of a mixture of Cr and Cr oxide (Special Publication No. 393). ) or a method of providing a laminated protective layer of a Cr layer and Si and Si oxide layers (Japanese Patent Publication No. 11-471, 1
No. 1) is known. However, the rust resistance of conventional protective films was not sufficient, and further improvements were required for practical use.

Furthermore, when a ferromagnetic metal thin film is formed on a flexible support by oblique incidence deposition, curling occurs in the ferromagnetic metal thin film to make it concave due to the internal stress of the metal thin film.
Even if a protective film such as r is provided, the above problems are not solved.

[Purpose of the invention]

An object of the present invention is to provide a protective layer with excellent rust resistance.

Another object of the present invention is to provide a metal thin film type magnetic recording medium that also exhibits small curl.

[Structure of the invention]

The present invention provides a magnetic recording medium in which a vapor flow of a magnetic metal material evaporated from an evaporation source is deposited on a moving substrate, in which the incident angle of the vapor flow of a magnetic metal material with respect to the moving substrate is set to a high incident angle. By continuously changing the incident angle from low to low,
The present invention relates to a magnetic recording medium characterized by being provided with a non-magnetic metal vapor deposited film formed by continuously changing the incident angle of a vapor flow of a non-magnetic metal material to the moving base from a high incident angle to a low incident angle. Furthermore, Cr s T as a non-magnetic metal material
The present invention relates to the above magnetic recording medium, characterized in that it uses at least one selected from the group consisting of ih Sn s Cu h All.

In the present invention, the oblique incidence vapor deposition method is a method in which a vapor flow of a film-forming metal material is made incident at a certain incident angle θ relative to the normal line of the substrate surface to deposit a vapor-deposited thin film on the substrate surface. In the present invention, when forming a magnetic thin film by oblique incidence deposition, oblique incidence deposition is started at an incident angle θmax, and as the substrate moves, the deposition of the magnetic thin film is stopped at an incident angle θmin. It is. On the thus formed magnetic thin film, a non-magnetic metal material, especially Crs Tts Sns, is applied to the magnetic thin film formed in this manner by continuously decreasing the incident angle θ starting from the incident angle θmax' and changing it to the incident angle θmin'.
At least one selected non-magnetic metal material is formed as a protective film.

In the present invention, the incident angle θ is preferably from j'C to Oo, particularly θmax' is from j00 to Oo,
0m1ns 0m i n' is j j 0-71 o
O FIG. 1 shows a magnetic recording medium according to the present invention. 9. A magnetic metal vapor deposited film is provided on the support. Furthermore, a non-magnetic metal vapor deposited film 3 is formed thereon. When creating the magnetic metal vapor deposited film λ, the angle of incidence on the surface of the support 1 is changed from θmax to 0m i while transporting the support 1 with the arrow AK.
A magnetic film having a curved inclined columnar structure can be obtained by continuously changing the value to n. The thickness of the magnetic metal vapor deposited film is preferably from about 0.02 am to j −'l' 7 FL s because it needs to be thick enough to provide sufficient output as a magnetic recording medium and thin enough to perform high-density recording. From 09038m, it is 0ti1rL. In forming the non-magnetic metal vapor deposited film 3, the incident angle of the vapor flow on the surface of the support 1 is changed from θmax' to θm while the support 1 is being conveyed.
Cr so as to change continuously to in'.

At least one nonmagnetic metal material selected from Ti, Sn%Cu%l is formed as a deposited film. The thickness of the non-magnetic metal vapor deposited film 3 is set to approximately 0 depending on the conditions such as obtaining a sufficient protective effect and ensuring that the gap between the magnetic metal vapor deposit film 2 surface and the magnetic head does not decrease the output due to -sing loss. .001~o, ibTIL11 preferably 0,0
The range is 03' NO, 02b@.

The magnetic metal material used in the present invention is *Fe*(-
metal such as as N J, or Fe-Co, Fe-N
ib Co-N is F e-Co-N i, F
e -Rh duty Fe c,,, Co Cub Co A
u*Co -Yh Co-L as Co-P r%
Co-Gd5Co-8m5 Co-P ts Ni-
Cu, Mn-B1°Mn-8blMn-AA! b F
e-Cr* Co-Crb N1-cr, Fe-Co
-Cr5 N1-Co-cr, Fe-co-Ni-Cr
It is a ferromagnetic alloy such as Particularly preferred is CO or an alloy containing 70% by weight or more of CO. The magnetic metal vapor deposition film is formed in an atmosphere containing a reactive gas such as oxygen.

Vapor deposition in the present invention refers to the above-mentioned U.S. Patent No. 33≠, 2A
In addition to the usual vacuum evaporation described in the specifications of J. No. 2, vapor flow is ionized and accelerated by electric fields, magnetic fields, electron beam irradiation, etc. to create an atmosphere with a large mean free path of evaporated molecules. The method also includes a method of forming a thin film on a supporting substrate by using
Field vapor deposition method as shown in the specification of No. R, Tokko Shosan 3-//j Koj No., Tokko Shoda T-10 Sanj No., Tokko Sho≠7-2tj7ri No., Tokko Sho Ionized vapor deposition methods such as those disclosed in Japanese Patent Application Laid-open No. 4tJuJf, Japanese Patent Application Laid-Open No. 3312O, Japanese Patent Application Laid-Open No. 3143, and Japanese Patent Application Laid-Open No. J3J can also be used in the present invention.

Preferred substrates for use in the present invention are plastic bases such as polyethylene terephthalate, polyimide, polyamide, polyvinyl chloride, cellulose triacetate, polycamenate, and polyethylene naphthalate.

In the magnetic recording medium of the present invention, a lubricant layer or a so-called back layer may be provided on the back surface of the support, if necessary.

Further, a layer made of an organic or inorganic substance may be provided between the magnetic metal vapor deposited film and the support.

〔Example〕

The present invention will be specifically explained below using Examples.

It goes without saying that the present invention is not limited to these.

Example 1 Using a winding υ type vapor deposition apparatus whose main parts are shown in Figure 1,
A magnetic tape was prepared by forming a dicobalt-deposited magnetic thin film on a polyethylene terephthalate film having a thickness of /J, jttgl by an oblique incidence deposition method. In FIG. 2, the strip-shaped support is conveyed along the Fi cooling can 22, and a magnetic deposited film and a nonmagnetic deposited film are formed on the surface thereof by oblique incidence deposition method. The vapor deposition materials 23% λμ were each placed in a crucible 21. It is charged and heated and evaporated by a suitable heating means. The angle of incidence of the vapor flow onto the support 1 is controlled by the deposition prevention plates λ7, 2 and λ. In this example, while transporting the polyethylene terephthalate film in the direction of arrow A, Co is evaporated from 6ss until the incident angle θmax and Oc%θmin! ! 0
A magnetic evaporated film was formed.

The setting of θmax is done using the adhesion prevention plate 27. The setting of θmin is performed using the adhesion prevention plate 21. Next, the polyethylene terephthalate film is conveyed along the direction of arrow B and rewound, and then conveyed again along the direction of arrow A and placed in the crucible λ.
! Cr or Ti.

Alternatively, Sn was evaporated to form a nonmagnetic deposited film. θmax' set by the anti-adhesion plate core, 21r
, 0min are each ri o 0. ao was set to 0.

The thickness of the magnetic deposited film was 1oooh, and the thickness of the nonmagnetic deposited film was 1 JoA.

Comparative Example 1 A cobalt-deposited magnetic thin film was formed on a polyethylene terephthalate film in the same manner as in Example 1, and then Cr or Ti was deposited by a conventional vacuum deposition method.

Alternatively, Sn was formed to have the same thickness as in Example 1. In other words, in Fig. 2, the anti-adhesive plate r was removed and the lug installed directly under the cooling can 2 was removed.
Cr or Ti,
Alternatively, a vapor deposited film of Sn was formed respectively.

The rust resistance and curl of the magnetic tape thus obtained were measured. Rust resistance was tested using a Hatsuroya weather tester (Model E-/dWG manufactured by Yamazaki Seiki Research Institute) based on J-grade evaluation of rust occurrence after storage for 2q hours. Regarding the curl, the curl value -t-Sγ was calculated, where γ is the radius of curvature of the curl in the width direction of the magnetic tape. The measurement results are shown in Table 7 below.

Table 1 * Grade rating:! Best Embodiment 2 Using the winding type vapor deposition apparatus shown in Fig. 2, a magnetically vapor-deposited thin film of CoN1 (NiJ, weight ratio) was deposited on a polyethylene terephthalate film having a thickness of JLTTIL to a thickness of /300 by an oblique incidence vapor deposition method. It was formed to become. While transporting the polyethylene terephthalate film in the direction of arrow A, the incident angle omax in an atmosphere containing 02 gas is set to rj',
Magnetic deposited films were formed with θmin set to lOo. Next, while transporting the polyethylene terephthalate film in the direction of arrow B, the non-magnetic material was evaporated from the lupus to form it on the magnetic deposited film to a thickness of 200 Å. Cr*Cu%A7 was used as the non-magnetic material, and the incident angle θmax' and 0min' beam 00 were set for the anti-adhesion plate and it respectively.
It was set as % to 0.

Comparative Example 2 After forming a CoN1 (vapor-deposited magnetic thin film on a polyethylene terephthalate film) in the same manner as in Example 2, Comparative Example 1
Similarly, Crs or Cu,
Alternatively, A/ was formed to have a thickness of 2OOA.

The rust resistance and curl of the magnetic tape thus obtained were measured in the same manner as in Example 1 and Comparative Example 1, and the results were as shown in Table 2.

Table 1 [Effects of the Invention] As described above, the magnetic recording medium according to the present invention is a metal thin film type magnetic recording medium that has excellent rust resistance and less curling, and has great practical advantages as a single type magnetic recording medium.

[Brief explanation of the drawing]

FIG. 1 shows an example of the structure of a magnetic recording medium according to the present invention. C. Support, 2. Magnetic metal vapor deposited film. 3...Nonmagnetic metal vapor deposited film. Figure 1 shows a schematic diagram of an apparatus for manufacturing the magnetic recording medium of the present invention. , 2/... band-shaped support, 22... cooling can 1.23, 2μ... vapor deposition material. 21.26.30... Crucible. -27, -2F, 25' - Anti-adhesive plate patent applicant Fuji Photo Film Co., Ltd.

Claims (1)

[Claims] 1) A magnetic recording medium in which a vapor flow of a metal material evaporated from an evaporation source is deposited on a moving substrate,
By continuously changing the incident angle of the vapor flow of the magnetic metal material on the moving substrate from a high incident angle to a low incident angle, the moving substrate is moved onto a magnetic metal vapor deposited film having a curved nine-inclined columnar structure. 1. A magnetic recording medium comprising a non-magnetic metal vapor deposited film formed by continuously changing the incident angle of a vapor flow of a non-magnetic metal material onto a substrate from a high incident angle to a low incident angle. 2) Cr*T1*Sn as non-magnetic metal material
The magnetic recording medium according to claim 1, characterized in that at least one selected from *Cu%A is used.