JPH01176311A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To improve CN in a short wavelength region by laminating a 1st thin ferromagnetic metallic film and 2nd thin ferromagnetic metallic film via a flat org. projection layer extending in the transverse direction of a tape on a high-polymer film. CONSTITUTION:The 1st thin ferromagnetic metallic film 2 consisting of Co-Ni, Co-Ni-O, etc., the flat org. projection layer 3 extending in the transverse direction of the tape and the 2nd thin ferromagnetic metallic film 4 are laminated on the high-polymer film consisting of polyethylene terephthalate, etc., and a protective lubricating agent layer 5 is provided thereon.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic recording medium whose magnetic recording layer is a ferromagnetic metal thin film suitable for high-density magnetic recording.

Conventional technology Coating-type magnetic layers, which have been widely used as magnetic recording layers, are useful in magnetic recording, where wavelengths will become shorter and shorter in the future.
It becomes difficult to secure sufficient C/N. Daitte,
The practical application of magnetic recording media with magnetic recording layers made of ferromagnetic metal thin films such as Go-Ni-0 and Go-Or is expected [
IEEE TRANSACTIONS ON MAGNETICS
N MAGNETIC3) VO, [, MAG-21,
See No-3, P, P, 1217-1220 (1985).

In order to put such a magnetic recording medium into practical use, it is necessary to ensure durability and compatibility with high-speed sliding with alloy-based magnetic heads.
Proposals regarding this point are increasing [for example, Japanese Patent Application Laid-open No. 53-88704, Japanese Patent Application Publication No. 69-121631, Japanese Patent Application Publication No. 69-171026, Japanese Patent Application Laid-open No. 62-1979.
See Publication No. 17, etc.].

Among these methods, a method of forming fine irregularities on the magnetic recording layer is one step ahead of practical application [IEEE Transactions on Magnetics (IEEE T
RANSACTIONS ON MAGNETIC5)
vol, MAe-21, No-rs, P, P
, 1524-1528 (1985)].

Problems to be Solved by the Invention However, when #2051Sin is used on a polymer film,
2. Magnetic recording in which a ferromagnetic metal thin film is deposited by electron beam evaporation, sputtering, etc. on a fine particle coating layer coated and fixed with CaO, polymer latex, etc., and a protective lubricant layer is further deposited on top of it. The recording wavelength of the medium is 0.6 μm ~
When the wavelength was shortened to 0.3 μm, the C/N ratio was insufficient and improvement was desired.

The present invention was made in view of the above-mentioned circumstances, and it is an object of the present invention to provide a magnetic recording medium with good C/H in a short wavelength region.

Means for Solving the Problems In order to solve the above problems, the magnetic recording medium of the present invention has a first ferromagnetic metal thin film on a smooth polymer film, and a flat organic material extending in the width direction of the tape. a protrusion layer and a second
ferromagnetic metal thin films are laminated.

Function: Due to the above-described configuration of the magnetic recording medium of the present invention, the substrate on which the ferromagnetic metal thin film is formed does not undergo sudden changes in shape, thereby improving microscopic uniformity. On the other hand, since the ferromagnetic metal thin film is magnetically separated by the organic protrusion layer, the magnetic domain becomes smaller, noise is reduced, and C/N is improved. - On the other hand, durability is ensured because the flat organic protrusions extending in the width direction act equivalently to the granular protrusions when moving relative to the head.

EXAMPLE Hereinafter, an example of the present invention will be described in detail with reference to the drawings. Figure 0 is an enlarged sectional view of a magnetic recording medium according to an example of the present invention, and in the figure, 1 is polyethylene terephthalate, polyethylene naphthalate. , polyphenylene sulfide, polyether sulfone, polyimide, etc. 2 is Co, Go-Ni,
Go-Fe, Co-0r, Go-Pt, Co
-Rh, Co-Ru, Go-0, Co-Ta, Co-3
i.

Co-3m, Co-Cr-Nb, Co
A first ferromagnetic metal thin film made of -Ni-0, etc., with a thickness of 3, formed by electron beam evaporation, high frequency sputtering, etc.
00 to 1800 in-plane magnetization film or perpendicular magnetization film.

3 is a flat organic protrusion extending in the width direction of the tape, introduces monomer gas, forms plasma, squeezes the tip of the reaction tube, and irradiates the tape obliquely from the tip in the width direction of the tape onto the first ferromagnetic metal thin film. What is necessary is just to form the organic matter protrusion obtained by polymerization into a flat shape.

A second ferromagnetic metal thin film 4 may be made of the same material as the first ferromagnetic metal thin film, may be made of a different material, or may be a combination of a perpendicular magnetization film and an in-plane magnetization film.

5 is a protective lubricant layer, which is composed of a combination of a protective film such as a plasma polymerized film, an amorphous carbon film, a TiC film, a MoS2 film, or a SiO□ film, and a lubricant such as fatty acid or fluorine oil, and the film thickness is determined by the spacing loss. It is necessary to optimize materials and manufacturing methods that can be made as thin as possible to reduce the amount of damage.

Examples of the present invention will be described in more detail below in comparison with comparative examples. Polyethylene terephthalate film with a thickness of 10 μm covers the surface of 30 people with an average ffl of 0.0
1 (Torr) of Ar, 5ooV, glow discharge treatment for 1.6 seconds by one person, and Cio-N by electron beam evaporation method.
i (Go: 80 wt%) is placed in a cylindrical can with a diameter of 1 m, and the minimum incident angle is 36 degrees and the oxygen partial pressure is 3X 10
(Torr) and placed a first ferromagnetic metal thin film on top of the first ferromagnetic metal thin film.Hexamethylsilazane was introduced as a monomer gas into a reaction tube with an opening of 4oCIn x 2C1n. ), 9oO(W)
A plasma was generated and made incident on the thin film at an incident angle of 72 degrees, the height was 100 degrees, and the area of the protrusion was about 0.4 (μm).

A flat protrusion layer with a density of 2×10 cells/all was formed.

Furthermore, two types of second ferromagnetic metal thin films, a Go-Cr perpendicular magnetization film and a Co-Ni-0 obliquely deposited film, were disposed.

Example A is Go-Cr (Co: sowt%)'
i Target 71 - 500 perpendicularly magnetized films were formed by high frequency sputtering. Example B uses the same Go-Ni f as the first ferromagnetic metal thin film, and the minimum incident angle is 50
Electron beam evaporation was performed at an oxygen partial pressure of 2×1 O−5 (Torr) to form a Co-Ni-0 film of 80 OA.

Ar + H2 = 0 with graphite as the target, respectively.
．． 01 (Torr) Ar:)12=1:2
, 13.66 (MHz) 1.1 (KW) tD
Nine diamond-shaped hard carbon thin films were formed by high frequency sputtering, and 40 perfluorostearic acid films were formed by vacuum evaporation, and then processed into an 8 mm wide magnetic tape. On the other hand, in the comparative example, Ku
205 15 particles/(μm) 2 arranged, Example A
.

A first ferromagnetic metal thin film and a second ferromagnetic metal thin film were formed under the same conditions as B, and a protective lubricant layer was provided to prepare a comparative individual and a comparative example B as magnetic tapes each having a width of 8 mm.

Each magnetic tape has a pit length of 0.5 mm using a composite ring head that is a modified 8 mm video tape with a gap length of o and an amorphous alloy sputtered film of 13 μm placed near the gap.
Recording and reproduction was performed at 22 μm, and the C/N was compared. The band was 10 (MHz), and the comparative example was Ato (dB).

Comparative example B is +1.5 (dB), Example A is +2.2
(dB), and Example B was good at +4.0 (dB).

In addition, the methyl durability is increased by 3 (d) from the initial output in the methyl state.
B) When comparing the time until the output decreased, the experimenter was 31 to 38 (minutes), and Example B was 52 to 66 minutes).
The comparison number was 32-41 (minutes), and the comparative example B was 54-60 (minutes).
It is understood that even if the C/N ratio is improved by 1 minute), the durability is still at a sufficiently practical level.

Effects of the Invention As described above, according to the present invention, excellent C/N at short wavelengths can be achieved.
A magnetic recording medium can be obtained which provides excellent effects.

[Brief explanation of the drawing]

The figure is an enlarged sectional view of a magnetic recording medium according to an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Polymer film, 2... First ferromagnetic metal thin film, 3... Organic material protrusion layer, 4...
...Second ferromagnetic metal thin film.

Claims (1)

[Claims] A first ferromagnetic metal thin film on a smooth polymer film,
A magnetic recording medium characterized in that a flat organic protrusion layer extending in the width direction of the tape and a second ferromagnetic metal thin film are laminated.