JPS6220130A - magnetic recording medium - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a magnetic recording medium for perpendicular magnetic recording that can be used for high-density magnetic recording.

Conventional technology In recent years, there has been remarkable progress in increasing the density of magnetic recording, and perpendicular magnetic recording, a new recording method that replaces the longitudinal recording currently in use, has been proposed and is being actively developed. For example, see the magazine "Nikkei Electronics, January 19, 1981 issue, pages 114 to 126." This system uses a magnetic recording medium with a magnetic recording layer made of a new vertically magnetizable ferromagnetic thin film. Necessary 0 Perpendicular magnetic recording was realized using a Co-Cr sputtered film disclosed in Japanese Patent Publication No. 17282/1982.
As shown in FIG. 2, this is a method in which a perpendicularly magnetized film 2 made of a Co--Cr film is directly sputter-deposited on a non-magnetic substrate 1 such as a polymer substrate, and the recording and reproducing sensitivity was not at a satisfactory level.

Thereafter, when the media configuration shown in FIG. 3 was proposed, it became possible to put it to practical use in terms of recording performance, and vigorous development efforts began in various fields.

In FIG. 3, 3 is a polymer substrate, 4 is a soft magnetic layer typified by Ni--Fe, and 5 is a perpendicular magnetization film typified by Co--Cr. A medium with such a structure is disclosed in Japanese Patent Publication No. 58-91.
As disclosed in the above publication, since a magnetic head with a special structure is required, improvements in the magnetic head are being made in various fields.

Problems to be Solved by the Invention However, with the magnetic recording medium of the above configuration, it is not possible to obtain sufficient reproduction output with the ring-type magnetic head with the currently established technology. There is a problem that a standard head-tape interface cannot be found.

The present invention has been made in view of the above-mentioned problems, and uses a ring-type magnetic head to surpass longitudinal recording. The present invention provides a magnetic recording medium for perpendicular magnetic recording that can obtain a reproduction signal-to-noise ratio (Sc) at a high recording density.

Means for Solving the Problems In order to solve the above problems, the magnetic recording medium of the present invention comprises:
A metal black layer is placed on a polymer film, and a perpendicular magnetization film formed by electron beam evaporation is placed on top of the metal black layer.

Effects The present invention has the above-described configuration, (1) Since the metal black layer is in the form of fine particles, the friction in sliding contact with the magnetic head is reduced, the sliding contact becomes smooth, and stable spacing is maintained. Therefore, the reproduction S is good, and (2) C
o When a perpendicular magnetization film such as o-Cr is formed by electron beam evaporation, a large amount of radiant heat is generated, but the metal black layer absorbs this heat, so the temperature of the metal black layer is raised in the early stage of forming the perpendicular magnetization film. , to improve crystal orientation,
The resulting perpendicularly magnetized film has good orientation, and even a ring-type magnetic head can obtain excellent reproduction S/N.

EXAMPLES Below, the magnetic recording medium of the present invention will be explained with reference to the drawings.

FIG. 1 shows an enlarged sectional view of a magnetic recording medium according to an embodiment of the present invention.

In FIG. 1, 6 is a polymer film made of polyethylene naphthalate film with a thickness of 9 μm, and the average surface roughness is 30.

7 is a vacuum winding evaporation machine, while winding the Ar5
10 Torr, 021. xlo Torr
(7) A metal black layer obtained by evaporating and depositing A7 using induction heating in a vacuum atmosphere, with an average thickness of 360 mm and an average roughness of 170 mm.

Before forming this layer, the polymer film 6 had Ar0.09
Torr, 1200V, IAIO-discharge treatment.

8 is a perpendicularly magnetized film obtained by binary evaporation of Co-Cr by electron beam evaporation, with a thickness of 0.19 mm and Cr of 20.6 wt.
%, and the vertical coercive force is 820 (Oe).

In addition, the deposition rate during electron beam evaporation was 4.26μmμ
The incident angle was chosen to be close to the vertical component within 13 degrees, and the surface temperature of the cylindrical can with a diameter of 5oCrn was set to 96 degrees.

Reference numeral 9 denotes a protective lubricating film, which is a perfluorodecanoic acid film having a thickness of 60 mm formed by vacuum deposition.

Also, for comparison, Co-Cr (Cr; 20.6wt
A sputtered film of 0.19 μm in thickness (perpendicular coercive force 840 (
Oe)) Medium A and 0.03μ of Ge on the film/lz
m vacuum evaporated, and a vertical coercive force of 830 (Oe
) perpendicularly magnetized Co-Cr-Nb sputtered film.
A medium B having a thickness of 2 μm was prepared.

Note that the same protective film as in the example of the present invention was applied.

The characteristics between these media are as follows: gap length Q, 13 μm Co
A comparison was made by recording and reproducing using a -Z r-B amorphous ring type magnetic head. In this case, the current shortest practical recording wavelength for longitudinal recording is 0.75 μm, and the rack pitch is 1.
0 μm, the comparison was made using a recording wavelength at which the same output can be obtained by normalizing the reproduction output in a recording area of 76 μm×10 μm based on the head conditions. When the track pinch was fixed at 1Q/1m and compared, the example of the present invention had a diameter of 0.3 μm, and the comparative medium A had a diameter of 0.92 μm.
Comparative medium B had a thickness of 0.79 μm.

As described above, the magnetic recording medium of the present invention can significantly exceed the short wavelength recording and reproducing characteristics of longitudinal recording and conventional perpendicular recording.

Furthermore, in a comparison of perpendicular recording media, the time required for the playback output to decrease by sdB from the initial value when monitoring the playback output in a still state at 26°C and 80%RH was 136 minutes for the product of the present invention;
The durability of Comparative Examples A and B was 21 minutes and 32 minutes, respectively, and the product of the present invention also has excellent durability in a still state.

In addition, the product of the present invention has stable head touch and can be used 360 times with almost no change in S/H, whereas Comparative Examples A and B can be used 12 and 19 times. When used above, there is a drawback that the noise increases by 8 dB from adB.

In the examples of the present invention, the polymer film 6 was made of polyethylene naphthalate, but it may also be made of polyethylene terephthalate, cellulose triacetate, polyphenylene sulfide, or polycarbonate.

It may also be made of polyimide, polyamide, etc.

Further, in the embodiment of the present invention, the metal black layer 7 was made of an aluminum metal blank, but Au, Co,
It may also be Ni, Sn, Pb, Zz, Bi, Go, etc. In addition, although the perpendicular magnetization film 8 is made of Co-Cr, other materials include Co-Ti, Co-W, Co-Mo, Co-
Ru.

Co-0, Co-Cr-Ru, Co-Cr-Nb, etc. may also be used.

Furthermore, the protective lubricating film 9 also contains fatty acids, fatty acid esters,
Fatty acid amides, fluorine compounds, etc. may also be used.

Effects of the Invention As described above, according to the present invention, it is possible to stably extend excellent reproduction S by making slight improvements to the existing media-to-layer interface technology, which is important for the practical application of high-density magnetic recording. It is possible to obtain excellent effects that can be obtained over time.

[Brief explanation of the drawing]

FIG. 1 is an enlarged sectional view of a magnetic recording medium according to an embodiment of the present invention, and FIGS. 2 and 3 are enlarged sectional views of a conventional magnetic recording medium for perpendicular recording. 6...Polymer film, 7...Metal black layer, 8...Perpendicular magnetization film. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 6...+! 7 Bamboo film 7... Methanol reflex 8... Weight 1

Claims (1)

[Claims] A magnetic recording medium characterized in that a metal black layer is disposed on a polymer film, and a perpendicular magnetization film formed by electron beam evaporation is disposed on the metal black layer.