JPH0414618A - 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 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 Recent advances in recording technology have significantly improved the recording density not only per unit area but also per unit volume, and with the practical use of vapor-deposited tapes in which the magnetic recording layer is partially made of a ferromagnetic metal thin film, this will continue to develop. is expected.

FIG. 2 is an example of an enlarged sectional view of a conventional vapor deposition tape.

In Fig. 2, 1 is a polyethylene terephthalate film and 2 is a fine particle coating layer (Japanese Patent Laid-Open No. 59-207422,
3 is Co-Ni-
0 is an obliquely deposited layer, 4 is a fluorine-containing lubricant, and 5 is a back coat layer.

Although the highest recording density currently achieved is achieved with high band 8 mm video, the vaporized tapes described above are essential to obtaining satisfactory image quality.

Problems to be Solved by the Invention However, when a magnetic recording medium, such as the above-mentioned vapor-deposited tape, whose magnetic recording layer is a ferromagnetic metal thin film is made thinner for the purpose of further increasing the volumetric density, jitter components increase and the original high image quality cannot be achieved. There was a problem with deterioration, and improvements were desired. The present invention was made in view of the above circumstances,
The object of the present invention is to obtain a magnetic recording medium that can provide high image quality even on magnetic tape.

Means for Solving the Problems In order to solve the above-mentioned problems, the magnetic recording medium of the present invention has a ferromagnetic metal thin film on one side of a polymer film and a back coat layer on the other side. The mixing ratio of the lubricants used was different.

Effect The magnetic recording medium of the present invention has the above-described structure, and can maintain good lubrication during high-speed sliding with the magnetic head and low-speed sliding with traveling system members such as posts, and even when made thinner. This means that jitter components can be suppressed.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an enlarged sectional view of a magnetic recording medium according to an embodiment of the present invention. In FIG. 1, 1 is a polymer film such as polyethylene terephthalate, polyethylene naphthalate, polyphenylene sulfide, polyether ether ketone, aramid, polyimide, etc., and 2 is a fine particle used in the fine particle coating layer such as SiO2, Tio2. CaCO3
゜Carbore Fe 203. A i' 203.
It may be made of polyimide, polyethylene, etc. and may be mixed with a worm-like raised layer.

Incidentally, instead of the fine particle coating layer, protrusions formed by internal particles within the polymer film may be used. 3 is C0-0Co-Ni-
A ferromagnetic metal thin film consisting of an obliquely deposited film typified by 0, a perpendicular magnetization film typified by Co-Cr, etc. The ferromagnetic metal thin film itself has a multilayer structure, or it is disposed on a soft magnetic layer or underlayer. It may be something that has been done.

6 is a lubricant layer A, and 7 is a lubricant layer B. 6 is 5iOz
It may be arranged through a protective film such as a film, a plasma polymerized film, or a carbon film. It is a requirement of the present invention that both lubricants A and B are composed of a mixed layer of two or more types of lubricants, and that their mixing ratios are different. The lubricant that can be used may be either a specially synthesized lubricant or a naturally occurring lubricant. Lubricant A, which protects the ferromagnetic metal thin film, is mainly used at high speeds (3 m/sec to 10 m/5
lubricant B was selected with an emphasis on improving the lubrication with the post material etc. at low speeds in the range of (1cm/sec to 50an/sec). It is preferable to select by placing - For boat fishing, it is preferable that lubricant A has a larger mixing ratio of substances with polar groups such as carboxylic acids and fatty acids, and lubricant B
The opposite is better.

Of course, it is not possible to uniquely determine different mixing ratios depending on the material, roughness, etc. of the surface on which the lubricant is placed, and although there are different mixing ratios here, we selected them in descending order of mixing amount (A
, B total)) The difference between the two types of ratios is set at a range of 1.5 times to 4 times.

Examples of the present invention will now be described in more detail in comparison with comparative examples.

On a polyethylene terephthalate film with a thickness of 8 μm, a worm-like raised layer of water-soluble polymer with a height of 150 mm and containing 30 to 35 pieces/μ2 of SiO2 with a diameter of 180 mm is arranged,
On top of that, a Co-co-
Ni (Coi 80wt%) was deposited obliquely at a minimum incident angle of 41 degrees to form a 0.2 μm Co-Ni-0 film, on top of which an amorphous carbon film was deposited by high-frequency sputtering. On one side, a back coat layer made of polyester resin containing equal weights of carbon particles with a diameter of 0.07 μm and CaCO3 particles with a diameter of 0.08 μm was placed, and the T1 ion implantation conditions were further varied (10~
20KeV, 10μA/cd~60C1czA/al,
1 sec to 60 sec), the mixed lubricant coated on the amorphous carbon was controlled by varying the transfer ratio to the back coat layer side to obtain an 8 mm wide magnetic tape, and a commercially available 8 mm video tape (EV- 3900, manufactured by Sony ■) were randomly selected, and the jitter spectra between 20 and 1'00 Hz were compared. In the comparative example, a lubricant was transferred without Ti ion irradiation. The amount of lubricant was expressed as the total amount applied, and the mixing ratio was measured on the untraveled portion of the evaluation tape. The table shows the tape conditions and the amount of time-axis variation measured. Incidentally, the amount of time axis variation shown in Table 1 showed the maximum value.

(Margins below) As is clear from Table 1, the magnetic recording medium of the present invention has the following characteristics:
Shows good jitter. For both tapes, even when the 8 mm video was modified and the speed was increased to 3 times, the jitter was at most 0.35 (μ5ec) or less (in the case of the comparative example, the maximum was 29μ5ec), which was good.

Effects of the Invention As described above, the present invention has excellent effects such as being able to provide a thin, high-quality tape with less jitter components.

[Brief explanation of the drawing]

FIG. 1 is an enlarged cross-sectional view of a magnetic recording medium according to an embodiment of the present invention;
FIG. 2 is an enlarged sectional view of a conventional magnetic recording medium.

Claims (1)

[Claims] A magnetic recording medium comprising a ferromagnetic metal thin film on one side of a polymer film, a back coat layer on the other side, and different mixing ratios of lubricants on each surface.