JPH01166325A - 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 magnetic recording technology have led to remarkable improvements in recording density, and it is strongly desired to put into practical use thin-film magnetic recording media such as vapor-deposited tapes that use a smooth ferromagnetic metal thin film for the magnetic recording layer. It is rare. However, when a vapor-deposited tape is directly exposed to the high-speed sliding motion of a magnetic head, various problems related to tribology occur, so proposals for improvements regarding the protective lubricant layer have rapidly increased [for example, Journal of the Television Society of Japan, vol. 40, /16,472 (1986)) o 2nd
As shown in the enlarged cross-sectional view of a conventional thin-film magnetic recording medium, such a medium consists of a thin film of ferromagnetic metal such as Co-Mi-0 or Go-Cr on a polymer film 1 such as polyester. A magnetic recording layer 2 is disposed, and a protective lubricant layer 3 is provided thereon.
A configuration with .

In particular, the protective lubricant layer is subject to limitations due to spacing loss, which is a problem during short wavelength recording, and many proposals have been made regarding materials and manufacturing conditions.

Vapor-deposited film of fatty acid metal salt (JP-A-54-113303), sputtered film of polymer having imide group (JP-A-54-113303)
7-116771) Diamond-like hard carbon film (
Japanese Society of Applied Magnetics, 46th Research Meeting Materials), fluorocarbon-based lubricating layer provided on adsorption layer of fatty acid metal salt (Japanese Patent Application Laid-Open No. 81-120331), 5i-N-
0 series thin film with a lubricating layer formed (Japanese Patent Application Laid-open No. 61-13
No. 1231) etc. were investigated, and the running properties and methyl resistance properties were investigated.

Efforts are being made to improve properties such as corrosion resistance.

Problems to be Solved by the Invention However, with the above configuration, the spacing loss, which increases as the recording wavelength becomes shorter, cannot be ignored9.
There was a problem that the necessary C/N could not be secured, and improvements were desired.

The present invention was made in view of the above-mentioned circumstances, and provides a durable magnetic recording medium with small spacing loss and good C/N in a short wavelength range.

Means for Solving the Problems In order to solve the above-mentioned problems, the magnetic recording medium of the present invention has a hexagonal zinc blende type and a hexagonal graphite type BN layered continuously on a ferromagnetic metal thin film. It was placed as a protective film.

The magnetic recording medium of the present invention has the above-described structure, and has good durability because the side closer to the ferromagnetic metal thin film is made of a hard macrogonal zinc blende type, and the surface layer is made of a graphite type with good slipperiness. Therefore, the protective film can be made thinner, spacing loss is reduced, and sliding noise is improved, resulting in an improvement in C/N.

Embodiment Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The figure is an enlarged sectional view of a magnetic recording medium according to an embodiment of the present invention. In the figure, 4 is polyethylene terephthalate, polyethylene naphthalate, polyamide, polyimide, polysulfone, polyphenylene sulfide, and polyether sulfone.

Polymer film such as polyetherimide, MgO, Al2O3, Ku205. GdO, CaW
A layer coated with fine particles such as O4°NiO may be provided.

5 is Go-Fe, Go-Ni, Go-Or,
Go-Ti, Go-Tz.

Go-8:L, Go-3m, Go-W, Go-
Mo, Go-0, Go-Ni-0, Go-O
It is a ferromagnetic metal thin film such as r-Nb, and the direction of the axis of easy magnetization is irrelevant, and the manufacturing method is not particularly limited. 6 is B
This protective layer is made of N and is configured to change from a hexagonal zinc blende type to a hexagonal graphite type in the thickness direction. With this configuration, it is possible to provide sufficient protection for 100 people starting from 6 o'clock. 7 is a lubricant layer, in which a commercially available lubricant such as perfluorocarboxylic acid, perfluoropolyether, fatty acid, etc. or a lubricant synthesized as necessary is coated with 30 to 100 layers by a solution coating method, a vacuum deposition method, etc. arranged and composed.

Examples of the present invention will be described in more detail below in comparison with comparative examples. On a polyethylene terephthalate film with a thickness of 10 μm, 100 (AO) particles with a diameter of 6 pieces/(μm)2 were arranged, and a Go-Or (9.8 w% Go Ni) perpendicular magnetization film was formed by high-frequency sputtering.
A thickness of 2 μm was formed. Further, along the cylindrical can with a diameter aocm, two boron vapor deposited films with a radius of curvature of 29 cM were placed adjacently as targets, and a high frequency of 13.56 (MHz) was sequentially applied in the direction of movement of the film. A BN film was formed using NH as a discharge gas. At this time, 900 (W) was applied to the target so that a hexagonal zinc blende type was formed from the surface of the ferromagnetic metal thin film, and then esoo (W) was applied to the target so that it changed to a graphite type. 40
A mixed phase of zinc blende type and graphite type containing about 2000 g of zinc blende type, and BN with a composition of about 3000 g of graphite type.
Formed as a protective film. Furthermore, as a lubricant layer, commercially available perfluorocarphonic acid KRYTOX manufactured by DuPont was added.
157 FS-M was applied and formed by about 60 people, and then an 8 mm wide magnetic tape was produced as a prototype.

On the other hand, in the comparative example, a diamond-like hard carbon film, which is considered to be harder than BN and suitable as a protective film, was used instead of the BN film using the hot filament CVD method [Journal of Precision Engineering, vol.
, 53, 1607-1610 (1987)] and 1
Comparative example B was prepared by forming 200 people. The configuration of the comparative example was otherwise the same as that of the example. Three types of 8mm tapes were modified into 8mm video, and a rectangular wave with a bit length of 0.2μm was recorded using a metal-in-gap magnetic head with a gap length of 0.12μm°, and the playback C/N was adjusted to a band of 1o (MHz). ) was evaluated.

If the comparison individual is Q (dB), the example is +1.1 (dB).
B), Comparative Example B was -3.9 (dB). on the other hand,
The speed at which the playback output decreases in the still state is -o
, e (dB/h), and the comparison individual is -3,4 (dB/h).
h), Comparative Example B was -o, 5 (dB/h). From these results, C
There is a difference of 5 (dB) in /N, which shows the usefulness of the present invention.

Effects of the Invention As described above, the present invention has the excellent effect of being able to provide an excellent C/N of 9 in high-density recording and reproduction.

[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 FIG. 2 is an enlarged sectional view of a conventional magnetic recording medium. 4...Polymer film, 6...Ferromagnetic metal thin film, 6...BN film (laminate of mostly zinc blende type and graphite type). Name of agent: Patent attorney Toshio Nakao and 1 other person 4-
Polymer film, 5”-,!i!!jaka4zukeboken6-B N order (
Hexagonal crystalline non-type and graphite type 111) Figure 1 251!

Claims (1)

[Claims] A magnetic recording medium characterized in that a protective film made of BN on a ferromagnetic metal thin film is composed of a continuous laminate of hexagonal zincblende type and hexagonal graphite type.