JPS58224438A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To improve the durability of a metallic thin film type magnetic recording medium, by piercing a prescribed number of pinholes having a prescribed size in the magnetic film of the medium and by filling a lubricant into the pinholes. CONSTITUTION:Fine pinholes are pierced in a metallic thin film type magnetic recording medium so that the product of the diameter (phimum) measured at the surface and the number per unit area (mum<2>) is made 0.05-0.5. A lubricant is filled into the pinholes. The preferred lubricant is fluororesin. Other polymer lubricant such as silicone may be used. Thus, the durability of the magnetic recording medium is remarkably improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to metal thin film magnetic recording media. Magnetic metal or alloy thin films produced by plating, vacuum evaporation, sputtering, etc. are considered to be promising as future high-density magnetic recording media. ing.

Metal thin films include alloys of Fe, NI, Co, and c
Various alloy compositions have been proposed, such as alloys such as r, and the C--Or alloy f# film produced by sputtering has a strong magnetic orientation in the direction perpendicular to the film surface. Perpendicular magnetic recording (Unexamined Japanese Patent Publication No. 11i
No. 352-134706), research is being actively conducted in various fields for its early practical application.

However, these metal NI model magnetic recording media have problems such as a stick-slip phenomenon occurring due to the large coefficient of friction when the magnetic head used for recording and reproduction is brought into contact and moved relative to each other, and lacks durability. It was defective.

The present invention was made in view of the above situation, and the product of the diameter φ (1 m) and the number N (pieces/μ−) per unit area when measured at the surface of a metal thin film magnetic recording medium is , C.L.O.
5(μm-(solid/μm2) to l15(μm・pieces/μm
It is characterized by forming minute pinholes in the range of m) and filling the pinholes with a lubricant. According to the present invention, the durability of metal thin film magnetic recording media is dramatically improved.

As will be described in detail later, it has been found that the best recording medium can be obtained when the product of the diameter (average diameter, same hereinafter) of the via holes and the number of holes per unit area (μm 11) is within the above range. If the above product is less than α05 μm pieces/μml, friction and wear on the magnetic head will increase and durability will decrease.On the other hand, if this product is 15 μm pieces/μm1
Above that, the non-magnetic material (i%il lubricant) against the magnetic material
The area ratio becomes too large, which is not preferable. Also, the maximum diameter of the pinhole must be sufficiently smaller than the recording wavelength, and 1
It should be 2 μm or less.

The lubricant used is preferably a fluororesin, but other polymeric lubricants such as silicone lubricants may also be used.

Hereinafter, the present invention will be explained in detail with reference to Examples.

Example 1 A vertically oriented C9-Cr film with a thickness of [L5 μm] was completely formed by sputtering on a polymer substrate in which pinholes with a diameter α1 μm were present on the surface at a ratio of one pinhole per snore. did. On the surface of the C@-Cr film, pinholes on the substrate surface were repelled, and pinholes with a diameter ct1 μm were present at a ratio of 1/μm8.

After filling the pinhole with a fluorine-based lubricant, a flexible disk was produced by punching.

When the durability of the disk in contact with a magnetic head was evaluated using a flexible disk durability tester, very good results were obtained, with no decrease in output or increase in errors observed even after 1,000,000 busses.

Comparative Example A Co-Cr sputtered film (thickness a5 (μm)) was prepared without intentionally forming pinholes, a fluorine-based lubricant was applied to the surface, and a flexible disk durability test was conducted. After 1 million passes, the average output attenuated by approximately 20% and the error increased by a factor of 104.

Example 2 Diameter φ (μm) and number per unit area N (pieces/μmm
) The durability was evaluated by varying the product of Fig. 1.
Obtained the results shown in O φN>0.05 (Jim, pieces/μm") Te sudden tC
It can be seen that the durability has improved q φN>[L'5 (μm-pcs/tt wr ”)
The surface area and durability Th were good, but the area ratio of the non-magnetic material (ill lubricant) to the magnetic material was too large, which was not desirable for practical use.

[Brief explanation of the drawing]

The drawing is a graph showing a shadow 11 in which the product of the pinhole diameter and the number density does not reach the durability. ; iris (-=°≦k)

Claims (2)

[Claims] (1) The product φN of the diameter φ (μm) and the number N per unit area (pieces/μml) when measured at the surface of the magnetic layer of the metal thin film magnetic recording material is 0.05 to CL 5 μm pieces/μm. 1. A magnetic recording medium characterized in that a pinhole in the range of 10 μm is formed and the pinhole is filled with a lubricant. (2) The magnetic recording medium according to item 1 above, wherein the lubricant is a fluorine-based lubricant.