JPS61120342A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To satisfy both of output fluctuation and durability by providing a protective layer on a magnetic layer and providing further a porous layer consisting of a material having the hardness smaller than the hardness of a magnetic head and a lubricating layer consisting of a liquid lubricating agent incorporated into said porous layer. CONSTITUTION:This magnetic recording medium has the magnetic layer formed on at least one surface of a substrate, the protective layer which is formed on said magnetic layer and consists of the material having the hardness equal to or higher than the hardness of the magnetic head, the porous layer which is formed on the protective layer and consists of the material having the hardness smaller than the hardness of the magnetic head and the lubricating layer 16 consisting of the liquid lubricating agent incorporated into said porous layer. The coefft. of friction of the layer 16 is 1/5-1/10 coefft. of friction when said layer is flat. The liquid lubricating layer 15 is retained in said layer without starvation for a long period of time. The porous layer 14 forming the layer 16 is formed of the material having the hardness smaller than the hardness of the magnetic head and therefore the wear of the magnetic head is small and even if foreign matter having the large hardness intrudes into the traveling surface, the lubricating layer is injured to protect the magnetic head. The sliding strength of both of the magnetic recording medium and the magnetic head is improved by the combination of the protective layer 12 and the lubricating layer 16.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a magnetic recording medium C.

[Technical background of the invention and one point in between]

In recent years, a perpendicular magnetization recording method that performs high-density recording using residual magnetization in a direction perpendicular to the magnetic mmt of a magnetic recording medium has attracted attention.

Presbyopic magnetization recording medium (hereinafter referred to as single C@) for perpendicular magnetization recording
A typical example of a magnetic recording medium is a Cr-based thin film that has two easy axes of magnetization in the direction perpendicular to the film surface (C). .

The substrate on which this magnetic layer is formed is a heat-resistant film such as polyimide or polyethylene terephthalate (PIT).
A polymeric film such as a film or aluminum is used, and at least one surface of the substrate is coated with C2Co-Cr.
It is created by forming a thin film based on sputtering.

Magnetic recording media made of CI in this manner are particularly suitable for use in Nifty disks.

This floppy disk) 1 As is well known, it is disc-shaped and is housed in a national polka dot called a jacket. Then, if you want to record or play back on a floppy disk, for example, 300 revolutions per minute or 600 revolutions per minute [! ! Rotate at 1 revolution/min and apply a constant load to the i-vent.

By the way, when performing high-density recording using perpendicular magnetic recording, if there is an inappropriate unevenness on the surface of the general Cla layer, the distance between the magnetic head and the magnetic layer surface will differ for each bit.
Because of the problem of causing output fluctuations, it is required that the surface of the 6fl layer be smooth.

On the other hand, since the magnetic recording medium rotates while being in pressure contact with a magnetic head made of ferrite or the like, the surface of the C2 magnetic recording medium (bivalence is likely to occur) during long-term operation.

Recording and playback output decreases in this scratched area. In order to reduce the occurrence of this scratch and improve durability, C2Co-C
Surface C of r-based and other magnetic layers: Complete formation of protective protection.

Furthermore, a method is known in which a liquid lubricant is applied to the surface of this protective layer.

However, when a magnetic recording medium with a very smooth surface is combined with a magnetic head, the coefficient of friction between the two becomes large.
This friction scrapes at least one of the magnetic recording medium and the magnetic head, causing fine powder that is thought to be generated when the magnetic head C2 is fixed.

This may cause scratches on the magnetic recording medium or magnetic head, reducing their durability.

Magnetic recording media with magnetic layers formed by sputtering with 5C:, N, t, and various other vacuum film-forming methods have many problems with durability (two problems include output fluctuations and durability). It was extremely difficult to simultaneously satisfy the two sexual problems.

[Purpose of the invention]

The above invention has been made in view of the above-mentioned problems, and an object thereof is to provide a magnetic recording medium that can satisfy both output fluctuation and durability! The purpose is

[Summary of the invention]

a magnetic layer formed on at least one surface of the substrate; A protective layer made of a material with a hardness equal to or higher than that of the magnetic head formed on this magnetic layer, a porous layer made of a material less hard than the magnetic head formed on this protective layer, and this porous layer (= A magnetic recording medium characterized by having a lubricating layer comprising a liquid lubricant contained therein.

[Embodiments of the invention]

Next, the magnetic recording medium of the present invention will be explained in the order of its steps with reference to FIGS. 1 to 5.

First, as shown in FIG. 1, a heat-resistant film such as a polyimide film, a polymer film such as a polyethylene terephthalate (PFfT) film, or a substrate α [such as IT aluminum] is coated with, for example, 0.0% by sputtering on both surfaces.
A magnetic layer συ made of a Co-Cr alloy thin film of 5 to 1.0 μm is formed.

Next, as shown in FIG. 2, a layer harder than the magnetic head, such as AJ!, is placed on the magnetic layer riv. A protective layer (I) is formed by sputtering to form a protective layer (I
form.

Next, as shown in Figure 3, a porous layer αJ is formed by simultaneous sputtering from a material with a lower hardness than the protective rfI (12) head, such as a N1-Cr alloy and a different target. The ratio of Ni-Cr and A in this angioporous layer U is N1-Cr:Ni-Cr:N1
: 0.3 to 3.0.

Next, a NaOH solution is applied to this porous layer αJ,
Aljf is dissolved and porous ma4) as shown in FIG. 4 is formed.

next! As shown in Fig. 115, a porous layer (I4) (contains a two-liquid anti-lubricant agent (L!9) to form a lubricating layer field, and the magnetic recording medium! is completed.

Such a lubricating layer (IQ is the case where the coefficient of friction is flat)
115 to 1/10, and the liquid lubricant a9 does not run out over a long period of time. In addition, the lubricating layer (the porous layer forming the le) is made of a material C2 which has a smaller hardness than the magnetic head, so the la magnetic head wears out! Even if small, hard foreign objects enter the running surface, the lubricating layer will be damaged and protect the magnetic head. Furthermore, the combination C2 of the protective layer a2 and the lubricating layer (161) improves the sliding strength of both the magnetic recording medium and the magnetic head.

Such a lubricating layer (161) has a thickness of 300 to 50A, and a protective layer (I7J and lubricating layer aeya - the combined thickness t
From the viewpoint of the characteristics of the magnetic recording medium, it is desirable that the average diameter is 3008 or less.

In the embodiments described above, N1-Cr was used to form the porous layer.
-Alloy and A4 were sputtered at the same time, but the invention is not limited to this. Nl-Cr alloy was sputtered using a combination of N1-Cr alloy and Teflon, and a mixture of ceric ammonium nitrate and perchloric acid was used as an etching solution. May be dissolved.

〔Effect of the invention〕

As described above, according to the present invention C2, an upper protective layer is provided on the Iia layer, and a porous layer (= a porous layer made of a material having a hardness smaller than that of the magnetic head) and a liquid lubricant containing a By providing a lubricating layer consisting of a lubricating agent, the durability of the magnetic recording medium is improved, and between the magnetic recording medium and the magnetic head L: Even if hard foreign matter gets mixed in, only the lubricating layer will be damaged and the magnetic head and magnetic head will be damaged. It has the effect of not damaging either side of the recording medium.

[Brief explanation of drawings]

Figures 1 to 5 are explanatory cross-sectional views showing the manufacturing process of the magnetic recording medium of the present invention in order of process. 10...Substrate 11...Magnetic layer 12.
...Protective layer 13...Porous layer 14...
・Porous layer 15...Liquid lubricant 16...
Lubricant layer

Claims (1)

[Claims] (1) A magnetic layer formed on at least one surface of the substrate, a protective layer formed on the magnetic layer and made of a hard material equivalent to or higher than the magnetic head, and the magnetic layer formed on the protective layer. 1. A magnetic recording medium comprising a porous layer made of a material having a harder hardness than that of a head, and a lubricating layer made of a liquid lubricant contained in the porous layer.