JPH01243236A - Manufacture of magnetic recording medium - Google Patents

Abstract

PURPOSE:To obtain a recording medium with a stable recording characteristic and superior durability by performing an orientation processing after forming a lubricant film on a magnetic recording layer. CONSTITUTION:In a magnetic recording medium, the magnetic recording layer is formed on a non-magnetic substrate. At the time of manufacturing the magnetic recording medium, the lubricant film is formed on the magnetic layer, and after that, the orientation processing is performed additionally. In the recording medium manufactured in such way, the arrangement of molecule on the lubricant film can be kept constant, and also, thickness is uniformized and nonuniformity can be eliminated, therefore, smoothness in the travel characteristics of the recording medium can be obtained, and the recording medium with the stable recording characteristic and superior durability can be obtained. Also, a processing suitable for mass production can be realized in the manufacturing method.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method of manufacturing a magnetic recording medium that is applied to the information industry and the like.

Conventional Technology γ-Fe203+C has been developed for the purpose of developing magnetic recording media for magnetic disks, magnetic tapes, etc.

Instead of coating-type magnetic recording media, which are made by dispersing ferromagnetic powder such as γ-Fe203 or CrO2 in an organic binder, there is currently a method of plating a ferromagnetic metal thin film directly on a non-magnetic substrate for the purpose of higher density. 2. Description of the Related Art Metal thin film magnetic recording media formed by sputtering, vacuum evaporation, ion blating, etc. are actively being developed.

However, the medium described above, when recording and reproducing information,
Durability is poor because it comes into contact with the head, cylinder, etc., and therefore requires a lubricating film on the medium.

Problems to be Solved by the Invention However, the friction and wear resistance that is the role of the lubricating film varies greatly depending on the material used, thickness, and manufacturing method, and constant durability may not be achieved. This means that due to insufficient formation of a lubricant film, the recording medium does not come into even contact with the head cylinder, etc. during running, and stable recording characteristics cannot be obtained due to adhesive wear and stick-slip. be.

Means to solve problems After forming a lubricating film on the magnetic recording layer, an orientation treatment is performed.

Recording media produced by orientation treatment after forming a functional lubricant film have a constant molecular arrangement and a uniform thickness, resulting in smooth running characteristics and stable recording characteristics. A recording medium with excellent durability can be obtained.

Examples The magnetic recording medium described in the present invention is made of polymeric materials such as polyamide, polyimide, polysulfone, polycarbonate polypropylene, polyethylene, polyethylene terephthalate, polycellulose acetate, and polyvinyl chloride;
Films, plates, etc. made of well-known materials such as non-magnetic metal materials, glass, ceramic materials such as porcelain, etc. are used as non-magnetic substrates,
One surface of the non-magnetic substrate is coated with at least one metal selected from Fe, Co, and Ni, or in contrast to these, Cr,
It is manufactured by forming a ferromagnetic metal thin film containing Ti, P, Y, Sm, Bi, etc. or an alloy of a combination of these oxides, and further forming a lubricating film on the metal thin film.

The orientation treatment described in the present invention can be performed, for example, by a method of manufacturing the surface of a lubricating film of a magnetic recording medium using a rubbing machine.

This will be explained in detail in Examples below.

Example 1 Co-Cr (wt%, Co:Cr=8:
A sample having a magnetic layer having a composition ratio of 2) and a thickness of 300 OA (AES analysis) was prepared. (Sample No. 1 is referred to as Sample No. 1.) Then, No. 1 is cut into a diameter of 60 mm, and stearic acid (1500 PPM of
Spin code (coat) 500 rpm 20 sec, dry 300 pm 20 sec, 2 times) to form a 50 A (2+) film with a thickness of 50 A (2+).
A lubricating film was formed (confirmed with a needle). (No, 2
) Furthermore, the surface of the lubricating film of No. 2 was rubbed with a rubbing machine equipped with a nylon non-woven part (manufactured by Hiroki Co., Ltd., NB-12) at a load (P) of 500 gf and a running speed (V) of 30 mm.
/s to obtain a recording medium which was subjected to alignment treatment by contacting the substrate 10 times in a fixed direction. (No. 3) The following sample was cut into a length of 50 mm and evaluated.

The evaluation was performed using a reciprocating friction tester with a 1.5R S U on the friction element.
Using J2, P=10gf, v=0.5mm/S,
The friction and wear resistance characteristics were examined at a running distance (L) of 20 mm. The results are shown in Table 1.

Table 1 According to Table 1, the coefficient of kinetic friction (μk) of untreated medium No. 1 on which no lubricant film is formed is higher than that of I Pa5s.At Pa5s, the coefficient of kinetic friction (μk) increases to 0.85 and more wear particles are generated. Was. Also, No. 2 is μ at the beginning.
Although k was low, μk similarly tended to increase as the number of runs increased. On the other hand, No. 3, which was prepared by orientation treatment after forming a lubricating film, had a 20%
Even in Pa5s, μ is as low as 0.2 to 0.23, and almost no change is observed over time.

From this, it was found that the recording medium on which a lubricating film was formed and subjected to orientation treatment as described in the present invention has excellent effects on friction and wear resistance. This is due to the fact that the orientation process reduces the friction and lubrication of solids.
This is thought to be due to the improved orientation of the lubricating film, as described in "PtO2, round neck (560)".

Example 2 A magnetic recording medium in which Co--Cr (thickness: 1500 A) was deposited on a polyamide substrate having a thickness of 10 μm in the same manner as in Example 1 was subjected to orientation treatment using the samples shown in Table 2 under the following conditions.

(Margin below) Table 2 In No. 4, the standard deviation (δμk) of No. 11 was 0.05 smaller than that of the sample without orientation treatment, and exhibited very smooth friction characteristics. Also, the thickness of the lubricating film is N
Even when o is as large as 5.6, /lk is about 0.15 smaller both at the initial stage and at 20 Pa5s compared to when no orientation treatment is performed, and this effect becomes more pronounced as the number of runs increases. Ta. When the rubbing process is performed in this way, δμ and μk during one stroke become smaller,
It can be seen that the above-mentioned rubbing treatment as described in this example can be expected to have sufficient effects.

Effects of the Invention The magnetic recording medium obtained by orienting the lubricating film according to the present invention has a low and stable coefficient of friction, thereby providing smooth recording characteristics and excellent durability. Moreover, this manufacturing method is a method that can be processed quickly and is suitable for mass production.

Claims (1)

[Claims] In a method for manufacturing a magnetic recording medium including a magnetic recording layer on a non-magnetic substrate, after forming a lubricating film on the magnetic recording layer,
A method of manufacturing a magnetic recording medium, further comprising performing an orientation treatment.