JPS5832233A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To increase the thickness of a film and to increase the heat resistance for a magnetic recording medium, by adhering a magnetic film formed with the metallic magnetic powder having a specific size to a nonmagnetic substrate. CONSTITUTION:A magnetic coating material containing 60-70wt% metallic magnetic powder having 0.6-1.0mum long axis diameter is coated on a nonmagnetic substrate of Al, etc. with 70mum film thickness. A magnetic field is orientated to the substrate. Then the substrate is baked and magnetized to obtain a magnetic film which has >=150 deg.C heat resistance and can increase its thickness. Thus a magnetic recording medium which has high reliability and high coercive force is obtained to be used for a magnetic encoder.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic recording medium, and particularly to a magnetic recording medium for use in a magnetic encoder that enables high reliability and high coercive force.

As general E1m memory devices, magnetic tapes used in Audio IIK, magnetic disks and magnetic drums used in computers, etc. are known. and,
The magnetic film of these magnetic recording bodies has a high wsue capsule and is extremely thin with a film thickness of 0.2 to several μm. child is used. On the other hand, the magnetic recording body used in the iI magnetic encoder is
ag & detection element and magnetic recording body (disk or driver 74
) and 1JI&I interval is large, from mold μm to several hundred μm! l
! Steels with larger lI properties can meet the requirements for high coercive force. In order to obtain a high coercive force, metal (?
・S) is used, and a film thickness of 50 to 100 μm is required. On the other hand, at @reliability 0 point, the magnetic encoder is used in a wide range of environments, so the temperature is approximately 150°C.
Higher heat resistance is required. In order to improve the IfIfK heat resistance, conventional magnetic powders can only guarantee temperatures up to about 5 ocsi degrees, and there are also problems such as occurrence of defects in thick film formation, occurrence of S cracks, and difficulty in uniform coating. 011 for magnetic encoders with excellent distance, reliability, and heat resistance.
! It was very difficult to obtain 111.

Therefore, the present invention is directed to the use of metal powder particles IIO large a
By forming the magnetic II using a magnetic material, the thickness II
The purpose of the present invention is to provide a magnetic recording body TM which has high performance and heat resistance.

Honko WA using the following examples! Explain in detail.

In the present invention, as a magnetic disk, a substrate made of an O non-magnetic material such as Mut is cleaned, and an S-based paint with metal powder added thereto is spread on the substrate to a thickness of about 100 mm using a spinner method, and magnetic field orientation is applied. After baking and magnetizing, the magnetic recorder is completed.

In this case, the metal powder/O filling amount (metal powder/O weight ratio in 11 excluding the AI agent) was set at 65% by weight, the binder was epoxy resin, and the binder was toluene. No, and as a result of the inventor's repeated experiments and studies under various conditions,
It has been found that the size of the major axis diameter rO of k@ terminal O greatly influences heat resistance. In other words, as an experiment, the long axis @ri
Instead, various metal powders were made into paints and high temperature II (
(approximately 150℃) Adjusting the magnetic detection force for the life time in 1111, the result is 4141k in 111m1
I (r= 0-41"'a) I 4'i II (
r, = O-6 μm) *41 property” (r = 0-7
Jm) m 1113M (r -04") e41 V (rml, OjIm) J W (r-1-2μm)
It was found that the field where the major axis @r of the main Is-union terminal O is in the range of 0.6 to 1.0 μm is optimal for obtaining an output higher than the comparative value.9. In the case of O, if the long axis 11r of the metal powder is 0.6 μm or less, the heat resistance effect is not sufficient for Fi practical use, and l・0
If it is more than μm, it is hoped that the thickness will be effective and the S-field thickness will become easier, but the output (magnetic force) of the magnetic detection element OvJ period will be insufficient, which is 1m@I [gi].

Then, considering the quality limit, the optimum range for the major axis diameter r of the metal powder is 0.7 to 0.8 AnxO. Considering the deviation (pack dP), the optimum range is 0.・8
The best value after μm □ μm is 6.9, and the amount of metal powder filling of the -legal paint is about 70 Wt (if it is more than 70 Wt, cracks are likely to occur in the formed magnetic steel), and it is about 60 μ or less. This will result in the formation of air bubbles in the magnetic bowl.

Therefore, considering the quality limit, the optimum range was the metal filling amount Fi65±5vt%O. front,
The magnetic field thickness is shown at 92m.The magnetization pitch is 0.1-5.
In the case of , the film thickness is approximately 70x because it is proportional to the -qi detection output.
When it becomes more than m, the output becomes approximately jii. However, there is a difference between obtaining high output and proceme (back dP
), the output will be slightly saturated and the film thickness will be stable, forming a thick film of approximately 804ml. #i^
stomach.

Note that in the *example above, the problem was solved when a disk was used as the magnetic recording body, but the main hole f! is not limited to this, and even if a drum is used, it can be done in the same way.
Of course, it is effective.

As mentioned above, according to the present invention, it is possible to provide a highly reliable magnetic encoder that has heat resistance of about 150° C. or more and is capable of producing a thick 111-degree sea bream. You can get the same effect.

[Brief explanation of drawings]

FIG. 1 is a characteristic diagram showing the relationship between the output of the magnetic sensing element and the life time using the major axis diameter of the metal powder as a parameter, and FIG. 2 is a characteristic diagram showing the relationship between the output and the magnetic film thickness. Part 1 II #r'MriI(gi)AI)

Claims (1)

[Claims] 1. A magnetic recording medium comprising a magnetic film deposited on a non-magnetic substrate, characterized in that the magnetic film is formed of metal magnetic powder having a particle size of 0.6 to 1.0 μm.