JPS6018871A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To improve the resistance to scratching and wear of a magnetic recording layer by incorporating a higher fatty acid into a non-woven fabric. CONSTITUTION:The non-woven fabric to be used is of rayon, PP, polyester, etc. and the preferred thickness is 50-500mu. The high fatty acid includes a satd. fatty acid and unsatd. fatty acid, both of which are usable. There are caprylic acid, pelargonic acid, capric acid, n-undecylenic acid, lauric acid, etc. as the satd. fatty acid and there are a dodecenoic acid, tetradodecenoic acid, hexadecatrienoic acid, etc. as the unsatd. fatty acid. Incorporation of the higher fatty acid into the non-woven fabric entails simply immersion of the non-woven fabric into the liquid prepd. by mixing and dissolving the higher fatty acid in water or a solvent such as org. solvent. The manufacture of a magnetic recording medium is accomplished merely by providing a magnetic recording layer on a non-magnetic base such as a polyester film by electroplating, chemical plating, vacuum deposition, etc., then blanking the base to a prescribed size to form a magnetic disc body and inserting the magnetic disc into a plastic case to the inside surface of which the non-woven fabric incorporated therein with the higher fatty acid is stuck.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a magnetic recording medium in which a magnetic disk body having a magnetic recording layer provided on a non-magnetic support is inserted into a plastic case with a non-woven fabric pasted on the inner surface.

Prior art perpendicular magnetic recording (Iv) is an Nj2 recording medium that simply provides a magnetic easy axis in the perpendicular direction and is magnetized in the perpendicular direction for recording and reproduction. It is suitable for high-density recording because the magnetic field is reduced. The magnetic recording layer of this type of recording medium is made of Co thread, Co-P
Many metal magnetic thin films have been proposed, including a single layer or a combination of one or more layers.

However, although the metal magnetic thin film is suitable for high-density recording, it has the drawback that it has high hardness and wears out the magnetic head, and the metal thin film itself is easily scratched and worn.

For this reason, many proposals have been made in the past in which a protective film is formed on the surface of a metal magnetic thin film. For example, a very thin film of higher fatty acid is deposited on a metal magnetic thin film.

Adhesion is achieved by applying a coating liquid, which is prepared by mixing and dissolving various lubricants together with an adhesive in a solvent such as water or an organic solvent, and dispersing the mixture onto the surface of the magnetic film. However, it tends to cause uneven coating,
It has the disadvantage that its performance deteriorates due to environmental changes, such as drying due to high temperatures. Furthermore, the scratch resistance and abrasion resistance could not be sufficiently improved.

Purpose An object of the present invention is to solve the above-mentioned drawbacks and provide a magnetic recording medium with excellent scratch resistance and wear resistance.

Structure In the present invention, a magnetic disk body having a magnetic recording layer provided on a non-magnetic support is inserted into a plastic case with a non-woven fabric attached to the inner surface, and the magnetic disk body rotates with the magnetic recording layer in contact with the non-woven fabric. The magnetic recording medium is characterized in that the non-woven fabric contains a higher fatty acid.

Nonwoven fabrics used in the present invention include rayon, polypropylene, and ester ester.

The thickness is preferably 50 to 500μ.

For example, vinyl chloride resin can be used for the plastic case. The wall thickness of the case is not particularly limited, and may be a flexible case or a hard case with little deformation.1 Higher fatty acids include saturated fatty acids and unsaturated fatty acids, and both can be used. Specifically, saturated fatty acids include caprylic acid, pelargonic acid, and capric acid.
en-undecylenic acid, lauric acid, n-)ridecylenic acid, myristic acid, n-pentacosanoic acid, nozormitic acid, marker IJ acid, stearin flit, n-nonacosanoic acid, alaxin[, n-heneicosanoic acid, behenin &, n-tricosanoic acid, lignoceric acid, n-pentacosanoic acid, cerotic acid, n-hecitacanoic acid, montanic acid, n-nonacosanoic acid, melisic acid, n-hentriacontanoic acid, n-todoriacontane ISL n- These include tetratriacontanoic acid, cellocilastinic acid, n-hexatriacontanoic acid, n-octatriacontanoic acid, and n-hexatetracontanoic acid. Unsaturated fatty acids include dodecenoic acid, tetradecenoic acid, hexadecatrienoic acid, petroselic acid, oil sauce, linoleic acid, lilunic acid, 6,9.12-
Octadecatrienoic acid, icosenoic acid, icosadienoic acid, icosatrienoic acid, icosatetraenoic acid, icosapentaenoic acid, erucic acid, docosadienoic acid, docosatrienoic acid, docosatetraenoic acid, docosapentaenoic acid, docosahexaenoic acid, tetraenoic acid , hexacosenoic acid, hexacosenoic acid, oftacosenoic acid, and todoacontanoic acid. These may be used alone or in combination. The appropriate amount used is 1 to 20 parts by weight per 100 parts by weight of the nonwoven fabric.

In order to incorporate higher fatty acids into a nonwoven fabric, the nonwoven fabric may be immersed in a solution in which higher fatty acids are mixed and dissolved in a solvent such as water or an organic solvent. At this time, a binder and other additives may be added to the above-mentioned solution, or the higher fatty acid may be encapsulated by well-known encapsulation and then dipped and attached to a nonwoven fabric in the same manner.

The magnetic recording layer is made of a metal magnetic thin film, 5-Co-P system, Co system, Co-Fe system, Co-Ni system, C.

-Cr type, F@-Nl type, etc. are used in combination with a single layer or a multilayer.

To make the magnetic N1 recording medium of the present invention, electroplating, chemical plating, etc.
A plastic case with a magnetic recording layer formed by vacuum evaporation, sintering, ion blating, etc., punched out to a predetermined size to form the magnetic disk body, and a nonwoven fabric containing higher fatty acids affixed to the inner surface. The magnetic disk may be inserted into the .

In use, the magnetic recording layer contacts the nonwoven fabric, the magnetic disk body rotates, the case remains stationary, and the magnetic recording head contacts the rotating disk.

Effects According to the present invention, since the higher fatty acids contained in the non-woven fabric can be stably and minutely supplied to the surface of the magnetic recording layer over a long period of time, the scratch resistance and abrasion resistance of the magnetic recording layer are improved, and the magnetic head is improved. Wear is also reduced.

The effects of the present invention will be specifically illustrated by examples below.

Example 1 First, a magnetic recording medium having a cross section as shown in FIG. 1 was manufactured. That is, a polyester film support 1 with a thickness of 75μ
A 0.5μ thick Fe-N1 film was deposited on top by sputtering.
A layer 2 was provided, and a 0.5 p thick Co--Cr layer 3 was also provided. This was punched out to the size of a 5.25-inch magnetic flexible disk to produce a magnetic disk body 4.

Next, a nonwoven fabric made of rayon with a thickness of 300 μm was immersed in a mixture of 100% stearic acid and a mixture of toluene and methyl ethyl ketone (mixing ratio 1:1), and then dried. This nonwoven fabric was attached to a plastic plate made of vinyl chloride by heat-sealing dots and folded in half to produce a plastic case. Furthermore, a magnetic disk body 4 was inserted into a plastic case 6 to which a nonwoven fabric 5 was pasted 9 to form a magnetic recording medium.

Next, as shown in FIG. 2, the magnetic disk body 4 is brought into contact with the opposing main magnetic pole 7 (2μ thick e-Malloy thin film sandwiched between glass plates) and auxiliary magnetic pole 8 (Mn-Zn ferrite). Recording and reproduction were repeated with the magnetic recording medium (Example 1) narrowed. For comparison, a nonwoven fabric was not immersed in stearic acid (Comparative Example 1), and a nonwoven fabric was immersed directly in the stearic acid mixture to adhere stearic acid to the thin M surface (Comparative Example 2). ),
These recordings and reproductions were repeated in the same manner.

The number of times recording and reproduction was repeated until scratches occurred and the number of times until the output during reproduction reached the starting level of 50 Yu were measured. The results were as shown in the table below.

(The following is a blank space) It can be seen that the magnetic recording medium of the present invention has much better side scratch resistance and wear resistance than the conventional magnetic recording medium.

Examples 2 and 3 Behenic acid (Example 2) was used instead of stearic acid in Example 1.
), except that oleic acid (Example 3) was used (Example 1)
In the same manner as above, the number of times until scratches occurred and the number of times until the output reached 50% were measured. The results were as shown in the table below.

9-

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of a magnetic recording medium used in an embodiment of the present invention, and FIG. ! 5i! This is a clear diagram. 4...Magnetic disk body 5...Nonwoven fabric 6...Plastic case 110-

Claims (1)

[Claims] 1. A magnetic disk body having a magnetic recording layer provided on a non-magnetic support is inserted into a plastic case with a non-woven fabric attached to the inner surface, and the magnetic recording layer is in contact with the non-woven fabric and the magnetic disk body is What is claimed is: 1. A magnetic recording medium having means for rotating the nonwoven fabric, characterized in that the nonwoven fabric contains a higher fatty acid. 2. The magnetic recording medium according to claim 1, wherein the magnetic recording layer is made of a metal magnetic thin film.