JPS61237222A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To obtain the titled medium having excellent lubricity and wear resistance by forming a polyphenyl ether film on the surface of a ferromagnetic metallic thin film provided on a nonmagnetic substrate and forming a layer contg. an aliphatic amine lubricant on the film surface. CONSTITUTION:A ferromagnetic metallic thin film 2 is formed on a nonmagnetic substrate 1, a polyphenyl ether film layer 3 is formed thereon and further a layer 4 contg. an aliphatic amine lubricant is formed thereon. A high molecular material such as polyvinyl chloride and cellulose acetate or a ceramic material such as glass is used as the nonmagnetic substrate 1. An alloy consisting of a combination of iron, cobalt, etc., and manganese, chromium, etc., or the oxides of the metals is used as the ferromagnetic material for forming the ferromagnetic metallic thin film 2. The metallic thin film 2 is formed by plating or vapor deposition. The polyphenyl ether film 3 is formed by electrolytic polymerization, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a high recording density magnetic recording medium used in the information industry and the like.

Conventional technology For such high-density magnetic recording media, ferromagnetic metal gonolayer is plated or vapor-deposited on a non-magnetic support.

Research is being conducted on materials formed by methods such as sputtering and ion blating.

However, in such magnetic recording media, since metal is exposed on the surface of the magnetic layer, friction due to relative movement with a magnetic head, etc. during magnetic recording and reproduction is large.
There is a problem that the strength of the membrane is low and the running durability is low.

Under these circumstances, it has been proposed to provide an aliphatic amine lubricant on a ferromagnetic metal thin film (Japanese Unexamined Patent Application Publication No. 1983-1999).
119538).

Problems to be Solved by the Invention However, although there has been an improvement in lubricity in this case, wear resistance is still not sufficient. This is because the adhesion strength of the aliphatic amine lubricant film is weak, and the underlying ferromagnetic metal thin film can be damaged by minute dust particles while the vehicle is running.

The present invention has been made to address these problems, and an object of the present invention is to provide a magnetic recording medium with excellent lubricity and wear resistance.

Means for Solving the Problems A polyphenyl ruble film is formed on a ferromagnetic metal thin film provided on a nonmagnetic metal plate, and an aliphatic amine lubricant-containing layer is provided on the surface of this film.

Function: The polyphenyl ether film layer, which is an aromatic polymer having the characteristics of high hardness and high elasticity, can prevent scratches on the ferromagnetic metal thin film, and it also has a layer containing an aliphatic amine lubricant. As a result, a magnetic recording medium with excellent lubricity can be obtained. It is believed that the aliphatic amine chemically bonds with the terminal OH group of the polyphenyl ether film, resulting in sustained good lubricating properties.

Example The figure is a cross-sectional view of the magnetic recording medium of the present invention.

In the figure, 1 is a non-magnetic substrate, 2 is a ferromagnetic metal thin film formed on the non-magnetic substrate 1, on which a polyphenyl ether film layer 3 and an aliphatic amine lubricant-containing layer 4 are sequentially provided. It is being

Examples of the nonmagnetic substrate 1 that can be used in the magnetic recording medium according to the present invention include polyvinyl chloride, cellulose acetate,
There are films, plates, etc. made of well-known materials such as polymeric materials such as polyethylene terephthalate, polyethylene, polypropylene, polycarbonate, polyimide, and polyamide, nonmagnetic metal materials, and ceramic materials such as glass and porcelain.

Further, as the ferromagnetic material forming the ferromagnetic metal thin film 2 that can be used in the magnetic recording medium of the present invention, any known material can be used, such as an alloy of one or more of iron, cobalt, and nickel, or an alloy of these. other metals, such as manganese,
There are alloys that combine chromium, titanium, phosphorus, yttrium, samarium, bismuth, etc., as well as oxides of the above metals.

In forming the ferromagnetic metal thin film 2 on the nonmagnetic substrate 1, any known method such as plating, vapor deposition, sputtering, ion blating, etc. can be used.

Further, in providing the polyphenyl ether film 3 on the ferromagnetic metal thin film 2, electrolytic polymerization method, plasma polymerization method, gas phase photopolymerization method, etc. can be used. In order to create the polyphenyl ether film 3, the gas phase photopolymerization method is excellent. In addition, since the polyphenyl ether film 3rd produced by this method does not dissolve in water*ethanol, acetone, methylene chloride, and toluene, it is presumed that it is a highly crosslinked polymer.

The thickness of the polyphenyl ether film according to the present invention is
Suitable for 60-400 people. Generally, the above film thickness is 400
If it is larger than a person, the output will decrease due to spacing loss when reproducing the recorded signal, which is undesirable.
As the size becomes smaller, pinholes are more likely to form, reducing the strength of the film.

The aliphatic amine that can be used in the aliphatic amine lubricant-containing layer 4 provided on the polyphenyl ether film 3 described above is preferably a compound having a hydrocarbon chain having 14 to 24 carbon atoms. No further improvement in lubricity is observed with aliphatic amines having a hydrocarbon chain having 13 or fewer carbon atoms.

Aliphatic amine lubricants that can be used in the present invention include tetradecylamine, pentadecylamine, hexadecylamine, heptadecylamine, stearylamine, nonadecylamine, eicosanylamine, heneicosanylamine, behenylamine, and tricosanylamine. , lignoserylamine. In forming the aliphatic amine lubricant-containing layer 4 on the polyphenyl ether film 3, methods such as a vacuum deposition method and a coating method can be used.

When forming the aliphatic amine lubricant-containing layer 4 on the polyphenyl ether film 3 according to the present invention, the film thickness is preferably 60 to 300 layers. However, the combined thickness of the polyphenyl ether film 3 needs to be 500 Å or less. If the number of participants is larger than 500, it is not preferable because the output will decrease due to spacing loss when reproducing recorded signals. Furthermore, if the thickness of the aliphatic amine lubricant-containing layer is less than 60 mm, the lubricity will decrease, which is not preferable.

Note that even if the aliphatic amine lubricant-containing layer contains 6 or less impurities other than aliphatic amines, the lubricity will not be impaired.

The present invention will be explained below by giving specific examples.

Examples 1 to 6 A ferromagnetic metal thin film with a thickness of 1500 Å made of cobalt (AO%)-chromium (20%) was formed on a polyimide film substrate with a thickness of 20 μm by vacuum evaporation. A phenyl ether film was prepared from the substrate on which this ferromagnetic metal thin film was formed. By measuring the thickness with an ellipsometer,
This polyphenyl ether film had a weight of 300. Next, various aliphatic amines were used as evaporation sources, and 5×10
A lubricant-containing layer having a thickness of 20 OA was formed in an atmosphere of 200 torr to obtain Examples 1 to 6 shown in the table.

Comparative Example A ferromagnetic metal thin film was formed on a polyimide film substrate under the same conditions as in Example. A lubricant-containing layer having a thickness of 20 OA was formed on this ferromagnetic metal thin film in an atmosphere of 5×10 torr using various aliphatic amines as evaporation sources to obtain Comparative Examples 1 to 6 shown in the table.

The following measurements were performed for each of these samples.

(1) Dynamic friction coefficient The kinetic friction coefficient of the sample was measured using a kinetic friction coefficient needle (DF-PM manufactured by Kyowa Interface Science Co., Ltd.) under the conditions of 25°C and 16° fiRI.The head used had a diameter of 12ffll1.
1 steel ball, head load 107. Head running speed 1.
0fflIII/! Measurements were made using ieC at the initial stage and after 200 times of sliding.

(21 Running Durability Sample) The running durability sample was run on a testing machine having the same function as a commercially available floppy disk drive, and after 100 hours, the occurrence of scratches was examined by microscopic observation.

From the data in the table, it can be seen that the dynamic friction coefficients of the magnetic recording media of Examples 1 to 6 according to the present invention are very small at the initial stage and after 200 times of sliding, and are superior to Comparative Examples 1 to 6. Furthermore, regarding durability, scratches were observed on the ferromagnetic metal film in all of Comparative Examples 1 to 6 after 100 hours of sliding on a testing machine with the same function as a floppy disk, but Examples 1 to 6 showed scratches on the ferromagnetic metal film. 6, no scratches were observed.

Effects of the Invention The magnetic recording medium according to the present invention has excellent lubricity and good wear resistance.

[Brief explanation of drawings]

The figure is a sectional view of a magnetic recording medium in an embodiment of the present invention. 1...Nonmagnetic substrate, 2...Ferromagnetic metal thin film, 3...Polyphenyl ether film,
4...Aliphatic amine lubricant containing layer.

Claims (3)

[Claims] (1) A magnetic recording medium in which a polyphenyl ether film is formed on the surface of a ferromagnetic metal thin film provided on a nonmagnetic substrate, and an aliphatic amine lubricant-containing layer is formed on the surface of this film. (2) The thickness of the polyphenyl ether film is 50 to 4
The magnetic recording medium according to claim 1, wherein the magnetic recording medium has a thickness of 00 Å. (3) The number of carbon atoms in the aliphatic amine lubricant is 14 to 24
A magnetic recording medium according to claim 1.