JPS63102040A - Production of magnetic recording medium - Google Patents

Abstract

PURPOSE:To improve durability by disposing a lubricating agent by a solvent coating method on a thin ferromagnetic metallic film disposed on a high- molecular film and subjecting the same to a high-pressure not air treatment. CONSTITUTION:After the lubricating agent is disposed by the solvent coating method on the thin ferromagnetic metallic film disposed on the thin ferromagnetic metallic film disposed on the high-molecular film, said agent is subjected to the high-pressure hot air treatment. The lubricating agent which is microscopically nonuniformly coated by the solvent coating method is greatly improved in the degree of orientation as if the molecular arrangement thereof is substantially analogous to the molecules arranged on the surface of the thin ferromagnetic metallic film when slowly formed by a Langmuir-Blodgett's technique (BL technique); in addition, the agent is oriented into the spacings among the fine crystals as well by the heating up effect of the pressure and hot air and in this way the improvement is promoted. The mass production of the magnetic recording medium having the good durability and weatherability at and under a high temp. and high humidity is thereby permitted.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of manufacturing a magnetic recording medium having a magnetic recording layer made of a ferromagnetic metal thin film suitable for high-density magnetic recording.

Conventional technology A magnetic recording medium whose magnetic recording layer is a ferromagnetic metal thin film, which is suitable for high-density magnetic recording, has a magnetic recording layer formed by electron beam evaporation,
After forming by sputtering method etc., a top coat layer is applied by solution coating method, vacuum evaporation method etc. and then processed to a predetermined size [for example, IEICE Magnetic Recording Study Group Materials, MR81-2 ( 1981), JP-A-57-2
Be 7 No. 189331, JP-A-57-150136.

JP-A-57-179948, JP-A-61-12662
No. 7, JP-A-61-11930, JP-A-61-151
No. 835, Japanese Unexamined Patent Publication No. 61-151837].

Recently, recognition of the importance of the top coat layer has particularly increased, and many proposals have been made regarding the material.

In particular, for the purpose of improving durability, diamond-like carbon film,
Plasma polymerized film, 5in2 sputtered film.

MOS, a laminated type of sputtered film and lubricant, is attracting attention.

Lubricant coatings are often performed using a wet solution coating method, which is better for mass production than organic vapor deposition methods, and this method is optimized by adjusting the combination of lubricant and solvent and drying conditions.

Problems to be Solved by the Invention However, with the above configuration, when used repeatedly in a high temperature and humid environment, the lubricant decreases and there is no sufficient lubricating action, resulting in increased noise and decreased stealth characteristics. Because of these problems, 3 bar/ improvement was desired. The present invention has been made in view of the above-mentioned circumstances, and provides a manufacturing method capable of obtaining a magnetic recording medium with good durability.

Means for Solving the Problems In order to solve the above-mentioned problems, the method for manufacturing a magnetic recording medium of the present invention involves distributing a lubricant on a ferromagnetic metal thin film disposed on a polymer film by a solution coating method. After that, it is treated with high-pressure hot air.

Operation The method for producing a magnetic recording medium of the present invention has the above-described structure, so that when the lubricant, which is microscopically non-uniformly applied by the solution coating method, is slowly formed by the Langmuir-Projet method, the ferromagnetic metal The degree of orientation is significantly improved so that it is substantially similar to the molecular arrangement oriented on the surface of the thin film, and the improvement is also achieved because the gaps between the microcrystals are also oriented by pressure and the heating action of hot air. It is thought that it will move forward.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. The figure shows a high-pressure hot air treatment device used to carry out the present invention. In the figure, reference numeral 1 indicates a treated substrate, in which a ferromagnetic metal thin film is placed on a polymer film, and a lubricant is placed on top of the ferromagnetic metal thin film using a solution coating method. Polyethylene terephthalate, polyethylene naphthalate, polyether sulfone, polyphenylene sulfide, polyimide, polyamideimide, polycarbonate, etc. are suitable for the polymer film, and electron beam evaporation,
Go-Ti, Go-Ta formed by ion blating method, sputtering method, etc.

Co-Mg, Go-Mo, Go-Or,
Go-Cu, Fe-Ag, Go-
Fe, Go-Ni.

Go-0, Co-Cr-Nb, Go-
A thin film such as Ni-0 is used. The solution application method is toluene.

Methyl ethyl ketone, methyl imbutyl ketone.

A lubricant is added to a solvent such as ethyl ether or Daiflon, and then applied using a reverse roll coater, bar coater, etc., and dried.The lubricant includes fatty acids, silicone oil, fluorine oil, fatty e-varnish, 5 bar/chill, and fluid. Paraffin, surfactants, etc. can be used. 2 is a delivery shaft, 3 is a winding shaft, 4 is a coating head schematically shown, and 5 is a drying oven, which is preferably of an air float type. 6 is a high pressure hot air treatment tank, 7 is a high pressure hot air generator, and 8 free rollers. For blowing high-pressure hot air, it is preferable to use a nozzle provided with a large number of fine holes, and the direction of blowing the hot air is preferably selected to be diagonal to the substrate to be treated and approximately parallel to the direction of movement of the substrate.

Hot air can be selected by optimizing the conditions appropriately depending on the type of lubricant, and the effect is almost saturated regardless of the material if the pressure is 1°atm or more, so it is recommended to use hot air from 10atm to 10atm. It is sufficient to design at 15 atmospheres.

Examples will be more specifically described in comparison with comparative examples. The minimum angle of incidence is 36 along a cylindrical can with a diameter of 1 m on a polyethylene terephthalate film with a thickness of 1011 m.
A Co-Ni film (Ni, 20wt) was deposited to a thickness of 0.13μ by oblique evaporation in oxygen at 1×10 (Torr).
After applying 9 m of Verobenhenic acid dissolved in toluene on it, and treating it with hot air at 13 atm and 83°C for 3 seconds, tape
9/n? Tape B is the coated material that is not treated with hot air.
And so.

On polyphenylene sulfide with a thickness of 10 μm, T-02 fine particles with a diameter of 100 were placed 10/(μm)2,
On top of that, Co-Cr (Cr2O, 5wt.
%) A perpendicular magnetization film with a thickness of 0.15 μm was formed, and 10.5 μm of perfluorooctanoic acid in methyl ethyl ketone was formed on it.
9/yrf and treated with hot air at 15 atm and 96°C for 4 seconds.
Tape D was prepared by simply applying mg ~.

After tapes A to D were run 100 times on a commercially available 8 mm VTR at 45 DEG C. and 85 RH, the signal-to-noise ratio (S/N) of the luminance signal was examined for changes with respect to the initial state. Tape A, C
were both 0 (dB), but tape B was -3, 3 ((
iB), tape D was -4.6 (dB). or,
60°C 85 section RH 4 pieces 7 Hey After storage for a month, dropout at 20'060φRH (15
(μsec, −16 dB or more) was examined as a ratio to the initial value. Tape A was 1.9 times larger, Tape B was 18.7 times larger, Tape C was 1.2 times larger, and Tape D was 21.2 times larger.

Effects of the Invention As described above, according to the present invention, there is an excellent effect that magnetic recording media having good durability under high temperature and high humidity and good weather resistance can be manufactured in large quantities.

[Brief explanation of the drawing]

The figure is a diagram illustrating a main part of an example of a high-pressure hot air treatment apparatus used in carrying out the present invention. 1... Processing substrate, 4... Coating head, 6
...High pressure hot air treatment tank, ...High pressure hot air generator. Name of agent: Patent attorney Toshio Nakao and 1 other person1-
Genkori Rito 4 --- Gola Infirmary Throat 6 -- Iya A side skin processing chair '7' ---q Departing daytime

Claims (1)

[Claims] A method for producing a magnetic recording medium, which comprises disposing a lubricant by a solution coating method on a ferromagnetic metal thin film disposed on a polymer film, and then subjecting it to high-pressure hot air treatment.