JPS6366720A - Magnetic recording medium and its production - Google Patents

Abstract

PURPOSE:To thoroughly decrease coefft. of friction and to improve runnability and durability by forming an underlying layer dispersed and deposited with fine particles consisting of a metal or an inorg. compd. or org. high-polymer compd. to an island shape on a substrate, then providing a thin ferromagnetic metallic film layer consisting of metals or the alloy thereof onto said layer. CONSTITUTION:Metals such as 'Permalloy(R)', aluminum and copper or the alloys thereof or inorg. compds. such as silicon, C, B, and SiC and org. high- polymer compd. are adequately used as the material for forming the underlying layer 21. The underlying layer 21 is formed by dispersing and depositing the fine particles consisting of the metal or inorg. compd. or the org. high-polymer compd. having 50-500Angstrom particle size to the island shape on the substrate, and thereafter, the thin ferromagnetic metallic film layer 22 is formed thereon, then the thin ferromagnetic metallic film layer 22 is formed along the ruggedness of the fine particles and the ruggedness is formed on the surface of the thin ferromagnetic metallic film layer 22. The real contact area at the time of sliding with a magnetic head, etc., is thereby decreased and the coefft. of friction is thoroughly decreased, by which the runnability is satisfactorily improved and the durability is additionally upgraded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic recording medium having a ferromagnetic metal thin film layer as a magnetic recording layer and a method for manufacturing the same, and more specifically relates to a magnetic recording medium having a small coefficient of friction, good running performance and durability. The present invention relates to the above-mentioned magnetic recording medium having excellent properties and a method for manufacturing the same.

[Conventional technology]

A magnetic recording medium whose magnetic recording layer is a ferromagnetic metal thin film layer is
Usually, metals or their alloys are deposited on a base film by vacuum evaporation, sputtering, etc., and have characteristics suitable for high-density recording. It has poor performance and is susceptible to wear and damage.

For this reason, various protective layers have been conventionally provided on the ferromagnetic metal thin film layer to improve running performance and durability. There are also practices such as making people wear clothes. (
JP-A-53'-88704, JP-A-58-94130
(No.) [Problem to be solved by the invention] However, these 18I lubricant layers have a problem in contact with the magnetic head.
Due to J contact, it may peel off and break in a relatively short period of time, causing head clogging, and running performance and durability have not yet been sufficiently improved.

[Means for solving problems]

This invention was made as a result of various studies in view of the current situation. First, a base layer is formed on a substrate by dispersing and precipitating fine particles made of a metal, an inorganic compound, or an organic polymer compound in the form of islands. By providing a ferromagnetic metal N film layer made of metals or their alloys on top of this, unevenness is formed on the surface of the ferromagnetic metal thin film layer due to the influence of the fine particles dispersed and precipitated in the form of islands, making it difficult to interact with magnetic heads, etc. The actual contact area during sliding is reduced, the coefficient of friction is sufficiently reduced, and running performance and durability are sufficiently improved.

In this invention, materials for forming the base layer formed by dispersing and precipitating fine particles in the form of islands on the substrate include permalloy, aluminum, copper, gold, nickel-chromium alloy, titanium,
Metals such as tungsten and β-tantalum or alloys thereof, or silicon, C, B5SiC, Si3 N4,
A1203% Sl 02 , T I C% W Cs
T I N % B N s T I B 2, Cr
Inorganic compounds such as B2 s ZrO2, fluorine resin, silicone resin, amide resin, imide resin, phenol resin, aniline resin, melamine resin, formalin resin, urea resin, furan resin, epoxy Organic polymer compounds such as resins are preferably used, and these metals, inorganic compounds, organic polymer compounds, etc. can be dispersed and deposited on the substrate by physical vapor deposition such as vacuum evaporation, sputtering, and ion blating. is,
A base layer is formed.

Such physical vapor deposition such as vacuum evaporation, sputtering, and ion blating is preferably performed in an inert gas, oxygen gas, nitrogen gas, or a mixed gas thereof, and the gas pressure of these gases is 1×10 It is preferably within the range of 5X10-2 to 5 Torr. If it is lower than 1X10-2, fine particles will not be formed and the film will become thinner, and if it is higher than 10 Torr, the fine particles will become too large and electromagnetic It has a negative effect on the conversion characteristics.

The fine particles made of metal, inorganic compound, or organic polymer compound dispersed and precipitated on the substrate in this way preferably have a particle size within the range of 50 to 500 particles,
If it is less than 50, it will not be possible to form good unevenness on the surface of the ferromagnetic metal thin film layer that is formed on top of the ferromagnetic metal thin film layer, and the coefficient of friction will not be sufficiently small. The unevenness on the surface of the metal thin film layer becomes too large, which adversely affects electromagnetic conversion characteristics.

In this way, fine particles made of a metal, inorganic compound, or organic polymer compound with a particle size of 50 to 500 are dispersed and precipitated in an island shape on the substrate to form a base layer, and then a ferromagnetic metal When the thin film layer is formed, a ferromagnetic metal thin film layer is formed along the irregularities of the fine particles, and due to the influence of these island-like fine particles, the surface of the ferromagnetic metal thin film layer has a center line average roughness of 0.001 tJ. m Ra to 0.
Asperities of the order of 008#mRa are formed. Therefore, the actual contact area during sliding with the magnetic head etc. is reduced, the coefficient of friction is sufficiently reduced, and the running performance is sufficiently improved.
Durability is further improved.

The material for forming the ferromagnetic metal thin film layer is Co, Fe5N.
i, Co-Ni alloy, Co-Cr alloy, Co-P alloy,
(:, ferromagnetic materials such as o-Ni-P alloy are used,
A ferromagnetic metal thin film layer made of these ferromagnetic materials is deposited on a substrate by means such as vacuum evaporation, ion blasting, sputtering, or plating.

In addition, as magnetic recording media, polyester film,
Various types of structures that come into sliding contact with magnetic heads, such as magnetic tapes based on synthetic resin films such as polyimide films, magnetic disks and magnetic drums based on disks and drums made of synthetic resin films, aluminum plates, glass plates, etc. includes.

〔Example〕

Next, embodiments of the invention will be described.

Example 1 Using a vacuum evaporation apparatus adjacent to the vacuum evaporation chamber shown in FIG. The cylindrical can is moved through a pair of upper and lower guide rolls 8, 8 disposed in a communication section with the guide roll 6 and the adjacent vacuum deposition chamber 7, and further through a guide roll 9 disposed within the vacuum deposition chamber 7. The take-up roll 1 is moved through the guide roll 11 while being in sliding contact with the lO.
I set it to wind up at 2. Next, Natsora vapor deposition chamber 2
Argon gas is introduced into the vacuum evaporation chamber 2 from the gas introduction pipework 3 attached to the cylindrical can 5, and the gas pressure is set to lX1O-Il--. Permalloy 15 was set and heated to evaporate, and island-shaped fine particles made of Permalloy having a particle diameter of 160 were dispersed and precipitated on polyester film 1 to form a base layer. Furthermore, oxygen gas is introduced from the gas introduction pipe 16 attached to the deposition chamber 7, the gas pressure is set to lXl0-5 torr, and cobalt- Nickel alloy (weight ratio, 80
:20) Set 18 and heat and evaporate to a thickness of 150.
A ferromagnetic metal consisting of a cobalt-nickel alloy
A t-film layer was formed. Thereafter, it is cut into a predetermined width, and as shown in FIG. 2, a base layer 2 made of dispersed and precipitated fine particles is formed.
Magnetic tape A was prepared by laminating ferromagnetic metal thin film layer 1 and ferromagnetic metal thin film layer 22 on polyester film 1. Reference numerals 19 and 20 in the figure are exhaust systems for reducing the pressure in vacuum deposition chambers 2 and 7, respectively.

Examples 2 to 7 In forming the base layer in Example 1, particles were formed on polyester film 1 in the same manner as in Example 1, except that the gas pressure of argon gas was variously changed as shown in Table 1 below. Magnetic tape A was prepared by dispersing and separating island-shaped permalloy fine particles having various diameters as shown in Table 1 below to form an underlayer, and further forming a ferromagnetic metal thin film layer.

Table 1 Comparative Example 1 A magnetic tape was produced in the same manner as in Example 1 except that the formation of the underlayer made of island-shaped fine particles was omitted.

Regarding the magnetic tapes obtained in each Example and each Comparative Example, the coefficient of friction was measured, and the still life at room temperature was measured using a still tester.

Table 2 below shows the results.

Table 2 [Effects of the Invention] As is clear from the above table, all of the magnetic tapes obtained by the present invention (Example Works to 7) had less friction than the magnetic tape obtained in Comparative Example 1. The coefficient is small and the normal temperature still life is long, which shows that according to the present invention, a magnetic recording medium with even better running properties and excellent durability can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view showing an example of a vacuum evaporation apparatus, and FIG. 2 is a partially enlarged sectional view of a magnetic tape obtained by the present invention. DESCRIPTION OF SYMBOLS 1... Polyester film (substrate), 21... Base layer, 22... Ferromagnetic metal thin film layer, A... Magnetic tape (magnetic recording medium) Patent applicant Hitachi Maxell, Ltd. Figure 2

Claims (1)

[Scope of Claims] 1. A base layer is formed on a substrate, in which fine particles made of a metal, an inorganic compound, or an organic polymer compound are dispersed and precipitated in an island shape, and a ferromagnetic layer made of a metal or an alloy thereof is formed on this base layer. A magnetic recording medium 2 characterized in that a metal thin film layer is provided and irregularities are formed on the surface of the ferromagnetic metal thin film layer, on a substrate in an inert gas, oxygen gas, nitrogen gas, or a mixed gas thereof, Gas pressure is 1×10
^-^ Under an atmosphere of 2 to 10 torr, a metal, an inorganic compound, or an organic polymer compound is physically vapor deposited to form a base layer in which fine particles of the metal, inorganic compound, or organic polymer compound are dispersed and precipitated in the form of islands. form, then
A method for manufacturing a magnetic recording medium, which comprises forming a ferromagnetic metal thin film layer made of metal or an alloy thereof thereon.