JPH0227518A - magnetic recording medium - Google Patents

Abstract

PURPOSE:To stabilize a traveling property in repetitive use and to prevent the deterioration of image quality by jitters by laminating a thin ferromagnetic metallic film, diamond-like carbon film and lubricating agent layers to one surface of a high-polymer film and disposing a porous carbon film to another surface. CONSTITUTION:The thin ferromagnetic metallic film 12, the diamond-like carbon film 13 and the lubricating agent layers 15A, 15B are laminated on one surface of the high-polymer film 9 and the porous carbon film 14 is disposed on another surface. Both the surfaces are carbon if the recording medium is constituted in such a manner. The lubricating agents are then moved by transfer so as to exist always at an equal amt. on the surfaces when the high-polymer film is wound and, therefore, the property to retain the lubricating effect is improved. Since the rear surface consists of the porous carbon, the total adsorption amt. of the lubricating agents is increased and the property to retain the lubricating effect is improved. The traveling property in the repetitive use is improved and the degradation in the image quality by the jitters is prevented in this way.

Description

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

2. Description of the Related Art Techniques for recording and reproducing a single audio image using a helical scanning method using a rotating magnetic head have a higher recording density than other magnetic recording techniques. Therefore, in order to further shorten the wavelength in the future, a magnetic recording medium with a new configuration will be required. A vapor-deposited tape with a -0 obliquely vapor-deposited film is considered promising [for example.

Foreign journal, IEEE TRAMP KUSHI3NS
On Magnetics (11[ICTRANSACTI
ONS ON MAGNKTIC5) 701,
MAG-21, No-3, P, P, 1217-12
20 (1985)).

Figure 2 is an enlarged cross-sectional view of an example of a vapor deposition tape.
A polymer film such as a polyethylene terephthalate film, which is provided with an undercoat layer to provide unevenness if necessary, is also used. 2 is 0.05 μl to 0.05 μl formed by electron beam evaporation method, high frequency sputtering method, etc.
A magnetic recording layer made of a ferromagnetic metal thin film of about 3 μm.
The protective lubricating layer may be an amorphous carbon film and a laminated ring of fluorine oil, which can be appropriately selected from among many proposals. 4 is the back coat layer,
It is a coating layer made of resin containing fillers, lubricants, etc. to aid running properties [Japanese Patent Publication No. 66-23208,
JP-A-59-41418, JP-A-61-1518
No. 35, JP-A-61-187122].

Another feature of magnetic tape is that it can have a large volumetric recording density, and as a means of long-term recording, the trend toward thinner tapes is also important.From this point of view, vapor-deposited tapes are advantageous for thinning and are difficult to develop. The current situation is that progress is being made.

It is true that the magnetic recording layer is thinner than a conventional coated magnetic layer, and the Young's modulus of the magnetic recording layer is more than 10 times greater, so it is thought that the total thickness can be made thinner, but it can be used over a wide temperature range. When considering practical application in the field, the disadvantages of the bimetallic structure become obvious, so a tape structure with vapor-deposited layers on both sides has also been proposed [JP-A-61-1
Publication No. 10343].

FIG. 3 is an example of an enlarged sectional view of a double-sided vapor-deposited magnetic tape. In FIG. 3, reference numeral 5 denotes a polymer film, such as a polyethylene terephthalate film having earthworm-like irregularities on both sides. 6 is a magnetic recording layer made of a ferromagnetic metal thin film such as a perpendicularly magnetized film or an obliquely deposited film; 7 is made of a ferromagnetic metal thin film in the case of a double-sided access type; and 1 in the case of single-sided access.

A non-magnetic thin film of SiO, SiO2, Ag2O3, MgF2, etc. is formed by a method such as 1 reactive vapor deposition or high frequency sputtering. 8 is a protective lubricating film.

Problems to be Solved by the Invention However, in the above configuration, the total thickness is 10μ or less,
When applied to business purposes, durability is insufficient and image quality deterioration due to jitter is an issue, especially in light of the recent demands for high-quality recording technology.

Improvement was desired. The present invention has been made in view of the above-mentioned circumstances, and it is an object of the present invention to provide a thin magnetic tape whose running properties are stabilized even after repeated use and which does not cause deterioration in image quality due to jitter.

Means for Solving the Problems In order to solve the above-mentioned problems, the magnetic recording medium of the present invention comprises:
A ferromagnetic metal thin film, a diamond-like carbon film, and a lubricant layer are laminated on one side of a polymer film, and a porous carbon film is placed on the other side.

action The magnetic recording medium of the present invention has the above-described configuration.

Both sides are carbonaceous, and when the lubricant is wound twice, the lubricant is transferred by transfer so that it is always present on the surface, improving the sustainability of the lubricating action. As a result, the total amount of lubricant adsorbed increases, and the
The total amount can be increased without causing the stiffness phenomenon that makes it impossible to run, and the sustainability is greatly improved.

EXAMPLE An example of the present invention will be described below with reference to the drawings. FIG. 1 is an enlarged sectional view of a magnetic recording medium according to an embodiment of the present invention. In FIG. 1, 9 indicates polyethylene terephthalate, polyethylene naphthalate, or polyether ether ketone having a thickness of 9 tones or less.

10. Polymer films such as polyphenylene sulfide, polyether sulfone, polyamide, polyimide, etc.
11 is a worm-shaped undercoat layer made of water-soluble polymer, or 5
in2. An undercoat layer containing fine particles such as TiO2, CaCO3゜ZnO, and polyethylene spheres, and 12 is Go, Go
-Or, Go-0, Go-Ni.

Go-Fe, Go-Ta, Go-Mo, Co-W
, Go-Nd.

A ferromagnetic metal thin film such as co-cr-gb or Go-Ni-0 is preferably used, and the thickness is preferably in the range of SOO to 3000.

It may have a multilayer structure, and can be formed by electron beam evaporation, ion blating, sputtering, or the like. Reference numeral 13 is a diamond-like carbon thin film prepared by known methods such as sputtering method and ion beam deposition method [Electronic Ceramics September 1987 issue,
Although a diamond thin film may be used, industrially, a diamond-like hard carbon film is suitable because the film forming rate is low. 14 is a porous carbon thin film, 10 to 1o-'
Either ion derating the carbon in the range of
It is obtained by sputtering in the range of ~0.4 Torr, and the film thickness is 10 to 24 degrees.

A suitable surface area is o, 13 to o, 7Cnf7f/). 16 is divided into 15mm and 15B with lubricant and placed on both sides, and even after manufacturing, it is used in tape form to maintain an equilibrium state by transfer.
1 fatty acid ester-fluorocarboxylic acid.

Perfluoropolyether or the like is applied by a solution coating method, a vacuum evaporation method, or the like.

Examples of the present invention will be described in more detail below in comparison with comparative examples.

Example-1 On one side of a polyethylene terephthalate film with a JF of 18.8 μm, 16 particles of Eu2O3 with a diameter of 90 μm were coated as an undercoat layer with a density of 40 μm on the other side.
E
U2O, placed along a cylindrical can with a diameter of 1 m on the surface with fine particles, minimum incident angle 65 degrees, oxygen partial pressure 4 x 10
Electron beam evaporation of CO was performed at (Torr).

A C0-0 film was formed at 120 OA, and methangane was applied on it at 0.1 (Torr) 13.56 (MHz) B
80 diamond-like hard carbon films were placed using a method that turned it into plasma using oo (w) and accelerated it with a bias of 300 (V).

Target carbon on the other side: +”
yo, 2 (Torr), 20 (KHz),
900 (W).

By the sputtering method with the substrate temperature at -16°C,
Film thickness 1400A, surface area o, 4Crrl/f! ), perfluorostearic acid was vacuum-deposited by 50 people using a vacuum evaporation method, and the winding shaft was kept at an elevated temperature (60'Q, 4 hours) while being wound in vacuum.

Vacuum deposition by 50 people and temperature raising and holding were repeated three times.

A total of 200 people were vapor-deposited and made into 8mm wide magnetic tape.

It was wound 130m into an 8mm cassette.

Example-2 In Example-1, Co-TL (Go:
81wt%) perpendicular magnetization film 1200A was disposed by high frequency sputtering method, and the porous carbon film had a surface area of 1,5677/
The magnetic tape was made to have a film thickness of 1,500 people, and instead of perfluorostearic acid, perfluoromyristic acid and stearic acid amide were alternately vapor-deposited (enough for 200 people) to form an 8 mm wide magnetic tape, which was wound 130 m into an 8 mm cassette.

Comparative Example 1 In Example 1, an 8 mm tape was prototyped in which the porous carbon film was replaced with a 1000 mm thick diamond thin film.

Comparative Example-2 A porous carbon film with a surface area of 0.8 Bd/f in Example-2 was
The structure was the same except for 400 people.

Comparative Example 3 An 8 mm tape having the same configuration as Example 1 except that the surface area of the porous carbon membrane was set to 0.1 d/f was fabricated.

Each of the above-mentioned tapes was modified to a high band specification in an 8-millimeter video tape recorded at 5°C, 80% RH, and the tapes were repeatedly played back every 8 hours to compare their performances. Play 6
The test was repeated 0 times, and the maximum value of output reduction and the number of passes at which jitter was clearly observed by visual inspection of the image were compared.

(Hereinafter referred to as Kinshiro) As can be seen from the above results, 0.13vf/'j or more is preferable in order to increase the total amount of lubricant and to realize a system without the occurrence of stiffness or jitter. The amount determined by the required lubricant storage capacity of the carbon film is 0.7vl/
The preferable value of 9 or less is a critical value determined because if the carbon film becomes more porous, the carbon film is likely to be chipped, contaminating the refill head and making the output unstable.

Effects of the Invention As described above, the present invention has the excellent effect that it is possible to obtain a magnetic recording medium with good runnability, which does not decrease in output even in a high humidity environment for short wavelength recording.

[Brief explanation of the drawing]

FIG. 1 is an enlarged sectional view of a magnetic recording medium according to an embodiment of the present invention, and FIGS. 2 and 3 are enlarged sectional views of a conventional magnetic recording medium. 9...Polymer film, 10.11...
・Undercoat layer, 12...Ferromagnetic metal thin film, 13...
...Diamond-like carbon film, 14... Porous carbon film, 16m. 15B...Lubricant. Name of agent: Patent attorney Shigetaka Awano and one other person?
- Ilmu Iki 15# - Lubrication

Claims (1)

[Claims] A magnetic recording medium characterized in that a ferromagnetic metal thin film, a diamond-like carbon film, and an oil lubricant layer are laminated on one side of a polymer film, and a porous carbon film is arranged on the other side.