JPS63184910A - Magnetic recording medium - Google Patents

Abstract

PURPOSE:To obtain a good envelope and to miniaturize a magnetic recording system by disposing a thin ferromagnetic metallic film to one face of a high- polymer film and disposing a thin nonmagnetic film to the other face thereof. CONSTITUTION:Ruggedness for decreasing the friction of a magnetic recording medium is formed by under coating layers 10, 11 on the high-polymer film 9. The thin ferromagnetic metallic film 12 is formed thereon by an electron beam vapor deposition, sputtering method, etc. The thin nonmagnetic film 13 having a Young's modulus E2 which is >=1.5E1 when the Young's modulus of the film 12 is designated as E1 is then formed on the opposite side. Three- dimensional tight contact is, therefore, easily obtd. and the effect of tension is decreased when a magnetic head contacts the magnetic recording medium. The good tight contact state is thereby assured and the envelope is obtd. in a good state even if the ring of rotation is diminished and the winding angle increases.

Description

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

2. Description of the Related Art Techniques for recording and reproducing audio and images using a helical scanning method using a rotating magnetic head have a higher recording density than other magnetic recording methods. 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 diagonal vapor-deposited film with a knee of 0 is seen as promising [For example, foreign journal IEEE Transactions on Magnetics (IEEE TRANSAG)
TIONSON MAGNET C3) Vol MA
G-21, No-3, P, P.

1217-1220 (198,5)).

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 from 0.06 μm to 0.06 μm formed by electron beam evaporation method, high frequency sputtering method, etc.
A magnetic recording layer consisting of a ferromagnetic metal thin film of about 371 m.
Reference numeral 3 denotes a protective lubricant layer which can be appropriately selected from a number of proposals, such as a layered layer of an amorphous carbon film and a fluorine oil. 4 is the back coat layer,
This is a coating layer made of a resin containing fillers, lubricants, etc. to aid running properties.

JP-A-61-151835, JP-A-61-187
Publication No. 122, etc.].

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 1/1 that of the conventional coated magnetic layer.
0 and the Young's modulus of the magnetic recording layer is more than 10 times larger, so it is thought that the total thickness can be made thinner, but when aiming for practical use over a wide temperature range, it becomes a bimetallic structure. Therefore, a tape structure having vapor deposited layers on both sides has been proposed [JP-A-61-110343].

FIG. 3 is an example of an enlarged cross-sectional view of a double-sided vapor-deposited magnetic tape. In FIG. 3, reference numeral 6 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; in the case of double-sided access, it is made of a ferromagnetic metal thin film; in the case of single-sided access, it is made of SiO, 5i02, Al2O5, MgF2
8 is a protective lubricant film, which is formed by a method such as reactive vapor deposition or high frequency sputtering.

Problems to be Solved by the Invention However, the double-sided vapor-deposited magnetic tape has a total thickness of 8 μm.
If the temperature is below, the temperature change in the curl state can be reduced, but if the diameter of the rotating cylinder is made smaller and the wavelength is made shorter in a system where recording and reproduction is performed by wrapping the magnetic head around a rotating magnetic head at a larger angle, Improvements have been desired since the envelope cannot maintain a good condition over the entire wrapping angle.

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 magnetic recording medium with a thin overall thickness that enables recording and reproduction of short wavelengths with smaller equipment.

Means for Solving the Problems In order to solve the above problems, the magnetic recording medium of the present invention includes a ferromagnetic metal thin film having a Young's modulus of E1 on one side of the polymer film, and a Young's modulus on the other side of the polymer film. Rate E2 is 1
．． 511 or more nonmagnetic thin films are arranged.

Effect The magnetic recording medium of the present invention has the above-described structure, so that when the magnetic head and the magnetic recording medium come into contact, they are likely to come into close contact three-dimensionally, so that the influence of the tensicon can be reduced, and the rotational spooling can be reduced, making it easier to wrap the magnetic recording medium. Even if the angle becomes larger,
Good adhesion can be ensured and the envelope can be obtained in good condition.

Embodiments Embodiments of the present invention will be described below with reference to drawings ``kE''. Fig. 1 is an enlarged cross-sectional view of a magnetic recording medium of the present invention, and in Fig. 1, 9 is a polyethylene terephthalate film having a thickness of 7.6 μm to 3 μm. For polymer films such as HolJ ethylene naphthalate, polyethylene naphthalate, polyvinylene sulfide, polysulfone, polyamideimide, and polyimide, the Young's modulus should normally be within the range that can be stretched and strengthened for each material. The undercoat layer forms unevenness in order to reduce the friction of the magnetic recording medium, and is earthworm-shaped.

The particles are appropriately selected from granules, combinations thereof, etc., and fine particles include A7!205, 5i02, CaCO3, Ba
SO4.

TiO2, Fe2O2, CrO2, carbon, etc., polyester balls, polyethylene balls, etc. are used.

12 is Go-Ni, Go-ye, Fe-Ag
, Go-Ta.

Go-Ti, Go-Or, Go-Or-Nb
, Go-Cr-P.

A ferromagnetic metal thin film such as Go-Ni-0, formed by electron beam evaporation method, sputtering method, etc., with a diameter of 0.06
In the range from μm to 0.2 μm, if Young's modulus 'x E is 1, then El is 8,000 to 16,000 (kg/y
i) C1 range (most things fall into C. 13 is the Young's modulus of the ferromagnetic metal thin film kE-+, which is 1.6Ej
It is composed of a non-magnetic thin film with a Young's modulus Kze of
E1 to 3K.

It should be configured within the range of . Of course, it may be 3E or higher, but this will cause problems such as extremely low productivity in the manufacturing process, so the range should be from 1.6E1 to 21. It is preferable to configure it within the range of . It is not clear why head touch becomes unstable below 1.51j, but experimentally a criticality clearly exists.

Reference numeral 14 denotes a lubricant, which is appropriately selected from fatty acids, fatty acid amides, fluorine compounds, etc., and may be laminated with a plasma polymerized film or an amorphous carbon film. In the following, the superiority of this example will be explained in more detail in comparison with a comparative example. A film with a diameter of 1
8102 fine particles of 00 people were dispersed and fixed in polyester resin at a density of 16 particles/(μm)2, and then placed along a cylindrical can with a diameter of 1 m in an oxygen atmosphere of 5.3 x 1O-5 (Torr). Go-Ni (Ni
, 20 wt%) was electron beam evaporated to give 0.13
A μm Go-Ni-0 film was arranged. This Go-Ni-0
The film has a coercive force of 120o (Oe) and a Young's modulus of E1, 9,
It was 200 (kg/i).

Bei was deposited on the opposite side of the Go-Ni-0 film by ion beam deposition. At that time, the substrate temperature ranged from 2°C to 100°C, and the ion density totaled 10 (μA/c4
) to 320 (μA/c).
Young's modulus of 171m Be thin film Ez'k 9,500
(kg/J.

12.600 Ckg/mff1], 14. ooooo
[kg/mff1:] , 17.8o.

(kg/mA) were made into tapes. The lubricant was a vapor-deposited film of stearic acid by 40 people. Regarding these four types, 3.8 mi! After slitting to J width, a gap length of 0.
Equipped with a 14 μm ferrite head, has two winding angles of 200 degrees and 290 degrees, and has a recording wavelength of 0.6 μm.
= 2 were recorded and the flatness ratio of the envelope of the reproduced waveform was compared. The results are summarized in a table.

Effects of the Invention As described above, according to the present invention, it is possible to obtain a good envelope even when recording and reproducing short wavelengths by reducing the diameter of the rotating cylinder, and it is possible to miniaturize the magnetic recording system. It has excellent effects.

[Brief explanation of the drawing]

FIG. 1 is an enlarged sectional view of an example of the magnetic recording medium 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 (Young's modulus is +), 13...Nonmagnetic thin film (Young's modulus 1.
61, above). Name of agent: Patent attorney Toshio Nakao and 1 other person9-
Squeeze number film (〒ink rate/,,5 Ez or more) Figure 2 Figure 3

Claims (1)

[Claims] A ferromagnetic metal thin film with a Young's modulus of E_1 is disposed on one side of the polymer film, and a Young's modulus of K_2 is placed on the other side of the polymer film.
A magnetic recording medium characterized by disposing a 1.5K_1 thin film.