JPS61180921A - Vertically magnetized recording medium and its production - Google Patents

Abstract

PURPOSE:To obtain a two-sided double layer type vertically magnetized recording medium having excellent characteristics on its both sides, by forming a soft magnetic film on a supporter at 30-90 deg.C by a vapor deposition or sputtering process and also forming a vertically magnetized film on the soft magnetic film at >=90 deg.C by a vapor deposition or sputtering process. CONSTITUTION:The soft magnetic films are formed on both sides of a film type supporter by a vapor deposition or sputtering process while the supporter is heated up to 30-90 deg.C. Thus the surface of the supporter is covered almost entirely with a metallic film. then the supporter covered with the soft magnetic films on both sides is heated up to >=90 deg.C and at the same time a vertically magnetized film containing mainly Co and Cr is formed by a vapor deposition or sputtering process. Here it is desirable to use a continuous sputtering process to form said magnetized film with use of plural high-speed sputtering sources distributed at the circumference areas of plural cylindrical cans. Thus it is possible to obtain a two-sided double layer type vertically magnetized recording medium which have high Hc, isotropic electromagnetic characteristics, the same characteristics on both sides and excellent electromagnetic conversion characteristics respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic recording medium and a method of manufacturing the same, and more particularly to a double-sided double-layer perpendicular magnetization recording medium and a method of manufacturing the same.

[Prior art]

In recent years, a perpendicular magnetization recording method using a magnetic recording medium having an axis of easy magnetization in a direction perpendicular to the film surface of the recording medium has been proposed. This perpendicular magnetization recording method 1 can be said to be a method essentially suitable for high-density recording, since the demagnetizing field in the recording medium decreases as the recording density increases, and excellent reproduction output can be obtained.

In order to perform magnetic recording using such perpendicular magnetization recording method, a magnetic recording medium having an axis of easy magnetization in a direction perpendicular to the film surface of the recording medium is required. As such a perpendicular magnetic recording medium, one is known in which a Co-Cr alloy or the like is deposited on a support made of a non-magnetic material such as a polymeric material or a non-magnetic metal by a method such as stagnation. ing.

In addition, in order to improve the recording efficiency in perpendicular magnetization recording media, a high M1 ratio layer made of a soft magnetic material is used as an underlayer under the perpendicular magnetic recording layer made of the above-mentioned Co--Cr alloy film, for example. 2. Description of the Related Art A so-called two-layer perpendicular magnetic recording medium provided with a Noguichi Malloy (Ni-Fe alloy) film is known.

In addition, in flexible disks using the perpendicular magnetization recording method, so-called double-sided double-layer perpendicular magnetic recording media, in which the double-layer perpendicular magnetic recording medium is formed on both sides of a support, have a higher recording capacity. It is excellent because it has large curls and is easy to improve curls.

When such a double-sided double-layer type perpendicular magnetization recording medium is continuously formed on a film-like support, it is conventionally produced using an apparatus as shown in FIG.

That is, the film-like support 5 discharged from the support delivery roll 3 disposed inside the vacuum chamber passes through the cooling can 2 and is wound up by the support take-up roll 4. On the other hand, a malloy alloy target 6 and a Co-
By using the Cr alloy target 7, a two-layer film consisting of a Semalloy film and a Co--Cr film is formed on one surface of the film-like support.

Subsequently, the vacuum chamber is returned to atmospheric pressure, the film-like support is turned over, and the layer is re-evacuated, after which a two-layer film is formed on the other surface in the same manner as in Method 1.

As another improved method, a method is known in which a double-sided double-layer film is formed using a double-sided sputtering apparatus as shown in FIG. 6, for example.

According to this method, first, the malloy alloy target 6
1 and Co-Cr alloy target 32 to form a two-layer film on one side of the film-like support, and then a permalloy alloy target 66 and Co-Cr alloy target 34 to form a two-layer film on the other side. I can do it.

[Problem that the invention seeks to solve]

When a double-sided dual-layer perpendicular magnetization recording medium is created using a winding type continuous stream or R-tutter device as shown in Figs. 2 and 6, tension is usually applied in one direction to the film-like support. The magnetostatic properties of the resulting No. 9-Malloy film are not isotropic, but rather a film in which magnetic anisotropy occurs within the plane of the film and the magnetostatic properties such as magnetic permeability vary depending on the direction inside the support. Therefore, for example, when a floppy disk is punched out and recorded and reproduced, there is a problem that the reproduction output fluctuates in the circumferential direction.

On the other hand, Co has a high coercive force in the vertical direction, that is, Hc (vertical).
- In order to form a double-sided double-layer perpendicular magnetization recording medium having a Cr film using a high-speed sputtering method, for example, to form a DC magnetron turf, the temperature of the support during sputtering of the Co-Cr film is generally high. is desirable.

However, in a double-sided layered perpendicular magnetization recording medium prepared on a film-like support made of a polymeric material, etc., the surface properties of the film-like support may deteriorate due to heating and temperature rise of the film-like support. , a decrease in the perpendicular orientation of the perpendicularly magnetized film, or differences in front and back surface properties, perpendicular orientation, He (vertical), etc. may result in deterioration or variation in recording and reproducing characteristics. , There was a large angle W4''''c & from the characteristics and production.

For this reason, we have developed a double-sided perpendicular magnetization recording medium that has the same VCC characteristics on both sides of a film-like support made of a polymeric material, etc., and has excellent properties as a perpendicular magnetization recording medium, and such a recording medium at high speed. In addition, a continuous manufacturing method was desired.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a double-sided double-layer perpendicular magnetization recording medium that eliminates the above-mentioned conventional drawbacks and has excellent characteristics on both the front and back sides, and a method for manufacturing the same.

Another object of the present invention is to provide a double-sided double-layer thin-film perpendicular magnetic recording medium that exhibits significantly less variation in playback output within the same track in the circumferential direction, especially when punched as a floppy disk, and a continuous manufacturing method thereof. It's about doing.

[Means for solving problems]

As a result of various studies, the present inventors have found that the above object can be achieved by the present invention described below.

That is, the present invention provides a perpendicularly magnetized recording medium having a soft magnetic film and a perpendicularly magnetized film mainly composed of Co and Cr on both sides of a film-like support, in which the soft magnetic film is disposed on the support at 30° C.
The perpendicular magnetization film is formed by vapor deposition or sputtering at a temperature of 90C to 90C, and is characterized in that the perpendicular magnetization film is provided on a soft magnetic film by vapor deposition or sputtering at a temperature of 90C or higher. There is a perpendicular magnetization recording medium 't%.

In addition, in the present invention, a soft magnetic film is first deposited on both sides of the film support while heating the film support to 60 to 90C.
Alternatively, the surface of the film-like support is almost completely coated with a metal film by forming the film-like support with a metal film, and then the film-like support coated with both sides of the soft magnetic film is coated with a metal film for 90 minutes.
There is a method for producing a perpendicular magnetic recording medium characterized by forming a perpendicularly magnetized film mainly composed of Co and Cr by vapor deposition or sintering method without heating the material to a temperature higher than C.

The film-like support used in the present invention can be applied to polymeric materials such as polyethylene terephthalate (PET), polyimide, polyamide, polyphenylene sulfide, polyethersulfone, and polysulfone. Fuori near 200C! It has a particularly remarkable effect on materials that precipitate mer or emit a large amount of gas. It can also be applied to a support having a base layer.

In addition, the support is previously subjected to pretreatment such as being held in a vacuum, heat treated, or glow discharge treatment,
It is desirable to reduce the emission of impurity gases from the surface and interior of the support.

Materials for the soft magnetic film include N1-re, Ni-Fe-M
o, Ni-Fe-Mo-Cu and other so-called Nozo-WO alloys, Fj, Fe-Al-8i, Fe-Ni-04
・Fe-Ti, Ni-Fe-Cn-Cr-Mn,
Fe-8i-B, Fe-B-C, Fe-AJ, Co
-V-Fe, Co-Ta, Co-Zr, Co
-Nb-Zr, Co-Ti, Co-Nb-Ta
, Co-Ni-Zr, Fe-Ni-P, Fe-P
, Fe-Co-Zr and other alloys are used.

The film thickness needs to be sufficient to suppress oligomer precipitation and impurity gas release from the film support, and is 0.
．． The thickness is selected to be approximately 0.06 to 5 microns. In order to obtain good perpendicular magnetization recording and reproducing characteristics, a thickness of approximately 0.1 to 1 micron is particularly desirable.

For the perpendicularly magnetized film, the axis of easy magnetization must be oriented in a direction almost perpendicular to the surface of the support. material is preferred.

The film thickness is selected to be about 0.06 to 5 microns, but preferably about 0.05 to 1 micron.

As the film forming means, vapor deposition, sputtering, etc. can be used, but it is preferable to use the so-called continuous sputtering method, which has a plurality of high-speed sputtering sources arranged around a plurality of cylindrical cans.

Various high speed sputter sources can be used as the sputter source.

The temperature of the cylindrical can is preferably 3 oc or more when forming a hard magnetic film such as a permalloy film to prevent magnetic anisotropy in the plane of the hard magnetic film from occurring.

On the other hand, if the can temperature is too high, gas release from the support, precipitation of oligomers, etc. will occur, so a temperature of 90C or lower is undesirable.

In order to particularly reduce magnetic anisotropy and film surface irregularities,
45-65G is particularly desirable. On the other hand, when forming a Co-Cr film, it is desirable to heat the cylindrical can to a temperature of 90°C or higher to obtain the desired Hc (vertical), and to obtain a perpendicular magnetization film of Hc (vertical), K is , 120°C or higher is particularly desirable.

In addition, the double-sided double-layer perpendicular magnetization medium of the present invention has a hard magnetic high permeability layer and a perpendicular magnetization film layer, and in addition to these, an underlayer, an intermediate layer, an overcoat layer, etc. may be added as necessary. May contain.

Hereinafter, the present invention will be explained using comparative examples and comparative examples.

Comparative Example A double-sided double-layer perpendicularly magnetized medium was prepared using a double-sided continuous sputtering apparatus shown in FIG.

50 micron thick rolled PET film delivery shaft 7
1, intermediate rollers 75 to 82, and cylindrical cans 72, 7! Winding shaft 74VcI through l! -I gave a kick so that it would be taken. The vacuum chamber is the delivery chamber 51. Sufu 9 Tutter Room 52,
The winding chamber 530 is roughly divided into three, and each chamber has partition walls 54 * 55
Each room has exhaust systems 56, 57 and 58, respectively.
It was evacuated by 59.

In the sputtering room, there is a permalator gelatin (Ni78.5).
- DC planar magnetron type Sufu9Takan-rq1. q3 and Co
- DC planar magnetron type sputter cutter with Cr target (Co82-Cr18 weight f%)
cp2. qa was established.

The interior of the sputtering chamber of such a sputtering device is 1×10(-
6) After evacuation to a pressure of torr or less, Ar gas is introduced from the gas introduction system 60, and approximately 6×10(-5) to
maintained at rr. A sputter cutter 19 is first applied to the PET film sent out from the delivery shaft 71 at a conveyance speed of 40 mm/min at the position of the can 72 set at a constant temperature.
1, a single malloy film was formed on one side (0 side) of K approximately 500 OA. Next, Can 7 was set to the same temperature.
At the 6th place b-, a sputter cathode 96 is used to form a Noso Malloy film on the other side (first side) with a thickness of about 5000A,
It was wound up on a winding shaft 74. Here, the temperature of the can is 15
, 30°C, 60°C, 90°C, and 120°C.

PET coated with permalloy film on both sides in this way
The film is conveyed in the reverse direction again and is heated by the sputter cathode 94 at the position of the can 73 set at a constant temperature.
A Co-Cr film of about 270 OA is formed on the surface, and then a Co-Cr film of about 270 OA is formed on the zero surface using the sputter cathode 92 at the position of the can 72 set at the same temperature, and then wound around the delivery shaft 71. Ta. Here, the temperature of the can is
30, 60.

Five levels were selected: 90, 120, and 150°C.

Co-
Can temperature of Cr film and obtained Co-
The relationship with the Hc (vertical) value of the Cr film is shown in FIG. Although the Hc (vertical) value of the Co--Cr film differs slightly depending on the conditions for forming the permalloy film, data is shown here for a typical sample, for example, a permalloy film formed at a can temperature of 60°C.

On the other hand, the can temperature during permalloy film sputtering and the stability in the circumferential direction of the reproduction output when the obtained double-sided double-layer perpendicular magnetization film is punched out on a 525-inch floppy disk and recorded and reproduced are Vmax /Vmin (see FIG. 6) is shown in FIG.

Further, FIG. 6 shows the envelope of the recording/reproducing output on the floppy disk.

Comparative example Using the same snow-cutter device as in the comparative example.

A comparative experiment was conducted.

Delivery shaft 71 made of rolled PET film with a thickness of 50 microns
The film was set to 5 Vc and wound around the winding shaft in the same manner as in the comparative example. 1×10 (-6) in the sputtering chamber
After evacuation to a pressure below torr, the gas introduction system 6
Introduce Ar gas from 0 to approximately 3×10(-3) tor
maintained at r. 40mm/min&'> from the delivery shaft 71
Approximately 500 OA is applied to the 0 side of the PET film fed out at a feeding speed of 1000 µm by the sunozotsuta cathodes 91 and 92 at the position of the can 72, which is set at a constant temperature.
A nosemalloy film of about 270 OA and a Co-Cr film of about 270 OA were formed. The PET film with a two-layer film formed on one side in the can 72 is moved as it is to the can 76, which is also set at a constant temperature. Membrane and approx. 2
A 700 Aσ) Co—Cr film was formed and wound around a winding shaft 74. Here, Φ Yang temperature is 30, 60.90, 12
Five levels of 0,150°C were selected.

Co-
FIG. 4 shows the measured values of Hc (vertical) for the Cr film.

That is, as is clear from FIG. 4, the Hc (vertical) of the Co--Cr film of the double-sided double-layer perpendicular magnetization film according to the present invention is
- When the temporary can temperature of Cr1li sputtering exceeds 90°C, it increases rapidly, and especially when it exceeds 120°C, the temperature rises to 4000°C.
It can be seen that desirable characteristics as a perpendicular magnetization medium can be obtained.

Moreover, IC, NoR-Malloy film with a can temperature of 30°C or more when exposed to snow has little fluctuation in the reproduction output, especially 6
A perpendicular magnetization recording medium with almost no output fluctuation was obtained at 0°C.

On the other hand, in the case of a perpendicular magnetization recording medium made under conditions where the can temperature during permalloy film sputtering is 30°C or less, the reproduction output fluctuation is large and Vmax/Vmin shows a very low value, making it unsuitable for practical use. there were.

Regarding the surface properties of the obtained perpendicularly magnetized media, there is almost no deterioration when the can temperature during permalloy film sputtering is 900°C or lower, and when the can temperature is raised to 90°C or higher when sputtering a Co-Cr film. Even at 150° C., there was almost no deterioration, and even at 150° C., there was only slight cloudiness, so there was no problem in practical use.

As described above, the perpendicularly magnetized medium obtained in this comparative example had almost the same characteristics on the front and back sides as compared to the comparative example, and had less variation between samples and less curl. Furthermore, approximately 80% of the samples exhibited good recording and reproducing characteristics.

On the other hand, as shown in the comparative example, the can temperature was reduced to 9.
In a double-sided double-layer perpendicularly magnetized film created by sputtering two layers on each side while heating to 0°C or higher, Hc (vertical) does not increase much even if the can temperature is raised, as shown in Figure 4. In addition, there was a wide range of variation between samples, and results with poor redness were obtained.

Regarding the surface properties, when the can temperature is set to 90° C. or higher, significant cloudiness appears, which is thought to be due to oligomer precipitation, and it is found that the material is unsuitable as a perpendicular magnetization medium. Furthermore, it can be seen that the crystal orientation of the Co--Cr film also deteriorates, and the characteristics differ significantly between the front and back sides.

In addition, in this comparative example, a two-can type double-sided sputtering device was used, but for example, a four-can type double-sided sputtering device was used to change the permalloy film (0 side) → permalloy film (1 side) → Co-Cr film ( 1 side or 0 side) -+Co
It is obvious that the same effect can be obtained even if a two-layer film is formed on both sides in one pass in the order of -Cr film (0 side or 1 side).

In addition, in one comparative example, PET film was used, but comparative examples and comparative examples using PET film were used, except that no precipitation of oligomers was observed even when heat-resistant films such as boronomide films were used. Almost the same results were obtained, demonstrating the excellent effects of the present invention.

〔Effect of the invention〕

According to the method of the present invention, double-sided double-layered perpendicular magnetization recording having high HC (perpendicular), isotropic magnetostatic properties, uniform properties on both sides, and excellent electromagnetic conversion characteristics as a perpendicular magnetization recording medium It becomes possible to produce the medium at a high yield, and its practical value is extremely significant.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an example of the method of the present invention, FIGS. 2 and 3 are explanatory diagrams showing a conventional manufacturing method of a perpendicular magnetization recording medium, and FIG. A graph showing the relationship between can temperature and Hc, Figure 5 is a hard magnetic film,
eCan temperature and playback output stability in the circumferential direction during ivy (
FIG. 6 is a graph showing the envelope of the recording/reproducing output in the circumferential direction of the floppy disk. 51... Delivery chamber, 52... Sputter chamber 53... Winding chamber 72.75... Cylindrical can 91.93... Ri - Malloy (soft magnetic material) target 92, 94-=Co-Cr target No. 1
Figure 2, Figure 3vA, Figure 5, m6 (envelope of suit ΔIzumiyu-Mikyakusai) A (Ginkai) procedural amendment December 70, 1985 N+-2.1, case display 1988 Patent Application No. 268647 2, Name of the invention Perpendicular magnetization recording medium and its manufacturing method 3, Person making the amendment Relationship to the case: Name of patent applicant (520') Fuji Photo Film Co., Ltd. Kasumigaseki Pill Naigobin Bureau I wm No. 49 No. 6, Number of inventions increased by amendment 0 2) The "Detailed description of the invention" column of the specification is amended as follows. 1 Amendment to Figure Procedures February 2, 1986 “Japanese

Claims (1)

[Claims] 1) Soft magnetic films and Co and Cr on both sides of the film support.
In a perpendicular magnetization recording medium having a perpendicular magnetization film mainly composed of, the soft magnetic film is provided on a support by vapor deposition or sputtering at a temperature of 30°C to 90°C, and the perpendicular magnetization film is formed on the soft magnetic film. A perpendicular magnetization recording medium characterized in that it is provided by vapor deposition or sputtering at a temperature of 90° C. or higher. 2) In a method for manufacturing a perpendicular magnetization recording medium in which a perpendicular magnetization recording medium is formed having a soft magnetic film and a perpendicular magnetization film mainly composed of Co and Cr on both sides of a moving film-like support, After forming a soft magnetic film on both sides of the film-like support using a soft magnetic film evaporation source or sputtering source placed around a cylindrical can heated to 90°C, a film coated with the soft magnetic film is formed. Support at 90℃
A method for producing a perpendicularly magnetized recording medium, comprising forming a perpendicularly magnetized film using a evaporation source or a sputtering source for perpendicularly magnetized film disposed around a cylindrical can heated as described above.