JPH1041177A - Manufacturing method of magnetic recording medium - Google Patents

Abstract

(57) [Problem] To provide a uniform magnetic film even when the thickness of a support is thin, and to suppress a decrease in the running property of the support and damage to the support by heat during film formation. An object of the present invention is to provide a method for manufacturing a recording medium. A method of manufacturing a magnetic recording medium, wherein a magnetic film is formed by irradiating a magnetic material source with an electron beam and obliquely depositing evaporated particles on a traveling support,
The support has a thickness of 2 to 6 μm, and the irradiation direction of the electron beam and the running direction of the support are opposite to each other,
A method for manufacturing a magnetic recording medium, wherein the electron beam has a deflection angle of 60 ° to 95 °.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a magnetic recording medium in which a magnetic film is formed by oblique deposition.

[0002]

A method for manufacturing a metal thin film type magnetic recording medium in which a magnetic film is formed by oblique evaporation is widely known. However, conventional manufacturing methods are not satisfactory. For example, scattered electrons may be charged to the support during film formation, and the running properties of the support may be reduced, resulting in poor formation of the magnetic film. Further, the support may be damaged by heat, and a good magnetic film may not be obtained. For example, when the thickness of the support is reduced to 2 to 6 μm, damage due to diffusion of an electron beam and radiation heat from an evaporation source is extremely large.

[0003] As a measure against the decrease in running performance due to the charge of scattered electrons to the support, increasing the tension has been performed. However, as the thickness of the support decreases, the strain due to high tension increases. For this reason, as the thickness of the support becomes thinner, a problem occurs in the uniformity of the formed magnetic film in the longitudinal direction of the support. Accordingly, an object of the present invention is to provide a method for manufacturing a magnetic recording medium capable of obtaining a uniform magnetic film even when the thickness of the support is small.

Another object of the present invention is to provide
It is an object of the present invention to provide a method of manufacturing a magnetic recording medium capable of suppressing a decrease in running property of a support and damage to the support due to heat.

[0005]

An object of the present invention is to provide a magnetic recording medium which forms a magnetic film by irradiating a magnetic material source with an electron beam and obliquely depositing evaporated particles on a running support. In the manufacturing method, the support has a thickness of 2 to 6 μm, the direction of irradiation of the electron beam and the running direction of the support are opposite to each other, and the deflection angle of the electron beam is 60 °. The above problem is solved by a method for manufacturing a magnetic recording medium, which is characterized in that the angle is up to 95 °.

In particular, a magnetic material source is irradiated with an electron beam,
A method for manufacturing a magnetic recording medium, wherein a magnetic film is formed by obliquely depositing the evaporated particles on a running support, and an oxidizing gas is supplied when forming the magnetic film. A thickness of 2 to 6 μm, a supply direction of the oxidizing gas and a traveling direction of the support are opposite directions, and an irradiation direction of the electron beam and a traveling direction of the support are opposite directions; In addition, the problem is solved by a method for manufacturing a magnetic recording medium, wherein the deflection angle of the electron beam is 60 ° to 95 °.

[0007] Further, traveling from the supply roll to the take-up roll, during the traveling, the magnetic particles evaporated by electron beam irradiation are obliquely deposited in a vacuum atmosphere on the support attached to the cooling can roll. A method for producing a magnetic recording medium, wherein a magnetic film is formed by the method, and an oxygen gas is supplied when the magnetic film is formed, wherein the support has a thickness of 2 to 6 μm, The direction and the running direction of the support are opposite directions, and the irradiation direction of the electron beam and the running direction of the support are opposite directions,
In addition, the problem is solved by a method for manufacturing a magnetic recording medium, wherein the deflection angle of the electron beam is 60 ° to 95 °.

That is, when the film is formed under the above-mentioned conditions, the electron beam irradiation direction and the traveling direction of the support are made to be opposite to each other, and when the electron beam deflection angle is set to 60 ° to 95 °, the electron beam It is difficult for the scattered electrons from charging the support. Therefore, even if the tension during running of the support is small, the support is unlikely to be distorted, and a uniform magnetic film can be obtained in the longitudinal direction.

In particular, when a shielding member is provided between the electron beam irradiated to the evaporation source of the particles and the support during film formation, the scattered electrons from the electron beam are captured by the shielding member and are supported. Will not charge your body. Therefore, the tension during running of the support may be small, the support is unlikely to be distorted, and a uniform magnetic film in the longitudinal direction can be obtained. The reason why the shielding member can be disposed between the electron beam and the support is that the irradiation direction of the electron beam and the traveling direction of the support are reversed. In other words, when the direction is not the reverse, if a shielding member is provided between the electron beam and the support, a magnetic film having excellent magnetic properties cannot be obtained by the oblique deposition method.

The tension acting on the running support is 0.01 to 0.4 kg, particularly 0.02 to 0.1 kg.
By setting the weight per kg (per 1 cm of the width of the support), the support is hardly distorted and a magnetic film uniform in the longitudinal direction can be obtained. When a plurality of magnetic films are provided,
It is preferable that the output Pu of the electron gun when forming the upper magnetic film and the output Pl of the electron gun when forming the lower magnetic film adjacent to the upper magnetic film satisfy Pl ≦ 0.9 × Pu. Thereby, a higher saturation magnetic flux density can be obtained.

It is preferable that the minimum incident angle of the magnetic particles deposited on the support be 50 ° to 70 ° (particularly, 50 ° to 65 °). In addition, by providing a condition in which there is no shield between the bright spot caused by the irradiation of the magnetic material source with the electron beam and the support directly above the bright spot, the highest energy among the evaporated particles can be obtained. Particles having a can be effectively used.
Accordingly, since the packing density of the particles is further increased, a higher saturation magnetic flux density can be obtained. That is, a higher output can be obtained.

As shown in FIG. 1, if the traveling direction of the support is from right to left and the evaporation source is below the support, and if the electron gun is above and to the left of the evaporation source,
"The irradiation direction of the electron beam is opposite to the running direction of the support". Also, as shown in FIG. 1, the traveling direction of the support is from right to left, the evaporation source is below the support, and a nozzle for supplying oxygen gas is below the support, When the supply direction of the oxygen gas is from the left side to the right side, "the supply direction of the oxygen gas is opposite to the traveling direction of the support".

The minimum incident angle is an angle indicated by θ ₁ in FIG. The deflection angle θ ₂ of the electron beam is the angle at which the electron gun is pointing, and when the electron gun is in the horizontal direction, the deflection angle of the electron beam is 90 °.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The method of manufacturing a magnetic recording medium according to the present invention is directed to a magnetic recording medium in which a magnetic material source is irradiated with an electron beam and evaporated particles are obliquely deposited on a running support to form a magnetic film. In a method for manufacturing a medium, the support has a thickness of 2 to 6 μm (particularly, 2.5 to 5.5 μm), and a direction in which the electron beam is irradiated and a direction in which the support travels are opposite. And the deflection angle of the electron beam is 6
0 ° to 95 ° (particularly, 80 ° to 90 °). Especially,
A magnetic material source is irradiated with an electron beam, and a magnetic film is formed by obliquely depositing the evaporated particles on a running support, and an oxidizing gas is supplied during the formation of the magnetic film. In the manufacturing method, the support has a thickness of 2 to 6 μm (particularly, 2.5 to 5.5 μm), and a supply direction of the oxidizing gas is opposite to a running direction of the support. The irradiation direction of the electron beam and the traveling direction of the support are opposite directions, and the deflection angle of the electron beam is 60 ° to 95 ° (particularly, 80 ° to 90 °).
It is. Further, the magnetic material is moved from the supply roll to the take-up roll, and the evaporating magnetic particles by the electron beam irradiation are obliquely vapor-deposited in a vacuum atmosphere on the support attached to the cooling can roll during the traveling. A method for manufacturing a magnetic recording medium, wherein a film is formed and oxygen gas is supplied at the time of forming the magnetic film, wherein the support has a thickness of 2 to 6 μm (particularly, 2.5 to 5.5 μm). And
The supply direction of the oxygen gas and the traveling direction of the support are opposite directions, the irradiation direction of the electron beam and the traveling direction of the support are opposite directions, and the deflection angle of the electron beam is 60 degrees. ° to 95 ° (especially 80 ° to 90 °). Further, at the time of film formation, a shielding member is provided between the electron beam irradiated to the particle evaporation source and the support.
The minimum incident angle when depositing on a magnetic particle support is 50.
° to 70 ° (particularly 50 ° to 65 °). In addition, there is no shield between the bright spot due to the irradiation of the magnetic material source with the electron beam and the support directly above the bright spot. The tension acting on the running support in the longitudinal direction is 0.01 to 0.4 kg, particularly 0.02 to 0.1 kg.
(Per 1 cm width of the support). When a plurality of magnetic films are provided, the output Pu of the electron gun when forming the upper magnetic film and the output Pl of the electron gun when forming the lower magnetic film adjacent to the upper magnetic film are Pl ≦ 0. .9 ×
Pu is satisfied.

Hereinafter, further description will be given. FIG. 1 is a schematic view of an apparatus (oblique deposition apparatus) in which the method for manufacturing a magnetic recording medium according to the present invention is performed. In the figure, reference numeral 1 denotes a support. The support 1 is moved from the supply roll 2a to the take-up roll 2b.
Then, the vehicle runs from right to left as indicated by the arrow. During this traveling, the support 1 is in contact with the cooling can roll 3.

The support 1 may be either magnetic or non-magnetic. Generally, it is non-magnetic. Examples of the support include organic materials such as polyesters such as polyethylene terephthalate (hereinafter referred to as PET), olefin resins such as polyamide, polyimide, polysulfone, polycarbonate, and polypropylene; cellulose resins; and vinyl chloride resins. Resin) is used. Note that an undercoat layer for improving the adhesion to the magnetic film is appropriately provided on the surface of the support 1.

Reference numeral 4 denotes an ion bombard chamber for ion bombarding the surface of the support 1 at a position before the vapor deposition is performed. By this ion bombardment treatment, when evaporating particles described later are deposited on the support 1, the binding strength between the support and the evaporating particles is improved. Reference numeral 5 denotes a shielding plate provided below the cooling can roll 3.
The shielding plate 5 is provided at a portion corresponding to a position after the vapor deposition has been performed on the support 1. or,
The shielding plate 5 is provided with a support 1 for evaporating particles from a crucible described later.
Minimum incident angle theta ₁ at the time of deposition is set 50 ° to 70 ° (particularly, 50 ° ~65 °) and so as to. In addition, there is no shielding plate 5 between a luminescent spot X caused by irradiating an after-mentioned electron beam from an electron gun onto a magnetic metal material to be described later and the support 1 directly above the luminescent spot X. Is set. That is, there is no shielding between the bright spot X and the support 1 directly above the bright spot X, and when looking directly below the support 1 at the position directly above the bright spot X, the bright spot X is recognized. Can be done.

Reference numeral 6 denotes an oxygen gas supply nozzle disposed between the shielding plate 5 and the cooling can roll 3. Therefore, the supply direction of the oxygen supplied from the nozzle 6 is as shown in FIG.
The running direction of the support 1 is shown in FIG.
From right to left, therefore the oxygen gas supply direction and support 1
Is the direction opposite to the traveling direction. 7 is a cooling can roll 3
Is a crucible made of MgO provided at a position below the crucible. The crucible 7 is filled with a magnetic metal material 8. In addition, as the magnetic metal material, Fe, Co, Ni, an alloy thereof, and a nitride or carbide thereof are appropriately used.

Reference numeral 9 denotes an electron gun provided at the upper left position of the crucible 7, and an electron beam from the electron gun 9 is irradiated to a magnetic metal material 8 in the crucible 7 and irradiated. Therefore, the irradiation direction of the electron beam indicated by the arrow and the traveling direction of the support 1 are opposite to each other. The deflection angle θ ₂ of the electron beam from the electron gun 9
Is set to 60 ° to 95 ° (particularly, 80 ° to 90 °). Further, since the shielding plate 5 is provided on the electron gun 9 and the shielding plate 5 is provided on the electron beam from the electron gun 9, the scattered electrons from the electron beam are difficult to charge the support 1. ing.

Reference numeral 10 denotes a vacuum chamber. In the above device,
First, the inside of the vacuum chamber 10 is evacuated to a degree of vacuum of 10 ^-4 to 10 ^-6 Torr. Then, the magnetic metal material 8 is irradiated with an electron beam from the electron gun 9 and evaporated. As a result, the magnetic metal particles have a minimum incident angle θ ₁ of 50 ° to 70 ° (in particular, 5 ° to 70 °).
(0 ° to 65 °), and obliquely vapor-deposits on the running support 1 while applying a tension of 0.01 to 0.4 kg (per 1 cm width of the support). During the oblique deposition, oxygen gas is supplied from the nozzle 6 at 10 to 5000 sccm, and the surface of the magnetic film is oxidized. Then, a metal thin film type magnetic film having a thickness of 800 to 5000 (especially 1000 to 2500) is provided.

On the surface of the magnetic film, a protective film having a thickness of 10 to 500 ° is provided. As a material constituting the protective film, A
In addition to oxides, nitrides, and carbides of metals such as 1 and the like, SiC and the like and compounds containing the same can be considered. Particularly, diamond-like carbon is preferable. The protective film made of diamond-like carbon is formed by a chemical vapor deposition (CVD) method. In particular, it is formed by an ECR plasma CVD apparatus. That is, the ECR plasma CVD apparatus is operated on the magnetic film on the support provided in the vacuum chamber, and plasma of the hydrocarbon gas is blown on the magnetic film. Thus, a protective film (diamond-like carbon film) is formed on the surface of the magnetic film.

On the other surface (back surface) of the support 1, a back coat film is provided. For example, vapor deposition, DC sputtering,
The back coat film is provided by a plating method such as an AC sputtering method, a high frequency sputtering method, a DC magnetron sputtering method, a high frequency magnetron sputtering method, and an ion beam sputtering method. The back coat film is also provided by applying a paint containing carbon black and a binder.

On the surface, a lubricant, especially
Fluorine-based lubricant paint such as olopolyether is applied.
And a lubricant film having a thickness of 5 to 50 ° is provided. still,
As the lubricant, for example,-(C (R) F-CF_Two-O)_p-(However, R
Is F, CF_Three, CH_ThreeSuch as HOOC-CF)_Two(O-C_TwoF
_Four)_p(OCF_Two)_q -OCF_Two-COOH, F- (CF_TwoCF_TwoCF_TwoO)_n-CF_TwoCF _TwoC
Perfluoropolyether modified with carboxyl groups such as OOH
Le, HOCH_Two-CF_Two(O-C_TwoF_Four) _p(OCF_Two)_q -OCF_Two-CH_TwoOH, HO- (C
_TwoH_Four-O)_m-CH_Two-(O-C_TwoF_Four)_p(OCF_Two)_q -OCH_Two-(OCH_TwoCH_Two)
_n-OH, F- (CF_TwoCF_TwoCF_TwoO)_n-CF_TwoCF_TwoCH_TwoAlcohol such as OH
Modified perfluoropolyethers may be mentioned. The molecular weight is
Those having 500 to 50,000 are preferred. Specifically,
Ntecacini's product name FOMBLIN Z DIAC
And FOMBLIN Z DOL, a product of Daikin Industries, Ltd.
There is the name Demnum SA.

In the following embodiments, Co is used as a constituent material of the magnetic film, but the present invention is not limited to a magnetic recording medium made of Co.

[0025]

Example 1 The apparatus shown in FIG. 1 was used. The support 1 is 2.
5 μm thick PET film. And 20-30
A back coat paint containing carbon black having a diameter of nm and a binder resin was applied to the back surface of the PET film, and a back coat film having a dry thickness of 0.5 μm was provided. When the support 1 is loaded into the apparatus, the back coat film is in contact with the cooling can roll 3.

Then, a magnetic film having a thickness of 1500 ° was formed under the following conditions. The running speed of the support 1 is 10 m / min, and the tension acting on the support 1 in the longitudinal direction (support running direction) is 0.04 kg (per 1 cm width of the film). The diameter of the cooling can roll 3 is 40 cm, and the temperature of the cooling can roll 3 is controlled to -10 ° C.

The shielding plate 5 is kept cooled at 10 ° C.
The supply amount of oxygen from the nozzle 6 is 200 sccm. The crucible 7 is filled with Co, which evaporates therefrom and has a minimum incident angle θ ₁ of 55 ° when obliquely deposited on the support 1. When looking directly below the support 1 at the position directly above the bright spot X, the bright spot X can be recognized.

The output P of the electron gun 9 is 30 kW, the deflection angle θ ₂
Is 90 °. Next, a diamond-like carbon film having a thickness of 100 mm was provided on the magnetic film by an ECR plasma CVD apparatus. Also, a lubricant (Demnum SA) film is provided on the surface in a thickness of 20 mm, and thereafter, through an ordinary process, an 8 mm VTR is formed.
Magnetic tape was obtained.

[0029]

Example 2 In Example 1, a PET having a thickness of 4.5 μm was used.
8 mm VTR according to Example 1 except that a film was used
Magnetic tape was obtained.

[0030]

EXAMPLE 3 In Example 1, a PET having a thickness of 5.5 μm was used.
8 mm VTR according to Example 1 except that a film was used
Magnetic tape was obtained.

[0031]

Example 4 An 8 mm VTR magnetic tape was obtained in the same manner as in Example 1 except that θ _{2 was} 65 °.

[0032]

Example 5 An 8 mm VTR magnetic tape was obtained in the same manner as in Example 1 except that the tension applied to the support 1 was changed to 0.08 kg (per 1 cm width of the film).

[0033]

Embodiment 6 In Embodiment 2, the traveling speed of the support is equal to 2
The procedure was performed in the same manner as in Example 1 except that 0 m / min and the oxygen supply rate were set to 100 sccm. Further, thereafter, the procedure was performed in the same manner as in Example 1 except that the running speed of the support was 22 m / min, the oxygen supply amount was 140 sccm, and the output P of the electron gun 9 was 40 kW. Then, an 8 mm VTR magnetic tape was obtained in the same manner as in Example 1 except that the lower magnetic film had a thickness of 800 mm, and the upper magnetic film had a thickness of 1000 mm.

[0034]

Comparative Example 1 A magnetic tape for 8 mm VTR was obtained in the same manner as in Example 1 except that θ _{2 was} 45 °.

[0035]

COMPARATIVE EXAMPLE 2 The same procedure as in Example 1 was carried out except that the installation position of the electron gun 9 was set to a position symmetrical to the case of FIG. 1, and the irradiation direction of the electron beam and the traveling direction of the support were forward. According to Example 1, an 8 mm VTR magnetic tape was obtained.

[0036]

[Characteristics] With respect to the magnetic tape for 8 mm VTR obtained in each of the above examples, the magnetic characteristics (saturation magnetic flux density B
s, coercive force Hc) and electromagnetic conversion characteristics (C /
N, C / N at 10 MHz) are shown in Tables 1 and 2. Table 1 (Saturation magnetic flux density Bs (G), coercive force Hc (Oe)) 0m 200m 400m 600m 800m 1000m Bs Hc Bs Hc Bs Hc Bs Hc Bs Hc Bs Hc Example 1 6100 1600 6100 1610 6000 1630 6000 1600 6050 1620 5900 1640 Example 2 6000 1610 6200 1600 6000 1620 6100 1600 6300 1590 6100 1600 Example 3 6200 1600 6100 1620 6100 1620 6100 1610 6300 1620 6200 1610 Example 4 6000 1570 6000 1580 6200 1590 6000 1590 5700 1540 5600 1530 Example 5 6200 1610 6100 1610 6100 1600 6000 1590 6300 1600 6100 1610 Example 6 6200 1640 6100 1650 6200 1650 6200 1640 6000 1650 6000 1640 Comparative Example 1 5600 1580 5900 1490 4800 1600 4500 1720 5400 1600 5000 1670 Comparative Example 2 5900 1570 6000 1480 4900 1660 4300 1750 4700 1700 5900 1540 Table-2 (5 MHz C / N, 10 MHz C / N (dB)) 0m 200m 400m 600m 800m 1000m 5 10 5 10 5 10 5 10 5 10 5 10 10 Example 1 +0.4 + 0.5 +0.4 +0.6 +0.3 +0.4 +0.4 +0.4 +0.5 +0.5 +0.3 +0.5 Example 2 +0.5 +0.7 +0.7 +0.7 +0.6 +0.9 +0.7 +0.5 +0.4 +0.8 +0.3 +0.6 Example 3 +0.8 +0.7 +0.7 +0.9 +0.6 +1.0 +0.8 +0.8 +0.8 +0.9 +0.8 +0.9 Example 4 +0.5 +0.6 +0.3 +0.7 +0.6 +0.8 +0.5 +0.5 +0.4 +0.4 +0.3 +0.2 Example 5 +0.8 +0.9 +0.7 +1.1 +0.9 +0.9 +0.8 +0.7 +1.1 +1.2 +0.9 + 1.0 Example 6 +1.4 +1.9 +1.5 +2.1 +1.6 +2.1 +1.5 +2.2 +1.4 +1.8 +1.4 +1.4 Comparative Example 1 +0.1 +0.3 +0.1 +0.8 -0.3 -0.4 -0.5 00 +0.3 0 -0.5 Comparative Example 2 +0.5 +0.3 +0.1 -0.4 +0.3 +0.4 -0.40 -0.40 +0.2 +0.6 * Magnetic properties were determined by VSM (manufactured by Riken Denshi).

* Output was measured using a modified version of a commercially available Hi8 VTR, and the output was determined based on a predetermined position in Comparative Example 1 (0d
B). According to this, a magnetic film obtained by the method of the present invention has excellent magnetic properties and electromagnetic conversion properties.

[0038]

According to the present invention, scattered electrons are less likely to be charged on the support during film formation, and a decrease in the running property of the support is suppressed.
A uniform and good magnetic recording medium can be efficiently obtained without the support being damaged by heat. Moreover, since the support is thin, a longer one can be loaded in a cassette of the same standard.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an apparatus for manufacturing a magnetic recording medium.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Support 3 Cooling can roll 5 Shield plate 6 Oxygen gas supply nozzle 7 Crucible 8 Magnetic metal material 9 Electron gun 10 Vacuum tank X Bright spot

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Katsumi Endo 2606 Akabane, Kaigacho, Haga-gun, Tochigi Kao Co., Ltd. In-house Information Science Laboratories (72) Inventor Takeshi Miyamura 2606 Akabane, Kaigamachi, Haga-gun, Tochigi Prefecture Kao Corporation In-house Information Science Laboratories

Claims (6)

[Claims] 1. A method for producing a magnetic recording medium, comprising: irradiating a magnetic material source with an electron beam and obliquely depositing evaporated particles on a running support to form a magnetic film, wherein the support has a thickness of Wherein the irradiation direction of the electron beam and the traveling direction of the support are opposite to each other, and the deflection angle of the electron beam is 60 ° to 95 °. Manufacturing method of recording medium. 2. The method according to claim 1, further comprising: traveling from the supply roll to the take-up roll, and in the middle of the travel, obliquely depositing, under a vacuum atmosphere, magnetic particles evaporated by electron beam irradiation on a support attached to the cooling can roll. A method for producing a magnetic recording medium, wherein a magnetic film is formed by the method, and an oxygen gas is supplied at the time of forming the magnetic film, wherein the support has a thickness of 2 to 6 μm; And the direction of travel of the support is opposite to the direction of irradiation of the electron beam and the direction of travel of the support is opposite, and the deflection angle of the electron beam is 60 ° to 95 °. A method for manufacturing a magnetic recording medium, comprising: 3. The method for manufacturing a magnetic recording medium according to claim 1, wherein a shielding member is provided between the electron beam irradiated to the particle evaporation source and the support. . 4. The method according to claim 1, wherein an oxidizing gas is supplied when the particles are deposited on the support, and the supply direction of the oxidizing gas and the running direction of the support are opposite to each other. A method for manufacturing a magnetic recording medium. 5. The method according to claim 1, wherein said support is 0.01 to 0.2.
3. The method for manufacturing a magnetic recording medium according to claim 1, wherein a tension of 4 kg (per 1 cm width of the support) is applied. 6. A magnetic film is provided in a plurality of layers, and the output Pu of the electron gun when forming the upper magnetic film and the output Pl of the electron gun when forming the lower magnetic film adjacent to the upper magnetic film are Pl ≦ 0. 3. The method for manufacturing a magnetic recording medium according to claim 1, wherein 0.9 × Pu is satisfied.