JPH1091956A - Manufacturing method of magnetic recording medium - Google Patents

Abstract

(57) [Problem] To provide a magnetic recording medium having an Fe-XO-based magnetic film excellent in electromagnetic conversion characteristics and durability without using an ion gun. A method for manufacturing a magnetic recording medium having a magnetic film of Fe-X-O (X is an element that can exist alone as a solid) on a support, wherein X particles are scattered by a discharge means And a step of evaporating Fe, and a step of supplying an oxidizing substance at the time of forming the magnetic film by the above step.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a magnetic recording medium having an Fe--X--O based magnetic film.

[0002]

There is known a metal thin film type magnetic recording medium in which a magnetic film is formed by vapor deposition or sputtering. As a material constituting this magnetic film, for example, Co-N
i or a Co—Cr-based magnetic alloy is used. However, Co, Ni, Cr and the like are expensive. For this reason, attention was paid to Fe.

However, since Fe is inferior in corrosion resistance, it has been proposed that the magnetic film be made of Fe—X—O (X = Si, P, B, C, etc.) (Japanese Patent Laid-Open No. 6-104114, Kaihei 6-104115, JP-A-6-104116,
JP-A-6-104117). These proposed magnetic recording media evaporate Fe particles, irradiate X (X = Si, P, B, C, etc.) ions to the deposited Fe film using an ion gun, and apply oxygen gas to the deposited Fe film. It is manufactured by irradiating.

However, in order to irradiate the deposited Fe film with Si ions, a dangerous gas such as SiH ₄ must be supplied to the ion gun. Furthermore, ion guns are expensive. Further, in order to cope with a narrow track and a short wavelength recording which will be developed in the future, further higher output is required. Also, durability is required. In other words, a material that exceeds the characteristics obtained by the above-mentioned proposal is required, and technical development for that purpose has been awaited.

Accordingly, an object of the present invention is to provide a magnetic recording medium having a Fe—X—O-based magnetic film having more excellent electromagnetic conversion characteristics. or,
Another object of the present invention is to provide a magnetic recording medium having an Fe—X—O-based magnetic film having excellent durability. Another object of the present invention is to provide a magnetic recording medium having an Fe—X—O-based magnetic film having excellent electromagnetic conversion characteristics and durability without using an ion gun.

[0006]

An object of the present invention is to provide a method for producing a magnetic recording medium having a magnetic film of Fe--X--O (X is an element which can exist as a solid) on a support. A method for producing a magnetic recording medium, comprising: a step of scattering X particles by a discharge means; a step of evaporating Fe; and a step of supplying an oxidizing substance when forming a magnetic film in the above step. Solved by

In particular, the present invention relates to a method for producing a magnetic recording medium having a Fe--CO--based magnetic film on a support, wherein a step of scattering carbon particles by arc discharge, a step of evaporating Fe, And a step of supplying an oxidizing substance at the time of forming a magnetic film by the method described above.

Further, there is provided a method for producing a magnetic recording medium having a Fe--CO--based magnetic film on a support, wherein carbon particles are scattered from a carbon mass by arc discharge and adhered on the support. A magnetic layer comprising: an attaching step; an attaching step of evaporating Fe to attach Fe particles on the support; and a step of supplying an oxidizing substance when forming a magnetic film in the attaching step. The problem is solved by a method for manufacturing a recording medium.

A method for producing a magnetic recording medium having a Fe—Si—O-based magnetic film on a support, comprising: a step of scattering silicon particles by arc discharge; a step of evaporating Fe; And a step of supplying an oxidizing substance at the time of forming a magnetic film by the method described above.

Further, the present invention relates to a method of manufacturing a magnetic recording medium having a Fe-Si-O-based magnetic film on a support, wherein silicon particles are scattered from silicon chunks by arc discharge and adhere to the support. A magnetic layer comprising: an attaching step; an attaching step of evaporating Fe to attach Fe particles on the support; and a step of supplying an oxidizing substance when forming a magnetic film in the attaching step. The problem is solved by a method for manufacturing a recording medium.

In the above manufacturing method, it is preferable that the evaporated Fe particles pass through a plasma atmosphere caused by electric discharge and adhere to the support. That is, evaporating Fe
By passing the particles through the plasma atmosphere, the energy of the evaporated Fe particles increases, and the binding property increases. still,
Since the silicon mass has low conductivity, it is preferable to include a conductivity improving substance such as P, for example. This makes it easier to cause discharge.

According to the above method, the Fe--X--O based magnetic film can be formed without using an expensive ion gun. Moreover, there is no need to handle dangerous gas. As a result, the cost is reduced. Further, using an ion gun, Fe-X
Crystallinity is better and a dense film can be obtained as compared with the case where an -O-based magnetic film is formed. As a result, the saturation magnetic flux density Bs
And a high output is obtained. Also, the durability is good.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The method of manufacturing a magnetic recording medium according to the present invention is directed to a method of manufacturing a magnetic recording medium having a Fe--X--O (X is an element which can exist as a solid) magnetic film on a support. The manufacturing method includes a step of scattering X particles by a discharge means, a step of evaporating Fe, and a step of supplying an oxidizing substance when forming a magnetic film in the above-described step.
In particular, a method for manufacturing a magnetic recording medium having a Fe—CO—based magnetic film on a support, comprising: a step of scattering carbon particles by an arc discharge; a step of evaporating Fe; Supplying an oxidizing substance at the time of film formation. Further, there is provided a method for producing a magnetic recording medium having a Fe-CO-based magnetic film on a support, comprising: an adhesion step in which carbon particles are scattered from a carbon lump by arc discharge and adhered to the support. , A step of depositing Fe particles on the support by evaporating Fe, and a step of supplying an oxidizing substance during the formation of the magnetic film in the step of depositing. A method of manufacturing a magnetic recording medium having a Fe-Si-O-based magnetic film on a support, comprising: a step of scattering silicon particles by arc discharge; a step of evaporating Fe; Supplying an oxidizing substance at the time of film formation. Further, Fe-S is provided on the support.
A method for producing a magnetic recording medium having an i-O-based magnetic film, comprising the steps of: causing silicon particles to be scattered from a silicon lump by arc discharge; and attaching the particles to the support; and evaporating Fe to remove Fe particles. The method further includes a step of attaching to the support, and a step of supplying an oxidizing substance when the magnetic film is formed in the attaching step. The evaporated Fe particles pass through the plasma atmosphere caused by the discharge and adhere to the support. The silicon lump contains a conductivity improving substance such as P.

The details will be described below. FIG. 1 is a schematic diagram of a film forming apparatus (oblique deposition apparatus) used for carrying out the present invention. In the figure, 1 is a cooling can roll, 2a is a support 3
Is a roll on the supply side and 2b is a roll on the winding side of the support 3. The support 3 is wound from the supply roll 2a to the take-up roll 2b via the cooling can roll 1. The support 3 may be either magnetic or non-magnetic. Generally, it is non-magnetic. As the support, organic materials such as olefin-based resins such as polyester, polyamide, polyimide, polysulfone, polycarbonate and polypropylene such as PET, cellulose-based resins, and vinyl chloride-based resins are used. An undercoat layer for improving the adhesion to the magnetic film is provided on the surface of the support 3 as necessary. If necessary, the surface of the support 3 is subjected to ion bombardment.

4 is a crucible, 5 is F filled in the crucible 4
e. Reference numeral 6 denotes a shielding plate provided below the cooling can roll 1. The shielding plate 6 is provided at a portion corresponding to a position after the vapor deposition is performed on the support 3. The shielding plate 6 has a minimum incident angle θ ₁ of 5 when the evaporated Fe particles from the crucible 4 are deposited on the support 3.
The angle is set to be 0 ° to 70 °.

Reference numeral 7 denotes an oxygen gas supply nozzle disposed between the shielding plate 6 and the cooling can roll 1. The supply direction of oxygen supplied from the nozzle 7 is from left to right in FIG. 1, and the traveling direction of the support 3 is from right to left in FIG. 1 is a direction opposite to the traveling direction. Reference numeral 8 denotes an electron gun, and the electron beam from the electron gun 8 is applied to the Fe5 in the crucible 4.

Reference numeral 9 denotes an arc discharge device, and 9a denotes a carbon lump (carbon rod) or silicon lump (silicon rod) loaded in the arc discharge apparatus 9. In addition, the carbon particles (silicon particles) scattered by arc discharge of the carbon rod (silicon rod) 9a fly in the flight region of the evaporating Fe particles, and the evaporating Fe particles flow in the plasma atmosphere by the arc discharge. A carbon rod (silicon rod) 9a is installed so as to fly.

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 electron beam from the electron gun 8 is changed to Fe
Irradiate 5 and evaporate. Incidentally, instead of the electron beam irradiation, a means such as resistance heating or high frequency heating can be adopted. In addition, the switch of the arc discharge device 9 is turned on to start arc discharge. Thereby, for example, carbon particles are scattered. Then, the evaporated Fe particles pass through the plasma atmosphere by the arc discharge device 9 and are obliquely deposited on the running support 3 with the minimum incident angle θ ₁ of 50 ° to 70 °. In addition, the carbon particles are obliquely deposited on the support 3 together with the Fe particles. During this oblique deposition,
Oxygen gas is supplied from the nozzle 7 at 10 to 100 sccm, and the surface of the magnetic film is oxidized. And the thickness is 80
0 to 5000 ° (especially 1000 to 2500 °) Fe
A -CO based magnetic film is provided. When arc discharge is performed using a silicon rod instead of a carbon rod, Fe-Si-O
A system magnetic film is provided.

The Fe—CO—based magnetic film contains 50 to 9 Fe.
0 atomic% (particularly, 60 to 85 atomic%), C is 3 to 35 atomic% (particularly, 5 to 30 atomic%), and O is 5 to 25 atomic%.
(Especially, 7 to 20 atomic%). With such a composition, a coercive force Hc of 1100 Oe or more, a saturation magnetic flux density Bs of 4000 G or more, excellent corrosion resistance, high hardness, and a dense film are obtained. .

The Fe—Si—O based magnetic film contains 50 to 50% Fe.
90 atomic% (especially, 60 to 85 atomic%), Si is 3 to 3
Those having a composition ratio of 5 atomic% (particularly 5 to 30 atomic%) and O of 5 to 25 atomic% (particularly 7 to 20 atomic%) are preferable. By having such a composition,
The film has a coercive force Hc of 1100 Oe or more, a saturation magnetic flux density Bs of 4000 G or more, has excellent corrosion resistance, high hardness, and is a dense film.

The surface of the Fe—X—O based magnetic film has a thickness of 1
A 0-500 ° protective film is provided. Examples of a material forming the protective film include oxides, nitrides, and carbides of metals such as Al. Particularly, diamond-like carbon is preferable. The protective film made of diamond-like carbon is a chemical vapor deposition (CV)
The film is formed by the method D). In particular, ECR plasma CVD
The film is formed by the device. 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 3, 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.

The surface is coated with a lubricant, particularly a fluorine-based lubricant such as perfluoropolyether, to form a lubricant film having a thickness of 10 to 200 °.
As the lubricant, for example, - (C (R) F- CF 2 -O) p - ( where group such as R is _{F, CF 3, CH 3)} , in particular HOOC-CF ₂
(OC ₂ F ₄ ) _p (OCF ₂ ) _q -OCF ₂ -COOH, F- (CF ₂ CF ₂ CF ₂ O) _n -C
Carboxyl group-modified perfluoropolyether such as F ₂ CF ₂ COOH, HOCH ₂ -CF ₂ (OC ₂ F ₄ ) _p (OCF ₂ ) _q -OCF ₂ -CH ₂ OH,
HO- (C ₂ H ₄ -O) _m -CH _2- (OC ₂ F ₄ ) _p (OCF ₂ ) _q -OCH _2- (OCH ₂
And alcohol-modified perfluoropolyethers such as CH ₂ ) _n -OH and F- (CF ₂ CF ₂ CF ₂ O) _n -CF ₂ CF ₂ CH ₂ OH. The molecular weight is preferably from 500 to 50,000. Specifically, FOMBLIN Z DIAC of Montecatini
And FOMBLIN Z DOL, Demnum SA of Daikin Industries, and the like.

[0024]

Example 1 The apparatus shown in FIG. 1 was used. Support 3 is 6.
It is a 3 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 3 is loaded in the apparatus, the back coat film is in contact with the cooling can roll 1.

Then, under the following conditions, an 1830 mm thick Fe
A -CO (Fe: C: O = 85: 9: 6 (atomic ratio)) based magnetic film was formed. The temperature of the cooling can roll 1 is -20.
℃ controlled. The traveling speed of the support 3 is 2 m / min. The supply amount of oxygen from the nozzle 7 is 33 sccm. Crucible 4 was filled with Fe having a purity of 99.9%.

The electron gun 8 irradiates an electron beam through the Fe 5 in the crucible 4 to evaporate Fe particles from the molten Fe. The minimum incident angle for oblique deposition on the support 3 is 55 °
It is. An AC voltage of 500 V was applied to the arc discharge device 9 and a current of 10 A was passed to cause an arc discharge in the carbon rod 9a.

Next, benzene was supplied to the ECR plasma CVD apparatus, and a diamond-like carbon film having a thickness of 85 mm was provided on the magnetic film. In addition, a lubricant (Demnum S
A) The film of A) is provided with a thickness of 20 °, and then Hi through a normal process.
An 8 mm VTR magnetic tape was obtained.

[0028]

Example 2 In Example 1, the amount of evaporation of the Fe particles and the conditions of the arc discharge were changed to change the Fe-C-
Example 1 was repeated except that an O (Fe: C: O = 83: 10: 7 (atomic ratio)) magnetic film was formed.

[0029]

Example 3 In Example 1, the amount of evaporation of Fe particles and the conditions of arc discharge were changed to change the Fe-C-
Example 1 was repeated except that an O (Fe: C: O = 80: 12: 8 (atomic ratio)) magnetic film was formed.

[0030]

Example 4 In Example 1, 13 carbons were used instead of carbon rods.
A silicon rod doped with 0 ppm of P was charged into an arc discharge device, and a 1860 ° thick Fe—Si—O (Fe: Si: O
= 85: 6: 9 (atomic ratio)) A magnetic film was formed in the same manner as in Example 1 except that a magnetic film was formed.

[0031]

Fifth Embodiment In the fourth embodiment, the amount of evaporation of Fe particles and the condition of arc discharge are changed to change the Fe-Si
Example 4 was performed except that a -O (Fe: Si: O = 83: 9: 8 (atomic ratio)) magnetic film was formed.

[0032]

Example 6 In Example 4, the amount of evaporation of Fe particles and the conditions of arc discharge were changed to change the 1810
-O (Fe: Si: O = 79: 11: 10 (atomic ratio))
The procedure was performed in the same manner as in Example 4 except that a system magnetic film was formed.

[0033]

[Comparative Example 1] In Example 1, the arc discharge device was operated.
Do not let the ion gun CH _FourTo supply C
And irradiates it with 1830 ° thick Fe—CO— (Fe:
C: O = 83: 7: 10 (atomic ratio)) based magnetic film
The procedure was performed in the same manner as in Example 1 except for the above.

[0034]

Comparative Example 2 In Example 4, the arc discharge device was not operated, and instead, SiH ₄ was supplied to the ion gun to produce Si.
Irradiated with ions, the Fe-Si-O (F
e: Si: O = 82: 8: 10 (atomic ratio)) A magnetic film was formed in the same manner as in Example 4 except that a magnetic film was formed.

[0035]

[Characteristics] Magnetic properties (saturation magnetic flux density Bs, coercive force Hc) of the magnetic tape for Hi8mm VTR obtained in each of the above examples.
And the electromagnetic conversion characteristics (output) were examined. The results are shown in Table 1. Table 1 Saturation magnetic flux density Bs (G) Coercive force Hc (Oe) Output (dB) Example 1 5600 1560 +0.8 Example 2 5400 1580 +1.2 Example 3 5200 1600 +1.8 Comparative example 1 5300 1550 0 Example 4 5700 1580 +0.3 Example 5 5500 1610 +0.9 Example 6 5200 1630 +1.2 Comparative Example 2 5300 1600 0 * Magnetic properties were determined by VSM (vibration sample magnetometer manufactured by Rigaku Denki).

* Output is a modified DVC camcorder,
A sine wave of 21 MHz was recorded, and the reproduction output after continuous reproduction in the still mode for 100 hours was measured. Examples 1 to 3 are based on Comparative Example 1 (0 dB). Examples 4 to 6 are based on Comparative Example 2 (0 dB). According to this, it is understood that the magnetic film obtained by the method of the present invention has excellent magnetic properties, high output, and excellent durability.

[0037]

According to the present invention, a magnetic recording medium having excellent magnetic characteristics, electromagnetic conversion characteristics, and durability can be obtained at low cost.

[Brief description of the drawings]

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

[Explanation of symbols]

 Reference Signs List 1 cooling can roll 3 support 4 crucible 5 Fe 7 nozzle 8 electron gun 9 arc discharge device 9a carbon rod (silicon rod)

 ────────────────────────────────────────────────── ─── 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 (7)

[Claims] 1. A method for producing a magnetic recording medium having a magnetic film of Fe—X—O (X is an element that can exist alone as a solid) based on a support, wherein X particles are scattered by discharge means. A method for producing a magnetic recording medium, comprising: a step of evaporating Fe; and a step of supplying an oxidizing substance when forming a magnetic film in the step. 2. A method for manufacturing a magnetic recording medium having a Fe—CO—based magnetic film on a support, comprising: a step of scattering carbon particles by arc discharge; a step of evaporating Fe; Supplying an oxidizing substance during the formation of the magnetic film according to (1). 3. A method for producing a magnetic recording medium having a Fe—CO—based magnetic film on a support, wherein the carbon particles are scattered from a carbon lump by arc discharge and adhered on the support. Magnetic recording, comprising: a step of depositing Fe particles on the support by evaporating Fe, and a step of supplying an oxidizing substance at the time of forming a magnetic film by the attaching step. The method of manufacturing the medium. 4. A method for producing a magnetic recording medium having a Fe—Si—O-based magnetic film on a support, comprising: a step of scattering silicon particles by arc discharge; a step of evaporating Fe; Supplying an oxidizing substance during the formation of the magnetic film according to (1). 5. A method for producing a magnetic recording medium having a Fe—Si—O-based magnetic film on a support, wherein the silicon particles are scattered from a silicon lump by arc discharge and adhere to the support. Magnetic recording, comprising: a step of depositing Fe particles on the support by evaporating Fe, and a step of supplying an oxidizing substance at the time of forming a magnetic film by the attaching step. The method of manufacturing the medium. 6. The method for manufacturing a magnetic recording medium according to claim 1, wherein the evaporated Fe particles pass through a plasma atmosphere caused by discharge and adhere to a support. 7. The method of manufacturing a magnetic recording medium according to claim 5, wherein the silicon lump contains a conductivity improving substance.