JP2822212B2 - Oblique orientation method and oblique orientation device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an oblique orientation method and an oblique orientation apparatus for obliquely orienting a magnetic powder contained in a magnetic coating film with respect to the surface of the magnetic coating film. .

(Summary of the present invention)

The present invention provides an oblique orientation method in which the magnetic powder contained in the magnetic coating is obliquely oriented with respect to the magnetic coating surface, wherein a magnetic field component substantially perpendicular to the magnetic coating surface and a magnetic field component substantially parallel to the magnetic coating surface are provided. By applying a magnetic field component at the same time, the magnetic powder is to be obliquely oriented by a magnetic field in an oblique direction due to the sum of the vectors of these magnetic field components.

Further, the present invention relates to a magnet and a magnetic coating, which apply a magnetic field component substantially perpendicular to the surface of the magnetic coating in an oblique orientation device in which the magnetic powder contained in the magnetic coating is obliquely oriented with respect to the surface of the magnetic coating. By cooperating with a magnet that applies a magnetic field component that is substantially parallel to the surface, a magnetic field that is oblique to the magnetic coating surface is generated, and the inclination of the magnetic field in the oblique direction is precisely controlled over a low angle. Is what you do.

[Conventional technology]

In general, magnetic recording uses a method using magnetization in a longitudinal direction in a plane of a magnetic recording medium. However, if the recording density is to be further improved by this method, the recording density is limited due to an increase in the demagnetizing field in the medium, and the recording density cannot be improved so much. That is, in this method,
Although the characteristics in the long wavelength region are improved, there is a disadvantage that the characteristics in the short wavelength region are inferior.

For this reason, a perpendicular magnetic recording system in which recording is performed by magnetization in the thickness direction of a magnetic recording layer of a magnetic recording medium has been conventionally proposed. According to the perpendicular magnetic recording method, since the demagnetizing field decreases as the recording density increases, it is known that the recording is superior to the recording by the in-plane longitudinal magnetization especially in high-density recording and short-wavelength recording. Have been.

However, when a needle-like magnetic powder or the like is oriented in a direction perpendicular to the magnetic recording layer, the characteristics in the short wavelength region are improved, but the characteristics in the long wavelength region are reduced. .

Therefore, an oblique orientation technique has been proposed which can improve the drawbacks of the in-plane longitudinal recording method and the perpendicular magnetic recording method and exhibit a high output from a long wavelength range to a short wavelength range.

The oblique orientation technique is applied to a coating type magnetic recording medium.
The magnetic powder is oriented obliquely with respect to the surface of the magnetic coating to improve the electromagnetic conversion characteristics and to exhibit high output from a long wavelength range to a short wavelength range. In addition to the coating type magnetic recording medium, there is also a deposition type magnetic recording medium in which an obliquely deposited film is formed by depositing Co-Cr or the like from an oblique direction. Since it is necessary to use an apparatus such as an apparatus or a sputtering apparatus, the manufacturing cost is inevitably increased, which is disadvantageous as compared with a coating type magnetic recording medium. Therefore, it is desirable that the coating type magnetic recording medium be obliquely oriented.

To perform oblique orientation with respect to the coating type magnetic recording medium,
Until now, a pair of magnets was inclined at a predetermined angle to the magnetic coating surface to generate an oblique magnetic field, and this magnetic field was used to tilt the magnetic powder in the magnetic coating film obliquely to the magnetic coating surface. Has been done.

[Problems to be solved by the invention]

However, in such a case, the magnetic field on the low angle side (when the in-plane direction of the magnetic coating film is 0 ° and the vertical direction is 90 °, the low angle means about 0 ° to 30 °). In addition to the above, the inclination of a pair of magnets disposed across the medium needs to be changed in accordance with a desired angle, resulting in a problem that the apparatus becomes large. In addition, since the magnet is used in an inclined state, there is a problem that a region in which the magnetic powder is oriented substantially becomes narrow.

Therefore, the present invention has been proposed in view of such conventional circumstances, and an object of the present invention is to provide an oblique orientation method capable of easily generating a magnetic field on a low angle side.

Further, the present invention facilitates the generation of the magnetic field on the low angle side, and can control the inclination of the magnetic field generated in the oblique direction with high accuracy over a wide range, and can reduce the size of the device and further reduce the magnetic powder. An object of the present invention is to provide an oblique alignment device capable of securing a region for alignment.

[Means for solving the problem]

The oblique alignment method of the present invention is proposed to achieve the above object, and simultaneously applies a magnetic field component substantially perpendicular to the magnetic coating surface and a magnetic field component substantially parallel to the magnetic coating surface,
The magnetic powder contained in the magnetic coating is oriented obliquely to the magnetic coating surface.

Further, the oblique orientation device of the present invention has a first magnet for applying a magnetic field component substantially perpendicular to the magnetic coating surface, and a second magnet for applying a magnetic field component substantially parallel to the magnetic coating surface. The magnetic powders contained in the magnetic coating film are oriented obliquely to the surface of the magnetic coating film by the cooperation of the magnets.

In the present invention, a magnetic field component substantially perpendicular to the magnetic coating surface and a magnetic field component substantially parallel to the magnetic coating surface are simultaneously applied, and the sum of the vectors of these magnetic field components causes the magnetic component in a direction oblique to the magnetic coating surface. A magnetic field is generated, and the magnetic powder in the magnetic coating is oriented obliquely with respect to the surface of the magnetic coating by the magnetic field in the oblique direction. Therefore, a magnet that applies a magnetic field component substantially perpendicular to the magnetic coating surface and a magnet that applies a magnetic field component substantially parallel to the magnetic coating surface are used in combination as the orientation device. The position of these two magnets is determined by the fact that a magnetic field must be generated obliquely to the magnetic coating surface by at least the sum of the vector of the substantially perpendicular magnetic field component and the substantially parallel magnetic field component. It is desirable that a magnet for applying a parallel magnetic field component is disposed between the magnets for applying the components. Of course, on the contrary, a magnet for applying a perpendicular magnetic field component may be arranged between magnets for applying a parallel magnetic field component.

For example, an electromagnet or a permanent magnet can be used as the magnet for applying a magnetic field component substantially perpendicular to the surface of the magnetic coating film.
On the other hand, as a magnet that applies a magnetic field component substantially parallel to the magnetic coating surface, a solenoid coil, a permanent magnet, or the like can be used.

Further, the magnetic field recording medium to which the present invention is applied is a coating type magnetic recording medium, and any conventionally known magnetic powder can be used as the magnetic powder in the magnetic coating film applied on the non-magnetic support. It is not limited. To illustrate,
γ-Fe ₂ O ₃ , Fe ₃ O ₄ , Belt compound of γ-Fe ₂ O ₃ and Fe ₃ O ₄ , Co-containing γ-Fe ₂ O ₃ , Co-containing Fe ₃ O ₄ , Co-containing γ
A beltride compound of Fe ₂ O ₃ and Fe ₃ O ₄ , an oxide of CrO ₂ containing one or more metal elements, such as Te, Sb, Fe, Bi, Fe, Co, Ni, etc. Metal, Fe-Co, Fe-Ni, Fe-Co
-Ni, Fe-Co-B, Fe-Co-Cr-B, Mn-Bi, Mn-Al, Fe-Co
Alloys such as -V and needle-like fine particles such as iron nitride.

[Action]

In the present invention, when a magnetic field component substantially perpendicular to the magnetic coating surface and a magnetic field component substantially parallel to the magnetic coating surface are simultaneously applied,
The sum of the vectors of these magnetic field components generates a magnetic field oblique to the magnetic coating surface.

Further, in the present invention, the first magnet that applies a magnetic field component substantially perpendicular to the magnetic coating surface and the second magnet that applies a magnetic field component substantially parallel to the magnetic coating surface cooperate with the magnetic coating film. The magnetic powder contained in the magnet is oriented obliquely to the surface of the magnetic coating film. Therefore, if the intensity of the magnetic field generated by each of these magnets is appropriately selected and generated, the inclination of the magnetic field in the oblique direction becomes Changes from the low angle side to the high angle side or vice versa.

〔Example〕

Hereinafter, specific examples of the oblique alignment method and the oblique alignment apparatus to which the present invention is applied will be described.

First, the oblique alignment device of the present embodiment will be described with reference to the drawings.

As shown in FIG. 1, the oblique orientation device of the present embodiment includes first magnets (2) and (3) vertically arranged with a long magnetic recording medium (1) interposed therebetween. It comprises a second magnet (4) disposed between the first magnets (2) and (3).

The first magnets (2) and (3) are composed of a pair of magnetic cores (5) that are orthogonally arranged to face the magnetic coating surface (1a) and the back surface (1b) of the magnetic recording medium (1), respectively. ),
(6). These magnetic cores (5), (6)
Consists of, for example, an iron core whose side shape is rectangular,
The length of the facing surface is at least such that the orientation of the magnetic powder can be completed during the passage therebetween. A predetermined number of coils (7) and (8) are wound around the magnetic cores (5) and (6), respectively. A DC power supply (9) is provided as a common power supply at both ends of the coils (7) and (8). It is connected. The DC power supply (9) may be separately connected to the coils (7) and (8) wound around the magnetic cores (5) and (6). As a result, a magnetic field substantially perpendicular to the magnetic coating surface (1a) is generated between the pair of magnetic cores (5) and (6) by the current supplied from the DC power supply (9). In this embodiment, a magnetic field is generated from one magnet (3) disposed on the back surface (1b) of the medium to the other magnet (2) disposed opposite thereto.

On the other hand, the second magnet (4) is composed of a solenoid coil (10) that is wound a plurality of times so that the coil extends in the direction of travel of the magnetic recording medium (the direction of arrow a in the figure). The solenoid coil (10) is disposed between the first magnets (2) and (3), and the extending direction of the coil is orthogonal to the first magnets (2) and (3). . The solenoid coil (10) is sized to allow the magnetic recording medium (1) to run inside it, and the coil (10) is similar to the first magnets (2) and (3). The length is set so that the orientation of the magnetic powder can be completed while traveling through the inside. Further, the solenoid coil (10) is provided at both ends of the solenoid coil (10).
A DC power supply (11) for supplying a DC current is connected. Therefore, when a current of a predetermined magnitude is supplied to the solenoid coil (10), a magnetic field is generated in the direction of the central axis of the solenoid coil (10), that is, substantially parallel to the magnetic coating surface (1a). In this embodiment, a magnetic field heading in the direction in which the magnetic recording medium runs is generated.

In the oblique orientation device configured as described above, the first magnets (2) and (3) and the second magnet (4) simultaneously apply a magnetic field substantially perpendicular to the magnetic coating surface (1a) and the magnetic coating surface. When generating the substantially parallel magnetic field (1a), as shown in FIG. 2, with respect to the magnetic coating film surface as the sum of these vertical magnetic field vector components H ₁ and magnetic field components parallel H ₂ (1a) magnetic field H ₃ generated in an oblique direction. This oblique magnetic field H ₃
Of the magnetic coating surface (1a) and the magnetic field in the oblique direction
Angle θ] with H ₃ changes substantially perpendicular magnetic field components H ₁ magnitude magnetic coated surface (1a), by approximately the magnitude of the magnetic field component parallel H ₂ in the magnetic coating film surface (1a). That is, if the magnetic field component H ₁ perpendicular to the magnetic coating surface (1a) is made larger than the magnetic field component H ₂ parallel to the magnetic coating surface (1a), the oblique magnetic field H generated as the sum of these vectors The inclination of ₃ becomes big. That is, it is inclined in a direction perpendicular to the magnetic coating surface (1a). Conversely, by increasing the magnetic coated surface substantially parallel magnetic field component between H ₂ (1a) with respect to a substantially perpendicular magnetic field component H ₁ in the magnetic coating film surface (1a), the magnetic field H ₃ in an oblique direction in turn The inclination becomes small, and it inclines in a direction parallel to the magnetic coating surface (1a).

Therefore, according to the device of the present embodiment, if the magnitude of the current supplied to the first magnets (2) and (3) and the second magnet (4) is appropriately selected and supplied, the magnetic field in each direction is obtained. You can change the size of the components, as a result, it becomes possible to widely change over the inclination of the magnetic field H ₃ in an oblique direction from the lower angle side to the high angle side. Of course, these first
Magnets (2), (3) and second magnet (4)
Changing the direction of the current supplied to, if changing the magnitude of the current supplied to each, the inclination of the magnetic field H ₃ in an oblique direction 0 ° -
It can be changed in a range of 360 degrees.

Further, in the apparatus of the present embodiment, it is possible to change the inclination of the magnetic field H ₃ in an oblique direction without moving the device, downsizing of the apparatus, moreover take wide region obliquely oriented.

In the present invention, the first magnet (2),
There is no need to be limited to the above example as long as a magnetic field can be generated in an oblique direction by the sum of vectors of magnetic field components generated by (3) and the second magnet (4). For example, the first magnets (2) and (3) may be accommodated in a second magnet (4) for applying a magnetic field component substantially parallel to the magnetic coating surface (1a), that is, a solenoid coil (10). It may be. Of course, also in this case, a magnetic field oblique to the magnetic coating surface (1a) can be similarly generated.

Next, the oblique alignment method of this embodiment will be described. In this embodiment, an example in which the magnetic powder is obliquely oriented with respect to the surface of the magnetic coating film using the above oblique orientation apparatus will be described.

First, a current of a predetermined magnitude is supplied to each of the first magnets (2) and (3) and the second magnet (4) to generate a magnetic field substantially perpendicular to the magnetic coating surface (1a). Surface (1a)
Generates a magnetic field substantially parallel to.

Next, when the magnetic recording medium (1) on which the magnetic coating film containing the magnetic powder is formed is in a flowable state before the magnetic coating film has been dried, the solenoid of the second magnet (4) is used. It is inserted into the coil (10) and is run in the direction a in FIG.

Then, the magnetic powder is subjected to magnetic fields of both of these magnetic coated surface (1a) substantially perpendicular magnetic field component and H ₁ and the magnetic coated surface (1a) and substantially parallel to the magnetic field component H _2. As a result, the magnetic powder by the sum of these vertical magnetic field components H ₁ and magnetic field components parallel H ₂ vector is oriented to the combined vector direction. In the present embodiment, the magnet is oriented obliquely toward the magnet (2) disposed on the magnetic coating surface (1a) according to the inclination of the angle θ formed with the magnetic coating surface (1a).

Thereafter, if drying is performed in a series of steps, an obliquely oriented magnetic recording medium is obtained.

Next, the oblique orientation was actually performed using the above-described oblique orientation apparatus, thereby producing a magnetic recording medium.

Experimental Example Composition of magnetic paint 100 parts by weight Fe 10 parts by weight Polyurethane resin 10 parts by weight Vinyl resin 10 parts by weight Alumina 6 parts by weight Carbon 3 parts by weight Hardener (brand name Coronate L) 4 parts by weight Solvent 250 parts by weight After mixing for 48 hours, a magnetic coating film was formed through a filter. This magnetic paint was applied to a polyethylene terephthalate film by a roll coater, and was obliquely oriented using the oblique orientation apparatus shown in FIG. Then, after applying a calendar treatment, it is cured,
Further, a back coat layer was formed and cut into a predetermined width to obtain a sample tape.

In this experimental example, the magnetic powder was oriented at an angle of 30 degrees in the vertical direction from the surface of the magnetic coating film.

Comparative Example 1 The same magnetic paint as that used in the experimental example was used, and the tape coated with the magnetic paint was oriented in the longitudinal direction.

The longitudinal orientation was performed by applying a magnetic field by an electromagnet in the longitudinal direction of the medium.

Comparative Example 2 The same magnetic paint as that used in the experimental example was used, and the tape coated with the magnetic paint was vertically oriented.

The vertical orientation was performed by applying a magnetic field generated by supplying a direct current to a coil wound around a permanent magnet in a direction perpendicular to the medium. Note that the intensity of the vertical magnetic field was set to 5 kgauss.

Then, the electromagnetic conversion characteristics (reproduced output characteristics) of the sample tapes obtained in the above experimental example, comparative examples 1 and 2 were measured. FIG. 3 shows the results. In FIG. 3, the solid line indicates the experimental example, the broken line indicates the comparative example 1, and the dashed line indicates the comparative example 2, respectively.

As can be seen from the results, the sample tape having the longitudinal orientation has excellent reproduction output characteristics in a long wavelength region, but has a deteriorated reproduction output characteristic in a short wavelength region. On the other hand, the sample tape which has been subjected to the vertical alignment has excellent reproduction output characteristics in the short wavelength region, but shows deterioration in the reproduction output characteristics in the long wavelength region. On the other hand, it can be seen that in the sample tape subjected to the oblique orientation, a high output is obtained over a wider range over a shorter wavelength range than a longer wavelength range. Therefore, by performing the oblique orientation, it is possible to increase the reproduction output characteristics from a long wavelength region to a short wavelength region, and to improve the C / N ratio.

〔The invention's effect〕

As is clear from the above description, in the method of the present invention, a magnetic field component substantially perpendicular to the magnetic coating surface and a magnetic field component substantially parallel to the magnetic coating surface are simultaneously applied. The magnetic powder contained in the magnetic coating film can be oriented obliquely with respect to the surface of the magnetic coating film by the sum of the vectors.

If the magnitude of these magnetic field components is appropriately selected and generated, a magnetic field on the low angle side can be easily generated.

Further, in the apparatus of the present invention, an oblique magnetic field is generated by cooperating with a magnet for applying a magnetic field component substantially perpendicular to the magnetic coating surface and a magnet for applying a magnetic field component substantially parallel to the magnetic coating surface. Therefore, if the magnitudes of the two magnetic field components are appropriately selected and generated, the inclination of the magnetic field in the oblique direction can be controlled more accurately from the low angle side to the high angle side.

Further, in the apparatus according to the present invention, the inclination of the magnetic field in the oblique direction can be changed only by changing the magnitude of each magnetic field component, so that it is not necessary to move the apparatus every time.
Therefore, the size of the device itself can be reduced, and a region for oblique orientation can be sufficiently secured.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing one embodiment of an oblique orientation device to which the present invention is applied, and FIG. 2 is a schematic diagram showing a state of a magnetic field generated by the device. FIG. 3 is a characteristic diagram showing the reproduction output dependency on the recording wavelength. 1 ... magnetic recording medium 2,3 ... first magnet 4 ... second magnet

Claims (2)

(57) [Claims] A magnetic field component substantially perpendicular to the magnetic coating surface and a magnetic field component substantially parallel to the magnetic coating surface are simultaneously applied, and the magnetic powder contained in the magnetic coating film is inclined with respect to the magnetic coating surface. An oblique alignment method, which comprises: A first magnet for applying a magnetic field component substantially perpendicular to the surface of the magnetic coating film, and a second magnet for applying a magnetic field component substantially parallel to the surface of the magnetic coating film. An oblique alignment device, wherein a magnetic powder contained in the magnetic coating film is aligned obliquely to a surface of the magnetic coating film by cooperation.