JPH10134351A - Production of magnetic recording medium and apparatus for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a magnetic recording medium having excellent traveling stability by previously cooling a nonmagnetic base in the position before a guiding member at the time of forming a magnetic layer consisting of a magnetic metallic thin film on the nonmagnetic base 2 on the guiding member under the condition effecting with heat. SOLUTION: A device 11 for cooling the nonmagnetic base 2 in the position before the rotary guiding member 5 is disposed before the formation of the magnetic layer consisting of the magnetic metallic thin film. For example, a cooler of a heat exchange type for which a compressor is used is so arranged as to cover a supply roller 3 for delivering the base 2. The cooling of the base 2 together with the roll is possible and the sufficient and uniform cooling of the base 2 before the formation of the magnetic metallic thin film with a magnetic metallic thin material 7 heated and evaporated by irradiation with an electron beam EB on the member 5 in a vapor deposition region VD is possible. The cooled base 2 is cooled adequately and is subjected to vapor deposition before its overall thickness arrives at the region VD. As a result, the good tape which may be decreased in the temp. differences between the vapor deposition surface and other surface of the base 2 and is free from internal stresses is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a so-called metal magnetic thin film type magnetic recording medium in which a magnetic layer made of a metal magnetic thin film is provided on a nonmagnetic support (for example, a high band 8 mm video tape, The present invention relates to a method for manufacturing a magnetic tape or a magnetic disk suitable for reproducing a short-wavelength magnetic recording signal (high-density recording) such as a digital VTR (video tape recorder) and an apparatus for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, as a magnetic recording medium, a powder magnetic material such as an oxide magnetic powder or an alloy magnetic powder has been used as an organic binder such as a vinyl chloride-vinyl acetate copolymer, a polyester resin, a urethane resin and a polyurethane resin. (Binder) A magnetic paint is prepared by dispersing the magnetic paint in a binder, coating the magnetic paint on a non-magnetic support such as a polyester film, and drying the magnetic paint. .

On the other hand, in response to a demand for high-density magnetic recording in recording, video recording, information processing, and the like, for example, a demand for higher image quality, Co-Ni alloy, Co-Cr alloy, Co-
A so-called metal magnetic thin film type magnetic material in which a metal magnetic material such as O is directly applied on a non-magnetic support such as a polyester film by plating or vacuum thin film forming means (vacuum vapor deposition method, sputtering method, ion plating method, etc.) Recording media have attracted attention and have been put to practical use.

The metal magnetic thin film type magnetic recording medium is excellent in coercive force, squareness ratio, etc., is excellent not only in electromagnetic conversion characteristics at short wavelengths, but also can make the thickness of the magnetic layer extremely thin (thinning). In addition, the recording material has extremely low recording demagnetization and thickness loss during reproduction, and it is not necessary to mix a nonmagnetic material such as an organic binder in the magnetic layer, so that the packing density of the magnetic material can be increased. It has a number of advantages, such as no waste liquid treatment problems.

[0005] As described above, the magnetic recording medium of the metal magnetic thin film type has characteristics that are superior to those of the coating type magnetic recording medium. Among them, the vapor deposition tape on which the magnetic layer is formed by the vacuum vapor deposition method has a high performance. For production efficiency and stable characteristics,
It has already been put to practical use as a high-band 8 mm video tape, digital microtape (NT tape) and the like.

Conventionally, as a means for producing such a vapor deposition tape, a physical film forming method (PVD: Physical Vapor
Deposition) is used, and in particular, the vacuum evaporation method is often performed by a vacuum evaporation apparatus configured as follows.

That is, in a vacuum deposition apparatus, a feed roll for supplying a non-magnetic support and a take-up roll for winding the non-magnetic support after the deposition are provided in a vacuum chamber in which the inside is in a vacuum state. The film-shaped non-magnetic support is made to travel at a predetermined speed from the feed roll to the take-up roll, and a cooling can having a diameter larger than the diameter of each roll is rotatable in the middle of the travel path. Is provided. This cooling can cools the non-magnetic support by cooling means (coolant) disposed inside the can when depositing the metallic magnetic material while guiding the non-magnetic support on the peripheral surface, and deforms due to a rise in temperature during deposition. , Breakage and the like can be suppressed.

Further, a crucible as a vapor deposition source is disposed in the vacuum chamber, and an electron gun for heating and evaporating the metal magnetic material contained in the crucible is mounted. The electron beam emitted from this electron gun is applied to the metal magnetic material in the crucible, and the melted and evaporated metal magnetic material adheres as a continuous magnetic thin film on the non-magnetic support running at a constant speed on the peripheral surface of the cooling can. I do.

However, when the non-magnetic support is cooled by the cooling can in this manner, the non-magnetic support is exposed to a high temperature on the deposition surface side, and the opposite contact surface with the cooling can is cooled. The temperature difference between one surface (evaporation surface) side and the other surface side of the magnetic support becomes very large. in this case,
Although a predetermined tension is applied in the length direction of the film-shaped non-magnetic support, there is no tension in the width direction, so that the following problem is likely to occur.

That is, as shown in FIG.
When the vapor deposition is performed while guiding the nonmagnetic support 12 in the direction of the arrow Z on the peripheral surface, the internal stress is isotropic inside the nonmagnetic support 12 in a normal state where the vapor deposition is not performed. Is almost zero in the width direction of the non-magnetic support,
As shown in (A), when the metal magnetic material 7 is deposited, the surface layer of the nonmagnetic support 12 is heated by the thermal load and the growth of the magnetic material in the process of depositing the metal magnetic material on the support. (Evaporation surface of magnetic layer) A large difference occurs in the internal stress 40 between the 12A side and the inner layer 12B side as indicated by an arrow (vector).

As a result, as shown in FIG. 4 (B), when viewed from the surface layer side 12A in the width direction where no tension is present in the non-magnetic support 12, from the edges at both ends of the non-magnetic support 12 toward the center. Has an internal stress 40 corresponding to the above difference. For this reason, as shown in FIG. 5A, when the nonmagnetic support 12 is formed into a tape, a shape distortion called so-called normal cupping which curves toward the magnetic layer often occurs.

As shown in FIG. 5, plus (positive) cupping (A) indicates a state in which the magnetic tape 43 is curved toward the magnetic surface side, and indicates a minus state if the magnetic tape 43 is curved in a direction opposite to the magnetic layer. (Negative) Cupping (B)
Similar). The dashed line in the figure indicates the case where cupping is remarkable. Further, the cupping value d is indicated by a positive value at the time of plus (positive) cupping shown in (A), and is indicated by a negative value at the time of minus (negative) cupping shown in (B) (hereinafter the same). .

In the ordinary vapor deposition method, the temperature difference between one surface and the other surface of the film-shaped non-magnetic support is very large, and a large difference occurs in the internal stress. The shape of the magnetic recording medium before (cutting) is distorted and becomes a cupping state, and even if this is slit (cut) to the actual tape width (for example, 8 mm width),
Similar distortion remains, and the tape may be cupped as shown in FIG.

Next, a problem when cupping (particularly normal cupping) occurs will be described.

At present, the main systems for recording and / or reproducing (recording / reproducing) a magnetic recording medium include a fixed head recording / reproducing system represented by a compact audio cassette, and
There is a rotary head recording / reproducing system typified by a video tape recorder (VTR). Among them, the rotary head recording / reproducing system is mainly used because of the necessity of high-density recording. In this case, as schematically shown in FIG. 6A, in order to reduce the spacing between the magnetic layer (metal magnetic thin film) 7 of the magnetic tape 43 and the circular drum (the fixed drum 45 and the rotating drum 46), Rotating drum 4 with magnetic head 47
6 (normally, in the case of a magnetic head for an 8 mm video tape recorder, the amount of protrusion L is about 2
(0 μm) to increase the surface pressure between the magnetic tape and the magnetic head 47.

When the magnetic recording medium (especially the magnetic tape 43: the same applies hereinafter) has a flat shape without cupping,
As shown in FIG. 7A, the hatched portion (track area) 43A actually recorded / reproduced is usually narrower than the tape width, so that the magnetic head 47 contacts both edge portions 43B in the width direction of the tape 43. Should not. However, as the cupping becomes larger, the FIG.
, The apparent tape width becomes smaller.

As shown in FIGS. 8 and 9, when the cupping is increased, when the tape 43 running in the direction of the arrow X is loaded onto the drum via the tape regulating guide 48, the arrow Y on the fixed drum 45 is used. The edge portion 43B of the tape 43 may be caught on the magnetic head 47 protruding from the rotating drum 46 rotating in the direction, thereby causing damage such as biting.

As shown in FIG. 6B, when cupping does not occur (that is, when the tape is flat), the magnetic head 47 and the medium 43 come into contact with an appropriate surface pressure.

However, when the medium 43 is positively cupped as shown in FIG. 6C, the medium 43 is flattened to some extent by the guide pins and the like, but the surface pressure is reduced at the central portion of the medium 43 and the head 43 is hit. The surface pressure is increased at the edge portion, but the edge portion is easily caught at the time of loading as described above. Then, the tape is easily shifted to the lower end surface of the tape guide groove of the drum or to one side of the tape regulating surface of the guide pin.

FIG. 6D shows a case in which the medium 43 is negatively cupped. The surface pressure increases at the center portion of the medium 43 and decreases at the edge portion. No more problems.

When such cupping occurs, the contact between the medium and the head is degraded during the running of the magnetic tape, and a loss in spacing during recording / reproducing (spacing loss) may occur. However, minus cupping has fewer problems than plus cupping.

The above-mentioned decrease in surface pressure is caused by a so-called poor contact at the entrance or exit in the sliding contact area between the drum and the medium. As a result, even if the magnetic head slides on a predetermined track, the output (RF output) may be reduced in a portion where the head contact is weak as shown in FIG.

That is, the entrance of the sliding contact area between the drum and the medium,
If the hit at the exit is poor, the evaluation value (B / A × 100) of the hit characteristic of the RF waveform shown in Expression (1) becomes small. The larger this value is, the better it can be determined that the hit characteristics are excellent. If the hit characteristics are excellent, the contact between the medium and the magnetic head is improved, and the magnetic characteristics and electromagnetic conversion characteristics are improved. It is thought that.

Further, in a cassette such as an 8 mm video tape or a digital video tape in which a medium is accommodated between double lids on the front lid side, the lid portion and the edge portion of the medium where the cupping has occurred are formed. The medium may be damaged due to easy contact and biting.

Further, in the case of using the ordinary vacuum evaporation apparatus in the production of the above-mentioned metal thin film type medium, a cooling device for passing a cooling medium is provided inside the cooling can 5, so that the structure inside the cooling can is reduced. It is complicated and its production is costly. In addition, since the magnetic material 7 is deposited while cooling the nonmagnetic support 12 with the cooling can 5, the deposition rate is restricted by the cooling rate, and the deposition rate is limited, and there is a problem in productivity.

[0026]

SUMMARY OF THE INVENTION The present invention has been made in view of such conventional circumstances, and has as its object to reduce or eliminate cupping, to achieve excellent head stability, running stability, and productivity. An object of the present invention is to provide an improved method and apparatus for manufacturing a magnetic recording medium.

[0027]

That is, according to the present invention, while guiding a non-magnetic support on a guide member such as a rotary guide member, a metal magnetic material is applied to the non-magnetic support in a film formation region on the guide member. In forming a magnetic layer composed of a thin film under the action of heat, a method for manufacturing a magnetic recording medium (hereinafter, referred to as a method for manufacturing a magnetic recording medium, wherein the non-magnetic support is cooled before the guide member.
This is referred to as the production method of the present invention. ).

According to the present invention, in order to carry out the manufacturing method of the present invention, a guide member for guiding a non-magnetic support and a magnetic layer made of a metal magnetic thin film are formed on the non-magnetic support under the action of heat. A magnetic recording medium manufacturing apparatus (hereinafter referred to as a manufacturing apparatus according to the present invention) including: a film forming region on the guide member to be formed; and a cooling unit that cools the nonmagnetic support in advance in front of the guide member. ) Are also provided.

According to the manufacturing method and the manufacturing apparatus of the present invention,
Since the non-magnetic support is previously cooled before the guide member (which corresponds to a conventional cooling can), the non-magnetic support is formed during film formation under the action of heat such as vacuum evaporation. The support can be maintained at an appropriate temperature to maintain its thermal stability. When a metal magnetic thin film is formed on the guide member under the action of heat, one surface of the non-magnetic support (the surface on which the magnetic layer is formed) is formed. )
A large temperature difference as described above can be prevented from being generated between the side and the other surface (guide member) side, and the formation of the magnetic layer of the non-magnetic support during the deposition of the metallic magnetic material The difference in internal stress between the surface side and the other surface side is reduced. As a result, the curvature due to the shape distortion of the nonmagnetic support is reduced, and cupping can be reduced. That is, it is possible to provide a magnetic recording medium having little or no cupping, excellent shape, and excellent head contact and running stability.

Further, since there is no need to provide a cooling device inside the guide member, the structure of the device having the guide member can be simplified, for example, in film formation by a vacuum deposition method or the like, and the device itself becomes inexpensive. In addition, since the non-magnetic support is cooled before forming the magnetic layer made of the metal magnetic thin film (that is, in front of the guide member) without cooling with the guide member,
The formation rate of the magnetic layer can be increased, and a manufacturing method excellent in productivity can be provided.

In the manufacturing method and the manufacturing apparatus of the present invention,
The position for cooling the non-magnetic support may be any position as long as it is in front of the guide member (that is, upstream of the guide member in the movement path of the non-magnetic support). Is not particularly limited.

Here, the above-mentioned cupping refers to a state in which the non-magnetic support is curved in the direction toward the magnetic surface or in the direction opposite to the magnetic layer, and as shown in FIG. The state of being curved in the positive direction is called plus (positive) cupping, and the state of being curved in the direction opposite to the magnetic surface is called minus (negative) cupping. Indicates a positive value and negative (negative) cupping indicates a negative value.

The above-mentioned guide member is a guide member which guides and runs the non-magnetic support in order to continuously form a magnetic layer made of a metal magnetic thin film on the non-magnetic support. The member is mainly a rotary type, but need not be a rotary type. The above "on the guide member" is not limited to the lower surface of the guide member but may be on another surface.

[0034]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a manufacturing method and a manufacturing apparatus according to the present invention, a non-magnetic support is heated by evaporating a ferromagnetic material under vacuum and depositing the ferromagnetic material on the non-magnetic support. It is preferable that a magnetic layer made of a metal magnetic thin film is formed thereon.

An evaporation source on which the material for the magnetic layer is disposed;
A supply roll for sending out the non-magnetic support, a winding roll for winding the non-magnetic support after the vapor deposition, and a method for performing the vapor deposition while guiding the non-magnetic support between the supply roll and the winding roll. In the vacuum chamber where the rotary guide member is disposed, the non-magnetic support is not cooled by the rotary guide member, but is cooled in front of the rotary guide member (in particular, in the supply roll, 40 ° C ~
It is desirable to have a non-magnetic support cooling means capable of cooling to a temperature range of + 20 ° C.).

FIG. 1 is a schematic sectional view showing an example of a manufacturing apparatus of a metal magnetic thin film type magnetic recording medium usable in the present invention, in particular, an example of a vacuum evaporation apparatus.

In this vacuum evaporation apparatus, a supply roll 3 for rotating a clockwise direction in the drawing to feed a non-magnetic support 2 into a vacuum chamber (evaporator main body) 1 in which the inside is in a vacuum state; A take-up roll 4 is provided, which rotates clockwise in the figure to take up the non-magnetic support after vapor deposition, and the film-like non-magnetic support 2 runs from the supply roll 3 to the take-up roll 4 sequentially. It has been made like that.

Then, from the supply roll 3 to the winding roll 4
In the middle of the path along which the non-magnetic support 2 travels, a rotary guide member 5 having a diameter larger than each of the rolls 3 and 4 is provided. The rotary guide member 5 is configured to rotate in the counterclockwise direction in the drawing, so that the non-magnetic support member 2 is wound on the peripheral surface from the upper left side, and pulled out from the lower side toward the take-up roll 4. Is provided.

Each of the supply roll 3, the take-up roll 4, and the rotary guide member 5 has a cylindrical shape having a length substantially equal to the width of the nonmagnetic support 2.

Therefore, the non-magnetic support 2 is
And sequentially passes over the peripheral surface of the rotary guide member 5 and is taken up by the take-up roll 4.

A crucible 6 is provided in the vacuum chamber 1 below the deposition region VD of the rotary guide member 5, and a ferromagnetic metal material (metal magnetic material) 7 is accommodated in the crucible 6. . The crucible 6 is provided at substantially the same length as the rotary guide member 5 along the rotation axis direction of the rotary guide member 5.

On the other hand, an electron beam generator 8 for heating and evaporating the metallic magnetic material 7 accommodated in the crucible 6 is attached to the wall of the vacuum chamber 1. The electron beam generator 8 irradiates the metal magnetic material 7 in the crucible 6 with an electron beam EB emitted from the electron beam generator 8 via a focusing device 9 and a scanning device 10 using a magnetic field. It is arranged in such a position.

The metal magnetic material 7 heated and evaporated by the irradiation of the electron beam EB from the electron beam generator 8
Is deposited on the non-magnetic support 2 traveling at a constant speed on the peripheral surface of the rotary guide member 5 at a predetermined angle (here, obliquely) to form a metal magnetic thin film as a magnetic layer.

Power (output) of the electron beam generator 8
Is preferably set appropriately in accordance with the deposition rate, but is about 8 k as a power capable of producing a normal deposition tape.
More than W, for example, 12 kW is required. However, this value varies depending on the structure of the apparatus, the evaporation source, and the like, and is not limited thereto.

Further, when depositing such a metal magnetic thin film, the non-magnetic support 2 is supplied through an oxygen gas inlet (not shown).
Oxygen gas is supplied to the surface of the metal magnetic thin film, thereby improving the magnetic properties, durability and weather resistance of the metal magnetic thin film.

However, in order to heat the evaporation source, known means such as resistance heating means, high-frequency heating means, and laser heating means can be used in addition to the means for heating with an electron beam as described above.

It should be noted that in the vacuum deposition apparatus shown in FIG. 1, before providing a magnetic layer composed of a metal magnetic thin film, that is,
A device (nonmagnetic support cooling means) 11 for cooling the nonmagnetic support 2 in front of the rotary guide member 5, for example, a heat exchange type cooler using a compressor, feeds out the nonmagnetic support 2 That is, it is arranged so as to cover the supply roll 3 in the roll portion and to be able to send out the nonmagnetic support 2.

By arranging the cooling device 11 so as to cover the supply roll portion, the non-magnetic support 2 (raw material) can be cooled together with the roll, and the rotary guide member 5 can be cooled in the vapor deposition region VD. It is possible to cool the nonmagnetic support 2 sufficiently and uniformly before forming the metal magnetic thin film thereon. The cooled non-magnetic support 2 is appropriately cooled until its entire thickness reaches the deposition region VD, and is subjected to deposition.

The cooling of the non-magnetic support 2 may be performed before the magnetic layer made of a metal magnetic thin film is provided, that is, before the rotary guide member 5. In the rear position, as shown by a dashed line 11a, a cooler (nonmagnetic support cooling means) similar to the above, which cools the nonmagnetic support 2, may be arranged so that the nonmagnetic support 2 can pass through. Good.

In such an apparatus, the nonmagnetic support 2 is cooled in advance by a cooler, instead of cooling the nonmagnetic support from the surface opposite to the surface on which the metal magnetic material is deposited as in a conventional cooling can. Since cooling is performed at 11 or 11a, a vapor deposition film can be formed in the vapor deposition region VD without damaging the nonmagnetic support 11 due to vapor deposition heat, and one surface 2A (vapor deposition surface) of the nonmagnetic support 2 and The temperature difference with the other surface 2B (the surface of the rotary guide member 5) can be reduced.

As a result, as shown in FIG. 2, the difference in the internal stress 20 between the two sides, which is the cause of the cupping, is reduced, or the stress is almost uniform, so that the cupping is extremely small or not at all. It is believed that no magnetic recording medium can be obtained. FIG. 5 shows a state in which such cupping is significantly reduced by broken lines. Although this is extremely effective for plus cupping, problems such as plus cupping hardly occur for minus cupping as described with reference to FIG.

Further, in the vacuum deposition apparatus shown in FIG. 1, since no cooling device is provided inside the rotary guide member 5, the structure of the device is simplified and the device itself can be manufactured at low cost. Further, since the non-magnetic support cooling means 11 is provided in front of the rotary guide member 5, the deposition rate of the magnetic layer can be increased as compared with the case where a conventional cooling can is used.

That is, in the conventional apparatus, the deposition rate is about 50
In contrast to the limit of about m / min, the above-described apparatus of the present invention can increase the deposition rate to about 100 m / min.

Further, the cooling temperature in the device (nonmagnetic support cooling means) 11 for cooling the nonmagnetic support is from -40 ° C.
It is preferable that the temperature be in the range of + 20 ° C.

As shown in FIG. 3, the cooling temperature is -40 ° C.
If the temperature is within the range of + 20 ° C., the cupping value of the manufactured magnetic recording medium (particularly, magnetic tape) may be nearly zero, and jamming and edge damage are less likely to occur even during loading. The cooling temperature is between -30 ° C and ±
More preferably, the temperature is set to 0 ° C. Further, as the cooling means, a conventionally known cooling means such as a compressor can be used.

The magnetic recording medium to which the present invention is applied is a so-called metal magnetic thin film deposition in which a metal magnetic thin film is formed as a magnetic layer on a nonmagnetic support made of a nonmagnetic material by vacuum deposition as a vacuum thin film forming means. Type magnetic recording medium.

The metal magnetic thin film is formed as a continuous film by a vacuum deposition method or the like, and includes Fe, Co, N
i and other ferromagnetic metals, Co-Ni alloys, Co-Ni-P
a metal magnetic film for in-plane magnetization recording, such as a t-based alloy, an Fe-Co-Ni-based alloy, an Fe-Ni-B-based alloy, an Fe-Co-B-based alloy, or an Fe-Co-Ni-B-based alloy; , Co-
A metal magnetic thin film for perpendicular magnetization recording such as a Cr-based alloy thin film and a Co-O-based thin film is exemplified.

In particular, in the case of a metal magnetic thin film for in-plane magnetization recording, Bi, Sb, Pb, Sn, G
a, In, Si, Ti, etc. A base film of a low melting point non-magnetic material such as Ti is formed, and a metal magnetic material is vapor-deposited or sputtered from a vertical direction. It may be made to diffuse and eliminate orientation to secure in-plane isotropy and improve coercive force.

In the magnetic recording medium (especially a magnetic tape) to which the present invention is applied, a metal magnetic thin film is formed on a non-magnetic support by a physical film forming method (especially a vapor deposition method). A top coat layer may be formed on the thin film, and a back coat layer may be formed on the back surface of the non-magnetic support. The raw material of the magnetic recording medium having these films and layers is reduced to a predetermined size (for example, 8 mm width). It is manufactured by cutting.

Examples of the nonmagnetic support include a polymer support formed of a polymer material represented by polyesters, polyolefins, cellulose derivatives, vinyl resins, polyimides, polyamides, polycarbonates, and the like. No. The form of the nonmagnetic support may be any of a film, a tape, a sheet, a disk, a card, a drum, and the like.

The top coat layer may be composed of a known rust preventive, a lubricant or the like, and the back coat layer may be composed of a known antistatic agent or the like.

[0062]

EXAMPLES The present invention will be described below with reference to specific examples, but the present invention is not limited to the following examples.

In this embodiment, polyethylene terephthalate (PE) was used by using the vacuum evaporation apparatus shown in FIG.
A raw material in which a metal magnetic material 7 made of a Co alloy was formed as a continuous thin film by oblique deposition on a nonmagnetic support 2 made of T) was produced. The thickness of the nonmagnetic support 2 is 7.2 μm,
The thickness of the metal magnetic thin film 7 is 0.5 μm or less (for example, 0.2 μm).
μm) and the deposition angle was in the range of 45 to 90 °.

Then, a carbon black-containing synthetic resin film (0.5 μm thick) was formed as a back coat layer on the raw material.
m), after forming a perfluoropolyether film as a top coat layer, cutting (slitting) to a width of 8 mm;
m sample tape for video.

Further, in the vacuum evaporation apparatus shown in FIG. 1 used in this embodiment, the nonmagnetic support 2 is cooled before the magnetic layer composed of the metal magnetic thin film 7 is deposited on the nonmagnetic support 2. Each sample tape (Examples 1 to 9) was produced by changing the cooling temperature in the device (nonmagnetic support cooling means) 11 in the range of −50 ° C. to + 25 ° C.

The degree of vacuum in the vacuum evaporation apparatus is 10 ⁻³ P
a, the power (output) of the electron beam generator 8 is 12 k
W, the conveying speed of the nonmagnetic support was 50 m / min.

Each of the sample tapes having the above-described configurations (Examples 1 to 9) and a sample tape (Comparative Example 1) manufactured by using a conventional vacuum evaporation apparatus having a cooling can (cooling temperature: -20 ° C.) For the cupping value d (mm)
Was measured. The occurrence of edge damage during loading was also measured. The results are shown in Table 1 below.
And FIG. 3 (however, in FIG.
And Comparative Example 1 was indicated by x).

FIG. 5 shows a state diagram of the obtained sample tape. A sample tape having a larger cupping than the sample tape drawn by a solid line is indicated by a dashed line, and a sample tape having a smaller cupping than the sample tape drawn by a solid line is indicated by a dotted line.

Table 1 カ Cupping value d by the cooling device 11 at the time of loading Cooling temperature (° C) (mm) Situation ─────────────────────────────────── Example 1 + 25-0 .69 With jamming occurred. Example 2 +20 -0.58 No problem. Example 3 +10 -0.40 No problem. Example 4 +0 -0.22 No problem. Example 5-100 No problem. 11 No problem Example 7 -30 +0.20 No problem Example 8 -40 +0.28 No problem Example 9 -50 +0.39 Damage occurred Comparative Example 1 -20 (Conventional cooling +0.40 Damage occurrence Cooling temperature) ────────────────── ────────────────

As is clear from Table 1 and FIG. 3, the cooling temperatures of the sample tapes (Examples 1 to 9) manufactured using the vacuum evaporation apparatus shown in FIG.
With the sample tape in the range of 20 ° C. (Examples 2 to 8), plus cupping is greatly reduced or almost flat, and even if minus cupping is increased, there is not much problem.

On the other hand, the conventional sample tape (comparative example 1) using a cooling can (cooling temperature: -20 ° C.) as a cooling device has a large cupping on the plus side, and also has a magnetic head during loading. Edge damage such as the tape edge getting caught has occurred.

That is, according to the present embodiment, when depositing the magnetic layer made of a metallic magnetic thin film, the non-magnetic support member 2 is cooled in advance in front of the rotary guide member 5, so that the non-magnetic support member is cooled. This shows that the temperature difference between the vapor deposition surface side of the body 2 and the opposite surface side is reduced, the internal stress difference in the non-magnetic support body is reduced, and in particular, plus cupping can be reduced.

The cooling temperature of the device (nonmagnetic support cooling means) 11 for cooling the nonmagnetic support 2 from the sample tapes of Examples 1 to 9 may be in the range of −40 ° C. to + 20 ° C. preferable.

That is, in Example 1, although the sample tape was manufactured at a cooling temperature of + 25 ° C., the cupping became large in the minus direction, so that entanglement or jamming with a guide pin or the like occurred during loading, so-called jamming occurred. Easier to do. Example 9 is a sample tape manufactured at a cooling temperature of -50 ° C. In this example, the sample tape between the deposition side of the metal magnetic thin film on the non-magnetic support and the back side of the non-magnetic support was used. Due to the temperature difference, cupping increases in the plus direction, and edge damage such as the magnetic head and the edge of the magnetic tape being caught during loading is likely to occur. The cooling temperature in the device (nonmagnetic support cooling means) 11 for cooling the nonmagnetic support is -3.
It is understood that it is more preferable that the temperature is in the range of 0 to ± 0 ° C.

In addition to the above-described embodiment, a metal magnetic layer was formed on a non-magnetic support made of polyimide having a thickness of 3 μm and a non-magnetic support made of polyethylene terephthalate having a thickness of 20 μm in the same manner as in the above configuration and operation. When each sample tape on which the thin film was deposited was prepared, the non-magnetic support was cooled in advance in front of the rotary guide member 5 when depositing the magnetic layer composed of the metal magnetic thin film on these sample tapes. As a result, it is possible to reduce the extreme temperature difference between the deposition surface side of the non-magnetic support and the opposite side, and reduce the difference in internal stress in the non-magnetic support. Was reduced or eliminated entirely.

From the above results, a magnetic recording medium (especially a magnetic tape) having good shape characteristics could be obtained in this embodiment.

Although the present invention has been described with reference to the embodiment, the above-described embodiment can be further modified based on the technical idea of the present invention.

For example, the cooling device for the non-magnetic support may be arranged not at the supply roll, but at any location between the metal magnetic thin film deposition area and the supply roll. Also,
The supply roll unit and the cooling device may be provided outside the vacuum evaporation device.

In the case where a non-magnetic support is produced and the metal magnetic thin film is deposited as it is without winding the produced non-magnetic support, before depositing the metal magnetic thin film on the non-magnetic support, The cooling device for the non-magnetic support can be arranged at any position as long as it is located at the front of the rotary guide member and cools the non-magnetic support sufficiently and uniformly.

The cooling device may be variously selected from known devices, and a method of contacting with a cooling gas or a cooling plate may be employed.

In a film forming method other than the vacuum evaporation method (for example, a sprinkling method, an ion plating method, or the like), if heat is applied during the film formation, as described above before the film formation. By pre-cooling the nonmagnetic support at an appropriate temperature, a magnetic recording medium with little or no cupping can be manufactured.

Further, after a magnetic layer made of a metal magnetic thin film is provided on a non-magnetic support, cupping may be corrected in a flat or slightly minus direction by a heat treatment such as a so-called hot roll treatment in which a heat roll is used. Absent.

As the material for the non-magnetic support, the material for the magnetic layer, the material for the top coat layer, and the material for the back coat layer, known materials other than the above-mentioned materials can be used. It is also possible to add known additives to these materials in appropriate amounts.

[0084]

According to the present invention, as described above, since the non-magnetic support is cooled before the guide member, the non-magnetic support is formed during film formation under the action of heat such as vacuum deposition. The body can be kept at an appropriate temperature to maintain its thermal stability, and when forming a metal magnetic thin film on the guide member under the action of heat, one surface of the non-magnetic support (the surface on which the magnetic layer is formed) A large temperature difference as described above can be prevented from being generated between the side and the other surface (guide member) side, and the formation of the magnetic layer of the non-magnetic support during the deposition of the metallic magnetic material The difference in internal stress between the surface side and the other surface side is reduced. As a result, the curvature due to the shape distortion of the nonmagnetic support is reduced, and cupping can be reduced. That is, it is possible to provide a method for manufacturing a magnetic recording medium having little or no cupping, excellent shape, and excellent head contact and running stability.

Further, since it is not necessary to provide a cooling device inside the guide member, the structure of the device having the guide member can be simplified, for example, in film formation by a vacuum evaporation method or the like, and the device itself can be inexpensive. In addition, since the non-magnetic support is cooled before forming the magnetic layer made of the metal magnetic thin film (that is, in front of the guide member) without cooling with the guide member,
The formation rate of the magnetic layer can be increased, and a manufacturing method excellent in productivity can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a vacuum evaporation apparatus that can be used when manufacturing a magnetic recording medium (particularly a magnetic tape: the same applies hereinafter) based on the present invention.

FIG. 2 is a schematic enlarged cross-sectional view of a main part for describing a stress generated when a magnetic layer is deposited on a non-magnetic support for the magnetic recording medium.

FIG. 3 is a graph showing a change in a cupping value according to a cooling temperature of a magnetic recording medium manufactured according to an example of the present invention and a conventional example.

FIG. 4 is a schematic enlarged sectional view (A) of a main part for explaining stress generated when a magnetic layer is deposited on a nonmagnetic support by a conventional method, and is generated when the magnetic layer is deposited. It is a schematic plan view (B) which shows a stress.

FIG. 5 is a schematic cross-sectional view of a magnetic recording medium (A) having a positive (plus: +) direction cupping and a magnetic recording medium (B) having a negative (minus:-) direction cupping. is there.

6A is a schematic perspective view of a rotary drum, FIG. 6B is a schematic perspective view showing a contact state between a magnetic recording medium and a magnetic head when the magnetic recording medium is flat, and FIG. FIG. 3C is a schematic perspective view showing the contact state between the magnetic recording medium and the magnetic head, and FIG. 3D is a schematic perspective view showing the contact state between the magnetic recording medium and the magnetic head when cupping is performed in the negative direction.

FIG. 7A is a plan view when the magnetic recording medium is not cupped, and FIG. 7B is a plan view when the magnetic recording medium is cupped.

FIG. 8 is a schematic perspective view when loading a magnetic recording medium.

FIG. 9 is a schematic front view when the magnetic recording medium is in sliding contact with the magnetic head.

FIG. 10 is a schematic diagram showing a waveform per RF (high frequency) between a magnetic recording medium and a rotating drum.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Vacuum vapor deposition apparatus (vacuum chamber), 2, 12 ... Non-magnetic support, 3 ... Supply roll, 4 ... Winding roll, 5 ... Rotary guide member, 6 ... Crucible, 7 ... Metal magnetic material (Metal magnetic thin film) ), 8 ... electron beam generator, 11, 11a ... cooling device, 20, 40, 40 '... stress, 43 ... magnetic recording medium,
45: fixed drum, 46: rotating drum, 47: magnetic head, 48: tape regulation guide, X, Z: running direction, Y ...
Rotation direction, EB: electron beam, VD: evaporation area

Claims (10)

[Claims] When a magnetic layer made of a metal magnetic thin film is formed under the action of heat on the non-magnetic support in a film formation region on the guide member while guiding the non-magnetic support on the guide member, A method for manufacturing a magnetic recording medium, wherein the non-magnetic support is cooled in advance before the guide member. 2. The method according to claim 1, wherein a magnetic layer comprising a metal magnetic thin film is formed on the non-magnetic support by a vacuum deposition method. 3. A deposition source on which a material for a magnetic layer is disposed, a supply roll for feeding out a non-magnetic support, a winding roll for winding the non-magnetic support after deposition, the supply roll and the winding-up In a vacuum chamber in which a rotary guide member for performing vapor deposition while guiding the nonmagnetic support between rolls is provided, the rotary guide member is cooled without cooling the nonmagnetic support with the rotary guide member. The method according to claim 2, wherein cooling is performed before the guide member. 4. The method according to claim 3, wherein the non-magnetic support is cooled by a supply roll. 5. The cooling temperature of the non-magnetic support in the supply roll section is in the range of −40 ° C. to + 20 ° C.
Production method described in 1. 6. A guide member for guiding a non-magnetic support, a film formation region on the guide member for forming a magnetic layer made of a metal magnetic thin film on the non-magnetic support under the action of heat, and the guide member And a cooling means for pre-cooling the non-magnetic support at the front of the apparatus. 7. The manufacturing apparatus according to claim 6, wherein the apparatus is configured as a vacuum evaporation apparatus for forming a magnetic layer made of a metal magnetic thin film on a nonmagnetic support. 8. A deposition roll on which a material for a magnetic layer is disposed, a supply roll for feeding out a non-magnetic support, a winding roll for winding up the non-magnetic support after deposition, the supply roll and the winding-up 8. The non-magnetic support member according to claim 7, further comprising a rotary guide member for performing vapor deposition while guiding the non-magnetic support between rolls, and a non-magnetic support cooling unit disposed in front of the rotary guide member. Manufacturing equipment. 9. The production apparatus according to claim 8, further comprising a non-magnetic support cooling means in the supply roll section. 10. The manufacturing apparatus according to claim 9, wherein the cooling temperature of the non-magnetic support in the supply roll section is in a range of −40 ° C. to + 20 ° C.