JP2001291228A - Magnetic recording medium, cleaning tape and magnetic disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent stuck materials from being generated at a magnetic head, to restrain spacing loss and to prevent an error rate from increasing even when the sliding time of the magnetic head is prolonged or the scanning speed is accelerated in order to record information for a long time. SOLUTION: This magnetic recording medium has at least a magnetic layer formed on a nonmagnetic support and holds a sticking prevention agent containing oxime derivative.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording medium and a magnetic disk drive capable of preventing a substance attached to a magnetic head.
Also, the present invention relates to a cleaning tape for removing extraneous matter adhering to a magnetic head.

[0002]

2. Description of the Related Art In the field of magnetic recording, in particular, in a data cartridge for backing up a hard disk, a digital video recorder, and the like, there is a demand for long-time recording along with higher-capacity recording. Conventionally, this long-time recording has been dealt with by increasing the length of the tape by reducing the thickness of the tape, or by increasing the length of the tape by changing the cassette shell or the like.

In the above-mentioned data cartridge, recording and reproduction by a helical scan system is generally applied. However, in the helical scan method, since the magnetic layer surface and the magnetic head slide at high speed, the temperature of the magnetic head surface becomes high during running of the magnetic tape, so that seizure tends to be easily generated on the surface of the magnetic head. If the sliding time is increased or the scanning speed is increased in association with long-time recording, a burn-in product is more easily generated on the surface of the magnetic head.

Particularly, in an environment such as high temperature and low humidity, the polishing power of the magnetic tape is reduced. Therefore, when a metal oxide or the like generated tribologically causes seizure, the seized material is not polished and the magnetic head is not polished. Accumulate on the surface. Then, a gap (spacing) occurs between the magnetic tape and the magnetic head due to the accumulated seizures and the like, causing a problem that a predetermined signal output cannot be obtained.

At present, in order to improve the electromagnetic conversion characteristics and reduce the spacing loss, the surface properties of the tape are improved by super calendar treatment or the like, and the friction between the magnetic tape and the magnetic head is further increased. Tend to be. However, this tendency promotes the generation of burn-in on the surface of the magnetic head described above.

Attempts have been made to add a reducing agent, such as an ascorbic acid derivative, to a magnetic tape as an antioxidant in order to prevent seizure on the magnetic head, or to hold the magnetic tape in order to reduce friction. Attempts have been made to increase the amount of lubricant.

Further, JP-A-59-56226, JP-A-58-194140, and JP-A-59-5622.
No. 6, JP-A-59-3725, JP-A-59-3725
3724, JP-A-58-194135, JP-A-58-224176, JP-A-58-1941
No. 36, JP-A-58-189832, JP-A-58-194133, JP-A-2-177018, etc., as described above, a magnetic layer comprising a metal magnetic thin film is provided on the magnetic layer. Attempts have been made to apply such a compound as a rust inhibitor to prevent the head from burning. However, when the above-mentioned compound is directly applied on the magnetic layer, the cobalt oxide in the magnetic layer is bonded to the above-mentioned compound, and the effect of preventing image sticking cannot be sufficiently exhibited.

[0008] Moreover, even if an antioxidant or a lubricant is held on the magnetic tape, it is not possible to remove the seizure once formed.

[0009] The above-mentioned burn-in generation also causes a similar problem for a so-called magnetic disk device equipped with a magnetic hard disk medium.

[0010] The magnetic hard disk medium has a structure in which a hardened layer made of Ni-P, an underlayer mainly made of Cr, a magnetic layer made of a Co alloy, and a carbon protective film are sequentially laminated on a substrate made of, for example, Al.

In a magnetic disk drive having a magnetic disk medium and a magnetic head, a frictional force is generated between the magnetic head and the magnetic disk, which causes wear of the magnetic head and the magnetic disk medium.

In order to prevent the wear of the magnetic disk medium from progressing to the magnetic layer, a protective film mainly composed of carbon is formed on the magnetic layer, and a lubricating film is further formed on the protective film. By forming it, the wear resistance of the magnetic disk medium is improved. As a lubricant constituting this lubricating film, perfluoropolyether (P
FPE) -based compounds are commonly used.

In a magnetic hard disk drive (HDD), a method is employed in which recording and reproduction are performed with a magnetic head floating above a magnetic disk medium by a fixed amount.

In recent years, the flying height has tended to decrease further in order to improve the recording density of the magnetic disk medium, and the magnetic disk medium and the magnetic head have been used in a semi-contact state. Flying height is about 20nm
If it is less than the above range, it enters a so-called near contact region, and it becomes difficult to secure a stable floating.

Further, research has been conducted toward practical use of contact recording in which recording and reproduction are performed while a magnetic head is intentionally brought into contact with a magnetic disk medium. Also, to increase the data transfer rate,
The rotation speed of the magnetic disk medium tends to increase.

If the time required for the magnetic disk medium and the magnetic head to contact and slide at a high speed becomes longer with the decrease in the flying height and the increase in the rotation speed, seizures are easily generated on the surface of the magnetic head. . When the burn-in material accumulates on the surface of the magnetic head, an extra gap (spacing) is generated between the magnetic disk medium and the magnetic head, causing a problem that the signal output is reduced.

On the other hand, in order to remove burn-in products once formed, a method of using a cleaning tape for physically polishing a magnetic head, and a method of mounting a cleaning roll mechanism for sequentially polishing a magnetic head in a system have been studied. For example, Japanese Patent Application Laid-Open No. 57-208626
Japanese Patent Application Laid-Open Publication No. H11-163873 discloses that α-Al ₂ O ₃ powder having a Mohs' hardness of 8 or more and Cr ₂ O ₃ are coated on a substrate such as a polyester base film.
A cleaning tape has been proposed in which abrasive particles such as powder are bound by a binder resin.

[0018] However, the abrasive particles used in such a physical method have extremely high hardness and are excellent in abrasiveness, but when removing seizures from the magnetic head, the magnetic head itself is worn and damaged. I will. Especially 8
In magnetic heads used for recording and reproducing mm video tapes and digital video tapes, the head gap is 0.3μ.
m and slides at high speed against the tape. For this reason, such a magnetic head is easily damaged even by a small impact, and is worn by the abrasive particles as described above.
Damage is also likely to occur.

On the other hand, Japanese Patent Publication No. 8-001695 proposes to control wear of a magnetic head by controlling the particle size of abrasive particles. However, no matter how much the particle size of the abrasive particles is controlled, wear and damage to the magnetic head cannot be avoided as long as α-Al ₂ O ₃ powder or Cr ₂ O ₃ powder having high hardness is used.

[0020]

Although various measures have been taken against the burn-in substance adhering to the magnetic head from the medium side or the cleaning tape side, all of them are satisfactory. However, further investigation is desired.

Further, in the magnetic disk drive, in order to prevent burn-in to the magnetic head, attempts have been made to increase the flying height of the magnetic head so that the magnetic head does not come into contact with the magnetic disk medium. However, this leads to an increase in spacing, which is contrary to the above-mentioned trend of increasing the recording density. It is also conceivable to increase the amount of lubricant on the surface of the magnetic disk medium to suppress wear of the magnetic head and the magnetic disk medium.However, this causes an increase in spacing and an adsorption phenomenon of the magnetic head to the medium. This is not a very good approach.

Therefore, the present invention has been proposed in view of such a conventional situation.
It is an object of the present invention to provide a magnetic recording medium which does not generate burn-in on a magnetic head even if the sliding time is increased or the scanning speed is increased, suppresses a spacing loss, and prevents an increase in an error rate. It is another object of the present invention to provide a cleaning tape capable of removing burn-in substances attached to the magnetic head without causing wear and damage to the head. In addition, a magnetic disk (H
In a recording / reproducing apparatus having a low flying height using D), a method for preventing burn-in product generation that can reliably suppress the formation of burn-in product is provided, whereby the output decrease due to spacing loss is small and the error rate is increased. An object of the present invention is to provide a magnetic disk drive with a small number.

[0023]

Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above object and found that a specific organic compound has a great effect in suppressing the formation of burn-in products. It was completed.

That is, the magnetic recording medium according to the present invention is characterized in that a magnetic recording medium having at least a magnetic layer formed on a non-magnetic support holds an anti-seizure agent containing an oxime derivative. I do.

Since the oxime derivative as described above has a complexing ability with a metal atom, when it is held on a magnetic recording medium, a complexing reaction occurs with a metal oxide formed on the surface of the magnetic head, The complex is easily desorbed from the surface of the magnetic head. Thus, the metal oxide can be removed from the magnetic head. Therefore, when the present invention is applied, burn-in does not accumulate on the magnetic head, so that a decrease in output due to a spacing loss is prevented and an error rate can be suppressed.

Further, the cleaning tape according to the present invention is characterized in that an anti-seizing agent containing an oxime derivative is held on a support.

Since the oxime derivative as described above has the ability to form a complex with a metal atom, when the cleaning tape holding the oxime derivative is slid against the surface of the magnetic head to which the seizure is attached, The derivative undergoes a complexing reaction with the metal oxide formed on the surface of the magnetic head to form a complex. This complex is easily detached from the magnetic head surface and is removed.

In the magnetic disk drive according to the present invention, a magnetic hard disk is used as a storage medium, and the flying height of the magnetic head with respect to the magnetic hard disk during recording and reproduction is 20 nm or less. Characterized by having a seizure prevention layer containing

Since the oxime derivative as described above has an ability to form a complex with a metal atom, a magnetic disk (HD) holding an anti-seizure agent containing the oxime derivative is used.
When D) and the magnetic head slide at high speed, a complex formation reaction occurs between the metal oxide formed on the head surface and the oxime derivative. As a result, the oxide becomes a complex that easily separates from the head surface, and does not remain on the head surface. Therefore, the spacing loss due to the accumulation of burn-in and the resulting decrease in output are suppressed, and the error rate is also suppressed.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the magnetic recording medium according to the present invention will be described below. The magnetic recording medium according to the present invention is obtained by forming at least a magnetic layer on a nonmagnetic support, and holds an anti-seizing agent containing an oxime derivative (hereinafter, simply referred to as a ligand). It is characterized by having.

The ligand used here includes a compound represented by the following chemical formula (6).

[0032]

Embedded image

Specifically, CH ₃ C (: NOH) CH ₂ C
H ₃ , C ₆ H ₅ CH (OH) C (: NOH) C ₆ H ₅ , CH ₃
CH: NOH, (CH ₃ ) ₂ C: NOH, C ₆ H ₅ CH: N
OH, HON: C ₆ H ₄ : NOH, C ₆ H ₅ C (NH ₂ ):
NOH, CH ₃ C (: NOH) COCH ₃ , CH ₃ (C
H ₂ ) ₂ CH: NOH, C ₁₀ H ₁₆ : NOH, C ₆ H ₅ CH ₂
C (: NOH) C ₆ H ₅ , C ₆ H ₁₀ : NOH, CH ₃ C (:
NOH) C (: NOH) CH ₃ , (HOCH ₂ ): NO
H, (CH ₃ ) ₂ C (OH) C (: NOH) CH ₃ , (C
H ₃ ) ₂ CHCH ₂ (: NOH) CH ₃ , (CH ₃ ) ₂ CHC
H ₂ CH ₂ (: NOH) CH ₃ , C ₆ H ₅ COC (: NO
H) CH ₃ , CH ₃ C (: NOH) CH ₂ C (: NOH)
A ligand having a structure represented by CH ₃ , CH ₃ CH ₂ CH: NOH, or the like can be used.

As described above, there are various kinds of ligands contained in the anti-seizure agent. These may be used alone or in combination of a plurality of kinds. Is also good. When the ligand is internally added to the coating type magnetic layer, the ligand may be present in a form chemically bonded to the binder.

Since the above-mentioned ligand has a complexing ability with a metal atom, when it is added to the inside of the magnetic layer or held on the surface of the magnetic layer, the metal oxide formed on the surface of the magnetic head can be formed. A complex formation reaction occurs between the metal oxide and the metal oxide, and the metal oxide becomes a complex that is easily separated from the surface of the magnetic head. For this reason,
The metal oxide can be removed from the magnetic head. Therefore, burn-in does not accumulate on the magnetic head, so that a decrease in output due to spacing loss is prevented, and an error rate can be suppressed.

The anti-seizure agent preferably contains, together with the ligand, a compound having a cyclic phosphazene structure with a fluorine and benzene ring, as shown in the following Chemical Formula 7.

[0037]

Embedded image

By using the compound represented by the above formula 7 together with the above-mentioned ligand, it is possible to maintain the effect of suppressing the formation of burn-in for a long time. Also,
When the compound represented by the above formula (7) is used instead of perfluoropolyether which is a typical lubricant, the effect of suppressing an increase in friction coefficient can be remarkably exhibited, especially in a high-temperature and high-humidity environment. Further, the compound shown in Chemical formula 7 can be used in combination with a perfluoropolyether. In this case, it is possible to suppress the decrease of the lubricating film due to the flow or evaporation of the lubricating film due to the rotation of the disk, and it is possible to maintain the lubricity of the compound shown in Chemical Formula 7 for a longer period. In particular, when the compound represented by Chemical Formula 7 is used in combination with a typical perfluoropolyether-based lubricant, trade name Z-DOL (manufactured by Ausimont), Al2O3, which is a typical magnetic head material, is used as a Lewis acid. The effect of accelerating the decomposition of the perfluoropolyether-based lubricant as a catalyst can be suppressed.

The compound represented by Chemical formula 7 is contained in an additive represented by trade name X-1P (manufactured by DOW CHEMICAL). That is, by using X-1P as an additive together with the above-described ligand, it is possible to maintain the effect of suppressing seizure generation for a long time.

The configuration of the magnetic recording medium to which the present invention is applied is not particularly limited, and may be a type having a so-called coating type magnetic layer or a type having a deposition type magnetic layer. The former, that is, when the magnetic layer is formed by applying a magnetic paint mainly composed of a magnetic powder and a binder, the anti-seizing agent may be applied to the surface of the magnetic layer,
It may be internally added to the magnetic layer.

When the above-mentioned anti-seizure agent is applied to the surface of the magnetic layer of a magnetic recording medium having a coating type magnetic layer, the amount applied is 10 mg / m ² of the magnetic layer.
The range is preferably 10 g or less. Also,
When the anti-seizure agent is internally added to the magnetic layer, the amount added is preferably from 0.3 to 20 parts by weight based on 100 parts by weight of the magnetic powder. If the application amount or the addition amount of the anti-seizure agent is smaller than the above range, the effect of suppressing the seizure of the magnetic head becomes insufficient. On the other hand, when the amount is larger than the above range, the running property of the magnetic recording medium is deteriorated and the dispersibility of the magnetic powder is reduced, so that good electromagnetic conversion characteristics cannot be obtained.

On the other hand, when the magnetic recording medium has a so-called evaporation type magnetic layer, that is, when the magnetic layer is a metal magnetic thin film, a carbon film is formed on the magnetic layer, and Preferably, an anti-seizure agent is applied. In this case, the application amount of the anti-seizure agent
The amount may be the same as the amount applied to the coating type magnetic layer described above.

By the way, the material constituting the non-magnetic support, the magnetic layer and the like in the magnetic recording medium to which the present invention is applied is as follows:
Any conventionally known one can be used, and there is no particular limitation.

For example, as the nonmagnetic support,
It is preferable to use a film made of a polymer material such as polyethylene terephthalate, polyethylene naphthalate, polyphenylene sulfide, polyimide, and polyamide. Incidentally, the thickness of such a non-magnetic support,
1.0 μm to 100 μm, preferably 2.0 μm to 70
It is suitable as μm. Note that a rigid substrate such as an Al alloy plate or a glass plate may be used. In this case,
An oxide film such as alumite treatment or a Ni-P film may be formed on the surface of the substrate to make the surface hard.

When the magnetic recording medium has a coating type magnetic layer, the magnetic layer is formed by applying a magnetic paint mainly composed of a magnetic powder and a binder. , Γ-Fe ₂ O ₃ , Fe ₃ O ₄ , γ-
Belt compound of Fe ₂ O ₃ and Fe ₃ O ₄ , Co
Containing γ-Fe ₂ O ₃ , Co-containing Fe ₃ O ₄ , Co-containing belt-ride compound of γ-Fe ₂ O ₃ and Fe ₃ O ₄ , CrO ₂ containing one or more metal elements such as Te , Sb, Fe, Bi, etc. containing oxides, F
metals such as e, Co, Ni, Fe-Co, Fe-Ni,
Fe-Co-Ni, Fe-Co-B, Fe-Co-Cr
Alloys such as —B, Mn—Bi, Mn—Al, and Fe—Co—V; needle-like fine particles such as iron nitride; and hexagonal ferrites such as barium ferrite. The magnetic powder is acicular pure iron or Fe-Co, Fe-Ni, F
It may be a ferromagnetic metal powder such as an alloy containing iron as a main component such as e-Ni-Co. Such ferromagnetic metal powder,
Oxides of metal elements, hydrated oxides, inorganic salts,
A method of reducing an organic acid salt or the like in a gas phase with a reducing gas,
It can be obtained by a wet reduction method. After the reduction, a method of impregnating and drying with an organic solvent, a method of immersing in an organic solvent and blowing and drying an oxidizing gas, and a method of blowing an oxidizing gas having a partial pressure adjusted without using an organic solvent are used to thin the surface. An oxide film is formed to provide oxidation stability. The oxide film formed on the surface includes not only the constituent elements of the above-mentioned metals or alloys but also Al, Si, Ca, M
g, Sr, Ba, B, S, Ti, Zn, Na, Zr,
K, Y, La, Ce, Pr, Nd, Sm, Gd, Ge,
Sn, Ga, etc. may be contained.

As the binder, vinyl chloride, vinyl acetate, vinyl propionate, vinyl alcohol, maleic acid, acrylic acid, acrylate, methacrylic acid,
Examples thereof include polymers or copolymers containing methacrylic acid ester, vinylidene chloride, acrylonitrile, methacrylonitrile, styrene, methylstyrene, butadiene, ethylene, vinyl acetal, vinyl butyral, vinyl ether, vinyl pyrrolidone, and the like as constituent units. Further, examples include cellulose resins such as nitrocellulose and cellulose acetate, polyurethane resins, polyester resins, polyamide resins, and silicone resins.

The magnetic powder and the binder as described above are dispersed in a solvent to form a magnetic coating material.
Ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone and cyclohexanone; alcohol solvents such as methanol, ethanol, propanol, butanol and isopropanol; ester solvents such as methyl acetate, ethyl acetate and butyl acetate;
Examples thereof include aromatic hydrocarbon solvents such as benzene, toluene, and xylene, and water.

Incidentally, a lubricant, an abrasive, a hardener, a dispersant, an antistatic agent, a rust inhibitor and the like may be added to the magnetic paint as needed. As the dispersant, the lubricant, the antistatic agent and the rust preventive, any of conventionally known materials can be used, and the material is not limited at all. Monocarboxylic acids having an alkyl chain of 40, electrolytes of these carboxylic acids, monoesters of these carboxylic acids and alcohols having 10 to 40 carbon atoms, polyesters of these carboxylic acids and polyhydric alcohols, or the above-mentioned alkyl chains It is preferable to use an amide, amine, alcohol or the like having Further, silicon oil, paraffin oil, fluorinated compounds of the above compounds, and the like may be used. Examples of the abrasive include aluminum oxide, silicon carbide, chromium oxide, iron oxide, corundum, diamond, silicon nitride, titanium carbide, titanium oxide, and the like. In addition, as an antistatic agent, carbon black is preferably used, and by adding this, it is also possible to improve the strength of the coating film. Further, as the dispersant, various surfactants or various coupling agents can be used. As a curing agent, toluene diisocyanate,
Examples include bifunctional isocyanate compounds such as diphenylmethane diisocyanate, hexamethylene diisocyanate, xylene diisocyanate, naphthalene diisocyanate, and isophorone diisocyanate, or a polymer of these diisocyanates and a reaction product thereof with a polyhydric alcohol.

The magnetic layer formed by the magnetic paint made of the above-described material has a thickness of 0.3 when dried.
The thickness is 1 to 50 μm, preferably 1.0 to 30 μm.
The mixing ratio between the binder and the magnetic powder is 1 to 10 parts by weight, preferably 3 to 9 parts by weight, with respect to 1 part by weight of the binder.
Parts by weight.

When the magnetic recording medium has a vapor deposition type magnetic layer, that is, a magnetic layer made of a metal magnetic thin film, the metal magnetic thin film is formed by coating a ferromagnetic metal material with a non-magnetic material by plating, sputtering, vacuum deposition or the like. What is necessary is just to form by continuously attaching on a magnetic support. Examples of the metal magnetic thin film include metals such as Fe, Co, and Ni, and Co-Ni.
Alloy, Co-Pt alloy, Co-Pt-Ni alloy,
Fe-Co alloy, Fe-Ni alloy, Fe-Co-N
i-type alloy, Fe-Ni-B-based alloy In-plane magnetization recording type composed of Fe-Co-B-based alloy, Fe-Co-Ni-B-based alloy, and perpendicular magnetization composed of Co-Cr-based alloy A recording type is exemplified.

In the case of a metal magnetic thin film of the in-plane magnetization recording type, Bi, Sb, Pb,
A base layer of a low-melting non-magnetic material such as Sn, Ga, In, Ge, Si, and Ti is formed in advance, and a metal magnetic thin film is formed by vertically depositing or sputtering a metal magnetic material on the base layer. It is good to form. When a metal magnetic material is deposited on the underlayer, the low-melting nonmagnetic material of the underlayer diffuses into the metal magnetic thin film, the orientation of the metal magnetic thin film is eliminated, and in-plane isotropy is secured. And the coercivity is improved.

In order to form a magnetic layer composed of a metal magnetic thin film, for example, a vacuum evaporation apparatus 1 as shown in FIG. 1 can be used.

Specifically, first, a non-magnetic support 2 made of a polyethylene terephthalate film is placed in a continuous winding type vacuum evaporation apparatus 1 as shown in FIG. A ferromagnetic metal thin film is formed on the surface. FIG. 1 is a schematic configuration diagram of a continuous winding type vacuum evaporation apparatus 1.

This vacuum evaporation apparatus 1 is used for oblique evaporation, and is cooled to, for example, about -20 ° C. in a vacuum chamber 3 in which the inside is in a vacuum state of, for example, about 10 ⁻³ Pa. The cooling can 4 includes a cooling can 4 that rotates in a direction indicated by a middle arrow A, and a metal thin film deposition source 5 disposed at a position facing the cooling can 4. The vapor deposition source 5 is a container in which a ferromagnetic metal material is contained in a container such as a crucible.

Further, as shown in FIG. 1, the vacuum evaporation apparatus 1 has a non-magnetic support roll 7 mounted on a rotatable supply shaft 6 and a winding rotatable by a driving source (not shown). The magnetic tape roll 9 is mounted on the take-up shaft 8, and the non-magnetic support 2 is caused to run continuously through the cooling can 4.

When a ferromagnetic metal thin film is formed using the vacuum evaporation apparatus 1 having such a configuration, first, the evaporation source 5
The ferromagnetic metal material inside is irradiated with an electron beam 11 accelerated and emitted from an electron beam source 10 to heat and evaporate the ferromagnetic metal material.

Then, the heated and evaporated ferromagnetic metal material is fed out from the non-magnetic support roll 7 mounted on the supply shaft 6 in the direction of arrow B in FIG. 1 and travels along the peripheral surface of the cooling can 4. The ferromagnetic metal thin film is formed by being vapor-deposited on the non-magnetic support 2. Finally, the nonmagnetic support 2 on which the ferromagnetic metal thin film is formed is wound around a magnetic tape roll 9 mounted on a winding shaft 8.

At this time, a deposition-preventing plate 12 is provided between the vapor deposition source 5 and the cooling can 4, and the deposition-preventing plate 12 is provided with a shutter 13.
Is provided so as to be position-adjustable, so that only vapor-deposited particles incident on the nonmagnetic support 2 at a predetermined angle are passed. A ferromagnetic metal thin film is formed by such an oblique deposition method.

Further, when forming the ferromagnetic metal thin film in this manner, it is preferable that oxygen gas is introduced into the vicinity of the surface of the nonmagnetic support 2 through an oxygen gas introduction port (not shown). By introducing oxygen gas, the magnetic properties, durability and weather resistance of the metal magnetic thin film can be improved.

Note that guide rollers 14 and 15 are disposed between the non-magnetic support roll 7 and the cooling can 4 and between the cooling can 4 and the magnetic tape roll 9, respectively.
A predetermined tension is applied to the running non-magnetic support 2 so that the non-magnetic support 2 runs smoothly.

In order to heat the vapor deposition source 5, in addition to the above-described heating means using an electron beam, for example, known means such as a resistance heating means, a high-frequency heating means, and a laser heating means are used. Is also good.

The above description has been made of an example in which a ferromagnetic metal thin film is formed by an oblique deposition method. However, as a method of forming a ferromagnetic metal thin film, a known method such as a vertical evaporation method or a sputtering method may be used. A thin film forming method can be applied.

Here, an oxide film exists near the surface of the ferromagnetic metal thin film due to the oxygen gas introduced during the formation of the ferromagnetic metal thin film. Since this oxide film is non-magnetic,
It causes spacing loss. Therefore, next, the oxide film existing on the surface of the ferromagnetic metal thin film is removed by etching.

When etching is performed after the ferromagnetic metal thin film is formed, the surface oxide layer existing on the surface of the ferromagnetic metal thin film is etched and removed, and the ferromagnetic metal thin film is removed until a desired thickness is obtained. It is thinned. Therefore,
By removing the nonmagnetic oxide film, spacing loss can be suppressed.

The etching method is not particularly limited, and for example, any of a reverse sputtering method, an ion etching method, an ECR plasma etching method and the like is effective. In any case of using any of these methods, the etching condition is that the pressure is 3 × 1 in an Ar gas atmosphere.
It is preferable to set to about 0 ^-3 Torr.

A carbon film is formed on such a metal magnetic thin film. In addition, this carbon film may be any of graphite, diamond, and amorphous. As a method for forming the carbon film, a sputtering method is generally used, but any method such as a CVD method may be applied. As the thickness of the carbon film,
It is preferably 2 nm to 100 nm, particularly 5 nm.
It is preferably from 30 nm to 30 nm.

In order to form a carbon film by a sputtering method, for example, a magnetron sputtering apparatus 21 as shown in FIG. 2 can be used.

In the magnetron sputtering apparatus 21, the inside of the chamber 22 is, for example, about 10 ⁻⁴ Pa
After the pressure has been reduced to a certain degree, the angle of the valve 24 for exhausting to the vacuum pump 23 side is reduced, thereby reducing the exhaust speed and introducing Ar gas from the gas introduction pipe 25 so that the degree of vacuum is about 0.8 Pa, for example. It is said. Further, the magnetron sputtering apparatus 21 includes, for example,-
A cooling can 26 cooled to 40 ° C. and rotating in the direction of arrow C in FIG. 2 and a target 27 disposed opposite to the cooling can 26 are provided. Target 27
Is a material of a carbon film, and carbon is used. Further, the target 27 is supported by a backing plate 28 constituting a cathode electrode. On the back side of the backing plate 28, a magnet 29 for forming a magnetic field is provided.

The magnetron sputtering apparatus 21
The magnetic tape roll on which the ferromagnetic metal thin film is formed is mounted on a rotatable supply shaft 30, and the magnetic tape roll is mounted on a take-up shaft 31 which is rotationally driven by a drive source (not shown). Then, the nonmagnetic support 2 on which the ferromagnetic metal thin film is formed is continuously driven in the direction D in FIG.

When a carbon film is formed by the magnetron sputtering apparatus 21, an Ar gas is first introduced from the gas introduction pipe 25, and the cooling can 26 is used as an anode, and the backing plate 28 is used as a cathode.
A voltage of 0 V is applied so that a current of about 1.4 A flows.

Then, by applying the voltage, Ar gas is turned into plasma and the ionized ions collide with the target 27, whereby the atoms of the target 27 are repelled. At this time, a magnet 29 is provided on the back side of the backing plate 28, and a magnetic field is formed near the target 27, so that the ionized ions are concentrated near the target 26. The atoms ejected from the target 27 are fed out from the magnetic tape roll in the direction of arrow D in FIG. 2 and adhere to the ferromagnetic metal thin film of the nonmagnetic support 2 running along the outer peripheral surface of the cooling can 26. Thus, a carbon film is formed. Finally, the nonmagnetic support 2 on which the carbon film is formed is wound by a magnetic tape roll mounted on a winding shaft 31.

In the magnetic recording medium, a back coat layer may be provided on the surface of the non-magnetic support opposite to the surface on which the magnetic layer is formed. This back coat layer is a layer in which a carbon-based fine powder for imparting conductivity to the binder exemplified above with the magnetic paint and an inorganic pigment for controlling surface roughness are dispersed. It is provided to improve the performance.

The powder to be internally added to the back coat layer is, in addition to carbon black, benzoguanamine resin powder, melamine resin powder, epoxy resin powder, polyethylene terephthalate powder, phthalocyanine pigment powder, titanium oxide Powder, silicon oxide powder, molybdenum disulfide powder, tungsten disulfide powder, hydrous iron oxide powder, magnesium silicate powder, calcium carbonate powder, aluminum silicate powder, barium sulfate powder, clay powder and the like can be used.

The primary average particle size of these powders is 0.001
It is preferably from μm to 1.0 μm. If it ’s too small,
Poor dispersibility in the paint, there is a possibility that the surface of the back coat layer is too rough, if too large, hard large irregularities are formed on the surface of the back coat layer, and when the magnetic tape is wound, the magnetic layer This unevenness is transferred. Further, such a powder is used in an amount of 25 parts per 100 parts by weight of the resin binder.
It is preferable to add to 150 parts by weight. If the content of the powder is too small, the effect of roughening the surface of the back coat layer becomes insufficient, and if the content is too large, the mechanical properties of the coating film of the back coat layer become weak.

By applying the present invention, burn-in of the magnetic head is prevented.
Any structure may be used as long as it slides on the magnetic recording medium at the time of recording / reproduction or at the time of starting / stopping the recording / reproduction operation. Specifically, general ferrite head, metal-in-gap (MIG)
Type head, laminated type head, inductive head, magnetoresistive (MR) type head, and the like. In addition, as the material of these magnetic heads, any conventionally known materials can be used.

Next, an embodiment of the cleaning tape according to the present invention will be described.

The cleaning tape according to the present invention is constituted by holding an oxime derivative (ligand) on a support. The cleaning tape is for removing burn-in substances adhered to the magnetic head by running the cleaning tape against the medium sliding surface of the magnetic head.

As the ligand used here, any of the ligands exemplified above as the anti-seizure agent for the magnetic recording medium can be used. That is, the oxime derivative shown in Chemical formula 6 can be mentioned. Various substituents exemplified above are introduced into this ligand. As described above, there are various kinds of ligands contained in the anti-seizure agent, but these may be used alone or in combination of plural kinds.

Since the above-described ligand has a complexing ability with metal atoms, when the cleaning tape holding the ligand is slid against the surface of the magnetic head, the ligand is formed on the surface of the magnetic head. A complex formation reaction occurs with the converted metal oxide to form a complex. This complex is easily detached and removed from the surface of the magnetic head.

As the support for holding the ligand, polyethylene terephthalate, polyethylene naphthalate,
A polymer film made of polyphenylene sulfide, polyamide, polyimide or the like is used. The thickness of the polymer film is preferably from 1.0 to 200 μm, more preferably from 2.0 to 100 μm.

In addition, a so-called nonwoven fabric in which fibers made of these polymers and the like are joined may be used as the support.

The shape of the support is appropriately selected according to the application. For example, a tape-shaped support is used for a cleaning tape for cleaning a magnetic head for a magnetic tape, and the magnetic head for a floppy (registered trademark) disk is cleaned. For the cleaning tape to be used, a disk-shaped support is used.

In order to hold the ligand on the support, the ligand is dissolved in a solvent to prepare a cleaning paint, and the cleaning paint is applied on the support.

When the support is a polymer film, the cleaning coating is held as a thin film on the surface of the polymer film. When the support is a nonwoven fabric, the nonwoven fabric is held in a form impregnated with a cleaning paint.

Examples of the solvent include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone and cyclohexanone, alcohol solvents such as methanol, ethanol, propanol, butanol and isopropanol, methyl acetate, ethyl acetate and butyl acetate. And an aromatic solvent such as benzene, toluene and xylene, and water.

Further, a layer composed of a powder component such as carbon black and a binder may be formed on the surface of the support, and a cleaning paint may be applied to the surface of this layer.

The carbon black contained in this layer acts to increase the strength of the coating as well as to prevent static charge.

When applying a cleaning paint, the amount of the ligand to be applied is preferably 10 mg to 10 g per 1 m ² . If the amount of the ligand is smaller than this range, the effect of removing the burn-in adhered on the magnetic head is insufficient. If the amount of the ligand is larger than this range, the ligand adheres to the surface of the magnetic head, and the running of the tape is hindered.

The cleaning paint may be held on the support in advance, but may be applied to the support immediately before cleaning.

Further, a binder may be mixed with the cleaning paint, and the ligand may be bound to the support by the binder. In this case, the ligand is retained in a form of a binder layer having a certain thickness. It is also preferable that this layer contains a powder component such as carbon black for the purpose of preventing static charge and improving the strength of the coating film.

As the binder, vinyl chloride, vinyl acetate, vinyl propionate, vinyl alcohol, maleic acid, acrylic acid, acrylate, methacrylic acid,
Examples thereof include polymers or copolymers containing methacrylic acid ester, vinylidene chloride, acrylonitrile, methacrylonitrile, styrene, methylstyrene, butadiene, ethylene, vinyl acetal, vinyl butyral, vinyl ether, vinyl pyrrolidone, and the like as constituent units. Further, cellulose resins such as nitrocellulose and cellulose acetate, polyurethane resins, phenol resins, epoxy resins, phenoxy resins, urea resins, melamine resins, alkyd resins, polyester resins, polyamide resins, silicone resins and the like can be mentioned.

The amount of these binders is preferably not more than 10 parts by weight, more preferably not more than 5 parts by weight, based on 1 part by weight of the ligand. The thickness of the layer is 50 in dry thickness.
μm or less, more preferably 30 μm or less.

Next, a specific embodiment of the magnetic disk drive according to the present invention will be described.

A magnetic recording / reproducing apparatus to which the present invention is applied is a magnetic recording / reproducing apparatus using a magnetic hard disk medium (HD) as a storage medium, and a magnetic head having a flying height of 20 nm or less with respect to the magnetic hard disk medium. The recording / reproduction of the information signal is performed in the area.

As described above, in a system in which the magnetic head faces the magnetic hard disk medium with a low flying height, a problem of burn-in occurs.

Therefore, in the magnetic recording / reproducing apparatus according to the present invention, a magnetic hard disk holding the anti-seizure agent containing the oxime derivative (ligand) is used as a magnetic recording medium.

As the ligand used here, any of the ligands exemplified above as anti-seizure agents for magnetic recording media can be used. That is, the oxime derivative shown in Chemical formula 6 can be mentioned. Various substituents exemplified above are introduced into this ligand. As described above, there are various kinds of ligands contained in the anti-seizure agent, but these may be used alone or in combination of plural kinds.

Since the above-mentioned ligand has a complexing ability with a metal atom, when the magnetic hard disk holding the ligand slides at a high speed with the magnetic head, the ligand forms between the metal oxide formed on the head surface. , A complex forming reaction occurs, and the complex is easily desorbed from the magnetic head. Therefore, the metal oxide can be removed from the magnetic head. Therefore, burn-in does not accumulate on the magnetic head, so that a decrease in output due to spacing loss is prevented, and an error rate can be suppressed.

In order to make the above-mentioned ligand adhere and hold on the surface of the magnetic hard disk, a solution in which an additive is dissolved may be applied by a method such as spin coating or dipping.

Further, the magnetic recording / reproducing apparatus according to the present invention, together with the ligand, has a trade name of X-1P (DOW CHEMIC).
(Manufactured by AL Co.) can be retained on a magnetic hard disk. X-1P contains the compound shown in Chemical formula 7 above.

By using the above-mentioned X-1P together with the above-mentioned ligand, it is possible to maintain the effect of suppressing the formation of burn-in for a long time.

As the applied magnetic hard disk,
It is preferable to have at least a magnetic layer on a non-magnetic support, and to form a lubricating film on the magnetic layer or on the magnetic layer via a protective film.

A magnetic hard disk having an underlayer between a nonmagnetic support and a magnetic layer may be used.

The material constituting the non-magnetic support and the magnetic layer, the protective film, the lubricating film, and the like can be any of conventionally known materials, and are not limited at all.

That is, examples of the nonmagnetic support include an Al-Mg alloy containing Al as a main component, glass, glass ceramics, and synthetic resin.

Further, a hardened layer may be formed to increase the surface hardness of the non-magnetic support. Examples of the material used for the hardened layer include Ni-P. Also,
In order to improve magnetic properties such as coercive force, Cr may be used as the underlayer.

As a material forming the magnetic layer, in the case of a so-called coating type magnetic hard disk, γ-Fe ₂ O ₃
Examples include magnetic powder, polymers such as an epoxy resin, a phenol resin, and a polyurethane that serve as a binder, and Al ₂ O ₃ particles that improve abrasion resistance.

In the case of a so-called thin-film type magnetic hard disk, an alloy containing Co as a main component (Co-Pt-
Cr, Co-Pt-Ni, etc.) are used as the magnetic material. As a magnetic hard disk medium aiming at high-density recording, a thin-film magnetic disk medium is exclusively used.

The protective film is preferably made of carbon. Further, a material such as diamond-like carbon (DLC), carbon nitride, and SiO ₂ having relatively high hardness may be used as the protective film.

As the lubricant, a typical example is a perfluoropolyether (PFPE) -based fluoropolymer. Examples of the method for forming the lubricant include a dipping method and a spin coating method.

[0111]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described, but it goes without saying that the present invention is not limited to these embodiments.

Examination of Magnetic Recording Medium First, in Experiments 1 and 2, the effect of holding the oxime derivative on the magnetic recording medium was examined.

<Experiment 1> Here, a so-called coating type magnetic layer was made to hold an anti-seizure agent containing an oxime derivative (ligand) to prepare a magnetic tape, and recording / reproducing using this magnetic tape was performed. Was done.

Specifically, first, the following composition was prepared and 100 parts by weight of acicular metallic iron magnetic particles (specific surface area: 53.9 cm ² / g, coercive force: 1580 Oe, saturation magnetization: 120 emu / g) thermoplastic polyurethane Resin (average molecular weight 20,000) 10 parts by weight Vinyl chloride-vinyl acetate copolymer 10 parts by weight Carbon (average particle diameter 150 nm) 5 parts by weight α-alumina (average particle diameter 200 nm) 5 parts by weight Olive oil 3 parts by weight Mixed solvent (methyl ethyl ketone) / Methyl isobutyl ketone / toluene = 2: 1: 1) 220 parts by weight This composition was mixed in a ball mill for 48 hours, and then 3.5 parts by weight of a curing agent composed of polyisocyanate was added, followed by further mixing for 30 minutes. did.

The magnetic paint thus obtained was applied on a 7 μm-thick polyethylene terephthalate film so that the thickness after drying was 2 μm. afterwards,
Drying and calendering were performed, and the magnetic layer was formed by leaving in an oven at 60 ° C. for 20 hours to promote curing.

Further, this was cut into a width of 8 mm, and an anti-seizure agent containing ligands (oxime derivatives) represented by the following compounds 1 to 20 was applied to the surface of the magnetic layer by dipping. To complete the magnetic tape.

The anti-seizure agent used here was prepared by using, as a ligand, compounds 1 to 20 shown in Table 1 below.
Each was dissolved in toluene.

[0118]

[Table 1]

A magnetic tape coated with the above-described anti-seizure agent was prepared for a length of 60 minutes, assembled into a cassette shell for 8 mm, formed into a cartridge, and evaluated as follows. In addition, in order to be compared,
A magnetic tape not coated with the above-described anti-seizure agent was prepared, and the same evaluation was performed.

The shuttle durability was controlled by controlling the environmental conditions in a thermostat at a temperature of 40 ° C. and a humidity of 20% RH, and a commercially available VCR (manufactured by Sony Corporation, model name: EV-N) was controlled in the thermostat.
(S7000), each sample tape was run for 100 passes on the shuttle, and after running for 100 passes, how many dB the reproduction output dropped from the initial output was measured and evaluated. The larger the level of the reproduction output is, the more the burn-in is generated on the surface of the magnetic head. Table 2 shows the evaluation results.

[0121]

[Table 2]

As is evident from the results in Table 2, the level of the magnetic tape in which the anti-seizure agent was not applied to the surface of the magnetic layer was greatly reduced, and a seizure was generated on the surface of the magnetic head. You can see that. On the other hand, in each of the magnetic tapes to which the anti-seizure agent containing the ligand was applied, it was found that the level reduction was suppressed and the generation of seizure on the magnetic head was suppressed.

From the above results, it was found that the use of a magnetic tape coated with an anti-seizure agent containing a ligand, that is, an oxime derivative, can prevent generation of seizure on a magnetic head.

<Experiment 2> Here, a magnetic tape was prepared by applying the above-described anti-seizure agent containing a ligand to the surface of a carbon film on a so-called evaporation type magnetic layer.

Specifically, first, Co was applied to a 10 μm-thick polyethylene terephthalate film by an oblique evaporation method using a vacuum evaporation apparatus as shown in FIG. 1 to form a ferromagnetic metal thin film having a thickness of 100 nm. After formation, a film thickness of 10 nm was formed on the surface of the ferromagnetic metal thin film by a sputtering method using a magnetron sputtering apparatus as shown in FIG.
Was formed.

Further, this was cut into a width of 8 mm, and an anti-seizure agent was applied to the surface of the carbon film by dipping to complete a magnetic tape.

The anti-seizure agent used here is obtained by dissolving the same ligand as Compound 1 to Compound 20 used in Experiment 1 in toluene.

Then, the magnetic tapes coated with the respective ligands as described above are incorporated into cassette shells, respectively.
After making the cartridge, the same evaluation as in Experiment 1 was performed.
For comparison, a magnetic tape to which the above-described anti-seizure agent was not applied was prepared, and the same evaluation was performed as Comparative Example 2. Table 3 shows the evaluation results.

[0129]

[Table 3]

As is clear from the results in Table 3, the level of the magnetic tape on which the anti-seizure agent was not applied to the surface of the magnetic layer was greatly reduced, and a seizure was generated on the surface of the magnetic head. You can see that. On the other hand, in each of the magnetic tapes to which the anti-seizure agent containing the ligand was applied, it was found that the level reduction was suppressed and the generation of seizure on the magnetic head was suppressed.

From the above results, it was found that the use of a magnetic tape coated with an anti-seizure agent containing a ligand, that is, an oxime derivative, can prevent generation of seizure on a magnetic head.

Examination of Cleaning Tape Next, in Experiments 3 to 6, the effect of holding the oxime derivative on the cleaning tape was examined.

<Experiment 3> First, a cleaning tape was manufactured as follows.

Specifically, first, the following composition was prepared, and 10 parts by weight of a thermoplastic polyurethane resin (average molecular weight of 20,000) 10 parts by weight of a vinyl chloride-vinyl acetate copolymer 10 parts by weight of carbon (average particle size of 150 nm) 5 parts by weight 5 parts by weight of ligand 5 parts by weight of mixed solvent 220 parts by weight of mixed solvent (methyl ethyl ketone / methyl isobutyl ketone / toluene = 2: 1: 1) The composition was mixed for 48 hours by a ball mill, and then a curing agent composed of polyisocyanate was added. 5 parts by weight were added and mixed for another 30 minutes.

The cleaning paint thus obtained was applied on a polyethylene terephthalate film having a thickness of 7 μm so that the thickness after drying became 2 μm.
Thereafter, the cleaning layer was cured by leaving it in an oven at 60 ° C. for 20 hours to promote curing, and was cut into 8 mm width to prepare a cleaning tape.

Here, as the ligand, the compounds 1 to 20 shown in the above study of the magnetic recording medium were used.

Then, each of the cleaning tapes described above was incorporated into a cassette shell to form a cartridge, and the cartridge was evaluated as follows.

For the purpose of comparison, a cleaning tape having no ligand added to the cleaning layer was prepared and evaluated in the same manner.

More specifically, first, recording is performed on a magnetic tape for 20 minutes using the same video deck as that used in Experiment 1, and then the reproducing operation is repeated until a level reduction of 5 dB occurs. The cleaning tape was run for one minute on the VCR in which the level was reduced as described above. Thereafter, the reproduction output was measured again to evaluate the recovery from the level reduction. The reproduction output was indicated by a value where the initial reproduction output was 0 dB. The recovered output is shown in Table 4 together with the type of ligand used.

[0140]

[Table 4]

As shown in Table 4, when a cleaning tape in which a ligand was internally added to the cleaning layer was run on a VCR, the cleaning was performed without applying the ligand to the cleaning layer. Compared to running the tape on a VCR, the level down was greatly restored.

<Experiment 4> A cleaning tape was prepared in the same manner as in Experiment 3 except that a ligand was not added to the cleaning layer, and after the cutting, a solution in which the ligand was dissolved was dip-coated on the surface of the cleaning layer. Produced. The ligand dissolved in the solution was the same as that used in Experiment 1, and the concentration of the solution was 10 mM. The solvent is a mixed solvent of toluene and alcohol.

After the cleaning tape produced as described above was incorporated into a cassette shell to form a cartridge, the cartridge was run on a VCR in which the level was reduced in the same manner as in Experiment 3, and the output recovery was measured. . In addition, for the purpose of comparison, the same evaluation was performed on a cleaning tape to which neither a ligand was applied nor internally added. Table 5 shows the results together with the types of ligands used.

[0144]

[Table 5]

As shown in Table 5, when a cleaning tape having a ligand applied to the surface of the cleaning layer was used, a cleaning tape having neither the ligand applied to the cleaning layer nor internally added was placed on the VCR. The level down greatly recovered compared to when the vehicle was run at

<Experiment 5> A solution was prepared by dissolving a ligand at a concentration of 10 mM in a mixed solvent of toluene and alcohol. On the other hand, a nonwoven fabric (grade 193, manufactured by Dexter) made of polypropylene was cut into a width of 8 mm, and a solution in which the ligand was dissolved was dip-coated to prepare a cleaning tape.

After the cleaning tape produced as described above was assembled into a cassette shell to form a cartridge, the cartridge was run on a video deck whose level had been reduced in the same manner as in Experiment 3, and the output recovery was measured. . Table 6 shows the results together with the types of ligands used.

[0148]

[Table 6]

As shown in Table 6, when the cleaning tape in which the nonwoven fabric was impregnated with the ligand was run on a VCR, the level reduction was greatly recovered.

<Experiment 6> A solution was prepared by dissolving a ligand at a concentration of 10 mM in a mixed solvent of toluene and alcohol. On the other hand, commercially available 8 mm tape (Sony,
A cleaning tape was prepared by dip coating a solution in which the ligand was dissolved on Hi8 MP (trade name).

After the cleaning tape prepared as described above was assembled into a cassette shell to form a cartridge, the cartridge was run on a VCR whose level had been reduced in the same manner as in Experiment 3, and the output recovery was measured. . Table 7 shows the results together with the types of ligands used.

[0152]

[Table 7]

As shown in Table 7, when the cleaning tape in which the ligand was applied on a commercially available video tape was run on the VCR, the level reduction was greatly recovered.

From the results of Experiments 3 to 6, it was found that the ligand, that is, the oxime derivative, was suitable as a cleaning tape cleaning agent. Also,
It was found that this ligand exerts a good cleaning effect both when applied to the surface of the support or the surface of the cleaning layer and when it is internally added to the cleaning layer.

Examination of Magnetic Recording / Reproducing Apparatus Next, the effect of holding the oxime derivative on a magnetic hard disk medium was examined.

<Experiment 7> First, a sample was prepared as follows.

A solution containing the following representative PFPE-based lubricant, trade name Z-DOL (manufactured by Ausimont), and a ligand compound was prepared.

HOCH ₂ —CF ₂ —O— (CF ₂ —CF ₂ —
_{O) m - (CF 2 -O} ) n -CF 2 -CH 2 OH wherein the solvent fluorinated solvent (trade name HFE-720
0, 3M), the concentration of PFPE is 0.1% by weight, and the amount of the ligand compound is 0.1% by weight relative to PFPE.
It was set to 1.

On the glass substrate on which the Ni-P layer was formed,
A magnetic disk medium (glide height of about 20) in which an underlayer, a magnetic layer (Co-based thin film) and a carbon protective film are sequentially formed.
nm) was immersed in the above solution, and a lubricating film was applied by dipping so as to have a thickness of about 2 nm.

Here, as the ligand, the compounds 1 to 20 shown in the above study of the magnetic recording medium were used.

The magnetic hard disk medium manufactured as described above was slid with a magnetic head under the following conditions using a magnetic disk device as shown in FIG. In addition,
The magnetic head slider used here is a negative pressure slider equipped with a magnetoresistive (MR) head equivalent to 2 Gbpsi.

The main part of the apparatus shown in FIG. 3 is housed in a chamber 1, and the inside of the chamber 1 is maintained in a reduced pressure state by exhaustion by a rotary pump 2.

The magnetic disk 5 is clamped on the spindle 3 and rotated at the rotation speed set by the spindle motor driver 4.

The magnetic disk 5 slides in contact with the magnetic head slider 6 under reduced pressure. A piezo element is attached to the upper portion of the magnetic head slider 6 so that an impact when the magnetic disk 5 comes into contact with the magnetic head slider 6 is detected by the piezo element.

The output of the piezo element is amplified by the amplifier 7, passes through the band-pass filter 8, and is observed by the oscilloscope 9.

A signal output from a magnetic head (MR head) is observed by a personal computer 12 via an amplifier 10 and a read / write analyzer 11.

First, as a preliminary study, the conditions under which the flying height of the magnetic head was sufficiently reduced and contact sliding between the magnetic hard disk medium and the magnetic head surely occurred were examined.

First, the above-mentioned magnetic hard disk sample was set in the chamber, the magnetic disk was rotated so that the linear velocity of the magnetic head slider became 8 m / sec, the inside of the chamber was decompressed, and the output of the piezo was observed. Was.

FIG. 4 shows the relationship between the piezo output and the chamber internal pressure.

According to these results, 100 (normal pressure) to 20
Piezo output does not appear up to 15 kPa
, The rise of the output is observed. This is 20
This indicates that contact sliding between the magnetic head slider and the magnetic hard disk occurs under a pressure of kPa or less.

As the internal pressure of the chamber decreases, the flying height of the magnetic head slider tends to decrease, and the area where the above-mentioned contact sliding occurs is 20 nm or less in terms of the flying height. That is, when the glide height of the magnetic hard disk medium is considered, it is considered that the flying height of the magnetic head slider is reduced to 20 nm or less when the piezo output appears.

In consideration of the results of the above preliminary study, the above magnetic hard disk sample was subjected to a linear velocity of 8 m / sec and a pressure of 15 kP.
Under a, the magnetic head was slid for 1 hour. As the evaluation of electromagnetic conversion characteristics, at the beginning and end of this contact sliding,
A signal corresponding to 14 kfci was recorded and reproduced, and the output (TAA) and pulse width (PW50) of the reproduced waveform were measured. Further, the surface of the magnetic head after sliding was observed with an optical microscope to evaluate whether or not burn-in was present on the surface of the magnetic head.

At this time, a sample was completed under the same conditions as those of the above sample disks except that the ligand compound was not added, and the same evaluation was performed as a comparative example. further,
With respect to this sample, the same evaluation was performed by setting the inside of the chamber to normal pressure and bringing the magnetic head and the magnetic hard disk into a non-contact state.

TAA and P for these samples
Table 8 shows the measurement results of W50 and the evaluation results of the presence / absence of burn-in.

[0175]

[Table 8]

As shown in Table 8, when the ligand compound was not added, when the magnetic head contacted and slid, a burn-in product might be generated on the surface of the magnetic head and the reproduction output might be reduced. Understand.

On the other hand, if a ligand compound is added,
It can be seen that even if contact sliding occurs, a decrease in reproduction output and generation of burn-in on the magnetic head surface can be suppressed.

Next, the effect of using X1-P as an additive together with the above-described anti-seizure agent was examined.

<Experiment 8> A sample disk was prepared under the same conditions as in Experiment 7 described above, except that X-1P was further added as an additive to the solution when forming a lubricating film on the magnetic disk medium. did. As the ligand, compound 3,
Compound 5, compound 9 and compound 20 were used. Note that X
The amount of -1P was 0.05 in weight ratio to PFPE.

The above sample was subjected to a linear velocity of 8 m / sec and a pressure of 1
At 5 kPa, the magnetic head was slid in contact with the magnetic head for 10 hours. As the evaluation of the electromagnetic conversion characteristics, the initial stage of this contact sliding,
After 1 hour, 5 hours, and at the end (10 hours), 14
kfci signal is recorded and reproduced, and a reproduction waveform output (TA
A) and pulse width (PW50) were measured. FIG. 5 shows the evaluation results. Further, the surface of the magnetic head after sliding was observed with an optical microscope to evaluate whether or not burn-in was present on the surface of the magnetic head.

Observation of the surface of the magnetic head revealed that no burn-in was produced in any of the samples. As is clear from FIG. 5, the sample to which X-1P was added was compared with the sample to which X-1P was not added,
The reproduction output was maintained even for long-time contact sliding.
From this, it was found that the combined use of the ligand compound and X-1P can suppress a decrease in reproduction output for a long time while suppressing generation of burn-in.

The embodiments to which the present invention is applied and the characteristics evaluation thereof have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made.

For example, the magnetic disk drive used in the above-described test is a means for ensuring the contact sliding phenomenon between the magnetic head and the magnetic hard disk medium in order to more clearly show the effectiveness of the present invention. The inside of the magnetic disk device is maintained at a reduced pressure. However, the present invention can be applied to any magnetic disk device without contacting the magnetic head with the magnetic hard disk medium without using means such as decompression.

The magnetic head is not limited to a magneto-resistive (MR) head, but may be a giant magneto-resistive (GMR) head.

The ligand compound is not limited to those described above. In the case where the PFPE-based lubricant is preliminarily mixed and applied as in this embodiment, the amount thereof is preferably 0.005 or more and 1.0 or less in terms of a weight ratio with respect to the PFPE-based lubricant. When the mixing ratio is smaller than the lower limit, the effect of suppressing the seizure of the magnetic head is not sufficient, and when the mixture ratio is larger than the upper limit, the ligand compound is easily aggregated, and the friction between the magnetic head and the magnetic hard disk medium is reduced. Is not preferred.

Further, the ligand compound is adhered and held on the surface of the magnetic hard disk medium by a one-step application process of the mixed solution of the lubricant and the ligand compound as in the above-described embodiment. Not limited. For example, a two-stage coating process, such as first applying a solution containing only a lubricant and then applying a solution containing only a ligand compound, can be adhered and held on the surface of the magnetic hard disk medium. It is.

Further, in the magnetic hard disk medium to which the present invention is applied, the material, protective film, lubricating film, etc. constituting the non-magnetic support and the magnetic film are not limited to those described above, but may be any of conventionally known ones. It can be used and is not limited at all.

[0188]

As is clear from the above description, when a ligand having an ability to form a complex with a metal, that is, an oxime derivative, is held on a magnetic recording medium, generation of a seizure on a magnetic head can be prevented. Become like

For this reason, when the magnetic recording medium according to the present invention is used, even if the sliding time is increased or the scanning speed is increased in order to achieve long-term recording, the spacing loss can be suppressed, and the error can be reduced. The rate is prevented from rising.

When the oxime derivative is used as a cleaning agent for a cleaning tape, seizures adhered to the magnetic head can be removed without causing wear and damage to the magnetic head.

Therefore, this cleaning tape is
It is suitable as a cleaning tape for a recording / reproducing system in which the head gap is as small as 0.3 μm or less and the magnetic head slides at high speed with respect to the tape.

Further, according to the present invention, in a low-flying magnetic disk device using a magnetic hard disk as a recording medium, when an oxime derivative is held on a magnetic disk, generation and accumulation of burn-in of a magnetic head can be reliably suppressed. can do.

Therefore, it is possible to provide a magnetic disk drive in which the output loss due to the spacing loss is small and the error rate is also small.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a vacuum evaporation apparatus used for manufacturing a magnetic recording medium.

FIG. 2 is a schematic configuration diagram of a magnetron sputtering apparatus used for manufacturing a magnetic recording medium.

FIG. 3 is a schematic diagram showing a schematic configuration of a magnetic disk device used for a test.

FIG. 4 is a characteristic diagram showing a relationship between a pressure in a chamber and a piezo output.

FIG. 5 is a characteristic diagram showing a relationship between a contact sliding time and a reproduction output when X-1P is used in combination.

[Explanation of symbols]

 65 magnetic hard disk, 66 magnetic head slider

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Noriyuki Kishi, Inventor 6-7-35 Kita Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (72) Inventor Takahiro Kamei 6-35, Kita-Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (72) Kenichi Kurihara, Inventor 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (72) Inventor Toshinori Tsuboi 6-35, Kita-Shinagawa, Shinagawa-ku, Tokyo Sony F term in the company (reference) 5D006 AA01 AA02 AA06 BA09 DA00 DA03 FA00

Claims (11)

[Claims] 1. A magnetic recording medium comprising at least a magnetic layer formed on a non-magnetic support, wherein an anti-seizure agent containing an oxime derivative is held. 2. The magnetic recording medium according to claim 1, wherein the oxime derivative is a compound represented by the following chemical formula 1. Embedded image 3. The magnetic layer is formed by applying a magnetic paint mainly composed of a magnetic powder and a binder, and the anti-seizing agent containing the oxime derivative is applied to the surface of the magnetic layer. 2. The method according to claim 1, wherein
The magnetic recording medium according to the above. 4. The magnetic layer is formed by applying a magnetic paint mainly composed of a magnetic powder and a binder, and an anti-seizure agent containing the oxime derivative is internally added to the magnetic layer. 2. The magnetic recording medium according to claim 1, wherein: 5. The magnetic layer comprises a metal magnetic thin film,
2. The magnetic recording medium according to claim 1, wherein a carbon film is formed on the magnetic layer, and an anti-seizure agent containing the oxime derivative is applied to a surface of the carbon film. 6. The magnetic recording medium according to claim 1, wherein the anti-seizure agent contains a compound having a cyclic phosphazene structure represented by the following chemical formula 2. Embedded image 7. A cleaning tape, wherein an anti-seizing agent containing an oxime derivative is held on a support. 8. The cleaning tape according to claim 7, wherein the oxime derivative is a compound represented by the following chemical formula (3). Embedded image 9. A magnetic disk drive in which a magnetic hard disk is used as a storage medium and a flying height of a magnetic head with respect to the magnetic hard disk during recording and reproduction is 20 nm or less, wherein the magnetic hard disk has a burn-in prevention layer containing an oxime derivative on its surface. A magnetic disk drive comprising: 10. The magnetic disk drive according to claim 9, wherein the oxime derivative is a compound represented by the following chemical formula (4). Embedded image 11. The magnetic disk drive according to claim 9, wherein the anti-seizure layer contains a compound having a cyclic phosphazene structure represented by the following formula (5). Embedded image