JPH10124858A - Magnetic recording medium and cleaning tape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the formation of a seized product on a magnetic head by allowing a magnetic recording medium to hold a seizing inhibitor contg. a phenylhydroxylamine compd. SOLUTION: A magnetic recording medium obtd. by forming a magnetic layer on a nonmagnetic substrate is allowed to hold a seizing inhibitor contg. a phenylhydroxylamine compd. (ligand) represented by formula I. Since the ligand has ability to form a complex with a metallic atom, complex formation reaction is caused between the ligand and a metal oxide formed on the surface of a magnetic head and the metal oxide is converted into a complex easy to release from the surface of the head and can be removed from the head. A seized product does not stick to the head, the reduction of output due to spacing loss is prevented and error rate can be made low.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a magnetic recording medium capable of preventing a substance adhering to a magnetic head and a cleaning tape for removing the substance adhering to the 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 seizures 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. However, even if the magnetic tape holds antioxidants and lubricants,
Once produced, the burn-in cannot be removed.

[0007] On the other hand, in order to remove burn-in products once generated, a method of using a cleaning tape for physically polishing a magnetic head or a method of mounting a cleaning roll mechanism for sequentially polishing a magnetic head in a system has been studied. For example, Japanese Patent Application Laid-Open No. 57-208626
Japanese Patent Application Laid-Open Publication No. H11-15064 discloses that α-Al ₂ O ₃ powder having a Mohs hardness of 8 or more or Cr ₂ O ₃
A cleaning tape has been proposed in which abrasive particles such as powder are bound by a binder resin.

[0008] However, the abrasive particles used in such a physical method have an 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.

[0010]

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.

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.

[0012]

The magnetic recording medium according to the present invention achieves the above-mentioned object and comprises a non-magnetic support having at least a magnetic layer formed thereon, and a phenylhydroxylamine compound. (Hereinafter, simply referred to as a “ligand”).

The ligand used herein includes those represented by the following chemical formula (7).

[0014]

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Since the above-mentioned ligand has the ability to form a complex with a metal atom, when it is held on a magnetic recording medium, a complex-forming reaction occurs with the 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.

The configuration of the magnetic recording medium to which the present invention is applied is not particularly limited, and may have a so-called coating type magnetic layer or a vapor 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-seizure agent may be applied to the surface of the magnetic layer, or may be internally added to the magnetic layer.

In this case, the anti-seizure agent preferably contains a titanate-based coupling agent and a carboxylic acid together with the ligand described above.

That is, since the ligand has the ability to form a complex with a metal atom, it also coordinates and adsorbs to the magnetic powder contained in the magnetic layer. When the ligand is coordinated and adsorbed to the magnetic powder, the ligand cannot contribute to the complex formation reaction with the metal oxide attached to the magnetic head, so that the effect of the ligand to prevent accumulation of the metal oxide is impaired. It is.

Here, when a titanate coupling agent or a carboxylic acid is present, these compounds are easily adsorbed on the surface of the magnetic powder and hinder the ligand from coordinating and adsorbing to the magnetic powder. Therefore, the ligand effectively contributes to complex formation with the metal oxide attached to the magnetic head.

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.

When the anti-seizure agent is applied to the surface of the carbon film as described above, the anti-seizure agent may be added to the above-mentioned ligand together with the above-mentioned ligands by the following chemical formulas (8), (9), (10) and (1)
When a phosphorus-containing compound represented by at least one selected from 1 is contained, the effect of preventing seizure accumulation is further improved.

[0022]

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[0023]

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[0024]

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[0025]

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The anti-seizure agent is held on the magnetic layer as described above, or alternatively, instead of holding the anti-seizure agent on the magnetic layer, the non-magnetic support is opposite to the surface on which the magnetic layer is formed. The anti-seizure agent may be held on the back coat layer formed on the surface of the substrate. Also in this case, the anti-seizure agent may be applied to the surface of the back coat layer or may be internally added to the back coat layer. Since the magnetic tape is usually wound and used in a cassette, when the above-described anti-seizure agent is held in the back coat layer, the anti-seizure agent is transferred to the sliding surface side with the magnetic head. You. Therefore, even when the anti-seizure agent is held on the back coat layer side, the same effect as when the anti-seizure agent is held on the magnetic layer side can be obtained.

On the other hand, the cleaning tape according to the present invention achieves the above-mentioned object, and is characterized in that an anti-seizing agent containing a phenylhydroxylamine compound is retained.

As the ligand used here, those represented by the above formula 7 can be mentioned.

Since these ligands have the ability to form a complex with metal atoms as described above, when the cleaning tape holding the ligand is slid against the surface of the magnetic head to which the seizure is adhered, The ligand undergoes a complex formation 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.

[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 non-magnetic support, and is characterized in that an anti-seizure agent containing a phenylhydroxylamine compound (ligand) is retained. It is assumed that.

The ligand used herein includes those represented by the following chemical formula (12).

[0032]

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As the ligand used as the anti-seizure agent, one kind may be used alone, or two or more kinds may be used in combination. Further, the ligand may be present in a form chemically bonded to the binder.

The configuration of the magnetic recording medium to which the present invention is applied is not particularly limited, and may have a so-called coating type magnetic layer or a vapor 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-seizure agent may be applied to the surface of the magnetic layer, or may be internally added to the magnetic layer.

When the anti-seizure agent is applied to the surface of the magnetic layer, the amount of the anti-seizure agent applied is 1 to 1 m ² of the magnetic layer.
It is preferably 0 mg to 10 g. When the anti-seizure agent is internally added to the magnetic layer, the amount thereof is preferably 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 less than the above range, the effect of suppressing the seizure of the magnetic head becomes insufficient, and if it is more than the above range, the runnability of the magnetic recording medium deteriorates, Dispersibility of the magnetic powder is impaired, and good electromagnetic conversion characteristics cannot be obtained.

When a ligand is internally added to the coating type magnetic layer, a titanate coupling agent or a carboxylic acid may be used in combination for the purpose of preventing the ligand from adsorbing to the magnetic powder. . That is, since the ligand has the ability to form a complex with a metal atom, it also coordinates and adsorbs to the magnetic powder contained in the magnetic layer. When the ligand is coordinated and adsorbed on the magnetic powder, the ligand cannot contribute to the complex formation reaction with the metal oxide attached to the magnetic head, so that the effect of removing the metal oxide of the ligand is impaired.

When a titanate-based coupling agent or a carboxylic acid is present, these compounds are easily adsorbed on the surface of the magnetic powder, so that the ligand is prevented from coordinating and adsorbing on the magnetic powder. Therefore, the ligand effectively contributes to complex formation with the metal oxide of the magnetic head.

Examples of titanate-based coupling agents include amino groups, phosphate groups, acyl groups, carbonyl groups,
It is desirable to use one into which at least one of a hydroxyl group and an alkyl group has been introduced. Specifically, Chemical Formula 13, Chemical Formula 1
4, 15, 16 and 17; Such a titanate-based coupling agent acts to suppress the coordination and adsorption of the ligand to the magnetic powder and to enhance the dispersibility of the magnetic powder.

[0039]

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[0040]

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[0041]

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[0042]

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[0043]

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These titanate coupling agents may be used alone or in combination of two or more.

In order to internally add a titanate-based coupling agent to a magnetic layer, a titanate-based coupling agent may be added to the magnetic paint at the stage of preparing the paint. However, the titanate coupling agent needs to be added before the ligand. That is, a titanate coupling agent is mixed with a magnetic powder, a binder and an organic solvent, kneaded and dispersed, and then a ligand is added. Alternatively, the magnetic powder is previously subjected to a pretreatment with a titanate coupling agent, and the magnetic powder thus treated is kneaded and dispersed together with a binder and an organic solvent, and then a ligand is added.

The amount of the titanate coupling agent added to the magnetic layer is preferably 0.5 to 10 parts by weight based on 100 parts by weight of the ferromagnetic powder. When the amount of the titanate-based coupling agent is smaller than this range, the adsorption of the ligand to the magnetic powder cannot be sufficiently suppressed, and the effect of preventing the seizure by the ligand is insufficient. In addition, the dispersibility of the magnetic powder cannot be sufficiently improved. Conversely, when the amount of the titanate-based coupling agent is larger than this range, a large number of functional groups of the titanate-based coupling agent remain unreacted with the binder or the magnetic powder,
These unreacted functional groups interact with each other to reduce the dispersibility of the magnetic powder. A more preferable range of the internal addition amount is 1.0 to 5.0 parts by weight based on 100 parts by weight of the ferromagnetic powder.

The carboxylic acid may have a pKa of 6 or less. Formic acid, acetic acid, propionic acid, acetic acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, undecylic acid, lauric acid Acids, tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, arachinic acid, saturated fatty acids such as pehenic acid, acrylic acid, crotonic acid, isocrotonic acid, undecylenic acid, oleic acid, elaidic acid Unsaturated fatty acids such as cetreic acid, erucic acid, pracidic acid, sorbic acid, linoleic acid, linolenic acid, arachidonic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, speric acid, azelaic acid Saturated aliphatic dicarboxylic acids such as cephasic acid, maleic acid, fumaric acid Aliphatic unsaturated dicarboxylic acids like phthalic acid, isophthalic acid, aromatic dicarboxylic acids such as terephthalic acid, and tricarboxylic acids such as citric acid. In particular, oleic acid and myristic acid are practical because they also exert a lubricating effect.

The amount of the carboxylic acid added to the magnetic layer is preferably 1 to 30 parts by weight based on 100 parts by weight of the magnetic powder.

These titanate-based coupling agents and carboxylic acids are not limited to the case where an anti-seizure agent is internally added to the coating type magnetic layer, but also prevent the seizure on the surface of the coating type magnetic layer or the deposition type magnetic layer. It may be used in combination when applying the agent. However, since the adsorption of the ligand to the magnetic powder becomes the most problematic when the ligand is internally added to the magnetic layer, it is effective to use the ligand together with such internal addition.

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.

When the anti-seizure agent is applied to the surface of the carbon film as described above, the anti-seizure agent is added to the anti-seizure agent together with the ligand described above,
A phosphorus-containing compound represented by at least one selected from the following may be contained.

[0052]

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[0053]

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[0054]

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[0055]

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The phosphorus-containing compound may be held on the coating type magnetic layer, but it is more practical to apply the compound on the surface of the evaporation type magnetic layer.

In addition to holding the anti-seizure agent in the magnetic layer as described above, or instead of holding the anti-seizure agent in the magnetic layer, the non-magnetic support is opposite to the surface on which the magnetic layer is formed. The anti-seizure agent may be held on the back coat layer formed on the surface of the substrate. Also in this case, the anti-seizure agent may be applied to the surface of the back coat layer or may be internally added to the back coat layer. Since the magnetic tape is usually wound and used in a cassette, when the above-described anti-seizure agent is held in the back coat layer, the anti-seizure agent is transferred to the sliding surface side with the magnetic head. You. Therefore, even when the anti-seizure agent is held on the back coat layer side, the same effect as when the anti-seizure agent is held on the magnetic layer side can be obtained. The amount of the anti-seizure agent to be retained may be the same as the amount applied to or internally added to the magnetic layer.

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

For example, as the nonmagnetic support,
Polyethylene terephthalate, polyethylene-2,6-
Polyesters such as naphthalate, polyolefins such as polypropylene, celluloses such as cellulose triacetate and cellulose diacetate, vinyl-based resins, polyimides, polyamides, polycarbonates, and polymer materials represented by polyphenylene sulfide and the like. It is preferable to use a film. The thickness of such a nonmagnetic support is 1.0 to 100 μm.
m, preferably 2.0 to 70 μm. Note that a metal plate such as an Al alloy plate, a glass plate, or a rigid substrate such as ceramics may be used. In this case, an oxide film such as alumite treatment or a Ni-P film is formed on the substrate surface. The surface may be hardened.

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 and the like.

Further, metals such as Fe, Co, and Ni;
e-Co, Fe-Ni, Fe-Co-Ni, Fe-Co
-B, Fe-Co-Cr-B, Mn-Bi, Mn-A
1, Fe-Co-V, Fe-Al, Fe-Ni-Al,
Fe-Al-P, Fe-Ni-Si-Al, Fe-Ni
-Si-Al-Mn, Fe-Mn-Zn, Fe-Ni-
Zn, Co-Ni, Co-P, Fe-Co-Ni-C
r, alloys such as Fe-Co-Ni-P, and ferromagnetic metal powders such as iron carbide and iron nitride.

Such a ferromagnetic metal powder can be prepared by a method of reducing an oxide, a hydrated oxide, an inorganic salt, an organic acid salt or the like of a metal element as described above in a gas phase with a reducing gas or a method of performing a wet reduction. Can be obtained by In producing the ferromagnetic metal powder, an appropriate amount of a light metal element such as Al, Si, P, or B may be added for the purpose of preventing sintering during reduction or maintaining the shape.

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 controlled partial pressure without using an organic solvent are used. A thin oxide film is formed on the surface to provide oxidation stability. The oxide film formed on the surface is not only the constituent element of the metal or alloy described above,
Al, Si, Ca, Mg, Sr, Ba, B, S, Ti,
Zn, Na, Zr, K, Y, La, Ce, Pr, Nd,
It may contain Sm, Gd, Ge, Sn, Ga and the like.

Further, as the magnetic powder, besides the above oxides and ferromagnetic metal powders, hexagonal plate-like ferrite can be used. Examples of the hexagonal plate-like ferrite include M-type, W-type, Y-type, and Z-type barium ferrite, strontium ferrite, calcium ferrite, lead ferrite, and the like. Ti, Co-Ti-Zn, Co-Ti-N
b, Co-Ti-Zn-Nb, Cu-Zr, Ni-Ti
The addition of such as can also be used.

These magnetic powders may be used alone or in combination of two or more.

The size of these magnetic powders is desirably set as follows.

[0067] First, the specific surface area is preferably from 30~80m ² / g, and more preferably 40~70m ² / g. The magnetic powder having a specific surface area in this range has very fine particles, and by using such a fine magnetic powder, high-density recording becomes possible and noise is reduced.

In particular, when the magnetic powder is acicular particles, the major axis length is 0.05 to 0.50 μm and the axial ratio is 2 to 1.
It is preferably 5. When the major axis length is less than 0.05 μm, it becomes difficult to disperse the magnetic powder in the paint, and when the major axis length exceeds 0.50 μm, noise may increase. On the other hand, when the axial ratio is less than 2, the orientation of the magnetic powder is reduced, and the output is reduced. Conversely, when the axial ratio exceeds 15, the short-wavelength signal output decreases.

On the other hand, when the magnetic powder is plate-like ferrite, the plate diameter is 0.01 to 0.5 μm and the plate thickness is 0.001 to
It is preferably 0.2 μm.

The major axis length, axial ratio, plate diameter and plate thickness of the magnetic powder shown above were obtained by randomly selecting 100 or more samples from a transmission electron micrograph and calculating the average value. is there.

As the binder to be contained in the magnetic layer of the present invention, known thermoplastic resins, thermosetting resins, reactive resins and the like conventionally used as binders for magnetic recording media can be used. Those having an average molecular weight of 5,000 to 100,000 are preferred.

Examples of the thermoplastic resin include vinyl chloride, vinyl acetate, vinyl propionate, vinyl alcohol, maleic acid, acrylic acid, acrylic acid ester, methacrylic acid, methacrylic acid ester, vinylidene chloride, acrylonitrile, methacrylonitrile, styrene, methyl Polymers or copolymers containing styrene, butadiene, ethylene, vinyl acetal, vinyl butyral, vinyl ether, vinyl pyrrolidone, and the like as constituent units are included. Specifically, a vinyl chloride-vinyl acetate copolymer,
Vinyl chloride-vinylidene chloride copolymer, vinyl chloride-acrylonitrile copolymer, acrylate-acrylonitrile copolymer, acrylate-vinyl chloride-vinylidene chloride copolymer, vinyl chloride-acrylonitrile copolymer, acrylate -Acrylonitrile copolymer, acrylate-vinylidene chloride copolymer, methacrylate-vinylidene chloride copolymer,
Examples include methacrylate-vinyl chloride copolymer, methacrylate-ethylene copolymer, vinylidene chloride-acrylonitrile copolymer, acrylonitrile-butadiene copolymer, polyvinyl butyral, and styrene-butadiene copolymer. Other examples include polyvinyl fluoride, polyamide resins, and cellulose derivatives such as cellulose acetate butyrate, cellulose diacetate, cellulose triacetate, cellulose propionate, and nitrocellulose, polyurethane resins, polyester resins, amino resins, and synthetic rubbers. Can be

Examples of the thermosetting resin or the reactive resin include a phenol resin, an epoxy resin, a polyurethane curing resin, a urea resin, a melamine resin, an alkyd resin, a silicone resin, a polyamine resin, and a urea formaldehyde resin. .

Further, a polar functional group may be introduced into all of these binders for the purpose of improving the dispersibility of the pigment component.

The polar functional groups include -SO ₃ M, -OS
O ₃ M, —COOM, P ＝ O (OM) ₂ (where M represents a hydrogen atom or an alkali metal such as lithium, potassium, and sodium) and the like. Also, -NR
^{1 R 2, -NR 1 R 2} R 3+ X - side chain amine having end groups of or,> NR ¹ R ²⁺ X ^- main-chain amine represented by (wherein, R ^1, R ^2, R ³ represents a hydrogen atom or a hydrocarbon group, and X ⁻ represents a halogen element ion such as fluorine, chlorine, bromine or iodine, an inorganic ion, or an organic ion. Further, polar functional groups include -OH,-
SH, -CN, epoxy group and the like. The amount of the polar functional group contained in the binder is 10 ^-8 to 10 ^-1 mo.
1 / g, preferably 10 ^-6 to 10 ^-2 mol / g.
Is more preferable.

The binders described above are used in the magnetic layer. These binders may be used alone or in combination of two or more.

The mixing amount of the binder in the magnetic layer is determined by the amount of the magnetic powder 1
1 to 200 parts by weight, preferably 10 to 100 parts by weight
５０50 parts by weight. If the amount of binder is too high,
The proportion occupied by the magnetic powder in the magnetic layer becomes relatively small, and the output decreases. In addition, when the magnetic layer repeatedly slides on the magnetic head and various sliding members on the drive, plastic flow easily occurs in the magnetic layer, and the running durability of the medium is reduced.
If the amount of the binder is too small, the magnetic layer becomes brittle,
The running durability of the medium decreases.

The magnetic powder and the binder as described above are dispersed in a solvent to form a magnetic paint.
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, butyl acetate, propyl acetate, ethyl lactate, and ethylene glycol Ester solvents such as acetate, diethylene glycol dimethyl ether, 2-ethoxyethanol, ether solvents such as tetrahydrofuran and dioxane, benzene, toluene, aromatic hydrocarbon solvents such as xylene, methylene chloride, ethylene chloride, carbon tetrachloride, chloroform, Examples thereof include halogenated hydrocarbon solvents such as chlorobenzene 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 conventionally known materials can be used, and there is no particular limitation.

Examples of the lubricant include a solid lubricant such as graphite, molybdenum disulfide, tungsten disulfide, etc.
Monocarboxylic acids having an alkyl chain of 0 to 40, electrolytes of these carboxylic acids, these carboxylic acids and 10 to 10 carbon atoms
It is preferable to use monoesters with 40 alcohols, polyesters of these carboxylic acids with polyhydric alcohols, or amides, amines and alcohols having the above-mentioned alkyl chains. Further, silicon oil, paraffin oil, fluorinated compounds of the above compounds, terpene compounds, oligomers thereof, and the like may be used.

As an abrasive, aluminum oxide (α,
β, γ), silicon carbide, chromium oxide, iron oxide, corundum, diamond, silicon nitride, titanium carbide, titanium oxide (rutile, anatase), garnet, emery, boron nitride and the like. These abrasives preferably have a Mohs hardness of 4 or more, preferably 5 or more, and a specific gravity of 2 to 6, preferably 3 to 5. The average particle size is 0.5 μm or less, preferably 0.3 μm
m or less is good. The average particle size was obtained by randomly selecting 100 or more samples from a transmission electron microscope photograph and calculating the average value. The addition amount of these abrasives is 20 parts by weight or less based on 100 parts by weight of the ferromagnetic powder.
Preferably, the amount is 10 parts by weight or less.

As the antistatic agent, carbon black is preferably used, and by adding this, it is possible to improve the strength of the coating film.

Further, as the dispersant, various surfactants or various coupling agents can be used.

Examples of the curing agent include alkylene diisocyanates such as toluene diisocyanate, diphenylmethane diisocyanate, and hexamethylene diisocyanate.
Examples thereof include bifunctional isocyanate compounds such as xylene diisocyanate, naphthalene diisocyanate, and isophorone diisocyanate, or a reaction product of a polymer of these diisocyanates and a polyhydric alcohol. The addition amount of these curing agents is 5 to 80 parts per 100 parts by weight of the binder.
It is preferably used in an amount of 10 parts by weight, more preferably 10 to 50 parts by weight.

To prepare a magnetic paint, the above-mentioned materials are formed into a paint by a kneading step, a mixing step, and a dispersion step. As a dispersing device and a kneading device, a roll mill, a ball mill, a sand mill, an agitator, a kneader, an extruder, a homogenizer, an ultrasonic disperser, and the like are used.

The magnetic layer thus formed is formed by applying the magnetic paint prepared as described above onto a non-magnetic support by any method such as spraying or roll coating and drying. After that, it was led to a calendar device,
The magnetic layer may be subjected to a surface smoothing treatment. Here, the magnetic layer has a dry thickness of 0.1 to 50 μm, preferably 1.0 to 30 μm.

When such a coating type magnetic layer is provided, a non-magnetic powder is dispersed in a binder between the magnetic layer and the non-magnetic support in order to smooth the magnetic layer. Alternatively, a non-magnetic layer (lower layer) may be provided. When the magnetic layer is provided directly on the non-magnetic support, particularly when the thickness of the magnetic layer is small, the surface roughness of the non-magnetic support tends to appear on the surface of the magnetic layer, making it difficult to smooth the surface of the magnetic layer. become. When a non-magnetic layer is provided between the non-magnetic support and the magnetic layer, the thickness is increased between the non-magnetic support and the magnetic layer, so that the surface roughness of the non-magnetic support hardly appears on the magnetic layer surface. As a result, the magnetic layer can be formed on a smooth surface.

As the binder used for the non-magnetic layer, any of those exemplified for the magnetic layer can be used.

The non-magnetic powder includes, for example, α-
Non-magnetic iron oxide such as Fe ₂ O ₃ , goethite, rutile type titanium oxide, anatase type titanium oxide, tin oxide, tungsten oxide, silicon oxide, zinc oxide, chromium oxide, cerium oxide, titanium carbide, BN, α-alumina , Β-alumina, γ-alumina, calcium sulfate, barium sulfate,
Examples include molybdenum disulfide, magnesium carbonate, calcium carbonate, barium carbonate, strontium carbonate, barium titanate, and the like. These non-magnetic powders may be doped with an appropriate amount of impurities depending on the purpose.
The surface may be treated with a compound such as i, Ti, Sn, Sb, or Zr. In addition, one kind of these nonmagnetic powders may be used alone, or a plurality of kinds may be used in combination. The non-magnetic powder has a non-surface area of 30 to 80 m ² / g, and more preferably 40 to 70 m ² / g.
Is more preferable.

The non-magnetic layer may contain, in addition to the non-magnetic powder, carbon black such as rubber furnace, pyrolytic carbon, color black, and acetylene black, if necessary. The specific surface area of carbon black is preferably 100 to 400 m ² / g, and the DBP oil absorption is preferably 20 to 200 ml / 100 g.

The specific surface area of carbon black and other non-magnetic powder is set so that the non-magnetic layer is formed on a smooth surface, and thereby the magnetic layer is formed on a smooth surface. is there. In carbon black and other non-magnetic powders, the specific surface area within the above-mentioned range means that the particles are fine particles, whereby the non-magnetic layer, and thus the magnetic layer, is formed with a smooth surface. Then, by making the surface of the magnetic layer rough, modulation noise and spacing loss are suppressed, and high electromagnetic conversion characteristics can be obtained.

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 made of a ferromagnetic metal 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.

Among them, 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.

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,
The thickness is preferably 2 to 100 nm, particularly 5 to 30 n.
m is preferred.

As described above, in the magnetic recording medium to which the present invention is applied, the non-magnetic support on which the magnetic layer is formed is provided for the purpose of, for example, the running property of the medium, antistatic and transfer prevention. A back coat layer may be provided on the surface opposite to the surface. 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 the application of 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 a phenylhydroxylamine compound on a support.

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 compound represented by the above formula (12) can be mentioned. Further, one kind of the ligand may be used alone, or a plurality of kinds may be used in combination.

Since the above-mentioned ligand has a complexing ability with a metal atom, 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 a 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 a cleaning tape for cleaning a magnetic head for a floppy disk is used for a cleaning tape for cleaning a magnetic head for a floppy disk. A disk-shaped support is used.

To hold the ligand on the support, the ligand is dissolved in a solvent to prepare a cleaning coating, and the cleaning coating is applied on the support.

When the support is a polymer film, the cleaning paint 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 benzene, toluene, xylene and other aromatic hydrocarbon solvents and water.

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 is
It acts to increase the strength of the coating film together with antistatic.

When applying a cleaning coating, the amount of the ligand 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.

Examples of the binder include vinyl chloride, vinyl acetate, vinyl propionate, vinyl alcohol, maleic acid, acrylic acid, acrylate, methacrylic acid,
Methacrylic acid esters, vinylidene chloride, acrylonitrile, methacrylonitrile, styrene, methylstyrene, butadiene, ethylene, vinyl acetal. A polymer or copolymer containing vinyl butyral, vinyl ether, vinyl pyrrolidone, or the like as a constituent unit may be used. 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 10 parts by weight or less, and more preferably 5 parts by weight or less 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.

[0115]

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 to 6, the effect of holding a phenylhydroxylamine compound (ligand) on a magnetic recording medium was examined.

<Experiment 1> Here, a phenylhydroxylamine compound (ligand) was added to a so-called coating type magnetic layer.
A magnetic tape was prepared by applying an anti-seizure agent containing, and recording and reproduction were performed using the magnetic tape.

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 described later was applied to the surface of the magnetic layer by a dipping method to complete a magnetic tape.

The anti-seizure agent used here is obtained by dissolving a ligand having the general formula shown in the following Chemical Formula 22 in toluene.

[0122]

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The ligand contained in the anti-seizure agent
Is a substituent R in Chemical formula 22 ^Two, R^Five, R⁶Is hydrogen
And the substituent R¹, R^Three, R^FourAre various as shown in Table 1.
Different compounds 1 to 8 were used. In Table 1, Ar is
Indicates an aryl group.

[0124]

[Table 1]

Then, each of the magnetic tapes coated with the above-described ligand is incorporated into a cassette shell, respectively.
After making the cartridge, the evaluation was performed as follows. For the purpose of comparison, the same evaluation was performed on a magnetic tape to which the above-mentioned anti-seizure agent was not applied.

Specifically, first, the sliding surface with the magnetic tape has a magnetic head as shown in FIG. 1, ie, the pair of magnetic core halves 1 and 2 are made of a ferromagnetic oxide such as single crystal ferrite. A ferromagnetic metal thin film 3 having a high saturation magnetic flux density Bs, such as an FeAlSi alloy (Sendust), is formed on the magnetic core halves 1 and 2 as if the joining surfaces of the magnetic core halves 1 and 2 are notched obliquely. A VCR equipped with a magnetic head having a magnetic gap at the contact surface 3 was prepared.

Then, using such a video deck,
First, recording is performed on each magnetic tape for one minute, and its reproduction output is measured. After that, record for 20 minutes,
After the reproduction operation was repeated 10 times, the reproduction output was measured again, and the output reduction (level reduction) based on the initial reproduction output was obtained.

After the recording / reproducing operation was performed, the sliding surface of the magnetic head mounted on the video deck with the magnetic tape was observed with a microscope. In addition, as a result of observation,
On the sliding surface of the magnetic tape in the magnetic head, a case where burn-in was generated on the ferromagnetic metal thin film 3 was evaluated as x, and a case where burn-in was not recognized was evaluated as ○.

Table 2 shows the results of the level down and the observation with a microscope. Table 2 also shows the results for the magnetic tape to which the anti-seizure agent was not applied.

[0130]

[Table 2]

As shown in Table 2, in the magnetic tape in which the anti-seizure agent was not applied to the surface of the magnetic layer,
Although the level was greatly reduced and burn-in was generated on the surface of the magnetic head, Compound 1 to Compound 8
In each of the magnetic tapes to which the anti-seizure agent containing a ligand as described above was applied, the level reduction was suppressed, and no seizure on the surface of the magnetic head was observed.

FIG. 2 shows a magnetic head after recording and reproducing on a magnetic tape coated with a ligand-containing anti-seizure agent, based on a micrograph. FIG. 3 shows a drawing of a magnetic head based on a photomicrograph of a magnetic head after recording / reproducing on a magnetic tape on which the anti-seizure agent is not applied to the surface of the magnetic layer. In FIG. 3, the ferromagnetic metal thin film 3
In contrast to FIG. 2, since the burn-in product 4 has been generated, the burn-in product 4 is not generated at all in FIG.

From the above results, the use of a magnetic tape coated with an anti-seizure agent containing a ligand, that is, a phenylhydroxylamine compound, makes it possible to prevent the formation of seizure on the magnetic head. all right.

<Experiment 2> Here, a so-called coating type magnetic layer was internally added with an anti-seizure agent containing a carboxylic acid together with the above-mentioned ligand to prepare a magnetic tape.

Specifically, first, the same composition as prepared in Experiment 1 described above was further added with 6 parts by weight of carboxylic acid (oleic acid or myristic acid) and 5 parts by weight of ligand. On the other hand, in the same manner as in Experiment 1, mixing, addition of a curing agent, and mixing were performed.

Then, in the same manner as in Experiment 1, the magnetic paint thus obtained was applied on a polyethylene terephthalate film, dried, calendered, and subjected to a heat treatment for accelerating curing to form a magnetic layer. After the formation, it was cut to complete the magnetic tape. Here, since the anti-seizure agent was internally added to the magnetic layer, the anti-seizure agent was not applied to the surface of the magnetic layer.

The ligands to be internally added to the magnetic layer were the same as those used in Experiment 1 except for compounds 1 to
Compound 8 was used.

Then, a magnetic tape in which each of the above-mentioned ligands and oleic acid are combined and internally added to the magnetic layer, and a combination of each of the above-mentioned ligands and myristic acid are internally added to the magnetic layer. Each of the magnetic tapes was assembled into a cassette shell to form a cartridge, and the cartridge was evaluated as follows. For the purpose of comparison, the same evaluation was performed for a magnetic tape containing only a ligand, a magnetic tape containing only oleic acid, and a magnetic tape containing only myristic acid. .

The evaluation method is the same as that shown in Experiment 1. Table 3 shows the evaluation results of the anti-seizure agent obtained by combining the ligand and the carboxylic acid internally added to the magnetic layer.

[0140]

[Table 3]

As shown in Table 3, in the magnetic tape in which only the carboxylic acid was added to the magnetic layer, the level was greatly reduced, and burn-in was generated on the surface of the magnetic head. On the other hand, in the magnetic tape in which the ligand and the carboxylic acid were combined and internally added to the magnetic layer, the level reduction was suppressed, and no sticking to the surface of the magnetic head was observed.

In Experiment 1, the effect of preventing seizure was obtained by applying an anti-seizure agent to the surface of the magnetic layer without using a carboxylic acid, but the ligand was also coordinated with the magnetic powder. It can be seen that in the case where an anti-seizure agent is internally added to the magnetic layer as in Experiment 2, it is advisable to use a combination of a ligand and a carboxylic acid.

A magnetic head after recording / reproducing on a magnetic tape in which a ligand and a carboxylic acid are combined and internally added to a magnetic layer is illustrated on the basis of a micrograph, as shown in FIG. FIG. 3 shows a drawing of a magnetic head after recording and reproduction on a magnetic tape containing only carboxylic acid, based on a micrograph.

From the above results, the use of a magnetic tape in which a ligand, that is, a phenylhydroxylamine compound and a carboxylic acid are combined and internally added to a magnetic layer, can further prevent generation of seizure on a magnetic head. It turned out to be like this.

<Experiment 3> Here, a magnetic tape was prepared by applying the above-mentioned anti-seizure agent containing a ligand to the surface of a carbon film on a so-called vapor deposition type magnetic layer.

More specifically, first, a 10 μm-thick polyethylene terephthalate film was coated with Co by oblique deposition.
And a 100 nm thick ferromagnetic metal thin film was formed, and then a 10 nm thick carbon film was formed on the surface of the ferromagnetic metal thin film by a sputtering method.

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 ligands such as compounds 1 to 8 shown in Chemical formula 22 in toluene, as in Experiment 1.

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 the purpose of comparison, the same evaluation was performed on a magnetic tape to which no ligand was applied. Table 4 shows the evaluation results.

[0150]

[Table 4]

As shown in Table 4, in the case of the magnetic tape in which the anti-seizure agent was not applied to the surface of the carbon film, the level was greatly reduced, and the seizure was generated on the surface of the magnetic head. On the other hand, in each of the magnetic tapes coated with an anti-seizure agent containing a ligand such as Compounds 1 to 8, the level reduction was suppressed, and no seizure on the magnetic head surface was observed.

The drawing of the magnetic head after recording / reproducing on the magnetic tape coated with the ligand based on a micrograph is the same as FIG. 2, and the ligand is not coated. Drawing the magnetic head after performing recording and reproduction on the magnetic tape based on a micrograph,
It became the same as FIG.

From the above results, the use of a magnetic tape coated with a ligand, that is, an anti-seizure agent containing a phenylhydroxylamine compound on the surface of a carbon film can further prevent the generation of seizure on a magnetic head. It turned out to be like this.

<Experiment 4> Here, an anti-seizure agent containing a compound containing phosphorus together with a ligand was applied to the surface of a carbon film on a so-called evaporation type magnetic layer to produce a magnetic tape.

Specifically, first, a ferromagnetic metal thin film and a carbon film were formed in the same manner as in Experiment 3 described above, and then cut to complete a magnetic tape. Then, an anti-seizure agent formed by dissolving a compound containing phosphorus together with a ligand in toluene was applied to complete a magnetic tape.

As the ligand contained in the anti-seizure agent, ligands such as compounds 1 to 8 shown in Chemical formula 22 were used in the same manner as in Experiment 1. Further, the compound containing phosphorus contained in the anti-seizure agent together with the ligand is represented by the general formula of Chemical Formulas 23 to 26. Specifically, the compound containing phosphorus is represented by Chemical Formula 23
The compounds K-1, K-2, L-1, L-2, M-1, and M- in which the substituents R ^{7 to} R ¹⁸ in Chemical Formula 26 are shown in Table 5
2, N-1 and N-2 were used.

[0157]

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[0158]

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[0159]

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[0160]

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[0161]

[Table 5]

Then, the magnetic tape coated with the anti-seizure agent containing each of the ligands and the compound containing phosphorus as described above was incorporated into a cassette shell to form a cartridge. An evaluation was performed. For the purpose of comparison, the same evaluation was performed on a magnetic tape to which a seizure preventing agent containing no ligand was applied. Table 6 shows the evaluation results.

[0163]

[Table 6]

As shown in Table 6, in the magnetic tape in which only the compound containing phosphorus was applied to the magnetic layer, the level was greatly reduced, and burn-in was generated on the surface of the magnetic head. On the other hand, in the magnetic tape coated with the anti-seizure agent in which the ligand and the compound containing phosphorus were combined, the level reduction was suppressed, and no seizure on the magnetic head surface was observed.

In Experiment 3, a magnetic tape in which only a ligand was coated on a magnetic layer without using a phosphorus-containing compound was evaluated, but a common ligand was used in Experiment 3. It can also be seen that when used, better results are obtained when used in combination with a compound containing phosphorus.

A magnetic head after recording and reproducing data on a magnetic tape in which a ligand and a compound containing phosphorus are combined and internally added to a magnetic layer is shown in FIG. FIG. 3 is a drawing of a magnetic head after recording and reproduction on a magnetic tape containing only a phosphorus-containing compound, based on a micrograph.

From the above results, using a magnetic tape in which a ligand, that is, a phenylhydroxylamine compound and a compound containing phosphorus are combined and internally added to a magnetic layer, the generation of burn-in on a magnetic head is reduced. It turns out that it can be prevented.

<Experiment 5> Here, a magnetic tape was manufactured by internally adding the above-described ligand-containing anti-seizure agent to the back coat layer formed on the side opposite to the magnetic layer.

Specifically, first, a so-called coating type magnetic layer was formed on a 7 μm-thick polyethylene terephthalate film in the same manner as in Experiment 1. And
The following composition is prepared: carbon black (average primary particle size 50 nm) 100 parts by weight Thermoplastic polyurethane resin (average molecular weight 20,000) 60 parts by weight Vinyl chloride-vinyl acetate copolymer 60 parts by weight Olive oil 5 parts by weight Mixed solvent ( Methyl ethyl ketone / methyl isobutyl ketone / toluene = 2: 1: 1) 1150 parts by weight This composition was mixed in a ball mill for 10 hours, and then a curing agent composed of polyisocyanate 3.5 parts by weight Ligand 25 parts by weight was added. Then, the mixture was further mixed for 30 minutes, and the thus-obtained back coat layer coating material was applied to the surface of the polyethylene terephthalate film opposite to the magnetic layer forming surface so that the thickness after drying was 0.8 μm. .

Thereafter, the magnetic tape was dried and calendered, and heat treatment and cutting for accelerating curing were performed in the same manner as in Experiment 1.

The ligands used here are Compound 1 to Compound 8 shown in Chemical Formula 22, as in Experiment 1.

Then, each of the above-described ligands and the magnetic tape internally added to the back coat layer was incorporated into a cassette shell to form a cartridge, and the same evaluation as in Experiment 1 was performed. For the purpose of comparison, the same evaluation was performed on a magnetic tape to which no ligand was added. Table 7 shows the results of these evaluations.

[0173]

[Table 7]

As shown in Table 7, in the magnetic tape in which the ligand was not internally added to the back coat layer, the level was greatly reduced, and burn-in was generated on the surface of the magnetic head. On the other hand, in each of the magnetic tapes in which Compound 1 to Compound 8 were internally added to the back coat layer, the level reduction was suppressed, and burn-in on the surface of the magnetic head was not observed.

The drawing of the magnetic head after recording / reproducing on the magnetic tape with the ligand added thereto, based on a micrograph, is the same as FIG. 2, and the ligand is added internally. Drawing the magnetic head after performing recording and reproduction on a magnetic tape that is not based on a micrograph,
It became the same as FIG.

From the above results, it was found that the use of a magnetic tape in which a ligand, that is, a phenylhydroxylamine compound was internally added to a back coat layer, could prevent the generation of burn-in on a magnetic head. Was.

<Experiment 6> Here, a titanate coupling agent was added to the so-called coating type magnetic layer together with the above-described ligand to prepare a magnetic tape.

Specifically, first, the following composition was prepared, and 100 parts by weight of Fe-based metal ferromagnetic powder (coercive force: 160 kA / m, saturation magnetization: 145 Am ² / kg, specific surface area: 51 m ² / g, length: Shaft length 0.08 μm, needle ratio 3) Polyvinyl chloride resin (trade name MR110, manufactured by Zeon Corporation) 14 parts by weight Polyester polyurethane resin (manufactured by Toyobo) 3 parts by weight Al ₂ O ₃ 5 parts by weight Titanate coupling agent 3 parts by weight Stearic acid 1 part by weight Heptyl stearate 1 part by weight Methyl ethyl ketone 150 parts by weight Cyclohexanone 150 parts by weight After kneading the composition into an extruder,
The mixture was dispersed in a sand mill for 6 hours. Then, a magnetic coating material was prepared by adding 3 parts by weight of polyisocyanate and the ligand in the amounts shown in Table 8 to the obtained coating material.

The magnetic paint thus obtained was applied on a 7 μm-thick polyethylene terephthalate film so that the thickness became 6.5 μm. Subsequently, the formed magnetic coating film was subjected to an orientation treatment using a solenoid coil, and then dried, calendered, and cured to form a magnetic layer.

Next, the following composition was prepared: 100 parts by weight of carbon black (Asahi # 50) 100 parts by weight of polyester polyurethane resin (Nipporan N-2304) 500 parts by weight of methyl ethyl ketone 500 parts by weight of toluene A back coating was prepared by kneading and dispersing, and the back coating was applied to the surface of the nonmagnetic support opposite to the side on which the magnetic layer was formed, and dried to form a backcoat layer.

The original tape on which the magnetic layer and the back coat layer were formed was cut into a width of 8 mm to complete a magnetic tape.

The ligand to be internally added to the magnetic layer is any one selected from Chemical Formula 22, as in Experiment 1. Specifically, Compounds 1 to 8 represented by Chemical Formula 22 were used.

Further, titanate-based coupling agents include:
The compounds shown in Chemical formulas 27 to 31 were used.

[0184]

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[0185]

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[0186]

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[0187]

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[0188]

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Then, the above-described ligands and titanate-based coupling agents were combined, and magnetic tapes internally added to the magnetic layer were respectively incorporated into cassette shells to form cartridges. The evaluation of the level down was performed in the same manner as the above. Table 8 shows the results. Table 8 also shows the evaluation results of a magnetic tape containing only a titanate-based coupling agent and a magnetic tape containing only a ligand.

[0190]

[Table 8]

As a result of the evaluation, in the case of a magnetic tape in which a ligand and a titanate coupling agent were combined and internally added to a magnetic layer, a magnetic tape in which only a ligand was internally added to a magnetic layer or a titanate-based cup Compared with a magnetic tape in which only a ring agent is internally added to a magnetic layer, sticking of a seizure to the surface of the magnetic head is prevented, and the level reduction is suppressed as shown in Table 8.

From this, it was found that when a ligand was used in combination with a titanate-based coupling agent, the effect of preventing the sticking of seizures by the ligand was more remarkably exhibited.

In this case, the internal addition amount of the ligand is varied in various ways. As shown in Table 8, the internal addition amount of the ligand is 0.1.
When the amount is as small as 05 parts by weight, the result is not much different from the case where the ligand is not internally added.

Further, the leveling down is suppressed as the internal addition amount of the ligand increases, but when the ligand is added in excess of 10 parts by weight, the dispersibility of the magnetic powder decreases. Therefore, the internal addition amount of the ligand is 0.3 to 100 parts by weight of the magnetic powder.
20 parts by weight, more preferably 0.3 to 10 parts by weight.

In this case, the type of the titanate-based coupling agent is also changed, and all of them have sufficient effects. However, there are some differences in the degree of the effects. This difference is considered to be due to the difference in the adsorptivity of the titanate-based coupling agent to the magnetic powder.

Examination of Cleaning Tape Next, in Experiments 7 to 9, the effect of holding the phenylhydroxylamine compound on the cleaning tape was examined.

<Experiment 7> 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 7 μm-thick polyethylene terephthalate film so that the thickness after drying was 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, compounds 1 to 8 represented by the above-mentioned formula 22 were used.

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, the same evaluation was performed on a cleaning tape having no ligand added to the cleaning layer.

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 9 together with the type of ligand used.

[0204]

[Table 9]

As shown in Table 9, when a cleaning tape in which a ligand was internally added to a cleaning layer was run on a VCR, cleaning was performed in which the ligand was not applied to the cleaning layer and the cleaning layer was not internally added. Compared to running the tape on a VCR, the level down was greatly restored.

<Experiment 8> A cleaning tape was prepared in the same manner as in Experiment 7, except that no ligand was internally added to the cleaning layer and, after 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 7, and the concentration of the solution was 10 mM. The solvent is a mixed solvent of toluene and alcohol.

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 7, and the recovery of output 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 10 shows the results together with the types of ligands used.

[0208]

[Table 10]

As shown in Table 10, 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 9> 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 prepared 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 7, and the recovery of output was measured. . Table 11 shows the results together with the types of ligands used.

[0212]

[Table 11]

As shown in Table 11, when the cleaning tape in which the non-woven fabric was impregnated with the ligand was run on a video deck, the level reduction was greatly recovered.

From the results of Experiments 7 to 9, it was found that the phenylhydroxylamine compound (ligand) was suitable as a cleaning tape cleaning agent. It was also found that this ligand exerts a good cleaning effect when it is applied to the surface of the support or the surface of the cleaning layer, and when it is internally added to the cleaning layer.

[0215]

As is clear from the above description, when a ligand having a complex forming ability with a metal, that is, a phenylhydroxylamine compound is held on a magnetic recording medium, the generation of a seizure on a magnetic head is prevented. Can be prevented.

For this reason, when the magnetic recording medium according to the present invention is used, the sliding time is increased in order to achieve a long recording time,
Alternatively, even if the scanning speed is increased, the spacing loss is suppressed, and an increase in the error rate is prevented.

When a ligand capable of forming a complex with a metal, that is, a phenylhydroxylamine compound is used as a cleaning agent for a cleaning tape, seizure adhered to the magnetic head may cause wear and damage to the magnetic head. It can be removed without.

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.

[Brief description of the drawings]

FIG. 1 is a plan view showing a sliding surface of a magnetic head with a magnetic tape.

FIG. 2 is a plan view showing a sliding surface of a magnetic head with a magnetic tape after recording and reproduction are performed on the magnetic tape to which the present invention is applied.

FIG. 3 is a plan view showing a sliding surface of a magnetic head with a magnetic tape after recording / reproducing on a conventional magnetic tape.

[Explanation of symbols]

1, half magnetic core, 3 ferromagnetic metal thin film, 4
Burn-in

Continued on the front page (72) Inventor Haruo Watanabe 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (72) Inventor Ken Takeshi 6-35-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Sonny shares Inside the company (72) Inventor Kenichi Kurihara 6-7-35 Kita Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation

Claims (11)

[Claims] 1. A magnetic recording medium comprising at least a magnetic layer formed on a non-magnetic support, wherein a magnetic recording medium containing a phenylhydroxylamine compound is held. 2. The method according to claim 1, wherein the phenylhydroxylamine compound is represented by the following chemical formula 1.
The magnetic recording medium according to the above. 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-seizure agent is applied to the surface of the magnetic layer. 3. The magnetic recording medium according to claim 2, wherein the magnetic recording medium is internally added in the layer. 4. The magnetic recording medium according to claim 3, wherein a titanate-based coupling agent is applied to the surface of the magnetic layer, or is internally added to the magnetic layer. 5. The magnetic material according to claim 4, wherein the titanate-based coupling agent has introduced at least one of an amino group, a phosphate group, an acyl group, a hydroxyl group, a carbonyl group, and an alkyl group. recoding media. 6. The magnetic recording medium according to claim 3, wherein a carboxylic acid is applied to the surface of the magnetic layer, or is internally added to the magnetic layer. 7. The magnetic layer according to claim 2, wherein the magnetic layer is a metal magnetic thin film, a carbon film is formed on the metal magnetic thin film, and the anti-seizing agent is applied to the surface of the carbon film. Magnetic recording medium. 8. A compound containing phosphorus represented by at least one of the following chemical formulas (2), (3), (4), and (5): 7. The magnetic recording medium according to 7. Embedded image Embedded image Embedded image Embedded image 9. A backcoat layer is formed on the surface of the nonmagnetic support opposite to the surface on which the magnetic layer is formed, and the anti-seizure agent is applied to the surface of the backcoat layer, or 3. The magnetic recording medium according to claim 2, wherein the magnetic recording medium is internally added to the back coat layer. 10. A cleaning tape comprising a support and an anti-seizure agent containing a phenylhydroxylamine compound. 11. The cleaning tape according to claim 10, wherein the compound is represented by at least one selected from the following chemical formula 6. Embedded image