KR19980019158A - Magnetic recording medium and cleaning tape - Google Patents

Abstract

The present invention provides a magnetic recording medium which prevents the combustion products from remaining on the magnetic head, reduces the spacing loss, and increases the error rate even when the friction time is increased or the scan speed is increased to perform the long time recording . The present invention also provides a cleaning tape for removing combustible substances adhering to a head without wear and tear of the magnetic head.

These are magnetic recording media and cleaning tapes having an antisticking agent containing a compound containing a pyridine skeleton and two or more ligand sites. Or a magnetic recording medium and a cleaning tape on which an anti-adhesion agent containing a diketone compound is held. In addition to the above-mentioned compounds, the anti-sticking agent may include a titanium coupling agent, a carboxylic acid, and a phosphorus-containing compound.

Description

Magnetic recording medium and cleaning tape

The present invention relates to a magnetic recording medium capable of preventing a substance from adhering to a magnetic head, and a cleaning tape for removing an adherend of a magnetic head.

In the field of magnetic recording media, long time recording is required to meet high capacity recording particularly in the field of data cartridges and digital video recorders for hard disk backup. The thickness of the tape is reduced or the cassette shell is deformed to increase the effective length of the tape, thereby achieving long-time recording.

The data cartridge is generally recorded and reproduced in a helical scan manner. However, in the helical scan method, the magnetic surface of the tape passes through the magnetic head at a high speed, so that the head is pressurized at high temperature during traveling of the magnetic tape, and the temperature of the head tends to be high on the surface of the magnetic tape.

If the contact time is prolonged or the scan speed is increased and the recording is performed for a long time, the generation and attachment of the burning material to the surface of the magnetic head will become even worse.

Particularly, in the high temperature and high humidity environment, the polishing of the magnetic tape is reduced, and the metal oxide produced by the friction is hardened by heating and adhered to the surface of the head without being polished by the tape. There is a problem that a space (spacing) is generated between the magnetic tape and the head due to the accumulated combustibles so that the signal output between them interferes with each other.

Presently, the tape is subjected to super calander treatment to improve the surface property to improve the magnetic conversion property and reduce the spacing loss. However, such a treatment increases the friction between the magnetic tape and the magnetic head to increase the generation and adhesion of the magnetic head surface combustible material.

In order to prevent the generation and adherence of combustibles on the magnetic head, a reducing agent such as a derivative of ascorbic acid is added to the magnetic tape with an antioxidant and a lubricant is added to the tape at a higher concentration to further reduce surface friction. There were some things to try. However, once the combustible is formed on the surface of the tape, the combustible is strongly adhered to the surface and is rarely removed by the treatment.

Alternatively, the burned material attached to the magnetic head was removed by a number of methods, such as using a cleaning tape to physically grind the head and continuously polishing the magnetic head by a cleaning roll mechanism. For example, Japanese Patent Application Laid-Open No. 57-208626 proposes a glue tape produced by applying α-Al ₂ O ₃ or Cr ₂ O ₃ fine powder having a Moh hardness of 8 or more with an abrasive agent on a polyester film base material together with a binder resin have.

The abrasive grains used for the physical polishing as described above are excellent in polishing activity because they have a large hardness and polish or damage the magnetic head itself while removing the combustible from the head. A recording / reproducing magnetic head of an 8 mm video tape or a digital video tape has a gap of 0.3 m or less, and the tape runs at a high speed in such an interval. Such a magnetic head is easily damaged by a mechanical impact and is liable to be worn or damaged when it is pressed by the abrasive grains.

As a solution to the above-mentioned problem, Japanese Patent Publication No. 8-001695 proposes a method of reducing the polishing of a magnetic head by controlling the particle diameter of the abrasive grains. However, even if controlling the particle size of the abrasive grain particles it is made of α-Al ₂ O ₃ or Cr ₂ O ₃ or the high-hardness abrasive material of the magnetic head can not be avoided.

Various treatments have been performed on the recording medium or the cleaning tape to remove or reduce the combustibles attached to the magnetic head, but since satisfactory results have not been obtained, research for solving the above problem needs to be continued.

The present invention relates to removing the adherence of a remaining magnetic head when the magnetic tape passes through the head at a high speed, without causing the combustible to remain on the magnetic head even if the friction time is extended or the scan time is increased, And to prevent the error rate from being increased. Further, the present invention is to provide a cleaning tape for removing the combustible adhering to the head from the head, while preventing the head from being polished or damaged.

1 is a plan view of a surface of a magnetic head used for recording /

FIG. 2 is a plan view of a magnetic head shown on the basis of an electron microscope photograph of a magnetic head used for recording / reproducing on a magnetic tape manufactured according to the present invention. FIG.

FIG. 3 is a plan view of a magnetic head, which is based on an electric microscope photograph, of a magnetic head used for recording / reproducing on a magnetic tape not containing an anti-

[0002] DESCRIPTION OF REFERENCE NUMBERS

1. magnetic core end 2. Magnetic core end

3. Ferromagnetic metal thin film 4. Combustible material

The magnetic recording medium of the present invention is a magnetic recording medium in which at least a magnetic layer is formed on a nonmagnetic support and the adhesion preventing agent containing a compound having a pyridine skeleton and two or more ligand sites or a diketone compound (hereinafter referred to as a ligand) ≪ / RTI >

As the compound (ligand) having the pyridine skeleton and two or more ligand sites of the compound for magnetic recording medium of the present invention, there is one or more compounds selected from the compounds represented by the following formulas (19) to (22).

In the formulas, R ¹ to R ^{4 each} represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group, Wherein two adjacent pairs of groups may together form an aromatic ring and X is selected from the group consisting of a hydroxyl, a Schiff base, an ester, a carboxylic acid, an alcohol, an amine, an amide, an imide and a heterocyclic aromatic containing polar group Is selected.

Wherein R ⁵ to R ¹⁰ are each a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group, and an alkyl group, And two adjacent pairs of groups may together form an aromatic ring, and Y is OH, SH or NH ₂ .

Wherein R ¹¹ to R ¹⁸ are a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group substituted with the above- And two adjacent pairs of the groups may form an aromatic ring together.

Wherein R ¹⁹ to R ^{26 each} represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group, an aryl group and a heterocyclic aromatic group And two adjacent pairs of the groups may form an aromatic ring together.

As the diketone compound (ligand) for the magnetic recording medium of the present invention, there is a compound of the following formula (23) or (24).

In the formulas, R ²⁷ to R ^{29 each} represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group, .

The ligand has a property of forming a complex with a metal. That is, when added to a magnetic recording medium, it forms a complex that is easily lost from the surface of the magnetic head together with the metal oxide produced on the surface of the magnetic head. By such a method, the metal oxide can be removed from the magnetic head. That is, when the present invention is practiced, it is possible to prevent the output of the tape from being reduced due to the space loss due to the accumulation of combustibles in the magnetic head, and to keep the error rate low.

The magnetic recording medium of the present invention is not limited to a specific structure. These structures may have a coated magnetic layer or a deposited magnetic layer.

When the magnetic layer is made of a coating composition or is made of a magnetic paint containing a magnetic powder and a binder as a main component, the anti-sticking agent may be applied to the surface of the magnetic layer or may be added as a component to the magnetic layer.

The anti-adhesion agent added to the coated magnetic layer may preferably contain a titanate-based coupling agent or carboxylic acid in addition to the ligand.

Since the ligand has complex formation properties in which it is bonded to a metal atom, it is bonded to or attached to magnetic particles contained in the magnetic layer to form a complex compound. When the ligand is attached to the magnetic particles to form a complex with it, the metal oxide can not be removed because it can not form a complex with the metal oxide attached to the magnetic head.

When the ligand coexists with a titanate-based coupling agent or a carboxylic acid, it is possible to prevent the attachment of the ligand to the magnetic particles because the titanate or the carboxylic acid is easily adsorbed on the surface of the magnetic particle and thus the ligand is not allowed to adhere to the magnetic particle. By such a method, the ligand can effectively form a complex with the metal oxide on the surface of the magnetic head.

The anti-adhesion agent added to the coated magnetic layer may be an organic salt of the ligand. Organic salts include organic salts of pyridine derivatives of the following formula (25) or organic salts of phenanthrene derivatives of the following formula (26).

Wherein R ¹¹ to R ¹⁸ are a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group substituted with the above- And two adjacent pairs of the groups may form an aromatic ring together with R ^* being substituted with a hydrogen atom or a halogen atom or a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group or a sulfonate group A hydrogen atom or a halogen atom or an aryl group substituted with a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group or a sulfonate group, and an alkyl group coupled with a heterocyclic aromatic group.

Wherein R ¹⁹ to R ^{26 each} represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group, an aryl group and a heterocyclic aromatic group And two adjacent pairs of the groups may form an aromatic ring together and R is a hydrogen atom or a halogen atom or a group selected from the group consisting of a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group or a sulfonate group An alkyl group, a hydrogen atom or a halogen atom, or an aryl group substituted with a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group or a sulfonate group, and an heterocyclic aromatic group.

The ligand can form a salt with the carboxylic acid added to the magnetic layer as a lubricant. In this case, the dispersion of the lubricant is interfered to such an extent that the lubricating activity is somewhat inhibited. This increases the friction rate of the magnetic layer and reduces the steel durability.

As a countermeasure to the above problem, the organic salt of the ligand can be applied to the surface of the magnetic layer or added in the layer. Next, instead of forming a salt with a carboxylic acid to be added to the magnetic layer as a lubricant, the lubricant moves smoothly toward the surface of the magnetic recording medium by the ligand. As a result, the friction ratio of the magnetic layer is kept low. The magnetic recording medium in which the magnetic layer contains an organic salt of a ligand is excellent in steel durability.

Further, when the magnetic recording medium has a vapor-deposited magnetic layer, that is, a metal magnetic film, the magnetic layer is coated with a carbon film which is further coated with an anti-adhesion agent.

Furthermore, when the antistocking agent is applied to the surface of the carbon film, the resulting magnetic layer prevents the attachment of the combustible on the magnetic head, so that the antistacking agent is a phosphorus compound, that is, a compound selected from the following formulas (27), .

In the formula, R ³⁰ -R ³² represents a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group substituted with the above- Click aromatics.

In the formulas, R ^{33 to} R ³⁵ may be the same or different and each represents a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group, Click aromatics.

In the formulas, R ^{36 to} R ^{38 each} represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group substituted with the aforementioned atoms and groups, Click aromatics.

In the formulas, R ^{39 to} R ^{41 each} represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group substituted with the aforementioned atoms and groups, Click aromatics.

The antifouling agent layer may be formed on the opposite side of the undercoat layer on one side of the nonmagnetic support, that is, on the side where the antifouling agent of the other layer is located, or may be present as the only antifouling layer without using the antifouling agent on the other side. In the latter case, similarly to the above, an anti-sticking agent may be applied to the surface of the primer layer or added to the primer layer. Generally, a magnetic tape is wound and introduced into a cassette. That is, when the antifouling agent is applied to the primer layer, the antifouling agent moves to the friction surface of the magnetic head. That is, the anti-adherence agent has the effect of preventing the generation of combustion products as in the tape added to the magnetic layer.

The cleaning tape of the present invention is characterized in that an anti-adhesion agent containing a compound having a pyridine skeleton and two or more ligand sites or a diketone compound is observed in the support.

As the ligand to be used for the cleaning tape of the present invention, there is one or more compounds selected from the compounds of the above formulas (19) to (22).

Further, as the diketone compound used for the cleaning tape of the present invention, there is one or more compounds selected from the compounds of the above formulas (23) and (24).

Since the ligand has a property of forming a complex in the presence of metal atoms as described above, when a cleaning tape containing one of these compounds runs on a magnetic head to which a combustible is attached, the ligand is bonded to the surface of the magnetic head And reacts with the resulting metal oxide to form a complex. These complexes are easily removed away from the surface of the magnetic head.

As described above, when a ligand having a property of forming a complex in combination with a metal, that is, a compound having a pyridine skeleton and two or more ligand sites or a diketone compound, is used in a magnetic recording medium, Generation of combustion products on the magnetic head is suppressed by these passing magnetic recording media.

The magnetic recording medium of the present invention prevents the combustible from remaining on the ceramic head when the friction time is prolonged or the scan speed is increased for long time recording, thereby reducing the spacing loss and preventing the error rate from being increased.

Furthermore, a ligand having a property of forming a complex with a metal, that is, a compound having a pyridine skeleton and two or more ligand sites or a diketone compound as a cleaning agent for a cleaning tape, Remove the adhered flue from the head.

That is, the cleaning tape is suitable for cleaning a magnetic head of a recording / reproducing system having a gap of 0.3 m or less in width, whereby the tape travels at high speed in the magnetic head.

To illustrate the magnetic recording medium of the present invention, reference is made to the following examples. The magnetic recording medium of the present invention is produced after using an anti-sticking agent containing a compound or a diketone compound (ligand) having at least one magnetic layer formed on a nonmagnetic support and having a pyridine skeleton and two or more ligand sites.

Examples of the ligand used in the present invention include a pyridine derivative or a pyridine skeleton and a compound represented by the following formula (31), a quinoline derivative represented by the following formula (33), and a phenanthroline derivative represented by the following formula (34)

In the formula, R ¹ -R ⁴ represents a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group substituted with the above- Wherein two adjacent pairs of groups may together form an aromatic ring and X is selected from the group consisting of a hydroxyl, a Schiff base, an ester, a carboxylic acid, an alcohol, an amine, an amide, an imide and a heterocyclic aromatic containing polar group Is selected.

Wherein R ⁵ to R ¹⁰ are each a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group, and an alkyl group, And two adjacent pairs of groups may together form an aromatic ring, and Y is OH, SH or NH ₂ .

Wherein R ¹¹ to R ¹⁸ are a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group substituted with the above- And two adjacent pairs of the groups may form an aromatic ring together.

Wherein R ¹⁹ to R ^{26 each} represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group, an aryl group and a heterocyclic aromatic group And two adjacent pairs of the groups may form an aromatic ring together.

The pyridine derivatives of formula (31) are described in detail below. Substituent X can be represented by chemical nomenclature as -RCNOH for the hydroxym, -CHNR or -RCHNR for the Schiff base, -COOR for the ester and -COOH or -RCOOH for the carboxylic acid. Also, X is for -ROH or -OH, an amine for the alcohol _{-NH 2 R, -NHR, -NRR,} -RNH 2, -RNHR or -RNRR, may already be represented by -CONRR for de. R represents an alkyl group, an aryl group, and a heterocyclic aromatic compound, and an alkyl group substituted with a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group or a sulfonate group, An aryl group and a heterocyclic aromatic compound. When the chemical name includes plural Rs, Rs may be the same or different from each other. When the substituent X includes an aromatic ring, the ring may be a ring formed by condensation with a 5-membered ring or a 5-membered ring in which the benzene ring is the same, or a derivative thereof, or a pyridine ring.

Substituent X is preferably, for example, -CH ₂ NH ₂ , -COOH, -COOCH ₃ , -COOC ₂ H _5, -CONHC ₂ H ₅ , -OH, substituents of the following formulas 35 and 36, And a substituent group including a pyridine ring. Further, when the substituent X is triazine or a derivative thereof, the compounds included in the anti-adhesion agent include, for example, the compounds of the formulas 38 and 39, particularly the compounds of the formulas 40 and 41. When the substituent X is a 5-membered ring formed with nitrogen and an oxygen atom, the compounds included in the anti-adhesion agent include, for example, the compounds represented by Chemical Formulas 42 and 43. When the substituent X is a compound obtained by condensation of a 5-membered ring having nitrogen and oxygen atoms with a benzene ring, compounds represented by the following chemical formulas (44) and (45) are included in the anti-

-CH ₂ CH ₂ NHCH ₂ CH ₂ CH ₂ OH

In the formulas, R ⁴² to R ^{47 each} represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group, And two adjacent pairs of the groups may form an aromatic ring together.

In the formulas, R ⁴⁸ to R ^{53 each} represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group, And two adjacent pairs of the groups may form an aromatic ring together.

In the formulas, R ⁵⁴ to R ^{59 each} represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group, and an alkyl group, an aryl group and a heterocyclic aromatic And two adjacent pairs of the groups may form an aromatic ring together.

Wherein R ⁶⁰ to R ^{65 each} represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group substituted with the above- And two adjacent pairs of the groups may form an aromatic ring together.

In the quinoline derivatives of formula (32), when R ^{10 in the} substituent R ⁵ -R ¹⁰ is substituted by a 5-membered ring formed with nitrogen or an oxygen atom, a suitable quinoline derivative is the compound of formula 46. Alternatively, when R < ¹⁰ > is substituted with a substituent X formed by condensation of a benzene ring with a 5-membered ring formed together with nitrogen or oxygen atom, a suitable quinoline derivative is the compound of formula 47. [

In the formulas, R ⁶⁶ to R ^{73 each} represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group, And two adjacent pairs of the groups may form an aromatic ring together.

The pyridine derivative of the above formula (33) represents a pyridine derivative derived when the substituent X of the pyridine derivative of the formula (3) is another pyridine derivative. The phenanthroline derivative of the formula (34) is derived after the substituents R ¹⁴ and R ¹⁵ of the pyridine derivative of the formula (33) are bonded to form a ring therebetween.

The diketone compound (ligand) used in the present invention is 1,3-diketone of the following formula (48) and 1,5-diketone of the following formula (49).

In the formulas, R ²⁷ to R ^{29 each} represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group, .

Wherein R ⁷⁴ to R ⁷⁹ are a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group, and an alkyl group, . Two adjacent pairs of groups may together form an aromatic ring.

When at least one substituent R ²⁷ -R ²⁹ of formula 48 is a heterocyclic aromatic compound, at least one substituent R ²⁷ -R ²⁹ is a compound of formula 50 (plan) or a compound of formula 51 (thiophene).

The compound of the above formula (49) wherein two adjacent groups form a ring between them is the compound of the formula (52).

The ligands included in the anti-adhesion agent may be added variously, singly or in combination as described above. When added to the applied magnetic or subbing layer, the ligand can be chemically bonded to the anti-adhesion agent.

The magnetic recording medium to which the present invention is applied is not limited to a specific form and may have a magnetic layer by coating or vapor deposition. When the magnetic layer is produced by coating, that is, when it is produced from a coating material containing magnetic powder and a binder, the above-described anti-adhesion agent can be applied on the magnetic layer or added in the magnetic coating.

When the anti-adhesion agent is applied to the surface of the magnetic layer, it is preferably used in an amount of 10 mg to 10 g per 1 m ^{2 of the} magnetic layer.

When the anti-adhesion agent is added to the magnetic layer, it is preferably used in an amount of 0.2 to 20 parts by weight based on 100 parts by weight of the magnetic powder. If the addition amount of the anti-adherent agent is less than the above value, adhesion of the combustible material on the magnetic head is not satisfactorily suppressed. On the contrary, when the addition amount of the anti-adherence agent exceeded the above value, the running property of the obtained magnetic recording medium was inferior, and the dispersing power of the magnetic powder was decreased, and excellent electromagnetic conversion could not be obtained.

When an anti-adhesion agent is added to the magnetic paint to be applied, it is preferable to use a titanate-based coupling agent or a carboxylic acid together to prevent the ligand from adhering to the magnetic powder. The ligand has a complex forming property in the presence of the metal ion, so that the ligand binds or adheres to the magnetic particles contained in the magnetic layer to form a complex.

When the ligand binds to or adheres to the magnetic particles to form a complex therewith, it does not form a complex with the metal oxide attached to the magnetic head, and thus the cleaning activity for the metal oxide is lost.

In such a case, when the titanate-based coupling agent or the carboxylic acid coexists with the anti-adhesion agent, these compounds are more easily attached to the surface of the magnetic particles than the ligand to prevent the ligand from attaching to the magnetic particles. That is, these compounds effectively contribute to the complex formation of the ligand with the metal oxide on the magnetic head.

Preferred titanate-based coupling agents include compounds comprising at least one of amino, phosphate ester, carboxylic acid ester, acyl, carbonyl, hydroxyl and alkyl groups. Examples of these coupling agents include compounds represented by the following formulas (53) to (57). The titanate-based coupling agent specified herein prevents binding and adsorption of ligands and magnetic particles, as well as enhancing the dispersibility of magnetic powders.

The titanate-based coupling agent may be used alone or in combination.

In the titanate-based coupling agent to be added to the magnetic layer, it is only necessary to add the coupling agent to the magnetic paint while preparing the coating. When doing so, it is important to add a titanate-based coupling agent and then add a ligand. Specifically, a titanate-based coupling agent is combined with a magnetic powder, a binder and an organic solvent, and kneaded and dispersed. The ligand is then added to the mixture. Alternatively, the magnetic powder is pretreated with a titanate-based coupling agent, and the pretreated magnetic powder is combined with a binder and an organic solvent, and mixed and dispersed. The ligand is added to such a yield.

The amount of the titanate-based coupling agent added to the magnetic layer is preferably 0.2 to 20 parts by weight of the titanate-based coupling agent per 100 parts by weight of the magnetic powder. If the addition amount of the coupling agent is less than the above value, the coupling agent can not effectively prevent the ligand from adhering to the magnetic particles, which would impair the ligand's protective activity on the accumulation of the combustible on the magnetic head. In addition, the dispersing power of the magnetic powder will not be sufficiently improved. On the other hand, when the addition amount of the titanate-based coupling agent exceeds the above-mentioned value, the majority of the functional groups of the coupling agent remain unreacted with the binder and the magnetic powder, and these unreactive functional groups mutually interact to damage . More preferably, the coupling agent is added in the range of 1.0 to 5.0 parts by weight based on 100 parts by weight of the oily powder.

Any carboxylic acid can be used when the pKa is 6 or less and examples thereof include formic acid, acetic acid, propionic acid, acetic acid, valeric acid, caproic acid, enantic acid, caprylic acid, perrolactonic acid, capric acid, Saturated fatty acids such as lauric acid, tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, arachic acid and behenic acid, acrylic acid, crotonic acid, isocrotonic acid, Unsaturated fatty acids such as oleic acid, undecylic acid, oleic acid, elaidic acid, tetralic acid, erucic acid, brassidic acid, sorbic acid, linoleic acid, linolenic acid and arachidonic acid; unsaturated fatty acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, Unsaturated fatty acid-containing dicarboxylic acids such as saturated fatty acid-containing dicarboxylic acids such as pimelic acid, suberic acid, azelaic acid and sebacic acid, maleic acid and fumaric acid, aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid And tricarboxylic acids such as citric acid, and the like.

Particularly, oleic acid and myristic acid are useful because they have lubrication activity. These carboxylic acids may be used alone or in combination.

When the carboxylic acid is added to the magnetic layer, it is preferable to add 1 to 3 parts by weight to 100 parts by weight of the magnetic powder.

The titanate-based coupling agent or the carboxylic acid compound may be combined with an antistatic agent added to a coating material to be a magnetic layer or an antistatic agent applied to the surface of a magnetic layer prepared by coating or vapor deposition. However, when the ligand is added to the coating to be the magnetic layer, the ligand should be most precisely prevented from adhering to the magnetic powder, so that when the anti-adhesion agent is added to the coating, the titanate-based coupling agent or carboxylic acid is added to the anti- Is more effective.

Moreover, when the ligand is added to the coating to be the coated magnetic layer, the ligand, especially the pyridine skeleton and the organic salt of the compound having two or more ligand sites, can be used because the ligand is less attached to the lubricant. However, the ligand can react with the added carboxylic acid to act as a lubricant in the magnetic layer to produce a salt. In this case, the lubricant decreases the dispersing power, hinders the lubricating activity, and increases the friction coefficient of the magnetic layer. That is, the steel durability of the obtained product is lowered.

As a countermeasure to the above problem, the organic acid salt of the ligand can be applied to the surface of the magnetic layer or added in the layer. That is, instead of forming a salt with the carboxylic acid to be added to the magnetic layer as a lubricant, the ligand causes the lubricant to move smoothly toward the surface of the magnetic recording medium. As a result, the friction ratio of the magnetic layer is kept low. Thus, the organic acid salt of the ligand does not easily react with the metal oxide on the surface of the magnetic head to form a complex, and the lubricant activity of the lubricant is maintained by the organic acid salt.

When the magnetic recording medium sees the organic acid salt of the ligand, the result is that no combustion is formed on the surface of the magnetic head, and the steel durability is excellent even when the contact time or the scanning speed is prolonged or increased.

Examples of the organic acid salt of the ligand include an organic acid salt of a bipyridine derivative represented by the following formula (58) or an organic acid salt of a phenanthrene derivative represented by the following formula (59).

Wherein R ¹¹ to R ¹⁸ are a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group substituted with the above- And R ^* is a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group or a sulfonate group, and the two adjacent pairs of the groups may form an aromatic ring together. An aryl group substituted with an alkyl group, a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group or a sulfonate group, and an alkyl group coupled with a heterocyclic aromatic group.

Wherein R ¹⁹ to R ^{26 each} represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group, an aryl group and a heterocyclic aromatic group And R ^* is a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group or a sulfonate group, and the two adjacent pairs of the groups may form an aromatic ring together. An aryl group substituted with an alkyl group, a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group or a sulfonate group, and an alkyl group coupled with a heterocyclic aromatic group.

The organic acid which binds with the ligand to form a salt is not limited to a specific acid as long as the condition that the pKa is 3 to 7 is satisfied. The same monocarboxylic acid as used in the carboxylic acid or lubricant described above may be used.

The organic acid salt of the ligand is added to the coated magnetic layer or to the surface of the magnetic layer. When added to the magnetic layer, it is added in an amount of 0.3 to 20 parts by weight based on 100 parts by weight of the magnetic powder. When applied to the magnetic layer surface, the addition amount is preferably controlled to 10 mg to 10 g per m ² of the magnetic layer. If the addition amount or the application amount of the organic acid salt of the ligand is less than the above value, the effect of inhibiting adhesion of the combustible on the magnetic head is unsatisfactory. On the contrary, if the addition amount or the application amount of the organic acid salt exceeds the above value, the performance of the obtained magnetic recording medium will be deteriorated.

On the other hand, when the magnetic recording medium is a deposited magnetic layer, that is, when the magnetic layer is made of a magnetic metal thin film, it is preferable to form a carbon film coated with an anti-adhesion agent on the magnetic layer. The addition of the anti-adhesion agent is preferably controlled so as to have the same effect as in the coated magnetic layer.

Furthermore, when the anti-adherence agent is applied to the surface of the carbon film, one or more phosphorus-containing compounds selected from the following formulas (60) to (63) may be combined with an anti-

In the formulas, R ³⁰ to R ^{32 each} represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group, .

In the formulas, R ³³ to R ^{35 each} represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group, .

In the formulas, R ³⁶ to R ³⁸ represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group, .

In the formulas, R ³⁹ to R ^{41 each} represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group, .

Although the coated magnetic layer can hold the above phosphorus-containing compound, it is more practical to apply the phosphorus-containing compound to the surface of the deposited magnetic layer.

The anti-sticking agent may be added to the lower layer on the non-magnetic support surface, i.e., the opposite side of the side where the magnetic layer is formed, irrespective of whether the magnetic layer contains the same antifouling agent. In this case, similar to the above, the antifouling agent may be applied on the surface of the primer layer or added to the primer layer. Generally, a magnetic tape is wound on a reel and introduced into a cassette. That is, when the antifouling agent is located on the undercoating layer, the antifouling agent moves to the friction surface of the magnetic head. That is, it has the effect of preventing the generation of combustibles in the same way as the tape to which the anti-adhesion agent is added to the magnetic layer. The anti-adherence agent will be added to the underlayer at the same rate as required when applied to the magnetic layer or when added to the magnetic layer.

The nonmagnetic support and the substance necessary for manufacturing the magnetic layer, that is, the necessary components of the magnetic recording medium of the present invention are not limited to a specific kind and can include the above-mentioned known compounds.

For example, the non-magnetic support or membrane substrate is preferably made of polyesters such as polyethylene terephthalate and polyethylene-2,6-naphthalate, polyolefins such as polypropylene, celluloses such as cellulose triacetate and cellulose diacetate, Resin, polyimide, polyamide, polycarbonate, and the like. The nonmagnetic support preferably has a thickness of 1.0 to 100 占 퐉, more preferably 2.0 to 70 占 퐉. The support may be made of a rigid body including a metal plate such as an aluminum alloy, a glass plate, and a ceramic. In this case, the surface of the film base can be treated with an oxide film or a Ni-P film as it is aluminized and hardened.

When the magnetic recording medium is a coated magnetic layer, a magnetic paint comprising a magnetic powder and a binder is applied to a nonmagnetic support to produce a magnetic layer. As the magnetic powder,? -Fe₂O₃, Fe₃O₄,? -Fe₂O₃And Fe₃O₄Of a bertholide compound, Co-containing γ-Fe₂O₃, Co-containing Fe₃O₄, Co-containing? -Fe₂O₃And Fe₃O₄And CrO < RTI ID = 0.0 >₂Is made to contain one or more metals such as Te, Sb, Fe, Bi, and the like.

As the magnetic powder, a ferromagnetic metal powder containing a metal such as Fe, Co, and Ni, and a ferromagnetic metal powder containing Fe-Co, Fe-Ni, Fe-Co-Ni, Fe- Fe-Ni-Si-Al, Fe-Ni-Si-Al, Fe-Ni-Al, Fe-Ni- Iron carbides and iron nitrides such as Al-Mn, Fe-Mn-Zn, Fe-Ni-Zn, Co-Ni, Co-P, Fe-Co-Ni- .

These ferromagnetic powders could be obtained by reducing oxides, hydroxyl compounds, inorganic or organic salts of the above-mentioned metallic elements in a reducing atmosphere or under water. During the production of the ferromagnetic metal powder, a suitable amount of a light metal element such as Al, Si, P, or B may be added to prevent the powder from being calcined during the reduction reaction, and to maintain the desired shape of the powder.

When the powder is immersed in an organic solvent and dried, the powder is immersed in an organic solvent, exposed to an oxidizing gas to be sprayed, dried, or directly exposed to an ejected oxidizing gas having a controlled partial pressure without using an organic solvent, So that safety against oxidation can be obtained. The oxide film formed on the surface may contain at least one element selected from the group consisting of Al, Si, Ca, Mg, Sr, Ba, B, S, Ti, Zn, Na, Zr, K, Y, La, Ce, Pr, Sm, Gd, Ge, Sn, Ga, and the like.

In addition to the above-mentioned oxides and paramagnetic metal powders, hexagonal flake ferrite is a magnetic powder. Hexagonal flake ferrites include M-, W-, Y- and Z-type barium ferrite, strontium ferrite, calcium ferrite and red ferrite. The coercive force of the powder can be controlled by adding Co-Ti, Co-Ti-Zn, Co-Ti-Nb, Co-Ti-Zn-Nb, Cu-Zr and Ni-Ti.

The magnetic powder may be used alone or in combination.

The magnetic powder is preferably treated in the following sizes.

The specific surface area of the particles is preferably 30-80m ² / g, more preferably 40-70 m ² / g. The magnetic powder having a specific surface area in the above range has fine particles, and the magnetic recording medium produced therefrom has high density and low noise recording properties.

Particularly when the shape of the magnetic particles is needle-like, the long axis of the needle-like particles is preferably 0.05-0.50 mu m and the axial ratio is 2-15. If the major axis of the needle-shaped particles is less than 0.05 mu m, the obtained powder is not easily dispersed in the coating material, whereas if the major axis exceeds 0.50 mu m, the magnetic tape produced therefrom has high noise. Furthermore, if the axial ratio of the needle-like particles is less than 2, the orientation of the magnetic powder decreases, and the output of the magnetic tape produced therefrom is reduced. Conversely, if the axial ratio of the needle-shaped particles exceeds 15, the output of the magnetic tape produced therefrom is reduced in the shortwave range.

When the magnetic powder is made of flake ferrite, it is preferable that the flake has a diameter of 0.01 to 0.5 mu m and a thickness of 0.001 to 0.2 mu m.

The above preferred long axis length, axial ratio, and flake diameter and thickness were calculated by measuring from more than 100 samples randomly selected in an electron microscope photograph.

As the binder to be added to the magnetic layer of the present invention, there is a known thermoplastic resin, a thermosetting resin, and a reactive resin used as a binder of a magnetic recording medium, and preferably has a molecular weight of 5000 to 10000.

Examples of the thermoplastic resin include a copolymer of vinyl chloride, vinyl acetate, vinyl propionate, vinyl alcohol, maleic acid, acrylic acid, ester acrylate, methacrylate, ester methacrylate, vinylidene chloride, acrylonitrile, methacryloyl Nitrile, styrene, methylstyrene, butadiene, ethylene, vinyl acetal, vinyl butyral, and vinyl pyrrolidone. Specifically, the reaction of vinyl chloride with vinyl acetate, of vinyl chloride and vinylidene chloride, of vinyl chloride and acrylonitrile, of ester acrylate and acrylonitrile, of ester acrylate, of vinyl chloride and of vinylidene chloride, of vinyl chloride Of acrylonitrile, of ester acrylate and acrylonitrile, of ester acrylate and vinylidene chloride, of ester methacrylate and vinylidene chloride, of ester methacrylate and vinyl chloride, of ester methacrylate and of ethylene , Copolymers of vinylidene chloride and acrylonitrile, acrylonitrile and butadiene, and polyvinyl butyral and styrene butadiene. In addition, it is also possible to use cellulose derivatives such as polyvinyl fluoride, polyamide resin and cellulose acetate butyrate, cellulose diacetate, cellulose triacetate, cellulose propionate and nitrocellulose, and cellulose derivatives such as polyurethane resin, Resins, and synthetic rubbers.

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

Polar functional groups can be added to one of the binders to enhance the dispersing power of the pigment.

Examples of the polar functional group include -SO ₃ M, -OSO ₃ M, -COOM, and P═O (OM) ₂ (wherein M is a hydrogen atom or an alkali metal such as lithium, potassium, or sodium). The polar functional group may be a side chain amine whose terminal group is -NR ¹ R ² or -NR ¹ R ² R ³ + X ^- , or a side chain amine represented by the formula NR ¹ R ² + X ^- wherein R ¹ , R ² and R ³ are hydrogen An atomic or hydrocarbon group, and X ^- is an ionic form of a halogen element such as fluorine, chlorine, bromine or iodine, or an inorganic ion or an organic ion). The polar functional groups include -OH, -SH, -CN, and epoxy groups. The polar functional group is preferably added to the binder in an amount of 10 ^-8 -10 ^-1 mol / g, more preferably 10 ^-2 -10 ^-6 mol / g.

The binder added to the magnetic layer is as described above, and may be used alone or in combination.

The above-mentioned magnetic powder and binder are dispersed in a solvent to produce a magnetic paint. Examples of the solvent include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone and the like, alcohol solvents such as methanol, ethanol, propanol, butanol, isopropanol and the like, , Ester solvents such as butyl acetate, propyl acetate, ethyl lactate and ethylene glycol acetate, ether solvents such as diethylene glycol dimethyether, 2-ethoxyethanol, tetrahydrofuran and dioxane, benzene, toluene, xylene And halogenated hydrocarbon solvents such as methylene chloride, ethylene chloride, carbon tetrachloride, chloroform, chlorobenzene, and the like.

A lubricant, an abrasive, a reinforcing agent, a dispersant, an antistatic agent, a corrosion inhibitor and the like suitable for a magnetic paint can be added. Dispersants, lubricants, antistatic agents and corrosion inhibitors are known materials and are not limited to specific chemicals.

Examples of the lubricant include graphite, molybdenum disulfide and tungsten disulfide, monocarboxylic acids having a C ₁₀ -C ₄₀ alkyl chain, electrolytes of these carboxylic acids, monoesters of these carboxylic acids and alcohols having 10 to 40 carbon atoms, Polyhydric esters of polyhydric alcohols and polyhydric esters of polyhydric alcohols, and amides, amines and alcohols having the above alkyl chains. Further, as the lubricant, there are silicone oil, parispin oil, fluoride of the above-mentioned compound, and a terpene compound and oligomer thereof.

Examples of the abrasive include aluminum oxide (alpha, beta and gamma), silicon carbide, chromium oxide, iron oxide, corundum, diamond, silicon fluoride, titanium carbide, titanium oxide (rutile or anatase), garnet, . The abrasive has a Mohs hardness of preferably 4 or more, more preferably 5 or more. The abrasive has a specific gravity of preferably 2-6, more preferably 3-5, and an average particle diameter of 0.5 μm or less, more preferably 0.3 μm or less. The apparent grain size was calculated by measuring from more than 100 samples randomly selected from the micrographs by electron microscopy. The abrasive is added to the magnetic powder in an amount of preferably 20 parts by weight, more preferably 10 parts by weight or less, per 100 parts by weight of the magnetic powder.

The antistatic agent is preferably carbon black, which is added to strengthen the application layer.

As the dispersing agent, there are various surfactants or coupling agents.

The reinforcing agent is polyisocyanate. Examples of the polyisocyanate include bifunctional isocyanates such as alkylene diisocyanates such as toluene diisocyanate, diphenylmethane diisocyanate and hexamethylene diisocyanate, xylene diisocyanate, naphthalene diisocyanate, and isophorone diisocyanate, and diisocyanates such as diisocyanate Copolymers, and reaction products with polyhydric alcohols. The reinforcing agent is added to the magnetic powder in an amount of preferably 5-80 parts by weight, more preferably 10-50 parts by weight or less, per 100 parts by weight of the magnetic powder.

To prepare magnetic paints, the materials are treated by methods such as kneading, blending and dispersing. Examples of the dispersing and kneading equipment include a roll mill, a ball mill, a sand mill, a stirrer, a kneader, an extruder, a homogenizer, and an ultrasonic disperser.

The magnetic paint thus prepared is suitably sprayed or applied onto a non-magnetic support, followed by drying and forming a magnetic layer thereon. Thereafter, the obtained tape is introduced into the calender to finish the surface flat.

When the magnetic layer is dried, the thickness is preferably 1-50 mu m, more preferably 1.0-30 mu m. The binder is preferably added to the magnetic powder in 1 part by weight per 1-10 parts by weight of the magnetic powder. If the binder is added at a ratio higher than the above value, the relative amount of the magnetic powder in the magnetic layer is decreased, so that the output of the obtained recording medium will be lower than normal. Moreover, if the obtained tape travels a magnetic head or another friction surface for several times, its magnetic layer will be deformed by molding, and the running property of the tape will be lowered. On the contrary, if the binder is added at a ratio lower than the above value, the obtained magnetic layer will be mechanically weakened and the running property of the tape will be lowered.

In manufacturing the coated magnetic layer, it is possible to improve the smoothness of the magnetic layer by introducing another non-magnetic layer (lower layer) between the magnetic layer and the non-magnetic support. A non-magnetic paint is prepared by dispersing a non-magnetic powder in a binder. When the magnetic layer is directly applied on the nonmagnetic support, if it is overly thinly applied, the roughness becomes similar to that of the lower nonmagnetic support and is slightly different from the complete smoothness. Conversely, when a nonmagnetic layer is introduced between the nonmagnetic support and the magnetic layer, a kind of cushion of a certain thickness is inserted between the nonmagnetic support and the magnetic layer so that the roughness of the lower nonmagnetic support is absorbed by the cushion and hardly appears on the surface of the magnetic layer. As a result, the surface of the magnetic layer is smoothed.

The binder used in the non-magnetic layer is the same binder as that in the magnetic layer.

Examples of the non-magnetic powder include non-magnetic iron oxides such as? -Fe ₂ O ₃ , gutite, gold-red-stone titanium oxide, anatase titanium oxide, tin oxide, tungsten oxide, silicon oxide, zinc oxide, Alumina, calcium sulfate, barium sulfate, molybdenum disulfide, magnesium carbonate, calcium carbonate, barium carbonate, strontium carbonate, barium titanate, and the like. The non-magnetic powder may be doped with an appropriate amount of impurity depending on a given purpose. The surface of the nonmagnetic layer can be treated with a compound such as Al, Si, Ti, Sn, Sb, or Zr to improve the dispersing ability, electrical conductivity and coloring property. The non-magnetic powder may be used alone or in combination. A specific surface area of the nonmagnetic powder is preferably 30-80 m ² / g, more preferably 40-70m ² / g.

In addition to the non-magnetic powder, the non-magnetic layer may include carbon black such as a rubber reinforcing agent, heat cracked carbon, black pigment, acetylene black and the like. The specific surface area of the carbon black particles is preferably 100-400 m ² / g, and the degree of DBP oil absorption is 20-200 ml / 100 g.

The reason that the specific surface area of the carbon black particles and other nonmagnetic particles are determined as described above is closely related to the smoothness of the resultant nonmagnetic layer and the magnetic layer. When carbon black or other non-magnetic powder contains particles having a particle size within the above range, the carbon black is composed of the fine particles. That is, the nonmagnetic layer produced therefrom has a smooth surface, whereby the upper magnetic layer can have a smooth surface. As a result, since the control noise and the spacing loss are effectively suppressed, the degree of electromagnetic conversion is increased by the magnetic recording medium from which the surface roughness of the magnetic layer is removed. On the other hand, when the magnetic recording medium has a magnetic layer produced by vapor deposition, In the case of having a magnetic layer made of a magnetic metal thin film, the magnetic metal thin film can be produced by depositing a ferromagnetic metal material on the surface of a nonmagnetic support by electrolytic deposition, sputtering or vacuum deposition. The magnetic metal thin film may be made of a metal such as Fe, Co or Ni suitable for the in-plane recording or a copolymer of Co-Ni, Co-Pt, Co-Pt-Ni, Fe-Co, Fe- Or by aligning a copolymer of Co-Cr suitable for perpendicular recording.

The in-plane recording magnetic metal thin film is formed by forming a substrate made of a nonmagnetic element having a low melting point such as Bi, Sb, Pb, Sn, Ga, In, Ge, Si or Ti on a nonmagnetic support and forming a ferromagnetic metal Or by sputtering to form a magnetic metal thin film on the substrate. When the ferromagnetic metal is deposited from above the substrate, the nonmagnetic element having a low melting point is dispersed in the magnetic metal thin film formed as described above, and the orientation property of the magnetic metal thin film is solved to obtain the isotropy of the in-plane orientation, .

The carbon film is formed on the surface of the magnetic metal thin film. The carbon film may have any internal structure. Graphite, diamond, or amorphous. The carbon film can be generally formed by sputtering or by any other method including CVD. The thickness of the carbon film is preferably 2-100 nm, particularly preferably 5-30 nm.

The magnetic recording medium to which the present invention is applied may have a sublayer formed on the opposite side of the surface on which the magnetic layer is formed as described above. As described above, the undercoating layer is formed by mixing the carbon powder that imparts electrical conductivity to the binder of the magnetic paint, and the inorganic pigment added to control the surface roughness of the obtained coating layer, and the undercoat layer is formed, And to prevent the transfer of components to other elements in contact with each other, as well as to improve the running property of the obtained recording medium.

Examples of the powder to be added to the undercoat layer include powdery materials such as 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 , Hydrated iron oxide powder, magnesium silicate powder, calcium carbonate powder, aluminum silicate powder, barium sulfate powder and clay powder.

The average particle size of the powder is preferably 0.001 - 1.0 탆. If the particle diameter is less than the above value, the surface of the primer layer will be rough without being easily dispersed in the primer. On the other hand, when the particle diameter exceeds the above value, hard and large irregularities are formed on the surface of the underlayer, and when the magnetic tape having such irregularities is wound on the reel, the irregularities are transferred to the upper tape portion. The powder is added to the resin binder in an amount of preferably 25 to 150 parts by weight per 100 parts of the resin binder. If the powder is added below this ratio, the surface smoothness of the undercoat layer is insufficient, and if the powder is added in excess of the above ratio, the mechanical strength of the undercoat layer is insufficient.

In carrying out the present invention, it is possible to prevent the adhesion of the combustible to the magnetic head. The magnetic head to which the present invention is applied may have any configuration as long as it is in the recording / reproducing operation or in contact with the running tape every time it is operated or stopped at the end of the recording / reproducing start. Specifically, as a magnetic head, there are an ordinary ferrite head metal-in-gap (MIG) type head, a lamination type head, an induction type head, and a head based on a magnetoresistive effect (MR). The head can be made of a known material.

Examples of the cleaning tape of the present invention are as follows.

The cleaning tape of the present invention is prepared by incorporating a compound having a pyridine skeleton and two or more ligand sites or a diketone compound (ligand) in a nonmagnetic support.

As the compound or diketone compound (ligand) having a pyridine skeleton and two or more ligand sites used therein, there is the above-mentioned ligand for the anti-sticking agent of the magnetic recording medium. Specifically, there are pyridine derivatives of Formula 31, quinoline derivatives of Formula 32, non-pyridine derivatives of Formula 33, and phenanthroline derivatives of Formula 34. In this case also, the ligand can accommodate the substituents described above. The ligands may be used alone or in combination.

As the diketone compound (ligand) used herein, there is the above-mentioned ligand as the antiadhesive agent material of the magnetic recording medium of the present invention. Specifically, there are 1,3-diketones of the formula (48) and 1,5-diketones of the formula (49). In this case also, the ligand can accommodate the various substituents described above. Two adjacent pairs of the compounds of formula (49) may form a heterocyclic ring between the compounds of formula (52). The ligands may be used alone or in combination.

The ligand has the property of forming a complex in the presence of a metal atom. That is, when the cleaning tape to which these ligands are administered passes through the magnetic head, the ligand forms a complex with the metal oxide formed on the surface of the magnetic head, and this complex is easily removed from the surface of the magnetic head.

As the support on which the ligand is held, there is a polymer film made of polyethylene terephthalate, polyethylene naphthalate, polyphenylene sulfide, polyamide, polyimide and the like. The thickness of the polymer film is preferably 1.0 to 200 占 퐉, more preferably 2.0 to 100 占 퐉.

The support may be made of a nonwoven fabric prepared by bonding fibers made of these polymers to each other.

The shape of the support may be appropriately selected in accordance with the application, and the cleaning tape for cleaning the magnetic head while contacting the magnetic tape is in tape form. A cleaning tape for cleaning a magnetic head for a floppy disk includes a support on a disk.

The method of holding the ligand on the support comprises the steps of preparing a cleaning coating by dissolving the ligand in a solvent, and coating the cleaning coating on the support.

When the support is a polymer film, the cleaning coating is applied to the surface of the polymer film and is viewed as a thin film. When the support is a single nonwoven fabric, the cleaning paint is absorbed by the nonwoven fabric and stored in the nonwoven fabric.

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 , An ester solvent such as butyl acetate, an aromatic hydrocarbon solvent such as benzene, toluene, and xylene, and water.

The cleaning layer may be prepared by first applying a layer comprising a binder and then applying a cleaning paint over the layer. A powder such as a carbon bladder may be added to the layer to prevent the generation of static electricity and to enhance the strength of the layer.

When a cleaning coating is used, it is preferable to add 10 mg-10 g of ligand per m ^{2 of the} support surface. If the ligand is added below this value, the combustible attached to the magnetic surface will not be effectively removed. Conversely, if added below this value, the ligand itself will adhere onto the magnetic head to inhibit the smooth running of the tape.

The cleaning paint may be held on the support before use or immediately prior to use.

Binders can also be added to the cleaning coating to allow the ligand to bind to the support by the binder. In this case, the ligand is retained by the binder layer as it is added into the binder. The binder layer may also include a powder such as carbon black to prevent static buildup and increase the strength of the layer.

Examples of the binder include vinyl chloride, vinyl acetate, vinyl propionate, vinyl alcohol, maleic acid, ester acrylate, methacrylate, ester methacrylate, vinylidene chloride, acrylonitrile, methacrylonitrile, styrene, , Butadiene, ethylene, vinyl acetal, vinyl butyral, vinyl ether, vinyl pyrrolidone, and the like. Further, cellulose such as nitrocellulose, cellulose acetate and the like, and polyurethane resin, phenol resin, epoxy resin, phenoxy resin, urea resin, melamine resin, alkyd resin, polyester resin, polyamide resin and silicone resin.

The binder is preferably added in an amount of 10 parts by weight, more preferably 5 parts by weight or less, per 1 part by weight of the ligand. The dry thickness is preferably 50 mu m or less, more preferably 30 mu m or less.

Example

Preferred embodiments according to the present invention are described below, but the present invention is not limited to these embodiments.

Review of magnetic recording media

First, in Experiments 1 to 6, the effect of holding a compound (ligand) having a pyridine skeleton and two or more ligand sites on a magnetic recording medium was studied.

Experiment 1

The inventors of the present invention carried out recording and reproduction using a magnetic tape by making a coating type magnetic layer hold an anti-adhesion agent containing a compound (ligand) having a pyridine skeleton and two or more ligand sites, and using magnetic tape.

Specifically, 100 parts by weight of acicular ferromagnetic iron powder (specific surface area: 53.9 cm ² / g, coercive force: 1580 Oe, saturation magnetization: 120 emu / g), 10 parts by weight of a thermoplastic polyurethane resin (average molecular weight: 20,000) Alumina (average particle diameter 200 nm) 5 parts by weight, olive oil 3 parts by weight, a mixed solvent (methyl ethyl ketone / methyl isobutyl ketone / methyl isobutyl ketone / Toluene = 2: 1: 1).

These components were mixed in a ball mill for 48 hours, 3.5 parts of a reinforcing agent consisting of polyisocyanate were added, and the resultant was mixed for a further 30 minutes.

The magnetic paint thus obtained was applied to a polyethylene terephthalate film having a thickness of 7 탆 to obtain a film having a dry thickness of 2 탆. Thereafter, the film was dried, calendered and allowed to stand in an oven at 60 DEG C for 20 hours to cure to form a magnetic film.

The sheet was cut into a piece having a width of 8 mm, and the following anti-adhesion agent was applied to the surface of the magnetic layer by a dipping method to prepare a magnetic tape.

The antifouling agent used here was prepared by dissolving a compound (ligand) having a pyridine skeleton and two or more ligand sites in toluene. Ligands include compounds (A-1 to A-9) of the formula (64) in which substituents X and R ⁴ are as described in Table 1, and all other substituents are hydrogen atoms. In the compounds A-1 to A-3, the substituent X is as shown in the following formula (65-67). (B-1 to B-8), R ¹¹ , R ¹³ and R ^{16 in} which substituents Y and R are as described in Table 2 and all other substituents are hydrogen atoms are shown in Table 3, (C-1 to C-2) wherein R ¹⁹ , R ²¹ and R ²⁴ are as defined in Table 4 and all other substituents are hydrogen atoms, (D-1 to D-2). The ligands include the same compounds E-1 and E-2 as the compounds of the general formula (68) except for the substituent X of the triazine, and the substituent R ¹⁰ of the heterocyclic aromatic compound There are the same compounds F-1 and F-4 of the general formulas (73) to (76) as the compound of the general formula (68). The ligands also include compounds F-5 and F-6 of the formulas 77 and 78 which are identical to compounds of formulas 73 and 76, except that substituents R ¹⁰ of the heterocyclic aromatic compound are included. Substituents R ⁸⁰ -R ⁹⁹ in formulas (73), (74) and (77) are all hydrogen atoms.

In the formulas, R ¹ to R ^{4 each} represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group, Wherein two adjacent pairs of groups may together form an aromatic ring and X is selected from the group consisting of a hydroxyl, a Schiff base, an ester, a carboxylic acid, an alcohol, an amine, an amide, an imide and a heterocyclic aromatic containing polar group Is selected.

compound X R ¹ A-1 (65) H A-2 66 H A-3 (67) H A-4 CH ₂ NH ₂ H A-5 COOCH ₃ H A-6 COOC ₂ H ₅ H A-7 CONHC ₂ H ₅ H A-8 OH H A-9 OH CH ₃

-CH ₂ CH ₂ NHCH ₂ CH ₂ OH

Wherein R ⁵ to R ¹⁰ are each a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group, and an alkyl group, And two adjacent pairs of groups may together form an aromatic ring, and Y is OH, SH or NH ₂ .

compound Y R ⁵ B-1 NH ₂ H B-2 SH H B-3 OH nC ₃ H ₇ B-4 OH F B-5 OH Cl B-6 OH NH ₂ B-7 OH NO ₂ B-8 OH SO ₃ H

In the formulas, R ¹ to R ¹⁸ represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group, And two adjacent pairs of the groups may form an aromatic ring together.

compound R ¹¹ R ¹³ R ¹⁶ C-1 CH ₃ H H C-2 CH ₃ CH ₃ H C-3 H CH ₃ H C-4 H CH ₃ CH ₃ C-5 H Aryl group H C-6 H NO ₂ H C-7 H NO ₂ NO ₂ C-8 H SO ₃ Na H C-9 H SO ₃ Na SO ₃ Na C-10 H NH ₂ H C-11 H NH ₂ NH ₂ C-12 H CH ₃ (CH _{2) 6} H C-13 H CH ₃ (CH _{2) 6} CH ₃ (CH _{2) 6} C-14 H CH ₃ (CH _{2) 8} H C-15 H CH ₃ (CH _{2) 8} CH ₃ (CH _{2) 8} C-16 H CH ₃ (CH _{2) 10} H C-17 H CH ₃ (CH _{2) 10} CH ₃ (CH _{2) 10} C-18 H CH ₃ (CH _{2) 12} H C-19 H CH ₃ (CH _{2) 12} CH ₃ (CH _{2) 12} C-20 H CH ₃ (CH _{2) 14} H C-21 H CH ₃ (CH _{2) 14} CH ₃ (CH _{2) 14} C-22 H CH ₃ (CH _{2) 16} H C-23 H CH ₃ (CH _{2) 16} CH ₃ (CH _{2) 16}

Wherein R ¹⁹ to R ^{26 each} represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group, an aryl group and a heterocyclic aromatic group And two adjacent pairs of the groups may form an aromatic ring together.

compound R ¹⁹ R ²¹ R ²⁴ D-1 CH ₃ H H D-2 CH ₃ CH ₃ H D-3 H CH ₃ H D-4 H Aryl group H D-5 H NO ₂ H D-6 H NO ₂ NO ₂ D-7 H SO ₃ Na H D-8 H SO ₃ Na SO ₃ Na D-9 H NH ₂ H D-10 H NH ₂ NH ₂ D-11 H CH ₃ (CH _{2) 6} H D-12 H CH ₃ (CH _{2) 6} CH ₃ (CH _{2) 6} D-13 H CH ₃ (CH _{2) 8} H D-14 H CH ₃ (CH _{2) 8} CH ₃ (CH _{2) 8} D-15 H CH ₃ (CH _{2) 10} H D-16 H CH ₃ (CH _{2) 10} CH ₃ (CH _{2) 10} D-17 H CH ₃ (CH _{2) 12} H D-18 H CH ₃ (CH _{2) 12} CH ₃ (CH _{2) 12} D-19 H CH ₃ (CH _{2) 14} H D-20 H CH ₃ (CH _{2) 14} CH ₃ (CH _{2) 14} D-21 H CH ₃ (CH _{2) 16} H D-22 H CH ₃ (CH _{2) 16} CH ₃ (CH _{2) 16}

R ⁸⁰ to R ⁸⁵ are selected from a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and alkyl groups substituted by the aforementioned groups, an aryl group and a heterocyclic aromatic group And two adjacent pairs of the groups may together form an aromatic ring.

R ⁸⁶ to R ⁹¹ are selected from a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group substituted by the above-mentioned group, an aryl group and a heterocyclic aromatic group And two adjacent pairs of the groups may together form an aromatic ring.

R ⁹² to R ⁹⁹ are selected from a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group, an aryl group and a heterocyclic aromatic group substituted by the above- And two adjacent pairs of the groups may together form an aromatic ring.

Subsequently, a magnetic tape to which the ligand was applied was placed in a cassette shell to prepare a cartridge. Then, the following measurement test was carried out. For comparison, a similar measurement test was performed on a magnetic tape on which the above-described anti-adhesion agent was not applied to the surface.

More specifically, the magnetic head shown in FIG. 1, that is, a pair of magnetic core ends 1 and 2 is formed of a ferromagnetic oxide such as single crystal ferrite and has a high magnetic flux density Bs having a high saturation magnetic flux density Bs such as FeAlSi- The metal thin film 3 is deposited on the surfaces of the two ends facing each other at regular intervals and the metal thin film is arranged obliquely in parallel so that the ferromagnetic metal thin film 3 faces each other A video tape recorder having a magnetic head was manufactured.

Using such a videotape recorder, a signal was recorded on the test magnetic tape for 1 minute and the signal was reproduced therefrom. During this, the output from the tape was measured. Thereafter, a signal of the tape was recorded for 20 minutes, and the regenerating mechanism was repeated ten times and the output was measured. The final test output was compared to the initial output to calculate the final output drop (level down) based on the initial output.

After the recording and reproducing mechanism of the tape was performed as described above, the tape was removed from the video tape recorder and the friction surface, that is, the surface on which the magnetic head traveled, was observed with an electron microscope. As a result of electron microscopic observation, on the friction surface of the magnetic tape, X was marked when the combustible adhered to the ferromagnetic metal thin film (3). Electron microscope observation indicated O when the combustible does not appear in the ferromagnetic metal film (3).

Level down and electron microscopy observations are described in the following Tables 5-8, along with the ligand compounds used to identify the test strip. The corresponding results from the tapes that do not contain an antifouling agent are also listed.

compound Level Down (dB) Presence or absence of combustible materials A-1 1.0 O A-2 1.5 O A-3 2.0 O A-4 1.0 O A-5 1.0 O A-6 1.5 O A-7 1.0 O A-8 1.5 O A-9 1.5 O B-1 1.0 O B-2 1.5 O B-3 1.5 O B-4 1.0 O B-5 1.0 O B-6 1.5 O B-7 1.0 O B-8 2.5 O

compound Level Down (dB) Presence or absence of combustible materials C-1 0.5 O C-2 1.0 O C-3 0.5 O C-4 1.5 O C-5 1.0 O C-6 1.5 O C-7 2.0 O C-8 1.5 O C-9 1.5 O C-10 0.5 O C-11 1.0 O C-12 1.0 O C-13 1.5 O C-14 0.5 O C-15 0.5 O C-16 1.0 O C-17 1.0 O C-18 1.0 O C-19 1.5 O C-20 1.0 O C-21 1.5 O C-22 1.0 O C-23 1.0 O

compound Level Down (dB) Presence or absence of combustible materials D-1 0.5 O D-2 1.0 O D-3 0.5 O D-4 1.5 O D-5 1.0 O D-6 1.5 O D-7 2.0 O D-8 1.5 O D-9 1.5 O D-10 0.5 O D-11 1.0 O D-12 1.0 O D-13 1.5 O D-14 0.5 O D-15 0.5 O D-16 1.0 O D-17 1.0 O D-18 1.0 O D-19 1.5 O D-20 1.0 O D-21 1.5 O D-22 1.0 O

compound Level Down (dB) Presence or absence of combustible materials E-1 1.5 O E-2 1.5 O F-1 1.5 O F-2 1.0 O F-3 1.0 O F-4 1.0 O F-5 1.0 O F-6 1.0 O Not added 10 X

As shown in Figs. 5-8, in the magnetic tape on which the anti-adherence agent is not applied on the magnetic layer, a large level down occurs at the time of output, and the combustible remains on the running magnetic head. On the contrary, the compounds A-1 to A-9, B-1 to B-8, C-1 to C-23, D-1 to D-22, E-1 to E- The magnetic tape having the ligand-containing anti-adhesion agent of 6 has less level-down, and no combustible remains on the magnetic head.

Fig. 2 is a schematic diagram of a magnetic head based on an electron microscope photograph, which is used for recording and reproduction on a magnetic tape having an anti-adhesion agent containing a ligand to be applied. 3 is a schematic view of a magnetic head based on an electron micrograph, which is used for recording and reproducing on a magnetic tape having no antistatic agent applied on the magnetic layer. Fig. 3 shows that the combustible 4 is generated in the ferromagnetic metal film 3, while Fig. 2 shows that the combustible 4 is not generated at all as if it was not recorded and reproduced.

From the above results, it can be seen that the use of a tape having an antifouling agent containing a ligand, that is, a compound having a pyridine skeleton and at least one ligand site, can prevent generation of combustion products on the running magnetic head.

Experiment 2

In this experiment, a magnetic tape was prepared by applying an anti-adhesion agent containing a carboxylic acid together with the ligand to a so-called coated magnetic layer.

Specifically, 6 parts by weight of a carboxylic acid (oleic acid or myristic acid) and 5 parts by weight of a ligand were further added to the same composition as that used in Experiment 1. The obtained composition was mixed, the reinforcing agent was added, and mixed in the same manner as in Experiment 1.

As in Experiment 1, the magnetic paint thus obtained was applied to a polyethylene terephthalate film, followed by drying and calendering. Then, the sheet was heat-treated and cured to form a magnetic layer. The sheet was cut into pieces to prepare a finished magnetic tape. In this experiment, an anti-adhesion agent was added to the magnetic layer and was not applied to the surface of the magnetic layer.

An anti-adhesion agent added to the magnetic layer was prepared as follows.

Compounds A-1 to A-9: Substituent X of formula 64 was varied in various ways.

Compound A-10: COOH (X = COOH) was selected with substituent X of formula 64 and H (R ⁴ = H) was selected with R ¹ -R ⁴ .

Compounds B-1 to B-8: Substituent X of formula 68 was varied in various ways.

Compound B-9: selected the CH ₃ OH as the substituent Y in the formula 68, with R ^7.

Compound B-10: selected the CH ₃ OH as the substituent Y in the formula 68, with R ⁵ -R ^10.

The substituents R ¹¹ , R ¹³ , R ¹⁶ and R ¹⁸ of the compounds of the formulas C-24 to C-48 were selected as hydrogen substituents as shown in Table 9.

Compounds D-23 to D-47: Substituents R ¹⁹ , R ²¹ , R ²⁴ and R ²⁶ of formula 70 were selected as shown in Table 10.

Compounds of compounds E-1 to E-2: The compounds of formulas 71 and 72 were selected.

Compounds of compounds F-1 to F-4: The compounds of formulas 73 to 76 were selected.

Compounds of compounds F-5 to F-6: The compounds of formulas 77 and 78 were selected.

compound R ¹¹ R ¹³ R ¹⁶ R ¹⁸ C-24 H H H H C-25 CH ₃ H H CH ₃ C-26 H CH ₃ CH ₃ H C-27 CH ₃ CH ₃ CH ₃ CH ₃ C-28 H Aryl group Aryl group H C-29 CH ₃ Aryl group Aryl group CH ₃ C-30 H Aryl group H H C-31 H CH ₃ H H C-32 CH ₃ CH ₃ H CH ₃ C-33 H NO ₂ H H C-34 CH ₃ NO ₂ H CH ₃ C-35 H NO ₂ NO ₂ H C-36 CH ₃ NO ₂ NO ₂ CH ₃ C-37 H CH ₃ (CH _{2) 6} CH ₃ (CH _{2) 6} H C-38 H CH ₃ (CH _{2) 6} H H C-39 CH ₃ CH ₃ (CH _{2) 6} CH ₃ (CH _{2) 6} CH ₃ C-40 CH ₃ CH ₃ (CH _{2) 6} H CH ₃ C-41 H SO ₃ Na H H C-42 H SO ₃ Na SO ₃ Na H C-43 CH ₃ SO ₃ Na H CH ₃ C-44 CH ₃ SO ₃ Na SO ₃ Na CH ₃ C-45 H CH ₃ (CH _{2) 14} CH ₃ (CH _{2) 14} H C-46 H CH ₃ (CH _{2) 14} H H C-47 CH ₃ CH ₃ (CH _{2) 14} CH ₃ (CH _{2) 14} CH ₃ C-48 CH ₃ CH ₃ (CH _{2) 14} H CH ₃

compound R ¹⁹ R ²¹ R ²⁴ R ²⁶ C-23 H H H H C-24 CH ₃ H H CH ₃ C-25 H CH ₃ CH ₃ H C-26 CH ₃ CH ₃ CH ₃ CH ₃ C-27 H Aryl group Aryl group H C-28 CH ₃ Aryl group Aryl group CH ₃ C-29 H Aryl group H H C-30 H CH ₃ H H C-31 CH ₃ CH ₃ H CH ₃ C-32 H NO ₂ H H C-33 CH ₃ NO ₂ H CH ₃ C-34 H NO ₂ NO ₂ H C-35 CH ₃ NO ₂ NO ₂ CH ₃ C-36 H CH ₃ (CH _{2) 6} CH ₃ (CH _{2) 6} H C-37 H CH ₃ (CH _{2) 6} H H C-38 CH ₃ CH ₃ (CH _{2) 6} CH ₃ (CH _{2) 6} CH ₃ C-39 CH ₃ CH ₃ (CH _{2) 6} H CH ₃ C-40 H SO ₃ Na H H C-41 H SO ₃ Na SO ₃ Na H C-42 CH ₃ SO ₃ Na H CH ₃ C-43 CH ₃ SO ₃ Na SO ₃ Na CH ₃ C-44 H CH ₃ (CH _{2) 14} CH ₃ (CH _{2) 14} H C-45 H CH ₃ (CH _{2) 14} H H C-46 CH ₃ CH ₃ (CH _{2) 14} CH ₃ (CH _{2) 14} CH ₃ C-47 CH ₃ CH ₃ (CH _{2) 14} H CH ₃

A magnetic tape in which the ligand and oleic acid were combined and added to the magnetic layer was prepared. The ligand and myristic acid were combined to produce another kind of magnetic tape added to the magnetic layer. After the tape was introduced into the cassette shell to make it into a cartridge, the following measurement test was carried out. A comparative tape to which only oleic acid or myristic acid was added to the magnetic layer was prepared and the same measurement test was conducted.

Measurement tests were carried out in the same manner as in Experiment 1. The evaluation results are shown in Table 11-17 together with the combination of the carboxylic acid and the ligand added to the magnetic layer. Table 17 shows magnetic tape evaluation results in which only oleic acid or myristic acid was added to the magnetic layer.

compound Carboxylic acid Level Down (dB) Presence or absence of combustible materials A-1 Oleic acid 1.0 O A-1 Myristic acid 0.5 O A-2 Oleic acid 1.0 O A-2 Myristic acid 0.5 O A-3 Oleic acid 1.0 O A-3 Myristic acid 1.0 O A-4 Oleic acid 1.0 O A-4 Myristic acid 0.5 O A-5 Oleic acid 0.5 O A-5 Myristic acid 0.5 O A-6 Oleic acid 1.0 O A-6 Myristic acid 0.5 O A-7 Oleic acid 0.5 O A-7 Myristic acid 0.5 O A-8 Oleic acid 0.5 O A-8 Myristic acid 0.5 O A-9 Oleic acid 1.0 O A-9 Myristic acid 1.0 O A-10 Oleic acid 0.5 O A-10 Myristic acid 0.5 O

compound Carboxylic acid Level Down (dB) Presence or absence of combustible materials B-1 Oleic acid 1.0 O B-1 Myristic acid 0.5 O B-2 Oleic acid 1.0 O B-2 Myristic acid 0.5 O B-3 Oleic acid 1.0 O B-3 Myristic acid 0.5 O B-4 Oleic acid 0.5 O B-4 Myristic acid 0.5 O B-5 Oleic acid 0.5 O B-5 Myristic acid 0.5 O B-6 Oleic acid 1.0 O B-6 Myristic acid 0.5 O B-7 Oleic acid 0.5 O B-7 Myristic acid 0.5 O B-8 Oleic acid 0.5 O B-8 Myristic acid 0.5 O B-9 Oleic acid 1.0 O B-9 Myristic acid 1.0 O B-10 Oleic acid 1.0 O B-10 Myristic acid 1.0 O

compound Carboxylic acid Level Down (dB) Presence or absence of combustible materials C-24 Oleic acid 1.0 O C-24 Myristic acid 0.5 O C-25 Oleic acid 1.0 O C-25 Myristic acid 0.5 O C-26 Oleic acid 1.0 O C-26 Myristic acid 1.0 O C-27 Oleic acid 1.0 O C-27 Myristic acid 0.5 O C-28 Oleic acid 0.5 O C-28 Myristic acid 0.5 O C-29 Oleic acid 0.5 O C-29 Myristic acid 0.5 O C-30 Oleic acid 1.0 O C-30 Myristic acid 0.5 O C-31 Oleic acid 0.5 O C-31 Myristic acid 0.5 O C-32 Oleic acid 0.5 O C-32 Myristic acid 0.5 O C-33 Oleic acid 1.0 O C-33 Myristic acid 1.0 O C-34 Oleic acid 1.0 O C-34 Myristic acid 1.0 O C-35 Oleic acid 1.5 O C-35 Myristic acid 1.0 O C-36 Oleic acid 1.0 O C-36 Myristic acid 0.5 O

compound Carboxylic acid Level Down (dB) Presence or absence of combustible materials C-37 Oleic acid 1.0 O C-37 Myristic acid 0.5 O C-38 Oleic acid 0.5 O C-38 Myristic acid 0.5 O C-39 Oleic acid 0.5 O C-39 Myristic acid 0.5 O C-40 Oleic acid 1.0 O C-40 Myristic acid 0.5 O C-41 Oleic acid 1.5 O C-41 Myristic acid 1.0 O C-42 Oleic acid 1.0 O C-42 Myristic acid 0.5 O C-43 Oleic acid 1.0 O C-43 Myristic acid 0.5 O C-44 Oleic acid 0.5 O C-44 Myristic acid 0.5 O C-45 Oleic acid 1.0 O C-45 Myristic acid 0.5 O C-46 Oleic acid 1.0 O C-46 Myristic acid 0.5 O C-47 Oleic acid 1.0 O C-47 Myristic acid 1.0 O C-48 Oleic acid 1.0 O C-48 Myristic acid 1.0 O

compound Carboxylic acid Level Down (dB) Presence or absence of combustible materials D-23 Oleic acid 1.0 O D-23 Myristic acid 0.5 O D-24 Oleic acid 1.0 O D-24 Myristic acid 0.5 O D-25 Oleic acid 1.0 O D-25 Myristic acid 1.0 O D-26 Oleic acid 1.0 O D-26 Myristic acid 0.5 O D-27 Oleic acid 0.5 O D-27 Myristic acid 0.5 O D-28 Oleic acid 0.5 O D-28 Myristic acid 0.5 O D-29 Oleic acid 1.0 O D-29 Myristic acid 0.5 O D-30 Oleic acid 0.5 O D-30 Myristic acid 0.5 O D-31 Oleic acid 0.5 O D-31 Myristic acid 0.5 O D-32 Oleic acid 1.0 O D-32 Myristic acid 1.0 O D-33 Oleic acid 1.0 O D-33 Myristic acid 1.0 O D-34 Oleic acid 1.5 O D-34 Myristic acid 1.0 O D-35 Oleic acid 1.0 O D-35 Myristic acid 0.5 O

compound Carboxylic acid Level Down (dB) Presence or absence of combustible materials D-36 Oleic acid 1.0 O D-36 Myristic acid 0.5 O D-37 Oleic acid 0.5 O D-37 Myristic acid 0.5 O D-38 Oleic acid 0.5 O D-38 Myristic acid 0.5 O D-39 Oleic acid 1.0 O D-39 Myristic acid 0.5 O D-40 Oleic acid 1.5 O D-40 Myristic acid 1.0 O D-41 Oleic acid 1.0 O D-41 Myristic acid 0.5 O D-42 Oleic acid 1.0 O D-42 Myristic acid 0.5 O D-43 Oleic acid 0.5 O D-43 Myristic acid 0.5 O D-44 Oleic acid 1.0 O D-44 Myristic acid 0.5 O D-45 Oleic acid 1.0 O D-45 Myristic acid 0.5 O D-46 Oleic acid 1.0 O D-46 Myristic acid 1.0 O D-47 Oleic acid 1.0 O D-47 Myristic acid 1.0 O

compound Carboxylic acid Level Down (dB) Presence or absence of combustible materials E-1 Oleic acid 1.0 O E-1 Myristic acid 0.5 O E-2 Oleic acid 1.0 O E-2 Myristic acid 0.5 O F-1 Oleic acid 1.0 O F-1 Myristic acid 1.0 O F-2 Oleic acid 1.0 O F-2 Myristic acid 0.5 O F-3 Oleic acid 0.5 O F-3 Myristic acid 1.0 O F-4 Oleic acid 0.5 O F-4 Myristic acid 1.0 O F-5 Oleic acid 0.5 O F-5 Myristic acid 0.5 O F-6 Oleic acid 0.5 O F-6 Myristic acid 0.5 O E-1 Not added 4.0 X Not added Oleic acid 10 X Not added Myristic acid 10 X

As shown in Table 11-17, a magnetic tape to which only a carboxylic acid is added to the magnetic layer generates a large level-down at the time of output, and a combustible is generated on the surface of the magnetic head. Conversely, a magnetic tape having a magnetic layer to which a compound ligand and a carboxylic acid combination is added does not show level-down, and does not accumulate combustibles on the magnetic head.

A small amount of combustible material was generated on the surface of the magnetic head by a magnetic tape to which only a ligand was added to the magnetic layer and no carboxylic acid was added. The magnetic tape to which only the ligand is added and the carboxylic acid is not added is also leveled down to about -4 dB. From this, it can be seen that the addition of the carboxylic acid to the ligand enhances the effect of preventing the ligand from adhering the combustible on the magnetic head. This may be because the carboxylic acid is attached to the magnetic particles to prevent the ligand from attaching to the magnetic particles.

A magnetic head used for recording and reproduction on a magnetic tape to which a combination of a ligand and a carboxylic acid was added was subjected to electron microscopic processing and visualized on the basis of a microscope photograph to obtain an image similar to Fig. A magnetic head used for recording and reproduction on a magnetic tape to which only a carboxylic acid was added was subjected to electron microscopic processing and visualized on the basis of a microscope photograph to obtain an image similar to Fig.

From the above results it can be seen that tapes to which a combination of a ligand, i.e. a compound having a pyridine skeleton and at least one ligand moiety, and a carboxylic acid have been added, produce combustion on the magnetic head traveling relative to a tape to which the ligand or carboxylic acid has been added It can be seen that it is effectively prevented.

Further, as a result of conducting an experiment on a tape coated with a carboxylic acid in the magnetic layer, it was found that such a treatment did not significantly affect the level-down improvement at the time of output. Therefore, it is more preferable to add a carboxylic acid in the magnetic layer than to coat the carboxylic acid on the magnetic layer.

Experiment 3

In this experiment, an organic acid salt-containing antistatic agent for the ligand was applied to the coated magnetic layer to prepare a magnetic tape.

Specifically, 3 parts by weight of a lubricant (oleic acid) and 3 parts by weight of an organic salt of a ligand were further added to the same composition used in Experiment 1. These were mixed, the reinforcing agent was added, and further mixed in the same manner as in Experiment 1.

As in Experiment 1, the obtained magnetic paint was applied to a polyethylene terephthalate film, followed by drying and calendering. Then, the sheet was heat-treated and cured to prepare a magnetic layer. The sheet was cut into pieces to prepare a finished magnetic tape. In this experiment, an anti-adhesion agent was added to the magnetic layer and was not applied to the surface of the magnetic layer.

The organic acid salt of the ligand to be added to the magnetic layer was prepared as follows.

Compounds C-101 to C-107: were selected hydrogen in formula 69 the substituents R ^11, R ^13, R ¹⁶ and R ^18, and selection of an organic acid as shown in Table 18, and the substituents R ^12, R ^14, R ¹⁵ and R ¹⁷ of the .

Compounds D-101 to D-108: Substituents R ¹⁹ , R ²¹ , R ²⁴ and R ²⁶ of formula 70 and organic acids were selected as shown in Table 19 and hydrogen was selected as substituents R ²⁰ , R ²² , R ²³ and R ²⁵ .

Wherein R ¹¹ to R ¹⁸ are a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group substituted with the above- And two adjacent pairs of the groups may form an aromatic ring together and R ^* is a group selected from a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group or a sulfonate group An aryl group substituted with an alkyl group, a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group or a sulfonate group, and an alkyl group coupled with a heterocyclic aromatic group.

compound R ¹¹ R ¹³ R ¹⁶ R ¹⁸ Organic acid C-101 H H H H Acetic acid C-102 H H H H Myristic acid C-103 H H H H Oleic acid C-104 H H H H Stearic acid C-105 CH ₃ H H CH ₃ Oleic acid C-106 H CH ₃ CH ₃ H Oleic acid C-107 CH ₃ CH ₃ CH ₃ CH ₃ Myristic acid Not added - - - - - C-108 H H H H - C-109 CH ₃ H H CH ₃ - C-110 H CH ₃ CH ₃ H - C-111 CH ₃ CH ₃ CH ₃ CH ₃ -

Wherein R ¹⁹ to R ^{26 each} represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group, an aryl group and a heterocyclic aromatic group And two adjacent pairs of the groups may form an aromatic ring together and R ^* is a group selected from a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group or a sulfonate group An aryl group substituted with an alkyl group, a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group or a sulfonate group, and an alkyl group coupled with a heterocyclic aromatic group.

compound R ¹⁹ R ²¹ R ²⁴ R ²⁶ Organic acid C-101 H H H H Acetic acid C-102 H H H H Myristic acid C-103 H H H H Stearic acid C-104 H H H H Oleic acid C-105 CH ₃ H H CH ₃ Oleic acid C-106 H C ₆ H ₅ C ₆ H ₅ H Oleic acid C-107 H CH ₃ CH ₃ H Myristic acid C-108 CH ₃ C ₆ H ₅ C ₆ H ₅ CH ₃ - Not added - - - - - C-109 H H H H - C-110 CH ₃ H H CH ₃ - C-111 H C ₆ H ₅ C ₆ H ₅ H - C-112 H CH ₃ CH ₃ H - C-113 CH ₃ C ₆ H ₅ C ₆ H ₅ CH ₃ -

A tape to which the organic acid salt of the ligand was added to the magnetic layer was introduced into the cassette shell to make a cartridge, and the level down at the time of output was measured as in Experiment 1. We set the video tape recorder to stationary mode and reduced the time required for output to -3dB to measure the steel durability. A magnetic tape for comparison was prepared in which the organic acid salt of the ligand was not added to the magnetic layer or only the ligand was added (compounds C-108 to C-111 in Table 18, compounds D-109 to D-113 in Table 19) . The results are shown in Tables 20 and 21.

compound Level Down (dB) Steel durability C-101 One More than 2 hours C-102 0.5 More than 2 hours C-103 0.5 More than 2 hours C-104 One More than 2 hours C-105 One More than 2 hours C-106 One More than 2 hours C-107 0.5 More than 2 hours Not added 10 More than 2 hours C-108 One 30 minutes C-109 One 80 minutes C-110 0.5 30 minutes C-111 One 60 minutes

compound Level Down (dB) Steel durability D-101 One More than 2 hours D-102 One More than 2 hours D-103 0.5 More than 2 hours D-104 One More than 2 hours D-105 One More than 2 hours D-106 One More than 2 hours D-107 0.5 More than 2 hours D-108 0.5 More than 2 hours Not added 10 More than 2 hours D-109 One 80 minutes D-110 One 60 minutes D-111 One 20 minutes D-112 0.5 30 minutes D-113 One 10 minutes

As can be seen from Tables 20 and 21, as can be seen from the results of Experiment 1 in comparison with a magnetic tape having a ligand in the magnetic layer and a tape having no ligand in the magnetic layer, an organic acid salt of a bipyridine derivative represented by the following formula The magnetic tape containing the organic acid salt of the phenanthrene derivative of 80 in the magnetic layer successfully prevented the leveling down compared with the magnetic tape not containing the organic acid salt of the ligand.

Further, it was found that the magnetic tape including the organic acid salt of the ligand had better steel durability than the tape containing only the ligand. The result is that the addition of the organic acid salt of the ligand prevents the carboxylic acid or the lubricant from bonding to the ligand to form its salt and moving the lubricant to the surface of the magnetic tape to keep the friction rate of the tate low to improve the steel durability . When a ligand is added to the magnetic layer instead of the organic acid salt, the carboxylic acid added as a lubricant reacts with the ligand to form a salt that interferes with the dispersion of the lubricant, thereby suppressing the lubricating effect of the lubricant.

From the above results, it was found that by adding the organic acid salt of the ligand to the magnetic layer on the magnetic tape to suppress the accumulation of the combustion products on the magnetic head, the level down of the output was prevented, the lubricating effect of the lubricant was maintained and the steel durability of the tape was improved Could know.

Experiment 4

In this experiment, the above-mentioned ligand-containing anti-adhesion agent was applied to the vapor-deposited magnetic layer to produce a magnetic tape.

Specifically, Co was first deposited on a polyethylene terephthalate film having a thickness of 10 μm by a four-way vapor deposition method to prepare a ferromagnetic metal thin film. A carbon film having a thickness of 10 nm was coated on the ferromagnetic metal thin film by the sputtering method.

The obtained sheet was cut into a piece having a width of 8 mm, and the adhesion preventive agent was applied to the carbon film by a dipping method to prepare a finished magnetic tape.

The ligands used in Experiments 1 and 2 were dissolved in toluene to obtain the antifouling agent used in this experiment.

Subsequently, a magnetic tape to which the ligand was applied was introduced into a cassette shell to prepare a cartridge. Then, the test was conducted as in Experiment 1. For comparison, a measurement was made on a magnetic tape to which no ligand was added. Each test tape is identified by the type of added ligand, and the evaluation results are recorded in Tables 22 to 24. [

compound Level Down (dB) Presence or absence of combustible materials A-1 0.5 O A-2 0.5 O A-3 1.0 O A-4 0.5 O A-5 0.5 O A-6 0.5 O A-7 1.0 O A-8 1.0 O A-9 1.0 O A-10 1.5 O B-1 0.5 O B-2 0.5 O B-3 0.5 O B-4 1.5 O B-5 0.5 O B-6 0.5 O B-7 1.0 O B-8 1.0 O B-9 1.0 O B-10 1.0 O

compound Level Down (dB) Presence or absence of combustible materials C-1 0.5 O C-2 1.0 O C-3 0.5 O C-4 1.5 O C-5 0.5 O C-6 1.0 O C-7 1.0 O C-8 1.0 O C-9 0.5 O C-10 0.5 O C-11 1.0 O C-12 0.5 O C-13 1.5 O C-14 0.5 O C-15 0.5 O C-16 1.0 O C-17 1.0 O C-18 1.0 O C-19 1.5 O C-20 0.5 O C-21 0.5 O C-22 1.0 O C-23 1.0 O C-24 0.5 O C-28 0.5 O

compound Level Down (dB) Presence or absence of combustible materials D-1 0.5 O D-2 1.0 O D-3 0.5 O D-4 0.5 O D-5 1.0 O D-6 1.0 O D-7 1.0 O D-8 0.5 O D-9 0.5 O D-10 1.0 O D-11 0.5 O D-12 1.5 O D-13 0.5 O D-14 0.5 O D-15 1.0 O D-16 1.0 O D-17 1.0 O D-18 1.5 O D-19 0.5 O D-20 0.5 O D-21 1.0 O D-22 1.0 O D-23 0.5 O D-25 1.5 O D-27 0.5 O Not added 10 X

As can be seen from Figs. 22 and 24, the magnetic tape on which the antifouling agent is not applied on the carbon film has a large level down, and the magnetic tape having the ligand-containing antifouling agent on the level Down is reduced and no combustion occurs on the surface of the magnetic head.

The magnetic head used for recording and reproduction of the magnetic tape to which the ligand was added was subjected to electron microscopic processing and visualized on the basis of a microscope photograph to obtain an image similar to Fig. A magnetic head used for recording and reproduction of a magnetic tape to which no ligand was added was microscopically processed and visualized on the basis of a microscope photograph to obtain an image similar to Fig.

From the above results, it can be seen that the tape having the antifouling agent containing the compound having the pyridine skeleton and one or more ligand sites coated on the carbon film more effectively prevents the generation of the combustibles on the magnetic head running compared to the tape without the ligand Able to know.

Experiment 5

In this experiment, a magnetic tape was prepared by adding the above-mentioned ligand-containing anti-adhesion agent to the undercoating layer formed on the opposite side of the side where the magnetic layer was formed.

Specifically, a coated magnetic layer was formed on a polyethylene terephthalate film having a thickness of 10 mu m by the same method as in Experiment 1. 100 parts by weight of carbon black (average particle diameter: 50 nm), 60 parts by weight of a thermoplastic urethane resin (average molecular weight: 20,000), 60 parts by weight of a copolymer of vinyl chloride and vinyl acetate, 5 parts by weight of olive oil, / Methyl isobutyl ketone / toluene = 2: 1: 1).

The composition was mixed in a ball mill for 10 hours and 3.5 parts by weight of a polyisocyanate and 2.5 parts by weight of a ligand were added.

The resultant was further mixed for 30 hours, and the thus obtained undercoat layer coating was applied to the opposite surface on which the magnetic layer was formed so as to have a dry thickness of 0.8 mu m.

Thereafter, the film was dried, calendered, and cured by heat treatment. The obtained sheet was cut into pieces by the same method as Experiment 1 to prepare a finished magnetic tape.

The ligands used were the same as the ligands of Experiments 1 and 2.

A tape prepared as described above and having a ligand added to the undercoat layer was introduced into a cassette shell to prepare a cartridge, and the same test as in Experiment 1 was conducted. A comparative magnetic tape to which a ligand was not added was prepared and subjected to the same test evaluation. The results are shown in Tables 25-28.

compound Level Down (dB) Presence or absence of combustible materials A-1 1.5 O A-2 1.0 O A-3 1.0 O A-4 1.5 O A-5 1.0 O A-6 1.5 O A-7 1.0 O A-8 0.5 O A-9 1.0 O A-10 0.5 O B-1 1.0 O B-2 1.5 O B-3 1.5 O B-4 1.0 O B-5 0.5 O B-6 1.0 O B-7 1.0 O B-8 0.5 O B-9 1.5 O B-10 1.5 O

compound Level Down (dB) Presence or absence of combustible materials C-24 1.5 O C-25 1.0 O C-26 1.0 O C-27 1.5 O C-28 1.0 O C-29 0.5 O C-30 1.0 O C-31 0.5 O C-32 1.0 O C-33 1.5 O C-34 1.0 O C-35 1.5 O C-36 1.0 O C-37 1.5 O C-38 1.0 O C-39 0.5 O C-40 1.0 O C-41 1.5 O C-42 1.5 O C-43 1.0 O C-44 1.0 O C-45 1.5 O C-46 1.0 O C-47 1.5 O C-48 1.0 O

compound Level Down (dB) Presence or absence of combustible materials D-23 1.0 O D-24 1.5 O D-25 1.0 O D-26 1.5 O D-27 1.0 O D-28 0.5 O D-29 1.5 O D-30 0.5 O D-31 1.0 O D-32 1.0 O D-33 1.5 O D-34 1.5 O D-35 1.0 O D-36 1.0 O D-37 0.5 O D-38 0.5 O D-39 1.0 O D-40 1.5 O D-41 1.0 O D-42 1.5 O D-43 0.5 O D-44 1.5 O D-45 1.0 O D-46 1.5 O D-47 1.5 O

compound Level Down (dB) Presence or absence of combustible materials E-1 1.5 O E-2 1.0 O F-1 1.0 O F-2 1.5 O F-3 0.5 O F-4 1.0 O F-5 0.5 O F-6 0.5 O Not added 10 X

As can be seen from Tables 25 and 28, the magnetic tape to which the ligand is not added in the undercoating layer exhibits a large level-down and does not generate combustion on the surface of the magnetic head, while a magnetic tape Is less level-down and no combustion is generated on the surface of the magnetic head.

The magnetic head used for recording and reproduction of the magnetic tape to which the ligand was added was subjected to electron microscopic processing and visualized on the basis of a microscope photograph to obtain an image similar to Fig. A magnetic head used for recording and reproduction of a magnetic tape to which no ligand was added was microscopically processed and visualized on the basis of a microscope photograph to obtain an image similar to Fig.

From the above results, it can be seen that a tape having a ligand, that is, a compound having a pyridine skeleton and at least one ligand site in the undercoating layer more effectively prevents the generation of combustibles on the magnetic head running compared to a tape to which no ligand is added .

Experiment 6

In this experiment, a titanate-based coupling agent was added to the coated magnetic layer together with one of the ligands to prepare a magnetic tape.

Specifically, 100 parts by weight of a ferromagnetic iron powder (coercive force 150 kA / m, saturation magnetization 145 Am ² / kg, specific surface area 51 m ² / g, major axis length 0.08 μm and needle bed ratio 3), polyvinyl chloride resin (Nippon Zeon Co., Ltd., trade name MR110-TM) 14 parts by weight of the polyester polyurethane resin (Toyobo), 3 parts by weight, Al ₂ O ₃ 5 parts by weight of a titanate coupling agent, 3 parts by weight, stearic acid 1 part by weight, 1 part by weight of heptyl stearate, 150 parts by weight of methyl ethyl ketone, and 150 parts by weight of cyclohexanone.

The composition was kneaded in an extruder and dispersed in a sand mill for 6 hours. 3 parts by weight of polyisocyanate and a ligand in the amount shown in Table 29 were added to the thus obtained coating material to prepare a magnetic paint.

The magnetic paint thus obtained was applied to a polyethylene terephthalate film having a thickness of 7 탆 to obtain a film having a thickness of 6.5 탆. The above magnetic film was passed through the solenoid coil to orientate the film, and the film was dried, calendered and cured to prepare a finished magnetic layer.

100 parts by weight of carbon black (Asahi, # 50), 100 parts by weight of polyester polyurethane resin (Niporun, N-2304), 500 parts by weight of methyl ethyl ketone and 500 parts by weight of toluene.

The compositions were mixed, kneaded and dispersed together to prepare a subbing layer coating. The undercoat layer coating was applied to the surface of the nonmagnetic support opposite to the surface on which the magnetic layer was formed. The obtained coating layer was dried to prepare a primer layer.

A magnetic tape having a magnetic layer formed on one side and a sheet on which the base layer was formed on the other side was cut into a piece having a width of 8 mm to prepare a finished magnetic tape.

A ligand to be added to the magnetic layer was prepared as follows.

Compound A-10: was selected COOH (X = COOH) Select ^{and, R 1 (R 1 -R 4} = H) by -R ⁴ H with a substituent X of formula 64.

Compound B-11: NH ₂ was substituted with substituent Y of formula 64, Cl was substituted with R ⁵ , and H was selected as another substituent.

Compound B-10: OH was substituted with substituent Y of formula 68 and H was selected with R ⁵ -R ¹⁰ .

Compound C-24: H was selected as the substituent R < ¹¹ > -R < ¹⁸ >

Compound C-27: CH ₃ as substituent R ¹¹ , R ¹³ , R ¹⁶ and R ¹⁸ of formula 69 and H as another substituent were selected.

Compound C-28: Substituents R < ¹³ > and R < ¹⁶ >

Compound D-23: H was selected with all substituents of formula (70).

Compound D-26: CH ₃ as the substituent R ¹⁹ , R ²¹ , R ²⁴ and R ²⁶ in the general formula (70), and H as the other substituent.

Compounds E-1 to E-2: The compounds of formulas 71 and 72 were selected.

Compounds F-1, F-3 and F-4: The compounds of formulas 73, 75 and 76 were selected.

Compounds F-5 and F-6: The compounds of formulas 77 and 78 were selected. Substituents in the chemical formulas 73 (R ⁸⁰ -R ⁸⁵ ) and 77 (R ⁹² -R ⁹⁸ ) were all hydrogen atoms.

The titanate coupling agents of formulas 81-85 were used.

The ligand and titanate coupling agent were combined to prepare a magnetic tape added to the magnetic layer. The tape was introduced into a cassette shell and made into a cartridge. The test 1 was conducted to measure the level-down at the time of output. The results are shown in Tables 29 and 30. Table 30 also shows the results from a magnetic tape to which only a titanate-based coupling agent is added or a magnetic tape to which only a ligand is added.

compound Addition of ligand (parts by weight) Titanate coupling agent Level Down (dB) A-10 3 81 0.5 B-11 3 81 0.4 C-24 3 81 0.7 C-24 5 81 0.5 C-24 7 81 0.4 C-24 3 82 0.6 C-24 3 83 0.6 C-24 3 84 0.8 C-24 3 Formula 85 0.8 C-27 3 81 0.8 C-28 3 81 0.5 C-23 3 81 0.4 C-26 3 81 0.4 E-1 3 81 0.5 E-2 3 81 0.6 E-1 3 81 0.5 E-3 3 81 0.4 E-4 3 81 0.4 E-5 3 81 0.4 E-6 3 81 0.5

compound Addition of ligand (parts by weight) Titanate coupling agent Level Down (dB) Not added - 81 6.2 C-24 3 Not added 4.0 C-24 3 81 3.2

From the results of the measurement test, magnetic tapes to which a combination of a ligand and a titanate coupling agent were added to the magnetic layer were less adhered to the surface of the paper-making head than the magnetic tapes to which only the ligand or titanate-based coupling agent was added, There is less level down as shown.

Test results show that tapes with a combination of ligand and titanate-based coupling agents more effectively prevent the formation of combustibles on the running magnetic head compared to tapes with ligands or titanate coupling agents added to the magnetic layer, Also, as shown in Table 30, the level down at the time of output is more effectively prevented.

From the above results, it can be seen that the magnetic tape to which the combination of the ligand and the titanate-based coupling agent is added is further improved in ligand activity, thereby more effectively preventing generation of combustibles on the magnetic head.

In this experiment, the added ligand varied as shown in Fig. 29, and a magnetic tape to which only 0.05 part by weight of ligand was added showed similar results to the tape without added ligand.

The level down at the output is more effectively suppressed when the magnetic tape contains more ligands in the magnetic layer. However, if the addition amount of the ligand exceeds 100 parts by weight, the dispersing power of the magnetic powder will be impaired. That is, the amount of the ligand to be added is preferably 0.3-20 parts by weight, more preferably 0.3-10 parts by weight, based on 100 parts by weight of the magnetic powder.

In this experiment, the titanate-based coupling agent can also be varied in various ways and satisfactory results are obtained. However, the effect is somewhat different. This difference will be due to the difference in the degree of adhesion to the magnetic powder.

In this experiment, a magnetic tape coated with a titanate-based coupling agent on the surface of the magnetic layer was produced. The obtained tape was not remarkably reduced in level-down. From these results, it was concluded that the titanate-based coupling agent is preferably added to the autotrophs rather than to the surface of the magnetic layer.

Review of magnetic recording medium 2

In Experiments 7 to 12, diketone compounds (ligands) were held on a magnetic recording medium and the effect of the medium on the running properties was studied.

Experiment 7

In this experiment, an anti-adhesion agent containing a compound (ligand) having a pyridine skeleton and two or more ligand sites was held in a coated magnetic layer to prepare a magnetic tape, and a signal was recorded and reproduced using a magnetic tape.

Specifically, 100 parts by weight of a needle-like ferromagnetic iron powder (specific surface area: 53.9 cm ² / g, coercive force: 1580 Oe, saturation magnetization: 120 emu / g), 10 parts by weight of a thermoplastic polyurethane resin (average molecular weight: 20,000) 10 parts by weight of a copolymer of vinyl acetate and vinyl acetate, 5 parts by weight of carbon (average particle diameter 150 nm), 5 parts by weight of? -Alumina (average particle diameter 200 nm), 3 parts by weight of olive oil, / Toluene = 2: 1: 1): 220 parts by weight.

These components were mixed in a ball mill for 48 hours, 3.5 parts of a reinforcing agent consisting of polyisocyanate were added, and the resultant was mixed for a further 30 minutes.

The magnetic paint thus obtained was coated on the opposite side of the side where the magnetic layer was formed so that the dry thickness became 2 μm. The film was then dried and calendered and allowed to cure in an oven at 60 DEG C for 20 hours.

The sheet was cut into a piece having a width of 8 mm, and the following antifouling agent was applied to the magnetic layer by a dipping method to prepare a magnetic tape.

The anti-adhesion agent used here was prepared by dissolving the ligand of formula 86 (diketone compound H-1) in toluene.

Then, a magnetic tape having the ligand was placed in a cassette shell to prepare a cartridge. Then, the following measurement test was carried out. For comparative purposes, a similar measurement test was performed on a magnetic tape without the above-mentioned antifouling agent.

More specifically, the magnetic head shown in FIG. 1, that is, a pair of magnetic core ends 1 and 2 is formed of a ferromagnetic oxide such as single crystal ferrite and has a high magnetic flux density Bs having a high saturation magnetic flux density Bs such as FeAlSi- The metal thin film 3 is deposited on the surfaces of the two ends facing each other at regular intervals and the metal thin film is arranged obliquely in parallel so that the ferromagnetic metal thin film 3 faces each other A video tape recorder having a magnetic head was manufactured.

Using such a videotape recorder, a signal was recorded on the test magnetic tape for 1 minute and the signal was reproduced therefrom. During this, the output from the tape was measured. Thereafter, a signal of the tape was recorded for 20 minutes, and the regenerating mechanism was repeated ten times and the output was measured. The final test output was compared to the initial output to calculate the final output drop (level down) based on the initial output.

After the recording and reproducing mechanism of the tape was performed as described above, the tape was removed from the video tape recorder and the friction surface, that is, the surface on which the magnetic head traveled, was observed with an electron microscope. As a result of electron microscopic observation, on the friction surface of the magnetic tape, X was marked when the combustible adhered to the ferromagnetic metal thin film (3). Electron microscope observation indicated O when the combustible does not appear in the ferromagnetic metal film (3).

The results of the level down and electron microscopic observations on the test tape are set forth in Table 31, with the corresponding results from the tape not containing an anti-adhesion agent.

compound Level Down (dB) Presence or absence of combustible materials H-1 0.5 O Not added 10 X

As shown in Table 3, in the magnetic tape not coated with the anti-adherence agent on the magnetic layer, a large level down occurs at the time of output, and the combustible remains on the running magnetic head. On the contrary, the magnetic tape having the ligand or compound H-1 containing anti-adhesion agent has less level-down and does not remain on the traveling magnetic head.

Fig. 2 is a schematic diagram of a magnetic head based on an electron microscope photograph, which is used for recording and reproduction on a magnetic tape having an anti-adhesion agent containing a ligand to be applied.

3 is a schematic view of a magnetic head based on an electron micrograph, which is used for recording and reproducing on a magnetic tape having no antistatic agent applied on the magnetic layer.

Fig. 3 shows that the combustible 4 is generated in the ferromagnetic metal thin film 3, while Fig. 2 shows that no combustible 4 is generated as in the case of recording and reproduction.

From the above results, it can be seen that the use of a tape having an anti-adhesion agent containing a diketone compound can prevent the generation of combustion products on the running magnetic head.

Experiment 8

In this experiment, a magnetic tape was prepared by adding an anti-adhesion agent containing a carboxylic acid together with the ligand to the coated magnetic layer.

Specifically, 6 parts by weight of a carboxylic acid (oleic acid or myristic acid) and 5 parts by weight of a ligand were further added to the same composition as that used in Experiment 7. The obtained composition was mixed, the reinforcing agent was added, and mixed in the same manner as in Experiment 1.

As in Experiment 7, the magnetic paint thus obtained was applied to a polyethylene terephthalate film, followed by drying and calendering. Then, the sheet was heat-treated and cured to form a magnetic layer. The sheet was cut into pieces to prepare a finished magnetic tape. In this experiment, an anti-adhesion agent was added to the magnetic layer and was not applied to the surface of the magnetic layer.

As the anti-sticking agent to be added to the magnetic layer, in addition to the compound H-1 used in Experiment 1, there are the compounds G-1 to G-9 prepared by selecting the substituent R ²⁷ -R ²⁹ of the formula 87 as shown in Table 32.

In the formulas, R ²⁷ to R ^{29 each} represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group, .

compound R ²⁷ R ²⁸ R ²⁹ G-1 H H H G-2 H Aryl group Aryl group G-3 H CH ₃ CH ₃ G-4 Aryl group CH ₃ CH ₃ G-5 H CF ₃ CH ₃ G-6 Aryl group CF ₃ flan G-7 H CF ₃ flan G-8 Aryl group CF ₃ Thiophene G-9 H CF ₃ Thiophene

Compounds G-5 and G-7 are compounds of formula 88 wherein substituent R ²⁹ is a plan, and compounds A-8 and A-9 are compounds of formula 89 wherein substituent R ²⁹ is thiophene.

A magnetic tape in which the ligand and oleic acid were combined and added to the magnetic layer was prepared. The ligand and oleic acid were combined to produce another kind of magnetic tape added to the magnetic layer. After the tape was introduced into the cassette shell to make it into a cartridge, the following measurement test was carried out. A comparative tape to which only oleic acid or myristic acid was added to the magnetic layer was prepared and the same measurement test was conducted.

A measurement test was carried out in the same manner as in Experiment 7. The evaluation results are shown in Table 33 together with the combination of the carboxylic acid and the ligand added to the magnetic layer. Table 33 shows magnetic tape evaluation results in which only oleic acid or myristic acid is added to the magnetic layer.

compound Carboxylic acid Level Down (dB) Presence or absence of combustible materials G-1 Oleic acid 1.0 O G-1 Myristic acid 0.5 O G-2 Oleic acid 0.5 O G-2 Myristic acid 0.5 O G-3 Oleic acid 0.5 O G-3 Myristic acid 0.5 O G-4 Oleic acid 1.0 O G-4 Myristic acid 0.5 O G-5 Oleic acid 0.5 O G-5 Myristic acid 0.5 O G-6 Oleic acid 1.0 O G-6 Myristic acid 1.0 O G-7 Oleic acid 1.0 O G-7 Myristic acid 1.0 O G-8 Oleic acid 1.5 O G-8 Myristic acid 1.0 O G-9 Oleic acid 0.5 O G-9 Myristic acid 0.5 O H-1 Oleic acid 0.5 O H-1 Myristic acid 0.5 O G-9 Not added 4.0 X Not added Oleic acid 10 X Not added Myristic acid 10 X

As shown in Table 33, in the magnetic tape to which only the carboxylic acid is added to the magnetic layer, a large level down occurs at the time of output, and a combustible is generated on the surface of the magnetic head. Conversely, a magnetic tape having a magnetic layer to which a compound ligand and a carboxylic acid combination is added does not show level-down, and does not accumulate combustibles on the magnetic head.

Magnetic tape with only a ligand added to the magnetic layer and a carboxylic acid-free magnetic tape produced some combustibles on the surface of the magnetic head but were less generated than magnetic tapes that did not contain a ligand. The magnetic tape to which only the ligand is added and the carboxylic acid is not added is also leveled down to about -4 dB. From this, it can be seen that the addition of the carboxylic acid to the ligand enhances the effect of preventing the ligand from adhering the combustible on the magnetic head. This may be because the carboxylic acid is attached to the magnetic particles to prevent the ligand from attaching to the magnetic particles.

A magnetic head used for recording and reproduction on a magnetic tape to which a combination of a ligand and a carboxylic acid was added was subjected to electron microscopic processing and visualized on the basis of a microscope photograph to obtain an image similar to Fig. A magnetic head used for recording and reproduction on a magnetic tape to which only a carboxylic acid was added was subjected to electron microscopic processing and visualized on the basis of a microscope photograph to obtain an image similar to Fig.

From the above results, it can be seen that a tape to which a ligand, that is, a combination of a diketone compound and a carboxylic acid is added, more effectively prevents combustion products from being generated on a magnetic head running compared to a tape to which only a ligand or carboxylic acid is added have.

Further, as a result of conducting tests on a tape coated with a carboxylic acid in the magnetic layer, it was found that such a treatment did not significantly affect the level-down improvement at the time of output. Therefore, it is more preferable to add a carboxylic acid in the magnetic layer than to coat the carboxylic acid on the magnetic layer.

Experiment 9

In this experiment, the ligand-containing anti-adhesion agent was applied to the coated magnetic layer to prepare a magnetic tape.

Specifically, Co was first deposited on a polyethylene terephthalate film having a thickness of 10 占 퐉 by a four-way vapor deposition method to prepare a ferromagnetic metal thin film having a thickness of 100 nm. A carbon film having a thickness of 10 nm was formed on the ferromagnetic metal thin film by sputtering.

The obtained sheet was cut into a piece having a width of 8 mm, and the adhesion preventive agent was applied to the carbon film by a dipping method to prepare a finished magnetic tape.

The ligands used in the compounds G-1 to G-9 or Experiments 1 and 2 were dissolved in toluene to obtain an anti-adhesion agent used in this experiment.

Subsequently, a magnetic tape to which the ligand was applied was introduced into a cassette shell to prepare a cartridge. Then, the test was conducted as in Experiment 7. For comparison, a measurement was made on a magnetic tape to which no ligand was added. Record the test results in Table 39.

compound Level Down (dB) Presence or absence of combustible materials G-1 1.0 O G-2 1.0 O G-3 1.0 O G-4 1.0 O G-5 1.5 O G-6 1.0 O G-7 1.0 O G-8 1.0 O G-9 1.0 O Not added 10 X

As can be seen from FIG. 34, in the magnetic tape not coated with the antifouling agent on the carbon film, a large level down occurs at the time of output, and a combustible material is generated on the surface of the magnetic head, while the magnetic tape having the ligand- The level is not leveled down and no combustion occurs on the surface of the magnetic head.

A magnetic head used for recording / reproducing the magnetic tape to which the ligand was applied was electron-microscopically processed and visualized on the basis of a microscope photograph to obtain an image similar to Fig. A magnetic head used for recording and reproduction of a magnetic tape to which no ligand was added was microscopically processed and visualized on the basis of a microscope photograph to obtain an image similar to Fig.

From the above results, it was found that a tape coated with a ligand on a carbon film, that is, a tape having a diketone compound-containing anti-adhesion agent effectively prevents combustion products from being formed on a magnetic head running compared to a tape to which a ligand is not added.

Experiment 10

In this experiment, a magnetic tape was prepared by coating the surface of the coated magnetic layer with an anti-adhesion agent containing a phosphorus oxy compound together with the ligand.

Specifically, first, a ferromagnetic metal thin film and a carbon film were formed as in Experiment 9, and the obtained sheet was cut into pieces to prepare magnetic tapes. A magnetic tape having a finishing treatment was prepared by applying an anti-adhesion agent prepared by dissolving a phosphorus-containing compound together with a ligand in toluene on a magnetic tape.

The ligands added to the anti-adhesion agent are the same compounds as those used in the compounds G-1 to G-8 or Experiment 9.

The phosphorus-containing compound added to the anti-adhesion agent together with the ligand is a compound of the formula 90-93. Specifically, the phosphorus-containing compound is a compound in which the substituent R ³⁰ -R ⁴¹ is the same as the substituent R ³⁰ -R ⁴¹ in the row of K-1, K-2, L-1, L-2, M-1, M- ≪ / RTI >

In the formula, R ³⁰ -R ³² represents a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group substituted with the above- Click aromatics.

In the formulas, R ^{33 to} R ³⁵ may be the same or different and each represents a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group, Click aromatics.

In the formulas, R ^{36 to} R ^{38 each} represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group substituted with the aforementioned atoms and groups, Click aromatics.

In the formulas, R ^{39 to} R ^{41 each} represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group substituted with the aforementioned atoms and groups, Click aromatics.

compound R ³⁰ , R ³³ , R ³⁶ , R ³⁹ R ³¹ , R ³⁴ , R ³⁷ , R ⁴⁰ R ³² , R ³⁵ , R ³⁸ , R ⁴¹ K-1 R ³⁰ = C ₁₂ H ₂₅ R ³¹ = C ₁₂ H ₂₅ R ³² = C ₁₂ H ₂₅ K-2 R ³⁰ = C ₁₈ H ₃₇ R ³¹ = C ₁₈ H ₃₇ R ³² = C ₁₈ H ₃₇ L-1 R ³³ = C ₁₂ H ₂₅ R ³⁴ = C ₁₂ H ₂₅ R ³⁵ = C ₁₂ H ₂₅ L-2 R ³³ = C ₁₈ H ₃₇ R ³⁴ = C ₁₈ H ₃₇ R ³⁵ = C ₁₈ H ₃₇ M-1 R ³⁶ = C ₁₂ H ₂₅ R ³⁷ = C ₁₂ H ₂₅ R ³⁸ = C ₁₂ H ₂₅ M-2 R ³⁶ = C ₁₈ H ₃₇ R _³⁷ = C ₁₈ H ³⁷ R ³⁸ = C ₁₈ H ₃₇ N-1 R ³⁹ = C ₁₂ H ₂₅ R ⁴⁰ = C ₁₂ H ₂₅ R ⁴¹ = C ₁₂ H ₂₅ N-1 R ³⁹ = C ₁₈ H ₃₇ R ⁴⁰ = C ₁₈ H ₃₇ R ⁴¹ = C ₁₈ H ₃₇

Subsequently, a magnetic tape to which an anti-adhesion agent containing the ligand and phosphorus-containing compound was applied was placed in a cassette shell to prepare a cartridge. Then, a measurement test as in Experiment 7 was carried out. For comparison, a similar measurement test was performed on a magnetic tape not coated with a surface of the above-mentioned antistatic agent containing no ligand. Record the evaluation results in Table 36.

compound Phosphorus-containing compound Level Down (dB) Presence or absence of combustible materials G-1 K-1 0.7 O G-1 K-2 1.0 O G-1 L-1 0.6 O G-1 L-2 0.7 O G-1 M-1 0.4 O G-1 M-2 0.6 O G-1 N-1 0.9 O G-1 N-2 1.2 O G-2 K-1 0.6 O G-2 L-1 0.7 O G-3 K-1 0.6 O G-4 K-1 0.7 O G-4 L-1 0.6 O G-4 M-1 0.4 O G-5 K-1 0.9 O G-6 K-1 0.6 O G-6 L-1 0.6 O G-7 K-1 0.7 O G-8 K-1 0.7 O G-8 L-1 0.7 O Not added K-1 8.0 X Not added K-2 9.5 X Not added L-1 7.0 X Not added L-2 8.0 X Not added M-1 6.0 X Not added M-2 7.0 X Not added N-1 8.0 X Not added N-2 9.0 X

As shown in Table 36, the magnetic tape coated with the phosphorus-containing compound only on the surface causes a large level-down in output, resulting in combustion on the surface of the magnetic head. Conversely, a tape coated with a combination of a compound ligand and a phosphorus oxy compound on the surface does not show level-down, and no combustible is accumulated on the surface of the magnetic head.

In Experiment 9, a magnetic tape on which only a ligand was coated without using a phosphorus-containing compound in a magnetic layer was subjected to measurement test. From the test results it can be seen that the magnetic tape comprising the ligand together with the phosphorus containing compound shows better results than the tape comprising the ligand only if the ligand is limited to that used in Experiment 9.

A magnetic head used for recording and reproduction on a magnetic tape coated with a combination of a ligand and a phosphorus-containing compound was electron-microscopically processed and visualized on the basis of a microscope photograph to obtain an image similar to Fig. A magnetic head used for recording and reproduction on a magnetic tape to which only a phosphorus-containing compound was added was electron-microscopically treated and visualized on the basis of a microscope photograph to obtain an image similar to Fig.

From the above results, it can be seen that a tape to which a combination of a ligand, that is, a diketone compound and a phosphorus compound, is added to the magnetic layer more effectively prevents combustion products from being formed on the magnetic head running compared to a tape to which the combination is not added have.

Experiment 11

In this experiment, a magnetic tape was prepared by adding the above-mentioned ligand-containing anti-adhesion agent to the undercoating layer formed on the opposite side of the side where the magnetic layer was formed.

Specifically, a coated magnetic layer was first formed on a polyethylene terephthalate film having a thickness of 7 占 퐉 in the same manner as in Experiment 7. 100 parts by weight of carbon black (average particle diameter: 50 nm), 60 parts by weight of a thermoplastic urethane resin (average molecular weight: 20,000), 60 parts by weight of a copolymer of vinyl chloride and vinyl acetate, 5 parts by weight of olive oil, / Methyl isobutyl ketone / toluene = 2: 1: 1).

The composition was mixed in a ball mill for 10 hours and 3.5 parts by weight of a polyisocyanate and 2.5 parts by weight of a ligand were added.

The resultant was further mixed for 30 hours, and the thus obtained undercoat layer coating was applied to the opposite surface on which the magnetic layer was formed so as to have a dry thickness of 0.8 mu m.

Thereafter, the film was dried, calendered, and cured by heat treatment. The obtained sheet was cut into pieces by the same method as Experiment 1 to prepare a finished magnetic tape.

The ligands used were the same as the compounds G-1 to G-9, and H-1 or ligands of Experiments 7 and 10.

A tape prepared as described above and having a ligand added to the undercoat layer was introduced into a cassette shell to prepare a cartridge, and the same test as in Experiment 7 was performed. A comparative magnetic tape to which a ligand was not added was prepared and subjected to the same test evaluation. The results are shown in Table 37.

compound Level Down (dB) Presence or absence of combustible materials G-1 1.5 O G-2 0.5 O G-3 1.0 O G-4 1.0 O G-5 1.0 O G-6 0.5 O G-7 1.5 O G-8 1.0 O G-9 1.5 O H-1 0.5 O Not added 10 X

As can be seen from Table 37, a magnetic tape without a ligand added to the underlayer exhibits a large level-down on output and a combustible on the surface of the magnetic head while a magnetic tape with a ligand added to the underlayer Level down does not appear and no combustion is generated on the surface of the magnetic head.

A magnetic head used for recording and reproduction of a magnetic tape to which a ligand was added to the undercoat layer was subjected to electron microscopic processing and visualized on the basis of a microscope photograph to obtain an image similar to Fig. A magnetic head used for recording and reproduction on a magnetic tape to which a ligand was not added to the underlayer was microscopically processed and visualized on the basis of a microscope photograph to obtain an image similar to Fig.

From the above results, it can be seen that a tape having a ligand, that is, a diketone compound, in the undercoat layer prevents combustion products from being formed on the running magnetic head.

Experiment 12

In this experiment, a magnetic tape was prepared by adding an anti-adhesion agent containing a titanate-based coupling agent together with one of the ligands to a coated magnetic layer.

Specifically, 100 parts by weight of a ferromagnetic iron powder (coercive force 160 kA / m, saturation magnetization 145 A m ² / kg, specific surface area 51 m ² / g, long axis length 0.08 μm and needle bed ratio 3) 100 parts by weight polyvinyl chloride resin 14 parts by weight of a polyester polyurethane resin (Toyobo), 5 parts by weight of Al ₂ O ₃ , 3 parts by weight of a titanate coupling agent, 1 part by weight of stearic acid, 1 part by weight, methyl ethyl ketone 150 parts by weight, and cyclohexanone 150 parts by weight.

The composition was kneaded in an extruder and dispersed in a sand mill for 6 hours. 3 parts by weight of polyisocyanate and a ligand in the amount shown in Table 39 were added to the thus obtained coating material to prepare a magnetic paint.

The magnetic paint thus obtained was applied to a polyethylene terephthalate film having a thickness of 7 탆 to obtain a film having a thickness of 6.5 탆. The above magnetic film was passed through the solenoid coil to orientate the film, and the film was dried, calendered and cured to prepare a finished magnetic layer.

100 parts by weight of carbon black (Asahi, # 50), 100 parts by weight of polyester polyurethane resin (Niporun, N-2304), 500 parts by weight of methyl ethyl ketone and 500 parts by weight of toluene.

The compositions were mixed, kneaded and dispersed together to prepare a subbing layer coating. The undercoat layer coating was applied to the surface of the nonmagnetic support opposite to the surface on which the magnetic layer was formed. The obtained coating layer was dried to prepare a primer layer. A magnetic tape having a magnetic layer formed on one side and a sheet on which the underlayer was formed on the other side was cut into a piece having a width of 8 mm to prepare a finished magnetic tape.

The ligands to be added to the magnetic layer were the compounds G-10 to G-16 of the formula 87 as shown in Table 38 wherein the substituents R ²⁷ , R ²⁸ and R ²⁹ are as shown in Table 38.

compound R ¹ R ² R ³ G-10 CH ₃ H CH ₃ G-11 C ₆ H ₅ H CH ₃ G-12 (CH _{3) 3} C H (CH _{3) 3} C G-13 (CH _{3) 3} C H (CH _{3) 3} C G-14 H CH ₃ H G-15 H C ₃ H ₇ H G-16 CH ₃ CH ₃ CH ₃

The ligand and titanate coupling agent were combined to produce a magnetic tape added into the magnetic layer. The tape was introduced into a cassette shell and made into a cartridge. The test 7 was conducted to measure the level-down at the time of output. Table 39 shows the results. Table 39 shows the results from a magnetic tape to which only a titanate-based coupling agent is added or a magnetic tape to which only a ligand is added.

compound Addition of ligand (parts by weight) Titanate coupling agent Level Down (dB) G-10 One 94 0.2 G-10 3 94 1.0 G-10 5 94 0.8 G-10 7 94 0.8 G-10 10 94 0.5 G-10 3 95 0.8 G-10 3 96 0.9 G-10 3 97 1.1 G-10 3 98 1.3 G-11 3 94 1.0 G-12 3 94 1.2 G-13 3 94 1.1 G-14 3 94 1.0 G-15 3 94 0.8 G-16 3 94 0.8 Not added - 94 6.2 G-10 3 Not added 4.2 G-10 0.05 94 3.5

From the results of the measurement test, the magnetic tape to which the combination of the ligand and the titanate coupling agent is added to the magnetic layer is less attached to the surface of the magnetic head than the magnetic tape to which only the ligand or titanate-based coupling agent is added to the magnetic layer, Less leveling down as described.

From the test results, a tape to which a combination of a ligand and a titanate-based coupling agent is added more effectively prevents combustion products from being formed on a magnetic head that travels compared to a tape to which a ligand or titanate coupling agent is added to the magnetic layer.

In this experiment, the ligand to be added varied as shown in Fig. 39, and a magnetic tape to which only 0.05 part by weight of the ligand was added showed similar results to the tape without the ligand.

The level down at the output is more effectively suppressed when the magnetic tape contains more ligands in the magnetic layer. However, if the addition amount of the ligand exceeds 100 parts by weight, the dispersing power of the magnetic powder will be impaired. That is, the amount of the ligand to be added is preferably 0.3-20 parts by weight, more preferably 0.3-10 parts by weight, based on 100 parts by weight of the magnetic powder.

In this experiment, the titanate-based coupling agent can also be varied in various ways and satisfactory results are obtained. However, the effect is somewhat different. This difference will be due to the difference in the degree of adhesion to the magnetic powder.

In this experiment, a magnetic tape coated on the surface of the magnetic layer was prepared instead of the titanate-based coupling agent added into the magnetic layer. The tape obtained did not significantly affect the level down reduction. From these results, it was concluded that the titanate-based coupling agent is preferably added to the autotrophs rather than to the surface of the magnetic layer.

Review of cleaning tape

First, in Experiments 13 to 15, a compound (ligand) having a pyridine skeleton and two or more ligand sites was held on a cleaning tape and the effect on the tape performance was studied.

Experiment 13

A cleaning tape was prepared as follows.

Specifically, 10 parts by weight of a thermoplastic polyurethane resin (average molecular weight: 20,000), 10 parts by weight of a copolymer of vinyl chloride and vinyl acetate, 5 parts by weight of carbon (average particle size: 150 nm), 5 parts by weight of a ligand Ethyl ketone / methyl isobutyl ketone / toluene = 2: 1: 1).

These components were mixed in a ball mill for 48 hours, 3.5 parts of a reinforcing agent consisting of polyisocyanate were added, and the resultant was mixed for a further 30 minutes.

The magnetic paint thus obtained was applied to a polyethylene terephthalate film having a thickness of 7 탆 to obtain a film having a dry thickness of 2 탆. The film was then dried and allowed to cure in an oven at 60 DEG C for 20 hours. The sheet was cut into a piece having a width of 8 mm to prepare a finished cleaning tape.

B-1, B-2 and B-10 of the formula 64, C-24, C-25 and C-25 of the formula 69 are used as the ligand (antiadhesive agent) -35, and compounds D-23 to D-28 of formula 70, and D-34 and D-35. In addition to the above, the following ligands were prepared.

Compound B-12: COOH as substituent Y in formula 68, nC ₃ H ₇ as R ⁵ and H as another substituent were selected.

Compound B-13: OH was selected as substituent Y in formula 68, F was selected as R ⁵ and H was selected as another substituent.

Compound B-14: OH was substituted with substituent Y of formula 68, Cl was replaced with R ⁵ , and H was selected as another substituent.

Compound B-15: OH was selected as substituent Y in formula 68, NH ₂ as R ⁵ and H as another substituent.

Compound B-16: OH was selected as substituent Y in formula 68, NO ₂ as R ⁵ and H as another substituent.

Compound B-17: OH was selected as substituent Y in formula 68, SO ₃ H as R ⁵ and H as another substituent.

Compound B-18: for the CH H OH a substituent Y in the formula 68, with R ^5, with R ^6, were selected for H to another substituent.

Compound C-49: H was selected as the substituent R ¹³ , R ¹⁶ in Formula 69, and H was selected as the other substituent.

Compound C-50: Cl was substituted with substituent R ¹¹ , R ¹⁸ in Formula 69, and H was selected as another substituent.

Compound D-48: Substituent R ¹⁹ of formula 70, Cl as R ²⁶ and H as another substituent were selected.

A cleaning tape of the above composition was placed in a cassette shell to prepare a cartridge. Then, the following measurement test was carried out.

For comparison, a similar measurement test was carried out on a comparative cleaning tape without a ligand in the cleaning layer.

Specifically, a videotape recorder manufactured similarly to Experiment 1 was first prepared, and a signal was recorded on the test magnetic tape for 1 minute. The signal reproduction from this was repeated to obtain a level down of 5 dB. A cleaning tape was applied to the same video tape whose signal from the tape was reduced by 5 dB and run for 1 minute. Thereafter, the same magnetic tape was regenerated and the output was measured to check the degree of reproduction of the output. And the playback output is shown as a comparison value when the initial output value of the same tape is set to 0 dB. The regenerated output is shown in Tables 40 to 44 along with compounds of various ligands added to the cleaning tape.

compound Level Down Recovery (dB) A-1 4 A-2 3 A-3 4 A-4 3 A-5 3 A-6 3 A-7 3 A-8 4 A-9 4 A-10 3

compound Level Down Recovery (dB) B-1 4 B-2 3 B-10 4 B-12 4 B-13 4 B-14 4 B-15 4 B-16 4 B-17 3 B-18 4

compound Level Down Recovery (dB) C-24 4 C-25 4 C-35 3 C-49 2 C-50 3

compound Level Down Recovery (dB) D-23 4 D-24 4 D-25 3 D-26 3 D-27 4 D-28 4 D-34 4 D-35 3 D-47 3

compound Level Down Recovery (dB) E-1 4 E-2 4 F-1 3 F-3 4 F-4 4 F-5 3 F-6 4 Not added 0

As can be seen from Tables 40 to 44, when the cleaning tape having the ligand in the cleaning layer is reproduced in the videotape recorder on which the cleaning tape is run, as compared with the case where the cleaning tape on which the ligand is not added or not applied, Lt; / RTI >

Experiment 14

A cleaning tape was prepared in the same manner as in Experiment 13 except that the ligand was dissolved in a solvent instead of adding to the cleaning layer and the solution was applied to the surface of the cleaning layer by dipping. The type of ligand to be solubilized was the same as in Experiment 13, and the concentration of the solution was 10 mM. The solvent was a mixture of toluene and alcohol.

A cleaning tape of the above composition was placed in a cassette shell to prepare a cartridge, and the same measurement test as in Experiment 13 was carried out. That is, the magnetic tape was run through the video tape recorder until a certain level down occurred, the test cleaning tape was run on the same recorder, and the same magnetic tape was immediately reproduced on the same recorder and the recovery of the level down was checked. For comparison, a cleaning tape with no or no ligand added was prepared and subjected to the same measurement test. The results are shown in Tables 45 to 49 below.

compound Level Down Recovery (dB) A-1 4 A-2 4 A-3 4 A-4 3 A-5 3 A-6 3 A-7 3 A-8 4 A-9 4 A-10 3

compound Level Down Recovery (dB) B-1 3 B-2 3 B-10 4 B-12 4 B-13 4 B-14 3 B-15 4 B-16 4 B-17 4 B-18 3

compound Level Down Recovery (dB) C-24 4 C-25 4 C-35 4 C-49 3 C-50 3

compound Level Down Recovery (dB) D-23 4 D-24 4 D-25 3 D-26 3 D-27 3 D-28 4 D-34 3 D-35 3 D-47 4

compound Level Down Recovery (dB) E-1 3 E-2 3 F-1 3 F-3 3 F-4 3 F-5 4 F-6 3 Not added 0

As can be seen from Tables 45 to 49, when the cleaning tape having the ligand in the cleaning layer was reproduced in the videotape recorder running, the level-down recovery was more remarkable than that in the case where the cleaning tape with no ligand added or no coating was run Respectively.

Experiment 15

The ligand was dissolved in a 10 mM mixed solution of toluene and alcohol. On the other hand, a polypropylene nonwoven fabric (Dexter, grade 193) was cut into pieces each having a width of 8 mm, and each of them was subjected to a solution containing a ligand to prepare a cleaning tape.

A cleaning tape of the above composition was placed in a cassette shell to prepare a cartridge, and the same measurement test as in Experiment 13 was carried out. That is, the magnetic tape was run through the video tape recorder until a certain level down occurred, the test cleaning tape was run on the same recorder, and the same magnetic tape was immediately reproduced on the same recorder and the recovery of the level down was checked. Together with the compounds of the various ligands added to the cleaning tape, the results are shown in Tables 50 to 54 below.

compound Level Down Recovery (dB) A-1 4 A-2 3 A-3 4 A-4 4 A-5 4 A-6 3 A-7 4 A-8 5 A-9 5 A-10 3

compound Level Down Recovery (dB) B-1 4 B-2 4 B-10 4 B-12 4 B-13 4 B-14 3 B-15 4 B-16 4 B-17 4 B-18 3

compound Level Down Recovery (dB) C-24 4 C-25 4 C-35 4 C-49 4 C-50 4

compound Level Down Recovery (dB) D-23 4 D-24 4 D-25 4 D-26 3 D-27 4 D-28 4 D-34 3 D-35 4 D-47 3

compound Level Down Recovery (dB) E-1 4 E-2 4 F-1 4 F-3 3 F-4 3 F-5 4 F-6 4 Not added 0

As can be seen from Tables 50 to 54, the level down was significantly restored when the magnetic tape was reproduced in the videotape recorder on which the cleaning tape impregnated with the ligand was running.

From the results of Experiments 13 to 15, it was found that a compound (ligand) having a pyridine skeleton and two or more ligand sites was suitable as a cleaning agent when added to a cleaning tape. When applied to the surface of the non-magnetic support or to the surface of the cleaning layer or to the cleaning layer of the cleaning tape, the ligand is effective for cleaning the magnetic tape on which the tape travels.

Review of cleaning tape 2

In Experiments 16 to 18, the effect of the diketone compound (ligand) on the cleaning tape and the tape performance was studied.

Experiment 16

A cleaning tape was prepared as follows.

Specifically, 10 parts by weight of a thermoplastic polyurethane resin (average molecular weight: 20,000), 10 parts by weight of a copolymer of vinyl chloride and vinyl acetate, 5 parts by weight of carbon (average particle size: 150 nm), 5 parts by weight of a ligand, Ethyl ketone / methyl isobutyl ketone / toluene = 2: 1: 1).

These components were mixed in a ball mill for 48 hours, 3.5 parts of a reinforcing agent consisting of polyisocyanate were added, and the resultant was mixed for a further 30 minutes.

The magnetic paint thus obtained was applied to a polyethylene terephthalate film having a thickness of 7 탆 to obtain a film having a dry thickness of 2 탆. The film was then dried and calendered and allowed to cure in an oven at 60 DEG C for 20 hours. The sheet was cut into pieces each having a width of 8 mm to prepare a finished cleaning tape.

The ligands used herein are the compound H-1 of the formula 86 and the compounds G-1 to G-9 of the formula 87 described above for the measurement test of the magnetic recording medium.

A cleaning tape of the above composition was placed in a cassette shell to prepare a cartridge. Then, the following measurement test was carried out.

For comparison, similar measurement tests were performed on a cleaning tape without ligand.

That is, the magnetic tape was run on the same video tape recorder as that used in Experiment 7 for 20 minutes to record a signal, and signal regeneration was repeated until a level down of 20 dB was obtained. The test cleaning tape was run on the same videotape for one minute, and immediately after running, the same magnetic tape was placed on the same recorder to regenerate the same signal and check the level-down recovery. The results are shown in Tables 50 to 54 along with the compounds of various ligands added to the cleaning tape. The recovery output is shown as a comparison value when the initial output of the same tape is 0 dB. Recovery output is recorded in Table 55 along with compounds of various ligands added to the cleaning tape.

compound Level Down Recovery (dB) G-1 4 G-2 4 G-3 4 G-4 4 G-5 3 G-6 4 G-7 4 G-8 4 G-9 3 H-1 4 Not added 0

As can be seen from Table 55, the recovery of the level-down was more remarkable when the cleaning tape having the ligand in the cleaning layer was reproduced in the videotape recorder on which the cleaning tape was running, than when the cleaning tape on which the ligand was not added or not .

Experiment 17

A cleaning tape was prepared in the same manner as in Experiment 16, except that the ligand was dissolved in a solvent instead of added to the cleaning layer, and the solution was applied to the surface of the cleaning layer by a dipping method. The type of ligand to be solubilized was the same as in Experiment 16, and the concentration of the solution was 10 mM. The solvent was a mixture of toluene and alcohol.

A cleaning tape of the above composition was placed in a cassette shell to prepare a cartridge, and the same measurement test as in Experiment 16 was carried out. That is, the magnetic tape was run through the video tape recorder until a certain level down occurred, the test cleaning tape was run on the same recorder, and the same magnetic tape was immediately reproduced on the same recorder and the recovery of the level down was checked. For comparison, a cleaning tape with no or no ligand added was prepared and subjected to the same measurement test. The results are shown in Table 56 together with the compounds of various ligands applied to the cleaning tape.

compound Level Down Recovery (dB) G-1 4 G-2 4 G-3 3 G-4 4 G-5 3 G-6 4 G-7 4 G-8 4 G-9 3 H-1 4 Not added 0

As can be seen from Table 56, the level-down recovery was more remarkable when the cleaning tape having the ligand in the cleaning layer was reproduced in the videotape recorder on which the cleaning tape was running, than the cleaning tape on which the ligand was not added or was not applied.

Experiment 18

The ligand was dissolved in a 10 mM mixed solution of toluene and alcohol. On the other hand, a nonwoven fabric (Dexter, grade 193) made of polypropylene was cut into pieces each having a width of 8 mm, and a cleaning tape was prepared by immersing each of the pieces with a ligand-containing solution.

A cleaning tape of the above composition was placed in a cassette shell to prepare a cartridge, and the same measurement test as in Experiment 16 was carried out. That is, the magnetic tape was run through the video tape recorder until a certain level down occurred, the test cleaning tape was run on the same recorder, and the same magnetic tape was immediately reproduced on the same recorder and the recovery of the level down was checked. The results are shown in Table 57 together with the compounds of various ligands applied to the cleaning tape.

compound Level Down Recovery (dB) G-1 4 G-2 4 G-3 3 G-4 4 G-5 3 G-6 4 G-7 4 G-8 4 G-9 3 H-1 3 Not added 0

As can be seen from Table 57, the level down was remarkably recovered when the magnetic tape was reproduced by the same video tape recorder as that in which the cleaning tape made of the nonwoven fabric impregnated with the ligand was running after the level down at the time of output became remarkable.

From the results of Experiments 16 to 18, it was found that a diketone compound (ligand) was suitable as a cleaning agent when added to a cleaning tape. When applied to the surface of the non-magnetic support or to the surface of the cleaning layer or to the cleaning layer of the cleaning tape, the ligand is effective to clean the recorder magnetic tape on which the tape travels.

As will be apparent from the above description, the use of a magnetic recording medium containing a compound having a pyridine skeleton and two or more ligand sites prevents the generation of combustion products in the magnetic head.

Even when the magnetic recording medium of the present invention is used and the recording time is prolonged for increasing the friction time or the scanning speed is increased, the combustible remains on the magnetic head, the spacing loss is reduced, and the increase of the error rate is prevented.

In the case of the coated magnetic layer, a coupling agent or carbonic acid may be added together with the ligand to improve the prevention effect on the combustible material. In the case of the deposition type magnetic layer, a carbon film is formed on the magnetic layer film to improve the prevention effect on the combustible material in the same way. The organic acid salt of the ligand is added to the coated magnetic layer to prevent the generation of combustibles in the magnetic head, thereby improving the steel durability.

Further, when a compound having a pyridine skeleton and two or more ligand sites is used as a cleaning agent for a cleaning tape, the combustible adhering to the magnetic head can be removed without abrading or damaging the magnetic head.

Claims (23)

An antistatic agent containing a compound having a pyridine skeleton and two or more ligand moieties is held on a nonmagnetic support, at least a magnetic layer is formed on the nonmagnetic support. The magnetic recording medium according to claim 1, wherein the compound is at least one compound selected from the following general formulas (1) to (4). In the formulas, R ¹ to R ^{4 each} represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group, And two adjacent pairs of the groups may together form an aromatic ring and X is selected from the group consisting of a hydroxyl, a Schiff base, an ester, a carboxylic acid, an alcohol, an amine, an amide, an imide and a heterocyclic aromatic containing polar group Is selected. Wherein R ⁵ to R ¹⁰ are each a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group, and an alkyl group, And two adjacent pairs of the groups may together form an aromatic ring, and Y is OH, SH or NH ₂ . Wherein R ¹¹ to R ¹⁸ are a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group substituted with the above- Group, and two adjacent pairs of the groups may form an aromatic ring together. Wherein R ¹⁹ to R ^{26 each} represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group, an aryl group and a heterocyclic aromatic group Group, and two adjacent pairs of the groups may form an aromatic ring together. The magnetic recording medium according to claim 2, wherein the magnetic layer is prepared by applying a magnetic paint comprising a magnetic powder and a binder as a main component on a medium, and the anti-sticking agent is applied to the surface of the magnetic layer or added to the magnetic layer. 4. The magnetic recording medium according to claim 3, wherein the titanate-based coupling agent is applied to the magnetic layer surface or added to the magnetic layer. The magnetic recording medium according to claim 4, wherein at least one of an amino group, a phosphate ester group, a carboxylic acid ester group, an acyl group, a hydroxyl group, a carbonyl group and an alkyl group is introduced into the titanate-based coupling agent. 4. The magnetic recording medium according to claim 3, wherein carbonic acid is applied to the surface of the magnetic layer or added to the magnetic layer. The magnetic recording medium according to claim 1, wherein the magnetic layer is prepared by coating a magnetic paint comprising a ferromagnetic powder and a binder as a main component on a medium, and the compound is a salt formed by forming a salt with an organic acid. The magnetic recording medium according to claim 7, wherein the compound is at least one compound selected from the group consisting of a bipyridine derivative of the following formula (5) and an organic acid salt of a phenanthrene derivative of the following formula (6). Wherein R ¹¹ to R ¹⁸ are a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group substituted with the above- And two adjacent pairs of the groups may form an aromatic ring together and R ^* is a group selected from a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group or a sulfonate group An aryl group substituted with an alkyl group, a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group or a sulfonate group, and an alkyl group coupled with a heterocyclic aromatic group. Wherein R ¹⁹ to R ^{26 each} represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group, an aryl group and a heterocyclic aromatic group And two adjacent pairs of the groups may form an aromatic ring together and R ^* is a group selected from a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group or a sulfonate group An aryl group substituted with an alkyl group, a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group or a sulfonate group, and an alkyl group coupled with a heterocyclic aromatic group. The magnetic recording medium according to claim 2, wherein the magnetic layer is made of a ferromagnetic metal thin film having a carbon film formed thereon, and the anti-adhesion agent is applied to the surface of the carbon film. The magnetic recording medium according to claim 2, wherein a lower layer is formed on the side of the non-magnetic support opposite to the magnetic layer forming side, and the anti-adhesion agent is applied to the lower layer surface or added to the lower layer. Magnetic recording medium on which at least a magnetic layer is formed on a nonmagnetic support body which holds an anti-adhesion agent containing a diketone compound. 12. The magnetic recording medium according to claim 11, wherein the compound is a compound represented by the following formula (7) or (8). In the formulas, R ²⁷ to R ^{29 each} represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group, . The magnetic recording medium according to claim 12, wherein the magnetic layer is prepared by coating a magnetic paint comprising a ferromagnetic powder and a binder as a main component on a medium, wherein an anti-adhesion agent containing a compound of the general formula (8) is applied to the surface of the magnetic layer, Magnetic recording medium. 13. The magnetic recording medium according to claim 12, wherein the magnetic layer is prepared by applying a magnetic paint comprising a magnetic powder and a binder as a main component on a medium, and a titanate coupling agent is applied to the surface of the magnetic layer or added to the magnetic layer. 15. The magnetic recording medium according to claim 14, wherein at least one of an amino group, a phosphate ester group, a carboxylic acid ester group, an acyl group, a hydroxyl group, a carbonyl group and an alkyl group is introduced into the titanate-based coupling agent. 13. The magnetic recording medium according to claim 12, wherein the magnetic layer is prepared by applying a magnetic paint containing a ferromagnetic powder and a binder as a main component on a medium, and the carboxylic acid is applied to the surface of the magnetic layer or added to the magnetic layer. The magnetic recording medium according to claim 12, wherein the magnetic layer is made of a ferromagnetic metal thin film having a carbon film formed thereon, and the anti-adhesion agent is applied to the surface of the carbon film. The magnetic recording medium according to claim 7, wherein the anti-adhesion agent comprises one or more phosphorus-containing compounds selected from the following formulas (9) to (12). In the formulas, R ³⁰ to R ^{32 each} represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group, . In the formulas, R ³³ to R ^{35 each} represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group, . In the formulas, R ³⁶ to R ³⁸ represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group, . In the formulas, R ³⁹ to R ^{41 each} represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group, . The magnetic recording medium according to claim 12, wherein a lower layer is formed on the side of the non-magnetic support opposite to the magnetic layer forming side, and the anti-adhesion agent is applied to the lower layer surface or added to the lower layer. A cleaning tape containing a compound having a pyridine skeleton and two or more ligand sites on a support. The cleaning tape according to claim 20, wherein the compound is at least one compound selected from the following formulas (13) to (16). In the formulas, R ¹ to R ^{4 each} represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group, And two adjacent pairs of the groups may together form an aromatic ring and X is selected from the group consisting of a hydroxyl, a Schiff base, an ester, a carboxylic acid, an alcohol, an amine, an amide, an imide and a heterocyclic aromatic containing polar group Is selected. Wherein R ⁵ to R ¹⁰ are each a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group, and an alkyl group, And two adjacent pairs of the groups may together form an aromatic ring, and Y is OH, SH or NH ₂ . Wherein R ¹¹ to R ¹⁸ are a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group substituted with the above- Group, and two adjacent pairs of the groups may form an aromatic ring together. Wherein R ¹⁹ to R ^{26 each} represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group, an aryl group and a heterocyclic aromatic group Group, and two adjacent pairs of the groups may form an aromatic ring together. A cleaning tape holding an antisticking agent containing a diketone compound on a support. 23. A cleaning tape according to claim 22, wherein said compound is a compound of formula (17) or (18). In the formulas, R ²⁷ to R ^{29 each} represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a carboxyl group, a carbonyl group, an amino group, an amide group, a sulfonate group and an alkyl group, .