JP2002352413A - Magnetic recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic recording medium that is excellent in runability and durability under any operating condition, and is prevented from head wear and degradation of magnetic property. SOLUTION: In a magnetic recording medium used in a state of sliding to the magneto-resistive reproducing head, this medium is provided with a lubricant layer containing at least one kind of a monoester monocarboxylic acid amine salt expressed as the following general formula (1) and the following general formula (2) on a magnetic layer, [where R<1> , R<3> , R<4> , R<5> , and R<6> in the general formula (1) and general formula (2) are a 6-30C aliphatic alkyl group, a 6-30C aliphatic alkenyl group, or hydrogen atom independently, respectively. R<2> is a 6-30C phloroalkyl group, or a 6-30C phloroalkenyl group].

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording medium such as a magnetic tape.

[0002]

2. Description of the Related Art Conventionally, as a magnetic recording medium, a magnetic coating comprising a ferromagnetic powder such as an oxide magnetic powder or an alloy magnetic powder, a binder, an organic solvent, etc. is applied to a non-magnetic support. A so-called coating type magnetic recording medium in which a layer is formed is widely used.

On the other hand, a ferromagnetic metal material is directly deposited on a non-magnetic support such as a polyester film or a polyamide film by a vacuum thin film forming technique such as a vacuum evaporation method, a sputtering method, or an ion plating method, or by plating. A magnetic recording medium of a so-called ferromagnetic metal thin film type, in which a magnetic layer is formed by being applied, has been used with an increasing demand for high-density recording and long-time recording. Such a ferromagnetic metal thin film type magnetic recording medium is a consumer video format (8 mm Hi-8 format,
DV format) or professional video format (DVCA)
M) and the like.

[0004] A magnetic recording medium of the ferromagnetic metal thin film type is superior in magnetic properties such as coercive force and squareness ratio to a coating type magnetic recording medium, and is superior in electromagnetic conversion characteristics in a short wavelength region. Further, the magnetic recording medium of the ferromagnetic metal thin film type has a very small thickness of the magnetic layer, so that recording demagnetization and thickness loss at the time of reproduction are extremely small, and a nonmagnetic material such as an organic binder is contained in the magnetic layer. Since there is no need to mix a binder, there are many advantages such as a high packing density of the magnetic material.

[0005] In recent years, the size of magnetic recording / reproducing apparatuses has been reduced. Along with this, magnetic recording media used in miniaturized magnetic recording / reproducing devices are required to achieve a high recording capacity while at the same time miniaturizing the shape. Has been requested.

Japanese Patent Application Laid-Open No. H11-203652 discloses a magnetic recording medium compatible with such high-density recording, which has a high reproducing sensitivity and is suitable for high-frequency recording and suitable for high-density recording. , MR head) is disclosed. A ferromagnetic metal thin film type magnetic recording medium having a magnetic layer optimized for reproduction by a helical scan method using a helical scan method is disclosed.

In general, the magnetic recording medium always contacts the magnetic head while traveling at a high speed when traveling with a helical scan type magnetic recording / reproducing apparatus. Therefore, the magnetic recording medium is subject to wear and damage due to contact with the magnetic head. Very susceptible. Therefore, in a magnetic recording medium of a ferromagnetic metal thin film type, a protective film made of carbon or the like, a lubricant layer, and the like are formed on a magnetic layer to improve running properties and durability.

[0008]

However, the protective film or lubricant formed for the purpose of realizing good running performance and durability is shaved by the magnetic head during running, and the shaved protective film and lubricating oil are removed. The shavings of the agent, so-called powder dropping, may occur. When this powder drop accumulates, spacing occurs between the magnetic recording medium and the magnetic head,
There is a problem that a predetermined signal output cannot be obtained. Further, there is a problem that the magnetic head is worn due to the contact between the magnetic film and the portion where the protective film or the lubricant has been removed.

In recent years, in a magnetic recording medium of the ferromagnetic metal thin film type, the surface smoothness of a magnetic layer is reduced by a surface smoothing treatment such as a super calendering treatment in order to reduce spacing loss and improve electromagnetic conversion characteristics. It has been improved. However, if the surface smoothness of the magnetic layer is extremely good, the substantial contact area with the magnetic head increases, and the coefficient of friction with the magnetic head tends to be higher. Further, as the recording time increases, the sliding time with the magnetic head becomes longer, and the scanning speed tends to become faster. However, these tendencies promote the occurrence of powder drop.

For example, Japanese Patent Application Laid-Open Publication No. 11-203652 discloses that a magnetic layer optimized according to the characteristics of an MR head is provided, and a perfluoropolyether or the like is used as a lubricant so that a good condition can be obtained under any use conditions. A magnetic recording medium exhibiting a lubricating effect is disclosed. However, when perfluoropolyether was used as a lubricant, powder dropping could not be sufficiently prevented, and as a result, the level was reduced and the head was worn.

Therefore, in the field of magnetic recording, the magnetic head is generally physically polished using a so-called cleaning tape in order to remove powder dropout accumulated on the magnetic head. However, when the magnetic head is polished by a physical method, if the polishing force is too high, the magnetic head may be polished more than necessary, which may degrade the characteristics of the magnetic head.

In particular, the characteristics of an MR head and an inductive type thin film magnetic head mainly composed of a metal thin film formed by a thin film forming technique are liable to be remarkably deteriorated due to wear. For this reason, for a magnetic head formed by a thin film forming technique, for example, an MR head, a cleaning tape cannot be used to remove powder dust accumulated in the MR head, that is, powder dust is accumulated in the MR head. If so, there is no way to remove this powder drop. Therefore, it is necessary to design a lubricant in which the occurrence of powder dropping itself is prevented.

The present invention has been proposed in view of such conventional circumstances, and has as its object to provide good running and durability under any use conditions, and to reduce head wear and magnetic characteristics. An object of the present invention is to provide a magnetic recording medium in which deterioration is prevented.

[0014]

That is, the present invention relates to a magnetic recording medium used in a sliding state with respect to a magnetoresistive read head, wherein the following general formulas (1) and (2) are formed on a magnetic layer. The present invention relates to a magnetic recording medium provided with a lubricant layer containing at least one of the monoester monocarboxylic acid amine salts represented by the formula (1).

Embedded image [However, in the general formula (1) and the general formula (2), R ¹ , R ³ , R ⁴ , R ⁵ and R ⁶ are each independently:
A C 6-30 aliphatic alkyl group, a C 6-30 aliphatic alkenyl group or a hydrogen atom, and R ² is a C 6-30 fluoroalkyl group or a C 6-30 fluoroalkenyl group. is there. ]

The "sliding state" means that when only the magnetoresistive head is sliding, only the magnetic recording medium of the present invention slides with respect to the magnetoresistive head. Or both are sliding.

According to the present invention, at least one of the monoester monocarboxylic acid amine salts represented by the general formulas (1) and (2) is used as the lubricant, Excellent lubricity over a long period of time, and also prevents the occurrence of powder drop, thereby reducing output loss and deterioration of head characteristics without causing spacing loss and head wear. Becomes

Further, by using the magnetoresistive effect reproducing head (hereinafter referred to as MR head) in a sliding state, the above-mentioned remarkable improvement effect (such as prevention of powder dropping) can be obtained. This is advantageous for the specific performance (high reproduction sensitivity, etc.) of the MR head.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described more specifically based on embodiments.

The magnetic recording medium according to the present invention is characterized in that the MR
Used in a helical scan magnetic recording system using a head, a ferromagnetic metal thin film as the magnetic layer, a protective film, and the lubricant layer are formed on a non-magnetic support, and the lubricant layer is formed by the general formula ( It is preferable that the lubricant is formed by applying a lubricant paint obtained by dissolving the lubricant containing at least one of 1) and the general formula (2) in a solvent or by a physical film forming method. .

The MR head is hardly affected by noise and can improve the reading accuracy. Therefore, even if a large amount of data is written in a unit area, it can be read correctly, and the recording density can be increased. That is, the M
The R head has good reproduction sensitivity, and is suitable for high-density recording for high frequency use, for example. Further, the helical scan magnetic recording system records data obliquely when viewed from the length direction of the magnetic recording medium, so that it is possible to easily increase the capacity and further reduce the size.

As the physical film forming method, a vacuum evaporation method, a sputtering method or a pulse laser deposition method can be applied as described later. If the lubricant layer is formed by the physical film forming method, for example, it is possible to effectively prevent so-called dry spots, which occur when the lubricant is deposited in an island shape after drying, and a sudden level reduction occurs. It can have better durability and running properties under any use conditions without causing sticking of a tape or the like to the running guide.

In addition, since dust and the like can be effectively prevented from adhering, the occurrence of dropout can be suppressed,
Since no solvent is used, safety and environmental preservation are further improved.

The vacuum evaporation method has good film-forming properties and is easy to operate. The sputtering method can be easily produced, has high productivity, and has good film-forming properties. In the pulse laser deposition method, control in film formation is easy and film formability is good.

As described above, in the monoester monocarboxylic acid amine salts represented by the general formulas (1) and (2) as constituent materials of the lubricant layer, R
¹ , R ³ , R ⁴ , R ⁵ and R ⁶ are each independently a hydrogen atom or an aliphatic alkyl group having 6 to 30 carbon atoms, more preferably 10 to 21 or 6 to 30, more preferably 1
0 to 21 is an aliphatic alkenyl group, and R ² is a fluoroalkyl group having 6 to 30, more preferably 6 to 21 carbon atoms or a fluoroalkenyl group having 6 to 30 carbon atoms, more preferably 6 to 21 carbon atoms. is there. By specifying R ¹ , R ² , R ³ , R ⁴ , R ^5, and R ⁶ as described above, for example, the solubility of the lubricant in the solvent becomes better, the friction coefficient lowering effect, and the wear characteristics are improved. And the durability is further improved.

R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ^{6 in} the monoester monocarboxylic acid amine salt represented by the general formula (1) and the general formula (2) have carbon atoms If it is less than 6, the length of the group is too short, so that a decrease in the coefficient of friction or an improvement in the friction characteristics and durability cannot be achieved. It becomes difficult to form a lubricant layer.

As the above fluoroalkyl group, -C ₂ H _{4
C 8 F 17, -C 2 H} 4 C 6 F 13, -C 6 H 12 C 4 F 8 CF (C
_{F 3) 2, -CH 2 C} 4 F 8 CF (CF 3) 2 and the like,
As the Furoroarukeniru group, -CH ₂ CH = CH
C ₆ F _13, etc. -CH ₂ CH = CHC ₈ F _17. Examples of the aliphatic alkyl _{group, -CH 2 CH (C 7 H} 15)
C ₉ H ₁₉ , —C ₁₂ H _{25 and the} like, and the aliphatic alkenyl group include —C ₆ H ₁₂ CH ＝ CHC ₈ H _{17 and the} like.

The amine is a primary amine,
Secondary amines and tertiary amines can be used, and quaternary ammonium compounds can also be used. The structure of the amine that can be used is also arbitrary, and can be arbitrarily selected regardless of the branched structure, isomer structure, alicyclic structure, molecular weight, presence or absence of an unsaturated bond, and the like. However, the amine preferably has an alkyl group. In particular, when the amine has an alkyl group having 6 or more carbon atoms, excellent lubricity can be maintained for a longer period of time, and powder generation can be prevented. It can be prevented more. Therefore, it is possible to further reduce output reduction and deterioration of head characteristics without causing spacing loss and head wear.

The magnetic recording medium according to the present invention uses at least one of the monoester monocarboxylic acid amine salts represented by the general formulas (1) and (2) as the lubricant. It is possible to maintain excellent lubricity for a longer period of time, and further prevent the occurrence of powder dropping, so as not to cause spacing loss and head wear, to reduce output and to reduce head characteristics. Deterioration can be further reduced.

Incidentally, the lubricant layer is formed of the general formula (1)
In addition to containing at least one kind of the monoester monocarboxylic acid amine salt represented by the general formula (2), a conventionally known lubricant may be appropriately combined and contained.

Further, the lubricant layer may contain a rust preventive, and in this case, it is preferable to add the rust preventive to the lubricant paint. As the rust preventive, known materials and the like which are usually used as a rust preventive for this type of magnetic recording medium can be used. Specifically, for example, phenols,
Naphthols, quinones, heterocyclic compounds containing a nitrogen atom, heterocyclic compounds containing an oxygen atom, heterocyclic compounds containing a sulfur atom, and the like can be used.

Furthermore, a layer made of the rust preventive may be formed between the protective film and the lubricant layer without including the rust preventive in the lubricant layer. By forming the rust preventive layer and the lubricant layer separately in two layers, the rust preventive effect and the lubricating effect can be further improved.

The amount of the lubricant coating applied was 0.1 mg /
m ^{2 to} 100 mg / m ² , preferably 0.5 m
and more preferably ^{g / m 2 ~50mg / m 2} . If the amount of the lubricant coating is too small, the effects of lowering the coefficient of friction, improving abrasion resistance and durability may not be sufficiently exhibited. On the other hand, if the amount of the lubricant coating applied is too large, a shearing phenomenon may occur between the sliding member and the magnetic layer, resulting in poor running performance.

FIG. 1 is a schematic sectional view showing a magnetic recording medium according to the present invention.

In the magnetic recording medium according to the present invention, as shown in FIG. 1, a metal magnetic thin film made of a ferromagnetic metal material as a magnetic layer 3 is formed on one main surface of a nonmagnetic support 2 by, for example, a vacuum evaporation method. The protective layer 4 is formed by a vacuum thin film forming technique such as an ion plating method and a sputtering method.
D) or a chemical vapor deposition method (CVD method), and the lubricant layer 5 is preferably formed on the protective film 4.

As the non-magnetic support 2, any one can be used as long as it is used as a non-magnetic support in an ordinary magnetic recording medium. Specifically, polyesters such as polyethylene terephthalate and polyethylene naphthalate; Polyolefins such as polyethylene and polypropylene; cellulose derivatives such as cellulose triacetate and cellulose diacetate; vinyl resins such as polyvinyl chloride and polyvinylidene chloride; plastics such as polycarbonate, polyimide, polyamide and polyamide imide; aluminum alloys and titanium alloys And other light metals, and ceramics such as glass.

When a rigid material such as an aluminum alloy plate or a glass plate is used as the non-magnetic support 2, the surface of the non-magnetic support 2 is subjected to an alumite treatment or the like to form an oxide film, a Ni—P film, or the like. It may be formed so that the surface of the nonmagnetic support 2 is hardened.

The non-magnetic support 2 may be in any form such as a film, a sheet, a disk, a card, and a drum.

Further, at least one kind of projections among mountain-like projections, wrinkle-like projections, and granular projections is formed on the surface of the nonmagnetic support 2, and those having a controlled surface roughness can also be used.

In the magnetic recording medium 1, the surface property of the magnetic layer 3 can be controlled by forming at least one of the mountain-like projections, the wrinkle-like projections, and the granular projections on the non-magnetic support 2. However, by combining at least two or more of these projections, the effect is increased. In particular, when the wrinkled projections and the granular projections are formed on the nonmagnetic support 2 on which the mountain-shaped projections are formed, durability and running are improved. The properties are significantly improved. In this case, the overall height of the protrusion is
The density is preferably in the range of 10 to 200 nm, and the density is preferably 1 × 10 ⁵ to 1 × 10 ⁷ / mm ² .

The ridges are formed by adding inorganic fine particles having a particle size of about 50 to 300 nm into the non-magnetic support 2 when the non-magnetic support 2 is formed. The height of the ridge is 10 to 100 from the nonmagnetic support 2.
nm, and the density of the peaks is 1 ×
It is preferably 10 ⁴ to 1 × 10 ⁵ / mm ² . Calcium carbonate, silica, alumina, or the like can be used as the inorganic fine particles to be internally added to the nonmagnetic support 2 when forming the mountain-shaped protrusions.

The wrinkled protrusions are formed by applying a dilute solution of a resin using a specific mixed solvent on the non-magnetic support 2 and drying it. The height of the wrinkle-like projection is preferably 0.01 to 1 μm, and 0.03 to 1 μm.
More preferably, it is 0.5 μm. The shortest interval between the wrinkle-like projections is preferably 0.1 to 20 μm.

Examples of the resin for forming the wrinkle-like projections include polyester such as polyethylene terephthalate and polyethylene naphthalate, polyamide, polystyrene, polycarbonate, polyacrylate, polysulfone, polyvinyl chloride, polyvinylidene chloride, polyvinyl butyral, and the like. A simple substance, a mixture or a copolymer such as polyphenylene oxide and phenoxy resin can be used, and those having a soluble solvent are suitable.

Then, in a solution obtained by dissolving these resins in a good solvent at a resin concentration of 1 to 1000 ppm, a solvent which is a poor solvent of the resin and has a higher boiling point than the good solvent is added to the resin by 10 to 100%. By applying the double-added solution to the surface of the nonmagnetic support 2 and drying it, a thin layer having the very fine wrinkle-like projections can be formed.

The granular protrusions can be formed by adhering organic ultrafine particles such as an acrylic resin or inorganic fine particles such as silica or metal powder onto the non-magnetic support 2 in a spherical or hemispherical shape. The height of the granular projections is 5 to 50.
nm, and the density of the granular projections is 1 ×
It is preferably from 10 ^{6 to} 5 × 10 ⁷ pieces / mm ² .

The method for forming the magnetic layer 3 is not particularly limited, but is a so-called physical vapor deposition (PVD) method such as plating, sputtering, or vacuum deposition.
Is preferably formed by directly applying a ferromagnetic metal material on the nonmagnetic support 2, that is, the metal magnetic thin film made of the ferromagnetic metal material. The thickness of the magnetic layer 3 formed by such a technique is preferably 0.01 to 1 μm.

Examples of the ferromagnetic metal material for forming the magnetic layer 3 include metals such as Fe, Co, and Ni, Co—Ni alloys, Co—Pt alloys, Co—Pt—Ni alloys,
-Co-based alloy, Fe-Ni-based alloy, Fe-Co-Ni-based alloy, Fe-Ni-B-based alloy, Fe-Co-B-based alloy,
Fe-CO-Ni-B-based alloys, Co-Cr-based alloys, or alloys containing metals such as Pt and Al can be used.

The metal magnetic thin film includes an in-plane magnetized film and a perpendicular magnetized film. In particular, when a Co—Cr alloy is used, the perpendicular magnetized film can be formed.

When the in-plane magnetic film is formed, Bi, Sb, Pb, Sn, Ga, In, G
It is preferable to previously form an underlayer made of a low-melting non-magnetic material such as e, Si, or Tl. When the metal magnetic material described above is vapor-deposited or sputtered from a direction perpendicular to the nonmagnetic support 2 to form the metal magnetic thin film, these low-melting nonmagnetic materials are diffused to orient the metal magnetic thin film. As a result, the in-plane isotropy is ensured and the coercivity is improved.

When the magnetic layer 3 is formed by a vacuum evaporation method, the ferromagnetic metal material is evaporated under a vacuum of 1 × 10 ⁻⁶ to 1 × 10 ⁻² Pa by resistance heating, high frequency heating, electron beam heating, or the like. As a result, the evaporated metal (ferromagnetic metal material) can be deposited on the non-magnetic support 2. In the vacuum deposition method, the nonmagnetic support 2 is generally used to obtain a high coercive force.
An oblique deposition method for obliquely depositing the ferromagnetic metal material is used. Furthermore, vacuum deposition may be performed in an oxygen atmosphere to obtain a higher coercive force.

When the magnetic layer 3 is formed by the ion plating method, which is a kind of the physical film forming method, the magnetic layer 3 is formed in an inert gas atmosphere of 1 × 10 ^-2 to 1 × 10 ^-1 Pa. A glow discharge or an RF glow discharge is caused, the ferromagnetic metal material is evaporated during the discharge, and the evaporated metal (ferromagnetic metal material) can be deposited on the nonmagnetic support 2.

Further, when the magnetic layer 3 is formed by the above-mentioned sputtering method, glow discharge is caused in an atmosphere containing argon gas of 0.1 to 10 Pa as a main component, and the generated argon gas ions strike out atoms on the target surface. The atoms can be deposited on the non-magnetic support 2. Specific examples of the sputtering method include a DC two-pole, three-pole sputtering method, a high-frequency sputtering method, and a magnetron sputtering method using magnetron discharge.

The protective film 4 is formed, for example, by depositing carbon on the magnetic layer 3 by chemical vapor deposition (CVD).
ion) or a physical film forming method such as sputtering (PVD: Physica
l Vapor Deposition). The thickness of the protective film 4 is preferably 2 to 100 nm, more preferably 5 to 30 nm.
If the thickness of the protective film 4 is less than 2 nm, the durability of the protective film 4 may be insufficient. On the other hand, if the thickness of the protective film 4 exceeds 100 nm, sufficient output may not be obtained when performing short-wavelength recording.

When the protective film 4 is formed by the CVD method, first, a hydrocarbon gas or a mixed gas of a hydrocarbon gas and an inert gas is introduced into a vacuum vessel.
The protective film 4 can be formed on the magnetic layer 3 by discharging in a vacuum vessel while maintaining the pressure at about 100 Pa to generate plasma of hydrocarbon gas. The discharge type may be either an external electrode type or an internal electrode type, and the discharge frequency can be experimentally determined. Further, by applying a voltage of 0 to -3 kV to the electrode disposed on the nonmagnetic support 2 side on which the magnetic layer 3 is formed, the hardness of the protective film 4 can be increased and the adhesion can be improved. .

The hydrocarbon gas used as the material of the protective film 4 includes methane, ethane, propane, butane, pentane, hexane, heptane, octane, ethylene, acetylene,
Propene, butene, pentene, benzene and the like can be used.

Next, a method for forming the lubricant layer 5 will be described.

The lubricant layer 5 is formed by dissolving a lubricant containing at least one of the general formulas (1) and (2) on a protective film 4 in a solvent. It is desirable to apply the coating material or to form by the physical film forming method.

When the lubricant layer 5 is formed by coating, a lubricant containing at least one of the monoester monocarboxylic acid amine salts represented by the general formulas (1) and (2) is used. The lubricant coating is preferably prepared by dissolving the lubricant coating in a solvent.
The lubricant layer 5 can be formed by applying it on the upper surface.

As the solvent, any of a fluorine-based solvent and a hydrocarbon-based solvent such as toluene or acetone can be used. Here, the conventionally known fluorine-containing lubricant is dissolved only in the fluorine-based solvent, whereas the fluorine-containing lubricant is represented by the general formula (1) or the general formula (2) used for the magnetic recording medium according to the present invention. The monoester monocarboxylic acid amine salt can be dissolved not only in a fluorine-based solvent but also in a hydrocarbon-based solvent such as toluene and acetone. That is, as a solvent for the lubricant coating, a hydrocarbon-based solvent having a very small effect on the environment as compared with a fluorine-based solvent can be used.

FIG. 2 shows a lubricant containing at least one of the monoester monocarboxylic acid amine salts represented by the general formulas (1) and (2) on the protective film. FIG. 4 is a schematic cross-sectional view showing an example of a case where the lubricant paint obtained by dissolving and preparing the lubricant paint is formed by applying, for example, a gravure roll coating method among coating methods.

In this apparatus, the base film 6 is guided via a guide roller 7 by a drive source (not shown), and runs between the backup roll 8 and the gravure roll 36.

The gravure roll 36 is partially immersed in the lubricant paint 11 filled in the paint tank 31, and the lubricant paint 11 attached to the circumferential surface of the gravure roll 36 by the rotation of the gravure roll 36 is Excess paint is scraped off by the doctor blade 12 and applied to one surface of the base film 6 (on the protective film).

The base film 6 'having one surface coated with the lubricant paint 11 is guided via a guide roller 13 and wound around a winding hub (not shown).

The lubricant layer 5 formed by the above-described coating method is used.
The lubricant layer 5 can be formed by a physical film forming method such as the vacuum evaporation method other than the formation of the lubricant layer 5. FIG.
FIG. 1 is a schematic cross-sectional view showing an example of a manufacturing apparatus that can be suitably used for forming a lubricant layer 5 by the physical film forming method in manufacturing a magnetic recording medium according to the present invention.

A conventional vacuum evaporation apparatus using a rotary pump has an oil bag or the like in the chamber, and as a result, the inside of the chamber may be contaminated with oil mist or the like. In manufacturing, a dry pump 37 is preferably used in a manufacturing apparatus that can be suitably used for forming the lubricant layer 5, and thus a cleaner vacuum can be created. Further, by providing the conductance valve 33, an arbitrary pressure can be set.

First, for example, a lubricant 29 containing at least one of the monoester monocarboxylic acid amine salts represented by the general formulas (1) and (2) is supplied to a heating mechanism (heating power supply 20). ). By heating this in a vacuum of about 2 × 10 ^{0 to} 5 × 10 ² Pa, lubricant vapor can be generated, and a lubricant layer can be formed on the protective film. The heating method is induction heating,
Any of resistance heating may be used. In addition, a bombard chamber 19 may be provided, and if necessary, bombardment with an inert gas may be performed before forming a lubricant layer to activate the surface of the processing raw material to increase the adsorption force of the lubricant 29. .

When the lubricant layer 5 is formed by the vacuum deposition method, the sputtering method, or the pulse laser deposition method as the physical film forming method, for example, the lubricant is deposited in the form of islands after drying. It can effectively prevent the occurrence of so-called dry spots, without causing sudden level down or sticking of tape etc. to the traveling guide, more excellent durability under any use conditions,
It can have runnability.

Further, if the lubricant layer is formed by the physical film forming method, it is possible to prevent the medium from coming into contact with the air and effectively prevent dust and the like from adhering. Since it can be suppressed and no solvent is used, safety and environmental preservation are further improved.

Regardless of the method of the coating method or the physical film forming method, the magnetic recording medium according to the present invention provides:
As at least one of the monoester monocarboxylic acid amine salts represented by the general formulas (1) and (2) is used as the lubricant, excellent lubricity is maintained for a longer time. In addition, since the occurrence of powder dropping can be further prevented, it is possible to further reduce the reduction in output and the deterioration of head characteristics without causing spacing loss and head wear.

Also, the magnetic recording medium 1 according to the present invention
On the other main surface of the non-magnetic support 2 opposite to the one main surface on which the magnetic layer 3 is formed, a support reinforcing layer (not shown) or a back coat layer (not shown) can be formed.

The support reinforcing layer is made of Mg, Al, Si, T
i, V, Cr, Fe, Co, Ni, Cu, Zn, Ge,
Metals such as Zr, Nb, Mo, W, and alloys of these metals;
It is preferably an oxide. As a method for forming the support reinforcing layer, a film forming method such as a vacuum evaporation method, a sputtering method, and an ion plating method can be applied, and the thickness of the support reinforcing layer is preferably 20 nm to 500 nm.

The back coat layer can be formed by applying a back coat layer paint in which a powder component and a binder are mixed and dispersed in an organic solvent on the non-magnetic support 2.

Examples of the powder component include carbon black for imparting conductivity and inorganic powder added for controlling surface roughness and improving durability.

As the carbon black, two kinds of carbon blacks having different average particle diameters, specifically, fine carbon black having an average particle diameter of 10 to 20 nm,
It is preferable to use a mixture of coarse carbon black having an average particle diameter of 230 to 300 nm.

When the particulate carbon black is added to the back coat layer, the surface electric resistance of the back coat layer is reduced, and the light transmittance can be reduced. There are many magnetic recording medium recording / reproducing devices that use the light transmittance of a tape for operation signals. The addition of the particulate carbon black to such an apparatus is particularly effective. Further, since the particulate carbon black is excellent in holding force of the lubricant, when a lubricant is added to the back coat layer, it can contribute to reduction of a friction coefficient.

When the coarse particle carbon black is added to the back coat layer, fine projections are formed on the surface of the back coat layer, so that the coarse particle carbon black functions as a solid lubricant, The area of contact with the metal can be reduced, and the coefficient of friction can be reduced.

As described above, when two types of carbon blacks having different average particle diameters are added to the back coat layer, the addition ratio (weight ratio) of the fine carbon black to the coarse carbon black is 98. : 2 to 7
5:25, preferably 95: 5 to 85:15
Is more preferable. The amount of carbon black added to the back coat layer (or the total amount in the case where the fine particle carbon black and the coarse particle carbon black are mixed and added) is 100 parts by weight of a binder described later. Is preferably 30 to 80 parts by weight, more preferably 45 to 65 parts by weight.

The fine carbon black particles include:
Specifically, RAVEN20 manufactured by Columbia Carbon Co., Ltd.
00B (average particle diameter 18 nm), RAVEN 1500
B (17 nm), Cabot BP800 (1
7 nm), PRINTEX 90 (14 n) manufactured by Degussa
m), PRINTEX95 (15 nm), PRI
NTEX85 (16 nm), PRINTEX75
(17 nm), # 3950 manufactured by Mitsubishi Kasei Kogyo Co., Ltd.
(16 nm).

As specific examples of the coarse-grained carbon black, thermal black (average particle diameter: 270 nm) manufactured by Khancarb and Raven MTP (275 nm) manufactured by Columbia Carbon Co., Ltd. can be used.

On the other hand, as the inorganic powder contained in the back coat layer, it is preferable to use calcium carbonate, inorganic powder having a Mohs hardness of 5 to 9, and the like. When the inorganic powder having a Mohs hardness of 5 to 9 is added to the back coat layer together with, for example, calcium carbonate or the above-described carbon black, the filler effect makes it difficult for the back coat layer to be repeatedly deteriorated even in sliding, and has a high strength. It becomes a coat layer.

When the back coat layer contains the inorganic powder having a Mohs hardness of 5 to 9, an appropriate polishing force is generated on the surface of the back coat layer, and adhesion to a tape guide pole or the like is reduced. In particular, when the inorganic powder and the calcium carbonate are used in combination, the sliding characteristics of the magnetic recording medium 1 with respect to the guide pole having a rough surface are improved, and the friction coefficient of the back coat layer is stabilized.

The inorganic powder having a Mohs hardness of 5 to 9 preferably has an average particle size of 80 to 250 nm.
It is more preferable that the thickness be 00 to 210 nm. The amount of the inorganic powder having a Mohs' hardness of 5 to 9 is preferably 3 to 30 parts by weight, more preferably 3 to 20 parts by weight, based on 100 parts by weight of the carbon black.

As the inorganic powder having a Mohs hardness of 5 to 9, for example, α-iron oxide, α-alumina or chromium oxide can be used. Of these, the α-iron oxide or the α-alumina is used. It is preferred to use. The inorganic powders having Mohs hardness of 5 to 9 may be added alone or in combination.

As the binder contained in the back coat layer, for example, a thermoplastic resin, a thermosetting resin, a reactive resin, or a mixture thereof can be used.

As the thermoplastic resin, vinyl chloride,
Polymer containing vinyl acetate, vinyl alcohol, maleic acid, acrylic acid, acrylic acid ester, vinylidene chloride, acrylonitrile, methacrylic acid, methacrylic acid ester, styrene, butadiene, ethylene, vinyl butyral, vinyl acetal, vinyl ether and the like as constituent units or Copolymers can be used.

Examples of the copolymer include a vinyl chloride-vinyl acetate copolymer, a vinyl chloride-vinylidene chloride copolymer, a vinyl chloride-acrylonitrile copolymer, an acrylate-acrylonitrile copolymer, and an acrylate ester. Vinylidene chloride copolymer, acrylate-styrene copolymer, methacrylate-acrylonitrile copolymer, methacrylate-vinyl chloride copolymer, methacrylate-styrene copolymer, vinylidene chloride-acrylonitrile Copolymers, butadiene-acrylonitrile copolymers, styrene-butadiene copolymers, chlorovinyl ether-acrylate copolymers and the like can be used. Further, polyamide resins, cellulose resins such as cellulose acetate butyrate and cellulose diacetate, cellulose propionate and nitrocellulose, polyvinyl fluoride, polyester resins, polyurethane resins, and various rubber resins can also be used.

Examples of the thermosetting resin or the reactive resin include a phenol resin, an epoxy resin, a polyurethane curable resin, a urea resin, a melamine resin, an alkyd resin, an acryl-based reactive resin, a formaldehyde resin, a silicone resin, and an epoxy resin. A polyamide resin, a mixture of a polyester resin and a polyisocyanate prepolymer, a mixture of a polyester polyol and a polyisocyanate, and a mixture of a polyurethane and a polyisocyanate can be used.

Examples of the organic solvent for the backcoat layer paint include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; and esters such as methyl acetate, ethyl acetate, butyl acetate, ethyl lactate, and glycol monoethyl ether acetate. Solvents, glycol dimethyl ether, glycol monoethyl ether, glycol ether solvents such as dioxane, aromatic hydrocarbon solvents such as benzene, toluene and xylene, aliphatic hydrocarbon solvents such as hexane and heptane, methylene chloride, ethylene chloride And chlorinated hydrocarbon solvents such as carbon tetrachloride, chloroform, ethylene chlorohydrin, and dichlorobenzene.

Further, a lubricant can be used in combination with the back coat layer. In this case, there is a method of internally adding a lubricant to the back coat layer, or a method of retaining the lubricant on the back coat layer. As the lubricant, any of conventionally known lubricants such as fatty acids, fatty acid esters, fatty acid amides, metal soaps, aliphatic alcohols, and silicone-based lubricants can be used.

FIG. 4 is a cross-sectional view of a main part of the MR head 50 in which the magnetic recording medium according to the present invention can be suitably used.

The MR head 50 includes a non-magnetic layer 22, a lower core 23, a non-magnetic gap layer 2 on a glass substrate 21.
4 are stacked in this order, and an MR film (magnetoresistive film) 10 connected to the lead electrodes 25A and 25B is formed thereon. Then, a bias medium 27 is disposed above the MR film 10 and the bias medium 27 is covered with an insulating layer 26 to constitute a read head 30.

A recording head 40 is formed above the reproducing head 30. The recording head 40 is a common core 28 common to the reproducing head 30 and the recording head 40 (the upper core of the reproducing head 30 and the recording head 40). A recording conductor coil 44 is provided on the lower layer core 40 via a recording gap material 49 (actually, further provided via a flattening film (interlayer insulating film) 45A). 44 is covered with a flattening film (interlayer insulating film) 45B, and an upper core 46 is further deposited thereon to form a recording gap on the medium facing surface 9.

As described above, the common core 28 is used as a common core for both heads, and the recording head 40 uses the common core 28 as one magnetic pole and the other as the write core 46.
Are arranged in the track direction of the magnetic recording medium 1 together with the reproducing head 30, and the MR head 50 as a composite head is
Is configured.

The magnetic recording medium according to the present invention is characterized in that
By using the head in a sliding state, the MR
It is possible to obtain a further remarkable improvement effect particularly preferable for the head (a sudden level reduction, prevention of sticking of a tape or the like to the traveling guide, etc.).

[0094]

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

First, a monoester monocarboxylic acid amine salt as a lubricant was synthesized as shown below.

<Synthesis of Monoester Monocarboxylic Acid as Raw Material> First, 9-decen-1-ol (CH ₂ ＣC
15.6 g of H (CH ₂ ) ₈ OH) and 54.6 g of perfluorooctyl iodide (F (CF ₂ ) ₈ I) were put in a flask, and nitrogen bubble was carried out.

Next, AIBN (2,2'-Azobis-isobutyr
Onitrile) was added, and the mixture was heated to reflux and reacted for 8 hours. After completion of the reaction, the raw materials were distilled off under reduced pressure, and as a residue, F (CF ₂ ) ₈ CH ₂ CHI (CH ₂ ) ₈
56 g of OH were obtained.

Then, 56 g of F obtained as a residue were obtained.
(CF ₂ ) ₈ CH ₂ CHI (CH ₂ ) ₈ OH was dissolved in 400 cc of ethanol, and 40 cc of concentrated hydrochloric acid was added thereto, followed by heating. Then, 6 g of zinc powder was added little by little, and the mixture was refluxed for 2 hours. Further, 20 cc of concentrated sulfuric acid was added, and the mixture was refluxed for 1 hour. After completion of the reaction, the solution was filtered while it was still hot, and the obtained filtrate was concentrated.

Next, 200 cc of a 10% aqueous sodium hydroxide solution was added to the concentrated filtrate, followed by stirring to obtain a precipitate. Then, by filtering and drying this precipitate,
37 g of F (CF ₂ ) ₈ CH ₂ CH ₂ (CH ₂ ) ₈ OH was obtained.

Then, 37 g of F (CF ₂ ) ₈ CH ₂ CH ₂
(CH ₂ ) ₈ OH and isooctadecyl succinic anhydride 45
g) was dissolved in 400 cc of toluene, concentrated sulfuric acid was added in a catalytic amount, and the mixture was refluxed for 3 hours.

Next, after allowing to cool, the reaction solution was washed with water, dried by adding magnesium sulfate, and concentrated. After removing the raw material by column chromatography (silica gel / toluene), the eluent was changed to ethyl acetate, and the desired product was collected. Finally, by concentrating the ethyl acetate solution, alkyl succinate monoester monocarboxylic acid as monoester monocarboxylic acid, that is, C ₉ H ₁₉ CH (C ₇ H ₁₅ )
The _{CH 2 CH (COOH) CH 2} COOC 10 H 20 C 8 F 17 to give 47 g.

<Monoester Monocarboxylic Acid Amine Salt
Synthesis> Alkyl monosuccinate obtained as described above
Ester monocarboxylic acid (C ₉H₁₉CH (C₇H₁₅) CH
_TwoCH (COOH) CH_TwoCOOC_TenH₂₀C₈F₁₇Circle)
Transfer to a bottom flask and add 5.9 g of n-heptylamine.
And heated to 50 ° C. After stirring thoroughly to make it uniform,
Cool to form monoester monocarboxylic acid amine salt
Alkyl succinate monoester monocarboxylate amine
Salt, ie C₉H₁₉CH (C₇H₁₅) CH_TwoCH (COO^-N
⁺H_TwoC₇H₁₅) CH_TwoCOOC_TenH₂₀C₈F ₁₇52g
Was. Alkyl succinate monoester mono obtained here
The carboxylic acid amine salt is referred to as Compound 1.

Then, 14 kinds of compounds 1 to 14 were respectively synthesized by the same method as described above except that the raw materials were changed. The monoester monocarboxylic acids that are the raw materials for the synthesis of Compounds 1 to 14 are also shown in Table 1 below. Further, R ³ , R ⁴ , R ⁵ in Compounds 1 to 14
And R ⁶ are also shown in Table 1 below. Furthermore, as lubricants other than the monoester monocarboxylic acid amine salts represented by the general formulas (1) and (2), compounds 15 to 19 shown in the following Tables 2 and 3 were synthesized. In addition,
In Table 3 below, m, n, p, and q each represent an integer of 1 or more.

[0104]

[Table 1]

[0105]

[Table 2]

[0106]

[Table 3]

Next, a magnetic tape was manufactured as follows.

<Preparation of Sample Tape> Example 1 First, a film-shaped non-magnetic support made of polyethylene naphthalate having a thickness of 5.0 μm was coated on a nonmagnetic support by oblique vapor deposition.
o was deposited to form a metal magnetic thin film having a thickness of 80 nm as a magnetic layer.

Next, a direct current voltage of -1.2 kV was applied to the raw material of the magnetic recording medium by using a high frequency plasma of a mixed gas of ethylene and argon, with the raw material of the magnetic recording medium as a counter electrode, and a discharge was performed. About 15nm thick on top
A protective film made of carbon was formed.

Next, a back coat layer containing carbon black and a polyurethane resin having a thickness of 0.5 μm was formed on the surface of the non-magnetic support opposite to the surface on which the metal magnetic thin film was formed.
m, and then the stock was cut to a width of 6.35 mm.

Finally, a lubricant paint was prepared by dissolving Compound 1 shown in Table 1 above in toluene at a ratio of 0.2 wt% as a lubricant, and this lubricant paint was coated on a protective film by gravure roll coating. 0.5nm (30mg)
/ M ² ) to form a lubricant layer and obtain a sample tape. This is a sample tape of Example 1.

[0112] As Example 2 Lubricants were except for using Compound 2 as described in Table 1 in the same manner as in Example 1 to prepare a sample tape of Example 2.

[0113] As Example 3 lubricants and except for using Compound 3 as described in Table 1 in the same manner as in Example 1 to prepare a sample tape of Example 3.

[0114] As Example 4 lubricant and except for using Compound 4 in Table 1 above in the same manner as in Example 1 to prepare a sample tape of Example 4.

[0115] As Example 5 lubricants and except for using Compound 5 described in Table 1 in the same manner as in Example 1 to prepare a sample tape of Example 5.

[0116] As Example 6 lubricants and except for using Compound 6 as described in Table 1 in the same manner as in Example 1 to prepare a sample tape of Example 6.

[0117] As Example 7 lubricant and except for using Compound 7 as described in Table 1 in the same manner as in Example 1 to prepare a sample tape of Example 7.

[0118] As Example 8 lubricants and except for using Compound 8 described in Table 1 in the same manner as in Example 1 to prepare a sample tape of Example 8.

[0119] As Example 9 lubricant and except for using Compound 9 as described in Table 1 in the same manner as in Example 1 to prepare a sample tape of Example 9.

[0120] As Example 10 lubricant and except for using Compound 10 described in Table 1 in the same manner as in Example 1 to prepare a sample tape of Example 10.

[0121] As Example 11 lubricant and except for using Compound 11 described in Table 1 in the same manner as in Example 1 to prepare a sample tape of Example 11.

[0122] As Example 12 lubricant and except for using Compound 12 described in Table 1 in the same manner as in Example 1 to prepare a sample tape of Example 12.

[0123] As Example 13 lubricant and except for using Compound 13 described in Table 1 in the same manner as in Example 1 to prepare a sample tape of Example 13.

[0124] As Example 14 lubricant and except for using Compound 14 described in Table 1 in the same manner as in Example 1 to prepare a sample tape of Example 14.

Example 15 Compounds 1 and 2 shown in Table 1 above were used as lubricants.
Example 15 in the same manner as Example 1 except that
Was prepared.

[0126] As Comparative Example 1 lubricant, to prepare a sample tape of Example 1 Comparative Example In the same manner as 1 except for using Compound 15 described in Table 2.

[0127] As Comparative Example 2 lubricants, to prepare a sample tape of Example 1 and the same way Comparative Example 2 except for using Compound 16 described in Table 2.

[0128] As Comparative Example 3 lubricants and except for using Compound 17 described in Table 3 to prepare a sample tape of Example 1 Comparative Example In the same manner as 3.

[0129] As Comparative Example 4 lubricants, to prepare a sample tape of Example 1 compared in the same manner as in Example 4 except for using Compound 18 described in Table 3.

[0130] As Comparative Example 5 lubricant, to prepare a sample tape of Comparative Example 5 in the same manner as in Example 1 except for using Compound 19 described in Table 3.

[0131] Except for not forming the Comparative Example 6 The lubricant layer was prepared a sample tape of Comparative Example 6 in the same manner as in Example 1.

For the sample tapes of Examples 1 to 15 and Comparative Examples 1 to 6 prepared as described above, the following various measurements were made immediately after completion of each sample tape. The properties and durability were evaluated. Note that these series of measurements were performed at a temperature of 2 as an environmental condition.
The test was performed under three different conditions of 5 ° C. and 60% humidity, 40 ° C. and 30% humidity, and -5 ° C., respectively.

The running performance was evaluated by frictionally running the sample tape 100 passes on a stainless steel guide pin in a constant temperature bath controlled under the above-mentioned environmental conditions.
This was performed by measuring the coefficient of friction at the pass.

The shuttle durability was evaluated once for each sample tape using a commercially available digital video camcorder (manufactured by Sony Corporation, model name: VX-1000) in a thermostat controlled under the above-mentioned environmental conditions. 2 minutes shuttle playback is repeated, and the playback output is 3 dB from the initial output
This was done by measuring the number of shuttles before dropping.

In order to evaluate the durability, first,
A commercially available digital video camcorder (Sony, model name: VX-1)
000) was modified to enable the use of an MR head, and reproduction for 30 minutes was repeated 50 times for each sample tape. Next, MR after repeated running
The head was observed using an optical microscope, and the amount of powder falling off the MR head and the wear of the MR head were measured. In addition, the powder dust attached to the MR head was evaluated on a four-point scale. Is 50% or less of the head area and affects the output, and Δ is the level at which powder drop exceeds 50% of the head area or clogs occur during running. As the wear amount of the MR head, the difference between the height of the initial MR head and the height of the MR head after 50 times of 30 minutes of reproduction was measured as the wear amount of the MR head.

The results of the above measurement are shown in Tables 4 and 5 below.

[0137]

[Table 4]

[0138]

[Table 5]

As is apparent from Table 4 above, Examples 1 to
The sample tape of Example 15 contains at least one of the monoester monocarboxylic acid amine salts represented by the general formulas (1) and (2) as the lubricant, Under various use conditions such as high humidity, constant temperature and low humidity, or low temperature, excellent lubricity could be maintained for a long time. Further, it is possible to further suppress the occurrence of spacing loss, wear of the MR head, and powder fall, thereby making it possible to reduce output reduction and deterioration of MR head characteristics. Therefore, the magnetic recording medium according to the present invention is suitable for the MR head, and when used in a sliding state with respect to the MR head, a more remarkable improvement effect (prevention of generation of powder dropping) particularly preferable by the MR head. Etc.).

On the other hand, the sample tape of Comparative Example 1
Since the number of carbon atoms of R ¹ in the general formula (1) exceeds 30, for example, the lubricant becomes difficult to dissolve in the solvent, and as shown in Table 5, the lubricant layer can be formed. Did not. Further, in the sample tape of Comparative Example 2, the lubricant had a high coefficient of friction, as shown in Table 5 above, because the carbon number of R ¹ and R ² in the general formula (1) was less than 6, for example. As a result, the durability was inferior, and it was not possible to prevent the wear of the MR head and the occurrence of powder dropping.

The sample tapes of Comparative Examples 3 to 5 were as follows:
Since a lubricant other than the general formula (1) and the general formula (2) was used, the friction coefficient and shuttle durability were deteriorated, powder was not prevented, and the wear of the MR head was large. Was not obtained. In particular, when used in a low-temperature environment of -5 ° C, sliding members such as a drum and a fixed guide may fall off during shuttle traveling, and as a result,
A sticking phenomenon occurred, making it impossible to drive. Further, the sample tape of Comparative Example 6 was not provided with a lubricant layer, so that good results could not be obtained under various use conditions.

[0142]

According to the present invention, according to the present invention, at least one of the monoester monocarboxylic acid amine salts represented by the general formulas (1) and (2) is used as the lubricant.
The use of seeds enables excellent lubrication to be maintained over a long period of time, and prevents powder dropping, thereby reducing output and reducing head characteristics without causing spacing loss and head wear. Can be reduced.

By using the MR head (magnetoresistive read head) in a sliding state, the above-mentioned remarkable improvement effect (such as prevention of powder drop) can be obtained. This is advantageous for its specific performance (high reproduction sensitivity, etc.).

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a magnetic recording medium according to an embodiment of the present invention.

FIG. 2 is a schematic sectional view showing an example of a manufacturing apparatus that can be used to form a lubricant layer by a gravure roll method when manufacturing a magnetic recording medium according to an embodiment of the present invention.

FIG. 3 is a schematic cross-sectional view showing an example of a manufacturing apparatus that can be used to form a lubricant layer by a physical film forming method when manufacturing a magnetic recording medium according to an embodiment of the present invention.

FIG. 4 is a sectional view of a main part of a magnetoresistive read head (MR head) in which the magnetic recording medium according to the embodiment of the present invention can be suitably used.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Magnetic recording medium, 2 ... Non-magnetic support, 3 ... Magnetic layer, 4
... Protective film, 5 ... Lubricant layer, 6,6 '... Vacuum container, 7,1
3 ... guide roller, 8 ... backup roll, 9 ... media facing surface, 10 ... MR film (magnetoresistive film), 11 ...
Lubricant paint, 12: doctor blade, 19: bombard chamber, 20: heating power supply, 21: glass substrate, 22: non-magnetic layer, 23: lower core, 24: non-magnetic gap layer, 2
5A, 25B lead electrode, 26 insulating layer, 27 bias medium, 28 common core, 29 lubricant, 30 reproducing head, 31 paint tank, 33 conductance valve,
36 gravure roll, 37 dry pump, 40 recording head, 44 conductor coil, 45A, 45B flattening film (interlayer insulating film), 46 upper core, 49 gap material, 50 MR head

Claims (5)

[Claims] In a magnetic recording medium used in a sliding state with respect to a magnetoresistive read head, a monoester monocarboxylic acid represented by the following general formulas (1) and (2) is formed on a magnetic layer. A magnetic recording medium provided with a lubricant layer containing at least one of acid amine salts. Embedded image [However, in the general formula (1) and the general formula (2), R ¹ , R ³ , R ⁴ , R ⁵ and R ⁶ are each independently:
A C 6-30 aliphatic alkyl group, a C 6-30 aliphatic alkenyl group or a hydrogen atom, and R ² is a C 6-30 fluoroalkyl group or a C 6-30 fluoroalkenyl group. is there. ] 2. The magnetic recording medium according to claim 1, wherein the amine has an alkyl group having 6 or more carbon atoms. 3. A ferromagnetic metal thin film as a magnetic layer, a protective film, and the lubricant layer are formed on a non-magnetic support for use in a helical scan magnetic recording system using the magnetoresistive read head. 2. The magnetic recording medium according to claim 1, wherein the lubricant layer is formed by a coating method or a physical film forming method. 4. The magnetic recording medium according to claim 2, wherein the physical film forming method is a vacuum evaporation method, a sputtering method, or a pulse laser deposition method. 5. The magnetic recording medium according to claim 1, wherein the amount of the lubricant constituting the lubricant layer is 0.1 to 100 mg / m ² .