JPH09104881A - Magnetic medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a magnetic medium having a low friction coefficient and a low fluctuation of output (voltage) and excellent in durability in still picture playing and long time recording and playing by forming at least a magnetic layer on a non-magnetic base and allowing the magnetic layer to contain a specific lubricating agent. SOLUTION: This magnetic medium has at least a magnetic layer on a non- magnetic base and a lubricating agent which is a compound of formula I [R1 and R2 are each a 1-30C (branched) alkyl; Rf1 is a 1-30C (branched) fluoroalkyl; X is H or F] or a compound of formula II (R3 and R4 are each R1 ; Rf2 is Rf1 ) in an amount of 0.05-100mg/m<2> applied directly on the magnetic layer or via a protective layer coated on the magnetic layer, on the surface of the magnetic medium.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording medium, and more particularly to a magnetic recording medium having a low friction coefficient value and improved durability.

[0002]

2. Description of the Related Art Increasing the recording density of a magnetic recording medium is achieved by improving the magnetic characteristics, thinning the magnetic layer, or enhancing the smoothness of the magnetic layer surface. To be done. However, thinning the magnetic layer or improving the smoothness of the surface causes problems such as wear of the magnetic layer due to contact with the head during sliding, and an increase in friction coefficient during running. Specifically, the following two points are highlighted as major problems.

(1) The wear of the magnetic layer when the VTR is operated in the pause state is prevented, and the deterioration of the output is suppressed. (Still durability) (2) It suppresses an increase in the coefficient of friction when the recording / reproducing reciprocating motion is repeated.

Therefore, in order to solve these problems, the use of various lubricants such as higher fatty acids and their esters has been proposed. In this case, the coating amount of the lubricant is limited to almost a monomolecular level, and in particular, since the metal thin film magnetic recording medium cannot be supplemented with the lubricant,
The lubricant is required to be thermally and chemically stable on the magnetic layer. However, commercially available lubricants cannot fully satisfy their lubricating properties, and it is pointed out that the development of new lubricants or lubricant compositions is important.

As such a novel lubricant, a fluorine-based lubricant has been actively used in recent years. For example, as commercially available fluorine-based lubricants, Demnum SA manufactured by Daikin Industries or Fomblin Z manufactured by Aojimont Co., which has the following chemical structure, is used.
DOL and the like are known.

[0006]

Embedded image

Although these fluorine-based lubricants have good durability, they cannot suppress the increase in the friction coefficient when the recording / reproducing reciprocating motion is repeated.
Therefore, JP-A-4-178357 and JP-A-4-178357
In Japanese Patent No. 271013, it is proposed to improve the slipperiness and durability of a magnetic recording medium by using a fluorine-containing compound having both an alkyl group and a fluoroalkyl group. However, with the increasing recording density of magnetic recording media, it is the current situation that satisfactory lubricity and durability have never been obtained even with such lubricants.

Therefore, an object of the present invention is to provide a magnetic recording medium which has a low friction coefficient value and whose output does not fluctuate even after recording and reproducing for a long time.

[0009]

In order to achieve the above object,
The inventors of the present invention have diligently studied, and by using a specific fluorine-containing carboxylic acid ester lubricant or fluorine-containing carboxylic acid amide lubricant, the friction coefficient value is reduced,
It was found that a magnetic recording medium without output fluctuation can be obtained.

The present invention has been made on the basis of the above findings, and has at least a magnetic layer on a non-magnetic support and contains a fluorine-containing carboxylic acid ester represented by the following formula (1). The above object is achieved by providing a magnetic recording medium characterized by the above.

[0011]

Embedded image (In the formula, R ₁ and R ₂ represent a linear or branched alkyl group having 1 to 30 carbon atoms, and R _f1 represents a linear or branched fluoroalkyl group having 1 to 30 carbon atoms, X represents H or F.)

Further, according to the present invention, there is provided a magnetic recording medium having at least a magnetic layer on a non-magnetic support and containing a fluorine-containing carboxylic acid amide represented by the following formula (2). The above object is achieved by providing the following.

[0013]

Embedded image (In the formula, R ₃ and R ₄ represent a linear or branched alkyl group having 1 to 30 carbon atoms, and R _f2 represents a linear or branched fluoroalkyl group having 1 to 30 carbon atoms, X represents H or F.)

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The magnetic recording medium of the present invention will be described below in detail. First, the fluorinated carboxylic acid ester represented by the above formula (1) used in the magnetic recording medium of the present invention will be described. The fluorinated carboxylic acid ester is used as a lubricant in the magnetic recording medium. . In the above formula (1), R ₁ and R ₂ are alkyl groups having 1 to 30 carbon atoms. In this case, R ₁ and R
The alkyl groups in ₂ may be the same or different. Further, the alkyl group may be linear or branched. Further, the number of carbon atoms in the alkyl group is preferably 1
-25, more preferably 1-20, still more preferably 1-15. Particularly preferred examples of the alkyl group include CH ₃ , C ₂ H ₅ , C ₆ H ₁₃ , C ₈ H ₁₇ ,
C ₁₁ H _23, C ₁₅ H _{31 and the} like can be mentioned.

In the above formula (1), R _f1 has 1 carbon atom.
To 30 fluoroalkyl groups. The fluoroalkyl group may be linear or branched. The number of carbon atoms in the fluoroalkyl group is preferably 2-20, more preferably 5-20. Particularly preferred examples of the fluoroalkyl group include C ₂ F ₅ , C ₅ F ₁₁ ,
_{C 6 F 13, C 7 F} 15, C 8 F 17, (CF 3) 2 CF (CF
₂ ) ₆ and C ₁₅ F ₃₁ .

In the above formula (1), X is H or F. The X may be H or F depending on the types of the substituents R ₁ , R ₂ and R _f1 .

Particularly preferred specific examples of the fluorine-containing carboxylic acid ester represented by the above formula (1) include ethyl 3-heptadecafluorooctylbutanoate, ethyl 3-nonadecafluoroisononylbutanoate and 3-heneico. Ethyl safluorodecyl butanoate, 3-heptadecafluorooctyl octyl butanoate, ethyl 3-heneicosafluorodecyl pentanoate, ethyl 3-heptadecafluorooctyl-3-fluorobutanoate, 3-heptadecafluorooctyl-3 -Ethyl fluoropentanoate, pentadecyl 3-nonadecafluoroundecaate and the like can be mentioned.

Next, the fluorinated carboxylic acid amide represented by the above formula (2) will be described. The fluorinated carboxylic acid amide is used as a lubricant in a magnetic recording medium. In the above formula (2), R ₃ and R ₄ are
It is an alkyl group having 1 to 30 carbon atoms. In this case, the alkyl groups in R ₃ and R ₄ may be the same or different. Further, the alkyl group may be linear or branched. Further, the number of carbon atoms in the alkyl group is preferably 1 to 25, more preferably 1 to 20. Particularly preferred examples of the alkyl group include CH ₃ , C ₂ H
_5, C ₈ H ₁₇ and C ₁₅ H ₃₁ and the like.

In the above formula (2), R_f2Has 1 carbon
To 30 fluoroalkyl groups. The fluoroalkyl
The radical may be straight or branched. In addition,
The number of carbon atoms in the fluoroalkyl group is preferably 2-20.
And more preferably 5 to 20. The fluoroalkyl
As a particularly preferred example of the group_FiveF₁₁, C₆F₁₃,
C₈F₁₇, (CF_Three)_TwoCF (CF_Two)₆, C_FifteenF₃₁as well as
(CF_Three)_TwoCF (CF_Two) ₁₇Etc. can be mentioned.

In the above formula (2), X is H or F. The X may be H or F depending on the types of the substituents R ₃ , R ₄ and R _f2 .

Particularly preferred specific examples of the fluorine-containing carboxylic acid amide represented by the above formula (2) include 3-heptadecafluorooctylbutanoic acid stearylamide, 3-nonadecafluoroisononylbutanoic acid stearylamide,
3-heneicosafluorodecylbutanoic acid stearylamide, 3-heneicosafluorodecylbutanoic acid stearylamide, 3-heptadecafluorooctyl-3-fluorobutanoic acid palmitylamide, and 3-heptadecafluorooctyl-3- Fluoropentanoic acid palmitylamide and the like can be mentioned.

The molecular weight of the fluorine-containing carboxylic acid ester represented by the above formula (1) and the fluorine-containing carboxylic acid amide represented by the above formula (2) is not particularly limited, but the molecular weight in a general range is It is preferably about 500 to 5000. When the molecular weight is less than 500, sufficient lubricity cannot be obtained, and when it exceeds 5,000, the effect of the terminal group may not be sufficiently exerted, so the above range is preferable.

The fluorine-containing carboxylic acid ester represented by the above formula (1) and the fluorine-containing carboxylic acid amide represented by the above formula (2) have an alkyl group (in the above-mentioned fluorine-containing carboxylic acid ester) in the molecule. , R ₁ and R ₂ , and in the above fluorine-containing carboxylic acid amide, R ₃ and R ₄ )
And (In the above fluorine-containing carboxylic acid ester, R _f1, in the fluorine-containing carboxylic acid amide, R _f2) fluoroalkyl group contains a. In this case, the alkyl group contributes to the slip property (friction coefficient value of the magnetic recording medium) of the properties of the lubricant, while the fluoroalkyl group contributes to the durability (of the magnetic recording medium) of the properties of the lubricant. Output fluctuation). And in the present invention,
By using a specific alkyl group and fluoroalkyl group together with a carboxylic acid ester or a carboxylic acid amide as a main skeleton of the lubricant, the lubricity and durability of the lubricant are improved.

Next, the method for synthesizing the fluorine-containing carboxylic acid ester represented by the above formula (1) and the fluorine-containing carboxylic acid amide represented by the above formula (2) will be described. The fluorine-containing carboxylic acid ester can be easily synthesized, for example, according to the reaction formula [I] shown below.

[0025]

Embedded image

That is, in the fluorine-containing carboxylic acid ester represented by the above formula (1), fluoroiodide (a) and alkylenecarboxylic acid ester (b) are combined with azobisisobutyronitrile (AIBN) or peroxide. Benzoyl (Bz
OOBz) in the presence of the resulting fluoroalkyl-iodo-alkylcarboxylic acid ester (c),
Obtained by bubbling hydrogen chloride gas in the presence of zinc powder. The carboxylic acid as a raw material of the alkylene carboxylic acid ester (b) is N. O. Brace
Et al. [J. Org. Chem. Vol. 27, P4
491 (1962)].

The fluorine-containing carboxylic acid amide represented by the above formula (2) is an ester-amide exchange method according to the following reaction formula [II] using the fluorine-containing carboxylic acid ester represented by the above formula (1) as a raw material. Alternatively, it can be synthesized by the reaction of a carboxylic acid and an amine using a condensing agent such as DCC (dicyclohexylcarbodiimide) according to the reaction formula [III].

[0028]

Embedded image

The fluorine-containing carboxylic acid ester represented by the above formula (1) and the fluorine-containing carboxylic acid amide represented by the above formula (2) are preferably a thin film directly on the magnetic layer in the magnetic recording medium of the present invention. Or a thin film via a protective layer provided on the magnetic layer to act as a lubricant layer. That is, the fluorinated carboxylic acid ester represented by the above formula (1) and the fluorinated carboxylic acid amide represented by the above formula (2) exist as a lubricant layer provided on the above magnetic layer (the above magnetic property). When a protective layer is provided on the layer, it is present as a lubricant layer provided on the protective layer). There is no particular limitation on the method of applying the above-mentioned fluorine-containing carboxylic acid ester and the above-mentioned fluorine-containing carboxylic acid amide, and for example, a wet coating method using a sprayer equipped with an ultrasonic oscillator or a dry coating method such as vacuum deposition can be used. .

The content (adhesion amount) of the above-mentioned fluorine-containing carboxylic acid ester and the above-mentioned fluorine-containing carboxylic acid amide in the magnetic recording medium of the present invention should be appropriately adjusted according to the form (tape, disk) of the magnetic recording medium. However, the content (adhesion amount) as a general range is preferably 0.05 to 100 mg, and more preferably 1 to 50 mg per 1 m ² of the surface of the magnetic recording medium. If the content (adhesion amount) is less than 0.05 mg / m ² , sufficient lubricity and durability may not be obtained and the head or tape may be damaged. If it exceeds 100 mg / m ² , the tape Since sticking or clogging of the head may occur, it is preferably within the above range.

In the present invention, the above-mentioned fluorine-containing carboxylic acid ester or the above-mentioned fluorine-containing carboxylic acid amide may be used alone, or may be used in combination with a lubricant usually used in magnetic recording media. Further, if necessary, other additives such as phenols, quinones and naphthols, and heterocyclic compounds containing nitrogen atom, oxygen atom or sulfur atom may be used in combination. In these cases, the lubricant and the additive are 100 parts by weight of the fluorine-containing carboxylic acid ester or the fluorine-containing carboxylic acid amide,
It is preferable to add 1 to 30 parts by weight.

As described above, the magnetic recording medium of the present invention comprises at least a magnetic layer on a non-magnetic support. Examples of the magnetic layer include a coating type magnetic layer formed by coating a magnetic coating material containing magnetic powder and a binder on the non-magnetic support, and a physical vapor layer such as sputtering, vacuum deposition or ion plating. Phase growth method (PVD
Method) can be used. Of these magnetic layers, it is particularly preferable to use a metal thin film type magnetic layer.

The metal thin film type magnetic layer will be described. Examples of the metal forming the magnetic layer include Fe and C.
In addition to metals such as o and Ni, Co-Ni alloys, Co-Pt
Alloy, Co-Ni-Pt alloy, Fe-Co alloy, Fe-
A Ni alloy, an Fe-Co-Ni alloy, an Fe-Co-B alloy, a Co-Ni-Fe-B alloy, a Co-Cr alloy, or those containing a metal such as Al is used. In addition, Fe-N, Fe-N-O, Fe-C, Fe
-CO is also used. It is preferable that an oxidizing gas be supplied at the time of forming the metal thin film to form a protective layer made of an oxide film on the surface of the metal thin film.

The magnetic layer may be composed of one metal thin film, or may be composed of two or more metal thin films. When the magnetic layer is composed of two or more metal thin films, the material of each metal thin film may be the same or different. The magnetic layer preferably has a total thickness of generally 500 to 5,000 liters.

As the support on which the magnetic layer is provided, a known non-magnetic support can be used without particular limitation. Specifically, known resins such as polyethylene terephthalate, polyethylene naphthalate, polyphenylene sulfide, polycarbonate, polyamide, polyimide, polyamide imide, polysulfone, aramid, and aromatic polyamide; metals such as aluminum and copper; paper and the like are used. be able to. The form may be any of a film, tape, sheet, disk, drum and the like. Before providing the magnetic layer on the support, the surface of the support is previously subjected to corona discharge treatment in air and / or in vacuum,
Plasma treatment, easy adhesion treatment, heat treatment, dust removal treatment, bombardment treatment, and the like can also be performed. The preferred thickness of the support is 1 to 300 μm.

When a protective layer is provided on the magnetic layer, the protective layer generally contains carbon or a carbide, a nitride or an oxide in a vacuum, particularly diamond-like carbon, diamond, boron carbide or silicon carbide. It is formed by forming a film of boron nitride, silicon nitride, silicon oxide, chromium oxide, aluminum oxide, or the like. As the protective layer, it is particularly preferable to use a carbon thin film layer in an amorphous state, a graphite state, a diamond state, or a mixed state or a laminated state thereof. The thickness of the protective layer is not particularly limited, but is generally 3
It is preferably 0 to 300Å. As the method of forming the protective layer, there are chemical vapor deposition (CVD method) and PVD.
Either method may be used. In the CVD method, an ECR (Electron Cyclotron Resonance) method using a microwave and a method using a high frequency (RF) are particularly effective. When the protective layer is formed by the CVD method, the raw material may be any of gas, liquid and solid.

In the magnetic recording medium of the present invention, other layers can be provided, if necessary, in addition to the above protective layer. For example, an undercoat layer may be provided between the support and the magnetic layer to improve the adhesion between the two, or a surface of the support opposite to the surface on which the magnetic layer is formed. In addition, a back coat layer for improving running properties and durability of the magnetic recording medium can be provided.

Further, the above-mentioned fluorine-containing carboxylic acid ester or the above-mentioned fluorine-containing carboxylic acid amide can be applied on the above-mentioned back coat layer, if necessary. In this case, the back coat layer may be any of a coating type and a metal thin film type, but is preferably a metal thin film type back coat layer. The metal thin film type back coat layer generally comprises
It is formed by forming a film of Al, Cu, Si, Fe, Mo, Mn, Zn or the like, or an alloy or oxide thereof. The thickness of the back coat layer is generally 500.
It is preferably from 10000 to 10000 °. Further, regarding the adhesion amount of the above-mentioned fluorine-containing carboxylic acid ester or the above-mentioned fluorine-containing carboxylic acid amide in the above-mentioned back coat layer, the forming method, the additive, etc., the detailed description on the above-mentioned magnetic layer side is similarly applied.

The magnetic recording medium of the present invention is used in the form of tape, disc, drum, sheet and other forms,
It is particularly preferably used in the form of a magnetic tape.

In addition to the above description, the description about the conventional magnetic recording medium applies to the points not particularly described in detail. Further, in the fluorine-containing carboxylic acid ester represented by the above formula (1) and the fluorine-containing carboxylic acid amide represented by the above formula (2), X is, in addition to H or F, an alkyl group, an alkyloxy group, A perfluoroalkyl group or a perfluoroalkyloxy group may be used. Further, instead of the alkyl group of R ₁ and R ₃ , R ₁ O
- and may be used alkyl group represented by R ₃ O-, likewise, fluoroalkyloxy represented by O-R _f1 O-and R _f2 instead fluoroalkyl group R _f1 and R _f2 A group may be used. Furthermore, in the above formulas (1) and (2), instead of the —CH ₂ —COO— skeleton,
It may be used -CH ₂ -O-COO- backbone.

[0041]

EXAMPLES The magnetic recording medium of the present invention will be described in more detail below with reference to examples. However, the present invention is not limited to such an embodiment.

Example 1 Synthesis of Ethyl 3-Heptadecafluorooctyl Butanoate 55 g of heptadecafluorooctyl iodide and 2-
A small amount of iodine was added to a mixture of 11 g of ethyl butyrate and reacted at 145 ° C. for 8 hours. After completion of the reaction, distillation / purification was performed under reduced pressure to obtain ethyl 3-heptadecafluorooctyl-2-iodo-butanoate (yield 80
%). Obtained 3-heptadecafluorooctyl-2-
Ethyl iodo-butanoate was dissolved in absolute ethanol. Dry hydrogen chloride gas was bubbled into this solution, zinc powder was added, and the mixture was stirred at 70 ° C. After completion of the reaction, zinc powder was filtered off and the filtrate was extracted with ether. Further, distillation and purification were performed under reduced pressure to obtain the title target compound.

[Examples 2 to 8] The fluorine-containing carboxylic acid ester shown in Table 1 was synthesized in the same manner as in Example 1.

[0044]

[Table 1]

Example 9 Synthesis of 3-heptadecafluorooctylbutanoic acid stearylamide [0045] 50 g of ethyl 3-heptadecafluorooctylbutanoate synthesized in Example 1 and 12 g of stearylamine were added,
The reaction was carried out at 150 ° C for 6 hours. After cooling, the reaction crude product was purified by silica gel column chromatography to obtain the title object compound (yield 54%).

[Examples 10 to 15] In the same manner as in Example 9, the fluorine-containing carboxylic acid amides shown in Table 2 were synthesized from the corresponding fluorine-containing carboxylic acid ester.

[0047]

[Table 2]

[Examples 16 to 30] Co was deposited on a PET film having a thickness of 6 μm by oblique vapor deposition while introducing oxygen.
To form a ferromagnetic metal thin film magnetic layer having a film thickness of 1800 Å. Next, 60 L of DLC was formed on the surface of the magnetic layer by the plasma CVD method. Next, each of the lubricants obtained in Examples 1 to 15 was dissolved in Fluorinert FC-77 (fluorine-based solvent, manufactured by 3M Co., Ltd.) so that the solution had a dry coating amount of 8 mg / m ^2. Each was applied to form a lubricant layer coating film. After the coating film was dried, the film was slit into a width of 1/4 inch to prepare a metal thin film type magnetic tape.

With respect to each magnetic tape, the friction coefficient value under the environment of temperature 23 ° C. and humidity 50% RH (measurement conditions are shown below) was measured, and the relative speed was 10 using the drum tester shown in FIG. The output fluctuation (ΔOutput) after running for 60 minutes at 0.2 m / s was measured (measurement conditions are shown below). Table 3 shows the results.

<Conditions for Measuring Friction Coefficient Value> As shown in FIG. 2, a sample magnetic tape 1 was hung on a φ5 mm SUS guide pin 2 so as to be in contact with the outer periphery of an angle of 115 ° (2 rad), and a load was applied to one end of the magnetic tape. (T ₂ ) 20 g is applied, and the tension T ₁ applied to the other end of the tape when running at a tape speed of 14.3 mm / s is measured. From the above results, the friction coefficient value μ was calculated from the following formula. μ = (1 / θ) ln (T ₁ / T ₂ )

<Specifications of Head Used in Drum Tester> Head used 8 mm VCR / EP head Track width: 15 μm Effective gap length: 0.23 μm

[Comparative Examples 1 to 5] Magnetic tapes were obtained in the same manner as in Example 16 except that no lubricant was used (Comparative Example 1). Also, as a lubricant, Daikin Industries Demnum S
Magnetic tapes were obtained in the same manner as in Example 16 except that A and Fomblin Z DOL manufactured by Aojimont were used (Comparative Examples 2 and 3). Furthermore, as a lubricant, RC
OO-R _f (wherein, R represents an alkyl group, R _f represents a fluoroalkyl group. The average molecular weight is 2500.) And the compound represented by R _f '-R'-COOH
(In the formula, R _f 'is a perfluoroalkyl group, and R'
Is an alkylene group. The average molecular weight is 2200. Magnetic tapes were obtained in the same manner as in Example 16 except that each of the compounds represented by () was used (Comparative Examples 4 and 5). The same measurement as in Example 16 was performed on each magnetic tape. Table 3 shows the results.

[0053]

[Table 3]

As is clear from the results shown in Table 3, the magnetic material of the present invention containing the fluorine-containing carboxylic acid ester represented by the above formula (1) or the fluorine-containing carboxylic acid amide represented by the above formula (2). The recording media (Examples 16 to 30) have low friction coefficient values and no output fluctuation is observed. On the other hand, in the magnetic tape not using the lubricant (Comparative Example 1) and the magnetic tape using the conventional lubricant (Comparative Examples 2 to 5), the friction coefficient value was high and the decrease in the output was observed. It was

[0055]

As described above, according to the present invention,
Since a specific fluorine-containing carboxylic acid ester or fluorine-containing carboxylic acid amide is used as the lubricant, a magnetic recording medium having a low friction coefficient value and little output fluctuation can be obtained. Therefore, the magnetic recording medium of the present invention is excellent in still durability and durability when recording / reproducing for a long time.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a method of measuring an output fluctuation of a magnetic recording medium using a drum tester.

FIG. 2 is a schematic view showing an apparatus for measuring a friction coefficient of a magnetic tape.

[Explanation of symbols]

 1 magnetic tape 2 guide pin

Claims (6)

[Claims] 1. A magnetic recording medium comprising at least a magnetic layer on a non-magnetic support and containing a fluorinated carboxylic acid ester represented by the following formula (1). Embedded image (In the formula, R ₁ and R ₂ represent a linear or branched alkyl group having 1 to 30 carbon atoms, and R _f1 represents a linear or branched fluoroalkyl group having 1 to 30 carbon atoms, X represents H or F.) 2. The magnetic recording medium according to claim 1, wherein the fluorine-containing carboxylic acid ester is applied directly on the magnetic layer or via a protective layer provided on the magnetic layer. . 3. A magnetic recording medium comprising at least a magnetic layer on a non-magnetic support and containing a fluorine-containing carboxylic acid amide represented by the following formula (2). Embedded image (In the formula, R ₃ and R ₄ represent a linear or branched alkyl group having 1 to 30 carbon atoms, and R _f2 represents a linear or branched fluoroalkyl group having 1 to 30 carbon atoms, X represents H or F.) 4. The magnetic recording medium according to claim 3, wherein the fluorine-containing carboxylic acid ester is applied directly on the magnetic layer or via a protective layer provided on the magnetic layer. . 5. A fluorine-containing carboxylic acid ester lubricant for a magnetic recording medium represented by the following formula (1). Embedded image (In the formula, R ₁ and R ₂ represent a linear or branched alkyl group having 1 to 30 carbon atoms, and R _f1 represents a linear or branched fluoroalkyl group having 1 to 30 carbon atoms, X represents H or F.) 6. A fluorine-containing carboxylic acid amide lubricant for a magnetic recording medium represented by the following formula (2). Embedded image (In the formula, R ₃ and R ₄ represent a linear or branched alkyl group having 1 to 30 carbon atoms, and R _f2 represents a linear or branched fluoroalkyl group having 1 to 30 carbon atoms, X represents H or F.)