JP2002332261A - Perfluoropolyalkyl ether compound, lubricant comprising the compound, and recording medium using the lubricant - Google Patents

Abstract

(57) [Summary] [PROBLEMS] While maintaining excellent lubricity under various use conditions, the lubricating effect is maintained for a long time,
A lubricant for a recording medium capable of producing a recording medium having excellent running properties, wear resistance, durability, and the like. SOLUTION: For example, C ₁₈ H ₃₇ -CH (COOC
_{18 H 37) CH 2 COO-} Rf-OCOCH 2 CH (COO
_{C 18 H 37) -C 18 H} 37 (Rf uses fluoropolyether group) with an average molecular weight of 2,000 as a lubricant for magnetic recording media.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a perfluoropolyalkyl ether compound, a lubricant for a recording medium comprising the compound, and a recording medium having a lubricant layer containing the lubricant.

[0002]

2. Description of the Related Art As a conventional recording medium, for example, a magnetic recording medium, a so-called metal thin film type magnetic recording in which a ferromagnetic metal material is deposited on a non-magnetic support by a method such as evaporation and the like is used as a magnetic layer. There is known a medium or a so-called coating type magnetic recording medium in which a magnetic paint containing very fine magnetic particles and a resin binder is applied on a non-magnetic support, and this is used as a magnetic layer. Since these conventional magnetic recording media have extremely good smoothness on the surface of the magnetic layer, a substantial contact area with a sliding member such as a magnetic head or a guide roller is large,
Therefore, there are many problems such as a large friction coefficient, an adhesion phenomenon (so-called sticking) easily occurring, and a lack of running performance and durability. Therefore, the use of various lubricants to improve these problems has been studied. Conventionally, higher fatty acids or esters thereof have been internally added to the magnetic layer of the magnetic recording medium, or a top coat has been used. Attempts have been made to reduce the coefficient of friction by doing so.

[0003] However, lubricants used for magnetic recording media are required to have extremely severe properties due to their properties.
At present, it is difficult to satisfy the demand with a conventionally used lubricant.

[0004] Lubricants used in magnetic recording media include (1) excellent low-temperature characteristics so as to ensure a predetermined lubricating effect when used in cold regions, and (2) lubricants for magnetic heads. Since pacing poses a problem, it is required that it can be applied extremely thinly and that sufficient lubricating properties be exhibited even in such a case, and (3) that it can withstand long-term use or long-term use and that the lubricating effect be maintained. Is done.

Japanese Patent Application Laid-Open No. 6-41561 discloses that
As a lubricant for a metal thin film type magnetic recording medium, a fluorine-containing alkyl succinic diester represented by the following general formula (i) has been proposed.

[0006]

Embedded image R ¹ —CH (COOR ² ) CH ₂ COOR ³ (i)

In the formula, R ¹ is an aliphatic alkyl group or an aliphatic alkenyl group, one of R ² and R ³ is a fluoroalkyl ether group, and the other is a fluoroalkyl group, a fluoroalkenyl group, a fluorophenyl group, Aliphatic alkyl group,
Any of aliphatic alkenyl groups. However, the above-mentioned fluorine-containing alkyl succinic diester has a problem that the coefficient of friction is large.

[0008]

As described above, in the field of recording media, due to insufficient capacity of the lubricant used, for example, the reproduction output is reduced in a shuttle running test, and the practical characteristics are reduced. I am dissatisfied. Therefore, the present invention, while maintaining excellent lubricity under various use conditions, the lubrication effect is maintained for a long time,
It is an object of the present invention to provide a compound capable of providing excellent running properties, abrasion resistance, durability and the like, a lubricant comprising the compound, and a recording medium.

[0009]

That is, the present invention provides the following general formula (1):

[0010]

Embedded image R ¹ —CH (COOR ² ) CH ₂ COO—Rf—OCOCH ₂ CH (COOR ² ) —R ¹ (1)

Wherein R ¹ represents a saturated or unsaturated aliphatic hydrocarbon group having 6 to 30 carbon atoms, Rf represents a fluoropolyether group having an average molecular weight of 500 to 6000, and R ² represents A saturated or unsaturated aliphatic hydrocarbon group having 1 to 30 carbon atoms (but may have a ketone group in part), or a fluoroalkyl group or fluoroalkenyl having 1 to 30 carbon atoms A perfluoropolyalkyl ether compound represented by the formula: Further, the present invention provides the following general formula (1):

[0012]

Embedded image R ¹ —CH (COOR ² ) CH ₂ COO—Rf—OCOCH ₂ CH (COOR ² ) —R ¹ (1)

(Wherein, R ¹ represents a saturated or unsaturated aliphatic hydrocarbon group having 6 to 30 carbon atoms, Rf represents a fluoropolyether group having an average molecular weight of 500 to 6000, and R ² represents A saturated or unsaturated aliphatic hydrocarbon group having 1 to 30 carbon atoms (but may have a ketone group in part), or a fluoroalkyl group or fluoroalkenyl having 1 to 30 carbon atoms Or a fluoroether group.) The present invention also provides a lubricant for a recording medium comprising a perfluoropolyalkyl ether compound represented by the formula: Furthermore, the present invention
A recording medium in which a recording layer and a lubricant layer composed of a lubricant are formed at least sequentially on a support, wherein the lubricant has the following general formula (1):

[0014]

Embedded image R ¹ —CH (COOR ² ) CH ₂ COO—Rf—OCOCH ₂ CH (COOR ² ) —R ¹ (1)

(Wherein, R ¹ represents a saturated or unsaturated aliphatic hydrocarbon group having 6 to 30 carbon atoms, Rf represents a fluoropolyether group having an average molecular weight of 500 to 6000, and R ² represents A saturated or unsaturated aliphatic hydrocarbon group having 1 to 30 carbon atoms (but may have a ketone group in part), or a fluoroalkyl group or fluoroalkenyl having 1 to 30 carbon atoms A perfluoropolyalkyl ether compound represented by the following formula:

The perfluoropolyalkyl ether compound of the present invention is a novel substance, and by using it as a lubricant for a recording medium, especially for a magnetic recording medium, excellent lubricity can be maintained under various use conditions. With
It is possible to provide a recording medium in which the lubricating effect is maintained for a long time and has excellent running properties, wear resistance, durability and the like.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the case where the compound of the present invention is used as a lubricant for a magnetic recording medium will be described as an example.

In the perfluoropolyalkyl ether compound of the present invention, R ¹ is a saturated or unsaturated aliphatic hydrocarbon group having 6 to 30, preferably 8 to 20 carbon atoms. This aliphatic hydrocarbon group may be straight-chain or branched. If the number of carbon atoms in R ¹ is less than 6 or more than 30, the solubility in an organic solvent decreases, and it becomes impossible to form a lubricant layer film on the carbon film layer using the organic solvent.

Rf has an average molecular weight of 500 to 600.
0, preferably 1000 to 4000 fluoropolyether groups. When the average molecular weight of Rf is less than 500, the fluoropolyether group is too short and the friction coefficient increases. Conversely, if the average molecular weight of Rf exceeds 6000, the solubility in an organic solvent decreases, and it becomes impossible to form a lubricant layer film on, for example, a carbon film layer using an organic solvent.

Further, R ² is a saturated or unsaturated aliphatic hydrocarbon group having 1 to 30, preferably 1 to 20 carbon atoms, or a fluoroalkyl group, a fluoroalkenyl group or a fluoroalkyl group having 1 to 30 carbon atoms. It is a fluoroether group. Here, the aliphatic hydrocarbon group may be linear or branched. Further, the aliphatic hydrocarbon group may have a ketone group in a part thereof. When the number of carbon atoms of R ² exceeds 30, the solubility in an organic solvent decreases, and it becomes impossible to form a lubricant layer film on the carbon film layer using the organic solvent.

The perfluoropolyalkyl ether compound of the present invention comprises, for example, a succinic acid derivative containing an R ¹ group in the general formula (1) and a compound containing a fluoropolyether group (Rf) in the general formula (1). Mixing, heating and reacting, washing with an organic or inorganic solvent,
The compound can be synthesized by reacting a product containing an R ² group with a product from which impurities and unnecessary substances have been removed by separation washing using a separation funnel, purification using column chromatography, and the like.

As the compound containing a fluoropolyether group (Rf) in the general formula (1), commercially available compounds can be used.
Made, trade name Z-dol 1000, Z-dol 200
0, Z-dol 4000 and the like. The Zd
ol 1000 has a structural formula of HOCH ₂ (CF ₂ CF ₂
O) Average molecular weight with m (CF ₂ O) n CH ₂ OH 100
0 (Z-dol 2000 and Zd
ol 4000 is a compound having the same structural formula as Z-dol 1000, but having an average molecular weight of 2000
And 4000).

Further, as described above, the perfluoropolyalkyl ether compound of the present invention can be suitably used as a lubricant for a recording medium, especially a magnetic recording medium. In addition, various additives, for example, a rust preventive may be added to the lubricant as needed. As the rust inhibitor, those used in conventional magnetic recording media can be used, for example, phenols, naphthols, quinones, heterocyclic compounds containing a nitrogen atom, heterocyclic compounds containing an oxygen atom, sulfur Heterocyclic compounds containing atoms and the like can be mentioned.

The recording medium of the present invention is provided with a lubricant layer containing the above-mentioned lubricant. For example, in the case of a magnetic recording medium, specifically, it is formed on a non-magnetic support by a method such as vapor deposition. It is a so-called metal thin film type magnetic recording medium in which a magnetic layer composed of a formed metal magnetic thin film, a carbon film layer and a lubricant layer containing the perfluoropolyalkyl ether compound of the present invention are formed at least sequentially. it can. Further, an underlayer may be formed between the nonmagnetic support and the magnetic layer, if necessary.

The nonmagnetic support is not particularly limited, and a known one can be used. For example,
When a rigid substrate such as an Al alloy plate or a glass plate is used as the non-magnetic support, an oxide film such as alumite treatment or a Ni-P film is formed on the substrate surface so that the surface is hardened. You may.

The metal magnetic thin film constituting the magnetic layer is not particularly limited, and a known magnetic thin film can be employed. For example, it is formed as a continuous film by a technique such as plating, sputtering, or vacuum deposition.
e, metal such as Co, Ni, Co-Ni alloy, Co-P
t-based alloy, Co-Pt-Ni-based alloy, Fe-Co-based alloy, Fe-Ni-based alloy, Fe-Co-Ni-based alloy, Fe
-Ni-B alloy, Fe-Co-B alloy, Fe-Co
An in-plane magnetization recording metal magnetic thin film made of a -Ni-B alloy or the like; a Co-Cr alloy magnetic thin film; In particular, when an in-plane magnetization recording metal magnetic thin film is adopted, Bi, Sb, Pb, Sn, Ga, In,
A base layer of a low-melting non-magnetic material such as Ge, Si, or Tl is formed, and the above metals are deposited or sputtered on the base layer in a direction perpendicular to the base layer, and these low-melting non-magnetic materials are formed in a metal magnetic thin film. The material may be diffused to eliminate orientation and secure in-plane isotropy and improve coercivity.

As a method of forming the carbon film layer, sputtering is generally used, but is not particularly limited, and any known method can be adopted. The thickness of the carbon film is preferably from 2 to 100 nm, more preferably from 5 to 30 nm.

The lubricant layer can be formed by top-coating a lubricant containing the perfluoropolyalkyl ether compound of the present invention on the carbon film layer by a conventional method. The amount of the lubricant to be applied is, for example, 0.5 to 100 mg.
/ M ² by weight, more preferably 1 to 20 mg / m ^2. For coating, a solution obtained by dissolving a lubricant in an organic solvent such as hexane can be used. When a rust preventive is used, it may be used in combination with a lubricant. However, if the rust preventive is applied on the carbon film layer and then the lubricant is applied and two or more layers are provided, the rust preventive may be used. The rust effect is enhanced, which is preferable.

As described above, the fluoropolyalkyl ether compound of the present invention is preferably used as a lubricant for a recording medium, especially a magnetic recording medium. However, the lubricant of the present invention can be applied not only to a magnetic recording medium (including a magneto-optical recording medium) but also to an optical recording medium, and the support is not limited to a tape, but may be a disk medium such as a magnetic disk or an optical disk. It can also be used for recording media.

[0030]

In a conventional lubricant, a compound having a relatively large polarity such as a carboxylic acid or a carboxylic acid amine salt has a small friction coefficient but tends to have poor still durability, and a relatively polar compound such as an ester compound. Small compounds have good still durability, but have a high coefficient of friction. In contrast, the perfluoropolyalkyl ether compound of the present invention has a relatively weak ester group, but has four polar groups per molecule as compared with the conventional lubricant. Many. Therefore, it has a small friction coefficient and excellent characteristics in still durability. In particular, when the perfluoropolyalkyl ether compound of the present invention is applied as a lubricant on a carbon film layer, four ester groups of the general formula (1) of the polar group of the lubricant molecule are adsorbed on the carbon film layer, A highly durable lubricant layer can be formed by the cohesive force between the hydrophobic groups. In addition, while a fluorine-based solvent is essential for applying a conventional fluorine-containing lubricant, the perfluoropolyalkyl ether-based compound of the present invention requires application using a hydrocarbon-based solvent such as toluene and acetone. Since it is possible, the load on the environment is small, which is preferable.

As described above, the magnetic recording medium using the perfluoropolyalkyl ether compound of the present invention as a lubricant maintains excellent lubricity under various conditions of use and maintains a lubricating effect for a long time. , Excellent running properties, wear resistance, durability and the like.

[0032]

The present invention will be further described below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

Synthesis Example 1 (C ₁₈ H ₃₇ —CH (COOC ₁₈ H
_{37) CH 2 COO-Rf-} OCOCH 2 CH (COOC 18
H ₃₇ ) -Synthesis of C ₁₈ H ₃₇ ) A compound containing octadecylsuccinic anhydride as a succinic acid derivative containing an R ¹ group in the general formula (1) and containing a fluoropolyether group (Rf) in the general formula (1) Was used, and octadecyl alcohol was used as the compound containing an R ² group in the general formula (1) to synthesize the perfluoropolyalkyl ether compound of the present invention. The synthesis procedure is shown below.

Octadecyl succinic anhydride C ₁₈ H ₃₇ C ₄
10.0 g of H ₃ O ₃ and 28.4 of Z-dol 2000
g were mixed and refluxed at 150 ° C. for 3 hours. After completion of the reaction, the reaction product was dissolved in 200 ml of toluene, and 10% N
300 ml of an aOH aqueous solution was added, and the mixture was vigorously shaken. The resulting white solid (the target Na salt) was suction-filtered with a glass filter. Further, twice with 240 ml of water, 200 ml of toluene
Wash the white solid on a glass filter once with ml.
By this operation, octadecyl succinic anhydride as a raw material could be removed. Next, put the white solid in a separating funnel,
300 ml of toluene and 300 ml of 7.2% hydrochloric acid were added, and the mixture was separated, washed and desalted. Then add 7.2% hydrochloric acid (300 ml)
The mixture was washed twice with an aqueous sodium chloride solution twice, and the toluene phase was recovered and dried over magnesium sulfate. After 1 hour, the mixture was filtered and the toluene phase was concentrated. Subsequently, the recovered product was purified by column chromatography. Column conditions are: column packing: silica gel, column temperature: room temperature, eluent: toluene and ethyl acetate 10% toluene 90%
Is a mixed solvent. The target substance elutes when a mixed solvent of 10% ethyl acetate and 90% toluene is used. 1 collected
9 g. The recovered material was analyzed by IR.
_{18 H 37 -CH (COOH) CH} 2 COO-Rf-OCO
_{CH 2 CH (COOH) -C 18} H 37 (Rf is a a fluoropolyether group having an average molecular weight 2000) was found to have a. Furthermore, C ₁₈ H ₃₇ -C of purified 19g
H (COOH) CH ₂ COO-Rf-OCOCH ₂ CH
(COOH) -C ₁₈ H ₃₇ in thionyl chloride 3.3g and the mixture was refluxed for 2 hours. After the completion of the reaction, the reaction product was concentrated to recover the target product. The collected product was IR analysis, formula _{C 18 H 37 -CH (COCl)} CH 2 COO-Rf-OC
It was found to have an _{OCH 2 CH (COCl) -C 18} H 37.

Further, purified C ₁₈ H ₃₇ —CH (COC
_{l) CH 2 COO-Rf-} OCOCH 2 CH (COCl)
-Add 4.8 g of octadecyl alcohol to C ₁₈ H ₃₇ ,
Refluxed for 2 hours. After the completion of the reaction, the reaction product was dissolved in 200 ml of toluene, and separated and washed twice with an aqueous sodium chloride solution in a separating funnel to collect toluene and dried over magnesium sulfate. After 1 hour, the mixture was filtered and the toluene phase was concentrated. Subsequently, the recovered product was purified by column chromatography. The column conditions are as follows: column packing: silica gel; column temperature: room temperature; eluent: toluene. The desired product elutes when toluene is used. Collected material is 10g
And the recovery was about 25%. The recovered product was analyzed by IR to find that the general formula C ₁₈ H ₃₇ —CH (COOC ₁₈ H ₃₇ )
CH ₂ COO-Rf-OCOCH ₂ CH (COOC
It was found to have a _{18 H 37) -C 18 H 37} . FIG.
The R analysis result is shown.

Synthesis Example 2 (C ₁₆ H ₃₃ —CH (COOC
_{2 H 5) CH 2 COO-} Rf-OCOCH 2 CH (COOC
₂ H ₅₎ Synthesis of -C ₁₆ H ₃₃₎ using hexadecyl succinic anhydride in general formula (1) as succinic acid derivatives containing R ¹ group, the general formula a perfluoropolyether group (Rf) in (1) The perfluoropolyalkyl ether-based compound of the present invention was synthesized using Z-dol 2000 as the compound to be contained and ethyl alcohol as the compound containing the R ² group in the general formula (1). The synthesis procedure is shown below.

Hexadecyl succinic anhydride C ₁₆ H ₃₃ C ₄
10.0 g of H ₃ O ₃ and 28.8 of Z-dol 2000
g were mixed and refluxed at 150 ° C. for 3 hours. After completion of the reaction, the reaction product was dissolved in 200 ml of toluene, and 10% N
300 ml of aOH aqueous solution was added and shaken vigorously. The resulting white solid (the target Na salt) was suction-filtered with a glass filter. Two times with 240 ml of water, 200 m of toluene
Wash the white solid on a glass filter once with l. By this operation, hexadecyl succinic anhydride as a raw material could be removed. Next, the white solid was placed in a separatory funnel, and 300 ml of toluene and 300 ml of 7.2 HCl were added, and the mixture was separated and washed, and desalted. Further, the mixture was separated and washed twice with 300 ml of 7.2 HCl and twice with an aqueous solution of sodium chloride, and the toluene phase was recovered and dried with magnesium sulfate. After 1 hour, the mixture was filtered and the toluene phase was concentrated. Subsequently, the recovered product was purified by column chromatography. Column conditions are: column packing: silica gel, column temperature: room temperature,
Eluent: toluene and ethyl acetate 10% toluene 90
% Of the mixed solvent. The target substance elutes when a mixed solvent of 10% ethyl acetate and 90% toluene is used. The recovered material was 19 g. The recovered product was analyzed by IR to find that the general formula C ₁₆ H ₃₃ —CH (COOH) CH ₂ COO-Rf-OC
_{OCH 2 CH (COOH) -C 16} H 33 (Rf is a a perfluoropolyether group having an average molecular weight 2000) was found to have a. Further, purified C ₁₆ H ₃₃ -CH
(COOH) CH ₂ COO-Rf-OCOCH ₂ CH (C
OOH) -C thionyl chloride ₁₆ H ₃₃ 19.5 g 3.5
g was added and refluxed for 2 hours. After the completion of the reaction, the reaction product was concentrated to recover the target product. The collected product was analyzed by IR.
Formula _{C 16 H 33 -CH (COCl)} CH 2 COO-Rf
It was found to have an _{-OCOCH 2 CH (COCl) -C 16} H 33.

Further, purified C ₁₆ H ₃₃ —CH (COC
_{l) CH 2 COO-Rf-} OCOCH 2 CH (COCl)
5.0 g of excess ethyl alcohol was added to -C ₁₆ H ₃₃ ,
Refluxed for 2 hours. At the end of the reaction, the excess ethyl alcohol is evaporated. Thereafter, the reaction product was dissolved in 200 ml of toluene, and the solution was added with a sodium chloride aqueous solution in a separating funnel.
The separation and washing were repeated once, and the toluene phase was recovered and dried over magnesium sulfate. After 1 hour, the mixture was filtered and the toluene phase was concentrated. Subsequently, the recovered product was purified by column chromatography. Column conditions are as follows: column packing: silica gel, column temperature: normal temperature, eluent: toluene. The desired product elutes when toluene is used. Collected material is 10g
And the recovery was about 25%. The recovered product was analyzed by IR to find that the general formula C ₁₆ H ₃₃ —CH (COOC ₂ H ₅ ) C
_{H 2 COO-Rf-OCOCH 2} CH (COOC 2 H 5) -
It was found to have a C ₁₆ H _33.

If the same technique as described above is adopted, the R ¹ group, arbitrary fluoropolyether group (Rf) and R ² group in the general formula (1) are appropriately set, and the perfluoropolyalkyl of the present invention is obtained. An ether compound can be synthesized. Specific examples are shown in Table 1 below.

[0040]

[Table 1]

Examples 1 to 29 Using the raw materials shown in Tables 2 and 3 below, a perfluoropolyalkyl ether compound of the present invention was synthesized in the same manner as in the above-mentioned synthesis example. Tested.

[0042]

[Table 2]

[0043]

[Table 3]

Comparative Examples 1 to 5 Compounds having the structures shown in Table 4 below were used as lubricants in the following tests.

[0045]

[Table 4]

Preparation of Sample Tape Co was vapor-deposited on a 7.0 μm thick polyethylene terephthalate film to form a magnetic layer composed of a 180 nm-thick metal magnetic thin film. Next, a carbon film layer having a thickness of about 8 nm was formed on the magnetic layer using a magnetron sputtering apparatus. Next, a 0.5 μm thick back coat layer made of carbon and polyurethane resin was formed on the surface of the polyethylene terephthalate film opposite to the surface on which the magnetic layer was formed. Subsequently, the perfluoropolyalkyl ether-based compounds of the present invention according to Examples 1 to 29 and the compounds of Comparative Examples 1 to 5 were individually dissolved in toluene, and these compounds were individually applied to the surface of the carbon film layer. Coating was performed so that the coating amount was 5 mg / m ² . The obtained magnetic recording medium was cut into a 6.35 mm width to obtain a sample tape of each of the examples and comparative examples.

Evaluation of durability and running property Using each sample tape produced as described above,
The coefficient of friction was measured at a temperature of 40 ° C. and a relative humidity of 80%, the still durability was measured at a temperature of −5 ° C., and the shuttle durability was measured at a temperature of 40 ° C. and a relative humidity of 20%. The results are shown in Tables 5 and 6 below. These conditions are considered to be the strictest usage conditions. In addition, a commercially available digital video camcorder (trade name: VX1000, manufactured by Sony Corporation) was used for measuring the still durability and the shuttle durability.

(1) Method of measuring friction coefficient The friction coefficient was measured in a constant temperature bath at a temperature of 40 ° C. and a relative humidity of 8 ° C.
Control the sample tape to 0% and place the sample tape in the friction coefficient
The measurement was performed after running 00 times. In addition, the numerical value after running 100 times was described in the table as a friction coefficient. (2) Still Durability Measuring Method Still durability was measured in a thermostat at −5 ° C., and the time until the reproduction output dropped by 3 dB was measured. (3) Shuttle durability measurement method The shuttle durability was measured by setting the temperature in a thermostat at 40 ° C and a relative humidity of 20 ° C.
%, The sample tape was run 100 times in the Play mode for 60 minutes, and after running 100 times, the reproduction output was reduced by dB from the initial output.

Evaluation of Solubility in Solvent The lubricants used in Examples 1 to 25 and Comparative Example 3 were examined for their solubility in ethanol, acetone and toluene. The evaluation was evaluated as ○ when easily soluble in each solvent, and × when lubricant was not necessary for the solvent. The results of the solubility evaluation of each lubricant are shown in Table 7 below.

[0050]

[Table 5]

[0051]

[Table 6]

[0052]

[Table 7]

From the above results, by using the perfluoropolyalkyl ether compound of the present invention as a lubricant for a magnetic recording medium, the friction coefficient and the stillness can be obtained even under various use conditions such as high temperature and high humidity, high temperature and low humidity, and low temperature. It can be seen that there is very little deterioration in durability or shuttle durability, and very good results are obtained.

[0054]

The perfluoropolyalkyl ether compound of the present invention is particularly useful as a lubricant for magnetic recording media. Further, if the above-mentioned perfluoropolyalkyl ether compound is used as a lubricant for a recording medium,
A recording medium that maintains excellent lubricity under various use conditions, maintains a lubricating effect for a long time, and can provide excellent running properties, abrasion resistance, durability, and the like.

[Brief description of the drawings]

FIG. 1 shows the target compound of Synthesis Example 1 (perfluoropolyalkyl).
C) which is an ether compound) ₁₈H₃₇CH (COOC₁₈
H₃₇) CH_TwoCOO-Rf-OCOCH_TwoCH (COOC
₁₈H₃₇) -C₁₈H₃₇FIG. 6 is a diagram showing an IR analysis result of the present invention.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G11B 5/725 G11B 5/725 // C10N 30:00 C10N 30:00 Z 30:06 30:06 40: 18 40:18 (72) Inventor Kenichi Kurihara 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (72) Inventor Ken Kobayashi 6-35, Kita-Shinagawa, Shinagawa-ku, Tokyo Sonny shares Inside the company (72) Inventor Hiroshi Iwamoto 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation (72) Inventor Toshinori Tsuboi Inside 7-35, Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation F-term (Reference) 4H006 AA01 AA03 AB61 AB91 BE51 BM10 BM71 BP10 KA06 KA14 4H104 BD07A CD04A LA03 LA20 PA16 4J002 CH051 GS00 GT00 4J005 BD02 5D006 AA01 AA05 FA02 FA06

Claims (4)

[Claims] 1. A following general formula (1): ## STR1 ## ^{R 1 -CH (COOR 2) CH} 2 COO-Rf-OCOCH 2 CH (COOR 2) -R 1 ... (1) ( In the formula, R ¹ Represents a saturated or unsaturated aliphatic hydrocarbon group having 6 to 30 carbon atoms, and Rf has an average molecular weight of 5
Indicates fluoropolyether group from 00 to 6,000, R ²
Is a saturated or unsaturated aliphatic hydrocarbon group having 1 to 30 carbon atoms (but may have a ketone group in part), or a fluoroalkyl group having 1 to 30 carbon atoms, fluoro It represents an alkenyl group or a fluoroether group. A perfluoropolyalkyl ether compound represented by the formula: Wherein the following formula (1): ## STR2 ## ^{R 1 -CH (COOR 2) CH} 2 COO-Rf-OCOCH 2 CH (COOR 2) -R 1 ... (1) ( In the formula, R ¹ Represents a saturated or unsaturated aliphatic hydrocarbon group having 6 to 30 carbon atoms, and Rf has an average molecular weight of 5
Indicates fluoropolyether group from 00 to 6,000, R ²
Is a saturated or unsaturated aliphatic hydrocarbon group having 1 to 30 carbon atoms (but may have a ketone group in part), or a fluoroalkyl group having 1 to 30 carbon atoms, fluoro It represents an alkenyl group or a fluoroether group. A lubricant for recording media comprising a perfluoropolyalkyl ether compound represented by the formula (1). 3. A recording medium in which a recording layer and a lubricant layer made of a lubricant are formed at least sequentially on a support, wherein the lubricant has the following general formula (1): ^1- CH (COOR ² ) CH ₂ COO-Rf-OCOCH ₂ CH (COOR ² ) -R ¹ (1) (wherein, R ¹ is a saturated or unsaturated aliphatic carbon having 6 to 30 carbon atoms. Represents a hydrogen group, and Rf has an average molecular weight of 5
Indicates fluoropolyether group from 00 to 6,000, R ²
Is a saturated or unsaturated aliphatic hydrocarbon group having 1 to 30 carbon atoms (but may have a ketone group in part), or a fluoroalkyl group having 1 to 30 carbon atoms, fluoro It represents an alkenyl group or a fluoroether group. A recording medium comprising a perfluoropolyalkyl ether compound represented by the formula (1): 4. The recording medium according to claim 3, wherein said recording layer is a magnetic layer, and said recording medium is a magnetic recording medium.