JPS63301848A - Benzoic acid ester derivative and magnetic recording medium - Google Patents

Abstract

NEW MATERIAL:A benzoic acid ester derivative of formula I (m, n, j are integers respectively where 0<=m<=5, 1<=n<=12, 1<=j<=5). EXAMPLE:Pentadecafluoro-octyl 3-aminobenzoate. USE:It is used as a lubricant. It manifests excellent lubricity under any difficult conditions. The magnetic recording medium in which the compound is used as a lubricant shows improved running properties and increased durability. PREPARATION:For example, the reactions are conducted as shown in the equations to give the compound of formula I. The esterification reaction between benzoyl chloride and a perfluoroalcohol is preferably carried out in a solvent such as toluene or chloroform in the presence of a base such as pyridine or triethylamine, usually with stirring at room temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to benzoic acid ester derivatives useful as lubricants.

Furthermore, the present invention relates to magnetic recording media such as magnetic tapes and magnetic disks, and particularly relates to magnetic recording media using the benzoic acid ester derivative as a lubricant.

[Summary of the invention]

The present invention aims to provide a new benzoic acid ester derivative having excellent lubricating properties by introducing an amino group into a benzoic acid perfluoroalkyl ester, which is an ester compound of benzoic acid and a perfluoroalcohol.

Furthermore, the present invention provides a magnetic recording medium having a magnetic layer on a non-magnetic support, which has excellent running properties and durability under all usage conditions by using the above-mentioned benzoic acid ester derivative as a lubricant. The objective is to provide a magnetic recording medium that exhibits wear resistance and durability.

[Conventional technology]

For example, there are so-called metal thin film type magnetic recording media in which a ferromagnetic metal material is deposited on a non-magnetic support by a method such as vapor deposition and this is used as a magnetic layer, and a magnetic recording medium in which extremely fine magnetic particles and a resin binder are used as a magnetic layer. The coating film of the magnetic paint containing the magnetic material was used as the magnetic layer. In so-called coating-type magnetic recording media, the surface of the magnetic layer has extremely good smoothness, so the actual contact area with sliding members such as magnetic heads and guide rollers becomes large, and the coefficient of friction increases. Adhesion phenomenon (so-called sticking)
There are many problems with durability, running performance, etc., such as the tendency to occur.

Therefore, the use of various lubricants has been considered to improve this problem, and attempts have been made to suppress the coefficient of friction by adding higher fatty acids or their esters to the magnetic layer, or by top-coating it. ing.

By the way, the lubricant used for this magnetic recording medium includes:
Currently, there are very strict requirements depending on the application, and it is difficult to meet these requirements sufficiently with conventional lubricants.

In other words, lubricants used for magnetic recording media must: i) have excellent low-temperature properties to ensure the desired lubrication effect even when used in particularly cold regions, and ii) have problems with spacing with the magnetic head. Therefore, it is required that it can be applied extremely thinly, and that sufficient lubricity is exhibited even in that case, and (iii) that the effect lasts for a long time. However, fatty acids and their esters, etc. Under low temperature conditions below CC, it tends to freeze and solidify, impairing its function as a lubricant.

[Problem that the invention seeks to solve]

As described above, in the field of magnetic recording media, practical characteristics such as runnability and durability remain unsatisfactory due to insufficient lubricant performance.

The present invention was proposed in view of the above-mentioned conventional situation, and aims to develop a novel compound that exhibits excellent lubricity under any usage conditions.

Furthermore, the present invention aims to provide a magnetic recording medium that maintains lubricity under any usage conditions and maintains the lubrication effect over a long period of time. The purpose is to provide.

(Means for Solving the Problems) As a result of intensive research into achieving the above-mentioned purpose, the present inventors found that a benzoic acid ester derivative synthesized for the first time by the present inventors is suitable for this purpose. This discovery led to the completion of the present invention.

That is, the present invention is based on the general formula (where m, n, and j each represent an integer, and O≦m
≦5, 1≦n≦12, 1≦j≦5. ) A novel benzoic acid ester derivative represented by:

Furthermore, the magnetic recording medium of the present invention is a magnetic recording medium having at least a magnetic layer on a non-magnetic support, and has the general formula (where m, n, and J each represent an integer, and 0≦ m
≦5, 1≦n≦12. l≦j≦5. ) is characterized by having a benzoic acid ester derivative represented by:

The benzoic acid ester derivative of the present invention is one in which an amino group is introduced into the benzene ring present at the end of an ester compound of benzoic acid and perfluorocarbon alcohol.

Here, the perfluoroalkyl group (-C-h-0+) introduced by esterification has a carbon number n of 1-12.
If the carbon number n is O, the lubricity due to the introduction of fluorine will be lost. There is no particular restriction on the upper limit, but if the number of carbon atoms exceeds 12, handling problems will occur, for example, it will be difficult to apply a very thin layer.

The perfluoroalkyl group may be linear or monobranched.

The number m of carbon atoms in the methylene group is determined by the type of perfluoroalcohol used for esterification and can be any number, but if the number m of carbon atoms is too large, the lubricating effect of the perfluoroalkyl group will be reduced. Since there is a possibility that the number of carbon atoms may decrease, it is preferable to limit the number to 5 or less. Note that this methylene group may not be introduced, that is, the number of carbon atoms m may be zero.

On the other hand, the number of amino groups introduced into the benzene ring is 1 to 5. The amino group may be introduced at any of the ortho, meta, and para positions relative to the carboxyl group of benzoic acid.

The benzoic acid ester derivatives of the present invention are all new compounds that have not been published in any literature, and include benzoic acid and general 2C-h, 1
．． +(CL)IIol ((in the formula, m is an integer of 0 to 5, and n is an integer of 1 to 12) is used as a starting material and is easily synthesized through the following reaction.

Reaction route l Here, the esterification reaction between benzoyl chloride and perfluoroalcohol proceeds in the presence of a base such as pyridine or triethylamine in a solvent such as toluene or chloroform. Although it does not necessarily depend on the type and other conditions, it usually progresses easily by stirring at room temperature.

Alternatively, it can also be synthesized through the following reaction route.

Reaction route 2 On the other hand, the magnetic recording medium of the present invention contains the above-mentioned benzoic acid ester derivative as a lubricant.

Here, in the magnetic recording medium to which the present invention is applied, a magnetic coating film is formed as a magnetic layer by first applying a magnetic coating material to the surface of a non-magnetic support.

Examples include so-called coated magnetic recording media.

In the coated magnetic recording medium, any conventionally known magnetic powders, resin binders, etc. constituting the non-magnetic support and the magnetic coating can be used, and there are no limitations in any way.

To illustrate, examples of non-magnetic supports include polyesters, polyolefins, cellulose derivatives, vinyl resins, polyimides, and polyamides.

These include polymer supports made of polymer materials such as polyamides and polycarbonates, metal substrates made of aluminum alloys, titanium alloys, etc., ceramic substrates made of alumina glass, glass substrates, and the like.

The form is not limited at all, and may be in any form such as a tape, a disk, a sheet, or a drum.Furthermore, this nonmagnetic support has fine particles in order to control its surface properties. The surface may be subjected to surface treatment to form irregularities.

As the magnetic powder, γ-Fe□08. Cobalt deposited γ−
Ferromagnetic iron oxide particles such as Fetus, ferromagnetic chromium dioxide particles, ferromagnetic metal particles made of metals such as Fe, Co, and Ni or alloys containing these, hexagonal plate-shaped hexagonal ferrite fine particles, etc. Illustrated.

Vinyl chloride and vinyl acetate are used as resin binders.

Examples include polymers such as vinyl alcohol, vinylidene chloride, acrylic esters, methacrylic esters, styrene, butadiene-acrylonitrile, copolymers of two or more of these, polyurethane resins, polyester resins, and epoxy resins. Hydrophilic polar groups such as sulfonic acid groups, carboxyl groups, and phosphoric acid groups may be introduced into these binders in order to improve the dispersibility of the magnetic powder.

In addition to the above-mentioned magnetic powder and resin binder, the magnetic coating film contains additives such as a dispersant, an abrasive agent, and an antistatic agent.

A rust preventive agent or the like may be added.

The benzoic acid ester derivative can be incorporated into such a coating type magnetic recording medium, such as by adding it internally to the magnetic coating, by top-coating the surface of the magnetic coating, or by using a combination of both.

When the benzoic acid ester derivative is internally added to the magnetic coating film, it is added in an amount of 0.2 to 20 parts by weight based on 100 parts by weight of the resin binder.

When a benzoic acid ester derivative is top coated on the surface of a magnetic coating film, the coating amount is 0.5■/rd to 10
Preferably 0 tsg/rrf, ll11g
/rrr to 20 mg/nf is more preferable.

When applying a top coat with a benzoate ester derivative, the method for applying it is to dissolve the benzoate ester derivative in a solvent and apply or spray the resulting solution, or conversely, to apply a top coat to the magnetic recording medium in this solution. All you have to do is soak it.

The present invention can also be applied to metal TRM type magnetic recording media.

In this case as well, the applicable non-magnetic support and metal magnetic thin film of the metal thin film type magnetic recording medium are not limited at all, and any conventionally known ones can be used.

For example, the same non-magnetic support as used in the coating-type magnetic recording medium described above can be used. In this case, if a rigid substrate such as Affi plywood is used as the non-magnetic support and used as a so-called hard disk, the surface of the substrate may be coated with an oxide film such as alumite treatment or N1
-The surface may be hardened by forming a P film or the like.

Metal magnetic mH is formed as a continuous film using PVD methods such as plating, sputtering, and vacuum evaporation.
Metals such as Fe, Co, Ni, and C.

-Ni alloy, Co-Pt alloy, Co-N1-PL alloy, Fe-Co alloy, Fe-Ni alloy, Fe-C
o-Ni alloy Fe-N1-B alloy, Fe-Co-B
Examples include an in-plane magnetization recording metal magnetic II film made of a Fe-Co-Ni-B-based alloy, a perpendicular magnetization recording metal magnetic thin film such as a Co-Cr alloy thin film, or a Co-0 system Ti4 film. Ru.

In particular, in the case of in-plane magnetization recording metal magnetic thin films, Bi, Sb, Pb, Sn, and Ga are preliminarily deposited on a nonmagnetic support.

A base film of a low melting point nonmagnetic material such as In, Ge, St, T1, etc. is formed in advance, and a metal magnetic material is vapor-deposited or sputtered from the perpendicular direction, and these low melting point nonmagnetic materials are diffused into the magnetic metal 1) 1i. Alternatively, the orientation may be eliminated to ensure an in-plane method, and the coercive force may be improved.

Further, in the case of a hard disk as described above, a hard protective film such as a carbon film, a diamond-like carbon film, a chromium oxide film, or an SiO□ film may be formed on the surface of the metal magnetic thin film.

As a method for making such a metal thin film type magnetic recording medium contain the benzoate ester derivative, there may be mentioned a method of top-coating the surface of the metal magnetic thin film or the surface of the protective film. In this case, the coating amount of the benzoic acid ester derivative is preferably 0.5 mg/po to 100 .mu./po, more preferably 11 g/% to 20 .mu./po.

The above-mentioned benzoic acid ester derivatives may be used alone as a lubricant for magnetic recording media, but may also be used in combination with conventionally known lubricants. Alternatively, perfluoroalkyl carboxylic acid ester.

carboxylic acid perfluoroalkyl ester 1 perfluoroalkylcarboxylic acid perfluoroalkyl ester,
Alternatively, it can also be used in combination with these derivatives.

Furthermore, in order to cope with more severe conditions and maintain the lubricating effect, an extreme pressure agent may be used in combination at a weight ratio of about 30:0 to about 70:30.

Extreme pressure agents act to prevent friction and wear by reacting with metal surfaces due to Fe friction heat caused by partial metal contact in the boundary lubrication region and forming a reaction product film. There are phosphorus-based extreme pressure agents, sulfur-based extreme pressure agents, and halogen-based extreme pressure agents.

Any of organometallic extreme pressure agents, composite extreme pressure agents, etc. can be used.

Moreover, in addition to the above-mentioned lubricants and extreme pressure agents, a rust preventive agent may be used in combination as necessary.

As the rust preventive agent, any of those normally used as a rust preventive agent for this type of magnetic recording medium can be used, such as phenols and naphthols.

Quinones 5Heterocyclic compounds containing a nitrogen atom, heterocyclic compounds containing an oxygen atom, heterocyclic compounds containing a sulfur atom, and the like.

The rust preventive agent may be used in combination with a lubricant containing a benzoic acid ester derivative, but it is most effective when applied in two or more layers, such as applying a rust preventive layer and then a lubricant layer. is high.

By the way, in both the above-mentioned coating type magnetic recording medium and metal thin film type magnetic recording medium, a magnetic coating film as a magnetic layer,
In addition to the metal magnetic thin film, a bank coat layer, an undercoat layer, etc. may be formed as necessary.

For example, the back coat layer is formed by coating the same resin binder as the magnetic coating film, with the addition of carbon-based fine powder for imparting conductivity and an inorganic pigment for controlling surface roughness.

In the present invention, the above-mentioned benzoic acid ester derivative is internally added to the back coat layer as a lubricant.

It may be contained in a top coat, or various combinations are possible, such as adding a benzoic acid ester derivative internally as a lubricant to the magnetic coating film, metal magnetic yI film, and back coat layer and top coating them.

[Effect]

Benzoic acid ester derivatives, in which amine groups are introduced into benzoic acid perfluoroalkyl esters, exhibit good lubricating action and reduce the coefficient of friction. Moreover, this lubricating effect is not impaired even under severe conditions such as low temperatures.

A magnetic recording medium using this benzoate ester derivative as a lubricant has improved running properties and durability due to the lubricating action of the benzoate ester derivative.

〔Example〕

Hereinafter, specific examples of the present invention will be described, but it goes without saying that the present invention is not limited to these examples.

First, a synthesis example of a benzoic acid ester derivative will be shown.

Commercially available benzoic acid chloride from Kizoku Masue was added dropwise to an anhydrous toluene solution containing pentadecafluorooctatotool and pyridine over 30 minutes, and after completion of the reaction, the reaction was allowed to proceed at room temperature for 1 hour. after that,
After thoroughly washing the reaction solution with water to remove the solvent, benzoic acid pentadecafluorooctyl ester was distilled under reduced pressure. The obtained benzoic acid pentadecafluorooctyl ester is
The yield was 92%, and the boiling point was 116'C/1 mHg.

This ester was mixed with concentrated sulfuric acid, and fuming nitric acid was added dropwise over 30 minutes. At this time, the reaction temperature was kept below 5° C. After the completion of the dropping of fuming nitric acid, the mixture was placed in ice water, thoroughly washed with water, and the reaction product was recrystallized from methanol. The obtained reaction product had a yield of 83% and a melting point of 48-49.
It was ℃.

This nitrated product was dissolved in ethanol, hydrochloric acid and tin were added, and the reaction was carried out for 2 hours at a reaction temperature of 65 to 70°C. After completion of the reaction, the solvent was concentrated, and after cooling, the precipitate was filtered out. This is dissolved in hot water, made alkaline by adding a caustic soda solution, and the deposited precipitate is filtered out. This is recrystallized from methanol. The obtained crystals had a yield of 78% and a melting point of 68-6.
The temperature was 9°C.

The mass spectrum and infrared absorption spectrum of this compound are shown in Figures 1 and 2. In the mass spectrum shown in Part 1 above, a molecular ion peak is seen at 519, which is consistent with the calculated value of C+5)IsF+5NOt. do. Also, in the infrared absorption spectrum shown in Figure 2, 3350.345
Stretching vibration of amino group at 0C11-', 1720cm-'
The structure of the reaction product obtained by the above synthesis was determined from the carbonyl stretching and contraction at 1360 to 1050C1l-', the C-F stretching at 1360 to 1050C1l-', and the in-plane bending vibration of the amino group at 1605cm+-'. Ta. The above reaction product is
It was 3-aminobenzoic acid pentadecafluorooctyl ester having the structure shown below.

The reaction route of this synthesis example is shown in the following formula.

Commercially available 2,4-dinitrobenzoic acid and phosphorus pentachloride were mixed at 130%
React at -140℃ for 3 hours, and first perform POC using a water pump.
After removing Is, 2,4-dinitrobenzoic acid chloride was distilled under reduced pressure using a vacuum pump. The obtained 2,4-dinitrobenzoic acid chloride had a yield of 92% and a boiling point of 143-145.
°C/0.5 sang.

This acid chloride was reacted with pentadecafluorooctyl alcohol and pyridine in the same manner as in Synthesis Example 1 to obtain 2,4-dinitrobenzoic acid pentadecafluorooctyl ester. The obtained 2°4-dinitrobenzoic acid pentadecafluorooctyl ester had a yield of 80% and a melting point of 80 to 81°C.

This dinitrobenzoic acid ester was dissolved in ethanol, hydrochloric acid and tin were added, and the mixture was reacted at 65 to 70°C for 3 hours. After concentrating the solvent and cooling, the precipitate was filtered off, dissolved in ethanol, made alkaline by adding caustic soda, and ice water was added to form a precipitate, which was recrystallized from a mixed solvent of n-hexane and ethyl acetate.

The yield of the obtained crystals was 45%, and the melting point was 116-117°C.
Met.

The mass spectrum and infrared absorption spectrum of this compound are shown in Figures 3 and 4.
A molecular ion peak is seen at 534 in the vector. Also, in the infrared absorption spectrum shown in Figure 4, 3340.343
Amino group expansion and contraction at 0C1-', carbonyl expansion and contraction at 1680C11-', C-F at 1340-106106O'
A stretching vibration was observed in 1605C11-', and an in-plane bending vibration of the amino group was observed in 1605C11-', so the structure of the reaction product obtained by the above synthesis was determined. The reaction product was 2,4-diaminobenzoic acid pentadecafluorooctyl ester having the structure shown below.

The reaction route of this synthesis example is shown in the following formula.

According to the synthesis method 1 and the synthesis method shown in Synthesis Example 1 and Synthesis Example 2 above, benzoic acid perfluoroalkyl esters shown in Table 1 were synthesized by changing the types of perfluoroalcohol and dinitrobenzoic acid used.

Table 1 The magnetic recording media shown below were prepared using the compounds shown in Table 1.

First, an example was conducted by applying the present invention to a coated magnetic recording medium.

1 Parts by weight of Co deposited on the opening I Fezes too Parts by weight Vinyl chloride-vinyl acetate copolymer 10.5 parts by weight (manufactured by U, C, C, V A G H) Polyurethane resin 1000 parts by weight (manufactured by Nippon Polyurethane Co., Ltd. M -5033) Carbon (antistatic agent)
5 parts by weight lecithin (dispersion side)
1 part by weight methyl ethyl ketone
150 parts by weight methyl isobutyl ketone 1
50 parts by weight The above composition was used as a basic composition, and 1.5 parts by weight of Compound 1 in Table 1 was added as a lubricant to the basic composition, mixed in a ball mill for 24 hours, taken out through a filter, and further 30 by adding 4 parts by weight of curing agent.
Stir for a minute. This magnetic paint was applied onto a polyethylene terephthalate base having a thickness of 12 μm so that the thickness after drying would be 5 μm, and after magnetic field orientation, it was dried and rolled up. This was calendered and cut into 1/2 inch width to produce sample tapes.

A sample tape was prepared in the same manner as in Example 1 except that Compound 2 in Table 1 was added in place of Compound 1 in Example 1.

A sample tape was prepared in the same manner as in Example 1 except that Compound 3 in Table 1 was added in place of Compound 1 in Example 1.

Backyard ■Work In Example 1, a sample tape was prepared in the same manner as in Example 1 except that Compound 4 in Table 1 was added in place of Compound 1.

A sample tape was prepared in the same manner as in Example 1 except that Compound 5 in Table 1 was added in place of Compound 1 in Example 1.

For each sample tape produced as described above, the friction coefficient and stick-slip were measured before and after aging at a temperature of 25° C., a relative humidity of 60%, and a temperature of 40° C. and a relative humidity of 80%. Also, for each sample tape, the temperature was 25°C.
The friction coefficient and still durability were also measured at a humidity of 60%, a temperature of -5°C, a temperature of 40°C, and a humidity of 30%.

The results are shown in Tables 2 and 3.

(Hereinafter in the margin) Table 2 (Hereinafter in the margin) Table 3 As is clear from Tables 2 and 3 above, by using benzoic acid perfluoroalkyl ester as a lubricant, the friction coefficient, still durability, etc. Very good results were obtained with no deterioration under various conditions.

Next, an example in which the present invention is applied to a metal thin film magnetic recording medium (hard disk, with underlayer film) will be described.

Implementation ■ First, N1-P with a thickness of 15 μm was applied as a non-magnetic metal underlayer.
Al-Mg alloy substrate on which a plating layer was formed (rILS1.
Prepare a sieve (5IIIfull, outer diameter 95cm, inner diameter 25cm),
On this plated layer, Bi was deposited by electron beam under the conditions of a pressure of I.times.10-'Torr and a substrate temperature of 150.degree. C. to form a low melting point metal base film having a thickness of 200 mm.

Then, a pressure of lXl0-'Tor
Co was deposited by electron beam at a substrate temperature of 150° C. to form a metal magnetic thin film with a thickness of 1000 μm, and a carbon protective film was further formed on this metal magnetic thin film by vacuum evaporation.

Finally, 3-aminobenzoic acid pentadecafluorooctyl ester prepared in Synthesis Example 1 (synthesis 1 in Table 1) was deposited on the surface of this carbon protective film as a lubricant.
A sample disk was prepared.

Synthetic compound 1 used as a lubricant in Example 6-
A sample disk was prepared in the same manner as in Example 1 except for the following.

A sample disk was prepared in the same manner as in Example 1, except that Composite 1 used as a lubricant in Cross Cliff Group Main Example 6 was replaced with Composite 3.

Craftsmanship A sample disk was prepared in the same manner as in Example 1, except that Compound 1 used as the lubricant in Example 6 was replaced with Compound 4.

Sample disks were prepared in the same manner as in Example 1, except that Composite 1 used as the lubricant in Example 6 was replaced with Composite 5.

Comparative Example 1 After forming a low melting point metal base film and a metal magnetic layer on an Affi-Mg alloy substrate on which an N1-P plating layer was formed by the same method as in Example 6, a carbon protective film was formed, and a carbon protective film was formed on top of the Affi-Mg alloy substrate. prepared a sample disk without applying lubricant.

For each of the sample disks obtained in Examples 1 to 5 and Comparative Example 1, the C3S characteristics were investigated using a contact start/stop (C3S) test performed by three people. Furthermore, the friction coefficient after completion of C5515000 cycles was investigated. The results are shown in Table 4.

Table 4 From Table 4, the C3S characteristics of each sample disk in which a carbon protective film was formed on the surface of the metal magnetic thin film and the compound shown in Table 1 was used as a lubricant on top of the carbon protective film were significantly improved. It can be seen that the durability has improved.

Further, an example in which the present invention is applied to a metal thin film type magnetic recording medium (flo disk, bead disk, without underlayer film) will be described.

1 application V] ↓ CO was deposited on a 14 μmq polyethylene terephthalate film by an oblique evaporation method to form a ferromagnetic metal thin film with a thickness of 1000 μm.

Next, on the surface of this ferromagnetic metal thin film, a compound l shown in Table 1 was applied.
is dissolved in a mixed solvent of freon and ethanol,
A sample tape was prepared by applying the sample tape in an amount of 5 g/nf and cutting it into a width of 8 mm.

Sample tape was prepared in the same manner as in Example 11 except that Compound 1 in Table 1 used as a lubricant was replaced by Compound 2.

Side 1 [Vl In Example 11, a sample tape was prepared in the same manner as in Example 11 except that Compound 1 in Table 1 used as a lubricant was replaced with Compound 3.

A sample tape was prepared in the same manner as in Example 11, except that Compound 1 in Table 1 used as a lubricant was replaced with Compound 4.

[In Example 11, a sample tape was prepared in the same manner as in Example 11, except that Compound 1 in Table 1 used as a lubricant was replaced with Compound 5.

For each sample tape produced as described above, the friction coefficient, still durability, and shuttle durability at temperatures of 25°C and -5°C were measured. Still durability was evaluated by evaluating the decay time for the output to -3 dB in a pause state. Shuttle durability was evaluated by running the shuttle for 2 minutes each time and determining the number of shuttle runs until the output decreased by 3 dB. In addition, as Comparative Example 2, a blank tape in which no lubricant was used was also measured. The results are shown in Table 5.

Table 5 As is clear from Table 5 above, by using benzoic acid perfluoroalkyl ester as a lubricant,
Very good results were obtained in terms of friction coefficient, still durability, etc., without deterioration under various conditions.

〔Effect of the invention〕

As is clear from the above explanation, the benzoic acid ester derivative of the present invention is a compound having extremely excellent lubricating properties, and can be said to be useful as a lubricant.

Furthermore, since the magnetic recording medium of the present invention has the above-mentioned benzoic acid ester derivative as a lubricant, it can maintain lubricity under any usage conditions, and can maintain its lubricity over a long period of time. can. therefore,
The magnetic recording medium of the present invention has excellent running properties and durability.

[Brief explanation of the drawing]

FIG. 1 is a mass spectrometry spectrum of an example of a benzoic acid ester derivative synthesized in a synthesis example of the present invention, and FIG. 2 is an infrared absorption spectrum thereof. FIG. 3 is a mass spectrometry spectrum of another example of the benzoic acid ester derivative synthesized in the synthesis example of the present invention, and FIG. 4 is its infrared absorption spectrum.

Claims (2)

[Claims] (1) General formula▲There are mathematical formulas, chemical formulas, tables, etc.▼ (However, in the formula, m, n, and j each represent an integer, and 0≦m
≦5, 1≦n≦12, 1≦j≦5. ) benzoic acid ester derivatives. (2) A magnetic recording medium that has at least a magnetic layer on a non-magnetic support, and has a general formula ▲ mathematical formula, chemical formula, table, etc. ▼ (However, in the formula, m, n, and j each represent an integer. represents, 0≦m
≦5, 1≦n≦12, 1≦j≦5. ) A magnetic recording medium comprising a benzoic acid ester derivative represented by: