JPS6345238A - Dicarboxylic acid ester derivative and lubricant containing same - Google Patents

Abstract

NEW MATERIAL:A dicarboxylic acid ester derivative shown by formula I (R is bifunctional hydrocarbon group; n>=3; j>=3). EXAMPLE:Fumaric acid dipentadecafluorooctyl ester. USE:Since the lubricant exhibits excellent lubricating effects only by applying the lubricant to the surface, the effects will not decrease even in use at low temperature and the lubricant is readily synthesized and handled, this lubricant is a lubricant applicable to a specific use such as magnetic recording material of ferromagnetic metallic thin film type, etc. PREPARATION:A dicarboxylic acid chloride shown by formula II is reacted with a perfluoroalcohol shown by formula III in the presence of a base to give a compound shown by formula I readily. The compound shown by formula II is obtained by converting a corresponding carboxylic acid to an acid chloride and reducing the acid chloride with aluminum lithium hydride.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a novel dicarboxylic acid ester derivative that exhibits good lubricating action even in a low temperature range and is useful as a lubricant. The present invention relates to a lubricant containing a derivative.

[1 Summary of the Invention] The present invention is based on the general formula % (wherein R is a divalent hydrocarbon group, and n≧3.
”≧0. ) It is an object of the present invention to provide a novel dicarboxylic acid ester derivative α which exhibits excellent lubricity under all conditions of use, and also to provide a lubricant containing this dicarboxylic acid ester derivative.

[Conventional technology]

Until now, many compounds have been known as lubricants, such as liquid lubricants typified by higher fatty acids and their esters, and solid lubricants typified by sorybdenum disulfide, and their uses are expanding.

For example, in a ferromagnetic metal film type magnetic recording medium in which a ferromagnetic metal material r1 is deposited on a polymer film by a method such as vapor deposition and this is used as a magnetic layer, the surface smoothness of the magnetic layer is extremely good. Because of this, the actual contact area is large, making it easier for adhesion phenomena (so-called sticking) to occur and increasing the coefficient of friction, which has many drawbacks in terms of durability and runnability, so various lubricants are used to improve these problems. The use of is being considered.

Lubricants used for such special uses have strict requirements for their properties depending on the use, and it is currently difficult for well-known lubricants to meet these requirements satisfactorily.

Taking the above-mentioned magnetic recording medium with a thin ferromagnetic metal film as an example, the lubricant used must have 1) excellent low-temperature properties to ensure the desired lubrication effect even when used in particularly cold regions; , ii) It can be applied extremely thinly since spacing loss with the air head is a problem, and even in that case, it has sufficient lubricity; iii) Its effect lasts for a long time even if it is applied only to the surface. etc. are required. On the other hand, liquid lubricants such as fatty acids and their esters often solidify or freeze at low temperatures of 0 to -5°C, making it impossible to fully develop their lubricating effects. . Furthermore, solid lubricants are not practical as lubricants for tape-shaped media (magnetic tapes), for example.

[Problem that the invention seeks to solve]

Therefore, the purpose of the present invention is to develop a new compound that maintains its adsorption properties and lubricity under any conditions of use, and that maintains its lubricating effect for a long period of time simply by applying it to the surface. The object of the present invention is to provide a lubricant suitable for use in ferromagnetic metal thin film type magnetic recording media.

[Means for solving problems]

As a result of intensive research to achieve the above-mentioned object, the present inventor found that a certain single dicarboxylic acid ester derivative, which was finally synthesized by the present inventor, is suitable for this purpose, and based on this knowledge, This invention was achieved.

That is, the present invention is based on the general formula % (wherein R is a divalent hydrocarbon group, and n≧3.
j≧0. ) The present invention provides a dicarboxylic acid ester derivative represented by the following formula, and further provides a lubricant containing this dicarboxylic acid ester ER8 form.

The divalent hydrocarbon group R of the dicarboxylic acid moiety of the dicarboxylic acid ester derivative represented by the above formula (1) may be linear or branched, and may further include a double bond, an aromatic ring, etc. However, the number of carbon atoms is preferably 6 or more.

Further, the number n of carbon atoms in the perfluoroalkyl group is preferably an integer of 3 or more (preferably 5 or more, as the lubricity is significant).

The dicarboxylic acid ester derivative represented by the above formula (+) can be easily obtained using a dicarboxylic acid quarride and a perfluoroalkyl group.

The above perfluoroalcohol can be synthesized by acid chloridizing the corresponding carboxylic acid and then reducing it with lithium aluminum hydride [Journal Op American Chemical Society-152693
(1953)). In addition, commercially available dicarboxylic acid chlorides were used, and those that were not commercially available were converted into acid chlorides using phosphorus pentachloride or thionyl chloride. The reaction formula is as follows.

2CJzn-+(CHz)mOH+ Cl0CRCO
CI-C-Fz-, + (Cll□);00CRCOO
CCHz) JC, F2-01...Formula (a) The dicarboxylic acid ester derivative described above may be used as a lubricant, but it can be used by mixing with a conventionally known lubricant, The band may be expanded.

The lubricants used include fatty acids or their metal salts;
Fatty acid amide, fatty acid ester, fatty alcohol or its alkoxide, fatty amine, polyhydric alcohol,
Sorbitan ester, manniathane ester, sulfurized fatty acid, aliphatic mercaptan, modified silicone oil, perfluoroalkyl ethylene oxide, perfluoropolyethers, higher alkyl sulfonic acid or its metal salt, perfluoroalkyl sulfonic acid or its ammonium salt, or Examples include gold, perfluoroalkylcarboxylic acids or metal salts thereof, and perfluoroalkylcarboxylic acid esters.

In particular, perfluoroalkylcarboxylic acid esters represented by -maxi〇, FZ,, 1COOR (in the formula, n represents an integer of 6 to 10, and R represents a hydrocarbon group having 1 to 25 carbon atoms) Since it also has good low-temperature properties, it is suitable for use in combination with the dicarboxylic acid ester derivatives mentioned above.

In addition, in order to cope with more severe usage conditions and maintain the lubricating effect, the weight ratio is 30 nia 0 to 70;
An extreme pressure agent may be used in combination at a blending ratio of about 0.

The extreme pressure agent mentioned above acts to prevent friction and wear by reacting with the metal surface due to the accompanying frictional heat when there is partial metal contact in the boundary lubrication area, and forming a reaction product film. Known examples include phosphorus-based extreme pressure agents, sulfur-based extreme pressure agents, halogen-based extreme pressure agents, organometallic extreme-pressure agents, and combination type extreme-pressure agents.

Specifically, examples of the phosphorus extreme pressure agent include tributyl phosphate, trioctyl phosphate, tri-2-ethylhexyl phosphate, trilauryl phosphate, trioleyl phosphate, dibutyl phosphate, and dioctyl phosphate. Phosphate esters such as di-2-ethylhexyl phosphate, dilauryl phosphate, dioleyl phosphate, tributyl phosphite, trioctyl phosphite, tri-2-ethylhexyl phosphite, trilauryl phosphite, trioleyl phosphite, dibutyl Phosphite esters such as phosphite, dioctyl phosphite, di-2-ethylhexyl phosphite, dilauryl phosphite, dioleyl phosphite, and dibutyl phosphate butylamine salts.

Dibutyl phosphate octylamine salt, dibutyl phosphate stearylamine salt, dioctyl phosphate butylamine salt, dioctyl phosphate octylamine salt, dioctyl phosphate laurylamine salt, dioctyl phosphate stearylamine salt, di-2-ethylhexylphosphate butylamine salt, di-2-ethyl Hexyl phosphate octylamine salt, di-2-ethylhexyl phosphate octylamine salt, di-2-
Ethyl hequinolphosphate stearylamine salt, dilaurylphosphate butylamine salt.

dilauryl phosphate octylamine salt, dilauryl phosphate traurylamine salt, dilauryl phosphate stearylamine salt, dioctyl phosphate butylamine salt, dioctyl phosphate octylamine salt,
Examples include phosphate ester amine salts such as dioleyl phosphate lauryl amine salt and dioleyl phosphate stearyl amine salt.

The above-mentioned sulfur-based extreme pressure agents include mineral oils having unsaturated bonds such as sulfurized whale oil and sulfurized dipentene, sulfurized oils and fats produced by adding sulfur to fats and oils, fatty acids, etc., dihenzyl disulfide, and dihenzyl disulfide. Disulfides such as diphenyl sulfide, di-t-butyl disulfide, di-5ec-butyl disulfide, di-n-butyl disulfide, di-t-octyl disulfide, diethyl disulfide, hensyl sulfide, diphenyl sulfide, g Monosulfides such as divinyl sulfide, dimethyl sulfide, diethyl sulfide, di-1-butyl sulfide, di-5ec-butyl sulfide, di-n-butyl disulfide, dimethyl trisulfide,
Examples include polysulfides such as di-t-butyl trisulfide, di-1-nonyl polysulfide, and olefin polysulfide, thiocarbonates represented by the general formula (wherein R represents a hydrocarbon group), and elemental sulfur. It will be done.

The halogen-based extreme pressure agent is allyl bromide.

Bromine compounds such as octadecyl bromide, cyclohexyl bromide, stearyl bromide, hensyl bromide, iodine compounds such as hensyl iodide, allyl iodide, butyl iodide, octadecyl iodide, cyclohexyl iodide, hexachloroethane, monochloroethane.

Examples include chlorine compounds such as chlorinated paraffin, chlorinated diphenyl, chlorinated fats and oils, methyl trichlorostearate, pentachloropentadienoic acid, esters of hexachloronaphthenic acid compounds, and imide derivatives of hexachloronaphthenic acid compounds.

Examples of the organometallic extreme pressure agents include zinc diisobutyldithiophosphate, zinc isobutylpentyldithiophosphate, zinc isopropyl-1-methylbutyldithiophosphate, zinc isobutylnonylphenyldithiophosphate 2, isobutylhebutylphenyldithiophosphate, and diheptyl zinc. Thiophosphates such as zinc phenyl dithiophosphate, zinc dinonyl phenyl dithiophosphate, and molybdenum dithiophosphate, zinc dimethyl dithiocarbamate, zinc diethyldithiocarbamate, zinc dibutyl dithiocarbamate, and zinc ethyl phenyl dithiocarbamate.

Thiocarbamates such as zinc dihendyldithiocarbamate, zinc dimethyldithiocarbamate, copper dimethyldithiocarbamate, iron dimethyldithiocarbamate, selenium diethyldithiocarbamate, silver diethyldithiocarbamate, metal alkyldithiocarbamates such as molybdenum and antimony, etc. Can be mentioned.

Examples of the composite extreme pressure agent include dialkylthiophosphate amines such as di-2-ethylhexylthiophosphate amine, propyl chloride, propyl bromide,
In addition to phosphoric acid esters of alkyl halides represented by propyl iodide phosphate, butyl chloride phosphate, butyl bromide phosphate, butyl iodide phosphate, etc., chloronaphsasanthate, etc., the general formula % formula % () (However, Each general R represents a hydrogen atom, an arnel group, an alkenyl group, or an aryl group. Thiophosphites represented by the following formula are highly effective.

The above-mentioned extreme pressure agents may be used alone, but it is also possible to use a mixture of two or more types.

Alternatively, in addition to the above-mentioned lubricant and extreme pressure agent, a rust preventive agent may be used in combination as necessary. As the rust preventive agent, any conventionally known rust preventive agent can be used.

The lubricant containing these dicarboxylic acid ester derivatives can be applied by applying or spraying a solution obtained by dissolving the above lubricant, or conversely, by soaking the lubricant in this solution and allowing it to dry. good.

[Effect]

Dicarboxylic acid ester derivatives exhibit good lubricating action and reduce the coefficient of friction. Moreover, this lubricating effect is not impaired even at low temperatures.

Therefore, lubricants containing this dicarboxylic acid ester Hy, rr form also exhibit good lubricity and low-temperature properties.

〔Example〕

Hereinafter, specific examples of the present invention will be described, but the present invention is not limited to these examples.

First, a dicarboxylic acid ester derivative was synthesized according to the following synthesis example.

Synthesis Example 1 Fumaric acid dipentadecafluorooctyl ester 25.4 g of pentadecafluorooctanol was dissolved in anhydrous Daiflon Solgent (manufactured by Daikin Industries, Ltd.),
After adding 3.3 g of triethylamine, 4.9 g of fumaric acid chloride was added dropwise over 30 minutes. After completion of the dropwise addition, the mixture was stirred at room temperature overnight, washed with water, 3% diluted hydrochloric acid, and 3% NaOH aqueous solution, and further washed with water until the washing solution became neutral. After drying the organic phase with anhydrous magnesium sulfate, the solvent was removed. Then, recrystallization was performed using Freon to obtain 25.1 g of fumaric acid dipentadecafluorooctyl ester. The melting point (m, p,) of the obtained fumaric acid dipentadecafluorooctyl ester was 83 to 83.5°C, and the yield was 89%.

Synthesis Example 2 After dissolving 15 g of fumaric acid fluorodecanol and 3.2 g of triethylamine in anhydrous Freon, fumaric acid chloride 2.
4 g was added dropwise over 30 minutes.After the completion of the 0 dropwise addition, the mixture was stirred at room temperature overnight, washed with water, 3% diluted hydrochloric acid, and 3% NaOH aqueous solution, and further washed with water until the washing solution became neutral. After drying the organic phase with anhydrous magnesium sulfate, the solvent was removed.

Then, recrystallization was performed using Freon to obtain 14.6 g of fumaric acid dinonadecafluorodecyl ester. The melting point (m, p
) is 114.2-115.5°C1 yield is 909/6
Met.

Synthesis Example 3 Glutaric acid dipentadecafluorooctyl ester After 15 g of pentadecafluorooctanol and 40 g of triethylamine were dissolved in anhydrous Freon, 3.3 g of glutaric acid chloride was added dropwise over 15 minutes. After completion of the dropwise addition, the mixture was stirred at room temperature overnight, refluxed for 2 hours, washed with water, 3% diluted hydrochloric acid, and 3% NaOH aqueous solution, and further washed with water until the washing solution became neutral. After drying the organic phase with anhydrous magnesium sulfate, the solvent was removed. Then, recrystallization was performed from a freon-petroleum ether mixed solvent to obtain 15.9 g of glutaric acid dipentadecafluorooctyl ester. The melting point (m, p, ) of the obtained glutaric acid dipentadecafluorooctyl ester was 30 to 31°C, and the yield was 94.6%.

Synthesis Example 4 Dipentadecafluorooctyl terephthalate 12 g of pentadecafluorooctanol and 3.2 g of triethylamine were dissolved in anhydrous Freon, and terephthalic acid chloride was added dropwise little by little over 20 minutes. After completion of the dropwise addition, the mixture was stirred at room temperature overnight, refluxed for 1 hour, washed with water, 3% diluted hydrochloric acid, and 3% NaOH aqueous solution, and further washed with water until the washing solution became neutral. After drying the organic phase with anhydrous magnesium sulfate, the solvent was removed. And freon-
Recrystallization was performed from a petroleum ether mixed solvent to obtain 12.2 g of terephthalic acid dipentadecafluorooctyl ester. The melting point (m, p,) of the obtained terephthalic acid dipentadecafluorooctyl ester is 83-83.5°C1
The yield was 87%.

Synthesis Examples 5 to 9 Compounds 5 to 9 were synthesized in the same manner as in Synthesis Example 1.

That is, the corresponding fluoroalcohol and triethylamine were dissolved in anhydrous Freon, and the corresponding acid chloride was added dropwise over several minutes. After completion of the dropwise addition, the mixture was stirred at room temperature overnight, washed with water, 3% diluted hydrochloric acid, and 3% NaOH, and further washed with water until the washing solution became neutral. After drying the organic phase with anhydrous magnesium sulfate, the solvent was removed.

Then, recrystallization was performed from Freon or Freon petroleum ether mixed solvent to obtain Compounds 5 to Synthesis Examples 9.

Table 1 shows the structural formulas of the compounds obtained in each of the above synthesis examples.

(Left below) Application Example 1 CO was deposited on a 14 μm thick polyethylene terephthalate film by the diagonal technique to form a ferromagnetic metal thin film with a thickness of 1000 μm.

Next, the dicarboxylic acid ester derivative shown in Table 1 (Compound 1 in Table 1) was applied to the surface of this ferromagnetic metal thin film at 0.0
5% by weight) At one time, a dilute solution of Freon was applied in an amount of 5%.
A sample tape was prepared by polishing the tape so that it had a width of 1/2 and cutting it to a width of 3 mm.

Application Example 2 to Application Example 9 Sample tapes were prepared in the same manner as in Application Example 1 except that Compounds 2 to 9 shown in Table 1 above were used as dicarboxylic acid ester derivatives.

For each sample tape produced, the temperature was 25°C1
The dynamic friction coefficient and shuttle durability were measured under conditions of relative humidity (RH) 50% and -5°C. This dynamic friction coefficient was tested by using a guide pin made of stainless steel (SUS304) and feeding it at a speed of 5 mm/se (with constant tension applied).The shuttle durability was also tested by using a guide pin made of stainless steel (SUS304) and feeding it at a speed of 5 mm/se. The shuttle running was carried out, and evaluation was made by the number of shuttles until the output decreased by 15 dB.Still durability was evaluated by evaluating the time at which the output decreased by 15 dB in a pause state.As Comparative Example 3, no lubricant was used at all. Measurements were also made on a blank tape that was not adhered.

The results are shown in Table 2.

(Below the margin) Table 2 (Below the margin) As is clear from Table 2 above, each application example shows the dynamic Ft-ta under each condition! The coefficient was small, the running was extremely stable, and no damage was observed on the tape surface even after running back and forth 100 times. Furthermore, the durability was extremely good, and no drop in output of 15 dB was observed even after 150 shuttle runs. On the other hand, with the comparative tape without a lubricant layer, the friction coefficient increased as the number of reciprocating runs increased, running was unstable, tape friction was observed, and durability was poor. Ta.

〔Effect of the invention〕

As is clear from the above description, the dicarboxylic acid ester derivative of the present invention exhibits extremely excellent lubricity, and the dicarboxylic acid ester derivative of the present invention is easy to synthesize and handle.

Therefore, if this dicarboxylic acid ester derivative is used alone or in combination with other components as a lubricant, it is suitable as a lubricant not only for various types of equipment but also for special purposes such as ferromagnetic metals, membranes, magnetic recording media, etc. Ah, the 7I71 of the present invention? The # agent is
Just by adhering to the surface, it exhibits a good lubricating effect over a long period of time, and its lubricating effect does not deteriorate even when used in low temperature ranges.

Claims (2)

[Claims] (1) General formula C_nF_2_n_+_1(CH_2)_jOOCRC
OO(CH_2)_jC_nF_2_n_+_1 (However, R in the formula is a divalent hydrocarbon group, n≧3, j≧0
It is. ) A dicarboxylic acid ester derivative represented by (2) General formula C_nF_2_n_+_1(CH_2)_jOOCRC
OO(CH_2)_jC_nF_2_n_+_1 (However, R in the formula is a divalent hydrocarbon group, n≧3, j≧0
It is. ) A lubricant containing a dicarboxylic acid ester derivative represented by: