JP2016013988A - Ester compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel asymmetric polyol ester compound that can easily be synthesized under a mild reaction condition from a variety of carboxylic acids and carboxylic acid esters and that has a low melting point and is excellent in viscosity index, heat resistance and color number.SOLUTION: Provided are an ester compound represented by the following formula (1), and a lubricating-oil and cosmetic raw-material containing the same. In the formula, Rand Rare, each independently, an alkyl group, aralkyl group or aryl group having 1 to 20 carbon atoms. R, R, Rand Rare, each independently, an alkyl group having 1 to 10 carbon atoms, and the combination of Rand Rand the combination of Rand Rare different.

Description

  The present invention relates to a hindered polyol ester compound which can be easily synthesized from various carboxylic acids and carboxylic acid esters under mild reaction conditions, and has a low melting point and excellent viscosity index, heat resistance and color number.

Polyol ester and ester-based synthetic oils must have high functionality because they have a better balance of various physical properties such as viscosity characteristics, thermal stability, oxidation stability, lubricity, volatility, and low temperature characteristics than mineral oil. Is a synthetic oil widely used in the field of lubrication (Non-Patent Document 1).
Among them, the hindered polyol ester does not have hydrogen at the β-position of the ester carbonyl group, so it does not undergo low-temperature low-temperature decomposition reaction via a pseudo-cyclic intermediate, and heat stability is a disadvantage of conventional synthetic synthetic oils. Excellent in heat resistance and oxidation stability, it has been widely used for lubricants and cosmetics for heat resistance.

  However, in various fields such as jet engine oil, automobile engine oil, air compressor oil, and flame retardant hydraulic oil, thermal stability and oxidation are further improved due to recent demands for higher performance, more severe use environment and longer life. Even in fields where lubricating oils with excellent stability are desired and low temperature characteristics are required, refrigerating machine oils with new characteristics are required due to environmental demands such as ozone depletion. Development of excellent polyol esters is desired and has been studied.

  For example, in the field of heat resistance applications, esters of hindered carboxylic acids and hindered polyols have been studied for further improvement of heat resistance. Patent Document 1 illustrates a combination of a tertiary carboxylic acid and a polyhydric alcohol as an example of improved heat resistance and viscosity index. In particular, in order to increase oxidation stability, a combination of a hindered carboxylic acid and a hindered alcohol is desirable, but it is known that an esterification reaction of a combination of a hindered carboxylic acid and a hindered alcohol is difficult. (Patent Document 2). Therefore, a method of reacting an acid chloride with alcohol is generally used. Moreover, when acid chloride was not used, the reaction temperature had to be very high in the presence of a catalyst.

  On the other hand, in a refrigeration cycle such as a car air conditioner, a building air conditioner, a freezer warehouse, and a refrigerator, a refrigerator oil composition in which a refrigerant is dissolved in refrigerator oil is used as a working fluid. Particularly in these areas, CFC (chlorofluorocarbon) and HCFC (hydrochlorofluorocarbon) are subject to regulation due to the problem of ozone layer destruction, and hydrofluorocarbon refrigerants are being used instead of these, and these refrigerants are dissolved. Polyol ester is used for refrigerating machine oil (Patent Document 3). The specification of Patent Document 4 describes that a polyol ester oil consisting of one kind of alcohol and one kind of fatty acid is usually easily crystallized or solidified from room temperature to low temperature for use in a polyol ester for low temperature applications. In general, the use of polyol esters for low-temperature applications is known to be used by mixing various fatty acids in order to avoid crystallization.

  The problem of crystallization of polyol esters is well known not only in the fields of lubricating oils, greases and refrigerator base oils but also in the field of cosmetic raw materials. Patent Document 5 describes a polyol ester compound that is difficult to crystallize at room temperature, and it is described that the amount of benzoic acid is limited due to crystallization.

  Although hindered polyol esters that have excellent heat resistance and viscosity characteristics and are difficult to crystallize are desired in various fields, the hindered polyols actually used are neopentyl glycol and trimethylolpropane. However, it is almost limited to pentaerythritol, ditrimethylolpropane, and dipentaerythritol, and a polyol skeleton that provides a novel hindered polyol ester applicable to these requirements has been widely desired.

Japanese Patent No. 3894983 Special table 2009-501142 Japanese Patent No. 2613526 JP 2013-133443 A Japanese Patent No. 4801589

Jiro Hirano, Petrochemical, 1980, vol.29, no.9, p.627-635

  In addition to these backgrounds, particularly in the field of heat-resistant polyol ester-based synthetic oils, a hindered carboxylic acid ester such as a tertiary carboxylic acid has been demanded to increase the heat resistance (Patent Document 1). The reaction rate becomes slower as the carboxylic acid becomes hindered, and a problem is that a high temperature is required during the synthesis, and a polyol ester can be easily obtained from the hindered carboxylic acid under mild conditions. There was a need for a hindered polyol skeleton. Based on these points, in the present invention, a hindered polyol that can be easily synthesized from various carboxylic acids and carboxylic acid esters under mild reaction conditions, is hardly crystalline and has excellent viscosity index, heat resistance, and color number. An ester compound is provided.

  As a result of intensive investigations to achieve the above object, the present inventors have excellent reactivity by using an asymmetric polyol having a specific substituent, and are excellent in viscosity index, oxidation stability, and number of colors. In addition, the present inventors have found that a hardly crystalline ester can be obtained and have reached the present invention. That is, the present invention is as follows.

[1]
Ester compound represented by general formula (1)
In the formula, each of R ¹ and R ⁶ independently represents an alkyl group having 1 to 20 carbon atoms, an aralkyl group, or an aryl group. R ² , R ³ , R ⁴ and R ⁵ each independently represents an alkyl group having 1 to 10 carbon atoms. And the combination of R ² and R ^{3 and} the combination of R ⁴ and R ⁵ are different.
[2]
The ester compound according to [1], wherein in formula (1), R ¹ and R ⁶ are alkyl groups having 1 to 20 carbon atoms, and R ² , R ³ , R ⁴ , and R ⁵ are alkyl groups having 1 to 6 carbon atoms.
[3]
The ester compound according to [1] or [2], wherein R ² and R ³ in formula (1) are methyl groups.
[4]
The ester compound [5] according to any one of [1] to [3], wherein in formula (1), R ¹ and R ⁶ are equal and are an alkyl group having 1 to 12 carbon atoms.
[6] Lubricating oil containing the ester according to any one of [1] to [4]
[7] A cosmetic raw material containing the ester according to any one of [1] to [4]
[6] Cosmetics using the cosmetic raw material according to [8]
Method for producing ester compound for obtaining ester compound represented by general formula (1) by dehydration condensation reaction of polyol represented by general formula (2) and carboxylic acid represented by general formula (3) and (4)
Here, in the general formula (2), R ² , R ³ , R ⁴ and R ⁵ each independently represent an alkyl group having 1 to 10 carbon atoms, and the combination of R ² and R ³ with R ⁴ and The combination of R ⁵ is different,
R ¹ COOH (3)
R ⁶ COOH (4)
In general formulas (3) and (4), R ¹ and R ⁶ each independently represents an alkyl group having 1 to 20 carbon atoms, an aralkyl group or an aryl group.
In the general formula (1), R ^{1 to} R ⁶ are as described above.
[9]
Catalysts in the dehydration condensation reaction are methanesulfonic acid, trifluoromethanesulfonic acid, p-toluenesulfonic acid, benzenesulfonic acid, dodecylbenzenesulfonic acid, sulfuric acid, solid acid catalyst containing sulfonic acid group, hydrochloric acid, phosphoric acid, titanium The method for producing an ester compound according to claim 8, which is at least one selected from tetramethoxide, titanium tetraethoxide, titanium tetraisopropoxide, titanium tetrabutoxide, dioctyltin oxide and dibutyltin oxide [10].
Method for producing ester compound for obtaining ester compound represented by general formula (1) by transesterification reaction between polyol represented by general formula (2) and carboxylic acid ester of general formula (5) and (6)
Here, in the general formula (2), R ² , R ³ , R ⁴ and R ⁵ each independently represent an alkyl group having 1 to 10 carbon atoms, and the combination of R ² and R ³ with R ⁴ and The combination of R ⁵ is different,
R ¹ COOR ⁷ (5)
R ⁶ COOR ⁸ (6)
In general formulas (5) and (6), R ¹ and R ⁶ each independently represents an alkyl group having 1 to 20 carbon atoms, an aralkyl group, or an aryl group. R ⁷ and R ⁸ each independently represents an alkyl group having 1 to 4 carbon atoms.
In the general formula (1), R ^{1 to} R ⁶ are as described above.
[11]
The catalyst in the transesterification reaction is at least selected from sulfuric acid, p-toluenesulfonic acid, titanate ester, zinc acetylacetone, dibutyltin oxide, sodium hydrogen carbonate, sodium carbonate, potassium carbonate, sodium hydroxide, potassium hydroxide and sodium methoxide The method for producing an ester compound according to [10], which is one.

  Various asymmetric polyol esters represented by the general formula (1) of the present invention can be synthesized easily. The obtained polyol ester has a small number of colors, is excellent in viscosity index and oxidation resistance, is hardly crystallizable, and can be applied to various fields such as lubricating oils and cosmetics. The industrial significance of the present invention is It is considered large.

¹ H-NMR chart of 4-oxa-2-butyl-2-ethyl-6,6-dimethylheptane-1,7-diyl dipivalate obtained in Example 1 ¹ H-NMR chart of 4-oxa-2-propyl-2,6,6-trimethylheptane-1,7-diyl dipivalate obtained in Example 2 ¹ H-NMR chart of bis (2-ethylhexanoic acid) 4-oxa-2-butyl-2-ethyl-6,6-dimethylheptane-1,7-diyl obtained in Example 3 ¹ H-NMR chart of bis (2-ethylhexanoic acid) 4-oxa-2-propyl-2,6,6-trimethylheptane-1,7-diyl obtained in Example 4 ¹ H-NMR chart of bis (3,5,5-trimethylhexanoic acid) 4-oxa-2-butyl-2-ethyl-6,6-dimethylheptane-1,7-diyl obtained in Example 5 ¹ H-NMR chart of bis (3,5,5-trimethylhexanoic acid) 4-oxa-2-propyl-2,6,6-trimethylheptane-1,7-diyl obtained in Example 6 ¹ H-NMR chart of 2,2-dimethylpropane-1,3-diyl dipivalate obtained in Comparative Example 1 ¹ H-NMR chart of bis (2-ethylhexanoic acid) 2,2-dimethylpropane-1,3-diyl obtained in Comparative Example 2 ¹ H-NMR chart of bis (3,5,5-trimethylhexanoic acid) 2,2-dimethylpropane-1,3-diyl obtained in Comparative Example 3

  Hereinafter, preferred embodiments of the present invention will be described in detail.

The ester compound of the present invention is represented by the general formula (1).
In the formula, each of R ¹ and R ⁶ independently represents an alkyl group having 1 to 20 carbon atoms, an aralkyl group, or an aryl group. R ² , R ³ , R ⁴ and R ⁵ each independently represents an alkyl group having 1 to 10 carbon atoms. And the combination of R ² and R ^{3 and} the combination of R ⁴ and R ⁵ are different.

The ester represented by the general formula (1) is preferably a linear alkyl group having 1 to 6 carbon atoms, and R ² , R ³ , R ⁴ and R ⁵ are each independently a linear alkyl group in terms of obtaining raw materials. ^More preferably, ² and R ³ are both methyl groups, one of R ⁴ and R ⁵ is a linear alkyl group having 2 to 6 carbon atoms, and the remainder is a linear alkyl group having 1 to 6 carbon atoms.
R ¹ and R ⁶ are equal and are preferably an alkyl group having 1 to 12 carbon atoms.

  The compound represented by the general formula (1) is a dehydration condensation reaction of a hindered polyol and a carboxylic acid represented by the general formula (2) or a transesterification between the hindered polyol and the carboxylic acid ester represented by the general formula (2). Synthesized by reaction.

Here, in the general formula (2), R ² , R ³ , R ⁴ and R ⁵ each independently represent an alkyl group having 1 to 10 carbon atoms, and the combination of R ² and R ³ with R ⁴ and the combination of R ⁵ is different.

The diol described in the general formula (2) can be obtained by hydrogenating and reducing the acetal of the general formula (3).
Here, in the general formula (3), R ² , R ³ , R ⁴ and R ⁵ each independently represent an alkyl group having 1 to 10 carbon atoms, and the combination of R ² and R ³ with R ⁴ and the combination of R ⁵ is different.

The acetal described in the general formula (3) is an acetal of 2,2-disubstituted-3-hydroxypropanal and 2,2-disubstituted-1,3-propanediol as described in the formula (4). Can be obtained.
Here, in the general formula (4), R ² , R ³ , R ⁴ , and R ⁵ each independently represents an alkyl group having 1 to 10 carbon atoms, and the combination of R ² and R ³ with R ⁴ and the combination of R ⁵ is different.

  Moreover, when synthesizing the compound represented by the general formula (1) by the dehydration condensation reaction or the transesterification reaction, one kind of the polyol represented by the general formula (2) may be used, or two or more kinds may be mixed. May be used.

The carboxylic acid that can be used in the dehydration condensation reaction may be any of saturated and unsaturated primary carboxylic acids, secondary carboxylic acids, and tertiary carboxylic acids.
In addition, the carboxylic acid may be linear or branched, and two or more kinds may be mixed and used.
Examples of saturated linear primary carboxylic acids include caproic acid, enanthic acid, caprylic acid, verargonic acid, capric acid, undecylic acid, lauric acid, tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, margaric acid, stearic acid , Nonadecylic acid, arachidic acid, henicosyl, behenic acid, tricosylic acid and lignoceric acid. More preferred are caproic acid, enanthic acid, caprylic acid, verargonic acid, capric acid, undecyl acid and lauric acid.

  The branched primary carboxylic acid and secondary carboxylic acid include structural isomers of these saturated linear primary carboxylic acids. Examples of branched primary carboxylic acids include 3,5,5-trimethylhexanoic acid, 3-methylvaleric acid, 4-methylvaleric acid, 5-methylhexanoic acid, 4-methyloctanoic acid, 4-ethyloctanoic acid. 4-methylnonanoic acid and the like. More preferred is 3,5,5-trimethylhexanoic acid.

  Examples of secondary carboxylic acids include 2-methylpentanoic acid, 2-ethylpentanoic acid, 2-propylpentanoic acid, 2-methylhexanoic acid, 2-ethylhexanoic acid, 2-methylheptanoic acid, 2-ethylheptanoic acid 2-propylheptanoic acid, 2-methyloctanoic acid, 2-ethyloctanoic acid, 2,4-dimethyloctanoic acid, 2-hexyldecanoic acid, 2-heptylundecanoic acid, 2-methylhexadecanoic acid, 2-decyldodecanoic acid, 2 -Hexadecyl octadecanoic acid, isomyristic acid and isostearic acid. More preferably, 2-ethylpentanoic acid, 2-methylhexanoic acid, 2-ethylhexanoic acid, 2-methylheptanoic acid, 2-ethylheptanoic acid and 2-propylheptanoic acid are more preferable, and 2-ethylhexanoic acid is more preferable. 2-ethylheptanoic acid and 2-propylheptanoic acid.

  Examples of unsaturated primary carboxylic acids include α-linolenic acid, stearidonic acid, eicosapentaenoic acid, docosapentaenoic acid, linoleic acid, γ-linolenic acid, dihomoγ-linolenic acid, arachidonic acid, palmitoleic acid, vaccenic acid, Examples include pauric acid, oleic acid, elaidic acid, erucic acid, and nervonic acid.

  Examples of the tertiary carboxylic acid include structural isomers of the above-mentioned saturated linear primary carboxylic acid, such as pivalic acid, 2,2-diisopropylpropionic acid, 2,2-dimethylbutyric acid, 2-methyl- 2-ethylbutyric acid, 2-ethyl-2,3,3-trimethylbutyric acid, 2,2-dimethylpentanoic acid, 2-methyl-2-ethylpentanoic acid, 2,2,3,3-tetramethylpentanoic acid, 2 , 2,3,4-tetramethylpentanoic acid, 2,2,4,4-tetramethylpentanoic acid, 2,2-dimethylhexanoic acid, 2,2-dimethylheptanoic acid, 2,2-dimethyloctanoic acid, 2,2-dimethylnonanoic acid, 2,2-dimethyldecanoic acid, 2,2-dimethylundecanoic acid, 2,2-dimethyldodecanoic acid, 2,2-dimethyltridecanoic acid, 2-methyl-2-ethyldodecanoic acid 2,2-dimethylpentadecanoic acid, 2-methyl-2-ethyltetradecanoic acid, 2,2-diethyltridecanoic acid, 2-methyl-2-ethyloctadecanoic acid, 2,2-diethylheptadecanoic acid and 2,2- Examples include diethyl nonadecanoic acid.

  Moreover, you may add 0.9 equivalent or less dicarboxylic acid with respect to diol as carboxylic acid. Examples of the dicarboxylic acid include adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid and the like. One kind of these carboxylic acids may be used, or two or more kinds may be mixed and used.

  The dehydration condensation reaction between the polyol represented by the general formula (2) and the carboxylic acid is usually performed at 100 to 250 ° C. The reaction time varies depending on the reaction scale and temperature, but it is performed in 1-20 hours. The pressure is normal pressure or reduced pressure. In the case of reduced pressure, the pressure is usually 0.1-80 kPa.

  An azeotropic solvent may or may not be used, and when used, a solvent having an appropriate boiling point is selected. For example, benzene, toluene, xylene, cumene, heptane, octane, decane, cyclohexane, decalin, chloroform, 1,2-dichloroethane and chlorobenzene. Moreover, you may use a solvent in mixture of 2 or more types. The amount of solvent is 0.5-30 mass times with respect to the diol to be used, and 1-10 mass times is preferable.

Moreover, it is not necessary to use a catalyst, and when using a catalyst, 0.01-4 mass% is preferable. Usable as the catalyst are ordinary organic acids, inorganic acids, and Lewis acids, and these organic acids include alkane sulfonic acids and aryl sulfonic acids.
Examples of each catalyst include methanesulfonic acid and trifluoromethanesulfonic acid as alkanesulfonic acids, p-toluenesulfonic acid, benzenesulfonic acid and dodecylbenzenesulfonic acid as arylsulfonic acids, and inorganic acids as Sulfuric acid, hydrochloric acid and phosphoric acid, and examples of Lewis acids include titanium tetramethoxide, titanium tetraethoxide, titanium tetraisopropoxide, titanium tetrabutoxide, dioctyltin oxide and dibutyltin oxide. Moreover, a catalyst can also be used in mixture of 2 or more types selected from the above.
In particular, in the case of a sulfonic acid catalyst having a PKa of 2 or less such as p-toluenesulfonic acid, methanesulfonic acid, and sulfuric acid, the reaction acceleration is remarkable.

  The molar ratio of the polyol represented by the general formula (2) to the carboxylic acid is 1.0: 2.0 to 4.0, preferably 1.0: 2.0 to 3.0. In particular, when p-toluenesulfonic acid or the like is used as a catalyst, the reaction can be performed with a reduced amount of carboxylic acid.

  The carboxylic acid ester that can be used in the transesterification reaction may be any selected from saturated primary carboxylic acid ester, unsaturated primary carboxylic acid ester, secondary carboxylic acid ester, and tertiary carboxylic acid ester. Two or more carboxylic acid esters can also be used.

  Examples of saturated primary carboxylic acid esters include methyl caproate, methyl enanthate, methyl caprylate, methyl verargonate, methyl caprate, methyl undecylate, methyl laurate, tridecylic acid, myristic acid, pentadecylic acid, palmitic acid , Margaric acid, methyl stearate, methyl nonadecylate, methyl arachidate, methyl hehenosyl, methyl behenate, methyl tricosylate and methyl lignocerate. More preferred are methyl caproate, methyl enanthate, methyl caprylate, methyl verargonate, methyl caprate, methyl undecylate and methyl laurate. Examples of the saturated secondary and tertiary carboxylic acid esters include the structural isomers of the saturated primary carboxylic acid esters described above.

  Further, as unsaturated primary carboxylic acid ester, methyl α-linolenate, methyl stearidinate, methyl eicosapentanoate, methyl docosapentaenoate, methyl linoleate, methyl γ-linolenate, methyl dihomoγ-linolenate Methyl arachidonate, methyl palmitoleate, methyl bacsenate, methyl paurate, methyl oleate, methyl elaidate, methyl erucate and methyl nervonate.

The transesterification reaction between the polyol represented by the general formula (2) and the carboxylic acid ester is usually performed at 100 to 250 ° C. while removing the generated alcohol from the reaction system. The reaction time varies depending on the scale and temperature of the reaction, but the reaction time is 1-20 hours. The pressure is normal pressure or reduced pressure. In the case of reduced pressure, the pressure is usually 0.1-80 kPa. Catalysts used for transesterification include acidic catalysts such as sulfuric acid and p-toluenesulfonic acid, Lewis acid catalysts such as titanate ester, zinc acetate, acetylacetone zinc and dibutyltin oxide, sodium bicarbonate, sodium carbonate, potassium carbonate, water Any of basic catalysts such as sodium oxide, potassium hydroxide and sodium methoxide may be used. Two or more kinds of catalysts can be mixed and used.
The amount of the catalyst used is preferably 0.1-4% by mass.

  By using the alcohol of the general formula (2), the dehydration condensation reaction with various carboxylic acids and the transesterification reaction with various carboxylic acid esters proceed more quickly and mildly than when using neopentyl glycol. In addition, a hindered polyol ester having a high yield, a low melting point, and an excellent viscosity index and color number can be obtained.

  The polyol ester of the present invention is usually used from weight-resistant additives, oiliness agents, antioxidants, detergent dispersants, antifoaming agents, rust inhibitors, demulsifiers, pour point depressants, viscosity index improvers, and the like. It is possible to mix at least one selected various additives as required.

  In addition, other lubricant base oils such as mineral oil, polyalphaolefin, polybutene, alkylbenzene, animal and vegetable oils, organic acid esters, polyvinyl ethers, polyphenyl ethers, and alkyls may be used as long as the performance is not deteriorated. It is also possible to mix and use at least one selected from phenyl ether as necessary.

  Using the polyol ester of the present invention as a base oil, grease, refrigerating machine oil, insulating oil, hydraulic hydraulic oil, gear operating system lubricating oil, cutting / grinding oil, transmission lubricating oil, wind power booster oil, internal combustion engine It can be suitably used for applications such as lubricating oil for engine (engine oil), lubricating oil for power generation turbines, lubricating oil for compressors and lubricating oil for bearings.

  Further, the polyol ester of the present invention is used as a cosmetic raw material such as lipstick, eye shadow, hair cosmetic, emulsion, water-in-oil hand cream, creamy oil-in-water sunscreen cosmetic, beauty nail, lip balm and lip gloss. Can be used by appropriately blending them.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not particularly limited to the following examples.

Analysis of the reaction was performed by gas chromatography. For gas chromatography, 6850 manufactured by Agilent Technologies was used. The column used was HP-1 manufactured by J & W. The column temperature was maintained at 100 ° C. for 5 minutes, then heated to 275 ° C. at 10 ° C./minute, and then maintained for 20 minutes. The injection temperature was 270 ° C., the detector was TCD, and the temperature was 290 ° C. Helium was used as the carrier gas.
The product was identified by ¹ H-NMR spectrum. The measured using JEOL Ltd. JNM-ECA500, solvent and CDCl _3, using tetramethylsilane as the internal standard.

Synthesis example 1
Synthesis of 2- (5-butyl-5-ethyl-1,3-dioxan-2-yl) -2-methylpropan-1-ol
2,2-dimethyl-3-hydroxypropanal 73.6 g, 2-butyl-2-ethyl-1,3-propanediol 111.8 g, benzene 705 g and granular Nafion (trade name “NR-50”, Sigma-Aldrich) 3.0g) was placed in a 2L round bottom flask, and the water produced under normal pressure was azeotroped with benzene while being extracted out of the system using a Dean-Stark apparatus until the water stopped distilling. It was. After filtration and concentration, 2- (5-butyl-5-ethyl-1,3-dioxan-2-yl) -2-methylpropan-1-ol was obtained in 99% yield by distillation under reduced pressure. .

Synthesis example 2
2- (5-methyl-5-propyl-1,3-dioxan-2-yl) -2-methylpropan-1-ol is obtained by synthesizing 2-butyl-2-ethyl-1,3-propanediol of Synthesis Example 1. It was synthesized by replacing with 2-methyl-2-propyl-1,3-propanediol.

  The catalyst used for hydrogenation of acetal was synthesized as follows.

Carrier preparation Zirconium oxide used as a carrier for the metal component was prepared by the following method.
A white precipitate was obtained by dropping 15.5 g of 28% aqueous ammonia with stirring into 505 g of an aqueous zirconium oxynitrate solution having a concentration of 25% by mass in terms of zirconium oxide (ZrO ₂ ). This was filtered, washed with ion-exchanged water, and then dried at 110 ° C. for 10 hours to obtain hydrous zirconium oxide. This is stored in a magnetic crucible, and subjected to a baking treatment at 400 ° C. for 3 hours in the air using an electric furnace, and then pulverized in an agate mortar and expressed as powdered zirconium oxide (hereinafter referred to as “carrier A”). .) Was obtained. The BET specific surface area (measured by a nitrogen adsorption method) of the carrier A was 102.7 m ² / g.

Catalyst preparation A catalyst containing palladium as a specific metal component was prepared by the following method.
0.66 mass% palladium chloride-0.44 mass% sodium chloride aqueous solution was added to 50 g of carrier A, and the metal component was adsorbed on the carrier. A formaldehyde-sodium hydroxide aqueous solution was added thereto to instantaneously reduce the adsorbed metal component. Thereafter, the catalyst was washed with ion-exchanged water and dried to prepare a 1.0% by mass palladium-supported zirconium oxide catalyst (hereinafter referred to as “catalyst A”).

Synthesis example 3
Synthesis of 4-oxa-2-butyl-2-ethyl-6,6-dimethylheptane-1,7-diol
In a 500 mL SUS reactor, 3.0 g of catalyst A, 60.0 g of 2- (5-butyl-5-ethyl-1,3-dioxan-2-yl) -2-methylpropan-1-ol, and 1 , 4-dioxane 240 g was added, and the inside of the reactor was replaced with nitrogen gas. Thereafter, 8.5 MPa of hydrogen gas was charged into the reactor, and the reaction temperature was raised to 230 ° C., and the reaction was performed for 5 hours while maintaining the hydrogen pressure at 13 MPa. Then, after cooling and filtering the contents of the reactor to separate the catalyst, purification by distillation under reduced pressure yielded the desired product.

Synthesis example 4
4-oxa-2-methyl-2-propyl-6,6-dimethylheptane-1,7-diol is 2- (5-butyl-5-ethyl-1,3-dioxan-2-yl) of Synthesis Example 3 Synthesis was performed by replacing 2-methylpropan-1-ol with 2- (5-methyl-5-propyl-1,3-dioxan-2-yl) -2-methylpropan-1-ol.

Example 1
Synthesis of dipivalic acid 4-oxa-2-butyl-2-ethyl-6,6-dimethylheptane-1,7-diyl
M-xylene of 4-oxa-2-butyl-2-ethyl-6,6-dimethylheptane-1,7-diol (24.66 g, 100 mmol) and pivalic acid (23.51 g, 230 mmol, 2.3 eq) ( P-Toluenesulfonic acid monohydrate (578.7 mg, 3.04 mmol, 3 mol%) was added to the solution at room temperature. Thereafter, the inner temperature was heated to 155 to 160 ° C. under nitrogen, and water was removed from the system by azeotropy with m-xylene. After heating for 14 hours and cooling, the diester was 99.5 Area% by GC analysis.
After washing with 5% potassium hydroxide, it was washed with water until the washing solution became neutral. The acid was distilled off under reduced pressure and then treated with activated carbon to obtain 38.6 g of the desired product in a yield of 93%. The target APHA was 28. In addition, the time course of the reaction was followed by GC.

¹ H-NMR
δ (ppm): 0.80 (t, 3H, J = 7.6 Hz, C H ₃ CH ₂ ), 0.86 (t, 3H, J = 7.2 Hz, C H ₃ CH ₂ ), 0.91 (S, 6H, 2XC H ₃ ), 1.196 (s, 9H, C (C H ₃ ) ₃ ), 1.204 (s, 9H, C (C H ₃ ) ₃ ), 1.14-1. _{38 (m, 8H, C H} 2 C H 2 C H 2 CH 3 + CH 2 CH 3), 3.12 (s, 2H, OC H 2), 3.17 (s, 2H, OC H 2), 3.84 (s, 2H, C H ₂ OCO). 3.89 (s, 2H, C H ₂ OCO)

Example 2
Synthesis of dipivalic acid 4-oxa-2-propyl-2,6,6-trimethylheptane-1,7-diyl
4-Oxa-2-propyl-2,6,6-trimethylheptane-1,7-diol (32.76 g, 150 mmol) and pivalic acid (36.0 g, 352 mmol, 2.3 eq) in m-xylene (20. 68 g) p-Toluenesulfonic acid monohydrate (859.1 mg, 4.52 mmol, 3 mol%) was added to the solution at room temperature. The reaction was carried out under the same conditions as in Example 1, and water was removed from the system by azeotropy with m-xylene. When heated for 15 hours and then cooled, the diester was 99.9 Area% by GC analysis.
After washing with 5% potassium hydroxide, it was washed with water until the washing solution became neutral. After the acid was distilled off under reduced pressure, the product was treated with activated carbon to obtain the desired product in 57.3 g, yield 99%. Moreover, APHA of the obtained target object was 27.

¹ H-NMR
δ (ppm): 0.86-0.90 (m, 6H, C H ₃ CH ₂ + C H ₃ ), 0.92 (s, 6H, 2XC H ₃ ), 1.20 (s, 9H, C ( C H ₃ ) ₃ ), 1.21 (s, 9H, C (C H ₃ ) ₃ ), 1.23-1.28 (m, 4H, C H ₂ C H ₂ CH ₃ ), 3.13 ( _{s, 2H, OC H 2)} , 3.15 (d, 1H, J = 8.9Hz, of _{OC H 2 1H), 3.18 (} d, 1H, J = 8.9Hz, of OC _{H 2} 1H) , 3.85 (s, 2H, C H ₂ OCO), 3.87 (s, 1H, 1H of C H ₂ OCO), 3.88 (s, 1H, 1H of C H ₂ OCO)

Example 3
Synthesis of bis (2-ethylhexanoic acid) 4-oxa-2-butyl-2-ethyl-6,6-dimethylheptane-1,7-diyl
M of 4-oxa-2-butyl-2-ethyl-6,6-dimethylheptane-1,7-diol (24.64 g, 100 mmol) and 2-ethylhexanoic acid (30.29 g, 210 mmol, 2.1 eq) -To a solution of xylene (20.07 g), p-toluenesulfonic acid monohydrate (565.9 mg, 2.97 mmol, 3 mol%) was added at room temperature. Thereafter, heating was performed so that the internal temperature was 160 to 165 ° C. under nitrogen, and water was removed from the system by azeotropy with m-xylene. After 10 hours, the diester was 99.5 Area% or more by GC analysis, and after heating for 13 hours, the diester was 99.9 Area% or more by GC analysis.
After washing with 5% potassium hydroxide, it was washed with water until the washing solution became neutral. The acid was distilled off under reduced pressure and then treated with activated carbon to obtain 48.79 g of the desired product in a yield of 98%.
In addition, the time course of the reaction was followed by GC.

¹ H-NMR
δ (ppm): 0.80 (t, 3H, J = 7.4 Hz, C H ₃ CH ₂ ), 0.85-0.93 (m, 21H, 2XC H ₃ CH ₂ + 2XC H ₃ CH ₂ + C H _{3 CH 2 + 2XC H 3)} , 1.11-1.39 (m, 16H, 2XC H 2 C H 2 CH 3 + C H 2 C H 2 C H 2 CH 3 + C H 2 CH 3), 1.42- 1.68 (m, 8H, 2XOCOCH ( C H 2 CH 3) C H 2), 2.23-2.31 (m, 2H, 2XOCOC H), 3.12 (s, 2H, OC H 2), 3.17 (s, 2H, OC H ₂ ), 3.87 (s, 2H, C H ₂ OCO), 3.91 (s, 2H, C H ₂ OCO)

Example 4
Synthesis of bis (2-ethylhexanoic acid) 4-oxa-2-propyl-2,6,6-trimethylheptane-1,7-diyl
M-Xylene of 4-oxa-2-propyl-2,6,6-trimethylheptane-1,7-diol (21.91 g, 100 mmol) and 2-ethylhexanoic acid (33.28 g, 231 mmol, 2.3 eq) To the (22.38 g) solution, p-toluenesulfonic acid monohydrate (570.4 mg, 3.00 mmol, 3 mol%) was added at room temperature. The reaction was carried out under the same conditions as in Example 3, and water was removed from the system by azeotropy with m-xylene. After heating for 14 hours and cooling, the diester was 99.9 Area% by GC analysis.
After washing with 5% potassium hydroxide, it was washed with water until the washing solution became neutral. After the acid was distilled off under reduced pressure, the target product was quantitatively obtained by treating with activated carbon. APHA was 22.

¹ H-NMR
δ (ppm): 0.85 to 0.96 (m, 24H, 2XC H ₃ CH ₂ + 2XC H ₃ CH ₂ + 2XC H ₃ + C H ₃ CH ₂ + C H ₃ ), 1.21-1.38 (m, _{12H, 2XC H 2 C H 2} CH 3 + C H 2 C H 2 CH 3), 1.41-1.68 (m, 8H, 2XOCOCH (C H 2 CH 3) C H 2), 2.24-2 .33 (m, 2H, 2XOCOC H ), 3.11-3.22 (m, 4H, 2XOC H ₂ ), 3.85-3.94 (m, 4H, 2XC H ₂ OCO)

Example 5
Synthesis of bis (3,5,5-trimethylhexanoic acid) 4-oxa-2-butyl-2-ethyl-6,6-dimethylheptane-1,7-diyl
4-oxa-2-butyl-2-ethyl-6,6-dimethyl-1,7-heptanediol (24.73 g, 100 mmol) and 3,5,5-trimethylhexanoic acid (33.30 g, 210 mmol, 2. 1 eq) in toluene (20.03 g) was added sulfuric acid (104.7 mg, 1.07 mmol, 1 mol%) at room temperature. Thereafter, the inside temperature was heated to 135 ° C. under nitrogen, and water was removed from the system by azeotropy with toluene. When the mixture was heated for 14 hours and then cooled, the diester was 99.9 Area% or more by GC analysis.
After washing with 5% potassium hydroxide, it was washed with water until the washing solution became neutral. The acid was distilled off under reduced pressure, and then treated with activated carbon to obtain 49.25 g of the desired product in a yield of 93%.

¹ H-NMR
δ (ppm): 0.80 (t, 3H, J = 7.6 Hz, C H ₃ CH ₂ ), 0.86-0.93 (m, 27H, 2XC H ₃ + C H ₃ CH ₂ + 2XC (C H _{3) 3), 0.96-1.00 (m} , 6H, 2XC H 3 CH), 1.09-1.38 (m, 12H, C H 2 C H 2 C H 2 CH 3 + C H 2 CH ₃ + 2XC H ₂ C (CH ₃ ) ₃ ), 2.00-2.08 (m, 2H, 2XC H CH ₃ ), 2.08-2.15 (1H of m, 2H, 2XC H ₂ COO), 2.32 (dd, 1H, J = 5.7, 14.3 Hz, 1H of 2XC H ₂ COO), 3.11 (s, 2H, OC H ₂ ), 3.16 (s, 2H, OC H ₂ ), 3.81-3.95 (m, 4H, 2XC H ₂ OCO)

Example 6
Synthesis of bis (3,5,5-trimethylhexanoic acid) 4-oxa-2-propyl-2,6,6-trimethylheptane-1,7-diyl
4-oxa-2-propyl-2,6,6-trimethyl-1,7-heptanediol (22.16 g, 101 mmol) and 3,5,5-trimethylhexanoic acid (34.03 g, 215 mmol, 2.1 eq) P-Toluenesulfonic acid monohydrate (568.9 mg, 2.99 mmol, 3 mol%) was added to a toluene (23.31 g) solution at room temperature. The reaction was carried out under the same conditions as in Example 5, and water was removed from the system by azeotropy with toluene. It was cooled after heating for 7 hours. The diester was 99.8 Area% by GC analysis. After washing with 5% potassium hydroxide, it was washed with water until the washing solution became neutral. The acid was distilled off under reduced pressure and then treated with activated carbon to obtain 50.0 g of the desired product in a yield of 99%.

¹ H-NMR
δ (ppm): 0.86-0.93 (m, 30H, 2XC H ₃ + C H ₃ CH ₂ + C H ₃ + 2XC (C H ₃ ) ₃ ), 0.98 (d, 6H, J = 6.6 Hz) , 2XC H ₃ CH), 1.12 (dd, 2H, J = 6.3, 14.0 Hz, 2XC H ₂ C (CH ₃ ) ₃ 1H), 1.22-1.28 (m, 6H, _{C H 2 C H 2 CH 3} + 2XC H 2 C 1H of _{(CH 3) 3), 2.00-2.08} (m, 2H, 2XC H CH 3), 2.09-2.15 (m, 2H , 2XC H ₂ COO 1H), 2.32 (dd, 1H, J = 5.7, 14.3 Hz, 2XC H ₂ COO 1H), 3.11-3.19 (m, 4H, 2XOC H ₂ ), 3.82-3.93 (m, 4H, 2XC H ₂ OCO)

Example 7
Tracking of formation rate of 4-oxa-2-butyl-2-ethyl-6,6-dimethylheptane-1,7-diyl dioctanoate
Mixing of 4-oxa-2-butyl-2-ethyl-6,6-dimethylheptane-1,7-diol (24.65 g, 100.0 mmol) and methyl octoate (39.58 g, 250 mmol, 2.5 eq) To the solution was added orthotitanate tetraisopropoxide (291.9 mg, 1.03 mmol, 1 mol%) at room temperature. Thereafter, the mixture was heated to 140 to 145 ° C. under nitrogen, and the reaction progress was monitored by GC.

Comparative Example 1
Synthesis of 2,2-dimethylpropane-1,3-diyl dipivalate
In place of 4-oxa-2-butyl-2-ethyl-6,6-dimethylheptane-1,7-diol of Example 1, 2,2-dimethylpropane-1,3-diol was used and The reaction was carried out under the same conditions, and water was removed from the system by azeotropy with m-xylene. After heating for 14 hours and cooling, the diester was 59.6 Area% by GC analysis. After washing with 5% potassium hydroxide, it was washed with water until the washing solution became neutral. The acid was distilled off under reduced pressure, and the product was obtained by separating and purifying from monoester by silica gel column chromatography.

¹ H-NMR
δ (ppm): 0.99 (s, 6H, 2XC H ₃ ), 1.21 (s, 18H, 2XC (C H ₃ ) ₃ ), 3.88 (s, 4H, 2XC H ₂ OCO)

Comparative Example 2
Synthesis of bis (2-ethylhexanoic acid) 2,2-dimethylpropane-1,3-diyl
In place of 4-oxa-2-butyl-2-ethyl-6,6-dimethylheptane-1,7-diol of Example 3, 2,2-dimethylpropane-1,3-diol was used and The reaction was carried out for 9 hours under the same conditions, and water was removed from the system by azeotropy with m-xylene. During this time, the time course of the reaction was followed by GC. After 9 hours, GC analysis revealed that the diester was 60.8 Area%. After that, the temperature was raised to 200 ° C., heated for 15 hours, cooled, washed with 5% potassium hydroxide, and washed with water until the washing solution became neutral. . The acid was distilled off under reduced pressure, followed by separation and purification by silica gel column chromatography to obtain the desired product.

¹ H-NMR
δ (ppm): 0.86-0.91 (m, 12H, 2XC H ₃ CH ₂ + 2XC H ₃ CH ₂ ), 0.99 (s, 6H, 2XC H ₃ ), 1.20-1.35 ( _{m, 8H, 2XC H 2 C} H 2 CH 3), 1.42-1.66 (m, 8H, 2XOCOCH (C H 2 CH 3) C H 2 CH 2), 2.25-2.32 (m , 2H, 2XC H COO), 3.894 (1H of s, 2H, 2XC H ₂ OCO), 3.896 (1H of s, 2H, 2XC H ₂ OCO)

Comparative Example 3
Synthesis of bis (3,5,5-trimethylhexanoic acid) 2,2-dimethylpropane-1,3-diyl
The same conditions as in Example 6, except that 2,2-dimethylpropane-1,3-diol was used instead of 4-oxa-2-propyl-2,6,6-trimethyl-1,7-heptanediol in Example 6. The water was removed from the system by azeotropy with toluene. The mixture was heated for 5 hours, cooled, washed with 5% potassium hydroxide, and then washed with water until the washing solution became neutral. After the acid was distilled off under reduced pressure, the target product was obtained by treating with activated carbon.

¹ H-NMR
δ (ppm): 0.91 (s, 18H, 2XC (C H ₃ ) ₃ ), 0.98 (s, 6H, 2XC H ₃ ), 0.98 (d, 6H, J = 6.6 Hz, 2XC _{H 3 CH), 1.13 (dd} , 2H, J = 6.3,14.0Hz, 2XC H 2 C (CH 3) 3 of 1H), 1.24 (dd, 2H , J = 4.0, 14.0 Hz, 2XC H ₂ C (CH ₃ ) ₃ 1H), 1.99-2.08 (m, 2H, 2XC H CH ₃ ), 2.14 (dd, 2H, J = 8.3, 14 .5Hz, 2XC H ₂ COO 1H), 2.33 (dd, 2H, J = 5.7, 14.5Hz, 2XC H ₂ COO 1H), 3.861 (d, 1H, J = 10.9Hz) _{, C H 2 OCO), 3.866} (d, 1H, J = 10.9Hz, C H 2 OCO), 3.899 (d, 1H, _{= 10.9Hz, C H 2 OCO)} , 3.905 (d, 1H, J = 10.9Hz, C H 2 OCO)

Comparative Example 4
Tracking of production rate of 2,2-dimethylpropane-1,3-diyl dioctanoate In place of 4-oxa-2-butyl-2-ethyl-6,6-dimethylheptane-1,7-diol in Example 7 The reaction was conducted under the same conditions as in Example 7 using 2,2-dimethylpropane-1,3-diol, and the progress of the reaction was followed by GC.

Example 8 and Comparative Example 5
The production rate of dipivalate ester in Example 1 and Comparative Example 1 was monitored by gas chromatography, and the GC area ratio of the diester after 10 hours was compared. The area ratio of diester is 100X (diester area) / (diester area + monoester area + diol area).
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Example 9 and Comparative Example 6
The production rate of bis (2-ethylhexanoic acid) ester in Example 3 and Comparative Example 2 was monitored by gas chromatography, and the GC area ratio of the diester after 7.5 hours was compared. The area ratio of diester is 100X (diester area) / (diester area + monoester area + diol area).
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  As shown in Table 1 and Table 2, in the dehydration condensation reaction using an acid catalyst of 2,2-dimethylpropane-1,3-diol (neopentyl glycol) and tertiary / secondary carboxylic acid, which are used for general purposes After 10 hours and 7.5 hours, the diester had a GC area ratio of 56% and 59%, but surprisingly, as shown in Examples 8 and 9, 4-oxa-2 With diols such as -butyl-2-ethyl-6,6-dimethylheptane-1,7-diol, the reaction proceeded in high yield under very mild conditions.

Example 10 and Comparative Example 7
The dioctanoic acid ester production rate in the transesterification reaction of Example 7 and Comparative Example 4 was monitored by gas chromatography, and the GC area ratio of the diester after 18 hours was compared. The area ratio of diester is 100X (diester area) / (diester area + monoester area + diol area).
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  As shown in Table 3, 2,2-dimethylpropane-1,3-diol and carboxylic acid are widely used in the transesterification reaction using orthotitanate tetraisopropoxide which is often used for ester synthesis as a catalyst. The reaction with an acid ester does not produce any ester as in Comparative Example 4, but surprisingly, as shown in Example 10, 4-oxa-2-butyl-2-ethyl-6, With diols such as 6-dimethylheptane-1,7-diol, the reaction proceeded under very mild conditions.

Melting point: After the diester was solidified at a low temperature, the temperature was raised and the melting point was determined from the melting start temperature and the melting end temperature.
Kinematic viscosity: Kinematic viscosity was determined according to JIS K2283 using an Ubbelohde viscometer.
Viscosity index: determined from kinematic viscosity at 40 ° C. and 100 ° C. according to JIS K2283

Examples 11-14 and Comparative Examples 8-9
Melting | fusing point was measured about the diester obtained in Examples 1-4 and Comparative Examples 1-2. For the sake of convenience, the melting point was set to −60 ° C. or lower for those that were not crystallized after being left overnight in a −78 ° C. bath.

  As shown in Table 4, the carboxylic acid esters of the comparative examples crystallize easily, but surprisingly, the carboxylic acid esters of Examples 1 to 4 can be left in a −78 ° C. bath overnight. It did not crystallize at all and was hardly crystalline.

Examples 15-18 and Comparative Examples 10-11
The kinematic viscosity was measured about the diester obtained in Examples 3-6 and Comparative Examples 2-3, and the viscosity index was calculated | required.

  As shown in Tables 5 and 6, in the esters with various carboxylic acids, the viscosity index is larger than the corresponding general-purpose 2,2-dimethylpropane-1,3-diol esters, and the improvement is It was seen.

  The ester compounds synthesized from the polyol of the present invention and various carboxylic acids / carboxylic esters are greases, refrigerator oils, insulating oils, hydraulic hydraulic oils, gear operating system lubricants, cutting / grinding oils, and transmission lubricants. Oil, wind power booster oil, internal combustion engine lubricating oil (engine oil), power turbine lubricating oil, compressor lubricating oil, bearing lubricating oil, and cosmetic raw materials used in various applications such as various cosmetics be able to.

Claims (11)

Ester compound represented by general formula (1)
In the formula, each of R ¹ and R ⁶ independently represents an alkyl group having 1 to 20 carbon atoms, an aralkyl group, or an aryl group. R ² , R ³ , R ⁴ and R ⁵ each independently represents an alkyl group having 1 to 10 carbon atoms. And the combination of R ² and R ^{3 and} the combination of R ⁴ and R ⁵ are different. The ester compound according to claim ¹ , wherein R ¹ and R ⁶ in formula (1) are alkyl groups having 1 to 20 carbon atoms, and R ² , R ³ , R ⁴ and R ⁵ are alkyl groups having 1 to 6 carbon atoms. The ester compound according to claim 1 or 2, wherein R ² and R ³ in the formula (1) are methyl groups. The ester compound according to any one of claims 1 to 3, wherein R ¹ and R ⁶ are the same in formula (1) and are an alkyl group having 1 to 12 carbon atoms.   Lubricating oil comprising the ester according to any one of claims 1 to 4.   Cosmetic raw material containing the ester according to any one of claims 1 to 4.   Cosmetics using the cosmetic raw material according to claim 6 Method for producing ester compound for obtaining ester compound represented by general formula (1) by dehydration condensation reaction of polyol represented by general formula (2) and carboxylic acid represented by general formula (3) and (4)
Here, in the general formula (2), R ² , R ³ , R ⁴ and R ⁵ each independently represent an alkyl group having 1 to 10 carbon atoms, and the combination of R ² and R ³ with R ⁴ and The combination of R ⁵ is different,
R ¹ COOH (3)
R ⁶ COOH (4)
In general formulas (3) and (4), R ¹ and R ⁶ each independently represents an alkyl group having 1 to 20 carbon atoms, an aralkyl group or an aryl group.
In the general formula (1), R ^{1 to} R ⁶ are as described above.   Catalysts in the dehydration condensation reaction are methanesulfonic acid, trifluoromethanesulfonic acid, p-toluenesulfonic acid, benzenesulfonic acid, dodecylbenzenesulfonic acid, sulfuric acid, solid acid catalyst containing sulfonic acid group, hydrochloric acid, phosphoric acid, titanium The method for producing an ester compound according to claim 8, which is at least one selected from tetramethoxide, titanium tetraethoxide, titanium tetraisopropoxide, titanium tetrabutoxide, dioctyltin oxide and dibutyltin oxide. Method for producing ester compound for obtaining ester compound represented by general formula (1) by transesterification reaction between polyol represented by general formula (2) and carboxylic acid ester of general formula (5) and (6)
Here, in the general formula (2), R ² , R ³ , R ⁴ and R ⁵ each independently represent an alkyl group having 1 to 10 carbon atoms, and the combination of R ² and R ³ with R ⁴ and The combination of R ⁵ is different,
R ¹ COOR ⁷ (5)
R ⁶ COOR ⁸ (6)
In general formulas (5) and (6), R ¹ and R ⁶ each independently represents an alkyl group having 1 to 20 carbon atoms, an aralkyl group, or an aryl group. R ⁷ and R ⁸ each independently represents an alkyl group having 1 to 4 carbon atoms.
In the general formula (1), R ^{1 to} R ⁶ are as described above.   The catalyst in the transesterification reaction is at least selected from sulfuric acid, p-toluenesulfonic acid, titanate ester, zinc acetylacetone, dibutyltin oxide, sodium hydrogen carbonate, sodium carbonate, potassium carbonate, sodium hydroxide, potassium hydroxide and sodium methoxide The method for producing an ester compound according to claim 10, wherein the number is one.