JPWO2016136623A1 - Lubricant composition - Google Patents

Abstract

An object of the present invention is to provide a lubricant composition having excellent nonflammability and stability, and capable of exhibiting excellent lubricating performance. The lubricant composition of the present invention contains at least a trihydric or higher polyhydric alcohol a1, a dihydric or higher polyhydric carboxylic acid a2, a composite ester A containing a polyester condensed with a monohydric alcohol a3, and water. A lubricant composition, wherein at least one selected from a trihydric or higher polyhydric alcohol a1 and a monohydric alcohol a3 has an oxyalkylene structure and the composite ester A is water-insoluble, an emulsifier and a glycol are added. Contains at least one selected from agents.

Description

  The present invention relates to a lubricant composition.

  Lubricants generally include base oils and various additives. Base oils include mineral oils obtained from crude oils, chemically synthesized ester oils, fluorine oils, polyalphaolefin oils, and the like. Among these, ester oils are suitably used for jet aircraft, automobile engine oils, greases and the like because of their low pour point, high viscosity index, high flash point, good lubricating performance, biodegradability, and the like.

  It is known that ester oils are used as base oils or additives. Examples of ester oils include monoesters obtained from the reaction of aliphatic monocarboxylic acids with monohydric alcohols; diesters obtained from the reaction of aliphatic dibasic acids with monohydric alcohols; polyhydric alcohols and aliphatic carboxylic acids. Various esters are disclosed (Patent Documents 1 to 8), such as an ester obtained from a reaction with A and a complex ester obtained from a reaction with a polyol, a polybasic acid and an aliphatic monocarboxylic acid.

  Esters containing complex esters and the like may be used by mixing with water. For example, Patent Documents 6 and 7 disclose a lubricant in which a composite ester containing a polyester having a predetermined structure is mixed with water to form an emulsion. Patent Document 8 discloses a lubricant in which a composite ester containing a polyester having a predetermined structure is mixed with water.

JP 2002-097482 A JP 2005-154726 A JP 2005-232434 A JP 2005-213377 A JP 2005-232470 A JP 2000-1691 A JP 2008-37928 A JP 2011-89106 A

  In general, many esters such as complex esters are insoluble in water, and are often mixed with base oils such as mineral oils. The lubricant thus obtained (hereinafter also referred to as a lubricant composition) is considered to exhibit good friction characteristics (low friction) even under severe conditions such as high temperature and high load. Are preferably used. However, under high temperature and extreme pressure conditions, there is a risk of ignition, and there has been concern about fire accidents caused by lubricants.

  On the other hand, as disclosed in Patent Documents 6 to 8, a lubricant composition in which an ester such as a complex ester and water are mixed is also used. In such a lubricant composition, although the risk of ignition is suppressed, the lubricating performance is often inferior, and further improvement has been demanded. In addition, in a lubricant composition in which an ester such as a composite ester is mixed with water, the stability of the composite ester may be impaired, and it is difficult to exhibit excellent lubricating performance over a long period of time. was there.

  In order to solve the problems of the prior art, the present inventors provide a lubricant composition that is excellent in nonflammability and stability and that can exhibit excellent lubricating performance. We proceeded with the study for the purpose of doing this.

As a result of intensive studies to solve the above problems, the present inventors have condensed at least a trihydric or higher polyhydric alcohol a1, a dihydric or higher polyvalent carboxylic acid a2, and a monohydric alcohol a3. In the lubricant composition containing the composite ester A containing polyester and water, at least one selected from a trihydric or higher polyhydric alcohol a1 and a monohydric alcohol a3 contains an oxyalkylene structure, thereby making it nonflammable. It was found that a lubricant composition having excellent stability and a lubricant composition capable of exhibiting excellent lubrication performance can be obtained.
Specifically, the present invention has the following configuration.

[1] A lubricant composition containing at least a trihydric or higher polyhydric alcohol a1, a divalent or higher polyhydric carboxylic acid a2 and a composite ester A containing a polyester condensed with a monohydric alcohol a3, and water. In the case where at least one selected from the trihydric or higher polyhydric alcohol a1 and the monohydric alcohol a3 has an oxyalkylene structure and the complex ester A is water-insoluble, at least selected from an emulsifier and a glycol additive A lubricant composition containing one kind.
[2] The lubricant composition according to [1], wherein the trihydric or higher polyhydric alcohol a1 has an oxyalkylene structure.
[3] The lubricant composition according to [1] or [2], wherein the monohydric alcohol a3 has an alkyl group having 8 or more carbon atoms.
[4] The lubricant composition according to any one of [1] to [3], wherein the lubricant composition contains an emulsifier, and the HLB value of the emulsifier is 4 or more.
[5] The lubricant composition according to any one of [1] to [4], wherein the lubricant composition contains an emulsifier, and the HLB value of the emulsifier is 7 or more.
[6] The lubricant composition according to any one of [1] to [5], wherein the divalent or higher polyvalent carboxylic acid a2 contains at least 75 mass% of a C36-44 divalent carboxylic acid.
[7] The lubricant composition according to any one of [1] to [3], wherein the water content is 43% by mass or more based on the total mass of the lubricant composition.
[8] The lubricant composition according to [7], wherein the trihydric or higher polyhydric alcohol a1 and the monohydric alcohol a3 have an oxyalkylene structure.
[9] The lubricant composition according to [8], wherein the polyhydric alcohol a1 has three or more oxyalkylene structures, and the monohydric alcohol a3 has three or more oxyalkylene structures.
[10] The lubricant composition contains a glycol additive, and the total content of water and the glycol additive is 50% by mass or more based on the total mass of the lubricant composition. The lubricant composition according to any one of the above.

  ADVANTAGE OF THE INVENTION According to this invention, it is a lubricant composition excellent in nonflammability and stability, Comprising: The lubricant composition which can exhibit the outstanding lubrication performance can be obtained.

  Hereinafter, the present invention will be described in detail. The constituent elements described below may be described based on representative embodiments and specific examples, but the present invention is not limited to such embodiments. In the present specification, a numerical range expressed using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

(Lubricant composition)
The lubricant composition of the present invention contains at least a trihydric or higher polyhydric alcohol a1, a dihydric or higher polyhydric carboxylic acid a2, a composite ester A containing a polyester condensed with a monohydric alcohol a3, and water. Here, at least one selected from the trihydric or higher polyhydric alcohol a1 and the monohydric alcohol a3 has an oxyalkylene structure. Moreover, when the composite ester A is water-insoluble, it contains at least one selected from an emulsifier and a glycol additive. Here, the water-soluble complex ester refers to a complex ester that dissolves 3% by mass or more in water at 25 ° C. In the present specification, a non-water-soluble complex ester is referred to as a water-insoluble complex ester.

  Since the lubricant composition of the present invention has the above-described configuration, it can be safely used even under conditions of fire with little risk of ignition. In addition, the composite ester A contained in the lubricant composition of the present invention has high stability even in the presence of water, and can exhibit excellent lubricating performance over a long period of time. Thus, the lubricant composition of the present invention is excellent in nonflammability and stability, and can exhibit excellent lubricating performance.

  In the lubricant composition of the present invention, the complex ester A may be water-soluble or water-insoluble. When the complex ester A is water-soluble, it may be dissolved in water in the lubricant composition to form an aqueous solution. When the composite ester A is water-insoluble, the lubricant composition contains at least one selected from an emulsifier and a glycol additive, and the composite ester A or the medium in which the composite ester A is dissolved is dispersed in water. And may be an emulsion. The lubricant composition of the present invention can exhibit excellent lubricating performance in any of such embodiments.

  In addition, content of the composite ester A in a lubricant composition should just be 0.1-50 mass% with respect to the total mass of a lubricant composition, and it is preferable that it is 0.5-50 mass%. 1 to 40% by mass is more preferable. By making content of the composite ester A in a lubricant composition into the said range, the lubricant composition of this invention can express favorable lubrication performance.

<Trivalent or higher polyhydric alcohol a1>
The trihydric or higher polyhydric alcohol a1 is a compound containing three or more in the molecule of at least one selected from alcoholic hydroxyl groups and phenolic hydroxyl groups. Among them, the trihydric or higher polyhydric alcohol a1 is preferably a compound containing three or more alcoholic hydroxyl groups, and more preferably a compound having 3 to 6 alcoholic hydroxyl groups.
Preferred trihydric or higher polyhydric alcohol a1 is an alcohol represented by the following general formula (a1-1a).

    In general formula (a1-1a), Z represents an m1-valent linking group, and m1 represents an integer of 3 or more.

The alcohol represented by the general formula (a1-1a) is an m1-valent alcohol.
In general formula (a1-1a), Z is an m1-valent linking group, and in other words, Z means a polyhydric alcohol mother nucleus formed by removing m1 hydroxyl groups from an m1-valent alcohol.

  In general formula (a1-1a), m1 represents an integer of 3 or more. m1 is preferably 3 to 6, more preferably 3 or 4.

  Z is an m1-valent linking group containing at least one trivalent or higher linking group. The trivalent or higher valent linking group is not particularly limited, and preferred examples thereof include a trivalent linking group containing a tertiary carbon atom and a tetravalent linking group containing a quaternary carbon atom.

The trivalent linking group containing a tertiary carbon atom preferably has the following structure, and R ^c in the following structure represents a hydrogen atom or a substituent.

  A quaternary carbon atom has the following structure:

Z is preferably at least one trivalent or higher linking group, an alkylene group, an arylene group, and an m1 valent linking group in which these groups are bonded. In the case where a plurality of alkylene groups and arylene groups are bonded, the alkylene group and arylene group are each a single bond or a divalent linking group (preferably -O-, -C (=) O-, -OC (=) O-, -S _{-, - SO 2 -, -} C (= O) -, - C (= O) NR b - (R b represents a hydrogen atom, an alkyl group, an aryl group)) or structures attached trivalent or more connecting group Preferably there is. The divalent linking group described above may further have a substituent. In addition, preferable Z is the residue remove | excluding the hydroxyl group from the preferable example of the polyhydric alcohol more than trivalence.

  Among these, Z is preferably a linking group having a neopentyl partial structure represented by the following structural formula (Z-1).

  In the structural formula (Z-1), * represents a bonding site with a hydroxyl group or another substituent.

Specific examples of the trihydric or higher polyhydric alcohol a1 include glycerin, 1,2,3-butanetriol, 1,2,4-butanetriol, 1,2,3-pentanetriol, 1,2,4. -Pentanetriol, 2-methyl-1,2,3-propanetriol, 2-methyl-2,3,4-butanetriol, 2-ethyl-1,2,3-butanetriol, 2,3,4-pentane Triol, 3-methylpentane-1,3,5-triol, 2,4-dimethyl-2,3,4-pentanetriol, 2,3,4-hexanetriol, 4-propyl-3,4,5-heptane Trivalent alcohols such as triol, 1,3,5-cyclohexanetriol, pentamethylglycerin, trimethylolethane, trimethylolpropane;
Tetrahydric alcohols such as 1,2,3,4-butanetetraol, pentaerythritol, diglycerin, sorbitan, ribose, arabinose, xylose, lyxose, ditrimethylolethane, ditrimethylolpropane;
Pentahydric alcohols such as arabitol, xylitol, glucose, fructose, galactose, mannose, allose, gulose, idose, talose;
Hexavalent alcohols such as dipentaerythritol, sorbitol, galactitol, mannitol, allitol, iditol, taritol, inositol, quercitol;
Mention may be made of octavalent alcohols such as tripentaerythritol.
Among these, trimethylolethane, trimethylolpropane, glycerol, pentaerythritol, ditrimethylolethane, ditrimethylolpropane, di- or tripentaerythritol are more preferable, trimethylolpropane, trimethylolethane, ditrimethylolpropane, glycerol, pentaerythritol, Dipentaerythritol is particularly preferred.

  As the trihydric or higher polyhydric alcohol a1, a compound obtained by adding alkylene oxide to at least one hydroxyl group of the trihydric or higher polyhydric alcohol described above (compound having an oxyalkylene structure) can also be preferably used. As the added alkylene oxide, ethylene oxide, propylene oxide, butylene oxide and a plurality of combinations thereof are preferable, and ethylene oxide and propylene oxide are more preferable.

When the trihydric or higher polyhydric alcohol a1 is a compound formed by adding an alkylene oxide as described above (a compound having an oxyalkylene structure), all of the hydroxyl groups of the trihydric or higher polyhydric alcohol are independently added to each other. Alkylene oxide is preferably added.
The number of added alkylene oxides (oxyalkylene structures) is preferably 3 to 300 on average in the above-described trihydric or higher polyhydric alcohol a1, and more preferably 6 to 100. Among them, the preferable number of added alkylene oxides is an average of 1 to 20 times, more preferably 2 to 10 times the number of hydroxyl groups of the trihydric or higher polyhydric alcohol a1, and particularly preferably. The number is 3 to 7 times.

  The above-mentioned alkylene oxide adduct (a compound having an oxyalkylene structure) of a trihydric or higher polyhydric alcohol a1 is preferably a compound represented by the following general formula (a1-1b).

In general formula (a1-1b), Z represents an m1-valent linking group, m1 represents an integer of 3 or more, R ¹¹ represents an alkylene group, and n1 represents an integer of 1 to 100.

Z and m1 in the general formula (a1-1b) have the same meanings as Z and m1 in the general formula a1-1a, respectively. Preferred Z is a residue obtained by removing a hydroxyl group from preferred examples of the trihydric or higher polyhydric alcohol.
R ¹¹ is an alkylene group, preferably an ethylene group, a propylene group or a butylene group, more preferably an ethylene group or a propylene group. A plurality of R ¹¹ may be the same or different.
n1 is an integer of 1 to 100, preferably 1 to 20, more preferably 2 to 10, and particularly preferably 3 to 7. A plurality of n1 may be the same or different.

  Specific examples of the trihydric or higher polyhydric alcohol a1 that can be used in the present invention are shown below, but the present invention is not limited thereto.

a1-1e is a compound having a number average molecular weight (Mn) = 450 and y11 + y12 + y13 = 7 (average value).
a1-1f is a compound having a number average molecular weight (Mn) = 797 and y31 + y32 + y33 + y34 = 15 (average value).

<Divalent or higher polyvalent carboxylic acid a2>
The divalent or higher polyvalent carboxylic acid a2 is a compound having two or more carboxyl groups or carboxylic acid precursor structures, preferably 2 to 4 carboxyl groups or carboxylic acid precursor structures, more preferably 2 or 3 It is a compound having two, more preferably two. Here, the precursor represents a group capable of forming an ester bond by reacting with a trihydric or higher polyhydric alcohol a1 or a monohydric or dihydric alcohol. That is, divalent or higher polyvalent carboxylic acid a2 having a carboxylic acid precursor structure includes carboxylic acid halide, carboxylic acid ester (preferably methyl ester, ethyl ester), carboxylic acid anhydride (preferably succinic anhydride), carboxylic acid It is preferably a mixed anhydride of an acid and another acid (preferably a sulfonic acid such as methanesulfonic acid or toluenesulfonic acid, or a substituted carboxylic acid such as trifluoroacetic acid). Hereinafter, the precursor thereof is also included in the detailed description of the divalent or higher polyvalent carboxylic acid a2.

  The carboxyl group in the molecule of the divalent or higher polyvalent carboxylic acid a2 is linked with a chain or cyclic divalent or higher aliphatic hydrocarbon or aromatic hydrocarbon. One or more carbon atoms not adjacent to each other of the carbon atoms of the aliphatic hydrocarbon or aromatic hydrocarbon linking group may be substituted with oxygen atoms. Among these, the divalent or higher polyvalent carboxylic acid a2 preferably has a branched alkyl group from the viewpoint of lubricity.

  Examples of the divalent or higher polyvalent carboxylic acid a2 that can be used in the present invention include terephthalic acid, phthalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, and dodecanedione. Acid, trimellitic acid, dimer acid (dimer of unsaturated carboxylic acid having 18 carbon atoms), hydrogenated dimer acid, trimer acid (trimer of unsaturated carboxylic acid having 18 carbon atoms), carbon number 22 dimers (for example, erucic acid dimer) of unsaturated carboxylic acid.

  As the divalent or higher polyvalent carboxylic acid a2, an anhydride of a polyvalent carboxylic acid can also be used. The polyhydric carboxylic acid anhydride is a product obtained by intramolecular or intermolecular dehydration condensation of two COOHs of the above polycarboxylic acid. Examples of anhydrides include succinic anhydride, glutaric anhydride, adipic anhydride, maleic anhydride, phthalic anhydride, nado anhydride, methyl nadic anhydride, hexahydrophthalic anhydride and mixed polybasic anhydrides Is included.

  Specific examples of the divalent or higher polyvalent carboxylic acid a2 that can be used in the present invention are shown below, but the present invention is not limited thereto.

<Monohydric alcohol a3>
The monohydric alcohol a3 is a compound containing one hydroxyl group in one molecule. The monohydric alcohol a3 is represented by R—OH. R is a monovalent aliphatic, alicyclic or aromatic ring group, and one or more carbon atoms which are not adjacent to each other in R may be substituted with an oxygen atom. R preferably has 4 or more carbon atoms, more preferably 6 or more, and particularly preferably 8 or more. By setting the carbon number of the monohydric alcohol within the above range, the friction characteristics can be improved. Furthermore, the monohydric alcohol a3 can be prevented from evaporating during the condensation reaction.

  The monohydric alcohol a3 has (i) an alkyl group having 8 or more carbon atoms, (ii) a branched alkyl group, or (iii) an oxyalkylene structure, (i) It is preferable that at least two conditions of (iii) are satisfied. In particular, when the lubricant composition is insoluble in water, it preferably satisfies at least one condition (i) to (iii), and satisfies at least two conditions (i) to (iii). Is more preferable, and it is more preferable that all the conditions are satisfied. Moreover, when the lubricant composition is water-soluble, it is preferable that at least the condition (iii) is satisfied.

  Examples of the monohydric alcohol a3 suitable for the present invention include methanol, ethanol, butanol, isobutanol, pentanol, propanol, hexanol, 2-ethylhexanol, heptanol, octanol, decanol, dodecanol, hexadecanol, octadecanol, Examples include 2-heptylundecanol, eicosadecanol, phytosterol, isostearyl alcohol, stearol, cetol, behenol, or alkylene oxide adducts (compounds having an oxyalkylene structure) of these monohydric alcohols.

  The monohydric alcohol a3 used in the present invention preferably has an oxyalkylene structure, and more preferably is represented by the following general formula (3).

Here, in the general formula (3), Ra represents an alkyl group which may have ^a substituent, ^a cycloalkyl group which may have a substituent, an alkenyl group which may have a substituent, or a substituent. An aryl group which may have or a heteroaryl group which may have a substituent, and X ^a1 and X ^a2 each independently represent a hydrogen atom, a halogen atom or an alkyl group; Na1 represents an integer of 2 to 4, and na2 represents an integer of 1 to 20.

That the number of carbon atoms of the alkyl moiety of the alkyl group which may have a substituent represented by R ^a is preferably 1 to 25, more preferably from 4-22, 6-20 Is more preferable. The alkyl group represented by R ^a may be linear or branched, but when the lubricant composition is an emulsion, a branched alkyl group is preferred from the viewpoint of affinity for the base oil. R ^a may be a cycloalkyl group which may have ^a substituent.

The number of carbon atoms of the alkenyl group moiety alkenyl group which may have a substituent represented by R ^a is preferably 3 to 22, more preferably from 4 to 18, is 8 to 18 Is more preferable. The alkenyl group represented by R ^a may be linear, branched or cyclic.

The number of carbon atoms of the aryl moiety of the aryl group or heteroaryl group which may have a substituent represented by R ^a is preferably 6 to 17, and more preferably 6-12. Examples of the aryl group represented by ^Ra include a phenyl group and a naphthyl group, and among them, a phenyl group is particularly preferable. Examples of the heteroaryl group represented by ^Ra include imidazolyl, pyridyl, quinolyl, furyl, thienyl, benzoxazolyl, indolyl, benzimidazolyl, benzthiazolyl, carbazolyl, azepinyl Can be illustrated. The hetero atom contained in the heteroaryl group is preferably an oxygen atom, a sulfur atom, or a nitrogen atom, and more preferably an oxygen atom.

Especially, in General formula (3), it is more preferable that ^Ra is an alkyl group which may have ^a substituent.

Examples of the substituent that R ^a may have include a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms (for example, methyl, ethyl, which are both linear or branched propyl, butyl, Pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, heneicosyl, docosyl, tricosyl, or tetracosyl); alkenyl having 2 to 35 carbon atoms Groups (eg, propenyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl); cycloalkyl groups having 3 to 10 carbon atoms (eg, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl) Cycloheptyl); an aromatic ring group having 6 to 30 carbon atoms (for example, phenyl, naphthyl, biphenyl, phenanthryl, anthracenyl), a heterocyclic group (nitrogen atom, oxygen atom, and sulfur atom) Or a heterocyclic residue containing, for example, pyridyl, pyrimidyl, triazinyl, thienyl, furyl, pyrrolyl, pyrazolyl, imidazolyl, triazolyl, thiazolyl, imidazolyl, oxazolyl, thiadialyl, oxadiazolyl, quinolyl, isoquinolyl); Represents a group consisting of If possible, these substituents may further have one or more substituents. Examples of the substituents include alkoxy groups, alkoxycarbonyl groups, halogen atoms, ether groups, alkylcarbonyl groups, cyano groups. Group, thioether group, sulfoxide group, sulfonyl group, amide group and the like.

In the general formula (3), X ^a1 and X ^a2 each independently represent a hydrogen atom, a halogen atom or an alkyl group, and more preferably a hydrogen atom or an alkyl group. ^Examples of the alkyl group represented by X ^a1 and X ^a2 include an alkyl group represented by R ^a .

In general (3), na1 represents an integer of 2 to 4, more preferably an integer of 2 or 3, and still more preferably 2.
Na2 represents an integer of 1 to 20, more preferably an integer of 1 to 15, further preferably an integer of 1 to 10, and particularly preferably an integer of 1 to 7.

  The carbon number of the monohydric alcohol represented by the general formula (3) is preferably 4 or more, more preferably 6 or more, and particularly preferably 8 or more. By using such a monohydric alcohol, it is possible to improve the frictional properties and to suppress the monohydric alcohol from being volatilized during the condensation reaction.

  Specific examples of the monohydric alcohol a3 that can be used in the present invention are shown below, but the present invention is not limited thereto.

y51 to y53 are each independently preferably an integer of 1 to 30, more preferably an integer of 1 to 20, and still more preferably an integer of 3 to 15. Moreover, y54 is preferably an integer of 1 to 30, and more preferably an integer of 3 to 20.

<Other ingredients>
The composite ester A may be further condensed with components other than the components a1 to a3. Such components include dihydric alcohols (preferably aliphatic dihydric alcohols having 2 to 50 carbon atoms), monovalent or polyvalent amines that can be condensed with carboxylic acids to form amide bonds, and monovalent carboxylic acids. Is mentioned.

(Method for producing complex ester A)
The composite ester A is obtained by condensing at least a trihydric or higher polyhydric alcohol a1, a divalent or higher polyvalent carboxylic acid a2, and a monohydric alcohol a3.

As the charging ratio when performing the condensation reaction, it is preferable to condense at least the components a1 to a3 at a molar ratio of carboxyl group / hydroxyl group of all carboxylic acids and all alcohols at 2/1 to 1/2, more preferably. The molar ratio is 1.5 / 1 to 1 / 1.5, more preferably 1/1 to 1 / 1.3, particularly preferably 1/1 to 1 / 1.2. When the alcohol is used in excess, the acid value of the condensate can be lowered, and damage to the member can be suppressed when used as a lubricant.
Moreover, the preferable preparation ratio of a1: a3 is 1: 1-1: 10 by mole ratio, More preferably, it is 1: 2-1: 5, More preferably, it is 1: 2.5-1: 4.

The composite ester A is obtained by subjecting the mixture prepared as described above to a condensation reaction in the presence or absence of a catalyst or a condensing agent.
In the condensation, it is desirable to heat or to make an appropriate amount of a solvent azeotropic with water or a low molecular alcohol. Thereby, the reaction proceeds smoothly without coloring the product. This solvent is preferably a hydrocarbon solvent having a boiling point of 100 to 200 ° C, more preferably a hydrocarbon solvent having a boiling point of 100 to 170 ° C, and most preferably a hydrocarbon solvent having a boiling point of 110 to 160 ° C. Examples of these solvents include toluene, xylene, mesitylene and the like. If the amount to be added is too large, the liquid temperature will be in the vicinity of the solvent and condensation will not proceed easily. On the other hand, if the amount is too small, azeotropy does not go smoothly. Therefore, the addition amount is preferably 1 to 25% by mass, more preferably 2 to 20% by mass, particularly preferably 3 to 15% by mass, and also preferably 5 to 12% by mass with respect to the total amount of the raw material.

  Although the reaction is accelerated by using the catalyst, it is desirable not to use it because the post-treatment of removing the catalyst is complicated and causes coloring of the product. However, when used, a normal catalyst is used, and normal conditions and operations can be employed. In this regard, reference can be made to Japanese Patent Publication Nos. 2001-501989, 2001-500499, 2001-507334, and 2002-509563.

  After completion of the preparation, the reaction is carried out at a liquid temperature of 120 to 250 ° C, preferably 130 to 230 ° C, more preferably 150 to 230 ° C, and particularly preferably 170 to 230 ° C. As a result, a solvent containing water or a low molecular alcohol is azeotroped, cooled at the cooling site, and separated into a liquid. This water may be removed. After reacting at a low temperature, the reaction may be performed at a higher temperature.

  As for the reaction time, since the theoretically generated water amount is calculated from the number of moles charged, it is preferable to carry out the reaction until the water amount is obtained, but it is difficult to complete the reaction completely. Even when the reaction is terminated when the theoretical water generation amount is 60 to 90%, the lubricity of the obtained lubricant composition containing the composite ester A is good. The reaction time is 1 to 24 hours, preferably 3 to 18 hours, more preferably 5 to 18 hours, and most preferably 6 to 15 hours.

(Composite ester A)
The composite ester A is a product obtained by randomly condensing at least a trihydric or higher polyhydric alcohol a1, a dihydric or higher polyvalent carboxylic acid a2, and a monohydric alcohol a3. , A light component having only one structure derived from the component a2, and an oligomer or polymer component having two or more structures derived from the component a2. Specific examples of the light component include a monoester or a diester produced by a reaction between the polyvalent carboxylic acid a2 and the monohydric alcohol a3. The content of the oligomer or polymer component excluding the light component is preferably 50% or more, more preferably 60 to 85%, still more preferably 65 to 80% in terms of the area ratio of GPC (gel permeation chromatography). The GPC measurement conditions may be those described later.
The complex ester A may contain an unreacted a3 component. The content of the unreacted a3 component with respect to the total amount of the complex ester A is preferably 10% or less, more preferably 6% or less, and particularly preferably 4% or less. The content of the unreacted a3 component can be calculated using the area ratio of the molecular weight peak corresponding to a3 in GPC measurement.

The kinematic viscosity at 40 ° C. of the composite ester A is preferably 50 to 2000 mm ² / s. The kinematic viscosity at 40 ° C. of the composite ester A is preferably 50 mm ² / s or more, more preferably 70 mm ² / s or more, and further preferably 100 mm ² / s or more. The kinematic viscosity at 40 ° C. of the composite ester A is preferably 2000 mm ² / s or less, more preferably 1500 mm ² / s or less, and still more preferably 1000 mm ² / s or less. By setting the kinematic viscosity of the composite ester A within the above range, the coefficient of friction of the lubricant composition can be kept low, thereby improving the lubricity. In this specification, the kinematic viscosity at 40 ° C. of the composite ester A is specifically a value measured in a constant temperature water bath at 40.0 ° C. using an Ubbelohde viscometer.

The molecular weight of the complex ester A is preferably a weight average molecular weight in terms of standard polystyrene using gel permeation chromatography (GPC), preferably from 1,000 to 100,000, more preferably from 2,000 to 20,000, and even more preferably from 3,000 to 10,000. By setting the molecular weight within the above range, good lubricating performance can be obtained with low viscosity. In the present specification, the weight average molecular weight in terms of polystyrene of the complex ester A is specifically a value measured under the following conditions.
“HLC-8220GPC (manufactured by Tosoh Corporation)” is used as the apparatus. Columns are “TSKgel, SuperHZM-H (manufactured by Tosoh Corporation, 4.6 mm ID × 15 cm)”, “TSKgel, SuperHZ4000 (manufactured by Tosoh Corporation, 4.6 mmID × 15 cm)”, TSKgel, SuperHZ2000 (Tosoh Corporation) 3 ", 4.6 mm ID x 15 cm)" is used.

As GPC conditions, for example, the following conditions can be employed.
・ Eluent THF (tetrahydrofuran)
・ Flow rate 0.35ml / min
・ Measurement temperature 40 ℃ (column, inlet, RI)
・ Analysis time 20 minutes ・ Sample concentration 0.1%
・ Sample injection volume 10μl

  In the present invention, unreacted COOH may remain in the composite ester A, or OH may exist. However, when OH and COOH remain, the hydroxyl value and the acid value increase, depending on the application. May not be preferred. In such a case, OH and COOH can be eliminated by separate acylation and / or esterification treatment, and the hydroxyl value and acid value can be reduced.

The ratio of the unreacted OH group of the complex ester A is determined by measuring ¹³ C-NMR. The residual ratio of OH groups in the composite ester A is preferably 0 to 40%, more preferably 0 to 35%, and further preferably 0 to 30%.

  The acid value of complex ester A (mg number of KOH required to neutralize 1 g of sample) is preferably 0 to 50 mg KOH, more preferably 0 to 30 mg KOH, and 0 to 20 mg KOH. More preferably. However, it is not limited to this range. In the present specification, specifically, the acid value of the complex ester A (the number of mg of KOH required to neutralize 1 g of the sample) can be a value measured according to the JIS K2501 method.

  After completion of the reaction and the treatment after the reaction, it is preferable to perform filtration to remove dust and the like. When the product becomes solid, it can be melted out or taken out as a powder by reprecipitation.

Specific embodiments of the lubricant composition of the present invention include the following embodiments (1) to (3). When the composite ester A is water-insoluble, the lubricant composition contains at least one selected from an emulsifier and a glycol additive (modes (1) and (2) of the lubricant composition).
Aspect (1): A lubricant composition containing at least complex ester A, an emulsifier (preferably an HLB (Hydrophile-Lipophile Balance) value of 4 or more), and water.
Aspect (2): A lubricant composition containing at least complex ester A, a glycol additive (preferably mono- or diethylene glycol, mono- or dipropylene glycol), and water.
Aspect (3): A lubricant composition containing at least the complex ester A and water, wherein the complex ester A is water-soluble, and the water content is more than 40% by mass.
In the following, preferred embodiments are described in detail.

<Aspect (1)>
The lubricant composition of aspect (1) is a lubricant composition containing at least the complex ester A, an emulsifier (preferably an HLB value of 4 or more) and water.
The complex ester A in the embodiment (1) is preferably water-insoluble, and from the viewpoint of affinity for base oil, the polyvalent carboxylic acid a2 used preferably has 4 or more carbon atoms, and preferably 8 or more. Is preferably 18 or more, more preferably 22 or more, particularly preferably 26 or more, and particularly preferably 36 or more. The number of carbon atoms of the divalent or higher polyvalent carboxylic acid is preferably 70 or less, more preferably 66 or less, and even more preferably 59 or less. In the present invention, the carbon number of a divalent or higher polyvalent carboxylic acid means the number of carbon atoms including the carbon atom constituting the carboxyl group. Thus, lubricity can be improved more by making carbon number of polyvalent carboxylic acid more than bivalence into the said range.

  The divalent or higher polyvalent carboxylic acid a2 preferably contains at least 75% by mass of a C 36-44 divalent carboxylic acid. That is, the polyvalent carboxylic acid a2 having 2 or more valences is preferably a polymerization reaction mixture of unsaturated fatty acids having 18 to 22 carbon atoms and a mixture obtained by hydrogenating the polymerization reaction mixture. For example, dimer acid is an aliphatic or alicyclic dicarboxylic acid produced by dimerization of unsaturated fatty acid (usually 18 carbon atoms) by polymerization or Diels-Alder reaction (most dimers, 3 Many of them contain several mole% of monomers, monomers, etc.), and among them, those whose main components are trimers are defined as trimer acids. As described above, during the polymerization reaction, there may be a case where a monovalent carboxylic acid or a trivalent carboxylic acid is contained in addition to the divalent carboxylic acid. It is preferable to use what is.

Specific examples of the polymerization reaction mixture of unsaturated fatty acids having 18 to 22 carbon atoms include dimer acid, hydrogenated dimer acid, trimer acid, and erucic acid dimer.
As specific examples of dimer acid or trimer acid, Tsunodim (registered trademark) 205, 216, 228, and 395 manufactured by Tsukino Food Industry Co., Ltd. can be exemplified as dimer acid, and tunodim 345 and the like can be exemplified as trimer acid. In addition, products of Cognis and Unikema may be used.
A specific example of the polymerization reaction mixture of unsaturated fatty acids having 22 carbon atoms is a dimerized product of erucic acid, and a specific example is Pripol 1004 manufactured by Croda.

  The monohydric alcohol a3 to be used preferably has an alkyl group, and more preferably has a branched alkyl group. Moreover, the carbon number of the alkyl group is preferably 8 or more, and more preferably 10 or more. By setting the carbon number of the monohydric alcohol a3 within the above range, the affinity for the base oil can be increased and the frictional characteristics can also be improved.

  The content of the complex ester A in the aspect (1) is preferably 0.1 to 50% by mass, more preferably 0.5 to 50% by mass, and 1 to 40% by mass with respect to the total composition. % Is more preferable, and 1 to 35% by mass is particularly preferable.

  Examples of the emulsifier include a cationic surfactant, an anionic surfactant, and a nonionic surfactant, and a nonionic surfactant is preferable. The emulsifier is preferably an emulsifier having an HLB value of 4 or more, more preferably 7 or more. Here, the HLB value is a numerical value representing the hydrophilic / lipophilic balance of the surfactant. The higher the hydrophilicity of the surfactant with respect to the lipophilicity, the higher the HLB value, and the more emulsifying agent is easily soluble in water. By selecting an appropriate HLB value, the lubricity and stability of the lubricant composition are improved.

  Specific examples of the emulsifier include nonionic surfactants such as polyoxyalkylene alkyl (phenyl) ethers, cationic surfactants such as fatty acid alkanolamine salts, and anionic surfactants such as fatty acid soaps and sulfonates. Preferably, polyoxyethylene sorbitan monoester, polyoxyethylene sorbitan diester, polyoxyethylene sorbitan triester, polyoxyalkylene alkyl ether, polyoxyalkylene alkyl aryl ether, polyoxyalkylene aryl ether, fatty acid diethanolamide and the like are mentioned. It is done. Of these, those having a polyoxyethylene structure are particularly preferred.

The content of the emulsifier in the aspect (1) is preferably 1 to 40% by mass and more preferably 3 to 35% by mass with respect to the total mass of the lubricant composition.
The water content in the aspect (1) is preferably 10 to 70% by mass, more preferably 20 to 65% by mass, based on the total mass of the lubricant composition.

  In the aspect (1), a lubricant composition further containing a base oil is also preferable. Base oils include mineral oils, fat compounds, polyolefin oils (eg polyalphaolefins), silicone oils, perfluoropolyether oils, ester oils (eg aromatic ester oils, monovalent fatty acid esters, divalent fatty acid diesters, polyol esters). Lubricating oil) and one or more selected from diphenyl ether derivatives. A preferable content of the base oil in the aspect (1) is 5 to 70% by mass, preferably 10 to 50% by mass, based on the total mass of the lubricant composition.

  In the lubricant composition of the aspect (1), all the components may be mixed at the same time, or further components may be mixed in the liquid in which a plurality of components are mixed. For example, you may mix the liquid which mixed the base oil and the composite ester A, and the liquid which mixed water and the emulsifier before use. After mixing, it is preferable to stir well and use in an emulsified state.

<Aspect (2)>
The lubricant composition of aspect (2) is a lubricant composition containing at least complex ester A, a glycol additive, and water. In the embodiment (2), the complex ester A may be water-insoluble or water-soluble, but is preferably dissolved in 5% by mass or more in a mixed solution of water and a glycol additive.

  The content of the complex ester A in the aspect (2) is preferably 0.1 to 50% by mass and more preferably 0.5 to 50% by mass with respect to the total mass of the lubricant composition. 1 to 40% by mass is more preferable, and 1 to 15% by mass is particularly preferable.

  Preferred examples of the glycol additive include monoethylene glycol, diethylene glycol, monopropylene glycol, and dipropylene glycol. In addition, in aspect (2), you may contain polyalkylene glycol further. Examples of the polyalkylene glycol include polyethylene glycol (PEG: average molecular weight 300 to 100,000).

  A preferable content of the glycol additive in the aspect (2) is 10 to 60% by mass, and more preferably 15 to 50% by mass with respect to the total composition. In the aspect (2), when the lubricant composition further contains a polyalkylene glycol, the total mass of the glycol additive containing the polyalkylene glycol is preferably within the above range. In the aspect (2), the lubricating performance of the lubricant composition can be further improved by containing the glycol additive so as to be within the above range.

  In aspect (2), the lubricant composition does not substantially contain a base oil such as mineral oil. Here, the state containing substantially no base oil means that the content of the base oil in the lubricant composition is 0.1% by mass or less with respect to the total mass of the lubricant composition. .

The preferable content of water in the aspect (2) is 10 to 60% by mass, and more preferably 20 to 50% by mass with respect to the total composition.
In aspect (2), the total content of water and glycol additives is preferably 50% by mass or more, more preferably 70% by mass or more, based on the total mass of the lubricant composition. 80% by mass or more is more preferable.

  In the lubricant composition of the aspect (2), all the components may be mixed at the same time, or further components may be mixed later in the liquid in which a plurality of components are mixed. For example, the complex ester may be mixed later in a liquid obtained by mixing water, a glycol additive, and other components.

<Aspect (3)>
The lubricant composition of aspect (3) is a lubricant composition containing at least the composite ester A and water, wherein the composite ester A is water-soluble and the water content is more than 40% by mass. In aspect (3), the lubricant composition does not substantially contain a base oil such as mineral oil. Here, the state containing substantially no base oil means that the content of the base oil in the lubricant composition is 0.1% by mass or less with respect to the total mass of the lubricant composition. .

  The content of the complex ester A in the aspect (3) is preferably 0.1 to 50% by mass, more preferably 0.5 to 50% by mass with respect to the total mass of the lubricant composition. It is more preferable that it is 1-40 mass%, and it is especially preferable that it is 5-35 mass%.

  A preferable content of water in the aspect (3) is preferably 43% by mass or more, more preferably 43 to 95% by mass, and more preferably 45 to 90% by mass with respect to the total mass of the lubricant composition. Is more preferable, and it is especially preferable that it is 50-90 mass%.

  In the lubricant composition of aspect (3), it is preferable that both the trihydric or higher polyhydric alcohol a1 and the monohydric alcohol a3 have an oxyalkylene structure. Such a lubricant composition is easily dissolved in water and can exhibit good lubricating performance in the state of an aqueous solution.

  In the lubricant composition of the aspect (3), the trihydric or higher polyhydric alcohol a1 preferably has 3 or more oxyalkylene structures, more preferably 5 or more, and more preferably 10 or more. Further preferred. Furthermore, the monohydric alcohol a3 also preferably has 3 or more oxyalkylene structures, more preferably 5 or more, and still more preferably 10 or more.

  In the lubricant composition of aspect (3), the carbon number of the divalent or higher polyvalent carboxylic acid a2 is preferably 8 or less. As the divalent or higher polyvalent carboxylic acid a2, an anhydride of a polyvalent carboxylic acid is preferably used. In particular, succinic anhydride is preferably used.

  In the lubricant composition of the aspect (3), all the components may be mixed at the same time, or further components may be mixed later in the liquid obtained by mixing a plurality of components. For example, the composite ester A may be mixed later in a liquid in which water and other components are mixed. It is preferable to mix well after mixing and use in a dissolved state.

<Other components in the lubricant composition>
The lubricant composition of the aspects (1) to (3) contains various additives such as a rust inhibitor, an antifoaming agent, a pour point depressant, an antiseptic, an extreme pressure agent, and a friction modifier as further components. Is preferred.

(Use of lubricant composition)
The lubricant composition of the present invention can be supplied, for example, between two sliding surfaces and used to reduce friction. The lubricant composition of the present invention can form a film on the sliding surface. As for the material of the sliding surface, in steel, specifically, carbon steel for machine structure, alloy steel for structural machinery such as nickel chrome steel, nickel chrome molybdenum steel, chrome steel, chrome molybdenum steel, aluminum chrome molybdenum steel, Examples include stainless steel and multi-aged steel.

As the material of the sliding surface, various metals other than steel, or inorganic or organic materials other than metals are widely used. Examples of inorganic or organic materials other than metals include various plastics, ceramics, carbon, etc., and mixtures thereof. More specifically, examples of the metal material other than steel include cast iron, copper / copper-lead / aluminum alloy, castings thereof, and white metal.
In addition, about the material of a sliding surface, description of Paragraphs 0168-0175 of Unexamined-Japanese-Patent No. 2011-89106 can be referred.

  The lubricant composition of the present invention can be used for various applications. For example, it is preferably used as a hydraulic operation lubricant, a cutting lubricant, and a metal working lubricant.

Moreover, the lubricant composition of the present invention can be used for various applications as a release agent. For example, polycarbonate resin, flame retardant polycarbonate resin, crystalline polyester resin which is the main component of image forming toner used in electrophotographic apparatus and electrostatic recording apparatus, various molding thermoplastic resin compositions and semiconductor encapsulating Used as a mold release agent for epoxy resin compositions.
Moreover, it can also be used as an antifouling agent that promotes the detachment of dirt adhering to the fiber product and prevents the fiber product from being soiled by being kneaded or applied in advance to a textile product such as clothing.

  The features of the present invention will be described more specifically with reference to examples and comparative examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.

(Composite ester Aa)
Ethylene oxide adduct of trimethylolpropane (Aldrich, average molecular weight 450), dimer of C22 unsaturated fatty acid (CRODA, PRIPOL 1004), diethylene glycol mono-2-ethylhexyl ether (Wako Pure Chemical Industries) A reaction vessel equipped with a Dean-Stark dehydrator at a molar ratio of 1.17 / 3 / 3.5 was charged. The reaction was performed at 190 ° C. for 5 hours and further at 220 ° C. for 4 hours under a nitrogen stream of 0.3 L / min. Water generated during the reaction was removed. After cooling to room temperature, composite ester Aa was obtained. The complex ester Aa was insoluble in water.

(Composite ester Ab)
Trimethylolpropane (manufactured by Wako Pure Chemical Industries, Ltd.), dimer acid (manufactured by Tsuno Food Co., Ltd., Tsunodim 395), ethylene glycol mono-2-ethylhexyl ether (manufactured by Wako Pure Chemical Industries, Ltd.) in a molar ratio of 1.17 / 3/3. A reaction vessel equipped with a Dean-Stark dehydrator at a ratio of 5 was charged. The reaction was performed at 190 ° C. for 5 hours and further at 220 ° C. for 4 hours under a nitrogen stream of 0.3 L / min. Water generated during the reaction was removed. The mixture was allowed to cool to room temperature to obtain a complex ester Ab. The complex ester Ab was insoluble in water.

(Composite ester Ac)
Triethylene glycol monoethyl ether, succinic anhydride, and pentaerythritol were charged at a molar ratio of 5/4/1 into a reaction vessel equipped with a Dean-Stark dehydrator. The reaction was performed at 190 ° C. for 5 hours and further at 220 ° C. for 4 hours under a nitrogen stream of 0.3 L / min. Water generated during the reaction was removed. The mixture was allowed to cool to room temperature to obtain a complex ester Ac. The complex ester Ac was insoluble in water.

(Composite ester Ad)
Ethylene oxide adduct of trimethylolpropane (Aldrich, average molecular weight 1014), succinic anhydride, polyethylene glycol monomethyl ether (Aldrich, average molecular weight 750) at a molar ratio of 1.17 / 3 / 3.5. A reaction vessel equipped with a Dean-Stark dehydrator was charged. The reaction was performed at 190 ° C. for 5 hours and further at 220 ° C. for 4 hours under a nitrogen stream of 0.3 L / min. Water generated during the reaction was removed. The mixture was allowed to cool to room temperature to obtain a complex ester Ad. The complex ester Ad was water soluble.

(Comparative Compound Xa)
In the synthesis of the composite ester Ab, a comparative compound Xa was obtained using the same method as the synthesis of the composite ester Ab, except that 2-ethylhexyl alcohol having no oxyalkylene structure was used instead of ethylene glycol mono-2-ethylhexyl ether. .

(Examples 1-1 to 1-7 and Comparative Examples c1 to c5)
The lubricant compositions of Examples 1-1 to 1-7 and Comparative Examples c1 to c5 were prepared by mixing at a ratio shown in Table 1 and sufficiently stirring.

(Evaluation)
<Stability>
Observe the appearance of the liquid when the prepared lubricant composition was left in a sample bottle for 24 hours. The separated one was evaluated as C. In addition, the evaluation more than B was made into the pass level.

<Nonflammable>
2 ml of the prepared lubricant composition was soaked in a 1 cm × 10 cm glass filter paper and hung sideways. One end of the glass filter paper was ignited with a burner for 3 seconds, and then the burner was released. The fire extinguisher immediately after release was designated as A, and the fire extinguished even after releasing the burner was designated as C. In addition, A evaluation was made into the pass level.

<Friction characteristics>
About the lubricant composition of each Example and Comparative Example, using a vibration type frictional wear tester (manufactured by Optimol Instruments Prutechnik GmbH, trade name: SRV 4), the temperature was set at a frequency of 50 Hz, a load of 10 N, and an amplitude of 1 mm. A friction and wear test was performed at 40 ° C. for 1 hour, and the coefficient of friction at 30 minutes was measured. As the upper test piece, a 10 mm SUJ-2 ball and a lower test piece 24 mm SUJ-2 disk were used. The observed coefficient of friction was evaluated according to the following criteria. The results are shown in the table.
Other evaluation results were normalized by setting the friction coefficient of Comparative Example c1 to 100% and evaluated as follows. The smaller the value, the smaller the coefficient of friction, indicating better lubricating performance. For a and b, the coefficient of friction was greatly reduced, and it was judged that the improvement effect was great. Although a decrease in the friction coefficient was observed for c, the effect was small, and it was determined that d was equal to or less than that of Comparative Example 1 and no improvement was observed. In addition, evaluation more than b was made into the pass level.
a: Less than 70% b: 70% or more and less than 80% c: 80% or more and less than 95% d: 95% or more

乳化剤
ＥＭ１：ソルビタントリオレート（ＨＬＢ値３）
ＥＭ２：ポリエチレングリコールジステアレート（ＨＬＢ値６）
ＥＭ３ソルビタンモノラウレート（ＨＬＢ値９）
ＥＭ４：ポリオキシエチレンソルビタンオレート（ＨＬＢ値１５）
ＥＭ５：ポリエチレングリコール−２−エチルヘキシルエーテル（ＨＬＢ値１５）
鉱油：ＪＸ日鉱日石エネルギー社製スーパーオイルＮ４６

Emulsifier EM1: sorbitan trioleate (HLB value 3)
EM2: Polyethylene glycol distearate (HLB value 6)
EM3 sorbitan monolaurate (HLB value 9)
EM4: polyoxyethylene sorbitan oleate (HLB value 15)
EM5: Polyethylene glycol-2-ethylhexyl ether (HLB value 15)
Mineral oil: JX Nippon Oil & Energy Super Oil N46

(Examples 2-1 to 2-7 and comparative examples d1 and d2)
The lubricant compositions of Examples 2-1 to 2-7 and Comparative Examples d1 and d2 were prepared by mixing at a ratio shown in Table 2 and sufficiently stirring.

  In Table 2, stability and incombustibility were evaluated by the same evaluation method as the above method. The friction characteristics were standardized with the comparative example d1 as 100% and evaluated by the same evaluation method as the above method.

ＰＥＧ：ポリエチレングリコール（平均分子量５００００）
ＥＧ：エチレングリコール

PEG: Polyethylene glycol (average molecular weight 50000)
EG: Ethylene glycol

(Examples 3-1 to 3-3 and comparative examples e1 and e2)
The lubricant compositions of Examples 3-1 to 3-3 and Comparative Examples e1 and e2 were prepared by mixing at a ratio shown in Table 3 and sufficiently stirring.

  In Table 3, stability and incombustibility were evaluated by the same evaluation method as the above method. The friction characteristics were standardized with Comparative Example e1 as 100%, and evaluated by the same evaluation method as the above method.

  In the lubricant compositions obtained in the examples, nonflammability and stability are high, and excellent lubrication performance is obtained.

Claims (10)

A lubricant composition comprising at least a trihydric or higher polyhydric alcohol a1, a dihydric or higher polyhydric carboxylic acid a2 and a composite ester A comprising a polyester condensed with a monohydric alcohol a3, and water,
At least one selected from the trihydric or higher polyhydric alcohol a1 and the monohydric alcohol a3 has an oxyalkylene structure;
When the composite ester A is water-insoluble, a lubricant composition containing at least one selected from an emulsifier and a glycol additive.   The lubricant composition according to claim 1, wherein the trihydric or higher polyhydric alcohol a1 has an oxyalkylene structure.   The lubricant composition according to claim 1 or 2, wherein the monohydric alcohol a3 has an alkyl group having 8 or more carbon atoms.   The lubricant composition according to any one of claims 1 to 3, wherein the lubricant composition contains an emulsifier, and the emulsifier has an HLB value of 4 or more.   The lubricant composition according to any one of claims 1 to 4, wherein the lubricant composition contains an emulsifier, and the emulsifier has an HLB value of 7 or more.   The lubricant composition according to any one of claims 1 to 5, wherein the divalent or higher polyvalent carboxylic acid a2 contains at least 75 mass% of a C36-44 divalent carboxylic acid.   The lubricant composition according to any one of claims 1 to 3, wherein the water content is 43 mass% or more with respect to the total mass of the lubricant composition.   The lubricant composition according to claim 7, wherein the trihydric or higher polyhydric alcohol a1 and monohydric alcohol a3 have an oxyalkylene structure.   The lubricant composition according to claim 8, wherein the polyhydric alcohol a1 has three or more oxyalkylene structures, and the monohydric alcohol a3 has three or more oxyalkylene structures.   The lubricant composition contains a glycol additive, and the total content of the water and the glycol additive is 50% by mass or more based on the total mass of the lubricant composition. The lubricant composition according to claim 1.