WO2017164150A1 - Lubricant composition, method for manufacturing lubricant composition, and polyester compound - Google Patents

Abstract

The present invention addresses the problem of providing a lubricant composition demonstrating excellent solubility in a base oil as well as excellent lubricating ability. The present invention relates to a lubricant composition including a polyester compound having constituent units represented by general formula (1). The present invention furthermore relates to a polyester compound and a method for manufacturing the lubricant composition. In general formula (1), A represents a single bond, an alkylene group which may have a substituent, or a group represented by –(CR¹R²)_m-O-(CR³R⁴)_n-, B represents a single bond or a divalent linking group, Ra represents a C3 or higher substituent, Rb¹ through Rb⁴ each independently represent a hydrogen atom or a substituent, and Rb¹ and Rb³ may bond with each other and form a non-aromatic ring including B.

Description

Lubricant composition, method for producing lubricant composition, and polyester compound

The present invention relates to a lubricant composition, a method for producing the lubricant composition, and a polyester compound.

Lubricant compositions generally contain base oil (base oil) 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 properties, biodegradability, and the like.

It is known that ester oil is used not only as a base oil but also as an additive. For example, monoester obtained from reaction of aliphatic monocarboxylic acid and monool; diester obtained from reaction of aliphatic dibasic acid and monool; polyol ester obtained from reaction of polyhydric alcohol and aliphatic carboxylic acid Various esters are known; such as complex esters obtained from reaction with polyols, polybasic acids, and aliphatic monocarboxylic acids.

Patent Document 1 discloses that a polyester compound obtained by condensing dimer acid and polyol is used as a metalworking oil composition. Patent Document 2 discloses an oil-soluble polyester compound obtained by condensing a dicarboxylic acid component composed of a dicarboxylic acid having 20 or more carbon atoms and a dicarboxylic acid having less than 20 carbon atoms and a diol component as an additive for lubricating oil. It is disclosed to be used as Here, it is described that dimer acid is used as a dicarboxylic acid having 20 or more carbon atoms, and 1,2-butanediol is used as a diol component.

Further, Patent Documents 3 to 5 disclose polyester compounds obtained by condensing a specific dicarboxylic acid component and a polyol component, and such polyester compounds are also used for applications other than the lubricant composition. . For example, Patent Document 3 discloses a polyester compound obtained by condensing isosorbide, 1,4-cyclohexanedicarboxylic acid, and an aliphatic diol such as 1,2-hexanediol. Patent Document 4 discloses a polyester compound obtained by condensing terephthalic acid with 1,2-butanediol and the like. Patent Document 5 discloses a polyester compound obtained by condensing terephthalic acid, dimer acid, and 1.2-dodecanediol. In Examples of Patent Document 5, 90% terephthalic acid and 10% dimer acid are used in combination as dicarboxylic acid components.

Japanese Patent No. 3909894 JP-A-8-277323 International Publication No. 2012/123267 JP 2001-311042 A JP 2002-69162 A

However, when a polyester compound as disclosed in Patent Documents 1 to 5 is added to the lubricant composition, it has become clear from examinations by the present inventors that the solubility in the base oil may not be sufficient. It was.
In recent years, with the diversification and sophistication of the industrial field, higher lubrication performance has been required for lubricant compositions. For this reason, development of the additive of the lubricant composition which can exhibit the more excellent lubrication performance is also calculated | required.

Therefore, in order to solve such problems of the prior art, the present inventors have studied for the purpose of providing a lubricant composition that is excellent in solubility in base oil and that exhibits excellent lubricating performance. Proceeded. Furthermore, the present inventors have also studied for the purpose of providing a polyester compound that can be an additive of such a lubricant composition.

As a result of intensive studies to solve the above problems, the present inventors have found that the lubricating performance of the lubricant composition can be improved by adding a polyester compound having a specific structure. Furthermore, the present inventors have found that a polyester compound having a specific structure has excellent base oil solubility, and have completed the present invention.
Specifically, the present invention has the following configuration.

[1] A lubricant composition comprising a polyester compound having a structural unit represented by the following general formula (1);

In general formula (1), A represents a single bond, an alkylene group which may have a substituent, or a group represented by — (CR ¹ R ² ) _m —O— (CR ³ R ⁴ ) _n —. Wherein R ¹ to R ⁴ each independently represents a hydrogen atom or a substituent, and m and n each independently represents an integer of 0 or more;
B represents a single bond or a divalent linking group;
Ra represents a substituent having 3 or more carbon atoms;
Rb ¹ to Rb ⁴ each independently represents a hydrogen atom or a substituent, and Rb ¹ and Rb ³ may be bonded to each other to form a non-aromatic ring containing B.
[2] The lubricant composition according to [1], wherein Rb ¹ to Rb ⁴ each independently represents a hydrogen atom, an alkyl group that may have a substituent, or an alkenyl group that may have a substituent.
[3] The lubricant composition according to [1] or [2], wherein A is a single bond.
[4] The lubricant composition according to any one of [1] to [3], wherein the total number of carbon atoms of B and Rb ¹ to Rb ⁴ is 8 or more.
[5] The lubricant composition according to any one of [1] to [4], wherein the total number of carbon atoms of B and Rb ¹ to Rb ⁴ is 14 or more.
[6] The lubricant composition according to any one of [1] to [5], wherein Ra is an alkyl group having 3 or more carbon atoms which may have a substituent.
[7] The lubricant composition according to any one of [1] to [6], wherein Ra is an alkyl group having 6 or more carbon atoms which may have a substituent.
[8] The lubricant composition according to any one of [1] to [7], wherein Ra is an alkoxyalkyl group having 6 or more carbon atoms which may have a substituent.
[9] A method for producing a lubricant composition comprising a step of synthesizing a polyester having a weight average molecular weight of 3000 or more from a compound represented by the following general formula (11) and a dicarboxylic acid represented by the following general formula (12);

In general formula (11), A represents a single bond, an alkylene group which may have a substituent, or a group represented by — (CR ¹ R ² ) _m —O— (CR ³ R ⁴ ) _n —. Wherein R ¹ to R ⁴ each independently represents a hydrogen atom or a substituent, m and n each independently represents an integer of 0 or more; Ra represents a substituent having 3 or more carbon atoms;
In the general formula (12), B represents a single bond or a divalent linking group, Rb ¹ to Rb ⁴ each independently represents a hydrogen atom or a substituent, and at least one of Rb ¹ to Rb ⁴ and B are mutually They may combine to form a ring.
[10] A polyester compound containing a structural unit represented by the following general formula (21), wherein the content of the structural unit in the polyester compound is 20 mol% or more, and the weight average molecular weight is 3000 or more;

In General Formula (21), D represents a single bond or an alkylene group which may have a substituent;
Rd and Rd ′ each independently represents a hydrogen atom, an optionally substituted alkyl group or an optionally substituted alkenyl group, and at least one of Rd and Rd ′ is a hydrogen atom;
One of Rc and Rc ′ is a hydrogen atom, and the other of Rc and Rc ′ is an alkyl group having 7 or more carbon atoms which may have a substituent.

The polyester compound having a specific structure added to the lubricant composition of the present invention has excellent base oil solubility. A lubricant composition containing such a polyester compound can exhibit good lubricating performance.

FIG. 1 is a ¹ H-NMR (Nuclear Magnetic Resonance) chart of the polyester compound (P-1). FIG. 2 is a ¹ H-NMR chart of the polyester compound (P-4).

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.

(Polyester compound)
The present invention relates to a lubricant composition comprising a polyester compound having a structural unit represented by the following general formula (1).

In general formula (1), A represents a single bond, an alkylene group which may have a substituent, or a group represented by — (CR ¹ R ² ) _m —O— (CR ³ R ⁴ ) _n —. To express. R ¹ to R ⁴ each independently represents a hydrogen atom or a substituent, and m and n each independently represents an integer of 0 or more. B represents a single bond or a divalent linking group. Ra represents a substituent having 3 or more carbon atoms. Rb ¹ to Rb ⁴ each independently represents a hydrogen atom or a substituent, and Rb ¹ and Rb ³ may be bonded to each other to form a non-aromatic ring containing B.

Since the lubricant composition of the present invention contains a polyester compound having the above structure, it has a low coefficient of friction. That is, the lubricant composition of the present invention can exhibit excellent lubricating performance. Moreover, the lubricant composition of the present invention is preferably used even under severe conditions such as high temperature and / or high pressure.
The polyester compound has a specific branched structure, and it is considered that higher lubrication performance is exhibited by promoting oil film formation by the interaction between the hydrophobic group forming the branched structure and the base oil. It is done.

Furthermore, the polyester compound having the above structure is excellent in solubility in a base oil. Since the said polyester compound has a specific branched structure, it is thought that the solubility to a base oil increases.
In recent years, use of a low-viscosity base oil as a base oil has been studied from the viewpoint of fuel economy and energy saving. The polyester compound having the above structure not only has excellent solubility in general-purpose base oils, but also has excellent solubility in low-viscosity base oils. For this reason, the polyester compound which has the said structure can be used regardless of the viscosity and kind of base oil.

In the general formula (1), A represents a single bond, an alkylene group which may have a substituent, or a group represented by — (CR ¹ R ² ) _m —O— (CR ³ R ⁴ ) _n —. Represents. However, in — (CR ¹ R ² ) _m —O— (CR ³ R ⁴ ) _n —, R ¹ to R ⁴ each independently represents a hydrogen atom or a substituent, and m and n each independently represents 0 or more. Represents an integer. Is a group represented by, - - A is _{^{- (CR 1 R 2) m}} -O- (CR 3 R 4) n (CR 1 R 2) m -O- (CR 3 R 4) n - in R ¹ to R ⁴ are preferably hydrogen atoms, and m and n are each independently preferably an integer of 0 or more and 4 or less. A may be [— (CR ¹ R ² ) _m —O— (CR ³ R ⁴ ) _n —] _p . In this case, p represents an integer of 1 or more. When p is 2 or more, the plurality of m may be different from each other, and the plurality of n may be different from each other. The plurality of R ¹ to R ⁴ may be different from each other. From the viewpoint of base oil solubility, the molecular weight of [— (CR ¹ R ² ) _m —O— (CR ³ R ⁴ ) _n —] _p is preferably less than 1000.

Among them, A is preferably a single bond or an alkylene group which may have a substituent, and more preferably a single bond. When A is an alkylene group that may have a substituent, the alkylene group preferably has 1 to 10 carbon atoms, and more preferably 1 to 4 carbon atoms. The alkylene group is preferably an unsubstituted alkylene group. Preferred alkylene groups include methylene group, ethylene group, n-propylene group, n-butylene group and the like.

In the general formula (1), Ra represents a substituent having 3 or more carbon atoms. Ra preferably has 4 or more carbon atoms, more preferably 5 or more, still more preferably 6 or more, still more preferably 7 or more, and particularly preferably 8 or more.

The substituent represented by Ra includes an alkyl group that may have a substituent, a cycloalkyl group that may have a substituent, an alkenyl group that may have a substituent, and a substituent. Examples thereof may include an aryl group that may be substituted, a heteroaryl group that may have a substituent, and the like. The alkyl group, cycloalkyl group, alkenyl group, aryl group and heteroaryl group described above may have a substituent, and the carbon atom of the alkylene group, cycloalkylene group or alkenyl group may be substituted with a hetero atom. . In this case, a structure in which heteroatoms are connected in the main chain is not taken. In addition, as a hetero atom, O atom, S atom, N atom, Si atom, etc. are mentioned.
When the substituent represented by Ra further has a substituent, examples of such a substituent include an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group, a heteroaryl group, an alkoxy group, an alkoxycarbonyl group, Examples include a halogen atom, a halogenated alkyl group, an alkylcarbonyl group, a cyano group, a sulfoxide group, a sulfonyl group, and an amide group. For example, when the alkyl group which may have a substituent has an alkoxy group as a substituent, the substituent represented by Ra can be an alkoxyalkyl group.

Of these, Ra is preferably an alkyl group which may have a substituent, and the alkyl group may be linear or branched. Ra is more preferably an alkyl group having 3 or more carbon atoms which may have a substituent, more preferably an alkyl group having 6 or more carbon atoms which may have a substituent. More preferably, it is an alkyl group having 8 or more carbon atoms which may have a group. In addition, the said carbon number is carbon number including the carbon number of a substituent.

When Ra is an alkyl group having a substituent, examples of the substituent that the alkyl group has include the substituents described above. Among them, the substituent that the alkyl group has is preferably an alkoxy group. When Ra is an alkyl group having an alkoxy group as a substituent, the number of carbon atoms of such an alkoxyalkyl group is preferably 3 or more, more preferably 6 or more, and preferably 8 or more. Further preferred. The alkoxyalkyl group may further have a substituent, and the number of carbon atoms of the alkoxyalkyl group that may have a substituent is preferably in the above range.

In the general formula (1), B represents a single bond or a divalent linking group. B preferably represents a divalent linking group, and examples of the divalent linking group include an aliphatic hydrocarbon linking group. Especially, it is preferable that a bivalent coupling group is an alkylene group or a cycloalkylene group, and it is more preferable that it is an alkylene group. The aliphatic hydrocarbon linking group may be an unsaturated hydrocarbon linking group. In this case, the ratio of unsaturated carbon / saturated carbon is preferably 0.5 or less, and is 0.3 or less. It is more preferable.

The carbon number of B is preferably 6 or more, more preferably 8 or more, further preferably 10 or more, still more preferably 14 or more, and particularly preferably 20 or more. 30 or more is more preferable, and 34 or more is most preferable. Moreover, it is preferable that the carbon number of B is 70 or less. In addition, when B is a cycloalkylene group, the number of carbon atoms is preferably 6 to 10, and examples of the cycloalkylene group include a cyclohexylene group.
B may have a substituent, and the carbon number of B here refers to the number including the carbon number of the substituent.

When B has a substituent, examples of the substituent include an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group, a heteroaryl group, an alkoxy group, an alkoxycarbonyl group, a halogen atom, a halogenated alkyl group, and an alkylcarbonyl group. , Cyano group, sulfoxide group, sulfonyl group, amide group and the like. In B, the carbon atom of the linking group may be substituted with a hetero atom. In this case, examples of the hetero atom include an O atom, an S atom, and an N atom.
Among these, when B has a substituent, the substituent is preferably an alkyl group or an alkenyl group. Such an alkyl group or alkenyl group may be linear or branched. Examples of the alkyl group include alkyl groups having 1 to 70 carbon atoms, and examples of the alkenyl group include alkenyl groups having 2 to 35 carbon atoms.

In the general formula (1), Rb ¹ to Rb ⁴ each independently represents a hydrogen atom or a substituent. When Rb ¹ to Rb ⁴ are a substituent, examples of the substituent include an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group, a heteroaryl group, an alkoxy group, an alkoxycarbonyl group, a halogen atom, and a halogenated alkyl group. , Alkylcarbonyl group, cyano group, sulfoxide group, sulfonyl group, amide group and the like. Among these, the substituent is preferably an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group, a heteroaryl group, or an alkoxy group, and more preferably an alkyl group or an alkenyl group. The substituent may further have a substituent, and in this case, the above-described substituents can be similarly listed.

Among them, it is preferable that Rb ¹ to Rb ⁴ each independently represent a hydrogen atom, an alkyl group that may have a substituent, or an alkenyl group that may have a substituent. The number of carbon atoms of the alkyl group which may have a substituent is preferably 1-30, more preferably 1-20, and still more preferably 1-15. In addition, the said carbon number means the number including carbon number of a substituent. The number of carbon atoms of the alkenyl group that may have a substituent is preferably 2 to 30, more preferably 2 to 20, and still more preferably 2 to 15.

At least one of Rb ¹ to Rb ⁴ is preferably a hydrogen atom, and more preferably three of Rb ¹ to Rb ⁴ are hydrogen atoms. When three of Rb ¹ to Rb ⁴ are hydrogen atoms, the remaining ^one of Rb ¹ to Rb ⁴ is preferably an alkyl group which may have a substituent, and is an unsubstituted alkyl group It is more preferable. Note that all of Rb ¹ to Rb ⁴ may be hydrogen atoms.

Rb ¹ and Rb ³ may combine with each other to form a non-aromatic ring containing B. The number of ring members of the non-aromatic ring is preferably 5 to 20, and more preferably 5 to 10. When Rb ¹ and Rb ³ are bonded to each other to form a non-aromatic ring containing B, the non-aromatic ring is preferably cyclohexane.

The total number of carbon atoms of B and Rb ¹ to Rb ⁴ is preferably 8 or more, more preferably 10 or more, further preferably 14 or more, still more preferably 20 or more, It is particularly preferably 30 or more, and most preferably 34 or more. The total number of carbon atoms of B and Rb ¹ to Rb ⁴ is preferably 72 or less.

In general formula (1), the group represented by the following structure is preferably a residue of a divalent or higher polyvalent carboxylic acid. Here, the residue of the polyvalent carboxylic acid refers to a group constituting a part obtained by removing the carboxyl group from the polyvalent carboxylic acid. The group represented by the following structure is preferably a dimer acid residue, a trimer acid residue or an erucic acid dimer residue.

The polyester compound preferably has a structure represented by the following general formula (21).

In general formula (21), D represents a single bond or an alkylene group which may have a substituent. Rd and Rd ′ each independently represent a hydrogen atom, an alkyl group that may have a substituent, or an alkenyl group that may have a substituent, and at least one of Rd and Rd ′ is a hydrogen atom. One of Rc and Rc ′ is a hydrogen atom, and the other of Rc and Rc ′ is an alkyl group having 7 or more carbon atoms which may have a substituent.

D in the general formula (21) is preferably an alkylene group which may have a substituent. The number of carbon atoms of D is preferably 6 or more, more preferably 8 or more, further preferably 10 or more, still more preferably 14 or more, and particularly preferably 20 or more. 30 or more is more preferable, and 34 or more is most preferable. Moreover, it is preferable that the carbon number of D is 70 or less.
In addition, as a substituent which an alkylene group can have, the thing similar to the substituent which B in General formula (1) can have can be enumerated.

In General Formula (21), Rd and Rd ′ each independently represent a hydrogen atom, an alkyl group that may have a substituent, or an alkenyl group that may have a substituent, and at least one of Rd and Rd ′. Is a hydrogen atom. Both Rd and Rd ′ may be a hydrogen atom.
When any of Rd and Rd ′ is an optionally substituted alkyl group or an optionally substituted alkenyl group, these groups have 1 to 30 carbon atoms. It is preferably 1 to 20, more preferably 1 to 15.

The total number of carbon atoms of D, Rd, and Rd ′ is preferably 8 or more, more preferably 9 or more, further preferably 10 or more, and still more preferably 14 or more, 20 It is particularly preferably at least 30, more preferably at least 30, and most preferably at least 34. The total number of carbon atoms of D, Rd, and Rd 'is preferably 72 or less.

In General Formula (21), one of Rc and Rc ′ is a hydrogen atom, and the other of Rc and Rc ′ is an alkyl group having 7 or more carbon atoms which may have a substituent. The alkyl group having 7 or more carbon atoms which one of Rc and Rc ′ has may have a substituent, and the carbon atom of the alkyl group may be substituted with a heteroatom. In this case, a structure in which heteroatoms are connected in the main chain is not taken. In addition, as a hetero atom, O atom, S atom, N atom, Si atom, etc. are mentioned.
When the alkyl group having 7 or more carbon atoms has a substituent, examples of such a substituent include an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group, a heteroaryl group, an alkoxy group, an alkoxycarbonyl group, a halogen Examples thereof include an atom, a halogenated alkyl group, an alkylcarbonyl group, a cyano group, a sulfoxide group, a sulfonyl group, and an amide group. For example, when an alkyl group having 7 or more carbon atoms has an alkoxy group as a substituent, one of Rc and Rc ′ becomes an alkoxyalkyl group. It is also preferable that either one of Rc and Rc ′ is an alkoxyalkyl group having 7 or more carbon atoms.

Hereinafter, specific examples of the structural unit represented by the general formula (1) will be listed, but the present invention is not limited to the following structural units. In the following specific examples, the structural unit represented by the general formula (1) is divided into partial structures of A and B as shown in the following structural formula, and each partial structure is listed. That is, as a specific example of the structural unit represented by the general formula (1), a structure in which a partial structure of A below and a partial structure of B are combined is given.

In the structural formula of the specific example of the partial structure A, any one of * represents a connecting portion with the partial structure B.

In the structural formula of the specific example of the partial structure B, any one of * represents a connecting portion with the partial structure A.

The polyester compound contained in the lubricant composition of the present invention may contain an arbitrary partial structure in addition to the above structural unit. The arbitrary partial structure is not particularly limited, but for example, arbitrary partial structures listed below can be listed as preferred examples.

In the structural formula of the specific example of the arbitrary partial structure, * represents a connecting portion with the partial structure of A or the partial structure of B described above. In the above structural formula, X may be a connecting portion with a partial structure of A or a partial structure of B, or may be a hydrogen atom. In addition, what does not have X in the said structural formula connects with the terminal of a polyester compound. That is, C-5 to C-7 having the above structure can exert the terminal blocking function of the polyester compound. In other words, C-5 to C-7 having the above structure exerts a molecular weight adjusting function of the polyester compound.

The proportion of the arbitrary partial structure in the polyester compound is preferably 20 mol% or less, more preferably 15 mol% or less, and even more preferably 10 mol% or less.

The polyester compound contained in the lubricant composition of the present invention is preferably any one of the following compounds (P-1) to (P-37).

Of these, polyester compounds using A-3 and A-5 as the partial structure of A, and polyester compounds using B-1 and B-2 as the partial structure of A are preferable, and compounds P-1, P- 4 to P-6, P-8 to P-10, and P-14 are preferably used.

The content of the structural unit represented by the above general formula in the polyester compound is preferably 20 mol% or more, more preferably 30 mol% or more, and further preferably 40 mol% or more. , 50 mol% or more is particularly preferable. By making the content rate of the structural unit represented by the general formula described above within the above range, the lubricating performance can be more effectively enhanced, and further the base oil solubility can be enhanced.

The content rate of the structural unit represented by the general formula described above can be calculated from the amount added during the synthesis of the polyester compound.
In addition, when it cannot calculate from the addition amount at the time of a polyester compound synthesis | combination, the content rate of a structural unit can also be determined by employ | adopting the method of following (1) and (2) from the synthesized polyester compound.
(1) By carbon NMR, carbon to which a group corresponding to Ra in the general formula (1) is bonded, carbon to which a group corresponding to Rb ¹ or Rb ² is bonded, and an ester group present between these carbons are represented. Detect peaks. Then, the ratio of the ratio of the carbon to which the group corresponding to Ra is bonded and the ratio of the carbon to which the group corresponding to Rb ¹ or Rb ² is bonded to the peak representing the ester group is calculated.
(2) The polymer is appropriately decomposed by EI-MS (Electron Impact-Mass Spectrometry), and the abundance ratio of MS fragments of about 2 units is measured. Calculate the percentage of MS fragments.
For example, when confirming that the content of the structural unit represented by the above-described general formula is 20% or more, it is confirmed by calculating a ratio of 20% or more in both (1) and (2) above. it can.

The weight average molecular weight of the polyester compound is preferably 1000 or more, more preferably 2000 or more, and further preferably 3000 or more. Moreover, it is preferable that the weight average molecular weight of a polyester compound is 150,000 or less. By setting the weight average molecular weight of the polyester compound within the above range, it is possible to improve oil film formation due to the interaction between the polyester compound and the base oil, and to exhibit higher lubricating performance. Moreover, base oil solubility can be improved more effectively by making the weight average molecular weight of a polyester compound into the said range.

The weight average molecular weight of the polyester compound was determined by gel permeation chromatography (GPC, manufactured by Tosoh Corporation, trade name: HLC-8020 / four columns: manufactured by Tosoh Corporation, trade name: TSKguardcolumn SuperHZ-H, TSKgel SuperHZM-H, TSKgelｇSuperHZ4000, TSKgel SuperHZ2000). Tetrahydrofuran (THF) is used as a solvent, a calibration curve is prepared from a standard polystyrene sample, and the converted molecular weight (weight average molecular weight = Mw) of the sample is determined.

The acid value of the polyester compound is preferably 100 mgKOH / g or less, and more preferably 60 mgKOH / g or less. The acid value of the polyester compound may be 0 mgKOH / g. By setting the acid value of the polyester compound within the above range, it is possible to suppress the occurrence of rust on the metal surface even when the sliding surface to which the lubricant composition is applied is made of metal. .

The present invention also relates to the above-described polyester compound. More specifically, the present invention is a polyester compound containing the structural unit represented by the general formula described above, wherein the content of the structural unit in the polyester compound is 20 mol% or more, and the weight average molecular weight is 3000. It also relates to the above polyester compounds.

(Lubricant composition)
The present invention relates to a lubricant composition containing a polyester compound containing a structural unit represented by the above general formula. The content of the polyester compound in the lubricant composition is preferably 0.1 to 60% by mass with respect to the total mass of the lubricant composition. The content of the polyester compound may be 0.1 to 10% by mass. In the present invention, excellent lubricating performance can be exhibited even when the content of the polyester compound is small.

In addition to the polyester compound described above, a medium and / or various additives can be further added to the lubricant composition of the present invention.

(Medium)
As a medium, what is generally called base oil can be used. Base oils include mineral oils, fat compounds, polyolefin oils (eg polyalphaolefins), silicone oils, ether oils (eg perfluoropolyether oils, diphenyl ether derivatives), ester oils (eg aromatic ester oils, monovalent fatty acid esters, 1 type (s) or 2 or more types selected from divalent fatty-acid diester and a polyol ester lubricating oil) can be mentioned. Among these, the base oil is preferably at least one selected from mineral oil, polyolefin oil, and ester oil.
Moreover, as a base oil, you may use what is marketed as an engine oil use. Some commercially available engine oils contain additives, but engine oils containing additives can also be used as the base oil. Examples of commercially available engine oils include Nissan Motor's Strong Save, Extra Save, Honda Motor's Ultra Green, Ultra Next, Ultra Leo, Toyota Motor Castle, Exxon Mobil Mobile 1 (10W-30, 5W-30), etc. Is mentioned.

In the present invention, “medium” means all the media generally called “fluid liquid”. However, it is not necessary to be liquid at room temperature or the temperature used, and any form of material such as solid and gel can be used in addition to liquid. There is no restriction | limiting in particular about the medium utilized in this invention, According to a use, it can select from various liquids. Regarding the medium that can be used in the present invention, the description in paragraphs 0067 to 0096 of JP2011-89106A can be referred to.

Kinematic viscosity at 40 ° C. of the medium is preferably from 1 ~ 500mm ² / s, more preferably ^{1.5 ~ 200mm 2 / s, 2} ~ 50mm 2 / s is more preferable. In the present invention, a medium having a kinematic viscosity at 40 ° C. of 2 to 30 mm ² / s can also be used. The polyester compound described above exhibits good solubility in such a low-viscosity base oil.

The viscosity index of the medium is preferably 90 or more, more preferably 105 or more, and still more preferably 110 or more. The viscosity index of the medium is preferably 160 or less. By setting the viscosity index within the above range, viscosity characteristics, temperature characteristics, thermal stability, oxidation stability, and volatilization prevention properties are improved, and wear prevention properties are improved. The viscosity index referred to in the present invention means a viscosity index measured according to JIS K 2283-1993.

The sulfur content in the medium is preferably 0.03% by mass or less. Further, the saturation content of the medium is preferably 90% or more. The medium is preferably of API base oil classification group 2 or 3.

(Additive)
A preferred additive to the lubricant composition of the present invention is a compound containing at least one selected from zinc, molybdenum, sulfur and phosphorus as a constituent element. Such compounds have functions such as friction modifiers, antiwear agents, and antioxidants. The compound containing at least one of zinc, molybdenum, sulfur and phosphorus as a constituent element means a compound which may contain zinc, molybdenum, sulfur and phosphorus in any state. Specific examples include compounds containing zinc, molybdenum, sulfur, and phosphorus as simple substances (oxidation number 0), ions, complexes, and the like. Examples of such compounds include organic molybdenum compounds, inorganic molybdenum compounds, organic zinc compounds, (phosphite) phosphoric acid derivatives, organic sulfur compounds, and the like. Of these, organic molybdenum compounds and organic zinc compounds are preferred.

Further, only one compound containing at least one selected from zinc, molybdenum, sulfur and phosphorus as a constituent element may be added to the lubricant composition of the present invention, and two or more compounds of the lubricant of the present invention may be used. It may be added to the composition. When adding two or more compounds containing at least one selected from zinc, molybdenum, sulfur and phosphorus as a constituent element to the lubricant composition of the present invention, an organic molybdenum compound, an inorganic molybdenum compound, an organic zinc compound, It is preferable to combine two or more of (sub) phosphoric acid derivatives and organic sulfur compounds, and it is more preferable to combine organic molybdenum compounds and organic zinc compounds.

Hereinafter, preferred embodiments of the organic molybdenum compound, the inorganic molybdenum compound, the organic zinc compound, the (phosphite) phosphoric acid derivative, and the organic sulfur compound will be described.

Examples of the organic molybdenum compound used as an additive in the lubricant composition include organic molybdenum compounds containing phosphorus such as molybdenum dithiophosphate (sometimes referred to as MoDTP). As another organic molybdenum compound, an organic molybdenum compound containing sulfur such as molybdenum dithiocarbamate (sometimes referred to as MoDTC) can be given. Examples of the organic molybdenum compound containing sulfur include sulfurized oxymolybdenum-N, N-di-octyldithiocarbamate (C ₈ -Mo (DTC)), sulfurized oxymolybdenum-N, N-di-tridecyldithiocarbamate ( C ₁₆ -Mo (DTC) and the like are preferable.

Examples of other sulfur-containing organic molybdenum compounds include complexes of inorganic molybdenum compounds and sulfur-containing organic compounds. Examples of the inorganic molybdenum compound used in the organic molybdenum compound that is a complex of an inorganic molybdenum compound and a sulfur-containing organic compound include molybdenum oxides such as molybdenum dioxide and molybdenum trioxide, orthomolybdic acid, paramolybdic acid, and (poly) sulfurization. Molybdic acid such as molybdic acid, metal salts of these molybdic acids, molybdate such as ammonium salt, molybdenum disulfide, molybdenum trisulfide, molybdenum pentasulfide, molybdenum sulfide such as polysulfide molybdenum, molybdenum sulfide, molybdenum sulfide Examples thereof include metal salts or amine salts, and molybdenum halides such as molybdenum chloride. Examples of the sulfur-containing organic compound used in the organic molybdenum compound that is a complex of an inorganic molybdenum compound and a sulfur-containing organic compound include alkyl (thio) xanthate, thiadiazole, mercaptothiadiazole, thiocarbonate, and tetrahydrocarbyl thiuram disulfide. Bis (di (thio) hydrocarbyl dithiophosphonate) disulfide, organic (poly) sulfide, sulfurized ester and the like.
Examples of other organic molybdenum compounds containing sulfur include complexes of sulfur-containing molybdenum compounds such as molybdenum sulfide and sulfurized molybdenum acid with alkenyl succinimides.

As the organic molybdenum compound, an organic molybdenum compound that does not contain phosphorus or sulfur as a constituent element can be used. Specific examples of organic molybdenum compounds that do not contain phosphorus or sulfur as constituent elements include molybdenum-amine complexes, molybdenum-succinimide complexes, molybdenum salts of organic acids, and molybdenum salts of alcohols. Amine complexes, molybdenum salts of organic acids and molybdenum salts of alcohols are preferred.

The inorganic molybdenum compound used as an additive in the lubricant composition is the same as that exemplified as the inorganic molybdenum compound used for the organic molybdenum compound which is a complex of the inorganic molybdenum compound and the sulfur-containing organic compound.

The organozinc compound used as an additive in the lubricant composition is preferably zinc dithiophosphate (ZDTP) or zinc diphosphate (ZDP) represented by the following formula.

In the above formula, Q ¹ , Q ² , Q ³ and Q ⁴ may be the same or different, and are each independently isopropyl, butyl, isobutyl, pentyl, isopentyl, neopentyl, hexyl, heptyl. Represents an alkyl group having 8 to 20 carbon atoms such as a group, octyl group, 2-ethylhexyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, isotridecyl group, misty group, palmityl group and stearyl group.

Specific examples of zinc dithiophosphate (ZDTP) represented by the above formula include zinc n-butyl-n-pentyldithiophosphate (C ₄ / C ₅ ZnDTP) and zinc di-2-ethylhexyldithiophosphate (C ₈ ZnDTP). Alternatively, zinc isopropyl-1-ethylbutyldithiophosphate (C ₃ / C ₆ ZnDTP) is preferable.

When an organic molybdenum compound is used in the lubricant composition of the present invention, the organic molybdenum compound is preferably contained in an amount of 10 to 1500 mg / L as a molybdenum content with respect to the total mass of the lubricant composition. More preferably, it is contained in an amount of 1000 mg / L, more preferably 100 to 800 mg / L.
When an organic zinc compound is used, it is preferable that the zinc content of the organic zinc compound is 50 to 10,000 mg / L, and 100 to 5000 mg / L is included with respect to the total mass of the lubricant composition. Is more preferable, and 200 to 1500 mg / L is more preferable.
By making content of organometallic compounds, such as an organomolybdenum compound and an organozinc compound, in a lubricant composition in the said range, stability of a lubricant composition can be improved.

Examples of the (sub) phosphoric acid derivative include, in addition to the above-mentioned zinc dithiophosphate (ZDTP) and zinc diphosphate (ZDP), phosphites, phosphate esters, tricresyl phosphate and other aromatic phosphate esters, phosphorus Aliphatic phosphate esters such as trialkyl acids can be exemplified as preferred examples. Of these, aromatic phosphate esters such as tricresyl phosphate and aliphatic phosphate esters such as trialkyl phosphate are more preferable.

As the organic sulfur compound, polysulfides are preferable, and dialkyl polysulfide is more preferable.

As the additive, in addition to the above compound, for example, a viscosity index improver (preferably polyalkyl (meth) acrylate, alkyl (meth) acrylate- (meth) acrylate copolymer having a polar group, butadiene, olefin or alkyl) Styrene polymers and copolymers), antioxidants (preferably hindered phenol compounds, sulfurized alkylphenol compounds, aromatic amine compounds, low sulfur peroxide decomposers, oil-soluble copper compounds), detergents (sulfates, phenates, carboxy) Alkali metal salts or alkaline earth metal salts of phosphates, phosphates and salicylates, (boric acid modified) succinimides, succinic acid esters), dispersants (preferably phenates, sulfonates, sulfurized phenates, salicylates, naphthenates, stearates, carbamates Salts, thiocarbamates, phosphorus derivatives, succinic acid derivatives (eg long chain substituted alkenyl succinic acid derivatives, succinimide derivatives, hydrocarbyl substituted succinic acid compounds, succinic acid esters, succinic acid ester amides), Mannich bases, pour point depression Agents (preferably polymethacrylates, polyacrylates, polyarylamides, condensation products of haloparaffin waxes and aromatic compounds, vinyl carboxylate polymers and dialkyl fumarate, terpolymers of fatty acid vinyl esters and allyl vinyl ethers), corrosion inhibitors ( Preferably thiadiazoles), seal compatibilizers (preferably organic phosphates, aromatic esters, aromatic hydrocarbons, esters (eg butylbenzyl phthalate) and polybutenyl succinic anhydride), antifoaming agents (preferably Ku is polydimethyl silicones), rust inhibitors, friction modifiers, mention may be made of anti-wear agents, and one or more selected from thickener.
By adding such an additive, a lubricant composition capable of exhibiting functions such as wear suppression can be obtained. Regarding the additives that can be used in the present invention, the description in paragraphs 0098 to 0165 of JP2011-89106A can be referred to.

(Properties of lubricant composition)
The lubricant composition of the present invention preferably has a kinematic viscosity at 40 ° C. of 500 mm ² / s or less, more preferably 200 mm ² / s or less, and even more preferably 100 mm ² / s or less. 50 mm ² / s or less is particularly preferable, and 5 to 50 mm ² / s is most preferable. In this specification, the kinematic viscosity at 40 ° C. of the lubricant composition is specifically a value measured in a constant temperature water bath at 40.0 ° C. using an Ubbelohde viscometer.

(Grease composition)
The above-described polyester compound may be mixed with grease to form a grease composition. In such an embodiment, a thickener or the like can be appropriately added as necessary in order to ensure practical performance when adapted to the application of grease. When adding a thickener, the thickener is preferably contained in an amount of 10 to 50% by mass based on the total mass of the grease composition. Hereinafter, additives that can be added when preparing the grease composition will be described.

Thickeners that can be added include soap-type thickeners such as metal soaps and composite metal soaps, benton, silica gel, and urea-type thickeners (urea compounds, urea / urethane compounds, urethane compounds, etc.). Any thickener such as a thickener can be used. Among these, a soap-based thickener and a urea-based thickener are preferably used because they are less likely to damage the resin member.

Examples of the soap-based thickener include sodium soap, calcium soap, aluminum soap, lithium soap and the like. Among these, lithium soap is preferable from the viewpoint of water resistance and thermal stability. Examples of the lithium soap include lithium stearate and lithium-12-hydroxystearate.

Further, examples of the urea thickener include urea compounds, urea / urethane compounds, urethane compounds, and mixtures thereof.

Examples of urea compounds, urea / urethane compounds and urethane compounds include diurea compounds, triurea compounds, tetraurea compounds, polyurea compounds (excluding diurea compounds, triurea compounds and tetraurea compounds), urea / urethane compounds, diurethane compounds or mixtures thereof. Etc. Preferably, a diurea compound, a urea / urethane compound, a diurethane compound or a mixture thereof is used.

The grease composition can also contain a solid lubricant as an additive. Examples of solid lubricants include polytetrafluoroethylene, boron nitride, fullerene, graphite, fluorinated graphite, melamine cyanurate, molybdenum disulfide, Mo (molybdenum) -dithiocarbamate, antimony sulfide, and alkali (earth) metal boric acid. Examples include salts.

Also, the grease composition can contain a wax as an additive. Examples of the wax include natural waxes, mineral oils and various synthetic waxes, and specifically include montan wax, carnauba wax, amide compounds of higher fatty acids, paraffin wax, microcrystalline wax, polyethylene wax, polyolefin wax. And ester wax.

In addition, benzotriazole, benzimidazole, thiadiazole and the like are known as metal deactivators, and these can be added.

A thickener can be added to the grease composition. Examples of the thickener include polymethacrylate, polyisobutylene, polystyrene and the like. Poly (meth) acrylate is also known to prevent cold abnormal noise in cold regions.

(Method for producing lubricant composition)
Examples of the method for producing the lubricant composition of the present invention include the following methods (1) and (2).
(1) A method for producing a lubricant composition comprising a step of mixing a compound represented by the following general formula (11) and a polyvalent carboxylic acid to synthesize a polyester compound.
(2) A method for producing a lubricant composition comprising a step of mixing a polyhydric alcohol compound and a polyvalent carboxylic acid to synthesize a polyester compound.

As a method for producing the lubricant composition, any of the above methods (1) and (2) may be adopted. However, when it is desired to produce a lubricant composition containing a polyester compound having a predetermined weight average molecular weight. The method (1) is preferably adopted.

The manufacturing method of the lubricant composition of (1) synthesizes a polyester compound having a weight average molecular weight of 3000 or more from a compound represented by the following general formula (11) and a dicarboxylic acid represented by the following general formula (12). It is preferable that it is a manufacturing method of the lubricant composition containing a process.

In general formula (11), A represents a single bond, an alkylene group which may have a substituent, or a group represented by — (CR ¹ R ² ) _m —O— (CR ³ R ⁴ ) _n —. To express. R ¹ to R ⁴ each independently represents a hydrogen atom or a substituent, and m and n each independently represents an integer of 0 or more. Ra represents a substituent having 3 or more carbon atoms.
In the general formula (12), B represents a single bond or a divalent linking group, Rb ¹ to Rb ⁴ each independently represents a hydrogen atom or a substituent, and at least one of Rb ¹ to Rb ⁴ and B are mutually They may combine to form a ring.

In General Formula (11), A represents a single bond, an alkylene group which may have a substituent, or a group represented by — (CR ¹ R ² ) _m —O— (CR ³ R ⁴ ) _n —. To express. The preferable range of A in General formula (11) is the same as the preferable range of A in General formula (1).
In the general formula (11), Ra represents a substituent having 3 or more carbon atoms. The preferable range of Ra in the general formula (11) is the same as the preferable range of Ra in the general formula (1).

Specific examples of the compound represented by the general formula (11) include at least one selected from an epoxy compound and an oxetane compound that can be the partial structure of A described above.

In the general formula (12), B represents a single bond or a divalent linking group. The preferable range of B in the general formula (12) is the same as the preferable range of B in the general formula (1).
In the general formula (12), Rb ¹ to Rb ⁴ each independently represents a hydrogen atom or a substituent, and at least one of Rb ¹ to Rb ⁴ and B may be bonded to each other to form a ring. The preferred range of Rb ¹ ~ Rb ⁴ in the general formula (12) are respectively the same as the preferred ranges of Rb ¹ ~ Rb ⁴ in the general formula (1).

Specific examples of the compound represented by the general formula (12) include dicarboxylic acids that can be the partial structure of B described above. For example, 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), unsaturated having 22 carbon atoms Dimers of carboxylic acids (eg erucic acid dimer), malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, 1,4-cyclohexanedicarboxylic acid, maleic acid, fumaric acid , Itaconic acid, citraconic acid, dodecenyl succinic acid, octadecenyl succinic acid and the like.

Of these, dimer acid, hydrogenated dimer acid, trimer acid (trimer of unsaturated carboxylic acid having 18 carbon atoms) and erucic acid dimer are preferably used. Here, the dimer acid is an aliphatic or alicyclic dicarboxylic acid produced by dimerization of an unsaturated fatty acid (usually 18 carbon atoms) by polymerization or Diels-Alder reaction (in addition to most dimers, Many of them contain trimers, monomers and the like of several mol%), and among them, those whose main components are trimers are defined as trimer acids.
As specific examples of dimer acid or trimer acid, Tsunodim (registered trademark) 205, 216, 228, and 395 manufactured by Tsukino Food Industry Co., Ltd. are listed as examples of dimer acid. Tsunodim 345 and the like are listed as examples of trimer acid. It is done. As the dimer acid or trimer acid, products of Cognis, Unikema, and Croda may also be used. An example of a dimer of an unsaturated carboxylic acid having 22 carbon atoms is Cropa's Prepol 1004.

In addition, the polyvalent carboxylic acid represented by the general formula (12) may be substituted for a carboxylic acid derivative. Examples of carboxylic acid derivatives include acid anhydrides and acid halides.

In the step of synthesizing the polyester compound of the method for producing the lubricant composition of (1), the compound represented by the general formula (11) and the polyvalent carboxylic acid are converted to 1 / 0.7 to 0.7 / 1. It is preferable to mix at a molar ratio. In the step of synthesizing the polyester compound, monool, polyol, monocarboxylic acid or the like may be added.

The step of synthesizing the polyester compound is preferably performed in the presence of a catalyst or without a catalyst. Moreover, when synthesizing the polyester compound, it is desirable to heat or to make an appropriate amount of a solvent azeotropic with water exist. The solvent is preferably a hydrocarbon solvent having a boiling point of 100 to 200 ° C., more preferably a hydrocarbon solvent of 100 to 170 ° C., and most preferably a hydrocarbon solvent of 110 to 160 ° C. Examples of these solvents include toluene, xylene, mesitylene and the like.

Although the reaction is accelerated by using a catalyst, it is desirable not to use it because the post-treatment of removing the catalyst is complicated and causes the coloring of the polyester compound. However, when used, normal conditions and procedures are used with normal catalysts. Regarding this, reference can be made to the references in JP-T 2001-501989, JP-A 2001-500509, JP-A 2001-507334, and JP-A 2002-509563.

In the step of synthesizing the polyester compound, the raw materials are mixed and then reacted at a liquid temperature of 120 to 250 ° C., preferably 130 to 230 ° C. As a result, a solvent containing water is azeotroped, cooled at a cooling site such as Dean Stark, and becomes a liquid to separate water and the solvent. This water may be removed.

The reaction time is preferably 1 to 24 hours, more preferably 3 to 18 hours, still more preferably 5 to 18 hours, and most preferably 6 to 15 hours.

The method for producing a lubricant composition of (2) includes a step of synthesizing a polyester compound by mixing a polyhydric alcohol compound and a polyvalent carboxylic acid. The manufacturing method of the lubricant composition of (2) synthesizes a polyester compound having a weight average molecular weight of 1000 or more from a diol represented by the following general formula (13) and a dicarboxylic acid represented by the following general formula (12). It is preferable that it is a manufacturing method of the lubricant composition containing a process.

In general formula (13), A represents a single bond, an alkylene group which may have a substituent, or a group represented by — (CR ¹ R ² ) _m —O— (CR ³ R ⁴ ) _n —. To express. R ¹ to R ⁴ each independently represents a hydrogen atom or a substituent, and m and n each independently represents an integer of 0 or more. Ra represents a substituent having 3 or more carbon atoms.
In the general formula (12), B represents a single bond or a divalent linking group, Rb ¹ to Rb ⁴ each independently represents a hydrogen atom or a substituent, and at least one of Rb ¹ to Rb ⁴ and B are mutually They may combine to form a ring.

The preferable range of A in the general formula (13) is the same as the preferable range of A in the general formula (1). The preferable range of Ra in the general formula (13) is the same as the preferable range of Ra in the general formula (1).

Examples of the diol represented by the general formula (13) include diols that can be the partial structure of A described above. For example, 1,2-hexanediol, 1,2-decanediol, 1,2-tetradecanediol, 3- (2-ethylhexyloxy) -1,2-propanediol, 1,2-octanediol, 2-propyl- Examples thereof include 1, -4-hexanediol.

The conditions for the step of synthesizing the polyester compound in the method for producing the lubricant composition of (2) are the same as the conditions for the step of synthesizing the polyester compound in the method for producing the lubricant composition of (1). Can be adopted as appropriate.

(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. Specific examples of the sliding surface material include structural structural carbon steel, nickel chrome steel material, nickel chrome molybdenum steel material, chrome steel material, chrome molybdenum steel material, aluminum chrome molybdenum steel material, stainless steel, Examples include multi-aging 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.
For the material of the sliding surface, reference can be made to the descriptions in paragraphs 0168 to 0175 of JP2011-89106A.

The lubricant composition of the present invention can be used for various applications. For example, grease lubricant, mold release agent, internal combustion engine oil, internal combustion engine oil, metal working (cutting) oil, bearing oil, combustion engine fuel, vehicle engine oil, gear oil, automotive operation Oil, Marine / Aircraft Lubricant, Machine Oil, Turbine Oil, Bearing Oil, Hydraulic Oil, Compressor / Vacuum Pump Oil, Refrigerator Oil, Metalworking Lubricant, Magnetic Recording Medium Lubricant, Micromachine Lubricant It can be used as a lubricant for artificial bone, shock absorber oil or rolling oil. It is also used for air conditioners and refrigerators with reciprocating and rotary hermetic compressors, automotive air conditioners and dehumidifiers, freezers, refrigerated warehouses, vending machines, showcases, chemical plant and other cooling devices. .

The lubricant composition of the present invention can also be used as a metal working lubricant that does not contain a chlorine compound. For example, when hot-rolling metal materials such as steel materials and Al (aluminum) alloys, or when performing processing such as cutting, aluminum cold rolling oil, cutting oil, grinding oil, drawing oil, press The lubricant composition of the present invention can be used as a metal processing oil such as a processing oil or a metal plastic processing oil. The lubricant composition of the present invention is a metal working oil composition that can be used as a deterrent for wear, breakage, and surface roughness particularly during high-speed and high-load machining, and for low-speed and heavy cutting such as broaching and gun drilling. It is also useful.
The lubricant composition of the present invention can be used for various grease lubricants, magnetic recording medium lubricants, micromachine lubricants, artificial bone lubricants, and the like. Further, since the elemental composition of the lubricant composition can be a carbohydrate, it can be used, for example, as an emulsifying, dispersing, or solubilizing agent. By using an edible oil such as sorbitan fatty acid ester containing polyoxyethylene ether widely used for cake mix, salad dressing, shortening oil, chocolate, etc., to obtain a high-performance lubricating oil that is completely harmless to the human body Can do. Such lubricating oil can be used for manufacturing equipment and medical equipment members of food production lines.
Furthermore, the lubricant composition of the present invention can be used as cutting oil or rolling oil by emulsifying and dispersing it in an aqueous system or by dispersing it in a polar solvent or a resin medium.

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.

Hereinafter, 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.

Synthesis Example 1 Synthesis of P-1 To 97 g of 2-ethylhexyl glycidyl ether (manufactured by Tokyo Chemical Industry), 250 g of dimer acid (manufactured by Tsuno Foods Co., Ltd., Tsunodim 395) was added so that the molar ratio was 54/46, and nitrogen was added. The reaction was performed at 220 ° C. for 5 hours under an air stream. It was confirmed by GPC (Gel Permeation Chromatography) that a polyester compound (P-1) having a weight average molecular weight of 29000 was produced. The ¹ H-NMR of the polyester compound (P-1) is shown in FIG.

(Synthesis Example 2) Synthesis of P-2 A polyester compound (P-2) was synthesized in the same manner as in Synthesis Example 1 except that 2-ethylhexyl glycidyl ether in Synthesis Example 1 was changed to 1,2-hexanediol. It was confirmed by GPC that a polyester compound (P-2) having a weight average molecular weight of 15000 was produced.

(Synthesis Example 3) Synthesis of P-3 Except that the dimer acid of Synthesis Example 2 was changed to dodecenyl succinic anhydride and 1,2-hexanediol was changed to 3- (2-ethylhexyloxy) -1,2-propanediol A polyester compound (P-3) was synthesized in the same manner as in Synthesis Example 2. It was confirmed by GPC that a polyester compound (P-3) having a weight average molecular weight of 15000 was produced.

(Synthesis Example 4) Synthesis of P-4 To 84 g of 2-ethylhexyl glycidyl ether (manufactured by Tokyo Chemical Industry), 250 g of dimer acid (Tsunodaim 395 manufactured by Tsuno Foods Co., Ltd.) and 2-ethylhexyl so that the molar ratio is 42/42/8 13 g of oxyethanol (manufactured by Tokyo Chemical Industry) was added and reacted at 220 ° C. for 5 hours under a nitrogen stream.
When measured by GPC, a polyester compound (P-4) having a weight average molecular weight of 8,000 was produced. FIG. 2 shows the ¹ H-NMR of the polyester compound (P-4).

(Synthesis Example 5) Synthesis of P-6 As in Synthesis Example 1, except that 1,2-epoxyoctane, erucic acid dimer and 2-ethylhexyloxyethanol were added so that the molar ratio was 35/50/15. A polyester compound (P-6) was synthesized.

Synthesis Example 6 Synthesis of P-13 A polyester compound (P-13) was synthesized in the same manner as in Synthesis Example 1 except that 1,2-epoxypentane and dimer acid were added so that the molar ratio was 55/45. did.

Synthesis Example 7 Synthesis of P-18 A polyester compound (P-18) was synthesized in the same manner as in Synthesis Example 1 except that 1,2-epoxynonane and dimer acid were added so that the molar ratio was 55/45. did.

Synthesis Example 8 Synthesis of P-29 A polyester compound (P) was prepared in the same manner as in Synthesis Example 1 except that 1,2-epoxyhexane and 1,4-cyclohexanedicarboxylic acid were added so that the molar ratio was 55/45. -29) was synthesized.

(Synthesis of Comparative Compound Pc-1)
A polyester compound (Pc-1) was synthesized in the same manner as in Synthesis Example 1 except that 2,2-dimethylpropanediol and dimer acid were added in a molar ratio of 50/50.

(Synthesis of Comparative Compound Pc-2)
A polyester compound (Pc-2) was synthesized in the same manner as in Synthesis Example 1 except that 1,2-hexanediol and terephthalic acid were added in a molar ratio of 50/50.

(Synthesis of Comparative Compound Pc-3)
A polyester compound (Pc-3) was synthesized in the same manner as in Synthesis Example 1 except that 1,2-butanediol and dimer acid were added so that the molar ratio was 40/60.

(Examples 1 to 12 and Comparative Examples 1 to 4)
A polyester compound was added to the base oil shown in Table 2 so that the addition amount shown in Table 2 was obtained, and lubricant compositions of Examples 1 to 12 and Comparative Examples 1 to 4 were obtained. Base oils 1 to 3 are as follows.
Base oil 1: Super oil N46 (GrI, 40 ° C. kinematic viscosity 46 mm ² / s) manufactured by JX Nippon Mining & Metals
Base oil 2: Spectacin 4 (PAO, 40 ° C kinematic viscosity 19 mm ² / s) manufactured by ExxonMobil
Base oil 3: YUBASE3 manufactured by SK (GrIII, kinematic viscosity at 40 ° C., 20 mm ² / s)

(Evaluation)
The lubricant compositions obtained in Examples and Comparative Examples were evaluated by the following methods.

(Coefficient of friction)
About the lubricant composition of each Example and the comparative example, the friction coefficient was measured using the vibration-type friction-wear tester (The product made by Optimol Instruments Prutechnik GmbH, SRV 4). In the measurement of the friction coefficient, at a temperature of 40 ° C., a measurement condition (condition 1) with a vibration frequency of 50 Hz, a load of 150 N, and an amplitude of 2 mm and at a temperature of 80 ° C., a measurement condition with a vibration frequency of 50 Hz, a load of 300 N, and an amplitude of 2 mm (condition 2). ) Were subjected to a friction and wear test for 1 hour, and the coefficient of friction was measured after 30 minutes. A 10 mm SUJ-2 ball and a lower test piece 24 mm SUJ-2 disc were used for the upper test piece in the frictional wear test.
The other evaluation results were normalized by setting the friction coefficient in Condition 2 of Comparative Example 1 to 100%, and evaluated according to the following criteria. The smaller the value, the smaller the coefficient of friction, indicating better lubricating properties. It was judged that a, b, and c had a large reduction in the friction coefficient, and that the improvement effect was great. In the condition 1 test, an evaluation of c or higher was regarded as a pass evaluation, and in the test of condition 2, an evaluation of d or higher was regarded as a pass evaluation.
a: Less than 60% b: 60% or more and less than 70% c: 70% or more and less than 90% d: 90% or more and less than 100% e: 100% or more

(Base oil solubility)
1 to 5% by mass of the polyester compound used in each example and comparative example was dissolved in PAO oil (ExxonMobil, Spectacin 4), and the solubility was visually confirmed. In addition, base oil solubility made the evaluation more than C the pass evaluation.
A: 5% by mass of the polyester compound was completely dissolved B: 3% by mass of the polyester compound was completely dissolved, and when the 5% by mass of the polyester compound was dissolved, it was partially white.
C: 1% by mass of the polyester compound was completely dissolved, and when the 3% by mass of the polyester compound was dissolved, the color became partially white.
D: When the polyester compound of 1 mass% was dissolved, it became partially white.
E: A precipitate was generated when 1% by mass of the polyester compound was dissolved.

As shown in Table 2, it can be seen that the lubricant compositions obtained in the examples have a small coefficient of friction and can exhibit good lubricating performance. Moreover, the polyester compound used in the Examples was excellent in base oil solubility.
On the other hand, the lubricant composition obtained in the comparative example had a large friction coefficient and poor lubrication characteristics. Further, when the polyester compound was used in the comparative example, the polyester compound was not sufficiently dissolved in the base oil.

(Examples 21 to 24 and Comparative Example 21)
As a base oil 4, a commercially available engine oil (HONDA, Ultranext, 40 ° C. kinematic viscosity 17.42 mm ² / s) was used, and 1% by mass of the polyester compound shown in Table 3 was added. Prepared. This was evaluated by the same method as described above. In the evaluation of the friction coefficient, the friction coefficient in Condition 2 of Comparative Example 21 was used as a reference.

Even when the base oil 4 was used, good lubricating performance was exhibited, and the base oil solubility of the polyester compound was good.

(Example 31 and Comparative Examples 31 to 33)
The polyester compound shown in Table 4 and grease 1 (Mobil SHC Grease 460WT) were mixed to prepare a grease composition. This was evaluated by the same method as described above. In the evaluation of the friction coefficient, the friction coefficient in Condition 2 of Comparative Example 33 was used as a reference.

As shown in Table 4, the grease compositions obtained in the examples had good friction characteristics.

Claims (10)

1. A lubricant composition comprising a polyester compound having a structural unit represented by the following general formula (1);
   

   

   In general formula (1), A represents a single bond, an alkylene group which may have a substituent, or a group represented by — (CR ¹ R ² ) _m —O— (CR ³ R ⁴ ) _n —. Wherein R ¹ to R ⁴ each independently represents a hydrogen atom or a substituent, and m and n each independently represents an integer of 0 or more;
   B represents a single bond or a divalent linking group;
   Ra represents a substituent having 3 or more carbon atoms;
   Rb ¹ to Rb ⁴ each independently represents a hydrogen atom or a substituent, and Rb ¹ and Rb ³ may be bonded to each other to form a non-aromatic ring containing B.
2. 2. The lubricant composition according to claim 1, wherein each of Rb ¹ to Rb ⁴ independently represents a hydrogen atom, an alkyl group that may have a substituent, or an alkenyl group that may have a substituent.
3. The lubricant composition according to claim 1 or 2, wherein the A is a single bond.
4. The lubricant composition according to any one of claims 1 to 3, wherein the total number of carbon atoms of B and Rb ¹ to Rb ⁴ is 8 or more.
5. 5. The lubricant composition according to claim ¹ , wherein the total number of carbon atoms of B and Rb ¹ to Rb ⁴ is 14 or more.
6. The lubricant composition according to any one of claims 1 to 5, wherein Ra is an alkyl group having 3 or more carbon atoms which may have a substituent.
7. The lubricant composition according to any one of claims 1 to 6, wherein Ra is an alkyl group having 6 or more carbon atoms which may have a substituent.
8. The lubricant composition according to any one of claims 1 to 7, wherein Ra is an alkoxyalkyl group having 6 or more carbon atoms which may have a substituent.
9. A method for producing a lubricant composition comprising a step of synthesizing a polyester compound having a weight average molecular weight of 3000 or more from a compound represented by the following general formula (11) and a dicarboxylic acid represented by the following general formula (12);
   

   

   

   In general formula (11), A represents a single bond, an alkylene group which may have a substituent, or a group represented by — (CR ¹ R ² ) _m —O— (CR ³ R ⁴ ) _n —. Wherein R ¹ to R ⁴ each independently represents a hydrogen atom or a substituent, m and n each independently represents an integer of 0 or more; Ra represents a substituent having 3 or more carbon atoms;
   In the general formula (12), B represents a single bond or a divalent linking group, Rb ¹ to Rb ⁴ each independently represents a hydrogen atom or a substituent, and at least one of Rb ¹ to Rb ⁴ and B are mutually They may combine to form a ring.
10. A polyester compound containing a structural unit represented by the following general formula (21),
    The content of the structural unit in the polyester compound is 20 mol% or more,
    A polyester compound having a weight average molecular weight of 3000 or more;
    

    

    In General Formula (21), D represents a single bond or an alkylene group which may have a substituent;
    Rd and Rd ′ each independently represents a hydrogen atom, an optionally substituted alkyl group or an optionally substituted alkenyl group, and at least one of Rd and Rd ′ is a hydrogen atom;
    One of Rc and Rc ′ is a hydrogen atom, and the other of Rc and Rc ′ is an alkyl group having 7 or more carbon atoms which may have a substituent.

Images