阅读说明：本技术 包含二价阳离子和一价阴离子的离子液体以及包含该离子液体的润滑剂组合物 (Ionic liquids comprising divalent cations and monovalent anions and lubricant compositions comprising the same ) 是由 申相慧 H·N·宋 沈由那 黄善爱 于 2020-08-05 设计创作，主要内容包括：本申请公开了一种离子液体,其具有在低温维持的耐磨性,并且含有包括双(铵)和双(鏻)中的至少一者的二价阳离子以及包括磺酸根和磷酸根中的至少一者的一价阴离子,并且还披露了包含该离子液体的润滑剂组合物。(Disclosed is an ionic liquid having wear resistance maintained at low temperatures and containing a divalent cation including at least one of bis (ammonium) and bis (phosphonium) and a monovalent anion including at least one of a sulfonate group and a phosphate group, and a lubricant composition comprising the same.)

1. An ionic liquid comprising:

a divalent cation comprising at least one of bis (ammonium) and bis (phosphonium); and

a monovalent anion comprising at least one of a sulfonate and a phosphate.

2. An ionic liquid according to claim 1, wherein the bis (ammonium) has the structure of formula 1 below:

[ chemical formula 1]

In chemical formula 1, R₁And R₂Each independently is hydrogen, (C1-C20) hydrocarbyl, substituted (C1-C20) hydrocarbyl, (C1-C20) heterohydrocarbyl, or substituted (C1-C20) heterohydrocarbyl, and

R₃is (CH)₂)_nWherein n is more than or equal to 1 and less than or equal to 20.

3. The method of claim 2An ionic liquid, wherein in chemical formula 1, R₁And R₂Each independently is (C1-C20) alkyl, (C2-C20) alkenyl, (C2-C20) alkynyl, (C3-C7) cycloalkyl, (C5-C20) heteroalkyl, (C6-C20) aryl, (C6-C20) ar (C1-C10) alkyl, (C1-C10) alkoxy, (C6-C20) aryloxy, (C1-C10) alkoxycarbonyl (C1-C20) alkyl or (C1-C20) alkylcarbonyl.

4. An ionic liquid according to claim 2, wherein R in chemical formula 1₁And R₂Each independently is (C1-C8) alkyl, and R₃Is (CH)₂)_nWherein n is more than or equal to 1 and less than or equal to 12.

5. The ionic liquid of claim 1, wherein the bis (phosphorus) has the structure of formula 2 below:

[ chemical formula 2]

In chemical formula 2, R₁And R₂Each independently is hydrogen, (C1-C20) hydrocarbyl, substituted (C1-C20) hydrocarbyl, (C1-C20) heterohydrocarbyl, or substituted (C1-C20) heterohydrocarbyl, and

R₃is (CH)₂)_nWherein n is more than or equal to 1 and less than or equal to 20.

6. The ionic liquid according to claim 5, wherein R in chemical formula 2₁And R₂Each independently is (C1-C20) alkyl, (C2-C20) alkenyl, (C2-C20) alkynyl, (C3-C7) cycloalkyl, (C5-C20) heteroalkyl, (C6-C20) aryl, (C6-C20) ar (C1-C10) alkyl, (C1-C10) alkoxy, (C6-C20) aryloxy, (C1-C10) alkoxycarbonyl (C1-C20) alkyl or (C1-C20) alkylcarbonyl.

7. The ionic liquid according to claim 5, wherein R in chemical formula 2₁And R₂Each independently is (C1-C8) alkyl, and R₃Is (CH)₂)_nWherein n is more than or equal to 1 and less than or equal to 12.

8. The ionic liquid of claim 1, wherein the sulfonate has the structure of formula 5:

[ chemical formula 5]

In chemical formula 5, R₄Is (C1-C12) alkyl.

9. The ionic liquid of claim 1, wherein the sulfonate has the structure of formula 6:

[ chemical formula 6]

In chemical formula 6, R₁And R₂Each independently hydrogen, (C1-C20) hydrocarbyl, substituted (C1-C20) hydrocarbyl, (C1-C20) heterohydrocarbyl, or substituted (C1-C20) heterohydrocarbyl.

10. An ionic liquid according to claim 9, wherein R in chemical formula 6₁And R₂Each independently is (C1-C20) alkyl, (C2-C20) alkenyl, (C2-C20) alkynyl, (C3-C7) cycloalkyl, (C5-C20) heteroalkyl, (C6-C20) aryl, (C6-C20) ar (C1-C10) alkyl, (C1-C10) alkoxy, (C6-C20) aryloxy, (C1-C10) alkoxycarbonyl (C1-C20) alkyl or (C1-C20) alkylcarbonyl.

11. An ionic liquid according to claim 9, wherein R in chemical formula 6₁And R₂Each independently is a (C3-C10) alkyl group.

12. The ionic liquid according to claim 1, wherein the phosphate has the structure of the following chemical formula 7:

[ chemical formula 7]

In chemical formula 7, R₄And R₅Each independently hydrogen, (C1-C20) hydrocarbyl, substituted (C1-C20) hydrocarbyl, (C1-C20) heterohydrocarbyl, or substituted (C1-C20) heterohydrocarbyl.

13. An ionic liquid according to claim 12, wherein in chemical formula 7, R₄And R₅Each independently is (C1-C20) alkyl, (C2-C20) alkenyl, (C2-C20) alkynyl, (C3-C7) cycloalkyl, (C5-C20) heteroalkyl, (C6-C20) aryl, (C6-C20) ar (C1-C10) alkyl, (C1-C10) alkoxy, (C6-C20) aryloxy, (C1-C10) alkoxycarbonyl (C1-C20) alkyl or (C1-C20) alkylcarbonyl.

14. An ionic liquid according to claim 12, wherein in chemical formula 7, R₄And R₅Each independently is a (C3-C10) alkyl group.

15. A lubricant composition comprising:

an ionic liquid according to any one of claims 1 to 14;

at least one additive; and

a base oil.

16. The lubricant composition of claim 15, comprising 0.05 wt.% to 20 wt.% of the ionic liquid and 0.1 wt.% to 50 wt.% of the at least one additive.

17. The lubricant composition of claim 16, wherein the at least one additive is at least one selected from the group consisting of antioxidants, metal cleaners, corrosion inhibitors, foam inhibitors, pour point depressants, viscosity modifiers, dispersants, and anti-wear agents.

Technical Field

The present disclosure relates to ionic liquids comprising divalent cations and monovalent anions and lubricant compositions comprising the ionic liquids.

Background

It is reported that an ionic liquid composed of a cation and an anion has excellent thermal stability and high ionic conductivity, and is stable when exposed to an ambient atmosphere (Journal of the Chemical Society, Chemical Communications,1992, page 965). Further, intensive studies are being conducted to apply an ionic liquid to various end uses such as an electrolyte for a solar cell (japanese patent application laid-open No.2003 31270), an extraction separation solvent, a reaction solvent, and the like by utilizing properties of the ionic liquid such as thermal stability (low volatility, flame retardancy), high ion density (high ionic conductivity), high heat capacity, low viscosity, and the like.

The use of such an ionic liquid as a lubricating base oil has been previously disclosed (International publication No. 2005/035702). Since the ionic liquid is designed such that molecules are bonded to each other through strong ionic bonds, the ionic liquid is not easily volatilized, has flame retardancy, and has high heat resistance and high oxidation resistance. Therefore, the ionic liquid has low viscosity, low evaporation property and excellent heat resistance.

Typically, the anion of the ionic liquid comprises a halogen atom, such as a fluorine atom. In order to design the molecular structure of ionic liquids that are liquid at room temperature rather than solid, atoms with high electronegativity, such as halogens, are introduced into the anion. This acts to reduce the electrostatic attraction between the cation and anion by electron delocalization effects.

However, when halogen atoms such as fluorine atoms are contained, the ionic liquid is susceptible to moisture, and corrosive gas and corrosive substances are generated when exposed to moisture. In addition, fluorine is expensive, and therefore, an ionic liquid containing a fluorine atom is not economical.

Disclosure of Invention

Accordingly, it is an aspect of the present disclosure to provide an ionic liquid comprising a divalent cation and an anion, which has excellent corrosion resistance and wear resistance, and a lubricant composition comprising the same.

Embodiments of the present disclosure provide an ionic liquid comprising a divalent cation comprising at least one of bis (ammonium) and bis (phosphonium), and a monovalent anion comprising at least one of sulfonate and phosphate.

Herein, the bis (ammonium) may have the structure of the following chemical formula 1:

[ chemical formula 1]

In chemical formula 1，R₁And R₂Each independently can be hydrogen, (C1-C20) hydrocarbyl, substituted (C1-C20) hydrocarbyl, (C1-C20) heterohydrocarbyl, or substituted (C1-C20) heterohydrocarbyl, and R₃Can be (CH)₂)_nWherein n is more than or equal to 1 and less than or equal to 20.

In chemical formula 1, R₁And R₂Each independently can be (C1-C20) alkyl, (C2-C20) alkenyl, (C2-C20) alkynyl, (C3-C7) cycloalkyl, (C5-C20) heteroalkyl, (C6-C20) aryl, (C6-C20) ar (C1-C10) alkyl, (C1-C10) alkoxy, (C6-C20) aryloxy, (C1-C10) alkoxycarbonyl (C1-C20) alkyl or (C1-C20) alkylcarbonyl.

In chemical formula 1, R₁And R₂Each independently may be (C1-C8) alkyl, and R₃Can be (CH)₂)_nWherein n is more than or equal to 1 and less than or equal to 12.

The bis (phosphonium) may have the structure of the following chemical formula 2:

[ chemical formula 2]

In chemical formula 2, R₁And R₂Each independently can be hydrogen, (C1-C20) hydrocarbyl, substituted (C1-C20) hydrocarbyl, (C1-C20) heterohydrocarbyl, or substituted (C1-C20) heterohydrocarbyl, and R₃Can be (CH)₂)_nWherein n is more than or equal to 1 and less than or equal to 20.

In chemical formula 2, R₁And R₂Each independently can be (C1-C20) alkyl, (C2-C20) alkenyl, (C2-C20) alkynyl, (C3-C7) cycloalkyl, (C5-C20) heteroalkyl, (C6-C20) aryl, (C6-C20) ar (C1-C10) alkyl, (C1-C10) alkoxy, (C6-C20) aryloxy, (C1-C10) alkoxycarbonyl (C1-C20) alkyl or (C1-C20) alkylcarbonyl.

In chemical formula 2, R₁And R₂Each independently may be (C1-C8) alkyl, and R₃Can be (CH)₂)_nWherein n is more than or equal to 1 and less than or equal to 12.

The sulfonate group may have a structure of the following chemical formula 5:

[ chemical formula 5]

In chemical formula 5, R₄May be a (C1-C12) alkyl group.

The sulfonate group may have a structure of the following chemical formula 6:

[ chemical formula 6]

In chemical formula 6, R₁And R₂Each independently can be hydrogen, (C1-C20) hydrocarbyl, substituted (C1-C20) hydrocarbyl, (C1-C20) heterohydrocarbyl, or substituted (C1-C20) heterohydrocarbyl.

In chemical formula 6, R₁And R₂Each independently can be (C1-C20) alkyl, (C2-C20) alkenyl, (C2-C20) alkynyl, (C3-C7) cycloalkyl, (C5-C20) heteroalkyl, (C6-C20) aryl, (C6-C20) ar (C1-C10) alkyl, (C1-C10) alkoxy, (C6-C20) aryloxy, (C1-C10) alkoxycarbonyl (C1-C20) alkyl or (C1-C20) alkylcarbonyl.

In chemical formula 6, R₁And R₂Each may independently be a (C3-C10) alkyl group.

The phosphate group may have the structure of the following chemical formula 7:

[ chemical formula 7]

In chemical formula 7, R₄And R₅Each independently can be hydrogen, (C1-C20) hydrocarbyl, substituted (C1-C20) hydrocarbyl, (C1-C20) heterohydrocarbyl, or substituted (C1-C20) heterohydrocarbyl.

In chemical formula 7, R₄And R₅Each independently may be (C1-C20) alkyl, (C2-C20) alkenyl, (C2-C20) alkynyl, (C3-C7) cycloalkyl, (C5-C20) heteroalkyl, (C6-C20) aryl, (C6-C20) ar (C1-C10) alkyl, (C1-C1) aryl10) Alkoxy, (C6-C20) aryloxy, (C1-C10) alkoxycarbonyl (C1-C20) alkyl or (C1-C20) alkylcarbonyl.

In chemical formula 7, R₄And R₅Each may independently be a (C3-C10) alkyl group.

Another embodiment of the present disclosure provides a lubricant composition comprising the above ionic liquid, at least one additive, and a base oil.

The lubricant composition may comprise from 0.05 wt% to 20 wt% of the ionic liquid and from 0.1 wt% to 50 wt% of the at least one additive.

Herein, the at least one additive may be at least one selected from the group consisting of an antioxidant, a metal cleaner, an anticorrosive agent, a foam inhibitor, a pour point depressant, a viscosity modifier, a dispersant, and an anti-wear agent.

According to embodiments of the present disclosure, ionic liquids comprise a specific divalent cation and a specific monovalent anion, thereby exhibiting high wear resistance and very low corrosion tendency.

Drawings

Figure 1 illustrates a compound comprising a bis (ammonium) cation and an alkylsulfonate anion according to one embodiment of the present disclosure¹H-NMR spectrum;

FIG. 2 illustrates a compound comprising a bis (ammonium) cation and an alkyl phosphate anion, according to another embodiment of the present disclosure¹H-NMR spectrum;

FIG. 3 illustrates a compound comprising a bis (phosphonium) cation and an alkylsulfonate anion according to yet another embodiment of the present disclosure¹H-NMR spectrum;

FIG. 4 illustrates a compound comprising a bis (phosphorus) cation and an alkyl phosphate anion, according to yet another embodiment of the present disclosure¹H-NMR spectrum;

fig. 5 is a graph illustrating the wear resistance of ionic liquids at 100 ℃ according to an embodiment of the present disclosure; and is

Fig. 6 is a graph illustrating the wear resistance of ionic liquids at 60 ℃ according to an embodiment of the present disclosure.

Detailed Description

Objects, specific advantages and novel features of the disclosure will become apparent from the following detailed description of the preferred embodiment when considered in conjunction with the drawings, but the disclosure is not necessarily limited thereto. Further, it should be noted in the description of the present disclosure that a detailed description of known technologies related to the present disclosure may make the gist of the present disclosure unclear, and the description will be omitted.

Definition of

Terms used in the present disclosure may be defined as follows.

"hydrocarbyl" refers to a group containing only carbon and hydrogen atoms, which may be saturated or unsaturated, and which may be straight, branched, or cyclic. Herein, "cyclic" may include both aromatic and non-aromatic.

"substituted hydrocarbyl" refers to hydrocarbyl substituted with at least one substituent.

"heterohydrocarbyl" is a hydrocarbyl group in which at least one carbon atom is replaced with a heteroatom, and examples of heteroatoms may include O, S, N, B, Si and P. For example, the heterohydrocarbyl group may also include a heterocyclic ring in which at least one carbon atom in the aromatic ring is replaced with a heteroatom.

"substituted heterohydrocarbyl" refers to a heterohydrocarbyl substituted with at least one substituent.

"alkyl" refers to a saturated straight or branched chain hydrocarbon. For example, a (C1-C6) alkyl group includes a straight or branched chain group of 1 to 6 carbon atoms. Examples of alkyl groups may include, but are not limited to, methyl, ethyl, propyl, isopropyl, 2-methyl-1-butyl, 3-methyl-2-butyl, 2-methyl-1-pentyl, 3-methyl-1-pentyl, 4-methyl-1-pentyl, 2-methyl-2-pentyl, 3-methyl-2-pentyl, 4-methyl-2-pentyl, 2-dimethyl-1-butyl, 3-dimethyl-1-butyl, 2-ethyl-1-butyl, isobutyl, tert-butyl, pentyl, isopentyl, neopentyl, hexyl, and the like.

"alkenyl" refers to an unsaturated straight or branched chain hydrocarbon having at least one carbon-carbon double bond. For example, a (C2-C6) alkenyl group includes a straight or branched chain group of 2 to 6 carbon atoms. Examples of alkenyl groups may include, but are not limited to, vinyl, allyl, butenyl, pentenyl, and the like.

"alkynyl" refers to an unsaturated straight or branched chain hydrocarbon having at least one carbon-carbon triple bond. For example, (C2-C6) alkynyl includes straight or branched chain groups of 2 to 6 carbon atoms. Examples of alkynyl groups may include, but are not limited to, ethynyl, propynyl, butynyl, pentynyl, hexynyl, methylpropynyl, and the like.

By "cycloalkyl", (C3-C6) cycloalkyl is meant a monocyclic saturated hydrocarbon group of 3 to 6 carbon atoms. Examples of cycloalkyl groups may include, but are not limited to, cyclohexyl, cyclopentyl, cyclobutyl, and cyclopropyl.

"alkoxy" refers to a straight or branched chain alkyl (alkyl-O-) group attached to an oxygen. For example, a (C1-C6) alkoxy group includes an alkyl group of 1 to 6 carbon atoms. Examples of alkoxy groups may include, but are not limited to, methoxy, ethoxy, isopropoxy, and the like.

"alkoxyalkyl" refers to a straight or branched alkyl group (alkyl-O-alkyl-), attached to oxygen, and attached to a second straight or branched alkyl group. For example, (C1-C6) alkoxy (C1-C6) alkyl includes alkyl groups each containing 1 to 6 carbon atoms. Examples of alkoxyalkyl groups may include, but are not limited to, methoxymethyl, 2-methoxyethyl, 1-methoxyethyl, 2-methoxypropyl, ethoxymethyl, 2-isopropoxyethyl, and the like.

"alkoxycarbonyl" refers to a straight or branched chain alkyl (alkyl-O-C (O) -alkyl) group attached to oxygen and to a carbonyl group. For example, (C1-C6) alkoxycarbonyl includes alkyl groups containing 1 to 6 carbon atoms. Examples of the alkoxycarbonyl group may include, but are not limited to, a methoxycarbonyl group, an ethoxycarbonyl group, a tert-butoxycarbonyl group, and the like.

"Alkylcarbonyl" means a straight or branched chain alkyl group (alkyl-C (O)) attached to a carbonyl group. For example, (C1-C6) alkylcarbonyl refers to alkylcarbonyl containing 1 to 6 carbon atoms. Examples of alkylcarbonyl groups may include, but are not limited to, acetyl, propionyl, isopropionyl, butyryl, and the like.

Ionic liquids

According to the present disclosure, the ionic liquid may comprise a divalent cation comprising bis (ammonium) and/or bis (phosphonium) and a monovalent anion comprising a sulfonate and/or a phosphate.

Divalent cation

Ionic liquids comprising divalent cations are more charged and have a higher polarity than ionic liquids comprising monovalent cations. Since the ionic liquid containing a divalent cation has a strong polarity, the ionic liquid containing a divalent cation has a strong interaction with the metal surface, and a thin film capable of functioning as a protective film can be advantageously formed on the metal surface subjected to friction.

When a conventional ionic liquid containing a monovalent cation forms a protective film on a metal surface, the protective film is provided in the form of a double layer in a direction perpendicular to the metal surface. Since the ionic liquid containing a divalent cation has stronger ionic interaction, when a protective film is formed on a metal surface, a thicker protective film (i.e., a lubricating film) composed of multiple layers can be formed.

Compared to ionic liquids comprising monovalent cations, ionic liquids comprising divalent cations have higher liquid density, higher decomposition temperature (Td), higher glass transition temperature (Tg), higher melting point (Tm) and higher shear viscosity.

Therefore, the ionic liquid of the present disclosure is more thermally stable due to a high Td, and further, due to its high density and tendency to suppress decomposition due to the nature of its molecular structure, it is advantageous to apply the ionic liquid of the present disclosure to the field where local heating occurs or the field of lubricants (particularly those used at high temperatures). In particular, the ionic liquids comprising divalent cations of the present disclosure have high shear viscosity and are therefore effective in reducing the viscosity loss of the oil due to shear stress. In particular, since the ionic liquid comprising a divalent cation of the present disclosure has high viscosity, viscosity loss of oil is reduced in a region where severe mechanical movement is performed, so that the ionic liquid of the present disclosure has excellent wear resistance compared to the ionic liquid comprising a monovalent cation.

In exemplary embodiments, the bis (ammonium) of the present disclosure may have the structure of the following chemical formula 1.

[ chemical formula 1]

In chemical formula 1, R₁And R₂Each independently can be hydrogen, (C1-C20) hydrocarbyl, substituted (C1-C20) hydrocarbyl, (C1-C20) heterohydrocarbyl, or substituted (C1-C20) heterohydrocarbyl, and R₃Can be (CH)₂)_nWherein n is more than or equal to 1 and less than or equal to 20.

Further, in chemical formula 1, 3R₁Each independently of the other, the same or different, and 3R₂Each independently the same or different from each other.

Further, in chemical formula 1, R₁And R₂May each independently be (C1-C20) alkyl, (C2-C20) alkenyl, (C2-C20) alkynyl, (C3-C7) cycloalkyl, (C5-C20) heteroalkyl, (C6-C20) aryl, (C6-C20) ar (C1-C10) alkyl, (C1-C10) alkoxy, (C6-C20) aryloxy, (C1-C10) alkoxycarbonyl (C1-C20) alkyl or (C1-C20) alkylcarbonyl.

Further, in chemical formula 1, R₁And R₂May each independently be a (C1-C8) alkyl group, and R₃Can be (CH)₂)_nWherein n is more than or equal to 1 and less than or equal to 12.

In a specific embodiment, the bis (ammonium) may have the structure of the following chemical formula 3.

[ chemical formula 3]

In another exemplary embodiment, the bis (phosphorus) of the present disclosure may have the structure of the following chemical formula 2.

[ chemical formula 2]

In chemical formula 2, R₁And R₂May each independently be hydrogen, (C1-C20) hydrocarbyl, substituted (C1-C20) hydrocarbyl, (C1-C20) heterohydrocarbyl, or substituted (C1-C20) heterohydrocarbyl, and R is₃Can be (CH)₂)_nWherein n is more than or equal to 1 and less than or equal to 20.

Further, in chemical formula 2, 3R₁Each independently of the other, the same or different, and 3R₂Each independently the same or different from each other.

Further, in chemical formula 2, R₁And R₂May each independently be a (C1-C8) alkyl group, and R₃Can be (CH)₂)_nWherein n is more than or equal to 1 and less than or equal to 12.

In one embodiment, the bis (phosphorus) may have the structure of the following chemical formula 4.

[ chemical formula 4]

The specific cation having the structure of chemical formula 1 to chemical formula 4 according to the present disclosure is designed to have a specific chain length and structure, and thus can be mixed with the specific anion according to the present disclosure with high miscibility. Therefore, the ionic liquid according to the present disclosure may have excellent effects in which physicochemical properties such as hydrophilicity/hydrophobicity, solubility, polarity, viscosity, and density of the ionic liquid of the present disclosure are suitable for a lubricant.

Anion(s)

The anion of the ionic liquid according to the present disclosure is free of halogen atoms. In the ionic liquid of the present disclosure, a sulfonate group and/or a phosphate group, which are enlarged due to substitution with a branched alkyl chain, are introduced into an anion, thereby causing an electron delocalization effect.

By electron delocalization, the ionic liquids of the present disclosure can remain liquid at room temperature without halogen atoms, and can exhibit hydrophobicity. In addition, since the ionic liquid of the present disclosure does not contain halogen atoms, it has corrosion resistance and excellent economic efficiency.

In exemplary embodiments, the sulfonate of the present disclosure may have the structure of the following chemical formula 5.

[ chemical formula 5]

In chemical formula 5, R₄May be a (C1-C12) alkyl group.

In another exemplary embodiment, the sulfonate of the present disclosure may have the structure of the following chemical formula 6.

[ chemical formula 6]

In chemical formula 6, R₁And R₂Each independently can be hydrogen, (C1-C20) hydrocarbyl, substituted (C1-C20) hydrocarbyl, (C1-C20) heterohydrocarbyl, or substituted (C1-C20) heterohydrocarbyl.

For example, in chemical formula 6, R₁And R₂May each independently be (C1-C20) alkyl, (C2-C20) alkenyl, (C2-C20) alkynyl, (C3-C7) cycloalkyl, (C5-C20) heteroalkyl, (C6-C20) aryl, (C6-C20) ar (C1-C10) alkyl, (C1-C10) alkoxy, (C6-C20) aryloxy, (C1-C10) alkoxycarbonyl (C1-C20) alkyl or (C1-C20) alkylcarbonyl.

Further, in chemical formula 6, R₁And R₂May each independently be a (C3-C10) alkyl group. In a specific embodiment, the phosphate group may have the structure of the following chemical formula 8.

[ chemical formula 8]

In another exemplary embodiment, the phosphate of the present disclosure may have the structure of the following chemical formula 7.

[ chemical formula 7]

In chemical formula 7, R₄And R₅May each independently be hydrogen, (C1-C20) hydrocarbyl, substituted (C1-C20) hydrocarbyl, (C1-C20) heterohydrocarbyl, or substituted (C1-C20) heterohydrocarbyl.

Further, in chemical formula 7, R₄And R₅May each independently be (C1-C20) alkyl, (C2-C20) alkenyl, (C2-C20) alkynyl, (C3-C7) cycloalkyl, (C5-C20) heteroalkyl, (C6-C20) aryl, (C6-C20) ar (C1-C10) alkyl, (C1-C10) alkoxy, (C6-C20) aryloxy, (C1-C10) alkoxycarbonyl (C1-C20) alkyl or (C1-C20) alkylcarbonyl.

In a specific embodiment, in chemical formula 7, R₄And R₅May each independently be a (C3-C10) alkyl group.

In a specific embodiment, the phosphate group may have the structure of the following chemical formula 9.

[ chemical formula 9]

The specific anion having the structure of chemical formula 5 to chemical formula 9 according to the present disclosure is designed to have a specific chain length and structure, and thus can be combined with the specific cation according to the present disclosure in high miscibility. Therefore, the ionic liquid according to the present disclosure may have excellent effects in which physicochemical properties such as hydrophilicity/hydrophobicity, solubility, polarity, viscosity, and density of the ionic liquid of the present disclosure are suitable for a lubricant.

Lubricant composition

Further, lubricant compositions according to the present disclosure can be prepared by mixing the base oil with the above-described specific ionic liquids and additives in predetermined amounts.

For example, a lubricant composition according to the present disclosure may comprise from 0.05 wt% to 20 wt%, from 0.1 wt% to 5 wt%, or from 0.5 wt% to 5 wt% of an ionic liquid.

If the amount of the ionic liquid is less than 0.05 wt%, miscibility between the ionic liquid and other additives may deteriorate, or formation of an abrasion-reducing film may become difficult, thereby making it difficult to exhibit abrasion resistance. On the other hand, if the amount of the ionic liquid exceeds 20% by weight, it is difficult to achieve a lubricant viscosity suitable for lubricating performance.

The base oil used in the lubricant composition of the present disclosure may be at least one selected from among synthetic oils, mineral oils, and natural oils, and the type of the base oil is not particularly limited.

The synthetic oil may be selected from ester compounds composed of at least one of aliphatic or aromatic dicarboxylic, tricarboxylic or tetracarboxylic acids and C7 to C22 alcohols; polyphenylene ether or alkyl diphenyl ether or alkyl triphenyl ether; ester compounds composed of trimethylolpropane, pentaerythritol or dipentaerythritol and C7 to C22 aliphatic carboxylic acids; ester compounds composed of C7 to C22 alcohols and C18 dimer acid; a complex ester; and mixtures thereof. In addition, the synthetic oil may be selected from polyalphaolefins, alkylnaphthalenes, alkylbenzenes, polyethylene glycols, silicone oils, and perfluoropolyethers.

Examples of the mineral oils may generally include those obtained by subjecting an atmospheric residue obtained by atmospheric distillation of crude oil to desulfurization, hydrocracking and fractionation to a desired viscosity grade, and those obtained by subjecting an atmospheric residue to solvent dewaxing or catalytic dewaxing, and if necessary, solvent extraction and hydrogenation. Further, examples of the mineral oil may include: a paraffin isomerized base oil obtained by hydroisomerization of paraffin by-products in the dewaxing process during base oil manufacture, wherein the atmospheric distillation residue is further vacuum distilled, fractionated to a desired viscosity grade, solvent refined, hydrofinished and solvent dewaxed; and a gas-liquid (GTL) wax isomerized base oil obtained by isomerizing a GTL wax prepared by a Fisher-Tropsch process, and the like.

Examples of natural oils may include oils transformed with fatty acids derived from animal and vegetable oils. Examples of the animal oil may include fish oil, beef tallow, lard, mutton fat, butter, and the like, and examples of the vegetable oil may include sunflower oil, canola oil, palm oil, corn oil, cottonseed oil, rapeseed oil, linseed oil, safflower oil, oat oil, olive oil, palm oil, peanut oil, almond oil, avocado oil, olive oil, camellia oil, rice bran oil, cottonseed oil, peanut oil, walnut oil, rapeseed oil, rice bran oil, linseed oil, sesame oil, soybean oil, castor oil, cocoa butter, palm kernel oil, and the like.

As described above, the ionic liquid composed of specific cations and anions according to the present disclosure can be effectively mixed with the base oil due to a specific combination.

Furthermore, the lubricant composition comprising the ionic liquid according to the present disclosure has excellent wear resistance and corrosion resistance compared to existing lubricant compositions.

Further, the lubricant composition according to the present disclosure may further include at least one additive selected from the group consisting of an antioxidant, a metal cleaner, an anticorrosive agent, a foam inhibitor, a pour point depressant, a viscosity modifier, a dispersant, and an anti-wear agent.

Antioxidants may include alkylated diphenylamines, N-alkylated phenylenediamines, hindered phenols, alkylated hydroquinones, hydroxylated thiodiphenyl ethers, alkylidenebisphenols, oil soluble copper compounds, and the like. The metal cleaner may include a metal phenate, a metal sulfonate, a metal salicylate, etc., and the corrosion inhibitor may include a BTA (benzotriazole) -containing compound. The foam inhibitor may include polyoxyalkylene polyol or the like, the pour point depressant may include poly (methyl methacrylate) or the like, and the viscosity modifier may include polyisobutylene, polymethacrylate or the like. The dispersant may include polyisobutylene succinimides, polyisobutylene succinate esters, mannich base ashless dispersants, and the like, and the anti-wear agent may include organo borates, organo phosphites, sulfur-containing organic compounds, zinc dialkyldithiophosphates, zinc diaryldithiophosphates, phosphosulfurized hydrocarbons, and the like.

These additives are mixed with the base oil in an amount effective to impart additional functionality to the lubricant composition.

For example, a lubricant composition according to the present disclosure may include 0.1 wt% to 50 wt%, 1 wt% to 40 wt%, or 5 wt% to 30 wt% of at least one additive.

Representative effective amounts of additives are shown in table 1 below.

[ Table 1]

Composition of	Typical composition (% by weight)	Preferred composition (weight%)
			Base oil	Balance of	Balance of
Antioxidant agent	0-5.0	0.01-3.0
			Metal cleaning agent	0.1-15.0	0.2-8.0
Corrosion inhibitor	0-5.0	0-2.0
			Foam inhibitor	0-5.0	0.001-0.15
Pour point depressant	0.01-5.0	0.01-1.5
			Viscosity modifier	0.01-10.0	0.25-7.0
Dispersing agent	0.5-5.0	1.0-2.5
			Wear-resisting agent	0.01-3.0	0.3-2.0

Table 1 above shows typical effective amounts of additives commonly used in lubricant compositions. The amounts of additives shown in table 1 represent effective amounts and types of commonly used additives and do not limit the scope of the present disclosure. In addition, lubricant compositions according to the present disclosure may include other additives.

The present disclosure will be better understood by the following examples, which should not be construed as limiting the scope of the present disclosure.

Example 1: synthesis of Compound A (bis (ammonium) cation & alkyl sulfonate anion)

[ Compound A ]

Scheme 1

Step 1

By dissolving 4g (16.4mmol) of 1, 6-dibromohexane and 17.4g (49.2mmol) of trioctylamine in 120ml of acetonitrile (CH)₃CN) to prepare a mixture. The mixture was heated at 90 ℃ under reflux for 3 days and allowed to react. The reaction product was cooled to room temperature, and then acetonitrile was removed under reduced pressure, thereby obtaining a white viscous solid. To remove the unreacted trioctylamine, 120ml of hexane was added thereto, followed by stirring at room temperature for 1 hour, and the filtrate was removed using a filter. 120ml of diethyl ether was added thereto, followed by stirring at room temperature for 1 hour, and the filtrate was removed using a filter, whereby 12.5g of a white solid was obtained (yield: 80%).

Step 2

4.7g (10.6mmol) of the sodium salt of bis- (2-ethylhexyl) sulfosuccinic acid are dissolved in 40ml of water and stirred. 5g (5.3mmol) of N, N-hexaoctylhexane-1, 6-diammonium bromide synthesized in step 1 was dissolved in 40ml of ethyl acetate, and the resulting solution was added to the above sodium salt solution. The resulting mixture was stirred at room temperature overnight and then allowed to stand, after which the aqueous layer was removed. The organic layer was washed twice with 40ml of water, and then ethyl acetate was removed under reduced pressure, whereby 8.3g of compound A (yield: 97%) as a colorless transparent liquid was obtained. Of Compound A¹The H-NMR spectrum is shown in FIG. 1.

Example 2: synthesis of Compound B (bis (ammonium) cation & alkylphosphate anion)

[ Compound B ]

Scheme 2

Step 1

Same as in step 1 of compound a.

Step 2

2.0g (6.3mmol) of bis- (2-ethylhexyl) phosphate are dissolved in 15ml of waterNeutralizing and stirring. 0.25g (6.3mmol) of sodium hydroxide was added thereto, and the resulting mixture was stirred at room temperature for 1 hour. 3g (3.15mmol) of N, N-hexaoctylhexane-1, 6-diammonium bromide synthesized in step 1 was dissolved in 30ml of ethyl acetate, and the resulting solution was added to the above sodium salt solution. The resulting mixture was stirred at room temperature overnight and then allowed to stand, after which the aqueous layer was removed. The organic layer was washed twice with water (15ml), and then ethyl acetate was removed under reduced pressure, whereby 4.3g of compound B (yield: 95%) as an opaque liquid was obtained. Of compounds B¹The H-NMR spectrum is shown in FIG. 2.

Example 3: synthesis of Compound C (bis (phosphonium) cation & alkylsulfonate anion)

[ Compound C ]

Scheme 3

2.1g (6.3mmol) of 1, 12-dibromo-dodecane and 3.6g (12.6mmol) of trihexylphosphine were mixed, stirred overnight at 80 ℃ under nitrogen atmosphere, and cooled to room temperature, and then 60ml of hexane was added to the reaction product. To this were added 5.6g (12.6mmol) of bis- (2-ethylhexyl) sulfosuccinic acid sodium salt and 6ml of water, and the resulting mixture was stirred at room temperature overnight and then allowed to stand. Subsequently, the aqueous layer was removed and the organic layer was washed twice with 10ml of water. Then, the hexane was removed under reduced pressure, whereby 9g of compound C was obtained as a pale yellow liquid (yield: 90%). Of compound C¹The H-NMR spectrum is shown in FIG. 3.

Example 4: synthesis of Compound D (bis (phosphonium) cation & alkylphosphate anion)

[ Compound D ]

Scheme 4

2.1g (6.3mmol) of 1, 12-dibromo-dodecane and 3.6g (12.6mmol) of trihexylphosphine were mixed, stirred overnight at 80 ℃ under nitrogen atmosphere, and cooled to room temperature, and then 60ml of hexane was added to the reaction product. 4.1g (12.6mmol) of bis- (2-ethylhexyl) phosphate, 0.5g (12.6mmol) of sodium hydroxide and 6ml of water were added thereto, and the resulting mixture was stirred at room temperature overnight and then allowed to stand. Subsequently, the aqueous layer was removed and the organic layer was washed twice with 10ml of water. Then, hexane was removed under reduced pressure, whereby 7.4g of compound D (yield: 85%) as an opaque liquid was obtained. Of Compound D¹The H-NMR spectrum is shown in FIG. 4.

Example 5: synthesis of Compound E (bis (ammonium) cation & alkylsulfonate anion)

Scheme 5

Step 1

By dissolving 1, 6-dibromohexane (4g, 16.4mmol) and N, N-diethylbenzylamine (5.35g, 32.8mmol) in acetonitrile (CH)₃CN, 80ml) to prepare a mixture. The mixture was heated at 90 ℃ under reflux for 3 days to allow it to react. The reaction product was cooled to room temperature, and then acetonitrile was removed under reduced pressure, thereby obtaining a white viscous solid. 120ml of hexane was added thereto, followed by stirring at room temperature for 1 hour, andthe filtrate was removed using a filter. 120ml of diethyl ether was added thereto, followed by stirring at room temperature for 1 hour, and the filtrate was removed using a filter, whereby 7.9g of a white solid was obtained (yield: 85%).

Step 2

Bis- (2-ethylhexyl) sulfosuccinic acid sodium salt (7.8g, 17.5mmol) was dissolved in water (20ml) and stirred. The N, N-dibenzyl-N, N-tetraethylhexane-1, 6-diammonium bromide (5g, 8.8mmol) synthesized in step 1 was dissolved in ethyl acetate (40ml), and the resulting solution was added to the above sodium salt solution. The resulting mixture was stirred at room temperature overnight and then allowed to stand, after which the aqueous layer was removed. The organic layer was washed twice with water (20ml), and then ethyl acetate was removed under reduced pressure, whereby 10.6g of compound E was obtained as a colorless transparent liquid (yield: 96%).

The NMR data for compound E are as follows.

¹H NMR(500MHz,DMSO-d₆)δ7.25(m,4H),,7.22(m,2H),7.16(m,4H),4.5(s,4H),3.85(m,8H),3.55(q,2H),3.28-3.22(m,12H),2.85(q,2H),2.75(q,2H),1.89(m,4H),1.71(m,4H),,1.55(m,8H),1.31-1.25(m,32H),1.19(m,8H),0.99(m,12H),0.88(m,,12H)

Example 6: synthesis of Compound F (bis (ammonium) cation & alkylphosphate anion)

[ Compound F ]

Step 1

Same as in step 1 of compound E.

Step 2

Bis- (2-ethylhexyl) phosphate (2.0g, 6.3mmol) was dissolved in water (15ml) and stirred. Sodium hydroxide (0.25g, 6.3mmol) was added thereto, and the resulting mixture was stirred at room temperature for 1 hour. The N, N-dibenzyl-N, N-tetraethylhexane-1, 6-diammonium bromide (1.8g, 3.15mmol) synthesized in step 1 was dissolved in ethyl acetate (30ml), and the resulting solution was added to the above sodium salt solution. The resulting mixture was stirred at room temperature overnight and then allowed to stand, after which the aqueous layer was removed. The organic layer was washed twice with water (15ml), and then ethyl acetate was removed under reduced pressure, whereby 3.0g of compound F was obtained as an opaque liquid (yield: 92%).

The NMR data for compound F are as follows.

¹H NMR(500MHz,DMSO-d₆)δ7.25(m,4H),,7.22(m,2H),7.16(m,4H),4.50(s,4H),3.45(m,8H),3.28-3.22(m,12H),1.71(m,4H),1.55(m,8H),1.31-1.19(m,44H),0.99(m,12H),0.88(m,12H)

Example 7: abrasion test

< sample information >

-a reference: engine oil with viscosity grade of 5W-30

-ZDDP (zinc dithiophosphate): conventional additives for reducing wear

-compound a: ionic liquids comprising divalent cations and monovalent anions prepared in example 1

[ Compound A ]

-compound a': ionic liquids comprising monovalent cations and monovalent anions

[ Compound A' ]

< HFRR (high frequency reciprocating rig) test >

The HFRR test was performed on the above samples. The HFRR test was carried out in a ball-and-disc mode for 90min at a load of 500g and a temperature of 100 ℃. After the end of the test, the size of the wear scar was measured using a microscope, and the result thereof is shown in fig. 5.

The same HFRR test was performed at 60 ℃. The results are shown in FIG. 6.

< results >

Referring to fig. 5, a lubricant article comprising an ionic liquid comprising a divalent cation and an anion is effective in reducing wear compared to a reference lubricant article that does not comprise an ionic liquid. Furthermore, lubricant articles using ionic liquids comprising divalent cations and anions exhibit superior friction reducing effects as compared to lubricant articles using ZDDP as a conventional additive for reducing wear.

Referring to fig. 5 and 6, a lubricant article using an ionic liquid including a divalent cation and an anion exhibits an excellent friction reducing effect as compared to a lubricant article using an ionic liquid including a monovalent cation and an anion at both a low temperature of 60 ℃ and a high temperature of 100 ℃.

Although the embodiments of the present disclosure have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the disclosure as disclosed in the accompanying claims.