Compound, corrosion inhibitor and lubricant composition

Abstract

The present application is a compound represented by the following general formula (B1). In addition, the present application is a corrosion inhibitor (B) containing one or more compounds selected from the group consisting of the compounds represented by the following general formula (B1). Furthermore, it is a lubricant composition containing the ionic liquid (A) and the above-mentioned corrosion inhibitor (B). A compound, a corrosion inhibitor, and a lubricant composition containing the corrosion inhibitor, which are excellent in stability under any of a high-vacuum, a low-temperature environment, a high-temperature environment, a normal-temperature, and a normal-pressure environment, are provided. In the above-mentioned general formula (B1), M represents an alkali metal, R B11 represents an alkylene group having 1 to 19 carbon atoms.

Description

Technical Field

[0001] This invention relates to compounds, corrosion inhibitors, and lubricant compositions. Background Technology

[0002] Space differs from Earth's environment in that it lacks an atmosphere and therefore atmospheric pressure, creating a very high vacuum. Furthermore, under such a high vacuum, liquids with high vapor pressure evaporate during use, making long-term operation in space unsuitable. Additionally, unlike Earth's atmosphere, space is subject to greater thermal radiation and heat release from the sun, resulting in a wide temperature range for devices used in space, from below freezing to extremely high temperatures.

[0003] Therefore, since these devices are exposed to harsh environments different from those on Earth, in order for the equipment mounted on these devices to operate smoothly and continuously for a long time, a lubricant composition that can be used even in high vacuum, low temperature environments below freezing point, and high temperature environments of 200 to 300°C is required.

[0004] In addition, the lubricant composition used to lubricate equipment mounted on space devices is required to reduce the coefficient of friction (lubricity) and maintain lubricity for a long time (low volatility). Therefore, the base oil used as its main component is MAC oil (such as tris(2-octyldodecyl)cyclopentane oil, PFAE (perfluoroalkyl ether), etc.) with low vapor pressure.

[0005] However, MAC oil has a low viscosity index, resulting in significant viscosity changes with temperature. Additionally, PFAE oil suffers from insufficient lubrication.

[0006] Therefore, in recent years, research has been conducted on ionic liquids that exhibit low-temperature fluidity, low evaporation under high vacuum, and excellent lubricity as the main component of lubricant compositions for space equipment (see, for example, Patent Document 1).

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent Application Publication No. 2012-36294 Summary of the Invention

[0010] The problem that the invention aims to solve

[0011] However, from the perspective of the reusability of space-use devices, it is required that after being used in the space environment, the aforementioned devices be temporarily returned to Earth for long-term preservation, maintenance, etc., so that they can be used even if they are taken out into the space environment again.

[0012] Therefore, lubricant compositions for space equipment must exhibit excellent stability and low volatility not only in the space environment but also in the atmospheric pressure environment after re-entry to Earth, i.e., at normal temperature and pressure.

[0013] However, while ionic liquids exhibit excellent lubricity in cosmic environments, they readily absorb moisture and oxygen under atmospheric pressure, leading to metal corrosion depending on the material being processed.

[0014] Therefore, corrosion inhibitors that can suppress metal corrosion were studied for ionic liquids.

[0015] However, corrosion inhibitors used in mineral oils and other materials have low solubility in ionic liquids, thus preventing their application in ionic liquids.

[0016] Furthermore, in the technology described in Patent Document 1, fatty acid amine salts are used as rust inhibitors to suppress rust caused by ionic liquids. However, the fatty acid amine salts described in Patent Document 1 have the problem of evaporation at high temperatures.

[0017] The present invention was made in view of the above-mentioned problems, and its objective is to provide a compound, a corrosion inhibitor, and a lubricant composition containing the corrosion inhibitor that exhibits excellent stability under any of the following conditions: high vacuum, low temperature, high temperature, normal temperature, and normal pressure.

[0018] Methods for solving problems

[0019] Through in-depth research, the inventors discovered that specific compounds can solve the above-mentioned problems, thus completing this invention.

[0020] That is, the present invention provides the following [1].

[0021] [1] A compound represented by the following general formula (B1).

[0022] [Chemical Formula 1]

[0023]

[0024] In the above general formula (B1), M represents an alkali metal, R B11 This refers to alkylene groups having 1 to 19 carbon atoms.

[0025] Invention Effects

[0026] According to the present invention, it is possible to provide compounds, corrosion inhibitors, and lubricant compositions containing the corrosion inhibitor that exhibit excellent stability under any of the following conditions: high vacuum, low temperature, high temperature, normal temperature, and normal pressure. Attached Figure Description

[0027] Figure 1 It is the corrosion inhibitor (B1-1) used in Examples 1 and 2. 1 H-NMR spectrum.

[0028] Figure 2 It is the corrosion inhibitor (B1-2) used in Example 3. 1 H-NMR spectrum.

[0029] Figure 3 It is the corrosion inhibitor (B1-3) used in Example 4. 1 H-NMR spectrum.

[0030] Figure 4 It is the corrosion inhibitor (B1-4) used in Example 5. 1 H-NMR spectrum.

[0031] Figure 5 It is the corrosion inhibitor (B1-5) used in Example 6. 1 H-NMR spectrum. Detailed Implementation

[0032] In this specification, the lower and upper limits of the preferred numerical ranges (e.g., the range of content, etc.) can be independently combined. For example, based on the description of a lower limit such as "preferably 10 or more, more preferably 30 or more, and even more preferably 40 or more" and an upper limit such as "preferably 90 or less, more preferably 80 or less, and even more preferably 70 or less," as a preferred range, one could also choose a range combining independently selected lower and upper limits such as "10 or more and 70 or less," "30 or more and 70 or less," or "40 or more and 80 or less." Alternatively, one could choose a range from the same description that specifies only one of the lower or upper limits, such as "40 or more" or "70 or less." The same applies to preferred ranges that can be selected from descriptions such as "preferably 10 or more and 90 or less, more preferably 30 or more and 80 or less, and even more preferably 40 or more and 70 or less," or "preferably 10 to 90, more preferably 30 to 80, and even more preferably 40 to 70." It should be noted that in this specification, the descriptions of numerical ranges, such as "10 to 90," have the same meaning as "10 or more and 90 or less." It should also be noted that the values ​​used for "above," "below," "less than," and "greater than" related to the descriptions of numerical ranges can be combined arbitrarily.

[0033] It should be noted that, in this specification, for example, "(meth)acrylate" is used as a term referring to both "acrylate" and "methacrylate", and the same applies to other similar terms and designations.

[0034] The compound used in this embodiment is the compound represented by the following general formula (B1).

[0035] [Chemical Formula 2]

[0036]

[0037] In the above general formula (B1), M represents an alkali metal, R B11 This refers to alkylene groups having 1 to 19 carbon atoms.

[0038] In order to solve the above problems, the inventors conducted in-depth research and found that by preparing compounds having the same type of cation and anion structures as ionic liquids and having alkyl carboxylic acid metal salts in the side chains of the cations, it is possible to balance solubility in ionic liquids, resistance to metal corrosion and stability under high temperature environments.

[0039] Based on these insights, the inventors conducted further and in-depth research, thereby completing this invention.

[0040] [Compound]

[0041] The compound used in this embodiment is the compound represented by the following general formula (B1).

[0042] [Chemical Formula 3]

[0043]

[0044] In the above general formula (B1), M represents an alkali metal, R B11 This refers to alkylene groups having 1 to 19 carbon atoms.

[0045] Examples of alkali metals that can be represented as M in the above general formula (B1) include sodium and potassium. Among them, sodium is preferred from the viewpoint that when the temperature is increased from 20°C at a rate of 10°C / min under nitrogen atmosphere using a differential thermal analysis device at normal pressure, the temperature becomes higher than the temperature at which the initial mass decreases by 5% (5% mass reduction temperature), thus ensuring stability even at high temperatures.

[0046] R in the above general formula (B1) B11 R represents an alkylene group having 1 to 19 carbon atoms. This alkylene group can be straight-chain or branched. B11 The number of carbon atoms is preferably 3 to 17, more preferably 5 to 15, even more preferably 7 to 12, and even more preferably 8 to 10. If R B11If the number of carbon atoms is within the above range, it can be applied to a wide range of fields such as lubricant compositions and grease compositions. Additionally, if R... B11 If R has 5 or more carbon atoms, its solubility in ionic liquids is easily improved. Furthermore, if R... B11 If the number of carbon atoms is 8 or more, the resistance to metal corrosion is easily improved. Additionally, if R... B11 If the number of carbon atoms is less than 15, it is easy to increase the mass by 5% and reduce the temperature, which can easily improve the stability under high temperature conditions.

[0047] The compound represented by the above general formula (B1) can be synthesized, for example, by the following synthetic methods.

[0048] First, add N-methylpyrrolidine and Br-R to a 300mL flask. B11 -COO-C2H5(R B11 A compound represented by an alkylene group having 1 to 19 carbon atoms, isopropanol, is reacted at 50°C to 70°C for 7 to 9 hours. Ethyl acetate is added to the reaction mixture, and the precipitate is washed several times with hexane and dried under vacuum for several hours to obtain a white solid. The obtained white solid is diluted in dichloromethane, and lithium bis(trifluoromethanesulfonyl)amide and water are added, and the mixture is reacted at 10°C to 30°C for 0.5 to 2 hours. Next, the organic layer is separated, washed several times with water, and concentrated using an evaporator to obtain the reaction product. Methanol, water, and an alkali metal hydroxide are added to the obtained reaction product, and the mixture is reacted at 90°C to 110°C for 0.5 to 2 hours. The reaction mixture is then concentrated using an evaporator to obtain the compound represented by the above general formula (B1).

[0049] In addition, the compound represented by the above general formula (B1) can, for example, be used... 1 The H-NMR method was used for structural analysis under the conditions described in the examples.

[0050] [Stability under high temperature conditions (5% mass loss temperature)]

[0051] The 5% mass reduction temperature of the compound represented by the above general formula (B1) is preferably 270°C or higher, more preferably 300°C or higher, and even more preferably 310°C or higher. Therefore, it exhibits excellent stability even at high temperatures.

[0052] The 5% mass reduction temperature can be determined using the method described in the examples.

[0053] Corrosion Inhibitor (B)

[0054] The compound represented by the above general formula (B1) has excellent resistance to metal corrosion, so it can be used as a corrosion inhibitor (B) in the lubricant composition described later.

[0055] As a corrosion inhibitor (B), it comprises one or more compounds selected from the compounds shown in the above general formula (B1).

[0056] The content of the compound represented by the general formula (B1), based on the total amount of corrosion inhibitor (B), is preferably 60% to 100% by mass, more preferably 70% to 100% by mass, and even more preferably 80% to 100% by mass.

[0057] [Lubricant Composition]

[0058] The lubricant composition of this embodiment comprises an ionic liquid (A) and a corrosion inhibitor (B), wherein the corrosion inhibitor (B) comprises one or more compounds selected from those shown in the above general formula (B1).

[0059] It should be noted that in the following description, ionic liquid (A) and corrosion inhibitor (B) will also be referred to as component (A) and component (B), respectively.

[0060] In the lubricant composition of this embodiment, the total content of component (A) and component (B) is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and even more preferably 95% by mass or more.

[0061] Furthermore, in the lubricant composition of this embodiment, the upper limit of the total content of component (A) and component (B) can be 100% by mass. Wherein, when the lubricant composition contains other components besides component (A) and component (B), the upper limit of the total content of component (A) and component (B) can be adjusted according to the relationship with other components, preferably 99% by mass or less, more preferably 98% by mass or less.

[0062] In the lubricant composition of this embodiment, from the viewpoint of more easily exerting the effects of solubility in ionic liquid (A) and resistance to metal corrosion, the content of the compound represented by the above general formula (B1) is preferably 0.01% by mass or more and 10% by mass or less, more preferably 0.1% by mass or more and 10% by mass or less, further preferably 0.1% by mass or more and 5.0% by mass or less, even more preferably 1.0% by mass or more and 3.0% by mass or less, and even more preferably 1.5% by mass or more and 2.5% by mass or less.

[0063] Furthermore, in the lubricant composition of this embodiment, from the viewpoint of more easily exerting the effects of solubility in the ionic liquid (A) and resistance to metal corrosion, the content of corrosion inhibitor (B) is preferably 0.01% by mass or more and 10% by mass or less, more preferably 0.1% by mass or more and 10% by mass or less, further preferably 0.1% by mass or more and 5.0% by mass or less, even more preferably 1.0% by mass or more and 3.0% by mass or less, and even more preferably 1.5% by mass or more and 2.5% by mass or less.

[0064] It should be noted that corrosion inhibitor (B) can be used alone or in combination of two or more. When using two or more, the preferred total content is the same as the content mentioned above.

[0065] The components contained in the lubricant composition of this embodiment will be described below.

[0066] <Ionic Liquid (A)>

[0067] The lubricant composition of this embodiment contains an ionic liquid (A).

[0068] Ionic liquids (A) are liquid compounds composed of cations and anions.

[0069] The anion of the ionic liquid (A) preferably contains bis(trifluoromethanesulfonyl)amide.

[0070] The cation of the ionic liquid (A) preferably includes the cation represented by the following general formula (A1).

[0071] [Chemical Formula 4]

[0072]

[0073] In the above general formula (A1), n ​​is 1 or 2, X is methylene or oxygen, and R A11 R A12 Each group is independently selected from alkyl groups having 1 to 12 carbon atoms, which may be ether, ester, nitrile, or silyl.

[0074] From the perspective of reducing the viscosity of ionic liquids and improving their stability under high-temperature environments, R in the general formula (A1) A11 R A12 The alkyl group preferably has 1 to 6 carbon atoms, more preferably 1 to 4.

[0075] As R A11 Methyl group is preferred. Additionally, as R... A12 Preferred are n-butyl and methoxyethyl.

[0076] Examples of cations represented by the above general formula (A1) include 1-butyl-1-methylpyrrolidineonium, 1-pentyl-1-methylpyrrolidineonium, 1-hexyl-1-methylpyrrolidineonium, 1-heptyl-1-methylpyrrolidineonium, 1-octyl-1-methylpyrrolidineonium, 1-nonyl-1-methylpyrrolidineonium, 1-decyl-1-methylpyrrolidineonium, 1-undecyl-1-methylpyrrolidineonium, 1-dodecyl-1-methylpyrrolidineonium, 1-methoxymethyl-1-methylpyrrolidineonium, 1-( 2-Methoxyethyl)-1-methylpyrrolidineonium, 1-(2-methoxy-2-oxoethyl)-1-methylpyrrolidineonium, 1-cyanomethyl-1-methylpyrrolidineonium, 1-trimethylsilylmethyl-1-methylpyrrolidineonium, 1-butyl-1-methylpiperidineonium, 1-pentyl-1-methylpiperidineonium, 1-hexyl-1-methylpiperidineonium, 1-heptyl-1-methylpiperidineonium, 1-octyl-1-methylpiperidineonium, 1-nonyl-1-methylpiperidineonium, 1-decyl-1-methylpiperidineonium, 1-Undecyl-1-methylpiperidinium, 1-Dodecyl-1-methylpiperidinium, 1-Methoxymethyl-1-methylpiperidinium, 1-(2-Methoxyethyl)-1-methylpiperidinium, 1-(2-Methoxy-2-oxoethyl)-1-methylpiperidinium, 1-Cyanomethyl-1-methylpiperidinium, 1-Trimethylsilylmethyl-1-methylpiperidinium, 1-Butyl-1-methylmorpholinium, 1-Pentyl-1-methylmorpholinium, 1-Hexyl-1-methylmorpholinium, 1-Heptyl-1- Methylmorpholinium, 1-octyl-1-methylmorpholinium, 1-nonyl-1-methylmorpholinium, 1-decyl-1-methylmorpholinium, 1-undecyl-1-methylmorpholinium, 1-dodecyl-1-methylmorpholinium, 1-(2-methoxyethyl)-1-methylmorpholinium, 1-methoxymethyl-1-methylmorpholinium, 1-(2-methoxy-2-oxoethyl)-1-methylmorpholinium, 1-cyanomethyl-1-methylmorpholinium, 1-trimethylsilylmethyl-1-methylmorpholinium, etc.

[0077] From the viewpoint of reducing the viscosity of the ionic liquid (A) and improving its stability under high-temperature conditions, 1-butyl-1-methylpyrrolidineonium, 1-pentyl-1-methylpyrrolidineonium, 1-hexyl-1-methylpyrrolidineonium, 1-(2-methoxyethyl)-1-methylpyrrolidineonium, 1-butyl-1-methylpiperidineonium, 1-(2-methoxyethyl)-1-methylpiperidineonium, and 1-(2-methoxyethyl)-1-methylmorpholinonium are preferred, 1-butyl-1-methylpyrrolidineonium, 1-(2-methoxyethyl)-1-methylpyrrolidineonium, and 1-(2-methoxyethyl)-1-methylpiperidineonium are even more preferred, and 1-butyl-1-methylpyrrolidineonium and 1-(2-methoxyethyl)-1-methylpiperidineonium are even more preferred.

[0078] As an ionic liquid (A), it preferably contains at least one compound selected from the compounds shown in the following general formula (A2) and the following general formula (A3).

[0079] [Chemical Formula 5]

[0080]

[0081] In the above general formula (A2), n is 1 or 2, X is methylene or oxygen, and R A21 This refers to alkyl groups having 2 to 12 carbon atoms.

[0082] [Chemical Formula 6]

[0083]

[0084] In the above general formula (A3), n is 1 or 2, X is methylene or oxygen, and R A31 R represents an alkylene group having 1 to 5 carbon atoms. A32 This refers to an alkyl group having 1 to 3 hydrogen atoms or carbon atoms.

[0085] In the above general formula (A2), R A21 The number of carbon atoms is preferably 2 to 8, more preferably 3 to 6. If R A21 If R has two or more carbon atoms, the side chains can move freely, and the symmetry decreases, thus suppressing crystallization and improving its function as an ionic liquid. A21 If the number of carbon atoms is less than 12, the side chains will not become too large, and the overall ionicity of the compound is high, thus making it easy to suppress oxidative degradation.

[0086] In the above general formula (A3), R A31 The number of carbon atoms is preferably 1 to 3, more preferably 1 to 2. Additionally, R A32 The preferred number of carbon atoms is 1 to 2. If R A31 If R has one or more carbon atoms, the side chains can move freely, and the symmetry decreases, thus suppressing crystallization and improving its function as an ionic liquid. A31 The number of carbon atoms is 5 or less, or R A32 If the number of carbon atoms is 3 or less, the side chains will not become too large, and the overall ionicity of the compound is high, thus making it easy to suppress oxidative degradation.

[0087] The content of the compound represented by the general formula (A2) is preferably 60% to 100% by mass, more preferably 70% to 100% by mass, and even more preferably 80% to 100% by mass, based on the total amount of ionic liquid (A).

[0088] Furthermore, the content of the compound represented by the general formula (A3) is preferably 60% to 100% by mass, more preferably 70% to 100% by mass, and even more preferably 80% to 100% by mass, based on the total amount of the ionic liquid (A).

[0089] From the viewpoint of low evaporation and suppression of dynamic losses caused by viscous resistance, the kinematic viscosity of the ionic liquid (A) at 40°C is preferably 2.0 mm. 2 / s~100.0mm 2 / s, more preferably 10.0mm 2 / s~70.0mm 2 / s, further preferably 20.0mm 2 / s~40.0mm 2 / s.

[0090] From the viewpoint of low evaporation and suppression of dynamic losses caused by viscous resistance, the kinematic viscosity of the ionic liquid (A) at 100°C is preferably 1.0 mm. 2 / s~20.0mm 2 / s, more preferably 2.0mm 2 / s~10.0mm 2 / s, further preferably 3.0mm 2 / s~7.0mm 2 / s.

[0091] From the viewpoint of reducing viscosity changes even when used in low-temperature, high-temperature environments and in space environments with large temperature variations, the viscosity index of the ionic liquid (A) is preferably 100 or higher, more preferably 120 or higher, and even more preferably 140 or higher.

[0092] The above-mentioned kinematic viscosity at 40℃, kinematic viscosity at 100℃, and viscosity index can be determined or calculated according to JIS K 2283:2000.

[0093] Furthermore, when the ionic liquid (A) is a mixture of two or more ionic liquids, the kinematic viscosity and viscosity index of the mixture are preferably within the ranges described above.

[0094] From the viewpoint of suppressing the increase of viscous resistance at low temperatures, the pour point of the ionic liquid (A) is preferably below 0°C, more preferably below -10°C, and even more preferably below -20°C.

[0095] The pour point of ionic liquid (A) can be determined according to JIS K 2269:1987.

[0096] From the viewpoint of resistance to metal corrosion, the acid value of the above-mentioned ionic liquid (A) is preferably 1 mg KOH / g or less, more preferably 0.5 mg KOH / g or less, and even more preferably 0.3 mg KOH / g or less.

[0097] From the viewpoint of low evaporability, the flash point of the above-mentioned ionic liquid (A) is preferably 200 or higher, more preferably 250 or higher, and even more preferably 300 or higher.

[0098] The preferred ion concentration for ionic liquid (A) measured at 15°C is 1.0 mol / dm³. 3 The above, more preferably 1.5 mol / dm 3 The above is further preferred to be 2.0 mol / dm 3 above.

[0099] Here, ion concentration refers to the density (g / cm³) in an ionic liquid as measured at 15°C. 3 The value is calculated as [(molecular weight Mw (g / mol))] × 1000. If the ion concentration of ionic liquid (A) is 1.0 mol / dm³... 3 The above can further improve stability under low evaporation and high temperature environments.

[0100] The molecular weight of the ionic liquid (A) is preferably 410 or more and 570 or less, more preferably 410 or more and 470 or less, and even more preferably 420 or more and 440 or less. If the molecular weight of the ionic liquid (A) is within the above range, the charge density and the length of the alkyl chain of the cation are within an appropriate range, which enables the ionic liquid to achieve low viscosity and improved stability under high temperature conditions.

[0101] In the lubricant composition of this embodiment, the content of ionic liquid (A) is not particularly limited. From the viewpoint of more easily exerting the effect of the present invention, based on the total amount of the lubricant composition (100% by mass), it is preferably 60% to 99.5% by mass, more preferably 70% to 99.0% by mass, and even more preferably 80% to 98.5% by mass.

[0102] The lubricant composition of this embodiment may contain other components besides the ionic liquid (A) (e.g., ethyl acetate). From the viewpoint of maximizing the effects of the present invention, the content of the ionic liquid (A) is preferably 50% by mass or more, more preferably 70% by mass or more, further preferably 90% by mass or more, and even more preferably 100% by mass, based on the total amount of ionic liquid.

[0103] The ratio (B1 / A) of the content of the compound represented by the above general formula (B1) to the content of the above ionic liquid (A) is preferably 0.0005 or more and 0.15 or less by mass, more preferably 0.001 or more and 0.111 or less, and even more preferably 0.005 or more and 0.08 or less. If (B1 / A) is 0.0005 or more, sufficient resistance to metal corrosion is easily achieved. If (B1 / A) is 0.15 or less, sufficient solubility in the ionic liquid (A) is easily achieved.

[0104] <Other Ingredients>

[0105] The lubricant composition of this embodiment may contain other components besides those described above, as needed, without impairing the effects of the present invention.

[0106] Other components mentioned above include, for example, viscosity index improvers.

[0107] They can be used individually or in combination of two or more.

[0108] -Viscosity index improver-

[0109] By including a viscosity index improver in the lubricant composition of this embodiment, the viscosity index of the lubricant composition can be increased. Therefore, viscosity changes can be reduced even when used in low-temperature, high-temperature environments and in space environments with large temperature variations.

[0110] Examples of viscosity index improvers include those that are soluble in ionic liquids and are used for polymers such as non-dispersed poly(meth)acrylates and dispersed poly(meth)acrylates.

[0111] They can be used individually or in combination of two or more.

[0112] The mass-average molecular weight (Mw) of these viscosity index improvers is typically 5,000 to 1,000,000, preferably 6,000 to 100,000, more preferably 10,000 to 50,000, and can be appropriately set according to the type of polymer.

[0113] In this specification, the mass-average molecular weight (Mw) of each component is a value converted from standard polystyrene determined by gel permeation chromatography (GPC).

[0114] The content of the other components mentioned above can be appropriately adjusted within the range without impairing the effect of the present invention. For each component, the content is generally 0.001% to 15% by mass based on the total amount (100% by mass) of the lubricant composition, preferably 0.005% to 10% by mass, more preferably 0.01% to 7% by mass, and even more preferably 0.03% to 5% by mass.

[0115] It should be noted that, in this specification, considering factors such as processability and solubility in the ionic liquid (A), the additives described above as other components may be combined with other components in the form of a solution obtained by diluting and dissolving a portion of the ionic liquid (A). In this case, the content of the additives described above as other components in this specification refers to the content calculated based on the effective component (resin component conversion) excluding the diluent.

[0116] [Physical properties of the lubricant composition]

[0117] <Kinematic viscosity at 40℃, kinematic viscosity at 100℃, and viscosity index>

[0118] From the viewpoint of low evaporation and suppression of dynamic loss due to viscous resistance, the kinematic viscosity of the lubricant composition in this embodiment at 40°C is preferably 2.0 mm. 2 / s~100.0mm 2 / s, more preferably 10.0mm 2 / s~70.0mm 2 / s, further preferably 20.0mm 2 / s~50.0mm 2 / s.

[0119] From the viewpoint of low evaporation and suppression of dynamic loss caused by viscous resistance, the kinematic viscosity of the lubricant composition in this embodiment at 100°C is preferably 1.0 mm. 2 / s~20.0mm 2 / s, more preferably 2.0mm 2 / s~15.0mm 2 / s, further preferably 3.0mm 2 / s~10.0mm 2 / s.

[0120] From the viewpoint of minimizing viscosity changes even when used in low-temperature, high-temperature environments and in space environments with large temperature variations, the viscosity index of the lubricant composition of this embodiment is preferably 100 or more, more preferably 120 or more, and even more preferably 140 or more.

[0121] The above-mentioned kinematic viscosity at 40℃, kinematic viscosity at 100℃, and viscosity index can be determined or calculated according to JIS K 2283:2000.

[0122] <Solubility (Appearance)>

[0123] The preferred corrosion inhibitor (B) dissolves in the ionic liquid (A) to become colorless and transparent. It should be noted that the determination can be made using the methods described in the examples.

[0124] Low volatility (evaporation rate)

[0125] The evaporation amount is preferably less than 0.1% by mass. It should be noted that the measurement can be performed using the method described in the examples.

[0126] <Resistance to metal corrosion>

[0127] Regarding resistance to metal corrosion, when judged by the method described in the examples, it is preferable that no corrosion is observed.

[0128] [Uses of Lubricant Compositions]

[0129] The lubricant composition of this embodiment exhibits excellent resistance to metal corrosion, solubility, and low volatility not only under high vacuum, low temperature, and high temperature conditions, but also under normal temperature and pressure conditions. Therefore, it is suitable for use in machines mounted on devices used in space, such as artificial satellites, probes, and lunar rovers. Furthermore, the lubricant composition of this embodiment performs excellently under high vacuum conditions, making it suitable for use in manufacturing apparatuses for semiconductors, liquid crystals, organic EL flat panel displays, solar cell panels, and the like.

[0130] It should be noted that the lubricant composition of this embodiment is suitable for use as a lubricant composition for devices used in space, but it can also be applied to other uses.

[0131] [Method for manufacturing lubricant composition]

[0132] As an embodiment of this invention, a method for manufacturing a lubricant composition is provided, which includes a step of mixing an ionic liquid (A) with a compound represented by the following general formula (B1).

[0133] [Chemical Formula 7]

[0134]

[0135] In the above general formula (B1), M represents an alkali metal, R B11 This refers to alkylene groups having 1 to 19 carbon atoms.

[0136] There are no particular limitations on the method of mixing the above components. For example, a process of mixing is carried out by adding the compound shown in the following general formula (B1) to the ionic liquid (A).

[0137] In addition, the above manufacturing method may further include the step of adding the other components mentioned above.

[0138] [Lubricating Grease Composition]

[0139] The lubricant composition of this embodiment can also be used as a grease composition by including an ionic liquid (A), a corrosion inhibitor (B), and a thickener.

[0140] Because outer space is a microgravity environment, the gravity-based lubricant supply methods commonly used on Earth cannot be applied. However, by applying the lubricant composition of this embodiment to a grease composition, lubricity can be maintained even when no lubricant is supplied during use.

[0141] Cellulose nanofibers are preferably used as a thickener in the above-mentioned grease composition. Both the ionic liquid (A) and the cellulose nanofibers are hydrophilic, thus allowing for good affinity retention of the ionic liquid (A) and the corrosion inhibitor (B) within the cellulose nanofibers.

[0142] It should be noted that the above-mentioned grease composition may contain other components besides component (A) and component (B) without impairing the effect of the present invention.

[0143] <Nanofibers>

[0144] The nanofibers contained in the grease composition of this embodiment are preferably selected from one or more of cellulose nanofibers and hydrophilic modified cellulose nanofibers.

[0145] By incorporating nanofibers into the grease composition, the nanofibers are uniformly dispersed within the composition, forming a high-order structure. The nanofibers exhibit excellent mechanical stability, thus the high-order structure based on the nanofibers enhances shear stability. Consequently, the shear stability of the grease composition is improved, and the grease's anti-leakage performance is enhanced.

[0146] Furthermore, even with a small amount of nanofibers, the proportion of ionic liquid (A) in the grease composition can be increased by adjusting the working cone penetration of the grease composition to an appropriate range. Therefore, the lubricity of the grease composition is improved, and its wear resistance is also easily enhanced.

[0147] (cellulose nanofibers)

[0148] Cellulose nanofibers are fibrous materials with a thickness of less than 500 nm, which are produced by splitting plant fibers to the nanoscale. They are distinct from sheet-like, powder-like, and particle-like materials.

[0149] It should be noted that lignocellulose can also be used as a raw material for cellulose nanofibers. Lignocellulose is a complex hydrocarbon polymer that makes up the cell walls of plants, and is known to be mainly composed of polysaccharides such as cellulose and hemicellulose, and aromatic polymers such as lignin.

[0150] The cellulose constituting the cellulose nanofibers can be one or more selected from lignocellulose and acetylated lignocellulose. Additionally, the cellulose nanofibers can contain one or more selected from hemicellulose and lignin. Furthermore, the cellulose constituting the cellulose nanofibers can be chemically bonded to one or more selected from hemicellulose and lignin.

[0151] The degree of polymerization of cellulose constituting cellulose nanofibers is preferably 50 to 3000, more preferably 100 to 1500, even more preferably 150 to 1000, and even more preferably 200 to 800.

[0152] It should be noted that, in this specification, the degree of polymerization of cellulose refers to the value determined by the viscosity method.

[0153] (Hydrophilic modified cellulose nanofibers)

[0154] Hydrophilic modified cellulose nanofibers are obtained by modifying cellulose nanofibers within a range that maintains their hydrophilicity.

[0155] Specific examples of modification treatments include esterification such as acetylation, phosphorylation, carbamate esterification, ureation, etherification, carboxymethylation, TEMPO (2,2,6,6-tetramethylpiperidine-1-oxy radical) oxidation, and periodic acid oxidation.

[0156] The modified cellulose nanofibers used in this invention may be modified cellulose nanofibers obtained by performing only one of these modification treatments, or modified cellulose nanofibers obtained by performing two or more of these modification treatments.

[0157] According to one aspect of the present invention, the following [1] to [7] are provided.

[0158] [1] A compound represented by the following general formula (B1).

[0159] [Chemical Formula 8]

[0160]

[0161] In the above general formula (B1), M represents an alkali metal, R B11This refers to alkylene groups having 1 to 19 carbon atoms.

[0162] [2] A corrosion inhibitor comprising one or more compounds selected from [1] above.

[0163] [3] A lubricant composition comprising an ionic liquid (A) and the corrosion inhibitor described above [2] (B).

[0164] [4] According to the lubricant composition described in [3] above, wherein the ionic liquid (A) contains a cation represented by the following general formula (A1).

[0165] [Chemical Formula 9]

[0166]

[0167] In the above general formula (A1), n ​​is 1 or 2, X is methylene or oxygen, and R A11 R A12 Each group is independently selected from alkyl groups having 1 to 12 carbon atoms, which may be ether, ester, nitrile, or silyl.

[0168] [5] The lubricant composition according to [3] or [4] above, wherein the ionic liquid (A) comprises at least one selected from the compounds shown in the following general formula (A2) and the compounds shown in the following general formula (A3).

[0169] [Chemical Formula 10]

[0170]

[0171] In the above general formula (A2), n is 1 or 2, X is methylene or oxygen, and R A21 This refers to alkyl groups having 2 to 12 carbon atoms.

[0172] [Chemical Formula 11]

[0173]

[0174] In the above general formula (A3), n is 1 or 2, X is methylene or oxygen, and R A31 R represents an alkylene group having 1 to 5 carbon atoms. A32 This refers to an alkyl group having 1 to 3 hydrogen atoms or carbon atoms.

[0175] [6] The lubricant composition according to any one of [3] to [5] above, wherein the content of the compound represented by the above general formula (B1) is 0.1% by mass or more and 10% by mass or less based on the total amount of the above lubricant composition.

[0176] [7] The lubricant composition according to any one of [3] to [6] above, wherein the ratio (B1 / A) of the content of the compound represented by the above general formula (B1) to the content of the above ionic liquid (A) is 0.0005 or more and 0.15 or less by mass.

[0177] Example

[0178] The present invention will be specifically described through the following embodiments, but the present invention is not limited to the following embodiments.

[0179] The structures of the corrosion inhibitors described below were determined using the following methods.

[0180] [NMR Structure Analysis]

[0181] For the corrosion inhibitors (B1-1) to (B1-5) described later, use 1 The 1H-NMR method was performed under the following conditions. The obtained... 1 The H-NMR spectrum is shown in Figures 1-5 .

[0182] Device Name: JNM-ECZ400S (Manufactured by Nippon Electronics Co., Ltd.)

[0183] • Measurement temperature: 20℃

[0184] • Reference material: DMSO-D6

[0185] [Synthesis and Acquisition of Corrosion Inhibitor (B)]

[0186] Corrosion inhibitors (B1-1) to (B1-5) and corrosion inhibitor (B2-2) were synthesized using the methods described later. Corrosion inhibitors (B2-1) and (B2-3) were also obtained.

[0187] Corrosion Inhibitor (B1-1)

[0188] Corrosion inhibitor (B1-1)

[0189] First, N-methylpyrrolidine (2.44 g, 28.6 mmol), ethyl 10-bromodecanoate (8.80 g, 31.5 mmol), and 20 mL of isopropanol were added to a 300 mL flask, and the mixture was reacted at 60 °C for 8 hours. Then, 100 mL of ethyl acetate was added to the reaction mixture, and the precipitate was washed several times with hexane and dried under vacuum for several hours to obtain 9.5 g of a white solid. The obtained white solid was diluted in 100 mL of dichloromethane, and lithium bis(trifluoromethanesulfonyl)amide (8.21 g, 28.6 mmol) and 100 mL of water were added. The mixture was reacted at 20 °C for 1 hour. Next, the organic layer was separated, washed several times with water, and concentrated using an evaporator to obtain 14.1 g of the reaction product. Then, 16 mL of methanol, 2 mL of water, and sodium hydroxide (1.00 g, 25.0 mmol) were added to the obtained reaction product, and the mixture was reacted at 100 °C for 1 hour. The reaction mixture was then concentrated using an evaporator to obtain the corrosion inhibitor (B1-1).

[0190] The obtained corrosion inhibitor (B1-1) weighed 13.57 g and had a mass of 24.3 mmol. Furthermore, the 5% mass reduction temperature of the obtained corrosion inhibitor (B1-1) was 317 °C. The structure of the corrosion inhibitor (B1-1) is shown in structural formula (B1-1).

[0191] [Chemical Formula 12]

[0192]

[0193] Corrosion Inhibitor (B1-2)

[0194] Corrosion inhibitor (B1-2)

[0195] In the synthesis of corrosion inhibitor (B1-1), ethyl 11-bromoundecanoate (9.24 g, 31.5 mmol) was used instead of ethyl 10-bromodecanoate. Otherwise, corrosion inhibitor (B1-2) was synthesized using the same method.

[0196] The obtained corrosion inhibitor (B1-2) weighed 13.63 g and had a mass of 23.8 mmol. Furthermore, the 5% mass reduction temperature of the obtained corrosion inhibitor (B1-2) was 314 °C. The structure of the corrosion inhibitor (B1-2) is shown in structural formula (B1-2).

[0197] [Chemical Formula 13]

[0198]

[0199] Corrosion Inhibitor (B1-3)

[0200] Corrosion inhibitors (B1-3)

[0201] In the synthesis of corrosion inhibitor (B1-1), potassium hydroxide (1.40 g, 25.0 mmol) was used instead of sodium hydroxide. Otherwise, the same method was used to synthesize corrosion inhibitor (B1-3).

[0202] The obtained corrosion inhibitor (B1-3) weighed 13.51 g and produced 23.5 mmol. Furthermore, the 5% mass reduction temperature of the obtained corrosion inhibitor (B1-3) was 280 °C. The structure of the corrosion inhibitor (B1-3) is shown in structural formula (B1-3).

[0203] [Chemical Formula 14]

[0204]

[0205] Corrosion Inhibitor (B1-4)

[0206] Corrosion inhibitors (B1-4)

[0207] In the synthesis of corrosion inhibitor (B1-1), ethyl 6-bromohexanoate (7.03 g, 31.5 mmol) was used instead of ethyl 10-bromodecanoate. Otherwise, the same method was used to synthesize corrosion inhibitor (B1-4).

[0208] The obtained corrosion inhibitor (B1-4) weighed 12.57 g and produced 25.0 mmol. Furthermore, the 5% mass reduction temperature of the obtained corrosion inhibitor (B1-4) was 291 °C. The structure of the corrosion inhibitor (B1-4) is shown in structural formula (B1-4).

[0209] [Chemical Formula 15]

[0210]

[0211] Corrosion Inhibitor (B1-5)

[0212] Corrosion inhibitors (B1-5)

[0213] In the synthesis of corrosion inhibitor (B1-1), ethyl 8-bromooctanoate (7.91 g, 31.5 mmol) was used instead of ethyl 10-bromodecanoate. Otherwise, the same method was used to synthesize corrosion inhibitor (B1-5).

[0214] The obtained corrosion inhibitor (B1-5) weighed 13.16 g and had a mass of 24.8 mmol. Furthermore, the 5% mass reduction temperature of the obtained corrosion inhibitor (B1-5) was 318 °C. The structure of the corrosion inhibitor (B1-5) is shown in structural formula (B1-5).

[0215] [Chemical Formula 16]

[0216]

[0217] Corrosion Inhibitor (B2-1)

[0218] Corrosion inhibitor (B2-1): Disodium sebate

[0219] Sodium sebacic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) was obtained and used as a corrosion inhibitor (B2-1).

[0220] The corrosion inhibitor (B2-1) has a 5% mass reduction temperature of 381°C. The structure of the corrosion inhibitor (B2-1) is shown in structural formula (B2-1).

[0221] [Chemical Formula 17]

[0222] NaO2C-(CH2)8-CO2Na···Structural formula (B2-1)

[0223] Corrosion Inhibitor (B2-2)

[0224] Corrosion inhibitor (B2-2): Bis(tetramethylammonium sebacate)

[0225] Sebacic acid (27.7 g, 0.137 mol) and tetramethylammonium hydroxide (approximately 25% aqueous solution, 100 g, 0.274 mol) were added to a 500 mL flask, and the mixture was reacted at room temperature (20 °C) for 1 hour. The reaction mixture was concentrated using a rotary evaporator, and the resulting solid was dried under vacuum for several hours to obtain the corrosion inhibitor (B2-2).

[0226] The obtained corrosion inhibitor (B2-2) was 47.4 g, or 0.136 mol. Furthermore, the 5% mass reduction temperature of the obtained corrosion inhibitor (B2-2) was 200 °C. The structure of the corrosion inhibitor (B2-2) is shown in structural formula (B2-2).

[0227] [Chemical Formula 18]

[0228]

[0229] Corrosion Inhibitor (B2-3)

[0230] Corrosion inhibitor (B2-3)

[0231] The product name obtained is Chellesuito T (manufactured by CHELEST Co., Ltd.), used as a corrosion inhibitor (B2-3). The corrosion inhibitor (B2-3) has a 5% mass reduction temperature of 130°C.

[0232] The obtained corrosion inhibitors were evaluated as follows. The results are shown in Table 1.

[0233] [Stability evaluation under high temperature conditions (5% mass loss temperature)]

[0234] For each compound of corrosion inhibitors (B1-1) to (B1-5) and corrosion inhibitors (B2-1) to (B2-3), a differential calorimeter was used under normal pressure to increase the temperature from 20°C at a rate of 10°C / min in a nitrogen atmosphere, and the temperature at which the initial mass decreased by 5% (5% mass reduction temperature) was determined.

[0235] [Table 1]

[0236] Table 1

[0237] Corrosion inhibitors 5% mass reduction temperature (°C) Corrosion inhibitor (B1-1) 317 Corrosion inhibitor (B1-2) 314 Corrosion inhibitor (B1-3) 280 Corrosion inhibitors (B1-4) 291 Corrosion inhibitor (B1-5) 318 Corrosion inhibitor (B2-1) 381 Corrosion inhibitor (B2-2) 200 Corrosion inhibitor (B2-3) 130

[0238] As shown in Table 1, the corrosion inhibitors (B1-1) to (B1-5) that satisfy all the components of this invention have a sufficiently high 5% mass reduction temperature of 270°C or higher, and are stable even in high-temperature environments.

[0239] On the other hand, the 5% mass reduction temperature of corrosion inhibitor (B2-1) is above 270°C, but the 5% mass reduction temperature of corrosion inhibitors (B2-2) to (B2-3) is as low as less than 270°C. Therefore, corrosion inhibitors (B2-2) to (B2-3) may not be suitable for use in the high-temperature environment of space.

[0240] Next, using the corrosion inhibitors (B1-1) to (B1-5) and corrosion inhibitors (B2-1) to (B2-3) described above, a lubricant composition is prepared by the method described later.

[0241] It should be noted that the physical properties of each lubricant composition are determined or calculated by the following methods.

[0242] [Kinematic viscosity at 40°C, kinematic viscosity at 100°C, and viscosity index]

[0243] Determine or calculate the kinematic viscosity at 40°C, kinematic viscosity at 100°C, and viscosity index of the lubricant composition and ionic liquid (A) according to JIS K 2283:2000.

[0244] [Pour Point]

[0245] The pour point of ionic liquid (A) was determined according to JIS K2269:1987.

[0246] [density]

[0247] The density of ionic liquid (A) at 15 °C was determined according to JIS K 2249-1:2011.

[0248] [5% mass reduction at temperature]

[0249] For ionic liquids (A-1) to (A-2), operate in the same manner as the corrosion inhibitors described above, and determine the temperature at which the initial mass decreases by 5% (5% mass reduction temperature).

[0250] [Synthesis of ionic liquid (A)]

[0251] Ionic liquids (A-1) to (A-2) were synthesized by the method described later.

[0252] <Ionic Liquid (A-1)>

[0253] • Ionic liquid (A-1): 1-Butyl-1-methylpyrrolidone-bis(trifluoromethanesulfonyl)amide

[0254] 1-Methylpyrrolidine (50 g, 0.587 mol) and 2-propanol (70 mL) were added to a 1 L flask under a nitrogen atmosphere. 1-Bromobutane (96 g, 0.704 mol) was then added dropwise, and the mixture was heated to 40 °C and allowed to react for 6 hours. After the reaction was complete, the mixture was recrystallized with ethyl acetate, and the resulting crystals were washed several times with ethyl acetate after filtration. The crystals were then dried at 40 °C for several hours under vacuum (to below 1 mmHg) to obtain 113 g (0.509 mol) of 1-butyl-1-methylpyrrolidine bromide (halide).

[0255] Next, prepare the above-mentioned halide (113 g, 0.509 mol) and 110 mL of pure water in a 1 L flask. Add dropwise an aqueous solution obtained by dissolving lithium bis(trifluoromethanesulfonyl)imide (151 g, 0.526 mol) in 150 mL of pure water. Stir the reaction mixture at room temperature (20 °C) for about 1 hour, then transfer it to a 1 L separatory funnel. Add 230 mL of dichloromethane for extraction, and wash the collected dichloromethane solution several times with pure water. After washing, collect about 1–2 mL of the aqueous layer and react it with about 1 mL of 0.5 M silver nitrate aqueous solution to check for precipitation. If a white precipitate is observed, since bromide ions cannot be completely removed, wash repeatedly until no white precipitate is observed. After washing with water, concentrate using a rotary evaporator, add a small amount of activated carbon, and stir at room temperature (20 °C) for 1 day. The mixture was passed through a column of neutral alumina and heated and stirred using a vacuum pump (60°C, 4 hours) to obtain an ionic liquid (A-1).

[0256] The obtained ionic liquid (A-1) was 212 g (0.502 mol). Furthermore, the kinematic viscosity of the obtained ionic liquid (A-1) at 40 °C was 25.08 mm. 2 The kinematic viscosity at 100℃ and per second is 5.662 mm³ / s.2 The ionic liquid (A-1) has a viscosity index of 177, a pour point of less than -50°C, a density of 1.401 (15°C), and a 5% mass reduction temperature of 380°C. The structure of A-1 is shown in structural formula (A-1).

[0257] [Chemical Formula 19]

[0258]

[0259] <Ionic Liquid (A-2)>

[0260] • Ionic liquid (A-2): 1-(2-methoxyethyl)-1-methylpyrrolidine-bis(trifluoromethanesulfonyl)amide

[0261] In the synthesis of the ionic liquid (A-1), 2-iodoethyl methyl ether (131 g, 0.705 mol) was used instead of 1-bromobutane. Otherwise, the same procedure was performed to obtain 1-(2-methoxyethyl)-1-methylpyrrolidine onium iodide (146 g, 0.538 mol).

[0262] In addition, in the synthesis of ionic liquid (A-1), 1-(2-methoxyethyl)-1-methylpyrrolidineonium iodide (146 g, 0.538 mol) was used instead of 1-butyl-1-methylpyrrolidineonium bromide. Otherwise, the same operation was carried out to obtain ionic liquid (A-2).

[0263] The obtained ionic liquid (A-2) was 212 g (0.500 mol). Furthermore, the kinematic viscosity of the obtained ionic liquid (A-2) at 40 °C was 21.34 mm. 2 The kinematic viscosity at 100℃ is 5.170 mm³ / s. 2 / s, viscosity index of 187, pour point less than -50℃, density of 1.462 (15℃), and 5% mass reduction temperature of 388℃. The structure of the ionic liquid (A-2) is shown in structural formula (A-2).

[0264] [Chemical Formula 20]

[0265]

[0266] [Preparation of Examples 1-6 and Comparative Examples 1-5]

[0267] The following components were added to the amounts shown in Tables 2 and 3 and mixed thoroughly to obtain a lubricant composition.

[0268] Details of the components used in Examples 1-6 and Comparative Examples 1-5 are shown below.

[0269] The obtained lubricant compositions were evaluated as follows. The results are shown in Tables 2 and 3.

[0270] [Evaluation of solubility (appearance)]

[0271] Three hours after preparation, observe the appearance of the lubricant composition at 20°C and normal pressure, and make the following judgment.

[0272] Transparent: The corrosion inhibitor (B) dissolves in the ionic liquid (A) and becomes colorless and transparent.

[0273] Insoluble: The corrosion inhibitor (B) is not soluble in the ionic liquid (A).

[0274] [Evaluation of low volatility (evaporation rate)]

[0275] Place 100g of each lubricant composition and a stir bar into a flask, reduce the pressure to below 1mmHg using a vacuum pump, and stir in an oil bath at 120°C for 24 hours. After cooling to room temperature, determine the mass of the residual sample, and take the percentage of mass reduction (mass%) as the evaporation amount.

[0276] [Evaluation of resistance to metal corrosion]

[0277] SUS440C plates cut into strips were immersed in a solution containing 10g of distilled water and 10g of each lubricant composition. The solution temperature was set to 60°C, and the SUS440C plates were immersed for 7 days. The appearance of the SUS440C plates was then observed. Corrosion was judged by the presence of brown or black discoloration (rust) on the surface.

[0278] A: Non-corrosive

[0279] B: Corrosion on the surface

[0280] [Table 2]

[0281]

[0282] [Table 3]

[0283]

[0284] As shown in Table 2, the lubricant compositions of Examples 1-6, which satisfy all the requirements of this invention, exhibit excellent resistance to metal corrosion, solubility, and low evaporation. Furthermore, the lubricant compositions of Examples 1-6 all contain 5% corrosion inhibitor (B) and ionic liquid (A) with a mass reduction temperature of 270°C or higher, thus demonstrating excellent stability under high-temperature conditions.

[0285] On the other hand, as shown in Table 3, the lubricant compositions of Comparative Examples 1 and 2 lack sufficient resistance to metal corrosion because they do not contain corrosion inhibitor (B). Furthermore, the corrosion inhibitors in the lubricant compositions of Comparative Examples 3 and 5 are not dissolved in ionic liquids, making it impossible to determine their kinematic viscosity. Additionally, the lubricant composition of Comparative Example 4 has an evaporation rate greater than 0.1% by mass, indicating insufficient low volatility. Moreover, Comparative Examples 4 and 5 contain 5% corrosion inhibitors with a mass reduction temperature below 270°C, which may prevent their use in the high-temperature environment of space.

Claims

1. A compound represented by the following general formula (Bl), In the general formula (B1), M represents an alkali metal, R B11 represents an alkylene group having 3 to 19 carbon atoms.

2. The compound according to claim 1, wherein, M in the general formula (Bl) is selected from sodium and potassium.

3. The compound according to claim 1 or 2, wherein, R in the general formula (B1) is a linear alkylene group. B11 is a linear alkylene group.

4. The compound according to claim 1 or 2, wherein, The R B11 is 5 or more.

5. The compound according to claim 1 or 2, wherein, The R B11 is a group having 17 or less carbon atoms.

6. The compound according to claim 1 or 2, wherein, the 5% mass reduction temperature of the compound represented by the general formula (Bl) is 270°C or higher.

7. A corrosion inhibitor comprising one or more of the compounds according to any one of claims 1 to 6.

8. The corrosion inhibitor according to claim 7, wherein, the content of the compound represented by the general formula (Bl) is 60 to 100 mass% based on the total amount of the corrosion inhibitor (B).

9. A lubricant composition comprising an ionic liquid (A) and the corrosion inhibitor (B) according to claim 7 or 8.

10. The lubricant composition according to claim 9, wherein, the total content of the ionic liquid (A) and the corrosion inhibitor (B) is 70 mass% or more.

11. The lubricant composition according to claim 9 or 10, wherein, the total content of the ionic liquid (A) and the corrosion inhibitor (B) is 100 mass% or less.

12. The lubricant composition of claim 9 or 10, wherein, the content of the compound represented by the general formula (Bl) is 0.01 to 10 mass% based on 100 mass% of the total amount of the lubricant composition.

13. The lubricant composition of claim 9 or 10, wherein, the content of the compound represented by the general formula (Bl) is 0.1 to 10 mass% based on the total amount of the lubricant composition.

14. The lubricant composition according to claim 9 or 10, wherein, the content of the corrosion inhibitor (B) is 0.01 to 10 mass% based on 100 mass% of the total amount of the lubricant composition.

15. The lubricant composition according to claim 9 or 10, wherein, the corrosion inhibitor (B) is used singly.

16. The lubricant composition according to claim 9 or 10, wherein, the anion of the ionic liquid (A) comprises bis(trifluoromethylsulfonyl)amide.

17. The lubricant composition of claim 9 or 10, wherein, the ionic liquid (A) comprises a cation represented by the following general formula (Al), In the general formula (Al), n is 1 or 2, X is methylene or oxygen, R A11 , R A12 each independently is a group selected from an alkyl group having 1 to 12 carbon atoms optionally having an ether group, an ester group, a nitrile group, a silyl group.

18. The lubricant composition according to claim 17, wherein, The carbon number of the alkyl group of R A11 and R A12 in the general formula (A1) is independently 1 to 6.

19. The lubricant composition according to claim 17, wherein, R in the general formula (A1) is A11 methyl.

20. The lubricant composition according to claim 17, wherein, R in the general formula (A1) is A12 selected from n-butyl and methoxyethyl.

21. The lubricant composition according to claim 17, wherein, The cation represented by the general formula (Al) is selected from the group consisting of 1-butyl-l-methylpyrrolidinium, 1-pentyl-l-methylpyrrolidinium, 1-hexyl-l-methylpyrrolidinium, 1-heptyl-l-methylpyrrolidinium, 1-octyl-l-methylpyrrolidinium, 1-nonyl-l-methylpyrrolidinium, 1-decyl-l-methylpyrrolidinium, 1-undecyl-l-methylpyrrolidinium, 1-dodecyl-l-methylpyrrolidinium, 1-methoxymethyl-l-methylpyrrolidinium, 1-(2-methoxyethyl)-l-methylpyrrolidinium, 1-(2-methoxy-2-oxoethyl)-l-methylpyrrolidinium, 1-cyanomethyl-l-methylpyrrolidinium, 1-trimethylsilylmethyl-l-methylpyrrolidinium, 1-butyl-l-methylpiperidinium, 1-pentyl-l-methylpiperidinium, 1-hexyl-l-methylpiperidinium, 1-heptyl-l-methylpiperidinium, 1-octyl-l-methylpiperidinium, 1-nonyl-l-methylpiperidinium, 1-decyl-l-methylpiperidinium, 1-undecyl-l-methylpiperidinium, 1-dodecyl-l-methylpiperidinium, 1-methoxymethyl-l-methylpiperidinium, 1-(2-methoxyethyl)-l-methylpiperidinium, 1-(2-methoxy-2-oxoethyl)-l-methylpiperidinium, 1-cyanomethyl-l-methylpiperidinium, 1-trimethylsilylmethyl-l-methylpiperidinium, 1-butyl-l-methylmorpholinium, 1-pentyl-l-methylmorpholinium, 1-hexyl-l-methylmorpholinium, 1-heptyl-l-methylmorpholinium, 1-octyl-l-methylmorpholinium, 1-nonyl-l-methylmorpholinium, 1-decyl-l-methylmorpholinium, 1-undecyl-l-methylmorpholinium, 1-dodecyl-l-methylmorpholinium, 1-(2-methoxyethyl)-l-methylmorpholinium, 1-methoxymethyl-l-methylmorpholinium, 1-(2-methoxy-2-oxoethyl)-l-methylmorpholinium, 1-cyanomethyl-l-methylmorpholinium, and 1-trimethylsilylmethyl-l-methylmorpholinium.

22. The lubricant composition of claim 9 or 10, wherein, The ionic liquid (A) contains at least one of a compound represented by the following general formula (A2) and a compound represented by the following general formula (A3), In the general formula (A2), n is 1 or 2, X is methylene or oxygen, R A21 represents an alkyl group having 2 to 12 carbon atoms, In the general formula (A3), n is 1 or 2, X is methylene or oxygen, R A31 represents an alkylene group having 1 to 5 carbon atoms, R A32 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

23. The lubricant composition according to claim 22, wherein R in the general formula (A2) is a group having 2 to 8 carbon atoms. A21 having 2 to 8 carbon atoms.

24. The lubricant composition according to claim 22, wherein The content of the compound represented by the general formula (A2) is 60 to 100% by mass based on the total amount of the ionic liquid (A).

25. The lubricant composition according to claim 22, wherein R in the general formula (A3) is a group having 1 to 3 carbon atoms. A31 having 1 to 3 carbon atoms.

26. The lubricant composition according to claim 22, wherein R in the general formula (A3) is a group having 1 to 2 carbon atoms. A32 having 1 to 2 carbon atoms.

27. The lubricant composition of claim 22, wherein, The content of the compound represented by the general formula (A3) is 60 to 100% by mass based on the total amount of the ionic liquid (A).

28. The lubricant composition according to claim 9 or 10, wherein The ionic liquid (A) has a kinematic viscosity at 40°C of 2.0 mm 2 / s ~ 100.0 mm 2 / s.

29. The lubricant composition according to claim 9 or 10, wherein The ionic liquid (A) has a kinematic viscosity at 100°C of 1.0 mm 2 / s ~ 20.0 mm 2 / s.

30. The lubricant composition according to claim 9 or 10, wherein The ionic liquid (A) has a viscosity index of 100 or more.

31. The lubricant composition according to claim 9 or 10, wherein The ionic liquid (A) has a pour point of 0°C or less.

32. The lubricant composition according to claim 9 or 10, wherein The ionic liquid (A) has an acid value of 1 mgKOH / g or less.

33. The lubricant composition according to claim 9 or 10, wherein The ionic liquid (A) has a flash point of 200°C or more.

34. The lubricant composition according to claim 9 or 10, wherein The ionic liquid (A) has a molecular weight of 410 or more and 570 or less.

35. The lubricant composition according to claim 9 or 10, wherein The content of the ionic liquid (A) is 60 mass% to 99.5 mass% based on the total amount of the lubricant composition.

36. The lubricant composition of claim 9 or 10, wherein, The ratio of the content of the compound represented by the general formula (Bl) to the content of the ionic liquid (A), i.e., Bl / A, is 0.0005 or more and 0.15 or less in terms of mass ratio.

37. The lubricant composition of claim 9 or 10 having a kinematic viscosity at 40 °C of 2.0 mm 2 / s to 100.0 mm 2 / s.

38. The lubricant composition of claim 9 or 10 having a kinematic viscosity at 100 °C of 1.0 mm 2 / s ~ 20.0 mm 2 / s.

39. The lubricant composition according to claim 9 or 10, which has a viscosity index of 100 or more.

40. A method for producing a lubricant composition, comprising a step of mixing an ionic liquid (A) with a compound represented by the following general formula (Bl), In the general formula (B1), M represents an alkali metal, R B11 represents an alkylene group having 1 to 19 carbon atoms.

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