Compressor oil composition

Abstract

A gas compressor oil composition containing a base oil (A), the base oil (A) containing a hydrocarbon base oil (A1) having biomass-derived carbon, and the content of biomass-derived carbon measured in accordance with ASTM D6866 being 20 mass% or more based on the total carbon in the gas compressor oil composition.

Description

Technical Field

[0001] This invention relates to compressor oil compositions.

[0002] This application claims priority based on Japanese Patent Application No. 2023-169160, filed in Japan on September 29, 2023, the contents of which are incorporated herein by reference. Background Technology

[0003] In an air compressor, adiabatic compression occurs when gas is compressed, converting compression energy into heat, and the gas becomes high-temperature gas.

[0004] The gas compressor oil composition is used to cool the compression section of an air compressor that reaches high temperatures, improve the lubrication of the drive section, and prevent gas leakage from the compression section.

[0005] In recent years, from the perspective of preserving the natural environment, there has been a growing call for building a circular economy society, with the aim of moving away from fossil resources and achieving so-called carbon neutrality. Therefore, the utilization of biomass-derived raw materials has attracted attention. Biomass refers to renewable organic resources derived from living organisms, excluding fossil resources.

[0006] Biomass-derived feedstocks do not affect the concentration of carbon dioxide in the atmosphere, thus carbon neutrality can be achieved by using biomass-derived feedstocks.

[0007] As a composition containing a base oil derived from biomass, for example, Patent Document 1 discloses a hydraulic oil containing a base oil derived from biomass and an antioxidant.

[0008] Existing technical documents Patent documents Patent Document 1: International Publication No. 2015 / 192072 Summary of the Invention

[0009] The problem that the invention aims to solve Regarding the conventional hydraulic working oil described in Patent Document 1, studies were conducted on reducing environmental impact, but the required functions as a gas compressor oil composition were not verified.

[0010] As a gas compressor oil composition, it requires high oxidation stability, rust prevention, defoaming and water separation properties.

[0011] The present invention was made in view of the above circumstances, and its object is to provide a gas compressor oil composition that can preserve the natural environment while maintaining good oxidation stability, rust prevention, defoaming and water separation properties.

[0012] Methods for solving problems To address the aforementioned issues, the present invention employs the following configuration.

[0013] [1] A gas compressor oil composition comprising a base oil (A) wherein the base oil (A) comprises a hydrocarbon base oil (A1) having carbon derived from biomass, wherein the content of carbon derived from biomass as determined by ASTM D6866 is 20% by mass or more based on the total carbon in the gas compressor oil composition.

[0014] [2] The gas compressor oil composition according to [1], wherein the content of biomass-derived carbon, as determined according to ASTM D6866, is 40% by mass or more based on the total carbon content in the gas compressor oil composition.

[0015] [3] The gas compressor oil composition according to [1] or [2] is used in a screw gas compressor.

[0016] [4] The gas compressor oil composition according to any one of [1] to [3] further comprises an antioxidant.

[0017] [5] The gas compressor oil composition according to [4], wherein the antioxidant is an amine compound.

[0018] Invention Effects According to the present invention, a gas compressor oil composition can be provided that preserves the natural environment while maintaining good oxidation stability, rust prevention, defoaming and water separation properties. Detailed Implementation

[0019] (Gas compressor oil composition) The gas compressor oil composition of this embodiment is a composition for a compressor used to compress gas.

[0020] In the gas compressor oil composition of this embodiment, the content of biomass-derived carbon, as determined according to ASTM D6866, is 20% by mass or more, preferably 40% by mass or more, more preferably 60% by mass or more, and even more preferably 80% by mass or more, based on the total carbon content in the gas compressor oil composition.

[0021] There is no upper limit to the carbon content derived from biomass as determined by ASTM D6866; it can be below 100% by mass or below 99% by mass.

[0022] ASTM D6866 (Test Standard for Bio-based Concentrations) is a standard developed to determine the bio-based content of solids, liquids, and gases using radiocarbon (C14) analysis. Biomass contains a certain amount of radiocarbon (C14), therefore, feedstocks derived from biomass also contain radiocarbon (C14). On the other hand, feedstocks derived from fossil resources do not contain radiocarbon (C14). Therefore, by measuring the concentration of radiocarbon (C14) in a gas compressor oil composition, the carbon content derived from biomass can be calculated.

[0023] The kinematic viscosity of the gas compressor oil composition in this embodiment at 40°C is preferably 15 mm. 2 / s or higher, more preferably 20mm 2 / s or higher, further preferably 25mm 2 / s or more.

[0024] The kinematic viscosity of the gas compressor oil composition in this embodiment at 40°C is preferably 65 mm. 2 / s or less, more preferably 60mm 2 / s or less, preferably 55mm 2 / s or less.

[0025] For example, the kinematic viscosity of the gas compressor oil composition in this embodiment at 40°C is preferably 15 mm. 2 / s or higher and 65mm 2 / s or less, more preferably 20mm 2 / s or higher and 60mm 2 / s or less, preferably 25mm 2 / s or higher and 55mm 2 / s or less.

[0026] When the kinematic viscosity of the gas compressor oil composition in this embodiment at 40°C is above the aforementioned preferred lower limit, the lubricity of the drive unit is further improved.

[0027] When the kinematic viscosity of the gas compressor oil composition of this embodiment at 40°C is below the aforementioned preferred upper limit, the cooling efficiency of the compression section is further improved. Furthermore, when the kinematic viscosity of the gas compressor oil composition of this embodiment at 40°C is below the aforementioned preferred upper limit, the power consumption of the pump circulating the gas compressor oil composition can be further reduced by improving the circulation efficiency.

[0028] The kinematic viscosity of the gas compressor oil composition in this embodiment at 100°C is preferably 1.0 mm. 2 / s or more, preferably 2.0mm 2 / s or higher, preferably 3.0mm 2 / s or more.

[0029] The kinematic viscosity of the gas compressor oil composition in this embodiment at 100°C is preferably 20 mm. 2 / s or less, more preferably 15mm 2 / s or less, more preferably 10mm 2 / s or less.

[0030] For example, the kinematic viscosity of the gas compressor oil composition in this embodiment at 100°C is preferably 1.0 mm. 2 / s or higher and 20mm 2 / s or less, more preferably 2.0mm 2 / s or higher and 15mm 2 / s or less, more preferably 3.0mm 2 / s or more and 10mm 2 / s or less.

[0031] When the kinematic viscosity of the gas compressor oil composition in this embodiment at 100°C is above the aforementioned preferred lower limit, the lubricity of the drive unit is further improved.

[0032] When the kinematic viscosity of the gas compressor oil composition of this embodiment at 100°C is below the aforementioned preferred upper limit value, the cooling efficiency of the compression section is further improved. Furthermore, when the kinematic viscosity of the gas compressor oil composition of this embodiment at 100°C is below the aforementioned preferred upper limit value, by improving the circulation efficiency, the power consumption of the pump circulating the gas compressor oil composition can be further reduced.

[0033] The viscosity index of the gas compressor oil composition of this embodiment is preferably 120 or higher, more preferably 130 or higher, and even more preferably 140 or higher.

[0034] When the viscosity index of the gas compressor oil composition in this embodiment is above the preferred lower limit, the change in kinematic viscosity due to temperature changes is smaller, thus further improving the lubricity at high temperatures.

[0035] The upper limit of the viscosity index of the gas compressor oil composition in this embodiment is not particularly limited, but is generally 200 or less, for example, 150 or less.

[0036] The kinematic viscosity and viscosity index at 40℃ and 100℃ mentioned in this specification refer to the values ​​measured in accordance with JIS K2283:2000 "Crude oil and petroleum products - Test method for kinematic viscosity and method for calculation of viscosity index".

[0037] The density of the gas compressor oil composition in this embodiment at 15°C is preferably 0.60 g / cm³. 3The above, and more preferably, is 0.70 g / cm³. 3 The above, and more preferably, is 0.80 g / cm³. 3 above.

[0038] The density of the gas compressor oil composition in this embodiment at 15°C is preferably 1.10 g / cm³. 3 The following, or more preferably, is 1.00 g / cm³. 3 The following, and more preferably, is 0.90 g / cm³. 3 the following.

[0039] For example, the density of the gas compressor oil composition of this embodiment at 15°C is preferably 0.60 g / cm³. 3 Above and 1.10 g / cm 3 The following, or more preferably, is 0.70 g / cm³. 3 Above and 1.00 g / cm 3 The following, and more preferably, is 0.80 g / cm³. 3 Above and 0.90 g / cm 3 the following.

[0040] The density at 15°C in this specification refers to the value measured according to JIS K2249-1:2011.

[0041] <Base Oil (A)> The preferred kinematic viscosity of base oil (A) at 40°C is 15 mm. 2 / s or higher, more preferably 20mm 2 / s or higher, further preferably 25mm 2 / s or more.

[0042] The preferred kinematic viscosity of base oil (A) at 40°C is 65 mm. 2 / s or less, more preferably 60mm 2 / s or less, preferably 55mm 2 / s or less.

[0043] For example, the kinematic viscosity of base oil (A) at 40°C is preferably 15 mm. 2 / s or higher and 65mm 2 / s or less, more preferably 20mm 2 / s or higher and 60mm 2 / s or less, preferably 25mm 2 / s or higher and 55mm 2 / s or less.

[0044] When the kinematic viscosity of the base oil (A) of the gas compressor oil composition of this embodiment at 40°C is above the aforementioned preferred lower limit, the lubricity of the drive unit is further improved.

[0045] When the kinematic viscosity of the base oil (A) of the gas compressor oil composition in this embodiment is below the aforementioned preferred upper limit value, the cooling efficiency of the compression section is further improved. Furthermore, when the kinematic viscosity of the base oil (A) is below the aforementioned preferred upper limit value, the power consumption of the pump circulating the gas compressor oil composition can be further reduced by improving the circulation efficiency.

[0046] Base oil (A) contains hydrocarbon base oil (A1) with carbon derived from biomass.

[0047] Hydrocarbon base oils containing carbon derived from biomass (A1) As a hydrocarbon base oil (A1) containing carbon derived from biomass (hereinafter also referred to as "(A1) component"), specifically, hydrocarbon base oils synthesized from vegetable oils such as coconut oil, copra oil, soybean oil, rapeseed oil, corn oil and mixtures thereof can be listed.

[0048] Examples of commercially available products containing (A1) ingredients include SynNova 4 Base Oil (manufactured by Novvi Corporation), SynNova 9 Base Oil (manufactured by Novvi Corporation), and NovaSolv 160 (manufactured by Novvi Corporation).

[0049] In the (A1) component, the content of biomass-derived carbon as determined according to ASTM D6866 is preferably 20% by mass or more, more preferably 60% by mass or more, further preferably 80% by mass or more, and particularly preferably 100% by mass.

[0050] The kinematic viscosity of component (A1) at 40°C is preferably 5.0 mm. 2 / s or higher, preferably 10mm 2 / s or higher, further preferably 15mm 2 / s or more.

[0051] The kinematic viscosity of component (A1) at 40°C is preferably 75 mm. 2 / s or less, preferably 70mm 2 Below / s, 65mm is further preferred. 2 / s or less.

[0052] For example, the kinematic viscosity of component (A1) at 40°C is preferably 5.0 mm. 2 / s or higher and 75mm 2 / s or less, preferably 10mm 2 / s or higher and 70mm 2 Below / s, further preferably 15mm 2 / s or higher and 65mm 2 / s or less.

[0053] If the kinematic viscosity of component (A1) at 40°C is above the preferred lower limit value, the lubricity of the drive unit is further improved.

[0054] When the kinematic viscosity of component (A1) at 40°C is below the aforementioned preferred upper limit, the cooling efficiency in the compression section is further improved. Furthermore, when the kinematic viscosity of component (A1) at 40°C is below the aforementioned preferred upper limit, by improving the circulation efficiency, the power consumption of the pump circulating the gas compressor oil composition can be further reduced.

[0055] In the gas compressor oil composition of this embodiment, one (A1) component may be used alone, or multiple (A1) components may be used in combination.

[0056] The content of component (A1) relative to the total amount of base oil (A) is preferably 50% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and may also be 100% by mass.

[0057] Base oil (A) may contain base oil (A2) other than the components mentioned above (A1).

[0058] Base oils other than (A1) components (A2) Base oils (A2) other than the above-mentioned (A1) components (hereinafter also referred to as "(A2) components") can specifically include synthetic oils and mineral oils.

[0059] Synthetic oil Examples of synthetic oils include polyolefins such as poly-α-olefins, ester base oils such as diesters and polyol esters, polyalkylene glycols, alkylbenzenes and alkylnaphthalenes, etc.

[0060] Mineral oil As a mineral oil, distillate obtained by atmospheric distillation of crude oil can be used. Alternatively, lubricating oil fractions obtained by further vacuum distillation of the distillate can be used.

[0061] As a refining process, hydrorefining, solvent extraction, solvent dewaxing, hydrodewaxing, sulfuric acid washing, and clay treatment can be appropriately combined. By combining these refining processes in a suitable order, mineral oil can be obtained.

[0062] Alternatively, a mixture of various refined oils with different properties can be used, obtained by combining different crude oils or distillates with different refining processes.

[0063] As component (A2), one of the above-mentioned synthetic oils or mineral oils may be used alone, or multiple synthetic oils or mineral oils may be used in combination.

[0064] The content of base oil (A) in the gas compressor oil composition of this embodiment is preferably 90% by mass or more, more preferably 92% by mass or more, and even more preferably 95% by mass or more relative to the total amount of the gas compressor oil composition.

[0065] The upper limit of the content of base oil (A) in the gas compressor oil composition of this embodiment is not particularly limited. For example, it can be 99% by mass or less, or 98% by mass or less.

[0066] As the base oil (A) in the gas compressor oil composition of this embodiment, it is preferable to contain only the (A1) component.

[0067] <Optional Ingredients> The gas compressor oil composition of this embodiment may contain optional components other than the base oil (A) described above. Examples of such optional components include antioxidants, rust inhibitors, metal passivators, defoamers, anti-wear agents or extreme pressure agents, pour point depressants, and metal detergents.

[0068] Antioxidants Examples of antioxidants include phenolic compounds and amine compounds.

[0069] As phenolic compounds, examples include 2,6-di-tert-butylphenol and 2,6-di-tert-butyl-p-cresol.

[0070] Examples of amine compounds include phenyl-α-naphthylamine, diphenylamine, dialkyldiphenylamine, and p-alkylphenyl-α-naphthylamine.

[0071] ·Phenylacetylamine As phenyl-α-naphthylamine, compounds represented by the following general formula (1) can be listed.

[0072] [Chemical Formula 1] In equation (1), R 1 This refers to a straight-chain or branched alkyl group having 1 to 16 hydrogen or carbon atoms. As R 1Alkyl groups having 1 to 16 carbon atoms, either straight-chain or branched, such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, and hexadecyl (these alkyl groups can be straight-chain or branched).

[0073] As represented by general formula (1), phenyl-α-naphthylamine can be either commercially available or synthesized. The synthesized product can be readily synthesized by reacting phenyl-α-naphthylamine with a haloalkyl compound having 1 to 16 carbon atoms, or by reacting phenyl-α-naphthylamine with an olefin having 2 to 16 carbon atoms or an olefin oligomer having 2 to 16 carbon atoms, using a Fried-Kraft catalyst. Examples of Fried-Kraft catalysts include metal halides such as aluminum chloride, zinc chloride, and ferric chloride; and acidic catalysts such as sulfuric acid, phosphoric acid, phosphorus pentoxide, boron fluoride, acid clay, and activated clay.

[0074] Diphenylamine, dialkyldiphenylamine As diphenylamine, dialkyldiphenylamine, specifically, compounds represented by the following general formula (2) can be listed.

[0075] [Chemical Formula 2] In equation (2), R 2 and R 3 Each can independently represent an alkyl group having 1 to 16 hydrogen atoms or carbon atoms. As R 2 and R 3 Specifically, the alkyl groups represented can include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, etc. (these alkyl groups can be straight-chain or branched). Among them, considering excellent solubility, R... 2 and R 3 Branched alkyl groups having 3 to 16 carbon atoms are preferred, and branched alkyl groups having 3 to 16 carbon atoms derived from olefins having 3 or 4 carbon atoms or their oligomers are more preferred. Specifically, examples of olefins having 3 or 4 carbon atoms include propylene, 1-butene, 2-butene, and isobutene; propylene or isobutene are preferred from the perspective of excellent solubility. Furthermore, as R... 2 Or R 3From the perspective of obtaining better solubility, it is even more preferable to use isopropyl derived from propylene, tert-butyl derived from isobutylene, branched hexyl derived from propylene dimer, branched octyl derived from isobutylene dimer, branched nonyl derived from propylene trimer, branched dodecyl derived from isobutylene trimer, branched dodecyl derived from propylene tetramer, or branched pentadecyl derived from propylene pentamer. Most preferably, it is tert-butyl derived from isobutylene, branched hexyl derived from propylene dimer, branched octyl derived from isobutylene dimer, branched nonyl derived from propylene trimer, branched dodecyl derived from isobutylene trimer, or branched dodecyl derived from propylene tetramer.

[0076] The gas compressor oil composition of this embodiment can use one antioxidant alone or a mixture of multiple antioxidants.

[0077] The content of antioxidant relative to the total amount of the gas compressor oil composition of this embodiment is preferably 0.5% by mass or more, more preferably 1.0% by mass or more, and even more preferably 1.5% by mass or more.

[0078] The content of antioxidant relative to the total amount of the gas compressor oil composition of this embodiment is preferably 3.5% by mass or less, more preferably 3.0% by mass or less, and even more preferably 2.5% by mass or less.

[0079] For example, the content of antioxidant relative to the total amount of the gas compressor oil composition of this embodiment is preferably 0.5% by mass or more and 3.5% by mass or less, 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.

[0080] When the content of antioxidant is above the preferred lower limit mentioned above, the oxidative stability is further improved.

[0081] When the content of antioxidants is below the upper limit of the above-mentioned preferred values, the generation of sludge can be further reduced.

[0082] Rust Inhibitor Examples of rust inhibitors include alkenyl succinates, petroleum sulfonates, alkylbenzene sulfonates, dinonylnaphthalene sulfonates, and polyol esters.

[0083] The gas compressor oil composition of this embodiment can use one type of rust inhibitor alone, or it can use a mixture of multiple rust inhibitors.

[0084] The content of the rust inhibitor relative to the total amount of the gas compressor oil composition of this embodiment is preferably 0.001% by mass or more, more preferably 0.005% by mass or more, and even more preferably 0.01% by mass or more.

[0085] The content of the rust inhibitor relative to the total amount of the gas compressor oil composition of this embodiment is preferably 1.0% by mass or less, more preferably 0.5% by mass or less, and even more preferably 0.1% by mass or less.

[0086] For example, the content of the rust inhibitor relative to the total amount of the gas compressor oil composition of this embodiment is preferably 0.001% by mass or more and 1.0% by mass or less, more preferably 0.005% by mass or more and 0.5% by mass or less, and even more preferably 0.01% by mass or more and 0.1% by mass or less.

[0087] When the content of the rust inhibitor is above the lower limit of the above-mentioned preferred value, the rust prevention performance is further improved.

[0088] When the content of the rust inhibitor is below the upper limit of the above-mentioned preferred value, the oxidation stability is further improved.

[0089] Metal passivating agents As metal passivating agents, known metal passivating agents such as benzotriazole compounds, toluyltriazole compounds, thiadiazole compounds, and imidazole compounds can be used. Among them, benzotriazole compounds are preferred, and N,N-bis(2-ethylhexyl)-4-methyl-1H-benzotriazole-1-methaneamine is more preferred.

[0090] The gas compressor oil composition of this embodiment can use one type of metal passivator alone, or it can use a mixture of multiple metal passivators.

[0091] The content of the metal passivating agent relative to the total amount of the gas compressor oil composition of this embodiment is preferably 0.001% by mass or more, more preferably 0.003% by mass or more, and even more preferably 0.005% by mass or more.

[0092] The content of the metal passivating agent relative to the total amount of the gas compressor oil composition of this embodiment is preferably 0.5% by mass or less, more preferably 0.3% by mass or less, and even more preferably 0.1% by mass or less.

[0093] For example, the content of the metal passivator relative to the total amount of the gas compressor oil composition of this embodiment is preferably 0.001% by mass or more and 0.5% by mass or less, more preferably 0.003% by mass or more and 0.3% by mass or less, and even more preferably 0.005% by mass or more and 0.1% by mass or less.

[0094] When the content of the metal passivating agent is above the lower limit of the above-mentioned preferred value, the corrosion resistance of the metal is further improved.

[0095] When the content of the metal passivating agent is below the upper limit of the above-mentioned preferred value, the oxidation stability is further improved.

[0096] Defoamer As defoamers, examples include silicone-based defoamers.

[0097] Examples of silicone-based defoamers include dimethylpolysiloxane and trimethylsiloxy-terminated dimethylsiloxane.

[0098] The gas compressor oil composition of this embodiment can use one type of defoamer alone or a mixture of multiple defoamers.

[0099] The content of the defoamer relative to the total amount of the gas compressor oil composition of this embodiment is preferably 0.00001% by mass or more, more preferably 0.00003% by mass or more, and even more preferably 0.00005% by mass or more.

[0100] The content of the defoamer relative to the total amount of the gas compressor oil composition of this embodiment is preferably 0.001% by mass or less, more preferably 0.0008% by mass or less, and even more preferably 0.0005% by mass or less.

[0101] For example, the content of the defoamer relative to the total amount of the gas compressor oil composition of this embodiment is preferably 0.00001% by mass or more and 0.001% by mass or less, more preferably 0.00003% by mass or more and 0.0008% by mass or less, and even more preferably 0.00005% by mass or more and 0.0005% by mass or less.

[0102] Anti-wear agents or extreme pressure agents Examples of anti-wear agents or extreme pressure agents include organic zinc compounds such as zinc dialkyl dithiophosphate and zinc dialkyl dithiocarbamate; sulfur-containing compounds such as molybdenum dialkyl dithiocarbamate, dialkyl polysulfides, sulfur esters, thiazole compounds, and thiadiazole compounds; and phosphorus-based extreme pressure agents such as phosphate esters, acid phosphate esters, amine salts of acid phosphate esters, and phosphites.

[0103] As phosphorus-based extreme pressure agents, phosphate esters, acid phosphate esters, amine salts of acid phosphate esters, chlorinated phosphate esters, phosphites, and thiophosphate esters are preferred.

[0104] Specifically, examples of phosphate esters include tributyl phosphate, tripentyl phosphate, trihexyl phosphate, triheptyl phosphate, trioctyl phosphate, trinonyl phosphate, tridecyl phosphate, tri(undecyl) phosphate, tri(dodecyl) phosphate, tri(tetranyl) phosphate, tri(tetradecyl) phosphate, tri(pentadecanyl) phosphate, tri(hexadecyl) phosphate, tri(heptadecanyl) phosphate, tri(octadecyl) phosphate, trioleyl phosphate, triphenyl phosphate, tricresyl phosphate, tri(xylyl) phosphate, toluene diphenyl phosphate, and xylyl diphenyl phosphate, with tricresyl phosphate being preferred.

[0105] The gas compressor oil composition of this embodiment can use one type of anti-wear agent and extreme pressure agent alone, or it can use a mixture of multiple anti-wear agents and extreme pressure agents.

[0106] The content of anti-wear agent and extreme pressure agent relative to the total amount of the gas compressor oil composition of this embodiment is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and even more preferably 0.1% by mass or more.

[0107] The content of anti-wear agent and extreme pressure agent relative to the total amount of the gas compressor oil composition of this embodiment is preferably 2.0% by mass or less, more preferably 1.5% by mass or less, and even more preferably 1.0% by mass or less.

[0108] For example, the content of anti-wear agent and extreme pressure agent relative to the total amount of the gas compressor oil composition of this embodiment is preferably 0.01% by mass or more and 2.0% by mass or less, more preferably 0.05% by mass or more and 1.5% by mass or less, and even more preferably 0.1% by mass or more and 1.0% by mass or less.

[0109] If the content of anti-wear agent and extreme pressure agent is above the lower limit of the above-mentioned preferred values, the wear resistance will be further improved.

[0110] If the content of anti-wear agent and extreme pressure agent is below the above-mentioned preferred upper limit, the demulsibility is further improved, and the generation of sludge can be further suppressed.

[0111] Pour point lowering agents As a pour point depressant, a polymethacrylate-based polymer suitable for base oil (A) is preferred, and a polyalkyl methacrylate is more preferred.

[0112] The gas compressor oil composition of this embodiment can use one pour point depressant alone, or multiple pour point depressants can be used in combination.

[0113] The content of the pour point lowering agent relative to the total amount of the gas compressor oil composition of this embodiment is preferably 0.01% by mass or more, more preferably 0.03% by mass or more, and even more preferably 0.05% by mass or more.

[0114] When the content of the pour point depressant is above the preferred lower limit value, the low-temperature fluidity of the gas compressor oil composition of this embodiment is further improved.

[0115] There is no particular limit to the upper limit of the content of the pour point lowering agent. For example, relative to the total amount of the gas compressor oil composition of this embodiment, it is preferably 0.50% by mass or less, more preferably 0.20% by mass or less, and even more preferably 0.15% by mass or less.

[0116] The gas compressor oil composition of this embodiment is particularly useful as a gas compressor oil composition for screw-type gas compressors due to its high oxidation stability, water separation properties, rust prevention, defoaming properties, low sludge production, and low misting. Here, a screw-type gas compressor refers to a device that compresses gas by changing the volume between the screw and the housing through the rotation of a screw rotor.

[0117] Example The present invention will be described in more detail below through embodiments, but the present invention is not limited to the following embodiments.

[0118] <Formulation of Gas Compressor Oil Composition> The gas compressor oil compositions of Examples 1-3 and Comparative Examples 1-3 were prepared by mixing the components according to the proportions shown in Tables 1 and 2. In Tables 1 and 2, the value of component (A) refers to the content (mass %) of each base oil relative to the total amount of component (A), and the values ​​of components other than component (A) refer to the content (mass %) of each component relative to the total amount of the gas compressor oil composition. Therefore, the content of component (A) relative to the total amount of the gas compressor oil composition is the balance obtained by subtracting the content of components other than component (A) from 100% by mass.

[0119] (1) Base oil (A) A1-1: 100% plant-derived hydrocarbon-based lubricating oil base (product name "SynNova 4 Base Oil", manufactured by Novvi, kinematic viscosity at 40°C: 19.74 mm). 2 kinematic viscosity at 100℃ and per second: 4.382 mm³ / s 2 (Viscosity index: 135).

[0120] A1-2: 100% plant-derived hydrocarbon-based lubricating oil base (product name "SynNova 9 Base Oil", manufactured by Novvi, kinematic viscosity at 40°C: 57.15 mm). 2 kinematic viscosity at 100℃ and per second: 9.398 mm³ / s 2 (Viscosity index: 147).

[0121] a-1: Mineral oil (kinematic viscosity at 40℃: 19.12 mm) 2 kinematic viscosity at 100℃ / s: 4.188 mm³ / s 2 (Viscosity index: 124).

[0122] a-2: Mineral oil (kinematic viscosity at 40℃: 37.51 mm) 2 kinematic viscosity at 100℃ and per second: 6.550 mm³ / s 2 (Viscosity index: 129).

[0123] a-3: Mineral oil (kinematic viscosity at 40℃: 45.39 mm) 2 kinematic viscosity at 100℃ and per second: 7.615 mm³ / s 2 (Viscosity index: 135).

[0124] (2) Additives X-1: N-(dodecylphenyl)-naphth-1-amine X-2:4-Octyl-N-phenyl-1-naphthylamine X-3: Monobutylphenyl monooctylamine X-4: Alkenyl succinate X-5: Alkenyl succinic acid polyol ester X-6: Trimethylbenzene Phosphate X-7: (N,N-bis(2-ethylhexyl)-4-methyl-1H-benzotriazole-1-methylamine), trade name: Irgamet39, manufactured by BASF. X-8: Alkyl polymethacrylate X-9: Trimethylsiloxy-terminated dimethylsiloxane <Characteristic Evaluation of Gas Compressor Oil Compositions> The gas compressor oil compositions of Examples 1-3 and Comparative Examples 1-3 are shown in Tables 1 and 2. It should be noted that the physical properties shown in Tables 1 and 2 were determined according to the test methods described below.

[0125] Bio-based content: ASTM D6866 Density: JIS K2249-1:2011 Flash point (COC: Cleveland open cup method): JIS K2265-4:2007 Kinematic viscosity: JIS K2283:2000 Viscosity index: JIS K2283:2000 Acid value: JIS K2501:2003 ASTM color: JIS K2580:2003 Pour point: JIS K2269:1987 Rust resistance: JIS K2510:1998 Foaming properties: JIS K2518:2017 Demulsibility: JIS K2520:2000 Oxidative stability (RPVOT test): JIS K2514-3:2013 As shown in Tables 1 and 2, the gas compressor oil compositions of the embodiments have a high bio-based content, which can protect the natural environment, and the oxidation stability, rust prevention, defoaming and water separation properties are maintained at the same level as the gas compressor oil compositions of the comparative examples.

[0126] The preferred embodiments of the present invention have been described above, but the present invention is not limited to these embodiments. Additions, omissions, substitutions, and other modifications to the structure can be made without departing from the spirit of the present invention. The present invention is not limited by the foregoing description, but only by the scope of the appended claims.

Claims

1. A gas compressor oil composition, comprising a base oil (A), wherein, The base oil (A) comprises a hydrocarbon base oil (A1) having carbon derived from biomass. The carbon content derived from biomass, as determined according to ASTM D6866, is ≥20% by mass based on the total carbon content in the gas compressor oil composition.

2. The gas compressor oil composition according to claim 1, wherein, The carbon content derived from biomass, as determined according to ASTM D6866, is 40% by mass or more, based on the total carbon content in the gas compressor oil composition.

3. The gas compressor oil composition according to claim 1 or 2, used in a screw-type gas compressor.

4. The gas compressor oil composition according to claim 1 or 2, further comprising an antioxidant.

5. The gas compressor oil composition according to claim 4, wherein, The antioxidant is an amine compound.

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