Gas compressor oil composition

Abstract

Provided is a gas compressor oil composition containing a base oil (A) and a degradation product dissolving agent (B), wherein the base oil (A) contains a hydrocarbon base oil (A1) having biomass-derived carbon, and the content of biomass-derived carbon as measured by ASTM D6866 is 20 mass% or more in terms of the total carbon in the gas compressor oil composition.

Description

Gas compressor oil composition

[0001] The present invention relates to a gas compressor oil composition. This application claims priority to Japanese Patent Application No. 2023-169187, filed on September 29, 2023, the contents of which are incorporated herein by reference.

[0002] In an air compressor, when gas is compressed, adiabatic compression occurs, and the compression energy is converted into heat, causing the gas to reach a high temperature. Gas compressor oil compositions are used to cool the compression section of an air compressor that reaches a high temperature, to improve the lubricity of the drive section, and to prevent gas leakage from the compression section.

[0003] In recent years, there has been growing demand for the creation of a recycling-oriented society from the perspective of preserving the natural environment, and there is a desire to move away from dependence on fossil fuels, or to achieve carbon neutrality. As a result, the use of biomass-derived raw materials has attracted attention. Biomass is a renewable, organic resource derived from living organisms, excluding fossil fuels. Because biomass-derived raw materials do not affect the concentration of carbon dioxide in the atmosphere, carbon neutrality can be achieved by using biomass-derived raw materials.

[0004] As an example of a composition containing a biomass-derived base oil, Patent Document 1 discloses a hydraulic oil containing a biomass-derived base oil and an antioxidant.

[0005] International Publication No. 2015 / 192072

[0006] Although studies have been conducted to reduce the environmental impact of conventional hydraulic oils such as those described in Patent Document 1, the functions required of gas compressor oil compositions have not been verified. Gas compressor oil compositions are required to have high anti-foaming properties, carbon solubility, and wear resistance.

[0007] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a gas compressor oil composition that can preserve the natural environment while maintaining good defoaming properties, carbon solubility, and wear resistance.

[0008] In the course of their investigations, the present inventors have found that simply changing the base oil contained in a conventional gas compressor oil composition to a hydrocarbon base oil containing biomass-derived carbon reduces carbon solubility, making it easier for carbon generated by thermal degradation to accumulate.

[0009] In order to solve the above problems, the present invention employs the following configurations. [1] A gas compressor oil composition containing a hydrocarbon base oil (A1) having biomass-derived carbon and a degradation product solubilizer (B), wherein the content of biomass-derived carbon measured by ASTM D6866 is 20 mass% or more based on the total carbon content in the gas compressor oil composition. [2] The gas compressor oil composition according to [1], wherein the content of biomass-derived carbon measured by ASTM D6866 is 40 mass% or more based on the total carbon content in the gas compressor oil composition. [3] The gas compressor oil composition according to [1] or [2], wherein the degradation product solubilizer (B) comprises one or more oils selected from the group consisting of synthetic oils and mineral oils. [4] The gas compressor oil composition according to any one of [1] to [3], which is used in a reciprocating gas compressor. [5] The gas compressor oil composition according to any one of [1] to [4], further comprising an antioxidant. [6] The gas compressor oil composition according to [5], wherein the antioxidant contains an amine compound.

[0010] According to the present invention, it is possible to provide a gas compressor oil composition that can preserve the natural environment while maintaining good antifoaming properties, carbon solubility, and wear resistance.

[0011] (Gas compressor oil composition) The gas compressor oil composition of this embodiment is a composition used in a compressor that compresses gas. The gas compressor oil composition of this embodiment has a biomass-derived carbon content measured by ASTM D6866 of 20 mass% or more, preferably 40 mass% or more, more preferably 60 mass% or more, and even more preferably 80 mass% or more, based on the total carbon content in the gas compressor oil composition. There is no upper limit for the biomass-derived carbon content measured by ASTM D6866, but it may be 100 mass% or less, or may be 99 mass% or less.

[0012] ASTM D6866 (Biobased Content Testing Standard) is a standard established for determining the biobased content of solids, liquids, and gases using radiocarbon (C14) analysis. Since biomass contains a certain amount of radiocarbon (C14), raw materials derived from biomass also contain radiocarbon (C14). On the other hand, raw materials derived from fossil resources do not contain radiocarbon (C14). Therefore, the content of biomass-derived carbon can be calculated by measuring the radiocarbon (C14) concentration contained in a gas compressor oil composition.

[0013] The kinematic viscosity of the gas compressor oil composition of this embodiment at 40 ° C. is 30 mm ２ / s or more, and ２ / s or more is more preferable, and 50 mm ２ The kinematic viscosity of the gas compressor oil composition of this embodiment at 40°C is preferably 90 mm / s or more. ２ / s or less, and ２ / s or less is more preferable, and 70 mm ２ For example, the kinematic viscosity at 40°C of the gas compressor oil composition of this embodiment is 30 mm / s or less. ２ / s or more 90mm ２ / s or less, and ２ / s or more 80mm ２ / s or less is more preferable, and 50 mm ２ / s or more 70mm ２ It is more preferable that the ratio is 1 / s or less.

[0014] When the kinematic viscosity at 40°C of the gas compressor oil composition of this embodiment is equal to or greater than the above-mentioned preferred lower limit, the lubricity of the drive unit is further improved. When the kinematic viscosity at 40°C of the gas compressor oil composition of this embodiment is equal to or less than the above-mentioned preferred upper limit, the cooling efficiency in the compression unit is further improved. Furthermore, when the kinematic viscosity at 40°C of the gas compressor oil composition of this embodiment is equal to or less than the above-mentioned preferred upper limit, the circulation efficiency is improved, and the power consumption of the pump that circulates the gas compressor oil composition can be further reduced.

[0015] The kinematic viscosity of the gas compressor oil composition of this embodiment at 100°C is 1.0 mm ２ / s or more, and 3.0 mm ２ / s or more is more preferable, and 5.0 mm ２ The kinematic viscosity of the gas compressor oil composition of this embodiment at 100°C is preferably 25 mm / s or more. ２ / s or less, and ２ / s or less is more preferable, and 15 mm ２ For example, the kinematic viscosity at 100°C of the gas compressor oil composition of this embodiment is 1.0 mm / s or less. ２ / s or more 25mm ２ / s or less, and 3.0 mm ２ / s or more 20mm ２ / s or less, and more preferably 5.0 mm ２ / s or more 15mm ２ It is more preferable that the ratio is 1 / s or less.

[0016] When the kinematic viscosity at 100°C of the gas compressor oil composition of this embodiment is equal to or greater than the above-mentioned preferred lower limit, the lubricity of the drive unit is further improved. When the kinematic viscosity at 100°C of the gas compressor oil composition of this embodiment is equal to or less than the above-mentioned preferred upper limit, the cooling efficiency in the compression unit is further improved. Furthermore, when the kinematic viscosity at 100°C of the gas compressor oil composition of this embodiment is equal to or less than the above-mentioned preferred upper limit, the circulation efficiency is improved, and the power consumption of the pump that circulates the gas compressor oil composition can be further reduced.

[0017] The viscosity index of the gas compressor oil composition of this embodiment is preferably 120 or more, more preferably 130 or more, and even more preferably 140 or more.

[0018] When the viscosity index of the gas compressor oil composition of this embodiment is equal to or greater than the above-mentioned preferable lower limit, the range of change in kinematic viscosity due to temperature change becomes small, and thus the lubricity at high temperatures is further improved.

[0019] The upper limit of the viscosity index of the gas compressor oil composition of this embodiment is not particularly limited, and is, for example, preferably not more than 200, more preferably not more than 180, and even more preferably not more than 150. For example, the viscosity index of the gas compressor oil composition of this embodiment is preferably 120 or more and 200 or less, more preferably 130 or more and 180 or less, and even more preferably 140 or more and 150 or less.

[0020] In this specification, the kinematic viscosity at 40°C and 100°C and the viscosity index respectively refer to values ​​measured in accordance with JIS K2283:2000 "Crude oil and petroleum products - Test method for kinematic viscosity and calculation method for viscosity index."

[0021] The density of the gas compressor oil composition of this embodiment at 15 ° C. is 0.60 g / cm ３ It is preferable that the density is 0.70 g / cm or more. ３ More preferably, it is 0.80 g / cm or more. ３ The density of the gas compressor oil composition of this embodiment at 15°C is more preferably 1.10 g / cm or more. ３ Preferably, it is 1.00 g / cm or less. ３ More preferably, it is 0.90 g / cm or less. ３ For example, the density of the gas compressor oil composition of this embodiment at 15°C is 0.60 g / cm or less. ３ 1.10g / cm or more ３ Preferably, it is 0.70 g / cm or less. ３ 1.00g / cm or more ３ More preferably, it is 0.80 g / cm or less. ３ 0.90g / cm or more ３ It is even more preferable that:

[0022] In this specification, the density at 15°C means a value measured in accordance with JIS K2249:2011.

[0023] <Base oil (A)> The kinematic viscosity of the base oil (A) at 40°C is 30 mm ２ / s or more, and ２ / s or more is more preferable, and 50 mm ２ The kinematic viscosity of the base oil (A) at 40°C is preferably 90 mm / s or more. ２ / s or less, and ２ / s or less is more preferable, and 70 mm ２ For example, the kinematic viscosity of the base oil (A) at 40°C is 30 mm / s or less. ２ / s or more 90mm ２ / s or less, and ２ / s or more 80mm ２ / s or less is more preferable, and 50 mm ２ / s or more 70mm ２ It is more preferable that the ratio is 1 / s or less.

[0024] When the kinematic viscosity at 40°C of the base oil (A) of the gas compressor oil composition of this embodiment is equal to or greater than the above-mentioned preferred lower limit, the lubricity of the drive unit is further improved. When the kinematic viscosity at 40°C of the base oil (A) of the gas compressor oil composition of this embodiment is equal to or less than the above-mentioned preferred upper limit, the cooling efficiency in the compression unit is further improved. Furthermore, when the kinematic viscosity at 40°C of the gas compressor oil composition of this embodiment is equal to or less than the above-mentioned preferred upper limit, the circulation efficiency is improved, and the power consumption of the pump that circulates the gas compressor oil composition can be further reduced.

[0025] The base oil (A) contains a hydrocarbon base oil (A1) having carbon derived from biomass.

[0026] <Hydrocarbon Base Oil (A1) Having Biomass-Derived Carbon> Specific examples of the hydrocarbon base oil (A1) having biomass-derived carbon (hereinafter also referred to as "component (A1)") include hydrocarbon base oils synthesized from vegetable oils such as palm oil, coconut oil, soybean oil, rapeseed oil, corn oil, and mixtures thereof.

[0027] Commercially available examples of component (A1) include SynNova 4 Base Oil (manufactured by Novvi), SynNova 9 Base Oil (manufactured by Novvi), and NovaSolv 160 (manufactured by Novvi).

[0028] The content of biomass-derived carbon in the component (A1), as measured by ASTM D6866, is preferably 20% by mass or more, more preferably 60% by mass or more, even more preferably 80% by mass or more, and particularly preferably 100% by mass.

[0029] The kinematic viscosity of component (A1) at 40°C is 5.0 mm ２ / s or more, and 10 mm ２ / s or more is more preferable, and 15 mm ２ The kinematic viscosity of component (A1) at 40°C is preferably 75 mm / s or more. ２ / s or less, and ２ / s or less is more preferable, and 65 mm ２ For example, the kinematic viscosity of component (A1) at 40°C is 5.0 mm / s or less. ２ / s or more 75mm ２ / s or less, and ２ / s or more 70mm ２ / s or less is more preferable, and 15 mm ２ / s or more 65mm ２ It is more preferable that the ratio is 1 / s or less.

[0030] When the kinematic viscosity of component (A1) at 40°C is equal to or greater than the above-mentioned preferred lower limit, the lubricity of the drive unit is further improved. When the kinematic viscosity of component (A1) at 40°C is equal to or less than the above-mentioned preferred upper limit, the cooling efficiency in the compression unit is further improved. Furthermore, when the kinematic viscosity of component (A1) at 40°C is equal to or less than the above-mentioned preferred upper limit, the circulation efficiency is improved, thereby enabling a further reduction in the power consumption of the pump that circulates the gas compressor oil composition.

[0031] In the gas compressor oil composition of this embodiment, the component (A1) may be used alone, or a mixture of multiple components (A1) may be used. The content of the component (A1) is preferably 80 mass% or more, more preferably 90 mass% or more, and even more preferably 93 mass% or more, based on the total amount of the base oil (A). In the gas compressor oil composition of this embodiment, the base oil (A) may consist solely of the component (A1).

[0032] The content of component (A1) is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 93% by mass or more, relative to the total amount of the gas compressor oil composition of this embodiment. The content of component (A1) is preferably 99% by mass or less, more preferably 98% by mass or less, and even more preferably 96% by mass or less, relative to the total amount of the gas compressor oil composition of this embodiment. For example, the content of component (A1) is preferably 80% by mass or more and 99% by mass or less, more preferably 90% by mass or more and 98% by mass or less, and even more preferably 93% by mass or more and 96% by mass or less, relative to the total amount of the gas compressor oil composition of this embodiment.

[0033] <<Deterioration Product Dissolver (B)>> The gas compressor oil composition of this embodiment contains a deterioration product dissolver (B) (hereinafter also referred to as "component (B)"). Here, the deterioration product refers to carbon and the like that is generated by thermal degradation of the gas compressor oil composition of this embodiment when the gas compressor oil composition is used to operate a gas compressor for an extended period of time. The component (B) in the gas compressor oil composition of this embodiment is not particularly limited as long as it is a solvent that can dissolve the carbon, and examples thereof include synthetic oils other than the above-mentioned component (A1) and mineral oils.

[0034] Synthetic Oils 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.

[0035] Mineral Oils Mineral oils can be distillates obtained by atmospheric distillation of crude oil. Furthermore, lubricating oil fractions obtained by further vacuum distillation of the distillate and then refining the distillate through various refining processes can also be used. Refining processes can include hydrorefining, solvent extraction, solvent dewaxing, hydrodewaxing, sulfuric acid washing, and clay treatment, and can be combined as appropriate. Mineral oils can be obtained by combining these refining processes in an appropriate order. Alternatively, a mixture of refined oils with different properties obtained by subjecting different crude oils or distillate oils to a combination of different refining processes can also be used.

[0036] The mineral oil may be a Group I base oil (hereinafter referred to as "API Group I base oil"), a Group II base oil (hereinafter referred to as "API Group II base oil"), or a Group III base oil (hereinafter referred to as "API Group III base oil") of the API base oil classification, or a mixture thereof. API Group I base oils are mineral base oils having a sulfur content of more than 0.03 mass% and / or a saturated content of less than 90 mass%, and a viscosity index of 80 to less than 120. API Group II base oils are mineral base oils having a sulfur content of 0.03 mass% or less, a saturated content of 90 mass% or more, and a viscosity index of 80 to less than 120. API Group III base oils are mineral base oils having a sulfur content of 0.03 mass% or less, a saturated content of 90 mass% or more, and a viscosity index of 120 or more.

[0037] Among the above, mineral oils are preferred as the degradation product dissolving agent for the gas compressor oil composition of this embodiment, and API Group I base oils are more preferred.

[0038] In the gas compressor oil composition of this embodiment, the component (B) may be used alone, or a mixture of multiple components (B) may be used. The content of the component (B) is preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 4% by mass or more, relative to the total amount of the gas compressor oil composition of this embodiment. The content of the component (B) is preferably 55% by mass or less, more preferably 30% by mass or less, and even more preferably 10% by mass or less, relative to the total amount of the gas compressor oil composition of this embodiment. For example, the content of the component (B) is preferably 1% by mass or more and 55% by mass or less, more preferably 2% by mass or more and 30% by mass or less, and even more preferably 4% by mass or more and 10% by mass or less, relative to the total amount of the gas compressor oil composition of this embodiment.

[0039] <Optional Components> The gas compressor oil composition of this embodiment may contain optional components other than the base oil components (A) and (B) described above. Examples of the optional components include antioxidants, rust inhibitors, antifoaming agents, antiwear or extreme pressure agents, pour point depressants, and metal-based detergents.

[0040] <<Antioxidant>> Examples of the antioxidant include phenolic compounds and amine compounds. Specific examples of the phenolic compounds include 2,6-di-t-butylphenol and 2,6-di-t-butyl-p-cresol. Examples of the amine compounds include phenyl-α-naphthylamine, diphenylamine, dialkyldiphenylamine, and p-alkylphenyl-α-naphthylamine.

[0041] Phenyl-α-naphthylamine Examples of phenyl-α-naphthylamine include compounds represented by the following general formula (1).

[0042] [In formula (1), R １ represents a hydrogen atom or a linear or branched alkyl group having 1 to 16 carbon atoms.

[0043] R １Examples of the linear or branched alkyl group having 1 to 16 carbon atoms in the formula (I) include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, and a hexadecyl group (these alkyl groups may be linear or branched).

[0044] The phenyl-α-naphthylamine represented by general formula (1) may be a commercially available product or a synthetic product. The synthetic product can be easily synthesized by reacting phenyl-α-naphthylamine with a halogenated alkyl 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 Friedel-Crafts catalyst. Examples of the Friedel-Crafts catalyst that can be used include metal halides such as aluminum chloride, zinc chloride, and iron chloride; and acidic catalysts such as sulfuric acid, phosphoric acid, phosphorus pentoxide, boron fluoride, acid clay, and activated clay.

[0045] The gas compressor oil composition of this embodiment may use a single antioxidant, or may use a mixture of multiple antioxidants. The content of the antioxidant is preferably 0.05 mass% or more, more preferably 0.1 mass% or more, and even more preferably 0.3 mass% or more, relative to the total amount of the gas compressor oil composition of this embodiment. The content of the antioxidant is preferably 2.0 mass% or less, more preferably 1.5 mass% or less, and even more preferably 1.0 mass% or less, relative to the total amount of the gas compressor oil composition of this embodiment. For example, the content of the antioxidant is preferably 0.05 mass% or more and 2.0 mass% or less, more preferably 0.1 mass% or more and 1.5 mass% or less, and even more preferably 0.3 mass% or more and 1.0 mass% or less, relative to the total amount of the gas compressor oil composition of this embodiment.

[0046] When the content of the antioxidant is equal to or greater than the above-mentioned preferable lower limit, the oxidation stability and thermal stability are further improved. When the content of the antioxidant is equal to or less than the above-mentioned preferable upper limit, the generation of sludge can be further reduced.

[0047] <Rust Inhibitor> Examples of the rust inhibitor include alkenyl succinic acid, petroleum sulfonate, alkylbenzene sulfonate, dinonylnaphthalene sulfonate, and polyhydric alcohol ester (such as sorbitan monooleate).

[0048] The gas compressor oil composition of this embodiment may use a single rust inhibitor, or may use a mixture of multiple rust inhibitors. The content of the rust inhibitor is preferably 0.001 mass% or more, more preferably 0.005 mass% or more, and even more preferably 0.01 mass% or more, relative to the total amount of the gas compressor oil composition of this embodiment. The content of the rust inhibitor is preferably 1.0 mass% or less, more preferably 0.5 mass% or less, and even more preferably 0.1 mass% or less, relative to the total amount of the gas compressor oil composition of this embodiment. For example, the content of the rust inhibitor is preferably 0.001 mass% or more and 1.0 mass% or less, more preferably 0.005 mass% or more and 0.5 mass% or less, and even more preferably 0.01 mass% or more and 0.1 mass% or less, relative to the total amount of the gas compressor oil composition of this embodiment.

[0049] When the content of the rust inhibitor is equal to or greater than the above-mentioned preferable lower limit, the rust prevention property is further improved, and when the content of the rust inhibitor is equal to or less than the above-mentioned preferable upper limit, the oxidation stability is further improved.

[0050] <<Antifoaming Agent>> Examples of the antifoaming agent include silicone-based antifoaming agents, etc. Examples of the silicone-based antifoaming agent include dimethylpolysiloxane and trimethylsiloxy-terminated dimethylsiloxane.

[0051] The gas compressor oil composition of this embodiment may use a single antifoaming agent, or may use a mixture of multiple antifoaming agents. The content of the antifoaming agent is preferably 0.00001 mass% or more, more preferably 0.00003 mass% or more, and even more preferably 0.00005 mass% or more, relative to the total amount of the gas compressor oil composition of this embodiment. The content of the antifoaming agent is preferably 0.001 mass% or less, more preferably 0.0008 mass% or less, and even more preferably 0.0005 mass% or less, relative to the total amount of the gas compressor oil composition of this embodiment. For example, the content of the antifoaming agent is preferably 0.00001 mass% or more and 0.001 mass% or less, more preferably 0.00003 mass% or more and 0.0008 mass% or less, and even more preferably 0.00005 mass% or more and 0.0005 mass% or less, relative to the total amount of the gas compressor oil composition of this embodiment.

[0052] <<Anti-wear Agent or Extreme Pressure Agent>> Examples of the anti-wear agent or extreme pressure agent include organic zinc compounds such as zinc dialkyldithiophosphate and zinc dialkyldithiocarbamate; sulfur-containing compounds such as molybdenum dialkyldithiocarbamate, dihydrocarbyl polysulfide, sulfurized ester, thiazole compounds, and thiadiazole compounds; and phosphorus-based extreme pressure agents such as phosphate esters, acidic phosphate esters, amine salts of acidic phosphate esters, and phosphite esters.

[0053] As the phosphorus-based extreme pressure agent, phosphate ester, acid phosphate ester, amine salt of acid phosphate ester, chlorinated phosphate ester, phosphite ester, and phosphorothionate are preferably used. Specific examples of the phosphate ester include tributyl phosphate, tripentyl phosphate, trihexyl phosphate, triheptyl phosphate, trioctyl phosphate, trinonyl phosphate, tridecyl phosphate, triundecyl phosphate, tridodecyl phosphate, tritridecyl phosphate, tritetradecyl phosphate, tripentadecyl phosphate, trihexadecyl phosphate, triheptadecyl phosphate, trioctadecyl phosphate, trioleyl phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, and xylenyl diphenyl phosphate, with tricresyl phosphate being preferred.

[0054] The gas compressor oil composition of this embodiment may use one anti-wear agent and one extreme pressure agent alone, or may use a mixture of multiple anti-wear agents and extreme pressure agents. The content of the anti-wear agent and the extreme pressure agent is preferably 0.01 mass% or more, more preferably 0.05 mass% or more, and even more preferably 0.1 mass% or more, relative to the total amount of the gas compressor oil composition of this embodiment. The content of the anti-wear agent and the extreme pressure agent is preferably 2.0 mass% or less, more preferably 1.5 mass% or less, and even more preferably 1.0 mass% or less, relative to the total amount of the gas compressor oil composition of this embodiment. For example, the content of the anti-wear agent and the extreme pressure agent is preferably 0.01 mass% or more and 2.0 mass% or less, more preferably 0.05 mass% or more and 1.5 mass% or less, and even more preferably 0.1 mass% or more and 1.0 mass% or less, relative to the total amount of the gas compressor oil composition of this embodiment.

[0055] When the content of the anti-wear agent and the extreme pressure agent is equal to or greater than the above-mentioned preferable lower limit, the wear resistance is further improved. When the content of the anti-wear agent and the extreme pressure agent is equal to or less than the above-mentioned preferable upper limit, the demulsibility is further improved and the generation of sludge can be further suppressed.

[0056] <<Pour Point Depressant>> Examples of pour point depressants include polymethacrylate polymers that are compatible with the base oil (A).

[0057] <Metallic Detergents> Examples of metallic detergents include normal salts or basic salts of alkali metals or alkaline earth metals, such as sulfonates, phenates, and salicylates. From the viewpoint of neutralizing lower fatty acids and thereby suppressing their evaporation, metallic detergents are preferably basic salts of alkali metals or alkaline earth metals, such as sulfonates, phenates, and salicylates. Examples of alkaline metals include preferably sodium and potassium. Examples of alkaline earth metals include preferably magnesium, calcium, and barium. Among these metals, magnesium or calcium is preferred, and calcium is more preferred. Specific examples include branched-chain sulfurized alkylphenol calcium.

[0058] The gas compressor oil composition of this embodiment has high antifoaming properties, carbon solubility, and wear resistance, and is therefore particularly useful as a gas compressor oil composition for reciprocating gas compressors, which are devices that compress gas by reciprocating pistons in a cylinder.

[0059] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0060] <Blending of Gas Compressor Oil Compositions> The gas compressor oil compositions of Examples 1 and 2 and the gas compressor oil compositions of Comparative Examples 1 and 2 were prepared by blending the respective components in the blending ratios shown in Table 1. In Table 1, the numerical value of each component means the content (% by mass) relative to the total amount of the gas compressor oil composition. Furthermore, the gas compressor oil compositions of Examples 3 to 7 and the gas compressor oil composition of Comparative Example 3 were prepared by blending the respective components in the blending ratios shown in Table 2. In Table 2, the contents of A1-1, A1-2, B-1, B-2, and B-3 indicate the proportion (% by mass) of each component relative to the total amount of A1-1, A1-2, B-1, B-2, and B-3. The contents (% by mass) of components other than A1-1, A1-2, B-1, B-2, and B-3 refer to the content (% by mass) relative to the total amount of the gas compressor oil composition. Therefore, the content of A1-1, A1-2, B-1, B-2, and B-3 is the value obtained by subtracting the total content (mass%) of components other than A1-1, A1-2, B-1, B-2, and B-3 from 100 mass%.

[0061] A1-1: 100% plant-derived hydrocarbon lubricating base oil (product name "SynNova 9 Base Oil", manufactured by Novvi, kinematic viscosity at 40 ° C: 57.15 mm ２ / s, 100℃ kinematic viscosity: 9.398mm ２ / s, viscosity index: 147). A1-2: 100% plant-derived hydrocarbon lubricating base oil (product name "SynNova 4 Base Oil", manufactured by Novvi, kinematic viscosity at 40°C: 19.74 mm ２ / s, 100℃ Kinematic viscosity: 4.382mm ２ / s, viscosity index: 135).

[0062] B-1: API Group I base oil (kinematic viscosity at 40°C: 460.3 mm ２ / s, 100℃ kinematic viscosity: 31.09mm ２ / s, viscosity index: 98). B-2: Ester oil (product name "Priolube 2046", manufactured by Cargill, kinematic viscosity at 40°C: 392.6 mm ２ / s, 100℃ kinematic viscosity: 39.84mm ２ / s, viscosity index: 151). B-3: API Group I base oil (40°C kinematic viscosity: 95.92 mm ２ / s, 100℃ kinematic viscosity: 10.92mm ２ / s, viscosity index: 98). X-1: Dimethylpolysiloxane X-2: Zinc alkaryl dithiophosphate, zinc alkyl dithiophosphate (55:45 mixture) X-3: Calcium alkylphenol sulfide X-4: N-(dodecylphenyl)-naphthalene-1-amine X-5: Tricresyl phosphate

[0063] <Evaluation of properties of gas compressor oil compositions> The results of evaluation of the properties of the gas compressor oil compositions of Examples 1 to 7 and the gas compressor oil compositions of Comparative Examples 1 to 3 are shown in Tables 1 and 2. The physical properties shown in Tables 1 and 2 were determined according to the test methods shown below. In Table 2, "-" means that no evaluation was performed.

[0064] Biobased content: ASTM D6866 Density: JIS K2249-1:2011 Flash point (COC: Cleveland open cup): JIS K2265-4:2007 Kinematic viscosity: JIS K2283:2000 Viscosity index: JIS K2283:2000 Acid number: JIS K2501:2003 ASTM color: JIS K2580:2003 Pour point: JIS K2269:1987 Carbon solubility (panel coking): as described below Abrasion resistance: JIS K2518:2017

[0065] [Evaluation of Carbon Solubility] 300 mL of each gas compressor oil composition was placed in a test vessel equipped with a splasher, and an aluminum panel was attached. The gas compressor oil composition was heated to 100°C, and the panel was heated to a predetermined temperature (250°C or 270°C). Once the predetermined temperature was reached, the splasher was rotated at 1000 rpm to splash the oil onto the panel. The splashing was performed in a cycle of 15 seconds followed by a 45-second pause. After 3 hours, the mass (mg) of carbon and other substances adhering to the aluminum panel was measured. A lower numerical value indicates better carbon solubility.

[0066]

[0067]

[0068] As shown in Tables 1 and 2, the gas compressor oil compositions of Examples 1 to 7, which contained both the hydrocarbon base oil (A1) and the degradation product dissolving agent (B), had better carbon solubility evaluation results than the gas compressor oil compositions of Comparative Examples 1 and 2, which contained only the hydrocarbon base oil (A1). The gas compressor oil composition of Comparative Example 3, which contained only the degradation product dissolving agent (B), had a low bio-based degree.

[0069] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments. Addition, omission, substitution, and other modifications of the configuration are possible within the scope of the spirit of the present invention. The present invention is not limited by the above description, but is limited only by the scope of the appended claims.

Claims

1. A gas compressor oil composition comprising a base oil (A) and a degradation product dissolving agent (B), wherein the base oil (A) comprises a hydrocarbon base oil (A1) having biomass-derived carbon, and the content of biomass-derived carbon as measured by ASTM D6866 is 20 mass% or more based on the total carbon in the gas compressor oil composition.

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

3. The gas compressor oil composition according to claim 1 or 2, wherein the deterioration product dissolving agent (B) is one or more oils selected from the group consisting of synthetic oils and mineral oils.

4. A gas compressor oil composition according to claim 1 or 2, which is used in a reciprocating type gas compressor.

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

6. The gas compressor oil composition according to claim 5, wherein the antioxidant comprises an amine compound.

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