Lubricating oil composition

Abstract

This lubricating oil composition contains a base oil (A) and an oily agent (C). The base oil (A) includes a base oil (A1) having biomass-derived carbon (excluding synthetic oils obtained from biomass raw materials by using a Fischer-Tropsch reaction). The oily agent (C) includes one or more oily agents selected from alcohols and esters other than phosphate esters. The content of the biomass-derived carbon, as measured using ASTM D6866, is at least 20% based on the total carbon in the lubricating oil composition.

Description

lubricating oil composition

[0001] The present invention relates to a lubricating oil composition. This application claims priority to Japanese Patent Application No. 2022-059838, filed on March 31, 2022, the contents of which are incorporated herein by reference.

[0002] Lubricating oils are generally used to lubricate mechanical elements and are used in many mechanical devices. Depending on their intended use, lubricating oils are classified into hydraulic oils, turbine oils, lubricating oils for looms, metalworking oils (specifically, plastic processing oils such as rolling oils, cutting oils, punching oils, and press oils), etc. For example, hydraulic oils are oils used as a power transmission medium in hydraulic devices. Hydraulic oils also serve as lubricants for the sliding parts of hydraulic devices. Meanwhile, metalworking oils are oils used for the purposes of suppressing wear and preventing seizure during processing, improving productivity by increasing processing speeds, cooling, etc.

[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 lubricating oil 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 lubricating oil compositions such as those described in Patent Document 1, their lubricating oil properties are comparable to or inferior to those of lubricating oil compositions using fossil resources such as mineral oil, and there is room for improvement. Therefore, a lubricating oil composition with improved lubricating oil properties while reducing the environmental impact is desired. When the lubricating oil is a hydraulic oil, specific lubricating oil properties required include low friction, wear resistance, oxidation stability, thermal stability, rust prevention, antifoaming properties, water separation properties, compatibility with organic materials (does not cause swelling of seals, packings, etc.), and a high flash point. Furthermore, when the lubricating oil is a metal processing oil, specific lubricating oil properties required include processability, seizure resistance, low friction, thermal degreasing properties (easily evaporates when heated), wear resistance, anti-discoloration effect on copper and aluminum, rust prevention for materials mainly composed of iron, oxidation stability, etc.

[0007] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a lubricating oil composition which conserves the natural environment and has improved processability.

[0008] In order to solve the above problems, the present invention employs the following configurations. [1] A lubricating oil composition containing a base oil (A) and an oiliness agent (C), wherein the base oil (A) comprises a base oil (A1) having biomass-derived carbon (excluding synthetic oils obtained from biomass feedstocks by a Fischer-Tropsch reaction), and the oiliness agent (C) comprises one or more oiliness agents selected from esters other than phosphate esters and alcohols, wherein the content of biomass-derived carbon in the lubricating oil composition as measured by ASTM D6866 is 20% or more based on the total carbon in the lubricating oil composition. [2] The lubricating oil composition according to [1], wherein the content of biomass-derived carbon in the lubricating oil composition as measured by ASTM D6866 is 40% or more based on the total carbon in the lubricating oil composition. [3] The lubricating oil composition according to [1] or [2], further comprising a phosphate ester (B), wherein the phosphate ester (B) is a phosphate triester represented by the following general formula (P-1):

[0009] [In the formula, R １ ~R ３are each independently an aryl group which may have a substituent, or an alkyl group which may have a substituent.] [4] The lubricating oil composition according to any one of [1] to [3], wherein the oiliness agent (C) comprises an ester (C1) having 7 to 26 carbon atoms obtained from a monohydric alcohol and a monobasic acid or a monohydric alcohol (C2), and a polyalkylene glycol (C3).

[0010] According to the present invention, it is possible to provide a lubricating oil composition which is environmentally friendly and has improved processability.

[0011] FIG. 1 is an explanatory diagram showing an outline of a flat plate sliding test.

[0012] (Lubricating Oil Composition) The lubricating oil composition of this embodiment contains a base oil (A) and an oiliness agent (C). Specific examples of the lubricating oil composition of this embodiment include a lubricating oil composition containing the base oil (A) and the oiliness agent (C); and a lubricating oil composition containing the base oil (A), a phosphate ester (B), and an oiliness agent (C).

[0013] From the viewpoint of protecting the natural environment, the lubricating oil composition of this embodiment has a biomass-derived carbon content of 20% or more, preferably 40% or more, more preferably 60% or more, and even more preferably 80% or more, based on the total carbon content in the lubricating oil composition, as measured by ASTM D6866. There is no upper limit to the biomass-derived carbon content as measured by ASTM D6866, but it may be 100% or less, or may be 95% or less.

[0014] For example, the lubricating oil composition of the present embodiment preferably has a biomass-derived carbon content, measured according to ASTM D6866, of the total carbon in the lubricating oil composition of 20% or more and 100% or less, more preferably 40% or more and 100% or less, even more preferably 60% or more and 95% or less, and particularly preferably 80% or more and 95% or less.

[0015] ASTM D6866 (Biobased Content Testing Standard) is a standard established to determine 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 concentration of radiocarbon (C14) contained in a lubricating oil composition.

[0016] The content of biomass-derived carbon in the lubricating oil composition of this embodiment can be controlled, for example, by adjusting the content of the biomass-derived carbon-containing base oil (A1) described below.

[0017] When the lubricating oil composition of this embodiment is used as a hydraulic oil, the kinematic viscosity at 40°C is 10 mm ２ / s or more, and 15 mm ２ / s or more is more preferable, and 20 mm ２ The kinematic viscosity of the lubricating oil composition of this embodiment at 40°C is 100mm / 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 lubricating oil composition of this embodiment at 40°C is 10 mm / s or less. ２ / s or more 100mm ２ / s or less, and 15 mm ２ / s or more 80mm ２ / s or less is more preferable, and 20 mm ２ / s or more 70mm ２ It is more preferable that the ratio is 1 / s or less.

[0018] When the lubricating oil composition of this embodiment is used as a metal processing oil, the kinematic viscosity at 40°C is 1.0 mm ２ / s or more, and 1.5 mm ２ / s or more, and 2.0 mm ２The kinematic viscosity of the lubricating oil composition of this embodiment at 40°C is preferably 50 mm / s or more. ２ / s or less, and ２ / s or less is more preferable, and 45 mm ２ For example, the kinematic viscosity at 40°C of the lubricating oil composition of this embodiment is 1.0 mm / s or less. ２ / s or more 50mm ２ / s or less, and 1.5 mm ２ / s or more 45mm ２ / s or less, and more preferably 2.0 mm ２ / s or more 40mm ２ It is more preferable that the ratio is 1 / s or less.

[0019] When the kinematic viscosity at 40°C of the lubricating oil composition of this embodiment is equal to or less than the above-mentioned preferable upper limit, lubricating oil properties such as low friction, wear resistance, seizure resistance, compatibility with organic materials, and high flash point are improved. When the kinematic viscosity is equal to or greater than the above-mentioned preferable lower limit, lubricating oil properties such as thermal degreasing and fuel economy are improved. In addition, productivity is improved by increasing the processing speed.

[0020] In this specification, unless otherwise specified, the kinematic viscosity at 40°C means the kinematic viscosity at 40°C measured in accordance with JIS K2283:2000.

[0021] <Base oil (A)> The lubricating oil composition of this embodiment contains a base oil (A). When the lubricating oil composition of this embodiment is used as a hydraulic oil, the kinematic viscosity of the base oil (A) at 40°C is 10 mm ２ / s or more, and 15 mm ２ / s or more is more preferable, and 20 mm ２ The kinematic viscosity of the base oil (A) at 40°C is preferably 100 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 10 mm / s or less. ２ / s or more 100mm ２ / s or less, and 15 mm ２ / s or more 80mm ２ / s or less is more preferable, and 20 mm ２ / s or more 70mm ２ It is more preferable that the ratio is 1 / s or less.

[0022] When the lubricating oil composition of this embodiment is used as a metal working oil, the kinematic viscosity of the base oil (A) at 40°C is 1.0 mm ２ / s or more, and 1.5 mm ２ / s or more, and 2.0 mm ２ The kinematic viscosity of the base oil (A) at 40°C is preferably 50 mm / s or more. ２ / s or less, and ２ / s or less is more preferable, and 45 mm ２ For example, the kinematic viscosity of the base oil (A) at 40°C is 1.0 mm / s or less. ２ / s or more 50mm ２ / s or less, and 1.5 mm ２ / s or more 45mm ２ / s or less, and more preferably 2.0 mm ２ / s or more 40mm ２ It is more preferable that the ratio is 1 / s or less.

[0023] When the kinematic viscosity at 40°C of the base oil (A) of the lubricating oil composition of this embodiment is not more than the above-mentioned preferable upper limit, lubricating oil properties such as low friction, wear resistance, seizure resistance, compatibility with organic materials, and high flash point are improved. When it is not less than the above-mentioned preferable lower limit, lubricating oil properties such as thermal degreasing and fuel economy are improved. In addition, productivity is improved by increasing the processing speed.

[0024] The base oil (A) includes a base oil (A1) having carbon derived from biomass. However, the base oil (A1) may include a synthetic oil obtained from a biomass feedstock by a Fischer-Tropsch reaction, i.e., a synthetic oil containing CO and H obtained by gasifying a biomass feedstock. ２This does not include synthetic oils produced by converting crude oil into hydrocarbons using a catalytic Fischer-Tropsch reaction.

[0025] <<Base Oil (A1) Having Biomass-Derived Carbon>> Specific examples of the base oil (A1) having biomass-derived carbon (hereinafter also referred to as “component (A1)”) include base oils synthesized from vegetable oils such as palm oil, coconut oil, soybean oil, rapeseed oil, and mixtures thereof.

[0026] 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). As the base oil (A) of the lubricating oil composition of this embodiment, one type of component (A1) may be used alone, or a mixture of multiple components (A1) may be used.

[0027] 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.

[0028] When the lubricating oil composition of this embodiment is used as a hydraulic oil, the kinematic viscosity of component (A1) at 40°C is 10 mm ２ / s or more, and 15 mm ２ / s or more is more preferable, and 20 mm ２ The kinematic viscosity of component (A1) at 40°C is preferably 100 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 component (A1) at 40°C is 10 mm / s or less. ２ / s or more 100mm ２ / s or less, and 15 mm ２ / s or more 80mm ２ / s or less is more preferable, and 20 mm ２ / s or more 70mm２ It is more preferable that the ratio is 1 / s or less.

[0029] When the lubricating oil composition of this embodiment is used as a metal working oil, the kinematic viscosity of component (A1) at 40°C is 1.0 mm ２ / s or more, and 1.5 mm ２ / s or more is more preferable, and 2.0 mm ２ The kinematic viscosity of component (A1) at 40°C is preferably 50 mm / s or more. ２ / s or less, and ２ / s or less is more preferable, and 45 mm ２ For example, the kinematic viscosity of component (A1) at 40°C is 1.0 mm / s or less. ２ / s or more 50mm ２ / s or less, and 1.5 mm ２ / s or more 45mm ２ / s or less is more preferable, and 2.0 mm ２ / s or more 40mm ２ It is more preferable that the ratio is 1 / s or less.

[0030] When the kinematic viscosity at 40°C of component (A1) of the lubricating oil composition of this embodiment is equal to or less than the above-mentioned preferable upper limit, lubricating oil properties such as low friction, wear resistance, seizure resistance, compatibility with organic materials, and high flash point are improved. When it is equal to or greater than the above-mentioned preferable lower limit, lubricating oil properties such as thermal degreasing and fuel economy are improved. In addition, productivity is improved by increasing the processing speed.

[0031] The base oil (A) may contain a base oil (A2) other than the above-mentioned component (A1).

[0032] <<Base Oil (A2) Other than Component (A1)>> Specific examples of the base oil (A2) other than the above-mentioned component (A1) (hereinafter also referred to as “component (A2)”) include synthetic oils and mineral oils.

[0033] Synthetic Oils Examples of synthetic oils include polyolefins such as poly-α-olefins, alkylbenzenes, and alkylnaphthalenes.

[0034] Mineral Oils Mineral oils can be distillates obtained by atmospheric distillation of crude oil. Lubricating oil fractions obtained by further vacuum distillation of this distillate and refining it 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. 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.

[0035] As the component (A2), the above synthetic oils or mineral oils may be used alone, or a mixture of two or more synthetic oils or mineral oils may be used.

[0036] The proportion of component (A1) in base oil (A) of the lubricating oil composition of this embodiment is preferably 30 mass % or more, more preferably 40 mass % or more, and even more preferably 45 mass % or more, based on the total amount of base oil (A).

[0037] The content of the base oil (A) in the lubricating oil composition of this embodiment is preferably 85% by mass or more, more preferably 90% by mass or more, even more preferably 92% by mass or more, and particularly preferably 95% by mass or more, based on the total amount of the lubricating oil composition. The content of the base oil (A) in the lubricating oil composition of this embodiment is preferably 99.8% by mass or less, more preferably 99.5% by mass or less, based on the total amount of the lubricating oil composition. For example, the content of the base oil (A) in the lubricating oil composition of this embodiment is preferably 85% by mass or more and 99.8% by mass or less, more preferably 90% by mass or more and 99.8% by mass or less, more preferably 92% by mass or more and 99.8% by mass or less, and particularly preferably 95% by mass or more and 99.5% by mass or less, based on the total amount of the lubricating oil composition.

[0038] When the content of base oil (A) in the lubricating oil composition of this embodiment is within the above preferred range, processability is further improved.

[0039] <Oiliness Agent (C)> The oiliness agent (C) (hereinafter also referred to as "component (C)") of the lubricating oil composition of this embodiment contains one or more oiliness agents selected from esters and alcohols other than component (B) described below. Specific examples of esters other than component (B) described below include esters (C1) (hereinafter also referred to as "component (C1)") having 7 to 26 carbon atoms obtained from a monohydric alcohol and a monobasic acid. Specific examples of alcohols include monohydric alcohols (C2) (hereinafter also referred to as "component (C2)") and polyalkylene glycols (C3) (hereinafter also referred to as "component (C3)").

[0040] Component (C1): Ester having 7 to 26 carbon atoms obtained from a monohydric alcohol and a monobasic acid The component (C1) is an ester having 7 to 26 carbon atoms obtained from a monohydric alcohol and a monobasic acid.

[0041] Monohydric Alcohols Examples of monohydric alcohols used as raw materials for component (C1) include monohydric alcohols having 1 to 25 carbon atoms, and the monohydric alcohols may be linear or branched, saturated or unsaturated. Specific examples of monohydric alcohols include methanol, ethanol, propanol, butanol, octanol (capryl alcohol), nonanol, decanol (capric alcohol), undecanol, dodecanol (lauryl alcohol), tridecanol, tetradecanol (myristyl alcohol), pentadecanol, hexadecanol (cetyl alcohol), heptadecanol, octadecanol (stearyl alcohol), nonadecanol, eicosanol (arachidyl alcohol), heneicosanol, and docosanol (behenyl alcohol). linear saturated alcohols such as 2-ethylhexanol, isostearyl alcohol, 2-n-octyl-1-dodecanol; branched saturated alcohols such as cis-9-hexadecen-1-ol (palmitoleyl alcohol), 9E-octadecen-1-ol (elaidyl alcohol), cis-9-octadecen-1-ol (oleyl alcohol), 9Z,12Z-octadecadien-1-ol (linoleyl alcohol), and the like.

[0042] Monobasic Acids Examples of monobasic acids used as a raw material for the component (C1) include fatty acids, specifically fatty acids having 1 to 25 carbon atoms, which may be linear or branched, saturated or unsaturated. Of the above, fatty acids having 6 to 24 carbon atoms are preferred.

[0043] Specific preferred examples include linear saturated fatty acids such as n-hexanoic acid, n-heptanoic acid, n-octanoic acid (caprylic acid), n-nonanoic acid, n-decanoic acid (capric acid), n-undecanoic acid, n-dodecanoic acid (lauric acid), n-tridecanoic acid, n-tetradecanoic acid (myristic acid), n-pentadecanoic acid, n-hexadecanoic acid (palmitic acid), n-heptadecanoic acid, n-octadecanoic acid (stearic acid), n-icosanoic acid (arachidic acid), docosanoic acid (behenic acid), and tetracosanoic acid (lignoceric acid); isoheptanoic acid, isooctanoic acid, iso Examples of branched-chain saturated fatty acids include nonanoic acid, isodecanoic acid, isoundecanoic acid, isododecanoic acid, isotridecanoic acid, isotetradecanoic acid, isopentadecanoic acid, isohexadecanoic acid, isoheptadecanoic acid, isooctadecanoic acid, and isoicosanoic acid; unsaturated fatty acids include 9-tetradecenoic acid (myristoleic acid), 9-hexadecenoic acid (palmitoleic acid), 9-octadecenoic acid (oleic acid), eicosenoic acid, and linoleic acid (9,12-octadecadienoic acid); and naturally occurring fatty acids containing one or more of these fatty acids (for example, beef tallow and coconut oil).

[0044] Of the above, the component (C1) is preferably an ester (C11) having 13 to 22 carbon atoms obtained from a monohydric alcohol and a monobasic acid (hereinafter also referred to as the component (C11)). Specifically, the component (C11) is more preferably an ester having 13 to 22 carbon atoms obtained from a monohydric linear saturated alcohol and a linear saturated fatty acid, more preferably methyl laurate, ethyl laurate, propyl laurate, butyl laurate, pentyl laurate, hexyl laurate, heptyl laurate, octyl laurate, nonyl laurate, decyl laurate, methyl palmitate, ethyl palmitate, propyl palmitate, butyl palmitate, pentyl palmitate, and hexyl palmitate, and particularly preferably methyl laurate, butyl palmitate, and butyl stearate.

[0045] Component (C2): Monohydric Alcohol Component (C2) is a monohydric alcohol. Examples of component (C2) include the same monohydric alcohols as those used as raw materials for component (C1). Of these, component (C2) is preferably a monohydric alcohol (C21) having 12 to 14 carbon atoms (hereinafter also referred to as component (C21)), more preferably a monohydric alcohol having 12 or 14 carbon atoms, and even more preferably dodecanol (lauryl alcohol) or tetradecanol (myristyl alcohol).

[0046] Component (C3): Polyalkylene Glycol Specific examples of the component (C3) include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, and tripropylene glycol, with tripropylene glycol being preferred.

[0047] The component (C) in the lubricating oil composition of this embodiment may be used alone or in combination of two or more.

[0048] Among the above, from the viewpoint of suppressing the amount of wear powder generated during processing, component (C) in the lubricating oil composition of this embodiment is preferably a mixture of component (C3) with one or more oiliness agents selected from the group consisting of components (C1) and (C2), more preferably a mixture of component (C3) with one or more oiliness agents selected from the group consisting of components (C11) and (C21), and even more preferably a mixture of tripropylene glycol with one or more oiliness agents selected from the group consisting of butyl stearate, dodecanol (lauryl alcohol), and tetradecanol (myristyl alcohol).

[0049] The content of component (C) in the lubricating oil composition of this embodiment is preferably 1 mass% or more, more preferably 2 mass% or more, and even more preferably 3 mass% or more, based on the total amount of the lubricating oil composition. The content of component (C) is preferably 30 mass% or less, more preferably 20 mass% or less, and even more preferably 15 mass% or less, based on the total amount of the lubricating oil composition. For example, the content of component (C) is preferably 1 mass% or more and 30 mass% or less, more preferably 2 mass% or more and 20 mass% or less, and even more preferably 3 mass% or more and 15 mass% or less, based on the total amount of the lubricating oil composition.

[0050] When the content of component (C) relative to the total amount of the lubricating oil composition is within the above preferred range, processability is further improved.

[0051] <Phosphate Ester (B)> Examples of the phosphate ester (B) (hereinafter also referred to as "component (B)") in the lubricating oil composition of this embodiment include phosphate monoesters, phosphate diesters, phosphate triesters, and amine salts of these phosphate esters.

[0052] Among the above, the component (B) is preferably a phosphate triester, and more preferably a phosphate triester represented by the following general formula (P-1), from the viewpoint of further improving processability.

[0053] [In the formula, R １ ~R ３ are each independently an aryl group which may have a substituent, or an alkyl group which may have a substituent.

[0054] R in the above general formula (P-1) １ ~R ３ Examples of the aryl group in the formula (I) include a phenyl group and a naphthyl group.

[0055] The aryl group may have a substituent, and examples of the substituent include an alkyl group, an alkoxy group, and a hydroxy group. The alkyl group is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, and more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group.

[0056] R in the above general formula (P-1) １ ~R ３ The alkyl group in is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group.

[0057] The alkyl group may have a substituent, and examples of the substituent include an alkoxy group, a hydroxy group, etc. The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, and more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group.

[0058] R in the above general formula (P-1) １ ~R ３ may be different from each other, but are preferably all the same.

[0059] R in the above general formula (P-1) １ ~R ３ Among the above, each of the groups is preferably an aryl group which may have a substituent, and more preferably each of the groups is an aryl group which may have the same substituent.

[0060] Specific examples of component (B) include triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate, tris(isopropylphenyl)phosphate, tris(t-butylphenyl)phosphate, linear or branched chain tributyl phosphate, linear or branched chain tripentyl phosphate, linear or branched chain trihexyl phosphate, linear or branched chain triheptyl phosphate, linear or branched chain trioctyl phosphate, linear or branched chain trihex ... Nonyl phosphate, linear or branched tridecyl phosphate, linear or branched triundecyl phosphate, linear or branched tridodecyl phosphate, linear or branched tritridecyl phosphate, linear or branched tritetradecyl phosphate, linear or branched tripentadecyl phosphate, linear or branched trihexadecyl phosphate, linear or branched triheptadecyl phosphate, linear or branched trioctadecyl phosphate, and linear or branched trioleyl phosphate are included.

[0061] Of the above, tricresyl phosphate and triphenyl phosphate are preferred as component (B) of the lubricating oil composition of this embodiment, and tricresyl phosphate is more preferred. Component (B) of the lubricating oil composition of this embodiment may be used alone or in combination of two or more.

[0062] When the lubricating oil composition of this embodiment contains component (B), the content of component (B) in the lubricating oil composition of this embodiment is preferably 0.05 mass% or more, more preferably 0.1 mass% or more, and even more preferably 0.3 mass% or more, based on the total amount of the lubricating oil composition. The content of component (B) in the lubricating oil composition of this embodiment is preferably 2 mass% or less, more preferably 1.5 mass% or less, and even more preferably 1 mass% or less, based on the total amount of the lubricating oil composition. For example, the content of component (B) in the lubricating oil composition of this embodiment is preferably 0.05 mass% or more and 2 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 mass% or less, based on the total amount of the lubricating oil composition.

[0063] When the content of component (B) relative to the total amount of the lubricating oil composition is within the above preferred range, processability is further improved.

[0064] <Optional Components> The lubricating oil composition of this embodiment may contain optional components other than the base oil (A), component (B), and component (C) described above. Examples of the optional components include antioxidants, rust inhibitors, corrosion inhibitors, rust inhibitors, antifoaming agents, metal detergents, antiwear agents, viscosity index improvers, pour point depressants, mist inhibitors, and demulsifiers.

[0065] Examples of antioxidants include phenolic compounds such as 2,6-di-t-butylphenol and 2,6-di-t-butyl-p-cresol; and amine compounds such as diphenylamine, dialkyldiphenylamine, phenyl-α-naphthylamine, and p-alkylphenyl-α-naphthylamine. When the lubricating oil composition contains an antioxidant, the content thereof is, for example, 0.5 to 10 mass% based on the total amount of the lubricating oil composition. One type of antioxidant may be used alone, or multiple antioxidants may be used in combination.

[0066] As the corrosion inhibitor, known corrosion inhibitors such as benzotriazole-based compounds, tolyltriazole-based compounds, thiadiazole-based compounds, and imidazole-based compounds can be used. When the lubricating oil composition contains a corrosion inhibitor, the content thereof is, for example, 0.01 to 10 mass% based on the total amount of the lubricating oil composition. The corrosion inhibitor may be used alone, or multiple corrosion inhibitors may be used in combination.

[0067] Specific examples of the rust inhibitor include salts of fatty acids such as oleic acid, sulfonates such as dinonylnaphthalene sulfonate, partial esters of polyhydric alcohols such as sorbitan monooleate (excluding those corresponding to the oily agent (C)), amines and derivatives thereof, and the like.

[0068] Examples of the antifoaming agent include silicone-based antifoaming agents.

[0069] 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 suppressing their evaporation, the metallic detergent is preferably a basic salt of alkali metals or alkaline earth metals, such as sulfonates, phenates, and salicylates. Examples of alkaline metals include sodium and potassium. Examples of alkaline earth metals include magnesium, calcium, and barium. Among these metals, magnesium or calcium is preferred, and calcium is more preferred.

[0070] Examples of the anti-wear agent include dithiocarbamates, zinc dithiocarbamates, molybdenum dithiocarbamates, disulfides, polysulfides, sulfurized olefins, sulfurized oils and fats, and the like.

[0071] Examples of viscosity index improvers include non-dispersant or dispersant poly(meth)acrylate viscosity index improvers, non-dispersant or dispersant olefin-(meth)acrylate copolymer viscosity index improvers, styrene-maleic anhydride copolymer viscosity index improvers, and mixtures thereof.

[0072] Examples of pour point depressants include polymethacrylate polymers that are compatible with the base oil (A).

[0073] Examples of mist suppressants include ethylene-propylene copolymers, polymethacrylates, polyisobutylene, polybutene, etc. The average molecular weight of these compounds as mist suppressants is usually 10,000 to 8,000,000.

[0074] Examples of the demulsifier include polyalkylene glycol-based nonionic surfactants such as polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, and polyoxyethylene alkyl naphthyl ether.

[0075] The lubricating oil composition of the present embodiment described above contains component (A1) and component (C), and has a biomass-derived carbon content of 20% or more based on the total carbon content of the lubricating oil composition as measured by ASTM D6866. Because the biomass-derived carbon content of the lubricating oil composition of the present embodiment is 20% or more, the environmental impact is reduced. Furthermore, the lubricating oil composition of the present embodiment exhibits the following effects due to the synergistic effect of the combination of component (A1) and component (C). When the lubricating oil composition of the present embodiment is used as a hydraulic oil, it exhibits good low friction, wear resistance, oxidation stability, thermal stability, rust prevention, antifoaming properties, water separation properties, compatibility with organic materials (does not swell seals, packings, etc.), and a high flash point, and is particularly good in low friction and thermal stability. When the lubricating oil composition of the present embodiment is used as a metalworking oil, it exhibits good processability, anti-seizure properties, low friction, thermal degreasing properties (easy evaporation by heating), wear resistance, anti-tarnish effect on copper and aluminum, and oxidation stability, and is particularly good in processability.

[0076] The lubricating oil composition of the present embodiment has the above-mentioned effects and is therefore useful as a hydraulic oil, turbine oil, lubricating oil for looms, lubricating oil for compressors, and metalworking oil (specifically, rolling oil, cutting oil, press oil, etc.), and is particularly useful as a hydraulic oil and metalworking oil, and is more useful as a metalworking oil.

[0077] 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. In the following examples, the lubricating oil composition of the present embodiment was used as a metal working oil and evaluated.

[0078] <Metal processing oil blending> The metal processing oils of Examples 1 to 6 and Comparative Examples 1 to 5 were prepared by blending the components in the blending ratios shown in Tables 1 and 2. The values ​​in Tables 1 and 2 indicate the content (mass%) of each component relative to the total amount of the lubricating oil composition. The metal processing oils obtained in each example were evaluated as follows. The evaluation results are shown in Tables 1 and 2.

[0079] (1) Base oil (A) (A1)-1: 100% plant-derived lubricating base oil (product name “NovaSolv 160”, manufactured by Novvi, kinematic viscosity at 40°C: 2.8 mm ２ / s (kinematic viscosity is measured in accordance with ASTM D445)). (A2)-1: Mineral oil (product name "AF Solvent No. 4", manufactured by ENEOS Corporation, kinematic viscosity at 40°C: 2.4 mm ２ / s)

[0080] (2) Phosphate ester (B) (B)-1: Triphenyl phosphate

[0081] (3) Oily agent (C) (C11)-1: butyl stearate (C2)-1: lauryl alcohol (C2)-2: myristyryl alcohol (C3)-1: tripropylene glycol

[0082] (c)-1: Molybdenum disulfide (c)-2: Oleic acid

[0083] <Production of Metalworking Oil> The components shown in Tables 1 and 2 were mixed to prepare metalworking oils of the respective examples.

[0084] [Evaluation of Biobased Content] The biobased content of each hydraulic oil was calculated in accordance with ASTM D6866. First, the concentration of radioactive carbon (C14) contained in each metalworking oil was measured to calculate the content of biomass-derived carbon. Next, the biobased content of each metalworking oil was calculated from the content of biomass-derived carbon. A higher biobased content means a lower environmental impact. The results are shown in Tables 1 and 2.

[0085] [Evaluation of Workability] To evaluate the degree of adhesion, which is a problem when molding aluminum into a rectangular tube, an aluminum flat plate sliding test was conducted to evaluate the workability of each metalworking oil. FIG. 1 is an explanatory diagram showing an outline of the flat plate sliding test. In FIG. 1, a test piece 1 made of an aluminum alloy was immersed in the metalworking oil of each example before being subjected to the test. The test piece 1 was clamped between a pair of flat plate blocks 2a and 2b, and a predetermined load (hereinafter referred to as the "clamping load") was applied from the upper surface of the flat plate block 2a (arrow A in FIG. 1) and the test piece was pulled out horizontally (arrow B in FIG. 1). This operation was performed consecutively on 30 test pieces 1 for each metalworking oil. The detailed test conditions are as follows. After the test, the sliding surfaces of the 30 test pieces 1 and the flat plate blocks 2a and 2b were visually observed and evaluated according to the following criteria. The results are shown in Tables 1 and 2.

[0086] <Test conditions> Aluminum test piece: JIS A1050 material Flat blocks 2a and 2b: SKD-11, 450 mm (width) x 250 mm (length) x 400 mm (thickness), contact area with test piece 1: 10 mm x 250 mm Clamping load: 15 kN Pull-out speed: 300 mm / min Temperature of metalworking oil in each example during immersion application: 40°C ± 3°C Temperature of test piece 1 during test: 25°C ± 3°C Temperature of flat block: 25°C ± 3°C Number of test pieces 1 per type of metalworking oil: 30

[0087] <Evaluation conditions> A: No adhesion of the aluminum material was observed, and no scratches or the like were found on the surface of the 30th aluminum material. B: Although some adhesion of the aluminum material occurred on the sliding surface of the flat block, no scratches were found on the 30th aluminum material. C: Adhesion of the aluminum material occurred on the sliding surface of the flat block, and scratches were also found on the aluminum material, but 30 pieces could be pulled out. D: The test did not reach the 30th piece, and the material broke during the test.

[0088] [Evaluation of the amount of wear debris generated] To evaluate the amount of wear debris generated during aluminum machining, an aluminum plate sliding test was conducted. The test method and conditions were the same as those for the evaluation of processability. Eight aluminum test pieces were successively pulled out without polishing or cleaning the flat block 2a, 2b, and after the test, each of the eight test pieces was ultrasonically cleaned in n-hexane. The cleaning solution was filtered through a 0.1 μ filter, and the trapped material was dissolved in hydrochloric acid. The aluminum content of the trapped material was quantified by atomic absorption spectroscopy, and converted into the amount of aluminum per area of ​​the processed material, which was used as the amount of wear debris generated.

[0089]

[0090]

[0091] As shown in Tables 1 and 2, the metal working oils of the Examples had good processability. On the other hand, Comparative Example 1, which did not contain component (C), had poor processability, Comparative Example 2, which did not contain component (A1), had a low bio-based content, and Comparative Examples 3 and 4, which used the general-purpose component (c)-1 or (c)-2 as an oiliness agent instead of component (C), had poor processability. Therefore, it can be seen that the lubricating oil compositions of the Examples used as metal working oils had good processability and reduced environmental impact.

[0092] 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 lubricating oil composition comprising a base oil (A) and an oiliness agent (C), The base oil (A) comprises a base oil (A1) having carbon derived from biomass (excluding synthetic oils obtained from biomass raw materials by a Fischer-Tropsch reaction), The oily agent (C) includes one or more oily agents selected from esters other than phosphate esters and alcohols, A lubricating oil composition having a biomass-derived carbon content of 20% or more based on the total carbon in the lubricating oil composition as measured by ASTM D6866.

2. The oily agent (C) comprises one or more oily agents selected from the group consisting of an ester (C1) having 7 to 26 carbon atoms obtained from a monohydric alcohol and a monobasic acid, a monohydric alcohol (C2), and a polyalkylene glycol (C3); The lubricating oil composition according to claim 1, wherein the ester (C1) having 7 to 26 carbon atoms obtained from a monohydric alcohol and a monobasic acid comprises an ester having 13 to 22 carbon atoms obtained from a monohydric linear saturated alcohol and a linear saturated fatty acid.

3. 3. The lubricating oil composition according to claim 1, wherein the content of biomass-derived carbon measured by ASTM D6866 is 99.5% or more based on the total carbon in the lubricating oil composition.

4. Further, it contains a phosphate ester (B), 3. The lubricating oil composition according to claim 1, wherein the phosphate ester (B) is a phosphate triester represented by the following general formula (P-1): 【Chemistry 1】 [In the formula, R １ ~R ３ are each independently an aryl group which may have a substituent, or an alkyl group which may have a substituent.

5. 3. The lubricating oil composition according to claim 1, wherein the oiliness agent (C) comprises an ester (C1) having 7 to 26 carbon atoms obtained from a monohydric alcohol and a monobasic acid or a monohydric alcohol (C2), and a polyalkylene glycol (C3).

6. The lubricating oil composition of claim 2, wherein the ester (C1) having 7 to 26 carbon atoms obtained from a monohydric alcohol and a monobasic acid comprises one or more oiliness agents selected from the group consisting of methyl laurate, ethyl laurate, propyl laurate, butyl laurate, pentyl laurate, hexyl laurate, heptyl laurate, octyl laurate, nonyl laurate, decyl laurate, methyl palmitate, ethyl palmitate, propyl palmitate, butyl palmitate, pentyl palmitate, and hexyl palmitate.

7. The lubricating oil composition according to claim 1, wherein the oiliness agent (C) comprises a monohydric alcohol (C2) or an ester having 13 to 22 carbon atoms obtained from a monohydric linear saturated alcohol and a linear saturated fatty acid, and a polyalkylene glycol (C3).

8. The lubricating oil composition according to claim 1, wherein the oiliness agent (C) comprises a monohydric alcohol (C2).

9. The lubricating oil composition according to claim 1, wherein the oiliness agent (C) comprises a monohydric alcohol (C2) and a polyalkylene glycol (C3).

10. The lubricating oil composition of claim 1, wherein the oiliness agent (C) is a mixture of one or more oiliness agents selected from the group consisting of butyl stearate, dodecanol (lauryl alcohol), and tetradecanol (myristyl alcohol) and tripropylene glycol.

11. A lubricating oil composition according to claim 1 or 2, wherein the content of the oily agent (C) is 3 mass % or more and 15 mass % or less.

12. A lubricating oil composition according to claim 1 or 2, consisting essentially of a base oil (A), an oiliness agent (C), an antioxidant, and one or more additives selected from the group consisting of a phosphate ester (B), a rust inhibitor, a mist inhibitor, and a metal deactivator.

13. The lubricating oil composition of claim 1 or 2, wherein the base oil (A) comprises NovaSolv 160 manufactured by Novvi.

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