TW202330886A - Lubricating oil composition - Google Patents

Abstract

Provided is a lubricating oil composition which contains a base oil (A) and a compound (B) selected from among a carboxylic acid ester, a carboxylic acid, an alcohol and an ether, and which has a phase transition pressure of 70 MPa or less, as calculated using a prescribed procedure.

Description

Lubricating oil composition

The present invention relates to a lubricating oil composition.

Background technique Lubricating oil is used in various fields such as lubrication of sliding parts in various devices, cooling of heat-generating equipment such as engines, and metal processing for improving workability during metal processing. For example, Patent Document 1 describes a lubricating oil composition for plastic working such as stamping and cold forging that has excellent lubricity and can be used even under severe lubricating conditions. An oil composition comprising: 5-99% by mass of zinc dithiophosphate having a specific structure, 1-95% by mass of metal salt of sulfonic acid, and 0-80% by mass of base oil. Prior art literature patent documents

[Patent Document 1] Japanese Unexamined Patent Publication No. 2013-173957

Summary of the invention Under such circumstances, there is currently a need for a novel lubricating oil that can exhibit good performance in response to individual uses. means to solve problems

The present invention provides a lubricating oil composition comprising a base oil and a compound selected from carboxylic acid esters, carboxylic acids, alcohols and ethers, and the phase transition pressure calculated by a predetermined operation is adjusted to be below a predetermined value. That is, the present invention provides the following [1] to [13]. [1] A lubricating oil composition comprising a base oil (A) and a compound (B) selected from carboxylic acid esters, carboxylic acids, alcohols, and ethers, and the phase transition pressure calculated by the following operations (i) to (iv) 70MPa or less; ・Operation (i): Fill the aforementioned lubricating oil composition at 30°C in a columnar chamber with a fixed cross-sectional area; ・Operation (ii): After operation (i), through the plunger, The lubricating oil composition applies a load in the vertical direction, and when it is pushed in at a speed of 0.01mm/s, the pressure P (MPa) in the aforementioned chamber calculated from the load/sectional area is the horizontal axis, and the pushing force of the aforementioned plunger in the vertical direction is The insertion length Y (mm) is the vertical axis, and the correlation diagram of the pressure P in the aforementioned chamber and the insertion length Y of the aforementioned plunger is obtained; ・Operation (iii): In the correlation diagram obtained in operation (ii), From the pressure P in the chamber being 0 MPa to the pressure P in the chamber becoming n (MPa) (n is an integer greater than 1), calculate the tangent slope [ΔX/ΔY] at each point of 1 MPa in sequence; ・Operation (iv ): When the pressure P in the chamber changes from n-1 (MPa) to n (MPa), the pressure in the chamber when the change rate of the tangent slope [ΔX/ΔY] calculated by the following formula (1) exceeds 2% for the first time Pressure P, namely n (MPa) is the aforementioned phase transition pressure; Formula (1): Change rate (%) of tangent slope [ΔX/ΔY] = ([ΔX/ΔY] _n - [ΔX/ΔY] _n-1 )/ 1 (MPa) × 100 (in the above formula (1), [ΔX/ΔY] _n represents the tangent slope [ΔX/ΔY] at the point where the pressure P in the chamber in the aforementioned correlation diagram is n (MPa); [ΔX/ΔY]; ΔY] _n-1 represents the tangent slope [ΔX/ΔY] at the point where the pressure P in the chamber in the aforementioned correlation diagram is n-1 (MPa). [2] The lubricating oil composition according to [1], wherein the component (A) contains paraffinic mineral oil (A1). [3] The lubricating oil composition according to the above [1] or [2], wherein the total content of component (A) and component (B) is 70 to 100% by mass based on the total amount of the aforementioned lubricating oil composition. [4] The lubricating oil composition according to any one of the above [1] to [3], wherein the total content of other lubricating oil additives other than component (B) is less than 90 parts by mass relative to 100 parts by mass of the total component (B). parts by mass. [5] The lubricating oil composition according to any one of the above [1] to [4], wherein the content of the sulfur-based extreme pressure agent is less than 50 parts by mass relative to 100 parts by mass of the total amount of component (B). [6] The lubricating oil composition according to any one of [1] to [5] above, wherein the carboxylic acid ester is a saturated or unsaturated chain carboxylic acid ester, and the carboxylic acid is a saturated or unsaturated chain Carboxylic acid, the aforementioned alcohol is a saturated or unsaturated chain alcohol, and the aforementioned ether is a saturated or unsaturated chain ether. [7] The lubricating oil composition according to any one of [1] to [5] above, wherein the carboxylic acid ester is a saturated chain carboxylic acid ester, the carboxylic acid is a saturated chain carboxylic acid, and the alcohol is a saturated chain Alcohol, the aforementioned ether is a saturated chain ether. [8] The lubricating oil composition according to any one of the above-mentioned [1] to [7], wherein component (B) contains a compound represented by any one of the following general formulas (b-1) to (b-4) ; [chemical formula 1] (In the above formula, R ¹ , R ² and R ³ are each independently an alkyl group with 10 to 40 carbons; in addition, R ^a , R ^b and R ^c are each independently an alkyl group with 1 to 30 carbons; however, R The total carbon number of ^b and R ^c is 10 or more). [9] The lubricating oil composition according to any one of the above-mentioned [1] to [8], wherein the content of the component (B) is 1.0% by mass or more based on the total amount of the aforementioned lubricating oil composition. [10] The lubricating oil composition according to any one of [1] to [9] above, wherein the kinematic viscosity at 40° C. of the lubricating oil composition is 100 mm ² /s or less. [11] The lubricating oil composition according to any one of [1] to [10] above, further comprising a pour point depressant. [12] The lubricating oil composition according to any one of the above-mentioned [1] to [11], which is used in metal processing. [13] A lubricating oil consisting essentially of a compound (B) selected from carboxylic acid esters, carboxylic acids, alcohols, and ethers, and having a phase transition pressure calculated by the following operations (i) to (iv) below 70 MPa;・Operation (i): Fill the above-mentioned lubricating oil composition at 30°C in a columnar chamber with a fixed cross-sectional area; The load is applied in the vertical direction, and the pressure P (MPa) in the aforementioned chamber calculated from the load/sectional area when pushing in at a speed of 0.01mm/s is the horizontal axis, and the pushing length Y of the aforementioned plunger in the vertical direction is ( mm) is the vertical axis, and the correlation diagram of the pressure P in the aforementioned chamber and the pushing length Y of the aforementioned plunger is obtained; ・Operation (iii): In the correlation diagram obtained in operation (ii), from the From the pressure P of 0 MPa until the pressure P in the chamber becomes n (MPa) (n is an integer greater than 1), calculate the tangent slope [ΔX/ΔY] at each point of 1 MPa in sequence; ・Operation (iv): inside the chamber When the pressure P changes from n-1 (MPa) to n (MPa), the pressure P in the chamber when the change rate of the tangent slope [ΔX/ΔY] calculated by the following formula (1) exceeds 2% for the first time is n (MPa) is the aforementioned phase transition pressure; Formula (1): Change rate of tangent slope [ΔX/ΔY] (%)=([ΔX/ΔY] _n - [ΔX/ΔY] _n-1 )/1(MPa) ×100 (In the above formula (1), [ΔX/ΔY] _n represents the tangent slope [ΔX/ΔY] at the point where the pressure P in the chamber in the aforementioned correlation diagram is n (MPa); [ΔX/ΔY] _{n- 1} represents the slope of the tangent line [ΔX/ΔY] at the point where the pressure P in the chamber in the aforementioned correlation diagram is n-1 (MPa). [14] The lubricating oil according to the above [13], wherein the content of components other than component (B) is less than 1.0% by mass based on the total amount of the aforementioned lubricating oil. [15] The lubricating oil according to the above [13] or [14], which is used for metal processing. Invention effect

The lubricating oil composition or lubricating oil according to a preferred aspect of the present invention can exhibit good performance according to individual applications. For example, when the lubricating oil composition or lubricating oil according to a preferred aspect of the present invention is used as a metal working oil, good metal working properties can be exhibited.

form for carrying out the invention In the numerical range described in this specification, an upper limit and a lower limit can be combined arbitrarily. For example, when the numerical range is described as "preferably 30-100, more preferably 40-80", the range of "30-80" and the range of "40-100" are included in the numerical range described in this specification. In addition, for example, when the numerical range is described as "preferably 30 or more, more preferably 40 or more, or preferably 100 or less, more preferably 80 or less", the range of "30~80" and "40~100" The range is also included in the numerical range described in this specification. In addition, regarding the numerical range described in this specification, for example, the description of "60~100" means the range of "more than 60 (60 or more than 60) and less than 100 (100 or less than 100)".

In this specification, a dynamic viscosity and a viscosity index mean the value measured and calculated based on JISK2283:2000.

[Constitution of lubricating oil composition] The lubricating oil composition of the present invention comprises a base oil (A) and a compound (B) selected from carboxylic acid esters, carboxylic acids, alcohols and ethers, and the following operations (i) to (iv) ) The calculated phase change pressure is below 70MPa; ・Operation (i): Fill the aforementioned lubricating oil composition at 30°C in a columnar chamber with a fixed cross-sectional area; ・Operation (ii): After operation (i), pass through the column The plug exerts a load on the lubricating oil composition in the aforementioned chamber in the vertical direction, and the pressure P (MPa) in the aforementioned chamber calculated from the load/sectional area when it is pushed in at a speed of 0.01mm/s is the horizontal axis, and the vertical direction is The pushing length Y (mm) of the aforementioned plunger is the vertical axis, and the correlation diagram of the pressure P in the aforementioned chamber and the pushing length Y of the aforementioned plunger is obtained; ・Operation (iii): obtained in operation (ii) From the obtained correlation diagram, from the pressure P in the chamber to 0 MPa to the pressure P in the chamber becoming n (MPa) (n is an integer greater than 1), the slope of the tangent line [ΔX/ΔY at each point of 1 MPa is calculated in sequence. ]; Operation (iv): When the pressure P in the chamber changes from n-1 (MPa) to n (MPa), the rate of change of the tangent slope [ΔX/ΔY] calculated by the following formula (1) exceeds 2 for the first time The pressure P in the chamber at % time, ie n (MPa) is the aforementioned phase change pressure; Formula (1): Change rate of tangent slope [ΔX/ΔY] (%) = ([ΔX/ΔY] _n - [ΔX/ΔY ] _n-1 )/1(MPa)×100 (In the above formula (1), [ΔX/ΔY] _n represents the tangent slope [ΔX/ ΔY]; [ΔX/ΔY] _n-1 represents the tangent slope [ΔX/ΔY] at the point where the pressure P in the chamber in the aforementioned correlation diagram is n-1 (MPa).

The procedure for calculating the phase transition pressure through operations (i) to (iv) will be described below. Fig. 1 is a schematic diagram showing an example of the structure of a high pressure testing machine for measuring the phase transition pressure of a lubricating oil composition which is the object of measurement. In addition, the objects of measurement include not only lubricating oil compositions but also lubricating oils described later. In addition, FIG. 2 is a graph showing the correlation between the pressure P in the chamber and the plunger insertion length Y obtained after performing operations (i) to (iv) on the sample oil of Example 1, and the pressure relative to the pressure P in the chamber. The rate of change of the tangent slope [ΔX/ΔY].

The high pressure measuring and testing machine 1 shown in Fig. 1 has: a pressure vessel outer cylinder 11; a pressure vessel inner cylinder 12 inserted into the outer cylinder 11; a pair of plungers 13 inserted into the space portion of the inner cylinder 12; 13 surrounds the inner side of the inner cylinder 12 and will fill the columnar chamber 14 with the object to be measured; and the holding table 15 for holding these structural parts. First, the lubricating oil composition at 30° C. to be measured is filled in the columnar chamber 14 of the high pressure testing machine 1 in FIG. 1 as operation (i).

The operation (ii) is performed by applying a vertical load to the lubricating oil composition in the chamber 14 through the plunger 13 . In addition, the load may be applied using a compression tensile testing machine other than the high pressure testing machine 1 or the like. Obtain the pressure P (MPa) in the chamber 14 calculated from the load/sectional area when the load is applied and pushed in the vertical direction at a speed of 0.01mm/s, and the thrust length Y (mm) of the plunger 13 in the vertical direction related information. Next, a correlation diagram is prepared in which the pressure P (MPa) in the aforementioned chamber is taken as the horizontal axis, and the pushing length Y (mm) of the aforementioned plunger in the vertical direction is taken as the vertical axis. In FIG. 2, the graph indicated by the solid line corresponds to the "correlation graph".

In the correlation diagram obtained in operation (ii), from the pressure P in the chamber to 0 MPa to the pressure P in the chamber becoming n (MPa) (n is an integer greater than 1), calculate the points for each 1 MPa in sequence The tangent slope [ΔX/ΔY] of is used as operation (iii). In Fig. 2, the correlation diagram between the pressure P in the chamber and the insertion length Y is represented by a solid line when the pressure P in the chamber is within the range of 15~28MPa. In operation (iii), calculate the tangent slope [ΔX/ΔY] at the point marked for every 1 MPa of the pressure P in the chamber in Fig. 2 within the range of 15-28 MPa.

Calculate the change rate of the tangent slope [ΔX/ΔY] calculated from the following formula (1) when the pressure P in the chamber changes from n-1 (MPa) to n (MPa) as operation (iv). The dotted line in Fig. 2 shows the rate of change of the tangent slope [ΔX/ΔY]. For example, the rate of change of the tangent slope [ΔX/ΔY] when the pressure P in the chamber changes from 25 (MPa) to 26 (MPa) can be obtained from the tangent slope [ΔX/ΔY] at the point where the pressure P in the chamber is 26 MPa ΔY] ₂₆ , and the value of the tangent slope [ΔX/ΔY] ₂₅ at the point where the pressure P in the chamber is 25 MPa, use the above formula (1) to calculate ([ΔX/ΔY] ₂₆ -[ΔX/ΔY] ₂₅ )/1(MPa)×100 to calculate. According to the graph of the rate of change shown by the dotted line in Fig. 2, the aforementioned rate of change exceeds 2% when the pressure P in the chamber is between 25 MPa and 26 MPa. Therefore, the phase transition pressure of the sample oil was calculated as "26 MPa".

The lubricating oil composition according to one aspect of the present invention can improve lubricity in an environment where a high specific pressure is applied. Conventional lubricating oil compositions have problems in that the lubricating conditions become severe as the specific pressure increases, the oil film cannot be maintained, and the lubricity decreases. In contrast, the lubricating oil composition of an aspect of the present invention has been adjusted so that the phase transition pressure calculated by the above operations (i)~(iv) will be below the predetermined value, and it will be relatively early in the environment accompanied by an increase in specific pressure. Phase transformation occurs in stages to form a strong oil film, which can exhibit good lubricity.

Regarding the lubricating oil composition of one aspect of the present invention, from the viewpoint of making a lubricating oil composition that is easy to form a strong oil film at an early stage to improve lubricity, the phase transition pressure of the aforementioned lubricating oil composition is 70MPa or less, preferably 65MPa or less, more preferably 63MPa or less, more preferably 60MPa or less, more preferably 57MPa or less, more preferably 55MPa or less, more preferably 53MPa or less, especially 50MPa or less, further , may be 45MPa or less, 40MPa or less, 35MPa or less, or 30MPa or less, or may be 1MPa or more, 3MPa or more, 5MPa or more, 7MPa or more, 10MPa or more, 12MPa or more, or 15MPa or more.

The kinematic viscosity at 40°C of the lubricating oil composition according to one aspect of the present invention is preferably 500 mm ² /s or less, 400 mm ² /s or less, or 300 mm ² from the viewpoint of producing a lubricating oil composition with good handleability. /s or less, 250mm ² /s or less, 200mm ² /s or less, 150mm 2 /s or less, 100mm ² /s or less, 90mm ^{2 /} s or less, 80mm ² /s or less, 70mm ² /s or less, 60mm ² /s Below, below 50mm ² /s, below 40mm ² /s, below 30mm ² /s, below 20mm ² /s, below 15mm ² /s, below 12mm ² /s, below 10mm ² /s or below 9.0mm ² /s , In addition, from the point of view of maintaining a strong oil film and reducing evaporation loss, it is preferably set at 2.0mm ² /s or more, 2.5mm ² /s or more, 3.0mm ² /s or more, 3.5mm ² /s or more, 4.0 mm ² /s or more, 4.5 mm ² /s or more, 5.0 mm ² /s or more, 5.5 mm ² /s or more, 6.0 mm ² /s or more, or 6.5 mm ² /s or more.

In addition, the lubricating oil composition of one aspect of the present invention can adjust the types of components (A) and components (B) by adjusting the types of components (A) and components (B) or by adjusting the types of components (A) and components (B). ) ratio, and adjust the phase change pressure to the above range. The specific adjustment method is described later.

Moreover, the lubricating oil composition of one aspect of this invention may contain the additive for lubricating oil other than component (B) within the range which does not impair the effect of this invention. In the lubricating oil composition of one aspect of the present invention, from the viewpoint of making a lubricating oil composition that is easy to form a strong oil film in the early stage of the pressure rise process and improves lubricity, component (A) and component ( The total content of B) is based on the total amount (100% by mass) of the lubricating oil composition, preferably 70-100% by mass, more preferably 75-100% by mass, more preferably 80-100% by mass, more preferably 85-100% by mass, more preferably 90-100% by mass, more preferably 95-100% by mass, especially preferably 98-100% by mass. Hereinafter, details of each component contained in the lubricating oil composition of one aspect of the present invention will be described.

＜Component (A): Base Oil＞ The base oil (A) used in one aspect of the present invention can be, for example, at least one selected from mineral oils and synthetic oils. Mineral oil can be, for example, atmospheric residual oil obtained by atmospheric distillation of crude oil such as paraffinic crude oil, intermediate base crude oil, and naphthene crude oil; distillate oil; and purified oil obtained by subjecting the distillate oil to one or more purification treatments such as solvent deasphalting, solvent extraction, hydrogenolysis, solvent dewaxing, catalytic dewaxing, and hydrogenation purification, etc.

Synthetic oils can be, for example: polyα-olefins such as α-olefin monomers or α-olefin copolymers (such as ethylene-α-olefin copolymers and other α-olefin copolymers with 8 to 14 carbon atoms); isoparaffin (isoparaffin) ); polyalkylene glycols; ester oils such as polyol esters, dibasic acid esters, and phosphate esters; ether oils such as polyphenyl ethers; alkylbenzenes; alkylnaphthalenes; Synthetic oil (GTL) obtained by producing wax (GTL wax (Gas To Liquids WAX)) from natural gas by Fischer-Tropsch process and isomerizing it, etc.

Among them, the base oil (A) used in one aspect of the present invention preferably includes paraffinic mineral oil (A1) from the viewpoint of preparing a lubricating oil composition having a phase transition pressure within the above-mentioned range. From the above point of view, the content ratio of the paraffinic mineral oil (A1) in the base oil (A) used in one aspect of the present invention is preferably 60 to 100% by mass based on 100% by mass of the total amount of the base oil (A). And more preferably, it is 70-100 mass %, More preferably, it is 80-100 mass %, More preferably, it is 90-100 mass %, Especially preferably, it is 95-100 mass %.

The dynamic viscosity of the base oil (A) used in one aspect of the present invention at 40°C is preferably 4.0 mm ² /s or higher, more preferably 4.5 mm ² /s or higher, more preferably 5.0 mm ² /s or higher, More preferably 5.5mm ² /s or more, more preferably 6.0mm ² /s or more, especially 6.5mm ² /s or more; more preferably 100mm ² /s or less, more preferably 80mm ² /s or less , preferably less than 60mm ² /s, more preferably less than 50mm ² /s, more preferably less than 40mm ² /s, more preferably less than 30mm ² /s, especially less than 20mm ² /s, or further Set to 17 mm ² /s or less, 15 mm ² /s or less, 12 mm ² /s or less, or 10 mm ² /s or less.

In addition, the viscosity index of the base oil (A) used in one aspect of the present invention is preferably 10 or more, more preferably 20 or more, more preferably 30 or more, more preferably 40 or more, and more preferably 50 or more, especially It is preferably 60 or more; in addition, it can also be set to 200 or less, 170 or less, 150 or less, 120 or less, 100 or less, 95 or less, 90 or less, or 85 or less. In addition, in one aspect of the present invention, when a mixed oil composed of two or more base oils is used as the base oil (A), the kinematic viscosity and viscosity index of the mixed oil are preferably in the above-mentioned ranges. In addition, the weighted average of the dynamic viscosity or viscosity index calculated from the dynamic viscosity or viscosity index of each base oil constituting the mixed oil and its content is preferably within the above range.

In the lubricating oil composition according to one aspect of the present invention, the content of component (A) may be greater than 0 mass %, 0.1 mass % or more, or 0.5 mass % or more based on the total amount (100 mass %) of the lubricating oil composition , 1.0% by mass or more, 3.0% by mass or more, 5.0% by mass or more, 10.0% by mass or more, 15.0% by mass or more, 20.0% by mass or more, 25.0% by mass or more, 30.0% by mass or more, 35.0% by mass or more, 40.0% by mass or more , 45.0 mass % or more, 50.0 mass % or more, 55.0 mass % or more, 60.0 mass % or more, 65.0 mass % or more, 70.0 mass % or more, 75.0 mass % or more, 80.0 mass % or more, 85.0 mass % or more, or 90.0 mass % or more ; In addition, it can also be set to 99.0 mass % or less, 98.5 mass % or less, 98.0 mass % or less, 97.5 mass % or less, 96.0 mass % or less, 95.0 mass % or less, 90.0 mass % or less, 85.0 mass % or less, 80.0 mass % Less than, 75.0 mass % or less, 70.0 mass % or less, 65.0 mass % or less, 60.0 mass % or less, 55.0 mass % or less, 50.0 mass % or less, 45.0 mass % or less, 40.0 mass % or less, 35.0 mass % or less, 30.0 mass % Less than, 25.0 mass % or less, 20.0 mass % or less, 15.0 mass % or less, 10.0 mass % or less, 9.0 mass % or less, 8.0 mass % or less, 7.0 mass % or less, or 6.0 mass % or less.

In addition, in the lubricating oil composition according to one aspect of the present invention, the content of component (A) is preferably adjusted so that the phase transition pressure falls within the above-mentioned range according to the type of component (B). For example, when component (B) is a carboxylic acid ester or carboxylic acid with a melting point of less than 30°C, the content of component (A) is preferably less than 40.0% by mass based on the total amount (100% by mass) of the aforementioned lubricating oil composition, And preferably less than 35.0 mass%, more preferably less than 30.0 mass%, more preferably less than 25.0 mass%, more preferably less than 20.0 mass%, more preferably less than 15.0 mass%, especially preferably less than 10.0 mass%, And it can be further set to 9.0 mass % or less, 8.0 mass % or less, 7.0 mass % or less, or 6.0 mass % or less; in addition, it can also be set to be greater than 0 mass %, 0.1 mass % or more, 0.5 mass % or more, and 1.0 mass % or more , 1.5% by mass or more, 2.0% by mass or more, 2.5% by mass or more, or 3.0% by mass or more.

When component (B) contains a carboxylic acid ester or carboxylic acid having a melting point of 30°C or higher, the content of component (A) is preferably less than 80.0% by mass, more preferably 78.0% by mass, based on the total amount (100% by mass) of the aforementioned lubricating oil composition. mass % or less, more preferably less than 75.0 mass %, more preferably less than 73.0 mass %, more preferably less than 70.0 mass %, more preferably less than 68.0 mass %, especially less than 65.0 mass %; in addition, it can be set as More than 0% by mass, 0.1% by mass or more, 0.5% by mass or more, 1.0% by mass or more, 3.0% by mass or more, 5.0% by mass or more, 10.0% by mass or more, 15.0% by mass or more, 20.0% by mass or more, 25.0% by mass or more, 30.0% by mass or more, 35.0% by mass or more, 40.0% by mass or more, 45.0% by mass or more, or 50.0% by mass or more.

When component (B) contains alcohol or ether with a melting point of less than 30°C, the content of component (A) is preferably less than 40.0% by mass, more preferably 35.0% by mass or less, based on the total amount (100% by mass) of the aforementioned lubricating oil composition , preferably less than 30.0 mass%, more preferably less than 25.0 mass%, more preferably less than 20.0 mass%, more preferably less than 15.0 mass%, especially preferably less than 10.0 mass%, and can be further set to 9.0 mass% Less than, 8.0 mass % or less, 7.0 mass % or less, or 6.0 mass % or less; In addition, it can be set to more than 0 mass %, 0.1 mass % or more, 0.5 mass % or more, 1.0 mass % or more, 1.5 mass % or more, and 2.0 mass % % or more, 2.5 mass % or more, or 3.0 mass % or more.

When component (B) contains an alcohol or ether with a melting point of 30°C or more and less than 50°C, the content of component (A) is preferably 95.0% by mass or less based on the total amount (100% by mass) of the aforementioned lubricating oil composition, and less than It is preferably less than 92.0 mass%, more preferably less than 90.0 mass%, more preferably less than 87.0 mass%, more preferably less than 85.0 mass%, especially preferably less than 82.0 mass%; in addition, it can also be set to be greater than 0 mass% , 0.1 mass % or more, 0.5 mass % or more, 1.0 mass % or more, 3.0 mass % or more, 5.0 mass % or more, 10.0 mass % or more, 15.0 mass % or more, 20.0 mass % or more, 25.0 mass % or more, 30.0 mass % or more , 35.0% by mass or more, 40.0% by mass or more, 45.0% by mass or more, 50.0% by mass or more, 55.0% by mass or more, or 60.0% by mass or more.

When component (B) contains alcohol or ether with a melting point of 50°C or higher, the content of component (A) is preferably 99.0% by mass or less, more preferably 98.5% by mass, based on the total amount (100% by mass) of the aforementioned lubricating oil composition Below, preferably below 98.0% by mass, more preferably below 97.5% by mass, more preferably below 97.0% by mass, and especially below 96.5% by mass; 70.0% by mass or more, 75.0% by mass or more, 80.0% by mass or more, 85.0% by mass or more, or 90.0% by mass or more.

<Component (B): Compound> The lubricating oil composition of one aspect of the present invention contains a compound (B) selected from carboxylic acid esters, carboxylic acids, alcohols, and ethers. From the point of view of making a lubricating oil composition whose phase change pressure is within the above range, the component (B) used in one aspect of the present invention should belong to: it is liquid under normal pressure (0.1MPa pressure) but has the above-mentioned The "phase change compound" of the phase change pressure calculated by operating (i)~(iv).

From the viewpoint of producing a lubricating oil composition having a phase transition pressure within the above range, the content ratio of the phase transition compound in the component (B) used in one aspect of the present invention is preferably 100% by mass relative to the total amount of the component (B). 60-100% by mass, more preferably 70-100% by mass, more preferably 80-100% by mass, more preferably 90-100% by mass, particularly preferably 95-100% by mass.

From the viewpoint of producing a lubricating oil composition having a phase transition pressure within the above range, the aforementioned carboxylate used as component (B) in one aspect of the present invention is preferably a saturated or unsaturated chain carboxylate, And saturated chain carboxylate is more preferred. From the viewpoint of producing a lubricating oil composition with a phase transition pressure within the above range, the aforementioned carboxylic acid used as component (B) in one aspect of the present invention is preferably a saturated or unsaturated chain carboxylic acid, and saturated The chain carboxylic acid is more preferable. From the viewpoint of producing a lubricating oil composition with a phase transition pressure within the above range, the aforementioned alcohol used as component (B) in one aspect of the present invention is preferably a saturated or unsaturated chain alcohol, and a saturated chain Alcohol is better. From the viewpoint of producing a lubricating oil composition with a phase transition pressure within the above range, the aforementioned ether used as component (B) in one aspect of the present invention is preferably a saturated or unsaturated chain ether, and a saturated chain Ether is better.

In addition, from the viewpoint of producing a lubricating oil composition with a phase change pressure in the above range, the component (B) used in one aspect of the present invention preferably contains a compound having an alkyl group having 10 to 40 carbon atoms. That is, the component (B) used in one aspect of the present invention preferably includes a compound represented by any one of the following general formulas (b-1) to (b-4). [chemical formula 2]

In the aforementioned formulas (b-1) to (b-3), R ¹ , R ² and R ³ are each independently an alkyl group having 10 to 40 carbon atoms. In addition, in the aforementioned formulas (b-1) and (b-4), R ^a , R ^b and R ^c are each independently an alkyl group having 1 to 30 carbon atoms. In addition, the total carbon number of R ^b and R ^c in the aforementioned formula (b-4) is 10 or more.

The aforementioned alkyl groups that can be selected as R ¹ , R ² , and R ³ may be straight-chain or branched-chain, but from the viewpoint of producing a lubricating oil composition with a phase transition pressure within the above-mentioned range, It is preferably a straight-chain alkyl group. The number of carbon atoms in the aforementioned alkyl groups that can be selected as R ¹ , R ² and R ³ is preferably 10 or more, more preferably 11 or more, and more preferably It should be above 12, more preferably above 14, especially above 16; in addition, it should be below 40, more preferably below 35, more preferably below 30, more preferably below 25, especially below 20 .

As for specific R ¹ , R ² and R ³ , for example, decyl, undecyl, dodecyl (lauryl), tridecyl, tetradecyl (myristyl), decanyl Pentadecyl, hexadecyl, heptadecyl, octadecyl (stearyl), eicosyl and tetracosyl, etc. Among these, R ¹ , R ² and R ³ are preferably each independently undecyl, dodecyl (lauryl), Tridecyl, Myristyl (Myristyl), Hexadecyl, Heptadecyl and Octadecyl (Stearyl).

In addition, the above-mentioned alkyl groups that can be selected as R ^a , R ^b and R ^c may be linear or branched, but from the viewpoint of producing a lubricating oil composition with a phase transition pressure within the above range See, it is preferably a straight chain alkyl group. From the point of view of producing a lubricating oil composition with a phase change pressure in the above range, the carbon number of the aforementioned alkyl groups that can be selected as R ^a , R ^b and R ^c is 1 to 30, and preferably 1 to 25 , more preferably 1~20.

In addition, the carbon number of the aforementioned alkyl group that can be selected as ^Ra in the aforementioned formula (b-1) is preferably 1 to 10 from the viewpoint of producing a lubricating oil composition with a phase transition pressure within the aforementioned range, and is relatively It is preferably 1~6, more preferably 1~4, more preferably 1~2, especially 1.

In addition, although the total carbon number of R ^b and R ^c in the aforementioned formula (b-4) is 10 or more, it is preferably 11 or more, more preferably 12 or more, more preferably 14 or more, and more preferably 16 or more. In addition, it should be less than 40, more preferably less than 35, more preferably less than 30, more preferably less than 25, especially less than 20.

Concrete R ^a , R ^b and R ^c can be, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, secondary butyl, tertiary butyl, isobutyl, pentyl, hexyl, Heptyl, octyl, 2-ethylhexyl, nonyl and decyl, etc. In addition, from the point of view of producing a lubricating oil composition with a phase change pressure in the above range, R ^a in the aforementioned formula (b-1) is preferably methyl, ethyl, n-propyl, n-butyl, n-pentyl Base, n-hexyl, n-heptyl or n-octyl, and preferably methyl, ethyl, n-propyl, n-butyl, n-pentyl or n-hexyl, more preferably methyl, ethyl, n-propyl Or n-butyl, more preferably methyl or ethyl, especially methyl.

In the lubricating oil composition according to one aspect of the present invention, the content ratio of the compound represented by any one of the aforementioned general formulas (b-1) to (b-4) in component (B) is relative to the content of the lubricating oil composition The total amount (100% by mass) of component (B) is preferably 60 to 100% by mass, more preferably 70 to 100% by mass, more preferably 80 to 100% by mass, more preferably 90 to 100% by mass, especially preferably 95~100% by mass.

The melting point of the component (B) used in the lubricating oil composition of one aspect of the present invention is preferably 5°C or higher, more preferably 10°C or higher, and more preferably 10°C or higher, from the viewpoint of producing a lubricating oil composition having a phase transition pressure in the above range. It is preferably above 15°C; in addition, it is preferably below 90°C, more preferably below 80°C, more preferably below 70°C, and more preferably below 65°C.

In addition, in this specification, a melting point is the value measured using the differential scanning calorimeter (DSC), Specifically, it measures by the following method. [Measuring method of melting point using differential scanning calorimeter] After keeping the sample at -10°C for 5 minutes under a nitrogen atmosphere, the temperature was raised to 190°C at 10°C/min and kept at 190°C for 5 minutes. Next, the temperature was lowered to -10°C at 5°C/min and held at -10°C for 5 minutes. Thereafter, the temperature was raised to 190° C. at 10° C./minute, and a sharp peak was observed from the obtained melting endothermic curve, which was defined as the melting point (Tm).

In the lubricating oil composition according to one aspect of the present invention, the content of the component (B) may be 1.0 mass % or more, 1.5 mass % or more, or 2.0 mass % or more based on the total amount (100 mass %) of the lubricating oil composition , 2.5 mass % or more, 3.0 mass % or more, 4.0 mass % or more, 5.0 mass % or more, 10.0 mass % or more, 15.0 mass % or more, 20.0 mass % or more, 25.0 mass % or more, 30.0 mass % or more, 35.0 mass % or more , 40.0 mass % or more, 45.0 mass % or more, 50.0 mass % or more, 55.0 mass % or more, 60.0 mass % or more, 65.0 mass % or more, 70.0 mass % or more, 75.0 mass % or more, 80.0 mass % or more, 85.0 mass % or more or more than 90.0% by mass, or less than 100% by mass, less than 99.9% by mass, less than 99.5% by mass, less than 99.0% by mass, less than 98.5% by mass, less than 98.0% by mass, less than 97.0% by mass, or less than 96.0% by mass Less than, 95.0 mass % or less, 90.0 mass % or less, 85.0 mass % or less, 80.0 mass % or less, 75.0 mass % or less, 70.0 mass % or less, 65.0 mass % or less, 60.0 mass % or less, 55.0 mass % or less, 50.0 mass % Less than, 45.0 mass % or less, 40.0 mass % or less, 35.0 mass % or less, 30.0 mass % or less, 25.0 mass % or less, 20.0 mass % or less, 15.0 mass % or less, or 10.0 mass % or less.

In addition, in the lubricating oil composition of one aspect of the present invention, the content of the component (B) is preferably adjusted so that the phase transition pressure falls within the above-mentioned range according to the type of the component (B). For example, when component (B) contains a carboxylate or carboxylic acid with a melting point of less than 30°C, the content of component (B) is preferably greater than 60.0% by mass based on the total amount (100% by mass) of the aforementioned lubricating oil composition, and More preferably 65.0 mass % or more, more preferably 70.0 mass % or more, more preferably 75.0 mass % or more, more preferably 80.0 mass % or more, more preferably 85.0 mass % or more, especially preferably 90.0 mass % or more, can be It is further set to be 92.0 mass % or more, 95.0 mass % or more, or 97.0 mass % or more; in addition, it may be less than 100 mass %, 99.9 mass % or less, 99.5 mass % or less, 99.0 mass % or less, 98.5 mass % or less, 98.0 mass % or less Mass % or less, 97.5 mass % or less, or 97.0 mass % or less. In addition, the melting point of the above-mentioned carboxylate or carboxylic acid having a melting point of less than 30°C may be 27°C or lower, 25°C or lower, or 23°C or lower, and may be 5°C or higher, 10°C or higher, 12°C or higher, or 15°C or higher. .

When component (B) contains a carboxylic acid ester or carboxylic acid having a melting point of 30°C or higher, the content of component (B) is preferably 20.0% by mass or more based on the total amount (100% by mass) of the aforementioned lubricating oil composition, and preferably It is more than 22.0 mass%, preferably more than 25.0 mass%, more preferably more than 27.0 mass%, more preferably more than 30.0 mass%, more preferably more than 32.0 mass%, especially preferably more than 35.0 mass%, and can be further 37.0% by mass or more than 40.0% by mass; In addition, less than 100% by mass, 99.9% by mass or less, 99.5% by mass or less, 99.0% by mass or less, 97.0% by mass or less, 95.0% by mass or less, 90.0% by mass Less than, 85.0 mass % or less, 80.0 mass % or less, 75.0 mass % or less, 70.0 mass % or less, 65.0 mass % or less, 60.0 mass % or less, 55.0 mass % or less, or 50.0 mass % or less. In addition, the above-mentioned carboxylate or carboxylic acid having a melting point of 30°C or higher may have a melting point of 32°C or higher, 34°C or higher, or 36°C or higher, and may also be 90°C or lower, 80°C or lower, 70°C or lower, or 65°C or lower. , below 60°C, below 55°C, below 50°C, below 47°C, below 45°C or below 43°C.

When component (B) contains alcohol or ether with a melting point of less than 30°C, the content of component (B) is preferably greater than 60.0% by mass, more preferably 65.0% by mass, based on the total amount (100% by mass) of the aforementioned lubricating oil composition % or more, preferably more than 70.0 mass%, more preferably more than 75.0 mass%, more preferably more than 80.0 mass%, more preferably more than 85.0 mass%, especially preferably more than 90.0 mass%, and can be further set to 92.0 Mass % or more, 95.0 mass % or more, or 97.0 mass % or more; In addition, less than 100 mass %, 99.9 mass % or less, 99.5 mass % or less, 99.0 mass % or less, 98.5 mass % or less, 98.0 mass % or less, 97.5 mass % or less or 97.0 mass % or less. In addition, the melting point of the above-mentioned alcohols or ethers with a melting point of less than 30°C may be 28°C or lower, 26°C or lower, or 25°C or lower. In addition, the melting point may be 5°C or higher, 10°C or higher, 12°C or higher, 15°C or higher, or 17°C above or above 20°C.

When component (B) contains an alcohol or ether with a melting point of 30°C or more and less than 50°C, the content of component (B) is preferably 5.0% by mass or more based on the total amount (100% by mass) of the aforementioned lubricating oil composition, and More preferably 8.0% by mass or more, more preferably 10.0% by mass or more, more preferably 13.0% by mass or more, more preferably 15.0% by mass or more, especially preferably 18.0% by mass or more, and preferably less than 100% by mass, 99.9% by mass Mass % or less, 99.5 mass % or less, 99.0 mass % or less, 97.0 mass % or less, 95.0 mass % or less, 90.0 mass % or less, 85.0 mass % or less, 80.0 mass % or less, 75.0 mass % or less, 70.0 mass % or less, 65.0 mass % or less Mass % or less, 60.0 mass % or less, 55.0 mass % or less, 50.0 mass % or less, 45.0 mass % or less, 40.0 mass % or less, 35.0 mass % or less, 30.0 mass % or less, or 25.0 mass % or less. In addition, the melting point of the above-mentioned alcohol or ether having a melting point of 30°C or higher and lower than 50°C may be 32°C or higher, 34°C or higher, or 36°C or higher, and may be 47°C or lower, 45°C or lower, 42°C or lower, or 40°C the following.

When component (B) contains alcohol or ether with a melting point of 50°C or higher, the content of component (B) is preferably at least 1.0% by mass, more preferably 1.5% by mass, based on the total amount (100% by mass) of the aforementioned lubricating oil composition. More than 2.0 mass %, more preferably 2.2 mass % or more, more preferably 2.5 mass % or more, particularly preferably 2.7 mass % or more, in addition, it can also be set to 40.0 mass % or less, 35.0 mass % % or less, 30.0 mass % or less, 25.0 mass % or less, 20.0 mass % or less, 15.0 mass % or less, 10.0 mass % or less, 8.0 mass % or less, 6.0 mass % or less, 5.0 mass % or less, or 4.0 mass % or less. In addition, the melting point of the above-mentioned alcohol or ether having a melting point of 50°C or higher may be 52°C or higher, 54°C or higher, 56°C or higher, or 58°C or higher, and may be 90°C or lower, 80°C or lower, 70°C or lower, 67°C Below 65°C, below 62°C or below 60°C.

＜Additives for other lubricating oils＞ The lubricating oil composition of one aspect of the present invention may further contain other lubricating oil additives other than the above as needed within the range not impairing the effect of the present invention. Such other lubricating oil additives can be appropriately set depending on the use of the lubricating oil composition, such as viscosity index improvers, antioxidants, extreme pressure agents, metal-based detergents, ashless dispersants, metal deactivators, anti-oxidants, etc. Corrosive agent, antirust agent, oily enhancer and defoamer, etc.

In the lubricating oil composition according to one aspect of the present invention, the content of other lubricating oil additives other than component (B) can be set to less than 90 mass parts with respect to 100 mass parts of the total amount of component (B) contained in the lubricating oil composition. Parts, less than 80 parts by mass, less than 70 parts by mass, less than 60 parts by mass, less than 50 parts by mass, less than 40 parts by mass, less than 30 parts by mass, less than 20 parts by mass, less than 10 parts by mass, less than 5.0 parts by mass, less than 2.0 parts by mass parts, less than 1.0 parts by mass, less than 0.1 parts by mass, less than 0.01 parts by mass or less than 0.001 parts by mass.

＜Pour point depressants＞ The lubricating oil composition of one aspect of the present invention may contain a pour point depressant from the viewpoint of being a lubricating oil composition with good low-temperature fluidity. In addition, the lubricating oil composition according to one aspect of the present invention can maintain good lubricity even if it contains a pour point depressant.

The pour point depressant used in one aspect of the present invention can be exemplified by ethylene-vinyl acetate copolymer, condensate of chlorinated paraffin and naphthalene, condensate of chlorinated paraffin and phenol, polymethacrylate and polyalkylene Styrene etc. These pour point depressants may be used alone or in combination of two or more. Among them, the pour point depressant preferably contains one or more selected from ethylene-vinyl acetate copolymers and polymethacrylates. The mass average molecular weight (Mw) of the pour point depressant can be set to 5,000 or more, 7,000 or more, 10,000 or more, 15,000 or more, 20,000 or more, 25,000 or more, 30,000 or more, 35,000 or more, 40,000 or more, 45,000 or more, 50,000 or more, 55,000 or more 60,000 or more, but also 150,000 or less, 120,000 or less, 100,000 or less, 90,000 or less, or 80,000 or less. In addition, the molecular weight distribution (Mw/Mn) of the pour point depressant can be set to 10 or less, 8.0 or less, 7.0 or less, 6.0 or less, 5.0 or less, 4.0 or less, 3.5 or less, 3.0 or less, or 2.6 or less. Above 1.01, above 1.05 or above 1.1.

In the lubricating oil composition according to one aspect of the present invention, the content of the pour point depressant is based on the total amount of the lubricating oil composition ( 100% by mass) should be 0.001-7.0% by mass, more preferably 0.01-5.0% by mass, more preferably 0.1-3.0% by mass, and more preferably 0.3-2.0% by mass. In addition, it can also be set to be less than 1.7% by mass, less than 1.5% by mass, less than 1.2% by mass, less than 1.0% by mass, less than 0.5% by mass, less than 0.1% by mass, less than 0.01% by mass, less than 0.001% by mass, or less than 0.0001% by mass.

＜Viscosity Index Improver＞ The viscosity index improver used in one aspect of the present invention can be, for example, non-dispersed polymethacrylate, dispersed polymethacrylate, olefin-based copolymers (such as ethylene-propylene copolymers, etc.), dispersed-type olefin-based Polymers such as copolymers and styrene-based copolymers (such as styrene-diene copolymers, styrene-isoprene copolymers, etc.). These viscosity index improvers may be used alone or in combination of two or more. In addition, the weight average molecular weight (Mw) of the viscosity index improver used in one aspect of the present invention can be set to 5,000 or more, 7,000 or more, 10,000 or more, 15,000 or more, or 20,000 or more, and also can be set to 1,000,000 or less, 700,000 or less , less than 500,000, less than 300,000, less than 200,000, less than 100,000, or less than 50,000. In the lubricating oil composition according to one aspect of the present invention, the content of the viscosity index improver can be set to be less than 7.0 mass%, less than 5.0 mass%, or less than 2.0 mass% based on the total amount (100 mass%) of the lubricating oil composition %, less than 1.0 mass%, less than 0.5 mass%, less than 0.1 mass%, less than 0.01 mass%, less than 0.001 mass%, or less than 0.0001 mass%.

＜Antioxidant＞ The antioxidant used in one aspect of the present invention can be, for example, amine antioxidants such as alkylated diphenylamine, phenylnaphthylamine, and alkylated phenylnaphthylamine; and, 2,6-di-tertiary Butylphenol, 4,4'-methylene bis(2,6-di-tertiary butylphenol), isooctyl-3-(3,5-di-tertiary butyl-4-hydroxyphenyl ) propionate, n-octadecyl-3-(3,5-di-tertiary butyl-4-hydroxyphenyl) propionate and other phenolic antioxidants. These antioxidants may be used alone or in combination of two or more. In the lubricating oil composition according to one aspect of the present invention, it is preferable to use an amine-based antioxidant and a phenolic antioxidant as an antioxidant in combination. In the lubricating oil composition of one aspect of the present invention, the content of the antioxidant can be set to be less than 7.0 mass%, less than 5.0 mass%, less than 2.0 mass%, less than 1.0% by mass, less than 0.5% by mass, less than 0.1% by mass, less than 0.01% by mass, less than 0.001% by mass, or less than 0.0001% by mass.

＜Extreme pressure agent＞ The extreme pressure agent (anti-wear agent) used in one aspect of the present invention can be, for example: sulfurized olefin, polysulfide, sulfurized ester, thiazole, thiadiazole, zinc dithiophosphate, molybdenum dithiophosphate, disulfide Sulfur-based extreme pressure agents such as molybdenum carbamate and sulfur powder; phosphate esters (tricresyl phosphate, trioleyl phosphate, etc.), acid phosphate esters (monooleyl acid phosphate, dioleyl acid phosphate, etc.), acid phosphoric acid esters Phosphorus-based extreme pressure agents such as ester amine salt (oleylamine salt of monooleyl acid phosphate, etc.), phosphite (dioleyl acid phosphate, tridecyl phosphate, ginseng nonylphenyl sulfur, etc.); and , Grease (butter, lard oil, soybean oil, rapeseed oil, rice bran oil, coconut oil, palm oil, etc.) and so on.

The lubricating oil composition according to one aspect of the present invention will solidify at an early stage when the pressure is below 70MPa during the pressure rise process, and form a strong oil film, which can exhibit good lubricity at an early stage, so there is no need to contain sulfur It is an extreme pressure agent and a phosphorus extreme pressure agent. Therefore, in the lubricating oil composition of an aspect of the present invention, the content of the extreme pressure agent can be set to be less than 50 mass parts, less than 40 mass parts, less than 100 mass parts of the total amount of component (B) contained in the lubricating oil composition. 30 parts by mass, less than 20 parts by mass, less than 15 parts by mass, less than 10 parts by mass, less than 5.0 parts by mass, less than 2.0 parts by mass, less than 1.0 parts by mass, less than 0.1 parts by mass, less than 0.01 parts by mass, or less than 0.001 parts by mass. In addition, in the lubricating oil composition of an aspect of the present invention, the content of the extreme pressure agent can be set to be less than 7.0 mass%, less than 5.0 mass%, and less than 2.0 mass% based on the total amount (100 mass%) of the lubricating oil composition. % by mass, less than 1.0% by mass, less than 0.5% by mass, less than 0.1% by mass, less than 0.01% by mass, less than 0.001% by mass, or less than 0.0001% by mass.

In the lubricating oil composition according to one aspect of the present invention, the content of the sulfur-based extreme pressure agent can be set to be less than 50 parts by mass or less than 40 parts by mass relative to 100 parts by mass of the total amount of component (B) contained in the lubricating oil composition , less than 30 parts by mass, less than 20 parts by mass, less than 15 parts by mass, less than 10 parts by mass, less than 5.0 parts by mass, less than 2.0 parts by mass, less than 1.0 parts by mass, less than 0.1 parts by mass, less than 0.01 parts by mass, or less than 0.001 parts by mass . In addition, in the lubricating oil composition of an aspect of the present invention, the content of the sulfur-based extreme pressure agent can be set to be less than 7.0 mass%, less than 5.0 mass%, less than 2.0% by mass, less than 1.0% by mass, less than 0.5% by mass, less than 0.1% by mass, less than 0.01% by mass, less than 0.001% by mass, or less than 0.0001% by mass.

In the lubricating oil composition of one aspect of the present invention, the content of the phosphorus-based extreme pressure agent can be set to less than 50 mass parts, less than 40 mass parts, Less than 30 parts by mass, less than 20 parts by mass, less than 15 parts by mass, less than 10 parts by mass, less than 5.0 parts by mass, less than 2.0 parts by mass, less than 1.0 parts by mass, less than 0.1 parts by mass, less than 0.01 parts by mass, or less than 0.001 parts by mass. In addition, in the lubricating oil composition of an aspect of the present invention, the content of the phosphorus-based extreme pressure agent can be set to be less than 7.0 mass%, less than 5.0 mass%, less than 2.0% by mass, less than 1.0% by mass, less than 0.5% by mass, less than 0.1% by mass, less than 0.01% by mass, less than 0.001% by mass, or less than 0.0001% by mass.

＜Metal-based cleaners＞ Metal-based detergents used in one aspect of the present invention include metal salts such as metal sulfonate, metal salicylate, and metal phenate. In addition, the metal atom constituting the metal salt is preferably a metal atom selected from alkali metals and alkaline earth metals, preferably sodium, calcium, magnesium or barium, and more preferably calcium. These metal-based detergents may be used alone or in combination of two or more.

The base value of the metal-based detergent should be 0~600mgKOH/g. However, in the lubricating oil composition according to one aspect of the present invention, the metal-based detergent is preferably an overbased (overbased) metal-based detergent with a base value of 100 mgKOH/g or more. Although the base value of the overbased metal-based detergent is above 100mgKOH/g, it is preferably 150~500mgKOH/g, more preferably 200~450mgKOH/g. In addition, in this specification, "base number" refers to the base number obtained by the perchloric acid method measured in accordance with 7. of JIS K2501:2003 "Petroleum products and lubricating oil-neutralization value test method".

In the lubricating oil composition according to one aspect of the present invention, the content of the metal-based detergent can be set to be less than 10.0 mass%, less than 7.0 mass%, or less than 5.0 mass% based on the total amount (100 mass%) of the lubricating oil composition %, less than 2.0 mass%, less than 1.0 mass%, less than 0.5 mass%, less than 0.1 mass%, less than 0.01 mass%, less than 0.001 mass%, or less than 0.0001 mass%.

＜Ashless Dispersant＞ The ashless dispersant used in one aspect of the present invention can be, for example, non-boron-containing succinimides such as non-boron-containing alkenyl succinimide, boron-containing succinimide such as boron-containing alkenyl succinimide, etc. Amides, benzylamines, boron-containing benzylamines, succinates, one- or two-basic carboxamides represented by fatty acids or succinic acid, etc. These ashless dispersants may be used alone or in combination of two or more. In the lubricating oil composition according to one aspect of the present invention, the content of the ashless dispersant can be set to less than 15.0 mass%, less than 12.0 mass%, and less than 10.0 mass% based on the total amount (100 mass%) of the lubricating oil composition %, less than 7.0 mass%, less than 5.0 mass%, less than 2.0 mass%, less than 1.0 mass%, less than 0.5 mass%, less than 0.1 mass%, less than 0.01 mass%, less than 0.001 mass%, or less than 0.0001 mass%.

＜Metal deactivator＞ The metal deactivator used in one aspect of the present invention can be, for example, benzothiazole compounds, benzotriazole-based compounds, tolyltriazole-based compounds, imidazole-based compounds, thiadiazole-based compounds, and pyrimidine-based compounds. These metal deactivators may be used alone or in combination of two or more. In the lubricating oil composition according to one aspect of the present invention, the content of the metal deactivator can be set to be less than 7.0 mass%, less than 5.0 mass%, or less than 2.0 mass% based on the total amount (100 mass%) of the lubricating oil composition , less than 1.0% by mass, less than 0.5% by mass, less than 0.1% by mass, less than 0.01% by mass, less than 0.001% by mass, or less than 0.0001% by mass.

＜Anticorrosion agent＞ The corrosion inhibitor used in one aspect of the present invention can be, for example, amine compounds, alkanolamine compounds, amide compounds, and carboxylic acid compounds. These anticorrosion agents may be used alone or in combination of two or more. In the lubricating oil composition according to one aspect of the present invention, the content of the anticorrosive agent can be set to be less than 7.0 mass%, less than 5.0 mass%, less than 2.0 mass%, less than 1.0% by mass, less than 0.5% by mass, less than 0.1% by mass, less than 0.01% by mass, less than 0.001% by mass, or less than 0.0001% by mass.

＜Rust inhibitor＞ The antirust agent used in one aspect of the present invention can be, for example, fatty acid, alkenyl succinic acid half ester, fatty acid soap, alkyl sulfonate, polyol fatty acid ester, fatty acid amine, oxidized paraffin wax and alkyl polyoxyethylene ether wait. These antirust agents may be used alone or in combination of two or more. In the lubricating oil composition according to one aspect of the present invention, the content of the antirust agent can be set to be less than 7.0 mass%, less than 5.0 mass%, less than 2.0 mass%, based on the total amount (100 mass%) of the lubricating oil composition. Less than 1.0% by mass, less than 0.5% by mass, less than 0.1% by mass, less than 0.01% by mass, less than 0.001% by mass, or less than 0.0001% by mass.

＜Oil Lifting Agent＞ The oily enhancer used in one aspect of the present invention can be, for example: polymers of polymerized fatty acids such as dimer acid and hydrogenated dimer acid; aliphatic saturated or unsaturated monoalcohols such as lauryl alcohol and oleyl alcohol; stearin aliphatic saturated or unsaturated monoamines such as amine and oleylamine; and aliphatic saturated or unsaturated monocarboxamides such as lauramide and oleylamine. These oiliness enhancers may be used alone or in combination of two or more. In the lubricating oil composition according to one aspect of the present invention, the content of the oily improving agent can be set to be less than 7.0 mass%, less than 5.0 mass%, less than 2.0 mass%, based on the total amount (100 mass%) of the lubricating oil composition. Less than 1.0% by mass, less than 0.5% by mass, less than 0.1% by mass, less than 0.01% by mass, less than 0.001% by mass, or less than 0.0001% by mass.

＜Degreaser＞ The degreasing agent used in one aspect of the present invention may, for example, be alkenyl sulfosuccinic acid or the like. These degreasing agents may be used alone or in combination of two or more. In the lubricating oil composition according to one aspect of the present invention, the content of the degreasing agent can be set to be less than 7.0 mass%, less than 5.0 mass%, less than 2.0 mass%, less than 1.0% by mass, less than 0.5% by mass, less than 0.1% by mass, less than 0.01% by mass, less than 0.001% by mass, or less than 0.0001% by mass.

＜Defoamer＞ The defoaming agent used in one aspect of the present invention can be, for example, polysiloxane oil, fluoropolysiloxane oil, and fluoroalkyl ether. These antifoamers may be used alone or in combination of two or more. In the lubricating oil composition according to one aspect of the present invention, the content of the antifoaming agent can be set to be less than 7.0 mass%, less than 5.0 mass%, less than 2.0 mass%, based on the total amount (100 mass%) of the lubricating oil composition. Less than 1.0% by mass, less than 0.5% by mass, less than 0.1% by mass, less than 0.01% by mass, less than 0.001% by mass, or less than 0.0001% by mass.

[lubricating oil] One aspect of the present invention can be: substantially composed of compound (B) selected from carboxylic acid esters, carboxylic acids, alcohols and ethers, and the phase transition pressure calculated by the above operations (i)~(iv) is 70 MPa The following lubricating oils. The component (B) constituting the lubricating oil according to one aspect of the present invention may be the same as the component (B) contained in the above-mentioned lubricating oil composition according to one aspect of the present invention, and preferred aspects are also the same as above. In addition, the lubricating oil of the one aspect of the present invention is different from the lubricating oil composition of the above-mentioned one aspect of the present invention that substantially contains the base oil (A) other than the component (B) and additives for lubricating oil.

In this specification, "consisting essentially of compound (B)" is a stipulation that excludes the form containing other components other than component (B) based on a specific purpose, rather than including other components other than component (B). Aspects of avoidable impurities are excluded. However, even considering the fact that components other than component (B) contain unavoidable impurities, it is better to reduce the components other than component (B) as much as possible.

In the lubricating oil according to one aspect of the present invention, the content of other components other than component (B) is preferably less than 1.0% by mass, more preferably less than 0.1% by mass, more preferably less than 0.01% by mass, more preferably less than 0.001% by mass, more preferably less than 0.0001% by mass, especially less than 0.00001% by mass.

[Lubricating oil composition and use of lubricating oil] The lubricating oil composition and lubricating oil according to an aspect of the present invention undergoes a phase transition at a relatively early stage in an environment accompanied by an increase in specific pressure to form a strong oil film, and has the property of exhibiting good lubricating properties, so it can be used in various applications superior.

For example, the lubricating oil composition or lubricating oil according to one aspect of the present invention can be used as a metalworking fluid in metalworking. For example, it can suppress scratching of metal materials in cold forging processing, and can suppress cracking of processed products by forming a tough oil film in deep drawing processing, and can exhibit excellent processability. Specific metal processing can include stamping processing, forging processing, extrusion processing, rolling processing, deep drawing processing, drawing processing, ironing processing, bending processing, rolling processing, cold forging processing, etc. of the above metal materials. plastic processing. In addition, metal materials processed using the lubricating oil composition or lubricating oil according to one aspect of the present invention are not particularly limited, but examples include iron alloys such as steel, stainless steel, alloy steel, and surface-treated steel, as well as aluminum alloys, copper, titanium, Titanium alloys, nickel-based alloys, niobium alloys, tantalum alloys, molybdenum alloys, tungsten alloys and other non-ferrous alloys.

When using the lubricating oil composition or lubricating oil of an aspect of the present invention and carrying out the deep drawing test according to the method described in the examples below, the maximum anti-wrinkle pressure plate load should be 100kN, more preferably 120kN or more, more preferably 140kN or more, More preferably, it is not less than 150 kN, more preferably not less than 170 kN, especially preferably not less than 200 kN.

In addition, the lubricating oil composition of an aspect of the present invention can also be used as a metal processing oil in cutting processing in addition to plastic processing, and can also be used in applications such as bearing oil, internal combustion engine oil, ATF oil, Gear oil, hydraulic starting oil, grease, etc. Example

Next, the present invention is described in more detail by examples, but the present invention is not limited by such examples. In addition, the measurement methods of various physical properties are as follows.

(1) Dynamic viscosity, viscosity index Measurement and calculation are performed in accordance with JIS K2283:2000. (2) Weight average molecular weight (Mw), number average molecular weight (Mn) The measurement was carried out under the following conditions using a gel permeation chromatography device (manufactured by Agilent Technologies, Inc., "HPLC Model 1260"), and values measured in terms of standard styrene were used. (measurement conditions) ・Tube string: Two tubes "Shodex LF404" are sequentially connected. ・Column temperature: 35°C ・Development solvent: Chloroform ・Flow rate: 0.3mL/min

(3) Phase change pressure Use the high-pressure testing machine shown in Figure 1 to perform the above operations (i)~(iv), and calculate the "phase transition pressure" at 30°C of the lubricating oil composition or lubricating oil sample oil to be measured. Specifically, in operation (i), 2 mL of a sample oil at 30° C. to be measured is filled in the cylindrical chamber 14 (chamber inner diameter: 12.0 mm) of the high pressure measurement testing machine 1 . Next, in terms of operation (ii), using a compression tensile testing machine (manufactured by Instron Corporation, product name "55RF1186 testing machine") (not shown), a load is applied in the vertical direction through the plunger 13 at a rate of 0.01mm/ The velocity of s is applied to the sample oil in the chamber 14 in the vertical direction. In addition, since the load of the plunger 13 includes the resistance caused by the plunger 13 and the sealing material of the pressure vessel, the pressure calculated from the load/sectional area is multiplied by 0.964 in consideration of the resistance, that is, from "load/sectional area × 0.964 "The calculated value is the pressure P (MPa) in the chamber 14. Then obtain a correlation diagram with the pressure P (MPa) in the aforementioned chamber as the horizontal axis and the pushing length Y (mm) of the aforementioned plunger in the vertical direction as the vertical axis. Then, as far as operation (iii) and operation (iv) are concerned, according to the above procedure, the pressure P in the chamber is calculated from the correlation diagram obtained in operation (ii) to be n (MPa) (n is an integer greater than 1). Tangent slope [ΔX/ΔY] and rate of change (%) of tangent slope [ΔX/ΔY]. On this premise, let the pressure P in the chamber when the rate of change exceeds 2% for the first time, namely n (MPa), be the aforementioned phase transition pressure. In addition, even if the pressure P in the chamber rises to 100MPa, the test oil whose change rate does not exceed 2% is judged as "no phase change" and the measurement of the phase change pressure is terminated.

Examples 1-11 and Comparative Examples 1-10 were blended with ingredients selected from the following base oils, various additives and pour point depressants according to the blending amounts shown in Tables 1 and 2 to prepare lubricating oil compositions or lubricating oil. [Base oil] ・Paraffinic mineral oil: Paraffinic mineral oil with kinematic viscosity at 40°C = 8.11 mm ² /s and viscosity index = 83.・Naphthenic mineral oil: naphthenic mineral oil with kinematic viscosity at 40°C = 9.11 mm ² /s and viscosity index = 26. [Various compounds] ・Butyl stearate: a compound in which R ¹ =C17 alkyl and R ^a =n-butyl in the aforementioned general formula (b-1), melting point=17~22°C.・Methyl stearate: a compound in which R ¹ = C17 alkyl and R ^a = methyl in the aforementioned general formula (b-1), melting point = 37~41°C.・Lauryl Alcohol: A compound in which R ³ =C12 alkyl in the aforementioned general formula (b-3), melting point=23.5°C.・Myristyl alcohol: the compound of R ³ =C14 alkyl in the aforementioned general formula (b-3), melting point=38°C.・Stearyl Alcohol: The compound in which R ³ =C18 alkyl in the aforementioned general formula (b-3), melting point=59.4~59.8°C.・Methyl oleate: a compound in which R ¹ = oleyl and R ^a = methyl in the aforementioned general formula (b-1), melting point = -19.9°C. [Pour point depressant] ・Polymethacrylate (polymethacrylate with Mw=69,000, Mn=28,000 and Mw/Mn=2.46)

For the prepared lubricating oil composition or lubricating oil, measure the phase transition pressure with the above method and carry out the following deep drawing test. These results are shown in Tables 1 and 2. Shown in Fig. 2: the pressure P in the chamber obtained through operation (i)~(iv) of the sample oil of Example 1 and the correlation diagram of the plunger pushing length Y, and the tangent to the pressure P in the chamber Plot of rate of change of slope [ΔX/ΔY]. As shown in the change rate diagram shown in Figure 2, when the pressure P in the chamber is increased by 1 MPa, the pressure in the chamber when the change rate of the tangent slope [ΔX/ΔY] exceeds 2% for the first time is "26 MPa", so that This value is "Phase Change Pressure". In addition, for the sample oils of Examples 2 to 11, the same correlation diagram and change rate diagram as in FIG. 2 were obtained, and the phase transition pressure was similarly calculated.

[deep draw test] The deep drawing test was performed using a deep drawing tester (Tokyo Hengki Testing Machinery Co., Ltd., product name "Automatic Universal Deep Drawing Tester USM-350D"). Punches (material: SKD11, R= 10. Diameter = 50mm) and mold (material: SKD11, R = 10, diameter = 52mm), at room temperature (25°C), the load of the anti-wrinkle platen has been set from 30kN, 40kN, 50kN, 60kN・・・Deep drawing test with step-by-step increase of 10kN up to 200kN. In addition, in the deep drawing test of each anti-wrinkle press plate load, for example, when the processed product breaks under the anti-wrinkle press plate load X (kN), let the previously measured load "X-10 (kN)" be "Maximum wrinkle platen load", terminated without further testing. In addition, when the processed product does not break even when the load of the anti-wrinkle plate is 200kN, set the "maximum anti-wrinkle plate load" to "200kN". The higher the maximum anti-wrinkle platen load value, the better the processability of the prepared lubricating oil composition or lubricating oil. In addition, when the maximum anti-wrinkle platen load is 100kN or more, it is judged that the lubricating oil composition or lubricating oil to be measured has excellent processability.

[Table 1]

[Table 2]

It can be seen from Table 1 that the lubricating oil compositions or lubricating oils prepared in Examples 1-11 exhibited the result that the maximum anti-wrinkle platen load was over 100kN and had excellent processability. On the other hand, the lubricating oil compositions or lubricating oils prepared in Comparative Examples 1-10 exhibited the result that the maximum anti-wrinkle platen load was less than 100 kN and the processability was not good.

1: High pressure testing machine 11: Outer cylinder of pressure vessel 12: Pressure vessel inner cylinder 13: plunger 14: chamber 15: Holding table

Fig. 1 is a schematic diagram showing an example of the structure of a high-pressure testing machine for measuring the phase transition pressure of lubricating oil compositions and lubricating oils to be measured. Fig. 2 is a graph showing the relationship between the pressure P in the chamber and the length Y of the plunger inserted after the operation (i) to (iv) of the sample oil in Example 1, and the tangent line relative to the pressure P in the chamber The rate of change of the slope [ΔX/ΔY].

(none)

Claims (15)

A lubricating oil composition comprising a base oil (A) and a compound (B) selected from carboxylic acid esters, carboxylic acids, alcohols, and ethers, and the phase transition pressure calculated by the following operations (i) to (iv) is 70 MPa or less ; ・Operation (i): Fill the aforementioned lubricating oil composition at 30°C in a columnar chamber with a fixed cross-sectional area; The composition applies a load in the vertical direction, and the pressure P (MPa) in the chamber calculated from the load/sectional area when pushed in at a speed of 0.01mm/s is the horizontal axis, and the length Y of the plunger in the vertical direction (mm) is the vertical axis, and the correlation diagram of the pressure P in the aforementioned chamber and the pushing length Y of the aforementioned plunger is obtained; ・Operation (iii): In the correlation diagram obtained in operation (ii), from the chamber From the pressure P of 0 MPa to the pressure P in the chamber becomes n (MPa) (n is an integer greater than 1), calculate the tangent slope [ΔX/ΔY] at each point of 1 MPa in sequence; ・Operation (iv): cavity When the pressure P in the chamber changes from n-1 (MPa) to n (MPa), the pressure P in the chamber when the change rate of the tangent slope [ΔX/ΔY] calculated by the following formula (1) exceeds 2% for the first time is n(MPa) is the aforementioned phase transition pressure; Formula (1): Change rate (%) of tangent slope [ΔX/ΔY]=([ΔX/ΔY] _n -[ΔX/ΔY] _n-1 )/1(MPa )×100 (In the above formula (1), [ΔX/ΔY] _n represents the tangent slope [ΔX/ΔY] at the point where the pressure P in the chamber in the aforementioned correlation diagram is n (MPa); [ΔX/ΔY] _{n -1} represents the slope of the tangent line [ΔX/ΔY] at the point where the pressure P in the chamber in the aforementioned correlation diagram is n-1 (MPa). The lubricating oil composition according to claim 1, wherein component (A) contains paraffinic mineral oil (A1). The lubricating oil composition according to claim 1 or 2, wherein the total content of component (A) and component (B) is 70 to 100% by mass based on the total amount of the aforementioned lubricating oil composition. In the lubricating oil composition according to any one of claims 1 to 3, the total content of other lubricating oil additives other than component (B) is less than 90 parts by mass relative to 100 parts by mass of the total amount of component (B). The lubricating oil composition according to any one of claims 1 to 4, wherein the content of the sulfur-based extreme pressure agent is less than 50 parts by mass relative to 100 parts by mass of the total amount of component (B). As the lubricating oil composition according to any one of claims 1 to 5, wherein the aforementioned carboxylic acid ester is a saturated or unsaturated chain carboxylic acid ester, the aforementioned carboxylic acid is a saturated or unsaturated chain carboxylic acid, and the aforementioned alcohol is Saturated or unsaturated chain alcohols, the aforementioned ethers are saturated or unsaturated chain ethers. As the lubricating oil composition according to any one of claims 1 to 5, wherein the aforementioned carboxylic acid ester is a saturated chain carboxylic acid ester, the aforementioned carboxylic acid is a saturated chain carboxylic acid, the aforementioned alcohol is a saturated chain alcohol, and the aforementioned ether is Saturated chain ether. The lubricating oil composition according to any one of claims 1 to 7, wherein component (B) comprises a compound shown in any one of the following general formulas (b-1) to (b-4); [chemical formula 1] (In the above formula, R ¹ , R ² and R ³ are each independently an alkyl group with 10 to 40 carbons; in addition, R ^a , R ^b and R ^c are each independently an alkyl group with 1 to 30 carbons; however, R The total carbon number of ^b and R ^c is 10 or more). The lubricating oil composition according to any one of claims 1 to 8, wherein the content of component (B) is 1.0% by mass or more based on the total amount of the aforementioned lubricating oil composition. The lubricating oil composition according to any one of claims 1 to 9, wherein the kinematic viscosity of the aforementioned lubricating oil composition at 40°C is 100 mm ² /s or less. The lubricating oil composition according to any one of claims 1 to 10, further comprising a pour point depressant. The lubricating oil composition according to any one of claims 1 to 11, which is used for metal processing. A lubricating oil consisting essentially of a compound (B) selected from carboxylic acid esters, carboxylic acids, alcohols, and ethers, and having a phase transition pressure calculated from the following operations (i) to (iv) below 70 MPa; ・Operation ( i): Fill the above-mentioned lubricating oil composition at 30°C in a columnar chamber with a fixed cross-sectional area; ・Operation (ii): After operation (i), the lubricating oil composition in the aforementioned chamber is vertically directed through the plunger The load is applied in the direction, and the pressure P (MPa) in the aforementioned chamber calculated from the load/sectional area when pushing in at a speed of 0.01mm/s is the horizontal axis, and the pushing length Y (mm) of the aforementioned plunger in the vertical direction is On the vertical axis, the correlation diagram of the pressure P in the chamber and the pushing length Y of the plunger is obtained; ・Operation (iii): In the correlation diagram obtained in operation (ii), the pressure P in the chamber is From 0 MPa to the pressure P in the chamber becomes n (MPa) (n is an integer greater than 1), and calculate the tangent slope [ΔX/ΔY] at each point of 1 MPa in sequence; ・Operation (iv): Pressure P in the chamber When changing from n-1 (MPa) to n (MPa), the pressure P in the chamber when the change rate of the tangent slope [ΔX/ΔY] calculated by the following formula (1) exceeds 2% for the first time is n (MPa) is the aforementioned phase transition pressure; Formula (1): Change rate (%) of tangent slope [ΔX/ΔY]=([ΔX/ΔY] _n -[ΔX/ΔY] _n-1 )/1(MPa)×100 ( In the above formula (1), [ΔX/ΔY] _n represents the tangent slope [ΔX/ΔY] at the point where the pressure P in the chamber in the aforementioned correlation diagram is n (MPa); [ΔX/ΔY] _n-1 represents the aforementioned The tangent slope [ΔX/ΔY] at the point where the pressure P in the chamber is n-1 (MPa) in the correlation diagram. As in the lubricating oil of claim 13, the content of other components other than component (B) is less than 1.0% by mass based on the total amount of the aforementioned lubricating oil. Lubricating oil as claimed in item 13 or 14, which is used for metal processing.

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