Metal processing oil composition

Abstract

To provide a metal processing oil composition in which kinematic viscosity is adjusted to be a constant value or lower, and which exhibits excellent extreme pressure property and superior performance in suppression of soot generation.SOLUTION: A metal processing oil composition comprises a base oil (A), a sulfur-based extreme pressure agent (B), and a calcium-based cleaning agent (C) having a base number of 300 mg KOH / g or more, and satisfies the following requirements (1), (2), (3), and (4). Requirement (1) is that a flash point measured by the Cleaveland open-cup method is 260°C or higher. Requirement (2) is that a sulfur content derived from the sulfur-based extreme pressure agent (B) is 0.45 mass% or more based on a total amount of the metal processing oil composition. Requirement (3) is that the calcium content is 1.0 mass% or more based on the total amount of the metal processing oil composition. Requirement (4) is that the kinematic viscosity at 40°C is 150 mm2 / s or less.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a metalworking oil composition. [Background technology]

[0002] In the field of metalworking, metalworking oil compositions are used to lubricate the machining sites of metal workpieces, and are required to have excellent extreme pressure properties in order to suppress seizure between the metal workpieces and tools. Therefore, Patent Document 1 proposes a metal working oil composition containing a sulfur-based extreme pressure agent, a rust inhibitor, and a calcium-based additive in predetermined amounts. Moreover, Patent Document 2 proposes a metal working oil composition containing a compound represented by the following general formula (1) and a sulfur-based extreme pressure agent. [ka] [In formula (1), X 1 and X 2 each independently represents an oxygen atom or a sulfur atom, R 1 ~R 4 each independently represents an alkyl group. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-119680 A [Patent Document 2] JP 2018-080303 A Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, metalworking oil compositions are required to have not only excellent extreme pressure properties but also the ability to suppress the generation of oily smoke from the viewpoint of preventing deterioration of the working environment. However, Patent Documents 1 and 2 make no consideration whatsoever about suppressing the generation of oil smoke from metalworking oil compositions. In addition, pump suction properties are sometimes required for metalworking oil compositions. Therefore, the kinetic viscosity of the metalworking oil composition needs to be adjusted to a level that ensures pump suction properties. However, if the kinetic viscosity of the metalworking oil composition is reduced, there is a problem that it becomes difficult to suppress the generation of oil smoke. Therefore, it has been difficult to obtain a metalworking oil composition that has excellent extreme pressure properties and suppression performance of the generation of oil smoke while adjusting the kinetic viscosity to a certain value or less.

[0005] An object of the present invention is to provide a metal working oil composition which has an excellent extreme pressure property and excellent performance in suppressing the generation of oily smoke while having a kinematic viscosity adjusted to a low value or less. [Means for solving the problem]

[0006] According to the present invention, the following [1] and [2] are provided. [1] A metalworking oil composition comprising a base oil (A), a sulfur-based extreme pressure agent (B), and a calcium-based detergent (C) having a base number of 300 mgKOH / g or more, and satisfying the following requirements (1), (2), (3), and (4): Requirement (1): The flash point, as determined by the Cleveland open cup test, is 260°C or higher. Requirement (2): The sulfur content derived from the sulfur-based extreme pressure agent (B) is 0.45 mass % or more based on the total amount of the metal working oil composition. Requirement (3): The calcium content is 1.0 mass % or more based on the total amount of the metal working oil composition. Requirement (4): Kinematic viscosity at 40°C is 150mm 2 / s or less. [2] A method for producing a metal working oil composition, comprising: mixing a base oil (A), a sulfur-based extreme pressure agent (B), and a calcium-based detergent (C) having a base number of 300 mgKOH / g or more so as to satisfy the following requirements (1), (2), (3), and (4): Requirement (1): The flash point, as determined by the Cleveland open cup test, is 260°C or higher. Requirement (2): The sulfur content derived from the sulfur-based extreme pressure agent (B) is 0.45 mass % or more based on the total amount of the metal working oil composition. Requirement (3): The calcium content is 1.0 mass % or more based on the total amount of the metal working oil composition. Requirement (4): Kinematic viscosity at 40°C is 150mm 2 / s or less. Effect of the Invention

[0007] According to the present invention, it is possible to provide a metal working oil composition which has excellent extreme pressure properties and excellent performance in suppressing the generation of oily smoke while having a kinematic viscosity adjusted to a low level equal to or lower than a certain value. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] The upper and lower limit values ​​of the numerical ranges described in this specification can be combined in any way. For example, when "A to B" and "C to D" are described as numerical ranges, the numerical ranges "A to D" and "C to B" are also included in the scope of the present invention. In addition, unless otherwise specified, a numerical range of "lower limit value to upper limit value" described in this specification means not less than the lower limit value and not more than the upper limit value. In this specification, the numerical values ​​in the examples are numerical values ​​that can be used as upper or lower limits.

[0009] [Embodiments of metal processing oil composition] The metal working oil composition of the present embodiment contains a base oil (A), a sulfur-based extreme pressure agent (B), and a calcium-based detergent (C) having a base number of 300 mgKOH / g or more, and satisfies the following requirements (1), (2), (3), and (4). Requirement (1): The flash point, as determined by the Cleveland open cup test, is 260°C or higher. Requirement (2): The sulfur content derived from the sulfur-based extreme pressure agent (B) is 0.45 mass % or more based on the total amount of the metal working oil composition. Requirement (3): The calcium content is 1.0 mass % or more based on the total amount of the metal working oil composition. Requirement (4): Kinematic viscosity at 40°C is 150mm 2 / s or less.

[0010] The present inventors have conducted extensive research to solve the above problems, and have found that a metal working oil composition that contains a base oil (A), a sulfur-based extreme pressure agent (B), and a calcium-based detergent (C) having a base number of 300 mgKOH / g or more and satisfies the above requirements (1), (2), (3), and (4) can solve the above problems.

[0011] In the following description, the “base oil (A)”, the “sulfur-based extreme pressure agent (B)”, and the “calcium-based detergent (C) having a base number of 300 mgKOH / g or more” will also be referred to as “component (A)”, “component (B)”, and “component (C)”, respectively.

[0012] The metal working oil composition of the present embodiment may be composed only of component (A), component (B), and component (C), or may further contain other components (hereinafter also referred to as “other components”) other than component (A), component (B), and component (C). In the lubricating oil composition of this embodiment, the total content of components (A), (B) and (C) is, based on the total amount of the lubricating oil composition, preferably 50 mass% or more, more preferably 60 mass% or more, even more preferably 70 mass% or more, still more preferably 80 mass% or more, even more preferably 85 mass% or more, still more preferably 90 mass% or more, and even more preferably 95 mass% or more.

[0013] Below, requirements (1), (2), (3), and (4), as well as requirement (5), will be explained, and then each component contained in the metal working oil composition of the present embodiment will be explained in detail, taking into account the viewpoints for adjusting requirements (1), (2), (3), and (4), as well as requirement (5).

[0014] <Requirement (1)> The metal working oil composition of the present embodiment is required to satisfy requirement (1). That is, the metal working oil composition of this embodiment is required to have a flash point of 260° C. or higher as measured by the Cleveland open cup test method. Requirement (1) is an index of the performance of a metal working oil composition in suppressing the generation of oil smoke. If a metal working oil composition does not satisfy requirement (1) (i.e., if the flash point measured by the Cleveland open cup test method is less than 260°C), the performance in suppressing the generation of oil smoke is likely to decrease. From the viewpoint of making it easier to improve the performance of suppressing the generation of oil smoke from the metal working oil composition, the flash point specified in requirement (1) is preferably 262° C. or higher, more preferably 265° C. or higher, and even more preferably 268° C. or higher. The upper limit of the flash point specified in requirement (1) is not particularly limited, but is usually 350° C. or lower. In this embodiment, the flash point of the metal working oil composition specified in the requirement (1) means a value measured by the Cleveland open cup measuring method in accordance with JIS K2265-4:2007.

[0015] <Requirement (2)> The metal working oil composition of the present embodiment must satisfy requirement (2) in addition to requirement (1). That is, the metal working oil composition of this embodiment must have a sulfur content derived from the sulfur-based extreme pressure agent (B) of 0.45 mass % or more based on the total amount of the metal working oil composition. Requirement (2) is an index of the extreme pressure properties of a metal working oil composition. If the metal working oil composition does not satisfy requirement (2) (i.e., if the sulfur content derived from the sulfur-based extreme pressure agent (B) is less than 0.45 mass% based on the total amount of the metal working oil composition), it will be difficult to ensure the extreme pressure properties. Here, from the viewpoint of making it easier to achieve excellent extreme pressure properties of the metal working oil composition, the sulfur content specified in requirement (2) is preferably 0.48 mass % or more, more preferably 0.50 mass % or more, and even more preferably 0.55 mass % or more, based on the total amount of the metal working oil composition. Moreover, from the viewpoint of making it easier to suppress the generation of oil smoke from the metal working oil composition, the content is preferably 0.75 mass % or less, more preferably 0.72 mass % or less, and even more preferably 0.70 mass % or less. The upper and lower limits of these numerical ranges can be arbitrarily combined. Specifically, the range is preferably 0.48 mass % to 0.75 mass %, more preferably 0.50 mass % to 0.72 mass %, and even more preferably 0.55 mass % to 0.70 mass %.

[0016] <Requirement (3)> The metal working oil composition of the present embodiment must satisfy requirement (3) in addition to requirements (1) and (2). That is, the metal working oil composition of this embodiment must have a calcium content of 1.0 mass % or more based on the total amount of the metal working oil composition. Like requirement (2), requirement (3) is an index of the extreme pressure properties of the metal working oil composition. If the metal working oil composition does not satisfy requirement (3) (i.e., if the calcium content is less than 1.0 mass % based on the total amount of the metal working oil composition), it becomes difficult to ensure sufficient extreme pressure properties. From the viewpoint of making it easier to improve the extreme pressure properties of the metal working oil composition, the calcium content specified in requirement (3) is preferably 1.5 mass% or more, more preferably 1.8 mass% or more, and even more preferably 2.0 mass% or more. From the viewpoint of fully exerting the effect of improving the extreme pressure properties while suppressing the calcium content, the upper limit of the calcium content specified in requirement (3) is preferably 3.5 mass% or less. In this embodiment, the calcium content of the metal working oil composition means a value measured by inductively coupled plasma atomic emission spectrometry in accordance with JPI-5S-38-03.

[0017] The calcium content of the metal working oil composition of the present embodiment is mainly derived from the calcium-based detergent (C). In the metal working oil composition of this embodiment, the content of calcium derived from the calcium-based detergent (C) is preferably 90 mass% or more, more preferably 95 mass% or more, and even more preferably 98 mass% or more, based on the total amount of calcium in the metal working oil composition.

[0018] <Requirement (4)> The metal working oil composition of the present embodiment is required to satisfy requirement (4) in addition to requirements (1), (2), and (3). That is, the metal processing oil composition of the present embodiment has a kinetic viscosity of 150 mm at 40°C. 2 / s or less. Kinematic viscosity at 40°C is 150mm 2 / s or less, it is possible to easily ensure the pump suction properties of the metal working oil composition. Here, the metal working oil composition preferably has a kinetic viscosity of 120 mm at 40°C. 2 / s or less, preferably 110 mm 2 / s or less, more preferably 100 mm 2 / s or less. The kinematic viscosity at 40° C. of the metal working oil composition of this embodiment means a value measured in accordance with JIS K2283:2000.

[0019] <Requirement (5)> The metal working oil composition of the present embodiment preferably satisfies requirement (5) in addition to requirements (1), (2), (3), and (4). That is, the metal processing oil composition of the present embodiment has a kinetic viscosity of 50 mm at 40°C. 2 It is preferable that the ratio is 1 / s or more. Kinematic viscosity at 40℃ is 50mm 2 / s or more, the flash point of the metal working oil composition can be more easily improved. In addition, the extreme pressure properties and lubricity resulting from the viscosity of the metal working oil composition can be improved, making it easier to suppress processing (molding) defects. Here, the kinematic viscosity of the metal working oil composition at 40°C is more preferably 55 mm 2 / s or more, more preferably 60 mm 2 / s or more.

[0020] <Base oil (A)> The metal working oil composition of the present embodiment contains a base oil (A). The base oil (A) may be a mineral oil or a synthetic oil.

[0021] Examples of mineral oils include atmospheric residual oils obtained by atmospheric distillation of paraffinic, naphthenic, or intermediate crude oils; distillate oils obtained by vacuum distillation of the atmospheric residual oils; and mineral oils refined by subjecting the distillate oils to one or more of the following treatments: solvent deasphalting, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, hydrorefining, etc., such as light neutral oil, medium neutral oil, heavy neutral oil, and bright stock. In addition, the mineral oil may be classified as any of Groups I, II, or III in the base oil category of the API (American Petroleum Institute). From the viewpoint of the solubility of the sulfur-based extreme pressure agent (B) and the calcium-based detergent (C) and, when the base oil (A) is a mixed base oil, from the viewpoint of the compatibility between the base oils, it is preferable to use a mineral oil classified as Group I.

[0022] Examples of synthetic oils include poly-α-olefins such as polybutene, ethylene-α-olefin copolymers, and α-olefin homopolymers or copolymers; various ester oils such as polyol esters, dibasic acid esters, and phosphate esters; various ethers such as polyphenyl ether; polyglycols; alkylbenzenes; alkylnaphthalenes; and GLT base oils obtained by isomerizing wax produced by the Fischer-Tropsch process or the like (GTL wax).

[0023] The base oil (A) may be any of the above mineral oils, either alone or in combination, or any of the above synthetic oils, or may be a mixed base oil consisting of one or more mineral oils and one or more synthetic oils.

[0024] Here, from the viewpoint of facilitating the preparation of a metal working oil composition satisfying the above requirement (1), the flash point of the base oil (A) as measured by the Cleveland open cup method is preferably 260°C or higher, more preferably 270°C or higher, and even more preferably 278°C or higher. In this embodiment, the flash point of the base oil (A) means a value measured by the Cleveland open cup measurement method in accordance with JIS K2265-4:2007.

[0025] Examples of the method for adjusting the flash point of the base oil (A) as measured by the Cleveland open cup method to fall within the above range include the following methods. ·Selection of base oil type -Adjustment of dynamic viscosity of base oil - Distillation of low-volatility components in base oil In this embodiment, it is preferable to appropriately employ the above-mentioned preparation method, etc., in order to adjust the flash point of the base oil (A) according to the Cleveland open cup measurement method to within the above-mentioned range, while taking into consideration the kinetic viscosity required for the metal working oil composition.

[0026] As described above, the metal working oil composition of the present embodiment satisfies the above requirement (4) as well as the above requirement (1), and preferably satisfies the above requirement (5). In the metal working oil composition of this embodiment, from the viewpoint of satisfying the above requirement (4) as well as the above requirement (1) and from the viewpoint of making it easier to satisfy the above requirement (5), the base oil (A) is preferably a mixed base oil. Specifically, it is preferable to use a mixed base oil prepared by mixing a high-viscosity base oil and a low-viscosity base oil to satisfy the above-mentioned requirement (1) and to adjust the kinetic viscosity of the metal working oil composition at 40°C to satisfy the above-mentioned requirement (4) (preferably further satisfying the above-mentioned requirement (5)). The kinematic viscosity of the high-viscosity base oil at 40°C is preferably 80mm 2 / s~500mm 2 / s, more preferably 90mm 2 / s~470mm 2 / s, more preferably 95 mm 2 / s~450mm 2 / s. The high viscosity base oil may be, for example, one or more selected from heavy neutral oils (for example, 500N mineral oil) and bright stock. The 40°C kinematic viscosity of the low-viscosity base oil is preferably 20mm 2 / s~80mm 2 / s, preferably less than 25 mm 2 / s~70mm 2 / s, more preferably 30 mm 2 / s~60mm2 / s. As the low-viscosity base oil, from the viewpoint of satisfying the above-mentioned range of kinematic viscosity at 40° C. and also satisfying the above-mentioned requirement (1), it is preferable to use a base oil having a flash point according to the Cleveland open cup measurement method of 260° C. or higher (preferably 270° C. or higher, more preferably 278° C. or higher). Examples of such base oils include ester oils and GTL base oils. These may be used alone or in combination of two or more.

[0027] <Sulfur-based extreme pressure agent (B)> The metal working oil composition of the present embodiment contains a sulfur-based extreme pressure agent (B). The metal working oil composition of the present embodiment contains a sulfur-based extreme pressure agent (B) together with a calcium-based detergent (C) and satisfies the requirements (2) and (3), thereby being able to have excellent extreme pressure properties. Examples of the sulfur-based extreme pressure agent (B) include sulfurized fats and oils, sulfurized fatty acids, sulfurized fatty acid esters, sulfurized olefins, sulfurized esters, and hydrocarbyl sulfides. These may be used alone or in combination of two or more.

[0028] Here, from the viewpoint of facilitating the preparation of a metal working oil composition satisfying the above requirement (2), the sulfur-based extreme pressure agent (B) preferably contains one or more selected from the group consisting of sulfurized oils and fats (B1) and sulfurized fatty acid esters (B2). The content of one or more selected from the group consisting of sulfurized oils and fats (B1) and sulfurized fatty acid esters (B2) in the sulfur-based extreme pressure agent (B) is preferably 50 mass% to 100 mass%, more preferably 60 mass% to 100 mass%, even more preferably 70 mass% to 100 mass%, still more preferably 80 mass% to 100 mass%, still more preferably 90 mass% to 100 mass%, and even more preferably 95 mass% to 100 mass%, based on the total amount of the sulfur-based extreme pressure agent (B).

[0029] (Sulfurized oil (B1)) The sulfurized fats and oils (B1) include sulfurized animal fats and oils and sulfurized vegetable fats and oils. Here, from the viewpoint of facilitating the preparation of a metal working oil composition satisfying the above-mentioned requirement (1), it is preferable to use a sulfurized oil containing a sulfurized vegetable oil as the sulfurized oil (B1), and it is particularly preferable to use a vegetable oil mainly composed of linoleic acid as the vegetable oil constituting the sulfurized vegetable oil. In the present embodiment, the term "vegetable oil containing linoleic acid as a main component" refers to vegetable oil in which the amount of linoleic acid in the total amount of fatty acids constituting the vegetable oil is 50 mass % or more. Examples of sulfurized vegetable oils using vegetable oils mainly containing linoleic acid include sulfurized grape seed oil, sulfurized corn oil, sulfurized cottonseed oil, and sulfurized soybean oil. The sulfurized oils and fats (B1) may be used alone or in combination of two or more.

[0030] (Sulfurized fatty acid ester (B2)) Examples of the sulfurized fatty acid ester (B2) include sulfurized fatty acid esters containing fatty acids derived from animal fats and oils, and sulfurized fatty acid esters containing fatty acids derived from vegetable fats and oils. Here, from the viewpoint of facilitating the preparation of a metal working oil composition satisfying the above-mentioned requirement (1), it is preferable to use, as the sulfurized fatty acid ester (B2), a sulfurized fatty acid ester containing a fatty acid derived from vegetable oil, and it is particularly preferable to use a sulfurized fatty acid ester containing a fatty acid derived from vegetable oil mainly composed of linoleic acid. Examples of sulfurized fatty acid esters containing fatty acids derived from vegetable oils and fats mainly composed of linoleic acid include sulfurized fatty acid esters containing fatty acids derived from grape seed oil, sulfurized fatty acid esters containing fatty acids derived from corn oil, sulfurized fatty acid esters containing fatty acids derived from cottonseed oil, and sulfurized fatty acid esters containing fatty acids derived from soybean oil. The sulfurized fatty acid ester (B2) may be used alone or in combination of two or more kinds.

[0031] (Flash point of sulfur-based extreme pressure agent (B)) The flash point of the sulfur-based extreme pressure agent (B) is preferably 150°C or higher, more preferably 160°C or higher, and even more preferably 170°C or higher, from the viewpoint of facilitating the preparation of a metal working oil composition that satisfies the above requirement (1). In the present embodiment, the flash point of the sulfur-based extreme pressure agent (B) refers to a value measured by the Cleveland open cup measurement method in accordance with JIS K2265-4:2007.

[0032] <Calcium-based detergent (C)> The metal working oil composition of the present embodiment contains a calcium-based detergent (C). The metal working oil composition of the present embodiment contains a calcium-based detergent (C) together with a sulfur-based extreme pressure agent (B) and satisfies the requirements (2) and (3), thereby being able to have excellent extreme pressure properties. In addition, Here, from the viewpoint of improving extreme pressure properties, the calcium-based detergent (C) preferably contains one or more selected from the group consisting of calcium sulfonate (C1), calcium phenate (C2), and calcium salicylate (C3). The content of one or more selected from the group consisting of calcium sulfonate (C1), calcium phenate (C2) and calcium salicylate (C3) in the calcium-based detergent (C) is preferably 50 mass% to 100 mass%, more preferably 60 mass% to 100 mass%, even more preferably 70 mass% to 100 mass%, still more preferably 80 mass% to 100 mass%, still more preferably 90 mass% to 100 mass%, and even more preferably 95 mass% to 100 mass%, based on the total amount of the calcium-based detergent (C).

[0033] The calcium sulfonate (C1) may be a compound represented by the following general formula (c1-1). Examples of calcium salicylate (C2) include compounds represented by the following general formula (c1-2). Examples of the calcium phenate (C3) include compounds represented by the following general formula (c1-3).

[0034] [ka]

[0035] In the above general formulas (c1-1) to (c1-3), R c1 , R c2 , R c3 , and R c4 are each independently a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms. q is an integer of 0 or more, and preferably an integer of 0 to 3. R c1 , R c2 , R c3 , and R c4 Examples of the hydrocarbon group that can be selected as the aryl group include an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 1 to 18 carbon atoms, a cycloalkyl group having 3 to 18 ring carbon atoms, an aryl group having 6 to 18 ring carbon atoms, an alkylaryl group having 7 to 18 carbon atoms, and an arylalkyl group having 7 to 18 carbon atoms.

[0036] Here, the calcium-based detergent (C) used in the metal working oil composition of this embodiment is required to have a base number of 300 mgKOH / g or more, from the viewpoint of increasing the calcium content derived from the calcium-based detergent (C) in the metal working oil composition by blending a small amount thereof and satisfying the requirement (3) and making it easier to improve the extreme pressure properties of the metal working oil composition. From the viewpoint of further improving the extreme pressure properties, the base number of the calcium-based detergent (C) is preferably 350 mgKOH / g or more, more preferably 400 mgKOH / g or more, and even more preferably 450 mgKOH / g or more. The upper limit of the base number of the calcium-based detergent (C) is not particularly limited, but is usually 600 mgKOH / g or less. In the present embodiment, the base number of the calcium-based detergent (C) means a value measured by potentiometric titration (base number-perchloric acid method) in accordance with JIS K2501:2003-9.

[0037] From the viewpoint of easy availability of high base number products and improvement of extreme pressure properties, the calcium-based detergent (C) preferably contains calcium sulfonate (C1). The base number of the calcium sulfonate (C1) must be 300 mgKOH / g or more, preferably 350 mgKOH / g or more, more preferably 400 mgKOH / g or more, and even more preferably 450 mgKOH / g or more, in order to increase the calcium content derived from the calcium-based detergent (C) (calcium sulfonate (C1)) in the metal working oil composition with a small amount of incorporation, and to facilitate further improvement of the extreme pressure properties of the metal working oil composition. The upper limit of the base number of the calcium sulfonate (C1) is not particularly limited, but is usually 600 mgKOH / g or less. When the calcium-based detergent (C) contains a calcium sulfonate (C1), the content of the calcium sulfonate (C1) in the calcium-based detergent (C) is preferably 50 mass% to 100 mass%, more preferably 60 mass% to 100 mass%, even more preferably 70 mass% to 100 mass%, still more preferably 80 mass% to 100 mass%, even more preferably 90 mass% to 100 mass%, and even more preferably 95 mass% to 100 mass%, based on the total amount of the calcium-based detergent (C).

[0038] <Ratio of sulfur content derived from component (B) to calcium content derived from component (C)> The content ratio of the sulfur content derived from component (B) to the calcium content derived from component (C) [sulfur content derived from component (B) / calcium content derived from component (C)] is preferably 0.19 to 0.29, and more preferably 0.20 to 0.28, in terms of mass ratio, from the viewpoints of improving the balance of the performance for suppressing oil smoke generation, the extreme pressure performance, and the solubility of components (B) and (C). Note that the content ratio of the sulfur content derived from component (B) to the calcium content derived from component (C) [sulfur content derived from component (B) / calcium content derived from component (C)] is synonymous with the content ratio of the sulfur content derived from component (B) to the calcium content in the metal working oil composition [sulfur content derived from component (B) / calcium content in metal working oil composition] when no calcium-containing component other than component (C) is blended in the metal working oil composition.

[0039] <Other ingredients> The metal working oil composition of the present embodiment may or may not contain components (other components) other than the sulfur-based extreme pressure agent (B) and the calcium-based detergent (C) within a range that does not significantly impair the effects of the present invention. Other components include antioxidants and antifoaming agents. These may be used alone or in combination of two or more.

[0040] [Physical properties of metalworking oil composition] The metal working oil composition of the present embodiment preferably satisfies the following physical properties.

[0041] <Extreme pressure resistance> The metal working oil composition of this embodiment preferably has a maximum non-seizure load (LNL) of more than 785 N, more preferably more than 981 N, as measured in the Shell EP test in the examples described below. Moreover, the metal working oil composition of this embodiment preferably has a weld load (WL) of more than 2452 N, more preferably more than 3089 N, as measured in the Shell EP test described below.

[0042] <Oil smoke generation> It is preferable that the metal working oil composition of this embodiment does not emit any oily smoke in the oily smoke confirmation test in the examples described below.

[0043] <Zinc content> The metal working oil composition of the present embodiment exhibits sufficient extreme pressure properties even without using a phosphorus- and zinc-containing compound such as zinc dithiophosphate. Therefore, the metal working oil composition of this embodiment may have a zinc content of less than 0.1 mass %, or less than 0.01 mass %, based on the total amount of the metal working oil composition, or may not contain zinc. Furthermore, from the viewpoint of reducing fatigue factors of tools such as dies used in metal processing, and from the viewpoint of preventing fatigue failure and brittle failure of manufactured parts, the metal processing oil composition of this embodiment preferably has a phosphorus content of less than 0.1 mass %, more preferably less than 0.01 mass %, and even more preferably contains no phosphorus, based on the total amount of the metal processing oil composition. The zinc content of the metal working oil composition of the present embodiment means a value measured in accordance with JPI-5S-28-27. The phosphorus content of the metal working oil composition of the present embodiment means a value measured in accordance with JPI-5S-38-03.

[0044] <Sulfur content> When the metal working oil composition of this embodiment contains a calcium sulfonate (C1) as the calcium-based detergent (C), the sulfur content of the metal working oil composition is, from the viewpoint of further improving the extreme pressure properties, preferably 0.80 mass% or more, more preferably 0.85 mass% or more, even more preferably 0.90 mass% or more, and still more preferably 0.95 mass% or more, based on the total amount of the metal working oil composition. Moreover, from the viewpoint of making it easier to suppress the generation of oil smoke from the metal working oil composition, the content is preferably 2.00 mass % or less, more preferably 1.50 mass % or less, and even more preferably 1.10 mass % or less. The upper and lower limits of these numerical ranges can be arbitrarily combined. Specifically, the range is preferably 0.80 mass% to 2.00 mass%, more preferably 0.85 mass% to 1.50 mass%, even more preferably 0.90 mass% to 1.10 mass%, and still more preferably 0.95 mass% to 1.10 mass%. In this embodiment, the sulfur content in the metal working oil composition means a value measured by wavelength dispersive X-ray fluorescence spectrometry in accordance with JIS K 2541-7:2013. When the calcium-based detergent (C) contains calcium sulfonate (B1), the sulfur content of the metal working oil composition of this embodiment mainly comes from the sulfur-based extreme pressure agent (B) and the calcium-based detergent (C). In the metal working oil composition of this embodiment, when the calcium-based detergent (C) contains a calcium sulfonate (B1), the total content of sulfur components derived from the sulfur-based extreme pressure agent (B) and the calcium sulfonate (B1) is preferably 80 mass% or more, more preferably 90 mass% or more, and even more preferably 95 mass% or more, based on the total amount of sulfur components in the metal working oil composition. When the calcium-based detergent (C) does not contain calcium sulfonate (B1), the sulfur content of the metal working oil composition of this embodiment is mainly derived from the sulfur-based extreme pressure agent (B). In this case, the sulfur content of the metal working oil composition of this embodiment may vary slightly due to trace amounts of sulfur that may be contained in the base oil, but it can be approximately equal to the sulfur content derived from the sulfur-based extreme pressure agent (B) (i.e., the above requirement (2)).

[0045] [Metalworking oil composition manufacturing method] The method for producing the metal working oil composition of the present embodiment is not particularly limited. For example, a method for producing a metal working oil composition of the present embodiment includes a step of mixing a base oil (A), a sulfur-based extreme pressure agent (B), and a calcium-based detergent (C) having a base number of 300 mgKOH / g or more so as to satisfy the following requirements (1), (2), (3), and (4). Requirement (1): The flash point, as determined by the Cleveland open cup test, is 260°C or higher. Requirement (2): The sulfur content derived from the sulfur-based extreme pressure agent (B) is 0.45 mass % or more based on the total amount of the metal working oil composition. Requirement (3): The calcium content is 1.0 mass % or more based on the total amount of the metal working oil composition. Requirement (4): Kinematic viscosity at 40°C is 150mm 2 / s or less.

[0046] In the method for producing a metal working oil composition of this embodiment, the sulfur-based extreme pressure agent (B) and the calcium-based detergent (C) may be blended into the base oil (A) simultaneously or separately. Furthermore, the other components may be blended simultaneously with the sulfur-based extreme pressure agent (B) and the calcium-based detergent (C) or may be blended separately. Each component may be mixed in the form of a solution (dispersion) by adding a diluent oil or the like. After mixing the components, it is preferable to stir them by a known method to disperse them uniformly. The preferred ranges of the above requirements (1), (2), (3), and (4), the method for adjusting the above requirements (1), (2), (3), and (4), and the preferred aspects of each of the above components are as described above. In the method for producing a metal working oil composition of this embodiment, it is also preferable that the above requirement (5) is satisfied. The preferred range of the above requirement (5) is also as described above.

[0047] [Uses of metalworking oil composition] The metal working oil composition of the present embodiment is excellent in extreme pressure properties and also in the performance of suppressing the generation of oily smoke. Therefore, the metal working oil composition of the present embodiment can be used in general metal working applications where it is required to suppress the generation of oily smoke while suppressing seizure between a metal workpiece and a tool, and among metal working applications, it can be preferably used in plastic working, and more preferably used in drawing. Therefore, the metal working oil composition of the present embodiment provides the following (I) and (II). (I) A method for using the metal working oil composition of the present embodiment, which comprises using the metal working oil composition for plastic working. (II) A method for using the metal working oil composition of the present embodiment, which comprises using the metal working oil composition for drawing. Moreover, the metal working oil composition of the present embodiment can be suitably used as a plastic working oil, and can be more suitably used as a pressure forming oil. The metal working oil composition of the present embodiment is not intentionally mixed with water for use. Therefore, the water content of the metal working oil composition of the present embodiment is preferably less than 1.0 mass%, more preferably less than 0.1 mass%, and even more preferably less than 0.01 mass%, based on the total amount of the metal working oil composition.

[0048] [One aspect of the present invention provided] In one embodiment of the present invention, the following [1] to

[11] are provided. [1] A metalworking oil composition comprising a base oil (A), a sulfur-based extreme pressure agent (B), and a calcium-based detergent (C) having a base number of 300 mgKOH / g or more, and satisfying the following requirements (1), (2), (3), and (4): Requirement (1): The flash point, as determined by the Cleveland open cup test, is 260°C or higher. Requirement (2): The sulfur content derived from the sulfur-based extreme pressure agent (B) is 0.45 mass % or more based on the total amount of the metal working oil composition. Requirement (3): The calcium content is 1.0 mass % or more based on the total amount of the metal working oil composition. Requirement (4): Kinematic viscosity at 40°C is 150mm 2 / s or less. [2] The metal working oil composition according to the above item [1], further satisfying the following requirement (6): Requirement (5): Kinematic viscosity at 40°C is 50mm 2 / s or more. [3] The metal working oil composition according to the above [1] or [2], wherein the sulfur-based extreme pressure agent (B) comprises one or more selected from the group consisting of sulfurized oils and fats (B1) and sulfurized fatty acid esters (B2). [4] The metal working oil composition according to any one of the above [1] to [3], wherein the calcium-based detergent (C) comprises one or more selected from the group consisting of calcium sulfonate (C1), calcium phenate (C2), and calcium salicylate (C3). [5] The metal working oil composition according to any one of the above [1] to [4], wherein the sulfur content derived from the sulfur-based extreme pressure agent (B) is 0.75 mass% or less based on the total amount of the metal working oil composition. [6] The metal working oil composition according to any one of the above [1] to [5], having a calcium content of 3.5 mass % or less based on the total amount of the metal working oil composition. [7] The calcium-based detergent (C) contains a calcium sulfonate (C1), The metal working oil composition according to any one of the above [1] to [6], wherein the sulfur content in the metal working oil composition is 0.80 mass % or more based on the total amount of the metal working oil composition. [8] The metal working oil composition according to any one of the above [1] to [7], further comprising one or more additives selected from the group consisting of antioxidants and antifoaming agents. [9] The metal working oil composition according to any one of the above [1] to [8], which is used in plastic working.

[10] The metal working oil composition according to the above [9], wherein the plastic working is drawing.

[11] A method for producing a metal working oil composition, comprising: mixing a base oil (A), a sulfur-based extreme pressure agent (B), and a calcium-based detergent (C) having a base number of 300 mg KOH / g or more so as to satisfy the following requirements (1), (2), (3), and (4): Requirement (1): The flash point, as determined by the Cleveland open cup test, is 260°C or higher. Requirement (2): The sulfur content derived from the sulfur-based extreme pressure agent (B) is 0.45 mass % or more based on the total amount of the metal working oil composition. Requirement (3): The calcium content is 1.0 mass % or more based on the total amount of the metal working oil composition. Requirement (4): Kinematic viscosity at 40°C is 150mm 2 / s or less. EXAMPLES

[0049] The present invention will be specifically described with reference to the following examples, although the present invention is not limited to the following examples.

[0050] [Methods for measuring various physical properties] The properties of the raw materials used in each Example and Comparative Example and the metal working oil compositions in each Example and Comparative Example were measured according to the procedures described below.

[0051] (1) Kinematic viscosity at 40°C Measurements were performed in accordance with JIS K2283:2000. (2) Flash point Measurements were performed using the Cleveland open cup measurement method in accordance with JIS K2265-4:2007.

[0052] [Examples 1 to 4 and Comparative Examples 1 to 5] The above components were mixed to prepare metal working oil compositions having the compositions shown in Table 1, and the following evaluations were carried out. The numerical units for the blend compositions in Table 1 are "mass %." The details of each component used in preparing the metal working oil composition having the composition shown in Table 1 are described below.

[0053] <Base oil (A)> ·"GTL base oil": Flash point 262℃, kinematic viscosity 43.75mm at 40℃ 2 / s, low viscosity base oil "High viscosity mineral oil": Bright stock, flash point 324℃, kinematic viscosity at 40℃ 435.1mm 2 / s, API Classification Group I, high viscosity base oil "Ester base oil": Pentaerythritol saturated fatty acid ester, flash point 280℃, kinetic viscosity 33.50mm at 40℃ 2 / s, low viscosity base oil ·"500N Mineral Oil": Flash point 260℃, kinematic viscosity 102.5mm at 40℃ 2 / s, API Classification Group I, high viscosity base oil ·"150N Mineral Oil": Flash point 214℃, kinematic viscosity 29.5mm at 40℃ 2 / s, API classification group I, low viscosity base oil

[0054] <Sulfur-based extreme pressure agent (B)> "Sulfurized fats and oils (B1-1)": Sulfurized mixture of animal fats and oils, glyceride oils, and vegetable fats and oils, flash point 180℃ "Sulfurized oil (B1-2)": a sulfurized oil composition mainly composed of sulfurized lard oil (97% by mass), flash point 145°C "Sulfurized fatty acid ester (B2)": Sulfurized methyl ester of vegetable oil fatty acid, flash point 202℃

[0055] <Calcium-based detergent (C)> "Calcium sulfonate (C1)": A product with a base number of 500 mg KOH / g and containing 51.5 mass% of highly hydrogenated heavy paraffin oil distillate was used. "Calcium phenate (C3)": A product with a base number of 300 mg KOH / g and containing 43% by mass of highly hydrogenated heavy paraffinic oil distillate was used.

[0056] <Calcium-based detergent (C')> "Calcium sulfonate (C'1)": A product with a base number of 150 mg KOH / g and containing 45-50 mass% highly refined mineral oil (carbon number 15-50) was used.

[0057] <Other ingredients> Amine antioxidants (diphenylamine antioxidants), antifoaming agents

[0058] [Evaluation 1: Shell EP Test] The metalworking oil compositions of Examples 1 to 4 and Comparative Examples 1 to 5 were subjected to a Shell EP test in accordance with ASTM D2783 using a four-ball tester at a rotation speed of 1,760±40 rpm and an oil temperature of 18.3 to 35.0° C. to measure the maximum non-seizure load (LNL) and weld load (WL). The larger these values ​​are, the more excellent the extreme pressure properties are. In this example, a specimen was deemed to pass if the maximum non-seizure load (LNL) was more than 785 N and the welding load (WL) was more than 2452 N. A specimen that passed was marked with "A" in Table 1, and a specimen that failed was marked with "F" in Table 1.

[0059] [Evaluation 2: Oil smoke generation evaluation test] 0.5 mL of each of the metalworking oil compositions of Examples 1 to 4 and Comparative Examples 1 to 5 was dropped into an aluminum cup heated to 250°C, and immediately covered with a 300 mL beaker. After 60 seconds, it was visually confirmed whether oil smoke was generated in the beaker. The temperature of the aluminum cup was maintained at 250°C during the test. In this example, a sample that did not generate oil smoke was judged to pass. A pass was indicated with "A" in Table 1, and a fail was indicated with "F" in Table 1.

[0060] The evaluation results are shown in Table 1. The calcium content of the metalworking oil composition was measured by inductively coupled plasma emission spectrometry in accordance with JPI-5S-38-03. The sulfur content of the metalworking oil composition was measured by wavelength-dispersive X-ray fluorescence in accordance with JIS K 2541-7:2013. The sulfur content derived from the sulfur-based extreme pressure agent (B) was measured in accordance with JIS K 2541-7:2013 after dissolving a predetermined amount of the sulfur-based extreme pressure agent (B) in a sulfur-free base oil, and was calculated based on the sulfur content in the sulfur-based extreme pressure agent (B) calculated from the measured value and the amount of (B) added.

[0061] [Table 1]

[0062] From Table 1, we can see the following: It can be seen that the metal processing oil compositions of Examples 1 to 4, which contain the above components (A) to (C) and satisfy all of the above requirements (1) to (4), have excellent extreme pressure properties and excellent performance in suppressing the generation of oily smoke, while having their kinetic viscosities adjusted to a low level below a certain value. In contrast, it is clear that the metal working oil compositions of Comparative Examples 1 and 2, which do not satisfy the above requirement (1), are insufficient in terms of the performance of suppressing the generation of oily smoke. Moreover, it is clear that the metal working oil compositions of Comparative Examples 3 and 4, which do not satisfy the above requirement (2), have insufficient extreme pressure properties. Furthermore, it is also clear that the metal working oil composition of Comparative Example 5, which does not satisfy the above requirement (3), has insufficient extreme pressure properties.

Claims

1. A metal working oil composition comprising a base oil (A), a sulfur-based extreme pressure agent (B), and a calcium-based detergent (C) having a base number of 300 mgKOH / g or more, and satisfying the following requirements (1), (2), (3), and (4): Requirement (1): The flash point measured by the Cleveland open cup method is 260°C or higher. Requirement (2): The sulfur content derived from the sulfur-based extreme pressure agent (B) is 0.45 mass % or more based on the total amount of the metal working oil composition. Requirement (3): The calcium content is 1.0 mass % or more based on the total amount of the metal working oil composition. Requirement (4): Kinematic viscosity at 40 ° C. is 150 mm ２ / s or less.

2. The metal working oil composition according to claim 1, further satisfying the following requirement (5): Requirement (5): Kinematic viscosity at 40 ° C. is 50 mm ２ / s or more.

3. 3. The metal working oil composition according to claim 1, wherein the sulfur-based extreme pressure agent (B) comprises one or more selected from the group consisting of sulfurized oils and fats (B1) and sulfurized fatty acid esters (B2).

4. 3. The metal working oil composition according to claim 1, wherein the calcium-based detergent (C) comprises one or more selected from the group consisting of calcium sulfonate (C1), calcium phenate (C2), and calcium salicylate (C3).

5. 3. The metal working oil composition according to claim 1, wherein the content of sulfur derived from the sulfur-based extreme pressure agent (B) is 0.75 mass% or less based on the total amount of the metal working oil composition.

6. 3. The metal working oil composition according to claim 1, wherein the calcium content is 3.5 mass % or less based on the total amount of the metal working oil composition.

7. The calcium-based detergent (C) contains a calcium sulfonate (C1), 3. The metal working oil composition according to claim 1, wherein the sulfur content in the metal working oil composition is 0.80 mass % or more based on the total amount of the metal working oil composition.

8. 3. The metal working oil composition according to claim 1, further comprising one or more additives selected from the group consisting of antioxidants and antifoaming agents.

9. The metal working oil composition according to claim 1 or 2, which is used in plastic working.

10. The metal working oil composition according to claim 9, wherein the plastic working is drawing.

11. A method for producing a metal working oil composition, comprising: mixing a base oil (A), a sulfur-based extreme pressure agent (B), and a calcium-based detergent (C) having a base number of 300 mgKOH / g or more so as to satisfy the following requirements (1), (2), (3), and (4): Requirement (1): The flash point measured by the Cleveland open cup method is 260°C or higher. Requirement (2): The sulfur content derived from the sulfur-based extreme pressure agent (B) is 0.45 mass % or more based on the total amount of the metal working oil composition. Requirement (3): The calcium content is 1.0 mass % or more based on the total amount of the metal working oil composition. Requirement (4): Kinematic viscosity at 40 ° C. is 150 mm ２ / s or less.