Water-soluble metalworking oil

Abstract

To provide a new water-soluble metalworking oil agent which has improved performance in various ways so that it can be more easily applied to metalworking than conventional emulsion or soluble oil agents. [Solution] A water-soluble metalworking oil agent contains a base oil (A) containing an oil-soluble polyalkylene glycol (A1), and the total content of the water-soluble polyalkylene glycol and methoxypolyethylene glycol is less than 60 mass% based on the total amount excluding water.

Description

[Technical Field]

[0001] The present invention relates to a water-soluble metalworking oil, a metalworking fluid obtained by blending the water-soluble metalworking oil with dilution water, and a metalworking method for applying the metalworking fluid to workpieces made of metal. [Background technology]

[0002] BACKGROUND ART In the field of metalworking such as cutting and grinding, metalworking fluids are used for the purposes of improving the workability of workpieces and suppressing wear of working tools. Metalworking fluids include oil-based fluids, which are primarily composed of oils such as mineral oils, synthetic oils, and animal and vegetable oils, and water-soluble fluids, which are made water-soluble by blending oils with surfactant compounds. In recent years, water-soluble metalworking fluids have become more popular for safety reasons, such as a lower risk of fire.

[0003] For example, Patent Document 1 discloses an invention relating to a concentrated metalworking fluid containing 60 to 90% by weight of a base oil selected from the group consisting of water-soluble polyalkylene glycols, methoxypolyethylene glycols, and combinations of two or more thereof, 5 to 20% by weight of a glycol ether, 0.01 to 5% by weight of an oil-soluble polyalkylene glycol, and 0.2 to 6% by weight of an additive. Furthermore, Patent Document 2 discloses an invention relating to a water-soluble processing oil containing methyldicyclohexylamine. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2014 / 089766 [Patent Document 2] International Publication No. 2010 / 113594 Summary of the Invention [Problem to be solved by the invention]

[0005] Under these circumstances, there is a demand for new water-soluble metalworking fluids that have improved performance in various areas so that they can be more easily applied to metalworking than conventional fluids, for example, emulsion-type or soluble-type fluids. [Means for solving the problem]

[0006] The present invention provides a water-soluble metalworking fluid containing an oil-soluble polyalkylene glycol as a base oil, and containing not more than a predetermined amount of water-soluble polyalkylene glycol and methoxypolyethylene glycol. Specifically, the present invention provides, for example, the following aspects [1] to

[16] . [1] A base oil (A) containing an oil-soluble polyalkylene glycol (A1), A water-soluble metalworking fluid having a total content of water-soluble polyalkylene glycol and methoxypolyethylene glycol of less than 60 mass% based on the total amount excluding water. [2] The water-soluble metalworking oil according to [1] above, wherein the total content of the water-soluble polyalkylene glycol and methoxypolyethylene glycol is less than 10 parts by mass per 100 parts by mass of the total amount of component (A1). [3] The water-soluble metalworking oil according to [1] or [2] above, which is substantially free of sulfur-based extreme pressure agents. [4] The water-soluble metalworking fluid according to any one of the above [1] to [3], further comprising water (B). [5] The water-soluble metalworking oil according to any one of the above [1] to [4], wherein the content of component (A1) in component (A) is 10 to 100 mass% based on the total amount of component (A) contained in the water-soluble metalworking oil. [6] The water-soluble metalworking fluid according to any one of the above [1] to [5], wherein the content of component (A1) is 0.01 mass% or more based on the total amount of the water-soluble metalworking fluid excluding water. [7] The water-soluble metalworking fluid according to any one of the above [1] to [6], further comprising an amine compound (C). [8] The water-soluble metalworking fluid according to any one of the above [1] to [7], further comprising a fatty acid (D). [9] The water-soluble metalworking fluid according to any one of the above [1] to [8], further comprising a nonionic surfactant (E).

[10] The water-soluble metalworking oil according to any one of [1] to [9] above, which is an emulsion-type oil classified as Type A1 according to JIS K2241:2017.

[11] The water-soluble metalworking oil according to any one of [1] to [9] above, which is a soluble oil classified as type A2 according to JIS K2241:2017.

[12] A base oil (A) containing an oil-soluble polyalkylene glycol (A1), A water-soluble metalworking fluid in which the total content of water-soluble polyalkylene glycol and methoxypolyethylene glycol is less than 10 parts by mass per 100 parts by mass of the total amount of component (A).

[13] A metalworking fluid obtained by blending dilution water with the water-soluble metalworking oil agent according to any one of the above [1] to

[12] .

[14] A metalworking method, comprising applying the metalworking fluid according to

[13] above to a workpiece made of metal.

[15] The metal processing method according to

[14] above, wherein the workpiece has a member containing at least iron or aluminum.

[16] The metal processing method according to

[14] or

[15] above, which inhibits corrosion of copper-containing members constituting a processing machine used to process the workpiece. [Effects of the Invention]

[0007] The water-soluble metalworking fluid in one preferred embodiment of the present invention can be diluted with dilution water to prepare a metalworking fluid excellent in various properties such as workability. DETAILED DESCRIPTION OF THE INVENTION

[0008] Regarding the numerical ranges described herein, the upper and lower limits can be combined in any combination. For example, when a numerical range is described as "preferably 30 to 100, more preferably 40 to 80," the ranges "30 to 80" and "40 to 100" are also included in the numerical ranges described herein. Furthermore, when a numerical range is described as "preferably 30 or more, more preferably 40 or more, and preferably 100 or less, more preferably 80 or less," the ranges "30 to 80" and "40 to 100" are also included in the numerical ranges described herein. In addition, as a numerical range described in this specification, for example, "60 to 100" means a range of "60 or more and 100 or less."

[0009] In this specification, "metalworking oil" refers to a stock solution of a metalworking fluid before it is diluted with dilution water to form a metalworking fluid, and is in a form suitable for transportation and storage before use in metalworking. Also, "metalworking fluid" refers to a metalworking fluid that is obtained by diluting a stock solution of a metalworking oil with dilution water, and is in a form suitable for use in metalworking. "Metalworking oils" and "metalworking fluids" can also be distinguished, for example, by the water content, as follows: "Metalworking oil": The water content is between 0 and 400 parts by mass per 100 parts by mass of the total amount of ingredients other than water. - "Metalworking fluid": The water content exceeds 400 parts by mass per 100 parts by mass of the total amount of ingredients other than water.

[0010] [Configuration of water-soluble metalworking oil] The water-soluble metalworking oil of the present invention contains a base oil (A) that includes an oil-soluble polyalkylene glycol (hereinafter also referred to as "oil-soluble PAG") (A1), and the total content of the water-soluble polyalkylene glycol (hereinafter also referred to as "water-soluble PAG") and methoxypolyethylene glycol (hereinafter also referred to as "MPEG") is adjusted to a predetermined content. In this specification, "water-soluble" means a component that dissolves in an amount of 20 g or more in 100 g of water at 25°C, and that has a total light transmittance of 90% or more at 25°C when prepared by adding 20 g of the target substance to 100 g of water at 25°C. In the following description of this specification, a component described as "water-soluble" is a component having the above-mentioned properties.

[0011] In the water-soluble metalworking oil of one embodiment of the present invention, the total content of the water-soluble PAG and MPEG may be less than 60 mass%, less than 50 mass%, less than 40 mass%, less than 30 mass%, less than 20 mass%, less than 10 mass%, less than 5 mass%, less than 1 mass%, or less than 0.1 mass%, based on the total amount (100 mass%) excluding water.

[0012] In the water-soluble metalworking oil according to one embodiment of the present invention, the total content of the water-soluble PAG and MPEG may be less than 10 parts by mass, less than 5 parts by mass, less than 1 part by mass, less than 0.1 part by mass, less than 0.01 part by mass, or less than 0.001 part by mass, relative to 100 parts by mass of the total amount of component (A1).

[0013] The water-soluble metalworking oil according to one embodiment of the present invention may further contain water (B). By adjusting the content of water (B), the water-soluble metalworking oil can be prepared into an emulsion-type oil classified as Class A1 or a soluble-type oil classified as Class A2, as specified in JIS K2241:2017.

[0014] The water-soluble metalworking oil according to one embodiment of the present invention preferably contains one or more selected from the group consisting of an amine compound (C), a fatty acid (D), and a nonionic surfactant (E), more preferably contains at least components (C) and (D), and even more preferably contains all of components (C), (D), and (E). The water-soluble metalworking oil agent according to one embodiment of the present invention may contain components other than the components (A) to (E) to the extent that the effects of the present invention are not impaired.

[0015] In the water-soluble metalworking oil according to one embodiment of the present invention, the total content of components (A) and (B) is, based on the total amount (100% by mass) of the water-soluble metalworking oil, preferably 20% by mass or more, more preferably 30% by mass or more, even more preferably 40% by mass or more, still more preferably 45% by mass or more, and particularly preferably 50% by mass or more, and may also be 100% by mass or less, 95% by mass or less, 90% by mass or less, 85% by mass or less, 80% by mass or less, 75% by mass or less, 70% by mass or less, 65% by mass or less, or 60% by mass or less.

[0016] In the water-soluble metalworking oil according to one embodiment of the present invention, the total content of components (A) to (D) is, based on the total amount (100% by mass) of the water-soluble metalworking oil, preferably 30% by mass or more, more preferably 40% by mass or more, more preferably 50% by mass or more, even more preferably 60% by mass or more, still more preferably 70% by mass or more, and particularly preferably 80% by mass or more, and may also be 100% by mass or less, 98% by mass or less, 95% by mass or less, 93% by mass or less, or 90% by mass or less.

[0017] In the water-soluble metalworking oil according to one embodiment of the present invention, the total content of components (A) to (E) is, based on the total amount (100% by mass) of the water-soluble metalworking oil, preferably 35% by mass or more, more preferably 45% by mass or more, more preferably 55% by mass or more, even more preferably 65% ​​by mass or more, still more preferably 75% by mass or more, and particularly preferably 85% by mass or more, and may also be 100% by mass or less, 98% by mass or less, 96% by mass or less, or 94% by mass or less. Hereinafter, each component contained in the water-soluble metalworking oil agent according to one embodiment of the present invention will be described.

[0018] <Component (A): Base oil> The water-soluble metalworking fluid of the present invention contains a base oil (A) containing an oil-soluble PAG (A1). The water-soluble metalworking fluid of the present invention contains an oil-soluble PAG as a base oil, and therefore can improve the workability of a metalworking fluid obtained by blending the water-soluble metalworking fluid with dilution water. Generally, to obtain a metalworking fluid with excellent workability (particularly for iron-containing workpieces), the water-soluble metalworking fluid used as the base solution contains a sulfur-based extreme pressure agent. However, sulfur-based extreme pressure agents can cause corrosion of copper-containing components constituting the processing machine used for metalworking the workpiece. On the other hand, by containing component (A1), the water-soluble metalworking fluid of the present invention can be prepared into a metalworking fluid with excellent workability even without substantially containing a sulfur-based extreme pressure agent, and the problem of corrosion of copper components can also be avoided.

[0019] The component (A) used in one embodiment of the present invention may contain a base oil (A2) other than the component (A1). However, from the viewpoint of obtaining a water-soluble metalworking oil that can become a metalworking fluid with excellent workability, the content of component (A1) in component (A) in the water-soluble metalworking oil of one embodiment of the present invention may be 10 to 100 mass%, 20 to 100 mass%, 30 to 100 mass%, 40 to 100 mass%, 50 to 100 mass%, 60 to 100 mass%, 70 to 100 mass%, 75 to 100 mass%, 80 to 100 mass%, 85 to 100 mass%, 90 to 100 mass%, 95 to 100 mass%, or 98 to 100 mass% based on the total amount (100 mass%) of component (A) contained in the water-soluble metalworking oil.

[0020] In the water-soluble metalworking fluid according to one aspect of the present invention, the content of component (A) is, based on the total amount (100 mass%) of the water-soluble metalworking fluid excluding water, preferably 0.01 mass% or more, more preferably 0.05 mass% or more, more preferably 0.1 mass% or more, more preferably 0.5 mass% or more, more preferably 1.0 mass% or more, even more preferably 1.5 mass% or more, even more preferably 2.0 mass% or more, even more preferably 2.5 mass% or more, and even more preferably 3.0 mass% from the viewpoint of obtaining a water-soluble metalworking fluid that can be a metalworking fluid with excellent workability. It is preferably 4.0% by mass or more, even more preferably 5.0% by mass or more, even more preferably 6.0% by mass or more, even more preferably 7.0% by mass or more, even more preferably 8.0% by mass or more, and particularly preferably 9.0% by mass or more, and may further be 9.5% by mass or more, 10.0% by mass or more, 11.0% by mass or more, or 12.0% by mass or more, and may also be 100% by mass or less, 99% by mass or less, 95% by mass or less, 90% by mass or less, 85% by mass or less, 80% by mass or less, 75% by mass or less, or 70% by mass or less.

[0021] When the emulsion-type oil agent is classified as Type A1 as specified in JIS K2241:2017, the content of component (A) may be 10% by mass or more, 15% by mass or more, 20% by mass or more, 30% by mass or more, 40% by mass or more, 45% by mass or more, or 50% by mass or more based on the total amount (100% by mass) of the oil agent excluding water, with the upper limit as described above.

[0022] When a soluble oil agent classified as Type A2 as specified in JIS K2241:2017 is used, the content of component (A) may be 60% by mass or less, 50% by mass or less, 40% by mass or less, 30% by mass or less, 25% by mass or less, or 20% by mass or less, based on the total amount (100% by mass) of the oil agent excluding water, and the lower limit is as described above.

[0023] Furthermore, in the water-soluble metalworking fluid according to one aspect of the present invention, the content of component (A) is, based on the total amount (100% by mass) of the water-soluble metalworking fluid, preferably 0.01% by mass or more, more preferably 0.05% by mass or more, more preferably 0.1% by mass or more, more preferably 0.3% by mass or more, more preferably 0.5% by mass or more, even more preferably 0.7% by mass or more, even more preferably 1.0% by mass or more, even more preferably 1.5% by mass or more, even more preferably 2.0% by mass or more, and even more preferably 3.0% by mass or more, based on the total amount (100% by mass) of the water-soluble metalworking fluid, from the viewpoint of providing a water-soluble metalworking fluid that can be a metalworking fluid with excellent workability. It is preferably 2.5% by mass or more, even more preferably 3.0% by mass or more, even more preferably 3.5% by mass or more, and particularly preferably 4.0% by mass or more, and may further be 4.5% by mass or more, 5.0% by mass or more, 5.5% by mass or more, 6.0% by mass or more, 6.5% by mass or more, or 7.0% by mass or more. It is also 100% by mass or less, but taking into consideration the content of other components, it may be 99% by mass or less, 95% by mass or less, 90% by mass or less, 85% by mass or less, 80% by mass or less, 75% by mass or less, 70% by mass or less, 65% by mass or less, or 60% by mass or less.

[0024] When the emulsion-type oil agent is classified as Type A1 as specified in JIS K2241:2017, the content of component (A) may be 10% by mass or more, 15% by mass or more, 20% by mass or more, 30% by mass or more, 40% by mass or more, 45% by mass or more, or 50% by mass or more based on the total amount of the oil agent (100% by mass), with the upper limit as described above.

[0025] When a soluble oil agent classified as Type A2 as specified in JIS K2241:2017 is used, the content of component (A) may be 60% by mass or less, 50% by mass or less, 40% by mass or less, 30% by mass or less, 25% by mass or less, 20% by mass or less, 15% by mass or less, or 10% by mass or less based on the total amount of the oil agent (100% by mass), and the lower limit is as described above.

[0026] <Component (A1): Oil-soluble polyalkylene glycol (oil-soluble PAG)> The component (A1) used in one embodiment of the present invention is not particularly limited as long as it is a polyalkylene glycol (PAG) that has structural units derived from alkylene oxide and exhibits oil solubility. In this specification, whether a PAG is oil-soluble or not is determined based on its miscibility with mineral oil classified as Group 1 of the API (American Petroleum Institute) base oil category. Specifically, samples are prepared in which the content ratio of a control PAG to a mineral oil classified as Group 1 [PAG / mineral oil] is 10 / 90 or 90 / 10 by mass, and the total light transmittance of the sample and a standard sample at 25°C is measured. If the following criteria (i) and (ii) are met, the PAG is determined to be oil-soluble. (i) In the case of a sample with a content ratio [PAG / mineral oil]=10 / 90, [total light transmittance (%) of the sample]−[total light transmittance (%) of the mineral oil alone]≦20%. (ii) In the case of a sample with a content ratio [PAG / mineral oil]=90 / 10, [total light transmittance (%) of the sample]−[total light transmittance (%) of the PAG]≦20%. In the following description of this specification, unless otherwise specified, a component described as "oil-soluble" is a component that satisfies the above criteria (i) and (ii).

[0027] Component (A1) used in one embodiment of the present invention includes a polymer having structural units derived from at least one of propylene oxide and butylene oxide, such as a propylene oxide homopolymer, a butylene oxide homopolymer, and a propylene oxide-butylene oxide copolymer. The component (A1) may be used alone or in combination of two or more types.

[0028] The kinematic viscosity at 40°C of the component (A1) used in one aspect of the present invention is preferably 9 to 800 mm from the viewpoint of providing a water-soluble metalworking fluid that can be used as a metalworking fluid with excellent workability. 2 / s, preferably 15 to 350 mm 2 / s, more preferably 20 to 250 mm 2 / s, more preferably 23 to 180 mm2 / s, and even more preferably 25 to 100 mm 2 / s, and even more preferably 28.8 to 90 mm 2 / s, particularly preferably 40 to 80 mm 2 / s.

[0029] Furthermore, from the viewpoint of providing a water-soluble metalworking oil that can be used as a metalworking fluid with excellent workability, the viscosity grade specified by ISO 3448 of component (A1) used in one embodiment of the present invention is preferably VG10, VG15, VG22, VG32, VG46, VG68, VG100, VG150, VG220, VG320, VG460, or VG680, more preferably VG22, VG32, VG46, VG68, or VG100, even more preferably VG32, VG46, or VG68, still more preferably VG46 or VG68, and particularly preferably VG68.

[0030] In the water-soluble metalworking fluid of one aspect of the present invention, the content of component (A1) is, based on the total amount (100 mass%) of the water-soluble metalworking fluid excluding water, preferably 0.01 mass% or more, more preferably 0.05 mass% or more, more preferably 0.1 mass% or more, more preferably 0.5 mass% or more, more preferably 1.0 mass% or more, even more preferably 1.5 mass% or more, even more preferably 2.0 mass% or more, even more preferably 2.5 mass% or more, even more preferably 3.0 mass% or more, and still more preferably 4.0 mass% or more, from the viewpoint of obtaining a water-soluble metalworking fluid that can be a metalworking fluid with excellent workability. or 4.0% by mass or more, even more preferably 5.0% by mass or more, even more preferably 6.0% by mass or more, even more preferably 7.0% by mass or more, even more preferably 8.0% by mass or more, and particularly preferably 9.0% by mass or more, and may further be 9.5% by mass or more, 10.0% by mass or more, 11.0% by mass or more, or 12.0% by mass or more. Although it is 100% by mass or less, taking into consideration the contents of other components, it may be 95% by mass or less, 90% by mass or less, 85% by mass or less, 80% by mass or less, 75% by mass or less, 70% by mass or less, or 65% by mass or less.

[0031] When the emulsion-type oil agent is classified as Type A1 as specified in JIS K2241:2017, the content of component (A1) may be 10% by mass or more, 15% by mass or more, 20% by mass or more, 30% by mass or more, 40% by mass or more, 45% by mass or more, or 50% by mass or more based on the total amount (100% by mass) of the oil agent excluding water, with the upper limit as described above.

[0032] When a soluble oil agent classified as type A2 according to JIS K2241:2017 is used, the content of component (A1) may be 60% by mass or less, 50% by mass or less, 40% by mass or less, 30% by mass or less, 25% by mass or less, or 20% by mass or less, based on the total amount (100% by mass) of the oil agent excluding water, and the lower limit is as described above.

[0033] <Component (A2): Base oil other than component (A1)> The base oil (A2) other than the component (A1) used in one embodiment of the present invention may be at least one selected from mineral oils and synthetic oils other than oil-soluble PAGs. In this specification, the above-mentioned water-soluble polyalkylene glycol (water-soluble PAG) and methoxypolyethylene glycol (MPEG) are also included in component (A2), and the total content of the water-soluble PAG and MPEG is adjusted as described above.

[0034] Examples of mineral oils include atmospheric residues obtained by atmospheric distillation of crude oils such as paraffinic crude oil, intermediate crude oil, and naphthenic crude oil; distillates obtained by vacuum distillation of these atmospheric residues; and refined oils obtained by subjecting the distillates to one or more refining processes such as solvent deasphalting, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, and hydrorefining.

[0035] Examples of synthetic oils include poly-α-olefins such as α-olefin homopolymers or α-olefin copolymers (e.g., α-olefin copolymers having 8 to 14 carbon atoms, such as ethylene-α-olefin copolymers); isoparaffins; ester-based oils such as polyol esters, dibasic acid esters, and phosphate esters; ether-based oils such as polyphenyl ethers; alkylbenzenes; alkylnaphthalenes; and synthetic oils (GTL) obtained by isomerizing wax produced from natural gas by the Fischer-Tropsch process or the like (GTL wax (Gas to Liquids Wax)).

[0036] The kinematic viscosity at 40°C of the component (A2) used in one aspect of the present invention is preferably 2.0 to 150 mm from the viewpoint of providing a water-soluble metalworking fluid that can be used as a metalworking fluid with excellent workability. 2 / s, preferably 3.0 to 120 mm 2 / s, more preferably 5.0 to 100 mm 2 / s, and even more preferably 6.0 to 90 mm 2 / s, particularly preferably 7.0 to 80 mm 2 / s. Furthermore, the viscosity index of component (A2) used in one embodiment of the present invention is preferably 70 or greater, more preferably 80 or greater, even more preferably 90 or greater, still more preferably 100 or greater, and particularly preferably 105 or greater.

[0037] <Ingredient (B): Water> The water-soluble metalworking fluid of one embodiment of the present invention may further contain water (B). By making the water-soluble metalworking fluid contain water, it is possible to impart flame retardancy to the fluid, making it non-hazardous and improving the handling properties during storage. The water as component (B) used in one embodiment of the present invention is not particularly limited, and may be, for example, distilled water, ion-exchanged water, tap water, industrial water, or the like.

[0038] In the water-soluble metalworking oil according to one embodiment of the present invention, the content of component (B) is 400 parts by mass or less, preferably 1 to 350 parts by mass, more preferably 2 to 300 parts by mass, even more preferably 3 to 250 parts by mass, and still more preferably 5 to 200 parts by mass, relative to 100 parts by mass of the total amount of components other than water in the water-soluble metalworking oil. When an emulsion-type oil classified as Type A1 according to JIS K2241:2017 is used, the content of component (B) may be 150 parts by mass or less, 100 parts by mass or less, 70 parts by mass or less, 50 parts by mass or less, 40 parts by mass or less, 30 parts by mass or less, 20 parts by mass or less, or 15 parts by mass or less, relative to 100 parts by mass of the total amount of components other than water in the water-soluble metalworking oil, and the lower limit is as described above. Furthermore, when a soluble oil classified as Type A2 as specified in JIS K2241:2017 is used, the content of component (B) may be 10 parts by mass or more, 30 parts by mass or more, 50 parts by mass or more, 60 parts by mass or more, 70 parts by mass or more, 80 parts by mass or more, 90 parts by mass or more, or 100 parts by mass or more, relative to 100 parts by mass of the total amount of components other than water in the water-soluble metalworking oil, and the upper limit is as described above.

[0039] In the water-soluble metalworking oil according to one embodiment of the present invention, the content of component (B) is preferably 1 to 99 mass%, more preferably 2 to 90 mass%, even more preferably 3 to 85 mass%, and still more preferably 5 to 80 mass%, based on the total amount (100 mass%) of the water-soluble metalworking oil. When the water-soluble metalworking oil is an emulsion-type oil classified as Type A1 as specified in JIS K2241:2017, the content of component (B) may be 70% by mass or less, 60% by mass or less, 50% by mass or less, 40% by mass or less, 30% by mass or less, 25% by mass or less, 20% by mass or less, or 15% by mass or less based on the total amount (100% by mass) of the water-soluble metalworking oil, and the lower limit is as described above. Furthermore, when a soluble oil classified as Type A2 as specified in JIS K2241:2017 is used, the content of component (B) may be 10% by mass or more, 15% by mass or more, 20% by mass or more, 25 parts by mass or more, 30% by mass or more, 35% by mass or more, 40% by mass or more, 45 parts by mass or more, or 50% by mass or more based on the total amount (100% by mass) of the water-soluble metalworking oil, and the upper limit is as described above.

[0040] <Component (C): Amine compound> The water-soluble metalworking fluid of one embodiment of the present invention preferably further contains an amine compound (C). When the water-soluble metalworking fluid containing component (C) is mixed with dilution water to prepare a metalworking fluid, it can have a good emulsified state and can provide a metalworking fluid with improved antibacterial properties, rust prevention properties, workability, etc. The component (C) may be used alone or in combination of two or more types.

[0041] From the same viewpoint as above, in the water-soluble metalworking oil of one embodiment of the present invention, the content of component (C) is, based on the total amount (100 mass%) of the water-soluble metalworking oil excluding water, preferably 3 to 70 mass%, more preferably 5 to 60 mass%, even more preferably 7 to 50 mass%, still more preferably 10 to 45 mass%, and particularly preferably 12 to 40 mass%, and may further be 15 mass% or more, 17 mass% or more, 20 mass% or more, 22 mass% or more, or 24 mass% or more, and may be 37 mass% or less, 35 mass% or less, 33 mass% or less, 31 mass% or less, 27 mass% or less, or 25 mass% or less.

[0042] From the same viewpoint as above, in the water-soluble metalworking oil of one embodiment of the present invention, the content of component (C) is, based on the total amount (100 mass%) of the water-soluble metalworking oil, preferably 2 to 40 mass%, more preferably 4 to 35 mass%, even more preferably 6 to 30 mass%, still more preferably 8 to 25 mass%, and particularly preferably 10 to 20 mass%, and may further be 11 mass% or more, or 12 mass% or more, or may be 18 mass% or less, or 16 mass% or less.

[0043] Furthermore, in the water-soluble metalworking oil according to one embodiment of the present invention, the content ratio of component (C) to component (A1) [(C) / (A1)], expressed as a mass ratio, is preferably 0.01 to 30, more preferably 0.05 to 25, even more preferably 0.10 to 20, still more preferably 0.20 to 15, and particularly preferably 0.25 to 9.0, and may be 0.28 or more, 0.30 or more, 0.40 or more, 0.50 or more, 0.60 or more, 0.70 or more, 0.80 or more, 0.90 or more, 1.00 or more, 1.20 or more, 1.40 or more, or 1.60 or more, or may be 8.0 or less, 7.0 or less, 6.0 or less, 5.0 or less, 4.5 or less, 4.0 or less, 3.5 or less, 3.0 or less, 2.9 or less, 2.8 or less, 2.7 or less, 2.6 or less, 2.5 or less, or 2.4 or less.

[0044] Component (C) used in one embodiment of the present invention may be any of a monoamine having one amino nitrogen atom in one molecule, a diamine having two amino nitrogen atoms in one molecule, and a polyamine having three or more amino nitrogen atoms in one molecule. However, from the viewpoint of obtaining a water-soluble metalworking oil that can be used as a metalworking fluid with improved antibacterial properties, rust prevention, workability, etc., it is preferable that component (C) used in one aspect of the present invention contains a monoamine. The content of the monoamine is preferably 50 to 100 mass%, more preferably 60 to 100 mass%, more preferably 70 to 100 mass%, more preferably 75 to 100 mass%, even more preferably 80 to 100 mass%, even more preferably 85 to 100 mass%, still more preferably 90 to 100 mass%, still more preferably 95 to 100 mass%, and particularly preferably 98 to 100 mass%, based on the total amount (100 mass%) of component (C) contained in the water-soluble metalworking oil.

[0045] The monoamines used as component (C) in one embodiment of the present invention are classified into primary monoamines represented by the following formula (i), secondary monoamines represented by the following formula (ii), and tertiary monoamines represented by the following formula (iii), depending on the number of substituents R: From the viewpoint of obtaining a water-soluble metalworking fluid that, when mixed with dilution water to prepare a metalworking fluid, has a good emulsified state and can provide a metalworking fluid with improved antibacterial properties, rust prevention properties, workability, and the like, component (C) used in one aspect of the present invention preferably contains at least a tertiary monoamine, more preferably contains at least one of a primary monoamine and a secondary monoamine and a tertiary monoamine, and even more preferably contains at least a secondary monoamine and a tertiary monoamine. [ka]

[0046] In the above formula, each R independently represents a substituent. Multiple Rs may be the same or different. Examples of the substituent include an alkyl group, an alkyl group having a hydroxyl group, an alkenyl group, a cycloalkyl group, a phenyl group, and a benzyl group.

[0047] Examples of the alkyl group that can be selected as the substituent R include a methyl group, an ethyl group, a propyl group (n-propyl group, i-propyl group), a butyl group (n-butyl group, i-butyl group, s-butyl group, t-butyl group), a pentyl group (n-pentyl group, i-pentyl group, neopentyl group), a hexyl group, a heptyl group, an octyl group, a 2-ethylhexyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, and an octadecyl group. The alkyl group may be a straight-chain alkyl group or a branched-chain alkyl group. The alkyl group preferably has 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, even more preferably 1 to 10 carbon atoms, still more preferably 1 to 6 carbon atoms, and particularly preferably 1 to 4 carbon atoms.

[0048] The alkyl group having a hydroxyl group that can be selected as the substituent R includes the above alkyl groups in which at least one hydrogen atom has been substituted with a hydroxyl group. The alkyl group constituting the group may be a straight-chain alkyl group or a branched-chain alkyl group. The alkyl group having a hydroxyl group preferably has 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, even more preferably 1 to 10 carbon atoms, still more preferably 1 to 6 carbon atoms, and particularly preferably 2 to 4 carbon atoms.

[0049] Examples of the alkenyl group that can be selected as the substituent R include ethenyl (vinyl), propenyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, dodecenyl, tridecenyl, tetradecenyl, pentadecenyl, hexadecenyl, and octadecenyl groups. The alkenyl group may be a straight-chain alkenyl group or a branched-chain alkenyl group. The alkenyl group preferably has 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, even more preferably 1 to 10 carbon atoms, still more preferably 1 to 6 carbon atoms, and particularly preferably 1 to 3 carbon atoms.

[0050] Examples of the cycloalkyl group that can be selected as the substituent R include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, and an adamantyl group.

[0051] Component (C) used in one aspect of the present invention preferably contains an alkanolamine having at least one alkyl group having a hydroxyl group, from the viewpoint of providing a water-soluble metalworking fluid that, when mixed with dilution water to prepare a metalworking fluid, has a good emulsified state and can provide a metalworking fluid with improved antibacterial properties, rust prevention properties, workability, etc. Examples of alkanolamines include primary alkanolamines in which R in the formula (i) is an alkyl group having a hydroxyl group, secondary alkanolamines in which at least one R in the formula (ii) is an alkyl group having a hydroxyl group, and tertiary alkanolamines in which at least one R in the formula (iii) is an alkyl group having a hydroxyl group.

[0052] Examples of primary alkanolamines include ethanolamine, propanolamine, butanolamine, and 2-amino-2-methyl-1-propanol.

[0053] Examples of secondary alkanolamines include monoethanolamines such as N-methylethanolamine, N-ethylethanolamine, N-propylethanolamine, N-butylethanolamine, N-octylethanolamine, N-stearylethanolamine, N-oleylethanolamine, N-cyclohexylethanolamine, N-phenylethanolamine, and N-benzylethanolamine; monopropanolamines such as N-methylpropanolamine, N-ethylpropanolamine, N-propylpropanolamine, N-butylpropanolamine, N-octylpropanolamine, N-stearylpropanolamine, N-oleylpropanolamine, N-cyclohexylpropanolamine, N-phenylpropanolamine, and N-benzylpropanolamine; diethanolamine, dipropanolamine, and the like.

[0054] Examples of tertiary alkanolamines include monoethanolamines such as N-dimethylethanolamine, N-diethylethanolamine, N-dipropylethanolamine, N-dibutylethanolamine, N-dioctylethanolamine, N-distearylethanolamine, N-dioleylethanolamine, N-dicyclohexylethanolamine, N-diphenylethanolamine, and N-dibenzylethanolamine; monopropanolamines such as N-dimethylpropanolamine, N-diethylpropanolamine, N-dipropylpropanolamine, N-dibutylpropanolamine, N-dioctylpropanolamine, N-distearylpropanolamine, N-dioleylpropanolamine, N-dicyclohexylpropanolamine, N-diphenylpropanolamine, and N-dibenzylpropanolamine; and N-methyldiethanol Examples of suitable amines include diethanolamines such as N-ethyldiethanolamine, N-propyldiethanolamine, N-butyldiethanolamine, N-octyldiethanolamine, N-stearyldiethanolamine, N-oleyldiethanolamine, N-cyclohexyldiethanolamine, N-phenyldiethanolamine, and N-benzyldiethanolamine; dipropanolamines such as N-methyldipropanolamine, N-ethyldipropanolamine, N-propyldipropanolamine, N-butyldipropanolamine, N-octyldipropanolamine, N-stearyldipropanolamine, N-oleyldipropanolamine, N-cyclohexyldipropanolamine, N-phenyldipropanolamine, and N-benzyldipropanolamine; and triethanolamine and tripropanolamine (e.g., triisopropanolamine).

[0055] Among these, from the viewpoint of obtaining a water-soluble metalworking oil that, when mixed with dilution water to form a metalworking fluid, has a good emulsified state and can become a metalworking fluid with improved antibacterial properties, rust prevention, workability, etc., component (C) used in one embodiment of the present invention preferably contains at least a tertiary alkanolamine, more preferably contains at least one of a primary alkanolamine and a secondary alkanolamine and a tertiary alkanolamine, and even more preferably contains at least a secondary alkanolamine and a tertiary alkanolamine.

[0056] The alkanolamine content is, based on the total amount (100% by mass) of component (C) contained in the water-soluble metalworking oil, preferably 5% by mass or more, more preferably 10% by mass or more, more preferably 20% by mass or more, even more preferably 30% by mass or more, still more preferably 35% by mass or more, and particularly preferably 40% by mass or more, and may further be 45% by mass or more, 50% by mass or more, or 55% by mass or more, or may be 100% by mass or less, 95% by mass or less, 90% by mass or less, 85% by mass or less, 80% by mass or less, 75% by mass or less, 70% by mass or less, or 65% by mass or less.

[0057] The component (C) used in one embodiment of the present invention preferably contains an alicyclic amine. Examples of the alicyclic amine include a primary alicyclic amine in which R in the formula (i) is a cycloalkyl group, a secondary alicyclic amine in which at least one R in the formula (ii) is a cycloalkyl group, and a tertiary alicyclic amine in which at least one R in the formula (iii) is a cycloalkyl group.

[0058] Examples of primary alicyclic amines include N-cyclohexylamine. Examples of secondary alicyclic amines include monocyclohexylamines such as N-methylcyclohexylamine, N-ethylcyclohexylamine, N-propylcyclohexylamine, and N-oleylcyclohexylamine; monocyclohexylalkanolamines such as N-cyclohexylethanolamine and N-cyclohexylpropanolamine; and N-dicyclohexylamine. Examples of tertiary alicyclic amines include dialkylmonocyclohexylamines such as N-dimethylcyclohexylamine, N-diethylcyclohexylamine, N-dipropylcyclohexylamine, N-dioleylcyclohexylamine, and N-dicyclohexylamine; monocyclohexyldialkanolamines such as N-cyclohexyldiethanolamine and N-cyclohexyldipropanolamine; monoalkyldicyclohexylamines such as N-methyldicyclohexylamine, N-ethyldicyclohexylamine, N-propyldicyclohexylamine, and N-oleyldicyclohexylamine; dicyclohexylalkanolamines such as N-dicyclohexylethanolamine and N-dicyclohexylpropanolamine; and tricyclohexylamine.

[0059] When an emulsion-type oil agent classified as Type A1 according to JIS K2241:2017 is used, component (C) preferably contains one or more selected from dialkylmonocyclohexylamines and monoalkyldicyclohexylamines, and more preferably contains monoalkyldicyclohexylamine. Furthermore, when a soluble oil classified as type A2 as specified in JIS K2241:2017 is used, component (C) preferably contains one or more selected from monocyclohexyldialkanolamines and dicyclohexylalkanolamines, and more preferably contains monocyclohexyldialkanolamine.

[0060] The content of the alicyclic amine is, based on the total amount (100% by mass) of component (C) contained in the water-soluble metalworking oil, preferably 10% by mass or more, more preferably 20% by mass or more, even more preferably 25% by mass or more, still more preferably 30% by mass or more, and particularly preferably 35% by mass or more, and may further be 37% by mass or more or 40% by mass or more, or may be 100% by mass or less, 95% by mass or less, 90% by mass or less, 85% by mass or less, 80% by mass or less, 75% by mass or less, 70% by mass or less, 65% by mass or less, 60% by mass or less, 55% by mass or less, or 50% by mass or less.

[0061] The water-soluble metalworking oil agent of one embodiment of the present invention may contain, as component (C), an amine other than alkanolamines and alicyclic amines (including diamines and polyamines). The content of the other amines may be 0 to 50 mass%, 0 to 40 mass%, 0 to 30 mass%, 0 to 20 mass%, 0 to 10 mass%, 0 to 5.0 mass%, 0 to 2.0 mass%, 0 to 1.0 mass%, 0 to 0.10 mass%, 0 to 0.01 mass%, 0 to 0.001 mass%, 0 to 0.0001 mass%, or 0 to 0.00001 mass% based on the total amount (100 mass%) of component (C) contained in the water-soluble metalworking oil.

[0062] <Component (D): Fatty acids> The water-soluble metalworking oil according to one embodiment of the present invention preferably further contains a fatty acid (D). By including component (D), it is possible to obtain a water-soluble metalworking fluid that can serve as a metalworking fluid with improved emulsion stability, rust prevention properties, workability, and the like. In the water-soluble metalworking oil agent according to one embodiment of the present invention, the component (D) may be used alone or in combination of two or more types.

[0063] From the same viewpoint as above, in the water-soluble metalworking oil of one embodiment of the present invention, the content of component (D) is, based on the total amount (100 mass%) of the water-soluble metalworking oil excluding water, preferably 5 to 70 mass%, more preferably 7 to 60 mass%, even more preferably 10 to 50 mass%, still more preferably 13 to 45 mass%, and particularly preferably 16 to 40 mass%, and may further be 18 mass% or more, 20 mass% or more, 22 mass% or more, or 25 mass% or more, and may be 38 mass% or less, 35 mass% or less, or 32 mass% or less.

[0064] From the same viewpoint as above, in the water-soluble metalworking oil of one embodiment of the present invention, the content of component (D) is, based on the total amount (100 mass%) of the water-soluble metalworking oil, preferably 2 to 60 mass%, more preferably 3 to 50 mass%, even more preferably 5 to 40 mass%, still more preferably 7 to 30 mass%, and particularly preferably 9 to 25 mass%, and may further be 10 mass% or more, 12 mass% or more, or 14 mass% or more, or may be 22 mass% or less, 20 mass% or less, or 18 mass% or less.

[0065] Furthermore, in the water-soluble metalworking oil according to one embodiment of the present invention, the content ratio of component (D) to component (A1) [(D) / (A1)], expressed as a mass ratio, is preferably 0.01 to 30, more preferably 0.05 to 25, more preferably 0.10 to 20, even more preferably 0.20 to 15, still more preferably 0.25 to 12.0, and particularly preferably 0.30 to 8.0, and may be 0.32 or more, 0.35 or more, 0.50 or more, 0.70 or more, 0.90 or more, 1.00 or more, 1.20 or more, 1.40 or more, or 1.50 or more, and may be 7.0 or less, 6.0 or less, 5.0 or less, 4.5 or less, 4.0 or less, 3.8 or less, 3.6 or less, 3.4 or less, 3.2 or less, 3.0 or less, 2.8 or less, 2.6 or less, or 2.4 or less.

[0066] In one aspect of the water-soluble metalworking oil of the present invention, from the viewpoint of improving the stability of the oil concentrate and providing a water-soluble metalworking oil that can become a metalworking fluid with further improved workability, the content ratio of component (C) to component (D) [(C) / (D)] is, in mass ratio, preferably 0.01 to 5.0, more preferably 0.05 to 4.0, more preferably 0.1 to 3.0, even more preferably 0.2 to 2.5, still more preferably 0.3 to 2.0, and particularly preferably 0.5 to 1.5, and may further be 0.6 or more, 0.65 or more, 0.7 or more, 0.75 or more, or 0.8 or more, or may be 1.4 or less, 1.3 or less, 1.2 or less, or 1.15 or less.

[0067] Examples of the component (D) used in one embodiment of the present invention include fatty acids, hydroxy fatty acids, aliphatic dicarboxylic acids, dimer acids of fatty acids, and polymerized fatty acids of hydroxy unsaturated fatty acids.

[0068] Examples of the fatty acids include saturated aliphatic monocarboxylic acids such as octanoic acid, 2-ethylhexanoic acid, decanoic acid, neodecanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, pentadecanoic acid, heptadecanoic acid, nonadecanoic acid, myristic acid, palmitic acid, stearic acid, arachic acid, behenic acid, and isostearic acid; and unsaturated aliphatic monocarboxylic acids such as octenoic acid, nonenoic acid, decenoic acid, undecenoic acid, oleic acid, elaidic acid, erucic acid, nervonic acid, linoleic acid, γ-linolenic acid, arachidonic acid, α-linolenic acid, stearidonic acid, eicosapentaenoic acid, and docosahexaenoic acid. Furthermore, mixtures of unsaturated fatty acids such as tall oil fatty acids, soybean oil fatty acids, palm oil fatty acids, linseed oil fatty acids, rice bran oil fatty acids, cottonseed oil fatty acids, etc. may also be used. The fatty acid preferably has 8 to 30 carbon atoms, more preferably 10 to 25 carbon atoms, and even more preferably 10 to 20 carbon atoms.

[0069] Examples of the hydroxy fatty acids include hydroxylauric acid, hydroxymyristic acid, hydroxypalmitic acid, hydroxystearic acid, hydroxyarachidic acid, hydroxybehenic acid, and hydroxyoctadecenoic acid. The hydroxy fatty acid preferably has 8 to 30 carbon atoms, more preferably 10 to 25 carbon atoms, and even more preferably 10 to 20 carbon atoms.

[0070] Examples of the aliphatic dicarboxylic acid include saturated aliphatic dicarboxylic acids such as sebacic acid, dodecanedioic acid, dodecyl succinic acid, lauryl succinic acid, stearyl succinic acid, and isostearyl succinic acid. The aliphatic dicarboxylic acid preferably has 8 to 30 carbon atoms, more preferably 10 to 25 carbon atoms, and even more preferably 10 to 20 carbon atoms.

[0071] Examples of the hydroxy unsaturated fatty acid constituting the polymerized fatty acid of the hydroxy unsaturated fatty acid include ricinoleic acid (12-hydroxyoctadec-9-enoic acid), etc. Also, a fatty acid mixture containing ricinoleic acid, such as castor oil, may be used. Examples of the polymerized fatty acid of the hydroxy unsaturated fatty acid include condensed fatty acids that are dehydration polycondensates of hydroxy unsaturated fatty acids (for example, castor oil polymerized fatty acid that is a dehydration condensate of a fatty acid mixture containing ricinoleic acid as the main component), and condensed fatty acids obtained by dehydration condensation of an alcoholic hydroxyl group of a condensed fatty acid that is a dehydration polycondensate of hydroxy unsaturated fatty acids with a monocarboxylic acid.

[0072] Component (D) used in one embodiment of the present invention preferably contains one or more (preferably two or more, more preferably three or more) selected from unsaturated aliphatic monocarboxylic acids, saturated aliphatic dicarboxylic acids, and polymerized fatty acids of hydroxyunsaturated fatty acids, and more preferably contains at least all of unsaturated aliphatic monocarboxylic acids, saturated aliphatic dicarboxylic acids, and polymerized fatty acids of hydroxyunsaturated fatty acids.

[0073] The acid value of component (D) is usually 0 mgKOH / g or more, preferably 10 to 100 mgKOH / g, more preferably 20 to 90 mgKOH / g, and even more preferably 30 to 80 mgKOH / g, from the viewpoint of obtaining a water-soluble metalworking oil that can serve as a metalworking fluid with improved workability. The hydroxyl value of component (D) is preferably 0 to 80 mgKOH / g, more preferably 0 to 60 mgKOH / g, and even more preferably 0 to 40 mgKOH / g. From the above viewpoints, the ratio of the acid value to the hydroxyl value of component (D) [acid value / hydroxyl value] is preferably 1.5 to 15, more preferably 2.0 to 10, and even more preferably 2.5 to 9.5. The saponification value of component (D) is preferably 180 to 220 mgKOH / g, more preferably 190 to 210 mgKOH / g, and even more preferably 195 to 205 mgKOH / g. In this specification, the acid value means a value measured in accordance with JIS K2501:2003 (indicator photometric titration method), the hydroxyl value means a value measured in accordance with JIS K0070:1992, and the saponification value means a value measured in accordance with JIS K2503:1996.

[0074] <Nonionic surfactant (E)> The water-soluble metalworking fluid of one embodiment of the present invention preferably further contains a nonionic surfactant (E). By containing component (E), the water-soluble metalworking fluid can be made into a metalworking fluid with improved emulsion stability and workability. In the water-soluble metalworking oil agent according to one embodiment of the present invention, the component (E) may be used alone or in combination of two or more types.

[0075] From the above viewpoints, in the water-soluble metalworking oil of one embodiment of the present invention, the content of component (E) is preferably 0.5 to 35.0 mass%, more preferably 1.0 to 30.0 mass%, even more preferably 1.2 to 25.0 mass%, still more preferably 1.5 to 20.0 mass%, and particularly preferably 1.7 to 16.0 mass%, based on the total amount (100 mass%) of the water-soluble metalworking oil excluding water. When an emulsion-type oil classified as Type A1 as specified in JIS K2241:2017 is used, the content of component (E) may be 15.0 mass% or less, 12.0 mass% or less, 10.0 mass% or less, 8.0 mass% or less, 6.0 mass% or less, 5.0 mass% or less, 4.0 mass% or less, or 3.5 mass% or less, based on the total amount (100 mass%) of the water-soluble metalworking oil excluding water, and the lower limit is as described above. When a soluble oil classified as Type A2 according to JIS K2241:2017 is used, the content of component (E) may be 2.0 mass% or more, 3.0 mass% or more, 4.0 mass% or more, 5.0 mass% or more, 6.0 mass% or more, 7.0 mass% or more, 8.0 mass% or more, 9.0 mass% or more, or 10.0 mass% or more based on the total amount (100 mass%) of the water-soluble metalworking oil excluding water, and the upper limit is as described above.

[0076] From the above viewpoints, in the water-soluble metalworking oil of one embodiment of the present invention, the content of component (E) is preferably 0.1 to 15.0 mass%, more preferably 0.2 to 12.0 mass%, even more preferably 0.3 to 10.0 mass%, still more preferably 0.5 to 8.0 mass%, and particularly preferably 0.7 to 6.0 mass%, based on the total amount (100 mass%) of the water-soluble metalworking oil. When an emulsion-type oil classified as Type A1 according to JIS K2241:2017 is used, the content of component (E) may be 5.0 mass% or less, 4.5 mass% or less, 4.0 mass% or less, 3.5 mass% or less, 3.0 mass% or less, or 2.5 mass% or less based on the total amount (100 mass%) of the water-soluble metalworking oil, with the lower limit being as described above. When a soluble oil classified as Type A2 according to JIS K2241:2017 is used, the content of component (E) may be 1.0 mass% or more, 1.2 mass% or more, 1.5 mass% or more, 2.0 mass% or more, 2.5 mass% or more, 3.0 mass% or more, 3.5 mass% or more, or 4.0 mass% or more based on the total amount (100 mass%) of the water-soluble metalworking oil, with the upper limit as described above.

[0077] From the viewpoint of obtaining a water-soluble metalworking fluid that can be used as a metalworking fluid with improved emulsion stability and processability, the HLB of component (E) used in one embodiment of the present invention is preferably 6.0 or more, more preferably 7.0 or more, even more preferably 8.0 or more, still more preferably 9.0 or more, and particularly preferably 10.0 or more, and is 18.0 or less, preferably 17.0 or less, more preferably 16.0 or less, even more preferably 15.0 or less, and still more preferably 14.5 or less. In this specification, HLB refers to a value calculated by the Griffin method.

[0078] Examples of component (E) used in one embodiment of the present invention include alkylene glycols, polyoxyalkylene alkyl ethers, polyoxyalkylene aryl ethers, polyoxyalkylene alkylamines (cocoamine alkylene oxide adducts), alkylphenol alkylene oxide adducts, higher alcohol alkylene oxide adducts, polyoxyalkylene fatty acid esters, fatty acid esters of glycerin and pentaerythritol, fatty acid esters of sucrose, fatty acid esters of polyoxyalkylene adducts of polyhydric alcohols, alkyl polyglycosides, and fatty acid alkanolamides.

[0079] Among these, from the viewpoint of obtaining a water-soluble metalworking oil that can become a metalworking fluid with improved emulsion stability and processability, it is preferable that component (E) used in one aspect of the present invention contains one or more selected from polyoxyalkylene alkyl ethers and polyoxyalkylene alkyl amines. The total content of polyoxyalkylene alkyl ether and polyoxyalkylene alkylamine is preferably 50 to 100 mass%, more preferably 70 to 100 mass%, even more preferably 80 to 100 mass%, still more preferably 90 to 100 mass%, and particularly preferably 95 to 100 mass%, based on the total amount (100 mass%) of component (E) contained in the water-soluble metalworking oil.

[0080] <Sulfur-based extreme pressure agent> Since the water-soluble metalworking oil of the present invention contains an oil-soluble PAG (A1) as the base oil (A), it is possible to prepare a metalworking fluid with excellent workability without containing a sulfur-based extreme pressure agent, which is a factor in causing corrosion of copper-containing members. Therefore, from the viewpoint of obtaining a water-soluble metalworking oil that can be used as a metalworking fluid with a high corrosion-inhibiting effect on copper-containing members, it is preferable that the water-soluble metalworking oil of one embodiment of the present invention is substantially free of a sulfur-based extreme pressure agent. Examples of sulfur-based extreme pressure agents include sulfurized olefins, sulfurized lard, alkyl polysulfides, sulfurized fatty acids, and the like.

[0081] Furthermore, in this specification, the phrase "substantially free of sulfur-based extreme pressure agents" stipulates that sulfur-based extreme pressure agents may be contained for a specific purpose, but does not stipulate that sulfur-based extreme pressure agents may be unintentionally mixed in as impurities of other components. However, even taking into consideration such unintentional mixing of sulfur-based extreme pressure agents, from the viewpoint of providing a water-soluble metalworking fluid that can be a metalworking fluid highly effective in inhibiting corrosion of copper-containing members, it is preferable that the content of sulfur-based extreme pressure agents be as small as possible. The specific content of the sulfur-based extreme pressure agent is preferably less than 10 parts by mass, more preferably less than 1 part by mass, even more preferably less than 0.1 part by mass, still more preferably less than 0.01 part by mass, and particularly preferably less than 0.001 part by mass, relative to 100 parts by mass of the total amount of component (A1) contained in the water-soluble metalworking oil.

[0082] <Other additives> The water-soluble metalworking oil agent according to one embodiment of the present invention may further contain various additives other than the above components (A) to (E) as necessary, provided that the effects of the present invention are not impaired. Examples of such other various additives include anionic surfactants, cationic surfactants, petroleum sulfonates, non-sulfur-based extreme pressure agents, metal deactivators, emulsifying aids, antibacterial agents, antifoaming agents, antioxidants, oiliness agents, and the like. These various additives may be used alone or in combination of two or more.

[0083] In the water-soluble metalworking oil according to one embodiment of the present invention, the content of each of these various additives is appropriately set depending on the type and function of each component, but is preferably 0.001 to 50 mass%, more preferably 0.01 to 40 mass%, even more preferably 0.07 to 30 mass%, and still more preferably 0.1 to 20 mass%, based on the total amount (100 mass%) of the water-soluble metalworking oil excluding water.

[0084] In the water-soluble metalworking oil according to one embodiment of the present invention, the content of each of these various additives is appropriately set depending on the type and function of each component, but is preferably 0.001 to 25 mass%, more preferably 0.01 to 20 mass%, even more preferably 0.03 to 15 mass%, and still more preferably 0.05 to 10 mass%, based on the total amount (100 mass%) of the water-soluble metalworking oil.

[0085] Examples of anionic surfactants include polyoxyethylene alkyl ether carboxylic acids, polyoxyethylene alkyl ether phosphates, alkylbenzene sulfonic acids, α-olefin sulfonic acids, and salts thereof. The acid value of the anionic surfactant is preferably 20 to 250 mgKOH / g, more preferably 30 to 200 mgKOH / g, even more preferably 40 to 190 mgKOH / g, and even more preferably 50 to 180 mgKOH / g. Examples of cationic surfactants include alkyltrimethylammonium salts, dialkyldimethylammonium salts, and alkyldimethylbenzylammonium salts.

[0086] Examples of petroleum sulfonates include calcium sulfonate, sodium sulfonate, and magnesium sulfonate.

[0087] Examples of extreme pressure agents other than sulfur-based agents include chlorine-based extreme pressure agents such as chlorinated paraffin, chlorinated fatty acid, and chlorinated fatty oil; phosphate esters, phosphites, thiophosphate esters, and salts thereof, phosphine-based agents, and phosphorus-based extreme pressure agents such as tricresyl phosphate; and the like.

[0088] Examples of metal deactivators include benzotriazoles, imidazolines, pyrimidine derivatives, and thiadiazoles.

[0089] Examples of the emulsifying aid include unsaturated fatty acid esters such as methyl oleate, ethyl oleate, and propyl oleate; aromatic alcohols such as 2-phenoxyethanol and 2-phenylethyl alcohol; and the like.

[0090] Examples of antibacterial agents include isothiazolinone compounds, triazine compounds, alkylbenzimidazole compounds, and metal pyrithione salts.

[0091] Examples of the antifoaming agent include silicone-based antifoaming agents, fluorosilicone-based antifoaming agents, polyacrylates, and the like.

[0092] Examples of antioxidants include amine-based antioxidants such as alkylated diphenylamine, phenylnaphthylamine, and alkylated phenylnaphthylamine; and phenol-based antioxidants such as 2,6-di-t-butylphenol, 4,4'-methylenebis(2,6-di-t-butylphenol), isooctyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, and n-octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate.

[0093] Examples of oily agents include alcohols such as lauryl alcohol, myristyl alcohol, palmityl alcohol, stearyl alcohol, and oleyl alcohol.

[0094] <Method of manufacturing water-soluble metalworking oil> The method for producing a water-soluble metalworking oil according to one embodiment of the present invention is not particularly limited, and is preferably a method comprising a step of blending the above-mentioned component (A), and, if necessary, components (B) to (E) and various other additives. The order of blending the components can be appropriately determined.

[0095] [Properties of water-soluble metalworking oils] The acid value of the water-soluble metalworking oil of one embodiment of the present invention is preferably 10 to 70 mgKOH / g, more preferably 15 to 60 mgKOH / g, even more preferably 20 to 50 mgKOH / g, and still more preferably 25 to 40 mgKOH / g. The base number of the water-soluble metalworking oil of one embodiment of the present invention is preferably 10 to 100 mgKOH / g, more preferably 20 to 90 mgKOH / g, even more preferably 30 to 80 mgKOH / g, and still more preferably 40 to 70 mgKOH / g. In this specification, the base number refers to a value measured in accordance with JIS K2501:2003 (hydrochloric acid method).

[0096] The ratio of the base number to the acid number [base number / acid number] of the water-soluble metalworking oil agent of one embodiment of the present invention is preferably 1.0 to 4.0, more preferably 1.1 to 3.5, even more preferably 1.3 to 3.2, still more preferably 1.5 to 3.0, and particularly preferably 1.7 to 2.8. If the ratio is 1.0 or more, the water-soluble metalworking fluid has good putrefaction resistance, while if the ratio is 4.0 or less, the irritation to human skin can be reduced, which is preferable in terms of handling.

[0097] [Form of metalworking fluid] The metalworking fluid of the present invention is prepared by blending the metalworking oil according to one embodiment of the present invention as a stock solution with dilution water. The dilution water may be, for example, distilled water, ion-exchanged water, tap water, industrial water, or the like.

[0098] The amount of dilution water used in preparing a metalworking fluid is more than 400 parts by mass per 100 parts by mass of the total amount of the components other than water in the water-soluble metalworking oil, but it is preferable to adjust the amount appropriately to achieve the desired dilution concentration. The dilution concentration of the metalworking fluid according to one embodiment of the present invention is preferably 1 to 50% by volume, more preferably 3 to 40% by volume, and even more preferably 5 to 20% by volume. In this specification, the above-mentioned "dilution concentration of the metalworking fluid" means a value calculated from the following formula. "Dilution concentration of metalworking fluid (volume %)" = [Volume of metalworking fluid before dilution] / [[Volume of metalworking fluid before dilution] + [Volume of dilution water]] x 100

[0099] [Uses of metalworking fluids and metalworking methods] A metalworking fluid according to a preferred embodiment of the present invention has superior workability compared to conventional metalworking fluids and can be suitably used for metalworking. Furthermore, the metalworking fluid according to a preferred embodiment of the present invention can exhibit excellent workability without containing a sulfur-based extreme pressure agent. Therefore, corrosion of copper-containing components constituting a processing machine, which is caused by a sulfur-based extreme pressure agent, can be effectively suppressed.

[0100] The workpiece to be machined using the metalworking fluid of one embodiment of the present invention is not particularly limited, but is particularly suitable for workpieces made of metals selected from the group consisting of iron, titanium, aluminum, titanium alloys, alloy steels, nickel-based alloys, niobium alloys, tantalum alloys, molybdenum alloys, tungsten alloys, stainless steels, aluminum alloys, and high-manganese steels. Among these, the metalworking fluid is particularly suitable for workpieces having a component containing at least iron or aluminum.

[0101] Therefore, the present invention can also provide the following [1] and [2]. [1] A method of using the metalworking fluid according to one embodiment of the present invention to process a workpiece made of metal. [2] A metalworking method in which the metalworking fluid according to one aspect of the present invention is applied to workpieces made of metal.

[0102] The workpieces described in [1] and [2] above are as described above, but workpieces having a member containing at least iron or aluminum are preferred. Furthermore, according to the methods described in [1] and [2] above, corrosion of copper-containing members constituting a processing machine used to process the workpiece can be suppressed.

[0103] In the above [1] and [2], examples of the processing of the workpiece include cutting, grinding, punching, polishing, drawing, drawing, and rolling. In the method of use [1] above and the metalworking method [2] above, the metalworking fluid is prepared by blending the water-soluble metalworking oil of one embodiment of the present invention with dilution water, supplying the mixture to the workpiece, and bringing the mixture into contact with the workpiece. The metalworking fluid lubricates the workpiece and the tool. It is also used for removing chips, preventing rust on the workpiece, and cooling the tool and the workpiece. [Example]

[0104] Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples in any way. In the following examples, the methods for measuring and calculating the following physical properties are as follows. (1)Kinematic viscosity, viscosity index Measurements and calculations were made in accordance with JIS K2283:2000. (2) HLB Calculation was based on the Griffin method. (3) Acid value (indicator photometric titration method) Measurements were performed in accordance with JIS K2501:2003 (indicator photometric titration method). (4) Base number (hydrochloric acid method) Measurement was performed in accordance with JIS K2501:2003 (hydrochloric acid method).

[0105] Examples 1 to 8, Comparative Examples 1 to 4 Water-soluble metalworking fluids were prepared by adding and mixing the various components shown in Tables 2 and 3 in the amounts shown in Tables 2 and 3. Details of the components used in preparing the water-soluble metalworking fluids are as follows:

[0106] <Ingredient (A1)> Oil-soluble PAG (a-1): An oil-soluble polyalkylene glycol that meets the viscosity grade VG32 specified in ISO 3448. Oil-soluble PAG (a-2): An oil-soluble polyalkylene glycol that meets the viscosity grade VG46 specified in ISO 3448. Oil-soluble PAG (a-3): An oil-soluble polyalkylene glycol that meets the viscosity grade VG68 specified in ISO 3448. <Ingredient (A2)> Paraffinic mineral oil: 40℃ kinematic viscosity = 7.117mm 2 / s, paraffinic mineral oil with a viscosity index of 109. <Ingredient (B)> Water: Ion-exchanged water <Ingredient (C)> Amines (c-1): N-methylethanolamine, secondary monoamines Amine (c-2): N-cyclohexyldiethanolamine, tertiary monoamine Amines (c-3): N-methyldiethanolamine, tertiary monoamines Amines (C-4): Triisopropanolamine, tertiary monoamines Amine (c-5): N-methyldicyclohexylamine, tertiary monoamine <Ingredient (D)> Fatty acids (d-1): Neodecanoic acid Fatty acids (d-2): Tall oil fatty acids Fatty acids (d-3): dodecanedioic acid Fatty acids (d-4): Castor oil polymerized fatty acids (ricinoleic acid hexamer, acid value: 31.6 mg KOH / g, hydroxyl value: 9.4 mg KOH / g, acid value / hydroxyl value = 3.36) <Ingredient (E)> Nonionic surfactant (e-1): Cocoamine ethylene oxide 2 mole adduct, HLB=6.3 Nonionic surfactant (e-2): Polyoxyalkylene alkyl ether, HLB=12.7 <Sulfur-based extreme pressure agent> Dioctyl polysulfide <Other ingredients> Anionic surfactant: Polyoxyethylene oleyl ether carboxylic acid, acid value = 69.3 mg KOH / g. Metal deactivator: Benzotriazole Emulsifier: 2-phenoxyethanol Antibacterial agent: 1,2-benzisothiazolin-3-one Antifoaming agent: Silicone-based antifoaming agent

[0107] The acid value, base value, and base number / acid value ratio of the prepared water-soluble metalworking fluids were measured and calculated, and the water-soluble metalworking fluids were evaluated as follows. The results are shown in Tables 2 and 3. (1) Classification of oil types In accordance with the provisions of JIS K2241:2017, the products were classified as either Class A1 emulsion-type oils or Class A2 soluble-type oils. In Tables 2 and 3, products classified as Class A1 emulsion-type oils are indicated with "E," and products classified as Class A2 soluble-type oils are indicated with "S."

[0108] (2) Copper plate corrosion test Tests were conducted using a test method in accordance with JIS K2513 under conditions of an oil temperature of 50°C for 48 hours, and the degree of discoloration of the copper plate was observed. The degree of corrosion of the copper plate was evaluated based on "Table 1: Classification of corrosion according to the copper plate corrosion standard" of JIS K2513 shown in Table 1 below. In Tables 2 and 3, the results are listed as "discoloration numbers (subdivision symbols)," and the discoloration numbers are numbers from 1 to 4 that indicate the degree of corrosion of the copper plate, with larger numbers indicating more advanced corrosion.

[0109] [Table 1]

[0110] (3) Evaluation of workability A water-soluble metalworking fluid was diluted with ion-exchanged water to prepare a metalworking fluid with a dilution concentration of 5% by volume. Using the prepared metalworking fluid, pilot holes were drilled under the following conditions, and then a tapping torque test was conducted to measure the maximum tapping torque during drilling. The measurement was performed three times, and the average and maximum values ​​of the results are shown in Tables 2 and 3. The smaller the average value and the maximum value, the better the metalworking properties of the metalworking fluid used. <Pre-drilling conditions> Machine used: Tapping center MTV-T350 (Mectron Co., Ltd.) Drill: SG-ESS (Fujikoshi Corporation), drill diameter: 5.56 mm ·Cutting speed: 31m / min Rotation speed: 1798 min -1 Feed rate: 260mm / min Feed per revolution: 0.145mm / rev Depth: 15mm <Tapping torque test> Testing machine used: Megatap II (micro-electronische Gerate GmbH) Tap: Neurol Tap VP-NRT B M6 x 1 (OSG Corporation) ·Cutting speed: 10m / min Feed rate: 1.0mm / rev Depth: 12mm ·Number of processing: 3 · Workpiece material: SCM440 (JIS standard) (chrome molybdenum steel)

[0111] [Table 2]

[0112] [Table 3]

[0113] As can be seen from Tables 2 and 3, the metalworking fluids prepared by diluting the water-soluble metalworking fluids of Examples 1 to 8, both soluble and emulsion types, inhibited copper plate corrosion and had good workability. On the other hand, the metalworking fluids prepared by diluting the water-soluble metalworking fluids of Comparative Examples 1 to 4 were inferior in at least one of the copper plate corrosion inhibition effect and workability.

Claims

1. Contains a base oil (A) containing an oil-soluble polyalkylene glycol (A1), A water-soluble metalworking oil having a total content of water-soluble polyalkylene glycol and methoxypolyethylene glycol of less than 60 mass% based on the total amount excluding water.

2. 2. The water-soluble metalworking fluid according to claim 1, wherein the total content of the water-soluble polyalkylene glycol and the methoxypolyethylene glycol is less than 10 parts by mass per 100 parts by mass of the total amount of component (A1).

3. 3. The water-soluble metalworking oil according to claim 1, which is substantially free of a sulfur-based extreme pressure agent.

4. The water-soluble metalworking oil according to any one of claims 1 to 3, further comprising water (B).

5. 5. The water-soluble metalworking oil according to claim 1, wherein the content of component (A1) in component (A) is 10 to 100 mass% based on the total amount of component (A) contained in the water-soluble metalworking oil.

6. 6. The water-soluble metalworking oil according to claim 1, wherein the content of component (A1) is 0.01 mass% or more based on the total amount of the water-soluble metalworking oil excluding water.

7. The water-soluble metalworking oil according to any one of claims 1 to 6, further comprising an amine compound (C).

8. The water-soluble metalworking oil according to any one of claims 1 to 7, further comprising a fatty acid (D).

9. The water-soluble metalworking oil according to any one of claims 1 to 8, further comprising a nonionic surfactant (E).

10. The water-soluble metalworking oil according to any one of claims 1 to 9, which is an emulsion-type oil classified as Type A1 according to JIS K2241:2017.

11. The water-soluble metalworking oil according to any one of claims 1 to 9, which is a soluble oil classified as type A2 according to JIS K2241:2017.

12. Contains a base oil (A) containing an oil-soluble polyalkylene glycol (A1), A water-soluble metalworking fluid, in which the total content of the water-soluble polyalkylene glycol and the methoxypolyethylene glycol is less than 10 parts by mass per 100 parts by mass of the total amount of the component (A).

13. A metalworking fluid obtained by blending the water-soluble metalworking oil according to any one of claims 1 to 12 with dilution water.

14. A metalworking method, comprising applying the metalworking fluid according to claim 13 to work a workpiece made of metal.

15. The metal processing method according to claim 14, wherein the workpiece comprises a member containing at least iron or aluminum.

16. 16. The metal processing method according to claim 14, wherein corrosion of copper-containing members constituting a processing machine used to process the workpiece is suppressed.

Images