Water-soluble metalworking fluid

Abstract

Provided is a water-soluble metalworking fluid containing a base oil (A) including an oil-soluble polyalkylene glycol (A1), the total content of water-soluble polyalkylene glycols and methoxypolyethylene glycols being less than 60 mass% in terms of total weight, excluding water.

Description

[Technical Field]

[0001] The present invention relates to a water-soluble metalworking fluid, a metalworking solution obtained by diluting the water-soluble metalworking fluid with water, and a metalworking method for processing a workpiece made of metal by applying the metalworking solution. [Background technology]

[0002] In metalworking fields such as cutting and grinding, metalworking fluids are used to improve the machinability of the workpiece and to suppress wear of the processing tools. Metalworking fluids include oil-based metalworking fluids, which are primarily composed of oils such as mineral oil, synthetic oil, and animal / vegetable oils, and water-soluble metalworking fluids, which are formulated by adding surfactant compounds to the oils to make them water-soluble. In recent years, water-soluble metalworking fluids have come into use 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 comprising 60 to 90% by weight of a base oil selected from the group consisting of water-soluble polyalkylene glycol, methoxypolyethylene glycol, 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 [Overview of the project] [Problems that the invention aims to solve]

[0005] Under these circumstances, there is a need for novel water-soluble metalworking fluids, such as emulsion-type and soluble-type fluids, that have improved performance in various aspects to make them easier to apply to metalworking compared to conventional products. [Means for solving the problem]

[0006] The present invention provides a water-soluble metalworking fluid containing oil-soluble polyalkylene glycol as a base oil, with the content of water-soluble polyalkylene glycol and methoxypolyethylene glycol being below a predetermined amount. Specifically, the present invention provides, for example, the following embodiments [1] to

[16] . [1] Contains a base oil (A) containing 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 60% by mass on a total basis excluding water. [2] The water-soluble metalworking fluid according to [1] above, wherein 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 (A1). [3] A water-soluble metalworking fluid according to [1] or [2] above, which substantially does not contain a sulfur-based extreme pressure agent. [4] A water-soluble metalworking fluid according to any one of the above items [1] to [3], further containing water (B). [5] The water-soluble metalworking fluid according to any one of the above [1] to [4], wherein the content ratio of component (A1) in component (A) is 10 to 100% by mass on a basis of the total amount of component (A) contained in the water-soluble metalworking fluid. [6] The water-soluble metalworking fluid according to any one of the above items [1] to [5], wherein the content of component (A1) is 0.01% by mass or more on a total basis excluding water in the water-soluble metalworking fluid. [7] A water-soluble metalworking fluid according to any one of the above [1] to [6], further containing an amine compound (C). [8] A water-soluble metalworking fluid according to any one of the above items [1] to [7], further containing fatty acids (D). [9] A water-soluble metalworking fluid according to any one of the above [1] to [8], further containing a nonionic surfactant (E).

[10] A water-soluble metalworking fluid described in any one of the above items [1] to [9], which is an emulsion-type oil classified as type A1 as specified in JIS K2241:2017.

[11] A soluble type oil classified as type A2 as specified in JIS K2241:2017, a water-soluble metalworking oil as described in any one of the above items [1] to [9].

[12] Contains a base oil (A) containing 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 comprising a water-soluble metalworking fluid described in any one of the above items [1] to

[12] , and diluted with water.

[14] A metalworking method for processing a workpiece made of metal by applying the metalworking fluid described in

[13] above.

[15] The metalworking method according to

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

[16] The metalworking method according to

[14] or

[15] above, which suppresses corrosion of copper-containing components that constitute a processing machine used for processing the workpiece. [Effects of the Invention]

[0007] A water-soluble metalworking fluid according to one preferred embodiment of the present invention can be prepared as a metalworking fluid with excellent various properties such as workability by diluting it with diluted water. [Modes for carrying out the invention]

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

[0009] In this specification, the "metalworking oil agent" is the undiluted solution of the metalworking fluid before dilution with dilution water to form a metalworking fluid, and is in a suitable form during transportation and storage before use in metalworking. Also, the "metalworking fluid" is obtained by adding and diluting dilution water to the metalworking oil agent which is the undiluted solution, and is in a suitable form when used in metalworking. The "metalworking oil agent" and the "metalworking fluid" can be distinguished, for example, as follows, by the water content. · "Metalworking oil agent": The water content is 0 parts by mass or more and 400 parts by mass or less with respect to 100 parts by mass of the total amount of components other than water. · "Metalworking fluid": The water content is more than 400 parts by mass with respect to 100 parts by mass of the total amount of components other than water.

[0010] 〔Composition of water-soluble metalworking oil agent〕 The water-soluble metalworking oil agent of the present invention contains a base oil (A) containing an oil-soluble polyalkylene glycol (hereinafter also referred to as "oil-soluble PAG") (A1), and is an oil agent in which the total content of 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 has a solubility of 20 g or more in 100 g of water at 25°C and a total light transmittance of 90% or more for a solution at 25°C prepared by adding 20 g of the target substance to 100 g of water at 25°C. In the following description of this specification, the components described as "water-soluble" are components having the above characteristics.

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

[0012] Also, in the water-soluble metal working oil of one aspect of the present invention, the total content of 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 with respect to 100 parts by mass of the total amount of component (A1).

[0013] The water-soluble metal working oil of one aspect of the present invention described above may further contain water (B). By adjusting the content of water (B), it can be prepared into an emulsion-type oil agent classified as type A1 or a soluble-type oil agent classified as type A2 defined in JIS K2241:2017.

[0014] Also, the water-soluble metal working oil of one aspect of the present invention described above preferably contains one or more selected from amine compounds (C), fatty acids (D), and nonionic surfactants (E), more preferably contains at least components (C) and (D), and even more preferably contains all of components (C), (D), and (E). Note that the water-soluble metal working oil of one aspect of the present invention may contain other components other than components (A) to (E) as long as the effects of the present invention are not impaired.

[0015] In one embodiment of the present invention, the total content of components (A) and (B) is preferably 20% by mass or more, more preferably 30% by mass or more, even more preferably 40% by mass or more, even more preferably 45% by mass or more, and particularly preferably 50% by mass or more, based on the total amount (100% by mass) of the water-soluble metalworking fluid, 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 one embodiment of the present invention, the total content of components (A) to (D) is 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, even more preferably 70% by mass or more, and particularly preferably 80% by mass or more, based on the total amount (100% by mass) of the water-soluble metalworking fluid. It 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 one embodiment of the present invention, the total content of components (A) to (E) is 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, even more preferably 75% by mass or more, and particularly preferably 85% by mass or more, based on the total amount (100% by mass) of the water-soluble metalworking fluid, 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. The following describes the components contained in a water-soluble metalworking fluid according to one embodiment of the present invention.

[0018] <Ingredients (A): Base oil> The water-soluble metalworking fluid of the present invention contains a base oil (A) containing oil-soluble PAG(A1). The water-soluble metalworking fluid of the present invention contains oil-soluble PAG as a base oil, and therefore can improve the workability of a metalworking solution obtained by blending the water-soluble metalworking fluid with diluting water. Generally, to create a metalworking fluid with excellent workability (especially for workpieces containing iron), the water-soluble metalworking fluid concentrate typically contains a sulfur-based extreme pressure agent. However, sulfur-based extreme pressure agents can cause corrosion of copper-containing components that make up the processing machine used during metalworking of workpieces. On the other hand, the water-soluble metalworking fluid of the present invention, by containing component (A1), can be prepared as a metalworking fluid with excellent workability without substantially containing a sulfur-based extreme pressure agent, and the problem of corrosion of copper components can also be avoided.

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

[0020] In one embodiment of the present invention, the content of component (A), based on the total amount (100% by mass) of the water-soluble metalworking fluid excluding water, is 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 0.5% by mass or more, 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, even more preferably 2.5% by mass or more, and even more preferably 3.0% by mass. More preferably, the amount is 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. It may also 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. It 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] Furthermore, when using an emulsion-type oil preparation 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 preparation excluding water (100% by mass), and the upper limit is as stated above.

[0022] When using a soluble oil classified as type A2 as specified in JIS K2241:2017, 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 of the oil excluding water (100% by mass), and the lower limit is as stated above.

[0023] Furthermore, in a 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, it is 2.5% by mass or more, more preferably 3.0% by mass or more, even more preferably 3.5% by mass or more, particularly preferably 4.0% by mass or more, and may also 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, and although it is 100% by mass or less, considering 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] Furthermore, when using an emulsion-type oil preparation classified as type A1 as defined 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 preparation, and the upper limit is as stated above.

[0025] When using a soluble type oil classified as type A2 as specified in JIS K2241:2017, 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 (100% by mass) of the oil, and the lower limit is as stated above.

[0026] ≪Ingredient (A1): Oil-soluble polyalkylene glycol (oil-soluble PAG)≫ The component (A1) used in one aspect of the present invention is not particularly limited as long as it is a polyalkylene glycol (PAG) having constituent units derived from alkylene oxide and exhibiting oil solubility. In this specification, the determination of whether a PAG in question is oil-soluble or not is made by its miscibility with mineral oil classified as Group 1 of the API (American Petroleum Institute) base oil category. Specifically, a sample is prepared in which the content ratio of the control PAG to the mineral oil classified as Group 1 [PAG / mineral oil] is 10 / 90 or 90 / 10 by mass ratio, and the total light transmittance of the sample and standard sample at 25°C is measured. If the following criteria (i) and (ii) are met, it is determined to be an oil-soluble PAG. (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 descriptions in this specification, any ingredient described as "oil-soluble" is an ingredient that satisfies the above criteria (i) and (ii), unless otherwise specified.

[0027] Component (A1) used in one aspect of the present invention includes polymers having structural units derived from at least one of propylene oxide and butylene oxide, such as propylene oxide homopolymers, butylene oxide homopolymers, and propylene oxide-butylene oxide copolymers. In addition, component (A1) may be used alone, or two or more may be used in combination.

[0028] The kinematic viscosity of component (A1) used in one aspect of the present invention at 40°C 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, more preferably 15-350mm 2 / s, more preferably 20-250mm 2 / s, more preferably 23-180mm2 / s, more preferably 25-100mm 2 / s, more preferably 28.8~90mm 2 / s, particularly preferably 40-80 mm 2 It is / s.

[0029] Furthermore, from the viewpoint of providing a water-soluble metalworking fluid that can be used as a metalworking fluid with excellent workability, the viscosity grade of component (A1) used in one embodiment of the present invention, as defined in ISO 3448, 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, even more preferably VG46 or VG68, and particularly preferably VG68.

[0030] In a water-soluble metalworking fluid according to one aspect of the present invention, the content of component (A1) is, based on the total amount (100% by mass) of the water-soluble metalworking fluid excluding water, 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 0.5% by mass or more, 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, even more preferably 2.5% by mass or more, even more preferably 3.0% by mass or more, and still more preferably More preferably 4.0% by mass or more, 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. Furthermore, it may 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. Also, although it is 100% by mass or less, considering the content 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] Furthermore, when using an emulsion-type oil preparation 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 of the oil preparation excluding water (100% by mass), and the upper limit is as stated above.

[0032] When using a soluble oil classified as type A2 as specified in JIS K2241:2017, 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 of the oil excluding water (100% by mass), and the lower limit is as stated above.

[0033] ≪Component (A2): Base oil other than component (A1)≫ In one aspect of the present invention, the base oil (A2) other than component (A1) can be at least one selected from mineral oil and synthetic oil, other than oil-soluble PAG. In this specification, the aforementioned water-soluble polyalkylene glycol (water-soluble PAG) and methoxypolyethylene glycol (MPEG) are also included in component (A2), but the total content of 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 delamination, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, and hydrorefining.

[0035] Examples of the synthetic oil 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 oils such as polyol esters, dibasic acid esters, and phosphate esters; ether oils such as polyphenyl ethers; alkylbenzenes; alkylnaphthalenes; and synthetic oils (GTL) obtained by isomerizing waxes (GTL wax (Gas To Liquids WAX)) produced from natural gas by the Fischer-Tropsch method or the like.

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

[0037] <Component (B): Water> The water-soluble metalworking oil agent of one embodiment of the present invention may further contain water (B). By using a water-soluble metalworking oil agent containing water, it is possible to impart flame retardancy to make it a non-dangerous substance and improve the handling property during storage. The water as component (B) used in one embodiment of the present invention is not particularly limited, and may be any of, for example, distilled water, ion-exchanged water, tap water, industrial water, and the like.

[0038] In one embodiment of the present invention, the content of component (B) is 400 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 fluid, but 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 even more preferably 5 to 200 parts by mass. Furthermore, when using an emulsion-type oil classified as type A1 as specified in JIS K2241:2017, 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 stated above. Furthermore, in the case of a soluble type oil classified as type A2 as specified in JIS K2241:2017, 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 stated above.

[0039] In one embodiment of the present invention, the content of component (B) is preferably 1 to 99% by mass, more preferably 2 to 90% by mass, even more preferably 3 to 85% by mass, and even more preferably 5 to 80% by mass, based on the total amount (100% by mass) of the water-soluble metalworking fluid. Furthermore, when using 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 stated above. Furthermore, when using a soluble type oil classified as type A2 as specified in JIS K2241:2017, 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 stated above.

[0040] <Component (C): Amine compound> A water-soluble metalworking fluid according to one aspect of the present invention preferably further contains an amine compound (C). When a water-soluble metalworking fluid containing component (C) is mixed with diluting water to form a metalworking fluid, it can achieve a good emulsified state and become a metalworking fluid with improved antibacterial properties, rust prevention properties, and workability. In addition, component (C) may be used alone or in combination of two or more components.

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

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

[0043] Furthermore, in a water-soluble metalworking fluid according to one embodiment of the present invention, the content ratio of component (C) to component (A1) [(C) / (A1)] is preferably 0.01 to 30, more preferably 0.05 to 25, even more preferably 0.10 to 20, even more preferably 0.20 to 15, and particularly preferably 0.25 to 9.0 by mass ratio. It may also 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. It may also 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 aspect of the present invention may be any of the following: a monoamine having one amino nitrogen atom in one molecule, a diamine having two amino nitrogen atoms in one molecule, or a polyamine having three or more amino nitrogen atoms in one molecule. However, from the viewpoint of providing a water-soluble metalworking fluid that can be used as a metalworking fluid with improved antibacterial properties, rust prevention properties, and workability, it is preferable that component (C) used in one embodiment of the present invention contains a monoamine. The monoamine content is preferably 50-100% by mass, more preferably 60-100% by mass, more preferably 70-100% by mass, more preferably 75-100% by mass, even more preferably 80-100% by mass, even more preferably 85-100% by mass, even more preferably 90-100% by mass, even more preferably 95-100% by mass, and particularly preferably 98-100% by mass, based on the total amount (100% by mass) of component (C) contained in the water-soluble metalworking fluid.

[0045] In one aspect of the present invention, the monoamine used as component (C) is 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. Furthermore, from the viewpoint of providing a water-soluble metalworking fluid that, when diluted with water to form a metalworking fluid, exhibits good emulsification and improved antibacterial properties, rust prevention properties, and workability, 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 from one another. Examples of substituents include alkyl groups, alkyl groups having a hydroxyl group, alkenyl groups, cycloalkyl groups, phenyl groups, and benzyl groups.

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

[0048] Examples of alkyl groups having a hydroxyl group that can be selected as substituent R include groups in which at least one hydrogen atom of the above-mentioned alkyl group is substituted with a hydroxyl group. The alkyl group constituting the group may be a linear alkyl group or a branched alkyl group. The number of carbon atoms in the alkyl group having a hydroxyl group is preferably 1 to 30, more preferably 1 to 20, even more preferably 1 to 10, even more preferably 1 to 6, and particularly preferably 2 to 4.

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

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

[0051] In one aspect of the present invention, component (C) used 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 combined with diluted water to form a metalworking fluid, exhibits good emulsification and further improves antibacterial properties, rust prevention properties, and workability. Examples of alkanolamines include primary alkanolamines in which R in formula (i) is an alkyl group having a hydroxyl group, secondary alkanolamines in which at least one of R in formula (ii) is an alkyl group having a hydroxyl group, and tertiary alkanolamines in which at least one of R in 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; and diethanolamines and dipropanolamines.

[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-methyldiethanolamine. Examples include amines, 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, tripolamine (triisopropanolamine, etc.).

[0055] Among these, from the viewpoint of providing a water-soluble metalworking oil that, when diluted with water to form a metalworking fluid, exhibits good emulsification and further improves antibacterial properties, rust prevention properties, and workability, component (C) used in one aspect 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 content of alkanolamine is 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, even more preferably 35% by mass or more, and particularly preferably 40% by mass or more, based on the total amount (100% by mass) of component (C) contained in the water-soluble metalworking fluid. It may also be 45% by mass or more, 50% by mass or more, or 55% by mass or more, or 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] In one embodiment of the present invention, component (C) preferably includes an alicyclic amine. Examples of alicyclic amines include primary alicyclic amines in which R in formula (i) is a cycloalkyl group, secondary alicyclic amines in which at least one of R in formula (ii) is a cycloalkyl group, and tertiary alicyclic amines in which at least one of R in formula (iii) is a cycloalkyl group.

[0058] Examples of primary alicyclic amines include N-cyclohexylamines. Examples of secondary alicyclic amines include monocyclohexylamines such as N-methylcyclohexylamine, N-ethylcyclohexylamine, N-propylcyclohexylamine, and N-oleylcyclohexylamine; monocyclohexyl alkanolamines 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 tricyclohexylamines.

[0059] Furthermore, when using an emulsion-type oil preparation classified as type A1 as defined in JIS K2241:2017, component (C) preferably contains one or more selected from dialkylmonocyclohexylamine and monoalkyldicyclohexylamine, and more preferably contains monoalkyldicyclohexylamine. Furthermore, when using a soluble oil preparation classified as type A2 as specified in JIS K2241:2017, component (C) preferably contains one or more selected from monocyclohexyldialkanolamine and dicyclohexylalkanolamine, and more preferably contains monocyclohexyldialkanolamine.

[0060] The alicyclic amine content is preferably 10% by mass or more, more preferably 20% by mass or more, even more preferably 25% by mass or more, even more preferably 30% by mass or more, and particularly preferably 35% by mass or more, based on the total amount (100% by mass) of component (C) contained in the water-soluble metalworking fluid. It may also be 37% by mass or more, or 40% by mass or more. Furthermore, it 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] A water-soluble metalworking fluid according to one embodiment of the present invention may contain, as component (C), other amines other than alkanolamines and alicyclic amines (including diamines and polyamines). The content of other amines may be 0-50% by mass, 0-40% by mass, 0-30% by mass, 0-20% by mass, 0-10% by mass, 0-5.0% by mass, 0-2.0% by mass, 0-1.0% by mass, 0-0.10% by mass, 0-0.01% by mass, 0-0.001% by mass, 0-0.0001% by mass, or 0-0.00001% by mass, based on the total amount (100% by mass) of component (C) contained in the water-soluble metalworking fluid.

[0062] <Component (D): Fatty acids> A water-soluble metalworking fluid according to one embodiment of the present invention preferably further contains fatty acids (D). By including component (D), it is possible to create a water-soluble metalworking fluid that can further improve emulsification stability, rust prevention, and workability. In one embodiment of the present invention, in a water-soluble metalworking fluid, component (D) may be used alone or in combination of two or more components.

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

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

[0065] Furthermore, in a water-soluble metalworking fluid according to one embodiment of the present invention, the content ratio of component (D) to component (A1) [(D) / (A1)] 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, even more preferably 0.25 to 12.0, and particularly preferably 0.30 to 8.0 by mass ratio. It may also 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. It may also 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 embodiment of the present invention, in order to provide a water-soluble metalworking fluid that can be made into a metalworking fluid with good raw fluid stability and improved workability, the content ratio of component (C) to component (D) [(C) / (D)] is preferably 0.01 to 5.0 by mass, more preferably 0.05 to 4.0, more preferably 0.1 to 3.0, even more preferably 0.2 to 2.5, even more preferably 0.3 to 2.0, particularly preferably 0.5 to 1.5, and may also be 0.6 or more, 0.65 or more, 0.7 or more, 0.75 or more, or 0.8 or more, and may also be 1.4 or less, 1.3 or less, 1.2 or less, or 1.15 or less.

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

[0068] Examples of the aforementioned 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, arachidic acid, behenic acid, and isostearic acid, as well as unsaturated aliphatic monocarboxylic acids such as octenic acid, nonenic 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. Alternatively, a mixture of unsaturated fatty acids such as tall oil fatty acids, soybean oil fatty acids, palm oil fatty acids, flaxseed oil fatty acids, rice bran oil fatty acids, and cottonseed oil fatty acids may be used. The number of carbon atoms in the fatty acid is preferably 8 to 30, more preferably 10 to 25, and even more preferably 10 to 20.

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

[0070] Examples of the aliphatic dicarboxylic acid include saturated aliphatic dicarboxylic acids such as sebacic acid, dodecanediic acid, dodecylsuccinic acid, laurylsuccinic acid, stearylsuccinic acid, and isostearylsuccinic 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 hydroxyunsaturated fatty acids that constitute the polymerized fatty acids of the aforementioned hydroxyunsaturated fatty acids include ricinoleic acid (12-hydroxyoctadeca-9-enonic acid). Alternatively, a fatty acid mixture containing ricinoleic acid, such as castor oil, may be used. Examples of polymerized fatty acids of hydroxyunsaturated fatty acids include condensed fatty acids, which are dehydrated polycondensates of hydroxyunsaturated fatty acids (for example, castor oil polymerized fatty acids, which are dehydrated polycondensates of a fatty acid mixture mainly composed of ricinoleic acid), and condensed fatty acids obtained by dehydrated condensation of the alcoholic hydroxyl group of a condensed fatty acid, which is a dehydrated polycondensate of hydroxyunsaturated fatty acids, with a monocarboxylic acid.

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

[0073] The acid value of component (D) is typically 0 mg KOH / g or higher, preferably 10 to 100 mg KOH / g, more preferably 20 to 90 mg KOH / g, and even more preferably 30 to 80 mg KOH / g, from the viewpoint of providing a water-soluble metalworking fluid that can be used as a metalworking fluid with improved workability. The hydroxyl value of component (D) is preferably 0 to 80 mg KOH / g, more preferably 0 to 60 mg KOH / g, and even more preferably 0 to 40 mg KOH / g. From the above viewpoint, 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 180-220 mgKOH / g, more preferably 190-210 mgKOH / g, and even more preferably 195-205 mgKOH / g. In this specification, the acid value refers to the value measured in accordance with JIS K2501:2003 (indicator photometric titration method), the hydroxyl value refers to the value measured in accordance with JIS K0070:1992, and the saponification value refers to the value measured based on JIS K2503:1996.

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

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

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

[0077] In one aspect of the present invention, the HLB of component (E) used is preferably 6.0 or higher, more preferably 7.0 or higher, even more preferably 8.0 or higher, even more preferably 9.0 or higher, particularly preferably 10.0 or higher, and also 18.0 or lower, preferably 17.0 or lower, more preferably 16.0 or lower, even more preferably 15.0 or lower, and even more preferably 14.5 or lower, from the viewpoint of providing a water-soluble metalworking fluid that can become a metalworking fluid with improved emulsification stability and workability. In this specification, HLB refers to the value calculated by the Griffin method.

[0078] Examples of component (E) used in one aspect of the present invention include alkylene glycol, polyoxyalkylene alkyl ether, polyoxyalkylene aryl ether, polyoxyalkylene alkylamine (cocoamine alkylene oxide adduct), alkylphenol alkylene oxide adduct, higher alcohol alkylene oxide adduct, polyoxyalkylene fatty acid ester, fatty acid ester of glycerin and pentaerythritol, fatty acid ester of sucrose, fatty acid ester of polyoxyalkylene adduct of polyhydric alcohol, alkyl polyglycoside, fatty acid alkanolamide, and the like.

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

[0080] <Sulfur-based extreme pressure agent> Since the water-soluble metalworking fluid of the present invention contains oil-soluble PAG(A1) as a base oil (A), it is possible to prepare a metalworking fluid with excellent workability without containing sulfur-based extreme pressure agents, which are factors that cause corrosion of copper-containing components. Therefore, from the viewpoint of providing a water-soluble metalworking fluid that can be used as a metalworking fluid with a high inhibitory effect on corrosion of copper-containing components, it is preferable that the water-soluble metalworking fluid of one embodiment of the present invention substantially does not contain sulfur-based extreme pressure agents. Examples of sulfur-based extreme pressure agents include sulfurized olefins, sulfurized lards, alkyl polysulfides, and sulfurized fatty acids.

[0081] Furthermore, in this specification, "substantially free of sulfur-based extreme pressure agents" is a provision that rejects the inclusion of sulfur-based extreme pressure agents for a predetermined purpose, and does not reject the inclusion of sulfur-based extreme pressure agents unintentionally as impurities of other components. However, even considering such unintentional inclusion of sulfur-based extreme pressure agents, from the viewpoint of providing a water-soluble metalworking fluid that can effectively suppress the corrosion of copper-containing components, it is preferable to have as little sulfur-based extreme pressure agent content as possible. The specific amount of 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 parts by mass, even more preferably less than 0.01 parts by mass, and particularly preferably less than 0.001 parts by mass, based on 100 parts by mass of the total amount of component (A1) contained in the water-soluble metalworking fluid.

[0082] <Other various additives> A water-soluble metalworking fluid according to one aspect of the present invention may further contain various other additives other than the above components (A) to (E), as necessary, as long as the effects of the present invention are not impaired. Other types of additives include, for example, anionic surfactants, cationic surfactants, petroleum sulfonates, non-sulfur extreme pressure agents, metal deactivators, emulsifiers, antibacterial agents, defoamers, antioxidants, and oiliness agents. These various additives may be used individually or in combination of two or more.

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

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

[0085] Examples of anionic surfactants include polyoxyethylene alkyl ether carboxylic acid, polyoxyethylene alkyl ether phosphate, alkylbenzene sulfonic acid, α-olefin sulfonic acid, and salts thereof. The acid value of the anionic surfactant is preferably 20-250 mg KOH / g, more preferably 30-200 mg KOH / g, even more preferably 40-190 mg KOH / g, and even more preferably 50-180 mg KOH / 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 paraffins, chlorinated fatty acids, and chlorinated fatty oils; and phosphorus-based extreme pressure agents such as phosphate esters, phosphite esters, thiophosphate esters, and their salts, phosphine-based agents, and tricresyl phosphate.

[0088] Examples of metal deactivators include benzotriazole, imidazoline, pyrimidine derivatives, and thiadiazole.

[0089] Examples of emulsifying agents 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 isothiazolinoline compounds, triazine compounds, alkylbenzimidazole compounds, and metal pyrithione salts.

[0091] Examples of defoaming agents include silicone-based defoaming agents, fluorosilicone-based defoaming agents, and polyacrylates.

[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 for manufacturing water-soluble metalworking fluid> The method for producing a water-soluble metalworking fluid according to one aspect of the present invention is not particularly limited, but it is preferable to have a step of blending the above-mentioned component (A), and optionally components (B) to (E) and various other additives. The order in which each component is blended can be set as appropriate.

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

[0096] The ratio of base value to acid value [base value / acid value] of a water-soluble metalworking fluid according to 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, even more preferably 1.5 to 3.0, and particularly preferably 1.7 to 2.8. If the ratio is 1.0 or higher, a water-soluble metalworking fluid with good resistance to spoilage can be obtained. On the other hand, if the ratio is 4.0 or lower, the irritation to human skin can be reduced, which is preferable in terms of ease of handling.

[0097] [Form of metalworking fluid] The metalworking fluid of the present invention is prepared by using the metalworking oil according to one embodiment of the present invention described above as a stock solution, and by adding diluting water to the metalworking oil. The dilution water may be any of the following: distilled water, deionized water, tap water, industrial water, etc.

[0098] When preparing the metalworking fluid, the amount of diluting water added is more than 400 parts by mass relative to 100 parts by mass of the total amount of components other than water in the water-soluble metalworking fluid, but it is preferable to adjust it as appropriate 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 "dilution concentration of the metalworking fluid" refers to the 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]] × 100

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

[0100] There are no particular limitations on the workpiece to be processed using the metalworking fluid according to one embodiment of the present invention, but it 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 steel, aluminum alloys, and high-manganese steel. Among these, it is particularly suitable for workpieces having components containing at least iron or aluminum.

[0101] Therefore, the present invention may also provide the following [1] and [2]. [1] A method of use for applying the metalworking fluid of one embodiment of the present invention described above to a workpiece made of metal. [2] A metalworking method for processing a workpiece made of metal by applying a metalworking fluid according to one embodiment of the present invention described above.

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

[0103] In the above [1] and [2], examples of processing of the workpiece include cutting, grinding, punching, polishing, drawing, drawing, and rolling. Furthermore, in the method of use described in [1] above and the metalworking method described in [2] above, the metalworking fluid is prepared by mixing diluted water with the water-soluble metalworking oil according to one embodiment of the present invention described above, and then supplying it to the workpiece and bringing it into contact with the workpiece. The metalworking fluid lubricates the space between the workpiece and the workpiece. It is also used for chip removal, rust prevention of the workpiece, and cooling of the tool and the workpiece. [Examples]

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

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

[0106] <Ingredients (A1)> • Oil-soluble PAG(a-1): Oil-soluble polyalkylene glycol conforming to the viscosity grade VG32 as specified in ISO 3448. • Oil-soluble PAG(a-2): Oil-soluble polyalkylene glycol conforming to the viscosity grade VG46 as specified in ISO 3448. • Oil-soluble PAG(a-3): Oil-soluble polyalkylene glycol conforming to the viscosity grade VG68 specified in ISO 3448. <Ingredient (A2)> • Paraffinic mineral oil: kinematic viscosity at 40°C = 7.117 mm² 2 / s, paraffinic mineral oil with viscosity index = 109. <Ingredient (B)> • Water: Ion-exchanged water <Ingredient (C)> • Amine (c-1): N-methylethanolamine, secondary monoamine • Amine (c-2): N-cyclohexyldiethanolamine, tertiary monoamine • Amine (c-3): N-methyldiethanolamine, tertiary monoamine • Amine (c-4): Triisopropanolamine, tertiary monoamine • 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): Dodecane dioic 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-mol 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 • Emulsifying agent: 2-phenoxyethanol • Antibacterial agent: 1,2-benzoisothiazolin-3-one • Antifoaming agent: Silicone-based antifoaming agent

[0107] The acid value, base value, and base value / acid value ratio of the prepared water-soluble metalworking fluid were measured and calculated, and the following evaluations were performed using the water-soluble metalworking fluid. These results are shown in Tables 2 and 3. (1) Classification of oil-based formulations In accordance with JIS K2241:2017, the products were classified as either A1 type emulsion-type oil or A2 type soluble oil. In Tables 2 and 3, "E" indicates that the product was classified as an A1 type emulsion-type oil, and "S" indicates that it was classified as an A2 type soluble oil.

[0108] (2) Copper plate corrosion test The copper plates were tested using a test method compliant with JIS K2513, under conditions of 50°C oil temperature for 48 hours. The degree of discoloration of the copper plates was observed, and the degree of corrosion was evaluated based on "Table 1 Classification of Corrosion According to Standards for Corrosion of Copper Plates" of JIS K2513, as shown in Table 1 below. In Tables 2 and 3, the results are indicated by a "discoloration number (subdivision symbol)," where the discoloration number, a numerical value from 1 to 4, indicates the degree of corrosion of the copper plates, with a higher number indicating more advanced corrosion.

[0109] [Table 1]

[0110] (3) Evaluation of processability A metalworking fluid with a 5% by volume concentration was prepared by diluting a water-soluble metalworking fluid with deionized water. Using the prepared metalworking fluid, pilot hole drilling was performed under the following conditions, and then a tapping torque test was conducted to measure the maximum tapping torque during machining. Three measurements were taken, and the average and maximum values ​​are shown in Tables 2 and 3. The smaller the average and maximum values, the better the metalworking properties of the metalworking fluid used. <Conditions for drilling pilot holes> • Machine used: Tapping center MTV-T350 (manufactured by Mectron Co., Ltd.) • Drill: SG-ESS (manufactured by Fujikoshi Co., Ltd.), Drill diameter: 5.56mm ·Cutting speed: 31m / min • Rotation speed: 1798 min -1 Feed rate: 260 mm / min • Feed rate per revolution: 0.145 mm / rev • Depth: 15mm <Tapping Torque Test> • Test equipment used: Megatap II (micro-electronische Gerate GmbH) • Tap: New Roll Tap VP-NRT B M6 x 1 (manufactured by OSG Corporation) ·Cutting speed: 10m / min Feed rate: 1.0 mm / rev • Depth: 12mm ·Number of processing: 3 • Workpiece material: SCM440 (JIS standard) (chromium molybdenum steel)

[0111] [Table 2]

[0112] [Table 3]

[0113] Tables 2 and 3 show that the metalworking fluids prepared by diluting the water-soluble metalworking fluids of Examples 1 to 8, in both soluble and emulsion types, suppressed copper plate corrosion and exhibited 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 aspect: the effect of suppressing copper plate corrosion and workability.

Claims

1. It contains a base oil (A) containing oil-soluble polyalkylene glycol (A1) and water (B), The total content of water-soluble polyalkylene glycol and methoxypolyethylene glycol is less than 60% by mass on a total basis excluding water. A water-soluble metalworking fluid in which component (A1) has a viscosity grade specified in ISO 3448 of VG10, VG15, VG22, VG32, or VG46, A water-soluble metalworking fluid in which the water (B) content is 1 to 400 parts by mass relative to 100 parts by mass of the total amount of components other than water (B) in the water-soluble metalworking fluid.

2. The water-soluble metalworking fluid according to claim 1, wherein 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 (A1).

3. A water-soluble metalworking fluid according to claim 1 or 2, which substantially does not contain a sulfur-based extreme pressure agent.

4. The water-soluble metalworking fluid according to any one of claims 1 to 3, wherein the content ratio of component (A1) in component (A) is 10 to 100% by mass based on the total amount of component (A) contained in the water-soluble metalworking fluid.

5. The water-soluble metalworking fluid according to any one of claims 1 to 4, wherein the content of component (A1) is 0.01% by mass or more on a total basis excluding water in the water-soluble metalworking fluid.

6. Furthermore, the water-soluble metalworking fluid according to any one of claims 1 to 5 contains an amine compound (C).

7. Furthermore, the water-soluble metalworking fluid according to any one of claims 1 to 6 contains fatty acids (D).

8. The water-soluble metalworking fluid according to any one of claims 1 to 7, further containing a nonionic surfactant (E).

9. A water-soluble metalworking fluid according to any one of claims 1 to 8, which is an emulsion-type oil classified as type A1 as defined in JIS K2241:2017.

10. A water-soluble metalworking fluid according to any one of claims 1 to 8, which is a soluble type oil classified as type A2 as defined in JIS K2241:2017.

11. It contains a base oil (A) containing oil-soluble polyalkylene glycol (A1) and water (B), 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). A water-soluble metalworking fluid in which component (A1) has a viscosity grade specified in ISO 3448 of VG10, VG15, VG22, VG32, or VG46, A water-soluble metalworking fluid in which the water (B) content is 1 to 400 parts by mass relative to 100 parts by mass of the total amount of components other than water (B) in the water-soluble metalworking fluid.

12. A metalworking fluid comprising a water-soluble metalworking fluid according to any one of claims 1 to 11, and diluted with water.

13. A metalworking method comprising applying the metalworking fluid described in claim 12 to a workpiece made of metal.

14. The metalworking method according to claim 13, wherein the workpiece has a member containing at least iron or aluminum.

15. The metalworking method according to claim 13 or 14, which suppresses corrosion of copper-containing components that constitute a processing machine used for processing the aforementioned workpiece.

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