Water-soluble metalworking oil agent

Abstract

Provided is a water-soluble metalworking oil comprising two or more amine compounds (A) each having a volatility of 20% or less as calculated from the following formula (i) when heated at 50° C. for 48 hours, and a fatty acid (B), wherein a content of an amine compound (X) not corresponding to component (A) is less than 5.0 parts by mass based on 100 parts by mass of the total amount of component (A):Volatility⁢ (%)= ([Mass⁢ of⁢ amine⁢ compound⁢ before⁢ being⁢ heated]-
[Mass⁢ of⁢ amine⁢ compound⁢ after⁢ being⁢ heated⁢ for⁢ 48⁢ hours]) / ⁢
[Mass⁢ of⁢ amine⁢ compound⁢ before⁢ being⁢ heated]×100.Formula⁢ (i)

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 comprising processing a workpiece comprising metal by application of the metalworking fluid.BACKGROUND ART

[0002] In the art of metalworking such as cutting and grinding, metalworking fluids are used to increase workability for workpieces and to suppress wear of working tools.

[0003] Metalworking fluids include oil-based metalworking fluids containing oils such as mineral oils, synthetic oils, and animal and vegetable oils as main components, and water-soluble metalworking fluids provided with water solubility by blending an oil with a surface-active compound. Recently, water-soluble metalworking fluids are increasingly used for safety reasons such as a reduced risk of catching fire.

[0004] For example, Patent Literature 1 discloses an invention which relates to a concentrated metalworking fluid comprising from 60 to 90 percent by weight of base oil selected from the group consisting of water-soluble polyalkylene glycols, methoxypolyethylene glycols, and combinations of two or more thereof; from 5 to 20 percent by weight of glycol ether; 0.01 to 5 percent by weight of oil-soluble polyalkylene glycol; and from 0.2 to 6 percent by weight of additives.CITATION LISTPatent LiteraturePatent Literature 1: International Publication No. WO 2010 / 113594SUMMARY OF INVENTIONTechnical Problem

[0006] Meanwhile, the water-soluble metalworking fluid as in Patent Literature 1 is repeatedly used during metalworking, and is problematic in deterioration of characteristics resulting from long-term use.

[0007] Accordingly, the demand exists for a water-soluble metalworking oil capable of providing a metalworking fluid capable of maintaining its characteristics over a long period of time.Solution to Problem

[0008] The present invention provides a water-soluble metalworking oil containing two or more amine compounds and a fatty acid, wherein the specific volatility of the amine compounds is at a predetermined value or less, and the content of an amine compound having a specific volatility that exceeds the predetermined value is limited.

[0009] Specifically, the present invention provides, for example, the following embodiments [1] to

[13] :

[0010] [1] A water-soluble metalworking oil comprising two or more amine compounds (A) each having a volatility of 20% or less as calculated from the following formula (i) when heated at 50° C. for 48 hours, and a fatty acid (B), wherein

[0011] a content of an amine compound (X) not corresponding to component (A) is less than 5.0 parts by mass based on 100 parts by mass of the total amount of component (A):Volatility⁢ (%)=([Mass⁢ of⁢ amine⁢ compound⁢ before⁢ being⁢ heated]-[Mass⁢ of⁢ amine⁢ compound⁢ after⁢ being⁢ heated⁢ for⁢ 48⁢ hours]) / [Mass⁢ of⁢ amine⁢ compound⁢ before⁢ being⁢ heated]×100.Formula⁢ (i)[2] The water-soluble metalworking oil according to [1], wherein the content of component (A) is more than 5.0% by mass based on the total amount of the water-soluble metalworking oil.

[0013] [3] The water-soluble metalworking oil according to [1] or [2], wherein component (A) comprises at least two amine compounds (A1) each having a volatility of 10% or less.

[0014] [4] The water-soluble metalworking oil according to any one of [1] to [3], wherein the total content of a polyalkylene glycol having a weight-average molecular weight of 12,000 or less (Y1) and a water-insoluble compound having a polyoxyalkylene group (Y2) is less than 70% by mass based on the total amount of the water-soluble metalworking oil.

[0015] [5] The water-soluble metalworking oil according to any one of [1] to [4], wherein the content of the polyalkylene glycol having a weight-average molecular weight of 12,000 or less (Y1) is less than 15.0% by mass based on the total amount of the water-soluble metalworking oil.

[0016] [6] The water-soluble metalworking oil according to any one of [1] to [5], wherein the content of the water-insoluble compound having a polyoxyalkylene group (Y2) is less than 15.0, by mass based on the total amount of the water-soluble metalworking oil.

[0017] [7] The water-soluble metalworking oil according to any one of [1] to [6], wherein the content of component (B) is 5.0% by mass or more based on the total amount of the water-soluble metalworking oil.

[0018] [8] The water-soluble metalworking oil according to any one of [1] to [7], wherein a ratio of a base value derived from component (A) to an acid value derived from component (B) [(A) / (B)] is 0.50 to 10.0.

[0019] [9] The water-soluble metalworking oil according to any one of [1] to [8], further comprising a nonionic surfactant (C).

[0020]

[10] The water-soluble metalworking oil according to any one of [1] to [9], further comprising a base oil (D).

[0021]

[11] The water-soluble metalworking oil according to any one of [1] to

[10] , further comprising water (E).

[0022]

[12] A metalworking fluid obtained by blending the water-soluble metalworking oil of any one of [1] to

[11] with dilution water.

[0023]

[13] A metalworking method comprising processing a workpiece comprising metal by application of the metalworking fluid according to

[12] .Advantageous Effect of Invention

[0024] The water-soluble metalworking oil of one preferable embodiment of the present invention is capable of providing, by being diluted with dilution water, a metalworking fluid that has excellent thermal stability and decay resistance and can maintain its characteristics for a longer period of time.DESCRIPTION OF EMBODIMENT

[0025] Concerning the numerical ranges described herein, the upper limits and the lower limits can be suitably combined. For example, when a numerical range is described as being “preferably 30 to 100, and more preferably 40 to 80”, the range of “30 to 80” and the range of “40 to 100” are also included in the numerical range described herein. Moreover, for example, when a numerical range is described as being “preferably 30 or more and more preferably 40 or more, and preferably 100 or less and more preferably 80 or less”, the range of “30 to 80” and the range of “40 to 100” are also included in the numerical range described herein.

[0026] In addition, for example, “60 to 100” as a numerical range described herein means the range of “60 or more (60 or more than 60) and 100 or less (100 or less than 100)”.

[0027] Herein, the “metalworking oil” is a stock solution of a metalworking fluid before being diluted with dilution water to provide a metalworking fluid, and is in a form suitable for transportation and storage before being used in metalworking. The “metalworking fluid” is what is obtained by adding dilution water to a stock solution of a metalworking oil to dilute the stock solution, and is in a form suitable when used in metalworking.

[0028] The “metalworking oil” and the “metalworking fluid” can be distinguished according to, for example, the water content as follows:

[0029] “Metalworking oil”: the water content is 0 parts by mass or more and 400 parts by mass or less based on 100 parts by mass of the total amount of components other than water; and

[0030] “Metalworking fluid”: the water content is more than 400 parts by mass based on 100 parts by mass of the total amount of components other than water.[Configuration of Water-Soluble Metalworking Oil]

[0031] The water-soluble metalworking oil of the present invention is an oil prepared to contain two or more amine compounds (A) having a volatility of 20% or less as calculated from formula (i) (hereinafter also referred to as component (A)) and a fatty acid (B) (hereinafter also referred to as component (B)), wherein the content of an amine compound (X) not corresponding to component (A) (hereinafter also referred to as component (X)) is less than 5.0 parts by mass based on 100 parts by mass of the total amount of component (A).

[0032] Herein, the term “water-soluble” refers to a component that has a solubility of 20 g or more in 100 g of water at 25° C., and the total light transmittance of a solution at 25° C. obtained by adding 20 g of the component to 100 g of water at 25° C. is 90% or more.

[0033] The present inventors have found that the deterioration of characteristics that occurs when a metalworking fluid is used for a long period of time is due to the fact that an amine salt is formed from an amine compound and a fatty acid in the metalworking fluid, and the amine of the amine salt volatilizes with heat produced during metalworking.

[0034] The water-soluble metalworking oil of one embodiment of the present invention has been accomplished based on this finding, and contains amine compounds (A) each having a volatility of 20% or less as calculated from formula (i) and a fatty acid (B), wherein the content of an amine compound (X) that does not correspond to component (A) and also causes deterioration of characteristics is limited. Accordingly, it seems that, in a metalworking fluid prepared from the water-soluble metalworking oil of one embodiment of the present invention, the amine of the amine salt formed in the metalworking fluid unlikely volatilizes even with heat produced during metalworking, and its characteristics can be maintained for a long period of time.

[0035] The water-soluble metalworking oil of one embodiment of the present invention may further contain a nonionic surfactant (C) (hereinafter also referred to as “component (C)”).

[0036] The water-soluble metalworking oil of one embodiment of the present invention may further contain a base oil (D) (hereinafter also referred to as “component (D)”).

[0037] The water-soluble metalworking oil of one embodiment of the present invention may further contain water (E) (hereinafter also referred to as “component (E)”). By regulating the content of water (E), the water-soluble metalworking oil can be prepared into an emulsion-type oil classified as A1 or a soluble-type oil classified as A2 as stipulated in JIS K 2241:2017.

[0038] The water-soluble metalworking oil of one embodiment of the present invention preferably contains two or more selected from components (C), (D), and (E), and more preferably contains all components (C), (D), and (E).

[0039] The water-soluble metalworking oil of one embodiment of the present invention may contain a further component other than the components (A) to (E) as long as the effects of the present invention are not impaired.

[0040] In the water-soluble metalworking oil of one embodiment of the present invention, the total content of the components (A) and (B) is preferably 10% by mass or more, more preferably 15% by mass or more, even more preferably 20% by mass or more, yet more preferably 25% by mass or more, and particularly preferably 28% by mass or more, and may be 100% by mass or less, 90% by mass or less, 80% by mass or less, 70 by mass or less, 65 by mass or less, 60% by mass or less, 55% by mass or less, 50% by mass or less, or 48% by mass or less based on the total amount (100% by mass) of the water-soluble metalworking oil.

[0041] In the water-soluble metalworking oil of one embodiment of the present invention, the total content of the components (A) to (E) is preferably 40% by mass or more, more preferably 50% by mass or more, even more preferably 60% by mass or more, yet more preferably 70% by mass or more, further preferably 80% by mass or more, and particularly preferably 90% by mass or more, and may be 100% by mass or less, 99% by mass or less, 98% by mass or less, or 97% by mass or less based on the total amount (100% by mass) of the water-soluble metalworking oil.

[0042] Below, the respective components contained in the water-soluble metalworking oil of one embodiment of the present invention will now be described.<Component (A): Amine-based compound>

[0043] The water-soluble metalworking oil of one embodiment of the present invention contains two or more amine compounds (A) each having a volatility of 20% or less when heated at 50° C. for 48 hours as calculated from the following formula (i):Volatility⁢ (%)= ([Mass⁢ of⁢ amine⁢ compound⁢ before⁢ being⁢ heated]-
[Mass⁢ of⁢ amine⁢ compound⁢ after⁢ being⁢ heated⁢ for⁢ 48⁢ hours]) / ⁢
[Mass⁢ of⁢ amine⁢ compound⁢ before⁢ being⁢ heated]×100.Formula⁢ (i)

[0044] Herein, volatility refers to a value measured by the method described in the following Examples.

[0045] Due to component (A) contained in the water-soluble metalworking oil of one embodiment of the present invention, when the water-soluble metalworking oil is diluted to become a metalworking fluid, the amine of the amine salt formed from component (A) and component (B) in the metalworking fluid unlikely volatilizes even with heat produced during metalworking, and a metalworking fluid, the characteristics of which are maintained for a long period of time, can be obtained.

[0046] In the water-soluble metalworking oil of one embodiment of the present invention, from the viewpoint of providing a water-soluble metalworking oil capable of becoming a metalworking fluid that has excellent thermal stability and decay resistance and can maintain its characteristics for a longer period of time, the content of component (A) is preferably more than 5.0% by mass, 7.0% by mass or more, 9.0% by mass or more, 10.0% by mass or more, 11.0% by mass or more, 12.0% by mass or more, 14.0% by mass or more, 16.0% by mass or more, 18.0% by mass or more, 20.0% by mass or more, 22.0% by mass or more, 24.0% by mass or more, or 26.0% by mass or more, and may be 60.0% by mass or less, 55.0% by mass or less, 50.0% by mass or less, 45.0% by mass or less, 40.0% by mass or less, 37.0% by mass or less, 35.0% by mass or less, 32.0% by mass or less, or 30.0% by mass or less, based on the total amount (100% by mass) of the water-soluble metalworking oil.

[0047] In the water-soluble metalworking oil of one embodiment of the present invention, from the viewpoint of providing a water-soluble metalworking oil capable of becoming a metalworking fluid that has excellent thermal stability and decay resistance and can maintain its characteristics for a longer period of time, the content of component (A) is preferably more than 5.0% by mass, 7.0% by mass or more, 9.0% by mass or more, 10.0% by mass or more, 11.0% by mass or more, 12.0% by mass or more, 13.0% by mass or more, 15.0% by mass or more, 17.0% by mass or more, 20.0% by mass or more, 22.0% by mass or more, 24.0% by mass or more, 26.0% by mass or more, 28.0% by mass or more, or 30.0% by mass or more, and may be 70.0% by mass or less, 65.0% by mass or less, 60.0% by mass or less, 55.0% by mass or less, 50.0% by mass or less, 45.0% by mass or less, 40.0% by mass or less, 37.0% by mass or less, or 35.0% by mass or less, based on the total amount (100% by mass) of the water-soluble metalworking oil excluding water.

[0048] The volatility of component (A) used in one embodiment of the present invention, from the viewpoint of providing a water-soluble metalworking oil capable of becoming a metalworking fluid that has excellent thermal stability and decay resistance and can maintain its characteristics for a longer period of time, is preferably 20% or less, 18% or less, 16% or less, 14% or less, 12% or less, 11% or less, 10% or less, 9.0% or less, 8.0% or less, 7.0% or less, 6.04 or less, 5.0% or less, 4.0% or less, 3.0% or less, 2.0% or less, 1.0% or less, or 0.50% or less.

[0049] Component (A) used in one embodiment of the present invention, from the viewpoint of providing a water-soluble metalworking oil capable of becoming a metalworking fluid that has excellent thermal stability and decay resistance and can maintain its characteristics for a longer period of time, is composed of two or more amine compounds each having a volatility of 20% or less, and preferably contains at least two amine compounds (A1) each having a volatility of 10% or less.

[0050] The volatility of each amine compound (A1) is 10% or less and, from the above viewpoint, is more preferably 9.0% or less, 8.0% or less, 7.0%, or less, 6.0% or less, 5.0% or less, 4.0% or less, 3.0% or less, 2.0% or less, 1.0% or less, or 0.50% or less.

[0051] In the water-soluble metalworking oil of one embodiment of the present invention, from the viewpoint of providing a water-soluble metalworking oil capable of becoming a metalworking fluid that has excellent thermal stability and decay resistance and can maintain its characteristics for a longer period of time, the content of component (A1) is preferably 20% by mass or more, 25% by mass or more, 30% by mass or more, 35% by mass or more, 40% by mass or more, 45% by mass or more, 50% by mass or more, 55% by mass or more, 60% by mass or more, 65% by mass or more, 70% by mass or more, 75% by mass or more, 80% by mass or more, 85% by mass or more, 90% by mass or more, 95% by mass or more, 98% by mass or more, or 100% by mass based on the total amount (100% by mass) of component (A) contained in the water-soluble metalworking oil.

[0052] Component (A) used in one embodiment of the present invention is not particularly limited as long as the volatility is 20% or less, and may be, for example, any of the above monoamine having one amino nitrogen atom within one molecule, diamine having two amino nitrogen atoms within one molecule, and polyamine having 3 or more amino nitrogen atoms within one molecule.

[0053] However, from the viewpoint of having the volatility at a predetermined value or less, component (A) used in one embodiment of the present invention is preferably a monoamine.

[0054] The monoamine used as component (A) in one embodiment of the present invention may be any of a primary amine, a secondary amine, and a tertiary amine.

[0055] From the viewpoint of having the volatility at a predetermined value or less, the primary amine is preferably a primary amine compound represented by the following general formula (a-1), the secondary amine is preferably a secondary amine compound represented by the following general formula (a-2), and the tertiary amine is preferably a tertiary amine compound represented by the following general formula (a-3):

[0056] In general formula (a-1), p1 and p2 are each independently an integer of 0 to 10, preferably an integer of 1 to 6, more preferably an integer of 1 to 4, even more preferably an integer of 2 or 3, and yet more preferably 2.

[0057] x1 is 0 or 1.

[0058] The primary amine compound represented by general formula (a-1) is preferably 2-(2-aminoethoxy)ethanol.

[0059] In general formula (a-2), R11 to R14 are each independently a hydrogen atom, a hydroxyl group, a linear or branched alkyl group optionally substituted with a hydroxyl group, or a phenyl group.

[0060] The alkyl group that can be selected as R11 to R14 preferably has 1 to 12 carbon atoms, more preferably 1 to 10 carbon atoms, even more preferably 1 to 6 carbon atoms, and yet more preferably 1 to 3 carbon atoms.

[0061] Note that, preferably at least one of R11 and R13 is a hydrogen atom, and the other is a group other than a hydrogen atom, and preferably at least one of R12 and R14 is a hydrogen atom, and the other is a group other than a hydrogen atom.

[0062] X1 and X2 each independently represent an oxygen atom, an oxyethylene group, or an oxypropylene group. p3 and p4 are each independently an integer of 0 to 10, preferably an integer of 0 to 6, and more preferably an integer of 0 to 3.

[0063] The secondary amine compound represented by general formula (a-2) is preferably diisopropanolamine or dibenzylamine, and more preferably dibenzylamine.

[0064] In general formula (a-3), R21 to R24 are each independently a hydrogen atom, a hydroxyl group, a linear or branched alkyl group optionally substituted with a hydroxyl group, or a phenyl group.

[0065] The alkyl group that can be selected as R21 to R24 preferably has 1 to 12 carbon atoms, more preferably 1 to 10 carbon atoms, even more preferably 1 to 6 carbon atoms, and yet more preferably 1 to 3 carbon atoms.

[0066] Note that, preferably at least one of R21 and R23 is a hydrogen atom, and the other is a group other than a hydrogen atom, and preferably at least one of R22 and R24 is a hydrogen atom, and the other is a group other than a hydrogen atom.

[0067] X3 and X4 are each independently an oxygen atom, an oxyethylene group, or an oxypropylene group. p3 and p4 each independently represent an integer of 0 to 10, preferably an integer of 0 to 6, and more preferably an integer of 0 to 3.

[0068] R31 is a linear or branched alkyl group optionally substituted with a hydroxyl group, a phenyl group, or a cyclohexyl group.

[0069] The alkyl group that can be selected as R31 preferably has 1 to 12 carbon atoms, more preferably 1 to 10 carbon atoms, even more preferably 1 to 6 carbon atoms, and yet more preferably 1 to 3 carbon atoms.

[0070] The tertiary amine compound represented by general formula (a-3) is preferably N-methyldiethanolamine, triethanolamine, triisopropanolamine, cyclohexyldiethanolamine, or polyoxyalkylenealkylamine, and more preferably includes at least cyclohexyldiethanolamine or polyoxyalkylenealkylamine.

[0071] Examples of the alkyl group that can be selected as R11 to R14, R21 to R24, and R31 in general formulae (a-2) to (a-3) include a methyl group, an ethyl group, a propyl group (an n-propyl group, an i-propyl group), a butyl group (an n-butyl group, an i-butyl group, an s-butyl group, a t-butyl group), a pentyl group (an n-pentyl group, an i-pentyl group, a neopentyl group), a hexyl group, a heptyl group, an octyl group, a 2-ethylhexyl group, a nonyl group, a decyl group, an undecyl group, and a dodecyl group.

[0072] The alkyl group may be a linear alkyl group or may be a branched alkyl group.

[0073] Component (A) used in one embodiment of the present invention is composed of a combination of two or more, and specific examples include the following combinations:

[0074] (i) a combination of at least one primary amine and at least one secondary amine;

[0075] (ii) a combination of at least one primary amine and at least one tertiary amine;

[0076] (iii) a combination of at least one secondary amine and at least one tertiary amine;

[0077] (iv) a combination of at least one primary amine, at least one secondary amine, and at least one tertiary amine;

[0078] (v) a combination of at least two primary amines;

[0079] (vi) a combination of at least two secondary amines; and

[0080] (vii) a combination of at least two tertiary amines.

[0081] Among the above combinations, from the viewpoint of providing a water-soluble metalworking oil capable of becoming a metalworking fluid that has excellent thermal stability and decay resistance and can maintain its characteristics for a longer period of time, combination (i), (ii), (iii), (iv), (vi), or (vii) is preferable, combination (i), (ii), (iv), (vi), or (vii) is more preferable, combination (i), (iv), or (vii) is even more preferable, and combination (iv) or (vii) is yet more preferable.

[0082] The base value (amine value) of component (A) used in one embodiment of the present invention, from the viewpoint of providing a water-soluble metalworking oil capable of becoming a metalworking fluid that has excellent thermal stability and decay resistance and can maintain its characteristics for a longer period of time, is preferably 560 mgKOH / g or less, 550 mgKOH / g or less, or 540 mgKOH / g or less, and is preferably more than 100 mgKOH / g, 150 mgKOH / g or more, or 170 mgKOH / g or more.

[0083] When a primary amine compound is used as component (A), the base value (amine value) of the primary amine compound, from the viewpoint of providing a water-soluble metalworking oil capable of becoming a metalworking fluid that has excellent thermal stability and decay resistance and can maintain its characteristics for a longer period of time, is preferably 560 mgKOH / g or less, 550 mgKOH / g or less, or 540 mgKOH / g or less, and preferably more than 100 mgKOH / g, 150 mgKOH / g or more, 170 mgKOH / g or more, 200 mgKOH / g or more, 250 mgKOH / g or more, 300 mgKOH / g or more, 350 mgKOH / g or more, 400 mgKOH / g or more, 450 mgKOH / g or more, or 500 mgKOH / g or more.

[0084] When a secondary amine compound is used as component (A), the base value (amine value) of the secondary amine compound, from the viewpoint of providing a water-soluble metalworking oil capable of becoming a metalworking fluid that has excellent thermal stability and decay resistance and can maintain its characteristics for a longer period of time, is preferably 570 mgKOH / g or less, 550 mgKOH / g or less, 530 mgKOH / g or less, 500 mgKOH / g or less, 470 mgKOH / g or less, 450 mgKOH / g or less, 430 mgKOH / g or less, 400 mgKOH / g or less, 370 mgKOH / g or less, 350 mgKOH / g or less, 330 mgKOH / g or less, or 300 mgKOH / g or less, and is preferably more than 100 mgKOH / g, 150 mgKOH / g or more, 170 mgKOH / g or more, 200 mgKOH / g or more, or 250 mgKOH / g or more.

[0085] When a tertiary amine compound is used as component (A), the base value (amine value) of the tertiary amine compound, from the viewpoint of providing a water-soluble metalworking oil capable of becoming a metalworking fluid that has excellent thermal stability and decay resistance and can maintain its characteristics for a longer period of time, is preferably 570 mgKOH / g or less, 550 mgKOH / g or less, 530 mgKOH / g or less, 500 mgKOH / g or less, 470 mgKOH / g or less, 450 mgKOH / g or less, 430 mgKOH / g or less, 400 mgKOH / g or less, 370 mgKOH / g or less, 350 mgKOH / g or less, 330 mgKOH / g or less, or 300 mgKOH / g or less, and is preferably more than 100 mgKOH / g, 150 mgKOH / g or more, or 170 mgKOH / g or more.

[0086] Herein, the base value (amine value) means a value measured in accordance with JIS K 2501:2003 (HCl method).<Component (X): Amine Compound not Corresponding to Component (A)>

[0087] In the water-soluble metalworking oil of one embodiment of the present invention, from the viewpoint of providing a water-soluble metalworking oil capable of becoming a metalworking fluid that has excellent thermal stability and decay resistance and can maintain its characteristics for a longer period of time, the content of the amine compound not corresponding to component (A), (X), is limited to less than 5.0 parts by mass based on 100 parts by mass of the total amount of component (A).

[0088] From the above viewpoint, in the water-soluble metalworking oil of one embodiment of the present invention, the content of component (X) is preferably less than 4.5 parts by mass, less than 4.0 parts by mass, less than 3.0 parts by mass, less than 2.0 parts by mass, less than 1.0 part by mass, less than 0.50 parts by mass, less than 0.10 parts by mass, less than 0.01 parts by mass, less than 0.001 parts by mass, or less than 0.0001 parts by mass based on 100 parts by mass of the total amount of component (A).

[0089] Also, from the above viewpoint, in the water-soluble metalworking oil of one embodiment of the present invention, the content of component (X) is preferably less than 1.0% by mass, less than 0.10% by mass, less than 500 ppm by mass, less than 100 ppm by mass, less than 50 ppm by mass, less than 10 ppm by mass, less than 5.0 ppm by mass, or less than 1.0 ppm by mass based on the total amount (100% by mass) of the water-soluble metalworking oil.<Component (B): Fatty Acid>

[0090] The water-soluble metalworking oil of one embodiment of the present invention contains a fatty acid (B).

[0091] Containing component (B), the water-soluble metalworking oil is capable of becoming a metalworking fluid having various improved characteristics such as emulsion stability, antirust properties, and workability.

[0092] In the water-soluble metalworking oil of one embodiment of the present invention, one component (B) may be used singly, or two or more may be used in combination.

[0093] In the water-soluble metalworking oil of one embodiment of the present invention, the content of component (B) is preferably 2.0% by mass or more, 3.0% by mass or more, 5.0% by mass or more, 7.0% by mass or more, 10.0% by mass or more, 12.0% by mass or more, 14.0% by mass or more, or 16.0% by mass or more, and is preferably 60% by mass or less, 50% by mass or less, 40% by mass or less, 35% 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 water-soluble metalworking oil.

[0094] In the water-soluble metalworking oil of one embodiment of the present invention, the content of component (B) is preferably 2.0% by mass or more, 3.0% by mass or more, 5.0% by mass or more, 7.0% by mass or more, 10.0% by mass or more, 12.0% by mass or more, 14.0% by mass or more, 16.0% by mass or more, or 18.0% by mass, and is preferably 60% by mass or less, 50% by mass or less, 40% by mass or less, 35% by mass or less, 30% by mass or less, 25% by mass or less, or 22% by mass or less, based on the total amount (100% by mass) of the water-soluble metalworking oil excluding water.

[0095] Examples of component (B) used in one embodiment of the present invention include fatty acid, hydroxy fatty acid, aliphatic dicarboxylic acid, dimer acid of fatty acid, and polymerized fatty acid of hydroxy unsaturated fatty acid.

[0096] Examples of the fatty acid include saturated aliphatic monocarboxylic acid 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, and unsaturated aliphatic monocarboxylic acid 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.

[0097] A mixture of unsaturated fatty acid may be used, such as tall oil fatty acid, soybean oil fatty acid, palm oil fatty acid, linseed oil fatty acid, rice bran oil fatty acid, and cottonseed oil fatty acid.

[0098] 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.

[0099] Examples of the hydroxy fatty acid include hydroxylauric acid, hydroxymyristic acid, hydroxypalmitic acid, hydroxystearic acid, hydroxyarachic acid, hydroxybehenic acid, and hydroxyoctadecenoic acid.

[0100] The number of carbon atoms of the hydroxy fatty acid is preferably 8 to 30, more preferably 10 to 25, and even more preferably 10 to 20 carbon atoms.

[0101] Examples of the aliphatic dicarboxylic acid include sebacic acid, dodecanedioic acid, dodecylsuccinic acid, laurylsuccinic acid, stearylsuccinic acid, and isostearylsuccinic acid.

[0102] The number of carbon atoms of the aliphatic dicarboxylic acid is preferably 8 to 30, more preferably 10 to 25, and even more preferably 10 to 20 carbon atoms.

[0103] Examples of the hydroxy unsaturated fatty acid constituting a polymerized fatty acid of the hydroxy unsaturated fatty acid include ricinoleic acid (12-hydroxyoctadec-9-enoic acid). A fatty acid mixture containing recinoleic acid, such as castor oil polymerized fatty acid, may be used.

[0104] Examples of the polymerized fatty acid of the hydroxy unsaturated fatty acid include condensed fatty acid that is a dehydrative polycondensation product of hydroxy unsaturated fatty acid, and condensed fatty acid obtained by dehydratively condensing an alcoholic hydroxyl group of condensed fatty acid that is a dehydrative polycondensation product of hydroxy unsaturated fatty acid and monocarboxylic acid.

[0105] Component (B) used in one embodiment of the present invention preferably contains at least one selected from dodecanedioic acid, neodecanoic acid, tall oil fatty acid, and castor oil-polymerized fatty acid, more preferably contains at least two selected from dodecanedioic acid, neodecanoic acid, tall oil fatty acid, and castor oil-polymerized fatty acid, even more preferably contains at least three selected from dodecanedioic acid, neodecanoic acid, tall oil fatty acid, and castor oil-polymerized fatty acid, and yet more preferably contains all of dodecanedioic acid, neodecanoic acid, tall oil fatty acid, and castor oil-polymerized fatty acid.

[0106] From the viewpoint of providing a water-soluble metalworking oil capable of becoming a metalworking fluid having more increased workability, the acid value of component (B) is usually 0 mgKOH / g or more, is preferably 5 mgKOH / g or more, 10 mgKOH / g or more, 15 mgKOH / g or more, or 20 mgKOH / g or more, and may be 100 mgKOH / g or less, 90 mgKOH / g or less, 80 mgKOH / g or less, 70 mgKOH / g or less, 60 mgKOH / g or less, 50 mgKOH / g or less, 40 mgKOH / g or less, or 30 mgKOH / g or less.

[0107] The hydroxyl value of component (B) is preferably 80 mgKOH / g or less, 60 mgKOH / g or less, 40 mgKOH / g or less, 20 mgKOH / g or less, 10 mgKOH / g or less, or 5 mgKOH / g or less, and may be 0 mgKOH / g or more, 0.1 mgKOH / g or more, or 0.5 mgKOH / g or more.

[0108] From the above viewpoint, the ratio of the acid value to the hydroxyl value of component (B) [acid value / hydroxyl value] is preferably 1.5 or more, 2.0 or more, 2.5 or more, 5.0 or more, 10 or more, 12 or more, 15 or more, 17 or more, or 19 or more, and is preferably 50 or less, 40 or less, 35 or less, 30 or less, or 25 or less.

[0109] The saponification value of component (B) is preferably 10 mgKOH / g or more, 20 mgKOH / g or more, 40 mgKOH / g or more, 60 mgKOH / g or more, 100 mgKOH / g or more, 150 mgKOH / g or more, 180 mgKOH / g or more, 190 mgKOH / g or more, or 195 mgKOH / g or more, and is preferably 300 mgKOH / g or less, 250 mgKOH / g or less, 220 mgKOH / g or less, 210 mgKOH / g or less, or 205 mgKOH / g or less.

[0110] Herein, the acid value means a value measured in accordance with JIS K 2501:2003 (indicator photometric titration method), the hydroxyl value means a value measured in accordance with JIS K 0070:1992, and the saponification value means a value measured in accordance with JIS K 2503:1996.

[0111] In the water-soluble metalworking oil of one embodiment of the present invention, from the viewpoint of providing a water-soluble metalworking oil capable of becoming a metalworking fluid that has excellent thermal stability and decay resistance and can maintain its characteristics for a longer period of time, the ratio of the base value (amine value) derived from component (A) to the acid value derived from component (B) [(A) / (B)] is preferably 0.50 or more, 0.60 or more, 0.70 or more, 0.80 or more, 0.90 or more, 1.00 or more, 1.10 or more, 1.20 or more, 1.30 or more, 1.40 or more, 1.50 or more, 1.60 or more, 1.70 or more, 1.80 or more, 1.90 or more, 2.00 or more, 2.20 or more, 2.40 or more, 2.50 or more, 2.60 or more, 2.80 or more, or 3.00 or more, and is preferably 10.0 or less, 9.0 or less, 8.0 or less, 7.0 or less, 6.5 or less, 6.0 or less, 5.5 or less, 5.0 or less, 4.5 or less, 4.0 or less, or 3.5 or less.<Nonionic Surfactant (C)>

[0112] Preferably, the water-soluble metalworking oil of one embodiment of the present invention further contains a nonionic surfactant (C). Containing component (C), the water-soluble metalworking oil is capable of becoming a metalworking fluid having more increased emulsion stability and workability.

[0113] In the water-soluble metalworking oil of one embodiment of the present invention, one component (C) may be used singly, or two or more may be used in combination.

[0114] From the above viewpoint, in the water-soluble metalworking oil of one embodiment of the present invention, the content of component (C) is preferably 0.10% by mass or more, 0.30% by mass or more, 0.50% by mass or more, 0.70% by mass or more, 1.00% by mass or more, 1.20% by mass or more, 1.50, by mass or more, 1.70% by mass or more, 2.00% by mass or more, 2.20% by mass or more, 2.50% by mass or more, or 2.70% by mass or more, and is preferably 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, 4.5% by mass or less, or 4.0% by mass or less, based on the total amount (100% by mass) of the water-soluble metalworking oil.

[0115] From the above viewpoint, in the water-soluble metalworking oil of one embodiment of the present invention, the content of component (C) is preferably 0.20% by mass or more, 0.40% by mass or more, 0.60% by mass or more, 0.80% by mass or more, 1.00% by mass or more, 1.20% by mass or more, 1.50% by mass or more, 1.70% by mass or more, 2.00% by mass or more, 2.20% by mass or more, 2.50% by mass or more, 2.70% by mass or more, or 3.00% by mass or more, and is preferably 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, 4.5% by mass or less, or 4.0% by mass or less, based on the total amount (100% by mass) of the water-soluble metalworking oil excluding water.

[0116] From the viewpoint of providing a water-soluble metalworking oil capable of becoming a metalworking fluid having more increased emulsion stability and workability, the HLB of component (C) 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, yet 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 yet more preferably 14.5 or less.

[0117] Herein, HLB means a value calculated by Griffin's method.

[0118] Examples of component (C) used in one embodiment of the present invention include alkylene glycol, polyoxyalkylene alkyl ether, polyoxyalkylene aryl ether, polyoxyalkylenealkylamine (a cocoamine alkylene oxide adduct), an alkylphenol alkylene oxide adduct, a higher alcohol alkylene oxide adduct, a polyoxyalkylene fatty acid ester, a fatty acid ester of glycerin and pentaerythritol, a fatty acid ester of sucrose, a fatty acid ester of a polyoxyalkylene adduct of polyhydric alcohol, alkyl polyglycoside, and fatty acid alkanolamide.

[0119] Among these, from the viewpoint of providing a water-soluble metalworking oil capable of becoming a metalworking fluid having more increased emulsion stability and workability, component (C) used in one embodiment of the present invention preferably contains one or more selected from polyoxyalkylene alkyl ether and polyoxyalkylenealkylamine.

[0120] The total content of polyoxyalkylene alkyl ether and polyoxyalkylene alkylamine is preferably 50 to 100% by mass, more preferably 70 to 100, by mass, even more preferably 80 to 100% by mass, yet more preferably 90 to 100% by mass, and particularly preferably 95 to 100% by mass based on the total amount (100% by mass) of component (C) contained in the water-soluble metalworking oil.<Component (D): Base Oil>

[0121] Preferably, the water-soluble metalworking oil of the present invention further contains a base oil (D). Containing component (D), the water-soluble metalworking oil is capable of becoming a metalworking fluid having more increased workability.

[0122] One component (D) may be used singly in one embodiment of the present invention, or two or more may be used in combination.

[0123] In the water-soluble metalworking oil of one embodiment of the present invention, the content of component (D) may be 0.01% by mass or more, 0.1% by mass or more, 1.0% by mass or more, 3.0% by mass or more, 5.0% by mass or more, 10.0% by mass or more, 20.0% by mass or more, 25.0% by mass or more, 30.0% by mass or more, 35.0% by mass or more, or 40.0% by mass or more, and may be 80% by mass or less, 70% by mass or less, 65% by mass or less, 60% by mass or less, 55 by mass or less, 50 by mass or less, 45% by mass or less, 40% by mass or less, or 35% by mass or less, based on the total amount (100% by mass) of the water-soluble metalworking oil.

[0124] When forming an emulsion-type oil classified as A1 as stipulated in JIS K 2241:2017, 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.

[0125] When forming a soluble-type oil classified as A1 as stipulated in JIS K 2241:2017, 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.

[0126] In the water-soluble metalworking oil of one embodiment of the present invention, the content of component (D) may be 0.01% by mass or more, 0.1% by mass or more, 1.0% by mass or more, 3.0% by mass or more, 5.0% by mass or more, 10.0% by mass or more, 20.0% by mass or more, 25.0% by mass or more, 30.0% by mass or more, 35.0% by mass or more, or 40.0% by mass or more, and may be 80% by mass or less, 70% by mass or less, 65% by mass or less, 60% by mass or less, 55% by mass or less, 50% by mass or less, 45% by mass or less, 40% by mass or less, or 35% by mass or less based on the total amount (100% by mass) of the water-soluble metalworking oil excluding water.

[0127] When providing an emulsion-type oil classified as A1 as stipulated in JIS K 2241:2017, the content of component (D) 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 excluding water.

[0128] When providing a soluble-type oil classified as A2 as stipulated in JIS K 2241:2017, the content of component (D) 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 excluding water.

[0129] Component (D) used in one embodiment of the present invention may be one or more selected from mineral oils and synthetic oils.

[0130] Examples of mineral oils include atmospheric residue obtained by performing atmospheric distillation on crude oil such as paraffinic crude oil, intermediate crude oil, and naphthenic crude oil; distillate obtained by performing vacuum distillation on such atmospheric residue; and refined oil obtained by performing on such distillate one or more refining treatments such as solvent deasphalting, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, and hydrorefining.

[0131] Examples of synthetic oils include polyα-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); isoparaffin; ester oils such as polyol esters, dibasic acid esters, and phosphoric acid esters; ether oils such as polyphenyl ether; alkylbenzene; alkyl naphthalene; synthetic oils (GTL) obtained by isomerizing wax (GTL wax (Gas-To-Liquids WAX)) produced from natural gas by Fischer-Tropsch process or the like.

[0132] From the viewpoint of providing a water-soluble metalworking oil capable of becoming a metalworking fluid having excellent workability, the kinematic viscosity at 40° C. of component (D) used in one embodiment of the present invention is preferably 2.0 to 150 mm2 / s, more preferably 3.0 to 120 mm2 / s, even more preferably 5.0 to 100 mm2 / s, yet more preferably 6.0 to 90 mm2 / s, and particularly preferably 7.0 to 80 mm2 / s.<Component (E): Water>

[0133] The water-soluble metalworking oil of one embodiment of the present invention may further contain water (E). Containing water, the water-soluble metalworking oil becomes flame retardant and thus has good handleability as a non-hazardous material during storage.

[0134] Water, which is component (E) used in one embodiment of the present invention, is not particularly limited, and may be, for example, distilled water, ion exchanged water, tap water, or water for industrial use.

[0135] In the water-soluble metalworking oil of one embodiment of the present invention, the content of component (E) is 400 parts by mass or less, preferably 1 to 350 parts by mass, more preferably 2 to 300 parts by mass, more preferably 3 to 250 parts by mass, and even more preferably 5 to 200 parts by mass based on 100 parts by mass of the total amount of components other than water of the water-soluble metalworking oil.

[0136] When providing an emulsion-type oil classified as A1 as stipulated in JIS K 2241:2017, the content of component (E) 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 based on 100 parts by mass of the total amount of components excluding water in the water-soluble metalworking oil, and the lower limit is as described above.

[0137] When providing a soluble-type oil classified as A2 as stipulated in JIS K 2241:2017, the content of component (E) 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 based on 100 parts by mass of the total amount of components excluding water in the water-soluble metalworking oil, and the upper limit is as described above.

[0138] In the water-soluble metalworking oil of one embodiment of the present invention, the content of component (E) is preferably 1 to 99% by mass, more preferably 2 to 90% by mass, even more preferably 3 to 85% by mass, and yet more preferably 5 to 80% by mass based on the total amount (100% by mass) of the water-soluble metalworking oil.

[0139] When providing an emulsion-type oil classified as A1 as stipulated in JIS K 2241:2017, the content of component (E) 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.

[0140] When providing a soluble-type oil classified as A2 as stipulated in JIS K 2241:2017, the content of component (E) may be 10% by mass or more, 15% by mass or more, 20% by mass or more, 25% by mass or more, 30% by mass or more, 35% 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 water-soluble metalworking oil, and the upper limit is as described above.<Polyalkylene Glycol (Y1), Water-Insoluble Compound Having Polyoxyalkylene Group (Y2)>

[0141] In the water-soluble metalworking oil of one embodiment of the present invention, the total content of the polyalkylene glycol having a weight-average molecular weight of 12,000 or less (Y1) (hereinafter also referred to as “component (Y1)”) and the water-insoluble compound having a polyoxyalkylene group (Y2) (hereinafter also referred to as “component (Y2)”) may be less than 70% by mass, 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 15% by mass, less than 10% by mass, or less than 5.0% by mass based on the total amount (100% by mass) of the water-soluble metalworking oil.

[0142] In the water-soluble metalworking oil of one embodiment of the present invention, the content of component (Y1) may be less than 45.0% by mass, less than 40.0% by mass, less than 35.0% by mass, less than 30.0% by mass, less than 25.0% by mass, less than 20.0% by mass, less than 15.0% by mass, less than 10.0% by mass, or less than 5.0% by mass based on the total amount (100% by mass) of the water-soluble metalworking oil.

[0143] In the water-soluble metalworking oil of one embodiment of the present invention, the content of component (Y2) may be less than 40.0% by mass, less than 30.0% by mass, less than 20.0% by mass, less than 15.0% by mass, less than 10.0% by mass, less than 5.0% by mass, less than 1.0% by mass, less than 0.1% by mass, less than 0.01% by mass, less than 0.001% by mass, less than 0.0001% by mass, or less than 0.00001% by mass based on the total amount (100% by mass) of the water-soluble metalworking oil.<Other Various Additives>

[0144] The water-soluble metalworking oil of one embodiment of the present invention may further contain, as necessary, other various additives other than the above components (A) to (E) as long as the effects of the present invention are not impaired.

[0145] Examples of such other various additives include anionic surfactants, cationic surfactants, petroleum sulfonates, extreme pressure agents, metal deactivators, emulsification aids, antibacterial agents, antifoaming agents, antioxidants, and oily agents.

[0146] One of these various additives may be used singly, or two or more may be used in combination.

[0147] In the water-soluble metalworking oil of one embodiment of the present invention, the content of each of these various additives is suitably set according to the type and the function of each component, and is preferably 0.01 to 40% by mass, 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 oil.

[0148] In the water-soluble metalworking oil of one embodiment of the present invention, the content of each of these various additives is suitably set according to the type and the function of each component, and may be 0.001% by mass or more, 0.01% by mass or more, 0.1% by mass or more, 1.0% by mass or more, or 3.0% by mass or more, and may be 20% by mass or less, 15% by mass or less, 10% by mass or less, 5.0% by mass or less, or 1.0% by mass or less, based on the total amount (100% by mass) of the water-soluble metalworking oil.

[0149] The water-soluble metalworking oil of one embodiment of the present invention may be substantially free of certain additives among these various additives. The phrase “substantially free of” excludes embodiments wherein an additive of interest is added with a specific intention, but does not exclude embodiments wherein an additive is unavoidably contained.

[0150] The additive content in embodiments wherein the water-soluble metalworking oil is substantially free of such additives may be less than 0.1% by mass, less than 0.01% by mass, less than 0.001% by mass, less than 0.0001% by mass, or less than 0.00001% by mass based on the total amount (100% by mass) of the water-soluble metalworking oil.

[0151] Examples of the anionic surfactant include polyoxyethylene alkyl ether carboxylic acids, polyoxyethylene alkyl ether phosphoric acids, alkylbenzene sulfonic acids, α-olefinsulfonic acids, and salts thereof.

[0152] The acid value of anionic surfactants is preferably 20 to 250 mgKOH / g, more preferably 30 to 200 mgKOH / g, even more preferably 40 to 190 mgKOH / g, and yet more preferably 50 to 180 mgKOH / g.

[0153] Examples of cationic surfactants include alkyltrimethylammonium salts, dialkyldimethylammonium salts, and alkyldimethylbenzylammonium salts.

[0154] In the water-soluble metalworking oil of one embodiment of the present invention, the content of the anionic surfactant and the cationic surfactant may be less than 0.1% by mass, less than 0.01% by mass, less than 0.001% by mass, less than 0.0001% by mass, or less than 0.00001% by mass based on the total amount (100% by mass) of the water-soluble metalworking oil.

[0155] Examples of petroleum sulfonates include calcium sulfonate, sodium sulfonate, and magnesium sulfonate.

[0156] In the water-soluble metalworking oil of one embodiment of the present invention, the content of petroleum sulfonate may be less than 0.1% by mass, less than 0.01% by mass, less than 0.001% by mass, less than 0.0001% by mass, or less than 0.00001% by mass based on the total amount (100% by mass) of the water-soluble metalworking oil.

[0157] Examples of extreme pressure agents include chloric extreme pressure agents such as chlorinated paraffin, chlorinated fatty acids, and chlorinated fatty oils; phosphoric extreme pressure agents such as phosphoric esters, phosphorous esters, thiophosphoric esters, salts thereof, phosphines, and tricresyl phosphate; and sulfuric extreme pressure agents such as olefin sulfides, sulfurized lard oil, alkyl polysulfides, and fatty acid sulfides.

[0158] In the water-soluble metalworking oil of one embodiment of the present invention, the content of each of the chloric extreme pressure agents, phosphoric extreme pressure agents, and sulfuric extreme pressure agents may be less than 0.1% by mass, less than 0.01% by mass, less than 0.001% by mass, less than 0.0001% by mass, or less than 0.00001% by mass based on the total amount (100% by mass) of the water-soluble metalworking oil.

[0159] Examples of metal deactivators include benzotriazoles, imidazolines, pyrimidine derivatives, and thiadiazoles.

[0160] Examples of emulsifying aids include unsaturated fatty acid esters such as methyl oleate, ethyl oleate, and propyl oleate; and aromatic alcohols such as 2-phenoxyethanol and 2-phenylethyl alcohol.

[0161] Examples of antibacterial agents include isothiazoline compounds, triazine compounds, alkylbenzimidazole compounds, and metal pyrithione salts.

[0162] Examples of antifoaming agents include silicone antifoaming agents, fluorosilicone antifoaming agents, and polyacrylates.

[0163] Examples of antioxidants include amine antioxidants such as alkylated diphenylamine, phenylnaphthylamine, and alkylated phenylnaphthylamine; and phenolic 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.

[0164] In the water-soluble metalworking oil of one embodiment of the present invention, the content of the antioxidant may be less than 0.1 by mass, less than 0.01% by mass, less than 0.001% by mass, less than 0.0001% by mass, or less than 0.00001% by mass based on the total amount (100% by mass) of the water-soluble metalworking oil.

[0165] Examples of oily agents include alcohols such as lauryl alcohol, myristyl alcohol, palmityl alcohol, stearyl alcohol, and oleyl alcohol.<Method for Producing Water-Soluble Metalworking Oil>

[0166] The method for producing a water-soluble metalworking oil of one embodiment of the present invention is not particularly limited, and is preferably a method comprising the step of blending the above component (A) and (B) and, optionally, the components (C) to (E) and various other additives. The order of blending the respective components can be suitably set.[Form of Metalworking Fluid]

[0167] The metalworking fluid of one embodiment of the present invention is obtained by using the above metalworking oil of one embodiment of the present invention as a stock solution, and adding dilution water to the metalworking oil.

[0168] Dilution water may be any of, for example, distilled water, ion exchanged water, tap water, or water for industrial use.

[0169] The amount of dilution water added when preparing the metalworking fluid is more than 400 parts by mass based on 100 parts by mass of the total amount of components other than water of the water-soluble metalworking oil and, preferably, is suitably regulated so as to attain a desired dilute concentration.

[0170] The dilute concentration of the metalworking fluid of 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.

[0171] Herein, the “dilute concentration of the metalworking fluid” means a value calculated from the following equation:“Dilute⁢ concentration⁢ of⁢ metalworking⁢ fluid⁢ (%⁢ by⁢ volume)”=[⁠Volume⁢ of⁢ metalworking⁢ oil⁢ before⁢ dilution] / [[Volume⁢ of⁢ metalworking⁢ oil⁢ before⁢ dilution]+[Volume⁢ of⁢ dilution⁢ water]]×100.[Applications of Metalworking Fluid, and Metalworking Method]

[0172] The metalworking fluid of one suitable embodiment of the present invention has better thermal stability and decay resistance and can maintain its characteristics for a longer period of time than conventional metalworking fluids. Accordingly, the metalworking fluid of one suitable embodiment of the present invention is repeatedly usable in metalworking applications, and thus consumption of oil can be suppressed.

[0173] The workpiece to be processed using the metalworking fluid of one embodiment of the present invention is not particularly limited, and the metalworking fluid is particularly suitable for workpieces composed of metals selected from the group consisting of iron, titanium, aluminum, titanium alloy, alloy steel, nickel-based alloy, niobium alloy, tantalum alloy, molybdenum alloy, tungsten alloy, stainless steel, aluminum alloy, and high-manganese steel. Among these, the metalworking fluid is particularly suitable for a workpiece having a member containing at least iron or aluminum.

[0174] Accordingly, the present invention can also provide [1] and [2] below:

[0175] [1] A method of use comprising applying the above metalworking fluid of one embodiment of the present invention to processing of a metal workpiece.

[0176] [2] A metalworking method comprising applying the above metalworking fluid of one embodiment of the present invention to process a metal workpiece.

[0177] The workpiece set forth in [1] and [2] is as described above, and is suitably a workpiece having a member containing at least iron or aluminum.

[0178] In [1] and [2], examples of processing of the workpiece include cutting, grinding, punching, polishing, spinning, drawing, and rolling.

[0179] In the method of use according to [1] and the metalworking method according to [2], the metalworking fluid is used such that the above water-soluble metalworking oil of one embodiment of the present invention is blended with dilution water and then fed to, and thus brought into contact with, the workpiece. The metalworking fluid provides lubrication between the workpiece and the work tool. Moreover, the metalworking fluid is also used to remove swarf, prevent rust of the workpiece, cool the tool and the work piece, and the like.EXAMPLES

[0180] Next, the present invention will now be described in more detail by way of Examples, but the present invention is not limited to these Examples in any way.

[0181] In the following Examples, the methods for measuring and calculating the following physical property values are as follows:(1) Volatility of Amine Compound

[0182] 20 g of a measurement-target amine compound was weighed on an electronic balance in a glass petri dish having a diameter of 70 mm (manufactured by Kenis Ltd.), and the petri dish was placed without a lid in a precision thermostatic oven equipped with an explosion vent (Fine Oven) (manufactured by Yamato Scientific Co., Ltd., model “DF412S”). With the vent fully open, the temperature was raised from 25° C. to 50° C. over 30 minutes, the amine compound was heated at 50° C. for 48 hours, the mass of the heated amine compound was measured with the electronic balance, and the volatility was calculated from the following formula:Volatility⁢ (%)= ([Mass⁢ of⁢ amine⁢ compound⁢ before⁢ being⁢ heated⁢ (20⁢ g)]-
[Mass⁢ of⁢ amine⁢ compound⁢ after⁢ being⁢ heated⁢ for⁢ 48⁢ hours⁢ (g)]) / ⁢
[Mass⁢ of⁢ amine⁢ compound⁢ before⁢ being⁢ heated⁢ (20⁢ g)]×100.(2) Base Value (HCl Method)

[0183] Measured in accordance with JIS K 2501:2003 (HCl method).(3) Acid Value (Indicator Photometric Titration Method)

[0184] Measured in accordance with JIS K 2501:2003 (indicator photometric titration method).(4) Hydroxyl Value

[0185] Measured in accordance with JIS K 0070:1992.(5) HLB

[0186] Calculated based on Griffin's method.(6) Kinematic Viscosity, Viscosity Index

[0187] Measured and calculated in accordance with JIS K 2283:2000.Examples 1 to 19, Comparative Examples 1 to 20

[0188] Various components of the types shown in Tables 1 to 4 were added and mixed in the amounts shown in each Table to prepare respective water-soluble metalworking oils. The content of the polyalkylene glycol having a weight average molecular weight (Mw) of 12,000 or less (Y1) and the content of the water-insoluble compound having a polyoxyalkylene group (Y2) in the prepared water-soluble metal processing oil were both “0% by mass”.

[0189] Details of each component used in the preparation of the water-soluble metalworking oils are as follows.<Component (A)>“2-(2-Aminoethoxy)ethanol”: primary amine, volatility=4.00%, base value=534 mgKOH / g.

[0191] “Diisopropanolamine”: secondary amine, volatility=11.00%, base value=365 mgKOH / g.

[0192] “Dibenzylamine”: secondary amine, volatility=2.00%, base value=279 mgKOH / g.

[0193] “N-methyldiethanolamine”: tertiary amine, volatility=7.00%, base value=434 mgKOH / g.

[0194] “Triisopropanolamine”: tertiary amine, volatility=8.00%, base value=249 mgKOH / g.

[0195] “Cyclohexyldiethanolamine”: tertiary amine, volatility=0.10%, base value=297 mgKOH / g.

[0196] “POE alkylamine (EO: 2)”: tertiary amine, polyoxyethylene (2EO) alkylamine, volatility=0.10%, base value=200 mgKOH / g.<Component (X)>“Monoisopropanolamine”: primary amine, volatility=100.00%, base value=747 mgKOH / g.

[0198] “2-Amino-2-methyl-1-propanol”: primary amine, volatility=100.00t, base value=565 mg KOH / g.

[0199] “N-Methylethanolamine”: primary amine, volatility=100.00%, base value=747 mgKOH / g.

[0200] “Dicyclohexylamine”: primary amine, volatility=61.00%, base value=309 mgKOH / g.

[0201] “N-Methyldicyclohexylamine”: primary amine, volatility=28.00%, base value=287 mgKOH / g.<Component (B)>“Fatty acid mixture”: Fatty acid mixture primarily containing dodecanedioic acid, neodecanoic acid, tall oil fatty acid, and licinoleic acid-polymerized fatty acid (castor oil-polymerized fatty acid), acid value=22.0 mgKOH / g, hydroxyl value=1.1 mgKOH / g.<Component (C)>“Polyoxyalkylene alkyl ether”: nonionic surfactant, HLB=12.7.<Component (D)>“Paraffinic mineral oil”: Paraffinic mineral oil with 40° C. kinematic viscosity=7.117 mm2 / s and viscosity index=109.“PAO”: Synthetic poly-α-olefinic oil with 40° C. kinematic viscosity=31.0 mm2 / s and viscosity index=132.“Ester-based synthetic oil”: Trimethylolpropane trioleate with 40° C. kinematic viscosity=49.45 mm2 / s and viscosity index=189.<Component (E)>Water: Ion-exchange water<Other Additives>Benzotriazole: Metal inactivator“Oleyl alcohol”: Oily agent“1,2-Benzoisothiazolin-3-one”: Antibacterial agent

[0211] “Silicone anti-foaming agent”

[0212] The following evaluations were carried out using the prepared water-soluble metalworking oils. The results thereof are shown in Tables 1 to 4.(1) Fume Color Test

[0213] Approximately 0.1 mL of a water-soluble metalworking oil was added dropwise onto cold-rolled steel sheet (SPCC-SD) heated to 80° C., and the opening of a glass bottle having a volume of 50 mL was brought into contact with the cold-rolled steel sheet so as to cover the dripped oil, the oil was left to stand still in this state for one minute, and the fumed components of the oil were collected. Thereafter, an aqueous thymol blue solution (color changes from yellow to blue in alkaline environment) was added to the fume components collected in the glass bottle to check color change, and the volatility of the alkaline components was evaluated based on the following criteria:

[0214] A: No color change. No volatilization of alkaline components including amine compound was confirmed.

[0215] F: Color changed to blue. Volatilization of alkaline components including amine compound was confirmed.(2) Thermal Stability Test

[0216] A metalworking fluid prepared by diluting a water-soluble metalworking oil having an oil concentration of 5% by volume with water was used as a test solution.

[0217] 20 g of the test solution was added dropwise to a petri dish having a diameter of 70 mm, and the weight of the petri dish was measured. The solution was heated at 50° C. for 24 hours (1 day) without placing the lid on the petri dish, ion-exchange water corresponding to the reduced weight of the test solution due to heating was added, and the pH of the test solution was then measured using a pH meter (product name “HM-25R”, manufactured by DKK-TOA Corporation). This pH value is shown in Tables 1 to 4 as “pH after heating for 24 hours”.

[0218] The above “heating at 50° C. for 24 hours” and “addition of ion-exchange water corresponding to the reduced weight” were repeated for 7 days (a heating time of 168 hours), and the pH of the test solution was then measured. This pH value is shown in Tables 1 to 4 as “pH after heating for 168 hours”.

[0219] If the test solution separated before the heating time reached 168 hours, and pH measurement was not possible, the test solution was regarded as being “not measurable”, the water-soluble metalworking oil was judged as having inferior thermal stability, and the procedure was terminated without performing subsequent operations.

[0220] It can be said that the smaller the difference between “pH after heating for 24 hours” and “pH after heating for 168 hours” is, the better the heat stability the water-soluble metalworking oil has.(3) Decay Resistance Test[Preparation of Test Solution]

[0221] A metalworking fluid having an oil concentration of 3% by volume, which was prepared by diluting a water-soluble metalworking oil with water, was regarded a “test solution before thermal deterioration”.

[0222] A metalworking fluid obtained by heating 100 mL of the test solution before thermal deterioration at 50° C. for 48 hours and adding ion-exchange water corresponding to the reduced weight was regarded as a “test solution after thermal deterioration”. If the test solution was separated by 48 hours of heating, and was not possible to prepare the “test solution after thermal deterioration”, the test solution was regarded as being “not measurable”, and the procedure was terminated without performing the subsequent decay resistance test using the “test solution after thermal deterioration”.[Decay Resistance Test]

[0223] First, 5 mL of decay solution A and 0.5 mL of decay solution B described below were added to 100 mL of the “test solution before thermal deterioration” or the “test solution after thermal deterioration”, and the test solution was subjected to shaking culture at 30° C. at 150 rpm for one week (7 days).

[0224] After one week of culturing, the number of viable bacteria in the test solution was measured, and if the number of bacteria was 106 / mL or more, the test was terminated. If the number of bacteria was less than 106 / mL, additionally 2.5 mL of decay solution A and 0.25 mL of decay solution B were added, then shaking culture was carried out again for one week (7 days), and the number of viable bacteria was measured. The number of weeks each test solution needed to reach 106 bacteria / mL or more is shown in Tables 1 to 4. It can be said that the greater the number of weeks is, the better decay resistance the water-soluble metalworking oil has.

[0225] The decay test conditions and the method for measuring the number of viable bacteria are as follows.(Decay Test Conditions)Culture conditions: 3 g of FC200 dry chips were added and subjected to shaking culture at 30° C. at 150 rpm.

[0227] Decay solution A: Solution obtained by adding an SCD medium “Daigo” (product name, manufactured by Nihon Pharmaceutical Co., Ltd.) to a decayed, emulsion-type cutting fluid, and activating the mixture by aeration for 72 hours.

[0228] Decay solution B: Solution obtained by adding a potato dextrose agar medium “Daigo” (product name, manufactured by Nihon Pharmaceutical Co., Ltd.) to a decayed, emulsion-type cutting fluid, and activating the mixture by aeration for 72 hours.(Method for Measuring Number of Viable Bacteria)

[0229] The number of bacteria in 1 mL was measured using a total bacteria count analyzer “SAN-AI Bio Checker TTC” (product name, manufactured by SAN-AI OBBLI Co., Ltd.).TABLE 1Exam-Exam-Exam-Exam-Exam-ple 1ple 2ple 3ple 4ple 5CompositionComponentPrimary amine2-(2-Aminoethoxy)ethanol (4.00%)% by mass4.607.00of oil(A)SecondaryDiisopropanolamine (11.00%)% by mass6.8010.20amineDibenzylamine (2.00%)% by mass8.008.008.00TertiaryN-Methyldiethanolamine (7.00%)% by mass5.70amineTriisopropanolamine (8.00%)% by massCyclohexyldiethanolamine (0.10%)% by massPOE alkylamine (EO:2) (0.10%)% by mass5.005.00ComponentPrimaryMonoisopropanolamine (100.00%)% by mass(X)amine2-Amino-2-methyl-1-propanol% by mass(100.00%)SecondaryN-Methylethanolamine% by massamine(100.00%)Dicyclohexylamine (61.00%)% by massTertiaryN-Methyldicyclohexylamine% by massamine(28.00%)ComponentFatty acidFatty acid mixture% by mass17.5017.5017.5017.5017.50(B)ComponentNonionicPolyoxyalkylene% by mass3.003.003.003.003.00(C)surfactantalkyl etherComponentBase oilParaffinic% by mass55.8056.2053.4053.0054.50(D)mineral oilPAO% by massEster-based% by masssynthetic oilComponentWaterWater% by mass8.008.008.008.008.00(E)OtherMetal deactivatorBenzotriazole% by mass1.001.001.001.001.00additivesOily agentOleyl alcohol% by mass2.002.002.002.002.00Antibacterial1,2-Benzo-% by mass0.200.200.200.200.20agentisothiazolin-3-oneAntifoamingSilicone% by mass0.100.100.100.100.10agentantifoaming agent—Total% by mass100.00100.00100.00100.00100.00Total content of component (A)% by mass12.6012.0014.8015.2013.70Content of component (X) based on 100 partspart by00000by mass of total amount of component (A)massBase value derived from component (A) / —1.741.751.751.751.74Acid value derived from component (B)Content of component (A1) having% by mass100.0100.054.132.9100.0volatility of 10% or less in totalamount (100% by mass) of component (A)Content of polyalkylene glycol having% by mass00000Mw of 12,000 or less (Y1)Content of water-insoluble compound% by mass00000having polyoxyalkylene group (Y2)EvaluationFume color test—AAAAAitemThermalpH after heating—9.69.69.69.69.4stability testfor 24 hourspH after heating—9.59.59.49.49.3for 168 hoursDecay resistanceTest solution beforeweek44443testthermal deteriorationTest solution afterweek44443thermal deteriorationExam-Exam-Exam-Exam-Exam-ple 6ple 7ple 8ple 9ple 10CompositionComponentPrimary amine2-(2-Aminoethoxy)ethanol (4.00%)% by massof oil(A)SecondaryDiisopropanolamine (11.00%)% by massamineDibenzylamine (2.00%)% by mass8.008.00TertiaryN-Methyldiethanolamine (7.00%)% by mass8.50amineTriisopropanolamine (8.00%)% by mass10.0015.00Cyclohexyldiethanolamine (0.10%)% by mass8.4012.50POE alkylamine (EO:2) (0.10%)% by mass5.005.005.00ComponentPrimaryMonoisopropanolamine (100.00%)% by mass(X)amine2-Amino-2-methyl-1-propanol% by mass(100.00%)SecondaryN-Methylethanolamine% by massamine(100.00%)Dicyclohexylamine (61.00%)% by massTertiaryN-Methyldicyclohexylamine% by massamine(28.00%)ComponentFatty acidFatty acid mixture% by mass17.5017.5017.5017.5017.50(B)ComponentNonionicPolyoxyalkylene% by mass3.003.003.003.003.00(C)surfactantalkyl etherComponentBase oilParaffinic% by mass54.7050.2048.2051.8050.70(D)mineral oilPAO% by massEster-based% by masssynthetic oilComponentWaterWater% by mass8.008.008.008.008.00(E)OtherMetal deactivatorBenzotriazole% by mass1.001.001.001.001.00additivesOily agentOleyl alcohol% by mass2.002.002.002.002.00Antibacterial1,2-Benzo-% by mass0.200.200.200.200.20agentisothiazolin-3-oneAntifoamingSilicone% by mass0.100.100.100.100.10agentantifoaming agent—Total% by mass100.00100.00100.00100.00100.00Total content of component (A)% by mass13.5018.0020.0016.4017.50Content of component (X) based on 100 partspart by00000by mass of total amount of component (A)massBase value derived from component (A) / —1.741.751.751.751.75Acid value derived from component (B)Content of component (A1) having% by mass100.0100.0100.0100.0100.0volatility of 10% or less in totalamount (100% by mass) of component (A)Content of polyalkylene glycol having% by mass00000Mw of 12,000 or less (Y1)Content of water-insoluble compound% by mass00000having polyoxyalkylene group (Y2)EvaluationFume color test—AAAAAitemThermalpH after heating—9.59.39.39.49.4stability testfor 24 hourspH after heating—9.49.39.39.49.4for 168 hoursDecay resistanceTest solution beforeweek43345testthermal deteriorationTest solution afterweek43345thermal deteriorationTABLE 2Exam-Exam-Exam-Exam-Exam-ple 11ple 12ple 13ple 14ple 15CompositionComponentPrimary amine2-(2-Aminoethoxy)ethanol (4.00%)% by mass4.004.0012.005.00of oil(A)SecondaryDiisopropanolamine (11.00%)% by mass7.00amineDibenzylamine (2.00%)% by mass8.008.008.008.008.00TertiaryN-Methyldiethanolamine (7.00%)% by mass3.00amineTriisopropanolamine (8.00%)% by massCyclohexyldiethanolamine (0.10%)% by mass5.0012.0012.00POE alkylamine (EO:2) (0.10%)% by massComponentPrimaryMonoisopropanolamine (100.00%)% by mass(X)amine2-Amino-2-methyl-1-propanol% by mass(100.00%)SecondaryN-Methylethanolamine% by massamine(100.00%)Dicyclohexylamine (61.00%)% by massTertiaryN-Methyldicyclohexylamine% by massamine(28.00%)ComponentFatty acidFatty acid mixture% by mass17.5017.5017.5017.5017.50(B)ComponentNonionicPolyoxyalkylene% by mass3.003.003.003.003.00(C)surfactantalkyl etherComponentBase oilParaffinic% by mass53.2051.2048.2043.2041.20(D)mineral oilPAO% by massEster-based% by masssynthetic oilComponentWaterWater% by mass8.008.008.008.008.00(E)OtherMetal deactivatorBenzotriazole% by mass1.001.001.001.001.00additivesOily agentOleyl alcohol% by mass2.002.002.002.002.00Antibacterial1,2-Benzo-% by mass0.200.200.200.200.20agentisothiazolin-3-oneAntifoamingSilicone% by mass0.100.100.100.100.10agentantifoaming agent—Total% by mass100.00100.00100.00100.00100.00Total content of component (A)% by mass15.0017.0020.0025.0027.00Content of component (X) based on 100 partspart by00000by mass of total amount of component (A)massBase value derived from component (A) / —2.102.173.203.143.09Acid value derived from component (B)Content of component (A1) having% by mass100.0100.0100.0100.074.1volatility of 10% or less in totalamount (100% by mass) of component (A)Content of polyalkylene glycol having% by mass00000Mw of 12,000 or less (Y1)Content of water-insoluble compound% by mass00000having polyoxyalkylene group (Y2)EvaluationFume color test—AAAAAitemThermalpH after heating—9.59.69.89.59.5stability testfor 24 hourspH after heating—9.59.59.89.59.5for 168 hoursDecay resistanceTest solution beforeweek45565testthermal deteriorationTest solution afterweek45565thermal deteriorationExam-Exam-Exam-Exam-ple 16ple 17ple 18ple 19CompositionComponentPrimary amine2-(2-Aminoethoxy)ethanol (4.00%)% by mass4.604.60of oil(A)SecondaryDiisopropanolamine (11.00%)% by massamineDibenzylamine (2.00%)% by mass8.008.00TertiaryN-Methyldiethanolamine (7.00%)% by mass3.108.50amineTriisopropanolamine (8.00%)% by massCyclohexyldiethanolamine (0.10%)% by mass8.0012.00POE alkylamine (EO:2) (0.10%)% by mass5.005.00ComponentPrimaryMonoisopropanolamine (100.00%)% by mass(X)amine2-Amino-2-methyl-1-propanol% by mass(100.00%)SecondaryN-Methylethanolamine% by massamine(100.00%)Dicyclohexylamine (61.00%)% by massTertiaryN-Methyldicyclohexylamine% by massamine(28.00%)ComponentFatty acidFatty acid mixture% by mass17.5017.5017.5017.50(B)ComponentNonionicPolyoxyalkylene% by mass3.003.003.003.00(C)surfactantalkyl etherComponentBase oilParaffinic% by mass52.1042.70(D)mineral oilPAO% by mass55.60Ester-based% by mass55.60synthetic oilComponentWaterWater% by mass8.008.008.008.00(E)OtherMetal deactivatorBenzotriazole% by mass1.001.001.001.00additivesOily agentOleyl alcohol% by mass2.002.002.002.00Antibacterial1,2-Benzo-% by mass0.200.200.200.20agentisothiazolin-3-oneAntifoamingSilicone% by mass0.100.100.100.10agentantifoaming agent—Total% by mass100.00100.00100.00100.00Total content of component (A)% by mass16.1025.5012.6012.60Content of component (X) based on 100 partspart by0000by mass of total amount of component (A)massBase value derived from component (A) / —1.753.061.741.74Acid value derived from component (B)Content of component (A1) having% by mass100.0100.0100.0100.0volatility of 10% or less in totalamount (100% by mass) of component (A)Content of polyalkylene glycol having% by mass0000Mw of 12,000 or less (Y1)Content of water-insoluble compound% by mass0000having polyoxyalkylene group (Y2)EvaluationFume color test—AAAAitemThermalpH after heating—9.39.29.29.6stability testfor 24 hourspH after heating—9.39.28.79.5for 168 hoursDecay resistanceTest solution beforeweek4455testthermal deteriorationTest solution afterweek4455thermal deteriorationTABLE 3Com-Com-Com-Com-Com-par-par-par-par-par-ativeativeativeativeativeExam-Exam-Exam-Exam-Exam-ple 1ple 2ple 3ple 4ple 5CompositionComponentPrimary amine2-(2-Aminoethoxy)ethanol (4.00%)% by massof oil(A)SecondaryDiisopropanolamine (11.00%)% by massamineDibenzylamine (2.00%)% by massTertiaryN-Methyldiethanolamine (7.00%)% by massamineTriisopropanolamine (8.00%)% by massCyclohexyldiethanolamine (0.10%)% by massPOE alkylamine (EO:2) (0.10%)% by massComponentPrimaryMonoisopropanolamine (100.00%)% by mass3.003.20(X)amine2-Amino-2-methyl-1-propanol% by mass4.004.30(100.00%)SecondaryN-Methylethanolamine% by mass3.00amine(100.00%)Dicyclohexylamine (61.00%)% by mass8.008.008.00TertiaryN-Methyldicyclohexylamine% by mass8.008.00amine(28.00%)ComponentFatty acidFatty acid mixture% by mass17.5017.5017.5017.5017.50(B)ComponentNonionicPolyoxyalkylene% by mass3.003.003.003.003.00(C)surfactantalkyl etherComponentBase oilParaffinic% by mass57.2057.0056.2055.9057.20(D)mineral oilPAO% by massEster-based% by masssynthetic oilComponentWaterWater% by mass8.008.008.008.008.00(E)OtherMetal deactivatorBenzotriazole% by mass1.001.001.001.001.00additivesOily agentOleyl% by mass2.002.002.002.002.00alcoholAntibacterial1,2-Benzo-% by mass0.200.200.200.200.20agentisothiazolin-3-oneAntifoamingSilicone% by mass0.100.100.100.100.10agentantifoaming agent—Total% by mass100.00100.00100.00100.00100.00Total content of component (A)% by mass00000Content of component (X) based on 100 partspart by—————by mass of total amount of component (A)massBase value derived from component (A) / —1.741.741.751.751.75Acid value derived from component (B)Content of component (A1) having% by mass—————volatility of 10% or less in totalamount (100% by mass) of component (A)Content of polyalkylene glycol having% by mass00000Mw of 12,000 or less (Y1)Content of water-insoluble compound% by mass00000having polyoxyalkylene group (Y2)EvaluationFume color test—FFFFFitemThermalpH after heating—9.69.69.69.69.6stability testfor 24 hourspH after heating—(*1)8.5(*1)8.5(*1)for 168 hoursDecay resistanceTest solution beforeweek54544testthermal deteriorationTest solution afterweek(*2)1(*2)1(*2)thermal deteriorationCom-Com-Com-Com-Com-par-par-par-par-par-ativeativeativeativeativeExam-Exam-Exam-Exam-Exam-ple 6ple 7ple 8ple 9ple 10CompositionComponentPrimary amine2-(2-Aminoethoxy)ethanol (4.00%)% by mass2.00of oil(A)SecondaryDiisopropanolamine (11.00%)% by massamineDibenzylamine (2.00%)% by mass8.00TertiaryN-Methyldiethanolamine (7.00%)% by massamineTriisopropanolamine (8.00%)% by massCyclohexyldiethanolamine (0.10%)% by massPOE alkylamine (EO:2) (0.10%)% by massComponentPrimaryMonoisopropanolamine (100.00%)% by mass2.002.002.803.30(X)amine2-Amino-2-methyl-1-propanol% by mass1.301.70(100.00%)SecondaryN-Methylethanolamine% by mass3.20amine(100.00%)Dicyclohexylamine (61.00%)% by mass8.005.00TertiaryN-Methyldicyclohexylamine% by mass8.008.00amine(28.00%)ComponentFatty acidFatty acid mixture% by mass17.5017.5017.5017.5017.50(B)ComponentNonionicPolyoxyalkylene% by mass3.003.003.003.003.00(C)surfactantalkyl etherComponentBase oilParaffinic% by mass57.0056.9056.5058.4056.90(D)mineral oilPAO% by massEster-based% by masssynthetic oilComponentWaterWater% by mass8.008.008.008.008.00(E)OtherMetal deactivatorBenzotriazole% by mass1.001.001.001.001.00additivesOily agentOleyl% by mass2.002.002.002.002.00alcoholAntibacterial1,2-Benzo-% by mass0.200.200.200.200.20agentisothiazolin-3-oneAntifoamingSilicone% by mass0.100.100.100.100.10agentantifoaming agent—Total% by mass100.00100.00100.00100.00100.00Total content of component (A)% by mass0002.008.00Content of component (X) based on 100 partspart by———39041by mass of total amount of component (A)massBase value derived from component (A) / —1.741.741.761.741.74Acid value derived from component (B)Content of component (A1) having% by mass———100.0100.0volatility of 10% or less in totalamount (100% by mass) of component (A)Content of polyalkylene glycol having% by mass00000Mw of 12,000 or less (Y1)Content of water-insoluble compound% by mass00000having polyoxyalkylene group (Y2)EvaluationFume color test—FFFFFitemThermalpH after heating—9.69.69.69.69.6stability testfor 24 hourspH after heating—8.5(*1)8.58.68.8for 168 hoursDecay resistanceTest solution beforeweek45555testthermal deteriorationTest solution afterweek1(*2)112thermal deterioration(*1): Test solution separated before heating time reached 168 hours, thus no pH measurement was possible, and subsequent procedure was not carried out.(*2): Test solution separated due to 48 hours of heating, thus preparation of test solution was not possible, and procedure was terminated without carrying out decay resistance test.TABLE 4Com-Com-Com-Com-Com-par-par-par-par-par-ativeativeativeativeativeExam-Exam-Exam-Exam-Exam-ple 11ple 12ple 13ple 14ple 15CompositionComponentPrimary amine2-(2-Aminoethoxy)ethanol (4.00%)% by massof oil(A)SecondaryDiisopropanolamine (11.00%)% by mass6.00amineDibenzylamine (2.00%)% by massTertiaryN-Methyldiethanolamine (7.00%)% by mass5.205.50amineTriisopropanolamine (8.00%)% by mass9.00Cyclohexyldiethanolamine (0.10%)% by massPOE alkylamine (EO:2) (0.10%)% by mass8.00ComponentPrimaryMonoisopropanolamine (100.00%)% by mass4.20(X)amine2-Amino-2-methyl-1-propanol% by mass(100.00%)SecondaryN-Methylethanolamine% by massamine(100.00%)Dicyclohexylamine (61.00%)% by mass8.008.008.00TertiaryN-Methyldicyclohexylamine% by mass8.00amine(28.00%)ComponentFatty acidFatty acid mixture% by mass17.5017.5017.5017.5017.50(B)ComponentNonionicPolyoxyalkylene% by mass3.003.003.003.003.00(C)surfactantalkyl etherComponentBase oilParaffinic% by mass54.2056.0055.0054.7051.20(D)mineral oilPAO% by massEster-based% by masssynthetic oilComponentWaterWater% by mass8.008.008.008.008.00(E)OtherMetal deactivatorBenzotriazole% by mass1.001.001.001.001.00additivesOily agentOleyl alcohol% by mass2.002.002.002.002.00Antibacterial1,2-Benzo-% by mass0.200.200.200.200.20agentisothiazolin-3-oneAntifoamingSilicone% by mass0.100.100.100.100.10agentantifoaming agent—Total% by mass100.00100.00100.00100.00100.00Total content of component (A)% by mass6.008.005.205.509.00Content of component (X) based on 100 partspart by1335315414589by mass of total amount of component (A)massBase value derived from component (A) / —1.731.751.751.731.75Acid value derived from component (B)Content of component (A1) having% by mass0.0100.0100.0100.0100.0volatility of 10% or less in totalamount (100% by mass) of component (A)Content of polyalkylene glycol having% by mass00000Mw of 12,000 or less (Y1)Content of water-insoluble compound having% by mass00000polyoxyalkylene group (Y2)EvaluationFume color test—FFFAFitemThermalpH after heating—9.59.69.49.49.1stability testfor 24 hourspH after heating—8.8(*1)8.88.88.6for 168 hoursDecay resistanceTest solution beforeweek45333testthermal deteriorationTest solution afterweek1(*2)111thermal deteriorationCom-Com-Com-Com-Com-par-par-par-par-par-ativeativeativeativeativeExam-Exam-Exam-Exam-Exam-ple 16ple 17ple 18ple 19ple 20CompositionComponentPrimary amine2-(2-Aminoethoxy)ethanol (4.00%)% by massof oil(A)SecondaryDiisopropanolamine (11.00%)% by massamineDibenzylamine (2.00%)% by massTertiaryN-Methyldiethanolamine (7.00%)% by massamineTriisopropanolamine (8.00%)% by mass9.60Cyclohexyldiethanolamine (0.10%)% by mass7.608.00POE alkylamine (EO:2) (0.10%)% by massComponentPrimaryMonoisopropanolamine (100.00%)% by mass3.003.00(X)amine2-Amino-2-methyl-1-propanol% by mass(100.00%)SecondaryN-Methylethanolamine% by mass(100.00%)amineDicyclohexylamine (61.00%)% by mass8.008.008.00TertiaryN-Methyldicyclohexylamine% by mass8.008.00amine(28.00%)ComponentFatty acidFatty acid mixture% by mass17.5017.5017.5017.5017.50(B)ComponentNonionicPolyoxyalkylene% by mass3.003.003.003.003.00(C)surfactantalkyl etherComponentBase oilParaffinic% by mass50.6052.6052.20(D)mineral oilPAO% by mass57.20Ester-based% by mass57.20synthetic oilComponentWaterWater% by mass8.008.008.008.008.00(E)OtherMetal deactivatorBenzotriazole% by mass1.001.001.001.001.00additivesOily agentOleyl alcohol% by mass2.002.002.002.002.00Antibacterial1,2-Benzo-% by mass0.200.200.200.200.20agentisothiazolin-3-oneAntifoamingSilicone% by mass0.100.100.100.100.10agentantifoaming agent—Total% by mass100.00100.00100.00100.00100.00Total content of component (A)% by mass9.607.608.0000Content of component (X) based on 100 partspart by83105100——by mass of total amount of component (A)massBase value derived from component (A) / —1.741.751.731.751.75Acid value derived from component (B)Content of component (A1) having% by mass100.0100.0100.0——volatility of 10% or less in totalamount (100% by mass) of component (A)Content of polyalkylene glycol having% by mass00000Mw of 12,000 or less (Y1)Content of water-insoluble compound having% by mass00000polyoxyalkylene group (Y2)EvaluationFume color test—AFAFFitemThermalpH after heating—9.19.29.29.69.6stability testfor 24 hourspH after heating—8.68.68.7(*1)(*1)for 168 hoursDecay resistanceTest solution beforeweek34466testthermal deteriorationTest solution afterweek112(*2)(*2)thermal deterioration(*1): Test solution separated before heating time reached 168 hours, thus no pH measurement was possible, and subsequent procedure was not carried out.(*2): Test solution separated due to 48 hours of heating, thus preparation of test solution was not possible, and procedure was terminated without carrying out decay resistance test.According to the results provided in Table 1 and Table 2, in the water-soluble metalworking oils of Examples 1 to 19, the volatilization of alkaline components was suppressed, and the metalworking fluids prepared from these oils maintained their pH even after being heated and also had good decay resistance. Accordingly, it seems that the metalworking fluids obtained from these water-soluble metalworking oils can maintain their characteristics for a long period of time even in a heated environment.On the other hand, according to Table 3 and Table 4, the water-soluble metalworking oils of Comparative Examples 1 to 20 and the metalworking fluids prepared from these oils exhibited at least disadvantages such as insufficient suppression of the volatilization of alkaline components, a decrease in pH in a heated environment, or impaired decay resistance.

Claims

1: A water-soluble metalworking oil, comprising:two or more amine compounds (A) each having a volatility of 20% or less as calculated from the following formula (i) when heated at 50° C. for 48 hours as component (A), anda fatty acid (B) as component (B),wherein a content of an amine compound (X) not corresponding to the component (A) is less than 5.0 parts by mass based on 100 parts by mass of a total amount of the component (A):Volatility⁢ (%)= ([Mass⁢ of⁢ amine⁢ compound⁢ before⁢ being⁢ heated]-
[Mass⁢ of⁢ amine⁢ compound⁢ after⁢ being⁢ heated⁢ for⁢ 48⁢ hours]) / ⁢
[Mass⁢ of⁢ amine⁢ compound⁢ before⁢ being⁢ heated]×100.Formula⁢ (i)2: The water-soluble metalworking oil according to claim 1, wherein a content of the component (A) is more than 5.0% by mass based on a total amount of the water-soluble metalworking oil.3: The water-soluble metalworking oil according to claim 1, wherein the component (A) comprises at least two amine compounds (A1) each having a volatility of 10% or less.4: The water-soluble metalworking oil according to claim 1, wherein a total content of a polyalkylene glycol having a weight-average molecular weight of 12,000 or less (Y1) and a water-insoluble compound having a polyoxyalkylene group (Y2) is less than 70% by mass based on a total amount of the water-soluble metalworking oil.5: The water-soluble metalworking oil according to claim 4, wherein a content of the polyalkylene glycol having a weight-average molecular weight of 12,000 or less (Y1) is less than 15.0% by mass based on the total amount of the water-soluble metalworking oil.6: The water-soluble metalworking oil according to claim 4, wherein a content of the water-insoluble compound having a polyoxyalkylene group (Y2) is less than 15.0% by mass based on the total amount of the water-soluble metalworking oil.7: The water-soluble metalworking oil according to claim 1, wherein a content of the component (B) is 5.0% by mass or more based on a total amount of the water-soluble metalworking oil.8: The water-soluble metalworking oil according to claim 1, wherein [(A) / (B)], which is a ratio of a base value derived from the component (A) to an acid value derived from the component (B), is 0.50 to 10.0.9: The water-soluble metalworking oil according to claim 1, further comprising a nonionic surfactant (C).10: The water-soluble metalworking oil according to claim 1, further comprising a base oil (D).11: The water-soluble metalworking oil according to claim 1, further comprising water (E).12: A metalworking fluid, comprising:the water-soluble metalworking oil according to claim 1 andwater.13: A metalworking method, comprising:processing a workpiece comprising metal by applying the metalworking fluid according to claim 12.

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