JP2023141499A - Metalworking oil composition - Google Patents

Abstract

To provide a metalworking oil composition with excellent corrosion resistance, lubricity (cutting property), antifoaming properties, and stability.SOLUTION: There is provided a metalworking oil composition that comprises: a mixture (A) of 1 to 5 mass% of a primary alkanolamine selected from the group consisting of aminobutanol, aminohexanol, aminooctanol, and aminododecanol, 2 to 8 mass% of a secondary alkanolamine selected from the group consisting of diethanolamine, diisopropanolamine, and monobutylmonoethanolamine, and 0.5 to 5 mass% of a tertiary alkanolamine selected from the group consisting of triethanolamine, triisopropanolamine, and diethanolmonoisopropanolamine; a total of 8 to 10.5 mass% of a mixture (B) of a dibasic acid, a straight chain fatty acid and a branched saturated fatty acid; 1 to 8 mass% of a branched alcohol (C) having 8 to 26 carbons; 20 to 60 mass% of a paraffinic mineral oil (D); and water (E).SELECTED DRAWING: None

Description

The present invention relates to a water-soluble metal working fluid composition that can be widely applied to metal working such as cutting and grinding, as well as plastic working.

Cutting fluids widely used in the cutting and grinding fields include water-insoluble cutting fluids based on mineral oil, and water-soluble cutting fluids that contain mineral oil, surfactants, organic amines, etc. and are diluted with water. There is an oil agent.
In water-soluble cutting fluids, preservatives are added or amines having a preservative effect are formulated in order to improve the anti-corrosion performance of the oil.
However, in recent years, in order to conserve global resources and prevent deterioration of the global environment, there has been a need to develop cutting fluids that are more environmentally friendly than conventional ones, and that can withstand use for as long as possible. ing.

Conventionally, water-soluble metalworking oils include, for example, water-soluble cutting oil compositions that use fatty acid alkanolamide ethylene oxide adducts, alkylamine ethylene oxide adducts, alicyclic amine ethylene oxide adducts, and fatty acid higher alcohol adducts ( Patent Document 1), a water-soluble grinding oil composition using a benzene compound and a paraoxybenzoic acid ester compound (Patent Document 2), a primary alkanolamine, a carboxylic acid having 6 to 24 carbon atoms, and a specific alkylene diamine (Patent Document 3), water-soluble metal processing fluids using aromatic amines or alicyclic amines (Patent Document 4), primary, secondary, and tertiary alkylamines, aromatic diamine oxyalkylene adducts, Water-soluble cutting and grinding fluid using an alicyclic diamine oxyalkylene adduct (Patent Document 5), water-soluble metal working fluid composition using an unsaturated fatty acid and a heterocyclic compound (Patent Document 6), alkyl having 4 or more carbon atoms A metal working oil composition and metal working method using an amine having a group and an amine having a cyclo ring or a benzene ring (Patent Document 7), an antibacterial water-soluble cutting oil using an alkylene diamine (Patent Document 8), an amino acid as a biocide A metal working fluid using alcohol (Patent Document 9) is known.

However, although these water-soluble metalworking fluids are effective against general bacteria, they are not sufficiently effective against mold and yeast. In addition, those that are effective use compounds containing halogens, polycyclic aromatic compounds, phenolic compounds, or metal salts, and some of them are substances subject to PRTR, so they are harmful to the human body. There are concerns about the impact of

Preservatives and amines have been essential compounds for improving the anti-corrosion performance of oils.

On the other hand, as a means for improving machinability, for example, as a method for improving lubrication, a hot rolling oil and a hot rolling method using a specific palm olein oil (Patent Document 10), A metalworking oil composition having a specific amine value ratio, a processing method using the composition, and metalwork parts manufactured by the metalworking method (Patent Document 11) are known.

However, although these water-soluble metal working fluids are effective in general cutting, they do not satisfy the cutting performance in heavy cutting.

Special Publication No. 6-31388 Special Publication No. 7-37632 Special Publication No. 6-76590 Patent No. 2510233 Japanese Patent Application Publication No. 9-316482 Patent No. 4836341 Patent No. 5255835 Patent No. 5204390 Patent No. 5670882 Patent No. 3320642 Patent No. 6355339

It is an object of the present invention to provide a metalworking fluid composition that has excellent corrosion resistance, lubricity (cutting properties), antifoaming properties, and stability.

The inventors have found that such objects can be achieved by using specific amines, specific fatty acids, specific alcohols, and specific mineral oils in specific ratios. That is, the present invention provides the following metal working fluid composition, metal working fluid, and metal working method:
1. (A) at least one type of primary alkanolamine (A-1), at least one type of secondary alkanolamine (A-2), and at least one type of tertiary alkanolamine (A-3);
(B) At least one dibasic acid (B-1), at least one straight chain fatty acid (B-2), and at least one branched saturated fatty acid (B-3), totaling 8 to 10 .5% by mass,
(C) 1 to 8% by mass of at least one branched alcohol having 8 to 26 carbon atoms;
(D) 20 to 60% by mass of paraffinic mineral oil;
(E) contains water;
(A-1) is at least one selected from the group consisting of aminobutanol, aminohexanol, aminooctanol, and aminododecanol, and the content of (A-1) is 1 to 5% by mass,
(A-2) is at least one selected from the group consisting of diethanolamine, diisopropanolamine, and monobutylmonoethanolamine, and the content of (A-2) is 2 to 8% by mass,
(A-3) is at least one selected from the group consisting of triethanolamine, triisopropanolamine, and diethanolmonoisopropanolamine, and the content of (A-3) is 0.5 to 5% by mass, Metalworking oil composition.
2. (B-1) is at least one selected from the group consisting of sebacic acid, undecanedioic acid, dodecanedioic acid, and 5(or6)-carboxy-4-hexyl-2-cyclohexeneoctanoic acid;
(B-2) is at least one selected from the group consisting of pelargonic acid, lauric acid, myristic acid, palmitic acid, stearic acid, octadecenoic acid, linoleic acid, linolenic acid, 12-hydroxystearic acid, ricinoleic acid, and erucic acid. is a seed,
The metal processing according to 1 above, wherein (B-3) is at least one selected from the group consisting of isononanoic acid, neononanoic acid, isodecanoic acid, neodecanoic acid, isotridecanoic acid, neotridecanoic acid, isostearic acid, and isoarachic acid. Oil composition.
3. The above-mentioned product containing 0.5 to 5% by mass of component (B-1), 2.5 to 5% by mass of component (B-2), and 1 to 4% by mass of component (B-3). 2. The metal working oil composition according to 2.
4. 4. The processing oil composition according to any one of 1 to 3 above, wherein component (D) is a paraffinic mineral oil having a viscosity of 8 to 60 mm ² /s at 40°C.
5. A metalworking fluid prepared by diluting the metalworking fluid composition according to any one of 1 to 4 above with water.
6. A metalworking method comprising using the metalworking oil composition according to any one of 1 to 4 above or the metalworking oil composition according to 5 above.

According to the present invention, it is possible to provide a metalworking fluid composition that has excellent corrosion resistance, lubricity (cutting properties), antifoaming properties, and stability. The metal working oil composition of the present invention also has excellent hard water resistance. The metal working oil composition of the present invention also has excellent rust prevention properties.

[Component (A)]
Component (A) comprises at least one primary alkanolamine (A-1), at least one secondary alkanolamine (A-2), and at least one tertiary alkanolamine (A-3). It is a mixture of Component (A) contributes to stock stability, rust prevention, and rot resistance.
Examples of the primary alkanolamine (A-1) include aminobutanol, aminohexanol, aminooctanol, aminododecanol, 2-(2-aminoethoxy)ethanol, and monoisopropanolamine. These may be used alone or in combination of two or more. Among these, aminobutanol, aminohexanol, aminooctanol, and aminododecanol are preferred.
Examples of the secondary alkanolamine (A-2) include diisopropanolamine, 2-(butylamino)ethanol, diethanolamine, methylethanolamine, and ethylethanolamine. These may be used alone or in combination of two or more. Among these, diethanolamine, diisopropanolamine, and monobutylmonoethanolamine are preferred.
Tertiary alkanolamines (A-3) include N-methyldiethanolamine, triethanolamine, triisopropanolamine, diethanolmonoisopropanolamine, butyldiethanolamine, dibutylethanolamine, dimethylethanolamine, diethylethanolamine, dimethylisopropanolamine, diethyl Examples include isopropanolamine. These may be used alone or in combination of two or more. Among these, triethanolamine, triisopropanolamine, and diethanolmonoisopropanolamine are preferred.

The content of component (A-1) is preferably 1 to 5% by weight, more preferably 2 to 5% by weight, based on the total weight of the composition. When the content is 1% by mass or more, sufficient rot resistance can be obtained. When the amount is 5% by mass or less, emulsion stability is good.

The content of component (A-2) is preferably 2 to 8% by weight, more preferably 3 to 7% by weight, based on the total weight of the composition. When the content is 2% by mass or more, good stability of the stock solution can be exhibited. When the content is 8% by mass or less, cutting performance can be sufficiently improved.

The content of component (A-3) is preferably 0.5 to 5% by weight, more preferably 1 to 4% by weight, based on the total weight of the composition. When the content is 0.5% by mass or more, sufficient rust prevention properties can be exhibited. When the content is 5% by mass or less, good stability of the stock solution can be exhibited.
The total amount of components (A-1), (A-2) and (A-3) is preferably 10 to 18% by weight, based on the total weight of the composition of the present invention, and 11 to 15.5% by weight. % is more preferable. By containing component (A) in such a range, good emulsion stability and good stock solution stability can be maintained.

[Component (B)]
Component (B) is a mixture of at least one dibasic acid (B-1), at least one straight chain fatty acid (B-2), and at least one branched saturated fatty acid (B-3). The total amount thereof is 8 to 10.5% by weight, preferably 8.5 to 10% by weight, based on the total weight of the composition of the present invention. By containing component (B) in such a range, emulsion stability, rust prevention properties, antifoaming properties, and lubricity can be satisfied. Component (B) particularly contributes to emulsion stability, rust prevention properties, and antifoaming properties.
As the dibasic acid of component (B-1), succinic acid, adipic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, 5(or6)-carboxy-4-hexyl-2-cyclohexeneoctanoic acid (for example, , manufactured by Ingevity, "DIACID1550"), etc. These may be used alone or in combination of two or more. Among these, sebacic acid, undecanedioic acid, dodecanedioic acid, and 5(or6)-carboxy-4-hexyl-2-cyclohexeneoctanoic acid are preferred.
The straight chain fatty acids of component (B-2) include caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, pentadecyl acid, palmitic acid, stearic acid, arachidonic acid, behenic acid, and lignocerin. Acid, cerotic acid, montanic acid, melisic acid, palmitoleic acid, margaric acid, vaccenic acid, oleic acid, linoleic acid, linolenic acid, eleostearic acid, eicosadienoic acid, mead acid, erucic acid, nervonic acid, elaidic acid, arachidonic acid Examples include eicosapentaenoic acid, docosahexaenoic acid, 12-hydroxystearic acid, and ricinoleic acid. These may be used alone or in combination of two or more. Among these, pelargonic acid, lauric acid, myristic acid, palmitic acid, stearic acid, octadecenoic acid, linoleic acid, linolenic acid, 12-hydroxystearic acid, ricinoleic acid and erucic acid are preferred. More preferred are pelargonic acid, lauric acid, oleic acid, ricinoleic acid and erucic acid.
Examples of the branched fatty acid of component (B-3) include isononanoic acid, neononanoic acid, isodecanoic acid, neodecanoic acid, isotridecanoic acid, neotridecanoic acid, isostearic acid, isoarachic acid, and the like. These may be used alone or in combination of two or more. Among these, neodecanoic acid, isotridecanoic acid, isostearic acid, or a mixture of two or more thereof is preferred. More preferred is neodecanoic acid, isostearic acid, or a mixture thereof. Most preferred is isostearic acid alone or a mixture of neodecanoic acid and isostearic acid.

The content of component (B-1) is preferably 0.5 to 5% by weight, more preferably 2 to 4% by weight, based on the total weight of the composition. When the content is 0.5% by mass or more, sufficient rust prevention properties can be exhibited. When the content is 5% by mass or less, hard water resistance can be sufficiently improved.

The content of component (B-2) is preferably 2.5 to 5% by weight, more preferably 3 to 4% by weight, based on the total weight of the composition. When the content is 2.5% by mass or more, good emulsion stability can be exhibited. When the content is 5% by mass or less, antifoaming performance can be sufficiently exhibited.

The content of component (B-3) is preferably 1 to 4% by weight, more preferably 1.5 to 3% by weight, based on the total weight of the composition. Within this range, a satisfactory level of defoaming performance can be exhibited.

[Component (C)]
Component (C) is at least one branched alcohol having 8 to 26 carbon atoms. Component (C) contributes to the stability of the stock solution, especially at low temperatures. Component (C) includes caprylic alcohol, nonanol, decanol, undecanol, lauryl alcohol, tridecanol, tetradecanol, pentadecanol, myristyl alcohol, cetyl alcohol, stearyl alcohol, oleyl alcohol, linolyl alcohol, icosanol, henicosanol, tetra Examples include branched alcohols such as cosanol and triacontanol. Among these, isotridecanol, isotetradecanol, isopentadecanol, and isotetracosanol are preferred, and among the isotetracosanols, 2-decyl-1-tetradecanol is particularly preferred.

The content of component (C) is 1 to 8% by weight, preferably 3 to 7% by weight, based on the total weight of the composition. When the content is 1% by mass or more, the stability of the stock solution at low temperatures can be improved. When the content is 8% by mass or less, good hard water resistance can be exhibited.

[Component (D)]
Component (D) is a paraffinic mineral oil. Component (D) particularly contributes to lubricity. Component (D) is preferably a paraffinic mineral oil having a kinematic viscosity of 8 to 60 mm ² /s at 40°C. In addition, in this specification, kinematic viscosity can be measured according to JIS K 2283.

The content of component (D) is 20 to 60% by weight, preferably 30 to 40% by weight, based on the total weight of the composition. When the content is 20% by mass or more, good lubricity can be exhibited. When the content is 60% by mass or less, the emulsion stability of the diluted liquid can be improved.

[Component (E)]
Component (E) is water. Component (E) contributes to stock solution stability. The content of component (E) is the remainder, and specifically, it is preferably 5 to 40% by mass, more preferably 10 to 30% by mass.

The metalworking oil composition of the present invention contains a castor fatty acid polycondensate, if necessary. Particularly preferred are dimers to hexamers. The acid value (measured according to JIS K 2501) of the castor fatty acid polycondensate is preferably 30 to 100. The dimer mainly acts as an emulsifier, and the tetramer and hexamer mainly act as stock solution stabilizers. Its content is preferably 3 to 20% by weight, more preferably 5 to 15% by weight, based on the total weight of the composition. When the content is within this range, the emulsification of the diluted solution and the stability of the stock solution are excellent.

The metal working oil composition of the present invention contains a lubricating oil as a lubricating aid, if necessary. Examples of the lubricating aid include synthetic ester oils, polyol esters, alkylbenzenes, natural oils and fats, polyglycols, poly-α-olefins, and the like. These oils are not limited to single oils, and may be used as a blend of multiple types. Preferably, synthetic ester oils and natural oils and fats are used. As the synthetic ester oil, 2-ethylhexyl palmitate, 2-ethylhexyl stearate, or 2-ethylhexyl oleate is preferred.

The content of the lubricating oil as a lubricating aid is preferably 3 to 20% by mass, more preferably 5 to 15% by mass, based on the total mass of the metalworking fluid composition of the present invention. When the content is within this range, the lubricity is excellent.

The metalworking oil composition of the present invention contains a surfactant, if necessary. The surfactant may be, for example, an anionic surfactant, a cationic surfactant, a nonionic surfactant, or an amphoteric surfactant. Anionic surfactants and nonionic surfactants are preferred. As the anionic surfactant, ether carboxylic acids such as lauryl ether carboxylic acid, which is obtained by adding acetic acid to the terminal of lauryl alcohol EO adduct, and oleyl ether carboxylic acid, which is obtained by adding acetic acid to the terminal of oleyl alcohol EO adduct, are preferable. The number of moles of EO added to the ether carboxylic acid is preferably 2 to 10.
The nonionic surfactant preferably has an HLB of 4 to 14 expressed by Griffin's formula. For example, polyoxyalkylene alkyl (alkenyl) ethers (weight average molecular weight of about 700 to 2,000) such as polyoxypropylene monobutyl ether and polyoxyethylene oleyl ether; alkylene oxides of higher amines such as laurylamine EO adducts and cocoa amine EO adducts. Adducts: Examples include alkylene oxide adducts of higher alcohols such as C12-14 alcohol EO and PO adducts. The surfactants may be used alone or in combination of two or more.
The content of the surfactant is preferably 0.2 to 5% by weight, more preferably 0.5 to 2% by weight, based on the total weight of the composition. If the content is within this range, the emulsion stability of the diluted solution and the stability of the stock solution will be excellent.

The metal working oil composition of the present invention may contain a fatty acid such as lauryl succinic acid or stearyl succinic acid, a sulfonate such as sodium petroleum sulfonate, a carboxylic acid amide, or the like as a rust preventive agent, if necessary.
The content of the rust preventive agent is preferably 0 to 20% by mass, more preferably 1 to 10% by mass, based on the total mass of the composition.

Further, the metal working fluid composition of the present invention may contain a silicone antifoaming agent, an alcohol antifoaming agent, a benzotriazole metal anticorrosive agent, etc. as necessary.
The content of the antifoaming agent and the metal anticorrosive agent is preferably 0.05 to 2% by mass, more preferably 0.1 to 1% by mass, respectively, based on the total mass of the composition.

Furthermore, the metalworking oil composition of the present invention may optionally contain preservatives such as benzisothiazoline, 1,2-benzisothiazolin-3-one, butylbenzisothiazoline, metal pyrithione salts (e.g., sodium omazine, zinc pyrithione), lauryl Alkylamines such as amines and oleylamines may be included as preservatives or antibacterial agents.
The content of the preservative or fungus inhibitor is preferably 0.1 to 5% by weight, more preferably 0.2 to 2% by weight, based on the total weight of the composition.

The pH (25° C.) of the metalworking oil composition of the present invention is preferably 7.0 to 11, more preferably 8.5 to 11, in a solution obtained by diluting the stock solution to 5% by mass with pure water. When the pH is 7.0 or higher, satisfactory antiseptic properties can be obtained. When the pH is 11 or less, skin irritation can be kept low. As a pH adjuster, amines other than component (A), such as amines having an alicyclic group such as dicyclohexylamine, 1,3 bisaminocyclohexane, and cyclohexylpropyl diamine, their EO adducts, aromatic substances such as metaxylene diamine, etc. Amines having a group cyclic group and acids such as lactic acid, malic acid, maleic acid, succinic acid, tartaric acid, citric acid, and boric acid can be used.
The metalworking oil composition of the present invention is generally used after being diluted with water to a concentration of 0.5% by mass or more.

Compositions of Examples and Comparative Examples having the compositions shown in Table 1 were prepared.
<Evaluation method>
(1) Rot resistance To 100 ml of a solution diluted to 3% by weight of the composition of the example or comparative example, 3% by mass of the following spoilage solution was added, and after culturing with shaking at 30°C and 150 rpm for 28 days, the number of viable bacteria was (cells/ml) was measured.
Putrid fluid: Emulsion-type cutting fluid that has rotted and deteriorated 50% by mass
Trypto soy medium 25% by mass
Glucose peptone medium 25% by mass
The above was aerated for 24 hours, and the activated putrefaction liquid was evaluated for the number or degree of contamination of general bacteria, mold, yeast, and anaerobic bacteria using a San-ai Biochecker (manufactured by San-Ai Sekiyu Co., Ltd.). For general bacteria and yeast, the number of bacteria in 1 mL was evaluated on an 8-level scale: no, 10 ³ or less, 10 ³ , 10 ⁴ , 10 ⁵ , 10 ⁶ , 10 ⁷ , and 10 ⁷ or more. . Regarding mold and anaerobic bacteria, the degree of contamination was evaluated in four stages: no, mild, moderate, and severe.
Judgment criteria: For mold, yeast, and anaerobic bacteria, no is considered a pass.
For general bacteria, 10 ³ or less/ml is considered a pass.

(2) Lubricity (cutting properties)
M6 tap machining was performed using the following workpiece material under the following conditions, and the cutting resistance received during machining was measured.
Work tool: Roll tap (OSG B-NRT RH7 M6 x 1.0)
Work material: Aluminum alloy (AC8B-T6, 300 x 200 x 30 mm)
Cutting speed: 10m/min
Pilot hole: 5.48mm reamed, blind hole Cutting length: 20mm
Concentration: Dilute the stock solution to 5% by mass with water Number of N: 5
Test oil: Composition of Example or Comparative Example diluted to 5% by mass with water Lubricating method: Fill pilot hole with test oil Evaluation method: Measure cutting resistance (torque [N・m]) Judgment criteria: Cutting A torque of 2.9 N·m or less is considered a pass.

(3) Defoaming property Evaluation was performed using a 3L gear pump circulation test method.
Liquid volume: 3L
Flow rate: 17.4L/min
Discharge pressure: 0.6kgf/ ^cm2
Nozzle diameter: φ6.5mm
Container: diameter 220mm, height 300mm
Dilution water: Adjusted water with Ca: 5 ppm (1.8375 mg of calcium chloride dihydrate was diluted with distilled water to make 1 L)
Concentration: Dilute the stock solution to 5% by mass with adjusted water containing Ca: 5ppm Solution temperature: 25°C
Judgment criteria: A maximum foam height of 200 mm or less is considered acceptable.

(4) Stability of the stock solution Put the composition of the example or comparative example in a candle bottle, leave it for 168 hours in a constant temperature bath at -5°C, 25°C, and 50°C, and check the state of the stock solution when taken out. do.
Judgment criteria: Pass if there is no change in appearance such as separation or solidification.

(5) Emulsion stability (stability of diluted solution)
A composition of an example or a comparative example is diluted with pure water to a concentration of 5% by mass, and 100 mL of the diluted composition is placed in a graduated cylinder with a stopper, and changes in appearance are observed after one day at 25°C.
Judgment criteria: Pass if there is no emulsification defect.

(6) Hard water resistance Prepare water in which calcium chloride dihydrate is dissolved in pure water so that the calcium concentration is 100 ppm, and add 5 mass of the composition of Example or Comparative Example to this water. %, put it in a mayonnaise bottle, seal it, and check the appearance change after 1 day at 25°C.
Judgment criteria: Pass if there is no significant scum generation or oil separation.

(7) Rust prevention property Weigh 20g of dry-cut FC200 chips in a petri dish (diameter 60mm, height 15mm), add 25ml of each sample (diluent), let stand for 10 minutes, then decant the material, and cover with a lid. and leave it at room temperature for 24 hours. The state of rust occurrence after 24 hours was visually observed.
Evaluation: No rusting: ○, Approximately 10% rusting: □, Approximately 50% rusting: △, Fully rusting: ×

Claims (6)

(A) at least one type of primary alkanolamine (A-1), at least one type of secondary alkanolamine (A-2), and at least one type of tertiary alkanolamine (A-3);
(B) At least one dibasic acid (B-1), at least one straight chain fatty acid (B-2), and at least one branched saturated fatty acid (B-3), totaling 8 to 10 .5% by mass,
(C) 1 to 8% by mass of at least one branched alcohol having 8 to 26 carbon atoms;
(D) 20 to 60% by mass of paraffinic mineral oil;
(E) contains water;
(A-1) is at least one selected from the group consisting of aminobutanol, aminohexanol, aminooctanol, and aminododecanol, and the content of (A-1) is 1 to 5% by mass,
(A-2) is at least one selected from the group consisting of diethanolamine, diisopropanolamine, and monobutylmonoethanolamine, and the content of (A-2) is 2 to 8% by mass,
(A-3) is at least one selected from the group consisting of triethanolamine, triisopropanolamine, and diethanolmonoisopropanolamine, and the content of (A-3) is 0.5 to 5% by mass, Metalworking oil composition. (B-1) is at least one selected from the group consisting of sebacic acid, undecanedioic acid, dodecanedioic acid, and 5(or6)-carboxy-4-hexyl-2-cyclohexeneoctanoic acid;
(B-2) is at least one selected from the group consisting of pelargonic acid, lauric acid, myristic acid, palmitic acid, stearic acid, octadecenoic acid, linoleic acid, linolenic acid, 12-hydroxystearic acid, ricinoleic acid, and erucic acid. is a seed,
The metal according to claim 1, wherein (B-3) is at least one selected from the group consisting of isononanoic acid, neononanoic acid, isodecanoic acid, neodecanoic acid, isotridecanoic acid, neotridecanoic acid, isostearic acid, and isoarachic acid. Processing oil composition. A claim containing 0.5 to 5% by mass of component (B-1), 2.5 to 5% by mass of component (B-2), and 1 to 4% by mass of component (B-3). Item 2. The metal working oil composition according to item 2. The processing oil composition according to any one of claims 1 to 3, wherein component (D) is a paraffinic mineral oil having a viscosity of 8 to 60 mm ² /s at 40°C. A metalworking fluid prepared by diluting the metalworking fluid composition according to any one of claims 1 to 4 with water. A metalworking method comprising using the metalworking oil composition according to any one of claims 1 to 4 or the metalworking oil composition according to claim 5.