Water-soluble metalworking oil, metalworking fluid, metalworking method, and method for improving dispersibility of water-soluble metalworking oil

Abstract

To provide, e.g., a metalworking oil with improved dispersibility in water.SOLUTION: The water-soluble metalworking oil contains a hydroxyl compound represented by general formula (1), water, a base oil, and a surfactant.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a water-soluble metalworking oil, a metalworking fluid, a metalworking method, and a method for improving the dispersibility of a water-soluble metalworking oil.

Background Art

[0002] In the field of metalworking such as cutting and grinding, water-soluble metalworking oils are used. The water-soluble metalworking oil is often used as a metalworking fluid (diluted solution) by diluting the stock solution of the metalworking oil with water. Techniques for improving the dispersibility of such a metalworking oil stock solution in water have been proposed.

[0003] For example, Patent Document 1 discloses a water-soluble metalworking oil composition that reduces tool friction and lengthens tool life by blending a polymer of a hydroxy unsaturated fatty acid and a tertiary amine in a relatively high blending amount, and improves handleability by enhancing dispersibility in water.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the water-soluble metalworking oil composition described in Patent Document 1 has room for improvement in terms of dispersibility. A decrease in dispersibility in water causes deterioration of handleability when diluting the stock solution with water, and equipment fouling due to adhesion of emulsification defects in the apparatus in which the metalworking oil is used.

[0006] The main object of the present disclosure is to provide a metalworking oil having improved dispersibility in water.

Means for Solving the Problems

[0007] Aspects of the present disclosure for solving the above problems are as follows.

[0008] [1] A water-soluble metalworking fluid containing a hydroxy compound represented by the following general formula (1), water, a base oil, and a surfactant. Water-soluble metalworking fluid.

[0009] [Chemical formula]

[0010] [In the formula, R 1 is an optionally substituted branched or cyclic hydrocarbon group having 6 to 8 carbon atoms or a linear unsaturated hydrocarbon group, R 2 is an alkylene group having 2 or 3 carbon atoms, n is an integer from 0 to 2.] [2] The water-soluble metalworking fluid according to [1], wherein in the general formula (1), R 1 is an aryl group. [3] The water-soluble metalworking fluid according to [1] or [2], wherein in the general formula (1), the alkylene group in R 2 has 2 carbon atoms. [4] The water-soluble metalworking fluid according to any one of [1] to [3], wherein in the general formula (1), n is 1 or 2. [5] The water-soluble metalworking fluid according to any one of [1] to [4], wherein the content of the hydroxy compound is 1.5% by mass or more and 10% by mass or less. [6] The water-soluble metalworking fluid according to any one of [1] to [5], wherein the mass ratio (hydroxy compound / surfactant) of the content of the hydroxy compound to the content of the surfactant is 0.05 or more and 1.0 or less. [7] The water-soluble metalworking fluid according to any one of [1] to [6], wherein the surfactant is at least one selected from the group consisting of a nonionic surfactant and an anionic surfactant. [8] A metalworking fluid obtained by diluting the water-soluble metalworking oil agent according to any one of [1] to [7] with water. [9] A metalworking method for processing a workpiece made of metal using a metalworking fluid obtained by diluting the water-soluble metalworking oil agent according to any one of [1] to [7] with water.

[10] A method for improving the dispersibility of a water-soluble metalworking oil agent, which includes a step of mixing a hydroxy compound represented by the following general formula (1), water, a base oil, and a surfactant.

[0011] [Chemical formula]

[0012] [In the formula, R 1 is an optionally substituted branched or cyclic hydrocarbon group or a linear unsaturated hydrocarbon group having 6 to 8 carbon atoms, R 2 is an alkylene group having 2 or 3 carbon atoms, n is an integer from 0 to 2. ] [Advantages of the Invention]

[0013] According to the present disclosure, it is possible to provide a metalworking oil agent or the like with improved dispersibility in water. [Brief Description of the Drawings]

[0014]

Figure 1

[0015] Hereinafter, preferred embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments. The elements listed below can be arbitrarily combined, and the scope of the present invention is intended to include all modifications within the scope of the claims and the scope equivalent to the claims. In addition, in this specification, the upper and lower limit values exemplified for a numerical range can be arbitrarily combined to form a new numerical range. For example, when "A or more and B or less" and "C or more and D or less" are described, ranges such as "A or more and D or less" and "C or more and B or less" may also be included in the numerical range.

[0016] In this specification, when defining the number of carbon atoms of a certain group, unless otherwise specified, this number of carbon atoms means the total number of carbon atoms of the entire group. That is, when this group is in a form having a substituent, it means the total number of carbon atoms including this substituent.

[0017] [Metalworking fluid] The metalworking fluid of this embodiment contains a hydroxy compound represented by the following general formula (1) (hereinafter, also simply referred to as a hydroxy compound), water, a base oil, and a surfactant.

[0018] [Chemical formula]

[0019] [In the formula, R 1 is an optionally substituted branched or cyclic hydrocarbon group or linear unsaturated hydrocarbon group having 6 to 8 carbon atoms, R 2 is an alkylene group having 2 or 3 carbon atoms, n is an integer from 0 to 2. ]

[0020] When the metalworking fluid is made into a metalworking liquid (diluted liquid) by using the metalworking fluid as a stock solution and diluting it with water, the dispersibility of the stock solution with respect to water can be improved, and the generation of aggregates (suspended matter) can be suppressed. In this specification, the dispersibility with respect to water means the property that the particles in the metalworking fluid are dispersed in water without aggregating.

[0021] The metalworking fluid of the present embodiment contains a hydroxy compound to improve its water dispersibility. The hydroxy compound functions as a dispersant. Although the mechanism by which the metalworking fluid of the present disclosure has excellent water dispersibility is not clear, it is presumed as follows.

[0022] It is considered that the undiluted oil containing water, base oil, and surfactant has a lamellar structure in which water and base oil are microscopically mixed and overlapped in layers, and has fluidity. Surfactant is adsorbed on the water-oil interface. The surfactant aligns with the hydrophilic part in the water layer direction and the lipophilic part in the oil layer direction. As the emulsification process during water dilution of the undiluted oil, shear force acting on the dilution liquid causes fluctuations at the water-oil interface, and the oil component gradually becomes round at the oil interface, and is divided from the constricted part to form oil droplets, generating an O / W emulsion. The surfactants adsorbed on the water-oil interface interact with each other, and the stronger the interaction acting between the adsorbed molecules, the stronger the action as the resistance to the deformation of the water-oil interface, and the more difficult it is to form an O / W emulsion. Therefore, it is presumed that by weakening the interaction acting between the adsorbed molecules, the formation of the O / W emulsion becomes easier, and the dispersibility and dilution property of the undiluted oil can be improved.

[0023] The hydrophobic group constituting the hydroxy compound has a bulky structure such as a cyclic structure, a branched structure, or a linear unsaturated structure, which is bulkier than a linear saturated structure. When the hydroxy compound having this bulky structure adsorbs on the water-oil interface, the intermolecular distance of the adsorbed molecules is expanded compared to the case where only the compound having a linear saturated structure adsorbs on the water-oil interface. As a result, it is presumed that the interaction acting between adjacent molecules on the hydrophobic group side can be weakened, the dispersibility of the undiluted oil is improved, and it becomes easier to be emulsified.

[0024] In addition, the water dispersibility is further improved by weakening the interaction of the hydroxy compound acting on the hydrophilic group side. For example, in the case of a metalworking fluid containing a nonionic surfactant in which hydrogen bonds act between hydrophilic groups via water molecules, such as a polyoxyalkylene chain, and a hydroxy compound having a hydrocarbon group with a high affinity for the polyoxyalkylene chain, such as an aryl group, a part of the hydroxy compound penetrates into the region where the polyoxyalkylene chains are densely present on the hydrophilic group side. When the hydroxy compound penetrates into the hydrophilic group side, the network of water molecules on the hydrophilic group side is disrupted, and the interaction (hydrogen bond) on the hydrophilic group side acting as the resistance to the deformation of the water-oil interface can be weakened. As a result, it is presumed that the dispersibility of the undiluted oil agent is improved and it becomes easier to be emulsified.

[0025] In the present embodiment, in formula (1), R 1 is a branched or cyclic hydrocarbon group having 6 to 8 carbon atoms or a linear unsaturated hydrocarbon group. R 1 may have a substituent.

[0026] In this specification, the "hydrocarbon group" means a group obtained by removing one or more hydrogen atoms from a hydrocarbon having the specified number of carbon atoms. The hydrocarbon group may be substituted with one or more substituents, but is preferably unsubstituted. The substituents are not particularly limited, and examples thereof include alkyl groups having 1 to 3 carbon atoms (methyl group, ethyl group, propyl group, etc.).

[0027] R 1 's hydrocarbon group is preferably branched or cyclic, more preferably cyclic. The branched or cyclic hydrocarbon group may be either saturated or unsaturated. The cyclic hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and is preferably an aromatic hydrocarbon group. The cyclic hydrocarbon group may be a polycyclic group or a monocyclic group.

[0028] In formula (1), R 1Examples of the branched, cyclic or linear unsaturated hydrocarbon group, or the branched or cyclic saturated hydrocarbon group include a branched alkyl group, an alkenyl group, an alkenylene group, an aryl group, a cycloalkyl group, a cycloalkenyl group, a cycloalkylene group, a cycloalkynyl group and the like. The "alkenyl" and "alkenylene" are not particularly limited, and examples thereof include a monoene, a diene, a triene and the like. From the viewpoint of water dispersibility, the hydrocarbon group is preferably a branched alkyl group or an aryl group, and more preferably an aryl group.

[0029] R 1 Examples of the hydrocarbon group having 6 to 8 carbon atoms for R include an ethylbutyl group, a methylpentyl group, a dimethylbutyl group, a methylhexyl group, an ethylpentyl group, a dimethylpentyl group, a methylheptyl group, an ethylhexyl group, a dimethylhexyl group, a phenyl group, a benzyl group, a dimethylphenyl group, a cyclohexyl group, a cycloheptyl group, a cyclohexenyl group and the like. Preferably, they are an ethylhexyl group, a phenyl group and a benzyl group.

[0030] R 1 From the viewpoint of water dispersibility, the number of carbon atoms of the hydrocarbon group for R is preferably 7.

[0031] In formula (1), R 2 is an unsubstituted alkylene group having 2 or 3 carbon atoms, and from the viewpoint of water dispersibility, it is preferably an alkylene group having 2 carbon atoms. Examples of R 2 include an ethylene group (-CH 2 CH 2 -), a propylene group (-CH 2 CH 2 CH 2 -), -CH(CH 3 )-CH 2 -, or -CH 2 CH(CH 3 )-), etc., and preferably an ethylene group.

[0032] In formula (1), n is an integer of 0 to 2. From the viewpoint of water dispersibility, preferably n is 0 or 1, and more preferably 1.

[0033] In one embodiment, in formula (1), for the hydroxy compound, R 1 is a cyclic hydrocarbon group having 6 or 7 carbon atoms, R 2 is an alkylene group having 2 or 3 carbon atoms, and n is 0 or 1.

[0034] In one embodiment, in formula (1), for the hydroxy compound, R 1 is a cyclic hydrocarbon group having 7 carbon atoms, R 2 is an alkylene group having 2 carbon atoms, and n is 0 or 1.

[0035] In one embodiment, in formula (1), for the hydroxy compound, R 1 is a branched saturated hydrocarbon group having 8 carbon atoms, R 2 is an alkylene group having 2 carbon atoms, and n is an integer from 0 to 2.

[0036] The hydroxy compound can be obtained by a known synthesis method. The hydroxy compound may be used alone or in combination of two or more.

[0037] Examples of the hydroxy compound include benzyl alcohol, an ethylene oxide (hereinafter also referred to as EO) adduct of benzyl alcohol (1 mol addition), 2-phenoxyethanol, 2-phenoxyisopropanol, 2-ethylhexanol, monoethylene glycol mono-2-ethylhexyl ether, diethylene glycol, mono-2-ethylhexyl ether, and the like.

[0038] From the viewpoints of water dispersibility and emulsion stability in the water-soluble metal working fluid, the hydroxy compound is preferably 1.5% by mass or more and 10% by mass or less, more preferably 1.8% by mass or more and 9% by mass or less, still more preferably 2.0% by mass or more and 8% by mass or less, even more preferably 2.5% by mass or more and 7% by mass or less, and even more preferably 3.5% by mass or more and 6% by mass or less. When two or more are used in combination, the content means the total amount.

[0039] The water-soluble metalworking fluid of the embodiment contains water. Examples of the water include tap water, industrial water, ion-exchanged water, distilled water, sterilized purified water, etc., and it may be hard water or soft water. The water may be used alone or in combination of two or more.

[0040] From the viewpoints of processability and water dispersibility in the water-soluble metalworking fluid, the water content is preferably 1% by mass or more and 15% by mass or less, more preferably 2% by mass or more and 10% by mass or less, still more preferably 3% by mass or more and 8% by mass or less, and even more preferably 5% by mass or more and 7% by mass or less. When two or more are used in combination, the content means the total amount.

[0041] In the water-soluble metalworking fluid of the embodiment, the mass ratio of the content of the hydroxy compound to the water content (hydroxy compound / water) is preferably 0.05 or more and 3.0 or less, more preferably 0.1 or more and 2.0 or less, still more preferably 0.2 or more and 1.5 or less, and even more preferably 0.4 or more and 1.0 or less from the viewpoint of water dispersibility.

[0042] The water-soluble metalworking oil agent of the embodiment contains a base oil. Examples of the base oil include mineral oil, synthetic oil, animal and vegetable oils and fats, etc., preferably mineral oil and synthetic oil. Examples of the mineral oil include spindle oil, machine oil, cylinder oil, paraffin oil, gear oil, etc., preferably paraffin oil. Examples of the synthetic oil include synthetic oils such as hydrocarbon-based synthetic oil, ester-based synthetic oil, ether-based synthetic oil, etc., preferably ester-based synthetic oil. Examples of the ester-based synthetic oil include esters of carboxylic acid (for example, having 10 to 30 carbon atoms, preferably 12 to 28 carbon atoms, more preferably 15 to 25 carbon atoms) and alcohol (for example, having 1 to 30 carbon atoms, preferably 1 to 25 carbon atoms, more preferably 1 to 20 carbon atoms). The above alcohol may be any of primary, secondary and tertiary alcohols, and may be any of monoalcohol, dialcohol, trialcohol and tetraalcohol. Examples of the ester-based synthetic oil include methyl oleate, 2-ethylhexyl oleate, neopentyl glycol dioleate, trimethylolpropane trioleate, pentaerythritol tetraoleate, etc., preferably 2-ethylhexyl oleate. Examples of the animal and vegetable oils and fats include animal oils and fats (such as lard, beef tallow, fish oil, etc.), vegetable oils and fats (such as rapeseed oil, soybean oil, palm oil, etc.), hydrogenated products thereof, etc. The base oil may be used alone or in combination of two or more.

[0043] From the viewpoints of processability and water dispersibility, the content of the base oil in the water-soluble metalworking oil agent is preferably 0.1% by mass or more and 80% by mass or less, more preferably 5% by mass or more and 77% by mass or less, still more preferably 10% by mass or more and 75% by mass or less, even more preferably 30% by mass or more and 70% by mass or less, and even more preferably 60% by mass or more and 67% by mass or less. When two or more are used in combination, the content means the total amount.

[0044] In the water-soluble metalworking oil of the embodiment, the mass ratio of the content of the hydroxy compound to the content of the base oil (hydroxy compound / base oil) is preferably 0.005 or more and 1.0 or less, more preferably 0.01 or more and 0.5 or less, still more preferably 0.02 or more and 0.3 or less, and even more preferably 0.04 or more and 0.1 or less from the viewpoint of water dispersibility.

[0045] The water-soluble metalworking oil of the embodiment contains a surfactant. The surfactant has a function of improving the liquid stability of the oil agent stock solution and the emulsion-type metalworking fluid. Examples of the surfactant include nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, etc., and nonionic surfactants and anionic surfactants are preferred.

[0046] Examples of nonionic surfactants include ethers, esters, amines, amides, etc. Examples of ethers include alkyl ethers, polyoxyalkylene ethers, polyoxyalkylene alkyl ethers, etc., and polyoxyalkylene alkyl ethers are preferred. Examples of esters include glycerin fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxysorbitol fatty acid esters, etc., and sorbitan fatty acid esters are preferred. Examples of amines include polyoxyalkylene alkylamines, EO adducts of organic amines, etc., and EO adducts of organic amines (for example, 1 to 20 moles) are preferred. Examples of amides include coconut oil fatty acid diethanolamide, oleic acid diethanolamide, etc. Preferred nonionic surfactants are polyoxyalkylene lauryl ether, sorbitan monooleate, and EO adduct of laurylamine.

[0047] Examples of the anionic surfactant include polyoxyalkylene alkyl ether carboxylic acid, polyoxyalkylene alkyl ether phosphoric acid, alkylbenzene sulfonic acid, α-olefin sulfonic acid, and salts thereof, and an alkylbenzene sulfonate is preferable. The anionic surfactant is preferably a sodium sulfonate.

[0048] Examples of the cationic surfactant include quaternary ammonium salts (such as alkyltrimethylammonium salts, dialkyldimethylammonium salts, and alkyldimethylbenzylammonium salts). Examples of the amphoteric surfactant include alkyl betaines as betaine-based surfactants. The surfactant may be used alone or in combination of two or more.

[0049] From the viewpoints of liquid stability and water dispersibility in the water-soluble metal working oil, the content of the surfactant is preferably 0.1% by mass or more and 40% by mass or less, more preferably 1% by mass or more and 30% by mass or less, still more preferably 5% by mass or more and 20% by mass or less, even more preferably 10% by mass or more and 17% by mass or less, and even more preferably 12% by mass or more and 16% by mass or less. When two or more are used in combination, the content means the total amount.

[0050] In the water-soluble metal working oil of the embodiment, the mass ratio of the content of the hydroxy compound to the content of the surfactant (hydroxy compound / surfactant) is preferably 0.01 or more and 2.0 or less, more preferably 0.05 or more and 1.5 or less, still more preferably 0.1 or more and 1.0 or less, and even more preferably 0.2 or more and 0.4 or less from the viewpoint of water dispersibility.

[0051] In addition to the above essential components, the water-soluble metal working oil of the embodiment can contain various additives, etc. as necessary within a range not interfering with the effects of the present invention. Examples of the additives include rust inhibitors, metal corrosion inhibitors, fatty acids, preservatives, defoamers, and the like.

[0052] Examples of the rust inhibitor include organic amines such as alkanolamines. Examples of the organic amines include primary alkanolamines (monoethanolamine, monoisopropanolamine, 2-amino-2-methyl-1-propanol, diglycolamine, etc.), secondary alkanolamines (diethanolamine, diisopropanolamine, N-methylethanolamine, N-ethylethanolamine, N-butylethanolamine, etc.), and tertiary alkanolamines (triethanolamine, triisopropanolamine, diethanolmonoisopropanolamine, monoethanoldiisopropanolamine, N-cyclohexyldiethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, N-butyldiethanolamine, etc.). Tertiary alkanolamines are preferred. From the viewpoints of rust prevention and pH adjustment, etc. in the water-soluble metal working oil, the content of the rust inhibitor is, for example, 0.1% by mass or more and 20% by mass or less, preferably 0.5% by mass to 10% by mass or less. When two or more kinds are used in combination, the content means the total amount.

[0053] Examples of the metal corrosion inhibitor include phosphate esters, alkylphosphonic acids, sodium metasilicate, benzotriazole, etc. Benzotriazole is preferred. The metal corrosion inhibitor may be used alone or in combination of two or more kinds. In the water-soluble metal working oil, the content of the metal corrosion inhibitor is, for example, 0.01% by mass or more and 5% by mass or less, preferably 0.05% by mass to 3% by mass or less. When two or more kinds are used in combination, the content means the total amount.

[0054] Examples of fatty acids include monocarboxylic acids (such as caproic acid, enanthic acid, octanoic acid, 2-ethylhexanoic acid, nonanoic acid, isononanoic acid, decanoic acid, neodecanoic acid, lauric acid, myristic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, ricinoleic acid, castor oil fatty acid condensate, etc.), dicarboxylic acids (such as adipic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, etc.), etc. Monocarboxylic acids are preferred. Fatty acids may be used alone or in combination of two or more. From the viewpoints of lubricity, rust prevention, corrosion prevention, etc. in the water-soluble metal working oil, the content of fatty acids is, for example, 1% by mass or more and 30% by mass or less, preferably 3% by mass to 20% by mass or less. When two or more are used in combination, the content means the total amount.

[0055] Examples of the preservative include organic amines. Examples of the organic amines include cyclohexylamine, dicyclohexylamine, N-methyldicyclohexylamine, N,N-dimethyldicyclohexylamine, dibenzylamine, 1,3-bis(aminomethyl)cyclohexane, etc. Dicyclohexylamine is preferred. The preservative may be used alone or in combination of two or more. In the water-soluble metal working oil, the content of the preservative is, for example, 0.1% by mass or more and 15% by mass or less, preferably 0.5% by mass to 10% by mass or less. When two or more are used in combination, the content means the total amount.

[0056] Examples of the antifoaming agent include silicone-based antifoaming agents, higher alcohol-based antifoaming agents, polyether-based antifoaming agents, and metal soap-based antifoaming agents. Silicone-based antifoaming agents are preferred. The antifoaming agent may be used alone or in combination of two or more. In the water-soluble metal working oil, the content of the antifoaming agent is, for example, 0.01% by mass or more and 5% by mass or less, preferably 0.05% by mass to 3% by mass or less. When two or more are used in combination, the content means the total amount.

[0057] The water-soluble metalworking fluid of the embodiment is produced by mixing the above components. The addition order and mixing method of each component are not particularly limited. For example, the water-soluble metalworking fluid may be mixed by stirring the above components. The stirring conditions are not particularly limited, but for example, it may be stirred at a rotation speed of about 100 rpm for about 5 to 20 minutes at room temperature using a stirrer.

[0058] The water-soluble metalworking fluid of the embodiment may be produced by adding a hydroxy compound to the water-soluble metalworking fluid containing water, base oil, surfactant, etc. described above later.

[0059] The water-soluble metalworking fluid of the embodiment can be used as it is for processing a workpiece made of metal. However, since it has excellent water dispersibility, it can be particularly preferably used as a stock solution for a metalworking fluid in which the water-soluble metalworking fluid is diluted with dilution water.

[0060] [Metalworking Fluid] The metalworking fluid of the embodiment contains the above-described water-soluble metalworking fluid and dilution water. Examples of the dilution water include tap water, industrial water, ion-exchanged water, distilled water, sterilized purified water, etc., and it may be hard water or soft water. The dilution water may be used alone or in combination of two or more.

[0061] The dilution ratio when diluting the water-soluble metalworking fluid with dilution water can be appropriately adjusted according to the composition of the water-soluble metalworking fluid and the performance required during metal processing. The dilution ratio is not limited, but it is usually preferably diluted and used at 1.5 times or more and 100 times or less. From the viewpoints of water dispersibility and liquid stability, the dilution ratio is more preferably 5 times or more and 50 times or less, and even more preferably 10 times or more and 30 times or less.

[0062] From the viewpoint of corrosion inhibition, the pH of the metalworking fluid is preferably 6.5 or more and 11.0 or less, and more preferably 7.0 or more and 10.0 or less.

[0063] The metalworking fluid of the embodiment is obtained by diluting a water-soluble metalworking oil with dilution water. The method for diluting the water-soluble metalworking oil is not particularly limited, and it may be diluted by a known method. For example, it may be mixed by stirring using a rotor or a propeller or manually, or the water-soluble metalworking oil may be put into a container containing dilution water and diluted by stirring by natural convection.

[0064] The metalworking fluid according to the embodiment is excellent in dispersibility and workability, and can suppress the generation of stickiness in the apparatus in which the metalworking fluid is used. Therefore, it can be suitably used for various metalworking such as cutting, grinding, polishing, cutting, forging, pressing, rolling, wire drawing, drawing, and ironing of a workpiece made of metal. Examples of the workpiece include ferrous metals and their alloys, stainless steels, aluminum, aluminum alloys, magnesium, magnesium alloys, copper, copper alloys, and other non-ferrous metals and their alloys.

[0065] [Metalworking method] The metalworking method according to the embodiment processes a workpiece made of metal using the above-described metalworking fluid. Examples of the processing of the workpiece include cutting, grinding, polishing, cutting, forging, pressing, rolling, wire drawing, drawing, and ironing. The metalworking fluid is supplied to the processing point, for example, in a liquid state or a mist state. Examples of the workpiece include the metals described above.

[0066] [Method for improving dispersibility of water-soluble metalworking oil] The method for improving the dispersibility of the water-soluble metalworking oil according to the embodiment includes a step of mixing the above-described hydroxy compound, water, base oil, and surfactant. In the method for improving dispersibility according to the embodiment, since the water-soluble metalworking oil containing water, base oil, and surfactant further contains a hydroxy compound, the dispersibility of the water-soluble metalworking oil in water can be improved.

Examples

[0067] Hereinafter, the present invention will be described more specifically based on examples and comparative examples, but the present invention is not intended to be limited to those examples.

[0068] (Preparation of Water-Soluble Metalworking Fluid) [Example 1-1] For 100 parts by mass of a blank containing tap water, base oil, surfactant and additive, each component was weighed according to the composition shown in Table 2 so that the content of benzyl alcohol as a hydroxy compound was 4.0 parts by mass. Using a stir bar (15 mm × 35 mm, football type) and a stirrer ("SLOW STIRRER SW-600N-1" manufactured by Nisshin Rika Co., Ltd.), these were stirred and mixed at 5 graduations for about 15 minutes at room temperature to obtain the water-soluble metalworking fluid of Example 1-1. The composition of the blank is as shown in Table 1. In Example 1-1, the pH of the metalworking fluid diluted to 5 parts by mass with tap water was 9.0. The pH was measured using a pH meter ("F-52" manufactured by HORIBA).

[0069] [Examples 1-2 to 5-6, Comparative Examples 1-1 to 5-1] Metalworking fluid compositions of Examples 1-2 to 5-6 and Comparative Examples 1-1 to 5-1 were prepared in the same manner as in Example 1-1, except that the blending ratios of the respective components in the water-soluble metalworking fluid were as shown in Tables 2 to 6. The content of the hydroxy compound was 2.0 parts by mass in Examples 2-1 to 2-8 and Comparative Example 2-1, 3.0 parts by mass in Examples 3-1 to 3-8 and Comparative Example 3-1, 6.0 parts by mass in Examples 4-1 to 4-8 and Comparative Example 4-1, and 8.0 parts by mass in Examples 5-1 to 5-6 and Comparative Example 5-1, based on 100 parts by mass of the above-mentioned blank. Comparative Example 1-4 corresponds to a blank without the addition of the hydroxy compound.

[0070] (Evaluation of Water Dispersibility) Into a flat-bottomed beaker with a capacity of 500 mL, 380.0 g of tap water as dilution water and the above stir bar were respectively placed, and 20.0 g of each water-soluble metalworking fluid (undiluted solution) was added from a position about 15 cm above the water surface. Then, using the above stirrer, it was stirred and mixed at 3 graduations for 10 seconds, and allowed to stand for 30 seconds after stopping the stirring. After standing, the appearance of the diluted solution was visually confirmed and evaluated according to the following criteria. In the cases of A, B and C, it was determined that the water dispersibility was good. The evaluation results are shown in Tables 2 to 6. (Evaluation Criteria) A: No floating matter is visible on the surface of the diluent B: A small amount of floating matter is visible on the surface of the diluent C: A medium amount of floating matter is visible on the surface of the diluent D: A large amount of floating matter is visible on the surface of the diluent E: Emulsification failure has occurred

[0071] Figure 1 is an image explaining the evaluation criteria for water dispersibility. Note that Figure 1 is an exemplary image for explaining the evaluation criteria and does not limit the actual evaluation results. The dotted line in the image represents the area of floating matter.

[0072] Details of each component shown in Tables 1 to 6 are as follows. <Base Oil> Paraffinic mineral oil 2-Ethylhexyl oleate <Surfactant> Nonionic surfactant 1: Laurylamine EO 15 mol adduct Nonionic surfactant 2: Sorbitan monooleate Nonionic surfactant 3: Polyoxyalkylene lauryl ether Anionic surfactant: Sodium sulfonate <Additive> Rust inhibitor: N-Cyclohexyldiethanolamine Metal corrosion inhibitor: Benzotriazole Fatty acids: Oleic acid Preservative: Dicyclohexylamine Antifoaming agent: Silicone-based antifoaming agent <Hydroxy Compound> Hydroxy compound A1: Benzyl alcohol (manufactured by LANXESS, in formula (1), where R 1 is a cyclic hydrocarbon group with 7 carbon atoms and n is 0 compound) Hydroxy compound A2: Benzyl alcohol EO 1 mol adduct (manufactured by Aoki Yushi Kogyo Co., Ltd., "BLAUNON BA-1", in formula (1), where R 1 is a cyclic hydrocarbon group with 7 carbon atoms and R2 (a compound in which R is an alkylene group having 2 carbon atoms and n is 1) Hydroxy compound A3: 2-phenoxyethanol (manufactured by Fujifilm Wako Pure Chemical Corporation; in formula (1), R 1 is a cyclic hydrocarbon group having 6 carbon atoms, and R 2 is an alkylene group having 2 carbon atoms and n is 1) Hydroxy compound A4: 2-phenoxyisopropanol (manufactured by Tokyo Chemical Industry Co., Ltd.; in formula (1), R 1 is a cyclic hydrocarbon group having 6 carbon atoms, and R 2 is an alkylene group having 3 carbon atoms and n is 1) Hydroxy compound A5: 2-ethylhexanol (manufactured by Tokyo Chemical Industry Co., Ltd.; in formula (1), R 1 is a branched hydrocarbon group having 8 carbon atoms and n is 0) Hydroxy compound A6: monoethylene glycol mono-2-ethylhexyl ether (manufactured by Nippon Emulsifier Co., Ltd., "2-ethylhexyl glycol"; in formula (1), R 1 is a branched hydrocarbon group having 8 carbon atoms, and R 2 is an alkylene group having 2 carbon atoms and n is 1) Hydroxy compound A7: diethylene glycol mono-2-ethylhexyl ether (manufactured by Nippon Emulsifier Co., Ltd., "2-ethylhexyl diglycol"; in formula (1), R 1 is a branched hydrocarbon group having 8 carbon atoms, and R 2 is an alkylene group having 2 carbon atoms and n is 2) Hydroxy compound B1: Polymer of hydroxy unsaturated fatty acid Hydroxy compound B2: 1-octanol (in formula (1), R 1 is a straight-chain saturated hydrocarbon group having 8 carbon atoms and n is 0) Hydroxy compound B3: tetraethylene glycol mono-2-ethylhexyl ether (in formula (1), R 1 is a branched hydrocarbon group having 8 carbon atoms, and R 2 is an alkylene group having 2 carbon atoms and n is 4) Hydroxy compounds A1 to A7 are the hydroxy compounds of the present disclosure, and hydroxy compounds B1 to B3 are comparative compounds.

[0073]

Table 1

[0074]

Table 2

[0075]

Table 3

[0076]

Table 4

[0077]

Table 5

[0078]

Table 6

[0079] As is apparent from Tables 2 to 6, it can be seen that in the examples containing the hydroxy compound represented by the formula (1), the dispersibility of the stock solution in water is good. In the comparative examples not containing the hydroxy compound represented by the formula (1), the dispersibility of the stock solution in water was poor.

[0080] From Examples 1-5 and Comparative Examples 1-2, R in formula (1) 1When it is a linear saturated hydrocarbon group, it can be seen that the water dispersibility is poor. From Examples 1-7 and Comparative Examples 1-3, it can be seen that when n in the formula (1) exceeds 2, the water dispersibility is poor. When n of the hydroxy compound becomes too large, that is, when the addition amount of ethylene oxide or propylene oxide becomes too large, the interaction on the hydrophilic group side of the surfactant becomes stronger, and it is presumed that the effect of improving water dispersibility cannot be obtained.

[0081] From each example, it can be seen that as the content of the hydroxy compound increases, the water dispersibility tends to improve.

[0082] From the above, it was confirmed that the water-soluble metal working oil agent of the present disclosure is excellent in water dispersibility.

Claims

1. A water-soluble metalworking oil containing a hydroxy compound represented by the following general formula (1), water, a base oil, and a surfactant. Water-soluble metalworking oil agent. 【Chemical 1】 [In the formula, R 1 is an optionally substituted branched or cyclic hydrocarbon group having 6 to 8 carbon atoms or a linear unsaturated hydrocarbon group, R 2 is an alkylene group having 2 or 3 carbon atoms, n is an integer from 0 to 2. ]

2. In the general formula (1), R 1 The water-soluble metal working oil composition according to claim 1, wherein 1 is an aryl group.

3. In the general formula (1), R 2 The water-soluble metal working oil agent according to claim 1 or claim 2, wherein the alkylene group in has 2 carbon atoms.

4. The water-soluble metalworking oil according to Claim 1 or Claim 2, wherein n is 1 or 2 in the general formula (1).

5. The water-soluble metalworking oil according to Claim 1 or Claim 2, wherein the content of the hydroxy compound is 1.5% by mass or more and 10% by mass or less.

6. The water-soluble metalworking oil according to Claim 1 or Claim 2, wherein the mass ratio (hydroxy compound / surfactant) of the content of the hydroxy compound to the content of the surfactant is 0.05 or more and 1.0 or less.

7. The water-soluble metalworking oil according to Claim 1 or Claim 2, wherein the surfactant is at least one selected from the group consisting of a nonionic surfactant and an anionic surfactant.

8. A metalworking fluid obtained by diluting the water-soluble metalworking oil according to Claim 1 or Claim 2 with water.

9. A metalworking method of processing a workpiece made of metal using the metalworking fluid obtained by diluting the water-soluble metalworking oil according to Claim 1 or Claim 2 with water.

10. A method for improving the dispersibility of a water-soluble metalworking oil, comprising the step of mixing a hydroxy compound represented by the following general formula (1), water, a base oil, and a surfactant. 【Chemical 1】 [In the formula, R 1 is an optionally substituted branched or cyclic hydrocarbon group having 6 to 8 carbon atoms or a linear unsaturated hydrocarbon group, R 2 is an alkylene group having 2 or 3 carbon atoms, n is an integer from 0 to 2. ]

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