WO2020012792A1

WO2020012792A1 - Water-soluble oil composition for metalworking

Info

Publication number: WO2020012792A1
Application number: PCT/JP2019/020734
Authority: WO
Inventors: 将吾緒方
Original assignee: 株式会社ネオス
Priority date: 2018-07-12
Filing date: 2019-05-24
Publication date: 2020-01-16
Also published as: JPWO2020012792A1; SG11202011331SA; TW202006129A; CN112204121A

Abstract

The purpose of the present invention is to provide a water-soluble oil composition for metalworking, which contains an alkanolamine or the like, and which is not susceptible to decrease in the pH or decrease in the concentration. A water-soluble oil composition for metalworking according to the present invention contains a primary alkanolamine which has a substituent that inhibits an intermolecular dehydration cyclization reaction. This water-soluble oil composition for metalworking is characterized in that the primary alkanolamine is represented by formula (I). (In the formula, R₁, R₂, R₃ and R₄ represent hydrogen atoms, or alkyl groups having 1-6 carbon atoms or cycloalkyl groups having 3-6 carbon atoms, which may be the same as or different from each other, provided that both R₁ and R₂ are alkyl groups having 1-6 carbon atoms or cycloalkyl groups having 3-6 carbon atoms, and/or both R₃ and R₄ are alkyl groups having 1-6 carbon atoms or cycloalkyl groups having 3-6 carbon atoms.)

Description

Water-soluble oil composition for metalworking

The present invention relates to a water-soluble oil composition for metal working. More specifically, the present invention relates to an oil composition which is used for metal cutting, grinding, plastic working, precision polishing, and the like, and has an antiseptic and rust preventive effect on a metal surface.

Oil-based compositions have been used as oil compositions for metal processing such as cutting and grinding, but water-soluble oil compositions are widely used from the viewpoint of suppressing fire hazard and improving workability. It is supposed to be. The water-soluble oil composition is a mixture containing lubricating oil, an oil agent, an antiwear agent, an extreme pressure additive, a rust inhibitor, a surfactant and the like as constituent components. In particular, alkanolamines such as monoethanolamine, diethanolamine, and triethanolamine are blended for the purpose of preventing rust and maintaining the pH of the oil composition.

WO 2014/129499 discloses an aqueous metalworking oil containing two types of alkanolamines having a predetermined structure. JP-A-2002-338988 discloses a water-soluble cutting and grinding oil for alloys containing a dibasic acid, a mineral oil and / or a fat, an alkali metal compound and / or an amine, and a surfactant.

Monoisopropanolamine (MIPA), which is mentioned as an example of alkanolamines contained in the metalworking oils of the above-mentioned documents, is an alkaline substance and forms an amine salt with a fatty acid to exhibit a surface active effect. Often used as an alkanolamine component in metalworking oils. However, if the metal working oil containing MIPA is continuously used, there is a problem that the pH deteriorates due to aging. Metalworking fluids are usually used in circulation and are continuously used while adding new metalworking fluids, but the pH does not increase or the concentration of MIPA does not increase even if new metalworking fluids are added. was there. This is because, when a metal working oil is exposed to frictional heat generated between a tool and a work material generated during metal working, two MIPA molecules contained in the metal working oil undergo a cyclization dehydration reaction between the molecules to form dimethylpyrazine. It is presumed that MIPA gradually decreases due to formation. Accordingly, an object of the present invention is to provide a water-soluble oil agent composition for metalworking, which contains an alkanolamine that hardly causes a decrease in pH or concentration.

水溶 The water-soluble oil agent composition for metal working in the embodiment of the present invention is characterized by containing a primary alkanolamine having a substituent that inhibits intermolecular cyclization dehydration reaction.

The water-soluble oil composition for metalworking of the present invention is characterized in that pyrazines are generated by increasing the temperature during metalworking, the concentration of the alkanolamine component is reduced, or the pH of the oil solution composition is not reduced. It can be used continuously for a long time without deterioration.

FIG. 1 shows an oil agent composition (Product A containing 2-amino-2-methyl-1-propanol (AMP)) before use, after use for 5 months, after use for 5 months, after use for 11 months, 8 is a GC-MS spectrum of the oil composition after use for 8 months. FIG. 2 is a GC-MS spectrum of the oil composition before use (Product B containing monoisopropanolamine (MIPA)) and the oil composition after one month of use.

実施 The embodiment of the present invention will be described below. An embodiment of the present invention is a water-soluble oil agent composition for metal working containing a primary alkanolamine having a substituent that inhibits intermolecular cyclization dehydration. In the present embodiment, the oil agent composition is a mixture containing an oil component. Generally, an oil agent composition contains a synthetic oil such as a polyalkylene glycol as a lubricant in addition to a natural oil such as a mineral oil, and also includes an oil agent, an antiwear agent, an extreme pressure additive, a rust inhibitor, a preservative, and an interface. An activator and the like are contained as constituents. Water-soluble means that it is easily dissolved in water and has high affinity with water. The water-soluble oil composition is in the form of an emulsion, a transparent aqueous solution or a translucent soluble aqueous solution which can be used after being diluted with water. Metal working means cutting, grinding, plastic working, rolling, and the like of metal. The water-soluble oil agent composition for metal working is required to have the effect of maintaining the lubricity of the metal surface, cooling the metal surface, and preventing rust on the metal surface during these operations. The intermolecular cyclization dehydration reaction in this embodiment will be described later.

In embodiments, the primary alkanolamine has the following formula (I):

(R ₁ , R ₂ , R ₃ and R ₄ are hydrogen or the same or different alkyl groups having 1 to 6 carbon atoms or cycloalkyl groups having 3 to 6 carbon atoms, wherein R ₁ and R ₂ are Both are alkyl groups having 1 to 6 carbon atoms or cycloalkyl groups having 3 to 6 carbon atoms, and / or R ₃ and R ₄ are both alkyl groups having 1 to 6 carbon atoms or cycloalkyl groups having 3 to 6 carbon atoms. .). In the formula (I), two alkyl groups are present on at least one of the carbons adjacent to the amino group (—NH ₂ ) or the hydroxyl group (—OH). As described above, monoisopropanolamine (MIPA) has been conventionally added as an alkanolamine to metalworking oils. MIPA, under high temperature conditions during metal working and contact with metals, has the following:

In some cases to form dimethylpyrazine. Such a reaction in which two primary alkanolamine molecules form a ring while dehydrating between molecules is referred to as an intermolecular cyclization dehydration reaction in this specification. When a metal working oil is used for a long time, dimethylpyrazine is generated by the above-mentioned intermolecular cyclization dehydration reaction, MIPA gradually decreases, and accordingly, the pH of the metal working oil sometimes decreases.

R ₁ , R ₂ , R ₃ and R ₄ of the primary alkanolamines of the formula (I) used in this embodiment are hydrogen, or the same or different alkyl groups having 1 to 6 carbon atoms or 3 to 4 carbon atoms. 6 is a cycloalkyl group. The alkyl group having 1 to 6 carbon atoms may be linear or branched. The cycloalkyl group having 3 to 6 carbon atoms is a cyclic alkyl group such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group or a cyclohexyl group. Then, the substitution group _R _1, R 2, _{R 3} and _{R 4,} _{R 1} and _{R 2} are both alkyl or cycloalkyl group having 3 to 6 carbon atoms having 1 to 6 carbon atoms, _{R 3} and R ₄ satisfies at least either one of an alkyl group having 1 to 6 carbon atoms and a cycloalkyl group having 3 to 6 carbon atoms. For this reason, the substituents R ₁ and R ₂ and / or R ₃ and R ₄ become an obstacle between the two alkanolamine molecules, and the intermolecular cyclization dehydration reaction hardly occurs. In the oil agent composition of the embodiment, even when used for a long period of time, pyrazines are hardly generated, the concentration of the alkanolamine component is hardly reduced, and the pH is hardly reduced. Here, pyrazines refer to pyrazine and pyrazine having a substituent. Suitable groups for the substituents R ₁ , R ₂ , R ₃ and R ₄ are alkyl groups having 1 to 6 carbon atoms, preferably alkyl groups having 1 to 3 carbon atoms, or cycloalkyl groups having 3 to 6 carbon atoms. is there. It is considered that an increase in the number of carbon atoms in the alkyl group or the cycloalkyl group increases the steric hindrance between the two alkanolamine molecules, so that the intermolecular cyclization dehydration reaction can be more effectively inhibited. However, when the carbon number of the alkyl group or the cycloalkyl group is too large, the water solubility of the alkanolamine itself is reduced, so that it cannot be used as a component of the water-soluble oil composition of the present embodiment. Therefore, the substituents R ₁ , R ₂ , R ₃ and R ₄ are particularly preferably an alkyl group having 1 to 3 carbon atoms. From the viewpoints of both maintaining the water solubility of alkanolamines and suppressing the formation reaction of pyrazines, a group particularly preferable as the substituents R ₁ , R ₂ , R ₃ and R ₄ is an alkyl group having 1 or 2 carbon atoms. Ie, a methyl group or an ethyl group.

In embodiments, the primary alkanolamines of formula (I) include, for example, 2-amino-2-methyl-1-propanol, 1-amino-2-methyl-2-propanol, 3-amino-3-methyl- 2-butanol, 3-amino-2-methyl-2-butanol, 3-amino-2,3-dimethyl-2-butanol, 2-amino-2-ethyl-1-propanol, 1-amino-2-ethyl- 2-propanol can be mentioned.

において In the embodiment, the primary alkanolamine is added to the water-soluble oil agent composition for metal working in order to impart rust resistance and antiseptic property to the metal surface. For this purpose, the primary alkanolamine can be added in a proportion of 1 to 20%, preferably 2 to 15%, based on the weight of the water-soluble oil agent composition for metal working. The primary alkanolamines can be used alone or in combination of two or more. When two or more primary alkanolamines are used as a mixture, the total amount of the mixed primary alkanolamines is preferably 1 to 20% based on the weight of the water-soluble oil agent composition for metal working.

The water-soluble oil agent composition for metal working of the embodiment is, in addition to the above primary alkanolamine, water, mineral oil, animal and vegetable oil, hydrocarbon synthetic oil, fatty acid, fatty acid condensate, fatty acid ester, organic amine, surface activity Additives such as an agent, an antiwear agent, an extreme pressure additive, a rust inhibitor, a preservative, and an antifoaming agent can be added.

Mineral oil is a mixture of hydrocarbon compounds derived from petroleum, natural gas, etc. For example, a paraffinic oil or a naphthenic oil can be used. Mineral oil is used as a base oil of a water-soluble oil agent composition for metal working. Two or more of the above mineral oils can be used in combination as needed.

As animal and vegetable oils, vegetable oils such as castor oil, rapeseed oil, palm oil, soybean oil, olive oil, and animal oils such as tallow, sheep, lard, fish oil and the like can be used. Animal and vegetable oils are used as base oils for water-soluble oil agent compositions for metal working. Two or more of the above-mentioned animal and vegetable oils can be used in combination as needed.

として As the hydrocarbon synthetic oil, synthetic hydrocarbon oils represented by α-polyolefin, polybutene, etc., ether synthetic oils represented by alkyl diphenyl ether, polypropylene glycol, etc., silicone oil, fluorine oil and the like can be used. Two or more of the above-mentioned hydrocarbon-based synthetic oils can be used in combination as needed.

Fatty acids are carboxylic acids of long-chain hydrocarbons. The fatty acid condensate is an intermolecular dehydration condensate of fatty acids, and the fatty acid ester is an ester compound of a fatty acid and an alcohol. Fatty acids, fatty acid condensates, and fatty acid esters are added as a rust inhibitor and a lubricant for a water-soluble oil composition for metal working. Fatty acids suitably used in the water-soluble oil agent composition for metal working include butyric acid, valeric acid, caprylic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, arachidic acid, and the like. Can be used as On the other hand, fatty acid esters suitably used in the water-soluble oil agent composition for metal working include methyl laurate, methyl stearate, methyl oleate, methyl castor fatty acid, butyl palmitate, octyl stearate, isopropyl myristate. Esters and trimethylolpropane caprylate. Two or more of the above fatty acids, fatty acid condensates and fatty acid esters can be used in combination depending on the use and desired function.

(4) The organic amine is added to the water-soluble oil composition for metal working in order to impart rustproof and antiseptic properties to the metal surface, like the primary alkanolamine. The amines preferably used in the water-soluble oil agent composition for metal working include alkylamines having 1 to 5 carbon atoms such as ethylamine and propylamine, cycloalkylamines having 5 to 20 carbon atoms such as morpholine and cyclohexylamine, and diamines such as diethanolamine. And tertiary alkanolamines such as tertiary alkanolamine and triethanolamine. Two or more organic amines can be used in combination depending on the application and desired function.

The surfactant is added to maintain the water-soluble oil agent composition for metal working as a stable composition. As the surfactant, any of a cationic surfactant, an anionic surfactant, a nonionic surfactant, and an amphoteric surfactant can be used. Examples of suitable cationic surfactants include quaternary ammonium salts. Suitable anionic surfactants include alkyl group-containing sulfonates, alkyl group-containing sulfonates, alkyl group-containing phosphates, alkyl group-containing phosphates, organic fatty acids and organic fatty acid derivatives, and the like. Particularly preferred are sulfonic acid salts, organic fatty acids and organic fatty acid derivatives. Suitable nonionic surfactants include alkyl alcohol-ethylene oxide adducts, terminal alkyl ethers of alkyl alcohol-ethylene oxide adducts, organic fatty acid-ethylene oxide adducts, hydroxy fatty acid-ethylene oxide adducts, pluronic surfactants, Examples include tronic surfactants and sugar ester-ethylene oxide adducts. Examples of suitable amphoteric surfactants include alkyl betaines. The above surfactants can be used in combination of two or more depending on the use and desired function.

Anti-wear agents are added to prevent friction, wear and seizure between the two surfaces of the metal. Suitable examples of the antiwear agent include phosphoric acid esters (such as tricresyl phosphate and lauryl acid phosphate), phosphites (such as tributyl phosphite and dilauryl phosphite), and thiophosphates (dialkyldithiophosphoric acid). Zinc acid, zinc diallyldithiophosphate), phosphoric acid ester amine salts, and zinc dialkyldithiocarbamate. Two or more of the above antiwear agents can be used in combination as needed.

Extreme pressure additives are added to prevent friction, wear and seizure between the two surfaces of the metal. As extreme pressure additives, for example, sulfurized fats (such as sulfurized palm oil), sulfurized esters (such as sulfurized fatty esters), sulfides (such as dibenzyl disulfide, alkyl polysulfide, olefin polysulfide, and Zantic sulfide), and chlorine compounds (chlorinated) Paraffin, methyltrichlorostearate, etc.), lead naphthenate, amine alkylthiophosphates, chloroalkyl xanthate. Two or more of the above extreme pressure additives can be used in combination as needed.

錆 A rust inhibitor is added to suppress the generation of rust on the metal surface. As a rust inhibitor, calcium sulfonate, calcium phenate, calcium salicylate, magnesium sulfonate, magnesium phenate, magnesium salicylate, barium sulfonate, barium phenate, barium salicylate, glycerin monooleate, glycerin monolaurate, glycerin monostearate, sorbitan Monooleate, sorbitan monolaurate, sorbitan monostearate and the like can be used. Two or more of the above rust preventives can be used in combination as needed.

Preservatives are added to prevent the growth of microorganisms, especially in water-soluble oil compositions. As preservatives, thiazoles such as 2-methyl-4-isothiazolin-3-one, 1,2-benzoisothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one, 3-iodo Iodine compounds such as -2-propargylbutylcarbamic acid, phenol compounds such as o-phenyl-phenol, p-chloro-m-cresol and 3-methyl-4-chloro-phenol, sodium 2-pyridinethiol-1-oxide Pyridine type; triazine type such as hexahydro-1,3,5-tris (2-hydroxyethyl) -S-triazine; hexahydro-1,3,5-triethyl-S-triazine; 1,2-dibromo-2 , Such as 2,4-dicyanobutane and 2-bromo-2-nitropropane, water-soluble glass-silver, zeolite-copper Inorganic, polydioxyethylene (dimethylimino) ethylene (dimethylimino) ethylenedichloride, 5-methyloxazolidine, 4- (2-nitrobutyl) morpholine, tris (hydroxymethyl) nitromethane, 4,4 '-(2- Ethyl-2-nitrotrimethylene) dimorpholine, boric acid and the like can be used. The above preservatives can be used in combination of two or more as required.

An antifoaming agent is added to prevent foaming due to a surfactant contained in the oil composition. Examples of the antifoaming agent include organic antifoaming agents such as silicone-based antifoaming agents, polyols, and higher alcohols. Two or more of the above-mentioned antifoaming agents can be used in combination as needed.

水溶 In addition to these components, a non-ferrous metal anticorrosive, an organic acid, an alcohol, a chelating agent, a coloring agent, a fragrance, and the like can be appropriately added to the water-soluble metal composition for metal working according to the embodiment according to the application.

The water-soluble oil agent composition for metal working of the embodiment can be obtained by mixing these components at an appropriate ratio. Each component may be blended in a ratio well known to those skilled in the art according to conventionally used metalworking oils. Each component of the water-soluble oil agent composition for metal working of the embodiment has an effect of suppressing an intermolecular cyclization dehydration reaction of a primary alkanolamine, an effect of suppressing pyrazine production, and an effect of suppressing a decrease in pH of the oil agent composition. Is also blended so as not to interfere.

The oil agent composition of the embodiment containing the primary alkanolamine is characterized in that the production of pyrazines by the intermolecular cyclization dehydration reaction of the primary alkanolamine is suppressed. Here, the generation of pyrazines by the intermolecular cyclization dehydration reaction of a primary alkanolamine means that the amino group of a primary alkanolamine molecule and the hydroxyl group of another primary alkanolamine molecule undergo a dehydration reaction between the molecules to form a ring structure. Of the two alkanolamines to form pyrazines. The pyrazines refer to pyrazine and pyrazine having a substituent. Even when two molecules of the primary alkanolamine used in the embodiment are close to each other, the substituents R ₁ and R ₂ are both an alkyl group having 1 to 6 carbon atoms or a cycloalkyl group having 3 to 6 carbon atoms, and / or Since both R ₃ and R ₄ are an alkyl group having 1 to 6 carbon atoms or a cycloalkyl group having 3 to 6 carbon atoms, the substituents R ₁ and R ₂ and / or R ₃ and R ₄ become obstacles, and Less likely to cause cyclization dehydration reaction.

For this reason, even if the oil agent composition of the embodiment is used for metal processing for a long period of time, generation of pyrazines is suppressed.

The oil agent composition of the embodiment containing a primary alkanolamine is characterized in that a decrease in the concentration of the primary alkanolamine accompanying use is suppressed. Here, the decrease in the concentration of the primary alkanolamine means that the primary alkanolamine changes into a compound different from the primary alkanolamine, and the concentration of the primary alkanolamine itself decreases. When the oil agent composition of the embodiment is used for metal processing for a long period of time, it is exposed to severe conditions such as high heat and high shear, and primary alkanolamine causes a decomposition reaction or the like, or, for example, as described above. As in the case of intermolecular cyclization dehydration reaction of monoisopropanolamine (MIPA), two primary alkanolamine molecules may condense with each other. The primary alkanolamine used in the oil agent composition of the present embodiment is such that both of the substituents R ₁ and R ₂ are an alkyl group having 1 to 6 carbon atoms or a cycloalkyl group having 3 to 6 carbon atoms, and / or Alternatively, since R ₃ and R ₄ are both an alkyl group having 1 to 6 carbon atoms or a cycloalkyl group having 3 to 6 carbon atoms, such a condensation reaction hardly occurs. For this reason, in the oil agent composition of the embodiment, a decrease in the concentration of the primary alkanolamine due to use is suppressed.

(1) Examination of components of oil agent composition before and after use 1
Oil composition containing 2-amino-2-methyl-1-propanol (AMP), which is a primary alkanolamine, and oil composition containing monoisopropanolamine (MIPA) conventionally used Was used for a long period of time in metalworking applications, and it was examined whether the constituent components changed before and after use.

(1-1) Example 1
An oil composition containing 3.6% of AMP as alkanolamine (Product A, Neos Co., Ltd.) was used for metal processing for 5 to 11 months. Before and after the use of the oil composition, GC-MS measurement was performed to analyze the constituent components. The GC-MS measuring instrument was JMS-Q1050GV (JEOL Corporation), the column used for measurement was CP-Volamine (Agilent Technologies), and the diluting solvent was ion-exchanged water or methanol. The dilution was performed at an arbitrary magnification according to the measurement sample. Table 1 shows the conditions of the GC-MS measurement.

FIG. 1 shows the GC-MS of the oil solution composition (new solution) before use, and after use for 5 months, after use for 5 months, after use for 11 months, and after use for 8 months. The spectrum is shown. In FIG. 1: GC-MS spectrum of product A new solution, 2: GC-MS spectrum of product A after use for about 5 months at Company S, 3: GC-MS spectrum of product A after use for about 5 months at NS, 4: GC-MS spectrum of product A after use by Company N for about 11 months. 5: GC-MS spectrum of product A after used by Company D for about 8 months.

(1-2) Comparative Example 1
An oil agent composition containing 2.0% of MIPA as alkanolamine (Product B, Neos Co., Ltd.) was used for one month for metal working. Before and after the use of this oil composition, GC-MS measurement was performed under the same conditions as in Example 1 to analyze the constituent components. FIG. 2 shows the GC-MS spectra of the oil composition before use and the oil composition after one month of use. In FIG. 1: GC-MS spectrum of product B new solution, 2: GC-MS spectrum of product B after use by Company M for about one month.
The components of the oil agent composition used in Example 1 and Comparative Example 1 are shown in Table 2 below.

In FIG. 1 (Example 1), there is no change in the components of the oil agent composition before and after use. However, in FIG. 2 (Comparative Example 1), in the spectrum of the oil agent composition after use, a peak based on a new component that was not present in the new liquid (the peak at around 16 minutes in spectrum No. 2 in FIG. 2) was observed. . When the component belonging to this peak was identified by mass spectrometry (MS), it was found to be 2,5-dimethylpyrazine.

油 The oil agent composition of the present invention does not generate pyrazines due to the intermolecular cyclodehydration reaction of alkanolamine even when used at high temperatures for a long period of time. Thereby, it can be said that a decrease in the concentration of the alkanolamine and a decrease in the pH of the oil agent composition are unlikely to occur. On the other hand, when the oil composition of the comparative example is used at a high temperature for a long period of time, alkanolamine (MIPA) undergoes intermolecular cyclodehydration reaction to generate pyrazines. May decrease in pH.

(2) Examination of components of oil agent composition before and after use 2
An oil agent composition containing 2-amino-2-methyl-1-propanol (AMP), which is a primary alkanolamine, and an oil agent composition containing monoisopropanolamine (MIPA) are each subjected to metal working. It was used for a long period of time, and it was examined whether the constituent components changed before and after use.

(2-1) Example 2
Of AMP which is a primary alkanolamine, triethanolamine (TEA) which is a tertiary alkanolamine, and N, N-bis (2-hydroxyethyl) -N-cyclohexylamine (CH-020) which is a tertiary alkanolamine An oil agent composition product A (Neos Co., Ltd., AMP: 3.6%, TEA: 2.0%) containing at least two of the following, and a product C (Neos Co., Ltd., AMP: 1.8%, CH-020: 2.0%) for one to five months for metalworking applications. Before and after use of these oil compositions, capillary electrophoresis analysis (CE) was performed. The CE measuring instrument was G1600A (Agilent Technologies), the column used for the measurement was G1600-61232 (Agilent Technologies, 50 μm ID × 56 cm), and the dilution solvent was ion-exchanged water. The dilution was performed at an arbitrary magnification according to the measurement sample. Table 3 shows the conditions of the CE measurement.

Table 4 below shows the ratio of the AMP concentration to the tertiary alkanolamine concentration in the oil composition before use and the oil composition after 1 to 6 months of use, calculated by CE measurement. Show.

(2-2) Comparative Example 2
MIPA which is a primary alkanolamine, triethanolamine (TEA) which is a tertiary alkanolamine, and N, N-bis (2-hydroxyethyl) -N-cyclohexylamine (CH-020) which is a tertiary amine An oil agent composition product D (Neos Co., Ltd., MIPA: 3.0%, TEA 4.0%) and a product B (Neos Co., Ltd., MIPA: 2.0%, TEA: 2.0%) containing at least two types Used for one to three months for metal working applications. Before and after use of this oil composition, CE measurement was performed under the same conditions as in Example 2. Table 5 below shows the ratio of the MIPA concentration to the tertiary alkanolamine concentration in the oil composition before use and the oil composition after 1 to 6 months of use, calculated by CE measurement. Show.
Table 2 shows the components of the oil agent composition used in Example 2 and Comparative Example 2.

油 The oil composition of the present invention containing AMP shows almost no change in AMP concentration even after long-term use. Since the oil agent composition of the present invention shows no change in the concentration of other amines (TEA, CH-020) even after long-term use, it is presumed that the pH of the oil agent composition hardly decreases. On the other hand, it can be seen that the oil composition of the comparative example containing MIPA has a reduced concentration of MIPA when used for a long time. It is inferred that the pH of the oil agent composition has also been lowered accordingly.

Claims

(4) A water-soluble oil agent composition for metal working, comprising a primary alkanolamine having a substituent that inhibits intermolecular cyclization dehydration reaction.
The primary alkanolamine has the following formula (I):

(R 1 , R 2 , R 3 and R 4 are hydrogen or the same or different alkyl groups having 1 to 6 carbon atoms or cycloalkyl groups having 3 to 6 carbon atoms, wherein R 1 and R 2 are Both are alkyl groups having 1 to 6 carbon atoms or cycloalkyl groups having 3 to 6 carbon atoms, and / or R 3 and R 4 are both alkyl groups having 1 to 6 carbon atoms or cycloalkyl groups having 3 to 6 carbon atoms. Is.)
The water-soluble oil composition for metalworking according to claim 1, which is represented by:
The water for metal working according to claim 1 or 2, wherein the production of pyrazines by the intermolecular cyclization dehydration reaction of the primary alkanolamine with the use of the water-soluble oil agent composition for metal working is suppressed. Soluble oil composition.
The water-soluble oil composition for metal processing according to any one of claims 1 to 3, wherein a decrease in the concentration of the primary alkanolamine accompanying the use of the water-soluble oil composition for metal processing is suppressed.