TW201602334A - Water-soluble metalworking oil, and metalworking coolant - Google Patents

Abstract

This water-soluble metalworking oil is characterized by: being obtained by mixing a dicarboxylic acid (A) including a sulfide structure, and a monocarboxylic acid (B); and not including polyalkylene glycol. This metalworking coolant is obtained by using water to dilute the aforementioned water-soluble metalworking oil.

Description

Water-soluble metal processing oil and coolant for metal processing Field of invention

The present invention relates to a water-soluble metal working oil and a metal working coolant which is diluted with water.

Background of the invention

Metalworking oils which can be used for metal working are oil-based (oily) and water-based (aqueous), and most of them use an aqueous formulation which is excellent in cooling property and wettability and which is free from fire.

In particular, in the use of grinding, the cooling property of the oil agent is very important. Therefore, a solution-based oil agent containing no ore oil is often used (for example, refer to Japanese Patent Publication No. 40-14480). The oil-based solution of the solution is excellent in cooling property and corrosion resistance, but is inferior to non-aqueous, emulsion-based, and soluble in lubricity. The lack of lubricity also causes deterioration of the rough surface of the machined surface, a decrease in the life of the grindstone, or a burn of the grind.

Here, in order to impart lubricity to the oil-based solution, a polyalkylene glycol (PAG) is blended with an oil agent (refer to Japanese Laid-Open Patent Publication No. Hei 10-324888, No. 2010-70736) .

In the solution-based oil agents described in Documents 2 and 3, the lubricity is improved by increasing the blending amount of PAG. But even if a large amount of PAG is blended, it can be improved. Lubricity is still limited. Therefore, under severe processing conditions, the friction coefficient between the grindstone and the material to be cut becomes large, which leads to a decrease in the life of the grindstone and a burn of the grind.

Summary of invention

An object of the present invention is to provide a water-soluble metal working oil which is excellent in lubricity and abrasion resistance even under severe processing conditions, and a metal working coolant which is diluted with water.

The present inventors have found that in a system in which a dicarboxylic acid having a sulfide structure is used in combination with a long-chain carboxylic acid, the removal of PAG adversely affects both lubricity and abrasion resistance. The present invention has been completed on the basis of this finding.

That is, the present invention provides a water-soluble metal working oil and a coolant for metal working as described below.

[1] A water-soluble metal working oil characterized in that it is blended with (A) a sulfide-containing dicarboxylic acid and (B) a monocarboxylic acid, and does not contain a polyalkylene glycol.

[2] In the water-soluble metal working oil, the component (A) compounds of formula (1) is _{^{of: HOOC-R 1 -S n -R}} 2 -COOH ... (1)

(R ¹ and R ² are each independently a hydrocarbon group having 1 or more and 5 or less carbon atoms, and n is an integer of 1 or more and 8 or less).

[3] In the water-soluble metal working oil, the blending amount of the component (A) is 0.1% by mass or more and 14% by mass or less based on the total amount of the processing oil.

[4] In the above water-soluble metal working oil, the component (B) is a compound of the following formula (2): R ³ -COOH (2)

(R ³ is a hydrocarbon group having 11 or more carbon atoms).

[5] In the water-soluble metal working oil, the blending amount of the component (B) is 1% by mass or more and 20% by mass or less based on the total amount of the processing oil.

[6] The above water-soluble metal working oil is further blended with (C) an acetylene glycol-based surfactant.

[7] In the water-soluble metal working oil, the blending amount of the component (C) is 1% by mass or more and 15% by mass or less based on the total amount of the processing oil.

[8] The water-soluble metal working oil is a stock solution in which 15% by mass or more and 75% by mass or less of water is blended.

[9] A coolant for metal working, characterized in that the water-soluble metal working oil is diluted with water by a factor of 2 or more and 200 times or less (volume).

[10] The above metal working coolant is used for grinding.

The water-soluble metal working oil agent (stock solution) of the present invention is blended with (A) a sulfide-containing dicarboxylic acid and (B) a monocarboxylic acid, and does not contain a polyalkylene glycol, so that it is diluted with water to form a metal. When the coolant is processed, it exhibits good lubricity and abrasion resistance. Therefore, when the coolant for metal working of the present invention is used for grinding, even under severe processing conditions, it is difficult to cause deterioration of the roughness of the machined surface, and the burn life and the life of the grindstone can be sufficiently suppressed. low.

Embodiment of the invention

Embodiments of the present invention will be described below.

The water-soluble metal working oil of the present invention (hereinafter also referred to as "the processing oil") is a raw liquid in which (A) a sulfide-containing dicarboxylic acid and (B) a monocarboxylic acid are blended, and does not contain a polyalkylene glycol. . Hereinafter, the processing oil and the coolant for metal working which are diluted with water will be described in detail.

[(A) ingredient]

The component (A) in the processing oil is a dicarboxylic acid having a sulfide structure, and imparts lubricity. The component (A) is preferably a dicarboxylic acid having a structure represented by the following formula (1) from the viewpoint of lubricity.

HOOC-R ¹ -S _n -R ² -COOH...(1)

Here, R ¹ and R ² are a hydrocarbon group having 1 or more and 5 or less carbon atoms, and n is an integer of 1 or more and 8 or less. When the carbon number of R ¹ or R ² is 6 or more, the water solubility is lowered.

The total carbon number in the dicarboxylic acid of the above formula (1) is 4 or more and 12 or less, and is preferably 6 or more and 10 or less from the viewpoint of water solubility and lubricity. In the case of R ¹ and R ² , an alkylene group is preferred, and examples thereof include a methylene group, an ethylidene group, a methyl group-extended ethyl group, a propyl group and a butyl group. From the viewpoint of water solubility and lubricity, it is preferable to extend ethyl.

Moreover, if n is 9 or more, the structure becomes unstable and decomposes. Hey. Therefore, n is preferably 6 or less, more preferably 2 or less, still more preferably 1.

Examples of such a dicarboxylic acid include thiodipropionic acid, dithiodipropionic acid, sulfur diacetic acid, thiodisuccinic acid, dithio diacetic acid, and dithiodibutyric acid.

The blending amount of the component (A) is preferably 0.1% by mass or more and 14% by mass or less based on the total amount of the raw material liquid, more preferably 1% by mass or more and 10% by mass or less, and 2% by mass or more and 5% by mass or less. good. When the amount of the component (A) is too large, the rust resistance may be lowered when the stock solution is diluted with water.

[(B) ingredients]

The component (B) in the processing oil is a monocarboxylic acid, which contributes to an improvement in lubricity and wear resistance. In the case of such a monocarboxylic acid, a so-called long-chain carboxylic acid is preferred, and a compound represented by the following formula (2) is preferred.

R ³ -COOH...(2)

Here, R ³ is a hydrocarbon group having 11 or more carbon atoms. In the case of a hydrocarbon group, it may be a straight chain or a branch, and may be saturated or unsaturated. From the viewpoint of lubricity and abrasion resistance, pine oil fatty acid is preferred.

As the long-chain carboxylic acid, lauric acid, stearic acid, oleic acid, linoleic acid, linoleic acid, sinapic acid, palmitic acid, ricinoleic acid, and hydroxy fatty acid (for example, ricinoleic acid, 12) may be specifically mentioned. - hydroxystearic acid, etc.), arachidic acid, behenic acid, beeswavic acid, isostearic acid, soybean oil fatty acid extracted from fats and oils, coconut oil fatty acid, rapeseed oil fatty acid, and pine oil fatty acid (C18).

The blending amount of the component (B) is preferably 1% by mass or more based on the total amount of the processing oil from the viewpoint of lubricity and abrasion resistance at a general dilution ratio. And 20% by mass or less.

This processing oil is obtained by mixing the above-mentioned components (A) and (B) in water to prepare a stock solution, and does not contain polyalkylene glycol (PAG). However, in the case of impurities, slight mixing of the extent to which the effects of the present invention are not impaired is allowed in the practice of the present invention.

The processing oil (stock solution) is preferably a total amount of the component (A) and the component (B) in an amount of 4% by mass or more and 40% by mass or less based on the total amount of the processing oil, and a desirable blending amount is 5% by mass. The above and 15% by mass or less.

When the blending amount of the total of the component (A) and the component (B) is less than 4% by mass, the dilution ratio of water when the processing oil is used in the field is too high, and in this case, the lubricity may be lowered (the friction coefficient is increased). Hey. On the other hand, when the blending amount of the total of the component (A) and the component (B) exceeds 40% by mass, the stability of the stock solution is lowered. Here, the stability of the stock solution means loss of uniformity of the stock solution due to phase separation, insolubilization of solids, precipitation, and the like.

The ratio of the raw liquid preparation water is preferably 20% by mass or more and 75% by mass or less based on the total amount of the processing oil. When the ratio of water is less than 20% by mass, the components (A) and (B) are hardly dissolved, and the preparation of the stock solution becomes more complicated. In addition, when the ratio of the raw liquid preparation water exceeds 75% by mass, the storage amount and the transportation amount of the raw liquid are excessively large, and the handleability is lowered.

In addition, the processing oil (stock solution) may be used in its original concentration, but it is preferably diluted with water to a ratio of 2 times or more and 200 times or less, more preferably 5 times or more and 100 times or less (capacity ratio) for cooling for metal processing. Use of the agent.

[Other ingredients]

It is suitable to further blend non-ionic interfacial activity in the processing oil. The agent is used as the component (C). By blending such a surfactant, the wettability of the processing oil can be improved, and the processing oil can be more easily penetrated between the grindstone and the material to be cut.

As the component (C), an acetylene glycol-based surfactant is particularly preferable from the viewpoint of the effect. As the acetylene glycol-based surfactant, for example, acetylene glycol or an alkylene oxide adduct described in JP-A-2011-12249 can be suitably used. For example, it is preferably an acetylene glycol EO adduct. As a commercial item, Dynol 604, Surfynol 420, Surfynol 465, etc. by Air Products and Chemicals, Inc. are mentioned.

The blending amount of the component (C) is preferably 0.1% by mass or more and 20% by mass or less based on the total amount of the raw material liquid, and more preferably 1% by mass or more and 10% by mass or less. When the blending amount of the component (C) is too large, the defoaming property at the time of dilution deteriorates.

It is preferred to further incorporate an alkanolamine as the component (D) in the processing oil. The alkanolamine reacts with the above component (A) or (B) to form an alkanolamine carboxylate, which further improves lubricity. Further, the alkanolamine can also function as a rust preventive.

The alkanolamine is not particularly limited, and a combination of primary, secondary and tertiary amines can be used. However, if only a primary amine is used, since the volatility of the amine is high, there is a fear that the working environment is deteriorated in terms of odor. Therefore, when a primary amine is used, it is preferably used in combination with a secondary amine or a tertiary amine. Further, from the viewpoint of odor, a tertiary amine is preferred.

Specific examples of the primary amine include, for example, 1-amino-2-propanol, 2-amino-2-methyl-1-propanol, 1-amino-2-butanol, and 2-amine. Keto-1-propanol, 3-amino-2-butanol, and the like. In this case, in the point of preventing rust of iron, It is especially preferred to use 1-amino-2-propanol and 2-amino-2-methyl-1-propanol. In the present processing oil, one type of the above-mentioned components may be used, or two or more types may be used.

Specific examples of the secondary amine include, for example, diethanolamine, di(n-propanol)amine, diisopropanolamine, N-methylmonoethanolamine, N-ethylmonoethanolamine, N-cyclomonoethanolamine, N-n-propyl monoethanolamine, N-isopropyl monoethanolamine, N-n-butyl monoethanolamine, N-isobutyl monoethanolamine, and N-tert-butyl butyl monoethanolamine. In the present processing oil, one type of the above-mentioned components may be used, or two or more types may be used.

Specific examples of the tertiary amine include N-methyldiethanolamine, N-ethyldiethanolamine, triethanolamine, N-cyclohexyldiethanolamine, N-n-propyldiethanolamine, and N-isopropyldiamine. Ethanolamine, N-n-butyldiethanolamine, N-isobutyldiethanolamine, and N-tert-butyldiethanolamine. These components may be used alone or in combination of two or more.

The blending amount of the component (D) is preferably 20% by mass or more and 55% by mass or less based on the total amount of the processing oil (stock solution). When the blending amount of the component (D) is less than 20% by mass, the dilution ratio of water when the processing oil is used in the field is too high, and in this case, there is a fear that the rust preventing property is lowered. On the other hand, when the blending amount of the component (D) exceeds 55 mass%, the stability of the stock solution is lowered.

Here, in order to improve the rust preventive property, the sulfur-free carboxylic acid and the component (D) are preferably used as a rust preventive. Such a carboxylic acid is preferably from the viewpoint of defoaming property and hard water stability, and the following is preferred: carbonic acid number 8 to 10 such as lanolinic acid, citric acid, isophthalic acid, trimethylhexanoic acid, and neodymium. a monocarboxylic acid such as an acid or a citric acid; or a dicarboxylic acid having a carbon number of 9 to 12 such as azelaic acid, undecanedioic acid, sebacic acid or dodecanedioic acid.

In particular, when the above-mentioned trimethylhexanoic acid is used to dilute the processing oil (stock solution) with water, the effect of reducing the solid content of the liquid surface (hard water stability) is excellent.

Further, in the case of the alkyl group constituting the main chain of the carboxylic acid, it is preferred to have a branched structure in terms of corrosion resistance. When a dibasic acid is used as the carboxylic acid, it has excellent rust preventive properties when used as a salt, and from the viewpoint of stability of the stock solution (difficult to be insolubilized), it is preferred to use a dibasic acid in combination with a monobasic acid.

Further, various known additives may be appropriately blended in the processing oil within a range not inhibiting the object of the present invention. For example, extreme pressure agents, oily agents, bactericides (preservatives), metal inerting agents, antifoaming agents, and the like.

Examples of the extreme pressure agent include a sulfur-based extreme pressure agent, a phosphorus-based extreme pressure agent, an extreme pressure agent containing sulfur and a metal, and an extreme pressure agent containing phosphorus and a metal. These extreme pressure agents may be used alone or in combination of two or more. The extreme pressure agent may be any one which contains a sulfur atom or a phosphorus atom in the molecule and exhibits load resistance or abrasion resistance. Examples of the sulfur-containing extreme pressure agent in the molecule include sulfurized fats and oils, sulfurized fatty acids, sulfurized esters, sulfurized olefins, dihydrocarbyl polysulfides, thiadiazole compounds, alkyl thiamine methyl sulfonium compounds, and the like. A compound, a sulfonium compound, a dialkyl thiodipropionate compound or the like. When the extreme pressure agents are blended in the raw liquid, it is preferred that the blending amount of the extreme pressure agents is 0.05% by mass or more and 0.5 mass based on the final diluent (coolant) from the viewpoint of the blending effect. % below.

The oily agent may, for example, be an aliphatic compound such as an aliphatic alcohol or a fatty acid metal salt, an ester compound such as a polyol ester, a sorbitol ester or a glyceride. When the oily agent is blended in the raw liquid, it is preferred that the blending amount of the oily agents is 0.2% by mass on the basis of the coolant from the viewpoint of the blending effect. The above and 2% by mass or less.

As the bactericide, for example, 2-mercaptopyridine-1-oxide salt can be mentioned. Specific examples thereof include sodium 2-mercaptopyridine-1-oxide, zinc bis(2-dimercaptopyridine-1-oxide), and bis(1-hydroxy-1H-pyridine-2-thiosulfate-O, S ) Copper and so on. When the sterilizing agent is blended in the raw material, the blending amount of the sterilizing agent is preferably 0.01% by mass or more and 5% by mass or less based on the amount of the coolant, from the viewpoint of the blending effect.

Examples of the metal inerting agent include benzotriazole, a benzotriazole derivative, an imidazoline, a pyrimidine derivative, and a thiadiazole. These may be used alone or in combination of two or more. When the metal inerting agent is blended in the raw liquid, the blending amount of the metal inerting agent is preferably from 0.01% by mass to 3% by mass based on the coolant, from the viewpoint of the blending effect.

Examples of the antifoaming agent include methyl polyoxyphthalic acid, fluoropolyoxygenated oil, polyacrylate, and the like. When the antifoaming agent is blended in the raw liquid, it is preferred that the blending amount of the antifoaming agent is 0.004% by mass or more and 0.08% by mass or less based on the coolant.

The water-soluble metal working oil of the present invention can be suitably diluted in water according to the purpose of use thereof, so as to be suitable for use in grinding or cutting, and various metals such as grinding, spin forming, drawing, rolling, and the like. Processing field. Further, in terms of grinding, cylindrical grinding, internal grinding, surface grinding, centerless grinding, tool grinding, honing, super finishing, and special surface grinding are mentioned. Processing (such as thread wheel grinding, gear grinding, cam grinding, roller grinding).

In the present invention, for example, a composition which is defined as "a composition in which the components (A) and (B) are blended" is not only a "component containing the components (A) and (B)" but also includes At least one of the components (A) and (B) is changed to a composition containing a modified substance obtained by modifying the component, and a composition of a reaction product containing a reaction between the component (A) and the component (B) Things."

Example

The invention is further illustrated by the following examples, but the invention is not limited by the examples.

[Examples 1, 2, and Comparative Examples 1 to 6]

After the water-soluble metal working oil (stock solution) was prepared according to the blending formula shown in Table 1, each stock solution was diluted to 20 times (volume) with tap water to obtain each test oil. For each test oil, a block-on-ring test was performed to evaluate lubricity and wear resistance. The test conditions and evaluation items (evaluation methods) are as follows. The results are shown in Table 1.

<Block to ring test>

Testing machine: block-to-loop testing machine (manufactured by B.E. Marubishi Co., Ltd.)

Load: 100N

Number of rotations: 500 rpm (53 m/min)

Time: 10min

Ring test piece: SAE 4620STEEL

Block test piece: S45C

<assessment item (evaluation method)>

‧Lubricity

From the friction (N) and evaluated according to the following criteria.

A: 13.5N or less

B: More than 13.5N

‧ wear resistance

The width of the wear scar (μm) was evaluated and evaluated according to the following criteria.

A: 1100 μ m or less

B: more than 1100 μ m

[Table 1]

1) Pine oil fatty acid (C18)

2) HO(EO) _8.5 -(PO) _30.2 -(EO) _8.5 H: Sanyo Chemical System

3) HO(EO) _13.2 -(PO) ₃₀ -(EO) _13.2 H: Sanyo Chemical System

4) CH ₃ O(PO)a((EO)b/(PO)c)(PO)dH: Blember LUB82 manufactured by Sanyo Chemical Co., Ltd.

5) Pentaerythritol polyoxyethylene ether: PNT-60U made of Japanese emulsifier

6) Acetylene glycol-based surfactant: Mixing Dynol 604, Surfynol 420 and Surfynol 465 manufactured by Air Products and Chemicals, Inc.

7) Other components: (30% by mass aqueous solution of polyethylenimine (molecular weight 1000): 0.3% by mass, benzotriazole: 1.0% by mass, 35 mass% aqueous solution of benzisothiazoline: 0.2% by mass, pyridine sulfur Sodium ketone: 0.2% by mass, polyfluorene-based defoamer: 0.4% by mass)

[evaluation result]

The coolant obtained by diluting the stock solutions of Example 1 and Example 2 is blended with the components (A) and (B) of the present invention and does not contain PAG, and therefore has excellent lubricity and abrasion resistance.

On the other hand, the coolant obtained by diluting the stock solutions of Comparative Examples 1 to 6 lacks either of the components (A) and (B) or contains PAG, so that the lubricant property and the abrasion resistance cannot be achieved.

Claims (10)

A water-soluble metal working oil characterized in that it is blended with (A) a sulfide-containing dicarboxylic acid and (B) a monocarboxylic acid, and does not contain a polyalkylene glycol. The water-soluble metal working oil according to claim 1, wherein the component (A) is a compound of the following formula (1): HOOC-R ¹ -S _n -R ² -COOH (1) (R ¹ and R ² respectively The hydrocarbon group is independently a carbon number of 1 or more and 5 or less, and n is an integer of 1 or more and 8 or less. The water-soluble metal working oil according to claim 1, wherein the blending amount of the component (A) is 0.1% by mass or more and 14% by mass or less based on the total amount of the processing oil. The water-soluble metal working oil according to claim 1, wherein the component (B) is a compound of the following formula (2): R ³ -COOH (2) (R ³ is a hydrocarbon group having 11 or more carbon atoms). The water-soluble metal working oil according to claim 1, wherein the blending amount of the component (B) is 1% by mass or more and 20% by mass or less based on the total amount of the processing oil. The water-soluble metal working oil of claim 1, further comprising (C) an acetylene glycol-based surfactant. The water-soluble metal working oil according to claim 6, wherein the blending amount of the component (C) is 1% by mass or more and 15% by mass or less based on the total amount of the processing oil. The water-soluble metal working oil according to claim 1, wherein the water-soluble metal working oil is a raw liquid in which 15% by mass or more and 75% by mass or less of water is blended. A coolant for metal working, characterized in that the water-soluble metal working oil according to any one of Claims 1 to 8 is diluted with water by a factor of 2 or more and 200 times or less (capacity). The coolant for metal working according to claim 9, wherein the coolant for metal working is for grinding.