JP2021147507A - Metalworking oil composition - Google Patents

Abstract

To provide a metalworking oil composition.SOLUTION: The present invention relates to a metalworking oil composition, comprising: (a1) an ester of a fatty acid and a linear aliphatic monoalcohol; (a2) a base oil other than the component (a1); and (b) a pour-point depressant containing a sulfurized oil, wherein a content of the component (a1) is within a range from 20 to 75 wt.% in terms of the total amount of the composition.SELECTED DRAWING: None

Description

The present invention relates to a metalworking oil composition, for example, a water-insoluble metalworking oil composition suitable for cutting or grinding.

As the metalworking oil composition, those in which mineral oil or synthetic oil is used as a base oil and various additives are blended therein are widely used. The metalworking oil composition is required to have a high flash point not only in terms of processing performance and wear resistance, but also in terms of improving the working environment by reducing fire risk and oil smoke. As a metalworking oil composition having a high flammability, a metalworking oil composition based on an ester compound is known, but the metalworking oil containing an ester compound causes precipitates at a low temperature and becomes fluid at a low temperature. There was a problem of inferiority. In order to improve such low temperature characteristics, as ester compounds, polyhydric alcohol esters (Patent Document 1: JP-A-2008-163115, Patent Document 2: International Publication No. WO2015 / 107828) and branched esters (Patent Document 3: Patent Document 3: A metalworking oil using Japanese Patent Application Laid-Open No. 2014-189555) has been proposed, but such an ester compound is generally expensive, and there is a problem that the production cost of the metalworking oil is high.

Japanese Patent Application Laid-Open No. 2008-163115 International Publication No. WO2015 / 107828 Japanese Unexamined Patent Publication No. 2014-189555

Under such circumstances, a new metalworking oil composition is desired.

One form of the present invention comprises the following components:
(A1) Esters of fatty acids and linear aliphatic monoalcohols,
(A2) With base oils other than the component (a1) above,
(B) A pour point lowering agent containing sulfide oil and fat,
A metalworking oil composition containing the above component (a1), wherein the content of the component (a1) is in the range of 20 to 75% by weight based on the total amount of the composition.

According to the present invention, there is provided a metalworking oil composition having excellent properties such as low temperature properties and friction properties while using an inexpensive linear monoester.

Hereinafter, embodiments of the present invention will be described in detail. The present invention is not limited to the following embodiments, and can be arbitrarily modified and implemented without departing from the gist thereof.
The upper and lower limits of the numerical range described herein can be arbitrarily combined. For example, when "A to B" and "C to D" are described, the range of "A to D" and "C to B" is also included in the range as a numerical range in the present invention. Further, unless otherwise specified, the numerical range "lower limit value to upper limit value" described in the present specification means that it is equal to or more than the lower limit value and equal to or less than the upper limit value.

One embodiment of the present invention relates to a metalworking oil composition (hereinafter, also referred to as “composition”). The composition according to the present embodiment is a pour point lowering agent containing (a1) an ester of a fatty acid and a linear aliphatic monoalcohol, (a2) a base oil other than the above (a1) component, and (b) a sulfide oil and fat. The content of the component (a1) is in the range of 20 to 75% by weight based on the total amount of the composition. The composition according to this embodiment further contains (c) other additives, if necessary. Hereinafter, each component contained in the composition according to the present embodiment will be described in order.

[Base oil]
The base oil includes (a1) an ester of a fatty acid and a linear aliphatic monoalcohol, and (a2) a base oil other than the component (a1) (hereinafter, also referred to as “other base oil”).

(A1) Ester of fatty acid and linear aliphatic monoalcohol The fatty acid constituting the ester of fatty acid and linear aliphatic monoalcohol is not particularly limited, but has an excellent balance between viscosity and ignition point, and therefore has an excellent carbon number of carbon atoms. Fatty acids of 6 or more and 26 or less are preferable. Examples of such fatty acids include hexanoic acid, heptanic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid (palmitic acid), and 9-hexadecenoic acid. , Heptadecanic acid, octadecanoic acid (stearic acid), isostearic acid, 9-octadecenoic acid (oleic acid, elaidic acid), linoleic acid, linoleic acid, nonadecanic acid, eicosanoic acid (arachidic acid), docosanoic acid (bechenic acid), etc. Can be mentioned. Among these fatty acids, those having 8 or more and 22 or less carbon atoms are more preferably used, and those having 10 or more and 18 or less carbon atoms are further preferably used. Particularly preferably, those containing at least one of oleic acid, stearic acid, and palmitic acid are preferable from the viewpoint of availability and cost, and those containing oleic acid are more preferable. Fatty acids (units) may be used alone or in combination.

The linear aliphatic monoalcohol constituting the ester of the fatty acid and the linear aliphatic monoalcohol is not particularly limited, but is a linear aliphatic monoalcohol having 6 or more and 20 or less carbon atoms because of its excellent balance between viscosity and ignition point. Saturated monoalcohol or linear aliphatic unsaturated monoalcohol is preferred. Specifically, 1-hexanol, 1-heptanol, 1-octanol, 1-nonanol, 1-decanol, 1-undecanol, 1-dodecanol, 1-tridecanol, 1-tetradecanol, 1-pentadecanol, 1 Linear aliphatic saturated monoalcohols such as −hexadecanol, 1-octadecanol, 1-nonadecanol, 1-eicosanol; hexenol, heptanol, octenol, nonenol, desenol, undecenol, dodecenol, tridecenol, tetradecenol, pentadecenol, hexadecenol , Heptanol, octadecanol, nonadecanol, eicosenol and other linear aliphatic unsaturated monoalcohols. Among these linear aliphatic monoalcohols, linear aliphatic monoalcohols having 8 or more and 18 or less carbon atoms (saturated monoalcohol or unsaturated monoalcohol) are more preferably used, and directly having 12 or more and 15 or less carbon atoms. Chain aliphatic monoalcohols (saturated monoalcohols or unsaturated monoalcohols) are more preferably used, and linear saturated monoalcohols having 12 or more and 15 or less carbon atoms are particularly preferably used from the viewpoint of oxidative stability. The linear aliphatic monoalcohol (unit) may be used alone or in combination.

Among the above-mentioned esters of fatty acids and linear aliphatic monoalcohol, linear aliphatic monoalcohol (saturated monoalcohol or unsaturated monoalcohol) having 12 or more and 15 or less carbon atoms has an excellent balance between low viscosity and high flammability. A fatty acid containing at least one of monoalcohol, preferably saturated monoalcohol) and a fatty acid having 10 or more and 18 or less carbon atoms (preferably oleic acid, stearic acid, and palmitic acid, more preferably a fatty acid containing oleic acid, still more preferably. An ester with a fatty acid in which 50% by weight or more of the fatty acid is oleic acid, particularly preferably oleic acid) is preferable.

The ester of the fatty acid and the linear aliphatic monoalcohol can be obtained by the dehydration reaction between the fatty acid and the linear aliphatic monoalcohol, but the ester exchange method is not limited to the dehydration reaction between the fatty acid and the linear aliphatic monoalcohol. You may use it.

The blending amount of the component (a1) is in the range of 20 to 75% by weight based on the total amount of the composition. If it exceeds 75% by weight, the pour point of the composition may rise and the low temperature characteristics may deteriorate. From the viewpoint of low temperature characteristics, the blending amount of the component (a1) is preferably 70% by weight or less, and more preferably 60% by weight or less. On the other hand, when the component (a1) is less than 20% by weight, the component (a1) cannot be blended in a sufficient amount, and the cost merit is reduced. From the viewpoint of high flash point, the blending amount of the component (a1) is preferably 25% by weight or more, and more preferably 30% by weight or more. Further, since the component (a1) is excellent in availability and cost, there is an advantage that the production cost of the composition can be reduced by increasing the blending amount of the component (a1). In one embodiment, the blending amount of the component (a1) is preferably 25% by weight or more and 70% by weight or less, and more preferably 30% by weight or more and 60% by weight or less based on the total amount of the composition.

The flash point of the component (a1) is preferably 200 ° C. or higher, more preferably 230 ° C. or higher, and even more preferably 250 ° C. or higher. When the flash point of the component (a1) is 200 ° C. or higher, it becomes easy to obtain a composition having a high flash point.
In the present specification, the flash point means a value measured by the Cleveland Opening Method (COC) method according to JIS K 2265-4: 2007.

The kinematic viscosity of the component (a1) at 40 ° C. is preferably 5 to ^{30 mm 2 / s.} When the 40 ° C. kinematic viscosity of the component (a1) is 5 mm ² / s or more, sufficient lubricity can be maintained during metal processing, the flash point can be controlled high, and the generation of oil smoke and mist can be suppressed. .. When the 40 ° C. kinematic viscosity of the component (a1) is 30 mm ² / s or less, the processability and permeability are excellent, and the consumption amount (loss amount) can be reduced. (A1) 40 ° C. kinematic viscosity of component, from the viewpoint of excellent balance of viscosity and flash point, more preferably 8~25mm ² / s, more preferably from 10 to 20 mm ² / s.
In the present specification, the kinematic viscosity at a predetermined temperature means a value measured according to JIS K2283: 2000.

(A2) Other base oils Other base oils are not particularly limited, and examples thereof include mineral oils and synthetic oils other than the above-mentioned component (a1). The other base oil may be only mineral oil, only synthetic oil, or a combination of one or more mineral oils and one or more synthetic oils.

As the mineral oil, any mineral oil conventionally used as a base oil for metalworking oil can be appropriately selected and used. For example, distillate obtained by atmospheric distillation of paraffin-based crude oil, intermediate-based crude oil, or naphthenic-based crude oil or residual oil of atmospheric distillation under reduced pressure, or refining this according to a conventional method. Examples of the refined oil obtained by, for example, solvent refined oil, hydrogenated refined oil, dewaxed treated oil, white clay treated oil and the like can be mentioned. Mineral oil may be used alone or in combination of two or more.

As the synthetic oil, any synthetic oil conventionally used as a base oil for metalworking oil can be appropriately selected and used. For example, as the synthetic oil, at least one selected from an ester compound other than the component (a1), a naphthen compound, a polyolefin compound, an aromatic compound, an ether compound, and a glycol compound can be mentioned. The synthetic oil may be used alone or in combination of two or more. Among these synthetic oils, ester compounds other than the component (a1) are preferably used from the viewpoint of low temperature characteristics and high flash point.

The ester compound other than the component (a1) is not particularly limited, but from the viewpoint of obtaining a composition having a low viscosity and a high flammability, an ester of a fatty acid and a polyhydric alcohol or an ester of a fatty acid and a branched aliphatic monoalcohol may be used. It can be preferably used.

The polyhydric alcohol constituting the ester of the fatty acid and the polyhydric alcohol is not particularly limited, but an alcohol having a divalent to 10-valent value is preferable, an alcohol having a divalent to a hexavalent value is more preferable, and an alcohol having a divalent to hexavalent value is more preferable. Alcohols from valence to pentavalent. Examples of such polyhydric alcohols include diols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, and neopentyl glycol; triols such as glycerin, trimethylolethane, and trimethylolpropane; and pentaerythritol. Tetraol; Pentaol such as sorbitol can be mentioned. Of these, trimethylolpropane, pentaerythritol, neopentyl glycol, and glycerin are preferable from the viewpoint of thermal stability and oxidation resistance stability. The polyhydric alcohol (unit) may be used alone or in combination.

The branched aliphatic monoalcohol constituting the ester of the fatty acid and the branched aliphatic monoalcohol is not particularly limited, but a branched saturated monoalcohol or a branched unsaturated monoalcohol is preferable from the viewpoint of excellent balance between viscosity and ignition point. For example, ethylhexanol, butyloctanol, pentylnonanol, hexyldecanol, heptylundecanol, octyldodecanol, methylheptadecanol, isotridecanol and the like can be mentioned. Among them, from the viewpoint of low viscosity and high flash point, a branched aliphatic monoalcohol having 10 to 18 carbon atoms is preferably used, more preferably a branched aliphatic monoalcohol having 12 to 15 carbon atoms, and still more preferably an isotridecyl alcohol. Be done. The branched aliphatic monoalcohol (unit) may be used alone or in combination.

As the fatty acid constituting the ester of the fatty acid and the polyhydric alcohol or the ester of the fatty acid and the branched aliphatic monoalcohol, those exemplified as the fatty acid constituting the component (a1) can be similarly used.

Among the ester compounds other than the above component (a1), oleic acid esters such as branched aliphatic monoalcohol oleic acid esters and polyhydric alcohols oleic acid esters having 12 to 15 carbon atoms are preferable.

As the naphthenic compound, a compound having a ring selected from a cyclohexane ring, a bicycloheptane ring and a bicyclooctane ring is preferably mentioned.
Preferred examples of the polyolefin compound include α-olefin homopolymers and copolymers (for example, ethylene-α-olefin copolymers) and hydrides thereof.
Examples of the aromatic compound include alkyl aromatic compounds such as alkylbenzene and alkylnaphthalene.
Examples of the ether compound include polyphenyl ether and the like.
Examples of glycol-based compounds include polyglycol oils such as polyoxyalkylene glycol.

Among them, (a2) and other base oils preferably contain at least one of an ester compound other than the mineral oil and the component (a1), and the ester of the mineral oil and the fatty acid and the branched aliphatic monoalcohol, and the fatty acid and the polyhydric alcohol. It is more preferable to contain at least one of the esters of and, and even more preferably to contain at least one of the esters of the mineral oil and the fatty acid and the branched aliphatic monoalcohol.
In one embodiment, (a2) other base oils include mineral oils. By blending the mineral oil together with the component (a1), the low temperature characteristics of the composition can be improved.
In one embodiment, the other base oil (a2) contains a fatty acid and an ester compound other than the component (a1). By blending an ester compound other than the component (a1) together with the component (a1), the low temperature characteristics and friction characteristics of the composition can be improved.
In one embodiment, (a2) the other base oil comprises an ester of a fatty acid and a branched aliphatic monoalcohol. By blending an ester of a fatty acid and a branched aliphatic monoalcohol together with the component (a1), the low temperature characteristics and frictional characteristics of the composition can be further improved.

The blending amount of the component (a2) is not particularly limited, but is preferably 20% by weight or more, more preferably 30% by weight or more, and further preferably 40% by weight or more based on the total amount of the composition. Within such a range, the ratio of the component (a1) does not become too high, and the low temperature characteristics can be improved. The component (a2) is preferably 60% by weight or less, more preferably 55% by weight or less, and further preferably 50% by weight or less based on the total amount of the composition. Within such a range, the component (a1) can be blended in a sufficient amount, and a composition having a high flash point and excellent production cost can be obtained. In one embodiment, the blending amount of the component (a2) is 20% by weight or more and 60% by weight or less, preferably 30% by weight or more and 55% by weight or less, and more preferably 40% by weight or less based on the total amount of the composition. It is 50% by weight or less.

The content of the base oil (the total of the components (a1) and (a2)) is not particularly limited, but is preferably 60 to 99.5% by weight, more preferably 70 to 97% by weight, based on the total amount of the composition. More preferably, it is 80 to 95% by weight.

Although 40 ° C. kinematic viscosity of the base oil is not particularly limited, it is preferably from 1 to 50 mm ² / s, more preferably 5 to 40 mm ² / s, further preferably 7~30mm ² / s .. Is more preferable.
The flash point of the base oil is preferably 200 ° C. or higher, more preferably 230 ° C. or higher, still more preferably 250 ° C. or higher from the viewpoint of handling safety. The higher the flash point, the more preferable it is from the viewpoint of handling safety.

[Pour point depressant]
The pour point lowering agent includes (b) sulfide oil and fat. By blending the sulfide oil and fat, excellent low temperature characteristics and friction characteristics can be imparted to the composition. Surprisingly, the present inventors have found that the pour point can be lowered in addition to the frictional properties by blending the sulfide oil and fat together with the component (a1). Such a pour point lowering effect of sulfide fats and oils was not confirmed in other sulfides and fats and oils such as powdered sulfur and polysulfide.

Sulfurized fats and oils are obtained by reacting sulfur or sulfur-containing compounds with fats and oils (lard oil, vegetable oil, whale oil, fish oil, etc.). , Sulfurized soybean oil, and sulphurized oils and fats derived from vegetable oils such as sulphurized rice bran oil; sulphurized fats and oils derived from whale oil; and sulphurized fats and oils derived from fish oil. As the sulfide fat and oil, a commercially available product may be used, or a synthetic product may be obtained.

The sulfide oil and fat preferably has a low viscosity and a high flash point.
By using a low-viscosity sulfide oil / fat, it is possible to suppress an increase in the viscosity of the metalworking oil composition. Specifically, 40 ° C. kinematic viscosity of sulfurized fats is preferably less 1,000mm ² / s, more preferably less 700 mm ² / s, more preferably not more than 500 mm ² / s. The lower the viscosity of the sulfide fat and oil, the more preferable.
The flash point of the sulfide oil and fat having a high flash point is preferably 170 ° C. or higher, more preferably 200 ° C. or higher, still more preferably 250 ° C. or higher, from the viewpoint of safety and handling under the Fire Service Act. The higher the flash point of the sulfide oil and fat, the more preferable.

From the viewpoint of low temperature characteristics and the pour point lowering effect, the sulfide fat and oil preferably has a pour point of −10 ° C. or higher, more preferably −5 ° C. or higher, and even more preferably 0 ° C. or higher. Further, from the viewpoint of avoiding deterioration of low temperature characteristics due to the addition of a large amount of sulfide fat and oil, the pour point of the sulfide fat and oil is preferably 30 ° C. or lower, more preferably 25 ° C. or lower, and 20 ° C. or lower. Some are even more preferred. In one embodiment, the pour point of the sulfide oil is preferably −10 ° C. or higher and 30 ° C. or lower, more preferably −5 ° C. or higher and 25 ° C. or lower, and further preferably 0 ° C. or higher and 20 ° C. or lower.
In the present specification, the pour point means a value measured according to JIS K 2269 (pour point of crude oil and petroleum products and cloud point test method).

The sulfur content of the sulfide fat and oil is not particularly limited, but generally 5 to 30% by weight is preferably used.

The acid value of the sulfide fat and oil is not particularly limited, but generally 0.5 to 4 mgKOH / g is preferable.
In the present specification, the acid value means a value measured according to JIS K2501: 2003 (potentiometric titration method).
The specific gravity of the sulfide fat and oil is not particularly limited, but generally 0.95 to 1.0 g / cm ³ at 15 ° C. is preferable.
In the present specification, the specific gravity means a value measured according to JISZ8804: 2012 at 15 ° C.

The content of sulfide fats and oils is preferably 0.1 to 5% by weight based on the total amount of the composition. Within such a range, the low temperature characteristics and frictional characteristics of the composition can be improved. By blending the sulfide oil and fat, the pour point is lowered to improve the low temperature characteristics, and the friction coefficient is lowered to impart good lubricity. On the other hand, if the content of the sulfide oil and fat becomes too large, the pour point of the metalworking oil composition tends to decrease due to the high pour point of the sulfide oil and fat itself. In terms of low temperature characteristics, the content of sulfide fats and oils is more preferably 0.1 to 3% by weight, further preferably 0.5 to 2% by weight, and particularly preferably 0.5 to 1% by weight. Is. In one embodiment, the content of the sulfide oil is preferably 0.1% by weight or more, more preferably 0.5% by weight or more. In one embodiment, the content of the sulfide oil is preferably 5% by weight or less, more preferably 3% by weight or less, still more preferably 2% by weight or less, or 1% by weight or less.

The composition may contain a pour point lowering agent other than (b) sulfide oil and fat, but is preferably not contained. (B) The content of the pour point lowering agent other than the sulfide oil and fat is preferably 3% by weight or less, more preferably 2% by weight or less, still more preferably 1% by weight or less, and particularly preferably 0.1% by weight or less. ..

[Component (c): Other Additives]
The metalworking oil composition contains additives such as an abrasion resistant agent, an antioxidant, a rust preventive, a metal inactivating agent, and a defoaming agent as necessary, as long as the effects of the present embodiment are not impaired. can do. The total content of these other components is not particularly limited, but is, for example, about 0 to 20% by weight based on the total amount of the composition.

(Abrasion resistant agent)
Examples of the abrasion resistant agent include zinc dithiophosphate (ZnDTP), zinc dithiocarbamate (ZnDTC), molybdenum oxydithiophosphate (MoDTP) and molybdenum oxydithiocarbamate (MoDTC). The preferable blending amount of the abrasion resistant agent is not particularly limited, but is about 0.01% by weight or more and 3% by weight or less based on the total amount of the composition.

(Antioxidant)
Examples of the antioxidant include amine-based antioxidants (diphenylamines, naphthylamines), phenol-based antioxidants, molybdenum-based antioxidants, sulfur-based antioxidants, phosphorus-based antioxidants, and the like. The antioxidant may be used alone or in combination of two or more. The content of the antioxidant is not particularly limited, but is, for example, about 0.05 to 7% by weight based on the total amount of the composition.

(anti-rust)
Examples of the rust preventive agent include fatty acids, alkenyl succinic acid half esters, fatty acid shavings, alkyl sulfonates, polyhydric alcohol fatty acid esters, fatty acid amides, oxidized paraffins, alkyl polyoxyethylene ethers and the like. The rust preventive may be used alone or in combination of two or more. The preferable blending amount of the rust preventive is not particularly limited, but is about 0.01% by weight or more and 3% by weight or less based on the total amount of the composition.

(Metal inactivating agent)
Examples of the metal inactivating agent include benzotriazole, triazole derivative, benzotriazole derivative, and thiadiazole derivative. The metal inactivating agent may be used alone or in combination of two or more. The content of the metal inactivating agent is not particularly limited, but is preferably 0.01 to 5% by weight based on the total amount of the composition.

(Defoamer)
Examples of the defoaming agent include silicone compounds such as dimethylpolysiloxane and polyacrylates. The defoaming agent may be used alone or in combination of two or more. The content of the defoaming agent is not particularly limited, but is about 0.01% by weight or more and 5% by weight or less based on the total amount of the composition.

The metalworking oil composition of the present embodiment may contain the above-mentioned component (a1), component (a2), component (b), and component (c), but the total content thereof exceeds 100% by weight. Make it not exist.
In one embodiment, the total content of component (a1), component (a2) and component (b) is preferably 80-100% by weight, more preferably 90-100% by weight based on the total weight of the metalworking oil composition. It is by weight%, more preferably 95 to 100% by weight.

The metalworking oil composition of one embodiment has, for example, the following composition with respect to the total weight (100% by weight) of the composition.
(A1) Ester of fatty acid and linear aliphatic monoalcohol 20 to 75% by weight (more preferably 25 to 70% by weight, still more preferably 30 to 60% by weight)
(A2) 20 to 60% by weight of base oil other than the component (a1) (more preferably 30 to 55% by weight, still more preferably 40 to 50% by weight).
(B) Sulfide fats and oils 0.1 to 5% by weight (more preferably 0.1 to 3% by weight, still more preferably 0.5 to 2% by weight)
(C) Other additives 0 to 20% by weight (more preferably 0 to 10% by weight)

[Characteristics of metalworking oil composition]
The metalworking oil composition preferably satisfies the three performances of low pour point, low coefficient of friction, and high flash point. More preferably, the metalworking oil composition satisfies the four performances of low pour point, low friction coefficient, high flash point and low viscosity.

The pour point of the metalworking oil composition is preferably −20 ° C. or lower, more preferably −25 ° C. or lower, and even more preferably −30 ° C. or lower, from the viewpoint of improving low temperature fluidity.

The metalworking oil composition preferably has a friction coefficient of 0.130 or less, preferably 0.125 or less, measured under the condition of an oil temperature of 30 ° C. by the pendulum type friction test method specified in JASO-M314-88. It is more preferably 0.120 or less, and particularly preferably 0.110 or less.

The flash point of the metalworking oil composition is preferably 200 ° C. or higher, more preferably 220 ° C. or higher, still more preferably 230 ° C. or higher, and particularly preferably 250 ° C. or higher from the viewpoint of handling safety. The higher the flash point, the more preferable it is from the viewpoint of handling safety.

Kinematic viscosity at 40 ° C. metalworking oil composition is excellent in processability and permeability, since it is possible to reduce the consumption (loss) is preferably ^{5~70mm 2 / s, 8~60mm 2 /} s Is more preferable, and 10 to 50 mm ² / s is even more preferable.

The composition of the present embodiment is a water-insoluble metal processing oil composition and can be used for metal processing. As a type of metal processing, it can be suitably used in various metal processing fields such as cutting, grinding, punching, polishing, drawing, drawing, rolling, etc., but cutting or grinding can be used. Preferably, it is suitably used as a cutting oil composition used for cutting a metal. The metal to be processed is not particularly limited, and examples thereof include iron-based materials such as stainless steel, alloy steel and carbon steel, aluminum alloys and copper alloys.

[Manufacturing method of metalworking oil composition]
The method for producing the lubricating oil composition of the present embodiment is not particularly limited. The method for producing a lubricating oil composition of one embodiment includes mixing the component (a1), the component (a2), the component (b) and, if necessary, the component (c). The component (a1), the component (a2), the component (b) and, if necessary, the component (c) may be blended by any method, and the order of blending and the method thereof are not limited.

Hereinafter, the present invention will be described in detail with reference to Examples, but the technical scope of the present invention is not limited thereto.

The physical characteristics of each raw material used in Examples and Comparative Examples and the metalworking oil composition of each Example and Comparative Example were evaluated by the methods shown below.
(1) Pour point Measured according to JIS K 2269 (pour point and cloudy point test method for crude oil and petroleum products).
(2) Friction coefficient Measured under the condition of oil temperature of 30 ° C. using the Soda type pendulum tester (Type II) in accordance with the pendulum type friction test method (Soda type pendulum test) specified in JASO-M314-88. bottom.
(3) Flash point The flash point was measured by the Cleveland open method (COC) method in accordance with JIS K 2265-4: 2007.
(4) 40 ° C. Dynamic Viscosity The kinematic viscosity at 40 ° C. (40 ° C. kinematic viscosity) was measured using a glass capillary viscometer according to JIS K2283: 2000.
(5) Acid value Measured according to JIS K2501: 2003 (potentiometric titration method).
(6) It means a value measured according to JISZ8804: 2012 at a specific gravity of 15 ° C.

[Examples 1 to 12, Comparative Examples 1 to 20]
The metalworking oil compositions of Examples and Comparative Examples were prepared by blending each of the components shown in Tables 1 to 3, and their physical properties were evaluated by the method described above.

Each component shown in Tables 1 to 3 is as follows.
Linear monoester 1: Oleic acid ester of a linear monoalcohol having 12 to 15 carbon atoms (40 ° C. kinematic viscosity: 13.7 mm ² / s, pour point: -7.5 ° C., flash point: 260 ° C.)
Branched monoester 1: Oleic acid ester mineral oil of isotridecyl alcohol 1: Paraffinic mineral oil (40 ° C kinematic viscosity: 12.5 mm ² / s, pour point: -37.5 ° C, flash point: 196 ° C)
Sulfide fats and oils 1: Lard-derived sulfide fats and oils (40 ° C. kinematic viscosity: 705.8 mm ² / s, pour point: 12.5 ° C.,
Flash point: 260 ° C., sulfur content: 6.88% by weight, acid value: 1.17 mgKOH / g, specific gravity: 0.968 g / cm ³ )
Sulfide fat 2: Lard-derived sulfide fat (40 ° C. kinematic viscosity: 900 mm ² / s, pour point: 12.5 ° C., flash point: 200 ° C., sulfur content: 11.4% by weight, acid value: 3.27 mgKOH / g, specific gravity: 0.982 g / cm ³ )
Fats and oils sulfide 3: Vegetable oil-derived sulfide fats and oils (40 ° C. kinematic viscosity: 350 mm ² / s, pour point: -7.5 ° C., flash point: 200 ° C., sulfur content: 11.0% by weight, acid value: 2.5 mgKOH / G, specific gravity: 0.984 g / cm ³ )
PMA: Polymethyl acrylate (weight average molecular weight Mw: 69,000)

As shown in Tables 1 to 3, an ester of a predetermined amount of fatty acid and a linear aliphatic monoalcohol (component (a1)), a base oil other than the component (a1) (component (a2)), and a sulfide oil (component). It was confirmed that the metal processing oil composition of the example containing (b)) had a high ignition point, a low pour point, a low coefficient of friction, and a low viscosity.

Examples 1 to 4 in which the content of the sulfide fat and oil is in the range of 0.1 to 3% by weight have a lower pour point and excellent low temperature characteristics as compared with Example 5 containing 5% by weight of the sulfide fat and oil. rice field. In particular, the compositions of Examples 2 and 3 in which the content of the sulfide fat and oil is in the range of 0.5 to 1% by weight are the sulfide fats and oils of Example 1 and 3% by weight or more containing 0.1% by weight of the sulfide fats and oils. It was confirmed that the pour point was lower and the low temperature characteristics were further improved as compared with Examples 4 and 5 including.
In the compositions of Examples 1 to 5, 8 to 12 in which the content of the component (a1) was 40% by weight or more, a composition having a higher flash point was obtained.
Example 12 in which the branched monoester is used together with the linear monoester has a lower coefficient of friction, is excellent in wear characteristics, and has a high flash point as compared with Example 3 in which mineral oil is used together with the linear monoester. It could be confirmed.
In Example 3 using the sulfide oil / fat 1 having a flash point of 200 ° C. or higher, a composition having a higher flash point was obtained as compared with Examples 10 and 11 having the same composition using the sulfide oils / fats 2 and 3. It was confirmed that it could be done.
Examples 3 and 10 using the sulfide oils and fats 1 and 2 having a pour point of −5 ° C. or higher have a lower pour point and low temperature characteristics as compared with Example 11 having an equivalent composition using the sulfide oil and fat 3. It was confirmed that it was excellent.

On the other hand, Comparative Example 1 having a large content of the component (a1) had a high pour point and was inferior in low temperature characteristics.
Comparative Example 2 containing no component (b) had a high pour point and a high coefficient of friction, and was inferior in low temperature characteristics and friction characteristics.
Comparative Examples 3 to 6, 13 to 15 in which PMA, which is a general pour point lowering agent, was blended instead of the component (b), had a high coefficient of friction and insufficient friction characteristics.
Comparative Examples 7 to 9 in which other sulfides were blended instead of the component (b) had a high pour point and were inferior in low temperature characteristics.
Comparative Examples 10 to 15 containing no component (a1) had a low flash point.

The metal processing oil composition of the present invention can be suitably used for metal processing such as cutting and grinding.

Claims (12)

(A1) Esters of fatty acids and linear aliphatic monoalcohols,
(A2) With base oils other than the component (a1) above,
(B) A pour point lowering agent containing sulfide oil and fat,
The metalworking oil composition, wherein the content of the component (a1) is in the range of 20 to 75% by weight based on the total amount of the composition. The composition according to claim 1, wherein the component (a1) is an ester of a fatty acid and a linear aliphatic monoalcohol having 12 to 15 carbon atoms. The composition according to claim 1 or 2, wherein the content of the sulfide oil / fat is 0.1% by weight or more and 5% by weight or less based on the total amount of the composition. The composition according to any one of claims 1 to 3, wherein the component (a2) contains at least one of an ester of a mineral oil and a fatty acid and a branched aliphatic monoalcohol. The composition according to any one of claims 1 to 4, wherein the content of the component (a2) is 20% by weight or more and 60% by weight or less based on the total amount of the composition. The composition according to any one of claims 1 to 5, wherein the composition has a pour point of −20 ° C. or lower. The composition according to any one of claims 1 to 6, wherein the composition has a kinematic viscosity at 40 ° C. of 5 mm ² / s or more and 70 mm ² / s or less and a flash point of 200 ° C. or more. The composition according to any one of claims 1 to 7, wherein the sulfide fat and oil has a flash point of 170 ° C. or higher. The composition according to any one of claims 1 to 8, wherein the sulfide fat and oil has a pour point in the range of −10 ° C. or higher. Any one of claims 1 to 9, wherein the composition has a friction coefficient of 0.130 or less measured under the condition of an oil temperature of 30 ° C. by the pendulum type friction test method specified in JASO-M314-88. The composition according to. The composition according to any one of claims 1 to 10, wherein the fatty acid in the component (a1) contains oleic acid. The composition according to any one of claims 1 to 11, which is a cutting oil composition.