Cutting oil composition

Abstract

The present invention relates to a cutting oil composition used in a wire-saw cutting process, which is composed of 50 to 95 wt% of a base oil represented by Chemical Formula 1, Chemical Formula 2, or Chemical Formula 3, 0.1 to 5 wt% of a chelating agent, 0.1 to 10 wt% of a thickener, 0.1 to 5 wt% of a dispersant, 1 to 20 wt% of an oiliness improver, and 1 to 10 wt% of a nonionic surfactant. The cutting oil composition is excellent in all properties, including residual metal impurity removal ability, cleaning ability, viscosity, surface tension, corrosivity, dispersibility, lubricity, wafer uniformity, and abrasion resistance, and is particularly excellent in cleaning ability and metal ion impurity removal ability.

Description

[Technical Field]

[0001] The present invention relates to a cutting oil composition for use in wire saw cutting processes, and more particularly to a wire saw cutting oil composition comprising a metal-removing chelating agent comprising a nitrogen-containing carboxylic acid or carboxylate compound, a highly hydrotreated hydrocarbon distillate base oil, a thickener, a dispersant, an oiliness improver, and a nonionic surfactant. [Background technology]

[0002] Wire saw cutting is the primary method for slicing ingots to produce thin wafers used in the integrated circuit and photovoltaic industries. Furthermore, this method is also commonly used in the manufacture of substrates of other materials, such as sapphire, silicon carbide or ceramic substrates into wafers. Wire saws typically have a web or wire web of fine metal wires, where the individual wires have a diameter of about 0.15 mm and are arranged parallel to one another at distances of 0.1 to 1.0 mm through a series of spools, pulleys, and wire guides. Cutting is accomplished by contacting a workpiece, such as a substrate, with a moving wire to which a cutting oil composition has been applied. In a typical wire saw cutting process, a cutting oil composition containing mineral or synthetic oil, thickeners, dispersants, etc. is used, mixed with abrasive particles made of hard materials such as silicon carbide particles in a weight ratio of about 1:1. The cutting oil composition is a liquid that provides lubrication and cooling and maintains the abrasive on the wire, thereby allowing the abrasive to contact the workpiece being cut. For cutting oil to perform optimally, it needs the right balance of lubricity and viscosity. If the lubricity is too high, the fine abrasive particles will not adhere to the workpiece and will slide, reducing cutting ability. If the lubricity is low, the individual fine abrasive particles will not be able to exert their full cutting ability. Recently, companies performing wire saw processes have been reusing oil that has been used once, but this has caused problems: the copper alloy plated on the wire during the wire saw process is peeled off by the reused cutting oil and abrasive particles, and copper ions penetrate the wafer surface, increasing metal contamination on the wafer surface. Cutting oil compositions include hydrophobic materials such as mineral oil, kerosene, polyethylene glycol, polypropylene glycol or other polyalkylene glycols, and hydrophilic materials may also be used in wire saw cutting processes. Conventional cutting oil compositions often have problems such as: the copper alloy plated on the wire peels off during the wire sawing process, leaving copper ions on or penetrating the wafer surface, increasing contamination; reducing the dispersibility of abrasive particles; reducing the floating persistence of abrasive particles; having too little or too much lubricity; requiring too long a wafer cleaning time after the wire sawing process; and causing significant wafer warpage after the wire sawing process.

[0003] Cutting oil is premixed with abrasive particles in a mixer attached to the oil tank of the cutting equipment, and must be redispersed from time to time using a small mixer to prevent the cutting oil and abrasive particles from reseparating. Separated abrasive particles clump together, clogging the cutting oil transfer pipe and causing circulation problems. The cutting oil's lack of suspension, lubricity, and dispersibility leads to problems such as wire wear, uneven wafer cutting, and a shortened lifespan of slurry particles, increasing manufacturing costs and reducing cleaning power in subsequent processes. Reusing cutting oil can cause the copper alloy plated on the wire to peel off during the wire saw process, and these metal impurities can penetrate into the silicon of the silicon wafer, increasing the impurity density on the surface of the silicon wafer. For this reason, various attempts have been made to improve the chelating agents added to cutting oils to prevent metals mixed in during the cutting process from remaining on or penetrating the wafer surface. However, in the case of EDTA (ethylenediaminetetraacetic acid) and DTPA (diethylenetriaminepentaacetic acid), they do not dissolve well in the mineral oil or synthetic oil used as the base oil, or their effectiveness is insufficient. That is, when conventional cutting oil compositions are comprehensively evaluated in terms of dispersibility, cleaning power, degree of wafer warpage after the wire saw process, and concentration of metal ion impurities on the wafer surface after the wire saw process, they tend to be poor in one or more of these properties, making them inappropriate cutting oil compositions. In order to solve these problems, the inventors invented and granted a prior patent (Korean Patent Registration No. 10-2062341) which was useful in the cutting process due to its excellent properties in viscosity, abrasive particle dispersibility, cleanability, wafer uniformity, and abrasion resistance. However, the cutting oil composition of the prior patent still had the problem of metal ion impurities, especially copper (Cu), nickel (Ni), manganese (Mn), chromium (Cr), and iron (Fe), remaining on or penetrating the wafer surface after the cutting process. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Korean Patent Registration No. 10-2062341 [Patent Document 2] Korean Patent Publication No. 10-2009-48518 [Patent Document 3] Korean Patent Publication No. 10-2009-65847 [Patent Document 4] Korean Patent Publication No. 10-2011-39725 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made to solve these problems, and its object is to provide a cutting oil composition that, when evaluated for all properties related to the ability to remove residual metal impurities, cleaning power, viscosity, surface tension, corrosivity, dispersibility, lubricity, wafer uniformity, abrasion resistance, etc., has no poor results in one or more properties, and is generally superior to conventional cutting oil compositions in all properties, particularly in cleaning power and ability to remove metal ion impurities. [Means for solving the problem]

[0006] In order to achieve the above object, the present invention provides a cutting oil composition containing the following Components A to F: a base oil, a chelating agent, a thickener, a dispersant, an oiliness improver, and a nonionic surfactant. Each component will be described below, along with a composition that is a mixture of these components. 1. Ingredient A Component A is one or more highly hydrotreated base oils represented by Chemical Formula 1, Chemical Formula 2, or Chemical Formula 3 below. [Chemical formula 1] R1-(CnH2n-4)a-R2 [Chemical formula 2] R3-(CnH2n-2)b-R4 [Chemical formula 3] R5-(CnH2n)c-R6 (In the above Chemical Formulas 1 to 3, n is 5 or 6, a is 3 to 7, b is 40 to 50, c is 45 to 55, and R1, R2, R3, R4, R5, and R6 are each H or OH.) In the prior patent, Korean Patent No. 10-2062341, the base oil of Component A is such that in Chemical Formulas 1 to 3, a is 7 to 20, b is 39 to 52, and c is 39 to 41. However, in the present invention, as a result of further in-depth research, it has been revealed that the base oil of Component A is preferably such that in Chemical Formulas 1 to 3, a is 3 to 7, b is 40 to 50, and c is 45 to 55. Furthermore, it has been revealed that it is particularly preferable that a is 5, b is 45, and c is 50. It was also revealed that it is preferable that the base oil of component A is a mixture of similar amounts of the chemical formulas 1 to 3, and it is most preferable that the chemical formulas 1 to 3 are mixed in equal amounts. Here, the base oil of Component A is preferably contained in an amount of 50 to 95% by weight based on the total weight of the composition.

[0007] 2. Component B Component B is a chelating agent for removing metals, and the chelating agent is a nitrogen-containing carboxylic acid or carboxylate compound, such as gamma-aminobutyric acid, nitrilotriacetic acid, diaminosuccinic acid, diethylimidocarbonate, β-aminobutyric acid, succinamic acid, alanine, iminodiacetic acid, ethyl 3-amino-3-ureidobutyrate, 2-aminobutanedioic acid, 2-aminopentanedioic acid, 2-amino-3-carbamoylpropanoic acid, 2-amino-4-carbamoyl The active ingredient is a substance selected from the group consisting of glutaric acid, 2-amino-5-carbamimidoylpentanoic acid, 2,4-diaminopentanedioic acid, 2,6-diaminohexanoic acid, 3-aminopentanoic acid and N-hydroxycarbamimidoylacetic acid, glutaric acid, nicotinic acid, maleic acid, malonic acid, malic acid, valeric acid, butyric acid, succinic acid, citric acid, acetic acid, acrylic acid, oxalic acid, lactic acid, formic acid, propionic acid, phthalic acid and salts thereof, or a mixture thereof. Here, the chelating agent of Component B is preferably contained in an amount of 0.1 to 5% by weight based on the total weight of the composition. 3. Component C Component C is a thickener selected from the group consisting of finely divided chalk powder, finely divided clay powder, and finely divided organic complex materials containing sorbitan monooleate and alpha olefins, and bentonite, or a mixture thereof, with bentonite being most preferred. Here, the thickener of component C is preferably contained in an amount of 0.1 to 10% by weight based on the total weight of the composition. 4. Component D Component D is a dispersant selected from the group consisting of Fe2O3, Na2O, Al2O3, and SiO2O, or a mixture thereof, and is more preferably Fe2O3, Na2O, or a mixture thereof. Here, the dispersant of component D is preferably contained in an amount of 0.1 to 6% by weight based on the total weight of the composition. 5. Component E Component E is an oiliness improver and is one or more selected from the group consisting of plant and animal fatty acid oils of the following chemical formula 4 and alkyl oleates of the following chemical formula 5, and is preferably contained in an amount of 1 to 20 wt % based on the total weight of the composition. [Chemical formula 4] R7-COO-R8 (wherein R7 is hydrogen or alkyl, and R8 is a C11 to C22 saturated fatty acid, unsaturated fatty acid, or vegetable or animal fatty acid ester, and the chemical formula is an ester compound derived from a trihydric to pentahydric alcohol and a monobasic fatty acid.) [Chemical formula 5] R9-C(CH3)2(OCOR10) (wherein R9 is methyl, ethyl, propyl, or butyl, and R10 is C11 to C22 alkyl, and the chemical formula is an ester compound derived from a trihydric to pentahydric alcohol and a monobasic fatty acid.)

[0008] 6. Component F Component F is a nonionic surfactant, and is at least one selected from the group consisting of the following chemical formula 6, and may be contained in an amount of 1 to 10 wt % based on the total weight of the composition. [Chemical formula 6] R11-(AO)n-R12 (In the formula, R11 and R12 each independently represent a hydrogen group (-H), a hydroxyl group (-OH), a linear or branched alkyl group having 1 to 20 carbon atoms, or a linear or branched alkenyl group having 1 to 20 carbon atoms; A represents an alkylene group having 2 to 4 carbon atoms; and n represents a natural number from 1 to 25.) The cutting oil composition is characterized by its use in dispersing abrasives. Silicon carbide can be used as the abrasive, and can be obtained by subjecting silica powder and coke powder to a thermal carbonization reduction process in an electric furnace. Its color ranges from green to dark gray depending on the temperature. Generally, SiC has a very high hardness (Knoop hardness of 2700 or higher and Mohs hardness of 9.5 or higher) and is therefore excellent in grinding power. It is therefore primarily used as an abrasive for silicon substrates for semiconductors and solar cells. These abrasive (Green-SiC) particles can be dispersed in oil by a conventional agitator, or by a homogenizer, ultrasonic disperser, ball mill, etc. To disperse particles with dimensions of less than a micrometer, it is preferable to use a dispersing device such as a ball mill, vibration ball mill, planetary ball mill, or media-agitating mill. [Effects of the Invention]

[0009] The present invention provides a cutting oil composition that is superior in all properties overall, particularly in detergency and metal ion impurity removal, while being no worse than conventional cutting oil compositions in at least one of the properties related to residual metal impurity removal, detergency, viscosity, surface tension, corrosivity, dispersibility, lubricity, wafer uniformity, and abrasion resistance. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE INVENTION The following detailed description of the present invention is provided by way of example only and is not intended to limit the invention, which is defined solely by the scope of the claims that follow. The components that can be used in the cutting oil composition of the present invention will be described in detail below. 1. Ingredient A Component A is the base oil contained in the composition. Examples of the base oil of Component A include low-viscosity paraffinic or naphthenic base oils, which are pure lubricating oils. The paraffinic and naphthenic base oils of Component A are basic substances that disperse and dissolve the additives described below. To prevent additive separation due to temperature changes, it is preferable to use a base oil with a low pour point, and for environmental and workplace safety, it is preferable to use a high-purity, high-grade refined base oil. This Component A is contained in an amount of 50 to 95% by weight of the entire composition as the base oil. A base oil containing both naphthenic and paraffinic base oils is preferred. [Chemical formula 1] R1-(CnH2n-4)a-R2 [Chemical formula 2] R3-(CnH2n-2)b-R4 [Chemical formula 3] R5-(CnH2n)c-R6 (In the above Chemical Formulas 1 to 3, n is 5 or 6, a is 3 to 7, b is 40 to 50, c is 45 to 55, and R1, R2, R3, R4, R5, and R6 are each H or OH.) 2. Component B Component B of the composition is a chelating agent for removing metals, which is composed of a nitrogen-containing carboxylic acid or carboxylate compound. Specific examples of component B include nitrogen-containing carboxylic acids such as gamma-aminobutyric acid, nitrilotriacetic acid, diaminosuccinic acid, diethylimidocarbonate, β-aminobutyric acid, succinamic acid, alanine, iminodiacetic acid, ethyl 3-amino-3-ureidobutyrate, 2-aminobutanedioic acid, 2-aminopentanedioic acid, 2-amino-3-carbamoylpropanoic acid, 2-amino-4-carbamoylbutanoic acid, 2-amino-5-carbamimidoylpentanoic acid, 2,4-diaminobutanedio ... The cutting oil composition may contain carboxylic acids such as glutaric acid, nicotinic acid, maleic acid, malonic acid, malic acid, valeric acid, butyric acid, succinic acid, citric acid, acetic acid, acrylic acid, oxalic acid, lactic acid, formic acid, propionic acid, phthalic acid, and salts thereof, and may be used in an amount of 0.1 to 5 wt %, preferably 0.3 to 3 wt %, based on the weight of the cutting oil composition. The chelating agent for metal removal has a coordination number of 2 to 6, and therefore can effectively form complexes with metals having outermost electrons in the 4s and 3d orbitals. On the other hand, the metals having outermost electrons in the 4s and 3d orbitals exist as relatively small atoms and ions, and therefore do not easily form complexes with chelate compounds having a high coordination number of 7 or more. Chelating agents with a high coordination number of 7 or more readily form complexes with metals that have their outermost electrons in the 5f orbital, but their ability to form complexes with relatively small metals in the fourth period or less of the periodic table, such as copper (Cu), nickel (Ni), manganese (Mn), chromium (Cr), and iron (Fe), is reduced. The chelating agent having a coordination number of 2 to 6 added to the cutting oil composition of the present invention has excellent ability to form complex compounds with metals such as magnesium (Mg), aluminum (Al), potassium (K), calcium (Ca), titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), and lead (Pb), specifically with period 4 metals such as copper (Cu), nickel (Ni), manganese (Mn), chromium (Cr), and iron (Fe), and therefore has excellent ability to prevent metal ions generated during the cutting process from remaining on or penetrating into the wafer.

[0011] 3. Component C Component C of the composition is a composite dispersion powder containing alpha olefin, finely divided chalk powder, finely divided clay powder, and sorbitan monooleate, or a composite dispersion powder selected from the group consisting of organoclay and organobentonite. Component C is a fine organic composite material used as an additive. Component C maintains the appropriate adhesiveness of the inorganic particles contained in the slurry, thereby ensuring uniform dispersion on the cutting tool (wire). Bentonite, a component contained in the composite dispersion powder used in Component C, is expressed, for example, as NaSi(AlMg)O(OH). Component C is contained in an amount of 0.1 to 10 wt %, preferably 1 to 5 wt %, based on the total weight of the composition. If the amount of Component C is less than 0.1 wt %, the slurry will not maintain the appropriate adhesiveness, whereas if the amount of Component C is more than 10 wt %, the slurry will be too adhesive and unsuitable. 4. Component D Component D of the composition is a dispersant containing one or more substances selected from the group consisting of Fe2O3, Na2O, Al2O3, and SiO2. The powder used as component D acts as a dispersant to facilitate dispersion of the slurry powder in cutting oil. Component D is contained in an amount of 0.1 to 5 wt. % of the total composition, preferably 0.5 to 3 wt. If component D is contained in an amount less than 0.1 wt. %, the slurry powder is not easily dissolved and dispersed in cutting oil. On the other hand, if component D is contained in an amount greater than 6 wt. %, the slurry powder is excessively dissolved and dispersed, preventing smooth cutting operations. 5. Component E Component E of the composition is one or more oiliness improvers selected from the group consisting of plant and animal fatty acid oils or alkyl oleates, wherein the oiliness improver is a substance represented by the following chemical formula 4 or 5, or a mixture thereof: [Chemical formula 4] R7-COO-R8 (In the above chemical formula, R7 is hydrogen or alkyl, and R8 is a C11 to C22 saturated fatty acid, unsaturated fatty acid, or vegetable or animal fatty acid ester, and the above chemical formula is an ester compound derived from a trihydric to pentahydric alcohol and a monobasic fatty acid.) [Chemical formula 5] R9-C(CH3)2(OCOR10) (In the above chemical formula, R9 is methyl, ethyl, propyl, or butyl, R10 is C11 to C22 alkyl, and the above chemical formula is an ester compound derived from a trihydric to pentahydric alcohol and a monobasic fatty acid.) The oiliness improver of component E is a synthetic or natural fatty oil. These are higher synthetic esters or higher fatty oils that provide adequate lubricity for wire sawing and reduce viscosity increases and oil separation due to solidification at low temperatures. The oiliness improver is contained in an amount of 1 to 20% by weight, preferably 5 to 10% by weight, based on the total composition. If the oiliness improver is contained in an amount less than 1% by weight, oil separation occurs, resulting in storage stability problems. If the oiliness improver is contained in an amount greater than 20% by weight, viscosity decreases and lubricity increases, preventing individual fine abrasive particles from exerting their sufficient cutting ability.

[0012] 6. Component F Component F of the composition is a nonionic surfactant, an auxiliary substance that functions as a cleaning and lubricating additive in the present invention. It is represented by the following chemical formula 6, and specific examples include polyethylene glycol fatty acid diester (HLB: 10.4), sorbitan fatty acid ester (HLB: 9.6), polyethylene glycol fatty acid diester (HLB: 8.4), ethoxylated propoxylated alcohols (HLB: 7.3), and polyoxyethylene lauryl ether (HLB: 6.2). The nonionic surfactant, component F, is contained in an amount of 1 to 10% by weight of the total composition. [Chemical formula 6] R11-(AO)n-R12 (In the above chemical formula, R11 and R12 each independently represent a hydrogen group (-H), a hydroxyl group (-OH), a linear or branched alkyl group having 1 to 20 carbon atoms, or a linear or branched alkenyl group having 1 to 20 carbon atoms; A represents an alkylene group having 2 to 4 carbon atoms; and n represents a natural number from 1 to 25.) The specific configurations and effects of the present invention will be described in more detail through the following examples and experimental examples.

[0013] [Examples 1 to 28 and Comparative Examples 1 to 15] The cutting oil compositions of the Examples and Comparative Examples were added to each experimental beaker equipped with a home mixer in the composition ratios shown in Table 1. The beakers were then sealed and stirred at room temperature for 90 minutes at a speed of 3,000 rpm to prepare the compositions. The HLB (Hydrophile-Lipophile Balance) value of a nonionic surfactant is measured using the Griffin method. The HLB value indicates the surfactant's affinity for water or oil, and ranges from 0 to 20. The closer the HLB value is to 0, the stronger the hydrophobic (lipophilic) properties of the nonionic surfactant, and the closer the HLB value is to 20, the stronger the hydrophilic properties of the nonionic surfactant. [Table 1a] [Table 1b] [Table 1c]

[0014] [Experimental Examples 1 to 28 and Comparative Experimental Examples 1 to 15] The compositions were prepared in Examples 1 to 28 and Comparative Examples 1 to 15, and the results were obtained for each test item by the following methods (1) to (7). (1) Viscosity The viscosity was measured using a DV-II+Pro model manufactured by Brookfield Corporation, and was measured using spindles No. 61 and 62 at a spindle speed of 60 rpm. In this case, a cutting oil composition having a viscosity of 60 to 120 mPa·s at 25°C is suitable. (2)Surface tension The surface tension of the cutting oil composition was measured using a surface tension measuring instrument (model name: Tensiometer K100, manufacturer: KRUSS). (3) Abrasive particle dispersibility Dispersibility was evaluated by filling a slurry made by mixing cutting oil with silicon carbide (SiC) powder in a 1:1 weight ratio into a graduated measuring cylinder, leaving it at room temperature for 7 days, and then measuring the amount of supernatant liquid. In this case, a cutting oil composition having no supernatant liquid or a small amount of supernatant liquid is suitable. (4) Cleaning power A mixture of cutting oil and cutting residue (abrasives, wafer chips) generated after cutting the wafer was applied to the wafer, and the wafer was dried at 85°C for 8 hours to prepare a contamination test piece. Two of these contamination test pieces were bonded together with a gap of 0.2 mm between them, then immersed in a cleaning solution (model name: YKC-B620, manufacturer: Young Chang Chemical) and washed at 40 degrees for 10 minutes, and then rinsed with water three times. The degree of contamination remaining on the wafer surface was evaluated as follows: <Evaluation criteria> ◎: The contamination source remains within 5% of the total area ○: The contamination source remains within 5-15% of the total area. △: Contamination source remains within 15-25% of the total area X: Contamination source remains at 25% or more of the total area (5) Wafer flatness The measurement of wafer flatness after sawing is done by measuring the degree of warpage of individual wafers after cleaning is completed. 、 In this case, a cutting oil composition that was evaluated as having a degree of warpage of the wafer after sawing of 10 μm or less was considered to be excellent. (6) Metal ion removal ability To confirm the extent to which metal impurities generated during the cutting process are removed or controlled by the cutting oil, a Cu / Ni standard solution was used to spin coat the Cu / Ni impurities at 1.0E12 atoms / cm 2 After contaminating the surface of a silicon wafer with a concentration of 1000 ppm, the following experiment was carried out to calculate the amount of metal impurities that had penetrated into the surface of the wafer before and after immersion in the cutting oil. In this case, a cutting oil composition containing a small amount of residual metal impurities is suitable. 1) Silicon wafers contaminated with Cu and Ni standard solutions were immersed at room temperature for 5 minutes each in cutting oil compositions containing the metal-removing chelating agents prepared in the examples and comparative examples. 2) The immersed wafer is washed with refined kerosene and isopropyl alcohol, dried with nitrogen gas, and then stored in a nitrogen box. 3) Next, a solution of 1 wt % hydrofluoric acid and 1 wt % hydrogen peroxide is diffused onto the surface of the wafer for 5 minutes, and then the surface of the wafer is etched for 5 minutes. 4) Next, the entire solution on the wafer was collected using a polyethylene dropper and analyzed using an inductively coupled plasma mass spectrometry (ICP-MS; manufacturer: Agilent, model name: 7700). (7) Wear resistance The anti-wear performance of the cutting oil compositions was tested in accordance with the ASTM D2266 Shell four-ball wear test under the following conditions: 30 minutes, 1,200±50 rpm, a cutting oil temperature of 75±5°C, and a load of 40±0.2 kg. After the test, the balls were removed, and the wear scars and the resulting diameters of the wear scars were measured and compared. In this case, a cutting oil composition that leaves no or only small wear marks is suitable.

[0015] [Table 2]

[0016] As shown in Table 2 above, the wafer cutting oil compositions of Examples 1 to 28 according to the present invention have superior cleaning power after the cutting process, and have a low concentration of residual metal ion impurities, thereby demonstrating superior metal ion impurity removal power, compared to Comparative Examples 1 to 15. They also have superior viscosity, surface tension, dispersibility, wafer uniformity, and abrasion resistance.

Claims

1. A cutting oil composition comprising a base oil represented by Chemical Formula 1, Chemical Formula 2 or Chemical Formula 3, a chelating agent, a thickener, a dispersant, an oiliness improver and a nonionic surfactant. [Chemical formula 1] R1-(CnH2n-4)a-R2 [Chemical formula 2] R3-(CnH2n-2)b-R4 [Chemical formula 3] R5-(CnH2n)c-R6 (In the above Chemical Formulas 1 to 3, n is 5 or 6, a is 3 to 7, b is 40 to 50, c is 45 to 55, and R1, R2, R3, R4, R5, and R6 are each H or OH.)

2. 2. The cutting oil composition according to claim 1, characterized in that it is composed of 50 to 95% by weight of the base oil, 0.1 to 5% by weight of a chelating agent, 0.1 to 10% by weight of a thickening agent, 0.1 to 5% by weight of a dispersant, 1 to 20% by weight of an oiliness improver, and 1 to 10% by weight of a nonionic surfactant.

3. The cutting oil composition according to claim 2, wherein a is 5, b is 45, and c is 50 in the chemical formulas 1 to 3.

4. The chelating agent may be selected from the group consisting of gamma-aminobutyric acid, nitrilotriacetic acid, diaminosuccinic acid, diethylimidocarbonate, beta-aminobutyric acid, succinamic acid, alanine, iminodiacetic acid, ethyl 3-amino-3-ureidobutyrate, 2-aminobutanedioic acid, 2-aminopentanedioic acid, 2-amino-3-carbamoylpropanoic acid, 2-amino-4-carbamoylbutanoic acid, 2-amino-5-carbamimidoylpentanoic acid, 2,4-diamino 4. The cutting oil composition according to claim 3, characterized in that the cutting oil is a substance selected from the group consisting of 2,6-diaminohexanoic acid, 3-aminopentanoic acid, N-hydroxycarbamimidoylacetic acid, glutaric acid, nicotinic acid, maleic acid, malonic acid, malic acid, valeric acid, butyric acid, succinic acid, citric acid, acetic acid, acrylic acid, oxalic acid, lactic acid, formic acid, propionic acid, phthalic acid, and salts thereof, or a mixture thereof.

5. 4. The cutting oil composition of claim 3, wherein the thickener is a material selected from the group consisting of finely divided chalk powder, finely divided clay powder, finely divided organic complex material containing sorbitan monooleate and alpha olefin, and finely divided bentonite, or a mixture thereof.

6. The dispersant is Fe ２ O ３ , Na ２ O, Al ２ O ３ and Si ２ 4. The cutting oil composition according to claim 3, wherein the cutting oil composition is a material selected from the group consisting of:

7. The dispersant is Fe ２ O ３ , Na ２ 7. The cutting oil composition according to claim 6, wherein the cutting oil composition is selected from the group consisting of methylcellulose, ...

8. 4. The cutting oil composition according to claim 3, wherein the oiliness improver is a substance represented by the following chemical formula 4 or 5, or a mixture thereof: [Chemical formula 4] R7-COO-R8 (In the above chemical formula, R7 is hydrogen or alkyl, and R8 is a C11 to C22 saturated fatty acid, unsaturated fatty acid, or vegetable or animal fatty acid ester, and the above chemical formula is an ester compound derived from a trihydric to pentahydric alcohol and a monobasic fatty acid.) [Chemical formula 5] R9-C(CH3)2(OCOR10) (In the above chemical formula, R9 is methyl, ethyl, propyl, or butyl, R10 is C11 to C22 alkyl, and the above chemical formula is an ester compound derived from a trihydric to pentahydric alcohol and a monobasic fatty acid.)

9. 4. The cutting oil composition according to claim 3, wherein the nonionic surfactant is a substance represented by the following chemical formula 6: [Chemical formula 6] R11-(AO)n-R12 (In the above chemical formula, R11 and R12 each independently represent a hydrogen group (—H), a hydroxyl group (—OH), a linear or branched alkyl group having 1 to 20 carbon atoms, or a linear or branched alkenyl group having 1 to 20 carbon atoms; A represents an alkylene group having 2 to 4 carbon atoms; and n represents a natural number from 1 to 25.)

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