Working fluid

Abstract

To provide a working fluid which can be used in a multi-wire saw device, has proper cutting performance, and is excellent in cleanliness.SOLUTION: A working fluid comprising an active ingredient and water, wherein the active ingredient comprises the following components (A) and (B), and the content of the component (B) is 25.0% by mass or less based on the total amount of the active ingredient: ･Component (A): One or more selected from alkylene glycol and epichlorohydrin-unmodified polyoxyalkylene compound Component (B): Epichlorohydrin-modified polyoxyalkylene compound SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to machining fluids. [Background technology]

[0002] In the manufacture of semiconductor products, it is important to accurately cut silicon ingots, which are brittle materials, and wire sawing is generally used for cutting silicon ingots from the viewpoints of processing precision and productivity. Wire sawing is also used for processing materials such as ceramics, quartz, sapphire, and glass. Generally, machining methods using a wire saw include the free abrasive method, in which machining is performed while supplying free abrasive grains to the sliding area between the wire and the workpiece, and the fixed abrasive method, in which machining is performed using a wire with abrasive grains fixed to its surface in advance. In both of the above wire sawing methods, a working fluid (coolant) is used to improve the efficiency of cutting, suppress friction between the workpiece and the tool that processes it, reduce frictional heat generated by processing, extend the life of the tool, remove chips, etc. The working fluids used for the above purposes include oil-based working fluids whose main components are mineral oil, animal and vegetable oil, synthetic oil, etc., and water-based working fluids that are made water-soluble by blending surfactant compounds. In recent years, water-soluble machining fluids have come to be used from the viewpoints of safety during work and environmental issues.

[0003] For example, Patent Document 1 discloses a water-soluble cutting fluid for slicing silicon ingots, characterized by containing, as essential components, a polyoxyalkylene adduct having a number average molecular weight of 500 or less and a specific structure, and a monovalent or divalent aliphatic carboxylic acid or a salt thereof having 4 to 10 carbon atoms (including the carbon of the carbonyl group). Patent Document 2 discloses a water-soluble working fluid composition for a fixed abrasive wire saw used to cut rare earth magnets, characterized in that the composition contains specific amounts of glycols, carboxylic acids, compounds that dissolve in water and exhibit basicity, and water (however, the total of these components is 100 parts by weight). Patent Document 3 discloses a fluid for processing brittle materials, which contains at least one selected from the group consisting of alkynediols having an HLB value of 4 or more and 12 or less and alkylene oxide adducts of alkynediols having an HLB value of 4 or more and 12 or less, a nonionic surfactant which is an ethylene oxide adduct having an HLB value of 6 or more and the number of added moles of ethylene oxide in the molecular structure of 5 or more and which does not have a carbon-carbon triple bond, and a carboxylic acid, each in a specific content.

[0004] In both of the above wire sawing methods, a multi-wire saw machine is used to cut multiple wafers from an ingot at once. In the multi-wire saw machine, two or more guide rollers are formed with a plurality of grooves at regular intervals, and one wire is wound around each groove on the rollers, and the wires are held parallel to each other with a constant tension. During cutting, the guide rollers are rotated, and a machining fluid discharged from a nozzle or the like is applied to the wire while the wire travels in one or both directions. The ingot is pressed against the wire to which the machining fluid is applied to cut the ingot. The multi-wire saw device allows for efficient cutting by cutting out a large number of wafers at once. It also has the advantage of being able to easily accommodate larger diameter ingots, as the cutting allowance is narrow and material loss during cutting is relatively small. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-68884 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-82335 [Patent Document 3] Japanese Patent Application Publication No. 2018-154762 Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, in recent years, with the increasing demand for semiconductors, solar cells, etc., effective utilization of materials has become an issue from the perspective of reducing the manufacturing costs of semiconductors, solar cells, etc. In light of this situation, when cutting wafers using a multi-wire saw device, studies are being conducted to further narrow the cutting allowance to reduce material loss during cutting, increase the number of wafers obtained in one cutting pass, and improve the efficiency of material utilization (yield). One way to further narrow the cutting allowance and reduce material loss during cutting is to use thinner wires, while another way to increase the number of wafers obtained in one cutting operation is to narrow the spacing between the wires in a multi-wire saw. However, in a multi-wire saw device, the wire saw and the cut wafers etc. are significantly contaminated by fine chips generated during the cutting process, and the load of cleaning them is increased. It is also necessary to ensure sufficient cutting performance of the wire saw.

[0007] Therefore, an object of the present invention is to provide a machining fluid that can be used in a multi-wire saw device, has appropriate cutting performance, and is excellent in cleanliness. [Means for solving the problem]

[0008] According to the present invention, the following [1] to

[10] are provided. [1] A processing fluid containing an active ingredient and water, The active ingredients of the processing fluid include the following components (A) and (B), and the content of component (B) is 25.0 mass% or less based on the total amount of the active ingredients. Component (A): One or more selected from alkylene glycols and epichlorohydrin-unmodified polyoxyalkylene compounds Component (B): Epichlorohydrin-modified polyoxyalkylene compound [2] The processing fluid according to the above [1], wherein the component (A) is a polyoxyalkylene compound. [3] The processing fluid according to the above [1] or [2], wherein the content of the component (A) is 50 to 99.9 mass% based on the total amount of the active ingredients. [4] The working fluid according to any one of the above [1] to [3], wherein the content of the component (B) is 0.05 to 23.0 mass % based on the total amount of the active ingredients. [5] The working fluid according to any one of the above [1] to [4], wherein the total content of the components (A) and (B) is 50 to 100 mass % based on the total amount of the active ingredients. [6] The machining fluid according to any one of the above [1] to [5], which is used when cutting a workpiece made of a brittle material using a multi-wire saw device. [7] The machining fluid according to [6] above, wherein the wires constituting the multi-wire saw device are fixed abrasive wires. [8] The working fluid according to [6] or [7] above, wherein the brittle material is crystalline silicon, sapphire, silicon carbide, gallium nitride, neodymium magnet, quartz crystal, or glass. [9] The machining fluid according to any one of [6] to [8], wherein the wires constituting the multi-wire saw device have a wire diameter of 120 μm or less and a wire spacing of 1,100 μm or less.

[10] A method for producing a processing fluid containing an active ingredient and water, mixing the active ingredient with the water; A method for producing a machining fluid, wherein the active ingredients contain the following components (A) and (B), and the content of component (B) is 25.0 mass% or less based on the total amount of the active ingredients: Component (A): One or more selected from alkylene glycols and epichlorohydrin-unmodified polyoxyalkylene compounds Component (B): Epichlorohydrin-modified polyoxyalkylene compound [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a machining fluid that can be used in a multi-wire saw device, has appropriate cutting performance, and is excellent in cleanliness. DETAILED DESCRIPTION OF THE INVENTION

[0010] The upper and lower limits of the ranges described herein can be combined in any way. For example, if the ranges are "A to B" and "C to D," the ranges "A to D" and "C to B" are also included in the scope of the present invention. Furthermore, unless otherwise specified, the numerical range "lower limit to upper limit" described in this specification means that the range is equal to or greater than the lower limit and equal to or less than the upper limit. In this specification, the numerical values ​​in the examples are numerical values ​​that can be used as upper or lower limit values. Unless otherwise specified, the term "polyoxyalkylene compound" used herein refers to a compound having oxyalkylene units as repeating units, the molecular terminals of which may be hydroxyl groups or hydrocarbyloxy groups. The oxyalkylene units may be of one type or a combination of two or more types. The oxyalkylene unit preferably has 2 to 4 carbon atoms. The origin of the oxyalkylene unit is not particularly limited, and it may be derived from an alkylene oxide or a diol. Specific examples of alkylene oxides include ethylene oxide, propylene oxide (PO), oxetane, 1,2-butylene oxide, 2,3-butylene oxide, 1,3-butylene oxide, and tetrahydrofuran.

[0011] [Form of machining fluid] The machining fluid of this embodiment contains an active ingredient and water. The active ingredient contains the following ingredient (A) and ingredient (B), and the content of ingredient (B) is 25.0 mass % or less based on the total amount of the active ingredients. Component (A): One or more selected from alkylene glycols and epichlorohydrin-unmodified polyoxyalkylene compounds Component (B): Epichlorohydrin-modified polyoxyalkylene compound

[0012] The present inventors have conducted extensive research to solve the above problems. As a result, the inventors discovered that a machining fluid containing the above components could solve the above problems, and after further investigations, they completed the present invention.

[0013] The active ingredients contained in the machining fluid of this embodiment will be described in detail below.

[0014] <Component (A)> Component (A) is at least one member selected from alkylene glycols and epichlorohydrin-unmodified polyoxyalkylene compounds. The alkylene glycol preferably has 2 to 4 carbon atoms, and propylene glycol is particularly preferred. The epichlorohydrin-unmodified polyoxyalkylene compound is a compound having oxyalkylene units as repeating units, the molecular terminals of which may be hydroxyl groups or hydrocarbyloxy groups. The oxyalkylene units contained in the polyoxyalkylene compound may be one type or two or more types. When two or more types are combined, the addition of the multiple types of oxyalkylene units may be either random addition or block addition, or a mixture of random addition and block addition, but is preferably a block addition copolymer. Specific examples of the epichlorohydrin-unmodified polyoxyalkylene compound include polyoxyethylene homopolymers, polyoxyethylene-polyoxypropylene random copolymers, polyoxyethylene-polyoxypropylene block copolymers, and polyoxyalkylene hydrocarbyl ethers having hydrocarbyloxy groups at one or both of the molecular terminals thereof, and polyoxyethylene-polyoxypropylene block copolymers or their monohydrocarbyl ethers or dihydrocarbyl ethers are preferably used. The epichlorohydrin-unmodified polyoxyalkylene compound may be an oligomer of diethylene glycol, dipropylene glycol, or the like.

[0015] Examples of the hydrocarbyloxy group include those having 1 to 24 carbon atoms. From the viewpoint of the balance between hydrophilicity and lipophilicity, those having 1 to 14 carbon atoms are preferred, those having 1 to 10 carbon atoms are more preferred, and those having 1 to 6 carbon atoms are even more preferred. The hydrocarbyloxy group may be linear, branched, or cyclic, and is preferably linear, but is preferably a linear or branched alkoxy group. The preferred range of the carbon number of the alkoxy group is the same as that of the hydrocarbyloxy group described above.

[0016] Polyoxyalkylene hydrocarbyl ethers can be synthesized, for example, by adding alkylene oxide (hereinafter also referred to as "AO") to alcohol. The addition of AO to alcohol can be carried out by a known method, and may be carried out in the absence or presence of a catalyst, under normal pressure or elevated pressure, in one step or in multiple steps.

[0017] Examples of the alcohol include aliphatic alcohols having from 1 to 24 carbon atoms. From the viewpoint of the balance between hydrophilicity and lipophilicity, the number of carbon atoms of the alcohol is preferably 1 to 14, more preferably 1 to 10, even more preferably 1 to 6, still more preferably 1 to 4, still more preferably 1 or 2, and still more preferably 1. The aliphatic alcohol is preferably a primary alcohol or a secondary alcohol, more preferably a primary alcohol, and may be linear, branched, or cyclic, with linear being preferred. Examples of the aliphatic alcohol include methanol, ethanol, propanol, isopropanol, butanol, isobutanol, 2-methyl-2-butanol, pentanol, isopentanol, hexanol, 3-methyl-1-pentanol, heptanol, 2-heptanol, 3-heptanol, octanol, 2-ethylhexanol, nonanol, decanol, undecyl alcohol, lauryl alcohol, tridecyl alcohol, isotridecyl alcohol, myristyl alcohol, pentadecyl alcohol, palmityl alcohol, heptadecanol, and stearyl saturated aliphatic alcohols such as ethyl cyclohexyl alcohol, isostearyl alcohol, nonadecyl alcohol, and eicosanol; unsaturated aliphatic alcohols such as octenyl alcohol, decenyl alcohol, dodecenyl alcohol, tridecenyl alcohol, tetradecenyl alcohol, palmitoleyl alcohol, oleyl alcohol, gadoleyl alcohol, and linoleyl alcohol; and cyclic aliphatic alcohols such as ethyl cyclohexyl alcohol, propyl cyclohexyl alcohol, octyl cyclohexyl alcohol, nonyl cyclohexyl alcohol, and adamantyl alcohol.

[0018] Examples of the AO include alkylene oxides having 2 to 4 carbon atoms, such as ethylene oxide (hereinafter also referred to as "EO"), propylene oxide (hereinafter also referred to as "PO"), oxetane, 1,2-butylene oxide, 2,3-butylene oxide, 1,3-butylene oxide, and tetrahydrofuran. Of these, a combination of EO and PO is preferred. When a combination of EO and PO is used as AO, the addition of EO and PO at the copolymerization site of the EO and PO may be either random addition or block addition, or a mixture of random addition and block addition may be used.

[0019] Furthermore, the ratio of oxyethylene units is preferably 15 mol% or more, more preferably 20 mol% or more, even more preferably 25 mol% or more, and is preferably 85 mol% or less, more preferably 80 mol% or less, even more preferably 75 mol% or less, based on the total amount of oxyalkylene units contained in the epichlorohydrin-unmodified polyoxyalkylene compound being 100 mol%.

[0020] From the viewpoint of improving lubricity, the mass average molecular weight (Mw) of the epichlorohydrin-unmodified polyoxyalkylene compound is preferably 500 or more, more preferably 1,000 or more, even more preferably 1,500 or more, and even more preferably 2,000 or more. On the other hand, from the viewpoint of improving the bite of the abrasive grains to the workpiece, the mass average molecular weight (Mw) of component (A-1) is preferably 10,000 or less, more preferably 9,000 or less, even more preferably 8,000 or less, and even more preferably 6,000 or less. In this specification, the value of the weight average molecular weight (Mw) is a value measured using the method described in the examples below.

[0021] The component (A) may be used alone or in combination of two or more.

[0022] The cloud point of a 1% by mass aqueous solution of the epichlorohydrin-unmodified polyoxyalkylene compound is preferably 15°C or higher, more preferably 18°C ​​or higher, and even more preferably 20°C or higher, from the viewpoint of making it easier to improve solubility in water. In this specification, the cloud point value of a 1% by mass aqueous solution of the epichlorohydrin-unmodified polyoxyalkylene compound is a value measured using the method described in the examples below. The cloud point of the epichlorohydrin-unmodified polyoxyalkylene compound can be adjusted, for example, by lowering the EO ratio of the epichlorohydrin-unmodified polyoxyalkylene compound.

[0023] The content of component (A) is preferably 50 to 99.9 mass % based on the total amount of the active ingredients, more preferably 60.0 to 99.8 mass %, and even more preferably 65.0 to 99.5 mass %.

[0024] <Ingredient (B)> Component (B) is an epichlorohydrin-modified polyoxyalkylene compound. As component (B), a compound obtained by contacting the epichlorohydrin-unmodified polyoxyalkylene compound described above as component (A) with epichlorohydrin to modify or polymerize it can be used, but it may also be a compound having an oxyalkylene unit derived from the polymerization site of epichlorohydrin, which is obtained by adding epichlorohydrin to an alcohol and polymerizing it, or a compound having an oxyalkylene unit as the copolymerization site of alkylene oxide and epichlorohydrin, which is obtained by polymerizing alkylene oxide and epichlorohydrin to an alcohol.

[0025] As mentioned above, component (B) is a modified product with epichlorohydrin, and therefore may contain chlorine atoms.

[0026] From the viewpoint of the wafer cutting performance of the processing oil, the content of component (B) must be 25.0 mass% or less, based on the total amount of the active ingredients, preferably 0.05 to 23.0 mass%, more preferably 0.20 to 20.0 mass%, and particularly preferably 0.50 to 15.0 mass%.

[0027] The above active ingredient may contain the following ingredient (C): Component (C): Alkynediol alkylene oxide adduct

[0028] <Ingredient (C)> The component (C) is an alkylene oxide adduct of an alkynediol, and the method for producing it is not particularly limited. The alkynediol includes, for example, a compound represented by the following general formula (1).

[0029] [ka]

[0030] In general formula (1), R 1 ~R 4 each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. R 1 ~R 4 is preferably an alkyl group having 1 to 5 carbon atoms. R 1 ~R 4 Specific examples of the alkyl group having 1 to 6 carbon atoms that can be selected as aryl include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1,1-dimethylpropyl group, a 1,2-dimethylpropyl group, and a 2,2-dimethylpropyl group. Among these, R 1 and R 3 is preferably an isobutyl group or a 3-methylbutyl group. 2 and R 4 is preferably a methyl group. In addition, the compound represented by general formula (1) is preferably R 1 and R 3 are identical to each other or R 2 and R 4 are compounds having the same structure as each other, and more preferably R 1 and R 3 are identical to each other, and R 2 and R 4 are compounds having the same structure as each other.

[0031] Furthermore, component (C) is preferably an alkylene oxide adduct of a compound represented by general formula (1), in which AO is added to each hydroxyl group of the compound represented by general formula (1), more preferably an alkylene oxide adduct of a compound represented by general formula (1), in which EO and / or PO is added to each hydroxyl group of the compound represented by general formula (1), and even more preferably an ethylene oxide adduct of a compound represented by general formula (1), in which EO is added to each hydroxyl group of the compound represented by general formula (1). In addition, when a structure in which a structure derived from EO (for example, an ethyleneoxy group or a poly(oxyethylene) structure) and a structure derived from PO (for example, a propyleneoxy group or a poly(oxypropylene) structure) are bonded is contained, the respective structures may be bonded to each other in a random manner or in a block manner, and are preferably bonded in a block manner.

[0032] Specific examples of the alkynediol include 2,5,8,11-tetramethyl-6-dodecyne-5,8-diol, 5,8-dimethyl-6-dodecyne-5,8-diol, 2,4,7,9-tetramethyl-5-dodecyne-4,7-diol, 8-hexadecyne-7,10-diol, 7-tetradecyne-6,9-diol, 2,3,6,7-tetramethyl-4-octyne-3,6-diol, 3,6-diethyl-4-octyne-3,6-diol, 2,5-dimethyl-3-hexyne-2,5-diol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol, and 3,6-dimethyl-4-octyne-3,6-diol.

[0033] Component (C) is preferably 2,5,8,11-tetramethyl-6-dodecyne-5,8-diol, 5,8-dimethyl-6-dodecyne-5,8-diol, 2,4,7,9-tetramethyl-5-dodecyne-4,7-diol, 8-hexadecyne-7,10-diol, 7-tetradecyne-6,9-diol, 2,3,6,7-tetramethyl-4-octyne-3,6-diol, 3,6-diethyl-4-octyne-3,6-diol, 2, alkylene oxide adducts of one or more alkynediols selected from the group consisting of 5-dimethyl-3-hexyne-2,5-diol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol, and 3,6-dimethyl-4-octyne-3,6-diol; more preferably 2,5,8,11-tetramethyl-6-dodecyne-5,8-diol, 5,8-dimethyl-6-dodecyne-5,8-diol, 2,4,7,9-tetramethyl-5 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 5-octyne-4,7-diol, 6-hexadecyne-7,10-diol, 7-tetradecyne-6,9-diol, 2,3,6,7-tetramethyl-4-octyne-3,6-diol, 3,6-diethyl-4-octyne-3,6-diol, 2,5-dimethyl-3-hexyne-2,5-diol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol, and 3,6-dimethyl-4-octyne-3,6-diol. more preferably, one or more selected from the group consisting of an ethylene oxide adduct of 2,5,8,11-tetramethyl-6-dodecyne-5,8-diol and an ethylene oxide adduct of 2,4,7,9-tetramethyl-5-decyne-4,7-diol; and even more preferably, an ethylene oxide adduct of 2,5,8,11-tetramethyl-6-dodecyne-5,8-diol.

[0034] The component (C) may be used alone or in combination of two or more. Furthermore, the component (C) is preferably one or more selected from the group consisting of alkylene oxide adducts of alkynediols having an HLB value of 4-12.

[0035] The content of component (C) is preferably 0.5 to 10.0 mass % based on the total amount of the active ingredients, and more preferably 1.0 to 5.0 mass %.

[0036] <Other ingredients> The active ingredient may contain ingredients other than the ingredients (A), (B) and (C) (hereinafter also referred to as "other ingredients"), as long as the object of the present invention is not impaired. Other components include additives such as surfactants, pH adjusters, water retention improvers, antifoaming agents, metal deactivators, disinfectants / preservatives, rust inhibitors, and antioxidants other than the compounds corresponding to component (A), component (B), and component (C). The other components may be used alone or in combination of two or more.

[0037] Examples of surfactants other than the compounds corresponding to component (A), component (B), and component (C) include anionic surfactants, cationic surfactants, nonionic surfactants other than the compounds corresponding to component (A), and amphoteric surfactants. Examples of anionic surfactants include alkylbenzene sulfonates, alpha olefin sulfonates, etc. Examples of cationic surfactants include quaternary ammonium salts such as alkyltrimethylammonium salts, dialkyldimethylammonium salts, and alkyldimethylbenzylammonium salts. Examples of nonionic surfactants other than the compounds corresponding to component (A), component (B) and component (C) include amides such as fatty acid alkanolamides. Examples of amphoteric surfactants include alkyl betaines as betaine surfactants.

[0038] The pH adjuster is mainly used to adjust the pH of the machining fluid. Examples of the pH adjuster include various acid components and base components, and the pH of the machining fluid can be adjusted appropriately by adjusting the content ratio of these components. The acid component and the base component may react with each other to form a salt. Therefore, when an acid component and a base component are used as pH adjusters, if a reaction product of the acid component and the base component is present in the machining fluid, the contents of the acid component and the base component that contributed to the reaction can be calculated from the contents of the reaction product of the acid component and the base component, as described above. In this case, the machining fluid can be considered to contain the acid component and the base component before the reaction, instead of the reaction product.

[0039] Examples of acid components used as pH adjusters include various fatty acids such as lauric acid, stearic acid, oleic acid, linoleic acid, linolenic acid, neodecanoic acid, isononanoic acid, capric acid, and isostearic acid; carboxylic acids such as acetic acid, malic acid, and citric acid; polymeric acids such as polyacrylic acid and salts thereof; and inorganic acids such as phosphoric acid. Among these, fatty acids are preferred, and fatty acids having 12 or less carbon atoms such as neodecanoic acid, isononanoic acid, capric acid, and dodecanedioic acid are more preferred, with one or more selected from the group consisting of neodecanoic acid, isononanoic acid, capric acid, and dodecanedioic acid being even more preferred.

[0040] Examples of base components used as pH adjusters include alkanolamines such as monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, tri-n-propanolamine, tri-n-butanolamine, triisobutanolamine, tri-tert-butanolamine, N-methylethanolamine, N-ethylethanolamine, N-butylethanolamine, N-cyclohexylethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, N-cyclohexyldiethanolamine, N,N-dimethylethanolamine, and N,N-diethylethanolamine; alkylamines such as methylamine, dimethylamine, ethylamine, diethylamine, propylamine, and dipropylamine; and ammonia. Among these, tertiary amines are preferred, and at least one selected from the group consisting of triethanolamine, triisopropanolamine, N-methyldiethanolamine, and N-cyclohexyldiethanolamine is more preferred.

[0041] Examples of water retention enhancers include ethylene glycol, propylene glycol, 1,4-butanediol, hexamethylene glycol, neopentyl glycol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, glycerin, ester derivatives thereof, ether derivatives thereof, polyethylene glycol, polypropylene glycol, and the like. Antifoaming agents include, for example, silicone oil, fluorosilicone oil, polyether polysiloxane, and fluoroalkyl ether. Metal deactivators include, for example, imidazolines, pyrimidine derivatives, thiadiazoles, and benzotriazoles. Examples of disinfectants and preservatives include parahydroxybenzoic acid esters (parabens), as well as benzoic acid, salicylic acid, sorbic acid, dehydroacetic acid, p-toluenesulfonic acid and their salts, and phenoxyethanol. Examples of the rust inhibitor include alkylbenzene sulfonate, dinonylnaphthalene sulfonate, alkenyl succinate ester, and polyhydric alcohol ester. Examples of antioxidants include phenolic antioxidants and amine antioxidants.

[0042] When the working fluid of the present embodiment contains other components, the total content of the other components may be 0.10% by mass or more, 0.20% by mass or more, or 0.30% by mass or more, based on the total amount of the active ingredients, or 30.00% by mass or less, 20.00% by mass or less, 10.00% by mass or less, 5.00% by mass or less, or 3.00% by mass or less.

[0043] <Water> The machining fluid of this embodiment contains water. The water is not particularly limited, and purified water such as distilled water or ion-exchanged water (deionized water); tap water; industrial water; etc. can be used, and purified water or ion-exchanged water (deionized water) is preferred, and ion-exchanged water (deionized water) is more preferred.

[0044] The amount of water contained is adjusted appropriately depending on the manner in which the machining fluid is used. For example, when the working fluid of this embodiment is used to process a workpiece (e.g., cutting a brittle material with a multi-wire saw), the water content in the working fluid (hereinafter also referred to as the "water content of the first embodiment") is, based on 100% by mass of the total working fluid, preferably 95.000% by mass or more, more preferably 97.500% by mass or more, even more preferably 99.500% by mass or more, and particularly preferably 99.600% by mass or more, from the viewpoints of improving the flame retardancy of the working fluid and enhancing safety, and reducing the viscosity of the working fluid and improving handleability. Furthermore, from the viewpoint of ensuring the amount of active ingredient in the working fluid, the water content is preferably 99.910% by mass or less, more preferably 99.900% by mass or less, even more preferably 99.890% by mass or less, even more preferably 99.880% by mass or less, and particularly preferably 99.870% by mass or less. In addition, from the viewpoints of transportation efficiency and storage efficiency, etc., the processing liquid of the present embodiment may be one in which the water in the processing liquid is reduced and concentrated. For example, it may be a concentrated product in which the water in the processing liquid is reduced and concentrated 20 to 2,000 times. And it may be diluted 20 to 2,000 times with water during use (when processing the workpiece).

[0045] (Content of active ingredient) When the water content of the processing liquid of the present embodiment is the water content of the above first aspect, the content of the active ingredient is preferably 0.0100% by mass or more based on 100% by mass of the total amount of the processing liquid. By having the content of the active ingredient be 0.0100% by mass or more, the composition balance of the processing liquid can be made good, and the effects of the present invention can be easily improved. Here, from the viewpoint of more easily improving the effects of the present invention, the content of the active ingredient is preferably 0.0150% by mass or more, more preferably 0.0200% by mass or more, still more preferably 0.0250% by mass or more based on 100% by mass of the total amount of the processing liquid. Also, from the viewpoint of the solubility of the active ingredient in water, the content of the active ingredient is preferably 0.100% by mass or less, more preferably 0.0800% by mass or less, still more preferably 0.0700% by mass or less based on the total amount of the processing liquid.

[0046] (Total content of component (A) and component (B)) In the processing liquid of the present embodiment, the total content of component (A) and component (B) is preferably 50-to 100% by mass, more preferably 60-to 100% by mass, still more preferably 70-to 100% by mass, and particularly preferably 80-to 100% by mass.

[0047] [Physical properties of the processing liquid] The processing liquid of the present embodiment preferably satisfies the following physical property values.

[0048] <Si friction coefficient> The Si friction coefficient of the working fluid of this embodiment is preferably 0.30 or more, more preferably 0.32 or more, and even more preferably 0.35 or more, from the viewpoint of the cutting performance of the working fluid, and is preferably 0.75 or less, more preferably 0.70 or less, and even more preferably 0.65 or less, from the viewpoint of imparting appropriate lubricity to the working fluid. In this specification, the Si friction coefficient of the machining fluid is a value measured using the method described in the examples below.

[0049] [Method of manufacturing machining fluid] The manufacturing method of the working fluid of the present embodiment is not particularly limited. For example, the manufacturing method of the working fluid of the present embodiment is a manufacturing method of a working fluid containing an active ingredient and water, mixing the active ingredient with the water; The active ingredient contains the following components (A) and (B): Component (A): One or more selected from alkylene glycol, epichlorohydrin, and unmodified polyoxyalkylene compounds Component (B): Epichlorohydrin-modified polyoxyalkylene compound

[0050] The order in which component (A) and component (B) are mixed is not particularly limited. For example, component (A) and component (B) may be mixed sequentially or simultaneously with water, or component (A) and component (B) may be mixed in advance, and the mixture may be mixed with water. In addition, in the production method, component (A) and component (B) are blended with water, and component (C) and other components may also be blended as necessary. In this case, the order in which the components are blended, the blending method, etc. are not particularly limited. Since component (A), component (B), water, and other components are the same as those described above, and the preferred embodiments thereof are also the same, detailed descriptions thereof will be omitted. Furthermore, the preferred amounts and ratios of the components (A), (B), water, component (C), and other components are the same as the respective contents and ratios of the respective contents in the working fluid described above, and detailed descriptions thereof will be omitted.

[0051] [Uses of machining fluid] The machining fluid of this embodiment can suppress wire breakage even when the wires are thinned and the wire spacing is narrowed in a multi-wire saw device, and has appropriate lubricity and excellent cleanliness. Therefore, the machining fluid of this embodiment can be suitably used when cutting a workpiece made of a brittle material using a multi-wire saw device. Fixed abrasive wires can be suitably used as the wires that make up the multi-wire saw device. The machining fluid of this embodiment can be used not only for cutting using a multi-wire saw device, but also for cutting using a single-wire saw device, and the wire constituting the single-wire saw device may be a fixed abrasive wire.

[0052] Examples of brittle materials include crystalline silicon, sapphire, gallium nitride, silicon carbide, neodymium magnet, quartz crystal, and glass. The machining fluid of the present embodiment is particularly suitable for cutting crystalline silicon, sapphire, or silicon carbide.

[0053] [Processing methods for brittle materials] The machining fluid of this embodiment can prevent wire breakage even when the wires are thinned and the spacing between them is narrowed in a multi-wire saw device, and has appropriate lubricity and excellent cleanliness. Therefore, according to the working fluid of the present embodiment, a method for cutting a workpiece made of a brittle material with a multi-wire saw device using the working fluid is provided. As the wire constituting the multi-wire saw device, a fixed abrasive wire can be suitably used. The working fluid of this embodiment also provides a method for cutting a workpiece made of a brittle material with a single wire saw device using the working fluid.

[0054] <Multi-wire saw device> The multi-wire saw device mentioned in the application of the working fluid and the method for processing brittle materials of this embodiment will be described. A multi-wire saw device used in cutting processes, for example, has two or more guide rollers with multiple grooves carved at regular intervals, with one wire wound around each groove, and each wire held parallel with a constant tension. During cutting, the guide rollers are rotated, and working fluid ejected from a nozzle or the like is applied to the wire while the wire travels in one or both directions, and cutting is performed by pressing a silicon ingot against the wire to which the working fluid is applied. If necessary, processing may also be performed while the working fluid is applied to the workpiece itself, such as a silicon ingot. The machining fluid used in machining is stored in a tank or the like and transported from there to the machining chamber nozzle via piping or the like. The machining fluid used during cutting is collected in a used machining fluid receiving tank or the like located below the cutting device. In some cases, the fluid is circulated within the device and reused. The wires constituting the multi-wire saw device preferably have a wire diameter of 120 μm or less, and the spacing between the wires is preferably 1,100 μm or less.

[0055] The spacing between the wires used in processing the brittle material is set appropriately depending on the thickness required for the wafers to be cut out, but is preferably 1000 μm or less, for example. Also, it is preferably 100 μm or more. [Example]

[0056] The present invention will be specifically described with reference to the following examples, although the present invention is not limited to the following examples.

[0057] [Methods for measuring various physical properties] The properties of the raw materials used in each example and comparative example were measured according to the procedures shown below.

[0058] (1) Cloud point of 1% by mass aqueous solution The cloud points of 1% by mass aqueous solutions of components (B) and (C) were measured by introducing 100 mL of a 1% by mass aqueous solution of the components to be measured into a 200 mL beaker, stirring the solution at a rotation speed of 400 rpm using a magnetic stirrer (stirring bar length: 30 mm), and heating the solution from 15°C to the cloud point at a temperature increase rate of 5°C / min, and measuring the liquid temperature at which the appearance of the solution became cloudy. The "cloud point" of the compounds shown in Tables 1 and 2 below refers to the "cloud point of a 1% by mass aqueous solution" of the compound.

[0059] (2) HLB value The HLB value of component (A) was calculated by the Griffin method.

[0060] (3) Mass average molecular weight The mass average molecular weight (Mw) was measured by gel permeation chromatography (GPC). GPC was performed using two "TSKgel (registered trademark) SuperMultiporeHZ-M" columns manufactured by Tosoh Corporation, tetrahydrofuran as an eluent, and a refractive index detector as a detector. The mass average molecular weight (Mw) was determined using polystyrene as a standard sample.

[0061] [Examples 1 to 10, Comparative Examples 1 to 5] The components below were mixed to prepare machining fluids having the compositions shown in Table 1, and the following evaluations were carried out. The numerical units for the blending compositions in Table 1 are "mass %." The details of each component used in preparing the machining fluid having the composition shown in Table 1 are explained below.

[0062] <Component (A)> "EO-PO block copolymer 1" Polyoxyalkylene alkyl ether, the polyoxyalkylene portion of which is a block copolymer of ethylene oxide (EO) and propylene oxide (PO) (terminal methyl group (terminal alkyl group), mass average molecular weight (Mw) = 2,286, EO / PO ratio (molar ratio) = 42 / 58, cloud point of 1% by mass aqueous solution = 43°C) "EO-PO block copolymer 2" Poly(propylene oxide)-poly(ethylene oxide)-poly(propylene oxide) block copolymer (mass average molecular weight (Mw) = 2,150, EO / PO ratio (molar ratio) = 30 / 70, cloud point of 1% by mass aqueous solution = 38°C)

[0063] <Ingredient (B)> "Epichlorohydrin Modified 1" Epichlorohydrin modified EO adduct of alcohols with 9 to 11 carbon atoms "Epichlorohydrin Modified 2" Epichlorohydrin modified 2-ethylhexanol EO adduct

[0064] <Ingredient (C)> "Alkynediol EO adduct" EO adduct of 2,5,8,11-tetramethyl-6-dodecyne-5,8-diol (EO adduct of alkynediol, HLB=8)

[0065] <Water> Ion-exchanged water

[0066] [evaluation] The machining fluids of the Examples and Comparative Examples were diluted at the dilution ratios shown in Table 1, and the resulting diluted solutions were subjected to the following evaluations.

[0067] <Cleanliness> Each dilution was evaluated according to the following procedure. (Cylinder wall contamination evaluation) 50 mL of the diluted solution and 0.2 g of fine powder ("Graphite Powder", Fujifilm Wako Pure Chemical Industries, Ltd., special grade) were placed in a 100 mL measuring cylinder, the measuring cylinder was capped, and the cylinder was vigorously shaken up and down 10 times. The degree of dirt on the upper part of the inner wall of the measuring cylinder was evaluated according to the following criteria, with an evaluation of A being a pass. A: The cylinder wall is slightly soiled with fine powder, and the background near the liquid surface is visible through the surface. B: The cylinder wall is moderately soiled with fine powder, and the background near the liquid surface is somewhat visible. C: The cylinder wall is heavily soiled with fine powder, making it impossible to see the background near the liquid surface.

[0068] <Cutting performance> Using each diluted solution, a reciprocating friction test was carried out under the following test conditions to measure the silicon (Si) friction coefficient. Reciprocating friction tester: Orientec Co., Ltd. "F-2100" (Measurement conditions) Bulb: 3 / 16 inch SUJ2 Test plate temperature: 50℃ Test plate: Polycrystalline silicon (surface polished to a mirror finish) Test plate temperature: 50℃ Sliding speed: 20mm / sec Sliding distance: 20mm Number of round trips: 150 Load capacity: 100g (evaluation) Dilutions with a coefficient of friction value of 0.30 or greater were considered to be acceptable.

[0069] <Diluted solution state> The state of the diluted solution was visually inspected and evaluated according to the following criteria. A: Homogeneous liquid C: Separation

[0070] The composition of each machining fluid and the evaluation results of the diluted solution are shown in Table 1. [Table 1]

[0071] From Table 1, we can see the following: It is clear that the machining fluids of Examples 1 to 10 have excellent cleanliness and exhibit appropriate silicon (Si) friction coefficients. In contrast, the machining fluid of Comparative Example 1 is inferior in cleanliness, the machining fluids of Comparative Examples 2, 3 and 5 have low silicon (Si) friction coefficients and do not show appropriate values, and the machining fluid of Comparative Example 4 does not become uniform when diluted.

Claims

1. A processing fluid containing an active ingredient and water, The active ingredients include the following components (A) and (B), and the content of component (B) is 25.0 mass% or less based on the total amount of the active ingredients. Component (A): one or more selected from alkylene glycols and epichlorohydrin-unmodified polyoxyalkylene compounds Component (B): epichlorohydrin-modified polyoxyalkylene compound

2. The machining fluid according to claim 1 , wherein the component (A) is a polyoxyalkylene compound.

3. The processing fluid according to claim 1 or 2, wherein the content of the component (A) is 50 to 99.9 mass% based on the total amount of the active ingredients.

4. The working fluid according to any one of claims 1 to 3, wherein the content of the component (B) is 0.05 to 23.0 mass% based on the total amount of the active ingredients.

5. The working fluid according to any one of claims 1 to 4, wherein the total content of the components (A) and (B) is 50 to 100 mass% based on the total amount of the active ingredients.

6. The working fluid according to any one of claims 1 to 5, which is used when cutting a workpiece made of a brittle material using a multi-wire saw device.

7. The machining fluid according to claim 6 , wherein the wires constituting the multi-wire saw device are fixed abrasive wires.

8. The working fluid according to claim 6 or 7, wherein the brittle material is crystalline silicon, sapphire, silicon carbide, gallium nitride, neodymium magnet, quartz crystal, or glass.

9. The machining fluid according to any one of claims 6 to 8, wherein the wires constituting the multi-wire saw device have a wire diameter of 120 µm or less and a wire spacing of 1,100 µm or less.

10. A method for producing a processing fluid containing an active ingredient and water, comprising: mixing the active ingredient with the water; A method for producing a machining fluid, wherein the active ingredients contain the following components (A) and (B), and the content of component (B) is 25.0 mass% or less based on the total amount of the active ingredients: Component (A): one or more selected from alkylene glycols and epichlorohydrin-unmodified polyoxyalkylene compounds Component (B): epichlorohydrin-modified polyoxyalkylene compound

Images