Water-based processing fluid

Abstract

Provided is an aqueous processing liquid comprising: a compound (A), which is represented by general formula (a-1) and has a weight‐average molecular weight of 12,000 or more; and a water-insoluble polyoxyalkylene ether (B). The viscosity at 25℃ of the aqueous processing liquid is 4.0-20.0 mPa・s. (In the formula, A is a C2-4 alkylene group and, when more than one A is present, each A may be the same or different. m is an integer of 1 or higher.)

Description

[Technical Field]

[0001] The present invention relates to an aqueous machining fluid, a concentrate for an aqueous machining fluid, the use of the aqueous machining fluid, and a method for machining brittle materials using the aqueous machining fluid. [Background technology]

[0002] In the manufacture of semiconductor products, it is necessary to cut silicon ingots, which are brittle materials, and wire sawing is generally used from the viewpoint of cutting accuracy and productivity. Here, there are two methods for cutting silicon ingots: the free abrasive method, in which the silicon ingot is cut with abrasive grains dispersed in the processing fluid, and the fixed abrasive method, in which the silicon ingot is cut with abrasive grains fixed to the surface of the wire. Various processing fluids suitable for each abrasive method have been proposed. For example, Patent Document 1 discloses an invention relating to a water-soluble working fluid composition for fixed abrasive wire saws, which is used to cut workpiece materials other than rare earth magnets, and which is characterized by containing (A) glycols. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-82334 Summary of the Invention [Problem to be solved by the invention]

[0004] Under these circumstances, there is a demand for a new aqueous machining fluid that is easier to apply to the cutting process of brittle materials than conventional fluids. [Means for solving the problem]

[0005] The present invention provides an aqueous machining fluid that has a specific structure, contains an ether compound of a specific molecular weight, and a water-insoluble polyoxyalkylene ether, and is adjusted to a predetermined viscosity. Specifically, the present invention provides, for example, the following aspects [1] to

[15] . [1] An aqueous machining fluid containing a compound (A) represented by the following general formula (a-1) and having a weight-average molecular weight of 12,000 or less, and a water-insoluble compound (B) having a polyoxyalkylene group, The aqueous machining fluid has a viscosity of 4.0 to 26.0 mPa·s at 25°C. [ka] (In the above formula, A is an alkylene group having 2 to 4 carbon atoms, and when there are multiple As, the multiple As may be the same or different, and m is an integer of 1 or greater.) [2] The aqueous machining fluid according to [1] above, wherein the surface tension of the aqueous machining fluid is 45.0 mN / m or less. [3] The aqueous working fluid according to the above [1] or [2], wherein the content of component (A) is 15.0 to 95.0 mass % based on the total amount of the aqueous working fluid. [4] The aqueous working fluid according to any one of the above [1] to [3], wherein the content of component (B) is 0.0001 to 1.0 mass % based on the total amount of the aqueous working fluid. [5] The aqueous working fluid according to any one of the above [1] to [4], wherein the content ratio of component (B) to 100 parts by mass of component (A) is 0.0001 to 1.80 parts by mass. [6] The aqueous working fluid according to any one of the above [1] to [5], wherein the component (A) comprises one or more selected from diethylene glycol, dipropylene glycol, polyethylene glycol, and polypropylene glycol. [7] The aqueous machining fluid according to any one of the above [1] to [6], wherein the component (B) comprises at least one member selected from the group consisting of a water-insoluble polyoxyalkylene ether (B1) represented by the following general formula (b-1) and an alkylene oxide adduct of a water-insoluble acetylene glycol (B2) represented by the following general formula (b-2): [ka] [In the above formula, A 1 ~A 3 are each independently an alkylene group having 2 to 4 carbon atoms. R a ~R e are each independently a hydrogen atom, an alkyl group, a cycloalkyl group which may have an alkyl group, or an aryl group which may have an alkyl group. R 1 ~R 3 are each independently an alkyl group, a cycloalkyl group which may have an alkyl group, or an aryl group which may have an alkyl group. n, p, and q each independently represent an integer of 1 or greater. [8] The aqueous working fluid according to any one of the above [1] to [7], further comprising water (C). [9] The aqueous working fluid according to the above [8], wherein the content of component (C) is 5.0 to 70.0 mass % based on the total amount of the aqueous working fluid.

[10] The aqueous working fluid according to any one of the above [1] to [9], wherein the aqueous working fluid has a pH of 4.0 to 10.0.

[11] The aqueous working fluid according to any one of the above [1] to

[10] , which is used when cutting brittle materials with a wire saw.

[12] A concentrate for an aqueous machining fluid, comprising: a compound (A) represented by the following general formula (a-1) and having a weight-average molecular weight of 12,000 or less; and a water-insoluble compound (B) having a polyoxyalkylene group: [ka] (In the above formula, A is an alkylene group having 2 to 4 carbon atoms, and when there are multiple As, the multiple As may be the same or different, and m is an integer of 1 or greater.)

[13] The concentrate for an aqueous machining fluid according to

[12] above, which can be diluted with water to prepare an aqueous machining fluid having a viscosity of 4.0 to 20.0 mPa·s at 25°C.

[14] Use of the aqueous working fluid according to any one of the above [1] to

[11] in a cutting process of a brittle material with a wire saw.

[15] A method for processing a brittle material, comprising the step of cutting the brittle material with a wire saw by applying the aqueous processing fluid according to any one of the above [1] to

[11] . [Effects of the Invention]

[0006] The aqueous machining fluid of a preferred embodiment of the present invention has various properties that can improve processability (e.g., appropriate viscosity characteristics, low surface tension, and good defoaming properties), and therefore can be an aqueous machining fluid that is suitable for processing brittle materials. DETAILED DESCRIPTION OF THE INVENTION

[0007] Regarding the numerical ranges described herein, the upper and lower limits can be combined in any combination. For example, when a numerical range is described as "preferably 30 to 100, more preferably 40 to 80," the ranges "30 to 80" and "40 to 100" are also included in the numerical ranges described herein. Furthermore, when a numerical range is described as "preferably 30 or more, more preferably 40 or more, and preferably 100 or less, more preferably 80 or less," the ranges "30 to 80" and "40 to 100" are also included in the numerical ranges described herein. In addition, as a numerical range described in this specification, for example, "60 to 100" means a range of "60 or more and 100 or less." Furthermore, in defining the upper and lower limits described in this specification, the numerical range from the lower limit to the upper limit can be defined by appropriately selecting from the respective options and combining them arbitrarily. Furthermore, a plurality of the various requirements described as preferred embodiments in this specification can be combined.

[0008] [Configuration of aqueous machining fluid] The aqueous machining fluid of the present invention contains a compound (A) represented by the general formula (a-1) and having a weight-average molecular weight of 12,000 or less, and a water-insoluble compound (B) having a polyoxyalkylene group, and has a viscosity adjusted to 4.0 to 26.0 mPa s at 25°C. The aqueous machining fluid of the present invention is a solution that can be used for machining workpieces as is without dilution. On the other hand, the aqueous machining fluid concentrate of the present invention, which will be described later, is a solution that can be diluted with water to form an aqueous machining fluid having the above-mentioned viscosity, and is distinguished from the aqueous machining fluid of the present invention in that it is not a solution that is used directly for machining the workpiece.

[0009] The aqueous working fluid of one embodiment of the present invention contains component (A) and component (B), and is therefore prepared to have various properties that can improve workability, particularly low surface tension.

[0010] Furthermore, the aqueous machining fluid of the present invention has a viscosity of 4.0 to 26.0 mPa·s at 25° C., and has appropriate viscosity characteristics, making it an aqueous machining fluid with excellent workability for brittle materials. In one embodiment of the present invention, the aqueous machining fluid has a viscosity at 25°C of 4.0 mPa·s or more, from the viewpoint of providing an aqueous machining fluid with excellent workability for brittle materials, and is preferably 4.5 mPa·s or more, more preferably 5.0 mPa·s or more, more preferably 5.5 mPa·s or more, more preferably 6.0 mPa·s or more, even more preferably 6.5 mPa·s or more, even more preferably 7.0 mPa·s or more, even more preferably 7.5 mPa·s or more, still more preferably 8.0 mPa·s or more, still more preferably 8.5 mPa·s or more, particularly preferably 9.0 mPa·s or more, and even more preferably 9.5 mPa·s or more, 10.0 mPa·s or more, 10.5 mPa·s or more, 11.0 mPa·s or more, 11. It may be 5 mPa·s or more, 12.0 mPa·s or more, 12.5 mPa·s or more, 13.0 mPa·s or more, 13.5 mPa·s or more, or 14.0 mPa·s or more, or 26.0 mPa·s or less, preferably 25.0 mPa·s or less, more preferably 24.0 mPa·s or less, more preferably 23.0 mPa·s or less, even more preferably 22.0 mPa·s or less, even more preferably 21.0 mPa·s or less, still more preferably 20.5 mPa·s or less, particularly preferably 20.0 mPa·s or less, or may even be 19.0 mPa·s or less, 18.0 mPa·s or less, 17.0 mPa·s or less, 16.0 mPa·s or less, or 15.0 mPa·s or less. In this specification, the viscosity of the aqueous machining fluid at 25°C can be measured by the method described in the examples.

[0011] The aqueous working fluid of one embodiment of the present invention may further contain water (C) from the viewpoint of adjusting the viscosity of the aqueous working fluid to the above-mentioned range. The aqueous working fluid of one embodiment of the present invention may contain one or more compounds selected from carboxylic acids (D) and amine compounds (E) from the viewpoint of providing an aqueous working fluid that can prevent corrosion of equipment and wires. The aqueous working fluid of one embodiment of the present invention may contain additives other than the components (A) to (E) as needed, provided that the effects of the present invention are not impaired.

[0012] In the aqueous working fluid of one embodiment of the present invention, the total content of components (A) and (B) is, based on the total amount (100 mass%) of the aqueous working fluid, preferably more than 15 mass%, more preferably more than 20 mass%, more preferably more than 25 mass%, even more preferably more than 30 mass%, even more preferably more than 35 mass%, still more preferably more than 40 mass%, and particularly preferably more than 45 mass%, and may further be more than 50 mass%, more than 55 mass%, more than 60 mass%, more than 65 mass%, or more than 70 mass%, or may be 100 mass% or less, 98 mass% or less, 96 mass% or less, 95 mass% or less, 93 mass% or less, or 90 mass% or less.

[0013] In the aqueous working fluid of one embodiment of the present invention, the total content of components (A) and (B) is, based on the total amount (100% by mass) of components other than water (C) contained in the aqueous working fluid, preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, still more preferably 95% by mass or more, and particularly preferably 98% by mass or more, and may also be 100% by mass or less, 99.99% by mass or less, 99.90% by mass or less, or 99.80% by mass or less.

[0014] In the aqueous working fluid of one embodiment of the present invention, the total content of components (A), (B), and (C) is, based on the total amount (100 mass%) of the aqueous working fluid, preferably 20 mass% or more, more preferably 30 mass% or more, more preferably 40 mass% or more, even more preferably 50 mass% or more, even more preferably 60 mass% or more, still more preferably 70 mass% or more, and particularly preferably 75 mass% or more, and may further be 80 mass% or more, 85 mass% or more, 90 mass% or more, or 95 mass% or more, or may be 100 mass% or less, 99.999 mass% or less, 99.99 mass% or less, or 99.98 mass% or less. Hereinafter, each component contained in the aqueous machining fluid according to one embodiment of the present invention will be described.

[0015] <Component (A)> The aqueous working fluid of the present invention contains, as component (A), a compound represented by the following general formula (a-1) and having a weight-average molecular weight of 12,000 or less. By including component (A), an aqueous working fluid having excellent workability for brittle materials can be obtained. Component (A) may be used alone or in combination of two or more types. [ka]

[0016] In the general formula (a-1), A is an alkylene group having 2 to 4 carbon atoms, and when there are multiple As, the multiple As may be the same or different. m is an integer of 1 or more, and preferably an integer of 2 or more. Examples of the alkylene group that can be selected as A include alkylene groups having two carbon atoms, such as an ethylene group (-CHCH-) or an ethylidene group (-CH(CH)-); alkylene groups having three carbon atoms, such as a trimethylene group (-CHCHCH-), a propylene group (-CH(CH)CH-), a propylidene group (-CHCHCH-), or an isopropylidene group (-C(CH)-); and alkylene groups having four carbon atoms, such as a tetramethylene group (-CHCHCHCHCH-), a 1-methyltrimethylene group (-CH(CH)CHCH-), a 2-methyltrimethylene group (-CHCH(CH)CH-), or a butylene group (-C(CH)CH-). The alkylene group may be a linear or branched alkylene group.

[0017] In one aspect of the aqueous working fluid of the present invention, from the viewpoint of providing an aqueous working fluid with excellent workability for brittle materials, component (A) preferably contains one or more selected from diethylene glycol, dipropylene glycol, polyethylene glycol, and polypropylene glycol, and more preferably contains one or more selected from diethylene glycol and polyethylene glycol.

[0018] In one embodiment of the aqueous working fluid of the present invention, from the viewpoint of providing an aqueous working fluid with excellent workability for brittle materials, the total content of diethylene glycol and polyethylene glycol is preferably 30 to 100 mass%, more preferably 40 to 100 mass%, more preferably 50 to 100 mass%, more preferably 60 to 100 mass%, even more preferably 70 to 100 mass%, even more preferably 80 to 100 mass%, still more preferably 90 to 100 mass%, and particularly preferably 95 to 100 mass%, based on the total amount (100 mass%) of component (A) contained in the aqueous working fluid.

[0019] From the viewpoint of providing an aqueous working fluid with low surface tension and suitable for workability on brittle materials, the weight average molecular weight of component (A) is 12,000 or less, preferably 10,000 or less, more preferably 8,000 or less, more preferably 6,500 or less, even more preferably 5,000 or less, even more preferably 4,000 or less, still more preferably 3,000 or less, still more preferably 2,000 or less, particularly preferably 1,000 or less, and may even be 900 or less, 800 or less, 700 or less, 600 or less, 500 or less, 450 or less, 400 or less, or 350 or less. Furthermore, there is no particular lower limit on the weight average molecular weight of component (A), and it may be 62 or more, which is the molecular weight of ethylene glycol, which is the smallest molecular weight of component (A), and may further be 65 or more, 70 or more, 80 or more, 90 or more, or 100 or more. In this specification, the weight average molecular weight means a value measured by the method described in the examples.

[0020] In one aspect of the aqueous working fluid of the present invention, the viscosity is adjusted to the above-mentioned range, and from the viewpoint of providing an aqueous working fluid with excellent workability for brittle materials, the content of component (A) is, based on the total amount (100 mass%) of the aqueous working fluid, preferably 15.0 mass% or more, more preferably 20 mass% or more, more preferably 25 mass% or more, even more preferably 30 mass% or more, even more preferably 35 mass% or more, still more preferably 40 mass% or more, particularly preferably 45 mass% or more, and may even be 50 mass% or more, 55 mass% or more, 60 mass% or more, 65 mass% or more, or 70 mass% or more; and is preferably 95.0 mass% or less, more preferably 92.0 mass% or less, more preferably 90.0 mass% or less, even more preferably 87.0 mass% or less, even more preferably 85.0 mass% or less, still more preferably 83.0 mass% or less, and particularly preferably 80.0 mass% or less.

[0021] <Ingredient (B)> The aqueous working fluid of the present invention contains, as component (B), a water-insoluble compound (B) having a polyoxyalkylene group. By including component (B), the surface tension of the aqueous working fluid can be adjusted to be low, and the aqueous working fluid can have excellent workability for brittle materials. The component (B) may be used alone or in combination of two or more types.

[0022] In this specification, the term "water-insoluble compound" refers to a compound that can be determined to be water-insoluble when 0.1 g of the compound is added to 99.9 g of ion-exchanged water at 25°C, stirred, and allowed to stand at 25°C for 24 hours, and the compound is visually observed to remain undissolved.

[0023] The HLB value of component (B) used in one embodiment of the present invention is preferably 10.0 or less, more preferably 9.0 or less, and even more preferably 8.0 or less, from the viewpoint of adjusting the surface tension to a lower value and providing an aqueous working fluid with excellent workability for brittle materials. Furthermore, it may be 7.0 or less, 6.0 or less, 5.0 or less, or 4.0 or less, or may be greater than 0, 1.0 or more, or 2.0 or more. In this specification, the HLB value means a value calculated by the Griffon method.

[0024] From the viewpoint of adjusting the surface tension to a lower level and providing an aqueous working fluid with excellent workability for brittle materials, component (B) used in one embodiment of the present invention preferably contains at least one selected from water-insoluble polyoxyalkylene ethers (B1) represented by the following general formula (b-1) and water-insoluble alkylene oxide adducts of acetylene glycols (B2) represented by the following general formula (b-2). [ka]

[0025] In the general formulas (b-1) and (b-2), A 1 ~A 3 are each independently an alkylene group having 2 to 4 carbon atoms. R a ~R e are each independently a hydrogen atom, an alkyl group, a cycloalkyl group which may have an alkyl group, or an aryl group which may have an alkyl group, and are preferably a hydrogen atom or an alkyl group. R 1 ~R 3 are each independently an alkyl group, a cycloalkyl group which may have an alkyl group, or an aryl group which may have an alkyl group, and are preferably an alkyl group. n, p, and q each independently represent an integer of 1 or greater.

[0026] A 1 ~A 3 Examples of alkylene groups having 2 to 4 carbon atoms that can be selected as A in the general formula (a-1) include the same alkylene groups having 2 to 4 carbon atoms that can be selected as A in the general formula (a-1) above, and are preferably alkylene groups having 2 to 3 carbon atoms, more preferably ethylene, trimethylene, or propylene, and even more preferably ethylene. The alkylene group may be a linear alkylene group or a branched alkylene group.

[0027] Ra ~R e and R 1 ~R 3 Examples of alkyl groups that can be selected as aryl include methyl, ethyl, propyl (n-propyl, isopropyl), butyl (n-butyl, s-butyl, t-butyl, isobutyl), pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, 1,1-dimethylheptyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, and octadecyl. These alkyl groups may be linear or branched. The alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 16, even more preferably 1 to 12, and even more preferably 1 to 10. R a ~R e and R 1 ~R 3 Examples of the cycloalkyl group which may have an alkyl group and which can be selected as (R) include a cyclopentyl group, a cyclohexyl group, a dimethylcyclohexyl group, an ethylcyclohexyl group, a propylcyclohexyl group, a butylcyclohexyl group, a heptylcyclohexyl group, etc. The number of ring carbon atoms of the cycloalkyl group is preferably 5 to 18, more preferably 5 to 12, and even more preferably 6 to 10. R a ~R e and R 1 ~R 3 Examples of the aryl group which may have an alkyl group and which can be selected as (a) include a phenyl group, a naphthyl group, an anthracenyl group, a biphenyl group, a terphenyl group, a tolyl group, a dimethylphenyl group, a butylphenyl group, a nonylphenyl group, a methylbenzyl group, a dimethylnaphthyl group, etc. The number of ring carbon atoms of the aryl group is preferably 6 to 24, more preferably 6 to 18, and even more preferably 6 to 12.

[0028] The component (B1) used in one embodiment of the present invention is A in the general formula (b-1). 1 is an ethylene group, and R ais a hydrogen atom, and R 1 is preferably a water-insoluble polyoxyalkylene ether in which the alkyl group has 1 to 20 carbon atoms (preferably 1 to 10 carbon atoms). In addition, the component (B2) used in one embodiment of the present invention is A in the general formula (b-2). 2 and A 3 is an ethylene group, and R b and R c is a hydrogen atom, and R d and R e are each independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms (preferably 1 to 6, more preferably 1 to 4, and even more preferably 1 to 3), and R 2 and R 3 are each independently an ethylene oxide adduct of a water-insoluble acetylene glycol, which is an alkyl group (preferably a branched alkyl group) having 1 to 20 carbon atoms (preferably 2 to 16, more preferably 3 to 10, even more preferably 4 to 8, and still more preferably 4 to 6).

[0029] In the aqueous working fluid of one embodiment of the present invention, from the viewpoint of adjusting the surface tension to a lower level and providing an aqueous working fluid with excellent workability for brittle materials, the content of component (B) is preferably 0.0001% by mass or more, more preferably 0.0003% by mass or more, more preferably 0.0005% by mass or more, even more preferably 0.0010% by mass or more, still more preferably 0.0020% by mass or more, still more preferably 0.0030% by mass or more, and particularly preferably 0.0040% by mass or more, based on the total amount (100% by mass) of the aqueous working fluid. % by mass or more, and is preferably 1.0% by mass or less, more preferably 0.80% by mass or less, more preferably 0.50% by mass or less, even more preferably 0.30% by mass or less, even more preferably 0.10% by mass or less, still more preferably 0.080% by mass or less, particularly preferably 0.050% by mass or less, and may further be 0.030% by mass or less, 0.020% by mass or less, 0.010% by mass or less, 0.0090% by mass or less, 0.0080% by mass or less, or 0.0070% by mass or less.

[0030] In the aqueous working fluid of one embodiment of the present invention, from the viewpoint of adjusting the viscosity to the above-mentioned range and further adjusting the surface tension to be smaller, thereby providing an aqueous working fluid with excellent workability for brittle materials, the content ratio of component (B) relative to 100 parts by mass of component (A) is preferably 0.0001 parts by mass or more, more preferably 0.0003 parts by mass or more, more preferably 0.0005 parts by mass or more, even more preferably 0.0010 parts by mass or more, even more preferably 0.0020 parts by mass or more, still more preferably 0.0030 parts by mass or more, and still more preferably or 0.0040 parts by mass or more, particularly preferably 0.0050 parts by mass or more, and is preferably 1.80 parts by mass or less, more preferably 1.70 parts by mass or less, more preferably 1.50 parts by mass or less, even more preferably 1.40 parts by mass or less, still more preferably 1.30 parts by mass or less, particularly preferably 1.25 parts by mass or less, and may even be 1.00 parts by mass or less, 0.500 parts by mass or less, 0.100 parts by mass or less, 0.050 parts by mass or less, 0.020 parts by mass or less, or 0.010 parts by mass or less.

[0031] <Component (C)> The aqueous working fluid of one embodiment of the present invention may further contain water as component (C) from the viewpoint of adjusting the viscosity of the aqueous working fluid to the above-mentioned range. In the aqueous working fluid of one embodiment of the present invention, examples of water used as component (C) include ultrapure water, pure water, distilled water, ion-exchanged water, tap water, and industrial water.

[0032] In the aqueous working fluid of one embodiment of the present invention, the content of component (C) is, based on the total amount (100 mass%) of the aqueous working fluid, preferably 5.0 mass% or more, more preferably 7.0 mass% or more, more preferably 10.0 mass% or more, even more preferably 12.0 mass% or more, even more preferably 15.0 mass% or more, still more preferably 17.0 mass% or more, and particularly preferably 20.0 mass% or more; and is preferably 70.0 mass% or less, more preferably 67.0 mass% or less, more preferably 65.0 mass% or less, even more preferably 63.0 mass% or less, even more preferably 60.0 mass% or less, still more preferably 57.0 mass% or less, particularly preferably 55.0 mass% or less, and may even be 50.0 mass% or less, 45.0 mass% or less, 40.0 mass% or less, 35.0 mass% or less, 30.0 mass% or less, or 27.0 mass% or less.

[0033] <Ingredient (D)> The aqueous working fluid of one embodiment of the present invention may further contain a carboxylic acid as component (D) from the viewpoint of providing an aqueous working fluid that can prevent corrosion of equipment and wires. The component (D) may be used alone or in combination of two or more types.

[0034] Examples of the carboxylic acid used as component (D) in one embodiment of the present invention include saturated monocarboxylic acids, unsaturated monocarboxylic acids, dicarboxylic acids, and tricarboxylic acids. Among these, the carboxylic acid used as component (D) in one embodiment of the present invention is preferably a saturated monocarboxylic acid or an unsaturated monocarboxylic acid, more preferably a saturated monocarboxylic acid, and even more preferably a branched-chain saturated monocarboxylic acid.

[0035] Examples of saturated monocarboxylic acids include linear saturated monocarboxylic acids such as valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, heptadecanoic acid, stearic acid, nonadecanoic acid, arachic acid, and behenic acid; isomyristic acid, isopalmitic acid, isostearic acid, 2,2-dimethylpropanoic acid, and 2,2-dimethylbutanoic acid; Examples of branched-chain saturated monocarboxylic acids include 2,2-dimethylpentanoic acid, 2,2-dimethyloctanoic acid, 2-ethyl-2,3,3-trimethylbutanoic acid, 2,2,3,4-tetramethylpentanoic acid, 2,5,5-trimethyl-2-t-butylhexanoic acid, 2,3,3-trimethyl-2-ethylbutanoic acid, 2,3-dimethyl-2-isopropylbutanoic acid, 2-ethylhexanoic acid, and 3,5,5-trimethylhexanoic acid (isononanoic acid). Among these, branched-chain saturated monocarboxylic acids are preferred, and 3,5,5-trimethylhexanoic acid (isononanoic acid) is more preferred. Examples of unsaturated monocarboxylic acids include undecylenic acid, oleic acid, elaidic acid, erucic acid, nervonic acid, linoleic acid, γ-linolenic acid, arachidonic acid, α-linolenic acid, stearidonic acid, eicosapentaenoic acid, and docosahexaenoic acid. Examples of dicarboxylic acids include adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, brassylic acid, and tetradecanedioic acid. Examples of tricarboxylic acids include propanetricarboxylic acid, propane-1-ene-1,2,3-tricarboxylic acid, butanetricarboxylic acid, pentanetricarboxylic acid, hexanetricarboxylic acid, octanetricarboxylic acid, nonanetricarboxylic acid, decanetricarboxylic acid, undecanetricarboxylic acid, and monomethyldecanetricarboxylic acid.

[0036] In one embodiment of the aqueous working fluid of the present invention, from the viewpoint of providing an aqueous working fluid that can prevent corrosion of equipment and wires, the content of component (D) is, based on the total amount (100 mass%) of the aqueous working fluid, preferably 0.001 mass% or more, more preferably 0.003 mass% or more, even more preferably 0.005 mass% or more, still more preferably 0.007 mass% or more, and particularly preferably 0.009 mass% or more, and is also preferably 3.0 mass% or less, more preferably 2.0 mass% or less, more preferably 1.0 mass% or less, even more preferably 0.50 mass% or less, still more preferably 0.20 mass% or less, and particularly preferably 0.10 mass% or less.

[0037] <Ingredient (E)> The aqueous working fluid of one embodiment of the present invention may further contain an amine compound as component (E) from the viewpoint of providing an aqueous working fluid that can prevent corrosion of equipment and wires. The component (E) may be used alone or in combination of two or more types.

[0038] Examples of the amine compound used as component (E) in one embodiment of the present invention include alkylamines, alkanolamines, and polyalkylenepolyamines. Among these, the amine compound used as component (E) in one embodiment of the present invention is preferably an alkanolamine, and more preferably an alkanolamine having 2 to 6 carbon atoms.

[0039] Examples of alkylamines include primary aliphatic alkylamines such as monomethylamine, monoethylamine, monopropylamine, monobutylamine, and monopentylamine; and secondary aliphatic alkylamines such as dimethylamine, methylethylamine, diethylamine, methylpropylamine, and ethylpropylamine. Examples of alkanolamines include monomethanolamine, monoethanolamine, monopropanolamine, monoisopropanolamine, monobutanolamine, dimethanolamine, methanolethanolamine, diethanolamine, methanolpropanolamine, ethanolpropanolamine, dipropanolamine, diisopropanolamine, trimethanolamine, triethanolamine, tripropanolamine, triisopropanolamine, tributanolamine, and monobutyldiethanolamine. Among these alkanolamines, alkanolamines having 2 to 6 carbon atoms are preferred, and one or more selected from monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, and triisopropanolamine are more preferred, and one or more selected from triethanolamine and triisopropanolamine are even more preferred, with triisopropanolamine being even more preferred. Examples of polyalkylene polyamines include diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexaethyleneheptamine, tetrapropylenepentamine, and hexabutyleneheptamine.

[0040] In one embodiment of the present invention, from the viewpoint of providing an aqueous working fluid that can prevent corrosion of equipment and wires, the content of component (E) is, based on the total amount (100 mass%) of the aqueous working fluid, preferably 0.001 mass% or more, more preferably 0.005 mass% or more, even more preferably 0.007 mass% or more, still more preferably 0.010 mass% or more, and particularly preferably 0.015 mass% or more, and is preferably 5.0 mass% or less, more preferably 3.0 mass% or less, even more preferably 2.0 mass% or less, still more preferably 1.0 mass% or less, particularly preferably 0.70 mass% or less, and may even be 0.50 mass% or less, 0.30 mass% or less, 0.20 mass% or less, 0.10 mass% or less, 0.070 mass% or less, or 0.050 mass% or less.

[0041] In one embodiment of the aqueous working fluid of the present invention, from the viewpoint of providing an aqueous working fluid that can prevent corrosion of equipment and wires, the content ratio of component (D) to component (E) [(D) / (E)], in mass ratio, is preferably 0.01 or more, more preferably 0.05 or more, more preferably 0.10 or more, even more preferably 0.20 or more, still more preferably 0.30 or more, and particularly preferably 0.40 or more, and is also preferably 1.2 or less, more preferably 1.0 or less, more preferably 0.90 or less, even more preferably 0.80 or less, still more preferably 0.75 or less, and particularly preferably 0.70 or less.

[0042] <Other additives> The aqueous working fluid of one embodiment of the present invention may further contain additives other than the above components (A) to (E) as needed, provided that the effects of the present invention are not impaired. Examples of such other additives include rust inhibitors (alkylbenzene sulfonates, dinonylnaphthalene sulfonates, alkenyl succinate esters, polyhydric alcohol esters, etc.), friction modifiers (various nonionic surfactants, etc.), antifoaming agents (silicone oils, fluorosilicone oils, fluoroalkyl ethers, etc.), metal deactivators (imidazolines, pyrimidine derivatives, thiadiazoles, benzotriazoles, etc.), disinfectants and preservatives (parahydroxybenzoic acid esters; benzoic acid, salicylic acid, sorbic acid, dehydroacetic acid, p-toluenesulfonic acid, and their salts; phenoxyethanol, etc.), and pH adjusters (organic acids such as acetic acid, malic acid, and citric acid, and their salts; phosphoric acid, etc., and their salts). These additives may be used alone or in combination of two or more.

[0043] In the aqueous working fluid of one embodiment of the present invention, the content of each of these various additives is appropriately set depending on the type and function of each component, but may be 0.0001 mass % or more, 0.005 mass % or more, 0.01 mass % or more, 0.05 mass % or more, or 0.1 mass % or more, based on the total amount (100 mass %) of the aqueous working fluid, or may be 20 mass % or less, 10 mass % or less, 5 mass % or less, 2 mass % or less, or 1 mass % or less.

[0044] <Method of manufacturing aqueous machining fluid> The method for producing the aqueous working fluid of one embodiment of the present invention is not particularly limited, and is preferably a method including a step of blending components (A) and (B), and, as necessary, components (C) to (E) and other additives. For example, when producing an aqueous working fluid containing water as component (C), the fluid can be produced by blending components (A) and (B), and, if necessary, components (C) to (E) and other additives, with water, followed by stirring as necessary. The order of blending the components can be determined as appropriate.

[0045] [Properties of aqueous machining fluid] In one aspect of the present invention, the aqueous machining fluid preferably has a smaller surface tension, from the viewpoint of providing an aqueous machining fluid with excellent workability for brittle materials. From the above viewpoints, the surface tension of the aqueous machining fluid of one embodiment of the present invention is preferably 45.0 mN / m or less, more preferably 43.0 mN / m or less, more preferably 40.0 mN / m or less, even more preferably 38.0 mN / m or less, still more preferably 36.0 mN / m or less, and particularly preferably 35.0 mN / m or less, and may also be 1.0 mN / m or more, 3.0 mN / m or more, 5.0 mN / m or more, 7.0 mN / m or more, 10.0 mN / m or more, or 15.0 mN / m or more. In this specification, the surface tension of the aqueous machining fluid refers to a value measured in accordance with the platinum plate method of JIS K2241.

[0046] From the viewpoint of suppressing the occurrence of rust on the processing equipment and preventing corrosion of the workpiece, the pH of the aqueous processing fluid of one embodiment of the present invention is preferably 4.0 to 10.0, more preferably 5.0 to 9.0, even more preferably 6.0 to 8.5, and still more preferably 7.0 to 8.0. The pH of the aqueous machining fluid is the value measured at 25° C. in accordance with JIS Z8802.

[0047] 90 mL of the aqueous machining fluid of one embodiment of the present invention is placed in a 100 mL measuring cylinder, the measuring cylinder is covered, and the cylinder is vigorously shaken up and down 10 times. After allowing to stand for 10 seconds, the amount of foam generated is preferably 15 mL or less, more preferably 10 mL or less, even more preferably 9.0 mL or less, still more preferably 8.0 mL or less, particularly preferably 7.5 mL or less, and even more preferably less than 6.0 mL, less than 5.0 mL, less than 4.0 mL, less than 3.5 mL, less than 3.0 mL, less than 2.5 mL, less than 2.0 mL, less than 1.5 mL, or less than 1.0 mL. The amount of foam is a value measured based on the method described in the Examples below.

[0048] [Concentrated liquid for aqueous processing liquid] The present invention also provides a concentrate for an aqueous machining fluid, comprising a compound (A) represented by the general formula (a-1) and having a weight-average molecular weight of 12,000 or less, and a water-insoluble compound (B) having a polyoxyalkylene group. By diluting the aqueous working fluid concentrate of the present invention with water, it is possible to prepare an aqueous working fluid having a viscosity of 4.0 to 20.0 mPa s at 25° C. In other words, by diluting the aqueous working fluid concentrate of the present invention with water, it is possible to prepare the aqueous working fluid of one aspect of the present invention described above.

[0049] In the aqueous working fluid concentrate according to one embodiment of the present invention, the content ratio of component (B) relative to 100 parts by mass of component (A) is preferably 0.0001 parts by mass or more, more preferably 0.0003 parts by mass or more, more preferably 0.0005 parts by mass or more, even more preferably 0.0010 parts by mass or more, even more preferably 0.0020 parts by mass or more, still more preferably 0.0030 parts by mass or more, still more preferably 0.0040 parts by mass or more, and particularly preferably 0.00 It is 50 parts by mass or more, and preferably 1.80 parts by mass or less, more preferably 1.70 parts by mass or less, more preferably 1.50 parts by mass or less, even more preferably 1.40 parts by mass or less, even more preferably 1.30 parts by mass or less, and particularly preferably 1.25 parts by mass or less, and may further be 1.00 parts by mass or less, 0.500 parts by mass or less, 0.100 parts by mass or less, 0.050 parts by mass or less, 0.020 parts by mass or less, or 0.010 parts by mass or less.

[0050] Furthermore, the concentrate for an aqueous working fluid according to one embodiment of the present invention may contain, in addition to the components (A) and (B), the components (D) and (E) and the other additives described above. In the concentrate for an aqueous working fluid according to one embodiment of the present invention, specific aspects (including preferred aspects) of the components (A) and (B), the components (D) and (E), and the other additives described above are the same as those described above for each component of the aqueous working fluid according to one embodiment of the present invention.

[0051] In the aqueous working fluid concentrate according to one embodiment of the present invention, the total content of components (A) and (B) is, based on the total amount (100% by mass) of the aqueous working fluid concentrate, preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, still more preferably 95% by mass or more, and particularly preferably 98% by mass or more, and may also be 100% by mass or less, 99.99% by mass or less, 99.90% by mass or less, or 99.80% by mass or less.

[0052] [Applications of aqueous machining fluids, uses of aqueous machining fluids, and methods for machining brittle materials] The aqueous machining fluid of a preferred embodiment of the present invention contains components (A) and (B) and has a viscosity at 25°C adjusted to a specific range. As a result, the aqueous machining fluid has various properties that can improve processability (such as appropriate viscosity characteristics, low surface tension, and good defoaming properties), making it suitable for use in machining brittle materials. In particular, the aqueous machining fluid of a preferred embodiment of the present invention has appropriate viscosity characteristics, low surface tension, and good defoaming properties, making it suitable as an aqueous machining fluid used when cutting brittle materials with a wire saw, and is even more suitable as an aqueous machining fluid for a fixed abrasive method in which brittle materials are cut using a wire with abrasive grains fixed to its surface in advance. The aqueous machining fluid of one embodiment of the present invention enables high-precision cutting of brittle materials using a fixed abrasive method.

[0053] Examples of brittle materials to be processed include silicon ingots, quartz, carbon, and glass, with silicon ingots being preferred. The diameter of the wire for the fixed abrasive method may be 0.2 mm or less, 0.12 mm or less, 0.1 mm or less, or 0.08 mm or less, or 0.01 mm or more, 0.02 mm or more, 0.03 mm or more, 0.04 mm or more, 0.05 mm or more, or 0.06 mm or more. Although smaller diameter wires can increase the yield of products from brittle materials, they also tend to reduce the brittleness of the workpiece, resulting in lower cutting efficiency. In contrast, the aqueous machining fluid of one embodiment of the present invention can improve the abrasive grain adhesion and increase cutting efficiency, allowing the use of smaller diameter wires. Furthermore, the aqueous machining fluid of one embodiment of the present invention has low surface tension, which reduces the repulsive force between wires, preventing twisting of the wires and improving workability.

[0054] In consideration of the above-mentioned characteristics of the aqueous machining fluid of one embodiment of the present invention, the present invention can also provide the following [1] and [2]. [1] Use of the aqueous machining fluid according to one embodiment of the present invention described above in a cutting process of a brittle material using a wire saw. [2] A method for processing a brittle material, comprising a step of cutting the brittle material with a wire saw by applying the aqueous processing fluid according to one embodiment of the present invention.

[0055] The cutting steps in [1] and [2] above are preferably carried out by a fixed abrasive method in which a wire with abrasive grains fixed to its surface is used to cut the brittle material. Specific examples of the wire and brittle material used in the wire saw are as described above. [Example]

[0056] Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples in any way. In the following examples, the following physical property values ​​were measured and calculated as follows. (1) Weight average molecular weight Measurement was carried out using a gel permeation chromatograph (Agilent Technologies, "1260 Model HPLC") under the following conditions, and the values ​​measured were converted into standard polystyrene values. (Measurement conditions) Column: Two Shodex LF404 columns connected in series. Column temperature: 35℃ Developing solvent: chloroform ·Flow rate: 0.3mL / min (2) HLB Calculation was performed using the Griffin method.

[0057] Examples 1 to 10, Comparative Examples 1 to 7 Aqueous machining fluids were prepared by adding and mixing various components of the types shown in Tables 1 and 2 in the amounts shown in Tables 1 and 2. Details of each component used in preparing the aqueous machining fluids are as follows.

[0058] <(Poly)alkylene glycol> DEG: Diethylene glycol ·PEG200: Polyethylene glycol with a weight average molecular weight of 200. ·PEG400: Polyethylene glycol with a weight average molecular weight of 400. ·PEG600: Polyethylene glycol with a weight average molecular weight of 600. ·PEG13000: Polyethylene glycol with a weight-average molecular weight of 13,000. <Compounds Having a Polyoxyalkylene Group> Water-insoluble polyoxyethylene ether: aliphatic polyoxyethylene ether, A in the general formula (b-1) 1 is an ethylene group, R a is a hydrogen atom, R 1 is an alkyl group having 1 to 10 carbon atoms. Water-insoluble acetylene glycol EO adduct (1): an ethylene oxide adduct of acetylene glycol, A in the general formula (b-2) 2 and A 3 is an ethylene group, R b and R c is a hydrogen atom, R d and R e is a methyl group, R 2 and R 3 isobutyl group, water-insoluble compound, water-insoluble, HLB=8 Water-insoluble acetylene glycol EO adduct (2): an ethylene oxide adduct of acetylene glycol, A in the general formula (b-2) 2 and A 3 is an ethylene group, R b and R c is a hydrogen atom, R d and R e is a methyl group, R 2 and R 3 is an isobutyl group, water-insoluble compound, HLB=4 Water-soluble acetylene glycol EO adduct: Ethylene oxide adduct of acetylene glycol, water-soluble, HLB=13 <Other ingredients> Isononanoic acid Triisopropanolamine Ion-exchanged water

[0059] The prepared aqueous machining fluids were measured for their physical properties of viscosity at 25°C, surface tension, and pH using the following methods, and their defoaming properties were also evaluated using the following methods. The aqueous machining fluids of Example 1 and Comparative Examples 5 and 6 were further evaluated for their workability on brittle materials using the following methods. These results are shown in Tables 1 and 2. In Comparative Example 1, the blended water-insoluble polyoxyethylene ether did not dissolve in water, making it impossible to measure the physical properties and evaluate the defoaming properties. The aqueous machining fluid of Comparative Example 4 had such high viscosity that its defoaming properties could not be evaluated.

[0060] (1) Viscosity at 25°C Measurement was carried out using a B-type rotational viscometer TVB-10 (product name, manufactured by Toki Sangyo Co., Ltd.) at a rotor rotation speed of 60 rpm. (2)Surface tension Measurement was carried out in accordance with the platinum plate method of JIS K2241. (3) pH Measurement was carried out at 25°C in accordance with JIS Z8802.

[0061] (4) Evaluation of antifoaming properties 90 mL of the prepared aqueous machining fluid was placed in a 100 mL measuring cylinder, the measuring cylinder was covered, and the fluid was vigorously shaken up and down 10 times. After leaving the cylinder to stand for 10 seconds, the amount of foam was measured by reading the graduations on the measuring cylinder. The less foam there was, the better the aqueous machining fluid's defoaming properties.

[0062] (5) Evaluation of workability of brittle materials Using a multi-wire saw and fixed abrasive wire (electroplated diamond wire), the single crystal silicon ingot was cut into silicon wafers while the prepared aqueous machining fluid was poured onto the fixed abrasive wire. Then, the TTV (Total Thickness Variation) was measured to evaluate the flatness of the silicon wafer obtained by the above cutting process, and the processability of the brittle material was evaluated based on the following criteria. The TTV used to evaluate flatness is a value expressed as the difference between the maximum and minimum thicknesses measured by a dial gauge for the thickness of the obtained silicon wafer, and the smaller this value, the higher the flatness of the silicon wafer. In this example, a "DIGIMATIC INDICATOR ID-C112CX" (product name, manufactured by Mitutoyo Corporation) was used as the dial gauge. (Evaluation criteria for workability of brittle materials) · A: TTV is less than 10 μm. · B: TTV is 10 μm or more and less than 15 μm. ·C:TTV is 15μm or more.

[0063] [Table 1]

[0064] [Table 2]

[0065] As can be seen from Table 1, the aqueous machining fluids of Examples 1 to 10 have good defoaming properties and excellent workability for brittle materials in terms of viscosity characteristics and surface tension. In fact, the aqueous machining fluid of Example 1 had a TTV value of less than 10 μm, confirming its excellent workability for brittle materials. On the other hand, Table 2 shows that the aqueous machining fluids of Comparative Examples 2 to 5 have either too low or too high viscosity, which is thought to cause problems with the workability of brittle materials. The aqueous machining fluids of Comparative Examples 6 and 7 also have high surface tension, which is thought to cause problems with the workability of brittle materials. In fact, the aqueous machining fluids of Comparative Examples 5 and 6 had TTV values ​​of 10 μm or more, and were confirmed to have inferior workability with brittle materials compared to the aqueous machining fluid of Example 1. The aqueous machining fluid of Comparative Example 1 was terminated without evaluation of its physical properties because the blended water-insoluble polyoxyethylene ether did not dissolve in water.

Claims

1. An aqueous machining fluid comprising: a compound (A) represented by the following general formula (a-1) and having a weight-average molecular weight of 12,000 or less; a water-insoluble compound (B) having a polyoxyalkylene group; and water (C), The content of component (A) is 35% by mass or more based on the total amount of the aqueous machining fluid, The content of component (C) is more than 20.0 mass% based on the total amount of the aqueous machining fluid, The aqueous machining fluid has a viscosity of 4.0 to 26.0 mPa·s at 25°C. 【Chemistry 1】 [In the above formula, A is an alkylene group having 2 to 4 carbon atoms, and when there are multiple As, the multiple As may be the same or different, and m is an integer of 1 or greater.]

2. An aqueous machining fluid comprising: a compound (A) represented by the following general formula (a-1) and having a weight-average molecular weight of 12,000 or less; a water-insoluble compound (B) having a polyoxyalkylene group; and water (C), The content of component (A) is 35% by mass or more based on the total amount of the aqueous machining fluid, The content ratio of component (B) relative to 100 parts by mass of component (A) is less than 0.010 parts by mass, The aqueous machining fluid has a viscosity of 4.0 to 26.0 mPa·s at 25°C. 【Chemistry 2】 [In the above formula, A is an alkylene group having 2 to 4 carbon atoms, and when there are multiple As, the multiple As may be the same or different, and m is an integer of 1 or greater.]

3. 3. The aqueous machining fluid according to claim 1, wherein the surface tension of the aqueous machining fluid is 45.0 mN / m or less.

4. 4. The aqueous working fluid according to claim 1, wherein the content of component (A) is 35 to 95.0 mass % based on the total amount of the aqueous working fluid.

5. 5. The aqueous machining fluid according to claim 1, wherein the content of component (B) is 0.0001 to 1.0 mass % based on the total amount of the aqueous machining fluid.

6. 2. The aqueous working fluid according to claim 1, wherein the content ratio of component (B) to 100 parts by mass of component (A) is 0.0001 to 1.80 parts by mass.

7. 7. The aqueous working fluid according to claim 1, wherein component (A) comprises at least one selected from the group consisting of diethylene glycol, dipropylene glycol, polyethylene glycol, and polypropylene glycol.

8. 8. The aqueous working fluid according to claim 1, wherein the component (B) comprises at least one selected from a water-insoluble polyoxyalkylene ether (B1) represented by the following general formula (b-1) and an alkylene oxide adduct of a water-insoluble acetylene glycol (B2) represented by the following general formula (b-2): 【Transformation 3】 [In the above formula, A １ ~A ３ are each independently an alkylene group having 2 to 4 carbon atoms. R ａ ~R ｅ are each independently a hydrogen atom, an alkyl group, a cycloalkyl group which may have an alkyl group, or an aryl group which may have an alkyl group. R １ ~R ３ are each independently an alkyl group, a cycloalkyl group which may have an alkyl group, or an aryl group which may have an alkyl group. n, p, and q each independently represent an integer of 1 or more.

9. 3. The aqueous machining fluid according to claim 2, wherein the content of component (C) is 5.0 to 70.0 mass % based on the total amount of the aqueous machining fluid.

10. The aqueous machining fluid according to any one of claims 1 to 9, wherein the pH of the aqueous machining fluid is 4.0 to 10.

0.

11. The aqueous working fluid according to any one of claims 1 to 10, which is used when cutting brittle materials with a wire saw.

12. A concentrate for an aqueous machining fluid that can be prepared into the aqueous machining fluid according to any one of claims 1 to 11 by dilution with water, A concentrate for an aqueous machining fluid, comprising: a compound (A) represented by the following general formula (a-1) and having a weight-average molecular weight of 12,000 or less; and a water-insoluble compound (B) having a polyoxyalkylene group; and the concentrate does not contain water: 【Chemistry 4】 [In the above formula, A is an alkylene group having 2 to 4 carbon atoms, and when there are multiple As, the multiple As may be the same or different, and m is an integer of 1 or greater.]

13. The concentrate for an aqueous machining fluid according to claim 12, wherein an aqueous machining fluid having a viscosity of 4.0 to 20.0 mPa·s at 25° C. can be prepared by diluting the concentrate for an aqueous machining fluid with water.

14. Use of the aqueous working fluid according to any one of claims 1 to 11 in a process of cutting brittle materials with a wire saw.

15. A method for processing a brittle material, comprising a step of cutting the brittle material with a wire saw by applying the aqueous processing fluid according to any one of claims 1 to 11.

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