JPWO2013073618A1 - Processing method of cutting oil composition for used fixed abrasive wire saw - Google Patents

Abstract

In the method for treating a used cutting oil composition for a fixed abrasive wire saw (hereinafter abbreviated as “cutting oil composition”), the cutting oil composition before use is a specific polyether compound (component A) 25 to 75. 1 to 9% by weight of a specific surfactant (component B) and water (component C), and the clouding point of the cutting oil composition is 30 to 80 ° C. The powder removal process for removing the cutting powder heats the drained oil to a temperature equal to or higher than the cloud point of the cutting oil composition, and consists mainly of an upper layer mainly composed of a polyether compound, water and the cutting powder. A first step of separating the lower layer from the lower layer, and a second step of removing the lower layer from the separated waste oil.

Description

  The present invention relates to a method for treating a cutting oil composition for a used fixed abrasive wire saw, a method for regenerating a cutting oil composition for a used fixed abrasive wire saw, and a cutting oil composition for a fixed abrasive wire saw.

  Conventionally, what contains a polyether compound as an oil component is known as a cutting oil composition used when cutting a silicon ingot etc. with a wire saw using an abrasive grain (refer patent document 1 and patent document 2).

  In recent years, attempts have been made to facilitate the disposal of used cutting oil compositions from the viewpoint of environmental friendliness and economic efficiency. In addition, from the viewpoint of improving environmental performance, productivity and economy, it has been attempted to reuse the used cutting oil composition. For example, Patent Document 3 below discloses that a dispersion such as abrasive grains and cutting powder of an ingot and a cutting oil composition are separated by centrifugation and the cutting oil composition is reused.

  On the other hand, a method of cutting a silicon ingot or the like using a fixed abrasive wire saw instead of a loose abrasive wire saw is known. This method has an advantage that the ingot can be used effectively because the ingot can be cut less. In addition, since no abrasive grains are mixed in the cutting oil composition, this method is capable of stably producing a wafer with less change in properties such as viscosity of the cutting oil composition at the time of cutting, and easy cleaning of the wafer. Therefore, it is more advantageous than a cutting method using a loose abrasive wire saw.

Japanese Patent Laid-Open No. 11-286693 JP-A-11-323376 JP-A-01-316170

  However, even when a fixed abrasive wire saw is used to cut the ingot, the cutting powder of the ingot is mixed in the cutting oil composition. It is necessary to remove it. In the centrifugal separation method, which is a general removal method, it takes a very long time to separate the cutting powder even if it is rotated at high speed, and the separation efficiency is also poor, so the problem is that the regeneration efficiency of the cutting oil composition is low. It has become. This problem hinders the productivity improvement of silicon wafers. Moreover, even if the technique described in Patent Document 2 is used, the separability of the cutting powder is insufficient. The reason is that the cutting powder has a property that the affinity for the oil is higher than the moisture in the cutting oil composition. Moreover, when discarding a used cutting oil composition, for example, in order to discard by a combustion process, it is desirable to remove cutting powder from the used cutting oil composition as much as possible.

  The present invention makes it possible to separate a cutting powder with high separation efficiency by a simple operation from an oil drainage liquid containing a used cutting oil composition and a cutting powder generated by cutting an ingot. The disposal method of the cutting oil composition for used fixed abrasive wire saws is provided. In addition, the present invention provides a cutting oil composition for a used fixed abrasive wire saw that can improve the regeneration efficiency by separating cutting powder with high separation efficiency from the waste oil liquid by a simple operation. Provide a playback method. Moreover, this invention provides the cutting oil composition for fixed abrasive wire saws which is provided for implementation of the said processing method and the reproduction | regeneration method.

The processing method of the cutting oil composition for used fixed abrasive wire saw of the present invention,
A method for treating a cutting oil composition for a used fixed abrasive wire saw used for cutting an ingot with a fixed abrasive wire saw,
The cutting oil composition for the fixed abrasive wire saw before use is
25 to 75 weights of at least one polyether compound (component A) selected from the group consisting of a polyether compound represented by the following general formula (1) and a polyether compound represented by the following general formula (2) %When,
HLB having a hydrocarbon group having 12 to 22 carbon atoms is selected from the group consisting of a nonionic surfactant having 17.0 to 20.0 and a cationic surfactant represented by the following general formula (3) 1 to 9% by weight of at least one surfactant (component B);
Water (component C),
The cloud point of the cutting oil composition for the fixed abrasive wire saw is 30 to 80 ° C.,
Oil drainage liquid containing the used cutting oil composition for a fixed abrasive wire saw and the cutting powder of the ingot produced by cutting the ingot by the fixed abrasive wire saw using the cutting oil composition for the fixed abrasive wire saw A powder removal step of removing at least the cutting powder,
The powder removal step comprises:
The oil drainage liquid is heated to a temperature equal to or higher than the cloud point of the cutting oil composition for a fixed abrasive wire saw, and an upper layer mainly composed of the polyether compound, water and the cutting powder as main components. A first step of separating into a lower layer,
A second step of removing at least the lower layer from the drained oil separated in the first step.
[Chemical 1]
R ¹ —O— (AO) _n —R ¹ `(1)
However, in the general formula (1), R <sup>1</sup> is a hydrocarbon group which may include a hydroxyl group having 1 to 8 carbon atoms, R 1 <sup>`is</sup> a hydrogen atom or a methyl group, AO represents an oxyalkylene having 2 to 4 carbon atoms The group n is an average added mole number of AO and is a number representing 2-20.
However, in the said General formula (2), AO is a C2-C4 oxyalkylene group, m1, m2, and m3 are the average addition mole numbers of AO, respectively, and the sum total of m1, m2, and m3 is 1-20. Is a number representing
In the general formula (3), R ² is a hydrocarbon group having 12 to 22 carbon atoms, R ³ is a methyl group or a hydrocarbon group having 12 to 22 carbon atoms, and X ⁻ is a monovalent anion. is there.

The method for regenerating a cutting oil composition for a used fixed abrasive wire saw of the present invention,
A method for regenerating a cutting oil composition for a used fixed abrasive wire saw, used for cutting an ingot with a fixed abrasive wire saw,
The cutting oil composition for the fixed abrasive wire saw before use is
25 to 75 weights of at least one polyether compound (component A) selected from the group consisting of a polyether compound represented by the following general formula (1) and a polyether compound represented by the following general formula (2) %When,
HLB having a hydrocarbon group having 12 to 22 carbon atoms is selected from the group consisting of a nonionic surfactant having 17.0 to 20.0 and a cationic surfactant represented by the following general formula (3) 1 to 9% by weight of at least one surfactant (component B);
Water (component C),
The cloud point of the cutting oil composition for the fixed abrasive wire saw is 30 to 80 ° C.,
Oil drainage liquid containing the used cutting oil composition for a fixed abrasive wire saw and the cutting powder of the ingot produced by cutting the ingot by the fixed abrasive wire saw using the cutting oil composition for the fixed abrasive wire saw Is heated to a temperature equal to or higher than the cloud point of the cutting oil composition for a fixed abrasive wire saw, and an upper layer mainly composed of the polyether compound and a lower layer mainly composed of water and the cutting powder. A first step of separating;
A second step of removing at least the lower layer from the waste oil separated in the first step;
At least one of the component A, the component B, and the component C is added to the residual liquid obtained by removing at least the lower layer from the drained liquid in the second step, and a fixed abrasive wire saw And a third step of obtaining the cutting oil composition.
[Chemical 4]
R ¹ —O— (AO) _n —R ¹ `(1)
However, in the general formula (1), R <sup>1</sup> is a hydrocarbon group which may include a hydroxyl group having 1 to 8 carbon atoms, R 1 <sup>`is</sup> a hydrogen atom or a methyl group, AO represents an oxyalkylene having 2 to 4 carbon atoms The group n is an average added mole number of AO and is a number representing 2-20.
However, in the said General formula (2), AO is a C2-C4 oxyalkylene group, m1, m2, and m3 are the average addition mole numbers of AO, respectively, and the sum total of m1, m2, and m3 is 1-20. Is a number representing
In the general formula (3), R ² is a hydrocarbon group having 12 to 22 carbon atoms, R ³ is a methyl group or a hydrocarbon group having 12 to 22 carbon atoms, and X ⁻ is a monovalent negative group. Ion.

  In the present invention, the cutting powder can be separated from the drained liquid with high separation efficiency by a simple operation. Therefore, when the cutting oil composition for a used fixed abrasive wire saw is discarded, the disposal process becomes easy and the used fixing is fixed. When reclaiming the cutting oil composition for an abrasive wire saw, the regeneration efficiency is high.

It is the figure which showed the mode of the sample liquid for evaluation corresponding to evaluation criteria "7", "5", "3", and "1" of Si isolation.

  In the present invention, the cutting oil composition for used fixed abrasive wire saw (hereinafter, the “cutting oil composition for fixed abrasive wire saw” may be simply referred to as “cutting oil composition”) and cutting powder are included. By heating the drainage liquid to a temperature equal to or higher than the cloud point of the cutting oil composition, the drainage liquid is divided into an upper layer mainly composed of a polyether compound and a lower layer mainly composed of water and cutting powder. By separating and removing at least the lower layer, the cutting powder is removed from the drained oil.

  In the processing method and the regeneration method of the used cutting oil composition of the present invention, the amount of the specific polyether compound contained in the lower layer is small, and the specific polyether compound and the cutting powder are favorably separated. That is, in the present invention, the cutting powder can be separated from the waste oil liquid with high separation efficiency. Moreover, in the present invention, a separation method using a cloud point is employed for separating the cutting powder and the specific polyether compound, and the cutting powder is transferred to the water layer by using a specific surfactant. Therefore, cutting powder can be separated from waste oil with high separation efficiency without using a special device such as a centrifugal separator, which is economical. Therefore, the cutting oil composition can be efficiently regenerated by reusing the residual liquid obtained by removing at least the lower layer from the drained oil and containing the specific polyether compound. In addition, when discarding the used cutting oil composition, it is possible to remove water and cutting powder in advance by removing at least the lower layer from the drained oil. For example, the above residual liquid can be easily removed by combustion treatment or the like. The waste oil can be easily disposed of.

[Cutting oil composition for fixed abrasive wire saw]
The cutting oil composition of the present invention is a cutting oil composition used for cutting an ingot with a fixed abrasive wire saw, and includes the following specific polyether compound (component A) and a specific surfactant (component B). And water (component C), and may contain abrasive grains that are out of the fixed abrasive grains, but in principle, free abrasive grains are not included.

(Component A: polyether compound)
The cutting oil composition of the present invention is a method for cleaning an ingot slice product to which a cutting oil composition is adhered, which is obtained after cutting an ingot with a fixed abrasive wire saw (hereinafter also referred to simply as “wire saw”). From the viewpoint of facilitating, improving the cutting performance of the wire saw, and improving the separation efficiency of the cutting powder, from the polyether compound represented by the following general formula (1) and the polyether compound represented by the following general formula (2) At least one polyether compound (component A) selected from the group consisting of:

[Chemical 7]
R ¹ —O— (AO) _n —R ¹ `(1)

However, in the general formula (1), R ¹ is a hydrocarbon group which may include a hydroxyl group having 1 to 8 carbon atoms, R 1 ^`is a hydrogen atom or a methyl group, AO represents an oxyalkylene having 2 to 4 carbon atoms The group n is an average added mole number of AO and is a number representing 2-20.

  When the polyether compound represented by the general formula (1) is included in the component A, the polyether compound represented by the general formula (1) may be included in the component A alone, It may be included.

The carbon number of R ¹ (hydrocarbon group) in the general formula (1) is 1 to 8 from the viewpoint of improving the cutting performance of the wire saw and facilitating cleaning of the sliced product, but from the same viewpoint. 2-8 are preferable, and 3-5 are more preferable. In addition, the number of carbon atoms of R ¹ (hydrocarbon group) in the general formula (1) is preferably 1 to 6 from the viewpoint of improving the separation efficiency of the cutting powder and reducing the foaming of the cutting oil composition, and 2 to 4 Is more preferable.

R ¹ (hydrocarbon group) may be either an aliphatic group or an aromatic group, but from the viewpoint of improving the dispersibility of Component A in water, an aliphatic group is preferred. In the aliphatic group, either a saturated or unsaturated group may be used, and either a linear or branched group may be used. Examples of R ¹ include an alkyl group, an alkenyl group, and an aryl group. Among them, from the viewpoint of improving the separation efficiency of the cutting powder and reducing the foaming of the cutting oil composition, a propyl group, an isopropyl group, a butyl group, and the like. Isobutyl group is preferable, propyl group, butyl group and isobutyl group are more preferable, and propyl group and butyl group are more preferable. R ¹ `is a hydrogen atom or a methyl group, and from the viewpoint of improving the dispersibility of Component A in water, a hydrogen atom is preferable.

  AO in the general formula (1) is an oxyalkylene group having 2 carbon atoms (oxyethylene group (EO)) and 3 carbon atoms from the viewpoint of easy control of the cloud point of the cutting oil composition. Although it is at least one selected from the group consisting of an oxyalkylene group (oxypropylene group (PO)) and an oxyalkylene group having 4 carbon atoms (oxybutylene group (BO)), from the same viewpoint, an oxypropylene group It is preferable to have only an oxypropylene group.

  N in the general formula (1) is 2 from the viewpoints of improving the separation efficiency of the cutting powder, facilitating cleaning of the sliced product, improving the fluidity of the cutting oil composition, and reducing the foaming of the cutting oil composition. It is -20, 2-16 are preferable, 2-10 are more preferable, 2-6 are more preferable, and 2-4 are more preferable.

  When the polyether compound represented by the general formula (1) includes two or more oxyalkylene groups having different carbon numbers, the arrangement of the various oxyalkylene groups may be block or random. When the arrangement of the various oxyalkylene groups is a block, the number of blocks of the various oxyalkylene groups may be 1 as long as the sum of the average added moles of the various oxyalkylene groups is within the above range. It may be more than one. When the number of blocks composed of any one of two or more oxyalkylene groups is 2 or more, the number of repeating oxyalkylene groups in each block may be the same as each other. May be different. The polyether compound represented by the general formula (1) includes both an oxyethylene group and an oxypropylene group as an oxyalkylene group from the viewpoint of improving the separation efficiency of the cutting powder, and the arrangement of the oxyethylene group and the oxypropylene group Is preferably a block. The number of oxyethylene group blocks and the number of oxypropylene group blocks may be one or two or more, respectively, as long as each average added mole number is within the above range, but one is preferable. Moreover, the polyether compound represented by the general formula (1) includes a compound containing an oxyethylene group as an oxyalkylene group and a compound containing an oxypropylene group as an oxyalkylene group from the viewpoint of improving the separation efficiency of the cutting powder. A mixture or a mixture of a compound containing only an oxyethylene group as an oxyalkylene group and a compound containing only an oxypropylene group as an oxyalkylene group is preferred.

  The polyether compound represented by the general formula (1) can be obtained, for example, by adding an alkylene oxide compound to a monohydric alcohol or phenol using an alkali such as potassium hydroxide as a catalyst.

  In the general formula (2), AO is an oxyalkylene group having 2 to 4 carbon atoms, m1, m2 and m3 are each the average number of added moles of AO, and the sum of m1, m2 and m3 (m1 + m2 + m3) is 1 to It is a number representing 20. When the polyether compound represented by the general formula (2) is contained in the component A, the polyether compound represented by the general formula (2) may be contained only one kind in the component A. It may be included.

  AO in the general formula (2) is an oxyalkylene group having 2 carbon atoms (oxyethylene group) and an oxyalkylene group having 3 carbon atoms (oxypropylene group) from the viewpoint of easy control of the cloud point. And at least one selected from the group consisting of oxyalkylene groups having 4 carbon atoms (oxybutylene groups), oxypropylene groups are preferred from the viewpoint of improving the separation efficiency of the cutting powder.

  The total of m1, m2, and m3 in the general formula (2) is 1 to 20 from the viewpoint of improving the separation efficiency of the cutting powder, but 1 to 18 is preferable, 1 to 12 is more preferable, and 1 to 10 is preferable. Is more preferable, and 1-4 are still more preferable. The polyether compound represented by the general formula (2) may contain two or more oxyalkylene groups having different carbon numbers.

  The oxyalkylene group having an average added mole number of m1, an oxyalkylene group having an average added mole number of m2, and an oxyalkylene group having an average added mole number of m3 contained in the polyether compound represented by the general formula (2) are as follows: May be the same or different. An oxyalkylene group having an average addition mole number of m1, an oxyalkylene group having an average addition mole number of m2, and an oxyalkylene group having an average addition mole number of m3 contained in the polyether compound represented by the general formula (2). When at least one includes two or more oxyalkylene groups having different carbon numbers, the arrangement of various oxyalkylene groups may be block or random, and any one oxyalkylene group of two or more oxyalkylene groups When the number of blocks consisting of is 2 or more, the number of repeating oxyalkylene groups in each block may be the same or different.

  The polyether compound represented by the general formula (2) can be obtained, for example, by adding an alkylene oxide compound to a trivalent alcohol such as glycerin using an alkali such as potassium hydroxide as a catalyst.

  The content of the polyether compound (component A) in the cutting oil composition is the viewpoint of improving the separation efficiency of the cutting powder, improving the recovery rate of the polyether compound, facilitating cleaning of the sliced product, and improving the cutting performance of the wire saw. From 25 to 75% by weight, preferably from 30 to 70% by weight, more preferably from 40 to 70% by weight, still more preferably from 40 to 60% by weight, and even more preferably from 40 to 56% by weight.

(Component B: Surfactant)
The cutting oil composition of the present invention is a viewpoint of facilitating cleaning of an ingot slice product to which a cutting oil composition obtained after cutting an ingot with a wire saw is attached, improving the cutting performance of the wire saw, and improving the separation efficiency of the cutting powder. To a nonionic surfactant having a hydrocarbon group having 12 to 22 carbon atoms and an HLB of 17.0 to 20.0, and a cationic surfactant represented by the following general formula (3) At least one surfactant (component B) selected from

However, in General Formula (3), R ² is a hydrocarbon group having 12 to 22 carbon atoms, R ³ is a methyl group or a hydrocarbon group having 12 to 22 carbon atoms, and X ⁻ is a monovalent anion. is there.

  In this specification, the HLB value of a nonionic surfactant means what was computed from the formula of HLB value = 20x (weight% of hydrophilic group) by the Griffin method. From the viewpoints of facilitating cleaning of ingot slices to which the cutting oil composition obtained after cutting the ingot is attached, improving the saw performance of the wire saw, and improving the separation efficiency of the cutting powder, the HLB is 17.0-20. 0, more preferably 17.5 to 20.0, more preferably 18.0 to 20.0, even more preferably 18.2 to 19.5, and even more preferably 19.0 to 19.5.

  Nonionic surfactants include compounds obtained by adding alkylene oxide to alcohols having 12 to 22 carbon atoms, esters of these compounds, and hydrocarbon groups having 12 to 22 carbon atoms at one end of polyalkylene glycol. And a compound in which a hydrocarbon group having 12 to 22 carbon atoms is ether-bonded to both terminals of the polyalkylene glycol. The hydrocarbon group having 12 to 22 carbon atoms may include an unsaturated group.

  Examples of the hydrocarbon group having 12 to 22 carbon atoms of the nonionic surfactant include easy cleaning of the ingot slice product to which the cutting oil composition obtained after cutting the ingot is attached, improvement of the cutting performance of the wire saw, and From the viewpoint of improving the separation efficiency of the cutting powder, examples include an alkyl group, an alkenyl group, and an aryl group. The carbon number is preferably 16 to 22, and more preferably 16 to 20. Specific examples of the hydrocarbon group include a lauryl group (n-dodecyl group), an isododecyl group, a myristyl group, a palmityl group, a stearyl group, an oleyl group, and a styrenated phenol group, and a palmityl group, a stearyl group, and an oleyl group. Group is preferable, stearyl group and oleyl group are more preferable, and stearyl group is more preferable. The nonionic surfactant may have two or more of these groups, but it is preferable to have only one of them from the viewpoint of improving the separation efficiency.

  The alkylene glycol used for the synthesis of the nonionic surfactant includes an oxyalkylene group having 2 carbon atoms (oxyethylene group), an oxyalkylene group having 3 carbon atoms (oxypropylene group), or 4 carbon atoms. Those having an oxyalkylene group (oxybutylene group) are preferred, and an oxyethylene group is preferred from the viewpoint of improving the separation efficiency of the cutting powder. When component B contains a nonionic surfactant having a hydrocarbon group having 12 to 22 carbon atoms and an HLB of 17.0 to 20.0, the nonionic surfactant is added to component B in 1 Only seeds may be included, but multiple types may be included.

The cationic surfactant represented by the general formula (3) is a quaternary salt type cationic surfactant, and 1 or 2 of a carbon hydrogen group having 12 to 22 carbon atoms in the molecular structure. It is a compound having a number. The hydrocarbon group is preferably a saturated or unsaturated linear or branched alkyl group. R ² is a hydrocarbon group, and from the viewpoint of improving the separation efficiency of the cutting powder, the carbon number thereof is 12 to 22, preferably 12 to 20, more preferably 14 to 18, and still more preferably 16 to 18. R ³ is a methyl group or a hydrocarbon group having 12 to 22 carbon atoms, preferably a methyl group or a hydrocarbon group having 12 to 20 carbon atoms, from the viewpoint of improving the separation efficiency of the cutting powder. A hydrocarbon group having 14 to 18 carbon atoms is more preferable, a methyl group or a hydrocarbon group having 16 to 18 carbon atoms is further preferable, and a methyl group is further more preferable.

  Examples of the cationic surfactant represented by the general formula (3) include alkyl (carbon number 12 to 20) trimethylammonium salt, dialkyl (carbon number 12 to 20) dimethylammonium salt, and the like. Ammonium salt, myristyl trimethyl ammonium salt, palmityl trimethyl ammonium salt, stearyl trimethyl ammonium salt, oleyl trimethyl ammonium salt, tallow trimethyl ammonium salt, hydrogenated tallow trimethyl ammonium salt, dilauryl dimethyl ammonium salt, dimyristyl dimethyl ammonium salt, dipal Examples include mytyl dimethyl ammonium salt, distearyl dimethyl ammonium salt, palmityl stearyl dimethyl ammonium salt and the like, and two or more of these may be used in combination. Among these, palmitic trimethyl ammonium salt and stearyl trimethyl ammonium salt are preferable from the viewpoint of improving the separation efficiency of the cutting powder.

X ⁻ is a monovalent anion, and examples thereof include halogen ions such as chlorine ion, bromine ion and iodine ion. Among these, chlorine ion and bromine ion are preferable.

  The content of the surfactant (component B) in the cutting oil composition improves cutting powder separation efficiency, improves the recovery rate of the polyether compound, facilitates cleaning of sliced products, and improves cutting performance of the wire saw. From the viewpoint, it is 1 to 9% by weight, but from the same viewpoint, it is preferably 1 to 7% by weight, more preferably 2 to 7% by weight, further preferably 4 to 7% by weight, and more preferably 4 to 6% by weight. Further preferred. In addition, the content of the surfactant (component B) is preferably 3 to 7% by weight, more preferably 3 to 6% by weight from the viewpoint of improving operability due to generation of bubbles during cutting.

  The weight ratio (component A / component B) of the content of the polyether compound (component A) and the surfactant (component B) in the cutting oil composition is preferably 6 to 60 from the viewpoint of improving the separation efficiency of the cutting powder. From the same viewpoint, 7 to 30 is more preferable, and 8 to 25 is more preferable.

(Component C: water)
The cutting oil composition contains water. Since the cutting oil composition contains water, the cutting oil composition has a cloud point. Moreover, the cutting oil composition can exhibit a cooling effect at the time of cutting with a wire saw.

  Although water (component C) should just be contained as a remainder except the polyether compound (component A), surfactant (component C), and the arbitrary component mentioned later of cutting oil composition, cutting oil composition The content of water (component C) in the product is preferably 74% by weight or less, more preferably 69% by weight or less, still more preferably 58% by weight or less, and 56% by weight or less from the viewpoint of improving the lubricity of the cutting oil composition. Is even more preferable. The content of water (component C) in the cutting oil composition is preferably 16% by weight or more, more preferably 23% by weight or more, and 33% by weight from the viewpoint of improving the cutting performance of the wire saw due to the cooling effect of the cutting oil composition. % Or more is more preferable, and 40% by weight or more is more preferable. Therefore, the water content in the cutting oil composition is preferably 16 to 74% by weight, more preferably 23 to 69% by weight, from the viewpoint of improving the lubricity of the cutting oil composition and improving the cutting performance of the wire saw. -58 weight% is further more preferable, 33-56 weight% is further more preferable, and 40-56 weight% is still more preferable.

  As the water contained in the cutting oil composition, for example, ultrapure water, pure water, ion exchange water, or distilled water can be used, but ultrapure water, pure water, or ion exchange water is preferable, Ultrapure water is more preferably used. Pure water and ultrapure water can be obtained, for example, by passing tap water through activated carbon, subjecting it to ion exchange treatment, and further distilling it, irradiating it with a predetermined ultraviolet germicidal lamp as necessary, or passing it through a filter. Can do. For example, the electrical conductivity at 25 ° C. is often 1 μS / cm or less for pure water and 0.1 μS / cm or less for ultrapure water.

  The cloud point of the cutting oil composition is 30 to 80 ° C, preferably 32 to 70 ° C, more preferably 35 to 65 ° C, from the viewpoint of improving the cutting performance of the wire saw and improving the separation efficiency of the cutting powder. 35-55 degreeC is further more preferable, 37-50 degreeC is further more preferable, and 40-50 degreeC is further more preferable from a viewpoint of storage stability. The cloud point of a cutting oil composition can be adjusted with each structure of a polyale compound and surfactant, and the content ratio of both.

  The cutting oil composition can optionally contain one or more compounds selected from hydrocarbon compounds, sparingly water-soluble alkyl esters, and sparingly water-soluble alkyl ketones as necessary. By containing these compounds, the lubricity of the cutting oil composition is improved.

  Examples of the hydrocarbon compound include paraffins and / or olefins having 6 to 30 carbon atoms, which are liquid at the temperature at which the wafer is cleaned, and having a saturated or unsaturated bond having a linear or branched chain, or wafers. Examples thereof include aromatic and / or aliphatic hydrocarbon compounds that are liquid at the temperature at which they are washed.

  Examples of the alkyl esters include monoesters, diesters, and triesters having 6 to 40 carbon atoms that are liquid at the temperature at which the wafer is cleaned. Among them, an ester of a higher fatty acid having 6 to 18 carbon atoms and a diol or triol having 2 to 8 carbon atoms; an ester of a higher alcohol having 1 to 18 carbon atoms and a dicarboxylic acid or tricarboxylic acid having 2 to 8 carbon atoms is preferable.

  As said alkyl ketones, a C6-C40 dialkyl ketone is preferable.

  The hydrocarbon compounds, poorly water-soluble alkyl esters and poorly water-soluble alkyl ketones may be used alone or in admixture of two or more.

  The cutting oil composition may further contain additives such as thickeners, dispersants, rust preventives, chelating agents, basic substances, and other surfactants as optional components.

  The cutting oil composition may contain a water-soluble organic compound as a medium for various components such as the polyether compound.

(Method for preparing cutting oil composition)
The method for preparing the cutting oil composition is not limited at all, and can be prepared by mixing the polyether compound (component A), the surfactant (component B) and water (component C), and further optional components. . The surfactant (component B) is preferably mixed with water in advance to form an aqueous solution from the viewpoint of improving the operability for preparing the cutting oil composition.

  The cutting oil composition can be used as a cutting oil when cutting an ingot. The ingot includes a silicon ingot for producing a silicon wafer.

(Processing method of used cutting oil composition)
The processing method of the used cutting oil composition of this invention is a processing method of the used cutting oil composition used for the cutting | disconnection of the ingot by a fixed abrasive wire saw, Comprising: The cutting oil composition of this invention was used. It includes a powder removing step of removing at least the cutting powder from the drained oil liquid containing the used cutting oil composition and the cutting powder of the ingot generated by cutting the ingot with a wire saw. The powder removal step includes a first step and a second step. In the first step, the waste oil is heated to a temperature equal to or higher than the cloud point of the cutting oil composition, and separated into an upper layer mainly composed of a polyether compound and a lower layer mainly composed of water and cutting powder. . In the second step, at least the lower layer is removed from the drained oil separated into two layers in the first step.

  Here, “mainly composed of a polyether compound” means that the content of the polyether compound in the upper layer is higher than any other component that can be contained in the upper layer, and “water and cutting powder and "The main component" means that the sum of the content of water and the content of the cutting powder in the lower layer is higher than that of any other component that can be included in the lower layer. In addition to the polyether compound (component A), the upper layer contains a surfactant (component B) that did not contribute to the transfer of the cutting powder to the aqueous layer, and is included in the above-described cutting oil composition of the present invention. Of the optional components, components that are hardly soluble in water may be further included, but water and cutting powder are hardly included, and at least cutting powder is preferably not included. On the other hand, the lower layer contains, in addition to water (component C) and cutting powder, a surfactant (component B) that has moved to the water layer together with the cutting powder, and among the optional components contained in the cutting oil composition of the present invention. A component easily soluble in water may be further contained, and a small amount of a polyether compound (component A) may be contained.

  In the processing method of the used cutting oil composition of the present invention, the removal of the cutting powder is a polyether compound (component A) that occurs when the drained oil is heated to a temperature higher than the cloud point of the cutting oil composition of the present invention. ) And water are used to separate the cutting powder from the drained oil with a simple operation and high separation efficiency. Since the cutting powder generated at the time of cutting the ingot by the fixed abrasive wire saw is dispersed in the used cutting oil composition containing the polyether compound (component A), the surfactant (component B) and water (component C), As it is, the separation efficiency of the cutting powder is poor. However, when the mixed liquid is separated into an upper layer that is an oil layer and a lower layer that is an aqueous layer by utilizing the cloud point phenomenon, the cutting powder is contained in the lower layer. Can be removed from the waste oil. Therefore, in the processing method of the used cutting oil composition of this invention, the disposal process by the combustion process etc. of the residual liquid obtained by removing at least a lower layer from waste oil liquid is facilitated, for example. For the lower layer removed from the drained liquid, for example, when the cutting powder is a cutting powder of a silicon ingot, the cutting powder can be reused as a silicon raw material by evaporating water.

  The processing method of the used cutting oil composition of this invention removes the cutting powder in a used cutting oil composition after the cutting process which cut | disconnects an ingot with a fixed abrasive wire saw using a cutting oil composition. It can be applied to the ingot cutting method. The ingot can be cut by moving the cutting oil composition at a high speed while supplying the cutting oil composition to the wire saw and the cutting portion of the ingot or the entire ingot and pressing the wire saw against the ingot.

  There is no restriction | limiting in particular about the wire saw apparatus used for a cutting | disconnection of an ingot, It can carry out using a conventionally well-known apparatus. There are no particular restrictions on the wire saw. For example, diamond or SiC abrasive grains are fixed to a piano wire mainly composed of iron or an iron alloy by plating with nickel, copper or chromium, or are fixed by a resin adhesive. And the like.

  The wire saw is supplied from, for example, a wire saw supply reel, and is wound and arranged in a groove having a predetermined interval provided on the main roller. The wire saw can be moved and moved by rotating the main roller at a predetermined rotation speed, and is usually moved and moved at a high speed so as to be about 400 to 1000 m / min. The wire saw device may be a single type that performs cutting with a single wire.

  The drained oil produced by cutting the ingot contains the used cutting oil composition and the cutting powder, and is temporarily stored, for example, in a dip tank included in the wire saw device.

(Powder removal process)
The removal of the cutting powder includes a first step of separating the drained oil into an upper layer and a lower layer, and water and the cutting powder as main components from the drained oil separated into two layers in the first step. And a second step of removing the lower layer.

(First step)
In the first step, first, the drained oil is heated to a temperature higher than the cloud point of the cutting oil composition (separation operation temperature). Before heating, the water content may be adjusted by adding water to the drained oil solution in advance. After that, if the waste oil is left at the separation operation temperature or is weakly stirred, the waste oil is separated into an upper layer mainly composed of a polyether compound and a lower layer mainly composed of water and cutting powder. To do. In order to separate the waste oil, it may be kept at the separation operation temperature for 1 hour, for example. After the drained oil is separated, the state of separation is maintained even at a temperature below the separation operation temperature.

  The cloud point (° C.) of the cutting oil composition is a temperature at which the cutting oil composition starts to become cloudy when the temperature of the cutting oil composition is increased. When the temperature of the cutting oil composition rises and the movement of water molecules becomes active, the hydrogen bond between the hydrophilic group portion of the polyether compound (component A) and the water molecules in the cutting oil composition breaks, and the polyether compound Loses its solubility in water. Therefore, if the waste oil liquid containing the polyether compound (component A) is heated to a temperature equal to or higher than the cloud point of the cutting oil composition and left to stand, the polyether compound (component A) having a specific gravity smaller than that of water is water. The cutting powder which moves to the upper side and has a large specific gravity with water moves to the lower side, and the drained oil is separated into two layers.

  In the first step, from the viewpoint of improving the separation efficiency of the cutting powder, it is preferable to heat the drained oil to a temperature (separation operation temperature) 10 to 50 ° C. higher than the cloud point of the cutting oil composition, It is more preferable to heat to a temperature higher by 50 ° C, more preferable to heat to a temperature higher by 20 to 50 ° C, even more preferable to heat to a temperature higher by 30 to 50 ° C, and to a temperature higher by 40 to 50 ° C. It is even more preferable. In the first step, the specific temperature (separation operation temperature) of the heated waste oil is preferably 40 to 90 ° C, more preferably 45 to 85 ° C, and more preferably 50 to 85 ° C from the viewpoint of improving the separation efficiency of the cutting powder. 85 degreeC is further more preferable, 55-80 degreeC is further more preferable, 60-80 degreeC is further more preferable, and 70-80 degreeC is further more preferable. Moreover, it is preferable to heat a waste oil liquid to the temperature (separation operation temperature) 10-40 degreeC higher than the cloud point of a cutting oil composition from a viewpoint of suppressing the energy to be used, and a temperature 10-30 degreeC higher. It is more preferable to heat to a temperature of 12 to 20 ° C. From the viewpoint of suppressing the energy to be used, the specific temperature (separation operation temperature) of the heated oil drainage liquid is preferably 40 to 80 ° C, more preferably 45 to 80 ° C, and further preferably 45 to 65 ° C.

  In the first step, from the viewpoint of improving the cutting powder separation efficiency, it is preferable that the drained oil is stirred before and / or during heating.

(Second step)
In the second step, at least the lower layer mainly composed of water and cutting powder is removed from the drained oil separated into two layers in the first step. When the upper layer is recycled, in the second step, not only the lower layer but also a part of the upper layer adjacent to the lower layer is preferably removed from the drained oil from the viewpoint of improving the quality of the regenerated cutting oil composition. The lower layer (mixed solution containing water and cutting powder as main components) removed from the drained oil can be further separated by centrifugation to separate the water and the precipitated layer of cutting powder. When performing this centrifugation, it is also possible to remove only the precipitated layer of the cutting powder. Centrifugal force G (gravity acceleration) in the case of centrifugal separation does not require high centrifugal force because cutting powder settles relatively easily, and is preferably 1000 to 5000 G, and preferably 1000 to 4000 G from the viewpoint of operability of centrifugation. Is more preferable, and 1000 to 3000G is more preferable.

(Reuse of remaining liquid)
The method for regenerating a used cutting oil composition for a fixed abrasive wire saw of the present invention is a method for regenerating the cutting oil composition of the present invention used for cutting an ingot with a fixed abrasive wire saw.

  The concentration of the polyether compound (component A) in the residual liquid obtained by removing at least the lower layer from the drained oil separated into the upper layer and the lower layer by the processing method of the cutting oil composition of the present invention is 25 to 25. If the concentration of the surfactant (component B) is 1 to 9 wt% and water (component C) is contained in the residual liquid, the residual liquid is used as an ingot as a cutting oil composition. It may be reused for cutting. When the concentration of one or both of the polyether compound (component A) and the surfactant (component B) in the residual liquid is a concentration outside the above predetermined concentration range, the polyether compound (component A), the surface activity At least one component selected from the group consisting of an agent (component B) and water (component C) is added to the remaining liquid, and the concentration of the polyether compound (component A) is 25 to 75% by weight; The concentration of the activator (component B) is 1 to 9% by weight, and the cutting oil composition according to the present invention containing water can be obtained and used for cutting an ingot. Moreover, when water (component C) is not contained in the residual liquid, at least water is added to the residual liquid, and the concentration of the polyether compound (component A) is 25 to 75% by weight. The cutting oil composition according to the present invention having a concentration of component B) of 1 to 9% by weight and containing water can be used for cutting an ingot.

  The amount of addition of at least one component selected from the group consisting of a polyether compound (component A), a surfactant (component B), and water (component C) to the residual liquid is the polyether in the residual liquid. It is preferable that the content of the compound (component A), the content of the surfactant (component B) and the water (component C), and the like are measured and determined based on the measurement result. Alternatively, a cutting step of cutting an ingot with a fixed abrasive wire saw using a cutting oil composition and a reduction amount of a polyether compound (component A) accompanying the powder removal step, a reduction amount of a surfactant (component B), And a decrease amount of water (component C) is estimated in advance, and selected from the group consisting of a polyether compound (component A), a surfactant (component B), and water (component C) in the same amount as the decrease amount. At least one component may be replenished to the drained oil or residual liquid obtained by forming one slice product or a plurality of slice products. For the measurement of the content of Component A, Component B, and Component C, for example, titration, NMR measurement, liquid chromatography or the like can be used.

  The present invention further discloses the following <1> to <30>.

<1>
A method for treating a cutting oil composition for a used fixed abrasive wire saw used for cutting an ingot with a fixed abrasive wire saw,
The cutting oil composition for the fixed abrasive wire saw before use is
25 to 75 weights of at least one polyether compound (component A) selected from the group consisting of a polyether compound represented by the following general formula (1) and a polyether compound represented by the following general formula (2) %When,
HLB having a hydrocarbon group having 12 to 22 carbon atoms is selected from the group consisting of a nonionic surfactant having 17.0 to 20.0 and a cationic surfactant represented by the following general formula (3) 1 to 9% by weight of at least one surfactant (component B);
Water (component C),
The cloud point of the cutting oil composition for the fixed abrasive wire saw is 30 to 80 ° C.,
Oil drainage liquid containing the used cutting oil composition for a fixed abrasive wire saw and the cutting powder of the ingot produced by cutting the ingot by the fixed abrasive wire saw using the cutting oil composition for the fixed abrasive wire saw A powder removal step of removing at least the cutting powder,
The powder removal step comprises:
The oil drainage liquid is heated to a temperature equal to or higher than the cloud point of the cutting oil composition for a fixed abrasive wire saw, and an upper layer mainly composed of the polyether compound, water and the cutting powder as main components. A first step of separating into a lower layer,
And a second step of removing at least the lower layer from the waste oil separated in the first step. A method for treating a cutting oil composition for a used fixed abrasive wire saw.
[Chemical Formula 10]
R ¹ —O— (AO) _n —R ^{1 ′} (1)
However, in the general formula (1), R ¹ is a hydrocarbon group which may include a hydroxyl group having 1 to 8 carbon atoms, R 1 ^'is a hydrogen atom or a methyl group, AO represents an oxyalkylene having 2 to 4 carbon atoms The group n is an average added mole number of AO and is a number representing 2-20.

However, in the said General formula (2), AO is a C2-C4 oxyalkylene group, m1, m2, and m3 are the average addition mole numbers of AO, respectively, and the sum total of m1, m2, and m3 is 1-20. Is a number representing
In the general formula (3), R ² is a hydrocarbon group having 12 to 22 carbon atoms, R ³ is a methyl group or a hydrocarbon group having 12 to 22 carbon atoms, and X ⁻ is a monovalent anion. It is.
<2>
The processing method of the cutting oil composition for used fixed abrasive wire saws according to <1>, wherein the ingot is a silicon ingot.
<3>
The processing method of the cutting oil composition for used fixed abrasive wire saws according to <1> or <2>, wherein in the first step, the waste oil is heated to 40 to 90 ° C.
<4>
The said 1st process WHEREIN: The said waste oil liquid is heated to the temperature 10-50 degreeC higher than the cloud point of the said cutting oil composition for fixed abrasive wire saws, In any one of said <1>-<3>. Of the cutting oil composition for used fixed abrasive wire saws.
<5>
Cutting for used fixed abrasive wire saw according to any one of <1> to <4>, wherein the content of component C is 16 to 74% by weight in the cutting oil composition for fixed abrasive wire saw. A method for treating an oil composition.
<6>
The cutting oil composition for used fixed abrasive wire saws according to any one of <1> to <5>, wherein the component B is a nonionic surfactant having an HLB of 18.2 to 19.5. Processing method.
<7>
The cutting oil composition for used fixed abrasive wire saws according to any one of <1> to <5>, wherein the component B is a nonionic surfactant having an HLB of 19.0 to 19.5. Processing method.
<8>
The component B is a nonion having at least one hydrocarbon group selected from the group consisting of lauryl group (n-dodecyl group), isododecyl group, myristyl group, palmityl group, stearyl group, oleyl group and styrenated phenol group. The processing method of the cutting oil composition for used fixed abrasive wire saws in any one of said <1>-<7> which is an ionic surfactant.
<9>
The used fixed abrasive wire saw according to any one of <1> to <5>, wherein the component B is one or more cationic surfactants selected from palmityl trimethyl ammonium salt and stearyl trimethyl ammonium salt Processing method of cutting oil composition.
<10>
The processing method of the cutting oil composition for used fixed abrasive wire saws in any one of said <1>-<9> whose content of the said component B is 4 to 7 weight%.
<11>
The processing method of the cutting oil composition for used fixed abrasive wire saws in any one of said <1>-<9> whose content of the said component B is 4 to 6 weight%.
<12>
The processing method of the cutting oil composition for used fixed abrasive wire saws in any one of said <1>-<11> in which AO of the general formula (1) of the said component A has an oxypropylene group.
<13>
The treatment of the cutting oil composition for used fixed abrasive wire saws according to any one of <1> to <12>, wherein the carbon number of R ^{1 in} the general formula (1) of the component A is 3 to 5. Method.
<14>
The treatment of the cutting oil composition for used fixed abrasive wire saws according to any one of <1> to <12>, wherein the carbon number of R ^{1 in} the general formula (1) of the component A is 2 to 4. Method.
<15>
The processing method of the cutting oil composition for used fixed abrasive wire saws according to any one of <1> to <14>, wherein R ¹ `in the general formula (1) of the component A is a hydrogen atom.
<16>
The processing method of the used cutting oil composition for fixed abrasive wire saws in any one of said <1>-<15> whose n of the general formula (1) of the said component A is 2-16.
<17>
The processing method of the used cutting oil composition for fixed abrasive wire saws in any one of said <1>-<15> whose n of the general formula (1) of the said component A is 2-6.
<18>
The processing method of the cutting oil composition for used fixed abrasive wire saws in any one of said <1>-<11> whose AO of the general formula (2) of the said component A is an oxypropylene group.
<19>
The cutting oil composition for used fixed abrasive wire saws according to any one of <1> to <18>, wherein the sum of m1, m2, and m3 of the general formula (2) of component A is 1 to 12. Processing method.
<20>
The processing method of the cutting oil composition for used fixed abrasive wire saws in any one of said <1>-<19> whose content of the said component A is 40 to 70 weight%.
<21>
The processing method of the cutting oil composition for used fixed abrasive wire saws in any one of said <1>-<20> whose content of the said component C is 16 to 74 weight%.
<22>
The processing method of the cutting oil composition for used fixed abrasive wire saws in any one of said <1>-<20> whose content of the said component C is 23 to 58 weight%.
<23>
The processing method of the used cutting oil composition for fixed abrasive wire saws in any one of said <1>-<22> whose clouding point of the said cutting oil composition for fixed abrasive wire saws is 35-65 degreeC.
<24>
In the first step, the used oil according to any one of <1> to <23>, wherein the drained oil is heated to a temperature 10 to 50 ° C. higher than the cloud point of the cutting oil composition for a fixed abrasive wire saw. The processing method of the cutting oil composition for fixed abrasive wire saws.
<25>
In the first step, the used oil according to any one of <1> to <23>, wherein the oil discharge liquid is heated to a temperature 20 to 50 ° C. higher than a cloud point of the cutting oil composition for a fixed abrasive wire saw. The processing method of the cutting oil composition for fixed abrasive wire saws.
<26>
The processing method of the cutting oil composition for used fixed abrasive wire saws according to any one of <1> to <25>, wherein in the second step, the lower layer removed from the waste oil is centrifuged. .
<27>
Further, at least one component of the component A, the component B, and the component C is added to the residual liquid obtained by removing at least the lower layer from the drained oil in the second step, and fixed grinding is performed. A method for treating a used cutting oil composition for a fixed abrasive wire saw according to any one of <1> to <26>, comprising a third step of obtaining a cutting oil composition for a grain wire saw.
<28>
In the third step, the addition amount of at least one component selected from the group consisting of Component A, Component B, and Component C to the residual liquid is the content of Component A in the residual liquid, Component B, and The processing method of the cutting oil composition for used fixed abrasive wire saws according to <27>, wherein the content of component C is measured and determined based on the measurement result.
<29>
In the third step, a cutting step of cutting an ingot with a fixed abrasive wire saw using a cutting oil composition for a fixed abrasive wire saw, and a reduction amount of component A, a reduction amount of component B, and the powder removal step, and <27> wherein the amount of decrease in component C is estimated in advance, and at least one component selected from the group consisting of component A, component B, and component C is supplied to the waste oil or residual liquid. The processing method of the cutting oil composition for used fixed-abrasive wire saws described in 1.
<30>
A method for regenerating a cutting oil composition for a used fixed abrasive wire saw, used for cutting an ingot with a fixed abrasive wire saw,
The cutting oil composition for the fixed abrasive wire saw before use is
25 to 75 weights of at least one polyether compound (component A) selected from the group consisting of a polyether compound represented by the following general formula (1) and a polyether compound represented by the following general formula (2) %When,
HLB having a hydrocarbon group having 12 to 22 carbon atoms is selected from the group consisting of a nonionic surfactant having 17.0 to 20.0 and a cationic surfactant represented by the following general formula (3) 1 to 9% by weight of at least one surfactant (component B);
Water (component C),
The cloud point of the cutting oil composition for the fixed abrasive wire saw is 30 to 80 ° C.,
Oil drainage liquid containing the used cutting oil composition for a fixed abrasive wire saw and the cutting powder of the ingot produced by cutting the ingot by the fixed abrasive wire saw using the cutting oil composition for the fixed abrasive wire saw Is heated to a temperature equal to or higher than the cloud point of the cutting oil composition for a fixed abrasive wire saw, and an upper layer mainly composed of the polyether compound and a lower layer mainly composed of water and the cutting powder. A first step of separating;
A second step of removing at least the lower layer from the waste oil separated in the first step;
At least one of the component A, the component B, and the component C is added to the residual liquid obtained by removing at least the lower layer from the drained liquid in the second step, and a fixed abrasive wire saw A method for regenerating a used cutting oil composition for a fixed abrasive wire saw, comprising a third step of obtaining a cutting oil composition for use.
[Chemical 13]
R ¹ —O— (AO) _n —R ^{1 ′} (1)
However, in the general formula (1), R ¹ is a hydrocarbon group which may include a hydroxyl group having 1 to 8 carbon atoms, R 1 ^'is a hydrogen atom or a methyl group, AO represents an oxyalkylene having 2 to 4 carbon atoms The group n is an average added mole number of AO and is a number representing 2-20.
However, in the said General formula (2), AO is a C2-C4 oxyalkylene group, m1, m2, and m3 are the average addition mole numbers of AO, respectively, and the sum total of m1, m2, and m3 is 1-20. Is a number representing
In the general formula (3), R ² is a hydrocarbon group having 12 to 22 carbon atoms, R ³ is a methyl group or a hydrocarbon group having 12 to 22 carbon atoms, and X ⁻ is a monovalent negative group. Ion.

(Preparation of cutting oil composition)
The cutting oil compositions of Examples 1 to 22 and Comparative Examples 1 to 13 were obtained by blending and mixing the components so as to have the compositions (% by weight) described in Tables 1 and 2. Specifically, water was added to a commercially available surfactant or an aqueous solution thereof to adjust the amount of the surfactant and water, and then they were mixed with a polyether compound to obtain a cutting oil composition.

(Measurement of cloud point)
(1) Put 50 mL of the cutting oil composition described in Tables 1 and 2 into a test tube having a capacity of 100 mL.
(2) The test tube is put in a water bath, and the temperature of the cutting oil composition is increased from room temperature at a rate of 2 ° C./min while manually stirring the cutting oil composition using a glass rod-shaped thermometer.
(3) The temperature of the cutting oil composition is read when the turbidity does not disappear even after stirring.
(4) Remove the test tube from the water bath and gradually lower the temperature to room temperature while stirring in an atmosphere at 25 ° C.
(5) Repeat (2) to (4) twice, and use the average value of the temperatures read in (3) as the cloud point.

(Evaluation of liquid uniformity)
(1) Put 50 mL of the cutting oil composition described in Tables 1 and 2 into a test tube having a capacity of 100 mL.
(2) The test tube was put into a thermostat adjusted to 30 ° C., and the state of the cutting oil composition was visually confirmed after 1 hour, and liquid uniformity was evaluated using the following indices.
○: Transparent x: Cloudy (3) The clouded (x) cutting oil composition has an adverse effect on machinability due to separation of oil and moisture during cutting. Therefore, the following Si separability was evaluated only about the cutting oil composition which was transparent ((circle)).

(Measurement of Si separability)
To a 50 mL plastic container, 25 g of the cutting oil composition and 5 g of Si powder (manufactured by High Purity Chemical Co., Ltd.) with a particle size of 5 μmφ were added, and then 50 g of Zr beads (particle size: 1 mmφ, manufactured by Nikkato) were added. Next, an actual solar cell using a fixed abrasive wire saw is prepared by setting a poly container on a paint shaker (PC-1773 manufactured by ASADA), vibrating for 5 hours, and pulverizing Si powder in a cutting oil composition. A sample liquid for evaluation containing Si powder close to the Si cutting powder generated at the time of cutting the Si wafer for use and a cutting oil composition was prepared as an oil drainage liquid. At this time, it was confirmed with a particle size measuring machine (Horiba, LA-920) that the particle size of the pulverized Si powder was about 1 to 1.5 μm. Next, 10 mL of the sample liquid for evaluation is sampled in a test tube with a spoid, and the temperature of the sample liquid for evaluation is raised to the separation operation temperature described in Tables 1 and 2 with a warm bath. And kept at that temperature for 1 hour. Although the separation operation temperature is the temperature of the sample liquid for evaluation, it can be identified with the temperature of the warm bath, so the temperature of the warm bath was measured as the separation operation temperature. The Si separability observed from the sample solution for evaluation after being left for 1 hour was evaluated using the following indicators. FIG. 1 shows an example in which the Si separability is 7, 5, 3 and 1.

[Evaluation criteria for Si separability]
7: The boundary between the upper layer and the lower layer is 5.5 mL or less of the scale of the test tube 6: The boundary between the upper layer and the lower layer is more than 5.5 to 6.5 mL of the scale of the test tube
5: The boundary between the upper layer and the lower layer is more than 6.5 to 7.5 mL of the scale of the test tube
4: The boundary between the upper layer and the lower layer is more than 7.5 to 8.5 mL of the scale of the test tube
3: The boundary between the upper layer and the lower layer is more than 8.5 to 9.5 mL of the scale of the test tube
2: The boundary between the upper layer and the lower layer is more than 9.5 mL of the scale of the test tube 1: The boundary between the upper layer and the lower layer is not bounded by the scale of the test tube (the boundary between the upper layer and the lower layer cannot be confirmed) or is unclear 7 is the best. The better the Si separability, the smaller the amount of polyether compound contained in the lower layer. The upper layer is composed mainly of a polyether compound, and the lower layer is composed mainly of water and Si powder. Therefore, the better the Si separation, the larger the amount of the upper layer, and at least the lower layer is removed from the separated drained oil. It can be said that the reusability of the residual liquid obtained in this way is good.

  As shown in Table 1, the waste oil liquid containing the cutting oil compositions and cutting powders of Examples 1 to 22 was heated to a temperature equal to or higher than the cloud point of the cutting oil composition, and separated into an upper layer and a lower layer. Then, the cutting powder can be removed from the drained oil with high efficiency by removing the lower layer. In addition, when the waste oil is separated into the upper layer and the lower layer using the cloud point phenomenon, the cutting powder and the polyether compound are separated well, and as a result, the lower layer is removed from the waste oil. A composition containing a polyether compound can be recovered in a recovery rate.

  Furthermore, with respect to the sample liquid for evaluation containing the cutting oil compositions of Example 1, Comparative Examples 1, 2, and 6, attempts were made to improve Si separability by the following method. Specifically, the test tube after evaluating the Si separability was set in a centrifuge (CN-1040 manufactured by iuchi) and treated at 4000 rpm for 15 minutes (1500 G) to try to improve the Si separability. It was. Based on the above [Evaluation criteria for Si separability], the Si separability before and after centrifugation was compared.

  In Example 1 where the Si separability was “4”, the Si separability became “7” by centrifugation, which was significantly improved. However, in Comparative Examples 1, 2 and 6 where the Si separability was “1” or “2”, Even after centrifugation, the Si separability was “1”, “2”, and “2”, respectively, and the separability was hardly improved.

The detail of each component in Table 1 and Table 2 is as follows. Number 1 below. -10. Corresponds to the numbers of the polyether compounds in Table 1 and Table 2, and the numerical values in the brackets indicate the weight% of each component in the cutting agent composition.
Polyether compounds Difluoroethylene glycol monofluoroether / iso-butyl alcohol [25/25]
(Difluoropolyethylene monofluoroether: R ¹ has 3 carbon atoms, AO = PO, n = 2, Nihon Emulsifier Co., Ltd./iso-butyl diglycol: R ¹ has 4 carbon atoms, AO = EO, n = 2 Manufactured by Nippon Emulsifier Co., Ltd.)
2. C ₄ O (EO) ₅ (PO) ₄ H [50]
(R ¹ has 4 carbon atoms (butyl group), AO = EO and PO (block arrangement), n = 9, produced according to the following production example)
3. Diethylene glycol [50]
(The carbon number of R ¹ is 0, AO = EO, n = 2, manufactured by Wako Pure Chemical Industries, Ltd.)
4). Hexyl glycol / diethylene glycol [25/25]
(Hexylglycol: R ¹ has 6 carbon atoms, AO = EO, n = 2, manufactured by Nippon Emulsifier Co., Ltd./Diethylene glycol: R ¹ has 0 carbon atoms, AO = EO, n = 2, manufactured by Wako Pure Chemical Industries, Ltd.)
5. Hexyl glycol / diethylene glycol [15/35]
(Hexylglycol: R ¹ has 6 carbon atoms, AO = EO, n = 2, manufactured by Nippon Emulsifier Co., Ltd./Diethylene glycol: R ¹ has 0 carbon atoms, AO = EO, n = 2, manufactured by Wako Pure Chemical Industries, Ltd.)
6). Glycerin PO ₁ / Glycerin PO ₁₂ / Hexylglycol [18.5 / 18.5 / 10.0]
(Glycerin PO ₁ : AO = PO, m1 + m2 + m3 = 1, manufactured according to the following production example / glycerin PO ₁₂ : AO = PO, m1 + m2 + m3 = 12, manufactured according to the following manufacturing example / hexyl alcohol recall: R ¹ has 6 carbon atoms, AO = EO, n = 2, manufactured by Nippon Emulsifier Co., Ltd.)
7). Glycerin PO ₁ / Glycerin PO ₁₂ / Difluoroethylene glycol methyl ether [18.5 / 18.5 / 10.0]
(Glycerin PO ₁ : AO = PO, m1 + m2 + m3 = 1, produced according to the following production example / glycerin PO ₁₂ : AO = PO, m1 + m2 + m3 = 12, produced according to the following production example / difluoroethylene glycol dimethyl ether: R ¹ has 1 carbon atom, AO = PO, R ¹ `is a methyl group, n = 2, manufactured by Nippon Emulsifier Co., Ltd.)
8). Glycerin PO ₁₀ [50]
(AO = PO, m1 + m2 + m3 = 10, manufactured according to the following manufacturing example)
9. C ₄ O (EO) ₉ (PO) ₇ H [70]
(R ¹ carbon number 4 (butyl group), AO = EO and PO (block arrangement), n = 16, produced according to the following production example)
10. C ₄ O (EO) ₉ (PO) ₇ H [30]
(R ¹ carbon number 4 (butyl group), AO = EO and PO (block arrangement), n = 16, produced according to the following production example)

[Production Example of Polyether Compound]
(1) Production Example of C ₄ O (EO) ₅ (PO) ₄ H The polyether compound having the number “2” described in Table 1 was prepared by the following method. The weight average molecular weight was 526 as measured by the following method.

  The method for producing the polyether compound having the number “2” is as follows. An autoclave was charged with 74.1 g (1 mol) of n-butanol and 0.30 g (0.4 wt%) of KOH (catalyst), the air in the autoclave was replaced with nitrogen, and the temperature in the autoclave was stirred while butanol was being stirred. The temperature was raised to 130 ° C. After introducing 220 g (5 mol) of ethylene oxide into the autoclave at a pressure (gauge pressure) of 3.5 kg / cm @ 2, the n-butanol and ethylene oxide were reacted until the pressure decreased and became constant, then the autoclave. The temperature inside was lowered to 120 ° C. Next, 232 g (4 mol) of propylene oxide was introduced into the autoclave at a pressure (gauge pressure) of 3.5 kg / cm 2. After the butanol and propylene oxide were reacted until the pressure decreased and became constant, the temperature in the autoclave was lowered to room temperature to obtain about 520 g of the polyether compound having the number “2”.

The weight average molecular weight of the polyether compound of number “2” is a value calculated based on a peak in a chromatogram obtained by applying a gel permeation chromatography (GPC) method under the following conditions.
Column: G4000PWXL + G2500PWXL (manufactured by Tosoh)
Eluent: (0.2M phosphate buffer) / (CH3CN) = 9/1 (volume ratio)
Flow rate: 1.0 mL / min
Column temperature: 40 ° C
Detector: RI detector Standard material: Polystyrene

(2) Production Example of Glycerin PO _{1 In} an autoclave, 92.1 g of glycerin and 1.4 g (1.5 wt%) of KOH were charged and dehydrated at 110 ° C. and 1.3 kPa for 30 minutes. After dehydration, the air in the autoclave was replaced with nitrogen, the temperature in the autoclave was raised to 130 ° C., and then 58.1 g of propylene oxide was charged. After addition reaction and aging at 130 ° C., the mixture was cooled to 80 ° C., and unreacted propylene oxide in the autoclave was removed at 4.0 kPa for 30 minutes. After removing unreacted propylene oxide, 3.0 g of acetic acid was added to the autoclave and kept at 80 ° C. for 30 minutes, followed by extraction to obtain a PO adduct of glycerin having an average addition mole number of 1 mol.

(3) Production example of glycerin PO ₁₂ PO addition of glycerin with an average addition mole number of 1 mol except that the charge amount of KOH was changed to 2.8 g (3% by weight) and the charge amount of propylene oxide was changed to 660.7 g. The glycerin PO adduct having an average addition mole number of 12 mol was obtained in the same manner as the production method.

(4) Production example of glycerin PO ₁₀ PO addition of glycerin having an average addition mole number of 1 mol, except that the amount of KOH charged was changed to 2.8 g (3% by weight) and the amount of propylene oxide charged was changed to 580.1 g. The glycerin PO adduct having an average addition mole number of 10 mol was obtained in the same manner as in the production method.

(5) Production example of C ₄ O (EO) ₉ (PO) ₇ H C ₄ O (EO) ₅ (PO) ₄ except that the amount of ethylene oxide charged was changed to 396 g and the amount of propylene oxide charged to 406 g. In the same manner as in H, about 870 g of a polyether compound having an average addition mole number of EO of 9 moles and an average addition mole number of PO of 7 moles was obtained. It was 876 when the weight average molecular weight was measured by the said method.

Details of the surfactants described in Tables 1 and 2 are as follows.
1. Emulgen 130K (Kao, hydrocarbon group with 12 carbon atoms (n-dodecyl group), HLB = 18.1)
2. Softanol 500 (manufactured by Nippon Shokubai, hydrocarbon group with 12 carbon atoms (iso-dodecyl group), HLB = 18.3)
3. BROWNON EN-1560 (Aoki Yushi, hydrocarbon group with 18 carbon atoms (oleyl group), HLB = 18.2)
4). Emanon 3119V (manufactured by Kao, hydrocarbon group with 18 carbon atoms (stearyl group), HLB = 19.4)
5. Braunon SR-750 (Aoki Oil & Fats, hydrocarbon group carbon number 18 (stearyl group), HLB = 17.8)
6). Emanon 3229RV (manufactured by Kao, hydrocarbon group with 18 carbon atoms (stearyl group), HLB = 19.2)
7). Emulgen A-500 (manufactured by Kao, hydrocarbon group with 22 carbon atoms (styrenated phenol group), HLB = 18.0)
8). Coatamine 86W (manufactured by Kao, R ² is a hydrocarbon group having 16 and 18 carbon atoms (harmityl group, stearyl group), R ³ is a methyl group, and X ⁻ is a chloride ion)
9. Coatamine 60W (Kao, R ² is a hydrocarbon group having 16 carbon atoms (harmityl group), R ³ is a methyl group, X ^- is a chloride ion)
10. Coatamine 24P (Kao, R ² is a hydrocarbon group having 12 and 14 carbon atoms (lauryl group, myristyl group), R ³ is a methyl group, X ^- is a chloride ion)
11. Coatamine D86P (Kao, R ² is a hydrocarbon group having 16 and 18 carbon atoms (harmityl group, stearyl group), R ³ is a hydrocarbon group having 16 and 18 carbon atoms (harmityl group, stearyl group), X ⁻ Is chloride ion)
12 Braunon EH-30 (Aoki Oil & Fats, hydrocarbon group with 8 carbon atoms (ethylhexyl group), HLB = 18.2)
13. Emanon 1112 (made by Kao, hydrocarbon group with 12 carbon atoms (n-dodecyl group), HLB = 13.7)
14 Softanol 150 (made by Nippon Shokubai, hydrocarbon group with 12 carbon atoms (iso-dodecyl group), HLB = 15.3)
15. Braunon EN-1520A (manufactured by Aoki Oil & Fats, hydrocarbon group with 18 carbon atoms (oleyl group), HLB = 15.4)
16. BRAUNON SR-715 (manufactured by Aoki Oil & Fats, hydrocarbon group with 18 carbon atoms (stearyl group), HLB = 13.5)

In Table 1, “(stearyl + palmityl) / methyl” means that the surfactant with the number “8” is a surfactant in which R ² is a stearyl group and R ³ is a methyl group in the general formula (3). , R ² is a palmityl group and R ³ is a mixture with a methyl group surfactant. The surfactant with the number “9” is a surfactant in which R ² is a palmityl group and R ³ is a methyl group. The surfactant with the number “10” is a mixture of a surfactant in which R ² is a lauryl group and R ³ is a methyl group, and a surfactant in which R ² is a myristyl group and R ³ is a methyl group. The surfactant with the number “11” is a mixture of a surfactant in which R ² is a stearyl group and R ³ is a palmityl group, and a surfactant in which R ² is a palmityl group and R ³ is a stearyl group.

  According to the present invention, since the cutting powder can be separated with high separation efficiency from the drained oil liquid containing the used cutting oil composition and the cutting powder by a simple operation, the regeneration efficiency of the cutting oil composition is good. Moreover, when discarding a used cutting oil composition, disposal processing becomes easy. Therefore, the present invention can contribute to improvement of wafer productivity.

Claims (15)

A method for treating a cutting oil composition for a used fixed abrasive wire saw used for cutting an ingot with a fixed abrasive wire saw,
The cutting oil composition for the fixed abrasive wire saw before use is
25 to 75 weights of at least one polyether compound (component A) selected from the group consisting of a polyether compound represented by the following general formula (1) and a polyether compound represented by the following general formula (2) %When,
HLB having a hydrocarbon group having 12 to 22 carbon atoms is selected from the group consisting of a nonionic surfactant having 17.0 to 20.0 and a cationic surfactant represented by the following general formula (3) 1 to 9% by weight of at least one surfactant (component B);
Water (component C),
The cloud point of the cutting oil composition for the fixed abrasive wire saw is 30 to 80 ° C.,
Oil drainage liquid containing the used cutting oil composition for a fixed abrasive wire saw and the cutting powder of the ingot produced by cutting the ingot by the fixed abrasive wire saw using the cutting oil composition for the fixed abrasive wire saw A powder removal step of removing at least the cutting powder,
The powder removal step comprises:
The oil drainage liquid is heated to a temperature equal to or higher than the cloud point of the cutting oil composition for a fixed abrasive wire saw, and an upper layer mainly composed of the polyether compound, water and the cutting powder as main components. A first step of separating into a lower layer,
And a second step of removing at least the lower layer from the waste oil separated in the first step. A method for treating a cutting oil composition for a used fixed abrasive wire saw.
[Chemical 1]
R ¹ —O— (AO) _n —R ^{1 ′} (1)
However, in the general formula (1), R ¹ is a hydrocarbon group which may include a hydroxyl group having 1 to 8 carbon atoms, R 1 ^'is a hydrogen atom or a methyl group, AO represents an oxyalkylene having 2 to 4 carbon atoms The group n is an average added mole number of AO and is a number representing 2-20.
However, in the said General formula (2), AO is a C2-C4 oxyalkylene group, m1, m2, and m3 are the average addition mole numbers of AO, respectively, and the sum total of m1, m2, and m3 is 1-20. Is a number representing
In the general formula (3), R ² is a hydrocarbon group having 12 to 22 carbon atoms, R ³ is a methyl group or a hydrocarbon group having 12 to 22 carbon atoms, and X ⁻ is a monovalent anion. It is.   The processing method of the cutting oil composition for used fixed abrasive wire saws according to claim 1, wherein the ingot is a silicon ingot.   The processing method of the cutting oil composition for used fixed abrasive wire saws according to claim 1 or 2, wherein in the first step, the drained oil is heated to 40 to 90 ° C.   The use according to any one of claims 1 to 3, wherein in the first step, the drained oil is heated to a temperature 10 to 50 ° C higher than a cloud point of the cutting oil composition for the fixed abrasive wire saw. Of processing cutting oil composition for used fixed abrasive wire saw. The used cutting oil composition for fixed abrasive wire saws according to any one of claims 1 to 4, wherein the content of component C is 16 to 74 wt% in the cutting oil composition for fixed abrasive wire saws. How to handle things.
  The component B is a nonion having at least one hydrocarbon group selected from the group consisting of lauryl group (n-dodecyl group), isododecyl group, myristyl group, palmityl group, stearyl group, oleyl group and styrenated phenol group. The processing method of the cutting oil composition for used fixed abrasive wire saws in any one of Claims 1-5 which is an ionic surfactant.   Cutting oil composition for used fixed abrasive wire saws according to any one of claims 1 to 5, wherein said component B is one or more cationic surfactants selected from palmityl trimethyl ammonium salt and stearyl trimethyl ammonium salt. How to handle things.   The processing method of the cutting oil composition for used fixed abrasive wire saws in any one of Claims 1-7 in which AO of the general formula (1) of the said component A has an oxypropylene group.   The processing method of the cutting oil composition for used fixed abrasive wire saws in any one of Claims 1-7 whose AO of the general formula (2) of the said component A is an oxypropylene group.   The used fixed abrasive according to any one of claims 1 to 9, wherein in the first step, the drained oil is heated to a temperature 10 to 50 ° C higher than a cloud point of the cutting oil composition for the fixed abrasive wire saw. The processing method of the cutting oil composition for wire saws.   The processing method of the used cutting oil composition for fixed abrasive wire saws in any one of Claims 1-10 which performs centrifugation with respect to the lower layer removed from the said waste oil liquid in a 2nd process.   Further, at least one component of the component A, the component B, and the component C is added to the residual liquid obtained by removing at least the lower layer from the drained oil in the second step, and fixed grinding is performed. The processing method of the cutting oil composition for used fixed abrasive wire saws in any one of Claims 1-11 including the 3rd process of obtaining the cutting oil composition for grain wire saws.   In the third step, the addition amount of at least one component selected from the group consisting of Component A, Component B, and Component C to the residual liquid is the content of Component A in the residual liquid, Component B, and The processing method of the cutting oil composition for used fixed abrasive wire saws of Claim 12 which measures content of the component C and determines based on the said measurement result.   In the third step, a cutting step of cutting an ingot with a fixed abrasive wire saw using a cutting oil composition for a fixed abrasive wire saw, and a reduction amount of component A, a reduction amount of component B, and the powder removal step, and The amount of decrease in component C is estimated in advance, and at least one component selected from the group consisting of component A, component B, and component C is supplied to the drained oil or residual liquid. The processing method of the cutting oil composition for used fixed abrasive wire saw of description. A method for regenerating a cutting oil composition for a used fixed abrasive wire saw, used for cutting an ingot with a fixed abrasive wire saw,
The cutting oil composition for the fixed abrasive wire saw before use is
25 to 75 weights of at least one polyether compound (component A) selected from the group consisting of a polyether compound represented by the following general formula (1) and a polyether compound represented by the following general formula (2) %When,
HLB having a hydrocarbon group having 12 to 22 carbon atoms is selected from the group consisting of a nonionic surfactant having 17.0 to 20.0 and a cationic surfactant represented by the following general formula (3) 1 to 9% by weight of at least one surfactant (component B);
Water (component C),
The cloud point of the cutting oil composition for the fixed abrasive wire saw is 30 to 80 ° C.,
Oil drainage liquid containing the used cutting oil composition for a fixed abrasive wire saw and the cutting powder of the ingot produced by cutting the ingot by the fixed abrasive wire saw using the cutting oil composition for the fixed abrasive wire saw Is heated to a temperature equal to or higher than the cloud point of the cutting oil composition for a fixed abrasive wire saw, and an upper layer mainly composed of the polyether compound and a lower layer mainly composed of water and the cutting powder. A first step of separating;
A second step of removing at least the lower layer from the waste oil separated in the first step;
At least one of the component A, the component B, and the component C is added to the residual liquid obtained by removing at least the lower layer from the drained liquid in the second step, and a fixed abrasive wire saw A method for regenerating a used cutting oil composition for a fixed abrasive wire saw, comprising a third step of obtaining a cutting oil composition for use.
[Chemical 4]
R ¹ —O— (AO) _n —R ^{1 ′} (1)
However, in the general formula (1), R ¹ is a hydrocarbon group which may include a hydroxyl group having 1 to 8 carbon atoms, R 1 ^'is a hydrogen atom or a methyl group, AO represents an oxyalkylene having 2 to 4 carbon atoms The group n is an average added mole number of AO and is a number representing 2-20.

However, in the said General formula (2), AO is a C2-C4 oxyalkylene group, m1, m2, and m3 are the average addition mole numbers of AO, respectively, and the sum total of m1, m2, and m3 is 1-20. Is a number representing
In the general formula (3), R ² is a hydrocarbon group having 12 to 22 carbon atoms, R ³ is a methyl group or a hydrocarbon group having 12 to 22 carbon atoms, and X ⁻ is a monovalent negative group. Ion.