JP2006182901A - Water-soluble oil finish modifier for cutting and water-soluble oil finish for cutting - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water-soluble oil finish for cutting which can inhibit the reaction of an active workpiece with the oil finish component. <P>SOLUTION: The water-soluble oil finish for cutting contains an oxidizing agent. An embodiment of the oil finish is a water-soluble oil finish wherein the oxidizing agent is hydrogen peroxide. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a water-soluble oil for cutting and a modifying agent for use in a wire saw or the like for cutting a workpiece with high efficiency and high accuracy using loose abrasive grains. INDUSTRIAL APPLICABILITY The present invention is widely used in the industrial field for producing cutting fluids and the industrial field for cutting quartz, quartz, silicon, and the like, and is particularly suitable for the cutting process of silicon ingots.

  As a method for cutting crystal, quartz, and silicon, a processing method using a wire saw, a blade saw or the like using loose abrasive grains is widely used. In that case, a liquid (slurry) prepared by mixing abrasive grains and an oil agent is used. Previously, non-aqueous oils were mainly used in which abrasive grains such as alumina, silicon oxide, and diamond were dispersed in the base oil. However, in recent years, consideration has been given to safety aspects such as flammability and environmental impact. Accordingly, water-based oil agents based on water and glycol have been used frequently.

  Various studies have been made so far for making the oil for cutting processing water-based. For example, Patent Document 1 discloses an oil composition for cutting using a cationic water-soluble resin and bentonite or aqueous silica sol, and Patent Document 2 discloses bentonite, cellulose, mica, and the like based on water and a polyhydric alcohol. An oil composition for cutting processing to which is added is disclosed. Furthermore, Patent Document 3 discloses a composition in which a water-soluble ether compound and an alkylamine derivative are combined. These are all inventions whose main purpose is to improve the dispersion stability of the abrasive grains, and greatly contribute to the improvement of the performance of the aqueous slurry composition.

  However, when the object to be cut is a substance reactive to the oil component, such as a silicon ingot, it is necessary to consider the reaction between the oil component and the object to be cut. For example, silicon fine powder generated when high-purity silicon is cut and processed is dangerous because it is in an active state and reacts with moisture in the oil to generate hydrogen gas. Furthermore, silicon that reacts with water becomes silicate ions, and the viscosity of the slurry is remarkably increased, so that workability is lowered.

Although there are not many reports on the improvement of water-soluble cutting processed oils focusing on this point, in Patent Document 4 and Patent Document 5 as an example, an organic acid is blended in the oil, and the pH of the oil is neutral to acidic (8 It has been proposed to make ~ 5).
Japanese Patent Laid-Open No. 11-349979 JP 2000-327838 A JP 2001-164284 A JP 2000-160185 A JP 2002-80883 A

  However, those obtained by blending an organic acid with a specific oil agent as shown in Patent Documents 4 and 5 are still insufficient in effect for active silicon fine powder.

  Then, an object of this invention is to provide the water-soluble oil agent for cutting processes which can suppress reaction with an active workpiece and an oil agent component. In particular, an object of the present invention is to provide a water-soluble oil for cutting which suppresses the reaction between water and silicon, generates less hydrogen gas, and further prevents the slurry from thickening.

  As a result of studying various modifiers in the process leading to the present invention, the present inventors have found that water for cutting processing can be obtained even in a neutral to alkaline region by adding an oxidizing agent to the water-soluble oil for cutting processing. It has been found that hydrogen gas generation and slurry thickening can be suppressed without impairing the performance of the soluble oil (such as abrasive dispersion stability), and the present invention has been completed.

  According to the first aspect of the present invention, there is provided a water-soluble oil modifier for cutting processing characterized by containing an oxidizing agent to solve the above problems.

  According to this invention, by adding this cutting water-soluble oil modifier to a conventional cutting water-soluble oil, it is possible to easily suppress the reaction between the active workpiece and the oil component. Soluble oils can be provided.

  According to the second aspect of the present invention, a water-soluble oil agent for cutting processing characterized by containing an oxidizing agent is provided to solve the above problem.

  According to this invention, it is possible to provide a water-soluble oil agent for cutting work that can suppress the reaction between the workpiece and the oil component.

  In the first and second embodiments, the oxidizing agent is preferably hydrogen peroxide.

  Moreover, in 2nd aspect, it is preferable that content of an oxidizing agent is 0.1-10 mass% containing on the basis of the water-soluble oil agent for cutting processes.

  By making content of an oxidizing agent into such a range, reaction with an effectively active workpiece and an oil agent component can be suppressed.

  In addition, this water-soluble oil for cutting is suitably used for cutting silicon ingots. In this case, the reaction between water and silicon is suppressed, the amount of hydrogen gas generated is small, and the slurry is difficult to thicken. can do.

  By mix | blending an oxidizing agent with the water-soluble oil agent for cutting processes, reaction with the to-be-processed material and oil agent component reactive with respect to an oil agent component can be suppressed. In particular, when used for cutting silicon, the reaction between water and silicon can be suppressed, so the amount of hydrogen gas generated is small and the viscosity of the slurry changes without impairing the oil agent performance such as abrasive dispersion stability. Less water-soluble oil for cutting can be obtained. As a result, it is possible to obtain a risk reduction and work efficiency improvement effect.

  Such an operation and gain of the present invention will be made clear from the best mode for carrying out the invention described below.

  The present invention is characterized in that an oxidizing agent is contained in a water-soluble oil for cutting. The oxidizing agent may be added together with other raw material components at the time of preparation of the water-soluble oil for cutting processing, but it can be added to a commercially available water-soluble oil for cutting processing or a previously prepared water-soluble oil for cutting processing. It can also be added as. In order to prevent the deactivation of the oxidizing agent due to storage of the water-soluble oil for cutting, it is preferable to add it as a modifying agent later if necessary. At that time, the modifying agent may be the oxidizing agent itself or may be diluted with an appropriate solvent.

  As the oxidizing agent, any substance that releases oxygen in a slurry-like water-soluble oil for cutting work and exhibits an effect can be used without any particular trouble. For example, hydrogen peroxide, hypochlorous acid and its salt, ozone, persulfuric acid and its salt, permanganic acid and its salt, percarbonate and its salt, copper sulfate, iron chloride, silver nitrate and the like can be used. Of these, peroxide is preferred, and hydrogen peroxide is most preferred. If the content is too small, the effect cannot be expected. If the content is too large, corrosion is a concern. Therefore, the content is 0.1 to 10% by mass based on the total amount of the water-soluble oil for cutting.

  Regarding the water-soluble oil for cutting processing of the present invention, those having a known composition as the water-soluble oil for cutting processing can be used for components other than the above-mentioned oxidizing agent components. The basic composition of the water-soluble oil agent for cutting processing includes water as a medium and a water-soluble organic compound such as a glycol compound as essential components. If necessary, a dispersant such as a silicate, a carboxylic acid, and a base Containing chemical substances. Specific examples of the oil agent composition include those described in Japanese Patent No. 2816940, Japanese Patent No. 32966781, Japanese Patent Application Laid-Open No. 2000-160185, and Japanese Patent Application Laid-Open No. 2002-80883. Typical components, glycol compounds, silicates, carboxylic acids, and basic substances will be described below.

  As the glycol compound used in the water-soluble oil for cutting process of the present invention, those applied to known water-soluble oils for cutting process can be used without particular limitation. For example, ethylene glycol, ethylene glycol ester derivatives, ethylene glycol ether derivatives, propylene glycol, propylene glycol ester derivatives, propylene glycol ether derivatives, and the like can be used. Of these, the most preferred glycol compound is propylene glycol.

  As the silicate used in the water-soluble oil for cutting process of the present invention, those applied to the known water-soluble oil for cutting process can be used without particular limitation. Examples thereof include potassium silicate and sodium silicate. , Potassium metasilicate, sodium metasilicate, potassium orthosilicate, sodium orthosilicate and the like. Of these, the most preferred silicate is potassium silicate.

  As the carboxylic acid used in the present invention, those applied to known water-soluble oils for cutting processing can be used without particular limitation. Examples thereof include capric acid, caprylic acid, lauric acid, palmitic acid, and stearic acid. Linear fatty acids such as oleic acid and linoleic acid; branched fatty acids such as isostearic acid and isopalmitic acid; dibasic acids such as adipic acid and sebacic acid; aromatic carboxylic acids such as benzoic acid, cinnamic acid and phthalic acid; Examples thereof include hydroxycarboxylic acids such as acid, gluconic acid and malic acid. Of these, the most preferred carboxylic acid is hydroxycarboxylic acid, and citric acid is most preferred.

  The basic substance used in the present invention is mainly used as a neutralizing agent for carboxylic acid, and those applied to known water-soluble oils for cutting can be used without any particular limitation. For example, aliphatic amines such as butylamine, octylamine and oleylamine; aromatic amines such as benzylamine; polyamines such as ethylenediamine, propylenediamine, diethylenetriamine and polyethyleneimine; alkanolamines such as monoethanolamine, diethanolamine and triethanolamine Can be used. Moreover, those derivatives, for example, those to which alkylene oxide is added can also be used. Of these, the most preferred amines are alkanolamines, and triethanolamine is most preferred.

  In addition to these, a general anionic surfactant, nonionic surfactant, preservative, antifungal agent, nonferrous metal anticorrosive agent, antifoaming agent, pH buffering agent and the like may be appropriately contained as necessary. . Further, bentonite compounds, cellulose polymer compounds, and the like that have been widely used in the past can be added in order to cope with various performances of the slurry during mixing of abrasive grains.

  The above-described water-soluble oil for cutting is used as a slurry mixed with abrasive grains when cutting a workpiece. The water-soluble oil for cutting process of the present invention can be particularly preferably used for cutting process of silicon ingot. Since the oxidizer component suppresses the reaction between the active silicon fine powder and the water in the water-soluble oil for cutting, it effectively prevents the generation of hydrogen gas and the increase in slurry viscosity during the cutting process. Can do.

The present invention will be specifically described below with reference to examples.
The water-soluble oil for cutting processing of the present invention (Examples 1 to 6) and the water-soluble oil for cutting processing other than the present invention (Comparative Examples 1 to 3) were prepared so as to have the compositions shown in Table 1. Table 1 also shows the pH measured by the glass electrode method in accordance with JIS Z 8802 for each of the prepared water-soluble oils for cutting processing. Moreover, the measured value in a table | surface The numbers other than pH in the table | surface have shown the mass% in the water-soluble oil agent for cutting processes.

About the created sample oil agent, the following operation was performed and the slurry viscosity and hydrogen gas generation amount in each step were measured.
(1) To 100 g of each sample oil, 20 g of silicon powder (purity 99%, particle diameter 2 μm) and 100 g of abrasive grains (GC800 (manufactured by Shinano Denki Co., Ltd.)) are added. For Example 6, hydrogen peroxide is also added here. After stirring and mixing, the slurry viscosity (η0) is measured.
(2) 100 g of a stainless steel ball (diameter 2 mm) is added to the slurry of (1) and stirred at 1000 rpm for 10 hours to pulverize the silicon powder. After filtering through a wire mesh (50 mesh) and removing the stainless steel balls, the slurry viscosity (η1) is measured.
(3) Put the slurry treated in (2) in a sealed container with a gas collection tube, leave it in a thermostatic bath at 50 ° C. for 24 hours, and then measure the amount of hydrogen gas generated. Further, the slurry viscosity (η2) after being left for 24 hours is measured.

  The viscosity (η0 to η2) is a value measured with a rotational viscometer at 25 ° C. in accordance with JIS K 7117. The results are shown in Table 2.

  From Table 2, the viscosity of the slurry using the water-soluble oil for cutting processing (Comparative Examples 1 to 3) containing no oxidizing agent is the value (η2) after pulverization and standing for 24 hours before pulverization. It can be seen that the value is one digit larger than the value (η0). In addition, it can be seen that the amount of hydrogen gas generated is very large at 30 ml or more for all the water-soluble oils for cutting processing of the comparative example. On the other hand, the viscosity of the slurry using the water-soluble oil for cutting process (Examples 1 to 6) of the present invention is the value after leaving the powder for 24 hours after pulverization from the value (η0) before pulverization of the silicon powder. No significant change in viscosity was seen up to the value (η2). Furthermore, hydrogen gas was hardly generated in the case of using the water-soluble oil for cutting process of the present invention. From this, it is understood that the reaction between water and silicon is effectively suppressed by adding an oxidizing agent to the water-soluble oil for cutting work as in the present invention.

  While the present invention has been described in connection with embodiments that are presently the most practical and preferred at the present time, the present invention is not limited to the embodiments disclosed herein. However, the present invention can be changed as appropriate without departing from the gist or concept of the invention that can be read from the claims and the entire specification, and a water-soluble oil for cutting process and a modifier for the same are also included in the present invention. It should be understood as encompassed within the technical scope.

Claims (6)

A water-soluble oil modifier for cutting, which contains an oxidizing agent. The water-soluble oil modifier for cutting processing according to claim 1, wherein the oxidizing agent is hydrogen peroxide. A water-soluble oil for cutting, which contains an oxidizing agent. The water-soluble oil for cutting work according to claim 3, wherein the oxidizing agent is hydrogen peroxide. 5. The water-soluble oil for cutting according to claim 3, wherein the content of the oxidizing agent is 0.1 to 10% by mass based on the total amount of the water-soluble oil for cutting. The water-soluble oil for cutting according to any one of claims 3 to 5, which is for cutting a silicon ingot.