JPH0775784A - Method for producing water including more excessive hydrogen ions or hydroxide ions than counter ions and water thus obtained - Google Patents

Abstract

PURPOSE:To provide a technique which is suitable for washing or surface treatment and by which water contg. hydrogen ions or hydroxide ions of more excessive concentration than counter ions that is easily subjected to waste liquid treatment is effectively produced, and to provide the water contg. hydrogen ions or hydroxide ions of more excessive concentration than counter ions. CONSTITUTION:In a method for producing water contg. more excessive hydrogen ions or hydroxide ions than counter ions, an electrolyzer of a three-chamber construction consisting of an anode chamber 9 provided with an anode electrode 2, a cathode chamber 8 provided with a cathode electrode 1 and an intermediate chamber 5 put between the anode chamber 9 and the cathode chamber 8 is used. Water is fed to the anode chamber 9 and/or the cathode chamber 8, and also electrolytic treatment is made on condition that there is electrolyte in the intermediate chamber 5 to produce water contg. hydrogen ions or hydroxide ions of more excessive concentration than counter ions.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to water suitable for cleaning various pollutants and surface treatment of industrial materials.

[0002]

BACKGROUND OF THE INVENTION Water pH and redox capacity have very important implications in the field of cleaning or surface treatment. Below, an outline will be given of what role the pH and redox capacity of water play in these fields, and how the pH and redox capacity of water are controlled.

The contaminants to be cleaned are roughly classified into ionic substances, reaction products, liquids and particulate substances.
Contaminant forms of ionic substances include adsorption due to ion exchange found on the glass surface, adhesion due to electrostatic attraction of ions found on the surface of semiconductors and metals, and adsorption of ions on the surface layer of semiconductors, metals and ceramics. An example is invasion by diffusion.

The form of contamination by reaction products is classified into deposits and adhesion of impurities in water such as boiler scales, oxide films formed on metal surfaces, and rust. Compared with this, the form of contamination by particulate matter is complicated, that is, adhesion by chemical bond, adhesion by physicochemical bond such as van der Waals force or hydrogen bond, physical adhesion by electrostatic force or magnetic force, etc. Is mentioned.

Among these pollutants, ionic substances are generally washed with pure water or ultrapure water,
For example, when cleaning semiconductors, the electrical resistivity is about 18M.
Ω / cm ultrapure water is used. The reaction product is usually washed with chemicals. For example, the above-mentioned scale and the like use a drug in which an acid and a chelating agent are combined, and in particular, citric acid, ethylenediaminetetraacetic acid, and nitrilotriacetic acid, which have both functions, are used.

Next, regarding surface treatment, the rate at which the oxide film on the metal surface is removed by dissolution largely depends on the pH of the aqueous solution and the redox ability. For example, iron trioxide (Fe ₃ O ₄ ) forming an iron oxide film is p
H is an acid of about 4 or less and is rapidly dissolved in an aqueous solution having a reducing property. Incidentally, typical agents used for dissolving the metal oxide film include oxalic acid having both functions of an acid and a reducing agent, and a combination of citric acid and ethylenediaminetetraacetic acid.

Among metals, the surface oxide film of chromium steel dissolves in an oxidizing aqueous solution. Typical agents used for this treatment include a combination of sodium hydroxide and potassium permanganate, and a combination of hydrofluoric acid and nitric acid. In the field of silicon wafer cleaning, a cleaning process may be carried out by etching the surface layer. For this process, a combination of ammonia water and hydrogen peroxide solution, sodium hydroxide, or nitric acid is used. Etc. are used.

To remove the liquid or film-like contaminants adhering to the silicon wafer or the like, a method of oxidatively decomposing or dissolving the contaminants is applied. Examples thereof include a combination of sulfuric acid and hydrogen peroxide, a combination of ammonium hydroxide and hydrogen peroxide, and the like. When dissolving contaminants that are inorganic substances, hydrochloric acid and hydrogen peroxide,
A combination of sulfuric acid and hydrogen peroxide, hydrochloric acid and nitric acid, and sulfuric acid and nitric acid is used.

Further, in case of dissolving a pollutant which is an organic substance, an organic chlorine type solvent such as trichloroethane or dichloromethane is used. As is clear from the above explanation,
The pH of water and its redox capacity play important roles in cleaning and surface treatment. By the way, as a means for making the pH of water acidic or alkaline and imparting redox ability, there are a method of adding a chemical agent and a method of utilizing electrolysis (hereinafter referred to as electrolysis).

When a chemical is used to shift the pH to acidic, an acid is used, and therefore, an anion such as Cl ⁻ , SO ₄ ²⁻ , NO ₃ ⁻ , CH ₃ COO ⁻ as a counter ion of H ⁺ . Exists. On the other hand, when the pH is shifted to alkaline, a base is used, so that metal ions such as Na ⁺ , K ⁺ and Ca ²⁺ coexist as counter ions of OH ⁻ .

That is, when chemicals are used, it is virtually impossible to add H ⁺ and OH ⁻ without the presence of counter ions. In view of such circumstances, as a method of controlling pH without using a chemical agent, an electrolytic method,
In particular, a diaphragm electrolysis method using a device in which a diaphragm is provided between the cathode electrode and the anode electrode has begun to be considered.

However, in the conventional diaphragm electrolysis device,
Since the cathode electrode, the diaphragm, and the anode electrode are widely separated from each other, it is an essential condition to reduce the electrical resistivity of the aqueous solution, and a predetermined amount of electrolyte such as salts must be added.
By the way, when the solution in which the added salt is ionized into anion and cation is electrolyzed, the anion moves to the anode electrode and the cation moves to the cathode electrode. As a result, the anode side becomes acidic, while the cathode side becomes alkaline. However, when H ⁺ and OH ⁻ are generated by this method, counter ions also increase accordingly, and Such a problem is caused.

That is, when an acid or alkali and a redox agent are used for cleaning or surface treatment, H
Equimolar counterions coexist with ⁺ and OH ⁻ , and after cleaning or surface treatment, the materials are deteriorated due to the residual of these counterions and the treatment of the waste liquid becomes difficult. For example, if halogen ions that promote corrosion such as Cl ⁻ remain on the surface of the metal after cleaning, rapid progress of corrosion is feared. Further, if ionic impurities remain in the semiconductor after cleaning, the performance of the semiconductor is significantly deteriorated.

Further, in connection with these problems, it is necessary to carry out a rinsing operation after cleaning in order to remove residual ions and the like, and a large amount of ultrapure water of several thousand liters is used per silicon wafer. This is the current situation.
However, in recent years, water resources themselves and pollution problems have become serious, and technical development for reducing the amount of water used is desired.

[0015]

DISCLOSURE OF THE INVENTION As a result of earnestly advancing the research on the above problems, the present inventor has found that water used in cleaning or surface treatment includes water containing hydrogen ions or hydroxyl ions in excess of counter ions. We have come to the knowledge that cleaning and surface treatment can be performed effectively if used. It was also found that water containing hydrogen ions or hydroxyl ions in excess of the counter ions can be obtained by electrolytic means.

First, the redox reaction of a solute and the redox reaction of H ₂ O molecules when electrolytically treating an aqueous solution will be described. The following reaction formulas (1) to (11) are considered as reaction formulas related to the redox reaction of H ₂ O. _{^{2H + + 2e - ⇔ H 2}} E O = 0.01V (1) O 2 + 2H + + 2e - ⇔ H 2 O 2 E O = 0.69V (2) H 2 O 2 + H + + 2e - ⇔ OH - + H 2 O E _O = 0.71V (3) O ₂ + 4H ⁺ + 4e ⁻ ⇔ 2H ₂ O E _O = 1.22V (4) HO ₂ + H ⁺ + e ⁻ ⇔ H ₂ O ₂ E _O = 1.495V (5) H ₂ O ₂ + 2H ⁺ + 2e ⁻ ⇔ 2H ₂ O E _O = 1.77V (6) OH + H ⁺ + e ⁻ ⇔ H ₂ O E _O = 2.85V (7) 2H ₂ O + 2e ⁻ ⇔ H ₂ + 2OH ⁻ E _O = 0. 82V (8) O ₂ + 2H ₂ O + 4e ⁻ ⇔ 4OH ⁻ E _O = 0.401V (9) HO ₂ ⁻ + H ₂ O + 2e ⁻ ⇔ 3OH ⁻ E _O = 0.76V (10) OH + e ⁻ ⇔ OH ⁻ E _O = 2 0.02 V (11) where E ₀ is the standard redox potential.

[0017] Considering the reaction formula (1) to (11), by a redox reaction of ^{_{H 2 O, H +, OH}} -, OH
_{-Radical, H 2, O 2,} H 2 O 2, HO 2 , etc. It can be seen to be generated. Further, in the aqueous solution, normally, O ₂ ,
Although N ₂ and CO ₂ are dissolved in a small amount, it is necessary to take into consideration the redox reaction of these molecules at the same time.

When O ₂ exists in an aqueous solution, the following reaction formulas are considered in addition to the above formulas (1) to (11). ^{_{O 2 + e - ⇔ O 2}} - E O = -0.563V (12) O 2 + H + + e - ⇔ HO 2 E O = -0.13V (13) O 2 + H 2 O + 2e - ⇔ HO 2 - + OH - E _{O = -0.076V (14) O 2} + 2H + + 2e - ⇔ H 2 O 2 E O = 0.6824V (15) O 3 + H 2 O + 2e - ⇔ O 2 + 2OH - E O = 1.24V (16) next In addition, when N ₂ is present in the aqueous solution, the following reaction formula can be considered.

N ₂ + 4H ₂ O + 4e ⁻ ⇔ N ₂ H ₄ + 4OH ⁻ E = −1.15V (17) 2NO ₃ ⁻ + 12H ⁺ + 10e ⁻ ⇔ N ₂ + 6H ₂ O E = −1.24V (18) N ₂ H ₄ + 8H ⁺ + 8e ⁻ ⇔ N ₂ + 4H ₂ O E = 1.35V (19) 2HNO ₂ + 6H ⁺ + 6e ⁻ ⇔ N ₂ + 4H ₂ O E = 1.44V (20) 2NO + 4H ⁺ + 4e ⁻ ⇔ N ₂ + 2H ₂ O E = 1.68V (21) Further, when CO ₂ exists in the aqueous solution, the following reaction formula is considered as a typical one.

2CO ₂ + 2H ⁺ + 2e ⁻ ⇔ H ₂ C ₂ O ₄ E = −0.49V (22) CO ₂ + 2H ⁺ + 2e ⁻ ⇔ CO + H ₂ O E = −0.12V (23) CO ₂ + 2H ⁺ + 2e ⁻ ⇔ HCOOH E = -0.199V (24) However, E is a standard oxidation-reduction potential. Above (1) ~
Considering the equations up to (24), from O ₂ to O ₂ ⁻ , H
Oxides and reducing agents such as O ₂ , O ₃ and H ₂ O ₂ and OH ⁻ are produced, and N ₂ is converted to N ₂ H ₄ , NO ₃ ⁻ and N ₂ O.
₄ , HNO ₂ , NO and H ⁺ are produced.

Here, it should be noted that H ₂ O,
H ₂ O-O ₂ and H ₂ O-N ₂ system is produced from H ⁺ and OH ^- are not balanced with each counter ion, as compared to in other words counterion, H ⁺ and OH
^- is what is generated excessively. Incidentally, H ₂ O-CO
_{In the 2} system, only the reduction reaction occurs, and the product is an organic acid. Therefore, this is the same as the above H ₂ O, H ₂ O—O ₂ , H ₂ O.
It is significantly different from the reaction of the -N ₂ system.

When the electrolysis method is used to cause the above-mentioned redox reaction, the electrolysis reaction depends on the solute concentration, the structure of the electrolytic cell and the electrolysis conditions. It is desirable to have a diaphragm structure in order to separate each ion from the viewpoint of the structure. And
The current density is preferably such that the decomposition of H ₂ O occurs rather than the redox reaction of the solute.

By the way, since pure water has an extremely high electric resistivity, it is extremely difficult to electrolyze, and it is necessary to add an electrolyte in order to lower the electric resistivity. However, when electrolyzing an aqueous solution to which an electrolyte is added, it is extremely difficult to generate an excessive concentration of H ⁺ or OH ⁻ as compared with a counter ion, because the ions existing in the aqueous solution move. .

For example, when an aqueous solution of NaCl is electrolyzed, a reaction of Na ⁺ + e ⁻ ⇒ Na (25) 2Na + 2H ₂ O ⇒ 2Na ⁺ + 2OH ⁻ + H ₂ (26) occurs at the cathode electrode, while 2Cl ⁻ at the anode electrode. -2e ^- ⇒ since Cl ₂ (27), such reaction occurs, it is impossible to break the balance of ions.

Therefore, regardless of whether or not an electrolyte is present,
No, H₂OO₂System and H₂ON₂Efficient system electrolysis reaction
If done well, excess compared to counterions
H of various concentrations⁺Or OH^-With what can generate
Yes, that is, O as described above ₂And N₂Redox reaction
H generated from⁺And OH^-Balances with counterions
H is because it is not₂You only need to consider the reaction of O
I understand.

In order to produce water containing excess H ⁺ or OH ⁻ with high efficiency, it is sufficient to increase the ionization degree of H ₂ O as compared with the solute in the aqueous solution as described above. , H ₂
In order to increase the degree of ionization of O, it is necessary to make the solute concentration as low as possible. However, if the concentration of solute is lowered, the electric resistivity becomes high, and the electrolytic treatment becomes extremely difficult.

In view of the above circumstances, the present inventor has earnestly pursued further research, and as a result, the anode chamber in which the anode electrode was immersed, the cathode chamber in which the cathode electrode was immersed, and these anodes Using an electrolytic cell with a three-chamber structure consisting of an intermediate chamber sandwiched between a cathode chamber and a cathode chamber, if electrolytic treatment is performed in a state where an electrolyte is present in the intermediate chamber, even if the solute concentration in the cathode chamber and the anode chamber is zero, H ₂ O
It has been found that the electrolysis of is possible. At this time, H ₂
The solute in the intermediate chamber is also electrolyzed at the same time as the electrolysis of O. However, if the electrolysis current is increased above the moving speed of the solute, the electrolysis of H ₂ O can be performed without any problem.

The present invention has been made on the basis of the above findings, and the object of the present invention is suitable for cleaning or surface treatment, and moreover, hydrogen ion or water at a concentration higher than that of the counter ion which is easy to treat waste liquid. It is an object of the present invention to provide a technique for efficiently producing water containing acid ions, and to provide water containing hydrogen ions or hydroxide ions in a concentration higher than that of counter ions. The object of the present invention is a method for producing water containing hydrogen ions or hydroxide ions in excess of counterions, wherein the anode chamber is provided with an anode electrode, and the cathode chamber is provided with a cathode electrode, An electrolytic cell having a three-chamber structure consisting of an intermediate chamber sandwiched between the anode chamber and the cathode chamber is used, water is supplied to the anode chamber and / or the cathode chamber, and an electrolyte is present in the intermediate chamber. This is achieved by a method for producing water containing hydrogen ions or hydroxide ions in excess of counter ions, which is characterized by performing electrolytic treatment.

A method for producing water containing hydrogen ions or hydroxide ions in excess of counter ions, wherein the anode chamber is provided with an anode electrode, the cathode chamber is provided with a cathode electrode, and the anode is provided. Chamber and a middle chamber sandwiched between the cathode chamber and a three-chamber structure electrolytic cell is used, water is supplied to and discharged from the anode chamber and / or the cathode chamber, and an electrolyte is present in the middle chamber. This is achieved by a method for producing water containing hydrogen ions or hydroxide ions in excess of counter ions, which is characterized by performing electrolytic treatment.

Further, an electrolytic cell having a three-chamber structure comprising an anode chamber provided with an anode electrode, a cathode chamber provided with a cathode electrode, and an intermediate chamber sandwiched between the anode chamber and the cathode chamber is used. Water is supplied to the chamber and / or the cathode chamber, and the intermediate chamber is subjected to electrolytic treatment under the condition that an electrolyte is present. To be achieved.

Further, an electrolytic cell having a three-chamber structure consisting of an anode chamber provided with an anode electrode, a cathode chamber provided with a cathode electrode, and an intermediate chamber sandwiched between the anode chamber and the cathode chamber is used, and the anode is provided. Water is supplied to and discharged from the chamber and / or the cathode chamber, and the intermediate chamber contains hydrogen ions or hydroxide ions in excess of the counter ions obtained by performing electrolytic treatment in the presence of an electrolyte. Achieved by water.

In the above invention, the water supplied to the anode chamber and / or the cathode chamber has a conductivity of 3000 μS.
/ Cm or less of water, preferably with a conductivity of 2000 μS / c
Water having a volume of m or less is preferable, and the electrolyte present in the intermediate chamber is preferably a vaporizable substance, particularly one selected from the group consisting of nitrates, amine compounds and organic acid salts. Then, it is preferable that an oxidizing and / or reducing substance is made to coexist in water containing hydrogen ions or hydroxyl ions in excess of the obtained counter ions.

The water containing hydrogen ions in excess of the counter ions in the present invention is water having a pH lower than the calculated pH based on the hydrogen ion concentration equal to the counter ion concentration, and In the present invention, the water containing more hydroxide ions than the counter ions is water having a pH higher than the calculated pH based on the concentration of the counter ions and the concentration of the hydroxide ions.

The present invention will be specifically described below with reference to examples.

[0035]

【Example】

[Embodiment 1] FIGS. 1 and 2 show an embodiment of the present invention. FIG. 1 is a schematic sectional view of an electrolytic cell, and FIG. 2 is a piping diagram showing a connection state between the electrolytic cell and various tanks. Is. In each figure, 1 is a cathode pole, 2 is an anode pole, and 3 and 4 are diaphragms. As shown in FIG. 1, the cathode pole 1 and the anode pole 2 are
An intermediate chamber 5 is formed in a portion sandwiched by the diaphragms 3 and 4 which are arranged so as to face each other.

6 is a container for accommodating the above electrodes and diaphragm, and 7
Is a DC power source provided outside, 8 is a cathode chamber, and 9 is an anode chamber. Reference numeral 10 is a pure water producing device, and a pump 1
Pure water (conductivity of 0.06 μS / cm) produced by the pure water producing apparatus 10 by the action of 1 is supplied to the cathode chamber 8 and the anode chamber 9.

Reference numeral 12 is a liquid receiving tank into which the liquid in the electrolytically treated cathode chamber 8 is fed, and 13 is also a liquid receiving tank into which the liquid in the electrolytically treated anode chamber 9 is fed.
14 is an electrolytic solution tank filled with an electrolytic aqueous solution,
The aqueous electrolyte solution in the electrolytic solution tank 14 is configured to be sent into the intermediate chamber 5 by the action of the pump 15.

There is a strong tendency that the catholyte in the cathode chamber 8 becomes alkaline and the anolyte in the anode chamber 9 becomes acidic by the electrolytic treatment. Therefore, it is desirable that the material of the cathode 1 has excellent alkali resistance, and for example, platinum, palladium, gold, carbon steel, stainless steel, silver, copper, graphite, vitreous carbon and the like are preferably used.

The material of the anode 2 is preferably one that is excellent in acid resistance and is difficult to oxidize. For example, Pt, Ru, Ir, Pd, β-PbO ₂ , NiFe ₂ O.
₄ , glassy carbon is desirable. As the diaphragms 3 and 4, cellulose or synthetic polymer materials (PE, PP, PE
T, PTFE, etc.) filter or perforated film,
An ion exchange membrane is mentioned.

The diaphragms 3 and 4 may be a combination of these filters, a perforated film and an ion exchange membrane. Particularly, as the ion exchange membrane, OH ^- is the intermediate chamber on the cathode electrode 1 side. A strong or weakly acidic cation exchange membrane is used to prevent the migration of H ⁺ into the intermediate chamber 5, and a strong base or a weak base is used to prevent H ⁺ from moving into the intermediate chamber 5. It is preferable to use an anion exchange membrane.

When the solute in the intermediate chamber 5 needs to move into the cathode chamber 8 and the anode chamber 9, a stack of strongly acidic and strongly basic ion exchange membranes is used as the ion exchange membrane. It suffices to use it, or a combination of weakly acidic and weakly basic ion exchange membranes may be used. In addition to the above-mentioned use of the diaphragms 3 and 4, as means for suppressing the movement of solute,
There is a method of lowering the solute concentration in the intermediate chamber 5. However, in this method, since the electrical resistivity becomes too high, the intermediate chamber 5 is filled with the granular ion exchange resin.

The criteria for selecting the electrolyte to be dissolved in the aqueous electrolyte solution sent to the intermediate chamber 5 differs depending on the object of cleaning or surface treatment. That is, in the case of cleaning semiconductors such as silicon wafers, it is desirable to use an electrolyte that vaporizes at a temperature as low as possible in order to suppress ion retention as much as possible. For example, ammonium carbonate, ammonium hydrogen carbonate, hydrazine sulfate,
Examples thereof include amine compounds such as hydrazine chloride, ammonium nitrate and morpholine, carbonates such as sodium carbonate and sodium hydrogen carbonate, nitrates, and further nitrites.

In order to facilitate the waste treatment of cleaning or surface treatment, an electrolyte which does not adversely affect the environment and which can be discarded as it is by mixing the anolyte and the catholyte is desirable. NaCl, Na ₂ SO ₄ , KC
1, sodium salts such as K ₂ SO ₄ and sulfates. The electrolyte concentration in the intermediate chamber 5 is not limited at all,
It is preferably in the range of 1 × 10 ^{−3 to 5} mol / l. When the intermediate chamber 5 is filled with the granular ion exchange resin, the range of 1 × 10 ^{−6 to} 5 × 10 ⁻³ mol / l is desirable.

The electrolyte concentration in the cathode chamber 8 and the anode chamber 9 is preferably 1 × 10 ^-2 mol / l or less. The electrolyte concentration is 1 × 10 ^-2 mol / l
Has a conductivity of about 1000 μS / cm. Furthermore, the electrolytic current density is preferably 5 mA / cm ² or more. The electrolytic cell configured as described above was arranged as shown in FIG. 2, and electrolytic treatment was performed under the following conditions to obtain water containing hydrogen ions or hydroxide ions in excess of counter ions.

That is, in the electrolytic cell shown in FIG. 1, needle-punched SUS304 steel plate was used for the cathode 1 and 80 mesh platinum was used for the anode 2. The vertical and horizontal dimensions of the electrode were 80 × 60 mm. The diaphragm 3 on the cathode 1 side has a basis weight of 80 g / mm ²
The PP non-woven fabric and cation exchange membrane (CMH manufactured by Tokuyama Soda Co., Ltd.) are used for the diaphragm 4 on the anode 2 side, and the PP non-woven fabric and anion exchange membrane (AMH manufactured by Tokuyama Soda Co., Ltd.) are used.
Was used. The distance t between the diaphragm 3 and the diaphragm 4 was about 6 mm.

The flow rate of pure water (conductivity 0.06 μS / cm) sent from the pure water producing apparatus 10 is 200 cc / min.
In the intermediate chamber 5, the concentration from the electrolyte tank 14 is 1 mo.
A 1 / l aqueous NaCl solution was sent. The electrolysis current density was set to 80 mA / cm ² . When pH and redox potential of the electrolytically treated liquid were examined, the pH of the catholyte measured with a glass electrode was about 12.2, and the redox potential measured with a silver-silver chloride electrode was about -900 mV.
(VsAg / AgCl).

On the other hand, the pH of the anolyte is 2.2,
The redox potential was 1180 mV (vsAg / AgCl). Then, elemental analysis of the catholyte revealed that N
The concentration of a is about 2.5 × 10 ⁻³ mol / l, and similarly, the concentration of Cl in the anolyte is about 2.1 × 10 ^−3.
It was mol / l. That is, compared with the OH ⁻ and H ⁺ concentrations converted from the measured pH, Na ⁺ and Cl ⁻
It can be seen that the concentration of OH was small and excess OH ⁻ or H ⁺ was produced over the counter ion.

PH = 1 adjusted by dissolving NaOH
The redox potential in the alkaline aqueous solution of No. 2 is about -200.
mV, and the redox potential in an aqueous solution of pH = 2.2 adjusted with HCl was about +150 mV.
From this, it is understood that the electrolytic treatment produced a reducing substance in the catholyte and an oxidizing substance in the anolyte.

A cleaning test was performed using the aqueous solution stored in the liquid receiving tanks 12 and 13, and the results are shown in Table 1 below. The object to be cleaned is
Prepare a preparation coated with cutting oil and a preparation to which fingerprints are attached, and these preparations are heated to 50 cc.
Washing was performed at a flow rate of / min for 2 minutes.

For comparison, an aqueous solution of NaOH and HCl are used.
A similar cleaning test was performed using an aqueous solution. Table-1 Alkaline water Acidic water Electrolyzed water (Invention) NaOH aqueous solution Electrolyzed water (Invention) HCl aqueous solution Cutting oil Normal effect--Fingerprint--Effect normal [Example 2] Using the same apparatus as in Example 1, A 1 mol / l ammonium hydrogen carbonate aqueous solution is supplied to the intermediate chamber 5 as an electrolyte aqueous solution, and the cathode chamber 8 and the anode chamber 9 are supplied.
Was supplied with pure water at a flow rate of 100 cc / min. Then, electrolytic treatment is performed at an electrolytic current density of 25 mA / cm ² ,
Water containing hydrogen ions or hydroxyl ions in excess of counter ions was obtained in the liquid receiving tanks 12 and 13.

When the pH and the redox potential of the liquid subjected to the electrolytic treatment were examined, the pH of the catholyte measured with the glass electrode was about 11.3, and the redox potential measured with the silver-silver chloride electrode was About -800mV (vsAg / Ag
Cl). On the other hand, the pH of the anolyte was 3.2, and the redox potential was +950 mV (vsAg / AgC).
l).

In the above electrolytic treatment, it was confirmed that the pH returned to neutral over time (after about 2 hours, the pH of the catholyte became 9.0 and the pH of the anolyte became 5.0). Was done. That is, this shows that the disposal of the electrolytic solution is extremely easy. A cleaning test was performed using the aqueous solution stored in the liquid receiving tanks 12 and 13, and the results are shown in Table 2 below.

As the objects to be cleaned, a preparation to which cutting oil was applied and a preparation to which fingerprints were attached were prepared, and these preparations were washed at a flow rate of 50 cc / min for 2 minutes. Also, for comparison, pH = 1
0.5 liters of 1.3 NH ₄ OH aqueous solution and CO ₂ gas
H ₂ CO ₃ obtained by bubbling pure water at a flow rate of min
A washing test was similarly performed using an aqueous solution.

Table-2 Alkaline Water Acidic Water Electrolyzed Water (Invention) NH ₄ OH Aqueous Solution Electrolyzed Water (Invention) H ₂ CO ₃ Aqueous Solution Cutting Oil Normal Effect--Fingerprint ---- Effective Effect No Effect [Example 3] The intermediate chamber 5 of the electrolytic cell shown in FIG. 1 was filled with cation exchange resin particles (Nafion NR-50 manufactured by DuPont). This electrolytic cell is arranged as shown in FIG. 2, pure water having an electric resistivity of 1 MΩ / cm is supplied to the cathode chamber 8 and the anode chamber 9 at a flow rate of 200 cc / min, and the intermediate chamber 5 has a concentration of 1%. A × 10 ⁻⁴ mol / l NaCl aqueous solution was supplied. Then, electrolysis was performed at an electrolysis current density of 40 mA / cm ² to obtain water containing hydrogen ions or hydroxyl ions in excess of counter ions.

When the pH and redox potential of the electrolytically treated liquid were examined, the pH of the catholyte measured with a glass electrode was about 10.8, and the redox potential measured with a silver-silver chloride electrode was About -700mV (vsAg / Ag
Cl). On the other hand, the pH of the anolyte was 3.7, and the redox potential was +1050 mV (vsAg / AgC).
l).

The Na ⁺ concentration in the catholyte is about 1 × 10.
^-4 mol / l, on the other hand, the Cl ^- concentration of the anolyte is about 8 x 10 ^-5 mol / l, and an excess of OH ^- or H ^+.
It can be seen that is generated.

[0057]

[Effect] Water containing hydrogen ions or hydroxide ions in excess of counter ions can be efficiently obtained, and this water is extremely effective in cleaning and surface treatment.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of an electrolytic cell.

FIG. 2 is a piping diagram showing a connection state of an electrolytic cell and various tanks.

[Explanation of symbols]

 1 Cathode electrode 2 Anode electrode 3,4 Diaphragm 5 Intermediate chamber 6 Container 7 DC power source 8 Cathode chamber 9 Anode chamber 10 Pure water production device 11,15 Pump 12,13 Liquid receiving tank 14 Electrolyte tank

Claims (9)

[Claims] 1. A method for producing water containing hydrogen ions or hydroxide ions in excess of counter ions, comprising an anode chamber having an anode electrode, a cathode chamber having a cathode electrode, and the anode. Using an electrolyzer having a three-chamber structure consisting of an intermediate chamber sandwiched between a cathode chamber and a cathode chamber, water is supplied to the anode chamber and / or the cathode chamber, and electrolytic treatment is performed under the condition that an electrolyte is present in the intermediate chamber. A method for producing water containing hydrogen ions or hydroxide ions in excess of the counter ions. 2. A method for producing water containing hydrogen ions or hydroxide ions in excess of counter ions, the anode chamber having an anode electrode, the cathode chamber having a cathode electrode, and the anode. Chamber and a middle chamber sandwiched between the cathode chamber and a three-chamber structure electrolytic cell is used, water is supplied to and discharged from the anode chamber and / or the cathode chamber, and an electrolyte is present in the middle chamber. A method for producing water containing hydrogen ions or hydroxide ions in excess of counter ions, which is characterized by performing electrolytic treatment. 3. The hydrogen ion or hydroxy acid rather than the counter ion of claim 1 or 2, wherein the water supplied to the anode chamber and / or the cathode chamber is water having an electric conductivity of 3000 μS / cm or less. A method for producing water containing excess ions. 4. The production of water containing hydrogen ions or hydroxide ions in excess of the counter ions according to claim 1 or 2, wherein the electrolyte present in the intermediate chamber is a vaporizable substance. Method. 5. The electrolyte existing in the intermediate chamber is nitrate.
A method for producing water containing hydrogen ions or hydroxide ions in excess of the counter ions of claim 1 or 2, which is selected from the group consisting of amine compounds and organic acid salts. 6. An anode chamber provided with an anode electrode,
An electrolytic cell having a three-chamber structure including a cathode chamber provided with a cathode electrode and an intermediate chamber sandwiched between the anode chamber and the cathode chamber is used to supply water to the anode chamber and / or the cathode chamber and Water containing hydrogen ions or hydroxide ions in excess of the counter ions obtained by performing electrolytic treatment under the condition that an electrolyte is present in the chamber. 7. An anode chamber provided with an anode electrode,
Using a three-chambered electrolytic cell consisting of a cathode chamber provided with a cathode electrode and an intermediate chamber sandwiched between the anode chamber and the cathode chamber, while supplying and discharging water to the anode chamber and / or the cathode chamber, Water containing hydrogen ions or hydroxide ions in excess of the counter ions obtained by performing electrolytic treatment under the condition that an electrolyte is present in the intermediate chamber. 8. The water containing hydrogen ions or hydroxide ions in excess of the counter ions of claim 6 or 7, wherein the electrolyte present in the intermediate chamber is a vaporizable substance. 9. Water containing a hydrogen ion or a hydroxide ion in excess of the counter ion of claim 6 or 7, wherein an oxidizing and / or reducing substance is allowed to coexist.