JPH0873205A - Purification method of hydrogen peroxide water - Google Patents

Abstract

(57) [Abstract] [Purpose] Metallic impurities, especially Al, Fe and Cr are 2p
Provided is a purification method for obtaining highly pure hydrogen peroxide water that has been removed to a low concentration of pb or less, and even 1 ppb or less. [Composition] In purifying hydrogen peroxide water, 25
An acid having an acid dissociation index pKa at 5 ° C. of 5 or less is added in an amount of 0.005 to 5 meq.
After that , it is contacted with an H-type strongly acidic cation exchange resin having a sulfonic acid group or a mixed bed of an H-type strongly acidic cation exchange resin having a sulfonic acid group and a strong base anion exchange resin.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention is a method for safely purifying hydrogen peroxide water containing impurities, particularly inorganic impurities, to produce hydrogen peroxide water of extremely high purity. The hydrogen peroxide solution purified by the present invention is particularly suitable for use in the semiconductor manufacturing field.

[0002]

2. Description of the Related Art At present, hydrogen peroxide is mainly produced by an auto-oxidation method, but various inorganic impurities such as Al resulting from the material of the equipment are mixed in the hydrogen peroxide water produced by this method. Therefore, it is usual that a practical use concentration of 10 to 70% by weight of hydrogen peroxide water contains several hundred μg / liter of inorganic impurities. However, the standard standard of inorganic impurities required for high-purity hydrogen peroxide solution used in the semiconductor manufacturing field is several μg /
It is liter or less and needs to be purified to a higher purity.

Conventionally, as a method for removing and purifying these inorganic impurities contained in hydrogen peroxide solution, it is possible to remove the cationic metallic impurities by bringing the hydrogen peroxide solution into contact with a strongly acidic cation exchange resin. Although it has been proposed, by simply contacting the strongly acidic cation exchange resin with aqueous hydrogen peroxide, easily soluble strong cationic metal-based impurities such as Na are removed, but they are not completely dissolved or weakly dissolved. Metallic impurities derived from metals that partially form cation, weak anion and strong anion forms are not removed. Examples of these include Al, Fe and Cr. Further, there is a problem that a large amount of sulfate is generated due to deterioration of the cation exchange resin due to contact with hydrogen peroxide solution.

On the other hand, following the cation exchange resin, a hydrogen peroxide solution is brought into contact with a hydroxide (OH) type strongly basic anion exchange resin having a quaternary ammonium group and a hydroxide ion as a counter ion in the structure. Therefore, a method of removing inorganic impurities that cannot be removed by the strongly acidic cation exchange resin is also known.

However, the use of the hydroxide type strongly basic anion exchange resin has the following problems.
One of them is that when the hydrogen peroxide solution comes into contact with the hydroxide type strongly basic anion exchange resin, the decomposition of the hydrogen peroxide solution is promoted due to the basicity of the resin. This decomposition is further promoted by the synergistic action of metallic impurities such as Fe and Cr in the hydrogen peroxide solution.

Further, even when the hydroxide type strong basic anion exchange resin is contacted, undissolved metallic impurities, weak cationic metallic impurities and weak anionic metallic impurities are hardly removed. It is difficult to obtain high-purity hydrogen peroxide solution required in the field of semiconductor manufacturing.

As a method for suppressing the decomposition of hydrogen peroxide solution, for example, in Japanese Patent Publication No. 35-16677, the salt form in the anion exchange resin is changed from hydroxide type to bicarbonate type or carbonate type. It has been shown that it is possible to use an anion exchange resin by reducing the basicity, and in JP-A-5-17105, acid is not added when the hydrogen peroxide solution is brought into contact with the anion exchange resin. A method for preventing decomposition of hydrogen peroxide solution by adding is disclosed.

However, even in these cases, undissolved metallic impurities, weakly cationic metallic impurities, and weakly anionic metallic impurities remain without being removed, and it is not possible to obtain highly pure aqueous hydrogen peroxide. Further, it is difficult to completely suppress the decomposition of hydrogen peroxide due to the influence of these remaining metallic impurities, and as a result, it is difficult to safely purify the hydrogen peroxide solution.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide a highly pure hydrogen peroxide solution in which metallic impurities, particularly Al, Fe, and Cr are removed to a low concentration of 2 ppb or less, further 1 ppb or less. It is an object of the present invention to provide a method for safely and efficiently producing hydrogen peroxide by sufficiently suppressing the decomposition thereof.

[0010]

Means for Solving the Problems The inventors of the present invention have made extensive studies to solve the above-mentioned problems. As a result, hydrogen peroxide solution to which an acid has been added in advance is used as a strong acid cation exchange resin alone or as a strong acid cation exchange resin. The present inventors have completed the present invention by finding that Al, Fe and Cr, which are usually difficult to completely remove, are removed to an extremely low concentration when brought into contact with a resin mixed bed of a strongly basic anion exchange resin.

That is, according to the present invention, when purifying hydrogen peroxide solution, an acid having an acid dissociation index pKa of 5 or less at 25 ° C. in water is added to the hydrogen peroxide solution in an amount of 0.005 to 1 liter of hydrogen peroxide solution. After adding 5 meq, H-type strongly acidic cation exchange resin having a sulfonic acid group as an ion exchange resin, or H type strongly acidic cation exchange resin and strong basic anion exchange resin in which the ion exchange resin has a sulfonic acid group The present invention relates to a method for purifying hydrogen peroxide solution, which comprises contacting with a mixed bed of

According to the present invention, conventional purification in which hydrogen peroxide solution and a strongly acidic cation exchange resin alone or a mixed bed of a strongly acidic cation exchange resin and a strongly basic anion exchange resin is simply contacted without adding an acid is used. It is possible to remove metal impurities, weak cationic metal impurities, and weak anionic metal impurities that are not dissolved in the hydrogen peroxide solution, which cannot be sufficiently removed by the method.

The acid added to the hydrogen peroxide solution is 25 ° C. in water.
Is an inorganic or organic acid having an acid dissociation index pKa of 5 or less, and an acid that reacts with hydrogen peroxide is not preferred.

As an example of the acid used in the present invention, sulfuric acid,
Inorganic acids such as nitric acid, hydrochloric acid, chlorous acid, hydrofluoric acid, phosphinic acid, phosphonic acid, phosphoric acid, diphosphoric acid, and tripolyphosphoric acid,
Further, carboxylic acids such as formic acid, acetic acid, chloroacetic acid, fluoroacetic acid, tartaric acid and benzoic acid, and organic acids such as phosphonic acids and sulfonic acids can be mentioned. Preferred among these are inorganic acids, especially sulfuric acid, nitric acid, hydrochloric acid and phosphoric acid. Most preferred is sulfuric acid or nitric acid.

The amount of acid added to the hydrogen peroxide solution is 0.0
05-5 meq / l -H ₂ O ₂ is suitable, but 0.005 meq / l -H ₂ O _2, in particular 0.01 to 0.5 meq / l -H ₂ O ₂ Is preferred. Here, milliequivalent / liter-H ₂ O ₂ represents the number of milliequivalents of the acid added to 1 liter of hydrogen peroxide solution.

The addition of acid to the hydrogen peroxide solution to be purified is
It suffices that the acid is added at the time when the purified hydrogen peroxide solution comes into contact with the strongly acidic cation exchange resin alone or the resin mixed bed comprising the strongly acidic cation exchange resin and the strongly basic anion exchange resin. That is, the acid may be added in advance to the storage tank of the hydrogen peroxide solution before mixing and mixed, or the strong acid cation exchange resin alone or may be continuously added to the liquid feed line to the resin mixing bed.

There is no particular limitation on the temperature of the hydrogen peroxide solution at the time of contact, but if the temperature is too high, decomposition of hydrogen peroxide will occur, which is not preferable, and too low temperature is not preferable.
Generally, the freezing point of the hydrogen peroxide solution is about 50 ° C, and more preferably the freezing point of the hydrogen peroxide solution is about 30 ° C.

The concentration of the hydrogen peroxide solution used in the method of the present invention is not particularly limited, but usually 5 to 60% by weight is used. The pH of hydrogen peroxide used again
Is generally 2.0 to 5.0 (2 depending on the content of impurities).
5 ° C).

In the method of the present invention, it is preferable that the acid is added to the hydrogen peroxide solution and then left in a homogeneous mixed state for aging. By allowing the acid-added hydrogen peroxide solution to stand for aging, the effect of removing impurities will be improved when the strongly acidic cation exchange resin alone or in contact with the resin mixed bed of the strongly acidic cation exchange resin and the strongly basic anion exchange resin. There is an advantage that can be enhanced. The aging time is preferably 6 hours or longer, more preferably 12 hours or longer, and most preferably 2 hours.
4 hours or more. The aging temperature is not particularly limited, but is preferably -10 to 50 ° C, more preferably 0 to 30 ° C.

The strongly acidic cation exchange resin used in the present invention is used as an H type strongly acidic cation exchange resin.
As a kind of the strongly acidic cation exchange resin, a strongly acidic cation exchange resin having a sulfonic acid group and having a network molecular structure is preferable. The strongly basic anion exchange resin used in the present invention has at least one kind of ion selected from the group consisting of hydroxide ion, carbonate ion and bicarbonate ion in the structure, and has a network molecule. It is a strongly basic anion exchange resin having a structure.

In the present invention, the strongly basic anion exchange resins having only one of these ions are referred to as hydroxide (OH) type, carbonate type and bicarbonate type strongly basic anion exchange resins, respectively. An example of the strongly basic anion exchange resin is an anion exchange resin having a quaternary ammonium group.

In the method of the present invention, when a resin mixed bed of a strongly acidic cation exchange resin and a strongly basic anion exchange resin is used, the mixing ratio of the strongly acidic cation exchange resin and the strongly basic anion exchange resin in the resin mixed bed is The volume ratio of the strongly acidic cation exchange resin in pure water is at least 10% or more, preferably 20% or more.

Furthermore, the method of the present invention can be carried out not only in a continuous system but also in a batch system. As an example of the continuous method, there is a method of continuously feeding and contacting hydrogen peroxide solution to a column filled with a strongly acidic cation exchange resin alone or a resin mixed bed of a strongly acidic cation exchange resin and a strongly basic anion exchange resin. Can be mentioned. In this case, the space velocity (hr ^-1 ) is not particularly limited, but preferably 1 to 1 with respect to the strongly acidic cation exchange resin or the strongly acidic cation exchange resin in the resin mixed bed.
It is preferably 1000, more preferably 10 to 600.

According to the method of the present invention, Al, Fe, Cr
Is a highly acidic cation exchange resin or a resin mixed bed of a strongly acidic cation exchange resin and a strongly basic anion exchange resin, and is treated with a hydrogen peroxide solution to which an acid has been added, to easily and extremely low concentration. To be removed. That is, in the conventional method in which an acid is not added, a partially weak cation form or weak anion form that cannot be sufficiently removed is formed, or metal components such as Al, Fe, and Cr that are not completely dissolved are almost completely removed. Can be thoroughly removed to the state.

This is because hydrogen peroxide purified by contacting with a strong acidic cation exchange resin alone contains almost no metallic impurities except for a very small amount of strong anionic metallic impurities, and strongly acidic cation exchange resins. When contacted with a resin mixed bed of an exchange resin and a strongly basic anion exchange resin, it means that almost no strong anionic metal-based impurities are present.

After the hydrogen peroxide solution of the present invention is contacted with the strong acid cation exchange resin alone, it is subsequently contacted with the strong base anion exchange resin alone or a mixed bed of the strong base anion exchange resin and the strong acid cation exchange resin. By the addition, the anion derived from the added acid and other anionic impurities can be removed.

Further, the method of the present invention has the following advantages. Compared to hydrogen peroxide solution obtained by conventional purification method, that is, purification method by contacting with strongly acidic cation exchange resin without adding acid, it was obtained by adding acid and contacting with strongly acidic cation exchange resin. Since there are fewer metallic impurities that accelerate the decomposition of hydrogen peroxide water in hydrogen peroxide water, the decomposition of hydrogen peroxide is possible even when it is subsequently contacted with the anion exchange resin alone or a mixed bed of anion exchange resin and cation exchange resin. Is sufficiently suppressed. As a result, it is possible to safely carry out purification using the anion exchange resin alone or a mixed bed of the cation exchange resin and the anion exchange resin.

Similarly, after a hydrogen peroxide solution is brought into contact with the mixed bed of the strongly acidic cation exchange resin and the strongly basic anion exchange resin in the present invention, the strongly acidic cation exchange resin alone or the strongly basic cation exchange resin is used as required. The anion exchange resin may be contacted alone. By the series of operations described above, metal impurities can be thoroughly and safely removed as compared with the conventional purification method.

[0029]

The present invention is described in detail below with reference to examples, but the present invention is not limited to these examples. In addition, the measurement of metallic impurities is performed by ICP-M.
The S (Inductive coupling-Mass spectrometry) method was used to measure the anionic impurities by the ion chromatography method.

Example 1 100 ml of a strong acid cation exchange resin (Amberlite 201B H type) manufactured by Organo Corporation was packed in a fluororesin column having a diameter of 2.6 cm. Sulfuric acid was added at 0.4 meq / l-H ₂ O ₂ and left at 15 to 20 ° C. for 24 hours. 3
A 1% hydrogen peroxide solution was passed through a strongly acidic cation exchange resin column at a space velocity (hr ^-1 ) of 500 to obtain a purified hydrogen peroxide solution. The metal impurity content before purification is Al: 150 p.
It was pb, Fe: 5 ppb, and Cr: 10 ppb. Table 1 shows the content of metal impurities after purification.

Example 2 Nitric acid was added in an amount of 0.4 meq / liter-H ₂ O ₂ and 3
Purification was performed in the same manner as in Example 1 except that 31% hydrogen peroxide solution that had been left for 0 hours was used to obtain purified hydrogen peroxide solution. Table 1 shows the content of metal impurities after purification.

Example 3 Nitric acid was added at 0.4 meq / liter-H ₂ O ₂ and 2
Purification was carried out in the same manner as in Example 1 except that 31% hydrogen peroxide water left for 4 hours was used to obtain purified hydrogen peroxide water. Table 1 shows the content of metal impurities after purification.

Example 4 Nitric acid was added at 0.4 meq / liter-H ₂ O ₂ and 3
Using a 31% hydrogen peroxide solution left for 6 hours, space velocity
Purification was performed in the same manner as in Example 1 except that the solution was passed through at (hr ^-1 ) 600 to obtain purified hydrogen peroxide solution. Table 1 shows the content of metal impurities after purification.

Example 5 Purified hydrogen peroxide solution was obtained in the same manner as in Example 1 except that 31% hydrogen peroxide solution containing sulfuric acid was used within 1 hour. Table 1 shows the content of metal impurities after purification.

Example 6 Nitric acid was added in an amount of 0.4 meq / liter-H ₂ O ₂ to give 6
Purification was performed in the same manner as in Example 1 except that 31% hydrogen peroxide solution that had been allowed to stand for a while was used to obtain purified hydrogen peroxide solution. Table 1 shows the content of metal impurities after purification.

[0036]

[Table 1]

Example 7 A strong acid cation exchange resin (Amberlite 201B H type) manufactured by Organo and a strong basic anion exchange resin (Amberlite IRA-900 bicarbonate type) manufactured by Organo were thoroughly mixed at a volume ratio of 1: 1. 100 ml of the resin mixed bed was packed in a fluororesin column having a diameter of 2.6 cm. Sulfuric acid was added to this in an amount of 0.4 meq / liter-H ₂ O ₂ , and 15 to _{2 was} added.
31% hydrogen peroxide water left at 0 ° C. for 24 hours was passed through the resin mixed bed at a space velocity (hr ⁻¹ ) of 250 to the column,
Purified hydrogen peroxide water was obtained. The amount of impurities before purification is Al: 1
50 ppb, Fe: 5 ppb, Cr: 10 ppb, SO
_{4: 20,000ppb,} PO _4: was 200ppb. Table 2 shows the content of impurities after purification.

Example 8 Nitric acid was added at 0.4 meq / liter-H ₂ O ₂ and 2
Purification was carried out in the same manner as in Example 7 except that 31% hydrogen peroxide water left for 4 hours was used to obtain purified hydrogen peroxide water. The amount of impurities before purification is Al: 150 ppb, Fe: 5 ppb, C
r: 10 ppb, NO ₃ : 25,000 ppb, PO
₄ : 200 ppb. Table 2 shows the content of impurities after purification.

Example 9 Similar to Example 8 except that the mixing ratio of the strongly acidic cation exchange resin and the strongly basic anion exchange resin in the resin mixed bed was 1: 9 and the space velocity (hr ^-1 ) was 50. Purification was performed to obtain purified hydrogen peroxide solution. Table 2 shows the content of impurities after purification.

Example 10 Purified peroxide was prepared in the same manner as in Example 8 except that a strong basic anion exchange resin (Amberlite IRA-900 hydroxide type) manufactured by Organo Corporation was used as the strong basic anion exchange resin. Hydrogen water was obtained. Table 2 shows the content of impurities after purification.

(The margin below)

[Table 2]

Example 11 Organo's strong basic anion exchange resin (IRA-90)
0 bicarbonate type was packed in a fluororesin column having a diameter of 2.6 cm in an amount of 100 ml. On the outflow side of the column, a generated gas meter was attached so that the amount of gas generated in the column could be quantified. The purified hydrogen peroxide solution obtained in Example 1 was passed through a strongly basic anion exchange resin column at a space velocity (hr ⁻¹ ) of 500 to obtain purified hydrogen peroxide solution. The anionic impurity content of the purified hydrogen peroxide water obtained in Example 1 was S
O ₄ : 20,000 ppb and PO ₄ : 200 ppb. The content of impurities after purification and the amount of decomposed gas generated by the contact between anion exchange resin and hydrogen peroxide solution during purification (volume of gas generated in 1 hour from 1 hour after the start of liquid flow per 1 ml of anion exchange resin) It shows in Table 3.

Example 12 Using the purified hydrogen peroxide solution obtained in Example 2, purification was carried out in the same manner as in Example 11 to obtain purified hydrogen peroxide. The anion impurity content of the purified hydrogen peroxide water obtained in Example 2 was NO ₃ : 25,000 ppb, SO ₄ : 50 pp.
b, PO _4: was 200ppb. Table 3 shows the content of impurities after purification and the amount of decomposition gas generated by the contact of the strongly basic anion exchange resin and hydrogen peroxide solution during purification.

Example 13 Strong acidic cation exchange resin (201B H
Type) and the company's strong basic anion exchange resin (IRA-90)
100 ml of a 2.6 cm diameter fluororesin column was charged with a mixed bed in which a volume ratio of 1 (0 bicarbonate type) was mixed. A gas generation meter was attached to the outflow side of the mixed bed column in the same manner as in Example 11 so that the amount of gas generated in the column could be measured. The purified hydrogen peroxide solution obtained in Example 3 was passed through the mixed bed column at a space velocity (hr ⁻¹ ) of 250 to obtain a purified hydrogen peroxide solution. The anionic impurity content of the purified hydrogen peroxide water obtained in Example 3 was NO ₃ : 2.
5,000 ppb, SO ₄ : 10 ppb, PO ₄ : 20
It was 0 ppb. Table 3 shows the content of impurities after purification and the amount of decomposition gas generated by the contact between the anion exchange resin and the hydrogen peroxide solution in the resin mixed bed at the time of purification.

Example 14 As the anion exchange resin, a strongly basic anion exchange resin (Amberlite IRA-900 hydroxide type) manufactured by Organo was used, and the purified hydrogen peroxide solution obtained in Example 4 was passed through. Others were purified in the same manner as in Example 11 to obtain purified hydrogen peroxide solution. The anion impurity content of the purified hydrogen peroxide water obtained in Example 4 was NO ₃ : 25,000 ppb,
It was SO ₄ : 10 ppb and PO ₄ : 200 ppb.
Table 3 shows the content of impurities after purification and the amount of decomposition gas generated by the contact between the anion exchange resin and hydrogen peroxide solution during purification.

Example 15 Purified hydrogen peroxide solution was obtained by passing through the strongly basic anion exchange resin column in the same manner as in Example 11 except that the purified hydrogen peroxide solution obtained in Example 5 was used. The anionic impurity content of the purified hydrogen peroxide water obtained in Example 5 was SO ₄ :
It was 20,000 ppb and PO ₄ : 200 ppb.
Table 3 shows the content of impurities after purification and the amount of decomposition gas generated by the contact between the anion exchange resin and hydrogen peroxide solution during purification.

[0047]

[Table 3]

Example 16 A strong acidic cation exchange resin (Amberlite 201B H type) manufactured by Organo Co., and a strongly basic anion exchange resin (Amberlite IRA-900 bicarbonate type) manufactured by Organo Co. were thoroughly mixed at a volume ratio of 1: 1. 100 ml of each of the resin mixed bed and the strongly basic anion exchange resin (same bicarbonate type) were packed in a fluororesin column having a diameter of 2.6 cm. To this, add nitric acid 0.4 milliequivalent / liter-H ₂ O _{2, and} add 36
The 31% hydrogen peroxide solution left for a while was passed through the resin mixed bed and the strongly basic anion exchange resin in this order at each space velocity (hr ⁻¹ ) of 250 and 500 to obtain purified hydrogen peroxide solution. It was The amount of impurities before purification is Al: 150 pp
b, Fe: 5 ppb, Cr: 10 ppb, NO ₃ : 2:
It was 5,000 ppb and PO ₄ : 200 ppb. Table 4 shows the content of impurities after purification.

Example 17 A strong acid cation exchange resin (Amberlite 201B H type) manufactured by Organo Co., and a strong basic anion exchange resin (Amberlite IRA-900 bicarbonate type) manufactured by Organo Co. were fully mixed at a volume ratio of 1: 1. 100 ml of each of the resin mixed bed and the strongly acidic cation exchange resin were packed in a fluororesin column having a diameter of 2.6 cm. 0.4 milliequivalent / liter-H ₂ O _{2 was} added to this and left for 24 hours.
Space velocity (hr ^-1 ) 2 of 1% hydrogen peroxide solution for each column in the order of resin mixed bed and strongly acidic cation exchange resin
The solution was passed at 50 and 500 to obtain purified hydrogen peroxide solution. The amount of impurities before purification is Al: 150 ppb, Fe: 5 ppb,
Cr: 10 ppb, NO ₃ : 25,000 ppb, PO
₄ : 200 ppb. Table 4 shows the content of impurities after purification.

Comparative Example 1 A purified hydrogen peroxide solution was obtained in the same manner as in Example 1 except that hydrogen peroxide solution containing no acid was used. Table 5 shows the content of metal impurities after purification.

Comparative Example 2 Purified hydrogen peroxide solution was obtained in the same manner as in Example 4 except that hydrogen peroxide solution containing no acid was used. Table 5 shows the content of metal impurities after purification.

(Hereinafter, margin)

[Table 4]

[0053]

[Table 5]

Comparative Example 3 Purified hydrogen peroxide solution was obtained in the same manner as in Example 7 except that hydrogen peroxide solution containing no acid was used. The amount of impurities before purification is Al: 150 ppb, Fe: 5 ppb, Cr: 1.
It was 0 ppb and PO ₄ : 200 ppb. Table 6 shows the content of impurities after purification.

Comparative Example 4 Similar to Example 9 except that the mixing ratio of the strongly acidic cation exchange resin and the strongly basic anion exchange resin in the resin mixed bed was 1:19 and the space velocity (hr ⁻¹ ) was 25. Purification was performed to obtain purified hydrogen peroxide solution. Table 6 shows the content of impurities after purification.

Comparative Example 5 Purified hydrogen peroxide solution was obtained in the same manner as in Example 1 except that a weakly acidic cation exchange resin (Amberlite IRC-50 H type) manufactured by Organo Corporation was used as the cation exchange resin. . Table 6 shows the metal impurity content after purification.

Comparative Example 6 Instead of the strong acid cation exchange resin, a strong basic anion exchange resin (IRA-900 hydroxide type) manufactured by Organo Corporation.
Was purified in the same manner as in Example 1 to obtain purified hydrogen peroxide solution. Table 6 shows the metal impurity content after purification.

Comparative Example 7 Purification was carried out in the same manner as in Example 7 except that a column consisting of a strongly basic anion exchange resin (bicarbonate type) was used and the space velocity (hr ^-1 ) was set to 500. Hydrogen peroxide water was obtained. Table 6 shows the content of inorganic impurities after purification.

[0059]

[Table 6]

Comparative Example 8 Purified hydrogen peroxide solution was obtained in the same manner as in Example 11 except that the purified hydrogen peroxide solution obtained in Comparative Example 1 was used. The anion impurity contents of the purified hydrogen peroxide water obtained in Comparative Example 1 were SO ₄ : 10 ppb and PO ₄ : 200 ppb. Table 7 shows the content of impurities after purification and the amount of decomposition gas generated by the contact between the anion exchange resin and hydrogen peroxide solution during purification.

Comparative Example 9 Purified hydrogen peroxide solution was obtained in the same manner as in Example 13 except that the purified hydrogen peroxide solution obtained in Comparative Example 1 was used. Table 7 shows the content of impurities after purification and the amount of decomposition gas generated by the contact between the anion exchange resin and the hydrogen peroxide solution in the resin mixed bed at the time of purification.

Comparative Example 10 The purified hydrogen peroxide solution obtained in Comparative Example 1 was mixed with 0.4 ml of sulfuric acid.
Reequivalent / L-H ₂O₂ Add strong basic anion
Purification in the same manner as in Example 11 except that the solution was passed through the exchange resin column.
Then, purified hydrogen peroxide water was obtained. Purification obtained in Comparative Example 1
Containing anionic impurities after adding sulfuric acid to hydrogen peroxide water
The amount is SO_Four : 20,000ppb, PO_Four : 200p
It was pb. Impurity content after purification and
Emission of decomposition gas due to contact between Nion exchange resin and hydrogen peroxide solution
The yield is shown in Table 7.

Comparative Example 11 Purified hydrogen peroxide solution was obtained in the same manner as in Example 14 except that the purified hydrogen peroxide solution obtained in Comparative Example 2 was used. The content of anion impurities in the purified hydrogen peroxide water obtained in Comparative Example 2 was SO ₄ : 10 ppb and PO ₄ : 200 ppb. Table 7 shows the content of impurities after purification and the amount of decomposition gas generated by the contact between the anion exchange resin and hydrogen peroxide solution during purification.

Comparative Example 12 Purified hydrogen peroxide solution was obtained in the same manner as in Example 11 except that the purified hydrogen peroxide solution obtained in Comparative Example 5 was used. The purified hydrogen peroxide water obtained in Comparative Example 5 contained SO ₄ : 20,000 ppb and PO ₄ : 200.
It was ppb. Table 7 shows the content of impurities after purification and the amount of decomposition gas generated by the contact between the anion exchange resin and hydrogen peroxide solution during purification.

[0065]

[Table 7]

Comparative Example 13 Example 16 except that hydrogen peroxide solution containing no acid was used.
Purification was carried out in the same manner as above to obtain purified hydrogen peroxide solution. Table 8 shows the content of impurities after purification.

Comparative Example 14 Example 17 except that hydrogen peroxide solution containing no acid was used.
Purification was carried out in the same manner as above to obtain purified hydrogen peroxide solution. Table 8 shows the content of impurities after purification.

[0068]

[Table 8]

[0069]

According to the present invention, metal impurities such as Al, Fe, and Cr in hydrogen peroxide, which are difficult to remove by the conventional method, are removed to a low concentration of 2 ppb or less, or even 1 ppb or less. Hydrogen peroxide water of high purity can be manufactured safely and efficiently by sufficiently suppressing the decomposition of hydrogen peroxide.

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[Procedure amendment]

[Submission date] June 28, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 3

[Correction method] Change

[Correction content]

Claims (5)

[Claims] 1. When purifying hydrogen peroxide solution, an acid having an acid dissociation index pKa of 5 or less at 25 ° C. in water is added to hydrogen peroxide solution in an amount of 0.005 to 5 milliequivalents per 1 liter of hydrogen peroxide solution. Then, a method for purifying hydrogen peroxide water, which comprises contacting with a H-type strongly acidic cation exchange resin having a sulfonic acid group. 2. When purifying hydrogen peroxide water, an acid having an acid dissociation index pKa of 5 or less at 25 ° C. in water is added to hydrogen peroxide water in an amount of 0.005 to 5 milliequivalents per liter of hydrogen peroxide water. Then, a method for purifying hydrogen peroxide water, which comprises contacting with a mixed bed of an H-type strongly acidic cation exchange resin having a sulfonic acid group and a strongly basic anion exchange resin. 3. The strongly basic anion exchange resin has at least one ion selected from the group consisting of hydroxide ion, carbonate ion and bicarbonate ion in its structure. 2. The method for purifying hydrogen peroxide water according to 2. 4. The hydrogen peroxide according to claim 2, wherein the ratio of the H-type strongly acidic cation exchange resin having a sulfonic acid group in the mixed bed is 10% or more by volume in pure water. Water purification method. 5. A method in which an acid having an acid dissociation index pKa of 5 or less at 25 ° C. in water is added to hydrogen peroxide water, and then the hydrogen peroxide water aged for 6 hours or more is brought into contact with an ion exchange resin. The method for purifying hydrogen peroxide water according to claim 1 or 2, characterized in that.