JP2003146946A - Method for producing solution of hydrogen peroxidized quaternary ammonium salt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a hydrogen peroxidized quaternary ammonium salt useful for reduction of a titanium oxide. SOLUTION: One or more kinds of an acid having oxidation-reduction capabilities, selected from the group comprising an inorganic acid such as nitrous acid, sulfurous acid, sulfuric acid, persulfuric acid, phosphorous acid, hypophosphorous acid and perboric acid, and an organic acid such as ascorbic acid, oxalic acid and citric acid, and/or a salt thereof are added to the solution of the hydrogen peroxidized quaternary ammonium salt.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a hydrogen peroxide solution of a quaternary ammonium salt. This hydrogenated quaternary ammonium salt solution is used as a reducing agent for titanium oxide.

[0002]

2. Description of the Related Art A hydrogenated quaternary ammonium salt is a quaternary ammonium salt coordinated with hydrogen peroxide. By coordinating hydrogen peroxide with a quaternary ammonium salt, the properties of hydrogen peroxide change significantly, making it easier to handle, such as not decomposing even when it contacts platinum.

The hydrogen peroxide solution of the quaternary ammonium salt is used as a reducing agent for titanium oxide, particularly as a reducing agent for titanium oxide under alkaline conditions.

Such reduction of titanium oxide is carried out, for example, by
In the production of semiconductors using titanium, it is useful for exfoliation of titanium oxide existing as a by-product (Japanese Patent Laid-Open No. 4-289866). Note that in the manufacture of semiconductors, materials other than titanium are used, and many materials are damaged under strong alkaline. Therefore, it is necessary to adjust the pH to a certain level (weakly alkaline). In addition to semiconductor manufacturing, strongly alkaline substances have a strong influence on the human body and the like, which is problematic in handling.

By the way, the hydrogen peroxide solution of the quaternary ammonium salt is effective for the reduction of titanium oxide under strong alkalinity, but as the pH is lowered (that is, weaker alkalinity), it gradually becomes smaller. However, there was no known method for adjusting the pH of the quaternary ammonium salt solution of hydrogen peroxide while maintaining the reducing power of titanium oxide. .

Therefore, there has been a demand for a method for producing a hydrogenated quaternary ammonium salt solution whose pH can be adjusted.

[0007]

DISCLOSURE OF THE INVENTION The object of the present invention is to
It is to provide a method for producing a hydrogenated quaternary ammonium salt solution.

[0008]

Means for Solving the Problems The inventors of the present invention have made extensive studies as to a method for producing a hydrogenated quaternary ammonium salt solution whose pH can be adjusted. As a result, an acid having a redox property and / or its acid can be obtained. It was found that the pH can be adjusted by using a salt without deteriorating the performance of the quaternary ammonium salt solution of hydrogen peroxide, and the present invention has been completed.

That is, the present invention is characterized by adding a redox acid and / or a salt thereof to a quaternary ammonium salt hydrogen peroxide solution. It relates to a method for producing a solution.

The present invention will be described in more detail below.

In the method of the present invention, the hydrogen peroxide of the quaternary ammonium salt means, like water in crystallization water,
It means a quaternary ammonium salt coordinated with hydrogen peroxide. Hydrogen peroxide coordinates to various compounds to form hydrogen peroxide. Other known forms of hydrogen peroxide include potassium fluoride, rubidium carbonate, and urea. It is presumed that the hydrogenated quaternary ammonium salt of the present invention has a structure similar to these.

A hydrogen peroxide solution of a quaternary ammonium salt is used as a reducing agent for titanium oxide. Particularly, it is used as a reducing agent for titanium oxide under alkaline conditions.
Such reduction of titanium oxide is useful, for example, in the production of semiconductors using titanium, for exfoliation of titanium oxide existing as a by-product, and the like. Note that in the manufacture of semiconductors, materials other than titanium are used, and many materials are damaged under strong alkaline. Therefore, it is necessary to adjust the pH to a certain level (weakly alkaline).
In addition to semiconductor manufacturing, strongly alkaline substances have a strong influence on the human body and the like, which is problematic in handling. For this reason,
There is a need to prepare a hydrogenated quaternary ammonium salt solution with adjustable pH.

In the production method of the present invention, a solution of a quaternary ammonium salt in a hydrogen peroxide solution is mixed with an acid having a redox property and / or
Alternatively, it is characterized by adding a salt thereof. The redox acid is preferably at least one selected from the group consisting of inorganic acids, organic peracids and organic acids. Examples of the inorganic acid include nitrous acid, sulfurous acid, sulfuric acid, persulfuric acid, phosphorous acid, hypophosphorous acid, and perboric acid.
One or more of these may be used.

As the organic peracid, for example, perbenzoic acid,
Examples thereof include peracetic acid, and one or more of these may be used.

As the organic acid, for example, ascorbic acid, oxalic acid, citric acid and the like can be exemplified, and at least one of them may be used. Among these, nitrous acid, phosphorous acid, sulfuric acid, and persulfuric acid, which are particularly excellent in resist stripping performance and titanium oxide stripping performance, are preferable.

Furthermore, salts of these acids can also be used.

In the production method of the present invention, a redox acid and / or a salt thereof is added to a hydrogen peroxide solution of a quaternary ammonium salt, but other non-redox acids, salts, and There is no problem even if the base is added at the same time. Further, after adding an acid and / or salt having a redox property, even if an acid, a salt or a base having no redox property is added, on the contrary, after adding an acid, a salt or a base having no redox property, An acid and / or salt having a redox property may be added.

In the production method of the present invention, the quaternary ammonium salt hydrogen peroxide solution is heated and mixed with the quaternary ammonium salt and aqueous hydrogen peroxide, or in the presence of a catalyst such as phthalic acid. It can be obtained. The quaternary ammonium salt used in the present invention comprises a quaternary ammonium cation and an anion.

There is no particular limitation on the type of anion forming the quaternary ammonium salt. Examples of preferable ions include carbonate ion, carboxylate ion, and hydroxide ion. As the carboxylate ion, either an aliphatic carboxylate ion or an aromatic carboxylate ion can be used. One kind of these anions may be used, or two or more kinds may be present.

In addition to the above, anions generated from the redox acid added in the present invention, that is, nitrite ion, sulfite ion, sulfate ion, persulfate ion, phosphite ion, hypophosphite ion, perboric acid. Inorganic acid ions such as ions, perbenzoic acid ions, organic peracid ions such as peracetic acid ions, ascorbate ions, oxalate ions, citrate ions and the like can also be used.

The quaternary ammonium cation forming the quaternary ammonium salt is not particularly limited, and examples thereof include relatively inexpensive tetramethylammonium cation, tetraethylammonium cation, tetrapropylammonium cation, ethyltrimethylammonium cation,
Tetraalkylammonium cations such as triethylmethylammonium cation, octyltrimethylammonium cation, decyltrimethylammonium cation, dodecyltrimethylammonium cation, benzyltrialkylammonium cation such as benzyltrimethylammonium cation, hydroxyalkyltrialkylammonium such as hydroxyethyltrimethylammonium cation Cation etc. can be mentioned.

In the production method of the present invention, the solvent used is most preferably water. Cheapest, hydrogen peroxide,
Most of the quaternary ammonium salts are distributed as an aqueous solution, which is industrially advantageous. However, it is perfectly acceptable to add a solvent such as a quaternary ammonium salt, hydrogen peroxide, or an alcohol capable of dissolving an aromatic carboxylic acid.

In the production method of the present invention, a stabilizer for hydrogen peroxide may be added. The stabilizer may be added to the raw material before producing the hydrogen peroxide, or may be added after producing the hydrogen peroxide. Examples of hydrogen peroxide stabilizers include salicylic acid, aniline, acetanilide, and hindered amines. These may be used singly or in combination of two or more kinds.

In the production method of the present invention, a solution of a quaternary ammonium salt in a hydrogen peroxide is used in Japanese Patent Application No. 2001-336.
It can be analyzed by liquid chromatography (LC) according to No. 140. When analyzed by LC, it is possible to separate the quaternary ammonium salt that has not become a hydrogen peroxide and the quaternary ammonium salt that has become a hydrogen peroxide by the production method of the present invention. The separating agent is usually one packed in a column.

If a column for gel filtration (GPC) is used as the column, analysis can be performed with high resolution. Among them, it is preferable to use a column packed with a vinyl polymer-based filler, and a polar organic solvent column is more preferable. It is preferable to use an aqueous solution containing acetonitrile as an eluent for LC. The ratio of water to acetonitrile differs depending on the compounds to be separated, so it cannot be determined unconditionally. Water is added to increase the polarity of the eluent, and acetonitrile is increased to decrease the polarity of the eluent. The ratio can be freely changed in consideration of the peak shape and the separability.

The hydrogen peroxide solution of the quaternary ammonium salt obtained according to the production method of the present invention can reduce titanium oxide, but in the production of semiconductors,
It can be used as a raw material for a resist or a resist residue remover. Further, water, a water-soluble organic solvent, amines, and a corrosion inhibitor may be added to improve the releasability of the polymer and the polymer residue.

[0027]

EXAMPLES The present invention will be described in more detail with reference to the following examples, which should not be construed as limiting the invention thereto.

The hydrogen peroxide was analyzed by liquid chromatography. A gel filtration column was used as the column, and an aqueous solution containing acetonitrile was used as the eluent.

Production Example (Production of Hydrogen Peroxide of Quaternary Ammonium Salt) 25% of tetramethylammonium hydroxide at room temperature
Phthalic acid 18.2 in 100 g (0.275 mol) of aqueous solution
g (0.110 mol) was added. While further stirring, 45.4 g (0.401 mol) of 30% hydrogen peroxide aqueous solution
Was added dropwise over 2 hours. After completion of dropping, stirring was continued for 1 hour. When the aqueous solution was analyzed by liquid chromatography, 97% of the quaternary ammonium salt was hydrogen peroxide. When the pH of this aqueous solution was measured at 25 ° C., it was 13.8. This aqueous solution is referred to as aqueous solution A.

Example 1 Aqueous nitrite was added little by little to aqueous solution A to adjust the pH to 10.2. This 10% aqueous solution was analyzed for anodic polarization curve at 50 ° C. to examine the reducibility of titanium oxide. The anodic polarization curve analysis is to put an aqueous solution into a cell divided into two chambers by a glass filter, put a titanium piece with an oxide film on the surface on one side and a platinum piece on the other side, and apply an anodic potential to the metal at that time. The melting current of is measured. By anodic polarization curve analysis, it was confirmed that titanium oxide was reduced and dissolved in this aqueous solution.

Comparative Example 1 Phthalic acid was added little by little to the aqueous solution A to adjust the pH to 10.2. The anodic polarization curve analysis was performed in the same manner as in Example 1, but no reducibility of titanium oxide was observed.

Comparative Example 2 Nitric acid was added little by little to the aqueous solution A to adjust the pH to 10.2. The anodic polarization curve analysis was performed in the same manner as in Example 1, but no reducibility of titanium oxide was observed.

Example 2 Nitric acid was added little by little to the aqueous solution A to adjust the pH to 12.4, and then nitrous acid was further added to adjust the pH to 10.2. As a result of performing the anodic polarization curve analysis in the same manner as in Example 1, the reducibility of titanium oxide was confirmed.

Examples 3 to 7 and Comparative Examples 3 to 5 The acid or salt shown in Table 1 was added to the aqueous solution A to adjust the pH shown in Table 1. Using this solution, the reducibility of titanium oxide was examined in the same manner as in Example 1.

Further, the aluminum piece whose surface was polished was immersed in an aqueous solution at 50 ° C. for 2 hours, and the weight loss and surface observation were used to examine the corrosiveness of aluminum.

The following symbols are used in Table 1 for the purpose of simply describing the results.

Titanium oxide reducing property ◯: Good reducibility Δ: Some reducibility is observed ×: No reducing property Aluminum corrosive ○: Small corrosiveness △: Some corrosion ×: There is severe corrosion

[0038]

[Table 1]

According to the production method of the present invention, there is provided a hydrogenated quaternary ammonium salt solution whose pH can be adjusted.

Claims (7)

[Claims] 1. A method for producing a quaternary ammonium salt hydrogen peroxide solution, which comprises adding a redox acid and / or a salt thereof to a quaternary ammonium salt hydrogen peroxide solution. Method. 2. The production method according to claim 1, wherein the redox acid is at least one selected from the group consisting of an inorganic acid, an organic peracid, and an organic acid. 3. The method according to claim 2, wherein the inorganic acid is at least one selected from the group consisting of nitrous acid, sulfurous acid, sulfuric acid, persulfuric acid, phosphorous acid, hypophosphorous acid and perboric acid. . 4. The production method according to claim 2, wherein the organic peracid is perbenzoic acid and / or peracetic acid. 5. The production method according to claim 2, wherein the organic acid is at least one selected from the group consisting of ascorbic acid, oxalic acid and citric acid. 6. The anion forming a quaternary ammonium salt is at least one selected from the group consisting of carbonate ion, carboxylate ion and hydroxide ion.
6. The manufacturing method according to any one of to 5. 7. The cation forming a quaternary ammonium salt is at least one selected from the group consisting of tetraalkylammonium ion, trialkylbenzylammonium ion and hydroxyalkyltrialkylammonium ion. The manufacturing method according to any one.