JPS62252319A - Production of high-purity titanium oxide film - Google Patents

Abstract

PURPOSE:To produce an extremely high-purity titanium oxide film, simply by thermal decomposition without requiring a decomposition agent, by sticking a condensed viscous solution of an aqueous solution of titanium or an alkoxytitanium peroxyhydrate onto a solid, drying the resultant solid film and heating the dried film. CONSTITUTION:Although an aqueous solution of titanium peroxyhydrate or aqueous solution of an alkoxytitanium peroxyhydrate or both are metastable at a cold temperature, free hydrogen peroxide is initially decomposed above room temperature to release a large volume of oxygen gas. The titanium peroxyhydrate with a high peroxyhydrate content is simultaneously converted into titanium peroxyhydrate with a low peroxyhydrate content and condensation is then initiated to gradually increase consistency and form a jelly-like substance. The viscous liquid is then applied onto a solid and air-dried at ordinary temperature to form a homogeneous solid coat, which is gradually heated to >=450 deg.C to give an amorphous titanium oxide film. The resultant film becomes a crystalline titanium oxide film by further heating to >=600 deg.C. This method is carried out simply by thermal decomposition without generating impurities from the individual raw material and requiring addition of a decomposing agent. Thereby the contamination by the impurities is avoided to afford the aimed extremely high-purity product.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for producing a high purity titanium oxide film.

Prior Art Conventional methods for producing titanium hydroxide or titanium oxide include:
A method of hydrolyzing or oxidizing a titanium salt such as titanium chloride, titanium sulfate, or alkoxytitanium as a raw material, or a combination of both is known. According to these methods, components that cause impurities, such as sulfuric acid, hydrochloric acid, chlorine, or alcohol, are present in the production of titanium hydroxide or titanium oxide. Therefore, these substances were incorporated into the product and made the titanium hydroxide or titanium oxide impure. The method for forming a titanium oxide film is to dissolve alkoxytitanium in a non-aqueous solvent such as alcohol to form a solution, adhere it to a solid, and then gradually hydrolyze it with water in a low-humidity atmosphere. There is a known method for forming a film. However, according to this method, in order to moderate the rate of hydrolysis, it is necessary to use a material with a large alkyl group, and the non-volatility of the alkyl component is large in the case of a material with a large alkyl group, which results in organic components remaining in the film. This had the disadvantage that it resulted in an impure titanium oxide film.

OBJECTS OF THE INVENTION The present invention was carried out in order to eliminate the drawbacks of conventional methods, and its purpose is to provide a method that can easily produce a titanium oxide film of extremely high purity.

Structure of the Invention As a result of research to achieve the above object, the present inventors have discovered that a viscous liquid obtained by condensing an aqueous titanium hydrogen peroxide solution, an aqueous alkoxytitanium hydrogen peroxide solution, or a cough liquid is deposited on a solid. After that, it was air-dried to form a solid film.Finally, it was found that a high-purity titanium oxide film could be easily obtained by heating the acid film to 450°C or higher. The present invention was completed based on this knowledge.

Summary of the present invention A viscous liquid or jelly obtained by condensing an aqueous titanium hydrogen peroxide solution or a viscous liquid or jelly obtained by condensing an aqueous alkoxy titanium peroxide solution is deposited on a solid, and then dried. This is a method for producing a high-purity titanium oxide film, which is characterized by forming a solid film by heating the acid film and gradually raising the temperature of the acid film to 450° C. or higher.

First, an aqueous titanium peroxide solution is produced by one of the following three methods. One is to cause a dissolution reaction between titanium hydride and aqueous hydrogen peroxide, and at this time, titanium hydride also catalyzes the decomposition reaction of hydrogen peroxide and the condensation reaction of the aqueous titanium peroxide solution. and promotes re-reaction. In order to speed up and give priority to the dissolution reaction,
Using commonly available bulk titanium hydride in a non-oxidizing atmosphere,
For example, it is necessary to grind it in water and use it as a fine powder. Hydrogen peroxide can be dissolved with 1% or more, but the higher the concentration, the faster the dissolution rate. Second, it is preferable that the alkoxy titanium used in the present invention be substituted with hydrogen oxide water so that the alcohol produced is highly volatile, such as methoxy titanium.

There are ethoxy titanium and propoxy titanium. However, in some cases, alkoxy titanium having a larger number of carbon atoms may be used. Alkoxytitanium is mixed with pure hydrogen peroxide solution to cause a dissolution reaction to produce an aqueous alkoxytitanium peroxide solution.

At this time, in order to avoid hydrolysis of alkoxytitanium due to moisture in the hydrogen peroxide solution, the concentration of hydrogen peroxide is preferably as high as 0.1% or more.

Preferably about 30%, and since decomposition of hydrogen peroxide and alkoxy titanium peroxide occurs at high temperatures, in order to suppress the temperature rise due to reaction heat, pure water is heated to 50"C or lower, preferably while cooling with ice water It is necessary to mix and dissolve the hydrogen peroxide solution.When the aqueous alkoxy titanium peroxide solution obtained by this method is reduced in pressure to 10-2 to 10-3 torr using, for example, an oil rotary pump, hydrogen peroxide is dissolved. The liberated alcohol and some alcohol oxidation products such as ketones or aldehydes are distilled off together with water and free hydrogen peroxide to produce a pure aqueous titanium peroxide solution.

The obtained aqueous solutions of alkoxytitanium hydrogen peroxide and titanium hydrogen peroxide are metastable at cold temperatures;
First, free hydrogen peroxide is decomposed to release a large amount of oxygen gas. At the same time, high hydrogen peroxide titanium changes to low hydrogen peroxide titanium, and the orange color tone becomes lighter over time, followed by condensation of low hydrogen peroxide titanium, gradually increasing the degree of condensation, and increasing the viscosity. The consistency increases and becomes jelly-like. Generally, at room temperature, it will last for several hours to several days.
Alternatively, this state continues for several minutes to several hours at 100°C.

Depositing a viscous liquid onto a solid. Alternatively, an aqueous solution of alkoxytitanium hydrogen peroxide and an aqueous titanium hydrogen peroxide solution may be deposited on a solid, where it becomes viscous, and when this is air-dried at room temperature, a uniform solid film is formed. When the temperature is gradually raised to 450° C. or higher, an amorphous titanium oxide film is obtained. Further heating to 600° C. or higher turns the film into a crystalline titanium oxide film.

Effects of the Invention According to the method of the present invention, an aqueous titanium peroxide solution or a condensate thereof is used as a raw material for producing a high-purity titanium oxide film, so it does not contain any elements other than titanium, hydrogen, and oxygen. Unlike conventional methods, impurities are not generated from the raw material itself, and there is no need to add additives to the raw material, just thermal decomposition is required, so contamination with impurities can be avoided and titanium oxide of extremely high purity can be produced. A membrane is obtained.

In addition, the raw material is water-based and easy to handle.

Further, if titanium oxide is allowed to contain a small amount of carbon, an aqueous solution of alkoxytitanium peroxide using alkoxytitanium with a small molecular weight, ie, methoxytitanium, ethoxytitanium, or propoxytitanium, can be used as is.

Example 1) Put 2 grams of titanium tetraisopropoxy into a beaker, cool the beaker by immersing it in ice water, add 8 ml of 30% high purity hydrogen peroxide solution, and gradually stir. After making a homogeneous tangerine-colored aqueous solution of isopropoxy titanium hydrogen peroxide, add 500 ml of pure water to dilute it, filter it just to make sure there are no undissolved substances, and add this solution. Pour into a flat-bottomed glass container to a depth of 5CI11 and leave it indoors at room temperature to gradually promote condensation of water vapor and solute, resulting in a slightly yellow color of 5CI/cd.
A membrane was produced.

This film was peeled off from a flat-bottomed glass container and exposed to air.
The temperature was raised to 700°C at a rate of 5°C per minute to obtain a colorless anatase-type titanium oxide film.

Example 2) A block of titanium hydride was crushed in a mortar while soaked in a small amount of water, and 47 cm of the fine powder was mixed into 10 m1 of 3
Add to 0% high-purity hydrogen peroxide solution, mix, and dissolve after a while to obtain a yellow titanium hydrogen peroxide aqueous solution.
After diluting this solution with 100 ml of pure water, put this solution into a flat-bottomed glass container to a depth of 2CIL1 and leave it in a room at room temperature to gradually promote evaporation of water and condensation of solute. A pale yellow film was produced. This film was peeled off from the flat-bottomed glass container and heated to 700°C at a rate of 5°C per minute in air to obtain a colorless anatase titanium oxide film.

Procedural amendment Month 27th in 1986 1985 Patent Application No. 93580 2. Name of the invention Manufacturing method of high purity titanium oxide film 3. Person who makes corrections Relationship to the incident: Patent applicant 5. Number of inventions increased by amendment None 6. Subject of amendment Detailed description of the invention in the specification 7. Contents of correction As per attached sheet Attachment (1) Page 2 of the specification, line 2, “sulfuric acid, hydrochloric acid” has been replaced with “sulfate.”

Chloride” is corrected.

(2) On page 2, lines 12 and 13, "alkyl group" is corrected to "alkoxyl group."

(3) Replace “alkyl content” with “alcohol” on page 2, line 13.
I am corrected.

(4) On page 3, line 4, "acid solution" is corrected to "both solutions."

(5) On page 3, line 9, "based on" is corrected to "based on".

(6) "Hydrogen peroxide solution" in the last line of the third page of the same page is corrected to "hydrogen peroxide solution."

(7) Page 4, line 2, “Titanium hydrogen peroxide aqueous solution” is changed to “
"Titanium hydrogen peroxide" is corrected.

(8) On page 4, line 7, "1%" is corrected to "0.1%."

(9) On page 4, line 9, "hydrogen oxide water" is corrected to "hydrogen peroxide."

(10) On page 4, line 10, ``wa'' is corrected to ``ga''.

(11) On page 4, line 13, ``large'' is corrected to ``large''.

(12) On page 4, line 15, "pure hydrogen peroxide solution" is corrected to "hydrogen peroxide solution."

(13) Correct ``Hydrogen peroxide solution'' in the fourth line from the bottom to ``Hydrogen peroxide solution.''

(14) Page 5, lines 1-2 “Hydrogen water and...
・Correct ``because it hurts'' as follows.

"Because decomposition of hydrogen and alkoxytitanium hydrogen peroxide occurs violently." (15) On page 5, line 4, "pure hydrogen peroxide solution" is corrected to "hydrogen peroxide solution."

(16) Delete "Jun" on page 5, line 11 of the same page.

(17) Insert the following sentence between lines 12 and 13 on page 5.

``The aqueous hydrogen peroxide solution used in the present invention may be a commercially available product, but there are various purity products, and the most preferred is the highest purity product that does not contain stabilizers, but it is not limited to this. (18) In the 6th line from the bottom of the 5th line, add ``Above room temperature'' next to ``Aruga''.

(19) On page 6, line 5, "and" is corrected to "or."

(20) Add "no" next to "as a raw material" in line 7 from the bottom of No. 6.

(21) Delete the ``wa'' in the 6th line from the bottom of the 6th line.

(22) In the 6th line from the bottom, ``additive'' is corrected to ``decomposer.''

(23) On page 7, line 11, "hydrogen water" is corrected to "hydrogen aqueous solution."

(24) On the 7th page, line 5 from the bottom, ``steam'' is corrected to ``evaporation''.

(25) On page 8, line 5, "hydrogen peroxide solution" is corrected to "hydrogen peroxide solution."

(26) On page 8, line 7, "hydrogen" is corrected to "hydrogenation."

Claims (1)

[Claims] After depositing an aqueous titanium hydrogen peroxide solution, an aqueous alkoxy titanium peroxide solution, or a viscous liquid obtained by condensing the two liquids on a solid, it is dried to form a solid film,
A method for producing a high-purity titanium oxide film, which comprises gradually raising the temperature of the film to 450°C or higher.