JP3372435B2 - Method for producing titanium oxide film - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a titanium oxide film, which comprises utilizing a precipitation phenomenon in an aqueous solution to bring a titanium oxide-containing solution into contact with a substrate to form a titanium oxide film on the surface of the substrate. It is about.

[0002]

2. Description of the Related Art A titanium oxide film, a silicon oxide film, or a composite film of titanium oxide and silicon oxide is used as an alkali metal diffusion preventing film of glass containing an alkali metal such as sodium, an insulating film in a semiconductor device, a photocatalyst film, or the like. It has been done. Conventionally, when forming the above coating film on the surface of a substrate such as glass, a vapor phase method is a CVD method or a PVD method.
As the liquid phase method, a dip coating method by a sol-gel method or a spin coating method is adopted.

Further, a method of forming a silicon oxide film from an aqueous solution is disclosed in, for example, JP-A-57-196744, JP-A-64-28376, and JP-A-64-28377. In these publications, boric acid or aluminum is added to a saturated aqueous solution of hydrosilicofluoric acid to prepare a silicon oxide-containing solution, and the solution is brought into contact with a substrate to form a silicon oxide film on the surface of the substrate. Is formed.

Further, a method of forming a titanium oxide film from an aqueous solution is disclosed in, for example, Japanese Patent Application Laid-Open No. 3-285822. This publication describes that boric acid is added to an aqueous solution of ammonium fluorotitanate to prepare a titanium oxide-containing solution, and the solution is brought into contact with a substrate to form a titanium oxide film on the surface of the substrate. ing.

[0005]

However, the CVD method or PV
The method D requires the use of expensive equipment and batch processing in a vacuum, which raises the problem of high manufacturing cost, and further reduces the size of the substrate to relatively less unevenness. There was a problem that it could only be applied.

In the dip coating method and the spin coating method by the sol-gel method, a film can be formed only on a flat substrate, and since an organic solvent is used, there is a risk of fire or explosion, Further, since a large amount of organic matter remains in the coating film, there is a problem that treatment at high temperature is required to remove this. Further, the above method of forming a film using a saturated aqueous solution of hydrosilicofluoric acid has a problem that it takes time and cost to prepare a saturated silica solution and filter the solution.

Further, the above method of forming a coating film using an aqueous solution of ammonium fluorotitanate has the problems that the adhesion between the titanium oxide coating film and the substrate is low and the hardness of the titanium oxide coating film is small. There is a problem that heat treatment at 300 ° C. or higher is required to improve the above, and heat treatment at 500 ° C. or higher is required to obtain a coating having particularly high hardness.

The present invention has been made in view of the above points, and it is possible to reduce the manufacturing cost and the risk, to reduce the restrictions on the base material, and to perform the heat treatment without the heat treatment. It is an object of the present invention to provide a method for producing a titanium oxide coating capable of forming a titanium oxide coating having high adhesion with a material and high hardness.

[0009]

The method for producing a titanium oxide film according to claim 1 of the present invention is an ammonium fluorosilicate.
As a source of hexafluorosilicon complex ions
In addition, an additive for promoting the equilibrium of SiF ₆ ²⁻ + 2H ₂ O↔SiO ₂ + 4HF + 2F ⁻ to the right is added to an aqueous solution containing hexafluorosilicon complex ions to obtain a solution 1 containing silicon oxide.
Was prepared, and the silicon oxide-containing solution 1 and the base material 2 were brought into contact with each other to form a silicon oxide coating film 3 on the surface of the base material 2, and (NH ₄ ) ₂ TiF was added to an aqueous solution containing titanium ammonium fluoride.
₆ + 2H ₂ O ⇔ TiO ₂ + 4HF + 2NH ₄ F An additive that promotes the equilibrium to the right is added to prepare a supersaturated titanium oxide-containing solution 4, and the titanium oxide-containing solution 4 and the substrate 2 are brought into contact with each other. The titanium oxide film 5 is formed on the surface of the silicon oxide film 3.

According to a second aspect of the present invention, in the method for producing a titanium oxide film, SiF ₆ is added to an aqueous solution containing hexafluorosilicon complex ions and titanium ammonium fluoride.
^{_{2- + 2H 2 O⇔SiO 2 + 4HF}} + 2F - and (NH
₄ ) ₂ TiF ₆ + 2H ₂ O ⇔ TiO ₂ + 4HF + 2NH
_A treatment liquid 6 is prepared by adding an additive for promoting the equilibrium of ₄ F to the right, and the treatment liquid 6 and the substrate 2 are brought into contact with each other to form a titanium oxide coating 7 containing silicon oxide on the surface of the substrate 2. It is characterized by being formed into.

According to a third aspect of the present invention, in the method for producing a titanium oxide film, SiF ₆ is added to an aqueous solution containing hexafluorosilicon complex ions and titanium ammonium fluoride.
^{_{2- + 2H 2 O⇔SiO 2 + 4HF}} + 2F - and (NH
₄ ) ₂ TiF ₆ + 2H ₂ O ⇔ TiO ₂ + 4HF + 2NH
_A treatment liquid 6 is prepared by adding an additive for promoting the equilibrium of ₄ F to the right, and the treatment liquid 6 and the substrate 2 are brought into contact with each other to form a titanium oxide coating 7 containing silicon oxide on the surface of the substrate 2. Formed in an aqueous solution containing titanium ammonium fluoride (N
H ₄ ) ₂ TiF ₆ + 2H ₂ O ⇔ TiO ₂ + 4HF + 2N
An oversaturated titanium oxide-containing solution 4 was prepared by adding an additive that promotes the equilibrium of H ₄ F to the right, and the titanium oxide-containing solution 4 was brought into contact with the substrate 2 to oxidize the titanium oxide coating 5 as described above. It is characterized in that it is formed on the surface of the titanium oxide film 7 containing silicon.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. First, the invention according to claim 1 of the present invention will be described in detail. Silicon oxide-containing solution 1, in an aqueous solution containing a hexafluoro silicon complex ion, SiF ₆ ² is a reversible reaction ^-
It can be prepared by adding an additive that promotes the equilibrium of + 2H ₂ O⇔SiO ₂ + 4HF + 2F ⁻ to the right (the symbol ⇔ indicates a reversible reaction). As the aqueous solution containing hexafluorosilicon complex ions, an aqueous solution using ammonium silicofluoride as an ion source of hexafluorosilicon complex ions can be used, such as an ammonium silicofluoride aqueous solution. In addition, SiF ₆ ^2- + 2H ₂ O ⇔ SiO ₂ + 4HF + 2
Any additive that promotes this reaction to the right may be used as an additive that promotes the equilibrium of F ⁻ to the right, but an aluminum salt or boric acid is used to react with fluorine to form a water-soluble stable complex. Is preferred.

The concentration of ammonium silicofluoride in the silicon oxide-containing solution 1 is preferably 0.04 mol / liter or more. If the concentration is lower than this, it will take a long time to obtain a silicon oxide film having a predetermined film thickness. The upper limit of the concentration of ammonium silicofluoride in the silicon oxide-containing solution 1 is not particularly set, but is preferably 1.0 mol / liter or less in order to avoid gelation of the solution.

If the amount of the additive used in the solution 1 containing silicon oxide is too small, silicon oxide (silica) may not be deposited on the surface of the base material, and if it is too large, a precipitate of silicon oxide may be present in the aqueous solution. There is a possibility that a silicon oxide film having a uniform thickness cannot be formed as it is generated. Therefore, when boric acid is used as an additive, boric acid is added to an aqueous solution containing hexafluorosilicon complex ions so that the concentration of boric acid in the silicon oxide-containing solution 1 is 0.1 to 0.5 mol / liter. .

The titanium oxide-containing solution 4 undergoes a reversible reaction (NH ₄ ) in an aqueous solution containing titanium ammonium fluoride.
₂ TiF ₆ + 2H ₂ O ⇔ TiO ₂ + 4HF + 2NH ₄ F
Can be prepared as a supersaturated solution of titanium oxide by adding an additive that promotes the equilibrium to the right. An aqueous solution of titanium ammonium fluoride can be used as the aqueous solution containing ammonium titanium fluoride. Also (NH ₄ ) ₂ Ti
As an additive that advances the equilibrium of F ₆ + 2H ₂ O ⇔ TiO ₂ + 4HF + 2NH ₄ F to the right and makes titanium oxide in a supersaturated state, metal oxide, boric acid, metal hydroxide, metal chloride or the like can be used. , These are used in a powder state or an aqueous solution state. Specifically, aluminum salts such as aluminum chloride and aluminum hydroxide, sodium hydroxide and boric acid are preferably used.

Titanium fluoride in solution 4 containing titanium oxide
The concentration of ammonium should be less than 0.3 mol / l.
And are preferred. If the concentration is higher than this, titanium oxide (T
iO ₂) Could not be obtained and NH_FourTiOF₃
And TiOF₂May result in a mixed film. Oxidation
The concentration of titanium ammonium fluoride in the tan-containing solution 4
The lower limit is not set in particular, but to obtain a sufficient film formation speed
It is preferably 0.08 mol / liter or more.

If the amount of the additive used in the titanium oxide-containing solution 4 is too small, titanium oxide may not be deposited on the surface of the base material, and if it is too large, titanium oxide precipitates may form in the aqueous solution. It may not be possible to form a titanium oxide film having a uniform thickness. Therefore, when boric acid is used as the additive, boric acid is added to the aqueous solution containing ammonium titanium fluoride so that the concentration of boric acid in the titanium oxide-containing solution 4 is 0.01 to 0.4 mol / liter. The reaction rate and the properties and film thickness of the deposited film are affected by the concentrations of hexafluorosilicon complex ions, titanium ammonium fluoride and the additive and the reaction temperature, and each condition is set within the above range. It is preferable to set.

The substrate 2 of the present invention may be one that does not react with or is difficult to react with both the solution 1 containing silicon oxide and the solution 4 containing titanium oxide. For example, the substrate 2 made of glass may be used. Can be used.
Further, the base material 2 may have any shape as long as its surface can contact both the silicon oxide-containing solution 1 and the titanium oxide-containing solution 4, such as a thread-shaped, plate-shaped, or pot-shaped surface or one having irregularities on the surface. Any shape can be used.

Next, the film forming step of claim 1 will be described. As shown in FIG. 2 (a), first, the base material 2 is immersed in the silicon oxide-containing solution 1 placed in a reaction vessel 10 of an appropriate size, and left standing for a predetermined time, so that the surface of the base material 2 is Silicon oxide (SiO ₂ ) is deposited to form a silicon oxide film 3 having a predetermined thickness. Silicon oxide containing solution 1 at this time
The temperature is preferably 40 ° C or higher and lower than 100 ° C. If the temperature of the silicon oxide-containing solution 1 is less than 40 ° C.,
It may take time to obtain the silicon oxide film 3 having a predetermined film thickness, and the productivity may be reduced.
When the temperature is 100 ° C. or higher, the silicon oxide-containing solution 1 may boil to prevent the deposition of a uniform film.

Next, as shown in FIG. 2 (b), the substrate 2 having the silicon oxide film 3 formed thereon is dipped in the titanium oxide-containing solution 4 contained in the reaction vessel 11 having an appropriate size, and then the predetermined amount is obtained. By leaving it for a while, titanium oxide (TiO ₂ ) is deposited on the surface of the silicon oxide coating 3 to form a titanium oxide coating 5 having a predetermined thickness as shown in FIG. At this time, the temperature of the titanium oxide-containing solution 4 is preferably 25 ° C. or higher and lower than 100 ° C. The temperature of the titanium oxide-containing solution 4 is 25 ° C.
If it is less than 1, it may take time to obtain the titanium oxide coating 5 having a predetermined film thickness and the productivity may be lowered. If the temperature of the titanium oxide containing solution 4 becomes 100 ° C. or more, the titanium oxide containing solution 4 may be obtained. May boil and prevent uniform film deposition.

In the method of forming the titanium oxide coating film 5 as described above, a substrate having any complicated shape can be used as long as it has a shape capable of contacting both the silicon oxide containing solution 1 and the titanium oxide containing solution 4. 2 can be used, and the substrate 2 having any size can be used as long as it is within the size of the reaction vessels 10 and 11. Further, it is not necessary to use expensive equipment. Therefore, in these points, the invention of claim 1 uses the conventional CVD method, P
It is superior to the dip coating method and the spin coating method by the VD method and the sol-gel method.

Further, according to the present invention, the silicon oxide coating 3 and the titanium oxide coating 5 can be formed by a simple method of preparing the silicon oxide containing solution 1 and the titanium oxide containing solution 4 and immersing the substrate 2. It does not require the work of saturating silica or the work of filtering unlike the method of forming a film using hydrosilicofluoric acid in the above-mentioned conventional example. Further, in the invention of claim 1, since the silicon oxide film 3 having good adhesion to the substrate 2 is interposed between the substrate 2 and the titanium oxide film 5, the temperature is low (often 50 ° C. or lower). Despite the fact that the titanium oxide film 5 is formed by the method described above, the adhesion between the base material 2 and the titanium oxide film 5 can be increased, and the titanium oxide film 5 can be reinforced with the silicon oxide film 3 to form the titanium oxide film 5. The hardness (strength) can be increased. Therefore, titanium oxide film 5
In order to increase the adhesion and hardness (strength) of the present invention, the present invention is more preferable than the above-mentioned conventional film forming method using a heat treatment at a temperature of 500 ° C. or higher or a gas phase method in which the reaction temperature is about 500 ° C. Are better. As described above, the titanium oxide coatings 5 and 7 obtained by the present invention can have high adhesion to the substrate 2 and hardness (strength) without heat treatment. When the heat treatment is performed on the base material 2, the adhesion (adhesive strength) and the hardness (strength) to the base material 2 can be further improved. Therefore, the heat treatment may be performed if necessary.

Next, the invention according to claim 2 of the present invention will be described in detail. According to the invention of claim 2, SiF ₆ ^2- + 2H ₂ O ⇔ SiO ₂ + 4HF + 2F is added to an aqueous solution containing hexafluorosilicon complex ions and titanium ammonium fluoride.
^- and _{(NH 4) 2 TiF 6 +} 2H 2 O⇔TiO 2 +4
Treatment liquid 6 prepared by adding an additive that advances the equilibrium of HF + 2NH ₄ F to the right is used.
The treatment liquid 6 is, for example, a mixed solution of an aqueous solution containing a hexafluorosilicon complex ion (ammonium silicofluoride aqueous solution) and an aqueous solution containing ammonium titanium fluoride (ammonium titanium fluoride aqueous solution), which are exemplified in the embodiment of claim 1 above. It can be prepared by adding an aluminum salt or boric acid as an additive.

The concentration of ammonium titanium fluoride in the treatment liquid 6 is preferably 0.05 to 0.2 mol / liter. When the concentration of titanium ammonium fluoride is less than 0.05 mol / liter, it takes a long time to form a coating film, which may reduce the productivity. When the concentration of titanium ammonium fluoride exceeds 0.2 mol / liter, the base material 2
The film formed on the substrate is not a titanium oxide film 7 containing silicon oxide, but becomes a titanium oxide film mixed with NH ₄ TiOF _{3, and} there is a possibility that the adhesion of the titanium oxide film to the base material 2 may deteriorate. .

The preferable concentration region of the hexafluorosilicon complex ion (ammonium silicofluoride) in the treatment liquid 6 varies depending on the concentrations of the ammonium titanium fluoride and the treatment liquid 6, but the molar ratio of titanium and silicon contained in the treatment liquid 6. The ratio of the number of moles of silicon to the total number, that is, Si
/ (Si + Ti) is preferably 0.4 to 0.8 (where Si represents the molar concentration of silicon in the treatment liquid 6 and Ti represents the molar concentration of titanium in the treatment liquid 6). For example, when a titanium oxide coating 7 having a high visible light transmittance and a high coating hardness (strength) is obtained, the above Si / (Si + T
The ratio i) is preferably set to 0.7 or more, and when it is desired to increase the titanium content in the titanium oxide coating 7, the Si / (Si + Ti) ratio is set to 0.7 or less. Is preferred. When this titanium oxide coating 7 is used as a photocatalyst, it is better to increase the titanium content of the titanium oxide coating 7 containing silicon oxide by increasing the molar ratio of titanium in the treatment liquid 6 in order to enhance the photocatalytic activity. preferable.

If the amount of the additive used in the treatment liquid 6 is too small, the titanium oxide coating 7 containing silicon oxide may not be deposited on the surface of the base material 2. If it is too large, the amount of silicon oxide contained in the aqueous solution may increase. There is a possibility that a precipitate may be generated and the titanium oxide coating 7 having a uniform thickness may not be formed. Therefore, when boric acid is used as an additive, boric acid is added to an aqueous solution containing hexafluorosilicon complex ions and titanium ammonium fluoride so that the concentration of boric acid in the treatment liquid 6 is 0.1 to 0.5 mol / liter. Of.

Next, the film forming step of claim 2 will be described. As shown in FIG. 3, the base material 2 is immersed in the treatment liquid 6 placed in a reaction vessel 12 having an appropriate size and left for a predetermined time, so that silicon oxide (S
Both iO ₂ ) and titanium oxide (TiO ₂ ) are deposited to form a titanium oxide film (SiO ₂ / TiO ₂ ) 7 having a predetermined film thickness containing silicon oxide as shown in FIG.
The temperature of the treatment liquid 6 at this time is preferably 25 ° C. or higher and lower than 100 ° C. If the temperature of the treatment liquid 6 is less than 25 ° C., it may take time to obtain the titanium oxide film 7 having a predetermined film thickness and the productivity may be lowered. Further, if the temperature of the treatment liquid 6 becomes 100 ° C. or more. However, the treatment liquid 6 may boil to prevent the uniform deposition of the titanium oxide film 7.

The invention of claim 2 which forms the titanium oxide coating film (composite film of silicon oxide and titanium oxide) 7 containing silicon oxide in this way has the same effect as the invention of claim 1 above. However, since the titanium oxide coating 7 containing silicon oxide is formed, the adhesion of the titanium oxide coating 7 to the base material 2 can be improved by adding silicon oxide having high adhesion to the base material 2. It is possible to obtain the titanium oxide coating 7 having a high hardness (strength). Further, as compared with the invention of claim 1, the number of film forming steps is smaller, so that the productivity can be improved.

Next, the invention of claim 3 will be described. Contract
The invention of claim 3 is a hexafluorosilicon complex ion and
SiF in an aqueous solution containing titanium ammonium fluoride₆ ^2-
+ 2H₂O⇔SiO₂+ 4HF + 2F^-And (NH_Four)
₂TiF₆+ 2H₂O⇔TiO₂+ 4HF + 2NH_FourF
Prepared by adding additives that promote the equilibrium of
The treatment liquid 6 to be contacted with the base material 2 is oxidized on the surface of the base material 2.
A titanium oxide film 7 containing silicon is formed, and thereafter titanium
In an aqueous solution containing ammonium fluoride (NH _Four)₂T
iF₆+ 2H₂O⇔TiO₂+ 4HF + 2NH_FourF no Taira
Titanium oxide is supersaturated by adding an additive that moves the balance to the right.
Titanium Oxide-Containing Solution 4 and Silicon Oxide
Contact the base material 2 on which the titanium oxide coating 7 is formed.
On the surface of the titanium oxide film 7 containing silicon oxide.
The tongue coating 5 is formed.

The treatment liquid 6 may be the one used in the embodiment of claim 2 above, and the titanium oxide-containing solution 4 may be the one used in the embodiment of claim 1 above. be able to. Next, the film forming step of claim 3 will be described. As shown in FIG. 5A, the base material 2 is immersed in the treatment liquid 6 placed in a reaction vessel 13 having an appropriate size, and left standing for a predetermined time, so that the surface of the base material 2 is silicon oxide. (SiO ₂ ) and titanium oxide (TiO 2
Both of ₂ ) are deposited to form a titanium oxide film (SiO ₂ / TiO ₂ ) 7 containing silicon oxide and having a predetermined film thickness. The temperature condition of the processing liquid 6 at this time is the same as that of the embodiment of claim 2.

Next, the base material 2 on which the titanium oxide film 7 is formed
As shown in FIG. 5 (b), the reaction vessel 14 having an appropriate size
As shown in FIG. 6, the surface of the titanium oxide coating film 7 containing silicon oxide is coated with titanium oxide (Ti
O ₂ ) is deposited to form a titanium oxide film 5 having a predetermined thickness. The temperature condition of the titanium oxide-containing solution 4 at this time is the same as that of the embodiment of claim 1.

The invention of claim 3 in which the titanium oxide coating 5 is formed in this way has the same effect as that of the invention of claim 1, but in particular the substrate 2 and the titanium oxide coating 5 are formed.
Since the titanium oxide coating 7 containing silicon oxide is formed between the two, it is possible to enhance the adhesion of the titanium oxide coating 7 to the base material 2 by containing silicon oxide having high adhesion to the base material 2. Therefore, the adhesion between the titanium oxide coating 5 and the substrate 2 can be further enhanced. In the third aspect, the titanium oxide coating 5 may contain a small amount of silicon oxide to enhance the adhesion between the titanium oxide coating 5 and the titanium oxide coating 7 containing silicon oxide.

[0033]

EXAMPLES The present invention will be described in detail below with reference to examples. (Example 1) Length and width are 50 mm, and thickness is 1.3 m
m soda lime glass thoroughly washed and dried,
The base material 2 was used. The concentration is 0.4 mol / liter (N
H_Four)₂SiF₆Prepare 62.5 ml of aqueous solution
And a boric acid solution with a concentration of 0.5 mol / liter
Add 100 ml of water and dilute it with water to 250
A solution 1 containing silicon oxide was prepared. This acid
(NH in solution 1 containing silicon oxide) _Four)₂SiF₆The concentration of
0.1 mol / liter, and the concentration of boric acid is 0.2 mol.
It was le / liter. 50% of this silicon oxide containing solution 1
The substrate 2 was vertically dipped while being held at 0 ° C. On this occasion
Dip up to the bottom 40 mm of the base material 2 and top 10 mm
The part of is protected from contact with the solution 1 containing silicon oxide.
I had After 4 hours, the base material 2 is pulled up and washed with water.
A silicon oxide film 3 was formed on the surface of the base material 2.

(NH ₄ ) having a concentration of 0.4 mol / liter
62.5 ml of ₂ TiF ₆ aqueous solution was prepared, 100 ml of 0.5 mol / liter boric acid aqueous solution was added thereto, and this was diluted with water to prepare 250 ml of titanium oxide-containing solution 4. In this titanium oxide-containing solution 4, the concentration of (NH ₄ ) ₂ TiF ₆ was 0.1 mol / liter, and the concentration of boric acid was 0.2 mol / liter. While holding the titanium oxide-containing solution 4 at 30 ° C., the substrate 2 on which the silicon oxide coating 3 was formed was vertically dipped. At this time, the lower part of the base material 2 was immersed up to 40 mm, and the upper part of 10 mm was held so as not to come into contact with the titanium oxide-containing solution 4. After 2 hours, the base material 2 was pulled up, washed with water and dried to form a transparent titanium oxide coating 5 showing a blue interference color on the surface of the silicon oxide coating 3.

(Embodiment 2) Alkali-free glass (Corning # 70) having a length and width of 50 mm and a thickness of 1.3 mm.
59) was thoroughly washed and dried to obtain a base material 2 for a sample. 62.5 ml of (NH ₄ ) ₂ SiF ₆ aqueous solution having a concentration of 0.4 mol / l and 62.5 ml of (NH ₄ ) ₂ TiF ₆ aqueous solution having a concentration of 0.4 mol / l were prepared respectively. And a concentration of 0.
100 ml of a 5 mol / liter boric acid aqueous solution was added, and this was diluted with water to prepare 250 ml of treatment liquid 6. (NH ₄ ) ₂ SiF _{6 in} this treatment liquid ₆
Concentration of 0.1 mol / l, and (NH ₄ ) ₂ T
The concentration of iF ₆ was 0.1 mol / liter, and the concentration of boric acid was 0.2 mol / liter.

The substrate 2 was vertically dipped while maintaining the treatment liquid 6 at 50 ° C. At this time, the lower part 40 mm of the base material 2
Was dipped to the portion of 10 mm, and the upper portion of 10 mm was held so as not to come into contact with the silicon oxide-containing solution 1. After the lapse of 15 hours, the base material 2 was pulled up, washed with water and dried to form a titanium oxide coating film 7 containing silicon oxide, which is transparent and shows an interference color of yellow-green, on the surface of the base material 2.

(Embodiment 3) The length and width are 50 mm and the thickness is
Thoroughly clean and dry 1.3 mm soda lime glass
It was dried and used as the base material 2 of the sample. Concentration 0.4 mol / lit
Le's (NH_Four)₂SiF₆62.5 millilitres of aqueous solution
And concentration of 0.4 mol / liter (NH _Four)₂TiF
₆Prepare 62.5 milliliters of each aqueous solution.
Those with a concentration of 0.5 mol / l
Add 100 ml of the aqueous acid solution and dilute it with water.
250 ml of the treatment liquid 6 was prepared. This process
(NH in liquid 6_Four)₂SiF₆Concentration of 0.1 mol / l
In addition, (NH_Four)₂TiF₆The concentration of 0.1
And the concentration of boric acid is 0.2 mol / liter.
It was a turtle.

The substrate 2 was vertically dipped while maintaining the treatment liquid 6 at 50 ° C. At this time, the lower part 40 mm of the base material 2
Was dipped to the portion of 10 mm, and the upper portion of 10 mm was held so as not to come into contact with the silicon oxide-containing solution 1. After 4 hours, the base material 2 was pulled up and washed with water to form a titanium oxide coating film 7 containing silicon oxide on the surface of the base material 2. The concentration is 0.
6 mol of 4 mol / liter (NH ₄ ) ₂ TiF ₆ aqueous solution
2.5 ml was prepared, 100 ml of a boric acid aqueous solution having a concentration of 0.5 mol / liter was added thereto, and this was diluted with water to prepare 250 ml of titanium oxide-containing solution 4. (NH in the titanium oxide-containing solution 4)
The concentration of ₄ ) ₂ TiF ₆ was 0.1 mol / liter, and the concentration of boric acid was 0.2 mol / liter. While holding the titanium oxide-containing solution 4 at 30 ° C., the substrate 2 having the titanium oxide coating 7 formed thereon was vertically dipped. At this time, the base material 2 was dipped to a lower portion of 40 mm, and the upper portion was 10 m.
The portion m was held so as not to come into contact with the titanium oxide-containing solution 4. After 2 hours, the substrate 2 was pulled up, washed with water and dried to form a transparent titanium oxide coating 5 showing a blue interference color on the surface of the titanium oxide coating 7 containing silicon oxide.

Comparative Example Soda-lime glass having a length of 50 mm and a width of 1.3 mm and a thickness of 1.3 mm was thoroughly washed and dried to obtain a base material 2 for a sample. Prepare 62.5 ml of an aqueous solution of (NH ₄ ) ₂ TiF ₆ having a concentration of 0.4 mol / liter, add 100 ml of an aqueous solution of boric acid having a concentration of 0.5 mol / liter, and dilute it with water to 25
A solution 4 containing 0 ml of titanium oxide was prepared. In this titanium oxide-containing solution 4, the concentration of (NH ₄ ) ₂ TiF ₆ was 0.1 mol / liter, and the concentration of boric acid was 0.
It was 2 mol / liter. This titanium oxide containing solution 4
Was held at 30 ° C., and the substrate 2 was vertically immersed.
At this time, the base material 2 was immersed in the lower part of 40 mm and the upper part 1
The 0 mm portion was held so as not to come into contact with the titanium oxide-containing solution 4. After 2 hours, the base material 2 was pulled up, washed with water and dried to form a transparent titanium oxide coating 5 showing a blue interference color on the surface of the base material 2.

The pencil hardness of the titanium oxide coatings 5 and 7 of Examples 1 to 3 and Comparative Example was measured. In addition, the performance of photocatalytic activity of the titanium oxide coatings 5 and 7 of Examples 1 to 3 and Comparative Example was evaluated. This performance was evaluated by the decomposition performance of acetaldehyde under irradiation of black light. The results are shown in Table 1.
Shown in.

[0041]

[Table 1]

As can be seen from Table 1, the titanium oxide coatings 5 and 7 of Examples 1 to 3 can have a higher pencil hardness than the titanium oxide coating 5 of the comparative example without being subjected to heat treatment such as firing. It was Further, in Examples 1 and 3, the pencil hardness could be further improved by firing.

[0043]

As described above, according to the invention described in claim 1 of the present invention , ammonium fluorosilicofluoride is added to hexafluorosilyl.
SiF ₆ ²⁻ + 2H ₂ O ⇔ in an aqueous solution containing hexafluorosilicon complex ions as an ion source of the complex ions
A silicon oxide-containing solution is prepared by adding an additive that advances the equilibrium of SiO ₂ + 4HF + 2F ⁻ to the right, and the silicon oxide-containing solution is contacted with the base material to form a silicon oxide film on the surface of the base material. (NH ₄ ) ₂ TiF ₆ + 2H ₂ O ⇔ TiO ₂ + 4HF + in an aqueous solution containing ammonium chloride
A supersaturated titanium oxide-containing solution is prepared by adding an additive that advances the equilibrium of 2NH ₄ F to the right, and the titanium oxide-containing solution is brought into contact with the substrate to form a titanium oxide film on the surface of the silicon oxide film. Since the titanium oxide film is formed, the titanium oxide film can be formed on the surface of the base material without using a special and expensive device, and the manufacturing cost can be reduced. Further, as long as it has a shape capable of contacting both the silicon oxide-containing solution and the titanium oxide-containing solution, a base material of any complicated shape can be used, and restrictions on the base material should be reduced. Is something that can be done. Furthermore, since a silicon oxide film having high adhesion to the base material is formed between the titanium oxide film and the base material, it is necessary to form a titanium oxide film having high adhesion to the base material and high hardness without heat treatment. Is something that can be done.

Further, the invention according to claim 2 of the present invention is that SiF ₆ ^2- + 2H ₂ O ⇔ SiO is added to an aqueous solution containing hexafluorosilicon complex ions and titanium ammonium fluoride.
₂ + 4HF + 2F ⁻ and (NH ₄ ) ₂ TiF ₆ + 2H ₂
A treatment liquid is prepared by adding an additive that promotes the equilibrium of O⇔TiO ₂ + 4HF + 2NH ₄ F to the right, and the treatment liquid is brought into contact with the substrate to form a titanium oxide film containing silicon oxide on the surface of the substrate. Since it is formed as described above, the titanium oxide film can be formed on the surface of the base material without using a special and expensive device, and the manufacturing cost can be reduced. In addition, if the shape can contact the processing liquid,
It is possible to use a substrate having any complicated shape, and it is possible to reduce restrictions on the substrate. Further, since the titanium oxide coating contains silicon oxide having high adhesion to the substrate, the titanium oxide coating having high adhesion to the substrate and high hardness can be formed without heat treatment. .

The invention according to claim 3 of the present invention is that SiF ₆ ^2- + 2H ₂ O ⇔ SiO is added to an aqueous solution containing hexafluorosilicon complex ions and titanium ammonium fluoride.
₂ + 4HF + 2F ⁻ and (NH ₄ ) ₂ TiF ₆ + 2H ₂
A treatment liquid is prepared by adding an additive that promotes the equilibrium of O⇔TiO ₂ + 4HF + 2NH ₄ F to the right, and the treatment liquid is brought into contact with the substrate to form a titanium oxide film containing silicon oxide on the surface of the substrate. To form (NH ₄ ) ₂ TiF ₆ + 2H ₂ O ⇔ Ti in an aqueous solution containing titanium ammonium fluoride.
A supersaturated titanium oxide-containing solution was prepared by adding an additive that advances the equilibrium of O ₂ + 4HF + 2NH ₄ F to the right,
Since this titanium oxide-containing solution was brought into contact with the substrate to form the titanium oxide film on the surface of the titanium oxide film containing silicon oxide, the titanium oxide film was formed on the surface of the substrate without using a special and expensive device. A film can be formed, and the manufacturing cost can be reduced. Further, as long as it has a shape capable of contacting both the treatment liquid and the titanium oxide-containing solution, a base material of any complicated shape can be used, and restrictions on the base material can be reduced. It is a thing. Further, since the titanium oxide film containing silicon oxide having high adhesion to the substrate is formed between the titanium oxide film and the substrate, titanium oxide having high adhesion to the substrate and high hardness without heat treatment. A film can be formed.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of an embodiment of the present invention.

2A and 2B are cross-sectional views showing steps of the same.

FIG. 3 is a cross-sectional view showing a process of another embodiment of the above.

FIG. 4 is a sectional view showing an example of another embodiment of the above.

5 (a) and 5 (b) are cross-sectional views showing a process of still another embodiment of the same.

FIG. 6 is a sectional view showing an example of still another embodiment of the above.

[Explanation of symbols]

1 Silicon oxide containing solution 2 base materials 3 Silicon oxide coating 4 Titanium oxide containing solution 5 Titanium oxide coating 6 treatment liquid 7 Titanium oxide coating containing silicon oxide

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor, adult, Sumiyoshidai, 4-1-1-807, Sumiyoshidai, Higashinada-ku, Kobe-shi, Hyogo Prefecture (56) Reference JP-A-8-108075 (JP, A) JP-A-64-28376 ( JP, A) JP-A-3-285822 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C01G 23/00 C01B 33/00

Claims (3)

(57) [Claims] 1. Ammonium silicofluoride is added to hexafluor
SiF ₆ ²⁻ + 2H was added to an aqueous solution containing hexafluorosilicon complex ions, which was used as an ion source for the silicon complex ions.
_A silicon oxide-containing solution is prepared by adding an additive that advances the equilibrium of ₂ O ⇔ SiO ₂ + 4HF + 2F ⁻ to the right, and the silicon oxide-containing solution is contacted with the substrate to form a silicon oxide film on the surface of the substrate. Then, in an aqueous solution containing titanium ammonium fluoride, (NH ₄ ) ₂ TiF ₆ + 2H ₂ O ⇔ TiO ₂ + 4H
A supersaturated titanium oxide-containing solution was prepared by adding an additive that promotes the equilibrium of F + 2NH ₄ F to the right, and the titanium oxide-containing solution was brought into contact with the substrate to form a titanium oxide film on the surface of the silicon oxide film. A method for producing a titanium oxide coating film, comprising: 2. SiF ₆ ^2- + in an aqueous solution containing hexafluorosilicon complex ions and titanium ammonium fluoride.
2H ₂ O ⇔ SiO ₂ + 4HF + 2F ^- and (NH ₄ ) ₂
A treatment liquid is prepared by adding an additive that promotes the equilibrium of TiF ₆ + 2H ₂ O ⇔ TiO ₂ + 4HF + 2NH ₄ F to the right, and the treatment liquid is contacted with the base material to form a titanium oxide film containing silicon oxide. A method for producing a titanium oxide film, which comprises forming the titanium oxide film on the surface of a base material. 3. SiF ₆ ²⁻ + in an aqueous solution containing hexafluorosilicon complex ions and titanium ammonium fluoride.
2H ₂ O ⇔ SiO ₂ + 4HF + 2F ^- and (NH ₄ ) ₂
A treatment liquid is prepared by adding an additive that promotes the equilibrium of TiF ₆ + 2H ₂ O ⇔ TiO ₂ + 4HF + 2NH ₄ F to the right, and the treatment liquid is contacted with the base material to form a titanium oxide film containing silicon oxide. It is formed on the surface of the base material, and (NH ₄ ) ₂ TiF _{6 is} added in an aqueous solution containing titanium ammonium fluoride.
A supersaturated titanium oxide-containing solution is prepared by adding an additive that promotes the equilibrium of + 2H ₂ O ⇔ TiO ₂ + 4HF + 2NH ₄ F to the right, and the titanium oxide-containing solution is contacted with a substrate to form a titanium oxide film. A method for producing a titanium oxide film, which comprises forming the titanium oxide film containing silicon oxide on the surface of the titanium oxide film.