JPH11269725A - Composite metal oxide and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composite metal oxide having a good photocatalyst activity and an excellent mechanical strength, and to provide a method for producing the same. SOLUTION: This composite metal oxide comprises the non-sintered state calcination product of a mixture comprising (A) a polymer having an average polymerization degree of 10-10,000 and produced from a metal compound capable of inducing a metal oxide having a photocatalyst activity by a crystallization treatment and (B) a polymer having an average polymerization degree of 10-10,000 and produced from a metal compound capable of inducing a different kind of metal oxide, wherein the metal oxide polymer blocks derived from the polymers A and B are chemically bound to each other. The method for producing the composite metal oxide comprises preparing the polymers A and B by sol-gel methods, respectively, and subsequently calcining a mixture of the polymers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite metal oxide and a method for producing the same, and more particularly, to a chemical bond between a polymer block of a metal oxide having photocatalytic activity and a polymer block of another heterogeneous metal oxide. It has good photocatalytic activity and superhydrophilicity, and has excellent mechanical strength, and is used for various applications as a film-like material or fiber, and also as a mat-like material such as a mat, woven fabric, or non-woven fabric. The present invention relates to a composite metal oxide that can be produced, and a method for producing the composite metal oxide efficiently and industrially advantageously.

[0002]

2. Description of the Related Art By using a semiconductor such as titanium dioxide as a photoelectrode, water is photodecomposed into hydrogen and oxygen, the so-called Honda-Fujishima effect [Industrial Chemistry Magazine, Vol.
08-113 (1969) ", the research and development of photocatalysts have been actively conducted. This photocatalyst, for example, excites semiconductor particles such as titanium dioxide with light having energy equal to or greater than the band gap, thereby generating electrons in the conduction band and holes in the valence band. It utilizes hole pairs. Applying such a photocatalyst, for example, deodorization, antifouling, antibacterial, sterilization, as well as decomposition / removal of various substances, which are environmental pollution problems in wastewater and waste gas, are being studied.

As the photocatalyst, compounds having various semiconductor properties, such as metal oxides such as titanium dioxide, iron oxide, tungsten oxide and zinc oxide, and metal sulfides such as cadmium sulfide and zinc sulfide have been known. However, among these, titanium dioxide, particularly anatase type titanium dioxide, is useful as a practical photocatalyst. This titanium dioxide exhibits excellent photocatalytic activity by absorbing light of a specific wavelength in the ultraviolet region included in daily light such as sunlight, and has a strong oxidizing action derived from this photocatalytic action to prevent stains, odors, and antibacterial properties. It performs functions such as air purification, water purification and super hydrophilicity.

[0004] Research is being actively conducted to effectively exhibit such a photocatalytic function possessed by a photocatalyst such as titanium dioxide and to industrially utilize the photocatalytic function. Since this photocatalyst is generally commercially available as a fine powder, the present situation is that the photocatalyst powder is supported on the substrate by any method depending on the use or the substrate, and is used industrially. As a method for carrying the carrier, it is common to carry the carrier using an inorganic binder such as a silane coupling agent or a condensate thereof,
In this method, there is a problem that the bond is not so strong, so that the photocatalyst powder is inevitably lost. In particular, it is actually very difficult to form a strong photocatalyst film.

[0005] In recent years, attention has been paid to a titanium dioxide fine powder and a silica fine powder having a high effect of maintaining hydrophilicity supported on a substrate by the inorganic binder, and various proposals have been made (Japanese Patent Application Laid-Open No. Hei 9 (1997) -92). -57912, JP-A-9-59041, JP-A-9-59042). However, these supports also have a problem that the bond is not strong, and the long-term stability is poor.

By the way, if such a photocatalyst can be made into a fibrous form, it becomes possible to produce mats such as various woven fabrics, knits and non-woven fabrics. It is possible to produce it, and the use as a photocatalytically active material can be expected to be expanded. In this case, the film or fibrous material needs to have practical strength.

Therefore, as a method for increasing the strength of the photocatalyst film or the photocatalyst structure, mixing of an amorphous component can be considered. A general method of composite ceramics utilizes sintering. Fine powder of ceramics to be composited is uniformly mixed. For example, in the case of a titania-silica composite,
Sintering is performed by heating to a high temperature of 00 ° C. or higher. This method
If the temperature is lower than the sintering temperature, it is difficult to obtain a composite having sufficient strength due to poor adhesion between ceramics. Therefore, a crystal form having high photocatalytic function (anatase type in the case of titanium oxide) can be expressed. Impossible.

On the other hand, a sol-gel method is known as a low-temperature compounding method. According to this method, a precursor obtained by mixing and hydrolyzing a metal salt or a metal alkoxide is calcined at a relatively low temperature, whereby a uniform composite can be easily produced. For example, attempts have been made to produce fibers with high strength by compounding titanium oxide and amorphous silica ["Journal of Sol-Gel."
Science and Technology (J. Sol-Gel S
ci. Tech.), Vol. 9, pp. 85-93 (1997)
Year), "Journal of the Ceramic Society of Japan," Vol. 86, Nos. 1547-1551
Page (1976), Journal of the Ceramic Industry Association, Vol. 87, No. 1
552-1558 (1977)].

At this time, a fiber is spun from a viscous polymer obtained by mixing a raw material alkoxide of titanium and a silicon alkoxide and hydrolyzing the mixture, followed by baking to obtain the desired high strength. I have fiber. However, in this method, since mixing is performed at the monomer stage, the probability of generation of a Ti—O—Si bond is high, and the addition of the amorphous component to 20% by volume can convert the titanium oxide component to the anatase type. The transition (usually, in the case of a single system, the transition temperature is 300 to 400 ° C.) is inhibited, and a temperature of about 1000 ° C. is required for phase transition, and the phase transition rate is low. there were. In addition, firing at an extremely high temperature, such as 1000 ° C. or more, causes a problem that titanol and silanol on the surface are reduced and the photocatalytic ability is reduced. In other words, this method has the advantage of enabling uniform compounding at the atomic level, but on the other hand, in the case of compounding utilizing performance based on the crystal state, the firing temperature must be lowered, Degree of conversion
In addition, in order to sufficiently cause crystallization, the firing temperature must be extremely high, and there is a problem such as a decrease in hydroxyl groups present on the surface for effectively exhibiting photocatalytic activity.
Sufficient photocatalytic activity could not be exhibited.

[0010]

SUMMARY OF THE INVENTION Under such circumstances, the present invention has good photocatalytic activity and superhydrophilicity, excellent mechanical strength, film-like materials, fibers, mats, and woven fabrics. ,
An object of the present invention is to provide a composite metal oxide that can be used for various applications as a nonwoven fabric and the like, and a method for efficiently and industrially producing the same.

[0011]

Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above object, and as a result, have found that a polymer of a metal compound capable of deriving a metal oxide having photocatalytic activity by crystallization treatment is obtained. , Which is obtained by firing a mixture comprising a polymer of a metal compound capable of deriving a different metal oxide in a non-sintered state, and a polymer block of a metal oxide derived from each polymer. The composite metal oxide formed by chemically bonding is suitable for the purpose, and the composite metal oxide is prepared by a sol-gel method after preparing a polymer of the metal compound having a specific average polymerization degree, They found that they can be manufactured by mixing and firing them, and based on this finding, completed the present invention.

That is, the present invention relates to (A) a polymerization having an average degree of polymerization of 10 to 10,000 obtained from a metal organic compound or a metal inorganic compound capable of deriving a metal oxide having photocatalytic activity by a single crystallization treatment. And (B) an average degree of polymerization of 10 to 100 obtained from a metal organic compound or a metal inorganic compound capable of inducing a metal oxide different from the above.
A non-sintered fired product of a mixture consisting of the polymer of No. 00 and a polymer block of the metal oxide derived from the polymer (A) and a metal oxide derived from the polymer (B) And a composite metal oxide characterized by being chemically bonded to a polymer block.

According to the present invention, the composite metal oxide is a metal organic compound or a metal inorganic compound capable of deriving a metal oxide having photocatalytic activity by a single crystallization treatment, Using a metal organic compound or a metal inorganic compound capable of deriving a metal oxide as a raw material, the average degree of polymerization is 10 to 10 by a sol-gel method.
After obtaining a polymer of 000, it can be manufactured by mixing and firing.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The composite metal oxide of the present invention comprises
(A) a polymer obtained from a metal organic compound or a metal inorganic compound capable of deriving a metal oxide having photocatalytic activity by a single crystallization treatment; and (B) a metal oxide different from the above. It is obtained by firing a mixture with a polymer obtained from a metal organic compound or a metal inorganic compound which can be sintered, in a non-sintered state.

Both the polymer (A) and the polymer (B) have an average degree of polymerization in the range of 10 to 10,000, and when the average degree of polymerization is out of the above range, the spinning property and the film forming property are reduced. Properties, etc., and the object of the present invention cannot be achieved. The preferred average degree of polymerization is in the range of 10 to 7,000.

As the polymer (A), a polymer obtained from a metal organic compound or a metal inorganic compound capable of deriving a metal oxide having photocatalytic activity by a single crystallization treatment is used. Here, the metal oxide having photocatalytic activity by a single crystallization treatment is not particularly limited, but preferably includes, for example, titania and / or zinc oxide, particularly from the viewpoint of photocatalytic activity and practicality. And titania are preferred.

Examples of the above-mentioned metal organic compounds include metal organic compounds such as organic titanium compounds and organic zinc compounds having at least one hydrolyzable organic group such as an alkoxy group. On the other hand, examples of the metal inorganic compound include metal halides represented by chlorides such as titanium tetrachloride and zinc dichloride.

As a polymer obtained from a metal organic compound or a metal inorganic compound capable of inducing titania, a hydrolyzate of a titanium compound represented by the following general formula (II) can be preferably mentioned.

On the other hand, the polymer (B) includes the above (A)
What is obtained from a metal organic compound or a metal inorganic compound which can induce a different metal oxide is used. Here, the metal oxide different from (A) is not particularly limited, but preferably includes, for example, silica, alumina and zirconia. In particular, from the viewpoint of the performance and practicality of the obtained composite metal oxide, Silica is preferred.

Examples of the above-mentioned metal organic compounds include metal organic compounds having at least one hydrolyzable organic group such as an alkoxy group, such as organic silicon compounds, organic aluminum compounds, and organic zirconium compounds. On the other hand, examples of the metal inorganic compound include metal halides represented by chlorides such as silicon, aluminum and zirconium.

Further, the polymer obtained from a metal organic compound or a metal inorganic compound capable of deriving silica includes:
Preferred examples include a hydrolyzate of a silicon compound represented by the following general formula (III). In the present invention, the mixing ratio of the polymer (A) and the polymer (B) is not particularly limited, and is appropriately selected according to the desired photocatalytic activity and mechanical strength of the obtained composite metal oxide. do it. The composite metal oxide of the present invention is obtained by firing a mixture of the polymer (A) and the polymer (B) in a non-sintered state. Can be appropriately selected according to the kind of the metal of the polymer and the polymer (B). The form of the composite metal oxide of the present invention is not particularly limited, and can take various forms, such as a film-like material, a fiber, a web, or a nonwoven fabric, a woven fabric, or a mat-like material such as a mat. . Here, the film-like material can be produced by forming a film-like material on a substrate using a mixture of the polymer (A) and the polymer (B), followed by baking. , (A) polymer and (B)
It can be produced by firing a fibrous material obtained by spinning a mixture with a polymer. By further processing the fiber thus obtained, a web, and further, a mat-like material such as a nonwoven fabric, a woven fabric, and a mat can be produced. For example, in the case of a continuous fiber, a fiber alone or mixed with an inorganic fiber such as a glass fiber, and in the case of a short fiber, a fiber spun alone or a fiber mixed with an inorganic fiber such as a glass fiber is used as a raw yarn. For example, a woven fabric can be manufactured using a loom such as a shuttle loom or a water jet loom, and a knit can be manufactured using a knitting machine such as a Russell knitting machine or a tricot knitting machine. Further, in the case of short fibers, after forming the web, a nonwoven fabric can be produced by a dry process such as a nonwoven process using an adhesive or a needle punch method, or a wet process such as a papermaking process. Also, as described in the examples, after the fibers thinned and discharged from the nozzle by the air are laminated on an appropriate support (net or the like), a mat is obtained by firing the fibers to obtain a mat in which the fibers are bonded to each other. Can be.

The fiber comprising the composite metal oxide of the present invention is, in particular, a baked fibrous material obtained by spinning a mixture of a titania polymer and a silica polymer by a sol-gel method, and wherein the titania component is contained. In a pigment decomposition test using titania-silica fiber (hereinafter referred to as titania-silica fiber I) having a photocatalytic activity mainly composed of anatase type crystal form, and methylene blue, 60 minutes after the titania single fiber, Assuming that the decomposition rate is 100%, the decomposition rate A% after 60 minutes is represented by the formula (I) A (%) ≧ [the number of titanium atoms in the fiber / the total number of titanium atoms and silicon atoms in the fiber] × A titania-silica fiber having photocatalytic activity that satisfies the relationship of 100 (I) (hereinafter referred to as titania-silica fiber II) can be preferably exemplified.

Here, the sol-gel method means a method of producing a titania polymer or a silica polymer by hydrolysis and polycondensation reaction of a titanium compound and a silicon compound. The titania-silica fiber I is different from the conventional titania-silica fiber in that the generation of the Ti—O—Si bond is suppressed, so that the degree of decrease in the photocatalytic activity with respect to the fiber composed of only the anatase-type titania is small and good. Photocatalytic activity. This titania-silica fiber I
In, as a titania polymer by the sol-gel method,
As a hydrolyzate of a titanium compound represented by the following general formula (II) and a silica polymer obtained by a sol-gel method, a hydrolyzate of a silicon compound represented by a general formula (III) described below can be exemplified. . The mixing ratio of the titania polymer and the silica polymer is not particularly limited, and may be appropriately selected according to the desired photocatalytic activity and mechanical strength of the obtained fiber.

The titania-silica fiber I or the titania-silica fiber II according to the present invention has an average fiber diameter of 20.
It is preferable that the average fiber length is 1 mm or more and the tensile strength of single fiber yarn is 0.5 GPa or more. Further, the photocatalytic activity of the titania-silica fiber is usually 50% or more of the anatase type titania fiber.

The photocatalytic activity of the fiber can be measured as follows. That is, after a spinning material for a fiber whose photocatalytic activity is to be measured is applied on a substrate such as a glass plate, the fiber is fired under substantially the same firing conditions as when the fiber was produced. Next, after performing a superhydrophilization treatment by irradiating the coated surface with ultraviolet rays or the like, an organic dye such as methylene blue is adsorbed, and the decomposition rate of the organic dye is determined.
The photocatalytic activity can be determined by measuring by an absorbance method or the like. The titania-silica fiber I comprises a baked fiber obtained by spinning a mixture of a titania polymer and a silica polymer by a sol-gel method, and the spinning method includes the above titania polymer and silica. It is advantageous to employ a method in which the mixture with the polymer is blown off with air pressure to form fibers.

On the other hand, the titania-silica fiber II having photocatalytic activity according to the present invention only needs to have the above-mentioned properties, and its production method is not particularly limited.

Next, the method for producing the composite metal oxide of the present invention is not particularly limited as long as the composite metal oxide having the above properties can be obtained. Accordingly, a desired composite metal oxide can be efficiently produced. In the method of the present invention, first, a metal organic compound or a metal inorganic compound which can induce a metal oxide having photocatalytic activity by a single crystallization treatment, and a metal which can induce a metal oxide different from the above. Using an organic compound or a metal-inorganic compound as a raw material, the average degree of polymerization is 10 to 10 by a sol-gel method.
Prepare 000 polymer.

As the metal organic compound or metal inorganic compound capable of deriving a metal oxide having photocatalytic activity, titania or zinc oxide, particularly a titanium compound capable of deriving titania, such as a compound represented by the general formula (I)
I) R ¹ nTi (OR ² ) _4-n (II) (wherein, R ¹ is an alkyl group having 1 to 10 carbon atoms, and 2 carbon atoms)
10 alkenyl group, an aryl group or an aralkyl group having 7 to 10 carbon atoms having 6 to 10 carbon atoms, R ² is 1 to the number of carbon atoms
6 is an alkyl group, if OR ² there are a plurality, each OR ²
May be the same or different, and n is 0
-3. ) Represented by a titanium compound (hereinafter, referred to as
It is called titanium alkoxide. ) Is preferably used.

Examples of the titanium alkoxide represented by the general formula (II) include tetramethoxytitanium, tetraethoxytitanium, tetra-n-propoxytitanium, tetraisopropoxytitanium, tetra-n-butoxytitanium,
Preferable examples include tetraalkoxytitanium such as tetraisobutoxytitanium, tetra-sec-butoxytitanium and tetra-tert-butoxytitanium.

On the other hand, as a metal organic compound or a metal inorganic compound capable of inducing a different kind of metal oxide, silica, alumina or zirconia, particularly a silicon compound capable of inducing silica, for example, a compound represented by the general formula (III): R ³ mSi (OR ⁴ ) _4-m (III) (wherein, R ³ is an alkyl group having 1 to 10 carbon atoms, 2 carbon atoms)
10 alkenyl group, an aryl group or an aralkyl group having 7 to 10 carbon atoms having 6 to 10 carbon atoms, R ⁴ is 1 to carbon atoms
6 is an alkyl group, if the OR ⁴ there are a plurality, each OR ⁴
May be the same or different, and m is 0
-3. ) Represented by a silicon compound (hereinafter, referred to as
It is called silicon alkoxide. ) Is preferably used.

Examples of the silicon alkoxide represented by the general formula (III) include tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetraisopropoxysilane, tetra-n-butoxysilane and tetraisobutoxysilane. Silane, tetra-sec-butoxysilane, tetra-tert-butoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane,
Propyltriethoxysilane, butyltrimethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-acryloyloxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane,
Examples thereof include dimethyldimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, divinyldimethoxylan, and divinyldiethoxysilane. Among them, tetraalkoxysilane is preferred.

In the present invention, when a titania-silicon composite is produced as a composite metal oxide, the above-mentioned titanium alkoxide and silicon alkoxide are usually hydrolyzed in an organic solvent to obtain a titania polymer and A silica polymer is prepared. At this time, a polar solvent is preferable as the organic solvent used, and a lower alcohol is particularly preferable. As the lower alcohol, for example, methyl alcohol, ethyl alcohol, n-
Propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol, n-pentyl alcohol, sec-pentyl alcohol, isopentyl alcohol, tert-pentyl alcohol, neopentyl alcohol, hexyl alcohol, 2,3-dimethyl -1-pentanol, 2,3-
Dimethyl-2-pentanol, 2-ethyl-1-butanol, 2-hexanol, 3-hexanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-methyl-3-pentanol, 3-methyl-2-
Pentanol, 3-methyl-3-pentanol, 4-methyl-1-pentanol, 4-methyl-2-pentanol and the like may be used, and these may be used alone or 2
Mixtures of more than one species may be used.

The above-mentioned titanium alkoxide or silicon alkoxide is dissolved in an appropriate concentration in this organic solvent, and while stirring, water and an acid necessary for hydrolysis are gradually added dropwise to carry out a hydrolysis reaction. . The acid used here is not particularly limited as long as it is a protonic acid that promotes hydrolysis, and examples thereof include hydrochloric acid, nitric acid, sulfuric acid, acetic acid, and oxalic acid. These may be used alone or in combination of two or more. Can also be used. This hydrolysis reaction is usually performed at a temperature in the range of 0 to 70 ° C, preferably 10 to 50 ° C. At this time, the operation is performed under reduced pressure to distill off the solvent and lower alcohol which is a by-product of the hydrolysis, thereby promoting the polycondensation of the hydrolyzate. In this reaction, the average degree of polymerization of the obtained titania polymer or silica polymer is 1 from the viewpoint of spinnability and coating property.
It is preferable to continue until it reaches 0 to 10,000.

Next, the titania polymer and the silica polymer thus obtained are mixed at an appropriate ratio, for example, the ratio of titania atoms to silica atoms is 99: 1 to 1:99, preferably 95: 5 to 30: 70, more preferably 95: 5-4
Mix at a ratio of 0:60. Next, the mixed polymer obtained as described above is fired to produce a composite metal oxide, and the firing is performed at a temperature such that the obtained composite metal oxide is in an unsintered state. . The firing temperature is appropriately selected depending on the type of metal used. For example, when producing a titania-silica composite as a composite metal oxide, baking is usually performed at a temperature in the range of 300 ° C. or more and less than 1000 ° C.

If the temperature is lower than 300 ° C., there is a possibility that an anatase type crystal form will not be exhibited and sufficient photocatalytic activity cannot be obtained. If the temperature is higher than 1000 ° C., the rutile type in the titania component increases, and the photocatalytic activity increases. And the sintered state is likely to occur. The firing temperature is preferably in the range of 400 ° C. to 950 ° C. in order to improve the photocatalytic activity and to obtain an unsintered state. The sintering time depends on the sintering temperature and cannot be determined unconditionally, but is generally 0.1 to 10%.
About an hour is enough. When the form of the obtained composite metal oxide is a film, a coating solution containing the mixed polymer is prepared, coated on a substrate to form a film, and then fired at a predetermined temperature. Good.

When fibers are used as the composite metal oxide, a spinning solution containing the mixed polymer is prepared,
Normally extruded from a nozzle with an inner diameter of 1 mm or less,
The fiber may be spun by blowing it off with an air pressure of 0.01 kgf / cm ² or more to form a fiber, and then firing the spun fibrous material at a predetermined temperature. By such a method of forming a fiber, the titania-silica fiber I or II having the photocatalytic activity can be obtained very efficiently.

[0037]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 Titanium tetraisopropoxy 113.6 under a nitrogen atmosphere
g, 13.6 g of hexyl alcohol and 4.0 g of isopropyl alcohol and, with stirring, add 13.6 g of hexyl alcohol, 4.0 g of isopropyl alcohol, 16.8 g of 36.5% by weight hydrochloric acid and 9.6 g of acetic acid. The mixed solution was dropped at a rate of one drop per second. After completion of the dropwise addition, stirring was further continued for 1 hour, and then the pressure was reduced by an aspirator to volatilize the alcohol present in the solution to promote the polycondensation of the hydrolyzed alkoxide. When the average degree of polymerization of the polymer (calculated from the number average molecular weight measured by gel permeation chromatography (GPC), the same applies hereinafter) reached 220, the depressurization was terminated to obtain a titania polymer.

On the other hand, under a nitrogen atmosphere, 83.33 g of tetraethoxysilane, 13.6 g of hexyl alcohol and 4.0 g of isopropyl alcohol were mixed, and while stirring, 13.6 g of hexyl alcohol, 4.0 g of isopropyl alcohol and 36 g of isopropyl alcohol were added. 16.8 g of 0.5% by weight hydrochloric acid
A mixed solution of acetic acid and 9.6 g was added dropwise at a rate of one drop per second. After completion of the dropping, the stirring was continued for another hour,
The pressure was reduced by an aspirator to evaporate the alcohol present in the solution to promote the polycondensation of the hydrolyzed alkoxide. When the average degree of polymerization of the polymer reached 60, the pressure reduction was terminated to obtain a silica polymer.

Next, the thus obtained titania polymer and silica polymer are mixed in a nitrogen atmosphere such that the ratio of titanium atoms to silicon atoms becomes 90:10, and the mixture is stirred for 30 minutes. Nozzle diameter 0.5 shown in FIG.
A mixture 2 of a titania polymer and a silica polymer is extruded from a 1 mm die 1 under a supply of pressurized air 3 to obtain 0.1 kg.
The fibers 4 were prepared by blow spinning at a pressure of f / cm ² , and were laminated to form a mat.

Next, the mat was dried at room temperature for 24 hours, and then heated to 750 ° C. at a rate of 100 ° C./hr.
After holding at this temperature for 2 hours, the mixture was cooled to room temperature to obtain a mat made of titania-silica composite fiber.
As a result of X-ray diffraction, it was confirmed that the fiber contained titanium dioxide in an anatase type crystal form. The average fiber diameter was found to be 8.11 μm from observation by a scanning electron microscope (SEM).
m, titania with average fiber length of 31.2 mm from magnifying glass-
It was confirmed that it was a silica composite fiber. Further, the tensile strength of the obtained fiber was measured using a tensilon, and the distance between chucks was 1
When measured under the conditions of 5 mm and a pulling speed of 20 mm / min, it was confirmed to be 0.72 GPa.

The photocatalytic activity of this titania-silica composite fiber was determined as follows. That is, the mixed polymer (spinning material) before spinning is diluted with isopropyl alcohol so as to have a viscosity of 0.1 poise (25 ° C.), and the diluted product is spin-coated on a 15 mm square silica glass plate. Was spin-coated at 3000 rpm for 30 seconds. After the coated silica glass plate was completely dried at room temperature for 24 hours, it was fired under the same conditions as the firing temperature of the fiber to produce a sample.

Each sample was irradiated with black light (irradiation intensity: 1.0 mW / cm ² ) for 2 hours to make the surface superhydrophilic, and then 5.0 × 10 ^-3 % by weight.
A methylene blue aqueous solution was spin-coated at 3000 rpm for 30 seconds, and this was naturally dried in a dark place.
Next, the initial absorbance (Abs) of the sample to which the dye was adsorbed was measured by a UV-VIS spectrophotometer (UV-2100, manufactured by Shimadzu Corporation), and the sample was further subjected to black light (irradiation intensity: 1.0 mW / cm ² ) with the spectrophotometer every 5 minutes
By examining the change in absorbance, the rate of decomposition of the dye was measured and defined as the rate of decomposition of the titania-silica fiber. The results are shown graphically in FIG. The higher the dye decomposition rate, the higher the photocatalytic activity.

Examples 2 to 5 In Example 1, instead of mixing the titania polymer and the silica polymer such that the ratio of titanium atoms to silicon atoms becomes 90:10, the ratio shown in Table 1 was used. The same operation as in Example 1 was carried out except that the mixture was mixed and calcined at a temperature at which an anatase crystal form could be confirmed. Table 1 shows the results together with the results of Example 1.

Example 6 Titanium tetraisopropoxy 113.6 under a nitrogen atmosphere
g, 13.6 g of hexyl alcohol and 4.0 g of isopropyl alcohol and, with stirring, add 13.6 g of hexyl alcohol, 4.0 g of isopropyl alcohol, 16.8 g of 36.5% by weight hydrochloric acid and 9.6 g of acetic acid. The mixed solution was dropped at a rate of one drop per second. After completion of the dropwise addition, stirring was further continued for 1 hour, and then the pressure was reduced by an aspirator to volatilize the alcohol present in the solution to promote the polycondensation of the hydrolyzed alkoxide. When the average degree of polymerization of the polymer reached 190, the depressurization was terminated to obtain a titania polymer.

On the other hand, under a nitrogen atmosphere, 54.49 g of methyltrimethoxysilane, 13.6 g of hexyl alcohol and 4.0 g of isopropyl alcohol were mixed, and while stirring, 13.6 g of hexyl alcohol, 4.0 g of isopropyl alcohol, 36.5% by weight hydrochloric acid
A mixed solution of 8 g and 4.8 g of acetic acid was dropped at a rate of one drop per second. After completion of the dropwise addition, stirring was further continued for 1 hour, and then the pressure was reduced by an aspirator to volatilize the alcohol present in the solution to promote the polycondensation of the hydrolyzed alkoxide. When the average degree of polymerization of the polymer reached 45, the pressure reduction was stopped to obtain a silica polymer.

Next, the thus obtained titania polymer and silica polymer are mixed in a nitrogen atmosphere such that the ratio of titanium atoms to silicon atoms becomes 80:20, and the mixture is stirred for 30 minutes. This mixture was extruded from a die having a nozzle diameter of 0.5 mm shown in FIG.
The fibers were produced by blow spinning at a pressure of / cm ² , and were laminated to form a mat. Next, after drying this mat at room temperature for 24 hours, 100 ° C./hr
The temperature was raised to 750 ° C. at the speed described above, and after maintaining at this temperature for 2 hours, the resultant was cooled to room temperature to obtain a mat composed of titania-silica composite fibers. Table 1 shows various measurement results.

Example 7 Titanium tetra-n-butoxide in a nitrogen atmosphere
1 g, 13.6 g of hexyl alcohol and 4.0 g of isopropyl alcohol were mixed, and while stirring, 13.6 g of hexyl alcohol, 4.0 g of isopropyl alcohol, 16.8 g of 36.5% by weight hydrochloric acid and 9.6 g of acetic acid were added thereto. The mixed solution was dropped at a rate of one drop per second. After completion of the dropwise addition, stirring was further continued for 1 hour, and then the pressure was reduced by an aspirator to volatilize the alcohol present in the solution to promote the polycondensation of the hydrolyzed alkoxide. When the average degree of polymerization of the polymer reached 190, the depressurization was terminated to obtain a titania polymer.

On the other hand, under a nitrogen atmosphere, 83.33 g of tetraethoxysilane, 13.6 g of hexyl alcohol and 4.0 g of isopropyl alcohol were mixed, and while stirring, 13.6 g of hexyl alcohol, 4.0 g of isopropyl alcohol and 36 g of isopropyl alcohol were added. 16.8 g of 0.5% by weight hydrochloric acid
A mixed solution of acetic acid and 9.6 g was added dropwise at a rate of one drop per second. After completion of the dropping, the stirring was continued for another hour,
The pressure was reduced by an aspirator to evaporate the alcohol present in the solution to promote the polycondensation of the hydrolyzed alkoxide. When the average degree of polymerization of the polymer reached 45, the pressure reduction was stopped to obtain a silica polymer.

Next, the thus obtained titania polymer and silica polymer are mixed in a nitrogen atmosphere so that the ratio of titanium atoms to silicon atoms becomes 70:30, and the mixture is stirred for 30 minutes. This mixture was extruded from a die having a nozzle diameter of 0.8 mm shown in FIG.
Fibers were produced by blow spinning at a pressure of f / cm ² , and these were laminated to form a mat. Next, after drying this mat at room temperature for 24 hours, 100 ° C./hr
The temperature was raised to 950 ° C. at a speed of 2 and held at this temperature for 2 hours, followed by cooling to room temperature to obtain a mat comprising titania-silica composite fibers. Table 1 shows various measurement results.

Example 8 Titanium tetraisopropoxy 113.6 under a nitrogen atmosphere
g, 13.6 g of hexyl alcohol and 4.0 g of isopropyl alcohol and, with stirring, add 13.6 g of hexyl alcohol, 4.0 g of isopropyl alcohol, 16.8 g of 36.5% by weight hydrochloric acid and 9.6 g of acetic acid. The mixed solution was dropped at a rate of one drop per second. After completion of the dropwise addition, stirring was further continued for 1 hour, and then the pressure was reduced by an aspirator to volatilize the alcohol present in the solution to promote the polycondensation of the hydrolyzed alkoxide. When the average degree of polymerization of the polymer reached 1000, the depressurization was terminated to obtain a titania polymer.

On the other hand, under a nitrogen atmosphere, 83.33 g of tetraethoxysilane, 13.6 g of hexyl alcohol and 4.0 g of isopropyl alcohol were mixed, and while stirring, 13.6 g of hexyl alcohol, 4.0 g of isopropyl alcohol and 36 g of isopropyl alcohol were added thereto. 16.8 g of 0.5% by weight hydrochloric acid
A mixed solution of acetic acid and 9.6 g was added dropwise at a rate of one drop per second. After completion of the dropping, the stirring was continued for another hour,
The pressure was reduced by an aspirator to evaporate the alcohol present in the solution to promote the polycondensation of the hydrolyzed alkoxide. When the average degree of polymerization of the polymer reached 200, the pressure reduction was stopped to obtain a silica polymer.

Next, the thus obtained titania polymer and silica polymer are mixed in a nitrogen atmosphere so that the ratio of titanium atoms to silicon atoms becomes 90:10, and this is mixed with isopropanol. After dilution 1.2 times, the mixture was stirred for 30 minutes. This mixture was extruded from a die having a nozzle diameter of 0.5 mm shown in FIG.
Fibers were produced by blow spinning at a pressure of m ² , and these were laminated to form a mat. Next, the mat is dried at room temperature for 24 hours, heated to 750 ° C. at a rate of 100 ° C./hr, kept at this temperature for 2 hours, and then cooled to room temperature to form a titania-silica composite fiber. I got a mat. Table 1 shows various measurement results.

Comparative Example 1 In a nitrogen atmosphere, the ratio of titanium atoms to silicon atoms was 90: 1.
113.6 so as to be 0.
g, 7.5 g of tetraethoxysilane, 13.6 g of hexyl alcohol and 4.0 g of isopropyl alcohol.
3.6 g, isopropyl alcohol 4.0 g, 36.5
A mixed solution of 16.8 g by weight of hydrochloric acid and 9.6 g of acetic acid was dropped at a rate of one drop per second. After dropping, 1 more
After stirring was continued for an hour, the pressure was reduced by an aspirator to evaporate the alcohol present in the solution to promote the polycondensation of the hydrolyzed alkoxide. When the viscosity of the polymer reached 1.0 poise (25 ° C.), the pressure reduction was terminated,
A titania silica random copolymer was obtained.

Next, this mixture was extruded from a die having a nozzle diameter of 0.5 mm shown in FIG.
Fibers were produced by blow spinning at a pressure of ² , and these were laminated to form a mat. Next, the mat is dried at room temperature for 24 hours, heated to 750 ° C. at a rate of 100 ° C./hr, kept at this temperature for 2 hours, and cooled to room temperature to obtain a titania-silica random copolymer fiber. Was obtained. Table 1 shows various measurement results. FIG. 2 is a graph showing the change over time in the dye decomposition rate.

Comparative Example 2 Tetraisopropoxy titanium 113.6 under a nitrogen atmosphere
g, 13.6 g of hexyl alcohol and 4.0 g of isopropyl alcohol and, with stirring, add 13.6 g of hexyl alcohol, 4.0 g of isopropyl alcohol, 16.8 g of 36.5% by weight hydrochloric acid and 9.6 g of acetic acid. The mixed solution was dropped at a rate of one drop per second. After completion of the dropwise addition, stirring was further continued for 1 hour, and then the pressure was reduced by an aspirator to volatilize the alcohol present in the solution to promote the polycondensation of the hydrolyzed alkoxide. When the average degree of polymerization of the polymer reached 210, the depressurization was terminated to obtain a titania polymer.

Next, this mixture was extruded from a die having a nozzle diameter of 0.5 mm shown in FIG.
Fibers were produced by blow spinning at a pressure of ² , and these were laminated to form a mat. Next, the mat is dried at room temperature for 24 hours, heated to 500 ° C. at a rate of 100 ° C./hr, kept at this temperature for 2 hours, and cooled to room temperature to obtain a mat made of titania fibers. Was. Table 1 shows various measurement results. FIG. 2 is a graph showing the change over time in the dye decomposition rate.

Comparative Example 3 In Comparative Example 1, the ratio of titanium atoms to silicon atoms was 9
The operation was performed in the same manner as in Comparative Example 1, except that tetraisopropoxytitanium and tetraethoxysilane were mixed at a ratio of 95: 5 instead of mixing tetraisopropoxytitanium and tetraethoxysilane at 0:10. Table 1 shows the results.

[0059]

[Table 1]

Note 1) The ratio of the pigment decomposition rate when the pigment decomposition rate (after irradiation with black light for 1 hour) of the titania fiber obtained in Comparative Example 2 is 100.

Note 2) Measurement is not possible because it is too weak to be chucked.

As is apparent from FIG. 2, T according to the present invention is
It can be seen that the titania-silica alloy fiber having an i / Si atomic ratio of 90/10 (Example 1) has a dye decomposition rate (photocatalytic activity) almost equivalent to that of the anatase-type titania fiber (Comparative Example 2). The titania-silica random copolymer alloy fiber having a Ti / Si atomic ratio of 90/10 (Comparative Example 1) has a considerably higher dye decomposition rate (photocatalytic activity) than the anatase-type titania fiber (Comparative Example 2). It turns out that it is low. Note that, in FIG. 2, the crosses indicate the case of silica fibers.

Example 9 Tetraisopropoxy titanium 1136 under a nitrogen atmosphere
g, hexyl alcohol 136 g and isopropyl alcohol 40 g were mixed, and while stirring, hexyl alcohol 136 g and isopropyl alcohol 40 g were added thereto.
g, a mixed solution of 168 g of 36.5% by weight hydrochloric acid and 96 g of acetic acid were slowly added dropwise over 2 hours. After dropping,
After further stirring for 1 hour, the pressure was reduced by an aspirator to remove the alcohol present in the solution, and the polycondensation of the hydrolyzed alkoxide was promoted until the average degree of polymerization reached 200 to obtain a titania polymer. .

Separately, under a nitrogen atmosphere, 833 g of tetraethoxysilane and 136 g of ethyl alcohol were mixed.
While stirring, add 136 g of ethyl alcohol, 3
A mixed solution of 168 g of 6.5% by weight hydrochloric acid and 96 g of acetic acid was slowly dropped over 2 hours. After completion of the dropwise addition, stirring was further continued for 1 hour, and then the pressure was reduced with an aspirator to remove the alcohol present in the solution, and the polycondensation of the hydrolyzed alkoxide was promoted until the average degree of polymerization reached 50, and the silica polymerization was started. I got something.

The titania polymer and the silica polymer were stirred and mixed for 30 minutes so that the ratio of titanium atoms to silicon atoms was 80:20. The resulting mixture is
Dry in oven at 24 ° C. for 24 hours. After calcination of this mixture at various temperatures, X-ray diffraction was measured, and the crystallization temperature of anatase of titanium oxide was determined.
The content of anatase by calcination at 0 ° C. was 45% with respect to the titania component. The FT of this 500 ° C fired product
-IR (FT300 manufactured by HORIBA) was measured, and the absorption attributed to titanosiloxane (Ti-O-Si) was observed at around 970 cm ^-1 , indicating that both mixed components were chemically bonded. Was.

The mixture was diluted 50-fold with isopropyl alcohol and applied to a quartz glass substrate.
It was baked at 0 ° C. When the pencil hardness of the obtained film was measured, it was 5H. This was irradiated with ultraviolet rays from a 20 W black light at an intensity of 1.0 mW / cm ² for one day.
A 5.0 × 10 ⁻³ wt% aqueous solution of methylene blue was spin-coated on this film at 3000 rpm for 30 seconds, and air-dried in a dark place. The initial absorbance (abs) of the sample to which the dye was adsorbed was measured with a UV-VIS spectrophotometer, and the sample was further irradiated with ultraviolet light from a black light at an intensity of 1.0 mW / cm ² , and the initial dye decomposition rate ( The amount of decrease in absorbance per unit time) was determined to be 0.312 / hr, indicating a high photocatalytic activity.

Comparative Example 4 1136 g of tetraisopropoxytitanium in a nitrogen atmosphere
(4 mol), 208.33 g of tetraethoxysilane
(1 mol), 170 g of hexyl alcohol and 50 g of isopropyl alcohol, and while stirring, 170 g of hexyl alcohol, 50 g of isopropyl alcohol, 210 g of 36.5 wt% hydrochloric acid and acetic acid 1
20 g of the mixed solution was slowly added dropwise over 2 hours. After completion of the dropwise addition, stirring was further continued for 1 hour, the pressure was reduced by an aspirator to remove the alcohol present in the solution, and the polycondensation of the hydrolyzed alkoxide was carried out at an average degree of polymerization of 20.
The reaction was promoted to 0 to obtain a copolymer of titania and silica. This was dried in a 40 ° C. oven for 24 hours. After firing this mixture at various temperatures, X-ray diffraction was measured and the crystallization temperature of titanium oxide anatase was determined.
The temperature was 0 ° C., and the content of anatase by calcination at 800 ° C. was 12% with respect to the titania component.

The above copolymer was diluted 50-fold with isopropyl alcohol and applied to a quartz glass substrate.
It was baked at 00 ° C. When the pencil hardness of the obtained film was measured, it was 5H. This was irradiated with ultraviolet rays from a 20 W black light at an intensity of 1.0 mW / cm ² for one day. A 5.0 × 10 ⁻³ wt% aqueous solution of methylene blue was spin-coated on this film at 3000 rpm for 30 seconds, and air-dried in a dark place. The initial absorbance (abs) of the sample to which the dye was adsorbed was measured with a UV-VIS spectrophotometer, and the sample was further irradiated with ultraviolet light from a black light at an intensity of 1.0 mW / cm ² , and the initial dye decomposition rate ( When the amount of decrease in absorbance per unit time) was determined, it was 0.083 / hr, indicating a low photocatalytic activity.

Comparative Example 5 Silica sol (trade name: A of synthetic glass "Glaska" of Japan)
Liquid), trimethoxymethylsilane (the same liquid B) and anatase-type titania sol (Nissan Chemical TA-15, average diameter 12n)
m) was mixed in a weight ratio of 3: 1: 4, and the mixture was applied on quartz glass. This was cured at a temperature of 150 ° C. When the pencil hardness of the obtained film was measured, it was 2H. 1
When the FT-IR of the product cured at 50 ° C. was measured,
No absorption attributed to titanosiloxane (Ti-O-Si) was observed around 970 cm ^-1 , indicating that both components were not chemically bonded. This was irradiated with ultraviolet rays from a 20 W black light at an intensity of 1.0 mW / cm ² for one day. A 5.0 × 10 ⁻³ wt% aqueous solution of methylene blue was spin-coated on this film at 3000 rpm for 30 seconds, and air-dried in a dark place. The initial absorbance (abs) of the sample to which this dye was adsorbed was determined by UV-VIS
The sample was irradiated with ultraviolet light from a black light at an intensity of 1.0 mW / cm ² , and the initial dye decomposition rate (decrease in absorbance per unit time) was determined to be 0.248. / Hr, indicating high photocatalytic activity.

On the other hand, the quartz glass with the coating film
It was baked at 0 ° C. for 5 hours, and the pencil hardness of the film was measured. This was irradiated with ultraviolet rays from a 20 W black light at an intensity of 1.0 mW / cm ² for one day.
A 5.0 × 10 ⁻³ wt% aqueous solution of methylene blue was spin-coated on this film at 3000 rpm for 30 seconds, and air-dried in a dark place. The initial absorbance (abs) of the sample to which the dye was adsorbed was measured with a UV-VIS spectrophotometer, and the sample was further irradiated with ultraviolet light from a black light at an intensity of 1.0 mW / cm ² , and the initial dye decomposition rate ( The amount of decrease in absorbance per unit time) was determined to be 0.068 / hr, indicating a low photocatalytic activity.

Example 10 In a nitrogen atmosphere, 144.2 g (1 mol) of monoisopropoxydiethylaluminum was dissolved in 600 ml of ethyl ether, and 18 g (1 mol) of water was added to carry out hydrolysis. An organoaluminoxane was obtained. This was mixed with the titania polymer of Example 9 having a degree of polymerization of 200 so that the aluminum: titanium atomic ratio was 20:80. After the obtained mixture was dried in an oven at 40 ° C. for 24 hours, it was calcined at various temperatures, and then X-ray diffraction was measured. The phase transition temperature to anatase was 400 ° C. The content of anatase was 50% of the titania component. This polymer was diluted 50-fold with isopropyl alcohol, applied to a quartz glass substrate, and baked at 500 ° C. When the pencil hardness of the obtained film was measured, it was 4H. UV light from a 20W black light
Irradiation was performed at an intensity of mW / cm ² for one day. 4. On this film
0 × 10 ^-3 wt% methylene blue aqueous solution
It was spin-coated at pm for 30 seconds and air-dried in the dark. The initial absorbance (abs) of the sample to which the dye was adsorbed was measured with a UV-VIS spectrophotometer, and the sample was further irradiated with ultraviolet light from a black light by 1.0 mW.
/ Cm ² , and the initial dye decomposition rate (decrease in absorbance per unit time) was determined to be 0.29
8 / hr, indicating a high photocatalytic activity.

Example 11 Diethoxyzinc 4 was added to a flask equipped with a reflux tube under a nitrogen atmosphere.
6.65 g (0.3 mol) of n-butanol 741.
2 g (10 mol) and 90.10 acetylacetone
8 g (0.9 mol) was added, and a separately prepared solution of 1.35 g (0.075 mol) of distilled water, 31.542 g (0.3 mol) of diethanolamine and 370.6 g (5 mol) of n-butanol was added to the solution. It was dripped slowly. After the completion of the dropwise addition, the mixture was heated at 100 ° C. for 10 hours.
After allowing to cool, the molecular weight was measured by GPC and found to be 400. The silica polymer of Example 9 was added to this solution so that the atomic ratio of zinc: silicon was 70:30.
Mix evenly. This mixture was diluted 10-fold with isopropyl alcohol to prepare a coating solution, applied to a quartz glass substrate, and fired at 600 ° C. When the pencil hardness of the obtained film was measured, it was 5H. UV light from a 20 W black light was applied at an intensity of 1.0 mW / cm ^2.
Irradiated for days. A 5.0 × 10 ⁻³ wt% aqueous solution of methylene blue was spin-coated on this film at 3000 rpm for 30 seconds, and air-dried in a dark place. The initial absorbance (abs) of the sample to which this dye was adsorbed was determined by UV-VI
The sample was irradiated with ultraviolet light from a black light at an intensity of 1.0 mW / cm ² , and the initial dye decomposition rate (decrease in absorbance per unit time) was determined. 201 / hr, indicating a high photocatalytic activity.

REFERENCE EXAMPLE In a nitrogen atmosphere, 144.2 g (1 mol) of monoisopropoxydiethylaluminum was dissolved in 600 ml of ethyl ether, and 18 g (1 mol) of water was added to carry out hydrolysis. Aluminoxane was obtained. This was mixed with the silica polymer of Example 9 having a polymerization degree of 50 so that the atomic ratio of aluminum: silicon was 60:40. The resulting mixture is
After drying in an oven at 0 ° C. for 24 hours, X-ray diffraction was measured after firing at various temperatures, and the phase transition temperature to γ-alumina was determined. The content of γ-alumina was 40%. This polymer is treated with isopropyl alcohol for 50 minutes.
It was diluted twice and applied to a quartz glass substrate, and baked at 400 ° C. When the pencil hardness of the obtained film was measured, it was 5H.

[0074]

The composite metal oxide of the present invention is obtained by chemically bonding a polymer block of a metal oxide having photocatalytic activity to a polymer block of another heterometal oxide,
In addition to having good photocatalytic activity and superhydrophilicity, it has excellent mechanical strength, and can be used in various applications as a film-like material or fiber, or a mat-like material such as a mat, woven fabric, or non-woven fabric.

According to the method of the present invention, the composite metal oxide can be produced efficiently and industrially advantageously.

[Brief description of the drawings]

FIG. 1 is a schematic view of a die used for spinning in Examples and Comparative Examples.

FIG. 2 is a graph showing the pigment decomposition rate of each fiber obtained in Example 1 and Comparative Examples 1 and 2.

[Description of Signs] 1 Dice 2 Mixture of silica polymer and titania polymer 3 Pressure air 4 Fiber

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C01G 25/00 C01G 25/00 D04H 1/42 D04H 1/42 A D21H 13/46 D21H 13/46 // D03D 15/00 D03D 15/00 A 15/12 15/12 Z

Claims (15)

[Claims] (A) An average degree of polymerization of 10 to 1 obtained from a metal organic compound or a metal inorganic compound capable of deriving a metal oxide having photocatalytic activity by a single crystallization treatment.
A non-sintered state of a mixture comprising a polymer of 0000 and (B) a polymer having an average degree of polymerization of 10 to 10000 obtained from a metal organic compound or a metal inorganic compound capable of inducing a metal oxide different from the above. (A)
A composite metal oxide, wherein a polymer block of a metal oxide derived from a polymer and a polymer block of a metal oxide derived from the polymer (B) are chemically bonded. 2. The composite metal oxide according to claim 1, wherein the fired product is obtained by firing a film formed from a mixture of a polymer (A) and a polymer (B) provided on a substrate. . 3. The composite metal oxide according to claim 1, wherein the fired product is obtained by firing a fibrous material obtained by spinning a mixture of a polymer (A) and a polymer (B). 4. The composite metal oxide according to claim 3, wherein the fired product is a web obtained by processing a fired fibrous material. 5. A metal oxide having photocatalytic activity by a single crystallization treatment is titania and / or zinc oxide, and a different metal oxide different from the above is silica,
At least one selected from alumina and zirconia
The composite metal oxide according to any one of claims 1 to 4, which is a seed. 6. The composite metal oxide according to claim 5, wherein the metal oxide having photocatalytic activity by a single crystallization treatment is titania, and the different metal oxide different from the above is silica. 7. A photocatalytic activity mainly comprising a calcined product of a fibrous material obtained by spinning a mixture of a titania polymer and a silica polymer by a sol-gel method, wherein the titania component mainly comprises an anatase type crystal form. The composite metal oxide according to claim 3, wherein the composite metal oxide is a titania-silica fiber. 8. A titania-silica fiber having photocatalytic activity is obtained by using a method of spinning a mixture of a titania polymer and a silica polymer by a sol-gel method and blowing the mixture with air pressure to form a fiber. The composite metal oxide according to claim 7. 9. The titania-silica fiber having photocatalytic activity has an average fiber diameter of 20 μm or less and an average fiber length of 1 mm.
The composite metal oxide according to claim 7 or 8, wherein the tensile strength of the single fiber fiber is 0.5 GPa or more. 10. In a pigment decomposition test using methylene blue, the decomposition rate of titania single fiber after 60 minutes was determined to be 10%.
When 0% is set, the decomposition rate A% after 60 minutes is represented by the formula (I) A (%) ≧ [the number of titanium atoms in the fiber / the total number of titanium atoms and silicon atoms in the fiber] × 100. The composite metal oxide according to claim 3 or 6, which is a titania-silica fiber having photocatalytic activity satisfying the relationship of (I). 11. The composite metal oxide according to claim 7, which is a mat-like material composed of titania-silica fibers having photocatalytic activity. 12. A metal organic compound or a metal inorganic compound capable of inducing a metal oxide having photocatalytic activity by a single crystallization treatment, and a metal organic compound or metal capable of inducing a metal oxide different from the above. The production of a composite metal oxide according to claim 1, wherein a polymer having an average degree of polymerization of 10 to 10000 is obtained by a sol-gel method using an inorganic compound as a raw material, and then the mixture is mixed and fired. Method. 13. General formula (II) R ¹ nTi (OR ² ) _4-n (II) (wherein, R ¹ is an alkyl group having 1 to 10 carbon atoms, 2 carbon atoms)
10 alkenyl group, an aryl group or an aralkyl group having 7 to 10 carbon atoms having 6 to 10 carbon atoms, R ² is 1 to the number of carbon atoms
6 is an alkyl group, if OR ² there are a plurality, each OR ²
May be the same or different, and n is 0
-3. And a general formula (III) R ³ mSi (OR ⁴ ) _4-m (III) (wherein R ³ is an alkyl group having 1 to 10 carbon atoms, 2 carbon atoms)
10 alkenyl group, an aryl group or an aralkyl group having 7 to 10 carbon atoms having 6 to 10 carbon atoms, R ⁴ is 1 to carbon atoms
6 is an alkyl group, if the OR ⁴ there are a plurality, each OR ⁴
May be the same or different, and m is 0
-3. ) Is used as a raw material, and each has a degree of polymerization of 10 to 10
13. The method according to claim 12, wherein after obtaining 000 titania polymer and silica polymer, the mixture is spun and then calcined to obtain titania-silica fiber having photocatalytic activity. 14. The method according to claim 13, wherein the titanium compound represented by the general formula (II) is a tetraalkoxytitanium, and the silicon compound represented by the general formula (III) is a tetraalkoxysilane. 15. A fiber spinning method comprising blowing a mixture of a titania polymer and a silica polymer by a sol-gel method with air pressure to produce a fiber.
4. The method according to 4.