JP2000220038A - Method for producing titania fiber containing catalyst component - Google Patents

Abstract

(57) [Problem] It can be used for reduction of nitrogen oxides, oxidation of organic substances, decomposition of organic chlorinated compounds such as dioxins, decomposition and removal of organic solvents, pesticides and surfactants, etc. Provided is a method for producing a catalyst component-containing titania fiber having a specific surface area and a pore volume and exhibiting high activity. SOLUTION: Water is added to a solution in which a titanium alkoxide is dissolved in a solvent to carry out a hydrolysis reaction and a polymerization reaction to form a polymer in the solution, and the polymer is dissolved in an organic solvent in which the polymer is soluble. To obtain a spinning solution, spinning the spinning solution to obtain a precursor fiber, and calcining the precursor fiber.
Or obtaining a spinning solution by spinning the spinning solution, and subjecting the precursor fiber obtained by spinning the spinning solution to steam treatment before and / or during firing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing titania fibers containing a catalyst component. More specifically, the present invention relates to a method for producing a titania fiber containing a catalyst component used for reducing nitrogen oxides, oxidizing organic substances, decomposing dioxins, and decomposing and removing organic solvents, pesticides, surfactants, and the like.

[0002]

2. Description of the Related Art Heretofore, as a method for producing titania fiber containing a catalyst component, a sol-gel in which a titanium alkoxide and a vanadium compound or a mixed alkoxide solution of a titanium alkoxide and a vanadium compound and another alkoxide is hydrolyzed and gelled. A method in which amorphous fibers produced by the method are heat-treated to precipitate crystals of anatase-type titanium oxide and vanadium oxide (for example,
Japanese Patent Application Laid-Open No. 5-184923) or a method in which a polymer comprising titanium and silicon is formed by a sol-gel method using an organic alkoxide of titanium and silicon as a raw material, then spun into a fiber, and the fiber is dried and fired. There is known a method of obtaining a fiber composed of titanium oxide-silica and then carrying vanadium oxide and / or tungsten oxide (for example, JP-A-6-134306).

[0003]

However, according to the above-mentioned known methods as described above, titania fibers containing a catalyst component having a sufficient specific surface area and a sufficient pore volume cannot be obtained.
There is a problem that the performance of reducing nitrogen oxides, oxidizing organic substances, decomposing dioxins, and decomposing and removing organic solvents, pesticides, surfactants and the like in water is low.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, added water to a solution in which a titanium alkoxide was dissolved in a solvent to carry out a hydrolysis reaction and a polymerization reaction. Performing a polymer in the solution, dissolving the polymer in an organic solvent in which the polymer is soluble to obtain a spinning solution, and spinning the spinning solution to obtain a precursor fiber,
In the method for producing titania fiber in which the precursor fiber is fired, when a catalyst component is added under specific conditions and the obtained precursor fiber is processed under specific conditions, an unprecedented large specific surface area and pore volume It has been found that titania fibers containing a catalyst component having high activity and having high activity can be obtained, and the present invention has been completed.

That is, in the present invention, a hydrolysis reaction and a polymerization reaction are performed by adding water to a solution in which a titanium alkoxide is dissolved in a solvent, and a polymer is generated in the solution. In a method for producing a titania fiber in which a spinning solution is dissolved in a soluble organic solvent to obtain a spinning solution, the spinning solution is spun to obtain a precursor fiber, and the precursor fiber is calcined, a catalyst component is added to the step and / or step. It is another object of the present invention to provide a method for producing a titania fiber containing a catalyst component, which comprises obtaining a spinning solution and subjecting a precursor fiber obtained by spinning the spinning solution to steam treatment before and / or during firing.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. In the process of the present invention, a hydrolysis reaction and a polymerization reaction are performed by adding water to a solution in which a titanium alkoxide is dissolved in a solvent (hereinafter, sometimes referred to as a titanium alkoxide solution), and a polymer is generated in the solution. It is a process.

[0007] Titanium alkoxide has the general formula [1] Ti (O
R₁)_Four(Where R₁Is an alkyl having 1 to 4 carbon atoms
Which represents a hydroxyl group). More specifically, titanium tetra
Methoxide, titanium tetraethoxide, titanium tetra n
-Propoxide, titanium tetra-iso-propoxide,
Titanium tetra n-butoxide, titanium tetra sec-butyl
Toxide, titanium tetra tert-butoxide and the like.
But R ₁Is an isopropyl group
Liso-propoxide. Of the general formula [1]
R₁When the number of carbon atoms exceeds 4 in the resulting polymer
Of residual titanic fiber
Mechanical strength tends to be low.

[0008] The solvent only needs to dissolve the titanium alkoxide, and examples thereof include alcohols, ethers, and aromatic hydrocarbons. Alcohols have the general formula [2] R ₂ OH
(Wherein, R ₂ represents an alkyl group having 1 to 4 carbon atoms), and specific examples include ethanol and isopropyl alcohol. Specific examples of ethers include tetrahydrofuran, diethyl ether and the like. The amount of the solvent with respect to the titanium alkoxide may be such that the alkoxide and water are not immiscible during the hydrolysis, and is usually in the range of about 0.5 mol to about 50 mol per 1 mol of the titanium alkoxide. There is no particular problem if the amount of the solvent exceeds about 50 mol, but the cost of concentrating the polymer in the subsequent step is increased.

[0009] The water is preferably the same solvent as that in which the titanium alkoxide is dissolved and diluted to a water concentration of about 1 to about 50% by weight. When water having a water concentration of more than 50% by weight is directly added to the titanium alkoxide solution, the reaction locally proceeds, and a polymer insoluble in the spinning solution may be precipitated during spinning in a later step. The amount of water to be added is usually about 1 to 1 mole of titanium alkoxide.
The amount is in the range of 5 mol to about 4 mol, but the amount of water added is not necessarily limited. The amount of water is determined by determining the amount of water added to the titanium alkoxide solution (A) and discharging the titanium alkoxide solution out of the reaction system from the time when the polymer is formed by adding water to the time when the spinning solution is obtained. Difference (AB) from the amount of water (B), ie, the amount of water substantially consumed in the hydrolysis reaction is about 1.5 mol to about 1.95 mol per 1 mol of titanium alkoxide; Preferably, the amount is about 1.6 mol to 1.90 mol. If the amount of water discharged out of the reaction system is large,
The amount of water to be added may be increased. When the difference in the amount of water (AB), that is, the amount of water substantially consumed in the hydrolysis reaction is less than about 1.5 mol, the degree of polymerization of the obtained polymer is small, and It becomes a polymer having a high organic matter content, and the mechanical strength of the obtained titania fiber tends to be low. On the other hand, the difference in the amount of water (AB)
If it exceeds 1.95 mol, the resulting polymer will be poorly soluble in organic solvents, and the resulting titania fibers will tend to have low mechanical strength. In producing the titania fiber of the present invention, when the amount of the water to be added is appropriate, particularly, the obtained polymer has a high degree of polymerization and has many titanium-oxygen-titanium bonds, As a result, the content of organic matter is low, and the titania fiber obtained by spinning this polymer has high mechanical strength.

In practicing the present invention, a titanium alkoxide solution is prepared by dissolving titanium alkoxide in a solvent and refluxing in an inert atmosphere such as a nitrogen atmosphere. By adding water to the titanium alkoxide solution, a hydrolysis reaction and a polymerization reaction are performed to generate a polymer in the solution. When the produced polymer precipitates in the solution, the solvent may be removed or partially removed, and then the concentration of the spinning solution may be adjusted. On the other hand, when the produced polymer does not precipitate in the solution, the procedure may be shifted to the concentration adjustment of the spinning solution. From an industrial viewpoint, it is preferable that the concentration of the titanium alkoxide solution is high. Therefore, refluxing the titanium alkoxide solution under boiling, while distilling the same volume of the solvent contained in the water to be added, while adding water to the titanium alkoxide solution, the amount of solvent in the solution due to the increase in the amount of solvent This method is industrially recommended because a decrease in titanium (Ti) concentration can be suppressed.

The step of the present invention is a step of dissolving the polymer in an organic solvent in which the polymer is soluble to obtain a spinning solution.

The organic solvent may be titanium alkoxide or, in the case of adding a catalyst component, any solvent capable of dissolving both the metal compound as the catalyst component and the titanium alkoxide, such as alcohols such as ethanol and isopropyl alcohol, and tetrahydrofuran. And ethers such as diethyl ether, and aromatic hydrocarbons such as benzene and toluene.

In practicing the present invention, the polymer or the polymer slurry is dissolved in an organic solvent to prepare a polymer solution, and then concentrated by removing the organic solvent by heating or removing the organic solvent by reduced pressure. , The concentration of the polymer is about 50
It is adjusted to be about 80% by weight to about 80% by weight. The spinning solution generally has a viscosity of about 10 poise to about 2000 poise,
Preferably, it should be in the range of about 20 poise to about 1500 poise. The viscosity of the spinning solution can be controlled by adjusting the concentration of the polymer and the temperature of the spinning solution.

In the present invention, the catalyst component is subjected to a hydrolysis reaction and a polymerization reaction by adding water to a solution obtained by dissolving a titanium alkoxide in a solvent to form a polymer in the solution. The step of dissolving the coalesced compound in an organic solvent in which the polymer is soluble to obtain a spinning solution.

The catalyst components are V, W, Al, As, Ni, Z
It is composed of at least one metal compound selected from the group consisting of r, Mo, Ru, Mg, Ca, Fe, Cr and Pt. The metal compound may be any one that is soluble in a titanium alkoxide solution and an organic solvent. Tungsten compounds such as tungsten, aluminum compounds such as alkylaluminum and aluminum alkoxide, arsenic compounds such as arsenic chloride, nickel compounds such as nickel alkoxide and nickel chloride, zirconium alkoxide, zirconium acetylacetonate, zirconium butoxyacetylacetonate, zirconium tetrabutoxide Such as zirconium compounds, molybdenum oxyacetylacetonate,
Molybdenum compounds such as molybdenum chloride; ruthenium compounds such as ruthenium chloride; magnesium compounds such as magnesium alkoxide, magnesium acetylacetonate and magnesium chloride; calcium compounds such as calcium alkoxide and calcium chloride; iron alkoxides; iron acetylacetonate; Iron compounds, chromium compounds such as chromium alkoxide and chromium acetylacetonate, and platinum compounds such as platinum acetylacetonate and platinum chloride. The addition amount of the metal compound varies depending on the use of the catalyst component-containing titania fiber and is not unique, but is not limited to about 0.001% by weight in terms of oxide.
50% by weight. If the amount is less than about 0.001% by weight, it is difficult to obtain sufficient catalytic activity, and if the amount is more than about 50% by weight, no catalytic activity commensurate with the amount is obtained.

[0016] The catalyst component is added to a titanium alkoxide solution, to a solution obtained by adding water to the titanium alkoxide solution and subject to hydrolysis and polymerization, or to a spinning solution. And so on.

The step of the present invention is a step of spinning the spinning solution to obtain a precursor fiber.

The spinning is not particularly limited, and known spinning methods such as nozzle extrusion spinning, centrifugal spinning, and blow spinning can be applied. At the time of spinning, the precursor fiber can be drawn by a rotating roller or a high-speed air stream. In spinning, adjusting the spinning atmosphere and the temperature and humidity of the blown air is a desirable method for stably obtaining good fibers.

The step of the present invention is a step of firing the precursor fiber.

The firing is not particularly limited, and may be performed by a known method. The calcination temperature is not particularly limited since it varies depending on the use of the catalyst and is related to the steam treatment conditions, but is usually in the range of about 300 ° C to about 900 ° C. As the firing temperature is higher, the porosity, that is, the BET specific surface area and the pore volume tend to decrease, but as the steam treatment conditions,
The higher the temperature and the higher the temperature, the higher the porosity is maintained even at a high firing temperature. If the calcination temperature is lower than about 300 ° C., the crystallinity is not sufficient because sufficient catalytic activity cannot be obtained. If the calcination temperature is higher than about 900 ° C., the porosity is lost and the catalytic activity is significantly reduced. Further, the firing may be performed by applying tension to the precursor fiber.

[0021] The present invention is characterized in that the precursor fibers are subjected to steam treatment before and / or during firing.

[0022] The steam treatment may be performed using a known device such as a thermo-hygrostat or a baking furnace.
0 ° C. to about 300 ° C., preferably about 85 ° C. to about 300 ° C., a partial pressure of steam of about 0.3 atm or more, preferably about 0.5 atm or more, and a contact time of 30 minutes or more, preferably The time is at least 1 hour, more preferably at least 5 hours.
The higher the temperature and the partial pressure of steam, the shorter the processing time. When the processing temperature is lower than 70 ° C., a long-time processing is required. Also, when the partial pressure of water vapor is lower than 0.3 atm, a long time treatment is also required.

In the case of performing steam treatment at the time of calcination, the treatment may be performed by adjusting the temperature rising rate while maintaining a predetermined humidity by a method of blowing steam into a calcination furnace or the like or a method of spraying water. In this case, it is sufficient that the precursor fiber can be maintained for at least 30 minutes in an atmosphere having a water vapor partial pressure of 0.3 atm or more between about 70 ° C. and about 300 ° C. May be.

Although the titania fiber containing a highly active catalyst component can be obtained by the above-described production method, high mechanical strength is added by a method of adding a compound having active hydrogen and / or a method of adding silica. It is also possible to obtain titania fibers containing a catalyst component. In particular, a catalyst component-containing titania fiber having a large pore volume of 10 ° or more can be obtained by the method of adding a compound having active hydrogen, and the performance of reducing nitrogen oxides and decomposing organic substances can be further improved. , Its application is recommended.

As a specific example of the method of adding a compound having active hydrogen, there is a method of adding a compound having active hydrogen to a titanium alkoxide solution and then adding water to carry out hydrolysis and polymerization reaction. By adding an appropriate amount of the compound having active hydrogen, the hydrolysis reaction and the polymerization reaction of the titanium alkoxide can be controlled, and the solubility of the polymer formed in the solution in an organic solvent can be improved. Examples of the compound having active hydrogen include β represented by the general formula [3] R ₃ COCH ₂ COR ₄ (wherein R ₃ and R ₄ represent an alkyl group or an alkoxy group having 1 to 4 carbon atoms). -Diketone compounds or alkyl salicylates are preferred. More specifically, as the β-diketone compound, ethyl acetoacetate and isopropyl acetoacetate, and as the alkyl salicylate,
The use of ethyl salicylate, methyl salicylate and the like is recommended. The addition amount of the compound having active hydrogen is about 0.05 to about 1.9 mol per 1 mol of titanium alkoxide,
Preferably it is from about 0.1 to about 1.0 mole. When the amount is less than about 0.05 mol, no effect is observed. When the amount is more than 1.9 mol, the hydrolysis and the polymerization reaction are excessively suppressed and the polymerization hardly progresses. The amount of residual organic matter in the resulting polymer also increases, and the resulting fiber may have low mechanical strength.

Specific examples of the method of adding silica include a method of adding a silicon compound to a titanium alkoxide solution, a method of adding a silicon compound to a solution obtained by hydrolyzing and polymerizing a titanium alkoxide solution, or There is a method of adding a silicon compound to the spinning solution. The silicon compound is not particularly limited as long as it can be uniformly mixed and dispersed in a titanium alkoxide solution and an organic solvent, but is usually represented by the general formula [4] Si _n O _n-1 (OR ₅ ) _{2n + 2} (however, Wherein R ₅ represents an alkyl group having 1 to 4 carbon atoms, and n represents 1
It is preferable to use an alkyl silicate represented by the above number). Particularly preferred alkyl silicates are those in which R ₅ in the general formula [4] is an ethyl group,
Is 4 to 6 and ethyl silicate. The amount of the silicon compound added is such that the silica content in the catalyst component-containing titania fiber obtained after firing is about 1 to about 40% by weight, preferably about 5 to about 30% by weight. If the silica content exceeds 40% by weight, not only the mechanical strength of the resulting fiber is no longer high, but also the catalytic activity is reduced due to the relative decrease in the proportion of the catalyst component.

The BET specific surface area is at least 10 m ² / g, preferably at least 50 m ² / g, more preferably at least 100 m ² / g according to the production method described in detail above. The volume is 0.05 cc / g or more, preferably 0.1 cc / g or more, and more preferably 0.15 c / g.
c / g or more and a pore volume having a pore radius of 10 ° or more is 0.02 cc / g or more, preferably 0.04 cc or more.
/ G or more, more preferably 0.1 cc / g or more, can be obtained.

The titania fiber containing the catalyst component usually has a fiber diameter of about 5 μm to about 50 μm and a fiber length of about 50 μm.
cm or more, and the tensile strength of the single fiber is about 0.1 GPa or more, preferably 0.3 GPa or more.

Hazardous substances using catalyst component-containing titania fibers obtained by the method of the present invention (for example, nitrogen oxides, organic substances, organic chlorine compounds such as dioxin and monochlorobenzene, organic solvents, pesticides, surfactants, etc.) As a treatment method, for example, there is a method of contacting a harmful substance to the fiber, as a specific example, a reaction tube filled with the fiber,
A method of flowing a nitrogen oxide, an organic substance, or an organic chlorine-based compound may, for example, be mentioned. As the temperature at the time of contact (temperature of the reaction tube or the like) increases, the effect of removing harmful substances increases. The temperature varies depending on the type and concentration of the organic substance to be treated and is not unique, but is usually about 150 ° C.
Above, preferably about 200 ° C. or higher.

[0030]

The titania fiber containing the catalyst component obtained by the present invention has an unprecedented large specific surface area and pore volume and is highly active, so that it can reduce nitrogen oxides, oxidize organic substances, and dioxin. Its industrial utility as a catalyst for decomposing organic chlorinated compounds and decomposing and removing organic solvents, agricultural chemicals and surfactants is extremely large.

[0031]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention. In the present invention, the BET specific surface area, pore volume, tensile strength, and denitration rate of the titania fiber containing the catalyst component were measured by the following methods.

BET specific surface area (m ² / g): The fiber is lightly pulverized in a mortar and vacuum degassed (1) using a gas adsorption / desorption analyzer Omnisorp 360 (manufactured by COULTER).
After 30 ° C., 6 hours, degree of vacuum: 6 × 10 ⁻⁵ Torr or less), the measurement was performed by a continuous volume method using nitrogen gas.

[0033] Pore volume (cc / g): The fiber is lightly ground in a mortar, and a gas adsorption / desorption analyzer Omnisorp 36 is used.
0 (manufactured by COULTER) and vacuum degassing (130
C., 6 hours, degree of vacuum: 6 × 10 ⁻⁵ Torr or less), and the total pore volume and the pore volume having a pore radius of 10 ° or more were measured by a continuous volume method using nitrogen gas.

[0034] Tensile strength (GPa): A single fiber automatic tensile tester (manufactured by Toyo Baldwin Co., Ltd., control unit;
Model AMF-C, tension unit; TENSILON, U
Using TM-2-20), the fiber was pulled at a measurement length of 25 mm and a tensile speed of 1 mm / min, and the strength at which the fiber was broken was measured. The measured value is the average value of the tensile strength of 30 single fibers.

Denitration ratio (%): After filling 0.5 g of fiber into a glass reaction tube having an inner diameter of 12 mmφ so that the filling height becomes 5 mm, NO: 100 ppm, NH ₃ :
A gas at 200 ° C. containing 100 ppm and O ₂ : 10% was passed at a flow rate of 1 L / min, and the NO concentration at the inlet and the NO concentration at the outlet of the reaction tube were measured by an automatic NOx measuring device ECL-77A (manufactured by Yanagimoto Seisakusho). . The denitration rate was determined by the following equation. Denitration rate (%) = (NO concentration at inlet-NO concentration at outlet) / NO concentration at inlet × 100

Example 1 300.0 g of titanium tetraiso-propoxide (first grade reagent, manufactured by Wako Pure Chemical Industries) as a titanium alkoxide and ethyl acetoacetate (special grade reagent, manufactured by Wako Pure Chemical Industries) 55 as a compound having active hydrogen 55 2.0 g of isopropyl alcohol as a solvent (special grade reagent, manufactured by Wako Pure Chemical Industries) 7
The titanium alkoxide was dissolved in 3.6 g and refluxed for 1 hour under a nitrogen atmosphere to prepare a titanium alkoxide solution. At this time, the molar ratio of ethyl acetoacetate to titanium isopropoxide is 0.40. 36.0 g of water was mixed with 324.8 g of isopropyl alcohol to prepare a water having a water concentration of 10% by weight. The amount of the water is 1.9 mol per 1 mol of titanium alkoxide.

At the same time, the titanium alkoxide solution was heated in a nitrogen atmosphere and refluxed under boiling, and at the same time, while distilling off the solvent, water was added with stirring. The distillation rate of the solvent and the supply rate of the solvent by adding water were adjusted to be substantially equal, and the addition time was adjusted to be 103 minutes.

[0038] From the time when the addition was started and 1.8 moles of water was added to 1 mole of titanium alkoxide, the precipitation of the polymer started, and when the entire amount of water was added, the polymer was completely in a slurry state. Was.

After refluxing the slurry for 1 hour, the solvent was distilled off by heating as it was, and the Ti concentration was 3.46 ×
It was concentrated to 10 ⁻³ mol / g. The amount of water discharged out of the system by the operation up to this point was 0.14 mol per 1 mol of titanium alkoxide. Therefore, the difference between the amount of water added and the amount of water discharged out of the system together with the solvent or the like is 1.76 with respect to 1 mol of titanium alkoxide.
It was a molar amount.

352 g of tetrahydrofuran (special grade reagent, manufactured by Wako Pure Chemical Industries, Ltd.) was added to the slurry as an organic solvent.
After refluxing to dissolve the polymer, triethoxyvanadyl (manufactured by Kojundo Chemical Co.) was used as a catalyst component.
2 g was added, and the mixture was further refluxed for 1 hour. The amount of the catalyst component added is 21 wt% as vanadium oxide in the catalyst component-containing titania fiber obtained by spinning and firing.

The polymer solution was filtered through a 3 μm membrane filter made of Teflon, and then heated to distill a mixed solvent of a solvent (isopropyl alcohol) and an organic solvent (tetrahydrofuran) and concentrated to obtain 200 g of a spinning solution. Was. At this time, the viscosity of the spinning solution was 50 poise at 40 ° C.

The spinning solution at 40 ° C. was sprayed with nitrogen gas at 20 kg / cm ² through a nozzle having a diameter of 50 μm through a nozzle having a relative humidity of 6 at 40 ° C.
It was extruded into a 0% air atmosphere and wound at a speed of 70 m / min to obtain a precursor fiber.

The obtained precursor fiber was heated at 85 ° C. and a relative humidity of 95%.
(Water vapor partial pressure: 0.54 atm), placed in a thermo-hygrostat for 15 hours, heated at a rate of 200 ° C./hr, fired in air at 500 ° C. for 1 hour, 15μ
m of the catalyst component-containing titania fiber were obtained. Table 1 shows the physical properties and denitration ratio of the obtained catalyst component-containing titania fiber.

Example 2 300.0 g of titanium tetraiso-isopropoxide (first-class reagent, manufactured by Wako Pure Chemical Industries) as titanium alkoxide
And 55.0 g of ethyl acetoacetate (reagent grade, manufactured by Wako Pure Chemical Industries) as a compound having active hydrogen was dissolved in 73.6 g of isopropyl alcohol (reagent grade, manufactured by Wako Pure Chemical Industries) as a solvent. After refluxing for 1 hour, a titanium alkoxide solution was prepared. At this time, the molar ratio of ethyl acetoacetate to titanium isopropoxide is 0.40. 36.0 g of water was mixed with 324.8 g of isopropyl alcohol, and a water concentration of 10
A weight percent of water was prepared. The amount of the water is 1.9 mol per 1 mol of titanium alkoxide.

At the same time, the titanium alkoxide solution was heated in a nitrogen atmosphere and refluxed under boiling, and at the same time, while distilling off the solvent, water was added with stirring. The distillation rate of the solvent and the supply rate of the solvent by adding water were adjusted to be substantially equal, and the addition time was adjusted to be 103 minutes.

[0046] From the time when the addition was started and 1.8 moles of water was added to 1 mole of the titanium alkoxide, the precipitation of the polymer started, and when the entire amount of water was added, a complete slurry state was obtained. Was.

After refluxing the slurry for 1 hour, the solvent was distilled off by heating as it was, and the Ti concentration was 3.46 ×
It was concentrated to 10 ⁻³ mol / g. The amount of water discharged out of the system by the operation up to this point was 0.14 mol per 1 mol of titanium alkoxide. Therefore, the difference between the amount of water added and the amount of water discharged out of the system together with the solvent or the like is 1.76 with respect to 1 mol of titanium alkoxide.
It was a molar amount.

352 g of tetrahydrofuran (special grade reagent, manufactured by Wako Pure Chemical Industries) was added as an organic solvent to the slurry,
After refluxing for 1 hour to dissolve the polymer, 37.2 g of ethyl silicate (trade name: ethyl silicate 40, manufactured by Tama Chemical Industry Co., Ltd.) was added as a silicon compound and refluxed for 1 hour to obtain a polymer solution. . The addition amount of the silicon compound is 12% by weight as the silica content in the titania fiber containing the catalyst component obtained by spinning and firing. To the polymer solution was added 51.2 g of triethoxyvanadyl (manufactured by Kojundo Chemical) as a catalyst component, and the mixture was refluxed for 1 hour. The catalyst component is added in an amount of 19% by weight as vanadium oxide in the titania fiber containing the catalyst component obtained by spinning and firing.

After the polymer solution was filtered through a 3 μm membrane filter made of Teflon, the mixture was heated to distill a mixed solvent of a solvent (isopropyl alcohol) and an organic solvent (tetrahydrofuran) and concentrated to obtain 200 g of a spinning solution. Was. At this time, the viscosity of the spinning solution was 50 poise at 40 ° C.

The spinning solution at 40 ° C. was sprayed with a nitrogen gas at 20 kg / cm ² through a nozzle having a diameter of 50 μm through a 40 ° C. relative humidity of 6 ° C.
It was extruded into a 0% air atmosphere and wound at a speed of 70 m / min to obtain a precursor fiber.

The obtained precursor fiber was heated at 85 ° C. and a relative humidity of 95%.
(Water vapor partial pressure: 0.54 atm), placed in a thermo-hygrostat for 15 hours, heated at a rate of 200 ° C./hr, fired in air at 500 ° C. for 1 hour, 15μ
m of the catalyst component-containing titania fiber were obtained. Table 1 shows the physical properties and denitration ratio of the obtained catalyst component-containing titania fiber.

Example 3 300.0 g of titanium tetraiso-propoxide (first-class reagent, manufactured by Wako Pure Chemical Industries) as a titanium alkoxide, 51.2 g of triethoxyvanadyl (manufactured by Kojundo Chemical) as a catalyst component, and active hydrogen 55.0 g of ethyl acetoacetate (special grade reagent, manufactured by Wako Pure Chemical Industries) as a compound having
With isopropyl alcohol (reagent grade,
55.4 g) and refluxed for 1 hour under a nitrogen atmosphere to prepare a titanium alkoxide solution. At this time, the amount of the catalyst component added is determined by the amount of vanadium oxide (V) in the obtained catalyst component-containing titania fiber.
₂ O ₅ ) in an amount of 19% by weight. The molar ratio of ethyl acetoacetate to titanium isopropoxide is 0.40. 37.9 g of water was mixed with 341.9 g of isopropyl alcohol to prepare a water having a water concentration of 10% by weight. The amount of this water is 2.0 moles per mole of titanium alkoxide.

The titanium alkoxide solution was heated in a nitrogen atmosphere and refluxed under boiling, and at the same time, while distilling off the solvent, water was added with stirring. The distillation rate of the solvent and the supply rate of the solvent by adding water were adjusted to be substantially equal, and the addition time was adjusted to be 108 minutes.

From the start of the addition, when about 1.8 moles of water was added to 1 mole of titanium alkoxide, the precipitation of the polymer started, and when the entire amount of water was added, a completely slurry state was obtained. Was.

After refluxing the slurry for 1 hour, the solvent was distilled off by heating as it was, and the Ti concentration was 3.46 ×
It was concentrated to 10 ⁻³ mol / g. The amount of water discharged out of the system by the operation up to this point was 0.07 mol per 1 mol of titanium alkoxide. Therefore, the difference between the amount of water added and the amount of water discharged out of the system together with the solvent and the like is 1.93 per mole of titanium alkoxide.
It was a molar amount.

To the slurry, 352 g of tetrahydrofuran (special grade reagent, manufactured by Wako Pure Chemical Industries, Ltd.) was added as an organic solvent.
After refluxing for one hour to dissolve the polymer, 37.2 g of ethyl silicate (trade name: ethyl silicate 40, manufactured by Tama Chemical Industry Co., Ltd.) was added as a silicon compound and refluxed for one hour to obtain a polymer solution. The addition amount of the silicon compound is 12% by weight as the silica (SiO ₂ ) content in the obtained catalyst component-containing titania fiber.

After the polymer solution was filtered through a 3 μm membrane filter made of Teflon, the mixture was heated to distill a mixed solvent of a solvent (isopropyl alcohol) and an organic solvent (tetrahydrofuran) and concentrated to obtain 200 g of a spinning solution. Was. At this time, the viscosity of the spinning solution was 50 poise at 40 ° C.

The spinning solution at 40 ° C. was sprayed with nitrogen gas at 20 kg / cm ² through a nozzle having a diameter of 50 μm through a nozzle having a relative humidity of 6 at 40 ° C.
It was extruded into a 0% air atmosphere and wound at a speed of 70 m / min to obtain a precursor fiber.

The obtained precursor fiber was heated at 85 ° C. and a relative humidity of 95%.
(Water vapor partial pressure: 0.54 atm), placed in a thermo-hygrostat for 15 hours, heated at a rate of 200 ° C./hr, fired in air at 500 ° C. for 1 hour, 15μ
m of the catalyst component-containing titania fiber were obtained. Table 1 shows the physical properties and denitration ratio of the obtained catalyst component-containing titania fiber.

Example 4 55.4 g of isopropyl alcohol as a solvent was added to 11
Example 3 was changed to 0.3 g, and 5 g of ethyl acetoacetate as a compound having active hydrogen was changed to 0 g.
Was performed in the same manner as described above. Table 1 shows the physical properties and denitration ratio of the obtained catalyst component-containing titania fiber.

Comparative Example 1 A catalyst component-containing titania fiber having a fiber diameter of 15 μm was obtained in the same manner as in Example 1 except that the steam treatment was not performed. Table 1 shows the physical properties and denitration ratio of the obtained catalyst component-containing titania fiber.

Example 5 300.0 g of titanium tetra-iso-propoxide (first-class reagent, manufactured by Wako Pure Chemical Industries) as a titanium alkoxide, 61.9 g of vanadium iso-propoxide (Nichia Chemical) as a catalyst component, and As a compound having active hydrogen, ethyl acetoacetate (special grade reagent, manufactured by Wako Pure Chemical Industries) 5
5.0 g was dissolved in 44.7 g of isopropyl alcohol (special grade reagent, manufactured by Wako Pure Chemical Industries) as a solvent, and refluxed under a nitrogen atmosphere for 1 hour to prepare a titanium alkoxide solution. At this time, the added amount of the catalyst component is an amount that becomes 20% by weight as vanadium oxide (V ₂ O ₅ ) in the obtained catalyst component-containing titania fiber. The molar ratio of ethyl acetoacetate to titanium isopropoxide is 0.40. 40.7 g of water was mixed with 367.6 g of isopropyl alcohol to prepare a water having a water concentration of 10% by weight. The amount of the water is 2.15 mol per 1 mol of the titanium alkoxide.

At the same time, the titanium alkoxide solution was heated in a nitrogen atmosphere and refluxed under boiling, and at the same time, while distilling off the solvent, water was added with stirring. The distillation rate of the solvent and the supply rate of the solvent by adding water were adjusted so as to be substantially equal, and the addition time was adjusted so as to be 116 minutes.

[0064] From the time when the addition was started and 1.8 moles of water was added to 1 mole of the titanium alkoxide, the precipitation of the polymer started, and when the entire amount of water was added, a complete slurry state was obtained. Was.

After refluxing the slurry for 1 hour, the solvent was distilled off by heating as it was, and the Ti concentration was 3.46 ×
It was concentrated to 10 ⁻³ mol / g.

To the slurry, 352 g of tetrahydrofuran (special grade reagent, manufactured by Wako Pure Chemical Industries, Ltd.) was added as an organic solvent.
After the polymer was dissolved by refluxing for 2 hours, 23.4 g of ethyl silicate (trade name: ethyl silicate 40, manufactured by Tama Chemical Industry Co., Ltd.) was added as a silicon compound, followed by reflux for 1 hour to obtain a polymer solution. The addition amount of the silicon compound is 8% by weight as the silica (SiO ₂ ) content in the obtained catalyst component-containing titania fiber.

After the polymer solution was filtered through a 3 μm membrane filter made of Teflon, the mixture was heated to distill a mixed solvent of a solvent (isopropyl alcohol) and an organic solvent (tetrahydrofuran) and concentrated to obtain 200 g of a spinning solution. Was. At this time, the viscosity of the spinning solution was 50 poise at 40 ° C.

The spinning solution at 40 ° C. was sprayed with a nitrogen gas at 20 kg / cm ² through a nozzle having a diameter of 50 μm through a nozzle having a relative humidity of 40 ° C.
It was extruded into a 0% air atmosphere and wound at a speed of 70 m / min to obtain a precursor fiber.

The obtained precursor fiber was heated at 85 ° C. and a relative humidity of 95%.
(Water vapor partial pressure: 0.54 atm), placed in a thermo-hygrostat for 15 hours, heated at a rate of 200 ° C./hr, fired in air at 500 ° C. for 1 hour, 15μ
m of the catalyst component-containing titania fiber were obtained.

The obtained catalyst component-containing titania fiber (BET specific surface area: 152 m ² / g, total volume of pore volume: 0.16
cc / g, pore volume of 0.1% or more 0.16 cc / g,
Silica content 8% by weight, tensile strength 0.3 GPa, V
6 g of ₂ O ₅ content (20% by weight) and 9 g of SiC (trade name: Shinano Random, manufactured by Shinano Electric Refining Co., Ltd.) were filled in a glass reaction tube (inner diameter: 15 mmφ, filling height: 110 mm). After heating the reaction tube to 300 ° C., monochlorobenzene (hereinafter referred to as MCB) heated to the same temperature as the reaction tube: 100 ppm, CO ₂ : 270 ppm, O ₂ :
A gas consisting of 15%, balance: N ₂ was passed through the reaction tube at a flow rate of 250 mL / min. The inlet gas and the outlet gas of the reaction tube are passed through methyl alcohol to absorb MCB, and the concentration of each MCB is measured by liquid chromatography (trade name: LC-6).
AD, SCL-6B, detection wavelength 270 nm, manufactured by Shimadzu Corporation), and the MCB decomposition rate was determined from the following equation. Table 2 shows the results. MCB decomposition rate (%) = (AB) / A × 100 A: MCB concentration in methyl alcohol absorbing the inlet gas B: MCB concentration in methyl alcohol absorbing the outlet gas

Example 6 Example 5 was repeated except that the temperature of the reaction tube was changed to 200 ° C. Table 2 shows the results.

[0072]

【table 1】

[0073]

[Table 2]

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) B01J 37/03 B01D 53/36 ZABG C01G 23/053 101Z 102D (72) Inventor Miaki Takeuchi Niihama-shi, Ehime 5-1, Sokaicho Sumitomo Chemical Co., Ltd. F-term (reference) 4D048 AA06 AA11 AA17 AB01 AB02 AB03 BA01Y BA02Y BA03Y BA07X BA08Y BA22Y BA23X BA25Y BA26Y BA27Y BA30Y BA32Y BA36Y BA38Y BA41X BB08 4G0A09 A08 A07A08 AA12 BA04A BA04B BA04C BB04A BB04B BB04C BC09A BC10A BC16A BC27A BC51A BC54A BC54B BC54C BC58A BC59A BC60A BC66A BC68A BC70A BC75A CA07 CA08 CA10 CA13 CA15 CA19 DA06 EA03X EA0312 FB05 PS3 FA03 PS17 FA12

Claims (5)

[Claims] 1. A method in which water is added to a solution in which a titanium alkoxide is dissolved in a solvent to carry out a hydrolysis reaction and a polymerization reaction to form a polymer in the solution, and the polymer is dissolved in an organic solvent in which the polymer is soluble. Dissolving in a solvent to obtain a spinning solution, spinning the spinning solution to obtain a precursor fiber, and firing the precursor fiber, wherein the catalyst component is added to the step and / or
Or obtaining a spinning solution by spinning the spinning solution, and subjecting the precursor fiber obtained by spinning the spinning solution to steam treatment before and / or during firing. 2. The catalyst component according to claim 1, wherein a silicon compound is added so that the silica content in the catalyst component-containing titania fiber obtained after the calcination is 40% by weight or less. A method for producing titania fibers. 3. V, W, Al, As, N as a catalyst component
i, at least one of metal compounds selected from the group consisting of Zr, Mo, Ru, Mg, Ca, Fe, Cr and Pt
The method for producing titania fiber containing a catalyst component according to claim 1 or 2, wherein a seed is added. 4. The steam treatment condition of the precursor fiber is 0.3
The method for producing titania fiber containing a catalyst component according to any one of claims 1 to 3, wherein the holding is performed for 30 minutes or more in an atmosphere having a partial pressure of water vapor or more. 5. The method for producing titania fiber containing a catalyst component according to claim 1, wherein a compound having active hydrogen is added.