JP5530077B2 - Photocatalytic member and air purification device - Google Patents

Description

  The present invention relates to a photocatalytic member and an air purification device.

  The decomposition of organic substances by photocatalyst was found about 30 years ago. When a certain type of semiconductor such as titanium oxide is irradiated with light, electrons and holes are generated, and the generated electrons and holes generate superoxide anion radicals and hydroxy radicals on the semiconductor surface. Superoxide anion radicals and hydroxy radicals attack organic molecules to decompose organic substances. A semiconductor material having such an action is called a photocatalytic material. The material used as the photocatalyst is most often titanium dioxide, and it is no exaggeration to say that the photocatalyst means titanium oxide.

To date, many products and devices utilizing organic decomposition by photocatalysts have been proposed. In particular, devices and filters that decompose odor (organic gas) components in the air by photocatalysis are being actively developed. For example, improving the deodorization rate by combining a photocatalyst with an adsorbent (for example, Patent Document 1), or improving the decomposition rate for a specific gas such as ethylene by combining a photocatalyst and high silica zeolite (for example, Patent Document 2) and the like have been proposed. In addition, it has been proposed to improve the processing efficiency of the photocatalyst module by using a base material formed of light-transmitting long fibers as the base material supporting the photocatalyst film (for example, Patent Documents). 3).
JP-A-1-189322 JP 7-16473 A JP 2002-239394 A

  However, the deodorization speed of the conventional purification device is insufficient, and a photocatalytic member having higher deodorization performance is required. Therefore, the present invention provides a photocatalytic member having improved deodorization performance.

The photocatalytic member of the present invention is a photocatalytic member in which a photocatalytic material is supported on a filter base material, the filter base material is a fiber fabric, and the photocatalytic material includes a titanium oxide photocatalyst, an adsorbent, and the like. The total loading of the titanium oxide photocatalyst and the adsorbent per unit area in the filter substrate is 10 to 50 mg / cm ² .

  As another aspect, the photocatalytic member of the present invention is a photocatalytic member in which a photocatalytic material is supported on a filter base material, and the photocatalytic material contains anatase-type titanium oxide and fluorine-containing titanium oxide photocatalyst. And zeolite, the filter substrate is a glass fiber fabric, and the ratio of F to the total mass of Ti, Si and F contained in the photocatalytic member is 0.38% by mass or more.

  According to the present invention, a photocatalytic member having improved deodorizing performance can be provided.

  In the present invention, “deodorization” refers to adsorption and / or decomposition of odor components and organic substances in the gas phase. Preferably, the concentration of odorous components and organic substances in the gas phase is reduced. More preferably, the odorous components and organic substances in the gas phase are adsorbed by the adsorption action of the adsorbent, and the titanium oxide photocatalyst is irradiated with ultraviolet light. Is used to decompose odor components and the like to reduce the concentration of odor components and organic substances. Examples of the odor component include acetaldehyde, acetic acid, ammonia, sulfur compound gas (hydrogen sulfide, methyl mercaptan, etc.), etc. Among them, the photocatalytic member of the present invention is suitable for deodorization of acetaldehyde.

[First photocatalytic member]
The first photocatalytic member is a photocatalytic member in which a photocatalytic material is supported on a filter base material, the filter base material is a fiber fabric, and the photocatalytic material includes a titanium oxide photocatalyst, an adsorbent, and the like. The total loading of the titanium oxide photocatalyst and the adsorbent per unit area in the filter base material (hereinafter referred to as “catalyst loading”) is 10 to 50 mg / cm ² .

Conventionally, when a large amount of a photocatalyst or an adsorbent is supported on a filter base material, it has been thought that sufficient deodorization performance cannot be obtained because pressure loss is greatly increased. On the other hand, the first photocatalytic member of the present invention allows the photocatalytic material to be added to the filter base material without increasing pressure loss if the amount of catalyst supported per unit area in the filter base material is 10 to 50 mg / cm ^2. It is based on the knowledge that it can be made to carry | support to a deodorizing performance further. According to the first photocatalytic member, the catalyst loading is 10 to 50 mg / cm ² , so that the deodorization rate can be improved and the life of the filter can be greatly extended. Furthermore, according to the first photocatalytic member, since the filter base material is a fiber fabric, for example, the filter base material is compared with the case of a porous filter such as porous ceramic or foamed polyurethane. The internal titanium oxide photocatalyst can be sufficiently irradiated with light, and the deodorization speed during light irradiation can be improved. According to the first photocatalytic member, since the photocatalytic material includes a titanium oxide photocatalyst and an adsorbent, for example, the deodorizing performance can be exhibited both during light irradiation and during light extinction, and the energy saving effect is excellent.

In the first photocatalytic member, the catalyst loading is 10 to 50 mg / cm ² . If the amount of the catalyst supported is 10 mg / cm ² or more, the deodorization rate can be sufficiently improved, and if it is 50 mg / cm ² or less, the photocatalytic material can be supported on the filter substrate without peeling. The amount of catalyst supported is preferably 10 to 40 mg / cm ² from the viewpoint of deodorization performance and cost. The catalyst loading (mg / cm ² ) is measured, for example, by measuring the weight of the titanium oxide photocatalyst and the adsorbent supported on a 200 cm ² photocatalytic member, and calculating the total weight of the titanium oxide photocatalyst and the adsorbent in the area (200 cm ² ) Can be calculated.

The thickness of the photocatalytic material in the first photocatalytic member can be appropriately determined according to the aperture ratio of the filter base material, but is, for example, 180 μm or more, preferably 180 to 1000 μm, more preferably 200 to 800 μm, More preferably, it is 200-620 micrometers. In the present invention, the thickness of the photocatalytic material refers to the thickness of the photocatalytic material carried on the fibers constituting the filter base material. For example, the thickness of the photocatalytic member and the thickness of the filter base material are used as follows. It can be calculated from the formula.
Photocatalytic material thickness = {(photocatalytic material thickness) − (filter substrate thickness)} / 2

  In the first photocatalytic member, the photocatalytic material includes a titanium oxide photocatalyst and an adsorbent.

[Titanium oxide photocatalyst]
Examples of the titanium oxide include anatase-type titanium oxide, rutile-type titanium oxide, and brookite-type titanium oxide. Anatase-type titanium oxide is preferable because it has high photocatalytic activity. In the present invention, “anatase-type titanium oxide” refers to titanium oxide in which a diffraction peak appears in the vicinity of a diffraction angle 2θ = 25.5 degrees in powder X-ray diffraction spectrum measurement (use electrode: copper electrode).

  The titanium oxide photocatalyst includes anatase-type titanium oxide and fluorine from the viewpoint of improving the deodorization rate, the fluorine content in the titanium oxide photocatalyst is 2.5 to 3.5% by weight, and 90% by weight of fluorine. A titanium oxide photocatalyst in which at least% is chemically bonded to titanium oxide is preferred. If the fluorine content is 2.5% by weight or more, for example, fluorine having a high electronegativity is located on the titanium oxide surface. Due to the electron withdrawing action of fluorine, adjacent hydroxyl groups are activated and hydroxyl radicals are easily generated. As a result, it is considered that the photocatalytic reaction is promoted and the deodorization rate can be improved. Moreover, if the fluorine content is 3.5% by weight or less, for example, it is considered that the number of hydroxyl groups necessary for the photocatalytic reaction on the titanium oxide surface can be secured and the deodorization rate can be maintained.

  The fluorine content in the titanium oxide photocatalyst is preferably 2.7 wt% to 3.3 wt%, more preferably 2.9 wt% to 3.1 wt% in terms of elemental amount. The fluorine content can be determined, for example, using an absorptiometric analysis method (JIS K 0102).

  From the viewpoint of improving photocatalytic activity and deodorization rate, the fluorine chemically bonded to titanium oxide is preferably 90% by weight or more of all fluorine in the titanium oxide photocatalyst, more preferably 95% by weight or more, and Preferably, 100% by weight, that is, the total amount of fluorine contained in the titanium oxide photocatalyst is chemically bonded to titanium oxide. In the titanium oxide photocatalyst, the content of fluorine chemically bonded to titanium oxide is, for example, 2.35 wt% to 3.5 wt%, preferably 2.5 wt% to 3.5 wt%. Preferably it is 2.5 weight%-3.3 weight%.

In the present invention, “chemical bond between titanium oxide and fluorine” means that titanium oxide and fluorine are chemically bonded. Preferably, it refers to a state in which titanium oxide and fluorine are bonded at the atomic level, not supported or mixed, and more preferably it means that titanium oxide and fluorine are ionically bonded. In the present invention, “chemically bonded fluorine” means, for example, fluorine that does not elute into water among fluorine contained in the titanium oxide photocatalyst. The amount of fluorine chemically bonded to titanium oxide is determined by dispersing the titanium oxide photocatalyst in water and maintaining pH = 3 or lower or pH = 10 or higher with a pH adjusting agent (for example, hydrochloric acid or aqueous ammonia). It can be calculated by measuring the elution amount of fluorine ions by colorimetric titration or the like and subtracting the elution amount from the total amount of fluorine contained in the titanium oxide photocatalyst. The elution amount of fluorine ions can be measured as in Examples described later. In the present invention, “titanium oxide and fluorine are ionically bonded” means that when the titanium oxide photocatalyst is analyzed with a photoelectron spectrometer, the peak top of the fluorine 1s orbital (F _1s ) is in the range of 683 eV to 686 eV. This is the case. This is because the value of the peak top of titanium fluoride in which fluorine and titanium are ion-bonded is within the above range.

  The titanium oxide photocatalyst may contain sodium, but it is preferable not to contain sodium from the viewpoint of improving the photocatalytic activity and the deodorization rate. When sodium is included, the ratio (A / B) of the sodium content (A wt%) in the total titanium oxide photocatalyst to the fluorine content (B wt%) in the total titanium oxide photocatalyst is determined by the photocatalytic activity and From the viewpoint of improving the deodorization rate, it is preferably 0.01 or less, more preferably 0.005 or less, and still more preferably 0.001 or less.

The specific surface area of the titanium oxide photocatalyst, increase in contact surface between the photocatalyst and odorous components, also from the viewpoint of improvement of the photocatalytic reaction efficiency, 200~350m ² / g is preferably, more preferably 250 to 350 ² / g . Here, in the present invention, the specific surface area means a surface area value per 1 g of the titanium oxide photocatalyst powder measured by the BET method (nitrogen adsorption / desorption method). When the specific surface area is 200 m ² / g or more, the contact area with the object to be decomposed can be increased.

[Adsorbent]
Examples of the adsorbent include aluminosilicate and silica gel. Of these, aluminosilicate is preferable, and examples of the aluminosilicate include zeolite. Among the zeolites, high silica zeolite is preferable from the viewpoint of ultraviolet light permeability and deodorizing performance, and ZSM-5 type zeolite is more preferable from the viewpoint of adsorption of odor components. The molar component ratio of silica and alumina in the zeolite (silica / alumina) is, for example, 10 or more, preferably 1500 or more.

As the zeolite, a commercially available product may be used. Examples of commercially available products include HSZ-890HOA (manufactured by Tosoh Corporation, ZSM-5 type, silica / alumina ratio: 1500 to 2000 (average: 1890), average particle size of 8 to 14 μm, cation type: H, specific surface area ( BET): 280-330 m ² / g), HiSiv (TM) -3000 (manufactured by Union Showa Co., Ltd., average particle size: 12.7 μm, cation type: Na, pore size: 6 mm or less, specific surface area (BET): 400 m ² / g or more).

  The content of the titanium oxide photocatalyst in the photocatalytic material is preferably 20 to 90% by weight, more preferably 60 to 80% by weight from the viewpoint of deodorizing performance during light irradiation. In addition, the content of the adsorbent in the photocatalytic material is preferably 10 to 80% by weight, more preferably 20 to 30% by weight, from the viewpoint of deodorizing performance.

  The weight ratio of the titanium oxide photocatalyst to the adsorbent in the photocatalytic material (weight of the titanium oxide photocatalyst: weight of the adsorbent) is, for example, 9: 1 to 1: 9, and 8: 2 to 5 in terms of deodorizing performance. : 5 is preferable, and 7: 3 is more preferable.

  The photocatalytic material may contain a binder as another component from the viewpoint of improving the adhesion between the titanium oxide and / or the adsorbent and the filter substrate. Examples of the binder include colloidal silica, colloidal alumina, montmorillonite, and kaolin. The content of the binder in the photocatalytic material is preferably 20 to 30% by weight from the viewpoint of deodorizing performance during light irradiation. The ratio of the binder in the photocatalytic material can be appropriately determined according to the kind of binder and the binding force, but it is preferably small from the viewpoint of improving the deodorizing performance. When the binder is colloidal silica, the weight ratio of the total of titanium oxide photocatalyst and adsorbent to the binder in the photocatalytic material (total weight of titanium oxide photocatalyst and adsorbent: weight of binder) is, for example, 10: 0 to 5 : 5, preferably 9: 1 to 7: 3.

[Filter base material]
In the first photocatalytic member, the filter substrate is a fiber fabric. Examples of the fiber fabric include a knitted fabric, a woven fabric, and a non-woven fabric. Among these, a knitted fabric and a woven fabric are preferable from the viewpoint of pressure loss, and a woven fabric is more preferable. Examples of fibers used in the fabric include polyamide fibers, polyester fibers, polyalkylene paraoxybenzoate fibers, polyurethane fibers, polyvinyl alcohol fibers, polyvinylidene chloride fibers, polyvinyl chloride fibers, and polyacrylonitrile fibers. Synthetic fibers such as fibers, polyolefin fibers and phenol fibers; inorganic fibers such as glass fibers, metal fibers, alumina fibers and activated carbon fibers; natural fibers such as wood pulp, hemp pulp and cotton linter pulp; and recycled fibers Among them, glass fiber is preferable from the viewpoint of light transmittance. A glass fiber woven fabric is preferably used as the filter substrate.

The porosity of the filter substrate is preferably 10% or more from the viewpoint of pressure loss, preferably 50% or less, more preferably 25% or less, from the viewpoint of maintaining the strength and deodorization rate of the substrate. Therefore, the porosity of the filter substrate is preferably 10 to 50%, more preferably 10 to 25%. The aperture ratio of the filter substrate can be calculated from the following formula using, for example, the area of the filter substrate and the area of the opening.
Opening ratio (%) = {(area of opening) / (area of filter substrate)} × 100

[Second photocatalytic member]
As described above, the second photocatalytic member is a photocatalytic member in which a photocatalytic material is supported on a filter base material, and the photocatalytic material includes an anatase-type titanium oxide and a fluorine-containing titanium oxide photocatalyst, zeolite, The filter base material is a glass fiber fabric, and the ratio of F to the total mass of Ti (titanium), Si (silicon) and F (fluorine) contained in the photocatalytic member (F mass / (Ti, The sum of the masses of Si and F) × 100) is 0.38% by mass or more.

  Since the ratio of F is 0.38 mass% or more, the 2nd photocatalytic member can improve a deodorizing speed, for example. Further, according to the second photocatalytic member, since the photocatalytic material includes a titanium oxide photocatalyst and an adsorbent, for example, deodorizing performance can be exhibited both during light irradiation and during extinguishing. For this reason, according to the 2nd photocatalytic member, it is excellent in the energy-saving effect, for example. The masses of Ti, Si, and F can be determined using, for example, an ion chromatograph.

  The photocatalytic material in the second photocatalytic member contains anatase-type titanium oxide and a titanium oxide photocatalyst containing fluorine and zeolite. The titanium oxide photocatalyst containing anatase-type titanium oxide and fluorine contains anatase-type titanium oxide and fluorine exemplified in the first photocatalytic material from the viewpoint of improving the deodorization rate, and the content of fluorine in the titanium oxide photocatalyst is The titanium oxide photocatalyst is preferably 2.5 to 3.5% by weight, and 90% by weight or more of fluorine is chemically bonded to titanium oxide.

  As the adsorbent, the same adsorbent as exemplified in the first photocatalytic member can be used. The photocatalytic material of the second photocatalytic member may contain a binder as another component from the viewpoint of improving the adhesion between titanium oxide and / or the adsorbent and the filter base material. Examples of the binder include colloidal silica, colloidal alumina, montmorillonite, and kaolin. The content of the binder in the photocatalytic material is preferably 20 to 30% by weight from the viewpoint of deodorizing performance during light irradiation.

  The second photocatalytic member may be used in the form of a sheet (flat plate), or may be used after being formed into a honeycomb by, for example, pleating or corrugating.

[Method for producing photocatalytic member]
The first and second photocatalytic members can be produced, for example, by applying a photocatalytic material containing the above-described titanium oxide photocatalyst and zeolite to a filter substrate. After the photocatalytic material is dispersed in a solvent or the like, the photocatalytic material may be applied to a filter substrate. As the solvent, for example, water and ethyl alcohol can be used. Further, the photocatalytic material and the binder may be mixed, and the mixture may be applied to the filter base material, or the binder may be applied to the filter base material in advance, and then the photocatalytic material may be applied. Examples of the coating method include slurry coating, spin coating, spray coating, casting coating, and the like.

  The fluorine-containing titanium oxide photocatalyst, for example, is a mixture of an anatase-type titanium oxide aqueous dispersion in which the adsorption amount of n-butylamine is 8 μmol / g or less and a fluorine compound, and the pH of the mixture exceeds 3 Can be produced by reacting titanium oxide with a fluorine compound in a mixed solution by adjusting the pH to 3 or less using an acid. As the anatase type titanium oxide whose n-butylamine adsorption amount is 8 μmol / g or less, for example, SSP-25 manufactured by Sakai Chemical Industry Co., Ltd. can be used. As the aqueous dispersion, for example, CSB-M manufactured by Sakai Chemical Industry Co., Ltd. can be used. Examples of the fluorine compound include ammonium fluoride, potassium fluoride, sodium fluoride, hydrofluoric acid, and the like.

[Air quality purification equipment]
As another aspect, the present invention includes an air purification device including the photocatalytic member of the present invention. The air purification apparatus preferably further includes an ultraviolet light source, and more preferably includes a light source that emits light having a wavelength of 400 nm or less. According to the air purification apparatus of the present invention, for example, the decomposition performance and decomposition rate of odor components can be improved. The air purification apparatus of the present invention may further include an air supply means for introducing a gas containing an organic substance into the photocatalytic member from the viewpoint of improving the deodorization speed of the odor component. As the air supply means, for example, a blower such as a sirocco fan can be used.

  Examples of the present invention will be described below together with comparative examples. In addition, this invention is not limited to the following Example.

(Relationship between filter substrate hole area ratio and pressure loss)
Pressure loss (unit: Pa) at a surface wind speed of 1 m / s was measured with a pressure gauge (manometer) for four types of filter base materials (glass fiber woven fabrics, product names: V375H, V385H, manufactured by Unitika Ltd.) with different open areas. ). The obtained pressure loss is shown in Table 1 below together with the hole area ratio. As shown in Table 1 below, it was found that when the hole area ratio was less than 5%, the pressure loss at the maximum air volume exceeded 35 Pa.

[Aperture rate of filter substrate]
The aperture ratio of the filter base material was obtained by measuring the area of the filter base material and the area of the opening using a ruler and calculating from the following formula using them.
Opening ratio (%) = {(area of opening) / (area of filter substrate)} × 100

(Examples 1-17)
1. Preparation of titanium oxide photocatalyst The concentration of titanium oxide (trade name: SSP-25, manufactured by Sakai Chemical Industry Co., Ltd., anatase type, particle size: 5-10 nm, specific surface area: 270 m ² / g or more) is 150 g / L. Pure water was added to titanium oxide, and this was stirred to prepare a titanium oxide dispersion. To this titanium oxide dispersion, hydrofluoric acid (made by Wako Pure Chemical Industries, special grade) corresponding to 5.0% by weight in terms of fluorine (element) is added to titanium oxide while maintaining the pH at 3. The reaction was performed at 25 ° C. for 60 minutes. The resulting reaction product was washed with water. The washing with water was performed until the electric conductivity of the filtrate collected by filtering the reaction product was 1 mS / cm or less. And this was dried in air at 130 degreeC for 5 hours, and the titanium oxide photocatalyst was prepared.

[Fluorine content]
When the fluorine content in the titanium oxide photocatalyst was determined by absorptiometric analysis (JIS K 0102), it was 3.3% by weight.

[Confirmation of bond between fluorine and titanium oxide]
When the titanium oxide photocatalyst was analyzed with a photoelectron spectrometer, it showed a spectrum in which the peak top of F _1s was in the range of 683 eV to 686 eV. That is, it was confirmed that titanium oxide and fluorine were ionically bonded in the obtained titanium oxide photocatalyst.

[Confirmation of anatase type]
When the titanium oxide photocatalyst was analyzed by a powder X-ray diffractometer (electrode used: copper electrode), a diffraction peak appeared at a diffraction angle 2θ = 25.5 degrees. That is, the obtained titanium oxide photocatalyst was anatase type titanium oxide.

2. Production of Photocatalytic Member 490 g of the obtained titanium oxide photocatalyst and 210 g of zeolite (trade name: HSZ-890HOA, manufactured by Tosoh Corporation, silica / alumina ratio (molar ratio): 1950) were dry-mixed for 1 minute using a mortar. 700 g of a mixture of titanium oxide photocatalyst and zeolite is dispersed in colloidal silica, Snowtex O, manufactured by Nissan Chemical Co., Ltd., and pasted into three types of filter base materials (glass cloth, trade names: V375H, V385H, The photocatalytic members of Examples 1 to 17 and Comparative Examples 1 to 6 shown in Tables 2 to 4 below were prepared by attaching to Unitika, 200 cm ² (100 mm × 200 mm)). In addition, the filter base material with a porosity of 50% was produced by removing some fibers from a glass fiber nonwoven fabric (manufactured by Unitika Ltd.) having a trade name of V375H so that the porosity was 50%.

[Catalyst loading]
The amount of catalyst supported was calculated by dividing the total weight of the titanium oxide photocatalyst and zeolite adhering to the filter substrate by the area of the filter substrate (200 cm ² ).

[Thickness of photocatalytic material]
The photocatalytic member was sandwiched between two glass plates, and the thickness was measured with a micrometer. Using the measured value, the thickness of the glass plate, and the thickness of the filter substrate, the thickness of the photocatalytic material was calculated from the following formula.
Photocatalytic material thickness = [Measured value− (Glass plate thickness) × 2- (Filter substrate thickness)] / 2

[Ratio of F to the total mass of Ti, Si and F contained in the photocatalytic member]
The masses of Ti, Si and F in the photocatalytic member were measured using an ion chromatograph. Using the obtained mass, the ratio of F to the total mass of Ti, Si and F was calculated from the following formula.
F ratio = {F mass / (Ti mass + Si mass + F mass)} × 100

3. Measuring device As the measuring device, a measuring device having the configuration shown in FIG. 1 was used. The measuring apparatus 101 in FIG. 1 includes an acrylic box (internal volume: 100 L) 105, a deodorizing unit 103 and a stirring fan 102 disposed therein. The acrylic box 105 includes an introduction port 108 for introducing an odor component and an exhaust port 109 capable of sampling the air in the acrylic box 105. A gas chromatograph (trade name: GC-14B, manufactured by Shimadzu Corporation) equipped with an automatic sampling device every 3 minutes is connected to the discharge port 109 (not shown). Science) was used.

In the deodorizing unit 103, a black light 104, a photocatalytic member (100 mm × 200 mm) 103, and a blower 107 are arranged in this order, and gas can be introduced in a direction orthogonal to the surface of the photocatalytic member 106 by the blower 107. . As the black light 104, a black light blue fluorescent lamp (product number: FL6BL-B, manufactured by Matsushita Electric, maximum wavelength: 352 nm, rated lamp power: 6 W, ultraviolet radiation output: 0.6 W) was used. The black light 104 was arranged so that the illuminance of ultraviolet rays (365 nm) applied to the photocatalytic member 106 was 1.0 mW / cm ² . The illuminance was measured using an ultraviolet integrated light meter (trade name: UVD-S365, manufactured by USHIO INC.).

4). Evaluation Method While rotating the stirring fan 102, the air in the measuring apparatus 101 of FIG. 1 in which the photocatalytic member 106 was arranged was replaced with dry air. Subsequently, 1.80 L of standard gas diluted with nitrogen (acetaldehyde: 524 ppm) was introduced, and the acetaldehyde concentration in the acrylic box 105 was set to 10 ppm. Immediately after the introduction of acetaldehyde, the black light was turned on and the blower 107 was rotated to start deodorization by the photocatalytic member 106. The acetaldehyde concentration was measured using a gas chromatograph every 3 minutes after the start of deodorization.

The time change of the acetaldehyde concentration from 3 minutes to 15 minutes after the start of deodorization was approximated logarithmically, and the absolute value of the slope was taken as the deodorization rate coefficient. The obtained deodorization rate coefficients (absolute values and relative values) are shown in Tables 2 to 4 below. Table 2 shows a photocatalytic member having a filter substrate with a 10% porosity, Table 3 shows a photocatalytic member with a 25% filter substrate, and Table 4 shows a filter substrate with a 50% porosity. The result of a photocatalytic member is shown, respectively. Moreover, it determined based on the following reference | standard according to the aperture ratio of a filter from the obtained deodorizing rate coefficient, and the determination result is combined with Tables 2-4. In Comparative Example 3, peeling of the photocatalytic material from the filter base material could not be measured significantly.
○: Deodorization rate coefficient has reached a steady state (a state in which the deodorization rate coefficient has become almost constant after reaching the maximum value). X: The steady state is not reached or measurement is not possible. In addition, the photocatalytic members of Examples 1, 4 and 5 About, the pressure loss was measured by the above-mentioned measuring method. The results are shown in Table 2.

As shown in Table 2 above, the photocatalytic members of Examples 1 to 8 having a catalyst loading amount of 10 to 50 mg / cm ² are all the photocatalysts of Comparative Examples 1 to 3 having a catalyst loading amount of less than 10 mg / cm ^2. The deodorization rate coefficient was higher than that of the sex member. In addition, the photocatalytic members of Examples 1, 4, and 5 having catalyst loadings of 10.7, 22.8, and 25.9 mg / cm ² , respectively, had a pressure loss of 25 Pa or less, and supported the photocatalytic material. It was almost the same as the previous pressure loss (20 Pa). That is, there is no significant increase in pressure loss due to the loading of the photocatalytic material, and the pressure loss of the photocatalytic member after loading is a pressure loss with excellent filter efficiency.

As shown in Tables 3 and 4 above, the photocatalytic members (opening ratio: 25%) of Examples 9 to 14 having a catalyst loading amount of 10 to 50 mg / cm ² both have a catalyst loading amount of 10 mg. The deodorization rate coefficient is higher than that of the photocatalytic members of Comparative Examples 4 and 5 less than / cm ^2, and the photocatalytic members of Examples 15 to 17 (opening rate: 50%) are more deodorized than the photocatalytic member of Comparative Example 6. The speed coefficient was high.

(Example 18)
Example 18 is the same as Example 1 except that a photocatalytic material is attached to a filter substrate coated with a colloidal silica solution (30% by weight, solvent: water), and the amount of catalyst supported is about 20 mg / cm ² . A photocatalytic member was prepared. The ratio of F to the total mass of Ti, Si and F in the obtained photocatalytic member was 0.62% by mass.

(Example 19)
As in Example 18, except that SSP-25 (trade name, manufactured by Sakai Chemical Industry Co., Ltd., anatase type, particle size: 5 to 10 nm, specific surface area: 270 m ² / g or more) was used as the titanium oxide photocatalyst. The photocatalytic member of Example 19 was produced.

  Acetaldehyde deodorization was evaluated in the same manner as in Example 1 using the photocatalytic members of Examples 18 and 19, and the deodorization rate coefficient (absolute value) was determined. As a result, the deodorization rate coefficient of the photocatalytic member of Example 18 was 0.248, and the deodorization rate coefficient of the photocatalytic member of Example 19 was 0.098. The titanium oxide photocatalyst contains anatase-type titanium oxide and fluorine, the fluorine content in the titanium oxide photocatalyst is 2.5 to 3.5% by weight, and 90% by weight or more of the fluorine is chemically bonded to titanium oxide. It was confirmed that the deodorization rate can be improved by using the titanium oxide.

(Example 20)
A photocatalytic member of Example 20 (perforation rate of filter base: 25%) was prepared in the same manner as in Example 9 except that the amount of the catalyst supported was about 20 mg / cm ² . The obtained photocatalytic member was inserted into the housing 203 shown in FIG. In the housing 203 of FIG. 2, a black light cooling cathode tube 202 is disposed between the photocatalytic member 201 and the photocatalytic member 201, and the illuminance of ultraviolet rays (365 nm) irradiated to the photocatalytic member 201 averages 1 It adjusted so that it might become 0.0 mW / cm < ² >. This casing 203 was incorporated in a deodorizing filter section of an air purifier (trade name: Air Rich, manufactured by Matsushita Electric Industrial Co., Ltd.) and placed in an environmental test chamber (internal volume: 23.2 m ³ ) made of stainless steel. Then, the water dilution of acetaldehyde was vapor diffused to adjust the indoor acetaldehyde concentration to 10 ppm. Thereafter, the odor in the environmental test sample was collected 30 minutes, 60 minutes and 90 minutes after the start of deodorization. The collected odor (3 L) was concentrated with DNPH (dinitrophenyl), and the acetaldehyde concentration was measured using liquid chromatography. The obtained results are shown in FIG.

  From FIG. 3, according to the photocatalytic member of Example 20, 90% or more of acetaldehyde could be deodorized 60 minutes after the start of deodorization.

  The present invention is useful for purification devices used for the purpose of deodorization, deodorization, air purification, and the like.

FIG. 1 is a perspective view of an air purification device used for evaluation of deodorization characteristics. FIG. 2 is a perspective view of a housing used for evaluation of deodorization characteristics. FIG. 3 is a graph showing the deodorization characteristics of acetaldehyde in Example 20.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 ... Measuring apparatus 102 ... Stirring fan 103 ... Deodorizing unit 104 ... Black light 105 ... Acrylic box 106 ... Photocatalytic member 107 ... Blower 108 ... Inlet 109 ... discharge port 201 ... photocatalytic member 202 ... black light cooling cathode tube 203 ... housing

Claims (11)

A photocatalytic member having a photocatalytic material supported on a filter substrate,
The filter substrate is a fiber fabric,
The photocatalytic material includes a titanium oxide photocatalyst and an adsorbent,
The titanium oxide photocatalyst contains anatase type titanium oxide and fluorine,
The fluorine content in the titanium oxide photocatalyst is 2.5 to 3.5% by weight,
90% by weight or more of the fluorine is a titanium oxide photocatalyst chemically bonded to the titanium oxide,
The photocatalytic member whose total loading of the said titanium oxide photocatalyst per said unit area in the said filter base material and the said adsorption agent is 10-50 mg / cm < ² >. The ratio of F to the total mass of Ti (titanium), Si (silicon) and F (fluorine) contained in the photocatalytic member (F mass / (total of mass of Ti, Si and F) × 100) is 0. The photocatalytic member according to claim 1, wherein the content is 38% by mass or more. The photocatalytic member according to claim 1, wherein the fiber fabric is a glass fiber woven fabric. The photocatalytic member according to any one of claims 1 to 3, wherein the filter substrate has a porosity of 10 to 50%. The supported amount is 10 to 40 mg / cm ^2, the photocatalytic member according to any one of claims 1 to 4. The photocatalytic member according to any one of claims 1 to 5, wherein the adsorbent is high silica zeolite. The photocatalytic member according to claim 1, wherein the photocatalytic material has a thickness of 180 μm or more. The photocatalytic member according to any one of claims 1 to 7, wherein the photocatalytic material includes at least one binder selected from the group consisting of colloidal silica, colloidal alumina, montmorillonite, and kaolin. A photocatalytic member having a photocatalytic material supported on a filter substrate,
The photocatalytic material comprises a titanium oxide photocatalyst and zeolite,
The titanium oxide photocatalyst contains anatase type titanium oxide and fluorine,
The fluorine content in the titanium oxide photocatalyst is 2.5 to 3.5% by weight,
90% by weight or more of the fluorine is a titanium oxide photocatalyst chemically bonded to the titanium oxide,
The filter base material is a glass fiber fabric;
The photocatalytic member whose ratio of F with respect to the sum total of the mass of Ti, Si, and F contained in a photocatalytic member is 0.38 mass% or more. An air quality purification apparatus comprising the photocatalytic member according to any one of claims 1 to 9. The air purification apparatus according to claim 10, further comprising an ultraviolet light source.

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