WO2013047710A1

WO2013047710A1 - Photocatalyst structure, method for producing photocatalyst structure, and air purification device

Info

Publication number: WO2013047710A1
Application number: PCT/JP2012/074993
Authority: WO
Inventors: 敏男高柳; 浩美高柳; 豪平田
Original assignee: 株式会社タカヤナギ
Priority date: 2011-09-28
Filing date: 2012-09-27
Publication date: 2013-04-04
Also published as: JPWO2013047710A1

Abstract

This photocatalyst structure comprises a sponge-like photocatalyst layer that is provided with a plurality of pores, and the photocatalyst layer contains a photocatalyst, a water absorbent polymer and a water-soluble binder. This air purification device comprises the photocatalyst structure, a first substrate on which the photocatalyst structure is arranged, a light source, and a second substrate on which the light source is arranged. The photocatalyst structure is arranged so as to face the light source. By comprising a photocatalyst layer wherein a photocatalyst is uniformly dispersed and a plurality of pores are formed, a photocatalyst structure having good photodecomposability can be provided. In addition, by comprising this photocatalyst structure, an air purification device which has good air purification function can be provided.

Description

Photocatalyst structure, method for producing photocatalyst structure, and air cleaning device

The present invention relates to a photocatalyst structure exhibiting a photocatalytic action, an air cleaning device using the photocatalyst structure, and a method for producing the photocatalyst structure, and in particular, purifies air by removing odorous substances and bacteria in the air. The present invention relates to a photocatalyst structure, a photocatalyst structure manufacturing method, and an air cleaning device.

Examples of air odor substances include ammonia generated from food or generated as second-hand tobacco smoke, and VOC (volatile organic substances such as acetaldehyde) generated from building materials. In general, the air purifier cleans air odorous substances in a so-called semi-closed space such as a living space or a car. The air purifier treats not only such a general air environment but also a poor environment in which a strong odor substance is continuously generated in a temporary toilet having a sealed space of about 1.5 m ³ , for example. There is a case.

In recent years, deodorizing, antibacterial and antifouling actions using photocatalysts centering on titanium oxide have attracted attention. The action of such a photocatalyst is that electrons and holes generated by light incident on the photocatalyst react with oxygen and water on the photocatalyst surface to react with superoxide anions (.O ₂ ⁻ ) and OH radicals (active oxygen species). -OH) is generated.

In other words, the powerful oxidation reaction of active oxygen superoxide anion (• O ₂ ⁻ ) and OH radicals generated on the photocatalyst surface decomposes and removes organic chemicals in water, decomposes malodorous substances in the air, It can be used to purify the environment in various fields such as prevention. In particular, OH (hydroxy) radicals are the most reactive among the molecular species called so-called active oxygen, and are said to continue to be generated when light and water are supplied to titanium oxide, and to continue photocatalytic reactions. ing.

When manufacturing such a photocatalyst structure that fixes and supports the photocatalyst, it is difficult to directly attach the photocatalyst to the surface of the member (base material). Therefore, after mixing and kneading the photocatalyst with the binder, It is a common production method to apply a photocatalyst structure by coating on the surface or forming it into a sheet. However, in order to effectively exhibit the photocatalytic action, at least a part of the photocatalyst (particle) must be exposed from the surface of the member (base material) and be in a state in which light from the light source can be received. When manufactured by such a method, many photocatalysts were buried in the binder, and as a result, the photocatalyst could not be used effectively, which was uneconomical.

Therefore, as a method for forming a photocatalyst structure, a method of applying a photocatalyst to a member surface without a binder has also been proposed (Patent Document 1). Since it is limited to those exposed on the surface of the member (base material), the surface area of the member has to be increased, which is not sufficient economically and efficiently.

On the other hand, as an air cleaning device for purifying air using the above-mentioned photocatalyst, generally, an apparatus including at least a photocatalyst structure in which a photocatalyst is fixed and carried and a light source lamp in a casing is proposed. (Patent Documents 2 and 3). In these apparatuses, the photocatalyst structure is mainly of a filter type and is intended to purify by passing air through the member. For example, a honeycomb body or a nonwoven fabric on which the photocatalyst is fixed and supported (Patent Document 2). In addition, for example, an attempt has been made to increase the effective surface area by fixing and supporting a photocatalyst on the surface of a large number of lightweight powders to form a photocatalyst structure (Patent Document 3).

However, in the case of the filter-type air cleaning device, in order to increase the efficiency of the photocatalytic action, the surface area of the photocatalyst structure is increased, the number of members and the number of light sources (black lights) are increased, Bulky filters must be installed, and in the case of an aspect such as Patent Document 3, a large amount of a photocatalyst for covering the light-weight powder or a light-weight powder (photocatalyst structure) carrying the photocatalyst is used. The power required to control the turbulence was necessary, and the structure had to be enlarged and complicated.

As described above, the conventional air purifying apparatus using a photocatalyst has a big problem that the air purification efficiency is low as a whole. In order to further increase the efficiency, the surface area of the photocatalyst structure is increased and the number of each member is increased. As a result, the size of the apparatus inevitably increases, resulting in problems in terms of economy and space layout. In other words, it was not suitable for air purification at least in a narrow and poor environment such as in a temporary toilet.

Japanese Patent Laid-Open No. 2005-007216 Japanese Patent Laid-Open No. 08-121827 International Publication No. 2004/045660

An object of the present invention is to provide a photocatalyst structure and a method for producing the photocatalyst structure which are small in size and have a good photocatalytic efficiency, and have been made in view of the above-described problems. With this, it is possible to efficiently clean in a short time even air in a poor environment such as a temporary toilet, as well as a so-called quasi-closed space such as a living space or in a car, and it is low-cost and compact. An improved air cleaning device is provided.

To achieve the above object, a photocatalyst structure according to the first aspect of the present invention includes a sponge-like photocatalyst layer in which a large number of voids are formed. The photocatalyst layer includes a photocatalyst, a water-absorbing polymer, and It contains a water-soluble binder.

The photocatalyst may be titanium oxide, and the water-absorbing polymer is (1) a crosslinked acrylic polymer comprising a monomer selected from acrylic acid or a salt thereof, an acrylic ester and acrylamide. Or (2) a cross-linked product of isobutylene-maleic anhydride copolymer and (3) a cross-linked polyoxyethylene product.

The water-absorbing polymer may be a cross-linked acrylic polymer including a monomer selected from acrylic acid or a salt thereof, an acrylic ester and acrylamide.

The water-soluble binder may be a polyvinyl alcohol-based or vinyl acetate resin-based binder.

In order to achieve the above object, an air cleaning apparatus according to a second aspect of the present invention includes a photocatalyst structure according to the first aspect of the present invention, a first substrate on which the photocatalyst structure is disposed, and a light source. And a second substrate on which the light source is disposed, wherein the photocatalyst structure is disposed to face the light source.

The air purifier may further include a water-containing gel swollen by absorbing water.

The water-containing gel may absorb water to such an extent that the gel form can be maintained.

The water-containing gel may be stored in a storage container.

The air cleaning device includes a housing having a first opening for taking in air and a second opening for discharging air, and the photocatalyst structure disposed on the first substrate is disposed in the housing. A light emitting element that is the light source disposed on the second substrate is opposed in parallel to an axis connecting the first opening and the second opening, and the first substrate or The storage container storing the hydrated gel may be disposed on at least one of the back surfaces of the second substrate.

The storage container may include an inner container made of a mesh sheet for storing the hydrated gel and an outer container made of a perforated plastic for storing the inner container.

The outer container may be a set in which two upper and lower two sets are arranged in parallel on the back surface of the first substrate or the second substrate.

The upper end of the first or second substrate on the side where the outer container is disposed may be lower than the upper end of the two upper containers stacked.

The water-containing gel may be one that has absorbed an aqueous solution containing metal ions.

When the water-containing gel is dried, it may be regenerated and reusable by absorbing water.

In order to achieve the above object, a method for producing a photocatalyst structure according to a third aspect of the present invention is a method for producing a photocatalyst structure according to the first aspect of the present invention. A step of mixing and stirring a binder to prepare a first mixture, a step of mixing the first mixture and a water-absorbing polymer to prepare a second mixture, and molding the second mixture A step and a step of drying the molded second mixture.

The step of mixing the water-absorbing polymer may further include adding water.

In the present application, “cleaning” of air includes purification of air by decomposing / removing / adsorbing harmful substances such as odorous substances and bacteria in the air.

According to the present invention, by providing a photocatalyst layer in which a photocatalyst is uniformly dispersed and a large number of voids are formed, a photocatalyst structure having good photolysis performance can be provided, and a method for producing the photocatalyst structure therefor is provided. Can be provided. Furthermore, by providing the photocatalyst structure, it is possible to provide an air cleaning device that exhibits a suitable air cleaning function.

It is sectional drawing which shows typically the photocatalyst structure which concerns on embodiment. It is an image which shows the surface of the photocatalyst structure which concerns on embodiment. It is a side view of the air purifying apparatus concerning an embodiment. It is a top view of the air purifying apparatus which concerns on embodiment. It is a figure which shows the experimental result of the deodorizing effect with respect to the tobacco smoke of a photocatalyst structure. It is a figure which shows the experimental result of the deodorizing effect with respect to ammonia of a photocatalyst structure. It is a conceptual diagram which shows the type 1 gel typically. It is the conceptual diagram which shows the type 2 gel typically, and is a thing of the transition state from the type 3 to the type 1. FIG. It is a conceptual diagram of the type 3 hydrous gel based on this embodiment. It is an image of the mesh-shaped inner container of the water-containing gel which concerns on embodiment. It is an image of the plastic outer container of the water-containing gel which concerns on embodiment. It is the front view seen from the housing upper part of the improved type air purifying apparatus which concerns on embodiment. It is a figure which shows the flow (A, B, C, C ') of the airflow in the front view seen from the housing upper part of the improved type air purifying apparatus which concerns on embodiment. It is the side view seen from the water-containing gel storage container side of the improved type air purifying apparatus which concerns on embodiment.

Embodiments of a photocatalyst structure, a photocatalyst structure manufacturing method, and an air cleaning device according to an embodiment of the present invention will be described with reference to the drawings.

(1) Photocatalyst structure The photocatalyst structure 10 is provided with the photocatalyst layer 11 and the board | substrate 12, as shown in FIG.1 and FIG.2.

As shown in FIG. 1, the photocatalyst 11 a is dispersed in the photocatalyst layer 11. As the photocatalyst 11a, for example, titanium oxide is preferable, and visible light responsive and ultraviolet responsive titanium oxide (titanium dioxide), a mixture thereof, and the like can also be used. Further, as a result of the photocatalyst layer 11 being manufactured by a method described later, fine irregularities are formed on the surface as shown in FIGS. 1 and 2, and a large number of voids 11b are formed inside. The photocatalyst structure 11 is formed, for example, in a size of 15 cm × 15 cm and a height of 4 mm. The size and shape of the photocatalyst structure 11 can be appropriately changed depending on the application to be used, the required performance, the size of an air cleaning device 20 using the photocatalyst structure 11 (described later), and the like.

As the support substrate 12, for example, cork material, veneer, plywood, paper, film, wire mesh and the like can be used. In addition, when air exists in the surface which contacts the photocatalyst layer 11, since the photodecomposition performance of the photocatalyst layer 11 can be improved, when higher photodecomposition performance is calculated | required, a cork material is used as the support substrate 12. It is preferable. The support substrate 12 may be omitted and only the photocatalyst layer 11 may be used. If a metal mesh made of stainless steel or the like is used as the support substrate 12, light can be irradiated from both sides of the photocatalyst layer 11, and the photocatalyst layer 11 is held by the metal mesh, so that it is easy to maintain a sheet-like shape. ,preferable. In this case, the photocatalyst layer 11 may be formed on one surface of the wire mesh, or the photocatalyst layer 11 may be formed on both surfaces of the wire mesh.

Thus, the photocatalyst layer 11 is formed in a sponge shape and includes a large number of voids 11b, whereby the area where the photocatalyst 11a contained in the photocatalyst layer is in contact with air can be increased. In addition, the photodecomposition efficiency of the photocatalyst can be increased (see the experimental examples described later).

(1) The area where the photocatalyst 11a comes into contact with air containing foul odors or bacteria and the like is remarkably increased, and the photolysis efficiency of the photocatalyst can be increased. (2) If the surrounding humidity is high, moisture important for photocatalytic action can be trapped from the air together with odors and bacteria in the air. The efficiency of sterilization and the like is improved. And (3) By improving the photolysis efficiency, the size of the photocatalyst structure 10 can be reduced, and the air cleaning device 20 can be made compact.

In the above-described embodiment, the photocatalyst structure is described as an example of being formed in a sheet shape. However, the present invention is not limited to this, and the shape is not limited to this, for example, a three-dimensional shape such as a honeycomb body or a fiber shape. May be.

(2) Method for Producing Photocatalyst Structure Next, a method for producing the photocatalyst structure 10 will be described.

First, visible light or ultraviolet responsive titanium oxide powder is added to a water-soluble binder, and stirred and mixed to prepare a mixed solution. The water-soluble binder is not particularly limited, and may be, for example, a paste-like vinyl acetate resin emulsion bond or a polyvinyl alcohol (PVAL) liquid paste. PVAL binders are preferred because they are less sticky and have higher fluidity than vinyl acetate binders, and are easy to apply on the substrate and facilitate the manufacturing process.

Next, the water-absorbing polymer is added to the mixed solution, and stirred and mixed with a mixer or the like. At this time, water may be added as appropriate. Although there is no restriction | limiting in particular as a water absorbing polymer, From the viewpoint of the water absorbing property and stability of aqueous gel, (1) It is comprised including the monomer chosen from acrylic acid or its salt, acrylic acid ester, and acrylamide. One or more selected from a crosslinked acrylic polymer, (2) a crosslinked product of isobutylene-maleic anhydride copolymer, and (3) a crosslinked polyoxyethylene are preferred. In addition, acrylic systems having a molecular structure in which polymer chains having hydrophilic groups in the side chains are cross-linked, such as acrylate salts (cross-linked acrylic acid polymer sodium salts, cross-linked polyacrylic acid polymer calcium salts). It may be a polymer.

For example, when titanium oxide, a water-soluble vinyl acetate resin emulsion bond, and a water-absorbing polymer are mixed with a mixer or the like, the water-absorbing polymer begins to absorb water and swells in a gel form. The titanium oxide powder coexisting in the emulsion adheres to the inside and outside of the gel and is kneaded.

Subsequently, a mixed liquid in which the water-absorbing polymer is mixed is applied onto the substrate and pressed from above the mixed liquid, or the mixed liquid is passed between two pairs of rolls, for example, to form a sheet.

As described above, a cork material is suitable for the support substrate 12, but veneer, plywood, paper, film, or the like may be used. Further, the sheet may be peeled from the substrate by making the substrate a plate using a metal such as iron, copper, stainless steel, aluminum, or the like.

Subsequently, the mixed solution formed into a sheet is naturally dried at room temperature. When dried, when the moisture evaporates from inside and outside the gel, the titanium oxide powder kneaded in the gel remains inside and outside the gel. As the drying progresses further, the water-absorbing polymer mixed gel becomes smaller and becomes a sponge structure maintaining elasticity.

At this time, it is preferable to use sun-drying or hot-air drying, because it is more effective to increase the drying efficiency and forcibly evaporate the water absorbed by the water-absorbing polymer. When the substrate is made of metal, it is peeled off from the substrate after drying. In this way, a photocatalyst structure is manufactured.

According to the above production method, the photocatalyst is mixed with a water-soluble binder, and after the water-absorbing polymer is added, the water is evaporated, so the kneading step, the drying step, etc. are simple and safe. The photocatalyst layer 11 including the photocatalyst 11a can be formed in a porous sponge shape having voids 11b without cost. Thereby, the area which the photocatalyst 11a contacts with air can be enlarged, and the photolysis efficiency of the photocatalyst structure 10 can be improved (refer the below-mentioned experimental example).

(3) Air purifying apparatus provided with photocatalyst structure Next, the embodiment of the air purifying apparatus provided with the said photocatalyst structure is demonstrated.

<< Air Cleaner >>
As shown in FIG. 3A, for example, the air cleaning device 20 includes a photocatalyst structure 10, a support substrate 21 for the photocatalyst structure, an LED (Light Emitting Diode) 22 as a light source, and a light source. And a counter substrate 23 for facing the structure.

The support substrate 21 and the counter substrate 23 are each formed of a metal plate, and column portions 24 made of, for example, bolts or the like may be provided at four corners of the support substrate 21 and the counter substrate 23 as shown in FIG. 3B. . By the pillar portion 24, the support substrate 21 and the counter substrate 23 are arranged at a predetermined distance apart as shown in FIG. 3A.

The light source 22 may be an LED, for example, a diode having an ultraviolet peak wavelength of 375 nm and an intensity of 0.38 mw / 1 cm ² is used. As shown in FIG. 3B, about 42 LEDs 22 are arranged on a base of 15 cm × 15 cm, for example. LED22 is arrange | positioned in the surface facing the photocatalyst structure 10 of the opposing board | substrate 23, and is connected to the power supply which is not shown in figure. In an embodiment, the LED 22 and the photocatalyst structure 10 are spaced apart by about 1 mm. The LED 22 can be appropriately changed depending on whether the light that the photocatalyst 11a dispersed in the photocatalyst structure 10 responds is visible light or ultraviolet light.

In the above air cleaning device 20, the case of using an LED has been described as an example. In addition, the number and arrangement method of the photocatalyst structure and the light source, the distance separating the light source and the photocatalyst structure, the intensity of the ultraviolet light, and the like can be appropriately changed. Furthermore, in the above-described embodiment, the photocatalyst structure has been described by taking an example in which the photocatalyst structure is formed in a sheet shape. The present invention is not limited to the above-described embodiments, and various modifications and applications are possible.

<< Experiment Example >> Air Cleaner (Experiments 1-13)
The experiment result regarding air cleaning in the embodiment of the air cleaning apparatus including the photocatalyst structure is shown below. In each of the following experiments, the odor was measured using GASTTECH CO. The odor monitor (GT300-VOC model) manufactured by LTD was used. Here, the odor monitor value is a value obtained by quantifying a change in the concentration of a hydrocarbon compound or the like in the air with the fresh air as 1, and for example, public toilets generally have 10 Numerical values of -40, sewage ports 20-40, and smoking rooms 30-90 are shown.

<Deodorization experiment in a closed temporary toilet> Experiments 1 to 3, Table 1
In the experiment, as one embodiment, a photocatalyst structure is manufactured by the above-described manufacturing method in an amount shown in Experiments 1 to 3 in Table 1 with ultraviolet-type titanium oxide, a water-soluble binder, and a water-absorbing polymer. Air purifiers using these photocatalyst structures were produced. As the UV-type titanium oxide, ST-21 titanium dioxide manufactured by Ishihara Sangyo Co., Ltd. is used, and as the water-soluble binder, a vinyl acetate resin emulsion bond (manufactured by Konishi Co., Ltd.) is used. An acid polymer partial sodium salt cross-linked product (Kennis Co., Ltd.) was used. Moreover, the air purifier was made into a compact size of about 17 cm × 17 cm and a height of about 37 mm. An LED was used as the light source in the air cleaning device, and 42 diodes having an ultraviolet peak wavelength of 375 nm and an intensity of 0.38 mW / cm ² were arranged on a 15 cm × 15 cm substrate in a 7 cm width. Moreover, it arrange | positioned so that the distance of a photocatalyst structure and LED may be about 1 mm. The photocatalyst structure was formed in a size of 15 cm × 15 cm and a height of 4 mm.

This air purifier was set in a closed temporary toilet (smell monitor value is 22.5) installed at a temperature of 33.5 ° C. and having a space volume of 1.5 m ³ . Two hours after the start of the operation of the air purifier, the odor in the temporary toilet was measured by the odor monitor.

<Deodorization experiment in a closed temporary toilet> Experiments 4, 5 and Table 2
(When no water-absorbing polymer is added)
In Experiments 4 and 5, photocatalyst structures were prepared in the same manner as in Table 1 (Experiments 1 to 3) except for the amounts shown in Table 2 (no water-absorbing polymer added). That is, in Experiments 4 and 5, as in Experiments 1 to 3, UV-type titanium oxide powder was used as the photocatalyst, vinyl acetate resin emulsion bond was used as the binder, and the titanium dioxide powder was 50 g and 5 g, respectively. construction area of the ^structure, so that the 2338cm ^2, 300cm 2, was prepared. The experimental conditions in the temporary toilet are the same as in Experiments 1 to 3 above. In each of Experiments 4 and 5, one black light having an intensity of 5 mw / cm ² was irradiated at a distance of about 5 mm.

In Experiment 4 shown in Table 2, the photocatalyst layer did not develop a blue color even when irradiated with ultraviolet rays, and the photocatalyst was not functioning. In Experiment 5, it was confirmed that the photocatalyst layer was colored blue by ultraviolet irradiation and the photocatalyst was functioning, but the photolysis efficiency of titanium oxide was low.

The results of Experiments 1 to 5 are summarized as follows in relation to the content of titanium oxide per construction area and the odor monitor value.
Titanium oxide content / construction area Odor monitor value (mg / cm ² )
Experiment 1 1.87 1
Experiment 2 3.69 1
Experiment 3 5.56 1
Experiment 4 (Comparative Example) 21.39 5
Experiment 5 (comparative example) 16.67 10

From this result, the odor monitor in the temporary toilet was 22.5 before the experiment, whereas in the comparative examples (experiments 4 and 5) in which the water-absorbing polymer was not added, the deodorizing effect was not so much. On the other hand, in each case of the photocatalyst structures (Experiments 1 to 3) of the present application, the odor monitor value in the temporary toilet showed 1 (fresh air level). That is, the air cleaner provided with the photocatalyst structure yielded an exceptional effect that has made the odor in the temporary toilet odorless in about 2 hours.

This effect is presumed that the area where the photocatalyst and air are in contact with each other is greatly increased by the large number of voids formed in the photocatalyst structure, and the photolysis efficiency is remarkably improved. That is, in the embodiment according to the present invention, it is possible to obtain a higher photolysis efficiency with a smaller amount of titanium oxide, with a smaller construction area, thereby reducing production costs and purifying air with a more compact size. It can be a device.

<Deodorization experiment in closed temporary toilet> Experiment 6, Table 3
(When using visible light responsive titanium oxide)
Next, Experiment 6 is an experimental result when visible light type titanium oxide is used as a photocatalyst. In Experiment 6, a photocatalyst structure manufactured by the same method as Experiments 1 to 3 using a visible light responsive titanium oxide powder (Ishihara Sangyo Co., Ltd., MPT-623) surface-treated with a platinum compound, and 10,000 Lux An air cleaning device comprising a 9W LED that emits visible light was created. Experimental conditions are the same as in Table 1. As shown in Table 3, the odor monitor value of the temporary toilet was 1 in the measurement after 2 hours (see Table 3).

As described above, in the case of visible light type titanium oxide as well as ultraviolet type titanium oxide, if the photocatalyst structure according to the present invention is manufactured and the air purifying device according to the present invention is created, even a temporary toilet with strong odor can be used. Can be odorless.

<Deodorization experiment in a closed temporary toilet> Experiments 7 and 8, Table 4
(When using other water-absorbing polymers)
Next, Table 4 shows the results of Experiments 7 and 8 using a polyacrylic acid polymer partial calcium salt crosslinked product as a water-absorbing polymer. Here, 2 g of a water-absorbing polymer made of a cross-linked polyacrylic acid polymer calcium salt manufactured by Meviol Co., Ltd. was used. The titanium oxide and the binder were the same as those in Experiments 1 to 3, and the construction area was also 225 cm ² . When this photocatalyst structure was set in a temporary toilet in the same manner as in Experiments 1 to 3 and irradiated with a 20 W black light having an intensity of 1 mw / 1 cm ² , the odor monitor value showed 1. Thereby, even if the polyacrylic acid polymer partial calcium salt cross-linked product was used as the water-absorbing polymer, the temporary toilet with strong odor could be made odorless.

<Deodorization experiment in closed temporary toilet> Experiment 9, Table 5
(When using other water-soluble binder)
Next, an experiment was conducted using a PVAL-based binder (liquid glue ADMIGHT manufactured by Mitsue Corporation) as a water-soluble binder. The conditions were the same as in Experiments 1 to 3, except that the binder was PVAL. When this photocatalyst structure was irradiated with a diode having an ultraviolet peak wavelength of 375 nm and an intensity of 0.38 mW / 1 cm ² , the odor monitor value still showed 1. Thereby, it was shown that the same effect was obtained even when a PVAL binder was used.

Compared with vinyl acetate, PVAL binders have less stickiness and high fluidity, making it easier to apply on the substrate, making manufacturing easier, and reducing drying time. This is a preferred embodiment.

Experiments

10, 11, Table 6
(When using a non-water-soluble binder)
Next, an experiment was conducted using an acrylic acid binder that is not water-soluble as the binder. In Experiment 10, an acrylic emulsion adhesive FL-200 manufactured by Konishi Co., Ltd. was used, and in Experiment 11, an acrylic acid adhesive EM341 manufactured by Cemedine Co., Ltd. was used. Except for the binder, all were the same as in Experiments 1 to 3.

In each of

Experiments

10 and 11, the mixed solution was sticky, and after the formation, it took 1 week or more to dry, and even when irradiated with ultraviolet rays, no color was developed and the photocatalyst did not function. Therefore, when an acrylic acid binder is used, a photocatalyst structure cannot be produced.

Next, an experiment was performed on the deodorizing effect of the air cleaning device of this embodiment using cigarette smoke and ammonia water.

<Deodorizing effect on cigarette smoke> Experiment 12, FIG.
In this deodorization experiment, a 32.4 L sealed plastic container was filled with smoke of two cigarettes. The materials used for producing the photocatalyst structure were the same as those in Experiments 1 to 3, and 79 g of vinyl acetate bond, 6 g of titanium oxide and 6 g of water-absorbing polymer were used, and the construction area was 570 cm ² . The photocatalyst structure was irradiated with black light having a peak wavelength of 360 nm and an intensity of 5 mW / cm ² .

As shown in FIG. 4, the odor monitor value in the case of using the photocatalyst structure of the present invention was a high value of 97 before the experiment, but it was 60 after 30 minutes and 35, 1. After 5 hours, it decreased to 15 after 2 hours and to 7 after 2 hours. On the other hand, the odor monitor value when the photocatalyst structure of the present invention is not used is initially 97, 97 after 30 minutes, 96 after 1 hour, 94 after 1.5 hours, 94 after 2 hours. 92, almost flat.

From the above, it was found that the air purifying apparatus of this embodiment has a deodorizing effect with respect to tobacco smoke.

<Deodorizing effect on ammonia> Experiment 13, FIG.
In this deodorization experiment, as in the deodorization experiment using cigarette smoke, a 32.4 L plastic sealed container was filled with ammonia at a concentration of 2500 ppm, and the photocatalyst structure had a peak wavelength of 360 nm and an intensity of 5 mW. / Cm ² of black light was irradiated. In this experiment, the materials used for producing the photocatalyst structure are the same as those in Experiments 1 to 3, and 79 g of vinyl acetate-based bond, 6 g of titanium oxide, water-absorbing polymer (cross-linked acrylic acid polymer partial sodium salt) ) 6 g and the construction area was 570 cm ² .

As shown in FIG. 5, the odor monitor value when the photocatalyst structure of the present invention was used was a high value of 83 before the experiment, but it was 52 after 30 minutes, 26, 1. After 5 hours, it decreased dramatically to 4 and after 2 hours, it decreased to 1 and decreased to an odorless level. On the other hand, when the photocatalyst structure of the present invention is not used, the odor monitor value is initially 83, 83 after 30 minutes, 82 after 1 hour, 80 after 1.5 hours, 80 after 2 hours. At 80, there was little change.

From the above, it was found that the air purifier of this embodiment clearly has a deodorizing effect on ammonia. Since ammonia is one of the causative substances of toilet odors, it was confirmed that the air purifier equipped with the photocatalyst structure of this embodiment is effective in deodorizing temporary toilets.

(4) Improved air cleaning device further provided with a water-containing gel Next, an improved air cleaning device whose air cleaning efficiency has been remarkably improved by adding a water-containing gel to the air cleaning device of (3) will be described. .

<< Improved air cleaning device >>
For example, as shown in FIG. 9A, the improved air cleaning device includes a photocatalyst structure 10, a support substrate 21 that supports the photocatalyst structure 10, and an LED (light source) that faces the photocatalyst structure support substrate 21, as shown in FIG. 9A. ) 22, a counter substrate 23 that supports the LED (light source) 22, and further includes a hydrogel 32 and a storage container 33. The housing 40 includes an air intake port 35 in the vicinity of the fan 9 and an air exhaust port 36 on the opposite side. The counter substrate 23 that supports the LED (light source) 22 and the hydrated gel storage container 33 are disposed opposite to each other on both sides of the support substrate 21 that supports the photocatalyst structure 10. Instead of this, the support substrate 21 that supports the photocatalyst structure 10 and the counter substrate 23 that supports the LED (light source) 22 may be replaced, or the support substrate 21 that supports the photocatalyst structure 10 and the LED (light source). ) 22 may be arranged on both sides of the water-containing gel container.

The hydrogel storage container 33 includes, for example, an inner container 33a formed of a mesh sheet as shown in FIG. 7 and an outer container 33b made of perforated plastic as shown in FIG. The inner container 33 a containing the hydrated gel 32 is placed in the outer container 33 b, arranged so as to be adjacent to the back surface 21 b side of the support substrate 21 of the photocatalyst structure 10, and ventilated by the suction fan 9.

As shown in FIGS. 9A and 9B, the support substrate 21 is preferably configured so that air containing moisture (humidity) evaporated from the water-containing gel 32 by ventilation is from the water-containing gel storage container 33 (33a, 33b) side to the LED 22 side. In order not to flow excessively, it may be arranged to serve as a partition wall. Separately, a partition wall may be provided between the support substrate 21 and the storage container 33.

As shown in FIG. 9B, when the improved air purifying apparatus 30 is started to operate, air enters from the air intake port 35 by the fan 9, is divided inside, and merges in the vicinity of the air discharge port 36. Arise. This air flow mainly comprises an air flow A passing between the photocatalyst structure 10 and the LED 6 and an air flow B passing through the hydrated gel storage container 33 side. In addition to that, a description will be given later. As described above, an air flow C from the hydrogel container 33 side to the photocatalyst structure 10 is also generated.

In one embodiment, the support substrate 21 in the apparatus has an area of 160 cm ² formed into a sheet using MPT-623 powder surface-treated with a platinum compound using visible light responsive titanium oxide manufactured by Ishihara Sangyo Co., Ltd. A photocatalyst structure 10 is used. The counter support substrate 23 is provided with a 9.5 cm × 14.5 cm LED substrate in which 42 2w LEDs are arranged. These LEDs irradiate the photocatalyst structure 10 with 15000 Lux visible light.

In the apparatus, a 12 V DC suction fan 9 may be provided at a distance of about 0.5 cm to 2 cm from the set position of the hydrogel container 33 in order to suck air. Air outside the apparatus is sucked into the improved air cleaning apparatus 30 simultaneously with the rotation of the fan 9, and the wind speed is, for example, about 2 m / sec to 3 m / sec.

The hydrogel 32 is first stored in the inner storage container 33a, and further stored in the outer storage container 33b. As shown in FIG. 7, the inner storage container 33a is a cage made of, for example, a mesh sheet made of polyamide such as thermoplastic resin, polypropylene, or polyethylene. For example, as shown in FIG. 8, the outer storage container is a perforated plastic container having a large number of holes 33b1 (a commercially available polystyrene deep-angle container (7.4 cm × 11.3 cm × 9 manufactured by Inomata Chemical Co., Ltd.)). .8 cm)). The reason why the hydrated gel 32 is stored in the inner storage container 31 of such a mesh sheet is that when the hydrated gel is directly stored in the plastic outer storage container 32, the shape of the hydrated gel 32 in contact with the inner wall of the container 32 is crushed. Because it will end up.

In one embodiment, the inner storage container 33a stores a hydrogel 32 (480 g) whose water absorption is 20 times its own weight. The outer storage container 33b is preferably arranged in two rows and one row at a position adjacent to the back surface 21b side of the support substrate 21 (see FIGS. 9A, 9B, and 10). In this case, for example, the weight of the four gel outer storage containers 33b is 1920 g, and the total surface area of the containers is 1452 cm ² .

<Method for creating hydrogel>
The “water-containing gel” according to the present invention is a gel in which the powder of the water-absorbent resin 1 is swollen with water to such an extent that its form can be retained by water absorption. In the state where a moderate air gap is secured between the gels (type 3, see below) (see FIG. 6A). The creation method is described below.

First, the water-absorbing resin is not particularly limited, but includes (1) a monomer selected from acrylic acid or a salt thereof, an acrylate ester and acrylamide from the viewpoint of water absorption and stability of the aqueous gel. One or more selected from (2) a crosslinked product of an isobutylene-maleic anhydride copolymer and (3) a crosslinked polyoxyethylene are preferable.

Examples of water-absorbing resins that are generally marketed include, for example, acrylate-based, polyacrylic acid polymer partial sodium salt cross-linked products, polyacrylic acid polymer partial calcium salt cross-linked products, There are water-absorbing resins having a molecular structure in which polymer chains are cross-linked, and the shape is usually powder or granular. Therefore, before starting the experiment, the particle size distribution of the original water-absorbing resin before water absorption was examined. A sieve was prepared with a stainless mesh of 30 to 150 mesh, and as an example, the particle size distribution of a crosslinked acrylic acid polymer sodium salt resin (Kenith Corp., 400 g) used in the following water absorption experiment was examined. In the following, for example, “30 # on” means a case where a 30-mesh wire mesh is not passed, and “150 # pass” means a case where a 150-mesh wire mesh is passed.

(Particle size distribution of water-absorbent resin, screening experiment) Preliminary experiment, Table 7

As a result, a relatively large size that does not pass more than 0.288 mm (50 wire mesh) accounted for 72% or more of the total weight ratio (wt%). The experiment was decided to proceed.

<< Experimental Example >> Hydrous Gel Experiments 14-20, Improved Air Cleaner Related Experiments 21-24
As described above, the water absorption experiment and the preparation of the water-containing gel 32 were performed without sieving the water absorbent resin, and in the following experiments, the water absorption speed was different depending on the particle size, and the water was absorbed with care. . That is, the water-absorbent resin 1 is powder or granular, and in the case of the preliminary experiment, the size is relatively large and is about 0.6 mm, and the small size is about 0.1 mm. For example, when comparing the water absorption speed of 30 # on (0.560mm) and 150 # on (0.104mm) water-absorbing resins separated by sieving and absorbing water 40 times the amount of resin, 1.168cc / sec, 150 # on resin, 4.516cc / sec, there was a difference of 4 times or more.

Therefore, when preparing a hydrous gel without sieving the water-absorbent resin, a container for containing water or water containing metal ions, etc., is shallow with a bottom depth of about 4 to 5 cm, for example, and a frontage ( For example, it is preferable to use a wide square dish of 22 × 31 cm), and the water-absorbing resin 1 may be introduced so as to be uniform throughout the square dish. If the water is absorbed in this way, there is little variation due to the difference in absorption speed, and the water-containing gel 32 having a good water absorption can be obtained.

<Relationship between water absorption amount and form of water absorption gel> Experiment 14, Table 8
As the water-absorbent resin 1, a cross-linked acrylic acid polymer sodium salt (Kenith Co., Ltd.) having a powder or granular shape was used, and purified water was used as the water 2. The observation results of the amount of water absorption with respect to its own weight and the form of the gel are shown below.

* 1: (Type 1) A large amount of water absorption causes the gel to collapse and become agar-like, and the possibility of water leaching is high.
* 2: (Type 2) Transition stage from Type 3 to Type 1 * 3: (Type 3) hydrous gel 32
* 4: (Type 4) In the case where the water absorption rate of the resin is faster than the resin charging rate, the gel may have non-uniform water absorption.

The following is a summary of changes in gel morphology when the water absorption against its own weight is increased stepwise under the experimental conditions of Experiment 14 (see FIGS. 6A to 6C).
(A) When water absorption is about 100 times or more of its own weight, each gel will swell too much and it will become an agar-like gel in the state where the shape collapsed entirely (refer FIG. 6A) (type 1).
(B) When the water absorption is about 80 to about 90 times its own weight, the presence of water in the swollen gel can be clearly seen. Deformation (see FIG. 6B) (type 2).
(C) When the water absorption is about 12 to about 70 times its own weight, the water-absorbing resin is a gel swollen to such an extent that the water absorption resin can retain its form. A gap is secured (see FIG. 6C). This is a preferred embodiment as an adsorbent (water-containing gel 32, hereinafter also referred to as a water-containing gel) because the gel shape is maintained while water is appropriately contained by water absorption, and a gap is secured between the gels. ).
(D) When the water absorption is about 10 times or less of its own weight (resin amount), the difference in water absorption is large, and the gel tends to be unevenly swelled (type 4).

In order for the hydrogel 32 to function as an adsorbent, it is essential to have adsorption performance, but in addition to this, it is also necessary that the aqueous solution does not ooze and the gel form is maintained.

In other words, the “water-containing gel” (32) referred to in the present application is a gel in which the water-absorbent resin of type 3 is swollen to the extent that the water-absorbent resin can retain its form due to water absorption, even if stored in a container. Since a gap is secured between them, this is a preferred embodiment as an adsorbent. The degree of water absorption (moisture content) of the water-containing gel 32 (also simply referred to as a water-containing gel) can be appropriately adjusted depending on the type of the water-absorbing resin used so as to satisfy the above type 3 characteristics.

<Antifungation experiment of hydrous gel> Experiment 15, Table 9
Black mold or the like may occur during use or storage of the hydrogel 32 obtained in Experiment 14. As a countermeasure, it is most preferable to use an aqueous solution containing silver ions, copper ions and the like. As a result of standing test using a 200 ml bottle, when the tap water was used for water absorption, black mold was generated in the water-containing gel 32 in about one week, but the above antibacterial metal ion water was used. In this case, no mold was observed even after 2 months.

* 1: Water-containing gel that absorbs tap water 30 times its own weight * 2: Water-containing gel that absorbs silver ion 0.1 ppm aqueous solution 30 times its own weight * 3: Water-containing gel that absorbs silver ion 0.25 ppm aqueous solution 30 times its own weight * 4: A hydrous gel that absorbs 100 ppm of silver ion water 30 times its own weight.

<Sustained deodorizing effect of hydrous gel> Experiments 16 and 17, Tables 10 and 11
Next, the experimental result regarding the deodorizing action of the hydrogel prepared by the above method is shown below.

In this experiment, the water-containing gel 32 produced from the water-absorbent resin 1 was used, and compared with granular white birch WH2C8 / 32 coconut shell activated carbon (Nippon Enviro Chemicals Co., Ltd.). The experimental box used was made of a glass plate having a length of 45 cm, a width of 45 cm, and a height of 60 cm, and its volume was 121.5 L. As the storage container, a 15 cm × 2.5 cm × 15.5 cm (volume 581.25 cm ³ , surface area 617 cm ² ) made of 50 # stainless wire mesh was used. A coconut shell activated carbon amount of 240 g or a water-containing gel of 377 g having a water absorption ratio of 30 times was placed in a storage container and set in a test box. Ammonia water, which is also one of the odorous substances, was dropped onto the floor in the experimental box so that the ammonia concentration was 1400 ppm. The experiment was conducted for 3 days, once a day for 3 hours, without replacing the hydrogel or coconut shell activated carbon. For the measurement of the odor monitor value in the experiment box, the same odor monitor as in the above experiments was used.

(Experiment 16) Deodorizing effect of coconut shell activated carbon (comparative example)

(Experiment 17) Deodorizing effect of hydrous gel

In the case of the coconut husk activated carbon of Experiment 16 (comparative example), it seemed that the deodorizing effect was almost smoothly performed on the first day. The deodorizing function is low, whereas the hydrogel of Experiment 17 shows a considerable deodorizing effect after 1 hour of use, and the deodorizing function is reduced after the second day. Therefore, it can be said that the deodorizing efficiency and the deodorizing function of the hydrated gel are significantly higher than that of coconut shell activated carbon.

<Comparison of deodorizing effect with water-absorbing gels of types 1 to 4> Experiment 18 (square dish), Table 12
Next, a deodorizing effect experiment was conducted on the water-absorbing gel (types 1 to 4, see Experiment 14 above) when the water absorption relative to its own weight was 4 to 180 times. A square dish was used as a container for the swollen gel after water absorption, and the water-absorbing gel was spread so that the surface area became 700 cm ² . The experimental box used is the same as described above. In this experiment, a case where no water-absorbing gel was applied was prepared as a blank test (comparison experiment). The result of the odor monitor value at each elapsed time after dropping the ammonia concentration of 1400 ppm to the experimental box is shown below.

(Experiment 18)

100-180 times water absorption against its own weight (Type 1)
80 times the water absorption against its own weight (Type 2)
20-60 times water absorption against its own weight (Type 3)
4 times the water absorption against its own weight (Type 4)

In the above water absorption experiment, gels that are classified as type 1 to type 2 and whose water absorption is 80 times and 100 times their own weight clearly show water seepage, especially 180 times that is classified as type 1. The gel was easily deformed even in a square dish, and a significant amount of water flowed out. As for the deodorizing effect, the 180-fold gel shows some deodorizing effect as compared with the blank test, but the effect is small. Overall, the lower the degree of water absorption, the faster the deodorizing effect. In this experiment, the gel with the lowest water absorption (4 times its own weight, type 4) has the fastest deodorizing effect, but it has a low water absorption and immediately dries. In addition, such an effect cannot be obtained when it is continuously used.

<Comparison of construction area and deodorizing effect> Experiment 19 (square dish), Table 13
Next, using water-containing gel 32 (type 3) whose water absorption is 20 times its own weight, the construction area was gradually increased from 380 cm ² to 1785 cm ^2, and an experiment was conducted to see the deodorizing effect. The experimental box was the same as above, but the ammonia water was dropped to a high concentration of 2500 ppm. For comparison of the hydrogel 32, tap water filled in a square dish was used as a blank test (construction area 612 cm ² ). The results are shown below.

(Experiment 19)

From the results of the experiment 19 (Table 13), it was confirmed that the deodorizing effect increased as the construction area (380 cm ² to 1785 cm ² ) of the hydrogel was increased.

<Difference in water-absorbent resin and deodorizing effect> Experiment 20 (square dish), Table 14
Next, as a water-absorbent resin, a test product (1) a cross-linked acrylic acid polymer sodium salt made by Kennis Co., Ltd. and a test product (2) a cross-linked polyacrylic acid polymer partial calcium salt made by Meviol Co., Ltd. Used to compare the deodorant effect. The water absorption magnification was 20 times its own weight, the construction area was 1190 cm ² , and ammonia water was dropped at 2500 ppm. Table 14 shows the result of the odor monitor value for each elapsed time.

(Experiment 20)

From the above results, even when (i) a polyacrylic acid polymer partial calcium salt cross-linked product is used as the water-absorbing resin, the odor monitor value can be obtained in a short time as in the case of (a) the acrylic acid polymer partial sodium salt cross-linked product. The effect of purifying by clean air level (1) could be obtained.

<< Instantaneous Deodorizing Effect of Improved Air Cleaner >> Experiment 24, Table 15
With respect to the improved air cleaning device 30 including the photocatalyst structure and the water-containing gel, experiments for examining the effect were performed (Experiments 21 to 24). According to the production method of Experiment 14 and the like, the storage container “4 sets” containing the water-containing gels in Table 15 creates a water-containing gel 32 having a water absorption ratio of 20 times its own weight and stores them in the four storage containers 33 (see FIG. 10) means that it is installed in the improved air cleaning device 30 (FIGS. 9A and 9B). Note that purified water is used to absorb the water-containing gel.

The improved air cleaning device 30 was placed in the 121.5 L capacity test box used in Experiments 16 and 17, and the experiment was performed under the following conditions. After dropping ammonia water having a concentration of 500 ppm into the experimental box, the fan 9 was operated, and the odor in the experimental box was measured with an odor monitor over time. Here, the “LED power supply ON state” means that the LED is irradiated and the photocatalyst structure 10 is under the condition of exerting the photocatalytic function, and the “LED power supply OFF state” means that the LED is not irradiated. This means that the photocatalyst structure 10 is under conditions that do not exhibit the photocatalytic function.

In the air cleaning apparatus having the photocatalyst structure of the previous example, a deodorizing effect was obtained when the air level became clean after about 2 hours, but in the example of the improved air cleaning apparatus of this time, A special deodorizing effect is obtained in a much shorter time, and the odor monitor values after 11 minutes are shown below.

(Experiments 21-24)

According to the above experiment, the improved air cleaning device 30 using the photocatalyst structure 10 (LED / ON state) and the hydrated gel 32 in combination (Experiment 4) is an air (smell) filled with ammonia after only 11 minutes of operation. The monitor value 84) showed an amazing air cleaning effect that it can be deodorized and cleaned to a level equivalent to clean air (odor monitor value 1).

On the other hand, in the experiment in a short time of 11 minutes, the water-containing gel 32 alone (Experiment 3) decreased to level 13, but the photocatalyst structure 10 (LED / ON state) alone (Experiment 2) He stayed at 63.

From the above results, in the improved air cleaning apparatus, (1) the water-containing gel has excellent adsorption that it can trap odors and the like in a shorter time by having water content and gaps between the gels. On the other hand, although (2) the photocatalyst structure 10 has a small deodorizing effect in a short time, it is about 2 hours from the experiment (experiments 1 to 13) of the air cleaning device provided with the photocatalyst structure 10 described above. If it passes, it has the performance which can clean air continuously.

(3) When the photocatalyst structure 10 (LED / ON state) and the hydrogel 32 are used in combination (Experiment 24, odor monitor value: 1), the photocatalyst structure (LED / ON state) alone (experiment) 22 and odor monitor value: 63) Of course, it is more effective than the case of water gel alone (Experiment 23, odor monitor value: 13). Purified to level. This point was the same result even if it experimented repeatedly.

In the case of a hydrogel alone (such as Experiment 23), even if the air is deodorized to some extent, the ammonia odor remains in the ammonia experiment, and in the cigarette smoke experiment, the odor remains in the hydrogel and remains in the gel itself. Although the odor remains, in the case of an improved air cleaning device (such as Experiment 24) in which the photocatalyst structure 10 and the hydrated gel 32 are used in combination, the odor does not remain in the hydrated gel 32, which is good. It was. This is also an important effect for regenerating and reusing the hydrogel 32 described below.

From the above, it was found that the air purification effect of the improved air cleaning device 30 using the photocatalyst structure 10 and the hydrogel 32 according to the present invention in combination is larger than expected.

This extraordinary effect of the improved air cleaning device in which the photocatalyst structure and the water-containing gel are juxtaposed is not only the sum of the effects of each of the photocatalyst structure and the water-containing gel, but also a combination of both as described below. It seems that there are some complex effects or synergistic effects.

The inside of the housing 40 of the improved air cleaning device 30 is partitioned into a partition 37 on the photocatalyst structure 10 side and a partition 38 on the water-containing gel storage container 33 side by a partition wall (or support substrate 21) (FIG. 9B). As shown in FIGS. 9B and 10, the upper end b of the partition wall is slightly lower than the upper end a of the storage container 33 so that air flows through the upper portion of the housing 40 (airflow C, C ′) (in this embodiment, About 5 mm), which is set higher than the upper end c of the hole at the highest position of the plastic container. When the operation of the improved air cleaning device 30 is started, the air that has flowed into the device by the fan 9 is mainly divided into an airflow A flowing on the compartment 37 side and an airflow B flowing on the compartment 38 side by the partition wall. However, not only that, another type of airflow flowing between

compartments

37 and 38 was actually observed. In FIG. 9B, this is shown as airflows C and C ′.

In the experiments 21 to 24, the humidity of the compartment 38 on the hydrated gel container side of the improved air purifier was increased to about 90% as the moisture of the hydrated gel evaporated by the fan. Note that the humidity outside the apparatus in the experimental box was about 68%.

Considering the above results comprehensively, in addition to the following 1), 2), in addition to the following 1), 2), this improved air cleaning device 30 comprising a photocatalyst structure and a hydrous gel exhibits an unexpected air cleaning effect: The mechanism of action such as 3) to 5) can be considered (see FIG. 9B).

1) Deodorization effect by photocatalyst structure regarding airflow A 2) Deodorization effect by water-containing gel that absorbs water to the extent that airflow B retains its form

3) Deodorizing effect by airflow C and photocatalyst structure As shown in FIG. 9B, in addition to airflow A and airflow B described above, airflow C (for example, 0) from water-containing gel container side section 38 to photocatalyst structure side section 37 About 3 to 1.0 m / s) has been observed. The air flow C causes moisture to evaporate from the water-containing gel 32 by the fan 9 so that the water-containing gel container side section 38 becomes high humidity, and a humidity concentration gradient (nonuniformity) is generated between the air flow C and the photocatalyst structure side section 37. This seems to be caused by the movement of air in a direction that alleviates this humidity concentration gradient (non-uniformity). Moist air in the hydrated gel storage container side section 38 and odorous substances trapped in the airflow C flow into the section 37 from the section 38, so that moisture for photocatalysis and contamination trapped in the moisture are collected. Odor substances and the like are efficiently conveyed to the photocatalyst structure side together. Furthermore, since the photocatalyst structure according to the present application is made of a porous sponge-like water-absorbing polymer, the odorous substance and moisture necessary for the photocatalytic action continue to be present in the photocatalyst present in the numerous voids. As a result, it is presumed that the photocatalytic reaction is performed more efficiently and the odorous substance is decomposed more effectively.

4) Effect of Air Flow C ′ As shown in FIG. 9B, an air flow C ′ in which the air in the photocatalyst structure side section 37 flows to the water-containing gel container side section 38 is also observed. The active oxygen species generated by the photocatalyst on the compartment 38 side can be supplied to the water-containing gel container compartment 37 by the air flow C ′, which may increase the deodorizing effect of the air.

5) Other effects In the case of the deodorization experiment of the hydrogel alone in Experiment 23, the gel itself becomes odor even if the air is deodorized to some extent, but the photocatalyst structure 10 and the hydrogel 32 in Experiment 24 are used in combination. When allowed to run, the gel remained odorless. This is also a preferable phenomenon when the adsorbent gel itself is regenerated and reused as described below. This unexpected effect may be due to, for example, reactive oxygen species carried by the airflow C ′.

<< Combination effect of photocatalyst structure and water-containing gel in antibacterial and sterilization >> Experiment 25
An improved air purifier 30 is installed in one corner of an old prefab (2.1m x 5.0m x 2m, volume: 21m ³ ) that has been used for 20 years, and the inner wall plywood before and after continuous operation for 24 hours The presence or absence of bacteria was examined by a method for determining the presence of sancori manufactured by Sun Chemical Co., Ltd. As a result, when the improved air cleaning device 30 was not installed, a positive reaction of general bacteria was confirmed from 3 sheets after 24 hours in an inspection using 5 plywood. When installed, the test after 24 hours of operation was all negative in the test using five plywoods located 3.5 m away from the place where the air purifier was installed. From this, it was found that the improved air cleaning device 30 including the photocatalyst structure 10 and the water-containing gel 32 also has the effect of sterilizing and sterilizing air.

<< Regeneration Method of Hydrous Gel >> Experiment 26, Table 16
The hydrogel 32 can be regenerated as follows and used many times. The water-containing gel 32 used for about one month was forcibly dehydrated and dried in an atmosphere at 50 ° C. and stored for 7 months, and a water-containing gel regeneration experiment was conducted. When such a preserved material was water-absorbed by the method implemented in Experiment 19 with a surface area of 1190 cm ² , a regenerated water-containing gel having a water absorption ratio of 20 times could be obtained. Compared to a water-containing gel obtained by absorbing a new water-absorbing resin, the appearance performance is not distinguishable at all, and the adsorption performance is similar to the following. Actually, when the improved air cleaning device 30 is used for a long period of time, if this hydrated gel has dried, it can be regenerated and used again by absorbing water again.

(Experiment 26)

The above description is merely representative of the principles of the present invention. Many modifications and variations of the present invention are possible in light of the above teachings. While preferred embodiments of the invention have been disclosed, those skilled in the art will recognize that several modifications fall within the scope of the invention. Accordingly, it is to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described. For that reason, the appended claims should be studied to determine the true scope and content of this invention.

This application claims priority based on Japanese Patent Application No. 2011-212696 filed in Japan on September 28, 2011, the entire contents of which are incorporated herein by reference.

The photocatalyst structure and the method for producing the photocatalyst structure according to the present invention can be used in various fields as a structure having a good photocatalytic function and a method for producing the structure. Moreover, the air purification apparatus provided with the photocatalyst structure according to the present invention can be used as an air purification apparatus having good functions such as deodorization and sterilization of air.

DESCRIPTION OF SYMBOLS 9 ... Fan 10 ... Photocatalyst structure 11 ... Photocatalyst layer 11a ... Photocatalyst 11b ... Air gap 12 ... Support substrate 20 ... Air purifier 21 ... Support substrate 22 ...・ Light source (LED)
23 ... Counter substrate 24 ... Column 30 ... Improved air cleaning device 32 ... Hydrous gel 33 ... Hydrous gel storage container 33a ... Inner container 33b ... Outer container 33b1 ... -Hole 35 ... Air intake port 36 ... Air exhaust port 37 ... Water-containing gel container side compartment 38 ... Photocatalyst structure side compartment 40 ... Housing

Claims

It has a sponge-like photocatalyst layer in which many voids are formed,
The photocatalyst layer includes a photocatalyst, a water-absorbing polymer, and a water-soluble binder.
The photocatalyst is titanium oxide, and the water-absorbing polymer is (1) a crosslinked acrylic polymer comprising a monomer selected from acrylic acid or a salt thereof, an acrylate ester and acrylamide, (2 The photocatalyst structure according to claim 1, wherein the photocatalyst structure is at least one member selected from: a) a crosslinked product of isobutylene-maleic anhydride copolymer, and (3) a crosslinked polyoxyethylene.
The photocatalyst structure according to claim 2, wherein the water-absorbing polymer is a crosslinked acrylic polymer comprising a monomer selected from acrylic acid or a salt thereof, an acrylic ester and acrylamide.
The photocatalyst structure according to any one of claims 1 to 3, wherein the water-soluble binder is a polyvinyl alcohol-based or vinyl acetate resin-based binder.
A photocatalyst structure according to any one of claims 1 to 4, a first substrate on which the photocatalyst structure is arranged, a light source, and a second substrate on which the light source is arranged, The photocatalyst structure is disposed so as to face the light source.
Furthermore, the air cleaning apparatus of Claim 5 provided with the water-containing gel which absorbed and swollen.
The air purification apparatus according to claim 6, wherein the water-containing gel absorbs water to such an extent that the gel form can be maintained.
The air purification apparatus according to claim 6 or 7, wherein the hydrated gel is stored in a storage container.
A housing having a first opening for taking in air and a second opening for discharging air; and in the housing, the photocatalyst structure disposed on the first substrate, and the second substrate. A light emitting element that is the light source disposed on the surface of the light emitting element is disposed in parallel to an axis connecting the first opening and the second opening, and the first substrate or the second substrate. The air purifier according to claim 8, wherein the storage container storing the hydrated gel is disposed on at least one of the back surfaces.
The air cleaning device according to claim 8 or 9, wherein the storage container includes an inner container made of a mesh sheet for storing the hydrated gel and an outer container made of a perforated plastic for storing the inner container.
The air cleaner according to claim 10, wherein the outer container has two sets of two upper and lower layers arranged in parallel on the back surface of the first substrate or the second substrate.
The air cleaning apparatus according to claim 11, wherein an upper end of the first or second substrate on a side where the outer container is disposed is lower than an upper end of the two upper containers stacked.
The air purification apparatus according to any one of claims 6 to 12, wherein the water-containing gel absorbs an aqueous solution containing metal ions.
The air purification apparatus according to any one of claims 6 to 13, wherein when the water-containing gel is dried, it can be regenerated and reused by absorbing water.
A method for producing a photocatalyst structure according to any one of claims 1 to 4,
Mixing and stirring the photocatalyst and a water-soluble binder to produce a first mixture;
Mixing the first mixture with a water-absorbing polymer to produce a second mixture;
Forming the second mixture;
Drying the molded second mixture,
A method for producing a photocatalyst structure, comprising:
The photocatalyst is titanium oxide, and the water-absorbing polymer is (1) a crosslinked acrylic polymer comprising a monomer selected from acrylic acid or a salt thereof, an acrylate ester and acrylamide, (2 The method for producing a photocatalyst structure according to claim 15, wherein the photocatalyst structure is at least one member selected from: a crosslinked product of isobutylene-maleic anhydride copolymer and (3) a crosslinked polyoxyethylene.
The method for producing a photocatalyst structure according to claim 15 or 16, wherein the water-soluble binder is a polyvinyl alcohol-based or vinyl acetate resin-based binder.
The method for producing a photocatalyst structure according to any one of claims 15 to 17, wherein the step of mixing the water-absorbing polymer further comprises adding water.