JPH11114330A - Photocatalyst filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photocatalyst filter which decomposes and removes bad odor and harmful substances such as bacteria by the photocatalytic effect of a photoreactive semiconductor and which has high photocatalytic activity, durability and air permeability. SOLUTION: This filter is produced by depositing a functional mixture containing a photoreactive semiconductor, a metal oxide composite thermoplastic polymer emulsion, a film forming inorg. material and an adsorbent on a base body. Moreover, by laminating an electrostatic filter on this photocatalytic filter, a composite filter member having extremely excellent dust-removing and deodorizing performance is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photocatalytic filter, and more particularly to a photocatalytic filter capable of decomposing and removing harmful substances such as bad smells and bacteria by the photocatalytic action of a photoreactive semiconductor, as well as high air permeability and durability. And a photocatalytic filter also having:

[0002]

2. Description of the Related Art Problems of conventional environmental pollution caused by industrially generated odors and harmful chemical substances in factories, and odors caused by wastes in service industries such as restaurants and hotels that discharge a large amount of waste. In addition, with the recent increase in amenity-oriented, the problem of indoor environmental pollution due to odors and harmful chemical substances in general living spaces, for example, indoors and cars, has been increasing, and the need for the removal of these harmful substances has been increasing. It is growing rapidly.

[0003] As a method of removing harmful substances such as odors and harmful chemical substances, porous substances such as activated carbon and zeolite,
A so-called adsorption removal by an adsorbent is common. However, the adsorbent only shows an adsorbing effect on most harmful substances, and when a certain amount of harmful substances is adsorbed, the removal performance is significantly reduced, or harmful substances once adsorbed depending on the ambient temperature and concentration of harmful substances. There is a problem that the substance is detached.

In order to solve such a problem, a method of decomposing and removing harmful substances using a catalyst has been devised.
Various materials having the ability to decompose and remove harmful substances are known, and among them, photoreactive semiconductors represented by titanium oxide have attracted great attention in recent years. For example, Cundall et al. Oil. Chem. Assoc. 1978, 6
No. 1,351 reports that when ultraviolet light is irradiated on titanium oxide, alcohol is decomposed in a mixed system of water and alcohol. Further, JP-A-61-135669
In the publication, it is reported that when a photoreactive semiconductor such as zinc oxide is irradiated with ultraviolet light, a sulfur compound which is a malodorous substance is decomposed. In the decomposition reaction by these photoreactive semiconductors, the photoreactive semiconductor is not consumed as the reaction proceeds, and its decomposition ability is semi-permanent as long as it is exposed to light. Such a photocatalytic reaction is an interfacial reaction, and the more efficiently the photoreactive semiconductor and the decomposition object come into contact, the more efficiently the photocatalytic reaction proceeds. Therefore, as a shape of the photoreactive semiconductor, it is preferable that the photoreactive semiconductor is a powder capable of taking a large specific surface area, but it is difficult to use the photoreactive semiconductor as it is, and it is difficult to use the photoreactive semiconductor on a suitable support using any method. It is necessary to carry and fix.

As a material in which a photoreactive semiconductor is supported and fixed on a support, for example, JP-A-3-75062 discloses a photoreactive semiconductor in which a photoreactive semiconductor such as titanium oxide is supported on a sheet using a latex. A carrier sheet is disclosed. Latex has high film-forming ability, water resistance, and excellent water dispersibility, and thus has advantages such as easy handling.However, when latex is used as a binder to fix a photoreactive semiconductor, photoreactive Latex is decomposed due to the photocatalytic activity of the reactive semiconductor, which causes not only a problem in durability but also a problem that the latex covers the surface of the photoreactive semiconductor and the properties of the photoreactive semiconductor are impaired. Was.

Japanese Patent Application Laid-Open No. 6-315614 discloses a sheet or panel material obtained by mixing and rolling a fluororesin particle such as polytetrafluoroethylene having excellent durability and titanium oxide, or a sheet material. A sheet material or a panel material is disclosed in which an adhesive is applied to a substrate, and then titanium oxide powder is sprinkled and carried. However, in the former sheet materials and panel materials, the use of expensive fluororesin has great economical disadvantages, and the exposure of titanium oxide to the sheet surface becomes insufficient, and it is difficult to sufficiently exert its photocatalytic ability. There is such a problem. on the other hand,
Also in the latter sheet materials and panel materials, it is difficult to firmly fix titanium oxide on the sheet surface, and there is concern about deterioration of the adhesive due to the photocatalytic activity of titanium oxide, and the durability point is uneasy. .

Further, Japanese Patent Application Laid-Open No. 2-187147 discloses a method for fixing titanium oxide using colloidal silica. Colloidal silica is an inorganic substance and has an advantage that not only the durability against the photocatalytic activity of titanium oxide is excellent, but also the properties are not significantly impaired because the film is formed without covering the titanium oxide surface. However, a film made of colloidal silica is insufficient in mechanical strength and water resistance, and there is a sufficient possibility that durability of the film strength is regarded as a problem depending on the environment in which it is used. Even if an attempt is made to impart sufficient strength to the coating, post-treatment such as sintering after the formation of the coating is required, and there is a problem that the range of choice of the material of the support is greatly restricted.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a photocatalytic filter which can decompose and remove harmful substances such as bad smells and bacteria by the photocatalytic action of a photoreactive semiconductor which overcomes the above-mentioned disadvantages. More specifically, it is an object of the present invention to provide a photocatalytic filter having high photocatalytic activity, durability, and air permeability.

[0009]

Means for Solving the Problems The present inventors have studied to solve the above-mentioned problems, and as a result, have reached the following invention.

[0010] 1. The present invention is an invention of a photocatalytic filter, wherein a functional mixture containing a photoreactive semiconductor, a metal oxide composite thermoplastic polymer emulsion, and a film-forming inorganic substance is supported on a substrate.

2. In the above invention 1, the photoreactive semiconductor is 10 to 70% by weight, and the mixture of the metal oxide composite thermoplastic polymer emulsion and the film-forming inorganic substance is 30 to 70% by weight.
90% by weight, and the weight ratio of metal oxide composite thermoplastic polymer emulsion / film-forming inorganic substance is 10/90 to 9
It is an invention of a photocatalyst filter, wherein a functional mixture in the range of 0/10 is supported on a substrate.

3. The present invention provides a photoreactive semiconductor, an adsorbent,
It is an invention of a photocatalyst filter characterized in that a functional mixture containing a metal oxide composite thermoplastic polymer emulsion and a film-forming inorganic substance is supported on a substrate.

4. In the above invention 3, the mixture of the photoreactive semiconductor and the adsorbent is contained in an amount of 20 to 70% by weight, and the mixture of the metal oxide composite thermoplastic polymer emulsion and the film-forming inorganic substance is contained in the amount of 30 to 80% by weight. It is an invention of a photocatalytic filter characterized in that a functional mixture having a composite thermoplastic polymer emulsion / film-forming inorganic substance weight ratio in the range of 10/90 to 90/10 is supported on a substrate.

5. A photocatalyst filter according to any one of the above-described inventions 1 to 4, wherein the functional mixture contains a colorant.

6. In the above inventions 1 to 5, JIS
Air permeability measured according to L 1096 is 100 cm ³ / cm ²
-It is invention of the photocatalyst filter characterized by being more than second.

[7] The invention according to any one of the above 1 to 6, wherein the electrostatic filter is laminated on at least one surface of the photocatalytic filter.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The components relating to the photocatalyst filter of the present invention will be described below in detail.

According to a first aspect of the present invention, there is provided a photoreactive semiconductor,
It is an invention of a photocatalyst filter characterized in that a functional mixture containing a metal oxide composite thermoplastic polymer emulsion and a film-forming inorganic substance is supported on a substrate.

First, the functional mixture will be specifically described below. The functional mixture of the present invention contains a photoreactive semiconductor, a metal oxide composite thermoplastic polymer emulsion, and a film-forming inorganic substance. The functional mixture will be described through specific descriptions of these components constituting the functional mixture.

First, the photoreactive semiconductor will be specifically described below. The photoreactive semiconductor according to the present invention is used for the purpose of decomposing and removing harmful substances such as malodors, bacteria, harmful chemical substances, and pollutants. The photoreactive semiconductor mentioned here is 0.5 to 5 eV, preferably 1 to 3 eV.
A semiconductor that has a bandgap of eV and generates a photocatalytic reaction, and harmful substances are decomposed by holes, OH radicals, and the like generated in the photoreactive semiconductor. As the shape of the photoreactive semiconductor, a particulate shape is preferable, and the specific surface area is 10 to 10.
500 m ² / g particles are appropriately selected and used.

Examples of such a photoreactive semiconductor include those disclosed in JP-A-2-273514, such as zinc oxide, tungsten trioxide, and the like.
Metal oxides such as titanium oxide and cerium oxide are preferable. Among them, titanium oxide is a particularly preferable material in consideration of structural stability, ability as a photoreactive semiconductor, safety in handling, and the like. Examples of the titanium oxide include all titanium oxides or hydroxides called titanium oxide hydroxide, metatitanic acid, orthotitanic acid, and titanium hydroxide, in addition to conventional general-purpose titanium oxide. As a method for producing titanium oxide, a method of hydrolyzing titanyl sulfate, titanium chloride, an organic titanium compound and the like in the presence of seeds for nucleation as necessary (hydrolysis method), A method in which an alkaline agent is added to titanyl sulfate, titanium chloride, an organic titanium compound, and the like to neutralize them while coexisting (neutralization method), and a method in which titanium oxide obtained by hydrolysis and neutralization is calcined (calcination method) ), Etc., and titanium oxide obtained by any of the production methods can be used.

Next, the metal oxide composite thermoplastic polymer emulsion will be specifically described below. The metal oxide composite thermoplastic polymer emulsion according to the present invention,
It was used as a binder for fixing the photoreactive semiconductor to the base material described later, and had a shape in which the surface of the thermoplastic polymer emulsion was coated with a metal oxide, and formed a film. After that, the polymer component and the metal oxide component are separated and have the property of maintaining the sea-island structure.

The term "thermoplastic polymer emulsion" as used herein means a thermoplastic polymer mainly dispersed in water, and the polymer components include acrylic resin, styrene-acryl copolymer, and styrene-butadiene. Copolymer, ethylene-vinyl acetate copolymer, vinyl chloride-vinyl acetate copolymer, ethylene-vinyl acetate-vinyl chloride copolymer,
Examples thereof include polypropylene, polyester, phenoxy resin, phenol resin, and butyral resin.

The metal oxide mentioned here includes colloidal silica and colloidal alumina. Metal oxide composite thermoplastic polymer emulsions, for example, colloidal silica composite thermoplastic polymer emulsions, are disclosed in JP-A-59-71316 and JP-A-60-1.
As disclosed in Japanese Patent No. 27371, a copolymerizable monomer, a monomer having a polymerizable unsaturated double bond and an alkoxysilane group in the molecule, vinyl silane, and colloidal silica are mixed to form a polymer component. In the process of producing by emulsion polymerization, it is obtained by a method of fixing a silica component to the emulsion surface. Other methods include, for example, I
international Symposium on
Polymeric Microspheres P
As described in prints, 1991,181, a method of precipitating and fixing a silica component on the surface of a previously formed emulsion using a water-insoluble hydrolyzable alkoxysilane such as ethyl orthosilicate. Is mentioned.

Next, the film-forming inorganic substance will be specifically described below. The film-forming inorganic substance according to the present invention is used as a binder for fixing the photoreactive semiconductor to a base material described later, similarly to the above-mentioned metal oxide composite thermoplastic polymer emulsion. Specific examples of the film-forming inorganic substance include saponite, hectorite, smectite group such as montmorillonite, vermiculite group,
In addition to kaolinite-serpentine groups such as kaolinite and halloysite, natural clay minerals such as sepiolite, colloidal silica, colloidal alumina, modified products thereof, and synthetic inorganic polymer compounds.

The term “modification in the above-mentioned denatured product” used in the present invention refers to the removal of impurities or specific atomic groups from natural minerals, or the treatment of specific elements in natural mineral constituent elements by an appropriate method to other elements. To extend the properties inherent in natural minerals or to add new properties by exchanging them with other compounds or chemically treating them with other compounds (especially organic compounds), especially to modify the physical properties of the mineral surface. Specific examples of the modified product according to the present invention include Na-montmorillonite obtained by treating Ca-montmorillonite with sodium carbonate or the like in the presence of water and performing ion exchange, a cationic surfactant and / or a nonionic interface. Those treated with an activator may be mentioned.

The synthetic inorganic high molecular compound referred to in the present invention is a compound obtained by substituting a specific element having the same composition with another element in order to obtain a composition equivalent to a natural mineral or to impart new properties. And a compound obtained by reacting two or more kinds of compounds, and examples thereof include a fluoromica in which a hydroxyl group in a structure of a natural mica family is substituted with fluorine, and a synthetic smectite. Typical examples of fluorine mica include fluorine phlogopite [KMg ₃ (AlSi ₃ O ₁₀ ) F ₂ ] and tetrasilicon mica [KMg
_2.5 (Si ₄ O ₁₀ ) F ₂ ], teniolite [KMg ₂ Li (Si ₄ O ₁₀ ) F
₂ ].

An important point in the present invention is that a photoreactive semiconductor is supported and fixed on a substrate by using a metal oxide composite thermoplastic polymer emulsion and a film-forming inorganic substance.

In the case of a film composed of a metal oxide composite thermoplastic polymer emulsion and a photoreactive semiconductor, a metal oxide layer is formed between the aggregate of the photoreactive semiconductor and the polymer component, and Since the contact area with the photoreactive semiconductor is reduced, the degradation of the polymer component due to the oxidative decomposition of the photoreactive semiconductor by the photocatalytic ability is suppressed when compared with a film made of a general thermoplastic polymer emulsion. In addition, not only the durability of the film is greatly improved, but also a decrease in the photocatalytic ability of the photoreactive semiconductor due to the coating of the polymer component can be suppressed. Furthermore, it also has excellent film strength and film water resistance possessed by the polymer component, and can be preferably used as a binder for photoreactive semiconductors.

However, as long as the polymer component is contained in the metal oxide composite thermoplastic polymer emulsion,
Metal oxide composite thermoplastic polymer emulsions are used in applications where the photocatalytic action of photoreactive semiconductors and the deterioration of polymer components due to the action of ultraviolet light cannot be eliminated, and coating durability over an extremely long period is required. Has some problems in terms of durability. In the case of a mixture of a photoreactive semiconductor and a metal oxide composite thermoplastic polymer emulsion, the pigment (here, the photoreactive semiconductor and metal oxide composite thermoplastic polymer emulsion) is slightly inferior in dispersibility and agglomerated. Due to the generation of particles, large aggregated particles fall off from the base material, and the ability of the photoreactive semiconductor cannot be fully drawn out. If the mixed solution is applied to a substrate having high air permeability, that is, a substrate having a large pore diameter, a web-like film is easily formed on the pores of the substrate. There is a problem that air permeability of the material is hindered.

On the other hand, a film composed of a film-forming inorganic substance and a photoreactive semiconductor is extremely excellent in durability against oxidative decomposition and ultraviolet rays due to the photocatalytic action of the photoreactive semiconductor. However, since the film-forming inorganic substance has a large specific surface area and a high hydration power, it significantly swells in water.
It has the property of easily dispersing to form a stable aqueous colloid, and there is a problem that the water resistance of the film is poor. Therefore,
There are some people who are somewhat anxious about using them around water in bathrooms and kitchens, and using them in high humidity environments such as indoors during the rainy season.
In addition, the mechanical strength of the film is small, and there is a problem in the abrasion resistance of the film. Further, in the mixed liquid of the photoreactive semiconductor and the film-forming inorganic substance, the pigment (here, the photoreactive semiconductor and the film-forming inorganic substance) has good dispersibility, and the metal oxide composite thermoplastic polymer described above is good. Although there are few problems such as emulsions, depending on the type of the film-forming inorganic substance, there is also one having extremely strong thixotropic properties, and the viscosity of the mixed liquid of the photoreactive semiconductor and the film-forming inorganic substance becomes extremely high, and is supported on the substrate. There is a problem that becomes difficult.

As described above, the metal oxide composite thermoplastic polymer emulsion and the film-forming inorganic substance each have advantages and disadvantages. When each of them is used alone as a binder for a photoreactive semiconductor substrate, However, there is a good possibility that practical problems will occur. However, by using a mixture of a metal oxide composite thermoplastic polymer emulsion and a film-forming inorganic material, the advantages of the metal oxide composite thermoplastic polymer emulsion and the film-forming inorganic material can be extended and the disadvantages can be greatly improved. Becomes possible. That is, by using a mixture of both, not only the dispersibility of the pigment (here, it refers to a photoreactive semiconductor, a metal oxide composite thermoplastic polymer emulsion, and a film-forming inorganic substance) becomes extremely good, but also the mechanical strength is high. A film having excellent durability and water resistance can be obtained. Therefore, by using the mixture, it is possible to obtain a photocatalyst filter having a high degree of photocatalytic activity, gas permeability, and durability.

In the photocatalytic filter of the present invention, a functional mixture comprising a photoreactive semiconductor, a metal oxide composite thermoplastic polymer emulsion, and a film-forming inorganic substance is uniformly dispersed and supported on a base material. The photocatalytic activity of the conductive semiconductor can be effectively utilized. Therefore, even with a small amount of the photoreactive semiconductor, it is possible to obtain practically sufficient harmful substance removing ability. Of course, the harmful substance removing ability of the photocatalytic filter increases with an increase in the content of the photoreactive semiconductor, so in applications where a higher harmful substance removing ability is required, the content and the like can be increased. Depending on the purpose, appropriately select the content of the photoreactive semiconductor,
What is necessary is just to manufacture a photocatalyst filter having a desired harmful substance removing ability.

As described above, the content of the photoreactive semiconductor in the photocatalytic filter of the present invention may be any, but a particularly preferred content is 1% of the total weight of the functional mixture.
0 to 70% by weight. The effect of the content of the photoreactive semiconductor on the ability of the photocatalytic filter to remove harmful substances is that the content of the photoreactive semiconductor is 10% by weight of the total weight of the functional mixture.
In the region of less than 10% by weight, on the other hand, in the region of 10% by weight or more, the harmful substance removing ability of the photocatalytic filter is gradually improved with an increase in the content of the photoreactive semiconductor,
It is almost saturated at a content of 70% by weight. Therefore, by setting the content of the photoreactive semiconductor to 10% by weight or more of the total weight of the functional mixture, it becomes possible to obtain a photocatalyst filter having extremely good harmful substance removing ability. In the region where the content of the photoreactive semiconductor exceeds 70% by weight, the effect of improving the ability to remove harmful substances with an increase in the amount of the photoreactive semiconductor is small, so that the content of 70% by weight or less may be practically used. .

A film composed of a mixture of a metal oxide composite thermoplastic polymer emulsion and a film-forming inorganic material is excellent in mechanical strength, water resistance and durability. It is possible to fix. Of course, the practical durability of the photocatalytic filter depends on the content of the mixture. Therefore, the content of the mixture is appropriately selected according to the application and purpose, and a photocatalytic filter having a desired durability can be produced. Good. However, as described above, in order to obtain a photocatalyst filter having a high ability to remove harmful substances, the content of the photoreactive semiconductor is preferably 10 to 70% by weight based on the total weight of the functional mixture. The content of the mixture of the oxide composite thermoplastic polymer emulsion and the film-forming inorganic substance is particularly preferably in the range of 30 to 90% by weight based on the total weight of the functional mixture. In addition, although the weight ratio of the metal oxide composite thermoplastic polymer emulsion / the film-forming inorganic material may be any, a series of effects accompanying the mixing of both can be expected, but a particularly preferable weight ratio is 10/90 to 10/90. It is in the range of 90/10. At this weight ratio, the advantages of each of the metal oxide composite thermoplastic polymer emulsion and the film-forming inorganic substance can almost completely compensate for the disadvantages, and maximize the mixing effect of the two. be able to.

The amount of the functional mixture containing the photoreactive semiconductor, the metal oxide composite thermoplastic polymer emulsion, and the film-forming inorganic substance carried on the base material depends on the basis weight of the base material and the purpose. May be appropriately selected depending on the harmful substance removing ability to be used, but about 5 to 200 g / m ² is appropriate.

Next, the substrate is specifically described below. The substrate according to the present invention functions as a support for holding a functional mixture containing a photoreactive semiconductor, a metal oxide composite thermoplastic polymer emulsion, and a film-forming inorganic substance, The substrate is required to have air permeability for transmitting harmful substances and light transmission for activating the photoreactive semiconductor. Examples of the form of such a substrate include a nonwoven fabric or a porous film-like material, but a nonwoven fabric is a particularly preferred substrate because it is easy to control the basis weight, air permeability, and is excellent in workability. is there.

The non-woven fabric is made of polyamide fiber, polyester fiber, polyalkylene paraoxybenzoate fiber, polyurethane fiber, polyvinyl alcohol fiber, polyvinylidene chloride fiber, polyvinyl chloride fiber, polyacrylonitrile fiber, polyolefin fiber. , Synthetic fibers such as phenolic fibers, inorganic fibers such as glass fibers, metal fibers, alumina fibers, activated carbon fibers,
It is produced by various methods using natural fibers such as wood pulp, hemp pulp, and cotton linter pulp, regenerated fibers, or fibers obtained by imparting functions such as hydrophilicity and flame retardancy to these fibers.

The method for producing the nonwoven fabric is not particularly limited, and the web obtained by a dry method, a wet papermaking method, a melt blown method, a spunbond method, etc. may be subjected to a hydroentangling method, a needle punching method, a stitching method, depending on the purpose and application. It can be produced by appropriately combining a physical method such as a bonding method, a bonding method using heat such as a thermal bonding method, and a bonding method using an adhesive such as a resin bond to develop strength.

In carrying the functional mixture containing the photoreactive semiconductor, the metal oxide composite thermoplastic polymer emulsion, and the film-forming inorganic substance on the substrate of the present invention, various blade coaters, roll coaters, air Various coatings such as knife coater, bar coater, rod blade coater, short dwell coater, comma coater, die coater, reverse roll coater, kiss coater, dip coater, curtain coater, extrusion coater, gravure coater, microgravure coater, size press, etc. An apparatus can be used. After the coating, flattening and polishing may be performed using a calendar such as a machine calendar, a TG calendar, a super calendar, or a soft calendar, or molding may be performed using an embossing device.

According to a second aspect of the present invention, there is provided a photoreactive semiconductor,
Adsorbent, metal oxide composite thermoplastic polymer emulsion,
And a functional catalyst comprising a film-forming inorganic material, which is supported on a substrate.

By adding the adsorbent to the functional mixture of the first invention, the harmful substances adsorbed by the adsorbent can be efficiently decomposed and removed by the photoreactive semiconductor. This is probably because the harmful substances adsorbed by the adsorbent are gradually decomposed by the photoreactive semiconductor. In addition, even in a usage environment where the environment temporarily becomes dark, a usage environment where the amount of ultraviolet light is small, or a usage environment where there is a low concentration of a harmful substance whose adsorption process is a rate-determining step, the adsorption action of the adsorbent causes It is possible to maintain a high ability to remove harmful substances. In addition, an adsorbent having not only an adsorption ability but also a catalytic action is one of the preferable materials.

Even more surprisingly, the addition of the adsorbent, presumably due to the interposition of the adsorbent between the photoreactive semiconductor particles, results in a more uniform distribution of the photoreactive semiconductor in the photocatalytic filter. Not only does the photocatalytic reaction by the photoreactive semiconductor proceed more efficiently, but the polymer component of the metal oxide composite thermoplastic polymer emulsion and the contact portion between the substrate and the photoreactive semiconductor are reduced, It has been found that an unexpected effect is obtained that the deterioration of the photocatalytic filter due to the photocatalytic action of the conductive semiconductor is further suppressed.

Specific examples of the adsorbent according to the present invention include activated carbon, activated clay, natural and synthetic zeolites, sepiolite, iron compounds such as iron oxide, zinc oxide, magnesium oxide, silica, silica-zinc oxide composite. , Silica-alumina-zinc oxide composite, composite phyllosilicate,
Alternatively, a mixture thereof may, for example, be mentioned. Although the shape of these adsorbents is not particularly limited, a photoreactive semiconductor, a metal oxide composite thermoplastic polymer emulsion,
In addition, in consideration of mixing with a film-forming inorganic substance, particles are preferable, and the specific surface area is 50 to 2,000 m ² / g.
Can be appropriately selected and used. For example, in the case of activated carbon, those of 500 to 1500 m ² / g are preferable.

In the photocatalytic filter of the present invention, a functional mixture comprising a photoreactive semiconductor, an adsorbent, a metal oxide composite thermoplastic polymer emulsion, and a film-forming inorganic substance is uniformly dispersed and supported on a substrate. In addition, the photocatalytic activity of the photoreactive semiconductor and the adsorbing ability of the adsorbent can be effectively utilized. Therefore, even with a small amount of the photoreactive semiconductor and the adsorbent, it is possible to obtain a practically sufficient ability to remove harmful substances. Of course, the ability of the photocatalytic filter to remove harmful substances increases with the increase in the content of the mixture of the photoreactive semiconductor and the adsorbent. The content of the mixture of the photoreactive semiconductor and the adsorbent may be appropriately selected depending on the use or purpose, such as increasing the amount, and a photocatalytic filter having a desired harmful substance removing ability may be manufactured.

As described above, the content of the mixture of the photoreactive semiconductor and the adsorbent in the photocatalyst filter of the present invention may be any, but a particularly preferred content is 20 to 70% of the total weight of the functional mixture. % By weight. The effect of the content of the mixture of the photoreactive semiconductor and the adsorbent on the ability to remove harmful substances of the photocatalytic filter is particularly remarkable in a region where the content of the mixture is less than 20% by weight of the total weight of the functional mixture, On the other hand, in the region of 20% by weight or more, as the content of the mixture increases, the ability to remove harmful substances of the photocatalytic filter gradually increases, and the content becomes almost saturated at a content of 70% by weight. Therefore, the content of the mixture of the photoreactive semiconductor and the adsorbent is reduced to 20% by weight of the total weight of the functional mixture.
By doing so, it is possible to obtain a photocatalyst filter having extremely good harmful substance removing ability. In a region where the content of the mixture of the photoreactive semiconductor and the adsorbent exceeds 70% by weight, the effect of improving the ability to remove harmful substances with the increase of the mixture is small. Is not a problem.

A film composed of a mixture of a metal oxide composite thermoplastic polymer emulsion and a film-forming inorganic substance has excellent mechanical strength, water resistance and durability, so that a small amount of a mixture of a photoreactive semiconductor and an adsorbent can be used. It is possible to firmly fix to the base material. Of course, the practical durability of the photocatalyst filter depends on the content of the mixture of the metal oxide composite thermoplastic polymer emulsion and the film-forming inorganic substance. Therefore, the content is appropriately selected according to the application and purpose. What is necessary is just to produce a photocatalytic filter having desired durability. However, as described above, in order to obtain a photocatalytic filter having a high ability to remove harmful substances, the content of the mixture of the photoreactive semiconductor and the adsorbent should be 20 to 70% by weight of the total weight of the functional mixture. Therefore, the content of the mixture of the metal oxide composite thermoplastic polymer emulsion and the film-forming inorganic substance is preferably 30 to 80% by weight based on the total weight of the functional mixture. In addition, although the weight ratio of the metal oxide composite thermoplastic polymer emulsion / the film-forming inorganic material may be any, a series of effects accompanying the mixing of both can be expected, but a particularly preferable weight ratio is 10/90 to 10/90. It is in the range of 90/10. In this weight ratio, with the advantages of each of the metal oxide composite thermoplastic polymer emulsion and the film-forming inorganic substance,
Each disadvantage can be almost completely compensated for, and the mixing effect of both can be maximized.

The amount of the functional mixture containing the photoreactive semiconductor, the adsorbent, the metal oxide composite thermoplastic polymer emulsion, and the film-forming inorganic substance loaded on the substrate is determined based on the basis weight of the substrate. It may be appropriately selected according to the intended ability to remove harmful substances, but about 5 to 200 g / m ² is appropriate.

By adding a colorant to the functional mixture of the present invention, the photocatalyst filter of the present invention can be easily colored, and the design can be improved. As colorants, azo dyes, anthraquinone dyes,
Indigo dye, diphenylmethane dye, triphenylmethane dye, phthalocyanine dye, nitro dye, coloring dye such as nitroso dye, azo pigment, phthalocyanine pigment, dioxazine pigment, iron oxide, titanium oxide, coloring pigment such as carbon black, conventionally known, Colorants can be widely used. However, organic dyes and coloring pigments have low durability against oxidative decomposition and ultraviolet rays due to photocatalytic action of the photoreactive semiconductor, and have problems such as fading depending on the application. Therefore, it is preferable to use an inorganic pigment type coloring agent. .

Since the functional mixture of the present invention uses a metal oxide composite thermoplastic polymer emulsion and a film-forming inorganic substance in combination, a pigment (here, a photoreactive semiconductor,
Adsorbent, metal oxide composite thermoplastic polymer emulsion,
The film-forming inorganic substance) has extremely good dispersibility and has an appropriate liquid viscosity, so even when the functional mixture is applied to a highly permeable substrate having a large pore size, the pores are closed. The functional mixture can be uniformly applied to the surface of the base material while maintaining high air permeability without performing. Therefore, if the functional mixture of the present invention is used, JIS L 1
It is easy to produce a highly permeable filter having a permeability of 100 cm ³ / cm ² · sec or more measured according to No.096, and it can be effectively used as a filter for removing harmful substances such as air cleaners and air conditioning systems. It is possible.

It is to be noted that a plurality of photocatalyst filters of the present invention may be used by laminating them, or may be used in combination with other appropriate filter materials or functional sheets, or may be used in combination, depending on the use or purpose. Absent.

As described above, the photocatalytic filter of the present invention has the ability to decompose and remove harmful substances and the ability to decompose and decompose harmful substances, and is also excellent in air permeability, so that it can be effectively used as a filter member even in this form. can do. However, when used as a filter member for an air purifier or an air conditioning system, dust removal performance is often required, and in order to satisfy this requirement, a dust filter is provided on at least one surface of the photocatalyst filter of the present invention. They may be stacked. In this case, it is preferable to use an electrostatic filter having excellent air permeability and also having a high dust removing ability so as not to significantly impair the air permeability of the photocatalytic filter.

The electrostatic filter according to the present invention is a filter that maintains electric polarization semipermanently and applies an electric force to the outside, and captures particles by the electrostatic force. Examples of the charging method include an electro-electret, a heat electret, a radio-electret, a mechano-electret, a photo-electret, a magnet-electret, and the like.The industrially used nonwoven fabric filters are mainly an electro-electret and a heat-electret. In many cases, polypropylene is used as a filter material.

Since the nonwoven fabric is bulky and has three-dimensional voids, it is difficult to obtain a stable charging effect by charging treatment such as corona discharge. However, a film that has been charged by corona discharge or the like is cut into fibers and split into a non-woven fabric, a split fiber electrostatic filter, or a high voltage applied during melt-blow spinning and melt spinning to charge the fibers as a heat electret. The melt-blown non-woven fabric type electrostatic filter and the spun-bonded non-woven fabric type electrostatic filter can obtain a stable polarization charge. Since a melt-blown non-woven fabric type electrostatic filter alone has low mechanical strength, it is generally used by laminating a dry non-woven fabric or a spun bond.

[0055]

EXAMPLES Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these without departing from the gist of the invention.

Preliminary operation 1 Phenoxy resin emulsion (KE-31, manufactured by Toto Kasei)
6. Active ingredient = 48% by weight) To 70 parts by weight of water was added 100 parts by weight of water, heated to 60 ° C. while stirring, and diluted with ethanol, and ethyl orthosilicate (active ingredient = 40% by weight).
180 parts by weight were gradually added dropwise. The heating was further continued to remove ethanol from the system, thereby producing a metal oxide composite thermoplastic polymer emulsion 1 used in Examples.

Preliminary operation 2 Emulsion polymerization solution of copolymerized polyester resin heated to 75 ° C. (manufactured by Toyobo, Vironal, active ingredient = 26% by weight)
To 100 parts by weight, 120 parts by weight of ethyl orthosilicate (active ingredient = 40% by weight) diluted with ethanol was gradually dropped. The heating was further continued to remove ethanol from the system, thereby preparing a metal oxide composite thermoplastic polymer emulsion 2 used in the examples.

Preliminary operation 3 Polyester fiber (fineness 3 denier, fiber length = 38 m)
m) / Polyester fiber (fineness 6 denier, fiber length = 5)
1mm) / rayon fiber (denier 3 denier, fiber length = 5)
A web having a basis weight of 50 g / m ² was prepared by fibrillating and mixing at a weight ratio of 1 mm) = 50/30/20, and strength was imparted by needle punch to prepare a substrate 1 used in the examples.

Preliminary operation 4 Polyester fiber (fineness 3 denier, fiber length = 38 m)
m) / Polyester fiber (fineness 6 denier, fiber length = 5)
1mm) / rayon fiber (denier 3 denier, fiber length = 5)
1mm) = 50/30/20 and fibrillation mixed in a weight ratio of to prepare a basis weight of 35 g / m ² of web, the web 15 g / m ² impregnated with the acrylic emulsion resin in terms of active ingredient, and dried strength To give a substrate 2 having a basis weight of 50 g / m ² used in the examples.

Example 1 As a photoreactive semiconductor, 5% by weight of titanium oxide (P25S6, manufactured by Nippon Aerosil Co., Ltd.), 45% by weight of a metal oxide composite thermoplastic polymer emulsion 1, and a synthetic smectite (film forming inorganic material) were used. The functional mixture containing 50% by weight of Smecton SA (manufactured by Kunimine Industries Co., Ltd.) was impregnated with 30 g / m ² on the substrate 1 to prepare a photocatalyst filter of Example 1.

Example 2 Titanium oxide (manufactured by Nippon Aerosil Co., Ltd., P25S6) was used as a photoreactive semiconductor in an amount of 10% by weight, a metal oxide composite thermoplastic polymer emulsion 1 was used in an amount of 45% by weight. A functional mixture containing 45% by weight of Smecton SA (manufactured by Kunimine Industries Co., Ltd.) was impregnated with 30 g / m ² on the substrate 1 to prepare a photocatalyst filter of Example 2.

Example 3 As a photoreactive semiconductor, 30% by weight of titanium oxide (P25S6, manufactured by Nippon Aerosil Co., Ltd.), 35% by weight of a metal oxide composite thermoplastic polymer emulsion 1 and synthetic smectite (35% by weight) as a film-forming inorganic substance were used. A functional mixture containing 35% by weight of Smecton SA (manufactured by Kunimine Industry Co., Ltd.) was impregnated with 30 g / m ² on the substrate 1 to prepare a photocatalyst filter of Example 3.

Example 4 As a photoreactive semiconductor, 50% by weight of titanium oxide (manufactured by Nippon Aerosil Co., Ltd., P25S6), 3% by weight of a metal oxide composite thermoplastic polymer emulsion 1 and synthetic smectite (3%) as a film-forming inorganic substance were used. A functional mixture comprising 47% by weight of Smecton SA manufactured by Kunimine Industries Co., Ltd. was impregnated with 30 g / m ² on the substrate 1 to prepare a photocatalyst filter of Example 4.

Example 5 As a photoreactive semiconductor, 50% by weight of titanium oxide (P25S6, manufactured by Nippon Aerosil Co., Ltd.), 5% by weight of a metal oxide composite thermoplastic polymer emulsion 1, and synthetic smectite (5%) as a film-forming inorganic substance were used. A functional mixture containing 45% by weight of Smecton SA (manufactured by Kunimine Industries Co., Ltd.) was impregnated with 30 g / m ² on the substrate 1 to prepare a photocatalyst filter of Example 5.

Example 6 As a photoreactive semiconductor, 50% by weight of titanium oxide (P25S6, manufactured by Nippon Aerosil Co., Ltd.), 25% by weight of a metal oxide composite thermoplastic polymer emulsion 1 and synthetic smectite (25% by weight) as a film-forming inorganic substance were used. A functional mixture containing 25% by weight of Smecton SA (manufactured by Kunimine Industries Co., Ltd.) was impregnated with 30 g / m ² on the substrate 1 to prepare a photocatalyst filter of Example 6.

Example 7 As a photoreactive semiconductor, 50% by weight of titanium oxide (manufactured by Nippon Aerosil Co., Ltd., P25S6), 45% by weight of a metal oxide composite thermoplastic polymer emulsion 1 and synthetic smectite (45% by weight) as a film-forming inorganic substance were used. A functional mixture containing 5% by weight of Smecton SA (manufactured by Kunimine Industries Co., Ltd.) was impregnated with 30 g / m ² on the substrate 1 to prepare a photocatalyst filter of Example 7.

Example 8 As a photoreactive semiconductor, 50% by weight of titanium oxide (P25S6, manufactured by Nippon Aerosil Co., Ltd.), 47% by weight of a metal oxide composite thermoplastic polymer emulsion 1 and synthetic smectite (47%) as a film-forming inorganic substance were used. A functional mixture containing 3% by weight of Smecton SA (manufactured by Kunimine Industries Co., Ltd.) was impregnated with 30 g / m ² on the substrate 1 to prepare a photocatalyst filter of Example 8.

Example 9 As a photoreactive semiconductor, 70% by weight of titanium oxide (manufactured by Nippon Aerosil Co., Ltd., P25S6), 15% by weight of a metal oxide composite thermoplastic polymer emulsion 1 and synthetic smectite as a film-forming inorganic substance were used. A functional mixture containing 15% by weight of Smecton SA (manufactured by Kunimine Industries Co., Ltd.) was impregnated with 30 g / m ² on the substrate 1 to prepare a photocatalyst filter of Example 9.

Example 10 As a photoreactive semiconductor, 80% by weight of titanium oxide (P25S6 manufactured by Nippon Aerosil Co., Ltd.), 10% by weight of a metal oxide composite thermoplastic polymer emulsion 1, and synthetic smectite (10% by weight) as a film-forming inorganic substance were used. A functional mixture containing 10% by weight of Smecton SA (manufactured by Kunimine Industries Co., Ltd.) was impregnated with 30 g / m ² on the substrate 1 to prepare a photocatalyst filter of Example 10.

Example 11 5% by weight of titanium oxide (P25S6, manufactured by Nippon Aerosil Co., Ltd.) as a photoreactive semiconductor, 5% by weight of activated carbon (Kuraray Chemical, PW-W5, manufactured by Kuraray Chemical) as an adsorbent, and metal oxide 45% by weight of composite thermoplastic polymer emulsion 2 and 45% by weight of synthetic hectorite (Laponite RD, manufactured by Nippon Silica Kogyo KK) as a film-forming inorganic substance
The contained functional mixture was applied to the substrate 2 by impregnation at 30 g / m ² to produce a photocatalyst filter of Example 11.

Example 12 10% by weight of titanium oxide (P25S6, manufactured by Nippon Aerosil) as a photoreactive semiconductor, 10% by weight of composite phyllosilicate (Mizukanite AP, manufactured by Mizusawa Chemical Industries) as an adsorbent, and metal oxide Hectorite (Laponite RD, manufactured by Nippon Silica Kogyo Co., Ltd.) was 40% by weight of the composite thermoplastic polymer emulsion 2 and 40% by weight as a film-forming inorganic substance.
30g functional mixture comprising by weight% to the substrate 2 / m ²
The photocatalyst filter of Example 12 was produced by impregnation coating.

Example 13 25% by weight of titanium oxide (P25S6, manufactured by Nippon Aerosil Co., Ltd.) as a photoreactive semiconductor and 25% of activated carbon (Kuraray Coal, PW-W5, manufactured by Kuraray Chemical) as an adsorbent.
Wt%, metal oxide composite thermoplastic polymer emulsion 2
3% by weight, and 47% by weight of synthetic hectorite (Laponite RD, manufactured by Nippon Silica Kogyo KK) as a film-forming inorganic substance.
The functional mixture contained was impregnated with 30 g / m ² on the substrate 2 to prepare a photocatalyst filter of Example 13.

Example 14 25% by weight of titanium oxide (P25S6, manufactured by Nippon Aerosil) as a photoreactive semiconductor, 25% by weight of composite phyllosilicate (Mizukanite AP, manufactured by Mizusawa Chemical Industries) as an adsorbent, metal oxide 30 g / m 2 of a functional mixture containing 5 wt% of a composite thermoplastic polymer emulsion 2 and 45 wt% of a synthetic hectorite (Laponite RD, manufactured by Nippon Silica Kogyo KK) as a film-forming inorganic substance. ^Two impregnation coatings were performed to produce a photocatalyst filter of Example 14.

Example 15 25% by weight of titanium oxide (Nippon Aerosil, P25S6) as a photoreactive semiconductor and 25% of activated carbon (Kuraray Chemical, Kuraray Coal PW-W5) as an adsorbent
Wt%, metal oxide composite thermoplastic polymer emulsion 2
And a functional mixture containing 25% by weight of synthetic hectorite (Laponite RD, manufactured by Nippon Silica Kogyo Co., Ltd.) as a film-forming inorganic substance was impregnated with 30 g / m ² onto the base material 2 to form a coating. Fifteen photocatalytic filters were produced.

Example 16 25% by weight of titanium oxide (P25S6, manufactured by Nippon Aerosil) as a photoreactive semiconductor, 25% by weight of composite phyllosilicate (Mizukanite AP, manufactured by Mizusawa Chemical Industries) as an adsorbent, and metal oxide 30 g / m 2 of a functional mixture containing 45% by weight of the composite thermoplastic polymer emulsion 2 and 5% by weight of a synthetic hectorite (Laponite RD, manufactured by Nippon Silica Kogyo KK) as a film-forming inorganic substance. ^Two impregnation coatings were performed to produce a photocatalyst filter of Example 16.

Example 17 25% by weight of titanium oxide (P25S6, manufactured by Nippon Aerosil Co., Ltd.) as a photoreactive semiconductor and 25% of activated carbon (Kuraray Coal, PW-W5, manufactured by Kuraray Chemicals) as an adsorbent.
Wt%, metal oxide composite thermoplastic polymer emulsion 2
47% by weight, and 3% by weight of synthetic hectorite (Laponite RD, manufactured by Nippon Silica Kogyo KK) as a film-forming inorganic substance.
The functional mixture contained was applied to the substrate 2 by impregnation at 30 g / m ² to produce a photocatalyst filter of Example 17.

Example 18 35% by weight of titanium oxide (P25S6, manufactured by Nippon Aerosil) as a photoreactive semiconductor, 35% by weight of composite phyllosilicate (Mizukanite AP, manufactured by Mizusawa Chemical Industries) as an adsorbent, metal oxide Hectorite (Laponite RD, manufactured by Nippon Silica Kogyo Co., Ltd.) as 15% by weight of the composite thermoplastic polymer emulsion 2
30g functional mixture comprising by weight% to the substrate 2 / m ²
The photocatalyst filter of Example 18 was produced by impregnation coating.

Example 19 As a photoreactive semiconductor, 40% by weight of titanium oxide (manufactured by Nippon Aerosil, P25S6), and as an adsorbent, activated carbon (manufactured by Kuraray Chemical, Kuraray Coal PW-W5) were used.
Wt%, metal oxide composite thermoplastic polymer emulsion 2
And a functional mixture containing 10% by weight of a synthetic hectorite (Laponite RD, manufactured by Nippon Silica Kogyo Co., Ltd.) as a film-forming inorganic material was impregnated with 30 g / m ² onto the base material 2 to form a coating. Nineteen photocatalytic filters were produced.

Example 20 A photocatalyst filter of Example 20 was prepared in the same manner as in Example 6, except that the amount of the functional mixture supported on the substrate was 10 g / m ² .

Example 21 A photocatalyst filter of Example 21 was produced in the same manner as in Example 6, except that the amount of the functional mixture supported on the substrate was 50 g / m ² .

Example 22 A photocatalyst filter of Example 22 was prepared in the same manner as in Example 15, except that the amount of the functional mixture supported on the substrate was 10 g / m ² .

Example 23 A photocatalyst filter of Example 23 was produced in the same manner as in Example 15, except that the amount of the functional mixture supported on the substrate was 50 g / m ² .

Example 24 As a coloring agent, a coloring pigment (EMB, manufactured by Toyo Ink Manufacturing Co., Ltd.)
row R) is 0.1% by weight of the total weight of the functional mixture
Example 2 was prepared in the same manner as in Example 6 except that it was added.
The photocatalyst filter of No. 4 was produced.

Example 25 As a coloring agent, a color pigment (manufactured by Toyo Ink Manufacturing Co., Ltd., EMC
obalt Blue) to the total weight of the functional mixture at 0.
A photocatalyst filter of Example 25 was prepared in the same manner as in Example 15, except that 1% by weight was added.

Example 26 An electrostatic filter (Shintex EL / EB2, manufactured by Mitsui Petrochemical Industries, Ltd.) was applied to one surface of the photocatalytic filter of Example 6.
0N) to form a composite filter member of Example 26.

Example 27 An electrostatic filter (Shintex EL / EB, manufactured by Mitsui Petrochemical Industries, Ltd.) was applied to one surface of the photocatalytic filter of Example 15.
20N) to form a composite filter member of Example 27.

Comparative Example 1 As a photoreactive semiconductor, a functional mixture containing 10% by weight of titanium oxide (P25S6 manufactured by Nippon Aerosil Co., Ltd.) and 90% by weight of a metal oxide composite thermoplastic polymer emulsion 1 was used as a base material. The photocatalyst filter of Comparative Example 1 was produced by impregnating and coating 30 g / m ^{2 on} No. 1.

Comparative Example 2 Titanium oxide (P25S6, manufactured by Nippon Aerosil Co., Ltd.) was used as a photoreactive semiconductor at 10% by weight, and as a film-forming inorganic substance, synthetic smectite (manufactured by Kunimine Industries, Smecton S) was used.
A functional mixture containing 90% by weight of A) was applied to the substrate 1 by impregnation at 30 g / m ² to prepare a photocatalyst filter of Comparative Example 2.

Comparative Example 3 As a photoreactive semiconductor, a functional mixture containing 40% by weight of titanium oxide (P25S6 manufactured by Nippon Aerosil) and 60% by weight of a metal oxide composite thermoplastic polymer emulsion 1 was used as a base material. The photocatalyst filter of Comparative Example 3 was produced by impregnating and coating 30 g / m ^{2 on} 1.

Comparative Example 4 Titanium oxide (P25S6, manufactured by Nippon Aerosil Co., Ltd.) as a photoreactive semiconductor was 40% by weight, and synthetic smectite (Smecton S, manufactured by Kunimine Industries) was used as a film-forming inorganic substance.
A functional mixture containing 60% by weight of A) was coated on the substrate 1 by impregnation at 30 g / m ² to prepare a photocatalyst filter of Comparative Example 4.

Comparative Example 5 As a photoreactive semiconductor, a functional mixture containing 70% by weight of titanium oxide (P25S6 manufactured by Nippon Aerosil Co., Ltd.) and 30% by weight of a metal oxide composite thermoplastic polymer emulsion 1 was used as a base material. 1 was impregnated with 30 g / m ² to produce a photocatalyst filter of Comparative Example 5.

Comparative Example 6 70% by weight of titanium oxide (P25S6, manufactured by Nippon Aerosil) as a photoreactive semiconductor, and synthetic smectite (Smecton S, manufactured by Kunimine Industries) as a film-forming inorganic substance.
The functional mixture containing 30% by weight of A) was applied to the substrate 1 by impregnation at 30 g / m ² to prepare a photocatalyst filter of Comparative Example 6.

Comparative Example 7 Titanium oxide (P25S6, manufactured by Nippon Aerosil) was used as a photoreactive semiconductor at 10% by weight, and activated carbon (Kuraray Chemical, PW-W5, manufactured by Kuraray Chemical) was used as an adsorbent.
Wt%, metal oxide composite thermoplastic polymer emulsion 2
Of a functional mixture containing 80% by weight of
g / m ^{2 was} impregnated to form a photocatalyst filter of Comparative Example 7.

Comparative Example 8 10% by weight of titanium oxide (P25S6, manufactured by Nippon Aerosil) as a photoreactive semiconductor, 10% by weight of composite phyllosilicate (Mizukanite AP, manufactured by Mizusawa Chemical Industries) as an adsorbent, and film formation 80% by weight of synthetic hectorite (Laponite RD, manufactured by Nippon Silica Kogyo Co., Ltd.)
The functional mixture contained was impregnated and coated on the substrate 2 at 30 g / m ² to produce a photocatalyst filter of Comparative Example 8.

Comparative Example 9 Titanium oxide (P25S6, manufactured by Nippon Aerosil Co., Ltd.) was used as a photoreactive semiconductor in an amount of 20% by weight, and activated carbon (manufactured by Kuraray Chemical, Kuraray Coal PW-W5) was used as an adsorbent.
Wt%, metal oxide composite thermoplastic polymer emulsion 2
Of a functional mixture containing 60% by weight of
g / m ^{2 was} impregnated to form a photocatalyst filter of Comparative Example 9.

Comparative Example 10 20% by weight of titanium oxide (manufactured by Nippon Aerosil Co., Ltd., P25S6) as a photoreactive semiconductor, and 20% by weight of composite phyllosilicate (Mizukanite AP, manufactured by Mizusawa Chemical Industries) as an adsorbent. 60% by weight of synthetic hectorite (Laponite RD, manufactured by Nippon Silica Kogyo Co., Ltd.)
The functional mixture contained was impregnated and coated at 30 g / m ² on the substrate 2 to prepare a photocatalyst filter of Comparative Example 10.

Comparative Example 11 35% by weight of titanium oxide (P25S6, manufactured by Nippon Aerosil) as a photoreactive semiconductor, and 35% of activated carbon (Kuraray Coal, PW-W5, manufactured by Kuraray Chemical) as an adsorbent.
Wt%, metal oxide composite thermoplastic polymer emulsion 2
A functional mixture containing 30% by weight of
g / m ^{2 was} impregnated and applied to prepare a photocatalyst filter of Comparative Example 11.

Comparative Example 12 35% by weight of titanium oxide (manufactured by Nippon Aerosil Co., Ltd., P25S6) as a photoreactive semiconductor, 35% by weight of composite phyllosilicate (Mizukanite AP, manufactured by Mizusawa Chemical Industries) as an adsorbent, and film formation 30% by weight of synthetic hectorite (Laponite RD, manufactured by Nippon Silica Co., Ltd.)
The functional mixture contained was impregnated with 30 g / m ² on the substrate 2 to produce a photocatalyst filter of Comparative Example 12.

The photocatalytic filter and the composite filter member obtained in the above examples were tested by the following methods to evaluate the performance.

[Deodorizing performance A] The photocatalytic filter was set to 10c
It was cut into a size of mx 10 cm, and left at the bottom of a 5.6 liter closed container equipped with a 6 W black lamp so that the distance from the black lamp was 2 cm. After 100 ppm of acetaldehyde was injected into the container and left for 20 minutes without turning on the black lamp, the acetaldehyde concentration (ppm) in the container was measured by gas chromatography.

[Deodorizing performance B] After the test of [Deodorizing performance A] is completed, a 6 W black lamp is turned on to irradiate ultraviolet rays.
The acetaldehyde concentration (ppm) in the container 20 minutes after the ultraviolet irradiation was measured by gas chromatography.

[Air permeability] Air permeability of the photocatalytic filter (cm
³ / cm ² · sec) was measured using a Frazier-type tester according to JIS L 1096.

[Scratch Resistance] The surface of the photocatalyst filter was rubbed with a cotton swab to observe the scratch resistance. When the drop of the functional mixture from the photocatalyst filter is observed with less than 50 reciprocations, the abrasion resistance is "poor", and when the number of reciprocations of 50 to 199 repetitions, the drop of the functional mixture from the photocatalyst filter is reduced. When observed, the abrasion resistance was “normal”, and when the functional mixture dropped off from the photocatalyst filter was observed after 200-500 reciprocations, the abrasion resistance was “good”, more than 500 reciprocations. The case where the falling off of the functional mixture from the photocatalyst filter was observed by the number of times of rubbing, or the case where no falling off of the functional mixture was observed was judged as “excellent” in the rub resistance.

[Water Resistance] After the photocatalyst filter was sufficiently immersed in water, the water resistance was observed by rubbing the surface of the photocatalyst filter with a cotton swab. The abrasion resistance after immersion in water was evaluated in the same manner as in [Abrasion resistance] and used as an index of water resistance.

[Durability] A 20 W black lamp was installed so that the distance from the photocatalytic filter was 2 cm.
The black lamp was turned on and irradiated with ultraviolet rays for 1000 hours. The abrasion resistance of the photocatalyst filter after ultraviolet irradiation was evaluated by the same method as in [Abrasion resistance], and used as an index of durability.

[Filter Performance] The filter performance of the composite filter members of Examples 26 and 27 was examined. First, the composite filter members of Example 26 and Example 27 were processed into a pleated shape to produce a filter unit (the amount of the composite filter member used: about 1 m ² ).
The filter unit and 30W sirocco fan, 6W
And two black lamps were combined to produce an experimental air purifier. The filter performance of the composite filter members of Example 26 and Example 27 was evaluated using the acetaldehyde removal performance and the tobacco smoke particle removal performance of the air purifier as indices. First, an air purifier was allowed to stand still in a 1 m ³ stainless steel sealed container, 10 ppm of acetaldehyde was injected into the container, and the air purifier was operated for 30 minutes. Then, the acetaldehyde concentration (C: ppm) in the container was measured. The removal rate of acetaldehyde (%: 100 × (10−C) / 10) was determined by gas chromatography. next,
After injecting five mild seven cigarette smokes into the container, the air purifier was operated for 30 minutes. Airborne dust amount in the container immediately after tobacco smoke injection ^{(A: mg / m 3)} , airborne dust amount in the container after air cleaner operation (B: mg / m ³⁾ was measured with a dust meter, cigarette smoke particles Removal rate (%: 100 × (AB))
/ A).

Tables 1 to 6 show the results of the above test items.

[0108]

[Table 1]

[0109]

[Table 2]

[0110]

[Table 3]

[0111]

[Table 4]

[0112]

[Table 5]

[0113]

[Table 6]

The photocatalyst filters of Examples 1 to 25 showed good results for all evaluation items. In particular, Examples 11 to 19, 2 in which the adsorbent was mixed in the functional mixture.
It was found that the photocatalyst filters 2, 23, and 25 not only have a certain degree of deodorizing performance even when not irradiated with ultraviolet light, but also show excellent deodorizing performance due to a synergistic effect with the photoreactive semiconductor when irradiated with ultraviolet light. In addition, the photocatalyst filters of Examples 24 and 25 in which the coloring agent was mixed in the functional mixture were excellent in decorative feeling. Furthermore, it was found that the composite filter members of Examples 26 and 27 in which the electrostatic filters were laminated had excellent dust removing and deodorizing performance, and effectively acted as filter members for air cleaners, air conditioning systems, and the like.

Comparative Examples 1, 3, 5, 7, and 7 each using a metal oxide composite thermoplastic polymer emulsion alone as a binder
In the photocatalyst filters of Nos. 9 and 11, not only did the deodorizing performance degraded and the falling off of the functional mixture seemed to be caused by the agglomerated particles of the functional mixture, but also the The web-like film was easily applied to the material gap, and the air permeability was poor. On the other hand, Comparative Examples 2 and 4, in which a film-forming inorganic substance was used alone as a binder,
The photocatalyst filters 6, 8, 10 and 12 were excellent in deodorizing performance and air permeability, but lacked mechanical strength and water resistance of the film, and were inferior in practical durability.

When the electrostatic filters were not laminated, the dust-removing performance was insufficient, and the filter did not function effectively as a dust-removing / deodorizing filter member.

[0117]

The photocatalyst filter of the present invention, in which a functional mixture containing a photoreactive semiconductor, a metal oxide composite thermoplastic polymer emulsion, and a film-forming inorganic substance is supported on a substrate, has not only a deodorizing performance but also a deodorizing performance. , Breathability, abrasion resistance,
Excellent effects were exhibited in various characteristics required as a photocatalytic filter, such as water resistance and durability. Further, in the present invention, particularly excellent effects were exhibited by setting these components to specific component ratios. In addition, it was found that the photocatalyst filter obtained by adding an adsorbent as a component to the above configuration further improved the deodorizing performance. Furthermore, the composite filter member obtained by laminating the electrostatic filter on the photocatalyst filter having the above configuration has extremely excellent dust removing and deodorizing performance, for example, acetaldehyde removing performance and tobacco smoke particle removing performance. .

Claims (7)

[Claims] 1. A photocatalyst filter comprising a substrate on which a functional mixture containing a photoreactive semiconductor, a metal oxide composite thermoplastic polymer emulsion, and a film-forming inorganic substance is supported. 2. A metal oxide composite thermoplastic polymer emulsion containing 10 to 70% by weight of a photoreactive semiconductor and 30 to 90% by weight of a mixture of a metal oxide composite thermoplastic polymer emulsion and a film-forming inorganic substance. 2. A functional mixture having a weight ratio of a / film-forming inorganic substance in the range of 10/90 to 90/10 supported on a substrate.
The photocatalyst filter according to the above. 3. A photocatalytic filter, wherein a functional mixture comprising a photoreactive semiconductor, an adsorbent, a metal oxide composite thermoplastic polymer emulsion, and a film-forming inorganic substance is supported on a substrate. 4. A mixture of a photoreactive semiconductor and an adsorbent is 20 to 70% by weight, and a mixture of a metal oxide composite thermoplastic polymer emulsion and a film-forming inorganic substance is 30 to 80%.
% By weight, and the weight ratio of the metal oxide composite thermoplastic polymer emulsion / the film-forming inorganic substance is from 10/90 to 90 /
4. The photocatalytic filter according to claim 3, wherein the functional mixture in the range of 10 is supported on the substrate. 5. The photocatalytic filter according to claim 1, wherein a colorant is contained in the functional mixture. 6. The photocatalyst filter according to claim 1, wherein the air permeability measured according to JIS L 1096 is 100 cm ³ / cm ² · second or more. 7. A composite filter member comprising an electrostatic filter laminated on at least one surface of the photocatalytic filter according to claim 1.