Photocatalyst filter

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to a photocatalytic filter, and more particularly to a photocatalytic filter capable of decomposing and removing harmful substances such as malodors and bacteria by the photocatalytic action of a photoreactive semiconductor, and also having a high degree of air permeability and durability.

【0002】

[Conventional technology]

In addition to the conventional problems of environmental pollution caused by industrially generated foul odors and harmful chemical substances in factories, and foul odors caused by waste in service industries such as restaurants and hotels that discharge a large amount of waste, recently With the growing preference for amenity, the problem of indoor environmental pollution caused by bad odors in general living spaces, such as indoors and automobiles, and harmful chemical substances has been highlighted, and the need for removal of these harmful substances is rapidly increasing. ..

【0003】

As a method for removing harmful substances such as malodors and harmful chemical substances, it is common to remove by adsorption with a porous substance such as activated carbon or zeolite, a so-called adsorbent. However, the adsorbent shows only an adsorbing effect on most harmful substances, and when a certain amount of harmful substances is adsorbed, the removal performance is significantly reduced, or the harmful substances once adsorbed depending on the ambient temperature and the concentration of the harmful substances. There was a problem that the substance was separated.

【0004】

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, but among them, photoreactive semiconductors represented by titanium oxide have attracted a great deal of attention in recent years. For example, Cundall et al. Reported in J.Oil.Chem.Assoc.1978,61,351 that when titanium oxide is irradiated with ultraviolet rays, alcohol is decomposed in a mixed system of water and alcohol. Further, Japanese Patent Application Laid-Open No. 61-135669 reports 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 progresses, 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 contact opportunities between the photoreactive semiconductor and the decomposition target, the more efficiently the photocatalytic reaction proceeds. Therefore, the shape of the photoreactive semiconductor is preferably a powder having a large specific surface area, but it is difficult to use the photoreactive semiconductor as a powder as it is, and some method is used to obtain an appropriate support. It is necessary to support and fix.

【0005】

As a material on which a photoreactive semiconductor is supported and fixed on a support, for example, in Japanese Patent Application Laid-Open No. 3-75062, a photoreactive semiconductor-supported sheet in which a photoreactive semiconductor such as titanium oxide is supported on a sheet using latex is used. It is disclosed. Latex has advantages such as high film-forming ability, water resistance, and excellent water dispersibility, so it is easy to handle. However, when a photoreactive semiconductor is fixed using latex as a binder, it undergoes a photoreaction. Latex is decomposed by the photocatalytic activity of the sex semiconductor, which not only causes a problem in terms of durability, but also has a problem that the latex coats the surface of the photoreactive semiconductor and the characteristics of the photoreactive semiconductor are impaired. It was.

【0006】

Further, in Japanese Patent Application Laid-Open No. 6-315614, a sheet material or a panel material obtained by mixing and rolling titanium oxide with fluororesin particles such as polytetrafluoroethylene having excellent durability, or an adhesive on the sheet. Is disclosed, and a sheet material or a panel material on which titanium oxide powder is sprinkled and supported after coating is disclosed. However, in the former sheet material and panel material, the use of expensive fluororesin has a large economic demerit, and the exposure of titanium oxide to the sheet surface becomes insufficient, and it is difficult to fully exert its photocatalytic ability. There are problems such as. On the other hand, even in the latter sheet material and panel material, 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. Will be done.

【0007】

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

【0008】

[Problems to be Solved by the Invention]

An object of the present invention is to provide a photocatalytic filter capable of decomposing and removing harmful substances such as malodors and bacteria by the photocatalytic action of a photoreactive semiconductor that overcomes the above-mentioned drawbacks. It is an object of the present invention to provide a photocatalytic filter having both durability and breathability.

【0009】

[Means for solving problems]

As a result of studies to solve the above problems, the present inventors have reached the following inventions.

【0010】

1. The present invention is an invention of a photocatalytic filter characterized in that 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. is there.

【0011】

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

【0012】

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

【0013】

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

【0014】

5. In the inventions 1 to 4 above, it is an invention of a photocatalytic filter characterized by containing a colorant in a functional mixture.

【0015】

6. In the inventions 1 to 5 above, the air permeability measured according to JIS L 1096 is 100 cm.³/cm²-It is an invention of a photocatalytic filter characterized by being seconds or more.

【0016】

7. In the inventions 1 to 6 above, the invention is a composite filter member characterized in that an electrostatic filter is laminated on at least one surface of the photocatalytic filter.

【0017】

BEST MODE FOR CARRYING OUT THE INVENTION

The components related to the photocatalytic filter of the present invention will be described in detail below.

【0018】

The first invention of the present invention is a photocatalytic filter characterized in that 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. Is the invention of.

【0019】

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

【0020】

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 referred to here is a semiconductor that causes a photocatalytic reaction having a prohibited bandwidth of 0.5 to 5 eV, preferably 1 to 3 eV, and is a harmful substance due to holes, OH radicals, etc. generated in the photoreactive semiconductor. Is disassembled. The shape of the photoreactive semiconductor is preferably particulate, with a specific surface area of 10 to 500 m.²Select and use particles of / g as appropriate.

【0021】

Examples of such photoreactive semiconductors include those disclosed in Japanese Patent Application Laid-Open No. 2-273514, and metal oxides such as zinc oxide, tungsten trioxide, titanium oxide, and cerium oxide are preferable. Among these, titanium oxide is a particularly preferable material in consideration of structural stability, ability as a photoreactive semiconductor, safety in handling, and the like. The titanium oxide includes all titanium oxides or hydroxides called titanium hydroxide, metatitanium acid, orthotitanic acid, and titanium hydroxide, in addition to the conventional general-purpose titanium oxide. As a method for producing titanium oxide, a method of hydrolyzing titanyl sulfate, titanium chloride, an organic titanium compound, etc. in the presence of nucleating seeds as needed (hydrolysis method), and if necessary, nucleating seeds. A method of adding an alkaline agent to titanyl sulfate, titanium chloride, an organic titanium compound, etc. to neutralize them while coexisting (neutralization method), and a method of firing titanium oxide obtained by hydrolysis and neutralization methods (firing method). ), Etc., and titanium oxide obtained by any manufacturing method can be used.

【0022】

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 is used as a binder for fixing a photoreactive semiconductor to a substrate described later, and metal-oxidizes the surface of the thermoplastic polymer emulsion. It has a shape covered with an object, and has the property of maintaining the sea-island structure by separating the polymer component and the metal oxide component even after the film is formed.

【0023】

The thermoplastic polymer emulsion referred to here is mainly a thermoplastic polymer dispersed in water, and the polymer components include an acrylic resin, a styrene-acrylic copolymer, and a styrene-butadiene copolymer. , Ethylene-vinyl acetate copolymer, vinyl chloride-vinyl acetate copolymer, ethylene-vinyl acetate-vinyl chloride copolymer, polypropylene, polyester, phenoxy resin, phenol resin, butyral resin and the like.

【0024】

Further, examples of the metal oxide referred to here include colloidal silica and colloidal alumina. The metal oxide composite thermoplastic polymer emulsion, for example, colloidal silica composite thermoplastic polymer emulsion is copolymerizable as disclosed in JP-A-59-71316 and JP-A-60-127371. In the process of mixing a monomer, a monomer having a polymerizable unsaturated double bond and an alkoxysilane group in the molecule, vinylsilane, and colloidal silica, and emulsion-polymerizing the polymer component, the silica component is formed on the emulsion surface. Obtained by the method of fixing to. As another method, as described in, for example, International Symposium on Polymeric Microspheres Prints, 1991, 181 is preformed using a hydrolyzable alkoxysilane that is incompatible with water, such as ethyl orthosilicate. Examples thereof include a method of precipitating and fixing a silica component on the surface of an emulsion.

【0025】

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 a photoreactive semiconductor to a substrate described later, like the above-mentioned metal oxide composite thermoplastic polymer emulsion. Specific examples of film-forming inorganic substances include smectites such as saponite, hectorite, and montmorillonite, kaolinites such as vermiculite, kaolinite, and haloysite-serpentine subgroups, natural clay minerals such as sepiolite, colloidal silica, and colloidal. Examples include alumina and modified products thereof and synthetic inorganic polymer compounds.

【0026】

The modification in the above-mentioned modified product referred to in the present invention means removing impurities and specific atomic groups from natural minerals, or treating specific elements in natural mineral constituent elements by an appropriate method and exchanging them with other elements. Or, by chemically treating with another compound (especially an organic compound) to modify the physical properties of the mineral surface in particular, the properties peculiar to the original natural mineral can be extended or new properties can be imparted. Specific examples of the modified compound referred to in the present invention include Na-monmorillonite obtained by treating Ca-monmorylonite with sodium carbonate or the like in the presence of water and performing ion exchange, or a cationic surfactant and / or a nonionic surfactant. Examples include processed ones.

【0027】

Further, the synthetic inorganic polymer compound referred to in the present invention is a compound in which a specific element having the same composition is replaced with another element in order to obtain a composition equivalent to that of a natural mineral or to impart new characteristics, and there are two types. Examples of the compound obtained by reacting the above compounds include fluorine mica in which a hydroxyl group in the structure of a natural mica group is replaced with fluorine, and synthetic smectite. As a typical example of fluorine mica, fluorine phlogopite [KMg₃(AlSi₃O₁₀) F₂], Fluorine tetrasilicon mica [KMg_2.5(Si₄O₁₀) F₂], Teniolite [KMg₂Li (Si₄O₁₀) F₂] And so on.

【0028】

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

【0029】

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 aggregated portion of the photoreactive semiconductor and the polymer component, and the polymer component and the photoreactive component are photoreactive. Since the contact area with the semiconductor is reduced, deterioration of the polymer component due to oxidative decomposition due to the photocatalytic activity of the photoreactive polymer is suppressed as compared with the film made of a general thermoplastic polymer emulsion, and the film is made of Not only is the durability significantly improved, but it is also possible to suppress a decrease in the photocatalytic activity of the photoreactive semiconductor due to coating with a polymer component. Furthermore, it also has excellent film strength and film water resistance of the polymer component, and can be preferably used as a binder for photoreactive semiconductors.

【0030】

However, as long as the polymer component is contained in the metal oxide composite thermoplastic polymer emulsion, it is not possible to eliminate the deterioration of the polymer component due to the photocatalytic action of the photoreactive semiconductor and the action of ultraviolet rays, and it is extremely difficult. In applications where long-term film durability is required, the film of the metal oxide composite thermoplastic polymer emulsion has some problems in terms of durability. Further, in the case of a mixed solution of a photoreactive semiconductor and a metal oxide composite thermoplastic polymer emulsion, the pigment (here, the photoreactive semiconductor and the metal oxide composite thermoplastic polymer emulsion) is slightly inferior in dispersibility and aggregates. Due to the generation of particles, coarse agglomerated particles fall off from the base material, and the ability of the photoreactive semiconductor cannot be fully exploited (ultraviolet rays do not easily reach the photoreactive semiconductor inside the agglomerated particles, and the ability is sufficient. When the mixed solution is applied to a highly breathable base material, that is, a base material having a large base material void diameter, it is easy to form a web-like film on the base material voids. There is a problem that the air permeability of the material is hindered.

【0031】

On the other hand, a film made 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 degree of hydration, it has the property of remarkably swelling and dispersing in water to easily form a stable aqueous colloid, and has a problem that the water resistance of the film is inferior. there were. Therefore, there are some who are somewhat uneasy about using it around water such as in the bathroom or kitchen, or in a high humidity environment such as indoors during the rainy season. In addition, the mechanical strength of the film is low, and there is a problem in terms of the abrasion resistance of the film. Further, in the mixed liquid of the photoreactive semiconductor and the film-forming inorganic substance, the dispersibility of the pigment (here, the photoreactive semiconductor and the film-forming inorganic substance) is good, and the above-mentioned metal oxide composite thermoplastic polymer has good dispersibility. Although there are few problems such as emulsions, some types of film-forming inorganic substances have extremely strong thixotropy properties, and the viscosity of the mixture of photoreactive semiconductors and film-forming inorganic substances becomes extremely high, and the mixture is supported on a substrate. There is a problem that it becomes difficult.

【0032】

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

【0033】

The photocatalytic filter of the present invention is a photocatalytic semiconductor because a functional mixture consisting of a photoreactive semiconductor, a metal oxide composite thermoplastic polymer emulsion, and a film-forming inorganic substance is uniformly dispersed and supported on a substrate. The photocatalytic activity can be effectively utilized. Therefore, even with a small amount of photoreactive semiconductor, it is possible to obtain a practically sufficient ability to remove harmful substances. Of course, the ability to remove harmful substances from photocatalytic filters improves as the content of photoreactive semiconductors increases. Therefore, in applications where a higher level of ability to remove harmful substances is required, such as increasing the content, etc. The content of the photoreactive semiconductor may be appropriately selected according to the intended purpose, and a photocatalytic filter having a desired ability to remove harmful substances may be produced.

【0034】

As described above, the content of the photoreactive semiconductor in the photocatalytic filter of the present invention may be any, but a particularly preferable content is 10 to 70% by weight of the total weight of the functional mixture. The effect of the content of the photoreactive semiconductor on the ability of the photocatalytic filter to remove harmful substances is particularly remarkable in the region where the content of the photoreactive semiconductor is less than 10% by weight of the total weight of the functional mixture, while 10 In the region of weight% or more, the ability of the photocatalytic filter to remove harmful substances gradually improves as the content of the photoreactive semiconductor increases, and the content is almost saturated at 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 is possible to obtain a photocatalytic filter having an extremely good ability to remove harmful substances. In the region where the content of the photoreactive semiconductor exceeds 70% by weight, the effect of improving the ability to remove harmful substances due to the increase in the amount of the photoreactive semiconductor is small, so that the content of 70% by weight or less may be practically acceptable. ..

【0035】

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. Therefore, even a small amount of the photoreactive semiconductor should be firmly fixed to the substrate. Is possible. Of course, the practical durability of the photocatalyst filter depends on the content of the mixture, so the content of the mixture should be appropriately selected according to the application and purpose to prepare a photocatalyst filter having the desired durability. Just do it. However, as described above, in order to obtain a photocatalytic filter having a high ability to remove harmful substances, the content of the photoreactive semiconductor is preferably 10 to 70% by weight of the total weight of the functional mixture, and therefore the metal. The content of the mixture of the oxide composite thermoplastic polymer emulsion and the film-forming inorganic substance is in a particularly preferable range of 30 to 90% by weight based on the total weight of the functional mixture. Regardless of the weight ratio of the metal oxide composite thermoplastic polymer emulsion / film-forming inorganic substance, a series of effects associated with the mixing of the two can be expected, but a particularly preferable weight ratio is 10/90 to It is in the range of 90/10. In the weight ratio, the advantages of the metal oxide composite thermoplastic polymer emulsion and the film-forming inorganic material can almost completely compensate for the disadvantages of each, and the effect of mixing the two can be maximized. be able to.

【0036】

The amount of the functional mixture containing the photoreactive semiconductor, the metal oxide composite thermoplastic polymer emulsion, and the film-forming inorganic substance on the base material is the basis weight of the base material and the target harmful effect. It may be selected appropriately according to the substance removal ability, but it is 5 to 200 g / m.²The degree is appropriate.

【0037】

Next, the base material will be 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. As the characteristics of the base material, it is required to have air permeability for transmitting harmful substances and light transmission for activating a photoreactive semiconductor. Examples of such a base material include non-woven fabrics and porous film-like ones, but non-woven fabrics are particularly preferable because they can easily control the basis weight and air permeability and are excellent in processability. is there.

【0038】

Non-woven fabrics include polyamide fibers, polyester fibers, polyalkylene paraoxybenzoate fibers, polyurethane fibers, polyvinyl alcohol fibers, polyvinylidene chloride fibers, polyvinyl chloride fibers, polyacrylonitrile fibers, polyolefin fibers, and phenol fibers. Synthetic fibers such as fibers, glass fibers, metal fibers, alumina fibers, inorganic fibers such as activated carbon fibers, natural fibers such as wood pulp, hemp pulp, and cotton linter pulp, recycled fibers, or hydrophilicity or flame retardant to these fibers. It is manufactured by various methods using fibers and the like that have been given functions such as sex.

【0039】

There are no particular restrictions on the method of manufacturing the non-woven fabric, and depending on the purpose and application, the web obtained by the dry method, wet papermaking method, melt blown method, spunbond method, etc. can be entangled with water, needle punched, stitched, etc. It can be produced by appropriately combining a method of developing strength by a physical method of the above, a heat bonding method such as a thermal bond method, and a bonding method using an adhesive such as a resin bond.

【0040】

In carrying a functional mixture containing a photoreactive semiconductor, a metal oxide composite thermoplastic polymer emulsion, and a film-forming inorganic substance on the substrate of the present invention, various blade coaters, roll coaters, air knife coaters, etc. Uses various coating devices such as bar coaters, rod blade coaters, short dwell coaters, comma coaters, die coaters, reverse roll coaters, kiss coaters, dip coaters, curtain coaters, extrusion coaters, gravure coaters, micro gravure coaters, and size presses. be able to. Further, after coating, a calendar such as a machine calendar, a TG calendar, a super calendar, or a soft calendar may be used for flattening and polishing, or an embossing device may be used for typing.

【0041】

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

【0042】

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

【0043】

Even more surprisingly, the addition of the adsorbent made the distribution of the photoreactive semiconductors in the photocatalytic filter more uniform, probably due to the adsorbent intervening between the photoreactive semiconductor particles. Not only does the photocatalytic reaction by the photoreactive semiconductor proceed more efficiently, but also the polymer component of the metal oxide composite thermoplastic polymer emulsion and the contact portion between the base material and the photoreactive semiconductor are reduced, and the photoreactive semiconductor It was found that an unexpected effect of further suppressing the deterioration of the photocatalytic filter due to the photocatalytic action can be obtained.

【0044】

Specific examples of the adsorbent according to the present invention include activated carbon, activated white clay, natural and synthetic zeolites, sepiolite, iron-based compounds such as iron oxide, zinc oxide, magnesium oxide, silica, silica-zinc oxide composite, and silica. -Alumina-zinc oxide composites, composite phyllosilicates, or mixtures thereof. The shape of these adsorbents is not particularly limited, but in consideration of mixing with a photoreactive semiconductor, a metal oxide composite thermoplastic polymer emulsion, and a film-forming inorganic substance, particulate ones are preferable. , Specific surface area is 50 ~ 2000m²It is possible to select and use the one of / g as appropriate, for example, in the case of activated carbon, 500 to 1500 m.²The one of / g is preferable.

【0045】

In the photocatalytic filter of the present invention, a functional mixture composed of 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, and thus photoreactive. The photocatalytic activity of the sex semiconductor and the adsorption ability of the adsorbent can be effectively utilized. Therefore, even with a small amount of photoreactive semiconductor and adsorbent, it is possible to obtain a practically sufficient ability to remove harmful substances. Of course, the harmful substance removing ability of the photocatalytic filter improves as the content of the mixture of the photoreactive semiconductor and the adsorbent increases. The content of the mixture of the photoreactive semiconductor and the adsorbent may be appropriately selected according to the application and purpose, such as increasing the amount, to produce a photocatalytic filter having a desired ability to remove harmful substances.

【0046】

As described above, the content of the mixture of the photoreactive semiconductor and the adsorbent in the photocatalytic filter of the present invention may be any, but a particularly preferable content is 20 to 70% by weight of the total weight of the functional mixture. is there. The effect of the content of the mixture of photoreactive semiconductors and adsorbents on the ability of the photocatalytic filter to remove harmful substances is particularly pronounced in the 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, the ability of the photocatalytic filter to remove harmful substances gradually improves as the content of the mixture increases, and the content is almost saturated at 70% by weight. Therefore, by setting the content of the mixture of the photoreactive semiconductor and the adsorbent to 20% by weight or more of the total weight of the functional mixture, it is possible to obtain a photocatalytic filter having an extremely good ability to remove harmful substances. In the 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 due to the increase in the amount of the mixture is small, so even if the content is 70% by weight or less, it is practical. Is okay.

【0047】

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. Therefore, even a small amount of a mixture of a photoreactive semiconductor and an adsorbent is used as a base material. It can be firmly fixed. Of course, the practical durability of the photocatalytic filter depends on the content of the mixture of the metal oxide composite thermoplastic polymer emulsion and the film-forming inorganic substance, so the content should be appropriately selected according to the application and purpose. , A photocatalytic filter having a desired durability may be produced. 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 must 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 in a particularly preferable range of 30 to 80% by weight based on the total weight of the functional mixture. Regardless of the weight ratio of the metal oxide composite thermoplastic polymer emulsion / film-forming inorganic substance, a series of effects associated with the mixing of the two can be expected, but a particularly preferable weight ratio is 10/90 to It is in the range of 90/10. In the weight ratio, the advantages of the metal oxide composite thermoplastic polymer emulsion and the film-forming inorganic material can almost completely compensate for the disadvantages of each, and the effect of mixing the two can be maximized. be able to.

【0048】

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 on the substrate is determined by the basis weight of the substrate and the purpose. It may be selected appropriately according to the ability to remove harmful substances, but it is 5 to 200 g / m.²The degree is appropriate.

【0049】

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

【0050】

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, an adsorbent, and a metal oxide composite thermoplastic polymer) is used in combination. Since it has extremely good dispersibility (referring to emulsions and film-forming inorganic substances) and has an appropriate liquid viscosity, even when a functional mixture is applied to a highly breathable substrate having a large void diameter, the voids are formed. The functional mixture can be uniformly applied to the surface of the substrate while maintaining a high degree of air permeability without blocking the substrate. Therefore, if the functional mixture of the present invention is used, the air permeability measured according to JIS L 1096 is 100 cm.³/cm²-It is easy to manufacture a highly breathable filter with a value of seconds or more, and it can be effectively used as a harmful substance removal filter for air purifiers and air conditioning systems.

【0051】

Depending on the application and purpose, a plurality of photocatalytic filters of the present invention may be laminated and used, or may be combined or used in combination with other suitable filter materials, functional sheets, or the like.

【0052】

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 remove harmful substances, and is also excellent in air permeability. it can. However, when it is used as a filter member for an air purifier or an air conditioning system, dust removal performance is also often required, and in order to satisfy this requirement, a dust removal filter is provided on at least one surface of the photocatalytic filter of the present invention. It may be laminated. In this case, it is preferable to use an electrostatic filter having excellent air permeability and high dust removal ability so as not to significantly impair the air permeability of the photocatalytic filter.

【0053】

The electrostatic filter according to the present invention is a filter that holds electric polarization semipermanently and exerts an electric force on the outside, and captures particles by the electrostatic force. Examples of the charging method include electro-electret, thermal electret, radio-electret, mechano-electret, photo-electret, magnet-electret, etc., but the electro-electret and thermal electret are mainly used in non-woven fabric filters industrially. , Polypropylene is often used as the filter material.

【0054】

Since the non-woven 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 split fiber electrostatic filter made by cutting a film that has been charged by corona discharge into a fibrous form and making it into a non-woven fabric, or applying a high voltage during melt blow spinning and melt spinning to charge the fibers like a thermal electret. The melt-blown non-woven fabric type electrostatic filter and the spunbond non-woven fabric type electrostatic filter, etc., can obtain a stable polarization charge. Since the melt-blown non-woven fabric type electrostatic filter alone has low mechanical strength, it is generally used by laminating a dry-type non-woven fabric or spunbond.

【0055】

[Example]

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto as long as the gist of the present invention is not exceeded.

【0056】

Preliminary operation 1 Ethyl orthosilicate (active ingredient) diluted with ethanol by adding 70 parts by weight of water to 100 parts by weight of phenoxy resin emulsion (manufactured by Toto Kasei, KE-316, active ingredient = 48% by weight) and heating to 60 ° C with stirring. = 40% by weight) 180 parts by weight was gradually added dropwise. Further heating was continued to remove ethanol from the system, and the metal oxide composite thermoplastic polymer emulsion 1 used in the examples was prepared.

【0057】

Preliminary operation 2 Emulsion polymerization solution of copolymerized polyester resin heated to 75 ° C (manufactured by Toyo Spinning Co., Ltd., byronal, active ingredient = 26% by weight) 100 parts by weight, ethyl orthosilicate diluted with ethanol (active ingredient = 40% by weight) 120% by weight The portion was gradually dropped. Further heating was continued to remove ethanol from the system, and the metal oxide composite thermoplastic polymer emulsion 2 used in the examples was prepared.

【0058】

Preliminary operation 3 Polyester fiber (fineness 3 denier, fiber length = 38 mm) / polyester fiber (fineness 6 denier, fiber length = 51 mm) / rayon fiber (fineness 3 denier, fiber length = 51 mm) = 50/30/20 Mix and have a basis weight of 50 g / m²The web was prepared, and the base material 1 used in the examples was prepared by imparting strength by needle punching.

【0059】

Preliminary operation 4 Polyester fiber (fineness 3 denier, fiber length = 38 mm) / polyester fiber (fineness 6 denier, fiber length = 51 mm) / rayon fiber (fineness 3 denier, fiber length = 51 mm) = 50/30/20 Mix and have a basis weight of 35 g / m²15g / m of acrylic emulsion resin in terms of active ingredient on the web²Impregnated and dried to give strength and used in the examples with a basis weight of 50 g / m²Substrate 2 was prepared.

【0060】

Example 1 As a photoreactive semiconductor, 5% by weight of titanium oxide (manufactured by Aerodil Japan, P25S6), 45% by weight of metal oxide composite thermoplastic polymer emulsion 1, and as a film-forming inorganic substance, synthetic smectite (manufactured by Kunimine Kogyo, Smecton SA) ) Containing 50% by weight of a functional mixture in base material 1 at 30 g / m²The photocatalytic filter of Example 1 was prepared by impregnation coating.

【0061】

Example 2 As a photoreactive semiconductor, 10% by weight of titanium oxide (manufactured by Aerodil Japan, P25S6), 45% by weight of metal oxide composite thermoplastic polymer emulsion 1, and as a film-forming inorganic substance, synthetic smectite (manufactured by Kunimine Kogyo, Smecton SA) 30 g / m of functional mixture containing 45% by weight of) on the base material 1.²The photocatalytic filter of Example 2 was prepared by impregnation coating.

【0062】

Example 3 As a photoreactive semiconductor, 30% by weight of titanium oxide (manufactured by Aerodil Japan, P25S6), 35% by weight of metal oxide composite thermoplastic polymer emulsion 1, and as a film-forming inorganic substance, synthetic smectite (manufactured by Kunimine Kogyo, Smecton SA) ) Containing 35% by weight of a functional mixture in base material 1 at 30 g / m²The photocatalytic filter of Example 3 was prepared by impregnation coating.

【0063】

Example 4 As a photoreactive semiconductor, 50% by weight of titanium oxide (manufactured by Aerodil Japan, P25S6), 3% by weight of metal oxide composite thermoplastic polymer emulsion 1, and as a film-forming inorganic substance, synthetic smectite (manufactured by Kunimine Kogyo, Smecton SA) ) Containing 47% by weight of a functional mixture in substrate 1 at 30 g / m²The photocatalytic filter of Example 4 was prepared by impregnation coating.

【0064】

Example 5 As a photoreactive semiconductor, 50% by weight of titanium oxide (manufactured by Aerodil Japan, P25S6), 5% by weight of metal oxide composite thermoplastic polymer emulsion 1, and as a film-forming inorganic substance, synthetic smectite (manufactured by Kunimine Kogyo, Smecton SA) 30 g / m of functional mixture containing 45% by weight of) on the base material 1.²The photocatalytic filter of Example 5 was prepared by impregnation coating.

【0065】

Example 6 As a photoreactive semiconductor, 50% by weight of titanium oxide (manufactured by Aerodil Japan, P25S6), 25% by weight of metal oxide composite thermoplastic polymer emulsion 1, and as a film-forming inorganic substance, synthetic smectite (manufactured by Kunimine Kogyo, Smecton SA) 30 g / m of functional mixture containing 25% by weight of) on the base material 1.²The photocatalytic filter of Example 6 was prepared by impregnation coating.

【0066】

Example 7 As a photoreactive semiconductor, 50% by weight of titanium oxide (manufactured by Aerodil Japan, P25S6), 45% by weight of metal oxide composite thermoplastic polymer emulsion 1, and as a film-forming inorganic substance, synthetic smectite (manufactured by Kunimine Kogyo, Smecton SA) ) Containing 5% by weight of a functional mixture in base material 1 at 30 g / m²The photocatalytic filter of Example 7 was prepared by impregnation coating.

【0067】

Example 8 As a photoreactive semiconductor, 50% by weight of titanium oxide (manufactured by Aerodil Japan, P25S6), 47% by weight of metal oxide composite thermoplastic polymer emulsion 1, and as a film-forming inorganic substance, synthetic smectite (manufactured by Kunimine Kogyo, Smecton SA) ) Containing 3% by weight of a functional mixture in base material 1 at 30 g / m²The photocatalytic filter of Example 8 was prepared by impregnation coating.

【0068】

Example 9 As a photoreactive semiconductor, 70% by weight of titanium oxide (manufactured by Aerodil Japan, P25S6), 15% by weight of metal oxide composite thermoplastic polymer emulsion 1, and as a film-forming inorganic substance, synthetic smectite (manufactured by Kunimine Kogyo, Smecton SA) ) Containing 15% by weight of a functional mixture in base material 1 at 30 g / m²The photocatalytic filter of Example 9 was prepared by impregnation coating.

【0069】

Example 10 As a photoreactive semiconductor, 80% by weight of titanium oxide (manufactured by Aerodil Japan, P25S6), 10% by weight of metal oxide composite thermoplastic polymer emulsion 1, and as a film-forming inorganic substance, synthetic smectite (manufactured by Kunimine Kogyo, Smecton SA) ) Containing 10% by weight of a functional mixture in base material 1 at 30 g / m²The photocatalytic filter of Example 10 was prepared by impregnation coating.

【0070】

Example 11 5% by weight of titanium oxide (manufactured by Aerosil Japan, P25S6) as a photoreactive semiconductor, 5% by weight of activated carbon (manufactured by Clare Chemical, Clarecol PW-W5) as an adsorbent, metal oxide composite thermoplastic polymer emulsion 30 g / m of a functional mixture containing 45% by weight of 2 and 45% by weight of synthetic hectrite (Laponite RD manufactured by Nippon Silica Industry Co., Ltd.) as a film-forming inorganic substance on the base material 2.²The photocatalytic filter of Example 11 was prepared by impregnation coating.

【0071】

Example 12 10% by weight of titanium oxide (manufactured by Nippon Aerosil, P25S6) as a photoreactive semiconductor, 10% by weight of composite phyllosilicate (manufactured by Mizusawa Chemical Co., Ltd., Mizukanite AP) as an adsorbent, metal oxide composite thermoplastic polymer 30 g / m of a functional mixture containing 40% by weight of Emulsion 2 and 40% by weight of synthetic hectolite (Laponite RD, manufactured by Nippon Silica Industry Co., Ltd.) as a film-forming inorganic substance on the base material 2.²The photocatalytic filter of Example 12 was prepared by impregnation coating.

【0072】

Example 13 25% by weight of titanium oxide (manufactured by Aerosil Japan, P25S6) as a photoreactive semiconductor, 25% by weight of activated carbon (manufactured by Clare Chemical, Clarecol PW-W5) as an adsorbent, metal oxide composite thermoplastic polymer emulsion 30 g / m of a functional mixture containing 3% by weight of 2 and 47% by weight of synthetic hectolite (manufactured by Nippon Silica Industry, Laponite RD) as a film-forming inorganic substance on the base material 2.²The photocatalytic filter of Example 13 was prepared by impregnation coating.

【0073】

Example 14 25% by weight of titanium oxide (manufactured by Nippon Aerosil, P25S6) as a photoreactive semiconductor, 25% by weight of composite phyllosilicate (manufactured by Mizusawa Chemical Co., Ltd., Mizukanite AP) as an adsorbent, metal oxide composite thermoplastic polymer 30 g / m of a functional mixture containing 5% by weight of Emulsion 2 and 45% by weight of synthetic hectolite (Laponite RD, manufactured by Nippon Silica Industry Co., Ltd.) as a film-forming inorganic substance on the base material 2.²The photocatalytic filter of Example 14 was prepared by impregnation coating.

【0074】

Example 15 25% by weight of titanium oxide (manufactured by Aerosil Japan, P25S6) as a photoreactive semiconductor, 25% by weight of activated carbon (manufactured by Clare Chemical, Clarecol PW-W5) as an adsorbent, metal oxide composite thermoplastic polymer emulsion 30 g / m of a functional mixture containing 25% by weight of 2 and 25% by weight of synthetic hectolite (Laponite RD, manufactured by Nippon Silica Industry Co., Ltd.) as a film-forming inorganic substance on the base material 2.²The photocatalytic filter of Example 15 was prepared by impregnation coating.

【0075】

Example 16 25% by weight of titanium oxide (manufactured by Nippon Aerosil, P25S6) as a photoreactive semiconductor, 25% by weight of composite phyllosilicate (manufactured by Mizusawa Chemical Co., Ltd., Mizukanite AP) as an adsorbent, metal oxide composite thermoplastic polymer 30 g / m of a functional mixture containing 45% by weight of Emulsion 2 and 5% by weight of synthetic hectolite (Laponite RD, manufactured by Nippon Silica Industry Co., Ltd.) as a film-forming inorganic substance on the base material 2.²The photocatalytic filter of Example 16 was prepared by impregnation coating.

【0076】

Example 17 25% by weight of titanium oxide (manufactured by Aerosil Japan, P25S6) as a photoreactive semiconductor, 25% by weight of activated carbon (manufactured by Clare Chemical, Clarecol PW-W5) as an adsorbent, metal oxide composite thermoplastic polymer emulsion 30 g / m of a functional mixture containing 47% by weight of 2 and 3% by weight of synthetic hectolite (manufactured by Nippon Silica Industry, Laponite RD) as a film-forming inorganic substance on the base material 2.²The photocatalytic filter of Example 17 was prepared by impregnation coating.

【0077】

Example 18 35% by weight of titanium oxide (manufactured by Nippon Aerosil, P25S6) as a photoreactive semiconductor, 35% by weight of composite phyllosilicate (manufactured by Mizusawa Chemical Co., Ltd., Mizukanite AP) as an adsorbent, metal oxide composite thermoplastic polymer 30 g / m of a functional mixture containing 15% by weight of Emulsion 2 and 15% by weight of synthetic hectolite (Laponite RD, manufactured by Nippon Silica Industry Co., Ltd.) as a film-forming inorganic substance on the base material 2.²The photocatalytic filter of Example 18 was prepared by impregnation coating.

【0078】

Example 19 40% by weight of titanium oxide (manufactured by Aerosil Japan, P25S6) as a photoreactive semiconductor, 40% by weight of activated carbon (manufactured by Clare Chemical, Clarecol PW-W5) as an adsorbent, metal oxide composite thermoplastic polymer emulsion 30 g / m of a functional mixture containing 10% by weight of 2 and 10% by weight of synthetic hectolite (Laponite RD, manufactured by Nippon Silica Industry Co., Ltd.) as a film-forming inorganic substance on the base material 2.²The photocatalytic filter of Example 19 was prepared by impregnation coating.

【0079】

Example 20 The amount of the functional mixture supported on the substrate is 10 g / m.²The photocatalytic filter of Example 20 was prepared in the same manner as in Example 6 except for the above points.

【0080】

Example 21 The amount of the functional mixture supported on the substrate is 50 g / m.²The photocatalytic filter of Example 21 was prepared in the same manner as in Example 6 except for the above points.

【0081】

Example 22 The amount of the functional mixture supported on the substrate is 10 g / m.²The photocatalytic filter of Example 22 was prepared in the same manner as in Example 15.

【0082】

Example 23 The amount of the functional mixture supported on the substrate is 50 g / m.²The photocatalytic filter of Example 23 was prepared in the same manner as in Example 15.

【0083】

Example 24 The photocatalytic filter of Example 24 was prepared in the same manner as in Example 6 except that a coloring pigment (EM Brown R manufactured by Toyo Ink Mfg. Co., Ltd.) was added as a colorant in an amount of 0.1% by weight based on the total weight of the functional mixture. did.

【0084】

Example 25 The photocatalytic filter of Example 25 was prepared in the same manner as in Example 15 except that a coloring pigment (EM Cobalt Blue manufactured by Toyo Ink Mfg. Co., Ltd.) was added as a colorant in an amount of 0.1% by weight based on the total weight of the functional mixture. did.

【0085】

Example 26 An electrostatic filter (manufactured by Mitsui Chemicals, Ltd., Syntex EL / EB20N) was attached to one surface of the photocatalytic filter of Example 6 to prepare a composite filter member of Example 26.

【0086】

Example 27 An electrostatic filter (manufactured by Mitsui Chemicals, Ltd., Syntex EL / EB20N) was attached to one surface of the photocatalytic filter of Example 15 to prepare a composite filter member of Example 27.

【0087】

Comparative example 1 As a photoreactive semiconductor, 30 g / m of a functional mixture containing 10% by weight of titanium oxide (manufactured by Aerodil Japan, P25S6) and 90% by weight of metal oxide composite thermoplastic polymer emulsion 1 on the base material 1.²The photocatalytic filter of Comparative Example 1 was prepared by impregnation coating.

【0088】

Comparative example 2 A functional mixture containing 10% by weight of titanium oxide (manufactured by Aerosil Japan, P25S6) as a photoreactive semiconductor and 90% by weight of synthetic smectite (manufactured by Kunimine Kogyo, Smecton SA) as a film-forming inorganic substance is used as a base material. 30g / m in 1²The photocatalytic filter of Comparative Example 2 was prepared by impregnation coating.

【0089】

Comparative example 3 As a photoreactive semiconductor, 30 g / m of a functional mixture containing 40% by weight of titanium oxide (manufactured by Aerodil Japan, P25S6) and 60% by weight of metal oxide composite thermoplastic polymer emulsion 1 on the base material 1.²The photocatalyst filter of Comparative Example 3 was prepared by impregnation coating.

【0090】

Comparative example 4 A functional mixture containing 40% by weight of titanium oxide (manufactured by Aerosil Japan, P25S6) as a photoreactive semiconductor and 60% by weight of synthetic smectite (manufactured by Kunimine Kogyo, Smecton SA) as a film-forming inorganic substance is used as a base material. 30g / m in 1²The photocatalytic filter of Comparative Example 4 was prepared by impregnation coating.

【0091】

Comparative example 5 As a photoreactive semiconductor, 30 g / m of a functional mixture containing 70% by weight of titanium oxide (manufactured by Aerosil Japan, P25S6) and 30% by weight of metal oxide composite thermoplastic polymer emulsion 1 on the base material 1.²The photocatalytic filter of Comparative Example 5 was prepared by impregnation coating.

【0092】

Comparative example 6 A functional mixture containing 70% by weight of titanium oxide (manufactured by Aerosil Japan, P25S6) as a photoreactive semiconductor and 30% by weight of synthetic smectite (manufactured by Kunimine Kogyo, Smecton SA) as a film-forming inorganic substance is used as a base material. 30g / m in 1²The photocatalytic filter of Comparative Example 6 was prepared by impregnation coating.

【0093】

Comparative example 7 10% by weight of titanium oxide (manufactured by Aerosil Japan, P25S6) as a photoreactive semiconductor, 10% by weight of activated carbon (manufactured by Clare Chemical, Clarecol PW-W5) as an adsorbent, metal oxide composite thermoplastic polymer emulsion 30 g / m of functional mixture containing 80% by weight of 2 on substrate 2²The photocatalytic filter of Comparative Example 7 was prepared by impregnation coating.

【0094】

Comparative Example 8 As a photoreactive semiconductor, 10% by weight of titanium oxide (manufactured by Nippon Aerosil, P25S6), as an adsorbent, 10% by weight of composite phyllosilicate (manufactured by Mizusawa Industrial Chemicals, Mizukanite AP), as a film-forming inorganic substance, synthetic hect 30 g / m of functional mixture containing 80% by weight of light (Laponite RD manufactured by Nippon Silica Industry Co., Ltd.) on base material 2.²The photocatalytic filter of Comparative Example 8 was prepared by impregnation coating.

【0095】

Comparative Example 9 20% by weight of titanium oxide (manufactured by Aerosil Japan, P25S6) as a photoreactive semiconductor, 20% by weight of activated carbon (manufactured by Clare Chemical, Clarecol PW-W5) as an adsorbent, metal oxide composite thermoplastic polymer emulsion 30 g / m of functional mixture containing 60% by weight of 2 on substrate 2²The photocatalytic filter of Comparative Example 9 was prepared by impregnation coating.

【0096】

Comparative example 10 20% by weight of titanium oxide (manufactured by Nippon Aerosil, P25S6) as a photoreactive semiconductor, 20% by weight of composite phyllosilicate (Mizusawa Industrial Chemicals, Mizusawa Industrial Chemicals, Mizusawa Industrial Chemicals) as an adsorbent, synthetic hect as a film-forming inorganic substance 30 g / m of functional mixture containing 60% by weight of light (Laponite RD manufactured by Nippon Silica Industry Co., Ltd.) on base material 2.²The photocatalytic filter of Comparative Example 10 was prepared by impregnation coating.

【0097】

Comparative Example 11 35% by weight of titanium oxide (manufactured by Aerosil Japan, P25S6) as a photoreactive semiconductor, 35% by weight of activated carbon (manufactured by Clare Chemical, Clarecol PW-W5) as an adsorbent, metal oxide composite thermoplastic polymer emulsion 30 g / m of functional mixture containing 30% by weight of 2 on substrate 2²The photocatalytic filter of Comparative Example 11 was prepared by impregnation coating.

【0098】

Comparative Example 12 35% by weight of titanium oxide (manufactured by Aerosil Japan, P25S6) as a photoreactive semiconductor, 35% by weight of composite phyllosilicate (Mizukanite AP, manufactured by Mizusawa Industrial Chemicals) as an adsorbent, synthetic hect as a film-forming inorganic substance 30 g / m of functional mixture containing 30% by weight of light (Laponite RD manufactured by Nippon Silica Industry Co., Ltd.) on base material 2.²The photocatalytic filter of Comparative Example 12 was prepared by impregnation coating.

【0099】

As described above, the photocatalyst filter and the composite filter member obtained in the examples were tested by the following methods and their performances were evaluated.

【0100】

[Deodorizing performance A] The photocatalytic filter was cut into 10 cm x 10 cm and placed on the bottom of a 5.6 liter airtight container equipped with a 6 W black lamp so that the distance from the black lamp was 2 cm. After injecting 100 ppm of acetaldehyde into the container and leaving it for 20 minutes without turning on the black lamp, the acetaldehyde concentration (ppm) in the container was measured by gas chromatography.

【0101】

After the tests of [Deodorizing performance B] and [Deodorizing performance A] were completed, a 6W black lamp was turned on and irradiated with ultraviolet rays, and the acetaldehyde concentration (ppm) in the container 20 minutes after the irradiation with ultraviolet rays was measured by a gas chromatograph.

【0102】

[Breathability] Breathability of photocatalytic filter (cm)³/cm² Seconds) were measured using a Frazier type tester in accordance with JIS L 1096.

【0103】

[Abrasion resistance] The surface of the photocatalyst filter was rubbed with a cotton swab to observe the abrasion resistance. The rubbing resistance is "poor" when the functional mixture is observed to fall off from the photocatalyst filter after rubbing less than 50 round trips, and the functional mixture is dropped from the photocatalyst filter after rubbing 50 to 199 round trips. When observed, the abrasion resistance is "normal", and when the functional mixture is dropped from the photocatalyst filter after 200 to 500 round trips, the abrasion resistance is "good", which is more than 500 round trips. When the functional mixture was observed to fall off from the photocatalyst filter after repeated rubbing, or when the functional mixture was not removed, the scratch resistance was judged to be "excellent".

【0104】

[Water resistance] After the photocatalyst filter was sufficiently immersed in water, the surface of the photocatalyst filter was rubbed with a cotton swab to observe the water resistance. The rubbing resistance after immersion in water was evaluated by the same method as [rubbing resistance], and used as an index of water resistance.

【0105】

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

【0106】

[Filter performance] The filter performance of the composite filter members of Example 26 and Example 27 was investigated. First, the composite filter members of Examples 26 and 27 are processed into pleats to form a filter unit (amount of composite filter members used = about 1 m).²) Was prepared, and the filter unit was combined with a 30 W sirocco fan and two 6 W black lamps to prepare an experimental air purifier. The filter performance of the composite filter members of Examples 26 and 27 was evaluated using the acetaldehyde removal performance and the cigarette smoke particle removal performance of the air purifier as indexes. First, 1m³Place the air purifier in a closed stainless steel container, inject 10 ppm of acetaldehyde into the container, operate the air purifier for 30 minutes, and then measure the acetaldehyde concentration (C: ppm) in the container with a gas chromatograph. Then, the removal rate of acetaldehyde (%: 100 × (10-C) / 10) was determined. Next, after injecting five mild seven cigarette smokes into the container, the air purifier was operated for 30 minutes. Amount of airborne dust in the container immediately after injecting cigarette smoke (A: mg / m)³), Amount of suspended dust in the container after operating the air purifier (B: mg / m)³) Was measured with a dust meter, and the removal rate of cigarette smoke particles (%: 100 × (AB) / A) was determined.

【0107】

The results of the above test items are shown in Tables 1-6.

【0108】

[table 1]

<img file="JPH11114330A_D0001.tif" />【0109】

[Table 2]

<img file="JPH11114330A_D0002.tif" />【0110】

[Table 3]

<img file="JPH11114330A_D0003.tif" />【0111】

[Table 4]

<img file="JPH11114330A_D0004.tif" />【0112】

[Table 5]

<img file="JPH11114330A_D0005.tif" />【0113】

[Table 6]

<img file="JPH11114330A_D0006.tif" />【0114】

The photocatalytic filters of Examples 1 to 25 showed good results in all the evaluation items. In particular, the photocatalytic filters of Examples 11 to 19, 22, 23, and 25 in which an adsorbent is mixed in a functional mixture not only have a certain degree of deodorizing performance even when not irradiated with ultraviolet rays, but also have a photoreactive semiconductor when irradiated with ultraviolet rays. It was found that it exhibits excellent deodorizing performance due to the synergistic effect with. In addition, the photocatalytic filters of Examples 24 and 25 in which the colorant was mixed in the functional mixture had an excellent decorative feeling. Further, it was found that the composite filter members of Examples 26 and 27 in which electrostatic filters are laminated have excellent dust removal / deodorizing performance and effectively act as filter members for air purifiers, air conditioning systems, and the like.

【0115】

In the photocatalyst filters of Comparative Examples 1, 3, 5, 7, 9 and 11 in which the metal oxide composite thermoplastic polymer emulsion was used alone as the binder, the deodorizing performance which seems to be caused by the aggregated particles of the functional mixture. In addition to the decrease in the amount of the functional mixture and the dropout of the functional mixture, when the functional mixture was supported on the substrate, a web-like film was easily formed in the voids of the substrate, and the air permeability was also inferior. On the other hand, the photocatalytic filters of Comparative Examples 2, 4, 6, 8, 10 and 12 using a film-forming inorganic substance alone as a binder are excellent in deodorizing performance and air permeability, but have excellent mechanical strength and water resistance of the film. It was insufficient and was inferior in practical durability.

【0116】

When the electrostatic filters were not laminated, the dust removal performance was insufficient and the dust removal / deodorization filter member did not function effectively.

【0117】

[Effect of the invention]

The photocatalytic filter of the present invention, which carries a photoreactive semiconductor, a metal oxide composite thermoplastic polymer emulsion, and a functional mixture containing a film-forming inorganic substance on a substrate, has not only deodorizing performance but also breathability and resistance. It showed excellent effects in various properties required for a photocatalytic filter, such as abrasion resistance, water resistance, and durability. Further, in the present invention, a particularly excellent effect was exhibited by setting these components to a specific component ratio. Further, it was found that the photocatalytic filter in which an adsorbent was added as a component to the above configuration further improved the deodorizing performance. Further, the composite filter member in which the electrostatic filter is laminated on the photocatalyst filter having the above configuration has extremely excellent dust removal / deodorizing performance, and has shown excellent effects in, for example, acetaldehyde removal performance and cigarette smoke particle removal performance. ..