JPH09225320A - Porous microcapsule-shaped photocatalyst - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a photo-semiconducting substance which can develop a good catalytic function when mixed into a base material constituent by installing a wall which contains the photo-semiconducting substance and is composed of a porous substance. SOLUTION: A form of porous microcapsule is made to prevent the direct contact between a photo-semiconducting substance and a base material constituent without cutting off light from the photo-semiconducting substance, and a porous microcapsule-shaped photocatalyst is formed to have a wall which contains the photo-semiconductive substance and is composed of a porous substance. At least one kind selected from the group consisting of titanium dioxide, tungsten trioxide, strontium titanate is used as the photo-semicomducting substance, and a conductive substance is made to be contained with the photo- semiconducting substance as required. Tin oxide is used preferably as the conductive substance.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a porous microcapsule photocatalyst.

[0002]

2. Description of the Related Art In recent years, the photocatalytic action of light from semiconducting materials is not limited to catalysis of chemical reactions such as photolysis of water.
It has attracted attention in many fields such as decomposition and removal of environmental pollutants in water and air, deodorization, and bactericidal action. In particular, regarding the bactericidal action, a new antibacterial method mainly utilizing the action of titanium oxide as a light semiconductive substance has been proposed (Japanese Patent Laid-Open No. 1544/1993).
No. 73). The antibacterial method using the conventional antibacterial agent has durability of antibacterial performance, deterioration of weather resistance of the base material due to addition of the antibacterial agent,
While there are many problems such as safety problems due to drug spillage, this method is a method of performing sterilization by a catalytic action without using a drug, so attention is paid to it in terms of safety and durability. There is.

On the other hand, since the photo-semiconductor is generally a fine powder, it is necessary to immobilize the powder when it is applied to the fields such as decomposition and removal of environmental pollutants, deodorization and sterilization. Therefore, attempts have been made to use the photo-semiconductor by supporting it on various base materials. The simplest method is to use a light semiconducting substance by dispersing it in a base material constituent such as an organic polymer, but there is a problem that the base material constituent deteriorates over a long period of time. It is considered that the above-mentioned deterioration is caused by radicals generated by the action of the light semiconducting substance, and it is disclosed that the deterioration can be avoided when a fluororesin is used (JP-A-4-28).
No. 4851), improvement in the case of using other organic materials or the like is desired in order to widen the range of material selection.

When a powder having a photocatalytic action such as titanium oxide is used as a pigment, a method of coating the surface of the powder with an inorganic compound such as silica or alumina in order to prevent the deterioration phenomenon of the material as described above. Is used. If the surface of the photo-semiconductor is completely covered by this method, the deterioration can be prevented, but since the photo-semiconductor is shielded from the light, the photocatalytic action cannot be obtained.

[0005]

SUMMARY OF THE INVENTION In view of the above problems, the present invention has an optical semiconducting property which, when mixed with a constituent component of a base material, exhibits excellent catalytic performance without degrading the constituent component of the base material. To provide the substance.

[0006]

In the present invention, as means for preventing direct contact between the photo-semiconductor and the constituent component of the substrate without blocking light from the photo-semiconductor,
The form of porous microcapsules is used. That is, the porous microcapsule-like photocatalyst body of the present invention is characterized by including a photosemiconductor and having a wall made of a porous substance.

<Photosemiconductor> The photosemiconductor of the present invention has photocatalytic activity. Specifically, metal oxides such as zinc oxide, titanium dioxide (hereinafter simply referred to as "titanium oxide"), tungsten oxide, strontium titanate, ferric oxide; zinc sulfide, cadmium sulfide, lead sulfide, selenium. Metal chalcogenides such as zinc oxide and cadmium selenide; Group I such as silicon and germanium
Group V elements; III-V compounds such as gallium-phosphorus, gallium-arsenic, and indium-phosphorus; organic semiconductors such as polyacetylene, folipyrrole, polythiophene, polyaniline, and polyvinylcarbazole.

Among the above-mentioned photoconductive materials, metal oxides such as titanium oxide, tungsten trioxide and strontium titanate are preferable from the practical viewpoint. In particular, titanium oxide is easy to use because it is easily available, and any of amorphous, rutile, and anatase types can be used. When used for the purpose of imparting an antibacterial function or removing nitrogen oxides, anatase type titanium oxide has the highest activity. Further, in many cases, titanium oxide, which is generally used as a white pigment, is not preferable because the surface thereof is completely coated with alumina or silica, which lowers the photocatalytic action. The above-mentioned photo-semiconductors may be used alone or in combination of two or more kinds.

<Conductive Material> The photo-semiconductive material improves the catalytic effect when used together with a conductive material. The conductive substance used may be carbon powder (fiber) or metal powder (fiber) generally used for imparting conductivity. Examples include carbon black, silver, copper, gold, iron, aluminum, nickel, platinum, palladium, tin oxide, indium oxide and the like. Alternatively, the surface may be coated with a non-conductive material as a core material. Examples thereof include silver-plated fine particles, aluminum-coated fine particles, and barium sulfate fine particles whose surface is coated with tin oxide.

Among the above conductive materials, tin oxide fine particles, which are easily available and are relatively inexpensive, and barium sulfate fine particles whose surface is coated with tin oxide, are preferable from the practical viewpoint.
Tin oxide to which 0.1 to 20% by weight of antimony oxide is added exhibits high conductivity and is preferably used.

The conductive substance is used so as to be in contact with the photo-semiconductive substance. For this purpose, it is possible to include iron oxide in a part of the structure of the photo-semiconductor or to carry it on the surface of the photo-semiconductor by a physical or chemical action. Sufficient effects can be obtained by simply using a mixed powder of a photo-semiconductor and a conductive substance.

The amount of the conductive material added to the light semiconductive material is 0.01 to 100 parts by weight of the light semiconductive material.
Preferably it is 100 parts by weight. If the amount is less than this, the effect of adding the conductive substance is difficult to recognize. If the amount is larger than this, the effect is not further enhanced, but in the case of also serving as a carrier for the photo-semiconductive substance, the added amount may be increased. In particular, when the mixture is simply used regardless of the method for contacting the conductive substance and the light semiconducting substance, it is preferably 1 to 100 parts by weight with respect to 100 parts by weight of the light semiconducting substance.

In the following, in the porous microcapsule-shaped photocatalyst of the present invention, the emulsion for producing the microcapsules is "A / B type" and "(A1 / B) / A2 type".
Two cases will be described.

<A/B type> The above-mentioned porous microcapsules are generally used for preparing emulsions such as oil-in-water type (O / W type) and water-in-oil type (W / O type). Can be manufactured by In this case, a solvent B that is incompatible with the solvent A is used, and the solvent A contains a photo-semiconductor and a component that constitutes the wall of the porous microcapsule by curing or solidifying, After the B-type emulsion is prepared, the wall constituents are hardened or solidified to obtain the “A / B” of the above-mentioned O / W type, W / O type or the like.
Microcapsule-shaped photocatalysts can be made with "type" emulsions.

<(A1 / B) / A2 type> Further, the photo-semiconductor is completely removed by a method of preparing a multi-phase emulsion such as so-called (O / W) / O type or (W / O) / W type. It is possible to obtain microcapsules encapsulated in. In this case, the solvents A1 and A2 and the solvent B which is incompatible with A1 and A2 are used.
The component constituting the wall of the porous microcapsule by being hardened or solidified into (A1 / B) / A
After the type 2 emulsion is prepared, the wall constituents are cured or solidified to give the above (O / W) / O type, (W / O)
It is possible to prepare a microcapsule-shaped photocatalyst body using a "(A1 / B) / A2 type" emulsion such as / W type.

<Method of Suppressing Exposure of Photosemiconductor by Using Encapsulated Powder> As means for suppressing exposure of the photosemiconductor to the surface, microcapsules containing the photosemiconductor are prepared. The method of preparing microcapsules can be performed again by using the microcapsules as the encapsulated powder. The manufacturing method of the microcapsule in each stage in this case is the same as the above. In addition, a method of preparing porous silica containing a photo-semiconductor and using the pulverized product as the microencapsulated powder is also effective for suppressing the exposure of the photo-semiconductor. .

Hereinafter, when simply referred to as "microcapsule", it means the porous microcapsule-like photocatalyst of the present invention.

<Incompatible Solvent> The incompatible solvent means a solvent which separates when mixed and shaken. The solvent used in the present invention contains a component (hereinafter, referred to as "wall constituent component") that constitutes the wall of the porous microcapsule by curing or solidifying (A in the A / B type, ( A1 / B) / B2 in A2 type), which has compatibility with the component,
As the other solvent, a solvent that is not compatible with this can be appropriately used. For example, when an organic solvent is used as a solvent that is incompatible with water, the organic solvent used preferably has a solubility in water of 10% or less at room temperature.

<Wall Constituent> As the wall constituent of the microcapsule of the present invention, a solvent (A
In the / B type, it means A, and in the (A1 / B) / A2 type, it means B. ), Which is soluble or dispersible in, and can be cured or solidified, and which does not easily deteriorate even after the cured or solidified material comes into direct contact with the photoconductive substance. select. Materials that satisfy this condition include inorganic substances such as silica and alumina, and Teflon resin. More specifically, an emulsion is prepared using water glass and aluminum chloride, and after curing, microcapsules having silica and alumina walls can be obtained. Considering the light transmittance required for the photocatalytic reaction, a glassy material such as silica is particularly preferable as the wall constituent component.

As a method for making the microcapsules porous, a method of preparing an emulsion by using an inorganic material mixed with an organic substance as a wall constituent, and baking or dissolving only the organic substance with a solvent after forming the microcapsules, Examples thereof include a method in which a water-soluble or oil-soluble salt or the like is mixed in the wall constituent components and then the salt is dissolved.

The A / B type porous microcapsules can be formed by a known microcapsule forming method such as that shown in Japanese Patent Publication No. 54-6251. Etc. can be controlled. The porosity is also not particularly limited, but if the photo-semiconductor material is completely covered, the catalytic action will be reduced.

As a method for forming (A1 / B) / A2 type porous microcapsules, the above-mentioned Japanese Patent Publication No. 54-6251 is used.
It can be carried out by combining a known method as shown in No. 6 with a method for preparing a multiphase emulsion.

The size of the porous microcapsules is not particularly limited, but in the case of imparting transparency or when coloring is not preferable, the diameter (major axis) 0.4
Those having a size of μm or less are preferred. When the refractive index of the wall component of the microcapsule, the refractive index of the light-conducting substance to be encapsulated, and the refractive index of the base component of the target substance to which the microcapsule is added are close to each other, the above range is exceeded. However, transparency can be imparted.

If the amount of the photo-semiconductor contained in the microcapsules is too large, the photoconductive substance cannot be completely encapsulated and floats outside the microcapsules. If the amount is too small, the photocatalytic effect is not exhibited. An appropriate amount is 5 per 100 parts by weight of wall material constituents.
２００200 parts by weight.

<Lipophilic treatment> When a porous microcapsule is prepared from an (O / W) / O type emulsion using an inorganic photo-semiconductor, the photo-semiconductor is lipophilic. It should be processed and used. Further, when the conductive substance is included together with the photo-semiconductive substance powder, the conductive substance is also preferably subjected to lipophilic treatment.

The lipophilic treatment method may be a lipophilic treatment method generally applied to powder.
Has the property of adsorbing or binding to the powder used, and
A substance having a molecular structure with a high affinity for the organic solvent A1 used can be used. As the substance used in the lipophilic treatment, when the photoconductive substance and the conductive substance are inorganic powders, palmitic acid, higher fatty acids such as stearic acid,
Reactive silicone oil, silane coupling agent, titanate coupling agent, aluminate coupling agent,
Examples thereof include zirconate coupling agents. In particular, it is preferable to use a coupling agent or silicone oil having a functional group that chemically bonds to the powder surface.

As the silane coupling agent, vinyltriethoxysilane, vinyltrimethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, β- (3,4)
Epoxycyclohexyl) ethyltrimethoxysilane,
γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl)-
γ-aminopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, phenyltriethoxysilane, methyltriethoxysilane, methyltrimethoxysilane, polyethylene oxide modified silane monomer,
Examples thereof include polymethylethoxysiloxane and hexamethyldisilazane.

As the titanate coupling agent,
Isopropyltriisostearoyl titanate, tetraisopropyl bis (dioctyl phosphite) titanate, tetraoctyl bis (ditridecyl phosphite)
Titanate, tetra (2,2'-diallyloxymethyl-1-butyl) bis (di-tridecyl) phosphite titanate, isopropyl tridecylbenzenesulfonyl titanate, bis (dioctyl pyrophosphate) oxyacetate titanate, bis (dioctyl pyrophosphate) Ethylene titanate, isopropyl trioctanoyl titanate, isopropyl dimethacryl isostearoyl titanate, isopropyl isostearoyl diacrylic titanate, isopropyl tri (dioctyl phosphate) titanate, isopropyl tricumylphenyl titanate, isopropyl tri (N-aminoethyl-aminoethyl) titanate, etc. Is mentioned.

Examples of the aluminate coupling agent include acetoalkoxyaluminum diisopropylate and acetoalkoxyaluminum diisobutyrate. Examples of the zirconate coupling agent include zirconate compounds having a reactive functional group with a neopentyl (diallyl) oxy group such as noopentyl (diallyl) oxytrineodecanoylzirconate and neopentyl (diallyl) oxytri (dioctyl) phosphate zirconate. Etc.

<Preparation Method of Emulsion> In the production of the microcapsules of the present invention, the preparation method of the emulsion may be a usual method, and a stirring method, a shaking method, an emulsifying device such as a homogenizer may be used. It depends on the method used.
The amount of the solution used in the emulsification and the type and amount of the additive such as the emulsifying dispersant are the A / B type or (A1 /
It is not limited as long as it is B) / A2 type.

As the above-mentioned emulsifying dispersant, for example, when preparing an O / W type emulsion, H. L. B value is 8-18, W
In the case of preparing an O / O type emulsion, H. L. B value is 3.5
It is preferable to use the ones of -6.

When an emulsion of (A1 / B) / A2 type is prepared, for example, H. L. An O / W type emulsion was prepared by using an emulsifying dispersant having a B value of 8 to 18, and using this,
Further, H. L. An (O / W) / O type emulsion may be prepared using an emulsifying dispersant having a B value of 3.5 to 6. Also,
When preparing a (W / O) / W type emulsion, H. L.
A W / O type emulsion was prepared using an emulsifying dispersant having a B value of 3.5 to 6, and this was further added to H.O. L. B value is 8-18
It may be added to the organic solvent containing the emulsifying dispersant.

A general-purpose surfactant may be used as the emulsifying dispersant. Further, clay minerals can be used in place of or in combination with the surfactant to stabilize the emulsion interface. In particular, when a two-phase emulsion having a large difference in specific gravity is prepared, the interface can be stabilized by using a clay mineral as an emulsifying dispersant. By stabilizing the emulsion interface, it is possible to obtain microcapsules in which the light semiconducting substance is reliably encapsulated, and for the purpose of avoiding direct contact between the base component and the light semiconducting substance. Is effective.

Further, when a nonionic surfactant is used as an emulsifying dispersant, the emulsion becomes unstable at a temperature above the cloud point, but clay minerals do not have such a cloud point and are in a high temperature range. However, a stable emulsion can be obtained.

<Clay Mineral> The type of the clay mineral is selected in consideration of the properties of the phase containing the photo-semiconductor which is the inclusion. For example, when a photosemiconductor is dispersed or dissolved in an organic solvent and then suspended in an aqueous solution (when preparing an O / W type emulsion), a clay mineral that has been subjected to non-denaturation or partially organic treatment Is preferably used by adding it to the above aqueous solution. As the above-mentioned clay mineral which has not been modified or partially subjected to organic treatment, those generally used for thickening / gelling an aqueous system can be used as they are.

When the photo-semiconductor material is dispersed or dissolved in water and then suspended in an organic solvent (when preparing a W / O type emulsion), an organically treated clay mineral is used as described above. It is preferably used by adding it to an organic solvent. Clay minerals that have been subjected to the above organic treatment are generally organic solvent-based thickeners
What is used for gelation can be used as it is.

As the above-mentioned clay mineral, both natural products and synthetic products can be used as long as they have gelling ability. Specific examples include montmorillonite, saponite, hectorite, beidellite, nontrolite, sauconite and vermiculite.

As the above-described organically treated clay mineral or partially organically treated clay mineral, commercially available ones may be used, but the above-exemplified clay mineral and quaternary ammonium salt are reacted. It can also be obtained by The reaction method may be a method in which the exchangeable cation of the clay mineral and the quaternary ammonium ion are efficiently exchanged. For example, it can be synthesized by preparing a slurry in which clay mineral is dispersed in water, and dropping the aqueous solution of the quaternary ammonium salt while stirring the slurry. Specific examples of the quaternary ammonium salt include benzyldimethylstearylammonium chloride, stearyltrimethylammonium chloride, dimethyldioctadecylammonium chloride and methyltrioctylammonium chloride.

<Method of Utilizing Photosemiconductive Material> The porous microcapsule-shaped photocatalyst of the present invention contains various additives together with various additives.
It can be added to base materials such as synthetic resins to form molded bodies, used as paints, supported on the surface of various materials, dispersed alone in solutions, packed in columns, etc. Can be used in form. It is speculated that photo-semiconductors react with water present in the air to produce active oxygen such as hydrogen peroxide and hydroxy radicals. Antibacterial and antifungal treatment, nosocomial infection prevention, etc., nitrogen oxide, sulfur oxide, decomposition and removal of environmental pollutants such as trihalomethane, ammonia, aldehyde,
It is possible to perform decomposing / removing treatment of substances causing offensive odors such as various organic acids, antifouling treatment for imparting a self-cleaning action to the exterior material, waste liquid treatment utilizing a catalytic action, and the like.

The microcapsule photocatalyst of the present invention comprises
Among the above-mentioned treatments, it is particularly suitable for antibacterial and antifungal treatment, and treatment for removing gaseous components such as environmental pollutants and malodorous substances. In the antibacterial and antifungal treatment, unlike the conventional techniques involving the elution of chemicals and the like, the durability and safety are excellent.
In the process of removing the gas component, in addition to the catalytic action of the photo-semiconductor, the porous substance which is the wall of the microcapsule enhances the adsorption effect of the gas to be treated. The gas treatment with the photo-semiconductor of the present invention utilizes a photocatalytic action, so that the gas adsorption effect is not only large as compared with the conventional technique which only utilizes the adsorption of the porous substance, Very good sustainability. Furthermore, as compared with the state in which the photo-semiconductor material is exposed, it is possible to suppress a decrease in activity due to non-poisoning of the catalyst surface.

If a porous microcapsule-shaped photocatalyst containing the photo-semiconductor material of the present invention and comprising a wall of a porous material is used, the contact between the photo-semiconductor material and the constituent components of the base material can be achieved. Since it is possible to avoid the deterioration caused by the above and to select the base material constituent without being limited by the deterioration, it is advantageous in various usage forms. When a photo-semiconductive substance is added to a general-purpose resin to form a molded body or a coating, the above-mentioned deterioration is unavoidable in the prior art, which is a major obstacle to practical use. The advantage of not being restricted by the constituent components of the material has an extremely great industrial significance.

As described above, the photo-semiconductor material of the present invention has a great advantage when used in combination with an organic resin. Most of the commonly used synthetic resins are materials that cannot carry a photo-semiconductor, because deterioration becomes a problem unless the porous microcapsule photocatalyst body of the present invention is used. Specific examples of such materials include polyolefin resins such as polyethylene resins and polypropylene resins; polyurethane resins; alkyd resins, polyester resins such as unsaturated polyesters; poly (meth) acrylic resins; polyamide resins; polystyrene resins, polyvinyl chloride. Vinyl compounds (co) polymers such as resins, polyvinyl acetate resins and polyvinyl alcohol resins; formaldehyde resins such as phenol resins and amino resins (referred to as formaldehyde-crosslinking type resins); allyl resins; epoxy resins and the like. To be

When the porous microcapsule-shaped photocatalyst body of the present invention is added to a general-purpose synthetic resin to be used as a molded body or a paint, if the amount of the photo-semiconductor is too small, the photocatalytic action is insufficient. Considering the content of the photo-semiconductor in the microcapsule photocatalyst, the amount of the photo-semiconductor should be 5 parts by weight or more with respect to 100 parts by weight of the synthetic resin which is the main component of the molded product and the paint. Is preferably added to.
On the other hand, if the amount of porous microcapsules added is too large,
Although it depends on the particle size of the microcapsules, the surface condition of the molded body or the coated surface is deteriorated and the strength is reduced. Therefore, the microcapsules are added in an amount of 1000 parts by weight or less relative to 100 parts by weight of the synthetic resin. It is preferable.

When a molded product is obtained by kneading or dry blending in a synthetic resin, the amount of microcapsules added is 100 parts by weight based on 100 parts by weight of the synthetic resin from the viewpoint of strength and workability of the molded product. It is preferable not to exceed a part.

The porous microcapsule-shaped photocatalyst of the present invention contains a photosemiconductor, and the amount of the microcapsule exposed on the surface of the microcapsule is in a state of being very small compared to the amount of inclusion or not at all. Therefore, most of short-lived components such as hydroxy radicals generated by irradiation of light on the porous microcapsule-shaped photocatalyst body disappear before passing through the wall of the microcapsule and do not leak out of the microcapsule.
It is presumed that long-lived components such as hydrogen peroxide permeate outside the microcapsules to act.

[0046]

The present invention will be described in more detail with reference to the following examples. Example 1 9 parts by weight of titanium oxide (manufactured by Wako Pure Chemical Industries, anatase type, primary particle size 0.3 μm) and tin oxide containing antimony oxide (“T-1” manufactured by Mitsubishi Materials, particle size 0.02 μm) 1 50 g of a powder mixed with parts by weight (hereinafter referred to as "titanium oxide / tin oxide mixed powder") was added to 500 ml of an aqueous sodium silicate solution (4 mol / l of silicon dioxide) and stirred for 10 minutes to obtain a uniform suspension. Was prepared. The above suspension was added to 1 liter of a sorbitan monooleate solution in toluene (1% by weight), and the mixture was shaken for 5 minutes on a shaker to give W /
An O type emulsion was prepared. Next, the above emulsion oil was added to 4 L of an ammonium sulfate aqueous solution (1 mol / l) with stirring and reacted for 30 minutes. After the completion of the reaction, each operation of filtration, washing with water and drying (110 ° C., 24 hours) was performed to include titanium oxide and have an average particle size of 6 having a wall made of silica.
A microcapsule photocatalyst having a size of μm was obtained.

Example 2 Titanium oxide / tin oxide mixed powder 50 used in Example 1
In the same manner as in Example 1, except that 50 g of titanium oxide (manufactured by Wako Pure Chemical Industries, anatase type, primary particle size 0.3 μm) was used instead of g, it was composed of silica. A microcapsule photocatalyst body having a wall and an average particle diameter of 7 μm was obtained.

Example 3 Titanium oxide / tin oxide mixed powder 50 used in Example 1
g to sodium silicate aqueous solution (2m converted to silicon dioxide
ol / l) was added to 500 ml and stirred for 20 minutes to prepare a uniform suspension. The above suspension was added to 1 liter of a sorbitan monostearate solution in toluene (3% by weight) and emulsified for 5 minutes with an emulsifier to prepare a water-in-oil emulsion.
Next, the above emulsion oil was treated with an aqueous solution of calcium chloride (1.5 mo
(l / l) 3 l was added with stirring and reacted for 1 hour. After the completion of the reaction, the same operation as in Example 1 was carried out to include titanium oxide and have a wall made of silica and having an average particle diameter of 4 μm.
m photocatalyst in the form of microcapsules was obtained.

Example 4 4 g of titanium oxide / tin oxide mixed powder used in Example 1
Sodium silicate solution (4mo in terms of silicon dioxide
(1/1) 50 ml and stirred for 10 minutes to prepare a uniform suspension. The above suspension was added to 150 ml of a benzene solution of sorbitan monostearate (1% by weight),
Shaking was performed for 5 minutes using a shaker to prepare a W / O type emulsion. Next, the above emulsion was added to 500 ml of an ammonium sulfate aqueous solution (1 mol / l) with stirring and reacted for 30 minutes. After completion of the reaction, filtration, washing with water and drying (110 ° C., 24 hours) were carried out to obtain a microcapsule-shaped photocatalyst body containing titanium oxide and having a wall made of silica and having an average particle diameter of 5 μm.

Example 5 Instead of 4 g of titanium oxide / tin oxide mixed powder, titanium oxide (manufactured by Wako Pure Chemical Industries, anatase type, primary particle size 0.3 μm)
m) In the same manner as in Example 4 except that 4 g was used, a microcapsule-shaped photocatalyst body having a wall of silica and an average particle size of 7 μm was obtained by encapsulating titanium oxide.

Example 6 In the same manner as in Example 4 except that 4 g of tungsten oxide (manufactured by Wako Pure Chemical Industries, Ltd.) was used in place of 4 g of the titanium oxide / tin oxide mixed powder, silica was encapsulated with tungsten oxide. A microcapsule-shaped photocatalyst having an average particle diameter of 12 μm having a wall made of

Example 7 Strontium titanate (manufactured by Wako Pure Chemical Industries, Ltd.) 4 was used in place of 4 g of titanium oxide / antimony oxide-containing tin oxide mixed powder.
In the same manner as in Example 4 except that g was used, a microcapsule-shaped photocatalyst body containing strontium titanate and having a silica wall and an average particle size of 9 μm was obtained.

Example 8 5 g of titanium oxide / tin oxide mixed powder was added to 50 ml of an aqueous sodium silicate solution (2 mol / l in terms of silicon dioxide) and stirred for 20 minutes to prepare a uniform suspension. The above suspension was added to 150 ml of a benzene solution of sorbitan monostearate (3% by weight) and emulsified with an emulsifying machine for 5 minutes to prepare a W / O type emulsion. Next, 450 ml of the above emulsion was added to an aqueous solution of calcium chloride (1.5 mol / l).
It was added to the mixture with stirring, and the mixture was reacted for 1 hour. After completion of the reaction, filtration, washing with water, and drying (110 ° C., 24 hours) were carried out to obtain a microcapsule-shaped photocatalyst body containing titanium oxide and having a wall made of silica and having an average particle diameter of 3 μm.

Example 9 Titanium oxide / tin oxide mixed powder was suspended in methanol to form a slurry, and a silicone oil for powder treatment (manufactured by Shin-Etsu Chemical Co., Ltd., AFP-1) was used in an amount of 1% by weight based on the powder. Lipophilic treatment was carried out. 8 g of a powder obtained by drying and crushing this was suspended in 10 ml of a benzene solution of polyoxyethylene sorbitan monooleate (2% by weight) to obtain a suspension. Next, this suspension was added to 70 ml of a water glass aqueous solution (4 mol / l in terms of silicon dioxide) and dispersed for 1 minute with a homogenizer to prepare an O / W type emulsion. Thereafter, the obtained emulsion was added to 150 ml of a benzene solution of sorbitan monostearate (3% by weight), and then shaken for 5 minutes using a shaker to give (O /
A W) / O type emulsion was prepared. Next, the above emulsion oil was added to an aqueous solution of ammonium sulfate (1.5 mol / l) (500 ml).
It was added to the mixture with stirring, and the mixture was reacted for 30 minutes. After completion of the reaction, filtration, washing with water and drying (110 ° C., 24 hours),
A spherical composite powder containing titanium oxide and having a silica wall and an average particle size of 6 μm was obtained.

Example 10 Instead of the titanium oxide / tin oxide mixed powder, titanium oxide (manufactured by Wako Pure Chemical Industries, anatase type, primary particle size 0.3 μm)
Lipophilic treatment as in Example 4, except that
An operation such as emulsification was performed to encapsulate titanium oxide to obtain a microcapsule-shaped photocatalyst body having a wall made of silica and having an average particle diameter of 7 μm.

Example 11 Titanium oxide (manufactured by Ishihara Sangyo Co., anatase type, primary particle size 7
nm) 9 parts by weight and 1 part by weight of antimony oxide-containing tin oxide (“T-1” manufactured by Mitsubishi Materials Corporation, particle size 0.02 μm) (hereinafter referred to as “titanium oxide / tin oxide mixed powder”). Silicone oil for powder treatment (made by Shin-Etsu Chemical Co., Ltd.)
AFP-1) was added to the powder in an amount of 2% by weight to perform a lipophilic treatment. 6 g of powder obtained by drying and crushing this was suspended in 10 ml of toluene to obtain a suspension. Next, the above suspension was treated with a 1 wt% polyoxyethylene sorbitan monooleate water glass aqueous solution (2 mol / l as silicon dioxide).
After adding to 70 ml, the mixture was dispersed for 1 minute with a homogenizer to prepare an O / W type emulsion. Then, the obtained emulsion was added to a sorbitan monostearate solution in toluene (2
(Wt%) was added to 150 ml and shaken for 5 minutes with a shaker to prepare an (O / W) / O type emulsion. Next, the above emulsion was treated with an aqueous solution of calcium chloride (2 mol / l) 5
The mixture was added to 00 ml with stirring and reacted for 30 minutes. After completion of the reaction, filtration, washing with water, and drying at 110 ° C. for 24 hours were performed to obtain a microcapsule-shaped photocatalyst body containing titanium oxide and having a wall made of silica and having an average particle diameter of 2 μm.

Example 12 Montmorillonite ("Kunipia F" manufactured by Kunimine Industries Co., Ltd.,
Cation exchange amount: 110 meq / 100 g) 100 g was dispersed in water to form a slurry, and dioctadecyl ammonium chloride aqueous solution (0.12 mol / l) was added to the montmorillonite for organic treatment while stirring using a dissolver. gave. 4 g of the titanium oxide / tin oxide mixed powder was added to 50 ml of an aqueous sodium silicate solution (4 mol / l in terms of silicon dioxide) and stirred for 10 minutes to prepare a uniform suspension. The above suspension was treated with an organically treated montmorillonite benzene solution (1% by weight)
It was added to 50 ml and shaken for 1 minute using a shaker to prepare a W / O type emulsion. Next, the above emulsion was added to 500 ml of an ammonium sulfate aqueous solution (1 mol / l) with stirring and reacted for 30 minutes. After completion of the reaction, the mixture is filtered, washed with water and dried (110 ° C., 24 hours) to contain titanium oxide and have a silica-made wall having an average particle size of 4
A microcapsule photocatalyst having a size of μm was obtained.

Example 13 Titanium oxide / tin oxide mixed powder was suspended in methanol to form a slurry, and 2% by weight of powder-treating silicone oil (AFP-1 manufactured by Shin-Etsu Chemical Co., Ltd.) was added to the powder. And subjected to lipophilic treatment. 10 g of the powder obtained by drying and crushing this was suspended in 20 ml of toluene to obtain a suspension. Next, the above suspension was put into 70 ml of an aqueous solution of water glass (2 mol / l in terms of silicon dioxide) containing 1% by weight of a clay mineral (manufactured by Nissan Gardler Catalyst Co., Ltd., OPTIGEL WA, which is partially organically treated). After the addition, the mixture was dispersed for 1 minute with a homogenizer to prepare an O / W type emulsion.
Then, the obtained emulsion was added to 150 ml of a toluene solution of sorbitan monostearate (2% by weight), and the mixture was shaken with a shaker for 5 minutes to give an (O / W) / O type emulsion. Was prepared. Next, the above emulsion was added to 500 ml of an aqueous calcium chloride solution (2 mol / l) with stirring and reacted for 30 minutes. After completion of the reaction, filtration, washing with water, 1
It was dried at 10 ° C. for 24 hours to obtain a microcapsule-shaped photocatalyst body containing titanium oxide and having a wall made of silica and having an average particle diameter of 2 μm.

Example 14 5 g of titanium oxide / tin oxide mixed powder was added to 50 ml of an aqueous sodium silicate solution (4 mol / l in terms of silicon dioxide) and stirred for 10 minutes to prepare a uniform suspension. The above suspension was added to 150 ml of a benzene solution of sorbitan monostearate (1% by weight) and emulsified with an emulsifier for 5 minutes to prepare a W / O type emulsion. Next, the above emulsion was added to 500 ml of an ammonium sulfate aqueous solution (1 mol / l) with stirring and reacted for 30 minutes. After completion of the reaction, filtration, washing with water, and drying (110 ° C., 24 hours) were carried out to obtain a microcapsule-shaped photocatalyst body containing titanium oxide and having a wall made of silica and having an average particle diameter of 1 μm. further,
12 g of the microcapsule-shaped photocatalyst is 50 m in aqueous sodium silicate solution (4 mol / l in terms of silicon dioxide)
1 and stirred for 10 minutes to prepare a uniform suspension. The above suspension was added to 150 ml of a benzene solution of sorbitan monostearate (1% by weight) and shaken with a shaker for 5 minutes to prepare a W / O type emulsion. Next, the above emulsion was mixed with an ammonium sulfate aqueous solution (1 mol / l) 5
The mixture was added to 00 ml with stirring and reacted for 30 minutes. After completion of the reaction, filtration, washing with water, and drying (110 ° C., 24 hours) were carried out to obtain a microcapsule-shaped photocatalyst body containing titanium oxide and having a wall made of silica and having an average particle diameter of 12 μm.

Comparative Example 1 Instead of the microcapsule-shaped photocatalyst of Example 1, titanium oxide (manufactured by Wako Pure Chemical Industries, anatase type, primary particle size 0.3) was used.
μm) powder was used as is.

Comparative Example 2 4 g of the titanium oxide / tin oxide mixed powder was suspended in 36 g of water to form a slurry, and then an aqueous solution in which 0.1 g of aluminum chloride was dissolved was added. While gently stirring this mixed solution, an aqueous solution of sodium hydroxide was slowly added dropwise for neutralization to deposit aluminum hydroxide on the surface of the mixed powder in the slurry. Then, the precipitate is filtered and dried,
The powder was pulverized to obtain a powder whose surface was coated with alumina.

<Molded Body> The amount of the microcapsule-shaped photocatalyst body obtained in the above example and the powder obtained in the comparative example in unsaturated polyester (“V-262G” manufactured by Mitsui Toatsu Chemicals, Inc.) is shown in Table 1. And were dispersed for 2 hours using a disperser.
Further, 4 parts by weight of a methyl ethyl ketone peroxide 55% by weight dimethyl phthalate solution as a thermal polymerization initiator and 2 parts by weight of cobalt naphthenate (metal content 6% by weight) as a curing accelerator were added and mixed. This composition was applied to an FRP mold for trial production of a flat plate sample, which had been previously treated with a release agent, to a thickness of about 200 μm, and once at 80 ° C.
Cured for 5 minutes. After cooling, a resin solution prepared by adding 55% by weight MEKP dimethyl phthalate solution to an unsaturated polyester resin similar to the above on the obtained coating was mixed and poured into the mold, and after curing, the mold was released from the FRP mold. A molded product having a polyester resin layer containing the microcapsule photocatalyst or the powder of the comparative example was obtained.

The molded products were evaluated for antibacterial properties, antifungal properties, and weather resistance, and the powders of Example 1 and Comparative Examples 1 and 2 were evaluated for gas decomposability by the following methods.
Table 1 shows the results.

[0064]

[Table 1]

<Evaluation of Antibacterial Property> The molded bodies produced in Examples and Comparative Examples were placed in a sterilized petri dish, and a test bacterial solution (Heart Infusion Broth medium (hereinafter, BHI medium, manufactured by DIFCO, 25 g / l) was placed thereon. ) Was diluted 100 times with physiological saline, and 1 ×
10 7 CFU / ml) was dispensed and the lid was closed. Seal the petri dish and turn on the fluorescent lamp for 3
After culturing at 0 ° C. for 1 day, the viable cell count of the test bacterium after culturing was measured by an ordinary colony counting method.

<Evaluation of antifungal properties> Molds and yeasts previously cultivated on potato dextrose agar medium (hereinafter referred to as PDA medium, manufactured by Nissui Pharmaceutical Co., Ltd.) were scraped off with a platinum loop, and 0.05% Tween80-added physiology was added. The mixture was placed in saline, dispersed and stirred, and then filtered using a glass filter. The obtained filtrate was centrifuged at 10,000 rpm for 15 minutes to remove the supernatant liquid to obtain a precipitate (spores). In addition to this, potato dextrose liquid medium (hereinafter PDB
A spore suspension was prepared by adding an appropriate amount of medium, manufactured by DIFCO.

After sterilizing the PDA medium by autoclave, it was incubated at 45 ° C. so that the agar did not solidify, and the above spore suspension was added to 1/10 volume of the PDA medium and stirred. The molded bodies produced in Examples and Comparative Examples were placed in a sterilized petri dish, and 50 μl of the spore suspension-containing PDA medium was added dropwise to each to solidify into a hemisphere. After the petri dish was sealed and cultured at 30 ° C. for 3 to 5 days under lighting of a fluorescent lamp, the growth of the bacteria was visually determined. ○ Growth of test bacterium is not observed × Growth of test bacterium is recognized

<Evaluation of weather resistance> An accelerated weather resistance test was conducted using a test device using a sunshine carbon arc lamp specified in JIS-A1415, and the color difference of the plate after irradiation for 200 hours was measured by a color difference meter (Tokyo Denshoku Co., Ltd.). (Manufactured by Color Analyzer TC-1800MK), and the absolute value of the color difference changed from before the test is shown. Further, the surface of the plate after the test was lightly rubbed with a finger to observe the presence or absence of chalking. ○ No chalking allowed × Choking allowed

<Evaluation of Gas Decomposability> A microcapsule-shaped photocatalyst of Example 1 and powders of Comparative Examples 1 and 2 suspended in water to form a slurry were used as a cylindrical glass column having a roughened inner surface. (Inner diameter: 3 cm, length 30 cm) was applied and dried to obtain a glass column having an inner surface carrying a photo-semiconductive powder. Four plaque light blue fluorescent lamps (10 W) were installed at a distance of 5 cm around this column tube, and the concentration was 10 p
A test gas of pm was passed through the column at a speed of 50 ml / min, and the concentration of the test gas after passing through the column was measured. As the test gas, two kinds of nitrogen dioxide and acetaldehyde (a substance causing an offensive odor) were used.

The reduction rate of the test gas was calculated by the following formula. Reduction rate of test gas (%) = [1- (test gas concentration after passage / test gas concentration before passage)] × 100 (%) From the results shown in Table 1, a photocatalyst body coated with a porous substance Was confirmed to be superior in the removal performance of these gases as compared with the case where the photo-semiconductor is used as it is.

[0071]

The porous microcapsule-like photocatalyst of the present invention contains a photo-semiconductive substance, and the photo-semiconductor substance is not exposed or the amount of the photo-semiconductor is exposed on the surface of the microcapsule. However, most of the short-lived components such as hydroxy radicals generated by irradiation of light on the porous microcapsule-shaped photocatalyst body before the passage through the microcapsule wall are present as compared to the encapsulation amount. It is speculated that the long-lived components such as hydrogen peroxide permeate outside the microcapsules and act.

Therefore, it is possible to impart the antibacterial performance to the article while preventing the deterioration of the constituent components of the base material which is considered to be caused by the above-mentioned single life component. In particular, (A
According to the method for preparing a 1 / B) / A2 type emulsion, it is possible to obtain a porous microcapsule-like photocatalyst in which the photo-semiconductor is hardly exposed on the surface. Also, A / B
In any of the methods for preparing emulsions of type A and type (A1 / B) / A2, the inclusion rate can be improved by using a clay mineral as an emulsifying dispersant during preparation of the emulsion. Further, the catalytic effect is improved by including a small amount of a conductive substance together with the photo-semiconductor substance.

According to the present invention, the components constituting the base material to which the photocatalytic action is imparted can be selected without being restricted by the deterioration. Therefore, the antibacterial and antifungal treatment, the sterilization treatment and the environmental pollutants can be performed. , Decomposition and removal of substances that cause offensive odors,
It is advantageous when used in any field such as photolysis of water and catalyst.

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Claims (11)

[Claims] 1. A porous microcapsule photocatalyst body containing a photo-semiconductor and having a wall made of a porous substance. 2. The porous microcapsule-like photocatalyst body according to claim 1, wherein the photo-semiconductor is at least one selected from the group consisting of titanium dioxide, tungsten trioxide and strontium titanate. 3. The porous microcapsule-shaped photocatalyst body according to claim 1 or 2, which contains a conductive substance together with the photo-semiconductive substance. 4. The porous microcapsule-shaped photocatalyst body according to claim 1, wherein the conductive substance is tin oxide. 5. A solvent B, which is incompatible with the solvent A, is used, and the solvent A contains a photo-semiconductor and a component constituting a wall of a porous microcapsule by curing or solidifying, After the preparation of the B-type emulsion, the wall constituents are hardened or solidified.
5. The method for producing a porous microcapsule-shaped photocatalyst body according to any one of 1 to 4. 6. The wall of the porous microcapsule is prepared by using a solvent B which is incompatible with the solvents A1, A2 and A1, A2, and by allowing the solvent A1 to contain a photo-semiconductor and curing or solidifying the solvent B. Including the constituent components, (A1
/ B) / A2 type emulsion is prepared, and then the wall constituents are hardened or solidified, The method for producing a porous microcapsule photocatalyst according to any one of claims 1 to 4, . 7. The porous microcapsule form according to claim 6, wherein an inorganic photosemiconductive substance is subjected to lipophilic treatment and used to prepare a (A1 / B) / A2 type emulsion. Photocatalyst production method. 8. The method for producing a porous microcapsule-like photocatalyst body according to claim 5, wherein an emulsion is prepared by using a clay mineral as an emulsifying dispersant. 9. At least one selected from the group consisting of polyolefin resin, polyurethane resin, polyester resin, poly (meth) acrylic resin, polyamide resin, vinyl compound (co) polymer, formaldehyde resin, allyl resin and epoxy resin. Is used as a matrix component, and the porous microcapsule-shaped photocatalyst body according to any one of claims 1 to 4 is contained. 10. An antibacterial function comprising the porous microcapsule-shaped photocatalyst body according to any one of claims 1 to 4, wherein the porous microcapsule-shaped photocatalyst body is fixed in a state where at least a part of the porous microcapsule-shaped photocatalyst body is exposed on the surface. An article having. 11. The nitrogen oxide is decomposed by bringing the gas containing nitrogen oxide into contact with the porous microcapsule-shaped photocatalyst according to any one of claims 1 to 4. Method for removing nitrogen oxides.