JP6902973B2 - Photocatalyst-supported magnetic material using coating material and water purification method using it - Google Patents

Description

The present invention relates to a coating material, a photocatalyst-supported magnetic material using the same, and a method for producing the same. More specifically, the present invention comprises a coating material capable of forming a coating film having high wear resistance and high durability, a photocatalyst-supporting magnetic material having a core-shell structure using the material, and a magnetic material-containing core layer. It is contained by a shell layer containing at least a component having a siloxane unit, a photocatalyst and a metal particle or a metal compound particle having a larger primary particle size than the photocatalyst, so that a part of the surface of the photocatalyst and the metal particle or the metal compound particle is exposed. The present invention relates to a photocatalyst-supported magnetic material, which is contained in the shell layer, a method for producing the same, and a method for purifying water using the photocatalyst-supported magnetic material.

Decomposition of harmful substances in the air using titanium oxide as a photocatalyst (air purification), decomposition of malodor-causing substances (deodorization), decomposition of pollutants dissolved or dispersed in water (purification), decomposition and growth suppression of fungi ( Antibacterial) and suppression of dirt on outer walls and windows (antifouling) have been researched and developed. For example, for the purification of pollutants dissolved or dispersed in water, composite materials are being studied by various methods in order to increase the degree of purification.

Japanese Patent Application Laid-Open No. 03950923 uses an iron-titanium oxide-supporting catalyst compounded by blending an iron component with a titanium oxide-based photocatalyst, and uses organic suspensions, pesticides, and the environment contained in water to be treated containing suspended solids. A water purification method that adsorbs, decomposes, and precipitates impurities such as hormones to quickly purify the water to be treated in a short time, a water purification agent containing the above iron / titanium oxide-supporting catalyst as an active ingredient, and the like. It is about a water purification system.
However, since iron is exposed on the surface of this iron / titanium oxide-supported catalyst body and no rust preventive measures are actively taken, the exposed iron is oxidized in water to cause rust and is used continuously for a long period of time. There was a problem that it could not be recycled.

Japanese Patent No. 04551723 relates to a photocatalytic material in which a photocatalytic material is integrated with a magnetic material into an alloy and the alloy is made into a fine powder. The present invention relates to a waste treatment method for decomposing impurities contained in the waste to be treated by mixing the waste with the waste to be treated and activating it by irradiating it with ultraviolet rays.
However, since the magnetic material is exposed on the surface of this photocatalyst material and rust prevention measures are not actively taken, there is a problem that rust occurs in water and it cannot be used continuously for a long period of time or recycled.

Japanese Patent Application Laid-Open No. 05033411 is a photocatalyst resin composite particle in which fine particles inert to the photocatalyst and a photocatalyst are composited with resin particles as a base material as a photocatalyst, and the photocatalyst is formed on the surface of resin particles having a particle size of 0.01 to 10 mm. Fine particles that are inert and have a particle size smaller than the resin particles are fixed and composited one or more, and photocatalyst fine particles whose particle size is smaller than the resin particles are fixed and composited on the surface thereof.
However, since this photocatalyst material is a fixed composite of photocatalyst fine particles and does not contain an adhesive binder component that positively prevents detachment, the photocatalyst fine particles are detached and used continuously for a long period of time and recycled, especially when used in water. There was a problem that it could not be used.

Japanese Patent No. 03950923 Japanese Patent No. 04551723 Japanese Patent No. 05033411

An object of the present invention is to provide a coating material capable of forming a coating film having high wear resistance and high durability.
On the other hand, since the particles having a photocatalytic function (antase-type titanium oxide or the like) have a particle size on the order of nanometers, a method of immobilizing them on a base material is considered.

When the environment of use is water and the target substance is decomposed by using the photocatalytic function, the following problems must be addressed.
-The base material supported by the photocatalyst should not be desorbed or flowed out due to decay or rust.
-Easy separation and recovery of particles with photocatalytic function.
-Particles with a photocatalytic function can efficiently decompose the substance to be decomposed.
-Particles with photocatalytic function have excellent wear resistance and impact resistance, high durability, and the photocatalyst does not separate or flow out from the base material.

Therefore, the present invention has been made in view of such a problem, and is excellent in wear resistance and impact resistance, has high durability, can efficiently contact a substance to be decomposed, and can provide the catalyst. It is an object of the present invention to provide a photocatalyst and a method for producing the photocatalyst, which is difficult to be detached / flowed out from the supported substrate and can be easily separated / recovered.

As a result of various studies to achieve the above object, the present inventor has developed a coating material containing at least a component having a siloxane unit, a photocatalyst, and a metal particle or a metal compound particle having a larger primary particle size than the photocatalyst. The material-containing core layer is contained by a shell layer containing at least a component having a siloxane unit, a photocatalyst, and a metal particle or a metal compound particle having a larger primary particle size than the photocatalyst, and is contained on the surface of the photocatalyst and the metal particle or the metal compound particle. The present invention has been completed by finding that the above problems can be solved by using a photocatalyst-supported magnetic material characterized in that a part of the metal is contained in the shell layer so as to be exposed.

Thus, according to the present invention, there is provided a coating material characterized by containing at least a component having a siloxane unit, a photocatalyst, and metal particles or metal compound particles having a primary particle size larger than that of the photocatalyst.

Further, according to the present invention, the coating material is provided in which the component having the siloxane unit contains at least an organopolysiloxane.

The present invention also provides the coating material, wherein the metal particles or metal compound particles contain at least one selected from copper, zinc or silver.

Further, according to the present invention, the coating material is provided as the coating material for preparing a photocatalyst.

Further, according to the present invention, a photocatalyst-supporting magnetic material having a core-shell structure composed of a core layer and a shell layer containing the core layer, wherein the core layer contains a magnetic material and the shell layer has a siloxane unit. And the photocatalyst and the coating material containing at least metal particles or metal compound particles having a larger primary particle size than the photocatalyst, so that the shell layer exposes the photocatalyst and a part of the surface of the metal particles or metal compound particles. Provided is a photocatalyst-supported magnetic material characterized by containing.

Further, according to the present invention, the photocatalyst-supported magnetic material in which the magnetic material is ferrite is provided.

Furthermore, according to the present invention, the present invention comprises a purification step of dispersing the photocatalyst-supporting magnetic material in water, irradiating it with light to activate the photocatalyst, and decomposing organic substances existing in the water. A method of purifying water is provided.

Further, according to the present invention, there is provided a method for purifying the above-mentioned water in which the above-mentioned water is water of a domestic or factory wastewater reservoir.

Further, according to the present invention, there is provided a method for purifying water, which comprises a step of moving or recovering the photocatalyst-supported magnetic material using a magnet.

Further, according to the present invention, there is provided a method for purifying water, wherein the photocatalyst-supported magnetic material is subjected to a washing and drying step.

Moreover, according to the present invention, the method for purifying water is obtained in which the photocatalyst-supported magnetic material is regenerated by a washing and drying step and reused in the purifying step.

The coating material according to the present invention has excellent wear resistance and impact resistance, and can form a highly durable coating film.
Further, in the photocatalyst-supporting magnetic material having a core-shell structure according to the present invention, the surface of the core layer containing a magnetic material contains at least a component having a siloxane unit, a photocatalyst, and metal particles or metal compound particles having a larger primary particle diameter than the photocatalyst. Since it is coated with a shell layer, the photocatalyst is less likely to be separated or flow out from the photocatalyst-supported magnetic material even under various environments, even when shaken or impacted, and can be used for a long period of time, and can be easily separated and recovered.

Further, according to the present invention, when the photocatalyst is titanium oxide, tungsten oxide, or both, the photocatalyst can be efficiently activated according to various light source wavelengths, and the effect of decomposing target substances and organic substances can be exhibited. Become.
Further, according to the present invention, since the metal or the metal compound contains at least one selected from copper, zinc or silver, it is resistant to shaking and impact, and has a decomposing effect of a target substance and an organic substance together with a photocatalyst. Will be able to be demonstrated.

Further, according to the present invention, the photocatalyst-supported magnetic material is formed by dispersing the photocatalyst-supported magnetic material in water and irradiating it with light having a wavelength that activates the photocatalyst to decompose organic substances existing in the water. Since it is possible to promote the decomposition reaction of organic substances existing in the water on the surface of each photocatalyst-supporting magnetic particle while being dispersed in water, the decomposition effect of the photocatalyst can be exhibited particularly in the purification of water. ..

Further, according to the present invention, the photocatalyst-supported magnetic material according to the present invention used for purifying water using a magnet is quantitatively recovered by a movement or recovery step, whereby the photocatalyst-supported magnetic material leaks to the usage environment. It is possible to reduce the maintenance cost because the recovered photocatalyst-supporting magnetic material can be washed with water, dried, and used semi-permanently in water purification.

It is the schematic sectional drawing of the photocatalyst-supporting magnetic material of this invention. It is a schematic of the manufacturing flow which shows the manufacturing process of the photocatalyst-supporting magnetic material of this invention.

Coating Material The coating material of the present invention can provide a coating material capable of forming a coating film having excellent wear resistance and impact resistance, high durability, high wear resistance, and high durability, and is a component having a siloxane unit. It is characterized by containing at least a photocatalyst and metal particles or metal compound particles having a larger primary particle size than the photocatalyst.

Photocatalyst-supported magnetic material The photocatalyst-supported magnetic material of the present invention is a photocatalyst-supported magnetic material having a core-shell structure, in which the core layer containing a magnetic material contains a component having a siloxane unit, a photocatalyst, and metal particles having a larger primary particle diameter than the photocatalyst. Alternatively, it is contained by a shell layer containing at least metal compound particles, and has a structure contained in the shell layer so that a photocatalyst and a part of the surface of the metal particles or metal compound particles are exposed.

According to the photocatalyst-supported magnetic material of the present invention, the shell layer having a siloxane structure acts as a protective layer, which prevents rusting of magnetic particles and suppresses adsorption to the surface of magnetic particles, and is used for water purification. Excellent durability. Further, it is said that a part of the metal particles or metal compound particles that absorb the impact when the photocatalyst having a photocatalytic function and the outside or the catalysts come into contact with each other is buried in the shell layer having a siloxane structure without being exposed. The function cannot be demonstrated.
As used in the present invention, the shell layer contains the photocatalyst so that a part of the surface of the metal particles or the metal compound particles is exposed, that is, a part of the photocatalyst particles having a photocatalytic function is in contact with the outside or the catalysts. In some cases, it means that a part of the metal particles or metal compound particles that absorb the impact is exposed on the outermost surface of the shell layer having a siloxane structure.

When light with an energy equal to or greater than the energy gap between the valence band and the conduction band of various semiconductors is irradiated, the electrons in the valence band are excited to the conduction band, and holes are generated in the valence band. It is said that these electrons and holes move inside the semiconductor, the electrons reduce oxygen _{to generate superoxide anions (・ O 2} ⁻ ), and the holes oxidize water to generate hydroxyl radicals (・ OH). ing. It is said that active oxygen species are produced based on these radical groups. It is known that organic substances are decomposed and sterilized by this reactive oxygen species.

As a photocatalyst-supported magnetic material having such characteristics, those having titanium oxide, tungsten oxide or the like as a main composition are well known.
The titanium oxide is not particularly limited, and may be rutile-type titanium oxide, anatase-type titanium oxide, brookite-type titanium oxide, or a mixed crystal of two or more of these, and may be selected according to the intended use.
Further, the tungsten oxide is not particularly limited, and a commercially available product can be used as appropriate. Since a part of tungsten oxide may be reduced to V value, it is preferable to use it after oxidizing it to VI value by firing at a high temperature or the like. The crystal structure of tungsten oxide is also not particularly limited.

Structure of Photocatalyst-Supported Magnetic Material The photocatalyst-supported magnetic material having a core-shell structure will be described below.
FIG. 1 shows a photocatalyst-supporting magnetic material having a structure including a magnetic material-containing core layer, a component having a siloxane unit on the surface of the core layer, a photocatalyst, and a shell layer containing at least metal particles or metal compound particles.

Further, although not shown in FIG. 1, the shell layer does not have to completely cover the surface of the core layer, and even if a layer having another composition is inserted between the core layer and the shell layer, the shell layer is divided into two. It may be designed more than one layer.
By using the magnetic material-containing core layer, it becomes possible to control the dispersion and recovery of particles by magnetic force when the photocatalyst-supported magnetic material is used in water.
By recovering the photocatalyst-supported magnetic material, the photocatalyst-supported magnetic material can be easily recycled and can be used semi-permanently.

Core layer The core layer contains a magnetic material. The magnetic material is not particularly limited, and for example, oxides such as ferrite, magnetite, and iron oxide, metals such as iron, cobalt, and nickel, or alloys thereof can be used, and other main components and sub-components can be used. It may contain elements. Examples of the contained elements include iron, cobalt, nickel, aluminum, copper, lead, magnesium, tin, zinc, antimony, beryllium, bismuth, calcium, manganese, selenium, titanium, tungsten and vanadium.

The particle size of the core layer material is not particularly limited as long as it can be controlled and recovered by magnetic force, but is preferably in the range of 5 μm to 5 mm on average. When the particle size of the core layer material is within such a range, it is easy to handle the dispersibility in water, the recoverability from water, and the like, and it is easy to mix the core layer material into the shell layer.

Various materials that can be used as the core layer material and their manufacturing methods will be described.
Ferrite Ferrite is _{produced by mixing iron oxide Fe 2} O ₃ as a main component with oxides of other divalent metals and then heating to bond them, but it is produced by either a dry method or a wet method. You may. The dry method is a method in which a metal oxide or a raw material that decomposes into a metal oxide by heating is mixed, heated and bonded to each other.

The wet method is a method in which a water-soluble compound of a metal, which is a ferrite raw material, is mixed in water, and an alkali is added to this aqueous solution to precipitate a metal hydroxide, which is dehydrated and dried and then heated for production. ..

The main raw material, iron oxide, is a commercially available iron oxide component, and the auxiliary raw materials are transition metals such as zinc, nickel, copper, manganese, magnesium, and cobalt; alkaline earth metals such as strontium and barium; and rare earth metals such as yttrium, samarium, and gadrinium. Can be a commercially available oxide or a commercially available raw material such as manganese carbonate, which is easily converted into an oxide by heating, for example, in the case of manganese.

An example of production by the dry method will be described below, but the present invention is not limited to the following description.
The raw materials are weighed in appropriate amounts, mixed with a commercially available mixer and crusher, and then pulverized. Next, water, a dispersant, etc. are added to this mixture to make a slurry having a solid content concentration of 30 to 90% by weight. Next, in the granulation step, the slurry is sprayed into hot air with a spray dryer and dried to obtain a granulated product.
Next, the granulated product is heated at 1000 to 1300 ° C. to form ferrite. The obtained ferrite was used as a ferrite core by adjusting the particle size with a crusher and a classifier.

_{Magnetite Magnetite is mainly composed of triiron tetroxide Fe 3} O ₄ as a raw material, and may be produced by any of a generally known wet method, dry method, or pulverization method.

The wet method is a method in which ^{an aqueous solution of Fe 2+} + 2Fe ³⁺ is made alkaline and coprecipitated.

The dry method is a method of heating / reducing hematite (iron oxide Fe ₂ O ₃ ) in hydrogen / carbon monoxide or steam.

The crushing method is a method of crushing naturally occurring magnetite. Magnetite is generally produced by a wet method, and is obtained by oxidizing a solution containing iron hydroxide at a temperature of 60 ° C. or higher.
In this production method, since the magnetite particles produced by the reaction are obtained in a state of being dispersed in water, the magnetite particles can be separated and then dried to obtain a powder.

Specific examples of raw materials for producing iron hydroxide include ferrous chloride, ferrous sulfate, ferrous iodide, ferrous bromide, ferric chloride, ferric nitrate, and sulfuric acid. Secondary iron or the like can be used.

As the alkaline aqueous solution, a sodium hydroxide aqueous solution, a potassium hydroxide aqueous solution, a sodium carbonate aqueous solution, a potassium carbonate aqueous solution, or the like can be used. The oxidation of iron hydroxide is carried out by aerating an oxygen-containing gas (or air) through an aqueous solution containing iron hydroxide colloid while heating.

Photocatalyst The photocatalyst is not particularly limited, and is not particularly limited, such as titanium oxide (TIO ₂ ), tungsten oxide (WO ₃ ), strontium titanate (SrTIO ₃ ), niobium oxide (Nb ₂ O ₅ ), and tantalum oxide (Ta ₂ O ₅ ). , Zirconium oxide (ZrO ₂ ), bismuth oxide (Bi ₂ O ₃ ), iron oxide (Fe ₂ O ₃ ) and the like can be used.

Only one type of these photocatalysts may be used, or two or more types may be mixed and used.
Among these, those having titanium oxide or tungsten oxide as the main composition are preferable because they are inexpensive and easily available.

Further, a metal or a metal compound may be immobilized on the surface of the various photocatalysts as an auxiliary catalyst for reducing the energy gap and improving the responsiveness in the visible light region. In that case, it is preferable to add a transition metal as the metal of the metal or the metal compound. It is preferable to add platinum group metals such as platinum, palladium, rhodium, iridium, ruthenium and osmium.

The 50% volume cumulative diameter of the photocatalyst that can be used in the present invention is preferably 5 nm or more and 200 nm or less. When it is 5 nm or more, there is little agglutination and redispersion is easy. When it is 200 nm or less, it is easy to uniformly mix with other components in the processing step, and it is good that there is little detachment.
The particle size can be measured by a laser diffraction type particle size distribution meter, a dynamic light scattering type particle size distribution meter, or the like.

Metal particles or metal compound particles The metal particles or metal compound particles are not particularly limited as long as they are materials having a primary particle diameter larger than that of the photocatalyst. Alternatively, the metal compound particles preferentially play a role of absorbing impact. Further, unlike resin particles made of organic polymers, metal particles and metal compound particles are durable because they are not decomposed by a photocatalyst. Any of the metal elements listed in the Periodic Table of the Elements can be used, but those containing the metal elements of Groups 10, 11 and 12 of the Periodic Table are preferable in terms of antibacterial performance, and are composed of silver, zinc and copper. One or more metal particles or metal compound particles selected from the group are particularly preferable. When such a metal element is used, a synergistic effect with the decomposition of the target substance or organic substance by the photocatalyst becomes possible.

In addition, other organic compounds having an algae-proofing effect can also be used. For example, organic nitrogen-sulfur compounds, pyrithion compounds, organic iodine compounds, triazine compounds, isothiazoline compounds, imidazole compounds, and pyridine compounds can be used. , Nitrigen-based compounds, thiocarbamate-based compounds, thiazole-based compounds, disulfide-based compounds and the like.

Component having a siloxane unit By providing a component having a siloxane unit on the surface of the core layer, it is possible to prevent a wide variety of components from being adsorbed on the magnetic material and remaining without being decomposed. Furthermore, it is possible to prevent the occurrence and progression of rust in the core containing the magnetic material. Since the component having a siloxane unit has lower adsorptivity to a wide variety of materials than the photocatalyst, the target organic substance to be decomposed can be brought into contact with the photocatalyst preferentially, so that the decomposition reaction by the photocatalyst proceeds efficiently. It becomes possible to make it. Further, the compound having a siloxane unit is strong against light and heat, the photocatalyst existing together with the component having a siloxane unit can be stably immobilized, and the photocatalyst-supported magnetic material can be recycled.

Examples of the component containing the component having the siloxane unit include organopolysiloxane and glass, and any of them can be used. As for the organopolysiloxane, in addition to the silicone resin, a silicone rubber having rubber elasticity at room temperature, a modified silicone resin or a modified silicone rubber having various organic functional groups introduced therein, or a silane coupling agent may be used.

As the crosslinked silicone resin, either a heat-curable silicone resin or a room temperature curable silicone resin can be used. To crosslink the heat-curable silicone, the resin is heated to about 200 to 250 ° C. Further, in order to cure the room temperature curable silicone, it is possible to cure it at room temperature, and although heating is not required, it may be heated at 150 to 280 ° C. in order to shorten the curing time.

Among the crosslinked silicone resins, those in which the monovalent organic group represented by R is a methyl group are preferable. This crosslinked silicone has a dense crosslinked structure, and when a shell layer is formed on a magnetic material-containing core layer using the crosslinked silicone, a photocatalyst-supported magnetic material having good water repellency and moisture resistance can be obtained. However, if the crosslinked structure becomes too dense, the resin layer tends to become brittle, so it is important to study the crosslinked silicone cured state.

Examples of commercially available crosslinked silicone resins include product names manufactured by Toray Dow Corning Co., Ltd .: BA2400, BA2410, BA2411, BA2510, BA2405, 840RESIN, 804RESIN, and product names manufactured by Shin-Etsu Chemical Co., Ltd .: KR350, KR271, KR272. , KR274, KR216, KR280, KR282, KR261, KR260, KR255, KR266, KR251, KR155, KR152, KR214, KR220, X-4040-171, KR201, KR5202, KR3093 and the like.
As the crosslinked silicone resin, one type may be used alone, two or more types may be used in combination, or glass may be used in combination.

Further, the shell layer containing the component having a siloxane unit according to the present invention may contain another resin. Such resins are not limited as long as they do not impair the preferable properties of the shell layer, but for example, epoxy resin, urethane resin, phenol resin, acrylic resin, styrene resin, polyamide, polyester, acetal resin, polycarbonate, vinyl chloride resin, etc. Examples thereof include vinyl acetate resins, cellulose resins, polyolefins, copolymer resins thereof, and compounded resins. In the case of glass, soda glass, crystal glass, borosilicate glass and the like can be mentioned.

Examples of the silicone rubber include addition type silicone rubber and silicone rubber film-forming emulsion.

Examples of the add-on silicone rubber include room temperature curable silicone rubber (RTV silicone rubber) and low temperature curable silicone rubber (LTV silicone rubber). Room-temperature curable silicone rubber (RTV silicone rubber) is a silicone rubber that is in the form of a liquid or paste before curing and becomes a rubber elastic body by the curing reaction proceeding at room temperature.

The room temperature curing type silicone rubber (RTV silicone rubber) is preferably a one-component RTV silicone rubber and a two-component RTV silicone rubber.
Examples of the one-component RTV silicone rubber include product names manufactured by Shin-Etsu Chemical Co., Ltd.: KE-3423, KE-347, KE-3475, KE-3495, KE-4895, KE-4896, KE-1830, KE-1884, KE-3479, KE-348, KE-4897, KE-4898, KE-1820, KE-1825, KE-1831, KE-1833, KE-1885, KE-1056, KE-1151, KE- 1842, KE-1886, KE-3424G, KE-3494, KE-3490, KE-40RTV, KE-4890, KE-3497, KE-3298, KE-3494, KE-3466, KE-3467, KE-1862, KE-1867, KE-3491, KE-3492, KE-3417, KE-3418, KE-3427, KE-3428, KE-41, KE-42, KE-44, KE-45, KE-441, KE- 445, KE-45S and the like can be mentioned.

Examples of the two-component RTV silicone rubber include product names manufactured by Shin-Etsu Chemical Co., Ltd.: KE-1800T-A / B, KE-66, KE-1031-A / B, KE-200, KE-118, KE-103, KE-108, KE-119, KE-109E-A / B, KE-1051J-A / B, KE-1012-A / B, KE-106, KE-1282-A / B, KE- 1283-A / B, KE-1800-A / B / C, KE-1801-A / B / C, KE-1802-A / B / C, KE-1281-A / B, KE-1204-A / B, KE-1204-AL / BL, KE-1280-A / B, KE-513-A / B, KE-521-A / B, KE-1285-A / B, KE-1861-A / B, KE-12, KE-14, KE-17, KE-113, KE-24, KE-26, KE-1414, KE-1415, KE-1416, KE-1417, KE-1300T, KE-1310ST, KE- 1314-2, KE-1316, KE-1600, KE-1603-A / B, KE-1606, KE-1222-A / B, KE-1241, KEG-2000-40A / B, KEG-2000-50A / B, KEG-2000-60A / B, KEG-2000-70A / B, KEG-2001-40A / B, KEG-2001-50A / B, KE-1950-10A / B, KE-1950-20A / B, KE-1950-30A / B, KE-1950-35A / B, KE-1950-40A / B, KE-1950-50A / B, KE-1950-60A / B, KE-1950-70A / B, KE- 1935A / B, KE-1987A / B, KE-1988A / B, KE-2019-40A / B, KE-2019-50A / B, KE-2019-60A / B, KE-2017-30A / B, KE- 2017-40A / B, KE-2017-50A / B, KE-2090-40A / B, KE-2090-50A / B, KE-2090-60A / B, KE-2090-70A / B, KE-2096- Examples thereof include 40A / B, KE-2096-50A / B, and KE-2096-60A / B.

Examples of the silicone rubber film-forming emulsion include product names manufactured by Shin-Etsu Chemical Co., Ltd.: Polon MF-56, KM-2002L-1, KM-2002T, X-51-1318, X-52-1631, KM. -9749, Polon MF-40 and the like can be mentioned.

The silane coupling agent refers to one having a functional group C _j H _2j-1 O- (j is a positive integer) bonded to a silicon atom.
For example, n-propyltriethoxysilane, n-propyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxy. Silane, Methacryloxypropyltriethoxysilane, Methacryloxypropyltrimethoxysilane, N- (n-butyl) -3-aminopropyltriethoxysilane, Vinyltrimethoxysilane, N- (n-butyl) -3-aminopropyltri Methoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, N-2-aminoethyl-3-aminopropyltrimethoxysilane, polyethylene glycol functionalized alkoxysilane, tetraethoxysilane, tetramethoxysilane, methyl Triethoxysilane, methyltriethoxysilane, bis (triethoxysilylpropyl) tetrasulfan, bis (triethoxysilylpropyl) disulfan, bis (trimethoxysilylpropyl) disulfan, bis (trimethoxysilylpropyl) tetrasulfan, vinyl Triethoxysilane, 1-aminomethyltriethoxysilane, 1-aminomethyltrimethoxysilane, 1-methacryloxy-methyltrimethoxysilane 1-methacryloxymethyltriethoxysilane, 1-mercaptomethyl-triethoxysilane, 1-mercaptomethyl Trimethoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, octylriethoxysilane, octylrimethoxysilane, hexadecyltriethoxysilane, hexadecyltrimethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 2-aminoethyl -3-Aminopropyl-methyldimethoxysilane, 2-aminoethyl-3-aminopropylmethyldiethoxysilane, ureidopropyltrimethoxysilane, ureidopropyltriethoxysilane, tridecafluorooctylriethoxysilane, tridecafluorooctylrimethoxy Examples thereof include silane and a hydrolyzate obtained by preliminarily hydrolyzing these silane coupling agents.

Method for Producing Photocatalyst-Supported Magnetic Material The form of the shell layer when the magnetic material-containing core layer is mixed into the shell layer is not limited as long as the shell layer can contain the magnetic material-containing core layer. In the case of the structure, it may be in the form of a solution in which the resin which is a component of the shell layer is dissolved in a solvent, or in the form of a melt in which the resin which is a component of the shell layer is heated and melted.
As described above, when the constituent components of the shell layer are in a solution state or a molten state, the effect that the magnetic material-containing core layer can be easily contained is obtained.

In the case of a solution in which the above resin, which is a constituent of the shell layer, is dissolved in a solvent, any material other than the emulsion dispersed in water and the aqueous solution dissolved in water can be used as a solvent to dissolve the resin of the shell layer. There is no particular limitation.
When using an organic solvent, for example, aromatic hydrocarbons such as toluene and xylene; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran and dioxane; or alcohols such as 2-propanol, ethanol and methanol. It can be preferably used. The organic solvent may be used alone or as a mixed solvent of two or more.

Embodiment 1
Next, a method for producing a photocatalyst-supported magnetic material according to the present invention will be described.
According to the step shown in FIG. 2, a shell material containing at least a component having a siloxane unit, a photocatalyst, and metal particles or metal compound particles having a primary particle size larger than that of the photocatalyst is applied to the surface of the magnetic material-containing core layer, and then heated. The solvent is volatilized and removed, and dried to form a shell layer.
After that, in the cleaning step, the shell material or the like that was not formed in the magnetic material-containing core layer is cleaned so that it does not remain. Then, the photocatalyst-supported magnetic material can be produced by heat-drying or heat-curing and then recovering.

As a method of mixing the magnetic material-containing core layer into the shell layer, a known method can be adopted. For example, a dipping method in which the magnetic material-containing core layer is immersed in the shell material, a spray method in which the shell material is sprayed or dropped on the magnetic material-containing core layer, or a shell in which the magnetic material-containing layer is suspended by fluidized air. Examples thereof include a fluidized bed method in which a material is sprayed, and a kneader coater method in which a core layer containing a magnetic material and a shell material are mixed in a kneader coater to remove a solvent.

It is also one of the present inventions that the photocatalyst-supporting magnetic material according to the present invention can be used for purifying water including a purification step of dispersing it in water, irradiating it with light to activate the photocatalyst, and decomposing organic substances existing in the water. It is one of the characteristics. Further, the photocatalyst-supported magnetic material according to the present invention used for purifying water can be moved and recovered by using a magnet, then regenerated after undergoing a washing and / or drying step, and can be used again for purifying water. It is a feature of.
Examples of the water for purification treatment targeted by the water purification method include water from domestic, agricultural or industrial wastewater reservoirs.

The organic substances present in the water for purification treatment include diclobos (DDVP), binifate, langard, O-ethyl O-4-nitrophenylphenylphonothioate (EPN), and zip as organic phosphorus-based insecticides. Terex, Smition, Diazinone, Estocks, Dysiston, Marathon, Ecatin, Supraside, Ortran, etc.), Organic chlorine-based herbicides and pesticides (Chloroneb, DDVP, Hexachlorobenzene, Hexachlorocyclohexane (α-HCH, β-HCH), etc. ), Carbamate-based herbicides (thiobencarb mephenacet, etc.), diphenyl ether-based herbicides (chloronitrophenol, etc.), phenols (trichlorophenol, etc.), alkylphenols (4-t-butylphenol, 4-n-pentylphenol, 4-) n-hexylphenol, 4-heptylphenol, 4-t-octylphenol, 4-n-octylphenol, nonylphenol, etc.), and algae as plankton.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples.

Example 1
Production of photocatalyst-supported magnetic sample 1-1 Production of core layer (ferrite manganese) containing magnetic material As raw materials, ferric oxide Fe ₂ O ₃ (average particle size: 0.6 μm) 1.2 kg and trimanganese tetraoxide Mn ₃ 0.47 kg of O ₄ (average particle size: 0.9 μm) was added to 1.0 kg of a 1 wt% ammonium polycarboxylic acid aqueous solution to prepare a mixture. The obtained mixture was mixed and pulverized using a wet ball mill (media particle size 2 mm) to prepare a slurry of _{Fe 2} O ₃ and Mn ₃ O _4. The obtained slurry was dried using a spray dryer (hot air temperature 120 ° C.) to obtain a dry powder. The obtained dry powder was calcined at 1200 ° C. for 5 hours in a nitrogen atmosphere using an electric furnace. The obtained fired product was pulverized and then classified with a vibrating sieve to obtain a powder having a particle size of 50 μm. The obtained ferrite particles were held in a rotary kiln held at 500 ° C. for 1 hour, and the ferrite surface was subjected to an oxide film treatment to obtain 1.1 kg of ferrite manganese particles. The ferrite manganese particles were crushed, classified with a vibrating sieve, and the particle size was adjusted so that the average particle size was 35 μm.

Ingredients with siloxane units: 2 g of silicone (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KR-220LP), 10 g of titanium oxide (P25 primary particle size 21 nm manufactured by Nippon Aerosil Co., Ltd.) and copper sulfite (FRC manufactured by Furukawa Chemicals Co., Ltd. -05B Primary particle size 0.5 μm) 0.1 g and 2-propanol 10 g were dispersed at 50 μA for 5 minutes using a general-purpose ultrasonic homogenizer (ULTRASONIC GENERATOR, manufactured by Nissei Tokyo Office) to prepare a shell material solution. .. The obtained shell material liquid is added and mixed with 100 g of a magnetic material-containing core layer (ferrite manganese) having an average particle diameter of 35 μm, and further, using a stirrer (manufactured by AS ONE, Autocell Master CM-200) at a rotation speed of 10000 rpm. It was mixed for 10 minutes. The obtained powder was dried at 40 ° C. for 24 hours to remove 2-propanol, and then cured at a cure temperature of 200 ° C. and a cure time of 1 hour, and then sieved with an opening of 150 μm. After that, pure water is added and the above-mentioned general-purpose ultrasonic homogenizer is used to disperse and wash at 50 μA for 5 minutes, only the components adsorbed by a commercially available magnet are recovered, dried at 40 ° C., and sample 1-1. 110 g was obtained.

Example 2
Production of Photocatalyst-Supported Magnetic Sample 1-2 Ingredients with siloxane units: 2 g of silicone (manufactured by Shinetsu Chemical Co., Ltd., product name: KR-220LP) and 10 g of titanium oxide (P25 primary particle diameter 21 nm manufactured by Nippon Aerosil Co., Ltd.) Metallic copper (FMC-05C primary particle size 0.5 μm manufactured by Furukawa Chemicals Co., Ltd.) 0.1 g and 2-propanol 10 g were dispersed at 50 μA for 5 minutes using the general-purpose ultrasonic homogenizer described above, and the shell material liquid was used. Was prepared. The obtained shell material liquid was added and mixed with 100 g of a magnetic material-containing core layer (ferrite manganese) having an average particle diameter of 35 μm, and further mixed for 10 minutes at a rotation speed of 10000 rpm using the above-mentioned stirrer. The obtained powder was dried at 40 ° C. for 24 hours to remove 2-propanol, and then cured at a cure temperature of 200 ° C. and a cure time of 1 hour, and then sieved with an opening of 150 μm. After that, pure water is added and the above-mentioned general-purpose ultrasonic homogenizer is used to disperse and wash at 50 μA for 5 minutes, only the components adsorbed by a commercially available magnet are recovered, dried at 40 ° C., and sample 1-2. 110 g was obtained.

Example 3
Production of Photocatalyst-Supported Magnetic Sample 1-3 Ingredients with siloxane units: 2 g of silicone (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KR-220LP) and 10 g of titanium oxide (P25 primary particle diameter 21 nm manufactured by Nippon Aerozil Co., Ltd.) 0.1 g of zinc oxide (primary particle size 0.1 μm manufactured by Sigma Aldrich) and 10 g of 2-propanol were dispersed at 50 μA for 5 minutes using the above-mentioned general-purpose ultrasonic homogenizer to prepare a shell material solution. The obtained shell material liquid was added and mixed with 100 g of a magnetic material-containing core layer (ferrite manganese) having an average particle diameter of 35 μm, and further mixed for 10 minutes at a rotation speed of 10000 rpm using the above-mentioned stirrer. The obtained powder was dried at 40 ° C. for 24 hours to remove 2-propanol, and then cured at a cure temperature of 200 ° C. and a cure time of 1 hour, and then sieved with an opening of 150 μm. After that, pure water is added and the above-mentioned general-purpose ultrasonic homogenizer is used to disperse and wash at 50 μA for 5 minutes, only the components adsorbed by a commercially available magnet are recovered, dried at 40 ° C., and sample 1-3. 110 g was obtained.

Example 4
Production of Photocatalyst-Supported Magnetic Sample 1-4 Ingredients with siloxane units: 2 g of silicone (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KR-220LP) and 10 g of titanium oxide (P25 primary particle diameter 21 nm manufactured by Nippon Aerozil Co., Ltd.) A shell material liquid was prepared by dispersing 0.1 g of metallic silver (primary particle size 0.1 μm manufactured by Sigma Aldrich) and 10 g of 2-propanol at 50 μA for 5 minutes using the above-mentioned general-purpose ultrasonic homogenizer. The obtained shell material liquid was added and mixed with 100 g of a magnetic material-containing core layer (ferrite manganese) having an average particle diameter of 35 μm, and further mixed for 10 minutes at a rotation speed of 10000 rpm using the above-mentioned stirrer. The obtained powder was dried at 40 ° C. for 24 hours to remove 2-propanol, and then cured at a cure temperature of 200 ° C. and a cure time of 1 hour, and then sieved with an opening of 150 μm. After that, pure water is added and the above-mentioned general-purpose ultrasonic homogenizer is used to disperse and wash at 50 μA for 5 minutes, only the components adsorbed by a commercially available magnet are recovered, dried at 40 ° C., and sample 1-4. 110 g was obtained.

Comparative Example 1
Production of Comparative Sample 1 Ingredients having a siloxane unit: 2 g of silicone (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KR-220LP), 10 g of titanium oxide (P25 primary particle size 21 nm manufactured by Nippon Aerodil Co., Ltd.) and 10 g of 2-propanol. , The shell material liquid was prepared by dispersing at 50 μA for 5 minutes using the above-mentioned general-purpose ultrasonic homogenizer. The obtained shell material liquid was added and mixed with 100 g of a magnetic material-containing core layer (ferrite manganese) having an average particle diameter of 35 μm, and further mixed for 10 minutes at a rotation speed of 10000 rpm using the above-mentioned stirrer. The obtained powder was dried at 40 ° C. for 24 hours to remove 2-propanol, and then cured at a cure temperature of 200 ° C. and a cure time of 1 hour, and then sieved with an opening of 150 μm. After that, pure water is added and the above-mentioned general-purpose ultrasonic homogenizer is used to disperse and wash at 50 μA for 5 minutes, only the components adsorbed by a commercially available magnet are recovered, dried at 40 ° C., and the comparative sample 1 110 g. Got

Comparative Example 2
Production of Comparative Sample 2 2 g of silicone (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KR-220LP) and 10 g of 2-propanol, which have a siloxane unit, were dispersed at 50 μA for 5 minutes using the general-purpose ultrasonic homogenizer described above. The shell material liquid was prepared. The obtained shell material liquid was added and mixed with 100 g of a magnetic material-containing core layer (ferrite manganese) having an average particle diameter of 35 μm, and further mixed for 10 minutes at a rotation speed of 10000 rpm using the above-mentioned stirrer. The obtained powder was dried at 40 ° C. for 24 hours to remove 2-propanol, and then cured at a cure temperature of 200 ° C. and a cure time of 1 hour, and then sieved with an opening of 150 μm. After that, pure water is added and the above-mentioned general-purpose ultrasonic homogenizer is used to disperse and wash at 50 μA for 5 minutes, only the components adsorbed by a commercially available magnet are recovered, dried at 40 ° C., and the comparative sample 2 101 g. Got

Comparative Example 3
Production of Comparative Sample 3 Ingredients having a siloxane unit: 2 g of silicone (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KR-220LP) and cuprous oxide (FRC-05B primary particle diameter 0.5 μm manufactured by Furukawa Chemicals Co., Ltd.) 0. A shell material solution was prepared by dispersing 1 g and 10 g of 2-propanol at 50 μA for 5 minutes using a general-purpose ultrasonic homogenizer (ULTRASONIC GENERATOR manufactured by Nissei Tokyo Office). The obtained shell material liquid is added and mixed with 100 g of a magnetic material-containing core layer (ferrite manganese) having an average particle diameter of 35 μm, and further, using a stirrer (manufactured by AS ONE, Autocell Master CM-200) at a rotation speed of 10000 rpm. It was mixed for 10 minutes. The obtained powder was dried at 40 ° C. for 24 hours to remove 2-propanol, and then cured at a cure temperature of 200 ° C. and a cure time of 1 hour, and then sieved with an opening of 150 μm. After that, pure water is added and the above-mentioned general-purpose ultrasonic homogenizer is used to disperse and wash at 50 μA for 5 minutes, only the components adsorbed by a commercially available magnet are recovered, dried at 40 ° C., and the comparative sample 3 102 g. Got

Methylene blue decomposition test using a photocatalyst-supported magnetic material The methylene blue decomposition rate using a photocatalyst-supported magnetic material was measured in a glass container with 1 g of the photocatalyst-supported magnetic material samples of Examples 1 to 4 and Comparative Examples 1 to 3 and 20 μmol / L methylene blue trihydrate. 50 mL of a Japanese aqueous solution was added, and a 365 nm ultraviolet lamp was used to irradiate a ^{radiation illuminance of 2.5 mW / cm 2.} The supernatant was recovered from the sample after 24 hours, and the transmittance of the supernatant was measured in the wavelength region of 380 to 780 nm using a spectrophotometer (UV-2450, manufactured by Shimadzu Corporation). After the transmittance was measured, the supernatant was removed, and then 50 mL of a new 20 μmol / L methylene blue trihydrate aqueous solution was added, and the same test was repeated, for a total of 5 times. The transmittance of methylene blue at the absorption peak of 663 nm was measured for the supernatant after the first and fifth tests, and the resolution by the photocatalyst was obtained.

The evaluation of the methylene blue decomposition test using the photocatalyst-supported magnetic material was evaluated according to the following criteria, and the results are shown in Table 1. The first and fifth results are: A: Methylene blue transmittance is 70% or more and 100% or less B: Methylene blue transmittance is 20% or more and less than 70% C: Methylene blue transmittance is 0% or more and less than 20%

Durability test To measure the durability, put 2 g of the photocatalyst-supported magnetic material sample of Examples 1 to 4 and Comparative Examples 1 to 3 and 50 mL of water in a PP 50 mL container, and use a locking mill (Seiwa Giken, RM-01). As a result of shaking for 10 minutes each, the supernatant of the photocatalytic magnetic material dispersion liquid of Comparative Example 1 became cloudy in 60 minutes, and the process was completed. Only the photocatalyst-supported magnetic material sample was adsorbed by a magnet of 0.3 Tesla, washed with pure water, dried at 40 ° C., and then recovered.
1 g of the recovered photocatalyst-supported magnetic samples of Examples 1 to 4 and Comparative Examples 1 to 3 and 50 mL of a 20 μmol / L methylene blue trihydrate aqueous solution were placed in a glass container, and the irradiance was 2 with an ultraviolet lamp of 365 nm. It was irradiated with .5 mW / cm ^2. The supernatant was recovered from the sample after 24 hours, and the transmittance of the supernatant was measured in the wavelength region of 380 to 780 nm using a spectrophotometer (UV-2450, manufactured by Shimadzu Corporation). The transmittance of methylene blue at the absorption peak of 663 nm was measured to obtain photocatalytic resolution.

The evaluation of the methylene blue decomposition test using the photocatalyst-supported magnetic material was evaluated according to the following criteria, and the results are shown in Table 1.
A: Methylene blue transmittance is 70% or more and 100% or less B: Methylene blue transmittance is 20% or more and less than 70% C: Methylene blue transmittance is 0% or more and less than 20%

Comprehensive evaluation Each of the above evaluation items was comprehensively evaluated according to the following criteria.
Good: Each of the above evaluation results is "A" and does not include "B" or "C".
Defective: In each of the above evaluation results, "B" or "C" is included.

The produced photocatalyst-supported magnetic material sample 1-1 (Example 1), sample 1-2 (Example 2), sample 1-3 (Example 3), sample 1-4 (Example 4), and comparative sample 1. (Comparative Example 1), Comparative Sample 2 (Comparative Example 2), and Comparative Sample 3 (Comparative Example 3) were evaluated.
The results of each of the above evaluations are summarized in Table 1.

As is clear from the evaluation results shown in Table 1, it is considered that the photocatalyst-supported magnetic material of Comparative Example 1 became cloudy after the durability test and the photocatalyst was detached. Therefore, the transmittance was lowered in the methylene blue decomposition test after the durability test.
Further, in Comparative Example 2 and Comparative Example 3, no change was observed in the methylene blue decomposition test because the photocatalyst was not contained.

Since the photocatalyst-supporting magnetic material of Examples 1 to 4 contains metal particles or metal compound particles having a larger primary particle diameter than the photocatalyst on the surface, this acts as a buffer when shaken to release the photocatalyst. It is thought that this is suppressed. Therefore, the supernatant was transparent. It is considered that this has the effect of decomposing methylene blue even after the durability test.

The photocatalyst-supporting magnetic material according to the present invention disperses in water, irradiates light to activate the photocatalyst, and includes a purification step of decomposing compounds present in the water, which requires water purification and algae prevention. Can be used for purification. Furthermore, the photocatalyst-supported magnetic material used for water purification can be moved and recovered using a magnet, then regenerated after undergoing a washing and / or drying process, and can be used again for water purification, and its industrial value is high. Very expensive.

Claims (10)

A photocatalyst-supporting magnetic material having a core-shell structure composed of a core layer and a shell layer containing the core layer, wherein the core layer contains a magnetic material and the shell layer has a siloxane unit, a photocatalyst, and primary particles rather than a photocatalyst. becomes large metal particles or metal compound particles having a diameter from at least containing to Turkey computing material, photocatalyst, characterized in that the shell layer contains as a part of the surface of the photocatalyst and the metal particles or metal compound particles are exposed Supporting magnetic material. The photocatalyst-supported magnetic material according to claim 1 , wherein the magnetic material is ferrite. It said component having siloxane units, a photocatalyst-carrying magnetic material according to at least organopolysiloxane including請Motomeko 1 or 2. The metal particles or metal compound particles, copper, at least Tsuo含No請Motomeko 1-3 photocatalyst carrying magnetic body according to any one of selected from zinc or silver. The photocatalyst-supported magnetic material according to any one of claims 1 to 4 , wherein the coating material is for preparing a photocatalyst. A purification step of dispersing the photocatalyst-supporting magnetic material according to any one of claims 1 to 5 in water, irradiating it with light to activate the photocatalyst, and decomposing organic substances existing in the water is included. A characteristic water purification method. The water purification method according to claim 6 , wherein the water is water from a domestic or factory wastewater reservoir. The method for purifying water according to claim 6 or 7 , wherein the photocatalyst-supported magnetic material is moved or recovered using a magnet. The method for purifying water according to any one of claims 6 to 8 , wherein the photocatalyst-supported magnetic material is subjected to a washing and drying step. The method for purifying water according to any one of claims 6 to 9 , wherein the photocatalyst-supported magnetic material is regenerated by a washing and drying step and reused in the purifying step.

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