JP2003334454A - Ultraviolet/visible light-sensitive catalyst - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultraviolet/visible light-sensitive catalyst composite material and its application. <P>SOLUTION: The composite material contains a photocatalyst as represented by titanium dioxide and a sold peroxide and exhibits a photocatalytic activity under ultraviolet and visible light. The composite material is used for cleaning the environment. The composite material is used in a cleaning agent, paint, spray agent, soilproof agent, deodorant, and bleaching agent. The composite material is used for coating articles having a photocatalytic activity under ultraviolet and visible light. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel ultraviolet / visible light active catalyst and its use. More specifically, a new titanium dioxide-based photocatalyst composite material having photocatalytic activity in the ultraviolet and visible light regions, Environmental purification method using composite material, cleaning agent, paint, spray agent, bleaching agent, article coated with the composite material and having photocatalytic activity under UV / Visible light, under UV / visible light coated with the above spray agent The present invention relates to applications such as articles having a photocatalytic action and articles having functions such as antifouling property and deodorant property. INDUSTRIAL APPLICABILITY The present invention is useful as a novel type of ultraviolet / visible light-reactive photocatalyst that exhibits no deterioration in photocatalytic activity in the ultraviolet region and exhibits excellent photocatalytic activity even in the visible light region, and its use.

[0002]

2. Description of the Related Art Heretofore, various research results have been reported on a composite photocatalytic material in which a photocatalyst such as titanium dioxide is mixed with another functional material to combine a photocatalytic function and another function. Among these, first, the following are mentioned as the titanium dioxide photocatalyst particles coated with apatite. 1) Japanese Patent Application No. 9-63867 “Environmental purification material and its manufacturing method” 2) T.K. Nonami ,, Apatiti form
ation on Ti02 photocataly
st in a pseudo body solut
Ion, Material Research Bull
etin, 33, 125-131 (1998) 3) Nonami Toru, apatite-coated titanium dioxide photocatalyst, eco-industry, 3, 5-13 (2000) The above relates to apatite-coated titanium dioxide. In the above-mentioned document, a method for coating apatite, a method for forming a coating material, and the antibacterial property, antifouling property, air cleaning property, water treatment property and the like are proposed.

The following are examples of antibacterial and bleaching of teeth using the above composite particles. 4) Japanese Patent Application No. 9-27650 “Titanium dioxide photocatalyst discoloring tooth bleaching method” 5) Japanese Patent Application No. 11-155453 “Bleaching agent for home bleaching” 6) Toru Nonami, Takuro Ishibashi, Osamu Kondo, Titanium dioxide photocatalyst Whitening and safety test, Japanese Society of Dental Aesthetics, Vol. 13, No. 2,47-51 (200
1) These relate to photocatalytic tooth bleaching,
The above-mentioned literature reports on the composition of the bleaching solution, the bleaching method, irradiation lamps, systems, etc., and proposes irradiation with light of 400 nm.

Further, as a cleaning agent for articles using a composite material, the present inventors have proposed a composition for preventing deodorant contamination of dental products, a cleaning material, a contact lens cleaning / disinfecting / preservative composition, and We have developed a cleaning / disinfecting / preserving container, a dental prosthesis cleaning system, a bath agent composition, etc., and applied for a patent. The above is related to the cleaning of dentures and contact lenses by a photocatalyst, and the purification of water in a bath. In the above literature, use as an antibacterial agent is also proposed. However, nothing has been proposed regarding peroxides. In addition, as a compound having photooxidation activity, the present inventors have developed a compound having photoactivity as an environmental protection material and its use, and previously filed a patent application.

As described above, various kinds of composite photocatalyst materials in which a photocatalyst such as titanium dioxide is combined with another functional substance to form a composite have been proposed, but the following problems are problems of the conventional techniques. be pointed out. First, a)
Regarding photocatalysts, they do not have sufficient ability to adsorb and decompose harmful organic substances, b) they are not so effective even when exposed to strong ultraviolet rays, c) they do not adsorb substances, and d) they have no effect unless they are exposed to light. There's a problem. Further, regarding the visible light type photocatalyst, e) the photoactivity of the visible light part is improved, but the activity in the ultraviolet region is deteriorated and the activity is almost lost.
f) There are problems that the total activity of ultraviolet light and visible light is the same as that of conventional photocatalyst, g) the manufacturing method is difficult, and the cost is high.

[0006]

Under such circumstances, the present inventor has, in view of the above-mentioned prior art, a new composite photocatalytic material capable of surely solving the problems found in the above-mentioned prior art. The research was started with the goal of developing Here, the background of the present invention will be described.
The present invention was started by conducting an organic substance decomposition experiment using a composite material in which titanium dioxide was mixed with a peroxide, and by mixing the two, a remarkable effect was obtained as compared with using them alone. It was found that it was obtained, but at this stage, the wavelength of light to be activated was completely unknown. That is, it was found that the composite material naturally reacts to ultraviolet light having a wavelength of 380 nm or less, but surprisingly, it is activated even when irradiated with visible light. Usually, titanium dioxide contains a small amount of impurities, and the reaction region shifts to a slightly higher wavelength side depending on the impurity potential. In the case of the anatase type, the theoretical shift of 380 nm to around 400 nm actually occurs in commercially available titanium dioxide. Further, in the case of the rutile type, since the band gap energy is originally smaller than that of the anatase type, 400 n
Reacts to light near m. Since light near 400 nm can be said to be visible light, it can be said that this is also a photocatalyst that reacts with visible light.

However, in the above experiment, the higher wavelength of 4
It was considered to react even at 50 nm or more. Therefore,
As a result of detailed investigation of the wavelength of reaction using a spectral irradiation device (a device that disperses and irradiates light at 20 nm intervals), it was found that the composite material described above also responds to wavelengths of 500 nm or more. 450 to 500n for sunlight and fluorescent light
It was found that this composite material has a much higher photocatalytic effect than the conventional photocatalyst and can be used very effectively because the light with the wavelength of m is contained most. The present invention has been completed based on the above new findings. That is, an object of the present invention is to provide a new composite photocatalytic material having a high photocatalytic activity under ultraviolet and visible light. The present invention also provides
It is an object of the present invention to provide a new type of composite photocatalytic material which reacts to a wavelength of m or longer and which does not deteriorate the ultraviolet activity. Further, the present invention aims to provide a use of an environmental purification method using the above composite material, a cleaning agent, a paint, a spray agent, a bleaching agent, and an article having functions such as antifouling property and deodorant property. It is what

[0008]

The present invention for solving the above-mentioned problems comprises the following technical means. (1) A composite material having a photocatalytic activity under ultraviolet / visible light, which comprises a photocatalyst typified by titanium dioxide and a solid peroxide. (2) The composite material as described in (1) above, wherein the titanium dioxide is a rutile type. (3) The composite material as described in (1) above, wherein the particle size of titanium dioxide is 50 nm or less. (4) The composite material as described in (1) above, wherein the peroxide is a powdered inorganic peroxide. (5) The composite material as described in (1) above, wherein the peroxide is sparingly soluble in water. (6) The composite material as described in (1) above, wherein titanium dioxide is coated with calcium phosphate. (7) The composite material as described in (6) above, wherein the calcium phosphate has photoactivity (photooxidation function). (8) The above composite material contains a chelate component (1)
The described composite material. (9) The chelate component is silicate, phosphate, phosphoric acid,
The composite material according to (8) above, which is one kind or two or more kinds selected from the group of citric acid. (10) Environmental purification characterized by using the composite material according to any one of (1) to (9) to decompose organic substances existing in an aqueous system or an atmospheric system under light irradiation and perform purification treatment. Method. (11) The environmental purification method according to (10), wherein the environmental purification is atmospheric purification or water purification. (12) A cleaning agent for cleaning an article, comprising the composite material according to any one of (1) to (9) above. (13) The cleaning agent according to (12), wherein the article is a decorative article, food, clothing, electronic component, mechanical component, or medical device. (14) An article having a photocatalytic action under ultraviolet / visible light, which is coated with the composite material according to any one of (1) to (9). (15) A coating material comprising the composite material according to any one of (1) to (9). (16) An article having a photocatalytic action under ultraviolet / visible light, which is obtained by applying the coating material according to (15) above. (17) A liquid agent comprising the composite material according to any one of (1) to (9). (18) A spray agent comprising the liquid agent according to (17) above. (19) An article having a photocatalytic action under ultraviolet / visible light, which is obtained by coating the composite material by spraying the spray agent according to (18) above. (20) An antifouling agent comprising the composite material according to any one of (1) to (9). (21) An article having an antifouling effect under ultraviolet / visible light, which is coated with the antifouling agent as described in (20) above. (22) A deodorant comprising the composite material according to any one of (1) to (9). (23) An article having a deodorizing effect under ultraviolet / visible light, which is coated with the deodorant according to (22). (24) A bleaching agent comprising the composite material according to any one of (1) to (9).

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described in more detail. The present invention relates to a novel composite photocatalyst material which exhibits photocatalytic activity in the ultraviolet and visible light regions, which is obtained by mixing a photocatalyst represented by titanium dioxide and a peroxide and compounding them. In the present invention, as a photocatalyst represented by the titanium dioxide, a titanium dioxide-based photocatalyst,
Although other oxide semiconductor photocatalysts are used, a titanium dioxide photocatalyst is preferably used. The titanium dioxide photocatalyst may be anatase type, rutile type that reacts with visible light, or brookite type as long as it has photocatalytic activity. The titanium dioxide may be ordinary titanium dioxide for photocatalyst, but titanium dioxide for rutile type or pigment is preferably used. The particle size of the titanium dioxide is preferably 50 nm or less, more preferably 1 nm to several nm. Further, as the photocatalyst,
Other oxide semiconductors having photocatalytic activity may be used, and examples thereof include zinc oxide, silicon carbide, molybdenum disulfide, ferric oxide, indium oxide, and tungsten trioxide. .

Explaining these in more detail, the crystal system of titanium dioxide is anatase type, rutile type,
It may be either brookite type or amorphous,
The rutile type is preferable. Its shape is 10 microns or less, preferably 500 nm or less, more preferably 50
nm or less. The shape of the photocatalyst may be powder or thin film. Ultimately, these photocatalysts are thin films, sol-gel films, spatter films, paint films, sintered products, etc.
It is used in an appropriate form. The content of titanium dioxide is
0.001 wt% -99 wt%, more preferably 0.0
1 wt% -5 wt%, more preferably 0.01 wt%-
1 wt%.

Next, in the present invention, it is preferable to coat the titanium dioxide with calcium phosphate. When the titanium dioxide is coated with calcium phosphate, as the calcium phosphate, for example, apatite, 8 calcium phosphate, 4 calcium phosphate, 3 calcium phosphate or the like is used. However, the present invention is not limited to these, and any of those having a phosphate ion and calcium ion and having an organic substance adsorbing property can be similarly used. As the apatite, hydroxyapatite, carbonate apatite, fluorapatite and the like are used.

Further, in the present invention, titanium dioxide can be coated with photoactive calcium phosphate. As such calcium phosphate, photoactive (photooxidation function)
A compound represented by Ax (BOy) zX (A is Ca, Co, Ni, Cu, Al, La, Cr, Fe, M
One or more of various metal atoms such as g, B is P, S
And X is one or more, and X is one or more of OH, a halogen atom (for example, F, Cl), CO ₃ or the like).
In this case, preferably, a photocatalyst such as titanium dioxide to which a compound consisting of one or more Ax (BOy) zX is partially attached is exemplified.

The above-mentioned calcium phosphate is, for example, Ax.
(BOy) zX may be composed of only one or more compounds, and may be crystalline or amorphous. In the case of crystalline, calcium phosphate crystals such as apatite, tricalcium phosphate, octacalcium phosphate and the like may be used. Regarding the compound having one or more Ax (BOy) zX, the size of the compound having one or more Ax (BOy) zX is preferably 0.01 nm to 50 μm, more preferably 0.1 nm to 10 nm. In this case, 1 to 99% of the surface of titanium dioxide is A
It is preferable that x (BOy) zX is covered with a compound of one or more.

The compound consisting of one or more Ax (BOy) zX is formed by the cluster Ax (BOy) zX formed in the solution if nothing is added to the simulated body fluid. This simulated body fluid is, for example, NaCl or NaHCO 3.
_{3, KC1, K 2 HPO 4} · 3H 2 O, MgC1 2 · 6
H ₂ O, CaC1 ₂ and Na ₂ SO4 or NaF, F
ESO _4, FeCl ₃ and the like, are prepared by dissolving in water. Further, it is preferable to adjust the pH to 7 to 8, particularly 7.4 by using HC1 or (CH ₂ OH) ₃ CNH ₂ .

The composition of the simulated body fluid used in the present invention is, for example, Na ⁺ 120 to 1000 mM, K ⁺ 1 to
200 mM, Ca ²⁺ 0.5-100 mM, Mg ²⁺ 0.5
^~50mM, C1 ^{- 80~2000mM,} HCO3 -
_{^{0.5~300mM, HPO 4 2 - 1~200mM,}} SO
_{^{4 2- 0.1~200mM, F - 0~5mM,}} Fe, C
One or more metal ions such as r, Zr, and Al are 0.1 to 20.
mM is exemplified, but not limited to the above. In the case of the above composition, if the concentration is lower than this, Ax
Precipitation of the compound consisting of one or more (BOy) zX takes time, and if the concentration is higher than this, precipitation of the compound consisting of one or more Ax (BOy) zX occurs rapidly, making it difficult to control the shape and particle size. Become.

The present invention is most characterized by containing a photocatalyst represented by titanium dioxide and a solid peroxide. In the present invention, preferable examples of the peroxide include percarbonate, perphosphate, persulfate, calcium peroxide, magnesium peroxide, urea peroxide and the like. These are preferably used in the form of powder. In the present invention, preferably, the photocatalyst typified by titanium dioxide and the peroxide powder can be mixed appropriately to form a composite. The mixing ratio of the peroxide is
0.1 wt% -99 wt%, more preferably 10 wt%
It is −70 wt%. In the present invention, a chelate component is preferably added. Examples thereof include silicate, phosphate, phosphoric acid and citric acid. Among these, examples of the silicate include magnesium silicate and sodium magnesium silicate. The mixing ratio of these is 0.01 wt% -10 wt%, more preferably 0.1 wt% -5 wt%.

As phosphates, phosphates and condensed phosphates are used, and examples of these include sodium salts such as orthophosphoric acid, phosphoric acid, pyrophosphoric acid and tripolyphosphoric acid,
Examples include potassium salt and tetrasodium pyrophosphate. As phosphoric acid, phosphoric acid, pyrophosphate, polyphosphate,
Tripolyphosphate, acetic acid, citric acid, tartaric acid, malic acid,
Examples include formic acid, gluconic acid, silicic acid, succinic acid, oxalic acid, sorbic acid, hydrochloric acid, sulfuric acid, lactic acid, folic acid, butyric acid and the like. The mixing ratio of these is 0 to 90 wt%, and more preferably 5 to 50 wt%. The mixing ratio of citric acid is 0
It is -70 wt%, more preferably 10-50 wt%.

In the present invention, the irradiation light need not be used, but the irradiation light is preferably sunlight (even through a window), fluorescent lamp, black light, UV, xenon, metal halide, halogen or the like. The thing containing the light of 500 nm or less is illustrated. In the present invention, light sources for light irradiation that can be preferably used include sunlight, fluorescent lamps, light emitting diodes, UV lights, black lights, semiconductor lasers, incandescent lamps, quartz lamps, mercury lamps, xenon lamps, metal halide lamps, incandescent lamps. Examples include lamps, halogen lamps, cold cathode lamps, and the like.

In the present invention, a composite material of titanium dioxide and peroxide for rutile type or pigment, which is considered to have insufficient function as a photocatalyst, is generally 400 to 500 nm.
It was completed by further research based on the new knowledge that it is activated by visible light. The activation under visible light is less effective in the anatase type titanium dioxide than in the rutile type. The visible light of 450 to 500 nm is also included in many sunlight and fluorescent lamps.
Applications can be expected to expand in various fields. In particular, the effect is remarkable when titanium dioxide is coated with calcium phosphate such as apatite. This is because the presence of calcium phosphate on the surface ideally makes the contact between titanium dioxide and peroxide. Also,
Calcium phosphate adsorbs harmful substances, in this case,
In particular, a high effect can be expected by coating a compound having photoactivity and calcium phosphate having photoactivity. In the present invention, further, activation under visible light is promoted by mixing a chelating agent such as a silicate with the component of the above composite material.

The composite of titanium dioxide and peroxide must be carried out by allowing them to effectively exist on the surfaces of the peroxide and titanium dioxide. Therefore, a peroxide that can be provided as a powder is preferable. A highly active material can be obtained by previously mixing powders of titanium dioxide, a peroxide, and a chelate component. These may be mixed with a mortar or a mixing mill. Particularly, a powdery peroxide which is hardly soluble such as sodium perborate is preferable because it is gradually dissolved when consumed in an aqueous solution, and the effect continues. It should be noted that the hydrogen peroxide solution is immediately decomposed into water and oxygen, and the effect of visualizing the water does not continue. In the present invention, sodium percarbonate, sodium perborate and the like can be used, and since these peroxides can be provided in the form of powder unlike the above hydrogen peroxide, the usability is significantly improved,
It can be expected that the range of applications will be greatly expanded.

The activation of titanium dioxide under visible light is due to the temporary generation of oxygen defects in titanium dioxide due to the reaction with peroxide. The conventional visible light-reactive photocatalyst is activated under visible light because it permanently creates oxygen defects, but at the same time, the activity of the ultraviolet light portion is deteriorated. On the other hand, in the composite material of the present invention that is composited with the peroxide, the generation and disappearance of oxygen defects are repeatedly moved, so that the visible light portion and the ultraviolet light portion are highly active in the total ultraviolet light and visible light. In the above composite material, the decomposition function of the organic substance is significantly improved as compared with the case where titanium dioxide or peroxide is used alone. It is considered that in the above titanium dioxide coated with calcium phosphate, the generation and disappearance of the oxygen defects are ideally controlled. Furthermore, since the above-mentioned peroxide is a substance which has a substance-decomposing effect alone, a certain effect can be obtained without irradiation of light. Further, calcium phosphate has a function of adsorbing aldehydes, nitrogen oxides, etc. regardless of the presence or absence of light.

The greatest feature of the present invention lies in that titanium dioxide is mixed with a peroxide and they are compounded, whereby the effect of decomposing and removing harmful organic substances, bacteria and coloring components is obtained. Greatly improved. In addition, the activity of the ultraviolet part does not deteriorate, the photocatalytic activity in visible light is activated, and a composite material having a photocatalytic effect even when not exposed to light can be obtained. In particular, by using titanium dioxide coated with photoactive apatite, a remarkable and reliable photocatalytic effect can be obtained.
A composite material having high photocatalytic activity can be obtained by mixing a composite material containing titanium dioxide and a peroxide with a silicate or the like serving as a chelate component.

The composite material of the present invention can be used for environmental purification, atmospheric purification, water purification and the like as its application fields. Specifically, for example, pool, bath, river,
Sea, factory wastewater, domestic wastewater, ponds, artificial rivers, building materials, trains,
It is useful for removing dirt and odors from automobiles. Further, the composite material of the present invention is a cleaning agent for articles, specifically,
For example, fungi such as clothing, electronic parts, food, automobiles, trains, ships, electrical products, medical equipment, tiles, tile joints, building materials, contact lenses, ornaments, machine parts, tableware, forks, knives, glass, and living bodies. It is useful for removing mold, stains, odors, harmful organic substances and bleaching. In the present invention, the term “article” refers to any type of article in which a titanium dioxide-based photocatalyst has been conventionally used (excluding dentistry such as artificial teeth).
It goes without saying that it is meant to include. Examples of these articles include building materials, automobile members, train members, electric appliances, stationery, clothing, bedding, medical equipment, artificial flowers, phones, tableware, packaging materials, food wraps, food storage containers, and the like. It is not limited to these.

[0024]

In the present invention, the photoreactivity is synergistically improved by mixing titanium dioxide, particularly rutile type titanium dioxide, and peroxide to form a composite. Titanium dioxide and peroxide alone can decompose and remove a trace amount of harmful organic substances and bacteria, but cannot decompose and remove particularly colored substances and stains. However, by combining the two, a synergistic effect is obtained, and terrible stains and odors that could not be achieved by themselves can be efficiently decomposed and removed in a short time.
These effects are further enhanced when a chelate component such as a silicate compound is mixed. In addition, by coating titanium dioxide with calcium phosphate, the mixture of titanium dioxide and peroxide is ideal, that is, the supply of peroxide to the surface of titanium dioxide particles is carried out smoothly and little by little. A remarkable effect can be obtained as compared with the case of using a single body.

The composite material of the present invention is activated by irradiation with visible light which does not react with titanium dioxide alone, and reacts with visible light of 400 to 500 nm. In addition, the activity of the conventional visible light-reactive photocatalyst is not deteriorated, and the activity of ultraviolet rays is not deteriorated at all. Further, by blending the above composite material with a peroxide, an acid, calcium phosphate or the like, it is possible to decompose and remove the organic substance without irradiating light. This composite material can adsorb aldehydes, ammonia, etc. by the effect of peroxides and calcium phosphates without irradiating light, but the effect is about half that of light irradiation. The present invention has an advantage that all materials including titanium dioxide can be provided as a powder because a solid peroxide can be used, and a significant improvement in activity can be seen by using the powder. At the same time, the advantage that the activity continues can be expected.

[0026]

EXAMPLES Next, the present invention will be specifically described based on examples, but the present invention is not limited to the following examples. Test Example 1 (combination use of titanium dioxide and peroxide) (1) Preparation of composite material 14 mg of zinc nitrate was added to 2 liters of simulated body fluid, and titanium dioxide (MT150A, 15 manufactured by Teika Co., Ltd.) was added thereto.
nm) was added. The composition of the simulated body fluid is Na ⁺ 14
5.0, K ⁺ 4.2, Mg ²⁺ 0.5, Ca ²⁺ 0.9, C
_{^{- 141.0, HCO 3 - 0,}} HPO 4 2- 9.5, SO
₄ was ^2- 0 (mM). It was kept at 37 ° C. and aged for 1 hour to prepare titanium dioxide coated with photoactive apatite. When the ultraviolet visible light reflectance was measured, it was found that apatite had absorption at 300 to 200 nm and had photoactivity. This activated apatite titanium dioxide 0.
06g, sodium percarbonate 3g, magnesium silicate 1
g were mixed (activated apatite titanium dioxide). This was evenly spread on a petri dish, put in a 5 liter Tedlar bag, and filled with 100 PPM of formaldehyde (in nitrogen). For comparison, titanium dioxide coated with activated apatite titanium dioxide and titanium dioxide coated with apatite (apatite titanium dioxide; the same as the method for producing the above composite material except that zinc nitrate was not added) were used.

(2) Photocatalytic activity Black light (1 mW / cm ² ) was irradiated for 0 to 5 hours to measure the concentration of formaldehyde. The results are shown below. Initially 1 hour 3 hours 5 hours Active apatite titanium dioxide 100 0 0 0 Titanium dioxide 100 100 20 20 Apatite titanium dioxide 100 10 0 0 The above active apatite titanium dioxide is the above active apatite titanium dioxide, 14 mg of iron sulfate is added in place of zinc nitrate, and active apatite titanium dioxide is added. Was prepared, and black light was irradiated in the same manner as above except that 1 g of citric acid was mixed.
It decreased to 0 ppm after 0 minutes. The results of measuring the formaldehyde concentration in the dark are shown below. Initially 1 hour 3 hours 5 hours Active apatite titanium dioxide 100 20 20 10 Titanium dioxide 100 70 70 60 50 Apatite titanium dioxide 100 30 25 25 20

Test Example 2 (Test on Mixing Method) Basically, titanium dioxide and peroxide are first mixed and then mixed in a mortar or the like. With rutile titanium dioxide, it begins to turn yellow immediately after mixing,
After about 10 to 15 minutes, the discoloration becomes more intense and turns yellow. In the case of the anatase type and titanium dioxide, which is less active in the end, the color does not change immediately after mixing, and the mixing should be 30%.
When it continues for about a minute, it finally turns yellow. In addition to the mortar, the mixing can be performed with a generally industrially used mixing device such as a ball mill, a sand mill, and a stirrer. If the mixing is not carried out sufficiently, the contact between titanium dioxide and the peroxide will be insufficient, and visible light activation and activation as shown in the graph will not occur. In addition, discoloration to yellow does not occur enough. In addition, if all the reagents are mixed at the same time or if the order is changed, the pH fluctuates to alkaline and the effect is small. Mixing can also be done in the presence of water.

In this test example, the difference in action and effect depending on the mixing method of titanium dioxide and peroxide was examined. A: 3 g of sodium perborate; B: 2 g of sodium tripolyphosphate, 0.5 g of sodium metasilicate,
0.04 g of magnesium silicate; D: 2.5 g of citric acid; C: 0.03 g of MT-150A (rutile titanium dioxide) (Taika Co., Ltd.). First, mortar A and C in powder form. Well mixed. It was found that when mixed for about 15 minutes, it was colored yellow, responsive to visible light and activated. B and D were added to this and shaken well. This powder was dissolved in water to make 1 liter. At this time, pH
Was 4.34. Take 3 cc of this aqueous solution, 10 p
Methylene blue powder was added to reach pm. Then, black light 6W was irradiated. As a result, methylene blue became 2 ppm in 5 minutes and 0 ppm in 10 minutes.

As a comparative example, A to D were mixed. The pH was 5.6. Take 3cc of this aqueous solution, 10ppm
Methylene blue powder was added so that. Then, black light 6W was irradiated. As a result, it was found that methylene blue was 6 ppm in 5 minutes and 4 ppm in 10 minutes, which was different depending on the mixing method of the above components.

Test Example 3 A: 2 g of sodium perborate; B: 1 g of sodium tripolyphosphate, 0.5 g of sodium metasilicate,
0.04 g magnesium silicate; D: 2 citric acid
g; C: 0.03 g of MT-150A was prepared, and first, A and C were well mixed in a powder state in a mortar. It was found that when mixed for about 15 minutes, it was colored yellow, responsive to visible light and activated. B and D were added to this and shaken well. This powder was dissolved in water to make 1 liter. At this time, the pH was 4.4. 3 cc of this aqueous solution was taken, and methylene blue powder was added so as to have a concentration of 10 ppm. Then, black light 6W was irradiated. As a result, methylene blue was 1 ppm in 5 minutes and 0 pp in 8 minutes.
It became m.

Test Example 4 A: 3 g of sodium perborate; B: 2 g of sodium tripolyphosphate, 0.5 g of sodium metasilicate,
0.04 g of magnesium silicate; D: 2.5 g of citric acid; C: 0.03 g of AMT-100 (Taika Co., anatase type titanium dioxide) is prepared. First, A and C are powdered in a mortar. Well mixed. It does not turn yellow even after mixing for about 15 minutes, but it turns yellow in about 30 minutes.
It was found to be responsive to visible light and activated. B to this
And D were added and shaken well. Dissolve this powder in water,
I made it 1 liter. At this time, the pH was 4.4.
3 cc of this aqueous solution was taken, and methylene blue powder was added so as to have a concentration of 10 ppm. Next, black light 6W
Was irradiated. As a result, methylene blue is 9p in 5 minutes
pm reached 6 ppm in 10 minutes.

Test Example 5 A: 3 g of sodium perborate; B: 2 g of sodium tripolyphosphate, 0.5 g of sodium metasilicate,
0.04 g of magnesium silicate; D: 2.5 g of citric acid; C: 0.03 g of MT-150A (coated with apatite) is prepared. First, A and C are in powdered state in a mortar. Mixed. It was found that when the mixture was mixed for about 10, it was colored yellow, and was responsive to visible light and activated.
B and D were added to this and shaken well. This powder was dissolved in water to make 1 liter. At this time, the pH is 4.34.
Met. 3 cc of this aqueous solution was taken, and methylene blue powder was added so as to have a concentration of 10 ppm. Then, black light 6W was irradiated. As a result, methylene blue
It became 2 ppm in 3 minutes and became 0 ppm in 7 minutes.

Test Example 6 A: 0.01 g of sodium perborate; B: 1 g of sodium tripolyphosphate and 0.
5 g, 0.04 g of magnesium silicate; D: 1 g of citric acid; C: 0.03 g of MT-150A was prepared, 50 cc of water was added to A and C, and they were mixed well in a mortar.
It was found that when mixed for about 15 minutes, it was colored yellow, responsive to visible light and activated. B and D and water 50cc
Was added and shaken well. At this time, the pH was 1.9. 3 cc of this aqueous solution was taken, and methylene blue powder was added so as to have a concentration of 10 ppm. Then, black light 6W was irradiated. As a result, it became 3 ppm in 5 minutes and 1 ppm in 10 minutes.

Example 1 (1) Preparation of Composite Photocatalytic Material Titanium dioxide (rutile type) powder 0.02% (hereinafter,% means% by weight) and sodium percarbonate powder 3
% To prepare a composite photocatalytic material containing a titanium dioxide photocatalyst and a solid peroxide. (2) Dissolve 10 ppm of photocatalytically active methylene blue of the composite material in water to obtain an optical path of 1 cm
In a quartz cell. In addition, the above composite material (final concentration: sodium perborate / 1%, TiO ² /0.06
%), Peroxide (final concentration: sodium perborate / 1
%) Or titanium dioxide alone (final concentration: TiO ₂ /
0.06%) was added and the light of a metal halide lamp was irradiated, and the absorbance after 30 minutes was measured. The result is shown in Figure 1.
Shown in. As a result, by using the above composite material,
It was found that high photocatalytic activity (methylene blue decomposition action) was obtained in the ultraviolet and visible light regions.

Example 2 (1) Preparation of composite photocatalyst material Titanium dioxide coated with calcium phosphate (rutile type)
A 0.02% powder and a 3% sodium percarbonate powder were mixed to prepare a composite photocatalytic material containing a titanium dioxide photocatalyst and a solid peroxide. (2) The photocatalytic activity of the composite material: 1% of hematoporferin was dissolved in ethyl alcohol, and a glossy paper for inkjet printer was immersed in this for 1 minute. The above composite material was applied to this hematoporphyrin dyed paper, and the light of a metal halide lamp was irradiated for 5 minutes. The lightness L * was measured with a color difference meter before and after the light irradiation. As a result, L * = 65 was initially 82, and it was found that by using the above composite material, remarkable photocatalytic activity (bleaching action) was obtained as compared with the case of using titanium dioxide alone. It was The value of L * is
It shows the brightness, and the larger the number is, the higher the photocatalytic action is obtained, and the color of the dyed paper becomes whiter.

Example 3 (Decomposition of methylene blue) 10 ppm of methylene blue was dissolved in water and placed in a quartz cell having an optical path of 1 cm. This was irradiated with light, and the absorbance of light having a wavelength of 630 nm was measured before and after the light irradiation. That is, the composite material prepared in Example 1 (final concentration: sodium percarbonate 2% and titanium dioxide 0.06%), peroxide (final concentration: sodium percarbonate 2%), or titanium dioxide alone (final concentration: Titanium dioxide 0.06% only) in each of the above quartz cells,
The light of a metal halide lamp was irradiated, and the absorbance after 0 to 5 hours was measured. The result is shown in FIG. As a result, it was found that a remarkable photocatalytic activity (methylene blue decomposition action) can be obtained by using the above composite material.

Example 4 (Washing of tar and the like adhering to paper) Phosphoric acid 1%, magnesium silicate Na 1%, sodium tripolyphosphate 1%, sodium percarbonate (3, 5, 2, or 1%), titanium dioxide A cleaning agent was prepared by mixing 0.02%. Five cigarettes were lit in a desiccator and placed in a petri dish. A glossy paper was laid under the petri dish. I took out the paper after the fire was completely extinguished. The paper was stained with tar and was colored brown.
Using this, the lightness L * was measured with a color difference meter. A piece of paper
The sample was cut into 5 cm × 5 cm and placed in a 5 × 1 × 1 cm quartz cell together with the above cleaning agent. After 30 minutes, the brightness was measured again. When the tar is decomposed, it becomes close to the white color of the original paper, and the lightness increases. This was used as an index for the decomposition of the tar.
The above experiment was conducted using a black light as the irradiation light. As a result, the L * value is sodium percarbonate 3, 5,
2 or 1% at 14.47, 16.58, 1 respectively
It was 1.62 and 11.31, and it was found that in any case, the L * value increased by 10 or more, and high photocatalytic activity (cleaning action) was obtained. Also, phosphoric acid 2%, magnesium silicate Na 1%, sodium tripolyphosphate 5%, sodium percarbonate 3%, titanium dioxide (15 nm rutile 0.0
2%, 15 nm anatase 0.1% or 6 nm anatase 0.2%) to prepare a cleaning agent, and
As a result of measuring the L * value by the same method as described in (2), the L * value was 25.18 for rutile, 11.50 for 15 nm anatase, and 12.50 for 6 nm anatase.
In each case, it was found that the L * value increased by 20 or more, and high photocatalytic activity (cleaning action) was obtained.

Example 5 (Washing of ornaments) 1) Sodium percarbonate powder 3%, magnesium sodium silicate powder 1%, sodium tripolyphosphate powder 1
%, And 0.02% of titanium dioxide (rutile type) powder coated with calcium phosphate was mixed to prepare a powdery cleaning agent. Apply the above cleaning agent to a silver ring with a dark surface,
For 30 minutes, 12 W of black light was irradiated for 20 cm. As a result, a metallic glossy surface similar to that of a new product was obtained. 2) Sodium percarbonate powder 3%, sodium magnesium silicate powder 1%, sodium tripolyphosphate powder 1
%, And titanium dioxide (rutile type) powder 0.02% were mixed to prepare a powdery cleaning agent. Dissolve the above cleaning agent in water and add a silver ring with a darkened surface to it for 60 minutes.
It was irradiated with 2 W of black light for 20 cm. As a result, a metallic glossy surface similar to that of a new product was obtained.

(Washing of dishes) 1) Sodium perborate powder 3%, sodium magnesium metasilicate powder 0.5%, magnesium silicate powder 0.04%, sodium tripolyphosphate powder 2%, calcium phosphate-coated titanium dioxide ( (Rutile type) powder 0.03% was mixed to prepare a powdery detergent. The above cleaning agent was applied to a silver knife and fork, and 12 W of black light was irradiated for 20 cm. After 10 minutes, there was no darkening on the surface. 2) Sodium perborate powder 3%, sodium magnesium metasilicate powder 0.5%, magnesium silicate 0.0
A cleaning agent was prepared by mixing 4%, sodium tripolyphosphate 2%, and titanium dioxide (rutile type) powder 0.03%. The above cleaning agent was dissolved in water, and a knife and fork made of silver were immersed in the cleaning agent, followed by irradiation with 12 W of black light for 20 cm. After 30 minutes, the darkening of the surface disappeared completely.

Example 6 (Washing of clothes) 1) Sodium perborate powder 3%, magnesium sodium metasilicate powder 0.5%, magnesium silicate powder 0.04%, sodium tripolyphosphate powder 2%, titanium dioxide rutile Powder 0.03%, citric acid powder 2.5
% Was mixed to prepare a powdery detergent. When the above cleaning agent was applied to a T-shirt worn for one day, odor and sweat disappeared in 60 minutes. 2) Sodium percarbonate powder 3%, sodium magnesium metasilicate powder 0.5%, magnesium silicate powder 0.04%, sodium tripolyphosphate powder 2%, apatite-coated titanium dioxide rutile powder 0.03
% And citric acid powder 2.5% were mixed to prepare a powdery cleaning agent. The above cleaning agent was dissolved in water, and a T-shirt worn for one day was immersed in the solution. After 30 minutes, odor and sweat disappeared.

Example 7 (Preparation of Article Coated with Photocatalytic Composite Material)
Titanium dioxide coated with calcium phosphate (rutile type)
Powder 0.02%, sodium percarbonate powder 3%, sodium magnesium silicate powder 1%, and sodium tripolyphosphate powder 1% were mixed to prepare a powdery composite photocatalytic material containing a titanium dioxide photocatalyst and a peroxide. . Using the above composite material, a coating material, a liquid agent, a spray agent, an antifouling agent, a deodorant, and a bleaching agent containing the above composite material were produced by a conventional method. Furthermore, using the above composite material, by a conventional method,
The composite material is used as an article (building material, automobile member, train member, electric appliance, stationery, clothing, sheets, pillow, medical device, artificial flower,
Phones, tableware, packaging materials, food wraps, food storage containers)
Then, various articles having antifouling properties and deodorant / deodorant functions were prepared.

Example 8 (Preparation of bleaching agent) The same method as described in Example 2 (2) above was carried out using a composite material prepared by mixing 0.06% titanium dioxide and 3.5% sodium perborate. The lightness L
* Was measured. As a result, L * = 64 was initially 87, and it was found that a remarkable bleaching effect can be obtained by using the above composite material as compared with the case of using titanium dioxide alone (FIG. 3). .

Example 9 (Preparation of antifouling agent) 0.3g of titanium dioxide, 3g of sodium perborate and 0.05g of magnesium silicate were mixed to prepare an antifouling agent. Next, this composite material was dissolved in water together with an organic binder and applied to an aluminum panel (for exterior). As a result of observing after one month, it was found that the coated part had significantly less stain than the uncoated part.

Example 10 (Preparation of Deodorant) A deodorant was prepared in the same manner as the composite material prepared in Example 7 above. Next, this composite material was dissolved in a 1% solution of polyvinyl alcohol and sprayed on the interior wall of the room. As a result of measuring the ammonia concentration in the room,
Initially 0.6ppm, but after 1 hour 0.05
reduced to ppm.

Example 11 (Preparation of coating material) 5% of a composite material prepared by the same method as in Example 1 above was mixed with 5% of an organic binder (vinyl-based synthetic resin emulsion) in 90% of water. A paint for spray coating (200 m ² / kg) was prepared by melting.

Example 12 (1) Preparation of composite photocatalytic material Titanium dioxide powder 1.3% and sodium percarbonate 9
8.7% was mixed to prepare a composite photocatalyst material containing a titanium dioxide photocatalyst and a solid peroxide. (2) Evaluation of composite photocatalyst material UV / visible spectrophotometer (Shimadzu UV-24
50) was used to measure the wavelength shift of each sample to the visible region. The measurement method is a diffuse reflection method in which the sample is embedded in a quartz cell, and the measurement wavelength region is 300 to 500 nm. The photocatalyst samples used here are rutile type titanium dioxide (2 types: MT-150A, Soekawa) and anatase type titanium dioxide (3 types: AMT-100, F-).
4 and ST-01). As a result, FIGS.
As shown in, it was confirmed that the absorption region was shifted to the visible light side only when sodium percarbonate or sodium perborate was added to the photocatalyst sample. in this way,
It was revealed that the addition of peroxide to the photocatalyst significantly improved the visible light absorption characteristics.

Example 13 (cleaning agent) A: 1 g of tripolyphosphoric acid, B: 2 g of phosphoric acid,
C: MT-150A 0.02 g, D: sodium percarbonate 3 g were prepared, and first, when B and D were mixed in a mortar for 10 minutes, they were colored yellow. A and C were added thereto, and the mixture was shaken in a container, and 100 cc of water was added to obtain an aqueous solution. At this time, the pH was 6.97. A paper with a tobacco tar was attached to this solution and irradiated with 6 W of black light. The L value, which indicates the brightness, was initially 63.24, but after 5 minutes it was 84.66 and was bleached.

Example 14 (Methylene Blue Decomposition Experiment) In this example, the difference between rutile and anatase and the effect of apatite coating were investigated. Example 1 as rutile
The composite material prepared in the same manner as in Example 1 was used, except that the composite material prepared in Example 1 was used as anatase and rutile was changed to anatase (F4 manufactured by Showa Denko KK) in the composite material of Example 1. A decolorization test of methylene blue was performed. The results are shown below. The values are the concentration of methylene blue (ppm)
Indicates. Percarbonate only Percarbonate Percarbonate rutile only Anatase only + + rutile anatase 0 min 10 10 10 10 10 10 1 min 9.5 5.7 8 9 9 8.5 3 min 9.5 2.2 6.5 6.5 8.5 8 5 minutes 9.5 1 3.5 9.5 7.5 As described above, it was found that rutile was more effective than anatase. Next, a similar experiment was conducted using rutile coated with calcium phosphate. MT-as rutile
150A (manufactured by Teika) was used. The results are shown below. It was found that the effect is enhanced by coating with apatite.

Example 15 As composition 1, A: 3 g of sodium percarbonate, B: 1 g of sodium tripolyphosphate, C: 1 g of sodium magnesium silicate, D: 2 g of phosphoric acid, E: MT-15
0A of 0.02 g was prepared. Also, as composition 2,
A: 3 g of sodium percarbonate, B: 1 g of sodium tripolyphosphate, C: 1 of sodium magnesium silicate
g, D: 2 g of phosphoric acid and E: 0.02 g of MT-150A (apatite coating) were prepared, and A and E were well mixed in a powder state in a mortar. It was found that when mixed for about 15 minutes, it was colored yellow, responsive to visible light and activated. To this, 91 g of water and B, C and D were added, and they were shaken well. Then, the cleaning results of the tar paper similar to that in Example 4 were examined. The results are shown in the table below. (Change in L value)

[0051]

As described above in detail, the present invention relates to a composite material having a photocatalytic action containing a photocatalyst typified by titanium dioxide and a peroxide, an environmental purification method using the composite material, and its use. According to the present invention, 1) it is possible to provide a new composite photocatalyst material having photocatalytic activity under ultraviolet / visible light, and 2) a photocatalyst sample is mixed with a peroxide so that the absorption region is on the visible light side. 3) In particular, a photocatalyst that reacts with visible light of 400 to 500 nm can be obtained. 4) By using the above composite material, an ultraviolet / visible light-reactive photocatalyst that reacts in the ultraviolet and visible light regions can be obtained. The resulting 5) the photocatalytic activity of the above composite material has excellent durability, 6) it is possible to produce various articles having a photocatalytic activity under light irradiation or without light irradiation, ) It is possible to provide a new environmental purification method using the above composite material, a cleaning agent, a paint, a liquid agent, a spray agent, an article having an antifouling effect, a deodorant, a bleaching agent, etc. It

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing the photocatalytic activity (methylene blue decomposition action) of the composite material of the present invention.

FIG. 2 is an explanatory diagram showing the photocatalytic activity (methylene blue decomposition action) of the composite material of the present invention.

FIG. 3 is an explanatory view showing photocatalytic activity (methylene blue decomposition action) of the composite material of the present invention.

FIG. 4 shows the results of measuring the wavelength shift of a sample to the visible region.

FIG. 5 shows the results of measuring the wavelength shift of a sample to the visible region.

FIG. 6 shows the results of measuring the wavelength shift of a sample to the visible region.

FIG. 7 shows the results of measuring the wavelength shift of a sample to the visible region.

FIG. 8 shows the results of measuring the wavelength shift of a sample to the visible region.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C09D 201/00 C09D 201/00 C11D 7/02 C11D 7/02 F term (reference) 4D037 AA01 AB01 BA16 BA18 CA11 4D050 AA01 AA06 AA10 AA15 AB11 BB01 BC06 4G069 AA02 AA03 AA08 AA11 BA04B BA15B BB14B BC02B BC09B CA10 EE01 4H003 BA09 DA01 DA14 DA15 DA20 EA08 EA15 EA18 EA20 EA25 EB08 EE05 FA08 NA08 4

Claims (24)

[Claims] 1. A composite material having a photocatalytic activity under ultraviolet / visible light, comprising a photocatalyst typified by titanium dioxide and a solid peroxide. 2. The composite material according to claim 1, wherein the titanium dioxide is a rutile type. 3. The composite material according to claim 1, wherein the particle size of titanium dioxide is 50 nm or less. 4. The composite material according to claim 1, wherein the peroxide is a powdered inorganic peroxide. 5. The composite material according to claim 1, wherein the peroxide is sparingly soluble in water. 6. The composite material according to claim 1, wherein the titanium dioxide is coated with calcium phosphate. 7. The composite material according to claim 6, wherein the calcium phosphate has photoactivity (photooxidation function). 8. The composite material according to claim 1, wherein the composite material contains a chelating component. 9. The chelate component is silicate, phosphate,
The composite material according to claim 8, which is one or more selected from the group consisting of phosphoric acid and citric acid. 10. An environmental purification method comprising using the composite material according to any one of claims 1 to 9 to decompose organic substances existing in an aqueous system or an atmospheric system under light irradiation and perform purification treatment. . 11. The environmental purification method according to claim 10, wherein the environmental purification is atmospheric purification or water purification. 12. A cleaning agent for cleaning an article, comprising the composite material according to any one of claims 1 to 9. 13. The cleaning agent according to claim 12, wherein the article is a decorative article, food, clothing, electronic component, mechanical component, or medical device. 14. An article having a photocatalytic action under ultraviolet / visible light, which is coated with the composite material according to claim 1. 15. A coating material comprising the composite material according to any one of claims 1 to 9. 16. An article having a photocatalytic action under ultraviolet / visible light, which is obtained by applying the coating composition according to claim 15. 17. A liquid agent comprising the composite material according to any one of claims 1 to 9. 18. A spray agent containing the liquid agent according to claim 17. 19. An article having a photocatalytic activity under ultraviolet / visible light, which is obtained by spraying the spray agent according to claim 18 to coat the composite material. 20. An antifouling agent comprising the composite material according to any one of claims 1 to 9. 21. An article having an antifouling effect under ultraviolet / visible light, which is coated with the antifouling agent according to claim 20. 22. A deodorant comprising the composite material according to any one of claims 1 to 9. 23. An article having a deodorizing effect under ultraviolet / visible light, which is coated with the deodorant according to claim 22. 24. A bleaching agent comprising the composite material according to any one of claims 1 to 9.