Photocatalyst coating liquid and spray device

Abstract

To provide a photocatalyst coating liquid that forms a photocatalyst layer capable of sufficiently generating reactive oxygen species, regardless of gas humidity.SOLUTION: A photocatalyst coating liquid includes a dispersion medium, photocatalyst particles, and humidity conditioner particles. The photocatalyst particles and humidity conditioner particles are dispersed in the dispersion medium.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a photocatalytic coating liquid and a spray device. [Background technology]

[0002] The air purifying device described in Patent Document 1 includes a main body, a lamp, a deodorizing filter, and a fan. The deodorizing filter includes a photocatalyst arranged around the lamp. The lamp activates the photocatalyst. The fan sends air to the deodorizing filter. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-78058 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the air purifier described in Patent Document 1, when the humidity of the air flowing inside the main body is too high or too low, the light from the lamp may not be able to fully activate the catalytic action of the photocatalyst, and therefore, it may not be possible to generate a sufficient amount of highly oxidizing active oxygen.

[0005] An object of the present invention is to provide a photocatalyst coating liquid and a spray device that can form a photocatalyst layer that can generate sufficient active oxygen regardless of the humidity of the gas. [Means for solving the problem]

[0006] According to a first aspect of the present application, a photocatalyst coating liquid includes a dispersion medium, photocatalyst particles, and humidity conditioner particles, the photocatalyst particles and the humidity conditioner particles being dispersed in the dispersion medium.

[0007] According to a second aspect of the present application, a spray product includes the above-mentioned photocatalyst coating liquid and a sprayer. The sprayer is configured to spray the photocatalyst coating liquid. Effect of the Invention

[0008] According to the photocatalyst coating liquid and spray device of the present invention, a photocatalyst layer capable of generating sufficient active oxygen can be formed regardless of the humidity of the gas. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 shows a spray device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference characters and description thereof will not be repeated.

[0011] A spray device according to an embodiment of the present invention will be described with reference to Fig. 1. Fig. 1 is a diagram showing a spray device according to the present embodiment. As shown in Fig. 1, the spray device 100 includes a sprayer 10 and a container 20.

[0012] The container 20 contains the photocatalyst coating liquid LL. In detail, the container 20 is held by the user.

[0013] The sprayer 10 is provided in the container 20. Specifically, the sprayer 10 is provided on the upper part of the container 20. Specifically, the sprayer 10 is attached to the container 20 in a detachable manner.

[0014] The sprayer 10 sprays the photocatalyst coating liquid LL contained in the container 20. The sprayer 10 is formed with a spray nozzle. The spray nozzle communicates the inside and outside of the container 20. In detail, the user operates the sprayer 10 to spray the photocatalyst coating liquid LL toward the target object. As a result, a photocatalyst layer is formed on the surface of the target object. The target object is, for example, a daily necessities. The photocatalyst coating liquid LL sprayed from the spray nozzle is quickly dried in a sprayed state, and is granulated into fine and stable powder particles.

[0015] Here, the photocatalyst coating liquid LL will be explained. The photocatalyst coating liquid LL contains a dispersion medium, photocatalyst particles, and humidity conditioning material particles.

[0016] The dispersion medium preferably contains water. The dispersion medium more preferably further contains alcohol. Examples of the alcohol include ethanol. Specifically, the dispersion medium particularly preferably contains 40 parts by mass or more and 70 parts by mass or less of alcohol per 100 parts by mass of water.

[0017] Examples of photocatalyst particles include titanium dioxide particles and tungsten oxide particles, and more preferably tungsten oxide particles. The volume average diameter of the photocatalyst particles is preferably 100 nm or more and 500 nm or less, and more preferably 100 nm or more and 300 nm or less.

[0018] The photocatalyst particles are dispersed in a dispersion medium. The content of the photocatalyst particles is preferably 0.3% by mass or more and 5.0% by mass or less, and more preferably 0.5% by mass or more and 3.0% by mass or less.

[0019] When a photocatalyst layer is formed and the photocatalyst particles are irradiated with light, the catalytic action of the photocatalyst particles is activated. As a result, the H 2 O (water molecule) is decomposed and active oxygen is generated. Active oxygen is a mixture of [·OH] (hydroxyl radical) and O 2 - (superoxide ion).

[0020] For example, [·OH] (hydroxyl radical) and O 2 - When released into the air, [·OH] (hydroxyl radical) and O 2 - (Superoxide ion) is an active species with high oxidizing power, and is capable of decomposing volatile organic compounds, etc.

[0021] The humidity control particles adjust the humidity of the gas. The humidity control particles preferably contain at least one selected from silica gel, zeolite, sepiolite, calcium carbonate, calcium hydroxide, coal, vegetable charcoal, activated carbon, and diatomaceous earth. As a result, the photocatalyst particles can have a catalytic effect that lasts as long as the photocatalyst particles.

[0022] The volume average diameter of the humidity control material particles is preferably 1000 nm or more and 5000 nm or less, more preferably 2000 nm or more and 4000 nm or less. If the volume average diameter of the humidity control material particles is less than 1000 nm, the surface of the photocatalyst particles may be covered, and the photocatalyst particles may not be irradiated with light. On the other hand, if the volume average diameter of the humidity control material particles is more than 5000 nm, the humidity of the gas may not be sufficiently adjusted.

[0023] The humidity control particles are dispersed in a dispersion medium. The content of the humidity control particles is preferably 0.5% by mass or more and 5.0% by mass or less, and more preferably 1.0% by mass or more and 3.0% by mass or less. If the content of the humidity control particles exceeds 5.0% by mass, the surface of the photocatalyst particles may be covered, and the photocatalyst particles may not be irradiated with light. On the other hand, if the content of the humidity control particles is less than 0.5% by mass, the humidity of the gas may not be sufficiently adjusted.

[0024] When a photocatalyst layer is formed, the air around the photocatalyst layer comes into contact with the humidity-regulating material particles, and the humidity of the air is adjusted. Specifically, when the air humidity is high, the H 2O (water molecules) are adsorbed to the humidity-adjusting material particles. On the other hand, when the humidity of the sucked-in air is low, H 2 O (water molecule) is released into the air.

[0025] As described above with reference to Fig. 1, the photocatalyst coating liquid LL and the spray device 100 according to this embodiment can form a photocatalyst layer capable of generating sufficient active oxygen regardless of the humidity of the air. Therefore, the decomposition speed of decomposing volatile organic compounds and the like can be improved.

[0026] Next, an example of a method for producing the photocatalyst coating liquid LL will be described. The method for producing the photocatalyst coating liquid LL includes (A) a photocatalyst particle adding step, (B) an alcohol adding step, (C) a humidity conditioner particle preparing step, and (D) a humidity conditioner particle adding step.

[0027] (A) Photocatalyst particle addition process Photocatalyst particles are added to water and dispersed to prepare a dispersion liquid. As a method for dispersing photocatalyst particles in water, for example, a method using a wet dispersing machine can be mentioned. As a dispersing machine, for example, an ultrasonic dispersing machine, a colloid mill, a bead mill, etc. can be mentioned.

[0028] (B) Alcohol addition step The mixture is prepared by adding alcohol to the dispersion and mixing. As a method for mixing the alcohol into the dispersion, for example, a method using a liquid mixer can be mentioned. If the liquid mixer is equipped with a stirring blade or the like, the composition of the mixture can be made more uniform.

[0029] (C) Humidity-conditioning material particle production process The humidity-conditioning material is pulverized using a pulverizer to produce humidity-conditioning material particles. The volume average diameter of the humidity-conditioning material particles is preferably 1000 nm or more and 5000 nm or less. Examples of the pulverizer include a cutter mill, a roller mill, and a ball mill.

[0030] (D) Humidity control particle addition process The photocatalyst coating liquid LL is prepared by adding and mixing the humidity-conditioning material particles to the mixed liquid. For example, a method of mixing the humidity-conditioning material particles into the mixed liquid may be carried out using a liquid mixer. If the liquid mixer is equipped with a stirring blade or the like, the composition of the photocatalyst coating liquid LL can be made more uniform.

[0031] The embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to the above embodiments, and can be implemented in various aspects without departing from the gist of the present invention. In addition, various inventions can be formed by appropriately combining multiple components disclosed in the above embodiments. For example, some components may be deleted from all components shown in the embodiments. The drawings are mainly shown schematically for ease of understanding, and the number of each component shown may differ from the actual number due to the convenience of drawing. In addition, each component shown in the above embodiments is an example, is not particularly limited, and various modifications are possible within a range that does not substantially deviate from the effects of the present invention. EXAMPLES

[0032] The present invention will be described in more detail below using examples, but the present invention is not limited to the scope of the examples.

[0033] <Example 1> (A) Photocatalyst particle addition process 21% by mass of tungsten oxide particles having a volume average diameter of 200 nm were added to water and dispersed using an ultrasonic disperser to prepare a dispersion liquid.

[0034] (B) Alcohol addition step Ethanol was added to the dispersion liquid, and the mixture was mixed using a liquid mixer to prepare a mixed liquid.

[0035] (C) Humidity-conditioning material particle production process Silica gel type B (Fujigel Sangyo Co., Ltd., product type FB) was pulverized in a mortar to produce silica gel particles having a volume average diameter of 3000 nm.

[0036] (D) Humidity control particle addition process Silica gel particles having a volume average of 3000 nm were added to the mixed liquid and mixed using a liquid mixer to prepare 100 ml of the photocatalyst coating liquid according to Example 1. The photocatalyst coating liquid according to Example 1 contained 2.0 mass % tungsten oxide particles, 2.0 mass % silica gel particles, 10 mass % ethanol, and water.

[0037] <Example 2> The photocatalyst coating liquid of Example 2 was produced in the same manner as the photocatalyst coating liquid of Example 1, except that instead of containing 2.0 mass% of tungsten oxide particles having a volume average diameter of 200 nm and 2.0 mass% of silica gel particles having a volume average diameter of 3000 nm, the photocatalyst coating liquid of Example 2 contained 5.0 mass% of tungsten oxide particles having a volume average diameter of 500 nm and 5.0 mass% of silica gel particles having a volume average diameter of 5000 nm.

[0038] <Example 3> A photocatalyst coating solution according to Example 3 was produced in the same manner as the photocatalyst coating solution according to Example 1, except that instead of containing 2.0 mass% tungsten oxide particles having a volume average diameter of 200 nm and 2.0 mass% silica gel particles having a volume average diameter of 3000 nm, the photocatalyst coating solution according to Example 3 contained 0.5 mass% tungsten oxide particles having a volume average diameter of 100 nm and 0.5 mass% silica gel particles having a volume average diameter of 1000 nm.

[0039] <Example 4> The photocatalyst coating liquid of Example 4 was produced in the same manner as the photocatalyst coating liquid of Example 1, except that instead of containing 2.0 mass% of tungsten oxide particles having a volume average diameter of 200 nm and 2.0 mass% of silica gel particles having a volume average diameter of 3000 nm, the photocatalyst coating liquid of Example 4 contained 10 mass% of tungsten oxide particles having a volume average diameter of 200 nm and 10 mass% of silica gel particles having a volume average diameter of 3000 nm.

[0040] <Example 5> The photocatalyst coating liquid of Example 5 was produced in the same manner as the photocatalyst coating liquid of Example 1, except that instead of containing 2.0 mass% of tungsten oxide particles having a volume average diameter of 200 nm and 2.0 mass% of silica gel particles having a volume average diameter of 3000 nm, the photocatalyst coating liquid of Example 5 contained 0.1 mass% of tungsten oxide particles having a volume average diameter of 200 nm and 2.0 mass% of silica gel particles having a volume average diameter of 3000 nm.

[0041] <Example 6> The photocatalyst coating liquid of Example 6 was produced in the same manner as the photocatalyst coating liquid of Example 1, except that instead of containing 2.0 mass% of tungsten oxide particles having a volume average diameter of 200 nm and 2.0 mass% of silica gel particles having a volume average diameter of 3000 nm, the photocatalyst coating liquid of Example 6 contained 2 mass% of tungsten oxide particles having a volume average diameter of 200 nm and 10 mass% of silica gel particles having a volume average diameter of 3000 nm.

[0042] <Example 7> The photocatalyst coating liquid of Example 7 was produced in the same manner as the photocatalyst coating liquid of Example 1, except that instead of containing 2.0 mass% of tungsten oxide particles having a volume average diameter of 200 nm and 2.0 mass% of silica gel particles having a volume average diameter of 3000 nm, the photocatalyst coating liquid of Example 7 contained 2 mass% of tungsten oxide particles having a volume average diameter of 200 nm and 0.1 mass% of silica gel particles having a volume average diameter of 3000 nm.

[0043] <Comparative Example 1> The photocatalyst coating liquid of Comparative Example 1 was produced in the same manner as the photocatalyst coating liquid of Example 1, except that, instead of containing 2.0 mass % of silica gel particles having a volume average diameter of 3000 nm, no silica gel particles were contained.

[0044] <Comparative Example 2> A photocatalyst coating liquid according to Comparative Example 2 was produced in the same manner as the photocatalyst coating liquid according to Example 1, except that, instead of containing 2.0 mass % of tungsten oxide particles having a volume average diameter of 200 nm, no tungsten oxide particles were contained.

[0045] <Evaluation of photocatalytic performance> The photocatalyst coating liquid according to Example 1 to Example 7 and the photocatalyst coating liquid according to Comparative Example 1 and Comparative Example 2 were evenly dropped onto a 125 mm x 125 mm cellulose fabric using a 2 g dropper. The cellulose fabric was dried in a 40°C blower dryer and pre-irradiated with a 4500 lux blue LED for 48 hours to prepare a test sample. Next, the test sample was placed in a 1 L gas bag and 100 ppm of acetaldehyde gas was placed in it. After irradiating the gas bag with a 4500 lux blue LED for 5 hours, the acetaldehyde gas concentration in the gas bag was measured with a detector tube. The gas remaining rate was calculated based on the following formula (1). (Gas residual rate) = (Gas concentration after 5 hours) / (Initial gas concentration 100 ppm) (1)

[0046] The tests were carried out in a low humidity environment (5°C, 5%), a normal environment (25°C, 50%), and a high humidity environment (30°C, 80%), and the gas remaining rate was evaluated according to the following criteria. The evaluation results are shown in Table 1. ◎: Less than 5% ○: 5% or more but less than 20% △: 20% or more but less than 50% ×: 50% or more

[0047] [Table 1]

[0048] From the above, in the photocatalyst coating liquids according to Examples 1 to 7, the gas residual rate was less than 50% regardless of the air humidity. On the other hand, in the photocatalyst coating liquid according to Comparative Example 1, since there were no humidity-regulating material particles, the gas residual rate was 50% or more in a high humidity environment (30°C, 80%). Moreover, in the photocatalyst coating liquid according to Comparative Example 2, since there were no photocatalyst particles, gas decomposition did not proceed and the gas residual rate was 50% or more.

[0049] In the photocatalyst coating liquids of Examples 1 to 3, the content of photocatalyst particles was 0.5% by mass or more and 5.0% by mass or less, and the content of humidity-regulating material particles was 0.5% by mass or more and 5.0% by mass or less, so that the gas residual rate was less than 5%. [Industrial Applicability]

[0050] The present invention can be used in the fields of photocatalyst coating solutions and spray devices. [Explanation of symbols]

[0051] 10 sprayer 20 containers 100 Spray Equipment LL photocatalyst coating liquid

Claims

1. A dispersion medium; Photocatalyst particles and humidity control material particles dispersed in the dispersion medium. A photocatalytic coating solution comprising:

2. The photocatalyst coating solution according to claim 1 , wherein the photocatalyst particles are tungsten oxide particles.

3. the humidity-conditioning particles contain at least one selected from the group consisting of silica gel, zeolite, sepiolite, calcium carbonate, calcium hydroxide, coal, vegetable charcoal, activated carbon, and diatomaceous earth; The photocatalyst coating liquid according to claim 1 , wherein the dispersion medium contains water.

4. The content of the photocatalyst particles is 0.5% by mass or more and 5.0% by mass or less, The photocatalyst coating liquid according to claim 1 , wherein the content of the humidity conditioning particles is 0.5% by mass or more and 5.0% by mass or less.

5. The volume average diameter of the photocatalyst particles is 100 nm or more and 500 nm or less, The photocatalyst coating liquid according to claim 1 , wherein the volume average diameter of the humidity conditioning material particles is 1000 nm or more and 5000 nm or less.

6. The photocatalyst coating liquid according to any one of claims 1 to 5, A sprayer provided to spray the photocatalyst coating liquid; A spray product comprising:

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