Self-cleaning coating capable of degrading tail gas and preparation method thereof

Abstract

The invention provides a self-cleaning coating capable of degrading tail gas and a preparation method thereof, and relates to the technical field of coatings. The self-cleaning coating capable of degrading the tail gas is prepared from silicone acrylic emulsion, deionized water, anatase titanium dioxide, pigment, auxiliaries, a cosolvent and silane, wherein the auxiliaries are prepared from an organic silicon defoaming agent, a styrene-maleic acid copolymer dispersing agent, a polyurethane thickening agent, a flash-rust inhibitor, a PH regulator and a base material wetting agent. According to the invention, the defects in the prior art are overcome, and the prepared coating has excellent self-cleaning performance and automobile exhaust decomposition capability.

Description

Technical Field

[0001] The invention relates to the technical field of coatings, and in particular to a self-cleaning coating capable of degrading tail gas and a preparation method thereof. Background Art

[0002] With the continuous improvement of urbanization and economic development, the per capita car ownership in my country is increasing, and the emission of automobile exhaust is also rising. Automobile exhaust has become a source of air pollution, which has a very adverse impact on the ecological environment, human health and economic development. At the same time, the improvement of urbanization has brought about an increase in the number of buildings and supporting public facilities. The sanitation and cleaning of these facilities is a time-consuming and labor-intensive task, and such facilities will be protected by coatings. Therefore, a type of coating is needed that has both self-cleaning ability and the ability to absorb automobile exhaust. Summary of the invention

[0003] In view of the deficiencies in the prior art, the present invention provides a self-cleaning coating that can degrade exhaust gas and a preparation method thereof, so that the prepared coating has both self-cleaning ability and the ability to absorb automobile exhaust gas, thereby comprehensively improving environmental protection and safety.

[0004] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0005] A self-cleaning coating capable of degrading tail gas, the self-cleaning coating is composed of the following materials in parts by weight: 40-70 parts of silicone-acrylic emulsion, 10-20 parts of deionized water, 5-20 parts of anatase titanium dioxide, 5-10 parts of pigment, 1-3 parts of auxiliary agent, 3-7 parts of cosolvent and 1-5 parts of silane.

[0006] Preferably, the auxiliary agent is composed of the following substances by weight: 0.1-0.3 parts of silicone defoamer, 0.5-2 parts of styrene maleic acid copolymer dispersant, 0.3-0.5 parts of polyurethane thickener, 0.5-1 parts of anti-flash rust agent, 0.3-0.5 parts of pH regulator, and 0.1-0.5 parts of substrate wetting agent.

[0007] Preferably, the co-solvent is composed of the following materials in parts by weight: 3-6 parts of alcohol ester and 2-3 parts of ethylene glycol.

[0008] Preferably, the silane is perfluorooctyltriethoxysilane.

[0009] Preferably, the preparation method of the self-cleaning coating comprises the following steps:

[0010] S1. Add part of the additives to part of the deionized water, perform preliminary dispersion in a disperser, then add anatase titanium dioxide and pigment and continue to disperse to obtain a titanium dioxide dispersion for use;

[0011] S2, putting the titanium dioxide dispersion into a grinding cylinder, adding zirconium beads, and grinding until the fineness is less than 20 μm to obtain a titanium dioxide slurry for standby use;

[0012] S3. Add titanium dioxide slurry to silicone acrylic emulsion, add remaining additives, co-solvents, silane and remaining deionized water at a stirring speed of 500-800 r / min, and stir evenly to obtain a self-cleaning coating that can degrade exhaust gas.

[0013] Preferably, the dispersion speed in step S1 is 1000-1500 r / min, the initial dispersion time is 5 min, and the continued dispersion time is 30 min.

[0014] Preferably, the grinding speed in step S2 is 2000-2500 r / min.

[0015] Preferably, the pH of the novel exhaust gas degradable self-cleaning coating prepared in step S3 is 7-9.

[0016] The self-cleaning coating capable of degrading exhaust gas can be used for protecting concrete and steel surfaces.

[0017] The present invention provides a self-cleaning coating capable of degrading tail gas and a preparation method thereof, which has the following advantages over the prior art:

[0018] (1) The novel self-cleaning coating capable of degrading exhaust gas provided by the present invention can significantly improve the self-cleaning ability of the coating by utilizing the low surface tension brought by silane. Ordinary dust and dirt can be easily washed away with just water;

[0019] (2) The novel self-cleaning coating for degradable tail gas provided in the present invention uses anatase nano-titanium dioxide to provide a stronger tail gas decomposition ability, because the principle of nano-titanium dioxide decomposing tail gas is to generate hole-electron pairs under ultraviolet light catalysis, thereby generating redox ability, but the generated hole-electron pairs are easy to recombine, so the photocatalytic efficiency of nano-TiO2 depends to a certain extent on the degree of recombination of the two. In the photocatalytic process, nano-TiO2 can adsorb oxygen molecules, and oxygen molecules can remove photogenerated electrons, thereby inhibiting the recombination of the two. Since rutile nano-TiO2 has a weaker adsorption capacity for molecules, its photocatalytic efficiency is relatively low; at the same time, both types of nano-TiO2 have crystal defects and dislocations, which can cause them to generate more oxygen vacancies to capture electrons, but anatase nano-TiO2 has relatively more crystal defects and dislocations, thereby having a better photocatalytic efficiency. Therefore, the novel self-cleaning coating for degradable tail gas provided by the present invention has a stronger ability to absorb tail gas;

[0020] (3) The novel self-cleaning coating for degrading tail gas provided in the present invention uses a silane coupling agent to increase the bond energy, so that the product has higher aging resistance and water resistance;

[0021] (4) The novel self-cleaning coating for degrading exhaust gas provided in the present invention can be adjusted in color using other pigments, thereby increasing decorative properties and having a wider application field. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention is clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] Embodiment 1:

[0024] Preparation of self-cleaning coating capable of degrading tail gas (raw materials are calculated by weight):

[0025] (1) Preparation of titanium dioxide dispersion: 0.7 parts of styrene maleic acid copolymer dispersant, 0.1 parts of silicone defoamer, 0.2 parts of pH regulator, and 0.2 parts of substrate wetting agent were added to 6 parts of deionized water, and dispersed on a disperser at 1000 r / min. After dispersing for 5 minutes, 18 parts of titanium dioxide were added, and the dispersion was continued for 30 minutes to obtain a titanium dioxide dispersion;

[0026] (2) Preparation of titanium dioxide slurry: Put the titanium dioxide dispersion into a grinding cylinder, add zirconium beads, and grind at a speed of 2500 r / min until the fineness is less than 20 μm to obtain titanium dioxide slurry;

[0027] (3) Preparation of self-cleaning coating: Add 50 parts of silicone acrylic emulsion to titanium dioxide slurry, add 0.2 parts of pH regulator, 0.6 parts of anti-flash rust agent, 4 parts of alcohol ester dodecahydrate, 2 parts of ethylene glycol, 2 parts of perfluorooctyl triethoxysilane, and 6 parts of deionized water at a speed of 700 r / min, stir evenly, add 0.6 parts of polyurethane thickener, adjust the viscosity to 80-90 KU to obtain a white new type of biodegradable exhaust gas self-cleaning coating, and control the pH to 8.5.

[0028] Embodiment 2:

[0029] Preparation of self-cleaning coating capable of degrading tail gas (raw materials are calculated by weight):

[0030] (1) Preparation of titanium dioxide dispersion: 1 part of styrene maleic acid copolymer dispersant, 0.1 part of silicone defoamer, 0.2 part of pH regulator, and 0.2 part of substrate wetting agent were added to 6 parts of deionized water, and dispersed on a disperser at 1000 r / min. After dispersing for 5 minutes, 15 parts of titanium dioxide and 2 parts of carbon black were added, and the dispersion was continued for 30 minutes to obtain a titanium dioxide dispersion.

[0031] (2) Preparation of titanium dioxide slurry: Put the titanium dioxide dispersion into a grinding cylinder, add zirconium beads, and grind at a speed of 2500 r / min until the fineness is less than 20 μm to obtain titanium dioxide slurry.

[0032] (3) Preparation of self-cleaning coating: Add titanium dioxide slurry to 60 silicone acrylic emulsion, add 0.2 parts of pH regulator, 0.6 parts of anti-flash rust agent, 4 parts of alcohol ester dodecahydrate, 2 parts of ethylene glycol, 2 parts of perfluorooctyl triethoxysilane, and 6 parts of deionized water at a speed of 700 r / min, stir evenly, add 0.6 parts of polyurethane thickener, adjust the viscosity to 80-90 KU to obtain a gray new type of biodegradable exhaust gas self-cleaning coating, and control the pH to 8.

[0033] Embodiment 3:

[0034] Preparation of self-cleaning coating capable of degrading tail gas (raw materials are calculated by weight):

[0035] (1) Preparation of titanium dioxide dispersion: 0.7 parts of styrene maleic acid copolymer dispersant, 0.1 parts of silicone defoamer, 0.2 parts of pH regulator, and 0.2 parts of substrate wetting agent were added to 6 parts of deionized water and dispersed on a disperser at 1000 r / min. After dispersing for 5 minutes, 12 parts of titanium dioxide and 6 parts of Permanent Red were added and dispersed for another 30 minutes to obtain a titanium dioxide dispersion.

[0036] (2) Preparation of titanium dioxide slurry Titanium dioxide dispersion was placed in a grinding cylinder, zirconium beads were added, and grinding was performed at a speed of 2500 r / min until the fineness was less than 20 μm to obtain titanium dioxide slurry.

[0037] 3. Preparation of a new type of self-cleaning coating for degradable exhaust gas: Add 55 parts of silicone-acrylic emulsion to titanium dioxide slurry, add 0.2 parts of pH regulator, 0.6 parts of anti-rust agent, 4 parts of alcohol ester dodecahydrate, 2 parts of ethylene glycol, 2 parts of perfluorooctyl triethoxysilane, and 6 parts of deionized water at a speed of 700r / min, stir well, add 0.6 parts of polyurethane thickener, adjust the viscosity to 80-90KU to obtain a red new type of self-cleaning coating for degradable exhaust gas, and control the pH to 7.5.

[0038] Detection:

[0039] 1. Referring to JG / T 304-2011 "Anti-graffiti and anti-sticking coatings for construction" (SB type), the coatings prepared in Example 1, Example 2 and Example 3 were sprayed onto the test panels and tested after curing for 7 days. The test results are shown in Table 1:

[0040] Table 1

[0041]

[0042]

[0043] It can be seen from the above examples that the self-cleaning coatings capable of degrading tail gas prepared in Examples 1-3 have good mechanical properties and excellent self-cleaning properties.

[0044] 2. According to JG / T 304-2011 "Anti-graffiti and anti-sticking coatings for buildings" (SB type), the coatings prepared in Examples 1-3 were sprayed onto test panels and tested after curing for 7 days.

[0045] The concentration of NO2 in the reaction box was detected by a gas detection alarm, and the concentration change of NO2 within 60 minutes was recorded and compared with the initial concentration to calculate the degradation efficiency of NO2. The temperature and humidity during the reaction were controlled by a thermohygrometer combined with a heating and humidifying device. Initial NO2 concentration: 20ppm, temperature 25℃, humidity 50%, illumination 3000lx. The change of NO2 concentration of degraded automobile exhaust over time is shown in Table 2.

[0046] Table 2

[0047] Degradation time 10min 20min 30min 40min 50min 60min Example 1 46.2 68.3 78.6 81.4 81.6 81.7 Example 2 43.3 64.2 74.6 78.2 78.3 78.3 Example 3 40.2 60.3 70.9 74.5 74.7 74.8

[0048] It can be seen from the above embodiments that the exhaust gas purification performance of the new self-cleaning coating for degradable exhaust gas involved in the present invention is lost as the titanium dioxide content in the coating decreases, but the overall NO2 degradation rate in 60 minutes still reaches more than 75%, which shows that the coating has significant DR exhaust gas absorption capacity.

[0049] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A self-cleaning coating capable of degrading tail gas, characterized in that: The self-cleaning coating is composed of the following materials in parts by weight: 40-70 parts of silicone-acrylic emulsion, 10-20 parts of deionized water, 5-20 parts of anatase titanium dioxide, 5-10 parts of pigment, 1-3 parts of auxiliary agent, 3-7 parts of cosolvent and 1-5 parts of silane.

2. The self-cleaning coating according to claim 1, characterized in that: The auxiliary agent is composed of the following substances by weight: 0.1-0.3 parts of organic silicon defoamer, 0.5-2 parts of styrene maleic acid copolymer dispersant, 0.3-0.5 parts of polyurethane thickener, 0.5-1 parts of anti-flash rust agent, 0.3-0.5 parts of pH regulator, and 0.1-0.5 parts of substrate wetting agent.

3. The self-cleaning coating according to claim 1, characterized in that: The co-solvent is composed of the following materials in parts by weight: 3-6 parts of alcohol ester and 2-3 parts of ethylene glycol.

4. The self-cleaning coating according to claim 1, characterized in that: The silane is perfluorooctyltriethoxysilane.

5. A method for preparing a self-cleaning coating capable of degrading tail gas as claimed in any one of claims 1 to 4, characterized in that: The preparation method comprises the following steps: S1. Add part of the additives to part of the deionized water, perform preliminary dispersion in a disperser, then add anatase titanium dioxide and pigment and continue to disperse to obtain a titanium dioxide dispersion for use; S2, putting the titanium dioxide dispersion into a grinding cylinder, adding zirconium beads, and grinding until the fineness is less than 20 μm to obtain a titanium dioxide slurry for standby use; S3. Add titanium dioxide slurry to silicone acrylic emulsion, add remaining additives, co-solvents, silane and remaining deionized water at a stirring speed of 500-800 r / min, and stir evenly to obtain a self-cleaning coating that can degrade exhaust gas.

6. The preparation method according to claim 5, characterized in that: The dispersion speed in step S1 is 1000-1500 r / min, the initial dispersion time is 5 min, and the continued dispersion time is 30 min.

7. The preparation method according to claim 5, characterized in that: The grinding speed in step S2 is 2000-2500 r / min.

8. The preparation method according to claim 5, characterized in that: The pH value of the novel self-cleaning coating capable of degrading tail gas prepared in step S3 is 7-9.

9. A self-cleaning coating capable of degrading tail gas as claimed in any one of claims 1 to 4, used for protecting concrete and steel surfaces.

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