Weather-resistant self-cleaning coating as well as preparation method and application thereof

Abstract

The invention discloses a weather-resistant self-cleaning coating as well as a preparation method and application thereof, and belongs to the technical field of coating preparation. The self-cleaning coating is prepared from 50-70 parts of deionized water, 20-28 parts of protective glue, 20-35 parts of hydroxyethyl cellulose, 18-25 parts of latex, 5-8 parts of a preservative, 3-7 parts of a dispersing agent, 4-7 parts of a wetting agent, 1-2 parts of a defoaming agent, 3-5 parts of pigment filler, 3-5 parts of a coalescing agent and 2-4 parts of a thickening agent. The latex is composed of silicone acrylic latex and pure acrylic latex. By adding the raw materials with nano structures, a concave-convex shape similar to a lotus leaf is formed in the drying and film-forming process of the coating, so that dust particles are attached to the surface of the coating and are in a suspended state, and meanwhile, the contact angle between water and the surface of the coating is increased, so that water drops can roll down on the surface of the coating. In addition, hydrophobic substances are introduced into the solution, so that the coating is automatically layered in the drying and film forming process, a hydrophobic layer is enriched on the surface of the coating, it is guaranteed that the adsorbed polluting particles are separated from the surface of the coating under the scouring of wind and rain, and the self-cleaning purpose is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of coating preparation, and in particular relates to a weather-resistant self-cleaning coating and a preparation method and application thereof. Background Art

[0002] For the purpose of decoration, various coatings are often scraped and applied on the surface of outdoor walls. However, since the exterior walls are placed in an open-air environment, they will inevitably be exposed to the sun and rain, which will increase the number of stains on the exterior walls. Therefore, they also need to be wiped manually, but this method is time-consuming and labor-intensive, and requires special staff to maintain it. In addition, there are certain personal safety concerns when working at high altitudes. In addition, in the sun and rain environment, the performance of the coating will deteriorate, and even worse, the exterior wall coating will crack and fall off, exposing the exterior wall to the outside, which will not achieve a beautiful decorative effect, and will also cause sunlight, rain, etc. to directly act on the wall, resulting in a shortened wall service life. Based on the above problems, it is urgent to develop a self-cleaning coating with strong weather resistance. Summary of the invention

[0003] In view of this, the purpose of the present invention is to provide a weather-resistant self-cleaning coating and a preparation method and application thereof, so as to solve the problem of poor performance of current products.

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] The present invention provides a weather-resistant self-cleaning coating, which comprises, by weight, 50-70 parts of deionized water, 20-28 parts of protective glue, 20-35 parts of hydroxyethyl cellulose, 18-25 parts of latex, 5-8 parts of preservatives, 3-7 parts of dispersants, 4-7 parts of wetting agents, 1-2 parts of defoamers, 3-5 parts of pigments and fillers, 3-5 parts of film-forming aids, and 2-4 parts of thickeners;

[0006] The latex consists of silicone-acrylic latex and pure acrylic latex.

[0007] Furthermore, the protective glue is modified lithium magnesium silicate; and the pigment filler is titanium dioxide.

[0008] Furthermore, the preservative is at least one of carbamate and new carbendazim; the dispersant is at least one of sodium oleate, carboxylate, sulfate ester, sulfonate, quaternary ammonium salt, and pyridinium salt; the wetting agent is ethoxylated polyether; the defoaming agent is one or more of polymerized siloxane and dimethyl silicone oil; the film-forming aid is composed of at least one of propylene glycol, dodecyl alcohol ester, and hexanediol butyl ether acetate; the thickener is at least one of sodium polyacrylate, organic bentonite, and polyacrylamide.

[0009] Furthermore, a method for preparing a weather-resistant self-cleaning coating is also provided, comprising the following steps:

[0010] S1. Add protective glue into deionized water and disperse to obtain protective glue solution;

[0011] S2. Add hydroxyethyl cellulose to deionized water under stirring conditions, and then add dispersant, wetting agent, defoamer, pigment and filler after stirring;

[0012] S3, reduce the speed, add protective glue solution, latex, film-forming aid, defoamer, preservative and continue stirring to obtain a basic coating solution;

[0013] S4, under stirring conditions, adding latex, film-forming aid, defoamer, preservative, and thickener to deionized water, and stirring evenly to obtain a continuous phase solution;

[0014] S5. Mix the continuous phase solution and the base coating solution and stir them evenly to obtain a weather-resistant self-cleaning coating.

[0015] Furthermore, in step S1, the stirring speed is 800-1200 r / min, and the stirring time is 20-30 min.

[0016] Furthermore, in step S2, when hydroxyethyl cellulose is added, the stirring rate is 200-300 r / min, and the stirring time is 2-3 min; after adding the dispersant, wetting agent, defoamer, color filler, and multifunctional additive, the stirring rate is 1200-1500 r / min, and the stirring time is 20-30 min.

[0017] Furthermore, in step S3, the stirring rate after the rate reduction is 600-800 r / min, and the stirring time after adding the protective glue solution, latex, film-forming aid, propylene glycol, defoaming agent and preservative is 5-10 min.

[0018] Furthermore, in step S4, the stirring rate is 600-800 r / min, and the stirring time is 10-20 min.

[0019] Furthermore, the weather-resistant self-cleaning paint is suitable for painting and scraping on the exterior walls of buildings.

[0020] The beneficial effects of the present invention are:

[0021] 1. The preservative used in the present invention has a strong inhibitory effect on molds, bacteria, yeasts, grape spores, etc., can effectively prevent the occurrence of yellowing, decay, cracking and other phenomena on the surface of the coating, effectively protect the quality of water-based coatings, and prevent the coatings from deteriorating during storage and use. The magnesium aluminum silicate used as a protective glue can be a delayed water-based ultra-fast rheological additive, has good storage stability and no post-thickening phenomenon, significantly improves the water resistance and stability of the coating, and ensures the stability and weather resistance of the coating. The wetting agent of the present invention can control the adhesion of the coating surface, improve the flow, leveling, and recoating of the coating, and does not affect the glossiness, promotes the liquid to wet the solid surface or disperse the solid particles, and the hydrophilic and hydrophobic parts in the molecular structure of the wetting agent interact with water and the solid phase respectively, so that the droplets are more likely to spread on the solid surface and form a stable film, thereby increasing the contact area of ​​the solid-liquid interface, reducing the agglomeration between particles, and significantly improving the wettability of the liquid and the dispersibility of the solid particles. Hydroxyethyl cellulose has the functions of thickening, suspending, bonding, emulsifying, film-forming stability, dispersing, retaining water and protecting colloids. The role of film-forming aids in coatings is to improve the film-forming properties of coatings, ensure that the coatings can form a uniform and smooth coating after construction, reduce the minimum film-forming temperature of the coatings, and improve the fluidity and wettability of the coatings, thereby improving the construction performance of the coatings and the appearance quality of the final coatings. Film-forming aids can also enhance the water resistance and chemical resistance of the coatings and extend the service life of the coatings. Titanium dioxide can provide whiteness and hiding power for coatings.

[0022] 2. In the present invention, by adding raw materials with nanostructures, a concave-convex morphology similar to a lotus leaf is formed during the drying and film-forming process of the coating, so that dust particles are attached to the surface of the coating in a suspended state, and at the same time, the contact angle between water and the coating surface is increased, which is conducive to the rolling of water droplets on the coating surface. In addition, a hydrophobic substance is introduced into the solution, so that the coating is automatically stratified during the drying and film-forming process, thereby enriching a hydrophobic layer on the coating surface, further ensuring that the accumulated or adsorbed polluting particles are separated from the coating surface under the scouring of wind and rain, achieving the purpose of self-cleaning. The components in the coating can react chemically with pollutants to decompose them into harmless substances or substances that are more easily washed away by water.

[0023] 3. In the present invention, due to the addition of weather-resistant raw materials such as protective glue and latex, the coating has excellent weather resistance and can maintain the integrity and aesthetics of the coating under adverse climatic conditions. Through the combination of nanotechnology and self-stratification principle, the wet coating of the present invention has excellent self-cleaning performance, can automatically remove dust and pollutants attached to the surface of the coating, and reduce the workload of cleaning and maintenance. The coating of the present invention does not contain harmful substances, does not pollute the environment, meets national environmental protection requirements and relevant standards, and is a green and environmentally friendly coating product. In addition, the coating of the present invention can be added with different color pastes and color fillers to meet the needs of different consumers, while maintaining the gloss and brightness of the wall, making the wall beautiful as a whole and enhancing the appearance quality of the building. The coating of the present invention has good durability, is not easy to fall off and peel off, and can maintain a long-term cleaning effect and aesthetics.

[0024] Other advantages, objectives and features of the present invention will be described in the following description and will be apparent to those skilled in the art to some extent, or those skilled in the art may be taught from the practice of the present invention. The objectives and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to make the purpose, technical solution and beneficial effects of the invention clearer, the present invention provides the following drawings for illustration:

[0026] Figure 1 is a process flow chart of the present invention;

[0027] Figure 2 It is a schematic diagram of the use of the finished product of the present invention. DETAILED DESCRIPTION

[0028] like Figure 1 , Figure 2 As shown, the present invention provides a method for preparing a weather-resistant self-cleaning coating.

[0029] Example 1

[0030] S1. Add 25 parts of modified lithium magnesium silicate to 20 parts of deionized water, stir at 1000 r / min for 25 minutes, and stir evenly to obtain a protective glue solution;

[0031] S2, at a speed of 250r / min, add 28 parts of hydroxyethyl cellulose to 15 parts of deionized water and stir for 2 minutes, then add 1.5 parts of a dispersant composed of a carboxylate, a sulfate ester salt, and a sulfonate, 2 parts of an ethoxylated polyether, 0.5 parts of a polymerized siloxane, and 4 parts of titanium dioxide, increase the speed to 1350r / min and continue stirring for 25 minutes;

[0032] S3, the speed is reduced to 700r / min, and then a protective glue solution, 12 parts of pure acrylic latex, 2 parts of a film-forming aid composed of propylene glycol and dodecyl alcohol ester, 1 part of dimethyl silicone oil, and 3 parts of urethane are added and stirred continuously to obtain a basic coating solution;

[0033] S4, under stirring conditions, add 10 parts of silicone acrylic latex, 2 parts of hexanediol butyl ether acetate, 0.5 parts of polymerized siloxane, 2 parts of new carbendazim, 2 parts of sodium polyacrylate and a thickener consisting of polyacrylamide to 20 parts of deionized water, and stir evenly to obtain a continuous phase solution;

[0034] S5. Mix the continuous phase solution with the base coating solution, and stir at 600 r / min for 30 min until uniform, to obtain a weather-resistant self-cleaning coating.

[0035] Example 2

[0036] S1. Add 20 parts of modified lithium magnesium silicate to 25 parts of deionized water, stir at 1000 r / min for 25 minutes, and stir evenly to obtain a protective glue solution;

[0037] S2, at a speed of 250r / min, add 34 parts of hydroxyethyl cellulose to 13 parts of deionized water and stir for 2 minutes, then add 2.5 parts of a dispersant consisting of a carboxylate, a sulfate ester salt, and a sulfonate, 3 parts of an ethoxylated polyether, 0.7 parts of a polymerized siloxane, and 3 parts of titanium dioxide, increase the speed to 1350r / min and continue stirring for 25 minutes;

[0038] S3, the speed is reduced to 700r / min, and then a protective glue solution, 8 parts of pure acrylic latex, 2.5 parts of a film-forming aid composed of propylene glycol and dodecyl alcohol ester, 0.8 parts of dimethyl silicone oil, and 4.5 parts of carbamate are added and stirred continuously to obtain a basic coating solution;

[0039] S4, under stirring conditions, add 15 parts of silicone acrylic latex, 2 parts of hexanediol butyl ether acetate, 0.5 parts of polymerized siloxane, 1.5 parts of new carbendazim, 4 parts of sodium polyacrylate and a thickener consisting of polyacrylamide to 20 parts of deionized water, and stir evenly to obtain a continuous phase solution;

[0040] S5. Mix the continuous phase solution with the base coating solution, and stir at 600 r / min for 30 min until uniform, to obtain a weather-resistant self-cleaning coating.

[0041] The difference between Example 2 and Example 1 is that the components of the raw materials are different, but both are within the scope of the present invention.

[0042] Example 3

[0043] S1. Add 28 parts of modified lithium magnesium silicate to 28 parts of deionized water, stir at 1000 r / min for 25 min, and stir evenly to obtain a protective glue solution;

[0044] S2, at a speed of 250r / min, add 35 parts of hydroxyethyl cellulose to 20 parts of deionized water and stir for 2 minutes, then add 4 parts of dispersant composed of carboxylate, sulfate ester salt, sulfonate, 3.5 parts of ethoxylated polyether, 1 part of polymerized siloxane, 5 parts of titanium dioxide, increase the speed to 1350r / min and continue stirring for 25 minutes;

[0045] S3, the speed is reduced to 700r / min, and then a protective glue solution, 8 parts of pure acrylic latex, 2.8 parts of a film-forming aid composed of propylene glycol and dodecyl alcohol ester, 0.5 parts of dimethyl silicone oil, and 3 parts of carbamate are added and stirred continuously to obtain a basic coating solution;

[0046] S4, under stirring conditions, add 15 parts of silicone acrylic latex, 2.2 parts of hexanediol butyl ether acetate, 0.5 parts of polymerized siloxane, 4 parts of new carbendazim, 4 parts of sodium polyacrylate and a thickener consisting of polyacrylamide to 15 parts of deionized water, and stir evenly to obtain a continuous phase solution;

[0047] S5. Mix the continuous phase solution with the base coating solution, and stir at 600 r / min for 30 min until uniform, to obtain a weather-resistant self-cleaning coating.

[0048] The difference between Example 3 and Example 1 is that the components of the raw materials are different, but both are within the scope of the present invention.

[0049] Example 4

[0050] S1. Add 25 parts of modified lithium magnesium silicate to 20 parts of deionized water, stir at 1000 r / min for 25 minutes, and stir evenly to obtain a protective glue solution;

[0051] S2, at a speed of 250r / min, add 28 parts of hydroxyethyl cellulose to 15 parts of deionized water and stir for 2 minutes, then add 1.5 parts of a dispersant consisting of a quaternary ammonium salt and a pyridinium salt, 2 parts of an ethoxylated polyether, 0.5 parts of a defoamer consisting of dimethyl silicone oil and a polymerized siloxane, and 4 parts of titanium dioxide, increase the speed to 1350r / min and continue stirring for 25 minutes;

[0052] S3, the speed is reduced to 700r / min, and then a protective glue solution, 15 parts of latex composed of pure acrylic latex and silicone acrylic latex, 2 parts of film-forming aids composed of propylene glycol and dodecyl alcohol ester, 1 part of a defoaming agent composed of dimethyl silicone oil and polymerized siloxane, and 3 parts of a preservative composed of carbamate and a new type of carbendazim are added, and stirring is continued to obtain a basic coating solution;

[0053] S4, under stirring conditions, add 10 parts of silicone acrylic latex, 2 parts of hexanediol butyl ether acetate, 0.5 parts of a defoamer consisting of dimethyl silicone oil and polysiloxane, 2 parts of a preservative consisting of a new type of carbendazim and a carbamate, and 2 parts of a thickener consisting of sodium polyacrylate and polyacrylamide to 20 parts of deionized water, and stir to obtain a continuous phase solution;

[0054] S5. Mix the continuous phase solution with the base coating solution, and stir at 600 r / min for 30 min until uniform, to obtain a weather-resistant self-cleaning coating.

[0055] The difference between Example 4 and Example 1 is that the addition of various materials has changed, but all are within the scope of the present invention.

[0056] In order to verify the superiority of the raw materials, proportions and methods of the present invention, comparative examples 1 to 3 are set up here.

[0057] Comparative Example 1

[0058] S1. Add 25 parts of modified lithium magnesium silicate, 28 parts of hydroxyethyl cellulose, 1.5 parts of dispersant consisting of carboxylate, sulfate ester and sulfonate, 2 parts of ethoxylated polyether, 1 part of polymerized silicone, 4 parts of titanium dioxide, 24 parts of pure acrylic latex, 4 parts of film-forming aid consisting of propylene glycol and dodecyl alcohol ester, 4 parts of carbamate, 2 parts of thickener consisting of sodium polyacrylate and polyacrylamide to 70 parts of deionized water, stir at 800 / min for 40 minutes to obtain the coating.

[0059] The difference between Comparative Example 1 and Example 1 is that the preparation method of the present invention is not adopted, and all the materials are directly added at one time without giving the materials sufficient reaction time.

[0060] Comparative Example 2

[0061] S1. Add 28 parts of hydroxyethyl cellulose to 15 parts of deionized water at a speed of 250 r / min and stir for 2 min. Then add 1.5 parts of a dispersant composed of carboxylate, sulfate, and sulfonate, 2 parts of ethoxylated polyether, 0.5 parts of polymerized siloxane, and 4 parts of titanium dioxide. Increase the speed to 1350 r / min and continue stirring for 25 min.

[0062] S2, the speed is reduced to 700r / min, 12 parts of pure acrylic latex, 2 parts of film-forming aids composed of propylene glycol and dodecyl alcohol ester, 1 part of dimethyl silicone oil, and 3 parts of urethane are stirred continuously to obtain a basic coating solution;

[0063] S3, under stirring conditions, add 10 parts of silicone acrylic latex, 2 parts of hexanediol butyl ether acetate, 0.5 parts of polymerized siloxane, 2 parts of new carbendazim, 2 parts of sodium polyacrylate and a thickener consisting of polyacrylamide to 20 parts of deionized water, and stir evenly to obtain a continuous phase solution;

[0064] S4. Mix the continuous phase solution with the base coating solution, and stir at 600 r / min for 30 min until the mixture is uniform to obtain the coating.

[0065] The difference between Comparative Example 2 and the embodiment is that no protective glue solution is prepared.

[0066] Comparative Example 3

[0067] S1. Add 12 parts of modified lithium magnesium silicate to 40 parts of deionized water, stir at 1000 r / min for 25 minutes, and stir evenly to obtain a protective glue solution;

[0068] S2. Add 28 parts of hydroxyethyl cellulose to 30 parts of deionized water at a speed of 250 r / min and stir for 2 min. Then add 3 parts of a dispersant consisting of a carboxylate, a sulfate ester salt, and a sulfonate, 5 parts of an ethoxylated polyether, 3 parts of a polymerized siloxane, and 1 part of titanium dioxide, increase the speed to 1350 r / min and continue stirring for 25 min.

[0069] S3, the speed is reduced to 700r / min, and then a protective glue solution, 20 parts of pure acrylic latex, 1 part of a film-forming aid composed of propylene glycol and dodecyl alcohol ester, 5 parts of dimethyl silicone oil, and 1 part of urethane are added and stirred continuously to obtain a basic coating solution;

[0070] S4, under stirring conditions, add 15 parts of silicone acrylic latex, 3 parts of hexanediol butyl ether acetate, 3 parts of polymerized siloxane, 6 parts of new carbendazim, 1 part of sodium polyacrylate and a thickener consisting of polyacrylamide to 25 parts of deionized water, and stir evenly to obtain a continuous phase solution;

[0071] S5. Mix the continuous phase solution with the base coating solution, and stir at 600 r / min for 30 min until the mixture is uniform to obtain the coating.

[0072] The difference between Comparative Example 3 and Example 1 is that the ratio of each raw material component has been changed, which is not within the scope of the present application.

[0073] The coatings prepared in Examples 1 to 4 and Comparative Examples 1 to 3 were compared in terms of performance, and the results are shown in Table 1:

[0074]

[0075]

[0076] According to the above table, the coatings of Example 4 prepared by the raw materials, proportions and methods of the present invention have strong self-cleaning performance. After being scraped on the wall, the surface is flat, without peeling and bubbles, and it is effectively attached to the surface of the substrate. When placed in a natural environment, the appearance and performance are not significantly affected, and the surface and product performance retention are excellent. However, the coatings prepared by Comparative Examples 1 to Comparative Examples 3, due to the change of the raw materials, proportions and methods of the products, the obtained product performance is not as good as the coating of the present invention, and there is a greater impact on the self-cleaning degree and appearance retention, and it cannot be effectively applied to industrial products.

[0077] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A weather-resistant self-cleaning coating, characterized in that: The self-cleaning coating comprises, by weight, 50-70 parts of deionized water, 20-28 parts of protective glue, 20-35 parts of hydroxyethyl cellulose, 18-25 parts of latex, 5-8 parts of preservatives, 3-7 parts of dispersants, 4-7 parts of wetting agents, 1-2 parts of defoamers, 3-5 parts of pigments and fillers, 3-5 parts of film-forming aids, and 2-4 parts of thickeners; The latex consists of silicone-acrylic latex and pure acrylic latex.

2. A weather-resistant self-cleaning coating according to claim 1, characterized in that: The protective glue is modified lithium magnesium silicate; the pigment filler is titanium dioxide.

3. A weather-resistant self-cleaning coating according to claim 2, characterized in that: The preservative is at least one of carbamate and new carbendazim; the dispersant is at least one of sodium oleate, carboxylate, sulfate ester salt, sulfonate, quaternary ammonium salt and pyridinium salt; the wetting agent is ethoxylated polyether; the defoaming agent is one or more of polymerized siloxane and dimethyl silicone oil; the film-forming aid is composed of at least one of propylene glycol, dodecyl alcohol ester and hexanediol butyl ether acetate; the thickener is at least one of sodium polyacrylate, organic bentonite and polyacrylamide.

4. A weather-resistant self-cleaning coating according to any one of claims 1 to 3, further comprising a method for preparing the weather-resistant self-cleaning coating, characterized in that: The following steps are included: S1. Add protective glue into deionized water and disperse to obtain protective glue solution; S2. Add hydroxyethyl cellulose to deionized water under stirring conditions, and then add dispersant, wetting agent, defoamer, pigment and filler after stirring; S3, reduce the speed, add protective glue solution, latex, film-forming aid, defoamer, preservative and continue stirring to obtain a basic coating solution; S4, under stirring conditions, adding latex, film-forming aid, defoamer, preservative, and thickener to deionized water, and stirring evenly to obtain a continuous phase solution; S5. Mix the continuous phase solution and the base coating solution and stir them evenly to obtain a weather-resistant self-cleaning coating.

5. A weather-resistant self-cleaning coating according to claim 4, characterized in that: In the step S1, the stirring speed is 800-1200 r / min, and the stirring time is 20-30 min.

6. The method for preparing a weather-resistant self-cleaning coating according to claim 4, characterized in that: In step S2, when hydroxyethyl cellulose is added, the stirring rate is 200-300 r / min, and the stirring time is 2-3 min; after adding the dispersant, wetting agent, defoamer, color filler, and multifunctional additive, the stirring rate is 1200-1500 r / min, and the stirring time is 20-30 min.

7. The method for preparing a weather-resistant self-cleaning coating according to claim 4, characterized in that: In the step S3, the stirring rate after the rate reduction is 600-800 r / min, and the stirring time after adding the protective glue solution, latex, film-forming aid, propylene glycol, defoaming agent and preservative is 5-10 min.

8. The method for preparing a weather-resistant self-cleaning coating according to claim 4, characterized in that: In step S4, the stirring rate is 600-800 r / min, and the stirring time is 10-20 min.

9. A weather-resistant self-cleaning paint according to any one of claims 1 to 3, suitable for painting and scraping on the exterior walls of buildings.

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