Preparation process of self-cleaning FEVE varnish

Abstract

The application belongs to the technical field of industrial coatings, and discloses a preparation process of self-cleaning FEVE varnish. The preparation process of the self-cleaning FEVE varnish comprises the following steps: (1) preparing a protective latex emulsion; (2) adding a wetting agent and a defoaming agent; (3) adding a composite sol; (4) adding FEVE resin, then adding a curing agent, and preparing the self-cleaning FEVE varnish after aging. The self-cleaning FEVE varnish prepared by the preparation process of the self-cleaning FEVE varnish has excellent adhesion, high weather resistance and good self-cleaning performance, and can be widely applied to building outer walls, transportation equipment, ocean facilities, urban public facilities and the like.

Description

Technical Field

[0001] This application relates to the field of industrial coatings technology, and in particular to a preparation process for a self-cleaning FEVE varnish. Background Technology

[0002] Compared to ordinary coatings, fluorocarbon coatings possess unparalleled superior properties, including weather resistance, durability, acid and alkali resistance, chemical corrosion resistance, heat resistance, cold resistance, self-cleaning properties, non-stick properties, self-lubrication, and radiation resistance. Their service life is 3-5 times that of ordinary coatings. Fluorocarbon paints, in particular, are widely used in various construction projects, including building and bridge construction, due to their excellent heat resistance, weather resistance, and corrosion resistance.

[0003] Solvent-soluble coatings can form films at lower or even room temperatures, expanding their application range. They are produced by copolymerizing various fluorinated monomers with ethylene monomers containing side groups or other polar ethylene monomers, reducing crystallinity and increasing solvent solubility. Organic solvent-soluble thermoplastic fluoropolymer coatings with molecular weights of 2000-5000 can be produced by solution polymerization or suspension polymerization of tetrafluoroethylene or trifluorochloroethylene monomers with other polar ethylene monomers under controlled conditions. However, many current fluorocarbon paints suffer from poor stain resistance, solvent resistance, water and alkali resistance, aging resistance, and mildew and algae resistance. They also exhibit high surface tension, release volatile gases, and are not safe or environmentally friendly enough. These problems, especially the difficulty in removing stains after graffiti, remain unresolved. Summary of the Invention

[0004] To address at least one of the aforementioned technical problems, a fluorocarbon coating with good weather resistance, water resistance, strong chemical corrosion resistance, and good self-cleaning properties is developed. This application provides a preparation process for a self-cleaning FEVE varnish.

[0005] In a first aspect, this application provides a preparation process for a self-cleaning FEVE varnish, comprising the following steps:

[0006] S1. Add hydrogenated styrene-butadiene latex, water, and propylene glycol to the mixer, adjust the speed to 800-1000 rpm, and stir for 20-30 minutes. Add hydrogenated nitrile rubber powder and stir for 30-50 minutes. Add acrylate emulsion and adjust the speed to 1000-1200 rpm and stir for 5-10 minutes to obtain a protective latex for later use.

[0007] S2. Add wetting agent and defoamer to the protective latex obtained in step S1, and stir at 400-800 rpm for 10-20 minutes.

[0008] S3. Add the composite sol to the protective colloid emulsion treated in step S2, and ultrasonically disperse it at 60-80℃ for 10-15 minutes, then stir continuously at 800-1200rpm for 2-3 hours.

[0009] S4. Add FEVE resin to the protective colloid emulsion treated in step S3, stir at 50-60℃ for 3-5 hours, then add curing agent, stir at 50-60℃ for 0.5-1 hours, and cure for 2-3 hours to obtain self-cleaning FEVE varnish.

[0010] By adopting the above technical solution, the self-cleaning FEVE varnish provided in this application utilizes the fact that the surface energy of fluorocarbon emulsion is higher than that of acrylic emulsion (i.e., protective colloid emulsion), making it easier to generate self-delamination during the coating film formation process. The fluorocarbon emulsion floats to the surface of the coating, giving the fluorinated compound excellent weather resistance, stain resistance, and chemical resistance.

[0011] Optionally, the self-cleaning FEVE varnish comprises the following raw materials in parts by weight: 30-60 parts of protective colloid emulsion, 2-3 parts of wetting agent, 1-2 parts of defoamer, 15-28 parts of composite sol, 20-45 parts of FEVE resin, and 5-10 parts of curing agent.

[0012] Preferably, the self-cleaning FEVE varnish comprises the following raw materials in parts by weight: 46 parts of protective colloid emulsion, 2.5 parts of wetting agent, 1.5 parts of defoamer, 30 parts of FEVE resin, and 8 parts of curing agent.

[0013] Optionally, the defoamer is selected from one or more of polyoxyethylene polyoxypropylene pentaerythritol ether, polyoxyethylene polyoxypropylene alcohol ether, polyoxypropylene glycerol ether, and polydimethylsiloxane.

[0014] Optionally, in step S1, the preparation method of the hydrogenated styrene-butadiene latex is as follows: add styrene-butadiene latex into a container, heat while stirring, add hydrazine hydrate when the temperature rises to 55-65℃, add boric acid, add hydrogen peroxide dropwise while stirring, and react for 1-2 hours after the addition is completed to obtain hydrogenated styrene-butadiene latex.

[0015] Optionally, in the preparation of the protective latex in step S1, the weight ratio of hydrogenated styrene-butadiene latex, water, propylene glycol, hydrogenated nitrile rubber powder, and acrylate latex is 5-13:12-28:1.5:3-6:12-20.

[0016] By adopting the above technical solution, adding hydrogenated styrene-butadiene rubber latex to the protective latex can significantly improve the smoothness of the FEVE varnish film, reduce the uneven structure and pores on the surface of the FEVE varnish film, and improve the stain resistance of the FEVE varnish. In the blend system of hydrogenated styrene-butadiene rubber latex and hydrogenated nitrile rubber powder, the glass transition temperatures of the two are very close, and the compatibility is good. Adding hydrogenated nitrile rubber powder to hydrogenated styrene-butadiene rubber latex can significantly improve the adhesion and mechanical properties of hydrogenated styrene-butadiene rubber latex; combining the two and adding them to the acrylic emulsion for blending can significantly improve the weather resistance of the protective latex.

[0017] Optionally, in step S3, the preparation method of the composite sol includes: adding tetraethyl orthosilicate and water to a reaction vessel, adjusting the pH to 2-3, stirring at 35°C until the liquid is clear and transparent, adding a suspension of inorganic filler with a mass fraction of 10 wt%, ultrasonically dispersing at 50-60°C for 10-15 minutes, stirring at 50-60°C for 3-5 hours, cooling, and standing for 2 hours to obtain the composite sol; the weight ratio of tetraethyl orthosilicate, water, and the suspension of inorganic filler is 5-8.5:10-25:36-55.

[0018] Optionally, the inorganic filler is selected from one of nano-titanium dioxide, nano-silica, nano-calcium carbonate, and nano-hydrotalcite.

[0019] Preferably, the inorganic filler is selected from nano-titanium dioxide.

[0020] Optionally, in step S1, the particle size of the hydrogenated nitrile rubber powder is 1-30 μm; and in the preparation of the composite sol, the particle size of the inorganic filler is 50-600 nm.

[0021] By adopting the above technical solution, this application utilizes organosilicon sol to coat inorganic fillers and blends the composite sol with a protective colloid emulsion. When exposed to ultraviolet light, the small amount of active free radicals generated can break the chemical bonds of polymer molecules in the paint film, leading to film aging. Using organosilicon sol to coat inorganic fillers can slow down this process and prevent film aging; it also improves the stability of the inorganic fillers, thereby enhancing the film's UV resistance. Furthermore, by controlling the particle size difference between the inorganic fillers in the composite sol and the hydrogenated nitrile rubber powder in the acrylate emulsion within a certain range, the water resistance, mechanical properties, and adhesion of the paint film are balanced. This prevents problems such as uneven dispersion due to excessive particle size difference between the inorganic fillers and the hydrogenated nitrile rubber powder, or insufficient improvement in water resistance and mechanical properties due to insufficient particle size difference.

[0022] Optionally, the FEVE resin is a trifluorofluorocarbon resin with a solid fluorine content of 20-28%.

[0023] By adopting the above technical solution, the coating prepared by the present invention using FEVE fluorocarbon resin, protective colloid emulsion and titanium dioxide coated with organosilicon sol as raw materials forms a highly interpenetrating, three-dimensional network structure through cross-linking between the various substances, which has excellent adhesion, high density and high weather resistance.

[0024] In summary, the present invention has at least one of the following beneficial technical effects:

[0025] 1. The FEVE varnish film prepared by this invention has extremely low surface energy, which greatly reduces the adhesion of pollutants. The FEVE varnish prepared by this invention using FEVE fluorocarbon resin, protective colloid emulsion and organosilicon sol-coated titanium dioxide as raw materials increases the crosslinking density of the FEVE varnish film and the cohesive energy of the FEVE varnish film also increases, thereby improving the film's resistance to acid, alkali and neutral salt ion erosion, while significantly reducing the VOC content in the FEVE varnish. On the one hand, it meets environmental protection requirements, and on the other hand, it gives the FEVE varnish film excellent adhesion, high density, high weather resistance and good self-cleaning properties.

[0026] 2. The FEVE varnish prepared by this invention is a solvent-based product that can be easily applied to modern urban public facilities, including building exteriors, transportation equipment, marine facilities, and urban utilities. It can be used on metal surfaces such as copper, aluminum, stainless steel, and iron, as well as glass and ceramic surfaces, providing anti-graffiti and anti-sticking effects, and resisting acid rain, salt spray, and ultraviolet radiation. It also possesses self-cleaning properties and is a paint with excellent overall performance. Detailed Implementation

[0027] The present application will be further described in detail below with reference to the embodiments.

[0028] This application designs a preparation process for a self-cleaning FEVE varnish, including the following steps:

[0029] S1. Add hydrogenated styrene-butadiene latex, water, and propylene glycol to the mixer, adjust the speed to 800-1000 rpm, and stir for 20-30 minutes. Add hydrogenated nitrile rubber powder and stir for 30-50 minutes. Add acrylate emulsion and adjust the speed to 1000-1200 rpm and stir for 5-10 minutes to obtain a protective latex for later use.

[0030] S2. Add wetting agent and defoamer to the protective latex obtained in step S1, and stir at 400-800 rpm for 10-20 minutes.

[0031] S3. Add the composite sol to the protective colloid emulsion treated in step S2, and ultrasonically disperse it at 60-80℃ for 10-15 minutes, then stir continuously at 800-1200rpm for 2-3 hours.

[0032] S4. Add FEVE resin to the protective colloid emulsion treated in step S3, stir at 50-60℃ for 3-5 hours, then add curing agent, stir at 50-60℃ for 0.5-1 hours, and cure for 2-3 hours to obtain self-cleaning FEVE varnish.

[0033] The technical problem addressed by this application is that many current fluorocarbon paints suffer from poor stain resistance, solvent resistance, water and alkali resistance, aging resistance, and mildew and algae resistance. They also exhibit high surface tension, release volatile gases, and are not safe or environmentally friendly enough. These problems are either unresolved or incompletely resolved, particularly the difficulty in removing stains after graffiti. This application addresses this issue by compounding FEVE varnish with FEVE fluorocarbon resin, protective colloid emulsion, and titanium dioxide coated with organosilicon sol. This process increases the crosslinking density and cohesive energy of the FEVE varnish film, thereby improving its resistance to acid, alkali, and neutral salt ion erosion. Simultaneously, it significantly reduces the VOC content in the FEVE varnish, meeting environmental protection requirements while simultaneously giving the FEVE varnish film excellent adhesion, high density, high weather resistance, and good self-cleaning properties.

[0034] The raw materials used in the embodiments of this application are all commercially available, and their sources are as follows:

[0035] Styrene-butadiene latex, total solids content 23%, China Petroleum Jilin Petrochemical Company;

[0036] Hydrazine hydrate, 80 wt%, Tianjin Yingda Rare and Precious Chemical Reagent Factory;

[0037] Boric acid, Beijing Yili Fine Chemicals Co., Ltd.;

[0038] Hydrogenated nitrile butadiene rubber powder, Jiangsu Hengda Packaging Co., Ltd.;

[0039] Dynol 604, Evonik Industries;

[0040] Polydimethylsiloxane, Shanghai Yuanye Biotechnology Co., Ltd.;

[0041] Tetraethyl orthosilicate, Hubei Hengjingrui Chemical Co., Ltd.;

[0042] Titanium dioxide, Guangdong Wengjiang Chemical Reagent Co., Ltd.;

[0043] FEVE resin, Shanghai Dongfu Chemical Technology Co., Ltd.;

[0044] Acrylic ester emulsion, HD-8253, Shandong Jiaying Chemical Technology Co., Ltd.;

[0045] Toluene diisocyanate, Jinan Yingniang Chemical Co., Ltd.

[0046] Example 1

[0047] The preparation process of the self-cleaning FEVE varnish in Example 1 includes the following steps:

[0048] S1. Add hydrogenated styrene-butadiene latex, water, and propylene glycol to a mixer, adjust the speed to 900 rpm, and stir for 25 min. Add hydrogenated nitrile rubber powder and stir for 40 min. Add acrylate emulsion and adjust the speed to 1100 rpm and stir for 8 min to obtain a protective latex for later use. The weight ratio of hydrogenated styrene-butadiene latex, water, propylene glycol, hydrogenated nitrile rubber powder, and acrylate emulsion is 8:18:1.5:5:16. The preparation method of hydrogenated styrene-butadiene latex is as follows: add styrene-butadiene latex to a container, heat while stirring, add hydrazine hydrate and boric acid when the temperature reaches 60℃, and add 30wt% hydrogen peroxide dropwise while stirring. After the addition is complete, react for 1.5 h to obtain hydrogenated styrene-butadiene latex. The weight ratio of styrene-butadiene latex, hydrazine hydrate, boric acid, and hydrogen peroxide is 10:2:0.5:2. The average particle size of hydrogenated nitrile rubber powder is 20 μm.

[0049] S2. Add wetting agent and defoamer to the protective colloid latex obtained in step S1, and stir at 600 rpm for 18 min; wherein, the wetting agent is an acetylenic diol wetting agent, model Dynol 604; and the defoamer is polydimethylsiloxane.

[0050] S3. Add the composite sol to the protective colloid emulsion treated in step S2, and ultrasonically disperse it at 75°C with a power of 10kHz for 15 minutes, followed by continuous stirring at 1000rpm for 2.5 hours. The preparation process of the composite sol is as follows: add tetraethyl orthosilicate and water to the reaction vessel, adjust the pH to 3, stir at 35°C until the liquid is clear and transparent, add a titanium dioxide suspension with a mass fraction of 10wt%, ultrasonically disperse it at 55°C for 13 minutes, stir at 55°C for 3.5 hours after ultrasonication, cool, and let stand for 2 hours to obtain the composite sol. The weight ratio of tetraethyl orthosilicate, water and titanium dioxide suspension is 7:20:40, and the average particle size of titanium dioxide in the titanium dioxide suspension is 200nm.

[0051] S4. Add FEVE resin to the protective colloid emulsion treated in step S3, stir at 55°C for 3.5 hours, then add curing agent, stir at 55°C for 0.8 hours, and cure for 2 hours to obtain self-cleaning FEVE varnish; the FEVE resin is a trifluorofluorocarbon resin (manufacturer: Shanghai Dongfu Chemical Technology Co., Ltd., model: ZHM-2), with a solid fluorine content of 26%; the curing agent is toluene diisocyanate.

[0052] The raw materials for the self-cleaning FEVE varnish prepared in Example 1, by weight, include: 40 parts of protective colloid emulsion, 2.5 parts of wetting agent, 1.6 parts of defoamer, 22 parts of composite sol, 30 parts of FEVE resin, and 6 parts of curing agent.

[0053] Example 2

[0054] Example 2 is based on Example 1, except that the raw material ratios of the self-cleaning FEVE varnish, the protective colloid emulsion, and the composite sol are changed in Example 2, as detailed below:

[0055] The preparation process of the self-cleaning FEVE varnish in Example 2 includes the following steps:

[0056] S1. Add hydrogenated styrene-butadiene latex, water, and propylene glycol to a mixer, adjust the speed to 900 rpm, and stir for 25 min. Add hydrogenated nitrile rubber powder and stir for 40 min. Add acrylate emulsion and adjust the speed to 1100 rpm and stir for 8 min to obtain a protective latex for later use. The weight ratio of hydrogenated styrene-butadiene latex, water, propylene glycol, hydrogenated nitrile rubber powder, and acrylate emulsion is 5:28:1.5:3:12. The preparation method of hydrogenated styrene-butadiene latex is as follows: add styrene-butadiene latex to a container, heat while stirring, add hydrazine hydrate and boric acid when the temperature reaches 60℃, and add 30wt% hydrogen peroxide dropwise while stirring. After the addition is complete, react for 1.5 h to obtain hydrogenated styrene-butadiene latex. The weight ratio of styrene-butadiene latex, hydrazine hydrate, boric acid, and hydrogen peroxide is 10:2:0.5:2. The average particle size of hydrogenated nitrile rubber powder is 20 μm.

[0057] S2. Add wetting agent and defoamer to the protective colloid latex obtained in step S1, and stir at 600 rpm for 18 min; wherein, the wetting agent is an acetylenic diol wetting agent, model Dynol 604; and the defoamer is polydimethylsiloxane.

[0058] S3. Add the composite sol to the protective colloid emulsion treated in step S2, and ultrasonically disperse it at 75°C with a power of 10kHz for 15 minutes, followed by continuous stirring at 1000rpm for 2.5 hours. The preparation process of the composite sol is as follows: add tetraethyl orthosilicate and water to the reaction vessel, adjust the pH to 3, stir at 35°C until the liquid is clear and transparent, add a titanium dioxide suspension with a mass fraction of 10wt%, ultrasonically disperse it at 55°C for 13 minutes, stir at 55°C for 3.5 hours after ultrasonication, cool, and let stand for 2 hours to obtain the composite sol. The weight ratio of tetraethyl orthosilicate, water and titanium dioxide suspension is 5:10:36, and the average particle size of titanium dioxide in the titanium dioxide suspension is 200nm.

[0059] S4. Add FEVE resin to the protective colloid emulsion treated in step S3, stir at 55°C for 3.5 hours, then add curing agent, stir at 55°C for 0.8 hours, and cure for 2 hours to obtain self-cleaning FEVE varnish; the FEVE resin is a trifluorofluorocarbon resin with a solid fluorine content of 26%; the curing agent is toluene diisocyanate.

[0060] The raw materials for the self-cleaning FEVE varnish prepared in Example 2, by weight, include: 30 parts of protective colloid emulsion, 2 parts of wetting agent, 1 part of defoamer, 15 parts of composite sol, 20 parts of FEVE resin, and 5 parts of curing agent.

[0061] Example 3

[0062] Example 3 is based on Example 1, except that the raw material ratios of the self-cleaning FEVE varnish, the protective colloid emulsion, and the composite sol are changed in Example 3, as detailed below:

[0063] The preparation process of the self-cleaning FEVE varnish in Example 3 includes the following steps:

[0064] S1. Add hydrogenated styrene-butadiene latex, water, and propylene glycol to a mixer, adjust the speed to 900 rpm, and stir for 25 min. Add hydrogenated nitrile butadiene rubber powder and stir for 40 min. Add acrylate emulsion and adjust the speed to 1100 rpm and stir for 8 min to obtain a protective latex for later use. The weight ratio of hydrogenated styrene-butadiene latex, water, propylene glycol, hydrogenated nitrile butadiene rubber powder, and acrylate emulsion is 13:12:1.5:6:20. The preparation method of hydrogenated styrene-butadiene latex is as follows: add styrene-butadiene latex to a container, heat while stirring, add hydrazine hydrate and boric acid when the temperature reaches 60℃, and add 30wt% hydrogen peroxide dropwise while stirring. After the addition is complete, react for 1.5 h to obtain hydrogenated styrene-butadiene latex. The weight ratio of styrene-butadiene latex, hydrazine hydrate, boric acid, and hydrogen peroxide is 10:2:0.5:2. The average particle size of hydrogenated nitrile butadiene rubber powder is 20 μm.

[0065] S2. Add wetting agent and defoamer to the protective colloid latex obtained in step S1, and stir at 600 rpm for 18 min; wherein, the wetting agent is an acetylenic diol wetting agent, model Dynol 604; and the defoamer is polydimethylsiloxane.

[0066] S3. Add the composite sol to the protective colloid emulsion treated in step S2, and ultrasonically disperse it at 75°C with a power of 10kHz for 15 minutes, followed by continuous stirring at 1000rpm for 2.5 hours. The preparation process of the composite sol is as follows: add tetraethyl orthosilicate and water to the reaction vessel, adjust the pH to 3, stir at 35°C until the liquid is clear and transparent, add a titanium dioxide suspension with a mass fraction of 10wt%, ultrasonically disperse it at 55°C for 13 minutes, stir at 55°C for 3.5 hours after ultrasonication, cool, and let stand for 2 hours to obtain the composite sol. The weight ratio of tetraethyl orthosilicate, water and titanium dioxide suspension is 7:20:40, and the average particle size of titanium dioxide in the titanium dioxide suspension is 200nm.

[0067] S4. Add FEVE resin to the protective colloid emulsion treated in step S3, stir at 55°C for 3.5 hours, then add curing agent, stir at 55°C for 0.8 hours, and cure for 2 hours to obtain self-cleaning FEVE varnish; the FEVE resin is a trifluorofluorocarbon resin with a solid fluorine content of 26%; the curing agent is toluene diisocyanate.

[0068] The raw materials for the self-cleaning FEVE varnish prepared in Example 3, by weight, include: 60 parts of protective colloid emulsion, 3 parts of wetting agent, 2 parts of defoamer, 28 parts of composite sol, 45 parts of FEVE resin, and 10 parts of curing agent.

[0069] Examples 4-5

[0070] Example 4 is based on Example 1, except that the average particle size of the hydrogenated nitrile rubber powder used in Example 4 is 30 μm, and the average particle size of the titanium dioxide in the titanium dioxide suspension used is 50 nm.

[0071] Example 5 is based on Example 1, except that: in Example 5, the average particle size of the hydrogenated nitrile rubber powder used is 1 μm, and the average particle size of the titanium dioxide in the titanium dioxide suspension used is 600 nm.

[0072] Example 6

[0073] Example 6 is based on Example 1, except that the titanium dioxide suspension used in the composite sol preparation process in step S3 is replaced with a silica suspension.

[0074] Examples 7-9

[0075] Example 7 is based on Example 1, except that the FEVE resin used in Example 7 is a tetrafluorofluorocarbon resin (manufacturer: Shanghai Dongfu Chemical Technology Co., Ltd., model: HLR-670) with a solid fluorine content of 26%.

[0076] Example 8 is based on Example 1, except that the FEVE resin used in Example 8 is a trifluoro fluorocarbon resin (manufacturer: Shanghai Dongfu Chemical Technology Co., Ltd., model: ZHM-3) with a solid fluorine content of 20%.

[0077] Example 9 is based on Example 1, except that the FEVE resin used in Example 9 is a trifluoro fluorocarbon resin (manufacturer: Shanghai Dongfu Chemical Technology Co., Ltd., model: ZHM-5) with a solid fluorine content of 28%.

[0078] Comparative Examples 1-3

[0079] Comparative Example 1 is based on Example 1, except that the hydrogenated styrene-butadiene latex used in step S1 is replaced with styrene-butadiene latex.

[0080] Comparative Example 2 is based on Example 1, except that: in Comparative Example 2, titanium dioxide suspension is used instead of composite sol, and step S3 is changed to:

[0081] A 10wt% titanium dioxide suspension was added to the protective colloid latex treated in step S2, and ultrasonically dispersed at 75°C and 10kHz for 15 minutes, followed by continuous stirring at 1000rpm for 2.5 hours; wherein the average particle size of titanium dioxide was 200nm.

[0082] Comparative Example 3 is based on Example 1, except that: in Comparative Example 3, FEVE resin is replaced with fluoroacrylate (composed of hexafluorobutyl acrylate and acrylate polymer monomers, with a solid fluorine content of 26%).

[0083] Performance testing

[0084] 1. The stain resistance, scrub resistance, water resistance and alkali resistance of the self-cleaning FEVE varnishes prepared in Examples 1-9 and Comparative Examples 1-3 were tested according to standard JC / T1040-2007. The test results are shown in Table 1.

[0085] 2. The adhesion, salt spray resistance and artificial accelerated aging resistance of the self-cleaning FEVE varnishes prepared in Examples 1-9 and Comparative Examples 1-3 were tested according to standard HG / T4341-2012. The test results are shown in Table 2.

[0086] Table 1

[0087]

[0088] Table 2

[0089]

[0090]

[0091] Analysis of the data in Tables 1 and 2, and comparison of the performance of Examples 1-9 and Comparative Examples 1-3, reveals that the FEVE varnish prepared in Example 1 exhibits the best performance across all aspects, demonstrating excellent adhesion, high weather resistance, and good self-cleaning properties. In summary, the self-cleaning FEVE varnish prepared using the process described in this application is conveniently applicable to modern urban public facilities, including building exteriors, transportation equipment, marine facilities, and urban public utilities. It can be used on surfaces of metals such as copper, aluminum, stainless steel, and steel, as well as glass and ceramics, providing anti-graffiti and anti-sticking effects, and resisting acid rain, salt spray, and ultraviolet radiation. It possesses "self-cleaning" properties and is a paint with excellent overall performance.

[0092] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A preparation process for a self-cleaning FEVE varnish, characterized in that, Includes the following steps: S1. Mix hydrogenated styrene-butadiene latex, water and propylene glycol, stir, add hydrogenated nitrile rubber powder, stir, add acrylate emulsion, stir, and prepare a protective latex for later use. S2. Add wetting agent and defoamer to the protective latex obtained in step S1, and stir. S3. Add the composite sol to the protective colloid emulsion treated in step S2, disperse it ultrasonically at 60-80℃, and then stir for 2-3 hours. S4. Add FEVE resin to the protective colloid emulsion treated in step S3, stir, then add curing agent, stir, and cure to obtain self-cleaning FEVE varnish. In step S1, the preparation method of the hydrogenated styrene-butadiene latex is as follows: add styrene-butadiene latex into a container, stir and heat, add hydrazine hydrate and boric acid when the temperature reaches 55-65℃, add hydrogen peroxide dropwise while stirring, and react for 1-2 hours after the addition is completed to obtain hydrogenated styrene-butadiene latex. In step S3, the preparation method of the composite sol includes: adding tetraethyl orthosilicate and water to a reaction vessel, adjusting the pH to 2-3, stirring at 35°C until the liquid is clear and transparent, adding a suspension of inorganic filler with a mass fraction of 10 wt%, ultrasonically dispersing at 50-60°C for 10-15 minutes, stirring at 50-60°C for 3-5 hours, cooling, and standing for 2 hours to obtain the composite sol; the weight ratio of tetraethyl orthosilicate, water, and the suspension of inorganic filler is 5-8.5:10-25:36-55.

2. The preparation process of the self-cleaning FEVE varnish according to claim 1, characterized in that, By weight, the components of the self-cleaning FEVE varnish are: 30-60 parts of protective colloid emulsion, 2-3 parts of wetting agent, 1-2 parts of defoamer, 15-28 parts of composite sol, 20-45 parts of FEVE resin, and 5-10 parts of curing agent.

3. The preparation process of the self-cleaning FEVE varnish according to claim 1, characterized in that, In the preparation of the protective latex in step S1, the weight ratio of hydrogenated styrene-butadiene latex, water, propylene glycol, hydrogenated nitrile rubber powder, and acrylate latex is 5-13:12-28:1.5:3-6:12-20.

4. The preparation process of the self-cleaning FEVE varnish according to claim 1, characterized in that, The inorganic filler is selected from one of nano titanium dioxide, nano silicon dioxide, nano calcium carbonate, and nano hydrotalcite.

5. The preparation process of the self-cleaning FEVE varnish according to claim 1, characterized in that, In step S1, the particle size of the hydrogenated nitrile rubber powder is 1-30 μm; in the preparation of the composite sol, the particle size of the inorganic filler is 50-600 nm.

6. The preparation process of the self-cleaning FEVE varnish according to claim 1, characterized in that, In step S4, the FEVE resin is a trifluorofluorocarbon resin with a solid fluorine content of 20-28%.

7. The preparation process of the self-cleaning FEVE varnish according to claim 1, characterized in that, The curing agent in step S4 is one or more of toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,6'-hexane diisocyanate, and polymethylene polyphenyl polyisocyanate.

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