Super-hydrophilic self-cleaning silicon resin coating as well as preparation method and application thereof

Abstract

The invention relates to a super-hydrophilic self-cleaning silicon resin coating as well as a preparation method and application thereof, and belongs to the technical field of self-cleaning coatings. The coating comprises the following components in percentage by mass: 10-20% of an organic silicon resin diluent, 3-8% of a photocatalytic material, 15-25% of a nano SiO2 film-forming material, 0.5-1% of a wetting agent, 0.1-0.2% of a film-forming aid and 50-65% of a cosolvent, wherein the organic silicon resin diluent is a uniform dispersion liquid formed by crosslinking organic silicon resin with a silane coupling agent; the photocatalytic material is a nano metal oxide dispersion liquid; the nano SiO2 film forming material is acidic hydrolyzed sol containing silicate ester and nano silicon dioxide dispersion liquid. The super-hydrophilic self-cleaning silicon resin coating provided by the invention has the advantages of good adhesiveness, good anti-reflection performance, good hydrophilicity and high hardness, and can be applied to coatings on the surface of a photovoltaic module or the outer wall surface of a building and the like.

Description

Technical Field

[0001] The invention relates to the technical field of self-cleaning coatings, and in particular to a super-hydrophilic self-cleaning silicone resin coating and a preparation method and application thereof. Background Art

[0002] With the development of science and technology and the improvement of living standards, the process of urbanization is accelerating, and the cleaning of the outer surfaces of urban buildings and infrastructure has gradually received attention. A large amount of dust is easily accumulated on the surfaces of infrastructure such as photovoltaic modules, exterior wall glass, tiles, curtain walls, etc., especially the dust accumulation on the surface of solar cells will affect the light transmission performance of photovoltaic glass, leading to light scattering and heat accumulation, seriously affecting the efficiency of photovoltaic power generation and the service life of photovoltaic cells. Therefore, there is an urgent need for self-cleaning coatings that can be applied to photovoltaic modules and other infrastructure to reduce the number of manual cleaning and maintenance, and ensure the long-term stable and efficient operation of photovoltaic modules.

[0003] As a polysiloxane polymer with a highly cross-linked structure, silicone resin combines the characteristics of organic resin and inorganic materials and has unique physical and chemical properties. While being moisture-proof and high-temperature resistant, silicone resin can maintain high transparency, strong adhesion, high hardness and high density, and the resulting coating has good durability. Currently, the photocatalytic self-cleaning coatings on the market have poor mechanical properties such as adhesion and hardness to the substrate, while general silicone resin coatings do not have super-hydrophilic, self-cleaning, anti-fouling and dust-proof properties.

[0004] Therefore, a super-hydrophilic self-cleaning silicone resin coating with better performance, a preparation method and an application thereof are now provided. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention provides a super hydrophilic self-cleaning silicone resin coating and a preparation method and application thereof. By improving the raw material components and the preparation method, the coating has the characteristics of super hydrophilicity, self-cleaning, dust and anti-fouling, etc.

[0006] The invention provides a super-hydrophilic self-cleaning silicone resin coating, which comprises the following components by mass fraction: 10-20% of an organic silicone resin diluent, 3-8% of a photocatalytic material, 15-25% of a nano-SiO2 film-forming material, 0.5%-1% of a wetting agent, 0.1-0.2% of a film-forming aid, and 50%-65% of a co-solvent; wherein the organic silicone resin diluent is a uniform dispersion formed by cross-linking the organic silicone resin with a silane coupling agent; the photocatalytic material is a nano-metal oxide dispersion; and the nano-SiO2 film-forming material is an acidic hydrolysis sol containing a silicate and a nano-silicon dioxide dispersion.

[0007] Furthermore, the organic silicone resin diluent is obtained by dissolving silicone resin and silane coupling agent in an organic solvent; wherein the mass ratio of the organic solvent, silicone resin and silane coupling agent is 25-100:5-10:1.

[0008] Furthermore, the silicone resin includes any one of methyl silicone resin, phenyl silicone resin and methylphenyl silicone resin.

[0009] Furthermore, the silane coupling agent includes any one of γ-aminopropyltriethoxysilane, γ-glycidyloxypropyltrimethoxysilane or γ-methacryloxypropyltrimethoxysilane.

[0010] Furthermore, the organic solvent is any one or more of ethanol, acetone, n-butanol, isobutanol, propylene glycol methyl ether, ethylene glycol butyl ether, n-propanol and methanol.

[0011] Furthermore, the wetting agent is one or more of sodium olefin sulfonate, sodium dodecyl sulfate, sodium octadecylbenzene sulfonate, and sodium dodecyl sulfonate.

[0012] Furthermore, the photocatalytic material is an aqueous dispersion of any one or more of nano titanium dioxide, nano zinc oxide, nano tin oxide, nano zirconium oxide, nano aluminum oxide, and nano cerium oxide, with a concentration of 8-12 g / L.

[0013] Furthermore, the co-solvent refers to a solvent that can dissolve other components, for example, it can be a solvent obtained by mixing ethanol, acetone, and propylene glycol methyl ether in a mass ratio of 4:3:3.

[0014] Furthermore, the nano-SiO2 film-forming material is prepared by the following method: adding silicate, nano-silicon dioxide aqueous dispersion, and ethanol in sequence, with a mass ratio of 5-10:2-6:10-25, stirring at a temperature of 25°C-40°C to make the mixture uniform, and then slowly adding concentrated hydrochloric acid, wherein the mass ratio of concentrated hydrochloric acid to nano-silicon dioxide aqueous dispersion is 1:15-30, and continuing stirring for 3 hours to obtain the nano-SiO2 film-forming material; the silicate is any one or more of methyl orthosilicate, ethyl orthosilicate, propyl orthosilicate, and butyl orthosilicate.

[0015] The present invention also provides a method for preparing the above-mentioned super-hydrophilic self-cleaning silicone resin coating, comprising: adding a photocatalytic material and a nano-SiO2 film-forming material to a solvent and mixing and stirring at room temperature to obtain a mixed material; mixing the mixed material with a silicone resin diluent, adding a wetting agent and a film-forming aid, and magnetically stirring to evenly mix into a white transparent solution to obtain a super-hydrophilic self-cleaning silicone resin coating.

[0016] In the present invention, the silicone resin diluent is obtained by dissolving silicone resin and silane coupling agent in an organic solvent, wherein the mass ratio of the organic solvent, silicone resin and silane coupling agent is 25-100:5-10:1.

[0017] In the present invention, the role of the silicone resin is to improve the bonding force between the self-cleaning coating and the substrate, and also to improve the light transmittance, reduce light reflection on the coating surface, and at the same time improve the mechanical properties and aging resistance of the coating, so that the coating can maintain hydrophilic properties stably for a long time.

[0018] The composite coating can be used as a coating on the surface of solar photovoltaic panels due to its excellent super-hydrophilic properties and light transmittance. It can effectively prevent surface pollution of photovoltaic panels and improve the utilization rate of sunlight, thereby improving the power generation capacity of photovoltaic panels and the amount of power generated. At the same time, the coating can also be used on surfaces such as wood, paint, and metal plates. The dense coating formed by it can effectively prevent the aging of the substrate. In addition, the material can be coated on the outer surface of glass curtain walls and building walls, which can not only improve the surface hardness, but also effectively reduce the adhesion and accumulation of surface pollutants and achieve surface self-cleaning.

[0019] Based on this, the present invention also provides an application of a super hydrophilic self-cleaning silicone resin coating. The above-mentioned super hydrophilic self-cleaning silicone resin coating is suitable for coating the hard surfaces of solar photovoltaic panel cover glass, building walls or large billboards to adsorb and decompose organic pollutants to achieve self-cleaning.

[0020] Compared with the prior art, the present invention has the following beneficial effects: The organic silicone resin used in the super hydrophilic self-cleaning silicone resin coating of the present invention is a commercially available organic silicone resin, which is an alcohol-soluble organic silicone resin synthesized by reacting methylchlorosilane, phenylchlorosilane and special silane monomers. When the silicone resin is used as a film-forming material, the film layer has good flexibility and is not easy to break, and can self-solidify after the solvent evaporates, and can well attach the photocatalytic material to the surface of glass or other substrates. The introduction of transparent organic silicone resin improves the comprehensive mechanical properties of the coating, allows the coating to firmly adhere to the surface of the coated substrate, and has high hardness and density.

[0021] The present invention adopts a surfactant as a wetting agent to enhance the surface wettability of the coating, so that the coating can achieve super-hydrophilicity. At the same time, the silane coupling agent can promote the cross-linking of the organic silicon resin and other components, thereby improving the uniformity of the coating film formation.

[0022] The coating provided by the present invention has good photocatalytic self-cleaning performance and hydrophilicity, and can be applied to the outer surface of glass curtain walls, solar photovoltaic panel cover glass, and can be coated on hard surfaces such as building walls and large billboards. When used as a coating for photovoltaic panel cover glass, it can improve light transmittance, thereby improving the photoelectric conversion efficiency of solar cells.

[0023] The super-hydrophilic self-cleaning silicone resin coating provided by the present invention has super-hydrophilicity and photocatalytic self-cleaning performance. After being coated on a substrate to form a coating, surface impurities such as dust can be easily taken away by water droplets or oxidized and decomposed under light conditions, and has good self-cleaning ability. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 Schematic diagram of the comparison of static water contact angles of the super-hydrophilic self-cleaning silicone resin coating (a) and blank glass (b) according to the present invention; Figure 2 Schematic diagram showing a comparison of static water contact angles of the super-hydrophilic self-cleaning silicone resin coating (a) of the present invention and a commercially available silicone resin self-cleaning coating (b); Figure 3 Schematic diagram showing the comparison of the static water contact angles of the super hydrophilic self-cleaning silicone resin coating (a) of the present invention and the comparative example 1 (b); Figure 4 A comparison chart of the light transmittance of the super-hydrophilic self-cleaning silicone resin coating of the present invention and blank glass; Figure 5 A comparison chart of the light transmittance of the super-hydrophilic self-cleaning silicone resin coating of the present invention and a commercially available silicone resin self-cleaning coating; Figure 6 This is a comparison chart of the light transmittance of the super hydrophilic self-cleaning silicone resin coating described in the present invention and comparative example 4. DETAILED DESCRIPTION

[0026] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings. The following content is only an example and explanation of the concept of the present invention. The technicians in the relevant technical field make various modifications or supplements to the specific implementation cases described or replace them with similar methods. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

[0027] Unless otherwise specified, the raw materials, equipment, etc. involved in the present invention are common commercially available products.

[0028] Example 1: Preparation of nano-SiO2 film-forming material: Add silicate (methyl orthosilicate: ethyl orthosilicate = 1:1), ethanol, and nano-silicon dioxide aqueous dispersion into a reaction container in sequence, mix evenly at room temperature, then slowly add concentrated hydrochloric acid to the above solution, stir at 300 rpm for 3 h to allow it to undergo a hydrolysis reaction to obtain nano-SiO2 film-forming material. The mass ratio of the raw materials is 1:5:1:0.05.

[0029] (2) Preparation of nano-metal oxide dispersion: Add nano-titanium dioxide and nano-zinc oxide into deionized water, stir evenly, and ultrasonically oscillate at 25°C-45°C for 30 min to obtain a uniformly dispersed nano-metal oxide dispersion, wherein the ratio of nano-titanium dioxide: nano-zinc oxide: deionized water is 0.5:0.5:100.

[0030] (3) Preparation of silicone resin diluent: Add silicone resin into ethanol to disperse, stir evenly, add silane coupling agent γ-aminopropyltriethoxysilane, and stir again for 30 min, wherein the mass ratio of ethanol: silicone resin: silane coupling agent is 25:5:1, to obtain silicone resin diluent, and the ratio of each component in the silicone resin is methyl silicone resin: phenyl silicone resin: methylphenyl silicone resin = 5:3:2.

[0031] (4) Preparation of co-solvent: ethanol, acetone and propylene glycol methyl ether were mixed in a mass ratio of 4:3:3 and stirred to obtain a co-solvent.

[0032] (5) Take 15 mL of the above-prepared nano-SiO2 film-forming material, 3 mL of nano-metal oxide dispersion, and 0.15 g of film-forming aid, add 60 mL of co-solvent, shake for 30 min until uniform, then add 20 mL of silicone resin diluent and 0.5 g of wetting agent, and stir for 30 min to obtain a super hydrophilic self-cleaning silicone resin coating.

[0033] (6) The prepared super hydrophilic self-cleaning silicone resin coating was sprayed on the glass surface using a spray gun. The obtained coating sample was cured at room temperature for 24 h to obtain a super hydrophilic self-cleaning silicone resin coating.

[0034] Meanwhile, a control group was prepared, using the same glass but without coating the prepared super-hydrophilic self-cleaning silicone resin coating.

[0035] The contact angle of water on the surface of glass sprayed with super hydrophilic self-cleaning silicone resin coating was measured by contact angle meter. Figure 1 (a), the water contact angle is 4.5°; the surface water contact angle of the blank glass of the control group is measured by a contact angle meter. Figure 1 (b), the water contact angle is 70°, proving that the coating is superhydrophilic.

[0036] The light transmittance of the super-hydrophilic self-cleaning silicone resin coating sprayed glass and the control group blank glass in the 400-1100 nm band was measured using a UV-visible spectrophotometer with an integrating sphere. Figure 3 Among them, the light transmittance of the super-hydrophilic self-cleaning silicone resin coated glass in the 400-1100 nm band was 90.4-97.3%, and the light transmittance of the blank glass in the control group in the 400-1100 nm band was 89.7-91%, proving that the coating has the effect of increasing transmittance and reducing reflection.

[0037] Example 2: (1) Prepare a super hydrophilic self-cleaning silicone resin coating in the same manner as in Example 1.

[0038] (2) A composite coating without silicone resin was prepared by the same method as in Example 1.

[0039] (3) The prepared super-hydrophilic self-cleaning silicone resin coating and the composite coating without silicone resin were sprayed on the glass surface using a spray gun. The obtained coating samples were cured at room temperature for 24 h to obtain a super-hydrophilic self-cleaning silicone resin coating.

[0040] The adhesion was determined by observing the shedding condition using the 100-grid method. Through the measurement, the adhesion of the coating formed on the glass by the super-hydrophilic self-cleaning silicone resin coating described in this embodiment was level 0, which was excellent, and no coating shedding occurred after the 100-grid method test; the adhesion of the coating formed on the glass by the composite coating without silicone resin described in this embodiment was level 1.

[0041] The hardness of the coating was measured using an electric pencil hardness tester. Through the measurement, the hardness of the coating formed on the glass by the super hydrophilic self-cleaning silicone resin coating described in this embodiment was 6H; the hardness of the coating formed on the glass by the composite coating without silicone resin described in this embodiment was 3H.

[0042] The above results prove that the organic silicone resin can improve the mechanical properties of the super-hydrophilic self-cleaning silicone resin coating prepared by the present invention.

[0043] Example 3: A super hydrophilic self-cleaning silicone resin coating was prepared in the same manner as in Example 1.

[0044] Prepare a control group: Purchase SJ-1130 silicone resin self-cleaning paint from Congyang Sanjin Pigment, and apply it on the glass surface in the same way as in Example 1 as a control group.

[0045] The water contact angle of the coating surface was measured by a contact angle meter, the light transmittance of the coating in the 400-1100 nm band was measured by a UV-visible spectrophotometer, the hardness of the coating was determined by an electric pencil hardness tester, and the coating adhesion was determined by observing the shedding condition using the hundred-grid method.

[0046] The surface water contact angle of super hydrophilic self-cleaning silicone coating is as follows Figure 2 (a), the water contact angle is 4.5°; the water contact angle of the commercially available silicone self-cleaning layer of the control group is as follows Figure 2 (b), water contact angle is 82°.

[0047] The light transmittance of the two coatings in this embodiment is as follows Figure 4 As shown, the light transmittance of the super hydrophilic self-cleaning silicone resin coated glass in the 400-1100 nm band is 90.4-97.3%, and the light transmittance of the commercially available silicone resin self-cleaning coated glass in the control group in the 400-1100 nm band is 90.3-93.4%.

[0048] In addition, the hardness of the super hydrophilic self-cleaning silicone resin coating described in this embodiment is 6H, and the adhesion is level 0; the hardness of the commercially available silicone resin self-cleaning coating in the control group described in this embodiment is 4H, and the adhesion is level 1.

[0049] By comparing the above results, compared with the commercially available silicone self-cleaning coating in the control group, the super hydrophilic self-cleaning silicone coating of this embodiment has super hydrophilicity, higher light transmittance, and better mechanical properties such as hardness and adhesion.

[0050] Example 4: (1) Preparation of nano-SiO2 film-forming material: Add silicate (methyl orthosilicate:propyl orthosilicate = 1:1), ethanol, and nano-silicon dioxide aqueous dispersion into a reaction container in sequence, mix them evenly at room temperature, then slowly add concentrated hydrochloric acid to the above solution, stir at 300 rpm for 3 h to allow it to undergo a hydrolysis reaction, and obtain nano-SiO2 film-forming material. The mass ratio of the raw materials is 1:5:1:0.05.

[0051] (2) Preparation of nano-metal oxide dispersion: Add nano-titanium dioxide and nano-tin oxide into deionized water, stir evenly, and ultrasonically oscillate at 25°C-45°C for 30 min to obtain a uniformly dispersed nano-metal oxide dispersion, wherein the ratio of nano-titanium dioxide: nano-tin oxide: deionized water is 0.4:0.4:100.

[0052] (3) Preparation of silicone resin diluent: Add silicone resin into ethanol to disperse, stir evenly, add silane coupling agent γ-glycidyloxypropyltrimethoxysilane, and stir again for 30 min, wherein the mass ratio of ethanol: silicone resin: silane coupling agent is 25:5:1, to obtain silicone resin diluent, and the ratio of each component in the silicone resin is methyl silicone resin: phenyl silicone resin: methylphenyl silicone resin = 3:5:2.

[0053] (4) Preparation of co-solvent: ethanol, n-butanol and ethylene glycol butyl ether were mixed in a mass ratio of 4:3:3 and stirred to obtain a co-solvent.

[0054] (5) Take 15 mL of the above-prepared nano-SiO2 film-forming material, 5 mL of nano-metal oxide dispersion, and 0.15 g of film-forming aid, add 65 mL of co-solvent, shake for 30 min until uniform, then add 15 mL of silicone resin diluent and 0.5 g of wetting agent, and stir for 30 min to obtain a super hydrophilic self-cleaning silicone resin coating.

[0055] (6) The prepared super hydrophilic self-cleaning silicone resin coating was sprayed on the glass surface using a spray gun. The obtained coating sample was cured at room temperature for 24 h to obtain a super hydrophilic self-cleaning silicone resin coating.

[0056] It has been verified that the super hydrophilic self-cleaning silicone resin coating obtained in this embodiment has no significant difference in performance compared with the coating obtained in Example 1, and both have good super hydrophilic properties, photocatalytic self-cleaning properties, hardness, adhesion and other mechanical properties and high transmittance.

[0057] Example 5: (1) Preparation of nano-SiO2 film-forming material: Add silicate (methyl orthosilicate: butyl orthosilicate = 1:1), ethanol, and nano-silicon dioxide aqueous dispersion into a reaction container in sequence, mix well at room temperature, then slowly add concentrated hydrochloric acid to the above solution, stir at 300 rpm for 3 h to allow it to undergo a hydrolysis reaction, and obtain nano-SiO2 film-forming material. The mass ratio of the raw materials is 1.5:5:0.5:0.03.

[0058] (2) Preparation of nano-metal oxide dispersion: Add nano-titanium dioxide and nano-zirconia into deionized water, stir evenly, and ultrasonically oscillate at 25°C-45°C for 30 min to obtain a uniformly dispersed nano-metal oxide dispersion, wherein the ratio of nano-titanium dioxide: nano-zirconia: deionized water is 0.6:0.6:100.

[0059] (3) Preparation of silicone resin diluent: Add silicone resin into ethanol and disperse it. After stirring evenly, add silane coupling agent γ-methacryloxypropyltrimethoxysilane and stir again for 30 min. The mass ratio of ethanol: silicone resin: silane coupling agent is 25:5:1 to obtain silicone resin diluent. The ratio of each component in the silicone resin is methyl silicone resin: phenyl silicone resin: methyl phenyl silicone resin = 3:2:5.

[0060] (4) Preparation of co-solvent: ethanol, n-propanol and isobutanol were mixed in a mass ratio of 4:3:3 and stirred to obtain a co-solvent.

[0061] (5) Take 15 mL of the above-prepared nano-SiO2 film-forming material, 7 mL of nano-metal oxide dispersion, and 0.15 g of film-forming aid, add 70 mL of co-solvent, shake for 30 min until uniform, then add 10 mL of silicone resin diluent and 0.5 g of wetting agent, and stir for 30 min to obtain a super hydrophilic self-cleaning silicone resin coating.

[0062] (6) The prepared super hydrophilic self-cleaning silicone resin coating was sprayed on the glass surface using a spray gun. The obtained coating sample was cured at room temperature for 24 h to obtain a super hydrophilic self-cleaning silicone resin coating.

[0063] Example 6: (1) Preparation of nano-SiO2 film-forming material: Add silicate (ethyl orthosilicate:propyl orthosilicate = 1:1), ethanol and nano-silicon dioxide aqueous dispersion into a reaction container in sequence, mix well at room temperature, then slowly add concentrated hydrochloric acid to the above solution, stir at 300 rpm for 3 h to allow it to undergo a hydrolysis reaction, and obtain nano-SiO2 film-forming material. The mass ratio of the raw materials is 1.5:5:0.5:0.03.

[0064] (2) Preparation of nano-metal oxide dispersion: Add nano-titanium dioxide and nano-aluminum oxide into deionized water, stir evenly, and ultrasonically oscillate at 25°C-45°C for 30 min to obtain a uniformly dispersed nano-metal oxide dispersion, wherein the ratio of nano-titanium dioxide: nano-aluminum oxide: deionized water is 0.5:0.6:100.

[0065] (3) Preparation of silicone resin diluent: Add silicone resin into ethanol to disperse, stir evenly, add silane coupling agent γ-aminopropyltriethoxysilane, and stir again for 30 min, wherein the mass ratio of ethanol: silicone resin: silane coupling agent is 25:5:1, to obtain silicone resin diluent, and the ratio of each component in the silicone resin is methyl silicone resin: phenyl silicone resin: methylphenyl silicone resin = 5:3:2.

[0066] (4) Preparation of co-solvent: ethanol, n-propanol and isobutanol were mixed in a mass ratio of 4:3:3 and stirred to obtain a co-solvent.

[0067] (5) Take 20 mL of the above-prepared nano-SiO2 film-forming material, 5 mL of nano-metal oxide dispersion, and 0.1 g of film-forming aid, add 55 mL of co-solvent, shake for 30 min until uniform, then add 20 mL of silicone resin diluent and 0.75 g of wetting agent, and stir for 30 min to obtain a super hydrophilic self-cleaning silicone resin coating.

[0068] (6) The prepared super hydrophilic self-cleaning silicone resin coating was sprayed on the glass surface using a spray gun. The obtained coating sample was cured at room temperature for 24 h to obtain a super hydrophilic self-cleaning silicone resin coating.

[0069] Example 7: (1) Preparation of nano-SiO2 film-forming material: Add silicate (ethyl orthosilicate: butyl orthosilicate = 1:1), ethanol and nano-SiO2 aqueous dispersion into a reaction container in sequence, mix well at room temperature, then slowly add concentrated hydrochloric acid to the above solution, stir at 300 rpm for 3 h to allow it to undergo a hydrolysis reaction, and obtain nano-SiO2 film-forming material. The mass ratio of the raw materials is 1.5:5:0.5:0.03.

[0070] (2) Preparation of nano-metal oxide dispersion: Add nano-titanium dioxide and nano-cerium oxide into deionized water, stir evenly, and then ultrasonically oscillate at 25°C-45°C for 30 min to obtain a uniformly dispersed nano-metal oxide dispersion, wherein the ratio of nano-titanium dioxide: nano-cerium oxide: deionized water is 0.4:0.5:100.

[0071] (3) Preparation of silicone resin diluent: Add silicone resin into ethanol to disperse, stir evenly, add silane coupling agent γ-aminopropyltriethoxysilane, and stir again for 30 min, wherein the mass ratio of ethanol: silicone resin: silane coupling agent is 25:5:1, and silicone resin diluent is obtained. The ratio of each component in the silicone resin is methyl silicone resin: phenyl silicone resin: methylphenyl silicone resin = 3:2:5.

[0072] (4) Preparation of co-solvent: ethanol, n-propanol and isobutanol were mixed in a mass ratio of 4:3:3 and stirred to obtain a co-solvent.

[0073] (5) Take 25 mL of the above-prepared nano-SiO2 film-forming material, 8 mL of nano-metal oxide dispersion, and 0.2 g of film-forming aid, add 50 mL of co-solvent, shake for 30 min until uniform, then add 20 mL of silicone resin diluent and 1 g of wetting agent, and stir for 30 min to obtain a super hydrophilic self-cleaning silicone resin coating.

[0074] (6) The prepared super hydrophilic self-cleaning silicone resin coating was sprayed on the glass surface using a spray gun. The obtained coating sample was cured at room temperature for 24 h to obtain a super hydrophilic self-cleaning silicone resin coating.

[0075] Comparative Example 1: This comparative example provides a coating, which is different from Example 1 only in that the coating does not contain a wetting agent, and the other components and amounts are the same as those in Example 1.

[0076] This comparative example provides a method for preparing the coating, and the specific steps are the same as those in Example 1.

[0077] The prepared composite coating was sprayed on the glass surface using a spray gun, and the obtained coating sample was cured at room temperature for 24 hours to obtain a super hydrophilic self-cleaning silicone resin coating.

[0078] Comparative Example 2: This comparative example provides a coating, which is different from Example 1 only in that no silane coupling agent is added to the silicone resin diluent in the coating, and other components and amounts are the same as those in Example 1.

[0079] This comparative example provides a method for preparing the coating, and the specific steps are the same as those in Example 1.

[0080] The prepared composite coating was sprayed on the glass surface using a spray gun, and the obtained coating sample was cured at room temperature for 24 hours to obtain a super hydrophilic self-cleaning silicone resin coating.

[0081] Comparative Example 3: This comparative example provides a coating, which is different from Example 1 only in that no nano-silicon dioxide is added to the nano-SiO2 film-forming material in the coating, and other components and amounts are the same as those in Example 1.

[0082] This comparative example provides a method for preparing the coating, and the specific steps are the same as those in Example 1.

[0083] The prepared composite coating was sprayed on the glass surface using a spray gun, and the obtained coating sample was cured at room temperature for 24 hours to obtain a super hydrophilic self-cleaning silicone resin coating.

[0084] Comparative Example 4: This comparative example provides a coating, which is different from Example 1 only in that all components in the coating are directly mixed without being treated, and the dosage is the same as that in Example 1.

[0085] This comparative example provides a method for preparing the coating, and the specific steps are the same as those in Example 1.

[0086] The prepared composite coating was sprayed on the glass surface using a spray gun, and the obtained coating sample was cured at room temperature for 24 hours to obtain a super hydrophilic self-cleaning silicone resin coating.

[0087] Performance test: The super-hydrophilic self-cleaning silicone resin coatings provided in Examples 5-7 and Comparative Examples 1-4 were subjected to performance tests using the same testing methods as in Examples 1-3. The results are shown in Table 1.

[0088] Table 1 Contact angle (°) Transmittance (%) Adhesion hardness Example 5 8.3 90.4-95.3% Level 0 6H Example 6 8.5 90.0-95.1% Level 0 6H Example 7 10.5 90.3-95.2% Level 0 6H Comparative Example 1 76 90.4-95.6% Level 0 6H Comparative Example 2 8.2 90.4-95.8% Level 1 5H Comparative Example 3 11.5 89.5-94.5% Level 1 6H Comparative Example 4 18.7 84.5-89.5% Level 2 4H It has been verified that the super hydrophilic self-cleaning silicone resin coatings obtained in Examples 5-7 have no significant difference in performance compared with the coating obtained in Example 1, and both have good super hydrophilic properties, photocatalytic self-cleaning properties, hardness, adhesion and other mechanical properties and high transmittance.

[0089] As can be seen from Comparative Example 1, without adding a wetting agent, the hydrophilicity of the coating is poor. As can be seen from Comparative Example 2, the coating prepared with an uncrosslinked silicone resin has reduced adhesion and hardness. As can be seen from Comparative Example 3, the coating without adding nano-silicon dioxide has reduced hydrophilicity and adhesion. As can be seen from Comparative Example 4, the coating obtained by directly mixing all the raw material components has reduced hydrophilicity, transmittance, adhesion and hardness, indicating that the components in this application need to be prepared by an appropriate method to obtain a super-hydrophilic self-cleaning silicone resin coating with better performance.

[0090] The above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the principles of the above description, and the obvious changes or modifications made on this basis are still within the scope of protection of the present invention.

Claims

1. A super hydrophilic self-cleaning silicone resin coating, characterized in that: The coating comprises the following components by mass fraction: 10-20% of organic silicon resin diluent, 3-8% of photocatalytic material, 15-25% of nano-SiO2 film-forming material, 0.5%-1% of wetting agent, 0.1-0.2% of film-forming aid, and 50%-65% of co-solvent; wherein the organic silicon resin diluent is a uniform dispersion formed by cross-linking the organic silicon resin with a silane coupling agent; the photocatalytic material is a nano-metal oxide dispersion; and the nano-SiO2 film-forming material is an acidic hydrolysis sol containing a silicate and a nano-silicon dioxide dispersion.

2. The super hydrophilic self-cleaning silicone resin coating according to claim 1, characterized in that: The organic silicone resin diluent is obtained by dissolving silicone resin and silane coupling agent in an organic solvent; wherein the mass ratio of the organic solvent, silicone resin and silane coupling agent is 25-100:5-10:

1.

3. The super hydrophilic self-cleaning silicone resin coating according to claim 2, characterized in that: The silicone resin includes any one of methyl silicone resin, phenyl silicone resin and methylphenyl silicone resin.

4. The super hydrophilic self-cleaning silicone resin coating according to claim 2, characterized in that: The silane coupling agent includes any one of γ-aminopropyltriethoxysilane, γ-glycidyloxypropyltrimethoxysilane or γ-methacryloxypropyltrimethoxysilane.

5. The super hydrophilic self-cleaning silicone resin coating according to claim 2, characterized in that: The organic solvent is any one or more of ethanol, acetone, n-butanol, isobutanol, propylene glycol methyl ether, ethylene glycol butyl ether, n-propanol and methanol.

6. The super hydrophilic self-cleaning silicone resin coating according to claim 1, characterized in that: The wetting agent is one or more of sodium olefin sulfonate, sodium dodecyl sulfate, sodium octadecylbenzene sulfonate, and sodium dodecyl sulfonate.

7. The super hydrophilic self-cleaning silicone resin coating according to claim 1, characterized in that: The photocatalytic material is a water dispersion of any one or more of nano titanium dioxide, nano zinc oxide, nano tin oxide, nano zirconium oxide, nano aluminum oxide, and nano cerium oxide, with a concentration of 8-12 g / L.

8. The super hydrophilic self-cleaning silicone resin coating according to claim 1, characterized in that: The nano-SiO2 film-forming material is prepared by the following method: adding silicate, nano-silicon dioxide aqueous dispersion and ethanol in sequence, with a mass ratio of 5-10:2-6:10-25, stirring at a temperature of 25°C-40°C to make the mixture uniform, and then slowly adding concentrated hydrochloric acid, wherein the mass ratio of concentrated hydrochloric acid to nano-silicon dioxide aqueous dispersion is 1:15-30, and continuing stirring for 3 hours to obtain the nano-SiO2 film-forming material; the silicate is any one or more of methyl orthosilicate, ethyl orthosilicate, propyl orthosilicate and butyl orthosilicate.

9. The method for preparing the super hydrophilic self-cleaning silicone resin coating according to any one of claims 1 to 8, characterized in that: include: At room temperature, adding photocatalytic material and nano-SiO2 film-forming material into a solvent and mixing and stirring to obtain a mixed material; The mixed material is mixed with a silicone resin diluent, a wetting agent and a film-forming aid are added, and the mixture is evenly mixed by magnetic stirring to form a white transparent solution, thereby obtaining a super-hydrophilic self-cleaning silicone resin coating.

10. An application of a super hydrophilic self-cleaning silicone resin coating, characterized in that: The super-hydrophilic self-cleaning silicone resin coating as described in claims 1-8 is suitable for coating the hard surfaces of solar photovoltaic panel cover glass, building walls or large billboards to adsorb and decompose organic pollutants to achieve self-cleaning.

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