阅读说明：本技术 一种自清洁户外水性纳米氧化锡锑-二氧化硅/硅丙复合透明隔热涂料及其制备方法 (Self-cleaning outdoor water-based nano tin antimony oxide-silicon dioxide/silicon acrylic composite transparent heat-insulating coating and preparation method thereof ) 是由 张心亚 柯澳爵 谭振华 李晓敏 张�浩 于 2021-07-13 设计创作，主要内容包括：本发明属于水性涂料技术领域。涉及一种自清洁户外水性ATO-SiO-(2)/硅丙复合透明隔热涂料及其制备方法。所述水性ATO-SiO-(2)/硅丙复合透明隔热涂料的制备过程包括如下步骤：将ATO、分散剂和水混合制备均匀的ATO分散液；然后将正硅酸乙酯溶于所述ATO分散液中,并且加入苯酮类紫外吸收剂制备ATO-SiO-(2)复合溶胶；利用硅烷偶联剂作为有机硅单体以及半连续种子引发方法制备水性硅丙乳液。最后将水性硅丙乳液、纳米氧化锡锑-二氧化硅复合溶胶、成膜剂等助剂均匀混合制备ATO-SiO-(2)/硅丙复合透明隔热涂料。所述ATO-SiO-(2)/硅丙复合透明隔热涂料的制备方法能够制备得到符合国家环保标准,拥有高附着力、漆膜硬度和高可见光透光率,以及优异的耐水性、耐候性与隔热性能的涂料。(The invention belongs to the technical field of water-based paint. Relates to self-cleaning outdoor water-based ATO-SiO 2 Silicon-acrylic composite transparent heat-insulating coating and preparation method thereof. The aqueous ATO-SiO 2 The preparation process of the silicon-acrylic composite transparent heat-insulating coating comprises the following steps: mixing ATO, a dispersant and water to prepare a uniform ATO dispersion liquid; then dissolving ethyl orthosilicate in the ATO dispersion liquid, and adding benzophenone ultraviolet absorbent to prepare ATO-SiO 2 Compounding sol; the aqueous silicone-acrylate emulsion is prepared by using a silane coupling agent as an organic silicon monomer and a semi-continuous seed initiation method. Finally, evenly mixing the water-based silicone-acrylic emulsion, the nano tin antimony oxide-silicon dioxide composite sol, the film-forming agent and other auxiliary agents to prepare ATO-SiO 2 Silicon-acrylic composite transparent heat-insulating coating. The ATO-SiO 2 The preparation method of the silicon-acrylic composite transparent heat-insulating coating can prepare the coating which meets the national environmental protection standard, has high adhesive force, high film hardness and high visible light transmittance, and has excellent water resistance, weather resistance and heat-insulating property.)

1. A preparation method of a self-cleaning outdoor water-based nano tin antimony oxide-silicon dioxide/silicon acrylic composite transparent heat-insulating coating is characterized by comprising the following steps:

mixing and stirring nanometer tin antimony oxide, a dispersing agent and water to prepare nanometer tin antimony oxide dispersion liquid;

dissolving ethyl orthosilicate in the nano tin antimony oxide dispersion liquid, adding a nitric acid aqueous solution with the mass concentration of 10% -13%, mixing, adding a benzophenone ultraviolet absorbent, stirring, standing and aging to prepare nano tin antimony oxide-silicon dioxide composite sol;

mixing the water-based silicone acrylic emulsion, the nano tin antimony oxide-silicon dioxide composite sol, an auxiliary agent and water to prepare the water-based nano tin antimony oxide-silicon dioxide/silicone acrylic composite transparent heat-insulating coating;

the mass percent of silicon in the water-based silicone-acrylate emulsion is 1.7-3.2%.

2. The preparation method of the self-cleaning outdoor water-based nano tin antimony oxide-silica/silicone acrylic composite transparent heat insulation coating as claimed in claim 1, wherein the preparation method of the water-based silicone acrylic emulsion comprises the following steps:

adding an emulsifier into water, stirring and heating to obtain a water phase;

mixing methyl methacrylate, butyl acrylate, hydroxyethyl acrylate, methacrylic acid and an initiator to obtain a mixture;

and adding part of the mixture into the water phase to serve as seeds, preserving heat until blue light appears in the water phase, adding the rest mixture, continuing to react, then adding a silane coupling agent, and adjusting the pH value of the system to prepare the water-based silicone-acrylate emulsion.

3. The preparation method of the self-cleaning outdoor water-based nano tin antimony oxide-silica/silicon acrylic composite transparent heat insulation coating as claimed in claim 2, wherein the silane coupling agent is one or more selected from gamma- (methacryloyloxy) propyl trimethoxy silane, vinyl trimethoxy silane and vinyl triethoxy silane.

4. The preparation method of the self-cleaning outdoor water-based nano tin antimony oxide-silicon dioxide/silicon acrylic composite transparent heat-insulating coating as claimed in claim 2, wherein the mass ratio of the methyl methacrylate, the butyl acrylate, the hydroxyethyl acrylate, the methacrylic acid and the silane coupling agent is (50-65): (20-35): (0.2-5): (0.2-2): (5-10).

5. The preparation method of the self-cleaning outdoor water-based nano tin antimony oxide-silicon dioxide/silicon acrylic composite transparent heat insulation coating as claimed in claim 2, wherein the initiator is azobisisobutyronitrile.

6. The preparation method of the self-cleaning outdoor water-based nano tin antimony oxide-silicon dioxide/silicon acrylic composite transparent heat insulation coating as claimed in any one of claims 1 to 5, wherein the particle size of the nano tin antimony oxide is less than or equal to 10 nm.

7. The preparation method of the self-cleaning outdoor water-based nano tin antimony oxide-silicon dioxide/silicon acrylic composite transparent heat insulation coating as claimed in any one of claims 1 to 5, wherein the dispersant is a mixture of a tertiary amine type dispersant and a silane dispersant.

8. The preparation method of the self-cleaning outdoor water-based nano tin antimony oxide-silicon dioxide/silicon acrylic composite transparent heat insulation coating as claimed in any one of claims 1 to 5, wherein the tertiary amine type dispersant is selected from one or more of triethanolamine, N-dimethylethanolamine and triethylamine;

the silane dispersing agent is selected from one or more of gamma- (methacryloyloxy) propyl trimethoxy silane, vinyl trimethoxy silane and vinyl triethoxy silane.

9. The preparation method of the self-cleaning outdoor water-based nano tin antimony oxide-silicon dioxide/silicon acrylic composite transparent heat insulation coating as claimed in any one of claims 1 to 5, wherein the mass ratio of the ethyl orthosilicate, the nano tin antimony oxide dispersion, the nitric acid and the benzophenone ultraviolet absorbent is (0.5-1.0): (10-20): (0.2-0.4): (0.1-0.5).

10. The method for preparing a self-cleaning outdoor water-based nano tin antimony oxide-silica/silicon acrylic composite transparent heat insulation coating as claimed in any one of claims 1 to 5, wherein the benzophenone-based ultraviolet absorbent is selected from one or more of 2, 4-dihydroxybenzophenone, oxybenzophenone and 2-hydroxy-4-n-octoxybenzophenone.

11. The preparation method of the self-cleaning outdoor water-based nano tin antimony oxide-silica/silicon acrylic composite transparent heat insulation coating as claimed in any one of claims 1 to 5, wherein the particle size of the nano tin antimony oxide-silica composite sol is less than or equal to 30 nm.

12. The preparation method of the self-cleaning outdoor water-based nano tin antimony oxide-silica/silicon acrylic composite transparent heat-insulating coating as claimed in any one of claims 1 to 5, wherein the mass ratio of the water-based silicone acrylic emulsion, the nano tin antimony oxide-silica composite sol and the auxiliary agent is (50-90): (5-45): (5-10).

13. The self-cleaning outdoor water-based nano tin antimony oxide-silicon dioxide/silicon acrylic composite transparent heat insulation coating prepared by the preparation method of any one of claims 1 to 12.

Technical Field

The invention belongs to the technical field of water-based paint. Relates to a self-cleaning outdoor water-based nano tin antimony oxide-silicon dioxide/silicon acrylic composite transparent heat-insulating coating and a preparation method thereof.

Background

Energy consumption of modern buildings is always high, and the result of a Chinese building energy consumption research report issued in 2017 shows that the proportion of the energy consumption of the buildings accounts for 30-40% of the total energy consumption of human beings. It is worth noting that in the total energy consumption of China, the building energy consumption accounts for about 20%, and most of the electricity consumption comes from the energy consumption of heating and air conditioning. The energy lost through the door and the window accounts for half of the energy consumption of the whole building heating and air conditioning. Therefore, if the high energy consumption problem of modern buildings is to be solved, one of the important solutions is to perform targeted heat insulation and preservation measures on doors and windows. In recent years, for the purpose of beautiful appearance and better lighting effect, large-area glass curtain walls and windows are adopted for decoration in the buildings in China. Therefore, on the original basis, the improvement of the heat preservation and insulation effect of the building glass is undoubtedly the next better solution.

In the research and development of the heat insulation technology of glass, relevant researchers at home and abroad do a lot of work. Such as vacuum glass, hollow glass, and film-coated insulating glass, which are currently commercially available. However, these products are not suitable for wide application on building glass in large area due to short service life, high cost, low transmittance in visible light region, and difficult control of production process.

The nano transparent heat insulation coating is taken as one of the means for insulating and saving energy of glass, and is concerned by the scientific research community and the society in recent years. The transparent heat-insulating coating consists of nanometer transparent conductive oxide and high molecular film-forming resin. The nanometer transparent conductive oxide is one of the important components of the transparent heat-insulating coating, has higher transmittance in a visible light region and has good capability of shielding infrared light wavelength in an infrared light region, so that the heat-insulating effect is good. The transparent heat-insulating water-based paint also has the advantages of simple preparation process, environmental friendliness, low price and the like, indicates a direction for development of transparent heat insulation, and has wide market prospect.

Chinese patent CN 111849330A (application number: 202010703833.X) provides' a nano ATO/TiO of ultra-low VOC aqueous polyurethane/acrylic acid transparent building glass₂Transparent heat insulation coating ", in this invention, two kinds of slurry are prepared: nano tin antimony oxide (ATO) slurry and titanium dioxide (TiO)₂) The slurry is used as a heat insulation filler, and the waterborne polyurethane/acrylic resin is used as a high-molecular film forming resin, so that the heat insulation coating with high adhesive force, excellent paint film mechanical property, water resistance and weather resistance is prepared. Chinese patent CN 111040523A (201911298846.7) provides 'a high-adhesion water-based transparent heat-insulation glass coating and a preparation method thereof', and a heat-insulation water-based coating with high adhesion and low heat conductivity coefficient is prepared by using water-based styrene-acrylic emulsion and organic silicon modified acrylic emulsion as film-forming resin, ATO as heat-insulation filler and the like. According to the technical scheme, two kinds of slurry are required to be prepared in the former, the process is complex, the solid content of the slurry is high, and the performance of a paint film is not good. The latter coating has poor water resistance after film formation (cracking and discoloration appear after 3 d), and the hardness is only 2H, which is not beneficial to long-term outdoor exposure.

Disclosure of Invention

Based on the above, there is a need for providing a self-cleaning outdoor water-based nano tin antimony oxide-silica/silicon acrylic composite transparent heat-insulating coating which has high adhesion and paint film hardness, good water resistance and weather resistance, good heat-insulating effect and can keep good light transmittance in a visible light region.

A self-cleaning outdoor water-based nano tin antimony oxide-silicon dioxide/silicon acrylic composite transparent heat insulation coating and a preparation method thereof comprise the following steps:

mixing ATO, a dispersant and water, and stirring to prepare an ATO dispersion liquid;

dissolving ethyl orthosilicate in the ATO dispersion liquid, adding a nitric acid aqueous solution with the mass concentration of 10% -13%, mixing, adding a benzophenone ultraviolet absorbent, stirring, standing and aging to prepare nano tin antimony oxide-silicon dioxide (ATO-SiO)₂) Compounding sol;

mixing the aqueous silicone-acrylate emulsion and the ATO-SiO₂Mixing the composite sol, the auxiliary agent and water to prepare the water-based ATO-SiO₂Silicon-acrylic composite transparent heat-insulating coating;

the mass percent of silicon in the water-based silicone-acrylate emulsion is 1.7-3.2%

The preparation method of the water-based silicone-acrylate emulsion comprises the following steps:

adding an emulsifier into water, stirring and heating to obtain a water phase;

mixing methyl methacrylate, butyl acrylate, hydroxyethyl acrylate, methacrylic acid and an initiator to obtain a mixture;

and adding part of the mixture into the water phase to be used as seeds, reacting, keeping the temperature until blue light appears in the water phase, adding the rest mixture into the water phase to continue reacting, then adding a silane coupling agent, and adjusting the pH value of the system to prepare the water-based silicone-acrylate emulsion.

In one embodiment, the silane coupling agent is selected from one or more of gamma- (methacryloyloxy) propyltrimethoxysilane, vinyltrimethoxysilane, and vinyltriethoxysilane.

In one embodiment, the mass ratio of the methyl methacrylate, the butyl acrylate, the hydroxyethyl acrylate, the methacrylic acid and the silane coupling agent is (50-65): (20-35): (0.2-5): (0.2-2): (5-10).

In one embodiment, the initiator is azobisisobutyronitrile.

In one embodiment, the emulsifier is a mixture of sodium lauryl sulfate and a nonionic emulsifier, which is Dow chemical 15-S-40.

In one embodiment, the incubation time is 1 hour; the pH value of the system is 7-8.

In one embodiment, the ATO has a particle size of 10nm or less.

In one embodiment, the dispersant is a mixture of a tertiary amine type dispersant and a silane dispersant;

the tertiary amine type dispersing agent is selected from one or more of triethanolamine, N-dimethylethanolamine and triethylamine;

the silane dispersing agent is selected from one or more of gamma- (methacryloyloxy) propyl trimethoxy silane, vinyl trimethoxy silane and vinyl triethoxy silane.

In one embodiment, the mass ratio of ATO, the dispersant and water is (5-10): (0.2-0.7): (20-30).

In one embodiment, the ATO is prepared by a hydrothermal method.

In one embodiment, ATO-SiO₂In a composite sol, SiO₂And ATO in a mass ratio of 1: 10.

In one embodiment, the mass ratio of the ethyl orthosilicate, the ATO dispersion liquid, the nitric acid and the benzophenone ultraviolet absorber is (0.5-1.0): (10-20): (0.2-0.4): (0.1-0.5).

In one embodiment, the benzophenone-based uv absorber is selected from one or more of 2, 4-dihydroxybenzophenone, oxybenzophenone, and 2-hydroxy-4-n-octoxybenzophenone.

In one embodiment, the ATO-SiO₂Composite solThe grain diameter is less than or equal to 30 nm.

In one embodiment, the auxiliary agent is selected from one or more of a film forming auxiliary agent, a defoaming agent and a leveling agent.

In one embodiment, the mass ratio of the auxiliary agent is (5-8): (0.01-0.03): (0.1-0.3) a mixture of a film-forming aid, a defoaming agent and a leveling agent;

the film-forming assistant is dodecyl alcohol ester, the defoaming agent is BYK-019, and the leveling agent is BYK-333.

In one embodiment, the aqueous silicone-acrylic emulsion, ATO-SiO₂The mass ratio of the composite sol to the auxiliary agent is (50-90): (5-35): (5-10).

The invention also provides the self-cleaning outdoor water-based ATO-SiO prepared by the preparation method₂Silicon-acrylic composite transparent heat-insulating coating.

Compared with the prior art, the invention has the following beneficial effects:

the invention firstly utilizes the dispersing agent and the stirring method to prepare the ATO into the dispersion liquid, and can effectively improve the uniformity, the heat insulation performance and the like of the coating prepared by the coating. The reason is that the ATO nano particles have large specific surface area and high surface activity, and the particles are easy to agglomerate to form agglomerates. If the ATO nano powder is directly dispersed in the base material to prepare the coating, on one hand, the nano powder can not be uniformly dispersed in the base material; on the other hand, the agglomerates are difficult to open, the thermal insulation performance of the nanopowder is not good, and the uniformity, optical and electrical properties of the obtained coating are also greatly affected. Therefore, the invention firstly prepares ATO dispersion liquid, and further prepares the obtained ATO-SiO by hydrolyzing tetraethoxysilane in the ATO dispersion liquid₂The composite sol further reduces soft agglomeration among ATOs by grafting silicon dioxide on the surface of ATO, is beneficial to dispersion of ATO particles, and enables the ATO nanoparticles to better realize heat insulation performance. And due to the formation of ATO-SiO₂Sols, on the one hand, are based on silicon dioxide (SiO)₂) A large number of hydrophobic structure chemical bonds exist in the coating, which is beneficial to improving the self-cleaning property of the coating, and on the other hand, SiO₂The same as the main component of the substrate of glass,can form chemical bond with the surface of the glass, thereby greatly improving the adhesion on the glass. In order to improve the light transmittance of the coating in the visible light region, a benzophenone ultraviolet absorber is also introduced into the application. In addition, the invention prepares the silicone-acrylate emulsion with high silicon content, and the silicone-acrylate emulsion with high silicon content and the ATO-SiO₂Mixing the composite sol to obtain aqueous ATO-SiO₂The silicon-acrylic composite sol transparent heat insulation coating. The high content of silicon in the silicone-acrylate emulsion is beneficial to improving the adhesive force between the coating and the glass substrate and the hardness of the coating. And the coating can also fully utilize the characteristics of weather resistance, pollution resistance, antistatic property, high transparency and the like of the high-silicon silicone-acrylic emulsion. Therefore, the obtained coating has good heat insulation performance, the hardness of the coating is as high as 4H, and the coating has excellent self-cleaning performance, water resistance, weather resistance and the like.

Drawings

FIG. 1 is a process flow diagram of a method of preparing a coating;

FIG. 2 shows aqueous ATO-SiO solutions of examples and comparative examples₂A thermal insulation test result chart of the silicon-acrylic composite transparent thermal insulation coating.

Detailed Description

In order that the invention may be more fully understood, reference will now be made to the following description taken in conjunction with the accompanying drawings. The detailed description sets forth the preferred embodiments of the invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

Unless otherwise stated or contradicted, terms or phrases used herein have the following meanings:

as used herein, the term "and/or", "and/or" includes any one of two or more of the associated listed items, as well as any and all combinations of the associated listed items, including any two of the associated listed items, any more of the associated listed items, or all combinations of the associated listed items.

As used herein, "one or more" means any one, any two, or any two or more of the listed items. Wherein, the 'several' means any two or more than any two.

Herein, "preferred" merely describes a more effective embodiment or example, and it should be understood that the scope of the present invention is not limited thereto.

In the present invention, the technical features described in the open type include a closed technical solution composed of the listed features, and also include an open technical solution including the listed features.

In the present invention, the numerical range is defined to include both end points of the numerical range unless otherwise specified.

Referring to FIG. 1, the present invention provides an aqueous ATO-SiO₂The silicon-acrylic composite transparent heat-insulating coating and the preparation method thereof comprise the following steps:

s101: mixing ATO, a dispersant and deionized water, and stirring to prepare an ATO dispersion liquid.

Further, in step S101, the particle size of ATO is not more than 10 nm.

Further, in step S101, the dispersant is a mixture of a tertiary amine type dispersant and a silane dispersant;

further, the tertiary amine type dispersant is selected from one or more of triethanolamine, N-dimethylethanolamine and triethylamine;

the silane dispersing agent is selected from one or more of gamma- (methacryloyloxy) propyl trimethoxy silane, vinyl trimethoxy silane and vinyl triethoxy silane.

Further, in the step S101, the mass ratio of ATO, the dispersing agent and water is (5-10): (0.2-0.7): (20-30).

Further, in step S101, ATO is prepared by a hydrothermal method.

The invention mixes ATO, dispersant and water, and obtains evenly dispersed ATO dispersion liquid in a mode of ultrasonic dispersion for 30min and then stirring for 1h-2 h. Firstly, ATO prepared by a hydrothermal method does not need to be calcined at high temperature, has small particle size and monodispersity, and is beneficial to dispersion, while ATO prepared by other methods is easy to generate hard agglomeration, and the application of ATO on coating glass can influence the light transmittance, heat insulation performance and the like of a paint film. Compared with the coating prepared by directly dispersing the ATO nano powder in the base material, the coating has the advantages that on one hand, the nano powder cannot be uniformly dispersed in the base material and is easy to agglomerate; on the other hand, the agglomerates are difficult to open, thereby affecting the uniformity of the coating, the heat insulation performance, and the like.

S102: dissolving tetraethoxysilane in the ATO dispersion liquid, adding a nitric acid aqueous solution with the mass concentration of 10-13%, mixing, adding a benzophenone ultraviolet absorbent, stirring, standing for aging, and preparing ATO-SiO₂And (4) compounding the sol.

Further, in step S102: ATO-SiO₂In a composite sol, SiO₂And ATO in a mass ratio of 1: 10.

further, in step S102: the mass ratio of the ethyl orthosilicate to the ATO dispersion liquid to the nitric acid to the benzophenone ultraviolet absorbent is (0.5-1.0): (10-20): (0.2-0.4): (0.1-0.5).

Further, in step S102: the benzophenone ultraviolet absorbent is selected from one or more of 2, 4-dihydroxy benzophenone, oxybenzone and 2-hydroxy-4-n-octoxy benzophenone.

Further, in step S102, at room temperature, the mixture is stirred for 12 hours and then placed for aging for 24 hours to promote ATO-SiO₂And (4) forming a composite sol.

Further, ATO-SiO₂The particle size of the composite sol is less than or equal to 30 nm;

the invention adds tetraethoxysilane into ATO dispersion liquid, and utilizes tetraethoxysilane to hydrolyze to prepare the obtained ATO-SiO₂The composite sol has silica grafted on ATThe characteristics of the O surface. If the ethyl orthosilicate is hydrolyzed to prepare silicon dioxide and then the silicon dioxide is mixed with the ATO dispersion liquid, the obtained dispersion liquid is a mixture of ATO and silicon dioxide, wherein the silicon dioxide sol is not grafted to the surface of ATO, and has no dispersion effect on ATO. The invention has the advantages that ATO-SiO₂The characteristic structure of the composite sol further reduces soft agglomeration among ATOs, is beneficial to dispersion of ATO particles, and fully exerts the performance of the nanometer heat-insulating oxide. At the same time, because of the formation of ATO-SiO₂Sol having the same composition SiO as the glass substrate₂And SiO₂Can form a chemical bond with the surface of the glass, thereby improving the adhesion of the coating on the glass.

S103: preparing an aqueous silicone-acrylic emulsion comprising the steps of:

adding an emulsifier into water, stirring and heating to obtain a water phase;

mixing methyl methacrylate, butyl acrylate, hydroxyethyl acrylate, methacrylic acid and an initiator to obtain a mixture;

and adding part of the mixture into the water phase to be used as seeds, reacting, keeping the temperature until blue light appears in the water phase, adding the rest mixture into the water phase to continue reacting, then adding a silane coupling agent, and adjusting the pH value of the system to prepare the water-based silicone-acrylate emulsion.

Further, in step S103, the silane coupling agent is selected from one or more of gamma- (methacryloyloxy) propyltrimethoxysilane (silane coupling agent KH-570), vinyltrimethoxysilane (silane coupling agent A-171), and vinyltriethoxysilane (silane coupling agent A-151).

Further, in step S103, the mass ratio of methyl methacrylate, butyl acrylate, hydroxyethyl acrylate, methacrylic acid and the silane coupling agent is (50 to 65): (20-30): (0.2-5): (0.2-2): (5-10).

Further, in step S103, the initiator is azobisisobutyronitrile.

Further, in step S103, the emulsifier is a mixture of sodium lauryl sulfate and a nonionic emulsifier, and further, the nonionic emulsifier is dow chemical 15-S-40.

Further, in step S103, the water phase is stirred and heated to 80 ℃, the time of blue light generation by heat preservation is 1 hour, the time of continuous reaction of the remaining mixture is 2-3 hours, the reaction temperature is 80 ℃, the reaction time is about 1 hour after the silane coupling agent is added, and the heat preservation is continued for 1 hour after the reaction is completed to ensure that the monomers are completely reacted.

Further, in step S103, the pH value of the ammonia water adjusting system is 7-8.

In the present invention, in order to improve the adhesion of a paint film to glass, hardness, weather resistance and the like, it is necessary to modify the aqueous silicone-acrylic emulsion with a silane coupling agent and to increase the content of the silane coupling agent, so that it is necessary to control the time for adding the silane coupling agent. In particular, since the silane coupling agent is added in an excessive amount at the early stage, gel is easily generated during the emulsion polymerization. And if the silane coupling agent is added in the seed reaction stage, the mass fraction of the silane coupling agent in the formula cannot exceed 5%. Therefore, the adding time of the silane coupling agent is controlled at the later stage of the reaction, which not only is favorable for reducing the gel rate, but also ensures that the silane coupling agent is coated on the outer surface of the silicone-acrylic emulsion latex particles, so that the silane coupling agent can be better attached to a glass substrate to react with the glass substrate, and the adhesive force is improved.

S104: mixing the aqueous silicone-acrylate emulsion and the ATO-SiO₂Mixing the composite sol, the auxiliary agent and water to prepare ATO-SiO₂Composite silicone-acrylic emulsion transparent heat-insulating coating.

Further, in step S104, aqueous silicone-acrylic emulsion, ATO-SiO₂The mass ratio of the composite sol to the auxiliary agent is (50-90): (5-35): (5-10).

Further, in step S104, the auxiliary agent is one or more selected from a film forming auxiliary agent, a defoaming agent, and a leveling agent.

Further, in the step S104, the mass ratio of the auxiliary agent is (5-8): (0.01-0.03): (0.1-0.3) a mixture of a film-forming aid, a defoaming agent and a leveling agent.

Further, in step S104, the coalescing agent is a dodecanol ester.

Further, in step S104, the defoaming agent is BYK-019.

Further, in step S104, the leveling agent is BYK-333.

Further, in step S104, the mixing method is magnetic stirring, and the magnetic stirring time is 30 min.

The preparation method of the coated glass of the coating comprises the following steps:

respectively scrubbing float glass by using 10% sodium hydroxide and 10% sulfuric acid in mass fraction, then washing with deionized water for 2-3 times, and drying for later use.

Transparent heat insulation paint is coated on float glass with the thickness of 100mm multiplied by 3mm by using the surfaces with different thicknesses of a BGD four-side preparation device, samples with the coating film thickness of 30um, 60um, 90um and 120um are prepared, and the film is formed for 3 days in an electrothermal blowing constant-temperature drying oven at the temperature of 80 ℃.

According to the standard: the paint film properties were tested.

The visible light transmittance of the paint film was measured using a Hitachi UV-3900 UV-visible spectrophotometer.

And (3) testing the heat insulation effect of the heat insulation coating by using a self-made temperature difference testing instrument.

The hardness of the coating was tested according to the national standard GB/T6739-1996.

The adhesion of the coating was tested by the cross-hatch method, according to the specifications of the national standard GB/T9286-1998.

The water resistance of the coating was tested as specified in the national Standard GB/T1733-1993A method.

The acid resistance of the coating was tested as specified in the national standard GB/T9274-1988A.

The coatings were tested for alkali resistance as specified in the national standard GB/T9274-1998A.

The invention discloses a self-cleaning outdoor water-based ATO-SiO₂The coating is prepared from the self-cleaning outdoor water-based ATO-SiO₂The silicon-acrylic composite transparent heat-insulating coating is prepared by a preparation method. The invention adopts transparent conductive oxide material ATO and ultraviolet isolated ATO-SiO₂The composite sol is compounded, and ATO-SiO is added with benzophenone ultraviolet absorbent because ATO has good capability of isolating ultraviolet and infrared light₂The composite sol can well shield the influence of ultraviolet rays, and is favorable for improving the visible light property of the coating. And SiO₂Can form-Si-O-Si-chemical bond with the glass surface, has good combination with the glass substrate, and can increase the adhesive force of the coating on the glass substrate; in addition, the ATO-SiO is prepared by hydrolyzing tetraethoxysilane in ATO dispersion liquid₂The composite sol is also beneficial to the dispersion of ATO, reduces the agglomeration of ATO to a certain extent, and better exerts the heat-insulating property of ATO and the like. Simultaneously, the silicone-acrylic emulsion modified by the silane coupling agent and ATO-SiO₂The single-component water-based green environment-friendly silicon-acrylic transparent heat-insulating glass coating prepared by blending the composite sol meets the national environmental protection quality requirements, has high visible light transmittance and excellent heat-insulating property, and has good adhesive force, water resistance, weather resistance and the like on glass.

The following are specific examples:

example 1

This example provides a self-cleaning outdoor aqueous ATO-SiO₂The silicon-acrylic composite transparent heat-insulating coating comprises the following steps:

(1) preparation of ATO Dispersion

According to the mass parts, 10.0 parts of ATO synthesized by a hydrothermal method, 0.1 part of triethanolamine, 0.1 part of vinyltrimethoxysilane and 20 parts of deionized water are subjected to normal-temperature ultrasonic dispersion for 0.5 hour, and are mixed and stirred for 2-3 hours to prepare a uniform ATO dispersion liquid.

(2)ATO-SiO₂Preparation of composite sols

Taking 1.0 part by mass of ethyl orthosilicate, dissolving the ethyl orthosilicate in 20.0 parts by mass of ATO dispersion liquid, adding 0.2 part by mass of 10% nitric acid aqueous solution, uniformly mixing, finally adding 0.1 part by mass of 2, 4-dihydroxy benzophenone, stirring for 12 hours, and standing for 24 hours for aging; the whole experimental procedure was carried out at room temperature.

(3) Preparation of silane coupling agent modified silicone-acrylic emulsion

1.2g of sodium dodecyl sulfate and 0.6g of Dow chemical 15-S-40 nonionic emulsifier were added to 180g of deionized water, and the mixture was stirred and heated to 80 ℃ to obtain an aqueous phase.

Uniformly mixing 63g of methyl methacrylate, 28g of butyl acrylate, 0.5g of hydroxyethyl acrylate, 0.5g of methacrylic acid and 0.8g of azobisisobutyronitrile to obtain a mixture;

adding 15g of the mixture into the water phase as seeds by adopting a semi-continuous seed initiation method, carrying out heat preservation reaction for 1 hour until blue light appears in the water phase, adding the rest mixture, carrying out reaction for 2-3 hours at the temperature of 80 ℃, then adding 8g of silane coupling agent KH-570, and carrying out heat preservation for 1 hour after the reaction is carried out for 1 hour to ensure that the monomers are completely reacted. And finally, adjusting the pH of the system to 7-8 by using ammonia water to prepare the aqueous silicone-acrylate emulsion. The mass percent of silicon in the aqueous silicone-acrylic emulsion was found to be 2.8%.

(4)ATO-SiO₂Preparation of silicon-acrylic composite transparent heat-insulating coating

According to the mass portion, 6.0 portions of ATO-SiO₂Mixing the composite sol, 55.0 parts of water-based silicone-acrylic emulsion, 5.0 parts of dodecanol ester, 0.01 part of BYK-019, 0.1 part of BYK-333 and 33.89 parts of water, and then magnetically stirring for 0.5 hour to uniformly disperse the mixture to prepare ATO-SiO₂Silicon-acrylic composite transparent heat-insulating coating.

Example 2

This example provides a self-cleaning outdoor aqueous ATO-SiO₂The silicon-acrylic composite transparent heat-insulating coating comprises the following steps:

(1) preparation of ATO Dispersion

According to the mass parts, 10.0 parts of ATO synthesized by a hydrothermal method, 0.1 part of triethanolamine, 0.1 part of vinyltrimethoxysilane and 20 parts of deionized water are subjected to normal-temperature ultrasonic dispersion for 0.5 hour, and are mixed and stirred for 2-3 hours to prepare a uniform ATO dispersion liquid.

(2)ATO-SiO₂Preparation of composite sols

Taking 1.0 part by mass of ethyl orthosilicate, dissolving the ethyl orthosilicate in 20.0 parts by mass of ATO dispersion liquid, adding 0.2 part by mass of 10% nitric acid aqueous solution, uniformly mixing, finally adding 0.1 part by mass of 2, 4-dihydroxy benzophenone, stirring for 12 hours, and standing for 24 hours for aging; the whole experimental procedure was carried out at room temperature.

(3) Preparation of silane coupling agent modified silicone-acrylic emulsion

1.2g of sodium dodecyl sulfate and 0.6g of Dow chemical 15-S-40 nonionic emulsifier were added to 180g of deionized water, and the mixture was stirred and heated to 80 ℃ to obtain an aqueous phase.

Uniformly mixing 63g of methyl methacrylate, 28g of butyl acrylate, 0.5g of hydroxyethyl acrylate, 0.5g of methacrylic acid and 0.8g of azobisisobutyronitrile to obtain a mixture;

adding 15g of mixture into the water phase as seeds by adopting a semi-continuous seed initiation method, carrying out heat preservation reaction for 1 hour until blue light appears in the water phase, adding the rest mixture, carrying out reaction for 2-3 hours at the temperature of 80 ℃, then adding 8g of silane coupling agent KH-570, and carrying out heat preservation for 1 hour after the reaction is carried out for 1 hour to ensure that the monomers are completely reacted. And finally, adjusting the pH of the system to 7-8 by using ammonia water to prepare the aqueous silicone-acrylate emulsion. The mass percent of silicon in the aqueous silicone-acrylic emulsion was found to be 2.8%.

(4)ATO-SiO₂Preparation of silicon-acrylic composite transparent heat-insulating coating

According to the mass fraction, 12 parts of ATO-SiO₂Mixing the composite sol, 55.0 parts of water-based silicone-acrylic emulsion, 5.0 parts of dodecanol ester, 0.01 part of BYK-019, 0.1 part of BYK-333 and 27.89 parts of water, and magnetically stirring for 0.5 hour to uniformly disperse the mixture to prepare ATO-SiO₂Silicon-acrylic composite transparent heat-insulating coating.

Example 3

This example provides a self-cleaning outdoor aqueous ATO-SiO₂The silicon-acrylic composite transparent heat-insulating coating comprises the following steps:

(1) preparation of ATO Dispersion

According to the mass parts, 10.0 parts of ATO synthesized by a hydrothermal method, 0.1 part of triethanolamine, 0.1 part of vinyltrimethoxysilane and 20 parts of deionized water are subjected to normal-temperature ultrasonic dispersion for 0.5 hour, and are mixed and stirred for 2-3 hours to prepare a uniform ATO dispersion liquid.

(2)ATO-SiO₂Preparation of composite sols

Taking 1.0 part by mass of ethyl orthosilicate, dissolving the ethyl orthosilicate in 20.0 parts by mass of ATO dispersion liquid, adding 0.2 part by mass of 10% nitric acid aqueous solution, uniformly mixing, finally adding 0.1 part by mass of 2, 4-dihydroxy benzophenone, stirring for 12 hours, and standing for 24 hours for aging; the whole experimental procedure was carried out at room temperature.

(3) Preparation of silane coupling agent modified silicone-acrylic emulsion

1.2g of sodium dodecyl sulfate and 0.6g of Dow chemical 15-S-40 nonionic emulsifier were added to 180g of deionized water, and the mixture was stirred and heated to 80 ℃ to obtain an aqueous phase.

Uniformly mixing 63g of methyl methacrylate, 28g of butyl acrylate, 0.5g of hydroxyethyl acrylate, 0.5g of methacrylic acid and 0.8g of azobisisobutyronitrile to obtain a mixture;

adding 15g of mixture into the water phase as seeds by adopting a semi-continuous seed initiation method, carrying out heat preservation reaction for 1 hour until blue light appears in the water phase, adding the rest mixture, carrying out reaction for 2-3 hours at the temperature of 80 ℃, then adding 8g of silane coupling agent KH-570, and carrying out heat preservation for 1 hour after the reaction is carried out for 1 hour to ensure that the monomers are completely reacted. And finally, adjusting the pH of the system to 7-8 by using ammonia water to prepare the aqueous silicone-acrylate emulsion. The mass percent of silicon in the aqueous silicone-acrylic emulsion was found to be 2.8%.

(4)ATO-SiO₂Preparation of silicon-acrylic composite transparent heat-insulating coating

According to the mass portion, 24 portions of ATO-SiO₂Mixing the composite sol, 55.0 parts of water-based silicone-acrylic emulsion, 5.0 parts of dodecanol ester, 0.01 part of BYK-019, 0.1 part of BYK-333 and 15.89 parts of water, and magnetically stirring for 0.5 hour to uniformly disperse the mixture to prepare ATO-SiO₂Silicon-acrylic composite transparent heat-insulating coating.

Comparative example 1

This comparative example provides a self-cleaning outdoor aqueous ATO-SiO₂The silicon-acrylic composite transparent heat-insulating coating is basically the same as the coating in the embodiment 1, and the main difference is that the silane coupling agent is used in the preparation process of the water-based silicon-acrylic emulsionThe dosage is different, and the steps are as follows:

(1) preparation of ATO Dispersion

According to the mass parts, 10.0 parts of ATO synthesized by a hydrothermal method, 0.1 part of triethanolamine, 0.1 part of vinyltrimethoxysilane and 20 parts of deionized water are subjected to normal-temperature ultrasonic dispersion for 0.5 hour, and are mixed and stirred for 2-3 hours to prepare a uniform ATO dispersion liquid.

(2)ATO-SiO₂Preparation of composite sols

Taking 1.0 part by mass of ethyl orthosilicate, dissolving the ethyl orthosilicate in 20.0 parts by mass of ATO dispersion liquid, adding 0.2 part by mass of 10% nitric acid aqueous solution, uniformly mixing, finally adding 0.1 part by mass of 2, 4-dihydroxy benzophenone, stirring for 12 hours, and standing for 24 hours for aging; the whole experimental procedure was carried out at room temperature.

(3) Preparation of silane coupling agent modified silicone-acrylic emulsion

1.2g of sodium dodecyl sulfate and 0.6g of Dow chemical 15-S-40 nonionic emulsifier were added to 180g of deionized water, and the mixture was stirred and heated to 80 ℃ to obtain an aqueous phase.

Uniformly mixing 63g of methyl methacrylate, 28g of butyl acrylate, 0.5g of hydroxyethyl acrylate, 0.5g of methacrylic acid and 0.8g of azobisisobutyronitrile to obtain a mixture;

adding 15g of mixture into the water phase as seeds by adopting a semi-continuous seed initiation method, carrying out heat preservation reaction for 1 hour until blue light appears in the water phase, adding the rest mixture, carrying out reaction for 2-3 hours at the temperature of 80 ℃, then adding 3g of silane coupling agent KH-570, and carrying out heat preservation for 1 hour after the reaction is carried out for 1 hour to ensure that the monomers are completely reacted. And finally, adjusting the pH of the system to 7-8 by using ammonia water to prepare the aqueous silicone-acrylate emulsion. The mass percent of silicon in the aqueous silicone-acrylic emulsion was found to be 1.0%.

(4)ATO-SiO₂Preparation of silicon-acrylic composite transparent heat-insulating coating

According to the mass portion, 6.0 portions of ATO-SiO₂Mixing the composite sol, 55.0 parts of water-based silicone-acrylic emulsion, 5.0 parts of dodecanol ester, 0.01 part of BYK-019, 0.1 part of BYK-333 and 33.89 parts of water, and magnetically stirring for 0.5 hour to uniformly disperse the mixture to prepare the nano-composite nano-particlesObtaining ATO-SiO₂Silicon-acrylic composite transparent heat-insulating coating.

Comparative example 2

This comparative example provides a self-cleaning outdoor aqueous ATO-SiO₂The silicon-acrylic composite transparent heat-insulating coating is basically the same as the coating in the example 1, and the main difference is that ATO-SiO is not added₂Compounding sol, which comprises the following steps:

(1) preparation of silane coupling agent modified silicone-acrylic emulsion

By mass, 1.2g of sodium lauryl sulfate and 0.6g of Dow chemical 15-S-40 nonionic emulsifier were added to 180g of deionized water, and the mixture was stirred and heated to 80 ℃ to obtain an aqueous phase.

Uniformly mixing 63g of methyl methacrylate, 28g of butyl acrylate, 0.5g of hydroxyethyl acrylate, 0.5g of methacrylic acid and 0.8g of azobisisobutyronitrile to obtain a mixture;

adding 15g of mixture into the water phase as seeds by adopting a semi-continuous seed initiation method, carrying out heat preservation reaction for 1 hour until blue light appears in the water phase, adding the rest mixture, carrying out reaction for 2-3 hours at the temperature of 80 ℃, then adding 8g of silane coupling agent KH-570, and carrying out heat preservation for 1 hour after the reaction is carried out for 1 hour to ensure that the monomers are completely reacted. And finally, adjusting the pH of the system to 7-8 by using ammonia water to prepare the aqueous silicone-acrylate emulsion. The mass percent of silicon in the aqueous silicone-acrylic emulsion was found to be 2.8%.

(2) Preparation of water-based silicone-acrylic emulsion heat-insulating coating

55 parts of water-based silicone-acrylic emulsion, 5.0 parts of dodecanol ester, 0.01 part of BYK-019, 0.1 part of BYK-333 and 39.89 parts of water are mixed according to parts by weight, and then are stirred by magnetic force for 0.5 hour to be dispersed uniformly, so that the water-based silicone-acrylic emulsion heat insulation coating is prepared.

Finally, the coated glass prepared from the coatings of examples 1-3 and comparative examples 1-2 above was prepared by the following steps:

respectively scrubbing float glass by using 10% sodium hydroxide and 10% sulfuric acid in mass fraction, then washing with deionized water for 2-3 times, and drying for later use.

A transparent heat-insulating coating is coated on float glass with the thickness of 100mm multiplied by 3mm by using surfaces with different thicknesses of a BGD four-side preparation device to prepare a sample with the coating thickness of 30um, and the sample is subjected to film formation in an electric heating air blowing constant-temperature drying oven at the temperature of 80 ℃ for 3 days.

Performance test

The thermal insulation coatings of examples 1-3 and comparative examples 1-2 were tested according to the following test standards, and the specific test results are shown in table 1 and fig. 2;

the visible light transmittance of the paint film was measured using a Hitachi UV-3900 UV-visible spectrophotometer.

And (3) testing the heat insulation effect of the heat insulation coating by using a self-made temperature difference testing instrument.

The hardness of the coating was tested according to the national standard GB/T6739-1996.

The adhesion of the coating was tested by the cross-hatch method, according to the specifications of the national standard GB/T9286-1998.

The water resistance of the coating was tested as specified in the national Standard GB/T1733-1993A method.

The acid resistance of the coating was tested as specified in the national standard GB/T9274-1988A.

The coatings were tested for alkali resistance as specified in the national standard GB/T9274-1998A.

Table 1 and FIG. 2 show the hardness, adhesion, visible light transmittance, water resistance, weather resistance, heat insulation and the like of the coating films of the examples and comparative examples. Combining FIG. 2 with Table 1: in the examples, the coating film had excellent heat-insulating properties of 16.1 ℃ while maintaining good visible light transmittance. Further, it was found that the coating film had a hardness of up to 4H, an adhesion of 0 grade, and also had excellent water resistance (neither paint film 7d foamed nor discolored) and weather resistance. Comparative example 2 is a blank control with no ATO-SiO added₂Composite sol, obtained by comparison with examples 1-3, ATO-SiO₂The addition of the composite sol can not only improve the hardness of a paint film, but also improve the adhesive force of the paint film on glass. The amount of the silane coupling agent added in comparative example 1 is less than that in example 1, and as can be seen from table 1 and fig. 2, although the heat insulating properties are not different between comparative example 1 and example 1, the hardness and adhesion properties are graded by 1-2The decrease indicates that the increase of the addition amount of the silane coupling agent is beneficial to improving the hardness and the adhesion of the paint film.

TABLE 1

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.