Preparation method of pure inorganic high-emission high-transmission anti-ultraviolet radiation refrigeration coating

Abstract

The application relates to the technical field of refrigeration coating, and discloses a preparation method of a pure inorganic high-emission high-transmittance anti-ultraviolet radiation refrigeration coating, which comprises the following steps: S1, coating a high-emission mixed sol on a glass substrate, solidifying to obtain a first layer of film; S2, coating a high-emission mixed sol on the surface of the first layer of film, solidifying to obtain a second layer of film; S3, coating a high-refraction isolation layer sol on the surface of the second layer of film, solidifying to obtain a third layer of film; S4, coating a high-emission mixed sol on the surface of the third layer of film, solidifying to obtain a fourth layer of film, and finally obtaining the pure inorganic high-emission high-transmittance anti-ultraviolet radiation refrigeration coating which comprises the first layer of film, the second layer of film, the third layer of film and the fourth layer of film from bottom to top. Through the technical scheme, the problems of low radiation emissivity and poor refrigeration effect of the refrigeration coating in the related art are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of refrigeration coating, in particular to a preparation method of a pure inorganic high-emission high-transmission anti-ultraviolet radiation refrigeration coating. BACKGROUND

[0002] As a passive cooling method, the radiation refrigeration technology can radiate heat to outer space through infrared rays by utilizing the atmospheric transparent window (8-13 μm), so as to realize the surface cooling of an object. The best effect of the radiation refrigeration is to realize high infrared emission in the atmospheric window band and high sunlight reflection in the sunlight band (0.3-2.5 μm).

[0003] The SiO2 material is a good infrared radiation material because it has a strong vibration absorption peak in the 8-13 μm band and has a relatively high emissivity in the band. However, the intrinsic infrared emissivity (0.93) of the SiO2 material in the atmospheric window band is still quite different from that of an ideal selective radiator (infrared emissivity of 1.0), which makes the radiation emissivity of the refrigeration coating with SiO2 as the main infrared radiation material still need to be improved, and the refrigeration effect needs to be further improved. In addition, the existing SiO2 material is usually compounded with a polymer matrix as an organic radiation refrigeration material, but the organic polymer refrigeration material has insufficient resistance to ultraviolet rays and is prone to photodegradation when exposed to ultraviolet rays for a long time, which causes the refrigeration coating to become brittle and further affects the refrigeration effect.

[0004] Therefore, it is of great significance to develop a pure inorganic refrigeration coating that has resistance to ultraviolet rays and high radiation emissivity, thereby having good refrigeration effect, to meet the use requirements of the refrigeration coating and prolong the service life of the refrigeration coating. SUMMARY

[0005] The present application provides a preparation method of a pure inorganic high-emission high-transmission anti-ultraviolet radiation refrigeration coating, which solves the problems of low radiation emissivity and poor refrigeration effect of the refrigeration coating in the related art.

[0006] The technical scheme of the present application is as follows:

[0007] The present application provides a preparation method of a pure inorganic high-emission high-transmission anti-ultraviolet radiation refrigeration coating, which includes the following steps:

[0008] S1, coating a high-emission mixed sol on a glass substrate to form a first layer of film;

[0009] S2, coating a high-emission mixed sol on the surface of the first layer of film to form a second layer of film;

[0010] S3, coating a high-refraction isolation layer sol on the upper surface of the second layer film, and curing to obtain a third layer film;

[0011] S4, coating a high-emission mixed sol on the upper surface of the third layer film, and curing to obtain a fourth layer film, thereby finally obtaining a pure inorganic high-emission high-transmission anti-ultraviolet radiation refrigeration coating layer comprising the first layer film, the second layer film, the third layer film and the fourth layer film in sequence from bottom to top.

[0012] The raw materials of the high-emission mixed sol include core-shell structure nanoparticles, yttrium-doped silica particles and a binder.

[0013] As a further technical solution, the preparation method of the yttrium-doped silica particles comprises the following steps:

[0014] A1, mixing tetraethyl orthosilicate and ethanol, adding a water-soluble yttrium salt, and mixing uniformly to obtain a precursor solution;

[0015] A2, mixing ethanol, an alkali solution, water and cetyltrimethylammonium bromide to obtain a mixed solution, adding the precursor solution dropwise into the mixed solution, and mixing uniformly to obtain a suspension;

[0016] A3, aging the suspension, centrifuging, collecting the precipitate, drying the precipitate, sintering, and crushing to obtain the yttrium-doped silica particles.

[0017] In the present application, the water-soluble yttrium salt is introduced into the tetraethyl orthosilicate precursor solution for preparing silica particles, and the Si-O-Y bond is formed on the surface by hydrolysis of the silanol molecules in the alkali solution, which disturbs the uniform hydrolysis of the tetraethyl orthosilicate precursor solution, so that the formed silica particles become irregular, and finally the yttrium-doped silica particles with uneven morphology are obtained.

[0018] As a further technical solution, the weight ratio of the tetraethyl orthosilicate and the water-soluble yttrium salt is 10:0.3~0.5.

[0019] In the present application, when the weight ratio of the tetraethyl orthosilicate and the water-soluble yttrium salt is 10:0.3~0.5, the radiation emissivity of the refrigeration coating layer can be further improved, and the refrigeration effect is further improved.

[0020] As a further technical solution, the water-soluble yttrium salt includes one or more of yttrium chloride, yttrium nitrate and yttrium sulfate, and preferably yttrium chloride.

[0021] As a further technical solution, in step A1, when blending, the stirring speed is 300-400 rpm, for example, it can be 300 rpm, 320 rpm, 350 rpm, 380 rpm, 400 rpm, preferably 300 rpm, 350 rpm, 400 rpm, more preferably 350 rpm, and the stirring time is 15-25 min, for example, it can be 15 min, 20 min, 25 min.

[0022] As a further technical solution, the weight ratio of tetraethyl orthosilicate, cetyltrimethylammonium bromide and water is 10:5-15:1-2.

[0023] As a further technical solution, in steps A1 and A2, the amount of ethanol added is independently 3-4 times the mass of tetraethyl orthosilicate.

[0024] As a further technical solution, the alkali solution includes one of sodium hydroxide solution, ammonia solution and potassium hydroxide solution, preferably ammonia solution.

[0025] In the present application, when the alkali solution is ammonia solution, the mass fraction of the ammonia solution is 8%-15%, for example, it can be 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, preferably 12%.

[0026] As a further technical solution, the amount of alkali solution added is calculated based on the pH value of the mixed solution being 9-10.

[0027] As a further technical solution, in step A2, when dropping, the dropping speed is 7-8 mL / min;

[0028] When the mixture is uniform, the stirring speed is 400-600 rpm, for example, it can be 400 rpm, 450 rpm, 500 rpm, 550 rpm, 600 rpm, preferably 500 rpm, and the stirring time is 1.5-2.5 h, for example, it can be 1.5 h, 2 h, 2.5 h, preferably 2 h.

[0029] As a further technical solution, in step A3, when aging, the time is 2-4 h, for example, it can be 2 h, 2.5 h, 3 h, 3.5 h, 4 h, preferably 3 h;

[0030] The sintering temperature is 750-900 DEG C, for example, it can be 750 DEG C, 800 DEG C, 850 DEG C, 900 DEG C, preferably 750 DEG C, 800 DEG C, 900 DEG C, more preferably 800 DEG C, and the sintering time is 1-2h, for example, it can be 1h, 1.5h, 2h;

[0031] The pulverization is to pulverize the yttrium-doped silicon dioxide particles to an average particle size of 100-200nm, for example, it can be 100nm, 120nm, 140nm, 160nm, 180nm, 200nm, preferably 160nm.

[0032] As a further technical solution, the preparation method of the core-shell structure nanoparticles comprises the following steps: after blending tetraethyl orthosilicate, benzene propyl emulsion and water, adding an acidic catalyst, reacting, standing, heat preservation treatment, to obtain the core-shell structure nanoparticles.

[0033] The weight ratio of the tetraethyl orthosilicate, the benzene propyl emulsion, the acidic catalyst and the water is 1:1-5:0.05-0.15:1-5.

[0034] As a further technical solution, the heat preservation treatment temperature is 400-450 DEG C, for example, it can be 400 DEG C, 410 DEG C, 420 DEG C, 430 DEG C, 440 DEG C, 450 DEG C, preferably 400 DEG C, and the heat preservation treatment time is 0.5-1.5h, for example, it can be 0.5h, 1h, 1.5h, preferably 1h.

[0035] In the preparation method of the core-shell structure nanoparticles, tetraethyl orthosilicate is used as a reaction precursor, and benzene propyl emulsion is used as a template agent. The benzene propyl emulsion template agent can guide the directional deposition of silanol after the hydrolysis of the tetraethyl orthosilicate precursor on its surface, so as to form a shell on the surface of the emulsion microspheres through hydrolysis and crosslinking. After heat preservation treatment at 400-450 DEG C, the benzene propyl emulsion is decomposed to form a hollow structure silicon dioxide particle. The decomposition of the benzene propyl emulsion can also make the surface-deposited silicon dioxide particle form a mesoporous structure, so as to finally form a core-shell structure nanoparticle with a hollow structure and a mesoporous structure.

[0036] As a further technical solution, in the preparation method of the core-shell structure nanoparticles, the reaction is stirred at a speed of 400-600rpm, for example, it can be 400rpm, 450rpm, 500rpm, 550rpm, 600rpm, preferably 500rpm, and the stirring time is 1-5h, for example, it can be 1h, 2h, 3h, 4h, 5h, preferably 3h.

[0037] The standing time is 20-70h, for example, it can be 20h, 30h, 40h, 50h, 60h, 70h, preferably 30h.

[0038] As a further technical solution, the preparation method of the adhesive comprises the following steps: after the tetraethyl orthosilicate, methyl trialkoxysilane, template agent and solvent are blended, an acidic catalyst is added, reacted to obtain a sol solution, and the sol solution is aged to obtain the adhesive.

[0039] The weight ratio of the tetraethyl orthosilicate, methyl trialkoxysilane, solvent, template agent, and acidic catalyst is 1:1-5:10-60:5-10:0.01-0.15.

[0040] In the preparation method of the adhesive, the tetraethyl orthosilicate is used as a main reaction precursor, and the methyl trialkoxysilane is used as a secondary reaction precursor, and under the action of the polyethylene glycol or cetyltrimethylammonium bromide template agent and the acidic catalyst, the adhesive with a certain viscosity can be obtained.

[0041] As a further technical solution, the methyl trialkoxysilane includes one or both of methyltrimethoxysilane and methyltriethoxysilane.

[0042] As a further technical solution, the template agent includes one or both of polyethylene glycol and cetyltrimethylammonium bromide.

[0043] As a further technical solution, the solvent includes one of anhydrous ethanol and isopropyl alcohol, and the anhydrous ethanol is preferred.

[0044] As a further technical solution, in the preparation method of the adhesive, during the reaction, the stirring is performed at a speed of 400-600 rpm, for example, 400 rpm, 450 rpm, 500 rpm, 550 rpm, 600 rpm, and the speed of 500 rpm is preferred, and the stirring is performed for 12-24 h, for example, 12 h, 14 h, 16 h, 18 h, 20 h, 22 h, 24 h, and the time of 18 h is preferred.

[0045] As a further technical solution, in steps S1, S2 and S4, the preparation method of the high-emission mixed sol independently comprises the following steps:

[0046] The core-shell structure nanoparticles, yttrium-doped silica particles and adhesive are uniformly mixed and aged to obtain the high-emission mixed sol.

[0047] The weight ratio of the core-shell structure nanoparticles, yttrium-doped silica particles and adhesive is 3:2:15-25.

[0048] As a further technical solution, in the preparation method of the high-refraction isolation layer sol, when the mixing is uniform, the stirring speed is 200-300 rpm, for example, it can be 200 rpm, 250 rpm, 300 rpm, and the stirring time is 1-3 h, for example, it can be 1 h, 2 h, 3 h.

[0049] As a further technical solution, the preparation method of the high-refraction isolation layer sol includes the following steps:

[0050] The titanium source, glacial acetic acid, acid catalyst, and solvent are uniformly mixed, reacted to obtain a sol liquid, and the sol liquid is aged to obtain the high-refraction isolation layer sol.

[0051] As a further technical solution, the solvent includes ethanol and water.

[0052] As a further technical solution, the titanium source includes one of tetraethyl titanate and tetrabutyl titanate.

[0053] As a further technical solution, the weight ratio of the titanium source, glacial acetic acid, acid catalyst, ethanol, and water is 1:0.01-0.1:0.01-0.03:10-50:0.5-1.

[0054] As a further technical solution, in the preparation method of the high-refraction isolation layer sol, when the mixing is uniform, the stirring speed is 200-300 rpm, for example, it can be 200 rpm, 250 rpm, 300 rpm, and the stirring time is 1-3 h, for example, it can be 1 h, 2 h, 3 h.

[0055] As a further technical solution, in the preparation method of the binder, the preparation method of the high-emission mixed sol, and the preparation method of the high-refraction isolation layer sol, the aging time is independently 1-7 d, for example, it can be 1 d, 2 d, 3 d, 4 d, 5 d, 6 d, 7 d, and preferably 3 d.

[0056] As a further technical solution, in the preparation method of the core-shell structure nanoparticle, the preparation method of the binder, and the preparation method of the high-refraction isolation layer sol, the acid catalyst independently includes one of hydrochloric acid, acetic acid, citric acid, and nitric acid, and preferably hydrochloric acid.

[0057] In the present application, when the acid catalyst is hydrochloric acid, the hydrochloric acid is a dilute hydrochloric acid solution with a mass fraction of 5%-10%, for example, it can be 5%, 6%, 7%, 8%, 9%, 10%, and preferably 8%.

[0058] As a further technical solution, the raw material of the high-emission mixed sol further includes barium titanate.

[0059] As a further technical solution, the added amount of the barium titanate is 8% to 15% of the weight sum of the core-shell structure nanoparticles and the yttrium-doped silica particles, for example, can be 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, and preferably 10%.

[0060] In the present application, in order not to affect the visible light transmittance of the refrigeration coating, the added amount of the barium titanate is relatively small, which is 8% to 15% of the weight sum of the core-shell structure nanoparticles and the yttrium-doped silica particles.

[0061] As a further technical solution, the barium titanate includes barium titanate I and barium titanate II with a weight ratio of 3:1 to 2;

[0062] The specific surface area of the barium titanate I is 10 to 20 m 2 / g, and the specific surface area of the barium titanate II is 2 to 4 m 2 / g.

[0063] In the present application, the inventors found that when a small amount of barium titanate with a specific surface area of 10 to 20 m 2 / g and a specific surface area of 2 to 4 m 2 / g is further included in the raw material of the high-emission mixed sol, the corrosion resistance of the refrigeration coating can be improved by using two kinds of barium titanate with different specific surface areas, and the possible reason is that: the specific surface area of the barium titanate with a specific surface area of 10 to 20 m 2 / g is relatively high, and has more active sites, which can have good interaction with the core-shell structure nanoparticles and the yttrium-doped silica particles in the high-emission mixed sol, and the barium titanate with a specific surface area of 2 to 4 m 2 / g is relatively low, and is more uniformly dispersed in the high-emission mixed sol system, and the use of barium titanate with different specific surface areas makes the structure of the high-emission mixed sol film more dense, thereby improving the resistance of the refrigeration coating to external corrosive media. By optimizing the content ratio of the two kinds of barium titanate with different specific surface areas, when the weight ratio of the barium titanate with a specific surface area of 10 to 20 m 2 / g and the barium titanate with a specific surface area of 2 to 4 m 2 / g is 3:1 to 2, the corrosion resistance of the refrigeration coating can be further improved.

[0064] As a further technical solution, the thickness of the first layer film is 400 to 600 nm;

[0065] The thickness of the second layer film is 300 to 500 nm;

[0066] The thickness of the third layer film is 10 to 60 nm;

[0067] The fourth layer film has a thickness of 300-500 nm.

[0068] In the present application, by reasonably regulating the thickness of the first layer film, the second layer film, the third layer film and the fourth layer film, the radiation emissivity of the refrigeration coating is improved, and the refrigeration effect is improved.

[0069] As a further technical solution, in steps S1, S2, S3 and S4, the temperature is independently 400-500 DEG C, for example, it can be 400 DEG C, 450 DEG C, 500 DEG C, and the time is independently 1-3 h, for example, it can be 1 h, 2 h, 3 h.

[0070] The working principle and beneficial effects of the present application are as follows:

[0071] 1、In the present application, the first layer film, the second layer film and the fourth layer film are prepared by using high-emission mixed sol, and the third layer film is formed by using high-refraction isolation layer sol, finally forming a pure inorganic high-emission high-transmission ultraviolet radiation prevention refrigeration coating including the first layer film, the second layer film, the third layer film and the fourth layer film from bottom to top, through the synergistic effect of the multi-layer film structure, the refrigeration coating has high radiation emissivity in the "atmospheric window" of 8-13 mu m, and has good reflectivity near ultraviolet light (250-400 nm), so that the prepared refrigeration coating can release heat in the form of infrared radiation, and can reduce the absorption of solar radiation to a certain extent, inhibit the temperature rise of the coating itself, and thus the refrigeration coating has good refrigeration effect.

[0072] 2. The raw material of the high-emission mixed sol includes core-shell structure nanoparticles, yttrium-doped silica particles and a binder, the core-shell structure nanoparticles are silica nanoparticles with hollow structures and mesoporous structures generated by the decomposition of a styrene-acrylic emulsion, the hollow structures and mesoporous structures exist simultaneously, which greatly increases the specific surface area and increases the number of pores inside the film layer, the increase of these pore defects enhances the scattering and absorption of infrared radiation inside, which improves the radiation emissivity of the high-emission mixed sol formed film, but the intrinsic infrared emissivity (radiation emissivity of about 0.93) of silica in the atmospheric window is relatively low, so the improvement of the radiation emissivity of the high-emission mixed sol formed film containing only the core-shell structure nanoparticles is limited. In order to solve this problem, yttrium-doped silica particles are introduced, by doping yttrium in the silica, Si-O-Y bonds can be formed in the silica particles, which disturbs the uniform hydrolysis and condensation process of the precursor during the formation of the silica particles, thereby enhancing the asymmetry of the silica particle structure and improving the intrinsic infrared emissivity of the silica in the atmospheric window, so that the radiation emissivity of the high-emission mixed sol formed film containing yttrium-doped silica particles is improved, and combined with the core-shell structure nanoparticles with hollow structures and mesoporous structures, the refrigeration coating ultimately has good radiation emissivity.

[0073] 3. The third layer film formed by the high-refraction isolation layer sol can play a role in resisting ultraviolet light, has good reflectivity near ultraviolet light (250-400 nm), and can inhibit the temperature rise of the coating itself to a certain extent, thereby laying a foundation for the refrigeration coating to have good refrigeration effect. BRIEF DESCRIPTION OF DRAWINGS

[0074] The application will be described in further detail below with reference to the drawings and specific embodiments.

[0075] Figure 1 The infrared transmittance test graph of the refrigeration coating prepared in Example 1;

[0076] Figure 2 The reflectivity test graph of the refrigeration coating prepared in Example 1. DETAILED DESCRIPTION

[0077] The technical solutions in the embodiments of the application will be described clearly and completely below with reference to the embodiments of the application. Obviously, the described embodiments are only a part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the application.

[0078] In the following examples and comparative examples, the type of polyethylene glycol is PEG400; the type of styrene-acrylic emulsion is BLJ-8000T, which is purchased from Can Sen New Material (Shenzhen) Co., Ltd.

[0079] Example 1

[0080] The preparation method of the core-shell structure nanoparticles comprises the following steps: after 10 g of tetraethyl orthosilicate, 10 g of styrene-acrylic emulsion and 10 g of water are blended, 0.5 g of 8% mass fraction dilute hydrochloric acid solution is added, stirring is carried out at 500 rpm for 3 h, standing is carried out for 30 h, and heat preservation is carried out at 400℃ for 1 h to obtain the core-shell structure nanoparticles.

[0081] The preparation method of the binder comprises the following steps: after 10 g of tetraethyl orthosilicate, 10 g of methyltrimethoxysilane, 50 g of polyethylene glycol and 100 g of anhydrous ethanol are blended, 0.5 g of 8% mass fraction dilute hydrochloric acid solution is added, stirring is carried out at 500 rpm for 18 h to obtain a sol solution, and the sol solution is aged for 3 d to obtain the binder.

[0082] The preparation method of the yttrium-doped silicon dioxide particles comprises the following steps:

[0083] A1. 100 g of tetraethyl orthosilicate and 300 g of ethanol are stirred at 300 rpm for 25 min, 1 g of yttrium chloride is added, stirring is carried out at 40℃ and 200 rpm for 2.5 h to obtain a precursor solution;

[0084] A2. 300 g of ethanol, 10 g of water and 50 g of cetyltrimethylammonium bromide are blended, and a 12% mass fraction ammonia water solution is added to obtain a mixed solution with a pH of 9, the precursor solution is added dropwise to the mixed solution at a dropwise adding speed of 7 mL / min, and stirring is carried out at 500 rpm for 2 h to obtain a suspension;

[0085] A3. The suspension is aged for 3 h, centrifuged, the precipitate is collected, dried and sintered at 750℃ for 2 h, and then cooled to room temperature and crushed to obtain yttrium-doped silicon dioxide particles with an average particle size of 160 nm;

[0086] The preparation method of the high-emission mixed sol comprises the following steps: 3 g of the core-shell structure nanoparticles, 2 g of the yttrium-doped silicon dioxide particles and 15 g of the binder are stirred at 200 rpm for 12 h, and aged for 3 d to obtain a high-emission mixed sol.

[0087] The preparation method of the high-refraction isolation layer sol comprises the following steps: 10 g of tetraethyl titanate, 0.1 g of glacial acetic acid, 0.1 g of 8% mass fraction dilute hydrochloric acid solution, 100 g of ethanol and 5 g of water are stirred at 200 rpm for 3 h to obtain a sol solution, and the sol solution is aged for 3 d to obtain a high-refraction isolation layer sol.

[0088] A preparation method of a pure inorganic high-emission high-transmission anti-ultraviolet radiation refrigeration coating, comprising the following steps:

[0089] S1, coating a high-emission mixed sol on a glass substrate, curing at 400 DEG C for 3h to obtain a first layer film with a thickness of 400nm;

[0090] S2, coating a high-emission mixed sol on the surface of the first layer film, curing at 400 DEG C for 3h to obtain a second layer film with a thickness of 300nm;

[0091] S3, coating a high-refraction isolation layer sol on the surface of the second layer film, curing at 400 DEG C for 3h to obtain a third layer film with a thickness of 10nm;

[0092] S4, coating a high-emission mixed sol on the surface of the third layer film, curing at 400 DEG C for 3h to obtain a fourth layer film with a thickness of 300nm, and finally obtaining a pure inorganic high-emission high-transmission anti-ultraviolet radiation refrigeration coating comprising the first layer film, the second layer film, the third layer film and the fourth layer film in turn from bottom to top;

[0093] The infrared transmittance test diagram of the refrigeration coating prepared in Example 1 is shown in Figure 1 The reflectivity test diagram is shown in Figure 2

[0094] Example 2

[0095] The preparation method of the core-shell structure nanoparticle comprises the following steps: after 10g of tetraethyl orthosilicate, 30g of benzene propyl emulsion and 30g of water are blended, 1g of 8% mass fraction dilute hydrochloric acid solution is added, stirring is carried out at 500rpm for 3h, standing is carried out for 30h, and heat preservation is carried out at 400 DEG C for 1h to obtain the core-shell structure nanoparticle;

[0096] The preparation method of the binder comprises the following steps: after 10g of tetraethyl orthosilicate, 20g of methyl triethoxysilane, 80g of polyethylene glycol and 300g of anhydrous ethanol are blended, 1g of 8% mass fraction dilute hydrochloric acid solution is added, stirring is carried out at 500rpm for 18h to obtain a glue solution, the glue solution is aged for 3d to obtain the binder;

[0097] The preparation method of the yttrium-doped silicon dioxide particle comprises the following steps:

[0098] A1, 100g of tetraethyl orthosilicate and 300g of ethanol are stirred at 350rpm for 20min, 1g of yttrium chloride is added, stirring is carried out at 50 DEG C and 250rpm for 2h to obtain a precursor solution;

[0099] ​A2, 350 g of ethanol, 15 g of water and 100 g of cetyltrimethylammonium bromide are blended, and a 12% mass fraction of ammonia water solution is added to obtain a mixed solution with a pH of 9, the precursor solution is added dropwise into the mixed solution at a dropwise adding speed of 8 mL / min, stirring is carried out at 500 rpm for 2 h to obtain a suspension;

[0100] A3, the suspension is aged for 3 h, centrifuged, the precipitate is collected, dried, sintered at 800℃ for 1.5 h, cooled to room temperature, and pulverized to obtain yttrium-doped silicon dioxide particles with an average particle size of 160 nm;

[0101] The preparation method of the high-emission mixed sol includes the following steps: 3 g of core-shell structure nanoparticles, 2 g of yttrium-doped silicon dioxide particles and 20 g of binder are stirred at 250 rpm for 10 h, and aged for 3 d to obtain a high-emission mixed sol;

[0102] The preparation method of the high-refraction isolation layer sol includes the following steps: 10 g of tetraethyl titanate, 0.5 g of glacial acetic acid, 0.2 g of 8% mass fraction of dilute hydrochloric acid solution, 300 g of ethanol and 8 g of water are stirred at 250 rpm for 6 h to obtain a sol solution, and the sol solution is aged for 3 d to obtain a high-refraction isolation layer sol;

[0103] A preparation method of a pure inorganic high-emission high-transmission anti-ultraviolet radiation refrigeration coating, comprising the following steps:

[0104] S1, a high-emission mixed sol is coated on a glass substrate, and cured at 450℃ for 2 h to obtain a first layer film with a thickness of 500 nm;

[0105] S2, a high-emission mixed sol is coated on the surface of the first layer film, and cured at 450℃ for 2 h to obtain a second layer film with a thickness of 400 nm;

[0106] S3, a high-refraction isolation layer sol is coated on the surface of the second layer film, and cured at 450℃ for 2 h to obtain a third layer film with a thickness of 30 nm;

[0107] S4, a high-emission mixed sol is coated on the surface of the third layer film, and cured at 450℃ for 2 h to obtain a fourth layer film with a thickness of 400 nm, and finally a pure inorganic high-emission high-transmission anti-ultraviolet radiation refrigeration coating is obtained, which includes the first layer film, the second layer film, the third layer film and the fourth layer film from bottom to top.

[0108] Example 3

[0109] The preparation method of the core-shell structure nanoparticles comprises the following steps: 10 g of tetraethyl orthosilicate, 50 g of benzene propyl emulsion and 50 g of water are blended, then 1.5 g of 8% mass fraction dilute hydrochloric acid solution is added, stirring is carried out at 500 rpm for 3 h, standing is carried out for 30 h, and then heat preservation is carried out at 400℃ for 1 h to obtain the core-shell structure nanoparticles;

[0110] The preparation method of the binder comprises the following steps: 10 g of tetraethyl orthosilicate, 50 g of methyltrimethoxysilane, 100 g of cetyltrimethylammonium bromide and 600 g of anhydrous ethanol are blended, then 1.5 g of 8% mass fraction dilute hydrochloric acid solution is added, stirring is carried out at 500 rpm for 18 h to obtain a sol solution, and the sol solution is aged for 3 d to obtain the binder;

[0111] The preparation method of the yttrium-doped silicon dioxide particles comprises the following steps:

[0112] A1, 100 g of tetraethyl orthosilicate and 300 g of ethanol are stirred at 400 rpm for 15 min, 1 g of yttrium chloride is added, and stirring is carried out at 55℃ and 300 rpm for 1.5 h to obtain a precursor solution;

[0113] A2, 400 g of ethanol, 20 g of water and 150 g of cetyltrimethylammonium bromide are blended, and a 12% mass fraction ammonia water solution is added to obtain a mixed solution with a pH of 10, the precursor solution is added dropwise to the mixed solution at a dropwise adding speed of 8 mL / min, and stirring is carried out at 500 rpm for 2 h to obtain a suspension;

[0114] A3, the suspension is aged for 3 h, centrifuged, and the precipitate is collected, dried and sintered at 900℃ for 1 h, and then cooled to room temperature and crushed to obtain yttrium-doped silicon dioxide particles with an average particle size of 160 nm;

[0115] The preparation method of the high-emission mixed sol comprises the following steps: 3 g of the core-shell structure nanoparticles, 2 g of the yttrium-doped silicon dioxide particles and 15 g of the binder are stirred at 200 rpm for 12 h, and then aged for 3 d to obtain a high-emission mixed sol;

[0116] The preparation method of the high-refraction isolation layer sol comprises the following steps: 10 g of tetrabutyl titanate, 1 g of glacial acetic acid, 0.3 g of 8% mass fraction dilute hydrochloric acid solution, 500 g of ethanol and 10 g of water are stirred at 300 rpm for 1 h to obtain a sol solution, and the sol solution is aged for 3 d to obtain a high-refraction isolation layer sol;

[0117] A preparation method of a pure inorganic high-emission high-transmission anti-ultraviolet radiation refrigeration coating, comprising the following steps:

[0118] S1, the high-emission mixed sol is coated on a glass substrate to form a coating, and then heat treatment is carried out at 500℃ for 1 h to obtain a first layer film with a thickness of 600 nm;

[0119] S2, coating a high-emission mixed sol on the surface of the first layer of film, curing at 500℃ for 1h to obtain a second layer of film with a thickness of 500nm;

[0120] S3, coating a high-refraction isolation layer sol on the surface of the second layer of film, curing at 500℃ for 1h to obtain a third layer of film with a thickness of 60nm;

[0121] S4, coating a high-emission mixed sol on the surface of the third layer of film, curing at 500℃ for 1h to obtain a fourth layer of film with a thickness of 500nm, finally obtaining a pure inorganic high-emission high-transmission anti-ultraviolet radiation refrigeration coating layer comprising the first layer of film, the second layer of film, the third layer of film and the fourth layer of film in turn from bottom to top.

[0122] Example 4

[0123] The difference between this example and Example 2 is only that in the preparation method of yttrium-doped silica particles of this example, 7g of yttrium chloride is added.

[0124] Example 5

[0125] The difference between this example and Example 2 is only that in the preparation method of yttrium-doped silica particles of this example, 3g of yttrium chloride is added.

[0126] Example 6

[0127] The difference between this example and Example 2 is only that in the preparation method of yttrium-doped silica particles of this example, 5g of yttrium chloride is added.

[0128] Example 7

[0129] The difference between this example and Example 6 is only that the preparation method of the high-emission mixed sol is different, specifically:

[0130] 3g of core-shell structure nanoparticles, 2g of yttrium-doped silica particles, 0.5g of barium titanate with a specific surface area of 10~20m 2 / g, and 20g of a binder are stirred at 250rpm for 10h, aged for 3d to obtain a high-emission mixed sol.

[0131] Example 8

[0132] The difference between this example and Example 6 is only that the preparation method of the high-emission mixed sol is different, specifically:

[0133] 3g of core-shell structure nanoparticles, 2g of yttrium-doped silica particles, 0.5g of barium titanate with a specific surface area of 2~4m 2 / g of barium titanate and 20g of binder were stirred at 250rpm for 10h and aged for 3d to obtain a high-emission mixed sol.

[0134] Example 9

[0135] The only difference between this embodiment and Embodiment 6 is that the preparation method of the high-emission mixed sol is different in this embodiment, specifically:

[0136] 3g of core-shell structured nanoparticles, 2g of yttrium-doped silica particles, and 0.25g of [unclear - possibly a specific surface area] were combined. 2 / g of barium titanate, 0.25g of which has a specific surface area of ​​2~4m² 2 / g of barium titanate and 20g of binder were stirred at 250rpm for 10h and aged for 3d to obtain a high-emission mixed sol.

[0137] Example 10

[0138] The only difference between this embodiment and Embodiment 9 is that in the preparation method of the high-emission mixed sol in this embodiment, the added material has a specific surface area of ​​10~20m². 2 The amount of barium titanate added is 0.4g, and the specific surface area is 2~4m². 2 The amount of barium titanate is 0.1g.

[0139] Example 11

[0140] The only difference between this embodiment and Embodiment 9 is that in the preparation method of the high-emission mixed sol in this embodiment, the added material has a specific surface area of ​​10~20m². 2 The amount of barium titanate added is 0.375 g / g, and the specific surface area is 2~4 m². 2 The amount of barium titanate is 0.125g.

[0141] Example 12

[0142] The only difference between this embodiment and Embodiment 9 is that in the preparation method of the high-emission mixed sol in this embodiment, the added material has a specific surface area of ​​10~20m². 2 The amount of barium titanate added is 0.3g, and the specific surface area is 2~4m². 2 The amount of barium titanate is 0.2g.

[0143] Comparative Example 1

[0144] The only difference between this comparative example and Example 1 is that, in this comparative example, the yttrium-doped silicon dioxide particles are replaced with an equal amount of silicon dioxide particles.

[0145] Comparative Example 2

[0146] The only difference between this comparative example and Example 1 is that, in this comparative example, the yttrium-doped silicon dioxide particles are replaced with an equal amount of core-shell structured nanoparticles.

[0147] Comparative Example 3

[0148] The difference between the present comparative example and Example 1 is that, in the present comparative example, the core-shell structure nanoparticles are replaced by an equal amount of yttrium-doped silicon dioxide particles.

[0149] Comparative Example 4

[0150] The difference between the present comparative example and Example 1 is that, in the present comparative example, the preparation method of the pure inorganic high-emission high-transmittance anti-ultraviolet radiation refrigeration coating is different, specifically as follows:

[0151] S1, coating the high-emission mixed sol on the glass substrate to form a first layer of film, and curing at 400℃ for 3h to obtain a first layer of film with a thickness of 400nm;

[0152] S2, coating the high-emission mixed sol on the surface of the first layer of film to form a second layer of film, and curing at 400℃ for 3h to obtain a second layer of film with a thickness of 300nm;

[0153] S3, coating the high-emission mixed sol on the surface of the second layer of film to form a third layer of film, and curing at 400℃ for 3h to obtain a third layer of film with a thickness of 300nm, thereby obtaining a pure inorganic high-emission high-transmittance anti-ultraviolet radiation refrigeration coating comprising the first layer of film, the second layer of film and the third layer of film from bottom to top.

[0154] Comparative Example 5

[0155] The difference between the present comparative example and Example 1 is that, in the present comparative example, the preparation method of the pure inorganic high-emission high-transmittance anti-ultraviolet radiation refrigeration coating is different, specifically as follows:

[0156] S1, coating the high-emission mixed sol on the glass substrate to form a first layer of film, and curing at 400℃ for 3h to obtain a first layer of film with a thickness of 400nm;

[0157] S2, coating the high-refraction isolation layer sol on the surface of the first layer of film to form a second layer of film, and curing at 400℃ for 3h to obtain a second layer of film with a thickness of 10nm, thereby obtaining a pure inorganic high-emission high-transmittance anti-ultraviolet radiation refrigeration coating comprising the first layer of film and the second layer of film from bottom to top.

[0158] Experimental Example 1

[0159] The refrigeration coatings prepared in Examples 1-6, Example 9 and Comparative Examples 1-5 were tested for the following properties:

[0160] 1. The Fourier infrared spectrometer was used to test the radiation emissivity in the 8-13μm "atmospheric window";

[0161] 2. The refrigeration performance test: fill the stainless steel water tank with a size of 400mmx400mmx400mm with water, place the K-type thermocouple probe at the center position of the water tank (the K-type thermocouple probe needs to be calibrated before use), record the temperature data using a multi-channel data recorder, place the stainless steel water tank on a 10cm thick extruded board, attach the glass plate coated with the refrigeration coating to the outer surface of the water tank, seal the four sides, and attach the glass plate without the refrigeration coating to the outer surface of the water tank as a control group, wherein the initial temperature of the stainless steel water tank is 27℃, the average solar radiation is 750w / m 2 The water temperature in the stainless steel water tank corresponding to the refrigeration coating prepared by examples 1-6, example 9 and comparative examples 1-5, and the water temperature of the control group were tested, and the test results are shown in Table 1.

[0162] Table 1 Performance test results of examples 1-6, example 9 and comparative examples 1-5

[0163]

[0164] Compared with comparative examples 1-5, the radiation emissivity of the refrigeration coating prepared by examples 1-6 and example 9 in the 8-13μm "atmospheric window" is significantly improved, which indicates that when the high-emission mixed sol contains core-shell structure nanoparticles and yttrium-doped silicon dioxide particles, the use of core-shell structure nanoparticles and yttrium-doped silicon dioxide particles can effectively improve the emissivity of the film after the high-emission mixed sol is solidified, so that the refrigeration coating formed finally has good radiation emissivity in the 8-13μm "atmospheric window", thereby playing the refrigeration role of the coating. In addition, it can be seen from the refrigeration performance test results that compared with the control group and comparative examples 1-5, when the glass plate with the refrigeration coating prepared by examples 1-6 and example 9 is attached to the outside of the stainless steel water tank, it can have a certain refrigeration effect on the water in the water tank, and under certain solar radiation, the temperature drop can reach more than 5℃, which indicates that the refrigeration coating prepared by the present application has good refrigeration effect.

[0165] Experimental example 2

[0166] The refrigeration coating prepared by examples 6-12 was tested for corrosion resistance according to the acetic acid salt spray test method in GB / T 10125-2021 "Artificial atmosphere corrosion test Salt spray test", and the time when the refrigeration coating began to corrode was recorded, and the test results are shown in Table 2.

[0167] Table 2 Corrosion resistance test results of examples 6-12

[0168]

[0169] Compared with examples 6~8, the refrigeration coating prepared in examples 9~12 has a longer time to start to appear corrosion defects after acetic acid salt mist corrosion, indicating that when the high-emission mixed sol has barium titanate with a specific surface area of 10~20 m 2 / g and barium titanate with a specific surface area of 2~4 m 2 / g, the corrosion resistance of the refrigeration coating can be improved by using the two kinds of barium titanate with different specific surface areas together with the core-shell structure nanoparticles and yttrium-doped silica particles.

[0170] Experimental example 3

[0171] The refrigeration coating prepared in example 1 was subjected to infrared transmittance test by using an intelligent Fourier infrared spectrometer (EQUINOX55), and the infrared transmittance test graph is shown in Figure 1 The refrigeration coating prepared in example 1 was subjected to reflectance test by using an ultraviolet-visible-near infrared spectrophotometer (UV-3600i Plus) with a polytetrafluoroethylene integrating sphere accessory, and the test results are shown in Figure 2 .

[0172] As can be seen from Figure 1 , in the visible light range, the lowest transmittance of the refrigeration coating prepared in example 1 is 68.86%, and the highest transmittance is 95.15%, indicating that the refrigeration coating prepared in the present application has good visible light transmittance performance.

[0173] As can be seen from Figure 2 , in the vicinity of ultraviolet light (250~400 nm), it has good reflectivity, and the highest reflectivity can reach 58.00%, indicating that the refrigeration coating prepared in the present application has excellent ultraviolet radiation resistance and can reduce the absorption of solar radiation to a certain extent, thereby inhibiting the increase of the temperature of the coating itself, and thus laying a foundation for the refrigeration coating to have good refrigeration effect.

[0174] The above is only a preferred embodiment of the present application, and is not intended to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for the preparation of a pure inorganic high emissivity high transmission anti-UV radiation refrigerating coating, characterized in that, The method comprises the following steps: S1, coating a high-emission mixed sol on a glass substrate to form a first layer of film; S2, coating a high-emission mixed sol on the surface of the first layer of film to form a second layer of film; S3, coating a high-refraction isolation layer sol on the surface of the second layer of film to form a third layer of film; S4, coating a high-emission mixed sol on the surface of the third layer of film to form a fourth layer of film, and finally obtaining a pure inorganic high-emission high-transmission anti-ultraviolet radiation refrigeration coating layer comprising the first layer of film, the second layer of film, the third layer of film and the fourth layer of film from bottom to top; The raw materials of the high-emission mixed sol comprise core-shell structure nanoparticles, yttrium-doped silica particles and a binder; The preparation method of the binder comprises the following steps: blending tetraethyl orthosilicate, silane, a template agent and a solvent, adding an acidic catalyst, reacting to obtain a sol solution, and aging the sol solution to obtain the binder; The preparation method of the high-refraction isolation layer sol comprises the following steps: Mixing a titanium source, glacial acetic acid, an acidic catalyst and a solvent uniformly, reacting to obtain a sol solution, and aging the sol solution to obtain the high-refraction isolation layer sol; The core-shell structure nanoparticles are hollow structure and mesoporous structure silica nanoparticles generated by decomposition of a styrene-acrylic emulsion.

2. A process for the preparation of a pure inorganic high emissivity high transmittance anti-UV radiation coating for solar cooling according to claim 1, characterized in that, The preparation method of the yttrium-doped silica particles comprises the following steps: A1, blending tetraethyl orthosilicate and ethanol, adding a water-soluble yttrium salt, and mixing uniformly to obtain a precursor solution; A2, blending ethanol, an alkali solution, water and cetyltrimethylammonium bromide to obtain a mixed solution, adding the precursor solution into the mixed solution, and mixing uniformly to obtain a suspension; A3, aging the suspension, centrifuging, collecting the precipitate, drying the precipitate, sintering, and crushing to obtain the yttrium-doped silica particles.

3. A process for the preparation of a pure inorganic high emissivity high transmission anti-UV radiation refrigerating coating according to claim 2, characterized in that, The weight ratio of the tetraethyl orthosilicate to the water-soluble yttrium salt is 10:0.3-0.

5.

4. A process for the preparation of a pure inorganic high emissivity high transmittance anti-UV radiation coating for solar energy reflection according to claim 1, characterized in that, The preparation method of the core-shell structure nanoparticles comprises the following steps: blending tetraethyl orthosilicate, a styrene-acrylic emulsion and water, adding an acidic catalyst, reacting, standing, and heat preservation to obtain the core-shell structure nanoparticles; The weight ratio of the tetraethyl orthosilicate, the styrene-acrylic emulsion, the acidic catalyst and the water is 1:1-5:0.05-0.15:1-5.

5. A process for the preparation of a pure inorganic high emissivity high transmittance anti-UV radiation coating for solar energy reflection according to claim 1, characterized in that, In the preparation method of the binder, the weight ratio of the tetraethyl orthosilicate, the methyl trialkoxysilane, the solvent, the template agent and the acidic catalyst is 1:1-5:10-60:5-10:0.01-0.

15.

6. A process for the preparation of a pure inorganic high emissivity high transmission anti-UV radiation refrigerating coating according to claim 1, characterized in that, In steps S1, S2 and S4, the preparation method of the high-emission mixed sol independently comprises the following steps: Blending the core-shell structure nanoparticles, the yttrium-doped silica particles and the binder uniformly, and aging to obtain the high-emission mixed sol; The weight ratio of the core-shell structure nanoparticles, the yttrium-doped silica particles and the binder is 3:2:15-25.

7. A process for the preparation of a pure inorganic high emissivity high transmittance anti-UV radiation coating for solar energy reflection according to claim 1, characterized in that, The raw materials of the high-emission mixed sol further comprise barium titanate.

8. A process for the preparation of a pure inorganic high emissivity high transmission anti-UV radiation refrigerating coating according to claim 7, characterized in that, The barium titanate comprises barium titanate I and barium titanate II with a weight ratio of 3:1-2. The specific surface area of the barium titanate I is 10-20 m 2 / g, and the specific surface area of the barium titanate II is 2-4 m 2 / g.

9. A method of making a pure inorganic high emissivity high transmission anti-UV radiation refrigerating coating according to claim 1, characterized in that, The thickness of the first layer film is 400-600 nm; The thickness of the second layer film is 300-500 nm; The thickness of the third layer film is 10-60 nm; The thickness of the fourth layer film is 300-500 nm.

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