Reflection heat insulation and heat preservation double-effect integrated aerogel heat insulation finish paint and preparation method thereof

Abstract

The invention provides an aerogel heat insulation finishing coat integrating double effects of reflective heat insulation and heat preservation, and the aerogel heat insulation finishing coat integrates double effects of reflective heat insulation and heat preservation. Comprising the following components: modified acrylic resin, organic silicon coated titanium dioxide, organic silicon coated heavy calcium powder, near-infrared reflective heat-insulating titanium dioxide, silicon dioxide aerogel paste, an auxiliary agent and deionized water, wherein the modified acrylic resin is obtained by reacting styrene-acrylic emulsion, a light reflection polymer, an organic silicon hydrophobic additive and an ultraviolet light absorber; the light reflection polymer is titanium dioxide grafted acrylic acid. The problems that an existing product is lack of heat preservation performance, general in weather resistance and poor in stain resistance are solved, the comprehensive protection functions of reflective heat insulation, heat preservation, weather resistance and stain resistance are really achieved, and the application prospect is good.

Description

Technical Field

[0001] The invention relates to the technical field of coatings, and mainly to an aerogel thermal insulation topcoat with both reflective thermal insulation and heat preservation effects and a preparation method thereof. Background Art

[0002] With the rapid development of my country's construction industry and the increasingly prominent energy crisis, energy conservation and consumption reduction in buildings have become increasingly important. The energy consumption of heating and air conditioning in my country accounts for 55% of the total energy consumption of buildings, and is increasing at a rate of 1 percentage point per year. Therefore, researching and developing building insulation coatings to increase the temperature difference between indoor and outdoor, reduce cooling energy consumption in summer, and reduce heating energy consumption in winter has significant economic, environmental and social benefits.

[0003] According to different thermal insulation mechanisms, the earliest thermal insulation coatings on the market are divided into three categories: barrier thermal insulation coatings, reflective thermal insulation coatings and radiation thermal insulation coatings; then, composite thermal insulation coatings with multiple thermal insulation mechanisms and thermal insulation aggregates appeared. Although they are better than single thermal insulation coatings in terms of thermal insulation effect, they also have the following problems: when the amount of thermal insulation aggregates with different thermal insulation mechanisms is small, the filler is easy to form islands in the coating, and the heat will bypass these islands and transfer to the substrate, resulting in poor thermal insulation effect of the coating; when the amount of thermal insulation aggregates with different thermal insulation mechanisms is large, the thermal insulation aggregates will be unevenly distributed, affecting the thermal insulation effect, and will also cause the paint film to be unstable and have a short service life. In addition, this type of coating also generally has the disadvantages of long drying cycle, construction is easily affected by weather and environment, and the overall thermal insulation and reflection performance of the coating is not good. In particular, hollow ceramic microspheres have quality defects such as low closed porosity, high water absorption, and fragility during use, which seriously affect the thermal insulation effect of hollow ceramic microspheres and their products.

[0004] Among the existing products, reflective thermal insulation coatings have a single function, which is only reflective thermal insulation but not thermal insulation. They cannot solve the problem of winter insulation in areas with hot summers and cold winters. At the same time, the durability of the coating is poor, which greatly shortens the service life of the coating. It needs to be refurbished frequently to ensure that its reflective thermal insulation performance is not affected, which will undoubtedly increase the cost of investment. The exterior wall coating is easily contaminated, and the paint film has poor stain resistance. After contamination, the reflection of sunlight and near-infrared light is greatly reduced, affecting its reflective thermal insulation performance.

[0005] Therefore, there is an urgent need to develop a building thermal insulation coating that uses materials different from existing thermal insulation materials to solve the problems of poor stain resistance and weather resistance of existing thermal insulation coatings, and only reflective insulation but no thermal insulation effect. Summary of the invention

[0006] The present invention provides an aerogel thermal insulation topcoat with both reflective thermal insulation and heat preservation effects and a preparation method thereof, which can well solve the problems of existing products lacking in thermal insulation performance, general weather resistance and poor stain resistance, and truly achieves the comprehensive protective functions of reflective thermal insulation, heat preservation, weather resistance and stain resistance.

[0007] One object of the present invention is to provide an aerogel thermal insulation topcoat with both reflective thermal insulation and thermal insulation effects, wherein the aerogel thermal insulation topcoat with both reflective thermal insulation and thermal insulation effects comprises the following components in parts by mass:

[0008]

[0009] Wherein, the modified acrylic resin is obtained by reacting styrene acrylic emulsion, light reflective polymer, silicone hydrophobic additive and ultraviolet absorber;

[0010] The light-reflecting polymer is titanium dioxide grafted with acrylic acid.

[0011] Furthermore, the organosilicon hydrophobic auxiliary agent is selected from vinyltriethoxysilane.

[0012] Furthermore, the ultraviolet absorber is selected from 2-cyano-3,3-diphenylacrylate isooctyl ester.

[0013] Furthermore, the auxiliary agent is selected from one or more of an antifreeze agent, a wetting agent, a bactericide, a film-forming auxiliary agent, a thickener, and a defoaming agent.

[0014] Furthermore, the film-forming aid is an organic silicon film-forming aid.

[0015] Furthermore, the particle size of the near-infrared reflective heat-insulating titanium dioxide is 600-800nm.

[0016] Furthermore, the near-infrared reflective heat-insulating titanium dioxide is selected from Pannengtuo 550.

[0017] The structure of the near-infrared reflective heat-insulating titanium dioxide of the present invention includes a core, a shell layer, and an outer layer, wherein the core is a huge titanium dioxide treated by a sulfuric acid method, which has an optimal size for maximum sunlight and near-infrared reflection, can reflect sunlight to the greatest extent, and avoid the occurrence of temperature rise caused by excessive heat concentration; the shell layer is a dense silicon dioxide, which can not only reduce the loss and escape of free radicals, but also protect organic pigments and reduce the degradation of resins by weakening ultraviolet light in the system; the outer layer is an aluminum oxide coating layer, so that the titanium dioxide has excellent dispersibility, is evenly distributed in the system, and plays a stable role. When the addition amount in the formula system is 8-10%, it is used in medium chroma and light color (L>40), not only the coating system has a high sunlight reflectivity (its dilution power is about 50% of that of traditional titanium dioxide) and excellent reflective heat insulation performance, but also the existence of its own special structure can also play a synergistic role with the ultraviolet absorber in the modified acrylic resin, optimize the weather resistance of the system, and make the weather resistance of the coating system qualitatively improved.

[0018] The silica aerogel paste of the present invention has the following functions: a. It is coated in a copolymerized modified acrylic resin with a high cross-linking density, and interacts with the modified acrylic resin through intermolecular hydrogen bonds to form a highly hydrophobic surface, thereby improving the anti-fouling performance of the paint film; b. The ordered pore structure forms nearly "infinite thermal radiation reflection interfaces", effectively blocking thermal radiation and giving the system excellent thermal insulation performance; c. The special mesoporous structure has the characteristics of high specific surface area, large porosity, small pore size, and ordered pore structure. Its working principle is that the pore size is smaller than the free path (70nm) of gas molecule collision, and participates in heat transfer. Gas molecules cannot pass through, thereby essentially cutting off the heat conduction of gas molecules; due to the existence of infinite mesopores, heat flow can only be transmitted along the pore walls when transferring in the solid. The "infinite path" effect formed by the nearly infinite pore walls greatly reduces the heat conduction capacity of the solid; at the same time, the small pore size makes the air molecules lose the ability to flow freely and cannot participate in heat convection; the ordered pore structure forms nearly "infinite thermal radiation reflection interfaces", which effectively blocks thermal radiation, gives the system excellent thermal insulation properties, effectively maintains the stability of the indoor wall temperature, and saves energy consumption to a great extent.

[0019] Another object of the present invention is to provide a method for preparing the above-mentioned aerogel thermal insulation topcoat with both reflective heat insulation and thermal insulation effects, the method for preparing the aerogel thermal insulation topcoat with both reflective heat insulation and thermal insulation effects comprising the following steps:

[0020] S1, blending silicate and organosiloxane, adjusting the pH, adding ammonia water and aging, adding organosilicon for hydrophobic modification, purifying to obtain hydrophobic silica aerogel, adding dispersant to obtain the silica aerogel paste;

[0021] S2, adding titanium dioxide to an alkaline solution, heating to react, obtaining hydroxylated titanium dioxide, placing the hydroxylated titanium dioxide in acrylic acid, ultrasonicating and heating to react, obtaining titanium dioxide grafted acrylic acid, adding styrene acrylic emulsion, silicone hydrophobic additive, and ultraviolet absorber, heating and stirring, and reacting to obtain the modified acrylic resin;

[0022] S3, blending titanium dioxide, a film-forming aid, and an organosilicon surface treatment agent, purifying, and grinding to obtain the organosilicon-coated titanium dioxide;

[0023] S4, blending the heavy calcium powder, the film-forming aid, and the organosilicon surface treatment agent, purifying, and grinding to obtain the organosilicon-coated heavy calcium powder;

[0024] S5. According to the above mass fractions, the silica aerogel paste, modified acrylic resin, silicone-coated titanium dioxide, silicone-coated heavy calcium powder and other components are blended and stirred to obtain an aerogel insulation topcoat with both reflective insulation and thermal insulation effects.

[0025] Furthermore, in step S1, the mass ratio of the silicate, organosiloxane and organosilicon is (1-2):(2-4):(0.6-3).

[0026] Furthermore, in step S2, the mass ratio of the titanium dioxide grafted acrylic acid, styrene acrylic emulsion, silicone hydrophobic additive, and ultraviolet absorber is (3-5):(25-35):(0.5-3):(0.5-2).

[0027] Furthermore, in step S3, the mass ratio of the titanium dioxide, the film-forming aid, and the organosilicon surface treatment agent is (5-70):(1-8):(1-15).

[0028] Furthermore, in step S4, the mass ratio of the heavy calcium powder, the film-forming aid, and the silicone surface treatment agent is (5-70):(1-8):(1-15).

[0029] The present invention has the following beneficial effects:

[0030] The modified acrylic resin of the present invention is used as a base resin, which is polymerized by titanium dioxide grafted acrylic acid, styrene acrylic emulsion, silicone hydrophobic auxiliary agent, and ultraviolet absorber. Groups such as silicone, reflective polymer, and ultraviolet absorber are introduced, thereby increasing the affinity for silicone-coated titanium dioxide and heavy calcium powder, and being able to more effectively adsorb and combine the above-mentioned inorganic components. Moreover, the introduction of titanium dioxide grafted acrylic acid as a light-reflecting polymer and ultraviolet absorber group enhances the reflective effect of the coating on sunlight. In addition, the silicone hydrophobic auxiliary agent gives the coating more excellent hydrophobicity, weather resistance, and scrub resistance.

[0031] The present invention also performs an organic silicon coating treatment on titanium dioxide and heavy calcium powder, thereby improving the compatibility between components in the coating with a high inorganic filler content, avoiding the phenomenon of agglomeration and uneven dispersion of reflective and heat-insulating fillers, and being able to further combine with resins containing organic silicon groups, adsorb and cross-link through intermolecular forces, and the organic silicon coating also improves the hydrophobic effect of the product, and enhances the stability of the coating and other properties. In addition, the present invention also uses an organic silicon film-forming aid as a component, which can be combined with organic silicon coated titanium dioxide, organic silicon coated heavy calcium powder and modified acrylic resin to form a synergistic effect, improve the film-forming effect of the coating, and thereby enhance the weather resistance, stability, strength and other properties of the product.

[0032] The aerogel thermal insulation topcoat with both reflective heat insulation and thermal insulation prepared by the present invention has no abnormality in the 1500h xenon lamp aging test of the paint film, and the weather resistance performance ΔE*≤0.5, and has excellent weather resistance; secondly, according to the GB / T 9755-2014 standard test, the stain resistance performance can reach within 10%, which is far higher than the standard requirement of 15%, and has good stain resistance; and, compared with the widely circulated reflective thermal insulation topcoat on the market, the technical solution has both reflective heat insulation performance and thermal insulation function, providing a more powerful "stability maintenance coat" for the interior and exterior of the building, effectively saving energy consumption, and achieving the purpose of energy saving and emission reduction. DETAILED DESCRIPTION

[0033] In order to more clearly illustrate the technical solution of the present invention, the following examples are listed. Unless otherwise stated, the raw materials, reactions and post-treatment methods shown in the examples are common raw materials on the market and technical methods well known to those skilled in the art.

[0034] The words "preferred", "preferably", "more preferably", etc. in the present invention refer to embodiments of the present invention that can provide certain beneficial effects in certain circumstances. However, other embodiments may also be preferred under the same circumstances or other circumstances. In addition, the description of one or more preferred embodiments does not imply that other embodiments are not applicable, nor is it intended to exclude other embodiments from the scope of the present invention.

[0035] It should be understood that, except in any operating examples, or where otherwise indicated, all numbers indicating, for example, the amounts of ingredients used in the specification and claims should be understood to be modified in all cases by the term "about". Therefore, unless indicated to the contrary, the numerical parameters set forth in the following specification and the appended claims are approximate values ​​that vary depending on the desired properties to be obtained by the present invention.

[0036] The following raw materials are used in the embodiments of the present invention:

[0037] 550, near-infrared reflective heat-insulating titanium dioxide, purchased from Shanghai Aorun Chemical Co., Ltd.;

[0038] MBS5050, preservative, purchased from Thor Chemical Group;

[0039] Propylene glycol, antifreeze, was purchased from Shanghai Shengyue International Trading Co., Ltd.;

[0040] HTK-5040, sodium salt dispersant, purchased from Shanghai Hongtu Industrial Co., Ltd.;

[0041] Hexadecyltrimethylammonium bromide, ammonium salt dispersant, purchased from Kangdisi Chemical (Hubei) Co., Ltd.;

[0042] RS-998A, styrene acrylic emulsion, purchased from Badfu Group Co., Ltd.;

[0043] PMX-200, silicone film-forming agent, purchased from Dow Corning Co.;

[0044] 2410AC, defoamer, purchased from BASF Chemical Company;

[0045] Titanium dioxide, particle size 0.2-0.3μm;

[0046] Heavy calcium powder, particle size 10-20μm;

[0047] RM-8W, thickener, purchased from The Dow Chemical Company.

[0048] Example 1

[0049] An aerogel thermal insulation topcoat with both reflective thermal insulation and heat preservation effects, comprising the following components in parts by mass:

[0050]

[0051] The preparation method of the aerogel thermal insulation topcoat with both reflective thermal insulation and thermal insulation effects comprises the following steps:

[0052] S1. 20.8 g of tetraethyl orthosilicate, 40.8 g of methyltrimethoxysilane, 23 g of anhydrous ethanol and 126 g of water were mixed and stirred, 10 ml of hydrochloric acid was added and stirred for 1 h to adjust the pH, 20 ml of ammonia water and 2 ml of N,N-dimethylformamide were added, stirred for 10 min, and the mixture was allowed to stand for 2 h to form a wet gel, which was then placed in a vacuum drying oven for aging. After aging, the wet gel was added to an ethanol solution of 100 g of hexamethyldisilazane (the mass ratio of hexamethyldisilazane to ethanol was 1:4), and the mixture was soaked for 24 h for hydrophobic modification. The solution was replaced with n-hexane for 24 h, and the solution replacement was repeated 3 times. The wet gel was placed in a drying oven at 50 ° C and dried at normal pressure to obtain a hydrophobic silica aerogel. The hydrophobic silica aerogel, HTK-5040, hexadecyltrimethylammonium bromide and deionized water were mixed and stirred in a mass ratio of 30:1:3:150 to obtain the silica aerogel paste.

[0053] S2, adding 5 g of titanium dioxide into 40 ml of potassium hydroxide aqueous solution with a pH value of 13 and stirring, heating to 200° C. to react for 30 h, filtering, washing, and drying at 60° C. to obtain hydroxylated titanium dioxide;

[0054] Blend hydroxylated titanium dioxide and acrylic acid at a molar ratio of 1:5, add a catalyst 4-dimethylaminopyridine (the amount of 4-dimethylaminopyridine is 1% of the total mass of hydroxylated titanium dioxide and acrylic acid), ultrasonicate and heat to 80°C for 4 hours, filter and dry to obtain titanium dioxide grafted with acrylic acid;

[0055] RS-998A, titanium dioxide grafted acrylic acid, vinyl triethoxysilane, 2-cyano-3,3-diphenylacrylate, and BPO were mixed in a mass ratio of 29:3:3:0.5:0.3 using water as solvent, and heated to 80° C. under a nitrogen atmosphere and stirred for reaction for 3 hours to obtain the modified acrylic resin.

[0056] S3. Blend 3 g of ethylene carbonate and 100 g of deionized water, stir to obtain a solution, add 30 g of titanium dioxide and stir, add 100 ml of a 3 wt% aqueous solution of sodium methyl silicate, stir for 3 h, filter with suction, put into an oven to dry at 50° C. for 1 h and at 100° C. for 5 h, grind and crush to obtain the organosilicon-coated titanium dioxide.

[0057] S4. Blend 3g of ethylene carbonate and 100g of deionized water, stir to obtain a solution, add 30g of heavy calcium powder and stir, add 100ml of 3wt% sodium methyl silicate aqueous solution, stir for 3h, filter, put into an oven to dry at 50°C for 1h and at 100°C for 5h, grind and crush to obtain the silicone-coated heavy calcium powder.

[0058] S5. Add 19 parts of deionized water into the dispersion kettle according to the above mass fractions, adjust the speed of the dispersion machine to 1000r / min, and add 550, silicone-coated titanium dioxide, silicone-coated heavy calcium powder, and silica aerogel paste are dispersed for 15 minutes, the speed is reduced to 600r / min, 0.1 parts of MBS5050, 0.3 parts of propylene glycol, modified acrylic resin, 1.2 parts of PMX-200 and 0.5 parts of 2410AC are added in sequence, and stirring is continued for 5 minutes; 0.5 parts of RM-8W and 5 parts of deionized water are added, and stirring is performed to obtain an aerogel insulating topcoat with both reflective insulation and thermal insulation effects.

[0059] Example 2

[0060] An aerogel thermal insulation topcoat with both reflective thermal insulation and heat preservation effects, comprising the following components in parts by mass:

[0061]

[0062] The preparation method of the aerogel thermal insulation topcoat with both reflective thermal insulation and thermal insulation effects comprises the following steps:

[0063] S1. 20.8 g of tetraethyl orthosilicate, 40.8 g of methyltrimethoxysilane, 23 g of anhydrous ethanol and 126 g of water were mixed and stirred, 10 ml of hydrochloric acid was added and stirred for 1 h to adjust the pH, 20 ml of ammonia water and 2 ml of N,N-dimethylformamide were added, stirred for 10 min, and the mixture was allowed to stand for 2 h to form a wet gel, which was then placed in a vacuum drying oven for aging. After aging, the wet gel was added to an ethanol solution of 100 g of hexamethyldisilazane (the mass ratio of hexamethyldisilazane to ethanol was 1:4), and the mixture was soaked for 24 h for hydrophobic modification. The solution was replaced with n-hexane for 24 h, and the solution replacement was repeated 3 times. The wet gel was placed in a drying oven at 50 ° C and dried at normal pressure to obtain a hydrophobic silica aerogel. The hydrophobic silica aerogel, HTK-5040, hexadecyltrimethylammonium bromide and deionized water were mixed and stirred in a mass ratio of 30:1:3:150 to obtain the silica aerogel paste.

[0064] S2, adding 5 g of titanium dioxide into 40 ml of potassium hydroxide aqueous solution with a pH value of 13 and stirring, heating to 200° C. to react for 30 h, filtering, washing, and drying at 60° C. to obtain hydroxylated titanium dioxide;

[0065] Blend hydroxylated titanium dioxide and acrylic acid at a molar ratio of 1:5, add a catalyst 4-dimethylaminopyridine (the amount of 4-dimethylaminopyridine is 1% of the total mass of hydroxylated titanium dioxide and acrylic acid), ultrasonicate and heat to 80°C for 4 hours, filter and dry to obtain titanium dioxide grafted with acrylic acid;

[0066] RS-998A, titanium dioxide grafted acrylic acid, vinyl triethoxysilane, 2-cyano-3,3-diphenylacrylate, and BPO were mixed in a mass ratio of 29:3:3:0.5:0.3 using water as solvent, and heated to 80° C. under a nitrogen atmosphere and stirred for reaction for 3 hours to obtain the modified acrylic resin.

[0067] S3. Blend 3 g of ethylene carbonate and 100 g of deionized water, stir to obtain a solution, add 30 g of titanium dioxide and stir, add 100 ml of a 3 wt% aqueous solution of sodium methyl silicate, stir for 3 h, filter with suction, put into an oven to dry at 50° C. for 1 h and at 100° C. for 5 h, grind and crush to obtain the organosilicon-coated titanium dioxide.

[0068] S4. Blend 3g of ethylene carbonate and 100g of deionized water, stir to obtain a solution, add 30g of heavy calcium powder and stir, add 100ml of 3wt% sodium methyl silicate aqueous solution, stir for 3h, filter, put into an oven to dry at 50°C for 1h and at 100°C for 5h, grind and crush to obtain the silicone-coated heavy calcium powder.

[0069] S5. Add 20 parts of deionized water into the dispersion kettle according to the above mass fractions, adjust the speed of the disperser to 1200r / min, and add 550, silicone-coated titanium dioxide, silicone-coated heavy calcium powder, and silica aerogel paste were dispersed for 17 minutes, the speed was reduced to 700r / min, 0.2 parts of MBS5050, 0.4 parts of propylene glycol, modified acrylic resin, 1.3 parts of PMX-200 and 0.6 parts of 2410AC were added in sequence, and stirring was continued for 6 minutes; 0.6 parts of RM-8W and 8 parts of deionized water were added, and stirring was performed to obtain an aerogel insulation topcoat with both reflective insulation and thermal insulation effects.

[0070] Example 3

[0071] An aerogel thermal insulation topcoat with both reflective thermal insulation and heat preservation effects, comprising the following components in parts by mass:

[0072]

[0073] The preparation method of the aerogel thermal insulation topcoat with both reflective thermal insulation and thermal insulation effects comprises the following steps:

[0074] S1. 20.8 g of tetraethyl orthosilicate, 40.8 g of methyltrimethoxysilane, 23 g of anhydrous ethanol and 126 g of water were mixed and stirred, 10 ml of hydrochloric acid was added and stirred for 1 h to adjust the pH, 20 ml of ammonia water and 2 ml of N,N-dimethylformamide were added, stirred for 10 min, and the mixture was allowed to stand for 2 h to form a wet gel, which was then placed in a vacuum drying oven for aging. After aging, the wet gel was added to an ethanol solution of 100 g of hexamethyldisilazane (the mass ratio of hexamethyldisilazane to ethanol was 1:4), and the mixture was soaked for 24 h for hydrophobic modification. The solution was replaced with n-hexane for 24 h, and the solution replacement was repeated 3 times. The wet gel was placed in a drying oven at 50 ° C and dried at normal pressure to obtain a hydrophobic silica aerogel. The hydrophobic silica aerogel, HTK-5040, hexadecyltrimethylammonium bromide and deionized water were mixed and stirred in a mass ratio of 30:1:3:150 to obtain the silica aerogel paste.

[0075] S2, adding 5 g of titanium dioxide into 40 ml of potassium hydroxide aqueous solution with a pH value of 13 and stirring, heating to 200° C. to react for 30 h, filtering, washing, and drying at 60° C. to obtain hydroxylated titanium dioxide;

[0076] Blend hydroxylated titanium dioxide and acrylic acid at a molar ratio of 1:5, add a catalyst 4-dimethylaminopyridine (the amount of 4-dimethylaminopyridine is 1% of the total mass of hydroxylated titanium dioxide and acrylic acid), ultrasonicate and heat to 80°C for 4 hours, filter and dry to obtain titanium dioxide grafted with acrylic acid;

[0077] RS-998A, titanium dioxide grafted acrylic acid, vinyl triethoxysilane, 2-cyano-3,3-diphenylacrylate, and BPO were mixed in a mass ratio of 29:3:3:0.5:0.3 using water as solvent, and heated to 80° C. under a nitrogen atmosphere and stirred for reaction for 3 hours to obtain the modified acrylic resin.

[0078] S3. Blend 3 g of ethylene carbonate and 100 g of deionized water, stir to obtain a solution, add 30 g of titanium dioxide and stir, add 100 ml of a 3 wt% aqueous solution of sodium methyl silicate, stir for 3 h, filter with suction, put into an oven to dry at 50° C. for 1 h and at 100° C. for 5 h, grind and crush to obtain the organosilicon-coated titanium dioxide.

[0079] S4. Blend 3g of ethylene carbonate and 100g of deionized water, stir to obtain a solution, add 30g of heavy calcium powder and stir, add 100ml of 3wt% sodium methyl silicate aqueous solution, stir for 3h, filter, put into an oven to dry at 50°C for 1h and at 100°C for 5h, grind and crush to obtain the silicone-coated heavy calcium powder.

[0080] S5. Add 21 parts of deionized water into the dispersion kettle according to the above mass fractions, adjust the speed of the disperser to 1500r / min, and add 550, silicone-coated titanium dioxide, silicone-coated heavy calcium powder, and silica aerogel paste are dispersed for 20 minutes, the rotation speed is reduced to 800r / min, 0.3 parts of MBS5050, 0.5 parts of propylene glycol, modified acrylic resin, 1.4 parts of PMX-200 and 0.7 parts of 2410AC are added in sequence, and stirring is continued for 7 minutes; 0.7 parts of RM-8W and 10 parts of deionized water are added, and stirring is performed to obtain an aerogel insulating topcoat with both reflective insulation and thermal insulation effects.

[0081] Comparative Example 1

[0082] The difference between Comparative Example 1 and Example 1 is that step S2 is replaced by: RS-998A, titanium dioxide grafted acrylic acid, and 2-cyano-3,3-diphenylacrylate are blended in a mass ratio of 29:3:0.5 to obtain the modified acrylic resin.

[0083] Comparative Example 2

[0084] The difference between Comparative Example 2 and Example 1 is that the silicone-coated titanium dioxide, silicone-coated heavy calcium powder and other qualities are replaced by unmodified titanium dioxide and unmodified heavy calcium powder.

[0085] Comparative Example 3

[0086] The difference between Comparative Example 3 and Example 1 is that the mass of the organosilicon film-forming aid is replaced by alcohol ester twelve.

[0087] Test Case

[0088] The paint films of Examples 1-3 and Comparative Examples 1-3 were tested for water permeability, scrub resistance, stain resistance, solar reflectance, near-infrared reflectance, hemispherical emissivity, aging resistance, and reflective heat insulation performance.

[0089] Test Method

[0090] According to the provisions of Appendix B of the national standard "GB / T 9755-2014 Synthetic Resin Exterior Wall Emulsion", the water permeability of the paint film is tested. According to the provisions of Appendix C of the national standard "GB / T 9755-2014 Synthetic Resin Exterior Wall Emulsion", the washability of the paint film is tested. According to the provisions of 5.17 of the national standard "GB / T 9755-2014 Synthetic Resin Exterior Wall Emulsion", the stain resistance of the paint film is tested. According to the provisions of Appendix A of the standard "JG / T 235-2014 Building Reflective Insulation Paint", the solar reflectance of the paint film is tested. According to the provisions of Appendix B of the standard "JG / T 235-2014 Building Reflective Insulation Paint", the near-infrared reflectance of the paint film is tested. According to the provisions of Appendix C of the standard "JG / T 235-2014 Building Reflective Insulation Paint", the hemispherical emissivity of the paint film is tested. According to the provisions of Appendix C of the national standard "GB / T According to the provisions of 5.16 of "9755-2014 Synthetic Resin Exterior Wall Emulsion", the aging resistance of the paint film is tested. According to the provisions of the national standard "JGT235-2008 Building Reflective Insulation Paint", the reflective thermal insulation performance of the paint film is tested by detecting the temperature difference between the blank sample and the test sample on the side facing away from the heat source.

[0091] Among them, the smaller the water permeability value, the better the waterproof performance of the paint film; the more times the wash resistance is, the better the wash resistance of the paint film; the smaller the stain resistance value, the better the stain resistance of the paint film; the higher the solar reflectance, near-infrared reflectance, and hemispherical emissivity, the better the reflective heat insulation performance of the paint film; the ΔE* in the aging resistance performance indicates the color difference value before and after aging, ΔE*≤1.5 indicates no discoloration, 1.6≤ΔE*≤3 indicates very slight discoloration, and the larger the ΔE*, the more serious the discoloration.

[0092] Table 1 shows the results of the tests.

[0093] Table 1 Performance test results of Examples 1-3 and Comparative Examples 1-3

[0094]

[0095]

[0096] It can be seen from Table 1 that the various properties of Examples 1-3 are better than those of Comparative Examples 1-3 and market products.

[0097] The various properties of Examples 1-3 are better than those of Comparative Example 1 because the titanium dioxide grafted acrylic acid, styrene acrylic emulsion, and ultraviolet absorber in Comparative Example 1 are only physically blended, and no silicone hydrophobic additive is added, so that the obtained modified acrylic resin has poor compatibility with the remaining inorganic components and is difficult to disperse evenly, thereby reducing the performance.

[0098] The various properties of Examples 1-3 are better than those of Comparative Example 2 because the titanium dioxide and heavy calcium powder are not modified in Comparative Example 2, which reduces the compatibility of the high-content inorganic components with the remaining components, makes them unable to crosslink with the organic components, and makes them more easily agglomerated, thereby reducing the performance.

[0099] The various properties of Examples 1-3 are slightly better than those of Comparative Example 3. The reason is that in Comparative Example 3, the organosilicon film-forming aid is replaced by alcohol ester twelve. The compatibility of alcohol ester twelve with the high content of organosilicon groups in the component is not as good as that of the organosilicon film-forming aid. Therefore, alcohol ester twelve is not easy to disperse evenly, the film-forming effect becomes worse, and ultimately has an adverse effect on product performance.

[0100] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0101] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. An aerogel thermal insulation topcoat with both reflective insulation and thermal insulation, characterized in that: The aerogel thermal insulation topcoat with both reflective thermal insulation and thermal insulation effects comprises the following components in parts by mass: Wherein, the modified acrylic resin is obtained by reacting styrene acrylic emulsion, light reflective polymer, silicone hydrophobic additive and ultraviolet absorber; The light-reflecting polymer is titanium dioxide grafted with acrylic acid.

2. According to claim 1, the aerogel thermal insulation topcoat with both reflective thermal insulation and thermal insulation is characterized in that: The organosilicon hydrophobic auxiliary agent is selected from vinyl triethoxy silane.

3. According to claim 1, the aerogel thermal insulation topcoat with both reflective insulation and thermal insulation is characterized in that: The ultraviolet absorber is selected from 2-cyano-3,3-diphenylacrylate isooctyl ester.

4. According to claim 1, the aerogel thermal insulation topcoat with both reflective insulation and thermal insulation is characterized in that: The auxiliary agent is selected from one or more of antifreeze agents, wetting agents, bactericides, film-forming aids, thickeners, and defoaming agents.

5. The aerogel thermal insulation topcoat with both reflective insulation and thermal insulation as claimed in claim 1, characterized in that: The film-forming aid is an organic silicon film-forming aid.

6. The method for preparing the aerogel thermal insulation topcoat with both reflective thermal insulation and thermal insulation as claimed in any one of claims 1 to 5, characterized in that: The preparation method of the aerogel thermal insulation topcoat with both reflective thermal insulation and thermal insulation effects comprises the following steps: S1, blending silicate and organosiloxane, adjusting the pH, adding ammonia water and aging, adding organosilicon for hydrophobic modification, purifying to obtain hydrophobic silica aerogel, adding dispersant to obtain the silica aerogel paste; S2, adding titanium dioxide to an alkaline solution, heating to react, obtaining hydroxylated titanium dioxide, placing the hydroxylated titanium dioxide in acrylic acid, ultrasonicating and heating to react, obtaining titanium dioxide grafted acrylic acid, adding styrene acrylic emulsion, silicone hydrophobic additive, and ultraviolet absorber, heating and stirring, and reacting to obtain the modified acrylic resin; S3, blending titanium dioxide, a film-forming aid, and an organosilicon surface treatment agent, purifying, and grinding to obtain the organosilicon-coated titanium dioxide; S4, blending the heavy calcium powder, the film-forming aid, and the organosilicon surface treatment agent, purifying, and grinding to obtain the organosilicon-coated heavy calcium powder; S5. According to the above mass fractions, the silica aerogel paste, modified acrylic resin, silicone-coated titanium dioxide, silicone-coated heavy calcium powder and other components are blended and stirred to obtain an aerogel insulation topcoat with both reflective insulation and thermal insulation effects.

7. The method for preparing the aerogel thermal insulation topcoat with both reflective heat insulation and thermal insulation according to claim 6, characterized in that: In step S1, the mass ratio of the silicate, organosiloxane and organosilicon is (1-2):(2-4):(0.6-3).

8. The method for preparing the aerogel thermal insulation topcoat with both reflective heat insulation and thermal insulation according to claim 6, characterized in that: In step S2, the mass ratio of titanium dioxide grafted acrylic acid, styrene acrylic emulsion, silicone hydrophobic additive, and ultraviolet absorber is (3-5):(25-35):(0.5-3):(0.5-2).

9. The method for preparing the aerogel thermal insulation topcoat with both reflective heat insulation and thermal insulation according to claim 6, characterized in that: In step S3, the mass ratio of the titanium dioxide, the film-forming aid, and the organosilicon surface treatment agent is (5-70):(1-8):(1-15).

10. The method for preparing the aerogel thermal insulation topcoat with both reflective heat insulation and thermal insulation according to claim 6, characterized in that: In step S4, the mass ratio of the heavy calcium powder, the film-forming aid, and the silicone surface treatment agent is (5-70):(1-8):(1-15).

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