Waterproof coating with reflective heat insulation performance and application thereof

Abstract

The invention discloses a waterproof coating with reflective heat insulation performance and application thereof, the waterproof coating comprises 35-60% of a waterborne polyurethane dispersion, 10-13% of a light reflecting agent, 5-15% of heat insulation microbeads, 3-10% of nano aerogel adhesive cement, 5-10% of water, 5-10% of filler and 0.5-10% of other functional additives based on the total weight of the waterproof coating; wherein the heat insulation microbeads comprise glass hollow microbeads, ceramic hollow microbeads and mineral wool. The waterproof coating has excellent heat insulation performance, weather resistance, bonding performance and waterproof performance.

Description

Technical Field

[0001] The invention relates to the field of waterproof coatings, in particular to a waterproof coating with reflective heat insulation performance and a use thereof. Background Art

[0002] Waterproofing the exposed surface of buildings has always been a focus of attention, especially in areas with heavy rainfall. At present, in the field of civil waterproofing, traditional acrylic waterproof coatings are mostly used, and most of them are renovated every 3 or 5 years. Therefore, there is a great demand for waterproof coatings that can be exposed and have reflective and heat-insulating functions.

[0003] Ordinary reflective heat-insulating waterproof coatings are usually composed of heat-insulating primer, heat-insulating mid-coat and heat-insulating topcoat. The heat-insulating primer usually plays a connecting role, improves the adaptability of the base layer, and improves the bonding effect between the heat-insulating mid-coat and the base layer. The heat-insulating mid-coat is characterized by low density and light weight, and mainly prevents heat conduction. It has a low thermal conductivity but poor reflection effect on sunlight. The main function of the heat-insulating topcoat is to have good reflection function. The reflective heat-insulating product system is complex and has many construction processes, which still needs further improvement. Summary of the invention

[0004] In view of this, the present invention proposes a waterproof coating with reflective heat insulation performance and its use. The waterproof coating can be directly exposed for use and has excellent heat insulation performance, weather resistance, bonding performance and waterproof performance.

[0005] The invention provides a waterproof coating comprising 35-60% of an aqueous polyurethane dispersion, 10-13% of a light reflector, 5-15% of heat-insulating microspheres, 3-10% of a nano-aerogel mortar, 5-10% of water, 5-10% of a filler, and 0.5-10% of other functional additives, based on the total weight of the waterproof coating; wherein the heat-insulating microspheres comprise hollow glass microspheres, hollow ceramic microspheres and mineral wool.

[0006] The present invention provides the following non-conventional alternatives:

[0007] The light reflector includes one or more of titanium dioxide, aluminum silver paste, and sericite powder.

[0008] The titanium dioxide is a mixture of rutile titanium dioxide and near-infrared reflecting titanium dioxide.

[0009] The weight ratio of the rutile titanium dioxide to the near-infrared reflecting titanium dioxide is (0.5-1.0):1.

[0010] The light reflector is a light reflective composition comprising titanium dioxide and aluminum silver paste in a weight ratio of (8-10):1.

[0011] The weight ratio of the glass hollow microspheres, the ceramic hollow microspheres and the mineral wool is 1:(0.5-1):(0.5-1).

[0012] The nano-aerogel mortar is a mortar of polyurethane-modified silica aerogel, which is prepared from a mortar composition comprising an aqueous polyurethane dispersion for aerogel, nano-aerosilicic acid, water, and optionally other liquid additives.

[0013] The wet density of the nano aerogel slurry is 0.3-0.9 g / cm 3 ; Dry film thermal conductivity is 0.010-0.080W / (m·K); Dry film density is 100-3000kg / m 3 .

[0014] The other functional additives include one or more of bactericidal preservatives, wetting and dispersing agents, defoaming agents, silane coupling agents, film-forming aids, and mildew inhibitors.

[0015] The present invention also provides the use of the waterproof coating as described above in preparing a waterproof coating film with heat insulation performance for the exterior wall or roof of a building.

[0016] According to the technical solution of the present invention, the waterproof coating comprises various components such as waterborne polyurethane dispersion, light reflector, heat-insulating microbeads, nano-aerogel and the like in a specific ratio, so that the waterproof coating has good waterproof effect, low thermal conductivity, excellent reflective heat-insulating performance and weather resistance. Specifically, the light reflector effectively improves the light reflection ability of the waterproof coating; the heat-insulating microbeads and nano-aerogel significantly improve the heat-insulating ability of the waterproof coating; the waterborne polyurethane dispersion effectively enhances the compactness of the coating film formed by the waterproof coating, thereby improving the waterproof performance. DETAILED DESCRIPTION

[0017] For ease of understanding of the present invention, the present invention will be described more fully below with reference to examples. Preferred embodiments of the present invention are provided in the examples. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0018] Compared with traditional reflective heat-insulating waterproof coatings, the waterproof coating of the present invention is a single-component water-based coating that can be used right out of the bucket; it has excellent solar reflectance, low thermal conductivity, and a thermal insulation temperature difference of 20°C or above, with excellent thermal insulation effect; after film formation, it has high elasticity, good impermeability, and excellent waterproof effect; it has excellent weather resistance; it has high bonding strength and excellent stain resistance.

[0019] In an embodiment of the present invention, the waterproof coating comprises 35-60% of aqueous polyurethane dispersion, 10-13% of light reflector, 5-15% of heat-insulating microspheres, 3-10% of nano-aerogel glue, 5-10% of water, 5-10% of filler, and 0.5-10% of other functional additives, based on the total weight of the waterproof coating; wherein the heat-insulating microspheres include hollow glass microspheres, hollow ceramic microspheres and mineral wool. In the waterproof coating, the sum of the weight percentages of the components is 100%, based on the total weight of the waterproof coating.

[0020] The waterproof coating includes 35-60%, for example 48-60%, of an aqueous polyurethane dispersion, based on the total weight of the waterproof coating. The aqueous polyurethane dispersion contains at least one of anionic aromatic polyether polyurethane dispersion and anionic aliphatic polyether polyurethane dispersion and anionic aliphatic polycarbonate-polyether polyurethane dispersion. The solid content of the aqueous polyurethane dispersion is 48%-55%; as the most basic film-forming substance of the waterproof coating, it has the characteristics of being soft and non-brittle at low temperatures and non-sticky at high temperatures, and has excellent low-temperature bending resistance and high-temperature resistance; it makes the coating film denser, the polyurethane has good elasticity, strong powder encapsulation, excellent adhesion and stain resistance; the aqueous polyurethane dispersion can effectively resist the photo-oxidative degradation of the waterproof coating by ultraviolet rays, so it has good durability and water resistance. The aqueous polyurethane dispersion can usually be purchased from Wanhua Chemical. 3459 waterborne polyurethane dispersion, 3455 waterborne polyurethane dispersion, At least one of 8355 waterborne polyurethane dispersions.

[0021] The waterproof coating comprises 10-13%, for example 11-13%, of a light reflector, based on the total weight of the waterproof coating, and the light reflector comprises one or more of titanium dioxide, aluminum silver paste, and sericite powder.

[0022] Titanium dioxide can be rutile titanium dioxide or near-infrared reflecting titanium dioxide, such as a mixture of rutile titanium dioxide and near-infrared reflecting titanium dioxide. The energy radiated from sunlight to the ground consists of three parts: ultraviolet light, visible light, and near-infrared light. The wavelength of ultraviolet light is less than 400nm, accounting for about 5% of the total energy of the sun. The wavelength of visible light is 400-720nm, accounting for about 45% of the total energy of the sun. The wavelength of near-infrared light is 720-2500nm, accounting for about 50% of the total energy of the sun. It can be seen that solar energy is mainly concentrated in the visible light region and the near-infrared light region. Among them, the near-infrared wavelength is the main part of heat generation and has a strong thermal effect. Rutile titanium dioxide has a high refractive index and good covering power in the visible light region. Its reflectivity is ≥80%, which can play a role in photothermal reflection, and it has good covering rate and tinting power, and is relatively stable in the atmosphere. Near-infrared reflecting titanium dioxide can reflect light in the visible light region, absorb light in the ultraviolet region, transmit light in the infrared region, or any combination of the three. Near-infrared reflective titanium dioxide has a strong reflective effect on infrared rays, which can reduce the absorption of heat by the substrate, reduce the surface temperature of the object and heat conduction, thereby reducing the temperature rise caused by solar infrared light and reducing the heat energy conducted to the interior of the house, playing a role of reflective heat insulation and cooling, while avoiding the breakage and degradation of polymer molecular chains caused by sunlight. Titanium dioxide can be selected from near-infrared reflective titanium dioxide IR1000 purchased from Dongjia Group, near-infrared reflective titanium dioxide IR600 purchased from Pan-China Chemical, or rutile titanium dioxide DR-2589 purchased from Pan-China Chemical. Among them, the weight ratio of rutile titanium dioxide to near-infrared reflective titanium dioxide is (0.5-1.0):1, for example (0.6-1.0):1; for example, rutile titanium dioxide DR-2589: near-infrared reflective titanium dioxide IR1000 is (0.5-1.0):1.

[0023] The aluminum silver powder particles in the aluminum silver paste are flaky, with a smooth surface, concentrated particle size distribution, regular shape, and excellent light reflection ability, which can reflect 60%-90% of visible light, ultraviolet light and infrared light. After the aluminum silver powder is dispersed in the waterproof coating of the present invention, it can be parallel to the coating film, and the particles can fill each other. Together with titanium dioxide and waterborne polyurethane dispersion, it forms a continuous organic-inorganic-metal composite coating film, which reflects visible light, ultraviolet light and infrared light, and further improves the light aging resistance of the coating film. The aluminum silver paste preferably uses at least one of TS1106 aluminum silver paste, TC5152 aluminum silver paste of Shanghai Yantai Industry, and LT-600 fine white silver paste of Dongguan Lantu Technology Materials Co., Ltd.

[0024] Sericite powder is a flaky structure with a diameter-to-thickness ratio of more than 80. After adding sericite powder to waterproof coatings, it will be arranged in flaky layers in the formed coating film, strongly blocking the penetration of water and other corrosive substances into the coating film, which can extend the penetration time of these substances into the coating film by 3 times. At the same time, sericite powder has excellent shielding capabilities of ultraviolet and infrared rays, as well as good infrared radiation capabilities, which can greatly improve the anti-ultraviolet and heat insulation properties of the coating film and slow down the aging rate of the waterproof coating film.

[0025] The light reflector may be a light reflective composition comprising titanium dioxide and aluminum silver paste in a weight ratio of (8-10): 1. Alternatively, the light reflector may be a light reflective composition comprising titanium dioxide, aluminum silver paste and sericite powder in a weight ratio of (8-10): 1: (1-3), for example (8-10): 1: 2.

[0026] The waterproof coating comprises 5-15%, for example 9-12%, of heat-insulating microspheres, based on the total weight of the waterproof coating. In the heat-insulating microspheres, the weight ratio of glass hollow microspheres, ceramic hollow microspheres and mineral wool is 1:(0.5-1):(0.5-1). The main component of the glass hollow microspheres is borosilicate, the particle size distribution is in the range of 10 to 250 μm, the wall thickness is 1 to 2 μm, and the density is 0.1 to 0.7 g / ml. The glass hollow microspheres are light in weight, large in volume, low in thermal conductivity, high in compressive strength, and have good dispersibility, fluidity and stability. Ceramic hollow microspheres are also called floating beads. They are usually white in color. Their chemical composition can be SiO2: 50-60%, Al2O3: 20-40%, Fe2O3: 0.5-3.5%, CaO: 0.5-5%, TiO2: 1-3%, MgO: 0.8-2%, K2O: 1-4%. Ceramic hollow microspheres are hollow spheres with very good fluidity. They can improve the rheology of waterproof coating systems and reduce the viscosity of coatings. The bulk density is 0.3-0.4g / cm 3, which can reduce the weight of the waterproof coating; and its thermal conductivity is small and its thermal resistance is large. Mineral wool is a cotton-like short fiber made from a silicate melt. The fiber length of mineral wool is 3000-7000μm, for example, 5000μm, and the fiber diameter is ≤9μm. Its thermal conductivity is low, and the thermal conductivity is usually 0.041-0.07 W / (m·K). Mineral wool has the characteristics of low density, light weight, good durability and non-flammability. It is an excellent thermal insulation material. The two hollow microspheres are composited and can complement each other in the microstructure to form a gradation of microspheres of different mesh sizes. At the same time, they are equipped with mineral wool fibers to form a spatial network structure of graded microspheres and fibers. The synergistic effect of its porous network structure can further improve the thermal resistance of the waterproof coating and reduce the thermal conductivity. At the same time, the dense coating also improves the impermeability or water-impermeability. The glass hollow microspheres can be selected from at least one of the hollow microspheres 5020 purchased from Zhejiang Zhongteng Environmental Protection Technology Co., Ltd. and the ultrafine hollow glass microspheres purchased from Lingshou County Baifeng Mineral Products Processing Factory; the ceramic hollow microspheres can be selected from at least one of the 150-200 mesh white ceramic hollow microspheres purchased from Shanghai Huijing Suba Nano New Materials Co., Ltd. or the 100-200 mesh thermal insulation hollow white bleached beads purchased from Lingshou County Dianjin Mineral Products Processing Factory; the mineral wool can be selected from the A-grade mineral fiber wool purchased from Hebei Chuou Insulation Materials Co., Ltd. or the thermal insulation mineral wool fiber purchased from Lingshou County Zishu Mineral Products Co., Ltd.

[0027] The waterproof coating contains 3-10%, for example 3-7%, of nano aerogel slurry, based on the total weight of the waterproof coating. The nano aerogel slurry is a slurry of polyurethane-modified silica aerogel, which is prepared from a slurry composition comprising an aqueous polyurethane dispersion of aerogel, nano fumed silica, water, and optionally other liquid additives. The nano aerogel slurry of the present invention is a paste-like mixture with a wet density of 0.3-0.9 g / cm 3 , for example 0.6 g / cm 3 , measured by the specific gravity cup method; the dry film thermal conductivity is 0.010-0.080W / (m·K), for example 0.035W / (m·K), measured by the heat flow method using a thermal conductivity measuring instrument; the dry film density is 100-3000kg / m 3 , for example 200kg / m 3 , measured using an electronic density meter.

[0028] The aqueous polyurethane dispersion for aerogel can be selected from the range defined by the aqueous polyurethane dispersion in the waterproof coating. The aqueous polyurethane dispersion for aerogel can be the same as or different from the aqueous polyurethane dispersion in the waterproof coating. Nano-fumed silica is silica particles prepared by chemical vapor deposition (CAV) method, with an average particle size of 10-50nm. Other additives include one or more of a dispersant, a wetting agent, a defoamer and a filler.

[0029] The nano aerogel slurry is prepared by a method comprising the following steps: adding water to a container and starting to stir at 100-300 r / min, for example, 200 r / min; adding a dispersant, a wetting agent, and a defoaming agent during stirring; adding an aqueous polyurethane dispersion for aerogel, adjusting the stirring rate to 300 r / min, and stirring for 1-15 min, for example, 5 min; then adding nano fumed silica and fillers, and mixing for 20-40 min at a high-speed stirring of 800-2000 r / min, for example, 1000 r / min, until the components are evenly dispersed, thereby obtaining the nano aerogel slurry.

[0030] Nano aerogel slurry has low density, high hydrophobicity, low thermal conductivity, etc. The nano skeleton formed by the nano aerogel slurry can keep the microscopic porous structure of the waterproof coating stable. It has a special three-dimensional network structure with a pore size smaller than the mean free path of air molecules, which can block all pathways of heat transfer: heat conduction, heat convection and heat radiation, thereby playing a good role in heat insulation; at the same time, the nano aerogel slurry can increase the thickness of the waterproof coating, thereby improving the thermal insulation effect of the waterproof coating.

[0031] The waterproof coating contains 5-10%, for example 6.9-10%, of water, based on the total weight of the waterproof coating. The water is municipal tap water, which functions to reduce the viscosity of the coating and help the dispersion of powder and filler.

[0032] The waterproof coating contains 5-10%, for example 6-10%, of filler, based on the total weight of the waterproof coating. The filler is selected from one or more of heavy calcium carbonate, wollastonite powder, and calcined kaolin with an average particle size of 800 mesh or 1500 mesh. The filler can play a skeleton role, increase the volume, increase the thickness of the coating, reduce the thermal conductivity of the coating, and improve the compactness, impermeability, and weather resistance of the waterproof coating.

[0033] The waterproof coating contains 0.5-10%, such as 0.9-6%, of other functional additives, based on the total weight of the waterproof coating. Other functional additives include one or more of bactericides and preservatives, wetting and dispersing agents, defoaming agents, silane coupling agents, film-forming aids, and mildew inhibitors.

[0034] The bactericidal and mildewproof agent may include a bactericide or a mildewproof agent, etc. The bactericide may be an isothiazolinone bactericide or a kason bactericide. The bactericide is used to prevent the degradation of the water-based coating system by microorganisms, thereby solving a series of problems such as deterioration, fermentation, stink, and demulsification of the waterproof coating caused by bacterial infection. The bactericide may be, for example, KSG102K and SG103 bactericides purchased from Guangdong Dimei Biotechnology Co., Ltd. The mildewproof agent is at least one of phenols, chlorophenols, organic mercury salts, organic copper salts, organic tin salts, and inorganic salts such as copper sulfate, mercuric chloride, and sodium fluoride, which can effectively inhibit the reproduction and production of mold on the waterproof coating, prevent the mildew phenomenon of the coating caused by microorganisms, effectively avoid the formation of mildew spots on the coating surface, and prevent the mildew spots from affecting the reflective heat insulation function of the waterproof coating. The mildewproof agent can be selected from the mildewproof agent TC-20 purchased from Foshan Nanya Chemical Co., Ltd.

[0035] The wetting and dispersing agent may include one or more inorganic dispersants or organic dispersants, and the wetting and dispersing agent may reduce the viscosity of the coating, improve the wettability and dispersibility of the filler in the coating, prevent the sedimentation of the filler, and improve the storage stability of the coating. The wetting and dispersing agent may be at least one of the dispersant SN5040 purchased from San Nopco, the dispersant BYK190 purchased from BYK Chemical of Germany, and the wetting agent BD-109 purchased from Dow Chemical.

[0036] Defoamers may include one or more of mineral oils, silicones, and polyethers; defoamers can eliminate or reduce bubbles generated during the production and construction of coatings, and improve the density of the coating film. The defoamer can be selected from at least one of the following: NOPCO NXZ defoamer purchased from San Nopco, Japan, BYKETOL-AQ and BYKETOL-WS purchased from BYK Chemicals, Germany, and BYK012 defoamer purchased from BYK Chemicals, Germany; BYKETOL-AQ and BYKETOL-WS are defoamers with leveling properties, which prevent bubble marks (such as pinholes or craters) generated when bubbles are eliminated during construction.

[0037] The silane coupling agent may include one or more of vinyl triethoxysilane, vinyl trimethoxysilane, vinyl tri(β-methoxyethoxy)silane, aminopropyl triethoxysilane, glycidyl methoxypropyl trimethoxysilane, methacryloxypropyl trimethoxysilane, ethylenediaminopropyl triethoxysilane, and ethylenediaminopropyl methyl dimethoxysilane. The molecular structure of the silane coupling agent contains organic functional groups and silaneoxy groups, has cross-linking reactivity to both organic and inorganic substances, can react or "couple" with the surface of organic polymers and inorganic substances, can improve the cross-linking density and / or cross-linking strength between fillers in the waterproof coating, between heat-insulating microbeads and polymers, and between the coating and the base layer, so that the water resistance and durability of the waterproof coating can be significantly improved after the addition of the silane coupling agent. Silane coupling agents can be selected from γ-aminopropyl triethoxysilane KH550 and γ-glycidyloxypropyl trimethoxysilane KS560 purchased from Hangzhou Jessica Chemical Co., Ltd.; silane coupling agents γ-glycidyl ether propyl trimethoxysilane Z-6040 and γ-methacryloxypropyl trimethoxysilane KH570 purchased from Dow Corning, USA.

[0038] The film-forming aid may include one or more of alcohol ester 12, dipropylene glycol methyl ether, propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol butyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether and tripropylene glycol n-butyl ether. The film-forming aid softens the emulsion polymer particles, promotes the plastic flow and elastic deformation of the polymer latex particles, and fuses them together to form a continuous film. The film-forming aid may be one or more of alcohol ester 12, propylene glycol butyl ether and dipropylene glycol monopropyl ether.

[0039] Among the additives used in the preparation of nano-aerogels and waterproof coatings, if they are additives with the same functions, they have the same definition range; for example, the defoaming agent used in the preparation of nano-aerogels has the same definition and optional range as the defoaming agent used in waterproof coatings.

[0040] The preparation method of the waterproof coating comprises:

[0041] Mix water and waterborne polyurethane dispersion evenly to obtain mixture A; then add light reflector and filler to mixture A and disperse evenly to obtain mixture B; add nano aerogel, heat insulating micro beads and other functional additives to mixture B and mix evenly to obtain waterproof coating.

[0042] Optionally, the preparation method of the waterproof coating comprises:

[0043] After mixing water and a bactericide and mildew preventer, the mixture is added into an aqueous polyurethane dispersion and mixed evenly to obtain a mixture A; then a wetting dispersant, a defoaming agent, titanium dioxide, sericite powder, and a filler are added into the mixture A and dispersed evenly to obtain a mixture B; nano aerogel, aluminum silver paste, heat insulating microbeads, a silane coupling agent, and a film-forming aid are added into the mixture B and mixed evenly to obtain a waterproof coating.

[0044] Optionally, the preparation method of the waterproof coating comprises:

[0045] Put the waterborne polyurethane dispersion into a stirring kettle and stir at a speed of 300r / min to 500r / min;

[0046] After mixing the bactericide and mildew preventer with water, gradually add them into the above stirring kettle under the above stirring, and keep stirring;

[0047] gradually adding the wetting and dispersing agent and the defoaming agent into the stirring kettle under the above stirring;

[0048] Add titanium dioxide, sericite powder and filler in sequence, increase the speed to 800-1000r / min, and disperse at high speed for 5-20 minutes;

[0049] Then adjust the speed to 300-500r / min, add nano aerogel, aluminum silver paste, thermal insulation microbeads, silane coupling agent, and film-forming aid in sequence, and continue stirring for 10-25min; the thermal insulation microbeads are added step by step, that is, the amount added each time is 1 / 2 of the remaining microbeads, and they are added gradually with an interval of 5-10min between each step to prevent the microbeads from floating into the air and to make the dispersion more complete to obtain a waterproof coating.

[0050] The waterproof coating as described above is used in preparing a waterproof coating film with heat insulation performance for the exterior wall or roof of a building. The thickness of the waterproof coating film is 1-2.5 mm, for example, 1.5 mm, and can be directly exposed for use. The waterproof coating of the embodiment of the present invention can be coated on the exterior wall or roof of a building in one or more layers, which can be selected by those skilled in the art according to needs.

[0051] The present invention is described below by specific examples. The examples described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. If no specific techniques or conditions are specified in the examples, the techniques or conditions described in the literature in this area or the product instructions are used. If the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be obtained commercially.

[0052] raw material

[0053]

[0054]

[0055] 1. Preparation of Nano-aerogel Glue

[0056] Glue Example 1

[0057] S1. Add 32.5 parts of clean water into the dispersion tank and start stirring at a speed of 200 r / min;

[0058] S2, add in stirring BYK-W996 Dispersant 7 parts, EH-9 wetting agent 5 parts; BYK024 defoamer 0.5 parts;

[0059] S3. Investment 8355 waterborne polyurethane dispersion 35 parts, the disperser speed is adjusted to 300r / min;

[0060] S4. Add 8 parts of nano-fumed silica and 12 parts of 1500 mesh heavy calcium filler while dispersing. After the powder is added, disperse at a high speed of 1000r / min for about 30 minutes until the dispersion is uniform.

[0061] The components used to prepare the nano aerogel slurry are summarized in Table 1. The properties of the obtained nano aerogel slurry are summarized in Table 1.

[0062] Glue Example 2 and Glue Comparative Example 1

[0063] The steps of Example 1 of the mortar were repeated, except for the amounts of the components used, as shown in Table 1.

[0064] Table 1 Composition and properties of nano aerogel slurry examples and comparative examples

[0065]

[0066] 2. Preparation of waterproof coating

[0067] Example 1

[0068] According to the proportion of each substance in Table 2, the aqueous polyurethane dispersion is put into a stirring kettle and stirred at a speed of 400r / min; after the fungicide, mildewproof agent and water are mixed, they are gradually put into the above stirring kettle under the above stirring and kept stirring; the wetting dispersant and defoaming agent are gradually put into the above stirring kettle under the above stirring; titanium dioxide, sericite powder and filler are added in sequence, the speed is increased to 1000r / min, and high-speed dispersion is carried out for 10 minutes; then the speed is adjusted to 400r / min, and the nano aerogel glue prepared in glue example 1, aluminum silver paste, thermal insulation microbeads (glass hollow microbeads: ceramic hollow microbeads: mineral wool weight ratio is 1:0.6:0.5), silane coupling agent, and film-forming aid are added in sequence, and stirring is continued for 15min; wherein the thermal insulation microbeads are added step by step, that is, the amount added each time is 1 / 2 of the remaining microbeads, and they are added step by step, and each step is separated by 5min to prevent the microbeads from floating into the air and to make the dispersion more complete, so as to obtain a waterproof coating.

[0069] The compositions of the prepared waterproof coatings are summarized in Table 2.

[0070] Embodiment 2-5

[0071] The steps of Example 1 were repeated, except that the proportions of the components in the waterproof coating were different. The compositions of the prepared waterproof coating are summarized in Table 2.

[0072] Example 6

[0073] The steps of Example 1 were repeated, except that in the preparation of the thermal insulation microspheres in the waterproof coating, the amount of each component was changed, and the weight ratio of glass hollow microspheres: ceramic hollow microspheres: mineral wool was 1:1:1. The composition of the prepared waterproof coating is summarized in Table 2.

[0074] Example 7

[0075] The steps of Example 1 were repeated, except that in the preparation of the thermal insulation microspheres in the waterproof coating, the amount of each component was changed, and the weight ratio of glass hollow microspheres: ceramic hollow microspheres: mineral wool was 1:0.5:1. The composition of the prepared waterproof coating is summarized in Table 2.

[0076] Example 8

[0077] The steps of Example 1 were repeated, except that the nano-aerogel mortar prepared in mortar Example 2 was used. The composition of the prepared waterproof coating is summarized in Table 2.

[0078] Example 9

[0079] The steps of Example 1 were repeated except that no sericite powder was added. The compositions of the prepared waterproof coatings are summarized in Table 2.

[0080] Examples 10-12

[0081] The procedure of Example 1 was repeated, except that only the weight ratio of each component in the thermal insulation microbeads was changed.

[0082] Comparative Example 1-2

[0083] Without preparing the nano-aerogel, the preparation of the waterproof coating in Example 1 was repeated, except for the type and amount of each component added. The composition of the prepared waterproof coating is summarized in Table 2.

[0084] Comparative Example 3

[0085] The steps of Example 1 were repeated, but the difference was the content of each component in preparing the waterproof coating. The composition of the prepared waterproof coating is summarized in Table 2.

[0086] Comparative Example 4

[0087] The steps of Example 1 were repeated, but the difference was that the nano aerogel mortar prepared in mortar comparative example 1 was used. The composition of the prepared waterproof coating is summarized in Table 2.

[0088]

[0089] Performance Testing

[0090] 1) Adhesion performance

[0091] The bonding properties of the waterproof coatings of the embodiments and comparative examples were measured according to GB / T16777-2008.

[0092] 2) Waterproof performance

[0093] The waterproof properties of the waterproof coatings of the embodiments and comparative examples were measured according to JC / T 864-2023.

[0094] 3) Weather resistance

[0095] The weather resistance of the waterproof coatings of the embodiments and comparative examples was determined according to GB / T1865-2009.

[0096] 4) Thermal insulation performance

[0097] The thermal insulation properties of the waterproof coatings of each embodiment and comparative example were measured according to GB / T25261-2018.

[0098] 5) Anti-mildew performance The anti-mildew performance of the waterproof coatings of each embodiment and comparative example was measured according to GB / T 1741-2007.

[0099] The performance test results are summarized in Table 3.

[0100]

[0101] According to the technical solution of the embodiment of the present invention, under the combined action of a specific content of light reflector, thermal insulation microbeads, and waterborne polyurethane, the waterproof coating of the present invention has excellent thermal insulation performance, weather resistance, bonding performance, and waterproof performance, especially its thermal insulation performance is significantly improved.

[0102] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions may occur depending on design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A waterproof coating, characterized in that: The waterproof coating comprises 35-60% of aqueous polyurethane dispersion, 10-13% of light reflector, 5-15% of heat-insulating microbeads, 3-10% of nano aerogel glue, 5-10% of water, 5-10% of filler, and 0.5-10% of other functional additives, based on the total weight of the waterproof coating; The thermal insulation microspheres include glass hollow microspheres, ceramic hollow microspheres and mineral wool.

2. The waterproof coating according to claim 1, characterized in that: The light reflector includes one or more of titanium dioxide, aluminum silver paste, and sericite powder.

3. The waterproof coating according to claim 2, characterized in that: The titanium dioxide is a mixture of rutile titanium dioxide and near-infrared reflecting titanium dioxide.

4. The waterproof coating according to claim 3, characterized in that: The weight ratio of the rutile titanium dioxide to the near-infrared reflecting titanium dioxide is (0.5-1.0):

1.

5. The waterproof coating according to claim 1 or 2, characterized in that: The light reflector is a light reflective composition comprising titanium dioxide and aluminum silver paste in a weight ratio of (8-10):

1.

6. The waterproof coating according to claim 1 or 2, characterized in that: The weight ratio of the glass hollow microspheres, the ceramic hollow microspheres and the mineral wool is 1:(0.5-1):(0.5-1).

7. The waterproof coating according to claim 1 or 2, characterized in that: The nano-aerogel mortar is a mortar of polyurethane-modified silica aerogel, which is prepared from a mortar composition comprising an aqueous polyurethane dispersion for aerogel, nano-aerosilicic acid, water, and optionally other liquid additives.

8. The waterproof coating according to claim 1 or 2, characterized in that: The wet density of the nano aerogel slurry is 0.3-0.9 g / cm 3 ; Dry film thermal conductivity is 0.010-0.080W / (m·K); Dry film density is 100-3000kg / m 3 .

9. The waterproof coating according to claim 1 or 2, characterized in that: The other functional additives include one or more of bactericidal preservatives, wetting and dispersing agents, defoaming agents, silane coupling agents, film-forming aids, and mildew inhibitors.

10. Use of the waterproof coating according to any one of claims 1 to 9 in preparing a waterproof coating film with heat insulation performance for the exterior wall or roof of a building.

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