Thermal insulation material for building external wall and preparation method of thermal insulation material

Abstract

The invention relates to the field of thermal insulation materials for building external walls, in particular to a thermal insulation material for a building external wall and a preparation method thereof, which are used for solving the problems of unsatisfactory thermal insulation performance and poor durability of the conventional thermal insulation material for the building external wall. The thermal insulation material for the building external wall is endowed with an excellent thermal insulation effect by adding the aluminum-silicon aerogel, the thermal insulation performance of the thermal insulation material can be further improved after the light-absorbing polyurethane is used, meanwhile, the illumination stability of the thermal insulation material is remarkably improved, the thermal insulation material can keep high performance for a long time under the illumination condition, and the durability of the thermal insulation material is greatly improved; moreover, the preparation method is simple, easy to operate and suitable for large-scale production, and the prepared heat-preservation and heat-insulation coating material can be widely applied to heat-preservation and heat-insulation projects of various building outer walls, such as residences, commercial buildings, industrial factory buildings and the like, and has a wide market prospect.

Description

Technical Field

[0001] The invention relates to the field of thermal insulation materials for building exterior walls, and in particular to a thermal insulation material for building exterior walls and a preparation method thereof. Background Art

[0002] With the intensification of the global energy crisis and the improvement of people's awareness of environmental protection, building energy conservation has become the focus of today's society, and the performance of building exterior wall thermal insulation materials has received more and more attention. Traditional thermal insulation materials, such as cement expanded perlite insulation mortar, expanded vermiculite, asbestos and other inorganic thermal insulation materials, have the disadvantages of strong water absorption, high thermal conductivity, and high construction difficulty, and have been gradually eliminated. As a new type of building energy-saving material, building exterior wall thermal insulation coatings have been widely concerned and applied due to their convenient construction. However, the building exterior wall thermal insulation coatings currently on the market generally have problems such as unsatisfactory thermal insulation performance and poor durability. Therefore, it is of great practical significance to develop a thermal insulation material for building exterior walls and a preparation method thereof. Summary of the invention

[0003] In order to overcome the above-mentioned technical problems, the purpose of the present invention is to provide a thermal insulation material for building exterior walls and a preparation method thereof. The thermal insulation material for building exterior walls is obtained by adding light-absorbing polyurethane, aluminum silicate aerogel, dispersant, wetting and leveling agent, thickener, defoaming agent and deionized water into a mixer and stirring and mixing, thereby solving the problem that the thermal insulation performance and durability of existing thermal insulation materials for building exterior walls are not ideal.

[0004] The purpose of the present invention can be achieved through the following technical solutions: A thermal insulation material for building exterior walls, comprising the following components in parts by weight: 40-50 parts of light-absorbing polyurethane, 2-11 parts of aluminum-silicon aerogel, 0.5-1.1 parts of dispersant, 0.3-0.6 parts of wetting and leveling agent, 1-3 parts of thickener, 0.1-0.5 parts of defoamer and 100-120 parts of deionized water; Wherein, the aluminum silicate aerogel is prepared by the following steps: Step a1: adding aluminum chloride hexahydrate, anhydrous ethanol and deionized water into a three-necked flask equipped with a stirrer and a thermometer, stirring the mixture for 20-30 minutes at a temperature of 25-30° C. and a stirring rate of 300-400 r / min, then adding propylene oxide and continuing the stirring reaction for 2-3 hours to obtain an aluminum-containing solution; Step a2: adding anhydrous ethanol and deionized water into a three-necked flask equipped with a stirrer, a thermometer and a constant pressure dropping funnel, adding ethyl orthosilicate dropwise while stirring at a temperature of 25-30°C and a stirring rate of 300-400r / min, controlling the dropping rate to 1-2 drops / s, and continuing to stir and react for 2-3h after the dropwise addition is completed, and then adjusting the pH to 1-2 with a hydrochloric acid solution to obtain a silicon-containing solution; Step a3: Add the aluminum-containing solution and the silicon-containing solution to a three-necked flask equipped with a stirrer and a thermometer, stir and react for 10-15 hours at a temperature of 25-30°C and a stirring rate of 300-400r / min, then let it stand for aging for 24-36 hours, then add γ-aminopropyltriethoxysilane and continue stirring and reacting for 2-3 hours. After the reaction is completed, place the reaction product in a refrigerator, freeze it at a temperature of -20°C for 10-12 hours, and then place it in a freeze dryer and freeze-dry it at a temperature of -80°C for 20-30 hours to obtain aluminum silicate aerogel.

[0005] As a further solution of the present invention: the usage ratio of the aluminum chloride hexahydrate, anhydrous ethanol, deionized water and propylene oxide in step a1 is 2-8 g: 40-50 mL: 40-50 mL: 8-12 mmol.

[0006] As a further solution of the present invention: the usage ratio of the anhydrous ethanol, deionized water and tetraethyl orthosilicate in step a2 is 40-50 mL: 40-50 mL: 2-8 g.

[0007] As a further solution of the present invention: the mass fraction of the hydrochloric acid solution in step a2 is 12-15%.

[0008] As a further solution of the present invention: the aluminum-containing solution, silicon-containing solution and γ-aminopropyltriethoxysilane in step a3 are used in a ratio of 40-50 mL: 40-50 mL: 0.5-5.5 mL.

[0009] As a further solution of the present invention: the light-absorbing polyurethane is prepared by the following steps: Step b1: 2,6-dibromophenol and benzene are added to a three-necked flask equipped with a stirrer, a thermometer and an air guide tube, and nitrogen is introduced for protection. The mixture is stirred for reaction at a temperature of 25-30° C. and a stirring rate of 300-400 r / min for 20-30 min, and then 2,4-dihydroxybenzophenone, sodium hydroxide and deionized water are added and stirred for reaction for 20-30 min. The mixture is then heated to 40-45° C. and stirred for reaction for 5-6 h. After the reaction is completed, the reaction product is cooled to room temperature, and then the solvent is removed by rotary evaporation, and then column chromatography separation and purification are performed with an eluent to obtain a light absorption enhancer; Step b2: Add polycarbonate diol, isophorone diisocyanate, dibutyltin dilaurate and tetrahydrofuran into a three-necked flask equipped with a stirrer, a thermometer, an air duct and a reflux condenser, introduce nitrogen protection, stir and react for 10-15 minutes at a temperature of 20-25°C and a stirring rate of 300-400r / min, then heat to 75-80°C and continue to stir and react for 2-3 hours, then add 2,2-dihydroxymethylpropionic acid and continue to stir and react for 1-1.5 hours, then add a light absorption enhancer and continue to stir and react for 2-3 hours, after the reaction is completed, cool the reaction product to room temperature, then place it in a vacuum drying oven, and dry it at a temperature of 80-85°C for 2-3 hours to obtain a light-absorbing polyurethane.

[0010] As a further scheme of the present invention: the usage ratio of the 2,6-dibromophenol, benzene, 2,4-dihydroxybenzophenone, sodium hydroxide and deionized water in step b1 is 10 mmol: 30-40 mL: 20 mmol: 22-25 mmol: 40-50 mL.

[0011] As a further solution of the present invention: the eluent in step b1 is a mixture of ethyl acetate and petroleum ether in a volume ratio of 1:7-9.

[0012] As a further scheme of the present invention: the usage ratio of the polycarbonate diol, isophorone diisocyanate, dibutyltin dilaurate, tetrahydrofuran, 2,2-dihydroxymethylpropionic acid and light absorption enhancer in step b2 is 18-20g:8.5-10.5g:0.01-0.02g:50-55mL:1.5-1.9g:1.1-2.3g.

[0013] As a further solution of the present invention: the polycarbonate diol in step b2 is PCDL1000.

[0014] As a further solution of the present invention: a method for preparing a thermal insulation material for building exterior walls comprises the following steps: Step 1: Weigh 40-50 parts of light-absorbing polyurethane, 2-11 parts of aluminum silicate aerogel, 0.5-1.1 parts of dispersant, 0.3-0.6 parts of wetting and leveling agent, 1-3 parts of thickener, 0.1-0.5 parts of defoamer and 100-120 parts of deionized water according to weight parts, and set aside; Step 2: Add light-absorbing polyurethane, aluminum silicate aerogel, dispersant, wetting and leveling agent, thickener, defoamer and deionized water into a mixer, stir and mix for 2-3 hours at a temperature of 40-45°C and a stirring rate of 300-400r / min to obtain thermal insulation material for building exterior walls.

[0015] As a further solution of the present invention: the dispersant is SN-5040 dispersant; the wetting and leveling agent is LW-440 wetting and leveling agent; the thickener is sodium carboxymethyl cellulose; and the defoamer is BYK-028 water-based defoamer.

[0016] Beneficial effects of the present invention: The invention discloses a thermal insulation material for building exterior walls and a preparation method thereof. The thermal insulation material for building exterior walls is obtained by adding light-absorbing polyurethane, aluminum-silicon aerogel, a dispersant, a wetting and leveling agent, a thickener, a defoaming agent and deionized water into a mixer and stirring and mixing. The thermal insulation material for building exterior walls is endowed with excellent thermal insulation effect by adding aluminum-silicon aerogel, and the thermal insulation performance can be further improved after using light-absorbing polyurethane, and the light stability is significantly improved, so that the high performance can be maintained for a long time under light conditions, and the durability is greatly improved. Moreover, the preparation method is simple, easy to operate, and suitable for large-scale production. The prepared thermal insulation coating material can be widely used in thermal insulation projects of various building exterior walls, such as residential buildings, commercial buildings, industrial plants, etc., and has broad market prospects.

[0017] In the process of preparing thermal insulation materials for building exterior walls, an aluminum silicate aerogel is first prepared. First, aluminum chloride hexahydrate is used as a raw material to form an aluminum solution, and tetraethyl orthosilicate is used as a raw material to form a silicon solution. Finally, the aluminum solution and the silicon solution are mixed and hydrolyzed, and then subjected to sol-gel and freeze-drying to obtain aluminum silicate aerogel. Silica aerogel has an extremely low density, and has an extremely high porosity and nanometer-scale pore size, so that its thermal conductivity is small, giving it excellent thermal insulation performance. Alumina aerogel has better temperature resistance and mechanical strength than silica aerogel. After the two are compounded, the composite structure of the aluminum silicate aerogel obtained has a higher porosity and a lower density, thereby improving its thermal insulation performance, and at the same time, giving it high temperature stability and mechanical strength. After being modified with γ-aminopropyltriethoxysilane, its dispersibility is greatly improved, and a large number of amino groups are introduced, so that it can be connected with other raw materials in the form of chemical bonds, making it more suitable for thermal insulation materials for building exterior walls, giving it excellent thermal insulation performance.

[0018] In the process of preparing the thermal insulation material for building exterior walls, a light-absorbing polyurethane is also prepared. First, 2,6-dibromophenol and 2,4-dihydroxybenzophenone are reacted, and the bromine atom on the 2,6-dibromophenol reacts with a hydroxyl group on the 2,4-dihydroxybenzophenone to obtain a light-absorbing enhancer. Then, polycarbonate diol, isophorone diisocyanate and 2,2-dihydroxymethyl propionic acid are polymerized to form polyurethane, and the polyurethane is modified by the light-absorbing enhancer. The hydroxyl group on the light-absorbing enhancer can react with the isocyanate group and the carboxyl group in the polyurethane to form a light-absorbing polyurethane containing a large amount of benzophenone structure. The benzophenone structure on the light-absorbing polyurethane has excellent ultraviolet absorption performance, further blocks the heat insulation effect of sunlight on the building by directly reducing the heat of sunlight, and can effectively protect the polyurethane from being eroded by ultraviolet rays, thereby ensuring that the thermal insulation material for building exterior walls can maintain high performance for a long time, extending the service life of the thermal insulation material for building exterior walls, and enabling the building exterior walls to maintain good appearance and performance. DETAILED DESCRIPTION

[0019] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Embodiment 1:

[0021] This embodiment is a method for preparing a thermal insulation material for building exterior walls, comprising the following steps: Step S1: 2 g of aluminum chloride hexahydrate, 40 mL of anhydrous ethanol and 40 mL of deionized water were added to a three-necked flask equipped with a stirrer and a thermometer, and stirred for reaction at a temperature of 25° C. and a stirring rate of 300 r / min for 20 min, and then 8 mmol of propylene oxide was added and the stirring reaction was continued for 2 h to obtain an aluminum-containing solution; Step S2: Add 40 mL of anhydrous ethanol and 40 mL of deionized water into a three-necked flask equipped with a stirrer, a thermometer and a constant pressure dropping funnel, add 2 g of ethyl orthosilicate dropwise while stirring at a temperature of 25° C. and a stirring rate of 300 r / min, and control the dropping rate to be 1 drop / s. After the dropwise addition is completed, continue stirring and reacting for 2 hours, and then adjust the pH to 1 with a hydrochloric acid solution with a mass fraction of 12% to obtain a silicon-containing solution; Step S3: Add 40 mL of aluminum-containing solution and 40 mL of silicon-containing solution to a three-necked flask equipped with a stirrer and a thermometer, stir and react for 10 hours at a temperature of 25°C and a stirring rate of 300 r / min, then stand and age for 24 hours, then add 0.5 mL of γ-aminopropyltriethoxysilane and continue stirring and reacting for 2 hours. After the reaction is completed, place the reaction product in a refrigerator, freeze it at a temperature of -20°C for 10 hours, and then place it in a freeze dryer and freeze-dry it at a temperature of -80°C for 20 hours to obtain aluminum silicate aerogel; Step S4: 10 mmol 2,6-dibromophenol and 30 mL benzene are added to a three-necked flask equipped with a stirrer, a thermometer and an air guide tube, and nitrogen is introduced for protection. The mixture is stirred and reacted for 20 min at a temperature of 25° C. and a stirring rate of 300 r / min. Then, 20 mmol 2,4-dihydroxybenzophenone, 22 mmol sodium hydroxide and 40 mL deionized water are added and stirred and reacted for 20 min. Then, the mixture is heated to 40° C. and stirred and reacted for 5 h. After the reaction is completed, the reaction product is cooled to room temperature, and then the solvent is removed by rotary evaporation. Then, column chromatography is performed to separate and purify the mixture with an eluent prepared by mixing ethyl acetate and petroleum ether in a volume ratio of 1:7 to obtain an absorbance enhancer. Step S5: 18 g of polycarbonate diol PCDL1000, 8.5 g of isophorone diisocyanate, 0.01 g of dibutyltin dilaurate and 50 mL of tetrahydrofuran were added to a three-necked flask equipped with a stirrer, a thermometer, an air duct and a reflux condenser, and nitrogen was introduced for protection. The mixture was stirred for reaction at 20° C. and a stirring rate of 300 r / min for 10 min, and then the mixture was heated to 75° C. and stirred for reaction for 2 h. Then 1.5 g of 2,2-dimethylolpropionic acid was added and stirred for reaction for 1 h, and then 1.1 g of a light absorption enhancer was added and stirred for reaction for 2 h. After the reaction was completed, the reaction product was cooled to room temperature, and then placed in a vacuum drying oven and dried at 80° C. for 2 h to obtain a light-absorbing polyurethane. Step S6: 40 parts of light-absorbing polyurethane, 2 parts of aluminum silicate aerogel, 0.5 parts of dispersant, 0.3 parts of wetting and leveling agent, 1 part of thickener, 0.1 parts of defoamer and 100 parts of deionized water are weighed in parts by weight for use; the dispersant is SN-5040 dispersant; the wetting and leveling agent is LW-440 wetting and leveling agent; the thickener is sodium carboxymethyl cellulose; the defoamer is BYK-028 water-based defoamer; Step S7: Add light-absorbing polyurethane, aluminum silicate aerogel, dispersant, wetting and leveling agent, thickener, defoamer and deionized water into a mixer, stir and mix for 2 hours at a temperature of 40° C. and a stirring rate of 300 r / min to obtain thermal insulation material for building exterior walls.

[0022] Embodiment 2:

[0023] This embodiment is a method for preparing a thermal insulation material for building exterior walls, comprising the following steps: Step S1: 5 g of aluminum chloride hexahydrate, 45 mL of anhydrous ethanol and 45 mL of deionized water were added to a three-necked flask equipped with a stirrer and a thermometer, and stirred for reaction for 25 min at a temperature of 28° C. and a stirring rate of 350 r / min, and then 10 mmol of propylene oxide was added and the stirring reaction was continued for 2.5 h to obtain an aluminum-containing solution; Step S2: Add 45 mL of anhydrous ethanol and 45 mL of deionized water into a three-necked flask equipped with a stirrer, a thermometer and a constant pressure dropping funnel, add 5 g of ethyl orthosilicate dropwise while stirring at a temperature of 28° C. and a stirring rate of 350 r / min, and control the dropping rate to 1 drop / s. After the dropwise addition is completed, continue stirring and reacting for 2.5 hours, and then adjust the pH to 1.5 with a hydrochloric acid solution with a mass fraction of 14% to obtain a silicon-containing solution; Step S3: Add 45 mL of aluminum-containing solution and 45 mL of silicon-containing solution to a three-necked flask equipped with a stirrer and a thermometer, stir and react for 12 hours at a temperature of 28° C. and a stirring rate of 350 r / min, then stand and age for 30 hours, then add 3 mL of γ-aminopropyltriethoxysilane and continue stirring and reacting for 2.5 hours. After the reaction is completed, place the reaction product in a refrigerator, freeze it at a temperature of -20° C. for 11 hours, and then place it in a freeze dryer and freeze-dry it at a temperature of -80° C. for 25 hours to obtain aluminum silicate aerogel; Step S4: 10 mmol 2,6-dibromophenol and 35 mL benzene are added to a three-necked flask equipped with a stirrer, a thermometer and an air guide tube, and nitrogen is introduced for protection. The mixture is stirred for reaction at a temperature of 28° C. and a stirring rate of 350 r / min for 25 min, and then 20 mmol 2,4-dihydroxybenzophenone, 24 mmol sodium hydroxide and 45 mL deionized water are added to continue stirring for reaction for 25 min, and then the mixture is heated to 42° C. and continued to stir for reaction for 5.5 h. After the reaction is completed, the reaction product is cooled to room temperature, and then the solvent is removed by rotary evaporation, and then column chromatography separation and purification is performed using an eluent prepared by mixing ethyl acetate and petroleum ether in a volume ratio of 1:8 to obtain an absorbance enhancer; Step S5: 19 g of polycarbonate diol PCDL1000, 9.5 g of isophorone diisocyanate, 0.015 g of dibutyltin dilaurate and 52 mL of tetrahydrofuran were added to a three-necked flask equipped with a stirrer, a thermometer, an air duct and a reflux condenser, and nitrogen was introduced for protection. The mixture was stirred for reaction at a temperature of 22° C. and a stirring rate of 350 r / min for 12 min, and then the temperature was raised to 78° C. and the stirring reaction was continued for 2.5 h. Then, 1.7 g of 2,2-dimethylolpropionic acid was added and the stirring reaction was continued for 1.2 h. Then, 1.7 g of a light absorption enhancer was added and the stirring reaction was continued for 2.5 h. After the reaction was completed, the reaction product was cooled to room temperature, and then placed in a vacuum drying oven and dried at a temperature of 82° C. for 2.5 h to obtain a light-absorbing polyurethane; Step S6: 45 parts of light-absorbing polyurethane, 6.5 parts of aluminum silicate aerogel, 0.8 parts of dispersant, 0.5 parts of wetting and leveling agent, 2 parts of thickener, 0.3 parts of defoamer and 110 parts of deionized water are weighed in parts by weight for use; the dispersant is SN-5040 dispersant; the wetting and leveling agent is LW-440 wetting and leveling agent; the thickener is sodium carboxymethyl cellulose; the defoamer is BYK-028 water-based defoamer; Step S7: Add light-absorbing polyurethane, aluminum silicate aerogel, dispersant, wetting and leveling agent, thickener, defoamer and deionized water into a mixer, stir and mix for 2.5 hours at a temperature of 42° C. and a stirring rate of 350 r / min to obtain thermal insulation material for building exterior walls.

[0024] Embodiment 3:

[0025] This embodiment is a method for preparing a thermal insulation material for building exterior walls, comprising the following steps: Step S1: 8 g of aluminum chloride hexahydrate, 50 mL of anhydrous ethanol and 50 mL of deionized water were added to a three-necked flask equipped with a stirrer and a thermometer, and stirred for reaction at a temperature of 30° C. and a stirring rate of 400 r / min for 30 min, and then 12 mmol of propylene oxide was added and the stirring reaction was continued for 3 h to obtain an aluminum-containing solution; Step S2: Add 50 mL of anhydrous ethanol and 50 mL of deionized water into a three-necked flask equipped with a stirrer, a thermometer and a constant pressure dropping funnel, add 8 g of ethyl orthosilicate dropwise while stirring at a temperature of 30° C. and a stirring rate of 400 r / min, and control the dropping rate to 2 drops / s. After the dropwise addition is completed, continue stirring and reacting for 3 hours, and then adjust the pH to 2 with a hydrochloric acid solution with a mass fraction of 15% to obtain a silicon-containing solution; Step S3: Add 50 mL of aluminum-containing solution and 50 mL of silicon-containing solution to a three-necked flask equipped with a stirrer and a thermometer, stir and react for 15 hours at a temperature of 30°C and a stirring rate of 400 r / min, then stand and age for 36 hours, then add 5.5 mL of γ-aminopropyltriethoxysilane and continue stirring and reacting for 3 hours. After the reaction is completed, place the reaction product in a refrigerator, freeze it at a temperature of -20°C for 12 hours, and then place it in a freeze dryer and freeze-dry it at a temperature of -80°C for 30 hours to obtain aluminum silicate aerogel; Step S4: 10 mmol 2,6-dibromophenol and 40 mL benzene are added to a three-necked flask equipped with a stirrer, a thermometer and an air guide tube, and nitrogen is introduced for protection. The mixture is stirred for reaction at a temperature of 30° C. and a stirring rate of 400 r / min for 30 min, and then 20 mmol 2,4-dihydroxybenzophenone, 25 mmol sodium hydroxide and 50 mL deionized water are added and the stirring reaction is continued for 30 min. The mixture is then heated to 45° C. and the stirring reaction is continued for 6 h. After the reaction is completed, the reaction product is cooled to room temperature, and then the solvent is removed by rotary evaporation. Then, column chromatography separation and purification are performed using an eluent prepared by mixing ethyl acetate and petroleum ether in a volume ratio of 1:9 to obtain an absorbance enhancer; Step S5: 20 g of polycarbonate diol PCDL1000, 10.5 g of isophorone diisocyanate, 0.02 g of dibutyltin dilaurate and 55 mL of tetrahydrofuran were added to a three-necked flask equipped with a stirrer, a thermometer, an air duct and a reflux condenser, and nitrogen was introduced for protection. The mixture was stirred for reaction at 25° C. and a stirring rate of 400 r / min for 15 min, and then the mixture was heated to 80° C. and stirred for reaction for 3 h. Then 1.9 g of 2,2-dimethylolpropionic acid was added and stirred for reaction for 1.5 h. Then 2.3 g of a light absorption enhancer was added and stirred for reaction for 3 h. After the reaction was completed, the reaction product was cooled to room temperature, and then placed in a vacuum drying oven and dried at 85° C. for 3 h to obtain a light-absorbing polyurethane. Step S6: weigh 50 parts of light-absorbing polyurethane, 11 parts of aluminum silicate aerogel, 1.1 parts of dispersant, 0.6 parts of wetting and leveling agent, 3 parts of thickener, 0.5 parts of defoamer and 120 parts of deionized water according to weight parts for use; the dispersant is SN-5040 dispersant; the wetting and leveling agent is LW-440 wetting and leveling agent; the thickener is sodium carboxymethyl cellulose; the defoamer is BYK-028 water-based defoamer; Step S7: Add light-absorbing polyurethane, aluminum silicate aerogel, dispersant, wetting and leveling agent, thickener, defoamer and deionized water into a mixer, stir and mix for 3 hours at a temperature of 45° C. and a stirring rate of 400 r / min to obtain thermal insulation material for building exterior walls.

[0026] Comparative Example 1: This comparative example is a method for preparing a thermal insulation material for building exterior walls, comprising the following steps: Step S1: 20 g of polycarbonate diol PCDL1000, 10.5 g of isophorone diisocyanate, 0.02 g of dibutyltin dilaurate and 55 mL of tetrahydrofuran were added to a three-necked flask equipped with a stirrer, a thermometer, an air duct and a reflux condenser, and nitrogen was introduced for protection. The mixture was stirred for reaction at 25° C. and a stirring rate of 400 r / min for 15 min, and then the temperature was raised to 80° C. and the stirring reaction was continued for 3 h. Then 1.9 g of 2,2-dihydroxymethylpropionic acid was added and the stirring reaction was continued for 1.5 h. After the reaction was completed, the reaction product was cooled to room temperature, and then placed in a vacuum drying oven and dried at 85° C. for 3 h to obtain a polyurethane; Step S2: 50 parts of polyurethane, 1.1 parts of dispersant, 0.6 parts of wetting and leveling agent, 3 parts of thickener, 0.5 parts of defoamer and 120 parts of deionized water are weighed according to weight parts and set aside; the dispersant is SN-5040 dispersant; the wetting and leveling agent is LW-440 wetting and leveling agent; the thickener is sodium carboxymethyl cellulose; the defoamer is BYK-028 water-based defoamer; Step S3: Add polyurethane, dispersant, wetting and leveling agent, thickener, defoamer and deionized water into a mixer, stir and mix for 3 hours at a temperature of 45° C. and a stirring rate of 400 r / min to obtain thermal insulation material for building exterior walls.

[0027] Comparative Example 2: This comparative example is a method for preparing a thermal insulation material for building exterior walls, comprising the following steps: Step S1: 10mmol 2,6-dibromophenol and 40mL benzene are added to a three-necked flask equipped with a stirrer, a thermometer and an air guide tube, and nitrogen is introduced for protection. The mixture is stirred for reaction at a temperature of 30°C and a stirring rate of 400r / min for 30min, and then 20mmol 2,4-dihydroxybenzophenone, 25mmol sodium hydroxide and 50mL deionized water are added and the stirring reaction is continued for 30min. The mixture is then heated to 45°C and the stirring reaction is continued for 6h. After the reaction is completed, the reaction product is cooled to room temperature, and then the solvent is removed by rotary evaporation. Then, column chromatography separation and purification are performed using an eluent prepared by mixing ethyl acetate and petroleum ether in a volume ratio of 1:9 to obtain an absorbance enhancer; Step S2: 20 g of polycarbonate diol PCDL1000, 10.5 g of isophorone diisocyanate, 0.02 g of dibutyltin dilaurate and 55 mL of tetrahydrofuran were added to a three-necked flask equipped with a stirrer, a thermometer, an air duct and a reflux condenser, and nitrogen was introduced for protection. The mixture was stirred for reaction at 25° C. and a stirring rate of 400 r / min for 15 min, and then the mixture was heated to 80° C. and stirred for reaction for 3 h. Then 1.9 g of 2,2-dimethylolpropionic acid was added and stirred for reaction for 1.5 h. Then 2.3 g of a light absorption enhancer was added and stirred for reaction for 3 h. After the reaction was completed, the reaction product was cooled to room temperature, and then placed in a vacuum drying oven and dried at 85° C. for 3 h to obtain a light-absorbing polyurethane. Step S3: 50 parts of light-absorbing polyurethane, 1.1 parts of dispersant, 0.6 parts of wetting and leveling agent, 3 parts of thickener, 0.5 parts of defoamer and 120 parts of deionized water are weighed in parts by weight for use; the dispersant is SN-5040 dispersant; the wetting and leveling agent is LW-440 wetting and leveling agent; the thickener is sodium carboxymethyl cellulose; the defoamer is BYK-028 water-based defoamer; Step S4: Add light-absorbing polyurethane, dispersant, wetting and leveling agent, thickener, defoamer and deionized water into a mixer, stir and mix for 3 hours at a temperature of 45° C. and a stirring rate of 400 r / min to obtain thermal insulation material for building exterior walls.

[0028] Comparative Example 3: This comparative example is a method for preparing a thermal insulation material for building exterior walls, comprising the following steps: Step S1: 8 g of aluminum chloride hexahydrate, 50 mL of anhydrous ethanol and 50 mL of deionized water were added to a three-necked flask equipped with a stirrer and a thermometer, and stirred for reaction at a temperature of 30° C. and a stirring rate of 400 r / min for 30 min, and then 12 mmol of propylene oxide was added and the stirring reaction was continued for 3 h to obtain an aluminum-containing solution; Step S2: Add 50 mL of anhydrous ethanol and 50 mL of deionized water into a three-necked flask equipped with a stirrer, a thermometer and a constant pressure dropping funnel, add 8 g of ethyl orthosilicate dropwise while stirring at a temperature of 30° C. and a stirring rate of 400 r / min, and control the dropping rate to 2 drops / s. After the dropwise addition is completed, continue stirring and reacting for 3 hours, and then adjust the pH to 2 with a hydrochloric acid solution with a mass fraction of 15% to obtain a silicon-containing solution; Step S3: Add 50 mL of aluminum-containing solution and 50 mL of silicon-containing solution to a three-necked flask equipped with a stirrer and a thermometer, stir and react for 15 hours at a temperature of 30°C and a stirring rate of 400 r / min, then stand and age for 36 hours, then add 5.5 mL of γ-aminopropyltriethoxysilane and continue stirring and reacting for 3 hours. After the reaction is completed, place the reaction product in a refrigerator, freeze it at a temperature of -20°C for 12 hours, and then place it in a freeze dryer and freeze-dry it at a temperature of -80°C for 30 hours to obtain aluminum silicate aerogel; Step S4: 20 g of polycarbonate diol PCDL1000, 10.5 g of isophorone diisocyanate, 0.02 g of dibutyltin dilaurate and 55 mL of tetrahydrofuran were added to a three-necked flask equipped with a stirrer, a thermometer, an air duct and a reflux condenser, and nitrogen was introduced for protection. The mixture was stirred for reaction at 25° C. and a stirring rate of 400 r / min for 15 min, and then the temperature was raised to 80° C. and the stirring reaction was continued for 3 h. Then 1.9 g of 2,2-dihydroxymethylpropionic acid was added and the stirring reaction was continued for 1.5 h. After the reaction was completed, the reaction product was cooled to room temperature, and then placed in a vacuum drying oven and dried at 85° C. for 3 h to obtain a polyurethane; Step S5: 50 parts of polyurethane, 11 parts of aluminum silicate aerogel, 1.1 parts of dispersant, 0.6 parts of wetting and leveling agent, 3 parts of thickener, 0.5 parts of defoamer and 120 parts of deionized water are weighed according to weight parts for use; the dispersant is SN-5040 dispersant; the wetting and leveling agent is LW-440 wetting and leveling agent; the thickener is sodium carboxymethyl cellulose; the defoamer is BYK-028 water-based defoamer; Step S6: Add polyurethane, aluminum silicate aerogel, dispersant, wetting and leveling agent, thickener, defoamer and deionized water into a mixer, stir and mix for 3 hours at a temperature of 45° C. and a stirring rate of 400 r / min to obtain thermal insulation materials for building exterior walls.

[0029] The thermal insulation materials for building exterior walls of Examples 1-3 and Comparative Examples 1-3 were subjected to performance tests, and the test results are shown in the following table:

[0030] Referring to the data in the above table, based on the comparison between Examples 1-3 and Comparative Examples 1-3, it can be seen that the thermal insulation material for building exterior walls in the present application has excellent thermal insulation performance and can maintain high performance for a long time under lighting conditions.

[0031] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0032] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A thermal insulation material for building exterior walls, characterized in that: It comprises the following components in parts by weight: 40-50 parts of light-absorbing polyurethane, 2-11 parts of aluminum-silicon aerogel, 0.5-1.1 parts of dispersant, 0.3-0.6 parts of wetting and leveling agent, 1-3 parts of thickener, 0.1-0.5 parts of defoamer and 100-120 parts of deionized water; Wherein, the aluminum silicate aerogel is prepared by the following steps: Step a1: adding aluminum chloride hexahydrate, anhydrous ethanol and deionized water into a three-necked flask equipped with a stirrer and a thermometer, stirring the mixture for 20-30 minutes at a temperature of 25-30° C. and a stirring rate of 300-400 r / min, then adding propylene oxide and continuing the stirring reaction for 2-3 hours to obtain an aluminum-containing solution; Step a2: adding anhydrous ethanol and deionized water into a three-necked flask equipped with a stirrer, a thermometer and a constant pressure dropping funnel, adding ethyl orthosilicate dropwise while stirring at a temperature of 25-30°C and a stirring rate of 300-400r / min, controlling the dropping rate to 1-2 drops / s, and continuing to stir and react for 2-3h after the dropwise addition is completed, and then adjusting the pH to 1-2 with a hydrochloric acid solution to obtain a silicon-containing solution; Step a3: Add the aluminum-containing solution and the silicon-containing solution to a three-necked flask equipped with a stirrer and a thermometer, stir and react for 10-15 hours at a temperature of 25-30°C and a stirring rate of 300-400r / min, then let it stand for aging for 24-36 hours, then add γ-aminopropyltriethoxysilane and continue stirring and reacting for 2-3 hours. After the reaction is completed, place the reaction product in a refrigerator, freeze it at a temperature of -20°C for 10-12 hours, and then place it in a freeze dryer and freeze-dry it at a temperature of -80°C for 20-30 hours to obtain aluminum silicate aerogel.

2. A thermal insulation material for building exterior walls according to claim 1, characterized in that: The usage ratio of the aluminum chloride hexahydrate, anhydrous ethanol, deionized water and propylene oxide in step a1 is 2-8 g: 40-50 mL: 40-50 mL: 8-12 mmol.

3. A thermal insulation material for building exterior walls according to claim 1, characterized in that: The usage ratio of the anhydrous ethanol, deionized water and tetraethyl orthosilicate in step a2 is 40-50 mL: 40-50 mL: 2-8 g; the mass fraction of the hydrochloric acid solution is 12-15%.

4. A thermal insulation material for building exterior walls according to claim 1, characterized in that: The aluminum-containing solution, silicon-containing solution and γ-aminopropyltriethoxysilane in step a3 are used in a ratio of 40-50 mL: 40-50 mL: 0.5-5.5 mL.

5. The thermal insulation material for building exterior walls according to claim 1, characterized in that: The light-absorbing polyurethane is prepared by the following steps: Step b1: 2,6-dibromophenol and benzene are added to a three-necked flask equipped with a stirrer, a thermometer and an air guide tube, and nitrogen is introduced for protection. The mixture is stirred for reaction at a temperature of 25-30° C. and a stirring rate of 300-400 r / min for 20-30 min, and then 2,4-dihydroxybenzophenone, sodium hydroxide and deionized water are added and stirred for reaction for 20-30 min. The mixture is then heated to 40-45° C. and stirred for reaction for 5-6 h. After the reaction is completed, the reaction product is cooled to room temperature, and then the solvent is removed by rotary evaporation, and then column chromatography separation and purification are performed with an eluent to obtain a light absorption enhancer; Step b2: Add polycarbonate diol, isophorone diisocyanate, dibutyltin dilaurate and tetrahydrofuran into a three-necked flask equipped with a stirrer, a thermometer, an air duct and a reflux condenser, introduce nitrogen protection, stir and react for 10-15 minutes at a temperature of 20-25°C and a stirring rate of 300-400r / min, then heat to 75-80°C and continue to stir and react for 2-3 hours, then add 2,2-dihydroxymethylpropionic acid and continue to stir and react for 1-1.5 hours, then add a light absorption enhancer and continue to stir and react for 2-3 hours, after the reaction is completed, cool the reaction product to room temperature, then place it in a vacuum drying oven, and dry it at a temperature of 80-85°C for 2-3 hours to obtain a light-absorbing polyurethane.

6. A thermal insulation material for building exterior walls according to claim 5, characterized in that: The amount ratio of the 2,6-dibromophenol, benzene, 2,4-dihydroxybenzophenone, sodium hydroxide and deionized water in step b1 is 10mmol:30-40mL:20mmol:22-25mmol:40-50mL; the eluent is a mixture of ethyl acetate and petroleum ether in a volume ratio of 1:7-9.

7. The thermal insulation material for building exterior walls according to claim 5, characterized in that: The amount ratio of the polycarbonate diol, isophorone diisocyanate, dibutyltin dilaurate, tetrahydrofuran, 2,2-dihydroxymethylpropionic acid and light absorption enhancer in step b2 is 18-20g: 8.5-10.5g: 0.01-0.02g: 50-55mL: 1.5-1.9g: 1.1-2.3g; the polycarbonate diol is PCDL1000.

8. A method for preparing a thermal insulation material for building exterior walls, characterized in that: The following steps are involved: Step 1: Weigh 40-50 parts of light-absorbing polyurethane, 2-11 parts of aluminum silicate aerogel, 0.5-1.1 parts of dispersant, 0.3-0.6 parts of wetting and leveling agent, 1-3 parts of thickener, 0.1-0.5 parts of defoamer and 100-120 parts of deionized water according to weight parts, and set aside; Step 2: Add light-absorbing polyurethane, aluminum silicate aerogel, dispersant, wetting and leveling agent, thickener, defoamer and deionized water into a mixer, stir and mix for 2-3 hours at a temperature of 40-45°C and a stirring rate of 300-400r / min to obtain thermal insulation material for building exterior walls.

9. The method for preparing a thermal insulation material for building exterior walls according to claim 8, characterized in that: The dispersant is SN-5040 dispersant; the wetting and leveling agent is LW-440 wetting and leveling agent; the thickener is sodium carboxymethyl cellulose; and the defoamer is BYK-028 water-based defoamer.

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