An aerogel anti-condensation dew coating and a method of making the same

Abstract

This invention relates to the field of coating technology, and proposes an aerogel anti-condensation coating and its preparation method. An aerogel anti-condensation coating comprises the following raw materials in parts by weight: 40-60 parts of elastic silicone-acrylic emulsion, 5-7 parts of aerogel, 10-12 parts of polyurethane acrylic resin, 5-10 parts of silica, 5-10 parts of heat-insulating filler, 2-3 parts of film-forming aid, 1-1.5 parts of dispersant, 0.5-1 part of defoamer, 1-2 parts of thickener, and 30-40 parts of water; the heat-insulating filler has a core-shell structure, consisting of a core material and a shell material; the shell material comprises the following raw materials in parts by weight: 9-11 parts of melamine and 7-9 parts of formaldehyde aqueous solution; the core material comprises the following raw materials in parts by weight: 6-8 parts of white oil, 7-9 parts of hexadecane, and 5-7 parts of microcrystalline wax. This technical solution solves the problem of poor heat insulation performance in aerogel anti-condensation coatings in related technologies.

Description

Technical Field

[0001] This invention relates to the field of coating technology, specifically to an aerogel anti-condensation coating and its preparation method. Background Technology

[0002] Aerogel anti-condensation coating is a new type of functional coating made of nano-aerogel as the core functional filler, combined with film-forming resin and additives. It is widely used in scenarios such as building walls, industrial pipelines, cold chain equipment, and energy storage devices where condensation is prone to occur due to temperature differences. It can effectively inhibit water vapor from condensing into dew on the substrate surface.

[0003] However, existing aerogel anti-condensation coatings generally suffer from insufficient thermal insulation performance, leading to their failure in high humidity or alternating temperature environments, and even causing problems such as substrate mold growth, corrosion, and decreased insulation. In practical applications, this not only increases equipment maintenance costs and safety hazards but also fails to meet the practical application requirements of the building and industrial sectors for efficient and durable anti-condensation coatings. Therefore, it is necessary to propose an aerogel anti-condensation coating with good thermal insulation performance and its preparation method. Summary of the Invention

[0004] This invention proposes an aerogel anti-condensation coating and its preparation method, which solves the problem of poor thermal insulation performance of aerogel anti-condensation coatings in related technologies.

[0005] The technical solution of the present invention is as follows: This invention proposes an aerogel anti-condensation coating, comprising the following raw materials in parts by weight: 40-60 parts of elastic silicone-acrylic emulsion, 5-7 parts of aerogel, 10-12 parts of polyurethane acrylic resin, 5-10 parts of silica, 5-10 parts of heat-insulating filler, 2-3 parts of film-forming aid, 1-1.5 parts of dispersant, 0.5-1 part of defoamer, 1-2 parts of thickener, and 30-40 parts of water; The thermal insulation filler has a core-shell structure, consisting of a core material and a shell material; The shell material comprises the following raw materials in parts by weight: 9-11 parts melamine and 7-9 parts formaldehyde aqueous solution; The core material comprises the following raw materials in parts by weight: 6-8 parts white oil, 7-9 parts hexadecane, and 5-7 parts microcrystalline wax.

[0006] As a further technical solution, the formaldehyde in the formaldehyde aqueous solution has a formaldehyde mass fraction of 37%.

[0007] As a further technical solution, the method for preparing the thermal insulation filler includes the following steps: A1. Disperse the formaldehyde aqueous solution and melamine in water, adjust the pH to 8-8.5, mix them, and obtain the shell material prepolymer; A2. Mix white oil, hexadecane, microcrystalline wax, emulsifier, potassium chloride, and water to obtain a core material emulsion; A3. After adding the shell material prepolymer to the core material emulsion for a first mixing, the pH of the system is adjusted to 4-5, and then mixed a second time. After filtration, washing and drying, the heat insulation filler is obtained.

[0008] As a further technical solution, in step A1, the mass ratio of the formaldehyde aqueous solution and melamine to water is 1g:10~15mL.

[0009] As a further technical solution, in step A1, the mixing temperature is 70~75℃ and the time is 1~1.5h.

[0010] As a further technical solution, in step A2, the mass of the emulsifier is 4% to 5% of the sum of the masses of white oil, hexadecane, and microcrystalline wax; the mass of the potassium chloride is 3% to 5% of the sum of the masses of white oil, hexadecane, and microcrystalline wax; and the mass-volume ratio of the sum of the masses of white oil, hexadecane, and microcrystalline wax to water is 1g:8 to 12mL.

[0011] As a further technical solution, in step A2, the mixing temperature is 60~65℃, the mixing speed is 1000~1500r / min, and the mixing time is 25~35min.

[0012] As a further technical solution, in step A3, the temperature of the first mixing is 60~65℃, the rotation speed of the first mixing is 400~600r / min, and the time of the first mixing is 20~25min; the temperature of the second mixing is 70~80℃, and the time of the second mixing is 2~3h.

[0013] As a further technical solution, the polyurethane acrylic resin includes a first polyurethane acrylic resin and a second polyurethane acrylic resin; the first polyurethane acrylic resin and the second polyurethane acrylic resin have different glass transition temperatures.

[0014] As a further technical solution, the glass transition temperature of the first polyurethane acrylic resin is -35°C; the glass transition temperature of the second polyurethane acrylic resin is 15°C.

[0015] As a further technical solution, the mass ratio of the first polyurethane acrylic resin and the second polyurethane acrylic resin is 1~3:1.

[0016] As a further technical solution, the film-forming aid includes one or both of dodecyl alcohol ester and dipropylene glycol methyl ether.

[0017] As a further technical solution, the dispersant is a polyacrylate dispersant.

[0018] As a further technical solution, the defoamer includes one or two of the following: silicone defoamer and mineral oil defoamer.

[0019] As a further technical solution, the thickener includes one or both of thickener RM-8W and thickener RM-2020.

[0020] As a further technical solution, the emulsifier includes one or more of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, and Tween 80.

[0021] The present invention also proposes a method for preparing an aerogel anti-condensation coating, which includes the following steps: mixing the components of the aerogel anti-condensation coating evenly to obtain the aerogel anti-condensation coating.

[0022] The working principle and beneficial effects of this invention are as follows: This invention adds a heat-insulating filler to an aerogel anti-condensation coating. The filler uses melamine-formaldehyde as the shell material and a composite phase change material (PCM) of white oil, hexadecane, and microcrystalline wax as the core material. This significantly improves the coating's heat insulation performance. The filler effectively buffers temperature fluctuations on the substrate surface through phase change energy storage. Its shell material effectively encapsulates and shapes the PCM core material, improving its dispersion stability within the coating. Simultaneously, combined with the nanoporous heat insulation effect of aerogel, a synergistic effect of phase change temperature regulation and porous heat insulation is formed, thereby enhancing the heat insulation performance of the aerogel anti-condensation coating and achieving a highly efficient and long-lasting anti-condensation effect. Detailed Implementation

[0023] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0024] In the following examples and comparative examples, the polyacrylate dispersant is model SN-5040; the silicone defoamer is model BYK-024; the mineral oil defoamer is model SN-154; the elastic silicone-acrylic emulsion is model XR-602; the aerogel is model P100; the silica has a particle size of 30μm; the white oil is model 26#; and the microcrystalline wax is model 70#.

[0025] Example 1 An aerogel anti-condensation coating comprises the following raw materials in parts by weight: 40 parts of elastic silicone-acrylic emulsion, 5 parts of aerogel, 10 parts of polyurethane acrylic resin (glass transition temperature -35℃, model T-7301), 5 parts of silica, 5 parts of heat-insulating filler, 2 parts of dodecyl alcohol ester, 1 part of polyacrylate dispersant, 0.5 parts of silicone defoamer, 1 part of thickener RM-8W, and 30 parts of water; The thermal insulation filler has a core-shell structure, consisting of a core material and a shell material; the preparation method of the thermal insulation filler includes the following steps: A1. Disperse 7 parts of 37wt% formaldehyde aqueous solution and 11 parts of melamine in water, adjust the pH to 8, and mix at 70℃ for 1.5h to obtain shell material prepolymer; the mass ratio of formaldehyde aqueous solution and melamine to water is 1g:10mL. A2. Mix 6 parts white oil, 8 parts hexadecane, 7 parts microcrystalline wax, 0.84 parts sodium dodecyl sulfate, 0.63 parts potassium chloride, and water at 60℃ and 1000 r / min for 35 min to obtain a core material emulsion; the mass-to-volume ratio of the sum of the masses of white oil, hexadecane, and microcrystalline wax to water is 1 g: 8 mL. A3. Add the shell material prepolymer to the core material emulsion, mix for 25 minutes at 60℃ and 400r / min, adjust the pH of the system to 4, mix for 3 hours at 70℃, and finally filter, wash and dry to obtain the heat insulation filler. A method for preparing an aerogel anti-condensation coating includes the following steps: mixing the components of the aerogel anti-condensation coating evenly to obtain the aerogel anti-condensation coating.

[0026] Example 2 An aerogel anti-condensation coating comprises the following raw materials in parts by weight: 50 parts of elastic silicone-acrylic emulsion, 6 parts of aerogel, 11 parts of polyurethane acrylic resin (glass transition temperature -35℃, model T-7301), 8 parts of silica, 7 parts of heat-insulating filler, 2.5 parts of dipropylene glycol methyl ether, 1.2 parts of polyacrylate dispersant, 0.8 parts of mineral oil defoamer, 1.5 parts of thickener RM-2020, and 35 parts of water; The thermal insulation filler has a core-shell structure, consisting of a core material and a shell material; the preparation method of the thermal insulation filler includes the following steps: A1. Disperse 8 parts of 37wt% formaldehyde aqueous solution and 10 parts of melamine in water, adjust the pH to 8.2, and mix at 72℃ for 1.5h to obtain shell material prepolymer; the mass ratio of formaldehyde aqueous solution and melamine to water is 1g:12mL. A2. Mix 8 parts white oil, 7 parts hexadecane, 6 parts microcrystalline wax, 0.9 parts sodium dodecylbenzenesulfonate, 0.85 parts potassium chloride, and water at 62℃ and 1300 r / min for 30 min to obtain a core material emulsion; the mass-to-volume ratio of the sum of the masses of white oil, hexadecane, and microcrystalline wax to water is 1 g: 10 mL. A3. Add the shell material prepolymer to the core material emulsion and mix for 22 minutes at 63℃ and 500 r / min. Adjust the pH of the system to 4.5 and mix for 2.5 hours at 75℃. Finally, filter, wash and dry to obtain the thermal insulation filler. A method for preparing an aerogel anti-condensation coating includes the following steps: mixing the components of the aerogel anti-condensation coating evenly to obtain the aerogel anti-condensation coating.

[0027] Example 3 An aerogel anti-condensation coating comprises the following raw materials in parts by weight: 60 parts of elastic silicone-acrylic emulsion, 7 parts of aerogel, 12 parts of polyurethane acrylic resin (glass transition temperature -35℃, model T-7301), 10 parts of silica, 10 parts of heat-insulating filler, 3 parts of dipropylene glycol methyl ether, 1.5 parts of polyacrylate dispersant, 1 part of mineral oil defoamer, 2 parts of thickener RM-2020, and 40 parts of water; The thermal insulation filler has a core-shell structure, consisting of a core material and a shell material; the preparation method of the thermal insulation filler includes the following steps: A1. Disperse 9 parts of 37wt% formaldehyde aqueous solution and 9 parts of melamine in water, adjust the pH to 8.5, and mix at 75℃ for 1 hour to obtain shell material prepolymer; the mass ratio of formaldehyde aqueous solution and melamine to water is 1g:15mL. A2. Mix 7 parts white oil, 9 parts hexadecane, 5 parts microcrystalline wax, 1.05 parts Tween 80, 1.05 parts potassium chloride, and water at 65℃ and 1500 r / min for 25 min to obtain a core material emulsion; the mass-to-volume ratio of the sum of the masses of white oil, hexadecane, and microcrystalline wax to water is 1 g: 12 mL. A3. Add the shell material prepolymer to the core material emulsion, mix for 20 minutes at 65℃ and 600r / min, adjust the pH of the system to 5, mix for 2 hours at 80℃, and finally filter, wash and dry to obtain the heat insulation filler. A method for preparing an aerogel anti-condensation coating includes the following steps: mixing the components of the aerogel anti-condensation coating evenly to obtain the aerogel anti-condensation coating.

[0028] Example 4 Compared with Example 1, the only difference in this example is that the polyurethane acrylic resin in this example is composed of a first polyurethane acrylic resin (glass transition temperature of -35°C, model T-7301) and a second polyurethane acrylic resin (glass transition temperature of 15°C, model T-7110) in a mass ratio of 1:1.

[0029] Example 5 Compared with Example 1, the only difference in this example is that the polyurethane acrylic resin in this example is composed of a first polyurethane acrylic resin (glass transition temperature of -35°C, model T-7301) and a second polyurethane acrylic resin (glass transition temperature of 15°C, model T-7110) in a mass ratio of 2:1.

[0030] Example 6 Compared with Example 1, the only difference in this example is that the polyurethane acrylic resin in this example is composed of a first polyurethane acrylic resin (glass transition temperature of -35°C, model T-7301) and a second polyurethane acrylic resin (glass transition temperature of 15°C, model T-7110) in a mass ratio of 3:1.

[0031] Example 7 Compared with Example 1, the only difference in this example is that the glass transition temperature of the polyurethane acrylic resin in this example is 15°C, and the type is T-7110.

[0032] Comparative Example 1 Compared with Example 1, the only difference in this comparative example is that the preparation method of the thermal insulation filler in this comparative example includes the following steps: A1. Disperse 7 parts of 37wt% formaldehyde aqueous solution and 11 parts of melamine in water, adjust the pH to 8, and mix at 70℃ for 1.5h to obtain shell material prepolymer; the mass ratio of formaldehyde aqueous solution and melamine to water is 1g:10mL. A2. Mix 21 parts hexadecane, 0.84 parts sodium dodecyl sulfate, 0.63 parts potassium chloride, and water at 60℃ and 1000 r / min for 35 min to obtain a core material emulsion; the mass-volume ratio of the sum of the masses of white oil, hexadecane, and microcrystalline wax to water is 1 g: 8 mL. A3. Add the shell prepolymer to the core emulsion and mix for 25 minutes at 60°C and 400 r / min. Adjust the pH of the system to 4 and mix for 3 hours at 70°C. Finally, filter, wash and dry to obtain the thermal insulation filler.

[0033] Comparative Example 2 Compared with Example 1, the only difference in this comparative example is that the preparation method of the thermal insulation filler in this comparative example includes the following steps: A1. Disperse 7 parts of 37wt% formaldehyde aqueous solution and 11 parts of melamine in water, adjust the pH to 8, and mix at 70℃ for 1.5h to obtain shell material prepolymer; the mass ratio of formaldehyde aqueous solution and melamine to water is 1g:10mL. A2. Mix 9 parts white oil, 12 parts hexadecane, 0.84 parts sodium dodecyl sulfate, 0.63 parts potassium chloride, and water at 60℃ and 1000 r / min for 35 min to obtain a core material emulsion; the mass-volume ratio of the sum of the masses of white oil, hexadecane, and microcrystalline wax to water is 1 g: 8 mL. A3. Add the shell prepolymer to the core emulsion and mix for 25 minutes at 60°C and 400 r / min. Adjust the pH of the system to 4 and mix for 3 hours at 70°C. Finally, filter, wash and dry to obtain the thermal insulation filler.

[0034] Comparative Example 3 Compared with Example 1, the only difference in this comparative example is that the preparation method of the thermal insulation filler in this comparative example includes the following steps: A1. Disperse 7 parts of 37wt% formaldehyde aqueous solution and 11 parts of melamine in water, adjust the pH to 8, and mix at 70℃ for 1.5h to obtain shell material prepolymer; the mass ratio of formaldehyde aqueous solution and melamine to water is 1g:10mL. A2. Mix 11.2 parts hexadecane, 9.8 parts microcrystalline wax, 0.84 parts sodium dodecyl sulfate, 0.63 parts potassium chloride, and water at 60℃ and 1000 r / min for 35 min to obtain a core material emulsion; the mass-to-volume ratio of the sum of the masses of white oil, hexadecane, and microcrystalline wax to water is 1 g: 8 mL. A3. Add the shell prepolymer to the core emulsion and mix for 25 minutes at 60°C and 400 r / min. Adjust the pH of the system to 4 and mix for 3 hours at 70°C. Finally, filter, wash and dry to obtain the thermal insulation filler.

[0035] Experimental Example 1 The aerogel anti-condensation coatings prepared in Examples 1-3 and Comparative Examples 1-3 were sprayed onto the outer wall of an iron drum, with a dry film thickness of 3 mm. After the coating was completely dry, an ice-water mixture was placed inside the iron drum, and the temperature was adjusted to 5-7°C. The drum lid was then closed. The room temperature was adjusted to 20-25°C to maintain a temperature difference of approximately 15-18°C between the temperature inside the drum and the ambient temperature. The relative humidity was adjusted to 90%. Condensation was then observed on the outer wall of the iron drum. The test results are shown in Table 1. Table 1 Test results of the anti-condensation performance of aerogel anti-condensation coatings

[0036] The results in Table 1 show that the aerogel anti-condensation coating prepared by the present invention has good anti-condensation performance.

[0037] Experiment Example 2 The aerogel anti-condensation coatings prepared in Examples 1-3 and Comparative Examples 1-3 were tested according to the test methods specified in standard GB / T10295-2008 "Determination of Steady-State Thermal Resistance and Related Properties of Thermal Insulation Materials - Heat Flow Meter Method". The results are shown in Table 2. Table 2. Thermal conductivity test results of aerogel anti-condensation coating

[0038] The results in Table 2 show that the aerogel anti-condensation coating prepared by the present invention has good thermal insulation performance.

[0039] Experimental Example 3 The aerogel anti-condensation coatings prepared in Examples 1, 4-7 were tested for moisture absorption using the method disclosed in Chinese Patent Document CN111089820A. The test results are shown in Table 3. Table 3. Test results of moisture absorption rate of aerogel anti-condensation coating

[0040] As shown in Table 3, the aerogel anti-condensation coating prepared by this invention has good moisture absorption properties.

[0041] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An aerogel anti-condensation coating, characterized in that, The raw materials include the following components by weight: 40-60 parts of elastic silicone-acrylic emulsion, 5-7 parts of aerogel, 10-12 parts of polyurethane acrylic resin, 5-10 parts of silica, 5-10 parts of heat-insulating filler, 2-3 parts of film-forming aid, 1-1.5 parts of dispersant, 0.5-1 part of defoamer, 1-2 parts of thickener, and 30-40 parts of water; The thermal insulation filler has a core-shell structure, consisting of a core material and a shell material; The shell material comprises the following raw materials in parts by weight: 9-11 parts melamine and 7-9 parts formaldehyde aqueous solution; The core material comprises the following raw materials in parts by weight: 6-8 parts white oil, 7-9 parts hexadecane, and 5-7 parts microcrystalline wax.

2. The aerogel anti-condensation coating according to claim 1, characterized in that, The method for preparing the thermal insulation filler includes the following steps: A1. Disperse the formaldehyde aqueous solution and melamine in water, adjust the pH to 8-8.5, mix them, and obtain the shell material prepolymer; A2. Mix white oil, hexadecane, microcrystalline wax, emulsifier, potassium chloride, and water to obtain a core material emulsion; A3. After adding the shell material prepolymer to the core material emulsion for a first mixing, the pH of the system is adjusted to 4-5, and then mixed a second time. After filtration, washing and drying, the heat insulation filler is obtained.

3. The aerogel anti-condensation coating according to claim 2, characterized in that, In step A1, the mixing temperature is 70~75℃ and the time is 1~1.5h.

4. The aerogel anti-condensation coating according to claim 2, characterized in that, In step A2, the mixing temperature is 60~65℃, the mixing speed is 1000~1500r / min, and the mixing time is 25~35min.

5. The aerogel anti-condensation coating according to claim 2, characterized in that, In step A3, the temperature of the first mixing is 60~65℃, the rotation speed of the first mixing is 400~600r / min, and the time of the first mixing is 20~25min; the temperature of the second mixing is 70~80℃, and the time of the second mixing is 2~3h.

6. The aerogel anti-condensation coating according to claim 1, characterized in that, The polyurethane acrylate resin includes a first polyurethane acrylate resin and a second polyurethane acrylate resin; the first polyurethane acrylate resin and the second polyurethane acrylate resin have different glass transition temperatures.

7. The aerogel anti-condensation coating according to claim 6, characterized in that, The glass transition temperature of the first polyurethane acrylic resin is -35°C; the glass transition temperature of the second polyurethane acrylic resin is 15°C.

8. The aerogel anti-condensation coating according to claim 7, characterized in that, The mass ratio of the first polyurethane acrylic resin to the second polyurethane acrylic resin is 1~3:

1.

9. The aerogel anti-condensation coating according to claim 1, characterized in that, The film-forming aid includes one or both of dodecyl alcohol ester and dipropylene glycol methyl ether.

10. A method for preparing an aerogel anti-condensation coating, used to prepare an aerogel anti-condensation coating as described in any one of claims 1 to 9, characterized in that, Includes the following steps: After the components of the aerogel anti-condensation coating are mixed evenly, the aerogel anti-condensation coating is obtained.

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