Phase change thermal buffer anti-condensation coating and preparation method thereof

Abstract

The present invention relates to the field of anti-condensation coatings, and in particular to a phase-change thermal buffer anti-condensation coating and a preparation method thereof. The phase-change thermal buffer anti-condensation coating provided herein comprises the following components: 10-60 parts of acrylic resin emulsion, 5-50 parts of deionized water, 0.1-5 parts of thickener, 0.2-2 parts of wetting and dispersing agent, 0.1-2 parts of defoaming agent, 0.2-3 parts of film-forming aid, 0.2-3 parts of mildewcide, 1-5 parts of aluminum silicate fiber, and 5-30 parts of thermal buffer phase-change thermal insulation filler. The phase-change thermal buffer anti-condensation coating provided herein has good anti-condensation effect, thermal insulation performance, alkali resistance, and water resistance, and has good application prospects.

Description

Technical Field

[0001] The present invention relates to the field of anti-condensation coatings, and in particular to a phase-change thermal buffer anti-condensation coating and a preparation method thereof. Background Art

[0002] In the basements of large buildings such as museums, exhibition halls, and opera houses in southern my country, condensation forms on the walls and columns during the "return of the south wind" and "plum rain" periods. This is primarily due to the faster heat conduction through the walls and columns than through the air during nighttime cooling. This temperature drops faster than the surrounding air, and combined with the high humidity of the surrounding air, condensation easily forms on the basement surfaces. Due to the large size of basements, active ventilation is ineffective and consumes a lot of energy.

[0003] In recent years, there have been many reports on passive anti-condensation coatings. For example, CN118064020A discloses an anti-condensation coating for pipelines and its preparation method. The coating has good air tightness and is applied to the surface of the pipeline. A small amount can isolate the air from the pipeline and achieve good anti-condensation effect. It is used in hydropower plants, residential and commercial pipelines. Its typical embodiment scenario is a pipeline surface temperature of 8°C, air humidity of 70%, and room temperature of 32°C, which is an anti-condensation scenario with high temperature difference and low humidity. The thickness of the coating in the embodiment is 6-7mm, which is too thick and the cost is too high. It is not suitable for building basements with long-term humidity of 90%.

[0004] CN114958178A discloses a long-lasting anti-condensation coating and its preparation method. This coating offers excellent anti-condensation properties, is resistant to aging, and offers long-lasting results. It is primarily used in switchgear applications. This coating's anti-condensation principle utilizes a high water contact angle and water rolling angle to gradually increase the size of condensed dew before rolling off the substrate surface. However, this does not alter the conditions under which condensation occurs, resulting in the presence of numerous tiny condensation spots on the substrate surface during actual use.

[0005] Anti-condensation coatings for building basements need to take into account both cost and effectiveness. The currently reported coatings cannot meet this application scenario. The development of coatings with good long-term anti-condensation effects under high humidity conditions can fill the gap in the field of anti-condensation in high-humidity building basements and has broad application prospects. Summary of the Invention

[0006] Aiming at the application scenario of anti-condensation in basements of buildings with long-term high humidity under special weather conditions, a phase change thermal buffer anti-condensation coating and its preparation method are now provided. The specific scheme is as follows:

[0007] In a first aspect, a phase change thermal buffer anti-condensation coating is provided, comprising:

[0008] 10-60 parts of acrylic resin emulsion, 5-50 parts of deionized water, 0.1-5 parts of thickener, 0.2-2 parts of wetting and dispersing agent, 0.1-2 parts of defoaming agent, 0.2-3 parts of film-forming aid, 0.2-3 parts of mildewproof agent, 1-5 parts of aluminum silicate fiber and 5-30 parts of thermal buffer phase change insulation filler.

[0009] Specifically, the thermal buffer phase change insulation filler is a thermal buffer phase change microcapsule, and the thermal buffer phase change microcapsule has a double-layer shell material and the double-layer shell materials are connected by chemical bonds; specifically, the double-layer shell material realizes the connection between the polyacrylic acid contained in the inner layer and the silanol contained in the outer layer through hydroxyl groups,

[0010] The core material of the thermal buffer phase change microcapsule is phase change material.

[0011] Specifically, the phase change materials are tetradecane and hexadecane.

[0012] In a second aspect, a method for preparing a phase change thermal buffer anti-condensation coating is provided, comprising the following steps:

[0013] 1) Weigh the acrylic resin emulsion in proportion, add deionized water and thickener, and stir to mix evenly;

[0014] 2) Add wetting and dispersing agent and defoaming agent and stir to mix evenly;

[0015] 3) Add film-forming agent and mildew inhibitor and mix well;

[0016] 4) Add aluminum silicate fiber to accelerate stirring;

[0017] 5) Add the heat buffer phase change insulation filler and stir evenly to obtain the phase change heat buffer anti-condensation coating.

[0018] Specifically, the stirring in steps 1) to 3) and 5) is performed at a low speed, and the stirring in step 4) is performed at a high speed;

[0019] Specifically, the acrylic resin emulsion is selected from at least one of pure acrylic emulsion, silicone acrylic emulsion, styrene acrylic emulsion and acetate acrylic emulsion.

[0020] Specifically, the thickener is selected from at least one of Bentone Lt, EBM8000, Vesmody U605 and Thickener3296.

[0021] Specifically, the wetting and dispersing agent is selected from at least one of OROTAN 731A, HOS 241, and YCK1110.

[0022] Specifically, the defoaming agent is selected from at least one of CK 593, 901W, and BYK 024.

[0023] Specifically, the film-forming aid is selected from at least one of lauryl alcohol ester, propylene glycol methyl ether acetate, dipropylene glycol butyl ether, hexylene glycol butyl ether acetate and ethyl 3-ethoxypropionate.

[0024] Specifically, the mildew inhibitor is at least one selected from 2-octyl-4-isothiazoline-3-one, 3-iodo-2-propynylbutyl butylcarbamate and zinc pyrithione.

[0025] Specifically, the length of the aluminum silicate fiber ranges from 50 to 1000 μm.

[0026] Specifically, the preparation method of the thermal buffer phase change thermal insulation filler includes:

[0027] Step 1: Using phase change material as core material, prepare phase change microcapsules with polyacrylic acid shell material;

[0028] Step 2: hydroxylating the surface of the phase change microcapsules obtained in step 1 with hydroxyethyl acrylate to obtain hydroxylated phase change microcapsules;

[0029] Step 3: using a sol-gel method to coat a layer of silica aerogel shell material on the surface of the hydroxylated phase change microcapsules obtained in step 2 to obtain a thermal buffer phase change insulation filler.

[0030] Specifically, the specific preparation method of the phase change microcapsules in step 1 is:

[0031] A mixture of 30-80 parts of deionized water, 1-10 parts of sodium dodecyl sulfate, 1-4 parts of tetradecane and 1-8 parts of hexadecane is uniformly mixed and heated, and then 1-20 parts of styrene, 1-5 parts of butyl acrylate and 1-15 parts of methyl methacrylate are added and stirred uniformly, followed by slow addition of 0.05-0.5 parts of ammonium persulfate and heating to react, and finally filtering and drying to obtain phase change microcapsules with polyacrylate shell material.

[0032] More specifically, the heating temperature is 40-50°C;

[0033] More specifically, the temperature for the reaction is 70-80°C, and the reaction time is 30-90 minutes;

[0034] Specifically, the specific preparation method of the hydroxylated phase change microcapsules in step 2 is:

[0035] Weigh 30-95 parts of thermal buffer phase change microcapsules, add them to 20-80 parts of isopropanol solvent, then add 0.04-0.5 parts of benzophenone and 2-10 parts of hydroxyethyl acrylate and stir evenly. After drying, irradiate with a high-pressure mercury lamp in a nitrogen atmosphere for 3-10 minutes. Wash the resulting powder with ethanol and dry it to obtain the hydroxylated phase change microcapsules.

[0036] More specifically, the drying temperature is 80-100°C;

[0037] Specifically, the specific preparation method of the thermal buffer phase change thermal insulation filler in step 3 is:

[0038] 10-50 parts of ethanol are added to 20-40 parts of deionized water and mixed evenly, 5-20 parts of ethyl orthosilicate are added thereto and stirred and mixed evenly, sulfonic acid is used to adjust the pH to 3-4 for reaction, and then ethanolamine is used to adjust the pH to 6-7, 10-30 parts of hydroxylated phase change microcapsules are added and stirred evenly and heated for reaction, and then aged at room temperature, and then 5-30 parts of ethanol and 5-20 parts of hexamethyldisiloxane are added for hydrophobic modification, and then solvent replacement is performed. After drying, the thermal buffer phase change insulation filler can be obtained.

[0039] More specifically, drying at 60-80°C for one week;

[0040] More specifically, the reaction time for the reaction is 8-12 h after adjusting the pH to 3-4 with sulfonic acid;

[0041] More specifically, the heating temperature for the reaction is 120-150° C. and the time is 5-10 hours;

[0042] More specifically, the aging time at room temperature is 1-2 days;

[0043] More specifically, the hydrophobic modification conditions are 50-70°C for 10-24h;

[0044] More specifically, the solvent for solvent replacement is n-hexane.

[0045] The present invention prepares phase-change microcapsules by coating a phase-change material with polyacrylic acid, then hydroxylates the surface of the obtained phase-change microcapsules, and then coats them with silica aerogel to prepare thermal buffering phase-change microcapsules with a core material of phase-change material and shell materials of polyacrylic acid and nanoporous aerogel from the inside out. Finally, a phase-change thermal buffering anti-condensation coating is prepared using the thermal buffering phase-change microcapsules as a thermal buffering phase-change thermal insulation filler. The coating has the following beneficial effects:

[0046] (1) The present invention adds heat buffer phase change microcapsules as heat buffer phase change insulation fillers during the process of preparing the coating. Since the phase change material is tightly wrapped by polyacrylic acid and silica aerogel shell materials in sequence, when the substrate begins to cool down rapidly, the outer aerogel shell material with nanopores has excellent thermal insulation properties, which can better prevent the rapid conduction of low temperature and greatly reduce the thermal buffering pressure of the phase change thermal buffer material, greatly improving the thermal buffering time of the phase change material. When the low temperature is transmitted to the phase change material, the phase change material releases heat through phase change to prevent the coating surface temperature from decreasing, thereby effectively preventing the coating surface from rapidly cooling to below the ambient temperature and generating condensation, thereby realizing a double condensation barrier mechanism;

[0047] (2) In the present application, the aerogel insulation material is added in the form of heat buffer phase change microcapsules, instead of the traditional method of directly adding aerogel. Since the phase change of the phase change material releases heat, it can better prevent the nanoporous aerogel from absorbing water, and can better protect the pore structure of the aerogel, thereby exerting better thermal insulation performance; in addition, the aerogel addition method of the present application is better applicable to the coating system of the present application, and can better avoid the problem that when the phase change material and the aerogel are blended in the system, the phase change material with high thermal conductivity is easily connected to each other to form a thermal bridge, thereby causing the low temperature conduction to be too fast and the thermal buffer time to be greatly shortened, and finally the prepared anti-condensation coating has better thermal insulation and anti-condensation effects;

[0048] (3) The present application uses hydroxyethyl acrylate to modify the phase change microcapsules by hydroxylation, thereby introducing hydroxyl groups on the surface of the phase change microcapsules. Then, the silicon hydroxyl groups formed by the sol-gel method can react with the hydroxyl groups introduced on the surface of the phase change microcapsules to achieve chemical bond connection between the inner shell material and the outer shell material, thereby making the aerogel more tightly coated on the surface of the phase change microcapsules; in addition, hydroxyethyl acrylate also introduces acrylic acid segments on the surface of the phase change microcapsules, which can further improve the toughness of the prepared thermal buffer phase change microcapsules and ensure their structural stability; ultimately, the thermal buffer phase change microcapsules prepared in the present application can better avoid structural damage caused by mechanical stirring and other processes during the coating preparation process, thereby better exerting the heat preservation and anti-condensation effects;

[0049] (4) The phase change thermal buffer anti-condensation coating prepared by the method of the present invention also has good water resistance and alkali resistance, can be used in high humidity environments, and has good application potential. DETAILED DESCRIPTION

[0050] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the embodiments of the present invention. Obviously, the embodiments described 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 making any creative efforts shall fall within the scope of protection of the present invention.

[0051] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0052] Example 1

[0053] a. Preparation of thermal buffer phase change insulation filler:

[0054] Step 1: 80 parts of deionized water, 10 parts of sodium dodecyl sulfate, 4 parts of tetradecane, and 8 parts of hexadecane were heated to 50°C and stirred for 10 minutes, 20 parts of styrene, 5 parts of butyl acrylate, and 15 parts of methyl methacrylate were added and stirred evenly, followed by slow addition of 0.5 parts of ammonium persulfate, and the temperature was raised to 80°C. After the reaction for 90 minutes, the phase change microcapsules with polyacrylate shells were obtained after filtration and drying;

[0055] Step 2: Weigh 95 parts of the phase change microcapsules prepared in step 1, add them to 80 parts of isopropanol solvent, then add 0.5 parts of benzophenone and 10 parts of hydroxyethyl acrylate, stir them evenly under ultrasonic stirring, and dry them at 100°C. Then, irradiate the dried powder with a high-pressure mercury lamp in a nitrogen atmosphere for 10 minutes, wash the reacted powder with ethanol, and dry it to prepare surface-grafted phase change microcapsules;

[0056] Step 3: Add 50 parts of ethanol to 40 parts of deionized water, mix evenly, add 20 parts of ethyl orthosilicate, mix and stir evenly, adjust the pH to 3.5 with sulfonic acid, react for 12 hours, adjust the pH to 6.5 with ethanolamine, add 30 parts of modified phase change microcapsules, stir evenly, heat to 150°C, react for 10 hours, lower the temperature to room temperature and age for 2 days, add 30 parts of ethanol and 20 parts of hexamethyldisiloxane, react at 70°C for 24 hours, replace the system solvent with n-hexane, and dry at 80°C for one week to prepare thermal buffer phase change insulation filler.

[0057] b. Preparation of phase change thermal buffer anti-condensation coating:

[0058] 1) Weigh 60 parts of BLJ-8905 acrylic resin emulsion, add 50 parts of deionized water and 5 parts of BENTONE LT thickener, and stir at 300 rpm for 30 minutes;

[0059] 2) Add 2 parts HOS 241 wetting and dispersing agent and 2 parts CK 593 defoamer and stir at 300 rpm for 10 minutes;

[0060] 3) Add 3 parts of alcohol ester dodecanone film-forming aid and 3 parts of 2-octyl-4-isothiazoline-3-one mildew inhibitor and stir at 300 rpm for 10 minutes;

[0061] 4) Add 5 parts of aluminum silicate fiber and stir at 2500 rpm for 30 minutes;

[0062] 5) Add 30 parts of thermal buffer phase change thermal insulation filler and stir at 300 rpm for 30 minutes to prepare the phase change thermal buffer anti-condensation coating.

[0063] Example 2

[0064] a. Preparation of thermal buffer phase change insulation filler:

[0065] Step 1: Heat 55 parts of deionized water, 5 parts of sodium dodecyl sulfate, 2.5 parts of tetradecane, and 4.5 parts of hexadecane to 45°C and stir for 10 minutes. Add 10.5 parts of styrene, 3 parts of butyl acrylate, and 8 parts of methyl methacrylate and stir evenly. Then slowly add 0.25 parts of ammonium persulfate and heat to 75°C. After reacting for 60 minutes, filter and dry to obtain phase change microcapsules with polyacrylate shells.

[0066] Step 2: Weigh 62.5 parts of the phase change microcapsules prepared in step 1, add them to 50 parts of isopropanol solvent, then add 0.25 parts of benzophenone and 6 parts of hydroxyethyl acrylate, stir them evenly under ultrasonic stirring, and dry them at 90°C. Then, irradiate the dried powder with a high-pressure mercury lamp in a nitrogen atmosphere for 6.5 minutes, wash the reacted powder with ethanol, and dry it to prepare surface-grafted phase change microcapsules;

[0067] Step 3: Add 30 parts of ethanol to 30 parts of deionized water, mix evenly, add 12.5 parts of ethyl orthosilicate, mix and stir evenly, adjust the pH to 3 with sulfonic acid, react for 10 hours, adjust the pH to 7 with ethanolamine, add 20 parts of modified phase change microcapsules, stir evenly, heat to 135°C, react for 7.5 hours, lower the temperature to room temperature and age for 1.5 days, add 17.5 parts of ethanol and 12.5 parts of hexamethyldisiloxane, react at 60°C for 17 hours, replace the system solvent with n-hexane, and dry at 70°C for one week to prepare thermal buffer phase change insulation filler.

[0068] b. Preparation of phase change thermal buffer anti-condensation coating:

[0069] 1) Weigh 30 parts of HS-1120 styrene acrylic resin emulsion, add 25 parts of deionized water and 1 part of Nouron EBM8000 thickener, and stir at 300 rpm for 30 minutes;

[0070] 2) Add 1 part FX 600 wetting and dispersing agent and 1 part 901W defoamer and stir at 300 rpm for 10 minutes;

[0071] 3) Add 1.5 parts of dipropylene glycol butyl ether film-forming aid and 1.5 parts of 2-octyl-4-isothiazoline-3-one mildew inhibitor, and stir at 300 rpm for 10 minutes;

[0072] 4) Add 2.5 parts of aluminum silicate fiber and stir at 2500 rpm for 30 minutes;

[0073] 5) Add 18 parts of thermal buffer phase change insulation filler and stir at 300 rpm for 30 minutes to prepare the phase change thermal buffer anti-condensation coating;

[0074] Example 3

[0075] a. Preparation of thermal buffer phase change insulation filler:

[0076] Step 1: 30 parts of deionized water, 1 part of sodium dodecyl sulfate, 1 part of tetradecane, and 1 part of hexadecane were heated to 40°C and stirred for 10 minutes, 1 part of styrene, 1 part of butyl acrylate, and 1 part of methyl methacrylate were added and stirred evenly, followed by slow addition of 0.05 parts of ammonium persulfate, and the temperature was raised to 70°C. After reaction for 30 minutes, the phase change microcapsules with polyacrylate shells were obtained after filtration and drying;

[0077] Step 2: Weigh 30 parts of the phase change microcapsules prepared in step 1, add them to 20 parts of isopropanol solvent, then add 0.2 parts of benzophenone and 2 parts of hydroxyethyl acrylate, stir them evenly under ultrasonic stirring, and dry them at 80°C. Then, irradiate the dried powder with a high-pressure mercury lamp in a nitrogen atmosphere for 3 minutes, wash the reacted powder with ethanol, and dry it to prepare surface-grafted phase change microcapsules;

[0078] Step 3: Add 10 parts of ethanol to 20 parts of deionized water, mix evenly, add 5 parts of ethyl orthosilicate, mix and stir evenly, adjust the pH to 4 with sulfonic acid, react for 8 hours, adjust the pH to 6 with ethanolamine, add 10 parts of modified phase change microcapsules, stir evenly, heat to 120°C, react for 5 hours, lower the temperature to room temperature and age for 1 day, add 5 parts of ethanol and 5 parts of hexamethyldisiloxane, react at 50°C for 10 hours, replace the system solvent with n-hexane, and dry at 60°C for one week to prepare thermal buffer phase change insulation filler.

[0079] b. Preparation of phase change thermal buffer anti-condensation coating:

[0080] 1) Weigh 10 parts of BLJ-8905 acrylic resin, add 5 parts of deionized water and 0.1 parts of BENTONE LT thickener, and stir at 500 rpm for 30 minutes;

[0081] 2) Add 0.2 parts of HOS 241 wetting and dispersing agent and 0.1 parts of CK 593 defoamer and stir at 500 rpm for 10 minutes;

[0082] 3) Add 0.2 parts of alcohol ester dodecanone film-forming aid and 0.2 parts of 2-octyl-4-isothiazoline-3-one mildew inhibitor, and stir at 500 rpm for 10 minutes;

[0083] 4) Add 1 part of aluminum silicate fiber and stir at 2500 rpm for 30 minutes;

[0084] 5) Add 5 parts of thermal buffer phase change insulation filler and stir at 300 rpm for 30 minutes to prepare the phase change thermal buffer anti-condensation coating.

[0085] Comparative Example 1

[0086] Preparation of phase change thermal buffer anti-condensation coating:

[0087] Aerogel powder is added to replace the thermal buffer phase change insulation filler, and other features are the same as those in Example 1.

[0088] Comparative Example 2

[0089] The ultra-microporous nano anti-condensation coating SC180 used in this comparative example is manufactured by Ba Strontium Fluoride New Materials Co., Ltd.

[0090] Comparative Example 3

[0091] a. Preparation of thermal buffer phase change insulation filler:

[0092] Step 1: 30 parts of deionized water, 1 part of sodium dodecyl sulfate, 1 part of tetradecane, and 1 part of hexadecane were heated to 40°C and stirred for 10 minutes, 1 part of styrene, 1 part of butyl acrylate, and 1 part of methyl methacrylate were added and stirred evenly, followed by slow addition of 0.05 parts of ammonium persulfate, and the temperature was raised to 70°C. After reaction for 30 minutes, the phase change microcapsules with polyacrylate shells were obtained after filtration and drying;

[0093] Step 2: Add 10 parts of ethanol to 20 parts of deionized water, mix evenly, add 5 parts of ethyl orthosilicate, mix and stir evenly, adjust the pH to 3.4 with sulfonic acid, react for 8 hours, adjust the pH to 6.5 with ethanolamine, add 10 parts of phase change microcapsules, stir evenly, heat to 120°C, react for 5 hours, lower the temperature to room temperature and age for 1 day, add 5 parts of ethanol and 5 parts of hexamethyldisiloxane, react at 50°C for 10 hours, replace the system solvent with n-hexane, and dry at 60°C for one week to prepare thermal buffer phase change insulation filler.

[0094] b. Preparation of phase change thermal buffer anti-condensation coating:

[0095] The preparation method of the phase-change thermal buffer anti-condensation coating is the same as that of Example 1.

[0096] Comparative Example 4

[0097] a. Preparation of thermal buffer phase change insulation filler:

[0098] Step 1: Heat 80 parts of deionized water, 10 parts of sodium dodecyl sulfate, 4 parts of tetradecane, and 8 parts of hexadecane to 50°C and stir for 10 minutes. Add 20 parts of styrene, 5 parts of butyl acrylate, and 15 parts of methyl methacrylate and stir evenly. Then slowly add 0.5 parts of ammonium persulfate, heat to 80°C, react for 90 minutes, filter, and dry to obtain phase change microcapsules with polyacrylate shells.

[0099] b. Preparation of phase change thermal buffer anti-condensation coating:

[0100] 1) Weigh 60 parts of BLJ-8905 acrylic resin emulsion, add 50 parts of deionized water and 5 parts of BENTONE LT thickener, and stir at 300 rpm for 30 minutes;

[0101] 2) Add 2 parts HOS 241 wetting and dispersing agent and 2 parts CK 593 defoamer and stir at 300 rpm for 10 minutes;

[0102] 3) Add 3 parts of alcohol ester film-forming aid and 3 parts of OIT mildew inhibitor, and stir at 300 rpm for 10 minutes;

[0103] 4) Add 5 parts of aluminum silicate fiber and stir at 2500 rpm for 30 minutes;

[0104] 5) Add 20 parts of thermal buffer phase change insulation filler and 10 parts of aerogel, and stir at 300 rpm for 30 minutes to prepare the phase change thermal buffer anti-condensation coating.

[0105] Comparative Example 5

[0106] Preparation of phase change thermal buffer anti-condensation coating:

[0107] 1) Weigh 60 parts of BLJ-8905 acrylic resin emulsion, add 50 parts of deionized water and 5 parts of BENTONE LT thickener, and stir at 300 rpm for 30 minutes;

[0108] 2) Add 2 parts HOS 241 wetting and dispersing agent and 2 parts CK 593 defoamer and stir at 300 rpm for 10 minutes;

[0109] 3) Add 3 parts of alcohol ester dodecanone film-forming aid and 3 parts of 2-octyl-4-isothiazoline-3-one mildew inhibitor and stir at 300 rpm for 10 minutes;

[0110] 4) Add 5 parts of aluminum silicate fiber and stir at 2500 rpm for 30 minutes;

[0111] 5) Add 10 parts of tetradecane, 20 parts of hexadecane, and 10 parts of aerogel, and stir at 300 rpm for 30 minutes to prepare a phase change thermal buffer anti-condensation coating.

[0112] Comparative Example 6

[0113] a. Preparation of thermal buffer phase change insulation filler:

[0114] Step 1: Heat 80 parts of deionized water, 10 parts of sodium dodecyl sulfate, 4 parts of tetradecane, and 8 parts of hexadecane to 50°C, stir for 10 minutes, add 20 parts of styrene and 5 parts of butyl acrylate and stir evenly, then slowly add 0.5 parts of ammonium persulfate, heat to 80°C, react for 90 minutes, filter, and dry to obtain phase change microcapsules with polyacrylate shells.

[0115] Step 2: Weigh 95 parts of the phase change microcapsules prepared in step 1, add them to 80 parts of isopropanol solvent, then add 0.5 parts of benzophenone and 10 parts of hydroxyethyl acrylate, stir evenly under ultrasonication, and dry at 100°C. Then, irradiate the dried powder with a high-pressure mercury lamp in a nitrogen atmosphere for 10 minutes, wash the reacted powder with ethanol, and dry it to prepare surface-grafted modified phase change microcapsules.

[0116] Step 3: Add 50 parts of ethanol to 40 parts of deionized water, mix evenly, add 20 parts of ethyl orthosilicate, mix and stir evenly, adjust the pH to 3.5 with sulfonic acid, react for 12 hours, adjust the pH to 6.5 with ethanolamine, add 30 parts of modified phase change microcapsules, stir evenly, heat to 150°C, react for 10 hours, lower the temperature to room temperature and age for 2 days, add 30 parts of ethanol and 20 parts of hexamethyldisiloxane, react at 70°C for 24 hours, replace the system solvent with n-hexane, and dry at 80°C for one week to prepare thermal buffer phase change insulation filler.

[0117] b. Preparation of phase change thermal buffer anti-condensation coating:

[0118] The preparation method of the phase change thermal buffer anti-condensation coating is the same as that in Example 1.

[0119] Performance Testing

[0120] The coatings used in the examples and comparative examples were prepared into coating samples and their performance was tested. The test results are shown in Table 1. Thermal insulation performance was measured according to GB 10295-2008 for thermal conductivity of test specimens. Anti-condensation performance was measured using a non-standard method, specifically: testing for three months in a building basement with humidity greater than 90% during the rainy season. Surface condensation was observed, with no condensation being rated as Class A, slight condensation as Class B, and heavy condensation as Class C.

[0121] Table 1

[0122]

[0123] As can be seen from Table 1, the phase-change thermal buffer anti-condensation coating provided by the present invention has excellent anti-condensation performance and thermal insulation performance, as well as good water resistance and alkali resistance, and can be widely used in the field of anti-condensation in basements of high-humidity buildings. Comparative Example 1 uses aerogel as filler to replace the thermal buffer phase-change thermal insulation filler. Since aerogel is hygroscopic and does not have thermal buffering capacity, it cannot resist high humidity environments well, and the anti-condensation effect is relatively poor; Comparative Example 2 uses the existing conventional anti-condensation coating, and the anti-condensation effect is poor; Comparative Example 3 does not perform hydroxylation modification, and directly uses the sol-gel method to coat the aerogel. Since the outer layer of the thermal buffer phase-change microcapsule silica aerogel shell material is easy to fall off and the structure is easy to be destroyed during the mechanical stirring process, the pore structure of the partially fallen aerogel is destroyed after being infiltrated, resulting in relatively poor thermal insulation performance, and at the same time reducing the anti-condensation effect of the prepared coating; Comparative Example 4 performs single-layer coating, and the shell material is polyacrylic acid. The aerogel and phase-change microcapsules are physically blended during the preparation of the coating. Since the aerogel is all added in the form of powder, after being solvent-coated, the aerogel is directly coated. After infiltration, the pore structure is severely damaged, the thermal conductivity is poor, and since the structure of the thermal buffer phase change insulation filler is easily destroyed, the anti-condensation effect is relatively poor; in comparative example 5, the phase change material is not coated and is directly added to the coating. When the phase change material and the aerogel are blended in the system, the phase change material with high thermal conductivity is interconnected to form a thermal bridge, which leads to excessively fast low-temperature conduction and greatly shortens the thermal buffer time, which not only seriously affects the anti-condensation performance, but also reduces the thermal insulation performance, alkali resistance and water resistance; in comparative example 6, when preparing phase change microcapsules of polyacrylic acid shell material, only two monomers are added, and the hard monomer methyl methacrylate is not added. The mechanical properties of the prepared phase change microcapsules are not excellent enough, resulting in the damage of some thermal buffer phase change microcapsules during mechanical mixing, which not only affects the anti-condensation performance, but also affects the thermal insulation performance, water resistance and alkali resistance.

[0124] The above are only some embodiments of the present invention, and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the contents of the present invention specification should be included in the protection scope of the present invention.

Claims

1. A phase change heat buffer anti-condensation coating, characterized in that: Includes the following components: 10-60 parts of acrylic resin emulsion, 5-50 parts of deionized water, 0.1-5 parts of thickener, 0.2-2 parts of wetting and dispersing agent, 0.1-2 parts of defoaming agent, 0.2-3 parts of film-forming aid, 0.2-3 parts of mildewproof agent, 1-5 parts of aluminum silicate fiber and 5-30 parts of thermal buffer phase change thermal insulation filler. The preparation method of the thermal buffer phase change thermal insulation filler comprises: Step 1: Using phase change material as core material, prepare phase change microcapsules with polyacrylic acid shell material; Step 2: hydroxylating the surface of the phase change microcapsules obtained in step 1 with hydroxyethyl acrylate to obtain hydroxylated phase change microcapsules; Step 3: using a sol-gel method to coat a layer of silica aerogel shell material on the surface of the hydroxylated phase change microcapsules obtained in step 2 to obtain a thermal buffer phase change insulation filler.

2. The phase change heat buffer anti-condensation coating according to claim 1, characterized in that: The phase change materials are tetradecane and hexadecane.

3. The method for preparing the phase change heat buffer anti-condensation coating according to claim 1, characterized in that: The following steps are involved: 1) Weigh the acrylic resin emulsion in proportion, add deionized water and thickener, and stir to mix evenly; 2) Add wetting and dispersing agent and defoaming agent and stir to mix evenly; 3) Add film-forming agent and mildew inhibitor and mix well; 4) Add aluminum silicate fiber to accelerate stirring; 5) Add the heat buffer phase change insulation filler and stir evenly to obtain the phase change heat buffer anti-condensation coating.

4. The method for preparing the phase change heat buffer anti-condensation coating according to claim 3, characterized in that: The specific preparation method of the phase change microcapsules in step 1 is: 30-80 parts of deionized water, 1-10 parts of sodium dodecylsulfonate, 1-4 parts of tetradecane and 1-8 parts of hexadecane are mixed evenly and heated, and then 1-20 parts of styrene, 1-5 parts of butyl acrylate and 1-15 parts of methyl methacrylate are added and stirred evenly, followed by slow addition of 0.05-0.5 parts of ammonium persulfate and heating to react, and finally filtering and drying to obtain phase change microcapsules with polyacrylate shell material.

5. The method for preparing the phase change heat buffer anti-condensation coating according to claim 4, characterized in that: The specific preparation method of the hydroxylated phase change microcapsules in step 2 is: 30-95 parts of polyacrylate shell phase change microcapsules are weighed and added to 4-80 parts of isopropanol solvent. 0.04-0.5 parts of benzophenone and 2-10 parts of hydroxyethyl acrylate are then added and stirred evenly. After drying, the mixture is irradiated with a high-pressure mercury lamp in a nitrogen atmosphere for 3-10 minutes. The resulting powder is washed with ethanol and dried to obtain the hydroxylated phase change microcapsules.

6. The method for preparing the phase change heat buffer anti-condensation coating according to claim 3, characterized in that: The specific preparation method of the thermal buffer phase change insulation filler in step 3 is: 10-50 parts of ethanol are added to 20-40 parts of deionized water and mixed evenly, 5-20 parts of ethyl orthosilicate are added thereto and stirred and mixed evenly, sulfonic acid is used to adjust the pH to 3-4 for reaction, ethanolamine is used to adjust the pH to 6-7, 10-30 parts of hydroxylated phase change microcapsules are added and stirred evenly and heated for reaction, and then aged at room temperature, and then 5-30 parts of ethanol and 5-20 parts of hexamethyldisiloxane are added for hydrophobic modification, and solvent replacement is performed, and the thermal buffer phase change insulation filler is obtained after drying.

7. The method for preparing the phase change heat buffer anti-condensation coating according to claim 3, characterized in that: The acrylic resin emulsion is selected from at least one of pure acrylic emulsion, silicone acrylic emulsion, styrene acrylic emulsion and acetate acrylic emulsion.

8. Use of the phase change thermal buffer anti-condensation coating according to any one of claims 1 to 2 in the field of construction.

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