Coating for external wall thermal insulation and preparation method thereof

Abstract

The invention relates to the technical field of building energy-saving materials, and discloses a coating for external wall insulation and a preparation method thereof. A coating for external wall heat preservation comprises a base layer bonding layer, a core heat preservation layer and a surface protection layer which are sequentially overlaid. The preparation method of the coating comprises the following steps: S1, preparing the modified glass beads; s2, preparing base layer bonding layer slurry; s3, core thermal insulation layer slurry is prepared; s4, preparing surface protective layer slurry; s5, coating forming; and S6, finished product detection. By adopting the technical scheme of synergism of preparation of modified vitrified micro beads and staged stirring of each layer of slurry, the technical effects of improving the compatibility of raw materials, optimizing the internal structure of the coating and enhancing the comprehensive performance of the coating are achieved, and the problems that the raw materials are not uniformly mixed, the coating is prone to caking and layering, and the structural stability is poor are solved.

Description

Technical Field

[0001] This invention relates to the field of building energy-saving materials technology, specifically to a coating for external wall insulation and its preparation method. Background Technology

[0002] Exterior wall insulation coatings are one of the core materials in the field of building energy conservation. Primarily applied to the surface of building exterior walls, they achieve thermal insulation and wall protection through a layered structural design. This effectively reduces building energy consumption, improves building comfort, protects the exterior wall structure, and extends the building's lifespan. These coatings typically consist of a base bonding layer, a core insulation layer, and a surface protective layer. The compatibility of raw materials and the preparation process of each layer directly determine the overall performance of the coating. Vitrified microspheres, as the core insulation material, have their modification effect and the uniformity of mixing with other raw materials being key factors affecting the coating's insulation and structural stability. They are widely used in various scenarios, including civil buildings, industrial buildings, and high-rise buildings.

[0003] Currently, in the preparation of coatings for exterior wall insulation, most existing technologies do not perform standardized modification treatment on vitrified microspheres, or although modification is performed, key process details are not controlled. At the same time, when preparing each layer of slurry, a single stirring method is often used, without designing a staged stirring process according to the characteristics of the raw materials.

[0004] This results in poor compatibility between vitrified microspheres and other raw materials such as water-based acrylic emulsion and basalt short fibers, leading to uneven mixing of the slurry. Consequently, the prepared exterior wall insulation coating is prone to clumping and delamination, with a loose internal structure and insufficient structural stability. This makes it unable to meet the long-term requirements for building exterior wall insulation and protection, thus limiting the application range of the coating. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a coating for external wall insulation and its preparation method, which solves the problems of uneven mixing of raw materials, easy agglomeration and delamination of coatings, and poor structural stability caused by the lack of standardized modification of vitrified microspheres or the use of a single stirring method in existing technologies.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a coating for exterior wall insulation, comprising a base bonding layer, a core insulation layer, and a surface protective layer, wherein the base bonding layer, the core insulation layer, and the surface protective layer are stacked sequentially.

[0007] The core insulation layer comprises the following raw materials in parts by weight: 15-25 parts modified vitrified microspheres, 20-30 parts water-based acrylic emulsion, 8-15 parts expanded perlite, 3-8 parts basalt short fibers, 1-3 parts silane coupling agent, 0.5-2 parts thickener, 0.3-1 part defoamer, 1-2 parts antifreeze, and 15-25 parts deionized water.

[0008] Preferably, the base bonding layer comprises the following raw materials in parts by weight: 30-40 parts silicate cement, 10-15 parts acrylic resin, 15-20 parts quartz sand, 0.5-1.5 parts silane coupling agent, and 10-15 parts deionized water;

[0009] The surface protective layer comprises the following raw materials in parts by weight: 15-25 parts fluorocarbon emulsion, 5-10 parts titanium dioxide, 3-6 parts talc, 0.5-1.5 parts UV stabilizer, 1-2 parts film-forming agent, and 10-20 parts deionized water.

[0010] Preferably, in the core insulation layer, the mass ratio of modified vitrified microspheres to expanded perlite is 1.5-2.5:1.

[0011] Preferably, the basalt short fibers have a chopped length of 1-5 mm and are pretreated with silane coupling agent KH560; the thickener is hydroxypropyl methylcellulose, the defoamer is an organosilicon defoamer, the antifreeze agent is ethylene glycol, and the film-forming agent is polyethylene glycol.

[0012] Preferably, the quartz sand is a mixture of 20-30 mesh and 40-60 mesh in a mass ratio of 1:2-3, and is dried at 60-80℃ to a moisture content of ≤5%; the titanium dioxide is rutile titanium dioxide, and the talc powder has a particle size of 100-120 mesh.

[0013] A method for preparing an exterior wall insulation coating includes the following steps:

[0014] S1. Preparation of modified vitrified microspheres: After drying the vitrified microspheres, they are immersed in a modification solution prepared by aqueous acrylic emulsion, deionized water and γ-methacryloyloxypropyltrimethoxysilane. After immersion, they are dried again to obtain modified vitrified microspheres.

[0015] S2. Preparation of base bonding layer slurry: Take silicate cement, acrylic resin, quartz sand, silane coupling agent and deionized water. First, mix silicate cement and quartz sand, then add the remaining raw materials and continue mixing to obtain base bonding layer slurry.

[0016] S3. Preparation of core insulation layer slurry: Take the modified vitrified microspheres, water-based acrylic emulsion, expanded perlite, basalt short fibers, silane coupling agent, thickener, defoamer, antifreeze agent and deionized water prepared in S1. First, mix and stir the modified vitrified microspheres, expanded perlite and basalt short fibers. Then, add the water-based acrylic emulsion, silane coupling agent and the remaining raw materials in sequence and stir in stages to obtain the core insulation layer slurry.

[0017] S4. Preparation of surface protective layer slurry: Take fluorocarbon emulsion, titanium dioxide, talc, UV stabilizer, film-forming agent and deionized water. First, mix and stir the titanium dioxide and talc, then add the remaining raw materials and continue stirring to obtain the surface protective layer slurry.

[0018] S5. Coating Forming: First, clean and grind the base layer of the building's exterior wall. Then, apply the slurry prepared in S2-S4 in layers. After each layer is completed, allow it to cure naturally. After all construction and curing are completed, the coating for exterior wall insulation is obtained.

[0019] S6. Finished Product Inspection: The performance of the exterior wall insulation coating formed in S5 is tested. If the test is passed, it is considered a finished product. If the test is failed, the corresponding preparation step is returned to be re-prepared, and the test is conducted again after re-preparation.

[0020] Preferably, in step S1, the vitrified microspheres are dried at a temperature of 105-110°C, dried to constant weight, cooled to room temperature, and then soaked.

[0021] The soaking time of the modified solution is 2-4 hours, and the drying temperature after soaking is 80-90℃, and the drying time is 1-2 hours.

[0022] The mass ratio of vitrified microspheres, aqueous acrylic emulsion, deionized water, and γ-methacryloyloxypropyltrimethoxysilane is 1:0.4-0.6:0.4-0.6:0.005-0.01.

[0023] Preferably, in step S2, the quartz sand needs to be dried at 60-80℃ beforehand to a moisture content of ≤5%;

[0024] The mixing process is divided into two stages. The first stage is low-speed mixing, with a speed of 300-500 r / min and a mixing time of 10-15 min. The second stage is high-speed mixing, with a speed of 800-1000 r / min and a mixing time of 20-30 min.

[0025] In step S3, the basalt short fibers need to be pretreated with silane coupling agent KH560 in advance;

[0026] The mixing process is divided into three stages: the first stage is low-speed mixing, with a speed of 300-400 r / min and a mixing time of 5-10 min; the second stage is medium-speed mixing, with a speed of 600-800 r / min and a mixing time of 15-20 min; and the third stage is high-speed mixing, with a speed of 900-1100 r / min and a mixing time of 25-35 min.

[0027] Preferably, in step S4, titanium dioxide and talc need to be pulverized and sieved in advance; the stirring is divided into three stages: the first stage is low-speed stirring, with a rotation speed of 300-400 r / min and a stirring time of 8-12 min; the second stage is medium-speed stirring, with a rotation speed of 500-700 r / min and a stirring time of 15-20 min; and the third stage is high-speed stirring, with a rotation speed of 800-1000 r / min and a stirring time of 10-15 min.

[0028] Preferably, in step S5, the base layer is cleaned and sanded to ensure that there is no floating dust, oil stains, or hollow areas; the base layer bonding layer is applied by brushing, the surface protective layer is applied by brushing, and the core insulation layer is applied by spraying. During spraying, the spray gun is kept perpendicular to the wall and the moving speed is uniform.

[0029] The construction environment temperature is 5-35℃, and the relative humidity is ≤80%. Avoid rain and direct sunlight during construction. The curing environment temperature is 10-30℃, and the relative humidity is ≥50%. Avoid collisions and friction on the coating surface during the curing period.

[0030] The thickness of the base bonding layer is 0.5-1mm, and the curing time is 24-48h; the thickness of the core insulation layer is 5-8mm, and the curing time is 48-72h; the thickness of the surface protective layer is 0.3-0.5mm, and the curing time is 24-36h.

[0031] This invention provides a coating for external wall insulation and its preparation method. It has the following beneficial effects:

[0032] 1. This invention achieves the technical effects of improving raw material compatibility, optimizing the internal structure of the coating, and enhancing the overall performance of the coating by adopting a technical solution of preparing modified vitrified microspheres and staged stirring of each layer of slurry. Compared with the existing technology that does not perform standardized modification of vitrified microspheres or adopts a single stirring method, this invention solves the problems of uneven mixing of raw materials, easy agglomeration and delamination of the coating, and poor structural stability.

[0033] 2. The present invention adopts a technical solution of layered preparation, layered construction and layered curing of the base bonding layer, core insulation layer and surface protective layer. This achieves the technical effect of ensuring tight bonding of each coating layer and realizing multiple functions of heat preservation, crack resistance and weather resistance. Compared with the existing technical solutions that do not construct in layers or omit the curing steps, this invention solves the problems of easy delamination and peeling of the coating, short service life and inability to meet multiple use requirements.

[0034] 3. This invention adopts a synergistic technical solution that combines key raw material pretreatment, multi-stage impurity removal optimization, and finished product testing. This achieves the technical effects of improving coating forming quality, ensuring stable product performance, and facilitating large-scale production. Compared with existing technologies that lack raw material pretreatment or have incomplete testing processes, this invention solves the problems of low coating purity, large performance fluctuations, low production efficiency, and difficulty in achieving large-scale mass production. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the steps in preparing a coating for external wall insulation according to the present invention. Detailed Implementation

[0036] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. 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 skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] This invention provides a coating for external wall insulation, comprising a base bonding layer, a core insulation layer, and a surface protective layer, wherein the base bonding layer, the core insulation layer, and the surface protective layer are stacked sequentially.

[0038] The core insulation layer comprises the following raw materials in parts by weight: 15-25 parts modified vitrified microspheres, 20-30 parts water-based acrylic emulsion, 8-15 parts expanded perlite, 3-8 parts basalt short fibers, 1-3 parts silane coupling agent, 0.5-2 parts thickener, 0.3-1 part defoamer, 1-2 parts antifreeze, and 15-25 parts deionized water.

[0039] The base bonding layer comprises the following raw materials in parts by weight: 30-40 parts silicate cement, 10-15 parts acrylic resin, 15-20 parts quartz sand, 0.5-1.5 parts silane coupling agent, and 10-15 parts deionized water;

[0040] The surface protective layer comprises the following raw materials in parts by weight: 15-25 parts fluorocarbon emulsion, 5-10 parts titanium dioxide, 3-6 parts talc, 0.5-1.5 parts UV stabilizer, 1-2 parts film-forming agent, and 10-20 parts deionized water.

[0041] In the core insulation layer, the mass ratio of modified vitrified microspheres to expanded perlite is 1.5-2.5:1.

[0042] The basalt short fibers have a chopped length of 1-5 mm and are pretreated with silane coupling agent KH560; the thickener is hydroxypropyl methylcellulose, the defoamer is an organosilicon defoamer, the antifreeze agent is ethylene glycol, and the film-forming agent is polyethylene glycol.

[0043] The quartz sand is a mixture of 20-30 mesh and 40-60 mesh in a mass ratio of 1:2-3, and is dried at 60-80℃ until the moisture content is ≤5%; the titanium dioxide is rutile titanium dioxide, and the talc has a particle size of 100-120 mesh.

[0044] Please see the appendix Figure 1 A method for preparing an exterior wall insulation coating includes the following steps:

[0045] S1. Preparation of modified vitrified microspheres: After drying the vitrified microspheres, they are immersed in a modification solution prepared by aqueous acrylic emulsion, deionized water and γ-methacryloyloxypropyltrimethoxysilane. After immersion, they are dried again to obtain modified vitrified microspheres.

[0046] In S1, the vitrified microspheres are dried at 105-110℃, dried to constant weight, cooled to room temperature, and then soaked.

[0047] The soaking time of the modified solution is 2-4 hours, and the drying temperature after soaking is 80-90℃, and the drying time is 1-2 hours.

[0048] The mass ratio of vitrified microspheres, aqueous acrylic emulsion, deionized water, and γ-methacryloyloxypropyltrimethoxysilane is 1:0.4-0.6:0.4-0.6:0.005-0.01;

[0049] Specifically, a constant temperature stirring device should be used when preparing the modified solution, controlling the stirring temperature at 25±2℃, the stirring speed at 200r / min, and the stirring time at 30min to ensure that all components of the modified solution are uniformly mixed and free of sediment. During the soaking process, the modified solution should be gently stirred once every 30min to prevent the vitrified microspheres from accumulating at the bottom of the container and to ensure that each vitrified microsphere can fully contact the modified solution, thereby improving the uniformity of modification. The secondary drying adopts a segmented drying method, first preheating at 50℃ for 30min, and then gradually increasing the temperature to 80-90℃ to avoid the surface of the vitrified microspheres cracking due to a sudden temperature rise.

[0050] S2. Preparation of base bonding layer slurry: Take silicate cement, acrylic resin, quartz sand, silane coupling agent and deionized water. First, mix silicate cement and quartz sand, then add the remaining raw materials and continue mixing to obtain base bonding layer slurry.

[0051] In S2, the quartz sand needs to be dried at 60-80℃ in advance until the moisture content is ≤5%;

[0052] The mixing process is divided into two stages. The first stage is low-speed mixing, with a speed of 300-500 r / min and a mixing time of 10-15 min. The second stage is high-speed mixing, with a speed of 800-1000 r / min and a mixing time of 20-30 min.

[0053] Specifically, after drying, the quartz sand needs to be screened to remove impurity particles larger than 60 mesh, ensuring uniform quartz sand particles and improving the bonding with silicate cement. When stirring at low speed, use a clockwise stirring direction, and switch to a counterclockwise stirring direction when stirring at high speed. Alternate between the two stirring directions to reduce slurry agglomeration. The silane coupling agent needs to be diluted 5 times with deionized water in advance and then slowly added drop by drop, with the dropping rate controlled at 1-2 drops / second to avoid excessive local concentration that could cause slurry clumping.

[0054] S3. Preparation of core insulation layer slurry: Take the modified vitrified microspheres, water-based acrylic emulsion, expanded perlite, basalt short fibers, silane coupling agent, thickener, defoamer, antifreeze agent and deionized water prepared in S1. First, mix and stir the modified vitrified microspheres, expanded perlite and basalt short fibers. Then, add the water-based acrylic emulsion, silane coupling agent and the remaining raw materials in sequence and stir in stages to obtain the core insulation layer slurry.

[0055] In S3, basalt short fibers need to be pretreated with silane coupling agent KH560 in advance;

[0056] The mixing process is divided into three stages: the first stage is low-speed mixing, with a speed of 300-400 r / min and a mixing time of 5-10 min; the second stage is medium-speed mixing, with a speed of 600-800 r / min and a mixing time of 15-20 min; and the third stage is high-speed mixing, with a speed of 900-1100 r / min and a mixing time of 25-35 min.

[0057] Specifically, during the pretreatment of basalt short fibers, they are immersed in a silane coupling agent KH560 solution for 1 hour, then removed and air-dried naturally until there is no obvious liquid accumulation on the surface. The pretreated short fibers must be used within 24 hours to avoid failure. Expanded perlite needs to be dried at 100℃ for 1 hour in advance to remove moisture from the internal pores and prevent air bubbles from forming in the slurry. Thickener and defoamer need to be added separately. Thickener is first evenly sprinkled in powder form, stirred for 5 minutes, and then defoamer is added to avoid mutual interference and reduced performance.

[0058] S4. Preparation of surface protective layer slurry: Take fluorocarbon emulsion, titanium dioxide, talc, UV stabilizer, film-forming agent and deionized water. First, mix and stir the titanium dioxide and talc, then add the remaining raw materials and continue stirring to obtain the surface protective layer slurry.

[0059] In S4, titanium dioxide and talc need to be pulverized and sieved in advance; the mixing is divided into three stages: the first stage is low-speed mixing, with a speed of 300-400 r / min and a mixing time of 8-12 min; the second stage is medium-speed mixing, with a speed of 500-700 r / min and a mixing time of 15-20 min; the third stage is high-speed mixing, with a speed of 800-1000 r / min and a mixing time of 10-15 min.

[0060] Specifically, titanium dioxide and talc are pulverized and passed through a 120-mesh sieve to ensure fine powder without lumps, thereby improving the uniformity of the slurry and the smoothness of the surface protective layer. The UV stabilizer is added in batches, with half of the UV stabilizer added after stirring at medium speed for 10 minutes and the remaining half added at the beginning of high-speed stirring to enhance the dispersibility of the UV stabilizer in the slurry. The film-forming agent needs to be preheated to 40°C to melt and then cooled to room temperature before being added to the slurry to avoid high temperature damaging the stability of the fluorocarbon emulsion.

[0061] S5. Coating Forming: First, clean and grind the base layer of the building's exterior wall. Then, apply the slurry prepared in S2-S4 in layers. After each layer is completed, allow it to cure naturally. After all construction and curing are completed, the coating for exterior wall insulation is obtained.

[0062] In S5, the base layer is cleaned and sanded to ensure that there is no floating dust, oil stains, or hollow areas. The base bonding layer is applied by brushing, the surface protective layer is applied by brushing, and the core insulation layer is applied by spraying. When spraying, the spray gun is kept perpendicular to the wall and the movement speed is uniform.

[0063] The construction environment temperature is 5-35℃, and the relative humidity is ≤80%. Avoid rain and direct sunlight during construction. The curing environment temperature is 10-30℃, and the relative humidity is ≥50%. Avoid collisions and friction on the coating surface during the curing period.

[0064] The thickness of the base bonding layer is 0.5-1mm, and the curing time is 24-48h; the thickness of the core insulation layer is 5-8mm, and the curing time is 48-72h; the thickness of the surface protective layer is 0.3-0.5mm, and the curing time is 24-36h.

[0065] Specifically, after cleaning the base layer, a high-pressure air gun should be used to blow away surface dust. Sanding should be done with 80-grit sandpaper, and the surface flatness error should be controlled within 2mm after sanding. The base layer adhesive layer should be applied with a wool brush, and the brushing direction should be consistent to avoid missed areas or drips. When spraying the core insulation layer, the spray gun pressure should be controlled at 0.3-0.5MPa, the moving speed should be 0.5-1m / min, and it should be sprayed in two coats with a 1-hour interval between the two coats. The surface protective layer should be applied with a roller, and the application pressure should be uniform to ensure consistent coating thickness and avoid pinholes and bubbles.

[0066] S6. Finished Product Inspection: The performance of the exterior wall insulation coating formed in S5 is tested. If the test is qualified, it is a finished product. If the test is unqualified, the corresponding preparation step is returned to be prepared again and tested again.

[0067] Specifically, the finished product testing adopts a random sampling method, with 3 samples selected from each batch. The four core indicators of bonding strength, thermal conductivity, crack resistance and weather resistance are tested respectively. Detailed records are kept during the testing process, including testing time, instrument parameters, test results, etc., and a test report is generated. If a single sample fails to meet a certain indicator, the sampling must be doubled and the test must be repeated. If there are still unqualified samples, the batch of products is determined to be unqualified, and all of them are returned to the corresponding preparation steps to be re-prepared. After re-preparation, all indicators must be tested again until they are qualified.

[0068] The following is a further description with reference to the embodiments:

[0069] Example 1: A coating for exterior wall insulation, comprising a base bonding layer, a core insulation layer, and a surface protective layer, which are stacked sequentially. The raw materials for each layer are prepared in the following parts by weight:

[0070] Core insulation layer: 15 parts modified vitrified microspheres, 20 parts water-based acrylic emulsion, 8 parts expanded perlite, 3 parts basalt short fibers, 1 part silane coupling agent, 0.5 parts thickener, 0.3 parts defoamer, 1 part antifreeze, and 15 parts deionized water; wherein the mass ratio of modified vitrified microspheres to expanded perlite is 1.5:1;

[0071] Base bonding layer: 30 parts silicate cement, 10 parts acrylic resin, 15 parts quartz sand, 0.5 parts silane coupling agent, and 10 parts deionized water; wherein, the quartz sand is a mixture of 20-30 mesh and 40-60 mesh in a mass ratio of 1:2, and dried at 60℃ until the moisture content is ≤5%;

[0072] Surface protective layer: 15 parts fluorocarbon emulsion, 5 parts titanium dioxide, 3 parts talc, 0.5 parts UV stabilizer, 1 part film-forming agent, and 10 parts deionized water;

[0073] Basalt short fibers: 1mm chopped length, pretreated with silane coupling agent KH560.

[0074] The preparation method of the coating for external wall insulation includes the following steps:

[0075] S1. Preparation of modified vitrified microspheres: The vitrified microspheres were dried in an oven at 105℃ to constant weight, cooled to room temperature, and then immersed in a modification solution prepared from aqueous acrylic emulsion, deionized water, and γ-methacryloxypropyltrimethoxysilane for 2 hours. After immersion, the microspheres were removed and dried in an oven at 80℃ for 1 hour to obtain modified vitrified microspheres. The mass ratio of vitrified microspheres, aqueous acrylic emulsion, deionized water, and γ-methacryloxypropyltrimethoxysilane was 1:0.4:0.4:0.005.

[0076] S2. Preparation of base bonding layer slurry: Take 30 parts of silicate cement, 10 parts of acrylic resin, 15 parts of quartz sand, 0.5 parts of silane coupling agent, and 10 parts of deionized water. The quartz sand is dried at 60℃ in advance until the moisture content is ≤5%. First, add silicate cement and quartz sand to a mixer and stir at a low speed of 300r / min for 10min. Then add acrylic resin, silane coupling agent and deionized water and stir at a high speed of 800r / min for 20min to obtain base bonding layer slurry for later use.

[0077] S3. Preparation of core insulation layer slurry: Take 15 parts of modified vitrified microspheres prepared in S1, 20 parts of water-based acrylic emulsion, 8 parts of expanded perlite, 3 parts of basalt short fibers, 1 part of silane coupling agent, 0.5 parts of thickener, 0.3 parts of defoamer, 1 part of antifreeze, and 15 parts of deionized water. The basalt short fibers are pretreated with silane coupling agent KH560. First, add the modified vitrified microspheres, expanded perlite, and basalt short fibers to a mixer and stir at a low speed of 300 r / min for 5 min. Then add the water-based acrylic emulsion and silane coupling agent and stir at a medium speed of 600 r / min for 15 min. Then add the thickener, defoamer, antifreeze, and deionized water and stir at a high speed of 900 r / min for 25 min to obtain the core insulation layer slurry for later use.

[0078] S4. Preparation of surface protective layer slurry: Take 15 parts of fluorocarbon emulsion, 5 parts of titanium dioxide, 3 parts of talc, 0.5 parts of UV stabilizer, 1 part of film-forming agent, and 10 parts of deionized water. The titanium dioxide and talc are crushed and sieved in advance. First, add the titanium dioxide and talc to the mixer and stir at a low speed of 300 r / min for 8 min. Then add the fluorocarbon emulsion, UV stabilizer and film-forming agent and stir at a medium speed of 500 r / min for 15 min. Finally, add the deionized water and stir at a high speed of 800 r / min for 10 min to obtain the surface protective layer slurry for later use.

[0079] S5. Coating Forming: First, clean and grind the base layer of the building's exterior wall to ensure it is free of dust, oil, and hollow areas. Construction should be carried out under conditions of 5℃ ambient temperature and ≤80% relative humidity, avoiding rain and direct sunlight. Apply the base bonding slurry prepared in S2 to the base surface with a thickness of 0.5mm. Allow it to cure naturally for 24 hours under conditions of 10℃ ambient temperature and ≥50% relative humidity, avoiding collisions and friction on the coating surface during curing. After the base bonding layer has cured, spray the core insulation layer slurry prepared in S3 onto the base bonding layer surface. Keep the spray gun perpendicular to the wall and move at a uniform speed, achieving a spray thickness of 5mm. Allow it to cure naturally for 48 hours. After the core insulation layer has cured, apply the surface protective layer slurry prepared in S4 to the core insulation layer surface with a thickness of 0.3mm. Allow it to cure naturally for 24 hours to obtain the exterior wall insulation coating.

[0080] S6. Finished Product Inspection: The performance of the exterior wall insulation coating formed in S5 is tested. If the test is qualified, it is a finished product. If the test is unqualified, the corresponding preparation step is returned to be prepared again, and the test is carried out again after the preparation is completed.

[0081] Example 2: A coating for exterior wall insulation, comprising a base bonding layer, a core insulation layer, and a surface protective layer, which are stacked sequentially. The raw materials for each layer are prepared in the following parts by weight:

[0082] Core insulation layer: 20 parts modified vitrified microspheres, 25 parts water-based acrylic emulsion, 10 parts expanded perlite, 5 parts basalt short fibers, 2 parts silane coupling agent, 1.2 parts thickener, 0.7 parts defoamer, 1.5 parts antifreeze, and 20 parts deionized water; wherein the mass ratio of modified vitrified microspheres to expanded perlite is 2:1.

[0083] Base bonding layer: 35 parts silicate cement, 12 parts acrylic resin, 18 parts quartz sand, 1.0 part silane coupling agent, and 12 parts deionized water; wherein, the quartz sand is a mixture of 20-30 mesh and 40-60 mesh in a mass ratio of 1:2.5, and dried at 70℃ until the moisture content is ≤5%;

[0084] Surface protective layer: 20 parts fluorocarbon emulsion, 8 parts titanium dioxide, 4.5 parts talc, 1.0 part UV stabilizer, 1.5 parts film-forming agent, and 15 parts deionized water;

[0085] Basalt short fibers: 3mm chopped length, pretreated with silane coupling agent KH560.

[0086] The preparation method of the coating for external wall insulation includes the following steps:

[0087] S1. Preparation of modified vitrified microspheres: The vitrified microspheres were dried in an oven at 108℃ to constant weight, cooled to room temperature, and then immersed in a modification solution prepared from aqueous acrylic emulsion, deionized water, and γ-methacryloxypropyltrimethoxysilane. After soaking for 3 hours, they were removed and dried in an oven at 85℃ for 1.5 hours to obtain modified vitrified microspheres. The mass ratio of vitrified microspheres, aqueous acrylic emulsion, deionized water, and γ-methacryloxypropyltrimethoxysilane was 1:0.5:0.5:0.008.

[0088] S2. Preparation of base bonding layer slurry: Take 35 parts of silicate cement, 12 parts of acrylic resin, 18 parts of quartz sand, 1.0 part of silane coupling agent, and 12 parts of deionized water. The quartz sand is dried at 70℃ in advance until the moisture content is ≤5%. First, add the silicate cement and quartz sand to the mixer and stir at a low speed of 400r / min for 12min. Then add the acrylic resin, silane coupling agent and deionized water and stir at a high speed of 900r / min for 25min to obtain the base bonding layer slurry for later use.

[0089] S3. Preparation of core insulation layer slurry: Take 20 parts of modified vitrified microspheres prepared in S1, 25 parts of water-based acrylic emulsion, 10 parts of expanded perlite, 5 parts of basalt short fibers, 2 parts of silane coupling agent, 1.2 parts of thickener, 0.7 parts of defoamer, 1.5 parts of antifreeze, and 20 parts of deionized water. The basalt short fibers are pretreated with silane coupling agent KH560. First, add the modified vitrified microspheres, expanded perlite, and basalt short fibers to a mixer and stir at a low speed of 350 r / min for 8 min. Then add the water-based acrylic emulsion and silane coupling agent and stir at a medium speed of 700 r / min for 18 min. Then add the thickener, defoamer, antifreeze, and deionized water and stir at a high speed of 1000 r / min for 30 min to obtain the core insulation layer slurry for later use.

[0090] S4. Preparation of surface protective layer slurry: Take 20 parts of fluorocarbon emulsion, 8 parts of titanium dioxide, 4.5 parts of talc, 1.0 part of UV inhibitor, 1.5 parts of film-forming agent, and 15 parts of deionized water. The titanium dioxide and talc are crushed and sieved in advance. First, add the titanium dioxide and talc to the mixer and stir at a low speed of 350 r / min for 10 min. Then add the fluorocarbon emulsion, UV inhibitor and film-forming agent and stir at a medium speed of 600 r / min for 18 min. Finally, add the deionized water and stir at a high speed of 900 r / min for 12 min to obtain the surface protective layer slurry for later use.

[0091] S5. Coating Forming: First, clean and grind the base layer of the building's exterior wall to ensure it is free of dust, oil, and hollow areas. Construction should be carried out under conditions of 20℃ ambient temperature and relative humidity ≤80%, avoiding rain and direct sunlight. Apply the base bonding slurry prepared in S2 to the base surface with a thickness of 0.8mm. Allow it to cure naturally for 36 hours under conditions of 20℃ ambient temperature and relative humidity ≥50%, avoiding collisions and friction on the coating surface during curing. After the base bonding layer has cured, spray the core insulation layer slurry prepared in S3 onto the base bonding layer surface. Keep the spray gun perpendicular to the wall and move at a uniform speed, achieving a spray thickness of 6.5mm. Allow it to cure naturally for 60 hours. After the core insulation layer has cured, apply the surface protective layer slurry prepared in S4 to the core insulation layer surface with a thickness of 0.4mm. Allow it to cure naturally for 30 hours to obtain the exterior wall insulation coating.

[0092] S6. Finished Product Inspection: The performance of the exterior wall insulation coating formed in S5 is tested. If the test is qualified, it is a finished product. If the test is unqualified, the corresponding preparation step is returned to be prepared again, and the test is carried out again after the preparation is completed.

[0093] Example 3: A coating for exterior wall insulation, comprising a base bonding layer, a core insulation layer, and a surface protective layer, which are stacked sequentially. The raw materials for each layer are prepared in the following parts by weight:

[0094] Core insulation layer: 25 parts modified vitrified microspheres, 30 parts water-based acrylic emulsion, 10 parts expanded perlite, 8 parts basalt short fibers, 3 parts silane coupling agent, 2 parts thickener, 1 part defoamer, 2 parts antifreeze, and 25 parts deionized water; wherein, the mass ratio of modified vitrified microspheres to expanded perlite is 2.5:1.

[0095] Base bonding layer: 40 parts silicate cement, 15 parts acrylic resin, 20 parts quartz sand, 1.5 parts silane coupling agent, and 15 parts deionized water; wherein, the quartz sand is a mixture of 20-30 mesh and 40-60 mesh in a mass ratio of 1:3, and dried at 80℃ until the moisture content is ≤5%;

[0096] Surface protective layer: 25 parts fluorocarbon emulsion, 10 parts titanium dioxide, 6 parts talc, 1.5 parts UV stabilizer, 2 parts film-forming agent, 20 parts deionized water;

[0097] Basalt short fibers: 5mm chopped length, pretreated with silane coupling agent KH560.

[0098] The preparation method of the coating for external wall insulation includes the following steps:

[0099] S1. Preparation of modified vitrified microspheres: The vitrified microspheres were dried in an oven at 110℃ to constant weight, cooled to room temperature, and then immersed in a modification solution prepared from aqueous acrylic emulsion, deionized water, and γ-methacryloxypropyltrimethoxysilane for 4 hours. After immersion, the microspheres were removed and dried in an oven at 90℃ for 2 hours to obtain modified vitrified microspheres. The mass ratio of vitrified microspheres, aqueous acrylic emulsion, deionized water, and γ-methacryloxypropyltrimethoxysilane was 1:0.6:0.6:0.01.

[0100] S2. Preparation of base bonding layer slurry: Take 40 parts of silicate cement, 15 parts of acrylic resin, 20 parts of quartz sand, 1.5 parts of silane coupling agent, and 15 parts of deionized water. The quartz sand is dried at 80℃ in advance until the moisture content is ≤5%. First, add the silicate cement and quartz sand to the mixer and stir at a low speed of 500r / min for 15min. Then add the acrylic resin, silane coupling agent, and deionized water and stir at a high speed of 1000r / min for 30min to obtain the base bonding layer slurry for later use.

[0101] S3. Preparation of core insulation layer slurry: Take 25 parts of modified vitrified microspheres prepared in S1, 30 parts of water-based acrylic emulsion, 10 parts of expanded perlite, 8 parts of basalt short fibers, 3 parts of silane coupling agent, 2 parts of thickener, 1 part of defoamer, 2 parts of antifreeze, and 25 parts of deionized water. The basalt short fibers are pretreated with silane coupling agent KH560. First, add the modified vitrified microspheres, expanded perlite, and basalt short fibers to a mixer and stir at a low speed of 400 r / min for 10 min. Then add the water-based acrylic emulsion and silane coupling agent and stir at a medium speed of 800 r / min for 20 min. Then add the thickener, defoamer, antifreeze, and deionized water and stir at a high speed of 1100 r / min for 35 min to obtain the core insulation layer slurry for later use.

[0102] S4. Preparation of surface protective layer slurry: Take 25 parts of fluorocarbon emulsion, 10 parts of titanium dioxide, 6 parts of talc, 1.5 parts of UV stabilizer, 2 parts of film-forming agent, and 20 parts of deionized water. The titanium dioxide and talc are crushed and sieved in advance. First, add the titanium dioxide and talc to the mixer and stir at a low speed of 400 r / min for 12 min. Then add the fluorocarbon emulsion, UV stabilizer and film-forming agent and stir at a medium speed of 700 r / min for 20 min. Finally, add the deionized water and stir at a high speed of 1000 r / min for 15 min to obtain the surface protective layer slurry for later use.

[0103] S5. Coating Forming: First, clean and grind the base layer of the building's exterior wall to ensure it is free of dust, oil, and hollow areas. Construction should be carried out under conditions of 35℃ ambient temperature and relative humidity ≤80%, avoiding rain and direct sunlight. Apply the base bonding slurry prepared in S2 to the base surface with a thickness of 1mm. Allow it to cure naturally for 48 hours under conditions of 30℃ ambient temperature and relative humidity ≥50%, avoiding collisions and friction on the coating surface during curing. After the base bonding layer has cured, spray the core insulation layer slurry prepared in S3 onto the base bonding layer surface. Keep the spray gun perpendicular to the wall and move at a uniform speed, achieving a spray thickness of 8mm. Allow it to cure naturally for 72 hours. After the core insulation layer has cured, apply the surface protective layer slurry prepared in S4 to the core insulation layer surface with a thickness of 0.5mm. Allow it to cure naturally for 36 hours to obtain the exterior wall insulation coating.

[0104] S6. Finished Product Inspection: The performance of the exterior wall insulation coating formed in S5 is tested. If the test is qualified, it is a finished product. If the test is unqualified, the corresponding preparation step is returned to be prepared again, and the test is carried out again after the preparation is completed.

[0105] Comparative Example 1 differs from Example 2 in that, in the preparation of modified vitrified microspheres in S1, the cooling to room temperature step was omitted, and the vitrified microspheres dried to constant weight were directly immersed in the modification solution. All other process parameters were the same as in Example 2.

[0106] In Comparative Example 2, unlike Example 2, when preparing the core insulation layer slurry in S3, the staged stirring process was omitted. All raw materials were added to the mixer at the same time and stirred at a high speed of 1000 r / min for 30 min. All other process parameters were the same as in Example 2.

[0107] In Comparative Example 3, unlike Example 2, the curing step of the base layer adhesive layer was omitted during the S5 coating process. The core insulation layer slurry was sprayed immediately after the base layer adhesive layer was applied. All other process parameters were the same as in Example 2.

[0108] Comparative Example 4 differs from Example 2 in that the basalt short fibers were not pretreated with silane coupling agent KH560 and were directly added to the core insulation layer slurry. All other process parameters were the same as in Example 2.

[0109] Table 1, Performance Test Data Table

[0110] Group Bond strength (MPa) Thermal conductivity (W / (m·K)) Crack resistance (50 cycles at -20℃ to 80℃) Weather resistance (artificial climate aging for 1000 hours) Pass / Fail Status Example 1 0.62 0.027 No cracks No powdering, no peeling qualified Example 2 0.75 0.025 No cracks No powdering, no peeling qualified Example 3 0.78 0.024 No cracks No powdering, no peeling qualified Comparative Example 1 0.55 0.030 minor cracks Slight powdering Unqualified Comparative Example 2 0.58 0.029 Minor cracks No powdering, no peeling Unqualified Comparative Example 3 0.48 0.027 No cracks No powdering, no peeling Unqualified Comparative Example 4 0.61 0.028 Obvious cracks No powdering, no peeling Unqualified

[0111] Based on the differences between Examples 1-3 and Comparative Examples 1-4 and the performance test data table, it can be seen that the synergistic process of modified vitrified microsphere preparation, base bonding layer, core insulation layer, surface protective layer layered slurry preparation, staged mixing, layered construction and curing, and finished product testing in this invention has a significant impact on the bonding strength, thermal conductivity, crack resistance, and weather resistance of the exterior wall insulation coating. Moreover, the process links have a good effect on improving raw material compatibility, uniform slurry mixing, optimized coating formation, and enhanced performance stability, thus achieving the dual goals of efficient preparation and high performance of the exterior wall insulation coating.

[0112] Comparative Example 1, by omitting the cooling step of the vitrified microspheres and directly immersing the dried vitrified microspheres to constant weight into the modification liquid, resulted in insufficient modification of the vitrified microspheres, decreased compatibility with other raw materials, reduced bonding strength to 0.55 MPa (a 26.7% decrease compared to Example 2), increased thermal conductivity to 0.030 W / (m·K) (a 20.0% increase compared to Example 2), slight cracking in crack resistance, and slight powdering in weather resistance, making it a group with poor overall performance. At the same time, the core insulation layer was prone to clumping and delamination, failing to meet the requirements for building exterior wall insulation.

[0113] Comparative Example 2 uses a single high-speed mixing process instead of a staged mixing process. All raw materials for the core insulation layer are added to the mixer at the same time and mixed at high speed, resulting in uneven mixing of raw materials, poor dispersion of basalt short fibers, and a decrease in bonding strength to 0.58 MPa, a decrease of 22.7% compared to Example 2. The thermal conductivity increases to 0.029 W / (m·K), an increase of 16.0% compared to Example 2. A small number of cracks appear in the crack resistance, and voids are easily generated inside the coating, resulting in a significant decrease in thermal insulation effect and structural stability.

[0114] Comparative Example 3 lacked the base layer curing step. The core insulation layer slurry was sprayed immediately after the base layer was applied, resulting in poor bonding between the base layer and the base layer and the core insulation layer. The bonding strength dropped to 0.48 MPa, a decrease of 36.0% compared to Example 2. Although the thermal conductivity, crack resistance and weather resistance did not show obvious abnormalities, the coating was prone to blistering and peeling, which seriously affected the service life and safety performance of the external wall insulation coating.

[0115] Comparative Example 4 lacked the pretreatment step of basalt short fiber silane coupling agent KH560. The untreated basalt short fibers were directly added to the core insulation layer slurry, resulting in insufficient bonding force between the basalt short fibers and the slurry. This prevented the basalt short fibers from effectively resisting cracking, and the bonding strength dropped to 0.61 MPa, a decrease of 18.7% compared to Example 2. The thermal conductivity increased to 0.028 W / (m·K), an increase of 12.0% compared to Example 2. The crack resistance showed obvious cracks, and the coating was prone to cracking and damage after long-term use, resulting in a significant reduction in weather resistance and durability.

[0116] The core performance indicators of the exterior wall insulation coating prepared in the example are excellent, fully meeting the preset performance requirements: bonding strength ≥0.6MPa, thermal conductivity ≤0.028W / (m·K), no cracks after 50 cycles from -20℃ to 80℃, no powdering or peeling after 1000h of artificial climate aging. At the same time, it achieves efficient preparation and full utilization of raw materials for the exterior wall insulation coating. The coating is well formed and free from defects such as hollowness, peeling, and cracks. It has excellent comprehensive performance and can effectively reduce building energy consumption and extend the service life of the exterior wall.

[0117] Among them, Examples 1 and 3 are slightly inferior to Example 2 in performance due to the process parameters being at the boundary of the set range, but still maintain good overall advantages. Example 1 is suitable for low-cost general-purpose exterior wall insulation coating production scenarios. By adopting the minimum parameters of each step, the amount of raw materials and production energy consumption are controlled, reducing the production cost by 8% compared to Example 2. At the same time, it maintains the basic requirements of coating structure integrity and core performance compliance, and can be widely used in ordinary civil buildings, industrial plants and other scenarios with moderate requirements for thermal insulation performance. Example 3 is aimed at high-end high-performance exterior wall insulation demand scenarios. By adopting the maximum parameters of each step, the amount of modified vitrified microspheres and the amount of basalt short fiber added are increased, which further enhances the coating's bonding strength, thermal insulation performance and crack resistance, resulting in better stability and overall performance that is superior to the preset standard. It is suitable for high-rise buildings, buildings in cold regions and other application scenarios with high requirements for thermal insulation, crack resistance and weather resistance.

[0118] Example 2 achieves an optimal balance between performance and cost. Its process parameters are highly adaptable, the modified vitrified microspheres are fully prepared, the slurry layers are stirred evenly in stages, the layered construction and curing are reasonably coordinated, and the finished product testing is strict. The performance of the prepared external wall insulation coating is superior to the preset standard in all aspects. Moreover, the preparation process is stable, the coating forming rate is high, the production cycle is reasonable, no complex equipment is required, and it is easy to achieve large-scale continuous production. Its cost-effectiveness advantage is significant, with a 10% reduction in production cost compared to Example 3, an increase in bonding strength of more than 30% and a reduction in thermal conductivity of more than 15% compared to traditional external wall insulation coatings, and an improvement in crack resistance and weather resistance of more than 25% compared to existing external wall insulation coating preparation technologies. It can be widely adapted to various scenarios such as civil buildings, industrial buildings, and high-rise buildings, covering the full range of needs from ordinary insulation to high-end weather-resistant insulation.

[0119] The core processes in Examples 1-3 exhibit a deep synergistic effect: the preparation of modified vitrified microspheres and the staged mixing of the core insulation layer slurry work synergistically to improve the compatibility and uniformity of raw materials, laying the foundation for the coating's insulation and crack resistance performance; the preparation and application of the layered slurry for the base bonding layer, core insulation layer, and surface protective layer work synergistically to ensure tight bonding between the coating layers, achieving multiple effects of insulation, waterproofing, crack resistance, and weather resistance; the staged mixing and layered curing work synergistically to optimize the internal structure of the coating, avoiding problems such as hollowing, cracking, and peeling; and the finished product testing works synergistically with each preparation step to promptly identify and rework unqualified products, ensuring stable and compliant coating performance, improving production efficiency, and reducing production costs.

[0120] Example 2 optimizes the drying temperature of the modified vitrified microspheres to 108℃, the soaking time to 3h, and the drying time to 1.5h. It also adapts the stirring speed and time of each layer of slurry in stages, and achieves a base bonding layer coating thickness of 0.8mm and a curing time of 36h, a core insulation layer spraying thickness of 6.5mm and a curing time of 60h, and a surface protective layer coating thickness of 0.4mm and a curing time of 30h. This achieves seamless connection between each process step, maximizes the synergistic advantages, and fully demonstrates the scientificity, rationality, and feasibility of the process parameter range of the present invention.

[0121] Comparative Examples 1-4 suffered from the loss or alteration of a single process step, resulting in a break in the overall synergistic chain: Comparative Example 1 lacked the vitrified microsphere cooling step, damaging the modification effect and raw material compatibility; Comparative Example 2 changed the stirring method of the core insulation layer, affecting the uniformity of raw material mixing and the coating structure; Comparative Example 3 eliminated the curing of the base bonding layer, losing the foundation for the tight bonding of each coating layer; Comparative Example 4 eliminated the pretreatment of basalt short fibers, weakening the crack resistance of the coating. All of these examples demonstrate the irreplaceable nature of the key process steps and parameter selections in this invention, further illustrating that the synergistic effect of each process step is the core guarantee for achieving high-performance and high-stability preparation of external wall insulation coatings.

[0122] In summary, this invention, through its core technology design of modified vitrified microsphere preparation, layered slurry preparation, staged mixing, layered construction and curing, and finished product testing, combined with the synergistic optimization of various process parameters, effectively solves the technical problems of traditional external wall insulation coatings, such as poor adhesion, easy delamination and detachment, poor thermal insulation performance, and poor crack resistance and weather resistance. It also addresses existing preparation technologies such as uneven raw material mixing, unstable coating performance, low production efficiency, and difficulty in large-scale production. This significantly improves the overall performance and production efficiency of external wall insulation coatings, enabling efficient preparation and high-value application of external wall insulation coatings. Simultaneously, it simplifies the production process, controls production costs, eliminates the need for complex equipment, aligns with the development concepts of building energy conservation and green environmental protection, and has broad application prospects.

[0123] Bond strength: Referring to the "Technical Standard for External Wall Insulation Engineering" JGJ144-2019 (industry standard, applicable to the bonding performance testing of external wall insulation coatings) and the "Standard for Testing the Bond Strength of Facing Bricks in Building Engineering" JGJ / T110, and combined with the coating characteristics of this invention, the qualified standard is set as ≥0.6MPa, which is consistent with the preset requirements in the data table, and also meets the core requirement of ≥0.6MPa of bonding strength with concrete substrate in JGJ144-2019.

[0124] The pull-out test method was used, and the adhesion tester was employed for testing. 100mm × 100mm samples were randomly selected from the coating products prepared in the examples and comparative examples. Three parallel samples were selected for each group, ensuring that the samples were free of voids, cracks, and damage, with the fracture line cut to the surface of the insulation layer. The sample surface was cleaned to remove dust and impurities. A pull-out block was attached to the back of the sample, ensuring a firm bond and no air bubbles. The pull-out block was connected to the adhesion tester, and a uniform tensile force was applied until the sample peeled or broke. The maximum tensile force value was recorded. The bond strength was calculated as: maximum tensile force value / sample stress area. The arithmetic mean of the three parallel samples was taken as the final test result. If the failure interface was inside the mortar, the test result was valid; if an abnormal value was found, resampling and testing were required.

[0125] Thermal conductivity: Referring to the "Construction Quality Acceptance Standard for Building Energy Conservation Engineering" GB50411-2019 and the "Determination of Steady-State Thermal Resistance and Related Properties of Thermal Insulation Materials - Protective Hot Plate Method" GB / T10294-2008, the qualified standard is set to ≤0.028W / (m·K), which meets the core requirements of high-efficiency thermal insulation of external wall insulation coatings, matches the preset requirements in the data sheet, and follows the testing specifications for thermal conductivity of thermal insulation mortar in GB50411-2019.

[0126] The protective hot plate method was employed, and a thermal conductivity meter was used for testing. Samples meeting the instrument's size requirements were cut from the finished coating. Two parallel samples were selected for each group, and the samples had to come from the same mixing pan to ensure uniform thickness, no voids, and no damage. The samples were conditioned for 24 hours in an environment of 23±2℃ and 50±5% relative humidity. The dry density of the samples was tested first, followed by the thermal conductivity test. The samples were placed between the protective hot and cold plates of the thermal conductivity meter, ensuring a tight fit without gaps. The test temperature was set to 23±2℃. After the instrument stabilized, parameters such as heat flux density and temperature difference were recorded. The thermal conductivity was calculated using the instrument's built-in formula, combined with heat flux density, sample thickness, and temperature difference. The arithmetic mean of the two parallel samples was taken as the final test result, with an allowable deviation of ≤±0.002W / (m·K).

[0127] Crack resistance: Referring to JG / T158-2013 (industry standard) "Materials for External Wall Insulation System of Powdered Polystyrene Particles" and GB / T17357-2008 "Test Method for Long-term Thermal Stability of Thermal Insulation Materials", and considering the application scenarios of the coating of this invention, the qualified standard is set as no cracks after 50 cycles from -20℃ to 80℃. At the same time, referring to the relevant requirements for impact resistance and flexibility in JG / T158-2013, the structural stability of the coating under extreme temperature difference environments is ensured.

[0128] The high and low temperature cycling test method was adopted, and the test was conducted using a high and low temperature test chamber. A 200mm × 200mm sample was cut from the finished coating, with three parallel samples selected for each group, ensuring the sample surface was flat and free of initial cracks. The sample was placed in an environment of 23±2℃ for 24 hours to allow it to acclimatize. The test chamber parameters were set as follows: high temperature stage 80±2℃, constant temperature for 2 hours; low temperature stage -20±2℃, constant temperature for 2 hours; heating and cooling rates were both 5℃ / min, completing one cycle, for a total of 50 cycles. After the cycle, the sample was removed and allowed to recover at room temperature for 2 hours. The sample surface was then observed visually and with a magnifying glass for cracks, hollow areas, peeling, etc. The absence of any cracks indicated a pass; if cracks appeared, the crack length and width were recorded, and the sample was deemed unqualified.

[0129] Weather resistance: Referring to GB / T35169-2017 "Test Method for Weather Resistance of Building Exterior Wall Insulation System" and JGJ144-2019 "Technical Standard for Exterior Wall Insulation Engineering", the qualified standard is set as no powdering or peeling after 1000 hours of artificial climate aging, which meets the weather resistance requirements for long-term outdoor use of exterior wall insulation coatings, consistent with the preset requirements in the data sheet, and strictly follows the core specifications of weather resistance testing in GB / T35169-2017.

[0130] Artificial climate aging testing was conducted using an artificial climate aging test chamber. Large-sized specimens identical to the actual construction structure were prepared, one specimen per group. The specimen structure was completely identical to the actual construction, with the side insulation layer thickness controlled at 20mm~25mm. The specimens were placed in an environment of 23±2℃ and 50±5% relative humidity for 7 days for conditioning. The test chamber parameters were set to simulate outdoor climate conditions, controlling parameters such as temperature, humidity, and spray water. The temperature measurement accuracy was no greater than 1℃, and the humidity measurement accuracy was no greater than 3%. The spray water nozzle was 10cm~20cm away from the specimen surface to ensure complete coverage. A 1000-hour artificial climate aging test was conducted continuously, observing the specimen condition after every four high-temperature water spray cycles and each heating-freezing cycle. After the aging test, the specimens were conditioned for 7 days, and the surface was observed for powdering, peeling, cracking, discoloration, etc. The specimen surface was tested by hand; no powdering or peeling indicated a pass. Simultaneously, the tensile bond strength of the specimens was tested to verify the stability of the weathered performance. Powdering or peeling indicated a fail.

[0131] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A coating for exterior wall insulation, characterized in that, It includes a base bonding layer, a core insulation layer, and a surface protective layer, which are stacked sequentially. The core insulation layer comprises the following raw materials in parts by weight: 15-25 parts modified vitrified microspheres, 20-30 parts water-based acrylic emulsion, 8-15 parts expanded perlite, 3-8 parts basalt short fibers, 1-3 parts silane coupling agent, 0.5-2 parts thickener, 0.3-1 part defoamer, 1-2 parts antifreeze, and 15-25 parts deionized water.

2. The coating for external wall insulation according to claim 1, characterized in that, The base bonding layer comprises the following raw materials in parts by weight: 30-40 parts silicate cement, 10-15 parts acrylic resin, 15-20 parts quartz sand, 0.5-1.5 parts silane coupling agent, and 10-15 parts deionized water. The surface protective layer comprises the following raw materials in parts by weight: 15-25 parts fluorocarbon emulsion, 5-10 parts titanium dioxide, 3-6 parts talc, 0.5-1.5 parts UV stabilizer, 1-2 parts film-forming agent, and 10-20 parts deionized water.

3. The coating for external wall insulation according to claim 1, characterized in that, In the core insulation layer, the mass ratio of modified vitrified microspheres to expanded perlite is 1.5-2.5:

1.

4. The coating for external wall insulation according to claim 2, characterized in that, The basalt short fibers have a chopped length of 1-5 mm and are pretreated with silane coupling agent KH560; the thickener is hydroxypropyl methylcellulose, the defoamer is an organosilicon defoamer, the antifreeze agent is ethylene glycol, and the film-forming agent is polyethylene glycol.

5. The coating for external wall insulation according to claim 2, characterized in that, The quartz sand is a mixture of 20-30 mesh and 40-60 mesh in a mass ratio of 1:2-3, and is dried at 60-80℃ to a moisture content of ≤5%; the titanium dioxide is rutile titanium dioxide, and the talc has a particle size of 100-120 mesh.

6. A method for preparing a coating for external wall insulation, characterized in that, Includes the following steps: S1. Preparation of modified vitrified microspheres: After drying the vitrified microspheres, they are immersed in a modification solution prepared by aqueous acrylic emulsion, deionized water and γ-methacryloyloxypropyltrimethoxysilane. After immersion, they are dried again to obtain modified vitrified microspheres. S2. Preparation of base bonding layer slurry: Take silicate cement, acrylic resin, quartz sand, silane coupling agent and deionized water. First, mix silicate cement and quartz sand, then add the remaining raw materials and continue mixing to obtain base bonding layer slurry. S3. Preparation of core insulation layer slurry: Take the modified vitrified microspheres, water-based acrylic emulsion, expanded perlite, basalt short fibers, silane coupling agent, thickener, defoamer, antifreeze agent and deionized water prepared in S1. First, mix and stir the modified vitrified microspheres, expanded perlite and basalt short fibers. Then, add the water-based acrylic emulsion, silane coupling agent and the remaining raw materials in sequence and stir in stages to obtain the core insulation layer slurry. S4. Preparation of surface protective layer slurry: Take fluorocarbon emulsion, titanium dioxide, talc, UV stabilizer, film-forming agent and deionized water. First, mix and stir the titanium dioxide and talc, then add the remaining raw materials and continue stirring to obtain the surface protective layer slurry. S5. Coating Forming: First, clean and grind the base layer of the building's exterior wall. Then, apply the slurry prepared in S2-S4 in layers. After each layer is completed, allow it to cure naturally. After all construction and curing are completed, the coating for exterior wall insulation is obtained. S6. Finished Product Inspection: The performance of the exterior wall insulation coating formed in S5 is tested. If the test is qualified, it is a finished product. If the test is unqualified, the corresponding preparation step is returned to be prepared again, and the test is carried out again after the preparation is completed.

7. The method for preparing an exterior wall insulation coating according to claim 6, characterized in that, In step S1, the vitrified microspheres are dried at a temperature of 105-110°C, dried to constant weight, cooled to room temperature, and then soaked. The soaking time of the modified solution is 2-4 hours, and the drying temperature after soaking is 80-90℃, and the drying time is 1-2 hours. The mass ratio of vitrified microspheres, aqueous acrylic emulsion, deionized water, and γ-methacryloyloxypropyltrimethoxysilane is 1:0.4-0.6:0.4-0.6:0.005-0.

01.

8. The method for preparing an exterior wall insulation coating according to claim 6, characterized in that, In S2, the quartz sand needs to be dried at 60-80℃ in advance until the moisture content is ≤5%; The mixing process is divided into two stages. The first stage is low-speed mixing, with a speed of 300-500 r / min and a mixing time of 10-15 min. The second stage is high-speed mixing, with a speed of 800-1000 r / min and a mixing time of 20-30 min. In S3, the basalt short fibers need to be pretreated with silane coupling agent KH560 in advance; The mixing process is divided into three stages: the first stage is low-speed mixing, with a speed of 300-400 r / min and a mixing time of 5-10 min; the second stage is medium-speed mixing, with a speed of 600-800 r / min and a mixing time of 15-20 min; and the third stage is high-speed mixing, with a speed of 900-1100 r / min and a mixing time of 25-35 min.

9. The method for preparing an exterior wall insulation coating according to claim 6, characterized in that, In step S4, titanium dioxide and talc need to be pulverized and sieved in advance; the stirring is divided into three stages. The first stage is low-speed stirring, with a speed of 300-400 r / min and a stirring time of 8-12 min. The second stage is medium-speed mixing, with a speed of 500-700 r / min and a mixing time of 15-20 min; the third stage is high-speed mixing, with a speed of 800-1000 r / min and a mixing time of 10-15 min.

10. The method for preparing an exterior wall insulation coating according to claim 6, characterized in that, In S5, the base layer is cleaned and sanded to ensure that there is no floating dust, oil stains, or hollow areas. The base layer bonding layer is applied by brushing, the surface protective layer is applied by brushing, and the core insulation layer is applied by spraying. When spraying, the spray gun is kept perpendicular to the wall and the moving speed is uniform. The construction environment temperature is 5-35℃, and the relative humidity is ≤80%. Avoid rain and direct sunlight during construction. The curing environment temperature is 10-30℃, and the relative humidity is ≥50%. Avoid collisions and friction on the coating surface during the curing period. The thickness of the base bonding layer is 0.5-1mm, and the curing time is 24-48h; the thickness of the core insulation layer is 5-8mm, and the curing time is 48-72h; the thickness of the surface protective layer is 0.3-0.5mm, and the curing time is 24-36h.

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