Organic silicon modified external wall thermal insulation coating and preparation method thereof

Abstract

The invention relates to the technical field of building coatings, and discloses an organosilicon-containing modified external wall thermal insulation coating and a preparation method thereof. The basic coating comprises the following components: 30-45% of an acrylic elastic emulsion, 15-25% of a reflective functional pigment, 10-15% of titanium dioxide, 12-18% of calcium carbonate, 0.5-1.5% of cellulose, 3.5-6.5% of a thickening aid and the balance of water, the raw material components are uniformly mixed, the flatting agent, the hydrogen-containing silicone oil emulsion and the defoaming silicon paste are added, the materials are uniformly stirred, and ball milling is performed to obtain the external wall thermal insulation coating. Through the synergistic effect of the 8844C type flatting agent, the polyester modified hydrogen-containing silicone oil emulsion and the 7300 type organic defoaming agent, the comprehensive performance and appearance of a coating can be remarkably improved, a flat, smooth and defect-free compact paint film is formed, the low surface tension provided by the flatting agent enables the coating to have the self-cleaning performance, and the self-cleaning performance is good. Si-O-Si bonds formed by the hydrogen-containing silicone oil emulsion and the basic coating have water resistance, acid resistance, alkali resistance, salt resistance and heat insulation performance.

Description

Technical Field

[0001] This invention relates to the field of building coatings technology, specifically to an organosilicon-modified exterior wall thermal insulation coating and its preparation method. Background Technology

[0002] Exterior wall thermal insulation coatings, as core functional materials in the field of building energy conservation, are of strategic significance in reducing building cooling energy consumption in high-temperature and high-humidity climates. Due to their lightweight, excellent waterproofing, and good toughness, thermal insulation coatings integrate waterproofing, thermal insulation, and exterior protection functions, and simplify construction processes. With the rapid development of the oil extraction and petrochemical industries, they will save significant amounts of energy and have excellent development prospects. Thermal insulation coatings based on acrylic elastic emulsions, with their superior weather resistance and construction adaptability, occupy a dominant position in the global market. Their thermal insulation mechanism relies on an optical scattering system constructed from titanium dioxide and infrared-reflecting pigments, achieving selective reflection through a high-refractive-index interface (rutile TiO2, n=2.7). However, existing technologies have many drawbacks: although core-shell structured pigments (CN112300704A) can alleviate agglomeration, a porosity of more than 15% disrupts the continuity of emulsion film formation, and production costs increase by 200%. The staged addition of additives process (CN113736276A) cannot overcome migration kinetic conflicts, forcing the application window to be shortened to a dangerous critical point (<5 min). The fluorosilicone copolymer solution (US20170335106) faces compliance risks due to the fluorine-containing components and the EU PFAS ban.

[0003] Therefore, how to develop a coating using acrylic acid as a raw material that can overcome the defects such as poor dispersibility and easy agglomeration in exterior wall thermal insulation coatings, so as to achieve good thermal insulation effect, is a difficult problem that those skilled in the art are committed to solving. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention utilizes the synergistic effect of 8844C leveling agent, hydrogen-containing silicone oil emulsion, and 7300 type defoamer to resolve the contradiction between dispersion and surface defects, reduce the surface tension of the coating to provide self-cleaning properties, construct a hydrophobic layer, improve acid, alkali, and salt resistance, and enhance the thermal insulation performance of the coating.

[0005] The technical solution of this invention is described in detail below:

[0006] This invention provides a method for preparing an exterior wall thermal insulation coating modified with organosilicon oil. The thermal insulation coating is composed of an acrylic elastic base coating and a novel composite additive. The specific preparation steps are as follows:

[0007] (1) Preparation of base coating: Based on the total mass of the base coating, the raw material components of the base coating are: 30-45% acrylic elastic emulsion, 15-25% reflective functional pigment, 10%-15% titanium dioxide, 12%-18% calcium carbonate, 0.5-1.5% cellulose, 3.5-6.5% thickening agent, and the balance is water. The above raw material components are mixed evenly to prepare the base coating.

[0008] (2) Addition of leveling agent: Add 0.3-0.8% of the leveling agent by weight to the base coating and stir evenly;

[0009] (3) Addition of hydrogen-containing silicone oil emulsion: Add 0.5-1.2% of the mass of the base coating and 0.1-0.5% of the mass of the base coating defoaming silicone paste to the coating obtained in step (2), stir evenly, ball mill to refine to a particle size <50μm, let stand, and obtain organosilicon modified exterior wall thermal insulation coating.

[0010] Furthermore, the reflective functional pigment is hollow microspheres, the titanium dioxide is reflective titanium dioxide, the cellulose is hydroxyethyl cellulose, and the thickening agent is fiber-associated polyurethane.

[0011] Furthermore, in step (2) above, the leveling agent is a polyester-modified silicone 8844C type leveling agent.

[0012] Furthermore, in step (3), the hydrogen-containing silicone oil emulsion is a polyester-modified organosilicon emulsion; and the defoaming silicone paste is a 7300 type organic defoamer.

[0013] Furthermore, in step (2) above, the stirring time is 5-6 hours.

[0014] Furthermore, in step (3), the stirring time is 1-3 hours.

[0015] Furthermore, in steps (2) and (3), the stirring temperature is 25±2℃ and the stirring speed is 800-1000r / min.

[0016] Furthermore, in step (3), the settling time is 12 hours and the settling temperature is 25±2℃.

[0017] The present invention also provides an organosilicon-modified exterior wall thermal insulation coating prepared by the above preparation method.

[0018] The present invention also provides the application of the organosilicon-modified exterior wall thermal insulation coating obtained by the above preparation method in the field of thermal insulation of exterior walls of urban infrastructure, factory exterior walls and self-built grain warehouses.

[0019] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0020] 1. The acrylic elastic thermal insulation coating provided by this invention, through the synergistic effect of adding 8844C leveling agent, polyester modified hydrogen-containing silicone oil emulsion and 7300 organic defoamer, can significantly improve the overall performance and appearance of the coating, forming a smooth, defect-free, and dense paint film. The low surface tension provided by the leveling agent gives the coating self-cleaning properties, and the Si-O-Si bonds formed by the hydrogen-containing silicone oil emulsion and the base coating have waterproof, acid and alkali resistance, salt resistance and thermal insulation properties.

[0021] 2. The acrylic elastic thermal insulation coating provided by this invention forms a uniform, dense, and defect-free continuous protective layer, optimizes the integrity of the coating structure and isolates moisture, giving the coating good thermal insulation function and excellent corrosion resistance. It can be used as a thermal insulation coating for the exterior walls of urban infrastructure, factories and self-built grain warehouses. Attached Figure Description

[0022] Figure 1 This is a diagram illustrating the thermal insulation performance of the exterior wall insulation coating of this invention. Detailed Implementation

[0023] The following embodiments are intended to enable those skilled in the art to more fully understand the present invention, but do not limit the invention in any way.

[0024] In the following examples and comparative examples, the reflective functional pigment is hollow microspheres, the titanium dioxide is reflective titanium dioxide, the cellulose is hydroxyethyl cellulose, and the thickening agent is associative polyurethane.

[0025] Example 1

[0026] (1) Stir 20g of base coating (8g of acrylic elastic emulsion, 4.3g of reflective functional pigment, 2.6g of titanium dioxide, 3g of calcium carbonate, 0.12g of cellulose, 0.75g of thickener, and 1.23g of water) thoroughly for 1 hour to obtain a base coating with uniformly dispersed components;

[0027] (2) Add 0.06g of 8844C leveling agent to the base coating and disperse at high speed for 3h to obtain a modified coating that is not completely defoamed;

[0028] (3) Add 0.1g of hydrogen-containing silicone oil and 0.05g of defoaming silicone paste to the coating obtained in step (2), stir at 1500rpm / min for 2h, ball mill the resulting dispersion system to a particle size of <50μm, and let it stand at room temperature for 12h to obtain the organosilicon-modified exterior wall thermal insulation coating.

[0029] Example 2

[0030] (1) Stir 20g of base coating (8g of acrylic elastic emulsion, 4.3g of reflective functional pigment, 2.6g of titanium dioxide, 3g of calcium carbonate, 0.12g of cellulose, 0.75g of thickener, and 1.23g of water) thoroughly for 1 hour to obtain a base coating with uniformly dispersed components;

[0031] (2) Add 0.06g of 8844C leveling agent to the base coating and disperse at high speed for 3h to obtain a modified coating that is not completely defoamed;

[0032] (3) Add 0.15g of hydrogen-containing silicone oil and 0.05g of defoaming silicone paste to the coating obtained in step (2) and stir at 1500rpm / min for 2h. Ball mill the resulting dispersion system to a particle size of <50μm and let it stand at room temperature for 12h to obtain the organosilicon-modified exterior wall thermal insulation coating.

[0033] Example 3

[0034] (1) Stir 20g of base coating (8g of acrylic elastic emulsion, 4.3g of reflective functional pigment, 2.6g of titanium dioxide, 3g of calcium carbonate, 0.12g of cellulose, 0.75g of thickener, and 1.23g of water) thoroughly for 1 hour to obtain a base coating with uniformly dispersed components;

[0035] (2) Add 0.06g of 8844C leveling agent to the base coating and disperse at high speed for 3h to obtain a modified coating that is not completely defoamed;

[0036] (3) Add 0.2g of hydrogen-containing silicone oil and 0.05g of defoaming silicone paste to the coating obtained in step (2) and stir at 1500rpm / min for 2h. Ball mill the resulting dispersion system to a particle size of <50μm and let it stand at room temperature for 12h to obtain the organosilicon-modified exterior wall thermal insulation coating.

[0037] Example 4

[0038] (1) Stir 20g of base coating (9g of acrylic elastic emulsion, 4.2g of reflective functional pigment, 2.6g of titanium dioxide, 3g of calcium carbonate, 0.12g of cellulose, 0.75g of thickener, and the remainder is water) for 1 hour to obtain a base coating with uniformly dispersed components;

[0039] (2) Add 0.06g of 8844C leveling agent to the base coating and disperse at high speed for 3h to obtain a modified coating that is not completely defoamed;

[0040] (3) Add 0.1g of hydrogen-containing silicone oil and 0.05g of defoaming silicone paste to the coating obtained in step (2), stir at 1500rpm / min for 2h, ball mill the resulting dispersion system to a particle size of <50μm, and let it stand at room temperature for 12h to obtain the organosilicon-modified exterior wall thermal insulation coating.

[0041] Example 5

[0042] (1) Stir 20g of base coating (8.5g of acrylic elastic emulsion, 5g of reflective functional pigment, 2.6g of titanium dioxide, 3g of calcium carbonate, 0.12g of cellulose, 0.75g of thickener, and the remainder is water) for 1 hour to obtain a base coating with uniformly dispersed components;

[0043] (2) Add 0.06g of 8844C leveling agent to the base coating and disperse at high speed for 3h to obtain a modified coating that is not completely defoamed;

[0044] (3) Add 0.1g of hydrogen-containing silicone oil and 0.05g of defoaming silicone paste to the coating obtained in step (2), stir at 1500rpm / min for 2h, ball mill the resulting dispersion system to a particle size of <50μm, and let it stand at room temperature for 12h to obtain the organosilicon-modified exterior wall thermal insulation coating.

[0045] Comparative Example 1

[0046] (1) Stir 20g of base coating (8g of acrylic elastic emulsion, 4.3g of reflective functional pigment, 2.6g of titanium dioxide, 3g of calcium carbonate, 0.12g of cellulose, 0.75g of thickener, and 1.23g of water) thoroughly for 1 hour to obtain a base coating with uniformly dispersed components;

[0047] (2) Add 0.06g of 8844C leveling agent to the base coating and disperse at high speed for 3h to obtain a modified coating that is not completely defoamed;

[0048] (3) Add 0.05g of defoaming silicone paste to the coating obtained in step (2) and stir at 1500rpm / min for 2h. Ball mill the resulting dispersion system to a particle size of <50μm and let it stand at room temperature for 12h to obtain the comparative coating.

[0049] Comparative Example 2

[0050] (1) Stir 20g of base coating (8g of acrylic elastic emulsion, 4.3g of reflective functional pigment, 2.6g of titanium dioxide, 3g of calcium carbonate, 0.12g of cellulose, 0.75g of thickener, and 1.23g of water) thoroughly for 1 hour to obtain a base coating with uniformly dispersed components;

[0051] (2) Add 0.05g of defoaming silicone paste to the base coating and stir at 1500rpm / min for 2h. Ball mill the resulting dispersion system to a particle size of <50μm and let it stand at room temperature for 12h to obtain the comparative coating.

[0052] Performance testing:

[0053] The coatings of Examples 1-3 and Comparative Examples 1-2 were uniformly applied to an exterior wall sample using a 100μm scraper. The coatings were then subjected to performance testing, and the test results are shown in Table 1.

[0054] Thermal insulation performance test: The silicone-modified exterior wall thermal insulation coatings prepared in Examples 1-3 and the coatings prepared in Comparative Examples 1-2 were applied to the treated exterior wall samples. After the coatings cured, they were placed in an infrared radiation heating device, and the temperatures of the heated side and the reverse side of the panels were recorded. The test results are as follows: Figure 1 As shown.

[0055] The specific experimental procedure is as follows: An exterior wall sample with a length and width of 30 cm and a thickness of 2 cm was prepared, along with an infrared radiation heater and a 100 μm scraper. After placing the exterior wall sample horizontally, the coatings prepared in Examples 1-3 and Comparative Examples 1-2 were evenly applied to the sample using the 100 μm scraper and left to stand overnight. Subsequently, the exterior wall sample coated with the coatings from Examples 1-3 and Comparative Examples 1-2 was heated using the infrared radiation heater. The side facing the infrared radiation was designated as the heated side, and the side facing away was designated as the reverse side. The real-time temperatures of the heated and reverse sides were recorded using a thermometer.

[0056] Table 1 Performance Tests of Coatings in Examples 1-3 and Comparative Examples 1-2

[0057]

[0058]

[0059] As shown in Table 1, the coatings obtained in Examples 1-3 exhibit better acid resistance, alkali resistance, and salt resistance than those in Comparative Examples 1-2, and also demonstrate better thermal insulation performance. Therefore, this invention is a high-performance water-based thermal insulation coating suitable for urban infrastructure exterior walls, factory exterior walls, and self-built grain silo exterior walls.

[0060] Figure 1 This is a diagram verifying the thermal insulation performance of the coating in this invention. From... Figure 1 The temperature difference between the heated surface and the reverse side of the heating plate in Example 1 is as high as 19°C, while the temperature difference between the heated surface and the reverse side of the heating plate in Comparative Examples 1-2 is only about 7°C. This shows that the prepared water-based thermal insulation coating has excellent thermal insulation effect.

[0061] Furthermore, the preparation method of the water-based thermal insulation coating of the present invention reduces the surface tension of the coating by using 8844C type leveling agent, thereby giving the coating good self-cleaning properties.

[0062] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for preparing an organosilicon-modified exterior wall thermal insulation coating, characterized in that, The specific preparation steps are as follows: (1) Preparation of base coating: Based on the total mass of the base coating, the raw material components of the base coating are: 30-45% acrylic elastic emulsion, 15-25% reflective functional pigment, 10%-15% titanium dioxide, 12%-18% calcium carbonate, 0.5-1.5% cellulose, 3.5-6.5% thickening agent, and the balance is water. The above raw material components are mixed evenly to prepare the base coating. (2) Addition of leveling agent: Add 0.3-0.8% of the leveling agent by weight to the base coating and stir evenly; (3) Addition of hydrogen-containing silicone oil emulsion: Add 0.5-1.2% of the mass of the base coating and 0.1-0.5% of the mass of the base coating defoaming silicone paste to the coating obtained in step (2), stir evenly, ball mill to refine to a particle size <50μm, let stand, and obtain organosilicon modified exterior wall thermal insulation coating.

2. The preparation method according to claim 1, characterized in that, In step (1), the reflective functional pigment is hollow microspheres, the titanium dioxide is reflective titanium dioxide, the cellulose is hydroxyethyl cellulose, and the thickening agent is associative polyurethane.

3. The preparation method according to claim 1, characterized in that, In step (2), the leveling agent is a polyester-modified silicone 8844C type leveling agent.

4. The preparation method according to claim 1, characterized in that, In step (3), the hydrogen-containing silicone oil emulsion is a polyester-modified organosilicon emulsion; the defoaming silicone paste is a 7300 type organic defoamer.

5. The preparation method according to claim 1, characterized in that, In step (2), the stirring time is 5-6 hours.

6. The preparation method according to claim 1, characterized in that, In step (3), the stirring time is 1-3 hours.

7. The preparation method according to claim 1, characterized in that, In steps (2) and (3), the stirring temperature is 25±2℃ and the stirring speed is 800-1000r / min.

8. The preparation method according to claim 1, characterized in that, In step (3), the settling time is 12 hours and the settling temperature is 25±2℃.

9. An organosilicon-modified exterior wall thermal insulation coating prepared by the preparation method according to claims 1 to 8.

10. The application of the organosilicon-modified exterior wall thermal insulation coating according to claim 9, characterized in that, It is used for thermal insulation of exterior walls of urban infrastructure, factories, and self-built grain warehouses.

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