A waterborne insulating coating and a method of preparation

Abstract

The application relates to the technical field of paint, and particularly discloses a water-based insulating paint and a preparation method; the water-based insulating paint comprises components A and B, the mass ratio of the components A and B is (7-9):1, the component A comprises the following raw materials in parts by weight: deionized water 100-150 parts, bentonite 3-8 parts, fumed silica 3-8 parts, titanium white 40-80 parts, barium sulfate 90-110 parts, mica powder 40-60 parts, zinc phosphate 60-80 parts, feldspar powder 40-60 parts, epoxy emulsion 400-500 parts, base material wetting agent 3-5 parts and dispersant 30-80 parts; the component B comprises the following raw materials in parts by weight: curing agent 40-60 parts and solvent 40-60 parts; the dispersant comprises a sulfonate dispersant and a polycarboxylate dispersant; the application promotes the insulating performance of the paint through the synergistic effect of various components, reduces the agglomeration of particles in the paint system, and improves the dispersing performance of the paint.

Description

Technical Field

[0001] The present application relates to the field of coating technology, and more specifically, to a water-based insulating coating and a preparation method thereof. Background Art

[0002] With growing environmental awareness, water-based coatings are gaining widespread attention due to their environmentally friendly, non-toxic, and pollution-free properties. Water-based insulating coatings, with their excellent insulating properties, hold broad application prospects in the fields of electricity, electronics, and more. However, current commercially available water-based insulating coatings present numerous challenges during use.

[0003] Traditional water-based insulating coatings mainly include components such as film-forming materials, pigments and fillers, additives and solvents. The insulating performance of the coating is improved by adding an appropriate amount of insulating materials. However, excessive use of insulating materials can easily lead to the problem that the insulating materials cannot be evenly dispersed with the coating matrix resin and pigments and fillers. Too little insulating material can easily lead to poor insulating performance of the coating, which in turn affects the application of the insulating coating. Summary of the Invention

[0004] In order to improve the dispersibility problem of water-based insulating coatings while maintaining good insulating properties of the coatings, the present application provides a water-based insulating coating and a preparation method thereof.

[0005] In a first aspect, the present application provides a water-based insulating coating, which adopts the following technical solution:

[0006] A water-based insulating coating comprises a component A and a component B, wherein the mass ratio of the components A to B is (7-9):1; the component A comprises the following raw materials in parts by weight: 100-150 parts of deionized water, 3-8 parts of bentonite, 3-8 parts of fumed silica, 40-80 parts of titanium dioxide, 90-110 parts of barium sulfate, 40-60 parts of mica powder, 60-80 parts of zinc phosphate, 40-60 parts of feldspar powder, 400-500 parts of epoxy emulsion, 3-5 parts of a substrate wetting agent, and 30-80 parts of a dispersant; the component B comprises the following raw materials in parts by weight: 40-60 parts of a curing agent and 40-60 parts of a solvent, and the dispersant comprises a sulfonate dispersant and a polycarboxylate dispersant.

[0007] By adopting the above technical solution, fumed silica has a high specific surface area and low conductivity, and titanium dioxide has excellent optical properties and chemical stability, which can increase the volume resistance of the coating and improve the insulating properties of the coating. Barium sulfate has a high resistivity, is non-conductive and has a high density, which can improve the good filling effect, increase the thickness and density of the coating, and thus improve the insulating properties of the coating. Mica powder has a flaky physical structure and can form a physical barrier to hinder the transfer of charge; zinc phosphate can form a non-conductive network structure in the coating, thereby increasing the resistance of the coating and providing corrosion protection; feldspar powder can utilize low conductivity and chemical inertness to increase the thickness of the coating, reduce the penetration of current, and thus improve the insulating properties of the coating. This application reduces the penetration of current by utilizing the different insulating properties of multiple insulating materials, so that the coating can maintain good insulating properties, while reducing the disadvantages of excessive use of a single insulating material and a single performance.

[0008] Bentonite and fumed silica increase coating viscosity, reduce filler sedimentation and delamination in the coating system, and reduce dripping and running of the coating on the substrate surface, thereby improving coating uniformity and adhesion. Fumed silica strengthens the coating's cohesion and forms a three-dimensional network structure within the coating system, making the coating tougher and reducing crack formation.

[0009] A sulfonate dispersant and a polycarboxylate dispersant are compounded and added to the coating as dispersants. The electrostatic effect of the sulfonate is used to give the surface charge of the filler particles in the coating system. The polycarboxylate dispersant can provide both electrostatic and steric hindrance. The combination of the two can enhance the stabilizing effect of charge dispersion, reduce the reaggregation of filler particles due to mutual attraction, reduce the phenomenon of particle agglomeration in the coating system, and improve the dispersibility of the coating system.

[0010] Preferably, the raw materials of component A of the water-based insulating coating further include the following components in parts by weight: 1-5 parts of a defoaming agent, 1-3 parts of a bactericide, 8-12 parts of an anti-flash rust agent, and 1-5 parts of a thickener.

[0011] Preferably, the sulfonate dispersant comprises the following components in parts by weight: 10-20 parts of sodium lignin sulfonate, 0.3-0.5 parts of initiator, 3-5 parts of polyethylene glycol monomethyl ether acrylate, and 5-8 parts of dimethylaminoethyl acrylate.

[0012] By adopting the above technical solution, sodium lignin sulfonate is a natural anionic dispersant that can better disperse filler particles and reduce particle agglomeration in coatings. The polyethylene glycol segments in the polyethylene glycol monomethyl ether acrylate macromolecular chain dissolve and extend in water, exerting a steric hindrance effect, improving the dispersibility and dispersion stability of the coating. Dimethylaminoethyl acrylate contains amino groups that can adsorb on the surface of the coating substrate while also dissolving and dispersing in water, thereby achieving a dynamic equilibrium and promoting the uniform dispersion of the various components in the coating, forming a strong, uniform coating on the substrate surface. The sulfonate dispersant generated by the synergistic free radical polymerization reaction initiated by the initiator has a stable dispersion effect in the coating system, further reducing particle agglomeration.

[0013] Preferably, the preparation method of the sulfonate dispersant comprises the following specific steps: dissolving and mixing sodium lignin sulfonate, polyethylene glycol monomethyl ether acrylate, dimethylaminoethyl acrylate and an initiator, heating to 70-80° C. under nitrogen protection for reaction, and then cooling and evaporating to remove water vapor to obtain a sulfonate dispersant.

[0014] Preferably, the dispersant further comprises polyurethane microcapsules, and the mass ratio of the polyurethane microcapsules, the sulfonate dispersant and the polycarboxylate dispersant is (0.3-0.5):1:1.

[0015] By adopting the above technical solution, polyurethane microcapsules are added to the coating system. When the coating is scratched and cracked by external forces, the polyurethane reacts with the intruding water molecules, forming cross-linked macromolecules at the cracked coating area and solidifying, thereby repairing the crack and improving the coating's self-healing ability. Furthermore, compounding the polyurethane microcapsules with sulfonate dispersants and polycarboxylate dispersants promotes uniform dispersion of the polyurethane microcapsules in the coating system, further improving the uniformity of the coating's self-healing effect and reducing the occurrence of coating cracking.

[0016] Preferably, the core-to-wall ratio of the polyurethane microcapsules is 0.5-0.8, wherein the wall material is carboxymethyl cellulose, and the core material comprises the following raw materials in parts by weight: 30-40 parts of polyoxypropylene polyol, 50-60 parts of isocyanate, and 1-3 parts of 2,2-dihydroxymethylpropionic acid.

[0017] By adopting the above technical solution and using biodegradable carboxymethyl cellulose as a wall material, polyurethane microcapsules are more easily dispersed in water-based coatings. The carboxyl groups of carboxymethyl cellulose provide a negative charge, preventing aggregation between polyurethane microcapsules and improving their dispersibility. Furthermore, during normal use of the coating, the carboxymethyl cellulose wall material ensures good stability of the polyurethane microcapsules. The high surface activity of carboxymethyl cellulose aids in particle dispersion within the coating system, improves adhesion between the coating and the substrate, and reduces shedding and cracking of the coating.

[0018] Preferably, the preparation method of the polyurethane microcapsules comprises the following specific steps: dissolving carboxymethyl cellulose in advance to form a wall material solution, dissolving and mixing polyoxypropylene polyol and isocyanate, heating and reacting, then adding 2,2-dihydroxymethyl propionic acid and heating to 70-90° C. to continue the reaction to obtain an aqueous polyurethane emulsion, mixing the aqueous polyurethane emulsion and the wall material solution, stirring at high speed, and spray drying to obtain the polyurethane microcapsules.

[0019] In a second aspect, the present application provides a method for preparing a water-based insulating coating, which adopts the following technical solution:

[0020] A preparation method of a water-based insulating coating comprises the following specific steps: mixing deionized water, a dispersant, bentonite and fumed silica, dispersing at high speed, then adding titanium dioxide, barium sulfate, mica powder, zinc phosphate and feldspar powder and grinding them, and finally adding epoxy emulsion and a substrate wetting agent, mixing and stirring evenly to form component A; mixing a curing agent and a solvent to form component B, and mixing components A and B according to a proportion to form the water-based insulating coating.

[0021] By adopting this technical solution, the insulating properties of multiple insulating materials are utilized to improve the insulation performance of the coating, reducing the phenomenon of particle agglomeration caused by excessive use of a single insulating material. Furthermore, the combination of sulfonate and polycarboxylate dispersants improves the dispersion effect of the coating system and reduces the reagglomeration of dispersed particles in the coating system.

[0022] Preferably, deionized water, dispersant, defoamer, bentonite and fumed silica are mixed and dispersed at high speed, and then titanium dioxide, barium sulfate, mica powder, zinc phosphate and feldspar powder are added and ground, and finally epoxy emulsion, substrate wetting agent, bactericide, anti-flash rust agent and thickener are added and mixed, and stirred evenly to form component A; the curing agent and solvent are mixed to form component B, and components A and B are mixed according to the ratio to form a water-based insulating coating.

[0023] In summary, this application has the following beneficial effects:

[0024] 1. Because this application utilizes a composite of multiple insulating materials—fumed silica, titanium dioxide, barium sulfate, mica powder, zinc phosphate, and feldspar powder—it avoids the poor insulation performance of a single insulating material, improving the coating's insulation performance while also reducing the agglomeration that can occur when excessive amounts of a single insulating material are used, thereby enhancing the dispersibility of the coating system. The use of a composite of a sulfonate dispersant and a polycarboxylate dispersant enhances the stability of the particle dispersion, reduces particle agglomeration in the coating system, and improves coating uniformity.

[0025] 2. The polyurethane microcapsules used in this application, made with carboxymethyl cellulose as the wall material and polyurethane as the core material, can crosslink and cure with immersed water molecules at cracked areas of the coating, repairing the cracks and enhancing the coating's self-healing ability and crack resistance. The use of carboxymethyl cellulose can also improve the dispersion of the polyurethane microcapsules in the coating system and reduce aggregation between the polyurethane microcapsules. DETAILED DESCRIPTION

[0026] The present application is further described in detail below with reference to the embodiments.

[0027] The substrate wetting agent is the organosilicon wetting agent Greesol H87.

[0028] The flash rust inhibitor is NALZIN FA-179.

[0029] The defoaming agent is TEGO Foamex-810.

[0030] The epoxy emulsion is Banco2060H.

[0031] The curing agent is Banco901.

[0032] The solvent is ethylene glycol butyl ether.

[0033] The thickener is polyurethane thickener RM-12W.

[0034] The fungicide is MBS.

[0035] Preparation Example 1

[0036] The sulfonate dispersant comprises the following raw materials in parts by weight: 15 kg of sodium lignin sulfonate, 0.4 kg of initiator, 4 kg of polyethylene glycol monomethyl ether acrylate, and 7 kg of dimethylaminoethyl acrylate, wherein the initiator is benzoyl peroxide.

[0037] The preparation method of the sulfonate dispersant comprises the following specific steps:

[0038] Sodium lignin sulfonate, polyethylene glycol monomethyl ether acrylate, dimethylaminoethyl acrylate and an initiator are dissolved in deionized water in advance to form a sulfonate mixed solution with a sodium lignin sulfonate concentration of 1 mol / L. Then, under the protection of nitrogen, the mixture is heated to 75°C, reacted for 4 hours, cooled to room temperature, and the water is evaporated to obtain a sulfonate-type dispersant.

[0039] Preparation Example 2

[0040] The difference between Preparation Example 2 and Preparation Example 1 is that the amount of sodium lignin sulfonate used in the sulfonate type dispersant raw material is 10 kg, the amount of initiator used is 0.3 kg, the amount of polyethylene glycol monomethyl ether acrylate used is 3 kg, and the amount of dimethylaminoethyl acrylate used is 5 kg.

[0041] Preparation Example 3

[0042] The difference between Preparation Example 3 and Preparation Example 1 is that the amount of sodium lignin sulfonate used in the sulfonate type dispersant raw material is 20 kg, the amount of initiator used is 0.5 kg, the amount of polyethylene glycol monomethyl ether acrylate used is 5 kg, and the amount of dimethylaminoethyl acrylate used is 8 kg.

[0043] Preparation Example 4

[0044] The polyurethane microcapsules include a core material and a wall material, wherein the mass ratio of the core material to the wall material is 0.7. The wall material is carboxymethyl cellulose, and the core material comprises the following raw materials in parts by weight: 35 kg of polyoxypropylene polyol, 55 kg of isocyanate, and 2 kg of 2,2-dimethylolpropionic acid. The isocyanate is hexamethylene diisocyanate, and the polyoxypropylene polyol is polyoxypropylene glycol DL-400.

[0045] The preparation method of polyurethane microcapsules comprises the following specific steps:

[0046] After dehydrating the polyoxypropylene polyol, the mixture was mixed and dissolved with isocyanate, heated to 60°C and reacted for 1 hour, and then 2,2-dihydroxymethylpropionic acid was added and heated to 80°C and reacted for 3 hours, and vacuum degassing was performed to obtain an aqueous polyurethane emulsion; then, carboxymethyl cellulose was dissolved in dichloromethane to form a wall material solution, and the aqueous polyurethane emulsion and the wall material solution were mixed, stirred at a speed of 2000 rpm for 10 minutes, and spray-dried to obtain polyurethane microcapsules.

[0047] Preparation Example 5

[0048] The difference between Preparation Example 5 and Preparation Example 4 is that the amount of polyoxypropylene polyol used in the polyurethane microcapsule core material is 30 kg, the amount of isocyanate used is 50 kg, and the amount of 2,2-dimethylolpropionic acid used is 1 kg.

[0049] Preparation Example 6

[0050] The difference between Preparation Example 6 and Preparation Example 4 is that the amount of polyoxypropylene polyol used in the polyurethane microcapsule core material is 40 kg, the amount of isocyanate used is 60 kg, and the amount of 2,2-dihydroxymethylpropionic acid used is 3 kg.

[0051] Preparation Example 7

[0052] The difference between Preparation Example 7 and Preparation Example 4 is that an equal amount of polyether diol is used in the raw material of the polyurethane microcapsule core material instead of polyoxypropylene polyol, wherein the molecular weight of the polyether diol is 4000. Example Example

[0053] This embodiment provides a water-based insulating coating, comprising component A and component B, wherein the mass ratio of component A to component B is 8:1. Component A comprises the following raw materials in parts by weight: 130 kg of deionized water, 5 kg of bentonite, 5 kg of fumed silica, 60 kg of titanium dioxide, 100 kg of barium sulfate, 50 kg of mica powder, 70 kg of zinc phosphate, 50 kg of feldspar powder, 450 kg of epoxy emulsion, 4 kg of a substrate wetting agent, and 55 kg of a dispersant. The dispersant is a mixture of a polycarboxylate dispersant and a sulfonate dispersant, wherein the mass ratio of the polycarboxylate dispersant to the sulfonate dispersant is 1:1. The polycarboxylate dispersant is sodium polyaspartate (PASP) purchased from Shandong Taihe Science and Technology Co., Ltd., and the sulfonate dispersant is sodium dodecylbenzenesulfonate.

[0054] The preparation method of the water-based insulating coating comprises the following specific steps:

[0055] Deionized water, dispersant, bentonite and fumed silica are mixed and dispersed at a speed of 500 rpm for 10 minutes. Titanium dioxide, barium sulfate, mica powder, zinc phosphate and feldspar powder are then added and dispersed for another 10 minutes to form a mixture. The mixture is then ground to a particle size of ≤5 μm. Finally, epoxy emulsion and substrate wetting agent are added and mixed, and the mixture is stirred evenly to form component A. The curing agent and solvent are mixed to form component B. Components A and B are mixed evenly according to the ratio to form a water-based insulating coating. Example

[0056] The difference between Example 2 and Example 1 is that the mass ratio of component A to component B in the water-based insulating coating is 7:1. Example

[0057] The difference between Example 3 and Example 1 is that the mass ratio of component A to component B in the water-based insulating coating is 9:1. Example

[0058] The difference between Example 4 and Example 1 is that the raw materials of component A of the water-based insulating coating also include 3 kg of defoaming agent, 2 kg of bactericide, 10 kg of anti-flash rust agent, and 3 kg of thickener.

[0059] The preparation method of the water-based insulating coating comprises the following specific steps:

[0060] Deionized water, dispersant, defoamer, bentonite and fumed silica are mixed and dispersed at a speed of 500 rpm for 10 minutes. Titanium dioxide, barium sulfate, mica powder, zinc phosphate and feldspar powder are then added and dispersed for another 10 minutes to form a mixture. The mixture is then ground to a particle size of ≤5 μm. Finally, epoxy emulsion, substrate wetting agent, bactericide, anti-flash rust agent and thickener are added and mixed, and stirred evenly to form component A. The curing agent and solvent are mixed to form component B. Components A and B are evenly mixed according to the ratio to form a water-based insulating coating. Example

[0061] The difference between Example 5 and Example 4 is that the raw materials of component A of the water-based insulating coating are

[0062] The usage of deionized water is 100kg, the usage of bentonite is 3kg, the usage of fumed silica is 8kg, the usage of titanium dioxide is 40kg, the usage of barium sulfate is 90kg, the usage of mica powder is 60kg, the usage of zinc phosphate is 60kg, the usage of feldspar powder is 60kg, the usage of epoxy emulsion is 400kg, the usage of substrate wetting agent is 5kg, the usage of dispersant is 30kg, the usage of defoaming agent is 1kg, the usage of fungicide is 3kg, the usage of anti-flash rust agent is 12kg, and the usage of thickener is 1kg. Example

[0063] The difference between Example 6 and Example 4 is that the amount of deionized water used in the raw materials of component A of the water-based insulating coating is 150 kg, the amount of bentonite used is 8 kg, the amount of fumed silica used is 3 kg, the amount of titanium dioxide used is 80 kg, the amount of barium sulfate used is 110 kg, the amount of mica powder used is 40 kg, the amount of zinc phosphate used is 80 kg, the amount of feldspar powder used is 40 kg, the amount of epoxy emulsion used is 500 kg, the amount of substrate wetting agent used is 3 kg, the amount of dispersant used is 80 kg, the amount of defoaming agent used is 5 kg, the amount of bactericide used is 1 kg, the amount of anti-flash rust agent used is 8 kg, and the amount of thickener used is 5 kg. Example

[0064] The difference between Example 7 and Example 1 is that the sulfonate dispersant in the raw material dispersant of component A of the water-based insulating coating is derived from Preparation Example 1. Example

[0065] Example 8 differs from Example 1 in that the sulfonate dispersant in the raw material dispersant of component A of the water-based insulating coating comes from Preparation Example 2. Example

[0066] The difference between Example 9 and Example 1 is that the sulfonate dispersant in the raw material dispersant of component A of the water-based insulating coating is derived from Preparation Example 3. Example

[0067] The difference between Example 10 and Example 7 is that the raw material dispersant of component A of the water-based insulating coating also includes polyurethane microcapsules, wherein the polyurethane microcapsules are derived from Preparation Example 4, and the mass ratio of the polyurethane microcapsules, sulfonate dispersant and polycarboxylate dispersant is 0.4:1:1. Example

[0068] The difference between Example 11 and Example 7 is that the polyurethane microcapsules in the raw material dispersant of component A of the water-based insulating coating are derived from Preparation Example 5. Example

[0069] The difference between Example 12 and Example 7 is that the polyurethane microcapsules in the raw material dispersant of component A of the water-based insulating coating are derived from Preparation Example 6. Example

[0070] The difference between Example 13 and Example 7 is that the polyurethane microcapsules in the raw material dispersant of component A of the water-based insulating coating are derived from Preparation Example 7.

[0071] Comparative Example 1

[0072] The difference between Comparative Example 1 and Example 1 is that no polycarboxylate dispersant is used in the raw material dispersant of component A of the water-based insulating coating.

[0073] Comparative Example 2

[0074] The difference between Comparative Example 2 and Example 1 is that no dispersant is used in the raw materials of component A of the water-based insulating coating.

[0075] Comparative Example 3

[0076] The difference between Comparative Example 3 and Example 1 is that an equal amount of mica powder is used in the raw materials of component A of the water-based insulating coating to replace fumed silica, titanium dioxide, barium sulfate, zinc phosphate and feldspar powder.

[0077] The following performance tests were performed on the water-based insulating coatings provided in Examples 1-13 and Comparative Examples 1-3 of the present application. The specific test results are shown in Table 1.

[0078] 1. Insulation performance

[0079] The volume resistivity of the prepared paint is detected according to the standard of GB / T 31838.2-2019 “Solid Insulating Material Dielectric and Resistive Properties Part 2”; the electrical strength of the prepared paint is detected according to the standard of HG / T 3330-2012 “Test Method for Breakdown Strength of Insulating Paint Film”.

[0080] II. Self-repairing ability

[0081] The self-repairing time of the prepared paint for a crack of about 0.5 mm is detected according to the standard of JC / T 975-2005 “Waterproof Coatings for Roads and Bridges”.

[0082] III. Coating appearance

[0083] The prepared paint is coated on a sandblasted plate, and the average thickness of the coating is 0.2 mm. The coating is observed for smoothness after being placed in a constant temperature oven at 25°C for 48 hours.

[0084] Table 1: Performance detection result data table

[0085] Example <![CDATA[体积电阻率(*10 12 / Ω•m)]]> Electric strength (MV / m) Self-repair time (s) Coating appearance Example 1 1.23 33.4 21 Smooth Example 2 1.10 32.5 23 / Example 3 1.21 33.1 / / Example 4 1.35 35.2 / / Example 5 1.30 34.1 / / Example 6 1.33 34.8 / / Example 7 1.63 39.8 / Smooth and smooth, good self-leveling effect Example 8 1.59 38.6 / Smooth and smooth, good self-leveling effect Example 9 1.62 39.3 / Smooth and smooth, good self-leveling effect Example 10 1.89 43.1 11 / Example 11 1.81 42.5 13 / Example 12 1.86 42.7 12 / Example 13 1.74 41.9 15 / Comparative Example 1 1.05 30.8 40 The surface is smooth but slightly Comparative Example 2 0.98 29.7 60 Rough, uneven surface Comparative Example 3 0.05 17.6 Cracks cannot be repaired The granular feel of the agglomerates is obvious

[0086] It can be known from the performance detection results that the water-based insulating paint prepared by the application can maintain good insulating performance under the synergistic effect of various components, and the dispersibility of each component in the paint system is good. In Examples 1-6, the use amounts of the components are different, and the comprehensive performance of Example 4 is more optimal.

[0087] In Examples 7-9, the sulfonate dispersant synthesized from sodium lignosulfonate, polyethylene glycol monomethyl ether acrylate and dimethylaminoethyl acrylate is used. It can be known from the performance detection results that the coating surface is smoother and more uniform, and the self-leveling effect is better, which further indicates that the sulfonate dispersant prepared by the application added to the paint system can promote better and more stable dispersibility of the paint.

[0088] In Examples 10-12, polyurethane microcapsules are further added to the dispersant. It can be known from the performance detection results that the self-repairing ability of the coating is obviously improved, which can promote the healing of cracks and reduce the expansion of coating cracks, thereby improving the stability of the coating. It can be known by comparing Example 13 with Example 10 that the polyurethane microcapsules prepared by using different polyols have different promoting effects on the self-repairing ability of the coating. The self-repairing ability of the coating in Example 13 using polyether diol decreases, which may be because polyoxypropylene polyol has better flexibility compared with polyether polyol, so that the prepared polyurethane has stronger flexibility, thereby improving the anti-cracking performance of the coating, reducing the expansion of coating cracks, and improving the self-repairing ability of the coating.

[0089] By comparing Comparative Examples 1-3 with Example 1, it can be seen that Comparative Example 1 uses a single dispersant, while Comparative Example 2 does not use a dispersant. The performance test results show that the dispersion effect of the coating is poor. This may be because after the particles are dispersed by physical dispersion or a single dispersant, the particles in the coating system re-aggregate during the storage of the coating, resulting in agglomeration. In Comparative Example 3, a single mica powder is used to replace other types of insulating materials. The performance test results show that the insulation performance and dispersion effect of the coating are greatly reduced, the coating has a noticeable granular feel, and it is impossible to form a complete coating. This further illustrates that the present application uses multiple types of insulating materials to improve the performance of the coating in all directions, while maintaining good dispersion performance in the coating system.

[0090] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A water-based insulating coating, characterized in that: The invention comprises component A and component B, wherein the mass ratio of component A to component B is (7-9):1; component A comprises the following raw materials in parts by weight: 100-150 parts of deionized water, 3-8 parts of bentonite, 3-8 parts of fumed silica, 40-80 parts of titanium dioxide, 90-110 parts of barium sulfate, 40-60 parts of mica powder, 60-80 parts of zinc phosphate, 40-60 parts of feldspar powder, 400-500 parts of epoxy emulsion, 3-5 parts of substrate wetting agent, and 30-80 parts of dispersant; component B comprises the following raw materials in parts by weight: 40-60 parts of curing agent and 40-60 parts of solvent, and the dispersant comprises a sulfonate dispersant and a polycarboxylate dispersant.

2. The water-based insulating coating according to claim 1, characterized in that: The raw materials of component A of the water-based insulating coating further include the following components in parts by weight: 1-5 parts of a defoaming agent, 1-3 parts of a fungicide, 8-12 parts of an anti-flash rust agent, and 1-5 parts of a thickener.

3. The water-based insulating coating according to claim 1, characterized in that: The sulfonate dispersant comprises the following components in parts by weight: 10-20 parts of sodium lignin sulfonate, 0.3-0.5 parts of initiator, 3-5 parts of polyethylene glycol monomethyl ether acrylate, and 5-8 parts of dimethylaminoethyl acrylate.

4. The water-based insulating coating according to claim 3, characterized in that: The preparation method of the sulfonate dispersant comprises the following specific steps: dissolving and mixing sodium lignin sulfonate, polyethylene glycol monomethyl ether acrylate, dimethylaminoethyl acrylate and an initiator, heating to 70-80° C. under nitrogen protection for reaction, and then cooling and evaporating to remove water vapor to obtain the sulfonate dispersant.

5. The water-based insulating coating according to claim 1, characterized in that: The dispersant further comprises polyurethane microcapsules, and the mass ratio of the polyurethane microcapsules, the sulfonate dispersant and the polycarboxylate dispersant is (0.3-0.5):1:

1.

6. The water-based insulating coating according to claim 5, characterized in that: The core-to-wall ratio of the polyurethane microcapsules is 0.5-0.8, wherein the wall material is carboxymethyl cellulose, and the core material comprises the following raw materials in parts by weight: 30-40 parts of polyoxypropylene polyol, 50-60 parts of isocyanate, and 1-3 parts of 2,2-dihydroxymethylpropionic acid.

7. The water-based insulating coating according to claim 6, characterized in that: The preparation method of the polyurethane microcapsules comprises the following specific steps: dissolving carboxymethyl cellulose in advance to form a wall material solution, dissolving and mixing polyoxypropylene polyol and isocyanate, heating and reacting, then adding 2,2-dihydroxymethyl propionic acid and heating to 70-90° C. to continue the reaction to obtain an aqueous polyurethane emulsion, mixing the aqueous polyurethane emulsion and the wall material solution, stirring at high speed, and spray drying to obtain the polyurethane microcapsules.

8. A method for preparing a water-based insulating coating according to any one of claims 1 to 7, characterized in that: The method comprises the following specific steps: mixing deionized water, a dispersant, bentonite and fumed silica, dispersing the mixture at high speed, then adding titanium dioxide, barium sulfate, mica powder, zinc phosphate and feldspar powder and grinding the mixture, and finally adding epoxy emulsion and a substrate wetting agent, mixing the mixture and stirring the mixture evenly to form component A; mixing a curing agent and a solvent to form component B, and mixing components A and B according to a proportion to form a water-based insulating coating.

9. The method for preparing the water-based insulating coating according to claim 8, characterized in that: Deionized water, dispersant, defoaming agent, bentonite and fumed silica are mixed and dispersed at high speed. Then titanium dioxide, barium sulfate, mica powder, zinc phosphate and feldspar powder are added and ground. Finally, epoxy emulsion, substrate wetting agent, bactericide, anti-flash rust agent and thickener are added and mixed. The mixture is stirred evenly to form component A. The curing agent and solvent are mixed to form component B. Components A and B are mixed according to the ratio to form a water-based insulating coating.