Acrylic acid waterproof coating suitable for construction in condensation environment and preparation method of acrylic acid waterproof coating

Abstract

The invention discloses an acrylic acid waterproof coating suitable for construction in a condensation environment and a preparation method of the acrylic acid waterproof coating. The acrylic waterproof coating is prepared from the following raw materials: 30 to 60 parts of waterborne acrylic emulsion, 1 to 6 parts of fumed silica, 5 to 10 parts of polyvinyl alcohol aqueous solution with the mass percent concentration of 5 to 10 percent, 1 to 5 parts of antifreezing agent composition, 3 to 5 parts of cosolvent, 1 to 3 parts of dispersing agent, 0.1 to 0.5 part of defoaming agent, 10 to 15 parts of pigment, 5 to 10 parts of filler, 0.1 to 0.5 part of thickening agent, 0.1 to 0.4 part of wetting agent and 8 to 20 parts of water, wherein the anti-freezing agent composition is composed of a component A and a component B, and the mass ratio of the component A to the component B is 1: (0.5-1.5); wherein the component A is selected from one or two of betaine and choline chloride in any proportion, and the component B is selected from one or two of ethylene glycol and propylene glycol in any proportion.

Description

Technical Field

[0001] This invention belongs to the field of polymer coating technology, specifically relating to an acrylic waterproof coating that can be applied and cured in a low-temperature, high-humidity condensation environment and its preparation method. Background Technology

[0002] Condensation is a common physical phenomenon that occurs when water vapor in the air condenses on the surface of an object, forming a visible or invisible film of liquid water, when the surface temperature is lower than the dew point temperature of the surrounding air. Condensation is particularly prevalent in high-humidity environments or areas with drastic temperature fluctuations, such as underground pipe corridors, building roofs, and areas with large diurnal temperature variations. Water-based acrylic coatings require water to evaporate before forming a continuous film on the substrate surface. If condensation (water film) exists on the substrate, or if the air humidity is close to saturation (temperature close to the dew point) during application, the coating will adhere to the water film, causing blistering and peeling. Furthermore, the evaporated water cannot be expelled in time, resulting in a loose coating structure or microscopic defects. Therefore, most commercially available acrylic coatings explicitly specify that the substrate temperature must be at least 3°C ​​above the dew point before application, and also specify the maximum relative humidity of the environment.

[0003] To address the challenges of construction in condensation environments, existing technologies primarily focus on passive adaptation through environmental intervention. For example, in the power or electrical equipment sector, common anti-condensation strategies involve installing heaters to raise the ambient temperature and create a temperature difference with the dew point, or using sealing and dehumidification equipment to reduce absolute humidity. These methods are limited by high energy consumption, complex equipment, and inability to be implemented on open or large-area substrate surfaces. A fundamental solution may lie in improvements to acrylic coatings.

[0004] Existing technologies for improving the performance of acrylic coatings mainly focus on enhancing weather resistance and elasticity, such as the acrylic waterproof coatings disclosed in CN120737679A and CN114381178A; however, there is little discussion on how to adapt to the construction and curing environment of condensation. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an acrylic waterproof coating suitable for application in condensation environments and its preparation method. The acrylic waterproof coating of this invention exhibits strong adhesion to the substrate and can be directly applied and cured in low-temperature, high-humidity condensation environments without requiring additional equipment or environmental intervention. Therefore, the acrylic waterproof coating of this invention has a wide spraying temperature range, making it particularly suitable for waterproofing the exterior surfaces of large buildings and equipment in open condensation environments.

[0006] Therefore, in a first aspect, the present invention provides an acrylic waterproof coating suitable for application in condensing environments, wherein the raw material composition, by weight, is as follows:

[0007] The composition includes 30-60 parts of water-based acrylic emulsion, 1-6 parts of fumed silica, 5-10 parts of a 5%-10% (w / w) polyvinyl alcohol aqueous solution, 1-5 parts of antifreeze composition, 3-5 parts of cosolvent, 1-3 parts of dispersant, 0.1-0.5 parts of defoamer, 10-15 parts of pigment, 5-10 parts of filler, 0.1-0.5 parts of thickener, 0.1-0.4 parts of wetting agent, and 8-20 parts of water.

[0008] The antifreeze composition comprises component A and component B, with a mass ratio of component A to component B of 1:0.5-1.5; component A is selected from one or any proportion of betaine and choline chloride, and component B is selected from one or any proportion of ethylene glycol and propylene glycol.

[0009] As a preferred embodiment, the acrylic waterproof coating adapted for application in condensation environments provided by the present invention has the following raw material composition by weight:

[0010] The composition comprises 40-55 parts of aqueous acrylic emulsion, 2-4 parts of fumed silica, 8-10 parts of a 5%-10% (w / w) polyvinyl alcohol aqueous solution, 3-5 parts of the antifreeze composition, 3-4 parts of cosolvent, 2-3 parts of dispersant, 0.2-0.3 parts of defoamer, 10-12 parts of pigment, 7-9 parts of filler, 0.2-0.3 parts of wetting agent, 0.2-0.5 parts of thickener, and 12-20 parts of water.

[0011] Preferably, the aqueous acrylic emulsion has a polymer molecular weight of 5,000-40,000 and is selected from at least one of polyacrylic acid emulsion, copolymer acrylic acid emulsion, polyurethane-modified acrylic acid emulsion, and silicone-modified acrylic acid emulsion.

[0012] More preferably, the aqueous acrylic emulsion is a polyurethane acrylic emulsion with a molecular weight of 15,000-30,000.

[0013] Preferably, the specific surface area of ​​the fumed silica is 150-300 m² / g. 2 / g, particle size ≤600μm.

[0014] More preferably, the specific surface area of ​​the fumed silica is 150-250 m² / g. 2 / g, particle size ≤300μm.

[0015] Preferably, the mass percentage concentration of the polyvinyl alcohol aqueous solution is 8%-10%.

[0016] Preferably, the polyvinyl alcohol aqueous solution is prepared by dispersing one or more of 1788, 1799, 2480 and 2488 with a degree of polymerization of 1500-3000 in water.

[0017] More preferably, the polyvinyl alcohol aqueous solution is prepared by dispersing one or two of polymers with a degree of polymerization of 2400, 2480 and 2488, in water in any proportion.

[0018] Most preferably, the polyvinyl alcohol aqueous solution is prepared by dispersing 2480 polyvinyl alcohol with a degree of polymerization of 2400 in hot water and stirring.

[0019] Preferably, the co-solvent is selected from one or two of dipropylene glycol butyl ether and dipropylene glycol methyl ether in any proportion; more preferably, it is dipropylene glycol butyl ether.

[0020] The dispersant can be anionic, cationic, or nonionic dispersants commonly used in the art for stabilizing and dispersing pigments. As a preferred and exemplary embodiment, the dispersant is SN-1792 manufactured by BYK AG, Germany.

[0021] Preferably, the defoamer is selected from one or more of mineral oil defoamers, silicone defoamers, polyether defoamers, and alkynyl alcohol defoamers in any proportion.

[0022] As a preferred and exemplary embodiment, the defoamer is a polyether-based defoamer.

[0023] In this invention, the wetting agent is used to reduce the surface tension between the coating and the substrate, thereby improving the wettability of the coating on low surface energy substrates. Preferably, the wetting agent can be selected from one or more of silicone-based substrate wetting agents, anionic substrate wetting agents, and nonionic substrate wetting agents in any proportion. More preferably, the wetting agent is a silicone-based substrate wetting agent.

[0024] The wetting agent may be a commercially available product of the aforementioned wetting agent.

[0025] Preferably, the thickener is selected from one or more of acrylic associative thickeners, alkali-swellable thickeners, and cellulose ether thickeners in any proportion. More preferably, the thickener is an acrylic associative thickener.

[0026] The thickener may be a commercially available product of the aforementioned thickener.

[0027] Preferably, the pigment is selected from one or more of rutile titanium dioxide, anatase titanium dioxide, phthalocyanine pigments, iron oxide pigments, and organic carbon black in any proportion.

[0028] Preferably, the filler is selected from one or more of precipitated barium sulfate, mica powder, calcium carbonate and talc powder in any proportion.

[0029] Secondly, the present invention also provides a method for preparing the above-mentioned acrylic waterproof coating adapted for construction in condensation environments, comprising the following steps:

[0030] I. Prepare the raw materials according to the stated mass proportions;

[0031] II. Add the water in the specified mass fraction to a paint grinder equipped with a stirring device. While stirring, first add the fumed silica in the specified mass fraction and disperse it evenly. Then, add the dispersant, defoamer, pigment, and filler in the specified mass fraction in sequence. After mixing evenly, add zirconia beads and grind at 20-50°C until the fineness is 10-20μm. Filter to remove the zirconia beads and obtain the slurry.

[0032] III. Add the specified mass fraction of acrylic emulsion to a mixing device equipped with a stirring device, then add the slurry obtained in step II, then add the specified mass fraction of polyvinyl alcohol solution, stir until homogeneous, then add the specified mass fraction of antifreeze composition, cosolvent, wetting agent and thickener in sequence, stir until homogeneous, and the product is obtained.

[0033] Those skilled in the art should understand that in step II above, water, fumed silica, dispersant, defoamer, pigment and filler can be mixed evenly in a mixing device equipped with a stirring device, and then transferred to a grinding device equipped with grinding media (such as zirconia beads) for grinding.

[0034] Preferably, in step II, the mixture is stirred at a speed of 600-1000 r / min for 3-10 min to uniformly disperse fumed silica in the water.

[0035] Preferably, in step III, the stirring speed is 500-800 r / min.

[0036] In another aspect, the present invention also provides a construction process for the acrylic waterproof coating adapted to condensation environment construction, the process comprising: cleaning the surface of the metal substrate to be coated, spraying, rolling or brushing the acrylic waterproof coating on the surface of the metal substrate 2-3 times until the dry film thickness reaches 0.5-2.0 mm, and allowing it to dry naturally.

[0037] The acrylic waterproof coating adapted to condensation environments described in this invention can have its consistency adjusted by adding an appropriate amount of water during actual construction, depending on the process, such as spraying, roller coating, or brushing.

[0038] This invention employs an antifreeze composition consisting of component A, selected from betaine and / or choline chloride, and component B, selected from ethylene glycol and / or propylene glycol. This composition provides both antifreeze protection and wetting at the coating interface in low-temperature environments, while simultaneously solving problems such as sedimentation, icing, and cracking of the coating in low-temperature, high-humidity environments. Therefore, the acrylic waterproof coating of this invention, after being sprayed onto the substrate surface in a condensing environment, requires no special curing and can quickly cure into a film on the substrate surface. Furthermore, the acrylic waterproof coating of this invention, through the combined action of its components, exhibits high adhesion to the substrate, good hydrophobicity, and weather resistance after curing.

[0039] Of course, those skilled in the art will understand that, in order to enhance the waterproofing effect, a topcoat can be sprayed onto the surface of the acrylic waterproof coating formed by the present invention. Attached Figure Description

[0040] The present invention will be further described below with reference to the accompanying drawings.

[0041] Figure 1 This is a photograph taken 24 hours after the acrylic waterproof coating of Example 8 of the present invention was applied to a metal roof in a practical application example. Detailed Implementation

[0042] The present invention will be described below with reference to specific embodiments. Those skilled in the art will understand that these embodiments are for illustrative purposes only and do not limit the scope of the invention in any way.

[0043] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, all raw materials and reagents used in the following examples are commercially available products. The purchase details of some reagents and raw materials are as follows:

[0044] Waterborne acrylic emulsions: polyacrylic acid emulsions, copolymer acrylic acid emulsions, polyurethane-modified acrylic acid emulsions, silicone-modified acrylic acid emulsions, molecular weight 15,000-30,000; Supplier: Nanjing Xinhai Co., Ltd.

[0045] Fumed silica: specific surface area 150-250m² 2 / g, particle size ≤300 micrometers; supplier: Beijing Qianmen Chemical Raw Materials Co., Ltd.

[0046] Betaine, choline chloride, ethylene glycol, propylene glycol: Supplier: Shanghai McLean Technology Co., Ltd.

[0047] Polyvinyl alcohol: 2488 (degree of polymerization 2400), supplier: Beijing Qianmen Chemical Raw Materials Co., Ltd.

[0048] Dispersant: SN-1792, supplier: BYK Chemical Company.

[0049] Defoamer: HF3206, Supplier: Anshan Huihong New Material Chemical Co., Ltd.

[0050] Dipropylene glycol butyl ether: Supplier: Shanghai Tikham Industrial Co., Ltd.

[0051] Rutile titanium dioxide RCL-595: Supplier: Shenzhen Meililian Titanium Industry Co., Ltd.

[0052] Barium sulfate: Supplier: Sahaliben Chemical GmbH, Germany.

[0053] Wetting agent: Greesol F04, supplier: Yueyang Kaimen Waterborne Additives Co., Ltd.

[0054] Thickener: U-6029, Supplier: Puwei Group.

[0055] The 8% polyvinyl alcohol aqueous solution used in the following examples and / or comparative examples was prepared by the following method:

[0056] Add 8 parts by weight of polyvinyl alcohol to 92 parts by weight of water, soak for 3 hours, and then stir in a 60°C water bath for 1-2 hours to obtain the product.

[0057] Examples 1-10: An acrylic waterproof coating suitable for application in condensation environments

[0058] The acrylic waterproof coatings of Examples 1-10, with specific raw material compositions shown in Tables 1 and 2 (where 1 part by mass = 1 kg), were prepared through the following steps:

[0059] I. Prepare the raw materials according to the stated mass proportions;

[0060] II. Add the water in the specified mass fraction to a paint grinder equipped with a stirring device. First, add the fumed silica in the specified mass fraction at a speed of 800 r / min. Stir for 5 min to disperse evenly. Then, add the dispersant, defoamer, pigment, and filler in the specified mass fraction in sequence. Maintain the speed and mix evenly. Then, add zirconia beads and grind at 30°C until the fineness is 10-20 μm. Filter to remove the zirconia beads and obtain the slurry.

[0061] III. Add the specified mass fraction of acrylic emulsion to a dispersion tank, then add the slurry obtained in step II, then add the specified mass fraction of polyvinyl alcohol solution, stir at 600 r / min for 5 min, then add the specified mass fraction of antifreeze composition, cosolvent, wetting agent and thickener in sequence, stir for 10 min, and the product is obtained.

[0062]

[0063] Comparative Examples 1-10: An acrylic waterproof coating

[0064] The specific raw material composition of the acrylic waterproof coatings of Comparative Examples 1-10 is shown in Table 2 (where 1 part by mass = 1 kg); they were prepared by basically the same steps and processes as those in the above embodiments of the present invention.

[0065]

[0066] Test case

[0067] The acrylic waterproof coatings prepared in Examples 1-10 and Comparative Examples 1-10 were brushed onto smooth metal plates (cold-rolled steel plates) and then placed in an environmental test chamber (5±1℃, 85±5 RH%) to test the drying time of the acrylic coatings under condensation and low-temperature conditions and to visually observe the appearance of the dried coatings. After drying, the adhesion of the coatings was tested according to GB / T 9286-2021. The results are shown in Table 3.

[0068]

[0069] Practical application examples

[0070] The weather conditions on September 23, 2025 are as follows:

[0071] Cloudy turning foggy. Temperatures range from 13°C to 20°C. The minimum relative humidity during the day is 65%, while the maximum relative humidity at night reaches 95%.

[0072] At 2 PM that day, the acrylic coating prepared in Example 8 was used to apply a waterproof coating to a metal roof in Beijing, with two coats applied. Curing was carried out under natural conditions. On the day of application, the air humidity was high, and dew formed overnight on surfaces such as grass, metal roofs, and car windows. No dehumidification measures were taken after applying the acrylic waterproof coating of this invention; instead, it was allowed to dry naturally in the air. By the afternoon of September 24th (24 hours after application), the coating was completely dry, with a smooth surface and no peeling or cracking. Figure 1 .

[0073] The test results show that the acrylic waterproof coating of the present invention is fully adaptable to low temperature and high humidity condensation environment.

[0074] In summary, this invention provides an acrylic waterproof coating that can be applied and cured in low-temperature, high-humidity condensation environments and has strong adhesion to the substrate.

Claims

1. An acrylic waterproof coating suitable for application in condensation environments, comprising the following raw material components by weight: The composition includes 30-60 parts of water-based acrylic emulsion, 1-6 parts of fumed silica, 5-10 parts of a 5%-10% (w / w) polyvinyl alcohol aqueous solution, 1-5 parts of antifreeze composition, 3-5 parts of cosolvent, 1-3 parts of dispersant, 0.1-0.5 parts of defoamer, 10-15 parts of pigment, 5-10 parts of filler, 0.1-0.5 parts of thickener, 0.1-0.4 parts of wetting agent, and 8-20 parts of water. in, The antifreeze composition comprises component A and component B, with a mass ratio of component A to component B of 1:0.5-1.5; wherein component A is selected from one or any proportion of betaine and choline chloride, and component B is selected from one or any proportion of ethylene glycol and propylene glycol.

2. The acrylic waterproof coating according to claim 1, characterized in that, The raw material composition of the acrylic waterproof coating, by weight, is as follows: The composition comprises 40-55 parts of aqueous acrylic emulsion, 2-4 parts of fumed silica, 8-10 parts of a 5%-10% (w / w) polyvinyl alcohol aqueous solution, 3-5 parts of the antifreeze composition, 3-4 parts of cosolvent, 2-3 parts of dispersant, 0.2-0.3 parts of defoamer, 10-12 parts of pigment, 7-9 parts of filler, 0.2-0.3 parts of wetting agent, 0.2-0.5 parts of thickener, and 12-20 parts of water.

3. The acrylic waterproof coating according to claim 1 or 2, characterized in that, The aqueous acrylic emulsion has a polymer molecular weight of 5,000-40,000 and is selected from at least one of polyacrylic acid emulsion, copolymer acrylic acid emulsion, polyurethane modified acrylic acid emulsion, and silicone modified acrylic acid emulsion. More preferably, the aqueous acrylic emulsion is a polyurethane acrylic emulsion with a molecular weight of 15,000-30,000.

4. The acrylic waterproof coating according to claim 1 or 2, characterized in that, The specific surface area of ​​the fumed silica is 150-300 m². 2 / g, particle size ≤600μm; Preferably, the specific surface area of ​​the fumed silica is 150-250 m² / g. 2 / g, particle size ≤300μm.

5. The acrylic waterproof coating according to claim 1 or 2, characterized in that, The polyvinyl alcohol aqueous solution has a mass percentage concentration of 8%-10%; Preferably, the polyvinyl alcohol aqueous solution is prepared by dispersing one or more of 1788, 1799, 2480 and 2488 with a degree of polymerization of 1500-3000 in water. More preferably, the polyvinyl alcohol aqueous solution is prepared by dispersing one or two of polymerization degrees of 2400, 2480 and 2488, or any proportion thereof, in water; Most preferably, the polyvinyl alcohol aqueous solution is prepared by dispersing 2480 polyvinyl alcohol with a degree of polymerization of 2400 in hot water and stirring.

6. The acrylic waterproof coating according to claim 1 or 2, characterized in that, The co-solvent is selected from one or two of dipropylene glycol butyl ether and dipropylene glycol methyl ether in any proportion; more preferably, it is dipropylene glycol butyl ether. Preferably, the dispersant is selected from anionic dispersants, cationic dispersants, or nonionic dispersants; More preferably, the dispersant is SN-1792 manufactured by BYK AG, Germany; Preferably, the defoamer is selected from one or more of mineral oil defoamers, silicone defoamers, polyether defoamers, and alkynyl alcohol defoamers in any proportion; More preferably, the defoamer is a polyether-based defoamer; Preferably, the wetting agent is selected from one or more of the following: silicone-based substrate wetting agents, anionic substrate wetting agents, and nonionic substrate wetting agents; More preferably, the wetting agent is a silicone-based substrate wetting agent; Preferably, the thickener is selected from one or more of acrylic associative thickeners, alkali-swellable thickeners, and cellulose ether thickeners in any proportion; Preferably, the thickener is an acrylic associative thickener.

7. The acrylic waterproof coating according to claim 1 or 2, characterized in that, The pigment is selected from one or more of the following: rutile titanium dioxide, anatase titanium dioxide, phthalocyanine pigments, iron oxide pigments, and organic carbon black; Preferably, the filler is selected from one or more of precipitated barium sulfate, mica powder, calcium carbonate and talc powder in any proportion.

8. A method for preparing an acrylic waterproof coating suitable for application in condensation environments, as described in any one of claims 1 to 7, comprising the following steps: I. Prepare the raw materials according to the stated mass proportions; II. Add the water in the specified mass fraction to a paint grinder equipped with a stirring device. While stirring, first add the fumed silica in the specified mass fraction and disperse it evenly. Then, add the dispersant, defoamer, pigment, and filler in the specified mass fraction in sequence. After mixing evenly, add zirconia beads and grind at 20-50°C until the fineness is 10-20μm. Filter to remove the zirconia beads and obtain the slurry. III. Add the specified mass fraction of acrylic emulsion to a mixing device equipped with a stirring device, then add the slurry obtained in step II, then add the specified mass fraction of polyvinyl alcohol solution, stir until homogeneous, then add the specified mass fraction of antifreeze composition, cosolvent, wetting agent and thickener in sequence, stir until homogeneous, and the product is obtained.

9. The preparation method according to claim 8, characterized in that, In step II, the mixture is stirred at a speed of 600-1000 r / min for 3-10 min to uniformly disperse fumed silica in water. Preferably, in step III, the stirring speed is 500-800 r / min.

10. The construction process of the acrylic waterproof coating adapted to condensation environments according to any one of claims 1 to 7, or the acrylic waterproof coating adapted to condensation environments directly obtained by the preparation method according to claim 8 or 9, comprises: Clean the surface of the metal substrate to be coated, and spray, roll, or brush the acrylic waterproof coating onto the surface of the metal substrate 2-3 times until the dry film thickness reaches 0.5-2.0 mm, and allow it to dry naturally.

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