Water-based coating composition as well as preparation method and application thereof

Abstract

The invention discloses a water-based coating composition as well as a preparation method and application thereof, and relates to the technical field of coatings. The water-based coating composition comprises an emulsion, a thickening agent, a slow-release auxiliary agent, a nano layered silicic acid mildew preventive, a filler, an auxiliary agent and water, the thickening agent comprises first cellulose and second cellulose; the molecular weights of the first cellulose and the second cellulose are different; the slow-release auxiliary agent comprises at least one of hexadecanol, glyceryl stearate, octadecanoic acid, octadecylamine and a polyethylene glycol-polylactic acid block copolymer. According to the invention, the nano layered silicic acid mildew preventive is introduced, and is matched with the specific thickening agent and the slow-release auxiliary agent to construct a slow-release network, so that a mildew-proof system with a slow-release effect is formed, long-acting mildew prevention is realized, and the problem of environmental protection caused by a traditional chemical mildew preventive is solved.

Description

Technical Field

[0001] This invention relates to the field of coating technology, and in particular to a water-based coating composition, its preparation method, and its application. Background Technology

[0002] In the field of architectural coatings, water-based coatings have become the mainstream product in the market due to their advantages such as environmental friendliness and low volatile organic compound (VOC) emissions. However, water-based coatings face the problem of insufficient anti-mold performance in practical applications, especially in humid environments or during long-term use, where they are prone to mold growth, leading to discoloration and mold on the walls, affecting aesthetics and service life.

[0003] Currently, the most common method to improve the anti-mildew performance of water-based coatings is to add chemical anti-mildew agents, such as BCM (2-(thiocyanomethylthio)benzothiazole), OIT (isothiazolinones), IPBC (iodopropynylcarbamate), and ZPT (zinc pyrithione). However, these anti-mildew agents are irritating and toxic to humans and the environment, have poor environmental friendliness, and the small molecules in these agents are prone to migration and precipitation, leading to problems such as short anti-mildew time, paint film discoloration (reduced whiteness), and poor thermal storage stability. They also have poor workability and durability, which limits their application in water-based coatings. To ensure the environmental friendliness of coatings, existing technology discloses an antibacterial and environmentally friendly latex paint, which describes how adding a chitosan complex containing a C3N4 / TiO2 composite and modified porous chitosan microspheres cross-linked can improve antibacterial and anti-mildew performance. Although this method abandons traditional anti-mildew agents and improves environmental friendliness, it has significant shortcomings in terms of antibacterial and anti-mildew mechanisms and workability. Specifically, its antibacterial and antifungal mechanism mainly relies on chitosan complex, lacking a long-lasting sustained-release design, which may lead to the antifungal effect weakening over time, and the durability of the antifungal effect is still insufficient. Summary of the Invention

[0004] The present invention aims to at least solve one of the aforementioned technical problems existing in the prior art. Therefore, the object of the present invention is to provide a water-based coating composition that, by introducing a nano-layered silicate antifungal agent, combined with specific thickeners and slow-release additives to construct a slow-release network, forms an antifungal system with a slow-release effect, achieving long-lasting antifungal protection and solving the environmental problems caused by traditional chemical antifungal agents.

[0005] A second aspect of the present invention is to provide a method for preparing a water-based coating composition.

[0006] A third aspect of the present invention is to provide an anti-mildew coating.

[0007] A fourth aspect of the present invention is to provide an application of a water-based coating composition and an anti-mildew coating in the construction field.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A first aspect of the present invention provides an aqueous coating composition comprising an emulsion, a thickener, a slow-release agent, a nano-layered silicate antifungal agent, a filler, an additive, and water; The thickener comprises a first cellulose and a second cellulose; the first cellulose and the second cellulose have different molecular weights; the sustained-release agent comprises at least one of hexadecyl alcohol, glyceryl stearate, octadecanoic acid, octadecylamine, and polyethylene glycol-polylactic acid block copolymer.

[0009] The water-based coating composition of the present invention introduces a nano-layered silicate antifungal agent and combines it with a specific thickener and a slow-release agent to construct an antifungal system with a slow-release effect. Through the network structure formed by cellulose of different molecular weights and the slow-release agent, and in conjunction with the slow-release effect of the slow-release agent, the release rate of the antifungal agent is effectively adjusted, thereby improving the durability of the antifungal effect and achieving long-term stable release of the antifungal component.

[0010] The anti-mold system in the water-based coating composition of this invention completely eliminates the problems of traditional anti-mold agents, such as poor environmental performance, short anti-mold duration, easy discoloration of the paint film (reduction in whiteness), and poor thermal storage stability. It fundamentally solves the problems of short-lasting anti-mold effect and high environmental compliance risks inherent in water-based coatings with anti-mold properties. Simultaneously, the thickener of this invention helps improve the application area, anti-sagging properties, and leveling properties of the water-based coating composition. Combined with the nano-layered silicate anti-mold agent, it comprehensively improves the coating's fluidity, viscosity, anti-sagging properties, anti-splashing properties, and other application performance. This allows the water-based coating composition of this invention to overcome the bottleneck of traditional anti-mold systems, which cannot simultaneously achieve long-lasting anti-mold protection with comprehensive performance such as application performance, thermal storage stability, and paint film color stability.

[0011] Preferably, the molecular weight of the first cellulose is 1×10⁻⁶. 4 ~5×10 4 g / mol.

[0012] More preferably, the molecular weight of the first cellulose is 2 × 10⁻⁶. 4 ~4×10 4 g / mol.

[0013] Preferably, the molecular weight of the second cellulose is 0.8 × 10⁻⁶. 5 ~5×10 5 g / mol.

[0014] More preferably, the molecular weight of the second cellulose is 1×10⁻⁶. 5 ~3×10 5 g / mol.

[0015] More preferably, the molecular weight of the second cellulose is 1×10⁻⁶. 5 ~2×10 5 g / mol.

[0016] Preferably, the mass ratio of the first cellulose to the second cellulose is 1:(0.5~3.5).

[0017] More preferably, the mass ratio of the first cellulose to the second cellulose is 1:(0.5~2). For example, the mass ratio is 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:1, 1:1.5, 1:1.7, 1:1.8 or 1:2.

[0018] More preferably, the mass ratio of the first cellulose to the second cellulose is 1:(0.5~1.8).

[0019] More preferably, the mass ratio of the first cellulose to the second cellulose is 1:(0.5~1).

[0020] Preferably, the sustained-release adjuvant includes octadecanoic acid and octadecylamine.

[0021] Further optimization of octadecanoic acid and octadecylamine: the hydrophobic long-chain structure of octadecanoic acid can effectively regulate the release rate of the antifungal agent and delay the release of the antifungal component. At the same time, octadecylamine helps the antifungal agent to be evenly distributed and better exert its slow-release effect, which can further improve the durability of the antifungal effect.

[0022] More preferably, the mass ratio of the octadecanoic acid to the octadecylamine is 1:(0.5~2).

[0023] More preferably, the mass ratio of the octadecanoic acid to the octadecylamine is 1:(0.5~1.8). For example, this mass ratio can be 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:1, 1:1.5, 1:1.7 or 1:1.8.

[0024] More preferably, the mass ratio of the octadecanoic acid to the octadecylamine is 1:(0.5~0.8).

[0025] Preferably, the mass ratio of the thickener to the sustained-release agent is 1:(1~4).

[0026] More preferably, the mass ratio of the thickener to the sustained-release agent is 1:(2~4).

[0027] More preferably, the mass ratio of the thickener to the sustained-release agent is 1:(3~4).

[0028] More preferably, the mass ratio of the thickener to the sustained-release agent is 1:(3.5~4).

[0029] Preferably, the nano-layered silicate antifungal agent is prepared by intercalating the antifungal material into the interlayer of montmorillonite using montmorillonite as a carrier. Specifically, the nano-layered silicate antifungal agent has an irregular plate-like structure, with an average particle size distribution in the submicron to micron range (0.1~5μm), and a high specific surface area (typical value >50m²). 2 / g). This structure endows the material with excellent colloidal dispersibility and interfacial adsorption capacity. Its interlayer slow-release mechanism can disrupt the integrity of mold cell walls and inhibit the activity of metabolic enzymes, achieving highly efficient and broad-spectrum inhibition of eight types of molds, including Aspergillus niger and Aspergillus flavus.

[0030] More preferably, the anti-mildew material includes at least one of dodecyl dimethyl benzyl ammonium chloride, tetradecyl dimethyl benzyl ammonium chloride, and hexadecyl dimethyl benzyl ammonium chloride.

[0031] More preferably, the raw materials for preparing the nano-layered silicate antifungal agent include montmorillonite and an antifungal material; the mass ratio of montmorillonite to the antifungal material is 1:(0.25~0.3). For example, the mass ratio can be 1:0.25, 1:0.27, 1:0.28 or 1:0.3.

[0032] More preferably, the preparation method of the nano-layered silicate antifungal agent includes the following steps: Montmorillonite was dispersed in water, and antifungal material was added to react with it. After the reaction, the solid and liquid were separated, the precipitate was collected, and the nano-layered silicate antifungal agent was obtained after purification.

[0033] More preferably, the reaction temperature is 100~120°C.

[0034] More preferably, the reaction time is 7 to 9 hours.

[0035] More preferably, the step of dispersing montmorillonite in water includes: adding montmorillonite to water, adjusting the pH to 4-5, and dispersing at a speed of 1000-2000 rpm for 30-40 minutes.

[0036] Preferably, the water-based coating composition comprises the following components in parts by weight: The emulsion consists of 8-22 parts, thickener 0.2-0.6 parts, slow-release agent 0.5-1.8 parts, nano-layered silicate antifungal agent 0.5-2 parts, filler 22-65 parts, additives 1.5-17.5 parts, and water 10-50 parts.

[0037] More preferably, the water-based coating composition comprises, by weight parts, the following components: The emulsion contains 8-22 parts, thickener 0.2-0.6 parts, slow-release agent 0.5-1.5 parts, nano-layered silicate antifungal agent 0.8-1.5 parts, filler 22-65 parts, additives 1.5-17.5 parts, and water 10-50 parts.

[0038] More preferably, the water-based coating composition comprises, by weight parts, the following components: The ingredients are: 10-20 parts emulsion, 0.3-0.6 parts thickener, 1-1.5 parts slow-release agent, 0.8-1.5 parts nano-layered silicate antifungal agent, 33-65 parts filler, 1.8-6.2 parts additives, and 20-40 parts water.

[0039] More preferably, the water-based coating composition comprises, by weight parts, the following components: The emulsion consists of 12-18 parts, thickener 0.4-0.6 parts, slow-release agent 1-1.5 parts, nano-layered silicate antifungal agent 0.8-1.2 parts, filler 39-57 parts, additives 2.2-5.2 parts, and water 25-35 parts.

[0040] Preferably, the filler comprises titanium dioxide, kaolin, and calcite.

[0041] Preferably, the additives include multifunctional amine additives, dispersants, defoamers, bactericides, preservatives, antifreeze agents, and film-forming aids.

[0042] More preferably, the auxiliary agent comprises the following components by mass parts: Multifunctional amine additive 0.1~0.5 parts, dispersant 0.05~1 parts, defoamer 0.1~3 parts, preservative 0.01~1 parts, bactericide 0.2~2 parts, antifreeze 0.05~5 parts, film-forming aid 1~5 parts.

[0043] More preferably, the adjuvant comprises the following components by mass parts: Multifunctional amine additive 0.1~0.4 parts, dispersant 0.2~0.8 parts, defoamer 0.1~0.6 parts, preservative 0.05~0.2 parts, bactericide 0.2~0.7 parts, antifreeze 0.2~1 parts, film-forming aid 1~2.5 parts.

[0044] More preferably, the auxiliary agent comprises the following components by mass parts: Multifunctional amine additive 0.1~0.3 parts, dispersant 0.3~0.7 parts, defoamer 0.1~0.4 parts, preservative 0.05~0.2 parts, bactericide 0.2~0.6 parts, antifreeze 0.5~1 parts, film-forming aid 1~2 parts.

[0045] Preferably, the water-based coating composition comprises the following components in parts by weight: The emulsion contains 8-22 parts, thickener 0.2-0.6 parts, slow-release agent 0.5-1.8 parts, nano-layered silicate antifungal agent 0.5-2 parts, titanium dioxide 5-15 parts, kaolin 7-15 parts, calcite 10-35 parts, multifunctional amine agent 0.1-0.5 parts, dispersant 0.05-1 part, defoamer 0.1-3 parts, bactericide 0.2-2 parts, preservative 0.01-1 part, antifreeze 0.05-5 parts, film-forming aid 1-5 parts, and water 10-50 parts.

[0046] More preferably, the water-based coating composition comprises, by weight parts, the following components: The ingredients are: 8-22 parts emulsion, 0.2-0.6 parts thickener, 0.8-1.5 parts slow-release agent, 0.8-1.5 parts nano-layered silicate antifungal agent, 5-15 parts titanium dioxide, 7-15 parts kaolin, 10-35 parts calcite, 0.1-0.5 parts multifunctional amine agent, 0.05-1 part dispersant, 0.1-3 parts defoamer, 0.2-2 parts bactericide, 0.01-1 part preservative, 0.05-5 parts antifreeze, 1-5 parts film-forming aid, and 10-50 parts water.

[0047] More preferably, the water-based coating composition comprises, by weight parts, the following components: The ingredients are: 10-20 parts emulsion, 0.3-0.6 parts thickener, 1-1.5 parts slow-release agent, 0.8-1.5 parts nano-layered silicate antifungal agent, 5-10 parts titanium dioxide, 8-15 parts kaolin, 20-40 parts calcite, 0.1-0.4 parts multifunctional amine agent, 0.2-0.8 parts dispersant, 0.1-0.6 parts defoamer, 0.2-0.7 parts bactericide, 0.05-0.2 parts preservative, 0.2-1 part antifreeze, 1-2.5 parts film-forming aid, and 20-40 parts water.

[0048] More preferably, the water-based coating composition comprises, by weight parts, the following components: The ingredients are: 12-18 parts emulsion, 0.4-0.6 parts thickener, 1-1.5 parts slow-release agent, 0.8-1.2 parts nano-layered silicate antifungal agent, 6-10 parts titanium dioxide, 8-12 parts kaolin, 25-35 parts calcite, 0.1-0.3 parts multifunctional amine agent, 0.3-0.7 parts dispersant, 0.1-0.4 parts defoamer, 0.2-0.6 parts bactericide, 0.05-0.2 parts preservative, 0.5-1 part antifreeze, 1-2 parts film-forming aid, and 25-35 parts water.

[0049] Preferably, the multifunctional amine auxiliary includes at least one of organic alcohol amines, ammonia, and sodium hydroxide.

[0050] Preferably, the dispersant comprises at least one selected from polycarboxylate, sulfate, sulfonate, and sodium polyacrylate.

[0051] Preferably, the defoamer includes at least one of silicone defoamers, mineral oil defoamers, and acrylate defoamers.

[0052] Preferably, the bactericide comprises at least one of DBNPA, CMIT, MIT, and BIT. Specifically, DBNPA is 2,2-dibromo-3-acrylonitrile propionamide, CMIT is 5-chloro-2-methyl-4-isothiazolin-3-one, MIT is 2-methyl-4-isothiazolin-3-one, and BIT is 1,2-benzisothiazolin-3-one.

[0053] Preferably, the antifreeze includes at least one of propylene glycol, ethylene glycol, glycerol, and phosphate ester.

[0054] Preferably, the film-forming aid comprises at least one of alcohol ester solvents, 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, diisobutyl adipate, diisobutyl glutarate, and diisobutyl succinate.

[0055] More preferably, the film-forming aid includes at least one of alcohol ester solvents, Texanol, Coasol, and Coasol 290.

[0056] Preferably, the kaolin is calcined kaolin.

[0057] Preferably, the emulsion includes at least one of styrene-acrylic emulsion, pure acrylic emulsion, vinyl acetate-acrylic emulsion, VAE emulsion, tert-vinyl acetate emulsion, and silicone-acrylic emulsion.

[0058] A second aspect of the present invention provides a method for preparing the water-based coating composition described in the first aspect of the present invention, comprising the following steps: The emulsion, thickener, slow-release agent, nano-layered silicate antifungal agent, filler, additives and water are mixed to obtain the water-based coating composition.

[0059] Preferably, the preparation method includes the following steps: After the thickener, multifunctional amine additive, slow-release additive, dispersant and defoamer are first mixed, titanium dioxide, calcined kaolin and calcite are added for the second mixing, and finally water, bactericide, emulsion, antifreeze and film-forming aid are added for the third mixing to obtain the water-based coating composition.

[0060] A third aspect of the present invention provides an anti-mildew coating, which is prepared from the water-based coating composition described in the first aspect of the present invention.

[0061] A fourth aspect of the present invention provides an application of the water-based coating composition of the first aspect of the present invention or the anti-mildew coating of the third aspect of the present invention in the field of construction.

[0062] Compared with the prior art, the beneficial effects of the present invention are: The water-based coating composition of this invention uses a nano-layered silicate antifungal agent as the main antifungal component, and combines it with specific thickeners and slow-release additives to construct an antifungal system with a slow-release effect, which has long-lasting antifungal performance. Specifically, this invention utilizes a network structure formed by cellulose of different molecular weights and slow-release additives, and effectively adjusts the release rate of the antifungal agent in conjunction with the slow-release effect of the slow-release additives to achieve a long-lasting antifungal effect. In the antifungal challenge test, it showed excellent antifungal performance, with no mold growth for 56 days, significantly better than conventional antifungal systems. Furthermore, the combined effect of the thickener, slow-release additives, nano-layered silicate antifungal agent, and other components in the water-based coating composition ensures the thermal storage stability and color stability of the water-based coating composition. It performs excellently in the whiteness test of the paint film after thermal storage, with a whiteness reduction rate of only 1%. It also comprehensively improves the fluidity, viscosity, anti-sagging, and anti-splatter properties of the water-based coating composition, enhancing its workability. Therefore, this water-based coating composition does not require traditional chemical antifungal agents, meets environmental protection requirements, and achieves environmentally friendly, efficient, and long-lasting antifungal and antibacterial effects. At the same time, it improves the user experience and application performance of the coating, making it suitable for preparing antifungal coatings for use in the construction industry. Detailed Implementation

[0063] The present invention will be further described in detail below through specific embodiments. Unless otherwise specified, the raw materials, reagents, or apparatus used in the embodiments and comparative examples are all available from conventional commercial sources or can be obtained by existing technical methods. Unless otherwise specified, the test or experimental methods are conventional methods in the art.

[0064] The raw materials used in the following embodiments and comparative examples of the present invention are shown in Table 1 below.

[0065] Table 1. Raw material list for embodiments and comparative examples of the present invention.

[0066] The preparation method of the nano-layered silicate antifungal agent used in the examples and comparative examples is as follows: 100g of montmorillonite was added to a dispersion tank containing 3L of water. The pH of the slurry was adjusted to 4 with H2SO4. The slurry was dispersed at 1000r / min for 30min using a high-speed disperser to ensure thorough dispersion. Subsequently, the dispersion tank was transferred to a constant temperature water-oil bath at 110℃. 27g of dodecyl dimethyl benzyl ammonium chloride was added, and the mixture was stirred and kept at 200r / min for 8h. The mixture was then centrifuged at 1000r / min for 2min, and the precipitate was collected. The precipitate was washed with pure water and centrifuged again, repeating this process three times. Finally, the collected precipitate was dried in an 80℃ forced-air constant temperature oven. After drying, it was ground into powder using an ultrafine pulverizer to obtain a nano-layered silicate antifungal agent.

[0067] The following detailed description is provided with reference to specific embodiments: Example 1 A water-based coating composition, the formulation of which is shown in Table 2, is prepared as follows: Add water (the first added water) to a container. While stirring at 400 rpm, add thickener, multifunctional amine additive, slow-release additive, dispersant, and defoamer A in sequence and stir for 3 minutes. Then increase the speed to 800 rpm, and add the powder at a speed that prevents the powder from piling up. Add rutile titanium dioxide, calcined kaolin, and ultrafine calcite powder in sequence. After all the powders are mixed evenly and there is no obvious piling up, increase the speed to 1500 rpm for high-speed dispersion for 15 minutes. After high-speed dispersion is completed, adjust the stirring speed to 800 rpm and add the remaining water (the second added water), bactericide, emulsion, antifreeze, film-forming aid, and defoamer B in sequence and stir for 15 minutes to obtain the water-based coating composition.

[0068] Examples 2-7 A water-based coating composition, the formulation of which is shown in Table 2, and the preparation method is the same as in Example 1.

[0069] Table 2 Formulation table (parts by weight) of the water-based coating compositions in Examples 1-7

[0070] Examples 8-12 A water-based coating composition, the formulation of which is shown in Table 3, is prepared using the same method as in Example 1.

[0071] Table 3 Formulation table (parts by weight) of the water-based coating compositions of Examples 1 and 8-12

[0072] Comparative Examples 1-7 A water-based coating composition, the formulation of which is shown in Table 4, and the preparation method is the same as in Example 1.

[0073] Table 4 Formulation table (parts by weight) of water-based coating compositions in Comparative Examples 1-7

[0074] Result detection The performance of the water-based coating compositions in the above embodiments and comparative examples was tested.

[0075] Anti-mold challenge: Refer to GB / T 1741-2020 for 28-day and 56-day anti-mold challenge tests.

[0076] Whiteness reduction rate: The whiteness test of the paint film was performed by scraping a film onto a coated white card using a modern ISO-150μm wet film preparation device. The film was then allowed to dry naturally at room temperature. Whiteness 1 was recorded using an X-Rite Color-Eye 7000A. After storing the film at 55℃ for 8 weeks, the film was scraped again in the same manner and dried at room temperature. Whiteness 2 was then recorded. The whiteness reduction rate of the paint film was calculated, i.e., whiteness reduction rate = (whiteness 1 - whiteness 2) / whiteness 1.

[0077] Thermal storage stability: After storage in a 55℃ oven, observe the coating viscosity (KU viscosity) and state (whether it separates into water).

[0078] Workability: The roller coating process was simulated under normal application conditions, and the results were evaluated by operators based on the actual feel of the coating, the defoaming of the paint film, and the leveling appearance. The dry film thickness was 60 μm, with two roller coats applied, followed by a second roller coat after drying, each with a dry film thickness of 30 μm.

[0079] The test results are shown in Tables 5 to 13 below.

[0080] Table 5 Performance test results of waterborne coating compositions in Examples 1-3

[0081] As shown in Table 5, the 28-day and 56-day anti-mold challenge tests in Example 1 showed no mold growth, indicating good anti-mold durability. Furthermore, the paint film was not prone to discoloration, and the whiteness decreased by only 1% after 8 weeks of storage at 55℃. It also exhibited excellent thermal storage stability and workability, demonstrating superior overall performance. In Examples 2 and 3, the performance of the water-based coating composition changed due to variations in the amount of nano-layered silicate anti-mold agent used. Specifically, in Example 2, the reduced amount of nano-layered silicate anti-mold agent resulted in trace growth after the 28-day anti-mold challenge test, significantly reducing the durability of the anti-mold effect compared to Example 1. Conversely, the increased amount of nano-layered silicate anti-mold agent in Example 2 negatively impacted both thermal storage stability and workability.

[0082] Table 6 Performance test results of the waterborne coating compositions in Examples 1 and 4-5

[0083] As shown in Table 6, compared with Example 1, the ratio and amount of octadecanoic acid and octadecylamine changed in Examples 4 and 5. Simultaneously, the ratio between the thickener and the slow-release agent also changed, affecting the durability of the anti-mold effect and the thermal storage stability. The durability of the anti-mold effect or the thermal storage stability decreased in Examples 4 and 5.

[0084] Table 7 Performance test results of the waterborne coating compositions in Examples 1 and 6-7

[0085] As can be seen from Table 7, compared with Example 1, the ratio of low molecular weight cellulose to high molecular weight cellulose changed in Examples 6 and 7, which affected the durability of the anti-mold effect, workability, and thermal storage stability. Examples 6 and 7 showed reduced durability of the anti-mold effect and worse workability; Example 7 also exhibited reduced thermal storage stability.

[0086] Table 8 Performance test results of the waterborne coating compositions in Examples 1 and 8-9

[0087] As can be seen from Table 8, compared with Example 1, the ratio between thickener and slow-release agent in Examples 8 and 9 has changed. That is, the total amount of low molecular weight cellulose and high molecular weight cellulose, the total amount of octadecanoic acid and octadecylamine, and the ratio between them have changed. Combined with the results of Examples 4 and 5, it can be seen that this change will affect the durability of anti-mildew effect, thermal storage stability and workability.

[0088] Table 9 Performance test results of the waterborne coating compositions in Examples 1 and 10-11

[0089] As can be seen from Table 9, compared with Example 1, the ratio of octadecanoic acid and octadecylamine in Examples 10 and 11 changed. When the ratio between thickener and slow-release agent was close to that in Example 1, it had a certain impact on the durability of the anti-mold effect. For example, trace growth appeared after the 56-day anti-mold challenge, but it did not affect the thermal storage stability, workability and whiteness reduction rate.

[0090] Table 10 Performance test results of the waterborne coating compositions in Examples 1 and 12

[0091] As can be seen from Table 10, compared with Example 1, the type of slow-release adjuvant was changed in Example 12, and the durability of the anti-mold effect changed. In Example 12, trace growth appeared after 56 days of anti-mold challenge, and the durability of the anti-mold effect was poor.

[0092] Table 11 Performance test results of the waterborne coating compositions of Examples 1 and Comparative Examples 1-3

[0093] As shown in Table 11, compared with Example 1, Comparative Example 1 did not add a slow-release additive, replaced the nano-layered silicate antifungal agent with a traditional antifungal agent, and did not add high molecular weight cellulose. That is, it used a conventional antifungal agent instead of the antifungal system of this invention (thickener + slow-release additive + nano-layered silicate antifungal agent). This resulted in reduced antifungal durability, failing the 56-day antifungal challenge, and a 6-fold increase in whiteness reduction rate, making the paint film prone to discoloration. Comparative Examples 2 and 3 did not add a slow-release additive and only added either high molecular weight cellulose or low molecular weight cellulose. This resulted in decreased antifungal durability, thermal storage stability, and workability.

[0094] Table 12 Performance test results of the waterborne coating compositions of Examples 1 and Comparative Examples 4-5

[0095] As can be seen from Table 12, compared with Example 1, Comparative Examples 4 and 5 only used low molecular weight cellulose or high molecular weight cellulose, lacking the synergistic effect of the two different molecular weights of cellulose, resulting in a decrease in the durability of the anti-mildew effect, thermal storage stability and workability.

[0096] Table 13 Performance test results of the waterborne coating compositions of Examples 1 and Comparative Examples 6-7

[0097] As can be seen from Table 13, compared with Example 1, Comparative Examples 6 and 7 omitted the slow-release additive or replaced the thickener (two types of cellulose) with an alkali-swellable thickener. The anti-mold effect of Comparative Example 6 was significantly less durable, and trace growth appeared after 56 days of anti-mold challenge. In contrast, the anti-mold effect durability, thermal storage stability and workability of Comparative Example 7 were all reduced.

[0098] In summary, this invention discloses a water-based coating composition that uses a nano-layered silicate antifungal agent as the main antifungal component, and combines it with specific thickeners and slow-release additives to construct an antifungal system with a slow-release effect. This system has long-lasting antifungal performance and is more environmentally friendly than traditional chemical antifungal agents. Specifically, in the water-based coating composition of this invention, the network structure formed by cellulose of different molecular weights and slow-release additives, combined with the slow-release effect of the additives, effectively adjusts the release rate of the antifungal agent, achieving a long-lasting antifungal effect. In antifungal challenge tests, it exhibits excellent antifungal performance, with no mold growth for 56 days, significantly superior to conventional antifungal systems. Simultaneously, the combined effects of thickeners, slow-release agents, nano-layered silicate antifungal agents, and other components in the water-based coating composition ensure the thermal storage stability and color stability of the paint film (low whiteness reduction rate, less prone to discoloration). It exhibits excellent performance in post-thermal storage whiteness tests, with high contrast ratio and whiteness. Furthermore, it comprehensively improves the fluidity, viscosity, anti-sagging, and anti-splatter properties of the water-based coating composition, enhancing its application performance. Therefore, this water-based coating composition is suitable for preparing antifungal coatings for use in the construction industry.

[0099] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A water-based coating composition, characterized in that, The water-based coating composition includes an emulsion, a thickener, a slow-release agent, a nano-layered silicate antifungal agent, a filler, an additive, and water; The thickener comprises a first cellulose and a second cellulose; the first cellulose and the second cellulose have different molecular weights; the sustained-release agent comprises at least one of hexadecyl alcohol, glyceryl stearate, octadecanoic acid, octadecylamine, and polyethylene glycol-polylactic acid block copolymer.

2. The water-based coating composition according to claim 1, characterized in that, The molecular weight of the first cellulose is 1×10⁻⁶. 4 ~5×10 4 g / mol; And / or, the molecular weight of the second cellulose is 0.8 × 10⁻⁶. 5 ~5×10 5 g / mol; And / or, the mass ratio of the first cellulose to the second cellulose is 1:(0.5~3.5).

3. The water-based coating composition according to claim 1, characterized in that, The sustained-release adjuvants include octadecanoic acid and octadecylamine; And / or, the mass ratio of the octadecanoic acid to the octadecylamine is 1:(0.5~2).

4. The water-based coating composition according to claim 1, characterized in that, The nano-layered silicate antifungal agent is prepared by intercalating antifungal materials into the montmorillonite layers using montmorillonite as a carrier.

5. The water-based coating composition according to any one of claims 1 to 4, characterized in that, The water-based coating composition comprises the following components in parts by weight: The emulsion contains 8-22 parts, thickener 0.2-0.6 parts, slow-release agent 0.8-1.8 parts, nano-layered silicate antifungal agent 0.5-2 parts, filler 22-65 parts, additives 1.5-17.5 parts, and water 10-50 parts.

6. The water-based coating composition according to claim 5, characterized in that, The filler includes titanium dioxide, kaolin, and calcite; And / or, the additives include multifunctional amine additives, dispersants, defoamers, bactericides, preservatives, antifreeze agents, and film-forming aids.

7. The water-based coating composition according to claim 6, characterized in that, The water-based coating composition comprises the following components in parts by weight: The emulsion contains 8-22 parts, thickener 0.2-0.6 parts, slow-release agent 0.8-1.8 parts, nano-layered silicate antifungal agent 0.5-2 parts, titanium dioxide 5-15 parts, kaolin 7-15 parts, calcite 10-35 parts, multifunctional amine agent 0.1-0.5 parts, dispersant 0.05-1 part, defoamer 0.1-3 parts, bactericide 0.2-2 parts, preservative 0.01-1 part, antifreeze 0.05-5 parts, film-forming aid 1-5 parts, and water 10-50 parts.

8. A method for preparing the water-based coating composition according to any one of claims 1 to 7, characterized in that, Includes the following steps: The emulsion, thickener, slow-release agent, nano-layered silicate antifungal agent, filler, additives and water are mixed to obtain the water-based coating composition.

9. A mildew-resistant coating, characterized in that, The anti-mildew coating is prepared from the water-based coating composition according to any one of claims 1 to 7.

10. The application of a water-based coating composition according to any one of claims 1 to 7 or an anti-mildew coating according to claim 9 in the field of construction.

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