Long-acting mildew-proof energy-saving coating and preparation method thereof

Abstract

The invention belongs to the technical field of coatings, and particularly relates to a long-acting mildew-proof energy-saving coating and a preparation method thereof. The coating comprises 80 to 100 parts of a polymer base material, 100 to 120 parts of modified hollow glass beads, 25 to 35 parts of a precursor solution, 4 to 6 parts of a coalescing agent, 0.4 to 0.6 part of a thickening agent, 0.3 to 0.5 part of a defoaming agent and 10 to 15 parts of deionized water. 8DSS polypeptide is covalently grafted on the surface of the modified hollow glass bead, and the precursor solution comprises a silicon source, a calcium source and an antibacterial metal ion source. In the coating film forming process, the 8DSS polypeptide guides the precursor solution to be mineralized in situ on the surfaces and gaps of the microbeads, and a silicon-based mineral network rich in antibacterial metal ions is formed. The network and the hollow glass beads form a closed porous multi-scale composite heat insulation structure in the coating, so that the heat conductivity coefficient of the coating is remarkably reduced, and meanwhile, lasting and non-dissolution antibacterial and mildew-proof capabilities are provided.

Description

Technical Field

[0001] This invention relates to the field of building decoration coatings technology, specifically to a long-lasting anti-mildew and energy-saving coating and its preparation method. Background Technology

[0002] With the increasing demand for green buildings and healthy living environments, higher requirements are being placed on the comprehensive functions of architectural coatings, especially energy-saving insulation and anti-mildew and antibacterial properties. Currently, most functional coatings on the market employ physical blending technology, which simply adds heat-insulating fillers (such as hollow glass microspheres) and chemical anti-mildew agents (such as isothiazolinones) to the coating base. This approach has inherent drawbacks: firstly, heat insulation relies on the physical barrier of heat conduction provided by fillers such as hollow glass microspheres; secondly, anti-mildew relies on the chemical toxicity of organic bactericides (such as isothiazolinones). These two components are independent of each other in the coating, with clearly separated functional interfaces. In practice, the performance of the two often restricts each other: on the one hand, the huge specific surface area of ​​porous insulating fillers can adsorb and fix some antifungal agent molecules, hindering their effective migration to the coating surface, resulting in the antifungal efficacy being "shielded"; on the other hand, some antifungal agents affect the stability of polymer emulsions or react with additives, thereby damaging the overall mechanical properties and durability of the coating; secondly, although this method is simple and has high sterilization efficiency, chemical antifungal agents will become ineffective over time due to migration, volatilization or decomposition, failing to meet the long-term service requirements of building exterior walls, and posing environmental and health hazards; in addition, simple physical mixing is difficult to build an integrated functional structure inside the coating. Although some studies have attempted to load antibacterial components onto the filler surface through pretreatment, it is mostly based on physical adsorption, with weak bonding force, and is prone to failure and detachment under complex environmental stress, with limited thermal insulation efficiency and antifungal durability.

[0003] Therefore, developing a coating that is non-leaching and has excellent anti-mildew and thermal insulation properties has become an urgent need in the current architectural coatings industry.

[0004] Therefore, this invention is proposed to solve the above-mentioned technical problems. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a coating that can provide long-lasting mildew prevention and energy saving, as well as a method for preparing the coating.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A long-lasting anti-mildew and energy-saving coating, comprising the following components by weight: 80-100 parts polymer base, 100-120 parts modified hollow glass microspheres, 25-35 parts precursor solution, 4-6 parts film-forming aid, 0.4-0.6 parts thickener, 0.3-0.5 parts defoamer, and 10-15 parts deionized water. The precursor solution contains a silicon source, a calcium source, and an antibacterial metal ion source. The modified hollow glass microspheres are loaded with 8DSS, which includes an aspartic-serine-serine polypeptide sequence with eight repeating sequences.

[0008] In the technical solution of the present invention, the film-forming aid is one or a mixture of several of ethylene glycol phenyl ether, dodecyl alcohol ester, and ethylene glycol monobutyl ether, preferably dodecyl alcohol ester.

[0009] In the technical solution of the present invention, the thickener is one or a mixture of hydroxyethyl cellulose, hydroxypropyl methyl cellulose, and hydroxypropyl cellulose, and preferably the thickener is hydroxypropyl cellulose.

[0010] In the technical solution of this invention, the defoamer is an organosilicon defoamer.

[0011] In the technical solution of this invention, the method for preparing the modified hollow glass microspheres is as follows:

[0012] S1. The hollow glass microspheres are placed in a dilute acid solution and ultrasonically treated. After being washed with deionized water until neutral, they are vacuum dried to obtain pretreated hollow glass microspheres.

[0013] S2. After dissolving APTES in anhydrous ethanol to obtain an APTES solution, add the pretreated hollow glass microspheres described in step S1, and stir the reaction at a constant temperature of 30°C to obtain aminated hollow glass microspheres.

[0014] S3. Dissolve the 8DSS peptide in PBS buffer at pH 5.5-6, add EDC and NHS sequentially, and activate at room temperature for 30 min to obtain the activated peptide solution.

[0015] S4. Add the aminated hollow glass microspheres obtained in step S2 to the activated polypeptide solution obtained in step S3, and perform a constant temperature oscillation reaction to obtain hollow glass microspheres grafted with polypeptides.

[0016] S5. The hollow glass microspheres grafted with the polypeptide described in step S4 are washed sequentially with PBS buffer and deionized water, and then dried to obtain the modified hollow glass microspheres.

[0017] In this invention, 8DSS peptide-modified hollow glass microspheres serve as a dual-functional core dispersed in the coating. During the coating film formation process, the active side chains of the peptides (carboxyl groups of aspartic acid and hydroxyl groups of serine) specifically guide calcium ions, silicate ions, zinc ions, etc., in the precursor solution to undergo mineralization reactions on the surface of the microspheres and in the gaps between the microspheres. The resulting silicon-based mineral network has abundant nanopores, containing a large amount of sealed, non-convective static air, forming countless tiny "air insulation units" that effectively block heat conduction. Simultaneously, this silicon-based mineral network and the hollow glass microspheres, through structural interlocking and functional synergy, together constitute a multi-scale composite insulation system: hollow glass... The glass microspheres provide high thermal resistance through their closed, still air core, while the calcium silicate network greatly extends the solid heat conduction path and enhances heat radiation scattering by filling the gaps between the microspheres, encapsulating them, and forming tortuous nanopores. The two work together to eliminate the "thermal bridge" formed by the resin matrix, blocking heat transfer in all directions through conduction, radiation, and convection, effectively reducing the overall effective thermal conductivity. At the same time, antibacterial metal ions are immobilized in situ in the mineral lattice through coordination bonds, providing long-lasting and non-leaking contact antibacterial and anti-mildew capabilities, thus achieving long-lasting energy saving and mildew prevention of the coating.

[0018] In the technical solution of the present invention, in step S1, the dilute acid is hydrochloric acid with a mass fraction of 1% to 3%, and the hollow glass microspheres and the dilute acid are mixed at a material-to-liquid ratio of 1:15 (g / mL).

[0019] In the technical solution of the present invention, in step S2, the volume ratio of APTES to anhydrous ethanol is 1:50, and the pretreated hollow glass microspheres and APTES solution are mixed at a material-to-liquid ratio of 1:30 (g / mL).

[0020] In the technical solution of the present invention, in step S3, the EDC, NHS and 8DSS peptides are mixed in a mass ratio of 0.8:0.7:1, and the concentration of 8DSS in the activated peptide solution is 2 mg / ml.

[0021] In the technical solution of the present invention, in step S4, the aminated hollow glass microspheres and the activated polypeptide solution are mixed at a ratio of 1:15 (g / mL).

[0022] In this invention, a 1%–3% hydrochloric acid solution can be used to clean the surface of hollow glass microspheres, removing inorganic impurities and some surface contaminants. Simultaneously, it lightly etches the surface, increasing surface roughness and hydroxyl (–OH) density, thereby enhancing the adhesion and reactivity of the subsequent silane coupling agent (APTES). APTES (3-aminopropyltriethoxysilane), as a silane coupling agent, reacts with the –OH groups on the microsphere surface after ethoxylation to form Si–O–Si covalent bonds, while simultaneously introducing terminal amino groups (–NH2), achieving amino functionalization of the microsphere surface and providing reaction sites for subsequent covalent grafting with peptides. Anhydrous ethanol is used as a solvent to promote the dissolution and uniform dispersion of APTES, control the polarity of the reaction system, and prevent premature hydrolysis of APTES caused by moisture. Self-polymerized 8DSS is an acidic polypeptide composed of eight tandemly repeated aspartic-serine-serine (Asp-Ser-Ser, DSS) sequences. This invention introduces 8DSS into an architectural coating system for the first time. In this system, the polypeptide acts as a mineralization guiding molecule. The carboxyl and hydroxyl groups in its side chains are key functional groups that can specifically guide the deposition of calcium, silicon, and antibacterial metal ions. This allows 8DSS to guide the co-deposition of silicate ions with calcium ions and antibacterial metal ions on and between microbeads, forming a silicon-based mineral network rich in calcium and zinc ions. To firmly and directionally fix it on the surface of the microbeads, the pH of the reaction system is strictly controlled between 5.5 and 6.0 using PBS buffer, ensuring that all carboxyl groups of the 8DSS polypeptide are in a deprotonated state. EDC acts as a coupling agent, and its core function is to react with the deprotonated carboxyl groups: the carboxyl anion (-COO⁻) nucleophilically attacks the carbodiimide carbon in the EDC molecule, forming an unstable O-acylisourea intermediate. To prevent the intermediate from rapid hydrolysis and degradation, NHS was added to the system. NHS then attacked the intermediate, converting it into a chemically stable and highly reactive N-hydroxysuccinimide ester (the active ester). In this specific system, the grafting reaction exhibited significant selectivity. This is because the high-density negatively charged region of the side-chain carboxyl groups in the 8DSS sequence forms an electrostatic shield for the EDC activation process, and its large steric hindrance makes it difficult for EDC / NHS to effectively approach and activate the side-chain carboxyl groups. Conversely, the carboxyl groups at the ends of the polypeptide chain have a loose charge environment and high steric accessibility, thus being preferentially and efficiently activated by EDC / NHS into stable active esters. Finally, this active ester undergoes a nucleophilic substitution reaction with the free amino groups (-NH2) present in the protonation equilibrium on the surface of the aminated hollow glass microspheres, forming strong covalent amide bonds, thereby directionally immobilizing the 8DSS polypeptide on the surface of the microspheres, achieving covalent grafting. Deionized water is used for washing to remove impurities, ultimately obtaining surface-grafted polypeptides and modified hollow glass microspheres with in-situ mineralization guidance capabilities.

[0023] In the technical solution of the present invention, the polymer emulsion is any one or a combination of at least two of styrene-acrylic emulsion, pure acrylic emulsion, or silicone-acrylic emulsion.

[0024] In the technical solution of the present invention, the precursor solution contains a silicon source, a calcium source and an antibacterial metal ion source, wherein the molar ratio of silicon, calcium and antibacterial metal ions is such that the molar ratio of silicon (Si), calcium (Ca) and zinc (Zn) is 1:1:0.1.

[0025] In this invention, the silicon source can be common silicate or silane compounds such as methyl orthosilicate or tetraethyl orthosilicate (TEOS); preferably tetraethyl orthosilicate. The calcium source can be water-soluble calcium salts such as calcium chloride, calcium nitrate, and calcium acetate. The antibacterial metal ion source is preferably one or more of zinc salt, silver salt, or copper salt.

[0026] Preferably, the hollow glass microspheres have a particle size of 0.12~0.15μm.

[0027] The present invention also provides a method for preparing a long-lasting anti-mildew and energy-saving coating, comprising the following steps: according to the weight ratio, first mix the polymer base, film-forming aid, thickener, defoamer, modified hollow glass microspheres and deionized water evenly, then pour the precursor solution while stirring evenly to obtain the long-lasting anti-mildew and energy-saving coating.

[0028] The beneficial effects of this invention are:

[0029] By grafting 8DSS peptides onto the surface of hollow glass microspheres and using them to guide the in-situ mineralization reaction of the precursor solution, a dual-functional coating structure with both high-efficiency heat insulation and long-lasting mildew prevention was successfully constructed, solving the problem that the heat insulation and mildew prevention properties of traditional physical blend coatings are mutually restrictive and difficult to coexist for a long time.

[0030] Antibacterial metal ions (such as Zn²⁺) are immobilized in situ within a silicon-based mineral network, forming a non-leaching antibacterial system. This effectively prevents the migration of antibacterial metal ions, significantly extends the anti-mildew effect, and reduces potential risks to the environment and human health.

[0031] Hollow glass microspheres and silicon-based mineral networks form a closed, porous, multi-scale composite thermal insulation structure inside the coating, which synergistically blocks heat conduction, heat radiation and heat convection, significantly reducing the effective thermal conductivity of the coating and achieving long-term energy saving. Attached Figure Description

[0032] Figure 1 The figures show the test results of the antibacterial effect of the long-lasting anti-mildew and energy-saving coatings in Examples 1-3 and Comparative Examples 1-3 of the present invention. Detailed Implementation

[0033] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Example 1

[0035] 1. The preparation of modified hollow glass microspheres shall be carried out in the following steps:

[0036] S1. Place the hollow glass microspheres in a 1% hydrochloric acid solution and mix them at a ratio of 1:15 (g / mL) between the hollow glass microspheres and hydrochloric acid. Sonicate the mixture at 200W for 30 minutes, then wash it with deionized water until neutral, and vacuum dry it at 60℃ for 2 hours to obtain the pretreated hollow glass microspheres.

[0037] S2. Dissolve APTES (3-aminopropyltriethoxysilane) in anhydrous ethanol, controlling the volume ratio of APTES to anhydrous ethanol to be 1:50. Then add the pretreated hollow glass microspheres obtained in step 1 and mix them at a material-liquid ratio of 1:30 (g / mL) of pretreated hollow glass microspheres to APTES-ethanol solution. Stir the mixture at 150 r / min at 30℃ for 4 h to obtain aminated hollow glass microspheres.

[0038] S3. Dissolve the 8DSS peptide in PBS buffer at pH 5.5 to achieve a peptide concentration of 2 mg / mL. Then, add EDC (1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride) and NHS (N-hydroxysuccinimide) in sequence at a mass ratio of EDC:NHS:8DSS peptide = 0.8:0.7:1. Activate at room temperature for 30 min to obtain an activated peptide solution.

[0039] S4. The aminated hollow glass microspheres from step S2 are added to the activated polypeptide solution from step S3 at a material-to-liquid ratio of 1:15 (g / mL), and the reaction is carried out at 25°C with constant temperature shaking at 100 r / min for 8 h to obtain hollow glass microspheres grafted with polypeptide.

[0040] S5. The hollow glass microspheres with grafted peptides obtained in step S4 are washed sequentially with PBS buffer and deionized water, and dried in vacuum at 50°C for 4 hours to obtain the modified hollow glass microspheres.

[0041] 2. The preparation of the precursor solution shall be carried out in the following steps:

[0042] (1) Weigh tetraethyl orthosilicate, calcium nitrate and zinc nitrate, and calculate and weigh the required mass according to the molar ratio of silicon (Si), calcium (Ca) and zinc (Zn) elements of 1:1:0.1.

[0043] (2) Mix tetraethyl orthosilicate and anhydrous ethanol at a volume ratio of 1:4 and stir until homogeneous to obtain solution A;

[0044] (3) Then, calcium nitrate and zinc nitrate are dissolved together in deionized water at a ratio of 1:1 (g / ml) and stirred until completely dissolved to obtain solution B.

[0045] (4) While stirring continuously, slowly add solution B to solution A, and continue stirring for 30 minutes to obtain a uniform and stable precursor solution.

[0046] 3. The preparation of the coating includes the following steps:

[0047] First, mix 80 parts of silicone-acrylic emulsion, 100 parts of modified hollow glass microspheres, 25 parts of precursor solution, 4 parts of dodecyl alcohol ester, 0.4 parts of hydroxypropyl fiber, 0.3 parts of dimethyl silicone oil, and 10 parts of deionized water evenly. Then, pour in the precursor solution while stirring evenly to obtain a long-lasting anti-mildew and energy-saving coating.

[0048] Example 2

[0049] 1. The preparation of modified hollow glass microspheres shall be carried out in the following steps:

[0050] S1. Place the hollow glass microspheres in a 1% hydrochloric acid solution and mix them at a ratio of 1:15 (g / mL) between the hollow glass microspheres and hydrochloric acid. Sonicate the mixture at 200W for 30 minutes, then wash it with deionized water until neutral, and vacuum dry it at 60℃ for 2 hours to obtain the pretreated hollow glass microspheres.

[0051] S2. Dissolve APTES (3-aminopropyltriethoxysilane) in anhydrous ethanol, controlling the volume ratio of APTES to anhydrous ethanol to be 1:50. Then add the pretreated hollow glass microspheres obtained in step 1 and mix them at a material-liquid ratio of 1:30 (g / mL) of pretreated hollow glass microspheres to APTES-ethanol solution. Stir the mixture at 150 r / min at 30℃ for 4 h to obtain aminated hollow glass microspheres.

[0052] S3. Dissolve the 8DSS peptide in PBS buffer at pH=6 to achieve a peptide concentration of 2 mg / mL. Then, add EDC (1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride) and NHS (N-hydroxysuccinimide) in sequence at a mass ratio of EDC:NHS:8DSS peptide = 0.8:0.7:1. Activate at room temperature for 30 min to obtain an activated peptide solution.

[0053] S4. The aminated hollow glass microspheres from step S2 are added to the activated polypeptide solution from step S3 at a material-to-liquid ratio of 1:15 (g / mL), and the reaction is carried out at 25°C with constant temperature shaking at 100 rpm for 8 hours to obtain hollow glass microspheres grafted with polypeptide.

[0054] S5. The hollow glass microspheres with grafted peptides obtained in step S4 are washed sequentially with PBS buffer and deionized water, and dried in vacuum at 50°C for 4 hours to obtain the modified hollow glass microspheres.

[0055] 2. The preparation of the precursor solution shall be carried out in the following steps:

[0056] (1) Weigh out methyl orthosilicate, calcium nitrate and zinc nitrate, and calculate and weigh the required mass according to the molar ratio of silicon (Si), calcium (Ca) and zinc (Zn) elements of 1:1:0.1.

[0057] (2) Mix tetraethyl orthosilicate and anhydrous ethanol at a volume ratio of 1:4 and stir until homogeneous to obtain solution A;

[0058] (3) Then, calcium chloride and silver nitrate are dissolved together in deionized water at a ratio of 1:1 (g / ml) and stirred until completely dissolved to obtain solution B;

[0059] (4) While stirring continuously, slowly add solution B to solution A, and continue stirring for 30 minutes to obtain a uniform and stable precursor solution.

[0060] 3. The preparation of the coating includes the following steps:

[0061] First, mix 100 parts of styrene-acrylic emulsion, 120 parts of modified hollow glass microspheres, 35 parts of precursor solution, 6 parts of ethylene glycol phenyl ether, 0.6 parts of hydroxyethyl cellulose, 0.5 parts of dimethyl silicone oil, and 15 parts of deionized water evenly. Then, pour in the precursor solution while stirring evenly to obtain a long-lasting anti-mildew and energy-saving coating.

[0062] Example 3

[0063] 1. The preparation of modified hollow glass microspheres shall be carried out in the following steps:

[0064] S1. Place the hollow glass microspheres in a 1% hydrochloric acid solution and mix them at a ratio of 1:15 (g / mL) between the hollow glass microspheres and hydrochloric acid. Sonicate the mixture at 200W for 30 minutes, then wash it with deionized water until neutral, and vacuum dry it at 60℃ for 2 hours to obtain the pretreated hollow glass microspheres.

[0065] S2. Dissolve APTES (3-aminopropyltriethoxysilane) in anhydrous ethanol, controlling the volume ratio of APTES to anhydrous ethanol to be 1:50. Then add the pretreated hollow glass microspheres obtained in step 1 and mix them at a material-liquid ratio of 1:30 (g / mL) of pretreated hollow glass microspheres to APTES-ethanol solution. Stir the mixture at 150 r / min at 30℃ for 4 h to obtain aminated hollow glass microspheres.

[0066] S3. Dissolve the 8DSS peptide in PBS buffer at pH=6 to achieve a peptide concentration of 2 mg / mL. Then, add EDC (1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride) and NHS (N-hydroxysuccinimide) in sequence at a mass ratio of EDC:NHS:8DSS peptide = 0.8:0.7:1. Activate at room temperature for 30 min to obtain an activated peptide solution.

[0067] S4. The aminated hollow glass microspheres from step S2 are added to the activated polypeptide solution from step S3 at a material-to-liquid ratio of 1:15 (g / mL), and the reaction is carried out at 25°C with constant temperature shaking at 100 rpm for 8 hours to obtain hollow glass microspheres grafted with polypeptide.

[0068] S5. The hollow glass microspheres with grafted peptides obtained in step S4 are washed sequentially with PBS buffer and deionized water, and dried in vacuum at 50°C for 4 hours to obtain the modified hollow glass microspheres.

[0069] 2. The preparation of the precursor solution shall be carried out in the following steps:

[0070] (1) Weigh out methyl orthosilicate, calcium nitrate and zinc nitrate, and calculate and weigh the required mass according to the molar ratio of silicon (Si), calcium (Ca) and zinc (Zn) elements of 1:1:0.1.

[0071] (2) Mix tetraethyl orthosilicate and anhydrous ethanol at a volume ratio of 1:4 and stir until homogeneous to obtain solution A;

[0072] (3) Then, calcium chloride and silver nitrate are dissolved together in deionized water at a ratio of 1:1 (g / ml) and stirred until completely dissolved to obtain solution B.

[0073] (4) While stirring continuously, slowly add solution B to solution A, and continue stirring for 30 minutes to obtain a uniform and stable precursor solution.

[0074] 3. The preparation of the coating includes the following steps:

[0075] First, mix 90 parts of pure acrylic emulsion, 110 parts of modified hollow glass microspheres, 30 parts of precursor solution, 5 parts of ethylene glycol monobutyl ether, 0.5 parts of hydroxypropyl methylcellulose, 0.4 parts of dimethyl silicone oil, and 12 parts of deionized water evenly. Then, pour in the precursor solution while stirring evenly to obtain a long-lasting anti-mildew and energy-saving coating.

[0076] Comparative Example 1

[0077] Compared with Example 1, the only difference is that the preparation of "1. Preparation of modified hollow glass microspheres" is not performed, and in "3. Preparation of coating", the "modified hollow glass microspheres" are replaced with an equal amount of hollow glass microspheres that have not been modified by 8DS peptide grafting. All other steps and conditions remain the same.

[0078] Comparative Example 2

[0079] Compared with Example 1, the only difference is that the preparation of "1. Modified hollow glass microspheres" is not performed, and in "3. Preparation of coating", the "modified hollow glass microspheres" are replaced with an equal amount of hollow glass microspheres. At the same time, 8DSS peptides are directly added to the coating, and the amount added is determined with reference to the "actual 8DSS loading of modified hollow glass microspheres" in Example 1. Other steps and conditions remain the same.

[0080] Comparative Example 3

[0081] Compared with Example 1, the only difference is that silver nitrate is not added in step "2. Preparation of precursor solution", and zinc oxide, a traditional inorganic antibacterial agent, is replaced in equal molar form in step "3. Preparation of coating".

[0082] Test case

[0083] 1. Performance tests were conducted on the long-lasting anti-mildew and energy-saving coatings prepared in Examples 1-3 and Comparative Examples 1-3. Thermal conductivity was tested according to GB / T10294-2008 "Determination of Steady-State Thermal Resistance and Related Properties of Thermal Insulation Materials". A laser thermal conductivity meter (TC3000E, Beijing) was used. The test temperature was 25℃±1℃, and the humidity was 50%±5%. The drying time was in accordance with standard GB / T1728-1979. The initial drying crack resistance, bond strength, water resistance, and acid and alkali resistance were in accordance with standard JG / T24-2018. The aging resistance was tested for 600 hours according to standard GB / T1865-2009. The results are shown in Table 1.

[0084] Table 1

[0085] sample Thermal conductivity (W / m·K) Drying time (min) Initial drying crack resistance Bond strength (MPa) Water resistance Acid and alkali resistance Aging resistance Example 1 0.038 51 No cracks 2.1 No abnormalities in 45 days No abnormalities in 32 days No abnormalities Example 2 0.035 52 No cracks 2.2 No abnormalities in 45 days No abnormalities in 32 days No abnormalities Example 3 0.034 54 No cracks 2.4 No abnormalities in 45 days No abnormalities in 32 days No abnormalities Comparative Example 1 0.076 60 No cracks 1.8 No abnormalities in 25 days No abnormalities in 20 days Shedding Comparative Example 2 0.062 62 No cracks 1.9 No abnormalities in 32 days No abnormalities for 23 days Partial detachment Comparative Example 3 0.052 53 No cracks 2.0 No abnormalities in 40 days No abnormalities in 25 days No abnormalities

[0086] As shown in Table 1, the long-lasting anti-mildew and energy-saving coatings prepared in Examples 1-3 of this invention have a low thermal conductivity (≤0.038W / m·K), short drying time, good initial drying crack resistance, high bonding strength, and good water resistance, acid and alkali resistance, as well as good aging resistance. This indicates that the coating has excellent comprehensive performance and good heat insulation effect. Its excellent heat insulation performance (low thermal conductivity) mainly comes from the closed porous multi-scale composite heat insulation structure formed by hollow glass microspheres and silicon-based mineral network inside the coating. This structure synergistically blocks heat conduction, heat radiation, and heat convection, significantly reducing the effective thermal conductivity of the coating and achieving long-lasting energy saving.

[0087] 2. Antibacterial tests were conducted on the long-lasting anti-mildew and energy-saving coatings prepared in Examples 1-3 and Comparative Examples 1-3.

[0088] The specific method is as follows: Referring to standard GB / T21866-2008, place the coated plate and blank plate in petri dishes respectively. Take 0.5 mL of the prepared bacterial suspension and add it dropwise to the surface of the coated plate, then cover it with a PE film to ensure uniform contact of the bacterial suspension with the surface to be tested. Place the plates in an incubator and incubate for 48 hours at a temperature of 37℃ and a relative humidity greater than 90%. Remove the petri dishes and repeatedly wash the PE film and sample surface with deionized water. Take 1 mL of serially diluted washing solution and drop it into another petri dish. Pour in solid culture medium and shake horizontally to mix. After it has completely cooled, invert the plates and incubate at 37℃ for 48 hours. Count the colonies on the plates and calculate the antibacterial rate of the coating according to the following formula:

[0089] R = (BC) / B × 100%

[0090] In the formula: R is the antibacterial rate (%), B is the number of colonies recovered from the blank plate after 48 hours (cfu / mL), and C is the number of colonies recovered from the coated plate after 48 hours (cfu / mL).

[0091] Test results are available Figure 1

[0092] like Figure 1 As shown, the antibacterial rates of *Escherichia coli* in Examples 1-3 were 97.8%, 97.7%, and 98.9%, respectively, compared to 83.1% in Comparative Example 1, 85.2% in Comparative Example 2, and 80.4% in Comparative Example 3. The antibacterial rates of *Staphylococcus aureus* in Examples 1-3 were 96.8%, 96.5%, and 97.4%, respectively, compared to 73.1% in Comparative Example 1, 78.8% in Comparative Example 2, and 82.4% in Comparative Example 3. Compared to Comparative Examples 1-3, Examples 1-3 showed significantly improved antibacterial performance. This is because the covalently grafted 8DSS peptide effectively guided the in-situ formation of the silicon-based mineral network and stably immobilized antibacterial metal ions (such as Zn²⁺) within the network structure, thus providing durable and highly efficient contact antibacterial capabilities.

[0093] 3. Anti-mold tests were conducted on the long-lasting anti-mold and energy-saving coatings prepared in Examples 1-3 and Comparative Examples 1-3.

[0094] The specific method is as follows: Referring to the HG / T3950-2007 culture medium method, the sample was coated onto a cement board or other carrier closely resembling actual application conditions. After a certain artificial aging process, the test sample coated with the sample was placed on MSA culture medium. According to the mold species specified in the method, mold spore suspensions of each mold were prepared separately and mixed at equal concentrations. A certain concentration of the mixed spore suspension was sprayed onto the culture medium and the test sample, and then incubated at 25℃ for 3 months. The area of ​​mold growth on the sample surface was observed visually and microscopically and rated. The test results are shown in Table 2.

[0095] Culture medium: MSA.

[0096] Inoculation: HG / T standard mold (1.0×106 spores / ml).

[0097] Preprocessing: None

[0098] The mold growth level of the samples is assessed as follows:

[0099] Grade 0 means no growth is observed under a microscope (50x magnification);

[0100] Grade 1 trace growth, which is visible to the naked eye, but the growth coverage area is less than 10%;

[0101] Level 2 growth covers an area of ​​more than 10%.

[0102] Table 2

[0103] sample Mold growth level after 3 months Example 1 0 Example 2 0 Example 3 0 Comparative Example 1 2 Comparative Example 2 1 Comparative Example 3 2

[0104] As shown in Table 2, after 3 months of anti-mold testing, the mold growth level of Examples 1-3 was 0 (no growth observed); while the growth levels of Comparative Examples 1, 2, and 3 were 2, 1, and 2, respectively. Compared with the Comparative Examples, the Examples have a significant advantage in anti-mold performance. This is attributed to the silicon-based mineral network containing antibacterial metal ions, constructed guided by 8DSS peptides, which forms a non-leaching, long-lasting anti-mold system that effectively inhibits the growth and adhesion of mold.

[0105] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A long-lasting anti-mildew and energy-saving coating, characterized in that, The coating comprises the following components by weight: 80-100 parts polymer base, 100-120 parts modified hollow glass microspheres, 25-35 parts precursor solution, 4-6 parts film-forming aid, 0.4-0.6 parts thickener, 0.3-0.5 parts defoamer, and 10-15 parts deionized water. The precursor solution contains a silicon source, a calcium source, and an antibacterial metal ion source. The modified hollow glass microspheres are loaded with 8DSS, which includes an aspartic-serine-serine polypeptide sequence with eight repeating sequences.

2. The coating according to claim 1, characterized in that, The modified hollow glass microspheres are prepared by: S1. The hollow glass microspheres are placed in a dilute acid solution and ultrasonically treated. After being washed with deionized water until neutral, they are vacuum dried to obtain pretreated hollow glass microspheres. S2. After dissolving APTES in anhydrous ethanol to obtain an APTES solution, add the pretreated hollow glass microspheres described in step S1, and stir the reaction at a constant temperature of 30°C to obtain aminated hollow glass microspheres. S3. Dissolve the 8DSS peptide in PBS buffer at pH 5.5-6, add EDC and NHS sequentially, and activate at room temperature for 30 min to obtain the activated peptide solution. S4. Add the aminated hollow glass microspheres obtained in step S2 to the activated polypeptide solution obtained in step S3, and perform a constant temperature oscillation reaction to obtain hollow glass microspheres grafted with polypeptides. S5. The hollow glass microspheres grafted with the polypeptide described in step S4 are washed sequentially with PBS buffer and deionized water, and then dried to obtain the modified hollow glass microspheres.

3. The coating according to claim 2, characterized in that, In step S1, the dilute acid is hydrochloric acid with a mass fraction of 1% to 3%, and the hollow glass microspheres are mixed with the dilute acid at a ratio of 1:15 (g / mL).

4. The coating according to claim 2, characterized in that, In step S2, the volume ratio of APTES to anhydrous ethanol is 1:50, and the pretreated hollow glass microspheres and APTES solution are mixed at a material-to-liquid ratio of 1:30 (g / mL).

5. The coating according to claim 2, characterized in that, In step S3, the EDC, NHS and 8DSS peptides are mixed in a mass ratio of 0.8:0.7:1, and the concentration of 8DSS in the activated peptide solution is 2 mg / ml.

6. The coating according to claim 2, characterized in that, In step S4, the aminated hollow glass microspheres and the activated polypeptide solution are mixed at a ratio of 1:15 (g / mL).

7. The coating according to claim 1, characterized in that, The polymer emulsion is any one or a combination of at least two of styrene-acrylic emulsion, pure acrylic emulsion, or silicone-acrylic emulsion.

8. The coating according to claim 1, characterized in that, The precursor solution contains a silicon source, a calcium source, and an antibacterial metal ion source, wherein the molar ratio of silicon, calcium, and antibacterial metal ions is 1:1:0.1, based on the molar ratio of silicon (Si), calcium (Ca), and zinc (Zn) elements.

9. The coating according to claim 1, characterized in that, The hollow glass microspheres have a particle size of 0.12~0.15μm.

10. A method for preparing the coating as described in any one of claims 1 to 9, characterized in that, The process includes the following steps: according to the weight ratio, first mix the polymer base, 4-6 parts of film-forming aid, thickener, defoamer, modified hollow glass microspheres, and deionized water evenly, then pour in the precursor solution while stirring evenly to obtain the long-lasting anti-mildew and energy-saving coating.

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