Indoor air purification material and preparation method thereof

Abstract

The application relates to the field of coating compositions, and discloses an indoor air purification material and a preparation method thereof, which comprises the following components in proportion by weight: acrylic emulsion: 40-60 parts by weight; ultra-low VOCs film forming aid: 0.5-2 parts by weight; modified zeolite adsorbent: 2-8 parts by weight; nano photocatalyst: 1-5 parts by weight; VOCs-free thickening agent: 0.1-0.5 parts by weight; defoaming agent: 0.1-0.3 parts by weight; wet dispersing agent: 0.2-0.8 parts by weight; and water: 20-45 parts by weight. The indoor air purification material of the application realizes the balance between VOCs release and purification function of the coating through the synergistic strategy of endogenous adsorption and exogenous photocatalytic degradation.

Description

Technical Field

[0001] This application relates to the field of coating compositions, and mainly to an indoor air purification material and its preparation method. Background Technology

[0002] Indoor air quality is receiving increasing attention, with volatile organic compounds (VOCs) being one of the main pollutants. Water-based coatings, due to their low VOC content and environmentally friendly properties, have become a preferred alternative to traditional solvent-based coatings. However, even water-based coatings inevitably release trace amounts of VOCs during production, application, and curing. These trace amounts come from residual volatiles in additives such as film-forming agents, preservatives, defoamers, and thickeners, as well as unreacted monomers from emulsion polymerization. While these trace VOCs usually meet national standards, they remain a problem for consumers seeking near-zero VOCs or ultimate indoor air purification. Currently, most water-based coatings with air-purifying functions on the market achieve adsorption and degradation of exogenous VOCs such as formaldehyde, toluene, and odors by adding functional components such as titanium dioxide photocatalysts, activated carbon, zeolite, or room-temperature catalysts, thus having a certain effect on treating pollutants entering the room from the outside. However, existing technologies generally have a significant shortcoming: they do not specifically control the endogenous VOCs released by the coating itself.

[0003] On the one hand, the initial curing stage of the coating may result in localized high VOC concentrations, which contradicts the product's advertised air purification function and directly weakens the actual user experience and purification effect. On the other hand, the endogenous VOCs released by the coating itself can also cause poisoning of catalytic components and surface coverage, reducing the purification efficiency and lifespan of exogenous VOCs.

[0004] Therefore, how to reduce the VOCs release of water-based coatings at the source while ensuring their excellent application performance, as well as the physical and chemical properties of the coating film such as scrub resistance, adhesion, and hiding power, and at the same time construct an integrated purification system that can simultaneously treat both endogenous and exogenous VOCs, so that the various functional components inside the coating can work together efficiently to achieve a dynamic balance between pollutant adsorption and degradation, is a key technical challenge that urgently needs to be overcome in the field of ultra-low VOC air-purifying water-based coatings.

[0005] Therefore, existing technologies still need to be improved and developed. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of this application is to provide an indoor air purification material and its preparation method, which aims to solve the problem that existing water-based coatings with air purification functions do not specifically control the endogenous VOCs released by the coating itself.

[0007] The technical solution of this application is as follows: An indoor air purification material, comprising, by weight, the following components: Acrylic emulsion: 40-60 parts by weight; Ultra-low VOCs film-forming aid: 0.5-2 parts by weight; Modified zeolite adsorbent: 2-8 parts by weight; Nanophotocatalyst: 1-5 parts by weight; VOC-free thickener: 0.1-0.5 parts by weight; Defoamer: 0.1-0.3 parts by weight; Wetting and dispersing agent: 0.2-0.8 parts by weight; Water: 20-45 parts by weight; The preparation method of the modified zeolite adsorbent includes the following steps: The zeolite raw material was dried at 100-110℃ for 2-3 hours and then cooled to room temperature. Add zirconia grinding balls at a ball-to-material mass ratio of 8-12:1, and add 0.5-1.0 wt% deionized water as a grinding aid; The ball mill was used for ball milling at a speed of 400-500 rpm. The mill was stopped for 5-15 minutes of cooling after every 20-40 minutes of operation. The ball milling was stopped when the powder D90 ≤ 15μm. The powder was collected and dried at 80-100℃ to obtain the modified zeolite adsorbent.

[0008] The indoor air purification material, by weight, further comprises the following components: Conductive polymer-carbon nanotube composite antistatic agent: 5-20 parts by weight; Antibacterial agent: 0.05-0.2 parts by weight; The conductive polymer-carbon nanotube composite antistatic agent is an aqueous dispersion of conductive polymer and carbon nanotubes, with a solid content of 1-3 wt% and a mass ratio of conductive polymer to carbon nanotubes of 10:1. The conductive polymer is one of polyaniline, polypyrrole, and PEDOT:PSS; The antibacterial agent is one or more of Ag nanoparticles, ZnO nanoparticles, and TiO2 nanoparticles.

[0009] The indoor air purification material, wherein the preparation method of the conductive polymer-carbon nanotube composite antistatic agent includes the following steps: Take 0.10g of the carbon nanotubes, add 23mL of deionized water, add 0.01g of Tween 80 as a surfactant, and ultrasonically disperse at room temperature for 1h to obtain a carbon nanotube dispersion. Add 76.92g of PEDOT:PSS aqueous dispersion with a solid content of 1.3wt%, stir at room temperature for 2h to obtain the conductive polymer-carbon nanotube composite antistatic agent.

[0010] The indoor air purification material, wherein the acrylic emulsion is one of styrene-acrylic emulsion, pure acrylic emulsion, and silicone-acrylic emulsion; The ultra-low VOCs film-forming aid is one of alcohol esters or diol ethers; The VOC-free thickener is one of cellulose ethers, polyurethane thickeners, acrylic thickeners, etc.

[0011] The indoor air purification material, wherein the nano-photocatalyst is one or both of anatase TiO2 and rutile TiO2.

[0012] The indoor air purification material, wherein the defoamer is one of organosilicon, mineral oil, or polyether. The wetting and dispersing agent is one of polycarboxylate, polyacrylate, or polyether-modified siloxane.

[0013] The indoor air purification material, by weight, further comprises the following components: Preservative: 0.3-0.5 parts by weight; pH adjuster: Dosage is used to adjust the pH value to 8.0-9.0.

[0014] The indoor air purification material, wherein the preservative is Kathon; The pH adjuster is an organic amine AMP-95.

[0015] A method for preparing an indoor air purification material as described in any of the preceding claims, comprising the following steps: (1) First add water, then add wetting and dispersing agent, defoamer and part of VOCs-free thickener in sequence, stir at 100-200 rpm to disperse evenly; wherein, the amount of the part of VOCs-free thickener added accounts for 10-50% of the total weight of VOCs-free thickener; (2) While stirring, add the modified zeolite adsorbent, stir at 1500-2500 rpm to disperse evenly, add the nano photocatalyst, stir at 1500-2500 rpm to disperse evenly, and obtain the slurry; wherein, the temperature is controlled not to exceed 45°C. (3) Reduce the rotation speed to 300-500 rpm, add acrylic emulsion, and continue stirring to disperse evenly; (4) While stirring, add the ultra-low VOCs film-forming aid and the remaining VOCs-free thickener in sequence and disperse them evenly.

[0016] The method for preparing the indoor air purification material, wherein in step (2), after adding the nano-photocatalyst and stirring at 1500-2500 rpm to achieve uniform dispersion, further includes the following steps: The conductive polymer-carbon nanotube composite antistatic agent and antibacterial agent are added in batches, and the mixture is dispersed evenly at a speed of 1800-2800 rpm after each batch is added; the total dispersion time in step (2) is controlled to be within 60 minutes. Following step (4), the following steps are also included: Prepare an AMP-95 solution with a mass of 5-10%, add the AMP-95 solution dropwise, and adjust the pH of the system to 8.0-9.0; Add preservatives and disperse evenly.

[0017] Beneficial effects: The indoor air purification material of this application achieves a balance between VOCs release and purification function of the coating through a synergistic strategy of endogenous adsorption and exogenous photocatalytic degradation. Detailed Implementation

[0018] This application provides an indoor air purification material and its preparation method. To make the purpose, technical solution, and effects of this application clearer and more explicit, the following provides a more detailed description. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.

[0019] This application provides an indoor air purification material, which is a water-based coating with ultra-low VOCs release and high-efficiency VOCs purification function, comprising the following components by weight: Acrylic emulsion: 40-60 parts by weight; Ultra-low VOCs film-forming aid: 0.5-2 parts by weight; Modified zeolite adsorbent: 2-8 parts by weight; Nanophotocatalyst: 1-5 parts by weight; VOC-free thickener: 0.1-0.5 parts by weight; Defoamer: 0.1-0.3 parts by weight; Wetting and dispersing agent: 0.2-0.8 parts by weight; Water: 20-45 parts by weight; Preservative: 0.3-0.5 parts by weight; pH adjuster: Dosage is used to adjust the pH value to 8.0-9.0.

[0020] The acrylic emulsion can be one of styrene-acrylic emulsion, pure acrylic emulsion, silicone-acrylic emulsion, etc. In the embodiments of this application, styrene-acrylic emulsion, BASF's ACRONAL 6292, is used.

[0021] Ultra-low VOCs film-forming aids can be one of alcohol esters or diol ethers. In the embodiments of this application, the used is dodecyl alcohol ester, Eastman Chemical's Texanol ester alcohol.

[0022] Modified zeolite adsorbents can be made from natural or synthetic zeolite. In the embodiments of this application, the zeolite raw material used is X-type zeolite (synthetic zeolite), specifically Jiangxi Xintao's 13X molecular sieve (model: 13X-HP). Before use, the 13X molecular sieve needs to be pretreated, including the following steps: The 13X molecular sieve was dried at 100-110℃ for 2-3 hours and then cooled to room temperature. Add zirconia grinding balls (graded Φ5mm:Φ3mm:Φ1mm=2:5:3) at a ball-to-material mass ratio of 8-12:1, and add 0.5-1.0wt% deionized water as a grinding aid. The ball mill was used for ball milling at a speed of 400-500 rpm. The mill was stopped for 5-15 minutes of cooling after every 20-40 minutes of operation. The ball milling was stopped when the powder D90 ≤ 15μm. Collect the powder and dry it at 80-100℃ to obtain the modified zeolite adsorbent.

[0023] Since 13X molecular sieves are generally large particles and cannot be directly added to coatings, they must be ground to a D90 ≤ 15μm before use to ensure uniform dispersion of the powder in the aqueous system, avoiding sedimentation and affecting the smoothness of the coating film. Simultaneously, the impact and shear stress generated during ball milling can break the Si-O-Si and Si-O-Al bridging oxygen bonds on the surface and edges of the 13X molecular sieve, forming a large number of coordinated unsaturated dangling bonds and surface free radicals. These highly active free radicals undergo in-situ hydrolysis with trace amounts of water molecules in the system, enriching the particle surface with silanol groups (Si-OH) and aluminumol groups (Al-OH). These surface hydroxyl functional groups not only enhance the adsorbent's affinity for polar VOCs such as formaldehyde, but also maintain the regular microporous structure of the ball-milled zeolite, whose strong pore binding force can still effectively capture non-polar VOCs such as toluene through van der Waals forces.

[0024] The nano-photocatalyst can be one or both of anatase TiO2 and rutile TiO2. In the embodiments of this application, Evonik Degussa P25 titanium dioxide (model: Aeroxide TiO2P25) is used.

[0025] The VOC-free thickener can be one of cellulose ethers, polyurethane thickeners, acrylic thickeners, etc. In the embodiments of this application, hydroxyethyl cellulose, specifically Tylose HS100000 YP2 from SE Tylose GmbH & Co. KG, Germany, is used.

[0026] The defoamer can be one of the following: silicone, mineral oil, polyether, etc. In the embodiments of this application, a silicone defoamer, BYK-024 from BYK Chemicals, is used.

[0027] The wetting and dispersing agent can be one of polycarboxylates, polyacrylates, polyether-modified siloxanes, etc. In the embodiments of this application, a polycarboxylate wetting and dispersing agent, BYK-190 from BYK Chemicals, is used.

[0028] Other additives include, but are not limited to, preservatives and pH adjusters. In the embodiments of this application, other additives are pH adjusters and preservatives. The preservative can be Kathon (DuPont's Kathon LX 1.5%), and the amount used is 0.3-0.5 parts by weight; the pH adjuster can be the organic amine AMP-95, and the amount used is to adjust the pH of the system to between 8.0 and 9.0.

[0029] The indoor air purification material of this application achieves a balance between VOCs release and purification function of the coating through a synergistic strategy of endogenous adsorption and exogenous photocatalytic degradation.

[0030] Firstly, the acrylic emulsion, as the main film-forming substance in the coating, is itself selected as a low-VOCs type, reducing the introduction of VOCs at the source. The selection of ultra-low VOCs film-forming aids further ensures extremely low release of volatile substances during the film-forming process. These aids slowly volatilize during film formation, promoting the fusion of emulsion particles to form a dense coating film, but their volatilization rate and amount are strictly controlled. Firstly, by selecting ultra-low VOCs acrylic emulsions and film-forming aids, the amount of VOCs generated is reduced at the source. Secondly, for the trace amounts of VOCs that inevitably escape during film formation, the modified zeolite adsorbent uniformly distributed within the coating can capture and enrich them instantly, effectively preventing their diffusion into the indoor air, thus achieving effective control over the entire process of VOCs from generation to emission.

[0031] Secondly, the core innovation of this application lies in the synergistic effect of modified zeolite adsorbent and nano-photocatalyst. The modified zeolite adsorbent possesses a regular pore structure and a large specific surface area. Its abundant hydroxyl groups can form hydrogen bonds with polar VOCs molecules such as formaldehyde, or adsorb non-polar VOCs such as toluene through van der Waals forces. Moreover, the modified zeolite exhibits reversible physical adsorption; the adsorbed VOCs molecules can desorb at the interface, migrate to the surface of the nano-photocatalyst, and be oxidized and decomposed. The adsorption sites are continuously regenerated, ensuring the long-lasting purification function.

[0032] The nano-photocatalyst is uniformly dispersed in the coating. When indoor light (including visible light) irradiates the coating surface, TiO2 is excited to generate electron-hole pairs. These electron-hole pairs react with water molecules and oxygen adsorbed on the coating surface to generate highly reactive hydroxyl radicals (·OH) and superoxide radicals (·O2). - These free radicals have extremely strong oxidizing power and can efficiently degrade endogenous VOCs adsorbed by modified zeolite adsorbents as well as exogenous VOCs diffused from indoor air to the coating surface, oxidizing and decomposing them into harmless carbon dioxide and water.

[0033] Third, the absence of VOCs thickeners and the selection of other optimized additives further reduce the overall VOCs content of the coating, ensuring the environmental friendliness of the coating system.

[0034] In this application, the strategy of combining endogenous adsorption with exogenous photocatalytic degradation achieves full-chain management of VOCs from source control to process purification through rapid capture by physical adsorption and thorough degradation by chemical catalysis, effectively resolving the contradiction between the release of VOCs from the coating itself and its environmental purification function.

[0035] Furthermore, the indoor air purification material of this application, by weight, also includes the following components: Conductive polymer-carbon nanotube composite antistatic agent (aqueous dispersion, solid content 1-3wt%): 5-20 parts by weight; Antibacterial agent: 0.05-0.2 parts by weight.

[0036] By introducing conductive polymer-carbon nanotube composite antistatic and antibacterial agents, the volume resistivity and surface resistivity of the paint film are reduced, eliminating accumulated static charge on the surface and reducing electrostatic dust adsorption. Simultaneously, it inhibits microbial growth on the coating surface, preventing biofilm formation that covers the photocatalyst. This reduces dust adhesion and microbial growth from both physical and biological perspectives, solving the problem of coating surface contamination affecting photocatalytic efficiency. Furthermore, the optimized formulation improves the coating's density and surface hardness, giving it excellent scrub resistance. By selecting additives with low surface energy and low staining resistance, even if the surface is contaminated, it can be easily removed with a simple damp cloth wipe without damaging the coating or active components.

[0037] The conductive polymer-carbon nanotube composite antistatic agent is an aqueous dispersion of a conductive polymer and carbon nanotubes, with a solid content of 1-3 wt% and a mass ratio of conductive polymer to carbon nanotubes of 10:1. The conductive polymer can be one of polyaniline, polypyrrole, PEDOT:PSS, etc. In the embodiments of this application, the conductive polymer used is an aqueous dispersion of PEDOT:PSS, Baytron P VP AI 4083, and the mass ratio of PEDOT:PSS to carbon nanotubes is 10:1. The conductive polymer-carbon nanotube composite antistatic agent can also be prepared using other existing methods, and is not limited to the following preparation methods.

[0038] In the embodiments of this application, the preparation method of the conductive polymer-carbon nanotube composite antistatic agent includes the following steps: Take 0.10g of carbon nanotubes, add 23mL of deionized water, add 0.01g of Tween 80 as a surfactant, and sonicate at room temperature for 1h to obtain a carbon nanotube dispersion. Add 76.92g of PEDOT:PSS aqueous dispersion (solid content 1.3wt%) and stir at room temperature for 2h to obtain a conductive polymer-carbon nanotube composite antistatic agent.

[0039] The antibacterial agent can be a single or composite antibacterial agent composed of Ag nanoparticles, ZnO nanoparticles, TiO2 nanoparticles, etc. In the embodiments of this application, the antibacterial agent used is a nano-silver-zinc oxide composite antibacterial agent, specifically the silver-zinc composite antibacterial powder KP-J67 from Kopuyin. The nano-silver-zinc oxide composite antibacterial agent can be purchased directly or prepared using existing methods (co-precipitation method).

[0040] This application also provides a method for preparing the above-mentioned indoor air purification material, including the following steps: 1. Pre-dispersion stage: First, add water, then add wetting and dispersing agent, defoamer, and some VOC-free thickener in sequence. Stir at 100-200 rpm for 5-10 minutes to ensure that the additives are fully dissolved and evenly dispersed.

[0041] In this step, the amount of VOC-free thickener added accounts for 10-50% of the total weight of the VOC-free thickener.

[0042] 2. High-speed dispersion stage of active components: While maintaining stirring, slowly add the modified zeolite adsorbent and stir at 1500-2500 rpm for 15-20 minutes. Slowly add the nano-photocatalyst and stir at 1500-2500 rpm for 15-40 minutes. Add the conductive polymer-carbon nanotube composite antistatic agent and antibacterial agent in batches and slowly, stirring at 1800-2800 rpm for 10-30 minutes after each batch. Control the total dispersion time of step 2 to within 60 minutes to obtain the slurry.

[0043] In this step, monitor the dispersion fineness (using a scraper fineness gauge, requiring a fineness of less than 20 micrometers) to ensure that the powder particles are fully wetted, deagglomerated, and uniformly dispersed to form a stable slurry without agglomeration. During dispersion, the temperature should be controlled not to exceed 45°C, and cooling may be performed if necessary.

[0044] In this step, using the above feeding sequence, different dispersion speeds, and different dispersion times can help achieve the optimal dispersion state of the active components in the coating system, promote the full exposure of these functional components on their active surfaces, and thus maximize their synergistic adsorption and catalytic degradation efficiency.

[0045] 3. Emulsion mixing stage: Reduce the speed to 300-500 rpm, slowly add the acrylic emulsion, and continue stirring for 20-40 minutes until fully mixed.

[0046] In this step, the rotation speed needs to be reduced to avoid excessive shear force that could cause the emulsion to break down.

[0047] 4. Additives and Adjustment Stage: While stirring, add the ultra-low VOCs film-forming aid and the remaining VOCs-free thickener in sequence, and stir for 15-20 minutes to ensure that the ultra-low VOCs film-forming aid and thickener are evenly dispersed and function properly. Prepare an AMP-95 solution with a mass of 5-10%, and slowly add the AMP-95 solution dropwise to adjust the pH of the system to 8.0-9.0. This step needs to be carried out slowly and monitored in real time to avoid excessive pH fluctuations that could affect the stability of the system. Add preservatives and stir for 10-15 minutes to obtain indoor air purification materials.

[0048] 5. Filtration and Packaging: The final prepared indoor air purification material is filtered through a 100-200 mesh filter to remove any coarse particles or impurities; it is then filled into clean, dry packaging containers and sealed for storage.

[0049] The present application will be further described below through specific embodiments.

[0050] The modified zeolite adsorbent used in the following examples was prepared from 13X molecular sieve through the following pretreatment: The 13X molecular sieve was dried at 105℃ for 3 hours and then cooled to room temperature. Add zirconia grinding balls (graded Φ5mm:Φ3mm:Φ1mm=2:5:3) at a ball-to-material mass ratio of 10:1, and add 1.0wt% deionized water as a grinding aid. A planetary ball mill was used for ball milling at a speed of 450 rpm. The mill was stopped for 10 minutes of cooling every 30 minutes of operation. The ball milling was stopped when the powder D90 ≤ 15 μm. The powder was collected and dried at 90°C to obtain the modified zeolite adsorbent.

[0051] Example 1 This embodiment provides an indoor air purification material, which, by weight, comprises the following raw materials: Acrylic emulsion: 50 parts by weight; Ultra-low VOCs film-forming aid: 1 part by weight; Modified zeolite adsorbent: 5 parts by weight; Nanophotocatalyst: 3 parts by weight; VOC-free thickener: 0.3 parts by weight; Defoamer: 0.2 parts by weight; Wetting and dispersing agent: 0.5 parts by weight; Water: 38 parts by weight; Preservative: 0.5 parts by weight; pH adjuster: Dosage is used to adjust the pH value to 8.6.

[0052] The method for preparing the indoor air purification material in this embodiment includes the following steps: 1. Pre-dispersion stage: First, add water, then add wetting and dispersing agent, defoamer, and some VOC-free thickener in sequence, and stir at 150 rpm for 8 minutes.

[0053] In this step, the amount of VOC-free thickener added accounts for 30% of the total weight of VOC-free thickener.

[0054] 2. High-speed dispersion stage of active components: While maintaining stirring, slowly add the modified zeolite adsorbent, stir at 2000 rpm for 18 minutes, slowly add the nano photocatalyst, and stir at 2200 rpm for 35 minutes to obtain the slurry.

[0055] In this step, the temperature is controlled at around 35°C, and the dispersion fineness reaches 18 micrometers.

[0056] 3. Emulsion mixing stage: Reduce the speed to 400 rpm, slowly add the acrylic emulsion, and stir continuously for 30 minutes to mix thoroughly.

[0057] In this step, the rotation speed needs to be reduced to avoid excessive shear force that could cause the emulsion to break down.

[0058] 4. Additives and Adjustment Stage: While stirring, add the ultra-low VOCs film-forming aid and the remaining thickener in sequence, and stir for 18 minutes; Prepare a 5% (w / w) AMP-95 solution, slowly add the AMP-95 solution dropwise, and adjust the pH of the system to 8.6; Add preservatives and stir for 12 minutes to obtain indoor air purification materials.

[0059] 5. Filtration and Packaging: Filter through a 150-mesh filter, fill into clean, dry packaging containers, and seal for storage.

[0060] The product prepared in this embodiment was subjected to performance testing. The test methods and results are as follows: (1) Total volatile organic compounds (TVOC) and formaldehyde release test: Refer to the test equipment and test conditions of the environmental test chamber specified in GB / T 43353-2023 "Odor release test of building materials products - environmental test chamber method", place the coating sample in the standard environmental test chamber, and release it continuously at constant temperature and humidity for 7 days under (23±0.5)°C and (45±3)%RH. On the 7th day, collect the gas in the chamber and determine the release concentration of total volatile organic compounds (TVOC) and formaldehyde release concentration according to the test method specified in GB 18582-2020 "Limits of harmful substances in wall coatings for building".

[0061] Test results: Total volatile organic compound (TVOC) release was 0.03 mg / m³. 3 (Day 7) Formaldehyde release was 0.01 mg / m³ 3 (Day 7) All values ​​were far below the national standard limit.

[0062] (2) Formaldehyde and toluene purification efficiency and purification durability: Referring to JC / T 1074-2008 "Purification Performance of Indoor Air Purification Functional Coating Materials", the test light source was a visible light source simulating the indoor environment, and the light intensity was adjusted to 500 Lux. A fixed amount of formaldehyde and toluene pollutants were re-introduced into the test chamber every day, and the 500 Lux light was continuously circulated for 7 days. The purification efficiency was the removal rate 24 hours after the first introduction of the target pollutants; the purification durability was the removal rate obtained after a saturation test with a fixed amount of target pollutants re-introduced every day for 7 consecutive days, followed by a 24-hour purification test. The obtained removal rate is the long-term purification durability index, which can reflect the coating's ability to resist saturation and continuously decompose pollutants over a long period of time.

[0063] Test results: The purification efficiency was 80% 24 hours after the first introduction of formaldehyde, and the purification effect lasted for 7 days (71%). The purification efficiency was 70% 24 hours after the first introduction of toluene, and the purification effect lasted for 7 days (60%).

[0064] (3) Scrub resistance test: GB / T 9266-2009 "Determination of scrub resistance of architectural coatings".

[0065] Test results: The coating withstood 2000 scrub cycles without breaking or exposing the substrate.

[0066] (4) Surface antistatic property test: The test shall be conducted in accordance with GB / T 31838.3-2019 "Dielectric and resistive properties of solid insulating materials - Part 3: Resistive properties (DC method) - Surface resistance and surface resistivity".

[0067] Test results: Surface resistivity > 1×10 12 Ω, has no antistatic effect, and easily attracts dust from the air.

[0068] (5) Antibacterial performance test: According to GB / T 21866-2008 "Determination of antibacterial properties and antibacterial effect of antibacterial coatings (films)".

[0069] Test results: The antibacterial rate against Escherichia coli and Staphylococcus aureus was only 12% and 9% respectively after 24 hours, with no significant antibacterial effect.

[0070] (6) Easy-to-clean performance test: The stain resistance test was conducted in accordance with GB / T 9780-2013 "Test method for stain resistance of architectural coatings".

[0071] Test results: The stain resistance rating for everyday stains such as coffee, cooking oil, and blue-black ink is level 6. Obvious stain residue remains after wiping, indicating that the cleaning performance is average.

[0072] Example 2 This embodiment provides an indoor air purification material, which, by weight, comprises the following raw materials: Acrylic emulsion: 45 parts by weight; Ultra-low VOCs film-forming aid: 0.8 parts by weight; Modified zeolite adsorbent: 4 parts by weight; Nanophotocatalyst: 2.5 parts by weight; VOC-free thickener: 0.25 parts by weight; Defoamer: 0.15 parts by weight; Wetting and dispersing agent: 0.4 parts by weight; Water: 45 parts by weight; Preservative: 0.4 parts by weight; pH adjuster: Dosage is used to adjust the pH value to 8.5.

[0073] The preparation method of the indoor air purification material in this embodiment is the same as that in Embodiment 1.

[0074] The product prepared in this embodiment was subjected to performance testing, using the same testing method as in Example 1. The test results are as follows: (1) Total volatile organic compounds (TVOC) and formaldehyde emission test: The total volatile organic compounds (TVOC) emission was 0.04 mg / m³. 3 (Day 7) Formaldehyde release was 0.015 mg / m³ 3 (Day 7).

[0075] (2) Purification efficiency and durability of formaldehyde and toluene: The purification efficiency was 81% 24 hours after the first introduction of formaldehyde, and the durability of the purification effect (after 7 days) was 71%; the purification efficiency was 65% 24 hours after the first introduction of toluene, and the durability of the purification effect (after 7 days) was 58%.

[0076] (3) Scrub resistance test: The coating film was not damaged and the substrate was exposed after 1800 scrub cycles.

[0077] (4) Surface antistatic property test: Surface resistivity > 1×10 12 Ω, has no antistatic effect, and easily attracts dust from the air.

[0078] (5) Antibacterial performance test: The antibacterial rate against Escherichia coli and Staphylococcus aureus was only 10% and 7% respectively after 24 h, with no obvious antibacterial effect.

[0079] (6) Easy-to-clean performance test: The stain resistance level of coffee, cooking oil, blue and black ink and other daily stains is level 6. After wiping, there are obvious stains left, and the easy-to-clean performance is average.

[0080] Example 3 This embodiment provides an indoor air purification material, which, by weight, comprises the following raw materials: Acrylic emulsion: 50 parts by weight; Ultra-low VOCs film-forming aid: 1 part by weight; Modified zeolite adsorbent: 5 parts by weight; Nanophotocatalyst: 3 parts by weight; VOC-free thickener: 0.3 parts by weight; Defoamer: 0.2 parts by weight; Wetting and dispersing agent: 0.5 parts by weight; Water: 35 parts by weight; Preservative: 0.5 parts by weight; pH adjuster: Dosage is sufficient to adjust the pH value to 8.6; Conductive polymer-carbon nanotube composite antistatic agent: 15 parts by weight; Antibacterial agent: 0.1 parts by weight.

[0081] The method for preparing the indoor air purification material in this embodiment includes the following steps: 1. Pre-dispersion stage: First, add water, then add wetting and dispersing agent, defoamer, and some VOC-free thickener in sequence, and stir at 150 rpm for 8 minutes.

[0082] In this step, the amount of VOC-free thickener added accounts for 30% of the total weight of VOC-free thickener.

[0083] 2. High-speed dispersion stage of active components: While maintaining stirring, slowly add the modified zeolite adsorbent and stir at 2000 rpm for 18 minutes. Then, slowly add the nano-photocatalyst and stir at 2200 rpm for 15 minutes. Add the conductive polymer-carbon nanotube composite antistatic agent and antibacterial agent in batches, stirring at 2500 rpm for 10 minutes after each batch. Control the total dispersion time in step 2 to 60 minutes to obtain the slurry.

[0084] In this step, the temperature is controlled at around 35°C, and the dispersion fineness reaches 12 micrometers.

[0085] 3. Emulsion mixing stage: Reduce the speed to 400 rpm, slowly add the acrylic emulsion, and stir continuously for 30 minutes to mix thoroughly.

[0086] In this step, the rotation speed needs to be reduced to avoid excessive shear force that could cause the emulsion to break down.

[0087] 4. Additives and Adjustment Stage: While stirring, add the ultra-low VOCs film-forming aid and the remaining thickener in sequence, and stir for 18 minutes; Prepare a 5% (w / w) AMP-95 solution, slowly add the AMP-95 solution dropwise, and adjust the pH of the system to 8.6; Add preservatives and stir for 12 minutes to obtain indoor air purification materials.

[0088] 5. Filtration and Packaging: Filter through a 200-mesh filter, fill into clean, dry packaging containers, and seal for storage.

[0089] The preparation method of the indoor air purification material in this embodiment is the same as that in Embodiment 1.

[0090] The product prepared in this embodiment was subjected to performance testing, using the same testing method as in Example 1. The test results are as follows: (1) Total volatile organic compounds (TVOC) and formaldehyde emission test: The total volatile organic compounds (TVOC) emission was 0.02 mg / m³. 3 (Day 7) Formaldehyde release was 0.005 mg / m³ 3 (Day 7).

[0091] (2) Formaldehyde and toluene purification efficiency and purification durability: The purification efficiency was 92% after the first introduction of formaldehyde in 24 hours, and the purification effect durability (after 7 days) was 84%; the purification efficiency was 85% after the first introduction of toluene in 24 hours, and the purification effect durability (after 7 days) was 80%.

[0092] (3) Scrub resistance test: The coating film was not damaged and the substrate was exposed after 3000 scrub cycles.

[0093] (4) Surface antistatic property test: Surface resistivity <1×10 9 Ω has excellent antistatic properties.

[0094] (5) Antibacterial performance test: The antibacterial rate against Escherichia coli and Staphylococcus aureus is >99.9%.

[0095] (6) Easy-to-clean performance test: The stain resistance level of typical household stains such as coffee, cooking oil, and blue-black ink is level 8. Very little stain residue remains after wiping, indicating that the coating surface is easy to wipe clean after being contaminated, and has excellent easy-to-clean performance.

[0096] Example 4 This embodiment provides an indoor air purification material, which, by weight, comprises the following raw materials: Acrylic emulsion: 48 parts by weight; Ultra-low VOCs film-forming aid: 0.9 parts by weight; Modified zeolite adsorbent: 6 parts by weight; Nanophotocatalyst: 4 parts by weight; VOC-free thickener: 0.35 parts by weight; Defoamer: 0.25 parts by weight; Wetting and dispersing agent: 0.6 parts by weight; Water: 30 parts by weight; Preservative: 0.6 parts by weight; pH adjuster: Dosage is sufficient to adjust the pH value to 8.7; Conductive polymer-carbon nanotube composite antistatic agent: 15 parts by weight; Antibacterial agent: 0.1 parts by weight.

[0097] The preparation method of the indoor air purification material in this embodiment is the same as that in Embodiment 3.

[0098] The product prepared in this embodiment was subjected to performance testing, using the same testing method as in Example 1. The test results are as follows: (1) Total volatile organic compounds (TVOC) and formaldehyde emission test: The total volatile organic compounds (TVOC) emission was 0.015 mg / m³. 3 (Day 7), formaldehyde release was 0.003 mg / m³. 3 (Day 7).

[0099] (2) Formaldehyde and toluene purification efficiency and purification durability: The purification efficiency was 95% after the first introduction of formaldehyde in 24 hours and the purification effect durability (after 7 days) was 90%; the purification efficiency was 88% after the first introduction of toluene in 24 hours and the purification effect durability (after 7 days) was 82%.

[0100] (3) Scrub resistance test: The coating film was not damaged and the substrate was exposed after 3,500 scrub cycles.

[0101] (4) Surface antistatic property test: Surface resistivity <5×10 8 Ω has excellent antistatic properties.

[0102] (5) Antibacterial performance test: The antibacterial rate against Escherichia coli and Staphylococcus aureus is >99.9%.

[0103] (6) Easy-to-clean performance test: The stain resistance level of typical household stains such as coffee, cooking oil, and blue-black ink is level 8. Very little stain residue remains after wiping, indicating that the coating surface is easy to wipe clean after being contaminated, and has excellent easy-to-clean performance.

[0104] Comparative Example 1 A commercially available brand of odor-free interior wall paint, which only meets basic environmental protection requirements and lacks active air purification, antistatic, and antibacterial functions, was used for performance testing. The testing method was the same as in Example 1, and the test results are as follows: (1) Total volatile organic compounds (TVOC) and formaldehyde emission test: The total volatile organic compounds (TVOC) emission was 0.08 mg / m³. 3 (Day 7) Formaldehyde release was 0.03 mg / m³ 3 (Day 7).

[0105] (2) Purification efficiency and persistence of formaldehyde and toluene: The purification efficiency of formaldehyde after the first introduction is <10% in 24 hours, with no obvious purification function; the purification efficiency of toluene after the first introduction is <5% in 24 hours, with no obvious purification function.

[0106] (3) Scrub resistance test: The coating film is slightly damaged after 1000 scrub cycles.

[0107] (4) Surface antistatic property test: Surface resistivity > 1×10 12 Ω, no antistatic effect.

[0108] (5) Antibacterial performance test: The antibacterial rate against Escherichia coli and Staphylococcus aureus is <50%.

[0109] (6) Easy-to-clean performance test: The stain resistance level of coffee, cooking oil, blue and black ink and other daily stains is level 6. After wiping, there are obvious stains left, and the easy-to-clean performance is average.

[0110] Comparative Example 2 A commercially available brand of water-based interior wall paint, which has a "photocatalytic purification" function and contains nano-TiO2, was used for performance testing. The testing method was the same as in Example 1, and the test results are as follows: (1) Total volatile organic compounds (TVOC) and formaldehyde emission test: The total volatile organic compounds (TVOC) emission was 0.06 mg / m³. 3 (Day 7), formaldehyde release was 0.02 mg / m³. 3 (Day 7).

[0111] (2) Formaldehyde and toluene purification efficiency and purification durability: The purification efficiency was 70% after the first introduction of formaldehyde in 24 hours, and the purification effect durability (after 7 days) was 55%; the purification efficiency was 55% after the first introduction of toluene in 24 hours, and the purification effect durability (after 7 days) was 45%.

[0112] (3) Scrub resistance test: The coating film was slightly damaged after 1500 scrub cycles.

[0113] (4) Surface antistatic property test: Surface resistivity > 1×10 12 Ω, no antistatic effect.

[0114] (5) Antibacterial performance test: The antibacterial rate against Escherichia coli and Staphylococcus aureus is about 70%.

[0115] (6) Easy-to-clean performance test: The stain resistance level for everyday stains such as coffee, cooking oil, and blue-black ink is level 5. After wiping, there are obvious stains left, and the easy-to-clean performance is average.

[0116] By comparing Examples 1-4 with Comparative Examples 1-2, the following conclusions can be drawn: 1. Regarding VOC emissions: Examples 1-4 all exhibited extremely low VOC emissions, far below national standards, and significantly superior to commercially available ordinary environmentally friendly coatings and coatings claiming purification functions. Examples 3-4, through more refined component control and synergistic mechanisms, further reduced TVOC and formaldehyde emissions to even lower levels, demonstrating the advantages of ultimate environmental protection.

[0117] 2. VOCs purification efficiency: Examples 1-4, through the synergistic effect of modified zeolite adsorption and TiO2 photocatalysis, exhibited excellent purification efficiency and durability for formaldehyde and toluene, significantly outperforming Comparative Example 1 (no purification function) and Comparative Example 2 (single photocatalyst purification). Examples 3-4, through a multifunctional anti-fouling surface design, ensured the long-term activity of the photocatalyst, further improving the purification efficiency and durability for formaldehyde and toluene, especially with less performance degradation after long-term use.

[0118] 3. Regarding coating durability: Examples 1-4 all exhibit good scrub resistance, which is superior to Comparative Examples 1-2, indicating that the basic physical properties of the coatings are effectively maintained or even improved while introducing functional components.

[0119] 4. Additional Functions (Unique to the Optimized Formulation): Examples 3-4 successfully endowed the coating with multiple additional functions, including excellent antistatic properties, high-efficiency antibacterial properties, and easy cleaning, by introducing a conductive polymer-carbon nanotube composite antistatic agent and a nano-silver-zinc oxide composite antibacterial agent. These functions were either absent or not significantly effective in the comparative examples. Among them, the antistatic function significantly reduced the electrostatic adsorption of dust; the antibacterial function provided a healthier indoor environment; and the easy-clean function made it easy to wipe and restore the coating surface after it became dirty, effectively solving the problem of surface contamination of photocatalysts.

[0120] In summary, the indoor air purification material provided in this application achieves a balance between ultra-low VOCs release and high-efficiency VOCs purification, which is significantly better than similar products on the market. Furthermore, it also achieves breakthrough performance improvements in multiple dimensions such as easy cleaning, antistatic properties, and antibacterial properties, providing users with a healthier, cleaner, and easier-to-maintain indoor environment.

[0121] It should be understood that the application of this application is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of this application.

Claims

1. An indoor air purification material, characterized in that, Based on parts by weight, it includes the following components: Acrylic emulsion: 40-60 parts by weight; Ultra-low VOCs film-forming aid: 0.5-2 parts by weight; Modified zeolite adsorbent: 2-8 parts by weight; Nanophotocatalyst: 1-5 parts by weight; VOC-free thickener: 0.1-0.5 parts by weight; Defoamer: 0.1-0.3 parts by weight; Wetting and dispersing agent: 0.2-0.8 parts by weight; Water: 20-45 parts by weight; The preparation method of the modified zeolite adsorbent includes the following steps: The zeolite raw material was dried at 100-110℃ for 2-3 hours and then cooled to room temperature. Add zirconia grinding balls at a ball-to-material mass ratio of 8-12:1, and add 0.5-1.0 wt% deionized water as a grinding aid; The ball mill was used for ball milling at a speed of 400-500 rpm. The mill was stopped for 5-15 minutes of cooling after every 20-40 minutes of operation. The ball milling was stopped when the powder D90 ≤ 15μm. The powder was collected and dried at 80-100℃ to obtain the modified zeolite adsorbent.

2. The indoor air purification material according to claim 1, characterized in that, The indoor air purification material, by weight, also includes the following components: Conductive polymer-carbon nanotube composite antistatic agent: 5-20 parts by weight; Antibacterial agent: 0.05-0.2 parts by weight; The conductive polymer-carbon nanotube composite antistatic agent is an aqueous dispersion of conductive polymer and carbon nanotubes, with a solid content of 1-3 wt% and a mass ratio of conductive polymer to carbon nanotubes of 10:

1. The conductive polymer is one of polyaniline, polypyrrole, and PEDOT:PSS; The antibacterial agent is one or more of Ag nanoparticles, ZnO nanoparticles, and TiO2 nanoparticles.

3. The indoor air purification material according to claim 2, characterized in that, The preparation method of the conductive polymer-carbon nanotube composite antistatic agent includes the following steps: Take 0.10g of the carbon nanotubes, add 23mL of deionized water, add 0.01g of Tween 80 as a surfactant, and ultrasonically disperse at room temperature for 1h to obtain a carbon nanotube dispersion. Add 76.92g of PEDOT:PSS aqueous dispersion with a solid content of 1.3wt%, stir at room temperature for 2h to obtain the conductive polymer-carbon nanotube composite antistatic agent.

4. The indoor air purification material according to claim 1, characterized in that, The acrylic emulsion is one of styrene-acrylic emulsion, pure acrylic emulsion, and silicone-acrylic emulsion; The ultra-low VOCs film-forming aid is one of alcohol esters or diol ethers; The VOC-free thickener is one of cellulose ether, polyurethane thickener, or acrylic thickener.

5. The indoor air purification material according to claim 1, characterized in that, The nano-photocatalyst is one or both of anatase TiO2 and rutile TiO2.

6. The indoor air purification material according to claim 1, characterized in that, The defoamer is one of the following: organosilicon, mineral oil, or polyether. The wetting and dispersing agent is one of polycarboxylate, polyacrylate, or polyether-modified siloxane.

7. The indoor air purification material according to claim 1, characterized in that, The indoor air purification material, by weight, also includes the following components: Preservative: 0.3-0.5 parts by weight; pH adjuster: Dosage is used to adjust the pH value to 8.0-9.

0.

8. The indoor air purification material according to claim 7, characterized in that, The preservative is Kathon; The pH adjuster is an organic amine AMP-95.

9. A method for preparing an indoor air purification material as described in any one of claims 1-8, characterized in that, Includes the following steps: (1) First add water, then add wetting and dispersing agent, defoamer and part of VOCs-free thickener in sequence, stir at 100-200 rpm to disperse evenly; wherein, the amount of the part of VOCs-free thickener added accounts for 10-50% of the total weight of VOCs-free thickener; (2) While stirring, add the modified zeolite adsorbent, stir at 1500-2500 rpm to disperse evenly, add the nano photocatalyst, stir at 1500-2500 rpm to disperse evenly, and obtain the slurry; wherein, the temperature is controlled not to exceed 45°C. (3) Reduce the rotation speed to 300-500 rpm, add acrylic emulsion, and continue stirring to disperse evenly; (4) While stirring, add the ultra-low VOCs film-forming aid and the remaining VOCs-free thickener in sequence and disperse them evenly.

10. The method for preparing the indoor air purification material according to claim 9, characterized in that, In step (2), after adding the nano-photocatalyst and stirring at 1500-2500 rpm to achieve uniform dispersion, the following steps are also included: The conductive polymer-carbon nanotube composite antistatic agent and antibacterial agent are added in batches, and the mixture is dispersed evenly at a speed of 1800-2800 rpm after each batch is added; the total dispersion time in step (2) is controlled to be within 60 minutes. Following step (4), the following steps are also included: Prepare an AMP-95 solution with a mass of 5-10%, add the AMP-95 solution dropwise, and adjust the pH of the system to 8.0-9.0; Add preservatives and disperse evenly.