Anti-condensation air purification two-component coating and preparation method thereof

Abstract

The invention provides an anti-condensation air purification two-component coating and a preparation method thereof, and belongs to the technical field of building coatings. The coating aims to overcome the defect that an existing interior wall coating is difficult to give consideration to environmental friendliness, functionality and physical properties. The coating is composed of a component A liquid material and a component B powder material. The component A comprises a self-made soil modifier prepared from polyvinyl alcohol resin, a treated leftover rice mixture and the like; the component B comprises a modified soil mixture which is treated by a soil foaming agent to form porous particles and borax serving as a cross-linking agent. Through cross-linking reaction of polyvinyl alcohol in the component A and borax in the component B, the bonding strength and cracking resistance of a coating film are improved. In addition, the coating system further comprises a photocatalyst, a physical adsorbent and a negative ion generation material. According to the present invention, by modifying the natural material and the two-component cross-linking system, the coating material is endowed with excellent anti-condensation performance, efficient air purification function and good thick coating cracking resistance on the basis of the environmental protection target.

Description

Technical Field

[0001] This application relates to the field of architectural coatings technology, and in particular to a two-component anti-condensation air-purifying coating and its preparation method. Background Technology

[0002] In humid climates, condensation easily forms on interior wall surfaces due to temperature differences, a phenomenon known as "wall condensation." Wall condensation not only affects the aesthetics of the interior but also easily breeds mold, polluting the indoor environment and thus endangering human health. To address these problems, existing technologies typically employ the following solutions.

[0003] One solution is to use functional latex paints. These coatings typically add porous fillers such as diatomaceous earth and sepiolite to an organic emulsion system to absorb moisture, and are compounded with functional materials such as photocatalysts or negative ion powders to purify the air. However, to ensure film-forming properties and workability, these single-component coatings often require the addition of film-forming aids, antifreeze, and other organic substances, leading to the release of volatile organic compounds and harmful substances such as formaldehyde from the coating, which contradicts the growing environmental protection requirements. Furthermore, when these coatings are applied in thick coats to ensure sufficient moisture absorption, the physical properties of the film, such as crack resistance, are often poor.

[0004] Another option is to use traditional natural clay-based coatings. Although these coatings are made from natural and environmentally friendly raw materials and do not contain harmful substances, they have low bonding strength and poor adhesion. When applied in thick coats, they are prone to cracking and powdering, and their physical properties are difficult to meet the requirements of modern building decoration.

[0005] Therefore, how to provide an interior wall coating that can retain the environmental friendliness of natural materials, achieve efficient anti-condensation and air purification functions, and possess excellent physical properties is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] The purpose of this application is to provide a two-component anti-condensation air-purifying coating and its preparation method, aiming to solve the shortcomings of existing interior wall coatings that are difficult to balance environmental protection, functionality, and physical properties. This coating, while achieving the environmental goals of zero volatile organic compounds and zero formaldehyde, can simultaneously provide excellent moisture-proof and anti-condensation performance and efficient air purification function, aiming to improve the problems of low adhesion strength and easy cracking of thick coatings in traditional clay-based coatings.

[0007] To achieve the above objectives, this application provides a two-component anti-condensation air-purifying coating, comprising a liquid component A and a powder component B. Component A includes a self-made soil modifier and at least one functional additive. The self-made soil modifier is prepared from a mixture of polyvinyl alcohol resin and leftover rice that has been cooked, gelatinized, and ground. Component B includes a modified soil mixture, borax, at least one dispersant, and / or at least one inorganic filler. The modified soil mixture is a mixture of yellow clay that has been treated with a soil foaming agent to form porous microparticles. Furthermore, components A and / or B contain at least one photocatalyst, at least one physical adsorbent, and at least one negative ion generating material.

[0008] Optionally, the weight mixing ratio of component A to component B is 1:3 to 1:3.5.

[0009] Optionally, component B further comprises pine needle powder and bamboo powder that have been soaked in lithium water glass solution as a fiber skeleton.

[0010] Optionally, the bamboo powder has a mesh size of 80-100 mesh.

[0011] Optionally, the photocatalyst comprises anatase nano-titanium dioxide with a particle size of 5-10 nanometers; the physical adsorbent is nano-activated carbon powder with a particle size of 50-100 nanometers; and the negative ion generating material is tourmaline powder and / or zeolite powder.

[0012] Optionally, the method for preparing the homemade soil modifier includes: mixing and gelatinizing water, polyvinyl alcohol resin, a mixture of leftover rice that has been cooked, gelatinized and ground, brown rice flour and plant vine juice, cooling the mixture, and then adding calcium chloride solution and lithium water glass solution to react and obtain the product.

[0013] Optionally, the preparation method of the modified soil mixture includes: mixing yellow clay with an aqueous solution of lime powder, diatomaceous earth, activated carbon powder, and zeolite powder, adding a soil foaming agent and stirring to form porous microparticles, and then drying and pulverizing them to obtain the mixture.

[0014] Optionally, component A is made from the following raw materials in parts by weight: 20-30 parts water, 5-10 parts photocatalyst nano-titanium dioxide dispersion, 5-10 parts formaldehyde-removing emulsion containing chitosan derivatives, 3-5 parts nano-activated carbon powder, 1-3 parts pine needle extract obtained by ethanol reflux extraction and concentration, 1-3 parts photocatalyst air gel, and 40-60 parts self-made soil modifier.

[0015] Optionally, component B is made from the following raw materials in parts by weight: 50-70 parts modified soil mixture, 1-1.5 parts sodium hexametaphosphate, 3-5 parts pine needle powder soaked in lithium water glass solution, 3-5 parts bamboo powder, 5-10 parts additionally added zeolite powder, 5-10 parts light calcium carbonate, 5-10 parts wollastonite powder, 5-10 parts tourmaline powder, and 1-2 parts borax.

[0016] To achieve the above objectives, this application also provides a method for preparing a two-component anti-condensation air-purifying coating, comprising the following steps: preparing a liquid component A, wherein component A comprises a self-made soil modifier and at least one functional additive, the self-made soil modifier being prepared from raw materials comprising polyvinyl alcohol resin and a mixture of leftover rice that has been cooked, gelatinized, and ground; preparing a powder component B, wherein component B comprises a modified soil mixture, borax, at least one dispersant, and / or at least one inorganic filler, the modified soil mixture being a mixture of yellow clay containing porous particles formed by treatment with a soil foaming agent; in the steps of preparing the liquid component A and / or preparing the powder component B, adding at least one photocatalyst, at least one physical adsorbent, and at least one negative ion generating material; and mixing the component A and the component B to obtain the coating.

[0017] Compared with the prior art, this application has the following beneficial effects.

[0018] First, this application fundamentally solves the contradiction in existing technologies where environmental friendliness, functionality, and physical properties are difficult to balance through a unique two-component system based on modified natural materials. The coating contains no organic solvents, achieving the environmental goal of zero free formaldehyde, volatile organic compounds, and benzene compounds. Simultaneously, the cross-linking reaction between the self-made clay modifier (containing polyvinyl alcohol resin) in component A and borax in component B significantly improves the adhesion strength and crack resistance of the coating film, overcoming the defect of traditional clay-based coatings being prone to cracking when applied thickly.

[0019] Secondly, this application exhibits excellent anti-condensation performance. The modified clay mixture in component B, after being treated with a foaming agent, forms porous microparticles, which, together with other porous fillers, construct a three-dimensional network porous structure. This gives the coating a high specific surface area and moisture absorption capacity, enabling it to quickly absorb and release water vapor from the environment, effectively preventing condensation and dampness on the wall surface in humid weather.

[0020] Furthermore, this application possesses a highly efficient and comprehensive air purification function. Air purification is achieved through the synergistic effect of multiple functional materials. The photocatalyst in component A and / or component B can degrade harmful gases under light irradiation, the physical adsorbent is responsible for physical adsorption, and the negative ion generating material can continuously release negative ions, settling dust and bacteria in the air. This achieves multiple purification effects, including photocatalysis, physical adsorption, and negative ion settling.

[0021] Finally, the coating structure of this application is stable and has good workability. The pine needle powder and bamboo powder modified with lithium water glass in component B serve as a fiber skeleton, which enhances the toughness and overall structure of the coating film, supports thick coating application without cracking, and ensures sufficient moisture absorption and functional layer thickness. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 A schematic diagram illustrating the preparation and application process of a two-component anti-condensation air-purifying coating provided in this application embodiment;

[0024] Figure 2 This is a schematic diagram of the preparation process of the key modified materials provided in the embodiments of this application, wherein... Figure 2 (a) is the preparation process of the self-made soil modifier. Figure 2 (b) is the preparation process of the modified soil mixture. Figure 2 (c) is the preparation process of modified pine needle powder;

[0025] Figure 3 This is a schematic diagram illustrating the structure and functional principle of the coating provided in the embodiments of this application.

[0026] Explanation of reference numerals in the attached drawings: 10 - wall substrate; 20 - coating of the present invention; 21 - porous skeleton structure; 22 - functional particles. Detailed Implementation

[0027] To better understand the technical solutions of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It is understood that the specific embodiments described herein are only for explaining this application and not for limiting this application.

[0028] Example 1

[0029] This embodiment provides a two-component anti-condensation air-purifying coating and its preparation method. Please refer to [link / reference]. Figure 1 The figure is a schematic diagram of the preparation and application process of a two-component anti-condensation air-purifying coating provided in an embodiment of this application. The process mainly includes the preparation step S100 of component A (liquid), the preparation step S200 of component B (powder), the mixing step S300 of components A and B, and the final wall application step S400.

[0030] Step S100 is the preparation of component A liquid. In one embodiment of this application, component A is made from the following raw materials in parts by weight: 23 parts water, 5 parts photocatalyst nano-titanium dioxide dispersion, 6 parts formaldehyde removal emulsion, 3 parts activated carbon powder with a particle size of 50-100 nanometers, 2 parts pine needle extract, 1 part photocatalytic air gel, and 60 parts self-made soil modifier.

[0031] The specific preparation process is as follows: Add 23 parts by weight of deionized water to a 200-liter stainless steel stirred tank. Turn on the stirrer and control the speed at 300 rpm. Under these conditions, slowly add 5 parts by weight of photocatalyst nano-titanium dioxide dispersion, 6 parts by weight of formaldehyde removal emulsion, 3 parts by weight of activated carbon powder with a particle size of 50-100 nanometers, 2 parts by weight of pine needle extract, 1 part by weight of photocatalytic air gel, and 60 parts by weight of self-made soil modifier. After all materials have been added, increase the stirring speed to 800 rpm and continue stirring for 60 minutes to ensure that all components are mixed evenly, without agglomeration or precipitation, ultimately forming a stable and homogeneous component A liquid, which is then sealed for later use.

[0032] The photocatalyst nano-titanium dioxide dispersion, as a functional additive, has a solid content of 20%, and the nano-titanium dioxide is anatase with an average particle size of 5-10 nanometers. This component is excited under sunlight or indoor lighting conditions, generating strong oxidizing free radicals, thereby effectively degrading various harmful organic compounds in the air, such as formaldehyde, benzene, toluene, xylene, ammonia, and total volatile organic compounds. The formaldehyde-removing emulsion is also a functional additive; its main active ingredient is a chitosan derivative, which can actively capture free formaldehyde molecules in the air and convert them into harmless stable substances through chemical reactions, thus achieving rapid formaldehyde removal. The activated carbon powder with a particle size of 50-100 nanometers is used as a physical adsorbent; its large specific surface area and abundant microporous structure enable it to efficiently adsorb odor molecules, dust, and some harmful gases in the air. The pine needle extract is obtained by reflux extraction of natural pine needles with ethanol and subsequent concentration; it is rich in natural phytoncides and other substances, and also has certain antibacterial and fragrance-releasing effects. The photocatalytic air gel, as a functional additive, has a porous structure and loaded photocatalytic components that can synergistically enhance the adsorption and degradation of harmful gases.

[0033] In this embodiment, the self-made soil modifier is one of the core raw materials of component A. Please refer to [link / reference]. Figure 2(a) This figure details the preparation process of the homemade soil modifier. The specific preparation method includes: Step S210, mixing and heating the raw materials. In a reaction vessel equipped with a jacketed heating and stirring device, 46 parts by weight of water are first added and the temperature is raised to 35-40°C. Subsequently, under low-speed stirring (approximately 200 rpm), 4 parts of polyvinyl alcohol resin (model 17-99), 40 parts of the treated leftover rice mixture, 7 parts of brown rice flour, and 3 parts of fresh sweet potato vine juice are added sequentially. It should be noted that the treated leftover rice mixture is a fine paste made by thoroughly mixing overnight leftover rice with 10% by weight of lime powder (mainly calcium hydroxide) in a kneader at a 1:1 weight ratio, followed by grinding in a colloid mill. This process utilizes the alkaline environment of lime to promote the initial hydrolysis and modification of starch in the rice. The fresh sweet potato vine juice is obtained by washing fresh sweet potato vines, extracting the juice, and then filtering it through a 200-mesh filter. It provides natural plant colloids and trace elements. Step S211: Gelatinization and Heat Preservation. The above mixture is heated slowly to 95-100℃ by jacket steam heating under continuous stirring, and maintained at this temperature for 40-50 minutes. During this period, the polyvinyl alcohol resin and the starch in the cooked rice and brown rice fully absorb water, swell, and gelatinize, forming a high-viscosity colloidal solution. Step S212: Cooling and Dropwise Addition of Inorganic Salts. After gelatinization is complete, heating is stopped, and the material temperature is lowered to about 40℃ by cooling water in the jacket. Then, while maintaining stirring (about 300 rpm), 3 parts by mass of a 10% calcium chloride solution and 3 parts by a lithium water glass solution with a modulus of 1 are slowly added dropwise using a drop pump. The dropwise addition process is controlled to be completed within 15 minutes, and the reaction continues at this temperature for 30 minutes after the addition is completed. The addition of calcium chloride and lithium silicate allows for slight cross-linking with the hydroxyl groups on the polyvinyl alcohol and starch molecular chains, thereby adjusting the rheological properties of the colloid and enhancing its subsequent reaction activity with borax. Step S213: Filtration yields the finished product. After the reaction, the material is cooled to approximately 30°C and filtered using a 150-mesh vibrating screen to remove any undissolved particles or impurities. The resulting filtrate is the self-made clay modifier. This modifier is a pale yellow viscous liquid, serving as the main binder and modifier in component A, providing excellent adhesion properties and an environmentally friendly foundation for the coating.

[0034] Next, step S200 is performed, namely the preparation of component B powder. In this embodiment, component B is made from the following raw materials in parts by weight: 57 parts modified soil mixture, 1 part sodium hexametaphosphate, 3 parts modified pine needle powder, 3 parts 80-100 mesh bamboo powder, 5 parts 300-500 mesh zeolite powder, 10 parts 300-500 mesh light calcium carbonate, 10 parts 300-500 mesh wollastonite powder, 10 parts 300-500 mesh tourmaline powder, and 1 part borax.

[0035] The specific preparation process is as follows: Weigh the above-mentioned dry powdered raw materials according to their weight proportions, put them into a V-type mixer, and mix them at a speed of 30 rpm for 45 minutes to ensure that all powder components are evenly distributed, and finally obtain the B component powder with good flowability, which is then bagged and sealed for later use.

[0036] Sodium hexametaphosphate, as an inorganic dispersant, effectively prevents the agglomeration of various particles in the powder when mixed with the liquid, thereby improving the uniformity and workability of the coating. Light calcium carbonate and wollastonite powder, as inorganic fillers, are mainly used to adjust the consistency, sandability, and filling properties of the coating, and to reduce costs.

[0037] The core ingredients in component B include modified soil mixture, modified pine needle powder, and various functional powders. Please refer to [link / reference]. Figure 2 (b) This figure details the preparation process of the modified clay mixture. The specific preparation method includes: Step S220, mixing clay with lime powder solution. By weight, first add 32 parts of a 50% lime powder aqueous solution (i.e., lime powder and water mixed in a 1:1 weight ratio) to a high-powered mixer, then add 50 parts of screened and dried yellow clay, and stir at high speed for 15 minutes to ensure the yellow clay particles and lime powder are fully and evenly mixed. Yellow clay is the main raw material constituting the coating skeleton and reflecting a natural texture, while the addition of lime powder (mainly composed of calcium hydroxide and calcium oxide) can increase the alkalinity of the system and also provide certain air-hardening and hydraulic properties, helping to improve the early strength of the coating. Step S221, adding functional fillers. Under continuous stirring, add 5 parts of diatomaceous earth, 5 parts of 200-300 mesh activated carbon powder, and 5 parts of 80-100 mesh zeolite powder to the above mixture, and continue stirring for 10 minutes. Both diatomaceous earth and activated carbon powder are highly porous materials, which can significantly increase the specific surface area and moisture absorption capacity of the mixture. Ruishi powder, as a negative ion generating material, can contribute to air purification. Step S222: Add foaming agent and stir to create pores. Next, add 3 parts of a clay foaming agent (e.g., a compound of sodium dodecyl sulfate and a stabilizer) to the mixture and continue high-speed stirring for 20-30 minutes. Under mechanical shear force, the foaming agent generates a large number of tiny and stable bubbles, which are encapsulated in the clay mixture, thus forming a porous granular structure at the microscopic level. Step S223: Dry and pulverize to obtain the finished product. The foamed, moist granular mixture is fed into a drying device and dried at 80°C until the moisture content is below 2%. Then, the dried lumps are pulverized using an air jet mill, and the powder is screened through a grading sieve to obtain 150-200 mesh powder, which is the modified clay mixture. Because the mixture has undergone foaming and pore-forming treatment, its particles have formed abundant micropores, which is the key to the coating's high moisture absorption performance.

[0038] Please see Figure 2(c) This figure details the preparation process of modified pine needle powder. The specific preparation method includes: Step S230, pine needle powder cutting. The collected dried pine needles are initially cut into small segments of 2-3 cm in length using a grass cutter. Step S231, lithium silicate solution soaking. The cut pine needle segments are added to a lithium silicate solution with a modulus of 1, ensuring all pine needles are submerged in the solution, and soaked for 1 hour. Lithium silicate (lithium silicate), as an inorganic binder, can penetrate into the plant fiber structure of pine needles. On the one hand, it can improve the rigidity and water resistance of the fibers; on the other hand, it can form a thin inorganic silicate film on the fiber surface, thereby enhancing its interfacial bonding with the soil matrix, playing a reinforcing role similar to that of steel bars in concrete. Step S232, drying and pulverizing to obtain the finished product. The soaked pine needles are removed, excess solution is drained, and then dried in an oven at 60℃. Then, they are pulverized using a pulverizer with a sieve, and particles of 80-100 mesh are sieved out to obtain the modified pine needle powder.

[0039] The bamboo powder in component B, selected with a mesh size of 80-100, works together with modified pine needle powder as the fiber skeleton in the coating system. These plant fibers interweave in the coating to form a three-dimensional network, which can effectively resist the shrinkage stress of the coating during drying and use, thereby significantly improving the crack resistance of the coating and providing a feasible guarantee for the application of 1.5-2.5 mm thick coatings.

[0040] Component B also includes tourmaline powder and zeolite powder as negative ion generating materials. A portion of the zeolite powder is added during the preparation of the modified clay mixture, while the other portion (5 parts in this example) is added as an additional component during the mixing of Component B. Tourmaline powder (10 parts in this example) is also added in this step. Both of these natural mineral powders can permanently and spontaneously release negative ions into the air. These negative ions can combine with positively charged particles such as dust, smoke, and bacteria in the air, causing them to agglomerate and settle, thereby purifying the air.

[0041] Borax in component B is one of the key components for improving the mechanical properties of the technical solution in this application. As a crosslinking agent, after components A and B are mixed, it reacts with the hydroxyl groups on the polyvinyl alcohol molecular chains in the self-made clay modifier in component A to form borate ester bonds, thereby constructing a chemical crosslinking network in the entire coating system. This network structure greatly improves the cohesive strength of the coating, its adhesion to the wall substrate, and its water resistance.

[0042] After preparing components A and B, proceed to step S300, which involves mixing and stirring components A and B. In specific application, mix the liquid component A and the powder component B at a weight ratio of 1:3. For example, take 10 kg of liquid component A and 30 kg of powder component B, pour them into a clean mixing bowl, and use a handheld electric mixer to thoroughly mix until a uniform, fine paste without dry powder or lumps is formed. Let it stand for 3-5 minutes to allow the material to fully moisten and mature, then stir slightly before use.

[0043] Finally, proceed to step S400, which involves applying the mixed coating to the wall surface. The mixed coating can be applied evenly to the treated wall substrate 10 using a trowel or spray method to form the coating layer 20 of this invention. The thickness should be controlled between 1.5 and 2.5 mm to ensure sufficient moisture absorption capacity and functional layer thickness. Thanks to the presence of the polyvinyl alcohol-borax crosslinking system, the coating exhibits good fast-drying properties, typically achieving surface dryness after 24 hours and complete curing after 7 days.

[0044] Please see Figure 3 This figure is a schematic diagram illustrating the structure and functional principle of the coating provided in this application embodiment. Inside the cured coating 20, a three-dimensional porous framework structure 21 is constructed from modified clay mixture, diatomaceous earth, bamboo powder, and modified pine needle powder. This structure has a high specific surface area and abundant pores. When indoor air humidity is high (e.g., during the humid season), it can quickly absorb excess water vapor in the air, preventing it from condensing into water droplets on the wall surface, thus effectively preventing condensation and dampness. Conversely, when indoor air becomes dry, the absorbed moisture can be slowly released, playing a certain role in regulating indoor humidity.

[0045] Meanwhile, various functional particles 22, including nano-titanium dioxide, nano-activated carbon powder, tourmaline powder, and zeolite powder, are uniformly distributed within the porous framework structure 21. These functional particles 22 work synergistically to achieve highly efficient air purification. Harmful gases in the air, such as formaldehyde and benzene compounds, are partially physically adsorbed by the nano-activated carbon powder, partially chemically captured by the formaldehyde-removing emulsion, and further degraded into harmless carbon dioxide and water under light conditions by the photocatalysts (nano-titanium dioxide and photocatalytic air gel). In addition, the negative ions continuously released by the tourmaline and zeolite powder can settle dust, PM2.5 particles, and charged bacteria in the air, further improving indoor air quality.

[0046] Testing revealed that the coating obtained in this embodiment exhibits a tensile bond strength of 0.47 MPa, significantly higher than traditional clay-based coatings. No cracking was observed when tested at a thickness of 2.0 mm. Its 24-hour moisture absorption reached 38.5 g / m², and its negative ion release was 3800 ions / cm³. Furthermore, the coating contained zero free formaldehyde, volatile organic compounds, and benzene compounds. Therefore, this product is a green and environmentally friendly interior wall coating that integrates excellent physical properties, highly effective anti-condensation function, and comprehensive air purification capabilities.

[0047] Example 2

[0048] This embodiment provides a high-performance, anti-condensation, two-component air-purifying coating. Its preparation and application process are basically the same as in Example 1, with the main difference being adjustments to the raw material ratios and mixing proportions of components A and B, aimed at further enhancing the coating's air-purifying capabilities and physical properties.

[0049] In this embodiment, the raw materials and their weight parts used to prepare component A liquid (step S100) are as follows: 22 parts water, 6 parts photocatalyst nano-titanium dioxide dispersion, 6 parts formaldehyde-removing emulsion, 4 parts activated carbon powder with a particle size of 50-100 nanometers, 3 parts pine needle extract, 3 parts photocatalytic air gel, and 56 parts self-made soil modifier. Compared with Example 1, this embodiment increases the amount of photocatalyst, activated carbon powder, pine needle extract, and photocatalytic air gel, and correspondingly reduces the amount of water and self-made soil modifier, with the aim of enhancing the air purification and antibacterial functions of the coating. The preparation method of the self-made soil modifier is exactly the same as that described in Example 1.

[0050] The raw materials and their weight parts used to prepare component B powder (step S200) are as follows: 61 parts modified clay mixture, 1.5 parts sodium hexametaphosphate, 5 parts modified pine needle powder, 5 parts 80-100 mesh bamboo powder, 8 parts 300-500 mesh wollastonite powder, 6 parts 300-500 mesh light calcium carbonate, 6 parts 300-500 mesh wollastonite powder, 6 parts 300-500 mesh tourmaline powder, and 1.5 parts borax. Compared with Example 1, this example increases the amount of modified clay mixture, dispersant, fiber skeleton material (pine needle powder and bamboo powder), negative ion generating material (wollastonite powder), and crosslinking agent (borax), while reducing the amount of ordinary inorganic filler (light calcium carbonate and wollastonite powder). This adjustment aims to: 1. Increase the content of porous substrate to improve moisture absorption performance; 2. Increase the fiber content to further enhance crack resistance; 3. Increase the concentration of negative ion generating material to obtain a higher negative ion release; 4. Increase the amount of borax to match the binder content in component A, ensuring sufficient cross-linking reaction and thus improving bonding strength. The preparation methods for the modified soil mixture and the modified pine needle powder are exactly the same as those described in Example 1.

[0051] In mixing step S300, in this embodiment, component A liquid and component B powder are mixed at a weight ratio of 1:3.3. For example, 10 kg of component A liquid and 33 kg of component B powder are taken and stirred evenly with an electric mixer until a lump-free paste is formed. After standing and maturing for 5 minutes, the mixture is then applied.

[0052] Construction step S400 is the same as in Example 1, and the coating is applied to the wall substrate 10 by troweling or spraying. The dry film thickness of the coating 20 is also controlled at 1.5-2.5 mm.

[0053] Due to the optimized formulation, the coating 20 obtained in this embodiment exhibits significant improvements in all performance aspects. Testing revealed that its tensile bond strength increased to 0.51 MPa, demonstrating stronger adhesion; its 24-hour moisture absorption increased to 40.3 g / m², providing superior anti-condensation capabilities; and its negative ion release significantly increased to 5700 ions / cm³, resulting in a substantial enhancement in air purification. Simultaneously, the coating also exhibits excellent crack resistance, while maintaining zero levels of free formaldehyde, volatile organic compounds, and benzene compounds. This embodiment demonstrates that by adjusting the proportions of each component, specific properties of the coating can be optimized and strengthened to meet higher performance requirements.

[0054] Example 3

[0055] This embodiment aims to verify the substitutability of some raw materials in the present application, so as to illustrate the rationality of the scope of protection of this application. Specifically, in this embodiment, the "fresh sweet potato vine juice" used to prepare the homemade soil modifier is replaced with another common raw material rich in plant colloids.

[0056] In this embodiment, the types and weight parts of raw materials for components A and B of the coating, as well as the mixing ratio (1:3) of components A and B, are exactly the same as in Example 1. The only difference lies in the preparation process of the "homemade clay modifier" used in component A.

[0057] The overall process for preparing this homemade soil modifier, including steps S210 (mixing and heating raw materials), S211 (gelatinization and heat preservation), S212 (cooling and adding inorganic salts for reaction), and S213 (filtration to obtain the finished product), as well as the types and amounts of water, polyvinyl alcohol resin, treated leftover rice mixture, brown rice flour, calcium chloride solution, and lithium water glass solution used, are completely consistent with Example 1. The difference is that the 3 parts of "fresh sweet potato vine juice" added in step S210 are replaced with 3 parts of "fresh aloe vera juice". The preparation method of the fresh aloe vera juice is as follows: take fresh aloe vera leaves, remove the outer skin, blend the inner gelatinous pulp into juice using a pulper, and then filter it through a 200-mesh filter.

[0058] Understandably, aloe vera juice, like sweet potato vine juice, is rich in natural polysaccharides and other high-molecular-weight colloidal substances, which can synergistically improve the rheological properties and film-forming properties of the modifier with polyvinyl alcohol and starch. The self-made clay modifier was used to prepare component A liquid, which was then mixed with component B powder to prepare a coating. Application and performance testing were then conducted.

[0059] The results show that the coating obtained in this embodiment has basically the same performance indicators as that in Example 1. Its tensile bond strength is 0.46 MPa, its 24-hour moisture absorption is 38.2 g / m², its negative ion release is 3750 ions / cm³, it does not crack when thickly coated, and its harmful substance content is 0.

[0060] The above results strongly demonstrate that, in the preparation of the self-made soil modifier, the "plant vine juice" as a source of natural plant colloids is not limited to a specific "sweet potato vine juice." Other plant juices with similar chemical composition and physical properties (such as aloe vera juice) can also achieve the technical effects of this application. This indicates that the core of this application lies in utilizing the natural high-molecular substances in such plant juices, rather than relying on a specific plant species, thus verifying the universality and versatility of the technical solution.

[0061] Example 4

[0062] This embodiment aims to verify the flexibility of the functional filler combination in component B of the present application, particularly to demonstrate that the air purification effect does not depend on a specific negative ion generating material. Specifically, this embodiment replaces "Ruishi powder" in component B with another common mineral powder with negative ion releasing function—maifan stone powder.

[0063] In this embodiment, the preparation of component A of the coating, the mixing ratio of component A and component B (1:3), and the application method are exactly the same as in Example 1. The main difference lies in the formulation of component B.

[0064] In preparing the B component powder, the formula is basically the same as in Example 1, except that 5 parts of "300-500 mesh Ruite powder" in the original formula are replaced with 5 parts of "300-500 mesh Maifan stone powder". The types and weights of all other raw materials in component B, including modified clay mixture, sodium hexametaphosphate, modified pine needle powder, bamboo powder, light calcium carbonate, wollastonite powder, tourmaline powder, and borax, remain unchanged. It should be noted that in this example, the raw material formula for preparing the "modified clay mixture" has also been adjusted accordingly; that is, in step S221, the 5 parts of "80-100 mesh Ruite powder" are also replaced with 5 parts of "80-100 mesh Maifan stone powder". This ensures that the entire coating system no longer contains Ruite powder, and that Maifan stone powder and tourmaline powder jointly fulfill the function of the negative ion generating material.

[0065] Maifan stone is a natural silicate mineral that also has a porous structure and ion exchange capacity, and can release a certain amount of negative ions into the environment.

[0066] The powder of component B, prepared using this adjusted formula, was mixed with the liquid of component A from Example 1 to form a coating, which was then applied as a film. The performance of the coating was tested, and the results showed that the coating of this example also exhibited good overall performance. Its negative ion release was measured at 3500 ions / cm³, slightly lower than that of Example 1, but still significantly higher than that of ordinary coatings, reaching a level that effectively purifies the air. Simultaneously, its tensile bond strength was 0.47 MPa, its 24-hour moisture absorption was 38.8 g / m², and its crack resistance, anti-condensation properties, and environmental performance were all comparable to those of Example 1.

[0067] The results of this embodiment demonstrate that the negative ion generating material in the technical solution of this application is not limited to the only combination of tourmaline powder and maifanite powder. Other negative ion generating materials with similar functions (such as maifanite powder) can be used for equivalent replacement, and the desired air purification effect can still be achieved. This proves that the selection of functional materials in this application has a certain degree of flexibility. Its core lies in constructing a composite purification system that includes negative ion generating materials, photocatalysts, and physical adsorbents, rather than relying on a specific combination of materials.

[0068] Comparative Example 1 (Ordinary Clay Coating)

[0069] Component A consists of 30 parts water, and Component B consists of 74 parts yellow clay, 1 part sodium hexametaphosphate, 9 parts light calcium carbonate (400 mesh), 7 parts lime powder (400 mesh), 3 parts unmodified pine needle powder, and 6 parts bamboo powder. The mixing ratio of Component A to Component B is 1:3.3. Simply mix Component A and Component B thoroughly before use.

[0070] Comparative Example 2 (Commercially Available Air Purifying Coating)

[0071] We selected a commercially available brand of air-purifying formaldehyde-removing paint.

[0072] Test method:

[0073] Moisture absorption: Refer to ISO 24353-2008 and NORDTEST methods;

[0074] Moisture and condensation resistance: The test plate was placed in a sealed container and water vapor was introduced for 24 hours before observation.

[0075] Tensile bond strength: tested according to JC / T 2078-2011;

[0076] The remaining items shall be implemented in accordance with the relevant national standards.

[0077] Performance testing

[0078] The coatings of Examples 1 and 2 and Comparative Examples 1 and 2 were made into test panels, and tested after curing for 7 days. The results are as follows:

[0079] Testing items Example 1 Example 2 Comparative Example 1 Comparative Example 2 Moisture-proof and condensation-proof No water droplets or signs of dampness on the surface No water droplets or signs of dampness on the surface No water droplets or signs of dampness on the surface The surface has water droplets and shows signs of dampness. Crack resistance No cracks No cracks Thick coating cracking Thick coating cracking Tensile bond strength 0.47 0.51 0.10 0.43 Moisture absorption (m² / g) 38.5 40.3 28.8 11.5 negative ion release 3800 pieces / cm³ 5700 pieces / cm³ 100 pieces / cm³ 3200 pieces / cm³ Free formaldehyde (mg / kg) 0 0 0 10 VOC content (g / L) 0 0 0 31 Total content of benzene series compounds [limited to benzene, toluene, xylene (including ethylbenzene)] / (mg / kg) 0 0 0 18

[0080] The results show that the coating of the present invention is significantly superior to the control sample in terms of anti-condensation, air purification, environmental protection and physical properties.

[0081] The above description is merely a preferred embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A two-component anti-condensation air-purifying coating, characterized in that, It consists of component A (liquid) and component B (powder); The A component liquid is made from the following materials in parts by weight: 20-30 parts water, 5-10 parts photocatalyst nano-titanium dioxide dispersion, 5-10 parts formaldehyde-removing emulsion containing chitosan derivatives, 3-5 parts nano-activated carbon powder, 1-3 parts pine needle extract obtained by ethanol reflux extraction and concentration, 1-3 parts photocatalyst air gel, and 40-60 parts self-made soil modifier; the A component contains the self-made soil modifier and at least one functional additive, the self-made soil modifier being prepared from raw materials containing polyvinyl alcohol resin and leftover rice that has been cooked, gelatinized, and ground; The B component powder is made from the following materials in parts by weight: 50-70 parts modified clay mixture, 1-1.5 parts sodium hexametaphosphate, 3-5 parts pine needle powder soaked in lithium water glass solution, 3-5 parts bamboo powder, 5-10 parts additionally added zeolite powder, 5-10 parts light calcium carbonate, 5-10 parts wollastonite powder, 5-10 parts tourmaline powder, and 1-2 parts borax; the B component contains modified clay mixture, borax, at least one dispersant and / or at least one inorganic filler, wherein the modified clay mixture is a mixture containing yellow clay that has been treated with a clay foaming agent to form porous microparticles; Furthermore, component A and / or component B contain at least one photocatalyst, at least one physical adsorbent, and at least one negative ion generating material.

2. The coating according to claim 1, characterized in that, The weight mixing ratio of component A to component B is 1:3 to 1:3.

5.

3. The coating according to claim 1 or claim 2, characterized in that, Component B further comprises pine needle powder and bamboo powder, which have been treated with lithium water glass solution as fiber skeleton; wherein the bamboo powder has a mesh size of 80-100 mesh.

4. The coating according to claim 1, characterized in that, The photocatalyst comprises anatase nano-titanium dioxide with a particle size of 5-10 nanometers; the physical adsorbent is nano-activated carbon powder with a particle size of 50-100 nanometers; and the negative ion generating material is tourmaline powder and / or zeolite powder.

5. The coating according to claim 1, characterized in that, The method for preparing the self-made soil modifier includes: mixing and gelatinizing water, polyvinyl alcohol resin, a mixture of leftover rice that has been cooked, gelatinized and ground, brown rice flour and plant vine juice, cooling the mixture and then adding calcium chloride solution and lithium water glass solution to react and obtain the product.

6. The coating according to claim 1, characterized in that, The method for preparing the modified soil mixture includes: mixing yellow clay with an aqueous solution of lime powder, diatomaceous earth, activated carbon powder, and zeolite powder, adding a soil foaming agent and stirring to form porous microparticles, and then drying and pulverizing them to obtain the mixture.

7. A method for preparing a two-component anti-condensation air-purifying coating, characterized in that, Includes the following steps: Prepare component A liquid, wherein component A comprises a self-made soil modifier and at least one functional additive, wherein the self-made soil modifier is prepared from raw materials comprising polyvinyl alcohol resin and a mixture of leftover rice that has been cooked, gelatinized and ground. Prepare component B powder, wherein component B comprises modified clay mixture, borax, at least one dispersant and / or at least one inorganic filler, wherein the modified clay mixture is a mixture containing yellow clay that has been treated with a clay foaming agent to form porous microparticles; In the steps of preparing the liquid component A and / or preparing the powder component B, at least one photocatalyst, at least one physical adsorbent, and at least one negative ion generating material are added. The coating is obtained by mixing component A and component B.

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