Preparation method of stone-like weather-resistant coating

Abstract

The invention discloses a preparation method of a stone-like weather-resistant coating. The method comprises the following steps: preparing a coating base material by taking a water-based resin material, a dispersing agent, a defoaming agent, a mildew preventive and water as raw materials; the preparation method comprises the following steps: by taking oyster shells and a recycled mica material as raw materials, carrying out modification treatment, mixing with quartz sand, nano titanium dioxide powder, white carbon black, industrial bone glue, ethyl carbamate, diphenylthiourea, decanoic acid, sodium carboxymethyl cellulose, a titanate coupling agent and a proper amount of water, and uniformly dispersing to obtain a stone texture imitating component; then mixing the two components in proportion on site, stirring to form a final coating, coating the surface of a base material, and naturally or forcibly drying after coating to form a stone-like texture coating. The invention provides the preparation method of the stone-like weather-resistant coating which is environment-friendly, economical and excellent in performance, the defects of the traditional coating in the aspects of texture and weather resistance are overcome, and the production cost can be reduced by utilizing the oyster shells and the recycled mica material.

Description

Technical Field

[0001] The invention relates to outdoor weather-resistant coating technology in the field of chemical industry, in particular to a method for preparing a stone-like weather-resistant coating. Background Art

[0002] As a type of decorative material specially used for exterior wall painting, imitation stone paint imitates the color, texture and feel of natural stone through special process technology. When applied on the surfaces of different materials, it can not only present the natural texture and color of stone, but also be comparable to real stone in terms of vision and touch. At the same time, compared with natural stone, it has obvious advantages in weight, weather resistance, maintenance cost, etc., which makes imitation stone paint an economical and efficient choice for exterior wall decoration. It is widely used in the exterior wall decoration of various buildings, whether it is residential, commercial buildings or public facilities, this kind of paint can enhance the beauty of their appearance.

[0003] In the current technical field, the preparation of imitation stone coatings usually requires the incorporation of stone or imitation stone components into the coating base material to achieve the imitation stone effect. Specifically, there are three types of methods: first, real stone paint, which is achieved by adding natural colored sand; second, colloid imitation stone coatings, which use water-based emulsions to prepare imitation stone gel blocks, and then use these imitation stone gel blocks to imitate stone; and finally, imitation stone coatings, which simulate stone by introducing artificial rock particles. However, these three types of stone or imitation stone components have defects, among which:

[0004] Real stone paint has the best texture and effect, but it has the defects of high viscosity and high specific gravity. It requires a stirring device with low speed and high torque, and natural sand causes serious wear and tear on the stirring equipment. In addition, natural colored sand is expensive, and there are color differences between different batches of colored sand. Colored sand is easy to settle and clump when used, which will cause the stability of the molded paint to deteriorate and the colored sand particles in the paint layer after painting to easily fade and fall off.

[0005] The gel block made of water-based emulsion is environmentally friendly, has the lowest cost, and has the best coating integrity. In addition, the corresponding gel block is customizable and can be adjusted in size, color, and texture according to needs, which has great flexibility. However, the gel block under the existing technical conditions has high requirements for the process level, and it is easy to form a clear interface between the gel color block and the coating substrate, and the gel block has a strong plastic feel, which will greatly affect the molding texture and overall appearance.

[0006] Imitation stone coatings are somewhere in between. Their advantages are that they have a certain compromise in terms of stability, cost and texture, can simulate the texture and color of natural stone to a certain extent, and have both cost and construction advantages; but their disadvantages are that the dispersion of artificial rock particles is also poor, and they are easy to form agglomerations in the coating, resulting in uneven surfaces after coating. In addition, the weather resistance of artificial rock particles in the prior art is not as good as that of natural stone, and there are still certain limitations in weather resistance and adhesion. Long-term exposure to outdoor environments is prone to fading, powdering and other problems, affecting the durability of the coating.

[0007] Therefore, developing a stone-like paint that can overcome the defects of the prior art, provide a realistic stone texture, excellent weather resistance and take cost into consideration has become an urgent problem to be solved by those skilled in the art. Summary of the invention

[0008] The technical problem solved by the present invention is to provide a method for preparing a weather-resistant coating with a stone-like texture, so as to solve the shortcomings of the above-mentioned background technology.

[0009] The technical problem solved by the present invention is achieved by adopting the following technical solutions:

[0010] A method for preparing a weather-resistant coating with a stone-like texture, using a coating base material and a stone-like component as raw materials, wherein the coating base material provides the basic properties of the coating, and the stone-like component gives the coating a stone-like texture and appearance; the preparation method specifically comprises the following steps:

[0011] S1: preparing a coating base material: mixing a water-based resin material, a dispersant, a defoamer, a mildew preventer and water, and stirring them evenly to obtain a base emulsion; then adding a film-forming aid, a thickener and a colorant, and continuing to stir until a uniform coating base material is formed, which is stored as component I;

[0012] S2: preparing the imitation stone component: using oyster shells and recycled mica as raw materials, cleaning and crushing them respectively, and then washing, drying, crushing and grinding them in sequence to obtain particles of different particle sizes;

[0013] After calcining the oyster shell pellets, the surfaces are treated with a weak acid to obtain oyster shell intermediate pellets having micropores on the surface;

[0014] The recycled mica particles are subjected to surface etching treatment using hydrofluoric acid to obtain recycled mica intermediate particles having cracks on the surface;

[0015] The treated oyster shell intermediate particles are mixed with the recycled mica intermediate particles, and the mixing mass ratio of the oyster shell intermediate particles to the recycled mica intermediate particles is controlled to be 1:2 to 1:3, and the recycled mica intermediate particles in the mixture are controlled to have a finer particle size than the oyster shell intermediate particles;

[0016] The mixed material is treated with a modified treatment liquid, wherein the modified treatment liquid is a mixture of ethyl formate, hydroxyethylethylenediamine and a titanate coupling agent; during the immersion treatment, the mixed material is first kept in an immersed state for 30 to 45 minutes, and then kept in a stirring to standing cycle treatment state, and the cycle is repeated 2 to 3 times, wherein the single stirring time is 10 to 15 minutes, and the single standing time is 15 to 30 minutes; after the cycle treatment is completed, the solid and liquid are separated, and the solid is dried to obtain modified mixed material particles;

[0017] The modified mixture particles are dry-mixed with quartz sand, nano titanium dioxide powder, and white carbon black, and after mixing evenly, industrial bone glue, ethyl carbamate, diphenylthiourea, capric acid, sodium carboxymethyl cellulose, titanate coupling agent, and an appropriate amount of water are added, and after being evenly dispersed, a stone-like texture component is obtained, which is stored as component II;

[0018] S3 On-site preparation: Mix component I and component II in a mass ratio of 1:1 to 3:2, and stir thoroughly to ensure that the two components are evenly dispersed to form the final stone-like weather-resistant coating;

[0019] S4 coating construction: Apply the prepared imitation stone weather-resistant coating evenly on the surface of the substrate to be coated by spraying, rolling or brushing. During the coating process, ensure that the coating thickness is uniform to avoid defects such as sagging and bubbles. After coating, allow the coating to dry naturally at room temperature or use an axial flow fan for forced drying. After the coating is dry, a coating with an imitation stone texture can be formed on the surface of the substrate.

[0020] As a further limitation, the water-based resin material used in the coating base material is one of acrylic resin, silicone-acrylic resin, and fluorocarbon resin.

[0021] As a further limitation, the dispersant used in the coating substrate is a polycarboxylate or a polyether, and its usage is 0.1-1% of the mass of the coating substrate; the defoamer is a silicone defoamer or a mineral oil defoamer, and its usage is 0.05-0.5% of the mass of the coating substrate; the mildewcide is an isothiazolinone mildewcide, and its usage is 0.05-0.5% of the mass of the coating substrate; the film-forming aid is ethylene glycol ethyl ether or propylene glycol methyl ether, and its usage is 1-5% of the mass of the coating substrate; the thickener is hydroxyethyl cellulose, and its usage is 0.1-1% of the mass of the coating substrate.

[0022] As a further limitation, the colorant is an environmentally friendly water-based color paste with a particle size of ≤50 μm.

[0023] As a further limitation, the recycled mica material used as raw material is a component material with a mica content ≥85% obtained by using unqualified mica paper products produced in the production stage, mica paper product scraps, and waste mica paper and mica boards recycled after use as raw materials, after alkali decomposition, washing, calcination, and screening.

[0024] As a further limitation, the particles obtained from oyster shells as raw materials retain three categories: 5-20 mesh, 20-80 mesh, and 80-200 mesh; the particles obtained from recycled mica retain three categories: 20-80 mesh, 80-200 mesh, and 200-300 mesh; through the combination of particles of different particle sizes, the layering and texture of natural stone can be simulated.

[0025] As a further limitation, the mass ratio of the titanate coupling agent to hydroxyethylethylenediamine in the modified treatment liquid is 1:1 to 1:2, and the amount of the ethyl formate is 0.5 to 0.7 times the sum of the mass of the titanate coupling agent and hydroxyethylethylenediamine.

[0026] As a further limitation, when the modified mixture particles are mixed with the quartz sand, the corresponding quartz sand particle size is 1 to 1.5 times the average particle size of the modified mixture particles; when the modified mixture particles and the quartz sand are mixed, the volume ratio of the quartz sand in the mixture of the modified mixture particles and the quartz sand is 0 to 30%;

[0027] When preparing component II, the preferred mass ratio of the raw material components is: 100 parts of a mixture of modified mixture particles and quartz sand, 20-30 parts of industrial bone glue, 5-15 parts of ethyl formate, 5-10 parts of capric acid, 1-5 parts of diphenylthiourea, 1-3 parts of sodium carboxymethyl cellulose, 0.5-2 parts of titanate coupling agent, 0.5-1.5 parts of carbon black, and 0.5-1 part of nano titanium dioxide powder.

[0028] As a further limitation, the capric acid is one or a combination of n-decanoic acid, sebacic acid, and sucrose acid.

[0029] As a further limitation, during the mixing of component I and component II in the on-site preparation stage of step S3, the viscosity of the coating is adjusted by adding water in different proportions to meet the construction requirements under different working conditions.

[0030] As a further limitation, during the mixing process of component I and component II in the on-site preparation stage of step S3, the stone-like weather-resistant coating can be enhanced in performance by adding an auxiliary agent, which is one or a combination of a leveling agent, a thixotropic agent, an anti-ultraviolet agent, and an antistatic agent.

[0031] As a further limitation, the stone-like weather-resistant coating obtained in the on-site preparation stage of step S3 needs to be applied in step S4 within 3 hours to ensure the stability and construction effect of the coating. In the actual construction process, appropriate adjustments can also be made according to the ambient temperature and humidity to ensure the film-forming effect and adhesion of the coating.

[0032] As a further limitation, during the coating construction process of step S4, the substrate to be coated is concrete, gypsum board, or wood.

[0033] As a further limitation, after the coating construction of step S4 is completed, the surface of the formed coating can be subjected to surface sealing treatment, and the sealing material of the surface sealing treatment is silicone acrylic emulsion or fluorocarbon emulsion, which is applied by spraying or rolling.

[0034] Beneficial effects: The method for preparing the stone-like weather-resistant coating of the present invention uses oyster shells and recycled mica as raw materials, which not only realizes the recycling of resources but also has a relatively low preparation cost;

[0035] The method modifies oyster shells and recycled mica materials to form an aggregate structure, which is light in weight and has better adhesion and weather resistance than natural colored sand. It can simulate the layering and texture of natural stone, thereby improving the decorative quality and stability of the stone-like weather-resistant coating, and making the coating have a more realistic appearance.

[0036] During the coating construction process, the two-component material can ensure the uniformity and adhesion of the coating by controlling the coating viscosity, thickness and drying conditions, thereby ensuring uniform coating thickness and avoiding defects such as sagging and bubbles, making the coating have excellent weather resistance, water resistance and pollution resistance;

[0037] It has better operability and adaptability during the construction process and can meet the construction requirements in different environments;

[0038] Water-based resin and environmentally friendly pigments and fillers are used. The coating is environmentally friendly during preparation and use, and is in line with the development trend of modern building decoration materials. DETAILED DESCRIPTION

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the technical solutions required to be used in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the technical contents described below are only some embodiments of the present invention. For ordinary technicians in this field, other derivative technical solutions can be obtained based on these technical contents without paying creative work, and these technical solutions also belong to the protection scope of the present invention.

[0040] The following embodiments utilize oyster shells recycled from seafood processing enterprises or seafood catering industries, and mica paper and mica board scraps and defective products recycled from mica paper processing enterprises as raw materials, which are modified and processed into imitation stone components. The imitation stone components are used as one of the components to be compounded with a coating base material to increase the imitation stone texture to the coating base material, and obtain a weather-resistant coating with the appearance and texture of natural stone that can be directly used for coating operations on the exterior walls of buildings.

[0041] First, the recovered oyster shells are cleaned, and surface impurities are removed by high-pressure water washing, and then dried. The dried oyster shells are crushed and calcined at 600°C for 1 hour. After calcination, the oyster shells are naturally cooled in the furnace and crushed and ground. Three groups of oyster shell particles with particle sizes of 5-20 mesh, 20-80 mesh, and 80-200 mesh are sieved for standby use.

[0042] While processing the oyster shell particles, the recovered mica material is subjected to alkali decomposition treatment. During the alkali decomposition operation, the recovered mica material is placed in a reactor, an appropriate amount of 10% sodium hydroxide solution is added, heated to 80°C and the reaction is maintained for 3 hours. During the reaction, a stirring device is used to break and stir the mica (if the proportion of mica board is high, it needs to be crushed before being added to the reactor).

[0043] Subsequently, the material after alkali decomposition is drained, the reactant is washed with water until neutral to remove excess alkali solution, filtered and dried, and then calcined at 800°C for 2 hours. After calcination, the material is naturally cooled with the furnace and crushed and ground, and three groups of mica material particles with particle sizes of 20-80 mesh, 80-200 mesh, and 200-300 mesh are sieved for standby use; and the mica content of the above three groups of mica material particles sieved by the above method is ≥88%.

[0044] The specific embodiments of the present invention are described in detail by the following steps:

[0045] Embodiment 1:

[0046] In Example 1, the weather-resistant coating with imitation stone texture is prepared by the following preparation method:

[0047] First prepare the coating substrate:

[0048] The preparation method of the coating substrate is similar to the preparation method of common coatings in the prior art, specifically: using water as a dispersion medium for a water-based resin material, adding a dispersant, a defoamer, and a mildew preventer, mixing them evenly to obtain a basic emulsion, then adding a film-forming aid, a thickener, and a colorant to the basic emulsion, and continuing to stir until a uniform coating substrate is formed.

[0049] The water-based resin material used in the coating substrate is one of acrylic resin, silicone-acrylic resin and fluorocarbon resin, and the dosage is 25-35% of the coating substrate mass; the dispersant used is polycarboxylate or polyether, and the dosage is 0.1-1% of the coating substrate mass; the defoamer used is silicone defoamer or mineral oil defoamer, and the dosage is 0.05-0.5% of the coating substrate mass; the mildewproof agent used is isothiazolinone mildewproof agent, and the dosage is 0.05-0.5% of the coating substrate mass; the film-forming aid used is ethylene glycol ethyl ether or propylene glycol methyl ether, and the dosage is 1-5% of the coating substrate mass; the thickener used is hydroxyethyl cellulose, and the dosage is 0.1-1% of the coating substrate mass; and the corresponding colorant used is an environmentally friendly water-based color paste with a particle size of ≤50μm, and the dosage is 0.5-5% of the coating substrate mass.

[0050] Specifically in this embodiment, the water-based resin material used in the coating substrate is silicone acrylic resin, and the amount used is 30% of the mass of the coating substrate; the dispersant is a polycarboxylate dispersant, and the amount used is 0.5% of the mass of the coating substrate; the defoamer is a silicone defoamer, and the amount used is 0.2% of the mass of the coating substrate; the mildew inhibitor is an isothiazolinone mildew inhibitor, and the amount used is 0.3% of the mass of the coating substrate; the film-forming aid is ethylene glycol ethyl ether, and the amount used is 3% of the mass of the coating substrate; the thickener is hydroxyethyl cellulose, and the amount used is 0.5% of the mass of the coating substrate; the colorant is an environmentally friendly water-based color paste, and the amount used is 2% of the mass of the coating substrate.

[0051] Then prepare the stone-like texture component:

[0052] The oyster shell particles and mica particles obtained by the above steps are treated with acid respectively:

[0053] The oyster shell intermediate particles are placed in a reactor, an appropriate amount of hydrochloric acid solution with a mass concentration of 5% is added, and the mixture is heated to 60°C and kept reacting for 15 minutes. During the reaction, a stirring device is used to continuously stir the oyster shell intermediate particles so that the oyster shell intermediate particles are kept in an oscillating suspension state in the hydrochloric acid solution to promote the uniformity of the reaction. After the acid treatment is completed, the material is filtered, washed with water until neutral, and then dried to obtain oyster shell intermediate particles with micropores on the surface.

[0054] The surface of the mica intermediate particles is treated with hydrofluoric acid. During the treatment, the mica intermediate particles are placed in a reactor, and a proper amount of 5% hydrofluoric acid solution is added. The mixture is heated to 50°C and kept reacting for 30 minutes. During the reaction, a stirring device is also used for stirring. After the acid etching treatment is completed, the material is filtered, washed with water until neutral, and dried to obtain recycled mica intermediate particles with cracks on the surface.

[0055] The acid-treated oyster shell particles and mica particles are mixed in a mass ratio of 1:2 to 1:3 to form a stone-like component. The ratio can be adjusted according to the actual stone effect required. The combination of particles of different particle sizes can simulate the layering and texture of natural stone (for example, if a rough texture is required on the surface of the substrate, the proportion of large-size particles can be increased; if a delicate texture is required, the proportion of fine-size particles can be increased).

[0056] Oyster shell particles and mica particles can be pre-prepared or configured at the construction site; however, it should be noted that the three groups of large, medium and fine oyster shell particles correspond to large, medium and fine mica particles (i.e., large-size oyster shell particles of 5 to 20 mesh and large-size mica particles of 20 to 80 mesh are added and mixed in a mass ratio of 1:2 to 1:3, and the same applies to medium-size particles and small-size particles). Specifically in this embodiment, the mass ratio of oyster shell particles and mica particles is 1:2, and the ratio of large, medium and fine particles is 1:1:3, in order to obtain a delicate imitation stone texture on the surface of the substrate after subsequent modification.

[0057] Then the mixed pellets are treated with a modified treatment liquid, wherein the corresponding modified treatment liquid is prepared by titanate coupling agent, hydroxyethylethylenediamine, ethyl carbamate and the rest of water, wherein the mass ratio of titanate coupling agent and hydroxyethylethylenediamine in the modified treatment liquid is 1:1 to 1:2, and the amount of ethyl carbamate is 0.5 to 0.7 times the mass sum of titanate coupling agent and hydroxyethylethylenediamine. Specifically in this embodiment, the ratio of the modified treatment liquid includes 6% of the total mass of titanate coupling agent, 6% of the total mass of hydroxyethylethylenediamine, 6% of the total mass of ethyl carbamate and the rest of water.

[0058] The preparation method of the modified treatment liquid is as follows: first, the titanate coupling agent and hydroxyethylethylenediamine are mixed evenly, then ethyl carbamate and an appropriate amount of water are added and stirred until completely dissolved, and finally the remaining amount of water is added and mixed evenly. When the modified treatment liquid is used to modify the mixed particles, the mixed particles are first immersed in the modified treatment liquid for 35 minutes, then stirred for 10 minutes with a stirrer, and then left to stand for 20 minutes, and then stirred for 10 minutes and left to stand for 20 minutes twice in a cycle. After the treatment is completed, the solid and liquid are separated, and the solid is dried with hot air at a temperature of 80°C. After drying, the agglomerated blocks are crushed to ensure that the particle size meets the requirements of the coating substrate, and the modified mixture particles are obtained.

[0059] The modified mixture particles are dry-mixed with auxiliary materials and fillers, wherein the auxiliary materials are quartz sand, and the fillers are nano titanium dioxide powder and white carbon black, wherein the particle size of the quartz sand as an auxiliary material is 1 to 1.5 times the average particle size of the modified mixture particles; the quartz sand is used to form a composite particle material with a natural stone texture together with the modified mixture particles. However, since the density of the modified mixture particles is smaller than that of the modified mixture particles, considering the uniformity and stability of the coating finally formed by the coating, the modified mixture particles and the quartz sand are compounded in a volume ratio when mixed.

[0060] During the dry mixing process, the modified mixture particles, quartz sand, nano titanium dioxide powder and white carbon black are first pre-mixed according to their respective usage ratios, and then fully stirred using a high-speed mixer to ensure that the components are evenly mixed. After stirring, the mixture is sieved to remove possible large particles or lumps to ensure the uniformity of the mixture. After mixing evenly, softened industrial glue, ethyl formate, diphenylthiourea, capric acid, sodium carboxymethyl cellulose, titanate coupling agent and an appropriate amount of water are added, and component II is obtained after being evenly dispersed at a temperature of 80°C, which is the stone-like texture component.

[0061] Preferably, the mass proportions of the raw materials for the aforementioned imitation stone texture are: 100 parts of a mixture of modified mixture particles and quartz sand (the volume proportion of quartz sand as an auxiliary material in the mixture of modified mixture particles and quartz sand is 0-30%. If the volume proportion is too much, the defects of high viscosity, high specific gravity and easy falling off of quartz sand particles existing in real stone paint will easily appear), 20-30 parts of industrial bone glue, 5-15 parts of ethyl formate, 5-10 parts of capric acid, 1-5 parts of diphenylthiourea, 1-3 parts of sodium carboxymethyl cellulose, 0.5-2 parts of titanate coupling agent, 0.5-1.5 parts of carbon black and 0.5-1 part of nano titanium dioxide powder.

[0062] Specifically in Example 1, the mass fractions of the raw materials for the aforementioned imitation stone texture are: 100 parts of a mixture of modified mixture particles and quartz sand, 25 parts of industrial bone glue, 10 parts of ethyl formate, 7 parts of n-decanoic acid, 3 parts of diphenylthiourea, 2 parts of sodium carboxymethyl cellulose, 1 part of titanate coupling agent, 1 part of carbon black, and 0.7 parts of nano titanium dioxide powder, and component II is prepared under the conditions of the above mass fractions of raw materials.

[0063] In this embodiment, the improvement of component II is the main improvement over the prior art. By using recycled oyster shells and recycled mica as raw materials to prepare a stone-like texture component, on the one hand, the production cost can be effectively reduced while reducing environmental pollution; on the other hand, the material properties of oyster shells and mica can be utilized to give the coating a natural luster and a texture close to that of natural stone, thereby improving its decorative effect.

[0064] However, oyster shell fragments and recycled mica materials themselves have defects in polarity and poor bonding performance. Larger oyster shell fragments and mica materials in the paint can easily cause coating unevenness and reduced adhesion. In addition, stress defects will be generated in the interface area with the paint, resulting in reduced durability of the coating. In addition, the formed imitation stone particles will produce interface peeling between the paint and the coating after a period of molding, which will cause the imitation stone particles to fall off, forming potholes on the coating surface, affecting the overall appearance and service life, while easily causing local defects, resulting in poor weather resistance.

[0065] In order to solve these problems, this embodiment performs a series of pre-treatment operations on the oyster shell fragments and the recycled mica fragments, and after the pre-treatment operations, the oyster shell fragments and the mica material are modified by introducing a modified treatment liquid, so that polar bonding occurs between the oyster shell fragments and the recycled mica fragments to form a stable granular material, and the compatibility and bonding performance of the stable granular material with the coating are improved.

[0066] Specifically, the titanate coupling agent in the modified treatment liquid can react with the active groups on the surface of the oyster shell fragments and the recycled mica fragments to form a stable chemical bond, thereby improving the surface bonding force; hydroxyethylethylenediamine can reduce the surface tension of the granular material and give polarity to the surface of the recycled mica fragments after pickling, so that the recycled mica fragments with smaller particle size are aggregated on the surface of the oyster shell fragments. In addition, hydroxyethylethylenediamine, as a surfactant, can improve the wettability of the material surface, making it easier for the modified treatment liquid and other components in component II to penetrate into the acid-treated oyster shell fragments and the recycled mica fragments, thereby improving the performance of the oyster shell fragments and the recycled mica fragments; the role of ethyl formate in the technical scheme of this embodiment is similar to that of a cross-linking agent, which improves the bonding strength of the recycled mica fragments after aggregation on the surface of the oyster shell fragments to form a modified mixture of external recycled mica fragments and oyster shell fragments, and at the same time, it can also avoid the delamination and peeling of the modified mixture particles on the coating after the coating is formed to a certain extent.

[0067] Since the modified mixture particles are an oyster shell fragment core structure wrapped with recycled mica fragments, the particle size of the modified mixture particles is larger than that of the oyster shell fragments. The mica fragments can provide gloss and stone visual texture, and the oyster shell fragments can be used to reduce the density and provide a structural core. Therefore, they can be mixed with quartz sand to prepare a composite granular material with a natural stone texture and reduce the structural density of the stone-like texture component.

[0068] In addition, due to the addition and use of ethyl formate, the surface polarity of the modified mixture particles after nucleation can also be improved, making it more compatible with the coating substrate than natural stone components such as quartz sand, thereby improving the uniformity and adhesion of the stone-like texture components in the coating.

[0069] The technical solution of this embodiment also adds nano titanium dioxide powder and white carbon black as fillers in the process of preparing component II; during the previous operation, the intermediate particles of oyster shells are treated with weak acid to obtain intermediate particles of oyster shells with micropores on the surface; and the intermediate particles of mica are etched with hydrofluoric acid to obtain intermediate particles of recycled mica with surface microcracks on the surface; the surface micropores of the intermediate particles of oyster shells and the surface microcracks of the intermediate particles of recycled mica can adsorb and fix the nano titanium dioxide powder and white carbon black as fillers, thereby improving the stability and durability of the coating. Nano titanium dioxide powder has excellent hiding power and weather resistance, can improve the UV resistance of the coating, and extend the service life of the coating. White carbon black has good dispersibility and adsorption, which can improve the adhesion and anti-pollution ability of the coating.

[0070] The unabsorbed nano titanium dioxide powder and white carbon black are used to improve the weather resistance and wear resistance of the coating after coating formation, and also give the coating excellent self-cleaning function.

[0071] In the process of preparing component II, in addition to the above raw materials, industrial bone glue, ethyl carbamate, capric acid, diphenylthiourea and sodium carboxymethyl cellulose are also added.

[0072] Among them, industrial bone glue, as a natural polymer material, can provide good bonding properties. Compared with traditional synthetic polymer adhesives, it has better bonding with the acid-treated oyster shell surface, can fill the gaps between the middle particles of oyster shells in the modified mixture particles, and form an adhesive film layer on the outer surface, further improving the adhesion between the modified mixture particles and the coating substrate, thereby optimizing the crack resistance of the coating after molding.

[0073] Urethane acts as a crosslinker to further increase the crosslinking density of the coating, thereby improving the mechanical strength and chemical resistance of the coating.

[0074] As an organic acid, capric acid is used in this embodiment to adjust the pH value of component II on the one hand, and on the other hand, it can inhibit the surfactant performance of hydroxyethylethylenediamine, so that component II has storage stability when stored alone; when component II is mixed with component I, the effect of capric acid is weakened, thereby activating the role of hydroxyethylethylenediamine as a surfactant, which can reduce the surface tension of the particles and improve its wettability in the coating, so that the nucleated modified mixture particles are easier to be evenly dispersed in the coating.

[0075] The role of diphenylthiourea is that, as a highly effective antimicrobial agent, it can effectively inhibit the growth and reproduction of microorganisms such as bacteria and fungi, thereby extending the service life of the coating and maintaining its aesthetics.

[0076] As a thickener, sodium carboxymethyl cellulose can increase the viscosity of the coating, making the coating have better leveling and coating performance during the construction process. At the same time, sodium carboxymethyl cellulose can also improve the storage stability of component II and prevent the coating from settling or stratifying during storage.

[0077] After component I and component II are prepared, they can be packaged independently. The two-component packaging structure can ensure the stability of the coating and extend its shelf life to avoid chemical reactions during storage and transportation, thereby maintaining the stability of its components (mainly component II).

[0078] When components I and II are used, they are mixed on site in a certain proportion to ensure that the performance of the coating is optimal. The mixing ratio of components I and II can be adjusted according to actual application requirements. Usually, the mass ratio of component I to component II is 1:1 to 1:3, and the specific ratio depends on the final use of the coating and the required performance. For example, if the adhesion and durability of the coating need to be improved, the proportion of component I can be appropriately increased; if the decorative effect and texture of the coating need to be improved, the proportion of component II can be appropriately increased.

[0079] During the on-site preparation stage of the present embodiment, component I and component II are mixed in a mass ratio of 1:1. During mixing, a proper amount of water is first added to component I to adjust the viscosity to adapt to different construction conditions, and then the imitation stone component is slowly added to the coating substrate while being stirred at high speed; sufficient stirring is performed to ensure that the two components are evenly dispersed, so as to ensure that the coating substrate can evenly wrap the imitation stone component, thereby obtaining an imitation stone weather-resistant coating with the appearance and texture of natural stone.

[0080] The above-mentioned stone-like weather-resistant paint can be used for coating operations on the exterior walls of buildings with a flat, clean and oil-free surface. The construction method can be conventional methods such as spraying, rolling or brushing. After the coating is completed, let the coating dry naturally at room temperature or use an axial flow fan for forced drying. After the paint is dry, a coating with a stone-like texture can be formed on the surface of the substrate.

[0081] The weather-resistant coating prepared by the above steps has a good imitation stone texture, can simulate the appearance and texture of natural stone, and has excellent weather resistance and durability. The coating is suitable for coating operations on the exterior walls of buildings, which can not only improve the beauty of the buildings, but also has the advantages of environmental protection and economy.

[0082] Embodiment 2:

[0083] In Example 2, the weather-resistant coating with imitation stone texture is prepared by the following preparation method:

[0084] First prepare the coating substrate:

[0085] In this embodiment, the water-based resin material used in the coating substrate is acrylic resin, and its dosage is 35% of the coating substrate mass. The dispersant is selected from polycarboxylates, and the dosage is 0.5% of the coating substrate mass. The defoamer is selected from silicone defoamers, and the dosage is 0.3% of the coating substrate mass. The mildew inhibitor is selected from isothiazolinones, and the dosage is 0.2% of the coating substrate mass. The film-forming aid is selected from propylene glycol methyl ether, and the dosage is 4% of the coating substrate mass. The thickener is selected from hydroxyethyl cellulose, and the dosage is 0.8% of the coating substrate mass. The colorant is selected from environmentally friendly water-based color paste with a particle size of ≤50μm, and the dosage is 1% of the coating substrate mass.

[0086] In the process of preparing the coating substrate, the acrylic resin is first mixed with water, stirred evenly, and then the dispersant is added to ensure the uniform dispersion of the pigment and filler. Subsequently, the defoamer, mildew inhibitor, film-forming aid and thickener are added in sequence and stirred thoroughly to form a stable coating substrate. Finally, the colorant is added and adjusted to the desired color and stirred evenly again to ensure the uniform distribution of the color.

[0087] Then prepare the stone-like texture component:

[0088] The oyster shell particles and mica particles obtained by the above steps are treated with acid respectively:

[0089] During the acid treatment, the oyster shell intermediate particles are treated with a hydrochloric acid solution with a mass concentration of 4%, heated to 55°C and kept reacting for 20 minutes, and stirred continuously during the reaction. After the acid treatment is completed, the particles are filtered, washed with water until neutral, and then dried to obtain oyster shell intermediate particles with micropores on the surface.

[0090] The mica intermediate particles are treated with a 6% hydrofluoric acid solution, heated to 55°C and kept reacting for 30 minutes, and stirred with a stirring device during the reaction. After the acid treatment, the particles are filtered, washed with water until neutral, and then dried to obtain recycled mica intermediate particles with cracks on the surface.

[0091] The pickled oyster shell particles and mica particles are mixed in a mass ratio of 1:3, and the ratio of large, medium and fine particles is 3:2:1, in order to obtain a rough substrate surface with a stone-like touch after subsequent modification.

[0092] A modified treatment liquid is prepared, wherein the modified treatment liquid comprises 3% by weight of a titanate coupling agent, 5% by weight of hydroxyethylethylenediamine, 4% by weight of ethyl carbamate and the remainder of water.

[0093] When the modified particles are modified by the modified treatment liquid, the mixed particles are first immersed in the modified treatment liquid for 40 minutes, then stirred for 15 minutes by a stirrer, and then allowed to stand for 15 minutes, and then stirred for 15 minutes and allowed to stand for 15 minutes twice in a cycle. After the treatment is completed, the solid and liquid are separated, and the solid is dried with hot air at 65°C. After drying, the agglomerated blocks are crushed to ensure that their particle size meets the requirements of the coating substrate, thereby obtaining modified mixture particles.

[0094] 100 parts by mass of modified mixture particles are pre-mixed with 0.8 parts by mass of nano titanium dioxide powder and 1 part by mass of white carbon black. After mixing evenly, 30 parts by mass of softened industrial glue, 8 parts by mass of ethyl formate, 3 parts by mass of diphenylthiourea, 5 parts by mass of sebacic acid, 2 parts by mass of sodium carboxymethyl cellulose, 0.8 parts by mass of titanate coupling agent and an appropriate amount of water are added. After being evenly dispersed at a temperature of 80°C, component II is obtained, which is the stone-like texture component.

[0095] During the on-site preparation stage, component I and component II are mixed in a volume ratio of 3:2 and stirred thoroughly to ensure that the two components are evenly dispersed to obtain a stone-like weather-resistant coating with the appearance and texture of natural stone.

[0096] The finished coating prepared under the conditions of this embodiment 2 can also be directly applied to the exterior wall surface of the building, and the application method is the same as the application method of embodiment 1. The formed exterior wall coating has a stone-like texture with alternating stone and transparent textures, and has better weather resistance, water repellency and crack resistance under outdoor conditions.

[0097] The weather-resistant coating prepared by the steps of Example 1 and Example 2 not only has the appearance and texture of natural stone, but also has excellent weather resistance and durability, and can meet the needs of modern building exterior wall decoration. In addition, the preparation process of the coating makes full use of waste resources, which conforms to the concepts of environmental protection and sustainable development. In addition, since the modified mixture particles are used as the stone-like texture component / part as the stone-like texture component, the specific gravity and cost of the coating can be effectively reduced, thereby having high economic efficiency.

[0098] Embodiment three:

[0099] In Example 3, the formula of the stone-like weather-resistant coating is further optimized to improve its environmental performance and construction convenience. In this example, the preparation method of the coating substrate is similar to that of Example 2, but the dispersant and thickener are adjusted to improve the stability and construction performance of the coating.

[0100] In the coating base material, the dispersant is a compound of polycarboxylates and polyethers, with the dosage of 0.3% and 0.2% of the coating base material mass, respectively. The thickener is a compound of hydroxyethyl cellulose and alkali-swellable acrylic copolymer, with the dosage of 0.6% and 0.4% of the coating base material mass, respectively. Through this compounding method, the coating has better stability during storage and construction, avoiding stratification and precipitation caused by temperature changes or long-term standing.

[0101] In the preparation of the stone-like texture component, Example 3 further optimized the acid treatment step to improve the surface activity of the oyster shell particles and the mica particles. Specifically, the oyster shell particles were treated with a hydrochloric acid solution with a mass concentration of 3%, the reaction temperature was increased to 60°C, and the reaction time was shortened to 15 minutes. The mica particles were treated with a hydrofluoric acid solution with a concentration of 5%, the reaction temperature was maintained at 55°C, and the reaction time was shortened to 25 minutes. By shortening the reaction time and appropriately adjusting the acid concentration, the acid treatment effect is ensured and the impact of the acid on the environment is reduced.

[0102] In the formula of the modified treatment liquid, Example 3 adds 2% of the total mass of silane coupling agent to further improve the compatibility and adhesion of the modified mixture particles with the coating substrate. During the preparation of the modified treatment liquid, the modified mixture particles are first mixed evenly with the silane coupling agent, and then other modifiers and water are added to ensure that the modifier can fully penetrate into the surface of the material particles, thereby improving the overall performance of the coating.

[0103] In the final coating preparation stage, Example 3 fine-tuned the mixing ratio of component I and component II, using a volume ratio of 2:3 to obtain a more delicate and uniform stone-like texture coating. In addition, Example 3 also introduced 1% of the total mass of nano-scale silica as a filler to improve the anti-fouling and wear resistance of the coating.

[0104] Through the optimization of Example 3, the prepared weather-resistant coating not only has a more realistic imitation stone texture, but also has significantly improved environmental performance and construction convenience. The storage stability, construction fluency and durability of the coating have all been improved, making it more suitable for the decoration needs of modern building exterior walls. In addition, the environmental performance of the coating has been further improved, which is in line with the current construction industry's pursuit of green and environmentally friendly materials.

[0105] In order to further verify the performance of the coating of the aforementioned embodiment, a series of performance tests were conducted, including weather resistance, abrasion resistance, impact resistance, adhesion, etc. The test results show that the performance parameters of the coating are as follows:

[0106] Weather resistance: After the coating is formed, it is exposed to ultraviolet light for a long time, and subjected to temperature and humidity cycles and natural weather tests under outdoor conditions (from May to March of the following year in Hengyang, Hunan, Changsha, Hunan, and Jingzhou, Hubei). There is no obvious fading, powdering or cracking on the surface of the coating, which shows excellent weather resistance.

[0107] Wear resistance: After 5,000 friction tests, only slight wear marks appeared on the coating surface, proving that it has good wear resistance.

[0108] Impact resistance: After local testing of continuous heavy impact, the coating showed no cracking or falling off, and the shedding rate of the stone-like particles contained in the coating was less than 3%, showing high impact resistance.

[0109] Adhesion: After the cross-cut test, the adhesion between the coating and the substrate reached the first-class standard, indicating that it has good adhesion.

[0110] It has met the design requirements in all aspects of performance, has excellent weather resistance and wear resistance, and can meet the needs of outdoor use environments.

[0111] The imitation stone texture weather-resistant coating (embodiment one, embodiment two, embodiment three) of the technical solution of the present invention has a better adhesion effect when coating substrates with a certain roughness on the surface of concrete, gypsum board, wood, etc., and the coating shows good leveling and adhesion, and can ensure that the coating is uniform and has no obvious defects. After molding, the coating surface presents the texture and layering of natural stone. However, the coating effect for glass, smooth metal surfaces, etc. is poor, therefore, it is necessary to carry out appropriate pretreatment of these surfaces before construction, such as polishing or using primer, to improve the adhesion of the coating. In addition, a small amount can also be prepared before the coating operation on the substrate surface, and a coating test is carried out on the substrate surface to be coated to evaluate its imitation stone texture effect.

[0112] In practical applications, the construction environment of imitation stone weather-resistant coatings also needs attention. It is recommended to carry out coating operations under conditions of temperature between 5°C and 35°C and relative humidity below 85%. In addition, before construction, the substrate surface should be clean, dry, free of oil and dust to ensure the adhesion and overall effect of the coating.

[0113] In order to further improve the surface performance of the coating, in another embodiment, the surface of the formed coating can be treated with a surface sealant of silicone acrylic emulsion by spraying to enhance the weather resistance, pollution resistance and outer surface texture of the coating.

[0114] In addition, it should be noted that the stone-like weather-resistant coating obtained during the on-site preparation stage needs to be applied within 3 hours to ensure the stability and construction effect of the coating. In the actual construction process, appropriate adjustments can also be made according to the ambient temperature and humidity to ensure the film-forming effect and adhesion of the coating.

[0115] In another embodiment, in order to further improve the performance of the coating, some functional additives can be added to the formula to enhance the corresponding performance of the stone-like weather-resistant coating. The corresponding functional additives are one or a combination of leveling agents, thixotropic agents, UV protection agents, and antistatic agents. The dosage can be adjusted with reference to the technical specifications of the corresponding products. For example, adding a leveling agent can improve the leveling of the coating and reduce brush marks and orange peel phenomena during painting; adding a thixotropic agent can improve the storage stability of the coating and prevent the coating from settling during storage; adding a UV protection agent can further improve the weather resistance of the coating and extend the service life of the coating; and the addition of an antistatic agent helps to reduce the accumulation of static electricity on the surface of the coating, reduce dust adsorption, and maintain the cleanliness of the coating.

[0116] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for preparing a stone-like weather-resistant coating, characterized in that: The specific steps include: S1: preparing a coating base material: mixing a water-based resin material, a dispersant, a defoamer, a mildew preventer and water, and stirring them evenly to obtain a base emulsion; then adding a film-forming aid, a thickener and a colorant, and continuing to stir until a uniform coating base material is formed, which is stored as component I; S2: preparing the imitation stone component: using oyster shells and recycled mica as raw materials, cleaning and crushing them respectively, and then washing, drying, crushing and grinding them in sequence to obtain particles of different particle sizes; After calcining the oyster shell pellets, the surfaces are treated with a weak acid to obtain oyster shell intermediate pellets having micropores on the surface; The recycled mica particles are subjected to surface etching treatment using hydrofluoric acid to obtain recycled mica intermediate particles having cracks on the surface; The treated oyster shell intermediate particles are mixed with the recycled mica intermediate particles, and the mixing mass ratio of the oyster shell intermediate particles to the recycled mica intermediate particles is controlled to be 1:2 to 1:3, and the recycled mica intermediate particles in the mixture are controlled to have a finer particle size than the oyster shell intermediate particles; The mixed material is treated with a modified treatment liquid, wherein the modified treatment liquid is a mixture of ethyl formate, hydroxyethylethylenediamine and a titanate coupling agent; during the immersion treatment, the mixed material is first kept in an immersed state for 30 to 45 minutes, and then kept in a stirring to standing cycle treatment state, and the cycle is repeated 2 to 3 times, wherein the single stirring time is 10 to 15 minutes, and the single standing time is 15 to 30 minutes; after the cycle treatment is completed, the solid and liquid are separated, and the solid is dried to obtain modified mixed material particles; The modified mixture particles are dry-mixed with quartz sand, nano titanium dioxide powder, and white carbon black, and after mixing evenly, industrial bone glue, ethyl carbamate, diphenylthiourea, capric acid, sodium carboxymethyl cellulose, titanate coupling agent, and an appropriate amount of water are added, and after being evenly dispersed, a stone-like texture component is obtained, which is stored as component II; S3 On-site preparation: Mix component I and component II in a mass ratio of 1:1 to 3:2, and stir thoroughly to ensure that the two components are evenly dispersed to form the final stone-like weather-resistant coating; S4 coating construction: Apply the prepared imitation stone weather-resistant coating evenly on the surface of the substrate to be coated by spraying, rolling or brushing. During the coating process, ensure that the coating thickness is uniform to avoid defects such as sagging and bubbles. After coating, allow the coating to dry naturally at room temperature or use an axial flow fan for forced drying. After the coating is dry, a coating with an imitation stone texture can be formed on the surface of the substrate.

2. The method for preparing the stone-like weather-resistant coating according to claim 1, characterized in that: The water-based resin material used in the coating base material is one of acrylic resin, silicone-acrylic resin and fluorocarbon resin.

3. The method for preparing the stone-like weather-resistant coating according to claim 1, characterized in that: The dispersant used in the coating substrate is a polycarboxylate or a polyether, and its usage is 0.1-1% of the mass of the coating substrate; the defoamer is a silicone defoamer or a mineral oil defoamer, and its usage is 0.05-0.5% of the mass of the coating substrate; the mildewcide is an isothiazolinone mildewcide, and its usage is 0.05-0.5% of the mass of the coating substrate; the film-forming aid is ethylene glycol ethyl ether or propylene glycol methyl ether, and its usage is 1-5% of the mass of the coating substrate; the thickener is hydroxyethyl cellulose, and its usage is 0.1-1% of the mass of the coating substrate.

4. The method for preparing the stone-like weather-resistant coating according to claim 1, characterized in that: The colorant is an environmentally friendly water-based color paste with a particle size of ≤50 μm.

5. The method for preparing the stone-like weather-resistant coating according to claim 1, characterized in that: The recycled mica material used as raw material is a component material with a mica content of ≥85% obtained by alkali decomposition, washing, calcination and screening, using unqualified mica paper products produced in the production stage, mica paper product scraps, and waste mica paper and mica boards recycled after use as raw materials.

6. The method for preparing the stone-like weather-resistant coating according to claim 1, characterized in that: The particles obtained from the oyster shells used as raw materials are classified into three categories: 5-20 mesh, 20-80 mesh, and 80-200 mesh; the particles obtained from the recycled mica materials are classified into three categories: 20-80 mesh, 80-200 mesh, and 200-300 mesh.

7. The method for preparing the stone-like weather-resistant coating according to claim 1, characterized in that: The mass ratio of the titanate coupling agent to hydroxyethylethylenediamine in the modified treatment liquid is 1:1 to 1:2, and the amount of the ethyl formate is 0.5 to 0.7 times the sum of the mass of the titanate coupling agent and hydroxyethylethylenediamine.

8. The method for preparing the stone-like weather-resistant coating according to claim 1, characterized in that: When the modified mixture particles are mixed with the quartz sand, the corresponding quartz sand particle size is 1 to 1.5 times the average particle size of the modified mixture particles; when the modified mixture particles and the quartz sand are mixed, they are compounded in a volume ratio, and the volume proportion of the quartz sand in the mixture of the modified mixture particles and the quartz sand is 0 to 30%; When preparing component II, the specific mass ratio of the raw material components is: 100 parts of a mixture of modified mixture particles and quartz sand, 20-30 parts of industrial bone glue, 5-15 parts of ethyl formate, 5-10 parts of capric acid, 1-5 parts of diphenylthiourea, 1-3 parts of sodium carboxymethyl cellulose, 0.5-2 parts of titanate coupling agent, 0.5-1.5 parts of carbon black, and 0.5-1 part of nano titanium dioxide powder.

9. The method for preparing the stone-like weather-resistant coating according to claim 1, characterized in that: The capric acid is one or a combination of n-decanoic acid, sebacic acid and sucrose acid.

10. The method for preparing the stone-like weather-resistant coating according to claim 1, characterized in that: After the coating construction in step S4 is completed, a surface sealing treatment is performed on the surface of the formed coating. The sealing material of the surface sealing treatment is a silicone acrylic emulsion or a fluorocarbon emulsion, and the construction is performed by spraying or rolling.