Natural colored sand wall-like building coating, preparation method thereof and evaluation method for color matching difficulty

Abstract

The present application relates to the technical field of building coating, and provides a colored sand wall-like building coating, a preparation method thereof and an evaluation method of color matching difficulty, wherein the colored sand wall-like building coating comprises an acrylic polymer emulsion, hydroxyethyl cellulose, modified bentonite, natural colored sand, transparent color paste, an additive and water. The coating provided by the present application uses the acrylic polymer emulsion as a film-forming resin, completely wets the natural colored sand and fully disperses the natural colored sand in the whole coating system, so that the emulsion paint is more permeable, and the method of synergistic color matching of the natural colored sand and the transparent color paste is used, so that the color change of the product during the drying process of the coating after construction is small, the film-forming is not required to be completely dry, the color difference comparison and color adjustment can be performed with the standard color in the wet film state, the color matching time is shortened, and the production efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of architectural coatings, in particular to a colored sand wall-like architectural coating, a preparation method thereof and an evaluation method for color matching difficulty. BACKGROUND

[0002] The synthetic resin emulsion sand wall-like architectural coating has the advantages of rich color and adaptability to different modeling construction on site, and after coating, the whole is uniform and crack-free, and can present a decorative effect of dignified and elegant texture, becoming an important architectural coating.

[0003] Since such products have rich colors, the color matching process is a key process in the production process. The existing technology mostly uses inorganic or organic color paste for color matching. Since the color difference caused by different batches of color paste is controllable and the color types are rich, the coating production efficiency is high, but the weather resistance of the product after coating is poor, and it is easy to fade, which is not suitable for wide application and promotion. In order to solve the problem of poor weather resistance of color paste color matching, natural colored sand can be used for color matching.

[0004] However, there is a color difference between batches of natural colored sand. The film-forming material of the sand wall-like architectural coating product is a synthetic resin emulsion. The synthetic resin sand wall-like architectural coating coating layer prepared by different batches of colored sand and different emulsions presents different colors. The synthetic resin sand wall-like architectural coating coating layer prepared by the same colored sand and different emulsions on the market also presents different colors. The synthetic resin sand wall-like architectural coating prepared by the same colored sand and the same emulsion on the market presents different colors under different drying conditions, resulting in the need for multiple color adjustments during the coating production process of the natural colored sand sand wall-like architectural coating product. The coating production enterprises often solve the above problems by specifying the emulsion type and setting the drying conditions. However, since the emulsion is greatly affected by temperature and humidity during the drying process of the coating, the transparency of the wet film and the dry film is inconsistent, resulting in a large color difference between the wet film and the dry film of the colored sand sand wall-like architectural coating. Therefore, the final paint film color cannot be determined until the paint film is completely dried, and whether and how to adjust the color can be determined only after comparing the final paint film color with the standard color, which reduces the production efficiency. SUMMARY

[0005] Therefore, the present application provides a colored sand wall-like architectural coating, a preparation method thereof and an evaluation method for color matching difficulty. The colored sand wall-like architectural coating provided by the present application does not have obvious color difference during the drying process, is easy to color match during the production process, and is beneficial to improve the production efficiency.

[0006] In order to achieve the above-mentioned application purposes, the present application provides the following technical solutions:

[0007] A colored sand wall-like architectural coating comprises the following components in mass percentage:

[0008]

[0009] The solid content of the acrylic polymer emulsion is ≥ 41wt%.

[0010] Preferably, the viscosity of the acrylic polymer emulsion is 1500-4500 mPa·s, and the pH value of the acrylic polymer emulsion is 7.5-8.5.

[0011] Preferably, the transparent color paste is a water-based transparent iron oxide color paste.

[0012] Preferably, the auxiliary agent includes the following components in percentage of mass content of the colored sand sand wall building coating:

[0013]

[0014] The application also provides a preparation method of the colored sand sand wall building coating, comprising the following steps:

[0015] Mixing the acrylic polymer emulsion, the hydroxyethyl cellulose, the auxiliary agent, the modified bentonite, the natural colored sand, the color paste and the water to obtain the colored sand sand wall building coating.

[0016] Preferably, the auxiliary agent includes a pH regulator, a defoaming agent, an antifreezing agent, a film-forming auxiliary agent, a preservative and mildew-proof agent, a thickening agent and a slow-drying agent, and the mixing includes the following steps:

[0017] Firstly mixing the hydroxyethyl cellulose, the water, the pH regulator and the defoaming agent to obtain a dissolving solution, wherein the water is added in an amount of 50%-80% of the total mass of the water, the pH regulator is added in an amount of 30-50% of the total mass of the pH regulator, and the defoaming agent is added in an amount of 30-50% of the total mass of the defoaming agent;

[0018] Secondly mixing the dissolving solution, the remaining pH regulator, the preservative and mildew-proof agent, the acrylic polymer emulsion, the film-forming auxiliary agent, the antifreezing agent, the thickening agent, the slow-drying agent and the remaining water to obtain a slurry;

[0019] Thirdly mixing the slurry, the natural colored sand, the transparent color paste, the modified bentonite and the remaining defoaming agent to obtain the colored sand sand wall building coating.

[0020] Preferably, the first mixing is performed by stirring at a rate of 1200-1500 revolutions per minute for 15-20 minutes.

[0021] Preferably, the second mixing is performed by stirring at a rate of 800-1100 revolutions per minute for 5-15 minutes.

[0022] Preferably, the third mixing method is stirring, the stirring rate is 500-700 rpm, and the stirring time is 5-15 minutes.

[0023] The application further provides an evaluation method for the color mixing difficulty of a colored sand wall-like building coating, which comprises the following steps: applying the coating on the surfaces of three different types of standard plates respectively; the types of the standard plates include non-asbestos fiber cement flat plates, snow board and PV plastic plates; at least one standard plate is applied for each type;

[0024] At the end of the application, the color space data of the initial state of the coating on the surface of each standard plate is measured by using a color difference meter, and the color space data includes L value, a value and b value;

[0025] Then, the color space data of the coating on the surface of each standard plate is measured every 30 minutes, the difference AL, △a and △b between the L value, a value and b value obtained by each measurement and the L value, a value and b value of the initial state are calculated, △E is calculated according to formula I, and no less than 49 times of each standard plate are recorded and calculated;

[0026]

[0027] If the △E and the average △E satisfy the following conditions at the same time:

[0028] The range of the △E of each standard plate is less than or equal to 0.05, the standard deviation of the △E of each standard plate is less than or equal to 0.045, the range of the △E of the three types of standard plates is less than or equal to 0.05, and the standard deviation of the △E of the three types of standard plates is less than or equal to 0.05, the coating is determined to be easy to mix color.

[0029] The present application provides a kind of colored sand sand wall building paint, by mass fraction, including the following components: acrylic polymer emulsion 14.50~18.80%;Hydroxyethyl cellulose 0.18~0.22%;Modified bentonite 0.08~0.10%;Natural colored sand 67.51~73.06%;Transparent color paste 0.68~0.74%;Auxiliary agent 2.70~4.06%;Water 7.80~9.50%;The solid content of the acrylic polymer emulsion is ≥41wt%.The paint provided by the present application uses acrylic polymer emulsion as film-forming resin, completely wets natural colored sand and makes it fully dispersed in the entire coating system, makes the emulsion more permeable after paint preparation, and uses the method of natural colored sand and transparent color paste synergistic color matching, so that the color change during the drying process of the coating after product construction is small, and there is no obvious color difference before and after drying, without completely drying film formation, it can be compared with standard color in wet film state and color adjustment, shorten the color matching time, improve the production efficiency.The acrylic polymer emulsion used in the present application is beneficial to improve the weather resistance of the coating, so that the coating is not easy to fade, and is suitable for wide application and promotion.

[0030] The present application also provides a kind of colored sand sand wall building paint preparation method, the preparation method provided by the present application is simple, and has no adverse effects on operators during production, and is suitable for industrial production.

[0031] The present application also provides a kind of colored sand sand wall building paint color matching difficulty evaluation method, the method provided by the present application is simple and effective, and the evaluation result is accurate. DETAILED DESCRIPTION

[0032] The present application provides a kind of colored sand sand wall building paint, by mass fraction, including the following components:

[0033]

[0034] The solid content of the acrylic polymer emulsion is ≥41wt%.

[0035] Unless otherwise specified, the components used in the present application are commercially available.

[0036] By mass percentage, the components of the colored sand sand wall building paint provided by the present application include acrylic polymer emulsion 14.50~18.80%, preferably 15.5~17.5%, more preferably 16.0~17.0%.The acrylic polymer emulsion used in the present application is prepared by using interpenetrating network polymerization technology and molecular chain segment control, and auxiliary branched chain functional group arrangement technology.The auxiliary agent in the acrylic polymer emulsion is an auxiliary agent that is beneficial to the arrangement of branched chain functional groups in the molecular structure, the particle size of the functional monomer is less than 100nm, the emulsion appearance is transparent or slightly blue, and good permeability is shown.

[0037] In the present application, the water whitening resistance of the acrylic polymer emulsion is preferably ≤5.0, and the specific test method for the water whitening resistance is as follows: the acrylic polymer emulsion is prepared into a film on a transparent flat glass plate by using a 100 μm wet film preparator, the prepared film layer is dried in a blast constant temperature drying oven at 50°C for 30 minutes, after cooling for 1 hour, the film layer is immersed in water for 2 hours, and after drying for 2 hours, the water whitening resistance of the coating film is measured. The test method is tested according to the method described in GB / T 5950-2008 "Building materials and non-metallic mineral products whiteness test method" described method, and the test instrument is preferably SD-500P colorimeter produced by Shanghai Jingqi Instrument Co., Ltd.

[0038] In the present application, the viscosity of the acrylic polymer emulsion is preferably 1500-4500 mPa·s, more preferably 2000-4200 mPa·s, and further preferably 2500-3500 mPa·s, which is measured by using a NDJ-1 type rotary viscometer with a 3# rotor at a rotation speed of 12 rpm and a measurement temperature of 25°C; the solid content of the acrylic polymer emulsion is ≥41 wt%, preferably 44-48 wt%, and more preferably 45-47 wt%. The pH value of the acrylic polymer emulsion is preferably 7.5-8.5; the volatile organic compounds of the acrylic polymer emulsion are preferably ≤20 g / L, and do not contain APEO.

[0039] In the present application, the acrylic polymer emulsion can completely wet the natural colored sand and make it fully dispersed in the entire coating system, so that the coating system after the emulsion paint is more permeable, thereby giving the coating prepared by the coating excellent color development in both dry film and wet film states, highlighting the natural color of the colored sand, realizing zero color difference between dry film and wet film, solving the color matching problem of sand wall building coating, making the color change small during the drying process of the coating after construction, and there is no need to completely dry the film, and the color can be adjusted by comparing the color difference with the standard color in the wet film state, thereby shortening the color matching time. In addition, the acrylic polymer emulsion also gives the coating weather resistance and prevents the coating from fading when forming a dry film. In specific embodiments of the present application, the acrylic polymer emulsion is purchased from Shandong Rossvf New Material Technology Co., Ltd., and the specific model is ROSF-6088; or purchased from Jiangsu Badefu Technology Development Co., Ltd., and the specific model is RS-728.

[0040] The component of the colored sand sand-wall building coating provided by the present application includes 0.18-0.22% of hydroxyethyl cellulose, preferably 0.19-0.22%, and more preferably 0.20-0.22% in terms of mass percentage. In the present application, the hydroxyethyl cellulose is white or slightly yellow powder, the mass fraction of water insoluble substance of the hydroxyethyl cellulose is preferably ≤0.3%, the mass fraction of ash is preferably ≤5%, the mass fraction of water is preferably ≤6%, the mass fraction of salt is preferably ≤1.5%, and the viscosity of 1wt% aqueous solution of the hydroxyethyl cellulose is preferably 1700-2100 mPa·s, the viscosity measurement condition of the 1wt% aqueous solution is that the test temperature is 23±0.5℃, the model of the viscometer is Grade H, the rotor used is 3# rotor, and the test rotation speed is 30 rpm. In the specific embodiment of the present application, the hydroxyethyl cellulose is purchased from Yacross, and the model is HBR250.

[0041] The component of the colored sand sand-wall building coating provided by the present application includes 0.08-0.10% of modified bentonite, preferably 0.09-0.10%, and more preferably 0.09% in terms of mass percentage. In the present application, the modified bentonite is preferably sodium-modified bentonite. In the present application, the whiteness of the modified bentonite is preferably ≥85%, the oil absorption is preferably 55-65%, and the water content is preferably ≤0.5%. In the specific embodiment of the present application, the modified bentonite is purchased from Yixing Snuo New Material Co., Ltd., and the model is SN-8026. In the present application, the modified bentonite has a certain thickening effect and can also prevent color migration when the coating film is formed.

[0042] The component of the colored sand sand-wall building coating provided by the present application includes 67.51-73.06% of natural colored sand, preferably 68.51-72.06%, and more preferably 69.01-71.42% in terms of mass percentage. In the present application, the natural colored sand is preferably sequentially passed through a first-level screen and a second-level screen, and the oversize of the second-level screen is taken; the combination of the first-level screen and the second-level screen is preferably a combination of 40-mesh screen and 60-mesh screen or a combination of 50-mesh screen and 80-mesh screen. In the present application, the screen residue amount of the natural colored sand after passing through the first-level screen is preferably less than or equal to 5% of the total mass of the colored sand, and the undersize after passing through the second-level screen is preferably less than or equal to 20% of the total mass of the colored sand. In the present application, the natural colored sand is preferably natural colored sand that does not change color after being boiled in boiling water for 1 h and does not powder or change color after 1000 h of artificial climate aging resistance experiment. In the specific embodiment of the present application, the natural colored sand is purchased from the Lingshou County Qingyu Mineral Product Processing Factory, and the color of the colored sand can be selected according to the product catalog of the supplier or adjusted according to the requirements of the customer.

[0043] The component of the colored sand sand-wall building paint provided by the present application includes 0.68-0.74% of transparent color paste, preferably 0.69-0.73%, more preferably 0.70-0.72% in terms of mass percentage. In the present application, the transparent color paste is preferably water-based transparent iron oxide color paste. In the present application, the transparent color paste is obtained by dispersing and grinding superfine pigments by using dispersants and water, and has good light resistance, weather resistance and thermal stability, and pure color phase. The transmission of visible light through the superfine pigment particles during the propagation process in the color paste causes diffraction phenomenon, so that the transparent effect of the color paste is optimal, and the color difference between the wet film and the dry film of the paint is reduced. In the present application, the transparent color paste further improves the light resistance and weather resistance of the dry film of the paint, and is beneficial to improve the discoloration phenomenon of the dry film of the paint. In the specific embodiments of the present application, the transparent color paste is purchased from Guangzhou Ruiyue Trade Co., Ltd., and the specific model is RY-02; or purchased from Suzhou Aoleixi Building Material Co., Ltd., and the specific model is SG-01.

[0044] The component of the colored sand sand-wall building paint provided by the present application includes 2.70-4.06% of auxiliary agents in terms of mass percentage. In the present application, the auxiliary agents include pH adjuster, defoaming agent, antifreeze agent, film-forming aid, preservative and mildew-proof agent, thickening agent and slow-drying agent; the content of each auxiliary agent in the colored sand sand-wall building paint is preferably: 0.05-0.07% of pH adjuster; 0.20-0.25% of defoaming agent; 0.66-0.72% of antifreeze agent; 1.08-1.95% of film-forming aid; 0.18-0.22% of preservative and mildew-proof agent; 0.50-0.80% of thickening agent; and 0.03-0.05% of slow-drying agent.

[0045] In the present application, the pH adjuster is included in the colored sand sand-wall building paint in an amount of 0.05-0.07%, preferably 0.06-0.07%, more preferably 0.06% in terms of mass percentage. The pH adjuster is odorless, and the VOC of the pH adjuster is preferably ≤20 g / L. The effective ingredient of the pH adjuster is preferably 2-amino-2-methyl-1-propanol, and the mass fraction of the effective ingredient is preferably ≥52%. In the specific embodiments of the present application, the pH adjuster is purchased from Jiaxing Runcai New Material Technology Co., Ltd., and the specific model is VC-188. In the present application, the pH adjuster has little adverse effect on the corrosion resistance of the preservative and mildew-proof agent, and can reduce the flash rust phenomenon of the iron container containing the paint.

[0046] In the present application, the defoaming agent is included in the colored sand sand-wall building coating in an amount of 0.20-0.25% by mass, preferably 0.21-0.24%, and more preferably 0.22-0.23%. The defoaming agent is preferably a mineral oil type defoaming agent containing fumed silica; the defoaming agent is preferably a yellow or amber opaque liquid, the viscosity of the defoaming agent at 25°C is preferably 350-500 mPa·s, and the specific gravity of the defoaming agent at 20°C is preferably 0.88-0.92 g / mL. In a specific embodiment of the present application, the defoaming agent is purchased from Jiaxing Runcai New Material Technology Co., Ltd., and the specific model is AC-8512 or VC-8211A.

[0047] In the present application, the auxiliary agent includes an antifreeze in an amount of 0.66-0.72% by mass, preferably 0.67-0.71%, and more preferably 0.68-0.70%. The antifreeze is preferably ethylene glycol.

[0048] In the present application, the colored sand sand-wall building coating includes a film-forming aid in an amount of 1.08-1.95% by mass, preferably 1.12-1.75%, and more preferably 1.12-1.65%. The film-forming aid is preferably ≤15 in color (platinum-cobalt colorimetric method), the mass fraction of the active ingredient of the film-forming aid is preferably ≥99.3%, the water content is preferably ≤0.10%, the density of the film-forming aid (20°C) is preferably 0.95 g / cm 3 , and the acidity of the film-forming aid (in mgKOH / g) is preferably ≤0.50%. In a specific embodiment of the present application, the film-forming aid is preferably a hexadecanediol purchased from Jiangsu Run Tai Chemical Co., Ltd. In the present application, the film-forming aid does not have a thickening effect with hydroxyethyl cellulose, which causes a large change in the viscosity of the coating system.

[0049] In the present application, the anticorrosive and antifungal agent is included in the colored sand wall-like building coating in a mass percentage of 0.18-0.22%, preferably 0.19-0.21%, and more preferably 0.20-0.21%. The effective component of the anticorrosive and antifungal agent preferably includes one or more of phenoxyethanol, octanoyl hydroxamic acid and 1,2-octanediol, the appearance of the anticorrosive and antifungal agent is preferably light yellow or yellow-green transparent liquid, the mass fraction of the effective component is preferably ≥2.5%, and the density (20℃) of the anticorrosive and antifungal agent is preferably 1.00-1.10 g / mL. The present application preferably uses the anticorrosive and antifungal agent containing the above components, which can penetrate and destroy the cell wall of bacteria, combine with the intracellular material of bacteria and complex with the enzyme in the nucleus, so as to prevent cell division and reproduction, thereby achieving the bactericidal effect. In the present application, the anticorrosive and antifungal agent has good compatibility with water, fast and efficient bactericidal and anticorrosive effect, a wide pH value range (below 9.5) and no irritation to the human body. In the specific embodiments of the present application, the anticorrosive and antifungal agent is purchased from Sanbo Biochemical Technology (Shanghai) Co., Ltd., and the specific model is 312.

[0050] In the present application, the slow-drying agent is included in the colored sand wall-like building coating in a mass percentage of 0.03-0.05%, preferably 0.04-0.05%, and more preferably 0.04%. The slow-drying agent is preferably magnesium aluminum silicate. In the specific embodiments of the present application, the slow-drying agent is an industrial-grade magnesium aluminum silicate purchased from Jiangsu Haiming New Material Co., Ltd.

[0051] The component of the colored sand wall-like building coating provided by the present application includes water in a mass fraction of 7.61-9.88%, preferably 8.01-9.30%. In the present application, the water is preferably deionized water.

[0052] The present application also provides a preparation method of the colored sand wall-like building coating described in the above scheme, which includes the following steps:

[0053] The acrylic polymer emulsion, hydroxyethyl cellulose, auxiliary agent, modified bentonite, natural colored sand, color paste and water are mixed to obtain the colored sand wall-like building coating.

[0054] In the present application, the specific mixing method preferably includes the following steps: the hydroxyethyl cellulose, water, pH regulator and defoaming agent are first mixed to obtain a dissolution liquid, wherein the water is added in an amount of 50.0%-80.0% of the total mass of water, the pH regulator is added in an amount of 30.0-50.0% of the total mass of the pH regulator, and the defoaming agent is added in an amount of 30.0-50.0% of the total mass of the defoaming agent.

[0055] The dissolving solution, the rest of the pH regulator, the preservative and mildewcide, the acrylic polymer emulsion, the film forming aid, the antifreezing agent, the thickening agent, the slow drying agent and the rest of the water are second mixed to obtain a slurry;

[0056] The slurry, the natural color sand, the transparent color paste, the modified bentonite and the rest of the defoaming agent are third mixed to obtain the color sand wall-like building coating.

[0057] The hydroxyethyl cellulose, the water, the pH regulator and the defoaming agent are first mixed to obtain a dissolving solution. In the present application, the water is preferably added in an amount of 50.0% to 80.0% of the total mass of the water, more preferably 60.0 to 80.0%, and further preferably 60.0 to 70.0%. The pH regulator is preferably added in an amount of 30.0% to 50.0% of the total mass of the pH regulator, more preferably 30.0 to 40.0%, and further preferably 30.0 to 35.0%. The defoaming agent is preferably added in an amount of 30.0% to 50.0% of the total mass of the defoaming agent, more preferably 35.0 to 45.0%, and further preferably 40.0 to 45.0%.

[0058] In the present application, the first mixing is preferably performed by stirring, and the stirring rate is preferably 1200 to 1500 rpm, more preferably 1300 to 1500 rpm, and further preferably 1300 to 1400 rpm. The stirring time is preferably 15 to 20 minutes, more preferably 16 to 20 minutes, and further preferably 16 to 18 minutes. The first mixing is preferably performed by high-speed stirring, which facilitates the uniform mixing of the components. In addition, since the high-speed stirring can increase the temperature of the dissolving solution, the stepwise addition of the pH regulator and the defoaming agent can prevent excessive volatilization of the pH regulator and the defoaming agent, thereby preventing the final performance of the coating from being affected.

[0059] After obtaining the dissolving solution, the dissolving solution, the rest of the pH regulator, the preservative and mildewcide, the acrylic polymer emulsion, the film forming aid, the antifreezing agent, the thickening agent, the slow drying agent and the rest of the water are second mixed to obtain a slurry. In the present application, the second mixing is preferably performed by stirring, and the stirring rate is preferably 800 to 1100 rpm, more preferably 900 to 1100 rpm, and further preferably 900 to 1000 rpm. The stirring time is preferably 5 to 15 minutes, more preferably 8 to 12 minutes, and further preferably 10 to 12 minutes. In a specific embodiment of the present application, the rest of the pH regulator, the preservative and mildewcide, the acrylic polymer emulsion, the film forming aid, the antifreezing agent, the thickening agent, the slow drying agent and the rest of the water are sequentially added to the dissolving solution under stirring to perform the second mixing.

[0060] After obtaining the slurry, the slurry is mixed with natural colored sand, transparent color paste, modified bentonite and the remaining defoaming agent to obtain the colored sand wall building coating. In the present application, the third mixing is preferably stirring, the stirring rate is preferably 500-700 rpm, more preferably 500-650 rpm, further preferably 500-600 rpm, and the stirring time is preferably 5-15 minutes, more preferably 8-15 minutes, further preferably 10-15 minutes. In a specific embodiment of the present application, the natural colored sand, transparent color paste, modified bentonite and the remaining defoaming agent are sequentially added to the slurry under stirring to carry out the third mixing. The present application preferably adopts the method of adding defoaming agent in batches and low-speed stirring, which is beneficial to prevent the excessive volatilization caused by one-time addition of defoaming agent or excessive speed, thereby affecting the performance of the product. In the present application, the initial drying water whitening resistance △W of the colored sand wall building coating meets the requirements of GB / T 5950-2008 "Building materials and non-metallic mineral products whiteness test method", preferably ≤3.0. The specific test method of the initial drying water whitening resistance is as follows: the colored sand wall building coating is sprayed on the standard plate with the same material as the construction substrate under the construction conditions, the spraying thickness is 2-3 mm, and after drying at room temperature for 48 h, a dry film is obtained. The dry film is immersed in water for 24 h and then dried at room temperature for 2 h, and the water whitening resistance of the coating film is measured according to the method described in GB / T 5950-2008 "Building materials and non-metallic mineral products whiteness test method". The test instrument is preferably an SD-500P colorimeter produced by Shanghai Jingqi Instrument Co., Ltd. In the present application, the water whitening resistance △W after dripping of the colored sand wall building coating is preferably ≤3.0, and the specific test method of the water whitening resistance after dripping is as follows: the colored sand wall building coating is sprayed on the standard plate with the same material as the construction substrate under the construction conditions, the spraying thickness is 2-3 mm, and a dry film is obtained after drying at room temperature for 48 h. The dry film is dripped for 4 h, the dripping condition is 30-32 drops / min, after dripping, the dry film is dried at room temperature for 1 h, and the water whitening resistance △W after dripping of the coating film is tested, the measurement method of △W is referred to the method described in GB / T 5950-2008 "Building materials and non-metallic mineral products whiteness test method", and the test instrument is preferably an SD-500P colorimeter produced by Shanghai Jingqi Instrument Co., Ltd.

[0061] The present application also provides an evaluation method for the color matching difficulty of the colored sand wall building coating, specifically:

[0062] The coating is applied to the surfaces of three different types of standard plates respectively; the types of the standard plates include asbestos-cement flat plate, snow board and PV plastic plate; at least one piece of each type of standard plate is applied;

[0063] The color space data of the initial state of the surface coating of each standard plate is measured by using a color difference meter at the end of application, and the color space data includes L value, a value and b value;

[0064] Then the color space data of the surface coating of each standard plate is measured every 30 minutes, the difference AL, Δa and Δb of the L value, a value and b value obtained by each measurement and the initial state L value, a value and b value are calculated, and the ΔE is calculated according to formula I, and each standard plate is recorded and calculated for not less than 49 times;

[0065]

[0066] If the ΔE meets the following conditions at the same time:

[0067] The range of ΔE of each standard plate is less than or equal to 0.05, the standard deviation of ΔE of each standard plate is less than or equal to 0.045, the range of ΔE of three standard plates is less than or equal to 0.05, and the standard deviation of ΔE of three standard plates is less than or equal to 0.05, then the paint is easy to adjust color.

[0068] In the present application, the size of the standard plate is preferably 2.44m*1.22m, and one standard plate of each type is preferably applied. In the present application, the paint is sprayed on the standard plate under construction conditions, and the spraying thickness of the paint is preferably 2-3mm, more preferably 2.5-2.8mm. In specific embodiments of the present application, the asbestos-free fiber cement flat plate is preferably an asbestos-free fiber cement flat plate described in standard JG / T 24-2018. In the present application, the flatness of the surface of the standard plate is subject to the minimum requirement for the flatness of the surface of the construction substrate during the application of the mortar coating in the art.

[0069] In the present application, the model of the color difference meter is preferably CM-2300d. In the present application, when calculating the ΔE, the calculation function of the color difference meter is preferably used for calculation. In the present application, when the paint film is a wet film, a transparent polyurethane film is preferably laid on the wet film before measurement by the color difference meter, and the thickness of the transparent polyurethane film is preferably 0.20-0.30mm, and in the embodiments of the present application, the thickness of the transparent polyurethane film is preferably 0.25mm.

[0070] In the present application, the ΔE is calculated according to formula I, and each standard plate is recorded and calculated for not less than 49 times, preferably 49-50 times. In the present application, when the number of standard plates of each type is the same, the number of times recorded and calculated for each standard plate is preferably the same number, so as to facilitate the comparison between different types of standard plates. In specific embodiments of the present application, one standard plate of each type is applied, and each standard plate is recorded and calculated for 49 times.

[0071] In the present application, if the △E and the average △E satisfy the following conditions at the same time:

[0072] The range of the △E of each standard plate is ≤0.05, the standard deviation of the △E of each standard plate is ≤0.045; and the range of the △E of three standard plates is ≤0.05, the standard deviation of the △E of three standard plates is ≤0.05, then it is determined that the paint is easy to color.

[0073] The technical solutions in the present application will be clearly and completely described below in combination with the embodiments in the present application.

[0074] Sources of raw materials used in Examples 1-3 and Comparative Examples 1-2:

[0075] Acrylic polymer emulsion ROSF-6088: produced by Shandong Rosof New Material Science and Technology Co., Ltd.;

[0076] Acrylic polymer emulsion RS-728: produced by Jiangsu Badu Fu Science and Technology Development Co., Ltd.;

[0077] Hydroxyethyl cellulose HBR250 cellulose: produced by Yacross;

[0078] pH regulator VC-188: produced by Jiaxing Runcai New Material Science and Technology Co., Ltd.;

[0079] Defoaming agent AC-8512: produced by Jiaxing Runcai New Material Science and Technology Co., Ltd.;

[0080] Defoaming agent VC-8211A: produced by Jiaxing Runcai New Material Science and Technology Co., Ltd.;

[0081] Film-forming aid hexadecane diester: produced by Jiangsu Runtai Chemical Co., Ltd.;

[0082] Anticorrosive and mildew-proof agent 312: produced by Sanbo Biochemical Technology (Shanghai) Co., Ltd.;

[0083] Modified bentonite SN-8026: produced by Yixing Snuo New Material Co., Ltd.;

[0084] Thickening agent RM-8W: produced by Guangzhou Hengyu Chemical Co., Ltd.;

[0085] Natural colored sand: produced by Lingshou County Qingyu Mineral Product Processing Factory. The color of the natural colored sand can be selected from the product catalog of the supplier;

[0086] Transparent color paste RY-02 water-based transparent iron oxide color paste: produced by Guangzhou Ruiyue Trade Co., Ltd.;

[0087] Transparent color paste SG-01 water-based transparent iron oxide color paste: Suzhou Ouleixi Building Material Co., Ltd.;

[0088] Magnesium aluminum silicate: produced by Jiangsu Haiming New Material Co., Ltd.

[0089] The water is deionized water.

[0090] Example 1

[0091] The components of the colored sand wall-like building coating are, by mass fraction: acrylic polymer emulsion ROSF-6088 14.50% (water whitening resistance △W is 1.20, viscosity is 2800 mPa·s, solid content is 46.95%, pH value is 8.2), hydroxyethyl cellulose HBR250 0.22%, pH regulator VC-188 0.07%, defoaming agent AC-8512 0.20%, antifreeze agent ethylene glycol 0.66%, film-forming aid hexadecyl diglyceride 1.95%, preservative and mildew-proof agent 312 0.18%, modified bentonite SN-8026 0.08%, thickening agent RM-8W 0.70%; natural colored sand: produced by Lingshou County Qingyu Mineral Product Processing Factory 73.06%, RY-02 water-based transparent iron oxide color paste 0.74%, magnesium aluminum silicate 0.03%, water 7.61%.

[0092] The preparation method of the colored sand wall-like building coating is as follows:

[0093] The hydroxyethyl cellulose, water, pH regulator and defoaming agent are first mixed by stirring at a stirring speed of 1200 revolutions / minute for 20 minutes to obtain a dissolution liquid, wherein the amount of water added is 50.0% of the total mass of water, the amount of pH regulator added is 30.0% of the total mass of pH regulator, and the amount of defoaming agent added is 30.0% of the total mass of defoaming agent.

[0094] The remaining pH regulator, preservative and mildew-proof agent, acrylic polymer emulsion, film-forming aid, antifreeze agent, thickening agent, slow-drying agent and remaining water are sequentially added to the dissolution liquid under stirring to perform second mixing by stirring at a stirring speed of 800 revolutions / minute for 15 minutes to obtain a slurry.

[0095] The natural colored sand, transparent color paste, modified bentonite and remaining defoaming agent are sequentially added to the slurry under stirring to perform third mixing by stirring at a stirring speed of 500 revolutions / minute for 15 minutes to obtain the colored sand wall-like building coating. The initial water whitening resistance △W of the obtained colored sand wall-like building coating is 1.20, and the water whitening resistance △W after water dripping is 1.40.

[0096] Example 2

[0097] The component of the colored sand sand-wall building coating is as follows in mass fraction: acrylic polymer emulsion ROSF-6088 16.50% (water whitening resistance △W is 1.20, viscosity is 2800 mPa·s, solid content is 46.95%, pH value is 8.2), hydroxyethyl cellulose HBR250 0.19%, pH regulator VC-188 0.06%, defoaming agent AC-8512 0.25%, antifreeze agent ethylene glycol 0.70%, film-forming aid hexadecyl diglyceride 1.12%, preservative and mildewcide 312 0.20%, modified bentonite SN-8026 0.09%, thickening agent RM-8W 0.80%; natural colored sand: produced by Lingshou County Qingyu Mineral Product Processing Factory 71.32%, SG-01 water-based transparent iron oxide color paste 0.72%, slow-drying agent magnesium aluminum silicate 0.04%, water 8.01%.

[0098] The preparation method of the colored sand sand-wall building coating is as follows:

[0099] The hydroxyethyl cellulose, water, pH regulator and defoaming agent are first mixed in a stirring manner at a stirring speed of 1300 rpm for 18 minutes to obtain a dissolution liquid, wherein the water is added in an amount of 60.0% of the total mass of the water, the pH regulator is added in an amount of 40.0% of the total mass of the pH regulator, and the defoaming agent is added in an amount of 40.0% of the total mass of the defoaming agent.

[0100] The remaining pH regulator, preservative and mildewcide, acrylic polymer emulsion, film-forming aid, antifreeze agent, thickening agent, slow-drying agent and remaining water are sequentially added to the dissolution liquid in a stirring manner at a stirring speed of 1000 rpm for 10 minutes to obtain a slurry.

[0101] The natural colored sand, transparent color paste, modified bentonite and remaining defoaming agent are sequentially added to the slurry in a stirring manner at a stirring speed of 600 rpm for 10 minutes to obtain the colored sand sand-wall building coating. The initial water whitening resistance △W of the obtained colored sand sand-wall building coating is 1.20, and the water whitening resistance △W after water dripping is 1.50.

[0102] Example 3

[0103] The component of the colored sand sand-wall building coating is as follows in mass fraction: acrylic polymer emulsion RS-728 18.80% (water whitening resistance △W is 4.60, viscosity is 2600 mPa·s, solid content is 46.20%, pH value is 7.9), hydroxyethyl cellulose HBR250 0.18%, pH regulator VC-188 0.05%, defoaming agent AC-8512 0.23%, antifreeze agent ethylene glycol 0.72%, film-forming aid hexadecyl diglyceride 1.08%, preservative and mildewcide 312 0.22%, modified bentonite SN-8026 0.10%, thickening agent RM-8W 0.50%; natural colored sand: 67.51% produced by Lingshou County Qingyu Mineral Product Processing Factory, SG-01 water-based transparent iron oxide color paste 0.68%, slow-drying agent magnesium aluminum silicate 0.05%, water 9.88%.

[0104] The preparation method of the colored sand sand-wall building coating is as follows:

[0105] The hydroxyethyl cellulose, water, pH regulator and defoaming agent are first mixed in a stirring manner at a stirring speed of 1500 rpm for 15 minutes to obtain a dissolution liquid, wherein the water is added in an amount of 80.0% of the total mass of the water, the pH regulator is added in an amount of 50.0% of the total mass of the pH regulator, and the defoaming agent is added in an amount of 50.0% of the total mass of the defoaming agent.

[0106] The remaining pH regulator, preservative and mildewcide, acrylic polymer emulsion, film-forming aid, antifreeze agent, thickening agent, slow-drying agent and remaining water are sequentially added to the dissolution liquid in a stirring manner at a stirring speed of 1100 rpm for 5 minutes to obtain a slurry.

[0107] The natural colored sand, transparent color paste, modified bentonite and remaining defoaming agent are sequentially added to the slurry in a stirring manner at a stirring speed of 700 rpm for 5 minutes to obtain the colored sand sand-wall building coating. The initial water whitening resistance △W of the obtained colored sand sand-wall building coating is 2.80, and the water whitening resistance △W after water dripping is 2.90.

[0108] Comparative Example 1

[0109] The component of the colored sand sand-wall building coating is as follows in mass fraction: acrylic polymer emulsion RS-728 13.80% (water whitening resistance △W is 4.60, viscosity is 2600 mPa·s, solid content is 46.20%, pH value is 7.9), hydroxyethyl cellulose HBR250 0.22%, pH regulator VC-188 0.10%, defoaming agent AC-8512 0.26%, antifreeze agent ethylene glycol 0.66%, film-forming aid hexadecyl diglyceride 1.95%, preservative and mildewcide 312 0.18%, modified bentonite SN-8026 0.22%, thickening agent RM-8W 0.90%; natural colored sand: 73.06% produced by Lingshou County Qingyu Mineral Product Processing Factory, RY-02 water-based transparent iron oxide color paste 0.74%, slow-drying agent magnesium aluminum silicate 0.30%, water 7.61%.

[0110] The preparation method of the colored sand sand-wall building coating is as follows:

[0111] The hydroxyethyl cellulose, water, pH regulator and defoaming agent are first mixed in a stirring manner at a stirring speed of 1500 rpm for 25 minutes to obtain a dissolution liquid, wherein the water is added in an amount of 90.0% of the total mass of the water, the pH regulator is added in an amount of 60.0% of the total mass of the pH regulator, and the defoaming agent is added in an amount of 60.0% of the total mass of the defoaming agent.

[0112] The remaining pH regulator, preservative and mildewcide, acrylic polymer emulsion, film-forming aid, antifreeze agent, thickening agent, slow-drying agent and remaining water are sequentially added to the dissolution liquid in a stirring manner at a stirring speed of 700 rpm for 25 minutes to obtain a paste liquid.

[0113] The natural colored sand, transparent color paste, modified bentonite and remaining defoaming agent are sequentially added to the paste liquid in a stirring manner at a stirring speed of 500 rpm for 20 minutes to obtain the colored sand sand-wall building coating. The initial water whitening resistance △W of the obtained colored sand sand-wall building coating is 5.20, and the water whitening resistance △W after water dripping is 5.50.

[0114] Comparative Example 2

[0115] The component of the colored sand sand-wall building coating is as follows in mass fraction: acrylic polymer emulsion RS-992 18.50% (water whitening resistance △W is 6.2, viscosity is 8000 mPa·s, solid content is 48.32%, pH value is 8.8), hydroxyethyl cellulose HBR250 0.20%, pH regulator VC-188 0.06%, defoaming agent AC-8512 0.25%, antifreeze agent ethylene glycol 0.70%, film-forming aid hexadecyl diglyceride 1.02%, preservative and mildewcide 312 0.20%, modified bentonite SN-8026 0.09%, thickening agent RM-8W 0.40%; natural colored sand: 71.42% produced by Lingshou County Qingyu Mineral Product Processing Factory, SG-01 water-based transparent iron oxide color paste 0.72%, water 6.44%. The acrylic polymer emulsion RS-992 is produced by Jiangsu Badefu Science and Technology Development Co., Ltd., and the acrylic polymer emulsion in Examples 1-3, and the acrylic polymer emulsion has poor permeability compared with the acrylic polymer emulsion in Examples 1-3.

[0116] The preparation method of the colored sand sand-wall building coating is as follows:

[0117] The hydroxyethyl cellulose, water, pH regulator and defoaming agent are first mixed in a stirring manner at a stirring speed of 1500 rpm for 25 minutes to obtain a dissolution liquid, wherein the water is added in an amount of 90.0% of the total mass of the water, the pH regulator is added in an amount of 60.0% of the total mass of the pH regulator, and the defoaming agent is added in an amount of 60.0% of the total mass of the defoaming agent.

[0118] The remaining pH regulator, preservative and mildewcide, acrylic polymer emulsion, film-forming aid, antifreeze agent, thickening agent, slow-drying agent and remaining water are sequentially added to the dissolution liquid in a stirring manner at a stirring speed of 700 rpm for 25 minutes to obtain a paste liquid.

[0119] The natural colored sand, transparent color paste, modified bentonite and remaining defoaming agent are sequentially added to the paste liquid in a stirring manner at a stirring speed of 500 rpm for 20 minutes to obtain the colored sand sand-wall building coating. The initial water whitening resistance △W of the obtained colored sand sand-wall building coating is 6.80, and the water whitening resistance △W after water dripping is 8.20.

[0120] The colored sand sand-wall building coatings obtained in Examples 1-3 and Comparative Examples 1-2 and commercially available colored sand sand-wall building coatings ZSQ-309 (produced by Jiangsu Qimei New Material Co., Ltd.) and BRD-3117 (produced by Baorun New Material Co., Ltd.) are subjected to performance and environmental protection index comparison experiments. The performance index comparison results are shown in Table 1, and the environmental protection index comparison results are shown in Table 2.

[0121] Table 1 Comparison results of performance indicators of each product

[0122]

[0123]

[0124] Table 2 Comparison results of environmental protection indicators of each product

[0125]

[0126]

[0127] As can be seen from Table 1, the colored sand sand wall building coatings prepared by the examples 1-3 and the comparative examples 1-2 of the present application and the commercially available products ZSQ-309 and BRD-3117 all meet the standard technical requirements of JG / T 24-2018 "Synthetic resin emulsion sand wall building coating". Compared with the commercially available products ZSQ-309 and BRD-3117, the colored sand sand wall building coatings prepared by the present application are not easy to powder and discolor, and their light resistance and weather resistance are all better than those of the commercially available products, and are more worthy of popularization and use. As can be seen from Table 2, the colored sand sand wall building coatings prepared by the present application all meet the requirements of GB 18582-2020 "Limitation of Harmful Substances in Architectural Wall Coatings", but the content of volatile organic compounds (VOC) and the content of formaldehyde in the colored sand sand wall building coatings prepared by the present application are lower than those of the commercially available products ZSQ-309 and BRD-3117, and the environmental protection performance is better.

[0128] Application Example 1

[0129] The market commonly used natural colored sand sand wall building coating color card, CR732-gray, CR734-yellow, CR736-red three color sand wall product standard color card. Select 6 color matching engineers engaged in natural colored sand sand wall building coating color matching work for 10 years and with equivalent experience level to color match the coatings prepared by the examples 1-3 and the comparative examples 1-2 of the present application and evaluate the color matching difficulty of each coating.

[0130] The color matching method is as follows: each color matching engineer selects a color sand wall product standard color card for color matching. First, the color space data of the standard color card is measured by a color difference meter, including L value, a value and b value. The product of this color is sprayed on the blank construction substrate, and the spraying thickness is 2-3 mm.

[0131] The color space data of the initial state of the coating on the surface of the construction substrate is measured and recorded at the end of spraying by using a color difference meter, and then the color space data of the coating on the construction substrate is measured every 30 minutes, including L value, a value and b value. When the paint film is a wet film, a layer of transparent polyurethane film with a thickness of 0.25 mm is laid on the wet film, and the color difference meter is used for measurement.

[0132] After obtaining the color space data of the coating on the construction substrate, the difference ΔL, Δa and Δb between the L value, a value and b value obtained by each measurement and the L value, a value and b value of the standard color card are calculated, and ΔE is obtained by the calculation function of the color difference meter according to formula I. If ΔE≤0.3, continue to measure until the coating becomes a dry film, and the color space data of the dry film and the color space data of the standard color card calculated ΔE≤0.3, which indicates that the product of this color does not need to be adjusted and can be used directly. If the ΔE calculated by any one measurement data is greater than 0.3, the color difference between the product of this color and the standard color card is large, and the color adjustment engineer adjusts the product of this color according to the color difference and his own experience, and sprays it on the blank construction substrate again. Repeat the above measurement process until the coating from the initial state of spraying to the dry film, and the color space data measured at any time during the period and the color space data of the standard color card calculated ΔE≤0.3, that is, the color adjustment is qualified. Finally, the number of times of color adjustment and the time of color adjustment required for each color sand wall coating to reach the standard color difference of the color card are obtained. The color adjustment time only includes the time required to adjust the material ratio of the product, and does not include the time of re-spraying and re-measuring data.

[0133] The evaluation method of the difficulty of color adjustment is as follows: the unadjusted coating is applied to the surface of three different types of standard plates, the types of standard plates are the plates prepared from the JG / T 24-2018 recorded non-asbestos fiber cement flat plate to be constructed substrate, snow board and PV plastic plate, under the construction condition, the color plate is sprayed, the spraying thickness is 2-3 mm, each type of standard plate is applied to 1 piece, at the end of application, the color space data of the initial state of the coating on the surface of each standard plate is measured by using a color difference meter, including L value, a value and b value, then the color space data of the coating is measured every 30 minutes, the difference ΔL, Δa and Δb between the L value, a value and b value obtained by each measurement and the L value, a value and b value of the initial state are calculated, and ΔE is calculated according to formula I. A total of 49 times are recorded and calculated.

[0134]

[0135] The △E obtained from each standard plate is denoted as group △E, and the range and standard deviation thereof are calculated. All the △E obtained from the three standard plates are denoted as total △E, and the range and standard deviation thereof are calculated. It is determined whether the group △E and the total △E satisfy the following conditions: the range of the △E obtained from each standard plate is all ≤0.05, and the standard deviation of the △E obtained from each standard plate is all ≤0.045; and the range of the △E obtained from the three standard plates is ≤0.05, and the standard deviation of the △E obtained from the three standard plates is ≤0.05. If yes, it is determined that the paint is easy to color match. The color difference pre-production efficiency verification results are shown in Table 3.

[0136] Table 3 Color difference pre-production efficiency verification table of Examples 1-3 and Comparative Examples 1-2

[0137]

[0138]

[0139] As can be seen from Table 3, the range and standard deviation of the group △E and the total △E of the paint prepared in Examples 1-3 are much smaller than those of the group △E and the total △E of the paint prepared in Comparative Examples 1-2, which indicates that the color difference between the wet film and the dry film of the paint prepared in Examples 1-3 on the same substrate or different substrates is very small, i.e., whether to perform color matching can be determined by directly comparing the color difference between the wet film and the standard color card, without comparing the color difference between the dry film and the standard color card after the wet film is completely dried to form a dry film, thereby greatly saving the time for waiting for drying. In addition, since the paint prepared in Examples 1-3 is added with acrylic polymer emulsion with a suitable mass percentage, and the acrylic polymer emulsion has good permeability, the influence of factors such as the difference between the dry film and the wet film on the color space data is greatly reduced during manual color matching, thereby reducing the difficulty of color matching. Under the premise that the operating personnel have the same experience level, compared with Comparative Examples 1-2, the color matching times are reduced from 3-4 times to 1-2 times, and the color matching time is reduced by 3-7 hours, which indicates that the efficiency of manual color matching is effectively improved.

[0140] The specific data of the color difference values of CR736-red on different standard plates at different times before color matching and the corresponding range and standard deviation are shown in Table 4.

[0141] Table 4 Color difference values of CR736-red on different standard plates at different times and the range and standard deviation

[0142]

[0143]

[0144]

[0145]

[0146] From Table 4, it can be seen that the CR736-red prepared from Example 1 has a maximum difference of △E of 0.05 in the same group, a maximum standard deviation of △E of 0.012 in the same group, a total difference of 0.05, and a total standard deviation of 0.01225, which meet the above-mentioned easy-to-adjust color condition of the coating. It is shown that the color difference between the dry film state and the wet film state of the colored sand wall-like building coating prepared by the present application on different substrates is small, and it is not necessary to wait for the wet film to completely dry to form a dry film before comparing the color difference between the dry film and the standard color card, thereby saving the time for waiting for drying. At the same time, since the color difference between the dry film state and the wet film state of the coating is small, it is shown that the coating is not easily affected by humidity and temperature and other uncontrollable factors, thereby reducing the uncontrollable color adjusting factors for the construction personnel in the process of construction and color adjusting, thereby reducing the color adjusting difficulty and improving the color adjusting efficiency. The comparison data of the color adjusting difficulty of the examples and the comparative examples in Table 3 also show that the evaluation method can obviously distinguish the color adjusting difficulty of the coating, which is beneficial to guide the enterprises to effectively evaluate the color adjusting difficulty of the coating before purchasing, thereby selecting the appropriate coating to reduce the construction period.

[0147] The above only describes the preferred embodiments of the present application, and it should be noted that for ordinary skilled in the art, several improvements and refinements can be made without departing from the principles of the present application, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A colored sand-textured architectural coating, characterized in that, Specifically, it is composed of the following components by mass percentage: Acrylic polymer emulsion 14.50~18.80%; Hydroxyethyl cellulose 0.18~0.22%; Modified bentonite 0.08~0.10%; Natural colored sand 67.51~73.06%; Transparent pigment: 0.68~0.74%; Additives: 2.70~4.06%; Water content: 7.61%–9.88%; The solid content of the acrylic polymer emulsion is ≥41 wt%; The transparent color paste is a water-based transparent iron oxide color paste; The additives, by weight percentage, comprise the following components as a percentage of the colored sand-textured architectural coating: pH adjuster 0.05~0.07%; Defoamer 0.20~0.25%; Antifreeze 0.66~0.72%; Film-forming aids: 1.08~1.95%; Preservative and mildew inhibitor 0.18~0.22%; Thickener 0.50~0.80%; Retarder 0.03~0.05%; The acrylic polymer emulsion has a volatile organic compound content of ≤20g / L and does not contain APEO; The water resistance to whitening of the acrylic polymer emulsion is ΔW≤5.0; The modified bentonite is sodium-modified bentonite with a whiteness ≥85%, an oil absorption of 55~65%, and a water content ≤0.5%.

2. The colored sand-textured architectural coating according to claim 1, characterized in that, The acrylic polymer emulsion has a viscosity of 1500~4500 mPa·s and a pH value of 7.5~8.

5.

3. The method for preparing the colored sand-textured architectural coating according to any one of claims 1 to 2, characterized in that, Includes the following steps: An acrylic polymer emulsion, hydroxyethyl cellulose, additives, modified bentonite, natural colored sand, color paste, and water are mixed to obtain the colored sand-textured architectural coating. The mixing process includes the following steps: Hydroxyethyl cellulose, water, pH adjuster, and defoamer are first mixed to obtain a solution, wherein the amount of water added is 50% to 80% of the total mass of water, the amount of pH adjuster added is 30% to 50% of the total mass of pH adjuster, and the amount of defoamer added is 30% to 50% of the total mass of defoamer. The solution, the remaining pH adjuster, preservative and mildew inhibitor, acrylic polymer emulsion, film-forming aid, antifreeze, thickener, retarder, and the remaining water are mixed a second time to obtain a slurry. The slurry is mixed with natural colored sand, transparent pigment, modified bentonite and the remaining defoamer in a third mixing process to obtain the colored sand-textured architectural coating.

4. The preparation method according to claim 3, characterized in that, The first mixing method is stirring, the stirring rate is 1200~1500 rpm, and the stirring time is 15~20 minutes.

5. The preparation method according to claim 3, characterized in that, The second mixing method is stirring, the stirring rate is 800~1100 rpm, and the stirring time is 5~15 minutes.

6. The preparation method according to claim 3, characterized in that, The third mixing method is stirring, the stirring rate is 500~700 rpm, and the stirring time is 5~15 minutes.

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