Metal calcined sand outer wall colored stone paint and preparation method thereof

Abstract

The invention relates to the technical field of building coatings, in particular to a metal calcined sand exterior wall colored stone paint and a preparation method thereof. The metal calcined sand exterior wall colored stone paint is prepared from the following raw materials in percentage by weight: 10 to 15 percent of acrylic copolymer emulsion, 60 to 70 percent of metal calcined sand, 10 to 15 percent of pearlescent mica powder, 0.2 to 0.5 percent of hydrophobically modified hydroxyethyl cellulose, 0.8 to 1.2 percent of fumed silica, 0.1 to 0.3 percent of compound preservative, 0.1 to 0.3 percent of coalescing agent, 0.1 to 0.3 percent of defoaming agent and the balance of deionized water, the coating further comprises a UV absorbent and AMP-95. The metal calcined sand outer wall colored stone paint is prepared through a step-by-step feeding and precise rotating speed control technology, has the decorative characteristics of metal color and stone stereoscopic impression, has high durability of weather resistance, stain resistance and color retention and excellent constructability of sedimentation resistance and sagging resistance, is attractive and luxurious, is durable, and has a good application prospect. And the system is suitable for various places with high requirements on building facades.

Description

Technical Field

[0001] This invention relates to the field of architectural coatings technology, and in particular to a metal calcined sand exterior wall colored stone paint and its preparation method. Background Technology

[0002] Traditional exterior wall colored stone paint or real stone paint is mainly applied to the exterior walls of buildings or other cement-based substrates to serve both protective and decorative functions; its color effect largely depends on the addition of organic or inorganic pigments for color matching.

[0003] Existing surface treatment processes have several problems: monotonous and dull colors: the color depends entirely on the pigment itself, lacking depth and three-dimensionality, making it difficult to simulate the complex texture of natural stone and the shimmering quality of metal; prone to fading and blooming: especially metallic pigments, during construction or subsequent use, due to the large difference in specific gravity between the metal particles and the base paint, separation and floating of color easily occur, resulting in uneven color, i.e., "blooming," which seriously affects the final decorative effect; limited decorative properties: unable to meet the aesthetic demands of modern high-end architectural design for personalization, diversification, and metallic and pearlescent effects.

[0004] Traditional metallic coatings often use aluminum silver paste, pearlescent powder, etc., directly mixed with the base material. However, these materials have a large density difference from the base material, making them prone to settling, leading to color variations and floating. Furthermore, the metallic orientation is difficult to control, resulting in a narrow application window. Patent CN113136119A uses a protective colloid method to prepare multi-colored coatings, but focuses on suspending gels rather than addressing the stability of metal particles. Patent CN110591427A uses coated colored sand, but does not address the combination of high-temperature calcination and pearlescent effects; its metallic texture and stability still have room for improvement.

[0005] In response to the aforementioned technologies, there is an urgent need in this field to develop a metal calcined sand exterior wall colored stone paint and its preparation method, so as to obtain the effects of high metallic texture, color stability, angle-dependent color effect and excellent workability. Summary of the Invention

[0006] To address the problem of metallic color blooming and to simultaneously impart a unique angle-dependent color effect and a strong metallic texture to the coating, which are shortcomings of existing technologies, this invention provides a metallic calcined sand exterior wall colored stone paint and its preparation method. The prepared coating has a strong metallic texture, uniform and stable color, a beautiful angle-dependent color effect, and excellent workability.

[0007] In the first aspect, this application provides a metal calcined sand exterior wall colored stone paint, which adopts the following technical solution: A metallic calcined sand exterior wall colored stone paint comprises the following raw materials by weight percentage: 10-15% acrylic copolymer emulsion, 60-70% metallic calcined sand, 10-15% pearlescent mica powder, 0.2-0.5% hydrophobically modified hydroxyethyl cellulose, 0.8-1.2% fumed silica, 0.1-0.3% composite preservative, 0.1-0.3% film-forming aid, 0.1-0.3% defoamer, and deionized water to make up the balance.

[0008] By adopting the above scheme, the metallic calcined sand exterior wall colored stone paint achieves its effect through the compatibility and synergistic effect of its components. Acrylic copolymer emulsion serves as the film-forming base, providing tough adhesion and weather resistance. The metallic calcined sand is compounded with pearlescent mica powder. Different mesh sizes of pearlescent mica powder can refract different levels of pearlescent light, changing color with the angle, giving the coating a metallic shimmering texture and natural stone texture. Hydrophobically modified hydroxyethyl cellulose and fumed silica form a composite thickening system, synergistically solving the sedimentation problem of high solids content systems and ensuring storage stability and anti-sagging properties during construction. The composite preservative and UV absorber provide dual protection, effectively resisting algae and mold growth and ultraviolet degradation. Film-forming aids, defoamers, and AMP-95 optimize film-forming efficiency, eliminate bubble defects, and stabilize the pH value of the system, respectively, improving construction tolerance. Ultimately, it achieves the decorative characteristics of metallic brilliance and stone three-dimensionality, high durability with weather resistance, stain resistance, and color retention, and excellent workability with anti-settling and anti-sagging properties. Its effect is not only beautiful and luxurious, but also durable, suitable for various places with high requirements for building facades.

[0009] Preferably, the calcined metal sand comprises the following raw materials in parts by weight: 100 parts of round sand, 5-10 parts of pearlescent mica powder, 0.2-0.5 parts of color powder, 0.5-2 parts of boric acid, 5-15 parts of adhesive, and 5-10 parts of deionized water.

[0010] Preferably, the calcined metal sand is prepared by the following steps: preheating round sand to 80-120°C, mixing it with a pretreatment liquid containing color powder, adhesive and boric acid, so that the pretreatment liquid coats the surface of the round sand; adding pearlescent mica powder and mixing it, so that the pearlescent mica powder adheres to the surface of the round sand, to obtain a mixture; drying the mixture and calcining it at 500-650°C, and cooling it to obtain the calcined metal sand.

[0011] Preferably, the round sand is 40-70 mesh quartz sand or calcined kaolin sand.

[0012] Preferably, the pretreatment solution is obtained by mixing color powder, adhesive, boric acid and deionized water, and stirring evenly.

[0013] Preferably, the mixture is dried at a temperature of 100-120°C until the moisture content is less than 5 wt%.

[0014] Preferably, the specific calcination process is as follows: the temperature is increased from room temperature to 300-350°C at a rate of 3-5°C / min, and held for 20-40 minutes; then the temperature is increased to 500-550°C at a rate of 2-3°C / min, and held for 60-120 minutes. The calcination process is carried out in an air atmosphere or an inert protective atmosphere. The cooling process is carried out in the furnace to a temperature below 200°C and then removed and allowed to cool naturally.

[0015] Preferably, the pearlescent mica powder is used in the preparation of calcined metal sand at a mesh size of 100, and in the exterior wall colored stone paint made of calcined metal sand at a mesh size of 40-60.

[0016] By employing the above-mentioned scheme, through precise step-by-step coating and controlled heat treatment, ordinary sand particles are upgraded into a "core-shell" structured composite aggregate that combines core color, metallic luster, and extremely high stability. Round sand serves as the core matrix, providing the skeletal structure and strength. In the pretreatment solution, color powder imparts the basic color, adhesive initially binds the components, and boric acid acts as a key flux to lower the sintering temperature. Pearl mica powder adheres to form a glossy surface. During the preparation process, step-by-step coating constructs the "core-shell" structure, and segmented temperature-controlled calcination promotes the melting of boric acid, synergistically causing the color powder, mica, and sand particle surface to undergo ceramic sintering, forming a dense glaze layer. Ultimately, a high-performance aggregate with permanent color-matrix fusion, combining ceramic hardness and metallic luster, is obtained. This results in a final paint film exhibiting a rich, three-dimensional shimmering effect, and possessing excellent weather resistance, UV resistance, and color retention, solving the problem of achieving both decorative appeal and durability.

[0017] Preferably, the composite preservative is composed of two or more of methylchloroisothiazolinone, methylisothiazolinone, and benzisothiazolinone.

[0018] Preferably, the composite preservative is methylchloroisothiazolinone, methylisothiazolinone and benzisothiazolinone in a mass ratio of 3:1:(1-2).

[0019] By employing the above-mentioned scheme, methylchloroisothiazolinone (CIT), as the main broad-spectrum bactericide, provides rapid and powerful initial killing ability, instantly eliminating bacteria, molds, and yeasts. Methylisothiazolinone (MIT) synergistically enhances the antibacterial spectrum and strengthens penetration against stubborn bacteria, preventing the development of drug resistance in microorganisms. Benzo[a]isothiazolinone (BIT), with its extremely high chemical stability and alkali resistance, provides long-lasting and effective preservative protection, and its low volatility ensures that the product's performance does not degrade during storage. The three components work together to form a dual guarantee mechanism of "rapid sterilization + long-lasting protection," ultimately enabling this preservative system to possess both instantaneous high efficiency and long-term stability. It is particularly suitable for water-based stone paint systems with high pH and high powder content, effectively solving the problem of microbial spoilage during production and storage, and ensuring product shelf life.

[0020] Preferably, the film-forming aid is any one of dodecyl alcohol ester, dipropylene glycol butyl ether, tripropylene glycol butyl ether, and plant-based diester.

[0021] Preferably, the defoamer is any one of organosilicon defoamers, mineral oil defoamers, and polyether-modified silicone defoamers.

[0022] Preferably, the metal calcined sand exterior wall colored stone paint further includes 0.5-1.0% UV absorber.

[0023] Preferably, the UV absorber is one or more of benzotriazole and triazine compounds.

[0024] By adopting the above scheme, benzotriazole compounds excel at efficiently absorbing ultraviolet light in the UVB band (290-320nm), exhibiting stable molecular structures and good resistance to extraction; triazine compounds, on the other hand, possess higher molar absorptivity and stronger absorption capacity in the UVA band (320-400nm), covering a wider spectrum. The combination of these two compounds achieves broad-spectrum complementary coverage in the ultraviolet absorption spectrum, eliminating the protective blind spots of single components; simultaneously, they mutually promote each other in terms of thermal stability, chemical compatibility, and durability, avoiding the risk of precipitation or film defects caused by excessive addition of a single absorbent; and significantly improving the anti-yellowing, anti-chalking, and color retention properties of the paint film.

[0025] Preferably, the metal calcined sand exterior wall colored stone paint further includes AMP-95 0.1-0.2%.

[0026] By adopting the above scheme, the UV absorber, as the core of UV protection, effectively blocks the degradation effect of ultraviolet rays on acrylic emulsions and color systems by efficiently absorbing ultraviolet radiation in the 290-400nm wavelength band. AMP-95, as a multifunctional additive, precisely adjusts and stabilizes the pH value of the system to the optimal range (7.5-9.5), ensuring that the emulsion, thickener, and preservative perform at their best. Furthermore, as a co-dispersant, it enhances the dispersion stability of pigments and fillers by adsorbing onto their surfaces, preventing flocculation and sedimentation. Both components work synergistically with other components in the system: the UV absorber protects the alkaline stable environment regulated by AMP-95 from UV damage, while AMP-95 ensures the UV absorber's efficient and long-lasting effect in the stable system, simultaneously improving the film-forming stability of the emulsion and the color performance of pigments and fillers. Ultimately, this synergistic effect results in coatings with excellent long-term weather resistance (significantly improved anti-yellowing level), excellent color retention (color durability far exceeding ordinary stone paint), and superior storage stability (no delamination, no discoloration, and long-lasting performance).

[0027] Secondly, this application provides a method for preparing metal calcined sand exterior wall colored stone paint, which adopts the following technical solution: S1 Pre-mixed Slurry Preparation: Under low-speed stirring, hydrophobically modified hydroxyethyl cellulose, composite preservative, AMP-95 and first defoamer are added sequentially to deionized water and stirred until completely dissolved and dispersed to form a uniform pre-mixed slurry. S2 Powder Dispersion: Under stirring, pearl mica powder, fumed silica and UV absorber are added to the pre-made slurry obtained in step S1. The rotation speed is increased to disperse at high speed until the powder is completely and evenly dispersed. S3 Emulsion Introduction: Reduce the rotation speed and add acrylic copolymer emulsion, film-forming aid, and second defoamer to step S2. Stir at low speed to mix evenly and form a uniform slurry. S4 aggregate mixing: Keep stirring at a low speed, slowly add calcined metal sand, and continue stirring until it is completely dispersed and evenly coated by the slurry; S5 Filtration: After filtering the mixture obtained in step S4, the viscosity is adjusted with deionized water to obtain the metal calcined sand exterior wall colored stone paint. The testing personnel will test the indicators.

[0028] Preferably, the speed of low-speed stirring in step S1 is 300-500 rpm; the speed of high-speed dispersion in step S2 is 800-1200 rpm, and the dispersion time is 15-20 minutes; the speed of low-speed stirring in steps S3 and S4 is 400-600 rpm.

[0029] Preferably, the defoamer includes a first defoamer added in step S1 and a second defoamer added in step S3, wherein the mass ratio of the first defoamer to the second defoamer is 1:1.

[0030] Preferably, the filtration in step S5 is performed using a 120-200 mesh filter.

[0031] By adopting the above scheme, step-by-step material addition and precise speed control ensure the stability of the system. In S1, under low-speed stirring, hydrophobically modified hydroxyethyl cellulose is fully hydrated to form a three-dimensional network. AMP-95 adjusts the pH and acts as a co-dispersant, synergistically constructing a stable basic slurry with the composite preservative. In S2, high-speed stirring and dispersion allow the thixotropic network of fumed silica, pearlescent mica powder, and UV absorbers to fully unfold and evenly distribute, eliminating agglomerates. In S3, low-speed stirring introduces acrylic copolymer emulsion and film-forming aids, avoiding shear demulsification and ensuring emulsion integrity. Defoamers are added in two stages to eliminate bubbles in the aqueous and emulsion phases respectively, synergistically achieving full-process defoaming. In S4, low-speed stirring adds calcined metal sand, ensuring the aggregate is completely coated by the slurry and preventing damage to the surface gloss. This method, through precise coordination of timing and shear force, efficiently integrates the thickening network, UV protection, color effect, and film-forming system, ultimately obtaining a high-quality colored stone paint that is stable in storage, smooth to apply, free of sagging, has a dense film, and possesses a lasting metallic sheen and extreme weather resistance.

[0032] In summary, this application has the following beneficial effects: 1. The metallic calcined sand exterior wall colored stone paint prepared in this application, through the combination and synergistic effect of its various components, achieves the decorative characteristics of metallic brilliance and stone three-dimensionality, high durability with weather resistance, stain resistance and color retention, and excellent workability with anti-settlement and anti-sagging properties. Its effect is not only beautiful and luxurious, but also durable and suitable for various places with high requirements for building facades.

[0033] 2. The preparation method of the metallic calcined sand exterior wall colored stone paint of this application ensures the stability of the system through step-by-step feeding and precise speed control, so as to efficiently integrate the thickening network, ultraviolet protection, color effect and film-forming system, and finally obtain a high-quality colored stone paint that is stable in storage, smooth in construction, free from sagging, dense in paint film and has a lasting metallic shimmer effect and extreme weather resistance. Detailed Implementation

[0034] The technical solution of this application is further illustrated by specific embodiments below. These specific embodiments do not represent a limitation on the scope of protection of this application. Any non-essential modifications and adjustments made by others based on the concept of this application still fall within the scope of protection of this application.

[0035] Unless otherwise specified, the experimental methods shown in the following examples are conventional methods. All reagents and materials shown are commercially available products.

[0036] Acrylic copolymer emulsion: Wanhua Chemical Group Co., Ltd., product model: Archsol 8027; Natural pearlescent mica powder: Lingshou County Juzi Mineral Products Processing Plant, item number YMF-1, 40-60 mesh, 100 mesh; Hydrophobically modified hydroxyethyl cellulose: Shandong Heda Group Co., Ltd., Model: C30MS; Methylchloroisothiazolinone: Shandong Kason New Materials Co., Ltd., Product Model: KS-CIT; Methylisothiazolinone: Shandong Kason New Material Co., Ltd., Product Model: KS-MIT; Benzisothiazolinone: Jinan Weizhen Chemical Co., Ltd., Product Model: IT-85; Dimethyl silicone oil: Dongguan Delun New Materials Co., Ltd., Item No.: 201; Polyether-modified polydimethylsiloxane: Guangzhou Huitu New Materials Co., Ltd., Model: HT-403; Fumed silica: Dongguan Baineng New Materials Co., Ltd., Model: AEROSIL A200; Dodecyl alcohol ester: Guangzhou Fuqing Chemical Co., Ltd., Product name: Dodecyl alcohol ester; UV-P: Tianjin Lianlong New Material Co., Ltd., CAS: 2440-22-4, Name: UV-P; UV-1577: Tianjin Lianlong New Material Co., Ltd., CAS: 147315-50-2; Item No.: 07; AMP-95: Henan Haoxuan Chemical Products Co., Ltd., Item No.: 155522.

[0037] The present application will be further described in detail below with reference to embodiments and comparative examples.

[0038] Preparation Example Preparation Example 1: Preparation of calcined metal sand 100 kg of calcined kaolin sand was preheated to 100°C and mixed with a pretreatment liquid, allowing the pretreatment liquid to coat the surface of the sand. 8 kg of 100-mesh pearlescent mica powder was added and mixed, allowing the pearlescent mica powder to adhere to the surface of the sand, resulting in a mixture. The mixture was dried at 100°C until the moisture content was below 5 wt%, and then calcined. The specific calcination process involved heating from room temperature to 300°C at a rate of 4°C / min and holding for 30 minutes; then heating to 500°C at a rate of 2°C / min and holding for 90 minutes. The calcination process was carried out in air or an inert protective atmosphere. Cooling was performed with the furnace to below 200°C, followed by natural cooling, yielding the calcined metal sand.

[0039] Pretreatment solution: Mix 0.4 kg of color powder, 10 kg of adhesive, 1.5 kg of boric acid and 8 kg of deionized water, and stir evenly.

[0040] Preparation Example 2: Preparation of Calcinated Metal Sand 100 kg of calcined kaolin sand was preheated to 80°C and mixed with a pretreatment liquid, allowing the pretreatment liquid to coat the surface of the sand. 5 kg of 100-mesh pearlescent mica powder was added and mixed, allowing the pearlescent mica powder to adhere to the surface of the sand, resulting in a mixture. The mixture was dried at 100°C until the moisture content was below 5 wt%, and then calcined. The specific calcination process involved heating from room temperature to 300°C at a rate of 3°C / min and holding for 20 minutes; then heating to 500°C at a rate of 2°C / min and holding for 60 minutes. The calcination process was carried out in air or an inert protective atmosphere. Cooling was performed with the furnace to below 200°C, followed by natural cooling, yielding the calcined metal sand.

[0041] Pretreatment solution: Mix 0.2 kg of color powder, 5 kg of adhesive, 0.5 kg of boric acid and 5 kg of deionized water, and stir until homogeneous.

[0042] Preparation Example 3: Preparation of Calcinated Metal Sand 100 kg of calcined kaolin sand was preheated to 120°C and mixed with a pretreatment liquid, allowing the pretreatment liquid to coat the surface of the sand. 10 kg of 100-mesh pearlescent mica powder was added and mixed, allowing the pearlescent mica powder to adhere to the surface of the sand, resulting in a mixture. The mixture was dried at 120°C until the moisture content was below 5 wt%, and then calcined. The specific calcination process involved heating from room temperature to 350°C at a rate of 5°C / min and holding for 40 minutes; then heating to 550°C at a rate of 3°C / min and holding for 120 minutes. The calcination process was carried out in air or an inert protective atmosphere. Cooling was performed with the furnace to below 200°C, followed by natural cooling, yielding the calcined metal sand.

[0043] Pretreatment solution: Mix 0.5 kg of color powder, 15 kg of adhesive, 2 kg of boric acid and 10 kg of deionized water and stir evenly. Example

[0044] Example 1 A method for preparing a metallic calcined sand exterior wall colored stone paint, the preparation method is as follows: S1 pre-mixed slurry preparation: under low-speed stirring at 400 rpm, hydrophobically modified hydroxyethyl cellulose, composite preservative, AMP-95 and first defoamer are added sequentially to deionized water and stirred until completely dissolved and dispersed to form a uniform pre-mixed slurry. S2 Powder Dispersion: Under stirring, add pearl mica powder, fumed silica and UV absorber to the pre-made slurry obtained in step S1, increase the speed to 1000 rpm for high-speed dispersion, 20 minutes, until the powder is completely and evenly dispersed. S3 Emulsion Introduction: Reduce the rotation speed to 500 rpm, add acrylic copolymer emulsion, film-forming aid and second defoamer to step S2, stir at low speed to mix evenly and form a uniform slurry; S4 aggregate mixing: Maintain a low stirring speed of 500 rpm, slowly add calcined metal sand, and continue stirring until it is completely dispersed and evenly coated by the slurry; S5 Filtration: After filtering the mixture obtained in step S4 through a 120-200 mesh filter, the viscosity is adjusted with deionized water to obtain the metal calcined sand exterior wall colored stone paint. The testing personnel will then test the relevant indicators.

[0045] The mass ratio of the first defoamer to the second defoamer is 1:1.

[0046] The composition and dosage of the metal calcined sand exterior wall colored stone paint are shown in Table 1: Table 1. Composition and dosage (kg) of metal calcined sand exterior wall colored stone paint in Examples 1-9 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 acrylic copolymer emulsion 12 10 15 12 12 12 12 12 12 Metal calcined sand 65 60 70 65 65 65 65 65 65 40-60 mesh pearlescent mica powder 13 15 10 13 13 13 13 13 13 Hydrophobically modified hydroxyethyl cellulose 0.3 0.2 0.5 0.3 0.3 0.3 0.3 0.3 0.3 silicon dioxide 1 1.2 0.8 1 1 1 1 1 1 Compound Preservative A Formulation 0.2 0.1 0.3 / 0.2 0.2 0.2 0.2 0.2 Compound Preservative B Formulation / / / 0.2 / / / / / Film-forming aid - dodecyl alcohol ester 0.2 0.1 0.3 0.2 0.2 0.2 0.2 0.2 0.2 silicone defoamer 0.2 0.3 0.1 0.2 / / 0.2 0.2 0.2 Mineral oil defoamers / / / / 0.2 / / / / Polyether modified silicone defoamer / / / / / 0.2 / / / UV absorber (UV-P) / / / / / / 0.5 1 / UV absorber (UV-1577) / / / / / / / / 0.5 AMP-95 / / / / / / 0.2 0.1 0.2 Deionized water 8.1 13.1 3 8.1 8.1 8.1 7.4 7 7.4 The calcined metal sand was prepared according to the method described in Preparation Example 1.

[0047] The composite preservative A formulation is a mixture of methylchloroisothiazolinone, methylisothiazolinone, and benzisothiazolinone in amounts of 0.3 kg, 0.1 kg, and 0.1 kg, respectively.

[0048] The organosilicon defoamer is dimethyl silicone oil.

[0049] Example 2 The difference from Example 1 is that: A method for preparing a metallic calcined sand exterior wall colored stone paint, the preparation method is as follows: S1 pre-mixed slurry preparation: under low-speed stirring at 300 rpm, hydrophobically modified hydroxyethyl cellulose, composite preservative, AMP-95 and first defoamer are added sequentially to deionized water and stirred until completely dissolved and dispersed to form a uniform pre-mixed slurry. S2 Powder Dispersion: Under stirring, add pearl mica powder, fumed silica and UV absorber to the pre-made slurry obtained in step S1, increase the speed to 800 rpm for high-speed dispersion, 20 minutes, until the powder is completely and evenly dispersed. S3 Emulsion Introduction: Reduce the rotation speed to 400 rpm, add acrylic copolymer emulsion, film-forming aid and second defoamer to step S2, stir at low speed to mix evenly and form a uniform slurry; S4 aggregate mixing: Maintain a low stirring speed of 40 rpm, slowly add calcined metal sand, and continue stirring until it is completely dispersed and evenly coated with the slurry; S5 Filtration: After filtering the mixture obtained in step S4 through a 120-mesh filter, the viscosity is adjusted with deionized water to obtain the metal calcined sand exterior wall colored stone paint. The testing personnel will then test the relevant indicators.

[0050] The calcined metal sand was prepared according to the scheme of Preparation Example 2.

[0051] The composite preservative A formulation is a mixture of methylchloroisothiazolinone, methylisothiazolinone, and benzisothiazolinone in amounts of 0.3 kg, 0.1 kg, and 0.2 kg, respectively.

[0052] The composition and dosage of the metal calcined sand exterior wall colored stone paint are shown in Table 1.

[0053] Example 3 The difference from Example 1 is that: A method for preparing a metallic calcined sand exterior wall colored stone paint, the preparation method is as follows: S1 pre-mixed slurry preparation: under low-speed stirring at 500 rpm, hydrophobically modified hydroxyethyl cellulose, composite preservative, AMP-95 and first defoamer are added sequentially to deionized water and stirred until completely dissolved and dispersed to form a uniform pre-mixed slurry. S2 Powder Dispersion: Under stirring, add pearl mica powder, fumed silica and UV absorber to the pre-made slurry obtained in step S1, increase the speed to 1200 rpm for high-speed dispersion, 15 minutes, until the powder is completely and evenly dispersed. S3 Emulsion Introduction: Reduce the rotation speed to 600 rpm, add acrylic copolymer emulsion, film-forming aid and second defoamer to step S2, stir at low speed to mix evenly and form a uniform slurry; S4 aggregate mixing: Maintain a low stirring speed of 600 rpm, slowly add calcined metal sand, and continue stirring until it is completely dispersed and evenly coated by the slurry; S5 Filtration: After filtering the mixture obtained in step S4 through a 200-mesh filter, the viscosity is adjusted with deionized water to obtain the metal calcined sand exterior wall colored stone paint. The testing personnel will then test the relevant indicators.

[0054] The calcined metal sand was prepared according to the scheme of Preparation Example 3.

[0055] The composition and dosage of the metal calcined sand exterior wall colored stone paint are shown in Table 1.

[0056] Example 4 The difference from Example 1 is that: The composition and dosage of the metal calcined sand exterior wall colored stone paint are shown in Table 1.

[0057] The compound preservative B formulation is a mixture of methylchloroisothiazolinone and benzisothiazolinone in amounts of 0.3 kg and 0.1 kg, respectively.

[0058] Example 5 The difference from Example 1 is that: The composition and dosage of the metal calcined sand exterior wall colored stone paint are shown in Table 1.

[0059] The mineral oil defoamer is white mineral oil.

[0060] Example 6 The difference from Example 1 is that: The composition and dosage of the metal calcined sand exterior wall colored stone paint are shown in Table 1.

[0061] The polyether-modified silicone defoamer is: polyether-modified polydimethylsiloxane.

[0062] Examples 7-9 The difference from Example 1 is that the composition and dosage of the metal calcined sand exterior wall colored stone paint are shown in Table 1.

[0063] Comparative Example Comparative Example 1 The difference from Example 7 is that no composite preservative is added to the ingredients.

[0064] Comparative Example 2 The difference from Example 7 is that no defoamer is added to the ingredients.

[0065] Comparative Example 3 The difference from Example 7 is that no UV absorber is added to the composition.

[0066] Comparative Example 4 The difference from Example 7 is that AMP-95 is not added to the ingredients.

[0067] Comparative Example 5 The difference from Example 7 is that the ingredients do not contain hydrophobically modified hydroxyethyl cellulose.

[0068] Comparative Example 6 The difference from Example 7 is that no fumed silica is added to the composition.

[0069] Comparative Example 7 The difference from Example 7 is that the amount of acrylic emulsion used in the composition is 8 kg.

[0070] Performance testing 1. Viscosity (cP): A Brookfield DV2T viscometer was used. After the sample was kept at a constant temperature of 25°C, a No. 7 rotor was selected and rotated at a speed of 30 RPM. The viscosity value was recorded after the reading stabilized.

[0071] 2. pH value: The test shall be conducted in accordance with GB / T 1717-1986. The electrode shall be directly inserted into the well-stirred sample and the reading shall be recorded after it stabilizes.

[0072] 3. Workability: Tested according to GB / T 9755-2014.

[0073] 4. Surface drying time: The test shall be conducted in accordance with GB / T 1728-1979 (1989).

[0074] 5. Initial drying crack resistance: Tested according to GB / T 9779-2015.

[0075] 6. Artificial Weathering Resistance: Tested according to GB / T 1865-2009, using a xenon lamp aging test chamber, controlling the blackboard temperature at (63±3)℃, the chamber temperature at (40±3)℃, and the relative humidity at (50±5%), with continuous light exposure and spraying for 18 minutes every 102 minutes; removed after 500 hours. The chalking grade was assessed according to GB / T 1766-2008; the color difference ΔE before and after aging was measured using a colorimeter.

[0076] 7. Stain resistance: Comply with GB / T 9780-2013. Use fly ash as the pollution source, prepare it into a suspension and apply it to the coating surface. After drying, rinse it. Use a reflectometer to measure the rate of decrease in reflectance coefficient and calculate the percentage of staining rate. The lower the value, the better.

[0077] 8. Storage stability: Follow GB / T 6753.3-1986. Place the sample in a sealed plastic or glass jar and put it in a constant temperature oven at (50±2)℃ for 7 days. After cooling to room temperature, open the jar and check the sedimentation level: 10: no sedimentation; 8-9: slight sedimentation, easily redispersible; 5-7: obvious sedimentation, redispersible with effort; 1-4: hard sedimentation, cannot be redispersible.

[0078] The metal calcined sand exterior wall colored stone paint products prepared by the methods of Examples 1-9 and Comparative Examples 1-7 were subjected to the above performance tests, and the test results are shown in Table 2.

[0079] Table 2 Performance Test Results Viscosity (cP) pH value Constructability Drying time (h) Initial drying crack resistance (6h) Powdering grade Color change ΔE Settlement level Status Description Example 1 43500 8.4 good 2.1 pass 1 3.2 10 Uniform, easy to redisperse Example 2 38000 8.3 good 1.8 pass 1 3.7 10 uniform Example 3 52000 8.6 good 2.3 pass 0 2.8 10 Uniform, easy to redisperse Example 4 44000 8.5 good 2 pass 1 3.5 10 Uniform, easy to redisperse Example 5 43000 8.4 good 2.1 pass 1 3.3 10 uniform Example 6 44500 8.5 good 2.1 pass 1 3.2 10 Uniform, easy to redisperse Example 7 45000 8.5 good 1.8 pass 0 2.5 10 Uniform, easy to redisperse Example 8 46000 8.5 good 1.9 pass 0 2 10 Uniform, easy to redisperse Example 9 45500 8.5 good 2 pass 0 1.8 10 Uniform, easy to redisperse Comparative Example 1 44500 8.7 good 2.1 pass - - 3 It smells bad and has spoiled. Comparative Example 2 - 8.5 Range - - - - - - Comparative Example 3 45500 8.5 good 2 pass 3 15.6 10 Uniform, easy to redisperse Comparative Example 4 38000 7.1 good 2 pass 1 4 7 Viscosity decreased significantly, and stratification occurred. Comparative Example 5 15000 8.5 Severe dripping 1.5 Not passed - - 1 Hard sediment, cannot be stirred evenly Comparative Example 6 28000 8.5 Slight drips 2 Not passed 1 3.8 5 Significant settlement and clumping Comparative Example 7 38000 8.3 Slight drips 1.8 Not passed 2 5.3 8 slight settlement As shown in Table 2, the performance test results of Examples 1-6 are balanced, demonstrating the excellent reproducibility and stability of the formulation and the reliability of the production process. Example 7, with the addition of UV absorber and AMP-95, has better performance than Examples 1-6 and good reproducibility. All performance indicators are within the optimal range, and the viscosity (45000 cP) perfectly balances workability and anti-sagging properties. The surface drying time of the paint film is moderate (2 h), and the initial crack resistance is excellent. After aging tests, the chalking grade is 0 and the discoloration ΔE is only 2.5, proving its excellent durability. The storage stability is excellent.

[0080] Comparative Example 1 did not contain any composite preservatives. The storage stability test results of "odor and deterioration" are the most direct evidence. Preservatives do not participate in film formation, so there are no abnormalities in short-term application performance. However, their absence means that the product has no commercial value and will be completely unusable during storage.

[0081] In Comparative Example 2, no defoamer was added, resulting in abundant foam that made viscosity unmeasurable and application impossible. This demonstrates that defoamer is essential in the production process, rather than merely an additive to improve the appearance of the paint film.

[0082] Comparative Example 3, which did not contain any UV absorbers, showed a ΔE as high as 15.6 after 500 hours of aging (severe discoloration) and a chalking level of 3. This is significantly different from Example 7 (ΔE=2.5), demonstrating that UV absorbers are the first line of defense for long-term weather resistance and their role cannot be replaced.

[0083] In Comparative Example 4, without the addition of AMP-95, the pH dropped from 8.5 to 7.1, resulting in a significant decrease in the thickening efficiency of HMHEC, a drop in viscosity from 45,000 cP to 38,000 cP, and triggering storage stratification. This demonstrates that AMP-95 is not simply a pH adjuster, but rather a key component in maintaining the chemical and physical stability of the entire system.

[0084] Comparative Example 5 lacked the main component providing viscosity, causing the viscosity to plummet to 15,000 cP, resulting in severe sagging and making application impossible. Thick-coated paint films cracked due to uneven shrinkage. Comparative Example 6 did not contain fumed silica, lacking the core component providing thixotropy, resulting in decreased anti-settling properties, significant sedimentation and clumping during storage, and a tendency to sagging during application. Both examples demonstrate that the composite thickening scheme of cellulose ether and fumed silica is essential for high-solids colored stone paints, as the two components complement each other and are indispensable.

[0085] The above experimental results show that the metallic calcined sand exterior wall colored stone paint prepared in this application provides balanced adhesion and film toughness through its film-forming substances. The metallic calcined sand and pearlescent mica powder provide the core texture, color, and shimmering effect. The hydrophobically modified hydroxyethyl cellulose and fumed silica form a synergistic thickening system, with HMHEC providing medium shear viscosity to ensure consistency during storage and application. It also provides high thixotropy, giving the product strong anti-settling and anti-sagging capabilities. The composite preservative effectively prevents microbial spoilage. AMP-95 adjusts and stabilizes the pH of the system at 8.5, ensuring that the thickener and preservative perform optimally, while also acting as a co-dispersant to improve the stability of the slurry. The defoamer effectively eliminates bubbles generated during production and use, preventing pinhole defects in the paint film. The UV-P absorber effectively shields ultraviolet rays, protecting the resin and pigments, and is key to long-term weather resistance. The type and dosage of each component have been carefully designed and verified; removing or replacing any component will lead to a significant decrease or even collapse of the system's performance. It achieves a superior balance between workability, film performance, durability, storage stability, and cost. Its excellent weather resistance and unique metallic texture meet the market's dual needs for long-lasting decoration and building protection.

[0086] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but as long as they are within the scope of the present invention, they are protected by patent law.

Claims

1. A metal calcined sand exterior wall colored stone paint, characterized in that, The following raw materials are included by weight percentage: 10-15% acrylic copolymer emulsion, 60-70% calcined metal sand, 10-15% pearlescent mica powder, 0.2-0.5% hydrophobically modified hydroxyethyl cellulose, 0.8-1.2% fumed silica, 0.1-0.3% composite preservative, 0.1-0.3% film-forming aid, 0.1-0.3% defoamer, and deionized water to make up the balance.

2. The metal calcined sand exterior wall colored stone paint according to claim 1, characterized in that, The calcined metal sand comprises the following raw materials in parts by weight: 100 parts round sand, 5-10 parts pearlescent mica powder, 0.2-0.5 parts color powder, 0.5-2 parts boric acid, 5-15 parts adhesive, and 5-10 parts deionized water.

3. The metal calcined sand exterior wall colored stone paint according to claim 2, characterized in that, The calcined metal sand is prepared by the following steps: preheating round sand to 80-120°C, mixing it with a pretreatment solution containing color powder, adhesive and boric acid, so that the pretreatment solution coats the surface of the round sand; adding pearlescent mica powder and mixing it so that the pearlescent mica powder adheres to the surface of the round sand to obtain a mixture; drying the mixture and calcining it at 500-650°C, and cooling it to obtain the calcined metal sand.

4. The metal calcined sand exterior wall colored stone paint according to claim 1, characterized in that, The composite preservative is composed of two or more of methylchloroisothiazolinone, methylisothiazolinone, and benzisothiazolinone.

5. The metal calcined sand exterior wall colored stone paint according to claim 1, characterized in that, The film-forming aid is any one of dodecyl alcohol ester, dipropylene glycol butyl ether, tripropylene glycol butyl ether, and plant-based diester.

6. The metal calcined sand exterior wall colored stone paint according to claim 1, characterized in that, The defoamer is any one of organosilicon defoamers, mineral oil defoamers, and polyether-modified silicone defoamers.

7. The metal calcined sand exterior wall colored stone paint according to claim 1, characterized in that, It also includes 0.5-1.0% UV absorber.

8. The metal calcined sand exterior wall colored stone paint according to claim 1, characterized in that, It also includes AMP-95 0.1-0.2%.

9. A method for preparing the metal calcined sand exterior wall colored stone paint as described in any one of claims 1-8, characterized in that, It includes the following steps: S1 Pre-mixed Slurry Preparation: Under low-speed stirring, hydrophobically modified hydroxyethyl cellulose, composite preservative, AMP-95 and first defoamer are added sequentially to deionized water and stirred until completely dissolved and dispersed to form a uniform pre-mixed slurry. S2 Powder Dispersion: Under stirring, pearl mica powder, fumed silica and UV absorber are added to the pre-made slurry obtained in step S1. The rotation speed is increased to disperse at high speed until the powder is completely and evenly dispersed. S3 Emulsion Introduction: Reduce the rotation speed and add acrylic copolymer emulsion, film-forming aid, and second defoamer to step S2. Stir at low speed to mix evenly and form a uniform slurry. S4 aggregate mixing: Keep stirring at a low speed, slowly add calcined metal sand, and continue stirring until it is completely dispersed and evenly coated by the slurry; S5 Filtration: After filtering the mixture obtained in step S4, the viscosity is adjusted with deionized water to obtain the metal calcined sand exterior wall colored stone paint. The testing personnel will test the indicators.

10. The method for preparing metal calcined sand exterior wall colored stone paint according to claim 9, characterized in that, The speed of low-speed stirring in step S1 is 300-500 rpm; the speed of high-speed dispersion in step S2 is 800-1200 rpm, and the dispersion time is 15-20 minutes; the speed of low-speed stirring in steps S3 and S4 is 400-600 rpm.