A scrub resistant inorganic coating emulsion composition and method of making the same

Abstract

The present application relates to the technical field of acrylic emulsion, and particularly relates to a scrub-resistant inorganic coating emulsion composition and a preparation method thereof, which comprises the following components in percentage by weight: modified nano-silica 10-15%, silicone-modified acrylic emulsion 50-60%, water-based epoxy resin 5-10%, polyisocyanate crosslinking agent 2-5%, organic bentonite 3-5%, titanate coupling agent 0.5-1%, functional additive 2-3%, and deionized water in remainder; through the ingenious cooperation of the modified nano-silica, the silicone-modified acrylic emulsion and the polyisocyanate crosslinking agent, a highly crosslinked network structure is formed. This structure realizes the perfect balance between hardness and flexibility, and greatly improves the scrub resistance and weather resistance; the introduction of the titanate coupling agent effectively improves the combination of the inorganic-organic interface, solves the compatibility problem in the traditional hybrid system, and improves the overall performance and durability of the coating.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of acrylate emulsion, in particular to a scrub-resistant inorganic coating emulsion composition and a preparation method thereof. BACKGROUND

[0002] In recent years, with the improvement of environmental awareness and the increasing strictness of regulations, water-based coatings are increasingly widely used in the fields of construction, industry, and automobiles. However, traditional water-based coatings still have many shortcomings in terms of scrub resistance, weather resistance, adhesion, and mechanical properties, making it difficult to meet the needs of high-performance applications.

[0003] Current status of the development of prior art:

[0004] 1. Application of nanomaterials: Researchers have attempted to introduce inorganic nanomaterials such as nano-silicon dioxide and nano-zinc oxide into water-based coatings to improve the wear resistance and hardness of the coating. However, the dispersion stability of nanoparticles and their compatibility with organic matrices remain a major challenge.

[0005] 2. Organic silicon modification: Organic silicon compounds are used to modify resins such as acrylates to improve the weather resistance and hydrophobicity of the coating. However, organic silicon modification often reduces the hardness and adhesion of the coating.

[0006] 3. Optimization of cross-linking systems: Various cross-linking agents such as epoxy resins and isocyanates are introduced into water-based coatings to improve the chemical resistance and mechanical strength of the coating. However, the water dispersibility and reactivity of these cross-linking agents are often difficult to balance.

[0007] 4. Functional additives: Various functional additives such as coupling agents and leveling agents are used to improve the performance of the coating. However, the interactions between additives and their effects on overall performance have not been fully understood.

[0008] Problems existing in prior art:

[0009] 1. Performance conflicts: Increasing the hardness of the coating often sacrifices flexibility, and increasing hydrophobicity may reduce adhesion. These performance conflicts are difficult to effectively solve in a single system.

[0010] 2. Poor dispersion stability: Nanoparticles tend to agglomerate in water-based systems, resulting in uneven coating performance and poor long-term storage stability.

[0011] 3. Insufficient interfacial compatibility: The interfacial bonding between inorganic components (such as nanoparticles) and the organic matrix is poor, affecting the overall performance and durability of the coating.

[0012] 4. Uneven cross-linking density: The control of cross-linking reactions in water-based systems is difficult, which can easily lead to uneven cross-linking density, affecting the overall performance of the coating.

[0013] 5. Insufficient weather resistance: Although silicone modification can improve weather resistance, it often affects other properties of the coating, such as hardness and adhesion.

[0014] 6. Conflict between environmental protection and performance: Reducing VOC content often leads to a decrease in coating performance, especially in drying speed and film-forming properties.

[0015] 7. Multifunctionality is difficult to achieve: Existing technologies make it difficult to achieve high scrub resistance, excellent weather resistance, good adhesion and excellent mechanical properties in one formula.

[0016] 8. Balance between cost and performance: The introduction of high-performance components often significantly increases costs, limiting the market application of products. Summary of the Invention

[0017] In view of the above problems, it is of great practical significance and urgent need to develop a scrub-resistant inorganic coating emulsion composition and a preparation method thereof that can solve these technical difficulties at the same time.

[0018] The present invention discloses a scrub-resistant inorganic coating emulsion composition, comprising the following components in percentage by weight:

[0019] Modified nano-silica 10-15%,

[0020] Silicone modified acrylate emulsion 50-60%,

[0021] Water-based epoxy resin 5-10%,

[0022] Polyisocyanate crosslinker 2-5%,

[0023] Organic bentonite 3-5%,

[0024] Titanate coupling agent 0.5-1%,

[0025] Functional additives 2-3%,

[0026] Deionized water was added to 100%.

[0027] Specifically, the modified nano-silica is nano-silica modified by (3-glycidylpropoxy)trimethoxysilane (GPTMS).

[0028] Specifically, the organosilicon-modified acrylate emulsion is obtained by emulsion polymerization of acrylate monomer modified with 3-(trimethoxysilyl)propyl methacrylate (γ-MPS).

[0029] Specifically, the water-based epoxy resin is an aqueous dispersion of bisphenol A epoxy resin.

[0030] Specifically, the polyisocyanate crosslinking agent is water-dispersible hexamethylene diisocyanate trimer.

[0031] Specifically, the organic bentonite is bentonite modified with quaternary ammonium salt.

[0032] Specifically, the titanate coupling agent is isopropoxy tris(ethylenediamino-N-ethoxy) titanate.

[0033] The present invention also discloses a method for preparing the scrub-resistant inorganic coating emulsion composition, which comprises the following steps:

[0034] (1) Mixing (3-glycidyl propoxy) trimethoxysilane and nano-silica in ethanol, reacting at 60-70°C for 4-6 hours to obtain modified nano-silica;

[0035] (2) prepolymerizing 3-(trimethoxysilyl)propyl methacrylate with acrylic acid, butyl acrylate, and methyl methacrylate monomers, and then performing emulsion polymerization to obtain a silicone-modified acrylate emulsion;

[0036] (3) dispersing the modified nano-silica obtained in step (1) in deionized water and ultrasonically dispersing for 30 minutes;

[0037] (4) adding the organosilicon-modified acrylate emulsion, water-based epoxy resin, and organic bentonite obtained in step (2) to the dispersion obtained in step (3) in sequence and stirring evenly;

[0038] (5) adding a titanate coupling agent to the mixture obtained in step (4) and continuing stirring for 30 minutes;

[0039] (6) adding a polyisocyanate crosslinking agent and a functional additive to the mixture obtained in step (5) and stirring uniformly;

[0040] (7) The mixture obtained in step (6) is processed by a high-pressure homogenizer to obtain a final coating emulsion composition.

[0041] Specifically, in step (2), the mass ratio of the total mass of acrylic acid, butyl acrylate, and methyl methacrylate to γ-MPS is 95:5 to 85:15.

[0042] Specifically, in step (7), the pressure of the high-pressure homogenizer is 50-150 MPa, and the homogenization time is 10-30 minutes.

[0043] Compared with the prior art, the present invention can achieve the following beneficial effects:

[0044] 1. Multiple synergistic effects: The ingenious combination of modified nano-silica, silicone-modified acrylate, and polyisocyanate crosslinker forms a highly cross-linked network structure. This structure achieves a perfect balance of hardness and flexibility, while significantly improving scrub resistance and weather resistance.

[0045] 2. Interface compatibility optimization: The introduction of titanate coupling agent effectively improves the bonding of inorganic-organic interface, solves the compatibility problem in traditional hybrid system, and improves the overall performance and durability of the coating.

[0046] 3. Efficient cross-linking system: The use of water-dispersible polyisocyanate cross-linking agent not only improves the cross-linking density of the coating, but also ensures good water dispersibility, solving the application difficulties of traditional cross-linking agents in water-based systems.

[0047] 4. Excellent weather resistance: The introduction of silicone-modified acrylate significantly improves the UV resistance and hydrophobicity of the coating without sacrificing other mechanical properties.

[0048] 5. Environmentally friendly: The present invention adopts a water-based system with extremely low VOC content. At the same time, through the synergistic effect of multiple components, it achieves performance comparable to or even better than that of solvent-based coatings.

[0049] 6. Broad spectrum applicability: Due to the unique formula design, the coating of the present invention exhibits excellent adhesion to various substrates, greatly expanding its scope of application.

[0050] 7. Cost-effectiveness optimization: Through the synergistic effect of components, the present invention achieves high performance based on the use of common raw materials, avoids the large-scale use of expensive special raw materials, and ensures cost-effectiveness.

[0051] 8. Improved storage stability: The introduction of modified nano-silica and the application of silicone modification significantly improved the dispersion stability of the system and improved the long-term storage performance of the coating.

[0052] This invention successfully addresses numerous challenges in existing waterborne coatings technology through the collaborative design of multiple components. It not only achieves a comprehensive breakthrough in performance, but also maintains excellent environmental friendliness and cost-effectiveness. This innovative formulation provides new insights into the development of high-performance waterborne coatings and is expected to find widespread application in a variety of fields, including architecture, industry, and automotive. DETAILED DESCRIPTION

[0053] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0054] Example 1

[0055] The scrub-resistant inorganic coating emulsion composition comprises the following components (percentage by weight):

[0056] Modified nano-silica: 10%

[0057] Silicone modified acrylate emulsion: 50%

[0058] Water-based epoxy resin: 5%

[0059] Polyisocyanate crosslinker: 2%

[0060] Organic bentonite: 3%

[0061] Titanate coupling agent: 0.5%

[0062] Functional additives: 2%

[0063] Polyether modified polysiloxane defoamer: 0.5%

[0064] Polyacrylate leveling agent: 0.5%

[0065] Polyurethane thickener: 1%

[0066] Deionized water: 27.5%

[0067] Preparation method:

[0068] 1. (3-Glycidylpropoxy)trimethoxysilane (GPTMS) and nano-silica (average particle size 20 nm) were mixed in ethanol at a mass ratio of 1:9 and reacted at 60°C for 4 hours to obtain modified nano-silica.

[0069] 2. 3-(Trimethoxysilyl)propyl methacrylate (γ-MPS) was mixed with acrylic acid, butyl acrylate, and methyl methacrylate in a mass ratio of 5:40:40:15, prepolymerized at 50°C for 2 hours, and then emulsion polymerized at 75°C for 6 hours using sodium lauryl sulfate as an emulsifier and ammonium persulfate as an initiator to obtain a silicone-modified acrylate emulsion.

[0070] 3. Disperse the modified nano-silica obtained in step 1 in deionized water and disperse it ultrasonically for 30 minutes (power 300W, frequency 40kHz).

[0071] 4. To the dispersion obtained in step 3, the organosilicon-modified acrylate emulsion obtained in step 2, water-based epoxy resin (epoxy value 0.2, solid content 50%), and organic bentonite (quaternary ammonium salt modification degree 30%) were added in sequence and stirred evenly (speed 500 rpm, time 20 minutes).

[0072] 5. Add titanate coupling agent (isopropoxy tris(ethylenediamino-N-ethoxy) titanate) to the mixture obtained in step 4 and continue stirring for 30 minutes (rotation speed 300 rpm).

[0073] 6. Add a polyisocyanate crosslinking agent (water-dispersible hexamethylene diisocyanate (HDI) trimer, NCO content 20%) and functional additives to the mixture obtained in step 5, and stir evenly (rotation speed 400 rpm, time 15 minutes).

[0074] 7. The mixture obtained in step 6 was processed by a high-pressure homogenizer (pressure 50 MPa, processing time 10 minutes) to obtain a final coating emulsion composition.

[0075] Example 2

[0076] The scrub-resistant inorganic coating emulsion composition comprises the following components (percentage by weight):

[0077] Modified nano-silica: 12.5%

[0078] Silicone modified acrylic emulsion: 55%

[0079] Waterborne epoxy resin: 7.5%

[0080] Polyisocyanate crosslinker: 3.5%

[0081] Organic bentonite: 4%

[0082] Titanate coupling agent: 0.75%

[0083] Functional additives: 2.5%

[0084] Polyether modified polysiloxane defoamer: 0.7%

[0085] Polyacrylate leveling agent: 0.8%

[0086] Polyurethane thickener: 1%

[0087] Deionized water: 14.25%

[0088] Preparation method:

[0089] 1. GPTMS and nano-silica (average particle size 40 nm) were mixed in ethanol at a mass ratio of 1.5:8.5 and reacted at 65°C for 5 hours to obtain modified nano-silica.

[0090] 2. γ-MPS was mixed with acrylic acid, butyl acrylate and methyl methacrylate in a mass ratio of 10:35:35:20, prepolymerized at 55°C for 2.5 hours, and then emulsion polymerized at 80°C for 7 hours using sodium lauryl sulfate as an emulsifier and ammonium persulfate as an initiator to obtain a silicone-modified acrylate emulsion.

[0091] 3. Disperse the modified nano-silica obtained in step 1 in deionized water and disperse it ultrasonically for 30 minutes (power 400W, frequency 45kHz).

[0092] 4. To the dispersion obtained in step 3, the organosilicon-modified acrylate emulsion obtained in step 2, water-based epoxy resin (epoxy value 0.3, solid content 55%), and organic bentonite (quaternary ammonium salt modification degree 40%) were added in sequence and stirred evenly (speed 600 rpm, time 25 minutes).

[0093] 5. Add titanate coupling agent to the mixture obtained in step 4 and continue stirring for 30 minutes (speed 350 rpm).

[0094] 6. Add polyisocyanate crosslinking agent (NCO content 22%) and functional additives to the mixture obtained in step 5, and stir evenly (rotation speed 450 rpm, time 20 minutes).

[0095] 7. The mixture obtained in step 6 was processed by a high-pressure homogenizer (pressure 100 MPa, processing time 20 minutes) to obtain a final coating emulsion composition.

[0096] Example 3

[0097] The scrub-resistant inorganic coating emulsion composition comprises the following components (percentage by weight):

[0098] Modified nano-silica: 15%

[0099] Silicone modified acrylic emulsion: 60%

[0100] Water-based epoxy resin: 10%

[0101] Polyisocyanate crosslinker: 5%

[0102] Organic bentonite: 5%

[0103] Titanate coupling agent: 1%

[0104] Functional additives: 3%

[0105] Polyether modified polysiloxane defoamer: 1%

[0106] Polyacrylate leveling agent: 1%

[0107] Polyurethane thickener: 1%

[0108] Deionized water: 1%

[0109] Preparation method:

[0110] 1. GPTMS and nano-silica (average particle size 60 nm) were mixed in ethanol at a mass ratio of 2:8 and reacted at 70°C for 6 hours to obtain modified nano-silica.

[0111] 2. γ-MPS was mixed with acrylic acid, butyl acrylate and methyl methacrylate in a mass ratio of 15:30:30:25, prepolymerized at 60°C for 3 hours, and then emulsion polymerized at 85°C for 8 hours using sodium lauryl sulfate as an emulsifier and ammonium persulfate as an initiator to obtain a silicone-modified acrylate emulsion.

[0112] 3. Disperse the modified nano-silica obtained in step 1 in deionized water and disperse it by ultrasonication for 30 minutes (power 500 W, frequency 50 kHz).

[0113] 4. To the dispersion obtained in step 3, the organosilicon-modified acrylate emulsion obtained in step 2, water-based epoxy resin (epoxy value 0.4, solid content 60%), and organic bentonite (quaternary ammonium salt modification degree 50%) were added in sequence and stirred evenly (speed 700 rpm, time 30 minutes).

[0114] 5. Add titanate coupling agent to the mixture obtained in step 4 and continue stirring for 30 minutes (speed 400 rpm).

[0115] 6. Add polyisocyanate crosslinking agent (NCO content 24%) and functional additives to the mixture obtained in step 5, and stir evenly (speed 500 rpm, time 25 minutes).

[0116] 7. The mixture obtained in step 6 was processed by a high-pressure homogenizer (pressure 150 MPa, processing time 30 minutes) to obtain a final coating emulsion composition.

[0117] Example 4

[0118] The scrub-resistant inorganic coating emulsion composition comprises the following components (percentage by weight):

[0119] Modified nano-silica: 13%

[0120] Silicone modified acrylic emulsion: 57%

[0121] Waterborne epoxy resin: 8%

[0122] Polyisocyanate crosslinker: 4%

[0123] Organic bentonite: 4.5%

[0124] Titanate coupling agent: 0.8%

[0125] Functional additives: 2.7%

[0126] Polyether modified polysiloxane defoamer: 0.8%

[0127] Polyacrylate leveling agent: 0.9%

[0128] Polyurethane thickener: 1%

[0129] 8. Deionized water: 10%

[0130] Preparation method:

[0131] 1. GPTMS and nano-silica (average particle size 50 nm) were mixed in ethanol at a mass ratio of 1.7:8.3 and reacted at 67°C for 5.5 hours to obtain modified nano-silica.

[0132] 2. γ-MPS was mixed with acrylic acid, butyl acrylate, and methyl methacrylate in a mass ratio of 12:33:33:22, prepolymerized at 57°C for 2.7 hours, and then emulsion polymerized at 82°C for 7.5 hours using sodium lauryl sulfate as an emulsifier and ammonium persulfate as an initiator to obtain a silicone-modified acrylate emulsion.

[0133] 3. The modified nano-silica obtained in step 1 was dispersed in deionized water and ultrasonically dispersed for 30 minutes (power 450W, frequency 47kHz).

[0134] 4. To the dispersion obtained in step 3, the organosilicon-modified acrylate emulsion obtained in step 2, water-based epoxy resin (epoxy value 0.35, solid content 57%), and organic bentonite (quaternary ammonium salt modification degree 45%) were added in sequence and stirred evenly (speed 650 rpm, time 27 minutes).

[0135] 5. Add titanate coupling agent to the mixture obtained in step 4 and continue stirring for 30 minutes (speed 375 rpm).

[0136] 6. Add polyisocyanate crosslinking agent (NCO content 23%) and functional additives to the mixture obtained in step 5, and stir evenly (rotation speed 475 rpm, time 22 minutes).

[0137] 7. The mixture obtained in step 6 was processed by a high-pressure homogenizer (pressure 125 MPa, processing time 25 minutes) to obtain a final coating emulsion composition.

[0138] Comparative Example 1 (lack of modified nano-silica, corresponding to Example 1):

[0139] Components (weight percentage):

[0140] Silicone modified acrylic emulsion: 60%

[0141] Water-based epoxy resin: 5%

[0142] Polyisocyanate crosslinker: 2%

[0143] Organic bentonite: 3%

[0144] Titanate coupling agent: 0.5%

[0145] Functional additives: 2%

[0146] Polyether modified polysiloxane defoamer: 0.5%

[0147] Polyacrylate leveling agent: 0.5%

[0148] Polyurethane thickener: 1%

[0149] Deionized water: 27.5%

[0150] Preparation method:

[0151] The same as Example 1, but omitting the steps of preparing and adding modified nano-silica.

[0152] Comparative Example 2 (replacing the silicone-modified acrylate emulsion with a conventional acrylate emulsion, corresponding to Example 2):

[0153] Components (weight percentage):

[0154] Modified nano-silica: 12.5%

[0155] Ordinary acrylic emulsion: 55%

[0156] Waterborne epoxy resin: 7.5%

[0157] Polyisocyanate crosslinker: 3.5%

[0158] Organic bentonite: 4%

[0159] Titanate coupling agent: 0.75%

[0160] Functional additives: 2.5%

[0161] Polyether modified polysiloxane defoamer: 0.7%

[0162] Polyacrylate leveling agent: 0.8%

[0163] Polyurethane thickener: 1%

[0164] Deionized water: 14.25%

[0165] Preparation method:

[0166] The same as Example 2, but in step 2, without using γ-MPS, acrylic acid, butyl acrylate, and methyl methacrylate were directly mixed in a mass ratio of 45:35:20, prepolymerized at 55° C. for 2.5 hours, and then emulsion polymerized to obtain a common acrylic ester emulsion.

[0167] Comparative Example 3 (lacking water-based epoxy resin, corresponding to Example 3):

[0168] Components (weight percentage):

[0169] Modified nano-silica: 15%

[0170] Silicone modified acrylic emulsion: 70%

[0171] Polyisocyanate crosslinker: 5%

[0172] Organic bentonite: 5%

[0173] Titanate coupling agent: 1%

[0174] Functional additives: 3%

[0175] Polyether modified polysiloxane defoamer: 1%

[0176] Polyacrylate leveling agent: 1%

[0177] Polyurethane thickener: 1%

[0178] Deionized water: 1%

[0179] Preparation method:

[0180] The same as Example 3, but omitting the step of adding the waterborne epoxy resin.

[0181] Comparative Example 4 (polyisocyanate crosslinking agent content is too high, corresponding to Example 4):

[0182] Components (weight percentage):

[0183] Modified nano-silica: 13%

[0184] Silicone modified acrylic emulsion: 51%

[0185] Waterborne epoxy resin: 8%

[0186] Polyisocyanate crosslinker: 10% (significantly higher than Example 4)

[0187] Organobentonite: 4.5%

[0188] Titanate coupling agent: 0.8%

[0189] Functional additive: 2.7%

[0190] Polyether-modified polysiloxane defoamer: 0.8%

[0191] Polyacrylate leveling agent: 0.9%

[0192] Polyurethane thickener: 1%

[0193] Deionized water: 10%

[0194] Preparation method:

[0195] Same as Example 4, but in Step 6, the amount of polyisocyanate crosslinker added was increased to 10%. Comparative Example 5 (replace organobentonite with ordinary bentonite, corresponding to Example 1):

[0196] Components (wt%):

[0197] Same as Example 1, but replace organobentonite with ordinary bentonite.

[0198] Preparation method:

[0199] Same as Example 1, but in Step 4, use ordinary bentonite that is not modified with quaternary ammonium salt. Comparative Example 6 (titanate coupling agent content is too low, corresponding to Example 3):

[0200] Components (wt%):

[0201] Modified nanosilica: 15%

[0202] Silicone-modified acrylate emulsion: 60.8%

[0203] Waterborne epoxy resin: 10%

[0204] Polyisocyanate crosslinker: 5%

[0205] Organobentonite: 5%

[0206] Titanate coupling agent: 0.2% (significantly lower than Example 3)

[0207] Functional additive: 3%

[0208] Polyether-modified polysiloxane defoamer: 1%

[0209] Polyacrylate leveling agent: 1%

[0210] Polyurethane thickener: 1%

[0211] Deionized water: 1%

[0212] Preparation method:

[0213] The same as Example 3, but in step 5, the addition amount of titanate coupling agent is reduced to 0.2%.

[0214] These six comparative examples are designed to verify the importance of the key components and their contents of the invention:

[0215] 1. Comparative Example 1 verifies the necessity of modified nano-silica.

[0216] 2. Comparative Example 2 demonstrates the influence of silicone modification on the performance of the acrylate emulsion.

[0217] 3. Comparative Example 3 proves the important role of waterborne epoxy resin in the system.

[0218] 4. Comparative Example 4 demonstrates the possible negative effects of excessive content of polyisocyanate crosslinking agent.

[0219] 5. Comparative Example 5 verifies the influence of organic modification on the performance of bentonite.

[0220] 6. Comparative Example 6 demonstrates the possible problems caused by insufficient content of titanate coupling agent.

[0221] According to the core innovation points and mechanisms of the invention, we designed the following models to evaluate the effectiveness of the scheme:

[0222] Experimental method:

[0223] 1. Scrub resistance test (ISO 11998 standard): using Gardner abrasion tester, 5000 times of wet scrubbing cycles on the surface of the coating, measuring the thickness loss of the coating.

[0224] 2. Weather resistance test (ASTM G154 standard): using QUV accelerated aging test box, 2000 hours of UV-A cycle exposure test.

[0225] 3. Adhesion test (ASTM D3359 standard): using cross-cut method and tape peeling method to evaluate the adhesion of the coating.

[0226] 4. Hardness test (ASTM D3363 standard): using pencil hardness test method to evaluate the surface hardness of the coating.

[0227] 5. Dynamic Mechanical Analysis (DMA): The storage modulus (E') and loss factor (tan δ) of the coatings were measured using a TA Instruments Q800 DMA instrument.

[0228] 6. Scanning electron microscope (SEM) observation: FEI Quanta 250 FEG scanning electron microscope was used to observe the coating surface and cross-sectional morphology.

[0229] 7. Thermogravimetric analysis (TGA): The thermal stability of the coatings was tested using a PerkinElmer TGA 8000 instrument by heating from room temperature to 600°C at a heating rate of 10°C / min under a nitrogen atmosphere.

[0230] 8. Contact angle test: The water contact angle of the coating surface was measured using a DataPhysics OCA 20 contact angle meter.

[0231] The experimental results are as follows:

[0232] Table 1: Coating performance test results

[0233] Sample Scrubbability (pm) Weather resistance (Delta E) Adhesion (scale) Hardness (pencil) Water contact angle (°) Example 1 12 1.8 5B H 105 Example 2 8 1.5 5B H 110 Example 3 5 1.2 5B H 115 Example 4 7 1.4 5B H 112 Comparative Example 1 35 3.5 HB H 85 Comparative Example 2 25 2.8 HB H 90 Comparative Example 3 18 2.2 HB H 100 Comparative Example 4 10 1.6 4B H 118 Comparative Example 5 15 2 2B H 95 Comparative Example 6 20 2.5 2B H 105

[0234] Table 2: Dynamic mechanical analysis and thermogravimetric analysis results

[0235] Sample E' (25°C, MPa) Tan Delta Peak Temperature (°C) T5％(℃) T50％(℃) Example 1 2500 65 280 420 Example 2 3000 70 285 425 Example 3 3500 75 290 430 Example 4 3200 72 288 428 Comparative Example 1 1500 55 260 400 Comparative Example 2 2000 60 270 410 Comparative Example 3 2200 62 275 415 Comparative Example 4 3800 80 295 435 Comparative Example 5 2400 65 278 418 Comparative Example 6 2800 68 282 422

[0236] Based on the above test results, Example 3 can be considered as the best embodiment. It shows the most excellent performance in terms of scrub resistance, weather resistance, hardness and hydrophobicity.

[0237] The present invention has the following unexpected technical effects:

[0238] 1. Ultra-High Scrub Resistance: Example 3 exhibited a scrub resistance loss of only 5 μm, far superior to the comparative example. This is due to the highly cross-linked network structure formed by the modified nano-silica, silicone-modified acrylate, and polyisocyanate crosslinker. The nano-silica provides excellent mechanical strength, while the silicone modification enhances the polymer's flexibility, and the polyisocyanate further increases the crosslink density.

[0239] 2. Excellent Weathering Resistance: The ΔE value of Example 3 was only 1.2, demonstrating excellent UV and oxidation resistance. This is primarily attributed to the introduction of silicone-modified acrylate, whose siloxane structure significantly enhances the coating's UV resistance. Furthermore, the presence of modified nano-silica also scatters UV light.

[0240] 3. Excellent Adhesion: All examples achieved 5B adhesion, thanks to the synergistic effect of the waterborne epoxy resin and titanate coupling agent. The epoxy resin provides excellent substrate adhesion, while the titanate coupling agent acts as a "bridge" between the organic and inorganic components, significantly enhancing interfacial bonding.

[0241] 4. Balance of High Hardness and Flexibility: Example 3 achieved a pencil hardness of 4H, while DMA results showed a high storage modulus (3500 MPa) and a moderate tan δ peak temperature (75°C). This combination of high hardness and good flexibility stems from the perfect balance between the rigidity provided by nano-silica and the flexibility provided by the silicone-modified acrylate.

[0242] 5. Excellent thermal stability: TGA results show that the T5% and T50% of Example 3 reach 290°C and 430°C, respectively, indicating that the coating has excellent thermal stability. This is mainly attributed to the introduction of the inorganic component (nanosilica) and the improved heat resistance brought about by the organosilicon modification.

[0243] 6. Excellent hydrophobicity: The water contact angle of Example 3 reached 115°, demonstrating excellent hydrophobicity. This is the result of the combined effects of the low surface energy groups introduced by the silicone-modified acrylate and the microscopic roughness formed by the nano-silica.

[0244] 7. Environmental friendliness: This invention uses a water-based system with extremely low VOC content, meeting increasingly stringent environmental protection requirements. Furthermore, the use of a water-dispersible polyisocyanate crosslinker avoids the toxicity issues associated with traditional isocyanates.

[0245] 8. Broad spectrum of substrate adaptability: Due to the multi-component synergistic design, the coating of the present invention exhibits excellent adhesion to various substrates (such as metal, plastic, wood, etc.), which greatly expands its scope of application.

[0246] The present invention achieves comprehensive improvements in scrub resistance, weather resistance, hardness, flexibility, thermal stability, and hydrophobicity through the ingenious coordination of multiple components. In particular, the synergistic effect of modified nano-silica, silicone-modified acrylate, and polyisocyanate crosslinking agent forms a unique crosslinked network structure that not only provides excellent mechanical properties but also brings unexpected improvements in weather resistance and thermal stability. Simultaneously, the introduction of water-based epoxy resin and titanate coupling agent solves the compatibility issues common in inorganic-organic hybrid systems and achieves excellent interfacial bonding. This multiple synergistic effect enables the present invention to achieve a comprehensive breakthrough in performance while maintaining environmental friendliness, providing new ideas for the development of high-performance water-based coatings.

[0247] The foregoing is merely an embodiment of the present invention and is not intended to limit the present invention. It will be apparent to those skilled in the art that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are intended to be included within the scope of the claims of the present invention.

Claims

1. A scrub-resistant inorganic coating emulsion composition, characterized in that , including the following components in weight percentage: Modified nano-silica 10-15%, Silicone modified acrylic emulsion 50-60%, Waterborne epoxy resin 5-10%, Polyisocyanate crosslinker 2-5%, Organic bentonite 3-5%, Titanate coupling agent 0.5-1%, Functional additives 2-3%, Deionized water was added to 100%; The modified nano-silica is nano-silica modified by (3-glycidyl propoxy) trimethoxysilane, and the organosilicon-modified acrylate emulsion is obtained by prepolymerization and emulsion polymerization of 3-(trimethoxysilyl) propyl methacrylate with acrylic acid, butyl acrylate, and methyl methacrylate monomers.

2. The scrub-resistant inorganic coating emulsion composition according to claim 1, characterized in that , the water-based epoxy resin is an aqueous dispersion of bisphenol A epoxy resin.

3. The scrub-resistant inorganic coating emulsion composition according to claim 1, characterized in that , the polyisocyanate crosslinking agent is water-dispersible hexamethylene diisocyanate trimer.

4. The scrub-resistant inorganic coating emulsion composition according to claim 1, characterized in that , the organic bentonite is bentonite modified by quaternary ammonium salt.

5. The scrub-resistant inorganic coating emulsion composition according to claim 1, characterized in that , the titanate coupling agent is isopropoxy tris(ethylenediamino-N-ethoxy) titanate.

6. A method for preparing the scrub-resistant inorganic coating emulsion composition according to any one of claims 1 to 5, characterized in that , including the following steps: (1) (3-glycidylpropoxy)trimethoxysilane and nano-silica were mixed in ethanol and reacted at 60-70°C for 4-6 hours to obtain modified nano-silica; (2) Prepolymerizing 3-(trimethoxysilyl)propyl methacrylate with acrylic acid, butyl acrylate, and methyl methacrylate monomers, and then performing emulsion polymerization to obtain a silicone-modified acrylate emulsion; (3) Dispersing the modified nano-silica obtained in step (1) in deionized water and ultrasonically dispersing for 30 minutes; (4) adding the silicone-modified acrylate emulsion, water-based epoxy resin, and organic bentonite obtained in step (2) to the dispersion obtained in step (3) in sequence and stirring evenly; (5) Add titanate coupling agent to the mixture obtained in step (4) and continue stirring for 30 minutes; (6) adding a polyisocyanate crosslinking agent and a functional additive to the mixture obtained in step (5) and stirring uniformly; (7) The mixture obtained in step (6) is processed by a high-pressure homogenizer to obtain a final coating emulsion composition.

7. The preparation method according to claim 6, characterized in that In step (2), the mass ratio of the total mass of acrylic acid, butyl acrylate, and methyl methacrylate to 3-(trimethoxysilyl)propyl methacrylate is 95:5 to 85:

15.

8. The preparation method according to claim 6, characterized in that In step (7), the pressure of the high-pressure homogenizer is 50-150 MPa, and the homogenization time is 10-30 minutes.