Preparation method of super-weather-resistant inorganic-organic hybrid water-based paint

Abstract

The invention discloses a preparation method of a super-weather-resistant inorganic-organic hybrid water-based paint, and relates to the technical field of paints.The preparation method comprises the following steps that an inorganic precursor material and deionized water are mixed, pH is adjusted, and an inorganic precursor solution is obtained; mixing an organic polymer monomer, deionized water and a catalyst, and carrying out heating polymerization reaction to obtain a polymer emulsion; mixing and dispersing the inorganic precursor solution, a polymer emulsion and an auxiliary agent to obtain the super-weather-resistant inorganic-organic hybrid water-based paint; the inorganic precursor material is a mixture of sodium silicate, sodium aluminate and tetrabutyl titanate in a mass ratio of (2-4): (1-3): (0.5-1.5); the organic polymer monomer is a mixture of acrylic acid, methyl methacrylate, styrene and acrylamide in a mass ratio of (4-5): (2-4): 2: (0.5-1.5). The coating prepared by the method is environment-friendly and good in weather resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and in particular to a method for preparing a super-weather-resistant inorganic-organic hybrid water-based coating. Background Art

[0002] With growing global environmental awareness and stricter regulations on volatile organic compound (VOC) emissions in various countries, water-based coatings, with their water-based dispersion medium and low VOC emissions, have become a key alternative to traditional solvent-based coatings. Water-based coatings dominate the architectural sector and are gradually penetrating into high-value-added applications such as automotive, furniture, and industrial corrosion protection.

[0003] Water-based coatings include water-soluble coatings, water-dilutable coatings, and water-dispersible coatings. Water-soluble coatings use water-soluble resins as film-forming materials, typified by polyvinyl alcohol and its various modifications. Other coatings include water-soluble alkyd resins, water-soluble epoxy resins, and inorganic polymer water-based resins. Water-dilutable coatings use post-emulsified emulsions as film-forming materials. Solvent-based resins are dissolved in organic solvents, and then, with the help of an emulsifier, the resins are dispersed in water through vigorous mechanical stirring to form an emulsion, known as a post-emulsified emulsion. This resulting coating can be diluted with water during construction. Water-dispersible coatings primarily use synthetic resin emulsions as film-forming materials.

[0004] While existing water-based coatings offer advantages such as environmental friendliness and ease of cleaning, they suffer from inadequate weather resistance, particularly in harsh environments such as those exposed to ultraviolet radiation, temperature fluctuations, and humidity fluctuations. Therefore, developing a water-based coating with excellent weather resistance is of great practical value. Summary of the Invention

[0005] The technical problem to be solved by the present invention is: in view of the shortcomings of the existing technology, a method for preparing a super weather-resistant inorganic-organic hybrid water-based coating is provided, and the coating prepared by the method is environmentally friendly and has good weather resistance.

[0006] In order to solve the above technical problems, the technical solution of the present invention is:

[0007] A method for preparing a super-weather-resistant inorganic-organic hybrid water-based coating comprises the following steps:

[0008] Mixing the inorganic precursor material with deionized water and adjusting the pH to obtain an inorganic precursor solution;

[0009] Mixing organic polymer monomers, deionized water, and a catalyst, heating and performing polymerization reaction to obtain a polymer emulsion;

[0010] The inorganic precursor solution, polymer emulsion and additives are mixed and dispersed to obtain a super-weather-resistant inorganic-organic hybrid water-based coating;

[0011] The inorganic precursor material is a mixture of sodium silicate, sodium aluminate and tetrabutyl titanate, and the mass ratio of the three is (2-4): (1-3): (0.5-1.5); the organic polymer monomer is a mixture of acrylic acid, methyl methacrylate, styrene and acrylamide, and the mass ratio of the four is (4-5): (2-4): 2: (0.5-1.5).

[0012] The water-based coating of the present invention is produced through inorganic-organic hybridization. An inorganic precursor solution is prepared by hydrolyzing sodium silicate, sodium aluminate, and tetrabutyl titanate under acidic conditions. The tetrabutyl titanate is hydrolyzed to produce nano-titanium dioxide, which has a high specific surface area and photocatalytic activity, can absorb ultraviolet light, and decompose organic pollutants through hole-electron pairs generated by electron transitions. Simultaneously, the hydroxyl groups (-OH) on the TiO2 surface form chemical bonds with the carboxyl groups (-COOH) in the polymer, enhancing interfacial bonding and thus improving the coating's weather resistance. The hydrolysis of sodium silicate and sodium aluminate produces a double-network gel composed of silica sol and aluminum sol, which blocks oxygen and moisture penetration, retards polymer oxidation and hydrolysis, and enhances the coating's durability in harsh environments.

[0013] The present invention adopts acrylic acid, methyl methacrylate, styrene and acrylamide as polymer monomers. Acrylic acid can provide carboxyl groups, which can form hydrogen bonds or ionic bonds with the surface of the substrate to improve the adhesion of the coating; at the same time, it can form hydrogen bonds or ionic bonds with metal ions (such as Al) in the inorganic precursor solution. 3+ 、Ti 4+ ) undergo coordination cross-linking to improve interfacial bonding strength; styrene and methyl methacrylate provide rigid chain segments to improve the hardness and scratch resistance of the coating; and the ester group of methyl methacrylate has good hydrolysis resistance, which can delay coating aging and thereby improve the weather resistance and stability of the coating.

[0014] Preferably, hydrochloric acid is used to adjust the pH of the solution to 7-8 during the preparation of the inorganic precursor solution.

[0015] Preferably, the preparation of the inorganic precursor solution also includes the step of adding an organically modified montmorillonite / hydrotalcite composite material, wherein the amount of the organically modified montmorillonite / hydrotalcite composite material added is 20-30 wt% of the mass of the inorganic precursor material. Specifically, the inorganic precursor material is mixed with deionized water, and the pH is adjusted, the organically modified montmorillonite / hydrotalcite composite material is added, and ultrasonic treatment is performed at room temperature to obtain the inorganic precursor solution.

[0016] Preferably, the method for preparing the organically modified montmorillonite / hydrotalcite composite material comprises the following steps:

[0017] (1) adding sodium montmorillonite, magnesium aluminum hydrotalcite material, and hexadecyltrimethylammonium bromide to an ethanol solution, adjusting the pH of the system to 3-4, and ultrasonically treating the mixture to obtain a mixed solution;

[0018] (2) heating the mixed solution and stirring the mixture for reaction. After the reaction is completed, centrifuging the reaction solution, and drying the centrifugal sediment to obtain a pre-modified composite material;

[0019] (3) The pre-modified composite material is dispersed in deionized water, lysine is added, ultrasonic treatment is performed once, and then glutamic acid is added to adjust the pH of the system to 6-7, and a reaction is carried out. After the reaction is completed, the reaction solution is centrifuged, and the centrifugal precipitate is mixed with a silane hydrolyzate to carry out a secondary reaction. After the reaction is completed, the reaction solution is centrifuged, and the centrifugal precipitate is mixed with an ethanol solution of an aluminate coupling agent to carry out a tertiary reaction. After the reaction solution is cooled to room temperature, the reaction solution is centrifuged, and the centrifugal precipitate is dried to obtain an organically modified montmorillonite / hydrotalcite composite material.

[0020] The inorganic precursor solution of the present invention also contains an organically modified montmorillonite / hydrotalcite composite material, which serves as a nano-reinforcement phase and is dispersed in the inorganic sol. It inhibits crack propagation through physical barrier and chemical bonding, thereby improving the mechanical strength and corrosion resistance of the coating.

[0021] Both sodium montmorillonite and magnesium aluminum hydrotalcite are layered inorganic materials with high specific surface area and ion exchange capacity, which can effectively improve the performance of coatings. The present invention forms an organic layered structure through the intercalation of hexadecyltrimethylammonium bromide to obtain a pre-modified composite material.

[0022] In order to better improve the performance of the pre-modified composite material and its compatibility with the coating, the present invention uses amino acids, silane coupling agents and aluminate coupling agents to perform multiple modifications on the pre-modified composite material. First, lysine and glutamic acid are compounded, and the amino and carboxyl groups in the amino acids can react with active groups such as hydroxyl groups on the surface of the pre-modified composite material to form a cross-linked network, thereby improving the interfacial bonding strength and dispersibility; then, a silane hydrolyzate of KH560 and KH550 is used for further modification, and the silanol groups generated by silane hydrolysis react with active groups such as hydroxyl groups (-OH) on the surface of the material to form chemical bonds through condensation reactions, thereby realizing the organic functionalization of the inorganic phase; and the further treatment with the aluminate coupling agent can introduce aluminate groups, thereby further enhancing the compatibility of the inorganic material with the organic matrix.

[0023] Preferably, in step (1), the mass ratio of sodium montmorillonite, magnesium aluminum hydrotalcite material, and hexadecyltrimethylbromide is 1:1:(0.1-0.3), and the ultrasonic treatment conditions are 300-600W and the time is 20-30min.

[0024] Preferably, in step (2), the conditions for the heating and stirring reaction are: stirring speed 800-1300 rpm, temperature 65-75° C., and time 12-24 h.

[0025] Preferably, in step (3), the mass ratio of glutamic acid to lysine is 1:1, the total amount of glutamic acid and lysine added is 15-20wt% of the mass of the pre-modified composite material, the temperature of the primary reaction is 55-65°C, and the time is 5-7h.

[0026] Preferably, the silane hydrolyzate is prepared by adding aminosilane and epoxysilane to an ethanol solution and hydrolyzing them, the aminosilane is KH550, the epoxysilane is KH560, the volume ratio of ethanol to deionized water in the ethanol solution is 9:1, the volume ratio of the aminosilane, epoxysilane and ethanol solution is (0.06-0.0.1): (0.06-0.1): 2, the hydrolysis temperature is room temperature, the pH is 4-5, and the time is 30-60 min.

[0027] Preferably, the solid-liquid ratio during the secondary reaction is 1:(12-17), the temperature is 65-75° C., and the time is 3-5 h.

[0028] Preferably, the concentration of the aluminate coupling agent in the ethanol solution of the aluminate coupling agent is 2-3 wt %, the solid-liquid ratio during the three reactions is 1:10, the reaction temperature is 57-60° C., and the reaction time is 1-2 h.

[0029] Preferably, during the preparation of the polymer emulsion, the catalyst is a Ziegler-Natta catalyst, and the catalyst accounts for 1-3 wt% of the total amount of organic polymerization monomers.

[0030] Preferably, the reaction temperature during the preparation of the polymer emulsion is 75-85° C., and the reaction time is 3-5 h.

[0031] In the preparation of the polymer emulsion, acrylic acid, methyl methacrylate, styrene, and acrylamide are polymerized as monomers to form a copolymer emulsion through free radical polymerization. The carboxyl groups in the polymer react with the hydroxyl groups or silane coupling agents in the inorganic phase to form an organic-inorganic crosslinked network.

[0032] Preferably, when the inorganic precursor solution and the organic polymer emulsion are mixed, the volume ratio of the inorganic precursor solution to the organic polymer emulsion is 1:(1-2).

[0033] Preferably, the dispersant is a polycarboxylate dispersant, the defoaming agent is a polyether defoaming agent, and the cross-linking agent is an isocyanate cross-linking agent.

[0034] Preferably, the volume of the dispersant is 0.5-1.5% of the total volume of the reaction solution, the volume of the defoaming agent is 0.3-0.6% of the total volume of the reaction solution, and the volume of the cross-linking agent is 1-3% of the total volume of the reaction solution.

[0035] Due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0036] 1. The water-based coating of the present invention is produced by hybridizing an inorganic precursor solution with a polymer emulsion under certain conditions. The inorganic precursor condenses to form a three-dimensional network that interpenetrates with the chain segments of the polymer emulsion, forming a dual continuous phase. The resulting water-based coating combines inorganic rigidity with organic toughness. Specifically, the inorganic phase is internally connected by functional bonds to form a stable network. Groups such as carboxyl and amino groups in the polymer emulsion bind to -OH groups on the inorganic surface through hydrogen bonds or coordination bonds, reducing phase separation and improving interfacial strength.

[0037] 2. The inorganic material of this invention is a hydrolyzed mixture of sodium silicate, sodium aluminate, and tetrabutyl titanate, combined with an organically modified montmorillonite / hydrotalcite composite material. These inorganic materials improve the coating's mechanical strength, heat resistance, and UV shielding and barrier properties, while the organic polymer provides flexibility, film-forming properties, and adhesion. This water-based coating reduces VOC emissions and is more environmentally friendly. DETAILED DESCRIPTION

[0038] In order to more clearly understand the above-mentioned objectives, features and advantages of the present invention, the scheme of the present invention will be further described below. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features therein can be combined with each other.

[0039] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present invention, rather than all the embodiments.

[0040] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the present invention.

[0041] In the following examples and comparative examples, sodium montmorillonite with a cation exchange capacity of 1 mmol / g was purchased from Zhejiang Fenghong Clay Chemical Co., Ltd.; magnesium-aluminum hydrotalcite was purchased from Shanghai Hongzhuang Chemical Technology Co., Ltd. The polyether defoamer was polyether defoamer WX-103, and the isocyanate dispersant was tetramethylxylylene diisocyanate.

[0042] Unless otherwise specified, other raw materials are commercially available; other conditions are conventional technical conditions in the art unless otherwise specified.

[0043] Example 1

[0044] A method for preparing a super-weather-resistant inorganic-organic hybrid water-based coating comprises the following steps:

[0045] (1) 1 g of sodium montmorillonite, 1 g of magnesium aluminum hydrotalcite, and 0.1 g of hexadecyltrimethylammonium bromide were added to 100 ml of ethanol solution (the volume ratio of ethanol to deionized water was 9:1), the pH of the system was adjusted to 3, and ultrasonic treatment was performed at 400 W for 20 min to obtain a mixed solution;

[0046] (2) stirring the mixture at 800 rpm and heating to 70° C. for 24 h. After the reaction, centrifuging the reaction solution, and drying the centrifugal precipitate to obtain a pre-modified composite material;

[0047] (3) KH550, KH560 and 50 ml of ethanol solution (the volume ratio of ethanol to deionized water is 9:1) are mixed in a volume ratio of 0.06:0.06:2, the pH of the system is adjusted to 4, and hydrolyzed at room temperature for 30 min to obtain a silane hydrolyzate;

[0048] (4) 1 g of the above-mentioned pre-modified composite material was dispersed in 50 ml of deionized water, 0.1 g of lysine was added, and ultrasonic treatment was performed at 500 W for 30 min. Then, 0.1 g of glutamic acid was added, and the pH of the system was adjusted to 6. The reaction was carried out at 60°C for 5 h. After the reaction, the reaction solution was centrifuged, and the centrifugal precipitate was mixed with the silane hydrolyzate to control the solid-liquid ratio to 1:12. The reaction was carried out at 70°C for 3 h. After the reaction was completed, the reaction solution was centrifuged, and the centrifugal precipitate was mixed with an ethanol solution of an aluminate coupling agent (the concentration of the aluminate coupling agent was 2 wt%) to control the solid-liquid ratio to 1:10. The reaction was carried out at 57°C for 2 h. After the reaction solution was cooled to room temperature, the reaction solution was centrifuged, and the centrifugal precipitate was dried to obtain an organically modified montmorillonite / hydrotalcite composite material.

[0049] (5) 3 g of sodium silicate, 2 g of sodium aluminate, and 1 g of tetrabutyl titanate were mixed with 50 ml of deionized water, and the pH of the system was adjusted to 7 with hydrochloric acid. Then, an organically modified montmorillonite / hydrotalcite composite material (20 wt % of the total amount of sodium silicate, sodium aluminate, and tetrabutyl titanate) was added, and ultrasonic treatment was performed at 500 W for 30 min to obtain an inorganic precursor solution;

[0050] (6) 4 g of acrylic acid, 3 g of methyl methacrylate, 2 g of styrene, and 1 g of acrylamide were mixed, 50 ml of deionized water and a Ziegler-Natta catalyst (the amount added was 2 wt% of the total amount of acrylic acid, methyl methacrylate, styrene, and acrylamide) were added, and the mixture was heated to 80° C. under nitrogen protection and polymerized for 4 h to obtain a polymer emulsion;

[0051] (7) The above-mentioned inorganic precursor solution and polymer emulsion are mixed in a volume ratio of 1:1, and a polycarboxylate dispersant (accounting for 1% of the total volume of the reaction liquid) and a polyether defoamer (accounting for 0.5% of the total volume of the reaction liquid) are added. After stirring evenly, an isocyanate crosslinker (accounting for 2% of the total volume of the reaction liquid) is added, and stirring is continued for 2 hours to obtain a super weather-resistant inorganic-organic hybrid water-based coating.

[0052] Example 2

[0053] A method for preparing a super-weather-resistant inorganic-organic hybrid water-based coating comprises the following steps:

[0054] (1) 1 g of sodium montmorillonite, 1 g of magnesium aluminum hydrotalcite, and 0.15 g of hexadecyltrimethylammonium bromide were added to 100 ml of ethanol solution (the volume ratio of ethanol to deionized water was 9:1), the pH of the system was adjusted to 4, and ultrasonic treatment was performed at 500 W for 30 min to obtain a mixed solution;

[0055] (2) stirring the mixture at 900 rpm and heating to 70° C. for 24 h. After the reaction, centrifuging the reaction solution, and drying the centrifugal precipitate to obtain a pre-modified composite material;

[0056] (3) KH550, KH560 and 50 ml of ethanol solution (the volume ratio of ethanol to deionized water is 9:1) are mixed in a volume ratio of 0.07:0.07:2, the pH of the system is adjusted to 5, and hydrolyzed at room temperature for 40 min to obtain a silane hydrolyzate;

[0057] (4) 1 g of the above-mentioned pre-modified composite material was dispersed in 50 ml of deionized water, 0.1 g of lysine was added, and ultrasonic treatment was performed at 500 W for 30 min. Then, 0.1 g of glutamic acid was added, and the pH of the system was adjusted to 7. The reaction was carried out at 60 ° C for 6 h. After the reaction, the reaction solution was centrifuged, and the centrifugal precipitate was mixed with the silane hydrolyzate to control the solid-liquid ratio to 1:13. The reaction was carried out at 70 ° C for 4 h. After the reaction was completed, the reaction solution was centrifuged, and the centrifugal precipitate was mixed with an ethanol solution of an aluminate coupling agent (the concentration of the aluminate coupling agent was 4 wt%) to control the solid-liquid ratio to 1:10. The reaction was carried out at 58 ° C for 2 h. After the reaction solution was cooled to room temperature, the reaction solution was centrifuged, and the centrifugal precipitate was dried to obtain an organically modified montmorillonite / hydrotalcite composite material;

[0058] (5) 3 g of sodium silicate, 2 g of sodium aluminate, and 1.5 g of tetrabutyl titanate were mixed with 50 ml of deionized water, and the pH of the system was adjusted to 8 with hydrochloric acid. Then, an organically modified montmorillonite / hydrotalcite composite material (30 wt % of the total amount of sodium silicate, sodium aluminate, and tetrabutyl titanate) was added, and ultrasonic treatment was performed at 500 W for 30 min to obtain an inorganic precursor solution;

[0059] (6) 4 g of acrylic acid, 4 g of methyl methacrylate, 2 g of styrene, and 1 g of acrylamide were mixed, 50 ml of deionized water and a Ziegler-Natta catalyst (the amount added was 2 wt% of the total amount of acrylic acid, methyl methacrylate, styrene, and acrylamide) were added, and the mixture was heated to 80° C. under nitrogen protection and polymerized for 4 h to obtain a polymer emulsion;

[0060] (7) The above-mentioned inorganic precursor solution and polymer emulsion are mixed in a volume ratio of 1:1, and a polycarboxylate dispersant (accounting for 1% of the total volume of the reaction liquid) and a polyether defoamer (accounting for 0.5% of the total volume of the reaction liquid) are added. After stirring evenly, an isocyanate crosslinker (accounting for 2% of the total volume of the reaction liquid) is added, and stirring is continued for 2 hours to obtain a super weather-resistant inorganic-organic hybrid water-based coating.

[0061] Example 3

[0062] A method for preparing a super-weather-resistant inorganic-organic hybrid water-based coating comprises the following steps:

[0063] (1) 1 g of sodium montmorillonite, 1 g of magnesium aluminum hydrotalcite, and 0.2 g of hexadecyltrimethylammonium bromide were added to 100 ml of ethanol solution (the volume ratio of ethanol to deionized water was 9:1), the pH of the system was adjusted to 4, and ultrasonic treatment was performed at 500 W for 30 min to obtain a mixed solution;

[0064] (2) stirring the mixture at 1100 rpm and heating to 70° C. for 24 h. After the reaction, centrifuging the reaction solution, and drying the centrifugal precipitate to obtain a pre-modified composite material;

[0065] (3) KH550, KH560 and 50 ml of ethanol solution (the volume ratio of ethanol to deionized water is 9:1) are mixed in a volume ratio of 0.08:0.08:2, the pH of the system is adjusted to 5, and hydrolyzed at room temperature for 50 min to obtain a silane hydrolyzate;

[0066] (4) 1 g of the above-mentioned pre-modified composite material was dispersed in 50 ml of deionized water, 0.1 g of lysine was added, and ultrasonic treatment was performed at 500 W for 30 min. Then, 0.1 g of glutamic acid was added, and the pH of the system was adjusted to 7. The reaction was carried out at 60° C. for 7 h. After the reaction, the reaction solution was centrifuged, and the centrifugal precipitate was mixed with the silane hydrolyzate to control the solid-liquid ratio to 1:14. The reaction was carried out at 70° C. for 5 h. After the reaction was completed, the reaction solution was centrifuged, and the centrifugal precipitate was mixed with an ethanol solution of an aluminate coupling agent (the concentration of the aluminate coupling agent was 2.5 wt%) to control the solid-liquid ratio to 1:10. The reaction was carried out at 59° C. for 1.5 h. After the reaction solution was cooled to room temperature, the reaction solution was centrifuged, and the centrifugal precipitate was dried to obtain an organically modified montmorillonite / hydrotalcite composite material.

[0067] (5) 4 g of sodium silicate, 3 g of sodium aluminate, and 1 g of tetrabutyl titanate were mixed with 50 ml of deionized water, and the pH of the system was adjusted to 7 with hydrochloric acid. Then, an organically modified montmorillonite / hydrotalcite composite material (20 wt % of the total amount of sodium silicate, sodium aluminate, and tetrabutyl titanate) was added, and ultrasonic treatment was performed at 500 W for 30 min to obtain an inorganic precursor solution;

[0068] (6) 5 g of acrylic acid, 3 g of methyl methacrylate, 2 g of styrene, and 1 g of acrylamide were mixed, 50 ml of deionized water and a Ziegler-Natta catalyst (added in an amount of 2 wt% of the total amount of acrylic acid, methyl methacrylate, styrene, and acrylamide) were added, and the mixture was heated to 80° C. under nitrogen protection and polymerized for 4 h to obtain a polymer emulsion;

[0069] (7) The above-mentioned inorganic precursor solution and polymer emulsion are mixed in a volume ratio of 1:1, and a polycarboxylate dispersant (accounting for 1% of the total volume of the reaction liquid) and a polyether defoamer (accounting for 0.5% of the total volume of the reaction liquid) are added. After stirring evenly, an isocyanate crosslinker (accounting for 2% of the total volume of the reaction liquid) is added, and stirring is continued for 2 hours to obtain a super weather-resistant inorganic-organic hybrid water-based coating.

[0070] Example 4

[0071] A method for preparing a super-weather-resistant inorganic-organic hybrid water-based coating comprises the following steps:

[0072] (1) 1 g of sodium montmorillonite, 1 g of magnesium aluminum hydrotalcite, and 0.3 g of hexadecyltrimethylammonium bromide were added to 100 ml of ethanol solution (the volume ratio of ethanol to deionized water was 9:1), the pH of the system was adjusted to 4, and ultrasonic treatment was performed at 600 W for 30 min to obtain a mixed solution;

[0073] (2) stirring the mixture at 1300 rpm and heating to 70° C. for 24 h. After the reaction, centrifuging the reaction solution, and drying the centrifugal precipitate to obtain a pre-modified composite material;

[0074] (3) KH550, KH560 and 50 ml of ethanol solution (the volume ratio of ethanol to deionized water is 9:1) are mixed in a volume ratio of 0.1:0.1:2, the pH of the system is adjusted to 5, and hydrolyzed at room temperature for 60 min to obtain a silane hydrolyzate;

[0075] (4) 1 g of the above-mentioned pre-modified composite material was dispersed in 50 ml of deionized water, 0.1 g of lysine was added, and ultrasonic treatment was performed at 500 W for 30 min. Then, 0.1 g of glutamic acid was added, and the pH of the system was adjusted to 7. The reaction was carried out at 60°C for 7 h. After the reaction, the reaction solution was centrifuged, and the centrifugal precipitate was mixed with the silane hydrolyzate to control the solid-liquid ratio to 1:17. The reaction was carried out at 70°C for 5 h. After the reaction was completed, the reaction solution was centrifuged, and the centrifugal precipitate was mixed with an ethanol solution of an aluminate coupling agent (the concentration of the aluminate coupling agent was 3 wt%) to control the solid-liquid ratio to 1:10. The reaction was carried out at 60°C for 2 h. After the reaction solution was cooled to room temperature, the reaction solution was centrifuged, and the centrifugal precipitate was dried to obtain an organically modified montmorillonite / hydrotalcite composite material.

[0076] (5) 4 g of sodium silicate, 3 g of sodium aluminate, and 1.5 g of tetrabutyl titanate were mixed with 50 ml of deionized water, and the pH of the system was adjusted to 8 with hydrochloric acid. Then, an organically modified montmorillonite / hydrotalcite composite material (30 wt % of the total amount of sodium silicate, sodium aluminate, and tetrabutyl titanate) was added, and ultrasonic treatment was performed at 500 W for 30 min to obtain an inorganic precursor solution;

[0077] (6) 5 g of acrylic acid, 4 g of methyl methacrylate, 2 g of styrene, and 1.5 g of acrylamide were mixed, 50 ml of deionized water and a Ziegler-Natta catalyst (the amount added was 2 wt% of the total amount of acrylic acid, methyl methacrylate, styrene, and acrylamide) were added, and the mixture was heated to 80° C. under nitrogen protection and polymerized for 4 h to obtain a polymer emulsion;

[0078] (7) The above-mentioned inorganic precursor solution and polymer emulsion are mixed in a volume ratio of 1:1, and a polycarboxylate dispersant (accounting for 1% of the total volume of the reaction liquid) and a polyether defoamer (accounting for 0.5% of the total volume of the reaction liquid) are added. After stirring evenly, an isocyanate crosslinker (accounting for 2% of the total volume of the reaction liquid) is added, and stirring is continued for 2 hours to obtain a super weather-resistant inorganic-organic hybrid water-based coating.

[0079] In order to verify that the water-based coating prepared by the method of the present invention has excellent performance, the following is a detailed description with reference to Example 1 and combined with multiple comparative examples.

[0080] Comparative Example 1

[0081] The difference between this comparative example and Example 1 is that steps (1) to (5) are not included, and no inorganic precursor solution is added in step (7). Other operations are the same as in Example 1 to obtain an organic water-based coating.

[0082] Comparative Example 2

[0083] The difference between this comparative example and Example 1 is that steps (1) to (4) are not included, and the organic modified montmorillonite / hydrotalcite composite material is not added in step (5). Other operations are the same as in Example 1.

[0084] Comparative Example 3

[0085] The difference between this comparative example and Example 1 is that steps (1) to (4) are not included, and in step (5), the organic modified montmorillonite / hydrotalcite composite material, sodium silicate and sodium aluminate are not added. Other operations are the same as in Example 1.

[0086] Comparative Example 4

[0087] The difference between this comparative example and Example 1 is that steps (1) to (4) are not included, and in step (5), the organic modified montmorillonite / hydrotalcite composite material, sodium silicate, and tetrabutyl titanate are not added. Other operations are the same as in Example 1.

[0088] Comparative Example 5

[0089] The difference between this comparative example and Example 1 is that steps (1) to (4) are not included, and in step (5), the organic modified montmorillonite / hydrotalcite composite material, sodium aluminate, and tetrabutyl titanate are not added. Other operations are the same as in Example 1.

[0090] Comparative Example 6

[0091] This comparative example differs from Example 1 in that steps (1) to (4) are not included, and in step (5), the organic modified montmorillonite / hydrotalcite composite material and sodium silicate are not added. The ratio of sodium aluminate and tetrabutyl titanate and other operations are the same as those in Example 1.

[0092] Comparative Example 7

[0093] This comparative example differs from Example 1 in that steps (1) to (4) are not included, and in step (5), the organic modified montmorillonite / hydrotalcite composite material and sodium aluminate are not added. The ratio of sodium silicate to tetrabutyl titanate and other operations are the same as those in Example 1.

[0094] Comparative Example 8

[0095] This comparative example differs from Example 1 in that steps (1) to (4) are not included, and in step (5), the organic modified montmorillonite / hydrotalcite composite material and tetrabutyl titanate are not added. The ratio of sodium aluminate to sodium silicate and other operations are the same as those in Example 1.

[0096] Comparative Example 9

[0097] The difference between this comparative example and Example 1 is that in step (1), an equal amount of sodium montmorillonite is used to replace the magnesium-aluminum hydrotalcite material, and the other operations are the same as those in Example 1.

[0098] Comparative Example 10

[0099] The difference between this comparative example and Example 1 is that in step (1), an equal amount of magnesium-aluminum hydrotalcite material is used instead of sodium-montmorillonite, and other operations are the same as in Example 1.

[0100] Comparative Example 11

[0101] The difference between this comparative example and Example 1 is that in step (4), an equal amount of lysine is used instead of glutamic acid, and the other operations are the same as those in Example 1.

[0102] Comparative Example 12

[0103] The difference between this comparative example and Example 1 is that in step (4), an equal amount of glutamic acid is used instead of lysine, and the other operations are the same as those in Example 1.

[0104] Comparative Example 13

[0105] The difference between this comparative example and Example 1 is that: step (4) is specifically as follows: 1 g of the above-mentioned pre-modified composite material is mixed with a silane hydrolyzate, the solid-liquid ratio is controlled to be 1:(12-17), and the reaction is carried out at 70°C for 3-5 hours. After the reaction is completed, the reaction solution is centrifuged, and the centrifugal precipitate is mixed with an ethanol solution of an aluminate coupling agent (the concentration of the aluminate coupling agent is 2-3wt%), the solid-liquid ratio is controlled to be 1:10, and the reaction is carried out at 57-60°C for 1-2 hours. After the reaction solution is cooled to room temperature, the reaction solution is centrifuged, and the centrifugal precipitate is dried to obtain an organically modified montmorillonite / hydrotalcite composite material. The other operations are the same as those in Example 1.

[0106] Comparative Example 14

[0107] The difference between this comparative example and Example 1 is that: step (4) is specifically as follows: 1 g of the above-mentioned pre-modified composite material is dispersed in 50 ml of deionized water, 0.1 g of lysine is added, ultrasonic treatment is carried out at 500 W for 30 min, and then 0.1 g of glutamic acid is added, the pH of the system is adjusted to 6-7, and the reaction is carried out at 60° C. for 5-7 h. After the reaction is completed, the reaction solution is centrifuged, and the centrifugal precipitate is mixed with an ethanol solution of an aluminate coupling agent (the concentration of the aluminate coupling agent is 2-3 wt%), the solid-liquid ratio is controlled to be 1:10, and the reaction is carried out at 57-60° C. for 1-2 h. After the reaction solution is cooled to room temperature, the reaction solution is centrifuged, and the centrifugal precipitate is dried to obtain an organically modified montmorillonite / hydrotalcite composite material. The other operations are the same as those in Example 1.

[0108] Comparative Example 15

[0109] The difference between this comparative example and Example 1 is that: step (4) is specifically as follows: 1 g of the above-mentioned pre-modified composite material is dispersed in 50 ml of deionized water, 0.1 g of lysine is added, ultrasonic treatment is carried out at 500 W for 30 min, and then 0.1 g of glutamic acid is added, the pH of the system is adjusted to 6-7, and the reaction is carried out at 60° C. for 5-7 h. After the reaction is completed, the reaction solution is centrifuged, and the centrifugal precipitate is mixed with the silane hydrolyzate, the solid-liquid ratio is controlled to be 1:(12-17), and the reaction is carried out at 70° C. for 3-5 h. After the reaction is completed, the reaction solution is centrifuged, and the centrifugal precipitate is dried to obtain an organically modified montmorillonite / hydrotalcite composite material. The other operations are the same as in Example 1.

[0110] Comparative Example 16

[0111] The difference between this comparative example and Example 1 is that step (4) is specifically as follows: 1 g of the above-mentioned pre-modified composite material is dispersed in 50 ml of deionized water, 0.1 g of lysine is added, ultrasonic treatment is carried out at 500 W for 30 min, and then 0.1 g of glutamic acid is added, the pH of the system is adjusted to 6-7, and the reaction is carried out at 60°C for 5-7 h. After the reaction is completed, the reaction solution is centrifuged, and the centrifugal precipitate is dried to obtain an organically modified montmorillonite / hydrotalcite composite material. The other operations are the same as in Example 1.

[0112] Comparative Example 17

[0113] The difference between this comparative example and Example 1 is that 1 g of the above-mentioned pre-modified composite material is mixed with the silane hydrolyzate, the solid-liquid ratio is controlled to be 1:(12-17), the reaction is carried out at 70°C for 3-5 hours, and after the reaction is completed, the reaction liquid is centrifuged, and the centrifugal precipitate is dried to obtain an organically modified montmorillonite / hydrotalcite composite material. The other operations are the same as in Example 1.

[0114] Comparative Example 18

[0115] The difference between this comparative example and Example 1 is that: 1 g of the above-mentioned pre-modified composite material is mixed with an ethanol solution of an aluminate coupling agent (the concentration of the aluminate coupling agent is 2-3 wt%), the solid-liquid ratio is controlled to be 1:10, and the reaction is carried out at 57-60°C for 1-2 hours. After the reaction solution is cooled to room temperature, the reaction solution is centrifuged, and the centrifugal precipitate is dried to obtain an organically modified montmorillonite / hydrotalcite composite material. The other operations are the same as in Example 1.

[0116] The coatings prepared in the above examples and comparative examples were subjected to performance tests. The test methods and test results are shown in Table 1.

[0117] 1. Weather resistance test

[0118] The coatings prepared in the examples and comparative examples were applied to glass plates with a coating thickness of 200 μm. After drying, the coatings were placed in a QUV accelerated aging tester and tested according to ASTM G155. The test conditions were: 340 nm wavelength, 0.89 W / m 2 The test was conducted in a cyclical manner, with each cycle lasting four hours, consisting of an 89-minute damp heat cycle and a 15-minute UV cycle. The coating condition after aging was then observed. The gloss at 60° was measured before and after aging in accordance with national standards GB / T 1766-1995 and GB9754-1988, and the gloss retention after aging was calculated.

[0119] Gloss retention (%) = (gloss before aging - gloss after aging) / gloss before aging × 100%. Surface gloss and color values were measured.

[0120] 2. Adhesion test

[0121] The cross-cut adhesion test was performed according to GB / T 9286-1998.

[0122] 3. Chemical resistance test

[0123] The coating was applied to a glass plate, dried, and then immersed in a 5 wt % hydrochloric acid solution and a 5 wt % sodium hydroxide solution, respectively. After 24 hours, the coating was taken out and no obvious change was observed on the surface, indicating that the coating had good chemical resistance.

[0124] The test results are shown in Table 1.

[0125] Table 1

[0126]

[0127]

[0128]

[0129] It can be seen from the above test results that, compared with the comparative example, the present invention uses an organically modified montmorillonite / hydrotalcite composite material and an inorganic precursor material prepared by hydrolysis of sodium silicate, sodium aluminate, and tetrabutyl titanate to modify the polymer emulsion, and the resulting water-based coating has good weather resistance, excellent adhesion, and excellent chemical resistance.

[0130] Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas, including the best mode, and also enable any technician in the field to practice the present invention, including making and using any device or system, and implementing any combined method. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention. The scope of patent protection of the present invention is defined by the claims and may include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements similar to the literal description of the claims, or if they include equivalent structural elements that are not substantially different from the literal description of the claims, then these other embodiments should also be included in the scope of the claims.

Claims

1. A method for preparing a super weather-resistant inorganic-organic hybrid water-based coating, characterized in that: The following steps are involved: Mixing the inorganic precursor material with deionized water and adjusting the pH to obtain an inorganic precursor solution; Mixing organic polymer monomers, deionized water, and a catalyst, heating and performing polymerization reaction to obtain a polymer emulsion; The inorganic precursor solution, polymer emulsion and additives are mixed and dispersed to obtain a super-weather-resistant inorganic-organic hybrid water-based coating; The inorganic precursor material is a mixture of sodium silicate, sodium aluminate and tetrabutyl titanate, and the mass ratio of the three is (2-4): (1-3): (0.5-1.5); the organic polymer monomer is a mixture of acrylic acid, methyl methacrylate, styrene and acrylamide, and the mass ratio of the four is (4-5): (2-4): 2: (0.5-1.5).

2. The method for preparing a super weather-resistant inorganic-organic hybrid water-based coating according to claim 1, wherein: In the preparation of the inorganic precursor solution, hydrochloric acid is used to adjust the pH of the solution to 7-8.

3. The method for preparing a super weather-resistant inorganic-organic hybrid water-based coating according to claim 1, wherein: The preparation of the inorganic precursor solution also includes the step of adding an organically modified montmorillonite / hydrotalcite composite material, wherein the amount of the organically modified montmorillonite / hydrotalcite composite material added is 20-30wt% of the mass of the inorganic precursor material. Specifically, the inorganic precursor material is mixed with deionized water, and the pH is adjusted. The organically modified montmorillonite / hydrotalcite composite material is added, and ultrasonic treatment is performed at room temperature to obtain the inorganic precursor solution.

4. The method for preparing a super weather-resistant inorganic-organic hybrid water-based coating according to claim 3, wherein: The preparation method of the organic modified montmorillonite / hydrotalcite composite material comprises the following steps: (1) adding sodium montmorillonite, magnesium aluminum hydrotalcite material, and hexadecyltrimethylammonium bromide in a mass ratio of 1:1:(0.1-0.3) to an ethanol solution, adjusting the pH of the system to 3-4, and ultrasonically treating at 300-600W for 20-30min to obtain a mixed solution; (2) stirring the mixture at a speed of 800-1300 rpm and heating it to 65-75° C. for 12-24 hours. After the reaction is completed, centrifuging the reaction solution, and drying the centrifugal precipitate to obtain a pre-modified composite material; (3) The pre-modified composite material is dispersed in deionized water, lysine is added, ultrasonic treatment is performed once, and then glutamic acid is added to adjust the pH of the system to 6-7, and a reaction is carried out. After the reaction is completed, the reaction solution is centrifuged, and the centrifugal precipitate is mixed with a silane hydrolyzate to carry out a secondary reaction. After the reaction is completed, the reaction solution is centrifuged, and the centrifugal precipitate is mixed with an ethanol solution of an aluminate coupling agent to carry out a tertiary reaction. After the reaction solution is cooled to room temperature, the reaction solution is centrifuged, and the centrifugal precipitate is dried to obtain an organically modified montmorillonite / hydrotalcite composite material.

5. The method for preparing a super weather-resistant inorganic-organic hybrid water-based coating according to claim 3, characterized in that: In step (3), the mass ratio of glutamic acid to lysine is 1:1, and the total amount of glutamic acid and lysine added is 15-20 wt% of the mass of the pre-modified composite material; The silane hydrolyzate is prepared by adding aminosilane and epoxysilane to an ethanol solution for hydrolysis, wherein the aminosilane is KH550, the epoxysilane is KH560, the volume ratio of ethanol to deionized water in the ethanol solution is 9:1, and the volume ratio of the aminosilane, epoxysilane, and ethanol solution is (0.06-0.0.1):(0.06-0.1):

2. The hydrolysis temperature is room temperature, the pH is 4-5, and the time is 30-60 minutes. The concentration of the aluminate coupling agent in the ethanol solution of the aluminate coupling agent is 2-3 wt %.

6. The method for preparing a super weather-resistant inorganic-organic hybrid water-based coating according to claim 3, characterized in that: The temperature of the first reaction is 55-65°C and the time is 5-7h; the solid-liquid ratio of the second reaction is 1:(12-17), the temperature is 65-75°C, and the time is 3-5h; the solid-liquid ratio of the third reaction is 1:10, the reaction temperature is 57-60°C, and the time is 1-2h.

7. The method for preparing a super weather-resistant inorganic-organic hybrid water-based coating according to claim 1, characterized in that: During the preparation of the polymer emulsion, the catalyst is a Ziegler-Natta catalyst, and the catalyst accounts for 1-3 wt% of the total amount of organic polymerization monomers.

8. The method for preparing a super weather-resistant inorganic-organic hybrid water-based coating according to claim 1, characterized in that: The reaction temperature during the preparation of the polymer emulsion is 75-85° C., and the reaction time is 3-5 hours.

9. The method for preparing a super weather-resistant inorganic-organic hybrid water-based coating according to claim 1, characterized in that: When the inorganic precursor solution and the organic polymer emulsion are mixed, the volume ratio of the inorganic precursor solution to the organic polymer emulsion is 1:(1-2).

10. The method for preparing a super weather-resistant inorganic-organic hybrid water-based coating according to claim 1, characterized in that: The dispersant is, the defoaming agent is, and the crosslinking agent is; preferably, the volume of the dispersant is 0.5-1.5% of the total volume of the reaction solution, the volume of the defoaming agent is 0.3-0.6% of the total volume of the reaction solution, and the volume of the crosslinking agent is 1-3% of the total volume of the reaction solution.

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