A waterproof and anti-corrosion two-component cyanocondensate composite coating and its preparation method

Abstract

The present invention belongs to the technical field of coatings, and specifically relates to a waterproof and anti-corrosion two-component cyanoacrylate composite coating and a preparation method thereof. The method comprises the following steps: preparation of anti-corrosion functionalized alcohol ether; dynamic hydrophobic migration microsphere filler; hydrophilic modification of isocyanate and blending of prepolymer. The present invention prepares dynamic hydrophobic migration microspheres and then adds them to the preparation process of the waterproof and anti-corrosion two-component cyanoacrylate composite coating. Not only does the composite coating have stable dispersibility and can form a uniform phase, but also, during the heating and curing process after coating, the hydrophobic components can be released and migrate to the surface of the coating, thereby forming a hydrophobic layer on the surface, improving the waterproof performance of the coating after film formation, and enabling the substances in the inner layer to react better, thereby enhancing the adhesion of the coating.

Description

Technical Field

[0001] The invention belongs to the technical field of coatings, and in particular relates to a waterproof and anti-corrosion two-component cyanocondensate composite coating and a preparation method thereof. Background Art

[0002] Cyanide prepolymer is a high molecular weight prepolymer with cyanate and isocyanate as reactive groups. It has excellent chemical corrosion resistance, high adhesion and low-temperature curing properties, and is widely used in the coating field. Traditional cyanide coating forms a polyurethane network through the gradual addition polymerization of isocyanate and polyol. Although the cured coating has certain waterproof and anti-corrosion properties, with its widespread application, higher requirements are placed on the performance of cyanide coating.

[0003] In order to prevent moisture in the air from penetrating into building materials, existing cyanide-curing coatings often add hydrophobic modifying materials such as talcum powder to the coatings, thereby providing better waterproof performance for the building materials when the coatings are formed. However, the hydrophobic modifying materials are usually evenly distributed inside the coating film layer and cannot be completely distributed on the surface of the substrate. The material utilization rate is low, and the cross-linking density of the polymer is often affected during film formation, resulting in a decrease in the mechanical properties of the film layer after film formation. Summary of the Invention

[0004] In order to solve the above technical defects, the present invention has developed a method for preparing a waterproof and anti-corrosion two-component cyanide coagulant composite coating. By preparing anti-corrosion functionalized alcohol ether and prepolymerizing toluene diisocyanate, and then blending it with dynamic hydrophobic migration microsphere filler and hydrophilic TDI curing agent, a cyanide coagulant composite coating with high stability, high adhesion and high tensile strength is prepared, and it has excellent waterproof and anti-corrosion properties.

[0005] A method for preparing a waterproof and anti-corrosion two-component cyanocondensate composite coating comprises the following steps:

[0006] S1: Preparation of anti-corrosion functionalized alcohol ethers

[0007] Pentaerythritol, cholesteryl chloride and pyridine are mixed and reacted at high temperature, and after impurity removal and dehydration, a single-arm substituted pentaerythritol ether is obtained, which is then reacted with triphenyl thiophosphate, anhydrous potassium carbonate and potassium iodide at high temperature, and a modified substituted alcohol ether is obtained after extraction, which is then modified with 2-chloromethylbenzimidazole to obtain an anti-corrosion functionalized alcohol ether.

[0008] S2: Dynamic hydrophobic migration microsphere filler

[0009] A carboxyl-functionalized copolymer is obtained by mixing N-vinyl pyrrolidone and itaconic acid, which is then mixed with octadecylamine to obtain a migration promoter. Cardanol glycidyl ether and liquid paraffin are co-melted, and the migration promoter and nano-cerium oxide are added. After high-speed shearing, the mixture is encapsulated with sodium alginate and CaCl2 to obtain a dynamic hydrophobic migration microsphere filler.

[0010] S3: Hydrophilic modification of isocyanate and blending of prepolymers

[0011] Toluene diisocyanate and 3-cyclohexylaminopropanesulfonic acid are dehydrated and heated for condensation reflux reaction to obtain a hydrophilic TDI curing agent, and then the anti-corrosion functionalized alcohol ether and toluene diisocyanate are co-heated for prepolymerization to obtain a prepolymer dispersion, and then dynamic hydrophobic migration microsphere filler, film-forming agent and hydrophilic TDI curing agent are added and mixed, and filtered and packaged to obtain a waterproof and anti-corrosion two-component cyanocondensate composite coating.

[0012] Furthermore, step S1 of preparing the anti-corrosion functionalized alcohol ether comprises the following steps:

[0013] S1.1: Pentaerythritol and cholesteryl chloride are placed in an autoclave at a molar ratio of 1:(1-1.5), 30-35 parts of pyridine are added, and nitrogen is introduced. The air in the autoclave is displaced, and the temperature is raised to 40-45°C. The reaction is stirred at 450-500 rpm for 10-12 hours, and the pyridine is recovered by vacuum distillation to obtain a reaction product. The reactant is extracted 3-4 times with saturated NaHCO3-ethyl acetate solution to obtain an organic phase. Anhydrous MgSO4 is added, stirred for 1-1.5 hours, and then filtered to obtain a single-arm substituted pentaerythritol ether.

[0014] S1.2: Under nitrogen, place 18-20 parts of triphenyl thiophosphate, 6-8 parts of anhydrous potassium carbonate, and 0.3-0.4 parts of potassium iodide in a container, add 160-200 parts of anhydrous acetonitrile, activate at 50-55°C for 25-30 minutes, then slowly add 80-100 parts of a single-arm substituted pentaerythritol ether, raise the temperature to 60-65°C, maintain the temperature for 10-12 hours, filter to remove salt, and extract to obtain a modified substituted alcohol ether;

[0015] S1.3: Take 10-12 parts of modified substituted alcohol ether and 15-20 parts of N,N-dimethylformamide and place them in a container. After stirring evenly, place it in an environment of 0-2°C. Slowly add 10-12 parts of 2-chloromethylbenzimidazole into the container, then heat it to 40-45°C and keep it warm for 8-10 hours. Place the mixture in the container in a dialysis bag and dialyze it with deionized water for 30-40 hours. Then, freeze-dry it to obtain an antiseptic functionalized alcohol ether.

[0016] Furthermore, step S2 of dynamically hydrophobic migrating microsphere fillers comprises the following steps:

[0017] S2.1: Place 20-25 parts of N-vinyl pyrrolidone and 6-8 parts of itaconic acid in a container, add 0.5-0.6 wt% of AIBN initiator, and react at 60-65°C for 1.5-2 hours to obtain a carboxyl-functionalized copolymer. Mix the carboxyl-functionalized copolymer with 3-5 parts of octadecylamine, add the mixture to 40-45 parts of N,N-dimethylformamide, and incubate at 120-130°C for 3.5-4 hours to obtain a migration promoter.

[0018] S2.2: Melt-mix 25-30 parts of cardanol glycidyl ether and 10-15 parts of liquid paraffin at 80-85°C, add 4-6 parts of a migration accelerator, stir evenly, then add 5-8 parts of nano-cerium oxide and 4-5 wt% of Tween-80, and shear the mixture at 2000-2500 rpm for 8-10 minutes to obtain a uniform emulsion;

[0019] S2.3: Add the uniform emulsion to 100-120 parts of a 1-2% sodium alginate solution, ultrasonically stir at a frequency of 30-35 kHz for 15-20 minutes, then add 60-80 parts of a 3-5% CaCl2 solution, stir at a speed of 300-400 rpm for 30-35 minutes, let it stand for 10-15 minutes, then add 50-60 parts of perfluorooctyltriethoxysilane / acetone solution and stir evenly, wherein the mass fraction of perfluorooctyltriethoxysilane is 14-16%, continue to stand for 25-30 minutes, and finally centrifuge at a speed of 6000-8000 rpm for 18-20 minutes, discard the upper layer of liquid and retain the lower layer of microcapsules, and place the microcapsules in an environment of -40°C to -35°C for freeze-drying for 6-8 hours to obtain dynamic hydrophobic migration microsphere fillers.

[0020] Furthermore, step S3 of hydrophilic modification of isocyanate and blending of prepolymer comprises the following steps:

[0021] S3.1: Add 5-6 wt% activated molecular sieves to toluene diisocyanate, stir well, and soak for 7-8 days. Store in a sealed container to obtain anhydrous toluene diisocyanate. Dry 3-cyclohexylaminopropanesulfonic acid in a vacuum oven to constant weight, cool to room temperature, and store in a dry environment to obtain anhydrous 3-cyclohexylaminopropanesulfonic acid.

[0022] S3.2: Mix 10-15 parts of anhydrous toluene diisocyanate and 4-5 parts of butyl acetate in a container equipped with a stirrer, a condenser, and a thermometer. Heat to 80-85°C under a nitrogen atmosphere. Then add 0.8-1 part of anhydrous 3-cyclohexylaminopropanesulfonic acid and 0.8-1 part of dimethylcyclohexylamine. Keep the mixture under reflux for 8-10 hours. Cool the mixture to obtain a hydrophilic TDI curing agent.

[0023] S3.3: Place the anti-corrosion functionalized alcohol ether in a container equipped with a stirrer, condenser, and thermometer, and heat to 80-85°C in a nitrogen atmosphere. Then, add toluene diisocyanate at an NCO-OH ratio of 1:(0.85-0.9). Keep the mixture warm for 3-4 hours. When the temperature drops to 35-40°C, add 25-30 wt% acetone, and cool naturally to room temperature to obtain a prepolymer dispersion.

[0024] S3.4: Place the prepolymer dispersion in a dry container, add 4-6wt% of dynamic hydrophobic migration microsphere filler and 3-5wt% of film-forming agent, and then add hydrophilic TDI curing agent according to the OH content in the prepolymer dispersion and the NCO-OH ratio of 1: (0.9-0.92). After stirring evenly, filter, measure and package to obtain a waterproof and anti-corrosion two-component cyanoacrylate composite coating.

[0025] Furthermore, in the saturated NaHCO 3 -ethyl acetate solution in step S1.1, the volume ratio of the saturated NaHCO 3 solution to ethyl acetate is 1:(2.5-3).

[0026] Furthermore, the extraction method in step S1.2 is supercritical CO2 extraction.

[0027] Furthermore, the molecular weight cut-off of the dialysis bag in step S1.3 is 1000-1200 Da.

[0028] Furthermore, in step S2.2, the particle size of the nano-cerium oxide is 30-50 nm.

[0029] Furthermore, the film-forming agent in step S3.4 is lauryl alcohol ester.

[0030] A waterproof and anti-corrosion two-component cyanide coagulant composite coating is prepared by the preparation method of the waterproof and anti-corrosion two-component cyanide coagulant composite coating.

[0031] The beneficial effects are: 1. The present invention prepares dynamic hydrophobic migration microspheres and then adds them to the preparation process of a waterproof and anti-corrosion two-component cyanide coagulant composite coating. Not only does the composite coating have stable dispersibility and can form a uniform phase, but also, during the heating and curing process after coating, it can release hydrophobic components to migrate to the surface of the coating, thereby forming a hydrophobic layer on the surface, improving the waterproof performance of the coating after film formation, and enabling the inner layer substances to react better, thereby enhancing the adhesion and mechanical properties of the coating.

[0032] 2. The present invention carries out a substitution reaction of pentaerythritol with cholesteryl chloride to obtain a single-arm substituted pentaerythritol ether, which is then modified in sequence with triphenyl thiophosphate and 2-chloromethylbenzimidazole to obtain an alcohol ether with anti-corrosion function. The polyurethane prepolymer is obtained by a stepwise addition polymerization reaction with toluene diisocyanate. After being made into a coating, it can provide excellent anti-corrosion performance after film formation and can also give the coating better stability.

[0033] 3. The present invention dehydrates toluene diisocyanate and 3-cyclohexylaminopropanesulfonic acid and then heats them with dimethylcyclohexylamine to perform a condensation reflux reaction. During this process, dimethylcyclohexylamine acts as a catalyst to accelerate the addition reaction of -NCO and -NH2, while neutralizing the sulfonic acid group and forming an ion pair with the -SO3H group of 3-cyclohexylaminopropanesulfonic acid to improve water solubility and storage stability. Then, under the action of dimethylcyclohexylamine, the -SO3H group is introduced. The obtained hydrophilic TDI curing agent has better hydrophilicity and stability, can enhance the stability and dispersibility of the entire composite coating system, and can form a film layer with high cross-linking density and better tensile strength during coating and curing. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 The present invention is a flow chart of a method for preparing a waterproof and anti-corrosion two-component cyanoacrylate composite coating used in an embodiment of the present invention. DETAILED DESCRIPTION

[0035] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the 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.

[0036] It should be noted that, unless otherwise specified, the parts in the following examples are expressed as parts by weight.

[0037] Example 1

[0038] A waterproof and anti-corrosion two-component cyanocondensation composite coating and its preparation method, such as Figure 1 As shown, the following steps are included:

[0039] S1: Preparation of anti-corrosion functionalized alcohol ethers

[0040] S1.1: Pentaerythritol and cholesteryl chloride were placed in an autoclave at a molar ratio of 1:1, 30 parts of pyridine were added, and nitrogen was introduced. The air in the autoclave was replaced, and the temperature was raised to 40°C. The reaction was stirred at 450 rpm for 10 hours, and the pyridine was recovered by distillation under reduced pressure to obtain a reaction product. The reactant was extracted three times with a saturated NaHCO3-ethyl acetate solution, wherein the volume ratio of the saturated NaHCO3 solution to ethyl acetate was 1:2.5, to obtain an organic phase. Anhydrous MgSO4 was added, stirred for 1 hour, and then filtered to obtain a single-arm substituted pentaerythritol ether.

[0041] S1.2: Under nitrogen, place 18 parts of triphenyl thiophosphate, 6 parts of anhydrous potassium carbonate, and 0.3 parts of potassium iodide in a container, add 160 parts of anhydrous acetonitrile, and activate at 50°C for 25 minutes. Then, slowly add 80 parts of a single-arm substituted pentaerythritol ether, raise the temperature to 60°C, and keep the temperature for 10 hours. After filtering to remove salt, perform supercritical CO2 extraction at 140 MPa and 45°C to obtain a modified substituted alcohol ether.

[0042] S1.3: Take 10 parts of modified substituted alcohol ether and 15 parts of N,N-dimethylformamide and place them in a container. Stir evenly and place it in a 0°C environment. Slowly add 10 parts of 2-chloromethylbenzimidazole into the container, then heat it to 40°C and keep it warm for 8 hours. The mixture in the container is placed in a dialysis bag with a molecular weight cutoff of 1000Da and dialyzed with deionized water for 30 hours. Then, freeze-dry it to obtain an antiseptic functionalized alcohol ether.

[0043] S2: Dynamic hydrophobic migration microsphere filler

[0044] S2.1: Place 20 parts of N-vinyl pyrrolidone and 6 parts of itaconic acid in a container, add 0.5 wt% of AIBN initiator, and react at 60°C for 1.5 hours to obtain a carboxyl-functionalized copolymer. Mix the carboxyl-functionalized copolymer with 3 parts of octadecylamine, add the mixture to 40 parts of N,N-dimethylformamide, and incubate at 120°C for 3.5 hours to obtain a migration promoter.

[0045] S2.2: Melt-mix 25 parts of cardanol glycidyl ether and 10 parts of liquid paraffin at 80°C, add 4 parts of a migration accelerator, stir until uniform, then add 5 parts of 30 nm nano-cerium oxide and 4 wt% of Tween-80, and shear the mixture at 2000 rpm for 8 minutes to obtain a uniform emulsion.

[0046] S2.3: Add the uniform emulsion to 100 parts of 1% sodium alginate solution, ultrasonically stir at a frequency of 30 kHz for 15 minutes, then add 60 parts of 3% CaCl2 solution, stir at a speed of 300 rpm for 30 minutes, let it stand for 10 minutes, add 50 parts of perfluorooctyltriethoxysilane / acetone solution and stir evenly, wherein the mass fraction of perfluorooctyltriethoxysilane is 14%, continue to stand for 25 minutes, and finally centrifuge at a speed of 6000 rpm for 18 minutes, discard the upper layer of liquid and retain the lower layer of microcapsules, and place the microcapsules in an environment of minus 40°C for freeze-drying for 6 hours to obtain dynamic hydrophobic migration microsphere fillers.

[0047] S3: Hydrophilic modification of isocyanate and blending of prepolymers

[0048] S3.1: Add 5 wt% activated molecular sieves to toluene diisocyanate, stir well, and soak for 7 days. Store in a sealed container to obtain anhydrous toluene diisocyanate. Dry 3-cyclohexylaminopropanesulfonic acid in a vacuum oven to constant weight, cool to room temperature, and store in a dry environment to obtain anhydrous 3-cyclohexylaminopropanesulfonic acid.

[0049] S3.2: 10 parts of anhydrous toluene diisocyanate and 4 parts of butyl acetate were mixed and added to a container equipped with a stirrer, a condenser, and a thermometer. The mixture was heated to 80°C under a nitrogen atmosphere. 0.8 parts of anhydrous 3-cyclohexylaminopropanesulfonic acid and 0.8 parts of dimethylcyclohexylamine were then added. The mixture was kept at reflux for 8 hours and cooled to obtain a hydrophilic TDI curing agent.

[0050] S3.3: Place the anti-corrosion functionalized alcohol ether in a container equipped with a stirrer, a condenser, and a thermometer, and heat to 80°C in a nitrogen atmosphere. Then, add toluene diisocyanate at an NCO-OH ratio of 1:0.85. Keep the mixture warm for 3 hours. When the temperature drops to 35°C, add 25 wt% acetone, and cool naturally to room temperature to obtain a prepolymer dispersion.

[0051] S3.4: Place the prepolymer dispersion in a dry container, add 4 wt% of dynamic hydrophobic migration microsphere filler and 3 wt% of dodecyl alcohol ester, and then add hydrophilic TDI curing agent according to the NCO-OH ratio of 1:0.9 based on the OH content in the prepolymer dispersion. After stirring evenly, filter, measure and package to obtain a waterproof and anti-corrosion two-component cyanoacrylate composite coating.

[0052] Example 2

[0053] A waterproof and anti-corrosion two-component cyanocondensation composite coating and its preparation method, such as Figure 1 As shown, the following steps are included:

[0054] S1: Preparation of anti-corrosion functionalized alcohol ethers

[0055] S1.1: Pentaerythritol and cholesteryl chloride were placed in an autoclave at a molar ratio of 1:1.5, 35 parts of pyridine were added, and nitrogen was introduced. The air in the autoclave was replaced, and the temperature was raised to 40°C. The reaction was stirred at 450 rpm for 10 hours, and the pyridine was recovered by distillation under reduced pressure to obtain a reaction product. The reactant was extracted three times with a saturated NaHCO3-ethyl acetate solution, wherein the volume ratio of the saturated NaHCO3 solution to ethyl acetate was 1:2.5, to obtain an organic phase. Anhydrous MgSO4 was added, stirred for 1 hour, and then filtered to obtain a single-arm substituted pentaerythritol ether.

[0056] S1.2: Under nitrogen, place 20 parts of triphenyl thiophosphate, 8 parts of anhydrous potassium carbonate, and 0.4 parts of potassium iodide in a container, add 200 parts of anhydrous acetonitrile, activate at 50°C for 25 minutes, then slowly add 100 parts of a single-arm substituted pentaerythritol ether, raise the temperature to 60°C, and keep it for 10 hours. After filtering to remove salt, perform supercritical CO2 extraction at 140 MPa and 45°C to obtain a modified substituted alcohol ether.

[0057] S1.3: Take 12 parts of modified substituted alcohol ether and 20 parts of N,N-dimethylformamide and place them in a container. After stirring evenly, place it in an environment of 0℃. Slowly add 12 parts of 2-chloromethylbenzimidazole into the container, then heat it to 40℃ and keep it warm for 8 hours. The mixture in the container is placed in a dialysis bag with a molecular weight cutoff of 1000Da and dialyzed with deionized water for 30 hours. Then, freeze-dry it to obtain an antiseptic functionalized alcohol ether.

[0058] S2: Dynamic hydrophobic migration microsphere filler

[0059] S2.1: Place 25 parts of N-vinyl pyrrolidone and 8 parts of itaconic acid in a container, add 0.6 wt% of AIBN initiator, and react at 60°C for 1.5 hours to obtain a carboxyl-functionalized copolymer. Mix the carboxyl-functionalized copolymer with 5 parts of octadecylamine, add the mixture to 45 parts of N,N-dimethylformamide, and incubate at 120°C for 3.5 hours to obtain a migration promoter.

[0060] S2.2: 30 parts of cardanol glycidyl ether and 15 parts of liquid paraffin were melt-mixed at 80°C, 6 parts of a migration accelerator were added, and the mixture was stirred uniformly. 8 parts of 30 nm nano-cerium oxide and 4 wt% of Tween-80 were added, and the mixture was sheared at 2000 rpm for 8 minutes to obtain a uniform emulsion.

[0061] S2.3: Add the uniform emulsion to 120 parts of 1% sodium alginate solution, ultrasonically stir at a frequency of 30 kHz for 15 minutes, then add 80 parts of 3% CaCl2 solution, stir at a speed of 300 rpm for 30 minutes, let it stand for 10 minutes, add 60 parts of perfluorooctyltriethoxysilane / acetone solution and stir evenly, wherein the mass fraction of perfluorooctyltriethoxysilane is 14%, continue to stand for 25 minutes, and finally centrifuge at a speed of 6000 rpm for 18 minutes, discard the upper layer of liquid and retain the lower layer of microcapsules, and place the microcapsules in an environment of minus 40°C for freeze-drying for 6 hours to obtain dynamic hydrophobic migration microsphere fillers.

[0062] S3: Hydrophilic modification of isocyanate and blending of prepolymers

[0063] S3.1: Add 6 wt% activated molecular sieves to toluene diisocyanate, stir well, and soak for 7 days. Store in a sealed container to obtain anhydrous toluene diisocyanate. Dry 3-cyclohexylaminopropanesulfonic acid in a vacuum oven to constant weight, cool to room temperature, and store in a dry environment to obtain anhydrous 3-cyclohexylaminopropanesulfonic acid.

[0064] S3.2: 15 parts of anhydrous toluene diisocyanate and 5 parts of butyl acetate were mixed and added to a container equipped with a stirrer, a condenser, and a thermometer. The mixture was heated to 80°C under a nitrogen atmosphere. 1 part of anhydrous 3-cyclohexylaminopropanesulfonic acid and 1 part of dimethylcyclohexylamine were then added. The mixture was kept at reflux for 8 hours and cooled to obtain a hydrophilic TDI curing agent.

[0065] S3.3: Place the anti-corrosion functionalized alcohol ether in a container equipped with a stirrer, a condenser, and a thermometer, and heat to 80°C in a nitrogen atmosphere. Then, add toluene diisocyanate at an NCO-OH ratio of 1:0.9. Keep the mixture warm for 3 hours. When the temperature drops to 35°C, add 25 wt% acetone, and cool naturally to room temperature to obtain a prepolymer dispersion.

[0066] S3.4: Place the prepolymer dispersion in a dry container, add 6wt% of dynamic hydrophobic migration microsphere filler and 5wt% of dodecyl alcohol ester, and then add hydrophilic TDI curing agent according to the OH content in the prepolymer dispersion and the NCO-OH ratio of 1:0.92. After stirring evenly, filter, measure and package to obtain a waterproof and anti-corrosion two-component cyanoacrylate composite coating.

[0067] Example 3

[0068] A waterproof and anti-corrosion two-component cyanocondensation composite coating and its preparation method, such as Figure 1 As shown, the following steps are included:

[0069] S1: Preparation of anti-corrosion functionalized alcohol ethers

[0070] S1.1: Pentaerythritol and cholesteryl chloride were placed in an autoclave at a molar ratio of 1:1, 30 parts of pyridine were added, and nitrogen was introduced. The air in the autoclave was replaced, and the temperature was raised to 45°C. The reaction was stirred at 500 rpm for 12 hours, and the pyridine was recovered by distillation under reduced pressure to obtain a reaction product. The reactant was extracted four times with a saturated NaHCO3-ethyl acetate solution, wherein the volume ratio of the saturated NaHCO3 solution to ethyl acetate was 1:2.5, to obtain an organic phase. Anhydrous MgSO4 was added, stirred for 1.5 hours, and then filtered to obtain a single-arm substituted pentaerythritol ether.

[0071] S1.2: Under nitrogen, place 18 parts of triphenyl thiophosphate, 6 parts of anhydrous potassium carbonate, and 0.3 parts of potassium iodide in a container, add 160 parts of anhydrous acetonitrile, activate at 55°C for 30 minutes, then slowly add 80 parts of a single-arm substituted pentaerythritol ether, raise the temperature to 65°C, and keep it for 12 hours. After filtering to remove salt, perform supercritical CO2 extraction at 150 MPa and 50°C to obtain a modified substituted alcohol ether.

[0072] S1.3: Take 10 parts of modified substituted alcohol ether and 15 parts of N,N-dimethylformamide and place them in a container. Stir evenly and place them at 2°C. Slowly add 10 parts of 2-chloromethylbenzimidazole into the container, then heat it to 45°C and keep it warm for 10 hours. Place the mixture in the container in a dialysis bag with a molecular weight cutoff of 1200Da and dialyze it with deionized water for 40 hours. Then freeze-dry it to obtain an antiseptic functionalized alcohol ether.

[0073] S2: Dynamic hydrophobic migration microsphere filler

[0074] S2.1: Place 20 parts of N-vinyl pyrrolidone and 6 parts of itaconic acid in a container, add 0.5 wt% of AIBN initiator, and react at 65°C for 2 hours to obtain a carboxyl-functionalized copolymer. Mix the carboxyl-functionalized copolymer with 3 parts of octadecylamine, add the mixture to 40 parts of N,N-dimethylformamide, and incubate at 130°C for 4 hours to obtain a migration promoter.

[0075] S2.2: Melt-mix 25 parts of cardanol glycidyl ether and 10 parts of liquid paraffin at 85°C, add 4 parts of a migration accelerator, stir until uniform, then add 5 parts of 50 nm nano-cerium oxide and 5 wt% of Tween-80, and shear the mixture at 2000 rpm for 10 minutes to obtain a uniform emulsion.

[0076] S2.3: Add the uniform emulsion to 100 parts of 2% sodium alginate solution, ultrasonically stir at a frequency of 35 kHz for 20 minutes, then add 60 parts of 5% CaCl2 solution, stir at a speed of 400 rpm for 35 minutes, let it stand for 15 minutes, add 50 parts of perfluorooctyltriethoxysilane / acetone solution and stir evenly, wherein the mass fraction of perfluorooctyltriethoxysilane is 16%, continue to stand for 30 minutes, and finally centrifuge at a speed of 8000 rpm for 20 minutes, discard the upper layer of liquid and retain the lower layer of microcapsules, and place the microcapsules in an environment of minus 35°C for freeze-drying for 8 hours to obtain dynamic hydrophobic migration microsphere fillers.

[0077] S3: Hydrophilic modification of isocyanate and blending of prepolymers

[0078] S3.1: Add 5 wt% activated molecular sieves to toluene diisocyanate, stir well, and soak for 8 days. Store in a sealed container to obtain anhydrous toluene diisocyanate. Dry 3-cyclohexylaminopropanesulfonic acid in a vacuum oven to constant weight, cool to room temperature, and store in a dry environment to obtain anhydrous 3-cyclohexylaminopropanesulfonic acid.

[0079] S3.2: 10 parts of anhydrous toluene diisocyanate and 4 parts of butyl acetate were mixed and added to a container equipped with a stirrer, a condenser, and a thermometer. The mixture was heated to 85°C under a nitrogen atmosphere. 0.8 parts of anhydrous 3-cyclohexylaminopropanesulfonic acid and 0.8 parts of dimethylcyclohexylamine were then added. The mixture was kept at reflux for 8 hours and cooled to obtain a hydrophilic TDI curing agent.

[0080] S3.3: Place the anti-corrosion functionalized alcohol ether in a container equipped with a stirrer, condenser, and thermometer, and heat to 85°C in a nitrogen atmosphere. Then, add toluene diisocyanate at an NCO-OH ratio of 1:0.85. Keep the mixture warm for 4 hours. When the temperature drops to 40°C, add 25 wt% acetone, and cool naturally to room temperature to obtain a prepolymer dispersion.

[0081] S3.4: Place the prepolymer dispersion in a dry container, add 4 wt% of dynamic hydrophobic migration microsphere filler and 3 wt% of dodecyl alcohol ester, and then add hydrophilic TDI curing agent according to the NCO-OH ratio of 1:0.9 based on the OH content in the prepolymer dispersion. After stirring evenly, filter, measure and package to obtain a waterproof and anti-corrosion two-component cyanoacrylate composite coating.

[0082] Comparative Example 1

[0083] A method for preparing a waterproof and anti-corrosion two-component cyanide coagulant composite coating is different from Example 1 in that step S2 is removed from Example 1, and the dynamic hydrophobic migration microsphere filler in step S3.4 is replaced with talcum powder of equal mass. The remaining steps are the same as in Example 1 to prepare a waterproof and anti-corrosion two-component cyanide coagulant composite coating, which is recorded as Comparative Example 1.

[0084] Comparative Example 2

[0085] A method for preparing a waterproof and anti-corrosion two-component cyanide coagulant composite coating is different from Example 1 in that Example 2 removes step S1 and replaces the anti-corrosion functionalized alcohol ether in step S3.3 with an equal mass of polyoxyethylene alcohol. The remaining steps are the same as Example 1 to obtain a waterproof and anti-corrosion two-component cyanide coagulant composite coating, which is recorded as Example 2.

[0086] Comparative Example 3

[0087] A method for preparing a waterproof and anti-corrosion two-component cyanide coagulant composite coating is disclosed. The method differs from Example 1 in that, in Comparative Example 3, the hydrophilic TDI curing agent in step S3.4 is replaced with an equal mass of Bayhydur 3100 water-based isocyanate curing agent. The remaining steps are the same as in Example 1 to obtain a waterproof and anti-corrosion two-component cyanide coagulant composite coating, which is recorded as Comparative Example 3.

[0088] Examples 1-3 and comparative examples 1-3 were evenly sprayed onto a polytetrafluoroethylene plate with a thickness of 1 mm. After drying at room temperature for 3 days, they were placed in a drying oven at a constant temperature of 45°C and dried to constant weight. The film samples were then cut into dumbbell-shaped strips of the same size on a sheet punching machine.

[0089] Mechanical properties test: Three samples of the films of Examples 1-3, Comparative Example 1, and Comparative Example 3 were taken and the tensile strength and elongation at break were measured on a microcomputer-controlled electronic universal testing machine at a tensile speed of 200 mm / min. The test results were averaged.

[0090] Bond strength: Refer to GB / T19250-2013 "Polyurethane Waterproof Coating" to test the bond strength of the film sample. Take three samples for testing and take the average value of the test results;

[0091] Water resistance test: Water absorption of the outer layer of the film: Take the film samples of Examples 1-3, Comparative Example 1 and Comparative Example 3, take six samples each, and bond the inner layers of two of the same film samples. Weigh the bonded film and record the mass as m1. Soak it in distilled water for 48 hours, take it out, dry the surface moisture with absorbent paper, and then weigh the film mass and record it as m2 to calculate the water absorption rate. 外= (m2-m1) / m1×100%, the calculated result is the average value; water absorption of the inner layer of the film: take six film samples of Examples 1-3, Comparative Example 1 and Comparative Example 3, and bond the outer layers of two of the same film sample. Weigh the bonded film and record the mass as m3. Soak it in distilled water for 48 hours, take it out, dry the surface moisture with absorbent paper, and then weigh the film mass and record it as m4 to calculate the water absorption rate 内 = (m4-m3) / m3×100%, the calculated result is the average value. The greater the water absorption rate, the worse the water resistance;

[0092] The above data were recorded and tabulated, and the results are shown in Table 1.

[0093] Table 1: Performance of waterproof and anti-corrosion two-component cyanocondensate composite coating after film formation

[0094]

[0095] It can be seen from Table 1 that the tensile strength and elongation at break of Examples 1-3 are higher than those of Comparative Example 1 and Comparative Example 3, while the water absorption is lower than that of Comparative Example 1 and Comparative Example 3. This proves that the dynamic hydrophobic migration microsphere filler can give the coating better mechanical properties, adhesion and waterproof properties after film formation. At the same time, it can be proved that the prepared hydrophilic TDI curing agent can better improve the crosslinking density and tensile strength of the film layer. The water absorption in Table 1 shows that the tensile strength and elongation at break of Examples 1-3 are higher than those of Comparative Example 1 and Comparative Example 3. 外 and water absorption 内 It can be seen from the data that the water resistance of the outer surface of the film samples prepared in Examples 1-3 and Comparative Example 3 is higher than that of the inner surface. The reason is that the hydrophobic components in the dynamic hydrophobic migration microsphere filler migrate to the outer surface, resulting in a decrease in the hydrophobic performance of the inner surface, but at the same time improving the mechanical properties and adhesion of the film. The difference between the inner and outer surfaces of the film sample prepared in Comparative Example 1 is not much because the talc powder is evenly dispersed inside the film layer, but this will affect the mechanical properties and adhesion of the film layer.

[0096] Experiment 2: Corrosion resistance test: Examples 1-3 and Comparative Example 2 were evenly sprayed on a stainless steel substrate with a thickness of 100 μm. After drying at room temperature for 3 days, they were placed in a drying oven at a constant temperature of 45°C and dried to constant weight. Three portions of each were taken for neutral salt spray resistance test in accordance with GB / T10125-2021 "Artificial Atmosphere Corrosion Test Salt Spray Test". The number of days for rust to occur was recorded. The observation results are shown in Table 2.

[0097] Table 2: Observation results of corrosion treatment

[0098]

[0099] It can be seen from the data of Examples 1-3 and Comparative Example 2 in Table 2 that the polyurethane prepolymer prepared by the stepwise addition polymerization reaction of the anti-corrosion functionalized alcohol ether and toluene diisocyanate can provide excellent anti-corrosion performance after film formation.

[0100] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A method for preparing a waterproof and anti-corrosion two-component cyanocondensation composite coating, characterized in that: The following steps are involved: S1: Preparation of anti-corrosion functionalized alcohol ethers Pentaerythritol, cholesteryl chloride and pyridine are mixed and reacted at high temperature, and after impurity removal and dehydration, a single-arm substituted pentaerythritol ether is obtained, which is then reacted with triphenyl thiophosphate, anhydrous potassium carbonate and potassium iodide at high temperature, and a modified substituted alcohol ether is obtained after extraction, which is then modified with 2-chloromethylbenzimidazole to obtain an anti-corrosion functionalized alcohol ether. S2: Dynamic hydrophobic migration microsphere filler A carboxyl-functionalized copolymer is obtained by mixing N-vinyl pyrrolidone and itaconic acid, which is then mixed with octadecylamine to obtain a migration promoter. Cardanol glycidyl ether and liquid paraffin are co-melted, and the migration promoter and nano-cerium oxide are added. After high-speed shearing, the mixture is encapsulated with sodium alginate and CaCl2 to obtain a dynamic hydrophobic migration microsphere filler. S3: Hydrophilic modification of isocyanate and blending of prepolymers Toluene diisocyanate and 3-cyclohexylaminopropanesulfonic acid are dehydrated and heated to perform a condensation reflux reaction to obtain a hydrophilic TDI curing agent. The anti-corrosion functionalized alcohol ether and toluene diisocyanate are then co-heated for prepolymerization to obtain a prepolymer dispersion. Dynamic hydrophobic migration microsphere filler, film-forming agent dodecyl alcohol ester and hydrophilic TDI curing agent are then added and mixed. The mixture is filtered and packaged to obtain a waterproof and anti-corrosion two-component cyanocondensate composite coating.

2. The method for preparing a waterproof and anti-corrosion two-component cyanide coagulant composite coating according to claim 1, characterized in that: Step S1: Preparation of anti-corrosion functionalized alcohol ether, comprising the following steps: S1.1: Pentaerythritol and cholesteryl chloride are placed in an autoclave at a molar ratio of 1:(1-1.5), 30-35 parts of pyridine are added, and nitrogen is introduced. The air in the autoclave is displaced, and the temperature is raised to 40-45°C. The reaction is stirred at 450-500 rpm for 10-12 hours, and the pyridine is recovered by vacuum distillation to obtain a reaction product. The reactant is extracted 3-4 times with saturated NaHCO3-ethyl acetate solution to obtain an organic phase. Anhydrous MgSO4 is added, stirred for 1-1.5 hours, and then filtered to obtain a single-arm substituted pentaerythritol ether. S1.2: Under nitrogen, place 18-20 parts of triphenyl thiophosphate, 6-8 parts of anhydrous potassium carbonate, and 0.3-0.4 parts of potassium iodide in a container, add 160-200 parts of anhydrous acetonitrile, activate at 50-55°C for 25-30 minutes, then slowly add 80-100 parts of a single-arm substituted pentaerythritol ether, raise the temperature to 60-65°C, and keep the temperature for 10-12 hours. After filtering to remove salt, perform supercritical CO2 extraction to obtain a modified substituted alcohol ether. S1.3: Take 10-12 parts of modified substituted alcohol ether and 15-20 parts of N,N-dimethylformamide and place them in a container. After stirring evenly, place it in an environment of 0-2°C. Slowly add 10-12 parts of 2-chloromethylbenzimidazole into the container, then heat it to 40-45°C and keep it warm for 8-10 hours. Place the mixture in the container in a dialysis bag and dialyze it with deionized water for 30-40 hours. Then, freeze-dry it to obtain an antiseptic functionalized alcohol ether.

3. The method for preparing a waterproof and anti-corrosion two-component cyanide coagulant composite coating according to claim 2, characterized in that: Step S2: dynamic hydrophobic migration microsphere filler, comprising the following steps: S2.1: Place 20-25 parts of N-vinyl pyrrolidone and 6-8 parts of itaconic acid in a container, add 0.5-0.6 wt% of AIBN initiator, and react at 60-65°C for 1.5-2 hours to obtain a carboxyl-functionalized copolymer. Mix the carboxyl-functionalized copolymer with 3-5 parts of octadecylamine, add the mixture to 40-45 parts of N,N-dimethylformamide, and incubate at 120-130°C for 3.5-4 hours to obtain a migration promoter. S2.2: Melt-mix 25-30 parts of cardanol glycidyl ether and 10-15 parts of liquid paraffin at 80-85°C, add 4-6 parts of a migration accelerator, stir evenly, then add 5-8 parts of nano-cerium oxide and 4-5 wt% of Tween-80, and shear the mixture at 2000-2500 rpm for 8-10 minutes to obtain a uniform emulsion; S2.3: Add the uniform emulsion to 100-120 parts of a 1-2% sodium alginate solution, ultrasonically stir at a frequency of 30-35 kHz for 15-20 minutes, then add 60-80 parts of a 3-5% CaCl2 solution, stir at a speed of 300-400 rpm for 30-35 minutes, let it stand for 10-15 minutes, then add 50-60 parts of perfluorooctyltriethoxysilane / acetone solution and stir evenly, wherein the mass fraction of perfluorooctyltriethoxysilane is 14-16%, continue to stand for 25-30 minutes, and finally centrifuge at a speed of 6000-8000 rpm for 18-20 minutes, discard the upper layer of liquid and retain the lower layer of microcapsules, and place the microcapsules in an environment of -40°C to -35°C for freeze-drying for 6-8 hours to obtain dynamic hydrophobic migration microsphere fillers.

4. The method for preparing a waterproof and anti-corrosion two-component cyanide coagulant composite coating according to claim 3, characterized in that: Step S3: hydrophilic modification of isocyanate and blending of prepolymer, comprising the following steps: S3.1: Add 5-6 wt% activated molecular sieves to toluene diisocyanate, stir well, and soak for 7-8 days. Store in a sealed container to obtain anhydrous toluene diisocyanate. Dry 3-cyclohexylaminopropanesulfonic acid in a vacuum oven to constant weight, cool to room temperature, and store in a dry environment to obtain anhydrous 3-cyclohexylaminopropanesulfonic acid. S3.2: Mix 10-15 parts of anhydrous toluene diisocyanate and 4-5 parts of butyl acetate in a container equipped with a stirrer, a condenser, and a thermometer. Heat to 80-85°C under a nitrogen atmosphere. Then add 0.8-1 part of anhydrous 3-cyclohexylaminopropanesulfonic acid and 0.8-1 part of dimethylcyclohexylamine. Keep the mixture under reflux for 8-10 hours. Cool the mixture to obtain a hydrophilic TDI curing agent. S3.3: Place the anti-corrosion functionalized alcohol ether in a container equipped with a stirrer, condenser, and thermometer, and heat to 80-85°C in a nitrogen atmosphere. Then, add toluene diisocyanate at an NCO-OH ratio of 1:(0.85-0.9). Keep the mixture warm for 3-4 hours. When the temperature drops to 35-40°C, add 25-30 wt% acetone, and cool naturally to room temperature to obtain a prepolymer dispersion. S3.4: Place the prepolymer dispersion in a dry container, add 4-6wt% of dynamic hydrophobic migration microsphere filler and 3-5wt% of film-forming agent, and then add hydrophilic TDI curing agent according to the OH content in the prepolymer dispersion and the NCO-OH ratio of 1: (0.9-0.92). After stirring evenly, filter, measure and package to obtain a waterproof and anti-corrosion two-component cyanoacrylate composite coating.

5. The method for preparing a waterproof and anti-corrosion two-component cyanide coagulant composite coating according to claim 2, characterized in that: The volume ratio of the saturated NaHCO 3 solution to ethyl acetate in the saturated NaHCO 3 -ethyl acetate solution in step S1.1 is 1:(2.5-3).

6. The method for preparing a waterproof and anti-corrosion two-component cyanide coagulant composite coating according to claim 2, characterized in that: The molecular weight cut-off of the dialysis bag in step S1.3 is 1000-1200 Da.

7. The method for preparing a waterproof and anti-corrosion two-component cyanide coagulant composite coating according to claim 3, characterized in that: The particle size of nano-cerium oxide in step S2.2 is 30-50 nm.

8. A waterproof and anti-corrosion two-component cyanocondensation composite coating, characterized in that: The waterproof and anti-corrosion two-component cyanide coagulant composite coating is prepared by the preparation method of any one of claims 1 to 7.

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