Heavy-duty strong acid and alkali resistant modified nano environmental protection coating and preparation method thereof

Abstract

This invention discloses a heavy-duty anti-corrosion and strong acid / alkali resistant modified nano-environmentally friendly coating and its preparation method. Through emulsification technology, utilizing the emulsifier fatty alcohol polyoxyethylene ether and shear force, a poorly water-soluble film-forming base material, modified filler, and functional additives are stably dispersed in water in the form of tiny particles, thus obtaining a heavy-duty anti-corrosion and strong acid / alkali resistant modified nano-environmentally friendly coating. The main chain of the film-forming base material is Si-O-Si bonded, with high bond energy, good thermal stability, and low surface energy. During the coating curing process, the siloxane segments on the film-forming base material molecular chain and the hydrophobically modified functional additives spontaneously migrate to the interface between the coating and air, forming a molecularly smooth superhydrophobic layer on the surface, effectively blocking the penetration of water molecules and corrosive ions, thus endowing the coating with excellent corrosion resistance. The platy basalt flakes can be arranged in parallel and interlaced within the coating to form a "maze effect," improving the coating's shielding and anti-corrosion properties.

Description

Technical Field

[0001] This invention relates to the field of coating preparation technology, specifically to a heavy-duty anti-corrosion and strong acid and alkali resistant modified nano-environmentally friendly coating and its preparation method. Background Technology

[0002] Heavy-duty anti-corrosion and acid / alkali resistant modified nano-environmentally friendly coatings are mainly used in harsh industrial environments such as petrochemicals, marine engineering, power equipment, metallurgy, and environmental protection facilities for long-term protection of metal and concrete substrates. In these conditions, the substrates are exposed to high concentrations of acids, strong alkaline media, and corrosive salt spray for extended periods, placing extremely high demands on the chemical stability and physical barrier performance of the coating. Existing traditional coatings have significant drawbacks in practical applications: in terms of corrosion resistance, the coating is prone to forming micropores due to media penetration, leading to pitting and under-film corrosion, resulting in a protection life far below design expectations; in terms of strong alkali resistance, conventional resin systems are prone to saponification degradation in high-temperature, high-concentration alkaline environments, causing the coating to lose gloss, chalk, or even peel off completely, losing its shielding ability. Furthermore, some traditional products require the use of highly volatile organic solvents to achieve heavy-duty anti-corrosion effects, resulting in poor environmental performance and difficulty in simultaneously meeting the dispersion stability and dense film formation requirements of nano-modification. Summary of the Invention

[0003] The purpose of this invention is to provide a heavy-duty anti-corrosion and strong acid and alkali resistant modified nano-environmentally friendly coating to solve the defects of traditional coatings in terms of corrosion resistance and strong acid and alkali resistance.

[0004] The objective of this invention can be achieved through the following technical solutions:

[0005] A method for preparing a heavy-duty anti-corrosion and strong acid and alkali resistant modified nano-environmentally friendly coating specifically includes the following steps:

[0006] The film-forming base material, modified filler, functional additives, and propylene glycol methyl ether are mixed evenly. Under the conditions of 1000-2000 r / min and 40-50℃, fatty alcohol polyoxyethylene ether is added and stirred evenly for 30-50 min. Then, deionized water is added and stirred for 20-40 min. Under the conditions of 200-400 r / min, 20-25℃, and in the dark, initiator 2959 and triallyl isocyanurate are added and stirred for 15-30 min to obtain a heavy-duty anti-corrosion and strong acid and alkali resistant modified nano-environmentally friendly coating.

[0007] Furthermore, the weight ratio of the film-forming base material, modified filler, functional additive, propylene glycol methyl ether, fatty alcohol polyoxyethylene ether, initiator 2959, triallyl isocyanurate and deionized water in the step is 50-60:6-8:6-8:2-4:2-3:0.3-0.5:3-5:60-80.

[0008] Furthermore, the film-forming base material is prepared by the following steps:

[0009] Step A1: Mix 2,4,6,8-tetramethylcyclotetrasiloxane, hexamethyldisiloxane and toluene evenly, stir at 180-200 r / min and 20-25℃, add potassium hydroxide and deionized water, and hydrolyze for 4-6 h. Then, react at 120-140℃ under nitrogen gas for 6-8 h to obtain pretreated polysiloxane.

[0010] Step A2: Mix the pretreated polysiloxane, tetrahydrofuran, ethynylcyclohexanol and allyl alcohol evenly. Stir and add a solution of isopropanol in chloroplatinic acid at a speed of 150-160 r / min, a temperature of 70-100℃ and a pH of 7, and react for 2-4 hours to obtain the modified siloxane. Mix the modified siloxane and tetrahydrofuran evenly. Stir and add dibutyltin dilaurate, triethylamine and methylvinyl dichlorosilane at a speed of 200-300 r / min and a temperature of 50-60℃, and react for 2-3 hours to obtain the film-forming base material.

[0011] Furthermore, the ratio of 2,4,6,8-tetramethylcyclotetrasiloxane, hexamethyldisiloxane, toluene, potassium hydroxide, and deionized water in step A1 is 0.2 mol: 0.2 g: 54 g: 1.2 g: 0.8 mol.

[0012] Furthermore, in step A2, the molar ratio of the silane-hydrogen bonds on the pretreated polysiloxane to the carbon-carbon double bonds on the allyl alcohol is 1:1.1, the amount of ethynylcyclohexanol used is 0.5-1% of the mass of allyl alcohol, the amount of isopropanol solution of chloroplatinic acid used is 0.1-0.5% of the mass of polysiloxane, the mass ratio of chloroplatinic acid to isopropanol is 0.01:9, and the ratio of the amount of modified siloxane, tetrahydrofuran, dibutyltin dilaurate, triethylamine, and methylvinyldichlorosilane used is 1mol:20mL:0.2g:15mL:2.2mol.

[0013] Furthermore, the functional additive is prepared by the following steps:

[0014] Ethanol and deionized water are mixed evenly, and under conditions of 160-200 r / min, 60-70℃, and pH 6-7, tetraethyl orthosilicate and vinyltriethoxysilane are added while stirring. The mixture is reacted for 8-10 h to obtain a pretreatment aid. The pretreatment aid is dispersed in tetrahydrofuran, and under conditions of 200-300 r / min, 60-70℃, hexadecyltrimethoxysilane is added while stirring. The mixture is reacted for 10-12 h to obtain a functional aid.

[0015] Furthermore, the ratio of ethanol, deionized water, tetraethyl orthosilicate, and vinyltriethoxysilane used in the step is 25g:10g:0.2mol:0.05mol, and the amount of hexadecyltrimethoxysilane used is 1-3% of the mass of the pretreatment aid.

[0016] Furthermore, the modified filler is prepared by the following steps:

[0017] Step B1: Place basalt flakes in a sodium hydroxide solution and react for 1-2 hours at a rotation speed of 120-150 r / min and a temperature of 90-100℃ to obtain pretreated basalt flakes. Mix zirconium nitrate and deionized water evenly and stir and add the pretreated basalt flakes at a rotation speed of 160-200 r / min, a temperature of 20-30℃ and a pH of 11-12. After reacting for 2-4 hours, heat treat at a temperature of 680-700℃ for 4-5 hours to obtain modified basalt flakes.

[0018] Step B2: Stearic acid and ethanol are mixed evenly and stirred for 20-30 minutes at a speed of 200-300 r / min and a temperature of 60-70℃. The pH is adjusted to 7.5-8, and modified basalt flakes are added while stirring at a speed of 160-180 r / min and a temperature of 70-80℃. The reaction is carried out for 2-3 hours to obtain the pretreated filler. The pretreated filler is dispersed in an ethanol solution of ferric chloride and ultrasonically treated for 10-20 minutes at a frequency of 30-40 kHz to obtain the pretreated filler.

[0019] Step B3: Place the pretreated filler in an ethanol solution of pyrrole and stir for 30-50 minutes at a speed of 130-150 r / min and a temperature of 0-5℃. Add sulfosalicylic acid, sodium anthraquinone sulfonate and deionized water, and sonicate for 5-10 minutes at a frequency of 30-40 kHz. Then, raise the temperature to 20-35℃, stir and add ammonium persulfate, and react for 8-10 hours to obtain the modified filler.

[0020] Furthermore, in step B1, the ratio of basalt flakes to sodium hydroxide solution is 3g:100mL, the molar concentration of sodium hydroxide solution is 4mol / L, and the ratio of zirconium nitrate, deionized water, and pretreated basalt flakes is 1.49g:1500mL:0.6g.

[0021] Furthermore, in step B2, the ratio of stearic acid, ethanol, and modified basalt flakes is 1g:200mL:3g, and the ratio of pretreatment filler to ferric chloride ethanol solution is 1g:10mL. The ferric chloride ethanol solution is prepared by dissolving 0.1mol of ferric chloride in 1L of ethanol.

[0022] Furthermore, in step B3, the ratio of the pretreatment packing material, pyrrole ethanol solution, sulfosalicylic acid, sodium anthraquinone sulfonate, deionized water, and ammonium persulfate is 1g:10mL:0.5mmol:1mmol:100mL:2.5mmol. The pyrrole ethanol solution is prepared by dissolving 0.5mol of pyrrole in 1L of ethanol.

[0023] The beneficial effects of this invention are as follows: By using emulsification technology, and utilizing the emulsifier fatty alcohol polyoxyethylene ether and shear force, the poorly water-soluble film-forming base material, modified filler, and functional additives are stably dispersed in water in the form of tiny particles, thus producing a heavy-duty anti-corrosion and strong acid and alkali resistant modified nano-environmentally friendly coating. In the subsequent coating process, heat treatment is first used to promote the evaporation of the solvent water, followed by ultraviolet irradiation treatment to promote the polymerization of the film-forming base material, functional additives, and triallyl isocyanurate, which then crosslinks and cures to form a three-dimensional crosslinked network structure coating.

[0024] Film-forming base material: Potassium hydroxide, acting as an alkaline catalyst, attracts hydroxide ions that attack the Si-O bonds on 2,4,6,8-tetramethylcyclotetrasiloxane, opening the ring and forming a linear oligomer with terminal active centers. This oligomer then attacks other 2,4,6,8-tetramethylcyclotetrasiloxane monomers, promoting chain growth. Hexamethyldisiloxane acts as a capping agent, terminating the polymer chain growth process to obtain pretreated polysiloxane. The active silane-hydrogen bonds on the pretreated polysiloxane react with the carbon-carbon double bonds on allyl alcohol under platinum catalysis to obtain modified siloxane. The hydroxyl groups on the modified siloxane react with the silicon-chlorine bonds on methylvinyldichlorosilane to form Si-O-Si chemical bonds, thus obtaining the film-forming base material.

[0025] Functional additives: Under weakly acidic conditions, the ethoxy groups in tetraethyl orthosilicate and vinyltriethoxysilane undergo hydrolysis to generate silanol groups, which then undergo a condensation reaction to obtain a pretreatment additive; hexadecyltrimethoxysilane undergoes hydrolysis to generate silanol groups, which then undergo dehydration condensation with the silanol groups on the surface of the pretreatment additive to form stable Si-O-Si chemical bonds, thus obtaining a functional additive.

[0026] Modified filler: Basalt flakes are pretreated by alkaline etching. Zirconium nitrate undergoes vigorous hydrolysis in water, resulting in an acidic solution. The pH is adjusted by adding alkali, promoting the hydrolysis reaction to the right. The hydrated zirconium oxide or zirconium hydroxide precipitate generated by the hydrolysis reaction is chemically bonded and adsorbed onto the surface of the pretreated basalt flakes. Then, through high-temperature heat treatment, a crystal transformation occurs, forming zirconium oxide-coated basalt flakes, thus obtaining modified basalt flakes. Under weakly alkaline conditions, stearic acid undergoes a neutralization reaction, converting into stearate ions containing lone pairs of electrons. These ions then react with the hydroxyl groups on the zirconium oxide surface of the modified basalt flakes in a Lewis acid-base reaction, introducing long-chain alkyl groups to obtain the pretreated filler. Ethanol is used as a co-solvent to reduce the solid-liquid interfacial tension, allowing the Fe-containing... 3＋ The solution can effectively contact the hydrophobic surface to achieve Fe 3＋ Pre-loaded onto the packing surface, pre-treated packing is obtained. Fe 3＋ As a Lewis acid, it has an anchoring effect and can form coordination bonds with the nitrogen atoms of pyrrole. Then, through chemical oxidative polymerization, the pyrrole monomer is deposited in situ onto the surface of the pretreated filler. At the same time, two organic acids are used as dopants to prepare modified fillers.

[0027] The main chain of the film-forming matrix consists of Si-O-Si bonds, which have high bond energy, good thermal stability, and low surface energy. During the coating curing process, the siloxane segments and hydrophobically modified functional additives on the molecular chain of the film-forming matrix spontaneously migrate to the interface between the coating and the air, forming a molecularly smooth superhydrophobic layer on the surface. This effectively blocks the penetration of water molecules and corrosive ions, giving the coating excellent corrosion resistance. The cross-linking of the film-forming matrix, functional additives, and triallyl isocyanurate forms a dense three-dimensional network structure, improving the density of the coating and extending the path of corrosive media (including strong acids and alkalis) from the coating to the metal substrate, thus significantly improving its resistance to corrosion ions in solution and its resistance to strong acids and alkalis. After coating basalt flakes with zirconium oxide and then hydrophobically modifying them, acid-doped polypyrrole polymers are deposited on their surface using chemical oxidation polymerization to obtain modified fillers. The flaky basalt flakes can be arranged in parallel and interlaced in the coating to form a "maze effect," improving the coating's shielding and corrosion resistance. A zirconium oxide coating was prepared on the surface using a precipitation-calcination method, forming a core-shell structure. Zirconia exhibits extremely high chemical inertness to strong acids and alkalis, and the synergistic effect of these properties enhances the coating's resistance to strong acids and alkalis. Hydrophobic modification with stearic acid prevents corrosive media from spreading on the filler surface, reducing their driving force for penetration into the coating. The conductive polymer polypyrrole, through electrochemical reaction, passivates the exposed metal substrate, preventing further dissolution and thus improving the coating's corrosion resistance and resistance to strong acids and alkalis. Detailed Implementation

[0028] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Example 1: A method for preparing a heavy-duty anti-corrosion and strong acid and alkali resistant modified nano-environmentally friendly coating, specifically including the following steps:

[0030] The film-forming base material, modified filler, functional additives and propylene glycol methyl ether were mixed evenly. Fatty alcohol polyoxyethylene ether was added under the conditions of 1000 r / min and 40℃. After stirring evenly for 30 min, deionized water was added and stirred for 20 min. Under the conditions of 200 r / min, 20℃ and light protection, initiator 2959 and triallyl isocyanurate were added and stirred for 15 min to obtain a heavy-duty anti-corrosion and strong acid and alkali resistant modified nano-environmentally friendly coating.

[0031] The weight ratio of the film-forming base material, modified filler, functional additive, propylene glycol methyl ether, fatty alcohol polyoxyethylene ether, initiator 2959, triallyl isocyanurate and deionized water mentioned in the steps is 50:6:6:2:2:0.3:3:60.

[0032] The film-forming base material is prepared by the following steps:

[0033] Step A1: Mix 2,4,6,8-tetramethylcyclotetrasiloxane, hexamethyldisiloxane and toluene evenly, stir at 180 r / min and 20°C, add potassium hydroxide and deionized water, and hydrolyze for 4 h. Then, react at 120°C and under nitrogen gas for 6 h to obtain pretreated polysiloxane.

[0034] Step A2: Mix the pretreated polysiloxane, tetrahydrofuran, ethynylcyclohexanol and allyl alcohol evenly. Stir and add a solution of isopropanol in chloroplatinic acid at a speed of 150 r / min, a temperature of 70 ℃ and a pH of 7, and react for 2 h to obtain the modified siloxane. Mix the modified siloxane and tetrahydrofuran evenly. Stir and add dibutyltin dilaurate, triethylamine and methylvinyl dichlorosilane at a speed of 200 r / min and a temperature of 50 ℃, and react for 2 h to obtain the film-forming base material.

[0035] The ratio of 2,4,6,8-tetramethylcyclotetrasiloxane, hexamethyldisiloxane, toluene, potassium hydroxide, and deionized water in step A1 is 0.2 mol: 0.2 g: 54 g: 1.2 g: 0.8 mol, and the ratio of 2,4,6,8-tetramethylcyclotetrasiloxane is 1 mmol.

[0036] In step A2, the molar ratio of the silane-hydrogen bonds on the pretreated polysiloxane to the carbon-carbon double bonds on the allyl alcohol is 1:1.1. The amount of ethynylcyclohexanol used is 0.5% of the mass of allyl alcohol. The amount of the isopropanol solution of chloroplatinic acid used is 0.1% of the mass of polysiloxane. The mass ratio of chloroplatinic acid to isopropanol is 0.01:9. The ratio of the amount of modified siloxane, tetrahydrofuran, dibutyltin dilaurate, triethylamine, and methylvinyldichlorosilane used is 1 mol: 20 mL: 0.2 g: 15 mL: 2.2 mol.

[0037] The functional additive is prepared by the following steps:

[0038] Ethanol and deionized water were mixed evenly, and then stirred and added with tetraethyl orthosilicate and vinyltriethoxysilane at a speed of 160 r / min, a temperature of 60 °C, and a pH of 6. The mixture was reacted for 8 h to obtain a pretreatment aid. The pretreatment aid was dispersed in tetrahydrofuran, and then stirred and added with hexadecyltrimethoxysilane at a speed of 200 r / min and a temperature of 60 °C. The mixture was reacted for 10 h to obtain a functional aid.

[0039] The ratio of ethanol, deionized water, tetraethyl orthosilicate and vinyltriethoxysilane used in the step is 25g:10g:0.2mol:0.05mol, and the amount of hexadecyltrimethoxysilane used is 1% of the mass of the pretreatment aid.

[0040] The modified filler is prepared by the following steps:

[0041] Step B1: Basalt flakes were placed in a sodium hydroxide solution and reacted for 1 hour at a speed of 120 r / min and a temperature of 90 °C to obtain pretreated basalt flakes. Zirconium nitrate and deionized water were mixed evenly and stirred and added to the pretreated basalt flakes at a speed of 160 r / min, a temperature of 20 °C and a pH of 11. After reacting for 2 hours, the mixture was heated at a temperature of 680 °C for 4 hours to obtain modified basalt flakes.

[0042] Step B2: Stearic acid and ethanol are mixed evenly and stirred for 20 minutes at 200 r / min and 60℃. The pH is adjusted to 7.5, and modified basalt flakes are added while stirring at 160 r / min and 70℃. The reaction is carried out for 2 hours to obtain the pretreated filler. The pretreated filler is dispersed in an ethanol solution of ferric chloride and ultrasonically treated for 10 minutes at a frequency of 30 kHz to obtain the pretreated filler.

[0043] Step B3: Place the pretreated filler in an ethanol solution of pyrrole and stir for 30 min at a speed of 130 r / min and a temperature of 0℃. Add sulfosalicylic acid, sodium anthraquinone sulfonate and deionized water. After ultrasonic treatment for 5 min at a frequency of 30 kHz, raise the temperature to 20℃, stir and add ammonium persulfate, and react for 8 h to obtain the modified filler.

[0044] The ratio of basalt flakes to sodium hydroxide solution in step B1 is 3g:100mL, the molar concentration of sodium hydroxide solution is 4mol / L, and the ratio of zirconium nitrate, deionized water and pretreated basalt flakes is 1.49g:1500mL:0.6g.

[0045] The ratio of stearic acid, ethanol and modified basalt flakes in step B2 is 1g:200mL:3g, and the ratio of pretreatment filler and ferric chloride ethanol solution is 1g:10mL. The ferric chloride ethanol solution is prepared by dissolving 0.1mol of ferric chloride in 1L of ethanol.

[0046] The ratio of the pretreatment packing material, pyrrole ethanol solution, sulfosalicylic acid, sodium anthraquinone sulfonate, deionized water and ammonium persulfate in step B3 is 1g:10mL:0.5mmol:1mmol:100mL:2.5mmol. The volume of the pyrrole ethanol solution is 1mL, which is prepared by dissolving 0.5mol of pyrrole in 1L of ethanol.

[0047] Example 2: A method for preparing a heavy-duty anti-corrosion and strong acid and alkali resistant modified nano-environmentally friendly coating, specifically including the following steps:

[0048] The film-forming base material, modified filler, functional additives and propylene glycol methyl ether were mixed evenly. Fatty alcohol polyoxyethylene ether was added at a speed of 1500 r / min and a temperature of 45℃. After stirring evenly for 40 min, deionized water was added and stirred for 30 min. Initiator 2959 and triallyl isocyanurate were added at a speed of 300 r / min, a temperature of 20℃ and in the dark. After stirring for 20 min, a heavy-duty anti-corrosion and strong acid and alkali resistant modified nano-environmentally friendly coating was obtained.

[0049] The weight ratio of the film-forming base material, modified filler, functional additive, propylene glycol methyl ether, fatty alcohol polyoxyethylene ether, initiator 2959, triallyl isocyanurate and deionized water mentioned in the steps is 55:7:7:2:2:0.3:3:60.

[0050] The film-forming base material is prepared by the following steps:

[0051] Step A1: Mix 2,4,6,8-tetramethylcyclotetrasiloxane, hexamethyldisiloxane and toluene evenly, stir at 190 r / min and 22°C, add potassium hydroxide and deionized water, and hydrolyze for 5 h. Then, react at 130°C and under nitrogen gas for 7 h to obtain pretreated polysiloxane.

[0052] Step A2: Mix the pretreated polysiloxane, tetrahydrofuran, ethynylcyclohexanol and allyl alcohol evenly. Stir and add a solution of isopropanol in chloroplatinic acid at a speed of 155 r / min, a temperature of 80℃ and a pH of 7, and react for 3 h to obtain the modified siloxane. Mix the modified siloxane and tetrahydrofuran evenly. Stir and add dibutyltin dilaurate, triethylamine and methylvinyl dichlorosilane at a speed of 250 r / min and a temperature of 55℃, and react for 2 h to obtain the film-forming base material.

[0053] The ratio of 2,4,6,8-tetramethylcyclotetrasiloxane, hexamethyldisiloxane, toluene, potassium hydroxide, and deionized water in step A1 is 0.2 mol: 0.2 g: 54 g: 1.2 g: 0.8 mol, and the ratio of 2,4,6,8-tetramethylcyclotetrasiloxane is 2 mmol.

[0054] In step A2, the molar ratio of the silane-hydrogen bonds on the pretreated polysiloxane to the carbon-carbon double bonds on the allyl alcohol is 1:1.1. The amount of ethynylcyclohexanol used is 0.5% of the mass of allyl alcohol. The amount of the isopropanol solution of chloroplatinic acid used is 0.1% of the mass of polysiloxane. The mass ratio of chloroplatinic acid to isopropanol is 0.01:9. The ratio of the amount of modified siloxane, tetrahydrofuran, dibutyltin dilaurate, triethylamine, and methylvinyldichlorosilane used is 1 mol: 20 mL: 0.2 g: 15 mL: 2.2 mol.

[0055] The functional additive is prepared by the following steps:

[0056] Ethanol and deionized water were mixed evenly, and then stirred and added with tetraethyl orthosilicate and vinyltriethoxysilane at a speed of 180 r / min, a temperature of 65 °C, and a pH of 6. The mixture was reacted for 9 h to obtain a pretreatment aid. The pretreatment aid was dispersed in tetrahydrofuran, and then stirred and added with hexadecyltrimethoxysilane at a speed of 250 r / min and a temperature of 65 °C. The mixture was reacted for 11 h to obtain a functional aid.

[0057] The ratio of ethanol, deionized water, tetraethyl orthosilicate and vinyltriethoxysilane used in the step is 25g:10g:0.2mol:0.05mol, and the amount of hexadecyltrimethoxysilane used is 2% of the mass of the pretreatment aid.

[0058] The modified filler is prepared by the following steps:

[0059] Step B1: Basalt flakes were placed in a sodium hydroxide solution and reacted for 1 hour at a speed of 130 r / min and a temperature of 95℃ to obtain pretreated basalt flakes. Zirconium nitrate and deionized water were mixed evenly and stirred and added to the pretreated basalt flakes at a speed of 180 r / min, a temperature of 25℃ and a pH of 11. After reacting for 3 hours, the mixture was heated at a temperature of 690℃ for 4 hours to obtain modified basalt flakes.

[0060] Step B2: Stearic acid and ethanol are mixed evenly and stirred for 25 minutes at 250 r / min and 65℃. The pH is adjusted to 7.5, and modified basalt flakes are added while stirring at 170 r / min and 75℃. The reaction is carried out for 2 hours to obtain the pretreated filler. The pretreated filler is dispersed in an ethanol solution of ferric chloride and ultrasonically treated for 15 minutes at a frequency of 35 kHz to obtain the pretreated filler.

[0061] Step B3: Place the pretreated filler in an ethanol solution of pyrrole and stir for 40 min at a speed of 140 r / min and a temperature of 2℃. Add sulfosalicylic acid, sodium anthraquinone sulfonate and deionized water. After ultrasonic treatment for 8 min at a frequency of 35 kHz, raise the temperature to 25℃, stir and add ammonium persulfate, and react for 9 h to obtain the modified filler.

[0062] The ratio of basalt flakes to sodium hydroxide solution in step B1 is 3g:100mL, the molar concentration of sodium hydroxide solution is 4mol / L, and the ratio of zirconium nitrate, deionized water and pretreated basalt flakes is 1.49g:1500mL:0.6g.

[0063] The ratio of stearic acid, ethanol and modified basalt flakes in step B2 is 1g:200mL:3g, and the ratio of pretreatment filler and ferric chloride ethanol solution is 1g:10mL. The ferric chloride ethanol solution is prepared by dissolving 0.1mol of ferric chloride in 1L of ethanol.

[0064] The ratio of the pretreatment packing material, pyrrole ethanol solution, sulfosalicylic acid, sodium anthraquinone sulfonate, deionized water and ammonium persulfate in step B3 is 1g:10mL:0.5mmol:1mmol:100mL:2.5mmol. The volume of the pyrrole ethanol solution is 2mL, which is prepared by dissolving 0.5mol of pyrrole in 1L of ethanol.

[0065] Example 3: A method for preparing a heavy-duty anti-corrosion and strong acid and alkali resistant modified nano-environmentally friendly coating, specifically including the following steps:

[0066] The film-forming base material, modified filler, functional additives and propylene glycol methyl ether were mixed evenly. Fatty alcohol polyoxyethylene ether was added at a speed of 2000 r / min and a temperature of 50℃. After stirring evenly for 50 min, deionized water was added and stirred for 40 min. Initiator 2959 and triallyl isocyanurate were added at a speed of 400 r / min, a temperature of 25℃ and in the dark. After stirring for 30 min, a heavy-duty anti-corrosion and strong acid and alkali resistant modified nano-environmentally friendly coating was obtained.

[0067] The weight ratio of the film-forming base material, modified filler, functional additive, propylene glycol methyl ether, fatty alcohol polyoxyethylene ether, initiator 2959, triallyl isocyanurate and deionized water mentioned in the steps is 60:8:8:2:2:0.3:3:60.

[0068] The film-forming base material is prepared by the following steps:

[0069] Step A1: Mix 2,4,6,8-tetramethylcyclotetrasiloxane, hexamethyldisiloxane and toluene evenly, stir at 200 r / min and 25°C, add potassium hydroxide and deionized water, and hydrolyze for 6 h. Then, react at 140°C and under nitrogen gas for 8 h to obtain pretreated polysiloxane.

[0070] Step A2: Mix the pretreated polysiloxane, tetrahydrofuran, ethynylcyclohexanol and allyl alcohol evenly. Stir and add a solution of isopropanol in chloroplatinic acid at a speed of 160 r / min, a temperature of 100℃ and a pH of 7, and react for 4 h to obtain the modified siloxane. Mix the modified siloxane and tetrahydrofuran evenly. Stir and add dibutyltin dilaurate, triethylamine and methylvinyl dichlorosilane at a speed of 300 r / min and a temperature of 60℃, and react for 3 h to obtain the film-forming base material.

[0071] The ratio of 2,4,6,8-tetramethylcyclotetrasiloxane, hexamethyldisiloxane, toluene, potassium hydroxide, and deionized water used in step A1 is 0.2 mol: 0.2 g: 54 g: 1.2 g: 0.8 mol, and the amount of 2,4,6,8-tetramethylcyclotetrasiloxane used is 3 mmol.

[0072] In step A2, the molar ratio of the silane-hydrogen bonds on the pretreated polysiloxane to the carbon-carbon double bonds on the allyl alcohol is 1:1.1. The amount of ethynylcyclohexanol used is 1% of the mass of allyl alcohol. The amount of isopropanol solution of chloroplatinic acid used is 0.5% of the mass of polysiloxane. The mass ratio of chloroplatinic acid to isopropanol is 0.01:9. The ratio of modified siloxane, tetrahydrofuran, dibutyltin dilaurate, triethylamine, and methylvinyldichlorosilane used is 1 mol: 20 mL: 0.2 g: 15 mL: 2.2 mol.

[0073] The functional additive is prepared by the following steps:

[0074] Ethanol and deionized water were mixed evenly, and under the conditions of 200 r / min, 70 °C and pH 7, tetraethyl orthosilicate and vinyltriethoxysilane were added and reacted for 10 h to obtain a pretreatment aid. The pretreatment aid was dispersed in tetrahydrofuran, and under the conditions of 300 r / min and 70 °C, hexadecyltrimethoxysilane was added and reacted for 12 h to obtain a functional aid.

[0075] The ratio of ethanol, deionized water, tetraethyl orthosilicate and vinyltriethoxysilane used in the step is 25g:10g:0.2mol:0.05mol, and the amount of hexadecyltrimethoxysilane used is 3% of the mass of the pretreatment aid.

[0076] The modified filler is prepared by the following steps:

[0077] Step B1: Basalt flakes were placed in a sodium hydroxide solution and reacted for 2 hours at a speed of 150 r / min and a temperature of 100℃ to obtain pretreated basalt flakes. Zirconium nitrate and deionized water were mixed evenly and stirred and added to the pretreated basalt flakes at a speed of 200 r / min, a temperature of 30℃ and a pH of 12. After reacting for 4 hours, the mixture was heated for 5 hours at a temperature of 700℃ to obtain modified basalt flakes.

[0078] Step B2: Stearic acid and ethanol are mixed evenly and stirred for 30 minutes at 300 r / min and 70℃. The pH is adjusted to 8, and modified basalt flakes are added while stirring at 180 r / min and 80℃. The reaction is carried out for 3 hours to obtain the pretreated filler. The pretreated filler is dispersed in an ethanol solution of ferric chloride and ultrasonically treated for 20 minutes at a frequency of 40 kHz to obtain the pretreated filler.

[0079] Step B3: Place the pretreated filler in an ethanol solution of pyrrole and stir for 50 min at a speed of 150 r / min and a temperature of 5℃. Add sulfosalicylic acid, sodium anthraquinone sulfonate and deionized water. Sonicate for 10 min at a frequency of 40 kHz. Then raise the temperature to 35℃, stir and add ammonium persulfate. React for 10 h to obtain the modified filler.

[0080] The ratio of basalt flakes to sodium hydroxide solution in step B1 is 3g:100mL, the molar concentration of sodium hydroxide solution is 4mol / L, and the ratio of zirconium nitrate, deionized water and pretreated basalt flakes is 1.49g:1500mL:0.6g.

[0081] The ratio of stearic acid, ethanol and modified basalt flakes in step B2 is 1g:200mL:3g, and the ratio of pretreatment filler and ferric chloride ethanol solution is 1g:10mL. The ferric chloride ethanol solution is prepared by dissolving 0.1mol of ferric chloride in 1L of ethanol.

[0082] The ratio of the pretreatment packing material, pyrrole ethanol solution, sulfosalicylic acid, sodium anthraquinone sulfonate, deionized water and ammonium persulfate in step B3 is 1g:10mL:0.5mmol:1mmol:100mL:2.5mmol. The volume of the pyrrole ethanol solution is 3mL, which is prepared by dissolving 0.5mol of pyrrole in 1L of ethanol.

[0083] Comparative Example 1: This comparative example uses a pretreatment agent instead of a functional agent, while the other steps are the same as in Example 1.

[0084] Comparative Example 2: This comparative example uses pretreated basalt flakes instead of modified basalt flakes, while the other steps are the same as in Example 1.

[0085] Comparative Example 3: This comparative example uses pretreated filler instead of modified filler, but the other steps are the same as in Example 1.

[0086] The waterproof UV-curable coatings prepared in Examples 1-3 and Comparative Examples 1-3 were applied to the surface of a 150mm×75mm×3mm steel plate and cured with ultraviolet light to obtain a 50μm thick cured coating.

[0087] A 5% sulfuric acid solution (pH≈1) was prepared to simulate an acidic environment, and a 10% sodium hydroxide solution (pH≈13) was prepared to simulate an alkaline environment. The coated steel plate was immersed in the reagents and placed at a constant temperature of 25℃, with the plate completely submerged and the liquid level 20 mm above the sample. The test time was controlled to be 168 hours. After the test, the sample was removed and washed with deionized water, and the changes in the coating appearance were recorded. The adhesion of the paint film before and after the test was determined according to GB / T9286-2021 "Paints and Varnishes - Cross-cut Test" standard; the pencil hardness before and after the test was determined according to GB / T6739-2006 "Paints and Varnishes - Pencil Method for Determination of Hardness of Paint Film" standard. The test results are shown in Table 1.

[0088] Electrochemical impedance spectroscopy (EIS) and polarization curves were performed using an Ivium multichannel electrochemical workstation. A three-electrode system was employed, with a Pt electrode as the counter electrode, an Ag / AgCl reference electrode, and a coated steel plate as the working electrode. A 3.5% NaCl solution was used as the test solution, with only the 10mm x 10mm coated working surface of the sample exposed. During testing, all samples were immersed in the solution for 30 minutes to reach a steady-state open-circuit potential, which was then used as a reference for EIS measurements.

[0089] Table 1

[0090] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Appearance changes The coating is free from bubbling, peeling, and discoloration. The coating is free from bubbling, peeling, and discoloration. The coating is free from bubbling, peeling, and discoloration. The coating is free from bubbling, peeling, and discoloration. The coating has a few bubbles, but no peeling or discoloration. The coating has some blistering, but no peeling or discoloration. Alkaline paint film adhesion Before: Level 0 After: Level 0 Before: Level 0 After: Level 0 Before: Level 0 After: Level 0 Before: Level 0 After: Level 0 Before: Level 0 After: Level 1 Before: Level 0 After: Level 1 alkaline pencil hardness Front: 4H Back: 4H Front: 4H Back: 4H Front: 4H Back: 4H Front: 4H Back: 4H Front: 4H Back: 3H Front: 4H Back: 3H Adhesion of acidic paint film Before: Level 0 After: Level 0 Before: Level 0 After: Level 0 Before: Level 0 After: Level 0 Before: Level 0 After: Level 0 Before: Level 0 After: Level 1 Before: Level 0 After: Level 1 Acid pencil hardness Front: 4H Back: 4H Front: 4H Back: 4H Front: 4H Back: 4H Front: 4H Back: 4H Front: 4H Back: 3H Front: 4H Back: 3H <![CDATA[Electrochemical impedance (Ω·cm 2 )]]> 12.68 13.13 13.87 12.47 10.36 10.68

[0091] Table 1 shows that the coatings prepared in Examples 1-3 did not exhibit significant changes in film adhesion and pencil hardness after immersion in acidic and alkaline test solutions for 168 hours, indicating that the invented coatings possess excellent resistance to strong acids and alkalis. Higher electrochemical impedance indicates greater difficulty for ions to penetrate the coating, resulting in lower corrosion current and stronger corrosion resistance. This invention demonstrates strong anti-corrosion capabilities and resistance to strong acids and alkalis.

[0092] The above description is merely an example and illustration of the concept of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the concept of the invention or exceed the scope defined in the claims, they should all fall within the protection scope of the present invention.

Claims

1. A method for preparing a heavy-duty anti-corrosion and strong acid and alkali resistant modified nano-environmentally friendly coating, characterized in that: Specifically, the steps include the following: The film-forming base material, modified filler, functional additives and propylene glycol methyl ether are mixed evenly, fatty alcohol polyoxyethylene ether is added, and after uniform stirring, deionized water is added and stirred. Initiator 2959 and triallyl isocyanurate are added and stirred to obtain a heavy-duty anti-corrosion and strong acid and alkali resistant modified nano-environmentally friendly coating. The weight ratio of the film-forming base material, modified filler, functional additive, propylene glycol methyl ether, fatty alcohol polyoxyethylene ether, initiator 2959, triallyl isocyanurate and deionized water mentioned in the steps is 50-60:6-8:6-8:2-4:2-3:0.3-0.5:3-5:60-80.

2. The preparation method of a heavy-duty anti-corrosion and strong acid and alkali resistant modified nano-environmentally friendly coating according to claim 1, characterized in that: The film-forming base material is prepared by the following steps: Step A1: Mix 2,4,6,8-tetramethylcyclotetrasiloxane, hexamethyldisiloxane and toluene evenly, stir and add potassium hydroxide and deionized water, hydrolyze and react to obtain pretreated polysiloxane. Step A2: Mix the pretreated polysiloxane, tetrahydrofuran, ethynylcyclohexanol and allyl alcohol evenly, stir and add isopropanol solution of chloroplatinic acid to react and obtain modified siloxane. Mix the modified siloxane and tetrahydrofuran and stir and add dibutyltin dilaurate, triethylamine and methyl vinyl dichlorosilane to react and obtain film-forming base material.

3. The preparation method of a heavy-duty anti-corrosion and strong acid and alkali resistant modified nano-environmentally friendly coating according to claim 2, characterized in that: The ratio of 2,4,6,8-tetramethylcyclotetrasiloxane, hexamethyldisiloxane, toluene, potassium hydroxide, and deionized water used in step A1 is 0.2 mol: 0.2 g: 54 g: 1.2 g: 0.8 mol.

4. The preparation method of a heavy-duty anti-corrosion and strong acid and alkali resistant modified nano-environmentally friendly coating according to claim 2, characterized in that: In step A2, the molar ratio of the silane-hydrogen bonds on the pretreated polysiloxane to the carbon-carbon double bonds on the allyl alcohol is 1:1.

1. The amount of ethynylcyclohexanol used is 0.5-1% of the mass of allyl alcohol. The amount of isopropanol solution of chloroplatinic acid used is 0.1-0.5% of the mass of polysiloxane. The mass ratio of chloroplatinic acid to isopropanol is 0.01:

9. The ratio of the amount of modified siloxane, tetrahydrofuran, dibutyltin dilaurate, triethylamine, and methylvinyldichlorosilane used is 1 mol: 20 mL: 0.2 g: 15 mL: 2.2 mol.

5. The preparation method of a heavy-duty anti-corrosion and strong acid and alkali resistant modified nano-environmentally friendly coating according to claim 1, characterized in that: The functional additive is prepared by the following steps: Ethanol and deionized water were mixed and stirred, and tetraethyl orthosilicate and vinyltriethoxysilane were added to react and prepare a pretreatment aid. The pretreatment aid was dispersed in tetrahydrofuran, stirred and hexadecyltrimethoxysilane was added to react and prepare a functional aid. The ratio of ethanol, deionized water, tetraethyl orthosilicate and vinyltriethoxysilane used in the step is 25g:10g:0.2mol:0.05mol, and the amount of hexadecyltrimethoxysilane used is 1-3% of the mass of the pretreatment aid.

6. The preparation method of a heavy-duty anti-corrosion and strong acid and alkali resistant modified nano-environmentally friendly coating according to claim 1, characterized in that: The modified filler is prepared by the following steps: Step B1: Basalt flakes are placed in sodium hydroxide solution and reacted to obtain pretreated basalt flakes. Zirconium nitrate and deionized water are mixed and stirred and added to the pretreated basalt flakes. After reaction, the mixture is heated to obtain modified basalt flakes. Step B2: Stearic acid and ethanol are mixed and stirred, pH is adjusted, modified basalt flakes are added and stirred to react, and pre-treated filler is obtained. The pre-treated filler is dispersed in ferric chloride ethanol solution and ultrasonically treated to obtain pre-treated filler. Step B3: Place the pretreated filler in an ethanol solution of pyrrole, stir, add sulfosalicylic acid, sodium anthraquinone sulfonate and deionized water, sonicate, heat, stir and add ammonium persulfate to react and obtain the modified filler.

7. The preparation method of a heavy-duty anti-corrosion and strong acid and alkali resistant modified nano-environmentally friendly coating according to claim 6, characterized in that: The ratio of basalt flakes to sodium hydroxide solution in step B1 is 3g:100mL, and the ratio of zirconium nitrate, deionized water and pretreated basalt flakes is 1.49g:1500mL:0.6g.

8. The preparation method of a heavy-duty anti-corrosion and strong acid and alkali resistant modified nano-environmentally friendly coating according to claim 6, characterized in that: The ratio of stearic acid, ethanol and modified basalt flakes in step B2 is 1g:200mL:3g, and the ratio of pretreatment filler and ferric chloride ethanol solution is 1g:10mL.

9. The preparation method of a heavy-duty anti-corrosion and strong acid and alkali resistant modified nano-environmentally friendly coating according to claim 6, characterized in that: The ratio of the pretreatment filler, pyrrole ethanol solution, sulfosalicylic acid, sodium anthraquinone sulfonate, deionized water and ammonium persulfate described in step B3 is 1g:10mL:0.5mmol:1mmol:100mL:2.5mmol.

10. A heavy-duty anti-corrosion and strong acid and alkali resistant modified nano-environmentally friendly coating, characterized in that: Prepared according to any one of the preparation methods described in claims 1-9.