Long-acting anti-corrosion coating for heavy corrosion working condition as well as preparation method and application of long-acting anti-corrosion coating

Abstract

The invention discloses a long-acting anti-corrosion coating for a heavy corrosion working condition as well as a preparation method and application thereof, and belongs to the technical field of coating preparation. The invention relates to a long-acting anticorrosive paint for heavy corrosion working conditions. The paint is prepared from the following components in parts by weight: 25-39 parts of epoxy resin, 12-22 parts of fluorocarbon resin, 12-21 parts of zinc powder, 5-9 parts of zinc phosphate, 10-18 parts of talcum powder, 2-7 parts of nano silicon dioxide, 1-5 parts of an organic corrosion inhibitor, 0.8-2.3 parts of an adhesion promoter, 1-4 parts of a dispersing agent, 1-3 parts of a flatting agent, 1-3 parts of a defoaming agent and 12-24 parts of ethylene glycol butyl ether. The anticorrosive paint prepared from the substances has excellent long-acting anticorrosive properties such as high temperature resistance, acid and alkali resistance, oxidation resistance and the like, and is suitable for infrastructures in the fields of petroleum, chemical industry, steel manufacturing, port facilities, wind power generation, heavy mechanical equipment, military industry and aerospace.

Description

Technical Field

[0001] This invention belongs to the field of anti-corrosion coating preparation technology, specifically relating to a long-lasting anti-corrosion coating for heavy corrosion conditions, its preparation method, and its application. Background Technology

[0002] Under severe corrosion conditions, traditional anti-corrosion coatings often fail rapidly due to their weak corrosion resistance and short protective life. This failure not only leads to frequent equipment downtime for maintenance, increasing operating costs, but may also cause significant safety hazards such as reduced structural strength and media leakage, resulting in incalculable economic losses. Taking typical fields such as steel manufacturing, chemical industry, marine engineering, and thermal power as examples, metal structures are exposed to extreme corrosive environments such as strong acids, strong alkalis, high salt spray, and high-temperature alternating conditions for a long time, and their corrosion rate can be several to tens of times that of conventional operating conditions. For example, the sector section, crystallizer, bending section, and vibrating table of the continuous casting machine in a steelmaking plant are important equipment in the steelmaking process. During the billet casting process, the acidic vapor generated by the high-temperature quenching water during billet pulling contains high concentrations of chlorine, sulfur, carbon dioxide, water vapor, and other substances. The local confined space is not ventilated and is in a high-temperature state for a long time, creating an extremely harsh corrosive environment. The sector section equipment is severely corroded, mainly due to the influence of acidic gases and high-temperature steam, resulting in a large accumulation of rust and steel slag on the surface of the equipment, which seriously affects the service life of the equipment.

[0003] Chinese invention patent CN110655855B discloses an industrial heavy-duty anti-corrosion, long-lasting, weather-resistant water-based acrylic polyurethane anti-corrosion coating and its preparation method. This industrial heavy-duty anti-corrosion water-based acrylic polyurethane coating, after 3000 hours of accelerated artificial aging, shows no blistering, cracking, or peeling; it exhibits Grade 1 chalking, Grade 1 discoloration, and Grade 1 gloss loss. It shows no abnormalities in acid resistance (50g / L H2SO4) for 240 hours; no abnormalities in alkali resistance (20g / L NaOH) for 240 hours; no abnormalities in salt water resistance (3% NaCl) for 500 hours; and no blistering, rusting, or peeling in a neutral salt spray test for 2000 hours. Furthermore, the coating possesses excellent physical and mechanical properties and good application adaptability. Its performance meets the requirements of solvent-based industrial heavy-duty anti-corrosion acrylic polyurethane coatings, surpasses the performance of ordinary water-based acrylic polyurethane coatings, satisfies the anti-corrosion performance requirements of industrial heavy-duty anti-corrosion topcoats, and has broad application prospects. The manufacturing method of this industrial heavy-duty anti-corrosion, long-lasting, weather-resistant waterborne acrylic polyurethane anti-corrosion coating is simple, requires no special equipment, and has good application prospects. It is suitable for heavy-duty industrial anti-corrosion applications such as steel structures in petroleum refining plants, storage tanks, and bridges and docks in C3 (medium) to CX (extreme) corrosive environments, with a wide range of applications. However, it still has technical limitations in industrial fields and infrastructure with extremely high corrosion protection requirements and harsh environments, necessitating further improvements to its formulation. Summary of the Invention

[0004] The purpose of this invention is to provide a long-lasting anti-corrosion coating for heavy corrosion conditions, its preparation method, and its application, in order to solve the technical problem that existing technologies are not applicable to industrial fields and infrastructure with extremely high corrosion protection requirements and extremely harsh environments, and that further improvements to their formulation components are needed.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This invention provides a long-lasting anti-corrosion coating for use in heavily corrosive environments, comprising the following components by weight: 25-39 parts epoxy resin, 12-22 parts fluorocarbon resin, 12-21 parts zinc powder, 5-9 parts zinc phosphate, 10-18 parts talc, 2-7 parts nano silica, 1-5 parts organic corrosion inhibitor, 0.8-2.3 parts adhesion promoter, 1-4 parts dispersant, 1-3 parts leveling agent, 1-3 parts defoamer, and 12-24 parts ethylene glycol butyl ether.

[0007] Preferably, the method for preparing the organic corrosion inhibitor includes the following steps:

[0008] Q1: At room temperature, [1,2,4]thiazole[1,5-a]pyridine-6-carboxaldehyde was added to a container, followed by a mixed solution of tetrahydrofuran and isopropanol. After stirring evenly, diphenyl phosphate ((6-methylpyridin-2-yl)(phenylamino)methyl)phosphate and cesium carbonate were added. After reacting at room temperature, hydrochloric acid was added. After the reaction, methyl tert-butyl ether was added. After stirring evenly, the mixture was separated, extracted, pH adjusted, and the precipitated solid was filtered and dried to obtain compound 1.

[0009] Q2: At room temperature, compound 1 was added to a container, followed by dimethyl sulfoxide. After stirring to dissolve, hydrobromic acid was added, the mixture was heated to react, cooled, pH was adjusted, extracted, washed, dried, filtered, and dried under reduced pressure to obtain compound 2.

[0010] Q3: At room temperature, compound 2 was added to a container containing methanol and stirred. Then, ammonium acetate, phthalimide acetaldehyde and methyl tert-butyl ether were added in sequence. After heating and reacting, the mixture was cooled, the pH was adjusted, extracted, washed, dried, filtered, dried under reduced pressure, and purified to obtain an organic corrosion inhibitor.

[0011] The synthesis reaction formula for the organic corrosion inhibitor in the above process is as follows:

[0012]

[0013] The mass spectrometry analysis results of compound 1 were: m / z: 252.10 (100.0%), 253.10 (16.6%), 254.11 (1.3%); the mass spectrometry analysis results of compound 2 were: m / z: 266.08 (100.0%), 267.08 (16.7%), 268.09 (1.1%); the mass spectrometry analysis results of the organic corrosion inhibitor were: m / z: 435.14 (100.0%), 436.15 (26.2%), 437.15 (3.7%), 436.14 (2.6%).

[0014] Preferably, in Q1, the ratio of [1,2,4]thiazole[1,5-a]pyridine-6-carboxaldehyde, tetrahydrofuran, isopropanol, ((6-methylpyridin-2-yl)(phenylamino)methyl)diphenyl phosphate, cesium carbonate, and methyl tert-butyl ether is (12.21-14.72) g : (220-260) mL : (50-70) mL : (42.28-43.88) g : (14.28-16.52) g : (400-410) mL, the concentration of hydrochloric acid is 1 mol / L, and the pH is adjusted to 7-8 with saturated sodium bicarbonate.

[0015] Preferably, in Q2, the ratio of compound 1, dimethyl sulfoxide, and hydrobromic acid is (5.88-6.21) g : (208-224) mL : (12-15) mL, the volume fraction of hydrobromic acid is 48 wt%, the reaction is heated to 70-75℃ for 1-2 h, saturated sodium bicarbonate is added to adjust the pH to 7-7.4, the mixture is extracted with dichloromethane, washed with distilled water, washed again with saturated sodium chloride solution, and dried with anhydrous sodium sulfate.

[0016] Preferably, in Q3, the ratio of compound 2, methanol, ammonium acetate, phthalimide acetaldehyde, and methyl tert-butyl ether is (21.2-23.6) mL : (180-200) mL : (18.8-19.6) mL : (31.3-35.9) mL : (140-160) mL. The reaction temperature is 50-55℃, the reaction time is 10-12 h, the pH is adjusted to 8-8.3 with sodium bicarbonate aqueous solution, the mixture is extracted with ethyl acetate, washed with distilled water, and then washed with saturated sodium chloride solution.

[0017] Preferably, the method for preparing the adhesion promoter includes the following steps:

[0018] S1: Add 4,4'-dipyridine disulfide to a container containing dichloromethane, stir to dissolve, then add dichloromethane containing 3-mercaptopropyltriethoxysilane dropwise, controlling the dropping rate. After the addition is complete, seal and stir the reaction. After the reaction is complete, rotary evaporate, purify, and vacuum dry to obtain product a.

[0019] S2: Add product a to a container containing dichloromethane, stir and mix, then add mercapto-polyethylene glycol-azide, stir and react. After the reaction is complete, purify to obtain the adhesion promoter.

[0020] The synthesis reaction formula for the adhesion promoter in the above process is as follows:

[0021]

[0022] The mass spectrometry analysis results of product a were: m / z: 347.10 (100.0%), 348.11 (15.5%), 349.10 (12.6%), 348.10 (7.0%), 349.11 (2.8%), 350.10 (2.5%); the mass spectrometry analysis results of the adhesion promoter were: m / z: 471.19 (100.0%), 472.19 (26.4%), 473.19 (15.2%), 474.19 (2.6%), 473.20 (1.7%).

[0023] Preferably, in S1, the ratio of 4,4'-dipyridine disulfide to 3-mercaptopropyltriethoxysilane is (4.48-4.66) g : (9.88-10.21) g, the dropping rate is controlled at 2 drops / s, and the reaction is carried out under sealed stirring for 40-50 h.

[0024] Preferably, in S2, the ratio of product a, dichloromethane, and mercapto-polyethylene glycol-azide is (0.212-0.258) g : (10-14) mL : (0.322-0.358) g, and the reaction is stirred for 40-50 h.

[0025] Preferably, the method for preparing a long-lasting anti-corrosion coating for heavily corrosive conditions includes the following steps:

[0026] Step 1: Add ethylene glycol butyl ether to the container, then slowly add epoxy resin and fluorocarbon resin. After stirring and mixing, add dispersant, organic corrosion inhibitor and adhesion promoter. Stir evenly to obtain the mixture.

[0027] Step 2: Add zinc phosphate, talc powder and nano silica to the mixture in sequence, stir evenly, grind, then slowly add zinc powder, stir, add leveling agent and defoamer, disperse evenly, mature, filter, and obtain a long-lasting anti-corrosion coating for heavy corrosion conditions.

[0028] As a preferred option, a long-lasting anti-corrosion coating for heavy corrosion conditions is prepared and mainly used in petroleum, chemical, steel manufacturing, port facilities, wind power generation, heavy machinery and equipment, military and aerospace special fields.

[0029] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0030] 1. The present invention adds organic corrosion inhibitors and adhesion promoters to the preparation process of children's anti-corrosion coatings, which can effectively improve their anti-corrosion performance, adhesion and long-lasting effect.

[0031] 2. The organic corrosion inhibitor obtained in this invention is added to the preparation process of anti-corrosion coatings, which can effectively improve the anti-corrosion performance of the coatings, extend the service life of the coatings, and enhance the durability of the coatings in harsh environments. This is because the heterocyclic structure and polar functional groups contained in the organic corrosion inhibitor can form a dense monomolecular protective film on the metal surface through chemical adsorption, effectively blocking the penetration of water, oxygen and corrosion ions. At the same time, the organic corrosion inhibitor can undergo coordination reaction with metal ions to generate stable complexes that cover the active sites, inhibiting anodic metal dissolution and cathodic oxygen reduction reaction, thereby reducing the electrochemical corrosion rate.

[0032] 3. The present invention adds the prepared adhesion promoter to the preparation process of anti-corrosion coating, which can effectively improve the overall performance and service life of the anti-corrosion coating. The adhesion promoter, as a "bridge molecule", forms a covalent bond with the substrate through its siloxane end and buffers stress with a flexible chain, which greatly improves the adhesion, flexibility and durability of the coating. At the same time, it works synergistically with organic corrosion inhibitors to build a dense protective layer at the interface, block corrosion, and significantly enhance the overall performance and service life of the anti-corrosion coating. Detailed Implementation

[0033] 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.

[0034] Example 1: This example discloses a method for preparing an organic corrosion inhibitor, including the following steps:

[0035] Q1: At room temperature, 13.46 g of [1,2,4]thiazole[1,5-a]pyridine-6-carboxaldehyde was added to a container, followed by 240 mL of a mixed solution of tetrahydrofuran and 60 mL of isopropanol. After stirring evenly, 43.04 g of ((6-methylpyridin-2-yl)(phenylamino)methyl)diphenyl phosphate and 15.85 g of cesium carbonate were added. After reacting at room temperature, 400 mL of 1 mol / L hydrochloric acid was added. After the reaction, 405 mL of methyl tert-butyl ether was added. After stirring evenly, the mixture was separated, extracted, and the pH was adjusted to 7 with saturated sodium bicarbonate. The precipitated solid was filtered, dried, and compound 1 was obtained.

[0036] Q2: At room temperature, 6.04 g of compound 1 was added to a container, followed by 216 mL of dimethyl sulfoxide. After stirring and dissolving, 13.5 mL of 48 wt% hydrobromic acid was added. The mixture was heated to 70 °C and reacted for 2 h. After cooling, saturated sodium bicarbonate was added to adjust the pH to 7. The mixture was extracted with dichloromethane, washed with distilled water, and then washed again with saturated sodium chloride solution. The mixture was dried with anhydrous sodium sulfate, filtered, and dried under reduced pressure to obtain compound 2.

[0037] Q3: At room temperature, 22.4 mL of compound 2 was added to a container containing 190 mL of methanol. After stirring and mixing, 19.2 mL of ammonium acetate, 33.5 mL of phthalimide acetaldehyde, and 150 mL of methyl tert-butyl ether were added sequentially. The mixture was heated at 55 °C for 12 h, cooled, and the pH was adjusted to 8 by adding saturated sodium bicarbonate. The mixture was extracted with ethyl acetate, washed with distilled water, washed with saturated sodium chloride solution, dried, filtered, dried under reduced pressure, and purified to obtain the organic corrosion inhibitor.

[0038] This embodiment discloses a method for preparing an adhesion promoter, including the following steps:

[0039] S1: 4.57 g of 4,4'-dipyridine disulfide was added to a container containing 50 mL of dichloromethane. After stirring and dissolving, 30 mL of dichloromethane containing 10.04 g of 3-mercaptopropyltriethoxysilane was added dropwise at a rate of 2 drops / s. After the addition was complete, the container was sealed and stirred for 48 h. After the reaction was completed, the product was purified by rotary evaporation and vacuum dried to obtain product a.

[0040] S2: Add 0.235g of product a to a container containing 12mL of dichloromethane, stir and mix, then add 0.335g of mercapto-polyethylene glycol-azide, stir and react for 48h. After the reaction is complete, purify to obtain the adhesion promoter.

[0041] This embodiment discloses a long-lasting anti-corrosion coating for heavy corrosion conditions, which is composed of the following components by weight: 32 parts bisphenol A type epoxy resin E-44, 17 parts polyvinylidene fluoride resin, 16.5 parts zinc powder, 7 parts zinc phosphate, 14 parts talc powder, 4.5 parts nano silica, 3 parts organic corrosion inhibitor, 1.5 parts adhesion promoter, 2.5 parts ammonium polyacrylate, 2 parts leveling agent BYK-333, 2 parts polydimethylsiloxane and 18 parts ethylene glycol butyl ether.

[0042] This embodiment discloses a method for preparing a long-lasting anti-corrosion coating for heavily corrosive conditions, including the following steps:

[0043] Step 1: Add ethylene glycol butyl ether to the container, then slowly add bisphenol A type epoxy resin E-44 and polyvinylidene fluoride resin. After stirring and mixing, add ammonium polyacrylate, organic corrosion inhibitor and adhesion promoter. After stirring evenly, a mixture is obtained.

[0044] Step 2: Add zinc phosphate, talc powder and nano silica to the mixture in sequence, stir evenly, grind, then slowly add zinc powder, stir, add leveling agent BYK-333 and polydimethylsiloxane, disperse evenly, mature, filter, and obtain a long-lasting anti-corrosion coating for heavy corrosion conditions.

[0045] Example 2: This example discloses a method for preparing an organic corrosion inhibitor, including the following steps:

[0046] Q1: At room temperature, 12.21 g of [1,2,4]thiazole[1,5-a]pyridine-6-carboxaldehyde was added to a container, followed by 220 mL of a mixed solution of tetrahydrofuran and 70 mL of isopropanol. After stirring evenly, 42.28 g of ((6-methylpyridin-2-yl)(phenylamino)methyl)diphenyl phosphate and 14.28 g of cesium carbonate were added. After reacting at room temperature, 400 mL of 1 mol / L hydrochloric acid was added. After the reaction, 410 mL of methyl tert-butyl ether was added. After stirring evenly, the mixture was separated, extracted, and the pH was adjusted to 7 with saturated sodium bicarbonate. The precipitated solid was filtered, dried, and compound 1 was obtained.

[0047] Q2: At room temperature, 5.88 g of compound 1 was added to a container, followed by 208 mL of dimethyl sulfoxide. After stirring and dissolving, 15 mL of 48 wt% hydrobromic acid was added. The mixture was heated to 70 °C and reacted for 2 h. After cooling, saturated sodium bicarbonate was added to adjust the pH to 7. The mixture was extracted with dichloromethane, washed with distilled water, and then washed with saturated sodium chloride solution. The mixture was dried with anhydrous sodium sulfate, filtered, and dried under reduced pressure to obtain compound 2.

[0048] Q3: At room temperature, 21.2 mL of compound 2 was added to a container containing 180 mL of methanol. After stirring and mixing, 19.6 mL of ammonium acetate, 31.3 mL of phthalimide acetaldehyde, and 140 mL of methyl tert-butyl ether were added sequentially. The mixture was heated at 55 °C for 12 h, cooled, and the pH was adjusted to 8 by adding saturated sodium bicarbonate. The mixture was extracted with ethyl acetate, washed with distilled water, washed with saturated sodium chloride solution, dried, filtered, dried under reduced pressure, and purified to obtain the organic corrosion inhibitor.

[0049] This embodiment discloses a method for preparing an adhesion promoter, including the following steps:

[0050] S1: 4.48 g of 4,4'-dipyridine disulfide was added to a container containing 50 mL of dichloromethane. After stirring and dissolving, 30 mL of dichloromethane containing 9.88 g of 3-mercaptopropyltriethoxysilane was added dropwise at a rate of 2 drops / s. After the addition was complete, the container was sealed and stirred for 48 h. After the reaction was completed, the product was purified by rotary evaporation and vacuum dried to obtain product a.

[0051] S2: Add 0.212g of product a to a container containing 14mL of dichloromethane, stir and mix, then add 0.322g of mercapto-polyethylene glycol-azide, stir and react for 48h. After the reaction is complete, purify to obtain the adhesion promoter.

[0052] This embodiment discloses a long-lasting anti-corrosion coating for heavy corrosion conditions, which is composed of the following components by weight: 25 parts bisphenol A type epoxy resin E-51, 12 parts fluoroethylene-vinyl ether copolymer, 12 parts zinc powder, 5 parts zinc phosphate, 18 parts talc powder, 2 parts nano silica, 1 part organic corrosion inhibitor, 0.8 parts adhesion promoter, 1 part polyether phosphate, 1 part leveling agent BYK-354, 3 parts polyether modified polysiloxane and 24 parts ethylene glycol butyl ether.

[0053] This embodiment discloses a method for preparing a long-lasting anti-corrosion coating for heavily corrosive conditions, including the following steps:

[0054] Step 1: Add ethylene glycol butyl ether to the container, then slowly add bisphenol A type epoxy resin E-51 and fluorinated vinyl ether copolymer, stir and mix, then add polyether phosphate, organic corrosion inhibitor and adhesion promoter, stir evenly to obtain the mixture;

[0055] Step 2: Add zinc phosphate, talc powder and nano silica to the mixture in sequence, stir evenly, grind, then slowly add zinc powder, stir, add leveling agent BYK-354 and polyether modified polysiloxane, disperse evenly, mature, filter, and obtain a long-lasting anti-corrosion coating for heavy corrosion conditions.

[0056] Example 3: This example discloses a method for preparing an organic corrosion inhibitor, including the following steps:

[0057] Q1: At room temperature, 14.72 g of [1,2,4]thiazole[1,5-a]pyridine-6-carboxaldehyde was added to a container, followed by 260 mL of a mixed solution of tetrahydrofuran and 50 mL of isopropanol. After stirring evenly, 43.88 g of ((6-methylpyridin-2-yl)(phenylamino)methyl)diphenyl phosphate and 16.52 g of cesium carbonate were added. After reacting at room temperature, 400 mL of 1 mol / L hydrochloric acid was added. After the reaction, 400 mL of methyl tert-butyl ether was added. After stirring evenly, the mixture was separated, extracted, and the pH was adjusted to 7 with saturated sodium bicarbonate. The precipitated solid was filtered, dried, and compound 1 was obtained.

[0058] Q2: At room temperature, 6.21 g of compound 1 was added to a container, followed by 224 mL of dimethyl sulfoxide. After stirring and dissolving, 12 mL of 48 wt% hydrobromic acid was added. The mixture was heated to 70 °C and reacted for 2 h. After cooling, saturated sodium bicarbonate was added to adjust the pH to 7. The mixture was extracted with dichloromethane, washed with distilled water, and then washed with saturated sodium chloride solution. The mixture was dried with anhydrous sodium sulfate, filtered, and dried under reduced pressure to obtain compound 2.

[0059] Q3: At room temperature, 23.6 mL of compound 2 was added to a container containing 200 mL of methanol. After stirring and mixing, 18.8 mL of ammonium acetate, 35.9 mL of phthalimide acetaldehyde, and 160 mL of methyl tert-butyl ether were added sequentially. The mixture was heated at 55 °C for 12 h, cooled, and the pH was adjusted to 8 by adding saturated sodium bicarbonate. The mixture was extracted with ethyl acetate, washed with distilled water, washed with saturated sodium chloride solution, dried, filtered, dried under reduced pressure, and purified to obtain the organic corrosion inhibitor.

[0060] This embodiment discloses a method for preparing an adhesion promoter, including the following steps:

[0061] S1: 4.66 g of 4,4'-dipyridine disulfide was added to a container containing 50 mL of dichloromethane. After stirring and dissolving, 30 mL of dichloromethane containing 10.21 g of 3-mercaptopropyltriethoxysilane was added dropwise at a rate of 2 drops / s. After the addition was complete, the container was sealed and stirred for 48 h. After the reaction was completed, the product was rotary evaporated, purified, and dried under vacuum to obtain product a.

[0062] S2: Add 0.258g of product a to a container containing 10mL of dichloromethane, stir and mix, then add 0.358g of mercapto-polyethylene glycol-azide, stir and react for 48h. After the reaction is complete, purify to obtain the adhesion promoter.

[0063] This embodiment discloses a long-lasting anti-corrosion coating for use in heavily corrosive environments, which is composed of the following components by weight: 39 parts bisphenol A type epoxy resin E-20, 22 parts polyvinylidene fluoride, 21 parts zinc powder, 9 parts zinc phosphate, 10 parts talc powder, 7 parts nano silica, 5 parts organic corrosion inhibitor, 2.3 parts adhesion promoter, 4 parts dispersant BYK-161, 3 parts leveling agent BYK-358, 1 part polydimethylsiloxane, and 12 parts ethylene glycol butyl ether.

[0064] This embodiment discloses a method for preparing a long-lasting anti-corrosion coating for heavily corrosive conditions, including the following steps:

[0065] Step 1: Add ethylene glycol butyl ether to the container, then slowly add bisphenol A type epoxy resin E-20 and polyvinylidene fluoride, stir and mix, then add dispersant BYK-161, organic corrosion inhibitor and adhesion promoter, stir evenly to obtain the mixture;

[0066] Step 2: Add zinc phosphate, talc powder and nano silica to the mixture in sequence, stir evenly, grind, then slowly add zinc powder, stir, add leveling agent BYK-358 and polydimethylsiloxane, disperse evenly, mature, filter, and obtain a long-lasting anti-corrosion coating for heavy corrosion conditions.

[0067] Example 4: This example discloses a method for preparing an organic corrosion inhibitor, including the following steps:

[0068] Q1: At room temperature, 12.88 g of [1,2,4]thiazole[1,5-a]pyridine-6-carboxaldehyde was added to a container, followed by 230 mL of a mixed solution of tetrahydrofuran and 55 mL of isopropanol. After stirring evenly, 42.62 g of ((6-methylpyridin-2-yl)(phenylamino)methyl)diphenyl phosphate and 15.07 g of cesium carbonate were added. After reacting at room temperature, 402 mL of 1 mol / L hydrochloric acid was added. After reacting, 405 mL of methyl tert-butyl ether was added. After stirring evenly, the mixture was separated, extracted, and the pH was adjusted to 7 with saturated sodium bicarbonate. The precipitated solid was filtered, dried, and compound 1 was obtained.

[0069] Q2: At room temperature, 5.94 g of compound 1 was added to a container, followed by 212 mL of dimethyl sulfoxide. After stirring and dissolving, 13 mL of 48 wt% hydrobromic acid was added. The mixture was heated to 70 °C and reacted for 2 h. After cooling, saturated sodium bicarbonate was added to adjust the pH to 7. The mixture was extracted with dichloromethane, washed with distilled water, and then washed with saturated sodium chloride solution. The mixture was dried with anhydrous sodium sulfate, filtered, and dried under reduced pressure to obtain compound 2.

[0070] Q3: At room temperature, 21.8 mL of compound 2 was added to a container containing 185 mL of methanol. After stirring and mixing, 19.1 mL of ammonium acetate, 32.4 mL of phthalimide acetaldehyde, and 145 mL of methyl tert-butyl ether were added sequentially. The mixture was heated at 55 °C for 12 h, cooled, and the pH was adjusted to 8 by adding saturated sodium bicarbonate. The mixture was extracted with ethyl acetate, washed with distilled water, washed with saturated sodium chloride solution, dried, filtered, dried under reduced pressure, and purified to obtain the organic corrosion inhibitor.

[0071] This embodiment discloses a method for preparing an adhesion promoter, including the following steps:

[0072] S1: 4.51 g of 4,4'-dipyridine disulfide was added to a container containing 50 mL of dichloromethane. After stirring and dissolving, 30 mL of dichloromethane containing 9.96 g of 3-mercaptopropyltriethoxysilane was added dropwise at a rate of 2 drops / s. After the addition was complete, the container was sealed and stirred for 48 h. After the reaction was completed, the product was purified by rotary evaporation and vacuum dried to obtain product a.

[0073] S2: Add 0.227g of product a to a container containing 11mL of dichloromethane, stir and mix, then add 0.331g of mercapto-polyethylene glycol-azide, stir and react for 48h. After the reaction is complete, purify to obtain the adhesion promoter.

[0074] This embodiment discloses a long-lasting anti-corrosion coating for use in heavily corrosive environments, comprising the following components by weight: 28 parts phenolic epoxy resin F-44, 16 parts polyvinylidene fluoride, 14 parts zinc powder, 6 parts zinc phosphate, 12 parts talc powder, 5 parts nano silica, 2 parts organic corrosion inhibitor, 1.2 parts adhesion promoter, 2 parts dispersant BYK-163, 1.5 parts leveling agent BYK-354, 1.5 parts polyether-modified polysiloxane, and 16 parts ethylene glycol butyl ether.

[0075] This embodiment discloses a method for preparing a long-lasting anti-corrosion coating for heavily corrosive conditions, including the following steps:

[0076] Step 1: Add ethylene glycol butyl ether to the container, then slowly add phenolic epoxy resin F-44 and polyvinylidene fluoride. After stirring and mixing, add dispersant BYK-163, organic corrosion inhibitor and adhesion promoter. Stir evenly to obtain the mixture.

[0077] Step 2: Add zinc phosphate, talc powder and nano silica to the mixture in sequence, stir evenly, grind, then slowly add zinc powder, stir, add leveling agent BYK-354 and polyether modified polysiloxane, disperse evenly, mature, filter, and obtain a long-lasting anti-corrosion coating for heavy corrosion conditions.

[0078] Example 5: This example discloses a method for preparing an organic corrosion inhibitor, including the following steps:

[0079] Q1: At room temperature, 14.15 g of [1,2,4]thiazole[1,5-a]pyridine-6-carboxaldehyde was added to a container, followed by 250 mL of a mixed solution of tetrahydrofuran and 65 mL of isopropanol. After stirring evenly, 43.46 g of ((6-methylpyridin-2-yl)(phenylamino)methyl)diphenyl phosphate and 16.11 g of cesium carbonate were added. After reacting at room temperature, 400 mL of 1 mol / L hydrochloric acid was added. After the reaction, 408 mL of methyl tert-butyl ether was added. After stirring evenly, the mixture was separated, extracted, and the pH was adjusted to 7 with saturated sodium bicarbonate. The precipitated solid was filtered, dried, and compound 1 was obtained.

[0080] Q2: At room temperature, 6.16 g of compound 1 was added to a container, followed by 221 mL of dimethyl sulfoxide. After stirring and dissolving, 14 mL of 48 wt% hydrobromic acid was added. The mixture was heated to 70 °C and reacted for 2 h. After cooling, saturated sodium bicarbonate was added to adjust the pH to 7. The mixture was extracted with dichloromethane, washed with distilled water, and then washed with saturated sodium chloride solution. The mixture was dried with anhydrous sodium sulfate, filtered, and dried under reduced pressure to obtain compound 2.

[0081] Q3: At room temperature, 22.9 mL of compound 2 was added to a container containing 195 mL of methanol. After stirring and mixing, 19.5 mL of ammonium acetate, 34.7 mL of phthalimide acetaldehyde, and 155 mL of methyl tert-butyl ether were added sequentially. The mixture was heated at 55 °C for 12 h, cooled, and the pH was adjusted to 8 by adding saturated sodium bicarbonate. The mixture was extracted with ethyl acetate, washed with distilled water, washed with saturated sodium chloride solution, dried, filtered, dried under reduced pressure, and purified to obtain the organic corrosion inhibitor.

[0082] This embodiment discloses a method for preparing an adhesion promoter, including the following steps:

[0083] S1: 4.61 g of 4,4'-dipyridine disulfide was added to a container containing 50 mL of dichloromethane. After stirring and dissolving, 30 mL of dichloromethane containing 10.18 g of 3-mercaptopropyltriethoxysilane was added dropwise at a rate of 2 drops / s. After the addition was complete, the container was sealed and stirred for 48 h. After the reaction was completed, the product was purified by rotary evaporation and vacuum dried to obtain product a.

[0084] S2: Add 0.246g of product a to a container containing 13mL of dichloromethane, stir and mix, then add 0.347g of mercapto-polyethylene glycol-azide, stir and react for 48h. After the reaction is complete, purify to obtain the adhesion promoter.

[0085] This embodiment discloses a long-lasting anti-corrosion coating for heavy corrosion conditions, which is composed of the following components by weight: 34 parts phenolic epoxy resin F-48, 20 parts fluoroethylene-vinyl ether copolymer, 19 parts zinc powder, 8 parts zinc phosphate, 16 parts talc powder, 6 parts nano silica, 4 parts organic corrosion inhibitor, 2.1 parts adhesion promoter, 3 parts lecithin, 2.5 parts leveling agent BYK-333, 2.5 parts polydimethylsiloxane, and 22 parts ethylene glycol butyl ether.

[0086] This embodiment discloses a method for preparing a long-lasting anti-corrosion coating for heavily corrosive conditions, including the following steps:

[0087] Step 1: Add ethylene glycol butyl ether to the container, then slowly add phenolic epoxy resin F-48 and fluoroethylene-vinyl ether copolymer, stir and mix, then add lecithin, organic corrosion inhibitor and adhesion promoter, stir evenly to obtain the mixture;

[0088] Step 2: Add zinc phosphate, talc powder and nano silica to the mixture in sequence, stir evenly, grind, then slowly add zinc powder, stir, add leveling agent BYK-333 and polydimethylsiloxane, disperse evenly, mature, filter, and obtain a long-lasting anti-corrosion coating for heavy corrosion conditions.

[0089] Comparative Example 1: Compared with Example 1, Comparative Example 1 did not add organic corrosion inhibitors during the preparation of long-lasting anti-corrosion coating, and all other conditions remained unchanged.

[0090] Comparative Example 2: Compared with Example 1, Comparative Example 2 did not add an adhesion promoter during the preparation of the long-lasting anti-corrosion coating, and all other conditions remained unchanged.

[0091] Performance testing:

[0092] The long-lasting anti-corrosion coatings prepared in Examples 1-5 and Comparative Examples 1-2 were subjected to performance tests. Low-carbon steel plates (Q235, 150mm × 70mm) were rust-removed, cleaned, and dried before the anti-corrosion coatings were applied. After curing, the samples were obtained for testing. The adhesion of the samples was tested according to GB / T 5210-2006, and the corrosion resistance was tested according to GB / T 30790.6-2014. The test results are shown in Table 1.

[0093] Table 1

[0094]

[0095] As can be seen from the test results in Table 1, anti-corrosion coatings with excellent anti-corrosion properties and adhesion can be prepared by using the methods in Examples 1-5. The samples prepared in Examples 1-5 contained two key additives, achieving optimal synergistic effects. The high adhesion was due to the chemical anchoring of the adhesion promoter, while the excellent corrosion resistance was the result of the synergistic effect of the chemical passivation of the organic corrosion inhibitor, the cathodic protection of the zinc powder, and the complete physical barrier ensured by the adhesion promoter. Comparing Comparative Example 1 with Examples 1-5, the adhesion decreased because the lack of a protective film formed at the interface by the organic corrosion inhibitor allowed the corrosive medium to easily penetrate the interface, weakening the bonding force and reducing corrosion resistance. This demonstrates that in a strong chemical corrosion environment, without the protection of the organic corrosion inhibitor, the physical barrier and sacrificial anode alone are insufficient for effective protection. Comparing Comparative Example 2 with Examples 1-5, the adhesion decreased significantly, demonstrating that the adhesion promoter has a significant impact on the bonding strength. The corrosion resistance was "medium" and "low," indicating that even with the presence of the organic corrosion inhibitor, the weak interfacial bonding caused the coating to easily blister and peel off from the edges, rendering the protection ineffective. The performance was even worse in sodium chloride solutions, which are highly prone to penetration.

[0096] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

[0097] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A long-term anticorrosive coating for heavy corrosion duty service, characterized in that, The preparation method of the organic corrosion inhibitor comprises the following steps:

2. A long-acting anticorrosive paint for heavy corrosion conditions according to claim 1, characterized by, The preparation method of the organic corrosion inhibitor comprises the following steps: Q1: under normal temperature environment, [1,2,4] thiazole [1,5-a] pyridine-6-formaldehyde is added to a container, then a mixed solution of tetrahydrofuran and isopropyl alcohol is added, after stirring, ((6-methylpyridin-2-yl)(anilino)methyl) diphenyl phosphate and cesium carbonate are added, after normal temperature reaction, hydrochloric acid is added, after reaction, methyl tert-butyl ether is added, after stirring, separation, extraction, pH adjustment, solid precipitation, filtration, drying, the compound 1 is obtained; Q2: under normal temperature environment, the compound 1 is added to a container, then dimethyl sulfoxide is added, after stirring and dissolving, hydrobromic acid is added, after heating reaction, cooling, pH adjustment, extraction, washing, drying, filtration, drying under reduced pressure, the compound 2 is obtained; Q3: under normal temperature environment, the compound 2 is added to a container containing methanol, after stirring and mixing, ammonium acetate, phthalimidyl acetaldehyde and methyl tert-butyl ether are added in sequence, after heating reaction, cooling, pH adjustment, extraction, washing, drying, filtration, drying under reduced pressure, purification, the organic corrosion inhibitor is obtained.

3. A long-acting anticorrosive paint for heavy corrosion conditions according to claim 2, characterized by, In Q1, the amount ratio of [1,2,4] thiazole [1,5-a] pyridine-6-formaldehyde, tetrahydrofuran, isopropyl alcohol, ((6-methylpyridin-2-yl)(anilino)methyl) diphenyl phosphate, cesium carbonate and methyl tert-butyl ether is (12.21-14.72) g:(220-260) mL:(50-70) mL:(42.28-43.88) g:(14.28-16.52) g:(400-410) mL.

4. The long-acting anticorrosive paint for heavy corrosion working conditions according to claim 2, characterized in that, In Q2, the amount ratio of the compound 1, dimethyl sulfoxide and hydrobromic acid is (5.88-6.21) g:(208-224) mL:(12-15) mL.

5. The long-acting anticorrosive coating for heavy corrosion working conditions according to claim 2, characterized in that, In Q3, the amount ratio of the compound 2, methanol, ammonium acetate, phthalimidyl acetaldehyde and methyl tert-butyl ether is (21.2-23.6) mL:(180-200) mL:(18.8-19.6) mL:(31.3-35.9) mL:(140-160) mL.

6. The long-acting anticorrosive coating for heavy corrosion working conditions according to claim 1, characterized in that, The preparation method of the adhesion promoter comprises the following steps: S1: 4,4'-dipyridyl disulfide is added to a container containing dichloromethane, after stirring and dissolving, 3-mercaptopropyl triethoxysilane-containing dichloromethane is added dropwise, the dropping speed is controlled, after the addition is completed, the sealed stirring reaction is carried out, after the reaction is completed, rotary evaporation is carried out, purification is carried out, vacuum drying is carried out, and the product a is obtained; S2: the product a is added to a container containing dichloromethane, after stirring and mixing, mercapto-triglycol-azide is added, stirring reaction is carried out, after the reaction is completed, purification is carried out, and the adhesion promoter is obtained.

7. A long- lasting anticorrosive coating for heavy-duty corrosion service according to claim 6, characterized in that, In the S1, the ratio of the amount of 4,4'-dipyridyl disulfide and 3-mercaptopropyl triethoxysilane is (4.48-4.66) g:(9.88-10.21) g.

8. A long-acting anticorrosive paint for heavy corrosion conditions according to claim 6, characterized by, In the S2, the ratio of the amount of product a, dichloromethane and mercapto-triglycol-azide is (0.212-0.258) g:(10-14) mL:(0.322-0.358) g.

9. A process for the preparation of a long-term anticorrosive coating for heavy duty corrosion service as claimed in claim 1-8, wherein, The method comprises the following steps: Step one: ethylene glycol butyl ether is added into a container, then epoxy resin and fluorocarbon resin are slowly added, after stirring and mixing, dispersant, organic corrosion inhibitor and adhesion promoter are added, after stirring uniformly, a mixture is obtained; Step two: zinc phosphate, talcum powder and nano silicon dioxide are added into the mixture in sequence, after stirring uniformly, grinding is performed, then zinc powder is slowly added, stirring is performed, leveling agent and defoaming agent are added, uniform dispersion is performed, aging is performed, filtration is performed, and a long-acting anticorrosive coating for heavy corrosion working condition is obtained.

10. Use of a long-term anticorrosive coating for heavy corrosion duty, characterized in that The long-acting anticorrosive coating of any one of claims 1-8 is applied to infrastructure in the fields of petroleum, chemical industry, steel manufacturing, port facilities, wind power generation, heavy machinery equipment, military industry and aerospace.

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