Marine heavy anti-corrosion coating with long re-coating interval function and preparation method of marine heavy anti-corrosion coating

Abstract

The invention discloses a marine heavy anti-corrosion coating with a long recoating interval function and a preparation method thereof.The preparation method comprises the steps that firstly, modified polyamide, C9 petroleum resin, C5 petroleum resin, mixed xylene, silicon dioxide, zinc phosphate and modified polycaprolactone are mixed and dispersed at a high speed, and feed liquid A is obtained; mixing talcum powder, carbon black, organobentonite and 3-aminopropyltriethoxysilane, then mixing with polyether modified bisphenol A epoxy resin, cashew nut oil polyol, C9 petroleum resin, methyl isobutyl ketone and xylene, and then heating to obtain feed liquid B; and finally, uniformly mixing the feed liquid A and the feed liquid B, heating, stirring and reacting, and vacuumizing to obtain the anticorrosive coating. The anti-corrosion coating has excellent anti-corrosion performance and low-temperature crack resistance, finish paint can be directly constructed on the surface of the coating only by simply cleaning, dedusting and deoiling the surface of the coating and slightly polishing the surface of the coating, the adhesion of the finish paint is not affected, the adhesion performance is good, and the recoating interval is as long as 6-12 months.

Description

Technical Field

[0001] The present invention belongs to the field of anti-corrosion coatings, and particularly relates to a marine heavy anti-corrosion coating with a long recoating interval function and a preparation method thereof. Background Art

[0002] With the development of the global marine economy, the demand for offshore facilities such as large ships and offshore platforms is increasing continuously. These facilities are exposed to harsh marine environments for a long time and are affected by various corrosion factors such as salt spray, salt water, and ultraviolet radiation. Therefore, the requirements for anti-corrosion coatings are becoming increasingly strict. Although traditional anti-corrosion coatings can resist corrosion to a certain extent, their performance is still insufficient to meet the requirements of modern marine engineering for long-term protection, reduced maintenance cycles, and low carbon emissions.

[0003] Currently, the anti-corrosion coatings on the market generally have the problem of short recoating intervals. Usually, it is necessary to recoat every few months, which not only increases the maintenance cost but also may prevent timely maintenance due to construction window period restrictions, affecting the service life of the equipment. In addition, conventional anti-corrosion coatings have relatively strict requirements for surface treatment. Thorough grinding and cleaning are required to ensure good adhesion of subsequent coatings, which further increases the construction difficulty and cost. Summary of the Invention

[0004] The present invention is proposed to solve the problems existing in the prior art, and its purpose is to provide a marine heavy anti-corrosion coating with a long recoating interval function and a preparation method thereof.

[0005] The present invention is achieved through the following technical solutions:

[0006] A marine heavy anti-corrosion coating with a long recoating interval function, the anti-corrosion coating comprising component A and component B, and the mass ratio of component A to component B is 1:(3 - 5);

[0007] The components included in component A and the mass parts of each component are as follows:

[0008]

[0009] The components included in component B and the mass parts of each component are as follows:

[0010]

[0011]

[0012] In the above technical solution, the modified polyamide is obtained by reacting carboxyl-functionalized modified 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene with a diamine monomer.

[0013] In the above technical solution, the modified 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene is obtained by brominating 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene and then reacting it with octavinyl octasilsesquioxane.

[0014] In the above technical solution, the diamine monomer is a combination of 3,4'-diaminodiphenyl ether and 2,5-bis(aminomethyl)furan in a molar ratio of 1:0.1 to 0.3.

[0015] In the above technical solution, the modified polycaprolactone is obtained by reacting caprolactone, 2,2-bis(hydroxymethyl)propionic acid, and N-(2-aminoethyl)maleimide trifluoroacetate.

[0016] A preparation method of a marine heavy-duty anti-corrosion coating with a long recoating interval function includes the following steps:

[0017] (i) Mix modified polyamide, C9 petroleum resin, C5 petroleum resin, mixed xylene, silica, zinc phosphate, and modified polycaprolactone in proportion and disperse them at high speed for 30 min to 40 min to obtain liquid A.

[0018] (ii) Mix talcum powder, carbon black, organic bentonite, and 3-aminopropyltriethoxysilane in proportion, grind them with a sand mill for 30 to 60 min, then mix them with polyether-modified bisphenol A epoxy resin, cashew oil polyol, C9 petroleum resin, methyl isobutyl ketone, and xylene in proportion, disperse them at high speed for 30 min to 40 min, and then heat them for 1 h to 1.5 h while controlling the temperature at 75°C to 85°C to obtain liquid B.

[0019] (iii) After mixing liquid A and liquid B evenly, raise the temperature to 50°C and stir for 2.5 to 3.5 h, then raise the temperature to 130°C to 150°C and stir. After stirring evenly, evacuate to obtain a marine heavy-duty anti-corrosion coating with a long recoating interval function.

[0020] In the above technical solution, the preparation method of the modified polyamide is as follows:

[0021] 0.147 to 0.149 parts by mass of carboxyl-functionalized modified 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene, 0.257 to 0.259 parts by mass of 4,4'-dicarboxydiphenyl ether, 0.298 to 0.302 parts by mass of diamine monomer, 1 to 1.2 parts by mass of triphenyl phosphite, 2.8 to 3.2 parts by mass of N-methylpyrrolidone, 0.58 to 0.60 parts by mass of pyridine, and 0.25 to 0.35 parts by mass of calcium chloride are stirred and mixed, and then frozen, thawed, and vacuum-deoxygenated in sequence, repeated three times. Then, the reaction is carried out at 120 °C for 9.5 h to 10.5 h. After the reaction is completed, it is cooled to room temperature, and then the aforementioned reactants are slowly poured into 197 to 199 parts by mass of methanol and stirred. The polymer is washed three times with methanol and hot distilled water, filtered, and dried in vacuum to obtain the modified polyamide.

[0022] In the above technical solution, the preparation method of the carboxyl-functionalized modified 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene is as follows:

[0023] (i) 14 to 15 parts by mass of dichloromethane and modified 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene are mixed. Under the conditions of an ice bath at -10 °C to 0 °C and nitrogen protection, 4 to 6 parts by mass of tin chloride and 2 to 2.4 parts by mass of dichloromethyl methyl ether are added dropwise at a rate of 20 drops / min to 40 drops / min in sequence. After the addition is completed, it is stirred for 3.5 h to 4.5 h, then heated to room temperature and stirred for 47 h to 49 h. Subsequently, it is poured into 50 parts by mass of saturated sodium bicarbonate solution and stirred for 1 to 2 h. After stirring, it is extracted with dichloromethane, and then washed three times with deionized water, dried, and rotary evaporated to obtain aldehyde-functionalized modified 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene;

[0024] (ii) 0.5 to 0.7 parts by mass of aldehyde-functionalized modified 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene, 1.3 to 1.5 parts by mass of sodium dihydrogen phosphate, 1.55 to 1.65 parts by mass of sodium chlorite, 13 to 15 parts by mass of acetonitrile, and 17 to 19 parts by mass of deionized water are stirred and mixed. Under the conditions of an ice bath below -10 °C and nitrogen protection, 2.3 to 2.4 parts by mass of 30% hydrogen peroxide solution is added dropwise at a rate of 20 drops / min to 40 drops / min. After stirring and reacting for 4.5 h to 5.5 h, it is stirred at room temperature for 11 h to 13 h. Subsequently, 2.65 to 2.75 parts by mass of sodium sulfite is added and stirred for 35 min to 45 min, then acidified to pH 3 with 1 M hydrochloric acid solution, and then the organic solvent is removed by rotary evaporation, centrifuged, washed with water, and dried in vacuum to obtain carboxyl-functionalized modified 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene.

[0025] In the above technical solution, the preparation method of the modified 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene is as follows:

[0026] (i) Add 1-2 parts by mass of iron bromide to 114-118 parts by mass of 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene, and dropwise add 46-47 parts by mass of liquid bromine at a rate of 20 drops / min to 40 drops / min under stirring. After the addition is completed, raise the temperature to 70°C - 80°C and keep the reaction for 55 min - 65 min. Subsequently, wash successively with deionized water, a 5% sodium hydroxide solution by mass fraction, and deionized water. After standing and separating layers, take the organic phase and dry it to obtain brominated 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene;

[0027] (ii) Under nitrogen protection, mix 20-22 parts by mass of brominated 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene, 6-8 parts by mass of tetramethyltetravinylcyclotetrasiloxane, 0.7-0.8 parts by mass of tris(2-methylphenyl)phosphine, 0.3-0.4 parts by mass of palladium acetate, 10-12 parts by mass of triethylamine, and 39-41 parts by mass of tetrahydrofuran, and reflux at 84°C - 86°C for 23 h - 25 h. After cooling to room temperature, add it to 150 parts by mass of 1M hydrochloric acid solution, extract with dichloromethane 3 times, with the weight fraction of dichloromethane for each extraction being 66-68 parts by mass. Take the organic phase, wash it with water until neutral, and then dry it overnight to obtain modified 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene.

[0028] In the above technical solution, the preparation method of the modified polycaprolactone is as follows: Mix 0.35-0.45 parts by mass of 2,2-dimethylolpropionic acid, 0.6-0.8 parts by mass of N-(2-aminoethyl)maleimide trifluoroacetate with 6.7-6.9 parts by mass of caprolactone, and then add 0.024-0.026 parts by mass of the catalyst stannous octoate. Under nitrogen protection, raise the temperature to 105°C - 115°C and polymerize for 1.8 h - 2.2 h, then raise the temperature to 145°C - 155°C and react under vacuum for 3.5 h - 4.5 h, and continue to raise the temperature to 174°C - 176°C and react under vacuum for 11.5 h - 12.5 h to obtain modified polycaprolactone.

[0029] The beneficial effects of the present invention are as follows:

[0030] The present invention provides a marine heavy-duty anti-corrosion coating with a long recoating interval function and its preparation method. The prepared anti-corrosion coating has excellent anti-corrosion performance, crack resistance at low temperature. Only simple cleaning, dust removal, and oil removal treatment on the coating surface, and slight sanding are required, and then the topcoat can be directly applied thereon without affecting the adhesion of the topcoat, with good adhesion performance and a recoating interval period as long as 6 to 12 months. Detailed implementation mode

[0031] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be further described below through specific embodiments.

[0032] In the embodiments of the present invention, the epoxy equivalent of the polyether-modified bisphenol A epoxy resin is 350 - 410 (g / eq), and the viscosity is 3000 - 8000 (25°C cps)

[0033] Example 1

[0034] A preparation method of a marine heavy-duty anti-corrosion coating with a long recoating interval function, comprising the following preparation steps:

[0035] (ⅰ) Preparation method of modified 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene:

[0036] Add 1 part by mass of iron bromide to 114 parts by mass of 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene, and dropwise add 46 parts by mass of liquid bromine at a rate of 20 drops / min under stirring. After the addition is completed, raise the temperature to 70°C and keep the reaction for 55 min. Subsequently, wash successively with deionized water, a 5% sodium hydroxide solution by mass, deionized water, let it stand for stratification, take the organic phase, and dry to obtain brominated 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene;

[0037] Under nitrogen protection, mix 20 parts by mass of brominated 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene, 6 parts by mass of tetramethyltetravinylcyclotetrasiloxane, 0.7 part by mass of tris(2-methylphenyl)phosphine, 0.3 part by mass of palladium acetate, 10 parts by mass of triethylamine, and 39 parts by mass of tetrahydrofuran, reflux at 84°C for 23 h. After cooling to room temperature, add it to 150 parts by mass of 1M hydrochloric acid solution, extract with dichloromethane 3 times, with the weight of dichloromethane for each extraction being 66 parts by mass. Take the organic phase, wash it with water until neutral, and dry overnight to obtain modified 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene;

[0038] (ⅱ) Preparation of carboxyl-functionalized modified 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene

[0039] Mix 14 parts by mass of dichloromethane with 30 parts by mass of the modified 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene prepared in step (i). Under the conditions of an ice bath at -10°C and nitrogen protection, add 4 parts by mass of tin chloride and 2 parts by mass of dichloromethyl methyl ether dropwise at a rate of 20 drops / min. After stirring for 3.5 h, heat to room temperature and continue stirring for 47 h. Then pour it into 50 parts by mass of saturated sodium bicarbonate solution, stir for 1 h, extract with dichloromethane, wash three times with deionized water, dry, and rotary evaporate to obtain aldehyde-functionalized modified 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene;

[0040] Mix 0.5 part by mass of aldehyde-functionalized modified 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene, 1.3 parts by mass of sodium dihydrogen phosphate, 1.55 parts by mass of sodium chlorite, 13 parts by mass of acetonitrile, and 17 parts by mass of deionized water. Under the conditions of an ice bath below -10°C and nitrogen protection, add 2.3 parts by mass of 30% hydrogen peroxide solution dropwise at a rate of 20 drops / min. Stir and react for 4.5 h, then continue stirring at room temperature for 11 h. Subsequently, add 2.65 parts by mass of sodium sulfite and stir for 35 min. Acidify to pH 3 with 1 M hydrochloric acid solution, then rotary evaporate to remove the organic solvent, centrifuge, wash with water, and vacuum dry to obtain carboxyl-functionalized modified 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene;

[0041] (ⅲ) Preparation of modified polyamide

[0042] Mix 0.147 part by mass of carboxyl-functionalized modified 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene, 0.257 part by mass of 4,4'-dicarboxydiphenyl ether, 0.298 part by mass of diamine monomer, 1 part by mass of triphenyl phosphite, 2.8 parts by mass of N-methylpyrrolidone, 0.58 part by mass of pyridine, and 0.25 part by mass of calcium chloride. Then perform freezing, thawing, and vacuum deoxidation three times repeatedly. Then react at 120°C for 9.5 h. After cooling to room temperature, slowly pour the aforementioned reaction mixture into 197 parts by mass of methanol and stir. Wash the polymer three times repeatedly with methanol and hot distilled water, filter, and vacuum dry to obtain modified polyamide;

[0043] The diamine monomer is a combination of 3,4'-diaminodiphenyl ether and 2,5-bis(aminomethyl)furan in a molar ratio of 1:0.1;

[0044] (ⅳ) Preparation of modified polycaprolactone

[0045] 0.35 parts by mass of 2,2 - dimethylolpropionic acid, 0.6 parts by mass of N-(2 - aminoethyl) maleimide trifluoroacetate and 6.7 parts by mass of caprolactone were added with 0.024 parts by mass of stannous octoate as a catalyst. Under nitrogen protection, the temperature was raised to 105 °C for polymerization for 1.8 h, then the temperature was raised to 145 °C for vacuum reaction for 3.5 h, and the temperature was further raised to 174 °C for vacuum reaction for 11.5 h to obtain modified polycaprolactone;

[0046] (ⅴ) Weigh and mix each raw material component of component A and component B

[0047] Component A: 18.5 parts by mass of modified polyamide, 1.0 part by mass of C9 petroleum resin, 1.5 parts by mass of C5 petroleum resin, 10.5 parts by mass of mixed xylene, 17.8 parts by mass of silica, 3.2 parts by mass of zinc phosphate, 0.1 part by mass of modified polycaprolactone;

[0048] Component B: 17.9 parts by mass of polyether - modified bisphenol A epoxy resin, 11.8 parts by mass of cashew nut oil polyol, 5.3 parts by mass of C9 petroleum resin, 4.5 parts by mass of methyl isobutyl ketone, 14.2 parts by mass of xylene, 43.2 parts by mass of talc powder, 0.5 part by mass of carbon black, 0.4 part by mass of organic bentonite, 0.1 part by mass of 3 - aminopropyltriethoxysilane;

[0049] (ⅵ) Premixing of component A

[0050] Mix each raw material component of component A weighed in step (ⅴ), and disperse at high speed for 30 min to obtain liquid A;

[0051] (ⅶ) Premixing of component B

[0052] Mix 43.2 parts by mass of talc powder, 0.5 part by mass of carbon black, 0.4 part by mass of organic bentonite, 0.1 part by mass of 3 - aminopropyltriethoxysilane, grind with a sand mill for 30 min, and then mix with 17.9 parts by mass of polyether - modified bisphenol A epoxy resin, 11.8 parts by mass of cashew nut oil polyol, 5.3 parts by mass of C9 petroleum resin, 4.5 parts by mass of methyl isobutyl ketone, 14.2 parts by mass of xylene and disperse at high speed for 30 min, then heat and control the temperature at 75 °C to obtain liquid B;

[0053] (ⅷ) After mixing liquid A and liquid B evenly according to the mass ratio of 1:3, raise the temperature to 50 °C and stir - react for 2.5 h, then stir evenly at 130 °C and evacuate to obtain a marine heavy - duty anticorrosive coating with a long recoat interval function.

[0054] Example 2

[0055] A preparation method of a marine heavy-duty anti-corrosion coating with a long recoating interval function, comprising the following preparation steps:

[0056] (ⅰ) Preparation of modified 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene

[0057] Add 2.5 parts by mass of iron bromide to 116 parts by mass of 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene, and dropwise add 48 parts by mass of liquid bromine at 30 drops / min under stirring conditions. After the addition is complete, raise the temperature to 75 °C and keep the reaction for 60 min. Then, wash successively with deionized water, a 5% sodium hydroxide solution by mass fraction, and deionized water. After standing and separating layers, take the organic phase and dry it to obtain brominated 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene;

[0058] Under nitrogen protection, mix 21 parts by mass of brominated 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene, 7 parts by mass of tetramethyltetravinylcyclotetrasiloxane, 0.75 part by mass of tris(2-methylphenyl)phosphine, 0.35 part by mass of palladium acetate, 11 parts by mass of triethylamine, and 40 parts by mass of tetrahydrofuran, and reflux at 85 °C for 24 h. After cooling to room temperature, add it to 150 parts by mass of 1 M hydrochloric acid solution, and extract with dichloromethane 3 times, with the weight fraction of dichloromethane for each extraction being 67 parts by mass. Take the organic phase, wash it with water until neutral, and dry it overnight to obtain modified 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene.

[0059] (ⅱ) Preparation of carboxyl-functionalized modified 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene

[0060] Mix 14.5 parts by mass of dichloromethane with 28.3 parts by mass of modified 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene. Under the conditions of a -10 °C ice bath and nitrogen protection, dropwise add 5 parts by mass of tin chloride and 2.2 parts by mass of dichloromethyl methyl ether at 30 drops / min. After stirring for 4 h, heat to room temperature and continue stirring for 48 h. Then, pour it into 50 parts by mass of saturated sodium bicarbonate solution, stir for 2.5 h, extract with dichloromethane, and wash with deionized water three times. Dry and rotary evaporate to obtain aldehyde-functionalized modified 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene;

[0061] 0.6 parts by mass of aldehyde-functionalized modified 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene, 1.4 parts by mass of sodium dihydrogen phosphate, 1.6 parts by mass of sodium chlorite, 14 parts by mass of acetonitrile, and 18 parts by mass of deionized water were stirred and mixed. Under an ice bath below -10°C and nitrogen protection, 2.35 parts by mass of a 30% hydrogen peroxide solution was added dropwise at 30 drops / min. After stirring and reacting for 5 h, stirring was continued at room temperature for 12 h. Subsequently, 2.7 parts by mass of sodium sulfite was added and stirred for 40 min, and then acidified to pH 3 with 1 M hydrochloric acid solution. Then, the organic solvent was removed by rotary evaporation, centrifuged, washed with water, and dried under vacuum to obtain carboxyl-functionalized modified 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene.

[0062] (ⅲ) Preparation of modified polyamide

[0063] 0.148 parts by mass of carboxyl-functionalized modified 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene, 0.258 parts by mass of 4,4'-dicarboxydiphenyl ether, 0.3 parts by mass of diamine monomer, 1.1 parts by mass of triphenyl phosphite, 3 parts by mass of N-methylpyrrolidone, 0.59 parts by mass of pyridine, and 0.3 parts by mass of calcium chloride were stirred and mixed. Then, it was frozen, thawed, and evacuated to remove oxygen, and this was repeated three times. Then, it was reacted at 120°C for 10 h. After cooling to room temperature, it was slowly poured into 198 parts by mass of methanol and stirred. The polymer was washed three times with methanol and hot distilled water, filtered, and dried under vacuum to obtain modified polyamide. The diamine monomer was a combination of 3,4'-diaminodiphenyl ether and 2,5-bis(aminomethyl)furan in a molar ratio of 1:0.2.

[0064] (ⅳ) Preparation of modified polycaprolactone

[0065] 0.4 parts by mass of 2,2-bis(hydroxymethyl)propionic acid, 0.7 parts by mass of N-(2-aminoethyl)maleimide trifluoroacetate, and 6.8 parts by mass of caprolactone were added with 0.025 parts by mass of the catalyst stannous octoate. Under nitrogen protection, the temperature was raised to 110°C for polymerization for 2 h, then the temperature was raised to 150°C for vacuum reaction for 4 h, and the temperature was further raised to 175°C for vacuum reaction for 12 h to obtain modified polycaprolactone;

[0066] (ⅴ) Weighing and proportioning each raw material component of component A and component B

[0067] Component A: 19 parts by mass of modified polyamide, 1.3 parts by mass of C9 petroleum resin, 2 parts by mass of C5 petroleum resin, 11.5 parts by mass of mixed xylene, 18 parts by mass of silica, 3.4 parts by mass of zinc phosphate, 0.2 parts by mass of modified polycaprolactone;

[0068] Component B: 18.2 parts by mass of polyether-modified bisphenol A epoxy resin, 12.3 parts by mass of cashew nut oil polyol, 5.6 parts by mass of C9 petroleum resin, 4.8 parts by mass of methyl isobutyl ketone, 14.6 parts by mass of xylene, 43.6 parts by mass of talcum powder, 0.8 parts by mass of carbon black, 0.6 parts by mass of organic bentonite, 0.2 parts by mass of 3-aminopropyltriethoxysilane;

[0069] (ⅵ) Premixing of Component A

[0070] Mix the raw material components of Component A weighed in step (ⅴ), disperse them at high speed for 35 min to obtain liquid A;

[0071] (ⅶ) Premixing of Component B

[0072] Mix 43.6 parts by mass of talcum powder, 0.8 parts by mass of carbon black, 0.6 parts by mass of organic bentonite, and 0.2 parts by mass of 3-aminopropyltriethoxysilane, grind them with a sand mill for 45 min, and then mix them with 18.2 parts by mass of polyether-modified bisphenol A epoxy resin, 12.3 parts by mass of cashew nut oil polyol, 5.6 parts by mass of C9 petroleum resin, 4.8 parts by mass of methyl isobutyl ketone, and 14.6 parts by mass of xylene, disperse them at high speed for 35 min, and then heat and control the temperature at 80 °C to obtain liquid B;

[0073] (ⅷ) After mixing liquid A and liquid B evenly according to the mass ratio of 1:4, raise the temperature to 50 °C, stir and react for 3 h, stir evenly at 140 °C, and then evacuate to obtain a marine heavy-duty anticorrosive coating with a long recoating interval function.

[0074] Example 3

[0075] A preparation method of a marine heavy-duty anticorrosive coating with a long recoating interval function, comprising the following preparation steps:

[0076] (ⅰ) Preparation of modified 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene

[0077] Add 2 parts by mass of iron bromide to 118 parts by mass of 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene, dropwise add 47 parts by mass of liquid bromine at a rate of 40 drops / min under stirring conditions, after the addition is complete, raise the temperature to 80 °C and keep it warm for reaction for 65 min, then wash successively with deionized water, 5% sodium hydroxide solution by mass, deionized water, let it stand for layering, take the organic phase, and dry to obtain brominated 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene;

[0078] Under nitrogen protection, 22 parts by mass of brominated 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene, 8 parts by mass of tetramethyltetravinylcyclotetrasiloxane, 0.8 parts by mass of tris(2-methylphenyl)phosphine, 0.4 parts by mass of palladium acetate, 12 parts by mass of triethylamine, and 41 parts by mass of tetrahydrofuran were mixed, refluxed at 86 °C for 25 h. After cooling to room temperature, it was added to 150 parts by mass of 1 M hydrochloric acid solution, and extracted with dichloromethane 3 times, with the weight of dichloromethane for each extraction being 68 parts by mass. The organic phase was washed with water until neutral and then dried overnight to obtain modified 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene;

[0079] (ⅱ) Preparation of carboxyl-functionalized modified 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene

[0080] 15 parts by mass of dichloromethane was mixed with 26.6 parts by mass of modified 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene. Under the conditions of an ice bath at -10 °C and nitrogen protection, 6 parts by mass of tin chloride and 2.4 parts by mass of dichloromethyl methyl ether were added dropwise at a rate of 40 drops / min. After stirring for 4.5 h, it was heated to room temperature and stirred for another 49 h. Then it was poured into 50 parts by mass of saturated sodium bicarbonate solution, stirred for 2 h, extracted with dichloromethane, washed three times with deionized water, dried, and rotary evaporated to obtain aldehyde-functionalized modified 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene;

[0081] 0.7 parts by mass of aldehyde-functionalized modified 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene, 1.5 parts by mass of sodium dihydrogen phosphate, 1.65 parts by mass of sodium chlorite, 15 parts by mass of acetonitrile, and 19 parts by mass of deionized water were stirred and mixed. Under the conditions of an ice bath below -10 °C and nitrogen protection, 2.4 parts by mass of 30% hydrogen peroxide solution was added dropwise at a rate of 40 drops / min. After stirring and reacting for 5.5 h, it was stirred at room temperature for another 13 h. Then 2.75 parts by mass of sodium sulfite was added and stirred for 45 min. It was acidified to pH 3 with 1 M hydrochloric acid solution, then the organic solvent was removed by rotary evaporation, centrifuged, washed with water, and vacuum dried to obtain carboxyl-functionalized modified 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene.

[0082] (ⅲ) Preparation of modified polyamide

[0083] Mix 0.149 parts by mass of carboxyl-functionalized 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene, 0.259 parts by mass of 4,4'-dicarboxydiphenyl ether, 0.302 parts by mass of diamine monomer, 1.2 parts by mass of triphenyl phosphite, 3.2 parts by mass of N-methylpyrrolidone, 0.60 parts by mass of pyridine, and 0.35 parts by mass of calcium chloride. Then, perform freezing, thawing, and vacuum deoxidation three times repeatedly. After that, react at 120 °C for 10.5 h. After cooling to room temperature, slowly pour it into 199 parts by mass of methanol and stir. Wash the polymer with methanol and hot distilled water three times repeatedly, filter, and dry under vacuum to obtain the modified polyamide. The diamine monomer is a combination of 3,4'-diaminodiphenyl ether and 2,5-bis(aminomethyl)furan in a molar ratio of 1:0.3;

[0084] (ⅳ) Preparation of modified polycaprolactone

[0085] Add 0.45 parts by mass of 2,2-bis(hydroxymethyl)propionic acid, 0.8 parts by mass of N-(2-aminoethyl)maleimide trifluoroacetate, and 6.9 parts by mass of caprolactone, and add 0.026 parts by mass of the catalyst stannous octoate. Under nitrogen protection, heat to 115 °C and polymerize for 2.2 h, then heat to 155 °C and react under vacuum for 4.5 h, and continue to heat to 176 °C and react under vacuum for 12.5 h to obtain the modified polycaprolactone;

[0086] (ⅴ) Weigh and mix the raw material components of Component A and Component B respectively:

[0087] Component A: 21.5 parts by mass of modified polyamide, 1.5 parts by mass of C9 petroleum resin, 2.5 parts by mass of C5 petroleum resin, 12.5 parts by mass of mixed xylene, 18.4 parts by mass of silica, 3.6 parts by mass of zinc phosphate, 0.3 parts by mass of modified polycaprolactone;

[0088] Component B: 18.5 parts by mass of polyether-modified bisphenol A epoxy resin, 12.8 parts by mass of cashew nut oil polyol, 5.9 parts by mass of C9 petroleum resin, 5.1 parts by mass of methyl isobutyl ketone, 15.0 parts by mass of xylene, 43.8 parts by mass of talc powder, 1.0 parts by mass of carbon black, 0.9 parts by mass of organic bentonite, 0.3 parts by mass of 3-aminopropyltriethoxysilane;

[0089] (ⅵ) Premixing of Component A

[0090] Mix the raw material components of Component A weighed in step (ⅴ), and disperse at high speed for 40 min to obtain liquid A;

[0091] (ⅶ) Premixing of Component B

[0092] Mix 43.8 parts by mass of talcum powder, 1.0 part by mass of carbon black, 0.9 part by mass of organic bentonite, and 0.3 part by mass of 3-aminopropyltriethoxysilane, grind them with a sand mill for 60 min, and then mix them with 18.5 parts by mass of polyether-modified bisphenol A epoxy resin, 12.8 parts by mass of cashew nut oil polyol, 5.9 parts by mass of C9 petroleum resin, 5.1 parts by mass of methyl isobutyl ketone, and 15.0 parts by mass of xylene, disperse them at high speed for 40 min, and then heat and control the temperature at 85 °C to obtain liquid B;

[0093] (ⅷ) After mixing liquid A and liquid B evenly according to a mass ratio of 1:5, raise the temperature to 50 °C, stir and react for 3.5 h, stir evenly at 150 °C, and then evacuate to obtain a marine heavy-duty anti-corrosion coating with a long recoating interval function.

[0094] Comparative Example 1

[0095] The difference between Comparative Example 1 and Example 2 is only that the modified polyamide is only obtained by reacting carboxyl-functionalized 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene with a diamine monomer. The specific steps are as follows:

[0096] (ⅰ) Preparation of carboxyl-functionalized 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene

[0097] Mix 14.5 parts by mass of dichloromethane with 1 part by mass of 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene. Under the conditions of -10 °C ice bath and nitrogen protection, dropwise add 5 parts by mass of tin chloride and 2.2 parts by mass of dichloromethyl methyl ether at a rate of 30 drops / min, stir for 4 h, heat to room temperature and continue to stir for 48 h, then pour it into 50 parts by mass of saturated sodium bicarbonate solution, stir for 2.5 h, extract with dichloromethane, wash three times with deionized water, dry, and rotary evaporate to obtain aldehyde-functionalized 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene;

[0098] Mix 0.6 part by mass of aldehyde-functionalized modified 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene, 1.4 parts by mass of sodium dihydrogen phosphate, 1.6 parts by mass of sodium chlorite, 14 parts by mass of acetonitrile, and 18 parts by mass of deionized water, stir and mix. Under the conditions of ice bath below -10 °C and nitrogen protection, dropwise add 2.35 parts by mass of 30% hydrogen peroxide solution at a rate of 30 drops / min, stir and react for 5 h, continue to stir at room temperature for 12 h, then add 2.7 parts by mass of sodium sulfite and stir for 40 min, acidify to pH 3 with 1M hydrochloric acid solution, then rotary evaporate to remove the organic solvent, centrifuge, wash with water, and vacuum dry to obtain carboxyl-functionalized 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene;

[0099] (ⅱ) Preparation of modified polyamide

[0100] Mix 0.148 parts by mass of carboxyl-functionalized 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene, 0.258 parts by mass of 4,4'-dicarboxydiphenyl ether, 0.3 parts by mass of diamine monomer, 1.1 parts by mass of triphenyl phosphite, 3 parts by mass of N-methylpyrrolidone, 0.59 parts by mass of pyridine and 0.3 parts by mass of calcium chloride, then perform freezing, thawing, and vacuum deoxidation, repeating three times. Then react at 120 °C for 10 h. After cooling to room temperature, slowly pour it into 198 parts by mass of methanol and stir. Wash the polymer with methanol and hot distilled water three times repeatedly, filter, and dry in vacuum to obtain the modified polyamide. The diamine monomer is a combination of 3,4'-diaminodiphenyl ether and 2,5-bis(aminomethyl)furan in a molar ratio of 1:0.2;

[0101] (ⅲ) Preparation of modified polycaprolactone

[0102] Add 0.4 parts by mass of 2,2-bis(hydroxymethyl)propionic acid, 0.7 parts by mass of N-(2-aminoethyl)maleimide trifluoroacetate and 6.8 parts by mass of caprolactone, add 0.025 parts by mass of the catalyst stannous octanoate, heat to 110 °C under nitrogen protection and polymerize for 2 h, then heat to 150 °C and react under vacuum for 4 h, continue to heat to 175 °C and react under vacuum for 12 h to obtain the modified polycaprolactone;

[0103] (ⅳ) Weigh and proportion the raw material components of component A and component B:

[0104] Component A: 19 parts by mass of modified polyamide, 1.3 parts by mass of C9 petroleum resin, 2 parts by mass of C5 petroleum resin, 11.5 parts by mass of mixed xylene, 18 parts by mass of silica, 3.4 parts by mass of zinc phosphate, 0.2 parts by mass of modified polycaprolactone;

[0105] Component B: 18.2 parts by mass of polyether-modified bisphenol A epoxy resin, 12.3 parts by mass of cashew nut oil polyol, 5.6 parts by mass of C9 petroleum resin, 4.8 parts by mass of methyl isobutyl ketone, 14.6 parts by mass of xylene, 43.6 parts by mass of talc powder, 0.8 parts by mass of carbon black, 0.6 parts by mass of organic bentonite, 0.2 parts by mass of 3-aminopropyltriethoxysilane;

[0106] (ν) Premixing of component A

[0107] Mix the raw material components of component A weighed in step (ⅳ), disperse at high speed for 35 min to obtain liquid material A;

[0108] (ⅵ) Premixing of component B

[0109] Mix 43.6 parts by mass of talcum powder, 0.8 parts by mass of carbon black, 0.6 parts by mass of organic bentonite, and 0.2 parts by mass of 3-aminopropyltriethoxysilane, grind them with a sand mill for 45 min, and then mix them with 18.2 parts by mass of polyether-modified bisphenol A epoxy resin, 12.3 parts by mass of cashew oil polyol, 5.6 parts by mass of C9 petroleum resin, 4.8 parts by mass of methyl isobutyl ketone, and 14.6 parts by mass of xylene, disperse them at high speed for 35 min, and then heat and control the temperature at 80 °C to obtain liquid B;

[0110] (ⅶ) After mixing liquid A and liquid B evenly according to the mass ratio of 1:4, raise the temperature to 50 °C, stir and react for 3 h, stir evenly at 140 °C, and then evacuate to obtain a marine anti-corrosion coating.

[0111] Comparative Example 2

[0112] The difference between Comparative Example 2 and Example 2 is only that the modified polyamide is only obtained by reacting 4,4'-dicarboxydiphenyl ether with a diamine monomer, and the rest of the steps are the same as those in Example 2;

[0113] The specific steps of the preparation method of the modified polyamide are as follows:

[0114] Mix 0.406 parts by mass of 4,4'-dicarboxydiphenyl ether, 0.3 parts by mass of diamine, 1.1 parts by mass of triphenyl phosphite, 3 parts by mass of N-methylpyrrolidone, 0.59 parts by mass of pyridine, and 0.3 parts by mass of calcium chloride, then carry out freezing, thawing, and vacuum deoxidation three times repeatedly, then react at 120 °C for 10 h, cool to room temperature, slowly pour it into 198 parts by mass of methanol and stir, wash the polymer with methanol and hot distilled water three times repeatedly, filter, and dry in vacuum to obtain the modified polyamide. The diamine monomer is a combination of 3,4'-diaminodiphenyl ether and 2,5-bis(aminomethyl)furan in a molar ratio of 1:0.2.

[0115] Comparative Example 3

[0116] The difference between Comparative Example 3 and Example 2 is only that the diamine monomer only uses 3,4'-diaminodiphenyl ether, and the rest of the steps are the same as those in Example 2;

[0117] The specific steps of the preparation method of the modified polyamide are as follows:

[0118] 0.148 parts by mass of carboxyl-functionalized 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene, 0.258 parts by mass of 4,4'-dicarboxydiphenyl ether, 0.3 parts by mass of 3,4'-diaminodiphenyl ether, 1.1 parts by mass of triphenyl phosphite, 3 parts by mass of N-methylpyrrolidone, 0.59 parts by mass of pyridine and 0.3 parts by mass of calcium chloride were stirred and mixed. Then, it was frozen, thawed, and evacuated to remove oxygen, and this process was repeated three times. Then, the reaction was carried out at 120 °C for 10 h. After cooling to room temperature, it was slowly poured into 198 parts by mass of methanol and stirred. The polymer was washed three times with methanol and hot distilled water, filtered, and dried under vacuum to obtain the modified polyamide. The diamine monomer was a combination of 3,4'-diaminodiphenyl ether and 2,5-bis(aminomethyl)furan in a molar ratio of 1:0.2.

[0119] Comparative Example 4

[0120] The difference between Comparative Example 4 and Example 2 was only that: the modified polycaprolactone was only obtained by the reaction of caprolactone and 2,2-bis(hydroxymethyl)propionic acid, and the rest of the steps were the same as those in Example 2;

[0121] The specific steps for the preparation of the modified polycaprolactone were as follows:

[0122] 1.1 parts by mass of 2,2-bis(hydroxymethyl)propionic acid and 6.8 parts by mass of caprolactone were added with 0.025 parts by mass of the catalyst stannous octoate. Under nitrogen protection, the temperature was raised to 110 °C for polymerization for 2 h, then the temperature was raised to 150 °C for vacuum reaction for 4 h, and the temperature was further raised to 175 °C for vacuum reaction for 12 h to obtain the modified polycaprolactone.

[0123] Comparative Example 5

[0124] The difference between Comparative Example 5 and Example 2 was only that: the modified polycaprolactone was only obtained by the reaction of caprolactone and N-(2-aminoethyl)maleimide trifluoroacetate, and the rest of the steps were the same as those in Example 2;

[0125] The specific steps for the preparation of the modified polycaprolactone were as follows:

[0126] 1.1 parts by mass of N-(2-aminoethyl)maleimide trifluoroacetate and 6.8 parts by mass of caprolactone were added with 0.025 parts by mass of the catalyst stannous octoate. Under nitrogen protection, the temperature was raised to 110 °C for polymerization for 2 h, then the temperature was raised to 150 °C for vacuum reaction for 4 h, and the temperature was further raised to 175 °C for vacuum reaction for 12 h to obtain the modified polycaprolactone.

[0127] The coatings prepared in the examples and comparative examples were evaluated for their effects:

[0128] Coat the Q235 steel plate with the marine heavy-duty anti-corrosion coatings prepared in the examples and comparative examples having the function of long recoating intervals, pre-cure at 60 °C for 2 h, control the coating thickness at 90 - 110 μm, and then cure at 80 °C for 12 h to obtain the coatings of the marine heavy-duty anti-corrosion coatings having the function of long recoating intervals.

[0129] Appearance performance: Observe whether there is peeling or cracking on the coatings of the marine heavy-duty anti-corrosion coatings prepared in the examples and comparative examples having the function of long recoating intervals.

[0130] Abrasion resistance: Take the coatings of the marine heavy-duty anti-corrosion coatings prepared in the examples and comparative examples having the function of long recoating intervals and test the hardness according to GB / T6739.

[0131] Impact resistance: Take the coatings of the marine heavy-duty anti-corrosion coatings prepared in the examples and comparative examples having the function of long recoating intervals and test the impact resistance according to GB / T1732. Let a 1 Kg weight freely fall onto the plate in ascending order until there are phenomena such as cracks or peeling on the coating, and record the height.

[0132] Salt spray resistance: Take the coatings of the marine heavy-duty anti-corrosion coatings prepared in the examples and comparative examples having the function of long recoating intervals and test the salt spray resistance according to GB / T10125. Record the time when there are a small number of bubbles on the coating surface and slight rust appears at the bottom of the coating.

[0133] Brine resistance: Take the coatings of the marine heavy-duty anti-corrosion coatings prepared in the examples and comparative examples having the function of long recoating intervals and test the brine resistance according to GB / T1727. Record the time when there are a small number of bubbles on the coating surface and slight rust appears at the bottom of the coating.

[0134] Self-healing performance: Take the coatings of the marine heavy-duty anti-corrosion coatings prepared in the examples and comparative examples having the function of long recoating intervals, make scratches, heat at 150 °C for 4 h, and then cure at 60 °C for 24 h, and observe whether the coating surface heals.

[0135] Adhesion: Take the coatings of the marine heavy-duty anti-corrosion coatings prepared in the examples and comparative examples having the function of long recoating intervals and test the adhesion according to GB / T5210.

[0136] The following Table 1 shows the performance test results of the coatings of the marine heavy-duty anti-corrosion coatings prepared in the examples and comparative examples having the function of long recoating intervals:

[0137] Table 1

[0138]

[0139] Comparing the performance data of the marine heavy-duty anti-corrosion coatings with long recoating intervals prepared in Examples and Comparative Examples in Table 1, the marine heavy-duty anti-corrosion coatings prepared in Examples 1 to 3 have better anti-corrosion performance, stronger adhesion, better impact resistance and wear resistance, better appearance performance, and self-healing performance.

[0140] Comparing Comparative Example 1 with Example 2, the modified polyamide in Comparative Example 1 is only obtained by reacting carboxyl-functionalized 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene with a diamine monomer.

[0141] While the modified polyamide in Example 2 is only obtained by reacting carboxyl-functionalized modified 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene with a diamine monomer; the modified 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene in Example 2 is obtained by brominating 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene and then reacting it with octavinyl octasilsequioxane; since the polyamide modified by 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene increases the degree of branching of the epoxy resin molecular chain after being introduced into the epoxy resin, reduces the intermolecular force, and reduces the impact resistance and wear resistance.

[0142] Comparing Comparative Example 2 with Example 2, the modified polyamide in Comparative Example 2 is only obtained by reacting 4,4'-dicarboxydiphenyl ether with a diamine monomer to obtain 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene. During the curing process of the epoxy resin, thermal expansion causes partial cracking of the coating, resulting in poor corrosion resistance and poor impact resistance.

[0143] Comparing Comparative Example 3 with Example 2, only 3,4'-diaminodiphenyl ether is used as the diamine monomer in Comparative Example 3, and it cannot undergo a Diels-Alder reaction with the modified polycaprolactone, resulting in poor self-healing performance.

[0144] Comparing Comparative Example 4 with Example 2, the modified polycaprolactone in Comparative Example 4 is only obtained by reacting caprolactone with 2,2-bis(hydroxymethyl)propionic acid. The thermal stability of the polycaprolactone is weak, the overall impact resistance is lower than that of Example, the wear resistance is poor, and it cannot undergo a Diels-Alder reaction with the modified polyamide, resulting in poor self-healing performance.

[0145] Comparing Comparative Example 5 with Example 2, the modified polycaprolactone in Comparative Example 5 is only obtained by reacting caprolactone with N-(2-aminoethyl)maleimide trifluoroacetate. It cannot form a hyperbranched polycaprolactone structure, and the toughening effect is worse than that of Example, and the overall impact resistance is lower than that of Example.

[0146] The principle of the present invention:

[0147] In the anticorrosive coating of the present invention, the modified polyamide is obtained by reacting carboxyl-functionalized 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene with a diamine monomer. The carboxyl group on the carboxyl-functionalized 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene reacts with the amino group on the diamine monomer to form polyamide. By introducing 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene into the polyamide, and utilizing the conformational transformation of 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene from the twisted form to the chair form under near-infrared radiation or heating, the polyamide is endued with the property of thermal shrinkage, which can effectively improve the thermal expansion during the thermal curing process of the epoxy resin base material in the coating, prevent the adhesion of the coating prepared from the marine heavy-duty anticorrosive coating from decreasing, or prevent the coating from cracking and separating from the substrate interface.

[0148] The raw material for preparing the modified polyamide in the anticorrosive coating of the present invention, the modified 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene, is obtained by reacting brominated 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene with octavinyl octasilsequioxane. Through the graft reaction of the bromine on the benzene ring after bromination of 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene with the vinyl group on octavinyl octasilsequioxane, octavinyl octasilsequioxane is introduced into the polyamide to form a polyamide with a hyperbranched structure. And due to the relatively large rigidity of octavinyl octasilsequioxane, it can avoid the problems that the introduction of 5,6,11,12-tetrahydrodibenzo[a,e]cyclooctene-modified polyamide into epoxy resin increases the degree of branching of the epoxy resin molecular chain, reduces the intermolecular force, decreases the tensile strength, and reduces the impact strength, thus enhancing the impact resistance and wear resistance of the coating prepared from the marine heavy-duty anticorrosive coating.

[0149] The modified polycaprolactone in the anticorrosive coating of the present invention is obtained by reacting caprolactone, 2,2-bis(hydroxymethyl)propionic acid, and N-(2-aminoethyl)maleimide trifluoroacetate. By introducing 2,2-bis(hydroxymethyl)propionic acid into the modified polycaprolactone to form a polycaprolactone with a hyperbranched structure, the toughness of the coating prepared from the marine heavy-duty anticorrosive coating can be effectively enhanced. And the introduction of N-(2-aminoethyl)maleimide trifluoroacetate helps to increase the thermal decomposition temperature of the modified polycaprolactone, enabling it to maintain good physical and chemical properties in a high-temperature environment.

[0150] After the component A and component B of the present invention are mixed, the molecular chains of polyether-modified bisphenol A epoxy resin in component B, modified polyamide and modified polycaprolactone in component A interpenetrate and crosslink with each other. The furan on the modified polyamide and the maleimide on the modified polycaprolactone undergo a Diels-Alder reaction for crosslinking, endowing the coating prepared from the marine heavy-duty anti-corrosion coating with good self-healing performance. Moreover, the crosslinking density of the coating prepared from the marine heavy-duty anti-corrosion coating is further improved by the Michael addition ene-amine addition reaction crosslinking of the unsaturated olefin bond in component B and the unreacted amine in component A, and it synergistically acts with talcum powder, carbon black, organic bentonite, 3-aminopropyltriethoxysilane, and nano-silica in component A and component B, enhancing the adhesion and anti-corrosion performance of the marine heavy-duty anti-corrosion coating. The salt spray and salt water resistance can reach up to 4200 h, and it can be applied to harsh corrosion environments such as large ships and offshore platforms.

[0151] The applicant declares that the above description is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by any person skilled in the art within the technical scope disclosed by the present invention fall within the protection scope and the disclosure scope of the present invention.

Claims

1. A marine heavy-duty anticorrosive coating with a long overcoating interval, characterized in that: The anticorrosive coating comprises component A and component B, wherein the mass ratio of component A to component B is 1:(3-5); The components included in component A and the mass parts of each component are as follows: The components included in component B and the mass parts of each component are as follows:

2. The marine heavy-duty anticorrosive coating with a long overcoating interval function according to claim 1, characterized in that: The modified polyamide is obtained by reacting carboxyl-functionalized modified 5,6,11,12-tetrahydrodibenzo[a,e]annulene with a diamine monomer.

3. The marine heavy-duty anticorrosive coating with a long overcoating interval function according to claim 2, characterized in that: The modified 5,6,11,12-tetrahydrodibenzo[a,e]annulene is obtained by reacting 5,6,11,12-tetrahydrodibenzo[a,e]annulene with octavinyloctasilsesquioxane after bromination.

4. The marine heavy-duty anticorrosive coating with a long overcoating interval function according to claim 2, characterized in that: The diamine monomer is obtained by combining 3,4'-diaminodiphenyl ether and 2,5-di(aminomethyl)furan in a molar ratio of 1:0.1 to 0.

3.

5. The marine heavy-duty anticorrosive coating with a long overcoating interval function according to claim 1, characterized in that: The modified polycaprolactone is composed of caprolactone, 2,2-bis(hydroxymethyl) propionic acid, Obtained by reaction of N-(2-aminoethyl)maleimide trifluoroacetate.

6. A method for preparing a marine heavy-duty anticorrosive coating with a long overcoating interval function according to any one of claims 1 to 5, characterized in that: The following steps are involved: (i) mixing modified polyamide, C9 petroleum resin, C5 petroleum resin, mixed xylene, silicon dioxide, zinc phosphate and modified polycaprolactone in proportion, dispersing at high speed, to obtain a feed liquid A; (ii) talcum powder, carbon black, organic bentonite, and 3-aminopropyl triethoxysilane are mixed in proportion, ground with a sand mill, and then mixed with polyether-modified bisphenol A epoxy resin, cashew nut oil polyol, C9 petroleum resin, methyl isobutyl ketone and xylene in proportion, dispersed at high speed, and then heated for 1 h to 1.5 h while controlling the temperature at 75° C. to 85° C. to obtain liquid B; (iii) After mixing liquid A and liquid B in proportion, the mixture is heated to 50°C and stirred for 2.5h to 3.5h, and then heated to 130°C to 150°C and stirred. After stirring evenly, the mixture is evacuated to obtain a marine heavy-duty anti-corrosion coating with a long overcoating interval.

7. The method for preparing a marine heavy-duty anticorrosive coating with a long overcoating interval according to claim 6, characterized in that: The preparation method of the modified polyamide is: 0.147-0.149 parts by weight of carboxyl functionalized modified 5,6,11,12-tetrahydrodibenzo[a,e]annulene, 0.257-0.259 parts by weight of 4,4'-dicarboxyl diphenyl ether, 0.298-0.302 parts by weight of diamine monomer, 1-1.2 parts by weight of triphenyl phosphite, 2.8-3.2 parts by weight of N-methylpyrrolidone, 0.58-0.60 parts by weight of pyridine and 0.25-0.35 parts by weight of calcium chloride are stirred and mixed, and then frozen, thawed and vacuum deoxidized three times in sequence, and then reacted at 120° C. for 9.5 h to 10.5 h. After the reaction is completed, the mixture is cooled to room temperature, and then the reactants are slowly poured into 197-199 parts by weight of methanol and stirred. The polymer is repeatedly washed three times with methanol and hot distilled water, filtered, and vacuum dried to obtain a modified polyamide.

8. The method for preparing a marine heavy-duty anticorrosive coating with a long overcoating interval according to claim 7, characterized in that: The preparation method of the carboxyl functionalized modified 5,6,11,12-tetrahydrodibenzo[a,e]annulene is as follows: (i) 14 to 15 parts by weight of dichloromethane and 26 to 30 parts by weight of modified 5,6,11,12-tetrahydrodibenzo[a,e]annulene are mixed, and 4 to 6 parts by weight of tin chloride and 2 to 2.4 parts by weight of dichloromethyl methyl ether are added dropwise at a rate of 20 drops / min to 40 drops / min in an ice bath at -10°C to 0°C and under nitrogen protection. After the addition is completed, the mixture is stirred for 3.5 to 4.5 hours, and then heated to room temperature and stirred for 47 to 49 hours. Subsequently, 50 parts by weight of saturated sodium bicarbonate solution is added and stirred for 1 to 2 hours. After stirring, the mixture is extracted with dichloromethane, and then washed three times with deionized water, dried, and rotary evaporated to obtain modified 5,6,11,12-tetrahydrodibenzo[a,e]annulene functionalized with aldehyde groups; (ii) 0.5-0.7 parts by weight of aldehyde-functionalized modified 5,6,11,12-tetrahydrodibenzo[a,e]annulene, 1.3-1.5 parts by weight of sodium dihydrogen phosphate, 1.55-1.65 parts by weight of sodium chlorite, 13-15 parts by weight of acetonitrile and 17-19 parts by weight of deionized water were stirred and mixed, and 2.3-2.4 parts by weight of acetonitrile were added dropwise at a rate of 20 drops / min to 40 drops / min in an ice bath below -10°C and under nitrogen protection. 4 parts by mass of a 30% hydrogen peroxide solution are stirred for reaction for 4.5 to 5.5 hours, and then stirred for 11 to 13 hours at room temperature. Subsequently, 2.65 to 2.75 parts by mass of sodium sulfite are added and stirred for 35 to 45 minutes, and then acidified to pH 3 with a 1M hydrochloric acid solution. The organic solvent is then removed by rotary evaporation, centrifuged, washed with water, and vacuum dried to obtain carboxyl functionalized 5,6,11,12-tetrahydrodibenzo[a,e]annulene.

9. The method for preparing a marine heavy-duty anticorrosive coating with a long overcoating interval according to claim 8, characterized in that: The preparation method of the modified 5,6,11,12-tetrahydrodibenzo[a,e]annulene is: (i) adding 1 to 2 parts by weight of ferric bromide to 114 to 118 parts by weight of 5,6,11,12-tetrahydrodibenzo[a,e]annulene, and dropping 46 to 47 parts by weight of liquid bromine at a rate of 20 drops / min to 40 drops / min under stirring conditions, heating to 70° C. to 80° C. after completion of the dropping, and keeping the temperature to react for 55 to 65 minutes, followed by washing with deionized water, 5% sodium hydroxide solution, and deionized water in sequence, allowing to stand for stratification, collecting the organic phase, and drying to obtain brominated 5,6,11,12-tetrahydrodibenzo[a,e]annulene; (ii) Under nitrogen protection, 20 to 22 parts by weight of the brominated 5,6,11,12-tetrahydrodibenzo[a,e]annulene prepared in step (i), 6 to 8 parts by weight of tetramethyltetravinylcyclotetrasiloxane, 0.7 to 0.8 parts by weight of tri(2-methylphenyl)phosphine, 0.3 to 0.4 parts by weight of palladium acetate, 10 to 12 parts by weight of triethylamine and 39 to 41 parts by weight of tetrahydrofuran are mixed, refluxed at 84 to 86° C. for 23 to 25 hours, cooled to room temperature, added to 150 parts by weight of 1M hydrochloric acid solution, extracted three times with dichloromethane, each time with 66 to 68 parts by weight of dichloromethane, and the organic phase is washed with water until neutral and dried overnight to obtain modified 5,6,11,12-tetrahydrodibenzo[a,e]annulene.

10. The method for preparing a marine heavy-duty anticorrosive coating with a long overcoating interval function according to claim 6, characterized in that: The preparation method of the modified polycaprolactone is as follows: 0.35-0.45 parts by mass of 2,2-dihydroxymethylpropionic acid, 0.6-0.8 parts by mass of N-(2-aminoethyl)maleimide trifluoroacetate and 6.7-6.9 parts by mass of caprolactone are mixed, and then 0.024-0.026 parts by mass of stannous octoate as a catalyst is added, and the mixture is heated to 105° C.-115° C. under nitrogen protection for polymerization for 1.8 h-2.2 h, and then the mixture is heated to 145° C.-155° C. for vacuum reaction for 3.5 h-4.5 h, and then the mixture is heated to 174° C.-176° C. for vacuum reaction for 11.5 h-12.5 h to obtain the modified polycaprolactone.

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