Preparation method of weather-resistant compound containing polyimide structure, obtained compound and application thereof

Abstract

The invention provides a preparation method of a weather-resistant compound containing a polyimide structure, the obtained compound and application thereof. The anhydride compound is adopted as a raw material, molecules of the prepared compound contain a heterocyclic structure, the weather resistance of the compound is improved, the prepared compound is adopted as a curing agent component of the epoxy anticorrosive paint, the high-weather-resistance epoxy anticorrosive paint is prepared, and the weather resistance of epoxy anticorrosive paint is improved. The high-weather-resistance anticorrosive paint is wide in application range, can be used not only under high-temperature and high-humidity conditions, but also at extremely low temperature, and also has a relatively good application prospect in extremely cold areas.

Description

[0001] This divisional application is a divisional application of the invention patent entitled: A weather-resistant compound containing a polyimide structure, an anti-corrosion coating and its preparation and application, with application number: 202211397500.4. The application date of the parent case is November 9, 2022. Technical Field

[0002] The invention belongs to the technical field of coating materials, and in particular relates to a preparation method of a weather-resistant compound containing a polyimide structure, the obtained compound and application thereof. Background Art

[0003] Epoxy resin anticorrosion coatings occupy an important position in marine anticorrosion coatings because of their excellent corrosion resistance, chemical resistance, acid and alkali resistance, high strength, and wear resistance. At present, bisphenol A epoxy resin is commonly used in epoxy resin coatings. This resin is prone to yellowing and powdering under light conditions and has poor weather resistance. During the service of ships, the epoxy anticorrosion coatings used on ships will be exposed to strong ultraviolet rays at sea for a long time, which is prone to coating aging, resulting in a decrease in the anticorrosion performance of the coating, reducing its protective life, and posing a safety hazard to ships in service. Polyimide, as a high-temperature resistant material, contains stable aromatic heterocyclic structural units in its molecules, has excellent high and low temperature resistance, weather resistance, and medium resistance, and has high strength. It is known as the most promising material. Currently, polyimide-modified epoxy resins are commercially available, which improve the toughness and stability of epoxy resins, but their production process is complicated and expensive, and they are not suitable as the base resin of coatings. Chinese patent CN105295792A generates siloxane-terminated polyimide by reacting organic siloxane with soluble polyimide, and then cross-links with silanized epoxy resin. The siloxane group is moisture-cured by the action of a catalyst to form a three-dimensional cross-linked polyimide epoxy resin cured product, thereby improving the heat resistance and stability of the epoxy resin. However, there are few reports on the use of polyimide-modified epoxy resin curing agents. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a weather-resistant compound containing a polyimide structure and a preparation method thereof, as well as the use of the weather-resistant compound containing a polyimide structure in epoxy anti-corrosion coatings. The present invention adopts anhydride compounds as raw materials, so that the prepared compound molecules contain heterocyclic structures, thereby improving the weather resistance of the compound, and adopts the prepared weather-resistant compound containing a polyimide structure as a curing agent for epoxy anti-corrosion coatings to prepare a highly weather-resistant epoxy anti-corrosion coating, thereby improving the weather resistance of the epoxy anti-corrosion coating. The highly weather-resistant anti-corrosion coating has a wide range of applications. It can be used not only under high temperature and high humidity conditions, but also under extremely low temperatures. It also has good application prospects in extremely cold areas.

[0005] One of the objects of the present invention is to provide a weather-resistant compound containing a polyimide structure.

[0006] The weather-resistant compound is obtained by reacting an aminobutene polyimide compound, and the structural formula of the aminobutene polyimide compound is shown in formula (II):

[0007]

[0008] In formula (II), R is a C2-16 aliphatic alkylene group or alicyclic alkylene group.

[0009] The aminobutene polyamide compound is obtained by reacting an anhydride compound and a diamine compound; preferably, the anhydride compound is an alicyclic anhydride compound, preferably maleic anhydride.

[0010] The second object of the present invention is to provide a method for preparing the above-mentioned weather-resistant compound containing a polyimide structure, comprising: heating the aminomaleic polyimide compound under the action of a catalyst to obtain the weather-resistant compound.

[0011] Wherein, in the above preparation method, the catalyst is selected from at least one of an azo catalyst and a peroxide catalyst, preferably at least one of azobisisobutyronitrile, dibenzoyl peroxide, and dodecanoyl peroxide;

[0012] Based on 1 molar portion of the aminomaleic polyimide compound, the amount of the catalyst is 0.002 to 0.01 molar portion, preferably 0.005 to 0.01 molar portion;

[0013] The heating reaction conditions are: 80-100°C for 0.5-2h;

[0014] The heating reaction is carried out in a mixed solvent of acetone and xylene. Preferably, the amount of the mixed solvent is 400-500 mL based on 1 molar portion of the aminomaleic polyimide compound. Acetone and xylene can be added in a commonly used amount ratio in the art, for example, the mass ratio of acetone to xylene is 1:1.

[0015] According to the present invention, the preparation of the weather-resistant compound containing a polyimide structure can adopt the following steps: dissolving a catalyst in a mixed solvent of acetone and xylene to obtain a catalyst solution, slowly dropping the obtained catalyst solution into an aminobutylene polyimide compound solution, reacting at 80 to 100° C. for 0.5 to 2 hours, cooling to 40° C. and discharging the material to obtain the weather-resistant compound containing a polyimide structure.

[0016] According to the present invention, the aminomaleic polyimide compound is obtained by reacting an anhydride compound and a diamine compound. Preferably, the aminomaleic polyimide compound is obtained by the following steps:

[0017] (1) dissolving an acid anhydride compound in an organic solvent, adding a diamine compound, stirring evenly, and heating to react to obtain a polyamic acid solution;

[0018] (2) adding a dehydrating agent and a catalyst to the polyamic acid solution obtained in step (1), heating for reaction, and removing the solvent to obtain the aminomaleic polyimide compound.

[0019] In the preparation method of the above aminomaleic polyimide compound:

[0020] The acid anhydride compound is maleic anhydride;

[0021] The diamine compound is a diamine compound having 2 to 16 carbon atoms, preferably at least one selected from ethylenediamine, hexamethylenediamine, 4,4'-diaminodicyclohexylmethane, and isophoronediamine;

[0022] The dehydrating agent is selected from at least one of acetic anhydride and picoline, preferably acetic anhydride;

[0023] The catalyst is selected from at least one of triethylamine, pyridine and isoquinoline, preferably triethylamine;

[0024] The organic solvent is a mixed solvent of acetone and xylene, wherein acetone and xylene can be added according to a commonly used dosage ratio in the art, for example, the mass ratio of acetone to xylene is 1:1;

[0025] Based on 1 molar portion of the acid anhydride compound, the diamine compound is used in an amount of 0.8 to 1.5 molar portions, the dehydrating agent is used in an amount of 0.5 to 1.5 molar portions, and the catalyst is used in an amount of 0.5 to 1.5 molar portions; preferably, based on 1 molar portion of the acid anhydride compound, the diamine compound is used in an amount of 1 to 1.2 molar portions, the dehydrating agent is used in an amount of 1 to 1.2 molar portions, and the catalyst is used in an amount of 1 to 1.2 molar portions;

[0026] Based on 1 mol of the acid anhydride compound, the amount of the organic solvent is 300 to 650 mL, preferably 400 to 500 mL;

[0027] The heating reaction conditions in step (1) are: 60-70° C. for 2-3 hours;

[0028] The heating reaction conditions in step (2) are: 85-100° C. for 2-8 hours;

[0029] In the step (2), the solvent is removed by rotary evaporation. Preferably, the rotary evaporation conditions are 85-95° C. and 2-6 hours.

[0030] Specifically, the aminomaleic polyimide compound can be prepared by the following steps:

[0031] Step 1: Dissolve maleic anhydride in a mixed solvent of xylene and acetone, then add a diamine compound and stir to mix evenly, gradually raise the temperature to 60°C, react at a temperature of 60-70°C for 2-3h to obtain a polyamic acid solution, the molecular formula of the polyamic acid is as follows:

[0032]

[0033] Step 2: Add a dehydrating agent and a catalyst to the obtained polyamic acid solution, raise the temperature to 85-100°C and react for 2-8 hours to obtain an aminobutene polyimide solution. Use a rotary evaporator to evaporate part of the solvent in the aminobutene polyimide solution and the acetic acid generated in the reaction, maintain the rotary evaporation temperature at 85-95°C, and the rotary evaporation time is 2-6 hours.

[0034] The third object of the present invention is to provide a highly weather-resistant and anti-corrosion coating, comprising the above-mentioned weather-resistant compound containing a polyimide structure or the weather-resistant compound containing a polyimide structure obtained by the above-mentioned preparation method.

[0035] Specifically, the anti-corrosion coating comprises:

[0036] Component A: hydrogenated epoxy resin, pigments, fillers, additives, solvents;

[0037] Component B: curing agent, the curing agent includes the weather-resistant compound containing polyimide structure and amine curing agent.

[0038] In the anticorrosive coating:

[0039] The amine curing agent is selected from modified alicyclic amine curing agents, preferably R-2258, R-2259, R-2261, R-2262, R-2269 from Guangzhou Rich Chemical Company, or preferably one or two of Ancamine 2074, Ancamine 1618, Ancamine 2519 from Air Products and Chemicals of the United States;

[0040] The mass ratio of the amine curing agent to the weather-resistant compound containing a polyimide structure is (1-6):1, preferably (1-3):1;

[0041] The hydrogenated epoxy resin is preferably selected from one of Japan Aidico 4080E, Yantai Oliver AL3040, and Complex High-tech Materials (Shanghai) HE-2010;

[0042] The pigments and fillers can be added with appropriate pigments and fillers according to the specific purpose. For example, zinc chrome yellow, mica iron oxide, iron oxide, aluminum powder, ferrophosphorus powder, composite zinc phosphate, aluminum tripolyphosphate and other fillers with anti-corrosion effect, or functional pigment titanium dioxide, nano-silicon dioxide, organic bentonite, talcum powder, mica powder and other fillers can be selected. Multiple components mentioned above can also be used in combination.

[0043] The auxiliary agent includes at least one of a defoamer, a leveling agent, a wetting and dispersing agent, and an ultraviolet absorber; the auxiliary agent can be an auxiliary agent component commonly used in the art, for example, the defoamer is one or more of Deqian 2700, AFCONA2791, BYK-A530, BYK-028, AFCONA2620, and AFCONA2020, the leveling agent is one or more of Deqian 410, Levalsip432, BYK-322, AFCONA3755, and AFCONA3770, the wetting and dispersing agent is one or more of AFCONAS527, AFCONA4203, and BYK-P104S, and the ultraviolet absorber is one or more of UV1130, UV326, UV123, and UV400;

[0044] The solvent is a mixed solvent of xylene, butanol and cyclohexanone; the proportion of each component in the mixed solvent can be based on the dosage ratio used in the art, for example, the mass ratio of xylene:butanol:cyclohexanone is 4:3:3.

[0045] In the anti-corrosion coating, based on 100 parts by weight of the hydrogenated epoxy resin, the curing agent is 30 to 90 parts, the pigment and filler are 100 to 180 parts, the auxiliary agent is 2 to 25 parts, and the solvent is 10 to 50 parts; preferably, based on 100 parts by weight of the hydrogenated epoxy resin, the curing agent is 40 to 80 parts, the pigment and filler are 110 to 170 parts, the auxiliary agent is 5 to 20 parts, and the solvent is 10 to 40 parts.

[0046] The fourth object of the present invention is to provide a method for preparing the above-mentioned anticorrosive coating, comprising: mixing components including the hydrogenated epoxy resin, pigments, fillers, additives, and solvents to obtain component A, mixing components including a weather-resistant compound containing a polyimide structure and an amine curing agent to obtain component B, and mixing the obtained components A and B to obtain the anticorrosive coating. Preferably, components A and B are uniformly mixed and configured in a weight ratio of (3 to 8):1.

[0047] The fifth object of the present invention is to provide the anticorrosive coating or the anticorrosive coating obtained by the above preparation method, and its application in anticorrosive coating, preferably, the anticorrosive coating is applied to the surface of a substrate to obtain a coating, more preferably, the coating thickness is 240 to 300 μm. The coating method can adopt the commonly used operations in the art, such as brushing, spraying, etc.

[0048] The highly weather-resistant and anti-corrosion coating of the present invention can be cured at room temperature and can be applied to protective coatings that require long-term weather resistance and corrosion resistance, such as hulls or decks of military ships and civilian ships, municipal engineering, bridges and tunnels, industrial facilities, and oil storage tanks. DETAILED DESCRIPTION

[0049] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content recorded in the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the present invention equally.

[0050] The anticorrosive coating performance test methods obtained in the embodiments and comparative examples are as follows:

[0051] Flexibility: GB / T1731 paint film flexibility determination method;

[0052] Adhesion: GB / T 5210 paint and varnish pull-off adhesion test;

[0053] Impact strength: GB / T1732 paint film impact resistance determination method;

[0054] Salt spray resistance: GB / T1771 Determination of neutral salt spray resistance of paints and varnishes;

[0055] Moisture and heat resistance: GB 1740 Determination of moisture and heat resistance of paint film;

[0056] Resistance to salt water (5% NaCl, 30d): GB / T9274 Determination of resistance of paints and varnishes to liquid media;

[0057] Resistance to artificial weathering (UVB, 2000h): GB / T14522 Test method for artificial weathering of plastics, coatings and rubber materials for mechanical industrial products - Fluorescent UV lamp.

[0058] The raw materials used in the examples and comparative examples, unless otherwise specified, are disclosed in the prior art, for example, they can be directly purchased or prepared according to the preparation methods disclosed in the prior art.

[0059] Example 1: Preparation of diamino-2-butanediimide

[0060] Dissolve 98g of maleic anhydride in 400mL of a mixed solvent of xylene and acetone (the mass ratio of xylene to acetone is 1:1), add 60g of ethylenediamine, stir and mix evenly, gradually heat to 60°C, react at 60°C for 3h to obtain a polyamic acid solution. Then add 102.1g of acetic anhydride and 101.2g of triethylamine, raise the temperature to 85°C, react for 4h to obtain a maleic polyimide solution. Transfer the obtained maleic polyimide solution to a rotary evaporator, use a rotary evaporator for rotary evaporation, the rotary evaporation temperature is 90°C, and the rotary evaporation time is 5h. Transfer the solution obtained after rotary evaporation to a reaction bottle, add 29mL of a mixed solvent of xylene and acetone containing 2.4g of dibenzoyl peroxide (the mass ratio of xylene to acetone is 1:1), react at 80°C for 2h, cool to 40°C to discharge, and obtain diamino-2-butanediimide.

[0061] Example 2: Preparation of diamino-2-butanediimide

[0062] Dissolve 98g of maleic anhydride in 500mL of a mixed solvent of xylene and acetone (the mass ratio of xylene to acetone is 1:1), then add 116g of hexamethylenediamine and stir to mix evenly, gradually heat to 70°C, react at 70°C for 2h to obtain a polyamic acid solution. Then add 102.1g of acetic anhydride and 101.2g of triethylamine, raise the temperature to 95°C, and react for 3h to obtain a butene polyimide solution. Transfer the obtained butene polyimide solution to a rotary evaporator, use a rotary evaporator for rotary evaporation, keep the rotary evaporation temperature at 95°C, and the rotary evaporation time is 4h. The solution obtained after rotary evaporation was transferred to a reaction bottle, and 46 mL of a mixed solvent of xylene and acetone (the mass ratio of xylene to acetone was 1:1) containing 1.9 g of dibenzoyl peroxide was added, and the mixture was reacted at 95 ° C for 0.6 h, cooled to 40 ° C, and discharged to obtain diamino-2-butanediimide.

[0063] Example 3: Preparation of highly weather-resistant epoxy anticorrosive coating

[0064] Weigh 100 parts of hydrogenated epoxy resin 4080E into a stainless steel tank and stir with a high-speed stirrer. During the stirring process, add 1 part by weight of defoamer AFCONA2791 and BYK028 (0.5 part by weight of AFCONA2791 and 0.5 part by weight of BYK028), 1 part by weight of leveling agent BYK322, 1 part by weight of wetting and dispersing agent AFCONAS527, and 2 parts by weight of ultraviolet absorber UV1130. After stirring evenly with resin 4080E, add 40 parts by weight of aluminum tripolyphosphate, 20 parts by weight of composite zinc phosphate, 10 parts by weight of iron phosphate powder, 20 parts by weight of talcum powder, 20 parts by weight of mica powder, and 10 parts by weight of mixed solvent xylene, butanol, and cyclohexanone (the mass ratio of xylene: butanol: cyclohexanone is 4:3:3), stir evenly, and then grind to standard fineness with a sand mill or a three-roll grinder, filter and package as component A of the coating.

[0065] Weigh 50 parts by weight of alicyclic amine curing agent (R-2262 from Guangzhou Rich Chemical) and 25 parts by weight of diamino-2-butanediimide prepared in Example 1, and stir them evenly to obtain component B of the coating.

[0066] Component A and component B were mixed and coated on the surface of the substrate to obtain a coating of 240 μm.

[0067] Example 4: Preparation of highly weather-resistant epoxy anticorrosive coating

[0068] Weigh 100 parts of hydrogenated epoxy resin (complex high-tech material HE-2010) into a stainless steel tank and stir with a high-speed stirrer. During the stirring process, add 4 parts by weight of defoamer Deqian 2700, 3 parts by weight of leveling agent Deqian 410, 2 parts by weight of AFCONA3755, 6 parts by weight of wetting and dispersing agent BYK-P104S, and 5 parts by weight of ultraviolet absorber UV326. After stirring evenly with the hydrogenated epoxy resin, add 100 parts by weight of mica iron oxide, 40 parts by weight of zinc chrome yellow, 10 parts by weight of organic bentonite, 15 parts by weight of talc, 5 parts by weight of nano-silicon dioxide, and 30 parts by weight of mixed solvent xylene, butanol, and cyclohexanone (the mass ratio of xylene: butanol: cyclohexanone is 4:3:3), stir evenly, then grind to standard fineness with a sand mill or a three-roll grinder, and filter and package as component A of the coating.

[0069] Weigh 30 parts by weight of alicyclic amine curing agent (R-2259 from Guangzhou Rich Chemical) and 10 parts by weight of diamino-2-butanediimide prepared in Example 1, and stir evenly to obtain component B of the coating.

[0070] Component A and component B were mixed and coated on the surface of the substrate to obtain a coating of 260 μm.

[0071] Example 5: Preparation of highly weather-resistant epoxy anticorrosive coating

[0072] Weigh 100 parts of hydrogenated epoxy resin (Yantai Oliver AL-3040) and put them into a stainless steel tank, stir them with a high-speed stirrer, add 1.2 parts by weight of defoamer BYK-A530, 0.8 parts by weight of AFCONA2020, 3 parts by weight of leveling agent Deqian 432, 3 parts by weight of wetting dispersant AFCONA4203, and 2 parts by weight of ultraviolet absorber UV400 during the stirring process, stir evenly with the hydrogenated epoxy resin, add 30 parts by weight of black iron oxide, 40 parts by weight of aluminum powder, 20 parts by weight of ferrophosphorus powder, 30 parts by weight of titanium dioxide, 20 parts by weight of mica powder, 25 parts by weight of mixed solvent xylene, butanol, and cyclohexanone (xylene: butanol: cyclohexanone mass ratio is 4:3:3), stir evenly, then grind to standard fineness with a sand mill or a three-roll grinder, filter and package as component A of the coating.

[0073] 30 parts by weight of alicyclic amine curing agent (Ancamine 2074, Ancamine 1618) and 25 parts by weight of diamino-2-butanediimide prepared in Example 2 were weighed and stirred evenly to obtain component B of the coating.

[0074] Component A and component B were mixed and coated on the surface of the substrate to obtain a coating of 280 μm.

[0075] Example 6: Preparation of highly weather-resistant epoxy anticorrosive coating

[0076] Weigh 100 parts of hydrogenated epoxy resin 4080E into a stainless steel tank and stir with a high-speed stirrer. During the stirring process, add 0.3 parts by weight of defoamer AFCONA2620, 0.7 parts by weight of AFCONA2791, 2 parts by weight of leveling agent BYK-3755, 1 part by weight of wetting and dispersing agent AFCONA4203, 1 part by weight of BYK104S, 2 parts by weight of ultraviolet absorber UV1130, and 1 part by weight of UV123. After stirring evenly with the resin, add 70 parts by weight of mica iron oxide, 20 parts by weight of black iron oxide, 30 parts by weight of aluminum powder, 30 parts by weight of titanium dioxide, 20 parts by weight of nano-silicon dioxide, and 32 parts by weight of mixed solvent xylene, butanol, and cyclohexanone (xylene: butanol: cyclohexanone mass ratio is 4:3:3), stir evenly, and then grind to standard fineness with a sand mill or a three-roll grinder, filter and package as component A of the coating.

[0077] Weigh 25 parts by weight of alicyclic amine curing agent (R-2258 from Guangzhou Rich Chemical) and 25 parts by weight of diamino-2-butanediimide prepared in Example 2, and stir them evenly to obtain component B of the coating.

[0078] Component A and component B were mixed and coated on the surface of the substrate to obtain a coating of 300 μm.

[0079] Comparative Example 1: Preparation of highly weather-resistant epoxy anticorrosive coating

[0080] Weigh 100 parts of hydrogenated epoxy resin 4080E into a stainless steel tank and stir with a high-speed stirrer. During the stirring process, add 1 part by weight of defoamer AFCONA2791 and BYK028 (0.5 part by weight of AFCONA2791 and 0.5 part by weight of BYK028), 1 part by weight of leveling agent BYK322, 1 part by weight of wetting and dispersing agent AFCONAS527, and 2 parts by weight of ultraviolet absorber UV1130. After stirring evenly with resin 4080E, add 40 parts by weight of aluminum tripolyphosphate, 20 parts by weight of composite zinc phosphate, 10 parts by weight of iron phosphate powder, 20 parts by weight of talcum powder, 20 parts by weight of mica powder, and 10 parts by weight of mixed solvent xylene, butanol, and cyclohexanone (the mass ratio of xylene: butanol: cyclohexanone is 4:3:3), stir evenly, and then grind to standard fineness with a sand mill or a three-roll grinder, filter and package as component A of the coating.

[0081] Weigh 75 parts by weight of alicyclic amine curing agent (R-2258 from Guangzhou Rich Chemical) and stir evenly to obtain component B of the coating.

[0082] Component A and component B were mixed and coated on the surface of the substrate to obtain a coating of 240 μm.

[0083] Comparative Example 2: Preparation of highly weather-resistant epoxy anticorrosive coating

[0084] Weigh 100 parts of hydrogenated epoxy resin 4080E into a stainless steel tank and stir with a high-speed stirrer. During the stirring process, add 1 part by weight of defoamer AFCONA2791 and BYK028 (0.5 part by weight of AFCONA2791 and 0.5 part by weight of BYK028), 1 part by weight of leveling agent BYK322, 1 part by weight of wetting and dispersing agent AFCONAS527, and 2 parts by weight of ultraviolet absorber UV1130. After stirring evenly with resin 4080E, add 40 parts by weight of aluminum tripolyphosphate, 20 parts by weight of composite zinc phosphate, 10 parts by weight of iron phosphate powder, 20 parts by weight of talcum powder, 20 parts by weight of mica powder, and 10 parts by weight of mixed solvent xylene, butanol, and cyclohexanone (the mass ratio of xylene: butanol: cyclohexanone is 4:3:3), stir evenly, and then grind to standard fineness with a sand mill or a three-roll grinder, filter and package as component A of the coating.

[0085] Weigh 75 parts by weight of the diamino-2-butanediimide prepared in Example 1 and stir evenly to obtain component B of the coating.

[0086] Component A and component B were mixed and coated on the surface of the substrate to obtain a coating of 240 μm.

[0087] The performance test results of the anticorrosive coatings obtained in Examples 3 to 6 and Comparative Examples 1 to 2 are shown in Table 1:

[0088] Table 1

[0089]

[0090] It can be seen from the test results in Table 1 that the anti-corrosion coating prepared by the weather-resistant compound containing a polyimide structure in the present invention has more excellent aging resistance.

Claims

1. A method for preparing a weather-resistant compound containing a polyimide structure, comprising: The components including the compound described in the following formula (II) are heated to react under the action of a catalyst to obtain the weather-resistant compound containing a polyimide structure; In formula (II), R is a C2-16 aliphatic alkylene group or alicyclic alkylene group.

2. The preparation method according to claim 1, characterized in that: The catalyst is selected from at least one of an azo catalyst and a peroxide catalyst, preferably at least one of azobisisobutyronitrile, dibenzoyl peroxide, and dodecanoyl peroxide; and / or, Based on 1 molar portion of the compound of formula (II), the amount of the catalyst is 0.002 to 0.01 molar portion, preferably 0.005 to 0.01 molar portion; and / or, The heating reaction conditions are: 80-100°C for 0.5-2h; and / or, The heating reaction is carried out in a mixed solvent of acetone and xylene. Preferably, based on 1 molar portion of the compound of formula (II), the amount of the mixed solvent is 400-500 mL.

3. The preparation method according to claim 1, characterized in that: The compound of formula (II) is obtained by reacting anhydride compounds and diamine compounds.

4. The preparation method according to claim 3, characterized in that: The compound of formula (II) is obtained by the following steps: (1) dissolving an acid anhydride compound in an organic solvent, adding a diamine compound, stirring evenly, and heating to react to obtain a polyamic acid solution; (2) Adding a dehydrating agent and a catalyst to the polyamic acid solution obtained in step (1), heating for reaction, and removing the solvent to obtain the compound of formula (II).

5. The preparation method according to claim 4, characterized in that: The acid anhydride compound is maleic anhydride; and / or, The diamine compound is a diamine compound having 2 to 16 carbon atoms, preferably at least one selected from ethylenediamine, hexamethylenediamine, 4,4'-diaminodicyclohexylmethane, and isophoronediamine; and / or, The dehydrating agent is selected from at least one of acetic anhydride and picoline, preferably acetic anhydride; and / or, The catalyst is selected from at least one of triethylamine, pyridine and isoquinoline, preferably triethylamine; and / or, The organic solvent is a mixed solvent of acetone and xylene; and / or, Based on 1 molar portion of the acid anhydride compound, the diamine compound is used in an amount of 0.8 to 1.5 molar portions, the dehydrating agent is used in an amount of 0.5 to 1.5 molar portions, and the catalyst is used in an amount of 0.5 to 1.5 molar portions; preferably, based on 1 molar portion of the acid anhydride compound, the diamine compound is used in an amount of 1 to 1.2 molar portions, the dehydrating agent is used in an amount of 1 to 1.2 molar portions, and the catalyst is used in an amount of 1 to 1.2 molar portions; and / or, Based on 1 mol of the acid anhydride compound, the amount of the organic solvent is 300 to 650 mL, preferably 400 to 500 mL; and / or, The heating reaction conditions in step (1) are: 60-70° C. for 2-3 hours; and / or, The heating reaction conditions in step (2) are: 85-100° C. for 2-8 hours; and / or, In the step (2), the solvent is removed by rotary evaporation. Preferably, the rotary evaporation conditions are 85-95° C. and 2-6 hours.

6. A weather-resistant compound containing a polyimide structure, prepared by the preparation method according to any one of claims 1 to 5.

7. A highly weather-resistant and anti-corrosion coating, comprising the weather-resistant compound containing a polyimide structure according to claim 6.

8. The anticorrosive coating according to claim 7, characterized in that: The anticorrosive coating comprises: Component A: hydrogenated epoxy resin, pigments, fillers, additives, solvents; Component B: a curing agent, wherein the curing agent includes the weather-resistant compound containing a polyimide structure and an amine curing agent; Preferably, The amine curing agent is selected from modified alicyclic amine curing agents; and / or, The mass ratio of the amine curing agent to the weather-resistant compound containing a polyimide structure is (1-6):1, preferably (1-3):1; and / or, The auxiliary agent includes at least one of a defoamer, a leveling agent, a wetting and dispersing agent, and a UV absorber; and / or, The solvent is a mixed solvent of xylene, butanol and cyclohexanone; and / or, Based on 100 parts by weight of the hydrogenated epoxy resin, the curing agent is 30 to 90 parts, the pigment and filler is 100 to 180 parts, the auxiliary agent is 2 to 25 parts, and the solvent is 10 to 50 parts; preferably, based on 100 parts by weight of the hydrogenated epoxy resin, the curing agent is 40 to 80 parts, the pigment and filler is 110 to 170 parts, the auxiliary agent is 5 to 20 parts, and the solvent is 10 to 40 parts.

9. A method for preparing the anticorrosive coating according to claim 7 or 8, comprising: Components including the hydrogenated epoxy resin, pigments, additives, and solvents are mixed to obtain component A, components including the weather-resistant compound containing a polyimide structure and an amine curing agent are mixed to obtain component B, and the obtained components A and B are mixed to obtain the anti-corrosion coating; preferably, the weight ratio of component A to component B is (3-8):

1.

10. Use of the anti-corrosion coating according to claim 7 or 8 or the anti-corrosion coating obtained by the preparation method according to claim 9 in an anti-corrosion coating. Preferably, the anti-corrosion coating is applied to the surface of a substrate to obtain a coating. More preferably, the coating has a thickness of 240 to 300 μm.

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