Anti-corrosion coating, preparation method therefor, and use thereof, and coated product

Abstract

Disclosed in the present application are an anti-corrosion coating, a preparation method therefor, and a use thereof, and a coated product. The raw material components of the anti-corrosion coating in parts by weight include 30-44 parts of an epoxy resin and 1-10 parts of an organic azole-modified metal-organic framework material.

Description

A corrosion-resistant coating, its preparation method and application, and coated products

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 202410792638.7, filed on June 18, 2024, entitled "An anti-corrosion coating and its preparation method and application, and coated articles thereof," and Chinese Patent Application No. 202410792625.X, filed on June 18, 2024, entitled "An anti-corrosion coating and its preparation method and application, and coated articles thereof," the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of anti-corrosion materials technology, and in particular to an anti-corrosion coating, its preparation method and application, and coated products. Background Technology

[0004] In applications using metallic materials, corrosion of the material surface and metal components can cause incalculable losses. Therefore, it is crucial to provide high-performance, long-term stable anti-corrosion coatings to metal surfaces. Current main technologies involve constructing polymeric anti-corrosion coatings on metal surfaces. One effective solution is to build a highly efficient and dense cross-linked network within a resin system, while simultaneously introducing micro / nano-scale fillers to synergistically improve the coating's resistance to water vapor penetration, damp heat, and stability. It has been reported that highly efficient anti-corrosion effects can be achieved by introducing sheet-like fillers (such as graphite and graphene) and micro / nano-particle materials (such as nano-silica, metal oxide particles, and wollastonite) into resin materials such as E12 epoxy resin and polyester. For example, Chinese patent CN112409884A discloses a coating that combines superhydrophobic surface and graphene shielding effect by introducing graphene oxide-iron oxide nanoparticles into epoxy resin to prepare a coating with dual anti-corrosion effect; CN109957308A discloses an anti-corrosion coating that uses epoxy resin as film-forming material, aluminum sulfate and polyaniline as additives, and aluminum sulfate, graphene and other materials as fillers, which can prevent the penetration of corrosive media and achieve excellent physical barrier anti-corrosion ability of the anti-corrosion coating.

[0005] However, the main method of applying or spraying anti-corrosion coatings to metal surfaces achieves the anti-corrosion effect through physical barriers. However, passive anti-corrosion coatings relying solely on physical barriers, even with the introduction of micro- and nano-fillers, are insufficient to meet the long-term service requirements of metals under harsh environments. When metals are used in long-term high-temperature and high-humidity environments, the presence of water vapor and corrosive ions leads to diffusion and migration. In cases of poor local filler dispersion, defects such as blistering, cracking, and perforation can easily occur in certain weak areas of the anti-corrosion coating, causing localized corrosion, coating failure, and reduced service life of the metal. Furthermore, polymer resin systems cannot completely block water vapor penetration. Resin coatings also suffer from poor aging resistance and low mechanical strength. Under long-term hot water erosion and stress, they are prone to cracking, providing channels for water and ion diffusion and further corroding the metal substrate. This limits the long-term application of resin-based anti-corrosion coatings in humid and hot environments.

[0006] Therefore, providing a coating material that can be used for a long time in humid and hot environments, has good corrosion resistance, and has excellent anti-corrosion effect has become an urgent problem to be solved.

[0007] Summary of the Invention

[0008] This application aims to at least partially solve one of the technical problems existing in the prior art. To this end, this application proposes an anti-corrosion coating, its preparation method and application, and coated articles.

[0009] An embodiment of the first aspect of this application provides an anti-corrosion coating, wherein, by weight, the raw material components of the anti-corrosion coating include: 30-44 parts of epoxy resin and 1-10 parts of organoazole modified metal-organic framework material.

[0010] In some embodiments of this application, the raw material components of the anti-corrosion coating further include: 1 to 12 parts of curing agent, 1 to 28 parts of filler, and 0.1 to 1 part of additive.

[0011] In some embodiments of this application, the raw material components of the anti-corrosion coating, by weight, include: 40-44 parts epoxy resin, 5-8 parts organic azole modified metal-organic framework material, 8-10 parts curing agent, 23-26 parts filler, and 0.5-0.8 parts additives.

[0012] In some embodiments of this application, the epoxy resin is selected from at least one of bisphenol A type epoxy resin, phenolic type epoxy resin, bisphenol F type epoxy resin, and bisphenol S type epoxy resin.

[0013] In some embodiments of this application, the organoazole modified metal-organic framework material is selected from at least one of benzotriazole-metal-organic framework material (BTA-MOF), methylbenzotriazole-metal-organic framework material (TTA-MOF), benzothiazole-metal-organic framework material (Benzothiazole-MOF), and 2-mercaptobenzothiazole-metal-organic framework material (MBT-MOF).

[0014] In some embodiments of this application, the organoazole modified metal-organic framework material is a benzotriazole-metal-organic framework material (BTA-MOF).

[0015] In some embodiments of this application, the curing agent is selected from at least one of imidazole, phenylenediamine, diaminodiphenylmethane, aromatic amine E, m-phenylenediamine, and polyamide.

[0016] In some embodiments of this application, the filler is selected from at least one of talc powder, carbon black, silica, titanium dioxide, mica powder, wollastonite powder, ceramic powder, and glass flakes.

[0017] In some embodiments of this application, the additive is selected from at least one of defoamers, leveling agents, thixotropic agents, coupling agents, antisettling agents, and dispersants.

[0018] An embodiment of the second aspect of this application provides a method for preparing the anti-corrosion coating as described above, comprising the steps of:

[0019] S100, Synthesis of Zn-metal-organic framework materials using a hydrothermal method;

[0020] S200, Add an organoazole ligand to the Zn-metal-organic framework material and react to synthesize an organoazole-modified metal-organic framework material; and

[0021] S300. The organoazole-modified metal-organic framework material and epoxy resin are mixed evenly, then melt-extruded and sieved to obtain the anti-corrosion coating.

[0022] In some embodiments of this application, the organoazole-modified metal-organic framework material, epoxy resin, curing agent, filler, and additives are mixed evenly, then melt-extruded and sieved to obtain the anti-corrosion coating.

[0023] In some embodiments of this application, the weight parts of the organoazole modified metal-organic framework material, epoxy resin, curing agent, filler, and additives are as follows: 30-44 parts of epoxy resin, 1-10 parts of organoazole modified metal-organic framework material, 1-12 parts of curing agent, 1-28 parts of filler, and 0.1-1 parts of additives.

[0024] In some preferred embodiments of this application, the weight parts of the organoazole modified metal-organic framework material, epoxy resin, curing agent, filler, and additives are as follows: 40-44 parts of epoxy resin, 5-8 parts of organoazole modified metal-organic framework material, 8-10 parts of curing agent, 23-26 parts of filler, and 0.5-0.8 parts of additives.

[0025] In some embodiments of this application, the hydrothermal synthesis of Zn-metal-organic framework materials includes:

[0026] Zinc nitrate and 2-thiophenecarboxylic acid were dissolved in a mixed solution of water and methanol; then sodium hydroxide was added, followed by 4,4-bipyridine. After mixing thoroughly, the mixture was placed in a hydrothermal reactor and reacted at 100–150 °C for 8–16 h. After the reaction was completed, the resulting solid was washed and dried to obtain the Zn-organic metal framework material.

[0027] In some embodiments of this application, the step of synthesizing organoazole-modified metal-organic framework materials includes:

[0028] The Zn-metal-organic framework material was dispersed in methanol, and the organic azole ligand was added. The reaction was carried out at 40-70°C for 8-13 hours. After the reaction was completed, the obtained solid was washed and dried to obtain the organic azole-modified metal-organic framework material.

[0029] In some embodiments of this application, the organic azole ligand includes at least one of benzotriazole ligand, methylbenzotriazole ligand, 2-mercaptobenzothiazole ligand, benzimidazole ligand, and benzothiazole ligand.

[0030] In some embodiments of this application, the organoazole modified metal-organic framework material is selected from at least one of benzotriazole-metal-organic framework material (BTA-MOF), methylbenzotriazole-metal-organic framework material (TTA-MOF), benzothiazole-metal-organic framework material (Benzothiazole-MOF), and 2-mercaptobenzothiazole-metal-organic framework material (MBT-MOF).

[0031] In some embodiments of this application, the organoazole ligand is a benzotriazole (BTA) ligand, and the prepared organoazole modified metal-organic framework material is a benzotriazole-metal-organic framework material (BTA-MOF).

[0032] An embodiment of the third aspect of the present invention provides the application of the anti-corrosion coating as described above or the anti-corrosion coating prepared by the preparation method as described above in the corrosion protection of metal substrates.

[0033] In some embodiments of the present invention, the metal substrate includes elemental metals and metal alloys.

[0034] An embodiment of the fourth aspect of the present invention provides an anti-corrosion coating, wherein the anti-corrosion coating prepared by the method described above or prepared by the method described above is uniformly coated onto the surface of a metal substrate by electrostatic spraying, and then cured to obtain the anti-corrosion coating.

[0035] In some embodiments of the present invention, the metal substrate includes elemental metals and metal alloys.

[0036] According to a fifth aspect of the present invention, a coated article is provided, comprising a metal substrate and an anti-corrosion coating as described above or an anti-corrosion coating prepared by the preparation method described above coated on the metal substrate.

[0037] In some embodiments of the present invention, the metal substrate includes elemental metals and metal alloys.

[0038] An embodiment of the sixth aspect of this application provides an anti-corrosion coating, wherein, by weight, the raw material components of the anti-corrosion coating include: 30-44 parts of epoxy resin and 1-10 parts of composite corrosion inhibitor; wherein, the composite corrosion inhibitor includes a Zn-organic metal framework material; the composite corrosion inhibitor further includes at least one of thiourea compounds and inorganic corrosion inhibitors.

[0039] In some embodiments of this application, the raw material components of the anti-corrosion coating, by weight, include: 1 to 4 parts of Zn-organic metal framework material, 0.4 to 2 parts of thiourea compound, and 1 to 4 parts of inorganic corrosion inhibitor.

[0040] In some embodiments of this application, the thiourea compound is selected from at least one of thiourea, acylthiourea, aminothiourea, and thiourea condensate.

[0041] In some embodiments of this application, the inorganic corrosion inhibitor is selected from at least one of silicates, molybdates, and tungstates.

[0042] In some embodiments of this application, the corrosion inhibitor is selected from at least one of sodium silicate, sodium molybdate, and sodium tungstate.

[0043] In some embodiments of this application, the epoxy resin is selected from at least one of bisphenol A type epoxy resin, phenolic type epoxy resin, bisphenol F type epoxy resin, and bisphenol S type epoxy resin.

[0044] In some embodiments of this application, the raw material components of the anti-corrosion coating, by weight, further include: 1-12 parts of curing agent, 1-28 parts of filler, and 0.1-1 parts of additives.

[0045] In some embodiments of this application, the raw material components of the anti-corrosion coating, by weight, include: 40-44 parts epoxy resin, 5-8 parts composite corrosion inhibitor, 8-10 parts curing agent, 23-26 parts filler, and 0.5-0.8 parts additives.

[0046] In some embodiments of this application, the curing agent is selected from at least one of imidazole, phenylenediamine, diaminodiphenylmethane, aromatic amine E, m-phenylenediamine, and polyamide.

[0047] In some embodiments of this application, the filler is selected from at least one of talc powder, carbon black, silica, titanium dioxide, mica powder, wollastonite powder, ceramic powder, and glass flakes.

[0048] In some embodiments of this application, the additive is selected from at least one of defoamers, leveling agents, thixotropic agents, coupling agents, antisettling agents, and dispersants.

[0049] In some embodiments of this application, the raw material components of the anti-corrosion coating, by weight, include: 30-44 parts of epoxy resin and 1-10 parts of composite corrosion inhibitor; wherein, the composite corrosion inhibitor includes Zn-organic metal framework material, thiourea compound, and inorganic corrosion inhibitor.

[0050] In some embodiments of this application, the raw material components of the anti-corrosion coating, by weight, include: 30-44 parts epoxy resin, 1-4 parts Zn-organic metal framework material, 0.4-2 parts thiourea compound, 1-4 parts inorganic corrosion inhibitor, 1-12 parts curing agent, 1-28 parts filler, and 0.1-1 parts additives.

[0051] An embodiment of the seventh aspect of this application provides a method for preparing the anti-corrosion coating as described above, comprising the steps of:

[0052] S100, Synthesis of Zn-metal-organic framework materials using a hydrothermal method;

[0053] S200: The Zn-organic metal framework material, epoxy resin, thiourea compound and / or inorganic corrosion inhibitor are mixed evenly, then melt-extruded and sieved to obtain the anti-corrosion coating.

[0054] In some embodiments of this application, the weight parts of epoxy resin, curing agent, filler, and additives are respectively: 30-44 parts of epoxy resin, 1-12 parts of curing agent, 1-28 parts of filler, and 0.1-1 parts of additives.

[0055] In some embodiments of this application, the molar ratio of the Zn-organic metal framework material to the thiourea compound is (1:1) to (6:1).

[0056] In some embodiments of this application, the molar ratio of the metal-organic framework material to the inorganic corrosion inhibitor is (1:1) to (1:5).

[0057] In some embodiments of this application, the Zn-organic metal framework material is 1 to 4 parts by weight.

[0058] In some embodiments of this application, the thiourea compound is 0.4 to 2 parts by weight.

[0059] In some embodiments of this application, the inorganic corrosion inhibitor is 1 to 4 parts by weight.

[0060] In some embodiments of this application, the weight parts of each component are as follows: 30-44 parts epoxy resin, 1-4 parts Zn-organic metal framework material, 0.4-2 parts thiourea compound, 1-4 parts inorganic corrosion inhibitor, 1-12 parts curing agent, 1-28 parts filler, and 0.1-1 parts additive.

[0061] In some embodiments of this application, the hydrothermal synthesis step includes:

[0062] Zinc nitrate and 2-thiophenecarboxylic acid were dissolved in a mixed solution of water and methanol; then sodium hydroxide was added, followed by 4,4-bipyridine. After mixing thoroughly, the mixture was placed in a hydrothermal reactor and reacted at 100–150 °C for 8–16 h. After the reaction was completed, the resulting solid was washed and dried to obtain the Zn-organic metal framework material.

[0063] An embodiment of the eighth aspect of this application provides the application of the anti-corrosion coating as described above or the anti-corrosion coating prepared by the preparation method as described above in the corrosion protection of metal substrates.

[0064] In some embodiments of this application, the metal substrate includes elemental metals and metal alloys.

[0065] An embodiment of the ninth aspect of this application provides an anti-corrosion coating, wherein the anti-corrosion coating prepared by the method described above or prepared by the method described above is uniformly coated onto the surface of a metal substrate by electrostatic spraying, and then cured to obtain the anti-corrosion coating.

[0066] In some embodiments of this application, the metal substrate includes elemental metals and metal alloys.

[0067] An embodiment of the tenth aspect of this application provides a coated article comprising a metal substrate and an anti-corrosion coating as described above or an anti-corrosion coating prepared by the preparation method described above coated on the metal substrate.

[0068] In some embodiments of this application, the metal substrate includes elemental metals and metal alloys.

[0069] Other features and advantages of this application will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the description, claims and drawings. Detailed Implementation

[0070] The following will clearly and completely describe the concept and technical effects of this application in conjunction with embodiments, so as to fully understand the purpose, features and effects of this application. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are all within the scope of protection of this application.

[0071] In the description of this application, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0072] In the description of this application, unless otherwise stated, the numerical range "a~b" represents a shortened representation of any combination of real numbers between a and b, where a and b are both real numbers. Unless otherwise stated, the various reaction or operation steps may be performed sequentially or not in sequence. Preferably, the reaction methods in this application are performed sequentially.

[0073] Unless otherwise specified in the following examples, the techniques or conditions described in the literature in this field or in accordance with the product instructions shall apply. All reagents or instruments without a specified manufacturer are commercially available conventional products.

[0074] Some embodiments of this application provide an anti-corrosion coating, wherein, by weight, the raw material components of the anti-corrosion coating include: 30-44 parts of epoxy resin and 1-10 parts of organoazole modified metal-organic framework material.

[0075] The anti-corrosion coating provided in this application, targeting epoxy resin as the main material, significantly improves the corrosion resistance of the coating and achieves long-term anti-corrosion by introducing organazole-modified metal-organic framework (MOF) functional fillers. Firstly, this application modifies the surface of the MOF with organazole molecules, which act as bonding sites. The MOF can chelate with the metal surface through these organazole molecules, thereby promoting the formation of a dense physical barrier layer on the metal surface, reducing the penetration of ions and water molecules, and slowing down the corrosion rate of the metal. Simultaneously, utilizing the large specific surface area and good chemical stability of the MOF material, organazole molecules can be loaded inside and on the surface of the MOF nanoframework. Under external temperature and pH stimulation, the organazole molecules inside and outside the framework material are released in response, forming an organic molecular protective film on the metal surface. The anti-corrosion coating of this application, through the synergistic resistance of the physical barrier layer and the organazole molecular protective film, achieves excellent active and passive protection functions, significantly improving the anti-corrosion performance of the coating and meeting the long-term anti-corrosion requirements of metals under long-term humid and hot environments.

[0076] In some embodiments of this application, the raw material components of the anti-corrosion coating, by weight, further include: 1-12 parts of curing agent, 1-28 parts of filler, and 0.1-1 parts of additives.

[0077] In some embodiments of this application, the raw material components of the anti-corrosion coating, by weight, include: 40-44 parts epoxy resin, 5-8 parts organic azole modified metal-organic framework material, 8-10 parts curing agent, 23-26 parts filler, and 0.5-0.8 parts additives.

[0078] In some embodiments of this application, the epoxy resin is selected from at least one of bisphenol A type epoxy resin, phenolic type epoxy resin, bisphenol F type epoxy resin, and bisphenol S type epoxy resin.

[0079] Preferably, the epoxy resin is selected from bisphenol A type epoxy resin. The bisphenol A type epoxy resin can be selected from common types in the art, such as E42 type.

[0080] The anti-corrosion coating provided in this embodiment incorporates MOF nanoparticles loaded with organic azole molecules into epoxy resin. Under external temperature and pH conditions, the organic azole molecules can be effectively released in response, further forming a protective film on the metal surface. Through the combined effect of physical barrier and chemical reaction, the high-temperature resistance of the epoxy resin-based coating is improved.

[0081] In some embodiments of this application, the organoazole modified metal-organic framework material is selected from at least one of benzotriazole-metal-organic framework material (BTA-MOF), methylbenzotriazole-metal-organic framework material (TTA-MOF), benzothiazole-metal-organic framework material (Benzothiazole-MOF), and 2-mercaptobenzothiazole-metal-organic framework material (MBT-MOF).

[0082] The anti-corrosion coating provided in this embodiment modifies the MOF by incorporating organic azole ligands. During the anti-corrosion process, the organic azole molecules can be effectively released in response to external temperature and pH stimuli. The stress-released organic azole molecules, acting as corrosion inhibitors, can form a protective film on the metal substrate, providing excellent protection and improving the coating's corrosion resistance. Through the synergistic effect of physical barrier and responsive release active corrosion protection, the coating's corrosion resistance is significantly enhanced.

[0083] Preferably, the organoazole-modified metal-organic framework material is a benzotriazole-metal-organic framework material (BTA-MOF). This application targets epoxy resin coatings, and by introducing a slow-release agent / metal-organic framework functional filler, the corrosion resistance of the coating can be significantly improved. Benzotriazole (BTA) can form a protective film on the metal surface, reducing the corrosion rate of the metal. Simultaneously, the large specific surface area and good chemical stability of MOF materials allow for the effective loading of BTA onto MOF nanoparticles, enabling the responsive release of the corrosion inhibitor. Based on the physical barrier effect of the coating and the responsive release of the corrosion inhibitor in the MOF, the coating can achieve both active and passive protection functions, significantly improving the anti-corrosion performance of the coating.

[0084] In some embodiments of this application, the curing agent is selected from at least one of imidazole, phenylenediamine, diaminodiphenylmethane, aromatic amine E, m-phenylenediamine, and polyamide.

[0085] In some embodiments of this application, the filler is selected from at least one of talc powder, carbon black, silica, titanium dioxide, mica powder, wollastonite powder, ceramic powder, and glass flakes.

[0086] In some embodiments of this application, the additive is selected from at least one of defoamers, coupling agents, and dispersants.

[0087] In some embodiments of this application, the defoamer is selected from at least one of benzoin (benzoyl ethyl ketone), polyoxypropylene ethylene glycerol ether, polydimethylsiloxane, higher alcohols, and tributyl phosphate.

[0088] In some embodiments of this application, the coupling agent is selected from at least one of organosilane coupling agents, such as KH-560, KH602, methyltriethoxysilane, etc.

[0089] In this application, the curing agents, fillers, additives, etc. mentioned above are listed but not exhaustive, and are intended to illustrate rather than limit. Those skilled in the art will understand that any type of curing agent, filler, additive, etc. commonly used in the art can be reasonably utilized according to actual circumstances.

[0090] Other embodiments of this application provide a method for preparing the anti-corrosion coating as described above, including the following steps:

[0091] S100, Synthesis of Zn-metal-organic framework materials using a hydrothermal method;

[0092] S200: Add an organoazole ligand to the Zn-metal-organic framework material and react to synthesize an organoazole-modified metal-organic framework material.

[0093] S300. The organoazole-modified metal-organic framework material and epoxy resin are mixed evenly, then melt-extruded and sieved to obtain the anti-corrosion coating.

[0094] The method for preparing the anti-corrosion coating provided in this application introduces a slow-release agent / metal-organic framework functional filler into the epoxy resin as the main material. This significantly improves the corrosion resistance of the resulting coating. Through the synergistic resistance of the physical barrier layer and the organic azole molecular protective film, excellent active and passive protection functions are achieved, significantly enhancing the anti-corrosion performance of the coating and meeting the long-term anti-corrosion requirements of metals under prolonged humid and hot environments. Furthermore, the preparation method provided in this application is simple, with mild reaction conditions, easy to operate, and highly efficient, making it suitable for large-scale production applications.

[0095] In some embodiments of this application, the organoazole-modified metal-organic framework material, epoxy resin, curing agent, filler, and additives are mixed evenly, then melt-extruded and sieved to obtain the anti-corrosion coating.

[0096] In some embodiments of this application, the weight parts of the organoazole modified metal-organic framework material, epoxy resin, curing agent, filler, and additives are as follows: 30-44 parts of epoxy resin, 1-10 parts of organoazole modified metal-organic framework material, 1-12 parts of curing agent, 1-28 parts of filler, and 0.1-1 parts of additives.

[0097] In some preferred embodiments of this application, the weight parts of the organoazole modified metal-organic framework material, epoxy resin, curing agent, filler, and additives are as follows: 40-44 parts of epoxy resin, 5-8 parts of organoazole modified metal-organic framework material, 8-10 parts of curing agent, 23-26 parts of filler, and 0.5-0.8 parts of additives.

[0098] In some embodiments of this application, step S100, the step of synthesizing Zn-metal-organic framework materials (Zn-MOF) using a hydrothermal method, includes:

[0099] S101. Dissolve zinc nitrate and 2-thiophenecarboxylic acid in a mixed solution of water and methanol;

[0100] S102, then add sodium hydroxide, then add 4,4-bipyridine, mix well and place in a hydrothermal reactor, react at 100-150℃ for 8-16 hours;

[0101] S103. After the reaction is complete, the obtained solid is washed and dried to obtain the Zn-metal-organic framework material.

[0102] In some embodiments of this application, the molar ratio of zinc nitrate Zn(NO3)2 to 2-thiophenecarboxylic acid is 1:(2-3), preferably 1:2.

[0103] In some embodiments of this application, the molar ratio of zinc nitrate (Zn(NO3)) to 4,4-bipyridine is 1:(2-3), preferably 1:2.

[0104] In some embodiments of this application, the molar ratio of zinc nitrate Zn(NO3)2 to sodium hydroxide is 1:(2-3), preferably 1:2.

[0105] In some embodiments of this application, the water-to-methanol ratio in the mixed solution of water and methanol is 1:1.

[0106] In some embodiments of this application, in step S102, preferably, the reaction is carried out at 130°C for 12 hours in a hydrothermal reactor.

[0107] In some embodiments of this application, step S200, the step of synthesizing the organoazole-modified metal-organic framework material, includes:

[0108] S201. Disperse the Zn-organic metal framework material (Zn-MOF) in methanol, add the organic azole ligand, and react at 40-70°C for 8-13 hours;

[0109] S202. After the reaction is complete, the obtained solid is washed and dried to obtain the organoazole modified metal-organic framework material.

[0110] In some embodiments of this application, the mass ratio of Zn-MOF to organoazole ligand is 1:(4-5), preferably 1:4.

[0111] In some embodiments of this application, the organic azole ligand includes at least one of benzotriazole ligand, methylbenzotriazole ligand, 2-mercaptobenzothiazole ligand, benzimidazole ligand, and benzothiazole ligand.

[0112] Preferably, the organoazole ligand is a benzotriazole (BTA) ligand. The mass ratio of Zn-MOF to BTA is 1:(4-5), preferably 1:4.

[0113] In some embodiments of this application, the organoazole modified metal-organic framework material is selected from at least one of benzotriazole-metal-organic framework material (BTA-MOF), methylbenzotriazole-metal-organic framework material (TTA-MOF), benzothiazole-metal-organic framework material (Benzothiazole-MOF), and 2-mercaptobenzothiazole-metal-organic framework material (MBT-MOF).

[0114] Preferably, the organoazole ligand is a benzotriazole (BTA) ligand, and the prepared organoazole modified metal-organic framework material is a benzotriazole-metal-organic framework material (BTA-MOF). This application targets epoxy resin coatings, and by introducing a slow-release agent / metal-organic framework functional filler, the corrosion resistance of the coating can be significantly improved. Benzotriazole (BTA) can form a protective film on the metal surface, reducing the corrosion rate of the metal. Simultaneously, the large specific surface area and good chemical stability of MOF materials allow for the effective responsive release of corrosion inhibitors by loading BTA onto MOF nanoparticles. Based on the physical barrier of the coating and the responsive release of corrosion inhibitors in the MOF, the coating can achieve both active and passive protection functions, significantly improving the anti-corrosion performance of the coating.

[0115] In some embodiments of this application, in step S201, preferably, the reaction is carried out at 50°C for 10 hours.

[0116] In a specific embodiment of this application, the method for preparing the anti-corrosion coating is as follows:

[0117] (1) Hydrothermal synthesis of Zn-MOF material: 1 mol Zn(NO3)2 and 2 mol 2-thiophenecarboxylic acid were fully dissolved in a 1:1 water:methanol mixture, 2 mol sodium hydroxide was added, and finally 2 mol 4,4-bipyridine was added. The mixture was reacted in a hydrothermal reactor at 130℃ for 12 h. Finally, the mixture was washed and dried to obtain Zn-MOF powder material.

[0118] (2) Preparation of benzotriazole-organic metal framework material (BTA-MOF): 1g Zn-MOF was dispersed in methanol, 4g BTA was added, and the mixture was reacted at 50℃ for 10h. Finally, the mixture was washed and dried to obtain BTA-MOF powder material.

[0119] (3) Preparation of high temperature resistant anti-corrosion coating: Mix BTA-MOF material 1-10 parts by weight, epoxy resin 30-44 parts by weight, curing agent 1-12 parts by weight, filler 1-28 parts by weight, and additives 0.1-1 parts by weight evenly, then melt extrude and grind and sieve to obtain the anti-corrosion coating.

[0120] Other embodiments of this application provide the application of the anti-corrosion coatings described above or prepared by the methods described above in the corrosion protection of metal substrates.

[0121] The anti-corrosion coating obtained in this application is applied to the anti-corrosion of metal substrates. The formed anti-corrosion coating is based on the synergistic resistance of the physical barrier layer and the organic azole molecular protective film, which can achieve excellent active and passive protection functions, significantly improve the anti-corrosion performance of the coating, and can be used for a long time in a humid and hot environment. It has good corrosion resistance and excellent anti-corrosion effect.

[0122] In some embodiments of this application, the metal substrate includes elemental metals and metal alloys.

[0123] Other embodiments of this application provide an anti-corrosion coating, wherein the anti-corrosion coating prepared by the method described above or the method described above is uniformly coated onto the surface of a metal substrate by electrostatic spraying, and then cured to obtain the anti-corrosion coating.

[0124] The anti-corrosion coating provided in this application is obtained by applying the aforementioned anti-corrosion paint, and therefore also has the technical effects of the anti-corrosion paint described above. Based on the synergistic resistance of the physical barrier layer and the organic azole molecular protective film, this anti-corrosion coating can achieve excellent active and passive protection functions, significantly improve the anti-corrosion performance of the coating, and can be used for a long time in a humid and hot environment. It has good corrosion resistance and excellent anti-corrosion effect.

[0125] In some embodiments of this application, the above-mentioned anti-corrosion coating can be prepared into a slurry, and then uniformly coated onto the surface of a metal substrate by scraping, spinning or spraying, and then cured to obtain the anti-corrosion coating, the effect of which is the same as that of the above-mentioned electrostatic spraying.

[0126] In some embodiments of this application, the metal substrate includes elemental metals and metal alloys.

[0127] In some embodiments of this application, the thickness of the anti-corrosion coating is 80–180 μm.

[0128] In some embodiments of this application, the curing process may specifically involve drying at room temperature for 2 hours and then curing in an oven at 200°C for 1 hour, or other commonly used curing methods.

[0129] Other embodiments of this application provide a coated article comprising a metal substrate and an anti-corrosion coating as described above or an anti-corrosion coating prepared by the preparation method described above coated on the metal substrate.

[0130] The coated product provided in this application is obtained by applying the aforementioned anti-corrosion coating, and therefore also possesses the technical effects of the anti-corrosion coating described above. This coated product can achieve both active and passive anti-corrosion functions, significantly improving the anti-corrosion performance of metal substrates. It can be used for extended periods in harsh environments such as high temperature, high humidity, and hot water, exhibiting good corrosion resistance and excellent anti-corrosion effects.

[0131] In some embodiments of this application, the metal substrate includes elemental metals and metal alloys.

[0132] Other embodiments of this application provide the application of the above-described coated articles in the field of home appliances.

[0133] In some embodiments of this application, the above-mentioned coated articles can be applied to the field of home appliances, including refrigeration appliances (e.g., household refrigerators, beverage coolers, etc.), air conditioners (e.g., room air conditioners, electric fans, exhaust fans, hot and cold air heaters, dehumidifiers, air coolers, humidifiers, etc.), cleaning appliances (e.g., washing machines, dryers, electric irons, vacuum cleaners, floor waxers, robot vacuum cleaners, etc.), kitchen appliances (e.g., electric stoves, microwave ovens, induction cookers, electric ovens, rice cookers, dishwashers, food processors, etc.), electric heating appliances (e.g., space heaters), and audio-visual appliances (e.g., mini projectors, televisions, radios, tape recorders, video recorders, cameras, stereo systems, etc.).

[0134] Other features and advantages of this application will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the description, claims and drawings.

[0135] Example 1

[0136] (1) Hydrothermal synthesis of Zn-MOF material: 1 mol Zn(NO3)2 and 2 mol 2-thiophenecarboxylic acid were fully dissolved in a 1:1 water:methanol mixture, 2 mol sodium hydroxide was added, and finally 2 mol 4,4-bipyridine was added. The mixture was reacted in a hydrothermal reactor at 130℃ for 12 h. Finally, it was washed and dried to obtain Zn-MOF powder material.

[0137] (2) Preparation of benzotriazole-organic metal framework material (BTA-MOF): 1g Zn-MOF was dispersed in methanol, 4g BTA was added, and the mixture was reacted at 50℃ for 10h. Finally, the mixture was washed and dried to obtain BTA-MOF powder material.

[0138] (3) Preparation of anti-corrosion composite coating: By weight, 42 parts of bisphenol A epoxy resin, 8 parts of BTA-MOF powder, 10 parts of imidazole, 26 parts of talc powder and 0.6 parts of benzoin are thoroughly mixed, then melt-extruded and sieved to obtain composite coating powder.

[0139] (4) The obtained coating powder is electrostatically sprayed onto the surface of alloy steel Q420 and then cured to obtain an anti-corrosion composite coating.

[0140] The coating thickness is 156 μm.

[0141] Example 2

[0142] The difference from Example 1 lies in the coating formulation. In this example, by weight, the composition is 44 parts bisphenol A epoxy resin, 5 parts BTA-MOF powder, 8 parts imidazole, 24 parts talc, and 0.8 parts benzoin. All other components are the same as in Example 1.

[0143] Example 3

[0144] The difference from Example 1 lies in the coating formulation. In this example, by weight, the coating consists of 35 parts bisphenol A epoxy resin, 2 parts BTA-MOF powder, 10 parts imidazole, 26 parts talc, and 0.6 parts benzoin. All other components are the same as in Example 1.

[0145] Example 4

[0146] The difference from Example 1 is that in step (1), the amounts of Zn(NO3)2, 2-thiophenecarboxylic acid, and 4,4-bipyridine are 1 mol, 3 mol, and 3 mol, respectively. Everything else is the same as in Example 1.

[0147] Example 5

[0148] The difference from Example 1 is that in step (1), the reaction is carried out at 150°C for 10 hours in a hydrothermal reactor. Everything else is the same as in Example 1.

[0149] Example 6

[0150] The difference from Example 1 is that in step (2), the amounts of Zn-MOF and BTA are 1g and 5g, respectively. Everything else is the same as in Example 1.

[0151] Example 7

[0152] The difference from Example 1 is that in step (2), the reaction is carried out at 60°C for 8 hours. Everything else is the same as in Example 1.

[0153] Comparative Example 1

[0154] (1) Hydrothermal synthesis of Zn-MOF material: 1 mol Zn(NO3)2 and 2 mol 2-thiophenecarboxylic acid were fully dissolved in a 1:1 water:methanol mixed solution, 2 mol sodium hydroxide was added, and finally 2 mol 4,4-bipyridine was added. The reaction was carried out in a hydrothermal reactor at 130℃ for 12 h. Finally, the mixture was washed and dried to obtain Zn-MOF powder material.

[0155] (2) Preparation of epoxy resin composite coating: By weight, 42 parts of bisphenol A epoxy resin, 8 parts of Zn-MOF powder, 10 parts of imidazole, 26 parts of talc powder and 0.6 parts of benzoin are thoroughly mixed, then melt-extruded and sieved to obtain composite coating powder.

[0156] (3) The obtained coating powder is electrostatically sprayed onto the surface of alloy steel Q420 and then cured to obtain an epoxy resin composite coating.

[0157] The coating thickness is 156 μm.

[0158] Comparative Example 2

[0159] (1) By weight, 42 parts of bisphenol A epoxy resin, 10 parts of imidazole, 26 parts of talc and 0.6 parts of benzoin are thoroughly mixed, then melt-extruded and sieved to obtain coating powder.

[0160] (2) The obtained coating powder is electrostatically sprayed onto the surface of alloy steel Q420 and then cured to obtain an epoxy resin coating.

[0161] The coating thickness is 156 μm.

[0162] Test case

[0163] The corrosion resistance of the coatings in Examples 1-7 and Comparative Examples 1-2 was evaluated using a scratch test. The method was as follows: Prepared coating samples were taken, and scratches were made on their surfaces. The scratches on the sample surfaces were of uniform size. The coating samples were then placed in a salt spray chamber for 7 days. After the salt spray test, the surface of the samples was inspected according to GB / T 10125-2021. The results are shown in Table 1.

[0164] Table 1

[0165] The corrosion resistance of the anti-corrosion coating was evaluated by a cross-cutting test. It was found that the pure epoxy resin coating showed obvious peeling and a large amount of corrosion products on the substrate. For the composite coating with Zn-MOF material, obvious substrate corrosion products were found at the cross-cutting points, and the coating only peeled off slightly. For the composite coating with BTA-MOF material, the degree of corrosion was the least, with only slight corrosion products at the cross-cutting points. This is because the BTA corrosion inhibitor released under stress can form a protective film on the metal substrate, playing a good protective role and improving the corrosion resistance of the coating.

[0166] The high-temperature resistance and long-term corrosion resistance of Examples 1-7 and Comparative Examples 1-2 were tested. The method was as follows: coating samples were taken and immersed in hot water at 95°C for 7 days. The surface of the samples was then observed (test standard GB / T 1733-1993) and their electrochemical impedance was measured (test standard GB / T 39482-2020). The results are shown in Table 2.

[0167] Table 2

[0168] For the coatings prepared in the examples and comparative examples, the initial electrochemical impedance was 10^12 Ω. After soaking in hot water at 95°C for 7 days, the composite coating with added BTA-MOF material showed significantly better corrosion resistance than the pure epoxy resin coating and the Zn-MOF material coating due to the synergistic resistance of the physical barrier layer and the organic azole molecular protective film.

[0169] Other embodiments of this application also provide an anti-corrosion coating, wherein, by weight, the raw material components of the anti-corrosion coating include: 30-44 parts of epoxy resin and 1-10 parts of composite corrosion inhibitor; wherein, the composite corrosion inhibitor includes a Zn-organic metal framework material; the composite corrosion inhibitor also includes at least one of thiourea compounds and inorganic corrosion inhibitors.

[0170] The anti-corrosion coating provided in this application, targeting epoxy resin as the main material, significantly improves the corrosion resistance of the coating by introducing a multi-component composite corrosion inhibitor. On one hand, the composite corrosion inhibitor includes a Zn-metal-organic framework (Zn-MOF). Utilizing the large specific surface area and good chemical stability of MOF materials, thiourea or inorganic corrosion inhibitor molecules can be loaded inside and on the surface of the MOF nanoframework, releasing in response to external environmental stimuli. On the other hand, thiourea compound molecules can interact with the metal cations (e.g., Fe) of the metal substrate through S atoms. 3+The inorganic corrosion inhibitor forms a coordination layer on the metal substrate surface, adsorbing and forming a hydrophobic protective film that effectively inhibits corrosion. Meanwhile, the inorganic corrosion inhibitor can be uniformly deposited on the metal surface, and the covalent bonds in its molecules can form a complex with the metal surface, further covering the active sites of the metal corrosion reaction and forming a denser protective layer. Therefore, this application utilizes the slow-release properties of MOF, the coordination effect of thiourea compounds, and / or the complexing effect of inorganic corrosion inhibitors, combined with the cross-linking effect of epoxy resin and the barrier properties of MOF fillers, to meet the long-term corrosion protection requirements of metals under prolonged humid and hot environments.

[0171] In some embodiments of this application, the molar ratio of the Zn-organic metal framework material (Zn-MOF) to the thiourea compound is (1:1) to (6:1), preferably 1:1.

[0172] The molar ratio of the eZn-organic metal framework material (Zn-MOF) to the inorganic corrosion inhibitor is (1:1) to (1:5), preferably 1:3.

[0173] In some embodiments of this application, the Zn-organic metal framework material is 1 to 4 parts by weight.

[0174] In some embodiments of this application, the thiourea compound is 0.4 to 2 parts by weight.

[0175] In some embodiments of this application, the inorganic corrosion inhibitor is 1 to 4 parts by weight.

[0176] In some embodiments of this application, the thiourea compound is selected from at least one of thiourea, acylthiourea, aminothiourea, and thiourea condensate, preferably thiourea.

[0177] In some embodiments of this application, the inorganic corrosion inhibitor is selected from at least one of silicates, molybdates, and tungstates, preferably silicates.

[0178] In some embodiments of this application, the corrosion inhibitor is selected from at least one of sodium silicate, sodium molybdate, and sodium tungstate, preferably sodium silicate.

[0179] In some preferred embodiments of this application, the raw material components of the anti-corrosion coating, by weight, include: 30-44 parts epoxy resin and 1-10 parts composite corrosion inhibitor; wherein the composite corrosion inhibitor includes 1-4 parts Zn-organic metal framework material, 0.4-2 parts thiourea compound, and 1-4 parts inorganic corrosion inhibitor.

[0180] In some more preferred embodiments of this application, the raw material components of the anti-corrosion coating, by weight, include: 30-44 parts of epoxy resin and 1-10 parts of composite corrosion inhibitor; wherein the composite corrosion inhibitor includes 1-4 parts of Zn-organic metal framework material, 0.4-2 parts of thiourea, and 1-4 parts of sodium silicate.

[0181] The anti-corrosion coating provided in this application, targeting epoxy resin as the main material, significantly improves the corrosion resistance of the coating by introducing a multi-component composite corrosion inhibitor. The composite corrosion inhibitor includes a Zn-metal-organic framework (Zn-MOF) material. Utilizing the large specific surface area and good chemical stability of MOF materials, thiourea or sodium silicate molecules can be loaded inside and on the surface of the MOF nanoframework material, releasing in response to external environmental stimuli. The composite corrosion inhibitor also includes thiourea, whose molecules can interact with metal cations (e.g., Fe) in the metal substrate through sulfur atoms. 3+ The composite corrosion inhibitor forms a coordination layer, adsorbing onto the metal substrate surface to form a hydrophobic protective film, effectively inhibiting corrosion. On the other hand, the composite corrosion inhibitor also includes sodium silicate; the silicon-oxygen bonds in the sodium silicate molecule can form a complex with the metal surface, further covering the active sites of the metal corrosion reaction, and can be uniformly deposited on the metal surface to form a denser protective layer. Therefore, the composite corrosion inhibitor of this application, through the dual organic-inorganic protective layer formed by coordination and complexation, can efficiently and synergistically improve the corrosion resistance of the metal surface coating. Finally, this application utilizes the slow release of MOF, and the dual organic-inorganic protective layer formed by coordination and complexation, combined with the crosslinking effect of epoxy resin and the barrier properties of MOF filler, to meet the long-term corrosion protection requirements of metals under long-term humid and hot environments.

[0182] In some embodiments of this application, the epoxy resin is selected from at least one of bisphenol A type epoxy resin, phenolic type epoxy resin, bisphenol F type epoxy resin, and bisphenol S type epoxy resin.

[0183] Preferably, the epoxy resin is selected from bisphenol A type epoxy resin. The bisphenol A type epoxy resin can be selected from common types in the art, such as E42 type.

[0184] In some embodiments of this application, the raw material components of the anti-corrosion coating, by weight, further include: 1-12 parts of curing agent, 1-28 parts of filler, and 0.1-1 parts of additives.

[0185] In some preferred embodiments of this application, the raw material components of the anti-corrosion coating, by weight, include: 30-44 parts epoxy resin, 1-4 parts Zn-organic metal framework material, 0.4-2 parts thiourea compound, 1-4 parts inorganic corrosion inhibitor, 1-12 parts curing agent, 1-28 parts filler, and 0.1-1 parts additives.

[0186] In some preferred embodiments of this application, the raw material components of the anti-corrosion coating, by weight, include: 40-44 parts epoxy resin, 5-8 parts composite corrosion inhibitor, 8-10 parts curing agent, 23-26 parts filler, and 0.5-0.8 parts additives.

[0187] In some embodiments of this application, the curing agent is selected from at least one of imidazole, phenylenediamine, diaminodiphenylmethane, aromatic amine E, m-phenylenediamine, and polyamide.

[0188] In some embodiments of this application, the filler is selected from at least one of talc powder, carbon black, silica, titanium dioxide, mica powder, wollastonite powder, ceramic powder, and glass flakes.

[0189] In some embodiments of this application, the additive is selected from at least one of defoamers, leveling agents, thixotropic agents, coupling agents, antisettling agents, and dispersants.

[0190] In some embodiments of this application, the defoamer is selected from at least one of benzoin (benzoyl ethyl ketone), polyoxypropylene ethylene glycerol ether, polydimethylsiloxane, higher alcohols, and tributyl phosphate.

[0191] In some embodiments of this application, the leveling agent is selected from at least one of water-based fluorosilicone leveling agents.

[0192] In some embodiments of this application, the thixotropic agent is selected from at least one of aqueous polyamide thixotropic agents.

[0193] In some embodiments of this application, the coupling agent is selected from at least one of organosilane coupling agents, such as KH-560, KH602, methyltriethoxysilane, etc.

[0194] In some embodiments of this application, the anti-settling agent includes, but is not limited to, organomontmorillonite.

[0195] In some embodiments of this application, the dispersant is selected from at least one of aqueous dispersants.

[0196] In this application, the curing agents, fillers, additives, etc. mentioned above are listed but not exhaustive, and are intended to illustrate rather than limit. Those skilled in the art will understand that any type of curing agent, filler, additive, etc. commonly used in the art can be reasonably utilized according to actual circumstances.

[0197] Other embodiments of this application provide a method for preparing the anti-corrosion coating as described above, including the following steps:

[0198] S100, Synthesis of Zn-metal-organic framework materials using a hydrothermal method;

[0199] S200: The Zn-organic metal framework material, epoxy resin, thiourea compound and / or inorganic corrosion inhibitor are mixed evenly, then melt-extruded and sieved to obtain the anti-corrosion coating.

[0200] The method for preparing the anti-corrosion coating provided in this application introduces a multi-component composite corrosion inhibitor into the main material, epoxy resin. Utilizing the slow-release effect of MOF (Metal-Oxide-Foil) in the composite corrosion inhibitor, the coordination effect of thiourea compounds, and / or the complexation effect of inorganic corrosion inhibitors, combined with the cross-linking effect of epoxy resin and the barrier properties of MOF fillers, it can meet the long-term corrosion protection requirements of metals under prolonged humid and hot environments. Furthermore, the preparation method provided in this application is simple, has mild reaction conditions, is easy to operate, and has high production efficiency, making it suitable for large-scale production applications.

[0201] In some embodiments of this application, the weight parts of epoxy resin, curing agent, filler, and additives are respectively: 30-44 parts of epoxy resin, 1-12 parts of curing agent, 1-28 parts of filler, and 0.1-1 parts of additives.

[0202] In some embodiments of this application, the molar ratio of the Zn-organic metal framework material (Zn-MOF) to the thiourea compound is (1:1) to (6:1), preferably 1:1.

[0203] In some embodiments of this application, the molar ratio of the Zn-metal-organic framework material (Zn-MOF) to the inorganic corrosion inhibitor is (1:1) to (1:5), preferably 1:3.

[0204] In some embodiments of this application, the Zn-organic metal framework material is 1 to 4 parts by weight.

[0205] In some embodiments of this application, the thiourea compound is 0.4 to 2 parts by weight.

[0206] In some embodiments of this application, the inorganic corrosion inhibitor is 1 to 4 parts by weight.

[0207] In some embodiments of this application, the thiourea compound is selected from at least one of thiourea, acylthiourea, aminothiourea, and thiourea condensate, preferably thiourea.

[0208] In some embodiments of this application, the inorganic corrosion inhibitor is selected from at least one of silicates, molybdates, and tungstates, preferably silicates.

[0209] In some embodiments of this application, the corrosion inhibitor is selected from at least one of sodium silicate, sodium molybdate, and sodium tungstate, preferably sodium silicate.

[0210] In some embodiments of this application, the raw material components of the anti-corrosion coating, by weight, further include: 1-12 parts of curing agent, 1-28 parts of filler, and 0.1-1 parts of additives.

[0211] In some preferred embodiments of this application, the raw material components of the anti-corrosion coating, by weight, include: 30-44 parts epoxy resin and 1-10 parts composite corrosion inhibitor; wherein the composite corrosion inhibitor includes 1-4 parts Zn-organic metal framework material, 0.4-2 parts thiourea compound, and 1-4 parts inorganic corrosion inhibitor.

[0212] In some more preferred embodiments of this application, the raw material components of the anti-corrosion coating, by weight, include: 30-44 parts of epoxy resin and 1-10 parts of composite corrosion inhibitor; wherein the composite corrosion inhibitor includes 1-4 parts of Zn-organic metal framework material, 0.4-2 parts of thiourea, and 1-4 parts of sodium silicate.

[0213] In some preferred embodiments of this application, the method for preparing the anti-corrosion coating includes the following steps: synthesizing a Zn-organic metal framework material using a hydrothermal method; mixing the Zn-organic metal framework material, epoxy resin, thiourea compound, inorganic corrosion inhibitor, curing agent, filler, and additives evenly, then melting and extruding the mixture and grinding it to obtain the anti-corrosion coating.

[0214] In some embodiments of this application, step S100, the hydrothermal synthesis of Zn-metal-organic framework materials (Zn-MOF), includes:

[0215] S101. Dissolve zinc nitrate and 2-thiophenecarboxylic acid in a mixed solution of water and methanol;

[0216] S102, then add sodium hydroxide, then add 4,4-bipyridine, mix well and place in a hydrothermal reactor, react at 100-150℃ for 8-16 hours;

[0217] S103. After the reaction is complete, the obtained solid is washed and dried to obtain the Zn-metal-organic framework material.

[0218] In some embodiments of this application, the molar ratio of zinc nitrate Zn(NO3)2 to 2-thiophenecarboxylic acid is 1:(2-3), preferably 1:2.

[0219] In some embodiments of this application, the molar ratio of zinc nitrate (Zn(NO3)) to 4,4-bipyridine is 1:(2-3), preferably 1:2.

[0220] In some embodiments of this application, the molar ratio of zinc nitrate Zn(NO3)2 to sodium hydroxide is 1:(2-3), preferably 1:2.

[0221] In some embodiments of this application, the water-to-methanol ratio in the mixed solution of water and methanol is 1:1.

[0222] In some embodiments of this application, in step S102, preferably, the reaction is carried out at 130°C for 12 hours in a hydrothermal reactor.

[0223] In a specific embodiment of this application, the method for preparing the anti-corrosion coating is as follows:

[0224] (1) Hydrothermal synthesis of Zn-MOF material: 1 mol Zn(NO3)2 and 2 mol 2-thiophenecarboxylic acid were fully dissolved in a 1:1 water:methanol mixture, 2 mol sodium hydroxide was added, and finally 2 mol 4,4-bipyridine was added. The mixture was reacted in a hydrothermal reactor at 130℃ for 12 h. Finally, the mixture was washed and dried to obtain Zn-MOF powder material.

[0225] (2) Preparation of high temperature resistant anti-corrosion coating: 30-44 parts of epoxy resin, 1-4 parts of Zn-MOF material, 0.4-2 parts of thiourea, 1-4 parts of sodium silicate, 1-12 parts by weight of curing agent, 1-28 parts by weight of filler and 0.1-1 parts by weight of additives are mixed evenly, then melt-extruded and sieved to obtain the anti-corrosion coating.

[0226] Other embodiments of this application provide the application of the anti-corrosion coatings described above or prepared by the methods described above in the corrosion protection of metal substrates.

[0227] The anti-corrosion coating obtained in this application is applied to the anti-corrosion of metal substrates. The resulting anti-corrosion coating utilizes the slow release of MOF in the composite corrosion inhibitor, as well as the coordination effect of thiourea compound molecules and / or the complexation effect of inorganic corrosion inhibitors, which can significantly improve the anti-corrosion performance of the coating. At the same time, combined with the cross-linking effect of epoxy resin and the barrier properties of MOF filler, it can be used for a long time in humid and hot environments, has good corrosion resistance, and has excellent anti-corrosion effect.

[0228] In some embodiments of this application, the metal substrate includes elemental metals and metal alloys.

[0229] Other embodiments of this application provide an anti-corrosion coating, wherein the anti-corrosion coating prepared by the method described above or the method described above is uniformly coated onto the surface of a metal substrate by electrostatic spraying, and then cured to obtain the anti-corrosion coating.

[0230] The anti-corrosion coating provided in this application is obtained by electrostatic spraying of the aforementioned anti-corrosion coating, and therefore also has the technical effects of the anti-corrosion coating described above. This anti-corrosion coating utilizes the slow-release effect of MOF in the composite corrosion inhibitor, the coordination effect of thiourea compound molecules, and / or the complexation effect of inorganic corrosion inhibitors to significantly improve the anti-corrosion performance of the coating. Simultaneously, combined with the cross-linking effect of epoxy resin and the barrier properties of MOF filler, it can be used for a long time in humid and hot environments, exhibits good corrosion resistance, and has excellent anti-corrosion effects.

[0231] In some embodiments of this application, the above-mentioned anti-corrosion coating can be prepared into a slurry, and then uniformly coated onto the surface of a metal substrate by scraping, spinning or spraying, and then cured to obtain the anti-corrosion coating, the effect of which is the same as that of the above-mentioned electrostatic spraying.

[0232] In some embodiments of this application, the metal substrate includes elemental metals and metal alloys.

[0233] In some embodiments of this application, the thickness of the anti-corrosion coating is 80–180 μm.

[0234] In some embodiments of this application, the curing process may specifically involve drying at room temperature for 2 hours and then curing in an oven at 200°C for 1 hour, or other commonly used curing methods.

[0235] Other embodiments of this application provide a coated article comprising a metal substrate and an anti-corrosion coating as described above or an anti-corrosion coating prepared by the preparation method described above coated on the metal substrate.

[0236] The coated product provided in this application is obtained by applying the aforementioned anti-corrosion coating, and therefore also possesses the technical effects of the anti-corrosion coating described above. This coated product utilizes the slow-release effect of MOF in the composite corrosion inhibitor, the coordination effect of thiourea compound molecules, and / or the complexation effect of inorganic corrosion inhibitors to significantly improve the anti-corrosion performance of the coating. Simultaneously, combined with the cross-linking effect of epoxy resin and the barrier properties of MOF filler, it can be used for extended periods in humid and hot environments, exhibits good corrosion resistance, and demonstrates excellent anti-corrosion effects.

[0237] In some embodiments of this application, the metal substrate includes elemental metals and metal alloys.

[0238] Other embodiments of this application provide the application of the above-described coated articles in the field of home appliances.

[0239] In some embodiments of this application, the household appliances include refrigeration appliances (e.g., household refrigerators, beverage coolers, etc.), air conditioners (e.g., room air conditioners, electric fans, exhaust fans, hot and cold air heaters, dehumidifiers, evaporative coolers, humidifiers, etc.), cleaning appliances (e.g., washing machines, dryers, electric irons, vacuum cleaners, floor waxers, robot vacuum cleaners, etc.), kitchen appliances (e.g., electric stoves, microwave ovens, induction cookers, electric ovens, rice cookers, dishwashers, food processors, etc.), electric heating appliances (e.g., space heaters), and audio-visual appliances (e.g., mini projectors, televisions, radios, tape recorders, video recorders, cameras, stereo systems, etc.).

[0240] Other features and advantages of this application will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the description, claims and drawings.

[0241] Example 8

[0242] (1) Hydrothermal synthesis of Zn-MOF material: 1 mol Zn(NO3)2 and 2 mol 2-thiophenecarboxylic acid were fully dissolved in a 1:1 water:methanol mixture, 2 mol sodium hydroxide was added, and finally 2 mol 4,4-bipyridine was added. The mixture was reacted in a hydrothermal reactor at 130℃ for 12 h. Finally, it was washed and dried to obtain Zn-MOF powder material.

[0243] (2) Preparation of anti-corrosion composite coating: By weight, 42 parts of bisphenol A epoxy resin, 1 part of Zn-MOF material, 1 part of thiourea, 3 parts of sodium silicate, 10 parts of imidazole, 26 parts of talc powder and 0.6 parts of benzoin are thoroughly mixed, then melt-extruded and sieved to obtain composite coating powder.

[0244] (3) The obtained coating powder is electrostatically sprayed onto the surface of alloy steel Q420 and then cured to obtain an anti-corrosion composite coating.

[0245] The coating thickness is 167 μm.

[0246] Example 9

[0247] The difference from Example 1 lies in the coating formulation. In this example, by weight, the coating consists of 44 parts bisphenol A epoxy resin, 2 parts Zn-MOF material, 0.8 parts thiourea, 3 parts sodium silicate, 8 parts imidazole, 24 parts talc, and 0.8 parts benzoin. All other components are the same as in Example 1.

[0248] Example 10

[0249] The difference from Example 1 lies in the coating formulation. In this example, by weight, the coating consists of 35 parts bisphenol A epoxy resin, 4 parts Zn-MOF material, 2 parts thiourea, 4 parts sodium silicate, 10 parts imidazole, 28 parts talc, and 0.6 parts benzoin. All other components are the same as in Example 1.

[0250] Example 11

[0251] The difference from Example 1 lies in the coating formulation. In this example, by weight, the coating consists of 42 parts bisphenol A epoxy resin, 1 part Zn-MOF material, 3 parts sodium silicate, 10 parts imidazole, 26 parts talc, and 0.6 parts benzoin. All other components are the same as in Example 1.

[0252] Example 12

[0253] The difference from Example 1 is the coating formulation. In this example, by weight, there are 42 parts of bisphenol A epoxy resin, 1 part of Zn-MOF material, 1 part of thiourea, 10 parts of imidazole, 26 parts of talc, and 0.6 parts of benzoin. Everything else is the same as in Example 1.

[0254] Comparative Example 3

[0255] (1) Hydrothermal synthesis of Zn-MOF material: 1 mol Zn(NO3)2 and 2 mol 2-thiophenecarboxylic acid were fully dissolved in a 1:1 water:methanol mixed solution, 2 mol sodium hydroxide was added, and finally 2 mol 4,4-bipyridine was added. The reaction was carried out in a hydrothermal reactor at 130℃ for 12 h. Finally, the mixture was washed and dried to obtain Zn-MOF powder material.

[0256] (2) Preparation of epoxy resin composite coating: By weight, 42 parts of bisphenol A epoxy resin, 10 parts of Zn-MOF powder, 10 parts of imidazole, 26 parts of talc powder and 0.6 parts of benzoin are thoroughly mixed and then melt-extruded and sieved to obtain composite coating powder.

[0257] (3) The obtained coating powder is electrostatically sprayed onto the surface of alloy steel Q420 and then cured to obtain an epoxy resin composite coating.

[0258] The coating thickness is 167 μm.

[0259] Comparative Example 4

[0260] (1) By weight, 42 parts of bisphenol A epoxy resin, 10 parts of imidazole, 26 parts of talc and 0.6 parts of benzoin are thoroughly mixed, then melt-extruded and sieved to obtain coating powder.

[0261] (2) The obtained coating powder is electrostatically sprayed onto the surface of alloy steel Q420 and then cured to obtain an epoxy resin coating.

[0262] The coating thickness is 167 μm.

[0263] Test case

[0264] The corrosion resistance of the coatings in Examples 8-12 and Comparative Examples 3-4 was evaluated using a scratch test. The method was as follows: Prepared coating samples were taken, and scratches were made on their surfaces. The scratches were of uniform size. The samples were then placed in a salt spray chamber for 7 days. After the salt spray test, the surface of the samples was inspected according to GB / T 10125-2021. The results are shown in Table 3.

[0265] Table 3

[0266] The corrosion resistance of the anti-corrosion coatings was evaluated using a cross-cutting test. The results showed that the pure epoxy resin coating exhibited significant peeling and a large amount of corrosion products on the substrate. For the composite coating with Zn-MOF, significant substrate corrosion products were observed at the cross-cutting points, with only slight coating peeling. The composite coating with Zn-MOF and thiourea showed less corrosion, with only slight corrosion products at the cross-cutting points. The composite coating with Zn-MOF, thiourea, and sodium silicate showed even weaker corrosion. This is because the small-molecule thiourea can interact with the alloy steel through sulfur atoms, adsorbing onto the alloy steel surface to form a hydrophobic protective film, effectively inhibiting corrosion. Simultaneously, sodium silicate further covers the active sites of the metal corrosion reaction, forming a denser protective layer, thus synergistically improving the coating's corrosion resistance.

[0267] The high-temperature resistance and long-term corrosion resistance of Examples 8-12 and Comparative Examples 3-4 were tested. The method was as follows: coating samples were taken and immersed in hot water at 95°C for 7 days. The surface of the samples was then observed (test standard GB / T 1733-1993) and their electrochemical impedance was measured (test standard GB / T 39482-2020). The results are shown in Table 4.

[0268] Table 4

[0269] For the coatings prepared in the examples and comparative examples, the initial electrochemical impedance was within 10. ^ After being soaked in 95℃ hot water for 7 days, the composite coating containing Zn-MOF, thiourea, and sodium silicate showed significantly better corrosion resistance than pure epoxy coating and Zn-MOF material coating due to the synergistic effect of multiple anti-corrosion components.

[0270] The above is a detailed description of the preferred embodiments of this application. However, this application is not limited to the above embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of this application. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. An anticorrosive coating, wherein, The raw material components of the anticorrosive coating include, by weight parts, 30-44 parts of epoxy resin, 1-10 parts of organic azole modified metal organic framework material.

2. The anticorrosive coating according to claim 1, wherein The raw material components of the anticorrosive coating further include, by weight parts, 1-12 parts of curing agent, 1-28 parts of filler, and 0.1-1 part of auxiliary agent.

3. The anticorrosive coating according to claim 2, wherein The raw material components of the anticorrosive coating include, by weight parts, 40-44 parts of epoxy resin, 5-8 parts of organic azole modified metal organic framework material, 8-10 parts of curing agent, 23-26 parts of filler, and 0.5-0.8 part of auxiliary agent.

4. The anticorrosive coating according to any one of claims 1 to 3, wherein, The epoxy resin is selected from at least one of bisphenol A type epoxy resin, phenolic type epoxy resin, bisphenol F type epoxy resin, and bisphenol S type epoxy resin.

5. The anticorrosive coating according to any one of claims 1 to 4, wherein, The organic azole modified metal organic framework material is selected from at least one of benzotriazole-metal organic framework material, methylbenzotriazole-metal organic framework material, benzothiazole-metal organic framework material, and 2-mercaptobenzothiazole-metal organic framework material.

6. The anticorrosive coating according to any one of claims 2 to 5, wherein, The curing agent is selected from at least one of imidazole, benzidine, diamino diphenyl methane, aromatic amine E, m-phenylenediamine, and polyamide; and / or, The filler is selected from at least one of talc powder, carbon black, white carbon black, titanium dioxide, mica powder, wollastonite powder, ceramic powder, and glass flake; and / or, The auxiliary agent is selected from at least one of defoaming agent, leveling agent, thixotropic agent, coupling agent, anti-settling agent, and dispersant.

7. A preparation method of the anticorrosive coating according to any one of claims 1-6, comprising the steps of: synthesizing Zn-metal organic framework material by hydrothermal method; adding organic azole ligand to the Zn-metal organic framework material for reaction to synthesize organic azole modified metal organic framework material; and mixing the organic azole modified metal organic framework material and epoxy resin uniformly, then melt extruding and sieving to obtain the anticorrosive coating.

8. The method of preparing an anticorrosive coating according to claim 7, wherein, The step of synthesizing Zn-metal organic framework material by hydrothermal method comprises: dissolving zinc nitrate and 2-thiophene carboxylic acid in a mixed solution of water and methanol, then adding sodium hydroxide, and then adding 4,4-bipyridine, mixing uniformly, and then placing in a hydrothermal reactor, and reacting at 100-150°C for 8-16h; after the reaction is completed, the obtained solid is washed and dried to obtain the Zn-metal organic framework material.

9. The method of preparing a corrosion protective coating according to claim 7 or 8, wherein, The step of synthesizing organic azole modified metal organic framework material comprises: dispersing the Zn-metal organic framework material in methanol, adding the organic azole ligand, and reacting at 40-70°C for 8-13h; after the reaction is completed, the obtained solid is washed and dried to obtain the organic azole modified metal organic framework material.

10. The method of preparing an anticorrosive coating according to claim 9, wherein, The organic azole ligand includes at least one of benzotriazole ligand, methylbenzotriazole ligand, 2-mercaptobenzothiazole ligand, benzimidazole ligand, and benzothiazole ligand.

11. The method of preparing an anticorrosive coating according to claim 10, wherein, The organic azole-modified metal-organic framework material comprises at least one of benzotriazole-metal-organic framework material, methylbenzotriazole-metal-organic framework material, 2-mercaptobenzothiazole-metal-organic framework material, benzimidazole-metal-organic framework material, benzothiazole-metal-organic framework material.

12. Use of the anticorrosive coating as claimed in any one of claims 1 to 6 or prepared by the method as claimed in any one of claims 7 to 11 for protecting a metal substrate from corrosion.

13. A corrosion protective coating wherein, The anticorrosive coating as claimed in any one of claims 1 to 6 or prepared by the method as claimed in any one of claims 7 to 11 is uniformly coated on the surface of a metal substrate by electrostatic spraying, and then solidified to obtain the anticorrosive coating.

14. A coated article comprising a metal substrate and the anticorrosive coating as claimed in any one of claims 1 to 6 or prepared by the method as claimed in any one of claims 7 to 11 coated on the metal substrate.

15. The coated article of claim 14, wherein, The metal substrate comprises a metal element, a metal alloy.

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