Coating and preparation method therefor and use thereof, and coated product

Abstract

Disclosed in the present application are a coating and a preparation method therefor and the use thereof, and a coated product. The raw material components of the coating comprise, in parts by weight, 30-105 parts of an epoxy resin, 1-100 parts of a curing agent composition and 0.3-100 parts of a flaky filler composition. The flaky filler composition comprises a flaky mica powder, glass flakes and flaky andalusite.

Description

A 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. 202411691158.8, filed on November 25, 2024, entitled "A 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 polymer materials technology, and in particular to a coating, its preparation method and application, and coated products. Background Technology

[0004] Epoxy resin is an important thermosetting resin with excellent comprehensive properties, including superior mechanical properties, electrical insulation properties, chemical resistance, and adhesion. This has led to its widespread application in coatings, adhesives, electronic device packaging, aerospace, and microelectronic materials. Coatings using epoxy resin as the main film-forming substance are called epoxy resin coatings. Epoxy resin coatings are one of the most widely used types of protective coatings. The coating they form not only shields against corrosive media but also passivates the protected metal, playing an electrochemical role.

[0005] In related technologies, taking bisphenol A epoxy resin as an example, epoxy resin molten powder based solely on bisphenol A epoxy resin has problems such as poor hygrothermal stability, poor dielectric properties, and low residual mass fraction at high temperatures because its cross-linking network structure contains hydroxyl groups that easily absorb water and has a low cross-linking density. As a result, coatings prepared based on the above-mentioned epoxy resin molten powder are also greatly limited in their application in extremely harsh environments such as high humidity and heat, and acid and alkali corrosion.

[0006] Therefore, providing a coating material that can be used in extremely harsh environments such as high humidity and heat, acid and alkali corrosion, and has good corrosion resistance, high temperature resistance, and strong adhesion has become an urgent problem to be solved. Summary of the Invention

[0007] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a coating, its preparation method and application, and coated articles, aiming to solve the problem that coatings prepared from ordinary epoxy resins are difficult to meet the application requirements in extreme and harsh environments such as high humidity and heat, and acid and alkali corrosion. This application improves the barrier and shielding capabilities of epoxy resin coatings by adding special filler components, thereby modifying the high temperature resistance, water resistance, and corrosion resistance of the epoxy resin coating. Combined with the effect of the curing agent composition, the corrosion resistance, adhesion, and high temperature resistance of the coating are further improved, enabling the coating and coated articles of this application to meet the application requirements in extreme and harsh environments such as high humidity and heat, and acid and alkali corrosion.

[0008] An embodiment of the first aspect of this application provides a coating, wherein the raw material composition of the coating comprises, by weight, 30-105 parts of epoxy resin, 1-100 parts of curing agent composition and 0.3-100 parts of flake filler composition;

[0009] The sheet-like filler composition includes sheet-like mica powder, sheet-like glass flakes, and sheet-like andalusite.

[0010] The coating according to the first aspect of this application has at least the following beneficial effects: The coating provided by this application, by adding flake fillers to modify the coating, can form a layered structure in the coating, thereby improving the barrier and shielding capabilities of the coating; furthermore, this application achieves modification of the epoxy resin coating's high-temperature resistance, water resistance, and corrosion resistance by adjusting the formulation of the flake filler components (flake mica powder, flake glass flakes, and flake andalusite): wherein, the layered structure of the flake mica powder can effectively block the penetration of moisture and gas, enhance the coating's corrosion resistance, improve the coating's water resistance and weather resistance, as well as the coating's mechanical strength, hardness, and impact resistance; the flake glass flakes, by forming a barrier layer, slow down the penetration of chemicals and moisture, block corrosive substances, extend the service life of the coating, and can significantly improve the coating's wear resistance; the flake andalusite can enhance the coating's antioxidant properties, improve the coating's high-temperature resistance, prevent oxidation damage at high temperatures, and improve the coating's wear resistance and scratch resistance, thereby extending the coating's service life. Therefore, by modifying the coating with the above-mentioned epoxy resin composition, this application can achieve the effects of enhancing the water resistance, heat resistance, corrosion resistance, and extending the service life of the epoxy resin coating. Ultimately, by modifying the epoxy resin coating with the above-mentioned flake filler component, this application can significantly improve the coating's corrosion resistance, adhesion, and high-temperature resistance, meeting the application requirements in extremely harsh environments such as high humidity and heat, and acid and alkali corrosion.

[0011] In some embodiments of this application, the raw material components of the coating, by weight, include: 40-90 parts of epoxy resin, 10-40 parts of curing agent composition, and 10-80 parts of flake filler composition.

[0012] This application optimizes the formulation and dosage of the main components in the coating to further improve the curing effect of the curing agent composition on epoxy resin, thereby achieving better effects in reducing the processing temperature of epoxy resin coating, enhancing heat resistance, enhancing impermeability, or enhancing rust prevention.

[0013] In some embodiments of this application, the flake filler composition comprises, by weight, 0.1 to 30 parts of flake mica powder, 0.1 to 30 parts of flake glass flakes, and 0.1 to 50 parts of flake andalusite.

[0014] In some embodiments of this application, the weight ratio of flaky mica powder, flaky glass flakes and flaky andalusite in the flaky filler composition is 1:(1-5):(1-10).

[0015] This application optimizes the proportions of each component in the flake filler composition. When the weight ratio of flake mica powder, flake glass flakes and flake andalusite is within the above range, the corrosion resistance and humid heat stability of the coating prepared by the coating can be further improved.

[0016] In some embodiments of this application, the weight ratio of flaky mica powder, flaky glass flakes, and flaky andalusite in the flaky filler composition is 1:(1-2):(2-5). This includes any numerical value, all ranges, and any subranges thereof. Examples include 1:1:5, 1:2:4, 1:1:3, and 1:2:5. Therefore, within the above ranges, the coatings of this application exhibit excellent mechanical properties, corrosion resistance, and hygrothermal stability.

[0017] In some embodiments of this application, the aspect ratio of the sheet filler composition ranges from 10 to 25:1.

[0018] The aspect ratio is the ratio of the average diameter to the thickness of the sheet filler. This application controls the aspect ratio of the sheet filler composition added to the coating to avoid the sheet filler from agglomerating due to an excessively high aspect ratio, resulting in uneven dispersion in the coating and affecting its improvement of coating performance. On the other hand, if the aspect ratio of the sheet filler is too low, it will be close to that of block filler, making it difficult to achieve the modification of epoxy resin coating in terms of high temperature resistance, water resistance and corrosion resistance.

[0019] In some embodiments of this application, the curing agent composition includes organic amine curing agents, phenolic curing agents, and metal salt curing agents.

[0020] This application modifies the curing agent composition (including organic amine curing agents, phenolic curing agents, and metal salt curing agents) to cure and modify epoxy resin coatings, achieving cured epoxy resin coatings with effects such as low processing temperature, enhanced heat resistance, enhanced impermeability, and enhanced rust prevention. In the curing agent composition of this application, the organic amine curing agents contain NH bonds, which can react with the epoxy groups of the epoxy resin. The primary amine groups react with the epoxy groups to produce secondary amines and hydroxyl groups, improving the heat stability of the crosslinked network. The phenolic hydroxyl groups of the phenolic curing agents react with the epoxy groups to produce ether bonds and hydroxyl groups, where the ether bonds improve the overall flexibility of the epoxy resin coating. The metal salt curing agent, as a co-curing agent, can improve the rust prevention performance of the epoxy coating. By using the above curing agent composition to cure the epoxy resin composition, the corrosion resistance, adhesion, and high-temperature resistance of the coating are significantly improved, thus meeting the application requirements in extremely harsh environments such as high humidity and heat, and acid and alkali corrosion.

[0021] In some embodiments of this application, the organic amine curing agent includes at least one of 4,4'-(1,4-phenyldioxy)bisaniline, 4,4'-bis(4-aminophenoxy)diphenyl sulfone, 4,4'-bis(3-aminophenoxy)diphenyl sulfone, 4,4'-diaminodiphenyl sulfone, and 4,4'-diaminodiphenylmethane.

[0022] The organic amine curing agent used in this application contains NH bonds, which can react with the epoxy groups of epoxy resin. For example, the reaction of primary amines with epoxy groups can produce secondary amines and hydroxyl groups. Epoxy resin coatings cured with organic amine curing agents have high heat resistance, but are also brittle.

[0023] In some embodiments of this application, the phenolic curing agent includes at least one of cashew nut shell powder and phenolic resin.

[0024] The phenolic curing agent used in this application contains phenolic groups. Its phenolic hydroxyl groups can react with epoxy groups to produce ether bonds and hydroxyl groups. Epoxy resin coatings cured with phenolic curing agents have low processing temperature and good flexibility, but insufficient heat resistance.

[0025] In some embodiments of this application, the metal salt curing agent includes dithiophosphoric acid-O,O-di-C 1-14 - Alkyl ester zinc salt.

[0026] The metal salt curing agent used in this application is a zinc-modified organic curing agent, which is used as an auxiliary curing agent to enhance the rust prevention performance of epoxy coatings.

[0027] This application utilizes the combination of the aforementioned curing agents to achieve epoxy resin coatings with low processing temperature, enhanced heat resistance, enhanced impermeability, and enhanced rust prevention. In the curing agent composition of the coating in this application, the organic amine curing agent contains NH bonds, which can react with the epoxy groups of the epoxy resin. The primary amine groups react with the epoxy groups to produce secondary amines and hydroxyl groups, improving the heat resistance stability of the crosslinked network. The phenolic hydroxyl groups of the phenolic curing agent react with the epoxy groups to produce ether bonds and hydroxyl groups, where the ether bonds improve the overall flexibility of the epoxy resin coating. The metal salt curing agent, as a co-curing agent, can improve the rust prevention performance of the epoxy coating. Therefore, this application utilizes a combination of organic amine curing agents, phenolic curing agents, and metal salt curing agents to cure epoxy resin, which can significantly improve the corrosion resistance and high-temperature resistance of the coating, thereby meeting the application requirements in extremely harsh environments such as high humidity and heat, and acid and alkali corrosion.

[0028] In some embodiments of this application, the curing agent composition comprises, by weight: 8-14 parts of organic amine curing agent, 4-10 parts of phenolic curing agent, and 1-19 parts of metal salt curing agent.

[0029] In some embodiments of this application, the epoxy resin is a bisphenol A type epoxy resin, selected from at least one of E51 epoxy resin, E44 epoxy resin, E20 epoxy resin, and E12 epoxy resin.

[0030] A second aspect of this application provides a method for preparing the above-mentioned coating, comprising the following steps:

[0031] The raw material components are mixed according to their weight proportions, heated and cured, and then pulverized to obtain the coating.

[0032] The preparation method provided in this application has the characteristics of simple process, mild reaction conditions, easy operation and high production efficiency, and is suitable for large-scale production application.

[0033] In some embodiments of this application, the heat curing process is as follows: heating to 30–120°C and curing for 10–60 minutes. The heat curing process is a gradient temperature curing process, which includes two stages: heating to 30–100°C and curing for 5–30 minutes, and then heating to 80–120°C and curing for another 5–30 minutes.

[0034] In some embodiments of this application, the pulverization method is to use a grinding mill.

[0035] In some embodiments of this application, the coating is an epoxy resin fusion powder.

[0036] In some embodiments of this application, after obtaining epoxy resin fused powder, it can be directly used as coating powder for electrostatic spraying of metal substrates; or it can be formulated into a slurry and then coated.

[0037] The third aspect of this application provides the application of the above-described coating or the coating prepared by the above-described preparation method in the coating of metal substrates.

[0038] The coating obtained in this application has the characteristics of high heat resistance, easy processing and high adhesion. When applied to metal substrates, the resulting coating has high density, strong impermeability and high heat resistance, which can meet the application requirements in extremely harsh environments.

[0039] The fourth aspect of this application provides an anti-corrosion coating, wherein the raw materials for preparing the anti-corrosion coating include the coatings described above or coatings prepared by the preparation methods described above.

[0040] The anti-corrosion coating provided in this application is obtained by applying the aforementioned paint, and therefore also has the technical effects of the paint described above. This application applies the above-mentioned paint to a metal substrate, resulting in a coating with high density, strong impermeability, and high heat resistance, which can meet the application requirements in extremely harsh environments.

[0041] In some embodiments of this application, the above-mentioned coating can be formulated into a slurry, and then uniformly applied to the surface of a metal substrate by scraping, spinning, or spraying, followed by curing to obtain the anti-corrosion coating. The coating method can be any method conventional in the art and is not limited herein.

[0042] In some embodiments of this application, the thickness of the anti-corrosion coating is 100–500 μm, including any value, all ranges, and any subranges thereof. For example, it includes 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 400 μm, and 500 μm. Therefore, when the thickness of the anti-corrosion coating is within the above range, it has a good protective effect and is not easily peeled off.

[0043] A fifth aspect of this application provides a coated article comprising a metal substrate and a coating on the surface of the metal substrate; the coating is the aforementioned anti-corrosion coating.

[0044] In some embodiments of this application, the metal substrate includes elemental metals and metal alloys, such as tinplate, titanium alloys, and stainless steel.

[0045] The sixth aspect of this application provides a home appliance product, wherein the raw materials for manufacturing the home appliance product include the above-mentioned coatings or the above-mentioned anti-corrosion coatings.

[0046] In some embodiments of this application, the household appliances include refrigeration appliances, air conditioners, cleaning appliances, kitchen appliances, electric heating appliances, audio-visual appliances, and water heaters.

[0047] The seventh aspect of this application provides for the application of the above-mentioned coatings or anti-corrosion coatings in humid or acidic / alkaline environments.

[0048] According to some embodiments of this application, the hot and humid environment refers to an ambient temperature higher than 35°C and an ambient relative humidity higher than 70%.

[0049] 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 and claims. Detailed Implementation

[0050] The following will describe the concept and technical effects of this application clearly and completely with reference to the 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] The first aspect of this application provides a coating, wherein, by weight, the raw material components of the coating include: 30 to 105 parts of epoxy resin, 1 to 100 parts of curing agent composition and 0.3 to 100 parts of flake filler composition;

[0055] The sheet-like filler composition includes sheet-like mica powder, sheet-like glass flakes, and sheet-like andalusite.

[0056] The coatings provided in the embodiments of this application, by adding flake filler components to modify the coating, can form a layered structure in the coating, thereby improving the barrier and shielding capabilities of the coating. Furthermore, the embodiments of this application, through formulation adjustment and component optimization of the flake filler components (flake mica powder, flake glass flakes, and flake andalusite), achieve better modification of the epoxy resin coating's high-temperature resistance, water resistance, and corrosion resistance. Specifically, the layered structure of the flake mica powder can effectively block the penetration of moisture and gas, enhancing the coating's corrosion resistance, improving the coating's water resistance and weather resistance, as well as its mechanical strength, hardness, and impact resistance. The flake glass flakes, by forming a barrier layer, slow down the penetration of chemicals and moisture, block corrosive substances, extend the coating's service life, and significantly improve the coating's abrasion resistance. The flake andalusite can enhance the coating's antioxidant properties, improve its high-temperature resistance, prevent oxidation damage at high temperatures, and improve the coating's abrasion resistance and scratch resistance, extending the coating's service life. Therefore, the embodiments of this application, through the modification of the coating with the above-mentioned epoxy resin composition, can enhance the water resistance, heat resistance, corrosion resistance, and extend the service life of the epoxy resin coating. Ultimately, the embodiments of this application, by utilizing the above-mentioned flake filler component to modify the epoxy resin coating, can significantly improve the coating's corrosion resistance, adhesion, and high-temperature resistance, meeting the application requirements under extremely harsh environments such as high humidity and heat, and acid and alkali corrosion.

[0057] In some embodiments of this application, the raw material components of the coating, by weight, include: 40-90 parts of epoxy resin, 10-40 parts of curing agent composition, and 10-80 parts of flake filler composition.

[0058] In some embodiments of this application, the raw material components of the coating, by weight, include: 50-80 parts of epoxy resin, 16-40 parts of curing agent composition, and 10-80 parts of flake filler composition.

[0059] In some embodiments of this application, the flake filler composition comprises, by weight, 0.1 to 30 parts of flake mica powder, 0.1 to 30 parts of flake glass flakes, and 0.1 to 40 parts of flake andalusite.

[0060] In some embodiments of this application, the flake filler composition comprises, by weight, 1-20 parts of flake mica powder, 1-25 parts of flake glass flakes, and 1-40 parts of flake andalusite.

[0061] In some embodiments of this application, the sheet-like filler composition comprises, by weight, 3-15 parts of sheet-like mica powder, 5-20 parts of sheet-like glass flakes, and 10-35 parts of sheet-like andalusite.

[0062] In some embodiments of this application, the weight ratio of flaky mica powder, flaky glass flakes and flaky andalusite in the flaky filler composition is 1:(1-5):(1-10).

[0063] This application optimizes the proportions of each component in the flake filler composition. When the weight ratio of flake mica powder, flake glass flakes and flake andalusite is within the above range, the corrosion resistance and humid heat stability of the coating prepared by the coating can be further improved.

[0064] In some embodiments of this application, the weight ratio of flaky mica powder, flaky glass flakes, and flaky andalusite in the flaky filler composition is 1:(1-2):(2-5). This includes any numerical value and all ranges and subranges thereof. For example, it includes 1:1:5, 1:2:4, 1:1:3, and 1:2:5. Therefore, within the above ranges, the coatings of the embodiments of this application exhibit excellent mechanical properties, corrosion resistance, and hygrothermal stability.

[0065] In some embodiments of this application, the aspect ratio of the sheet filler composition ranges from 10 to 25:1.

[0066] The aspect ratio is the ratio of the average diameter to the thickness of the sheet filler. In the embodiments of this application, the aspect ratio of the sheet filler composition added to the coating is controlled to avoid the sheet filler from agglomerating due to an excessively high aspect ratio, resulting in uneven dispersion in the coating and affecting its improvement of coating performance. On the other hand, if the aspect ratio of the sheet filler is too low, it is close to that of block filler, making it difficult to achieve the modification of epoxy resin coating in terms of high temperature resistance, water resistance and corrosion resistance.

[0067] In some embodiments of this application, the aspect ratio of the sheet filler composition ranges from 15 to 20:1.

[0068] In some embodiments of this application, the curing agent composition includes organic amine curing agents, phenolic curing agents, and metal salt curing agents.

[0069] The embodiments of this application modify the epoxy resin coating by adjusting the formulation of the curing agent composition (including organic amine curing agents, phenolic curing agents, and metal salt curing agents), thereby achieving the effects of low processing temperature, enhanced heat resistance, enhanced impermeability, and enhanced rust prevention in the cured epoxy resin coating. In the curing agent composition of the coating embodiments of this application, the organic amine curing agent contains NH bonds, which can react with the epoxy groups of the epoxy resin. The primary amine group reacts with the epoxy groups to produce secondary amines and hydroxyl groups, improving the heat resistance stability of the crosslinked network. The phenolic hydroxyl groups of the phenolic curing agent react with the epoxy groups to produce ether bonds and hydroxyl groups, where the ether bonds improve the overall flexibility of the epoxy resin coating. The metal salt curing agent, as a co-curing agent, can improve the rust prevention performance of the epoxy coating. By using the above curing agent composition to cure the epoxy resin composition, the corrosion resistance, adhesion, and high-temperature resistance of the coating are significantly improved, thus meeting the application requirements in extremely harsh environments such as high humidity and heat, and acid and alkali corrosion.

[0070] In some embodiments of this application, the organic amine curing agent includes at least one of 4,4'-(1,4-phenyldioxy)bisphenylamine, 4,4'-bis(4-aminophenoxy)diphenyl sulfone, 4,4'-bis(3-aminophenoxy)diphenyl sulfone, 4,4'-diaminodiphenyl sulfone, and 4,4'-diaminodiphenylmethane.

[0071] In some embodiments of this application, the organic amine curing agent is selected from at least one of 4,4'-(1,4-phenyldioxy)bisaniline, 4,4'-bis(4-aminophenoxy)diphenyl sulfone, 4,4'-bis(3-aminophenoxy)diphenyl sulfone, 4,4'-diaminodiphenyl sulfone, and 4,4'-diaminodiphenylmethane.

[0072] The organic amine curing agents used in the embodiments of this application contain NH bonds, which can react with the epoxy groups of epoxy resins. For example, the reaction of primary amines with epoxy groups can produce secondary amines and hydroxyl groups. Epoxy resin coatings cured with organic amine curing agents have high heat resistance, but are also brittle.

[0073] In some embodiments of this application, the phenolic curing agent includes at least one of cashew nut shell phenol and phenolic resin.

[0074] In some embodiments of this application, the phenolic curing agent is selected from at least one of cashew nut shell phenol and phenolic resin.

[0075] The phenolic curing agent used in the embodiments of this application contains phenolic groups. Its phenolic hydroxyl groups can react with epoxy groups to produce ether bonds and hydroxyl groups. Epoxy resin coatings cured with phenolic curing agents have low processing temperature and good flexibility, but insufficient heat resistance.

[0076] In some embodiments of this application, the metal salt curing agent includes dithiophosphoric acid-O,O-di-C 1-14 - Alkyl ester zinc salt.

[0077] In some embodiments of this application, the metal salt curing agent is dithiophosphate-O,O-di-C 1-14 - Alkyl ester zinc salt.

[0078] The metal salt curing agent used in the embodiments of this application is a zinc-modified organic curing agent, which is used as an auxiliary curing agent to enhance the rust prevention performance of epoxy coatings.

[0079] The embodiments of this application utilize the combination of the above-mentioned curing agents to achieve epoxy resin coatings with low processing temperature, enhanced heat resistance, enhanced impermeability, and enhanced rust prevention. In the curing agent composition of the coatings in the embodiments of this application, the organic amine curing agent contains NH bonds, which can react with the epoxy groups of the epoxy resin. The primary amine group reacts with the epoxy groups to produce secondary amines and hydroxyl groups, improving the heat resistance stability of the crosslinked network. The phenolic hydroxyl groups of the phenolic curing agent react with the epoxy groups to produce ether bonds and hydroxyl groups, where the ether bonds improve the overall flexibility of the epoxy resin coating. The metal salt curing agent, as a co-curing agent, can improve the rust prevention performance of the epoxy coating. Therefore, the embodiments of this application utilize a combination of organic amine curing agents, phenolic curing agents, and metal salt curing agents to cure epoxy resin, which can significantly improve the corrosion resistance and high-temperature resistance of the coating, thereby meeting the application requirements in extremely harsh environments such as high humidity and heat, and acid and alkali corrosion.

[0080] In some embodiments of this application, the curing agent composition comprises, by weight: 8-14 parts of organic amine curing agent, 4-10 parts of phenolic curing agent, and 1-19 parts of metal salt curing agent.

[0081] In some embodiments of this application, the curing agent composition comprises, by weight: 9-13 parts of organic amine curing agent, 4-9 parts of phenolic curing agent, and 2-15 parts of metal salt curing agent.

[0082] In some embodiments of this application, the epoxy resin is a bisphenol A type epoxy resin, selected from at least one of E51 epoxy resin, E44 epoxy resin, E20 epoxy resin, and E12 epoxy resin.

[0083] A second aspect of this application provides a method for preparing the above-mentioned coating, comprising the following steps:

[0084] The raw material components are mixed according to their weight proportions, heated and cured, and then pulverized to obtain the coating.

[0085] The preparation method provided in the embodiments of this application has the characteristics of simple process, mild reaction conditions, easy operation and high production efficiency, and is suitable for large-scale production application.

[0086] In some embodiments of this application, the mixing and the heat curing are carried out in an inert atmosphere or an air atmosphere.

[0087] In some embodiments of this application, the mixing and the heat curing are carried out under an inert atmosphere.

[0088] In some embodiments of this application, the heat curing process is as follows: heating to 30–120°C and curing for 10–60 minutes. The heat curing process is a gradient temperature curing process, which includes two stages: heating to 30–100°C and curing for 5–30 minutes, and then heating to 80–120°C and curing for another 5–30 minutes.

[0089] In some embodiments of this application, the heat curing process is as follows: heating to 30–100°C and curing for 10–60 minutes. The heat curing process is a gradient temperature curing process, which includes two stages: heating to 30–80°C and curing for 5–30 minutes, and then heating to 80–100°C and curing for another 5–30 minutes.

[0090] In some embodiments of this application, the pulverization method is to use a grinding mill.

[0091] In some embodiments of this application, the coating is an epoxy resin fusion powder.

[0092] In some embodiments of this application, after obtaining epoxy resin fused powder, it can be directly used as coating powder for electrostatic spraying of metal substrates; or it can be formulated into a slurry and then coated.

[0093] The third aspect of this application provides the application of the above-described coating or the coating prepared by the above-described preparation method in the coating of metal substrates.

[0094] The coatings obtained from the embodiments of this application have the characteristics of high heat resistance, easy processing, and high adhesion. When applied to metal substrates, the resulting coatings have high density, strong impermeability, and high heat resistance, which can meet the application requirements in extremely harsh environments.

[0095] The fourth aspect of this application provides an anti-corrosion coating, wherein the raw materials for preparing the anti-corrosion coating include the coatings described above or coatings prepared by the preparation methods described above.

[0096] The anti-corrosion coating provided in the embodiments of this application is obtained by applying the aforementioned coating, and therefore also has the technical effects of the coating described above. The embodiments of this application apply the above-mentioned coating to a metal substrate, forming a coating with high density, strong impermeability, and high heat resistance, which can meet the application requirements in extremely harsh environments.

[0097] In some embodiments of this application, the above-mentioned coating can be formulated into a slurry, and then uniformly applied to the surface of a metal substrate by scraping, spinning, or spraying, followed by curing to obtain the anti-corrosion coating. The coating method can be any method conventional in the art and is not limited herein.

[0098] In some embodiments of this application, the thickness of the anti-corrosion coating is 100–500 μm, including any value, all ranges, and any subranges thereof. For example, it includes 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 400 μm, and 500 μm. Therefore, when the thickness of the anti-corrosion coating is within the above range, it has a good protective effect and is not easily peeled off.

[0099] A fifth aspect of this application provides a coated article comprising a metal substrate and a coating on the surface of the metal substrate; the coating is the aforementioned anti-corrosion coating.

[0100] In some embodiments of this application, the metal substrate includes elemental metals and metal alloys, such as tinplate, titanium alloys, and stainless steel.

[0101] The sixth aspect of this application provides a home appliance product, wherein the raw materials for manufacturing the home appliance product include the above-mentioned coatings or the above-mentioned anti-corrosion coatings.

[0102] 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), audio-visual appliances (e.g., mini projectors, televisions, radios, tape recorders, video recorders, cameras, stereo systems, etc.), and water heaters (e.g., air source water heaters, solar water heaters, electric water heaters, gas water heaters, etc.).

[0103] The seventh aspect of this application provides for the application of the above-mentioned coatings or anti-corrosion coatings in humid or acidic / alkaline environments.

[0104] According to some embodiments of this application, the hot and humid environment refers to an ambient temperature higher than 35°C and an ambient relative humidity higher than 70%.

[0105] Furthermore, the sources of some of the raw materials used in the embodiments and comparative examples of this application are as follows:

[0106] Bisphenol A type epoxy resins: E51 epoxy resin, E20 epoxy resin, and E44 epoxy resin were all purchased from Shanghai Huayi Resin Co., Ltd.

[0107] The flake mica powder was purchased from Jiangsu Bosite Chemical Technology Co., Ltd.

[0108] The glass flakes were purchased from Japan Sheet Glass Fiber Products Co., Ltd.

[0109] The flaky andalusite was purchased from Xinjiang Xinrong Yilong Andalusite Co., Ltd.

[0110] Organic amine curing agents: 4,4'-(1,4-phenyldioxy)bisphenylamine, 4,4'-bis(4-aminophenoxy)diphenyl sulfone, and 4,4'-diaminodiphenylmethane were all purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0111] Phenolic curing agents: Cashew nut phenol and phenolic resin were purchased from Beijing Bailingwei Technology Co., Ltd.

[0112] Metal salt curing agent: dithiophosphate -O,O-di-C 1-14 - Alkyl ester zinc salt; CAS No. 68649-42-3; commercially available.

[0113] 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 and claims.

[0114] Example 1

[0115] This embodiment provides a coating material and uses the coating material to prepare a coating layer.

[0116] The raw materials for preparing the coating in this embodiment are, by weight, 75 parts of E51 epoxy resin, 22 parts of curing agent composition, and 40 parts of flake filler composition; wherein, the curing agent composition consists of 10 parts of 4,4'-(1,4-phenyldioxy)bisaniline, 5 parts of cashew nut phenol, and dithiophosphate-O,O-di-C 1-14 The composition of the sheet filler consists of 7 parts alkyl ester zinc salt, 5 parts sheet mica powder, 10 parts sheet glass flakes, and 25 parts sheet andalusite. The aspect ratio of the sheet filler composition is 15–20:1.

[0117] The above-mentioned raw materials by weight were mixed and cured at 80°C for 10 min and 100°C for 10 min under an inert atmosphere. The cured prepolymer resin was then pulverized using an ACM mill to obtain coating powder. The coating powder was formulated into a slurry, sprayed onto a tinplate substrate, and then heat-cured at 230°C in air for 15 min to form the final coating.

[0118] The coating thickness is 250 μm.

[0119] Example 2

[0120] The difference between this embodiment and Example 1 is the coating formulation. In this embodiment, the raw materials, by weight, are: 60 parts E20 epoxy resin, 27 parts curing agent composition, and 45 parts flake filler composition; wherein, the curing agent composition consists of 12 parts 4,4'-bis(4-aminophenoxy)diphenyl sulfone, 8 parts cashew nut shell powder, and dithiophosphate-O,O-di-C 1-14 The alkyl ester zinc salt consists of 7 parts, and the sheet filler composition consists of 10 parts of sheet mica powder, 10 parts of sheet glass flakes, and 25 parts of sheet andalusite. Everything else is the same as in Example 1.

[0121] Example 3

[0122] The difference between this embodiment and Embodiment 1 is the coating formulation. In this embodiment, the raw materials, by weight, are: 65 parts E44 epoxy resin, 25 parts curing agent composition, and 45 parts flake filler composition; wherein, the curing agent composition consists of 10 parts 4,4'-diaminodiphenylmethane, 5 parts phenolic resin, and dithiophosphate-O,O-di-C 1-14 The composition consists of 10 parts of alkyl ester zinc salt, 10 parts of flake mica powder, 10 parts of flake glass flakes, and 25 parts of flake andalusite. Everything else is the same as in Example 1.

[0123] Example 4

[0124] The only difference between this embodiment and Embodiment 1 is that the sheet-like filler composition in this embodiment consists of 5 parts of sheet-like mica powder, 5 parts of sheet-like glass flakes, and 5 parts of sheet-like andalusite. Everything else is the same as in Embodiment 1.

[0125] Example 5

[0126] The only difference between this embodiment and Embodiment 1 is that the sheet-like filler composition in this embodiment consists of 5 parts of sheet-like mica powder, 10 parts of sheet-like glass flakes, and 30 parts of sheet-like andalusite. Everything else is the same as in Embodiment 1.

[0127] Example 6

[0128] The only difference between this embodiment and Example 1 is that the sheet filler composition in this embodiment consists of 5 parts sheet mica powder, 5 parts sheet glass flakes, and 50 parts sheet andalusite. Everything else is the same as in Example 1.

[0129] Comparative Example 1

[0130] The difference between this comparative example and Example 1 is the formulation of the coating. In this comparative example, the raw materials, by weight, are: 75 parts of E44 epoxy resin, 22 parts of curing agent composition, and 40 parts of flake filler composition; wherein, the curing agent composition consists of 10 parts of 4,4'-(1,4-phenyldioxy)bisaniline, 5 parts of cashew nut phenol, and dithiophosphate-O,O-di-C 1-14 The composition consists of 7 parts of alkyl ester zinc salt, 10 parts of flaky glass flakes and 30 parts of flaky andalusite, and does not contain flaky mica powder. Everything else is the same as in Example 1.

[0131] Comparative Example 2

[0132] The difference between this comparative example and Example 1 is the formulation of the coating. In this comparative example, the raw materials, by weight, are: 75 parts E44 epoxy resin, 22 parts curing agent composition, and 35 parts flake filler composition; wherein, the curing agent composition consists of 10 parts 4,4'-(1,4-phenyldioxy)bisaniline, 5 parts cashew nut shell powder, and dithiophosphate-O,O-di-C 1-14 The alkyl ester zinc salt consists of 7 parts, and the flake filler composition consists of 5 parts flake mica powder and 30 parts flake andalusite, without flake glass flakes. Everything else is the same as in Example 1.

[0133] Comparative Example 3

[0134] The difference between this comparative example and Example 1 is the formulation of the coating. In this comparative example, the raw materials, by weight, are: 75 parts E44 epoxy resin, 22 parts curing agent composition, and 35 parts flake filler composition; wherein, the curing agent composition consists of 10 parts 4,4'-(1,4-phenyldioxy)bisaniline, 5 parts cashew nut shell powder, and dithiophosphate-O,O-di-C 1-14 The alkyl ester zinc salt consists of 7 parts, and the flake filler composition consists of 10 parts flake mica powder and 20 parts flake glass flakes, without flake andalusite. Everything else is the same as in Example 1.

[0135] Comparative Example 4

[0136] The difference between this comparative example and Example 1 is the curing method. In this comparative example, the curing method under an inert atmosphere is a gradient temperature increase of 120℃ to 150℃ for 20 minutes. Everything else is the same as in Example 1.

[0137] Comparative Example 5

[0138] The difference between this comparative example and Example 1 is that tinplate (Shandong Gangzhong Steel (Tinplate) Co., Ltd.) was used as the test sample, and its surface was not covered with a protective coating.

[0139] Comparative Example 6

[0140] The difference between this comparative example and Example 1 is that tinplate was used as the test sample, and the surface was sprayed with Dega electrostatic powder coating (item number: RAL1003). After spraying, it was cured at 230°C for 1 hour, and the thickness of the cured coating was 250μm.

[0141] Test case

[0142] 1. Pull-out strength test (GB / T 39289-2020; peel strength after bonding metal and plastic): The pull-out strength of the coatings in Examples 1 and 2 of this application based on stainless steel substrates was tested.

[0143] Pull-out strength test results: In Example 1, the pull-out strength of the coating based on the stainless steel substrate was 3.84 MPa, and in Example 2, the pull-out strength of the coating based on the stainless steel substrate was 5.41 MPa. The test results show that the coating formed by this coating has the characteristics of high density and strong adhesion.

[0144] 2. The corrosion resistance of the coatings in Examples 1-6 and Comparative Examples 1-6 was evaluated by scratch testing. 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 / T10125-2021. The test results are shown in Table 1.

[0145] Table 1. Salt spray test results of the coating samples of the examples and comparative examples after 7 days of cross-cutting.

[0146] The corrosion resistance of the anti-corrosion coating was evaluated through the above cross-cutting test. It was found that the surface coatings in Examples 1-3 showed no significant changes before and after the test, with no corrosion observed except for areas exposed to the outer substrate. Examples 4-6 showed slight blistering of the surface coating, indicating that the weight ratio of the three fillers in the coating needs to be adjusted to achieve the best surface effect. Comparative Examples 1-3 showed partial detachment of the surface coating, indicating that a reasonable combination of flake mica powder, flake glass flakes, and flake andalusite fillers in the epoxy resin coating is needed to achieve better corrosion resistance. Comparative Example 4 showed severe pinholes in the surface coating, indicating that the gradient temperature rise method during curing in the coating preparation process needs precise control; otherwise, a uniform coating cannot be formed. Comparative Example 5 showed severe corrosion at the cross-cutting points with outward corrosion extension, and Comparative Example 6 showed severe coating detachment at the cross-cutting points with severe corrosion extension. These test results indicate that the coating prepared by this application, when applied to a metal substrate, can impart better corrosion resistance.

[0147] 3. Accelerated testing of high-temperature resistance and long-term corrosion resistance was conducted on Examples 1-6 and Comparative Examples 1-6. The method was as follows: Coating samples were taken and immersed in hot water at 170℃ and 0.65MPa for 2 days in a high-temperature autoclave. The surface of the samples was then observed and their electrochemical impedance was measured (test standard GB / T 39482.3-2020). The test results are shown in Table 2.

[0148] Table 2. Accelerated test results of high temperature resistance and long-term corrosion resistance of the coating samples in the examples and comparative examples.

[0149] For the coatings prepared in the examples and comparative examples, the initial electrochemical impedance was 10. 12 After being immersed in hot water at 170°C and 0.65 MPa for 2 days in a high-temperature and high-pressure autoclave, the surface coatings in Examples 1-3 showed no significant changes, and the electrochemical impedance only decreased to 10. 10 Ω; Examples 4-6 show that the electrochemical impedance of the dotted rigid bubble decreases to 10 Ω. 8 Ω. In contrast, the surface coatings of Comparative Examples 1–3 showed dotted blistering, and the electrochemical impedance decreased to 10 Ω. 6 Ω; Comparative Example 4 showed severe blistering of the surface coating, and the electrochemical impedance decreased to 10. 6 Ω; Comparative Example 5 suffered severe surface corrosion because the test sample was not protected by a coating. Comparative Example 6 had a coating with poor high-temperature resistance and corrosion resistance, and the surface coating peeled off, rendering it ineffective in preventing corrosion.

[0150] The above test results show that the coating prepared according to the scheme of this application has good high temperature resistance and long-term corrosion resistance, and can play a good protective role for the substrate. The addition of lamellar filler in the coating of this application can improve the coating structure, effectively block the penetration of moisture and gas, and also improve the high temperature resistance of the coating, thereby improving the corrosion resistance of the coating, preventing damage at high temperatures, and extending the service life. Comparative Examples 1 to 3 lack one of the lamellar fillers used in this application: lamellar mica powder, lamellar glass flakes, and lamellar andalusite, which will affect the high temperature resistance and corrosion resistance of the coating. In Comparative Example 4, the gradient temperature rise during the coating curing process was not precisely controlled, making it difficult to form a uniform coating, which will also affect the protective performance of the coating.

[0151] In summary, this application, through the modification of epoxy resin coatings with the aforementioned flake fillers, can enhance the water resistance, heat resistance, corrosion resistance, and extend the service life of epoxy resin coatings. Ultimately, by utilizing the aforementioned flake filler components to modify epoxy resin coatings, this application can significantly improve the corrosion resistance, adhesion, and high-temperature resistance of the coatings, meeting the application requirements in extremely harsh environments such as high humidity and heat, and acid and alkali corrosion.

[0152] The embodiments of this application have been described in detail above. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application. Furthermore, the embodiments and features in the embodiments of this application can be combined with each other unless otherwise specified.

Claims

1. A coating, wherein, The raw material components of the coating, by weight, include: 30-105 parts epoxy resin, 1-100 parts curing agent composition, and 0.3-100 parts flake filler composition; The sheet-like filler composition includes sheet-like mica powder, sheet-like glass flakes, and sheet-like andalusite.

2. The coating of claim 1, wherein, The raw material components of the coating, by weight, include: 40-90 parts epoxy resin, 10-40 parts curing agent composition, and 10-80 parts flake filler composition.

3. The coating according to claim 1 or 2, wherein, The flake filler composition comprises, by weight, 0.1 to 30 parts of flake mica powder, 0.1 to 30 parts of flake glass flakes, and 0.1 to 50 parts of flake andalusite.

4. The coating according to any one of claims 1 to 3, wherein, The weight ratio of flaky mica powder, flaky glass flakes and flaky andalusite in the flaky filler composition is 1:(1-5):(1-10).

5. The coating according to any one of claims 1 to 4, wherein, The aspect ratio of the sheet-like filler composition is in the range of 10 to 25:

1.

6. The coating according to any one of claims 1 to 5, wherein, The curing agent composition includes organic amine curing agents, phenolic curing agents, and metal salt curing agents.

7. The coating of claim 6, wherein, The organic amine curing agent includes at least one of 4,4'-(1,4-phenyldioxy)bisphenylamine, 4,4'-bis(4-aminophenoxy)diphenyl sulfone, 4,4'-bis(3-aminophenoxy)diphenyl sulfone, 4,4'-diaminodiphenyl sulfone, and 4,4'-diaminodiphenylmethane. And / or, the phenolic curing agent includes at least one of cashew nut shell powder and phenolic resin; and / or the metal salt-based curing agent comprises a di-thiophosphoric acid -O, O-di-C 1-14 - alkyl ester zinc salt.

8. The coating according to any one of claims 1 to 7, wherein, The epoxy resin is a bisphenol A type epoxy resin, selected from at least one of E51 epoxy resin, E44 epoxy resin, E20 epoxy resin, and E12 epoxy resin.

9. A method for preparing a coating as described in any one of claims 1 to 8, comprising the following steps: The raw material components are mixed according to their weight proportions, heated and cured, and then pulverized to obtain the coating.

10. The production method according to claim 9, wherein The heating and curing process is as follows: heat to 30-120℃ and cure for 10-60 minutes.

11. The production method according to claim 10, wherein The heating and curing process is a gradient temperature curing process, which includes two stages: heating to 30-100℃ and curing for 5-30 minutes, and then heating to 80-120℃ and curing for 5-30 minutes.

12. The application of a coating prepared by the preparation method according to any one of claims 9 to 11 in the coating of a metal substrate.

13. A corrosion protective coating wherein, The raw materials for preparing the anti-corrosion coating include coatings prepared by the preparation method according to any one of claims 9 to 11.

14. A coated article comprising a metal substrate and a coating applied to the surface of the metal substrate, wherein the coating is the anti-corrosion coating of claim 13.

15. An electric home appliance, wherein, The raw materials for manufacturing the home appliance products include the coatings as described in any one of claims 1 to 8 or the anti-corrosion coatings as described in claim 13.

16. The household appliance product according to claim 15 includes cleaning appliances, kitchen appliances, electric heating appliances, audio-visual appliances, air conditioners, refrigeration appliances, or water heaters.

17. The application of a coating as described in any one of claims 1 to 8 or an anti-corrosion coating as described in claim 13 in a humid or acidic / alkaline environment.

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