A coating and its preparation method and application, and coated product

Abstract

The present invention discloses a coating and a preparation method and application thereof, and a coated product, belonging to the technical field of polymer materials. The raw material components of the coating provided by the present invention include: an amount of 30 to 100 parts of epoxy resin, an amount of 1 to 100 parts of curing agent, and an amount of 0.3 to 100 parts of a needle-shaped filler composition; the needle-shaped filler composition includes needle-shaped wollastonite, needle-shaped bentonite, and needle-shaped feldspar powder. The present invention improves the epoxy resin with a specific combination of needle-shaped fillers, significantly enhancing the corrosion resistance, high temperature resistance, and wet heat stability of the epoxy resin coating, and can meet the application requirements in extremely harsh environments such as high humidity and heat, acid and alkali corrosion.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and in particular to a coating, a preparation method and application thereof, and a coated product. Background Art

[0002] Epoxy resin is an important thermosetting resin with good comprehensive properties, including excellent mechanical properties, electrical insulation properties, chemical resistance and adhesion, which also makes it widely used in coatings, adhesives, electronic device packaging, aerospace, microelectronic materials and other fields.

[0003] In the related art, taking bisphenol A epoxy resin as an example, since its cross-linked network structure contains hydroxyl groups that are easily absorbent and has a low cross-linking density, the coating prepared from bisphenol A epoxy resin cannot be used in extremely harsh environments such as high humidity and heat and corrosion resistance.

[0004] Therefore, how to provide a coating material with good corrosion resistance, high humidity and heat resistance, and strong adhesion has become an urgent problem to be solved. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the first aspect of the present invention provides a coating, which has the characteristics of strong adhesion, good corrosion resistance, high temperature resistance and good moisture and heat resistance stability.

[0006] A second aspect of the present invention provides a method for preparing a coating.

[0007] A third aspect of the present invention provides an application of a coating.

[0008] A fourth aspect of the present invention provides an anti-corrosion coating.

[0009] A fifth aspect of the present invention provides a coated product.

[0010] A sixth aspect of the present invention provides a household appliance.

[0011] A seventh aspect of the present invention provides an application of a paint or an anti-corrosion coating in a hot and humid environment or an acidic and alkaline environment.

[0012] According to the first aspect of the present invention, an embodiment provides a coating, wherein the raw material components of the coating include, by weight: 30 to 100 parts of epoxy resin, 1 to 100 parts of curing agent, and 0.3 to 100 parts of needle-shaped filler composition;

[0013] The needle-shaped filler composition comprises needle-shaped wollastonite, needle-shaped bentonite and needle-shaped feldspar powder.

[0014] The coating according to the embodiment of the present invention has at least the following beneficial effects:

[0015] The present invention improves the epoxy resin with a specific combination of needle-shaped fillers, which significantly enhances the corrosion resistance, high temperature resistance and wet heat stability of the epoxy resin coating, and can meet the application requirements in extremely harsh environments such as high humidity and heat, acid and alkali corrosion, etc.

[0016] Furthermore, the present invention utilizes the unique morphological structure and physical and chemical properties of the filler, and the needle-shaped filler has a significant enhancement effect on the coating performance of the epoxy resin coating. Needle-shaped wollastonite, needle-shaped bentonite and needle-shaped feldspar powder all present a needle-shaped or fibrous structure, which enables them to form an effective stress dispersion network in the coating. At the same time, these needle-shaped fillers also have good chemical stability and thermal stability, and can maintain the stability of the coating performance under harsh environments.

[0017] As an inorganic filler with high whiteness and hardness, the needle-like structure of wollastonite forms a tight skeleton structure in the coating, effectively improving the tensile strength and wear resistance of the coating. In addition, the high chemical stability of wollastonite enables the coating to maintain good color and gloss even after long-term exposure to outdoor environments. More importantly, the needle-like structure of wollastonite can also form tiny "stress absorbers" in the coating, effectively dispersing the stress concentration of the coating when it is under stress, thereby improving the crack resistance and durability of the coating.

[0018] Needle-shaped bentonite, with its unique needle-shaped structure and high specific surface area, has become a key filler for improving the weather resistance and impermeability of coatings. The needle-shaped structure of bentonite forms a tiny "barrier" in the coating, effectively preventing the penetration of moisture, oxygen and other harmful substances, thereby extending the service life of the coating. At the same time, bentonite also has good ultraviolet absorption capacity, which can significantly reduce the destructive effect of ultraviolet rays on the coating and improve the weather resistance of the coating. In addition, the addition of bentonite also improves the rheology and construction properties of the coating, making the coating smoother and easier to operate during construction.

[0019] Needle-shaped feldspar powder is an ideal filler for enhancing the hardness and wear resistance of coatings due to its high hardness, high wear resistance and good chemical stability. The needle-shaped structure of feldspar powder forms a tight "skeleton" structure in the coating, effectively improving the hardness and scratch resistance of the coating. At the same time, feldspar powder also has good weather resistance and corrosion resistance, and can protect the coating from ultraviolet rays, moisture and chemical erosion. In addition, the addition of feldspar powder also improves the filling and covering power of the coating, allowing the coating to form a more uniform and smooth surface after drying.

[0020] These needle-shaped fillers form a complex stress dispersion network and barrier structure in the coating. At the same time, the addition of these fillers also improves the rheology and construction properties of the coating, making the coating smoother and easier to operate during construction. More importantly, the tight structure formed by these needle-shaped filler compositions in the coating can effectively prevent the formation and expansion of cracks, thereby improving the overall performance and durability of the coating. Finally, the present invention utilizes the above-mentioned needle-shaped filler components to modify the epoxy resin coating, which can significantly improve the corrosion resistance, bonding properties and high temperature resistance of the coating, and can meet the application requirements in extremely harsh environments such as high humidity and heat, acid and alkali corrosion.

[0021] According to some embodiments of the present invention, the raw material components of the coating include: 50 to 80 parts of epoxy resin, 16 to 40 parts of curing agent and 15 to 60 parts of needle-shaped filler composition.

[0022] According to some embodiments of the present invention, the mass ratio of the needle-shaped wollastonite, needle-shaped bentonite and needle-shaped feldspar powder is 1: (1-5): (1-10). Therefore, when the mass ratio of the needle-shaped wollastonite, needle-shaped bentonite and needle-shaped feldspar powder is within the above range, the corrosion resistance and wet heat stability are further improved.

[0023] According to some embodiments of the present invention, the mass ratio of the needle-shaped wollastonite, needle-shaped bentonite and needle-shaped feldspar powder is 1: (1-2): (5-6). Including any numerical value and all ranges and any sub-ranges therein. For example, including 1:1:5, 1:2:5, 1:1:6, 1:2:6. Therefore, within the above range, the coating of the present invention has excellent mechanical properties, corrosion resistance and wet heat stability.

[0024] According to some embodiments of the present invention, the curing agent includes an organic amine curing agent, a phenol curing agent and a metal salt curing agent.

[0025] According to some embodiments of the present invention, in the curing agent, the amount of the organic amine curing agent is 10 to 13 parts, the amount of the phenolic curing agent is 5 to 8 parts, and the amount of the metal salt curing agent is 1 to 19 parts. Therefore, the present invention can improve the curing performance and further enhance the heat resistance, rust resistance and flexibility of the coating through the reasonable combination of the organic amine curing agent, the phenolic curing agent and the metal salt curing agent.

[0026] According to some embodiments of the present invention, the organic amine curing agent is selected from at least one of 4,4'-(1,4-phenylenedioxy) diphenylamine, 4,4'-bis(4-aminophenoxy) diphenyl sulfone, 4,4'-bis(3-aminophenoxy) diphenyl sulfone, 4,4'-diaminodiphenyl sulfone, and 4,4'-diaminodiphenylmethane. Thus, the organic amine curing agent contains NH bonds, which can react with the epoxy groups of the epoxy resin, such as the reaction of primary amines with epoxy groups to produce secondary amines and hydroxyls, and the epoxy resin coating cured with the organic amine curing agent has high heat resistance.

[0027] According to some embodiments of the present invention, the phenolic curing agent is selected from at least one of cardanol and phenolic resin. Thus, the phenolic curing agent contains a phenol group, and its phenolic hydroxyl group reacts with the epoxy group to produce an ether bond and a hydroxyl group. The epoxy resin coating cured by the phenolic curing agent has a low processing temperature and good flexibility.

[0028] According to some embodiments of the present invention, the metal salt curing agent is selected from dithiophosphoric acid-O,O-di-C 1-14 -Alkyl ester zinc salt. Thus, the anti-rust performance of epoxy coating can be enhanced.

[0029] According to some embodiments of the present invention, the epoxy resin includes but is not limited to bisphenol A epoxy resin.

[0030] According to some embodiments of the present invention, the bisphenol A epoxy resin is selected from at least one of E51 epoxy resin, E44 epoxy resin, E20 epoxy resin, and E12 epoxy resin, but is not limited thereto, and may also be selected from common models in the art.

[0031] A second aspect of the present invention provides a method for preparing a coating, comprising the following steps:

[0032] The epoxy resin, curing agent and needle-shaped filler composition are mixed, heated, cured and crushed to obtain the coating.

[0033] The method for preparing the coating according to the embodiment of the present invention has at least the following beneficial effects:

[0034] The preparation method of the invention has simple process, easy operation, high production efficiency and is suitable for large-scale production application.

[0035] According to some embodiments of the present invention, the heating and curing process is: heating to 30-100° C. and curing for 15-60 min.

[0036] According to some embodiments of the present invention, the heating curing process is gradient temperature rise curing, which includes two stages: heating to 30-80° C. for curing for 10-30 min, and then heating to 80-100° C. for curing for 10-30 min.

[0037] According to some embodiments of the present invention, in some embodiments of the present invention, the heating curing process is gradient temperature rise curing, and the gradient temperature rise curing includes two stages: heating to 30-80°C for curing for 10 minutes, and then heating to 80-100°C for curing for 10 minutes.

[0038] According to some embodiments of the present invention, the crushing step is as follows:

[0039] The solidified product was crushed using an ACM mill.

[0040] The third aspect of the present invention provides an application of the coating described in the first aspect of the present invention or the coating prepared by the preparation method described in the second aspect of the present invention in coating a metal substrate.

[0041] The application of the embodiments of the present invention has at least the following beneficial effects:

[0042] The coating obtained by the present invention has the characteristics of high heat resistance, easy processing and high adhesion. When applied to metal substrate coating, the formed coating has high density, strong anti-penetration and high heat resistance, and can meet the application requirements in extremely harsh environments such as high humidity and heat, acid and alkali corrosion, etc.

[0043] The fourth aspect of the present invention provides an anti-corrosion coating, and the raw materials for preparing the anti-corrosion coating include the coating described in the first aspect of the embodiment of the present invention.

[0044] The anti-corrosion coating according to the embodiment of the present invention has at least the following beneficial effects:

[0045] The anticorrosive coating provided by the present invention is obtained by coating the aforementioned coating, and therefore also has the technical effects of the coating described above. The present invention applies the aforementioned coating to a metal substrate, and the formed coating has high density, strong anti-permeability, and high heat resistance, and can meet the application requirements in extremely harsh environments such as high humidity and heat, acid and alkali corrosion, etc.

[0046] According to some embodiments of the present invention, the anti-corrosion coating may be applied by conventional methods in the art, which are not limited here, such as scraping, spin coating or spray coating.

[0047] According to some embodiments of the present invention, the thickness of the anti-corrosion coating is 100-500 μm, including any numerical value and all ranges and any sub-ranges therein, for example, including 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 400 μm and 500 μm.

[0048] The fifth aspect of the present invention provides a coated product, comprising a metal substrate and a coating located on the surface of the metal substrate; the coating is the anti-corrosion coating described in the fourth aspect of the present invention.

[0049] According to some embodiments of the present invention, the metal substrate includes a single metal or a metal alloy, such as tinplate, titanium alloy, stainless steel, etc.

[0050] The sixth aspect of the present invention provides a household appliance product, comprising the coating described in the first aspect of the embodiment of the present invention; or the anti-corrosion coating described in the fourth aspect of the embodiment of the present invention.

[0051] According to some embodiments of the present invention, the household appliances include water heaters (such as air-energy water heaters, solar water heaters, electric water heaters, gas water heaters, etc.), refrigeration appliances (such as household refrigerators, cold drink machines, etc.), air conditioners (such as room air conditioners, electric fans, ventilation fans, hot and cold air blowers, air dehumidifiers, cold air blowers, humidifiers, etc.), cleaning appliances (such as washing machines, dryers, electric irons, vacuum cleaners, floor waxers, sweeping robots, etc.), kitchen appliances (such as electric stoves, microwave ovens, induction cookers, electric ovens, rice cookers, dishwashers, food processors, etc.), electric heating appliances (such as space heaters), audio and video appliances (such as micro projectors, televisions, radios, tape recorders, video recorders, cameras, combination audio systems, etc.).

[0052] A seventh aspect of the present invention provides the use of the above-mentioned coating or the above-mentioned anti-corrosion coating in a hot and humid environment or an acid-base environment.

[0053] According to some embodiments of the present invention, the hot and humid environment refers to an environment temperature higher than 35° C. and an environment relative humidity higher than 70%.

[0054] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the present invention. DETAILED DESCRIPTION

[0055] The following will be combined with the embodiments to clearly and completely describe the concept of the present invention and the technical effects produced, so as to fully understand the purpose, characteristics and effects of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention.

[0056] In the description of the present invention, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0057] In some embodiments of the present invention, a coating is provided, wherein the raw material components of the coating include, by weight: 30 to 100 parts of epoxy resin, 1 to 100 parts of curing agent, and 0.3 to 100 parts of needle-shaped filler composition;

[0058] The needle-shaped filler composition comprises needle-shaped wollastonite, needle-shaped bentonite and needle-shaped feldspar powder.

[0059] It can be understood that the embodiment of the present invention improves the epoxy resin with a specific combination of needle-shaped fillers, which significantly enhances the corrosion resistance, high temperature resistance and wet heat stability of the epoxy resin coating, and can meet the application requirements in extremely harsh environments such as high humidity and heat, acid and alkali corrosion.

[0060] Furthermore, the embodiments of the present invention utilize the unique morphological structure and physical and chemical properties of the filler to significantly enhance the coating performance of the epoxy resin coating. Needle-shaped wollastonite, needle-shaped bentonite, and needle-shaped feldspar powder all present a needle-shaped or fibrous structure, which enables them to form an effective stress dispersion network in the coating, thereby significantly improving the physical strength and toughness of the coating. At the same time, these needle-shaped fillers also have good chemical stability and thermal stability, and can maintain the stability of the coating performance in harsh environments.

[0061] As an inorganic filler with high whiteness and hardness, the needle-like structure of wollastonite forms a tight skeleton structure in the coating, effectively improving the tensile strength and wear resistance of the coating. In addition, the high chemical stability of wollastonite enables the coating to maintain good color and gloss even after long-term exposure to outdoor environments. More importantly, the needle-like structure of wollastonite can also form tiny "stress absorbers" in the coating, effectively dispersing the stress concentration of the coating when it is under stress, thereby improving the crack resistance and durability of the coating.

[0062] Needle-shaped bentonite, with its unique needle-shaped structure and high specific surface area, has become a key filler for improving the weather resistance and impermeability of coatings. The needle-shaped structure of bentonite forms a tiny "barrier" in the coating, effectively preventing the penetration of moisture, oxygen and other harmful substances, thereby extending the service life of the coating. At the same time, bentonite also has good ultraviolet absorption capacity, which can significantly reduce the destructive effect of ultraviolet rays on the coating and improve the weather resistance of the coating. In addition, the addition of bentonite also improves the rheology and construction properties of the coating, making the coating smoother and easier to operate during construction.

[0063] Needle-shaped feldspar powder is an ideal filler for enhancing the hardness and wear resistance of coatings due to its high hardness, high wear resistance and good chemical stability. The needle-shaped structure of feldspar powder forms a tight "skeleton" structure in the coating, effectively improving the hardness and scratch resistance of the coating. At the same time, feldspar powder also has good weather resistance and corrosion resistance, and can protect the coating from ultraviolet rays, moisture and chemical erosion. In addition, the addition of feldspar powder also improves the filling and covering power of the coating, allowing the coating to form a more uniform and smooth surface after drying.

[0064] These needle-shaped fillers form a complex stress dispersion network and barrier structure in the coating, which together improve the physical strength, weather resistance, impermeability, hardness and wear resistance of the coating. At the same time, the addition of these fillers also improves the rheology and construction properties of the coating, making the coating smoother and easier to operate during construction. More importantly, the tight structure formed by these needle-shaped filler compositions in the coating can effectively prevent the formation and expansion of cracks, thereby improving the overall performance and durability of the coating. Finally, the present invention utilizes the above-mentioned needle-shaped filler component to modify the epoxy resin coating, which can significantly improve the corrosion resistance, bonding performance and high temperature resistance of the coating, and can meet the application requirements in extremely harsh environments such as high humidity and heat, acid and alkali corrosion.

[0065] In some embodiments of the present invention, the raw material components of the coating include: 50 to 80 parts of epoxy resin, 16 to 40 parts of curing agent and 30 to 60 parts of needle-shaped filler composition.

[0066] In some embodiments of the present invention, the mass ratio of the needle-shaped wollastonite, needle-shaped bentonite and needle-shaped feldspar powder is 1: (1-5): (1-10). Therefore, when the mass ratio of the needle-shaped wollastonite, needle-shaped bentonite and needle-shaped feldspar powder is within the above range, the effects of corrosion resistance and wet heat stability are further improved.

[0067] In some embodiments of the present invention, the mass ratio of the needle-shaped wollastonite, needle-shaped bentonite and needle-shaped feldspar powder is 1: (1-2): (5-6). Including any numerical value and all ranges and any sub-ranges therein. For example, including 1:1:5, 1:2:5, 1:1:6, 1:2:6. Therefore, within the above range, the coating of the embodiment of the present invention has excellent mechanical properties, corrosion resistance and wet heat stability.

[0068] In some embodiments of the present invention, the curing agent includes an organic amine curing agent, a phenol curing agent and a metal salt curing agent.

[0069] In some embodiments of the present invention, in the curing agent, the amount of the organic amine curing agent is 10 to 13 parts, the amount of the phenolic curing agent is 5 to 8 parts, and the amount of the metal salt curing agent is 1 to 19 parts. Therefore, the present invention can improve the curing performance and further enhance the heat resistance, rust resistance and flexibility of the coating through the reasonable combination of the organic amine curing agent, the phenolic curing agent and the metal salt curing agent.

[0070] In some embodiments of the present invention, the organic amine curing agent is selected from at least one of 4,4'-(1,4-phenylenedioxy) diphenylamine, 4,4'-bis(4-aminophenoxy) diphenyl sulfone, 4,4'-bis(3-aminophenoxy) diphenyl sulfone, 4,4'-diaminodiphenyl sulfone, and 4,4'-diaminodiphenylmethane. Thus, the organic amine curing agent contains NH bonds, which can react with the epoxy groups of the epoxy resin, such as the reaction of primary amines with epoxy groups to produce secondary amines and hydroxyls, and the epoxy resin coating cured with the organic amine curing agent has high heat resistance.

[0071] In some embodiments of the present invention, the phenolic curing agent is selected from at least one of cardanol and phenolic resin. Thus, the phenolic curing agent contains a phenol group, and its phenolic hydroxyl group reacts with the epoxy group to produce an ether bond and a hydroxyl group. The epoxy resin coating cured by the phenolic curing agent has a low processing temperature and good flexibility.

[0072] In some embodiments of the present invention, the metal salt curing agent is selected from dithiophosphoric acid-O,O-di-C 1-14 -Alkyl ester zinc salt. Thus, the anti-rust performance of epoxy coating can be enhanced.

[0073] In some embodiments of the present invention, the epoxy resin includes but is not limited to bisphenol A epoxy resin.

[0074] In some embodiments of the present invention, the bisphenol A epoxy resin is selected from at least one of E51 epoxy resin, E44 epoxy resin, E20 epoxy resin, and E12 epoxy resin, but is not limited thereto, and may also be selected from common types in the art.

[0075] In some embodiments of the present invention, a method for preparing a coating is provided, comprising the following steps:

[0076] The epoxy resin, curing agent and needle-shaped filler composition are mixed, heated, cured and crushed to obtain the coating.

[0077] It can be understood that the preparation method of the present invention has simple process, easy operation, high production efficiency, and is suitable for large-scale production applications.

[0078] In some embodiments of the present invention, the heating and curing process is: heating to 30-100° C. and curing for 15-60 min.

[0079] In some embodiments of the present invention, the heating curing process is gradient temperature rise curing, which includes two stages: heating to 30-80° C. for curing for 10-30 min, and then heating to 80-100° C. for curing for 10-30 min.

[0080] In some embodiments of the present invention, the heating curing process is gradient temperature rise curing, and the gradient temperature rise curing includes two stages: heating to 30-80° C. for curing for 10 min, and then heating to 80-100° C. for curing for 10 min.

[0081] In some embodiments of the present invention, the crushing step is as follows:

[0082] The solidified product was crushed using an ACM mill.

[0083] In some embodiments of the present invention, there is provided a use of the coating described in the first aspect of the present invention or the coating prepared by the preparation method described in the second aspect of the present invention in coating a metal substrate.

[0084] It can be understood that the coating obtained in the embodiment of the present invention has the characteristics of high heat resistance, easy processing and high adhesion. When it is applied to the coating of metal substrates, the formed coating has high density, strong anti-penetration and high heat resistance, and can meet the application requirements in extremely harsh environments such as high humidity and heat, acid and alkali corrosion.

[0085] In some embodiments of the present invention, an anti-corrosion coating is provided, and the raw materials for preparing the anti-corrosion coating include the coating described in the first aspect of the present invention.

[0086] It is understandable that the anti-corrosion coating provided by the present invention is obtained by coating the aforementioned coating, and therefore also has the technical effects of the coating described above. The present invention applies the aforementioned coating to a metal substrate to form a coating with high density, strong anti-permeability and high heat resistance, which can meet the application requirements in extremely harsh environments such as high humidity and heat, acid and alkali corrosion, etc.

[0087] In some embodiments of the present invention, the anti-corrosion coating may be applied by conventional methods in the art, which are not limited here, such as scraping, spin coating or spray coating.

[0088] In some embodiments of the present invention, the thickness of the anti-corrosion coating is 100-500 μm, including any numerical value and all ranges and any sub-ranges therein, for example, including 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 400 μm and 500 μm.

[0089] In some embodiments of the present invention, a coated product is provided, comprising a metal substrate and a coating located on the surface of the metal substrate; the coating is the anti-corrosion coating described in the fourth aspect of the present invention.

[0090] In some embodiments of the present invention, the metal substrate includes a single metal or a metal alloy, such as tinplate, titanium alloy, stainless steel, etc.

[0091] In some embodiments of the present invention, a household appliance product is provided, comprising the coating described in the first aspect of the present invention; or the anti-corrosion coating described in the fourth aspect of the present invention.

[0092] In some embodiments of the present invention, the household appliances include water heaters (such as air-energy water heaters, solar water heaters, electric water heaters, gas water heaters, etc.), refrigeration appliances (such as household refrigerators, cold drink machines, etc.), air conditioners (such as room air conditioners, electric fans, ventilation fans, hot and cold air blowers, air dehumidifiers, cold air blowers, humidifiers, etc.), cleaning appliances (such as washing machines, dryers, electric irons, vacuum cleaners, floor waxers, sweeping robots, etc.), kitchen appliances (such as electric stoves, microwave ovens, induction cookers, electric ovens, rice cookers, dishwashers, food processors, etc.), electric heating appliances (such as space heaters), audio and video appliances (such as micro projectors, televisions, radios, tape recorders, video recorders, cameras, combination audio systems, etc.).

[0093] In some embodiments of the present invention, there is provided application of the above-mentioned coating or the above-mentioned anti-corrosion coating in a hot and humid environment or an acidic and alkaline environment.

[0094] In some embodiments of the present invention, the hot and humid environment refers to an environment temperature higher than 35° C. and a relative humidity higher than 70%.

[0095] Further, some of the raw materials used in the examples and comparative examples of the present invention are as follows:

[0096] Bisphenol A type epoxy resin: E51 epoxy resin, E20 epoxy resin, and E44 epoxy resin were purchased from Shanghai Huayi Resin Co., Ltd.

[0097] Needle-shaped wollastonite: purchased from Jiangxi Kete Fine Powder Co., Ltd.;

[0098] Needle-shaped bentonite: purchased from Weifang Damei Bentonite Co., Ltd.

[0099] Needle-shaped feldspar powder: purchased from Chuzhou Fangda Mining Development Co., Ltd.;

[0100] Organic amine curing agents: 4,4'-(1,4-phenylenedioxy) dianiline, 4,4'-bis(4-aminophenoxy) diphenyl sulfone, and 4,4'-diaminodiphenylmethane were purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0101] Phenolic curing agent: Cardanol and phenolic resin were purchased from Beijing Bailingwei Technology Co., Ltd.

[0102] Metal salt curing agent: dithiophosphoric acid-O,O-di-C 1-14 -Alkyl ester zinc salt, CAS No. 68649-42-3; commercially available.

[0103] Example 1

[0104] This example provides a coating, the amount of each raw material is shown in Table 1, and the preparation method is as follows:

[0105] E51 epoxy resin, curing agent and needle-shaped filler composition 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 crushed using an ACM grinder to obtain a coating.

[0106] Furthermore, an anti-corrosion coating is provided, and the preparation method thereof is as follows:

[0107] The prepared coating was mixed with 30 parts of acetone solvent, 4 parts of BYK9076 dispersant, 0.3 parts of BYK358 leveling agent and 0.05 parts of 6800 defoamer at room temperature to form a slurry, sprayed on tinplate as a metal substrate, and then thermally cured for 15 minutes in an air environment at 230°C to form a final coating. The thickness of the coating was 250 μm.

[0108] Embodiment 2~5

[0109] Examples 2 to 5 provide a series of coatings and anti-corrosion coatings, the raw materials for their preparation are shown in Table 1, and the preparation method is the same as that of Example 1.

[0110] Table 1 Examples 1 to 5 (parts by weight)

[0111]

[0112] Embodiment 6~9

[0113] Examples 6 to 9 provide a series of coatings and anti-corrosion coatings, the raw materials for their preparation are shown in Table 2, and the preparation method is the same as that of Example 1.

[0114] Table 2 Examples 6 to 9 (parts by weight)

[0115]

[0116] Example 10

[0117] This example provides a coating and an anti-corrosion coating, and the raw materials and preparation method thereof are the same as those in Example 1; the difference is that phenolic resin is used instead of cardanol.

[0118] Embodiment 11

[0119] This example provides a coating and an anti-corrosion coating, and the raw materials and preparation method thereof are the same as those in Example 1; the difference is that 4,4'-bis(4-aminophenoxy)diphenyl sulfone is used instead of 4,4'-(1,4-phenylenedioxy)dianiline.

[0120] Comparative Example 1

[0121] This example provides a coating and an anti-corrosion coating, and the raw materials and preparation method thereof are the same as those of Example 1; the difference is that Comparative Example 1 does not contain needle-shaped wollastonite.

[0122] Comparative Example 2

[0123] This example provides a coating and an anti-corrosion coating, and the raw materials and preparation method thereof are the same as those of Example 1; the difference is that Comparative Example 2 does not contain needle-shaped bentonite.

[0124] Comparative Example 3

[0125] This example provides a coating and an anti-corrosion coating, and the raw materials and preparation method thereof are the same as those of Example 1; the difference is that Comparative Example 3 does not contain needle-shaped feldspar powder.

[0126] Comparative Example 4

[0127] This example provides a tinplate (purchased from Shandong Gangzhong Iron and Steel (Tinplate) Co., Ltd.); the surface is not treated.

[0128] Comparative Example 5

[0129] An anti-corrosion coating is provided. Tinplate is used as a test sample. The surface is sprayed with Degao electrostatic powder coating (brand number RAL1003). After spraying, it is cured at 230°C for 1 hour. The cured coating thickness is 250 μm.

[0130] Performance Testing

[0131] Pull-out strength test (GB / T 39289-2020; peel strength after bonding of metal and plastic): The pull-out strength of the coating in Examples 1 and 2 of the present invention based on the stainless steel substrate was tested. The pull-out strength of the coating in Example 1 based on the stainless steel substrate was 6.54 MPa, and the pull-out strength of the coating in Example 2 based on the stainless steel substrate was 5.21 MPa, which proves that the coating formed by the coating has the characteristics of high density and strong adhesion.

[0132] Corrosion resistance: A scratch test was performed on Examples 1 to 11 and Comparative Examples 1 to 5 to evaluate the corrosion resistance of the coating. The method is: take the prepared coating samples, scratch the surface thereof, and the scratch size of the sample surface is consistent. Then, the coating samples are placed in a salt spray test box. After 7 days of salt spray test, the surface of the sample is tested. The test standard is GB / T 10125-2021. The results are shown in Table 3.

[0133] High temperature resistance and long-term corrosion resistance test: Examples 1 to 11 and Comparative Examples 1 to 5 were subjected to accelerated tests of high temperature resistance and long-term corrosion resistance, and the method was as follows: coating samples were taken respectively, and after being immersed in 170 ° C hot water at 0.65 MPa in a high temperature autoclave for 2 days, the surface of the samples was observed and the electrochemical impedance was detected (test standard GB / T 39482-2020). The results are shown in Table 3.

[0134] Table 3

[0135]

[0136] The corrosion resistance of the anti-corrosion coating was evaluated through a scratch test, and it was found that there was no obvious change in the surface coating of the embodiment before and after the experiment. Except for the corrosion of the exposed external substrate, there was no corrosion in other places. The surface coating of comparative examples 1 to 3 partially fell off, indicating that the epoxy resin requires a reasonable ratio of needle-shaped wollastonite, needle-shaped boric acid clay, and needle-shaped feldspar powder; the scratch point of comparative example 4 was severely corroded and the corrosion tended to extend outward, and the coating of comparative example 5 fell off severely at the scratch point, and the scratch point was severely corroded and the corrosion tended to extend outward.

[0137] Furthermore, for the coatings prepared in the examples and comparative examples, except for comparative example 4, the initial electrochemical impedance was 10 ^ 12 Ω, and soaked in 170 ℃ hot water 0.65 MPa in a high temperature autoclave. After 2 days of immersion, the surface coating of the embodiment of the present invention has no obvious change, and the electrochemical impedance only drops to 10 ^ 9~10 ^ 10 Ω, while the surface coatings of Comparative Examples 1 to 3 had point-like bubbles, and the electrochemical impedance dropped to 10 ^6 Ω; the surface of comparative example 4 is seriously corroded, and the surface coating of comparative example 5 falls off and has no anti-corrosion effect. It further illustrates that the coating provided by the present invention has high temperature resistance and good moisture and heat resistance stability.

[0138] The above is a detailed description of the embodiments of the present invention, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A coating, characterized in that: The raw material components of the coating include, by weight: 30 to 100 parts of epoxy resin, 1 to 100 parts of curing agent, and 0.3 to 100 parts of needle-shaped filler composition; The needle-shaped filler composition comprises needle-shaped wollastonite, needle-shaped bentonite and needle-shaped feldspar powder.

2. The coating according to claim 1, characterized in that The raw material components of the coating include, by weight, 50 to 80 parts of epoxy resin, 16 to 40 parts of curing agent and 15 to 60 parts of needle-shaped filler composition.

3. The coating according to claim 1 or 2, characterized in that: The mass ratio of the needle-shaped wollastonite, needle-shaped bentonite and needle-shaped feldspar powder is 1:(1-5):(1-10).

4. The coating according to claim 1 or 2, characterized in that: The curing agent includes organic amine curing agent, phenol curing agent and metal salt curing agent.

5. The coating according to claim 4, characterized in that Among the curing agents, the amount of the organic amine curing agent is 10 parts to 13 parts, the amount of the phenol curing agent is 5 parts to 8 parts, and the amount of the metal salt curing agent is 1 part to 19 parts.

6. The coating according to claim 5, characterized in that The organic amine curing agent is selected from at least one of 4,4'-(1,4-phenylenedioxy) dianiline, 4,4'-bis(4-aminophenoxy) diphenyl sulfone, 4,4'-bis(3-aminophenoxy) diphenyl sulfone, 4,4'-diaminodiphenyl sulfone and 4,4'-diaminodiphenylmethane.

7. The coating according to claim 5, characterized in that The phenolic curing agent is selected from at least one of cardanol and phenolic resin.

8. The coating according to claim 5, characterized in that The metal salt curing agent is selected from dithiophosphoric acid-O,O-di-C1-14-alkyl ester zinc salt.

9. A method for preparing a coating according to any one of claims 1 to 8, characterized in that: The steps include: The epoxy resin, curing agent and needle-shaped filler composition are mixed, heated, cured and crushed to obtain the coating.

10. The preparation method according to claim 9, characterized in that: The heating and curing process is: heating to 30-100°C and curing for 15-60 minutes.

11. The preparation method according to claim 9 or 10, characterized in that: The heating curing process is a gradient temperature rise curing process, which includes two stages: heating to 30-80°C for curing for 10-30 min, and then heating to 80-100°C for curing for 10-30 min.

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

13. An anti-corrosion coating, characterized in that: The raw materials for preparing the anti-corrosion coating include the coating according to any one of claims 1 to 8.

14. A coated product, characterized in that It comprises a metal substrate and a coating located on the surface of the metal substrate; the coating is the anti-corrosion coating according to claim 13.

15. A household appliance, characterized in that: Including the coating according to any one of claims 1 to 8; or the anti-corrosion coating according to claim 13.

16. The household appliance according to claim 15, characterized in that: The household electrical appliances include water heaters, refrigeration appliances, air conditioners, cleaning appliances, kitchen appliances, electric heating appliances or audio-visual appliances.

17. Use of the coating according to any one of claims 1 to 8 or the anti-corrosion coating according to claim 13 in a hot and humid environment or an acid-base environment.

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