High-weatherability cofs modified fluorocarbon coating, and preparation method and application thereof

Abstract

The application provides a high-weatherability COFs modified fluorocarbon coating, which comprises 90-140 parts of fluorocarbon resin, 10-50 parts of porous material, 0.5-2 parts of adhesion promoter, 1-2 parts of dispersing agent and 0.5-1 part of defoaming agent; the porous material is a zinc-loaded covalent organic framework material Zn-COFS. A preparation method of the modified fluorocarbon coating is as follows: dimethyl isophthalate, mesitylene, N-methyl pyrrolidone and isoquinoline are mixed, heated and reacted under vacuum, and a covalent organic framework material COFS is collected; a zinc salt is dissolved in a solvent, the covalent organic framework material COFS is added, and a solid is collected after the reaction is completed to obtain the zinc-loaded covalent organic framework material Zn-COFS; the fluorocarbon resin, the Zn-COFS, the adhesion promoter, the dispersing agent and the defoaming agent are mixed and stirred to obtain the COFS modified fluorocarbon coating, which is used for preparing a steel structure anticorrosion coating. The application significantly improves the adhesion, impact resistance and weatherability of the fluorocarbon coating, and overcomes the performance degradation and aging problems of the traditional fluorocarbon coating in long-term application.

Description

Technical Field

[0001] This invention belongs to the field of coating technology, specifically relating to a high weather-resistant COFs-modified fluorocarbon coating, its preparation method, and its application. Background Technology

[0002] In coastal areas, power transmission and transformation equipment, offshore wind power facilities, and other infrastructure extensively utilize galvanized steel, stainless steel, and other metallic materials. These facilities operate under harsh atmospheric conditions characterized by high humidity, high salt spray, and strong ultraviolet radiation, making them highly susceptible to corrosion and damage. Continuous erosion by corrosive media (such as water, oxygen, and chloride ions) can easily lead to corrosion and damage to the metal substrate, severely impacting the service life and operational safety of the facilities. Therefore, it is typically necessary to coat their surfaces with high-performance anti-corrosion coatings to create a physical barrier that isolates or delays contact between corrosive media and the metal substrate.

[0003] However, most existing anti-corrosion coatings still have limitations in practical applications. Especially in high-humidity environments, when water vapor condenses on the coating surface, it often forms a continuously spreading water film. This not only provides a channel for the penetration of corrosive media such as chloride ions and dissolved oxygen, but also allows corrosive media to slowly penetrate to the substrate surface through microscopic defects in the paint film, resulting in a significant decrease in the protective effect of the coating and failing to meet long-term, stringent protection requirements.

[0004] Fluorocarbon coatings, with their unique molecular structure, endow the coatings with excellent weather resistance, chemical corrosion resistance, and pollution resistance, thus finding widespread application in the long-term corrosion protection of steel structures. However, when faced with extremely harsh corrosive environments such as coastal power transmission lines and offshore wind power, the performance of conventional fluorocarbon coatings remains insufficient. Specifically, their salt spray resistance and artificial weathering resistance are gradually failing to meet the requirements of engineering designs for ultra-long service lives, necessitating urgent modification using new technologies to further enhance their comprehensive protective capabilities in extreme environments. Summary of the Invention

[0005] To overcome the problems existing in the prior art, this invention provides a high-weather-resistant COFs-modified fluorocarbon coating and its preparation method. The coating prepared using this high-weather-resistant COFs-modified fluorocarbon coating can effectively prevent the penetration of corrosive media such as water, oxygen, and chloride ions, improving the coating's strength and anti-corrosion performance, thereby extending the coating's service life. This high-weather-resistant COFs-modified fluorocarbon coating is suitable for coating and protecting steel structures in harsh outdoor environments such as power transmission lines and offshore wind power.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] (I) The present invention provides a high weather-resistant COFs modified fluorocarbon coating, comprising the following raw materials in parts by weight: 90-140 parts of fluorocarbon resin, 10-50 parts of porous material, 0.5-2 parts of adhesion promoter, 1-2 parts of dispersant and 0.5-1 parts of defoamer; wherein the porous material is a zinc-loaded covalent organic framework material Zn-COFs.

[0008] Further, the preparation method of the porous material includes the following steps: S1: Dimethyl isophthalate, mesitylene, N-methylpyrrolidone and isoquinoline are mixed and heated under vacuum. After the reaction is completed, the solid is collected to obtain covalent organic framework material (COFs); S2: Zinc salt is dissolved in a solvent, covalent organic framework material (COFs) is added, and the reaction is stirred. After the reaction is completed, the solid is collected to obtain zinc-loaded covalent organic framework material (Zn-COFs).

[0009] Furthermore, the addition ratio of dimethyl isophthalate, mesitylene, N-methylpyrrolidone, isoquinoline, and zinc salt is 10.5~15 g: 50~70 ml: 20~30 ml: 10~15 ml: 2~3 g.

[0010] Furthermore, in step S1, the heating temperature is 65~75 ℃ and the reaction time is 18~22 h.

[0011] Further, in step S1, after the reaction is complete, the collected solid is washed and filtered sequentially with N,N-dimethylformamide, tetrahydrofuran, ethanol and acetone to obtain covalent organic framework materials (COFs).

[0012] Furthermore, in step S2, the stirring reaction is carried out at room temperature for 18-24 hours.

[0013] Furthermore, in step S2, the zinc salt is zinc chloride or zinc sulfate, and the solvent is methanol or ethanol.

[0014] Furthermore, the fluorocarbon resin (FEVE) can be selected from JF-2X, Genero, or QB224 fluorocarbon.

[0015] Furthermore, the adhesion promoter can be selected from Coatosil MP200 or OFS6040. By adding an adhesion promoter, the adhesive strength of the coating can be improved, while also increasing the water resistance and durability of the coating.

[0016] Furthermore, the defoamer may be AC-300, BYK-057, or DF-7010.

[0017] Furthermore, the dispersant can be selected from BYK190, BYK2015, TEGO747W, or TEGO760W. The addition of a dispersant can improve the dispersion stability and leveling properties of the coating.

[0018] (ii) The present invention also provides a method for preparing the above-mentioned high weather resistance COFs modified fluorocarbon coating, specifically: mixing and stirring fluorocarbon resin, porous material, adhesion promoter, dispersant and defoamer to obtain COFs modified fluorocarbon coating.

[0019] Furthermore, the mixing speed is 600-900 rpm, and the mixing time is 15-30 min.

[0020] (iii) The present invention also provides the application of the above-mentioned high weather-resistant COFs modified fluorocarbon coating in the preparation of anti-corrosion coatings for steel structures.

[0021] The COFs material prepared by this invention has a highly ordered porous structure and an adjustable pore size distribution, with a specific surface area of ​​1000~2000 m². 2 / g. By introducing zinc metal nodes into the COFs framework, a Zn-COFs composite material is formed, utilizing Zn 2+ The coordination chemistry of fluorocarbon resins enhances the stability of the material. The CF bond energy of fluorocarbon resins is as high as 485 kJ / mol, far exceeding that of CH bonds (413 kJ / mol), which endows the coating with excellent chemical inertness. Zn-COFs, as functional fillers dispersed in the fluorocarbon resin matrix, can form a three-dimensional network structure, achieving a protective effect through a dual mechanism of physical barrier and chemical passivation.

[0022] The beneficial effects of this invention are: (1) This invention prepares zinc-loaded covalent organic framework material Zn-COFs by introducing covalent organic framework material COFs, which can give full play to the porous barrier effect of COFs. The prepared Zn-COFs have excellent pore structure and good chemical stability. (2) This invention combines zinc-loaded covalent organic framework materials (Zn-COFs) with fluorocarbon resin to construct a Zn-COFs / fluorocarbon resin synergistic system. In this system, the coordination bonds formed between zinc ions and organic molecules significantly enhance the structural stability of the material, effectively delaying the chemical penetration of corrosive media and the aging process of the coating during long-term service. Simultaneously, this mechanism helps improve the interfacial bonding between the coating and the substrate, thereby significantly extending the service life of the coating. Experiments show that this composite material coating exhibits excellent weather resistance under severe corrosive environments, effectively overcoming the technical difficulties of performance degradation and aging failure of traditional fluorocarbon coatings during long-term use, and is particularly suitable for long-term corrosion protection in harsh environments such as coastal and offshore wind power. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Example 1 This embodiment provides a COFs-modified fluorocarbon coating with high weather resistance. The preparation method includes the following steps: Step 1: Preparation of zinc-loaded covalent organic framework materials Zn-COFs 10.5 g of dimethyl isophthalate, 50 ml of mesitylene, 20 ml of N-methylpyrrolidone and 10 ml of isoquinoline were mixed and heated in a vacuum oven at 70 °C for 18 h. After the reaction was completed, the mixture was cooled to room temperature, and the solid was collected by filtration. The collected solid was washed and filtered successively with 100 ml of N,N-dimethylformamide, 100 ml of tetrahydrofuran, 100 ml of ethanol and 100 ml of acetone to obtain covalent organic framework materials (COFs). 2 g of zinc chloride was dissolved in 60 ml of methanol, and the covalent organic framework material (COFs) prepared above was added. The mixture was stirred at room temperature for 18 h. After the reaction was completed, the solid was collected by filtration and dried in a vacuum drying oven at 70 °C for 6 h to obtain zinc-loaded covalent organic framework material Zn-COFs, wherein the zinc loading was 18 wt%.

[0025] Step 2: Preparation of COFs-modified fluorocarbon coatings with high weather resistance Weigh out 90 parts of fluorocarbon resin, 30 parts of porous material (zinc-loaded covalent organic framework material Zn-COFs), 1.5 parts of adhesion promoter (Coatosil MP200), 1.5 parts of dispersant (BYK190), and 0.8 parts of defoamer (AC-300); mix the above materials and disperse them at high speed of 800 rpm for 20 min in a high-speed mixer to obtain a high weather-resistant COFs modified fluorocarbon coating.

[0026] Example 2 This embodiment provides a COFs-modified fluorocarbon coating with high weather resistance. The difference between this embodiment and Example 1 is that the weight proportions of each raw material are different.

[0027] In step two of this embodiment, the weight parts of each raw material are as follows: 110 parts of fluorocarbon resin, 20 parts of zinc-loaded covalent organic framework material Zn-COFs, 1.2 parts of adhesion promoter, 1.2 parts of dispersant, and 0.6 parts of defoamer.

[0028] Example 3 This embodiment provides a COFs-modified fluorocarbon coating with high weather resistance. The difference between this embodiment and Example 1 is that the weight proportions of each raw material are different.

[0029] In step two of this embodiment, the weight parts of each raw material are: 100 parts of fluorocarbon resin, 50 parts of zinc-loaded covalent organic framework material Zn-COFs, 0.5 parts of adhesion promoter, 1 part of dispersant, and 1 part of defoamer.

[0030] Example 4 This embodiment provides a COFs-modified fluorocarbon coating with high weather resistance. The difference between this embodiment and Example 1 is that the weight proportions of each raw material are different.

[0031] In step two of this embodiment, the weight parts of each raw material are as follows: 140 parts of fluorocarbon resin, 10 parts of zinc-loaded covalent organic framework material Zn-COFs, 2 parts of adhesion promoter, 2 parts of dispersant, and 0.5 parts of defoamer.

[0032] Example 5 This embodiment provides a COFs-modified fluorocarbon coating with high weather resistance. The difference between this embodiment and Example 1 is that the addition ratios of dimethyl isophthalate, mesitylene, N-methylpyrrolidone, isoquinoline, and zinc salt are different.

[0033] In step one of this embodiment, the addition ratio of dimethyl isophthalate, mesitylene, N-methylpyrrolidone, isoquinoline, and zinc salt is 12 g: 60 ml: 30 ml: 15 ml: 3 g.

[0034] Example 6 This embodiment provides a COFs-modified fluorocarbon coating with high weather resistance. The difference between this embodiment and Example 1 is that the addition ratios of dimethyl isophthalate, mesitylene, N-methylpyrrolidone, isoquinoline, and zinc salt are different.

[0035] In step one of this embodiment, the addition ratio of dimethyl isophthalate, mesitylene, N-methylpyrrolidone, isoquinoline, and zinc salt is 15 g: 70 ml: 25 ml: 12 ml: 2.5 g.

[0036] Example 7 This embodiment provides a COFs-modified fluorocarbon coating with high weather resistance. The difference between this embodiment and Example 1 is that the reaction temperature and reaction time are different after mixing dimethyl isophthalate, mesitylene, N-methylpyrrolidone and isoquinoline.

[0037] In step one of this embodiment, after mixing dimethyl isophthalate, mesitylene, N-methylpyrrolidone and isoquinoline, the vacuum oven temperature is 75 ℃ and the heating reaction time is 20 h.

[0038] Example 8 This embodiment provides a COFs-modified fluorocarbon coating with high weather resistance. The difference between this embodiment and Example 1 is that the reaction temperature and reaction time are different after mixing dimethyl isophthalate, mesitylene, N-methylpyrrolidone and isoquinoline.

[0039] In step one of this embodiment, after mixing dimethyl isophthalate, mesitylene, N-methylpyrrolidone and isoquinoline, the vacuum oven temperature is 65 ℃ and the heating reaction time is 22 h.

[0040] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that the porous material is not loaded with zinc, and a covalent organic framework material (COFs) modified fluorocarbon coating is used.

[0041] Specifically, the preparation method includes the following steps: Step 1: Preparation of covalent organic framework materials (COFs): 10.5 g of dimethyl isophthalate, 50 ml of mesitylene, 20 ml of N-methylpyrrolidone, and 10 ml of isoquinoline were mixed and heated in a vacuum oven at 70 °C for 18 h. After the reaction was completed, the mixture was cooled to room temperature, and the solid was collected by filtration. The collected solid was washed and filtered successively with 100 ml of N,N-dimethylformamide, 100 ml of tetrahydrofuran, 100 ml of ethanol, and 100 ml of acetone to obtain covalent organic framework materials (COFs).

[0042] Step 2: Preparation of COFs-modified fluorocarbon coatings: Weigh out 90 parts of fluorocarbon resin, 30 parts of the covalent organic framework (COF) material prepared in step one, 1.5 parts of adhesion promoter (Coatosil MP200), 1.5 parts of dispersant (BYK190), and 0.8 parts of defoamer (AC-300). Mix the above materials and disperse them at 800 rpm for 20 min in a high-speed mixer to obtain COF-modified fluorocarbon coating.

[0043] Comparative Example 2 Comparative Example 2 uses fluorocarbon resin as a coating.

[0044] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that the weight parts of each raw material are different.

[0045] In step two, the weight proportions of each raw material are as follows: 85 parts of fluorocarbon resin, 45 parts of zinc-loaded covalent organic framework material Zn-COFs, 1 part of adhesion promoter, 0.8 parts of dispersant, and 0.3 parts of defoamer.

[0046] Comparative Example 4 The difference between Comparative Example 4 and Example 1 is that the weight parts of each raw material are different.

[0047] In step two, the weight proportions of each raw material are as follows: 145 parts of fluorocarbon resin, 55 parts of zinc-loaded covalent organic framework material Zn-COFs, 3 parts of adhesion promoter, 3 parts of dispersant, and 1.5 parts of defoamer.

[0048] Comparative Example 5 The difference between Comparative Example 5 and Example 1 is that the weight parts of each raw material are different.

[0049] In step two, the weight proportions of each raw material are as follows: 90 parts of fluorocarbon resin, 7 parts of zinc-loaded covalent organic framework material Zn-COFs, 0.3 parts of adhesion promoter, 1 part of dispersant, and 0.6 parts of defoamer.

[0050] Comparative Example 6 The difference between Comparative Example 6 and Example 1 is that the addition ratios of dimethyl isophthalate, mesitylene, N-methylpyrrolidone, isoquinoline, and zinc salt are different.

[0051] In step one, the addition ratio of dimethyl isophthalate, mesitylene, N-methylpyrrolidone, isoquinoline, and zinc salt is 9 g: 40 ml: 10 ml: 8 ml: 1 g.

[0052] Comparative Example 7 The difference between Comparative Example 7 and Example 1 is that the addition ratios of dimethyl isophthalate, mesitylene, N-methylpyrrolidone, isoquinoline, and zinc salt are different.

[0053] In step one, the addition ratio of dimethyl isophthalate, mesitylene, N-methylpyrrolidone, isoquinoline, and zinc salt is 18 g: 80 ml: 35 ml: 2 ml: 4 g.

[0054] Comparative Example 8 The difference between Comparative Example 8 and Example 1 is that the addition ratios of dimethyl isophthalate, mesitylene, N-methylpyrrolidone, isoquinoline, and zinc salt are different.

[0055] In step one, the addition ratio of dimethyl isophthalate, mesitylene, N-methylpyrrolidone, isoquinoline, and zinc salt is 14 g: 40 ml: 38 ml: 20 ml: 1.5 g.

[0056] Comparative Example 9 The difference between Comparative Example 9 and Example 1 is that the reaction temperature and reaction time are different after mixing dimethyl isophthalate, mesitylene, N-methylpyrrolidone and isoquinoline.

[0057] In Comparative Example 9, dimethyl isophthalate, mesitylene, N-methylpyrrolidone and isoquinoline were mixed and the vacuum oven temperature was 55 °C, and the heating reaction time was 26 h.

[0058] Comparative Example 10 The difference between Comparative Example 10 and Example 1 is that the reaction temperature and reaction time are different after mixing dimethyl isophthalate, mesitylene, N-methylpyrrolidone and isoquinoline.

[0059] In Comparative Example 10, dimethyl isophthalate, mesitylene, N-methylpyrrolidone and isoquinoline were mixed and the vacuum oven temperature was 80 °C, and the heating reaction time was 15 h.

[0060] Effect test: The coatings of Examples 1-8 and Comparative Examples 1-10 were applied to the surface of steel plates, and the coatings were subjected to performance tests, including salt spray resistance, adhesion, impact resistance and aging resistance.

[0061] Salt spray resistance testing was conducted using the method described in GB / T 1771, recording the duration for which the technical specifications (no blistering, no peeling, no rust) were met. Adhesion testing was conducted using the method described in GB / T 5210. Impact resistance testing was conducted using the method described in GB / T 1732. Artificial accelerated aging testing was conducted using the method described in GB / T 1865, recording the duration for which the technical specifications (no blistering, no cracking, no delamination, and allowable Class I discoloration, Class I loss of gloss, and Class I chalking) were met.

[0062] The test results are shown in Table 1.

[0063] Table 1 - Test results of coating performance in Examples 1-8 and Comparative Examples 1-10

[0064] Referring to Table 1, Comparative Example 1 is compared with Example 1. The difference is that Comparative Example 1 uses pure COFs material without zinc loading. The results show that the coating performance of the pure COFs modified in Comparative Example 1 is significantly inferior to that of the zinc-loaded example in terms of salt spray resistance and anti-aging time. This indicates that the introduction of zinc ions endows the COFs material with stronger coordination activity and electron transfer ability, significantly improving the corrosion resistance and weather resistance limit of the coating. Comparing Comparative Example 2 (pure fluorocarbon coating) with the examples of the present invention, the salt spray resistance and anti-aging time of the pure fluorocarbon coating are much lower than those of the examples, and it even fails to meet the requirements in terms of impact resistance. This directly proves that there is a bottleneck in the performance of fluorocarbon resin alone, while by combining it with functional materials such as Zn-COFs, a synergistic effect can be produced, which greatly makes up for the shortcomings of pure fluorocarbon resin. Comparative Examples 3 to 8 adjusted the amount of each component in the formulation, and their performance failed to reach the level of the examples. This indicates that the amount of Zn-COFs added, the proportion of additives, and the ratio of various chemical reagents used in the synthesis of Zn-COFs, whether too much or too little, will disrupt the balance of the coating system, leading to varying degrees of decline in anti-corrosion or weather resistance.

[0065] Overall, the coatings prepared in the embodiments of this invention exhibit excellent performance in several key properties. Their salt spray resistance and artificial aging resistance remain at very high levels, while their adhesion is strong and their impact resistance is also satisfactory. This demonstrates that the fluorocarbon coatings modified with zinc-loaded covalent organic framework materials (Zn-COFs) of this invention can construct high-performance protective coatings.

[0066] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A COFs-modified fluorocarbon coating with high weather resistance, characterized in that, The raw materials include the following parts by weight: 90-140 parts of fluorocarbon resin, 10-50 parts of porous material, 0.5-2 parts of adhesion promoter, 1-2 parts of dispersant and 0.5-1 part of defoamer; The porous material is a zinc-loaded covalent organic framework material, Zn-COFs.

2. The high weather-resistant COFs-modified fluorocarbon coating according to claim 1, characterized in that, The method for preparing the porous material includes the following steps: S1: Dimethyl isophthalate, mesitylene, N-methylpyrrolidone and isoquinoline are mixed and heated under vacuum. After the reaction is complete, the solid is collected to obtain covalent organic framework materials (COFs). S2: Dissolve zinc salt in solvent, add covalent organic framework material (COFs), stir to react, collect the solid after the reaction is complete, and obtain zinc-loaded covalent organic framework material Zn-COFs.

3. The high weather-resistant COFs-modified fluorocarbon coating according to claim 2, characterized in that, The addition ratio of dimethyl isophthalate, mesitylene, N-methylpyrrolidone, isoquinoline, and zinc salt is 10.5~15g: 50~70 ml: 20~30 ml: 10~15 ml: 2~3 g.

4. The high weather-resistant COFs-modified fluorocarbon coating according to claim 2, characterized in that, In step S1, the heating temperature is 65~75 ℃ and the reaction time is 18~22 h.

5. The high weather-resistant COFs-modified fluorocarbon coating according to claim 2, characterized in that, In step S1, after the reaction is complete, the collected solid is washed and filtered sequentially with N,N-dimethylformamide, tetrahydrofuran, ethanol and acetone to obtain covalent organic framework materials (COFs).

6. The high weather-resistant COFs-modified fluorocarbon coating according to claim 2, characterized in that, In step S2, the stirring reaction is carried out at room temperature for 18-24 hours.

7. The high weather-resistant COFs-modified fluorocarbon coating according to claim 2, characterized in that, In step S2, the zinc salt is zinc chloride or zinc sulfate, and the solvent is methanol or ethanol.

8. The method for preparing the high weather-resistant COFs-modified fluorocarbon coating according to any one of claims 1 to 7, characterized in that, The COFs-modified fluorocarbon coating is obtained by mixing and stirring fluorocarbon resin, porous material, adhesion promoter, dispersant and defoamer.

9. The method for preparing the high weather-resistant COFs-modified fluorocarbon coating according to claim 8, characterized in that, The mixing speed is 600-900 rpm, and the mixing time is 15-30 min.

10. The application of the high weather-resistant COFs modified fluorocarbon coating according to any one of claims 1 to 7 in the preparation of anti-corrosion coatings for steel structures.

Images