Water-based fluorocarbon emulsion resin coating and preparation method thereof

Abstract

The invention relates to the technical field of coatings, and particularly discloses a water-based fluorocarbon emulsion resin coating and a preparation method thereof. The water-based fluorocarbon emulsion resin coating is prepared from the following raw materials in percentage by weight: 40-60 wt% of water-based fluorocarbon resin, 10-30 wt% of a solvent, 10-30 wt% of a solvent and 10-30 wt% of a solvent. 20-30 wt% of a filler; 5-10 wt% of a curing agent; 0.1 to 1 wt% of a neutralizer; 0.1 to 1 wt% of a wetting agent; 0.1 to 1 wt% of a defoaming agent; 0.1 to 1 wt% of a thickening agent; and the balance of water. The water-based fluorocarbon resin is obtained by crosslinking linoleic acid and FEVE fluorocarbon resin; the curing agent is amino resin. The composition can be used for protecting the surfaces of various instruments and equipment, and has the advantages of safety, environmental protection, high hardness, good adhesive force and simple construction operation steps; in addition, the preparation method also has the advantage of simple operation.

Description

Technical Field

[0001] This application relates to the technical field of coatings, and in particular to a waterborne fluorocarbon emulsion resin coating and its preparation method. Background Technology

[0002] Fluorocarbon resin coatings, as functional coatings, have made significant progress in both industrial and civilian applications in recent years. With the development of manufacturing, the demand for surface coating and corrosion protection for various instruments and equipment is increasing. Fluorocarbon resin coatings, thanks to their inherent properties, have been widely used in numerous fields such as kitchen utensils, industrial machinery, pipelines, tanks, and precision instruments. Their unique molecular structure endows them with excellent properties such as heat resistance and corrosion resistance. These properties extend the service life of related products, reduce maintenance costs, and strongly promote the development of related industries.

[0003] In past applications, two main types of technologies have been commonly used for similar surface coating and corrosion protection needs. One type is solvent-based fluorocarbon resin coatings, which use organic solvents to dissolve fluorocarbon resin before application, forming a protective film on the object's surface. The other type is water-based fluorocarbon resin coatings, which use water as a solvent, conforming to environmental protection principles and avoiding the volatilization of organic solvents. However, these two types of coatings each have their own characteristics. While solvent-based fluorocarbon resin coatings offer better coating results, the use of organic solvents inevitably leads to environmental pollution problems. Water-based fluorocarbon resin coatings are mostly two-component coatings, requiring the mixing of the two components during application, making the process complex. Furthermore, some single-component water-based fluorocarbon resin coatings suffer from poor adhesion and hardness.

[0004] Existing technologies have significant drawbacks. Solvent-based fluorocarbon resin coatings contain high levels of VOCs from organic solvents, causing substantial environmental pollution and failing to meet current environmental protection requirements. Meanwhile, existing waterborne fluorocarbon resin coatings, whether due to their complex two-component application process or the insufficient adhesion and hardness of single-component coatings, severely limit their further promotion and application. Summary of the Invention

[0005] To address the aforementioned technical problems, this application provides a waterborne fluorocarbon emulsion resin coating and its preparation method.

[0006] In a first aspect, this application provides a waterborne fluorocarbon emulsion resin coating, wherein the raw materials used, by weight percentage, include the following components: 40-60 wt% waterborne fluorocarbon resin; 20-30 wt% filler; 5-10 wt% curing agent; 0.1-1 wt% neutralizing agent; 0.1-1 wt% wetting agent; 0.1-1 wt% defoamer; 0.1-1 wt% thickener; and the balance being water; wherein the waterborne fluorocarbon resin is obtained by crosslinking linoleic acid and FEVE fluorocarbon resin; and the curing agent is an amino resin.

[0007] By adopting the above technical solution, this application first utilizes the CF bonds in waterborne fluorocarbon resin to effectively block UVB radiation, and its chemical inertness gives it high resistance to various corrosive substances, endowing the coating with excellent anti-corrosion properties. Combined with the synergistic effect of various additives, this ensures good application performance and stability. Testing shows that the waterborne fluorocarbon emulsion resin coating of this application, after curing, forms a coating with a water resistance time of over 96 hours, an acid resistance time of over 48 hours, a pencil hardness of not less than 3H, a solvent wiping resistance of not less than 200 cycles, and a boiling water adhesion grade ≤0.

[0008] Specifically, the waterborne fluorocarbon resin obtained by crosslinking linoleic acid and FEVE fluorocarbon resin contains linoleic acid structural units, has a large number of ester groups, and contains conjugated double bonds, which can effectively improve the degree of crosslinking inside the coating and effectively improve the strength and adhesion of the coating. At the same time, the present application selects an amino resin curing agent to undergo an ether exchange reaction with the hydroxyl groups in the waterborne fluorocarbon resin to form a crosslinked network structure, which improves the acid resistance, hardness and adhesion of the coating.

[0009] In the specific embodiments of this application, the amino resin is melamine-formaldehyde resin, the wetting agent is a perfluorooctyl sulfonyl fluoride derivative wetting agent, the defoamer is polydimethylsiloxane, and the thickener is hydrophobically modified hydroxyethyl cellulose. These are merely illustrative examples, and those skilled in the art can make reasonable adjustments and substitutions according to the actual situation. They should not be used to limit the scope of protection of this application.

[0010] Preferably, when preparing the waterborne fluorocarbon resin, the weight ratio of linoleic acid to FEVE fluorocarbon resin is controlled to be 9:(2-3).

[0011] By adopting the above technical solution, this application controls the weight ratio of linoleic acid and FEVE fluorocarbon resin during the preparation of waterborne fluorocarbon resin, enabling the two to exert a good synergistic effect. If the amount of linoleic acid is too large, it may damage the original unique chemical structure and physical properties of the fluorocarbon resin, affecting its CF bond resistance to various external substances, thereby reducing the coating's water resistance, acid resistance, and solvent wiping resistance. If the amount of linoleic acid is too small, the cross-linking effect with FEVE fluorocarbon resin cannot be fully achieved, and the overall performance of the coating cannot be improved well. However, at this preferred ratio, the above problems can be avoided, giving the waterborne fluorocarbon emulsion resin coating superior performance.

[0012] Preferably, when preparing the waterborne fluorocarbon resin, the weight ratio of linoleic acid to FEVE fluorocarbon resin is controlled to be 9:2.5.

[0013] By adopting the above technical solution, this application strictly controls the weight ratio of linoleic acid and FEVE fluorocarbon resin to be 9:2.5. At this ratio, the waterborne fluorocarbon emulsion resin coating has the best performance and achieves the best balance of water resistance, acid resistance, solvent wiping resistance, hardness and adhesion.

[0014] Preferably, trimellitic anhydride is added when preparing the aqueous fluorocarbon resin, and the amount of trimellitic anhydride added is controlled to be 8-10 wt% of the total amount of linoleic acid and FEVE fluorocarbon resin.

[0015] By adopting the above technical solution, trimellitic anhydride, as a rigid hydrophilic segment, can react with FEVE fluorocarbon resin to generate ester and carboxyl groups after being added to the system. Simultaneously, it can provide excess carboxyl groups to neutralize and form salts, increasing the hardness of the system and enhancing the hydrophilicity of the waterborne fluorocarbon resin, thereby improving the overall uniformity of the coating and the hardness of the film after formation. This application controls the addition amount of trimellitic anhydride to 8-10 wt% of the total amount of linoleic acid and FEVE fluorocarbon resin. If the addition amount is too large, the water resistance of the coating will decrease significantly; if the addition amount is too small, it will not effectively improve the hardness and uniformity.

[0016] Preferably, the amount of trimellitic anhydride added is 9 wt% of the total amount of linoleic acid and FEVE fluorocarbon resin.

[0017] By adopting the above technical solution, this application strictly controls the addition amount of trimellitic anhydride to 9wt% of the total amount of linoleic acid and FEVE fluorocarbon resin. At this point, the overall uniformity of the coating, the hardness after film formation, and the water resistance of the coating are optimal.

[0018] Preferably, the filler comprises silica and titanium dioxide in a weight ratio of (3-5):(15-25).

[0019] Preferably, the silicon dioxide is aminated silicon dioxide.

[0020] Preferably, the titanium dioxide is alumina-coated titanium dioxide.

[0021] By adopting the above technical solution, this application utilizes a certain weight ratio of silica and titanium dioxide as fillers. The excellent hiding power of titanium dioxide can save 20% of pigment usage, while silica can improve the density and hardness of the paint film, giving the coating better performance. Furthermore, the silica used in this application is aminated silica, which has a surface energy similar to amino resins, enabling high compatibility within the system. The titanium dioxide is alumina-coated titanium dioxide, possessing abundant surface hydroxyl groups and high surface wettability, with extremely low particle aggregation.

[0022] Preferably, the neutralizing agent is N,N-dimethylethanolamine.

[0023] Secondly, this application provides a method for preparing a waterborne fluorocarbon emulsion resin coating, comprising the following steps: mixing waterborne fluorocarbon resin, a neutralizing agent, and 50 wt% water, stirring at 500-800 r / min for 20-30 min, adding a wetting agent and a defoamer, stirring at 1000-1200 r / min for 10-15 min, adding a filler, and stirring at 1500-2000 r / min for 20-30 min, subsequently adding a curing agent and stirring at 1000-1200 r / min for 20-25 min, and finally adding a thickener and the remaining 50 wt% water, and stirring at 500-800 r / min for 10-12 min to obtain the waterborne fluorocarbon emulsion resin coating.

[0024] By adopting the above technical solution, this application first stirs the waterborne fluorocarbon resin, neutralizer, and some water at low speed to facilitate the initial uniform mixing of materials; after adding wetting agent and defoamer, it stirs at medium speed to ensure wetting and defoaming effects; after adding filler, it stirs at high speed to fully disperse the filler; after adding curing agent, it stirs at medium speed to promote cross-linking reaction; finally, it adds thickener and remaining water and stirs at low speed to adjust the viscosity of the coating, thereby obtaining a waterborne fluorocarbon emulsion resin coating with good performance. Because the coating contains titanium dioxide and silica as fillers, it can save pigment usage and improve the hardness of the paint film. The amino resin curing agent can improve the chemical resistance, mechanical properties, and thermal properties of the coating.

[0025] In summary, this application has the following beneficial technical effects: 1. The waterborne fluorocarbon resin obtained by crosslinking linoleic acid and FEVE fluorocarbon resin in this application contains linoleic acid structural units, has a large number of ester groups, and contains conjugated double bonds, which can effectively improve the degree of crosslinking inside the coating and effectively improve the strength and adhesion of the coating. At the same time, this application selects an amino resin curing agent to undergo an ether exchange reaction with the hydroxyl groups in the waterborne fluorocarbon resin to form a crosslinked network structure, which improves the acid resistance, hardness and adhesion of the coating. 2. The waterborne fluorocarbon emulsion resin coating of this application, after curing, forms a coating with a water resistance time of over 96 hours, an acid resistance time of over 48 hours, a pencil hardness of not less than 3H, a solvent wiping resistance of not less than 200 times, and a boiling water adhesion grade ≤ 0. 3. In the preparation method of this application, the waterborne fluorocarbon resin, neutralizer, and a portion of water are first stirred at low speed to facilitate initial uniform mixing of the materials; after adding wetting agent and defoamer, the mixture is stirred at medium speed to ensure wetting and defoaming effects; after adding filler, the mixture is stirred at high speed to fully disperse the filler; after adding curing agent, the mixture is stirred at medium speed to promote cross-linking reaction; finally, thickener and remaining water are added and stirred at low speed to adjust the coating viscosity, thereby obtaining a waterborne fluorocarbon emulsion resin coating with good performance. Because this coating contains titanium dioxide and silica as fillers, it can save pigment usage and improve film hardness. The amino resin curing agent can enhance the coating's chemical resistance, mechanical properties, and thermal properties. Detailed Implementation

[0026] Material source Unless otherwise specified, all raw materials used in this application are commercially available products, specifically: Linoleic acid was purchased from Jining Fangyu Chemical Co., Ltd., industrial grade. The perfluorooctyl sulfonyl fluoride derivative wetting agent was purchased from Shanghai Ziyi Chemical Co., Ltd., with the brand name FC327. Polydimethylsiloxane and hydrophobically modified hydroxyethyl cellulose were purchased from Shanghai Kaiyin Chemical Co., Ltd. Melamine-formaldehyde resin was purchased from Shandong Fite Chemical Technology Co., Ltd. The silica was purchased from Shouguang Changtai New Materials Co., Ltd., 100 mesh. Titanium dioxide was purchased from Hebei Weicai Pigment Co., Ltd., 100 mesh. FEVE fluorocarbon resin was purchased from Dongguan Caihua Plastics Technology Co., Ltd., and its brand name is HLR-2.

[0027] The present application will be further described in detail below with reference to embodiments and comparative examples.

[0028] Preparation Example 1.1 A method for preparing waterborne fluorocarbon resin includes the following steps: 900g of linoleic acid and 200g of FEVE fluorocarbon resin were blended together, and 50g of polypentane glycol, 260g of phthalic anhydride, 400g of crosslinking agent (9:1 ratio of trimethylolpropane and pentaerythritol), 50g of adipic acid and 2.6g of catalyst dibutyltin dilaurate were added. Xylene was used as the reflux agent. The mixture was stirred and heated under nitrogen protection, and refluxed at 150℃ for 1 hour. The temperature was then raised to 220℃ and the reaction was continued for 4 hours. After the acid value in the system was lower than 3mgKOH / g, the system was vacuum depressurized and reacted for 1 hour. The reflux agent and water in the system were removed, and triethylamine was added to neutralize the system. The pH of the system was adjusted to neutral to obtain waterborne fluorocarbon resin.

[0029] Preparation Example 1.2 A method for preparing waterborne fluorocarbon resin includes the following steps: 825g of linoleic acid and 275g of FEVE fluorocarbon resin were blended together, and 50g of polypentane glycol, 260g of phthalic anhydride, 400g of crosslinking agent (9:1 ratio of trimethylolpropane and pentaerythritol), 50g of adipic acid and 2.6g of catalyst dibutyltin dilaurate were added. Xylene was used as the reflux agent. The mixture was stirred and heated under nitrogen protection, and refluxed at 150℃ for 1 hour. The temperature was then raised to 220℃ and the reaction was continued for 4 hours. After the acid value in the system was lower than 3mgKOH / g, the reaction was carried out under vacuum and depressurization for 1 hour. The reflux agent and water in the system were removed, and triethylamine was added to neutralize the mixture. The pH of the system was adjusted to neutral to obtain waterborne fluorocarbon resin.

[0030] Preparation Example 1.3 A method for preparing waterborne fluorocarbon resin includes the following steps: 861g of linoleic acid and 239g of FEVE fluorocarbon resin were blended together, and 50g of polypentane glycol, 260g of phthalic anhydride, 400g of crosslinking agent (9:1 ratio of trimethylolpropane and pentaerythritol), 50g of adipic acid and 2.6g of catalyst dibutyltin dilaurate were added. Xylene was used as the reflux agent. The mixture was then stirred and heated under nitrogen protection, and refluxed at 150℃ for 1 hour. The temperature was then raised to 220℃ and the reaction was continued for 4 hours. After the acid value in the system was lower than 3mgKOH / g, the system was vacuum depressurized and reacted for 1 hour. The reflux agent and water in the system were removed, and triethylamine was added to neutralize the system. The pH of the system was adjusted to neutral to obtain waterborne fluorocarbon resin.

[0031] Preparation Example 2.1 The preparation method of the waterborne fluorocarbon resin differs from that in Preparation Example 1.3 in that trimellitic anhydride is added, specifically: 861g of linoleic acid and 239g of FEVE fluorocarbon resin were blended, and 50g of polypentane glycol, 260g of phthalic anhydride, 400g of crosslinking agent (9:1 ratio of trimethylolpropane and pentaerythritol), 50g of adipic acid, and 2.6g of catalyst dibutyltin dilaurate were added. Xylene was used as the reflux agent. The mixture was stirred and heated under nitrogen protection, and refluxed at 150℃ for 1 hour. The temperature was then raised to 220℃ and the reaction was continued for 4 hours. When the acid value in the system was lower than 3mgKOH / g, the system was vacuum-pressurized and reacted for 1 hour to remove the reflux agent and water. The temperature was then adjusted to 180℃, and 110g of trimellitic anhydride was added. After reacting for 2 hours, the temperature was lowered to 80℃, and triethylamine was added for neutralization. The pH of the system was adjusted to neutral to obtain the waterborne fluorocarbon resin.

[0032] Preparation Example 2.2 The preparation method of the waterborne fluorocarbon resin differs from that in Preparation Example 1.3 in that trimellitic anhydride is added, specifically: 861g of linoleic acid and 239g of FEVE fluorocarbon resin were blended, and 50g of polypentane glycol, 260g of phthalic anhydride, 400g of crosslinking agent (9:1 ratio of trimethylolpropane and pentaerythritol), 50g of adipic acid, and 2.6g of catalyst dibutyltin dilaurate were added. Xylene was used as the reflux agent. The mixture was stirred and heated under nitrogen protection, and refluxed at 150°C for 1 hour. The temperature was then raised to 220°C and the reaction was continued for 4 hours. After the acid value in the system was lower than 3mgKOH / g, the system was vacuum-pressurized and reacted for 1 hour to remove the reflux agent and water. The temperature was then adjusted to 180°C, and 88g of trimellitic anhydride was added. After reacting for 2 hours, the temperature was lowered to 80°C, and triethylamine was added for neutralization. The pH of the system was adjusted to neutral to obtain the waterborne fluorocarbon resin.

[0033] Preparation Example 2.3 The preparation method of the waterborne fluorocarbon resin differs from that in Preparation Example 1.3 in that trimellitic anhydride is added, specifically: 861g of linoleic acid and 239g of FEVE fluorocarbon resin were blended, and 50g of polypentane glycol, 260g of phthalic anhydride, 400g of crosslinking agent (9:1 ratio of trimethylolpropane and pentaerythritol), 50g of adipic acid, and 2.6g of catalyst dibutyltin dilaurate were added. Xylene was used as the reflux agent. The mixture was stirred and heated under nitrogen protection, and refluxed at 150°C for 1 hour. The temperature was then raised to 220°C and the reaction was continued for 4 hours. After the acid value in the system was lower than 3mgKOH / g, the system was vacuum-pressurized and reacted for 1 hour to remove the reflux agent and water. The temperature was then adjusted to 180°C, and 99g of trimellitic anhydride was added. After reacting for 2 hours, the temperature was lowered to 80°C, and triethylamine was added for neutralization. The pH of the system was adjusted to neutral to obtain the waterborne fluorocarbon resin.

[0034] Preparation Example 3 The preparation method of aminated silica includes the following steps: Silica was placed in a forced-air drying oven and dried at 210℃ for 20h. 300g of the dried silica was added to 1.2L of anhydrous ethanol and ultrasonically dispersed at 300W for 2.5h to obtain a dispersion. 7.5g of silane coupling agent KH-550 was dispersed in 40mL of anhydrous ethanol, and then glacial acetic acid was added dropwise to adjust the pH to 3-3.5 to obtain a modified solution. The modified solution was added dropwise to the dispersion at a rate of 1.5mL / min and stirred at 75℃ for 4h. Then it was centrifuged at 8000rpm for 10min, washed with ethanol, and centrifuged again at 8000rpm for 5min. It was then vacuum dried at 65℃ for 4h and then heat-treated at 100℃ for 200h to obtain aminated silica.

[0035] Preparation Example 4 A method for preparing alumina-coated titanium dioxide includes the following steps: Take 150g of TiO2 suspension with a concentration of 270g / L and stir continuously at 350rpm for 10min at 60℃. Add 5.25mL of Zr(SO4)2 solution with a concentration of 100g / L to the TiO2 suspension at a constant feed rate according to the ZrO2:TiO2 ratio of 0.35:100 (mass ratio) over a period of 70min. After the Zr(SO4)2 solution has been added, allow it to mature for 30min. Then adjust the pH of the slurry to 9.5-10.0 with NaAlO2 solution. Subsequently, add Al2O3 and... Under the condition of TiO2 mass ratio of 3:100, 60 mL of 100 g / L NaAlO2 solution was added, followed by 10 wt% H2SO4 for co-current coating. The feeding time was 180 min. During the coating process, the amount of H2SO4 added was adjusted to maintain a constant pH value of the system. After the NaAlO2 solution was fed in, the mixture was allowed to mature for 60 min. After maturation, the pH of the slurry was adjusted to 7.4-7.6 with NaAlO2 solution, and the mixture was allowed to mature for another 60 min. Then, the mixture was filtered and washed with distilled water, dried at 120℃ for 15 h, and then pulverized to obtain alumina-coated titanium dioxide.

[0036] Example 1.1 A method for preparing a waterborne fluorocarbon emulsion resin coating includes the following steps: The aqueous fluorocarbon resin prepared in Example 1.1, a neutralizing agent, and 50 wt% water were mixed and stirred at 800 r / min for 20 min. A wetting agent and a defoamer were added, and the mixture was stirred at 1200 r / min for 10 min. Titanium dioxide filler was added, and the mixture was stirred at 2000 r / min for 20 min. Then, a curing agent was added, and the mixture was stirred at 1200 r / min for 20 min. Finally, a thickener and the remaining 50 wt% water were added, and the mixture was stirred at 800 r / min for 10 min to obtain an aqueous fluorocarbon emulsion resin coating. The specific amounts of each substance are shown in Table 1.

[0037] Example 1.2 A method for preparing a waterborne fluorocarbon emulsion resin coating includes the following steps: The aqueous fluorocarbon resin prepared in Example 1.2, the neutralizing agent, and 50 wt% water were mixed and stirred at 500 r / min for 30 min. Wetting agent and defoamer were added and stirred at 1000 r / min for 15 min. Filler titanium dioxide was added and stirred at 1500 r / min for 30 min. Then, curing agent was added and stirred at 1000 r / min for 25 min. Finally, thickener and the remaining 50 wt% water were added and stirred at 500 r / min for 12 min to obtain an aqueous fluorocarbon emulsion resin coating. The specific amounts of each substance are shown in Table 1.

[0038] Table 1. Substance Usage (g) for Examples 1.1-1.2 Example 1.1 Example 1.2 Waterborne fluorocarbon resin 400 600 Neutralizing agent 10 1 wetting agent 1 10 Defoamer 10 1 filler 300 200 curing agent 100 50 Thickener 1 10 water 178 128 Example 1.3 A method for preparing a waterborne fluorocarbon emulsion resin coating differs from Example 1.1 in that the waterborne fluorocarbon resin obtained in Preparation Example 1.1 is replaced with the waterborne fluorocarbon resin obtained in Preparation Example 1.3, while the rest is the same as in Example 1.1.

[0039] Example 2.1 A method for preparing a waterborne fluorocarbon emulsion resin coating differs from Example 1.3 in that the waterborne fluorocarbon resin obtained in Preparation Example 1.3 is replaced with the waterborne fluorocarbon resin obtained in Preparation Example 2.1, while the rest is the same as in Example 1.3.

[0040] Example 2.2 A method for preparing a waterborne fluorocarbon emulsion resin coating differs from Example 1.3 in that the waterborne fluorocarbon resin obtained in Preparation Example 1.3 is replaced with the waterborne fluorocarbon resin obtained in Preparation Example 2.2, while the rest is the same as in Example 1.3.

[0041] Example 2.3 A method for preparing a waterborne fluorocarbon emulsion resin coating differs from Example 1.3 in that the waterborne fluorocarbon resin obtained in Preparation Example 1.3 is replaced with the waterborne fluorocarbon resin obtained in Preparation Example 2.3, while the rest is the same as in Example 1.3.

[0042] Example 3.1 A method for preparing an aqueous fluorocarbon emulsion resin coating differs from Example 1.1 in that all titanium dioxide is replaced with silicon dioxide, while the rest is the same as in Example 1.1.

[0043] Example 3.2 A method for preparing an aqueous fluorocarbon emulsion resin coating differs from Example 1.1 in that titanium dioxide is replaced with 10g of silicon dioxide and 290g of titanium dioxide, while the rest is the same as in Example 1.1.

[0044] Example 3.3 A method for preparing an aqueous fluorocarbon emulsion resin coating differs from Example 1.1 in that titanium dioxide is replaced with 32g of silicon dioxide and 268g of titanium dioxide, while the rest is the same as in Example 1.1.

[0045] Example 3.4 A method for preparing an aqueous fluorocarbon emulsion resin coating differs from Example 1.1 in that titanium dioxide is replaced with 55g of silicon dioxide and 245g of titanium dioxide, while the rest is the same as in Example 1.1.

[0046] Example 3.5 A method for preparing an aqueous fluorocarbon emulsion resin coating differs from Example 1.1 in that titanium dioxide is replaced with 75g of silicon dioxide and 225g of titanium dioxide, while the rest is the same as in Example 1.1.

[0047] Example 3.6 A method for preparing an aqueous fluorocarbon emulsion resin coating differs from Example 1.1 in that titanium dioxide is replaced with 100g of silicon dioxide and 200g of titanium dioxide, while the rest is the same as in Example 1.1.

[0048] Example 4.1 A method for preparing an aqueous fluorocarbon emulsion resin coating differs from Example 3.4 in that silica is replaced with aminated silica prepared in Preparation Example 3, while the rest is the same as in Example 3.4.

[0049] Example 4.2 A method for preparing an aqueous fluorocarbon emulsion resin coating differs from Example 3.4 in that the titanium dioxide is replaced with the alumina-coated titanium dioxide obtained in Preparation Example 4, while the rest is the same as in Example 3.4.

[0050] Example 4.3 A method for preparing an aqueous fluorocarbon emulsion resin coating differs from Example 3.4 in that: silica is replaced with aminated silica obtained in Preparation Example 3, and titanium dioxide is replaced with alumina-coated titanium dioxide obtained in Preparation Example 4; all other aspects are the same as in Example 3.4.

[0051] Comparative Example 1 The difference from Example 1.1 is that the waterborne fluorocarbon resin prepared in Example 1.1 is replaced with a commercially available ordinary waterborne fluorocarbon resin, while the rest is the same as in Example 1.1.

[0052] Performance testing The waterborne fluorocarbon emulsion resin coatings obtained in the examples and comparative examples were applied to the surface of tinplate and cured. After curing, the coating thickness was 20±3μm. The water resistance time, acid resistance time, pencil hardness, solvent wiping number and boiling water adhesion level of the coating were measured.

[0053] Table 2 Data Record Table Group Water resistance time / h Acid resistance time / h Pencil hardness Solvent-resistant wiping cycles Boiling water adhesion rating Example 1.1 96 48 3H 200 ≤0 Example 1.2 104 52 4H 215 ≤0 Example 1.3 100 52 4H 210 ≤0 Example 2.1 96 56 4H 220 ≤0 Example 2.2 100 50 4H 215 ≤0 Example 2.3 98 54 4H 215 ≤0 Example 3.1 90 44 4H 190 1 Example 3.2 92 48 3H 205 ≤0 Example 3.3 96 56 4H 225 ≤0 Example 3.4 98 54 4H 225 ≤0 Example 3.5 96 54 4H 220 ≤0 Example 3.6 94 52 4H 200 ≤0 Example 4.1 108 58 4H 240 ≤0 Example 4.2 100 56 4H 230 ≤0 Example 4.3 110 60 4H 255 ≤0 Comparative Example 1 92 40 H 165 2 Data Analysis: As shown in Table 2, the waterborne fluorocarbon resin emulsion resin coatings of Examples 1.1-1.3, after curing, exhibit a water resistance time of over 96 hours, an acid resistance time of over 48 hours, a pencil hardness of not less than 3H, a solvent wiping resistance of not less than 200 times, and a boiling water adhesion grade ≤ 0. This demonstrates that the waterborne fluorocarbon resin obtained by crosslinking linoleic acid and FEVE fluorocarbon resin in this application contains linoleic acid structural units, possesses a large number of ester groups, and contains conjugated double bonds, which can effectively enhance the degree of crosslinking within the coating and effectively improve the strength and adhesion of the coating. Simultaneously, this application selects an amino resin curing agent to undergo an ether exchange reaction with the hydroxyl groups in the waterborne fluorocarbon resin to form a crosslinked network structure, thereby improving the acid resistance, hardness, and adhesion of the coating.

[0054] The difference between Examples 2.1-2.3 and Example 1.3 is that, in the preparation of the waterborne fluorocarbon resin, trimellitic anhydride was also added. The results showed that the water resistance time, acid resistance time and solvent wiping number of the coating were significantly improved. This proves that after adding trimellitic anhydride to the system, it can react with FEVE fluorocarbon resin to generate ester groups and carboxyl groups. At the same time, it can also provide excess carboxyl groups to neutralize and form salts, improve the hardness of the system, enhance the hydrophilicity of the waterborne fluorocarbon resin, and thus improve the overall uniformity of the coating and the hardness of the film after formation.

[0055] The difference between Examples 3.1-3.6 is that the composition and ratio of the filler have been changed in this application. The results show that the various indicators of Examples 3.3-3.5 are better, which proves that this application uses a certain weight ratio of silica and titanium dioxide as fillers. The excellent hiding power of titanium dioxide can save 20% of the amount of pigment used, and silica can improve the density and hardness of the paint film, so that the coating has better performance.

[0056] The coatings of Examples 4.1-4.3 exhibit superior overall performance compared to Example 3.4, demonstrating that the aminated silica of this application possesses surface energy similar to that of amino resins, enabling high compatibility within the system. The alumina-coated titanium dioxide has abundant surface hydroxyl groups and high surface wettability, with extremely low agglomeration between particles.

[0057] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A water-based fluorocarbon emulsion resin coating, characterized in that, The raw materials used, by weight percentage, include the following components: Waterborne fluorocarbon resin 40-60wt%; filler 20-30wt%; curing agent 5-10wt%; neutralizing agent 0.1-1wt%; wetting agent 0.1-1wt%; defoamer 0.1-1wt%; thickener 0.1-1wt%; balance: water; The aqueous fluorocarbon resin is obtained by crosslinking linoleic acid and FEVE fluorocarbon resin; The curing agent is an amino resin.

2. The waterborne fluorocarbon emulsion resin coating according to claim 1, characterized in that, When preparing the aqueous fluorocarbon resin, the weight ratio of linoleic acid to FEVE fluorocarbon resin is controlled to be 9:(2-3).

3. The waterborne fluorocarbon emulsion resin coating according to claim 2, characterized in that, When preparing the aqueous fluorocarbon resin, the weight ratio of linoleic acid and FEVE fluorocarbon resin is controlled to be 9:2.

5.

4. The waterborne fluorocarbon emulsion resin coating according to claim 2, characterized in that, When preparing the aqueous fluorocarbon resin, trimellitic anhydride is also added, and the amount of trimellitic anhydride added is controlled to be 8-10 wt% of the total amount of linoleic acid and FEVE fluorocarbon resin.

5. The waterborne fluorocarbon emulsion resin coating according to claim 2, characterized in that, The amount of trimellitic anhydride added is 9 wt% of the total amount of linoleic acid and FEVE fluorocarbon resin.

6. The waterborne fluorocarbon emulsion resin coating according to claim 1, characterized in that, The filler comprises silica and titanium dioxide in a weight ratio of (3-5):(15-25).

7. The waterborne fluorocarbon emulsion resin coating according to claim 6, characterized in that, The silicon dioxide is aminated silicon dioxide.

8. The waterborne fluorocarbon emulsion resin coating according to claim 6, characterized in that, The titanium dioxide is an alumina-coated titanium dioxide.

9. The waterborne fluorocarbon emulsion resin coating according to claim 1, characterized in that, The neutralizing agent is N,N-dimethylethanolamine.

10. A method for preparing an aqueous fluorocarbon emulsion resin coating according to any one of claims 1-9, characterized in that, Includes the following steps: Aqueous fluorocarbon resin, neutralizing agent, and 50 wt% water are mixed and stirred at 500-800 r / min for 20-30 min. Wetting agent and defoamer are added and stirred at 1000-1200 r / min for 10-15 min. Filler is added and stirred at 1500-2000 r / min for 20-30 min. Curing agent is then added and stirred at 1000-1200 r / min for 20-25 min. Finally, thickener and the remaining 50 wt% water are added and stirred at 500-800 r / min for 10-12 min to obtain an aqueous fluorocarbon emulsion resin coating.