Salt fog resistant additive comprising ionic liquid and method of preparation and use thereof

Abstract

The application discloses a kind of salt fog resistant additives comprising ionic liquid and its preparation method and application, belong to chemical material field.In ice water bath condition, neutralization two (2-ethylhexyl) phosphate ester obtains two (2-ethylhexyl) sodium phosphate aqueous solution, then drop to methyltrioctylammonium chloride aqueous solution and react, after oil phase is collected, washing, drying obtains functional ionic liquid;Nitrate type layered double hydroxide is dispersed in solvent, and functional ionic liquid is added, and solid product is collected by centrifugation, and washing obtains intercalation hybrid material;Functional ionic liquid, monoglyceride, 12-hydroxystearic acid, co-surfactant, emulsifier and intercalation hybrid material are mixed to obtain mixed phase, finally drop buffer solution to mixed phase, after cooling, the salt fog resistant additive provided by the application is obtained.The salt fog resistant additive comprising ionic liquid provided by the application is used for nickel-containing hole sealing agent, and the salt fog corrosion resistance of workpiece coating after sealing can be improved, and the ability of anti-point corrosion.

Description

Technical Field

[0001] This invention relates to the field of chemical materials, specifically to a salt spray resistant additive containing ionic liquid, its preparation method, and its application. Background Technology

[0002] Anodized aluminum alloy films are widely used due to their excellent decorative and protective properties, and nickel-containing sealing is a key post-treatment process to improve their corrosion resistance, especially their resistance to salt spray corrosion. This process achieves both physical sealing and chemical passivation by depositing nickel hydroxide in the micropores of the oxide film. With the increasing demands for corrosion resistance and lifespan of aluminum alloy components in high-end equipment, marine engineering, and consumer electronics, the requirements for nickel-containing sealing agents are also becoming increasingly stringent.

[0003] Existing nickel-containing sealing agents and their conventional additive systems have certain shortcomings in achieving long-term protection, hindering further breakthroughs in their performance. Currently widely used corrosion inhibitors (such as molybdates and organic azoles) are mostly added in a physical mixing form, remaining free in the sealing solution and the final film. This leads to two major problems: First, during high-temperature sealing and subsequent use, the sealing agent undergoes processes such as washing and damp heat. In the initial storage or service phase after sealing, traditional additives are prone to migration and seepage to the surface due to concentration gradients, resulting in early loss. Second, when corrosion occurs, the additives cannot target and accumulate at the corrosion initiation point, but are consumed uniformly, resulting in low utilization and difficulty in coping with long-term salt spray corrosion, leading to premature attenuation of the protective life. Furthermore, the interfacial stability between the additives and the coating substrate is insufficient. The relationship between traditional additives and the inorganic / organic composite film formed by sealing is mostly physical, lacking a strong anchoring effect. In harsh environments such as humid heat and salt spray, additive components are prone to migrate and detach from the film layer, which not only causes them to fail but may also leave diffusion channels, accelerate the penetration of the medium, and damage the integrity of the coating. This manifests as a significant decline in salt spray resistance over time.

[0004] Therefore, it is essential to develop a new salt spray resistant additive that can be used in nickel-containing sealing agents. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a salt spray resistant additive containing ionic liquid, its preparation method and application.

[0006] The first aspect of this invention is to provide a method for preparing a salt spray resistant additive comprising an ionic liquid, comprising the following steps: S1: Under ice-water bath conditions, a neutralizing agent was added dropwise to di(2-ethylhexyl) phosphate, and the pH value was adjusted to obtain an aqueous solution of di(2-ethylhexyl) phosphate. S2: Add sodium di(2-ethylhexyl)phosphate aqueous solution dropwise to methyltrioctylammonium chloride aqueous solution to carry out the reaction, collect the oil phase after standing, and obtain the functionalized ionic liquid by washing and drying. S3: Disperse the nitrate-type layered double hydroxide in a solvent, sonicate it, add the functionalized ionic liquid prepared by S2 to react, collect the solid product by centrifugation, and wash it to obtain the intercalated hybrid material. S4: The functionalized ionic liquid, monoglyceride and 12-hydroxystearic acid prepared in S2 are premixed, and then co-surfactant, emulsifier and intercalation hybrid material are added in sequence to obtain a mixed phase; S5: Add a buffer solution to the mixed phase and cool to obtain a salt spray resistant additive containing ionic liquid.

[0007] In this invention, the CAS number of di(2-ethylhexyl) phosphate is 298-07-7, and the CAS number of methyltrioctylammonium chloride is 5137-55-3.

[0008] It should be noted that this invention creatively utilizes the anion exchange properties of LDH (layered double hydroxide) to exchange di(2-ethylhexyl) phosphate anions ([DEHP]). - Intercalation between layers. LDH layers carry a positive charge, and exchangeable anions such as nitrate exist in the interlayer to maintain charge balance; when intercalated with [DEHP]... - When in contact with ionic liquids, due to [DEHP] - With higher charge density and stronger electrostatic interactions with the interlayer, it can displace nitrate ions between layers through ion exchange reactions, while the interlayer spacing of LDH can be expanded to accommodate [DEHP]. - The large-volume hydrophobic structure allows it to be stably and directionally fixed within the interlayer channels.

[0009] In some embodiments, the neutralizing agent is a sodium hydroxide solution, which adjusts the pH to 7-7.5; the aqueous solution of methyltrioctylammonium chloride is prepared by mixing methyltrioctylammonium chloride and deionized water in a mass ratio of 28-32:68-72; and the molar ratio of di(2-ethylhexyl)phosphate to methyltrioctylammonium chloride is 1:1.

[0010] In some embodiments, the solvent is selected from at least one of anhydrous ethanol and isopropanol; the ratio of nitrate-type layered double hydroxide to solvent is 8-12 mg / mL; in S3, the molar ratio of nitrate-type layered double hydroxide to functionalized ionic liquid is 1:1.3-1.7.

[0011] In some embodiments, in S4, the mass ratio of the functionalized ionic liquid, monoglyceride, 12-hydroxystearic acid, co-surfactant, emulsifier and intercalation hybrid material is 6-8:0.8-1.5:0.06-0.13:1.5-2.5:2-4:0.6-1.5.

[0012] In some embodiments, the co-surfactant is 1,2-propanediol; the emulsifier is selected from at least one of Tween-80 and PEG-40 hydrogenated castor oil.

[0013] In some embodiments, the buffer solution is a 0.08-0.12M acetate-sodium acetate buffer solution, and the mass of the buffer solution is 5-7 times the mass of the mixed phase.

[0014] It should be noted that the buffer solution concentration refers to the total concentration of the buffer pair. That is, 0.08-0.12M acetate-sodium acetate buffer means that the sum of the molar concentrations of acetic acid and sodium acetate in the buffer is 0.08-0.12M.

[0015] In some embodiments, in S2, washing is performed 3-5 times with water at 40-50°C, and drying is performed at 65-75°C until the water content of the functionalized ionic liquid is <0.7%; in S3, the reaction is performed by stirring at 55-65°C for 20-24 hours.

[0016] In some embodiments, in S4, premixing is performed by stirring at 70-75°C for 15-20 min, and mixing is performed by stirring at 50-60°C for 8-12 min; in S5, cooling is performed by cooling to room temperature at a rate of 5-8°C / min.

[0017] A second aspect of the present invention is to provide a method for preparing a salt spray resistant additive containing an ionic liquid.

[0018] A third aspect of the present invention is to provide the application of a salt spray resistant additive containing an ionic liquid in a nickel-containing sealing agent.

[0019] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention creatively utilizes ion exchange to remove corrosion-inhibiting anions [DEHP] from functional ionic liquids. - Intercalation into the nanolayers of LDH endows the material with pH-responsive properties. When localized corrosion of the coating causes a rise in the pH of the micro-region, the OH groups in the environment... - Competitive ion exchange occurs between the LDH layer and the interlayer corrosion-inhibiting anions. To maintain charge balance, the LDH layer preferentially binds OH groups. - This triggers the directional release of intercalated corrosion-inhibiting anions, which can rapidly adsorb and form films at the active sites of the metal. The phosphate ester head groups connect P=O and PO.- It forms stable coordination bonds with the nickel surface to achieve chemical adsorption film formation, while the two 2-ethylhexyl long chains are oriented to form a dense hydrophobic barrier, preventing the penetration of corrosive media and achieving targeted and efficient corrosion protection.

[0020] 2. This invention not only intercalates corrosion-inhibiting anions into LDH, but also directly adds functionalized ionic liquids that are evenly distributed in the additives. The directly added functionalized ionic liquids can form preliminary protection through diffusion in the early stages of corrosion, delaying the occurrence of corrosion. If corrosion further develops and causes a significant increase in pH, a high concentration of corrosion inhibitor is released through the intercalated hybrid material to achieve powerful repair. Once corrosion is inhibited and pH drops, the release stops, overcoming the defect of traditional additives being consumed only once, and achieving long-lasting, self-repairing, and highly efficient protection.

[0021] 3. This invention also incorporates a low molecular weight gelling agent (12-hydroxystearic acid) into the salt spray resistant additive. During the coating and drying process, the gelling agent induces self-assembly through solvent evaporation and temperature changes, forming a fiber network that runs through the coating. This network firmly locks the ionic liquid molecules and LDH nanosheets within the network, preventing the loss of active components due to migration, seepage, or external erosion. This ensures that the coating's anti-corrosion performance does not rapidly decline over time. Even after long-term damp heat cycling and UV aging, its protective efficacy remains stable, significantly extending the product's reliable service life.

[0022] 4. This invention applies a salt spray resistant additive containing ionic liquid to a nickel-containing sealing agent, which can significantly improve the salt spray corrosion resistance and pitting resistance of the workpiece after sealing. It is suitable for aluminum alloy anodizing protection in the fields of aviation, automobiles, and 3C electronics. Detailed Implementation

[0023] The present invention will now be described in further detail with reference to specific embodiments.

[0024] Example 1 A salt spray resistant additive containing an ionic liquid is prepared by the following steps: S1: Under ice-water bath conditions, sodium hydroxide solution was added dropwise to di(2-ethylhexyl) phosphate, and the pH was adjusted to 7.3 to obtain an aqueous solution of di(2-ethylhexyl) phosphate. S2: An aqueous solution of sodium di(2-ethylhexyl)phosphate is added dropwise to an aqueous solution of methyltrioctylammonium chloride to carry out the reaction. The oil phase is collected after standing, washed four times with water at 45°C, and dried at 70°C until the water content of the functionalized ionic liquid is <0.7%. The aqueous solution of methyltrioctylammonium chloride is prepared by mixing methyltrioctylammonium chloride and deionized water at a mass ratio of 30:70. The molar ratio of di(2-ethylhexyl)phosphate to methyltrioctylammonium chloride is 1:1. S3: Nitrate-type layered double hydroxides were dispersed in anhydrous ethanol, sonicated, and the functionalized ionic liquid prepared in S2 was added. The mixture was stirred at 60°C for 22 h, and the solid product was collected by centrifugation and washed to obtain the intercalated hybrid material. The ratio of nitrate-type layered double hydroxides to anhydrous ethanol was 10 mg / mL, and the molar ratio of nitrate-type layered double hydroxides to functionalized ionic liquids was 1:1.5. S4: The functionalized ionic liquid, monoglyceride, and 12-hydroxystearic acid prepared in S2 were stirred at 75°C for 18 min. Then, 1,2-propanediol, Tween-80, and intercalated hybrid material were added sequentially and stirred at 55°C for 10 min to obtain a mixed phase. The mass ratio of the functionalized ionic liquid, monoglyceride, 12-hydroxystearic acid, 1,2-propanediol, Tween-80, and intercalated hybrid material was 7:1.2:0.1:2:3:1. S5: Add 0.1M acetate-sodium acetate buffer solution dropwise to the mixed phase and cool to room temperature at a rate of 7℃ / min to obtain a salt spray resistant additive containing ionic liquid; the mass of the acetate-sodium acetate buffer solution is 6 times the mass of the mixed phase.

[0025] The above-mentioned salt spray resistant additive containing ionic liquid is applied to nickel-containing sealing agents by adding the above-mentioned salt spray resistant additive containing ionic liquid at 5% (v / v) to the nickel-containing sealing agent, stirring evenly, applying it to the workpiece, and then drying it.

[0026] Example 2 A salt spray resistant additive containing an ionic liquid is prepared by the following steps: S1: Under ice-water bath conditions, sodium hydroxide solution was added dropwise to di(2-ethylhexyl) phosphate, and the pH was adjusted to 7.5 to obtain an aqueous solution of di(2-ethylhexyl) phosphate. S2: An aqueous solution of sodium di(2-ethylhexyl)phosphate is added dropwise to an aqueous solution of methyltrioctylammonium chloride to carry out the reaction. The oil phase is collected after standing, washed five times with water at 50°C, and dried at 75°C until the water content of the functionalized ionic liquid is <0.7%. The aqueous solution of methyltrioctylammonium chloride is prepared by mixing methyltrioctylammonium chloride and deionized water at a mass ratio of 32:68. The molar ratio of di(2-ethylhexyl)phosphate to methyltrioctylammonium chloride is 1:1. S3: Nitrate-type layered double hydroxides were dispersed in isopropanol, sonicated, and the functionalized ionic liquid prepared in S2 was added. The mixture was stirred at 65°C for 20 h, and the solid product was collected by centrifugation and washed to obtain the intercalated hybrid material. The ratio of nitrate-type layered double hydroxides to isopropanol was 12 mg / mL, and the molar ratio of nitrate-type layered double hydroxides to functionalized ionic liquid was 1:1.7. S4: The functionalized ionic liquid, monoglyceride, and 12-hydroxystearic acid prepared in S2 were stirred at 75°C for 15 min. Then, 1,2-propanediol, PEG-40 hydrogenated castor oil, and intercalation hybrid material were added sequentially and stirred at 60°C for 8 min to obtain a mixed phase. The mass ratio of the functionalized ionic liquid, monoglyceride, 12-hydroxystearic acid, 1,2-propanediol, PEG-40 hydrogenated castor oil, and intercalation hybrid material was 8:01.5:0.13:2.5:4:1.5. S5: Add 0.12M acetate-sodium acetate buffer solution dropwise to the mixed phase and cool to room temperature at a rate of 8℃ / min to obtain a salt spray resistant additive containing ionic liquid; the mass of the acetate-sodium acetate buffer solution is 7 times the mass of the mixed phase.

[0027] The above-mentioned salt spray resistant additive containing ionic liquid is applied to nickel-containing sealing agents by adding the above-mentioned salt spray resistant additive containing ionic liquid at 4% (v / v) to the nickel-containing sealing agent, stirring evenly, applying it to the workpiece, and then drying it.

[0028] Example 3 A salt spray resistant additive containing an ionic liquid is prepared by the following steps: S1: Under ice-water bath conditions, sodium hydroxide solution was added dropwise to di(2-ethylhexyl) phosphate, and the pH was adjusted to 7 to obtain an aqueous solution of di(2-ethylhexyl) phosphate. S2: An aqueous solution of sodium di(2-ethylhexyl)phosphate is added dropwise to an aqueous solution of methyltrioctylammonium chloride to carry out the reaction. The oil phase is collected after standing, washed five times with water at 40°C, and dried at 65°C until the water content of the functionalized ionic liquid is <0.7%. The aqueous solution of methyltrioctylammonium chloride is prepared by mixing methyltrioctylammonium chloride and deionized water at a mass ratio of 28:72. The molar ratio of di(2-ethylhexyl)phosphate to methyltrioctylammonium chloride is 1:1. S3: Nitrate-type layered double hydroxides were dispersed in anhydrous ethanol, sonicated, and the functionalized ionic liquid prepared in S2 was added. The mixture was stirred at 55°C for 24 h, and the solid product was collected by centrifugation and washed to obtain the intercalated hybrid material. The ratio of nitrate-type layered double hydroxides to anhydrous ethanol was 8 mg / mL, and the molar ratio of nitrate-type layered double hydroxides to functionalized ionic liquids was 1:1.3. S4: The functionalized ionic liquid, monoglyceride, and 12-hydroxystearic acid prepared in S2 were stirred at 70°C for 20 min. Then, 1,2-propanediol, Tween-80, and intercalated hybrid material were added sequentially and stirred at 50°C for 12 min to obtain a mixed phase. The mass ratio of the functionalized ionic liquid, monoglyceride, 12-hydroxystearic acid, 1,2-propanediol, Tween-80, and intercalated hybrid material was 6:0.8:0.06:1.5:2:0.6. S5: Add 0.08M acetate-sodium acetate buffer solution dropwise to the mixed phase and cool to room temperature at a rate of 5℃ / min to obtain a salt spray resistant additive containing ionic liquid; the mass of the acetate-sodium acetate buffer solution is 5 times the mass of the mixed phase.

[0029] The above-mentioned salt spray resistant additive containing ionic liquid is applied to nickel-containing sealing agents by adding the above-mentioned salt spray resistant additive containing ionic liquid at 4% (v / v) to the nickel-containing sealing agent, stirring evenly, applying it to the workpiece, and then drying it.

[0030] Example 4 A salt spray resistant additive containing an ionic liquid is prepared by the following steps: S1: Under ice-water bath conditions, sodium hydroxide solution was added dropwise to di(2-ethylhexyl) phosphate, and the pH was adjusted to 7 to obtain an aqueous solution of di(2-ethylhexyl) phosphate. S2: An aqueous solution of sodium di(2-ethylhexyl)phosphate is added dropwise to an aqueous solution of methyltrioctylammonium chloride to carry out the reaction. The oil phase is collected after standing, washed four times with water at 42°C, and dried at 68°C until the water content of the functionalized ionic liquid is <0.7%. The aqueous solution of methyltrioctylammonium chloride is prepared by mixing methyltrioctylammonium chloride and deionized water at a mass ratio of 29:71. The molar ratio of di(2-ethylhexyl)phosphate to methyltrioctylammonium chloride is 1:1. S3: Nitrate-type layered double hydroxides were dispersed in isopropanol, sonicated, and the functionalized ionic liquid prepared in S2 was added. The mixture was stirred at 65°C for 24 h, and the solid product was collected by centrifugation and washed to obtain the intercalated hybrid material. The ratio of nitrate-type layered double hydroxides to isopropanol was 9 mg / mL, and the molar ratio of nitrate-type layered double hydroxides to functionalized ionic liquid was 1:1.4. S4: The functionalized ionic liquid, monoglyceride, and 12-hydroxystearic acid prepared in S2 were stirred at 72°C for 16 min. Then, 1,2-propanediol, Tween-80, and intercalated hybrid material were added sequentially and stirred at 52°C for 9 min to obtain a mixed phase. The mass ratio of the functionalized ionic liquid, monoglyceride, 12-hydroxystearic acid, 1,2-propanediol, Tween-80, and intercalated hybrid material was 6.5:0.9:0.08:1.8:3:0.8. S5: Add 0.9M acetate-sodium acetate buffer solution dropwise to the mixed phase and cool to room temperature at a rate of 7℃ / min to obtain a salt spray resistant additive containing ionic liquid; the mass of the acetate-sodium acetate buffer solution is 6 times the mass of the mixed phase.

[0031] The above-mentioned salt spray resistant additive containing ionic liquid is applied to nickel-containing sealing agents by adding the above-mentioned salt spray resistant additive containing ionic liquid at 4% (v / v) to the nickel-containing sealing agent, stirring evenly, applying it to the workpiece, and then drying it.

[0032] Example 5 A salt spray resistant additive containing an ionic liquid is prepared by the following steps: S1: Under ice-water bath conditions, sodium hydroxide solution was added dropwise to di(2-ethylhexyl) phosphate, and the pH was adjusted to 7.4 to obtain an aqueous solution of di(2-ethylhexyl) phosphate. S2: An aqueous solution of sodium di(2-ethylhexyl)phosphate is added dropwise to an aqueous solution of methyltrioctylammonium chloride to carry out the reaction. The oil phase is collected after standing, washed three times with water at 48°C, and dried at 72°C until the water content of the functionalized ionic liquid is <0.7%. The aqueous solution of methyltrioctylammonium chloride is prepared by mixing methyltrioctylammonium chloride and deionized water at a mass ratio of 31:69. The molar ratio of di(2-ethylhexyl)phosphate to methyltrioctylammonium chloride is 1:1. S3: Nitrate-type layered double hydroxides were dispersed in anhydrous ethanol, sonicated, and the functionalized ionic liquid prepared in S2 was added. The mixture was stirred at 62°C for 23 h, and the solid product was collected by centrifugation and washed to obtain the intercalated hybrid material. The ratio of nitrate-type layered double hydroxides to anhydrous ethanol was 11 mg / mL, and the molar ratio of nitrate-type layered double hydroxides to functionalized ionic liquids was 1:1.6. S4: The functionalized ionic liquid, monoglyceride, and 12-hydroxystearic acid prepared in S2 were stirred at 74°C for 18 min. Then, 1,2-propanediol, PEG-40 hydrogenated castor oil, and intercalated hybrid material were added sequentially and stirred at 58°C for 11 min to obtain a mixed phase. The mass ratio of the functionalized ionic liquid, monoglyceride, 12-hydroxystearic acid, 1,2-propanediol, PEG-40 hydrogenated castor oil, and intercalated hybrid material was 7:1.4:0.12:2.2:3.5:1.2. S5: Add 0.11M acetate-sodium acetate buffer solution dropwise to the mixed phase and cool to room temperature at a rate of 7℃ / min to obtain a salt spray resistant additive containing ionic liquid; the mass of the acetate-sodium acetate buffer solution is 6 times the mass of the mixed phase.

[0033] The above-mentioned salt spray resistant additive containing ionic liquid is applied to nickel-containing sealing agents by adding the above-mentioned salt spray resistant additive containing ionic liquid at 4% (v / v) to the nickel-containing sealing agent, stirring evenly, applying it to the workpiece, and then drying it.

[0034] Comparative Example 1 It is basically the same as Example 1, except that no intercalation hybrid material is added, that is, step S3 is omitted.

[0035] Comparative Example 2 It is basically the same as Example 1, except that 12-hydroxystearic acid is not added.

[0036] Comparative Example 3 This is essentially the same as Example 1, except that: functionalized ionic liquids are not used, i.e., S1-S2 are omitted; and the functionalized ionic liquid in S3 is replaced with the same amount of sodium nitrate, i.e., [DEHP] in the intercalated hybrid material. - The corrosion-inhibiting anions were replaced with nitrate ions.

[0037] Comparative Example 4 It is basically the same as Example 1, except that the nickel-containing sealing agent does not contain salt spray resistant additives containing ionic liquids.

[0038] The performance of the additives prepared in Examples 1-5 and Comparative Examples 1-4 in nickel-containing sealing agents was tested, and the test results are shown in Table 1. The nickel-containing sealing agents used in Examples 1-5 and Comparative Examples 1-4 were commercially available nickel acetate-type sealing agents, with the following composition: nickel acetate (with Ni... 2+ (Calculated) 1.0-1.5 g / L, pH 5.5±0.3 (acetic acid / sodium acetate buffer), sealing temperature 90±2℃, time 20±2 min.

[0039] Neutral salt spray test: Refer to standard GB / T 10125, prepare a 5% sodium chloride solution, and adjust the pH to 6.5 to 7.2. Maintain the test chamber temperature at 35±2℃ and the saturation tower temperature at 47℃. Perform continuous spraying at a pressure of 70 to 170 kPa. Observe and record every 24 hours until red or white rust appears and the affected area exceeds 5%, then record the failure time.

[0040] Damp heat cycling test: Refer to standard GB / T 1740, set the temperature to 47±1℃, relative humidity to 96±2%, and continuously expose for 48 hours as one cycle. After the cycle, remove the product, allow it to recover at room temperature for 2 hours, and then perform a salt spray test after the surface is dry.

[0041] Ultraviolet aging test: Referencing standard GB / T 16422.3, a UV-A 340 nm lamp was used, with an irradiance of 0.76 W / m². 2The temperature during the illumination phase was 60±3℃, and during the condensation phase it was 50±3℃. The program was set to 8 hours of illumination plus 4 hours of condensation per cycle, with a total duration of 500 hours. Salt spray testing was performed after aging was completed.

[0042] Electrochemical impedance spectroscopy (EIS) testing: Following standard GB / T 19291, the electrolyte was 3.5% sodium chloride solution, and the temperature was 25±1℃. The frequency range was from 10... 5 -10 -2 The measurement is performed using a 10-20mV sinusoidal wave disturbance at Hz. Measurement points are logarithmically distributed, with 5-10 points per decade. The evaluation metric is the low-frequency impedance modulus at 0.01Hz; a higher value indicates better protection performance.

[0043] Table 1

[0044] As can be seen from Table 1, the salt spray resistant additives containing ionic liquids provided in Examples 1-5 of the present invention can significantly improve the salt spray corrosion resistance of nickel-containing sealing agents. After the workpieces are subjected to damp heat cycling and accelerated UV aging tests, the salt spray tolerance time can still be maintained at more than 1000h.

[0045] As can be seen from the comparative examples, Comparative Example 1 lacks intercalation hybrid materials, resulting in direct dispersion of the ionic liquid, uncontrollable release, and easy initial loss or aggregation, failing to achieve long-term and pH-responsive release, and significantly reducing impedance value and salt spray resistance time; Comparative Example 2, due to the lack of gelling factor (12-hydroxystearic acid), the intercalation hybrid materials are prone to sedimentation in the sealing agent and may be lost before the coating cures, unable to withstand aging tests such as damp heat and ultraviolet light, and the performance deteriorates sharply after aging; Comparative Example 3 uses ordinary anions, and because the intercalated LDH is nitrate ions without corrosion inhibition function, the lack of corrosion inhibition ability leads to a significant decrease in salt spray resistance; Comparative Example 4 does not add salt spray resistant additives and only relies on the nickel deposition film protection of the sealing agent itself, which has limited barrier and allows corrosive media to easily penetrate.

[0046] The above descriptions are merely some embodiments of the present invention. Those skilled in the art can make various modifications and improvements without departing from the inventive concept of the present invention, and these all fall within the scope of protection of the present invention.

Claims

1. A method for preparing a salt spray resistant additive containing an ionic liquid, characterized in that, Includes the following steps: S1: Under ice-water bath conditions, a neutralizing agent was added dropwise to di(2-ethylhexyl) phosphate, and the pH value was adjusted to obtain an aqueous solution of di(2-ethylhexyl) phosphate. S2: The sodium di(2-ethylhexyl)phosphate aqueous solution is added dropwise to the aqueous solution of methyltrioctylammonium chloride to carry out the reaction. The oil phase is collected after standing, and then washed and dried to obtain the functionalized ionic liquid. S3: Disperse the nitrate-type layered double hydroxide in a solvent, sonicate it, add the functionalized ionic liquid prepared by S2 to react, collect the solid product by centrifugation, and wash it to obtain the intercalated hybrid material. S4: The functionalized ionic liquid, monoglyceride and 12-hydroxystearic acid prepared in S2 are premixed, and then the co-surfactant, emulsifier and intercalation hybrid material are added in sequence to obtain a mixed phase; S5: Add a buffer solution dropwise to the mixed phase, and after cooling, obtain the salt spray resistant additive containing ionic liquid.

2. The method for preparing the salt spray resistant additive containing ionic liquid according to claim 1, characterized in that, The neutralizing agent is a sodium hydroxide solution, which adjusts the pH value to 7-7.5; the aqueous solution of methyltrioctylammonium chloride is prepared by mixing methyltrioctylammonium chloride and deionized water in a mass ratio of 28-32:68-72; the molar ratio of di(2-ethylhexyl)phosphate to methyltrioctylammonium chloride is 1:

1.

3. The method for preparing the salt spray resistant additive containing ionic liquid according to claim 1, characterized in that, The solvent is selected from at least one of anhydrous ethanol and isopropanol; the ratio of the nitrate-type layered double hydroxide to the solvent is 8-12 mg / mL; in S3, the molar ratio of the nitrate-type layered double hydroxide to the functionalized ionic liquid is 1:1.3-1.

7.

4. The method for preparing the salt spray resistant additive containing ionic liquid according to claim 1, characterized in that, In S4, the mass ratio of functionalized ionic liquid, monoglyceride, 12-hydroxystearic acid, co-surfactant, emulsifier and intercalation hybrid material is 6-8:0.8-1.5:0.06-0.13:1.5-2.5:2-4:0.6-1.

5.

5. The method for preparing the salt spray resistant additive containing ionic liquid according to claim 4, characterized in that, The co-surfactant is 1,2-propanediol; the emulsifier is selected from at least one of Tween-80 and PEG-40 hydrogenated castor oil.

6. The method for preparing the salt spray resistant additive containing ionic liquid according to claim 1, characterized in that, The buffer solution is a 0.08-0.12M acetate-sodium acetate buffer solution, and the mass of the buffer solution is 5-7 times the mass of the mixed phase.

7. The method for preparing the salt spray resistant additive containing ionic liquid according to claim 1, characterized in that, In step S2, washing is performed 3-5 times with water at 40-50℃, and drying is performed at 65-75℃ until the water content of the functionalized ionic liquid is <0.7%; in step S3, the reaction is performed by stirring at 55-65℃ for 20-24 hours.

8. The method for preparing the salt spray resistant additive containing ionic liquid according to claim 1, characterized in that, In step S4, premixing involves stirring at 70-75°C for 15-20 minutes, and mixing involves stirring at 50-60°C for 8-12 minutes; in step S5, cooling involves cooling to room temperature at a rate of 5-8°C / min.

9. A salt spray resistant additive containing an ionic liquid prepared by the preparation method of the salt spray resistant additive containing an ionic liquid according to any one of claims 1-8.

10. The application of the salt spray resistant additive containing ionic liquid as described in claim 9 in a nickel-containing sealing agent.

Images