Nickel-free hole sealing agent and preparation method thereof

Abstract

The invention relates to a nickel-free hole sealing agent and a preparation method thereof, and belongs to the technical field of high polymer materials. The nickel-free hole sealing agent comprises the following components in parts by weight: 3-10 parts of cobalt acetate, 1-11 parts of a corrosion-resistant modifier, 1-6 parts of ethylenediamine tetraacetic acid, 3-7 parts of sodium silicate and 5-15 parts of deionized water, an intermediate product containing bis-imidazoline in the corrosion-resistant modifier is tightly adsorbed on the metal surface by virtue of electrostatic attraction and a large pi bond to form a tough protective film, so that a water-phase corrosive medium is effectively isolated, the corrosion speed is remarkably reduced, and meanwhile, the corrosion-resistant modifier has good heat-resistant stability and still has a corrosion inhibition effect in a high-temperature environment; the glycine enables the nickel-free hole sealing agent to better fill tiny holes in the metal surface, so that the surface is flat and smooth, and uniform distribution and permeation of the hole sealing agent are promoted; quaternary ammonium salt destroys cell walls and cell membranes of microorganisms and inhibits growth and reproduction of the microorganisms; the nickel-free hole sealing agent prepared by the invention not only has a good antistatic effect, but also has excellent high-temperature-resistant and antibacterial effects.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer materials, and particularly relates to a nickel-free sealing agent and a preparation method thereof. Background Art

[0002] Due to its advantages such as light weight, strong corrosion resistance, good thermal and electrical conductivity, aluminum alloy is widely used in the fields of aviation, aerospace, automotive, machinery manufacturing and civil industry. Anodizing is the main method for surface treatment of aluminum alloy, but the formed oxide film is porous and has high chemical activity. If high-quality sealing is not carried out, pollutants in the environment will be adsorbed by the micropores and cause corrosion of the base material, reducing the service life of the aluminum material.

[0003] Sealing treatment can significantly improve the corrosion resistance of anodized aluminum alloy. At present, nickel fluoride-based sealing agents are basically used in the production of aluminum building profiles. However, this kind of sealing agent has high contents of nickel ions and fluorides, causing great pollution to the environment and harm to the operators. At the same time, traditional nickel-free sealing agents are prone to corrosion under high temperature and harsh environments. Therefore, it is of great practical significance and application value to develop a nickel-free sealing agent with excellent performance. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a nickel-free sealing agent and a preparation method thereof.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A nickel-free sealing agent and a preparation method thereof, comprising the following raw materials in parts by weight: 3-10 parts of cobalt acetate, 1-11 parts of corrosion-resistant modifier, 1-6 parts of ethylenediaminetetraacetic acid, 3-7 parts of sodium silicate, and 5-15 parts of deionized water.

[0007] The corrosion-resistant modifier is prepared by the following method:

[0008] Step A1: Mix n-butylamine and ethylene glycol and stir evenly, then slowly dropwise add epichlorohydrin, control the temperature in a water bath at 40°C. After the addition is complete, react for 12 h, filter, and dry to obtain a compound.

[0009] Further, the dosage ratio of n-butylamine, ethylene glycol, and epichlorohydrin is 7.81-14.82 g: 10 mL: 4.62-9.24 mL;

[0010] First, use the amino group of n-butylamine to react with epichlorohydrin to synthesize a compound.

[0011] Step A2: Mix glycine and o-xylene evenly, heat up to 90°C, then slowly dropwise add tetraethylenepentamine, and then heat up to 150°C and react for 4 h. Then raise the temperature to 190°C and react for 4 h to obtain an intermediate product.

[0012] Furthermore, the dosage ratio of glycine, o-xylene, and tetraethylenepentamine is 1.5 - 3 g : 50 mL : 1.89 - 3.79 mL;

[0013] Secondly, utilize the amidation reaction between the carboxyl group of glycine and the amino group of tetraethylenepentamine, and then cyclize to obtain an intermediate product containing bis-imidazoline;

[0014] Step A3: Mix the compound and the intermediate product evenly, then put them into a rotary evaporator, set the temperature to 80 °C, adjust the rotation speed to 80 r / min, after quaternization reaction for 10 h, cool down to obtain the corrosion-resistant modifier;

[0015] Furthermore, the dosage ratio of the compound to the intermediate product is 0.1 - 0.2 mol : 0.05 - 0.1 mol;

[0016] Finally, utilize the chlorine atom of the compound to cause the intermediate product to undergo quaternary ammonium saltification reaction to synthesize the corrosion-resistant modifier.

[0017] A preparation method of a nickel-free sealing agent specifically includes the following steps:

[0018] S1. Mix cobalt acetate, the corrosion-resistant modifier, ethylenediaminetetraacetic acid, and sodium silicate evenly to obtain a mixed material;

[0019] S2. Mix the mixed material and deionized water evenly, stir at 250 - 300 r / min and 30 - 35 °C for 10 - 20 min to obtain the nickel-free sealing agent.

[0020] Advantages of the present invention:

[0021] The nickel-free sealing agent of the present invention has good corrosion resistance, and at the same time also has excellent high-temperature resistance and antibacterial effects, which can extend the service life of the material.

[0022] The corrosion-resistant modifier prepared by the present invention contains an intermediate product with bis-imidazoline. Its five-membered nitrogen-containing heterocyclic structure is tightly adsorbed on the metal surface by electrostatic attraction and large π bonds, forming a tough protective film, effectively isolating the aqueous corrosion medium, and significantly reducing the corrosion rate. When the nitrogen atom of the imidazoline ring is converted into a quaternary ammonium salt, its positive charge attracts the negative charge on the metal surface, effectively inhibiting the anodic reaction. At the same time, a hydrophobic protective film is formed to further enhance the isolation effect. At the same time, the O and N atoms in the intermediate product have the ability to donate electrons, can form coordination bonds with the metal surface, change the surface charge distribution and interfacial properties, increase the activation energy of the metal ionization process, and inhibit corrosion. In addition, the good heat stability of the intermediate product ensures that it still has a corrosion inhibition effect in high-temperature environments. The addition of glycine makes the nickel-free sealant better fill the micro-holes on the metal surface, making the surface flat and smooth, reducing the interfacial tension, and promoting the uniform distribution and penetration of the sealant. In addition, the quaternary ammonium salt also has antibacterial effects. By destroying the cell walls and cell membranes of microorganisms and interfering with their metabolic processes, it makes them lose their activity and inhibits their growth and reproduction. Detailed implementation manners

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0024] Example 1: A preparation method of a nickel-free sealant specifically includes the following steps:

[0025] S1. Weigh raw materials by weight parts: 3 parts of cobalt acetate, 1 part of corrosion-resistant modifier (prepared by this example), 1 part of ethylenediaminetetraacetic acid, 3 parts of sodium silicate, and 5 parts of deionized water; mix cobalt acetate, corrosion-resistant modifier, ethylenediaminetetraacetic acid, and sodium silicate evenly to obtain a mixed material.

[0026] S2. Mix the mixed material and deionized water evenly, and stir at 250 r / min and 30 °C for 10 min to obtain a nickel-free sealant.

[0027] The corrosion-resistant modifier is prepared by the following method:

[0028] Step A1: Mix 7.81 g of n-butylamine and 10 mL of ethylene glycol evenly, and then slowly add 4.62 mL of epichlorohydrin dropwise. Control the temperature in a water bath at 40 °C. After the dropwise addition is completed, react for 12 h, filter, and dry to obtain a compound.

[0029] Step A2: Mix 1.5 g of glycine and 50 mL of o - xylene evenly, heat up to 90 °C, then slowly add dropwise 1.89 mL of tetraethylenepentamine. Subsequently, heat up to 150 °C and react for 4 h. Then raise the temperature to 190 °C and react for 4 h to obtain an intermediate product;

[0030] Step A3: Mix 0.1 mol of the compound and 0.05 mol of the intermediate product evenly, then put them into a rotary evaporator. Set the temperature to 80 °C and the rotation speed to 80 r / min. After quaternization reaction for 10 h, cool down to obtain a corrosion - resistant modifier.

[0031] Example 2: A preparation method of a nickel - free sealing agent specifically includes the following steps:

[0032] S1. Weigh raw materials by weight parts: 6.5 parts of cobalt acetate, 6 parts of corrosion - resistant modifier (prepared by this example), 3.5 parts of ethylenediaminetetraacetic acid, 5 parts of sodium silicate, and 10 parts of deionized water; Mix cobalt acetate, corrosion - resistant modifier, ethylenediaminetetraacetic acid, and sodium silicate evenly to obtain a mixed material;

[0033] S2. Mix the mixed material and deionized water evenly, stir at 275 r / min and 32.5 °C for 15 min to obtain a nickel - free sealing agent;

[0034] The corrosion - resistant modifier is prepared by the following method:

[0035] Step A1: Mix 11.315 g of n - butylamine and 10 mL of ethylene glycol evenly, then slowly add dropwise 6.93 mL of epichlorohydrin. Control the temperature of the water bath at 40 °C. After the addition is complete, react for 12 h, filter, and dry to obtain a compound;

[0036] Step A2: Mix 2.25 g of glycine and 50 mL of o - xylene evenly, heat up to 90 °C, then slowly add dropwise 2.84 mL of tetraethylenepentamine. Subsequently, heat up to 150 °C and react for 4 h. Then raise the temperature to 190 °C and react for 4 h to obtain an intermediate product;

[0037] Step A3: Mix 0.15 mol of the compound and 0.075 mol of the intermediate product evenly, then put them into a rotary evaporator. Set the temperature to 80 °C and the rotation speed to 80 r / min. After quaternization reaction for 10 h, cool down to obtain a corrosion - resistant modifier.

[0038] Example 3: A preparation method of a nickel - free sealing agent specifically includes the following steps:

[0039] S1. Weigh the raw materials by weight parts: 10 parts of cobalt acetate, 11 parts of corrosion-resistant modifier (prepared in this example), 6 parts of ethylenediaminetetraacetic acid, 7 parts of sodium silicate, and 15 parts of deionized water; mix cobalt acetate, corrosion-resistant modifier, ethylenediaminetetraacetic acid, and sodium silicate evenly to obtain a mixed material;

[0040] S2. Mix the mixed material and deionized water evenly, stir at 300 r / min and 35 °C for 20 min to obtain a nickel-free sealing agent;

[0041] The corrosion-resistant modifier is prepared by the following method:

[0042] Step A1: Mix 14.82 g of n-butylamine and 10 mL of ethylene glycol evenly, then slowly add 9.24 mL of epichlorohydrin dropwise. Control the temperature in a water bath at 40 °C. After the dropwise addition is completed, react for 12 h, filter, and dry to obtain a compound;

[0043] Step A2: Mix 3 g of glycine and 50 mL of o-xylene evenly, heat up to 90 °C, then slowly add 3.79 mL of tetraethylenepentamine dropwise, and then heat up to 150 °C and react for 4 h. Then raise the temperature to 190 °C and react for 4 h to obtain an intermediate product;

[0044] Step A3: Mix 0.2 mol of the compound and 0.1 mol of the intermediate product evenly, then put them into a rotary evaporator. Set the temperature to 80 °C and the rotation speed to 80 r / min. After the quaternization reaction for 10 h, cool down to obtain the corrosion-resistant modifier.

[0045] Comparative example: This comparative example is a nickel-free sealing agent. The difference from Example 3 is that an equal amount of alumina is used to replace the corrosion-resistant modifier prepared in Example 3, and the rest are the same.

[0046] Performance test: Immerse the nickel-free sealing agents prepared in Examples 1 - 3 and the comparative example in aluminum alloy profiles for sealing for 5 min, then put them into a high-temperature tube furnace at 700 °C for corrosion test. The simulated atmosphere is introduced into the tube furnace by a mass flowmeter to corrode the metal specimen, and the gas flow rate is 100 mL / min. The simulated flue gas composition is: 15% CO₂, 3.5% - 5% O₂, 0.35% SO₂, and the balance is N₂. After the test for 200 h, wait for the high-temperature furnace to cool down to room temperature and then take out; use a salt spray solution with a sodium chloride concentration of 50 g / L, spray it with a sodium chloride aqueous solution at 35 °C for 16 h, then take out and place the substrate in another constant temperature and humidity chamber at 40 °C and a relative humidity of 80%, observe the substrate, record the time when abnormalities appear on the surface, and test the salt spray resistance; conduct antibacterial tests according to the standard SN / T2399 - 2010; the test results are shown in Table 1 below:

[0047] Table 1

[0048]

[0049] As can be seen from the data tested in Table 1, the nickel-free sealing agent prepared by the present invention has good corrosion resistance. It can also be seen from the above table that the nickel-free sealing agent prepared by the present invention has high temperature resistance and antibacterial effects, and can extend the service life of the material.

[0050] The above content is only an example and illustration of the concept of the present invention. Those skilled in the art of this technology can make various modifications or supplements to the described specific embodiments or use similar methods for substitution. As long as they do not deviate from the concept of the invention or exceed the scope defined by this claims, they should all fall within the protection scope of the present invention.

Claims

1. A method for preparing a nickel-free sealing agent, characterized in that: The specific steps include: S1. Weigh the raw materials by weight, including 3-10 parts of cobalt acetate, 1-11 parts of corrosion-resistant modifier, 1-6 parts of ethylenediaminetetraacetic acid, 3-7 parts of sodium silicate, and 5-15 parts of deionized water; uniformly mix the cobalt acetate, corrosion-resistant modifier, ethylenediaminetetraacetic acid and sodium silicate to obtain a mixed material; S2. Evenly mix the mixture and deionized water, and stir for 10-20 minutes at 250-300 r / min and 30-35° C. to obtain a nickel-free sealing agent.

2. The method for preparing a nickel-free sealing agent according to claim 1, characterized in that: The corrosion resistant modifier is prepared by the following method: Step A1: n-butylamine and ethylene glycol were mixed and stirred evenly, and then epichlorohydrin was slowly added dropwise, and the temperature of the water bath was controlled at 40° C. After the addition was completed, the reaction was carried out for 12 hours, and the mixture was filtered and dried to obtain a compound; Step A2: Glycine and o-xylene are mixed evenly, heated to 90°C, and tetraethylenepentamine is slowly added dropwise, then heated to 150°C, reacted for 4 hours, and then the temperature is raised to 190°C, reacted for 4 hours to obtain an intermediate product; Step A3: The compound and the intermediate product are mixed evenly, and then placed in a rotary evaporator, the temperature is set to 80° C., the speed is adjusted to 80 r / min, and after quaternization reaction for 10 hours, the temperature is lowered to obtain a corrosion-resistant modifier.

3. The method for preparing a nickel-free sealing agent according to claim 2, characterized in that: In step A1, the dosage ratio of n-butylamine, ethylene glycol and epichlorohydrin is 7.81-14.82 g:10 mL:4.62-9.24 mL.

4. The method for preparing a nickel-free sealing agent according to claim 2, characterized in that: In step A2, the usage ratio of glycine, o-xylene and tetraethylenepentamine is 1.5-3 g:50 mL:1.89-3.79 mL.

5. The method for preparing a nickel-free sealing agent according to claim 2, characterized in that: The usage ratio of the compound and the intermediate product in step A3 is 0.1-0.2 mol: 0.05-0.1 mol.

6. A nickel-free sealing agent, characterized in that: Prepared according to the preparation method according to any one of claims 1 to 5.

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