Environment-friendly water-based sealing agent for radio frequency coaxial connector and preparation method of environment-friendly water-based sealing agent

Abstract

The invention discloses an environment-friendly water-based sealing agent for a radio frequency coaxial connector. The environment-friendly water-based sealing agent is prepared from the following raw materials in parts by weight: 3-5 parts of a film-forming agent, 1-3 parts of a corrosion inhibitor, 12-18 parts of a surfactant, 0.1-1 part of a defoaming agent, 0.2-0.4 part of an auxiliary agent, 1.5-3 parts of a complexing agent and the balance of water, wherein the total amount is 100 parts. The invention discloses a preparation method and a use method of an environment-friendly water-based sealing agent for a connector, and the method comprises the following steps: firstly, mixing a film-forming agent and a corrosion inhibitor according to a certain proportion, uniformly stirring at a rotating speed of 300-500 revolutions per minute, sequentially adding a surfactant, an auxiliary agent and a complexing agent, heating the solution to a molten state, slowly adding a defoaming agent, and uniformly stirring at a rotating speed of 300-500 revolutions per minute to obtain the environment-friendly water-based sealing agent for the connector. And finally, adding distilled water or deionized water with the temperature of 50 DEG C, continuously stirring for 10-20 minutes, stopping stirring and heating until the solution is uniform and free of bubbles, and cooling the solution to room temperature to obtain a white or light yellow solid concentrated solution.

Description

Technical Field

[0001] The present invention relates to the technical field of anti-corrosion of electroplated metal surfaces, and particularly relates to an environment-friendly water-based sealant for radio frequency coaxial connectors and a preparation method thereof. Background Art

[0002] Radio frequency coaxial connectors are widely used in various electronic devices. As a common electronic component, the connector is a bridge for transmission and has a wide range of applications in fields such as 5G new infrastructure construction, aerospace interconnection products, satellite communication, radar communication, manned spaceflight, and outer space exploration. The quality of its performance directly affects the quality of the product.

[0003] After the connector is electroplated, the produced metal coating (the coating is often silver) often contains various organic or inorganic substances and is more likely to oxidize, discolor, and corrode, affecting its service performance. Therefore, in order to improve the protection performance of the electroplated layer (such as insertion loss, temperature-humidity cycle, insertion and extraction force, etc.), a post-treatment process of dip-coating a sealant is usually adopted to achieve the purpose of improving the anti-corrosion performance of the connector and extending its service life.

[0004] With the gradual increase in the market scale of China's electroplating industry, the demand for sealants has also increased accordingly. Combining with the requirements of relevant national environmental protection policies, the use of environment-friendly water-based sealants can achieve clean production, improve resource utilization rate, adapt to the current situation of fierce market competition, and has great application prospects. Summary of the Invention

[0005] In order to solve the problems existing in the above-mentioned prior art, such as uneven coating and mottling after dip-coating the sealant, resulting in an increase in the resistance of the connector and a short anti-corrosion life, the present invention provides an efficient sealant for radio frequency coaxial connectors.

[0006] To achieve the above object, the technical solution of the present invention is as follows:

[0007] An environment-friendly water-based sealant for radio frequency coaxial connectors is composed of the following raw materials in parts by weight: 3-5 parts of a film-forming agent, 1-3 parts of a corrosion inhibitor, 12-18 parts of a surfactant, 0.1-1 part of an antifoaming agent, 0.2-0.4 part of an auxiliary agent, 1.5-3 parts of a complexing agent, and water is added to 100 parts.

[0008] Further, the film-forming agent is one or more of thiol compounds (n-hexadecyl mercaptan or n-octadecyl mercaptan); by adopting the above thiol compounds, the present invention can undergo a spontaneous chemical reaction on the surface of the metal coating to form a self-assembled metal protective film, so that the surface of the coating has good corrosion resistance.

[0009] Further, the corrosion inhibitor is one or more of 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, and azole compounds (benzotriazole fatty amine salts, methylbenzotriazole, phenyltetrazole). The corrosion inhibitors are all organic substances. The polar groups therein adsorb on the metal surface, which can change the electric double layer structure of the metal surface and increase the activation energy of the ionization process of metal atoms. The non-polar groups are arranged in a directional manner away from the metal surface to form a hydrophobic dense film, which becomes a diffusion barrier for corrosive ions, preventing the metal coating from reacting with surrounding media such as sulfides, halides, ozone, and humid air, thereby achieving the purpose of anti-corrosion.

[0010] Further, the surfactant is one or two of alkylphenol polyoxyethylene ethers (OP-9, OP-10). Since the film-forming agent and the corrosion inhibitor are organic substances insoluble in water, adding a non-ionic surfactant can form an oil-in-water emulsion system with the corrosion inhibitor and water, making it spread better on the metal surface.

[0011] Further, the auxiliaries are Span 80 and water-soluble lanolin, which, as emulsifiers and co-emulsifiers, help to form an oil-in-water emulsion system.

[0012] Further, the defoamer is silicone. The silicone defoamer can help eliminate the foam generated by the surfactant during the formation of the oil-in-water emulsion system, thereby reducing the surface tension and increasing the gas-liquid contact surface.

[0013] Further, the complexing agent is one or more of disodium ethylenediaminetetraacetate (EDTA-2Na), trisodium citrate, and diethylenetriaminepentaacetic acid (DTPA). The complexing agent has the ability to chelate metal ions and plays an auxiliary role during the film-forming process.

[0014] Further, the water is distilled water or deionized water. Using distilled water or deionized water can avoid the corrosion of the metal by oxygen in the water and the pollution of the sealer by metal ions such as calcium, magnesium, and aluminum, and improve the use efficiency.

[0015] All the raw materials used in the present invention are commercially available.

[0016] The present invention also provides a preparation method and a use method for the environment-friendly water-based sealer for connectors. The method includes the following steps: First, mix the film-forming agent and the corrosion inhibitor in a certain proportion, stir evenly under stirring at a speed of 300 - 500 revolutions per minute, and then sequentially add the surfactant, the auxiliaries, and the complexing agent. Heat the solution to the molten state and slowly add the defoamer. Finally, add distilled water or deionized water at 50°C, continue stirring for 10 - 20 minutes until the solution is uniform and bubble-free, then stop stirring and heating. After the solution cools to room temperature, the solution state is a white or light yellow solid concentrate.

[0017] During use: 1. Weigh an appropriate amount of concentrated liquid; 2. Heat it until it becomes transparent; 3. Add warm water at 50°C and stir (recommended ratio 10 - 20%); 4. Immerse the workpiece in the working fluid for 30 - 90 s or more; 5. When taking out, rinse it 2 - 3 times with warm water at 40 - 50°C, and then air dry or dry it in an oven.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] The sealing agent of the present invention is applied to the sealing protection of radio frequency coaxial connectors. It can not only form a dense anti-corrosion film on the surface of the metal coating of the connector, which can greatly extend its service life; but also the preparation operation process is simple, the dosage is small, the coating is uniform, there are no obvious mottles, and it does not affect the appearance of the original coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 For the surface condition of the K 2 S test in Example 1;

[0021] Figure 2 For the surface condition of the K 2 S test in Example 4;

[0022] Figure 3 For the surface condition of the K 2 S test in Comparative Example 2 for application. DETAILED DESCRIPTION OF THE INVENTION

[0023] The technical solution of the present invention will be further described in detail below in conjunction with the drawings and specific embodiments:

[0024] As Figures 1-3 shown, the weight parts of the raw materials of the sealing agent in Examples 1 - 5 are as follows:

[0025]

[0026]

[0027] The performance test of the sealing agent prepared in Examples 1 - 5 and the comparison results of its use with other sealing agents are shown in the following table

[0028] Evaluation and comparison:

[0029]

[0030] The above is only the specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any change or replacement that can be thought of without creative work should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope defined by the claims.

Claims

1. An environmentally friendly water-based sealant for radio frequency coaxial connectors, characterized in that: The invention is composed of the following raw materials in parts by weight: 3-5 parts of film former, 1-3 parts of corrosion inhibitor, 12-18 parts of surfactant, 0.1-1 parts of defoamer, 0.2-0.4 parts of auxiliary agent, 1.5-3 parts of complexing agent and water added to 100 parts.

2. The sealing agent according to claim 1, characterized in that The film-forming agent is one or more of n-hexadecyl mercaptan and n-n-octadecyl mercaptan.

3. The sealing agent according to claim 1, characterized in that The corrosion inhibitor is one or more of 2-mercaptobenzimidazole, 2-mercaptobenzothiazole or benzotriazole fatty amino salt, methylbenzotriazole and phenyltetrazolyl.

4. The sealing agent according to claim 1, characterized in that The surfactant is one or two of alkylphenol polyoxyethylene ether OP-9 and OP-10.

5. The sealing agent according to claim 1, characterized in that The auxiliary agents are Span 80 and water-soluble lanolin, which serve as emulsifiers and co-emulsifiers and are helpful in forming an oil-in-water emulsion system.

6. The sealing agent according to claim 1, characterized in that The defoaming agent is organic silicon.

7. The sealing agent according to claim 1, characterized in that The complexing agent is one or more of ethylenediaminetetraacetic acid disodium salt (EDTA-2Na), trisodium citrate, and diethylenetriaminepentaacetic acid (DTPA). The complexing agent has the ability to chelate metal ions and plays an auxiliary role in the film-forming process.

8. The sealing agent according to claim 1, characterized in that The water is distilled water or deionized water.

9. A method for preparing a sealing agent according to any one of claims 1 to 8, comprising the following steps: First, mix the film-forming agent and corrosion inhibitor in a certain proportion, stir at a speed of 300-500 rpm until uniform, then add surfactants, additives and complexing agents in sequence, heat the solution to a molten state and slowly add defoaming agent, finally add 50°C distilled water or deionized water, continue stirring for 10-20 minutes, stop stirring and heating when the solution is uniform and free of bubbles, and after the solution is cooled to room temperature, the solution is a white or light yellow solid concentrate.

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