A tin wire externally provided with a moisture-absorbing and non-sticky coating and a preparation process thereof

Abstract

The present application relates to soldering technology field, specifically to a kind of tin wire with moisture-proof and non-adhesive coating outside and its preparation process, steps are as follows: using atomization spraying method, the prepared coating liquid is uniformly sprayed on the surface of tin wire, then the tin wire with coating liquid sprayed is placed in rotating coating device with gel powder, rotates 5-8min under 180-260r / min, finally drying can be done.The present application, by spraying coating liquid on the surface of tin wire, then gel powder is attached to the surface of tin wire, so as to build double-sol layer on the surface of tin wire, so that moisture can form water droplet on the surface of coating and slide, so that the surface of tin wire is not easy to attach moisture, and the double-sol layer formed has good durability, not easy to break, so that the dryness of the surface of tin wire can be kept for a long time, so that tin wire can be prevented from exploding or exploding due to moisture.

Description

Technical Field

[0001] This invention relates to the field of soldering technology, specifically to a solder wire with an external moisture-proof and non-stick coating and its preparation process. Background Technology

[0002] In electronic packaging, solder wire is a common soldering material used in manual or semi-automatic machine soldering. It is typically used for electrical or mechanical connections between electronic devices and components. During soldering, the solder wire is filled with rosin. When the soldering iron reaches a high temperature, the molten solder coats the rosin. The rosin rapidly vaporizes at the high temperature, breaking open the encapsulated solder and producing a popping sound. Small, shiny, solid solder beads are also ejected – this is known as solder splattering. During storage, moisture in the air, especially during the rainy season, can cause the solder wire to become damp, leading to continuous solder splattering or bursting. This not only risks splattering molten solder onto the operator's hands and causing burns, but also affects the quality of the soldering.

[0003] For example, the invention patent with announcement number CN113996972A discloses a flux for preventing whitening of solder wire and its preparation method. This patent uses a reasonable compounding of a moisture-proofing agent, an antioxidant, a nonionic surfactant, and an activator with water-absorbing properties to prepare a flux suitable for water-resistant solder wire. Spraying this flux onto the surface of the solder wire can improve its water resistance. However, because this patent imparts water resistance to the solder wire by adding a moisture-proofing agent to the flux, during the storage period of the solder wire, if there is a long rainy season, the prolonged high humidity will cause the moisture-proofing agent to become saturated. Excessive moisture will not only remain on the solder wire, but will also cause the flux coating on the surface of the solder wire to peel off, thus causing the solder wire to lose its water resistance. Moreover, the coating formed by the flux on the surface of the solder wire has poor wear resistance, and collisions and friction between the fluxes can easily cause damage to the coating, resulting in the coating losing its protective function for the solder wire. This prevents the surface of the solder wire from drying for a long time, causing the solder wire to still experience solder splattering or bursting during soldering.

[0004] How to keep the surface of solder wire dry for a long time during the rainy season, thereby eliminating solder splattering or bursting during soldering, is one of the urgent problems that all solder wire manufacturers need to solve. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a tin wire with an external moisture-proof and non-stick coating and its preparation process.

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

[0007] A method for preparing a tin wire with an external moisture-proof and non-stick coating, comprising the following steps:

[0008] The prepared coating liquid is evenly sprayed onto the surface of the tin wire using an atomization spraying method. Then, the tin wire coated with the coating liquid and the gel powder are placed together in a spin coating device and rotated at 180-260 r / min for 5-8 minutes. Finally, it is dried.

[0009] As a further preferred embodiment of the present invention, the coating liquid has a spraying thickness of 10-20 μm;

[0010] The mass of the gel powder accounts for 0.5-1.5% of the total mass of the tin wire.

[0011] As a further preferred embodiment of the present invention, the coating liquid contains the following raw material components in parts by weight: 40-50 parts of bisphenol A epoxy resin, 10-16 parts of rosin resin, 5-10 parts of melamine, 3-7 parts of phenyl glycidyl ether, 5-9 parts of triphenylphosphine, 0.5-2.5 parts of succinic acid, 1-2 parts of organosilicon surfactant, 1-2 parts of γ-aminopropyltriethoxysilane, 0.5-1.3 parts of polyamide wax, 3-6 parts of hydrophobic composite particles, and 2-4 parts of microcapsules;

[0012] The preparation method is as follows: According to the weight parts, add bisphenol A type epoxy resin, rosin resin, phenyl glycidyl ether and organosilicon surfactant into the reaction vessel, stir and heat to 90-120℃. After the bisphenol A type epoxy resin is completely dissolved, cool to room temperature, then add melamine, triphenylphosphine, succinic acid, hydrophobic composite particles and microcapsules in sequence, mix well, then add γ-aminopropyltriethoxysilane and polyamide wax, mix well and let stand and filter.

[0013] As a further preferred embodiment of the present invention, the method for preparing the hydrophobic composite particles is as follows:

[0014] 1) Zinc nitrate solution and sodium stearate are placed in a container and placed in a water bath at 90-93℃. Stir for 5-10 minutes, then add sodium hydroxide solution and continue stirring for 1-3 hours. The resulting suspension is filtered and separated, washed repeatedly with distilled water, and dried to obtain hydrophobic nano zinc oxide.

[0015] 2) Under sufficient light and at 0-5℃, hydrophobic nano zinc oxide was added to sodium dodecyl sulfate solution and stirred for 10-20 min. Then, sodium alginate aqueous solution, silver nitrate solution and ascorbic acid solution were added in sequence while stirring. The reaction was continued for 2-4 h. After centrifugation, washing and drying were performed to obtain hydrophobic composite particles.

[0016] As a further preferred embodiment of the present invention, the ratio of the amount of zinc nitrate solution, sodium stearate and sodium hydroxide solution is (50-80) mL: (20-50) mg: (50-80) mL;

[0017] The concentration of the zinc nitrate solution is 0.23-0.28 mol / L, and the concentration of the sodium hydroxide solution is 0.52-0.55 mol / L;

[0018] The ratio of the amounts of the hydrophobic nano zinc oxide, sodium dodecyl sulfate solution, sodium alginate aqueous solution, silver nitrate solution, and ascorbic acid solution is (1-3) g : (30-50) mL : (50-100) μL : (0.4-0.6) mL : (0.1-0.3) mL;

[0019] The concentration of the sodium dodecyl sulfate solution is 0.003-0.006 mol / L, the concentration of the silver nitrate solution is 0.5-0.8 mg / L, and the concentration of the ascorbic acid solution is 0.12-0.16 mol / L.

[0020] As a further preferred embodiment of the present invention, the method for preparing the microcapsules is as follows:

[0021] 1) Dissolve sodium molybdate, hydroxylamine hydrochloride and thiourea in deionized water, then add benzyltriethylammonium chloride, adjust the pH to 5.5-6.5, stir magnetically for 1-2 hours, then transfer to a hydrothermal reactor and react at 180-190℃ for 20-26 hours. After cooling to room temperature, wash, centrifuge and dry to obtain molybdenum sulfide microspheres.

[0022] 2) Mix urea and 36-39 wt% formaldehyde solution, add triethanolamine to adjust the pH to 8-9, and stir at 70-75℃ for 1-3 hours to obtain urea-formaldehyde resin prepolymer. Mix linseed oil, sodium dodecylbenzenesulfonate and molybdenum sulfide microspheres, add 1-3 drops of n-octanol, stir and disperse in distilled water, emulsify for 20-30 minutes to obtain core material emulsion. Slowly add urea-formaldehyde resin prepolymer to core material emulsion and disperse at 20000-30000 r / min for 2-5 minutes. Then add ammonium chloride and resorcinol in sequence, continue stirring for 2-3 hours, adjust the pH to 3-4 with dilute hydrochloric acid, and react at 75-78℃ for 2-5 hours. Adjust the pH to 7 with sodium hydroxide solution, cool, filter, and spray dry to obtain microcapsules.

[0023] As a further preferred embodiment of the present invention, the proportions of sodium molybdate, hydroxylamine hydrochloride, thiourea, deionized water, and benzyltriethylammonium chloride are (8.5-10.2)g:(7.2-8.6)g:(1.2-2.3)g:(50-90)mL:(0.3-0.6)g;

[0024] The urea and formaldehyde solution are mixed at a molar ratio of 1:(1.7-1.9);

[0025] The ratio of linseed oil, sodium dodecylbenzenesulfonate, molybdenum sulfide microspheres, and distilled water is (20-30) mL : (1-2) g : (0.5-1.2) g : (100-150) mL;

[0026] The urea-formaldehyde resin prepolymer and the core material emulsion are mixed at a core-to-wall ratio of (2.5-3.5):5.

[0027] The ammonium chloride and resorcinol account for 1-2% and 0.7-1.8% of the total mass of the core material emulsion, respectively;

[0028] In the spray drying process, the air pressure is 3-10 bar, the air velocity is 4.3-5.2 m / s, and the peristaltic pump feed rate is 900-1000 mL / h.

[0029] As a further preferred embodiment of the present invention, the method for preparing the gel powder is as follows:

[0030] 1) Water glass with a SiO2 mass fraction of 4-6% is passed through a cation exchange resin column at a rate of 10-15 mL / min to obtain a silicic acid solution. The pH value is adjusted to 4-5, stirred for 5-15 min and then allowed to stand. Then it is placed in the mixed solution and soaked for 23-27 h to obtain an aged wet gel.

[0031] 2) Immerse the aged wet gel in anhydrous ethanol, then soak the gel in n-hexane, and finally soak it in a hexane solution of trimethylchlorosilane for 15-20 hours. After taking it out, repeatedly soak and wash it with n-hexane, place it at room temperature for 20-25 hours, and then place it in a constant temperature drying oven to dry it at 75-100℃, 135-155℃ and 200-210℃ for 2-3 hours respectively. After ultra-fine pulverization, the gel powder is obtained.

[0032] As a further preferred embodiment of the present invention, the mixture is composed of deionized water and anhydrous ethanol in a volume ratio of 1:(8-9); the trimethylchlorosilane n-hexane solution has a volume ratio of trimethylchlorosilane to n-hexane of 1:(10-12); when the aged wet gel is soaked in anhydrous ethanol and n-hexane, the solvent is changed every 10-12 hours, for a total of 3-5 times.

[0033] A tin wire with an external moisture-proof and non-sticky coating is prepared by the above-described method.

[0034] Compared with the prior art, the beneficial effects of the present invention are:

[0035] In this invention, sodium stearate is used as a surface modifier, and a direct liquid-phase precipitation method is employed to prepare hydrophobic nano-zinc oxide in situ. Then, using the hydrophobic nano-zinc oxide as a deposition matrix and sodium alginate as a polymer chain, under light irradiation and low temperature, the aggregation of silver atoms can be controlled to a limited extent by introducing polymer chains. This reaction generates hexagonal silver nanosheet structures with clear edges, which are then deposited and grown on the hydrophobic nano-zinc oxide, resulting in hydrophobic composite particles. Furthermore, continuous stirring during the reaction process can inhibit the aggregation of the hydrophobic nano-zinc oxide, thus promoting the uniform deposition and growth of silver nanosheets. On hydrophobic zinc nanoparticles, by adding these hydrophobic composite particles to the coating liquid, the coating can be made to have excellent hydrophobicity, allowing water to form droplets on the coating surface and slide off, thus making it difficult for water to adhere to the surface of the solder wire, thereby preventing the solder wire from cracking or bursting due to moisture. At the same time, because silver nanosheets are deposited on the surface of the hydrophobic composite particles, the layered structure of the nano-silver can significantly hinder dislocation movement and increase the microhardness of the coating, thereby giving the coating significant anti-wear and friction-reducing properties, making the coating highly wear-resistant and less prone to friction damage.

[0036] In this invention, linseed oil and molybdenum sulfide microspheres are used as the core material, and urea-formaldehyde resin is used as the wall material. Microcapsules are prepared using a two-step method. When the coating is damaged, the microcapsules rupture under the action of microcrack expansion, releasing linseed oil at the cracks. The oil then polymerizes with oxygen in the air, and the resulting polymer fills the damaged area, thus repairing the coating and allowing the coating on the surface of the tin wire to maintain its structural integrity for a long time. At the same time, as the microcapsules rupture, the molybdenum sulfide microspheres in the core material are released and transferred to the wear grooves of the coating, playing a good filling and repair role. This reduces the wear of the coating and further improves the wear resistance and friction reduction performance of the coating.

[0037] In this invention, water glass is used as the raw material and trimethylchlorosilane as the hydrophobic modifier. A hydrophobic gel powder is prepared by sol-gel method and drying under normal pressure. This gel powder is then coated onto the surface of a tin wire, working in conjunction with the coating to form a double hydrophobic layer on the tin wire surface. This not only further improves the moisture resistance of the tin wire surface, but also, because the gel powder has a nanoporous structure with dense and uniform pore distribution, it can seal a large amount of air within the pores, forming an insulating air layer. This creates a barrier that can slow down or inhibit the penetration of external corrosive media, thus preventing the coating from being damaged by external corrosive media and improving the durability of the coating.

[0038] In this invention, after spraying a coating liquid onto the surface of the solder wire, gel powder is then attached to the surface of the solder wire to create a double-repellent layer. This allows moisture to form droplets on the coating surface and slide off, making it difficult for moisture to adhere to the surface of the solder wire. Furthermore, the double-repellent layer has excellent durability and is not easily damaged, thus keeping the surface of the solder wire dry for a long time and preventing the solder wire from cracking or bursting due to moisture. Detailed Implementation

[0039] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] Example 1

[0041] A method for preparing a tin wire with an external moisture-proof and non-stick coating, comprising the following steps:

[0042] The prepared coating liquid is evenly sprayed onto the surface of the tin wire using an atomization spraying method. Then, the tin wire coated with the coating liquid and the gel powder are placed together in a spin coating device and rotated at 180 r / min for 5 min. Finally, it is dried.

[0043] The coating liquid has a spraying thickness of 10μm;

[0044] The mass of the gel powder accounts for 0.5% of the total mass of the tin wire.

[0045] The preparation method of the above-mentioned gel powder is as follows:

[0046] 1) SiO2 with a mass fraction of 4% water glass was passed through a cation exchange resin column at a rate of 10 mL / min to obtain a silicic acid solution. The pH was adjusted to 4 with 1.0 mol / L hydrochloric acid solution. After stirring for 5 min, the solution was allowed to stand and then placed in a mixture of deionized water and anhydrous ethanol in a volume ratio of 1:8 for 23 h to obtain an aged wet gel.

[0047] 2) Immerse the aged wet gel in anhydrous ethanol, changing the solvent every 10 hours for 3 times. Then, soak the gel in n-hexane, changing the solvent every 10 hours for 3 times. Finally, immerse it in a solution of trimethylchlorosilane in n-hexane for 15 hours, with a volume ratio of trimethylchlorosilane to n-hexane of 1:10. After removal, repeatedly soak and wash with n-hexane, place at room temperature for 20 hours, and then place in a constant temperature drying oven to dry at 75℃, 135℃, and 200℃ for 2 hours respectively. After ultra-fine pulverization, obtain gel powder.

[0048] The above coating liquid contains the following raw material components in parts by weight: 40 parts bisphenol A epoxy resin, 10 parts rosin resin, 5 parts melamine, 3 parts phenyl glycidyl ether, 5 parts triphenylphosphine, 0.5 parts succinic acid, 1 part organosilicon surfactant, 1 part γ-aminopropyltriethoxysilane, 0.5 parts polyamide wax, 3 parts hydrophobic composite particles, and 2 parts microcapsules;

[0049] The preparation method is as follows: According to the weight parts, add bisphenol A epoxy resin, rosin resin, phenyl glycidyl ether and organosilicon surfactant into the reaction vessel, stir and heat to 90°C. After the bisphenol A epoxy resin is completely dissolved, cool to room temperature, then add melamine, triphenylphosphine, succinic acid, hydrophobic composite particles and microcapsules in sequence, mix well, then add γ-aminopropyltriethoxysilane and polyamide wax, mix well and let stand and filter.

[0050] The preparation method of the hydrophobic composite particles is as follows:

[0051] 1) 50 mL of 0.23 mol / L zinc nitrate solution and 20 mg of sodium stearate were placed in a container and placed in a 90°C water bath. The mixture was stirred at 600 r / min for 5 min. Then, 50 mL of 0.52 mol / L sodium hydroxide solution was added and the mixture was stirred for another 1 h. The resulting suspension was filtered and separated, washed repeatedly with distilled water, and dried at 80°C to constant weight to obtain hydrophobic nano zinc oxide.

[0052] 2) Under sufficient light and at 0℃, 1g of hydrophobic nano zinc oxide was added to 30mL of sodium dodecyl sulfate solution with a concentration of 0.003mol / L. The mixture was stirred at 700r / min for 10min. Then, while stirring, 50μL of sodium alginate aqueous solution with a concentration of 0.5mg / L, 0.4mL of silver nitrate solution with a concentration of 0.01mol / L, and 0.1mL of ascorbic acid solution with a concentration of 0.12mol / L were added in sequence. The mixture was stirred and reacted for 2h. After centrifugation, washing, and drying, hydrophobic composite particles were obtained.

[0053] The preparation method of the microcapsules is as follows:

[0054] 1) Weigh out 8.5g sodium molybdate, 7.2g hydroxylamine hydrochloride and 1.2g thiourea and dissolve them in 50mL deionized water. Then add 0.3g benzyltriethylammonium chloride and adjust the pH to 5.5 with 2mol / L hydrochloric acid. After stirring magnetically for 1h, transfer to a hydrothermal reactor and react at 180℃ for 20h. After cooling to room temperature, wash repeatedly with anhydrous ethanol and deionized water, centrifuge, and vacuum dry at 60℃ for 10h to obtain molybdenum sulfide microspheres.

[0055] 2) Urea and 36wt% formaldehyde solution were mixed at a molar ratio of 1:1.7. Triethanolamine was added to adjust the pH to 8. The mixture was stirred at 70℃ for 1 hour to obtain urea-formaldehyde resin prepolymer. 20 mL of linseed oil, 1 g of sodium dodecylbenzenesulfonate and 0.5 g of molybdenum sulfide microspheres were mixed and 1 drop of n-octanol was added. The mixture was stirred at 120 r / min and dispersed in 100 mL of distilled water. The mixture was emulsified for 20 minutes to obtain a core material emulsion. The urea-formaldehyde resin prepolymer was slowly added to the core material emulsion at a core-to-wall ratio of 2.5:5. The mixture was dispersed at 20000 r / min for 2 minutes. Then, 1% and 0.7% of ammonium chloride and resorcinol, respectively, were added to the core material emulsion. The mixture was stirred for 2 hours. The pH was adjusted to 3 with dilute hydrochloric acid and reacted at 75℃ for 2 hours. The pH was adjusted to 7 with sodium hydroxide solution. After cooling, filtration and spray drying, microcapsules were obtained.

[0056] In the spray drying process, the air pressure was 3 bar, the air velocity was 4.3 m / s, and the peristaltic pump feed rate was 900 mL / h.

[0057] Example 2

[0058] A method for preparing a tin wire with an external moisture-proof and non-stick coating, comprising the following steps:

[0059] The prepared coating liquid is evenly sprayed onto the surface of the tin wire using an atomization spraying method. Then, the tin wire coated with the coating liquid and the gel powder are placed together in a spin coating device and rotated at 230 r / min for 6 min. Finally, it is dried.

[0060] The coating liquid has a spraying thickness of 15μm;

[0061] The mass of the gel powder accounts for 1% of the total mass of the tin wire.

[0062] The preparation method of the above-mentioned gel powder is as follows:

[0063] 1) A silicic acid solution was obtained by passing water glass with a SiO2 mass fraction of 5% through a cation exchange resin column at a rate of 12 mL / min. The pH value was adjusted to 4.5 with 1.3 mol / L hydrochloric acid solution, stirred for 10 min and then allowed to stand. The solution was then placed in a mixture of deionized water and anhydrous ethanol in a volume ratio of 1:8.5 and soaked for 25 h to obtain an aged wet gel.

[0064] 2) Immerse the aged wet gel in anhydrous ethanol, changing the solvent every 11 hours for 4 times. Then, soak the gel in n-hexane, changing the solvent every 11 hours for 4 times. Finally, immerse it in a solution of trimethylchlorosilane in n-hexane for 18 hours, with a volume ratio of trimethylchlorosilane to n-hexane of 1:11. After removal, repeatedly soak and wash with n-hexane, place at room temperature for 23 hours, and then place in a constant temperature drying oven to dry at 90℃, 140℃, and 205℃ for 2.5 hours respectively. After ultra-fine pulverization, obtain gel powder.

[0065] The coating liquid contains the following raw material components in parts by weight: 45 parts bisphenol A epoxy resin, 15 parts rosin resin, 7 parts melamine, 5 parts phenyl glycidyl ether, 6 parts triphenylphosphine, 1.5 parts succinic acid, 1.5 parts organosilicon surfactant, 1.5 parts γ-aminopropyltriethoxysilane, 0.9 parts polyamide wax, 4 parts hydrophobic composite particles, and 3 parts microcapsules;

[0066] The preparation method is as follows: According to the weight parts, add bisphenol A epoxy resin, rosin resin, phenyl glycidyl ether and organosilicon surfactant into the reaction vessel, stir and heat to 110°C. After the bisphenol A epoxy resin is completely dissolved, cool to room temperature, then add melamine, triphenylphosphine, succinic acid, hydrophobic composite particles and microcapsules in sequence, mix well, then add γ-aminopropyltriethoxysilane and polyamide wax, mix well and let stand and filter.

[0067] The preparation method of the hydrophobic composite particles is as follows:

[0068] 1) 65 mL of 0.25 mol / L zinc nitrate solution and 40 mg of sodium stearate were placed in a container and placed in a 92°C water bath. The mixture was stirred at 700 r / min for 6 min. Then, 65 mL of 0.53 mol / L sodium hydroxide solution was added and the mixture was stirred for another 2 h. The resulting suspension was filtered and separated, washed repeatedly with distilled water, and dried at 85°C to constant weight to obtain hydrophobic nano zinc oxide.

[0069] 2) Under sufficient light and at 3℃, 2g of hydrophobic nano zinc oxide was added to 40mL of sodium dodecyl sulfate solution with a concentration of 0.005mol / L. The mixture was stirred at 800r / min for 15min. Then, while stirring, 70μL of sodium alginate aqueous solution with a concentration of 0.6mg / L, 0.5mL of silver nitrate solution with a concentration of 0.02mol / L, and 0.2mL of ascorbic acid solution with a concentration of 0.15mol / L were added in sequence. The mixture was stirred and reacted for 3h. After centrifugation, washing, and drying, hydrophobic composite particles were obtained.

[0070] The preparation method of the microcapsules is as follows:

[0071] 1) Weigh out 9.6g sodium molybdate, 7.8g hydroxylamine hydrochloride and 1.8g thiourea and dissolve them in 70mL deionized water. Then add 0.5g benzyltriethylammonium chloride and adjust the pH to 6 with 2.5mol / L hydrochloric acid. After stirring magnetically for 1.5h, transfer to a hydrothermal reactor and react at 185℃ for 23h. After cooling to room temperature, wash repeatedly with anhydrous ethanol and deionized water, centrifuge, and vacuum dry at 70℃ for 12h to obtain molybdenum sulfide microspheres.

[0072] 2) Urea and 37wt% formaldehyde solution were mixed at a molar ratio of 1:1.8. Triethanolamine was added to adjust the pH to 8.5. The mixture was stirred at 72℃ for 2 hours to obtain urea-formaldehyde resin prepolymer. 25mL of linseed oil, 1.5g of sodium dodecylbenzenesulfonate and 0.8g of molybdenum sulfide microspheres were mixed and 2 drops of n-octanol were added. The mixture was stirred at 150r / min and dispersed in 120mL of distilled water. The emulsification was carried out for 25 minutes to obtain core material emulsion. The urea-formaldehyde resin prepolymer was slowly added to the core material emulsion at a core-to-wall ratio of 3:5. The mixture was dispersed at 25000r / min for 3 minutes. Then, 1.5% and 1.2% of ammonium chloride and resorcinol were added sequentially according to the total mass of the core material emulsion. The mixture was stirred for 2.5 hours. The pH was adjusted to 3.5 with dilute hydrochloric acid. The mixture was kept at 76℃ for 3 hours. The pH was adjusted to 7 with sodium hydroxide solution. After cooling, filtration and spray drying, microcapsules were obtained.

[0073] In the spray drying process, the air pressure is 8 bar, the air velocity is 5 m / s, and the peristaltic pump feed rate is 1000 mL / h.

[0074] Example 3

[0075] A method for preparing a tin wire with an external moisture-proof and non-stick coating, comprising the following steps:

[0076] The prepared coating liquid is evenly sprayed onto the surface of the tin wire using an atomization spraying method. Then, the tin wire coated with the coating liquid and the gel powder are placed together in a spin coating device and rotated at 260 r / min for 8 minutes. Finally, it is dried.

[0077] The coating liquid has a spraying thickness of 20μm;

[0078] The mass of the gel powder accounts for 1.5% of the total mass of the tin wire.

[0079] The preparation method of the above-mentioned gel powder is as follows:

[0080] 1) A silicic acid solution was obtained by passing water glass with a SiO2 mass fraction of 6% through a cation exchange resin column at a rate of 15 mL / min. The pH value was adjusted to 5 with 1.5 mol / L hydrochloric acid solution, stirred for 15 min and then allowed to stand. The solution was then placed in a mixture of deionized water and anhydrous ethanol in a volume ratio of 1:9 and soaked for 27 h to obtain an aged wet gel.

[0081] 2) Immerse the aged wet gel in anhydrous ethanol, changing the solvent every 12 hours for 5 times. Then, soak the gel in n-hexane, changing the solvent every 12 hours for 5 times. Finally, immerse it in a solution of trimethylchlorosilane in n-hexane for 20 hours, with a volume ratio of trimethylchlorosilane to n-hexane of 1:12. After removal, repeatedly soak and wash with n-hexane, place at room temperature for 25 hours, and then place in a constant temperature drying oven to dry at 100℃, 155℃, and 210℃ for 3 hours respectively. After ultra-fine pulverization, obtain gel powder.

[0082] The coating liquid contains the following raw material components in parts by weight: 50 parts bisphenol A epoxy resin, 16 parts rosin resin, 10 parts melamine, 7 parts phenyl glycidyl ether, 9 parts triphenylphosphine, 2.5 parts succinic acid, 2 parts organosilicon surfactant, 2 parts γ-aminopropyltriethoxysilane, 1.3 parts polyamide wax, 6 parts hydrophobic composite particles, and 4 parts microcapsules;

[0083] The preparation method is as follows: By weight, add bisphenol A epoxy resin, rosin resin, phenyl glycidyl ether and organosilicon surfactant to the reaction vessel, stir and heat to 120°C. After the bisphenol A epoxy resin is completely dissolved, cool to room temperature, then add melamine, triphenylphosphine, succinic acid, hydrophobic composite particles and microcapsules in sequence, mix well, then add γ-aminopropyltriethoxysilane and polyamide wax, mix well and let stand and filter.

[0084] The preparation method of the hydrophobic composite particles is as follows:

[0085] 1) 80 mL of 0.28 mol / L zinc nitrate solution and 50 mg of sodium stearate were placed in a container and placed in a 93°C water bath. The mixture was stirred at 800 r / min for 10 min. Then, 80 mL of 0.55 mol / L sodium hydroxide solution was added and the mixture was stirred for another 3 h. The resulting suspension was filtered and separated, washed repeatedly with distilled water, and dried at 90°C to constant weight to obtain hydrophobic nano zinc oxide.

[0086] 2) Under sufficient light and at 5℃, 3g of hydrophobic nano zinc oxide was added to 50mL of sodium dodecyl sulfate solution with a concentration of 0.006mol / L. The mixture was stirred at 1000r / min for 20min. Then, while stirring, 100μL of sodium alginate aqueous solution with a concentration of 0.8mg / L, 0.6mL of silver nitrate solution with a concentration of 0.02mol / L, and 0.3mL of ascorbic acid solution with a concentration of 0.16mol / L were added in sequence. The reaction was continued to be stirred for 4h. After centrifugation, washing, and drying, hydrophobic composite particles were obtained.

[0087] The preparation method of the microcapsules is as follows:

[0088] 1) Weigh out 10.2g of sodium molybdate, 8.6g of hydroxylamine hydrochloride and 2.3g of thiourea and dissolve them in 90mL of deionized water. Then add 0.6g of benzyltriethylammonium chloride and adjust the pH to 6.5 with 3mol / L hydrochloric acid. After stirring magnetically for 2h, transfer the mixture to a hydrothermal reactor and react at 190℃ for 26h. After cooling to room temperature, wash and centrifuge repeatedly with anhydrous ethanol and deionized water, and vacuum dry at 80℃ for 15h to obtain molybdenum sulfide microspheres.

[0089] 2) Urea and 39wt% formaldehyde solution were mixed at a molar ratio of 1:1.9. Triethanolamine was added to adjust the pH to 9. The mixture was stirred at 75℃ for 3 hours to obtain urea-formaldehyde resin prepolymer. 30mL of linseed oil, 2g of sodium dodecylbenzenesulfonate and 1.2g of molybdenum sulfide microspheres were mixed and 3 drops of n-octanol were added. The mixture was stirred at 180r / min and dispersed in 150mL of distilled water. The mixture was emulsified for 30 minutes to obtain core material emulsion. The urea-formaldehyde resin prepolymer was slowly added to the core material emulsion at a core-to-wall ratio of 3.5:5. The mixture was dispersed at 30000r / min for 5 minutes. Then, 2% and 1.8% of ammonium chloride and resorcinol, respectively, were added to the core material emulsion. The mixture was stirred for 3 hours. The pH was adjusted to 4 with dilute hydrochloric acid and the mixture was reacted at 78℃ for 5 hours. The pH was adjusted to 7 with sodium hydroxide solution. After cooling, filtration and spray drying, microcapsules were obtained.

[0090] In the spray drying process, the air pressure was 10 bar, the air velocity was 5.2 m / s, and the peristaltic pump feed rate was 1000 mL / h.

[0091] Comparative Example 1: This comparative example is basically the same as Example 1, except that the coating liquid does not contain hydrophobic composite particles.

[0092] Comparative Example 2: This comparative example is basically the same as Example 1, except that the coating liquid does not contain microcapsules.

[0093] Comparative Example 3: This comparative example is basically the same as Example 1, except that the surface of the tin wire is not coated with gel powder.

[0094] Test experiment:

[0095] The tin wire samples provided in Examples 1-3 and Comparative Examples 1-3 were placed on a shaker at a speed of 50 rpm under conditions of 50°C and 90% humidity for 3 months. The weight gain rate of the tin wire samples after storage was tested, and the results are shown in Table 1.

[0096] Table 1

[0097] Example 1 Example 2 Example 3 Weight gain rate % 0.23 0.20 0.27 Comparative Example 1 Comparative Example 2 Comparative Example 3 Weight gain rate % 2.5 2.8 6.3

[0098] As can be seen from Table 1, the tin wire in this invention has a double hydrophobic layer on its surface, which has excellent durability and good self-repair properties. This makes the tin wire have a low weight gain rate and is not easy to absorb moisture in a high humidity environment, thus keeping the surface of the tin wire dry for a long time and preventing the tin wire from cracking or bursting due to moisture.

[0099] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for preparing a tin wire with an external moisture-proof and non-sticky coating, characterized in that, The steps are as follows: The prepared coating liquid is evenly sprayed onto the surface of the tin wire using an atomization spraying method. Then, the tin wire coated with the coating liquid and the gel powder are placed together in a spin coating device and rotated at 180-260 r / min for 5-8 min. Finally, it is dried. The coating liquid is sprayed to a thickness of 10-20 μm; The mass of the gel powder accounts for 0.5-1.5% of the total mass of the tin wire; the gel powder is prepared by using water glass as raw material and trimethylchlorosilane as hydrophobic modifier, and by drying under normal pressure using the sol-gel method. The coating liquid contains the following raw material components in parts by weight: 40-50 parts of bisphenol A epoxy resin, 10-16 parts of rosin resin, 5-10 parts of melamine, 3-7 parts of phenyl glycidyl ether, 5-9 parts of triphenylphosphine, 0.5-2.5 parts of succinic acid, 1-2 parts of organosilicon surfactant, 1-2 parts of γ-aminopropyltriethoxysilane, 0.5-1.3 parts of polyamide wax, 3-6 parts of hydrophobic composite particles, and 2-4 parts of microcapsules; the microcapsules are prepared by a two-step method using linseed oil and molybdenum sulfide microspheres as the core material and urea-formaldehyde resin as the wall material.

2. The method for preparing a tin wire with an external moisture-proof and non-adhesive coating according to claim 1, characterized in that, The coating liquid is prepared as follows: Bisphenol A epoxy resin, rosin resin, phenyl glycidyl ether and organosilicon surfactant are added to the reaction vessel by weight, stirred and heated to 90-120°C. After the bisphenol A epoxy resin is completely dissolved, it is cooled to room temperature. Then, melamine, triphenylphosphine, succinic acid, hydrophobic composite particles and microcapsules are added in sequence. After mixing, γ-aminopropyltriethoxysilane and polyamide wax are added. After mixing, it is allowed to stand and filtered.

3. The method for preparing a tin wire with an external moisture-proof and non-sticky coating according to claim 1, characterized in that, The preparation method of the hydrophobic composite particles is as follows: 1) Zinc nitrate solution and sodium stearate are placed in a container and placed in a water bath at 90-93℃. Stir for 5-10 minutes, then add sodium hydroxide solution and continue stirring for 1-3 hours. The resulting suspension is filtered and separated, washed repeatedly with distilled water, and dried to obtain hydrophobic nano zinc oxide. 2) Under sufficient light and at 0-5℃, hydrophobic nano zinc oxide was added to sodium dodecyl sulfate solution and stirred for 10-20 min. Then, sodium alginate aqueous solution, silver nitrate solution and ascorbic acid solution were added in sequence while stirring. The reaction was continued for 2-4 h. After centrifugation and washing, the mixture was dried to obtain hydrophobic composite particles.

4. The method for preparing a tin wire with an external moisture-proof and non-adhesive coating according to claim 3, characterized in that, The ratio of zinc nitrate solution, sodium stearate and sodium hydroxide solution used is (50-80) mL : (20-50) mg : (50-80) mL; The concentration of the zinc nitrate solution is 0.23-0.28 mol / L, and the concentration of the sodium hydroxide solution is 0.52-0.55 mol / L; The ratio of the amounts of the hydrophobic nano zinc oxide, sodium dodecyl sulfate solution, sodium alginate aqueous solution, silver nitrate solution, and ascorbic acid solution is (1-3) g : (30-50) mL : (50-100) μL : (0.4-0.6) mL : (0.1-0.3) mL; The concentration of the sodium dodecyl sulfate solution is 0.003-0.006 mol / L, the concentration of the silver nitrate solution is 0.5-0.8 mg / L, and the concentration of the ascorbic acid solution is 0.12-0.16 mol / L.

5. The method for preparing a tin wire with an external moisture-proof and non-adhesive coating according to claim 3, characterized in that, The microcapsules are prepared as follows: 1) Dissolve sodium molybdate, hydroxylamine hydrochloride and thiourea in deionized water, then add benzyltriethylammonium chloride, adjust the pH to 5.5-6.5, stir magnetically for 1-2 hours, then transfer to a hydrothermal reactor and react at 180-190℃ for 20-26 hours. After cooling to room temperature, wash, centrifuge and dry to obtain molybdenum sulfide microspheres. 2) Mix urea and 36-39 wt% formaldehyde solution, adjust the pH to 8-9, and stir at 70-75℃ for 1-3 hours to obtain urea-formaldehyde resin prepolymer. Mix linseed oil, sodium dodecylbenzenesulfonate and molybdenum sulfide microspheres, add 1-3 drops of n-octanol, stir and disperse in distilled water, emulsify for 20-30 minutes to obtain core material emulsion. Slowly add urea-formaldehyde resin prepolymer to core material emulsion and disperse at 20000-30000 r / min for 2-5 minutes. Then add ammonium chloride and resorcinol in sequence, continue stirring for 2-3 hours, adjust the pH to 3-4, and react at 75-78℃ for 2-5 hours. Then adjust the pH to 7, cool, filter, and spray dry to obtain microcapsules.

6. The method for preparing a tin wire with an external moisture-proof and non-adhesive coating according to claim 5, characterized in that, The proportions of sodium molybdate, hydroxylamine hydrochloride, thiourea, deionized water, and benzyltriethylammonium chloride are (8.5-10.2) g : (7.2-8.6) g : (1.2-2.3) g : (50-90) mL : (0.3-0.6) g; the urea and formaldehyde solution are mixed in a molar ratio of 1 : (1.7-1.9). The ratio of linseed oil, sodium dodecylbenzenesulfonate, molybdenum sulfide microspheres, and distilled water is (20-30) mL : (1-2) g : (0.5-1.2) g : (100-150) mL; The urea-formaldehyde resin prepolymer and the core material emulsion are mixed at a core-to-wall ratio of (2.5-3.5):5; the ammonium chloride and resorcinol account for 1-2% and 0.7-1.8% of the total mass of the core material emulsion, respectively. In the spray drying process, the air pressure is 3-10 bar, the air velocity is 4.3-5.2 m / s, and the peristaltic pump feed rate is 900-1000 mL / h.

7. The method for preparing a tin wire with an external moisture-proof and non-sticky coating according to claim 1, characterized in that, The preparation method of the gel powder is as follows: 1) A silicic acid solution is obtained by passing water glass with a SiO2 mass fraction of 4-6% through a cation exchange resin column at a rate of 10-15 mL / min. The pH value is adjusted to 4-5, stirred for 5-15 min and then allowed to stand. The solution is then placed in the mixed solution and soaked for 23-27 h to obtain an aged wet gel. 2) Immerse the aged wet gel in anhydrous ethanol, then soak the gel in n-hexane, and finally soak it in a hexane solution of trimethylchlorosilane for 15-20 hours. After taking it out, repeatedly soak and wash it with n-hexane, place it at room temperature for 20-25 hours, and then place it in a constant temperature drying oven to dry it at 75-100℃, 135-155℃ and 200-210℃ for 2-3 hours respectively. After ultra-fine pulverization, the gel powder is obtained.

8. The method for preparing a tin wire with an external moisture-proof and non-adhesive coating according to claim 7, characterized in that, The mixture is composed of deionized water and anhydrous ethanol in a volume ratio of 1:(8-9); the trimethylchlorosilane n-hexane solution has a volume ratio of trimethylchlorosilane to n-hexane of 1:(10-12); when the aged wet gel is soaked in anhydrous ethanol and n-hexane, the solvent is changed every 10-12 hours, for a total of 3-5 times.

9. A tin wire with an external moisture-proof and non-stick coating, characterized in that, It is prepared by the preparation method described in any one of claims 1-8.