A coating liquid system for improving the durability of gold and silver threads and its application

Abstract

The application provides a coating liquid system for improving the durability of gold and silver threads and an application thereof, and comprises a foaming type primer liquid used for foaming a coating; a atomizing type transition coating liquid used for atomizing the coating; and a long-acting protection type coating liquid, wherein the long-acting protection type coating liquid at least comprises a compound type high molecular resin emulsion, a mesoporous silica loaded with benzotriazole and an epoxy group modified barium sulfate, and the compound type high molecular resin emulsion is a compound mixed solution of a carboxyl acrylate emulsion, N-hydroxymethyl acrylamide, polyvinyl alcohol and a polyurethane emulsion. The compound mixed solution can solve the protection problem of the exposed cross section after slitting without affecting the size precision, production efficiency and decoration performance of the gold and silver threads.

Description

Technical Field

[0001] This invention relates to the field of polyester gold and silver wire preparation and protection technology, specifically to gold and silver wire surface protective coating technology, and particularly to a coating liquid system for improving the durability of gold and silver wire and its application. Background Technology

[0002] Polyester gold and silver wire is a flat decorative thread made by coating polyester aluminized film with a polymer resin protective layer, and then physically cutting it. It is a core decorative dressing widely used in clothing, footwear, art decoration, stage decoration and other fields. Its decorative effect and durability directly determine the quality and service life of the end product.

[0003] Currently, the industrial mass production of polyester gold and silver wire generally adopts a process of first coating the entire surface with a protective layer and then longitudinally shearing the wire. However, during the slitting process of processing the film into flat wires, completely exposed cross-sections are inevitably formed at the cut points. These exposed cross-sections are not covered by any protective coating, making them susceptible to moisture and oxygen intrusion. This creates a "weak window" for electrochemical corrosion, easily causing localized corrosion of the gold and silver wire, leading to overall color reduction or even complete fading, severely damaging its decorative effect. However, the field of metal wire protection faces a contradiction between all-round coating protection and the precise dimensional control of industrial production. It is not possible to achieve effective protection of the cut cross-section simply through conventional processes such as recoating after slitting or overall secondary impregnation. Specifically, polyester gold and silver filaments are micron-level ultra-thin flat wires. If they are slit and then coated or impregnated with a traditional protective liquid, an additional coating will be applied to the front and back surfaces of the gold and silver filaments that have already been protected. This will directly lead to excessive filament thickness, width deformation, and even filament adhesion, tangling, brittleness, and complete loss of processing adaptability. As a result, the yield rate of mass production is extremely low. Summary of the Invention

[0004] This application provides a coating liquid system for improving the durability of gold and silver wires and its application, aiming to solve the problem of protecting the exposed cross-section after slitting without affecting the dimensional accuracy, production efficiency, and decorative performance of the gold and silver wires.

[0005] In a first aspect, embodiments of this application provide a coating liquid system for improving the durability of gold and silver wires, comprising:

[0006] Foaming primer for foaming coatings;

[0007] Atomized transition coating liquid used for atomizing coatings;

[0008] The long-lasting protective coating includes at least a compounded polymer resin emulsion, mesoporous silica loaded with benzotriazole, and epoxy-modified barium sulfate, wherein the compounded polymer resin emulsion is a compounded mixture of carboxyacrylate emulsion, N-hydroxymethylacrylamide, polyvinyl alcohol, and polyurethane emulsion.

[0009] The coating liquid system provided by this solution to improve the durability of polyester metallic yarn consists of three parts: a foaming primer, an atomizing transition coating, and a long-lasting protective coating. The three parts work in a gradient and synergistic way, which can be precisely adapted to the industrial mass production process of polyester metallic yarn and solve the industry pain point that the exposed cross-section cannot be effectively protected after slitting.

[0010] Regarding the foamed primer in the coating liquid system for improving the durability of gold and silver wire, the foamed primer is the base sealing component of the coating liquid system for improving the durability of gold and silver wire. Its core function is to achieve precise wetting and initial adhesion of the exposed micron-level cross-section of the gold and silver wire after slitting through the foaming process. While forming a base protective layer at the cross-section, it avoids excessive accumulation of coating on the front and back planes of the gold and silver wire, thus solving the problem of excessive wire dimensional accuracy caused by subsequent coating from the source.

[0011] Specifically, the foaming primer in this solution includes starch, polyvinyl alcohol, succinic acid, and a high-foaming surfactant. The high-foaming surfactant is used to generate stable and fine foam, starch is used to thicken and stabilize the foam, polyvinyl alcohol is used to act as an adhesive to improve the coating strength of the foaming primer on the cut surface of the gold and silver wires, and succinic acid is used to adjust the pH value to reduce the acid and alkali corrosion on the cut surface of the gold and silver wires.

[0012] In some embodiments, the pH value of the foaming primer is controlled at 6.5 to 8.

[0013] In some embodiments, the foaming primer comprises 6-12 parts starch, 3-7 parts polyvinyl alcohol, 0.2-1 part succinic acid, 5-7.5 parts high-foaming surfactant, and the balance water, based on a total amount of 100 parts.

[0014] Furthermore, the foamed primer further includes a penetration enhancer and a leveling agent to improve the penetration of the foamed primer and the smoothness of the formed coating.

[0015] In some embodiments, the foaming primer comprises 6-12 parts starch, 3-7 parts polyvinyl alcohol, 0.2-1 part succinic acid, 5-7.5 parts high-foaming surfactant, 0.5-1 part penetration enhancer, 1-2 parts leveling agent, and the balance being water, based on a total amount of 100 parts.

[0016] In some embodiments, the high-foaming surfactant is selected from one or a combination of sodium dodecyl sulfonate, sodium dodecyl sulfate, ammonium stearate, sodium stearate, and lithium stearate.

[0017] In some embodiments, the penetration enhancer is selected from one or a combination of sodium diisooctyl succinate sulfonate, sodium dibutylnaphthalene sulfonate, sodium fatty alcohol ether sulfate, and phenoxylate O.

[0018] In some embodiments, the leveling agent is selected from one or a combination of polyether-modified silicone oil, polydimethylsiloxane, aryl-modified organosilicon, and acrylate leveling agents.

[0019] The foaming primer in this solution is applied to the cut cross-section of gold and silver wire through foaming and then rapidly dried at 90~100 ℃ to form a primer layer. The core is to utilize the characteristics of increased porosity and decreased density after the foaming primer forms a film, so that the resulting primer layer is lightweight and soft to the touch, which can effectively improve the problem of burrs on the cross-section and achieve preliminary sealing and protection of the exposed cross-section.

[0020] Regarding the atomized transition coating liquid in the coating liquid system for improving the durability of gold and silver wire, the atomized transition coating liquid is the interlayer bridging component of the system. Its core function is to achieve ultra-thin and uniform film formation through spraying process, connect the base coating and the top coating, solve the problem of insufficient interfacial adhesion between multiple heterogeneous coatings, and prevent the coating from falling off during subsequent bending and friction processing.

[0021] Specifically, the atomized transition coating solution in this solution includes polyethyleneimine, ethylene glycol, and polyvinylpyrrolidone. Polyethyleneimine serves to build molecular-level bridging bonds between the hydrophilic system of the base coating and the hydrophobic resin system of the top coating, while also enhancing the wetting and anchoring of the multi-layered heterogeneous cross-sections after the gold and silver wires are slit. Polyvinylpyrrolidone is the core component for film formation synergy, primarily ensuring the uniformity and integrity of the ultrathin film formed under spraying technology, while also optimizing coating flexibility and further strengthening interlayer adhesion. Ethylene glycol, as a process adaptation and film formation guarantee component, is primarily used to regulate the system's evaporation rate and reduce the film formation temperature. These three components work synergistically to achieve a crucial interlayer bridging effect, providing key support for the long-term stability of the entire gradient protection system.

[0022] In some embodiments, 100 parts of the atomized transition coating liquid include 3-7 parts of polyethyleneimine, 2-5 parts of ethylene glycol, 1-3 parts of polyvinylpyrrolidone, and the balance being water.

[0023] Furthermore, the atomized transition coating liquid of this solution is applied to the base coating on the slit cross-section of the gold and silver wires via spraying, and is rapidly dried at 90~100 ℃ to form a transition coating. It plays a key role in bridging the layers, solving the core pain point of poor interfacial compatibility and easy delamination between the hydrophilic system of the base coating and the hydrophobic resin system of the subsequent top coating. It also maintains the dimensional accuracy of the gold and silver wires with an ultra-thin, non-aggregated film formation effect, while strengthening the cross-section sealing protection and optimizing the film formation substrate of the top coating. Moreover, the drying process is matched with the previous process and is suitable for the rhythm of continuous industrial production, providing key support for the long-term stability of the entire three-gradient protection system.

[0024] The long-lasting protective coating in this solution is the core final protective unit of the three-gradient coating system. It can completely block the corrosion penetration channels of the gold and silver wire cut sections with a dense three-dimensional network film formed by compound polymer resin, eliminating the fading and loss of gloss caused by electrochemical corrosion at the source. It can also achieve intelligent self-repair and active protection under micro-damage of the coating through mesoporous silica loaded with benzotriazole. The epoxy-modified barium sulfate enhances the hydrophobicity and mechanical resistance of the coating, while fully preserving the metallic decorative luster of the gold and silver wire and the soft feel suitable for textiles. It can form a strong integrated protective system with the preceding primer and transition coating, fundamentally improving the long-lasting durability and stability of the gold and silver wire under various working conditions.

[0025] Specifically, the compound polymer resin emulsion of this long-lasting protective coating is a compound mixture of carboxyacrylate emulsion, N-hydroxymethylacrylamide, polyvinyl alcohol solution, and polyurethane solution. Among them, carboxyacrylate emulsion is a resin that can be cross-linked by an external cross-linking agent, with strong film-forming properties and high transparency; N-hydroxymethylacrylamide is a self-cross-linking resin, which helps to improve the adhesion of the coating; polyvinyl alcohol has good hydrophilicity and good film-forming properties, which can improve the wettability of the polymer resin emulsion and enhance the film-forming effect.

[0026] In some embodiments, based on 100 parts of carboxyacrylate emulsion, 3-7 parts of N-hydroxymethylacrylamide, 8-15 parts of polyvinyl alcohol solution, and 10-30 parts of polyurethane emulsion are added to the carboxyacrylate emulsion, and stirred evenly to obtain a compound polymer resin emulsion.

[0027] In some embodiments, the concentration of the polyvinyl alcohol solution is 8%.

[0028] This long-lasting protective coating contains benzotriazole-loaded mesoporous silica, which encapsulates the benzotriazole corrosion inhibitor through the nanopores of the mesoporous silica. This solves the problems of pure corrosion inhibitors being prone to loss during high-temperature curing and precipitation during long-term use. Furthermore, it can intelligently release the corrosion inhibitor when the coating is subjected to micro-damage by mechanical forces. The mesoporous silica will intelligently release the benzotriazole corrosion inhibitor from the pores in response to environmental stimuli and quickly form a chemical passivation layer, providing excellent active protection without damaging the metallic decorative luster of the gold and silver wires, thus providing long-lasting and stable anti-corrosion protection for the gold and silver wires.

[0029] In some embodiments, the mesoporous silica in the benzotriazole-loaded mesoporous silica is a mesoporous filler, and the benzotriazole is a corrosion inhibitor.

[0030] Furthermore, the particle size of mesoporous silica is 100-200 nm.

[0031] In some embodiments, mesoporous silica with a particle size of 100-200 nm is placed in a saturated ethanol solution containing benzotriazole. Through a cycle of repeated vacuuming and restoration to normal pressure, benzotriazole is forced into the nanopores using capillary pressure. After drying, mesoporous silica loaded with benzotriazole is obtained.

[0032] Furthermore, the dried mesoporous silica was completely immersed in a saturated ethanol solution of benzotriazole, and the vacuum was slowly evacuated until the degree of vacuum was ≤ At 0.09 MPa, maintain for 15-20 min, slowly introduce air, restore to normal pressure, cycle 3 times, and then dry at 60 degrees Celsius for 24 h to obtain mesoporous silica loaded with benzotriazole.

[0033] The epoxy-modified barium sulfate in this long-lasting protective coating is a nanoscale functional filler that has undergone two-step silane coupling agent directional modification. Its core functions are: firstly, the modified nanoparticles are uniformly deposited in the coating to construct a rough interface at the micro-nano scale, significantly improving the hydrophobicity of the coating and reducing the adhesion and penetration of moisture and corrosive media from the source, thus building a solid passive anti-corrosion barrier; secondly, thanks to the epoxy active groups grafted on the surface, it forms chemical bonds with the topcoat compound resin system, which not only solves the pain points of poor compatibility and easy agglomeration and sedimentation of ordinary barium sulfate with water-based resin, but also improves the coating crosslinking density, interfacial adhesion, and wear resistance and bending resistance, resisting the coating damage caused by repeated bending and friction in the downstream textile processing of gold and silver threads. At the same time, its excellent dispersibility will not destroy the high transparency of the coating, will not affect the metallic decorative luster of the gold and silver threads, and can also work with intelligent corrosion inhibitors to extend the protection cycle and improve the coating's washability, weather resistance and protection stability throughout its entire life cycle.

[0034] In some embodiments, the epoxy-modified barium sulfate is barium sulfate modified with silane coupling agents KH-550 and KH-560.

[0035] In some embodiments, the amount of silane coupling agents KH-550 and KH-560 added is 1% of the mass of barium sulfate.

[0036] In some embodiments, the size of epoxy-modified barium sulfate is controlled at 100-200 nm to construct a rough interface at the micro-nano scale, which can significantly improve hydrophobicity based on the Cassie-Baxter model.

[0037] In some embodiments, barium sulfate is added to an acidic alcohol-water system containing silane coupling agent KH-550 for hydrolysis and isothermal stirring reaction. After centrifugation, washing, drying and grinding, a modified barium sulfate intermediate is obtained. Subsequently, the modified barium sulfate intermediate is added again to a hydrolysis system containing silane coupling agent KH-560 for a secondary modification reaction to obtain epoxy-modified barium sulfate.

[0038] Furthermore, the prepared epoxy-modified barium sulfate was subjected to sand milling in a sand mill.

[0039] In some embodiments, the acidic alcohol-water system contains ethanol and water, wherein the volume ratio of ethanol to water is 9:1, and the pH is adjusted to 3.0-3.5 using an acid solution. Silane coupling agents require hydrolysis under acidic conditions, hence the acidic pH. Ethanol slows down the hydrolysis rate, facilitating the reaction of the resulting active groups with barium sulfate and reducing reactions between the active groups. Furthermore, water is required for hydrolysis, so it is added.

[0040] In some embodiments, the conditions for hydrolysis and isothermal stirring reaction are as follows: hydrolysis time is 30-60 min, water bath reaction temperature is 50-60 ℃, and isothermal stirring time is 2-3 h; centrifugation speed is 4000 r / min and time is 10 min; and vacuum drying conditions are drying at 80 ℃ for 6-8 h.

[0041] Preferably, the long-lasting protective coating also includes any one or a combination of adhesion promoters, fluorocarbon surfactants, penetration enhancers, leveling agents, crosslinking agents, softeners, and deionized water.

[0042] In some embodiments, the adhesion promoter is selected from one or a combination of γ-(2,3-epoxypropoxy)propyltrimethoxysilane (KH-560).

[0043] In some embodiments, the fluorocarbon surfactant is selected from one or a combination of perfluoroalkyl polyoxyethylene ethers.

[0044] In some embodiments, the penetration enhancer is one of ethanol or isopropanol, the leveling agent is one of polyether-modified dimethylsiloxane or polyether-modified trimethylsiloxane, the crosslinking agent is one of aziridine or polycarbodiimide, and the softener is a nonionic silicone softener.

[0045] Furthermore, based on a total mass of 100 parts for the long-lasting protective coating, the long-lasting protective coating also includes 1-2 parts of adhesion promoter, 1 part of fluorocarbon surfactant, 20-30 parts of penetration aid, 0.5-1 part of leveling agent, 0.5-1 part of crosslinking agent, 0.5-1 part of softener, and 1-2 parts of deionized water.

[0046] Secondly, this solution provides an application method for a coating liquid system that enhances the durability of gold and silver wires, used to coat and protect the cut sections of gold and silver wires.

[0047] Specifically, this solution provides a method for improving the durability of the slit cross-section of gold and silver wire, including the following steps:

[0048] A foamed primer is applied to the cut section of a gold or silver wire through foaming and then rapidly dried at a first high temperature to obtain a primer layer.

[0049] The transition coating is obtained by spraying an atomized transition coating liquid onto the base coating and then rapidly drying it at a second high temperature.

[0050] The long-lasting protective coating is applied to the transition coating by immersion and then rapidly dried at a third high temperature to obtain the topcoat.

[0051] In some embodiments, the foaming primer is stirred at high speed to incorporate air into the slurry, forming a stable and fine foam, and then the foamed primer is applied to the cut section of the gold and silver wire.

[0052] In some embodiments, the first temperature is 90~100°C.

[0053] In some embodiments, the second temperature is 90~100°C.

[0054] In some embodiments, the third temperature is 130~135°C.

[0055] It should be noted that the coating thickness on the cut section of the gold and silver wire after treatment with the coating liquid system of this scheme is no more than 16.5μm.

[0056] The main contributions and innovations of this invention are as follows:

[0057] This application provides a coating liquid system to improve the durability of gold and silver wire. This coating liquid system can accurately wet and adhere to the cross-section exposed by slitting, avoiding corrosion of the aluminum coating at the cross-section by acid and alkali liquids. It cleverly solves the problem that the cross-section formed by the slitting process of gold and silver wire cannot be protected, and significantly improves the stability of gold and silver wire in harsh environments.

[0058] Details of one or more embodiments of this application are set forth in the following drawings and description to make other features, objects and advantages of this application more readily apparent. Attached Figure Description

[0059] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments of this application and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0060] Figure 1 Yes, this is a schematic diagram of the cut cross-section of untreated gold and silver wire.

[0061] Figure 2 This is a schematic diagram of the cut cross-section of the gold and silver wire treated with the coating liquid system in Example 1.

[0062] Figure 3 It is a diagram of the morphology of gold and silver threads, among which... Figure 3 (a1) in the figure represents the surface morphology of the untreated gold and silver wire. Figure 3 (a2) in the figure shows the cross-sectional morphology of the untreated gold and silver wire. Figure 3 The surface morphology of the gold and silver wires treated with the coating liquid system in Example (b1) of the present invention is shown below. Figure 3 (b2) in Example 1 shows the cross-sectional morphology of the gold and silver wire treated with the coating liquid system.

[0063] Figure 4 These are photos of actual gold and silver wire artifacts, including... Figure 4 (a) in the figure is a photograph of the original sample in Comparative Example 1 and its front and back sides after being treated with alkaline solution. Figure 4 (b) in Example 1 shows the sample of the protective coating and its front and back photographs after being treated with an alkaline solution.

[0064] Figure 5 It is a proportional topographic diagram, in which Figure 5 (c1) in Comparative Example 2 shows the cross-sectional morphology of the unprotected gold and silver wire after treatment with an alkaline solution. Figure 5 (c2) is a cross-sectional FE-SEM image of the protective coating sample in Example 2 after treatment with an alkaline solution. Figure 5 (d1) and (d2) are TEM images of the gold and silver wire coating liquid at different magnifications. Detailed Implementation

[0065] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with one or more embodiments of this specification. Rather, they are merely examples of apparatuses and methods consistent with some aspects of one or more embodiments of this specification as detailed in the appended claims.

[0066] It should be noted that the steps of the corresponding methods are not necessarily performed in the order shown and described in this specification in other embodiments. In some other embodiments, the methods may include more or fewer steps than described in this specification. Furthermore, a single step described in this specification may be broken down into multiple steps in other embodiments; and multiple steps described in this specification may be combined into a single step in other embodiments.

[0067] Example 1:

[0068] This embodiment provides a coating liquid system for improving the durability of gold and silver wires and its application method. The specific formula and process are as follows:

[0069] (1) Preparation of foaming primer: By mass, take 8 parts starch, 5 parts polyvinyl alcohol, 0.5 parts succinic acid, 6 parts sodium dodecyl sulfate (high foaming surfactant), 0.8 parts sodium diisooctyl succinate sulfonate (penetration aid), and 1.5 parts polyether modified silicone oil (leveling agent), add 78.2 parts deionized water, stir evenly, and adjust the pH to 7.0 with succinic acid to obtain foaming primer. When using, place the obtained primer in a high-speed mixer, stir and aerate at 2000 rpm for 10 minutes to form stable and delicate foam, immediately coat it on the cut section of gold and silver wire, and dry it quickly at 95℃ to form the primer layer.

[0070] (2) Preparation of atomized transition coating: By mass, take 5 parts of polyethyleneimine, 3 parts of ethylene glycol, and 2 parts of polyvinylpyrrolidone, add 90 parts of deionized water, stir and dissolve evenly to obtain atomized transition coating. The above coating is evenly sprayed onto the cross-section of the gold and silver wire covered with the base coating through a spraying device. The spraying pressure is 0.2 MPa, and the spraying amount is controlled to a wet film thickness of about 5 μm. It is then rapidly dried at 95℃ to form a transition coating.

[0071] (3) Preparation of long-lasting protective coating: First, prepare the compound polymer resin emulsion by taking 100 parts of carboxyacrylate emulsion, adding 5 parts of N-hydroxymethylacrylamide, 10 parts of 8% polyvinyl alcohol solution and 20 parts of polyurethane emulsion in sequence, stirring and mixing evenly to obtain the compound polymer resin emulsion.

[0072] Next, the mesoporous silica loaded with benzotriazole was prepared by immersing 150 nm mesoporous silica particles completely in a saturated ethanol solution of benzotriazole. The solution was then slowly evacuated to a vacuum level ≤ -0.09 MPa and maintained for 20 minutes. Air was then slowly introduced to restore atmospheric pressure, and this cycle was repeated three times. The solid was then removed and vacuum-dried at 60 °C for 24 hours to obtain the mesoporous silica loaded with benzotriazole.

[0073] Secondly, in the preparation of epoxy-modified barium sulfate, barium sulfate with a particle size of 150 nm was added to a mixed solvent of ethanol and water at a volume ratio of 9:1. The pH was adjusted to 3.2 with acid, and 1% (by weight of barium sulfate) of silane coupling agent KH-550 was added. The reaction was carried out at 55°C for 45 minutes, followed by constant temperature stirring for 2.5 hours. The reaction solution was centrifuged at 4000 r / min for 10 minutes, washed, and then vacuum dried at 80°C for 7 hours to obtain the modified barium sulfate intermediate. The intermediate was redispersed in a hydrolysis system containing silane coupling agent KH-560 (added at 1% (by weight of barium sulfate)) and a second modification reaction was carried out under the same conditions. The product was centrifuged, washed, dried, and then milled in a sand mill until the particle size was uniform to obtain epoxy-modified barium sulfate.

[0074] Finally, the long-lasting protective coating is prepared by taking 50 parts of the compound polymer resin emulsion obtained in step (1), 4 parts of the benzotriazole-loaded mesoporous silica obtained in step (2), 4 parts of the epoxy-modified barium sulfate obtained in step (3), and then adding 1.5 parts of adhesive accelerator KH-560, 1 part of perfluoroalkyl polyoxyethylene ether (fluorocarbon surfactant), 25 parts of isopropanol (penetration aid), 0.8 parts of polyether-modified dimethylsiloxane (leveling agent), 0.7 parts of aziridine (crosslinking agent), 0.8 parts of nonionic silicone softener, and 12.2 parts of deionized water. The mixture is stirred and dispersed evenly to obtain the long-lasting protective coating.

[0075] (4) Coating protection of the cut section of gold and silver wire

[0076] The gold and silver wires, which had been coated with a base coat and a transition coat in sequence, were immersed in the aforementioned long-lasting protective coating solution for 5 seconds. After removal, they were rapidly dried at 132°C to form a top coat. Ultimately, the total thickness of the three coating layers on the cut cross-section of the gold and silver wires was 15.2 μm, which meets the requirement of not exceeding 16.5 μm.

[0077] In this embodiment, the gold and silver wires treated with the coating system were immersed in a 10 g / L sodium carbonate alkaline solution for 60 min, and the metallic decorative gloss of their cut cross-sections was observed and characterized by SEM testing.

[0078] The FESEM image of the gold and silver wires prepared in Example 1 with coating liquid protection is shown below. Figure 3 As shown in (b1) and (b2), the protective liquid has completely and uniformly coated the gold and silver wires, and the protective coating on the gold and silver wires forms a continuous film, which can play a good protective role.

[0079] Comparative Example 1:

[0080] The coating protection process for the cut cross-section of the gold and silver wire in Example 1 was removed, while the remaining components and processes remained unchanged. The uncoated gold and silver wire from this comparative example was immersed in a 10 g / L sodium carbonate alkaline solution for 60 min, and the metallic decorative luster of its cut cross-section was observed.

[0081] like Figure 3 As shown in (a2), the gold and silver wires in Comparative Example 1 have a typical four-layer structure, compared to Figure 3 In Example 1 of (b2), the cut surface of the gold and silver wires has obvious coating, indicating that the protective liquid has completely and uniformly coated the gold and silver wires, and that the protective coating has a uniform and continuous film-forming effect on the gold and silver wires with good adhesion.

[0082] like Figure 4 As can be seen from the dashed line in (a), the original coating in Comparative Example 1 peeled off and lost its metallic luster, while Figure 4 As shown in (b), the gold and silver wires with protective coatings retain their structure and color and luster after alkali treatment, with no obvious coating separation or peeling. This is because the protective coating has high film density and a more compact molecular chain arrangement, thereby increasing cohesion and coating density, leading to the release of water molecules and OH groups. - The coating is difficult to penetrate, thus improving the alkali resistance of gold and silver wire.

[0083] Example 2:

[0084] This embodiment provides another coating liquid system for improving the durability of gold and silver wires and its application method. Compared with Embodiment 1, this embodiment adjusts the component ratios of each coating, some raw material types, and process parameters, as follows:

[0085] (1) Preparation of foaming primer

[0086] By weight, take 10 parts starch, 4 parts polyvinyl alcohol, 0.8 parts succinic acid, 7 parts a compound of sodium dodecyl sulfonate and ammonium stearate (mass ratio 1:1, as a high-foaming surfactant), 0.6 parts sodium dibutylnaphthalene sulfonate (penetration aid), and 1.2 parts polydimethylsiloxane (leveling agent), add 76.4 parts deionized water, stir evenly, and adjust the pH to 7.5 with succinic acid to obtain a foaming primer. When using, place the obtained primer in a high-speed mixer and aerate at 1800 rpm for 12 minutes to form a fine and stable foam. Immediately coat the foam onto the slit section of the gold and silver wire, and quickly dry at 92℃ to form the base layer.

[0087] (2) Preparation of atomized transition coating liquid

[0088] By weight, 4 parts polyethyleneimine, 4 parts ethylene glycol, and 1.5 parts polyvinylpyrrolidone were added to 90.5 parts deionized water and stirred until uniformly dissolved to prepare an atomized transition coating. The coating was then uniformly sprayed onto the cross-section of the gold and silver wires already coated with the base layer using a spraying device. The spraying pressure was 0.18 MPa, and the spraying amount was controlled to a wet film thickness of approximately 4 μm. The coating was then rapidly dried at 92°C to form the transition coating.

[0089] (3) Preparation of long-lasting protective coating

[0090] First, the preparation of the compounded polymer resin emulsion. Take 100 parts of carboxyacrylate emulsion, add 4 parts of N-hydroxymethylacrylamide, 12 parts of 8% polyvinyl alcohol solution, and 15 parts of polyurethane emulsion in sequence, stir and mix evenly to obtain the compounded polymer resin emulsion.

[0091] Next, the preparation of benzotriazole-loaded mesoporous silica was carried out. Mesoporous silica particles with a diameter of 120 nm were completely immersed in a saturated ethanol solution of benzotriazole. A vacuum was slowly drawn to a pressure ≤ -0.09 MPa and maintained for 15 minutes. Then, air was slowly introduced to restore atmospheric pressure. This cycle was repeated four times. The solid was removed and vacuum-dried at 60 °C for 22 hours to obtain benzotriazole-loaded mesoporous silica.

[0092] Secondly, the preparation of epoxy-modified barium sulfate. Barium sulfate with a particle size of 120 nm was added to a mixed solvent of ethanol and water in a volume ratio of 9:1. The pH was adjusted to 3.0 with acid, and 1% (by weight of barium sulfate) of silane coupling agent KH-550 was added. The reaction was carried out at 52 °C for 50 minutes, followed by constant temperature stirring for 2 hours. The reaction solution was centrifuged at 4000 r / min for 10 minutes, washed, and then vacuum dried at 80 °C for 6 hours to obtain a modified barium sulfate intermediate. The intermediate was redispersed in a hydrolysis system containing silane coupling agent KH-560 (added at 1.2% by weight of barium sulfate), and a second modification reaction was carried out under the same conditions. The product was centrifuged, washed, dried, and then milled in a sand mill until the particle size was uniform to obtain epoxy-modified barium sulfate.

[0093] Finally, the long-lasting protective coating solution was prepared. By weight, 60 parts of the prepared compound polymer resin emulsion, 3 parts of the prepared benzotriazole-loaded mesoporous silica, and 5 parts of the prepared epoxy-modified barium sulfate were added. Then, 1 part of the adhesion promoter KH-560, 1 part of the perfluoroalkyl polyoxyethylene ether (fluorocarbon surfactant), 22 parts of ethanol (penetration aid), 0.6 parts of polyether-modified trimethylsiloxane (leveling agent), 0.8 parts of polycarbodiimide (crosslinking agent), 0.6 parts of nonionic silicone softener, and 6 parts of deionized water were thoroughly stirred and dispersed to obtain the long-lasting protective coating solution.

[0094] (4) Coating protection of the cut section of gold and silver wire

[0095] The gold and silver wires, which had been coated with a base coat and a transition coat in sequence, were immersed in the aforementioned long-lasting protective coating solution for 8 seconds. After removal, they were rapidly dried at 130°C to form a top coat. Ultimately, the total thickness of the three coating layers on the cut cross-section of the gold and silver wires was 14.8 μm, which meets the requirement of not exceeding 16.5 μm.

[0096] In this embodiment, the gold and silver wires treated with the coating system were immersed in a 20 g / L sodium carbonate alkaline solution for 90 min, and then characterized by SEM testing. The results are as follows: Figure 5 As shown in (c2) in the figure, the cut cross-section of the gold and silver wire forms a dense protective coating. The coating structure is continuous and has no obvious cracks or gaps, which can effectively protect the internal aluminum coating and prevent loss of luster. Figure 5 (d1) and (d2) are TEM images of the coating emulsion at different magnifications. The emulsion particles in the images exhibit an irregular spherical structure, and there is some adhesion between the emulsion particles. This is because a silane coupling agent is introduced into the system. During the hydrolysis of the siloxane, hydroxyl polymers are generated, and some terminal hydroxyl groups undergo further condensation reactions. This is beneficial for the formation of a dense and continuous film structure in the coating, thereby improving the protective effect.

[0097] Comparative Example 2:

[0098] The coating protection process for the cut section of the gold and silver wire in Example 2 was removed, while the remaining components and processes remained unchanged. The gold and silver wire treated with the coating system in this example was immersed in a 20 g / L sodium carbonate alkaline solution for 90 min and characterized by SEM testing. The results are as follows: Figure 5 As shown in (c1) in the figure, the cut section of the gold and silver wire is exposed and there are obvious gaps and cracks in the coating. Alkali solution can easily penetrate into the gaps and cracks between the coatings, causing corrosion and peeling of the aluminum coating.

[0099] Those skilled in the art should understand that the technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments have been described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0100] The above embodiments are merely illustrative of several implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A coating liquid system for improving the durability of gold and silver wires, characterized in that, include: Foaming primer, wherein the foaming primer includes starch, polyvinyl alcohol, succinic acid and high foaming surfactant; Atomized transition coating liquid, wherein the atomized transition coating liquid includes polyethyleneimine, ethylene glycol and polyvinylpyrrolidone; The long-lasting protective coating includes at least a compounded polymer resin emulsion, mesoporous silica loaded with benzotriazole, and epoxy-modified barium sulfate, wherein the compounded polymer resin emulsion is a compounded mixture of carboxyacrylate emulsion, N-hydroxymethylacrylamide, polyvinyl alcohol, and polyurethane emulsion.

2. The coating liquid system for improving the durability of gold and silver wires according to claim 1, characterized in that, In mesoporous silica loaded with benzotriazole, the mesoporous silica serves as a mesoporous filler, and the benzotriazole serves as a corrosion inhibitor. The particle size of the mesoporous silica is 100-200 nm.

3. The coating liquid system for improving the durability of gold and silver wires according to claim 1, characterized in that, Epoxy-modified barium sulfate is barium sulfate modified with silane coupling agents KH-550 and KH-560.

4. The coating liquid system for improving the durability of gold and silver wires according to claim 1, characterized in that, Foaming primers further include penetration enhancers and leveling agents.

5. The coating liquid system for improving the durability of gold and silver wires according to claim 1, characterized in that, Mesoporous silica was placed in a saturated ethanol solution containing benzotriazole. Through repeated cycles of vacuuming and restoring atmospheric pressure, benzotriazole was forced into the nanopores using capillary pressure. After drying, mesoporous silica loaded with benzotriazole was obtained.

6. The coating liquid system for improving the durability of gold and silver wires according to claim 1, characterized in that, Barium sulfate was added to an acidic alcohol-water system containing silane coupling agent KH-550 for hydrolysis and constant-temperature stirring reaction. After centrifugation, washing, drying and grinding, a modified barium sulfate intermediate was obtained. Subsequently, the modified barium sulfate intermediate was added again to a hydrolysis system containing silane coupling agent KH-560 for a secondary modification reaction to obtain epoxy-modified barium sulfate.

7. An application method based on the coating liquid system for improving the durability of gold and silver wires as described in any one of claims 1 to 6, characterized in that, It is used for coating protection of the cut sections of gold and silver wires.

8. The application method of the coating liquid system for improving the durability of gold and silver wires according to claim 7, characterized in that, Includes the following steps: A foamed primer is applied to the cut section of a gold or silver wire through foaming and then rapidly dried at a first high temperature to obtain a primer layer. The transition coating is obtained by spraying an atomized transition coating liquid onto the base coating and then rapidly drying it at a second high temperature. The long-lasting protective coating is applied to the transition coating by immersion and then rapidly dried at a third high temperature to obtain the topcoat.

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