Brush-plated silver alloy plating solution for repairing silver-plated layer of open-type disconnector and preparation method thereof

Abstract

The invention discloses a brush-plated silver alloy plating solution for repairing the silver-plated layer of an open-type disconnector. The plating solution comprises the following components: 30-75 g / L of a silver salt, 10-50 g / L of a compound containing a ureide structure, 10-30 g / L of a sodium salt of a cytosine nucleotide, 40-100 g / L of a compound containing a succinimide structure, 0.1-2 g / L of an additive, 0-5 g / L of potassium antimony tartrate, 10-20 g / L of a dispersant, and 5-30 g / L of a conductive salt. The compound containing a ureide structure is selected from 5,6-dihydrouracil, L-hydroorotic acid, 5-methyl-5-phenylhydantoin, 5-methylimidazolidine-2,4-dione, or 5-(4-hydroxyphenyl)imidazolidine-2,4-dione.

Description

Technical Field

[0001] The invention belongs to the technical field of plating solutions, and in particular relates to a brush-plated silver alloy plating solution for repairing a silver-plated layer of an open-type disconnector and a preparation method thereof. Background Art

[0002] The statements herein merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Open-type disconnectors are a common type of high-voltage electrical equipment, widely used in primary power grid equipment. Because these components operate in atmospheric environments, the electrical contact parts must possess both excellent electrical conductivity and atmospheric corrosion resistance. To achieve this, the copper contacts are electroplated with silver for protection. Current supervisory regulations require that the silver plating thickness of disconnectors reach 20μm. However, actual operating experience shows that the silver plating on open-type disconnector contacts is often damaged by wear, corrosion, and arc erosion, resulting in surface defects on the contacts and, in turn, faults such as overheating and arcing.

[0004] Existing technical solutions mainly involve coating the contact surface with conductive paste or replacing the entire part. However, this approach has the disadvantages of high maintenance costs, long construction cycles, and difficulty meeting on-site maintenance needs.

[0005] Brush plating is a high-quality, efficient coating preparation technology based on the principles of electroplating. Through the rational formulation of the plating solution, surface pretreatment, and the selection of appropriate brush plating process parameters, it can deposit silver, copper, tin, and other coatings on various metal components. This technology offers the advantages of field application, high coating density, high bonding strength, and compatibility with a wide range of materials. Furthermore, this technology is not restricted by component shape or structure and can be used on components with flat or rotating surfaces. It holds great promise for the repair of silver plating on open-type disconnector contacts.

[0006] At present, the silver plating solution used in brush plating has the following problems:

[0007] 1. The silver plating layer is not hard enough, resulting in a service life that cannot meet the application requirements of the disconnector under wear scenarios;

[0008] 2. The bonding strength of the silver plating layer is not enough, which causes the silver plating layer to peel off during the application process;

[0009] 3. The deposition efficiency of the silver plating layer is low, which makes it difficult to meet the short cycle requirements required during maintenance;

[0010] 4. It is difficult to alloy the silver plating layer. Since the potential of silver is very different from that of other common alloying elements, it is difficult to improve the performance of the plating layer by electroplating co-deposition. Summary of the Invention

[0011] In view of the shortcomings of the prior art, the present invention aims to provide a brush-plated silver alloy plating solution for repairing the silver-plated layer of an open-type disconnector and a preparation method thereof.

[0012] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0013] In a first aspect, the present invention provides a brush-plated silver alloy plating solution for repairing the silver-plated layer of an open-type disconnector, comprising the following components: 30-75 g / L of silver salt, 10-50 g / L of a compound containing a ureide structure, 10-30 g / L of a sodium salt of cytosine nucleotide, 40-100 g / L of a compound containing a succinimide structure, 0.1-2 g / L of an additive, 0-5 g / L of potassium antimony tartrate, 10-20 g / L of a dispersant, and 5-50 g / L of a conductive salt;

[0014] The compound containing an ureide structure is selected from 5,6-dihydrouracil, L-hydroorotic acid, 5-methyl-5-phenylhydantoin, 5-methylimidazolidine-2,4-dione or 5-(4-hydroxyphenyl)imidazolidine-2,4-dione;

[0015] The cytosine nucleotide sodium salt is selected from cytidine-5'-triphosphate sodium salt, cytidine-5'-diphosphate sodium salt, cytidine-5'-monophosphate sodium salt, 2'-deoxycytidine 5'-triphosphate sodium salt, 2'-deoxycytidine 5'-diphosphate sodium salt or 2'-deoxycytidine 5'-monophosphate sodium salt;

[0016] The compound containing a succinimide structure is selected from maleimide, succinimide, 4-aminophthalimide or 1,2-cyclohexanedicarboximide.

[0017] Compounds with a succinimide structure are commonly used as silver ion ligands in electroplating solutions. The imine structure in the molecular structure can react with silver ions under alkaline conditions to form a complex ion, resulting in a coating with performance similar to that of cyanide. However, compounds containing a succinimide structure are easily hydrolyzed under alkaline conditions, and the resulting coating is quite brittle. Therefore, it is necessary to introduce ligands with different structures, such as compounds containing a ureide structure, to adjust the kinetic parameters of the electrode reaction to obtain a coating with excellent performance.

[0018] The compounds containing ureide structure are similar to the compounds containing succinimide structure in molecular structure. Both have an imine structure that can coordinate with silver ions. They are not easily hydrolyzed under alkaline conditions, which is conducive to obtaining a mirror-bright silver plating layer.

[0019] Sodium salt of cytosine nucleotide is a multifunctional chelating agent. Both the phosphate and cytosine structural units in its molecular structure can participate in the coordination of metal ions. The phosphate unit has a good emulsifying and dispersing effect, which can effectively inhibit the metal ions in the solution from forming insoluble solids on the surface of the product, preventing burrs, pinholes, roughness and poor results in the coating. The cytosine unit participates in the coordination of silver ions through the N atom in the six-membered ring, and can form a binary complex consisting of two cytosine units and a silver ion.

[0020] At present, some theories and practices have proved that compared with single-ligand electroplating solutions, electroplating solutions containing multiple ligand combinations are more likely to obtain bright coatings with good binding force and fine crystals. The electroplating solution of the present invention contains multiple ligands such as ureide-structured compounds, succinimide-structured compounds, and sodium salt of cytosine nucleotide. In addition to forming single-type ligand complexes in the system, multiple ligands can cooperate with each other based on the "coordination saturation principle", clustering effect, or association effect to form mixed ligand mixtures. For example, compounds containing ureide structures and compounds containing succinimide structures have considerable competitive ability. The two ligands can coexist in the inner boundary of metal ions to form more stable coordination-saturated mixed ligand complexes. Sodium salt of cytosine nucleotide ionizes to form stable anions, which can form multi-ion association complexes with other oppositely charged ligands through mechanisms such as electrostatic effects, ligand interactions, or hydrogen bonds. Potassium antimony tartrate, as a potassium salt containing antimony complex, cooperates with silver complex in the electroplating process to form a silver-antimony alloy coating. When the silver-antimony alloy plating process is used, a coating with high hardness, good wear resistance, fast deposition and good brightness can be obtained compared with pure silver coating.

[0021] In some embodiments, the silver salt is silver nitrate or silver methanesulfonate.

[0022] In some embodiments, the dispersant is sodium methylene dinaphthalene sulfonate. As an anionic surfactant with excellent performance, sodium methylene dinaphthalene sulfonate is easily adsorbed on the electrode surface and forms a multi-ion association complex or a multi-component mixed ligand complex with the ligand ion, thereby regulating the discharge rate of the metal ions. It can also reduce surface tension, improve the wetting effect of the solution, and quickly release hydrogen from the cathode, thereby preventing pinholes in the coating.

[0023] In some embodiments, the conductive salt is sodium carbonate, potassium carbonate, ammonium acetate, or potassium sodium tartrate.

[0024] Preferably, when the conductive salt is sodium carbonate or potassium carbonate, the concentration of sodium carbonate or potassium carbonate is 10-30 g / L;

[0025] When the conductive salt is ammonium acetate, the concentration of ammonium acetate is 10-20 g / L;

[0026] When the conductive salt is potassium sodium tartrate, the concentration of potassium sodium tartrate is 5-20 g / L.

[0027] In some embodiments, the pH value of the plating solution is 9-11.

[0028] Preferably, the pH adjuster of the plating solution is KOH. Compared with other strong bases, potassium ions produced by hydrolysis of KOH have higher ion mobility, which is beneficial for improving the conductivity of the plating solution.

[0029] In some embodiments, the additive is a mixture of 4-methyl-N-toluenesulfonylbenzenesulfonamide and sodium 3-mercapto-1-propanesulfonate, and the mass ratio of 4-methyl-N-toluenesulfonylbenzenesulfonamide to sodium 3-mercapto-1-propanesulfonate is 1.5-2.5:1.

[0030] The electron-withdrawing effect of the two sulfonyl groups in the molecular structure of 4-methyl-N-toluenesulfonylbenzenesulfonamide makes it easier for the hydrogen on the nitrogen atom to dissociate, making it soluble in alkaline solution and adsorbed by the electrode. In electroplating, it is used as a primary brightener to improve the surface smoothness of the coating.

[0031] Sodium 3-mercapto-1-propane sulfonate is a type of organic compound that is easily reduced. It can reduce the energy of metal electrodes at high current density and enhance the brightening effect of the coating.

[0032] 4-Methyl-N-toluenesulfonylbenzenesulfonamide and sodium 3-mercapto-1-propanesulfonate are adsorbed on the electrode surface based on different structures, which can synergistically regulate the kinetic parameters of the electrode reaction and improve the coating quality.

[0033] The general formula of the compound containing ureide structure is shown below:

[0034]

[0035] The molecular structure of cytosine nucleotide sodium salt consists of three parts: cytosine, pentose, and phosphate, where the R group is hydrogen or hydroxyl, and the value of n ranges from 1, 2, or 3. The general structural formula is shown below:

[0036]

[0037] The general formula of compounds containing succinimide structure is as follows

[0038]

[0039] In a second aspect, the present invention provides a method for preparing a brush-plated silver alloy plating solution for repairing the silver-plated layer of the open-type disconnector, comprising the following steps:

[0040] First, dissolve the silver salt in a small amount of deionized water to obtain solution A.

[0041] Sodium salt of cytosine nucleotide, a compound containing a succinimide structure, and a compound containing an ureide structure are sequentially placed in an appropriate amount of water for dissolution at a temperature of 30-50° C., and then potassium antimony tartrate solution is added thereto to form solution B.

[0042] The above solution A and solution B are mixed and stirred evenly, and then dispersant, conductive salt and additives are added in sequence to form solution C;

[0043] KOH was added to the above solution C to adjust the pH value of the solution to 9-11 to obtain the final solution.

[0044] The beneficial effects achieved by one or more embodiments of the present invention are as follows:

[0045] Taking into account the shortcomings of existing brush plating silver solutions, this patented solution utilizes multiple ligands that react with silver ions, particularly those with imine groups and cytosine units. This creates a synergistic effect that enhances polarization during the electrodeposition process, resulting in a dense, well-adhesive electroplated layer. By optimizing the content of silver salt and multi-component ligand, the transport rate of the ligand ions is accelerated, while the addition of additives and dispersants effectively eliminates cathodic side reactions. This results in a high deposition efficiency for the plating system, meeting the requirements for efficient on-site brush plating repair of disconnectors. Furthermore, the alloying element Sb, which has grain refinement and solid solution strengthening properties, is added to the plating solution to improve coating performance. Furthermore, through the grain refinement and solid solution strengthening effects during deposition, the coating hardness is increased by 40% compared to currently used electroplated silver layers. The coating exhibits excellent bonding strength to the substrate, exhibiting no defects such as flaking after a cross-hatch test. The deposition efficiency is high, reaching 3μm / min per pass. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0047] Figure 1 This is a photo of the coating obtained in Example 1 after cross-cutting;

[0048] Figure 2 is a SEM image of the coating prepared in Example 1;

[0049] Figure 3 This is the XRD image of the coating prepared in Example 1;

[0050] Figure 4 This is a photo of the coating obtained in Example 2 after cross-cutting;

[0051] Figure 5is a SEM image of the coating prepared in Example 2;

[0052] Figure 6 This is the XRD image of the coating prepared in Example 2;

[0053] Figure 7 This is a photo of the coating obtained in Comparative Example 1 after cross-cutting;

[0054] Figure 8 This is a photo of the coating obtained in Comparative Example 2 after cross-cutting;

[0055] Figure 9 This is the coating morphology after electroplating in Comparative Example 3. DETAILED DESCRIPTION

[0056] It should be noted that the following detailed description is illustrative and is intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0057] Example 1

[0058] Silver nitrate 50g / L, 5-methylimidazolidine-2,4-dione 20g / L, cytidine-5′-triphosphate sodium salt 10g / L, succinimide 70g / L, potassium carbonate 10g / L, sodium methylene dinaphthalenesulfonate 10g / L, ammonium acetate 15g / L, potassium sodium tartrate 5g / L, additive 1g / L, potassium hydroxide 50g / L, pH 9.5;

[0059] The additive is a mixture of 4-methyl-N-toluenesulfonylbenzenesulfonamide and sodium 3-mercapto-1-propanesulfonate, and the mass ratio of 4-methyl-N-toluenesulfonylbenzenesulfonamide to sodium 3-mercapto-1-propanesulfonate is 2:1.

[0060] The preparation method is:

[0061] First, dissolve silver nitrate in a small amount of deionized water to obtain solution A.

[0062] 5-Methylimidazolidine-2,4-dione, cytidine-5′-triphosphate sodium salt, and succinimide were sequentially added into an appropriate amount of water and dissolved at a dissolving temperature of 40° C. to form solution B.

[0063] The above-mentioned solution A and solution B are mixed and stirred evenly, and then sodium methylene dinaphthalene sulfonate, potassium carbonate, potassium sodium tartrate and additives are added to form solution C;

[0064] KOH was added to the above solution C to adjust the pH value of the solution to 10 to obtain the final solution.

[0065] Brush plating uses a DC power supply and a constant voltage mode. After the workpiece is cleaned and activated, the brush plating parameter is selected to be 2V, the relative speed between the brush plating pen and the workpiece is 6m / min, and the coating is obtained after 400s of brush plating.

[0066] The thickness of the coating is 25 μm, and the SEM of the coating is as follows Figure 2 As shown, the XRD of the coating is Figure 3 As shown. From SEM, it can be seen that the coating surface is smooth, without obvious defects, and has a fine cellular grain structure. XRD results show that the coating is composed of pure Ag phase with a face-centered cubic structure. The coating did not fall off after the cross-cut test. Figure 1 As shown, the coating hardness is 105HV.

[0067] Example 2

[0068] Silver nitrate 50g / L, 5-methylimidazolidine-2,4-dione 50g / L, 2'-deoxycytidine 5'-triphosphate sodium salt 15g / L, succinimide 80g / L, potassium carbonate 30g / L, sodium methylene dinaphthalenesulfonate 15g / L, ammonium acetate 18g / L, potassium antimony tartrate 3g / L, potassium sodium tartrate 15g / L, additive 1g / L, potassium hydroxide 70g / L, pH 9.7.

[0069] The additive is a mixture of 4-methyl-N-toluenesulfonylbenzenesulfonamide and sodium 3-mercapto-1-propanesulfonate, and the mass ratio of 4-methyl-N-toluenesulfonylbenzenesulfonamide to sodium 3-mercapto-1-propanesulfonate is 1.8:1.

[0070] The preparation method is:

[0071] First, dissolve silver nitrate in a small amount of deionized water to obtain solution A;

[0072] 5-Methylimidazolidine-2,4-dione, 2'-deoxycytidine 5'-triphosphate sodium salt, and succinimide were sequentially dissolved in an appropriate amount of water at 40°C, and then potassium antimony tartrate solution was added thereto to form solution B;

[0073] The above-mentioned solution A and solution B are mixed and stirred evenly, and then sodium methylene dinaphthalene sulfonate, potassium carbonate, potassium sodium tartrate and additives are added to form solution C;

[0074] KOH was added to the above solution C to adjust the pH value of the solution to 9.7 to obtain the final solution.

[0075] Brush plating uses a DC power supply and a constant voltage mode. After the workpiece is cleaned and activated, the brush plating parameter is selected to be 1V, the relative speed between the brush plating pen and the workpiece is 10m / min, and the coating is obtained after 400s of brush plating.

[0076] The coating thickness is 23 μm, and the SEM image of the coating is as follows: Figure 5 As shown, the XRD pattern of the coating is as follows Figure 5 As shown in the figure, the SEM morphology shows that the coating has a small cellular morphology. The addition of Sb does not change the lattice structure of the coating phase, but there is a certain diffraction peak shift compared to pure silver, indicating that the addition of Sb changes the lattice spacing and can play a role in solid solution strengthening. No peeling or other phenomena occurred after the cross-cut test. Figure 4 As shown, the coating hardness is 145HV.

[0077] Example 3

[0078] Silver methanesulfonate 30g / L, 5-(4-hydroxyphenyl)imidazolidine-2,4-dione 20g / L, cytidine-5′-monophosphate sodium salt 25g / L, 4-aminophthalimide 50g / L, sodium carbonate 10g / L, sodium methylene dinaphthalenesulfonate 15g / L, ammonium acetate 18g / L, potassium antimony tartrate 5g / L, potassium sodium tartrate 15g / L, additive 1g / L, potassium hydroxide is added to adjust the plating solution pH to 9.

[0079] The additive is a mixture of 4-methyl-N-toluenesulfonylbenzenesulfonamide and sodium 3-mercapto-1-propanesulfonate, and the mass ratio of 4-methyl-N-toluenesulfonylbenzenesulfonamide to sodium 3-mercapto-1-propanesulfonate is 2.5:1.

[0080] Example 4

[0081] Silver nitrate 75g / L, 5-(4-hydroxyphenyl)imidazolidine-2,4-dione 20g / L, 2'-deoxycytidine 5'-diphosphate sodium salt 10g / L, maleimide 100g / L, sodium carbonate 20g / L, sodium methylene dinaphthalenesulfonate 15g / L, ammonium acetate 18g / L, potassium antimony tartrate 1g / L, additive 1g / L, potassium hydroxide is added to adjust the plating solution pH to 11.

[0082] The additive is a mixture of 4-methyl-N-toluenesulfonylbenzenesulfonamide and sodium 3-mercapto-1-propanesulfonate, and the mass ratio of 4-methyl-N-toluenesulfonylbenzenesulfonamide to sodium 3-mercapto-1-propanesulfonate is 1.5:1.

[0083] Comparative Example 1

[0084] Silver nitrate 75g / L, succinimide 100g / L, potassium carbonate 30g / L, sodium methylene dinaphthalenesulfonate 30g / L, ammonium acetate 15g / L, potassium hydroxide 70g / L, pH 9.5.

[0085] Brush plating uses a DC power supply and a constant voltage mode. After the workpiece is cleaned and activated, the brush plating parameter is selected to be 2V, the relative speed between the brush plating pen and the workpiece is 6m / min, and the coating is obtained after 400s of brush plating.

[0086] The coating thickness is 17μm, and it falls off after the cross-cut test. Figure 7 As shown, the coating hardness is 85HV.

[0087] Comparative Example 2

[0088] Silver nitrate 50g / L, potassium carbonate 10g / L, 5-methylimidazolidine-2,4-dione 50g / L, succinimide 50g / L, ammonium acetate 20g / L, potassium sodium tartrate 15g / L, sodium methylene dinaphthalenesulfonate 20g / L, potassium hydroxide 70g / L, pH is 10.

[0089] Brush plating uses a DC power supply and a constant voltage mode. After the workpiece is cleaned and activated, the brush plating parameter is selected to be 2V, the relative speed between the brush plating pen and the workpiece is 6m / min, and the coating is obtained after 400s of brush plating.

[0090] The coating thickness is 13μm, and it falls off after the cross-cut test. Figure 8 As shown, the coating hardness is 76HV.

[0091] Comparative Example 3

[0092] Silver nitrate 35g / L, 5-methylimidazolidine-2,4-dione 50g / L, potassium carbonate 30g / L, ammonium acetate 15g / L, potassium hydroxide 70g / L, pH is 10.5.

[0093] Brush plating uses a DC power supply and constant voltage mode. After the workpiece is cleaned and activated, the brush plating parameters are selected to be 2V, the relative speed between the brush plating pen and the workpiece is 6m / min, and after 400s of brush plating, the coating is obtained. Figure 9 shown.

[0094] The coating thickness is 6μm, and the coating falls off immediately after plating. The coating hardness is 80HV.

[0095] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. Brush silver alloy plating solution for repairing the silver plating layer of open type disconnector, characterized by: The invention comprises the following components: 30-75 g / L of silver salt, 10-50 g / L of a compound containing an ureide structure, 10-30 g / L of sodium cytosine nucleotide, 40-100 g / L of a compound containing a succinimide structure, 0.1-2 g / L of an additive, 0-5 g / L of potassium antimony tartrate, 10-20 g / L of a dispersant, and 5-50 g / L of a conductive salt; wherein, The compound containing an ureide structure is selected from 5,6-dihydrouracil, L-hydroorotic acid, 5-methyl-5-phenylhydantoin, 5-methylimidazolidine-2,4-dione or 5-(4-hydroxyphenyl)imidazolidine-2,4-dione; The cytosine nucleotide sodium salt is selected from cytidine-5'-triphosphate sodium salt, cytidine-5'-diphosphate sodium salt, cytidine-5'-monophosphate sodium salt, 2'-deoxycytidine 5'-triphosphate sodium salt, 2'-deoxycytidine 5'-diphosphate sodium salt or 2'-deoxycytidine 5'-monophosphate sodium salt; The compound containing a succinimide structure is selected from maleimide, succinimide, 4-aminophthalimide or 1,2-cyclohexanedicarboximide; The dispersant is sodium methylene dinaphthalene sulfonate; The additive is a mixture of 4-methyl-N-toluenesulfonylbenzenesulfonamide and sodium 3-mercapto-1-propanesulfonate, and the mass ratio of 4-methyl-N-toluenesulfonylbenzenesulfonamide to sodium 3-mercapto-1-propanesulfonate is 1.5-2.5:

1.

2. The brush plating silver alloy plating solution for repairing the silver plating layer of the open type disconnector according to claim 1 is characterized in that: The silver salt is silver nitrate or silver methanesulfonate.

3. The brush plating silver alloy plating solution for repairing the silver plating layer of the open type disconnector according to claim 1 is characterized in that: The conductive salt is sodium carbonate, potassium carbonate, ammonium acetate or potassium sodium tartrate.

4. The brush plating silver alloy plating solution for repairing the silver plating layer of the open type disconnector according to claim 3 is characterized in that: When the conductive salt is sodium carbonate or potassium carbonate, the concentration of sodium carbonate or potassium carbonate is 10-30 g / L; When the conductive salt is ammonium acetate, the concentration of ammonium acetate is 10-20 g / L; When the conductive salt is potassium sodium tartrate, the concentration of potassium sodium tartrate is 5-20 g / L.

5. The brush plating silver alloy plating solution for repairing the silver plating layer of the open type disconnector according to claim 1, characterized in that: The pH value of the plating solution is 9-11.

6. The brush plating silver alloy plating solution for repairing the silver plating layer of the open type disconnector according to claim 5, characterized in that: The pH value regulator of the plating solution is KOH.

7. A method for preparing a brush-plated silver alloy plating solution for repairing the silver-plated layer of an open-type disconnector according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: firstly, dissolving silver salt in a small amount of deionized water to obtain solution A; Cytosine nucleotide sodium salt, a compound containing a succinimide structure, and a compound containing an ureide structure are sequentially placed in an appropriate amount of water and dissolved at a dissolution temperature of 30-50°C, and then potassium antimony tartrate solution is added thereto to form solution B; The above solution A and solution B are mixed and stirred evenly, and then dispersant, conductive salt and additives are added in sequence to form solution C; KOH was added to solution C to adjust the pH value of the solution to 9-11 to obtain the final solution.

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