Electroplating solution containing matte tin plating additive and preparation method thereof

Abstract

This invention mainly relates to the field of metal surface treatment technology, specifically an electroplating solution containing a matte tin plating additive and its preparation method. The solution includes 180 ml / L methanesulfonic acid, 70 ml / L stannous methanesulfonate, and a matte tin plating additive. The matte tin plating additive comprises the following components at mass-volume concentrations: 30-100 g / L dispersant, 100-300 g / L organic solvent, 0-10 g / L grain refiner, 50-100 g / L complexing agent, 5-10 g / L antioxidant, and water. Preparation of the matte tin plating additive: Step 100, water and organic solvent are added to a reaction vessel and stirred; Step 200, the dispersant, grain refiner, complexing agent, and antioxidant are added sequentially, and stirred for 2-5 hours to obtain the matte tin plating additive. In this application, the combined effect of the dispersant and grain refiner increases the gloss of the plating layer and improves the adhesion between the plating layer and the grains, and between the grains themselves.

Description

Technical Field

[0001] This invention relates to the field of metal surface treatment technology, specifically to an electroplating solution containing a matte tin plating additive and its preparation method. Background Technology

[0002] Tin-plated products have the advantages of corrosion resistance, discoloration resistance, non-toxicity, easy soldering, softness, low melting point and good ductility. They can effectively protect metal substrates and prevent chemical reactions such as oxidation and corrosion, so that the substrates are not affected by the external environment during use. They are widely used in food packaging, electronic component packaging, aerospace, automotive industry and building materials.

[0003] To reduce light pollution, matte tin plating is now widely used in the packaging of electronic components. This not only reduces residual carbon content in the plating, minimizes discoloration, and improves solderability, but also reduces tin whisker formation by controlling the crystallization state and grain size. However, in actual production, it has been found that the larger crystal grains reduce the bonding strength between the plating and the substrate, and between the grains themselves. This is especially true for electronic components, where the plating itself, the cutting force generated during the cutting process, and vibrations during transportation can cause the tin plating to tear and peel off. The detached tin dross adheres to the molding compound or other locations, making it difficult to detect and remove. When these problematic materials are used in electronic products, the attached tin dross can appear anywhere due to vibration and movement, causing short circuits, damage, and shortening the product's lifespan. Furthermore, existing matte tin plating has a duller color and an unsatisfactory appearance, negatively impacting the customer's first impression of the product.

[0004] Therefore, there is an urgent need for an electroplating solution containing matte tin plating additives to solve the above problems. Summary of the Invention

[0005] To achieve the above objectives, this application employs the following technical solution: An electroplating solution containing a matte tin plating additive includes methanesulfonic acid at a concentration of 180 ml / L, stannous methanesulfonate at a concentration of 70 ml / L, and a matte tin plating additive, wherein the matte tin plating additive comprises components with the following mass-volume concentrations: 30-100 g / L dispersant, 100-300 g / L organic solvent, 0-10 g / L grain refiner composition, 50-100 g / L complexing agent, 5-10 g / L antioxidant, and water. Furthermore, as shown in the appendix Figure 2 As shown, the preparation method of the matte tin plating additive includes the following steps: Step 100: Add water and organic solvent to the reaction vessel and start stirring; Step 200: Add dispersant, grain refiner composition, complexing agent and antioxidant in sequence, and stir continuously for 2-5 hours until completely dissolved to obtain matte tin plating additive.

[0006] Furthermore, in the matte tin plating additive, the dispersant is a spreading surfactant obtained by modifying a low-foaming nonionic surfactant, such as the attached... Figure 3 As shown, its preparation method includes the following steps: Step 1: Add the low-foaming surfactant, catalyst, and first solvent to the reaction vessel; Step 2: Under nitrogen protection, add the modifier and react at 50-150℃ for 2-10 hours; Step 3 involves evaporating under reduced pressure, using anhydrous ethanol to precipitate inorganic substances, and evaporating away excess ethanol to obtain a dispersant. The first solvent and catalyst are removed by the reduced pressure evaporation.

[0007] Furthermore, in step 1, the structure of the low-foaming surfactant is R-(C2H4O). m (C3H6O) n H, where R is selected from C0-C 20 Branched or branched fatty alcohols, C0-C 20 Branched or branched aliphatic amines, including EOPO copolymers, lauryl alcohol polyoxyethylene ether polyoxypropylene ethers, lauryl amine polyoxyethylene ether polyoxypropylene ethers, lauryl alcohol polyoxyethylene ethers, isomeric tridecyl alcohol polyoxyethylene ether polyoxypropylene ethers, and isomeric C 10 -C 13 The EOPO copolymer is any one or a combination of amine polyoxyethylene ether polyoxypropylene ether and hexadecamine polyoxyethylene ether polyoxypropylene ether, wherein the EOPO copolymer is any one of BASF polyoxyethylene ether polyoxypropylene ether copolymers PE6400, PE10500 and PE6800. Furthermore, in R-(C2H4O) m (C3H6O) n In H, m and n are the number of EO and PO in the low-foaming surfactant, which are integers ranging from 0 to 20; Furthermore, the catalyst is any one or more of sodium hydroxide, potassium hydroxide, sodium ethoxide, and potassium ethoxide; Furthermore, the first solvent is any one or two of toluene, xylene, pyridine, 1,2-propanediol, ethylene glycol, n-butanol, ethyl acetate, and octane; Furthermore, in step 2, the modifier is any one of concentrated sulfuric acid, fuming sulfuric acid, sulfur trioxide, chlorosulfonic acid, sodium sulfite, chloroacetic acid, acrylic acid, methacrylic acid, succinic acid, succinic acid, malic acid, citric acid, and gluconic acid.

[0008] Furthermore, in the matte tin plating additive, the organic solvent is one or two of methanol, ethanol, n-propanol, isopropanol, ethylene glycol, ethylene glycol n-propyl ether, diethylene glycol butyl ether, 1,2-propanediol, 1,3-propanediol, diethylene glycol, and polyethylene glycol 400.

[0009] Furthermore, in the matte tin plating additive, the grain refiner composition includes a low-zone grain refiner, a high-zone grain refiner, and a comprehensive grain refiner in a content ratio of 1:0-1.5:0-0.5.

[0010] Furthermore, the low-density grain refiner is a small-molecule nitrogen- and sulfur-containing organic compound, and is any one of thiourea, urea, glycine, tyrosine, aspartic acid, asparagine, glutamic acid, threonine, cysteine, sodium benzenesulfonate, aminoethanesulfonic acid, p-aminosulfonamide, and p-toluenesulfonic acid. The high-grain refiner is any one or a combination of thiophene and its derivatives, thiazole and its derivatives, imidazole and its derivatives, pyridine and its derivatives, pyrimidine and its derivatives, and quinoline and its derivatives.

[0011] Further, the comprehensive grain refiner is an aromatic cyclic compound that has undergone sulfonation, i.e., an aromatic sulfonation product. The aromatic cyclic compound is any one or two of the following: sodium benzoate, sodium naphthalenesulfonate, naphthoic acid, benzylamine, benzoylcarboxylic acid, benzamide, p-methoxybenzenesulfonic acid, rhein, alizarin, quercetin, curcumin, coumarin, naringenin, puerarin, luteolin, and myricetin. The sulfonation reaction includes the following steps: S1: Add the aromatic compound to the reaction vessel, add ethylene glycol monopropyl ether and stir to dissolve, maintaining the temperature at 50-100℃; S2: Slowly add concentrated sulfuric acid dropwise into the reactor to carry out the sulfonation reaction for 3-6 hours; S3: After the reaction is complete, the solvent is removed by rotary evaporation, and the sulfuric acid is neutralized to neutral with sodium hydroxide ethanol solution; S4: Add anhydrous ethanol to precipitate the salt, and evaporate to remove excess ethanol to obtain the desired aromatic sulfonated product.

[0012] Furthermore, in the matte tin plating additive, the complexing agent is any one or two of sodium gluconate, sodium gluconate, sodium citrate, sodium tartrate, disodium EDTA, lactic acid, and succinic acid.

[0013] Furthermore, in the matte tin plating additive, the antioxidant is any one of catechol, hydroquinone, ascorbic acid, and sodium hypophosphite.

[0014] A method for preparing an electroplating solution containing a matte tin plating additive includes the following steps: Step 10: Add deionized water to the reactor and turn on the stirring device at a speed of 150 r / min, and slowly add methanesulfonic acid; Step 20: Continue to add stannous methanesulfonate and stir at 25°C for 20 minutes. After it is completely dissolved, set the stirring speed to 120 r / min. Step 30: Continue to slowly add matte tin plating additive, then adjust the rotation speed to 180 r / min, stir for 30 min to obtain the electroplating solution.

[0015] Compared with the prior art, the beneficial effects of this application are: the technical solution in this application increases the gloss of the coating, reduces the crystal grain size of the coating, reduces the porosity and gaps between grains, improves the bonding force between the coating and the grains and between grains, reduces the problem of tin falling off due to cutting, transportation, etc., and improves the product qualification rate. Attached Figure Description

[0016] Appendix Figure 1 This is a process flow diagram of the electroplating solution preparation method of the present invention; Appendix Figure 2 This is a process flow diagram of the method for preparing the matte tin plating additive of the present invention; Appendix Figure 3 This is a process flow diagram of the dispersant preparation method of the present invention; Appendix Figure 4 This is a process flow diagram of the sulfonation reaction during the preparation of the comprehensive grain refiner according to the present invention; Appendix Figure 5 These are the appearance effect diagrams of the coating in Example 1 of the present invention, wherein (a) is the appearance effect diagram of the coating in Example 1 under the conditions of current 0.5A, electroplating time 5min and temperature 25℃, and (b) is the appearance effect diagram of the coating in Example 1 under the conditions of current 1A, electroplating time 5min and temperature 25℃. Appendix Figure 6 These are the appearance effect diagrams of the coating in Example 2 of the present invention, wherein (a) is the appearance effect diagram of the coating in Example 2 under the conditions of current 0.5A, electroplating time 5min and temperature 25℃, and (b) is the appearance effect diagram of the coating in Example 2 under the conditions of current 1A, electroplating time 5min and temperature 25℃. Appendix Figure 7 These are the appearance effect diagrams of the coating in Example 3 of the present invention, wherein (a) is the appearance effect diagram of the coating in Example 3 under the conditions of current 0.5A, electroplating time 5min and temperature 25℃, and (b) is the appearance effect diagram of the coating in Example 3 under the conditions of current 1A, electroplating time 5min and temperature 25℃. Appendix Figure 8These are the appearance effect diagrams of the coating in Example 4 of the present invention, wherein (a) is the appearance effect diagram of the coating in Example 4 under the conditions of current 0.5A, electroplating time 5min and temperature 25℃, and (b) is the appearance effect diagram of the coating in Example 4 under the conditions of current 1A, electroplating time 5min and temperature 25℃. Appendix Figure 9 These are the appearance effect diagrams of the coating in Example 5 of the present invention, wherein (a) is the appearance effect diagram of the coating in Example 5 under the conditions of current 0.5A, electroplating time 5min and temperature 25℃, and (b) is the appearance effect diagram of the coating in Example 5 under the conditions of current 1A, electroplating time 5min and temperature 25℃. Appendix Figure 10 These are the appearance effect diagrams of the coating in Example 6 of the present invention, wherein (a) is the appearance effect diagram of the coating in Example 6 under the conditions of current 0.5A, electroplating time 5min and temperature 25℃, and (b) is the appearance effect diagram of the coating in Example 6 under the conditions of current 1A, electroplating time 5min and temperature 25℃. Appendix Figure 11 These are the appearance effect diagrams of the coating of Comparative Example 1 in this invention, wherein (a) is the appearance effect diagram of the coating of Comparative Example 1 under the conditions of current 0.5A, electroplating time 5min and temperature 25℃, and (b) is the appearance effect diagram of the coating of Comparative Example 1 under the conditions of current 1A, electroplating time 5min and temperature 25℃. Appendix Figure 12 These are the appearance effect diagrams of the coating of Comparative Example 2 in this invention, wherein (a) is the appearance effect diagram of the coating of Comparative Example 2 under the conditions of current 0.5A, electroplating time 5min and temperature 25℃, and (b) is the appearance effect diagram of the coating of Comparative Example 2 under the conditions of current 1A, electroplating time 5min and temperature 25℃. Appendix Figure 13 These are the appearance effect diagrams of the coating of Comparative Example 5 in this invention, wherein (a) is the appearance effect diagram of the coating of Comparative Example 5 under the conditions of current 0.5A, electroplating time 5min and temperature 25℃, and (b) is the appearance effect diagram of the coating of Comparative Example 5 under the conditions of current 1A, electroplating time 5min and temperature 25℃. Appendix Figure 14 This is a sample image obtained using the electroplating solution of this invention; Appendix Figure 15 This is another sample image obtained using the electroplating solution of this invention; Appendix Figure 16 This is a SEM image of the sample prepared using the electroplating solution of Example 1 in this invention; Appendix Figure 17 This is a SEM image of the sample prepared using the electroplating solution of Example 2 in this invention; Appendix Figure 18This is a SEM image of the sample prepared using the electroplating solution of Example 3 in this invention; Appendix Figure 19 This is a SEM image of the sample prepared using the electroplating solution of Example 4 in this invention; Appendix Figure 20 This is a SEM image of the sample prepared using the electroplating solution of Example 5 in this invention; Appendix Figure 21 This is a SEM image of the sample prepared using the electroplating solution of Example 6 in this invention. Detailed Implementation

[0017] The present application will be further described in conjunction with the accompanying drawings and specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this application, those skilled in the art can make various alterations or modifications to this application, and these equivalent forms also fall within the scope defined by this application.

[0018] An electroplating solution containing a matte tin plating additive includes methanesulfonic acid at a concentration of 180 ml / L, stannous methanesulfonate at a concentration of 70 ml / L, and a matte tin plating additive, wherein the matte tin plating additive comprises components with the following mass-volume concentrations: 30-100 g / L dispersant, 100-300 g / L organic solvent, 0-10 g / L grain refiner composition, 50-100 g / L complexing agent, 5-10 g / L antioxidant, and water.

[0019] The preparation method of the matte tin plating additive includes the following steps: Step 100: Add water and organic solvent to the reaction vessel and start stirring; Step 200: Add dispersant, grain refiner composition, complexing agent, and antioxidant sequentially, and stir continuously for 2-5 hours until completely dissolved to obtain matte tin plating additive. The matte tin plating additive in this application, through the combined action of dispersant and grain refiner composition, forms suitable adsorption on the substrate surface within a wide current density range, which to a certain extent reduces the plating speed of tin ions, increases the density between tin and substrate, and between tin and tin, and increases the bonding force between plating layers and between grains. At the same time, the reasonable selection of grain refiner makes the plating layer exhibit a certain metallic color.

[0020] In matte tin plating additives, the dispersant is a low-foaming, high-cloud-point ductile surfactant obtained by modifying a low-foaming nonionic surfactant. The modification treatment involves carboxylation or sulfonation to increase its cloud point, significantly reducing foaming issues in the electroplating solution, minimizing foam generation during production, and simplifying subsequent rinsing. The dispersant preparation method includes the following steps: Step 1: Add the low-foaming surfactant, catalyst, and first solvent to the reaction vessel; Step 2: Under nitrogen protection, add the modifier and react at 50-150℃ for 2-10 hours; Step 3: Remove the first solvent and catalyst by vacuum evaporation, and add 900-1000 ml of anhydrous ethanol to precipitate inorganic matter. Filter to remove crystals, and distill to remove ethanol to obtain the dispersant.

[0021] In some preferred embodiments of this application, the inorganic matter can be removed by anhydrous ethanol 3-5 times, while a small amount of activated carbon can be added and heated to 40-60°C for decolorization.

[0022] The modified dispersant has a higher cloud point, which can increase the operating temperature of the electroplating solution and improve its solubility, allowing it to better dissolve the grain refiner composition.

[0023] The structural formula of the dispersant can generally be represented as REAM, where R refers to linear or branched fatty alcohol residues, E is a polyether segment containing polyoxyethylene or polyoxypropylene, such as polyoxyethylene ether, polyoxypropylene ether, polyoxypropylene / polyoxyethylene block copolymer ether, and polyoxypropylene / polyoxyethylene random copolymer ether, A is a hydrophilic ionic head, such as sulfonic acid group or carboxylic acid group, and M is an antiparticle, such as H. + Na + K + NH4 + This structure, compared to traditional surfactants, has advantages such as low foaming, high cloud point, and high salt resistance.

[0024] Specifically, in step 1, the structure of the low-foaming surfactant is R-(C2H4O). m (C3H6O) n H, where R is selected from C0-C 20 Branched or branched fatty alcohols, C0-C 20 Branched or branched aliphatic amines, including EOPO copolymers, lauryl alcohol polyoxyethylene ether polyoxypropylene ethers, lauryl amine polyoxyethylene ether polyoxypropylene ethers, lauryl alcohol polyoxyethylene ethers, isomeric tridecyl alcohol polyoxyethylene ether polyoxypropylene ethers, and isomeric C 10 -C 13 The EOPO copolymer is any one or a combination of amine polyoxyethylene ether polyoxypropylene ether and hexadecamine polyoxyethylene ether polyoxypropylene ether, wherein the EOPO copolymer is any one of BASF polyoxyethylene ether polyoxypropylene ether copolymers PE6400, PE10500, and PE6800; in R-(C2H4O) m (C3H6O) n In H, m and n are the number of EO and PO in the low-foaming surfactant, which are integers ranging from 0 to 20; The catalyst is any one or more of sodium hydroxide, potassium hydroxide, sodium ethoxide, and potassium ethoxide; The first solvent is any one or two of toluene, xylene, pyridine, 1,2-propanediol, ethylene glycol, n-butanol, ethyl acetate, and octane; In step 2, the modifier is any one of concentrated sulfuric acid, fuming sulfuric acid, sulfur trioxide, chlorosulfonic acid, sodium sulfite, chloroacetic acid, acrylic acid, methacrylic acid, succinic acid, succinic acid, malic acid, citric acid, and gluconic acid.

[0025] In the matte tin plating additive, the organic solvent is one or two of methanol, ethanol, n-propanol, isopropanol, ethylene glycol, ethylene glycol n-propyl ether, diethylene glycol butyl ether, 1,2-propanediol, 1,3-propanediol, diethylene glycol, and polyethylene glycol 400.

[0026] In matte tin plating additives, grain refiners include low-zone grain refiners, high-zone grain refiners, and comprehensive grain refiners in a content ratio of 1:0-1.5:0-0.5.

[0027] The low-density grain refiner is a small-molecule nitrogen- and sulfur-containing organic compound, and is any one of thiourea, urea, glycine, tyrosine, aspartic acid, asparagine, glutamic acid, threonine, cysteine, sodium benzenesulfonate, aminoethanesulfonic acid, p-aminosulfonamide, and p-toluenesulfonic acid. The high-grain refiner is any one or a combination of thiophene and its derivatives, thiazole and its derivatives, imidazole and its derivatives, pyridine and its derivatives, pyrimidine and its derivatives, and quinoline and its derivatives. In some preferred embodiments of this application, it may be diaminothiophene, α-acetylthiophene, α-vinylthiophene, thiophene-α-acetic acid, thiophene-α-ethylamine, 1-benzothiophene-3-carboxylic acid, benzothiophene, benzothiazole, 2-mercaptobenzothiazole, 2-aminobenzothiazole, benzothiazole-2-sulfonic acid, thiazole-2-acetic acid, 2,5-dimercapto-1,3,4-thiadiazole, 2-mercaptobenzothiazole, benzotriazole, 2-mercaptobenzimidazole, 2-aminobenzimidazole, aminopyridine, 3,5-dimethylpyridine, dimethylpyridineamine, 2-amino-6- The following are any one or combinations of methylpyridine, 2,6-dihydroxypyridine, 5-hydroxy-2-methoxypyridine, 2-hydroxy-5-aminopyridine, 5-ethylpyridine-2,3-dicarboxylic acid, 2-amino-4-ethylpyridine, 2-ethyl-5-methyl-3-hydroxypyridine, 2-benzylpyridine, 4-benzylpyridine, pyridine, 2,6-dicarboxylic acid, isonicotinic acid, 2-methoxypyridine, 5-hydroxynicotinic acid, 4-isopropyl-2-methylpyrimidine, 4-phenyl-uracil, N,2-dimethyl-5-pyrimidineamine, 2-methylquinoline, 2-phenylaminoquinoline, and o-phenanthroline.

[0028] The comprehensive grain refiner is an aromatic ring compound that has undergone sulfonation, i.e., an aromatic sulfonation product. The aromatic ring compound is any one or two of the following: sodium benzoate, sodium naphthalenesulfonate, naphthoic acid, benzylamine, benzoylformic acid, benzamide, p-methoxybenzenesulfonic acid, rhein, alizarin, quercetin, curcumin, coumarin, naringenin, puerarin, luteolin, and myricetin. The sulfonation reaction can improve the solubility of the aromatic ring compound. The sulfonation reaction includes the following steps, as shown in the appendix. Figure 4 As shown: S1: Add the aromatic compound to the reaction vessel, add ethylene glycol monopropyl ether and stir to dissolve, maintaining the temperature at 50-100℃; S2: Slowly add concentrated sulfuric acid dropwise into the reactor to carry out the sulfonation reaction for 3-6 hours; S3: After the reaction is complete, the solvent is removed by rotary evaporation, and the sulfuric acid is neutralized to neutral with sodium hydroxide ethanol solution; S4: Add anhydrous ethanol to precipitate the salt, and evaporate to remove excess ethanol to obtain the desired aromatic sulfonated product.

[0029] In matte tin plating additives, the complexing agent is any one or two of sodium gluconate, sodium gluconate, sodium citrate, sodium tartrate, disodium ethylenediaminetetraacetate, lactic acid, and succinic acid.

[0030] In the matte tin plating additive, the antioxidant is any one of catechol, hydroquinone, ascorbic acid, and sodium hypophosphite.

[0031] A method for preparing an electroplating solution containing a matte tin plating additive includes the following steps: Step 10: Add deionized water to the reactor and turn on the stirring device at a speed of 150 r / min, and slowly add methanesulfonic acid; Step 20: Continue to add stannous methanesulfonate and stir at 25°C for 20 minutes. After it is completely dissolved, set the stirring speed to 120 r / min. Step 30: Continue to slowly add matte tin plating additive, then adjust the rotation speed to 180 r / min, stir for 30 min to obtain the electroplating solution.

[0032] Example 1 An electroplating solution containing a matte tin plating additive includes methanesulfonic acid at a concentration of 180 ml / L, stannous methanesulfonate at a concentration of 70 ml / L, and a matte tin plating additive, wherein the matte tin plating additive comprises components with the following mass-volume concentrations: 60 g / L dispersant, 150 g / L 1,2-propanediol, 0-10 g / L grain refiner composition, 70 g / L sodium gluconate, 10 g / L catechol, and water.

[0033] The grain refiner composition includes 1 g / L of thiourea as a low-zone grain refiner, 2 g / L of 2-aminobenzothiazole as a high-zone grain refiner, and 0.5 g / L of sodium naphthalenesulfonate as a comprehensive grain refiner.

[0034] The preparation of the dispersant includes the following steps: Step 1: Add 1 mol PE6400, 0.8 mol sodium hydroxide and 2 mol toluene to the reaction vessel; Step 2: Under nitrogen protection, add 1 mol of chlorosulfonic acid and react at 70-90℃ for 3-5 hours; Step 3: Remove the first solvent and catalyst by vacuum evaporation, add 900-1000 ml of anhydrous ethanol to dissolve the reaction product, filter to remove the crystals, and distill to remove the ethanol to obtain the dispersant.

[0035] Example 2 An electroplating solution containing a matte tin plating additive includes methanesulfonic acid at a concentration of 180 ml / L, stannous methanesulfonate at a concentration of 70 ml / L, and a matte tin plating additive, wherein the matte tin plating additive comprises components with the following mass-volume concentrations: 60 g / L dispersant, 150 g / L 1,2-propanediol, 0-10 g / L grain refiner composition, 70 g / L sodium gluconate, 10 g / L catechol, and water.

[0036] The grain refiner composition includes 1 g / L of thiourea as a low-zone grain refiner, 2 g / L of thiophene-α-acetic acid as a high-zone grain refiner, and 0.5 g / L of sodium naphthalenesulfonate as a comprehensive grain refiner.

[0037] The preparation of the dispersant includes the following steps: Step 1: Add 1 mol of isomeric tridecylamine polyoxyethylene ether polyoxypropylene ether, 0.8 mol of sodium ethoxide and 2 mol of toluene to the reaction vessel; Step 2: Under nitrogen protection, add 1 mol of chlorosulfonic acid and react at 50-70℃ for 2-4 hours; Step 3: Remove the first solvent and catalyst by vacuum evaporation, add 900-1000 ml of anhydrous ethanol to dissolve the reaction product, filter to remove the crystals, and distill to remove the ethanol to obtain the dispersant.

[0038] Example 3 An electroplating solution containing a matte tin plating additive includes methanesulfonic acid at a concentration of 180 ml / L, stannous methanesulfonate at a concentration of 70 ml / L, and a matte tin plating additive, wherein the matte tin plating additive comprises components with the following mass-volume concentrations: 60 g / L dispersant, 150 g / L 1,2-propanediol, 0-10 g / L grain refiner composition, 70 g / L sodium gluconate, 10 g / L catechol, and water.

[0039] The grain refiner composition includes 1 g / L of thiourea as a low-zone grain refiner, 2 g / L of thiophene-α-acetic acid as a high-zone grain refiner, and 0.5 g / L of sodium naphthalenesulfonate as a comprehensive grain refiner.

[0040] The carboxylation process, which involves carboxylating the dispersant during preparation, includes the following steps: Step 1: Add 1 mol of isomeric tridecylamine polyoxyethylene ether polyoxypropylene ether and 1.5 mol of sodium hydroxide to a three-necked flask and stir. Step 2: Add 1.5 mol sodium chloroacetate and react at 50-80℃ for 5 hours; Step 3: Add sodium hydroxide ethanol solution to adjust the pH to neutral, dissolve the product in hot ethanol, filter while hot to remove inorganic salts, and vacuum dry to obtain the dispersant.

[0041] Example 4 An electroplating solution containing a matte tin plating additive includes methanesulfonic acid at a concentration of 180 ml / L, stannous methanesulfonate at a concentration of 70 ml / L, and a matte tin plating additive, wherein the matte tin plating additive comprises components with the following mass-volume concentrations: 60 g / L dispersant, 150 g / L 1,2-propanediol, 0-10 g / L grain refiner composition, 70 g / L sodium gluconate, 10 g / L catechol, and water.

[0042] The grain refiner composition includes 1 g / L of thiourea as a low-zone grain refiner, 2 g / L of thiophene-α-acetic acid as a high-zone grain refiner, and 0.5 g / L of sodium naphthalenesulfonate as a comprehensive grain refiner.

[0043] The carboxylation process, which involves carboxylating the dispersant during preparation, includes the following steps: Step 1: Add 1 mol of dodecyl alcohol polyoxyethylene ether 15EO and 1.5 mol of potassium ethoxide to a three-necked flask and stir. Step 2: Add 1.5 mol of methacrylic acid and react at 70-110℃ for 5 hours; Step 3: Add sodium hydroxide ethanol solution to adjust the pH to neutral, dissolve the product in hot ethanol, filter while hot to remove inorganic salts, and vacuum dry to obtain the dispersant.

[0044] Example 5 An electroplating solution containing a matte tin plating additive comprises 180 ml / L of methanesulfonic acid, 70 ml / L of stannous methanesulfonate, and a matte tin plating additive, wherein the matte tin plating additive comprises components with the following mass-volume concentrations: 60 g / L of dispersant, 150 g / L of 1,2-propanediol, 0-10 g / L of grain refiner composition, 70 g / L of sodium gluconate, 10 g / L of catechol, and water, wherein the dispersant is a dispersant synthesized by the operation of Example 3.

[0045] The grain refiner composition includes 1 g / L of cysteine ​​(low-zone grain refiner), 2 g / L of 2-aminobenzothiadiazole (high-zone grain refiner), and 0.5 g / L of alizarin sulfonate (comprehensive grain refiner).

[0046] The preparation of the comprehensive grain refiner, alizarin sulfonate, includes the following steps: S1: Add 0.1 mol of alizarin to the reaction vessel, add 0.5 mol of ethylene glycol monopropyl ether and stir to dissolve, maintaining the temperature at 50-90℃; S2: Slowly add 0.2 mol of concentrated sulfuric acid dropwise into the reactor to carry out the sulfonation reaction for 4 hours; S3: After the reaction is complete, the solvent is removed by rotary evaporation, and the sulfuric acid is neutralized to neutral with sodium hydroxide ethanol solution; S4: Add anhydrous ethanol to precipitate the salt, and evaporate to remove excess ethanol to obtain the desired aromatic sulfonated product.

[0047] Example 6 An electroplating solution containing a matte tin plating additive comprises 180 ml / L of methanesulfonic acid, 70 ml / L of stannous methanesulfonate, and a matte tin plating additive, wherein the matte tin plating additive comprises components with the following mass-volume concentrations: 60 g / L of dispersant, 150 g / L of 1,2-propanediol, 0-10 g / L of grain refiner composition, 70 g / L of sodium gluconate, 10 g / L of catechol, and water, wherein the dispersant is a dispersant synthesized by the operation of Example 3.

[0048] The grain refiner composition includes 1.5 g / L of glycine (low-zone grain refiner), 1.5 g / L of 2-aminoquinoline (high-zone grain refiner), and 0.8 g / L of puerarin sulfonate (comprehensive grain refiner).

[0049] The preparation of puerarin sulfonate, a comprehensive grain refiner, includes the following steps: S1: Add 0.1 mol of puerarin to the reaction vessel, add 0.5 mol of ethylene glycol monopropyl ether and stir to dissolve, maintaining the temperature at 60-100℃; S2: Slowly add 0.2 mol of concentrated sulfuric acid dropwise into the reactor to carry out the sulfonation reaction for 4 hours; S3: After the reaction is complete, the solvent is removed by rotary evaporation, and the sulfuric acid is neutralized to neutral with sodium hydroxide ethanol solution; S4: Add anhydrous ethanol to precipitate the salt, evaporate to remove excess ethanol, and finally obtain the desired aromatic sulfonated product.

[0050] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that the low-foaming surfactant is unsulfonated PE6400.

[0051] Comparative Example 2 The difference between Comparative Example 2 and Example 2 is that the low-foaming surfactant is isomeric tridecylamine polyoxyethylene ether polyoxypropylene ether.

[0052] Comparative Example 3 The difference between Comparative Example 3 and Example 3 is that the low-foaming surfactant is dodecyl alcohol polyoxyethylene ether 15EO.

[0053] Comparative Example 4 The difference between Comparative Example 4 and Example 5 is that the grain refiner composition is only 2 g / L of high-zone grain refiner 2-aminobenzothiadiazole.

[0054] Comparative Example 5 The difference between Comparative Example 5 and Example 5 is that the grain refiner composition is only 1 g / L of low-zone grain refiner cysteine.

[0055] Comparative Example 6 The difference between Comparative Example 6 and Example 5 is that the grain refiner composition is only 0.5 g / L of the comprehensive grain refiner, alizarin sulfonate.

[0056] Finally, through HULL Cell and pilot tank plating tests, the foaming, cloud point, coating appearance and grain size, adhesion, and tin dross generation rate after cutting and vibration of the electroplating solutions prepared with the matte tin additives in Examples 1-6 and Comparative Examples 1-6 were tested. The experimental temperature was 25-30℃, the current was 0.5ASD, and the electroplating time was 20min. The test results are shown in Table 1.

[0057] Table 1:

[0058] Figures 5-13The images show the appearance of the tin plating layers containing matte tin plating additives in Examples 1-6 and Comparative Examples 1, 2, and 5 under different current densities and the same time and temperature conditions. The images marked (a) on the left are the appearance of the plating layers in Examples 1-6 and Comparative Examples 1, 2, and 5 under the conditions of a current of 0.5A, an electroplating time of 5min, and a temperature of 25℃. The images marked (b) on the left are the appearance of the plating layers in Examples 1-6 and Comparative Examples 1, 2, and 5 under the conditions of a current of 1A, an electroplating time of 5min, and a temperature of 25℃. Figure 14 , 15 Samples produced using the method of this application. Figure 16-21 The images shown are SEM images of Examples 1-6. In summary, compared to the electroplating solutions prepared with matte tin additives in Examples 1-4 and the electroplating solutions prepared with matte tin additive compositions in Comparative Examples 1-3, the electroplating solutions exhibit excellent performance in all aspects due to the reduced foaming degree caused by sulfonation or carboxylation, which increases the dissolution effect on the grain refiner. In synergy with the grain refiner, the plating layer performs exceptionally well. Relatively speaking, the isomeric tridecylamine polyoxyethylene ether polyoxypropylene ether and the acidified product are essentially foam-free and more suitable.

[0059] Compared with Example 4, Examples 2, 3, 5, 6, and Example 4 show that the coatings of Examples 2, 3, 5, and 6 have higher gloss than those of Example 4. This indicates that the plating solution prepared with a matte tin additive containing a ductile surfactant composed of branched alkyl groups has better gloss than the plating solution prepared with a matte tin additive containing a ductile surfactant composed of straight-chain alkyl groups.

[0060] In the matte tin additives of Examples 5 and 6, other types of refining agents were replaced, and the plating performance, plating gloss, adhesion, and tin dross generation rate still met the requirements.

[0061] In the matte tin additives of Comparative Examples 4-6, the plating performance, grain size, plating gloss, adhesion and tin dross generation rate were unsatisfactory when using high-zone refiners or low-zone refiners alone or in combination. Therefore, the examples using a combination of refiners were more satisfactory.

[0062] In Examples 1-6, the modified ductile surfactant of the matte tin additive, as demonstrated in electroplating tests, significantly reduced foaming and increased the dissolving effect on the grain refiner. Under the synergistic effect of the ductile surfactant and the grain refiner, the coating is uniform and fine overall, exhibiting a metallic luster. The coating crystallizes more evenly, with dense, pebble-like grains ranging from 3-7 micrometers in size. There are virtually no pores between the grains, resulting in no residual plating solution and extremely low residual carbon content. The coating is also less prone to discoloration. Furthermore, the adhesion between the coating and the substrate, and between grains, is excellent. The amount of tin dross generated and remaining on the material surface during production, cutting, and transportation is significantly reduced, decreasing product defect rates and increasing the product's market competitiveness.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. An electroplating solution containing a matte tin plating additive, characterized in that: It includes methanesulfonic acid at a concentration of 180 ml / L, stannous methanesulfonate at a concentration of 70 ml / L, and matte tin plating additive, wherein the matte tin plating additive includes the following components at mass-volume concentrations: 30-100 g / L dispersant, 100-300 g / L organic solvent, 0-10 g / L grain refiner composition, 50-100 g / L complexing agent, 5-10 g / L antioxidant, and water; The preparation method of the matte tin plating additive includes the following steps: Step 100: Add water and organic solvent to the reaction vessel and start stirring; Step 200: Add dispersant, grain refiner composition, complexing agent and antioxidant in sequence, and stir continuously for 2-5 hours until completely dissolved to obtain matte tin plating additive; In the matte tin plating additive, the dispersant is a spreading surfactant obtained by modifying a low-foaming nonionic surfactant, and its preparation method includes the following steps: Step 1: Add the low-foaming surfactant, catalyst, and first solvent to the reaction vessel; Step 2: Under nitrogen protection, add the modifier and react at 50-150℃ for 2-10 hours; Step 3: Dispersant is obtained by evaporation under reduced pressure, with inorganic matter precipitated using anhydrous ethanol, and excess ethanol evaporated away. In matte tin plating additives, the grain refiner composition includes a low-zone grain refiner, a high-zone grain refiner, and a comprehensive grain refiner in a content ratio of 1:0-1.5:0-0.

5. The comprehensive grain refiner is an aromatic cyclic compound that has undergone sulfonation, i.e., an aromatic sulfonation product. The aromatic cyclic compound is any one or two of the following: sodium benzoate, naphthoic acid, benzylamine, benzoylformic acid, benzamide, rhein, alizarin, quercetin, curcumin, coumarin, naringenin, puerarin, luteolin, and myricetin. The aromatic sulfonation product is also selected from sodium naphthalenesulfonate or p-methoxybenzenesulfonic acid. The sulfonation reaction includes the following steps: S1: Add the aromatic compound to the reaction vessel, add ethylene glycol monopropyl ether and stir to dissolve, maintaining the temperature at 50-100℃; S2: Slowly add concentrated sulfuric acid dropwise into the reactor to carry out the sulfonation reaction for 3-6 hours; S3: After the reaction is complete, the solvent is removed by rotary evaporation, and the sulfuric acid is neutralized to neutral with sodium hydroxide ethanol solution; S4: Add anhydrous ethanol to precipitate the salt, and evaporate the excess ethanol to obtain the desired aromatic sulfonated product. In step 1, the structure of the low-foaming surfactant is R-(C2H4O)m(C3H6O)nH, where R is selected from CO-C20 straight-chain or branched fatty alcohols and CO-C20 straight-chain or branched fatty amines, including any one or combination of EOPO copolymers, lauryl alcohol polyoxyethylene ether polyoxypropylene ethers, lauryl amine polyoxyethylene ether polyoxypropylene ethers, lauryl alcohol polyoxyethylene ethers, isomeric tridecyl alcohol polyoxyethylene ether polyoxypropylene ethers, isomeric C10-C13 amine polyoxyethylene ether polyoxypropylene ethers, and hexadecylamine polyoxyethylene ether polyoxypropylene ethers. The EOPO copolymer is any one of BASF polyoxyethylene ether polyoxypropylene ether copolymers PE6400, PE10500, and PE6800. In R-(C2H4O)m(C3H6O)nH, m and n are the number of EO and PO in the low-foaming surfactant, which are integers ranging from 0 to 20; The catalyst is any one or more of sodium hydroxide, potassium hydroxide, sodium ethoxide, and potassium ethoxide; The first solvent is any one or two of toluene, xylene, pyridine, 1,2-propanediol, ethylene glycol, n-butanol, ethyl acetate, and octane; In step 2, the modifier is any one of concentrated sulfuric acid, fuming sulfuric acid, sulfur trioxide, chlorosulfonic acid, sodium sulfite, chloroacetic acid, acrylic acid, methacrylic acid, succinic acid, succinic acid, malic acid, citric acid, and gluconic acid.

2. The electroplating solution containing matte tin plating additive according to claim 1, characterized in that: In the matte tin plating additive, the organic solvent is one or two of methanol, ethanol, n-propanol, isopropanol, ethylene glycol, ethylene glycol n-propyl ether, diethylene glycol butyl ether, 1,2-propanediol, 1,3-propanediol, diethylene glycol, and polyethylene glycol 400.

3. The electroplating solution containing matte tin plating additive according to claim 1, characterized in that: The low-density grain refiner is a small-molecule nitrogen- and sulfur-containing organic compound, and is any one of thiourea, urea, glycine, tyrosine, aspartic acid, asparagine, glutamic acid, threonine, cysteine, sodium benzenesulfonate, aminoethanesulfonic acid, p-aminosulfonamide, and p-toluenesulfonic acid. The high-grain refiner is any one or a combination of thiophene and its derivatives, thiazole and its derivatives, imidazole and its derivatives, pyridine and its derivatives, pyrimidine and its derivatives, and quinoline and its derivatives.

4. The electroplating solution containing matte tin plating additive according to claim 1, characterized in that: In matte tin plating additives, the complexing agent is any one or two of sodium gluconate, sodium gluconate, sodium citrate, sodium tartrate, disodium ethylenediaminetetraacetate, lactic acid, and succinic acid.

5. The electroplating solution containing matte tin plating additive according to claim 1, characterized in that: In matte tin plating additives, the antioxidant is any one of catechol, hydroquinone, ascorbic acid, and sodium hypophosphite.

6. A method for preparing an electroplating solution containing a matte tin plating additive according to any one of claims 1-5, characterized in that: Includes the following steps: Step 10: Add deionized water to the reactor and turn on the stirring device at a speed of 150 r / min, and slowly add methanesulfonic acid; Step 20: Continue to add stannous methanesulfonate and stir at 25°C for 20 minutes. After it is completely dissolved, set the stirring speed to 120 r / min. Step 30: Continue to slowly add matte tin plating additive, then adjust the rotation speed to 180 r / min, and stir for 30 min to obtain the electroplating solution.

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