Bright and environment-friendly electroless nickel plating solution and application thereof

Abstract

This invention discloses a bright and environmentally friendly electroless nickel plating solution and its application. The electroless nickel plating solution comprises solution A, solution B, and solution C. Solution A is prepared by adding 500-700L of water, 350-500kg of nickel salt, and 30-50g of a first stabilizer. Solution B is prepared by adding 300-500kg of buffer, 200-400kg of complexing agent, 150-300kg of reducing agent, 100-250L of pH adjuster, 100-200g of a first stabilizer, 5-30g of a second stabilizer, 500-800mL of organic brightener, and 20-60g of acetylene amine compound. The bright and environmentally friendly electroless nickel plating solution prepared by this invention does not contain heavy metals such as chromium, mercury, lead, and cadmium. It has a long service life, fast deposition speed, and produces a bright white coating with a mirror-like luster.

Description

Technical Field

[0001] This invention relates to the field of electroless nickel plating technology, classified under C23C18 / 36, and specifically to a bright and environmentally friendly electroless nickel plating solution and its application. Background Technology

[0002] Electroless nickel plating technology has advantages such as good corrosion resistance, high hardness, uniform coating, and the ability to uniformly plate complex-shaped parts. It is widely used in chemical, aerospace and other fields. The existing electroless nickel plating methods mainly use aqueous solutions containing nickel sulfate, sodium hypophosphite and other components. However, the solutions are relatively unstable. In traditional electroless nickel plating processes, divalent lead ions are often used as stabilizers and divalent cadmium ions as brighteners, which leads to the presence of heavy metals such as lead and cadmium in the wastewater, causing serious environmental pollution and failing to meet the trend of green environmental protection. Existing technologies also add additives such as thiourea, tungsticotropic acid, and iodic acid to stabilize the solution. However, although these additives improve the stability of the solution, they reduce the deposition rate of the coating, resulting in a decrease in corrosion resistance.

[0003] Chinese patent CN106048568B discloses an environmentally friendly electroless nickel plating method. It uses a composite of benzimidazole and potassium iodide-copper sulfate to achieve good stability and brightness in electroless nickel plating of citric acid system, with a service life of up to 8 metal cycles. However, it does not solve the technical problems of low deposition rate and high phosphorus content of the coating.

[0004] Chinese patent CN1073644C discloses a chemical nickel plating solution. By using citric acid and methyltetrahydroxyphenyl phthalic anhydride as additives, the stability and deposition rate of the plating solution are improved, and the corrosion resistance is also improved to a certain extent. However, its deposition rate is only 15-20 μm / h, and its service life is only 8 cycles, which still needs to be improved. Summary of the Invention

[0005] To address the aforementioned problems, the first aspect of this invention provides a bright and environmentally friendly electroless nickel plating solution. The electroless nickel plating solution comprises solution A, solution B, and solution C. Solution A is prepared from 500-700L of water, 350-500kg of nickel salt, and 30-50g of a first stabilizer. Solution B is prepared from 300-500kg of buffer, 200-400kg of complexing agent, 150-300kg of reducing agent, 100-250L of pH adjuster, 100-200g of a first stabilizer, 5-30g of a second stabilizer, 500-800mL of organic brightener, and 20-60g of acetyleneamine compound.

[0006] More preferably, the formulation of the electroless nickel plating solution includes solution A, solution B, and solution C. The raw materials for preparing solution A include 600-700L of water, 400-500kg of nickel salt, and 40-50g of a first stabilizer. The raw materials for preparing solution B include 400-500kg of buffer, 200-300kg of complexing agent, 150-250kg of reducing agent, 100-200L of pH adjuster, 100-150g of a first stabilizer, 8-20g of a second stabilizer, 600-700mL of organic brightener, and 30-60g of acetyleneamine compound.

[0007] More preferably, the formulation of the electroless nickel plating solution includes solution A, solution B, and solution C. The raw materials for preparing solution A include 667L of water, 450kg of nickel salt, and 45g of the first stabilizer. The raw materials for preparing solution B include 473.25kg of buffer, 235kg of complexing agent, 195.3kg of reducing agent, 125L of pH adjuster, 130g of the first stabilizer, 12.58g of the second stabilizer, 690mL of organic brightener, and 40g of acetyleneamine compound.

[0008] Preferably, the raw materials for preparing liquid C include 300-500L of water, 400-600kg of reducing agent, 90-120kg of complexing agent, 20-50kg of monoprotic weak acid, 70-100kg of acetate, 80-120L of pH adjuster, 40-70g of first stabilizer, 60-100g of second stabilizer, 1000-3000mL of organic brightener, 60-100g of acetyleneamine compound, and 200-400g of impurity removal powder.

[0009] More preferably, the raw materials for preparing liquid C include 400-500L of water, 450-550kg of reducing agent, 90-110kg of complexing agent, 30-40kg of monoprotic weak acid, 80-100kg of acetate, 90-120L of pH adjuster, 50-70g of first stabilizer, 80-100g of second stabilizer, 2000-3000mL of organic brightener, 80-100g of acetyleneamine compound, and 200-300g of impurity removal powder.

[0010] More preferably, the raw materials for preparing liquid C include 435L of water, 500kg of reducing agent, 101kg of complexing agent, 39kg of monoprotic weak acid, 88kg of acetate, 100L of pH adjuster, 60g of first stabilizer, 90g of second stabilizer, 2150mL of organic brightener, 90g of acetyleneamine compound, and 250g of impurity removal powder.

[0011] More preferably, the reducing agent is sodium hypophosphite, the complexing agent is malic acid and lactic acid in a mass ratio of 37.1:63.9, the monobasic weak acid is boric acid, the acetate is ammonium acetate, and the pH adjuster is ammonia.

[0012] Preferably, the A solution also includes 10-20g of inorganic brightener.

[0013] More preferably, the A solution also includes 15-20g of inorganic brightener.

[0014] More preferably, the liquid A also includes 17g of inorganic brightener.

[0015] The present invention adds 10-20g of tellurium dioxide to Ni 2+ While Ni-P is reduced and precipitated by sodium phosphite, its metal ions are also reduced and precipitated, thus becoming embedded in the Ni-P grains and preventing the growth of Ni-P unit cells, thereby refining the grains. On this basis, the addition of sodium 2-ethylhexyl sulfate, electroplating intermediate PME, and 2-methyl-3-butyn-2-amine not only accelerates the precipitation of nickel, achieving a deposition rate of 30 μm / h, but also greatly enhances the brightness and uniformity of the coating, resulting in finer crystals. The addition of a small amount of the acetyleneamine compound 2-methyl-3-butyn-2-amine reduces the accumulation rate of organic impurities, making the plating solution more stable.

[0016] Preferably, the inorganic brightener includes at least one of potassium chlorate, potassium bromate, cesium sulfate, silver nitrate, cadmium sulfate, and tellurium disulfide.

[0017] More preferably, the inorganic brightener is tellurium disulfide.

[0018] Preferably, the organic brightener includes at least one of hydroxyethyl propargyl ether, N,N-diethylpropargylamine, butynediol diethoxy ether, butynediol, sodium 2-ethylhexyl sulfate, and propargyl alcohol ethoxylate.

[0019] More preferably, the organic brightener is sodium 2-ethylhexyl sulfate and propynyl alcohol ethoxylate.

[0020] Preferably, the acetylene compound is 2-methyl-3-butyn-2-amine.

[0021] Preferably, the first stabilizer is an oxyacid salt.

[0022] Preferably, the second stabilizer is a thiourea derivative.

[0023] More preferably, the thiourea derivative is 3-isothiourea propane sulfonate inner salt.

[0024] Preferably, the oxyacid salt includes at least one of molybdate, iodate, and tungstate.

[0025] More preferably, the oxyacid salt is an iodate, and the iodate salt is potassium iodate.

[0026] This application uses a stabilizer obtained by combining 3-isothiourea propane sulfonate inner salt and potassium iodate, which greatly improves its stability and corrosion resistance. The covalent bond formed by the electron orbitals in the metal on the electrode surface and the lone pair electrons of the iodate ion produces characteristic adsorption. The sulfur atoms in the 3-isothiourea propane sulfonate inner salt not only make the coating more uniform and enhance corrosion resistance, but also adsorb on the electrode surface to form a hydrophilic film. The interaction between the two can also adsorb on the surface of colloidal particles in the plating solution, occupying the surface active centers, thereby preventing nickel deposition on these particles. The appropriate amount of both added improves stability while ensuring the deposition rate.

[0027] The present invention also provides a method for preparing a bright and environmentally friendly chemical nickel plating solution, comprising the following steps: (1) Preparation of the base plating solution: First, the raw materials in solution A are mixed according to the ratio to form component A, and then the raw materials in solution B are mixed to form component B; the raw materials in solution C are mixed to form component C, (2) Component A, component B and water are mixed in a certain weight ratio to obtain the base plating solution.

[0028] The second aspect of this invention provides an application of a bright and environmentally friendly electroless nickel plating solution in the electroless nickel plating of workpieces.

[0029] Further preferably, the application of the bright and environmentally friendly electroless nickel plating solution in electroless nickel plating of workpieces specifically includes the following steps: pre-treating the nickel-plated stainless steel workpiece, then adjusting the pH value of the base plating solution in the working tank to 4.5-5.5 with ammonia, heating it to 85-90℃, and then immersing the pre-treated nickel-plated stainless steel workpiece in the base plating solution for electroless nickel plating. (Maintenance of the base plating solution: During the electroless nickel plating process, it is necessary to periodically analyze the nickel ion concentration, hypophosphatemia ion concentration, and pH value in the plating solution, and adjust the addition amount of component A, component C, and ammonia appropriately according to the analysis results. When adding, component A and component C are directly added to the working tank solution in a certain proportion.)

[0030] Beneficial effects: The bright and environmentally friendly electroless nickel plating solution prepared by this invention does not contain heavy metals such as chromium, mercury, lead, and cadmium, which conforms to the concept of green environmental protection. It has excellent stability, long service life (up to 10 MTO), and fast deposition rate (up to 30 μm / h), which improves production efficiency. It has excellent uniform plating ability for complex parts, and the coating has good corrosion resistance and wear resistance. The coating has a bright white appearance with a mirror luster. It is not only suitable for most metal parts, such as steel, aluminum alloy, copper alloy, and stainless steel, but also for non-metallic materials such as plastics and ceramics. Example

[0031] Example 1

[0032] A bright and environmentally friendly electroless nickel plating solution, comprising solutions A, B, and C. Solution A is prepared from 667 L of water, 450 kg of nickel salt, 17 g of inorganic brightener, and 45 g of first stabilizer. Solution B is prepared from 473.25 kg of buffer, 235 kg of complexing agent, 195.3 kg of reducing agent, 125 L of pH adjuster, 130 g of first stabilizer, 12.58 g of second stabilizer, 690 mL of organic brightener, and 40 g of acetylene amine compound. Solution C is prepared from 435 L of water, 500 kg of reducing agent, 101 kg of complexing agent, 39 kg of monoprotic weak acid, 88 kg of acetate, 100 L of pH adjuster, 60 g of first stabilizer, 90 g of second stabilizer, 2150 mL of organic brightener, 90 g of acetylene amine compound, and 250 g of impurity removal powder.

[0033] The nickel salt is nickel sulfate.

[0034] The inorganic brightener is tellurium disulfide.

[0035] The first stabilizer is potassium iodate.

[0036] The second stabilizer is 3-isothiourea propane sulfonate inner salt.

[0037] The buffer is ammonium acetate, glacial acetic acid and boric acid, in a mass ratio of 382:83.6:7.65.

[0038] The complexing agents are malic acid and lactic acid, with a mass ratio of 77.5:157.5 in solution B and a mass ratio of 37.1:63.9 in solution C.

[0039] The reducing agent is sodium hypophosphite.

[0040] The pH adjuster is ammonia.

[0041] The organic brightener is sodium 2-ethylhexyl sulfate and propynyl alcohol ethoxylate, with a volume ratio of 20:3 in solution B and 23:192 in solution C.

[0042] The acetylamine compound is 2-methyl-3-butyn-2-amine.

[0043] The monoprotic weak acid is boric acid.

[0044] The acetate is ammonium acetate.

[0045] The impurity-removing powder is zinc powder.

[0046] This embodiment also provides a method for preparing a bright and environmentally friendly chemical nickel plating solution, including the following steps: (1) Preparation of the base plating solution: First, the raw materials in solution A are mixed according to the ratio to form component A, and then the raw materials in solution B are mixed to form component B; the raw materials in solution C are mixed to form component C, (2) Component A, component B and water are mixed in a weight ratio of 6:15:79 to obtain the base plating solution.

[0047] The second aspect of this invention provides an application of a bright and environmentally friendly electroless nickel plating solution in the electroless nickel plating of workpieces.

[0048] The application of the bright and environmentally friendly electroless nickel plating solution in electroless nickel plating of workpieces specifically includes the following steps: The nickel-plated stainless steel workpiece is degreased and washed with water. Then, the pH value of the base plating solution in the working tank is adjusted to 5.0 with ammonia water and heated to 87°C. The degreased and washed nickel-plated stainless steel workpiece is then immersed in the base plating solution for electroless nickel plating. The plating time is 1 hour. (Maintenance of the base plating solution: During the electroless nickel plating process, it is necessary to periodically analyze the nickel ion concentration, hypophosphite ion concentration, and pH value in the plating solution. Based on the analysis results, the addition amounts of component A, component C, and ammonia water are adjusted appropriately. When adding, component A and component C are directly added to the working tank solution in a 1:1 ratio. The Ni content in the plating solution...) 2+ The optimal concentration is 6.0 g / L, and the optimal concentration of sodium hypophosphite is 22.5 g / L.

[0049] Example 2

[0050] A bright and environmentally friendly electroless nickel plating solution, comprising solutions A, B, and C. Solution A is prepared from 667 L of water, 450 kg of nickel salt, 10 g of inorganic brightener, and 45 g of first stabilizer. Solution B is prepared from 473.25 kg of buffer, 235 kg of complexing agent, 195.3 kg of reducing agent, 125 L of pH adjuster, 130 g of first stabilizer, 12.58 g of second stabilizer, 800 mL of organic brightener, and 40 g of acetylene amine compound. Solution C is prepared from 435 L of water, 500 kg of reducing agent, 101 kg of complexing agent, 39 kg of monoprotic weak acid, 88 kg of acetate, 100 L of pH adjuster, 60 g of first stabilizer, 90 g of second stabilizer, 2150 mL of organic brightener, 90 g of acetylene amine compound, and 250 g of impurity removal powder.

[0051] The nickel salt is nickel sulfate.

[0052] The inorganic brightener is tellurium disulfide.

[0053] The first stabilizer is potassium iodate.

[0054] The second stabilizer is 3-isothiourea propane sulfonate inner salt.

[0055] The buffer is ammonium acetate, glacial acetic acid and boric acid, in a mass ratio of 382:83.6:7.65.

[0056] The complexing agents are malic acid and lactic acid, with a mass ratio of 77.5:157.5 in solution B and a mass ratio of 37.1:63.9 in solution C.

[0057] The reducing agent is sodium hypophosphite.

[0058] The pH adjuster is ammonia.

[0059] The organic brightener is sodium 2-ethylhexyl sulfate and propynyl alcohol ethoxylate, with a volume ratio of 20:3 in solution B and 23:192 in solution C.

[0060] The acetylamine compound is 2-methyl-3-butyn-2-amine.

[0061] The monoprotic weak acid is boric acid.

[0062] The acetate is ammonium acetate.

[0063] The impurity-removing powder is zinc powder.

[0064] The rest is the same as in Example 1.

[0065] Comparative Example 1

[0066] A bright and environmentally friendly electroless nickel plating solution, comprising solutions A, B, and C. Solution A is prepared from 667 L of water, 450 kg of nickel salt, 17 g of inorganic brightener, and 45 g of first stabilizer. Solution B is prepared from 473.25 kg of buffer, 235 kg of complexing agent, 195.3 kg of reducing agent, 125 L of pH adjuster, 143 g of first stabilizer, 690 mL of organic brightener, and 40 g of acetylene amine compound. Solution C is prepared from 435 L of water, 500 kg of reducing agent, 101 kg of complexing agent, 39 kg of monoprotic weak acid, 88 kg of acetate, 100 L of pH adjuster, 150 g of first stabilizer, 2150 mL of organic brightener, 90 g of acetylene amine compound, and 250 g of impurity removal powder.

[0067] The nickel salt is nickel sulfate.

[0068] The inorganic brightener is tellurium disulfide.

[0069] The first stabilizer is potassium iodate.

[0070] The buffer is ammonium acetate, glacial acetic acid and boric acid, in a mass ratio of 382:83.6:7.65.

[0071] The complexing agents are malic acid and lactic acid, with a mass ratio of 77.5:157.5 in solution B and a mass ratio of 37.1:63.9 in solution C.

[0072] The reducing agent is sodium hypophosphite.

[0073] The pH adjuster is ammonia.

[0074] The organic brightener is sodium 2-ethylhexyl sulfate and propynyl alcohol ethoxylate, with a volume ratio of 20:3 in solution B and 23:192 in solution C.

[0075] The acetylamine compound is 2-methyl-3-butyn-2-amine.

[0076] The monoprotic weak acid is boric acid.

[0077] The acetate is ammonium acetate.

[0078] The impurity-removing powder is zinc powder.

[0079] The rest is the same as in Example 1.

[0080] Comparative Example 2

[0081] A bright and environmentally friendly electroless nickel plating solution, comprising solutions A, B, and C. Solution A is prepared from 667 L of water, 450 kg of nickel salt, 5 g of inorganic brightener, and 45 g of first stabilizer. Solution B is prepared from 473.25 kg of buffer, 235 kg of complexing agent, 195.3 kg of reducing agent, 125 L of pH adjuster, 130 g of first stabilizer, 12.58 g of second stabilizer, 700 mL of organic brightener, and 40 g of acetylene amine compound. Solution C is prepared from 435 L of water, 500 kg of reducing agent, 101 kg of complexing agent, 39 kg of monoprotic weak acid, 88 kg of acetate, 100 L of pH adjuster, 60 g of first stabilizer, 90 g of second stabilizer, 2150 mL of organic brightener, 90 g of acetylene amine compound, and 250 g of impurity removal powder.

[0082] The nickel salt is nickel sulfate.

[0083] The inorganic brightener is tellurium disulfide.

[0084] The first stabilizer is potassium iodate.

[0085] The second stabilizer is 3-isothiourea propane sulfonate inner salt.

[0086] The buffer is ammonium acetate, glacial acetic acid and boric acid, in a mass ratio of 382:83.6:7.65.

[0087] The complexing agents are malic acid and lactic acid, with a mass ratio of 77.5:157.5 in solution B and a mass ratio of 37.1:63.9 in solution C.

[0088] The reducing agent is sodium hypophosphite.

[0089] The pH adjuster is ammonia.

[0090] The organic brightener is sodium 2-ethylhexyl sulfate and propynyl alcohol ethoxylate, with a volume ratio of 20:3 in solution B and 23:192 in solution C.

[0091] The acetylamine compound is 2-methyl-3-butyn-2-amine.

[0092] The monoprotic weak acid is boric acid.

[0093] The acetate is ammonium acetate.

[0094] The impurity-removing powder is zinc powder.

[0095] The rest is the same as in Example 1.

[0096] Comparative Example 3

[0097] A bright and environmentally friendly electroless nickel plating solution, comprising solution A, solution B, and solution C. Solution A is prepared from 667 L of water, 450 kg of nickel salt, 17 g of inorganic brightener, and 45 g of first stabilizer. Solution B is prepared from 473.25 kg of buffer, 235 kg of complexing agent, 195.3 kg of reducing agent, 125 L of pH adjuster, 130 g of first stabilizer, 12.58 g of second stabilizer, and 800 mL of organic brightener. Solution C is prepared from 435 L of water, 500 kg of reducing agent, 101 kg of complexing agent, 39 kg of monobasic weak acid, 88 kg of acetate, 100 L of pH adjuster, 60 g of first stabilizer, 90 g of second stabilizer, 2250 mL of organic brightener, and 250 g of impurity removal powder.

[0098] The nickel salt is nickel sulfate.

[0099] The inorganic brightener is tellurium disulfide.

[0100] The first stabilizer is potassium iodate.

[0101] The second stabilizer is 3-isothiourea propane sulfonate inner salt.

[0102] The buffer is ammonium acetate, glacial acetic acid and boric acid, in a mass ratio of 382:83.6:7.65.

[0103] The complexing agents are malic acid and lactic acid, with a mass ratio of 77.5:157.5 in solution B and a mass ratio of 37.1:63.9 in solution C.

[0104] The reducing agent is sodium hypophosphite.

[0105] The pH adjuster is ammonia.

[0106] The organic brightener is sodium 2-ethylhexyl sulfate and propynyl alcohol ethoxylate, with a volume ratio of 20:3 in solution B and 23:192 in solution C.

[0107] The monoprotic weak acid is boric acid.

[0108] The acetate is ammonium acetate.

[0109] The impurity-removing powder is zinc powder.

[0110] The rest is the same as in Example 1.

[0111] Comparative Example 4

[0112] A bright and environmentally friendly electroless nickel plating solution, comprising solution A, solution B, and solution C. Solution A is prepared from 667 L of water, 450 kg of nickel salt, 17 g of inorganic brightener, and 45 g of first stabilizer. Solution B is prepared from 473.25 kg of buffer, 235 kg of complexing agent, 195.3 kg of reducing agent, 125 L of pH adjuster, 130 g of first stabilizer, 12.58 g of second stabilizer, 690 mL of organic brightener, and 70 g of acetylene amine compound. Solution C is prepared from 435 L of water, 500 kg of reducing agent, 101 kg of complexing agent, 39 kg of monoprotic weak acid, 88 kg of acetate, 100 L of pH adjuster, 60 g of first stabilizer, 90 g of second stabilizer, 2150 mL of organic brightener, 100 g of acetylene amine compound, and 250 g of impurity removal powder.

[0113] The nickel salt is nickel sulfate.

[0114] The inorganic brightener is tellurium disulfide.

[0115] The first stabilizer is potassium iodate.

[0116] The second stabilizer is 3-isothiourea propane sulfonate inner salt.

[0117] The buffer is ammonium acetate, glacial acetic acid and boric acid, in a mass ratio of 382:83.6:7.65.

[0118] The complexing agents are malic acid and lactic acid, with a mass ratio of 77.5:157.5 in solution B and a mass ratio of 37.1:63.9 in solution C.

[0119] The reducing agent is sodium hypophosphite.

[0120] The pH adjuster is ammonia.

[0121] The organic brightener is sodium 2-ethylhexyl sulfate and propynyl alcohol ethoxylate, with a volume ratio of 20:3 in solution B and 23:192 in solution C.

[0122] The acetylamine compound is 2-methyl-3-butyn-2-amine.

[0123] The monoprotic weak acid is boric acid.

[0124] The acetate is ammonium acetate.

[0125] The impurity-removing powder is zinc powder.

[0126] The rest is the same as in Example 1.

[0127] Performance Evaluation

[0128] (1) Phosphorus content test: The phosphorus content of the coating was tested by atomic absorption spectrometry (AAS). The steps for testing phosphorus content by atomic absorption spectrometry are as follows: First, the coating on the nickel-plated stainless steel workpiece is peeled off. Then, the mass m of the coating is weighed using a precision balance. Next, the coating is dissolved in nitric acid and the volume is adjusted to 100 mL. According to the test requirements, the solution is diluted to a certain factor. The mass of nickel ions in the diluted solution is tested using an atomic absorption spectrometer, and the total mass m1 of nickel in the peeled coating is calculated based on the dilution factor. The mass content of phosphorus can then be obtained as (m-m1) / m.

[0129] (2) Deposition rate test: The deposition rate of the coating was tested by the weight gain method, and the thickness of the coating was measured by a thickness gauge.

[0130] (3) Hardness test: The hardness of the coating was tested using an HX-1 microhardness tester.

[0131] (4) Neutral Salt Spray Test: The neutral salt spray corrosion test of the coating was conducted according to the method specified in GB / T2423.18-2000. A salt spray tester FR-1202-90 was used to conduct the salt spray resistance test on the nickel-plated workpieces prepared in the examples and comparative examples. (Coating thickness was 8 μm)

[0132] (5) Test of electroless nickel plating cycle (MTO): Electroless nickel plating cycle (MTO) specifically refers to the service life of the solution. One electroless nickel plating cycle is when all the nickel in each liter of plating solution is plated out and then replenished to the original nickel content, which is 1 MTO.

[0133] (6) Brightness test: The brightness of the product is divided into 4 levels, which are graded according to the visual evaluation method (reference standard is based on Zhang Jingshuang, Shi Jinsheng, Shi Lei, et al. Electroplating solution and coating performance test [M]. Beijing: Chemical Industry Press, 2003.8.): Level 1 (mirror bright) The coating is as bright as a mirror, and the facial features and eyebrows can be clearly distinguished; Level 2 (bright) The coating surface is bright, and the facial features and eyebrows can be seen, but the eyebrows are not clear enough; Level 3 (semi-bright) The coating surface is less bright, but the outline of the facial features can be seen, and the eyebrows are blurry; Level 4 (no bright) The coating is basically without luster, and the outline of the facial features cannot be seen.

[0134] Table 1

[0135]

[0136] Table 2

[0137] Example Deposition rate (μm / h) Service life (MTO) Luminous intensity (level) Example 2 29 10 Level 1 Comparative Example 1 30 6 Level 2 Comparative Example 2 28 9 Level 3 Comparative Example 3 28 9 Level 3 Comparative Example 4 27 7 Level 1

[0138] Compared to Example 1, Comparative Example 1 did not add 3-isothiourea propane sulfonate inner salt. Although its deposition rate was faster, the stability of the plating solution was poor and its service life was shorter. In Comparative Example 2, the content of inorganic brightener telluride disulfide was reduced, resulting in larger Ni-P grains, which greatly affected the brightness of the coating. In Comparative Example 3, the acetyleneamine compound 2-methyl-3-butyn-2-amine was not added. Although the content of organic brightener was increased to some extent, the brightness of the coating still dropped sharply. In Comparative Example 4, the amount of acetyleneamine compound 2-methyl-3-butyn-2-amine was increased. Although the brightness of the coating was improved, it would damage the stability of the nickel plating solution and significantly reduce its service life.

Claims

1. A bright and environmentally friendly chemical nickel plating solution, characterized in that, The chemical nickel plating solution comprises solution A, solution B, and solution C. Solution A is prepared from 500-700L of water, 350-500kg of nickel salt, and 30-50g of a first stabilizer. Solution B is prepared from 300-500kg of buffer, 200-400kg of complexing agent, 150-300kg of reducing agent, 100-250L of pH adjuster, 100-200g of a first stabilizer, 5-30g of a second stabilizer, 500-800mL of organic brightener, and 20-60g of acetyleneamine compound. The A solution also includes 10-20g of inorganic brightener; the inorganic brightener is tellurium disulfide; The acetylide compound is 2-methyl-3-butyn-2-amine; The first stabilizer is iodate; The second stabilizer is a thiourea derivative; the thiourea derivative is 3-isothiourea propane sulfonate inner salt; The organic brightener is sodium 2-ethylhexyl sulfate and propynyl alcohol ethoxylate; The raw materials for preparing solution C include 300-500L of water, 400-600kg of reducing agent, 90-120kg of complexing agent, 20-50kg of monoprotic weak acid, 70-100kg of acetate, 80-120L of pH adjuster, 40-70g of primary stabilizer, 60-100g of secondary stabilizer, 1000-3000mL of organic brightener, 60-100g of acetyleneamine compound, and 200-400g of impurity removal powder.

2. The application of the bright and environmentally friendly electroless nickel plating solution according to claim 1 in the electroless nickel plating of workpieces.

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