Nickel pre-plating additive suitable for high area and electroplating method
By developing pre-nickel plating additives suitable for the current density range of 15ASD to 40ASD, the problem of poor stability of the plating layer in the high current density range in traditional technology is solved, and the performance of nickel plating layer and the customization of surface characteristics is achieved.
Patent Information
- Application Number
- CN202510253898.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-05
- Publication Date
- 2025-06-06
AI Technical Summary
In the production of traditional pre-plating steel strips, there are problems such as burning, white mist, and black spots in the high current density zone, resulting in poor stability of the plating and unable to meet the production needs of high-speed and high-zone areas.
A pre-plating nickel electroplating additive suitable for the current density range of 15ASD to 40ASD has been developed, including 10 wt% to 20 wt% brightener, 4 wt% to 8 wt% leveling agent, 10 wt% to 15 wt% softener, 8 wt% to 12 wt% surface cleaner and 1 wt% to 3 wt% wetting agent. By finely managing the types and content of the additives, the gloss, roughness, porosity and other characteristics of the plating layer are controlled.
It effectively solves the problems of burning, white mist and black spots in high current density areas, improves the performance and stability of the nickel plating layer, meets the relevant requirements of battery shell materials, and achieves customized surface characteristics through changes in different additive dosages.
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Abstract
Description
Technical Field
[0001] The invention discloses a pre-nickel plating additive and an electroplating method suitable for high-temperature zones, and is mainly suitable for the field of pre-nickel plating steel strip production. Background Art
[0002] Lithium battery production capacity has entered TWh, and the proportion of cylindrical batteries has continued to rise. 2024 will be the first year of large cylindrical batteries. As an important packaging material for cylindrical battery shells, the market demand for pre-nickel-plated steel strips is expected to reach one million tons in 2030. Among them, electroplating technology is the core technology for the production of pre-nickel-plated steel strips. The traditional pre-nickel-plated steel strip production technology has the characteristics of low current density (only 5 to 8 ASD), and the annual production capacity is only 50,000 to 80,000 tons. Therefore, in order to meet the growing pre-nickel-plated steel strip market, it is urgent to innovate and upgrade the electroplating technology.
[0003] Adding additives to the plating solution can increase cathode polarization through adsorption, resulting in grain refinement, preventing or delaying the spontaneous reaction of the nickel plating solution, enhancing the dispersibility of the plating solution, and improving the internal stress and performance of the coating. Therefore, additives are an essential and important component of a mature nickel plating product.
[0004] However, as the current density increases during the nickel electroplating process (usually higher than 10ASD), traditional additives will spontaneously decompose or lose their activity under high-speed and high-zone deposition and cannot function effectively. This results in scorching, white fog, black spots and other conditions in the high current density zone during the production of pre-nickel-plated steel strips. In order to effectively solve the coating stability of pre-nickel-plated steel strips in high-speed and high-zone production, a pre-nickel electroplating additive suitable for high-speed and high-zone production and its corresponding electroplating method are specially developed. The specific invention is as follows. Summary of the invention
[0005] The problem to be solved by the present invention is to provide a nickel electroplating additive and a corresponding electroplating method, which can meet the electroplating requirements in the high current density range of 15ASD to 40ASD, effectively solve the problems of burning, white fog, black spots, etc. that exist in the high-zone electroplating of traditional additives, improve the performance of the nickel plating layer, effectively adjust the glossiness, and meet the relevant requirements of battery shell materials.
[0006] In order to solve the above-mentioned high-zone electroplating problem for the production of pre-nickel-plated steel strips, the present invention develops a pre-nickel plating additive suitable for high zones and a corresponding electroplating method, which are as follows:
[0007] The invention discloses a pre-nickel plating additive suitable for a high current density range (15ASD to 40ASD), comprising five main functional additives: 10wt% to 20wt% of a brightener, 4wt% to 8wt% of a leveler, 10wt% to 15wt% of a softener, 8wt% to 12wt% of a surface cleaner and 1wt% to 3wt% of a wetting agent.
[0008] The brightener mainly includes a mixture of one or more of propane pyridinium sulfonate (PPS), sodium allyl sulfonate aqueous solution (ALS), trichloroacetaldehyde hydrate (TCA), 1,4-butynediol (BOZ), butynediol ethyl oxide (BEO). Preferred are propane pyridinium sulfonate (PPS), sodium allyl sulfonate aqueous solution (ALS), trichloroacetaldehyde hydrate (TCA).
[0009] The leveler mainly comprises a mixture of one or more of propargyl alcohol ethyl oxide (PME), propargyl alcohol propoxy compound (PAP), butynediol propoxy compound (BMP), N,N-diethyl propargylamine formate (PABS), and hydroxypropanesulfonic acid pyridinium salt (PPS-OH). Among them, hydroxypropanesulfonic acid pyridinium salt (PPS-OH) and butynediol propoxy compound (BMP) are preferred.
[0010] The softener mainly includes one or more mixtures of sodium allyl sulfonate (SAS), N,N-diethyl propargylamine (DEP), propargyl-3-sulfopropyl ether sodium salt (POPS), among which sodium allyl sulfonate (SAS) is preferred.
[0011] The surface cleaning agent mainly comprises a mixture of one or more substances of sodium gluconate, sodium benzoate, sodium salicylate, sodium acetate, sodium hypophosphite, and 2,5-dimethyl-3-hexyne-2,5-diol (HD-M). Among them, sodium gluconate, sodium benzoate, sodium salicylate, sodium acetate, and sodium hypophosphite are preferred.
[0012] The wetting agent mainly includes a mixture of one or more substances of 2-ethylhexyl sulfate sodium salt (TC-EHS), dihexyl sulfonated succinate sodium salt, and mono(2-ethylhexyl) sulfate sodium salt. Among them, 2-ethylhexyl sulfate sodium salt (TC-EHS) and dihexyl sulfonated succinate sodium salt are preferred.
[0013] The corresponding electroplating method for the above-mentioned pre-nickel plating additive for high-zone includes: the plating solution adopts Watt plating solution, which includes 250g / L to 350g / L nickel sulfate, 40g / L to 50g / L nickel chloride, and 40g / L to 50g / L boric acid. The plating solution temperature is 60℃ to 70℃, the pH value is 3.8 to 4.2, the substrate spacing between the cathode and anode is 4cm to 6cm, the current density is 15ASD to 40ASD, and the solution conductivity is 35mS / cm to 42mS / cm.
[0014] Among them, in the above-mentioned Watt plating solution, the additives added are as follows: brightener 2-4mL / L, leveler 3-5mL / L, softener 3-5mL / L, surface cleaner 3-5mL / L and wetting agent 1.5-3mL / L.
[0015] At the same time, the amount of different additives determines the characteristics of the coating. Among them, the brightener determines the gloss of the coating, the leveler determines the surface roughness of the coating, and the softener, surfactant, and wetting agent determine the porosity and number of blue spots of the coating.
[0016] The beneficial effects of the present invention are as follows:
[0017] 1. The pre-nickel plating additive and corresponding electroplating method suitable for high-speed zone provided by the present invention can meet the high-speed high-speed zone production requirements of pre-nickel plated steel strips, and the nickel plating layer does not have white fog, burning, black spots and the like in the electroplating range of 15ASD to 40ASD.
[0018] The additives of the present invention effectively realize the refined management of additives by first controlling the type and content of additives, and then controlling the amount of additives added, and then accurately controlling the surface gloss, roughness, porosity, blue spots and other characteristics of the coating by changing the amount of different types of additives. It effectively meets the needs of downstream battery shell materials, and can customize the surface gloss and roughness of pre-nickel-plated steel strip materials by changing different types of additives. DETAILED DESCRIPTION
[0019] To make the purpose, technical scheme and advantages of the present invention clearer, the present invention is described in further detail below. The content of each component of the nickel plating additive in wt% represents the mass of a certain component per 100g of the additive solution. The dosage unit of the nickel plating additive for preparing the bath solution is mL / L, which represents the volume of the additive per liter of the nickel bath solution.
[0020] The invention provides a pre-nickel plating additive suitable for high-temperature zones, comprising five main functional additives: 10wt% to 20wt% of a brightener, 4wt% to 8wt% of a leveler, 10wt% to 15wt% of a softener, 8wt% to 12wt% of a surface cleaner and 1wt% to 3wt% of a wetting agent.
[0021] Five types of additives are divided according to their main functions. Essentially, they all increase cathode polarization through adsorption, leading to grain refinement and interaction, thereby improving the quality of the coating. The main mechanism is explained as (1) grain refinement. It is generally believed that the brightening effect of the coating is related to the crystallization of the coating particles. Generally, the finer the grains, the brighter the coating. Brighteners have the effect of significantly refining the crystallization of the coating. The reasons are as follows: First, the addition of brighteners increases the polarization of the cathode, which increases hydrogen evolution, thereby causing the pH value of the solution near the cathode to rise. The interaction between nickel ions and additives reduces nickel ions near the cathode, thereby slowing down crystal growth, increasing crystal nuclei, and refining the coating crystals; second, due to the adsorption of additives on the cathode surface, the cathode film resistance increases, hindering the discharge reaction of nickel ions, thereby inhibiting the growth of coating crystals and refining the grains; third, the additives form ligand compounds with nickel ions in the cathode film, which prevents the discharge reaction of nickel ions and promotes the refinement of coating crystals. (2) Directed arrangement effect. The adsorption of brightener on the cathode surface hinders the growth of crystals along the right angle direction of the substrate, so that the grains deposited on the cathode are regularly arranged parallel to the substrate surface, that is, a layered structure is produced, which is conducive to the formation of a smooth surface and the directional emission of light, making the coating bright.
[0022] In addition, the matching electroplating method is based on Watt plating solution. It includes 250g / L~350g / L nickel sulfate, 40g / L~50g / L nickel chloride, and 40g / L~50g / L boric acid. The plating temperature is 60℃~70℃, the pH value is 3.8~4.2, the substrate spacing between the cathode and anode is 4cm~6cm, and the current density is 15ASD~40ASD. The main functions of each part are as follows:
[0023] Nickel sulfate is the main salt in the nickel plating solution and plays a role in supplying Ni 2+ The role of industrial nickel sulfate is NiSO 4 .7H 2 0 and NiS0 4 6H 20, the former has a nickel content of 20.9%, while the latter has a nickel content of 22.3%. The main salt of the nickel plating electrolyte can be nickel sulfate and nickel chloride, of which nickel sulfate is widely used because of its high solubility, high purity and low price; the electrolyte prepared with nickel chloride as the main salt has better dispersibility and conductivity than nickel sulfate, but too high a chloride ion content will increase the stress in the coating and aggravate the corrosion of the plant and equipment. The content of nickel salt can vary in a large range, generally controlled at 250-350g / L. When the nickel salt content is low, the electrolyte has good dispersibility, the coating is finely crystallized and easy to polish, but the deposition speed is slow and the cathode current efficiency is low; when the content is high, the nickel ion content in the plating solution is relatively stable, which is conducive to improving the cathode current efficiency, allowing a high current density, and a fast deposition speed, which is suitable for rapid nickel plating. When the content is too high, the cathode polarization decreases, the dispersibility deteriorates, and the electrolyte has a large carry-out loss.
[0024] Nickel chloride is an anode activator. In the nickel plating electrolyte, if no chloride ions are added or the chloride ion content is insufficient, the anode is prone to passivation. Anode passivation is extremely unfavorable to electroplating production. After adding or appropriately supplementing nickel chloride or sodium chloride, Cl- can be adsorbed on the anode surface, reducing the anode potential, and the depolarization effect is very significant. Chloride ions prevent the oxidation of divalent nickel ions into trivalent nickel ions, thereby preventing the formation of a passivation film. In the fast nickel plating solution, nickel chloride is used as an anode activator.
[0025] Boric acid is a buffer in nickel plating electrolyte. For each electrolyte, under certain conditions, the pH value must be maintained within a certain range to ensure smooth electroplating. Boric acid plays a role in stabilizing the pH value. During the electroplating process, H+ discharge in the electrolyte will reduce the acidity of the electrolyte. At this time, boric acid hydrolyzes to ensure that the pH value remains within the process range.
[0026] The present invention is further described below in conjunction with specific embodiments.
[0027] Example 1
[0028] A pre-nickel plating additive suitable for high-altitude areas includes a brightener of 13wt% propane pyridinium sulfonate (PPS) and 2wt% trichloroacetaldehyde hydrate (TCA) (the two together account for 15wt%), a leveler of 6wt% propargyl alcohol ethyl oxide (PME), a softener of 12wt% sodium allyl sulfonate (SAS), a surface cleaner of 10wt% sodium benzoate and a wetting agent of 2wt% 2-ethylhexyl sulfate sodium salt (TC-EHS).
[0029] A corresponding electroplating method includes: 300g / L nickel sulfate, 45g / L nickel chloride, 45g / L boric acid, fully dissolved to form a Watt plating solution, the solution conductivity is 40mS / cm. Take 3mL / L of brightener, 4mL / L of leveler, 4mL / L of softener, 4mL / L of surface cleaner and 2mL / L of wetting agent. Slowly add them into the Watt plating solution. The plating solution temperature is 65°C, the pH value is 4, the substrate spacing between the cathode and cathode is 5cm, the current density is 30ASD, and the electroplating time is 30s to obtain a pre-nickel plating layer.
[0030] Example 2
[0031] A pre-nickel plating additive suitable for high-altitude areas includes 12 wt% of propane pyridinium sulfonate (PPS) as a brightener, 6 wt% of propargyl alcohol propoxy compound (PAP) as a leveler, 13 wt% of propargyl-3-sulfopropyl ether sodium salt (POPS) as a softener, 10 wt% of sodium salicylate as a surface cleaner and 3 wt% of dihexyl sulfonated succinate sodium salt.
[0032] A corresponding electroplating method includes: 350g / L nickel sulfate, 50g / L nickel chloride, 50g / L boric acid, fully dissolved to form a Watt plating solution, and the solution conductivity is 42mS / cm. . Take 4mL / L of brightener, 4mL / L of leveler, 5mL / L of softener, 4mL / L of surface cleaner and 2mL / L of wetting agent. Slowly add them into the Watt plating solution. The plating solution temperature is 65℃, the pH value is 3.8, the substrate spacing between the cathode and anode is 5cm, the current density is 25ASD, and the electroplating time is 30s to obtain a pre-nickel plating layer.
[0033] Example 3
[0034] A pre-nickel plating additive suitable for high-altitude areas includes 10wt% butynediol ethyl oxide (BEO) as a brightener, 4wt% hydroxypropane sulfonic acid pyridinium salt (PPS-OH) as a leveler, 10wt% sodium allyl sulfonate (SAS) as a softener, 8wt% sodium gluconate as a surface cleaner and 1wt% mono(2-ethylhexyl) sulfate sodium salt.
[0035] A corresponding electroplating method includes: 300g / L nickel sulfate, 50g / L nickel chloride, 50g / L boric acid, fully dissolved to form a Watt plating solution, and the solution conductivity is 41mS / cm. . Take 4mL / L of brightener, 5mL / L of leveler, 5mL / L of softener, 5mL / L of surface cleaner and 3mL / L of wetting agent. Slowly add them into the Watt plating solution. The plating solution temperature is 70℃, the pH value is 3.8, the substrate spacing between the cathode and anode is 5cm, the current density is 30ASD, and the electroplating time is 30s to obtain a pre-nickel plating layer.
[0036] Example 4
[0037] The invention discloses a pre-nickel plating additive suitable for high-altitude areas, comprising a brightener of 20 wt% propane pyridinium sulfonate (PPS), a leveler of 8 wt% propynyl alcohol ethyl oxide (PME), a softener of 15 wt% sodium allyl sulfonate (SAS), a surface cleaner of 12 wt% sodium benzoate and a wetting agent of 3 wt% 2-ethylhexyl sulfate sodium salt (TC-EHS).
[0038] A corresponding electroplating method includes: 300g / L nickel sulfate, 45g / L nickel chloride, 45g / L boric acid, fully dissolved to form a Watt plating solution, the solution conductivity is 40mS / cm. Take 2mL / L of brightener, 3mL / L of leveler, 3mL / L of softener, 3mL / L of surface cleaner and 1.5mL / L of wetting agent. Slowly add them into the Watt plating solution. The plating solution temperature is 65°C, the pH value is 4, the substrate spacing between the cathode and cathode is 5cm, the current density is 30ASD, and the electroplating time is 30s to obtain a pre-nickel plating layer.
[0039] Example 5
[0040] A pre-nickel plating additive suitable for high-altitude areas includes a brightener of 15wt% propane pyridinium sulfonate (PPS) and 5wt% trichloroacetaldehyde hydrate (TCA) (the two together account for 20wt%), a leveler of 4wt% hydroxypropane pyridinium sulfonate (PPS-OH) and 4wt% butynediol propoxylate (BMP) (the two together account for 8wt%), a softener of 15wt% sodium allyl sulfonate (SAS), a surface cleaner of 12wt% sodium benzoate and a wetting agent of 3wt% 2-ethylhexyl sulfate sodium salt (TC-EHS).
[0041] A corresponding electroplating method includes: 300g / L nickel sulfate, 45g / L nickel chloride, 45g / L boric acid, fully dissolved to form a Watt plating solution, the solution conductivity is 40mS / cm. Take 2mL / L of brightener, 3mL / L of leveler, 3mL / L of softener, 3mL / L of surface cleaner and 1.5mL / L of wetting agent. Slowly add them into the Watt plating solution. The plating solution temperature is 65°C, the pH value is 4, the substrate spacing between the cathode and cathode is 5cm, the current density is 30ASD, and the electroplating time is 30s to obtain a pre-nickel plating layer.
[0042] Example 6
[0043] A pre-nickel plating additive suitable for high-altitude areas, comprising a brightener of 15wt% propane pyridinium sulfonate (PPS), a leveler of 6wt% hydroxypropane pyridinium sulfonate (PPS-OH), a softener of 12wt% sodium allyl sulfonate (SAS), a surface cleaner of 6wt% sodium benzoate and 6wt% sodium salicylate (the two together account for 12wt%), and a wetting agent of 1.5wt% 2-ethylhexyl sulfate sodium salt (TC-EHS) and 1.5wt% mono(2-ethylhexyl) sulfate sodium salt (the two together account for 3wt%).
[0044] A corresponding electroplating method includes: 300g / L nickel sulfate, 45g / L nickel chloride, 45g / L boric acid, fully dissolved to form a Watt plating solution, the solution conductivity is 40mS / cm. Take 2mL / L of brightener, 3mL / L of leveler, 3mL / L of softener, 3mL / L of surface cleaner and 1.5mL / L of wetting agent. Slowly add them into the Watt plating solution. The plating solution temperature is 65°C, the pH value is 4, the substrate spacing between the cathode and cathode is 5cm, the current density is 30ASD, and the electroplating time is 30s to obtain a pre-nickel plating layer.
[0045] Example 7
[0046] A pre-nickel plating additive suitable for high-altitude areas, comprising a brightener of 15wt% propane pyridinium sulfonate (PPS), a leveler of 6wt% hydroxypropane pyridinium sulfonate (PPS-OH), a softener of 12wt% sodium allyl sulfonate (SAS), a surface cleaner of 6wt% sodium benzoate and 6wt% sodium salicylate (the two together account for 12wt%), and a wetting agent of 1.5wt% 2-ethylhexyl sulfate sodium salt (TC-EHS) and 1.5wt% mono(2-ethylhexyl) sulfate sodium salt (the two together account for 3wt%).
[0047] A corresponding electroplating method includes: 250g / L nickel sulfate, 40g / L nickel chloride, 40g / L boric acid, fully dissolved to form a Watt plating solution, the solution conductivity is 38mS / cm. Take 2mL / L of brightener, 3mL / L of leveler, 3mL / L of softener, 3mL / L of surface cleaner and 1.5mL / L of wetting agent. Slowly add them into the Watt plating solution. The plating solution temperature is 65°C, the pH value is 4, the substrate spacing between the cathode and anode is 5cm, the current density is 15ASD, and the electroplating time is 30s to obtain a pre-nickel plating layer.
[0048] Example 8
[0049] A pre-nickel plating additive suitable for high-altitude areas includes a brightener of 13wt% propane pyridinium sulfonate (PPS) and 2wt% trichloroacetaldehyde hydrate (TCA) (the two together account for 15wt%), a leveler of 6wt% propargyl alcohol ethyl oxide (PME), a softener of 12wt% sodium allyl sulfonate (SAS), a surface cleaner of 10wt% sodium benzoate and a wetting agent of 2wt% 2-ethylhexyl sulfate sodium salt (TC-EHS).
[0050] A corresponding electroplating method includes: 300g / L nickel sulfate, 45g / L nickel chloride, 45g / L boric acid, fully dissolved to form a Watt plating solution, the solution conductivity is 40mS / cm. Take 3mL / L of brightener, 4mL / L of leveler, 4mL / L of softener, 4mL / L of surface cleaner and 2mL / L of wetting agent. Slowly add them into the Watt plating solution. The plating solution temperature is 65°C, the pH value is 4, the substrate spacing between the cathode and anode is 5cm, the current density is 40ASD, and the electroplating time is 30s to obtain a pre-nickel plating layer.
[0051] Comparative Example 1
[0052] A pre-nickel plating additive suitable for high-altitude areas includes a brightener of 13wt% propane pyridinium sulfonate (PPS) and 2wt% trichloroacetaldehyde hydrate (TCA) (the two together account for 15wt%), a leveler of 6wt% propargyl alcohol ethyl oxide (PME), a softener of 12wt% sodium allyl sulfonate (SAS), a surface cleaner of 10wt% sodium benzoate and a wetting agent of 2wt% 2-ethylhexyl sulfate sodium salt (TC-EHS).
[0053] A corresponding electroplating method includes: 300g / L nickel sulfate, 45g / L nickel chloride, 45g / L boric acid, fully dissolved to form a Watt plating solution, the solution conductivity is 40mS / cm. Take 3mL / L of brightener, 4mL / L of leveler, 4mL / L of softener, 4mL / L of surface cleaner and 2mL / L of wetting agent. Slowly add them into the Watt plating solution. The plating solution temperature is 65°C, the pH value is 4, the substrate spacing between the cathode and anode is 5cm, the current density is 5ASD, and the electroplating time is 30s to obtain a pre-nickel plating layer.
[0054] Comparative Example 2
[0055] A pre-nickel plating additive suitable for high-altitude areas includes a brightener of 8wt% propane pyridinium sulfonate (PPS), a leveler of 2wt% propynyl alcohol ethyl oxide (PME), a softener of 8wt% sodium allyl sulfonate (SAS), a surface cleaner of 6wt% sodium benzoate and a wetting agent of 0.8wt% 2-ethylhexyl sulfate sodium salt (TC-EHS).
[0056] A corresponding electroplating method includes: 300g / L nickel sulfate, 45g / L nickel chloride, 45g / L boric acid, fully dissolved to form a Watt plating solution, the solution conductivity is 40mS / cm. Take 3mL / L of brightener, 4mL / L of leveler, 4mL / L of softener, 4mL / L of surface cleaner and 2mL / L of wetting agent. Slowly add them into the Watt plating solution. The plating solution temperature is 65°C, the pH value is 4, the substrate spacing between the cathode and cathode is 5cm, the current density is 30ASD, and the electroplating time is 30s to obtain a pre-nickel plating layer.
[0057] Comparative Example 3
[0058] A pre-nickel plating additive suitable for high-altitude areas includes a brightener of 22 wt% propane pyridinium sulfonate (PPS), a leveler of 10 wt% propynyl alcohol ethyl oxide (PME), a softener of 16 wt% sodium allyl sulfonate (SAS), a surface cleaner of 14 wt% sodium benzoate and a wetting agent of 4 wt% 2-ethylhexyl sulfate sodium salt (TC-EHS).
[0059] A corresponding electroplating method includes: 400g / L nickel sulfate, 50g / L nickel chloride, 50g / L boric acid, fully dissolved to form a Watt plating solution, the solution conductivity is 45mS / cm. Take 3mL / L of brightener, 4mL / L of leveler, 4mL / L of softener, 4mL / L of surface cleaner and 2mL / L of wetting agent. Slowly add them into the Watt plating solution. The plating solution temperature is 65°C, the pH value is 4, the substrate spacing between the cathode and cathode is 5cm, the current density is 40ASD, and the electroplating time is 30s to obtain a pre-nickel plating layer.
[0060] The pre-nickel-plated steel strips and the mixed solution obtained in Examples 1-8 and Comparative Examples 1-3 were tested as follows. The results are shown in Table 1.
[0061] Dispersion ability test: The far-near cathode method is used for determination. The Haring trough is selected as the measuring trough, and the internal dimensions are 150mm*50mm*70mm. The cathode is a copper sheet with a thickness of 0.5mm and a working surface size of 50mm*50mm; the anode is a nickel plate with holes for electroplating. The test current density is 20ASD, and the electroplating time is 5min.
[0062] The formula for calculating the dispersibility of the plating solution is:
[0063]
[0064] (T represents the dispersion capacity (%); K represents the distance ratio between the near and far cathode and the anode, which can be 2; M near represents the weight gain near the cathode (g); M far represents the weight gain far from the cathode (g))
[0065] Throwing capacity test: Determined by inner hole method. The cathode is a copper tube with an inner diameter of 110mm and a tube length of 50mm, and one end is closed. During the test, the distance between the tube mouth and the anode is fixed at 80mm, the test current is 15ASD, and the electroplating time is 10min. The calculation formula is: Throwing capacity = inner hole coating length / tube length (the result is expressed as a percentage).
[0066] Porosity test: Porosity represents the size of the gaps in the coating, which is related to the performance of the coating. The blue dot test is used, referring to the GB5935-86 test standard. The details are as follows.
[0067] 10g / L potassium ferrocyanide solution and 20g / L sodium chloride solution are used as corrosion solutions for porosity testing. The operation is as follows: After degreasing and wiping the surface of the coating, use filter paper soaked in corrosion solution to stick to the surface of the coating, and there should be no gap between the two. Use a glass rod or a cotton swab to dip into the corrosion solution to fully wet the surface of the filter paper, and replenish the solution every 1min. After 5min, peel off the filter paper, rinse it with distilled water and dry it, and record the number of pore points. Place it on a clean glass plate to dry, and count the number of blue dots. Substitute into the formula to calculate the porosity. Porosity = Number of spots / measured area (cm -2 )
[0068] When calculating the number of porosity, the spot diameter can be converted as follows: If the diameter of the corrosion spot is less than 1mm, each spot is calculated as 1 pore; if it is greater than 1mm and less than 3mm, each spot is calculated as 3 pores; if it is greater than 3mm and less than 5mm, each spot is calculated as 10 pores.
[0069] Microhardness (HV): The microhardness of the coating was measured using a HV-71 microhardness tester with a load of 100 g.
[0070] Wear resistance test: On an M5-10 wear tester, add a load of 2 kg to the heat-treated sample for 6 hours at a speed of 10 r / min and a stroke of 8 mm. The weight loss of the test sample is then converted into wear loss (mg·h -1 cm -1 ).
[0071] Corrosion test: The plated workpiece is immersed in 10% hydrochloric acid solution for 72 hours, and then its weight loss is measured and converted into corrosion rate (mg·h -1 cm -1 ).
[0072] Roughness and glossiness test: Roughness test and glossiness test were carried out using a roughness tester (MarSurfPS10, MAHR, German) and a glossiness tester (LS192, Linshang, China), respectively.
[0073] Table 1 Test results of coating
[0074]
[0075] As can be seen from Table 1, the deep plating ability and dispersibility of the nickel plating solution of Examples 1-8 are significantly higher than those of Comparative Examples 1-3, so the additive formula of the present invention can effectively improve the deep plating ability and dispersibility of the solution. In addition, the surface morphology, glossiness, roughness, hardness, porosity, wear resistance and corrosion resistance of Examples 1-8 are higher than those of Comparative Examples 1-3, which shows that the additive and electroplating method of the present invention have obvious electroplating effects for high areas of 15ASD to 40ASD. It can effectively reduce the porosity of the coating, adjust the surface glossiness and roughness of the coating, and improve the wear resistance and corrosion resistance of the coating.
[0076] The above embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.
Claims
1. A pre-nickel plating additive suitable for high-temperature areas, characterized in that: include: 10wt% to 20wt% of brightener, 4wt% to 8wt% of leveler, 10wt% to 15wt% of softener, 8wt% to 12wt% of surface cleaner and 1wt% to 3wt% of wetting agent, five main functional additives.
2. A pre-nickel plating additive suitable for high-temperature zones as claimed in claim 1, characterized in that The brightener mainly includes a mixture of one or more of propane pyridinium sulfonate (PPS), sodium allyl sulfonate aqueous solution (ALS), trichloroacetaldehyde hydrate (TCA), 1,4-butynediol (BOZ), butynediol ethyl oxide (BEO). Among them, propane pyridinium sulfonate (PPS), sodium allyl sulfonate aqueous solution (ALS), trichloroacetaldehyde hydrate (TCA) are preferred.
3. A pre-nickel plating additive suitable for high-temperature zones as claimed in claim 1, characterized in that The leveler mainly comprises a mixture of one or more substances of propargyl alcohol ethyl oxide (PME), propargyl alcohol propoxy compound (PAP), butynediol propoxy compound (BMP), N,N-diethyl propargylamine formate (PABS), and hydroxypropanesulfonic acid pyridinium salt (PPS-OH). Among them, hydroxypropanesulfonic acid pyridinium salt (PPS-OH) and butynediol propoxy compound (BMP) are preferred.
4. A pre-nickel plating additive suitable for high-temperature zones as claimed in claim 1, characterized in that The softener mainly includes a mixture of one or more substances of sodium allyl sulfonate (SAS), N,N-diethylpropargylamine (DEP), propargyl-3-sulfopropyl ether sodium salt (POPS), among which sodium allyl sulfonate (SAS) is preferred.
5. A pre-nickel plating additive suitable for high-temperature zones as claimed in claim 1, characterized in that The surface cleaning agent mainly comprises a mixture of one or more substances of sodium gluconate, sodium benzoate, sodium salicylate, sodium acetate, sodium hypophosphite, 2,5-dimethyl-3-hexyne-2,5-diol (HD-M), wherein sodium gluconate, sodium benzoate, sodium salicylate, sodium acetate, sodium hypophosphite are preferred.
6. A pre-nickel plating additive suitable for high-temperature zones as claimed in claim 1, characterized in that The wetting agent mainly includes a mixture of one or more substances of 2-ethylhexyl sulfate sodium salt (TC-EHS), dihexyl sulfonated succinate sodium salt, and mono(2-ethylhexyl) sulfate sodium salt. Among them, 2-ethylhexyl sulfate sodium salt (TC-EHS) and dihexyl sulfonated succinate sodium salt are preferred.
7. The electroplating method of the pre-nickel plating additive suitable for high-zone as claimed in claim 1, characterized in that: include: The plating solution is Watt plating solution, which includes 250g / L to 350g / L nickel sulfate, 40g / L to 50g / L nickel chloride, and 40g / L to 50g / L boric acid. The plating solution temperature is 60°C to 70°C, the pH value is 3.8 to 4.2, the substrate spacing between the cathode and anode is 4cm to 6cm, the current density is 15ASD to 40ASD, and the solution conductivity is 35mS / cm to 42mS / cm.
8. The electroplating method of the pre-nickel plating additive suitable for high-zone as claimed in claim 7, characterized in that: In the above-mentioned Watt plating solution, the additives added are as follows: brightener 2-4 mL / L, leveler 3-5 mL / L, softener 3-5 mL / L, surface cleaner 3-5 mL / L and wetting agent 1.5-3 mL / L.
9. The electroplating method of the pre-nickel plating additive suitable for high-zone as claimed in claim 8, characterized in that: The amount of different additives determines the characteristics of the coating. Among them, the brightener determines the gloss of the coating, the leveler determines the surface roughness of the coating, and the softener, surfactant, and wetting agent determine the porosity and number of blue spots of the coating.