Chemical nickel plating solution capable of improving plating uniformity, preparation method and use method

Abstract

The invention discloses a chemical nickel plating solution capable of improving the uniformity of the plating layer, a preparation method and a use method thereof, and belongs to the technical field of chemical nickel plating solution. Each liter of the chemical nickel plating solution comprises the following components: nickel salt: 18.3-33.2 g; reducing agent: 8.5-9.8 g; complexing agent: 12.5-14.3 g; buffer: 11.2-28.7 g; colloidal stabilizer: 5.3-8.8 g; the balance is deionized water; the present invention adopts TiO2, complexing agent A and complexing agent B to prepare a composite complexing agent, TiO2 absorbs ultraviolet light energy to generate electron-hole pairs, the electrostatic repulsion between particles is increased, thereby reducing agglomeration and promoting the dispersion of TiO2, TiO2 is externally coated with complexing agent A and complexing agent B, thereby promoting the stability of the components of the composite complexing agent; after the subsequent addition of a colloidal stabilizer, the colloidal stabilizer can be adsorbed on the surface of the TiO2 particles, and the colloidal stabilizer can form a layer of polymer protective film around the TiO2 particles, further preventing the particles from approaching each other, promoting the uniform dispersion of the nickel plating solution, and thus facilitating the uniformity of the subsequent nickel plating layer.

Description

Technical Field

[0001] The invention relates to the technical field of chemical nickel plating solutions, and in particular to a chemical nickel plating solution capable of improving the uniformity of a plating layer, a preparation method and a use method thereof. Background Art

[0002] Electroless nickel plating is a method of depositing a nickel layer on a metal or non-metal surface using a chemical reaction without an applied current. It is commonly used in the automotive, electronics, aerospace, and machinery manufacturing industries.

[0003] The ingredients of chemical nickel plating solution generally include nickel salts, reducing agents, chelating agents, buffers, surfactants, stabilizers, etc. Common nickel salts include nickel sulfate, nickel chloride, nickel acetate, etc., reducing agents include sodium hypophosphite, sodium borohydride, etc., chelating agents include citric acid, malic acid, etc., buffers include acetic acid-sodium acetate buffer system, etc., surfactants include non-ionic surfactants such as polyethylene glycol, anionic surfactants, etc., stabilizers include heavy metal salts (such as lead acetate), etc.

[0004] However, the use of heavy metal salt stabilizers makes it difficult to treat wastewater containing heavy metals and is environmentally unfriendly. Furthermore, the dispersibility of the plating solution needs to be further improved to achieve a uniform coating on the substrate.

[0005] Based on this, the present invention designs a chemical nickel plating solution, a preparation method and a use method that can improve the uniformity of the plating layer to solve the above problems. Summary of the Invention

[0006] In view of the above-mentioned shortcomings of the prior art, the present invention provides a chemical nickel plating solution, a preparation method and a use method thereof that can improve the uniformity of the plating layer.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0008] The chemical nickel plating solution can improve the uniformity of the plating layer. Each liter of chemical nickel plating solution includes the following components:

[0009] Nickel salt: 18.3-33.2 g;

[0010] Reducing agent: 8.5-9.8 g;

[0011] Complex complexing agent: 12.5-14.3 g;

[0012] Buffer: 11.2-28.7 g;

[0013] Colloidal stabilizer: 5.3-8.8 g;

[0014] The balance is deionized water;

[0015] The pH value of the chemical nickel plating solution is 6.5-7.1;

[0016] The composite complexing agent is prepared by mixing complexing agent A, complexing agent B and TiO2;

[0017] The preparation method of the composite complexing agent is:

[0018] Step (1), pre-irradiating TiO2 with ultraviolet light, with an illumination intensity of 22-35 mW / cm2 and an irradiation time of 3-5 minutes;

[0019] Step (2), mixing and stirring the complexing agent A and the complexing agent B to obtain a mixed solution;

[0020] Step (3): adding TiO2 to the mixed solution, and continuing to irradiate the mixed solution with ultraviolet light at an illumination intensity of 40-45 mW / cm2 for 8-12 minutes, and drying for later use.

[0021] Furthermore, the nickel salt is nickel sulfate, nickel chloride or nickel acetate.

[0022] Furthermore, the reducing agent is sodium hypophosphite.

[0023] Furthermore, the composite complexing agent is prepared by mixing complexing agent A, complexing agent B and TiO2 in a mass ratio of 3-5:1-2:0.05-0.1.

[0024] Furthermore, the complexing agent A is obtained by dissolving disodium ethylenediaminetetraacetate and tartaric acid in deionized water, and the mass ratio of disodium ethylenediaminetetraacetate, tartaric acid and deionized water is 1-2:2-5:6-10.

[0025] Furthermore, the complexing agent B is obtained by dissolving carboxymethyl cellulose and magnesium ascorbyl phosphate in deionized water, and the mass ratio of carboxymethyl cellulose, magnesium ascorbyl phosphate and deionized water is 3-5:2-3:100-180.

[0026] Furthermore, in step (2), the complexing agent A and the complexing agent B are mixed and stirred at 32-36° C. to obtain a mixed solution.

[0027] Furthermore, the colloidal stabilizer is obtained by dissolving xylitol and potassium iodide in deionized water, and the mass ratio of xylitol, potassium iodide and deionized water is 3-5:10:10-12.

[0028] In order to better achieve the purpose of the present invention, the present invention also provides a method for preparing a chemical nickel plating solution that can improve the uniformity of the plating layer, comprising the following steps:

[0029] Step a, adding 80% by weight of deionized water into a container, then slowly adding nickel salt into the deionized water while stirring at a stirring speed of 130-150 rpm to uniformly distribute the nickel ions in the solution;

[0030] Step b, adding a complexing agent to the container, also slowly adding and stirring, controlling the stirring speed at 200-255 rpm to fully complex the complexing agent with the nickel ions;

[0031] Step c, then add the reducing agent and stir for 25-30 minutes at a stirring speed of 180-220 rpm;

[0032] Step d, then add the colloidal stabilizer and stir for 10-15 minutes at a stirring speed of 200-250 rpm;

[0033] Step e, pre-irradiating the obtained solution with ultraviolet light at an intensity of 40-45 mW / cm2 for 10-15 minutes;

[0034] Step f: adjusting the pH value to 6.5-7.1 with a buffer, and adding the balance of deionized water to obtain a chemical nickel plating solution that can improve the uniformity of the plating layer.

[0035] In order to better achieve the purpose of the present invention, the present invention also provides a method for using a chemical nickel plating solution that can improve the uniformity of the plating layer. The substrate to be plated is immersed in the chemical nickel plating solution, the plating temperature is controlled to be 85-90°C, and the substrate is taken out after the plating layer reaches a certain thickness.

[0036] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention uses colloidal stabilizers (xylitol and potassium iodide) to replace heavy metal salt stabilizers, thereby increasing environmental friendliness.

[0037] 2. The nickel plating layer of the present invention has good uniformity and a uniform and smooth appearance. A composite complexing agent is prepared by using TiO2, complexing agent A and complexing agent B. TiO2 absorbs ultraviolet light energy to generate electron-hole pairs, which increases the electrostatic repulsion between particles, thereby reducing agglomeration and promoting the dispersion of TiO2. The complexing agent A and complexing agent B are coated on the outside of TiO2, thereby promoting the stability of the components of the composite complexing agent and improving the complexing effect of the composite complexing agent. After the colloidal stabilizer is subsequently added, the colloidal stabilizer can be adsorbed on the surface of the TiO2 particles. At the same time, the colloidal stabilizer can form a layer of polymer protective film around the TiO2 particles, further preventing the particles from approaching each other, promoting the uniform dispersion of the nickel plating solution, thereby facilitating the uniformity of the subsequent nickel plating layer and enhancing the bonding force between the coating and the workpiece to be plated. DETAILED DESCRIPTION

[0038] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0039] Example 1: A method for preparing a chemical nickel plating solution capable of improving the uniformity of a plating layer, comprising the following steps:

[0040] Step a, preparing a composite complexing agent;

[0041] Step (1), pre-irradiating TiO2 with ultraviolet light, with an illumination intensity of 22 mW / cm2 and an irradiation time of 3 minutes;

[0042] Step (2): complexing agent A is prepared by dissolving 10 g of disodium ethylenediaminetetraacetic acid and 50 g of tartaric acid in 100 ml of deionized water; complexing agent B is prepared by dissolving 30 g of carboxymethyl cellulose and 20 g of magnesium ascorbyl phosphate in 1000 ml of deionized water; 30 g of complexing agent A and 10 g of complexing agent B are mixed and stirred at 32° C. to obtain a mixed solution;

[0043] Step (3), adding 0.5 g of TiO2 to the mixed solution, and continuing to irradiate the mixed solution with ultraviolet light at an intensity of 40 mW / cm2 for 8 minutes, and drying for later use;

[0044] Step b, preparing a colloidal stabilizer: dissolving 30 g of xylitol and 100 g of potassium iodide in 100 ml of deionized water;

[0045] Step c, weighing raw materials: per 1 liter of chemical nickel plating solution, including the following components: nickel salt: 18.3 g, nickel sulfate; reducing agent: 8.5 g, sodium hypophosphite; composite complexing agent: 12.5 g; buffer: 11.2 g, acetic acid-sodium acetate buffer system, composed of acetic acid (CH3COOH) and sodium acetate (CH3COONa); colloidal stabilizer: 5.3 g; the balance is deionized water;

[0046] Step d, adding 80% by weight of deionized water to the container, and then slowly adding the nickel salt to the deionized water while stirring at a stirring speed of 130 rpm to uniformly distribute the nickel ions in the solution;

[0047] Step e: adding a complexing agent to the container, also slowly adding and stirring, and controlling the stirring speed at 200 rpm to fully complex the complexing agent with the nickel ions;

[0048] Step f, then add the reducing agent and stir for 25 minutes at a stirring speed of 180 rpm;

[0049] Step g, then add the colloidal stabilizer and stir for 10 minutes at a stirring speed of 200 rpm;

[0050] Step h, pre-irradiating the obtained solution with ultraviolet light at an intensity of 40 mW / cm2 for 10 minutes;

[0051] Step i: adjusting the pH value to 7.1 with a buffer, and adding the balance of deionized water to obtain a chemical nickel plating solution that can improve the uniformity of the plating layer.

[0052] Example 2: A method for preparing a chemical nickel plating solution capable of improving the uniformity of a plating layer, comprising the following steps:

[0053] Step a, preparing a composite complexing agent;

[0054] Step (1), pre-irradiating TiO2 with ultraviolet light at an intensity of 35 mW / cm2 for 5 minutes;

[0055] Step (2): complexing agent A is prepared by dissolving 30 g of disodium ethylenediaminetetraacetate and 60 g of tartaric acid in 180 ml of deionized water; complexing agent B is prepared by dissolving 50 g of carboxymethyl cellulose and 30 g of magnesium ascorbyl phosphate in 1800 ml of deionized water; 50 g of complexing agent A and 20 g of complexing agent B are mixed and stirred at 36° C. to obtain a mixed solution;

[0056] Step (3), adding 1g of TiO2 to the mixed solution, and continuing to irradiate the mixed solution with ultraviolet light at an intensity of 45 mW / cm2 for 12 minutes, and drying for later use;

[0057] Step b, preparing a colloidal stabilizer: dissolving 50 g of xylitol and 100 g of potassium iodide in 120 ml of deionized water;

[0058] Step c, weighing raw materials: per 1 liter of chemical nickel plating solution, including the following components: nickel salt: 33.2 g, nickel chloride; reducing agent: 9.8 g, sodium hypophosphite; composite complexing agent: 14.3 g; buffer: 28.7 g, acetic acid-sodium acetate buffer system, composed of acetic acid (CH3COOH) and sodium acetate (CH3COONa); colloidal stabilizer: 8.8 g; the balance is deionized water;

[0059] Step d, adding 80% by weight of deionized water to the container, and then slowly adding the nickel salt to the deionized water while stirring at a stirring speed of 150 rpm to uniformly distribute the nickel ions in the solution;

[0060] Step e: adding a complexing agent to the container, also slowly adding and stirring, and controlling the stirring speed at 255 rpm to fully complex the complexing agent with the nickel ions;

[0061] Step f, then add the reducing agent and stir for 30 minutes at a stirring speed of 220 rpm;

[0062] Step g, then add the colloidal stabilizer and stir for 15 minutes at a stirring speed of 250 rpm;

[0063] Step h, pre-irradiating the obtained solution with ultraviolet light at an intensity of 45 mW / cm2 for 15 minutes;

[0064] Step i: adjusting the pH value to 6.5 with a buffer, and adding the balance of deionized water to obtain a chemical nickel plating solution that can improve the uniformity of the plating layer.

[0065] Example 3: A method for preparing a chemical nickel plating solution capable of improving the uniformity of a plating layer, comprising the following steps:

[0066] Step a, preparing a composite complexing agent;

[0067] Step (1), pre-irradiating TiO2 with ultraviolet light, with an illumination intensity of 25 mW / cm2 and an irradiation time of 4 minutes;

[0068] Step (2), complexing agent A is prepared by dissolving 20 g of disodium ethylenediaminetetraacetic acid and 50 g of tartaric acid in 100 ml of deionized water; complexing agent B is prepared by dissolving 40 g of carboxymethyl cellulose and 30 g of magnesium ascorbyl phosphate in 1500 ml of deionized water; 40 g of complexing agent A and 15 g of complexing agent B are mixed and stirred at 33° C. to obtain a mixed solution;

[0069] Step (3), adding 0.8 g of TiO2 to the mixed solution, and continuing to irradiate the mixed solution with ultraviolet light at an intensity of 42 mW / cm2 for 10 minutes, and drying for later use;

[0070] Step b, preparing a colloidal stabilizer: dissolving 40 g of xylitol and 100 g of potassium iodide in 110 ml of deionized water;

[0071] Step c, weighing raw materials: per 1 liter of chemical nickel plating solution, including the following components: nickel salt: 25.4 g, nickel acetate; reducing agent: 9.3 g, sodium hypophosphite; composite complexing agent: 12.8 g; buffer: 22.6 g, acetic acid-sodium acetate buffer system, composed of acetic acid (CH3COOH) and sodium acetate (CH3COONa); colloidal stabilizer: 7.1 g; the balance is deionized water;

[0072] Step d, adding 80% by weight of deionized water to the container, and then slowly adding the nickel salt to the deionized water while stirring at a stirring speed of 140 rpm to uniformly distribute the nickel ions in the solution;

[0073] Step e: adding a complexing agent to the container, also slowly adding and stirring, and controlling the stirring speed at 220 rpm to fully complex the complexing agent with the nickel ions;

[0074] Step f, then adding a reducing agent and stirring for 28 minutes at a stirring speed of 200 rpm;

[0075] Step g, then add the colloidal stabilizer and stir for 13 minutes at a stirring speed of 240 rpm;

[0076] Step h, pre-irradiating the obtained solution with ultraviolet light at an intensity of 44 mW / cm2 for 13 minutes;

[0077] Step i: adjusting the pH value to 7.0 with a buffer, and adding the balance of deionized water to obtain a chemical nickel plating solution that can improve the uniformity of the plating layer.

[0078] Comparative Example 1: The difference from Example 3 is that step h is missing.

[0079] Comparative Example 2: The difference from Example 3 is that step h is performed first and then step g.

[0080] Comparative Example 3: The difference from Example 3 is that the preparation of the composite complexing agent in step a is replaced by directly blending TiO2, complexing agent A and complexing agent B.

[0081] Experimental Example: The workpiece to be plated (aluminum) was placed in the chemical nickel plating solution of Examples 1-3 and Comparative Examples 1-3 at 88°C for 40 minutes to obtain plated parts. The performance of each plated part was tested. The results are shown in Table 1.

[0082] Coating uniformity test: Use a magnetic thickness gauge to measure the thickness of at least 10 randomly selected coating test points and calculate the average thickness as h 平均 , select the maximum thickness h max and minimum thickness h min , calculate e=(h max- h min )÷h 平均 When e is less than 5%, it indicates that the coating uniformity is good.

[0083] Test the adhesion between the coating and the workpiece to be plated: coating adhesion scratch tester.

[0084] Table 1 Performance test results

[0085]

[0086] The nickel plating layer of the present invention has good uniformity and a uniform and smooth appearance. The composite complexing agent is prepared by using TiO2, a complexing agent A, and a complexing agent B. TiO2 absorbs ultraviolet light energy to generate electron-hole pairs, thereby increasing the electrostatic repulsion between particles, reducing agglomeration and promoting the dispersion of TiO2. The complexing agent A and the complexing agent B are coated on the outside of TiO2, thereby promoting the stability of the components of the composite complexing agent and improving the complexing effect of the composite complexing agent. After the colloidal stabilizer is subsequently added, the colloidal stabilizer can be adsorbed on the surface of the TiO2 particles and simultaneously form a polymer protective film around the TiO2 particles, further preventing the particles from approaching each other, promoting the uniform dispersion of the nickel plating solution, thereby facilitating the uniformity of the subsequent nickel plating layer and enhancing the bonding force between the plating layer and the workpiece to be plated.

[0087] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A chemical nickel plating solution capable of improving the uniformity of a plating layer, characterized in that: Each 1 liter of chemical nickel plating solution includes the following components: Nickel salt: 18.3-33.2 g; Reducing agent: 8.5-9.8 g; Complex complexing agent: 12.5-14.3 g; Buffer: 11.2-28.7 g; Colloidal stabilizer: 5.3-8.8 g; The balance is deionized water; The pH value of the chemical nickel plating solution is 6.5-7.1; The composite complexing agent is prepared by mixing complexing agent A, complexing agent B and TiO2 in a mass ratio of 3-5:1-2:0.05-0.1; the complexing agent A is prepared by dissolving disodium ethylenediaminetetraacetic acid and tartaric acid in deionized water, and the mass ratio of disodium ethylenediaminetetraacetic acid, tartaric acid and deionized water is 1-2:2-5:6-10; the complexing agent B is prepared by dissolving carboxymethyl cellulose and magnesium ascorbyl phosphate in deionized water, and the mass ratio of carboxymethyl cellulose, magnesium ascorbyl phosphate and deionized water is 3-5:2-3:100-180; The preparation method of the composite complexing agent is: Step (1), pre-irradiating TiO2 with ultraviolet light, with an illumination intensity of 22-35 mW / cm2 and an irradiation time of 3-5 minutes; Step (2), mixing and stirring the complexing agent A and the complexing agent B to obtain a mixed solution; Step (3), adding TiO2 to the mixed solution, and continuing to irradiate the mixed solution with ultraviolet light at an intensity of 40-45 mW / cm2 for 8-12 minutes, and drying for later use; The preparation method of chemical nickel plating solution comprises the following steps: Step a, adding 80% by weight of deionized water into a container, then slowly adding nickel salt into the deionized water while stirring at a stirring speed of 130-150 rpm to uniformly distribute the nickel ions in the solution; Step b, adding a complexing agent to the container, also slowly adding and stirring, controlling the stirring speed at 200-255 rpm to fully complex the complexing agent with the nickel ions; Step c, then add the reducing agent and stir for 25-30 minutes at a stirring speed of 180-220 rpm; Step d, then add the colloidal stabilizer and stir for 10-15 minutes at a stirring speed of 200-250 rpm; Step e, pre-irradiating the obtained solution with ultraviolet light at an intensity of 40-45 mW / cm2 for 10-15 minutes; Step f: adjusting the pH value to 6.5-7.1 with a buffer, and adding the balance of deionized water to obtain a chemical nickel plating solution that can improve the uniformity of the plating layer.

2. The chemical nickel plating solution capable of improving the uniformity of the plating layer according to claim 1, wherein The nickel salt is selected from nickel sulfate, nickel chloride or nickel acetate.

3. The chemical nickel plating solution capable of improving the uniformity of the plating layer according to claim 1, wherein The reducing agent is sodium hypophosphite.

4. The chemical nickel plating solution capable of improving the uniformity of the plating layer according to claim 1, wherein In step (2), the complexing agent A and the complexing agent B are mixed and stirred at 32-36° C. to obtain a mixed solution.

5. The chemical nickel plating solution capable of improving the uniformity of the plating layer according to claim 1, wherein The colloidal stabilizer is obtained by dissolving xylitol and potassium iodide in deionized water, and the mass ratio of xylitol, potassium iodide and deionized water is 3-5:10:10-12.

6. A method for preparing a chemical nickel plating solution capable of improving the uniformity of a plating layer according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step a, adding 80% by weight of deionized water into a container, then slowly adding nickel salt into the deionized water while stirring at a stirring speed of 130-150 rpm to uniformly distribute the nickel ions in the solution; Step b, adding a complexing agent to the container, also slowly adding and stirring, controlling the stirring speed at 200-255 rpm to fully complex the complexing agent with the nickel ions; Step c, then add the reducing agent and stir for 25-30 minutes at a stirring speed of 180-220 rpm; Step d, then add the colloidal stabilizer and stir for 10-15 minutes at a stirring speed of 200-250 rpm; Step e, pre-irradiating the obtained solution with ultraviolet light at an intensity of 40-45 mW / cm2 for 10-15 minutes; Step f: adjusting the pH value to 6.5-7.1 with a buffer, and adding the balance of deionized water to obtain a chemical nickel plating solution that can improve the uniformity of the plating layer.

7. A method for using the chemical nickel plating solution capable of improving the uniformity of the plating layer according to any one of claims 1 to 5, characterized in that: The substrate to be plated is immersed in the chemical nickel plating solution, and the plating temperature is controlled to be 85-90° C., and then taken out after the plating layer reaches a certain thickness.

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