Nickel plating protective agent and preparation method of nickel plating copper flat wire based on nickel plating protective agent

Abstract

The embodiment of the invention provides a nickel plating protective agent and a preparation method of a nickel plating copper flat wire based on the nickel plating protective agent, the nickel plating protective agent comprises a water-soluble nickel plating protective agent which is a solution formed by mixing methylisothiazolinone, glycerol, styrene-acrylic emulsion, polyether, hydrochloric acid and water, the mass fraction of methylisothiazolinone in the solution is 0.5-1.2 wt.%, the mass fraction of glycerol in the solution is 0.5-1.2 wt.%, and the mass fraction of polyether in the solution is 0.5-1.2 wt.%. The pH value of the solution is 3-7; the surface of the prepared nickel-plated copper flat wire has better wettability to water, the dyne value of the surface can reach 34, the nickel-plated copper flat wire is superior to that of a conventional nickel-plated copper flat wire treated by an oily protective agent, and the surface of the prepared nickel-plated copper flat wire also has good corrosion resistance while the good wettability to water is achieved, so that the surface of the nickel-plated copper flat wire has good corrosion resistance. The neutral salt spray performance can reach more than level 8 in 96 hours, and in addition, the components of the water-soluble nickel plating protective agent and the nickel plating solution used in the method are simple, cheap and free of toxic and harmful risks.

Description

Technical Field

[0001] The invention relates to the technical field of metal surface treatment, and in particular to a nickel plating protective agent and a method for preparing a nickel-plated copper flat wire based on the nickel plating protective agent. Background Art

[0002] Electroplating nickel occupies an important position in modern industry due to its excellent performance and wide application fields. However, nickel metal easily forms oxides and sulfides in the atmosphere, which in turn causes the surface to turn yellow and discolor, not only losing the metallic luster of nickel, but also increasing the contact resistance of the surface, reducing the bonding force between nickel and other surface coatings, causing the surface coating to peel off, and nickel oxides and sulfides also reduce its welding performance.

[0003] The protective treatment of the nickel layer is to prevent the nickel layer from reacting with oxygen or other corrosive gases, affecting the appearance and performance of the plated parts. At the same time, the ideal nickel protective agent also needs to meet the requirements of not affecting the appearance of the nickel layer, conductivity, product life (neutral salt spray performance) and preparation cost. The nickel protective agent on the current market is basically an oil-soluble product, which is essentially a layer of paint on the nickel. Although its neutral salt spray performance meets the requirements, the conductivity and welding performance cannot be achieved, and the price is relatively high. In addition, hexavalent chromium passivation protection can also be used, but not only is its effect mediocre, but hexavalent chromium pollutes the environment, does not comply with the EU ROHS directive, and has been expressly banned. Summary of the invention

[0004] The invention provides a nickel plating protective agent and a method for preparing a nickel-plated copper flat wire based on the nickel plating protective agent, which improve the water wettability of the surface of the nickel-plated copper flat wire after surface protection treatment while achieving good corrosion resistance.

[0005] To achieve the above object, the technical solution of the embodiment of the present invention is implemented as follows:

[0006] In the first aspect, an embodiment of the present invention provides a water-soluble nickel plating protective agent, characterized in that the water-soluble nickel plating protective agent is a solution formed by mixing methylisothiazolinone, glycerin, styrene acrylic emulsion, polyether, hydrochloric acid and water, wherein the mass fraction of methylisothiazolinone in the solution is 0.5-1.2wt.%, and the pH value of the solution is 3-7.

[0007] In a second aspect, an embodiment of the present invention provides a method for preparing a nickel-plated copper flat wire based on a nickel-plating protective agent, the method comprising:

[0008] (1) Polish and draw the copper flat wire to make its surface uniform;

[0009] (2) Using 20-40g / L sodium hydroxide, 30-50g / L sodium carbonate, and 20-40g / L trisodium phosphate as degreasing solutions, the copper flat wire is degreased and degreased at a temperature of 50-60°C, a time of 0.5-1min, and a current density of 5A / dm 2 , then wash with hot water;

[0010] (2) Using dilute sulfuric acid as an activation solution, the degreased copper flat wire is activated for 0.5-1 min at room temperature and then washed with water;

[0011] (3) electroplating a dark nickel layer and a semi-bright nickel layer on the surface of the copper flat wire in sequence using a direct current power supply, wherein the plating solution used for the dark nickel layer is composed of 250-500 g / L nickel sulfamate, 5-10 g / L nickel chloride, 30-50 g / L boric acid, and deionized water, the plating solution temperature is 45-60° C., and the pH value is 3-4, and then washing with water to obtain the dark nickel-plated copper flat wire; electroplating the semi-bright nickel layer, the plating solution is composed of 250-500 g / L nickel sulfamate, 5-10 g / L nickel chloride, 30-50 g / L boric acid, 10-30 ml / L brightener, and deionized water, the plating solution temperature is 45-60° C., and the pH value is 3-4, and then washing with water to obtain the nickel-plated copper flat wire;

[0012] (4) Blowing compressed nitrogen at a fixed angle through an air nozzle to the surface of the nickel-plated copper flat wire to completely remove moisture from the surface of the nickel-plated copper flat wire, wherein the flow rate of the nitrogen through the air nozzle is 40-90 m / s, the angle between the nitrogen spraying direction and the surface of the nickel-plated copper flat wire is 140°, and the processing time of the nickel-plated copper flat wire is 5 s / dm 2 ;

[0013] (5) placing the nickel-plated copper flat wire after dehydration in a nickel-plating protective agent for post-protection treatment at a temperature of 45-60° C. for 1 min, wherein the nickel-plating protective agent comprises methylisothiazolinone, glycerin, styrene acrylic emulsion, polyether, hydrochloric acid, and water;

[0014] (6) The nickel-plated copper flat wire obtained after the treatment in (5) is washed and dried to obtain a corrosion-resistant nickel-plated copper flat wire having a hydrophilic protective layer on the surface.

[0015] The thickness of the dark nickel layer is 3-10 μm, the thickness of the semi-bright nickel layer is 1-5 μm, and the current density during electroplating is 5-8 A / dm 2 ;

[0016] The glycerol in the water-soluble nickel plating protective agent acts as a brightener, and its mass proportion in the solution is 0.2-0.6wt.%.

[0017] The styrene acrylic emulsion in the water-soluble nickel plating protective agent acts as a film-forming agent, has a solid content of 30%, and accounts for 0.1-0.5wt.% of the mass in the solution of the water-soluble nickel plating protective agent.

[0018] The polyether in the water-soluble nickel plating protective agent acts as a dispersant, and its mass proportion in the solution is 0.1-0.5wt.%.

[0019] The hydrochloric acid solution in the water-soluble nickel plating protective agent acts as a pH regulator, wherein the mass fraction of hydrochloric acid is 37%, and the mass proportion of the hydrochloric acid solution in the water-soluble nickel plating protective agent solution is 0.1-0.5wt.%.

[0020] The embodiment of the present invention provides a method for preparing a nickel-plated copper flat wire based on a nickel-plating protective agent, wherein the method comprises a water-soluble nickel-plating protective agent, which is a solution formed by mixing methylisothiazolinone, glycerol, styrene-acrylic emulsion, polyether, hydrochloric acid and water, wherein the mass fraction of methylisothiazolinone in the solution is 0.5-1.2wt.%, and the pH value of the solution is 3-7; the surface of the nickel-plated copper flat wire prepared in this way has better water wettability, and the surface dyne value can reach 34, which is better than conventional oily protective agents and chromium-treated nickel-plated copper flat wires, and while achieving good water wettability, the surface of the nickel-plated copper flat wire prepared in the present invention also has good corrosion resistance, and the neutral salt spray performance can reach 96h 8 level or above, and in addition, the components of the water-soluble nickel-plating protective agent and the nickel-plating solution used in the present invention are simple, inexpensive and free of toxic risks.

[0021] Compared with the prior art, the method for preparing a nickel-plated copper flat wire based on a nickel-plating protective agent provided by the present invention has the following beneficial effects:

[0022] Compared with conventional oily protective agents, the water-soluble nickel-plating protective agent in the present invention innovatively uses methylisothiazolinone as the main component, and has good hydrophilic and corrosion-resistant effects at the same time. Further, under the synergistic effect of the film-forming agent and the dispersant (styrene acrylic emulsion and polyether), the water-soluble nickel-plating protective agent can form a uniform and dense high-quality protective layer on the surface of the nickel-plated copper flat wire, which not only has better water wettability, the dyne value can reach 34, but also has better corrosion resistance, and can reach 96h 8 level or above in the neutral salt spray test. In addition, the components of the water-soluble nickel-plating protective agent and the nickel-plating solution used in the preparation method provided by the present invention are simple, cheap, and have no toxic risk. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of the preparation process of nickel-plated copper flat wire based on a nickel-plating protective agent provided in an embodiment of the present invention;

[0024] Figure 2 1 is a graph showing the dyne value test results of the embodiment of the present invention and the comparative example 4;

[0025] Figure 3 The neutral salt spray test results of the embodiment of the present invention and the comparative example 4 are shown in FIG. DETAILED DESCRIPTION

[0026] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0028] Before further describing the present invention in detail, the nouns and terms involved in the embodiments of the present invention are explained. The nouns and terms involved in the embodiments of the present invention are subject to the following explanations.

[0029] Embodiment 1

[0030] This embodiment takes the preparation of a corrosion-resistant nickel-plated copper flat wire with a total nickel-plating thickness greater than 2 μm based on a water-soluble nickel-plating protective agent as an example, and the specific preparation steps are as follows:

[0031] (1) Polish and draw the copper flat wire to make its surface uniform;

[0032] (2) Using 40 g / L sodium hydroxide, 50 g / L sodium carbonate, and 40 g / L trisodium phosphate as degreasing solutions, the copper flat wire was degreased and degreased at a temperature of 60 °C, a time of 0.5 min, and a current density of 5 A / dm 2 , then wash with hot water;

[0033] (2) Using 250 g / L dilute sulfuric acid as an activation solution, the degreased copper flat wire was activated at room temperature for 0.5 min and then washed with water;

[0034] (3) A dark nickel layer and a semi-bright nickel layer are electroplated on the surface of the copper flat wire in sequence using a direct current power supply, wherein the thickness of the electroplated dark nickel layer is 4 μm and the current density during electroplating is 7.5 A / dm 2 The plating solution used was 350 g / L nickel sulfamate, 8 g / L nickel chloride, 40 g / L boric acid, and deionized water. The plating solution temperature was 55°C and the pH value was 3.5. The dark nickel-plated copper flat wire was then washed with water. The thickness of the semi-bright nickel layer was 1 μm, and the current density during electroplating was 7.5 A / dm 2The plating solution used is composed of 350g / L nickel sulfamate, 8g / L nickel chloride, 40g / L boric acid, 20ml / L brightener, and deionized water. The plating solution temperature is 55°C and the pH value is 3.5. Then, the nickel-plated copper flat wire is obtained by washing.

[0035] (4) Blowing compressed nitrogen at a fixed angle through an air nozzle to the surface of the nickel-plated copper flat wire to completely remove moisture from the surface of the nickel-plated copper flat wire, wherein the flow rate of the nitrogen through the air nozzle is 40-90 m / s, the angle between the nitrogen spraying direction and the surface of the nickel-plated copper flat wire is 140°, and the processing time of the nickel-plated copper flat wire is 5 s / dm 2 ;

[0036] (5) The nickel-plated copper flat wire after dehydration is placed in a water-soluble nickel-plating protective agent for surface treatment at a temperature of 50° C. for 1 min. The components of the water-soluble nickel-plating protective agent are 0.75 wt.%, 0.35 wt.%, 0.25 wt.%, 30% styrene acrylic emulsion, 0.15 wt.%, polyether, 0.15 wt.%, hydrochloric acid (37%), and water. The pH value of the solution is 5.

[0037] (6) The nickel-plated copper flat wire obtained after the treatment in (5) is washed and dried to obtain a corrosion-resistant nickel-plated copper flat wire having a hydrophilic protective layer on the surface.

[0038] Comparative Example 1

[0039] Compared with the embodiment, in this comparative example, only the mass fraction of methylisothiazolinone in the water-soluble nickel plating protective agent in step (5) is adjusted from 0.75wt.% to 0.4wt.%, and the other steps and solutions are consistent with the embodiment.

[0040] Comparative Example 2

[0041] Compared with the embodiment, in this comparative example, only the mass fraction of the styrene acrylic emulsion in the water-soluble nickel plating protective agent in step (5) is adjusted from 0.35wt.% to 0.05wt.%, and the other steps and solutions are consistent with the embodiment.

[0042] Comparative Example 3

[0043] Compared with the embodiment, in this comparative example, only the mass fraction of the polyether in the water-soluble nickel plating protective agent in step (5) is adjusted from 0.15wt.% to 0.05wt.%, and the other steps and solutions are consistent with the embodiment.

[0044] Comparative Example 4

[0045] Compared with the embodiment, the comparative example does not perform step (5), that is, the nickel-plated copper flat wire is not subjected to surface treatment with a water-soluble nickel plating protective agent after nickel plating. Instead, the surface of the nickel-plated copper flat wire is treated with a conventional oily protective agent. The other steps and solutions are consistent with the embodiment.

[0046] Comparative Example 5

[0047] Compared with the embodiment, the comparative example does not perform step (4), that is, the surface of the nickel-plated copper flat wire is not thoroughly dehydrated after the nickel plating is completed. The other steps and solutions are consistent with the embodiment.

[0048] Comparative Example 6

[0049] Compared with the embodiment, this comparative example only changes the nitrogen purge in step (4) to using a hair dryer to remove moisture from the surface of the nickel-plated copper flat wire, and the other steps and solutions are consistent with the embodiment.

[0050] Please refer to Table 1 and Table 2, which are the comparison summaries of all embodiments and comparative examples in the present invention, from which it can be seen that:

[0051] 1) By comparing Example 1 with Comparative Examples 1, 2, 3 and 4, it can be concluded that in Example 1, when the mass proportion of methylisothiazolinone in the water-soluble nickel plating protective agent is 0.75wt.%, the mass proportion of styrene acrylic emulsion (30%) is 0.25wt.%, and the mass proportion of polyether is 0.15wt.%, the water-soluble nickel plating protective agent can form a uniform and dense high-quality protective layer on the surface of the nickel-plated copper flat wire, which not only has good wettability to water, the dyne value can reach 34, but also has good corrosion resistance, and can reach 96h 8 level or above in the neutral salt spray test.

[0052] 2) The content of methylisothiazolinone in Comparative Example 1 is reduced, and the water wettability and corrosion resistance of the protective layer are reduced. However, the contents of styrene acrylic emulsion and polyether as film-forming agent and dispersant respectively remain unchanged, which ensures the compactness of the protective layer. Therefore, the dyne value and corrosion resistance of the nickel-plated copper flat wire surface in Comparative Example 1 are better than those in Comparative Example 2 and Comparative Example 3; Comparative Example 4 uses a conventional oily protective agent. Although the neutral salt spray test result can reach 96h 8 level, the ink formed on its surface using a No. 34 dyne pen shrinks rapidly (see attached Figure 3 ), indicating that its surface value is far from 34, and further testing shows that its surface dyne value is 28;

[0053] 3) By comparing Example 1 with Comparative Examples 1, 2, 3 and 4, it can be concluded that before using a water-soluble nickel-plating protective agent to form a protective layer on the surface of the nickel-plated copper flat wire, it is very important to thoroughly remove water from the surface of the nickel-plated copper flat wire. The high-flow rate of nitrogen in Example 1 not only effectively removes moisture from the surface of the nickel-plated copper flat wire and inside the pores that may exist on the surface, but also nitrogen avoids possible oxidation of nickel during the treatment process, thereby improving the subsequent surface treatment effect of the water-soluble nickel-plating protective agent on the nickel-plated copper flat wire; while the treatment methods in Comparative Examples 5 and 6 cannot completely remove moisture from the surface of the nickel-plated copper flat wire, affecting the treatment effect of the water-soluble nickel-plating protective agent on the surface of the nickel-plated copper flat wire, thereby affecting the surface performance of the final nickel-plated copper flat wire.

[0054]

[0055] Table 1

[0056]

[0057] Table 2

[0058] In summary, compared with the prior art, the example of the present invention provides a method for preparing a nickel-plated copper flat wire based on a nickel-plating protective agent. The surface of the prepared corrosion-resistant nickel-plated copper flat wire based on a water-soluble nickel-plating protective agent has better water wettability, and the surface dyne value can reach 34, which is better than conventional oily protective agents and chromium-treated nickel-plated copper flat wires. While achieving good water wettability, the surface of the nickel-plated copper flat wire prepared in the present invention also has good corrosion resistance, and the neutral salt spray performance can reach 96 h 8 level or above. In addition, the components of the water-soluble nickel-plating protective agent and the nickel plating solution used in the present invention are simple, inexpensive, and have no toxic risk.

[0059] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0060] In this document, the terms "comprises," "comprising," or any other variations thereof, are intended to cover a non-exclusive inclusion of elements other than those listed and may also include additional elements not expressly listed.

[0061] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A nickel plating protective agent, characterized in that, include: The invention discloses a solution prepared by mixing methylisothiazolinone, glycerol, styrene-acrylic emulsion, polyether, hydrochloric acid and water, wherein the mass fraction of methylisothiazolinone in the solution is 0.5-1.2wt.%, and the pH value of the solution is 3-7.

2. A method for preparing a nickel-plated copper flat wire with a nickel-plated protective agent, characterized in that: The preparation method comprises: (1) Polish and draw the copper flat wire to make its surface uniform; (2) Using 20-40g / L sodium hydroxide, 30-50g / L sodium carbonate, and 20-40g / L trisodium phosphate as degreasing solutions, the copper flat wire is degreased and degreased at a temperature of 50-60°C, a time of 0.5-1min, and a current density of 5A / dm 2 , then wash with hot water; (2) Using dilute sulfuric acid as an activation solution, the degreased copper flat wire is activated for 0.5-1 min at room temperature and then washed with water; (3) electroplating a dark nickel layer and a semi-bright nickel layer on the surface of the copper flat wire in sequence using a direct current power supply, wherein the plating solution used for the dark nickel layer is composed of 250-500 g / L nickel sulfamate, 5-10 g / L nickel chloride, 30-50 g / L boric acid, and deionized water, the plating solution temperature is 45-60° C., and the pH value is 3-4, and then washing with water to obtain the dark nickel-plated copper flat wire; electroplating the semi-bright nickel layer, the plating solution is composed of 250-500 g / L nickel sulfamate, 5-10 g / L nickel chloride, 30-50 g / L boric acid, 10-30 ml / L brightener, and deionized water, the plating solution temperature is 45-60° C., and the pH value is 3-4, and then washing with water to obtain the nickel-plated copper flat wire; (4) blowing compressed nitrogen at a fixed angle on the surface of the nickel-plated copper flat wire through an air nozzle to completely remove moisture on the surface of the nickel-plated copper flat wire, wherein the flow rate of the nitrogen through the air nozzle is 40-90 m / s, the angle between the nitrogen spraying direction and the surface of the nickel-plated copper flat wire is 120-140°, and the processing time of the nickel-plated copper flat wire during the process is 5 s / dm 2 ; (5) placing the nickel-plated copper flat wire after dehydration in a nickel-plating protective agent for post-protection treatment at a temperature of 45-60° C. for 1 min, wherein the nickel-plating protective agent comprises methylisothiazolinone, glycerin, styrene acrylic emulsion, polyether, hydrochloric acid, and water; (6) The nickel-plated copper flat wire obtained after the treatment in (5) is washed and dried to obtain a corrosion-resistant nickel-plated copper flat wire having a hydrophilic protective layer on the surface.

3. The method for preparing a nickel-plated copper flat wire based on a nickel-plating protective agent according to claim 2, characterized in that: The thickness of the dark nickel layer is 3-10 μm, the thickness of the semi-bright nickel layer is 1-5 μm, and the current density during electroplating is 5-8 A / dm 2 .

4. The method for preparing a nickel-plated copper flat wire based on a nickel-plating protective agent according to claim 2, characterized in that: The glycerol in the nickel plating protective agent acts as a brightener, and its mass proportion in the solution is 0.2-0.6wt.%.

5. The method for preparing a nickel-plated copper flat wire based on a nickel-plating protective agent according to claim 2, characterized in that: The styrene acrylic emulsion in the nickel plating protective agent acts as a film-forming agent, has a solid content of 30%, and accounts for 0.1-0.5wt.% of the mass in the solution of the nickel plating protective agent.

6. The method for preparing a nickel-plated copper flat wire based on a nickel-plating protective agent according to claim 2, characterized in that: The polyether in the nickel plating protective agent acts as a dispersant, and accounts for 0.1-0.5wt.% by mass in the solution.

7. The method for preparing a nickel-plated copper flat wire based on a nickel-plating protective agent according to claim 2, characterized in that: The hydrochloric acid in the nickel plating protective agent acts as a pH regulator, wherein the mass fraction of the hydrochloric acid is 37%, and the mass proportion of the hydrochloric acid in the nickel plating protective agent solution is 0.1-0.5wt.%.

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