A treatment agent and treatment method for improving the surface tension of nickel on the surface of neodymium iron boron

Abstract

The present invention discloses a treatment agent and a treatment method for improving the surface tension of nickel on the surface of neodymium iron boron, belonging to the technical field of post-treatment of neodymium iron boron electroplating. The treatment agent of the present invention can treat the surface roughness of the nickel layer greater than 0.1 μm; the treatment agent includes reagent A and reagent B, and the hydroxide ion concentration in the treatment agent is 0.2 - 2.5 mol / L; the reagent A includes a strong base solution and / or ammonia water; the reagent B includes a metal organic salt, and the metal organic salt includes 0.03 - 0.2 mol / L dodecyl sulfonate and 0.04 - 0.12 mol / L citrate. The present invention can improve the binding force between the surface of the nickel layer and the dodecyl sulfonate and citrate in the metal organic salt. Under the action of the organic polar groups on the surface of the nickel layer, it is very easy to form polar bonds with polar groups such as R-OH or R-CONH2. Therefore, macroscopically, it shows an increase in surface tension.

Description

Technical Field

[0001] The present invention belongs to the technical field of post-treatment of neodymium iron boron electroplating, and more specifically, relates to a treatment agent and a treatment method for improving the surface tension of nickel on the surface of neodymium iron boron. Background Art

[0002] Currently, the demand for magnetic steels in the field of micro-motors such as VCM is increasing, and the required size of magnetic steels is getting smaller and smaller. When loading micro-magnetic steels, it is necessary to bond the neodymium iron boron magnetic steel and the loading workpiece with glue. Therefore, there are certain requirements for the surface coating tension of neodymium iron boron magnetic steels. Currently, the surface nickel plating layer tension of neodymium iron boron magnetic steels usually needs to reach more than 38 mN / m to meet the glue bonding requirements, but the traditional bright nickel process cannot meet the above requirements. In the industry, in order to meet the requirements of the surface tension of the coating, it is often necessary to develop new plating types, such as the dull nickel process, which requires additional investment of a lot of manpower and material resources.

[0003] After retrieval, Chinese invention patent CN111005044A discloses a dull nickel barrel plating process for improving the surface tension of neodymium iron boron magnets. First, the neodymium iron boron magnets are pretreated, then the pretreated neodymium iron boron is electroplated, and finally the electroplated neodymium iron boron is post-treated and cleaned and dried. During the electroplating process, a composite coating composed of a pre-plated nickel layer, an alkaline dull copper electroplating layer, a transition dull nickel layer, and a surface dull nickel layer is formed on the surface of the neodymium iron boron magnet. The main components of the pre-plated nickel layer in contact with the surface of the neodymium iron boron magnet are nickel sulfate, nickel chloride, boric acid, and brightener. The main components of the alkaline dull copper electroplating layer are copper pyrophosphate and potassium pyrophosphate. The transition dull nickel layer and the surface dull nickel layer meet the requirements of the surface tension of the neodymium iron boron magnet by adjusting and changing the brightener. The advantage of this process is that it has a high surface tension on the basis of ensuring that the coating has high corrosion resistance, but this treatment method requires the formation of a pre-plated nickel layer, an alkaline dull copper electroplating layer, a transition dull nickel layer, and a surface dull nickel layer on the surface of the neodymium iron boron magnet in sequence, which has high requirements for the coating, and the dull plating process is complex and the plating type has poor versatility.

[0004] Therefore, there is an urgent need to design a treatment agent or treatment method that can simply and effectively improve the surface tension of nickel on the surface of neodymium iron boron. Summary of the Invention

[0005] 1. Problems to be Solved

[0006] Aiming at the problem that the traditional process in the prior art cannot meet the requirements of the surface tension of nickel on the surface of neodymium iron boron magnets, the present invention provides a treatment agent and a treatment method for improving the surface tension of nickel on the surface of neodymium iron boron. By reasonably designing the components and contents of the treatment agent and under the action of appropriate treatment temperature and time, the problem that the traditional process cannot meet the requirements of the surface tension of nickel on the surface of neodymium iron boron magnets is effectively solved.

[0007] 2. Technical Solutions

[0008] To solve the above problems, the technical solutions adopted by the present invention are as follows:

[0009] A treatment agent capable of increasing the surface tension of nickel on the surface of neodymium iron boron. The treatment agent can treat the surface of a nickel layer with a roughness greater than 0.1 μm. The treatment agent includes reagent A and reagent B, and the hydroxide ion concentration in the treatment agent is 0.2 - 2.5 mol / L. Reagent A includes a strong base solution and / or ammonia water. Reagent B includes a metal organic salt, and the metal organic salt includes 0.03 - 0.2 mol / L dodecyl sulfonate and 0.04 - 0.12 mol / L citrate.

[0010] Preferably, reagent A is sodium hydroxide.

[0011] Preferably, reagent B includes sodium dodecyl sulfonate and trisodium citrate.

[0012] Preferably, it further includes an antifoaming agent, and the antifoaming agent includes a phosphate ester compound or an organosiloxane compound.

[0013] Preferably, the antifoaming agent is tributyl phosphate, and the mass ratio of tributyl phosphate to reagent B is 1:(10 - 100).

[0014] Preferably, it further includes reagent C, and reagent C is an inorganic strong base weak acid salt solution. The strong base weak acid salt includes 1 - 10 wt% sodium carbonate and 1 - 5 wt% sodium silicate.

[0015] Preferably, the ratio of reagent C to reagent B is (1 - 5):1. Reagent C at this mass ratio can enhance the binding force between the polar groups and reagent B, thereby showing an increase in surface tension.

[0016] The present invention also provides a treatment method capable of increasing the surface tension of nickel on the surface of neodymium iron boron. The treatment agent used in this treatment method is the treatment agent described in any one of the above. Immerse the neodymium iron boron magnet with a nickel layer on its surface in the treatment agent, and then take it out and dry it.

[0017] Preferably, the specific steps are as follows:

[0018] (1) Prepare the treatment agent: Dissolve each solute in water under stirring conditions, and after complete dissolution, prepare the treatment agent for standby.

[0019] (2) Prepare the substrate: Plate nickel on the surface of the neodymium iron boron magnet, and then wash the nickel layer on its surface with deionized water.

[0020] (3) Surface treatment: Immerse the washed nickel on the surface of the neodymium iron boron into the treatment agent, continuously rotate during the immersion process, and after the treatment is completed, wash with water, discharge, and dry.

[0021] Preferably, the temperature of the surface treatment is 20 - 80 °C, and the time is 10 - 180 s.

[0022] 3. Beneficial effects

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] (1) A treatment agent for improving the surface tension of nickel on the surface of neodymium iron boron of the present invention. The roughness of the surface of the nickel layer that can be treated by the treatment agent is greater than 0.1 μm. The treatment agent includes reagent A and reagent B, and the hydroxide ion concentration in the treatment agent is 0.2 - 2.5 mol / L. Reagent A includes strong alkali solution and / or ammonia water. Reagent B includes metal organic salts, and the metal organic salts include 0.03 - 0.2 mol / L dodecyl sulfonate and 0.04 - 0.12 mol / L citrate. Through the above settings, when the roughness of the nickel layer surface is greater than 0.1 μm, the surface tension matches the treatment agent, and the alkaline environment of the treatment agent can provide abundant hydroxide ions, thereby enhancing the binding force between the nickel layer surface and dodecyl sulfonate and citrate in the metal organic salts. Under the action of the organic polar groups on the nickel layer surface, it is very easy to form polar bonds with polar groups such as R - OH or R - CONH2. Therefore, macroscopically, it shows an increase in surface tension.

[0025] (2) A treatment method for improving the surface tension of nickel on the surface of neodymium iron boron of the present invention. The treatment agent used in this treatment method is the treatment agent in the present invention, and its specific steps are as follows: (a) Prepare the treatment agent: Dissolve each solute in water under stirring conditions, and after complete dissolution, prepare the treatment agent for standby; (b) Prepare the substrate: Plate nickel on the surface of the neodymium iron boron magnet, and then wash and dry the nickel layer on its surface with deionized water for standby; (c) Surface treatment: Immerse the washed nickel on the surface of the neodymium iron boron into the treatment agent, continuously rotate during the immersion process, and after the treatment is completed, wash with water, discharge, and dry. The temperature of the surface treatment is 20 - 80 °C, and the time is 10 - 180 s. The treatment agent of the present invention is used to treat the nickel layer surface of the neodymium iron boron magnet, and it can be completed only by short - time immersion, which simplifies the treatment process for improving the surface tension of the nickel layer surface of the neodymium iron boron magnet. Description of the drawings

[0026] Figure 1 It is a test physical drawing of the nickel on the surface of the neodymium iron boron magnet after being treated with the treatment agent of the present invention;

[0027] Figure 2 It is a test physical drawing of the nickel on the surface of the neodymium iron boron magnet without being treated with the treatment agent of the present invention. Detailed implementation manners

[0028] The present invention will be further described below in conjunction with specific embodiments.

[0029] The structures, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the conditions for the implementation of the present invention. Therefore, they do not have substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size, without affecting the efficacy that the present invention can produce and the purpose that can be achieved, should still fall within the scope covered by the technical content disclosed in the present invention. At the same time, terms such as "upper", "lower", "left", "right", "middle", etc. cited in this specification are only for the convenience of clear narration and are not used to limit the scope of implementation. The change or adjustment of their relative relationship, without substantial change in the technical content, should also be regarded as the scope where the present invention can be implemented; in addition, the various embodiments of the present invention are not independent of each other but can be combined.

[0030] Example 1

[0031] A treatment agent for improving the surface tension of nickel on the surface of neodymium iron boron in this example is prepared as follows: Add 6 L of pure water to a 15 L tank, and successively add under stirring conditions: 500 g of sodium hydroxide, 200 g of sodium carbonate, 150 g of trisodium citrate, 100 g of sodium silicate, 100 g of sodium dodecyl sulfonate hydrate, and 3 mL of tributyl phosphate, and make up the volume to 10 L with pure water to prepare the treatment agent.

[0032] This example also provides a treatment method for improving the surface tension of nickel on the surface of neodymium iron boron. The specific steps are as follows:

[0033] (1) Heat the prepared treatment agent to 70 °C and set aside;

[0034] (2) After washing the neodymium iron boron magnet just plated with bright nickel with water, put it into the tank containing the treatment agent and soak for 90 s, and the roller rotates continuously during the soaking process;

[0035] (3) After the product treated in step (2) is washed with pure water twice, discharge, blow dry, and bake at 80 °C for 30 min;

[0036] Finally, after the product baked in step (3) is naturally cooled, it is tested with a 42# dyn pen, and the result is as Figure 1 shown. It can be seen from the figure that the glue is evenly coated on the nickel layer on the surface of the neodymium iron boron and does not shrink. This shows that the surface tension of the nickel layer after being treated with the treatment agent of the present invention has been effectively improved, the surface tension value is greater than or equal to 42 mN / m, the polar bond between the nickel layer and the glue is firmly combined, and therefore the glue spreads flat.

[0037] Comparative Example 1

[0038] This comparative example provides an implementation for comparison: After the neodymium iron boron magnet just plated with bright nickel is washed with water, it is directly tested and compared with the conventional bright nickel without using the treatment agent on the surface with a #42 dyn pen. The results are as Figure 2 shown. It can be seen from the figure that the glue shrinks on the surface of the nickel layer.

[0039] Comparing with Example 1, it can be seen that without being treated with the treatment agent of the present invention, the surface tension of the nickel layer is too low to bond with the polar bonds in the glue. Therefore, the treatment agent of the present invention can significantly improve the surface tension of the nickel on the surface layer of the neodymium iron boron magnet, and the treatment method is simple and economical.

[0040] The present invention has been described in detail above in connection with specific exemplary embodiments. However, it should be understood that various modifications and variations can be made without departing from the scope of the present invention as defined by the appended claims. The detailed description and the drawings should be considered illustrative only and not restrictive. If there are any such modifications and variations, they will all fall within the scope of the present invention described herein. In addition, the background art is intended to illustrate the research and development status and significance of the present technology, and is not intended to limit the present invention or the application fields of the present application and the present invention.

[0041] More specifically, although the exemplary embodiments of the present invention have been described herein, the present invention is not limited to these embodiments, but includes any and all embodiments that those skilled in the art can recognize from the foregoing detailed description through modifications, omissions, for example, combinations between various embodiments, adaptive changes, and / or substitutions. The limitations in the claims can be broadly interpreted according to the language used in the claims and are not limited to the examples described in the foregoing detailed description or during the implementation of this application. These examples should be considered non-exclusive. Any steps recited in any method or process claim can be executed in any order and are not limited to the order set forth in the claims. Therefore, the scope of the present invention should be determined only by the appended claims and their legal equivalents, rather than by the description and examples given above.

Claims

1. A treatment agent capable of increasing the surface tension of nickel on the surface of neodymium iron boron, characterized in that, The treatment agent can treat the surface of a nickel layer with a roughness greater than 0.1 μm; the treatment agent includes reagent A and reagent B, and the hydroxide ion concentration in the treatment agent is 0.2 - 2.5 mol / L; Reagent A includes a strong alkali solution and / or ammonia water; Reagent B includes a metal organic salt, and the metal organic salt includes 0.03 - 0.2 mol / L dodecyl sulfonate and 0.04 - 0.12 mol / L citrate; The treatment agent further includes an antifoaming agent, the antifoaming agent is tributyl phosphate, and the mass ratio of tributyl phosphate to reagent B is 1:(10 - 100); The treatment agent further includes reagent C, and reagent C is an inorganic strong base weak acid salt solution; the strong base weak acid salt includes 1 - 10 wt% sodium carbonate and 1 - 5 wt% sodium silicate.

2. The treating agent for improving the surface tension of nickel on the surface of neodymium iron boron according to claim 1, wherein, Reagent A is sodium hydroxide.

3. A treatment agent capable of increasing the surface tension of nickel on the surface of neodymium iron boron according to claim 1, characterized in that, Reagent B includes sodium dodecyl sulfate and trisodium citrate.

4. A treatment agent for improving the surface tension of nickel on the surface of neodymium iron boron according to claim 1, characterized in that, The ratio of reagent C to reagent B is (1 - 5):

1.

5. A treatment method for improving the surface tension of nickel on the surface of neodymium iron boron, wherein the treatment agent used in the treatment method is the treatment agent described in any one of claims 1 to 4, characterized in that, Immerse the neodymium iron boron magnet with a nickel layer on its surface in the treatment agent, take it out after washing with water and dry it.

6. A treatment method for improving the surface tension of nickel on the surface of neodymium iron boron according to claim 5, characterized in that, The specific steps are as follows: (1) Prepare the treatment agent: Dissolve each solute in water under stirring conditions, and prepare the treatment agent after complete dissolution for standby; (2) Prepare the substrate: Plate nickel on the surface of the neodymium iron boron magnet, and then wash the nickel layer on its surface with deionized water; (3) Surface treatment: Immerse the washed nickel on the surface of the neodymium iron boron into the treatment agent, continuously rotate during the immersion process, and after the treatment is completed, wash with water, discharge, and dry.

7. A treatment method for improving the surface tension of nickel on the surface of neodymium iron boron according to claim 6, characterized in that, The temperature of the surface treatment is 20 - 80 °C, and the time is 10 - 180 s.

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