阅读说明：本技术 一种化学镀镍镀液及其制备方法 (Chemical nickel plating solution and preparation method thereof ) 是由 丁先峰 钟文波 于 2020-08-10 设计创作，主要内容包括：本发明属于化学镀镍技术领域,具体涉及一种化学镀镍镀液及其制备方法。本发明提供的化学镀镍镀液由以下成分及其重量份数组成：镍盐38份、连二硫酸钠20份、络合剂19份、缓冲剂4份、润湿剂13份、稳定剂4份、光亮剂9份、十二烷基二羟基乙基甜菜碱3份、N-酰基谷氨酸8份、去离子水60份。本发明提供的化学镀镍镀液中的络合剂与镍离子形成的络合物比较稳定,能够保证镍离子均匀地沉积在镀件表面,形成均匀且完整的镀层,镀层具有较好的光亮度。此外,本发明提供的化学镀镍镀液具有良好的热稳定性,高温状态下不产生镀液分解。(The invention belongs to the technical field of chemical nickel plating, and particularly relates to a chemical nickel plating solution and a preparation method thereof. The chemical nickel plating solution provided by the invention comprises the following components in parts by weight: 38 parts of nickel salt, 20 parts of sodium dithionate, 19 parts of complexing agent, 4 parts of buffering agent, 13 parts of wetting agent, 4 parts of stabilizing agent, 9 parts of brightening agent, 3 parts of dodecyl dihydroxy ethyl betaine, 8 parts of N-acyl glutamic acid and 60 parts of deionized water. The complexing agent in the chemical nickel plating solution provided by the invention is relatively stable with the complex formed by nickel ions, and can ensure that the nickel ions are uniformly deposited on the surface of a plated part to form a uniform and complete plating layer, and the plating layer has better brightness. In addition, the chemical nickel plating solution provided by the invention has good thermal stability, and the solution is not decomposed at high temperature.)

1. The chemical nickel plating solution is characterized by comprising the following components in parts by weight:

25-40 parts of nickel salt, 10-24 parts of sodium dithionate, 15-30 parts of complexing agent, 1-8 parts of buffering agent, 5-15 parts of wetting agent, 1-4 parts of stabilizer, 6-12 parts of brightener, 1-5 parts of dodecyl dihydroxy ethyl betaine, 6-10 parts of N-acyl glutamic acid and 50-80 parts of deionized water.

2. An electroless nickel plating solution according to claim 1, comprising the following components in parts by weight: 38 parts of nickel salt, 20 parts of sodium dithionate, 19 parts of complexing agent, 4 parts of buffering agent, 13 parts of wetting agent, 4 parts of stabilizing agent, 9 parts of brightening agent, 3 parts of dodecyl dihydroxy ethyl betaine, 8 parts of N-acyl glutamic acid and 60 parts of deionized water.

3. An electroless nickel plating solution according to claim 1 or 2, wherein the nickel salt is composed of nickel sulfate, nickel acetate and nickel chloride in a mass ratio of 15-20:4-5: 11-16.

4. The electroless nickel plating solution according to claim 1 or 2, wherein the complexing agent is composed of tartaric acid and sodium alginate in a mass ratio of 13-20: 5-9.

5. An electroless nickel plating solution according to claim 1 or 2, wherein said buffer is sodium acetate.

6. The electroless nickel plating solution according to claim 1 or 2, wherein the wetting agent comprises dihexyl sodium sulfosuccinate, dithiothreitol and mercaptobutyric acid at a mass ratio of 21-23:2-5: 13-17.

7. An electroless nickel plating solution according to claim 1 or 2, wherein said stabilizer is 1, 4-phenylene bis (thiourea).

8. An electroless nickel plating solution according to claim 1 or 2, wherein said brightener consists of sodium benzenetrisulfonate and benzenesulphonic acid in a mass ratio of 4: 7.

9. A method of preparing an electroless nickel plating solution according to any of claims 1 to 8, comprising the steps of:

s1, adding the wetting agent, the stabilizer, the dodecyl dihydroxy ethyl betaine and the N-acyl glutamic acid in the formula ratio into deionized water at room temperature, and stirring at the rotating speed of 500rpm for 20min to prepare a mixed solution A;

s2, adding nickel salt, complexing agent and buffering agent into the mixed solution A prepared in the step S1, and continuing stirring for 30min to prepare mixed solution B;

s3, adding sodium dithionate and brightener into the mixed solution B prepared in the step S2, continuing stirring for 15min, and adding a sodium carbonate solution with the mass percent of 5% to adjust the pH value to 5.0-6.0, thus obtaining the sodium dithionate-brightener.

Technical Field

The invention belongs to the technical field of chemical nickel plating, and particularly relates to a chemical nickel plating solution and a preparation method thereof.

Background

Electroless nickel plating, also known as electroless nickel plating or autocatalytic nickel plating, is a nickel deposition process in which nickel ions are reduced on a metal surface by autocatalytic reduction with a suitable reducing agent in solution. In the circuit board, the nickel layer is formed between the copper circuit layer and the gold layer of the circuit board, so that the defects of poor weldability and short service life of the circuit board caused by mutual diffusion between copper and gold can be avoided, and meanwhile, the formed nickel layer also improves the mechanical strength of the metal layer.

The chemical nickel plating has simple process, no need of external power supply and good uniformity; depositing on various non-metal substrates such as high polymer materials, inorganic non-metal materials and the like; the characteristics of corrosion resistance, wear resistance, strong plating binding force and the like are rapidly developed and widely applied. The plating solution composition of chemical nickel plating is very important, and the common chemical nickel plating solution comprises metal salt, a reducing agent, a complexing agent, a buffering agent, a stabilizing agent, a pH regulator and the like.

Compared with electroplating nickel, the chemical nickel plating layer has the remarkable advantages of uniformity, hardness, wear resistance, corrosion resistance and the like, and has wide application. However, the plating layer of the existing chemical nickel plating solution in the market generally has the technical problems of rough plating layer, slow deposition speed, incomplete plating layer, poor stability of the plating solution and the like. Patent publication No. CN109112509A discloses a high corrosion-resistant chemical nickel plating solution and a preparation method thereof, wherein the disclosed chemical nickel plating solution is mainly prepared by mixing various components such as nickel sulfate, sodium hypophosphite, citric acid, lactic acid, propionic acid, sodium acetate, a wetting agent, a brightening agent, a stabilizing agent and the like. The chemical nickel plating solution has certain corrosion resistance, but the plating layer of the chemical nickel plating solution has uneven thickness, rough surface and poor stability.

In conclusion, the technical problems of rough plating layer, slow deposition speed, incomplete plating layer, poor plating solution stability and the like generally exist in the prior art.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide an electroless nickel plating solution and a preparation method thereof. The chemical nickel plating solution provided by the invention has the advantages that the formed plating layer is flat and complete, the deposition speed is high, the plating solution can stably exist, and the plating solution is not decomposed at a high temperature.

In order to achieve the purpose, the technical scheme of the invention is as follows:

the chemical nickel plating solution comprises the following components in parts by weight:

25-40 parts of nickel salt, 10-24 parts of sodium dithionate, 15-30 parts of complexing agent, 1-8 parts of buffering agent, 5-15 parts of wetting agent, 1-4 parts of stabilizer, 6-12 parts of brightener, 1-5 parts of dodecyl dihydroxy ethyl betaine, 6-10 parts of N-acyl glutamic acid and 50-80 parts of deionized water.

Further, the chemical nickel plating solution comprises the following components in parts by weight: 38 parts of nickel salt, 20 parts of sodium dithionate, 19 parts of complexing agent, 4 parts of buffering agent, 13 parts of wetting agent, 4 parts of stabilizing agent, 9 parts of brightening agent, 3 parts of dodecyl dihydroxy ethyl betaine, 8 parts of N-acyl glutamic acid and 60 parts of deionized water.

Further, the nickel salt in the chemical nickel plating solution consists of nickel sulfate, nickel acetate and nickel chloride according to the mass ratio of 15-20:4-5: 11-16.

Furthermore, the complexing agent in the chemical nickel plating solution consists of tartaric acid and sodium alginate according to the mass ratio of 13-20: 5-9.

Further, the buffer in the electroless nickel plating solution is sodium acetate.

Furthermore, the wetting agent in the chemical nickel plating solution consists of dihexyl sodium sulfosuccinate, dithiothreitol and mercaptobutyric acid according to the mass ratio of 21-23:2-5: 13-17.

Further, the stabilizer in the chemical nickel plating solution is 1, 4-phenylene bis (thiourea).

Further, the brightener in the chemical nickel plating solution consists of sodium benzene trisulfonate and benzene sulfonic acid according to the mass ratio of 4: 7.

The invention also provides a preparation method of the chemical nickel plating solution, which comprises the following steps:

s1, adding the wetting agent, the stabilizer, the dodecyl dihydroxy ethyl betaine and the N-acyl glutamic acid in the formula ratio into deionized water at room temperature, and stirring at the rotating speed of 500rpm for 20min to prepare a mixed solution A;

s2, adding nickel salt, complexing agent and buffering agent into the mixed solution A prepared in the step S1, and continuing stirring for 30min to prepare mixed solution B;

s3, adding sodium dithionate and brightener into the mixed solution B prepared in the step S2, continuing stirring for 15min, and adding a sodium carbonate solution with the mass percent of 5% to adjust the pH value to 5.0-6.0, thus obtaining the sodium dithionate-brightener.

Compared with the traditional nickel plating reducing agent sodium hypophosphite, the sodium dithionate has slightly weak reducibility, and can avoid the phenomena of uneven plating thickness, uneven surface and the like caused by too strong reducibility and too fast formation of a plating layer of the reducing agent.

The addition of the complexing agent can form stable metal complex particles with nickel salt, so that concentration polarization and electrochemical polarization are increased, the metal deposition speed is reduced, and the coating is more delicate. Through continuous research, the invention discovers that when tartaric acid and sodium alginate are added into the nickel plating solution according to a certain mass ratio, the stability constant of a complex formed by the tartaric acid and the sodium alginate and nickel ions is very large, and the dissociation rate is low, so that the deposition of the nickel ions can be well controlled, and the generation rate of a plating layer is controlled together with a reducing agent sodium dithionate, thereby being beneficial to adjusting the uniformity of a nickel plating layer.

The addition of the dodecyl dihydroxy ethyl betaine and the N-acyl glutamic acid can fully and uniformly disperse all components in the plating solution, thereby increasing the contact rate of the nickel salt and the reducing agent, accelerating the chemical plating process and ensuring the formed plating layer to have uniform thickness. In addition, the addition of the dodecyl dihydroxy ethyl betaine and the N-acyl glutamic acid can also correct the chemical plating speed reduced by the addition of the sodium dithionate, and ensure that the chemical nickel plating is carried out efficiently and high-quality.

The addition of the stabilizer 1, 4-phenylene bis (thiourea) in the formula can improve the stability of the chemical nickel plating solution, so that the chemical nickel plating solution has excellent thermal stability. The combined use of the sodium benzene trisulfonate and the benzene sulfonic acid not only can obviously reduce the grain size, but also can improve the defect that the sodium benzene trisulfonate can not reach the mirror surface gloss, and obviously improve the gloss of a plating layer and the binding force of the plating layer.

Compared with the prior art, the chemical nickel plating solution and the preparation method thereof provided by the invention have the following advantages:

(1) the chemical nickel plating solution provided by the invention has the advantages that the reduction reaction is slower, the complex formed by the complexing agent and the nickel ions is more stable, and the nickel ions can be ensured to be uniformly deposited on the surface of a plated part to form a uniform plating layer;

(2) the chemical nickel plating solution provided by the invention can form a flat and complete plating layer, and the plating layer has better brightness;

(3) the chemical nickel plating solution provided by the invention has good thermal stability, and the plating solution is not decomposed at a high temperature;

(4) the chemical nickel plating solution provided by the invention has the advantages of simple preparation method, controllable operation, lower raw material cost and easy realization of industrial production.

Detailed Description

The present invention will be further described below by way of specific embodiments, but the present invention is not limited to only the following examples. Various modifications can be made by those skilled in the art based on the basic idea of the invention, but it is within the scope of the invention as long as it does not depart from the basic idea of the invention.

In all the embodiments of the present invention, the buffer in the electroless nickel plating solution is sodium acetate; the stabilizer in the chemical nickel plating solution is 1, 4-phenylene bis (thiourea); the brightener in the chemical nickel plating solution consists of sodium benzene trisulfonate and benzene sulfonic acid in a mass ratio of 4: 7.