Nickel-free black tin cobalt alloy plating solution and electroplating technology by using same

Abstract

The invention relates to a nickel-free black tin cobalt alloy plating solution and an electroplating technology by using same. The parameters and contents of all components of the plating solution are as follows: the content of tin ions in a tin salt is 0.05-6g/L; the content of cobalt ions in a cobalt salt is 0.05-0.8g/L; the content of third metallic ions is 0.02-50g/L; the content of a complexing agent is 0.1-180g/L; the content of a blacking agent is 0.1-50g/L; the content of a PH buffer is 5-300g/L; the baume degree of the plating solution is 6-250; the temperature is 20-55 DEG C; and PH is 9-13. According to the technology provided by the invention, tin is taken as a main alloy layer and few cobalt and third and fourth metal ions are added in tin to form a ternary or quaternary alloy system; the cobalt content in the common black tin cobalt alloy plating solution excesses 8g/L, but the cobalt content is reduced to 0.05g/L according to the new electroplating technology provided by the invention; the special biodegradable or non-biodegradable stabilizing complexing agent and PH buffer are used, so that the production cost is lowered; and the nickel-free black tin cobalt alloy plating solution meets the limitation requirement on CO in the European Union Rosh standard, Germany LMBG standard, Mattel children toy standard, European Oeko-Tex Standard 100 standard and the like.

Description

technical field [0001] The invention relates to the technical field of alloy electroplating, in particular to a nickel-free black tin-cobalt-based alloy plating solution and an electroplating process using the plating solution. This technology is suitable for consumer hardware parts, electronic products, personal digital products, clothing accessories, children's toys, luggage, jewelry, furniture, food utensils and other items that are in close contact with the human body. Background technique [0002] At present, the tin-cobalt alloy electroplating process has been widely used in the electroplating of consumer hardware parts, electronic products, personal digital products, clothing accessories, children's toys, bags, jewelry, furniture, food utensils and other items that are in close contact with the human body. , implemented an electroplating environment-friendly lead-free, nickel-free and cyanide-free tin-cobalt alloy coating to obtain a black bright alloy environmental p...

AI Technical Summary

Problems solved by technology

The common tin-cobalt alloy electroplating process at this stage has the following problems: 1. The cobalt content exceeds 5g / L, generally 8 g / L, and the cost of the plating solution is high

4. The Baume of the plating solution is as high as 22 or more, the viscosity of the plating solution is high, the water is serious, and a large amount of cobalt, tin metal ions and potassium pyrophosphate are lost, which increases the cost meaninglessly; 5. The high plating temperature wastes energy

6. Cobalt has certain radioactivity. (For example, cobalt 60 is a nuclear radiation substance). The 15 highly concerned substances in the EU REACH directive, which came into effect on June 1, 2007, include the requirements for cobalt chloride, which requires limiting the amount of cobalt

7. The plating solution is difficult to control, and the effect in the low current area is not good. It often misses plating and turns yellow. Even if the workers have high technical level, they need to adjust the plating solution frequently, resulting in waste of raw materials

7. It is difficult to control the depth and color of the plating layer, and the composition of the plating solution is adjusted entirely based on experience

8. Due to the poor effect in the low-current area of ​​the coating, when producing black and white mandarin duck-color effects without nickel and black nickel, the electroplating time is long, the coating in the high-current area is very thick, and the time for drawing and rubbing is very long, so the thickness of the underlying coating is required to be very thick , a lot of waste

[0003] Although the current black tin-cobalt alloy electroplating process can meet the EU and U.S. food standards about prohibiting the inclusion of heavy metals in the electroplating layer, the cobalt content in the plating solution is too high, which may not meet the requirements of future environmental protection electroplating, and The cost of the whole electroplating system is high