Due to the non-nickel ion emission, many original nickel-tin double salt coloring processes have been changed to mono-tin salt coloring processes. But Single Tin Salt is difficult to be dark and black, which puzzles many enterprises and limits the application of single tin salt coloring process. This product is a single tin salt system electrolytic coloring blackening agent, a perfect replacement of the nickel salt, nickel-tin double salt to reach the imitation of stainless steel-bronze-champagne-bronze-bronze-black this series of colors. At the same time this product does not contain heavy metals, non-toxic, harmless, green environmental protection. This product should be used together with CWF-7302. The coloring solution is more stable and the coloring effect is better. This product is made up of many kinds of black accelerant and accelerant. It has the following characteristics: 1. Break the traditional single-tin salt, break the dark barrier, can be true black, blackness is no less than nickel-tin double salt. After coloring, the color is full, the background color can be adjusted according to the customer's requirements. 3. The coloring solution does not contain nickel and other heavy metal ions, which can protect the environment and reduce the cost of wastewater treatment. 4, does not affect the light color, coloring temperature range is wide, not easy to get gray, process control is convenient. 5. When changing the tinting bath, there is no need to discharge the whole bath. On the basis of the traditional nickel-tin bath, adding CWF-7304 without adding nickel salt, the tinting bath is gradually transformed into the tinting bath. Slotting parameter