Compound chromium plating additive

Abstract

The invention discloses a compound chromium plating additive, comprising organic matter and inorganic matter, wherein the organic matter comprises 1-20 g of alkansulfonic acid and / or alkanoic disulfonic acid in 1L of a standard chromium plating liquid or 0.01-0.1 g of nitrogen-containing organic compound in 1L of the standard chromium plating liquid, the inorganic matter comprises 0.001-0.01 g of a light rare earth fluoride in1L of the standard chromium plating liquid and / or 0.01-0.1 g of one of VA family element oxide, hydroxide or sulfate / According to the invention, the organic matter and the inorganic matter are added in the standard chromium plating liquid, thus the current efficiency is high , the coating has good brightness, the technology bright range is wide, the deep plating capability is good, the coating has high hardness, the anode has no corrosion, the technology is simple, and the cost is low.

Description

technical field [0001] The invention relates to the technical field of chrome plating, in particular to a composite chrome plating additive. Background technique [0002] In the chromium plating process, the first catalyst is fluorine ion or fluosilicic acid, etc., with high current efficiency and fine and bright coating, but it will corrode the anode and the coating substrate, so the accumulation of impurities in the solution is fast, the process is difficult to control, and the plating tank is easy to age. scrapped. Alkanesulphonic acid or its salts were first used in the chromium plating process by Politecnico in Milan. The coating is bright and crystallized, but the corrosion anode and bright range are narrow, and the depth capability is not good. The Hall cell test piece is 9cm, especially used Paraffin sulfonate, the anti-corrosion ability of the coating is reduced. The rare earth additives disclosed in Chinese patents CN89105414.6 and CN87102034 are all low-temperat...

AI Technical Summary

Problems solved by technology

[0002] In the chromium plating process, the first catalyst is fluorine ion or fluosilicic acid, etc., with high current efficiency and fine and bright coating, but it will corrode the anode and the coating substrate, so the accumulation of impurities in the solution is fast, the process is difficult to control, and the plating tank is easy to age. scrapped

Alkanesulphonic acid or its salts were first used in the chromium plating process by Politecnico in Milan. The coating is bright and crystallized, but the corrosion anode and bright range are narrow, and the depth capability is not good. The Hall cell test piece is 9cm, especially used Paraffin sulfonate, the anti-corrosion ability of the coating is reduced

The rare earth additives disclosed in Chinese patents CN89105414.6 and CN87102034 are all low-temperature and low-concentration chromium plating processes, but it is difficult to control process parameters when they are changed to standard electroplating solutions

[0003] With iodine and other halogens as additives, the current efficiency is improved, because the iodine releasing agent has an activation effect on the coating substrate, but the coating bonding force is poor in the high current area, the appearance is dark gray, semi-bright, and the brightness range is narrow