Chromium-free passivator for copper part

Abstract

Disclosed is chromium-free passivator for a copper part. In terms of a raw material formula, the chromium-free passivator for the copper part comprises, by mass, 50-80 parts of acetic acid, 30-50 parts of oxalic acid, 5-10 parts of sodium citrate, 3-5 parts of ammonium dihydrogen phosphate, 5-8 parts of disodium hydrogen phosphate, 4-6 parts of dicalcium phosphate, 3-5 parts of sodium carboxymethyl starch, 5-10 parts of poly-aspartic acid, 6-10 parts of 1-hydroxyethylene-1,1-diphosphonic acid, 5-10 parts of diethylenetriamine penta methylene phosphonic acid, 5-10 parts of methyl methacrylate, 3-5 parts of ammonium sulfamate, 8-10 parts of tert-butyl hydroperoxide and 150-200 parts of purified water. The chromium-free passivator for the copper part enables the copper part to keep good corrosion resistance, can facilitate environmental protection and simplification of the operating technology, improves the production efficiency, and avoids the phenomena that due to the fact that a large amount of poisonous acid mist or chromic acid is generated when workpieces are processed through acid pickling, operators are harmed, and the environment is polluted.

Description

technical field [0001] The invention relates to the technical field of a passivating agent, in particular to a chromium-free passivating agent for copper parts. Background technique [0002] At present, because copper and its alloys have excellent thermal conductivity, they are widely used in the refrigeration industry, but because O2, CO2, H2S, SO2 in the air easily react with copper, the surface turns black, affecting its appearance and Thermal conductivity, so copper refrigeration pipes must be passivated. At present, the passivation process commonly used by domestic refrigeration arm production plants is chromic acid passivation, which is for the purpose of chromic acid passivation treatment can form a mixture oxide film of chromium / base metal. However, chromic acid and its salts are highly toxic and carcinogenic, and the treatment of wastewater containing hexavalent chromium is more complicated. Small-scale enterprises generally do not have the conditions to treat wast...

AI Technical Summary

Problems solved by technology

However, chromic acid and its salts are highly toxic and carcinogenic, and the treatment of wastewater containing hexavalent chromium is more complicated. Small-scale enterprises generally do not have the conditions to treat wastewater containing chromium, and they are unwilling to treat it and discharge it directly. , has caused serious po...