Novel environment-friendly chromium-free passivator and preparation method thereof

Abstract

The invention provides a novel environment-friendly chromium-free passivator. The passivator comprises, by weight, 30-35 parts of water-based acrylic resin, 15-20 parts of laponite, 3.5-4 parts of citric acid, 10-12 parts of phytic acid, 7-8 parts of zinc chloride, 3-5 parts of ethylene glycol phenyl ether, 8-12 parts of glycine, 3.5-4 parts of sodium molybdate, 8-12 parts of polyaspartic acid, 4-6 parts of oxidized starch, 4-7 parts of sodium citrate, 3-3.5 parts of amine oxide and 50-55 parts of deionized water. The passivator can form a dense protective film on the surface of a plated part,the formed protective film has excellent adhesion and can be closely attached to the surface of the plated part, and thus the corrosion resistance and wear resistance of the plated part are greatly improved.

Description

technical field [0001] The invention relates to the technical field of post-treatment of material surfaces, in particular to a novel environment-friendly chromium-free passivator. Background technique [0002] Electro-galvanizing and hot-dip galvanizing are effective ways to improve the corrosion resistance of the surface of steel materials. They are widely used in all aspects of life at present, but in humid environments, especially in hot and humid environments, the galvanized layer is prone to corrosion, making the coating A dark gray or white loose corrosion product - white rust is formed on the surface, and red rust will appear after a long time, thus losing the anti-corrosion effect; Passivation treatment is carried out on the coating to form a dense passivation film on the surface of the coating, improve the corrosion resistance of the coating, and increase the service life of the workpiece. [0003] The traditional galvanizing process mostly adopts the solution with...

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Problems solved by technology

[0002] Electro-galvanizing and hot-dip galvanizing are effective ways to improve the corrosion resistance of the surface of steel materials. They are widely used in all aspects of life at present, but in humid environments, especially in hot and humid environments, the galvanized layer is prone to corrosion, making the coating A dark gray or white loose corrosion product - white rust is formed on the surface, and red rust will appear after a long time, thus losing the anti-corrosion effect; Passivate the coating to form a dense passivation film on the surface of the coating, improve the corrosion resistance of the coating, and increase the service life of the workpiece

[0003] Most of the traditional galvanizing process adopts passivation treatment with hexavalent chromium or trivalent chromium as the main component. However, due to the high toxicity of hexavalent chromium to the human body, governments of various countries have strictly restricted its use, especially in the European Union. The ROHS directive clearly prohibits the use of any parts and products treated with hexavalent chromium passivation technology; although trivalent chromium is less toxic, after a period of use, trivalent chromium will be oxidized to hexavalent chromium, so use trivalent chromium The chromium passivation process cannot fundamentally solve the toxicity problem of hexavalent chromium