Zinc layer surface chromium-free environmental protection passivation processing liquid and preparation method and use thereof

Abstract

The invention provides zinc layer surface chromium-free environmental protection passivation processing liquid and a preparation method and use thereof. The passivation processing liquid comprises: 1-10% of special doped resin, 1-8% of a coupling agent, 1-10% of water-based nanometer sol, 0.5-5% of modified hydroxyl nanometer layered silicate powder, 0.1-3% of a metal chelating agent, 5-20% of a diluent, 0.5-3% of a dispersing agent, 0.5-3% of a thickening agent, 0.3-2% of a PH adjusting agent, and the rest of water. Through using a resin doping process, specially hybridizing the resin as a film forming agent, and applying the coupling agent, an organic high molecular material is embedded into an inorganic SiO2 netty three-dimensional film layer, and the netty three-dimensional film layeris further filled and wrapped by using modified hydroxyl nanometer layered silicate to implement inorganic-organic compound passivation, so that the compatibility problem of organic components and inorganic components is solved, and the stability of the passivation processing liquid is improved; and a compact corrosion-resistant passivation layer can be formed when the passivation processing liquid is coated on the surface of a zinc layer, so that the passivation processing liquid has the advantages of low film forming and drying temperature, convenient processing process, high solution stability, acid and alkali corrosion resistance and capability of implementing chromium-free environmental protection processing.

Description

technical field [0001] The invention relates to the field of metal surface treatment, in particular to a chromium-free and environment-friendly passivation treatment solution for the surface of a zinc layer, a preparation method and application thereof. Background technique [0002] The problem of corrosion failure of metal substrates is an important factor affecting the development of the national economy, especially in aviation, electric power, transportation, machinery and other industries. The performance failure caused by the corrosion of metal components will cause equipment and production lines to fail. The loss of people's lives and property occurs from time to time, which is a problem that government departments in various places pay close attention to and attach great importance to. [0003] The use of zinc metal to treat the surface of metal substrates with a protective layer is one of the most common and effective anti-corrosion methods today. Its main processes ...

AI Technical Summary

Problems solved by technology

The traditional passivation process mainly uses chromic anhydride passivation solution containing hexavalent chromium, and its passivation layer has a certain self-healing property. However, due to the high carcinogenicity of hexavalent chromium to the human body, the passivation sealing solution is now completely banned. Contains hexavalent chromium ions in it, and it is replaced by trivalent chromium, but the treatment effect of trivalent chromium passivation solution is not very satisfactory, and the passivation layer formed by it will be converted into hexavalent chromium under certain conditions, so Trivalent chromium passivation is not a completely environmentally friendly post-treatment process

[0005] Therefore, there is an urgent need for a chromium-free and environmentally friendly passivation treatment method at this stage. There are many studies on chromium-free passivation at home and abroad, mainly including inorganic passivation technology, organic passivation technology and inorganic-organic compound passivation technology. Inorganic passivation technologies mainly include passivation of molybdate, tungstate, titanate, zirconate, manganate, modified silicate, and rare earth metal salt; The film layer is relatively thin, with poor elasticity and toughness, resulting in insufficient film tension, poor compactness and continuity

Organic passivation is mainly organic acid passivation, organosilane passivation, polymer material passivation film, etc., but after organic passivation, polymer materials have poor adhesion to metal substrates, and outdoor ultraviolet aging resistance is not good, so the current environmental protection Chromium-free passivation research is more inclined to the inorganic-organic composite passivation process. The inorganic-organic composite passivation process uses inorganic components to improve the aging resistance and low-temperature rapid film formation of the film, and improves the toughness of the film layer through organic components. Layer tension, improve acid and alkali resistance, so that the composite passivation film has many characteristics of environmental protection and corrosion resistance, but the problems existing in the inorganic-organic composite passivation process are mainly manifested in the compatibility of organic components and inorganic components. Combining the organic-inorganic in a stable way, improving the stability of the passivating agent, and ensuring industrial production are the main directions of inorganic-organic composite passivation research at this stage

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