Method for preparing inorganic-organic composite passivation solution

Abstract

The invention provides a method for preparing an inorganic-organic composite passivation solution. The method comprises the steps that nanosilicon dioxide is firstly added into water, polyvinyl chloride, citric acid and sodium bicarbonate are added, temperature is raised, a hydrochloric acid aqueous solution is added dropwise, stirring is carried out, the temperature is reduced to room temperature, filtering is carried out, and modified nanosilicon dioxide is obtained; then titanyl sulfate and sodium vanadate are added into H2O2, dispersing is carried out, and a complexing solution is obtained; then sodium molybdate is added into water, pH is adjusted to be neutral, the modified nanosilicon dioxide, accelerant and a film-forming agent are added, and an inorganic salt passivation solution is obtained; and finally a silane coupling agent KH570 and a silane coupling agent KH858 are added into ethanol water, pH is adjusted, the inorganic salt passivation solution is added, ultrasonic treatment is carried out, and the inorganic-organic composite passivation solution is obtained. The inorganic-organic composite passivation solution is an environment-friendly product and contains no heavy metal ions or volatile organic solvents polluting the environment; the passivation treatment process is simple and low in cost; and the inorganic-organic composite passivation solution can gradually replace a traditional chromate passivation solution, and environment-friendly production of galvanized plate passivation is achieved.

Description

technical field [0001] The invention belongs to the technical field of passivation solution, and in particular relates to a preparation method of an inorganic-organic composite passivation solution. Background technique [0002] Hot-dip galvanized steel sheet is to immerse the thin steel sheet in the molten zinc tank to make the surface of the thin steel sheet adhered to a layer of zinc. The galvanized steel sheet is mainly produced by continuous galvanizing process, that is, the coiled steel sheet is continuously immersed in the molten The galvanized steel sheet is made in a galvanized tank with zinc. Hot-dip galvanizing has the advantages of simple process, easy maintenance of equipment, uniform coating of the produced plate, and good corrosion resistance. [0003] At present, chromium-free passivation is often used in the production process of hot-dip galvanized steel sheets. Chromium-free passivation is mainly divided into inorganic passivation and organic passivation. I...

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Problems solved by technology

[0003] At present, chromium-free passivation is often used in the production process of hot-dip galvanized steel sheets. Chromium-free passivation is mainly divided into inorganic passivation and organic passivation. If inorganic passivation is used alone, the corrosion resistance of the passivated film layer meets It does not meet the requirements of the national standard, and the formed inorganic salt film layer is relatively thin, and the acid resistance, alkali resistance and stamping resistance can not meet the requirements of industrial production, so that it cannot be used in large-scale production; the adhesion of organic passivation is poor, During the drying and curing process, the film layer is prone to cracks, its welding performance is not good, and it is difficult to meet user requirements, and it cannot be applied in large-scale industrial production.