Self-cleaning super-hydrophobic conversion film on metal matrix, preparation method and film-forming agent of self-cleaning super-hydrophobic conversion film

Abstract

The invention relates to a self-cleaning super-hydrophobic conversion film on a metal matrix and a preparation method and a film-forming agent of the self-cleaning super-hydrophobic conversion film. The method comprises the following steps that the film-forming agent of the conversion film is obtained, and the film-forming agent of the conversion film mainly comprises the following components: a silane crosslinking agent, a corrosion inhibitor, an ion auxiliary agent, a film-forming accelerant, a surface energy regulator and a pH regulator; the ion auxiliary agent is a colored metal salt which can be subjected to a replacement reaction with the metal matrix, and the film-forming accelerant can promote a bonding reaction between silane and the metal matrix and can oxidize metal elements in the ion auxiliary agent at the same time; and the surface energy regulator can generate salt with a specific color with oxidized metal elements introduced by the ion auxiliary agent or oxides thereof, the salt grows on the surface of the metal matrix to form a film, and the salt and the silane / corrosion inhibitor are mutually crosslinked and synergistically protected in the film forming process, so that a compact film layer is formed on the surface of the metal matrix. The conversion film has a special color appearance and a lotus leaf-like effect, and has the advantages of environmental protection, simple preparation process, low cost and the like.

Description

technical field [0001] The invention belongs to the technical field of metal surface treatment engineering, and in particular relates to a self-cleaning superhydrophobic conversion film on a metal substrate, a preparation method thereof, and a film-forming agent. Background technique [0002] The harm caused by metal corrosion is serious and common, and the corrosion of metals or alloys is still the focus of researchers. Zinc and its alloys have been widely used as anti-corrosion coating materials for steel, which can provide both physical barrier protection and sacrificial anode protection for steel substrates. In order to prevent the rapid corrosion of the galvanized layer and improve the corrosion resistance of the workpiece, chromate passivation and phosphating are usually used for surface treatment. However, phosphorus element is easy to cause eutrophication of water body, leading to water pollution, while Cr 6+ (VI) Chromate is highly toxic, harmful to human health, ...

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Problems solved by technology

[0004] Patent (CN105002487A) discloses a chromium-free passivator after metal plating with hydrophobic surface properties, which is mainly composed of silane coupling agent, nanomaterial, titanate coupling agent and water-based wax, although it has A certain degree of hydrophobicity but the passivation film is not self-healing, the corrosion resistance is not good, and it is difficult to provide long-term protection for the metal

Patent (CN107893223A) discloses a method for preparing a superhydrophobic phosphating composite film with high corrosion resistance and self-cleaning on the surface of zinc layer. The superhydrophobic phosphating composite film is obtained by hydrophobic modification treatment with a neutralizing agent. This preparation method involves two main steps of rough structure and low surface energy modification. pollution problem

[0005] Although there are related patents that use different methods to prepare superhydrophobic surfaces on the surface of metal substrates, these technologies have the disadvantages of requiring special conditions and processing techniques, taking a long time, and low preparation efficiency, which restricts their large-scale preparation and development.

[0006] As far as we know, there are few reports on the preparation of superhydrophobic surfaces with certain comprehensive properties on the surface of zinc or galvanized steel by oxidative self-assembly method.

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