Composite surface treatment agent

Abstract

The invention discloses a composite surface treatment agent used for surface treatment before metallic electrophoretic coating. The composite surface treatment agent is characterized by being prepared from, by mass, 30 parts of gamma-aminopropyl methyldimethoxysilane, 20 parts of 2-(3,4-epoxy cyclohexyl)ethyltriethoxysilane, 10-20 parts of Co2O3 nanoparticles, 10 parts of zirconium oxychloride, 5 parts of titanyl sulfate and the balance water. According to the composite surface treatment agent, harmful elements such as phosphorus are not contained, and therefore pollution can not be caused to the environment in the using process; compared with an existing phosphate-free surface treatment agent, metal treated with the existing phosphate-free surface treatment agent is thin in surface formed film, the physical bonding capacity of the metal and electrophoretic paint is poor, metal treated with the composite surface treatment agent is thick in surface formed film, and then the physical bonding capacity of the metal and the electrophoretic paint is enhanced; therefore, the corrosion resistance and the throwing power of the metal obtained after electrophoretic coating are greatly improved.

Description

technical field [0001] The invention relates to a composite surface treatment agent. Background technique [0002] Metal materials usually need surface treatment before electrophoretic coating to enhance the adhesion between metal and paint. At present, the metal surface treatment technology before electrophoretic coating mostly adopts phosphating treatment process. However, because this treatment method contains harmful heavy metal ions such as zinc and nickel and chemical components such as phosphorus, and will produce a large amount of phosphating slag during the treatment process, it will cause great harm to the environment. Furthermore, the phosphating treatment technology consumes The performance is relatively large, and the degree of dependence on the previous surface adjustment process is large, which also increases the processing cost and management difficulty. As a non-phosphorus pretreatment technology that can replace the traditional phosphating treatment, there...

AI Technical Summary

Problems solved by technology

However, the thickness of the film formed by these two phosphorus-free pretreatment methods on the metal surface is much thinner than that of the traditional phosphating film, and the corrosion resistance of the film layer and the physical bonding ability with the subsequent coating are also weak. There is the disadvantage of low throwing power when the treated metal is used in conjunction with ordinary electrophoretic coatings, which will cause thinner electrophoretic paint films in the inner cavity of the workpiece, which will lead to corrosion and perforation. Therefore, the current two phosphorus-free pretreatment methods It is far from the level of traditional phosphating technology. Therefore, a method that can effectively avoid the environmental pollution caused by phosphorus treatment process can also form a thicker film on the treated metal surface, which can effectively improve the relationship between metal and phosphating. It is necessary to develop a surface treatment agent for the physical binding ability of subsequent electrophoretic coatings