Chitosan modified surface treatment liquid for galvanized color-coated board and preparation method thereof

Abstract

The invention provides a chitosan modified surface treatment liquid for a galvanized color-coated board and a preparation method thereof and belongs to the technical field of galvanized color-coated board surface treatment. The surface treatment liquid provided by the invention has the following components by weight percent: 0.2-1 of chitosan, 1-10 of organic silicon, 0.05-0.2 of inorganic corrosion inhibitor, 0.075-0.3 of oxidizing agent, 0.005-0.02 of complexing agent, 0.01-0.05 of inorganic filling material, a proper amount of pH regulating agent and the balance of deionized water. For a container, the corrosion inhibitor is intelligently released according to the destructive degree of a metal surface. The chitosan modified surface treatment liquid is characterized in that chitosan is not only used as a main film substance but also as a container for storing the corrosion inhibitor, and chitosan can intelligently release the corrosion inhibitor according to the destructive degree of the metal surface, thereby forming an intelligent paint film on the metal surface. In the invention, a chitosan raw material is sufficiently supplied and has low price, thus being beneficial to reduction of cost. The chitosan modified surface treatment liquid provided by the invention dose not contain chromium of any valence state and is an environmentally-friendly chromium-free passivating liquid.

Description

Technical field [0001] The invention belongs to the technical field of surface treatment of galvanized color-coated sheets, and specifically relates to a chitosan modified surface treatment liquid for galvanized color-coated sheets and a preparation method thereof. technical background [0002] In 1973, American environmental scientist Donella Meadows pointed out in "The Limits to Growth" that the progress of human civilization cannot do without chromium, because it is widely used in leather, metal production, polishing, [0003] Corrosion protection and other fields. However, the European Union formally announced the "Directive on the Prohibition of Certain Hazardous Substances in Electrical and Electronic Equipment" (RoHS) in 2003, and products containing hexavalent chromium are subject to strict restrictions. Therefore, experts and scholars from all over the world have turned their research directions to Environmentally friendly corrosion inhibitors replace toxic carcinogenic c...

AI Technical Summary

Problems solved by technology

As the world pays more and more attention to the problems of the earth's environment, it has become a trend to develop water-based chromium-free passivators that are environmentally friendly, energy-saving, and low-cost. The development of the preparation method, the generality of this kind of passivation solution is that the water-soluble organic polymer resin is the main film-forming substance, compounded with silane coupling agent, supplemented by inorganic passivation agent and inorganic corrosion inhibitor. The coating film adhesion, corrosion resistance and other performance indicators are almost comparable to those of chromate. However, the resins used in this type of treatment liquid are high-molecular organic synthetic polymers, and the organic polymers must be surface-modified. It is soluble in water only after the galvanized color coating treatment, and the adhesion, water resistance and brush resistance of the paint film formed after galvanized color coating are affected to a certain extent

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