A kind of water-based chromium-free zinc-aluminum anticorrosion coating and preparation method thereof

Abstract

The invention discloses a water-based non-chrome-zinc-aluminum anticorrosive paint, which is prepared from a component A and a component B with the mass ratio being (1 to 1.3):1. The component A is prepared from the following materials in percentage by weight: 20 to 32 percent of zinc-aluminum powder, 15 to 25 percent of wetting agent, 1 to 5 percent of dispersing agent, and 0.5 to 1.5 percent of nanometer SiO2; the component B is prepared from the following materials in percentage by weight: 15 to 25 percent of organic silicon resin emulsion, 20 to 30 percent of deionized water, 0.5 to 1.0 percent of corrosion inhibitor, 0.05 to 0.5 percent of thickening agent, 1 to 5 percent of adhesion promoter, 0.05 to 0.5 percent of antifoaming agent, and 0.05 to 0.5 percent of coalescing agent, flatting agent and brightener. The paint provided by the invention is low in content of VOCs (Volatile Organic Chemicals), green and environmentally-friendly, high temperature resistant, high in adhesive force and good in corrosion resistance, and the anti-salt spray capability is larger than or equal to 720h.

Description

[0001] Technical field: [0002] The invention relates to the technical field of coatings, in particular to a water-based chromium-free zinc-aluminum anticorrosion coating and a preparation method thereof. [0003] Background technique: [0004] The high-efficiency protective performance of zinc-aluminum coating (Dacromet coating) mainly depends on the high content and strong toxicity of hexavalent chromium in the coating. Since the use of hexavalent chromium in various countries has been increasingly restricted, such as the European Union In July 2006, it was clearly stipulated that the use of hexavalent chromium in electronic and electrical equipment exported to the EU was prohibited. This regulation has become a technical barrier for my country's products to be exported to the EU. Chromium-free zinc-aluminum coating is a coating with anti-corrosion properties. Because it does not contain hexavalent chromium and realizes clean production, it has gradually been widely accepted ...

AI Technical Summary

Problems solved by technology

[0006] The flaky zinc-aluminum powder commonly used in zinc-aluminum coatings can form an alloy layer with the metal substrate to improve the anti-corrosion effect when baked at high temperature (above 200 ° C), while commonly used binders such as acrylic resin and titanate are difficult to withstand high temperatures ; The silane coupling agent series can form silanol bonds in a short time after hydrolysis, and can form dense -Si-O-M-bonds with metal substrates, which can play an excellent bonding effect, but the silanol bonds will become weaker with time. Self-crosslinking occurs, resulting in increased viscosity, reduced adhesion, and paint failure