The Development Of Water-based Metal Anti-corrosion Coatings And Functional

Waterborne corrosion protective coatings has been developed to replace the traditional solvent-based black paints, to realize the low pollution during the painting process in many fields. To improve the corrosion resistance of waterborn coating, we have prepd latex for base coating and top coating.1、We have prepd Epoxy-Phosphate-Styrene-Acrylic latex containing30%epoxy resin and1.2%phosphate was synthesized using styrene, butyl-acrylate, epoxy resin and phosphate functional monomer and emulsion polymerization. In this copolymer, epoxy resin possesses excellent anti-corrosion properties, chemical resistance and strong adhesion to many materials, and can be solidified with a variety of curing agents and has flexible formulation as required; on the other hand, phosphate provide the base coating with good wet-adhension and flash corrosion resistance on metal substrate.2、We also compared the effect of film-forming materials, curing agents, pigments and additives on the properties of the final coating, determined the final formulations and successfully prepared waterborne anti-corrosion coating with excellent integrate properties. The integrate properties of the coating, such as mechanical and anti-corrosion properties, were characterized by IR spectroscopy, DSC, DMA, hardness, dry/wet adhension, water resistance and salt fog resistance measurements, and the morphology of the latex coating was studied using microscope. The anti-corrosion mechanism of the aluminum dihydrogen tripolyphosphate containing coating was investigated by immersing the coating into a3.0%NaCl solution, characterizing with an electrochemical impedance spectroscopy (EIS) and analyzing the Nuquiest plot and Bode plot. The coating containing aluminum dihydrogen tripolyphosphate showed comparatively better performance after days of exposure. The result indicated that a proper PVC value is necessary for good integrate properties of the coating. In this work, the coating with PVC of42%showed the best salt-water resistance, salt fog resistance and anti-corrosion performances.3、The fluororesin grafted styrene-acrylate latex (FSA) was successfully prepared by emulsion polymerization. As a result, the fluorocarbon groups F-C have been introduced into the shell of the latex particles. The structure and properties of the FSA latex were studied by TEM, DLS, DSC and FI-IR. The results indicated that the latex was stable and the coating showed excellent contaminate resistance and weather resistance performances. The FSA coating is suitable as a waterborne anti-corrosion top coating.