Preparation And Performance Of Golden And Black Coatings With Silicate As Main Film Forming Substance

Water-borne inorganic zinc-rich silicate coating with inorganic silicate as the main film-forming substance, zinc powder as antirust pigment and curing agent, is widely used in ocean and atmospheric anticorrosion for its heat resistance, abrasion resistance and weather resistance. However, its decoration function is seriously limited when used in anticorrosive field owing to its monotonous color and thick film.In this paper, golden and black coatings were prepared with inorganic silicate as main film-forming substance, which had the performance of certain anticorrosive and decoration. The effects of pigment content, curing temperature and coating layer to the performance of the golden coating were studied by scanning electron microscope (SEM), pencil hardness test, adhesion test, water resistance test, neutral salt spray test, saltwater resistance test, electrochemical impedance spectroscopy (EIS), electrochemical linear polarization and other methods. The parameters for the golden coating were optimized (10mass% golden pearl pigmen in silicate, 80℃for the cured temperature of the first coating layer, 140℃for the cured temperature of the second coating layer) The electrochemical performances of the golden coating were also studied in 3.5mass% NaCl solution.Water-borne inorganic silicate golden coating modified by aerosil was prepared and the effect of the aerosil was studied. The results showed that the 1.5mass% aerosil could notably improve the compactness, corrosion resistance and heat resistance of golden coating.Black silicate coating was prepared with silicate as the film-forming substance, water-borne polyurethane emulsion as the film-forming additive, zinc powder and magnetic iron oxide powder as the pigments. The influences of the pretreat process, the proportion of zinc powder, magnetic iron oxide powder, silicate and polyurethane emulsion were studied. The optimized parameters for the golden coating were obtained (zinc powder : magnetic iron oxide powder = 1:4, 20mass% addition of water-borne polyurethane emulsion).