Influence of Organic-inorganic Hybrid on Properties of Inorganic Zinc-rich Coatings

First, a series of potassium silicate solution with different modulus were prepared from potassium silicate and silica sol. Then, the catalytic hydrolysis of the silicone-acrylic emulsion was carried out in the presence of tetramethylammonium hydroxide. Subsequently, the reactants of potassium silicate solution and silica sol were modified by the moderately hydrolyzed silicone-acrylic emulsion and used as a coating base material. Finally, the coating base material mixed with zinc powder with a mass ratio of 1.0: 2.6 and gave a water-based inorganic potassium silicate zinc-rich coating by organic-inorganic hybridization method. The influences of modulus of potassium silicate solution, solid content of potassium silicate solution and amount of moderately hydrolyzed silica-acrylic emulsion on the properties of waterborne inorganic zinc-rich coating were investigated. The related mechanism was also discussed. The results indicated that when the modulus of potassium silicate was 3.3, the solid content of potassium silicate solution was 25.0%, and the amount of moderately hydrolyzed silicone-acrylic emulsion was 5%~10% of solid content of potassium silicate solution, the film's hardness flexibility and adhesion were 5H, 4 mm and grade 1, respectively. It exhibited no change after the film was immersed in water and 5% sodium chloride solution for 7 days, respectively. The coatings showed the best comprehensive performance. © 2018, Editorial Office of FINE CHEMICALS. All right reserved.