Modification And Dispersion Of Nanometer Calcium Carbonate And Preparation Of Its Composite Coatings

Nanometer calcium carbonate (abbreviated to nano-CaCO₃), which has been industrialized with larger volume of production and lower price, is a functional nanometer material. It is applied widely to rubber, plastics, coatings, printing ink, paper industries, but its lagging applicable technology has hindered seriously the development of nano-CaCO₃ industry in our country. In order to enlarge the application field of nano-CaCO₃ and improve the performance and quality of present coatings, the modification and dispersion of nano-CaCO₃ applied to coatings, which is the key technology, was studied systematically by experiment. Nano-CaCO₃ composite acrylic, epoxy and architectural coatings were prepared respectively and the rheological property of nano-CaCO₃ slurry and its composite coatings was studied.Nano-CaCO₃ applied to oil and water coatings was modified with the compound modifiers and the modifier synthesized by the author respectively. The technological conditions were optimized and the modification mechanism of nano-CaCO₃ was also investigated. The modified effect of nano-CaCO₃ was proved by thermal analysis, FTIR and TEM. Especially the modified technology of nano-CaCO₃ applied to water coatings has already been put into operation in Anhui.The dispersions of modified nano-CaCO₃ in acrylic resin, epoxy resin and water were studied respectively by experiments. The dispersion technological conditions were optimized and three kinds of modified nano-CaCO₃ slurry were prepared. These slurries have good storage stability, small average diameter of nano-CaCO₃ and uniform dispersion. It has laid the foundations of the preparation of nano-CaCO₃ composite coatings.Nano-CaCO₃ composite acrylic coatings, composite epoxy coatings and composite architectural coatings were prepared with the modified nano-CaCO₃ slurry and their main performance was also measured. The results show that the properties of composite epoxy coatings, including light resistance, water resistance, dirt resistance and stability during storage and the properties of composite epoxy coatings, including water resistance, salt water resistance, salt spray resistance and storage stability, were greatly improved. The properties of architectural coatings, including...