Inorganic coatings, conforming coatings are developing in the direction of green

Organic coatings dominate the market, but with the advancement of technology, inorganic coatings and organic-inorganic composite coatings have gradually emerged. Inorganic coatings do not use organic polymers as the film-forming base material, but mainly use inorganic compounds such as silicate, silica sol or inorganic phosphonate as the main film-forming base material, with pigments, fillers and no more than 5% of the total coating Coatings composed of additives, inorganic curing agents, etc. The film-forming mechanism of inorganic coatings is mainly silicate reacts with water to generate colloidal silica and hydroxide. As the water decreases, the solid content increases. The colloidal silica polymerizes with silicon-oxygen bonds to polymerize silica gel, which is finally dehydrated. Condensation to form a silica network structure.

Resource advantages and environmental protection advantages of inorganic coatings

Most of the base materials of inorganic coatings are made of extremely common and abundant natural ores or metal oxides as raw materials, and the production process is not complicated, and the energy consumption is relatively low. Most inorganic coatings use Water as the dispersion medium, which fundamentally solves the environmental pollution caused by solvents in the coating industry. The inorganic film-forming base material itself is non-toxic, except for the volatilization of water, there is no harmful problem of VOC such as free monomer, and it will not release harmful substances to the atmosphere under flame or high temperature.

In recent years, inorganic coatings have been widely used in the fields of interior and exterior wall building decoration, rust prevention, bridge pier protection and high temperature protection, and a variety of functional inorganic coatings have been developed accordingly. Such as high temperature resistant inorganic coatings, some temperature resistant materials are added to the coating, such as low melting point glass powder, aluminum powder, pearl powder and other substances. The melting point of low-melting glass is relatively low in comparison, and it can be melted under low heating conditions to form an enamel body, so as to achieve the high temperature stage of silicone resin coating, from pure low-temperature resin film formation to high-temperature short glass "Secondary film formation" of powder, thereby forming an inorganic high temperature resistant coating.

Aluminum powder has scaly and spherical shapes. Because of its flaky microstructure, it can form an alloy layer under high temperature conditions. The alloy layer can greatly improve the bonding ability of the coating and the substrate, thereby improving the adhesion and mechanical properties, and improving The temperature resistance of the coating makes inorganic coatings have excellent temperature resistance and weather resistance. Inorganic anti-corrosion coating is the addition of Graphene oxide, alcohol-soluble alkyl silicate, silicate and other substances to inorganic coatings to prevent corrosion of metal materials. Graphene oxide is oxidized and peeled off by graphite powder in a single graphene sheet. The introduction of Oxygen-containing functional groups improves the dispersibility of graphene in the substrate, while retaining the layered structure of graphite to make the coating have barrier properties and improve the ability of the coating to block the penetration of corrosion ions into the corrosion substrate.

Application of inorganic coatings in architecture

Inorganic coatings have been used well in many famous buildings, including my country’s Beijing Sub-City, Shanghai’s Olympic Garden, Hong Kong’s new airport and subway, the White House of the United States, the Buckingham Palace in the United Kingdom, the Arabian Palace, the Wisdom Church in Germany and Siemens Headquarters and Singapore Presidential Palace, etc.

Inorganic coatings have many advantages, but there are also problems such as insufficient decorative effects, weak adhesion, and high production costs for certain inorganic coatings. In addition, there is currently no good reference standard for inorganic coatings in China. The existing standards cannot reflect the characteristics of inorganic coatings. It is recommended to screen out the performance by testing organic content, scrubbing resistance, water vapor transmission rate and other related experimental tests. Good inorganic coating.

Therefore, it is recommended that coating manufacturers and scientific research units expand related research work on the performance development and application construction of inorganic coatings, and further conform to the development of green, safe and pollution-free coatings.