In the past, most of the silicone resin coating products used chlorosilane as the monomer, mainly because of its large yield and low cost, but with the development of the silicone industry, alkoxylsilane gradually replaced chlorosilane, mainly because: SI-OR hydrolysis rate is lower than SI-C1, the reaction is easy to control, good repeatability; The by-product of hydrolysis is alcohol, so that the reaction process can be added less or no organic solvent dilution reactants; No hydrochloric acid is generated in the hydrolysis process, which reduces the corrosion of equipment and the treatment intensity of organic wastewater.
At present, in addition to the common silicone monomer, many kinds of silane coupling agents are also used in the synthesis of silicone resin, such as KH 550, KH560 and so on
In addition to the type and amount of raw material monomer have a great impact on the final product performance of silicone resin coatings, the nature of catalyst, solvent, and the amount of process conditions will have an impact. In the process of coating preparation, the catalyst can hydrolyze and polycondensation of monomer, but it is not conducive to the storage of coating. The solvent directly affects the leveling of the coating on the surface of the substrate and the drying speed of the coating, thereby affecting the surface condition of the coating. Commonly used catalysts are hydrochloric acid, acetic acid, ammonia water, etc.; Commonly used organic solvents are benzene, toluene, xylene, acetone, methyl ethyl ketone, isobutyl ketone, propanol, isopropanol, n-butanol, ethyl acetate, butyl acetate and so on.