Silica sol synthesis process and precautions for its application in coatings

Brief description of silicone rubber synthesis process: Sand or silicon reduction temperature, monomer - > 300% copper catalyst, organosilicon and chloromethane form a mixture of methyl chlorosilane (mono, binary or ternary)- dimethyl chlorosilane is distilled and separated - dimethyl chlorosilane hydrolyzes silane and rapid linear or cyclic siloxane - the synthesis of linear siloxane forms quaternary dimethyl donut (D4) with the help of potassium hydroxide (KOH). In the presence of KOH,D4 polymerizes. The chain termination process is completed.

The preparation process of silica sol inorganic polymer coating is not particularly different from that of other coatings, but silica sol should be added gradually; otherwise, the coating will undergo a qualitative change. The following preparation process can be referred to

　　

Film-forming additives (commonly used ones include zinc oxide, butyl acetate, methyl silicate sodium, etc.) are added to the reaction vessel, and a certain amount of water is added for mixing. Then, surfactants (sodium benzenesulfonate), thickeners (hydroxyethyl cellulose CMC, etc.), dispersants (sodium hapetaphosphate), defoamers (tributyl phosphate), and other auxiliary equipment are added. Then slowly add silica gel sol, body pigment and color paste. It can be finely ground with a sanding machine or colloid, and coarse-grained materials can be added as needed for production. The pH value of the coating is between 8.5 and 10.