3-Glycidoxypropyltrimethoxysilane is the earliest widely used coupling agent with a history of more than 40 years up to now. One end of the structure has active groups, such as amino group and vinyl group, which can react with epoxy, phenolic, polyester and other synthetic resin molecules. The other end is connected with silicon alkoxy group (such as methoxyl, ethoxyl, etc.) or chlorine atoms, these groups in aqueous solution or the presence of water in the air, hydrolyzed to generate hydroxyl with glass, minerals, inorganic filler surface reaction, the formation of reactive silanol. Therefore, silane coupling agent is often used in silicate filled epoxy, phenolic, polyester resin and other systems. In addition, it can also be used in FRP production to improve its mechanical strength and resistance to wet environment. The organic groups of silane coupling agent are selective for the reaction of synthetic resin. Generally, these organic groups lack sufficient reactivity with polyethylene, polypropylene, polystyrene and other synthetic resins, so the coupling effect is poor. In recent years, new silane coupling agents with good coupling effect on polyolefin have been developed, but due to cost and other properties, their application is not widely used in Chemicalbook. Silane coupling agent is also known as silane primer; Bottom coating agent. The general formula is Y(CH2)nSiX3, an organosilicon monomer with more than two different reaction groups in the molecule, which can chemically bond with organic and inorganic materials (coupling) to increase the adhesion of the two materials. N in the general formula is an integer ranging from 0 to 3. X is a hydrolyzable group, such as chlorine, methoxyl, ethoxyl, acetoxyl, etc., which is easily hydrolyzed into silanol and can be combined with inorganic substances by reaction. Y is an organic functional group, such as vinyl group, amino group, epoxy group, methyl acryloxy group, sulfhydryl group, etc., which can react with organic substances and combine. The properties of typical silane coupling agent are as follows: used for surface treatment of glass fiber and inorganic filler. Used as sealants, adhesives and thickening agents for coatings. It is also used to attach immobilized enzymes to glass