Silicone additive used as adhesion promoter
Silane adhesion promoters have been widely used in glass, ceramic, zinc, iron and some plastic substrate solvent-based coatings system. Its working principle is shown in Figure 4. As shown in FIG. 4, the alkoxy groups in silane react with a small amount of water in the system to form silicon hydroxyl groups, which react with the hydroxyl groups on the surface of the substrate to form a firm adsorption layer. The R group contained in silane contains reactive groups (for different resin systems have amino group, epoxy group, methyl acryyl group, etc.) can be in the process of crosslinking with the resin system to produce chemical bonding crosslinking, providing a strong bridging effect between the resin and the substrate, thus greatly improving the adhesion. And solvent coating system, same in water-based coating system, when used in glass, ceramics and some of the metal and plastic substrate, silane can still used for adhesion promoter, but with different solvent system, due to the water system with water as dispersion medium, usually applies to the solvent system of silane adhesion promoter to the water system, Because the hydrolysis speed is too fast, it will soon fail, so it can only be added at the construction site when it is used. According to the characteristics of waterborne coating system, silane suitable for waterborne coating system was developed. By adjusting the size of the R group in the silane structure, through the steric resistance effect of THE R group, the hydrolysis rate of silane is affected, so that the hydrolysis cycle of silane can be synchronized with the use cycle of waterborne paint, improve the storage stability of waterborne paint.