Adhesion in the coatings industry part 5.2: Adhesion promoters

摘要

In general terms, the organofunctional silanes, as discussed earlier, are characterised by the general formula of X-R-Si-(OR')3, where X is an organofunctional group, R is a spacer which can be either an aryl or alkyl chain (typically an alkyl chain where it is characterised by -(CH2)n, and n= 0,1 2 or 3), and OR1, in this example, is a hydrolysable group, typically alkoxy, acyloxy, halogen or amine. X as an organofunctional group is characterised by organoreactive groups such as amino-, aminoethyl-, vinyl-, methacryloxy-, glycidoxy - (i.e. epoxy functional) etc. If we take as the most frequently encountered situation where for R we have the spacer -(CH2)_n, and we look at the reaction of the organofunctional silane with water, it initially undergoes hydrolysis with water to produce an organosilanol with a simple by-product splitting off, as shown in the following equation.