Лако-красочные материалы — производство

The Michael reaction requires the use of a highly basic catalyst for the reaction to occur at room temperature. Initial research utilised strong inorganic bases to catalyse this reaction. However, due to the retention of these bases in the final film, very poor water resistance characteristics were observed. Recently, these catalysts have been replaced by organic bases, such as diazobicyclo undecene (DBU), diazobicyclo nonane (DBN) or tetramethyl guanidine (TMG). Although these catalysts are also retained in the film, proper formulation of catalyst type and level can minimise the effect on water resistance. Due to the dependence of this reaction on a highly basic catalyst, the reaction is extremely sensitive to the presence of acid, which will completely block the reaction. In the presence of acidic media, deprotonation of the acid will occur preferentially and no cure of the coating will take place.