Abstract
Novel cationic catalysts have been found. The catalysts consist of aluminum complexes and active silicon compounds. The active species are Br Onsted acids formed by interactions between aluminum complexes and silanols. The latent catalysts which can be activated with heat or lights have been provided by employing silicon compounds which are decomposed thermally, or photochemically to form silanols. These catalysts have been applied to cure epoxy resins. The epoxy resins cured by these catalysts have been characterized by excellent electrically insulating properties. This is because the catalysts does not generate ionic impurities which cause decrease in electrical insulation properties. It was also found that this catalyst was effective for accelerating reactions between epoxy resins snd aromatic amines, and between maleimides and aromatic amines.
