DRAGA DRAGNEA, DRAGOS GUDOVAN, ELENA ZAHARIA, COSTIN SORIN BILDEA THE TREATMENT OF ALUMINIUM PIGMENTS WITH INORGANIC POLYMERS FOR ENVIRONMENT-FRIENDLY APPLICATIONS Aluminium pigments are used in industrial and decorative coatings, automotive industry and printing inks. The encapsulation of aluminium pigments is used because the industry wants to avoid the organic solvents, for environmental reasons, by shifting towards water-borne systems. However, aluminium pigments easily react with water and a large amount of hydrogen is released leading to degradation of optical properties. This work presents experimental results concerning the encapsulation of aluminium pigments in silica matrices, by a sol-gel method using TEOS as precursor and ethylendiamine or ammonia as catalysts for the hydrolysis and condensation reactions. The samples of encapsulated pigments were characterized by gas stability tests: a boiling method and a gassing method.
Keywords: aluminium pigments, coatings, encapsulation, sol-gel process