The Study Of Surface Modification Of Aluminum Pigment

Aluminum pigment is widely used in anticorrosive coatings,industrial coatings,automotive coatings,plastics,printing inks and other industries due to its excellent hiding,shielding,angular hetero-chromatism and optical properties.With the development of the society,the demand for aluminum pigment is getting bigger and bigger.Meanwhile,there were new requirements for aluminum pigment.Global environmental problems are increasingly serious,public awareness of environmental protection is generally increased,the traditional organic solvent-based aluminum pigment was eventually replaced by water-based aluminum pigment.Aluminum pigment is silver-white,single color,which can not meet people's pursuit of higher decorative and visuality,so it promoted the development of colored and high flash aluminum powder.Here,by taking flake aluminum pigment as the research object,a layer of SiO2 film was coated on the surface of aluminum particles by sol-gel method,which improved the corrosion resistance of aluminum pigment and its dispersion in water system.Then,a layer of nanometer ?-Fe2O3 was coated on its surface by solvent thermal method,which changed the color of the aluminum pigment and prepared the colored pigment.With tetraethoxysilane(TEOS)and silane coupling agent KH-550 as the silicon source,a dense and uniform SiO2 film was coated on the surface of aluminum particles by the synergistic hydrolysis of TEOS and silane coupling agent KH-550 by sol-gel method.The effects of nTEOS/nKH-550,the amount of water added and the droplet acceleration rate of reactants on the experimental results were also investigated.The corrosion resistance,dispersion in water,surface morphology and other properties of the prepared sample were characterized.The results showed that the amount of added water was 3.3g as nTEOS/nKH-550=1:1,and the droplet acceleration rate of the reactant was 1.0mL/min,the surface of the aluminum pigment was completely covered by the nano-particle layer.At this time.the roughness of the surface of the aluminum particles was the smallest,the amount of hydrogen released in the hydrochloric acid solution with pH=2 was the least,and the dispersion was better than that of the original aluminum particles.Using SiO2-coated aluminum particles as the raw material,using iron acetylacetonate(Fe(acac)3)as the iron source and n-butanol as the solvent for solvothermal reaction,the surface of the aluminum particles was coated with a layer of ?-Fe2O3 film,thus changing the color of the aluminum pigment and producing colored pigment.The effects of the amount of water and Fe(acac)3,the reaction temperature and time on the experimental results were further investigated.The color difference,light reflectivity,crystal phase and surface morphology of the as-prepared samples were characterized.The results show that when the amount of water was 0.644g,the crystal phase of the nanoparticles generated on the surface of the aluminum particles was ?-Fe2O3.The hue of aluminum pigment varies with the amount of Fe(acac)3.To make the coating effect of aluminum powder better,the reaction temperature should be lowered and the reaction time should be prolonged.