Of Tio <sub> 2 </ Sub> / Ceo <sub> 2 </ Sub> / Mica And Tio <sub> 2 </ Sub> / Al <sub> 2 </ Sub> The O <sub> 3 </ Sub > Pearlescent Pigment

Combined with theory of colloid chemistry, crystalchemistry, surface chemistry, inorganic materials science and technolegy, mica and flaky Al₂O₃ were used respectively as substrate to synthesize pearlescent pigments of TiO₂/CeO₂/mica and TiO₂/ Al₂O₃. The principle of hydrolysis and heat treatment process were used. The double-coated layer of TiO₂/CeO₂/Mica and TiO₂/Al₂O₃ pearlescent pigments with high luster were prepared. These tests of SEM, XRD, DTA-TG, EDAX, and so on, were appplied to determined the structures and performances of pearlescent pigments.To synthesize the pearlecent pigment of TiO₂/CeO₂/mica with high luster, TiCl4 was used as the titanium raw material, NaOH was used as precipitant raw material, and the hydrolysis precipitation method was applied to coat Ti(OH)4 particles on the surface of flaky mica, the suitable process conditions for coating reaction were systematically studied, such as the concentration of cerium oxide-mica suspension, the concentration of NaOH solution, feeding rate, reaction temperature, pH, stirring speed, coating rate, etc. The reasonable conditions for coating reaction were showed that, the concentration of Cerium oxide to mica suspension is 1%⁵%, the concentration of NaOH Solution is 0.5%～1.0%, the feeding speed is 0.5¹.5 ml/min, the temperature is 85℃, the reaction pH is 2.0².5, the stirring speed is 170 r/min, coating ratio for TiO₂ is 10%. The heat treatment condition was analyzed, such as the reasonable calcination temperature is 850℃and the heating rate is 2⁶℃/min.The new pearlecent pigment of TiO₂/CeO₂/mica with higher luster was obtained.To prepare the pearlescent pigment of TiO₂/Al₂O₃ with higher luster, flaky Al₂O₃ was used as substrate material, TiCl4 and NaOH were respectively used as the titanium raw material and precipitant. The precipitate particle of Ti(OH)4 were coated on the surface of flaky Al₂O₃ by hydrolysis mathod. The reasonable coditions for coating reaction and heat teatment concentration were showed as follow. the concentration of Al₂O₃ suspension is 1%³%, the concentration of NaOH Solution is 0.5%～1.0%, the temperature is 70℃, the reaction pH is 2.0, the stirring speed is 300 r/min, coating ratio for TiO₂ is 10%. the calcination temperature is 900℃. And the pearlecent pigment of TiO₂/Al₂O₃ with higher luster was gotten.