| abstract |
Process for the production of a pearlescent pigment, comprising the steps of: activating the surfaces of squamous alumina substrate particles produced by a hydrothermal process by at least one method selected from plasma treatment, ultrasonic treatment, acid treatment, treatment with alkali, shock treatment or chemical etching treatment, dispersing in water the squamous alumina substrate particles obtained in the previous stage; hydrolyze in the resulting dispersion a metal salt comprising at least one titanium salt, allow the metal hydroxide or the resulting metal oxide to deposit on said surfaces of said squamous alumina substrate particles, and then subject the resulting tank to heat treatment to form, on said surfaces of said flaky alumina substrate particles, metal oxide coating layers having a particle size in a range of 1 to 500 nm. |