BiOCl pigment
AssigneeEngelhard Corporation
InventorsPaul B. Cao, Michael Venturini
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Abstract
A bismuth oxychloride effect pigment has a zinc oxide or microfine titanium dioxide particulate at about the surface of the crystals of the bismuth oxychloride. The pigment is prepared by, for instance, growing the bismuth oxychloride crystals, and adding the particulate before the hydrolysis is complete.
Claims25
An effect pigment which comprises bismuth oxychloride crystals having a particulate embedded at about the surface thereof, wherein the particulate is microfine zinc oxide or titanium dioxide.
A method of producing a bismuth oxychloride pigment which comprises combining a soluble bismuth salt and chloride ions in an aqueous medium under hydrolyzing conditions to form an aqueous dispersion of bismuth oxychloride crystals, and when about 80 to 95% of crystals formation is complete, adding a particulate to the aqueous medium, wherein the particulate is microfine zinc oxide or titanium dioxide.
A method of producing a bismuth oxychloride pigment which comprises combining a soluble bismuth salt and chloride ions in an aqueous medium under hydrolyzing conditions to form an aqueous dispersion of bismuth oxychloride crystals, adding a microfine zinc oxide or titanium dioxide particulate to the aqueous dispersion, combining a salt of aluminum or a rare earth metal with the particulate-containing dispersion, and raising the pH.
Dependencies are inferred from the claim text.