Inorganic particles and methods of making
AssigneeMillennium Inorganic Chemicals, Inc.
InventorsFu-Chu Wen, Duen-Wu Hua, Deborah E. Busch
Life of this patent
Estimating the term…
Abstract
The present invention provides methods and compositions comprising inorganic solids for use as pigments in paints, papers and plastics.
Claims17
A method of making substantially spherical calcium carbonate particles comprising adding a surfactant to a source of calcium carbonate to obtain substantially spherical calcium carbonate particles having a particle size range between about 0.1 and about 1 micron.
A method of making substantially spherical calcium carbonate particles comprising adding carbon dioxide to a mixture comprising lime, water, and a surfactant to obtain substantially spherical calcium carbonate particles having a particle size range between about 0.1 and about 1 micron.
A method of preparing titanium dioxide pigment particles comprising the steps of:
- a) preparing an aqueous slurry of base titanium dioxide particles;
- b) adding a surfactant and a source of calcium carbonate to the slurry;
- and
- c) precipitating calcium carbonate on the base titanium dioxide particles under conditions so as to form substantially spherical shaped calcium carbonate particles having a particle size range between about 0.1 and about 1 micron on the base titanium dioxide particles, wherein the base titanium dioxide particles have a particle size range between about 0.1 and about 0.5 microns.
A paint, plastic or paper comprising a pigment made by the steps of:
- a) preparing an aqueous slurry of base titanium dioxide particles;
- b) adding a surfactant and a source of calcium carbonate to the slurry;
- and
- c) precipitating calcium carbonate on the base titanium dioxide particles under conditions so as to form substantially spherical shaped calcium carbonate particles having a particle size range between about 0.1 and about 1 micron on the base titanium dioxide particles, wherein the base titanium dioxide particles have a particle size range between about 0.1 and about 0.5 microns.
Dependencies are inferred from the claim text.