Composite pigments comprising in-situ precipitated metal carbonate crystals
AssigneeEngelhard Corporation
InventorsS. A. Ravishankar, Ernest M. Finch, Richard R. Berube
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Abstract
Composite pigments comprising particles of silicate or oxide minerals having deposited thereon a multiplicity of particles of a metal carbonate as a result of in-situ precipitation.
Claims13
A composite pigment consisting essentially of particles of an oxide or silicate mineral as a substrate and precipitated directly on the surface of said particles and chemically bonded to said surface a multiplicity of positively charged crystals of polyvalent metal carbonate.
A composite pigment consisting essentially of platy particles having an average size in the range of 0.3 to 2.0 μm of hydrous kaolin clay and precipitated directly on the surface thereof and chemically bonded thereto from 5 to 55% based on the total weight of said composite pigment of crystalline calcium carbonate, magnesium carbonate or a mixture of calcium and magnesium carbonate.
Dependencies are inferred from the claim text.