Pigment particles coated with precipitated calcium carbonate and a process for the preparation thereof
AssigneeFP-Pigments Oy
InventorPentti Virtanen
Life of this patent
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Abstract
This invention relates to a pigment particle product and a method for its preparation. According to the invention pigment particles, such as kaolin, natural calcium carbonate or titanium dioxide, and precipitated calcium carbonate are mixed together in an aqueous phase at pH 6-11, which causes the pigment particles to become coated with particles of precipitated calcium carbonate. The brightness of the product is excellent, and it is quite inexpensive to produce.
Claims10
A pigment particle product, which comprises from 30 to 90% by weight of particles of precipitated calcium carbonate that range in size from 30 to 100 nm and said particles are attached to the surfaces of the pigment particles of said product.
A method for coating particles with precipitated calcium carbonate, wherein an aqueous suspension of pigment carbonate is formed by mixing in a mixer, the pH of said aqueous suspension being adjusted to a value within the range 6-11, and wherein agglomerates of precipitated calcium are first formed before mixing to a particle size in the range of 30-400 nm, and thereafter these agglomerates are disintegrated to calcium carbonate particles of 30-100 nm particle size, whereby the resultant particles of calcium carbonate are attached to the surfaces of the pigment particles.
Dependencies are inferred from the claim text.