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AssigneeCompanhia Val Do Rio Doce
InventorsMaria Cristina Almeida Valadares, João Duarte Neto
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A high performance kaolin pigment, a paper coating color containing high performance kaolin pigment, and a method for making high performance kaolin pigment, the kaolin pigment being provided with improved optical and rheological properties attained by strict control of size and shape of the particles, as well as size and shape distribution of the particles. The kaolin pigment has ISO brightness characteristics higher than 88.5, a particle size distribution of at least 94% by mass lower than 2 μm and at most 25% by mass lower than 0.2 μm and a Hercules viscosity at 1,100 RPM lower than 18 dynes in slurries with a solid content of 70%-75% solids.
A high performance kaolin pigment characterized by having improved optical and rheological properties, comprising a mixture of crude coarse kaolin and crude fine kaolin having distinct well-defined shape and particle size characteristics, said crude coarse kaolin being composed of large single plate-shaped particles with a high crystallization degree, with a Hinckley index higher than 0.6, with a size distribution in the degritted fraction of 55% to 75% by mass lower than 2 μm, and at most 15% by mass lower than 0.2 μm.
A paper coating color containing high performance kaolin pigment, characterized by having an ISO brightness higher than 88.5 and lower than 91.0;
A method for making high performance kaolin pigment having improved optical and rheological properties attained by mixing coarse kaolin with fine kaolin, characterized in that the processing of fine kaolin comprises the steps of:
Dependencies are inferred from the claim text.