| 摘要 |
<p>A pigment comprising particles of uncalcined kaolin clay combined in the absence of a binder with an amount of an added source of zirconium ion, such as ammonium zirconium carbonate, at least sufficient to enhance optical character of a dried composition containing the pigment. In application, the pigment may be utilized in a coating for paper or other fibrous web substrate to produce sheet materials of enhanced opacity. Alternatively, the pigment may be employed as a filler in a fibrous web substrate to provide improved optical character of the material. Also disclosed is a method preparing a pigment, including preparing a dispersed slurry of clay particles in an aqueous medium, wherein the improvement comprises utilizing an uncalcined kaolin clay and introducing into the slurry in the absence of a binder the source of zirconium ion in an amount at least sufficient to enhance the optical character afforded by the pigment.</p> |
