Kaolin slurry, its preparation, and dispersant therefor.

摘要

A heat stabilized slurry of bulked kaolin pigment is prepared by mixing a small but effective amount of a water-soluble cationic material such as a cationic polyelectrolyte flocculant with a kaolin clay pigment in the presence of water. The resultant bulked clay product is dispersed to form a high solids clay-water slurry useful in making aqueous coating colors suitable for manufacturing lightweight coated publication papers or the pigment can be used as a filler for paper webs. Slurries having stable viscosity during storage at elevated temperature and improved resistance to the formation of sediment are prepared by using as the dispersant a combination of an anionic lignosulfonate and an anionic naphthalene sulfonate formaldehyde complex in combination with a polyacrylate salt.