| 摘要 |
<p>The invention concerns a method for making a pigment composition comprising inorganic base particles and one or more inorganic spacer particles precipitated thereon, including the steps of forming an aqueous slurry of the inorganic base particles, if necessary, milling the aqueous slurry so that at least 50% of the inorganic base particles are less than 0.5 microns, in size, heating the slurry as needed to achieve and maintain a temperature of at least 40 degrees Celsius, adjusting the pH of the slurry as needed to achieve and maintain a pH in the range of from 4 to 9, adding the inorganic spacer particles to the slurry while maintaining such temperature and pH conditions and with intensive mixing, and finally, recovering the pigment composition from the slurry.</p> |
