| 摘要 |
<p>Disclosed is a method of making a composite pigment of precipitated calcium carbonate (PCC) and a silicon compound. The PCC/silicate composite pigment made according to this invention imparts increased bulk, light scattering power, porosity and printing properties to paper and is also very cost competitive. The method includes the steps of: introducing carbon dioxide into lime milk comprising calcium hydroxide suspended in an aqueous medium, to effectively precipitate calcium carbonate; introducing a soluble silicate compound into the aqueous medium when the calcium carbonate precipitation reaction has progressed to within approximately 90 % to 100 % of completion; and introducing carbon dioxide into the aqueous medium containing said soluble silicate compound and precipitated calcium carbonate for a period of time effective to precipitate an insoluble silicon compound onto said precipitated calcium carbonate to provide a composite pigment, wherein the aqueous reaction medium has a maximum temperature variation during the silicate precipitation period of less than 20 °C during said period of time.</p> |
