摘要 |
New silicoaluminate-based pigments characterised in that they have a surface chemistry such that their number of cationic sites, expressed in micromoles/m<2> of surface, is greater than 0.05. They are prepared by a process consisting in treating a silicoaluminate suspension exhibiting a pH of not more than 8 with an organic or inorganic salt of an at least divalent metal, then in raising the pH of the mixture again to a value higher than or equal to 3.5, in separating the treated silicoaluminate from the said mixture, and then in drying the recovered silicoaluminate. The invention also relates to the use of the said pigments as fillers for paper. |