| 摘要 |
Organoclay materials formed by reacting smectite clays with a quaternary ammonium compound are improved by controlling the pH of the reaction mixture, typically to a value in the range 8 to 10, and preferably 9.0+/-0.5, and by including in the reaction mixture a further substance, such as urea or sulphamic acid, having an unsubstituted or substituted amino or amido group. |
