| 摘要 |
<p>In a process for conditioning an azo pigment by alkaline reprecipitation, the crude pigment, in a polar organic solvent, is converted to a pigment salt by adding a base, the azo pigment is reprecipitated by adding an acid and the acidic pigment suspension is then heated, with stirring, and the crystalline pigment obtained is isolated. The process results in crystals of improved form, improved texture and more advantageous rheological properties The conditioned azo pigments are particularly suitable for colouring high-molecular organic material.</p> |
