| 摘要 |
P-18015/A/MA 1993 Process for the Production of Pigments of the disclosure A Process for the production of a pigment composition comprising precipitating a pigment coupling component from alkaline solution by adding to it an acid, in the presence of a pre-formed, water-soluble azo dyestuff; and subsequently coupling the precipitated coupling component, containing the azo dyestuff, with a pigment diazo or tetrazocomponent, ensuring that at no time is any substantial amount of uncoupled diazo or tetrazo component present, to form a pigment composition containing the water-soluble azo dyestuff.
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