| 摘要 |
<p>A process is disclosed for the direct preparation of pigmentary 1,4-diketopyrrolo-Ä3,4cÜpyrroles of the formula (I) <CHEM> wherein each of R1 and R2 independently of the other is an isocyclic or heterocyclic aromatic radical, which process comprises heating an appropriate molar ratio of a disuccinate with a nitrile of the formula (II) R1-CN or of the formula (III) R2-CN or with mixtures of said nitriles, in an organic solvent and in the presence of a strong base and an effective amount of a selected particle growth inhibitor of formula (IV)-(X), and then obtaining the compound of formula (I) from the reaction product by protolysis. The process yields pigmentary 1,4-diketopyrrolo-Ä3,4-cÜpyrroles directly, i.e., without the need for additional particle-size reducing aftertreatments. Also disclosed is a composition comprising a pigmentary 1,4-diketopyrrolo-Ä3,4-cÜpyrrole and the particle growth inhibitor. These pigment compositions are useful for pigmenting high molecular weight organic materials.</p> |
