| abstract |
The present invention relates to a process for the direct preparation of pyrrolo[3,4-c]pyrroles (DPPs) of the formula pigment compositions containing them and their use for coloring high molecular weight organic materials, such as plastics and paints. The obtained DPPs of the formula I possess a higher color strength, a higher chroma, a purer shade and a higher opacity versus corresponding commercially available DPPs. |