Ciba Specialty Chemicals Corporation

Basf Se Corporation

Urs Schlatter

Yves Grandidier

Albert Riegler

Klaus Ruf

Takashi Deno

Substantially crystalline organic pigments characterized by small particle size and narrow particle size distribution.

Pigments having improved coloristic properties and process for their preparation

This invention relates to 1,4-diketopyrrolo[3,4c]-pyrrole pigments of the formulacharacterized by desirable color properties and novel visible absorbance spectra with a steep slope on the bathochromic side of the absorption maximum in the range of from 500 to 650 nm.

The invention relates to a process for preparing pigments, which comprises These pigments and their use in polymers, printing inks and colours filters are also claimed. The invention in particular relates to a novel pigment form of Pigment Violet 23obtained by above-mentioned process and having higher colour strength and colour saturation as well as excellent other applications properties in particular in printing inks. The invention also relates to a highly crystalline novel form of Pigment Red 254obtained by above-mentioned process, too, and having a steep slope on the bathochromic side of the absorption spectrum's maximum, and the use thereof in particular in colour filters.

Growing community of inventors

Pratteln, Switzerland

Urs Schlatter