Ciba Specialty Chemicals Corporation

Ciba-geigy Corporation

Basf Se Corporation

Albert Riegler

Yves Grandidier

Klaus Ruf

Urs Schlatter

Takashi Deno

Volkhard Wiese

Werner Saar

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.

An improved flush process for the production of a colorant composition, which involves mixing a colorant in the presence of water with the organic carrier material in a kneader at a temperature sufficient to melt said organic carrier material and flushing the colorant onto the organic carrier material with the concomitant formation of a colorant-free separate water phase, wherein the improvement consists essentially of kneading the mixture of molten colorant composition and separate colorant-free water while cooling the kneader and the mixture to a temperature below the softening point of the organic carrier, a temperature sufficient to cause the molten colorant composition to solidify, and concomitantly comminuting the solidified colorant composition into broken, irregular granulates in the presence of the colorant-free water.

Process for the production of colorant preparations and the colorant

Preparations which contain 10 to 70% by weight of a pigment or a polymer-soluble colorant and 90 to 30% by weight of a carrier mixture which is composed of 51 to 95% by weight of a metal salt of an aliphatic carboxylic acid containing at least 12 carbon atoms, said metal selected from the group consisting of calcium, barium, zinc, aluminum, and magnesium, and of 49 to 5% by weight of an elastomeric or thermoplastic polymer are useful for coloring molten thermoplastic polymers in level shades.

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Basel, Switzerland

Albert Riegler