Basf Se Corporation

Ciba Specialty Chemicals Corporation

Max Hügin

Thomas Eichenberger

Leonhard Feiler

Thomas Raimann

Hans Reichert

Marc Maurer

André Fuchs

Bruno Inderbitzin

Karin Eberius

Ulrich Veith

Sibylle Soder

The present invention relates to a photochromic ink, the process for its preparation which is based on a spiropyran powder obtainable by melting, cooling and crushing, and to a new form of a spiropyran obtainable thereby. Said process to prepare a photochromic ink comprises the steps of a) heating and melting the spiropyran at a temperature below 250 C, b) cooling the melt to obtain a solidified spiropyran, c) crushing the solidified spiropyran to obtain a powder, d) optionally adding the powder to a binder providing the basis for the photochromic ink.

Preparation of a photochromic ink

The present invention is directed to 2-[[1-[[(2,3-dihydro-2-oxo-1H-benzimidazol-5-yl)amino]carbonyl]-2-oxo-propyl]azo]-benzoic acid (C.I. Pigment Yellow 151): (I), characterized by a &#x394;E* (black/white) in masstone below 22.0&#xb1;0.7, a process for its preparation and its use for pigmenting macromolecular organic materials of natural or synthetic origin. The pigment has high opacity and high color strength.

2-[[1-[[(2,3-dihydro-2-oxo-1H-benzimidazol-5-yl)amino]carbonyl]-2-oxopropyl]azo]-benzoic acid and a process for its preparation

The present invention relates to azo dyes of formula (1) which are soluble in organic solvents, wherein Ris &#x2014;CN, &#x2014;COOR, &#x2014;CONRRor a heterocyclic ring, Ris unsubstituted or substituted alkyl, unsubstituted or substituted aryl, &#x2014;CF, &#x2014;COOR, &#x2014;CONRRor &#x2014;COR, Ris hydrogen, &#x2014;SOM, alkyl, alkoxy, alkylcarbonyl, &#x2014;NOor halogen, Ris substituted aryl, substituted heteroaryl or an aryl-N&#x2550;N-aryl radical, wherein one or both of the aryl radicals in aryl-N&#x2550;N-aryl is/are unsubstituted or substituted, or a radical heteroaryl-N&#x2550;N-heteroaryl, wherein one or both of the heteroaryl radicals in heteroaryl-N&#x2550;N-heteroaryl is/are unsubstituted or substituted, Ris hydrogen, alkyl or unsubstituted or substituted aryl, Ris hydrogen, alkyl or unsubstituted or substituted aryl, Ris hydrogen, alkyl or unsubstituted or substituted aryl, Mis a cation, n is a number 1, 2 or 3 and m is a number 1, 2 or 3, to a process for the preparation thereof and to the use thereof in the production of colored plastics or polymeric color particles, and as printing inks, printing dyes, coating compositions and wood stains 

Benzimidazole-pyridone-based azo dyes

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Rünenberg, Switzerland

Max Hügin