High dioxazine pigments

To obtain the necessary fastness properties, high-quality pigments are generally used for security printing. The range of suitable products covers disazo, disazo condensation, benzimidazolone, naphthol AS, isoindolin, perinone, anthanthrone, dioxazine and quinacridone pigments. 

Like most high-performance pigments, benzimidazolone-dioxazines are expected to be more highly priced than classical pigments. However, their outstanding tinctorial strength should reflect their overall value within reasonable limits, in line with the following ... 

Benzimidazolone-dioxazine pigments identified for commercialization thus far are red-violet to reddish-blue in shade. They are characterized by an exceptionally high tinting strength, and their heat stability and resistance to aggressive solvents and plasticizers is much superior to that of carbazole dioxazine pigments. 

Test results conducted thus far suggest that benzimidazolone-dioxazine pigments should be suitable for almost all applications for the highest performance requirements expected of a high-performance organic pigment. 

Imidazolone-annellated triphenedioxazine pigments, also called benzimidazo-lone-dioxazine pigments, are a relatively new class of violet pigments with very good fastness properties and extremely high color strengths. The stractural formula is shown in Figure 20.1. 

Other chemical types of high-performance organic pigments are exemplified by the tetrachloroisoindolinone 222 (C. I. Pigment Yellow 110) and the dioxazine 223 (Carbazole Violet, C. I. Pigment Violet 23). Considerable research has been carried out in an attempt to exploit the potential of metal complex chemistry to provide high-performance pig-... 

The three-dimensional crystal structure of Pigment Violet 23 (117) elucidates molecular staples whereby the stables of the single molecular planes are arranged in an almost perpendicular orientation to each other. Interactions of the -ir-orbitals as well as van der Waals forces are responsible for the cohesion of the structure. The degree of overlapping is especially high in the dioxazine part of the molecule [3],... 

Carbazole dioxazine violets are semitransparent masstone pigments having high tint... 

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