High benzimidazolone 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. 

The benzimidazolone moiety, a fundamental feature of all benzimidazolone pigments, is responsible for the high fastness of these pigments to the solvents which are typically found in application media. In this respect, benzimidazolone pigments perform much better than their counterparts in the monoazo yellow and... 

Several benzimidazolone pigments are suitable candidates for use in powder coatings based on polyester, acrylic, or polyurethane resin. These pigments satisfy the heat requirements of this application and do not plate out in these media (Sec. 1.6.4.1). Various benzimidazolone pigments even meet the particularly high thermal standards of coil coating. These pigments are also suitable for use in architectural and emulsion paints. 

Benzimidazolone pigments are also used to color polystyrene, ABS, and other polymers which are processed at high temperature. A number of grades show excellent lightfastness and also satisfy the heat requirements for use in unsaturated polyester without affecting the hardening of the polymer. 

Benzimidazolone pigments are actnally monoazo pigments but the convention within the indnstry is to not use the azo descriptor they are classified as high-performance pigments. All the pigments in this class are derived from coupling... 

The properties described qualify benzimidazolone pigments for applications such as high quality industrial paints, including automotive finishes and special effect paints, plastics and high performance printing inks. The colorants are available in the form of powders, masterbatches, liquid dispersions, pastes and granules (see Table 10-4). 

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 ... 

Because of their physicochemical properties benzimidazolone pigments represent an extremely low toxicological and environmental risk. like other azo pigments, the benzimidazolone pigments have very high oral LD o values. Exposure to fine dust should however be avoided in the workplace, and normal industrial hygiene procedures for handling chemicals should be practiced. 

These pigments may be defined as those that will meet the exacting demands of today s environment with respect particularly to the outdoor exposure requirements demanded by climates such as those that occur in Florida and Arizona for as little as two and as long as five years. The high-performance reds considered fall into four basic classes quinacridone reds and violets, vat dyestuff reds such as perylenes, benzimidazolone reds, and disazo condensation reds. 

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. 

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