The pigment exhibits a unique blue shade violet color of exceptional intensity. It is employed in virtually all applications including inks, plastics, coatings, textiles and other special purpose media such as contact lenses. The printing ink industry is the largest consumer of this pigment. Most grades possess high specific surface areas, some in the region of 100 m2/g. Therefore, to achieve good dispersion and to avoid flocculation, it is necessary to maintain an adequate pigment to binder ratio, which in this case is higher than that for most other organic pigments.
The high tinctorial strength of Pigment Violet 23 ensures that it is an excellent shading pigment. For example, as a shading component for paints it provides a reddish tinge to the shade of copper phthalocyanine blue pigments. As it is light — fast and weatherfast, even in very light shades, and fast to overcoating, it is used in architectural, general and high grade industrial finishes including metallic ones. However, as a result of the more stringent requirements (external durability) now demanded by the automobile industry its use in automotive paints has greatly diminished.
Widely employed in the coloration of plastics, Pigment Violet 23 generally exhibits very good properties in terms of heat stability and lightfastness provided its concentration in the polymer is not too low (the fastness properties tend to dimin-
ish as the amount of white pigment increases). Although not entirely migration resistant, in plasticized PVC it still exhibits excellent weatherfastness and is suitable for long term exposure in that medium.
12.3.2