Лако-красочные материалы — производство

Since its discovery more than 30 years ago, the DPP chromophore has been studied intensively by the scientific community and a lot of (potential) application areas for DPPs have been reported for both its pigment forms as well as for soluble derivatives.

One of the major nonclassical commercial applications for DPP pigments is surely in red color filters for LCD screens. The starting point in this development was the paradigm change in the early 90s to switch from dyestuffs to pigments in the color filter production for computer LCD screens. Initially, a C. I. Pigment Red 177 type has been used for red pixels but since the end of the 20th century it has more and more been replaced by highly transparent versions of the more saturat­ed and less bluish DPP pigment C. I. P. R. 254. This pigment has now become an industry standard in this field comparable to the use of phthalocyanine blues and greens for the other two color filters in RGB displays.

DPP pigments have also been claimed for use in cosmetics applications [113,114].

With the latent DPP pigment technology an interesting concept has been devel­oped combining the advantages of dyes, i. e., their ease of application, with the su­perior fastness properties of pigments [115]. This concept makes use of the alky — loxycarbonyl moiety to protect the NH groups of 2 leading to a drastically increase in solubility. In this form, the DPP derivative 30 can easily be applied to a poly­meric material without the usual high input of energy needed to properly disperse a pigment. Finally, due to their high reactivity toward heat and/or acid the protect­ing groups can be removed and the pigment regenerated (Scheme 11.12).

Beyond pigment chemistry, numerous application fields for DPPs have been proposed. Some of them are summarized in Table 11.4. Since a detailed discus­sion would be outside the scope of this chapter, the reader is referred to the given primary literature.