Functional or ‘High Technology’ Dyes. and Pigments

The chemistry of the most important dyes and pigments used in the coloration of traditional substrates, including textiles, paints, printing inks and plastics, has been dealt with extensively in the previous chapters of this book. It is likely that this range of well-established products will remain for the foreseeable future as the most important materials manu­factured for the purpose of providing colour. In recent decades, there is no doubt that new products for such conventional applications have ap­peared with reduced frequency as industry has concentrated research effort on process and product improvement, and addressing a range of environmental issues (Chapter 11). However, in the same period, there have been exciting developments in organic colour chemistry as a result of the opportunities presented by the emergence of a range of novel applications which place significantly different demands on dyes and pigments. These colorants have commonly been termed functional, be­cause the applications in question often require the dyes or pigments to perform certain functions beyond the simple provision of colour. Alterna­tively, they may be referred to as high technology colorants, because they are designed for use in applications derived from advances in fields to which this particular term commonly refers. The applications of func­tional dyes and pigments include a wide range of electronic applications, including liquid crystal displays, microfilters, solar energy conversion, lasers and optical data storage, some of the more recently developed reprographic techniques, such as electrophotography and ink-jet print­ing, and a range of biomedical uses. While these colorants are unlikely to rival the traditional dyes and pigments in terms of the quantities required, they are potentially attractive to manufacturers due to the possibility of high added value. In this chapter, an overview of the principles of some of

the more important of these applications is presented, necessarily selec­tive in approach because of the diversity of the topics, together with a discussion in each selected case of the chemistry of the colorants which may be used. For some of these applications, traditional dyes and pig­ments may be used, although often the colorants may require special purification procedures, not a common requirement for conventional applications. For others, new colorants tailored to the needs of the particular application have been designed and synthesised.

Вы можете оставить комментарий, или ссылку на Ваш сайт.

Оставить комментарий