Additivity of substituent effects on the visible absorption spectra of some heteroarylazo compounds: the influence of solvent

Colour and colour application science and technology are widely practised throughout the world today. However, there are questions which are still unresolved, and sometimes this is due to the experimental difficulties involved in pursuit of the answers. In the USA and Western Europe, recent years have seen the added commercial problems of excess global dye and chemical capacity, international sourcing, and pricing pressures. The result has been a complete reorganization of those multinational chemical companies with textile colour related divisions, followed by divestments, mergers, acquisitions, downsizing of services and a broad loss of colour and coloration expertise. Technical and commercial problems both have an impact on the future of textile colour application research, and this paper addresses some of these problems.