Steamrollers, sports cars and security: Phthalocyanine progress through the ages

Serendipity has been a major player in most dye discoveries, and phthalocya nines are no exception. The true account of their discovery in 1928 is give n using information provided by one of the individuals involved (Ron Greig) . One of the inventors, Drescher, after making a key observation as to the nature of the insoluble blue impurity formed in the routine manufacture of phthalimide from phthalic anhydride, was killed weeks later when, on his be loved Sunbeam motorcycle, he had a head-on collision with a steamroller on his way to work. The unique properties of phthalocyanine dyes and pigments make them the colorant of choice for most blue and green colours. Thus most blue and green cars, including sports cars, are coloured by phthalocyanine pigments. In addition to these traditional uses, phthalocyanines are also finding extensive use in modern hi-tech areas. They are used for their colo ur as, for example, cyan dyes in ink jet printing, and in colourless applic ations such as infrared absorbers in security. The discovery, traditional a nd hi-tech applications of phthalocyanines are described in detail in this paper. Copyright (C) 1999 John Wiley & Sons, Ltd.