Abstract

Phthalocyanines, a class of organic dyes, were discovered in 1907 and today are the main organic blue and green pigments in the industry. Phthalocyanines form complexes with a variety of chemical elements. The most important phthalocyanine, copper phthalocyanine, is produced worldwide. Synthesis usually starts with phthalodinitrile and metal or phthalic anhydride, urea, and metal salts as the starting materials. The reactions can be carried out in a solvent or at higher temperatures in a dry state. The chemical stability and physical properties have stimulated applications of phthalocyanines in fields like semiconductors, catalysts, lasers, and lubricants. However, 90% of the phthalocyanines are used as pigments for printing inks, paints, coatings, plastics, textile, and spin dyeing industries. Phthalocyanine dyes are predominantly used for dyeing of textiles, paper, and leather. The predominant phthalocyanine derivatives are formed with halogens (green pigments), sulfonic acids, and sulfonyl chlorides (dyes).