Solvent dyes

  Solvent dyes  cannot be classified according to a specific chemical type of dyes. Solvent dyes can be found among the azo, disperse, anthraquinone, metal-complex,  cationic,  and  phthalocyanine  dyes.  The  only  common  characteristic  is  a chemical structure devoid of sulfonic and carboxylic groups, except for cationic dyes as salts with an organic base as anion. Solvent dyes are basically insoluble in water, but soluble in the different types of solvents. Organic dye salts represent an important type of solvent dyes.

  Solvent dyes also function as dyes for certain polymers, such as polyacrylonitrile, polystyrene, polymethacrylates,  and  polyester, in which they are soluble. Polyester dyes are principally disperse dyes .For practical reasons the different solubility can be used as a basis for a classification of solvent dyes, although there is no strict differentiation. Chemical constitution is defined here as a structure which meets the corresponding solvent requirements.