Soluble dyes fastness properties

A series of water-soluble fiber-reactive xanthene dyes has been prepared from the reaction of ben2oxanthenedicatboxylic acid anhydride disulfonic acid with, for example, 3-aminophenyl-P-hydtoxyethyl sulfone to yield dyes, with high brilliance and good fastness properties for dyeing of or printing on leather, wool, sHk, or ceUulosic fibers (53). 

Aftertreatments include resin finishes, which improve fastness properties, and dye-fixing agents of the epichlorhydrin—organic amine type. These agents react with the dye to give condensation products that are not water soluble and hence more difficult to remove. 

A vat dye is a water-insoluble colorant containing two or more keto groups. It can thus be brought into aqueous solution by a reduction process (vatting), which converts the vat dye into its alkali-soluble enolic (leuco) form. As the soluble sodium enolate the leuco vat dye has substantivity for cellulose. The application of vat dyes to cellulosic fibres (virtually the only fibre type on which their outstanding fastness properties can be exploited) thus proceeds in four stages ... 

Iron(II) complexes of 7-nitroso-6-hydroxyindazoIes (203) are sufficiently soluble in water to permit the dyeing of wool and polyamide fibres in green to olive shades having good fastness properties from weakly addic dyebaths. Cationic iron(H) complexes (204) have also been prepared from quatemized indazoles of this type but have found little or no commercial application. 

Ink-Jet Dyes for Special Media. Anionic water-soluble dyes (19) are the dyes of choice for ink-jet printers. The properties required of these ink-jet dyes include high color strength, good stability in the appropriate solvent, good fastness properties (especially to light and water), and high purity. Obviously, the dyes must... 

Dyes of this class are designed to be soluble in organic solvents such as alcohols, ketones, and hydrocarbons and, hence, are insoluble in water. They are of relatively low molecular weight and have a considerable range of fastness properties. In general, they are not suited for detergent applications. An example of a solvent dye is shown in scheme 6. 

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