Direct dye

Description

A large class of water-soluble dyes that quickly adhere to fibers without the aid of a mordant. Natural direct dyes include Henna, Annatto, Saffron, Turmeric, and Archil. Synthetic direct dyes, or substantive dyes, were first derived from Aniline in 1884. In general, they give bright full colors when applied directly onto fiber in a neutral or slightly alkaline aqueous bath containing Sodium chloride or other salts. Often direct dyes are applied to Cotton or Linen, but some work well with Leather, rayon, Silk, or Wool. Because direct dyes generally possess poor colorfastness, some after-treatments, such as diazotization development, are used to improve washfastness. These after-treatments, however, produce new chromophoric groups that change the base color of the dye. For more information on developers see Naphthol, Phenylenediamine, Phenol, Phenylmethylpyrazolone, or Resorcinol.

Synonyms and Related Terms

substantive dye; direct dyes (pl.); colorante directo (Esp.)

Resources and Citations

• Judith H. Hofenk de Graaff, The Colourful Past: Origins, Chemistry, and Identification of Natural Dyestuffs, Archetype, London, 2004

• Hoechst Celanese Corporation, Dictionary of Fiber & Textile Technology (older version called Man-made Fiber and Textile Dictionary, 1965), Hoechst Celanese Corporation, Charlotte NC, 1990

• Rosalie Rosso King, Textile Identification, Conservation, and Preservation, Noyes Publications, Park Ridge, NJ, 1985

• Matt Roberts, Don Etherington, Bookbinding and the Conservation of Books: a Dictionary of Descriptive Terminology, U.S. Government Printing Office, Washington DC, 1982

• Thomas B. Brill, Light Its Interaction with Art and Antiquities, Plenum Press, New York City, 1980

• G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 284

• Van Nostrand's Scientific Encyclopedia, Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976