Basic dye

Description

A class of water-soluble synthetic dyes containing a cationic functional group, such as an amide. The first basic dye was mauve, discovered in 1856 in England by William Perkin. Basic dyes will attach directly to an acidic site, such as those found in wool, silk, leather, acrylics, and polyesters. These dyes can be used on cotton and paper after the cellulose is mordanted with a tannin. Basic dyes produce bright colors with poor colorfastness; this can be improved by the use of tannin mordants. Despite their poor stability, basic dyes are still used for coloring construction paper, inks, acrylic fibers and some silks because of their bright, clear hues. They are also used as biological stains for cell structures and as antiseptics.

Most basic dyes have one of the following type of structures:

• Azo: Many azo dyes are basic dyes; but basic dyes of the azo type tend to be yellow, orange, red or brown in color.
• Cyanine: Almost all cyanine dyes are basic dyes with a wide range of colors: Basic Yellow 28, Basic Red 46, Quinoline Blue.
• Acridine: Basic dyes are either yellow or orange; Acridine orange, Chrysaniline, Acryflavine, Rheonine, Benzoflavine.
• Diphenylmethane dye: Basic dyes formed from diarylmethane are usually yellow to orange; Auramine O (BY2), Auramine G.
• Triphenylmethane: Basic dyes formed from triarylmethane are usually green to blue to violet; Malachite green (BG4), Methyl Violet (BV1, BV3, BV14), crystal violet (BV3), Fuchsin (BV14), Brilliant Green (BG1), Victoria Blue (BB26).
• Nitrogen-containing heterocyclic compounds: These include oxa-anthracene, oxazine, and thiazine.

Additional examples of basic dyes are methylene blue, safranine, Rhodamine, hematoxylin, thionine, and toluidine blue.

See also Dye types.

Synonyms and Related Terms

colorante básico (Esp.); coloranti basici (It.); corante básico (Port.)

Physical and Chemical Properties

• Soluble in water and alcohols.
• Generally poor lightfastness (except for acrylic fibers where they have very good lightfastness)
• Proteins are usually dyed in weak alkaline solutions.

Resources and Citations

• Alfa Chemistry: Basic Dyes
• G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 284
• 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
• A.Scharff, 'Synthetic dyestuffs for textiles and their fastness to washing', ICOM-CC Preprints Lyon, Getty Conservation Institute, Los Angeles, 1999
• Klaus Hunger, ed., Industrial Dyes: Chemistry, Properties, Applications (in German), Weinheim: WILEY-VCH Verlag, pp. 276ff,2003. ISBN 978-3-662-01950-4.