Slovenia - Dying

2. Dye
Substance used to
import colour to
various materials
Organic compounds
(carbon)
Pigment
Finely ground solids
dispersed in a liquid or
blended with other
materials
Inorganic or organic
compounds
Give brighter colours
 Synthetic dyes can be harmful:
mercury, lead, chromium,
copper, sodium, chloride, toulene,
benzene
 Differnet things used to dye
fabric:
boiled shellfish, plants, mud… Natural dyes:
Plant-based, insects
Fade faster

3. DIRECT COLORING
 Direct dye = substantive dye
 water soluble compounds
 benzidine derivatives
 cheap, easily applied, bright colours
 positively and negatively charged groups
 Methyl orange
 Congo red:
 belongs to a group of azo dyes derived from benzidine
 synthetic dye
 mordant – a substance used to fix the colour to cotton fibers
 histology, acid-based indicator

4. COLORING AS A RESULT OF A
CHEMICAL REACTION
 Azo dye is a synthetic organic dye, containing
nitrogen as the azo group (-N=N-)
 Several categories, defined by fibers or methods
of application
aromatic amino
compounds
diazotization
Attachment of
an intermediate
to a phenol or
aniline

5. Indigo dye
 Organic compound
 Extracted from the leaves of Indigofera and Isatis
 Indican
 Simpler compounds:
 reduction to the soluble yellow leucoindigo
 reoxidized to indigo

6. DISPERSE DYES
 Water-insoluble dyes
 Dye polyester and acetate fibers
 The smallest molecules
 Based on an azobenzene or anthraquinone molecule
 High temperatures
+ nitro, amine, hydroxyl… groups
attached