Indanthrene dyed
Also known as: Vat dyed, Indanthrene
Vat dyeing with indanthrene dyes; achieves highest wash and light fastness for long-lasting fabrics.
Description
Indanthrene-dyed textiles are coloured with dyes from the indanthrene or anthraquinone vat dye class. These dyes are water-insoluble; they are reduced to their soluble leuco form with a reducing agent (sodium dithionite), taken up by the fibre in that form and then oxidised back in air. The dye then sits as an insoluble pigment inside the fibre and is practically unwashable.
Wash, rub, light and chemical fastness of indanthrene dyeings is exceptionally high: grade 4-5 in virtually all test standards, even after 50 washes at 60 degrees. The Indanthren trademark was introduced by BASF in 1901 and stood for decades for top quality in workwear, church textiles and marine uniforms.
Downsides: complex, expensive process with reduction and oxidation steps, high chemical use (sodium dithionite and caustic soda burden wastewater). The process is today used only for premium workshop clothing, high-end shirts and historic uniforms. In industrial mass cotton dyeing reactive dyeing is ecologically more favourable.
Properties
| Process | Vat dyeing via redox process |
|---|---|
| Result | Extreme colour stability, deep shade |
| Colour fastness | Top class (wash/light 4-5) |
Related product categories
Sources & references
2- Wikipedia: Indanthren Wikipedia — Freie Enzyklopädie https://de.wikipedia.org/wiki/Indanthren
- BASF Historisches Archiv basf.com https://www.basf.com/global/en/who-we-are/history.html
