C.I.Direct Yellow 27
C.I.13950
CAS:10190-68-8

Synonymous names:Direct Fast Brilliant Yellow 5GL (HEB);Direct Fast Light Yellow 5G (STIE);Direct Fast Yellow 5G (NIEC);Dycosdirect Fast Brilliant Yellow 5GL (SHC);Fast Light Yellow 5GL (SLIE);Intraline Yellow 7GL (CKC);Levacell Fast Yellow 5G (DYS);Sirius Supra Yellow 5G (DYS);Solar
Flavine 5G (CLAR);Tertrodirect Light Yellow 8G (CKC)

Physicochemical Properties: Light yellow powder. Soluble in water, producing a lemon-yellow solution with solubilities of 30 g/L (60°C) and 50 g/L (97°C). Slightly soluble in cellosolve and sparingly soluble in ethanol. In benzene or carbon tetrachloride, it appears orange and is insoluble in other organic solvents. In concentrated sulfuric acid, it turns golden yellow, lightening upon dilution; in concentrated nitric acid, it forms a bright yellow solution; in concentrated hydrochloric acid, it produces a golden-yellow precipitate; and in concentrated sodium hydroxide, it yields a golden-yellow precipitate. It is slightly sensitive to hard water. In dye baths, copper ions cause minimal color change, while iron ions induce a slight shift (4–5 grade).

Applications: Used for dyeing cotton or viscose to a bright yellow shade, offering good leveling and migration properties. It provides some coverage for uneven-quality viscose. The dye uptake is moderate. It is often blended with Direct Fast Turquoise Blue GL to produce Direct Fast Fruit Green. Suitable for direct printing, with urea recommended for deep shades. To improve wash fastness, it is typically treated with Fixing Agent Y, though this may reduce light fastness. It is also applicable to silk, wool, nylon, and blended fabrics, as well as leather and paper dyeing.