Naphthol as-Ol Azoic Coupling Component 20 Naphthol Dye for Textile

Naphthol AS-OL (C.I. 37530 / Azoic Coupling Component 20) is known for its excellent solubility in caustic soda solution, which is superior to AS-RL and AS-BO. It offers versatile shade possibilities---producing orange, red, maroon, or blue shades depending on the diazo component used. In comparison, Naphthol AS typically produces standard red shades, while AS-BO is used for deep maroon to violet shades.

Main applications include cotton yarn, cotton fabrics, cotton knitwear, towels, and bath towels. Also suitable for viscose, vinylon, silk, nylon, and diacetate fiber dyeing. Used for cotton fabric direct printing, resist printing, and discharge printing. It can also be blended with Naphthol AS to improve dyeing fastness.

When combined with different fast color bases, Naphthol AS-OL can produce a wide spectrum of shades including orange, red, maroon, and blue. This versatility makes it a valuable product for dye houses requiring multiple shades from a single coupling component.

Naphthol AS-OL offers excellent solubility in caustic soda solution---superior to AS-RL and AS-BO. It provides good dyeing fastness and can be blended with Naphthol AS to improve overall fastness properties. It is also used as an intermediate for producing organic pigments including Pigment Red 9, 15, 119, 243, 261, 266, and Pigment Orange 4.

Naphthol AS-OL is produced by reacting 2,3-acid (3-hydroxy-2-naphthoic acid) with o-anisidine (2-methoxyaniline) in the presence of a condensing agent such as phosphorus trichloride (PCl3) in an organic solvent. The product is then neutralized, filtered, washed, and dried to obtain the final powder.