Naphthol AS-PH produced by our works is made from 2-hydroxy-3-naphthoic acid and o-amino methylphenoxide by processes of condensation between them. When it is coupled with red base diazo salt on cotton fibre, the insoluble azoic color will be fromed. This kind of azoic color is characterized by brilliant shade, high color-giving volume, excellent fastness, low cost and low energy consumption. Owing to a rather high affinity with cotton, it can be used as ground agent for printing and dyeing of cotton fiber. In addition, ot finds application in dyeing of viscose fibre, ramie & flax fibre, vinylon viscose fibre, ect.

Structural Formula:

Molecular formula: C19H17O3N
Molecular weight:307.4

Quality Standards of Naphthol AS-PH

Description	Specification
Appearance	light yellowish white even powder
Shade and strength when coupling with Naphthol As on cotton fibre	similar to the standard
Primary melting point of the dried	≥150°C
Insoluble matter in alkali	≤0.5%
Percentage of screenings(80 mesh)	≤5.0%