Sulfanilic acid

Sulfanilic acid (CAS 121-57-3), also known as sulphanilic acid, is an aminosulfonic acid used as a key intermediate in the synthesis of azo dyes, optical brighteners, and specialty chemicals. Its bifunctional structure, carrying both amine and sulfonic acid groups, makes it a productive building block for coupling reactions in dye manufacturing and industrial chemical synthesis.

In textile dyeing, this compound is diazotized and coupled with naphthol or other aromatic compounds to produce direct and reactive azo dyes used on cotton and wool fibers. The paper and packaging industries rely on it to manufacture fluorescent whitening agents that improve brightness in various coated and uncoated paper grades across the global market.

Leather processing operations use derivatives of this acid to achieve consistent, penetrating coloration on finished hides. It also functions as a cross-linking component in polymeric colorants. Furthermore, it is utilized in the production of pigment dispersants for printing inks. The material is supplied as a white to off-white crystalline powder for industrial handling.

Technical grade is the standard commercial form, with purity typically specified at 99% minimum for dye intermediate applications. Reagent-grade material is available for laboratory use. Analytical applications often require tighter specifications for consistency. Our product meets rigorous industrial benchmarks to ensure performance in complex chemical synthesis and manufacturing.