Sulfanilic Acid
CAS Number: 121-57-3
Sulfanilic acid (4-aminobenzenesulfonic acid) is a water-soluble aromatic amino sulfonic acid that serves as both a diazo component and coupling component in the manufacture of water-soluble direct, acid, and reactive azo dyes. Its sulfonic acid group imparts water solubility to the resulting dyes and improves affinity for protein and polyamide fibers. Chemzip offers industrial-grade sulfanilic acid with consistent quality for dye manufacturers.
Technical Specifications
| appearance | White to off-white crystalline powder |
| purity (%) | ≥99.0 |
| insoluble matter (%) | ≤0.1 |
| sulfonic acid group (%) | ≥28.5 |
Applications
- Water-soluble direct dye synthesis for cotton
- Acid dye intermediate for wool and nylon
- Reactive dye building block
- Optical brightening agent (OBA) intermediate
- Clinical diagnostics reagent (diazotization-based assays)
Key Features
- High purity ensures consistent diazotization yield and coupling efficiency
- Low insoluble matter prevents reactor clogging in continuous processes
- Zwitterionic structure provides good crystal stability during storage
- Bulk supply capability with dedicated storage tanks at production site
Send Inquiry
CAS Number
121-57-3
Category
Dye / Pigment IntermediatesAvailability
In StockSample
Dispatched within 5 days