R-Acid (3-Hydroxy-2-Naphthoic Acid)
CAS Number: 148-75-4
R-Acid, also known as 3-hydroxy-2-naphthoic acid (BON acid), is a classic azo coupling component widely used in the production of fast, insoluble azo pigments and printing pastes for textiles and packaging. It couples with diazonium salts at the 1-position to yield high chroma red, orange, and maroon azo colors extensively used in offset and flexographic printing inks. Chemzip supplies R-Acid to pigment and ink manufacturers requiring consistent coupling performance.
Technical Specifications
| appearance | White to pale yellow crystalline powder |
| purity (%) | ≥99.0 |
| heavy metals (ppm) | ≤10 |
| melting point (°C) | 221–224 |
Applications
- Insoluble azo pigment synthesis (Naphthol AS series)
- Textile printing paste preparation
- Offset and flexographic ink pigment intermediate
- Solvent dye and varnish colorant synthesis
- Plastics colorant intermediate
Key Features
- High purity ≥99.0% yields vivid, high-chroma red pigment shades
- Tight melting point control ensures reproducible coupling reactions
- Low heavy metals complies with EU packaging directive requirements
- Widely compatible with various diazonium salt systems
Send Inquiry
CAS Number
148-75-4
Category
Dye / Pigment IntermediatesAvailability
In StockSample
Dispatched within 5 days