Optical Brightener OB-1 is a high-temperature resistant fluorescent whitening agent that absorbs ultraviolet light and re-emits blue light to mask yellowing. It features exceptional thermal stability up to 375–400 °C, making it ideal for engineering plastics, polyester, and nylon. Common Applications • Plastics & Polymers: Used in PET, PP, PC, PS, ABS, HIPS, PA, EVA, and rigid PVC • Fibers & Textiles: Widely applied in polyester fibers, nylon, and polyester-cotton blends • Recycled Materials: Restores visual brightness to recycled polymer waste, flake, and bottle materials Recommended Dosage • Transparent Polymers: 0.0025% – 0.005% • Standard / General Use: 0.01% – 0.05%
| CAS Number | 1533-45-5 |
| Color Index / FBA Number | C.I. 393 / FBA 393 / OBA 393 |
| Appearance | Bright yellowish-green crystal powder |
| Melting Point | ~357 °C – 361 °C (high thermal stability up to 375–400 °C) |
| Molecular Formula | C₂₈H₁₈N₂O₂ |