UV-531 (2-Hydroxy-4-n-octyloxy benzophenone) is a classic benzophenone-based UV absorber. It protects polymers by absorbing UV radiation in the 270–340 nm range and converting it into harmless heat. This prevents photodegradation and helps maintain appearance, flexibility, and mechanical strength of materials exposed to sunlight.
| Property | Typical Value |
|---|---|
| Chemical Name | 2-Hydroxy-4-n-octyloxy benzophenone |
| CAS No. | 1843-05-6 |
| Molecular Formula | C14H20O3 |
| Appearance | Light yellow powder or granule |
| Melting Point | 47 – 50 °C |
| UV Absorption Range | 270 – 340 nm |
| Volatility | Low |
| Recommended Dosage | 0.1 – 0.5 phr |
| Issue | How UV-531 Helps |
|---|---|
| Yellowing of transparent plastics | Absorbs UV before it reaches the matrix |
| Premature aging of outdoor materials | Slows down UV-induced chain scission |
| Surface cracking or loss of gloss | Maintains mechanical and visual quality |
| Coating failure in sunlight | Enhances weathering resistance |
Q1: Can UV-531 be used in food packaging?
UV-531 is not approved for direct food contact. Please confirm with regulatory requirements if intended for sensitive use.
Q2: Can I mix it with HALS or other UV stabilizers?
Yes. UV-531 works well with HALS (e.g., Tinuvin 770) for better long-term outdoor protection.
Q3: What’s the shelf life of UV-531?
Typically 2 years if kept sealed in a dry, cool environment.
Q4: Is UV-531 suitable for clear products?
Yes. It is especially effective in transparent or semi-clear plastics and coatings.
Q5: Can UV-531 survive high processing temperatures?
Yes. It is thermally stable under standard plastic processing conditions such as extrusion or injection.
