UV-328 is a benzotriazole-based UV absorber with excellent light protection and thermal stability. It provides broad UV shielding in the 290–400 nm range, reducing photo-degradation in a variety of polymer systems.
Its low color contribution and good compatibility make it suitable for transparent and pigmented systems alike. UV-328 is particularly effective in semi-crystalline polymers and solvent-based coatings where long-term exposure to sunlight is expected.
| Property | Typical Value |
|---|---|
| Chemical Name | 2-(2H-Benzotriazol-2-yl)-4-(tert-butyl)-6-(sec-butyl)phenol |
| CAS No. | 25973-55-1 |
| Appearance | Light yellow powder |
| Melting Point | 80 – 86 °C |
| UV Absorption Range | 290 – 400 nm |
| Volatility | Low |
| Purity | > 99% |
| Recommended Dosage | 0.1 – 0.5 phr |
| Common Problem | UV-328 Solution |
|---|---|
| UV fading and yellowing | Broad UV protection reduces discoloration |
| Surface degradation in sun | Maintains gloss, flexibility, and clarity |
| High heat causing additive loss | Low volatility ensures retention |
| Polymer breakdown in transparent items | Protects molecular chains from UV attack |
| Regulatory-sensitive applications | High purity ensures product safety |
Q1: What is the difference between UV-328 and UV-327?
UV-328 offers slightly better performance in semi-crystalline polymers and has higher purity, which is preferred in sensitive applications.
Q2: Can UV-328 be used in combination with HALS?
Yes, it is often paired with HALS like Tinuvin 622 or Chimassorb 944 to achieve long-term outdoor stability.
Q3: Is UV-328 suitable for transparent materials?
Yes, due to its low color and good light stability, UV-328 is ideal for clear applications.
Q4: What is the shelf life of UV-328?
At least 24 months if stored properly in original packaging.
Q5: Does UV-328 meet REACH or RoHS?
Yes. Please request the regulatory data sheet for certification.
