UV Absorbers
UV Absorber UV-329
2-(2H-Benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol
The near-white benzotriazole for transparent plastics and high-clarity coatings.
Product Description
UV-329 is a benzotriazole UV absorber distinguished by its white crystal color and minimal contribution to substrate color, making it the preferred benzotriazole for transparent polycarbonate, PMMA and high-clarity coatings where any yellow tint is unacceptable.
It absorbs strongly in the 300–375 nm band, preventing the photo-Fries reactions that yellow polycarbonate and protecting PMMA sheet from craze-forming UV exposure. In coatings it shields both binder and substrate with excellent permanence and low volatility.
Typical loadings are 0.1–0.5 wt% in transparent plastics and 1–3 wt% in coating solids. Aolong UV-329 is crystallized to ≥99.0% assay with transmittance ≥97% at 450 nm in solution, guaranteeing optical clarity.
Key Features
- White crystal color — no yellow shift in clear products
- Ideal for transparent PC, PMMA and PET
- High transmittance in visible light
- Broad food-contact and cosmetic approvals
Applications
- Polycarbonate sheet, glazing and lenses
- PMMA acrylic sheet and lighting diffusers
- Clear industrial and wood coatings
- PET packaging and sheets
- Cosmetic and personal care formulations (grade-dependent)
Specifications
| CAS No. | 3147-75-9 |
|---|---|
| Molecular Formula | C20H25N3O |
| Molecular Weight | 323.44 |
| Appearance | White to off-white crystalline powder |
| Assay (HPLC) | ≥ 99.0% |
| Melting Point | 101 – 106 °C |
| Transmittance (450 nm, 1 g/100 mL toluene) | ≥ 97% |
| Loss on Drying | ≤ 0.5% |
Packaging & Storage
25 kg fiber drum with PE liner or 25 kg carton. Store cool, dry and protected from light; shelf life 24 months in original sealed packaging.
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