For styrene block copolymers (SBS, SIS), UV protection is particularly important, as they degrade more rapidly under UV radiation. The choice of the right UV stabilizers depends on the desired long-term stability, color retention, and mechanical requirements.
Recommended UV Stabilizers for SBS & SIS TPEs
Benzotriazole-based UV absorbers are particularly effective for transparent and light-colored compounds. They absorb UV radiation in the 290–400 nm range and prevent photochemical degradation reactions.
Additives from the WTH product range: WTH-UV 328, WTH-UV 360
Triazine-based UV absorbers offer higher thermal stability than benzotriazoles and are effective for high-performance applications requiring increased temperature resistance.
Additive from the WTH product range: WTH-UV 1577
HALS (Hindered Amine Light Stabilizers) act as radical scavengers and prevent degradation caused by UV-induced oxidation. They are particularly suitable for darker colors and heavily stressed outdoor applications.
Additive from the WTH product range: WTH-LS 944
Properties of UV Absorber and HALS Combinations
Benzotriazole + HALS: Optimal for long-lasting applications with good color stability.
Triazine + HALS: Ideal for high-performance SBS/SIBS under high thermal stress.
TPEs are widely used in various applications, such as:
- Automotive industry: Seals, interior trims, and flexible grips.
- Sports and leisure products: Bicycle grips, soft-touch surfaces, and protective gear.
- Packaging and consumer goods: Soft components of toothbrushes or cosmetic packaging.
Conclusion
A combination of benzotriazole/triazine UV absorbers and HALS provides the best protection against UV degradation for SBS and SIS.
