UV-Stabilized Outdoor UPR

UV-Stabilized Outdoor UPR is an isophthalic unsaturated polyester resin pre-formulated with UV absorbers (benzotriazole or triazine type) and HALS (hindered amine light stabilizers) to provide extended outdoor weathering performance in exposed FRP applications. The resin is designed for translucent roofing sheets, outdoor architectural panels, recreational vehicle skins, and other applications where long-term color retention, gloss retention, and structural integrity under UV/QUV exposure are required.

The UV stabilizer package is selected to work synergistically: UV absorbers screen out UV radiation in the 280-380 nm range before it reaches the aromatic polyester backbone, while HALS molecules interrupt the photooxidation radical chain reaction. This dual protection mechanism extends the outdoor service life of FRP laminates significantly compared to unstabilized grades.

After 2,000 hours QUV accelerated weathering, color change (ΔE) is typically <5 and gloss retention >70% versus unstabilized controls. Viscosity at 25°C is 300-550 mPa·s, suitable for hand lay-up and filament winding. The resin is compatible with standard MEKP/cobalt cure systems and UV-screened gelcoats for maximum outdoor durability.