UV Absorber Liquid Benzotriazole (Tinuvin 384 Type)

UV Absorber Liquid Benzotriazole (Tinuvin 384 type, CAS 127519-17-9) is a long-chain alkyl ester-modified benzotriazole UV absorber that is liquid at room temperature, providing superior ease of handling and dissolution compared to solid benzotriazole grades like Tinuvin 328 type. The liquid form eliminates the heating and dissolution steps required for solid UVAs, enabling direct addition to gelcoat pastes, liquid resin systems, and coating formulations at ambient temperature.

The liquid benzotriazole structure provides excellent compatibility with the full range of UPR, VER, and epoxy resin systems, including styrene-containing and styrene-free formulations. The longer alkyl chain of the 384 type provides lower migration and volatility than simpler liquid benzotriazoles, making it suitable for applications requiring sustained long-term UV protection. UV absorption spectrum covers 300–380 nm, providing strong protection against the wavelengths most responsible for photooxidation in aromatic polyester and epoxy chromophores.

In production gelcoat manufacturing, Tinuvin 384 type simplifies the manufacturing process by eliminating the heating step required to dissolve solid benzotriazole. It is pre-mixed into the gelcoat paste before pigment and thixotropic agent addition, ensuring uniform distribution. At 0.3–1.0 phr in gelcoat combined with 0.2–0.5 phr HALS, it provides comprehensive UV protection for 8–15 years in typical European outdoor exposure conditions. For extremely demanding applications (desert exposure, tropical marine), higher loadings and supplementary UV protection strategies may be needed.