Crosslinking characteristics of dual-curable blocked isocyanate with thermal radical initiator for lowering curing temperature of automotive clearcoats

A novel dual-curable blocked isocyanate crosslinker was designed for the simultaneous radical and urethane crosslinking of automotive clearcoats under low-temperature conditions. Three groups on three ends hexamethylene diisocyanate-based were using two different blocking agents: a thermal initiator (TRI) dimethyl pyrazole. Clearcoats based hydroxyl-functionalized methacrylate oligomer resin hybrid (BITD) confirmed to be densely crosslinked by radial reactions occurring at curing temperature 130 °C, which condition is lower than conventional 150 °C. comparison real-time behavior clearcoat mixtures thermo-mechanical surface hardness properties post-cured films revealed that performance BITD better mono-curable TRI commercial crosslinker. This study demonstrated through correlation between characteristics coating performance, it possible actively implement technology utilizing isocyanate. • containing an with DMP synthesized. Crosslinking demonstrated. can contribute cleracoats.