<i>ALCURE</i> 4400 Polymeric Isocyanate Curative Hexion Specialty Chemicals North America Central and Eastern Europe Polyurethane (PU) - Isocyanates >> IPDI, isophorone diisocyanate (cycloaliphatic) Coatings Powder coating Alcure 4400 is a polymeric, aliphatic, isocyanate curative based on IPDI and blocked with e-caprolactam. Provides excellent flow, exterior durability and good overall performance. Polymeric, aliphatic, isocyanate curative based on IPDI and blocked with e-caprolactam. Used in powder coatings. Provides very good flow. Offers exterior durability and good overall performance.