HDI trimer polyisocyanate

HDI trimer is an aliphatic polyisocyanate used to crosslink hydroxyl-functional resins. Its multiple isocyanate groups react with polyol groups to build a three-dimensional polyurethane network, improving chemical resistance and mechanical durability. The aliphatic structure supports light stability and color retention in appropriately formulated coatings.

The selected material is an unblocked, solvent-free HDI-isocyanurate crosslinker rather than monomeric HDI. It is mixed with a compatible hydroxyl-functional component shortly before use in a two-component system. The isocyanurate core provides higher functionality, while the resin partner and formulation establish flexibility, hardness and application viscosity. Moisture sensitivity follows the reactive NCO groups and is part of the curing chemistry.

Typical Applications

• Two-component polyurethane topcoats: Used as the hardener component with suitable acrylic or polyester polyols in industrial and protective coating systems.
• Automotive and transportation refinishing: Used in formulated clearcoats or pigmented finishes where light stability, appearance and chemical resistance are required.
• Durable wood and plastic finishes: Used in compatible two-component coatings to develop a crosslinked film resistant to handling and service chemicals.

Specifications

Specifications describe the standard grade. Tolerance, test method and documentation package are confirmed per order.