HDI Biuret Trimer (Desmodur N 100) from Mexico
HDI Biuret trimer is a high-functionality polyisocyanate derived from 1,6-hexamethylene diisocyanate, containing residual monomeric HDI (<0.25%). It qualifies under HTS 2929.10.3500 as an isocyanate per Chapter notes allowing derivatives of listed compounds. Primarily used as crosslinking agent in durable industrial coatings.
Duty Rate — Mexico → United States
16.5%
Rate breakdown
9903.05.5510%Except for products described in headings 9903.05.85–9903.05.92 and 9903.05.94, articles the product of Mexico, as provided for in U.S. note 52 to this subchapter
Import Tips
• Provide analytical certificate showing NCO content (typically 21-22%) and residual monomer <0.3% to confirm isocyanate identity
• Moisture exclusion critical—use nitrogen-blanketed containers to prevent gelling during ocean transit
• Avoid classification disputes by documenting it's not a 'finished coating' (3208/3209) but reactive intermediate