HDI Biuret Trimer (Desmodur N 100) from Japan
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 — Japan → United States
12.5%
Rate breakdown
9903.05.4912.5%Except for products described in headings 9903.05.85–9903.05.92, articles the product of Japan, with an ad valorem (or ad valorem equivalent) rate of duty under column 1 less than 12.5 percent, 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