Urea-Thiourea Copolymer Resin from Mexico
Copolymer where urea units predominate over thiourea (>95% combined per subheading note), used in paper impregnation. HTS 3909.10.00.00 covers as urea resin series with predominant monomer. Improves wet strength in specialty papers.
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
• Analyze comonomer ratio via NMR for customs; declare nitrogen/sulfur content indirectly verifying composition; avoid high humidity storage causing clumping