Unsaturated Polyester Resin (UPR) from Japan
Liquid unsaturated polyester resin for fiberglass composites in marine and construction applications, supplied in primary form before curing. It enters HTS 3907.99.5050 as 'other polyesters' per predominant dicarboxylic acid/diol monomer content per subheading note (a).
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
• Include Safety Data Sheets (SDS) detailing uncured resin status and monomer composition for primary form verification
• Avoid common pitfall of classifying styrene-monomer blends incorrectly; styrene <5% keeps it polyester-dominant
• Confirm not chemically modified beyond base polymer to stay out of generic 'Other' provisions