Cyanate Ester Resin Flakes
Thermosetting cyanate ester resin flakes for radar-transparent composites. HTS 3911.90.91.50 covers this primary form thermoset NES in Chapter 39.
Import Duty Rates by Country of Origin
Alternative Classifications
This product could be classified differently depending on its characteristics or intended use.
If amino resins with urea/melamine dominance
If cyanate modified from amino base with 95% content, goes to 3909 series.
If formulated as prepared adhesives
Adhesives and prepared glues from polymers classified in 3506 regardless of base.
If cast into sheets >6mm thick
Thick plates/sheets of thermosets in 3920.99 by physical form.
Not sure which classification is right?
The Tariff Assistant works through the GRI rules on your specific product to reach the right HTS code — and can price the duty on it in the same conversation.
Import Tips & Compliance
• DSC analysis mandatory to demonstrate >200°C curing without melting
• Avoid 'adhesive' labeling; shifts to 3506 if prepared for bonding applications
• Declare low moisture content (<0.1%) to preserve thermoset reactivity
Related Products under HTS 3911.90.91.50
Melamine-Formaldehyde Resin Granules
Thermosetting melamine-formaldehyde resin in granular primary form, used for molding durable laminates and coatings. Classified under HTS 3911.90.91.50 as a thermosetting polymer not elsewhere specified, meeting the criteria where the monomer units contribute over 95% by weight per subheading note (a)(1).
Urea-Formaldehyde Resin Powder
Thermosetting urea-formaldehyde resin powder in primary form for particleboard adhesives and molded products. Falls under 3911.90.91.50 as a thermosetting product NES, compliant with polymer classification rules based on predominant monomer weight.
Epoxy Novolac Resin Pellets
High-performance thermosetting epoxy novolac resin in pellet form for electronics encapsulation. HTS 3911.90.91.50 applies to this NES thermosetting polymer in primary form, where epoxy and novolac units predominate per note (a)(4).
Diallyl Phthalate Resin Granules
Thermosetting diallyl phthalate (DAP) resin granules for high-temperature electrical components. Classified in 3911.90.91.50 as other thermosetting polymers in primary forms not specified elsewhere.
Polyimide Prepolymer Powder
Thermosetting polyimide prepolymer powder in primary form for aerospace composites. Under 3911.90.91.50 as NES thermosetting product, classified by predominant imide monomer units.
Bismaleimide Resin Pellets
High-temp bismaleimide (BMI) thermosetting resin pellets for aircraft structures. Primary form classification under 3911.90.91.50 as other thermosets.