3911.90.35.00 - 1,1'-Bis(methylenedi-4,1-phenylene)- 1H-pyrrole-2,5-dione, copolymer with 4,4'-methylenebis(benzeneamine); and Hydrocarbon novolac cyanate ester

This HTS category, 3911.90.35.00, specifically classifies a particular type of thermosetting plastic resin. The core components are the copolymer of 1,1'-Bis(methylenedi-4,1-phenylene)-1H-pyrrole-2,5-dione with 4,4'-methylenebis(benzeneamine), and a hydrocarbon novolac cyanate ester. These materials are characterized by their thermosetting nature, meaning they undergo irreversible chemical changes when heated, forming a rigid, infusible network. Their primary form dictates their classification here, prior to further processing or fabrication into articles.

Distinguishing this specific classification from its sibling, 3911.90.45.00 (Other), lies in the precise chemical composition and the presence of the defined copolymer and hydrocarbon novolac cyanate ester. While the sibling category would encompass other thermosetting resins not meeting the specific criteria of 3911.90.35.00, this entry is reserved for the described advanced resin systems known for their high performance characteristics, often utilized in demanding applications. The key differentiator is the explicit mention of the named chemical entities within the description.

As this is a leaf node in the HTS classification structure, there are no subcategories to introduce. Classification at this level is definitive, requiring careful examination of the imported goods against the detailed chemical description provided. Importers must confirm that the product is indeed composed of or derived from the specified copolymer and hydrocarbon novolac cyanate ester to correctly apply this classification code. The absence of further subdivisions emphasizes the specificity of this particular resin type within the broader context of thermosetting plastics.