3204.13 - Basic dyes and preparations based thereon:

Category 3204.13 encompasses "Basic dyes and preparations based thereon." Basic dyes are a class of synthetic organic coloring matter characterized by their cationic nature, meaning they possess a positive electrical charge. This charge allows them to readily bind to negatively charged substrates, making them particularly effective for dyeing materials like acrylic fibers, modified polyesters, paper, and leather. Preparations based on basic dyes include mixtures or formulations containing these dyes, often with additives to improve solubility, stability, or application properties.

This category is distinct from its sibling categories which classify other major types of synthetic organic dyes. For instance, disperse dyes (3204.11) are non-ionic and used for hydrophobic fibers like polyester and acetate, while acid dyes (3204.12) are anionic and used for protein fibers like wool and silk. Direct dyes (3204.14) are also anionic but have a high affinity for cellulosic fibers like cotton without requiring a mordant. Vat dyes (3204.15) are insoluble in water and are applied through a reduction-oxidation process, and reactive dyes (3204.16) form a covalent bond with the fiber.

The subcategories within 3204.13 further refine the classification based on specific named dyes or more general groupings. For example, some subdivisions list specific common names and HTS numbers for widely used basic dyes such as Basic black 7 and various basic blues, oranges, reds, violets, and yellows, highlighting distinct chemical entities. Other subcategories might group less commonly specified basic dyes under a general "Other" designation, ensuring all basic dyes not explicitly listed are appropriately categorized. This detailed breakdown aids in precise identification and compliance with customs regulations.