4,4'-Diamino-2,2'-stilbenedisulfonic acid
Amine-function compounds > Aromatic polyamines and their derivatives; salts thereof: > Other: > 4,4'-Diamino-2,2'-stilbenedisulfonic acid
Duty Rate (from China)
Except for products described in headings 9903.03.02–9903.03.11, articles the product of any country, as provided for in subdivision (aa) of U.S. note 2 to this subchapter
Except as provided in headings 9903.88.13, 9903.88.18, 9903.88.33, 9903.88.34, 9903.88.35, 9903.88.36, 9903.88.37, 9903.88.38, 9903.88.40, 9903.88.41, 9903.88.43, 9903.88.45, 9903.88.46, 9903.88.48, 9903.88.56, 9903.88.64, 9903.88.66, 9903.88.67, 9903.88.68, or 9903.88.69, articles the product of China, as provided for in U.S. note 20(e) to this subchapter and as provided for in the subheadings enumerated in U.S. note 20(f)
Products classified under HTS 2921.59.20.00
4,4'-Diamino-2,2'-stilbenedisulfonic acid
This is a specific aromatic polyamine derivative with two amino groups and sulfonic acid groups, classified under HTS 2921.59.2000 as it exactly matches the chemical structure of 4,4'-diamino-2,2'-stilbenedisulfonic acid. It serves as a key intermediate in dye synthesis, particularly for direct dyes used in textile coloring.
DAS (4,4'-Diamino-2,2'-stilbenedisulfonic acid) Technical Grade
Technical grade DAS is a high-purity form of 4,4'-diamino-2,2'-stilbenedisulfonic acid used in optical brightener production. It falls under HTS 2921.59.2000 due to its precise chemical identity as a chemically defined aromatic polyamine per Chapter 29 note (a). Impurities are minimal and do not alter its classification.
4,4'-Diaminostilbene-2,2'-disulfonic acid Powder
Powdered form of 4,4'-diamino-2,2'-stilbenedisulfonic acid, a white to light yellow crystalline compound used as a dye precursor. Classified specifically under HTS 2921.59.2000 as a separate chemically defined organic compound per Chapter 29 scope. The powder form with anti-caking agent is allowed under note (f).