Products described in additional U.S. note 3 to section VI
Oxygen-function amino-compounds: > Amino-naphthols and other amino-phenols, other than those containing more than one kind of oxygen function, their ethers and esters; salts thereof: > Aminohydroxynaphthalenesulfonic acids and their salts: > Other: > Products described in additional U.S. note 3 to section VI
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 9903.88.39, 9903.88.42, 9903.88.44, 9903.88.47, 9903.88.49, 9903.88.51, 9903.88.53, 9903.88.55, 9903.88.57, 9903.88.65, 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(r) to this subchapter and as provided for in the subheadings enumerated in U.S. note 20(s)
Products classified under HTS 2922.21.40.00
Schaeffer's Salt (2-Naphthylamine-6-sulfonic Acid)
Schaeffer's salt is a sodium salt of 2-naphthylamine-6-sulfonic acid, a key aminohydroxynaphthalenesulfonic acid derivative used primarily as an intermediate in azo dye synthesis. It falls under HTS 2922.21.4000 as a product described in additional U.S. note 3 to section VI, which covers specific organic compounds subject to quota restrictions for dye production. The compound features both amino and sulfonic acid oxygen functions on a naphthalene ring.
Tobias Acid (2-Naphthylamine-8-sulfonic Acid)
Tobias acid is the sodium salt of 2-naphthylamine-8-sulfonic acid, widely used as a diazo component in manufacturing acid dyes and pigments. Classified under HTS 2922.21.4000 due to its status in additional U.S. note 3 to section VI, restricting imports for dye production. It qualifies as an oxygen-function amino-compound with amino, hydroxy, and sulfonic groups.
Bayer's Acid Salt (1-Naphthylamine-4-sulfonic Acid Sodium Salt)
Bayer's acid sodium salt serves as a crucial intermediate for direct and reactive dyes, featuring the aminohydroxynaphthalenesulfonic acid structure. It is specifically listed under HTS 2922.21.4000 per additional U.S. note 3 to section VI for quota-controlled dye chemicals. The compound's classification follows chapter rules prioritizing oxygen-function amino-phenols.
Neville-Winter Acid (1-Naphthylamine-5-sulfonic Acid)
Neville-Winter acid is an aminohydroxynaphthalenesulfonic acid used in acid dye manufacturing, subject to HTS 2922.21.4000 quotas under U.S. note 3 to section VI. Its structure with amino group ortho/para to sulfonic acid enables diazotization for azo coupling. Classification adheres to chapter priority for oxygen-function amino-naphthols.
Laurent's Acid (2-Naphthylamine-3,6-disulfonic Acid)
Laurent's acid, a di-sulfonic derivative of 2-naphthylamine, functions as a dye coupler in textile coloration chemistry. Covered by HTS 2922.21.4000 as specified in additional U.S. note 3 for import quotas. Despite two sulfonic groups, it remains classified here due to primary amino-hydroxy-naphthalene structure.
K-acid (4-Amino-5-hydroxynaphthalene-2,7-disulfonic Acid)
K-acid serves as an important coupling component for substantive dyes due to its multiple sulfonic groups enhancing water solubility. HTS 2922.21.4000 applies per U.S. note 3 listing for quota purposes. The compound exemplifies oxygen-function amino-naphthols with salt-forming capability.