3812.39.30.00 - Master batches of poly[nitrilomethanetetraaryl- nitrilo[2,4,6- tris(1-methylethyl)-1,3- phenylene]]-2,6-bis(1-methylethyl)phenyl]-ω- [[[[2,6-bis(1-methylethyl)phenyl]amino]- methylene]amino]carbodiimide or 2,4-diisocyanate-1,3,5-tris(1-methylethyl)- benzene homopolymer with polyethylene, polyethylene terephthalate, or thermoplastic polyurethanes;Master batches of 3-(2H-benzotriazol-2-yl)-5- (tert-butyl)-4-hydroxybenzenepropanoic acid, C7-C9 branched or linear alkyl esters; andMaster batches of α-[3-[3-(2H-benzotriazol-2- yl)-5-(1,1-dimethylethyl)-4-hydroxyphenyl]-1- oxopropyl-ω-[3-[3-(2H-benzotriazol-2-yl)-5- (1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxo- propyl] poly(oxyethylene)

This HTS classification, 3812.39.30.00, covers specialized master batches designed as anti-oxidizing preparations and other compound stabilizers for rubber or plastics. Specifically, it encompasses master batches containing complex chemical compounds such as poly[nitrilomethanetetraaryl- nitrilo[2,4,6- tris(1-methylethyl)-1,3- phenylene]]-2,6-bis(1-methylethyl)phenyl]-ω- [[[[2,6-bis(1-methylethyl)phenyl]amino]- methylene]amino]carbodiimide or 2,4-diisocyanate-1,3,5-tris(1-methylethyl)- benzene homopolymer with polyethylene, polyethylene terephthalate, or thermoplastic polyurethanes. Additionally, it includes master batches of specific benzotriazole derivatives used as UV absorbers and stabilizers, such as 3-(2H-benzotriazol-2-yl)-5-(tert-butyl)-4-hydroxybenzenepropanoic acid, C7-C9 branched or linear alkyl esters, and α-[3-[3-(2H-benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxyphenyl]-1- oxopropyl-ω-[3-[3-(2H-benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxyphenyl]-1-oxo- propyl] poly(oxyethylene). These preparations are crucial for enhancing the durability and lifespan of polymeric materials by preventing degradation caused by oxidation and UV radiation.

This classification is distinguished from its sibling category, 3812.39.20.00, which specifically covers mixtures of N,N'-diaryl-p-phenylenediamines. While both are stabilizers for rubber and plastics, 3812.39.30.00 addresses more complex, often polymeric or esterified, chemical structures, including those with benzotriazole moieties, which are not typically found in the simpler diaryl-p-phenylenediamine mixtures. The "Other" category at 3812.39.60.00 serves as a residual classification for stabilizers not meeting the specific criteria of other subheadings within this group.

As this HTS code is a leaf node, it represents the most specific level of classification for these particular master batches. Therefore, classification under this subheading depends on the precise chemical composition as outlined in the description. Importers and exporters should meticulously verify the chemical identity of the master batch against the specific components listed to ensure correct classification.