.~ Rosin, tall oil, or derivatives thereof containing (except abietic acids or fatty acids derived therefrom)
DEFINITION
Classification: 44/306
Rosin, tall oil, or derivatives thereof containing (except abietic acids or fatty acids derived therefrom):
(under subclass 300) Compositions which contain tall oil, rosin or derivatives thereof, excluding fatty acids, per se, or abietic acids, per se, derived from tall oil or rosin.
(1) Note. Tall oil is a by-product of the wood pulp industry and is usually recovered from pine wood "black liquor" of the sulfate or kraft paper processes. A typical composition of tall oil includes 50-60 percent fatty acids (e.g., oleic, linoleic, etc.), 34-40 percent rosin acids, and 5-10 percent unsaponifiable matter, such as long chain alcohols and sterols.
(2) Note. Rosin, also known as colophony, is usually designated according to its source, e.g., gum rosin (from exudate of incisions on living trees); wood rosin (from Southern pine stumps); and tall oil rosin (from by-products of the wood pulp industry). The principal constituents isolated from rosin are carboxylic acids with a hydrophenanthrene nucleus, comprising abietic acid and its
isomers, such as pimaric acid. The acids may exist in rosin as acid anhydrides. The mixed acids are known in the trade as rosin acids or resin acids, the two expressions being used interchangeably.
(3) Note. Abietic acid has the following structure: [figure]
