Nomenclature
Colophony; yellow resin; abietic anhydride. Description and references
Residue left after distilling off the volatile
oil from the oleoresin obtained from Pinus palustris and
other species of Pinus, Pinaceae. Offered as wood rosin
(from Southern pine stumps), gum rosin (the exudate from incisions
in the living tree, P. palustris and P. caribaea), and tall oil rosin, see Tall
Oil. Rosin is chiefly produced in the U.S.A. Constit. About 90% resin acids and 10% neutral matter. Of the resin acids
about 90% are isomeric with abietic acid (C20H30O2); the other 10% is a mixture of dihydroabietic acid
(C20H32O2) and dehydroabietic acid
(C20H28O2).
Properties
Pale yellow to amber, translucent fragments; brittle
fracture at ordinary temp; slight turpentine odor and taste. Readily
fusible when heated. d 1.07-1.09. Acid no. not less than 150. Insol in water. Freely sol in
alc, benzene, ether, glacial acetic acid, oils, carbon disulfide;
also sol in dil solns or fixed alkali hydroxides.Use
Manuf varnishes, varnish and paint driers, printing
inks, cements, soap, sealing wax, wood polishes, floor coverings,
paper, plastics, fireworks, tree wax, sizes, rosin oil; for water-proofing
cardboard, walls, etc. Pharmaceutic aid (stiffening agent).