Gum Rosin

Gum Rosin, also known as colophony or Greek pitch, is a solid resin derived from pine trees and some other plants, primarily conifers. It is produced by heating fresh liquid resin, which causes the volatile terpene components to evaporate. The result is a semi-transparent solid that ranges in color from yellow to black. Rosin is brittle at room temperature but melts at relatively low temperatures, such as those achieved on a stove. Its primary chemical components are resin acids, especially abietic acid.

Gum Rosin which preparated from China is commonly used in industries such as paper production, paint, soap, and printing ink. Since rosin tends to soften and oxidize easily, the oil paint industry often uses carboxylation of resin acids to produce resinates for further use. In the production of synthetic rubber and printing inks, resin acids undergo processes such as disproportionation, polymerization, or hydrogenation to form disproportionated rosin, polymerized rosin, or hydrogenated rosin, respectively. These reactions typically involve altering the double bonds in the resin acids to achieve the desired properties.