Resin Acid

any of the isomeric cyclic carboxylic acids with the general formula C₁₉H₂₉COOH. The category also includes the dihydro, tetrahydro, and dehydro derivatives—C₁₉H₃₁COOH, C₁₉H₃₃COOH, and C₁₉H₂₇COOH-of the acids. Resin acids are found in significant quantities in soft resin (60–65 percent), tall oil (30–60 percent), and rosin (80–95 percent), which is obtained by processing tall oil or soft resin. For example, there are nine resin acids in the soft resin of the Scotch pine, among them abietic acid and L-pimaric acid. Resin acids are used in industry usually in the form of rosin and such rosin derivatives as esters.