Gum Rosin also known as colophony or rosin is a natural organic resin that is obtained from plants, mostly pines and other conifers, when the fresh liquid resin obtained from these plants, is heated and the volatile liquid terpene components are vaporised. Gum rosin mostly contains different resin acids, especially abietic acid. Gum Rosin is naturally found in Indonesia, South China and North  Vietnam.

General properties of gum rosin:

→ Gum Rosin has a faint piny odour
→ It is a solid and is vitreous
→ It is semi-transparent or translucent
→ It is brittle at room temperature, melts at higher temperatures
→ Gum Rosin is insoluble in water & soluble in organic solvents
→ The Indonesian Gum rosin is yellowish, while generally gum rosins vary in colour from pale yellow to black.

Production of Gum Rosin

Gum Rosin is produced from the crude pine resin collected from pine trees. The resin is subjected to distillation and the distillation process is carried out in large copper stills. The volatile liquid terpene components separates from the mixture, as it vaporizes at a temperature between 100 to 160⁰C, leaving behind fluid rosin as the distillate. This fluid rosin is collected from below and purified by passing it through straining wadding.The condensate left behind is called turpentine oil.

  

Gum rosin has various applications across a number of industries, some of the important applications are as follows:

Rubber Industry

Gum rosin is used in rubber industry as softening agent. It increases the elasticity of rubber enabling the easy kneading and extrusion. It is also used as an emulsifier in production of various kinds of synthetic rubber like SBR, ABR and chloroperene rubber.

Paper Industry

It is used in the manufacturing of paper for paper sizing, improving the strength of the paper and its smoothness.

Adhesive Industry

Gum rosin is added to adhesives as a binder. They are generally used in rubber-based adhesive processing, hot-melt adhesive processing and pressure-sensitive adhesive processing.

Paint Industry

It is used in oil paints as Gum Rosin can easily be softened and oxidised.It is also present in varnishes.It is present in varnishes.

Pharmaceutical Industry

Gum Rosin is used for tablet film and enteric coating as it has excellent film forming and coating properties. It is used for formulating microcapsules and nanoparticles.Its esters are used in chewing gums for medicinal applications.

Entertainment Industry

Musicians who use string instruments rub gum rosin on their bow strings for the strings to vibrate clearly.In archery, gum rosin is present in the wax that is applied to the bowstring for maintenance purposes.Ballet dancers, boxers, gymnasts and rock climbers apply gum rosin to the tips and heels of their shoes to reduce slippage.

Other applications

Gum rosin is added to printing inks and as a ingredient in laser printing paper. It is also used in thermoplastic coatings and for sealing wax.

PRODUCT IDENTIFICATION
CAS NO. 8050-09-7
EINECS NO. 232-475-7
FORMULA Mixture
TOXICITY Oral rat LD50: 3.0 mg/kg
SYNONYMS Colophony; Rosin, Gum; Pine rosin; Mixture of resin acids;
PHYSICAL AND CHEMICAL PROPERTIES
PHYSICAL STATE yellow crystalline solid
MELTING POINT 70 - 80 C
BOILING POINT 250 C
SPECIFIC GRAVITY 1.06 - 1.08
SOLUBILITY IN WATER Negligible
NFPA RATINGS Health: 2; Flammability: 1; Reactivity: 0
STABILITY Stable under ordinary conditions.
SALES SPECIFICATION
APPEARANCE light yellow
MELTING POINT 76 C min
ACIDITY 166 min (mg KOH/g)
UN SAP VALUE 5.0% max
INSOLUBLES 0.05% max (in alcohol)
ASH 0.02% max