Coumarone-Indene Resins

synthetic resins of low molecular weight produced by polymerization of mixtures of unsaturated compounds (primarily indene and coumarone), which have been extracted from the by-products of coal coking (crude benzene) and from the aromatic high-boiling products of petroleum pyrolysis. Fractions containing about 30 percent indene, 15 percent coumarone, and 5 percent styrene are used in the manufacture of coumarone-indene resins. The monomer mixture is polymerized in the presence of boron fluoride, aluminum chloride, or sulfuric acid. Various types of coumaroneindene resins are produced, ranging in color from bright yellow to dark brown and with a melting point between 60° and 140°C. The world annual supply of raw material for coumaroneindene resins is as high as 120,000–150,000 tons.

Coumarone-indene resins are used in the manufacture of resin slabs for floors, linoleum, glues, adhesive insulating tape, artificial leather, and printer's ink. They also serve as plasticizers in certain types of rubber, as a binder in the manufacture of abrasive tools, and as impregnation for paper and textiles to ensure water resistance. Expensive natural resins are replaced by coumarone-indene resins in the preparation of paint and varnish materials.