METHOD OF PREPARING COLOPHONY-TERPENE-MALEIC RESIN Russian patent published in 1998 - IPC

FIELD: wood- chemical industry. SUBSTANCE: resin finding application in electronic, electrical, paint and varnish, and other industries is prepared by treating solution of pine pitch in oleo-resin, extraction, or sulfate terpentine at weight ratio (0.6-1.4): (1.4-0.6) with maleic anhydride in amount 33.5-62.5 wt % at 165-175 C in presence of catalyst selected from the group including potassium iodide, sodium iodide, methyl iodide, and calcium iodide in amount 0.03-0.5 wt % followed by stripping off terpentine. Characteristics of resin obtained: softening temperature 66-75 C and acid number 271-287 mg KOH/g. Yield of resin is 80-95%. EFFECT: improved preparation procedure. 2 tbl