METHOD OF SYNTHESIS OF POLYVINYL CHLORIDE PLASTICIZER Russian patent published in 1996 - IPC

FIELD: chemical technology. SUBSTANCE: product: mixed esters of o-phthalic acid, ignition point is 180-200 C. Reagent 1: phthalic anhydride. Reagent 2: monohydric aliphatic alcohol of normal or isostructure of the formula C_nH_2n+1OH where n = 4-20, or their mixture. Process conditions: at heating in the presence of catalyst - tetrabutoxytitanium. Alcohols were added by turns at their molar ratio = 1:(1.1-1.4). After addition of the first alcohol or alcohol mixture at mole ratio to phthalic anhydride = 1:1.1 reaction mixture is kept at 140-150 C for 15-30 min; then the second alcohol of the formula C_nH_2n+1OH where n is equal or above 10 or mixture of similar alcohols were added and heated at 140-250 C under residual pressure 200-600 mm mercury column. EFFECT: improved method of synthesis.