METHOD FOR OBTAINING A DIOXYLTEREPHTHALATE PLASTIFFICATOR FROM 2-ETHYLHEXANOL AND TECHNICAL TEREPHTHALIC ACID DISTILLATION RESIDUE Russian patent published in 2018 - IPC C07C69/82 C07C67/08 C08K5/12 

FIELD: technological processes.

SUBSTANCE: invention relates to a process for the preparation of a plasticizer for polymeric materials from secondary processing products such as 2-ethylhexanol distillation residue (EDR) and terephthalic acid production waste (TAPW). Proposed plasticizer dioctyl terephthalate (DOTP) is a mixture of esters derived from a mixture of alcohols isolated by distillation from EDR and technical terephthalic acid. Main component of the mixture of alcohols is 2-ethylhexanol. Process for the preparation of the dioctyl terephthalate plasticizer from the bottoms of the distillations of 2-ethylhexanol and technical terephthalic acid includes distilling the EDR, synthesis of the plasticizer of DOTP from 2-ethylhexanol and technical terephthalic acid using a tetrabutoxy titanium catalyst, the 2-ethylhexanol fraction being separated from the EDR by aqueous azeotropic distillation at a column top temperature of 99.1 to 99.44 °C and column temperature 100–102 °C, at the optimum reflux ratio of 0.5, after azeotropic rectification, a fraction of wet 2-ethylhexanol is charged along with technical terephthalic acid containing water up to 50 % in a molar ratio of 3.5–5.5:1, the azeotrope is distilled off, then the tetrabutoxytitanium catalyst is added from 0.3 to 0.6 % by weight. from the reaction mass, for the purpose of esterification, when the synthesis is stopped, water is charged into the reactor to form an aqueous azeotrope and excess 2-EH is distilled off.

EFFECT: technical problem of the invention consists in the preparation of plasticizer DOTF for the production of PVC, consisting of esters derived from 2-ethylhexanol of purity of not less than 72 %, isolated from the bottoms of EDR by aqueous azeotropic rectification and technical terephthalic acid (TTPA) – a waste product of terephthalic acid, which significantly expands the raw material source of plasticizers.

1 cl, 3 dwg, 3 ex