METHOD OF ISOLATION OF 2,4-DICHLOROPHENOXYACETIC ACID Russian patent published in 1999 - IPC

FIELD: chemical technology, organic synthesis. SUBSTANCE: invention relates to a method of isolation of 2,4-D-acid. The condensed mass of 2,4-D sodium salt is acidified to pH = 4.5-5.5, chlorophenols are extracted with a solvent, an aqueous-saline solution is acidified to pH = 1 and converted to the melt of 2,4-D-acid at stirring and heating. Then 0.04-0.1 wt.-% of surface-active substance is added and the melt of 2,4-D-acid is converted to granules (size is 3 000 x 2 000 mc) at stirring and cooling at the rate 1-5 C/min. EFFECT: improved method of isolation, high quality of the end product, absence of caking at the storage, good yield. 9 ex