PROCEDURE FOR SYNTHESIS OF TETRAMETHYLTHIURAM DISULFIDE (TMTD) USING APPROPRIATE REACTION MEDIUM

摘要

The invention herewith described refers to the new procedure for obtaining tetramethylthiuram disulfide (TMTD) the accelerator in rubber vulcanization of the general formula (I)is characterized according to this invention by the fact that: dimethylamine salt of the dimethyldithiocarbamic acid (II)obtained in the reaction of carbon disulphide (III)CS2and dimethylamine (IV)in the suitable reaction medium an azeotropic mixture of isopropyl alcohol - water 87,7% -12,3%, or a mixture of isopropyl alcohol - water 70,4% - 29,6%, is oxidized by hydrogen peroxide (V)H2O2which is also used as a 13,2% solution in azeotropic mixture of isopropyl alcohol - water 87,7% - 12,3%, whereat after the reaction, there is separated the product resulting from the suspension caused by filtration and rinsing, and after that by drying the filtrated slop in the vacuum drier. In the first phase of the reaction, dimethylamine and carbon disulphide react with the most suitable molar ratio 1,0:1,1 at the temperature of 28° C to 35° C for half an hour, while in the second phase, the obtained dimethylamine salt of dimethyldithiocarbamic acid reacts with hydrogen peroxide solution during half an hour, with molar ratio 1,0:1,0 at the temperature of 350 to 400 C. Tetramethylthiuram disulfide (TMTD) is obtained as, the best from the point of the reactor productivity, the 20% suspension which is then filtered by a vacuum filter and rinsed with water, the filtrate is gathered and reused for the next synthesis as the reaction medium, and the filtrated slop is dried in the vacuum drier at the temperature of 80° C and the vacuum of 660 Pa for 2 hours. The obtained (TMTD) can be grinded to the specific granulation and formulated with 1% of the oil for the rubber industry or formulated as the preparation - fungicide.