| abstract |
Process for the production of 4,4'-dinitrostilbene disulfonic acid-2,2n'and / or a salt thereof of the formula shownnin the drawing, where M is a hydrogen atom or an alkali metal cation by oxidationnwith air of p-nitrotoluenesulfonic acid-2nin an aqueous, alkaline environment, possiblynin the presence of a catalyst, with possible separationn4,4'-dinitrostilbene disulfonic acid salt-2,2 ',ncharacterized in that the oxidation is carried outnin an alkaline environment with oxygen from the air with the mass transfer coefficient k ^ within the limitsn0.1-0.01 s-, preferably 0.05 s "", whilenin the final phase of the oxidation process, the amount of supplied air changes, keeping the mass transfer coefficient kLa within the range of 0.01 -n0.001 sec'1, use 0.005 sec'1, then the salt of 4,4'-dinitrostilbene disulfonic acid-2,2 'is isolated in a known manner |