PROCESS FOR THE PREPARATION OF BIS-DIAZO COMPOUNDS, PROCESS FOR DYING OR STAMPING CELLULOSE FIBER MATERIALS AND PROCESS FOR THE PREPARATION OF HELIOGRAPHIC COPIES

摘要

bis-Diazo compounds of the formula (1) IMAGE in which R is a straight-chain or branched alkyl or alkoxyalkyl radical of 3 to 5 carbon atoms and Y is an anti-diazotate radical -N=N-O-ME+, in which ME represents a potassium atom or sodium atom, or is the radical -N=N-Z, in which Z represents the radical of a water-soluble aliphatic or aromatic amine containing a sulpho and/or carboxyl group are prepared by bisdiazotising a diamine of the formula (2) IMAGE in which R has the abovementioned meaning in an aqueous, strong, non-oxidising inorganic or organic acid with an alkali metal nitrite at temperatures of about -10 DEG C to about +40 DEG C and converting the bisdiazonium compound formed either into the anti-bisdiazotate of the formula (1) mentioned where Y is -N=N-O-ME+ or into a bisdiazoamino compound of the formula (1) where Y is -N=N-Z in a manner known per se, followed by precipitation.