Siemens Aktiengesellschaft

Reinhold Tussing

Wolfgang Von Gentzkow

Manfred Schmiedel

The invention relates to a method and apparatus for the manufacture of N,N'-bis-(aroyl)hydrazines from hydrazine and arylcarboxylic acid alkyl esters in the presence of catalysts. According to the invention, the reaction ingredients are reacted in a substantially stoichiometric mass ratio in an inert medium of low volatility which is liquid to wax-like under reaction conditions, in a suitable reactor equipped with a centrifugal disc and connected to a cycling, separating and draining-off system and a dispersion head to form a paste-like product. The paste-like compound can be used as a metal deactivator in polyolefin which is in direct contact with copper, for instance, in cable and wire insulation.

Method and apparatus for the manufacture of N,N'-bis-(aroyl)hydrazines

As an additive in dyeing and marking agents, 0.5 to 20% by weight of an alkali alcoholate, particularly the sodium or potassium salt of tertiary butanol, is used. The dyeing and marking agents have high contrast (PSC-value greater than 0.8) and have no corrosive action. The agents are particularly suitable as the recording liquid in printers and ink jet recorders.

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Redwitz, Germany

Reinhold Tussing