Hoechst Aktiengesellschaft

Jurgen Cramer

Rudolf Pistorius

Michael Mitzlaff

Gerhard Noltner

Wilfried Schuler

Gerd Reinhardt

Georg Borchers

Erwin Schmidt

Harald Jensen

Helmut Berenbold

Hartmut Pietsch

Klaus Dehmer

Helmut Kramer

Werner Lindner

By Ortwin Alt, Heir

Hartmuth Wilhelm Alt, Deceased

By Gudrun Beyer, Nee Alt, Heir

The present invention relates to a process for the preparation of storage-stable granules essentially comprising a bleaching activator and an inorganic binder material, which comprises the process steps:

Granulated bleaching activators and their preparation

A pulverulant, dry bleach activator, in particular tetraacetylethylenediamine is first moistened with water and then mixed with a dry auxiliary, in particular, with Na carboxymethylcellulose. This mixture is then granulated.

Process for the preparation of a readily soluble bleach activator

Bipolar electrodes of graphite or glassy carbon are provided on the cathode side with metal nets of a material reducing the hydrogen overvoltage, such as nickel, copper, titanium, steel or brass and between the metal nets and the next anode a spacer made of an insulating material is inserted.

Bipolar electrode for anodic processes in undivided cells

N-Vinyl-N-alkyl-carboxylic acid amides are prepared, starting from N-ethyl-carboxylic acid amides, in a 3-stage process consisting of the following stages:

Process for the preparation of N-vinyl-N-alkyl-carboxylic acid amides

N-.alpha.-alkoxyethyl-carboxylic acid amides are prepared by anodic alkoxylation of N-ethyl-carboxylic acid amides with an alcohol in an electrolytic cell using vitreous carbon as anode material and at least one alkali metal and/or tetraalkyl-ammonium alkosulfate as supporting electrolyte.

Process for the manufacture of N-.alpha.-alkoxyethyl-carboxylic acid

Electrochemical, especially organo-electrochemical, reactions are carried out with improved current efficiency in a continuous-flow cell with the use of bipolar electrodes placed in a frame of non-conducting material, especially a polyolefin. Preferably, the electrically active part of the electrodes consists of glass-like carbon the cathode face of which is coated with a material reducing the hydrogen overvoltage, for example titanium carbide or tungsten carbide.

Apparatus for carrying out electrochemical reactions and correspondingly

p-Benzoquinone-diketals of the formual I ##STR1## in which R is H, (C.sub.1 -C.sub.4)-alkyl or halogen, and R.sup.1 is (C.sub.1 -C.sub.4)-alkyl, are prepared by anodic oxidation of benzene or an alkoxybenzene of the formulae ##STR2## in which R and R.sup.1 are as defined for formula I, in methanol containing less than about 5% by weight of water, in th presence of at least one alkali metal fluoride, ammonium fluoride and/or phosphonium fluoride as supporting electrolyte the pH being maintained below 7 by addition of HF. It is especially advantageous to carry out the anodic oxidation in a continuous-flow cell with the use of bipolar electrodes of glass-like carbon wherein the cathode surface is coated with a material reducing the hydrogen overvoltage, preferably titanium carbide.

Process for the manufacture of p-benzoquinone-diketals

A process for the manufacture of phenylhydrazine by cathodic reduction of diazoaminobenzene dissolved in an electrolyte on solid electrodes with separation of cathode and anode spaces by a diaphragm wherein the diazoaminobenzene solution is electrolyzed in a flow type diaphragm cell at a graphite cathode having a three dimensional surface.

Growing community of inventors

Eppstein, Germany

Jurgen Cramer