Evonik Fibres Gmbh

Evonik Operations Gmbh

Harald Rögl

Markus Ungerank

Oliver Conradi

Artjom Maljusch

Gianluigi Luppi

The present invention provides compounds, especially polymeric compounds, having preferably at least one spiro or piperidine structural unit, a process for preparation thereof and the use thereof as anion conducting membrane.

Polymeric anion-conducting membrane

The present invention provides compounds, especially polymeric compounds, having at least one imidazole and/or imidazolium structural unit, a process for preparation thereof and for the use thereof.

In a method for oxidizing 1,1-bis-(3,4-dimethylphenyl)-alkane with nitric acid in a pressure vessel to produce 3,3',4,4&#x2032;-benzophenone tetracarboxylic acid with concurrent formation of nitric oxide, passing nitric oxide from the pressure vessel into an absorption vessel and reacting nitric oxide in the absorption vessel with molecular oxygen and water to produce an aqueous nitric acid solution prevents discharge of nitric oxide, avoids the risk of oxygen inhibiting the nitric acid oxidation and reduces nitric acid consumption when the nitric acid from the absorption vessel is used for oxidizing the 1,1-bis-(3,4-dimethylphenyl)-alkane.

Method for oxidizing a 1,1,-bis-(3,4-dimethylphenyl)-alkane to 3,3',4,4&#x2032;-benzophenone tetracarboxylic acid

The invention describes a process for preparing pulverulent polyimide-polyimide block copolymers. The result polyimide-polyimide block copolymers and compounds produced using them can be compressed into moldings by the direct forming method or by the hot compression molding method. Polymeric moldings can be produced therefrom by customary mechanical and thermal machining and forming methods.

Process for preparing a block copolymer from polyimides and use of the block copolymer for producing powders and mouldings

Process for preparing 4,4'-difluorobenzophenone, characterized in that, in a first step, fluorobenzene is reacted with formaldehyde under catalysis by organic sulphonic acids to give difluorodiphenylmethane, the product obtained is isolated, and, in a second step, oxidized with nitric acid to give 4,4&#x2032;-difluorobenzophenone. 4,4&#x2032;-Difluorobenzophenone (4,4&#x2032;-DFBP) is the central starting material for the preparation of aromatic polyether ketones.

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Wallern an der, Austria

Harald Rögl