Rhone-Poulenc Industries

Rhone-Progil

Pierre Bouy

Michel Juillard

Jean Bachot

Dominique Ravier

Michel Conan

Jean-Luc Bourgeois

Hubert De Lachaux

Guy Cheradame

Electrodes for electrolysis are provided comprising a valve-metal substrate and having an active surface which does not employ precious metals, said active surface comprising cobalt oxide and an oxygen or hydrogen compound of titanium in which said titanium has a valence less than 3. The electrode is particularly useful as anode in the electrolysis of sodium chloride.

Electrode for electrolysis

A novel diaphragm suitable for use in electrolytic cells and a novel method of making the diaphragms are provided. The diaphragm according to the invention is characterized in that a reinforcing element is associated with a microporous membrane by integrating it with the anode face of the said membrane. The novel diaphragms are particularly suitable for use in the electrolysis of alkali chlorides.

Method of making porous plastic diaphragms and the resulting novel

A selective composite diaphragm is provided comprising a ion-exchange membrane having at least one microporous layer joined to it, whereby the microporous layer is of high, homogeneous porosity and is preferably at least as thick as the membrane. Said diaphragm is particularly useful for electrolysis of sodium chloride, enabling pure concentrated alkaline solution to be obtained with a high yield.

Selective diaphragm for electrolysis

An inexpensive anode coating for an electrolytic cell, having an outstanding stability and causing only a slight over-voltage, is provided. This anode coating is deposited on a valve metal and comprises a composition of cobalt oxide and titanium bronze, having the insertion of an alkali metal. The coating anode is useful in the electrolysis of alkali halides.

Coated anode

Electrolysis cell having bipolar elements arranged side by side are characterized by an assembly of modules, the cohesion of which is ensured by assembly means from module to module. The cell can be applied in particular to the electrolysis of solutions of alkali salts.

Electrolysis cell of modular structure and having bipolar elements

An improved electrode for an electrolysis cell, and the process for producing the same, are provided whereby there is deposited on a film-forming or barrier metal substrate, a compound of perovskite structure whereby the compound of perovskite structure is suspended in a solution of a cobalt salt which, by thermolysis, is converted to a cobalt oxide, and finally subjecting the resulting composite to a heating treatment.

Electrolysis cell electrode and method of preparation

A novel cloth comprising asbestos fibers, particularly in the form of a micro-porous membrane is provided and a method of obtaining this cloth. It is characterized in that said cloth is obtained by the dry mixing of asbestos fibers and at least one filler or charge substance, then working up by malaxation in the presence of a latex, forming the cloth and, optionally, elimination of the filler substance. The invention is particularly applicable in the production of a micro-porous membrane for use in electrolysis diaphragms.

Cloth comprising asbestos fibers and method of producing said cloth

The invention relates to an electrolysis cell having bipolar elements, characterized in that the recess between the bipolar elements and the impermeability between any two consecutive electrode frames are ensured by the peripheral surfaces opposite the said frames which have, on their most external part, a non-deformable rigid face forming a plane of contact resting against the plane of contact of the adjacent frame. At least one of the opposing surfaces has at least one recess in which at least one sealing member is arranged. The cell is particularly useful for the electrolysis of solutions of alkali salts.

Electrolysis cell having bipolar elements

A novel electrode for an electrolytic cell is provided which electrode is characterized in that it comprises at least one compound of perovskite structure, of the general formula:

Novel electrode for electrolysis cell

A method of obtaining a micro-porous membrane is provided as well as the improved membrane. Said method is characterized in that a homogeneous paste is prepared from a pore-forming filler substance and a latex, and said paste, which is reduced to powder form, is dried and a membrane is formed therefrom and then (fritted) sintered, and the pore-forming filler substance is then removed. The membrane thus obtained is particularly useful as a diaphragm for electrolysis cells.

Method of obtaining a micro-porous membrane and novel product thus

Bipolar electrodes are provided for electrolysis cells of the filter-press type with incorporated cathode and/or anode frames. These frames are integrated in the bimetallic base plate of the electrode serving as reference plane, perpendicularity with respect to said plane being assured with respect to the cathode and anode portions by the current leads to which they are welded, these current leads serving as stiffeners and resulting in the planarity of these electrode portions and their parallelism with respect to the reference plane formed by the bimetallic base plate. These electrodes are highly efficient in the electrolysis of alkaline chlorides.

Bipolar electrodes with incorporated frames

A uniform, porous, homogeneous diaphragm for use in electrolysis cells is provided by bringing together a homogeneous, stable suspension of asbestos fibers in water and a fluorinated polymeric resin latex with a pore-forming agent in the presence of a sulfonated anionic surfactant, the resulting suspension being shaped to the desired form of the diaphragm by filtration, the desired shape of the diaphragm then being dried and sintered at a temperature above the crystalline melting point of the fluorinated polymeric resin, the pore-forming agent finally being removed from the resulting diaphragm by decomposition or extraction.

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Enghien les Bains, France

Pierre Bouy