EP0707095A1 - Electrode for electrochemical processes and use thereof - Google Patents

Electrode for electrochemical processes and use thereof Download PDF

Info

Publication number
EP0707095A1
EP0707095A1 EP95202666A EP95202666A EP0707095A1 EP 0707095 A1 EP0707095 A1 EP 0707095A1 EP 95202666 A EP95202666 A EP 95202666A EP 95202666 A EP95202666 A EP 95202666A EP 0707095 A1 EP0707095 A1 EP 0707095A1
Authority
EP
European Patent Office
Prior art keywords
coating
platinum
oxide
electrode
iridium
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP95202666A
Other languages
German (de)
French (fr)
Other versions
EP0707095B1 (en
Inventor
Alessandra Pastacaldi
Francesco Posar
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Solvay SA
Original Assignee
Solvay SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Solvay SA filed Critical Solvay SA
Publication of EP0707095A1 publication Critical patent/EP0707095A1/en
Application granted granted Critical
Publication of EP0707095B1 publication Critical patent/EP0707095B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • CCHEMISTRY; METALLURGY
    • C25ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25BELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B11/00Electrodes; Manufacture thereof not otherwise provided for
    • C25B11/04Electrodes; Manufacture thereof not otherwise provided for characterised by the material
    • C25B11/051Electrodes formed of electrocatalysts on a substrate or carrier
    • C25B11/073Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material
    • C25B11/091Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material consisting of at least one catalytic element and at least one catalytic compound; consisting of two or more catalytic elements or catalytic compounds
    • C25B11/093Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material consisting of at least one catalytic element and at least one catalytic compound; consisting of two or more catalytic elements or catalytic compounds at least one noble metal or noble metal oxide and at least one non-noble metal oxide

Definitions

  • the invention relates to electrochemical processes, in particular electrolysis processes.
  • It relates more particularly to an electrode which can be used in such processes.
  • Important parameters of industrial electrolysis processes are, on the one hand, the potentials of electrochemical reactions at the electrodes and, on the other hand, the current efficiency at the electrodes.
  • the difficulty in achieving acceptable current yields is particularly present in the processes of electrolysis of alkali metal salts in aqueous solution, the reaction at the anode usually being accompanied by parasitic oxygen formation. This difficulty is particularly present in the processes for the manufacture of chlorine by electrolysis of aqueous solutions of alkali metal chloride (in particular sodium).
  • anodes comprising, on an electroconductive substrate, a coating of ruthenium oxide and tin oxide, associated with platinum, platinum oxide or iridium oxide.
  • An anode is also mentioned, the coating of which consists of a mixture of 14 mol% of platinum, 6 mol% of iridium and 80 mol% of tin. In this known coating, the iridium and the tin are in the state of oxides.
  • the invention therefore relates to an electrode for an electrochemical process, comprising, on an electroconductive substrate, a coating of platinum, iridium oxide and tin oxide, said coating comprising more than 8% by weight of iridium oxide.
  • the substrate must be made of an electroconductive material, inert under the electrolysis conditions for which the electrode is intended. Notwithstanding this condition, the substrate of the electrode according to the invention is not critical and its constitution does not constitute the object of the invention.
  • the substrate can advantageously be made of a metal selected from titanium, tantalum, zirconium, vanadium, niobium and tungsten or an alloy of these metals.
  • the substrate of the electrode according to the invention can be a solid or perforated, rigid or flexible plate, a wire, a lattice of interlaced wires or a stack of beads.
  • the coating must be present on the substrate in an amount sufficient to cover a substantial part of the substrate and to catalyze the electrochemical reaction for which the electrode is intended.
  • the optimum amount of coating will therefore depend on the electrochemical reaction for which the electrode is intended and it can be determined in each particular case by routine laboratory work.
  • it is desirable that the coating is present on the substrate in an amount at least equal to 1 g (preferably 5 g) per m2 of the surface of the substrate to which it is applied.
  • 1 g preferably 5 g
  • the thicknesses of 8 to 12 g / m2 being specially recommended.
  • the platinum, the iridium oxide and the tin oxide are preferably distributed homogeneously in the coating.
  • this expression is meant that the relative concentrations of platinum, iridium oxide and tin oxide are substantially identical at all coating points or that they do not diverge by more than 5% (preferably 1 %) between any two points of the coating.
  • thermodecomposable compounds of platinum, iridium and tin and then subjecting the coating to a heat treatment in an oxidizing atmosphere, so as to decompose the thermodecomposable compounds and to form the coating.
  • the thermally decomposable compounds can be any compound which, when heated in an oxidizing atmosphere, releases platinum or platinum oxide, iridium dioxide and tin dioxide. They can for example be selected from nitrates, sulfates, phosphates, halides and salts of carboxylic acids.
  • the aforementioned heat-decomposable compounds can be used in the solid state, for example in the form of a powder, or in the liquid state, for example in the form of molten salts, of suspensions or solutions.
  • the heat treatment consists, by definition, of heating the coating to a sufficient temperature in a controlled oxidizing atmosphere to decompose the thermo-decomposable compounds and coprecipitate platinum or platinum oxide, iridium oxide and l 'tin oxide.
  • the oxidizing atmosphere can consist of atmospheric air, enriched air or pure oxygen. We prefer to use atmospheric air.
  • the choice of thermally decomposable compounds and the temperature of the heat treatment are interdependent.
  • thermally decomposable compounds are selected from the halides and these are used in the dissolved state in an organic solvent.
  • Chlorides are preferred, in particular iridium tetrachloride, tin tetrachloride and hexachloroplatinic acid
  • the organic solvent is advantageously selected from alcohols, preferably aliphatic alcohols such as methanol, ethanol and the like. isopropanol, for example.
  • temperatures from 100 to 1000 ° C are suitable in the majority of cases, those from 200 to 750 ° C being especially recommended.
  • the selection of an iridium oxide content greater than 8% (preferably at least equal to 25%) of the weight of the coating makes it possible to substantially increase the discharge overvoltage of the oxygen anions, when the electrode according to the invention is used as an anode in a process for the electrolysis of an aqueous solution of an alkali metal salt, in particular of sodium chloride.
  • the platinum content of the coating is at least 10% (preferably at least 12%) by weight.
  • This embodiment of the electrode according to the invention has the additional advantage of having a lower overvoltage on the electrochemical discharge of chloride anions and it is therefore specially adapted to serve as anode in the electrolytic manufacturing processes of chlorine.
  • the coating of the electrode may consist exclusively of platinum, iridium oxide and tin oxide, or it may comprise one or more additional compounds, different from platinum, iridium oxide and tin oxide. In general it is preferred that the coating of the electrode according to the invention consists essentially of platinum, iridium oxide and tin oxide.
  • the coating of the electrode essentially consists of 12 to 17% by weight of platinum, from 30 to 40% by weight of iridium oxide and from 43 to 58% in weight of tin oxide.
  • the electrode according to this embodiment of the invention is especially suitable as an anode for the production of chlorine by electrolysis of aqueous solutions of chloride of alkali metals.
  • the invention therefore also relates to the use of the electrode according to the invention as an anode in the processes for electrolysis of alkali metal salts in aqueous solution, especially for the production of chlorine by electrolysis of aqueous solutions of metal chloride alkaline. It especially relates to the use of the electrode according to the invention as an anode for the production of chlorine by electrolysis of an aqueous solution of sodium chloride.
  • electrodes were prepared comprising a titanium substrate and a coating of platinum, iridium oxide and tin oxide on the substrate.
  • the substrate consisted of a lattice in the form of a disc of approximately 100 cm 2 in area and the coating was applied to the entire area of the disc.
  • three separate organic solutions were first prepared, namely a solution of hexachloroplatinic acid in isopropanol (30 g of hexachloroplatinic acid per liter of solution), a solution of iridium tetrachloride in isopropanol (20 g of iridium tetrachloride per liter of solution) and a solution of tin tetrachloride in isopropanol (23 g of tin tetrachloride per liter of solution).
  • the three solutions were then mixed in adequate proportions to form the coating and it was then applied to the disc in ten successive layers. After each layer of plaster, the disc and the plaster were heated in atmospheric air, at a temperature of 450 ° C for one hour.
  • the electrodes obtained in the manner described above were used as anodes in a laboratory electrolysis cell, the cathode of which consisted of a 100 cm2 nickel disc, separated from the anode by a membrane of NAFION® brand. (DU PONT), selectively permeable to cations.
  • the distance between the anode and the cathode was set at 1 mm.
  • an appreciably saturated aqueous solution of sodium chloride was electrolysed at 85 ° C., under an anodic current density of 3.5 kA / m2.
  • the anode chamber of the cell was continuously supplied with the sodium chloride solution, so as to produce, in the cathode chamber, an aqueous solution of approximately 32% by weight of hydroxide. sodium. This produced chlorine at the anode and hydrogen at the cathode.
  • the oxygen content in the gas collected at the anode was measured. The results of the measurements have been plotted on the diagram of the appended drawing. On this diagram, the abscissa scale represents time, expressed in days, and the ordinate scale represents the oxygen content in the gas produced at the anode (expressed in% by weight of gas).
  • the solutions of hexachloroplatinic acid, iridium tetrachloride and tin tetrachloride were mixed in adequate proportions so that, after the heat treatment, the coating has the following composition by weight, which is that of the electrode used in Example 13 of patent application EP-A-0153586 cited above: platinum: 17%, iridium dioxide: 8%, tin dioxide: 75%.
  • the solutions of hexachloroplatinic acid, iridium tetrachloride and tin tetrachloride were mixed in suitable proportions so that, after the heat treatment, the coating has the following composition by weight, in accordance with l invention: platinum: 15%, iridium dioxide: 35%, tin dioxide: 50%.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Electrodes For Compound Or Non-Metal Manufacture (AREA)
  • Battery Electrode And Active Subsutance (AREA)
  • Electrolytic Production Of Metals (AREA)
  • Primary Cells (AREA)
  • Secondary Cells (AREA)
  • Electroplating Methods And Accessories (AREA)
  • Other Surface Treatments For Metallic Materials (AREA)
  • Inert Electrodes (AREA)
  • Chemically Coating (AREA)
  • Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)

Abstract

A novel electrode, for electrochemical processes, consists of an electrically conductive substrate bearing a coating of platinum, iridium oxide and tin oxide with an iridium oxide content of more than 8 (pref. at least 25) wt.%. Pref. the coating comprises (by wt.) 12-17% platinum, 30-40% iridium oxide and 53-58% tin oxide.

Description

L'invention concerne les procédés électrochimiques, en particulier les procédés d'électrolyse.The invention relates to electrochemical processes, in particular electrolysis processes.

Elle concerne plus particulièrement une électrode utilisable dans de tels procédés.It relates more particularly to an electrode which can be used in such processes.

Des paramètres importants des procédés d'électrolyse industriels sont, d'une part, les potentiels des réactions électrochimiques aux électrodes et, d'autre part, le rendement de courant aux électrodes.Important parameters of industrial electrolysis processes are, on the one hand, the potentials of electrochemical reactions at the electrodes and, on the other hand, the current efficiency at the electrodes.

La difficulté de réaliser des rendements de courant acceptables est particulièrement présente dans les procédés d'électrolyse des sels des métaux alcalins en solution aqueuse, la réaction à l'anode s'accompagnant habituellement d'une formation parasite d'oxygène. Cette difficulté est particulièrement présente dans les procédés de fabrication de chlore par électrolyse de solutions aqueuses de chlorure de métal alcalin (en particulier de sodium).The difficulty in achieving acceptable current yields is particularly present in the processes of electrolysis of alkali metal salts in aqueous solution, the reaction at the anode usually being accompanied by parasitic oxygen formation. This difficulty is particularly present in the processes for the manufacture of chlorine by electrolysis of aqueous solutions of alkali metal chloride (in particular sodium).

Le moyen utilisé pour réduire la production parasite d'oxygène dans les procédés d'électrolyse consiste à faire usage d'anodes présentant une surtension élevée à l'oxydation des anions d'oxygène. A cet effet, dans la demande de brevet européen EP-A-0153586, on propose des anodes comprenant, sur un substrat électroconducteur, un revêtement d'oxyde de ruthénium et d'oxyde d'étain, associés à du platine, de l'oxyde de platine ou de l'oxyde d'iridium. On cite par ailleurs une anode dont le revêtement consiste en un mélange de 14 % molaire de platine, de 6 % molaire d'iridium et de 80 % molaire d'étain. Dans ce revêtement connu, l'iridium et l'étain sont à l'état d'oxydes.The means used to reduce the parasitic production of oxygen in the electrolysis processes consists in making use of anodes having a high overvoltage to the oxidation of oxygen anions. To this end, in European patent application EP-A-0153586, anodes are proposed comprising, on an electroconductive substrate, a coating of ruthenium oxide and tin oxide, associated with platinum, platinum oxide or iridium oxide. An anode is also mentioned, the coating of which consists of a mixture of 14 mol% of platinum, 6 mol% of iridium and 80 mol% of tin. In this known coating, the iridium and the tin are in the state of oxides.

En ce qui concerne le revêtement connu précité de platine, d'oxyde d'iridium et d'oxyde d'étain, on a maintenant trouvé qu'en modifiant de manière appropriée ses teneurs relatives en platine, oxyde d'iridium et oxyde d'étain, il était possible d'augmenter de manière sensible et inattendue la surtension à l'oxydation des anions d'oxygène et, par voie de conséquence, d'améliorer le rendement de courant anodique dans les procédés d'électrolyse des sels de métaux alcalins en solution aqueuse.With regard to the aforementioned known coating of platinum, iridium oxide and tin oxide, it has now been found that by appropriately modifying its relative contents of platinum, iridium oxide and oxide of tin, it was possible to appreciably and unexpectedly increase the oxidation overvoltage of oxygen anions and, consequently, to improve the anodic current yield in the processes of electrolysis of alkali metal salts in aqueous solution.

L'invention concerne dès lors une électrode pour procédé électrochimique, comprenant, sur un substrat électroconducteur, un revêtement de platine, d'oxyde d'iridium et d'oxyde d'étain, ledit revêtement comprenant plus de 8 % en poids d'oxyde d'iridium.The invention therefore relates to an electrode for an electrochemical process, comprising, on an electroconductive substrate, a coating of platinum, iridium oxide and tin oxide, said coating comprising more than 8% by weight of iridium oxide.

Dans l'électrode selon l'invention, le substrat doit être en un matériau électroconducteur, inerte dans les conditions d'électrolyse auxquelles l'électrode est destinée. Nonobstant cette condition, le substrat de l'électrode selon l'invention n'est pas critique et sa constitution ne constitue pas l'objet de l'invention. A titre d'exemple, le substrat peut avantageusement être en un métal sélectionné parmi le titane, le tantale, le zirconium, le vanadium, le niobium et le tungstène ou en un alliage de ces métaux.In the electrode according to the invention, the substrate must be made of an electroconductive material, inert under the electrolysis conditions for which the electrode is intended. Notwithstanding this condition, the substrate of the electrode according to the invention is not critical and its constitution does not constitute the object of the invention. By way of example, the substrate can advantageously be made of a metal selected from titanium, tantalum, zirconium, vanadium, niobium and tungsten or an alloy of these metals.

Le profil du substrat n'est pas critique et ne constitue pas l'objet de l'invention, le profil le plus adéquat dépendant de la destination de l'électrode et devant dès lors être déterminé dans chaque cas particulier. A titre d'exemple, le substrat de l'électrode selon l'invention peut être une plaque pleine ou ajourée, rigide ou flexible, un fil, un treillis de fils entrelacés ou un empilage de billes.The profile of the substrate is not critical and does not constitute the object of the invention, the most suitable profile depending on the destination of the electrode and must therefore be determined in each particular case. By way of example, the substrate of the electrode according to the invention can be a solid or perforated, rigid or flexible plate, a wire, a lattice of interlaced wires or a stack of beads.

Le revêtement doit être présent sur le substrat en une quantité suffisante pour couvrir une partie substantielle du substrat et catalyser la réaction électrochimique à laquelle l'électrode est destinée. La quantité optimum de revêtement va dès lors dépendre de la réaction électrochimique à laquelle on destine l'électrode et elle peut être déterminée dans chaque cas particulier par un travail de routine au laboratoire. En pratique, il est souhaitable que le revêtement soit présent sur le substrat en une quantité au moins égale à 1 g (de préférence à 5 g) par m² de la surface du substrat sur laquelle il est appliqué. Bien qu'il n'existe pas, en principe, de limite supérieure à l'épaisseur du revêtement sur le substrat, en pratique il n'y a pas intérêt à ce qu'il excède 20 g par m² de la surface précitée du substrat, les épaisseurs de 8 à 12 g/m² étant spécialement recommandées.The coating must be present on the substrate in an amount sufficient to cover a substantial part of the substrate and to catalyze the electrochemical reaction for which the electrode is intended. The optimum amount of coating will therefore depend on the electrochemical reaction for which the electrode is intended and it can be determined in each particular case by routine laboratory work. In practice, it is desirable that the coating is present on the substrate in an amount at least equal to 1 g (preferably 5 g) per m² of the surface of the substrate to which it is applied. Although there is, in principle, no upper limit to the thickness of the coating on the substrate, in practice there is no point in it exceeding 20 g per m² of the aforementioned surface of the substrate , the thicknesses of 8 to 12 g / m² being specially recommended.

Dans l'électrode selon l'invention, le platine, l'oxyde d'iridium et l'oxyde d'étain sont de préférence répartis de manière homogène dans le revêtement. On entend par cette expression, que les concentrations relatives de platine, d'oxyde d'iridium et d'oxyde d'étain sont sensiblement identiques en tous points de revêtement ou qu'elles ne divergent pas de plus de 5 % (de préférence 1 %) entre deux points quelconque du revêtement.In the electrode according to the invention, the platinum, the iridium oxide and the tin oxide are preferably distributed homogeneously in the coating. By this expression is meant that the relative concentrations of platinum, iridium oxide and tin oxide are substantially identical at all coating points or that they do not diverge by more than 5% (preferably 1 %) between any two points of the coating.

Tous moyens appropriés peuvent être utilisés pour appliquer le revêtement sur le substrat. Un moyen recommandé consiste à appliquer sur le substrat un enduit de composés thermodécomposables du platine, de l'iridium et de l'étain et à soumettre ensuite l'enduit à un traitement thermique en atmosphère oxydante, de manière à décomposer les composés thermodécomposables et à former le revêtement. Les composés thermodécomposables peuvent être tous composés qui, chauffés en atmosphère oxydante, libèrent du platine ou de l'oxyde de platine, du dioxyde d'iridium et du dioxyde d'étain. Ils peuvent par exemple être sélectionnés parmi les nitrates, les sulfates, les phosphates, les halogénures et les sels d'acides carboxyliques. Pour constituer l'enduit, les composés thermodécomposables précités peuvent être mis en oeuvre à l'état solide, par exemple à l'état d'une poudre, ou à l'état liquide, par exemple sous la forme de sels fondus, de suspensions ou de solutions. Le traitement thermique consiste, par définition, en un chauffage de l'enduit à une température suffisante en atmosphère oxydante contrôlée pour décomposer les composés thermodécomposables et coprécipiter du platine ou de l'oxyde de platine, de l'oxyde d'iridium et de l'oxyde d'étain. L'atmosphère oxydante peut consister en de l'air atmosphérique, de l'air enrichi ou de l'oxygène pur. On préfère utiliser l'air atmosphérique. Le choix des composés thermodécomposables et la température du traitement thermique sont interdépendants. Le choix des composés thermodécomposables est notamment influencé par la température admissible pour le traitement thermique, de manière à éviter que celui-ci endommage le substrat. Dans une forme d'exécution avantageuse de l'invention, les composés thermodécomposables sont sélectionnés parmi les halogénures et ceux-ci sont mis en oeuvre à l'état dissous dans un solvant organique. Les chlorures sont préférés, en particulier le tétrachlorure d'iridium, le tétrachlorure d'étain et l'acide hexachloroplatinique, et le solvant organique est avantageusement sélectionné parmi les alcools, de préférence les alcools aliphatiques tels que le méthanol, l'éthanol et l'isopropanol, par exemple. Pour l'exécution du traitement thermique, les températures de 100 à 1 000 °C conviennent dans la majorité des cas, celles de 200 à 750 °C étant spécialement recommandées. Dans la mise en oeuvre de cette forme d'exécution de l'invention, il est généralement recommandé d'appliquer plusieurs couches successives de la solution organique des composés thermodécomposables sur le substrat et de soumettre chaque couche individuellement au traitement thermique défini plus haut.Any suitable means can be used to apply the coating to the substrate. One recommended way is to apply on the substrate a coating of thermodecomposable compounds of platinum, iridium and tin and then subjecting the coating to a heat treatment in an oxidizing atmosphere, so as to decompose the thermodecomposable compounds and to form the coating. The thermally decomposable compounds can be any compound which, when heated in an oxidizing atmosphere, releases platinum or platinum oxide, iridium dioxide and tin dioxide. They can for example be selected from nitrates, sulfates, phosphates, halides and salts of carboxylic acids. To form the coating, the aforementioned heat-decomposable compounds can be used in the solid state, for example in the form of a powder, or in the liquid state, for example in the form of molten salts, of suspensions or solutions. The heat treatment consists, by definition, of heating the coating to a sufficient temperature in a controlled oxidizing atmosphere to decompose the thermo-decomposable compounds and coprecipitate platinum or platinum oxide, iridium oxide and l 'tin oxide. The oxidizing atmosphere can consist of atmospheric air, enriched air or pure oxygen. We prefer to use atmospheric air. The choice of thermally decomposable compounds and the temperature of the heat treatment are interdependent. The choice of thermally decomposable compounds is notably influenced by the temperature admissible for the heat treatment, so as to prevent the latter from damaging the substrate. In an advantageous embodiment of the invention, the thermally decomposable compounds are selected from the halides and these are used in the dissolved state in an organic solvent. Chlorides are preferred, in particular iridium tetrachloride, tin tetrachloride and hexachloroplatinic acid, and the organic solvent is advantageously selected from alcohols, preferably aliphatic alcohols such as methanol, ethanol and the like. isopropanol, for example. For the execution of the heat treatment, temperatures from 100 to 1000 ° C are suitable in the majority of cases, those from 200 to 750 ° C being especially recommended. In the implementation of this embodiment of the invention, it is generally recommended to apply several successive layers of the organic solution of the thermally decomposable compounds on the substrate and to subject each layer individually to the heat treatment defined above.

Selon l'invention, la sélection d'une teneur en oxyde d'iridium supérieure à 8 % (de préférence au moins égale à 25 %) du poids du revêtement permet d'augmenter de manière substantielle la surtension de décharge des anions oxygène, lorsque l'électrode selon l'invention est utilisée comme anode dans un procédé d'électrolyse d'une solution aqueuse d'un sel de métal alcalin, en particulier de chlorure de sodium.According to the invention, the selection of an iridium oxide content greater than 8% (preferably at least equal to 25%) of the weight of the coating makes it possible to substantially increase the discharge overvoltage of the oxygen anions, when the electrode according to the invention is used as an anode in a process for the electrolysis of an aqueous solution of an alkali metal salt, in particular of sodium chloride.

Dans une forme de réalisation particulière de l'électrode selon l'invention, la teneur en platine du revêtement est d'au moins 10 % (de préférence d'au moins 12 %) en poids. Cette forme de réalisation de l'électrode selon l'invention possède l'avantage supplémentaire de présenter une plus faible surtension à la décharge électrochimique des anions chlorure et elle est de ce fait spécialement adaptée à servir d'anode dans les procédés de fabrication électrolytique de chlore.In a particular embodiment of the electrode according to the invention, the platinum content of the coating is at least 10% (preferably at least 12%) by weight. This embodiment of the electrode according to the invention has the additional advantage of having a lower overvoltage on the electrochemical discharge of chloride anions and it is therefore specially adapted to serve as anode in the electrolytic manufacturing processes of chlorine.

Le revêtement de l'électrode peut être constitué exclusivement de platine, d'oxyde d'iridium et d'oxyde d'étain, ou bien il peut comprendre un ou plusieurs composés additionnels, différents du platine, de l'oxyde d'iridium et de l'oxyde d'étain. En général on préfère que le revêtement de l'électrode selon l'invention soit essentiellement constitué de platine, d'oxyde d'iridium et d'oxyde d'étain.The coating of the electrode may consist exclusively of platinum, iridium oxide and tin oxide, or it may comprise one or more additional compounds, different from platinum, iridium oxide and tin oxide. In general it is preferred that the coating of the electrode according to the invention consists essentially of platinum, iridium oxide and tin oxide.

Selon une forme de réalisation préférée de l'invention, le revêtement de l'électrode est essentiellement constitué de 12 à 17 % en poids de platine, de 30 à 40 % en poids d'oxyde d'iridium et de 43 à 58 % en poids d'oxyde d'étain. L'électrode conforme à cette forme de réalisation de l'invention convient spécialement bien comme anode pour la production de chlore par électrolyse des solutions aqueuses de chlorure des métaux alcalins.According to a preferred embodiment of the invention, the coating of the electrode essentially consists of 12 to 17% by weight of platinum, from 30 to 40% by weight of iridium oxide and from 43 to 58% in weight of tin oxide. The electrode according to this embodiment of the invention is especially suitable as an anode for the production of chlorine by electrolysis of aqueous solutions of chloride of alkali metals.

L'invention concerne dès lors également l'utilisation de l'électrode selon l'invention comme anode dans les procédés d'électrolyse des sels des métaux alcalins en solution aqueuse, spécialement pour la production de chlore par électrolyse des solutions aqueuses de chlorure des métaux alcalins. Elle concerne tout spécialement l'utilisation de l'électrode selon l'invention comme anode pour la production de chlore par électrolyse d'une solution aqueuse de chlorure de sodium.The invention therefore also relates to the use of the electrode according to the invention as an anode in the processes for electrolysis of alkali metal salts in aqueous solution, especially for the production of chlorine by electrolysis of aqueous solutions of metal chloride alkaline. It especially relates to the use of the electrode according to the invention as an anode for the production of chlorine by electrolysis of an aqueous solution of sodium chloride.

L'intérêt de l'invention va ressortir de la description des exemples suivants, en référence à la figure unique du dessin annexé qui est un diagramme fournissant les performances comparées d'une électrode selon l'invention et d'une électrode antérieure à l'invention.The advantage of the invention will become apparent from the description of the following examples, with reference to the single figure of the appended drawing which is a diagram providing the compared performances of an electrode according to the invention and an electrode prior to the invention.

Dans les exemples dont la description suit, on a préparé des électrodes comprenant un substrat en titane et un revêtement de platine, d'oxyde d'iridium et d'oxyde d'étain sur le substrat. Le substrat a consisté en un treillis ayant la forme d'un disque d'environ 100 cm² de superficie et le revêtement a été appliqué sur la totalité de la superficie du disque. Pour former le revêtement, on a d'abord préparé trois solutions organiques distinctes, à savoir une solution d'acide hexachloroplatinique dans de l'isopropanol (30 g d'acide hexachloroplatinique par litre de solution), une solution de tétrachlorure d'iridium dans de l'isopropanol (20 g de tétrachlorure d'iridium par litre de solution) et une solution de tétrachlorure d'étain dans de l'isopropanol (23 g de tétrachlorure d'étain par litre de solution). Les trois solutions ont ensuite été mélangées en proportions adéquates pour constituer l'enduit et celui-ci a ensuite été appliqué sur le disque en dix couches successsives. A l'issue de chaque couche d'enduit, le disque et l'enduit ont été chauffés dans l'air atmosphérique, à la température de 450 °C pendant une heure.In the examples whose description follows, electrodes were prepared comprising a titanium substrate and a coating of platinum, iridium oxide and tin oxide on the substrate. The substrate consisted of a lattice in the form of a disc of approximately 100 cm 2 in area and the coating was applied to the entire area of the disc. To form the coating, three separate organic solutions were first prepared, namely a solution of hexachloroplatinic acid in isopropanol (30 g of hexachloroplatinic acid per liter of solution), a solution of iridium tetrachloride in isopropanol (20 g of iridium tetrachloride per liter of solution) and a solution of tin tetrachloride in isopropanol (23 g of tin tetrachloride per liter of solution). The three solutions were then mixed in adequate proportions to form the coating and it was then applied to the disc in ten successive layers. After each layer of plaster, the disc and the plaster were heated in atmospheric air, at a temperature of 450 ° C for one hour.

Les électrodes obtenues de la manière exposée ci-dessus ont été utilisées comme anodes dans une cellule d'électrolyse de laboratoire, dont la cathode a consisté en un disque en nickel de 100 cm², séparé de l'anode par une membrane de marque NAFION® (DU PONT), sélectivement perméable aux cations. La distance entre l'anode et la cathode a été fixée à 1 mm. Pour évaluer les performances de l'anode, on a procédé à l'électrolyse d'une solution aqueuse sensiblement saturée de chlorure de sodium à 85 °C, sous une densité de courant anodique de 3,5 kA/m². A cet effet, pendant l'électrolyse, on a alimenté la chambre anodique de la cellule en permanence avec la solution de chlorure de sodium, de manière à produire, dans la chambre cathodique, une solution aqueuse de 32 % en poids environ d'hydroxyde de sodium. On a de la sorte produit du chlore à l'anode et de l'hydrogène à la cathode. Pour évaluer les performances de l'anode, on a mesuré la teneur en oxygène dans le gaz recueilli à l'anode. Les résultats des mesures ont été portés sur le diagramme du dessin annexé. Sur ce diagramme, l'échelle des abscisses représente le temps, exprimé en jours, et l'échelle des ordonnées représente la teneur en oxygène dans le gaz produit à l'anode (exprimée en % en poids de gaz).The electrodes obtained in the manner described above were used as anodes in a laboratory electrolysis cell, the cathode of which consisted of a 100 cm² nickel disc, separated from the anode by a membrane of NAFION® brand. (DU PONT), selectively permeable to cations. The distance between the anode and the cathode was set at 1 mm. To evaluate the performance of the anode, an appreciably saturated aqueous solution of sodium chloride was electrolysed at 85 ° C., under an anodic current density of 3.5 kA / m². For this purpose, during the electrolysis, the anode chamber of the cell was continuously supplied with the sodium chloride solution, so as to produce, in the cathode chamber, an aqueous solution of approximately 32% by weight of hydroxide. sodium. This produced chlorine at the anode and hydrogen at the cathode. To assess the performance of the anode, the oxygen content in the gas collected at the anode was measured. The results of the measurements have been plotted on the diagram of the appended drawing. On this diagram, the abscissa scale represents time, expressed in days, and the ordinate scale represents the oxygen content in the gas produced at the anode (expressed in% by weight of gas).

Exemple 1 (de référence)Example 1 (for reference)

Dans cet exemple, les solutions d'acide hexachloroplatinique, de tétrachlorure d'iridium et de tétrachlorure d'étain ont été mélangées en proportions adéquates pour qu'à l'issue du traitement thermique, le revêtement présente la composition pondérale suivante, qui est celle de l'électrode utilisée à l'exemple 13 de la demande de brevet EP-A-0153586 citée plus haut : platine : 17 %, dioxyde d'iridium : 8 %, dioxyde d'étain : 75 %. In this example, the solutions of hexachloroplatinic acid, iridium tetrachloride and tin tetrachloride were mixed in adequate proportions so that, after the heat treatment, the coating has the following composition by weight, which is that of the electrode used in Example 13 of patent application EP-A-0153586 cited above: platinum: 17%, iridium dioxide: 8%, tin dioxide: 75%.

L'évolution au cours du temps de la teneur en oxygène dans le gaz recueilli a l'anode est représentée par les symboles ■ au diagramme du dessin.The evolution over time of the oxygen content in the gas collected at the anode is represented by the symbols in the diagram of the drawing.

Exemple 2 (conforme à l'invention)Example 2 (according to the invention)

Dans cet exemple, les solutions d'acide hexachloroplatinique, de tétrachlorure d'iridium et de tétrachlorure d'étain ont été mélangées en proportions adéquates pour qu'à l'issue du traitement thermique, le revêtement présente la composition pondérale suivante, conforme à l'invention : platine : 15 %, dioxyde d'iridium : 35 %, dioxyde d'étain : 50 %. In this example, the solutions of hexachloroplatinic acid, iridium tetrachloride and tin tetrachloride were mixed in suitable proportions so that, after the heat treatment, the coating has the following composition by weight, in accordance with l invention: platinum: 15%, iridium dioxide: 35%, tin dioxide: 50%.

L'évolution au cours du temps de la teneur en oxygène dans le gaz recueilli a l'anode est représentée par les symboles + au diagramme du dessin.The evolution over time of the oxygen content in the gas collected at the anode is represented by the symbols + in the diagram of the drawing.

Une comparaison des résultats des exemples 1 et 2 au diagramme du dessin fait immédiatement apparaître le progrès apporté par l'invention.A comparison of the results of Examples 1 and 2 with the diagram in the drawing immediately shows the progress made by the invention.

Claims (9)

Electrode pour procédé électrochimique, comprenant, sur un substrat électroconducteur, un revêtement de platine, d'oxyde d'iridium et d'oxyde d'étain, ledit revêtement comprenant plus de 8 % en poids d'oxyde d'iridium.Electrode for electrochemical process, comprising, on an electroconductive substrate, a coating of platinum, iridium oxide and tin oxide, said coating comprising more than 8% by weight of iridium oxide. Electrode selon la revendication 1, caractérisée en ce que le revêtement comprend au moins 25 % en poids d'oxyde d'iridium.Electrode according to claim 1, characterized in that the coating comprises at least 25% by weight of iridium oxide. Electrode selon la revendication 1 ou 2, caractérisée en ce que le revêtement comprend au moins 10 % en poids de platine.Electrode according to claim 1 or 2, characterized in that the coating comprises at least 10% by weight of platinum. Electrode selon l'une quelconque des revendications 1 à 3, caractérisée en ce que le revêtement est essentiellement constitué de platine, d'oxyde d'iridium et d'oxyde d'étain.Electrode according to any one of Claims 1 to 3, characterized in that the coating consists essentially of platinum, iridium oxide and tin oxide. Electrode selon la revendication 4, caractérisée en ce que le revêtement comprend de 12 à 17 % en poids de platine, de 30 à 40 % en poids d'oxyde d'iridium et de 43 à 58 % en poids d'oxyde d'étain.Electrode according to claim 4, characterized in that the coating comprises from 12 to 17% by weight of platinum, from 30 to 40% by weight of iridium oxide and from 43 to 58% by weight of tin oxide . Electrode selon l'une quelconque des revendications 1 à 5 caractérisée en ce que le substrat est en un métal sélectionné parmi le titane, le tantale, le zirconium, le vanadium, le niobium et le tungstène ou en un alliage de ces métaux.Electrode according to any one of Claims 1 to 5, characterized in that the substrate is made of a metal selected from titanium, tantalum, zirconium, vanadium, niobium and tungsten or an alloy of these metals. Utilisation de l'électrode selon l'une quelconque des revendications 1 à 6, comme anode dans un procédé d'électrolyse d'un sel de métal alcalin en solution aqueuse.Use of the electrode according to any one of Claims 1 to 6, as an anode in a process for the electrolysis of an alkali metal salt in aqueous solution. Utilisation selon la revendication 7, pour la production de chlore, le sel de métal alcalin étant un chlorure.Use according to claim 7, for the production of chlorine, the alkali metal salt being a chloride. Utilisation selon la revendication 8, dans laquelle le métal alcalin est le sodium.Use according to claim 8, wherein the alkali metal is sodium.
EP95202666A 1994-10-11 1995-10-04 Electrode for electrochemical processes and use thereof Expired - Lifetime EP0707095B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
ITMI942070 1994-10-11
ITMI942070A IT1270649B (en) 1994-10-11 1994-10-11 ELECTRODE FOR AN ELECTROCHEMICAL PROCEDURE AND USE OF THE ELECTRODE

Publications (2)

Publication Number Publication Date
EP0707095A1 true EP0707095A1 (en) 1996-04-17
EP0707095B1 EP0707095B1 (en) 1999-03-31

Family

ID=11369689

Family Applications (1)

Application Number Title Priority Date Filing Date
EP95202666A Expired - Lifetime EP0707095B1 (en) 1994-10-11 1995-10-04 Electrode for electrochemical processes and use thereof

Country Status (11)

Country Link
US (1) US5679225A (en)
EP (1) EP0707095B1 (en)
JP (1) JP3943151B2 (en)
AT (1) ATE178367T1 (en)
BR (1) BR9504362A (en)
CA (1) CA2160221C (en)
DE (1) DE69508689T2 (en)
DK (1) DK0707095T3 (en)
ES (1) ES2131758T3 (en)
IT (1) IT1270649B (en)
PL (1) PL178811B1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2006030685A1 (en) 2004-09-17 2006-03-23 Tama Chemicals Co., Ltd. Electrolysis electrode and method for producing aqueous quaternary ammonium hydroxide solution using such electrolysis electrode

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2716207B1 (en) * 1994-02-15 1996-05-31 Rhone Poulenc Chimie Electroactive material, its preparation and its use for obtaining cathode elements.
US5989396A (en) * 1997-04-02 1999-11-23 Eltech Systems Corporation Electrode and electrolytic cell containing same
US6271131B1 (en) 1998-08-26 2001-08-07 Micron Technology, Inc. Methods for forming rhodium-containing layers such as platinum-rhodium barrier layers
US6284655B1 (en) * 1998-09-03 2001-09-04 Micron Technology, Inc. Method for producing low carbon/oxygen conductive layers
US6323081B1 (en) 1998-09-03 2001-11-27 Micron Technology, Inc. Diffusion barrier layers and methods of forming same
US6239028B1 (en) 1998-09-03 2001-05-29 Micron Technology, Inc. Methods for forming iridium-containing films on substrates
US6329286B1 (en) 1999-04-27 2001-12-11 Micron Technology, Inc. Methods for forming conformal iridium layers on substrates
US6660631B1 (en) 2000-08-31 2003-12-09 Micron Technology, Inc. Devices containing platinum-iridium films and methods of preparing such films and devices
KR20190022333A (en) * 2017-08-23 2019-03-06 주식회사 엘지화학 Anode for electrolysis and preparation method thereof
EP4245890A1 (en) 2020-11-12 2023-09-20 Lg Chem, Ltd. Electrode for electrolysis

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0153586A1 (en) 1984-01-31 1985-09-04 TDK Corporation Electrode for electrolysis
JPS6152385A (en) * 1984-08-17 1986-03-15 Tdk Corp Electrode for electrolyzing diluted aqueous sodium chloride solution
JPS62243790A (en) * 1986-04-15 1987-10-24 Osaka Soda Co Ltd Anode for electrolysis
EP0475914A2 (en) * 1990-09-04 1992-03-18 Permelec Electrode Ltd Anode for chromium plating and processes for producing and using the same

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0121694B1 (en) * 1983-03-11 1986-04-16 BBC Aktiengesellschaft Brown, Boveri & Cie. Catalyst for the coating of anodes, and its manufacturing process

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0153586A1 (en) 1984-01-31 1985-09-04 TDK Corporation Electrode for electrolysis
JPS6152385A (en) * 1984-08-17 1986-03-15 Tdk Corp Electrode for electrolyzing diluted aqueous sodium chloride solution
JPS62243790A (en) * 1986-04-15 1987-10-24 Osaka Soda Co Ltd Anode for electrolysis
EP0475914A2 (en) * 1990-09-04 1992-03-18 Permelec Electrode Ltd Anode for chromium plating and processes for producing and using the same

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
DATABASE WPI Section Ch Week 8617, Derwent World Patents Index; Class E36, AN 86-110049 *
DATABASE WPI Section Ch Week 8748, Derwent World Patents Index; Class E36, AN 87-338698 *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2006030685A1 (en) 2004-09-17 2006-03-23 Tama Chemicals Co., Ltd. Electrolysis electrode and method for producing aqueous quaternary ammonium hydroxide solution using such electrolysis electrode
EP1808512A1 (en) * 2004-09-17 2007-07-18 Tama Chemicals Co., Ltd. Electrolysis electrode and method for producing aqueous quaternary ammonium hydroxide solution using such electrolysis electrode
EP1808512A4 (en) * 2004-09-17 2009-03-04 Tama Chemicals Co Ltd Electrolysis electrode and method for producing aqueous quaternary ammonium hydroxide solution using such electrolysis electrode

Also Published As

Publication number Publication date
DK0707095T3 (en) 1999-10-18
IT1270649B (en) 1997-05-07
ES2131758T3 (en) 1999-08-01
US5679225A (en) 1997-10-21
ATE178367T1 (en) 1999-04-15
CA2160221A1 (en) 1996-04-12
ITMI942070A0 (en) 1994-10-11
ITMI942070A1 (en) 1996-04-11
BR9504362A (en) 1997-09-02
PL310881A1 (en) 1996-04-15
PL178811B1 (en) 2000-06-30
CA2160221C (en) 2007-02-20
DE69508689D1 (en) 1999-05-06
DE69508689T2 (en) 1999-09-30
JPH08176876A (en) 1996-07-09
JP3943151B2 (en) 2007-07-11
EP0707095B1 (en) 1999-03-31

Similar Documents

Publication Publication Date Title
EP1125005B1 (en) Cathode for electrolysing aqueous solutions
EP0479423B1 (en) Electrode
EP0707095B1 (en) Electrode for electrochemical processes and use thereof
HUE028214T2 (en) Cathode for electrolytic processes
CA1158600A (en) Cathode for the production of hydrogen through electrolysis
US7211177B2 (en) Electrode for electrolysis in acidic media
FR2599386A1 (en) SUSTAINABLE ELECTRODES FOR ELECTROLYSIS AND PROCESS FOR THEIR MANUFACTURE
FR2471424A1 (en) LOW HYDROGEN OVERVOLTAGE CATHODES, PRODUCTION FOR THEIR PRODUCTION AND ELECTROLYTIC CELLS COMPRISING THE SAME
JPS6363636B2 (en)
FR2723107A1 (en) PROCESS FOR THE ELECTROLYTIC REDUCTION OF A DISULFIDE AND A PRODUCT THUS OBTAINED
EP0131978B1 (en) Process for manufacturing an electrode for electrochemical processes, and cathode for the electrolytic production of hydrogen
FR2558851A1 (en) PROCESS FOR THE MANUFACTURE OF AN ELECTRODE
EP0344378B1 (en) Oxygen-generating electrode and method for the preparation thereof
EP0867527A1 (en) Electrode with catalytic coating for electrochemical processes and manufacture thereof
EP1608795B1 (en) Method for the formation of a coating of metal oxides on an electrically-conducting substrate, resultant activated cathode and use thereof for the electrolysis of aqueous solutions of alkaline metal chlorides
JPS62243790A (en) Anode for electrolysis
EP0004236B1 (en) Electrode for electrolysis
CA1059067A (en) Electrolysis cell electrode
EP0209427A1 (en) Cathode for electrolysis, and manufacturing process for said cathode
CH633321A5 (en) METHOD FOR PRODUCING ELECTRODES.
US6733652B1 (en) Method for electrolytically converting organic compounds
JP2836890B2 (en) Electrode for organic matter electrolysis and method for producing the same
US4415416A (en) Electrochemical depyrophorization of raney nickel electrodes
EP0425395A1 (en) Hydrogen evolving cathode
JPS62240780A (en) Anode for electrolysis

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB GR IT LI NL PT SE

17P Request for examination filed

Effective date: 19961017

17Q First examination report despatched

Effective date: 19970723

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE CH DE DK ES FR GB GR IT LI NL PT SE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19990331

Ref country code: AT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 19990331

REF Corresponds to:

Ref document number: 178367

Country of ref document: AT

Date of ref document: 19990415

Kind code of ref document: T

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

REF Corresponds to:

Ref document number: 69508689

Country of ref document: DE

Date of ref document: 19990506

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)

Effective date: 19990527

REG Reference to a national code

Ref country code: CH

Ref legal event code: NV

Representative=s name: E. BLUM & CO. PATENTANWAELTE

REG Reference to a national code

Ref country code: ES

Ref legal event code: FG2A

Ref document number: 2131758

Country of ref document: ES

Kind code of ref document: T3

REG Reference to a national code

Ref country code: PT

Ref legal event code: SC4A

Free format text: AVAILABILITY OF NATIONAL TRANSLATION

Effective date: 19990622

REG Reference to a national code

Ref country code: DK

Ref legal event code: T3

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20021002

Year of fee payment: 8

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 20021004

Year of fee payment: 8

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20021008

Year of fee payment: 8

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20021011

Year of fee payment: 8

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DK

Payment date: 20021014

Year of fee payment: 8

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: CH

Payment date: 20021016

Year of fee payment: 8

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 20021031

Year of fee payment: 8

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20031004

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20031005

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20031031

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20031031

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DK

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20040430

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20040501

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20040501

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20031004

EUG Se: european patent has lapsed
REG Reference to a national code

Ref country code: DK

Ref legal event code: EBP

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20040630

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee

Effective date: 20040501

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: PT

Payment date: 20080910

Year of fee payment: 14

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: ES

Payment date: 20081030

Year of fee payment: 14

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: BE

Payment date: 20081010

Year of fee payment: 14

Ref country code: IT

Payment date: 20081029

Year of fee payment: 14

REG Reference to a national code

Ref country code: PT

Ref legal event code: MM4A

Free format text: LAPSE DUE TO NON-PAYMENT OF FEES

Effective date: 20100405

BERE Be: lapsed

Owner name: S.A. *SOLVAY

Effective date: 20091031

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: PT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20100405

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20091031

REG Reference to a national code

Ref country code: ES

Ref legal event code: FD2A

Effective date: 20110324

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20091004

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20110310

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20091005