EP0286499B1 - Pitch for binding electrodes and process for preparing said pitch - Google Patents

Pitch for binding electrodes and process for preparing said pitch Download PDF

Info

Publication number
EP0286499B1
EP0286499B1 EP19880400709 EP88400709A EP0286499B1 EP 0286499 B1 EP0286499 B1 EP 0286499B1 EP 19880400709 EP19880400709 EP 19880400709 EP 88400709 A EP88400709 A EP 88400709A EP 0286499 B1 EP0286499 B1 EP 0286499B1
Authority
EP
European Patent Office
Prior art keywords
pitch
weight
treatment
equal
content
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.)
Expired - Lifetime
Application number
EP19880400709
Other languages
German (de)
French (fr)
Other versions
EP0286499A1 (en
Inventor
Denis Rue Du Capitaine Hazebrouck Cottinet
Serge Buche
Jean Louis Saint-Romain
Pierre Couderc
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.)
Arkema France SA
Original Assignee
Norsolor SA
Elf Atochem 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 Norsolor SA, Elf Atochem SA filed Critical Norsolor SA
Priority to AT88400709T priority Critical patent/ATE55776T1/en
Publication of EP0286499A1 publication Critical patent/EP0286499A1/en
Application granted granted Critical
Publication of EP0286499B1 publication Critical patent/EP0286499B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10C—WORKING-UP PITCH, ASPHALT, BITUMEN, TAR; PYROLIGNEOUS ACID
    • C10C1/00—Working-up tar

Definitions

  • the present invention relates to pitches, in particular the pitches of coal tar, without however being limited to the latter.
  • coal tars makes it possible to obtain, in substantially equal quantities, on the one hand, oils (benzene, toluene, xylene, the corresponding phenolic and methylated products, naphthalene, medium oils, anthracene, chrysene, etc.) , and, on the other hand, the concentrate or pitch.
  • oils benzene, toluene, xylene, the corresponding phenolic and methylated products, naphthalene, medium oils, anthracene, chrysene, etc.
  • pitches mention may be made in particular of their use as binders in the manufacture of carbon or graphite electrodes, which are used for the production of aluminum and ferrous or non-ferrous metals.
  • pitches When one starts from a tar containing more than 4% of a resins, one obtains, by simple distillation, pitches meeting these specifications. By differential thermal analysis, it can be seen that these pitches always have a glass transition domain ATg of the order of 55 ° C.
  • the present invention is based on the observation that the quality of a binding binder for an electrode can be further improved when it also has a glass transition domain ATg clearly more restricted than those known hitherto. As has just been indicated, no manufacturing process has yet made it possible to achieve this result so far.
  • the Depositing Company has now discovered that it is possible to achieve pitch maturation by means of high frequency wave treatment.
  • This treatment makes it possible to increase the fixed carbon content of the pitch, while retaining a good affinity for coke and while significantly reducing its glass transition domain.
  • the pitch according to the invention has an A Tg domain less than or equal to 40 ° C.
  • a subject of the present invention is also a process for manufacturing a pitch as defined above, a process according to which a pitch having a content of quinoline insoluble substances of less than 4% by weight approximately is subjected to a wave treatment. having a frequency between 0.9 and 300 GHz.
  • High frequency wave treatment consists of converting electrical energy into heat in dielectric (insulating) materials containing polar molecules.
  • the polar molecules subjected to the electromagnetic field, move away or approach violently, causing by collision a release of heat.
  • a conventional frequency of about 2.45 GHz is used.
  • the treatment is carried out in principle at atmospheric pressure; however, it is safe to operate under a pressure of up to 20 bar.
  • the temperature at which the treatment is carried out is controlled by the amount of electrical energy supplied to the system (magnetron). It is preferably between 350 and 450 ° C, in particular between 380 and 420 ° C.
  • the duration of the treatment is preferably between 1 and 1200 minutes. The shorter the temperature, the higher the temperature.
  • process of the present invention can be carried out continuously or batchwise.
  • An important advantage of the method according to the invention lies in a significant reduction in the duration of treatment, allowing an increase in productivity.
  • this heating mode makes it possible to avoid the coking and cracking phenomena mentioned above. We can therefore work without inconvenience with higher temperatures and shorter durations.
  • the present invention also relates to an electrode containing a binding pitch as defined above or obtained by a manufacturing process as defined above.
  • the pitch is preheated to a temperature of the order of 200 ° C. in a melter, before being conveyed to an electrically heated tubular oven, operating continuously.
  • the melter used consists of a closed reactor, with a capacity of 130 liters, fitted with mechanical stirring, and heated externally with regulation, by electrical resistors placed in a steel envelope and capable of delivering a total power of 30 kW.
  • the steel envelope constitutes a “calorie reservoir” and allows excess calories to be removed by injection of compressed air, if it is deemed necessary.
  • the pitch can thus be heated quickly to the desired temperature, while avoiding overheating points.
  • the pitch thus preheated in the melter whose viscosity is of the order of 50 centipoise, is then conveyed to the furnace continuously by means of a gear pump.
  • a gear pump This consists of a stainless steel body, fitted with a double preheating jacket; it allows flow rates of the order of 2 to 20 liters per hour.
  • the double jacket and all the tubes carrying the pitch are heated thanks to an oil bath, at a temperature of the order of 200 ° C.
  • the tubular oven is made of stainless steel and has a capacity of 4 liters. It is heated by means of electric resistors, delivering a total power of 4 kW and also placed in a double steel jacket having the same function as that equipping the melter. Maintaining the maturation temperature in the oven is ensured by regulation. Above the oven, a pyrex column head is placed which allows the volatile products to condense in order to limit their loss, such products playing an important role in the polycondensation reaction.
  • the pitch leaving the oven at the maturation temperature is cooled by the same oil bath playing the role of exchanger. Bottom and drain valves are placed in the system, in different places, and allow the rapid evacuation of the pitch at the end of the reaction or at any time. The pitch is then collected and weighed continuously.
  • Example 1 a coal tar pitch having a CIA softening point of 84.7 ° C is subjected to heat treatment, under the conditions described above, at the temperature of 405 ° C. and for 175 minutes . , a content of substances insoluble in quinoline (resins a) equal to 3.3% by weight, a content of resins a + equal to 24.1% by weight and a fixed carbon content equal to 48.0% by weight .
  • the binding pitch obtained at the end of this treatment has the characteristics indicated in the table below.
  • Example 2 the binder pitch obtained in Example 1 is subjected to flash distillation under a pressure of 0.145 bar so as to remove 4.5% of the oil it contains.
  • the binding pitch obtained at the end of this distillation has the characteristics indicated in the table below.
  • the equipment described above replacing the electric oven with a microwave applicator.
  • the latter consists of eight sections of guide stacked and offset from each other by 90 ° . Each of these sections is connected to a magnetron which can output 800 W, but voluntarily limited to 400 W to protect the magnetron against poor adaptation.
  • These magnetrons operate at a frequency of 2.45 GHz.
  • the stack of waveguides is traversed by a quartz reactor, with a useful capacity of 1000 cm 3 , in which the liquid pitch circulates.
  • a quartz sheath plunges into the reactor and allows, when the magnetrons are not in service, to measure the temperature within the liquid.
  • a thermocouple allows temperature regulation.
  • Example 3 the same pitch of coal tars as that described in Example 1 is subjected to treatment by high frequency waves, under the conditions described above, at the temperature of 415 ° C. and for 45 minutes.
  • the binding pitch obtained at the end of this treatment has the characteristics indicated in the table below.
  • the binder pitch obtained in Example 3 is subjected to flash distillation under a pressure of 0.145 bar, so as to remove 4.5% by weight (Example 4) and 1.3% respectively. weight (example 5) of the oil it contains.
  • the binding pitches obtained at the end of these distillations have the characteristics indicated in the table below.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Working-Up Tar And Pitch (AREA)
  • Battery Electrode And Active Subsutance (AREA)
  • Electrodes For Compound Or Non-Metal Manufacture (AREA)
  • Inert Electrodes (AREA)
  • Electric Connection Of Electric Components To Printed Circuits (AREA)
  • Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)
  • Connections Effected By Soldering, Adhesion, Or Permanent Deformation (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
  • Coupling Device And Connection With Printed Circuit (AREA)

Abstract

The disclosed bonding pitch for electrodes, having a softening point C.I.A. comprised between 80 DEG C. and 150 DEG C., a concentration of quinoline-insoluble substances higher or equal to 4% by weight, a concentration of alpha + beta resins comprised between 28 and 40% by weight, and a fixed carbon content determined according to the standard ISO 6998, at least equal to 51% by weight, is characterized by a vitreous transition domain DELTA Tg, determined by differential calorimetric analysis, at the most equal to 50 DEG C. In order to produce such a pitch, a pitch having a content of quinoline-insoluble substances lower than 4% by weight is subjected to a treatment by waves having a frequency between 0.9 and 300 GHz. Such treatment makes possible the increase of the carbon content of the pitch while preserving a good affinity to the coke and significantly decreasing its vitreous transitional domain.

Description

La présente invention concerne les brais, en particulier les brais de goudrons de houille, sans toutefois être limitée à ces derniers.The present invention relates to pitches, in particular the pitches of coal tar, without however being limited to the latter.

Les brais de goudrons de houille sont constitués par le concentrat de la distillation des goudrons de houille. Les brais sont des mélanges complexes :

  • 1 ) de molécules polyaromatiques, éventuellement porteuses de courtes chaînes aliphatiques ;
  • 2) de molécules polaires à caractère acide ou basique (phénols, naphtols, carbazole, bases pyridini- ques, etc.) ;
  • 3) éventuellement, de particules insolubles en suspension (particules de type noir de carbone, cénos- phères ou particules de coke polluées plus ou moins par des impuretés minérales).
Coal tar pitches consist of the concentrate from the distillation of coal tar. The pitches are complex mixtures:
  • 1) polyaromatic molecules, possibly carrying short aliphatic chains;
  • 2) polar molecules with an acidic or basic character (phenols, naphthols, carbazole, pyridine bases, etc.);
  • 3) possibly, insoluble particles in suspension (particles of the carbon black type, cenospheres or coke particles polluted more or less by mineral impurities).

On caractérise les brais et les goudrons par leur taux de substances insolubles dans les différents solvants ; ainsi, il est d'usage de considérer les trois fractions suivantes :

  • 1) les résines a, constituées par la fraction insoluble dans la quinoléine ;
  • 2) les résines p, constituées par la fraction insoluble dans le toluène et soluble dans la quinoléine ; et,
  • 3) les résines y, constituées par la fraction soluble dans le toluène.
The pitches and tars are characterized by their rate of substances insoluble in the various solvents; thus, it is customary to consider the following three fractions:
  • 1) resins a, constituted by the fraction insoluble in quinoline;
  • 2) p resins, consisting of the fraction insoluble in toluene and soluble in quinoline; and,
  • 3) the resins y, constituted by the fraction soluble in toluene.

On peut alors distinguer les goudrons servant à la préparation de brais selon leur teneur en résines α; on appellera goudrons «bas a», les goudrons renfermant moins de 2% en poids de résines a.We can then distinguish the tars used for the preparation of pitches according to their content of α resins; tars will be called "low a", the tars containing less than 2% by weight of resins a.

La distillation des goudrons de houille permet d'obtenir, en des quantités sensiblement égales, d'une part, des huiles (benzène, toluène, xylène, les produits correspondants phénoliques et méthylés, naphtalène, huiles moyennes, anthracène, chrysène, etc.), et, d'autre part, le concentrat ou brai.The distillation of coal tars makes it possible to obtain, in substantially equal quantities, on the one hand, oils (benzene, toluene, xylene, the corresponding phenolic and methylated products, naphthalene, medium oils, anthracene, chrysene, etc.) , and, on the other hand, the concentrate or pitch.

Parmi les applications des brais, on peut mentionner notamment leur utilisation en tant que liants dans la fabrication des électrodes de carbone ou de graphite, lesquelles sont utilisées pour la production d'aluminium et de métaux ferreux ou non ferreux.Among the applications of pitches, mention may be made in particular of their use as binders in the manufacture of carbon or graphite electrodes, which are used for the production of aluminum and ferrous or non-ferrous metals.

Les brais sont caractérisés par différentes données analytiques, dont la connaissance permet d'apprécier leur valeur d'usage pour l'application choisie ; on donnera ci-après une définition des différentes caractéristiques des brais qui seront évoquées dans le présent mémoire descriptif:

  • - le point de ramollissement C.I.A. (Cube In Air), exprimé en °C, grandeur déterminée selon la norme ASTM D 3104-77;
  • - la teneur en résines a et la teneur en résines a+p (ou fraction insoluble dans le toluène) (exprimées en % en poids) obtenues par les modes opératoires indiqués dans les normes respectivement ISO 6791 et ISO 6376 ;
  • - la teneur en carbone fixe (exprimée en % en poids), qui traduit le rendement en coke ou le pouvoir en carbone du brai, cette teneur étant calculée selon la norme ISO 6998 ;
  • - l'affinité brai-coke mesurée selon le test de pénétration décrit par P. Couderc, P. Hyvernat et G.L. Le- marchand dans la revue «FUEL, 1986, Vol. 65, 2, 281-287» ; ce test permet de caractériser les propriétés de pénétration et d'écoulement des brais dans un lit de coke (écoulement rapide ou retardé ; pénétration complète ou incomplète). Les courbes d'écoulement obtenues permettent d'obtenir deux températures caractéristiques :
  • - T2 : température finale de pénétration
  • - Tr : température obtenue par extrapolation du début de la courbe d'écoulement ;
  • - la mesure, par analyse calorimétrique différentielle (effectuée dans les conditions suivantes : un échantillon de 20 mg de brai est porté à 140°C, puis refroidi en 3 minutes jusqu'à -100°C, puis réchauffé à la vitesse de 30°C par minute),de la température et du domaine de transition vitreuse : Tg et ATg.
The pitches are characterized by various analytical data, the knowledge of which makes it possible to assess their use value for the chosen application; a definition will be given below of the different characteristics of the pitches which will be mentioned in this specification:
  • - the CIA (Cube In Air) softening point, expressed in ° C, quantity determined according to standard ASTM D 3104-77;
  • the content of resins a and the content of resins a + p (or fraction insoluble in toluene) (expressed in% by weight) obtained by the procedures indicated in the standards ISO 6791 and ISO 6376 respectively;
  • - the fixed carbon content (expressed in% by weight), which reflects the coke yield or the carbon power of the pitch, this content being calculated according to ISO standard 6998;
  • - the pitch-coke affinity measured according to the penetration test described by P. Couderc, P. Hyvernat and GL Le-marchand in the review “FUEL, 1986, Vol. 65, 2, 281-287 ”; this test makes it possible to characterize the penetration and flow properties of the pitches in a coke bed (rapid or delayed flow; complete or incomplete penetration). The flow curves obtained allow two characteristic temperatures to be obtained:
  • - T 2 : final penetration temperature
  • - T r : temperature obtained by extrapolation from the start of the flow curve;
  • - the measurement, by differential scanning calorimetry (carried out under the following conditions: a sample of 20 mg of pitch is brought to 140 ° C, then cooled in 3 minutes to -100 ° C, then reheated at the speed of 30 ° C per minute), the temperature and the glass transition range: Tg and A Tg.

Un brai-liant jugé satisfaisant pour la fabrication d'une électrode de carbone ou de graphite, respecte généralement les spécifications suivantes :

  • - un point de ramollissement C.I.A. de l'ordre de 100 à 130°C ;
  • - une teneur en résines a de l'ordre de 8 à 15% en poids;
  • - une teneur en résines a + p de l'ordre de 28 à 35% en poids ;
  • - une teneur en carbone fixe de l'ordre de 54 à 62% en poids ; et
  • - une bonne affinité brai-coke (écoulement rapide ou peu retardé, pénétration complète).
A pitch-binder considered satisfactory for the manufacture of a carbon or graphite electrode generally complies with the following specifications:
  • - a CIA softening point of the order of 100 to 130 ° C;
  • - A resin content has of the order of 8 to 15% by weight;
  • - A resin content a + p of the order of 28 to 35% by weight;
  • - a fixed carbon content of the order of 54 to 62% by weight; and
  • - a good pitch-coke affinity (rapid or slightly delayed flow, complete penetration).

Lorsque l'on part d'un goudron contenant plus de 4% de résines a, on obtient, par simple distillation, des brais répondant à ces spécifications. Par analyse thermique différentielle, on constate que ces brais ont toujours un domaine de transition vitreuse ATg de l'ordre de 55°C.When one starts from a tar containing more than 4% of a resins, one obtains, by simple distillation, pitches meeting these specifications. By differential thermal analysis, it can be seen that these pitches always have a glass transition domain ATg of the order of 55 ° C.

En revanche, lorsque l'on distille un goudron «bas α», on obtient, pour le même point de ramollissement, un brai dont la teneur en résines a est au plus égale à 5% en poids, la teneur en résines a + p est de l'ordre de 25% en poids, et la teneur en carbone fixe est inférieure à 54% en poids. Ce brai, bien qu'ayant une bonne affinité envers le coke, est considéré comme trop pauvre en carbone. Pour pallier à cette déficience, il est possible de réaliser un traitement thermique à des températures supérieures à 350°C. Dans ces conditions, les brais obtenus présentent des teneurs en carbone fixe et en résines a + p acceptables. En revanche,leur affinité envers le coke est difficilement contrôlable. De plus, on note une nette augmentation du domaine de transition vitreuse ATg.On the other hand, when a “low α” tar is distilled, one obtains, for the same softening point, a pitch whose resin content a is at most equal to 5% by weight, the resin content a + p is of the order of 25% by weight, and the fixed carbon content is less than 54% by weight. This pitch, although having a good affinity for coke, is considered to be too low in carbon. To overcome this deficiency, it is possible to carry out a heat treatment at temperatures above 350 ° C. Under these conditions, the pitches obtained have fixed carbon and a + resin contents p acceptable. However, their affinity for coke is difficult to control. In addition, there is a marked increase in the glass transition domain A Tg.

Par ailleurs, l'expérience montre que de tels traitements, lorsqu'ils sont effectués dans des conditions industrielles, s'accompagnent de phénomènes de cokéfaction et craquages liés à l'existence de gradients thermiques au voisinage de la paroi du four.Furthermore, experience shows that such treatments, when carried out under industrial conditions, are accompanied by coking and cracking phenomena linked to the existence of thermal gradients in the vicinity of the wall of the furnace.

La présente invention est basée sur la constatation que la qualité d'un brai liant pour électrode peut être encore améliorée lorsqu'il présente en outre un domaine de transition vitreuse ATg nettement plus restreint que ceux connus jusqu'alors. Comme on vient de l'indiquer, aucun procédé de fabrication ne permettait toutefois d'atteindre ce résultat jusqu'à présent.The present invention is based on the observation that the quality of a binding binder for an electrode can be further improved when it also has a glass transition domain ATg clearly more restricted than those known hitherto. As has just been indicated, no manufacturing process has yet made it possible to achieve this result so far.

La Société déposante a maintenant découvert qu'il est possible de réaliser une maturation du brai au moyen d'un traitement par ondes haute frequence. Ce traitement permet d'augmenter la teneur en carbone fixe du brai, tout en lui conservant une bonne affinité envers le coke et tout en diminuant significativement son domaine de transition vitreuse.The Depositing Company has now discovered that it is possible to achieve pitch maturation by means of high frequency wave treatment. This treatment makes it possible to increase the fixed carbon content of the pitch, while retaining a good affinity for coke and while significantly reducing its glass transition domain.

La présente invention a donc d'abord pour objet un brai liant pour électrode, possédant :

  • - un point de ramollissement C.I.A. compris entre 80°C et 150°C,
  • - une teneur en substances insolubles dans la quinoléine supérieure ou égale à 4% en poids,
  • - une teneur en résines a+p comprise entre 28 et 40% en poids, et
  • - une teneur en carbone fixe, déterminée selon la norme ISO 6998, au moins égale à 51 % en poids, caractérisé en ce que son domaine de transition vitreuse ATg, déterminé par analyse calorimétrique différentielle, est inférieur ou égal à 50°C.
The present invention therefore firstly relates to a binder pitch for an electrode, having:
  • - a CIA softening point between 80 ° C and 150 ° C,
  • - a content of substances insoluble in quinoline greater than or equal to 4% by weight,
  • a content of resins a + p of between 28 and 40% by weight, and
  • - a fixed carbon content, determined according to ISO 6998, at least equal to 51% by weight, characterized in that its glass transition range A Tg, determined by differential scanning calorimetry, is less than or equal to 50 ° C.

De manière plus particulièrement préférée, le brai selon l'invention possède un domaine ATg inférieur ou égal à 40°C.More particularly preferably, the pitch according to the invention has an A Tg domain less than or equal to 40 ° C.

Outre les caractéristiques précitées, le brai selon l'invention pourra avantageusement posséder l'une ou l'autre des propriétés d'écoulement suivantes, déterminées selon le test de pénétration précité (en utilisant une granulométrie moyenne du lit de coke de 120 µm environ et une vitesse de chauffe de 20°C par heure) :

  • - un retard à l'écoulement T2- Ti au plus égal à 15°C ;
  • - une température finale de pénétration T2 au plus égale à 180°C.
In addition to the above characteristics, the pitch according to the invention may advantageously have one or the other of the following flow properties, determined according to the aforementioned penetration test (using an average particle size of the coke bed of approximately 120 μm and a heating rate of 20 ° C per hour):
  • - A delay in flow T 2 - Ti at most equal to 15 ° C;
  • - a final penetration temperature T 2 at most equal to 180 ° C.

La présente invention a également pour objet un procédé de fabrication d'un brai tel que défini ci-dessus, procédé suivant lequel on soumet un brai présentant une teneur en substances insolubles dans la quinoléine inférieure à 4% en poids environ à un traitement par ondes ayant une fréquence comprise entre 0,9 et 300 GHz.A subject of the present invention is also a process for manufacturing a pitch as defined above, a process according to which a pitch having a content of quinoline insoluble substances of less than 4% by weight approximately is subjected to a wave treatment. having a frequency between 0.9 and 300 GHz.

Le traitement par ondes haute fréquence consiste à convertir de l'énergie électrique en chaleur dans des matériaux diélectriques (isolants) contenant des molécules polaires. Les molécules polaires, soumises au champ électromagnétique, s'éloignent ou se rapprochent violemment, provoquant par collision un dégagement de chaleur.High frequency wave treatment consists of converting electrical energy into heat in dielectric (insulating) materials containing polar molecules. The polar molecules, subjected to the electromagnetic field, move away or approach violently, causing by collision a release of heat.

De manière avantageuse, on utilise une fréquence classique de 2,45 GHz environ.Advantageously, a conventional frequency of about 2.45 GHz is used.

Conformément à la présente invention, on effectue le traitement en principe à la pression atmosphérique ; cependant, on peut sans inconvénient opérer sous une pression pouvant aller jusqu'à 20 bars.In accordance with the present invention, the treatment is carried out in principle at atmospheric pressure; however, it is safe to operate under a pressure of up to 20 bar.

La température à laquelle on effectue le traitement est contrôlée par la quantité d'énergie électrique fournie au système (magnétron). Elle est, de préférence, comprise entre 350 et 450°C, en particulier entre 380 et 420°C.The temperature at which the treatment is carried out is controlled by the amount of electrical energy supplied to the system (magnetron). It is preferably between 350 and 450 ° C, in particular between 380 and 420 ° C.

La durée du traitement est, de préférence, comprise entre 1 et 1200 minutes. Elle est d'autant plus courte que la température est plus élevée.The duration of the treatment is preferably between 1 and 1200 minutes. The shorter the temperature, the higher the temperature.

De plus, après le traitement selon l'invention, on pourra procéder, comme on le fait d'habitude,. à une distillation complémentaire, par exemple sous pression réduite, pour atteindre le point de ramollissement C.I.A. désiré.In addition, after the treatment according to the invention, it will be possible to proceed, as usual. additional distillation, for example under reduced pressure, to reach the desired C.I.A. softening point.

Par ailleurs, le procédé de la présente invention peut être mis en oeuvre en continu ou en discontinu.Furthermore, the process of the present invention can be carried out continuously or batchwise.

Un avantage important du procédé selon l'invention, par rapport aux procédés traditionnels par chauffage électrique, réside dans une diminution importante de la durée de traitement, permettant une augmentation de la productivité. De plus, ce mode de chauffage permet d'éviter les phénomènes de cokéfaction et de craquage évoqués plus haut. On peut donc sans inconvénient travailler avec des températures plus élevées et des durées plus courtes.An important advantage of the method according to the invention, compared to traditional methods by electric heating, lies in a significant reduction in the duration of treatment, allowing an increase in productivity. In addition, this heating mode makes it possible to avoid the coking and cracking phenomena mentioned above. We can therefore work without inconvenience with higher temperatures and shorter durations.

La présente invention a également pour objet une électrode contenant un brai liant tel que défini ci-dessus ou obtenu par un procédé de fabrication tel que défini ci-dessus.The present invention also relates to an electrode containing a binding pitch as defined above or obtained by a manufacturing process as defined above.

Dans les exemples qui suivent, on a comparé le traitement thermique de maturation de brai en continu, d'une part, par un chauffage classique dans un four électrique par effet Joule, et, d'autre part, par un traitement au moyen d'ondes haute fréquence selon l'invention, dans un four à micro-ondes.In the examples which follow, a comparison has been made of the heat treatment for continuous pitch maturation, on the one hand, by conventional heating in an electric oven by Joule effect, and, on the other hand, by treatment by means of high frequency waves according to the invention, in a microwave oven.

EXEMPLES 1 et 2 (COMPARATIFS)EXAMPLES 1 and 2 (COMPARATIVE) TRAITEMENT THERMIQUE DU BRAI DANS UN FOUR ELECTRIQUEHEAT TREATMENT OF PITCH IN AN ELECTRIC OVEN a) Principea) Principle

On préchauffe le brai jusqu'à une température de l'ordre de 200°C dans un fondoir, avant de l'acheminer vers un four tubulaire chauffé électriquement, fonctionnant en continu .The pitch is preheated to a temperature of the order of 200 ° C. in a melter, before being conveyed to an electrically heated tubular oven, operating continuously.

b) Descriptif de l'appareillageb) Description of the equipment

Le fondoir utilisé consiste en un réacteur fermé, d'une capacité de 130 litres, muni d'une agitation mécanique, et chauffé extérieurement avec régulation, par des résistances électriques placées dans une enveloppe en acier et pouvant délivrer une puissance totale de 30 kW. L'enveloppe en acier constitue un «réservoir à calories> et permet d'évacuer les calories en excès par injection d'air comprimé, si on le juge nécessaire. Le brai peut ainsi être chauffé rapidement jusqu'à la température désirée, tout en évitant les points de surchauffe.The melter used consists of a closed reactor, with a capacity of 130 liters, fitted with mechanical stirring, and heated externally with regulation, by electrical resistors placed in a steel envelope and capable of delivering a total power of 30 kW. The steel envelope constitutes a “calorie reservoir” and allows excess calories to be removed by injection of compressed air, if it is deemed necessary. The pitch can thus be heated quickly to the desired temperature, while avoiding overheating points.

Le brai ainsi préchauffé dans le fondoir, dont la viscosité est de l'ordre de 50 centipoises, est ensuite véhiculé vers le four en continu grâce à une pompe à engrenages. Celle-ci est constituée d'un corps en acier inoxydable, muni d'une double enveloppe de préchauffage ; elle permet d'avoir des débits de l'ordre de 2 à 20 litres par heure. La double enveloppe et tous les tubes véhiculant le brai sont réchauffés grâce à un bain d'huile, à une température de l'ordre de 200°C.The pitch thus preheated in the melter, whose viscosity is of the order of 50 centipoise, is then conveyed to the furnace continuously by means of a gear pump. This consists of a stainless steel body, fitted with a double preheating jacket; it allows flow rates of the order of 2 to 20 liters per hour. The double jacket and all the tubes carrying the pitch are heated thanks to an oil bath, at a temperature of the order of 200 ° C.

Le four tubulaire est en acier inoxydable et il présente une capacité de 4 litres. Il est chauffé au moyen de résistances électriques, délivrant une puissance totale de 4 kW et placé également dans une double enveloppe en acier ayant la même fonction que celle équipant le fondoir. Le maintien de la température de maturation dans le four est assuré par régulation. Au-dessus du four, est placée une tête de colonne en pyrex qui permet de condenser les produits volatils afin d'en limiter la perte, de tels produits jouant un rôle important dans la réaction de polycondensation.The tubular oven is made of stainless steel and has a capacity of 4 liters. It is heated by means of electric resistors, delivering a total power of 4 kW and also placed in a double steel jacket having the same function as that equipping the melter. Maintaining the maturation temperature in the oven is ensured by regulation. Above the oven, a pyrex column head is placed which allows the volatile products to condense in order to limit their loss, such products playing an important role in the polycondensation reaction.

Le brai sortant du four à la température de maturation est refroidi par le même bain d'huile jouant le rôle d'échangeur. Des vannes de fond de cuve et de vidange sont placées dans le système, à différents endroits, et permettent l'évacuation rapide du brai en fin de réaction ou à tout moment. Le brai est ensuite recueilli et pesé en continu.The pitch leaving the oven at the maturation temperature is cooled by the same oil bath playing the role of exchanger. Bottom and drain valves are placed in the system, in different places, and allow the rapid evacuation of the pitch at the end of the reaction or at any time. The pitch is then collected and weighed continuously.

c) Conditions de la maturationc) Maturing conditions

Avec le dispositif précité, on a pu opérer à une température allant jusqu'à environ 405°C. Toutefois, il est très difficile de dépasser cette température, en raison du départ très important, à la pression atmosphérique, de produits volatils lors de la maturation, de tels départs étant favorisés par des réactions de craquage dues à des effets thermiques au voisinage de la paroi. En effet, on observe une différence de température entre la paroi et le coeur du four qui est de l'ordre de 20°C, à la température de traitement précitée, pour un débit de l'ordre de 2,7 litres par heure.With the above-mentioned device, it was possible to operate at a temperature of up to approximately 405 ° C. However, it is very difficult to exceed this temperature, due to the very large departure, at atmospheric pressure, of volatile products during the maturation, such departures being favored by cracking reactions due to thermal effects in the vicinity of the wall. Indeed, there is a temperature difference between the wall and the core of the oven which is of the order of 20 ° C, at the aforementioned treatment temperature, for a flow rate of the order of 2.7 liters per hour.

Selon l'exemple 1, on soumet à traitement thermique, dans les conditions décrites ci-dessus, à la température de 405°C et pendant 175 minutes, un brai de goudrons de houille possédant un point de ramollissement C.I.A. de 84,7°C, une teneur en substances insolubles dans la quinoléine (résines a) égale à 3,3% en poids, une teneur en résines a + égale à 24,1% en poids et une teneur en carbone fixe égale à 48,0% en poids. Le brai liant obtenu à l'issue de ce traitement possède les caractéristiques indiquées au tableau ci-après.According to Example 1, a coal tar pitch having a CIA softening point of 84.7 ° C is subjected to heat treatment, under the conditions described above, at the temperature of 405 ° C. and for 175 minutes . , a content of substances insoluble in quinoline (resins a) equal to 3.3% by weight, a content of resins a + equal to 24.1% by weight and a fixed carbon content equal to 48.0% by weight . The binding pitch obtained at the end of this treatment has the characteristics indicated in the table below.

Selon l'exemple 2, on soumet le brai liant obtenu à l'exemple 1 à une distillation éclair sous une pression de 0,145 bar de manière à éliminer 4,5% de l'huile qu'il contient. Le brai liant obtenu à l'issue de cette distillation possède les caractéristiques indiquées au tableau ci-après.According to Example 2, the binder pitch obtained in Example 1 is subjected to flash distillation under a pressure of 0.145 bar so as to remove 4.5% of the oil it contains. The binding pitch obtained at the end of this distillation has the characteristics indicated in the table below.

EXEMPLES 3 à 5EXAMPLES 3 to 5 TRAITEMENT THERMIQUE DU BRAI DANS UN FOUR A MICRO-ONDESHEAT TREATMENT OF PITCH IN A MICROWAVE OVEN a) Descriptif de l'appareillagea) Description of the equipment

On utilise l'appareillage décrit précédemment, en remplaçant le four électrique par un applicateur de micro-ondes. Ce dernier est constitué par huit tronçons de guide empilés et décalés les uns par rapport aux autres de 90°. Chacun de ces tronçons est relié à un magnétron pouvant débiter 800 W, mais volontairement limité à 400 W pour protéger le magnétron contre une mauvaise adaptation. Ces magnétrons fonctionnent à la fréquence de 2,45 GHz. L'empilage de guides d'onde est traversé par un réacteur en quartz, d'une capacité utile de 1000cm3, dans lequel circule le brai liquide. Une gaine en quartz plonge dans le réacteur et permet, lorsque les magnétrons ne sont pas en service, de mesurer la température au sein du liquide. A la sortie du réacteur, un thermocouple permet la régulation en température.We use the equipment described above, replacing the electric oven with a microwave applicator. The latter consists of eight sections of guide stacked and offset from each other by 90 ° . Each of these sections is connected to a magnetron which can output 800 W, but voluntarily limited to 400 W to protect the magnetron against poor adaptation. These magnetrons operate at a frequency of 2.45 GHz. The stack of waveguides is traversed by a quartz reactor, with a useful capacity of 1000 cm 3 , in which the liquid pitch circulates. A quartz sheath plunges into the reactor and allows, when the magnetrons are not in service, to measure the temperature within the liquid. At the outlet of the reactor, a thermocouple allows temperature regulation.

b) Conditions de traitementb) Processing conditions

Contrairement au traitement thermique dans un four électrique, le traitement effectué dans l'appareillage décrit ci-dessus permet :

  • - de traiter des brais, avec un débit de 2,7 I/h, à toute température allant jusqu'à 450°C ;
  • - de supprimer la période de préchauffage ;
  • - de ramener la puissance utile à 2,7 kW au lieu de 3,2 kW.
Unlike the heat treatment in an electric oven, the treatment carried out in the equipment described above allows:
  • - to treat pitches, with a flow rate of 2.7 I / h, at any temperature up to 450 ° C;
  • - to eliminate the preheating period;
  • - reduce the useful power to 2.7 kW instead of 3.2 kW.

Selon l'exemple 3, on soumet au traitement par ondes hautes fréquences, dans les conditions décrites ci-dessus, à la température de 415°C et pendant 45 minutes, le même brai de goudrons de houille que celui décrit à l'exemple 1. Le brai liant obtenu à l'issue de ce traitement possède les caractéristiques indiquées au tableau ci-après.According to Example 3, the same pitch of coal tars as that described in Example 1 is subjected to treatment by high frequency waves, under the conditions described above, at the temperature of 415 ° C. and for 45 minutes. The binding pitch obtained at the end of this treatment has the characteristics indicated in the table below.

Selon les exemples 4 et 5, on soumet le brai liant obtenu à l'exemple 3 à une distillation éclair sous une pression de 0,145 bar, de manière à éliminer respectivement 4,5% en poids (exemple 4) et 1,3% en poids (exemple 5) de l'huile qu'il contient. Les brais liants obtenus à l'issue de ces distillations possèdent les caractéristiques indiquées au tableau ci-après.

Figure imgb0001
According to Examples 4 and 5, the binder pitch obtained in Example 3 is subjected to flash distillation under a pressure of 0.145 bar, so as to remove 4.5% by weight (Example 4) and 1.3% respectively. weight (example 5) of the oil it contains. The binding pitches obtained at the end of these distillations have the characteristics indicated in the table below.
Figure imgb0001

Claims (12)

1. Binder pitch for an electrode, having:
- a C.I.A. softening point of between 80°C and 150°C,
- a content of quinoline-insoluble substances higher than or equal to 4% by weight,
- a content of a + p resins of between 28 and 40% by weight, and
- a fixed carbon content, determined according to the ISO standard 6998, of at least 51% by weight, characterized in that its glass transition range ATg, determined by differential calorimetric analysis, is less than or equal to 50°C.
2. Pitch according to Claim 1, characterized in that its glass transition range ATg is less than or equal to 40°C.
3. Pitch according to either of Claims 1 and 2, characterized in that it has a flow delay T2-Ti, according to the pitch-coke affinity test, not exceeding 15°C.
4. Pitch according to one of Claims 1 to 3, characterized in that it has a final penetration temperature T2, according to the pitch-coke affinity test, not exceeding 180°C.
5. Process for the manufacture of a binder pitch for an electrode, such as defined in one of Claims 1 to 4, characterized in that a pitch exhibiting a content of quinoline-insoluble substances of less than 4% by weight is subjected to a treatment by waves which have a frequency of between 0.9 and 300 GHz.
6. Process according to Claim 5, characterized in that a frequency of 2.45 GHz is employed.
7. Process according to either of Claims 5 and 6, characterized in that the treatment is carried out at atmospheric pressure.
8. Process according to either of Claims 5 and 6, characterized in that the treatment is carried out at a pressure which may go up to 20 bars.
9. Process according to one of Claims 5 to 8, characterized in that the operation is carried out at a temperature of between 350 and 450°C.
10. Process according to one of Claims 5 to 9, characterized in that the treatment is carried out for a duration of 1 to 1,200 minutes.
11. Process according to one of Claims 5 to 10, characterized in that after the treatment a complementary distillation is carried out to reach the desired C.I.A. softening point.
12. Electrode, characterized in that it contains a binder pitch in accordance with one of Claims 1 to 4 or obtained according to one of Claims 5 to 11.
EP19880400709 1987-03-24 1988-03-23 Pitch for binding electrodes and process for preparing said pitch Expired - Lifetime EP0286499B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT88400709T ATE55776T1 (en) 1987-03-24 1988-03-23 ELECTRODE BINDER PITCH AND METHOD OF MAKING THE SAME.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8704054A FR2612935B1 (en) 1987-03-24 1987-03-24 BINDING PIT FOR ELECTRODE AND MANUFACTURING METHOD THEREOF
FR8704054 1987-03-24

Publications (2)

Publication Number Publication Date
EP0286499A1 EP0286499A1 (en) 1988-10-12
EP0286499B1 true EP0286499B1 (en) 1990-08-22

Family

ID=9349351

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19880400709 Expired - Lifetime EP0286499B1 (en) 1987-03-24 1988-03-23 Pitch for binding electrodes and process for preparing said pitch

Country Status (14)

Country Link
US (1) US5120424A (en)
EP (1) EP0286499B1 (en)
JP (1) JPH02502650A (en)
AT (1) ATE55776T1 (en)
AU (1) AU607760B2 (en)
BR (1) BR8807335A (en)
CA (1) CA1304199C (en)
DE (1) DE3860473D1 (en)
ES (1) ES2016675B3 (en)
FR (1) FR2612935B1 (en)
GR (1) GR3000922T3 (en)
NZ (1) NZ223941A (en)
WO (1) WO1988007571A1 (en)
ZA (1) ZA881882B (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE69228663T2 (en) * 1991-12-25 1999-09-30 Mitsubishi Chem Corp Pitch-based carbon fibers and processes for making them
RU2288938C1 (en) * 2005-10-10 2006-12-10 Общество с ограниченной ответственностью "Инженерно-технологический центр" Method of preparing binding pitch for electrode materials
CN1970689B (en) * 2006-12-13 2010-05-12 上海奥韦通工程技术有限公司 Process for preparing modified asphalt

Family Cites Families (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1323457A (en) * 1962-06-01 1963-04-05 Coal Tar Res Ass Improvements in the manufacture of coal tar-based products
FR2250571B1 (en) * 1973-11-12 1980-01-04 British Petroleum Co
JPS59758B2 (en) * 1976-08-03 1984-01-09 理化学研究所 Scale adhesion prevention method
US4096056A (en) * 1976-10-21 1978-06-20 Witco Chemical Corporation Method of producing an impregnating petroleum pitch
FR2392143A1 (en) * 1977-05-25 1978-12-22 British Petroleum Co PROCESS FOR MANUFACTURING CARBON OR GRAPHITE FIBERS FROM NATURAL ORGANIC MATERIAL FIBERS BY USE OF HYPERFREQUENCES
DE2966700D1 (en) * 1978-06-15 1984-03-29 Gte Laboratories Inc High strength silicon nitride
JPS57125289A (en) * 1981-01-28 1982-08-04 Toa Nenryo Kogyo Kk Preparation of optically anisotropic carbonaceous pitch
JPH0699693B2 (en) * 1981-09-07 1994-12-07 東燃株式会社 Optically anisotropic carbonaceous pitch and its manufacturing method
US4427530A (en) * 1982-02-08 1984-01-24 Exxon Research And Engineering Co. Aromatic pitch derived from a middle fraction of a cat cracker bottom
JPS58142976A (en) * 1982-02-22 1983-08-25 Toa Nenryo Kogyo Kk Preparation of optically anisotropic pitch having uniformity and low softening point
US4518482A (en) * 1982-07-19 1985-05-21 E. I. Du Pont De Nemours And Company Pitch for direct spinning into carbon fibers derived from a coal distillate feedstock
US4548703A (en) * 1982-07-19 1985-10-22 E. I. Du Pont De Nemours And Company Pitch for direct spinning into carbon fibers
US4581123A (en) * 1983-03-28 1986-04-08 E. I. Du Pont De Nemours And Company Custom blended precursor for carbon artifact manufacture
US4518483A (en) * 1983-06-27 1985-05-21 E. I. Du Pont De Nemours And Company Aromatic pitch from asphaltene fractions
CA1193574A (en) * 1983-07-14 1985-09-17 Jeffrey K.S. Wan Hydrodesulphurization of hydrocracked pitch
US4664774A (en) * 1984-07-06 1987-05-12 Allied Corporation Low solids content, coal tar based impregnating pitch

Also Published As

Publication number Publication date
FR2612935A1 (en) 1988-09-30
NZ223941A (en) 1989-10-27
AU1542188A (en) 1988-11-02
US5120424A (en) 1992-06-09
CA1304199C (en) 1992-06-30
ZA881882B (en) 1990-01-31
EP0286499A1 (en) 1988-10-12
ATE55776T1 (en) 1990-09-15
ES2016675B3 (en) 1990-11-16
DE3860473D1 (en) 1990-09-27
JPH02502650A (en) 1990-08-23
BR8807335A (en) 1990-03-13
WO1988007571A1 (en) 1988-10-06
AU607760B2 (en) 1991-03-14
GR3000922T3 (en) 1991-12-10
FR2612935B1 (en) 1989-06-09

Similar Documents

Publication Publication Date Title
US4086156A (en) Pitch bonded carbon electrode
JP2002338967A (en) Coal tar using high efficiency evaporative distillation method and hydrocarbon mixed pitch product
CH652739A5 (en) PROCESS AND APPARATUS FOR THE PRODUCTION OF A CRYSTALLIZABLE CARBONACEOUS MATERIAL.
US4096056A (en) Method of producing an impregnating petroleum pitch
US1925005A (en) Coal treatment process
EP0286499B1 (en) Pitch for binding electrodes and process for preparing said pitch
CN86102643B (en) Process for treating heavy petroleum oil reside
EP0252356A1 (en) Process and furnace for the steam cracking of hydrocarbons for the preparation of olefins and diolefins
US3928169A (en) Production of pitch substantially soluble in quinoline
JP7185650B2 (en) Coating pitch for lithium ion secondary battery negative electrode material and method for producing the same
EP0121530B1 (en) Graphitazation method and furnace
JPS63128096A (en) Premium coking method
EP0252355B1 (en) Process and furnace for the steam cracking of hydrocarbons for the preparation of olefins and diolefins
DE2608438C2 (en) Process for the manufacture of a petroleum pitch binder for the manufacture of carbon electrodes
FR2481310A1 (en) PROCESS FOR PRODUCING BRAI FROM PETROLEUM FRACTIONS, BRAI OBTAINED, DEVICE FOR CARRYING OUT THE METHOD AND USE OF THE BRAI
JPH07500143A (en) Method for producing pitch for carbon electrode impregnation from coal tar
JPH07110948B2 (en) A method for continuously processing vacuum distillation residual oil in a crude oil refinery.
JPH0471117B2 (en)
FR2507209A1 (en) AQUEOUS TEMPERING MEDIUM FOR FERROUS METALS AND ALLOYS
RU2085571C1 (en) Method of producing petroleum electrode pitch
BE889974Q (en) PROCESS FOR THE MANUFACTURE OF TARS FOR THE MANUFACTURE OF ELECTRODE COAL OR OTHER KINDS OF AGGLOMERATES
DE3035593C2 (en) Process for coking high-boiling, aromatic hydrocarbon mixtures to carbon materials with consistent properties
JPH02302493A (en) Production of high-grade petroleum tar pitch
RU2502782C2 (en) Method for obtaining anisotropic fibre-forming petroleum pitch by toluene extraction under supercritical conditions
US2716085A (en) Adhesive petroleum lubricant

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 ES FR GB GR IT LI LU NL SE

17P Request for examination filed

Effective date: 19890425

17Q First examination report despatched

Effective date: 19900108

ITF It: translation for a ep patent filed

Owner name: RIF. ISCRIZIONE REG.: 28/11/97;FIAMMENGHI - DOMENI

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 ES FR GB GR IT LI LU NL SE

REF Corresponds to:

Ref document number: 55776

Country of ref document: AT

Date of ref document: 19900915

Kind code of ref document: T

REF Corresponds to:

Ref document number: 3860473

Country of ref document: DE

Date of ref document: 19900927

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)
RIN2 Information on inventor provided after grant (corrected)

Free format text: COTTINET, DENIS RUE DU CAPITAINE HAZEBROUCK * BUCHE, SERGE * SAINT-ROMAIN, JEAN LOUIS * COUDERC, PIERRE

RAP2 Party data changed (patent owner data changed or rights of a patent transferred)

Owner name: ATOCHEM

REG Reference to a national code

Ref country code: GR

Ref legal event code: FG4A

Free format text: 3000922

NLT2 Nl: modifications (of names), taken from the european patent patent bulletin

Owner name: ATOCHEM TE PUTEAUX, FRANKRIJK.

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
ITTA It: last paid annual fee
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GR

Payment date: 19921230

Year of fee payment: 6

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

Ref country code: FR

Payment date: 19930309

Year of fee payment: 6

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

Ref country code: AT

Payment date: 19930311

Year of fee payment: 6

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

Ref country code: GB

Payment date: 19930312

Year of fee payment: 6

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

Ref country code: SE

Payment date: 19930315

Year of fee payment: 6

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

Ref country code: DE

Payment date: 19930324

Year of fee payment: 6

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

Ref country code: CH

Payment date: 19930325

Year of fee payment: 6

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

Ref country code: NL

Payment date: 19930331

Year of fee payment: 6

Ref country code: ES

Payment date: 19930331

Year of fee payment: 6

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

Ref country code: LU

Payment date: 19930421

Year of fee payment: 6

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

Ref country code: BE

Payment date: 19930504

Year of fee payment: 6

EPTA Lu: last paid annual fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

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

Effective date: 19940323

Ref country code: GB

Effective date: 19940323

Ref country code: AT

Effective date: 19940323

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: 19940324

Ref country code: ES

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

Effective date: 19940324

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

Ref country code: LI

Effective date: 19940331

Ref country code: CH

Effective date: 19940331

Ref country code: BE

Effective date: 19940331

BERE Be: lapsed

Owner name: ATOCHEM

Effective date: 19940331

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

Ref country code: GR

Free format text: THE PATENT HAS BEEN ANNULLED BY A DECISION OF A NATIONAL AUTHORITY

Effective date: 19940930

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

Ref country code: NL

Effective date: 19941001

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee
GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19940323

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

Ref country code: FR

Effective date: 19941130

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

Ref country code: CH

Ref legal event code: AUV

Free format text: LE BREVET CI-DESSUS EST TOMBE EN DECHEANCE, FAUTE DE PAIEMENT, DE LA 7E ANNUITE.

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

Ref country code: DE

Effective date: 19941201

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

EUG Se: european patent has lapsed

Ref document number: 88400709.7

Effective date: 19941010

REG Reference to a national code

Ref country code: GR

Ref legal event code: MM2A

Free format text: 3000922

REG Reference to a national code

Ref country code: ES

Ref legal event code: FD2A

Effective date: 19990301

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;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.

Effective date: 20050323