EP0042631A1 - Procédé de phosphatation de surfaces métalliques - Google Patents

Procédé de phosphatation de surfaces métalliques Download PDF

Info

Publication number
EP0042631A1
EP0042631A1 EP81200442A EP81200442A EP0042631A1 EP 0042631 A1 EP0042631 A1 EP 0042631A1 EP 81200442 A EP81200442 A EP 81200442A EP 81200442 A EP81200442 A EP 81200442A EP 0042631 A1 EP0042631 A1 EP 0042631A1
Authority
EP
European Patent Office
Prior art keywords
phosphating
metal surfaces
bath
manganese
phosphating solution
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
EP81200442A
Other languages
German (de)
English (en)
Other versions
EP0042631B1 (fr
Inventor
Han Yong Dr. Dipl.-Chem. Oei
Günter Ing. grad. Siemund
Rudolf Vey
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.)
GEA Group AG
Continentale Parker Ste
Continentale Parker SA
Original Assignee
Metallgesellschaft AG
Continentale Parker Ste
Continentale Parker 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 Metallgesellschaft AG, Continentale Parker Ste, Continentale Parker SA filed Critical Metallgesellschaft AG
Publication of EP0042631A1 publication Critical patent/EP0042631A1/fr
Application granted granted Critical
Publication of EP0042631B1 publication Critical patent/EP0042631B1/fr
Expired legal-status Critical Current

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23CCOATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C22/00Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C22/05Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
    • C23C22/06Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
    • C23C22/34Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing fluorides or complex fluorides
    • C23C22/36Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing fluorides or complex fluorides containing also phosphates
    • C23C22/364Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing fluorides or complex fluorides containing also phosphates containing also manganese cations
    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23CCOATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C22/00Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C22/05Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
    • C23C22/06Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
    • C23C22/07Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing phosphates
    • C23C22/08Orthophosphates
    • C23C22/18Orthophosphates containing manganese cations
    • C23C22/182Orthophosphates containing manganese cations containing also zinc cations
    • C23C22/184Orthophosphates containing manganese cations containing also zinc cations containing also nickel cations

Definitions

  • the invention relates to a process for the production of phosphate coatings on metal surfaces of iron and steel using an acidic nitrate-accelerated zinc and manganese ion-containing phosphating solution at elevated temperatures in the immersion process.
  • z. B. in the range between 8 to 30 g / m 2 required.
  • particularly high demands are placed on corrosion protection. This can be achieved by increasing the layer weight.
  • An increase in the layer weight would also allow higher degrees of deformation in cold forming.
  • the deposition of thick zinc phosphate layers can according to DE-AS 12 87 412 and US Pat. No. 3,268,367 by bringing iron and steel into contact with a nitrate-accelerated acidic zinc phosphating solution with the addition of polycarboxylic acids in which the carbon atom adjacent to at least one carboxyl group is a hydroxy -, Amino or carboxyl group can be achieved.
  • This phosphating solution can also contain additives such as nickel, cobalt, lithium, bismuth and manganese in small concentrations of less than 0.5 g / l. They activate the metal surface to be phosphated and promote the deposition of zinc phosphate layers.
  • the object of the invention is to provide a phosphating process which does not have the disadvantages described, in particular is universally applicable, requires little chemicals and leads to higher-quality phosphate layers.
  • the object is achieved by designing the method of the type mentioned at the outset in accordance with the invention in such a way that the metal surfaces are brought into contact with a phosphating solution which contains at least 0.6 g / l of manganese ions at treatment temperatures of 50 to 98 ° C. in which the weight ratio is and which has a total acid score of at least 20 points when incorporated.
  • Such a method leads to zinc-manganese-phosphate layers which, with comparable layer thicknesses, are superior to zinc phosphate layers with regard to corrosion protection and cold-forming properties.
  • the metal surfaces are preferably brought into contact with a phosphating solution in which the manganese ion content is at least 1 g / l.
  • the metal surfaces are brought into contact with a phosphating solution in which the weight ratio of Mn: Zn is 1: (0.8 to 12).
  • Manganese ion contents in the phosphating solution above the range of 1: 0.2 lead to non-closed, perforated layers.
  • baths with e.g. 80 total acid points can be composed as follows:
  • the total acid number can be determined by titration of a 10 ml bath sample with 0.1 N NaOH against phenolphthalein as an indicator until the color changes from colorless to pink.
  • nickel and / or cobalt and / or copper ions and the like can be added to the bath.
  • these metal ions in a concentration of z. B. 0.02 to 0.10 g / l added to the bath.
  • the anion belonging to the metal ions can e.g. B. nitrate or sulfate.
  • a phosphating solution which contains simple and / or complex fluorides, such as NaF, NaHF 2 and / or Na 2 SiF 6 .
  • a certain reduction in the layer weight can be brought about if condensed phosphates are added to the phosphating bath.
  • the workpieces to be phosphated should be free of grease, scale and rust.
  • the degreasing can e.g. B. by means of aqueous, alkaline, surface-active substances containing cleaners.
  • Descaling is advantageously carried out using sulfuric acid or hydrochloric acid.
  • the workpieces After cleaning and / or pickling, the workpieces should be rinsed well with water.
  • the workpieces can be formed in a manner known per se, e.g. B. with titanium orthophosphate or manganese orthophosphate suspensions in water. It has been found in practice that in some cases a pre-rinse with water at 50 to 98 ° C activates the surface.
  • the phosphating bath is operated between 50 and 98 ° C depending on the type of workpiece, the alloy and the type of application. It has been shown that a diving time of 5 to 15 minutes is sufficient for most applications.
  • iron II will accumulate in the phosphating bath in the course of the throughput. This does not affect the way the bath works. In special cases, e.g. B. at high nitrate concentrations or at high bath temperatures, it can also happen that the bath remains iron-II-free due to the oxidation of FeII to FeIII. This also does not affect the way the bath works.
  • the addition of the bath is expediently carried out on a constant total acid number.
  • the layer weight of the zinc-manganese-phosphate layers obtained is normally between about 5 and about 30 g / m 2, depending on the composition of the phosphating bath and the alloy of the workpiece to be treated.
  • z. B. be treated with chromic acid solutions, followed by treatment with anti-corrosion oil emulsions.
  • the workpieces can e.g. B. be treated with soap solutions.
  • the workpieces treated in this way are superior to the workpieces treated with conventional nitrate accelerated zinc phosphating systems in terms of corrosion protection and cold forming properties.
  • baths F and G The composition of baths F and G is shown in the following table.
  • the total acid number of baths was 90 points each.
  • sample sheets became branched off to determine the layer weight and for the corrosion test in the salt spray test according to DIN 50021 SS.
  • the sheets for the corrosion test were previously treated with a 15% emulsion of an anti-corrosion oil and then dried in an oven at 70 ° C. It can be clearly seen that the preferred configuration of the supplement means that the phosphating baths, even after a throughput of 4 m 2 / l, lead to layers which have retained their good properties.

Landscapes

  • Chemical & Material Sciences (AREA)
  • General Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Chemical Treatment Of Metals (AREA)
EP81200442A 1980-06-24 1981-04-17 Procédé de phosphatation de surfaces métalliques Expired EP0042631B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3023479 1980-06-24
DE19803023479 DE3023479A1 (de) 1980-06-24 1980-06-24 Phosphatierverfahren

Publications (2)

Publication Number Publication Date
EP0042631A1 true EP0042631A1 (fr) 1981-12-30
EP0042631B1 EP0042631B1 (fr) 1984-10-31

Family

ID=6105254

Family Applications (1)

Application Number Title Priority Date Filing Date
EP81200442A Expired EP0042631B1 (fr) 1980-06-24 1981-04-17 Procédé de phosphatation de surfaces métalliques

Country Status (6)

Country Link
EP (1) EP0042631B1 (fr)
DE (2) DE3023479A1 (fr)
ES (1) ES502507A0 (fr)
GB (1) GB2078788B (fr)
IT (1) IT1137254B (fr)
PT (1) PT73117B (fr)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0106459A1 (fr) * 1982-08-24 1984-04-25 HENKEL CORPORATION (a Delaware Corp.) Phosphatation de surfaces métalliques
EP0172806A1 (fr) * 1984-01-06 1986-03-05 Ford Motor Company Revetement de conversion de phosphate a resistance alcaline
EP0186823A2 (fr) * 1984-12-20 1986-07-09 HENKEL CORPORATION (a Delaware corp.) Procédé pour faciliter la déformation à froid
US4681641A (en) * 1982-07-12 1987-07-21 Ford Motor Company Alkaline resistant phosphate conversion coatings
EP0298827A1 (fr) * 1987-06-25 1989-01-11 Roquette FrÀ¨res Solution et procédé de phosphatation mixte
US5039361A (en) * 1988-12-02 1991-08-13 Metallgesellschaft Aktiengesellschaft Process of phosphating metal surfaces
US5234509A (en) * 1984-12-20 1993-08-10 Henkel Corporation Cold deformation process employing improved lubrication coating
WO1996009422A1 (fr) * 1994-09-23 1996-03-28 Henkel Kommanditgesellschaft Auf Aktien Procede de phosphatage sans rinçage final
WO2001023638A1 (fr) * 1999-09-30 2001-04-05 Chemetall Gmbh Procede pour appliquer des couches de phosphate de manganese
US9506151B2 (en) 1999-09-30 2016-11-29 Chemetall Gmbh Method for applying manganese phosphate layers

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6342107B1 (en) * 1982-08-24 2002-01-29 Henkel Corporation Phosphate coatings for metal surfaces
DE3636390A1 (de) * 1986-10-25 1988-04-28 Metallgesellschaft Ag Verfahren zur erzeugung von phosphatueberzuegen auf metallen
DE10010355A1 (de) * 2000-03-07 2001-09-13 Chemetall Gmbh Verfahren zum Aufbringen eines Phosphatüberzuges und Verwendung der derart phosphatierten Metallteile

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2716709A1 (de) * 1976-04-19 1977-11-03 Nippon Paint Co Ltd Verfahren zur phosphatierung von eisen und stahl
US4086103A (en) * 1975-08-13 1978-04-25 Kevin James Woods Accelerator for phosphating solutions
DE2818426A1 (de) * 1977-05-03 1978-11-09 Metallgesellschaft Ag Verfahren zum aufbringen eines phosphatueberzuges auf metalloberflaechen
US4180417A (en) * 1977-10-12 1979-12-25 Nippon Paint Co., Ltd. Phosphating of metallic substrate

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1287412B (de) * 1963-11-30 1969-01-16 Metallgesellschaft Ag Verfahren zur Verbesserung der Korrosionsbestaendigkeit durch Herstellung von Phosphatueberzuegen erhoehten Schichtgewichts auf Oberflaechen aus Eisen und Stahl

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4086103A (en) * 1975-08-13 1978-04-25 Kevin James Woods Accelerator for phosphating solutions
DE2716709A1 (de) * 1976-04-19 1977-11-03 Nippon Paint Co Ltd Verfahren zur phosphatierung von eisen und stahl
DE2818426A1 (de) * 1977-05-03 1978-11-09 Metallgesellschaft Ag Verfahren zum aufbringen eines phosphatueberzuges auf metalloberflaechen
US4180417A (en) * 1977-10-12 1979-12-25 Nippon Paint Co., Ltd. Phosphating of metallic substrate

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4681641A (en) * 1982-07-12 1987-07-21 Ford Motor Company Alkaline resistant phosphate conversion coatings
EP0106459A1 (fr) * 1982-08-24 1984-04-25 HENKEL CORPORATION (a Delaware Corp.) Phosphatation de surfaces métalliques
EP0172806A1 (fr) * 1984-01-06 1986-03-05 Ford Motor Company Revetement de conversion de phosphate a resistance alcaline
EP0172806A4 (fr) * 1984-01-06 1986-05-16 Ford Motor Co Revetement de conversion de phosphate a resistance alcaline.
US5234509A (en) * 1984-12-20 1993-08-10 Henkel Corporation Cold deformation process employing improved lubrication coating
EP0186823A2 (fr) * 1984-12-20 1986-07-09 HENKEL CORPORATION (a Delaware corp.) Procédé pour faciliter la déformation à froid
EP0186823A3 (en) * 1984-12-20 1988-04-27 Parker Chemical Company Process for facilitating cold-forming
EP0298827A1 (fr) * 1987-06-25 1989-01-11 Roquette FrÀ¨res Solution et procédé de phosphatation mixte
US5045130A (en) * 1987-06-25 1991-09-03 Compagnie Francaise De Produits Industriels Solution and process for combined phosphatization
FR2618164A1 (fr) * 1987-06-25 1989-01-20 Roquette Freres Solution et procede de phosphatation mixte.
US5039361A (en) * 1988-12-02 1991-08-13 Metallgesellschaft Aktiengesellschaft Process of phosphating metal surfaces
WO1996009422A1 (fr) * 1994-09-23 1996-03-28 Henkel Kommanditgesellschaft Auf Aktien Procede de phosphatage sans rinçage final
US5976272A (en) * 1994-09-23 1999-11-02 Henkel Kommanditgesellschaft Auf Aktien No-rinse phosphating process
WO2001023638A1 (fr) * 1999-09-30 2001-04-05 Chemetall Gmbh Procede pour appliquer des couches de phosphate de manganese
US9506151B2 (en) 1999-09-30 2016-11-29 Chemetall Gmbh Method for applying manganese phosphate layers

Also Published As

Publication number Publication date
ES8305052A1 (es) 1983-04-16
ES502507A0 (es) 1983-04-16
EP0042631B1 (fr) 1984-10-31
DE3023479A1 (de) 1982-01-14
IT1137254B (it) 1986-09-03
PT73117B (fr) 1982-07-15
GB2078788B (en) 1984-10-03
GB2078788A (en) 1982-01-13
DE3166907D1 (en) 1984-12-06
PT73117A (fr) 1981-07-01
IT8122510A0 (it) 1981-06-23

Similar Documents

Publication Publication Date Title
EP0304108B1 (fr) Procédé de phosphatation de métaux
DE3879099T2 (de) Verfahren und zusammensetzung zur herstellung von zinkphosphatueberzuegen.
EP0214571B1 (fr) Procédé pour la formation de couches de conversion sur du zinc et/ou sur des alliages de zinc
DE972727C (de) Verfahren zur Behandlung von Metalloberflaechen vor dem Aufbringen von UEberzuegen
DE69108087T2 (de) Phosphatierverfahren für Metalloberflächen zur Herstellung von einem Zinkphosphatüberzug.
EP0042631B1 (fr) Procédé de phosphatation de surfaces métalliques
DE3689442T2 (de) Saure, wässrige Phosphatüberzugslösungen für ein Verfahren zum Phosphatbeschichten metallischer Oberfläche.
EP0045110B1 (fr) Procédé pour la production de revêtements de phosphate sur les surfaces de fer et d'acier et son usage
EP0478648B1 (fr) Procede de production d'enduits en phosphate de zinc contenant du manganese et du magnesium
DE69511393T2 (de) Polymerzusammensetzung und verfahren zur behandlung von metalloberflächen
EP0261704B1 (fr) Procédé pour produire des revêtements de phosphate sur des surfaces métalliques
DE3234558A1 (de) Waessrig-saure zinkphosphat-ueberzugsloesungen, solche loesungen verwendende tieftemperatur-verfahren zur bildung chemischer umwandlungsueberzuege auf eisen- und/oder zinkoberflaechen und darin verwendbare ueberzugskonzentrate und titanhaltige metallaktivierende loesungen
DE2552122A1 (de) Waessrige, saure zinkphosphatierloesung und ihre verwendung zur herstellung von zinkphosphatumwandlungsueberzuegen
EP0359296B1 (fr) Procédé de phosphatation
WO2017186931A1 (fr) Procédé de traitement anticorrosion d'une surface métallique à enlèvement réduit de matière décapée
EP0324395B1 (fr) Procédé de phosphatisation de surfaces métalliques
DE4228470A1 (de) Verfahren zur Phospatierung von einseitig verzinktem Stahlband
EP0486576B1 (fr) Procede pour la realisation de revetements de phosphate de zinc comportant du manganese sur de l'acier galvanise
EP0111223B1 (fr) Procédé de phosphatation de surfaces métalliques et compositions appropriées à ce procédé
DE69106678T2 (de) Verfahren zur Behandlung von metallischen Oberflächen.
EP0213590B1 (fr) Procédé pour la formation de couches de conversion sur du zinc et/ou sur des alliages zinc-aluminium
DE3780078T2 (de) Korrosionsbestaendige beschichtung.
DE4232292A1 (de) Verfahren zum Phosphatieren von verzinkten Stahloberflächen
DE3630246A1 (de) Verfahren zur erzeugung von phosphatueberzuegen sowie dessen anwendung
DE2540685C2 (de) Verfahren zur Herstellung von Phosphatüberzügen

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

Designated state(s): BE DE FR NL SE

17P Request for examination filed

Effective date: 19820210

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Designated state(s): BE DE FR NL SE

REF Corresponds to:

Ref document number: 3166907

Country of ref document: DE

Date of ref document: 19841206

ET Fr: translation filed
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
EAL Se: european patent in force in sweden

Ref document number: 81200442.2

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

Ref country code: FR

Payment date: 19980313

Year of fee payment: 18

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

Ref country code: DE

Payment date: 19980318

Year of fee payment: 18

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

Ref country code: SE

Payment date: 19980320

Year of fee payment: 18

Ref country code: NL

Payment date: 19980320

Year of fee payment: 18

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

Ref country code: BE

Payment date: 19980326

Year of fee payment: 18

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

Ref country code: DE

Free format text: LAPSE BECAUSE OF THE APPLICANT RENOUNCES

Effective date: 19990322

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: 19990418

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: 19990430

BERE Be: lapsed

Owner name: SOC. CONTINENTALE PARKER

Effective date: 19990430

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: 19991101

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: 19991231

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

Effective date: 19991101

EUG Se: european patent has lapsed

Ref document number: 81200442.2

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST