EP0215649B1 - Mehrfachbeschichtung einer Anode mit Platin/ECA-1500 für bei elektrochemischem Verfahren mit niedrigem pH und hoher Stromdichte verwendeten Anoden - Google Patents

Mehrfachbeschichtung einer Anode mit Platin/ECA-1500 für bei elektrochemischem Verfahren mit niedrigem pH und hoher Stromdichte verwendeten Anoden Download PDF

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Publication number
EP0215649B1
EP0215649B1 EP86307039A EP86307039A EP0215649B1 EP 0215649 B1 EP0215649 B1 EP 0215649B1 EP 86307039 A EP86307039 A EP 86307039A EP 86307039 A EP86307039 A EP 86307039A EP 0215649 B1 EP0215649 B1 EP 0215649B1
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EP
European Patent Office
Prior art keywords
anode
platinum
temperature
micrometers
microinches
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
EP86307039A
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English (en)
French (fr)
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EP0215649A1 (de
Inventor
Mark J. Geusic
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BASF Catalysts LLC
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Engelhard Corp
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Publication date
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Priority to AT86307039T priority Critical patent/ATE60374T1/de
Publication of EP0215649A1 publication Critical patent/EP0215649A1/de
Application granted granted Critical
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Classifications

    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
    • C25C7/00—Constructional parts, or assemblies thereof, of cells; Servicing or operating of cells
    • C25C7/02—Electrodes; Connections thereof
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
    • C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
    • C25B11/051—Electrodes formed of electrocatalysts on a substrate or carrier
    • C25B11/073—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material
    • C25B11/091—Electrodes 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
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D17/00—Constructional parts, or assemblies thereof, of cells for electrolytic coating
    • C25D17/10—Electrodes, e.g. composition, counter electrode

Definitions

  • Electroformed copper foils are the backbone of modern electronic devices. As integrated circuits have found their way into ever increasing numbers of products, the quantity of foil required has increased correspondingly yet the rate at which these foils could be produced has been limited because even the best dimensionally stable anodes available were not capable of withstanding the conditions required for optimum foil production.
  • EP-A-0090425 discloses an electrode which is formed by depositing a porous coating of platinum onto a titanium substrate and then forming iridium oxide in and over said platinum coating.
  • the anodes of the present invention are particularly suitable for producing high purity, pore-free copper foils at high speed and low cost under severe conditions because these anodes withstand high acid concentrations, current densities and temperatures which would rapidly destroy the anodes known in the prior art.
  • the anodes of the present invention are formed by a three step process which is extremely sensitive in its details but, when carried out properly, produces extremely robust and durable anodes.
  • platinum is electrodeposited on a valve metal substrate which has been thoroughly descaled, degreased and cleaned. It is critical that the platinum be applied to a thickness of from at least about 3.8 micrometers (150 microinches) up to 10.2 micrometers (400 microinches), preferably the thickness will be at least about 5.7 micrometers (225 microinches), more preferably at least about 6.35 micrometers (250 microinches).
  • the second step of the process involves a thermal treatment referred to as "densification” which is essential for obtaining the anodes of the present invention.
  • the platinum coated anode is heated in air and maintained at a temperature between 600 and 775°C for about 1/4 to 2 hours or until the stress is relieved in the electrodeposited coating and pores resulting from the electrodeposition process have closed.
  • the final step in the process is applying a catalytic oxide outer coating consisting essentially of at least about 97% IrO2 and up to about 3% Rh2O3 by applying thermally decomposable iridium and rhodium compounds to the "densified" platinum coated substrate, then decomposing the compounds by heating in air to form the oxides. It has been found that it is essential to effect the decomposition at temperatures of no more than about 600°C as the products formed are much less durable when higher temperatures (for example, around 690°C) are used.
  • the amount of the thermally decomposable compounds applied should be sufficient to provide a loading of at least about 15 m2/g of iridium (calculated based on the weight of the metal), preferably 20 m2/g, more preferably 25 m2/g.
  • the substrates to which the coating is applied may be any of the well known film forming metals which, if uncoated, will rapidly passivate by formation of an adherent protective oxide film in the electrolyte for which the anode is intended.
  • Typical substrates are formed from titanium, tantalum, vanadium, tungsten, aluminum, zirconium, niobium and molybdenum in the form of tubes, rods, sheets, meshes, expanded metals or other specialized shapes for specific applications.
  • anodes in the shape of cylinders or as a portion of a cylinder which conform to the shape of the mandrel or drum so that the electrolytically formed foil will be of uniform thickness and may easily be removed from the cathode drum.
  • the core of the anode will be copper or another highly conductive metal such as aluminum or highly conductive ferrous alloys clad with a film forming metal outer layer such as titanium.
  • the substrate Prior to application of the electrolytic layer, the substrate is cleaned and descaled such as by blasting with aluminum oxide particles in an air jet, then chemically cleaned and degreased. Normally, the anode is coated immediately subsequent to degreasing but the anodes may be stored for a few days between degreasing and coating without ill effect.
  • the electrolytic coating of platinum may be applied by immersing the substrate in an aqueous, platinum, electroplating bath opposite a conventional dimensionally stable conterelectrode and passing a current of from about 15 to about 150 A/m2 (about 7 to about 70 amps per square foot) through the substrate until at least 3-8 micrometers, preferably 5-1 micrometers, more preferably 6-35 micrometers (at least 150, preferably 225, more preferably 250 microinches) of platinum have been applied. Any conventional platinum electroplating bath may be used.
  • Such baths are in aqueous dispersons, solutions or admixtures containing compounds of platinum such as ammine, nitrito or hydroxy complexes, as well as various known additives for brightening, improving the ductility of the deposited film and isolating impurities as well as improving the conductivity of the bath.
  • Typical platinum compounds include H2PtCl6, K2Pt(OH2), H2Pt(NO2)2SO4 and diammine dinitroplatinum (II).
  • Useful formulations for platinum electroplating baths are disclosed in F. Lowenheim, Modern Electroplating , 3rd Ed. 1974, pp. 355-357 and F. Lowenheim, Electroplating , McGraw Hill 1978, pp. 298-299. Prepared concentrates for preparing and replenishing platinum electroplating baths are commercially available.
  • the temperature of the bath should preferably be maintained at from about 150 to about 200°F (65° to 93°C).
  • the anode may be removed from the bath and subjected to a thermal treatment termed "densification" to stress relieve the coating and close pores therein by heat treating in on oxygen containing atmosphere. If the "densification” step is omitted, or not performed properly, the anodes formed are less durable as they passivate prematurely.
  • Thermal densification can be accomplished by heating the platinum coated anode in air, nitrogen, helium, vacuum or any convenient atmosphere to a temperature of between about 550°C and 850°C for from about 15 minutes to several hours depending on the nature of the as deposited platinum film. It may be determined that the thermal densification step is complete by visually observing the coating and noting when pore closure occurs and the coating becomes much more highly reflective.
  • the anode may be cooled then coated with an iridium oxide outer layer by thermal decomposition of iridium containing compounds in an oxygen containing atmosphere.
  • Iridium compounds that may be used include hexachlororidic acid (NH4)2IrCl6 and IrCl4, as well as iridium resinates and other halogen containing compounds.
  • NH42IrCl6 and IrCl4 hexachlororidic acid
  • iridium resinates and other halogen containing compounds Typically, these compounds are dispersed in any convenient carrier such as isobutanol, and other aliphatic alcohols, then applied to the substrate by any convenient method such as dipping, brushing on or spraying.
  • an amount of iridium bearing carrier is applied which is sufficient to deposit a loading of from about 0.5 to about 3.0 grams per square meter, preferably 1 to 2 grams per square meter, of iridium (calculated as metal) on the substrate, which is then fired in air at from about 400°C to no more than about 550°C, preferably 450°C to about 500°C, to drive off the carrier and convert the iridium compounds to the oxides. This procedure is repeated until the total amount of iridium applied is at least about 15, preferably at least about 20, more preferably at least about 25 grams per square meter (calculated as metal).
  • the temperature of the thermal decomposition step is extremely critical.
  • the resulting anode when a decomposition temperature in excess of about 600°C is used for decomposition of the iridium compounds, the resulting anode is much less durable, but when the iridium compound is decomposed at temperatures of 600°C or below, preferably from about 400°C to about 550°C, more preferably from 450°C to 500°C, the resulting anode is surprisingly durable and long lived even when evolving oxygen in baths at temperatures in excess of about 65°C which will normally ruin the prior art anodes in short order.
  • Rh2O3 in the iridium oxide film to promote adhesion. This may be accomplished by incorporation of any convenient, conventional rhodium compound into the iridium bearing coating composition. Rhodium resinates are particularly convenient.
  • Copper foils may be electroformed using the anodes of the present invention by immersing the anode in a bath at a pH of from -2 to 3 containing suitable copper species such as copper sulfate, copper chloride and other soluble copper compounds opposite a cathode such as stainless steel or other corrosion resistant alloys and passing a current of from about 400 to about 2,000 amps per square foot of anode (4,300 to 21,000 A/m2) through the bath and evolving oxygen at the anode. It is considered particularly surprising that the anodes of the present invention exhibit high durability even when used at bath temperatures in excess of 65°C up to about 90°C.
  • anodes of the present invention remain suitable for use at a sulfuric acid concentration from about 100 to about 250 grams/liter even when operating at current densities from about 500 up to about 3,000 amps per square foot (5,400 to 32,000 A/m2). Under these conditions, prior art anodes rapidly become useless and even anodes similar to the present invention, but not prepared strictly in accordance therewith, fail rapidly. It is extremely desirable for copper foil producers to be able to use these severe conditions as under these conditions more efficient, rapid and economical production of foil can be achieved.
  • the anodes of the present invention satisfy a long felt but unsatisfied need for anodes which were capable of being used under conditions which are suitable for high speed, energy efficient production of high purity, pore free films of electrolytic copper foil. They are also extremely suitable for those applications in which a porous foil is desired as well as for other applications involving oxygen evolution such as electrogalvanizing, electrowinning and electrosynthesis.
  • This Example illustrates the production of an anode in accordance with the present invention.
  • a substrate of titanium of dimension 10.16 ⁇ 20.32 ⁇ 0.158 cm (4" by 8" by 0.062”) was descaled, cleaned and degreased, then electrolytically coated with platinum to a thicknesss of 6.35 micrometers (250 microinches). The platinum coating was then densified by heating in air at 690°C for 3/4 hour.
  • a coating consisting of about 98% IrO2 and 2% Rh2O3 was applied by painting the substrate with a solution of hexachlororidic acid and a rhodium resinate dispersed in butanol, then firing in air at 450°C and repeating this procedure 15 times until the coating weight reached 15 grams of iridium (as metal) per square meter.
  • iridium as metal
  • Example 1 The procedure of Example 1 was repeated except that the iridium oxide (third step) was formed at 690°C. When used under conditions similar to those in Example 1 (pH 0, current density 1860, and temperature of 60°C) the anode failed after 620 hours.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Electrolytic Production Of Metals (AREA)
  • Electroplating And Plating Baths Therefor (AREA)
  • Electroplating Methods And Accessories (AREA)
  • Chemically Coating (AREA)
  • Electrodes For Compound Or Non-Metal Manufacture (AREA)

Claims (6)

1. Anode zur Sauerstoffentwicklung, im wesentlichen bestehend aus einem Sub­strat aus einem filmbildenden Metall mit einem darauf befindlichen Mehr­schichtüberzug, wobei wenigstens eine Innenschicht im wesentlichen aus weitgehend porenfreiem Platin besteht, das elektrolytisch in einer Stärke von wenigstens 3,8 µm (150 Mikrozoll) aufgebracht und dann durch Wärmebe­handlung in einer Sauerstoff-enthaltenden Atmosphäre bei 600 bis 775°C ver­dichtet worden ist, um die Poren der Platinscht auszufüllen;
und wobei wenigstens eine der Außenschichten im wesentlichen aus wenigstens 97% Iridiumoxid und bis zu 3% Rhodiumoxid besteht, welche Außenschicht durch thermische Zersetzung von thermisch zersetzbaren Platingruppenmetallverbindungen in einer Sauerstoff enthaltenden Atmosphäre bei einer nicht über 600°C liegenden Temperatur aufgebracht worden ist.
2. Anode nach Anspruch 1, worin die Außenschicht durch thermische Zersetzung bei einer Temperatur von 400 bis 550°C gebildet wird.
3. Anode nach Anspruch 1, worin die Innenschicht eine Stärke von wenigstens 5,7 µm (225 Mikrozoll) aufweist.
4. Anode nach Anspruch 1, worin die Innenschicht eine Stärke von wenigstens 6,35 µm (250 Mikrozoll) aufweist.
5. Anode narh Anspruch 4, worin die Außensicht durch thermische Zersetzung bei einer Temperatur von 450 bis 500°C gebildet wird.
6. Verfahren zur Elektroformung von Kupferfolie in einem wäßrigen Bad, das über 100 g je Liter Schwefelsäure enthält, unter Anwendung einer Stromdichte von wenigstens 5.380 A/m² (500 A je Quadratfuß) bei einer Temperatur von über 65°C, wobei die Anode nach einem der Ansprüche 1 bis 5 angewendet wird.
EP86307039A 1985-09-13 1986-09-12 Mehrfachbeschichtung einer Anode mit Platin/ECA-1500 für bei elektrochemischem Verfahren mit niedrigem pH und hoher Stromdichte verwendeten Anoden Expired - Lifetime EP0215649B1 (de)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT86307039T ATE60374T1 (de) 1985-09-13 1986-09-12 Mehrfachbeschichtung einer anode mit platin/eca- 1500 fuer bei elektrochemischem verfahren mit niedrigem ph und hoher stromdichte verwendeten anoden.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US77591185A 1985-09-13 1985-09-13
US775911 1985-09-13

Publications (2)

Publication Number Publication Date
EP0215649A1 EP0215649A1 (de) 1987-03-25
EP0215649B1 true EP0215649B1 (de) 1991-01-23

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EP86307039A Expired - Lifetime EP0215649B1 (de) 1985-09-13 1986-09-12 Mehrfachbeschichtung einer Anode mit Platin/ECA-1500 für bei elektrochemischem Verfahren mit niedrigem pH und hoher Stromdichte verwendeten Anoden

Country Status (5)

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EP (1) EP0215649B1 (de)
JP (1) JPH0735597B2 (de)
AT (1) ATE60374T1 (de)
CA (1) CA1305447C (de)
DE (1) DE3677108D1 (de)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3124848B2 (ja) * 1992-11-11 2001-01-15 ペルメレック電極株式会社 金属箔の電解による製造方法
TWI490371B (zh) * 2009-07-28 2015-07-01 Industrie De Nora Spa 電解應用上的電極及其製法以及在電極表面上陽極釋氧之電解法和電冶法

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4203810A (en) * 1970-03-25 1980-05-20 Imi Marston Limited Electrolytic process employing electrodes having coatings which comprise platinum
CH563464A5 (en) * 1970-09-02 1975-06-30 Engelhard Min & Chem Electrolytic anode
JPS5647597A (en) * 1979-09-25 1981-04-30 Nippon Steel Corp Insoluble electrode for electroplating and preparation thereof
GB2060701B (en) * 1979-10-12 1983-06-08 Diamond Shamrock Corp Electrode coating with platinum- group metal catalyst and semiconducting polymer
JPS56147057A (en) * 1980-04-15 1981-11-14 Ngk Spark Plug Co Ltd Production of oxygen sensor
CA1225066A (en) * 1980-08-18 1987-08-04 Jean M. Hinden Electrode with surface film of oxide of valve metal incorporating platinum group metal or oxide
US4331528A (en) * 1980-10-06 1982-05-25 Diamond Shamrock Corporation Coated metal electrode with improved barrier layer
JPS58171589A (ja) * 1982-03-31 1983-10-08 Ishifuku Kinzoku Kogyo Kk 電解用電極及びその製造方法
GB8316778D0 (en) * 1983-06-21 1983-07-27 Ici Plc Cathode

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN, unexamined application, E section, vol. 1, no. 37, April 18, 1977 THE PATENT OFFICE JAPANESE GOVERNMENT, page 2034 E 76, Kokai-no. 51-133 789 (KIYOTERU TAKAYASU) *

Also Published As

Publication number Publication date
EP0215649A1 (de) 1987-03-25
ATE60374T1 (de) 1991-02-15
JPS6280298A (ja) 1987-04-13
DE3677108D1 (de) 1991-02-28
CA1305447C (en) 1992-07-21
JPH0735597B2 (ja) 1995-04-19

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