EP0648863B1 - Enamellable oxide layer - Google Patents

Enamellable oxide layer Download PDF

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Publication number
EP0648863B1
EP0648863B1 EP94810572A EP94810572A EP0648863B1 EP 0648863 B1 EP0648863 B1 EP 0648863B1 EP 94810572 A EP94810572 A EP 94810572A EP 94810572 A EP94810572 A EP 94810572A EP 0648863 B1 EP0648863 B1 EP 0648863B1
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EP
European Patent Office
Prior art keywords
aluminium
enamel
substrate
layer
surface layer
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
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EP94810572A
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German (de)
French (fr)
Other versions
EP0648863B2 (en
EP0648863A1 (en
Inventor
Jean-François Paulet
Hermann Weber
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3A Composites International AG
Original Assignee
Alusuisse Lonza Services Ltd
Alusuisse Technology and Management Ltd
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Application filed by Alusuisse Lonza Services Ltd, Alusuisse Technology and Management Ltd filed Critical Alusuisse Lonza Services Ltd
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Classifications

    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D11/00—Electrolytic coating by surface reaction, i.e. forming conversion layers
    • C25D11/02—Anodisation
    • C25D11/04—Anodisation of aluminium or alloys based thereon
    • C—CHEMISTRY; METALLURGY
    • C23—COATING 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
    • C23D—ENAMELLING OF, OR APPLYING A VITREOUS LAYER TO, METALS
    • C23D3/00—Chemical treatment of the metal surfaces prior to coating

Definitions

  • the invention relates to an aluminum-containing substrate for enamel coatings containing at least on the surfaces provided for an enamel coating, a surface layer made of aluminum or an aluminum alloy and on this surface layer Oxide layer.
  • the invention further relates to a method for producing the oxide layer and the use of the aluminum-containing substrate.
  • Aluminum materials such as foils, strips or sheets, for example used as facade panels for facade and vehicle construction. Such cover plates are in usually anodized to be resistant to environmental influences.
  • Alignment 54th year, 1978, volume 8, pages 527 and 528, W. Grosskopf, "overview about the application and implementation of the enamelling of aluminum ", is the enamelling of pure aluminum strips up to 0.3 mm thick. It was not found any aluminum material can be enamelled, and in particular magnesium-containing aluminum alloys are unsuitable for enamelling.
  • UDSSR patent specification 1 120 034 A describes a process for enamelling aluminum alloys described, wherein the alloy is anodized and the anodized article coated with a sample of an enamel powder, dried and baked the enamel, around a decorative surface resp. to get a decorative pattern.
  • Finishing Publication Ltd., Teddington, Middlesex, England, 5th edition, volume 2, 1987, page 1162 describes that on the one hand the worst results from the application of an enamel layer on one anodized aluminum would be achieved, on the other hand, anodized aluminum again a show much better bonding and resistance to thermal shock. So far therefore the problem of adhering to an aluminum-containing substrate for a long time Enamel layer not loosened. It is always to be feared that such a layer will appear soon after replaces or flakes off the order.
  • the object of the present invention is to provide a substrate for To make available, which is suitable for the application of an enamel layer, as well to propose a method for producing the substrate and a use for the substrate.
  • the object is achieved by the product according to claim 1.
  • the method of manufacturing the product according to claim 1 is claimed in claim 9.
  • the uses of the product according to claim 1 are claimed in claims 12 to 14.
  • Advantageous embodiments of the product and the method are claimed in claims 2 to 8 or 10 and 11.
  • Aluminum-containing substrates are, for example, sheet-like substrates made of aluminum or its alloys. Examples are foils, strips, sheets or profiles. The substrates but can also bodies of any shape with an aluminum surface or an aluminum-containing Surface. Other substrates are composite materials that at least a cover layer made of aluminum or an aluminum alloy. Preferably are foils, strips or sheets made of aluminum or aluminum alloys applied.
  • the isotropic barrier layer can cover the entire surface of the aluminum or of the aluminum alloy extend or can be provided at least at the points to which the enamel coating should be applied.
  • the isotropic barrier layer is a pore-free oxide layer and has a high temperature resistance as well as increased compared to aluminum or aluminum alloys chemical resistance. Enamel layers generally show good adhesion to oxides. Through time- and temperature-dependent diffusion processes, however, components can on the one hand the enamel layer and on the other hand also components of the aluminum-containing substrate, such as metallic alloy components or impurities, in the oxide layer arrive and form a layer that does not adhere well to the enamel layer Guaranteed aluminum-containing substrate. Such components (adhesion inhibitors), the one Reduce adhesion and thus, for example, also cause spalling problems in the enamel layer can be, for example, copper or magnesium. The diffusion of such adhesion inhibitors takes place in the oxide layer, due to the high baking temperature, essentially during the firing process of the enamel coating.
  • Isotropic barrier layer prevents diffusion of adhesion inhibitors or at least in this way reduces that good adhesion of a deposited on the substrate according to the invention Enamel layer is guaranteed.
  • the density of the isotropic barrier layer is advantageously between 2.5 and 3.8 g / cm 3 and preferably has a dielectric constant between 8.5 and 10.
  • substrates with a surface layer made of pure aluminum, essentially containing aluminum and the commercially available impurities or made of aluminum alloys are examples of aluminum-containing substrates.
  • Aluminum substrates can, for example, be aluminum of a purity of 98.5% by weight and higher, preferably of 99.0% by weight and higher and in particular 99.5 wt .-% and higher, and the rest of commercial impurities contain.
  • Wrought aluminum alloys are preferred for the substrates.
  • Alloys include e.g. the types AlMg, AlMgSi, AlCuMg and AlZnMg.
  • wrought aluminum alloys can contain: Up to 1.5 % By weight silicon, up to 1.0% by weight iron, up to 4.0% by weight copper, up to 1.5% by weight of manganese, up to 6.0% by weight of magnesium, up to 7.0% by weight Zinc, up to 0.2% by weight of titanium and up to 1.6% by weight of other elements, Rest aluminum.
  • Substrates made of an aluminum alloy are particularly preferred, containing 0.25 to 1.5 wt .-% silicon, up to 0.3 wt .-% Iron, up to 0.25% by weight copper, 0.1 to 0.8% by weight manganese, 2.7 - 5.0 %
  • Examples from the practice of substrates are aluminum alloys AlMg3, AlMg3Si, AlMg5, AlMg5Si and AlMg10.
  • Aluminum casting alloys are also preferred for the substrates.
  • Alloys include e.g. the types: AlSi, AlSiMg, AlSiCuMg, AlMgSi-CuMg, AlMgSi and AlZnMg.
  • Cast aluminum alloys containing: up to 11.0% by weight silicon, up to 1.0% by weight iron, up to 5.2% by weight copper, up to 0.5% by weight Manganese, up to 7.5% by weight of magnesium, up to 10% by weight of zinc, up to 0.3 %
  • titanium up to 1.2% by weight nickel, up to 0.03% by weight lead, up to 0.03% by weight of tin and up to 0.05% by weight of other elements, the rest being aluminum.
  • the substrates can only use this aluminum or aluminum-containing surface layer and on this surface layer, at least partially, the have oxide layer according to the invention, or e.g. for the purpose of a composite or a laminate further aluminum-containing layers or layers of other materials on the back of the surface layer be arranged while the oxide layer according to the invention on the front is arranged.
  • the aluminum or aluminum-containing surface layer must be on the surface, so that the inventive Oxide layer in an appropriate manner on it. can be attached to it.
  • the inventive The oxide layer then forms the layer that is now exposed on the outside for further use Coating with the enamel layer.
  • the present invention also relates to a process for producing the aluminum-containing one Substrates for enamel coatings.
  • the method is carried out in such a way that that the oxide layer at least in the areas provided for the enamel coating by means of anodic oxidation (anodizing) in an electrolyte with a pH value in Range between 5 and 7 in the temperature range of 30 to 80 ° C is formed, with the anodic oxidation the surface layer of aluminum or an aluminum alloy or at least the area intended for the enamel coating in an electrolyte is given, and between the surface layer and a second, in the same electrolyte a voltage is applied to the electrode.
  • the aluminum-containing substrate or at least the areas provided for the enamel coating are placed in an electrolyte and be switched as a positive electrode (anode).
  • a negative electrode cathode
  • another electrode in the same electrolyte is used, for example stainless steel or lead. If an electrical voltage is applied to the electrodes, then hydrogen gas develops at the cathode, at the anode or in the electrolyte submerged aluminum-containing substrate oxygen gas. This oxygen reacts with the Aluminum to aluminum oxide, which forms an oxide layer on the surface layer.
  • the process of producing the oxide layer used in practice runs essentially so that the substrate and in particular the surface to be coated with enamel of aluminum or an aluminum alloy is subjected to a pretreatment, wherein the surface is first degreased, then rinsed and finally stained, with the pickling for example with a sodium hydroxide solution in a concentration of 50 to 200 g / l 40 to 60 ° can be carried out for one to ten minutes. Then can rinsed the surface and with an acid such as Nitric acid, especially a concentration of 25 to 35% by weight in the room temperature range of typically 20 - Neutralized at 25 ° C for 20-60 s, rinsed again and if necessary be dried.
  • an acid such as Nitric acid
  • the properties of the oxide layer formed largely depend on the Electrolysis conditions such as electrolyte composition, pH value, electrolyte temperature, applied voltage and the electrolysis current from.
  • electrolysis conditions such as electrolyte composition, pH value, electrolyte temperature, applied voltage and the electrolysis current from.
  • an acidic electrolyte one forms Oxide layer, which is essentially a non-porous base or barrier layer and contains a porous outer layer.
  • Oxide layer which is essentially a non-porous base or barrier layer and contains a porous outer layer.
  • anodic Oxidation in acidic electrolytes forms on the substrate surface a pore-free base or barrier layer and at the same time the during the anodic oxide layer formed on the outside partially dissolved chemically by field-induced redissolving.
  • an oxide layer with fine pores forms on the surface for example, perpendicular to the surface and against the surface are open.
  • the thickness of the oxide layer reaches its upper limit if growth and solution are balanced, what of the
  • pH-neutral or approximately pH-neutral electrolytes are solutions that have a pH in the range between 5 and 7.
  • Typical examples of such electrolytes are boric acid (H 3 BO 3 ) or aqueous solutions of ammonium salts with borates, phosphates, tartrates, citrates, vanadates or molybdate and mixtures thereof.
  • electrolytes such as aqueous solutions with 1% by weight NH 4 H 2 PO 4 (9% phosphate), 10% by weight H 3 BO 3 (7% borate), 5% by weight NH 4 molybdate (2.5% Mo oxide) or 2% by weight NH 4 vanadate (2% vanadium oxide), with the information in parentheses the compounds typical of the individual electrolytes in atomic percentages which are in the oxide layer and in particular to be built into their outer surface.
  • the surfaces to be treated come into contact with the electrolyte brought and by means of direct current, pulse current, alternating current or asymmetrical AC anodized. Also be under DC currents of practically the same type, for example through full-wave rectification a single-phase alternating current or by rectifying one Three-phase alternating current are generated, understood.
  • asymmetrical AC types can include, for example, sinusoidal AC a voltage / time curve with unequal amplitudes in the positive and negative part, rectangular alternating current with a Voltage / time curve with equally high amplitudes and unequal lengths Time shares of the positive and negative part, rectangular alternating current with a voltage / time curve with unequal amplitudes in the positive and negative range or rectangular alternating current with a voltage / time curve with unequal amplitudes and unequal long time portions of the positive and negative part can be applied.
  • sinusoidal alternating current curves with phase gating in positive and negative part and also other asymmetrical alternating currents be used with interrupted current flow, e.g. with triangular Alternating current.
  • the anodic oxidation in pH-neutral or approximately pH-neutral electrolytes is expediently carried out with a voltage up to 600 V, preferably up to 500 V, and a current density up to 120 A / m 2 , preferably up to 100 A / m 2 .
  • the anodic oxidation in pH-neutral or approximately pH-neutral electrolytes can be carried out, for example, by continuously increasing the applied voltage up to the maximum value such that the current density is kept constant at this level after an initially continuous increase up to the predetermined value. After reaching the maximum voltage, the current density then decreases due to the increasingly thick oxide layer and reaches a residual current density after a certain time.
  • the method according to the invention is preferably carried out until the current density has fallen to a value between 1 and 10 A / m 2 after the maximum voltage has been applied.
  • the thickness of the oxide layer obtained is voltage-dependent and lies in the range between 10 and 16 ⁇ / V and in particular between 11 and 15 ⁇ / V.
  • the oxide layer can have a small surface area Contain concentration of ions. This ion concentration becomes essentially determined by the electrolyte and is therefore on the outer Surface area of the oxide layer limited.
  • the inventive Oxide layer is particularly low in magnesium and prevents during and after the enamel coating has burned in, another diffusion of magnesium from the surface layer.
  • the substrate or the treated surface can other treatments, such as Rinsing or impregnation will.
  • Such an aftertreatment without rinsing is provided, for example, by Impregnation of the oxide surface with a flux.
  • a flux can contain compounds or ions, which are very important in enamel are easily soluble and therefore, for example, better enamel anchoring effect on the oxide surface.
  • the oxide surfaces can be such Compounds or ions, such as vanadium oxide, ammonium vanadate, Molybdenum oxide, ammonium molybdate, ammonium borate, ammonium phosphate etc. already contained by the anodic oxidation. In this case their effect is achieved by applying an appropriate flux supported. Fluxes can also affect the wettability of the oxide surface increase and / or lower the melting point of the enamel frit.
  • the present invention also relates to the use of the inventive Product as a substrate for enamel coatings.
  • the substrate according to the present invention for enamel coatings can be used as a melting point of 480 ° C to or near the melting point Melting point of the substrate can be used. With close to the melting point For example, temperatures between 20 or 10 ° C below the Melting point described.
  • the product is useful as a substrate for enamel coatings based on alkali-silico-titanates, if necessary with baking temperature-reducing additives, e.g. the connections, such as oxides, lithium, barium, antimony, cadmium, bismuth or Vanadium applied.
  • the present relates Invention the use of the product as a substrate for Enamel coatings from a frit containing the oxides of silicon in amounts of 27 to 33% by weight, preferably 30% by weight, of the potassium of 9 to 12% by weight, preferably 9.5 to 11.5% by weight, of the titanium from 18 to 22 %
  • the potassium of 9 to 12% by weight, preferably 9.5 to 11.5% by weight
  • the titanium from 18 to 22 %
  • 20 to 22% by weight of sodium from 18 to 22% by weight, preferably 20 to 22% by weight of the aluminum of 0.5 to 3.2% by weight, preferably 2.8 to 3.2% by weight of the lithium from 3.5 to 4.2% by weight is preferred 3.8 to 4.2% by weight of boron from 5 to 8% by weight, preferably 6.5 to 8% by weight of the zircon from 0.05 to 3% by weight, preferably from 2.3 to 3 %
  • the zinc from 0.8 to 2.0% by weight, preferably 0.8 to 1.5 %
  • the magnesium from 1 to 1.5% by weight,
  • Enamel coatings which are used as frit with additives on the Applied and by heat treatment or baking in a substrate
  • the enamel coating in turn, for example, from a mixture of oxides are generated in the specified proportions.
  • the oxides usually lie as a frit, i.e. as a mixture that was ground in front. This frit can in turn be used with processing aids such as for example boric acid, sodium metasilicate, potassium hydroxide, titanium dioxide and pigments are added.
  • Typical example of a frit composition contains: 100 parts frit, about 4 parts boric acid, one Part with sodium metasilicate, part with potassium hydroxide, five to fifteen Parts of titanium dioxide and one to seven parts of pigment.
  • the enamelling can, for example comprise a layer, a layer of a frit composition is applied to the substrate surface and in one firing process branded, i.e. is transferred into the enamel coating.
  • Further methods are also within the scope of the invention, according to which two Layers in two burns, three layers in three burns resp. multiple layers can be applied in multiple firing processes. Other methods of applying enamel layers are by applying of two or more frit layers or frit compositions with just one burn.
  • the frit can be, for example, a medium one Grain size of less than 74 microns and suitably less than 44 microns.
  • the frit can be sprinkled, sprayed, dipped or Slurries are applied. Electrostatic is another option Spraying or electrophoresis. Occasionally, the frit, if it was applied with a suspension aid such as water, be dried. After drying, the coated substrate can be in a furnace, the combustion process being continuous or can be done gradually. Typical burning times are between 3 and 10 minutes, with burn times between 3 and 6 minutes preferred will. Typical firing temperatures are between 480 and 560 ° C. All procedures can be carried out step by step or continuously will.
  • Oxide layers represent a substrate which is used for an enamel coating is particularly suitable since the wetting by the components of the Enamel coating in particular during the baking process is pronounced and thus the use of frits with lower Melting point, i.e. with a melting point of up to 20, for example ° C below the usual range.
  • the substrates according to the present invention with the enamel coatings have an extremely smooth surface. Thanks to the enamel coating is the substrate against mechanical, physical, chemical and actinic Influences and, for example, largely protected against environmental influences.
  • the surface is smooth, shiny and extremely hard.
  • the smooth surface can, for example, dirt, dyes, solvent-based Dyes or in a carrier medium Dyes do not penetrate pores and the appearance of the surface change or deface. The great hardness of the surface protects against Abrasion and other mechanical influences.
  • substrates with an enamel coating are suitable, for example in building construction as facade panels for indoor and outdoor applications, as an outer layer on composite panels for facades or for interior work, as cladding panels or body parts for vehicles, such as Railway wagons, buses and other road and rail vehicles and for Corrosive atmosphere applications. They are also suitable substrates coated with enamel according to the present invention for furniture in public areas such as poster pillars, letter boxes, Vending machine boxes and the like, e.g. due to vandalism an increased Are at risk.
  • the enamel coatings on the inventive can have such a smooth surface show that just by weathering a strong self-cleaning of the enamel coated substrates.

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Abstract

Aluminium-containing substrate for enamel coatings, comprising, at least on the areas intended for enamel coating, a surface layer of aluminium or an aluminium alloy and, on this surface layer, an oxide layer which constitutes an isotropic barrier layer with a thickness of from 0.01 to 1 mu m and a dielectric constant of between 5 and 10. Adjacent to this barrier layer there may also be a porous oxide layer with a thickness of from 0.1 to 10 mu m. An enamel coating having a thickness of, for example, from 50 to 200 mu m is applied to the substrate. The enamelled substrates can be employed as exterior panelling on vehicles or exterior facing on buildings, the enamel-coated substrates being outstandingly protected against external influences.

Description

Die Erfindung betrifft ein aluminiumhaltiges Substrat für Emailbeschichtungen, enthaltend wenigstens auf den für eine Emailbeschichtung vorgesehenen Flächen eine Oberflächenschicht aus Aluminium oder einer Aluminiumlegierung und auf dieser Oberflächenschicht eine Oxidschicht. Die Erfindung betrifft weiter ein Verfahren zur Herstellung der Oxidschicht sowie die Verwendung des aluminiumhaltigen Substrates.The invention relates to an aluminum-containing substrate for enamel coatings containing at least on the surfaces provided for an enamel coating, a surface layer made of aluminum or an aluminum alloy and on this surface layer Oxide layer. The invention further relates to a method for producing the oxide layer and the use of the aluminum-containing substrate.

Aluminiumwerkstoffe, wie beispielsweise Folien, Bänder oder Bleche werden beispielsweise für den Fassaden- und Fahrzeugbau als Deckbleche eingesetzt. Solche Deckbleche werden in der Regel anodisiert, um gegenüber Umwelteinflüssen resistent zu sein. In der Zeitschrift "Aluminium" 54. Jahrgang, 1978, Heft 8, Seiten 527 und 528, W. Grosskopf, "Überblick über Anwendung und Durchführung des Emaillierens von Aluminium", wird das Emaillieren von Reinaluminiumbändern bis 0,3 mm Dicke beschrieben. Es wurde gefunden, dass nicht jeder Aluminiumwerkstoff emaillierbar ist, und insbesondere magnesiumhaltige Aluminiumlegierungen für eine Emaillierung ungeeignet sind.Aluminum materials, such as foils, strips or sheets, for example used as facade panels for facade and vehicle construction. Such cover plates are in usually anodized to be resistant to environmental influences. In the magazine "Aluminum" 54th year, 1978, volume 8, pages 527 and 528, W. Grosskopf, "overview about the application and implementation of the enamelling of aluminum ", is the enamelling of pure aluminum strips up to 0.3 mm thick. It was not found any aluminum material can be enamelled, and in particular magnesium-containing aluminum alloys are unsuitable for enamelling.

In der UDSSR-Patentschrift 1 120 034 A wird ein Verfahren zum Emaillieren von Aluminiumlegierugen beschrieben, wobei die Legierung anodisiert wird und der anodisierte Artikel mit einem Muster eines Emailpulvers beschichtet, getrocknet und das Email gebacken wird, um eine dekorative Oberfläche resp. ein dekoratives Muster zu erhalten. In "The Surface Treatment and Finishing of Aluminium and its Alloys", Finishing Publication Ltd., Teddington, Middlesex, England, 5th edition, volume 2, 1987, Seite 1162, wird beschrieben, dass einerseits die schlechtesten Resultate durch die Anwendung einer Emailschicht auf einem anodisierten Aluminium erreicht würden, andererseits anodisiertes Aluminium wiederum eine wesentlich bessere Bindung und Widerstand gegen thermischen Schock zeige. Bis anhin war demnach das Problem einer über lange Zeit auf einer aluminiumhaltigen Substrat anhaftenden Emailschicht nicht gelöst. Es ist immer zu befürchten, dass sich eine solche Schicht bald nach dem Auftrag ablöst oder abplatzt.UDSSR patent specification 1 120 034 A describes a process for enamelling aluminum alloys described, wherein the alloy is anodized and the anodized article coated with a sample of an enamel powder, dried and baked the enamel, around a decorative surface resp. to get a decorative pattern. In "The Surface Treatment and Finishing of Aluminum and its Alloys ", Finishing Publication Ltd., Teddington, Middlesex, England, 5th edition, volume 2, 1987, page 1162, describes that on the one hand the worst results from the application of an enamel layer on one anodized aluminum would be achieved, on the other hand, anodized aluminum again a show much better bonding and resistance to thermal shock. So far therefore the problem of adhering to an aluminum-containing substrate for a long time Enamel layer not loosened. It is always to be feared that such a layer will appear soon after replaces or flakes off the order.

Die am 24.08.1994 unter der Nummer 0 611 834 A1 veröffentlichte europäische Patentanmeldung desselben Erfinders mit Prioritätsdatum vom 18.02.1993 bildet ein Dokument gemäss Artikel 54(3) EPÜ und beschreibt ein aluminiumhaltiges Substrat für Emailbeschichtungen, welches auf der mit Email zu beschichtenden Seite eine porenhaltige Oxidschicht aufweist. The European patent application published on August 24, 1994 under the number 0 611 834 A1 The same inventor with a priority date of February 18, 1993 forms a document in accordance with Article 54 (3) EPC and describes an aluminum-containing substrate for enamel coatings, which has a pore-containing oxide layer on the side to be coated with enamel having.

Aufgabe vorliegender Erfindung ist es, ein Substrat zur Verfügung zu stellen, das sich für die Beaufschlagung mit einer Emailschicht eignet, sowie ein Verfahren zur Herstellung des Substrates und eine Verwendung für das Substrat vorzuschlagen.The object of the present invention is to provide a substrate for To make available, which is suitable for the application of an enamel layer, as well to propose a method for producing the substrate and a use for the substrate.

Erfindungsgemäss wird die Aufgabe durch das Produkt gemäß Anspruch 1 gelöst. Das Verfahren zur Herstellung des Produkts nach Anspruch 1 wird in Anspruch 9 beansprucht. Die Verwendungen des Produkts nach Anspruch 1 werden in den Ansprüchen 12 bis 14 beansprucht. Vorteilhafte Ausführungsformen des Produkts bzw. des Verfahrens sind in den Ansprüchen 2 bis 8 bzw. 10 und 11 beansprucht.According to the invention the object is achieved by the product according to claim 1. The method of manufacturing the product according to claim 1 is claimed in claim 9. The uses of the product according to claim 1 are claimed in claims 12 to 14. Advantageous embodiments of the product and the method are claimed in claims 2 to 8 or 10 and 11.

Aluminiumhaltige Substrate sind beispielsweise flächenförmige Substrate aus Aluminium oder seinen Legierungen. Beispiele sind Folien, Bänder, Bleche oder Profile. Die Substrate können aber auch Körper beliebiger Gestalt mit einer Aluminiumoberfläche oder einer aluminiumhaltigen Oberfläche sein. Weitere Substrate sind Verbundwerkstoffe, die an wenigstens einer Deckschicht aus Aluminium oder aus einer Aluminiumlegierung bestehen. Vorzugsweise werden Folien, Bänder oder Bleche aus Aluminium oder Aluminiumlegierungen angewendet. Die isotrope Sperrschicht kann sich über die ganze Fläche des Aluminiums oder der Aluminiumlegierung erstrecken oder kann zumindest an den Stellen vorgesehen sein, an denen die Emailbeschichtung aufgebracht werden soll.Aluminum-containing substrates are, for example, sheet-like substrates made of aluminum or its alloys. Examples are foils, strips, sheets or profiles. The substrates but can also bodies of any shape with an aluminum surface or an aluminum-containing Surface. Other substrates are composite materials that at least a cover layer made of aluminum or an aluminum alloy. Preferably are foils, strips or sheets made of aluminum or aluminum alloys applied. The isotropic barrier layer can cover the entire surface of the aluminum or of the aluminum alloy extend or can be provided at least at the points to which the enamel coating should be applied.

Die isotrope Sperrschicht stellt eine porenfreie Oxidschicht dar und weist eine hohe Temperaturbeständigkeit sowie eine gegenüber Aluminium oder Aluminiumlegierungen erhöhte chemische Beständigkeit auf. Emailschichten zeigen auf Oxiden allgemein eine gute Haftung. Durch zeit- und temperaturabhänigige Diffusionsvorgänge können jedoch einerseits Bestandteile der Emailschicht und andererseits auch Bestandteile des aluminiumhaltigen Substrates, wie beispielsweise metallische Legierungsbestandteile oder Verunreinigungen, in die Oxidschicht gelangen und eine Schicht bilden, die keine gute Haftung der Emailschicht auf dem aluminumhaltigen Substrat gewährleistet. Solche Bestandteile (Haftinhibitoren), die eine Haftverminderung und somit beispielsweise auch Abplatzprobleme der Emailschicht bewirken können, sind beispielsweise Kupfer oder Magnesium. Die Diffusion solcher Haftinhibitoren in die Oxidschicht erfolgt, der hohen Einbrenntemperatur wegen, im wesentlichen während des Brennprozesses der Emailbeschichtung.The isotropic barrier layer is a pore-free oxide layer and has a high temperature resistance as well as increased compared to aluminum or aluminum alloys chemical resistance. Enamel layers generally show good adhesion to oxides. Through time- and temperature-dependent diffusion processes, however, components can on the one hand the enamel layer and on the other hand also components of the aluminum-containing substrate, such as metallic alloy components or impurities, in the oxide layer arrive and form a layer that does not adhere well to the enamel layer Guaranteed aluminum-containing substrate. Such components (adhesion inhibitors), the one Reduce adhesion and thus, for example, also cause spalling problems in the enamel layer can be, for example, copper or magnesium. The diffusion of such adhesion inhibitors takes place in the oxide layer, due to the high baking temperature, essentially during the firing process of the enamel coating.

Bei den aluminiumhaltigen Substraten gemäss vorliegender Erfindung wird durch deren isotrope Sperrschicht eine Diffusion von Haftinhibitoren verhindert oder wenigstens derart vermindert, dass eine gute Haftung einer auf das erfindungsgemässe Substrat deponierten Emailschicht gewährleistet ist.In the case of the aluminum-containing substrates according to the present invention, Isotropic barrier layer prevents diffusion of adhesion inhibitors or at least in this way reduces that good adhesion of a deposited on the substrate according to the invention Enamel layer is guaranteed.

Die Dichte der isotropen Sperrschicht beträgt vorteilhaft zwischen 2,5 und 3,8 g/cm3 und weist bevorzugt eine Dielektrizitätskonstante zwischen 8,5 und 10 auf.The density of the isotropic barrier layer is advantageously between 2.5 and 3.8 g / cm 3 and preferably has a dielectric constant between 8.5 and 10.

Als aluminiumhaltiges Substrat können Substrate mit einer Oberflächenschicht aus Reinaluminium, enthaltend im wesentlichen Aluminium und die handelsüblichen Verunreinigungen oder aus Aluminiumlegierungen angewendet werden. As aluminum-containing substrates, substrates with a surface layer made of pure aluminum, essentially containing aluminum and the commercially available impurities or made of aluminum alloys.

Substrate aus Aluminium können beispielsweise ein Aluminium einer Reinheit von 98,5 Gew.-% und höher, bevorzugt von 99,0 Gew.-% und höher und insbesondere 99,5 Gew.-% und höher, und dem Rest handelsübliche Verunreinigungen enthalten.Aluminum substrates can, for example, be aluminum of a purity of 98.5% by weight and higher, preferably of 99.0% by weight and higher and in particular 99.5 wt .-% and higher, and the rest of commercial impurities contain.

Bevorzugt für die Substrate sind Aluminiumknetlegierungen. Zu diesen Legierungen gehören z.B. die Typen AlMg, AlMgSi, AlCuMg und AlZnMg.Wrought aluminum alloys are preferred for the substrates. To this Alloys include e.g. the types AlMg, AlMgSi, AlCuMg and AlZnMg.

Aluminiumknetlegierungen können beispielsweise enthalten: Bis zu 1,5 Gew.-% Silicium, bis zu 1,0 Gew.-% Eisen, bis zu 4,0 Gew.-% Kupfer, bis zu 1,5 Gew.-% Mangan, bis zu 6,0 Gew.-% Magnesium, bis zu 7,0 Gew.-% Zink, bis zu 0,2 Gew.-% Titan und bis zu 1,6 Gew.-% andere Elemente, Rest Aluminium. Besonders bevorzugt sind Substrate aus einer Aluminiumlegierung, enthaltend 0,25 bis 1,5 Gew.-% Silicium, bis zu 0,3 Gew.-% Eisen, bis zu 0,25 Gew.-% Kupfer, 0,1 bis 0,8 Gew.-% Mangan, 2,7 - 5,0 Gew.-% Magnesium, bis zu 1 Gew.-% Zink, 0,01 bis 0,2 Gew.-% Titan,bis 0,2 Gew.-% Chrom, und bis zu 1,5 Gew.-% andere Elemente, Rest Aluminium.For example, wrought aluminum alloys can contain: Up to 1.5 % By weight silicon, up to 1.0% by weight iron, up to 4.0% by weight copper, up to 1.5% by weight of manganese, up to 6.0% by weight of magnesium, up to 7.0% by weight Zinc, up to 0.2% by weight of titanium and up to 1.6% by weight of other elements, Rest aluminum. Substrates made of an aluminum alloy are particularly preferred, containing 0.25 to 1.5 wt .-% silicon, up to 0.3 wt .-% Iron, up to 0.25% by weight copper, 0.1 to 0.8% by weight manganese, 2.7 - 5.0 % By weight magnesium, up to 1% by weight zinc, 0.01 to 0.2% by weight titanium, to 0.2% by weight chromium, and up to 1.5% by weight other elements, balance aluminum.

Beispiele aus der Praxis von Substraten sind Aluminiumlegierungen AlMg3, AlMg3Si, AlMg5, AlMg5Si und AlMg10.Examples from the practice of substrates are aluminum alloys AlMg3, AlMg3Si, AlMg5, AlMg5Si and AlMg10.

Bevorzugt für die Substrate sind auch Aluminiumgusslegierungen. Zu diesen Legierungen gehören z.B. die Typen: AlSi, AlSiMg, AlSiCuMg, AlMgSi-CuMg, AlMgSi und AlZnMg. Von diesen Typen wiederum sind besonders bevorzugt Aluminiumgusslegierungen enthaltend: Bis zu 11,0 Gew.-% Silicium, bis zu 1,0 Gew.-% Eisen, bis zu 5,2 Gew.-% Kupfer, bis zu 0,5 Gew.-% Mangan, bis zu 7,5 Gew.-% Magnesium, bis zu 10 Gew.-% Zink, bis zu 0,3 Gew.-% Titan, bis zu 1,2 Gew.-% Nickel, bis zu 0,03 Gew.-% Blei, bis zu 0,03 Gew.-% Zinn und bis zu 0,05 Gew.-% andere Elemente, Rest Aluminium.Aluminum casting alloys are also preferred for the substrates. To this Alloys include e.g. the types: AlSi, AlSiMg, AlSiCuMg, AlMgSi-CuMg, AlMgSi and AlZnMg. Of these types, in turn, are particularly preferred Cast aluminum alloys containing: up to 11.0% by weight silicon, up to 1.0% by weight iron, up to 5.2% by weight copper, up to 0.5% by weight Manganese, up to 7.5% by weight of magnesium, up to 10% by weight of zinc, up to 0.3 % By weight titanium, up to 1.2% by weight nickel, up to 0.03% by weight lead, up to 0.03% by weight of tin and up to 0.05% by weight of other elements, the rest being aluminum.

Die Substrate können nur diese Aluminium- oder aluminiumhaltige Oberflächenschicht und auf dieser Oberflächenschicht, zumindest partiell, die erfindungsgemässe Oxidschicht aufweisen, oder es können z.B. im Sinne eines Verbundes oder eines Laminates weitere aluminiumhaltige Schichten oder Schichten anderer Werkstoffe rückseitig der Oberflächenschicht angeordnet werden, während die erfindungsgemässe Oxidschicht vorderseitig angeordnet ist. Die Aluminium- oder aluminiumhaltige Oberflächenschicht muss sich sinngemäss an der Oberfläche befinden, damit die erfindungsgemässe Oxidschicht in zutreffender Weise daran resp. darauf angebracht werden kann. Die erfindungsgemässe Oxidschicht bildet dann die nunmehr aussen frei liegende Schicht zur weiteren Beschichtung mit der Emailschicht.The substrates can only use this aluminum or aluminum-containing surface layer and on this surface layer, at least partially, the have oxide layer according to the invention, or e.g. for the purpose of a composite or a laminate further aluminum-containing layers or layers of other materials on the back of the surface layer be arranged while the oxide layer according to the invention on the front is arranged. The aluminum or aluminum-containing surface layer must be on the surface, so that the inventive Oxide layer in an appropriate manner on it. can be attached to it. The inventive The oxide layer then forms the layer that is now exposed on the outside for further use Coating with the enamel layer.

Vorliegende Erfindung betrifft auch ein Verfahren zur Herstellung des aluminiumhaltigen Substrates für Emailbeschichtungen. Erfindungsgemäss wird das Verfahren derart ausgeführt, dass die Oxidschicht wenigstens an den für die Emailbeschichtung vorgesehenen Bereichen mittels anodischer Oxidation (Anodisieren) in einem Elektrolyten mit einem pH-Wert im Bereich zwischen 5 und 7 im Temperaturbereich von 30 bis 80°C gebildet wird, wobei bei der anodischen Oxidation die Oberflächenschicht aus Aluminium oder einer Aluminiumlegierung oder wenigstens der für die Emailbeschichtung vorgesehene Bereich in einen Elekrolyten gegeben wird, und zwischen der Oberflächenschicht und einer zweiten, im selben Elektrolyten befindlichen Elektrode eine Spannung angelegt wird.The present invention also relates to a process for producing the aluminum-containing one Substrates for enamel coatings. According to the invention, the method is carried out in such a way that that the oxide layer at least in the areas provided for the enamel coating by means of anodic oxidation (anodizing) in an electrolyte with a pH value in Range between 5 and 7 in the temperature range of 30 to 80 ° C is formed, with the anodic oxidation the surface layer of aluminum or an aluminum alloy or at least the area intended for the enamel coating in an electrolyte is given, and between the surface layer and a second, in the same electrolyte a voltage is applied to the electrode.

Zur Durchführung der anodischen Oxidation kann das aluminiumhaltige Substrat oder zumindest die für die Emailbeschichtung vorgesehenen Bereiche in einen Elektrolyten gegeben und als positive Elektrode (Anode) geschaltet werden. Als negative Elektrode (Kathode) dient dann eine weitere in denselben Elektrolyten gegebene Elektrode aus beispielsweise rostfreiem Stahl oder Blei. Wird an die Elektroden eine elektrische Spannung angelegt, so entwickelt sich an der Kathode Wasserstoffgas, an der Anode bzw. dem in den Elektrolyten getauchten aluminiumhaltigen Substrat Sauerstoffgas. Dieser Sauerstoff reagiert mit dem Aluminium zu Aluminiumoxid, welches auf der Oberflächenschicht eine Oxidschicht bildet.To carry out the anodic oxidation, the aluminum-containing substrate or at least the areas provided for the enamel coating are placed in an electrolyte and be switched as a positive electrode (anode). As a negative electrode (cathode) then another electrode in the same electrolyte is used, for example stainless steel or lead. If an electrical voltage is applied to the electrodes, then hydrogen gas develops at the cathode, at the anode or in the electrolyte submerged aluminum-containing substrate oxygen gas. This oxygen reacts with the Aluminum to aluminum oxide, which forms an oxide layer on the surface layer.

Der in der Praxis angewandte Vorgang der Erzeugung der Oxidschicht läuft im wesentlichen so ab, dass das Substrat und dabei insbesondere die mit Email zu beschichtende Obefläche aus Aluminium oder einer Aluminiumlegierung einer Vorbehandlung unterzogen wird, wobei die Obefläche zuerst entfettet, dann gespühlt und schliesslich gebeizt wird, wobei das Beizen beispielsweise mit einer Natriumhydroxidlösung in einer Konzentration von 50 bis 200 g/l bei 40 bis 60° während einer bis zehn Minunten durchgeführt werden kann. Anschliessend kann die Oberfläche gespült und mit einer Säure wie z.B. Salpetersäure, insbesondere einer Konzentration von 25 bis 35 Gew.-% im Bereich der Raumtemperatur von typischerweise 20 - 25 °C während 20 - 60 s neutralisiert, erneut gespült und gegebenenfalls getrocknet werden.The process of producing the oxide layer used in practice runs essentially so that the substrate and in particular the surface to be coated with enamel of aluminum or an aluminum alloy is subjected to a pretreatment, wherein the surface is first degreased, then rinsed and finally stained, with the pickling for example with a sodium hydroxide solution in a concentration of 50 to 200 g / l 40 to 60 ° can be carried out for one to ten minutes. Then can rinsed the surface and with an acid such as Nitric acid, especially a concentration of 25 to 35% by weight in the room temperature range of typically 20 - Neutralized at 25 ° C for 20-60 s, rinsed again and if necessary be dried.

Die Eigenschaften der gebildeten Oxidschicht hängen weitgehend von den Elektrolysebedingungen wie beispielsweise Elektrolytzusammensetzung, pH-Wert, Elektrolyttemperatur, angelegter Spannung und dem Elektrolysestrom ab. Bei Verwendung eines sauren Elektrolyten bildet sich eine Oxidschicht, die im wesentlichen eine porenfreie Grund- oder Sperrschicht und eine poröse Aussenschicht enthält. Während der anodischen Oxidation in sauren Elektrolyten bildet sich an der Substratoberfläche eine porenfreie Grund- oder Sperrschicht und gleichzeitig wird die während der anodischen Oxidation gebildete Oxidschicht an der Aussenseite durch feldinduzierte Rücklösung zum Teil chemisch wieder aufgelöst. Dadurch entsteht an der Oberfläche eine Oxidschicht mit feinen Poren, die beispielsweise senkrecht zur Oberläche stehen und gegen die Oberfläche hin offen sind. Die Dicke der Oxidschicht erreicht ihre Obergrenze, wenn sich Wachstum und Lösung die Waage halten, was von der Elektrolytzusammensetzung, der Stromdichte und der Temperatur abhängt.The properties of the oxide layer formed largely depend on the Electrolysis conditions such as electrolyte composition, pH value, electrolyte temperature, applied voltage and the electrolysis current from. When using an acidic electrolyte, one forms Oxide layer, which is essentially a non-porous base or barrier layer and contains a porous outer layer. During the anodic Oxidation in acidic electrolytes forms on the substrate surface a pore-free base or barrier layer and at the same time the during the anodic oxide layer formed on the outside partially dissolved chemically by field-induced redissolving. Thereby an oxide layer with fine pores forms on the surface for example, perpendicular to the surface and against the surface are open. The thickness of the oxide layer reaches its upper limit if growth and solution are balanced, what of the electrolyte composition, depends on the current density and the temperature.

Im pH-neutralen oder annähernd pH-neutralen Elektrolyten wird das Oxid während dem Elektrolysevorgang nicht bzw. nur sehr wenig zurückgelöst und es entstehen keine Poren. Im vorliegenden Text werden als pH-neutrale oder annähernd pH-neutrale Elektrolyten Lösungen bezeichnet, die einen pH-Wert im Bereich zwischen 5 und 7 aufweisen. Typische Beispiele solcher Elektrolyte sind Borsäure (H3BO3) oder wässrige Lösungen von Ammoniumsalzen mit Boraten, Phosphaten, Tartraten, Citraten, Vanadaten oder Molybdaten und Gemische davon. In der Praxis haben sich beispielsweise Elektrolyten, wie wässrige Lösungen, mit 1 Gew.-% NH4H2PO4 (9 % Phosphat), 10 Gew.-% H3BO3 (7 % Borat), 5 Gew.-% NH4-Molybdat (2,5 % Mo-Oxid) oder 2 Gew.-% NH4-Vanadat (2 % Vanadiumoxid), bewährt, wobei die Angaben in Klammern die für die einzelnen Elektrolyte typischen Verbindungen in Atomprozenten, welche in die Oxidschicht und insbesondere in deren äussere Oberfläche miteingebaut werden, angeben.In the pH-neutral or approximately pH-neutral electrolyte, the oxide is not or only very little redissolved during the electrolysis process and no pores are formed. In the present text, pH-neutral or approximately pH-neutral electrolytes are solutions that have a pH in the range between 5 and 7. Typical examples of such electrolytes are boric acid (H 3 BO 3 ) or aqueous solutions of ammonium salts with borates, phosphates, tartrates, citrates, vanadates or molybdate and mixtures thereof. In practice, for example, electrolytes such as aqueous solutions with 1% by weight NH 4 H 2 PO 4 (9% phosphate), 10% by weight H 3 BO 3 (7% borate), 5% by weight NH 4 molybdate (2.5% Mo oxide) or 2% by weight NH 4 vanadate (2% vanadium oxide), with the information in parentheses the compounds typical of the individual electrolytes in atomic percentages which are in the oxide layer and in particular to be built into their outer surface.

Die zu behandelnden Oberflächen werden mit dem Elektrolyten in Berührung gebracht und mittels Gleichstrom, Impulsstrom, Wechselstrom oder asymmetrischem Wechselstrom anodisch oxidiert. Unter Gleichstrom werden auch praktisch gleichartige Ströme, beispielsweise die durch Vollweggleichrichtung eines Einphasenwechselstromes oder durch Gleichrichtung eines Dreiphasenwechselstromes erzeugt werden, verstanden. Als asymmetrische Wechselstromarten können beispielsweise sinusförmiger Wechselstrom mit einer Spannungs/Zeitkurve mit ungleich hohen Amplituden im positiven und negativen Teil, rechteckförmiger Wechselstrom mit einer Spannungs/Zeitkurve mit gleich hohen Amplituden und ungleich langen Zeitanteilen des positiven und negativen Teils, rechteckförmiger Wechselstrom mit einer Spannungs/Zeitkurve mit ungleich hohen Amplituden im positiven und negativen Bereich oder rechteckförmiger Wechselstrom mit einer Spannungs/Zeitkurve mit ungleich hohen Amplituden und ungleich langen Zeitanteilen des positiven und negativen Teils angewendet werden. Ferner können sinusförmige Wechselstromkurven mit Phasenanschnitt im positiven und negativen Teil und auch andere asymmetrische Wechsel ströme mit unterbrochenem Stromfluss eingesetzt werden, wie z.B. mit dreieckförmigem Wechselstrom.The surfaces to be treated come into contact with the electrolyte brought and by means of direct current, pulse current, alternating current or asymmetrical AC anodized. Also be under DC currents of practically the same type, for example through full-wave rectification a single-phase alternating current or by rectifying one Three-phase alternating current are generated, understood. As asymmetrical AC types can include, for example, sinusoidal AC a voltage / time curve with unequal amplitudes in the positive and negative part, rectangular alternating current with a Voltage / time curve with equally high amplitudes and unequal lengths Time shares of the positive and negative part, rectangular alternating current with a voltage / time curve with unequal amplitudes in the positive and negative range or rectangular alternating current with a voltage / time curve with unequal amplitudes and unequal long time portions of the positive and negative part can be applied. Furthermore, sinusoidal alternating current curves with phase gating in positive and negative part and also other asymmetrical alternating currents be used with interrupted current flow, e.g. with triangular Alternating current.

Die anodische Oxidation in pH-neutralen oder annähernd pH-neutralen Elektrolyten wird zweckmässigerweise mit einer Spannung bis zu 600 V, vorzugsweise bis zu 500 V, und einer Stromdichte bis zu 120 A/m2, vorzugsweise bis zu 100 A/m2, durchgeführt.The anodic oxidation in pH-neutral or approximately pH-neutral electrolytes is expediently carried out with a voltage up to 600 V, preferably up to 500 V, and a current density up to 120 A / m 2 , preferably up to 100 A / m 2 .

Die anodische Oxidation in pH-neutralen oder annähernd pH-neutralen Elektrolyten kann beispielsweise durch kontinuierliche Erhöhung der angelegten Spannung bis zum Maximalwert derart durchgeführt werden, dass die Stromdichte nach einer anfänglich kontinuierlichen Erhöhung bis zum vorbestimmten Wert auf diesem Niveau konstant gehalten wird. Nach Erreichen der Maximal spannung nimmt die Stromdichte dann durch die immer dicker werdende Oxidschicht ab und erreicht nach einer gewissen Zeit eine Rest-Stromdichte. Bevorzugt wird nun das erfindungsgemässe Verfahren solange durchgeführt, bis nach erfolgter Anlegung der Maximalspannung die Stromdichte auf einen Wert zwischen 1 und 10 A/m2 gefallen ist.The anodic oxidation in pH-neutral or approximately pH-neutral electrolytes can be carried out, for example, by continuously increasing the applied voltage up to the maximum value such that the current density is kept constant at this level after an initially continuous increase up to the predetermined value. After reaching the maximum voltage, the current density then decreases due to the increasingly thick oxide layer and reaches a residual current density after a certain time. The method according to the invention is preferably carried out until the current density has fallen to a value between 1 and 10 A / m 2 after the maximum voltage has been applied.

Die dabei erhaltene Dicke der Oxidschicht ist spannungsabhängig und liegt im Bereich zwischen 10 und 16 Å/V und insbesondere zwischen 11 und 15 Å/V. Die Oxidschicht kann an ihrer freien Oberfläche eine geringe Konzentration an Ionen enthalten. Diese Ionenkonzentration wird im wesentlichen durch den Elektrolyten bestimmt und ist deshalb auf den äusseren Oberflächenbereich der Oxidschicht beschränkt. Die erfindungsgemässe Oxidschicht ist insbesondere arm an Magnesium und verhindert während und nach dem Einbrennen der Emailbeschichtung eine weitere Diffusion von Magnesium aus der Oberflächenschicht. The thickness of the oxide layer obtained is voltage-dependent and lies in the range between 10 and 16 Å / V and in particular between 11 and 15 Å / V. The oxide layer can have a small surface area Contain concentration of ions. This ion concentration becomes essentially determined by the electrolyte and is therefore on the outer Surface area of the oxide layer limited. The inventive Oxide layer is particularly low in magnesium and prevents during and after the enamel coating has burned in, another diffusion of magnesium from the surface layer.

Nach dem Anodisierverfahren kann das Substrat oder die behandelte Oberfläche weiteren Behandlungen, wie z.B. Spülen oder Imprägnieren, zugeführt werden.After the anodizing process, the substrate or the treated surface can other treatments, such as Rinsing or impregnation will.

Eine solche Nachbehandlung ohne Nachspülung stellt beispielsweise die Imprägnierung der Oxidoberfläche mit einem Flussmittel dar. Solche Flussmittel können Verbindungen oder Ionen enthalten, die im Email sehr leicht löslich sind und daher beispielsweise eine bessere Emailverankerung auf der Oxidoberfläche bewirken. Die Oxidoberflächen können solche Verbindungen oder Ionen, wie beispielsweise Vanadiumoxid, Ammoniumvanadat, Molybdänoxid, Ammoniummolybdat, Ammoniumborat, Ammoniumphosphat etc. bereits durch die anodische Oxidation enthalten. In diesem Fall wird deren Wirkung durch das Aufbringen eines entsprechenden Flussmittels unterstützt. Zudem können Flussmittel die Benetzbarkeit der Oxidoberfläche erhöhen und/oder den Schmelzpunkt der Emailfritte herabsetzen.Such an aftertreatment without rinsing is provided, for example, by Impregnation of the oxide surface with a flux. Such Fluxes can contain compounds or ions, which are very important in enamel are easily soluble and therefore, for example, better enamel anchoring effect on the oxide surface. The oxide surfaces can be such Compounds or ions, such as vanadium oxide, ammonium vanadate, Molybdenum oxide, ammonium molybdate, ammonium borate, ammonium phosphate etc. already contained by the anodic oxidation. In this case their effect is achieved by applying an appropriate flux supported. Fluxes can also affect the wettability of the oxide surface increase and / or lower the melting point of the enamel frit.

Vorliegende Erfindung betrifft auch die Verwendung des erfindungsgemässen Erzeugnisses als Substrat für Emailbeschichtungen. Insbesondere kann das Substrat nach vorliegender Erfindung für Emailbeschichtungen mit einem Schmelzpunkt von 480 °C bis zum Schmelzpunkt oder nahe dem Schmelzpunkt des Substrates verwendet werden. Mit nahe dem Schmelzpunkt werden beispielsweise Temperaturen zwischen 20 oder 10 °C unter dem Schmelzpunkt beschrieben. Zweckmässig wird das Erzeugnis als Substrat für Emailbeschichtungen auf Basis von Alkali-Silico-Titanaten, gegebenenfalls mit Einbrenntemperatur-senkenden Zusätzen, z.B. den Verbindungen, wie Oxide, des Lithiums, Bariums, Antimons, Cadmiums, Wismuts oder Vanadiums angewendet. In bevorzugter Ausführungsform betrifft die vorliegende Erfindung die Verwendung des Erzeugnisses als Substrat für Emailbeschichtungen aus einer Fritte, enthaltend die Oxide des Siliciums in Mengen von 27 bis 33 Gew.-%, bevorzugt 30 Gew.-%, des Kaliums von 9 bis 12 Gew.-%, bevorzugt 9,5 bis 11,5 Gew.-%, des Titans von 18 bis 22 Gew.-%, bevorzugt 20 bis 22 Gew.-%, des Natriums von 18 bis 22 Gew.-%, bevorzugt 20 bis 22 Gew.-%, des Aluminiums von 0,5 bis 3,2 Gew.-%, bevorzugt 2,8 bis 3,2 Gew.-%, des Lithiums von 3,5 bis 4,2 Gew.-%, bevorzugt 3,8 bis 4,2 Gew.-%, des Bors von 5 bis 8 Gew.-%, bevorzugt 6,5 bis 8 Gew.-%, des Zirkons von 0,05 bis 3 Gew.-%, vorzugweise von 2,3 bis 3 Gew.-%, des Zinks von 0,8 bis 2,0 Gew.-%, vorzugsweise 0,8 bis 1,5 Gew.-% des Magnesiums von 1 bis 1,5 Gew.-%, des Cadmiums von 0 bis 5 Gew.-%, des Antimons von 0 bis 2,8 Gew.-%, des Strontiums von 0 bis 1,5 Gew.-% und des Phosphors von 0 bis 2,5 Gew.-%.The present invention also relates to the use of the inventive Product as a substrate for enamel coatings. In particular, can the substrate according to the present invention for enamel coatings a melting point of 480 ° C to or near the melting point Melting point of the substrate can be used. With close to the melting point For example, temperatures between 20 or 10 ° C below the Melting point described. The product is useful as a substrate for enamel coatings based on alkali-silico-titanates, if necessary with baking temperature-reducing additives, e.g. the connections, such as oxides, lithium, barium, antimony, cadmium, bismuth or Vanadium applied. In a preferred embodiment, the present relates Invention the use of the product as a substrate for Enamel coatings from a frit containing the oxides of silicon in amounts of 27 to 33% by weight, preferably 30% by weight, of the potassium of 9 to 12% by weight, preferably 9.5 to 11.5% by weight, of the titanium from 18 to 22 % By weight, preferably 20 to 22% by weight, of sodium from 18 to 22% by weight, preferably 20 to 22% by weight of the aluminum of 0.5 to 3.2% by weight, preferably 2.8 to 3.2% by weight of the lithium from 3.5 to 4.2% by weight is preferred 3.8 to 4.2% by weight of boron from 5 to 8% by weight, preferably 6.5 to 8% by weight of the zircon from 0.05 to 3% by weight, preferably from 2.3 to 3 % By weight of the zinc from 0.8 to 2.0% by weight, preferably 0.8 to 1.5 % By weight of the magnesium from 1 to 1.5% by weight, the cadmium from 0 to 5 % By weight, of the antimony from 0 to 2.8% by weight, of the strontium from 0 to 1.5 % By weight and the phosphorus from 0 to 2.5% by weight.

Bevorzugt sind Emailbeschichtungen, die als Fritte mit Zusätzen auf das Substrat aufgebracht und durch Wärmebehandlung oder Einbrennen in eine Emailbeschichtung einer Dicke von 50 bis 200 µm, bevorzugt von 50 bis 120 µm und insbesondere 70 bis 100 µm, übergeführt werden. Die Emailbeschichtung ihrerseits kann beispielsweise aus einer Mischung von Oxiden in den angegebenen Mengenverhältnissen erzeugt werden. Die Oxide liegen in der Regel als Fritte, d.h. als Gemisch, das gemahlen wurde, vor. Diese Fritte kann ihrerseits mit Verarbeitungshilfsmittel, wie beispielsweise Borsäure, Natrium-Metasilikat, Kaliumhydroxid, Titandioxid und Pigmenten versetzt werden. Typisches Beispiel einer Frittezusammensetzung enthält: 100 Teile Fritte, etwa 4 Teile Borsäure, einen Teil mit Natrium-Metasilikat, einen Teil Kaliumhydroxid, fünf bis fünfzehn Teile Titandioxid und einen bis sieben Teile Pigment. Entsprechend den Anforderungen an die farbliche Gestaltung der Emaillierung können farbgebende Pigmente angewendet werden. Die Emaillierung kann beispielsweise eine Schicht umfassen, wobei eine Schicht einer Frittenzusammensetzung auf die Substratoberfläche aufgebracht wird und in einem Brennvorgang eingebrannt, d.h. in die Emailbeschichtung überführt wird. Im Rahmen der Erfindung liegen auch weitere Verfahren, gemäss denen zwei Schichten in zwei Brennvorgängen, drei Schichten in drei Brennvorgängen resp. mehrere Schichten in mehreren Brennvorgängen aufgebracht werden. Andere Verfahren zur Aufbringung von Emailschichten bestehen im Aufbringen von zwei oder weiteren Fritteschichten oder Frittezusammensetzungen mit nur einem Brennvorgang. Die Fritte kann beispielsweise eine mittlere Korngrösse von weniger als 74 µm und zweckmässig weniger als 44 µm aufweisen. Die Fritte kann durch Aufstreuen, Sprayen, Eintauchen oder Schlämmen aufgebracht werden. Weitere Möglichkeiten sind das elektrostatische Sprühen oder die Elektrophorese. Fallweise muss die Fritte, sofern sie mit einem Suspensionshilfsmittel wie Wasser aufgebracht wurde, getrocknet werden. Nach dem Trocknen kann das beschichtete Substrat in einen Ofen gebracht werden, wobei das Brennverfahren kontinuierlich oder stufenweise erfolgen kann. Typische Brennzeiten liegen im Bereich zwischen 3 und 10 Minuten, wobei Brennzeiten zwischen 3 und 6 Minuten bevorzugt werden. Typische Brenntemperaturen liegen zwischen 480 und 560 °C. Alle Verfahren können schrittweise oder kontinuierlich durchgeführt werden.Enamel coatings, which are used as frit with additives on the Applied and by heat treatment or baking in a substrate Enamel coating with a thickness of 50 to 200 microns, preferably from 50 to 120 microns and in particular 70 to 100 microns, are transferred. The enamel coating in turn, for example, from a mixture of oxides are generated in the specified proportions. The oxides usually lie as a frit, i.e. as a mixture that was ground in front. This frit can in turn be used with processing aids such as for example boric acid, sodium metasilicate, potassium hydroxide, titanium dioxide and pigments are added. Typical example of a frit composition contains: 100 parts frit, about 4 parts boric acid, one Part with sodium metasilicate, part with potassium hydroxide, five to fifteen Parts of titanium dioxide and one to seven parts of pigment. Corresponding the requirements for the color design of the enamelling coloring pigments are used. The enamelling can, for example comprise a layer, a layer of a frit composition is applied to the substrate surface and in one firing process branded, i.e. is transferred into the enamel coating. in the Further methods are also within the scope of the invention, according to which two Layers in two burns, three layers in three burns resp. multiple layers can be applied in multiple firing processes. Other methods of applying enamel layers are by applying of two or more frit layers or frit compositions with just one burn. The frit can be, for example, a medium one Grain size of less than 74 microns and suitably less than 44 microns. The frit can be sprinkled, sprayed, dipped or Slurries are applied. Electrostatic is another option Spraying or electrophoresis. Occasionally, the frit, if it was applied with a suspension aid such as water, be dried. After drying, the coated substrate can be in a furnace, the combustion process being continuous or can be done gradually. Typical burning times are between 3 and 10 minutes, with burn times between 3 and 6 minutes preferred will. Typical firing temperatures are between 480 and 560 ° C. All procedures can be carried out step by step or continuously will.

Die erfindungsgemässe Oberflächenschicht und die darüber angeordnete Oxidschicht stellen ein Substrat dar, welches für eine Emailbeschichtung besonders geeignet ist, da die Benetzung durch die Bestandteile der Emailbeschichtung während des Einbrennprozesses in besonderem Masse ausgeprägt ist und dadurch die Verwendung von Fritten mit niedrigerem Schmelzpunkt, d.h. mit einem Schmelzpunkt von beispielsweise bis zu 20 °C unter dem üblichen Bereich, ermöglicht wird.The surface layer according to the invention and the one arranged above it Oxide layers represent a substrate which is used for an enamel coating is particularly suitable since the wetting by the components of the Enamel coating in particular during the baking process is pronounced and thus the use of frits with lower Melting point, i.e. with a melting point of up to 20, for example ° C below the usual range.

Die Substrate nach vorliegender Erfindung mit den Emailbeschichtungen weisen eine äusserst glatte Oberfläche auf. Durch die Emailbeschichtung ist das Substrat gegen mechanische, physikalische, chemische und actinische Einflüsse und beispielsweise gegen Umwelteinflüsse weitgehend geschützt. Die Oberfläche ist glatt, glänzend und von grosser Härte. Durch die glatte Oberfläche können beispielsweise Schmutz, Farbstoffe, lösungsmittelhaltige Farbstoffe oder in einem Trägermedium befindliche Farbstoffe nicht in Poren eindringen und das Aussehen der Oberfläche verändern oder verunstalten. Die grosse Härte der Oberfläche schützt vor Abrasion und anderen mechanischen Einwirkungen.The substrates according to the present invention with the enamel coatings have an extremely smooth surface. Thanks to the enamel coating is the substrate against mechanical, physical, chemical and actinic Influences and, for example, largely protected against environmental influences. The surface is smooth, shiny and extremely hard. By The smooth surface can, for example, dirt, dyes, solvent-based Dyes or in a carrier medium Dyes do not penetrate pores and the appearance of the surface change or deface. The great hardness of the surface protects against Abrasion and other mechanical influences.

Vorliegende Substrate mit einer Emailbeschichtung eignen sich beispielsweise im Hochbau als Fassadenplatten für Innen- und Aussenanwendungen, als Aussenschicht an Verbundplatten für Fassaden oder für den Innenausbau, als Verkleidungsplatten oder Karrosserieteile für Fahrzeuge, wie Eisenbahnwagen, Busse und andere Strassen- und Schienenfahrzeuge und für Anwendungen in Bereichen korrosiver Atmosphäre. Auch geeignet sind die mit Email beschichteten Substrate nach vorliegender Erfindung für Möblierungen in öffentlichen Bereichen wie Plakatsäulen, Briefkästen, Automatenkästen und dergleichen, die z.B. durch Vandalismus einer erhöhten Gefährdung ausgesetzt sind. Die Emailbeschichtungen auf den erfindungsgemässen Substraten können beispielsweise eine derart glatte Oberfläche aufweisen, dass allein durch die Bewitterung eine starke Selbstreinigung der emailbeschichteten Substrate erfolgt.Existing substrates with an enamel coating are suitable, for example in building construction as facade panels for indoor and outdoor applications, as an outer layer on composite panels for facades or for interior work, as cladding panels or body parts for vehicles, such as Railway wagons, buses and other road and rail vehicles and for Corrosive atmosphere applications. They are also suitable substrates coated with enamel according to the present invention for furniture in public areas such as poster pillars, letter boxes, Vending machine boxes and the like, e.g. due to vandalism an increased Are at risk. The enamel coatings on the inventive For example, substrates can have such a smooth surface show that just by weathering a strong self-cleaning of the enamel coated substrates.

Claims (14)

  1. Aluminium-containing substrate for enamel coatings containing a surface layer of aluminium or an aluminium alloy at least on the surfaces provided for an enamel coating and a pore-free oxide layer, which is an isotropic barrier layer of a thickness of 0.01 to 0.5 µm having a dielectric constant between 5 and 10, directly on this surface layer.
  2. Aluminium-containing substrate according to claim 1, wherein the thickness of the isotropic barrier layer is between 2.5 and 3.8 g/cm3.
  3. Aluminium-containing substrate according to claim 1, wherein the isotropic barrier layer has a dielectric constant between 8.5 and 10.
  4. Aluminium-containing substrate according to claim 1, wherein the surface layer is an aluminium wrought alloy.
  5. Aluminium-containing substrate according to claim 4, wherein the aluminium wrought alloy contains up to 1.5 wt.% silicon, up to 1.0 wt.% iron, up to 4.0 wt.% copper, up to 1.5 wt.% manganese, up to 6.0 wt.% magnesium, up to 7.0 wt.% zinc, up to 0.2 wt.% titanium and up to 1.6 wt.% of other elements, remainder aluminium.
  6. Aluminium-containing substrate according to claim 4, wherein the surface layer is an aluminium wrought alloy containing 0.25 to 1.5 wt.% silicon, up to 0.3 wt.% iron, up to 0.25 wt.% copper, 0.1 to 0.8 wt.% manganese, 2.7 to 5.0 wt.% magnesium, up to 1.0 wt.% zinc, 0.01 to 0.2 wt.% titanium, up to 0.2 wt.% chromium and up to 1.5 wt.% of other elements, remainder aluminium.
  7. Aluminium-containing substrate according to claim 1, wherein the surface layer is an aluminium cast alloy.
  8. Aluminium-containing substrate according to claim 7, wherein the aluminium alloys contain up to 11.0 wt.% silicon, up to 1.0 wt.% iron, up to 5.2 wt.% copper, up to 0.5 wt.% manganese, up to 7.5 wt.% magnesium, up to 10 wt.% zinc, up to 0.3 wt.% titanium, up to 1.2 wt.% nickel, up to 0.03 wt.% lead, up to 0.03 wt.% tin and up to 0.05 wt.% of other elements, remainder aluminium.
  9. Process for producing an aluminium-containing substrate for enamel coatings according to claim 1, in which the oxide layer according to claim 1 is formed at least on the regions provided for the enamel coating by means of anodic oxidation in an electrolyte having a pH value in the range between 5 and 7 in the temperature range from 30 to 80°C, wherein for anodic oxidation, the surface layer of aluminium or an aluminium alloy, or at least the region provided for the enamel coating, is placed in an electrolyte, and a voltage is applied between the surface layer and a second electrode situated in the same electrolyte.
  10. Process according to claim 9, in which anodic oxidation is carried out at an applied voltage up to 600 V and a current density up to 120 A/m2.
  11. Process according to claim 10, in which anodic oxidation is carried out until, after the maximum voltage has been applied, the current density has dropped to a value between 1 and 10 A/m2.
  12. Use of the product according to claim 1 as a substrate for enamel coatings having a melting point from 480°C to the melting point of the substrate.
  13. Use of the product according to claim 1 as a substrate for enamel coatings containing the oxides of silicon in quantities from 27 to 33 wt.%, preferably 30 wt.%, of potassium from 9 to 12 wt.%, preferably 9.5 to 11.5 wt.%, of titanium from 18 to 22 wt.%, preferably 20 to 22 wt.%, of sodium from 18 to 22 wt.%, preferably 20 to 22 wt.%, of aluminium from 0.5 to 3.2 wt.%, preferably 2.8 to 3.2 wt.%, of lithium from 3.5 to 4.2 wt.%, preferably 3.8 to 4.2 wt.%, of boron from 5 to 8 wt.%, preferably 6.5 to 8 wt.%, of zirconium from 0.05 to 3 wt.%, preferably from 2.3 to 3 wt.%, of zinc from 0.8 to 2.0 wt.%, preferably 0.8 to 1.5 wt.%, and optionally one or more of the oxides of magnesium from 1 to 1.5 wt.%, of cadmium from 0 to 5 wt.%, of antimony from 0 to 2.8 wt.%, of strontium from 0 to 1.5 wt.% and of phosphorus from 0 to 2.5 wt.%.
  14. Use of the product according to claim 1 as a substrate for enamel coatings which is applied to the substrate as a frit with additives and is converted to an enamel coating of a thickness of 50 to 200 µm, preferably 50 to 120 µm, and in particular 70 to 100 µm, by heat treatment.
EP94810572A 1993-10-13 1994-09-30 Enamellable oxide layer Expired - Lifetime EP0648863B2 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
CH308193A CH686374A5 (en) 1993-10-13 1993-10-13 Emaillierbare oxide.
CH308193 1993-10-13
CH3081/93 1993-10-13

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EP0648863A1 EP0648863A1 (en) 1995-04-19
EP0648863B1 true EP0648863B1 (en) 1998-01-14
EP0648863B2 EP0648863B2 (en) 2001-05-02

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AT (1) ATE162234T1 (en)
CH (1) CH686374A5 (en)
DE (1) DE59405021D1 (en)
DK (1) DK0648863T5 (en)
ES (1) ES2112505T5 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20210073708A (en) * 2019-12-10 2021-06-21 김준수 Aluminum alloy for enamel coating and method for manufacturing die casted aluminum alloy frying pan

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2585273B1 (en) * 1985-07-24 1988-05-13 Daussan & Co COATING FOR PROTECTING THE INTERIOR OF A METALLURGICAL CONTAINER AND METHOD FOR PRODUCING THE SAME
ATE407101T1 (en) 1999-11-23 2008-09-15 Pemco Brugge Nv ENAMELING OF ALUMINUM ALLOY SURFACES
DE102009045522A1 (en) * 2009-10-09 2011-04-14 BSH Bosch und Siemens Hausgeräte GmbH Iron sole plate, particularly for steam iron, has surface, which is provided for placement on objects to be ironed, where surface is made of anodized aluminum or is coated with anodized aluminum layer
RU2535274C2 (en) * 2009-10-09 2014-12-10 Бсх Бош Унд Сименс Хаусгерете Гмбх Iron soleplate, in particular, steam iron soleplate
ES2390028B1 (en) * 2011-04-08 2013-10-21 BSH Electrodomésticos España S.A. Procedure for coating an aluminum surface of an aluminum element, aluminum element and aluminum plate sole
CN115177385B (en) * 2022-07-15 2023-08-22 成都贝施美生物科技有限公司 Implant with natural tooth root color

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0611834A1 (en) * 1993-02-18 1994-08-24 Alusuisse-Lonza Services Ag Aluminium based substrate for enamelling

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR440516A (en) * 1911-05-05 1912-07-12 Paul Auguste Felix De Saint Ma Aluminum oxide in deep layer, process for obtaining this aluminum oxide and application of this oxide and bare aluminum as an insulated electrical conductor
US2991234A (en) * 1958-08-11 1961-07-04 Croname Inc Enameled aluminum and process for manufacture thereof
JPS63270482A (en) * 1987-04-28 1988-11-08 Nisshin Steel Co Ltd Aluminum plated enameled steel sheet

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0611834A1 (en) * 1993-02-18 1994-08-24 Alusuisse-Lonza Services Ag Aluminium based substrate for enamelling

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20210073708A (en) * 2019-12-10 2021-06-21 김준수 Aluminum alloy for enamel coating and method for manufacturing die casted aluminum alloy frying pan

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CH686374A5 (en) 1996-03-15
EP0648863B2 (en) 2001-05-02
ES2112505T5 (en) 2001-07-01
DE59405021D1 (en) 1998-02-19
DK0648863T3 (en) 1998-09-14
EP0648863A1 (en) 1995-04-19
ES2112505T3 (en) 1998-04-01
DK0648863T5 (en) 2001-01-29
ATE162234T1 (en) 1998-01-15

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