DE102012008544A1 - Chromed composites without nickel coating - Google Patents

Abstract

The present invention is directed to a composite and a corresponding method of making this composite. In particular, the present invention relates to composites having a particular sequence of metals as a surface coating. These are particularly suitable for use in the sanitary sector.

Description

The present invention is directed to a composite and a corresponding method of making this composite. In particular, the present invention relates to composites having a particular sequence of metals as a surface coating. These are particularly suitable for use in the sanitary sector.

Especially in the sanitary sector today composites of plastic or metal are used, which must have a sufficiently corrosion-resistant surface coating and beyond should look decorative appeal. As a surface coating, which has been prevalent in this area for some time, the coating of composites with chrome is considered. Frequently, under the outer chromium layer, special sub-layers which improve the appearance, or the adhesion, are used, in particular of nickel ( EP 1918425 ; EP 1826296 ; DE 10 2005 041 375 ; EP2048265 ; Gaida et al., Technology of Electroplating, Eugen G. Leuze Verlag, 1st Edition, p. 214 ).

Since 2001, the sale of consumer durables coated with nickel-containing refining alloys has been in line with European standards EU Directive 94/27 / EC no longer permitted or only possible under strict conditions, since nickel and nickel-containing metal layers are contact allergens. Particularly in the sanitary sector, the problem here arises that composite materials which have corresponding nickel layers can corrode, and thus lead to, for example, the drinking water being loaded with nickel ions. Accordingly, attempts are being made to remove nickel from such composites and replace them with other metals on which the outer chromium layer can be deposited in a corresponding manner ( Energy I Water Practice, 2010, 2, p. 16ff. ; http://www.managermagazin.de/lifestyle/wohnen/0,2828,50123,00.html ; www.baumarkt.de/nxs/9148///baumarkt/schablone1/Metalle-im-Trinkwasser-ein-Problem-für-Kleinkinder-und-Babys.de ; IKZ-Haustechnik, issue 12/2001, p. 27ff. ; Norikazu Sugaya, SLNA Metal Surface Treatment For Rust Prevention and Lead Percolation Resistance of Copper Alloy Piping Materials ,).

It is known that chromium layers can also be deposited on base materials other than nickel. However, if it is thought of a bright chrome plating, nickel undercoats are preferred for corrosion protection and decorative reasons. As a rule, the nickel underlayers bring about a certain leveling of the surface structure of the substrate, so that the unevenness / roughness and thus its mattness are reduced.

• 1. Es ist im Vergleich zu Nickel sehr weich. Die darauf aufgebrachte dünne, sehr harte Chromschicht ist aufgrund der weichen Unterlage nicht kratz- und abriebbeständig genug.
• 2. Die Farbe dieser dünnen Chromschichten wird vom darunter liegenden Kupfer beeinflusst und ist somit nicht mehr kompatibel mit der Kombination „Nickel +, Chrom”.
• 3. Kupfer weist im Vergleich zu einer Nickelzwischenschicht eine wesentlich verringerte Korrosionsbeständigkeit in z. B. der Salznebelprüfung ( DIN 50021-SS ) auf.

However, it is also known to deposit a covering layer of chromium on intermediate layers of, for example, copper ( Galvanic Plating, G. Lausmann, J. Unruh, p. 225 ; EP 1826296 ; DE 10 2005 041 375 ). However, the use of copper as a thick intermediate layer has three major disadvantages:

• 1. It is very soft compared to nickel. The thin, very hard chromium layer applied to it is not scratch and abrasion resistant enough due to the soft base.
• 2. The color of these thin chromium layers is influenced by the underlying copper and is therefore no longer compatible with the combination "nickel +, chrome".
• 3. Copper has a significantly reduced corrosion resistance in z. B. the salt spray test ( DIN 50021-SS ) on.

Chrome layers are deposited on commodities and composites of trivalent or hexavalent chromium electrolytes. For example, this describes the US 4062737 a deposition of chromium from a trivalent chromium electrolyte having a complex of chromium (III) and thiocyanates. Also the US 3954574 refers to the deposition of chromium from electrolytes containing trivalent chromium. Here are used as additives carboxylic acids selected from the group of formic acid and acetic acid in a certain ratio to chromium. Also to be present are bromides and ammonium ions. Other Cr (III) based electrolytes can be found in US Pat US 4169022 , of the US 4278512 or US 5194100 , In the latter specification, chromium (VI) ions in the electrolyte are reduced to chromium (III) ions by certain additives, such as methanol or formic acid, to be electrodeposited.

However, electrolytic chrome plating of hexavalent chromium electrolyte composites has also historically been the more common case. The "classic" chrome bath is based on a patent ( DE398054 ) Erik Liebreichs from 1920, which he mb H. Berlin for the electro-chrome society further developed. Another patent ( DE448526 ) from 1924 is considered the key patent for the chrome plating. At 50 A / dm ^2, about 18% current efficiency (= efficiency, ie 82% of the current generated by hydrogen) is achieved here. Another electrolyte with hexavalent chromium is used in the US 4093522 specified. There, nitrogen-containing heterocycles in the form of their halide and / or sulfate ions are added as additives to the bath.

However, it is clear that to date it has apparently not been sufficiently possible to provide composite materials, for example for the sanitary sector, which have a glossy, decorative and correspondingly persistent upper layer of chromium and contain no nickel.

It was therefore an object of the present invention to provide such composites and a corresponding method for their production, it being important to ensure that they have nickel-free coatings and can be produced particularly advantageous from the economic and ecological point of view.

These and other objects which are obvious from the state of the art are solved by a composite material having the features of claim 1 and a method according to claim 4. Preferred embodiments are in dependent on these two claims dependent claims. Claims 8 and 9 are directed to a preferred use of the composites of the invention.

• – ein Substrat (1) bestehend aus Kunststoff oder Metall, insbesondere Messing, Aluminium, Zink oder Edelstahl,
• – eine Beschichtung aus wenigstens einer Metallschicht (2) aufweisend Kupfer mit einer Schichtdicke von 0,01–30 μm,
• – eine Beschichtung aus wenigstens einer Metallschicht (3) aufweisend eine Legierung aus Kupfer, Zinn und Zink oder Kupfer und Zinn von 0,01–15 μm,
• – eine Beschichtung als haftvermittelnde Schicht aus wenigstens einer Metallschicht aufweisend Chrom (4a), Kupfer (4b), Gold (4c), Palladium (4d) oder Eisen (4e) mit einer Schichtdicke von 0,001–0,5 μm,
• – eine Oberflächenbeschichtung im Wesentlichen aus Chrom (5) mit einer Schichtdicke von 0,01–5 μm,

wobei im Falle einer haftvermittelnden Schicht aufweisend Chrom (4a), dieses aus einem Elektrolyten elektrolytisch abgeschieden wird, welcher Chrom überwiegend in der 3-wertigen Oxidationsstufe aufweist. Die obere Chromschicht (5) wird aus einem Elektrolyten elektrolytisch abgeschieden, der Chrom überwiegend in der 6-wertigen Oxidationsstufe aufweist. Hierdurch gelangt man äußerst überraschend, dafür aber nicht minder vorteilhaft zur Lösung der gestellten Aufgabe. Durch den Einsatz der erfindungsgemäßen Schichtenfolge mit einer extrem dünnen haftvermittelnden Schicht (4) aus den angegebenen Metallen (a–e) gelingt es, die gesteckten Ziele sicher zu erreichen. Die so erhaltenen Gegenständen können u. a. auch im Sanitärbereich vorteilhaft eingesetzt werden, da sie ausreichend korrosionsresistent sind und auf der anderen Seite jedoch ihren dekorativ ansprechenden Chromcharakter über eine ausreichend lange Zeitspanne hinweg beibehalten. Dass dies mit entsprechend verchromten Verbundwerkstoffen ohne eine Nickelunterschicht möglich ist, war so dem bekannten Stand der Technik bis dato nicht zu entnehmen.By indicating a composite material in which the decorative surface consists essentially of chromium and which has the following materials from the inside to the outside:

• A substrate (1) consisting of plastic or metal, in particular brass, aluminum, zinc or stainless steel,
• A coating of at least one metal layer (2) comprising copper with a layer thickness of 0.01-30 μm,
• A coating of at least one metal layer (3) comprising an alloy of copper, tin and zinc or copper and tin of 0.01-15 μm,
• A coating as an adhesion-promoting layer of at least one metal layer comprising chromium (4a), copper (4b), gold (4c), palladium (4d) or iron (4e) with a layer thickness of 0.001-0.5 μm,
• A surface coating essentially of chromium (5) with a layer thickness of 0.01-5 μm,

wherein in the case of an adhesion-promoting layer comprising chromium (4a), this is electrolytically deposited from an electrolyte which has chromium predominantly in the 3-valent oxidation state. The upper chromium layer (5) is electrolytically deposited from an electrolyte having chromium predominantly in the 6-valent oxidation state. This results in extremely surprising, but not less advantageous to solve the task. By using the layer sequence according to the invention with an extremely thin adhesion-promoting layer (4) of the specified metals (a-e), it is possible to safely achieve the goals set. The objects thus obtained can be advantageously used, inter alia, in the sanitary sector, since they are sufficiently resistant to corrosion and on the other hand, however, retain their decoratively appealing chrome character over a sufficiently long period of time. That this is possible with corresponding chromium-plated composite materials without a nickel underlayer, was so far not apparent from the known state of the art to date.

Suitable substrates are all materials suitable for chromium plating by the person skilled in the art. These may preferably be of a metallic nature, wherein the material to be coated is preferably selected from the group consisting of zinc, copper, tin, aluminum, iron, magnesium, etc. or corresponding alloys of these metals such as brass, bronze, steel, etc., especially brass, aluminum, zinc or stainless steel. However, plastics can also be coated accordingly. Here, the plastic part, which is preferably made of ABS, according to methods known in the art often first provided with a metal base layer before the copper layer (2) or the subsequent layers are applied according to the invention.

The layer thickness of the applied, preferably substantially copper-comprising metal layer (2) may be between 0.01-30 microns, preferably 0.1-20 microns and more preferably between 0.5-15 microns. How such a layer can be deposited on the corresponding substrates is well known to the person skilled in the art. Particularly preferably, this layer (2) consists only of copper. For the deposition of the applied copper layer on plastics reference is made to the literature ( Electroplating Technology, Chap. 5 - Electroplating of plastics, Gaida, Aßmann, 1996, Leuze-Verlag ). Regarding the application of the copper layer (2) to metals as a substrate basis, reference is also made to the literature ( Kupferschichten, Kanani, p. 62ff, 2000, Leuze Verlag ). The deposition of the copper layer from an electrolyte preferably takes place under reducing conditions (reductive) or by using a current flow (electrolytic). Preferably, the electrolytic deposition of an acidic electrolyte. As has been said, the copper layer discussed here may preferably consist essentially of pure copper.

In a next step, a correspondingly thick layer (3) of an alloy of copper, tin and zinc or copper and tin is deposited on this layer (2). This alloy layer may be a thickness of 0.01-15 .mu.m, preferably 0.1-10 microns and more preferably 0.5-5 microns. How such a layer can be deposited on the corresponding substrates is well known to the person skilled in the art. The deposition of the copper alloy layer from an electrolyte is preferably carried out using a current flow (electrolytic). Preferably, the electrolytic deposition of a preferably acidic electrolyte. In addition, reference is made to the literature and citations contained therein ( DE 10 2011 008 836 ; DE 10 2008 032 398 ; DE 50 2007 002 479 ,

In a further step, an intermediate layer serving as an adhesion promoter is applied. This intermediate layer preferably consists essentially and particularly preferably exclusively of either iron (4e), palladium (4d), gold (4c), copper (4b) or chromium (4a), preferably copper, iron or chromium and more preferably chromium or Iron. The adhesion-promoting intermediate layer, in particular of the metals (4a-d), may have a thickness of 0.001-0.5 μm, preferably 0.05-0.4 μm and particularly preferably between 0.1-0.3 μm. The deposition of the thin layers 4d, 4c and 4b is known to the person skilled in the art ( Precious metal coatings, series Electroplating and Surface Treatment, Hasso Kaiser, Eugen G. Leuze Verlag, 2002 ; Kupferschichten, Kanani, p. 62ff, 2000, Leuze Verlag ).

It is now a characteristic of the present invention in the case of layer (4a) that this adhesion-promoting layer is deposited (electrolytically) from an electrolyte which has chromium predominantly in the trivalent oxidation state. The Cr III content in the electrolyte should preferably be> 60%, more preferably> 70% and more preferably> 80%, very particularly preferably> 90%, compared to the Cr VI content. Within the scope of what is technically feasible and economically feasible, the chromium portion in the electrolyte can very preferably consist exclusively of 3-valent chromium. By means of an intermediate layer produced in this way, it is possible, as with the other metal layers specified, to ensure that a sufficiently level, glossy and adherent final layer comprising chromium can be produced. The deposition of the lower chromium layer (4a) can be carried out by methods known to the person skilled in the art ( The galvanic chrome plating, G. Lausmann, J. Unruh, 2006, Leuze-Verlag ).

In the case of an adhesion-promoting intermediate layer of iron (4e), it has proven to be particularly advantageous if this iron layer precipitates extremely thin. It is therefore preferred in this regard to deposit the iron layer with a thickness of 0.001-0.5 microns, more preferably with a thickness of 0.005-0.4 microns and most preferably with a thickness of 0.01-0.2 microns. Corresponding electrolytes for this purpose are familiar to the person skilled in the art ( On the Electrolytic Deposition of Iron, August Pfaff, Zeitschrift fur Elektrochemie und angewandte Chemie, 1910, Vol. 16, 217-223 ).

It is now a characteristic of the present invention in the case of layer (4e) that this adhesion-promoting layer is deposited (electrolytically) from an electrolyte which has iron predominantly in the trivalent oxidation state. The iron III is preferably present in an excess of> 60%, preferably> 70%, more preferably> 80% and very particularly preferably> 90%, in comparison with the divalent iron. In the context of the technically feasible and economically meaningful, the iron content in the electrolyte can extremely preferably consist exclusively of 3-valent iron. In addition, this electrolyte may contain other ingredients such. As conductive salts, complexing agents, buffering agents and various brighteners have. The presence of these further constituents of the electrolyte are advantageous in order to deposit the desired iron layer in appropriate quality. By means of an intermediate layer produced in this way, it is possible, as with the other metal layers specified, to ensure that a sufficiently level, glossy and adherent final layer comprising chromium can be produced.

Finally, a further, outer surface layer (5) of substantially chromium which has at least the resistance and the decorative appearance of conventional chromium layers is applied to these intermediate layers (4a-e) electrolytically. The layer may be present in a thickness of 0.01-5 microns, preferably 0.1-2 microns and more preferably between 0.1-0.5 microns in the composite material. According to the invention, however, this layer is in contrast to the chrome intermediate layer just described (4a) is not deposited from an electrolyte containing chromium predominantly in the oxidation state (III). In the electrolyte described here, the chromium is present predominantly in the 6-valent form. The Cr-VI content in the electrolyte should preferably be> 60%, more preferably> 70% and more preferably> 80, most preferably> 90%, compared to the Cr-III content. In the context of the technically feasible and economically reasonable, the chromium content in the electrolyte can extremely preferably consist almost exclusively of hexavalent chromium. Electrolytes with which a corresponding chromium layer can be deposited on the composite material prepared as above are likewise well known to the person skilled in the art. Reference is made in this regard to the known literature ( The galvanic chrome plating, G. Lausmann, J. Unruh, 2006, Leuze-Verlag ). The layer (5) is preferably deposited from an electrolyte which has the following constituents:
Chromium (VI) oxide, preferably in a concentration of 240-260 g / l
96% sulfuric acid, preferably in a concentration of 0.5% by weight
H ₂ SiF ₆ , preferably in a concentration of 1.5-4 g / l.

Most preferably, a composite material comprising the metal layer (2) with a thickness of 1-20 microns, the metal layer (3) with a thickness of 1-5 microns, and the metal layer (4a-d) with a thickness of 0, 1-0.4 microns, or the metal layer (4e) having a thickness of 0.001-0.5 microns, wherein the surface coating of substantially chromium (5) has a layer thickness of 0.1-0.5 microns.

The present invention also relates to a correspondingly adapted method for producing the composite materials according to the invention. It should be noted that the subject features, which have also been used to characterize the composite materials of the invention, apply mutatis mutandis to the present method. The method according to the invention for producing these composite materials is therefore characterized in that the lower adhesion-promoting layer comprises chromium (4a), copper (4b), gold (4c), palladium (4d) or iron (4e).

• – Abscheiden einer Grundschicht (2) aufweisend Kupfer auf das Substrat (1);
• – den Verbundwerkstoff für den nächsten Schritt vorbereiten;
• – auf diesen elektrolytisch eine Schicht (3) bestehend aus Kupfer und Zinn oder Kupfer-Zinn-Zink abscheiden;
• – den Verbundwerkstoff für den nächsten Schritt vorbereiten
• – die Metallschicht aufweisend Chrom (4a), Kupfer (4b), Gold (4c), Palladium (4d) oder Eisen (4e) abscheiden;
• – den Verbundwerkstoff für den nächsten Schritt vorbereiten;
• – die Metallschicht (5) aufweisend Chrom abscheiden.

In a particularly preferred embodiment of the present invention, the composite material is produced as follows:

• - depositing a base layer (2) comprising copper on the substrate (1);
• - prepare the composite material for the next step;
• - On this electrolytically deposit a layer (3) consisting of copper and tin or copper-tin-zinc;
• - Prepare the composite material for the next step
• - deposit the metal layer comprising chromium (4a), copper (4b), gold (4c), palladium (4d) or iron (4e);
• - prepare the composite material for the next step;
• - Have the metal layer (5) comprising chromium.

In this case, in the case of chromium (4a), electrolytic deposition takes place as an adhesion promoter from an electrolyte which has chromium predominantly in the 3-valent oxidation state. The upper chromium layer (5), however, is electrolytically deposited from an electrolyte which has chromium predominantly in the 6-valent oxidation state.

The steps described herein for depositing a metal layer on the composite are described above and in the literature to a sufficient extent. With regard to the steps which are carried out for the preparation of the composite material for the deposition of a further metal layer, it should be noted that this preparation can be carried out by methods known to the person skilled in the art ( Practical Electroplating, Author Team, 1984, Leuze-Verlag ). In a particular embodiment of the present invention, this preparation comprises one or more steps selected from the group consisting of rinsing the composite, degreasing the composite, and activating the composite. Particularly preferably, the degreasing of the composite takes place by electrolytic means. The methods for rinsing, electrolytic degreasing and activation of the composite are well known to those skilled in the art ( Cleaning and degreasing in the metal industry, Jelinek, 1999, Leuze-Verlag ). Most preferably, the preparation of the composite material for depositing a further metal layer is carried out by a method which provides first the rinsing of the material, then the electrolytic degreasing, thereafter the rinsing and finally the activation and final rinsing of the composite material. Using this sequence of preparatory steps, the composites to be coated are optimally prepared for subsequent metal deposition.

After the composite material has received its final chromium deposition, a rinsing step can advantageously be followed again before the now finished composite material is dried. The drying can also be carried out by methods known to the person skilled in the art. Preferably, the composite material is dried in a stream of air at temperatures of 50-80 ° C, preferably 55-75 ° C and more preferably at 60-70 ° C.

The composite thus produced contains no nickel. However, it surprisingly has a correspondingly decorative appearance and is no less durable than the known nickel-containing composite materials, especially when it comes to the visual appearance and corrosion resistance. It was not to be surmised against the background of the known state of the art that the sequence according to the invention of copper layer, copper alloy layer, thin adhesion-promoting intermediate layer and chromium layer is able to provide a result comparable with the nickel-containing and chromium-plated composite materials. On the basis of these findings, the composite materials according to the invention find their advantageous uses, in particular in the field of sanitary facilities or in the case of all objects which may come into contact with the skin.

Exemplary electrolytes for the preparation of the individual layers:

To produce the copper layer (2) - z. B. Umicore copper 836, Fa. Umicore Galvanotechnik:

components: • copper 60 g / l (55-65 g / l), adding z. B. as copper sulfate • sulfuric acid 32 ml / l (27-37 ml / l) • chloride 60 mg / l (30-120 mg / L), adding z. B. as hydrochloric acid • Other components as specified by the manufacturer Working conditions: • PH value <1 • temperature 22 ° C (20-40 ° C) • current density 5 A / dm ² (3-8 A / dm ² )

The deposition takes place according to the manufacturer.

To produce the alloy layer (3) - z. B. MIRALLOY 2843, Fa. Umicore Galvanotechnik

components: • copper 8.5 g / l (7.5-9.5 g / l) • tin 34 g / l (30-40 g / l) • zinc 1 g / l (0.8-1.2 g / l) • Potassium cyanide 50 g / l free (45-55 g / l) • potassium hydroxide 20 g / l (15-25 g / l) • Other components as specified by the manufacturer Working conditions: • PH value > 13 • temperature 60 C. (58-62 ° C) • current density 2 A / dm ² (1.5-2.5 A / dm ² )

The deposition takes place according to the manufacturer.

To produce the adhesion-promoting copper layer (4b), z. Umicore copper 830, Umicore Galvanotechnik

components • copper 60 g / l (57-63 g / l) • Potassium cyanide 35 g / l free (30-40 g / l) • Other components as specified by the manufacturer Working conditions: • PH value 10.5 (10-11) • temperature 58 ° C (55-60 ° C) • current density 2 A / dm ² (1-3 A / dm ² )

The deposition takes place according to manufacturer's instructions.

To produce the adhesion-promoting gold layer (4c), z. B. AURUNA 311, Umicore Galvanotechnik

components • Gold 2 g / l (2-4 g / l) • Other components as specified by the manufacturer Working conditions: • PH value 0.6 (0.1-0.8) • temperature 35 ° C (20-40 ° C) • current density 3 A / dm ² (2-6 A / dm ² )

The deposition takes place according to manufacturer's instructions.

To produce the adhesion-promoting palladium layer (4d), z. B. PALLUNA 457, Fa. Umicore Galvanotechnik

components • palladium 10 g / l (8-12 g / l) • Other components as specified by the manufacturer Working conditions: • PH value 7.7 (7.2-8.2) • temperature 42 ° C (40-45 ° C) • current density 3 A / dm ² (2-6 A / dm ² )

The deposition takes place according to manufacturer's instructions.

To produce the adhesion-promoting chromium layer (4a), z. B. SLOTOCHROM DR 60, Fa. Schlötter

components • Conducting salt Slotochrom DR 61 260 g / l (235-285 g / l) • Solution Slotochrom DR 62 100 ml / l (90-110 ml / l) • Solution Slotochrom DR 63 10 ml / l (9-11 ml / l) • Other components as specified by the manufacturer Working conditions: • PH value 3.5 (3.3-3.7) • temperature 50 ° C (45-55 ° C) • current density 7 A / dm ² (4-10 A / dm ² )

The deposition takes place according to the manufacturer.

To produce the adhesion-promoting iron layer (4e), Fa. Umicore

components • Palluna ACF-600 Density Correction Salt 130 g / l (100-200 g / l) • Auruna Iron Correction Solution 2 4 ml / l (1-10 ml / l) • buffer substance 55 g / l (20-60 m / l) • Umicore wetting agent 26 1 ml / l (0.1-2 ml / l) • Other components as specified by the manufacturer Working conditions: • PH value 4 (2-5) • temperature 60 C. (20-70 ° C) • current density 5 A / dm ² (1-10 A / dm ² )

The deposition takes place according to the manufacturer.

To produce the chromium layer (5), z. B. SLOTOCHROM DC 150, Fa. Schlötter

components • Chromic acid 150 g / l (125-300 g / l) • Chromium (III) oxide 3 g / l (2-6 g (l) • sulfuric acid 0.4 ml / l (0.27-1.06 ml / l) • Other components as specified by the manufacturer Working conditions: • PH value <1 • temperature 45 ° C (40-50 ° C) • current density 15 A / dm ² (10-25 A / dm ² )

The deposition is according to the manufacturer. Optical appearance compared to standard Type layer sequence Results default Substrate Copper (0.5 μm) Nickel (15 μm) Chromium (5) (0.3 μm) High-gloss, bluish chrome-colored surface Replacement nickel by combination "copper and bronze" Subatrate copper (2), (15 μm) bronze * (3), (4 μm) chromium (5), (0.3 μm) Mouse gray, matte, surface - unusable Replacement Chromium (5) by Chromium (4a) Substrate (1) Copper (2), (15 μm) Bronze * (3), (4 μm) Chromium (4a), (0.2 μm) High-gloss, light gray surface - not suitable, since there is a color difference to standard. Inventive layer sequence Substrate (1) Copper (2), (15 μm) Bronze (3), (4 μm) Chromium (4a), (0.2 μm) Chromium (5), (0.3 μm) High-gloss, bluish, chrome-colored surface - appearance identical to standard Inventive layer sequence Substrate (1) Copper (2), (15 μm) Bronze (3), (4 μm) Copper (4b), (0.2 μm), Chromium (5), (0.3 μm) High-gloss, bluish, chrome-colored surface - appearance identical to standard Inventive layer sequence Substrate (1) Copper (2), (15 μm) Bronze (3), (4 μm) Gold (4c), (0.2 μm) Chromium (5), (0.3 μm) High-gloss, bluish, chrome-colored surface - appearance identical to standard Inventive layer sequence Substrate (1) Copper (2), (15 μm) Bronze (3), (4 μm) Palladium (4d), (0.2 μm) Chromium (5), (0.3 μm) High-gloss, bluish, chrome-colored surface - appearance identical to standard Inventive layer sequence Substrate (1) Copper (2), (15 μm) Bronze (3), (4 μm) Iron (4e), (0.01 μm) Chromium (5), (0.3 μm) High-gloss, bluish, chrome-colored surface - appearance identical to standard Results of corrosion tests A B C layer sequence Substrate (1) Copper (0.5 μm) Nickel (15 μm) Chromium (0.3 μm) Substrate (1) Copper (2), (15 μm) CuSnZn layer (3), (4 μm) Chromium (4a), (0.2 μm) Chromium (5), (0.3 μm) Substrate (1) Copper (2), (15 μm) CuSnZn layer (3), (4 μm) Iron (4e), (0.01 μm) Chromium (5), (0.3 μm) Kesternich test ( DIN 50018) ++ + ++ CASS ( DIN 50021-CASS) ++ - +++ ++ + Temperature change test ( DIN IEC 60747-2) +++ +++ +++ Salt spray test ( DIN 50021-SS) +++ +++ + Rating: +++ ... very good, ++ ... good, + ... ex.
* Bronze = white bronze = alloy layer of copper, tin and zinc or copper and tin.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 1918425 [0002]
• EP 1826296 [0002, 0005]
• DE 102005041375 [0002, 0005]
• EP 2048265 [0002]
• US 4062737 [0006]
• US 3954574 [0006]
• US 4169022 [0006]
• US 4278512 [0006]
• US 5194100 [0006]
• DE 398054 [0007]
• DE 448526 [0007]
• US 4093522 [0007]
• DE 102011008836 [0014]
• DE 102008032398 [0014]
• DE 502007002479 [0014]

Cited non-patent literature

• Gaida et al., Electroplating Technology, Eugen G. Leuze Verlag, 1st Edition, p. 214 [0002]
• EU Directive 94/27 / EC [0003]
• Energy I Water Practice, 2010, 2, p. 16ff. [0003]
• http://www.managermagazin.de/lifestyle/wohnen/0,2828,50123,00.html [0003]
• www.baumarkt.de/nxs/9148///baumarkt/schablone1/Metalle-im-Trinkwasser-ein-Problem-für-Kleinkinder-und-Babys.de [0003]
• IKZ-Haustechnik, issue 12/2001, p. 27ff. [0003]
• Norikazu Sugaya, SLNA Metal Surface Treatment For Rust Prevention and Lead Percolation Resistance of Copper Alloy Piping Materials [0003]
• Galvanic Plating, G. Lausmann, J. Unruh, p. 225 [0005]
• DIN 50021-SS [0005]
• Electroplating Technology, Chap. 5 - Electroplating of plastics, Gaida, Aßmann, 1996, Leuze-Verlag [0013]
• Kupferschichten, Kanani, p. 62ff, 2000, Leuze Verlag [0013]
• Precious metal layers, series Electroplating and Surface Treatment, Hasso Kaiser, Eugen G. Leuze Verlag, 2002 [0015]
• Kupferschichten, Kanani, p. 62ff, 2000, Leuze Verlag [0015]
• Galvanic plating, G. Lausmann, J. Unruh, 2006, Leuze-Verlag [0016]
• On the Electrodeposition of Iron, August Pfaff, Zeitschrift fur Elektrochemie und angewandte Chemie, 1910, Vol. 16, 217-223 [0017]
• Galvanic plating, G. Lausmann, J. Unruh, 2006, Leuze-Verlag [0019]
• Practical Electroplating, Author Team, 1984, Leuze-Verlag [0024]
• Cleaning and degreasing in the metal industry, Jelinek, 1999, Leuze-Verlag [0024]
• DIN 50018) [0042]
• DIN 50021-CASS) [0042]
• DIN IEC 60747-2) [0042]
• DIN 50021-SS) [0042]

Claims (8)

Composite material with a decorative surface consisting essentially of chromium: A substrate (1) consisting of plastic or metal, in particular brass, aluminum, zinc or stainless steel, A coating of at least one metal layer (2) comprising copper with a layer thickness of 0.01-30 μm, A coating of at least one metal layer (3) comprising an alloy of copper, tin and zinc or copper and tin of 0.01-15 μm, A coating as an adhesion-promoting layer of at least one metal layer comprising chromium (4a), copper (4b), gold (4c), palladium (4d) or iron (4e) with a layer thickness of 0.001-0.5 μm, A surface coating essentially of chromium (5) with a layer thickness of 0.01-5 μm, in the case of an adhesion-promoting layer comprising chromium (4a), which is electrolytically deposited from an electrolyte which has chromium predominantly in the 3-valent oxidation state and the upper chromium layer (5) is electrolytically deposited from an electrolyte, the chromium predominantly in the 6 -valent oxidation state. Composite material according to claim 1, characterized in that the electrolyte for the lower chromium layer (4a) has chromium almost exclusively in the 3-valent oxidation state and the electrolyte for the upper chromium layer (5) has chromium predominantly in the 6-valent oxidation state. Composite material according to one or more of the preceding claims, characterized in that the metal layer (2) with a thickness of 1-20 μm, the metal layer (3) with a thickness of 1-5 microns, and the metal layer (4a-d) has a thickness of 0.1-0.4 microns, or the metal layer (4e) has a thickness of 0.001-0.5 μm, wherein the surface coating of substantially chromium (5) has a layer thickness of 0.1-0.5 μm. Method for producing a composite material according to one or more of Claims 1 to 3, characterized in that the adhesion-promoting layer comprises chromium (4a), copper (4b), gold (4c), palladium (4d) or iron (4e). Method according to claim 4, characterized in that you: - On the substrate (1) deposits a base layer of copper electrolytically or electrolessly; - prepare the composite for the next step; - The metal layer (2) comprising copper deposits; - Deposits on this electrolytically a layer (3) consisting of copper and tin or copper, tin and zinc; - Preparing the composite material for the next step The metal layer comprising chromium (4a), copper (4b), gold (4c), palladium (4d) or iron (4e) precipitates; - prepare the composite for the next step; - The metal layer (5) comprising chromium deposits; wherein in the case of the chromium layer (4a), this is electrolytically deposited from an electrolyte which has chromium predominantly in the 3-valent oxidation state and in any case the upper chromium layer (5) is electrolytically deposited from an electrolyte, the chromium predominantly in the hexavalent Has oxidation state. A method according to claim 4 and / or claim 5, characterized in that the deposition of the chromium layer (5) takes place from an aqueous electrolyte which has a pH of less than 1 and contains the following constituents: chromium (IV) oxide, preferably in one Concentration of 240-260 g / l of sulfuric acid, preferably in a concentration of 0.5 wt .-% H ₂ SiF ₆ , preferably in a concentration of 1.5-4 g / l. Use of the composite materials according to one or more of claims 1 to 3 in sanitary facilities. Use of the composite materials according to one or more of claims 1 to 3 for articles which may come into contact with the skin.