EP1587968B1 - Coating method - Google Patents

Abstract

The invention relates to a method for coating objects, particularly sanitary ware such as plumbing fixtures, shower fittings and the like, during which at least one layer made of copper, nickel or of a copper-nickel alloy is firstly applied to the object. The object itself and/or at least the uppermost applied layer are/is then subjected to a mechanical surface treatment, and at least one nickel-tungsten layer and/or at least one palladium-nickel layer are/is applied to the object or the surface-treated layer. The surface treatment preferably ensues by brushing and/or blasting. This enables objects to be provided with a specific appearance, particularly a high-grade steel-like appearance.

Description

The invention relates to methods for coating objects, in particular sanitary articles such as sanitary fittings, sanitary showers and the like, as well as the articles which can be produced by this method.

For a long time a variety of items for various reasons with inorganic or organic substances are coated. Reason for these coatings are on the one hand functional requirements, eg. As the corrosion protection, or other decorative requirements, eg. B. the visual appearance. Frequently, articles are coated for both functional and decorative reasons.

Of particular importance are coatings for all types of sanitary items, especially sanitary fittings. On the one hand, they must meet functional requirements, ie be highly resistant to corrosion, be easy to clean, be scratch-resistant, to name but a few of these requirements. On the other hand, they must meet high decorative demands, ie it must, for example, shiny or matte surfaces are provided with specific "optics". To meet these requirements, a variety of metals are used as coating materials, which are often applied by electrodeposition to the corresponding base body. A well-known example here is the application of chromium, whereby glossy surfaces of high corrosion resistance are obtained.

The problems which occur in the coating of objects, in particular in sanitary engineering, are particularly pronounced in the case of objects made of metal or metal surfaces, but also of plastic or plastic surfaces. Thus, on the one hand, certain metals are either not usable at all or only in coated form for certain applications because of their properties or for cost reasons. On the other hand, in contrast to metals, plastics have a very low heat capacity. Therefore, a mechanical surface treatment of metallized plastic parts is possible only to a limited extent, since otherwise by the resulting heat treatment from the mechanical treatment in the plastic part, the (in particular galvanically applied) metal layers can detach from the plastic surfaces again. This can lead to high reject rates in industrial production.

Furthermore, certain "optics" should be adjustable on all basic bodies. This applies in particular to the so-called "stainless steel look". In such an embodiment, the coated metal part or the metal-coated plastic part should also have the visual impression of a stainless steel surface, in particular a brushed stainless steel surface, if this part is not made of stainless steel or coated with stainless steel. So sanitary fittings are made in many cases, in particular made of brass, zinc die casting or other metals and then coated, especially with metals. Sanitary fittings, sanitary showers or at least the parts belonging to such fittings such as connecting parts, rosettes or connecting parts are also often made of plastic and then coated (with metals). All these parts should then have the mentioned "stainless steel look".

To provide surfaces of certain optics on plastic articles, there are already various approaches in the prior art.

Thus, the desired surface is often imitated by a painting process. The paint contains, for example, aluminum pigments, which are colored accordingly by the addition of dyes. The resulting surfaces are often unsatisfactory in terms of visual appearance and functional properties such as scratch resistance.

In another approach, a copper layer applied to the plastic part is brushed and then nickel plated. This nickel layer is then provided with a transparent protective lacquer. The disadvantage of this method is that damage to the paint layer and the corrosion protection is lost.

As an alternative to the mentioned painting process, it is also possible to apply stainless steel or a stainless steel-like layer to vacuum-chrome-plated plastic parts in a vacuum (PVD process). The resulting surface will then have the color of stainless steel, but not the typical surface texture of brushed stainless steel. Another disadvantage is that the application of metal layers in the PVD process is very expensive.

On the other hand, the shows EP-A2-0410472 a method in which a copper-based layer is first provided with a nickel-based layer to make an electrical contact, and then a palladium-based layer is subsequently deposited thereon. In this case, the nickel-based layer having a thickness of at least 0.8 μm is formed to include a non-crystalline nickel alloy layer having a thickness of at least 0.08 μm. This can be thinner palladium-based outer layers provide, resulting in a cost reduction for the production of the electrical contact material.

A mechanical surface treatment by brushing and / or blasting is at the EP-A2-0410472 not provided. The appearance of the obtained electrical contact is also addressed in this document at any point.

The object of the invention is, inter alia, to provide a coating method for objects, in particular sanitary articles, in which a specific optical appearance of the coated article can be achieved in a targeted manner. In particular, the invention is intended to provide a method of providing a coated article having the visual appearance of brushed stainless steel. In this case, the coated object with this optics should meet the functional requirements placed on it, in particular in sanitary engineering.

This object is achieved by the methods having the features of claims 1 and 2 and by the subject-matter having the features of claims 11 and 12. Preferred embodiments of these methods or objects are illustrated in the dependent claims 3 to 10 and 13 to 38. The wording of all claims is hereby incorporated by reference into the content of this specification

According to the invention, the above-mentioned processes are characterized in that at least one layer of copper, nickel or a copper-nickel alloy is optionally applied to the article. The article and / or at least the topmost applied layer is mechanically surface treated. Then at least one nickel-tungsten layer with a tungsten content of about 30 and 40 atomic percent of bisphenols and / or at least one palladium-nickel layer with a content of at least 70 atomic percent of palladium is applied.

The above-mentioned surface treatment is carried out by brushing and / or blasting. It is further preferred if the surface treatment in each case takes place at least partially by brushing.

In this case, brushing is to be understood as a mechanical surface treatment in which the surface is processed with a brush or an equivalent working agent of sufficient strength and hardness with partial removal of the metal layer. By this process, the characteristic structures such as grooves, depressions and the like are incorporated into the surface, as they are characteristic for such known to those skilled machining with brushes. Of course, if necessary, the brushed metal layer in question is not completely removed.

Radiation is understood by the person skilled in the art to be a mechanical surface treatment in which, for example, (quartz) sand or glass beads are thrown as abrasive (diameter usually 0.5 to 1.5 mm) onto the corresponding surface with the aid of compressed air blowers. This results in the surface structures characteristic of the radiation.

As already mentioned, brushing and blasting can be used alternatively or in combination in the invention. Preferably, at least a part of the surface to be treated is brushed, in which case in particular the parts of the surface which are difficult to reach and to be processed with the brush / brush disk are blasted.

The applied layers of copper, nickel or copper-nickel alloys are inventively preferably comparatively "soft" formed so that a simple mechanical surface treatment, in particular by brushing, is made possible. Copper layers, in particular electrodeposited copper layers, are usually sufficiently soft. In the case of nickel layers, the so-called sulfamate nickel known to the person skilled in the art is to be emphasized as being preferred, which is deposited from a sulfamate-based nickel bath (without organic additives) as a soft matt nickel.

The process according to the invention is preferably designed such that a copper layer and then a nickel layer are applied to the article first. This nickel layer is then mechanically surface treated, preferably brushed and / or blasted.

According to the invention, the nickel layers are in particular so-called sulfamate nickel layers, ie. H. soft matt nickel layers, as known in the art.

According to the invention, it is further preferred if on the surface-treated article / base body or on the surface-treated layer prior to application of the nickel-tungsten layer or palladium-nickel layer, at least one further layer of copper, nickel or a copper-nickel alloy is applied. Such further layers, depending on the metal used, may increase the corrosion resistance or cause particular optical effects in the finally obtained coated article. The further layer is preferably a nickel layer, in particular a so-called sulfamate nickel layer.

As already partially apparent from the statements made so far, according to the invention, the layers of the metals mentioned are preferably at least partially removed by electrodeposition, ie. H. by deposition from an electrolyte under current flow. Preferably, all metal layers applied to the article are electrodeposited. In this case, a per se non-conductive plastic article is made conductive by methods known in the art. For example, the plastic surface is electrolessly activated with palladium and metallized electrolessly with nickel. Optionally, a so-called pre-nickel layer can be applied to the thin nickel layer thus obtained by deposition under current flow. The basic structure thus obtained is then further treated according to the invention.

In a further development, it is preferred in the process according to the invention if at least one siloxane or polysiloxane covering layer is applied over the (optionally uppermost) nickel-tungsten layer or palladium-nickel layer is applied. Siloxanes / polysiloxanes are known to be obtained from organosilanes, for example by thermal treatment. Particularly suitable for this purpose is the so-called sol-gel process, which leads to the polysiloxane layers known in the literature under the heading "sol-gel coatings". Such a cover layer provides additional surface sealing and can improve its physical and chemical properties (eg, in terms of abrasion resistance, corrosion resistance, liquid bead-off effect, and the like). Although suitably pigmented polysiloxane layers are possible according to the invention, the cover layer will generally be a transparent polysiloxane layer.

It is understood that the object to be coated can be subjected to a conventional pretreatment prior to carrying out the method according to the invention. Such pretreatment steps are known to the person skilled in the art. Here are the usual chemical and / or physical methods that can be cited under the keywords anodic degreasing, cathodic degreasing, Heißentfettung, ultrasonic degreasing and the like. Such known pretreatment and activation steps can of course also be applied between the individual process steps, for example before the application of further metal layers.

The object according to the invention, ie preferably the sanitary article according to the invention such as a sanitary fitting, sanitary shower and the like, according to the invention consists of a base body. On this body is optionally at least one layer of copper, nickel or a copper-nickel alloy. The main body and / or optionally the uppermost layer is mechanically surface-treated. Above the surface-treated base body or the uppermost (surface-treated) layer is then at least one Nickel-tungsten layer with a tungsten content of between 30 and 40 atomic percent and / or at least one palladium-nickel layer with a palladium content of at least 70 atomic percent. Depending on the design, the base body is made of metal or has metal surfaces (no stainless steel) or it is made of plastic or has plastic surfaces.

The main body or the uppermost layer on which the nickel-tungsten layer and / or palladium-nickel layer is located is in particular brushed and / or blasted. With regard to the surface structures defined therewith, reference is explicitly made to the above statements and proven.

In a further development, in the article according to the invention preferably at least one further layer of copper, nickel or a copper-nickel alloy between the surface-treated base body or the surface-treated layer and the nickel-tungsten layer or palladium-nickel layer.

1. 1. Gegenstand mit
   • einem Grundkörper aus Metall oder einem Grundkörper mit metallischen Oberflächen (kein Edelstahl), wobei dieser Grundkörper mechanisch oberflächenbehandelt, vorzugsweise gebürstet ist, und
   • eine Nickel-Wolfram-Schicht mit einem Wolframanteil Zuischen 30 und 40 Atomprozent auf dem oberflächenbehandelten Grundkörper.
2. 2. Gegenstand mit
   • einem Grundkörper aus Metall oder einem Grundkörper mit metallischen Oberflächen (kein Edelstahl), wobei dieser Grundkörper mechanisch oberflächenbehandelt, vorzugsweise gebürstet ist, und
   • einer Nickelschicht, vorzugsweise Sulfamatnickelschicht, auf dem oberflächenbehandelten Grundkörper, und
   • einer sich auf der Nickelschicht befindenden Palladium-Nickel-Schicht mit einem Palladiumanteil von mindestens 70 Atomprozent.
3. 3. Gegenstand mit
   • einem Grundkörper aus Metall oder einem Grundkörper mit metallischen Oberflächen (kein Edelstahl),
   • einer sich auf dem Grundkörper befindenden Schicht aus Kupfer oder Nickel, wobei
     • diese Kupferschicht oder Nickelschicht mechanisch oberflächenbehandelt, vorzugsweise gebürstet ist, und
   • einer Nickel-Wolfram-Schicht mit einem Wolframanteil zwischen 30 und 40 Atomprozent und/oder Palladium-Nickel-Schicht mit einem Palladiumanteil von mindestens 70 Atomprozent auf der oberflächenbehandelten Kupferschicht oder Nickelschicht.
4. 4. Gegenstand mit
   • einem Grundkörper aus Metall oder einem Grundkörper mit metallischen Oberflächen (kein Edelstahl),
   • einer sich auf dem Grundkörper befindenden Kupferschicht,
   • einer sich auf der Kupferschicht befindenden Nickelschicht, wobei
     • diese Nickelschicht mechanisch oberflächenbehandelt, vorzugsweise gebürstet ist, und
   • einer Nickel-Wolfram-Schicht mit einem Wolframanteil zwischen 30 und 40 Atomprozent und/oder einer Palladium-Nickel-Schicht mit einem Pallodiumanteil von mindestens 70 Atomprozent auf der oberflächenbehandelten Nickel-schicht.
   
   Bei dem unter 4. definierten Gegenstand kann sich zwischen der oberflächenbehandelten Nickelschicht und der Nickel-Wolfram-Schicht bzw. Palladium-Nickel-Schicht vorzugsweise eine weitere Nickelschicht befinden.
5. 5. Gegenstand mit
   • einem Grundkörper aus Kunststoff oder einem Grundkörper mit Kunststoffoberflächen,
   • einer sich auf dem Grundkörper befindenden Schicht aus Kupfer oder Nickel, wobei
     • diese Kupferschicht oder Nickelschicht mechanisch oberflächenbehandelt, vorzugsweise gebürstet ist, und
   • einer Nickel-Wolfram-Schicht mit einem Wolframanteil zwischen 30 und 40 Atomprozent auf der oberflächenbehandelten Kupferschicht oder Nickelschicht.
6. 6. Gegenstand mit
   • einem Grundkörper aus Kunststoff oder einem Grundkörper mit Kunststoffoberflächen
   • einer sich auf dem Grundkörper befindenden Kupferschicht,
   • einer sich auf der Kupferschicht befindenden Nickelschicht, wobei
     • diese Nickelschicht mechanisch oberflächenbehandelt, vorzugsweise gebürstet ist, und
   • einer Nickel-Wolfram-Schicht mit einem Wolframanteil zwischen 30 und 40 Atomprozent auf der oberflächenbehandelten Nickelschicht.
7. 7. Gegenstand mit
   • einem Grundkörper aus Kunststoff oder einem Grundkörper mit Kunststoffoberflächen,
   • einer sich auf dem Grundkörper befindenden Schicht aus Kupfer oder Nickel, wobei
   • diese Kupferschicht ode Nickelschicht mechanisch oberflächenbehandelt, vorzugsweise gebürstet ist, und
   • einer Palladium-Nickel-Schicht mit einem Palladiumanteil von mindestens 70 Atomprozent auf der oberflächenbehandelten Kupferschicht oder Nickelschicht.
8. 8. Gegenstand mit
   • einem Grundkörper aus Kunststoff oder einem Grundkörper mit Kunststoffoberflächen,
   • einer sich auf dem Grundkörper befindenden Kupferschicht,
   • einer sich auf der Kupferschicht befindenden Nickelschicht, wobei
     • diese Nickelschicht mechanisch oberflächenbehandelt, vorzugsweise gebürstet ist, und
   • einer Palladium-Nickel-Schicht mit einem Palladinmanteil von mindestens 70 Atomprozent auf der oberflächenbehandelten Nickelschicht.

Accordingly, in accordance with the above statements, it is possible to characterize preferred articles according to the invention by the following structure:

1. 1. Item with
   • a base body made of metal or a base body with metallic surfaces (not stainless steel), said base body being mechanically surface-treated, preferably brushed, and
   • a nickel-tungsten layer with a tungsten content of 30 and 40 atomic percent on the surface-treated base body.
2. 2. Item with
   • a basic body of metal or a basic body with metallic surfaces (not stainless steel), whereby this Main body is mechanically surface-treated, preferably brushed, and
   • a nickel layer, preferably sulfamate nickel layer, on the surface-treated base body, and
   • a palladium-nickel layer on the nickel layer with a palladium content of at least 70 atomic percent.
3. 3. Item with
   • a base made of metal or a basic body with metallic surfaces (not stainless steel),
   • a located on the body layer of copper or nickel, wherein
     • this copper layer or nickel layer is mechanically surface-treated, preferably brushed, and
   • a nickel-tungsten layer having a tungsten content between 30 and 40 atomic percent and / or palladium-nickel layer with a palladium content of at least 70 atomic percent on the surface-treated copper layer or nickel layer.
4. 4. Item with
   • a base made of metal or a basic body with metallic surfaces (not stainless steel),
   • a copper layer located on the base body,
   • a layer of nickel on the copper layer, wherein
     • this nickel layer is mechanically surface-treated, preferably brushed, and
   • a nickel-tungsten layer having a tungsten content of between 30 and 40 atomic percent and / or a palladium-nickel layer having a pallodium content of at least 70 atomic percent on the surface-treated nickel layer.
   
   In the case defined under item 4, a further nickel layer may preferably be present between the surface-treated nickel layer and the nickel-tungsten layer or palladium-nickel layer.
5. 5. Item with
   • a basic body made of plastic or a basic body with plastic surfaces,
   • a located on the body layer of copper or nickel, wherein
     • this copper layer or nickel layer is mechanically surface-treated, preferably brushed, and
   • a nickel-tungsten layer having a tungsten content of between 30 and 40 atomic percent on the surface-treated copper layer or nickel layer.
6. 6. Item with
   • a basic body made of plastic or a basic body with plastic surfaces
   • a copper layer located on the base body,
   • a layer of nickel on the copper layer, wherein
     • this nickel layer is mechanically surface-treated, preferably brushed, and
   • a nickel-tungsten layer having a tungsten content of between 30 and 40 atomic percent on the surface-treated nickel layer.
7. 7. Item with
   • a basic body made of plastic or a basic body with plastic surfaces,
   • a located on the body layer of copper or nickel, wherein
   • this copper layer or nickel layer is mechanically surface-treated, preferably brushed, and
   • a palladium-nickel layer having a palladium content of at least 70 atomic percent on the surface-treated copper layer or nickel layer.
8. 8. Item with
   • a basic body made of plastic or a basic body with plastic surfaces,
   • a copper layer located on the base body,
   • a layer of nickel on the copper layer, wherein
     • this nickel layer is mechanically surface-treated, preferably brushed, and
   • a palladium-nickel layer having a palladium content of at least 70 atomic percent on the surface-treated nickel layer.

In all objects defined under 3. and 4., the surface-treated nickel layer may preferably be a so-called sulfamate nickel layer. Such nickel layers are known to those skilled in the art as soft matt nickel layers. The copper layers mentioned under 3. and 4. are preferably matte copper layers.

In the case of the objects defined under 6. and 8., a further nickel layer may preferably be present between the surface-treated nickel layer and the nickel-tungsten / palladium-nickel layer.

In all objects defined under 5. to 8., the surface-treated nickel layer may preferably be a so-called sulfamate nickel layer. Such nickel layers are the Professional known as soft matt nickel layers. The copper layers mentioned under 5. to 8. are preferably matt copper layers.

If there are further nickel layers (between surface-treated base body or surface-treated layer and nickel-tungsten layer or palladium-nickel layer), these are preferably also so-called sulfamate nickel layers.

In all embodiments according to the invention of the article according to the invention, there can be (at least) one siloxane / polysiloxane covering layer over the (optionally uppermost) nickel-tungsten layer or palladium-nickel layer.

• ein Grundkörper aus Metall oder ein Grundkörper mit metallischen Oberflächen,
• einer sich auf dem Grundkörper befindenden Kupferschicht,
• einer sich auf der Kupferschicht befindenden Nickelschicht, vorzugsweise Sulfamatnickelschicht, die mechanisch oberflächenbehandelt, vorzugsweise gebürstet ist,
• einer sich auf der oberflächenbehandelten Nickelschicht befindenden weitere Nickelschicht, vorzugsweise Sulfamatnickelschicht,
• einer sich auf dieser weiteren Nickelschicht befindenden Nickel-Wolfram-Schicht mit einem Wolfromanteil zwischen 30 und 40 Atomprozent, und/oder Palladium-Nickel-Schicht mit einem Palladiumanteil von mindestens 70 Atomprozent, und
• einer sich auf der Nickel-Wolfram-Schicht und/oder Palladium-Nickel-Schicht befindenden Polysiloxan-Deckschicht.

Accordingly, a particularly preferred subject of the invention is defined by the following structure:

• a basic body made of metal or a basic body with metallic surfaces,
• a copper layer located on the base body,
• a nickel layer on the copper layer, preferably a sulfamate nickel layer, which is mechanically surface-treated, preferably brushed,
• a further nickel layer located on the surface-treated nickel layer, preferably a sulfamate nickel layer,
• a nickel-tungsten layer on this further nickel layer with a tungsten proportion between 30 and 40 atomic percent, and / or palladium-nickel layer with a palladium content of at least 70 atomic percent, and
• a polysiloxane cap layer located on the nickel-tungsten layer and / or palladium-nickel layer.

• ein Grundkörper aus Kunststoff oder ein Grundkörper mit Kunststoffoberflächen,
• einer sich auf dem Grundkörper befindenden Kupferschicht,
• einer sich auf der Kupferschicht befindenden Nickelschicht, vorzugsweise Sulfamatnickelschicht, die mechanisch oberflächenbehandelt, vorzugsweise gebürstet ist,
• einer sich auf der oberflächenbehandelten Nickelschicht befindenden weiteren Nickelschicht, vorzugsweise Sulfamatnickelschicht,
• einer sich auf dieser weiteren Nickelschicht befindenden Nickel-Wolfram-Schicht mit einem Wolfromanteil zwischen 30 und 40 Atomprozent, und
• einer sich auf der Nickel-Wolfram-Schicht befindenden Polysiloxan-Deckschicht.

Another particularly preferred subject of the invention is defined by the following structure:

• a base body made of plastic or a base body with plastic surfaces,
• a copper layer located on the base body,
• a nickel layer on the copper layer, preferably a sulfamate nickel layer, which is mechanically surface-treated, preferably brushed,
• a further nickel layer located on the surface-treated nickel layer, preferably a sulfamate nickel layer,
• a nickel-tungsten layer having a tungsten content of between 30 and 40 atomic percent, located on this further nickel layer, and
• a polysiloxane overcoat layer on the nickel-tungsten layer.

• ein Grundkörper aus Kunststoff oder ein Grundkörper mit Kunststoffoberflächen,
• einer sich auf dem Grundkörper befindenden Kupferschicht,
• einer sich auf der Kupferschicht befindenden Nickelschicht, vorzugsweise Sulfamatnickelschicht, die mechanisch oberflächenbehandelt, vorzugsweise gebürstet ist,
• einer sich auf der oberflächenbehandelten Nickelschicht befindenden weiteren Nickelschicht, vorzugsweise Sulfamatnickelschicht,
• einer sich auf dieser weiteren Nickelschicht befindenden Palladium-Nickel-Schicht mit einem Palladiumanteil von mindestens 70 Atomprozent, und
• einer sich auf der Palladium-Nickel-Schicht befindenden Polysiloxan-Deckschicht.

Yet another particularly preferred subject of the invention is defined by the following structure:

• a base body made of plastic or a base body with plastic surfaces,
• a copper layer located on the base body,
• a nickel layer on the copper layer, preferably a sulfamate nickel layer, which is mechanically surface-treated, preferably brushed,
• a further nickel layer located on the surface-treated nickel layer, preferably a sulfamate nickel layer,
• a palladium-nickel layer having a palladium content of at least 70 atomic percent and located on this further nickel layer, and
• a polysiloxane capping layer located on the palladium-nickel layer.

In the invention, the palladium content of the palladium-nickel layers is at least 70 atomic percent. Further preferred is a palladium content of about 80 atomic percent. Due to the highlighted high palladium content of the resulting layers have a particularly good corrosion resistance, which may even be higher than stainless steel.

In principle, the layer thicknesses of the coatings applied to the article are not critical. However, in order to perform their function particularly well, there are preferred ranges for these respective layer thicknesses. Thus, the layer thickness of the first metal layer located on the object is between 10 μm and 60 μm, preferably between 20 μm and 50 μm. Within this latter range, layer thicknesses between 30 .mu.m and 40 .mu.m are more preferred.

The layer thickness of the nickel layers, preferably of the (further) nickel layers located on a surface-treated layer, is preferably between 5 μm and 25 μm, preferably between 5 μm and 15 μm. Here, within the last-mentioned range, layer thicknesses between 6 μm and 10 μm should be particularly emphasized.

The layer thicknesses of the nickel-tungsten layer (s) or palladium-nickel layer (s) are also not critical, but are chosen as small as possible (for example, less than 20 microns). So are layer thicknesses between 0.1 μm and 5 μm. Within this range, layer thicknesses between 0.2 μm and 2 μm, in particular between 0.5 μm and 1 μm, are more preferred.

The layer thickness of the siloxane / polysiloxane layer (s) is preferably less than 5 μm, in particular less than 1 μm.

In principle, all known and in particular usually industrially used metals (with the exception of stainless steel) can be coated according to the invention. In this case, the article may either itself consist of the corresponding metal, or the metal may form at least a part of the surface of this article. In the invention, basic bodies of metals are preferably used, as used in sanitary engineering. Special mention should be made here of aluminum, zinc (die casting) and in particular brass body.

According to the invention, it is possible in principle to coat all known and, in particular, usually industrially used (electroplatable) plastics. In this case, the article either itself consist of the corresponding plastic material or the plastic material may form at least a part of the surface of this article. Preferably, in the invention basic body made of plastics are used, as they are used in sanitary technology. In particular, this plastic is ABS (acrylonitrile-butadiene-styrene copolymer). Also PA (polyamide) and ABS / PC (ABS copolymer with polycarbonate) are to be emphasized.

In accordance with the object set in the subject invention has a so-called stainless steel appearance, ie a stainless steel-like appearance for the viewer. Preferably This stainless steel look is that of "brushed stainless steel".

The method according to the invention and the subject matter according to the invention provide a solution to the problem described above. The object according to the invention fulfills, in particular when it comes to a sanitary object, both the functional requirements imposed on it and the decorative requirements placed on it. The article is therefore on the one hand, inter alia, corrosion resistant, resistant to abrasion, can bead off liquids well and has firmly adhering surface layers. On the other hand, it conveys the desired stainless steel look for the buyer / user, so that objects coated in this way do not stand out optically from articles made of solid stainless steel or indeed articles coated with stainless steel.

The above and other features of the invention will become apparent from the description of the following examples in conjunction with the claims. The individual features can be realized individually or in combination with each other.

Examples A. For the coating of sanitary objects basic bodies of a brass fitting are provided.

• Im ersten Fall wird der (im polierten Zustand vorliegende) Messing-Grundkörper direkt einer mechanischen Oberflächenbehandlung unterworfen, nämlich gebürstet und sandgestrahlt. Dann wird auf den so oberflächenbehandelten Grundkörper direkt eine Nickel-Wolfram-Schicht aufgebracht.
• Im zweiten Fall wird der (im polierten Zustand vorliegende) Messing-Grundkörper ebenfalls direkt gebürstet und sandgestrahlt. Auf den oberflächenbehandelten Grundkörper wird dann zunächst eine Sulfamatnickelschicht aufgebracht und auf diese Nickelschicht dann eine Palladium-Nickel-Schicht.
• Im dritten Fall wird auf den (im polierten Zustand vorliegenden) Messing-Grundkörper zunächst eine Kupferschicht und dann eine Sulfamatnickelschicht aufgebracht. Die so erhaltene Nickeloberfläche wird anschließend gebürstet und sandgestrahlt. Auf die gebürstete/sandgestrahlte Oberfläche wird nach der mechanischen Oberflächenbehandlung eine weitere Sulfamatnickelschicht aufgalvanisiert. Auf diese Nickelschicht wird dann entweder eine Nickel-Wolfram-Schicht oder eine Palladium-Nickel-Schicht aufgebracht.

With such brass bodies, the following coating processes are carried out:

• In the first case, the (in the polished state) brass base body is subjected directly to a mechanical surface treatment, namely brushed and sandblasted. Then, a nickel-tungsten layer is applied directly to the thus surface-treated base body.
• In the second case, the (in the polished state) brass base body is also directly brushed and sandblasted. On the surface-treated base body, a sulfamate nickel layer is then first applied and then a palladium-nickel layer on this nickel layer.
• In the third case, a copper layer and then a sulfamate nickel layer are first applied to the (in the polished state) brass base body. The nickel surface thus obtained is then brushed and sandblasted. On the brushed / sandblasted surface after the mechanical surface treatment, another sulfamate nickel layer is galvanized. On top of this nickel layer is then applied either a nickel-tungsten layer or a palladium-nickel layer.

In all cases, a commercially available brushing disk is used for the brushing, which is suitable for applying a brush structure typical of stainless steel parts with the corresponding grooves, depressions and the like. Those parts of the brass body, which can not be processed well with the brush disk, such. B. narrow transitions are processed by sandblasting.

The nickel-tungsten layers obtained in the first and third case are electrodeposited from a corresponding electrolyte. The thickness of the nickel-tungsten layers is about 1 micron. The tungsten content of these layers is 40 atomic percent.

The applied in the cases two and three sulfamate nickel layers are electrodeposited with layer thicknesses of about 10 microns from a corresponding electrolyte. The first applied copper layers in the third case are also obtained galvanically from a corresponding electrolyte with layer thicknesses of about 40 microns.

The applied in the third case, palladium-nickel layers are also plated in layer thicknesses of about 1 micron from a corresponding electrolyte. The palladium content of these layers is 80 atomic percent.

In further embodiments, the above metal-coated parts are still sealed with a polysiloxane layer (layer thickness about 0.5 microns).

In all cases, the resulting hued tonal structure is identical to that of stainless steel and, secondly, the resulting (mechanically treated) surface texture is that of brushed stainless steel. Thus, the coated parts according to the invention are optically not to be distinguished from parts made of solid stainless steel or parts coated with stainless steel itself.

In cases in which a surface seal with polysiloxane takes place, this final covering layer does not affect the visual appearance and the feel of the articles according to the invention. However, excellent beading properties or dirt-repellent properties are achieved by this cover layer. Because of the brushed / sandblasted surface structure, the polysiloxane cover layer is particularly easy to apply to the objects according to the invention and adheres particularly well to these metal-coated objects.

B. For coating a sanitary object, the main body of a shower head made of the plastic material ABS (acrylonitrile-butadiene-styrene copolymer) is provided.

This plastic part is coated in the usual way with copper (layer thickness about 40 microns). On this copper layer, a so-called sulfamate nickel layer (nickel matt) is electrodeposited (layer thickness about 10 microns). The nickel surface thus obtained is then brushed and sandblasted. For the brushing, a commercially available brushing disc is used which is suitable for applying a brush structure typical of stainless steel parts with the corresponding grooves, recesses and the like. Those parts of the plastic part that can not be processed well with the brushing disk, such. B. narrow transitions are processed by sandblasting. After these mechanical surface treatments a matte, well surface-structured metal-coated plastic part is obtained.

On the brushed / sandblasted surface after the mechanical surface treatment, another sulfamate nickel layer is galvanized. This layer has in the present case a thickness of about 8 microns.

• 84,6 g/l Natriumwolframatdihydrat
• 28,8 g/l Nickelsulfathexahydrat
• 112 g/l Zitronensäuremonohydrat
• 17,7 gl/ Ammoniumchlorid.

An approximately 1 μm thick nickel-tungsten layer of an electrolyte according to the invention is then electroplated onto this nickel layer. The tungsten content of this layer is 40 atomic percent. The electrolyte used contains the following components:

• 84.6 g / l sodium tungstate dihydrate
• 28.8 g / l nickel sulfate hexahydrate
• 112 g / l citric acid monohydrate
• 17.7 g / ammonium chloride.

This electrolyte is also suitable for other applications for the deposition of nickel-tungsten layers.

The resulting layer structure is identical in color to that of stainless steel and on the other hand, the obtained (mechanically treated) surface structure of that of brushed stainless steel. Thus, the plastic parts coated according to the invention are optically indistinguishable from parts made from the solid material stainless steel or from plastic parts coated with stainless steel.

In a final operation, the metal-coated plastic part is sealed with a polysiloxane layer (layer thickness about 0.5 μm). This final cover does not affect the visual appearance and feel of the subject invention. However, excellent beading properties or dirt-repellent properties are achieved by this cover layer. The polysiloxane cover layer is particularly easy to apply to the metal-coated article due to the brushed / sandblasted surface structure and also adheres particularly well to this metal-coated article.

C. For coating a sanitary object, the main body of a shower head made of the plastic material ABS (acrylonitrile-butadiene-styrene copolymer) is provided.

This plastic part is coated in the usual way with copper (layer thickness about 40 microns). On this copper layer, a so-called sulfamate nickel layer (nickel matt) is electrodeposited (layer thickness about 10 microns). The nickel surface thus obtained is then brushed and sandblasted.

For the brushing, a commercially available brushing disk is used which is suitable for applying a brush structure typical of stainless steel parts with the corresponding grooves, recesses and the like. Those parts of the plastic part that can not be processed well with the brushing disk, such. B. narrow transitions are processed by sandblasting. After these mechanical surface treatments a matte, well surface-structured metal-coated plastic part is obtained.

On the brushed / sandblasted surface a so-called sulfamate nickel layer is electroplated after the mechanical surface treatment. This layer has in the present case a thickness of about 8 microns. On this nickel layer then an approximately 1 micron thick palladium-nickel layer is galvanized. The palladium content of this layer is 80 atomic percent, so that excellent corrosion properties are achieved. The corrosion resistance is even better than that of stainless steel. The resulting layer structure is on the one hand identical in color tone to that of stainless steel and on the other hand, the resulting (mechanically treated) surface structure corresponds to that of brushed stainless steel. Thus, the plastic parts coated according to the invention are optically indistinguishable from parts made from the solid material stainless steel or from plastic parts coated with stainless steel.

In a final operation, the metal-coated plastic part is sealed with a polysiloxane layer (layer thickness about 0.5 μm). This final cover does not affect the visual appearance and feel of the subject invention. However, there are excellent Abperleigenschaften or dirt-repellent properties through this cover layer reached. The polysiloxane cover layer is particularly easy to apply to the metal-coated article due to the brushed / sandblasted surface structure and also adheres particularly well to this metal-coated article.

Claims (38)

1. Method for coating objects, particularly sanitary ware such as plumbing fixtures, shower fittings and the like, the objects consisting of metal or having metal surfaces, with the exception of high-grade steel as a metal, wherein

   - optionally at least one layer of copper, nickel or a copper-nickel alloy is applied to the object,

   - the object and/or at least the uppermost applied layer is mechanically surface-treated by brushing and/or blasting, and

   - at least one nickel-tungsten layer and/or at least one palladium-nickel layer is applied, the tungsten fraction of the nickel-tungsten layer being between 30 and 40 atomic percent and the palladium fraction of the palladium-nickel layer being at least 70 atomic percent.
2. Method for coating objects, particularly sanitary ware such as plumbing fixtures, shower fittings and the like, the objects consisting of plastic or having plastic surfaces, wherein

   - optionally at least one layer of copper, nickel or a copper-nickel alloy is applied to the object,

   - the object and/or at least the uppermost applied layer is mechanically surface-treated by brushing and/or blasting, and

   - at least one nickel-tungsten layer and/or at least one palladium-nickel layer is applied, the tungsten fraction of the nickel-tungsten layer being between 30 and 40 atomic percent and the palladium fraction of the palladium-nickel layer being at least 70 atomic percent.
3. Method according to Claim 1 or Claim 2, characterized in that at least the uppermost applied layer is mechanically surface-treated.
4. Method according to one of the preceding claims, characterized in that the surface treatment is performed by sand-blasting.
5. Method according to one of the preceding claims, characterized in that initially a copper layer and then a nickel layer is applied to the object and this nickel layer is mechanically surface-treated.
6. Method according to one of the preceding claims, characterized in that the nickel layer is a so-called sulfamate nickel layer.
7. Method according to one of the preceding claims, characterized in that, before application of the nickel-tungsten layer or the palladium-nickel layer, at least one further layer of copper, nickel or a copper-nickel alloy is applied to the surface-treated object and/or to the surface-treated layer.
8. Method according to Claim 7, characterized in that the further layer is a nickel layer, preferably a so-called sulfamate nickel layer.
9. Method according to one of the preceding claims, characterized in that the applied metal layers are at least partly, preferably all, applied by electrodepositing.
10. Method according to one of the preceding claims, characterized in that at least one siloxane and/or polysiloxane top layer is applied over the nickel-tungsten layer or the palladium-nickel layer.
11. Object, preferably sanitary ware such as a plumbing fixture, shower fitting and the like, the object consisting of metal or having metal surfaces, with the exception of high-grade steel as a metal, characterized in that it is constructed as follows:

    - a base body,

    - optionally at least one layer of copper, nickel or a copper-nickel alloy located on the base body,

    - the base body and/or at least the optionally uppermost layer being mechanically surface-treated by brushing and/or blasting, and

    - at least one nickel-tungsten layer and/or at least one palladium-nickel layer over the surface-treated base body or over the surface-treated uppermost layer, the tungsten fraction of the nickel-tungsten layer being between 30 and 40 atomic percent and the palladium fraction of the palladium-nickel layer being at least 70 atomic percent.
12. Object, preferably sanitary ware such as a plumbing fixture, shower fitting and the like, the object consisting of plastic or having plastic surfaces, characterized in that it is constructed as follows:

    - a base body,

    - optionally at least one layer of copper, nickel or a copper-nickel alloy located on the base body,

    - the base body and/or at least the optionally uppermost layer being mechanically surface-treated by brushing and/or blasting, and

    - at least one nickel-tungsten layer and/or at least one palladium-nickel layer over the surface-treated base body or over the surface-treated uppermost layer, the tungsten fraction of the nickel-tungsten layer being between 30 and 40 atomic percent and the palladium fraction of the palladium-nickel layer being at least 70 atomic percent.
13. Object according to Claim 11 or Claim 12, characterized in that at least the uppermost applied layer is mechanically surface-treated.
14. Object according to one of Claims 11 to 13, characterized in that the base body or the uppermost layer is sand-blasted.
15. Object according to one of Claims 11 to 14, characterized by at least one further layer of copper, nickel or a copper-nickel alloy between the surface-treated base body or the surface-treated layer and the nickel-tungsten layer and/or the palladium-nickel layer.
16. Object according to one of Claims 11 or 13 to 15, characterized in that it is constructed as follows:

    - a base body of metal or a base body with metallic surfaces, with the exception of high-grade steel as a metal, and the base body being mechanically surface-treated, preferably brushed, and

    - a nickel-tungsten layer having a tungsten fraction between 30 and 40 atomic percent on the surface-treated base body.
17. Object according to one of Claims 11 or 13 to 15, characterized in that it is constructed as follows:

    - a base body of metal or a base body with metallic surfaces, with the exception of high-grade steel as a metal, and the base body being mechanically surface-treated, preferably brushed, and

    - a nickel layer, preferably a sulfamate nickel layer, on the surface-treated base body, and

    - a palladium-nickel layer having a palladium fraction of at least 70 atomic percent located on the nickel layer.
18. Object according to one of Claims 11 or 13 to 15, characterized in that it is constructed as follows:

    - a base body of metal or a base body with metallic surfaces, with the exception of high-grade steel as a metal,

    - a layer of copper or nickel located on the base body, this copper layer or nickel layer being mechanically surface-treated, preferably brushed, and

    - a nickel-tungsten layer and/or a palladium-nickel layer on the surface-treated copper layer or nickel layer, the tungsten fraction of the nickel-tungsten layer being between 30 and 40 atomic percent and the palladium fraction of the palladium-nickel layer being at least 70 atomic percent.
19. Object according to Claims 11 or 13 to 15, characterized in that it is constructed as follows:

    - a base body of metal or a base body with metallic surfaces, with the exception of high-grade steel as a metal,

    - a copper layer located on the base body,

    - a nickel layer located on the copper layer, this nickel layer being mechanically surface-treated, preferably brushed, and

    - a nickel-tungsten layer and/or a palladium-nickel layer on the surface-treated nickel layer, the tungsten fraction of the nickel-tungsten layer being between 30 and 40 atomic percent and the palladium fraction of the palladium-nickel layer being at least 70 atomic percent.
20. Object according to one of Claims 12 to 15, characterized in that it is constructed as follows:

    - a base body of plastic or a base body with plastic surfaces,

    - a layer of copper or nickel located on the base body, this copper layer or nickel layer being mechanically surface-treated, preferably brushed, and

    - a nickel-tungsten layer having a tungsten fraction between 30 and 40 atomic percent on the surface-treated copper layer or nickel layer.
21. Object according to one of Claims 12 to 15, characterized in that it is constructed as follows:

    - a base body of plastic or a base body with plastic surfaces,

    - a copper layer located on the base body,

    - a nickel layer located on the copper layer, this nickel layer being mechanically surface-treated, preferably brushed, and

    - a nickel-tungsten layer having a tungsten fraction between 30 and 40 atomic percent on the surface-treated nickel layer.
22. Object according to one of Claims 12 to 15, characterized in that it is constructed as follows:

    - a base body of plastic or a base body with plastic surfaces,

    - a layer of copper or nickel located on the base body, this copper layer or nickel layer being mechanically surface-treated, preferably brushed, and

    - a palladium-nickel layer having a palladium fraction of at least 70 atomic percent on the surface-treated copper layer or nickel layer.
23. Object according to one of Claims 12 to 15, characterized in that it is constructed as follows:

    - a base body of plastic or a base body with plastic surfaces,

    - a copper layer located on the base body,

    - a nickel layer located on the copper layer, this nickel layer being mechanically surface-treated, preferably brushed, and

    - a palladium-nickel layer having a palladium fraction of at least 70 atomic percent on the surface-treated nickel layer.
24. Object according to one of Claims 11 to 23, characterized in that between a surface-treated nickel layer and the nickel-tungsten layer and/or palladium-nickel layer there is a further nickel layer.
25. Object according to Claim 24, characterized in that the surface-treated nickel layer is a so-called sulfamate nickel layer.
26. Object according to Claim 24 or Claim 25, characterized in that the further nickel layer between the surface-treated nickel layer and the nickel-tungsten layer and/or palladium-nickel layer is a so-called sulfamate nickel layer.
27. Object according to one of Claims 11 to 26, characterized by a siloxane and/or polysiloxane top layer over the nickel-tungsten layer and/or palladium-nickel layer.
28. Object according to Claim 27, characterized in that it is constructed as follows:

    - a base body of metal or a base body with metallic surfaces,

    - a copper layer located on the base body,

    - a nickel layer located on the copper layer, preferably a sulfamate nickel layer, which is mechanically surface-treated, preferably brushed,

    - a further nickel layer, preferably a sulfamate nickel layer, located on the surface-treated nickel layer,

    - a nickel-tungsten layer and/or palladium-nickel layer located on this further nickel layer the tungsten fraction of the nickel-tungsten layer being between 30 and 40 atomic percent and the palladium fraction of the palladium-nickel layer being at least 70 atomic percent, and

    - a siloxane/polysiloxane top layer located on the nickel-tungsten layer and/or palladium-nickel layer.
29. Object according to Claim 27, characterized in that it is constructed as follows:

    - a base body of plastic or a base body with plastic surfaces,

    - a copper layer located on the base body,

    - a nickel layer located on the copper layer, preferably a sulfamate nickel layer, which is mechanically surface-treated, preferably brushed,

    - a further nickel layer, preferably a sulfamate nickel layer, located on the surface-treated nickel layer,

    - a nickel-tungsten layer having a tungsten fraction between 30 and 40 atomic percent located on this further nickel layer, and

    - a siloxane/polysiloxane top layer located on the nickel-tungsten layer.
30. Object according to Claim 27, characterized in that it is constructed as follows:

    - a base body of plastic or a base body with plastic surfaces,

    - a copper layer located on the base body,

    - a nickel layer located on the copper layer, preferably a sulfamate nickel layer, which is mechanically surface-treated, preferably brushed,

    - a further nickel layer, preferably a sulfamate nickel layer, located on the surface-treated nickel layer,

    - a palladium-nickel layer having a palladium fraction of at least 70 atomic percent located on this further nickel layer, and

    - a siloxane/polysiloxane top layer located on the palladium-nickel layer.
31. Object according to one of Claims 11 to 30, characterized in that the palladium fraction of the palladium-nickel layer is about 80 atomic percent.
32. Object according to one of Claims 11 to 31, characterized in that the layer thickness of the first metal layer located on the object, particularly a copper layer, is between 10 µm and 60 µm, preferably between 20 µm and 50 µm, particularly between 30 µm and 40 µm.
33. Object according to one of Claims 11 to 32, characterized in that the layer thickness of the nickel layers, preferably the nickel layers located on the surface-treated base body or on a surface-treated layer, is between 5 µm and 25 µm, preferably between 5 µm and 15 µm, particularly between 6 µm and 10 µm.
34. Object according to one of Claims 11 to 33, characterized in that the layer thickness of the nickel-tungsten layers or palladium-nickel layers is between 0.1 µm and 5 µm, preferably between 0.2 µm and 2 µm, particularly between 0.5 µm and 1 µm.
35. Object according to one of Claims 27 to 34, characterized in that the layer thickness of the siloxane/polysiloxane layer is less than 5 µm, preferably less than 1 µm.
36. Object according to Claim 11, characterized in that the metal is brass.
37. Object according to Claim 12, characterized in that the plastic is ABS.
38. Object according to one of Claims 11 to 37, characterized in that it has a so-called high-grade steel appearance.