CH716843B1 - Process for coating metal surfaces in the kitchen area. - Google Patents

Abstract

The invention relates to a method for coating metal surfaces for the kitchen area, in particular surfaces of sinks or worktops. An intermediate layer (2) made of a second material is applied to the surface to be coated made of a first material (1) with a first Vickers hardness, which has at least twice, in particular at least three times the Vickers hardness of the first material (1). A final layer (3) made of a third material is then applied to the intermediate layer (2), which has at least the Vickers hardness of the intermediate layer (2). The coating method according to the invention makes it possible to provide metal surfaces for the kitchen area which have a different color than the base material (1) and have excellent resistance to abrasion and scratching.

Description

The present invention relates to a method for coating metal surfaces for the kitchen area, and a basin and a worktop with a coating produced with the method according to the preambles of the independent claims.

From the prior art it is known to provide sinks and kitchen worktops made of stainless steel for visual purposes with a coloring layer, which is produced by physical vapor deposition. In this way, the visible surfaces of these sinks and worktops are designed, for example, in grey, black, gold or copper.

The problem with these currently known surface coatings, which are essentially selected for design considerations, is that they scratch relatively quickly in practical use and become unsightly, which is the actual purpose of these coatings, to achieve a beautiful visual effect, at least when used as intended usage diametrically opposed.

The object is therefore to provide a technical solution which does not have the aforementioned disadvantages of the prior art or at least partially avoids them.

[0005] This object is achieved by the subject matter of the independent patent claims.

Accordingly, a first aspect of the invention relates to a method for coating metal surfaces for the kitchen area, preferably the surfaces of sinks or worktops that are visible when used as intended.

In a first step, the surface to be coated, e.g. a kitchen sink or kitchen worktop, is made from a first metallic material (base material), e.g. stainless steel, which has a first Vickers hardness.

Then an intermediate layer is applied to the surface to be coated, made of a second material which has at least twice, preferably at least three times the Vickers hardness of the first material.

A final layer made of a third material is applied to the intermediate layer, which has at least the Vickers hardness of the intermediate layer.

The coating method according to the invention makes it possible to provide metal surfaces for the kitchen area which have a different color than the base material and have excellent resistance to abrasion and scratching.

In a first preferred variant of the method, the intermediate layer is applied directly to the surface to be coated and/or the final layer is applied directly to the intermediate layer.

In a second preferred variant of the method, one or more further layers is or are arranged between the surface to be coated and the intermediate layer and/or between the intermediate layer and the final layer.

The intermediate layer is preferably produced by galvanic deposition. Such methods have proven to be particularly suitable for applying the intermediate layer.

The final layer is preferably produced by physical vapor deposition, also referred to as PVD or physical vapor deposition. Methods of this type have proven to be particularly suitable for applying the final layer.

The layer thickness of the final layer is preferably one to two tenths of the layer thickness of the intermediate layer, it being preferred that the layer thickness of the final layer is less than 10 μm, in particular less than 5 μm.

The base material of the surface to be coated (according to the first material) is preferably stainless steel, advantageously austenitic stainless steel, preferably chromium-nickel steel with the specification 1.4301. Such metallic materials have become established in the kitchen area.

The second material from which the intermediate layer according to the claims is formed is preferably chromium or a chromium alloy. Chrome is very hard and can easily be applied as a hard layer on a stainless steel surface.

The third material from which the claimed final layer is formed is preferably a nitride, advantageously a chromium carbonitride (colors "anthracite" and "chrome"), titanium carbonitride (color "copper"), zirconium carbonitride (colors "copper ', 'Brass', 'Bronze', 'Gold' and 'Champagne') or Chrome Zirconium Carbonitride ('Black' colour), or contains such material.

The coating according to the invention is advantageously carried out after the completion of any process steps that form or process the surface to be coated, such as deep drawing, bending, embossing, punching or welding. This makes it possible to prevent the layers applied to the base material from being damaged or flaking off.

A second aspect of the invention relates to a basin, preferably a sink basin, with a coating produced using the method according to the first aspect of the invention.

A third aspect of the invention relates to a basin, preferably a sink basin, with a coating produced using the method according to the first aspect of the invention.

With such products, the advantages of the invention are particularly evident.

[0023] Further preferred embodiments of the invention emerge from the dependent claims and from the following description with reference to the figures. 1 shows a section through the material of a kitchen sink according to the invention.

As can be seen in FIG. 1, which shows a vertical section not to scale through the material of a stainless steel kitchen sink according to the invention, there is an intermediate layer on the top of the approx. 0.8 mm thick base material 1 made of austenitic stainless steel (first material according to the claims). 2 made of chromium with a layer thickness of approx. 10-30 μm, which was produced by galvanic deposition. On top of this intermediate layer is a final layer of chromium zirconium carbonitride with a layer thickness of approx. 3-4 µm, which was produced by physical vapor deposition and gives the surface of the kitchen sink a black appearance.

While in the present application preferred embodiments of the invention are described, it is to be understood that the invention is not limited thereto and may be otherwise embodied within the scope of the following claims.

Claims (12)

1. A method for coating metal surfaces for the kitchen area, in particular surfaces of sinks or worktops, comprising the steps: a) providing the surface to be coated from a first material (1) with a first Vickers hardness; b) application of an intermediate layer (2) to the surface to be coated, made of a second material which has at least twice, in particular at least three times, the Vickers hardness of the first material; c) application of a final layer (3) to the intermediate layer (2) made of a third material which has at least the Vickers hardness of the intermediate layer (2). 2. The method according to claim 1, wherein the intermediate layer (2) is applied directly to the surface to be coated and/or the final layer (3) is applied directly to the intermediate layer (2). 3. The method according to claim 1, wherein one or more further layers are arranged between the surface to be coated and the intermediate layer (2) and/or between the intermediate layer (2) and the final layer (3). 4. The method according to any one of the preceding claims, wherein the intermediate layer (2) is produced by galvanic deposition. 5. The method according to any one of the preceding claims, wherein the final layer (3) is produced by physical vapor deposition. 6. The method according to any one of the preceding claims, wherein the layer thickness of the final layer (3) is one to two tenths of the layer thickness of the intermediate layer (2), and in particular, wherein the layer thickness of the final layer (3) is less than 10 µm, in particular less than 5 µm is. 7. The method according to any one of the preceding claims, wherein the first material (1) is stainless steel, in particular austenitic stainless steel, in particular a chromium-nickel steel with the specification 1.4301. 8. The method according to any one of the preceding claims, wherein the second material (2) is chromium or a chromium alloy. 9. The method according to any one of the preceding claims, wherein the third material (3) is a nitride, in particular a chromium carbonitride, chromium zirconium carbonitride, titanium carbonitride or zirconium carbonitride, or contains such a material. 10. The method according to any one of the preceding claims, wherein the coating takes place after the completion of any process steps forming the surface to be coated. 11. Basin, in particular sink basin, produced with a coating using the method according to any one of the preceding claims. 12. Worktop, in particular kitchen worktop, with a coating produced using the method according to any one of claims 1 to 10.