Coated metallic article of daily use

Abstract

Article of daily use which has at least one metallic component or is formed by a metallic component which has a partially or fully formed cover layer made of a plastic, wherein the metallic component has a coating by means of an intermediate layer made of a tin-nickel alloy (SnNi) which is galvanically applied to the surface of a base body of the metallic component, so that the intermediate layer is arranged between the base body and the cover layer.

Description

[0001] The invention relates to a consumer article, in particular for decorative or representative purposes, which has at least one metallic component or is formed by a metallic component which has a cover layer made of a plastic.

[0002] The articles of daily use within the meaning of the invention are intended in particular for valuable, decorative and representative use, such as coins, medals, seals, tokens, accessories, decorative elements, jewelry, writing utensils, trophies or parts thereof.

[0003] In the manufacture of the aforementioned consumer goods, silver (Ag), non-ferrous metals such as copper (Cu), or non-ferrous metal alloys such as copper-nickel (CuNi) are often used as the material for the base body, which forms the basis of the metallic component of the consumer goods.

[0004] The materials mentioned are proven materials that are well suited for the production of valuable consumer goods, particularly for the mechanical production processes of coins.

[0005] The surface of the metallic component is coated directly with a top layer in a known manner in order to achieve, for example, corrosion protection and / or a decorative coloring of the metallic article of daily use.

[0006] For the plastic covering layer of the metallic component, a synthetic resin is used, which consists of or contains, for example, acrylic or epoxy resin and which is hardened by a reaction with a curing agent.

[0007] The synthetic resin can be applied to the surface of the base body of the metallic component as a varnish, a thinner ink, or as a film using pad, screen, or digital printing. A subsequent curing process, e.g., thermal or UV radiation, forms the plastic top layer on the surface of the base body.

[0008] The covering layer of the metallic component can in particular be an application of a colored synthetic resin varnish or a colored synthetic resin ink.

[0009] To enhance the decorative value of metallic everyday objects, for example, only parts of the metallic component are coated with colored paints or inks to provide them with colorful accents.

[0010] The above-mentioned articles of daily use may be embossed before coating in order to achieve a visibly profiled surface (relief surface) for further decorative or marking purposes.

[0011] However, with this known manufacturing technique there is a risk that the base body to be coated will react with the surrounding atmospheric oxygen during the processing and, for example, in the case of the base body made of copper-nickel alloy (CuNi), form a nickel oxide layer (e.g. NiO, Ni2O3), or, on the other hand, react with sulfur compounds present in the air and, for example, in the case of the base body made of silver (Ag), form a silver sulfide layer (Ag2S) on the surface.

[0012] These grown metal oxide compounds, on the one hand, cause an unwanted color change of the metal surface of the base body (tarnishing behavior) and, on the other hand, cause insufficient layer adhesion of the applied top layer, which results in insufficient resistance to mechanical stresses that occur, for example, due to mechanical effects in subsequent processing steps (automated handling / packaging processes) and / or due to daily use in handling the article.

[0013] The result is unwanted, premature abrasive wear of the surface of the article of daily use, resulting in an adverse appearance and feel of the article of daily use.

[0014] Based on this, the invention is based on the object of developing a consumer article of the type mentioned at the beginning with an improved quality of the surface with regard to the durability of the coating and thus a consumer article with permanent preservation of the appearance and feel.

[0015] In particular, the aim is to prevent tarnishing of the metal surface of the base body and chipping of the coating.

[0016] The object is achieved according to the invention by a coating arrangement of the metallic article of daily use having the features of claim 1.

[0017] According to the invention, the metallic component has an intermediate layer made of a tin-nickel alloy (SnNi layer) galvanically applied to the surface of the base body of the metallic component, so that the intermediate layer is arranged between the base body and the cover layer.

[0018] This intermediate layer is in direct contact with the metallic base body on the one hand and with the plastic cover layer on the other.

[0019] Coating tests on decorative objects of the type mentioned above have shown that an SnNi layer applied galvanically to the metallic base body before coating with the top layer forms a very good adhesion promoter between the base body and the top layer.

[0020] Due to the low electrochemical reactivity of the galvanic SnNi layer, oxidation of the base body and thus tarnishing of the metallic component can be effectively prevented.

[0021] In particular, due to the surface of the metallic base body being free of oxide layer, the plastic cover layer can establish a good electrostatic bond or adhesion on the SnNi-coated surface of the metallic base body.

[0022] This can significantly reduce the tendency for the applied top layer to partially chip off, e.g. on coins or the like, both during automated packaging (rolling) and in daily use.

[0023] Since the galvanic coating of the base body effectively prevents the formation of new oxide layers, the uncovered part of the metallic component remains visually appealing even if only a partially formed covering layer is used, for example for accents.

[0024] According to an advantageous embodiment, the base body comprises silver (Ag), non-ferrous metal, such as copper (Cu) or a non-ferrous metal alloy, such as copper-nickel alloy (CuNi), or consists of these materials.

[0025] Because of their durability, these materials are particularly suitable as basic materials for the production and use of valuable, decorative and representative everyday objects, in particular for the production and use of coins, which are particularly frequently encountered valuable objects.

[0026] According to a further advantageous embodiment, the surface of the base body of the metallic component is electrolytically, preferably anodically, degreased.

[0027] By electrolytic, preferably anodic, degreasing of the base body immediately prior to the galvanic coating, its surface can be effectively freed from any oxide layers that may have formed during the manufacturing process.

[0028] During anodic degreasing, a so-called redox reaction occurs, in which metal oxides formed on the surface of the substrate are broken down by the release of oxygen. The surface of the substrate can also be degreased cathodically, whereby any grease present on the surface of the substrate can be dissolved by the hydrogen formed.

[0029] A preferred embodiment of the invention provides that the surface of the base body of the metallic component has a galvanically applied underlayer which contains nickel (Ni) or consists of nickel (Ni), so that the underlayer is arranged between the base body and the intermediate layer.

[0030] This further improves the adhesion between the SnNi layer and the substrate due to the material affinity between the nickel in the base layer and the nickel in the intermediate layer. It can also positively influence the embossability of the electroplated substrate.

[0031] According to a further preferred embodiment, the tin-nickel alloy (SnNi) of the intermediate layer has a proportion of 65% tin and 35% nickel (Ni).

[0032] It has been shown that this composition of the intermediate layer leads to very good results in terms of plastic deformability and adhesion strength of the coating, which has a positive influence on the wear behavior during subsequent processing of the article of daily use, such as a possible packaging process or embossing process.

[0033] If the intermediate layer has a thickness of less than 2 µm, preferably 1 µm, this results in particularly high ductility. In other words, particularly good plastic deformability with good adhesive strength is achieved.

[0034] If the underlayer has a layer thickness of less than 1µm, preferably 0.5µm, this further improves the achievement of particularly high ductility.

[0035] According to a further preferred embodiment, the galvanically coated, metallic component has an at least partially profiled surface as a result of a stamping process.

[0036] This gives the article of daily use a special visual and tactile enhancement. Such an embossing process is used, for example, for coins (coin minting), which is preferably carried out on a semi-finished product (e.g., raw blanks) of the metallic component that exhibits the intermediate layer (SnNi layer), since the SnNi layer according to the invention also withstands mechanical deformations, such as those caused by the embossing process, while maintaining good adhesion to the base body or the galvanic underlayer.

[0037] In a particularly enhancing embodiment, the cover layer covers the area of ​​the profiled surface of the metallic component, e.g. for colored accentuation, without fear of the cover layer flaking off, even if the raised surface of the metallic component is exposed to mechanical wear in daily use.

[0038] With the coating according to the invention, there is also no risk that if the cover layer is only partially applied, the remaining area of ​​the metallic component not covered by the cover layer will show adverse tarnishing behavior.

[0039] The article of daily use according to the invention is explained in more detail below using an exemplary embodiment. The accompanying drawings are schematic representations showing Fig. 1 a sectional view of a consumer article (as an example a minted coin) according to the state of the art (SdT), Fig. 2 a sectional view of a semi-finished coin (round blank) coated according to the invention and Fig. 3 a sectional view of a coin coated and minted according to the invention.

[0040] The drawings explained below form a part of the invention. The drawings show, by way of illustration, specific embodiments in which the invention may be practiced.

[0041] It is understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention.

[0042] It is also understood that the features of the various exemplary embodiments described herein may be combined with one another, unless specifically stated otherwise. The following detailed description is therefore not to be construed in a limiting sense. The scope of the present invention is defined by the appended claims.

[0043] In the figures, identical or similar elements are provided with identical reference numerals where appropriate.

[0044] Fig. 1 illustrates the current situation of state-of-the-art minted coins in use.

[0045] The coin shown schematically and enlarged consists of a metallic base body 1, such as a copper-nickel alloy (CuNi), which has a partially profiled surface as a result of a minting process. The minted coin has a circumferential edge on both sides and a central embossed motif on one side.

[0046] In the area of ​​the central motif, the coin is printed with a cover layer 4 made of acrylic, which was hardened with UV light.

[0047] Before the cover layer 4 could be applied to the profiled base body 1 during the coin processing process, a nickel oxide layer 5 had formed over the entire surface of the base body 1 of the coin, in which Fig. 1 indicated as a grey line.

[0048] The printed cover layer 4 cannot build up sufficient layer adhesion to the metallic base body 1 due to the existing oxide layer 5 and does not have sufficient adhesive strength against abrasive, shearing stress caused by rubbing, impact, scratching, such as occurs in daily use or during automatic packaging, so that as a result, flaking 6 of the cover layer 4 appears in the area of ​​the coated embossed motif, while the remaining, non-coated area of ​​the coin has an undesirable tarnish color due to the oxide layer 5.

[0049] In Fig. Figure 2 shows a cross-section of a semi-finished coin (round blank) coated according to the invention. The semi-finished product represents the manufacturing state of the coin before the minting process and the final coating and comprises a base body 1 made of a copper-nickel alloy (CuNi), a base layer 2 made of nickel (Ni) electroplated onto the base body 1, and an intermediate layer 3 made of a tin-nickel alloy (SnNi) electroplated thereon. The base layer 2 has a layer thickness of approximately 0.5 µm, while the intermediate layer 3 has a layer thickness of approximately 1 µm. The layer thicknesses are shown schematically enlarged for illustrative purposes.

[0050] The sublayer 2 and the intermediate layer 3 in combination provide very good ductility and adhesion base for the further manufacturing processes of the semi-finished product into the finished consumer article.

[0051] In addition, no oxide layer 5 can form on the surface of the semi-finished product in the following production steps.

[0052] By means of electrolytic degreasing of the base body 1 before the application of the underlayer 2, the formation of an oxide layer 5 on the surface of the base body 1 is also prevented in this first manufacturing step, so that the adhesion of the underlayer 2 to the base body 1 is also improved.

[0053] Fig. 3 shows the cross-section of the coin in its finished state. Fig. The semi-finished product shown in Figure 2 has undergone a minting process which has produced a circumferential edge on both sides of the coin and a central minting motif on one side of the coin.

[0054] The galvanic underlayer 2 made of nickel (Ni) and the intermediate layer 3 made of tin-nickel alloy (SnNi) applied to the semi-finished product have each survived the stamping process undamaged and protect the base body 1 with the homogeneously closed layer system against oxidative attack.

[0055] The subsequently printed and hardened acrylic cover layer 4 in the area of ​​the central embossed motif has a strong electrostatic bond to the galvanic layers and consequently to the base body and forms a particularly durable, closed protective layer on the embossed motif over the entire printing area. List of reference symbols 1 base body 2 galvanic underlayer 3 galvanic intermediate layer 4 Top layer 5 Oxide layer 6 Flaking of the top layer

Claims

[1] Consumer article comprising or consisting of at least one metallic component which has a partially or fully formed cover layer of a plastic, wherein the metallic component has a coating by an intermediate layer of a tin-nickel alloy (SnNi) electroplated on the surface of a base body of the metallic component, such that the intermediate layer is arranged between the base body and the cover layer. [2] Consumer item, according to claim 1, characterized by that the base material contains or consists of silver, non-ferrous metal or an alloy thereof. [3] Consumer goods, according to claim 1 or 2, characterized by, that the surface of the base body of the metallic component has an electroplated sublayer containing or consisting of nickel (Ni), such that the sublayer is arranged between the base body and the intermediate layer. [4] Consumer goods according to any one of claims 1 to 3, characterized by , that the tin-nickel alloy (SnNi) of the intermediate layer has a proportion of 65% tin and 35% nickel (Ni). [5] Consumer goods according to any one of claims 1 to 4, characterized by that the intermediate layer has a layer thickness of less than 2µm, preferably 1µm. [6] Consumer goods according to any one of claims 1 to 5, characterized by that the sublayer has a layer thickness of less than 1µm, preferably 0.5µm. [7] Consumer goods according to any one of claims 1 to 6, characterized bythat the surface of the base body of the metallic component is electrolytically, preferably anodically, degreased. [8] Consumer goods according to any one of claims 1 to 7, characterized by , that the electroplated metallic component has a surface that is at least partially profiled due to an embossing process. [9] Consumer goods, according to claim 8, characterized by , that the top layer covers the profiled surface of the electroplated metallic component.

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