EP3017095A1

EP3017095A1 - Metal plate

Info

Publication number: EP3017095A1
Application number: EP14749698.8A
Authority: EP
Inventors: Helmut ANDEXLINGER; Paul FENNES; Alfred Gnadenberger; Robert Grill; Herbert WÄHNER; Heinz WALDHÄUSL
Original assignee: Muenze Osterreich AG
Current assignee: Muenze Osterreich AG
Priority date: 2013-07-05
Filing date: 2014-06-25
Publication date: 2016-05-11
Anticipated expiration: 2034-06-25
Also published as: AT514194B1; CA2917345C; JP2017150080A; AT514194A4; CA2917345A1; AU2014286904B2; US20160153110A1; JP6422949B2; WO2015000003A1; JP6423029B2; ZA201600373B; ES2639346T3; JP2016530396A; AU2014286904A1; EP3017095B1; PL3017095T3; US11131035B2; US20180195195A1

Abstract

The invention relates to a metal plate (1) for a coin (2), for a centre pill (3) of a coin (2) or for a ring (4) of a coin (2), where it is suggested that at least one subregion of a surface, on at least one side of the metal plate (1), has a dual-coloured optical element (5) and that said optical element (5) has at least one first region (6) with a first oxide layer (7) of one first colour which is an interference colour, and at least one second region (8) with a second colour, the first colour being different from the second colour.

Description

metal plate

The invention relates to a metal plate according to the preamble of

Claim 1.

Such a metal plate is for a coin, for a part of a coin,

For example, pill or ring provided. Coins are not only used as circulating coins, but also serve as collector coins and / or foams. A foam is, for example, a medal, which is awarded as an award for special achievements, such as sporting nature. Coins, in particular collector coins or foams, must also meet high aesthetic requirements. For example

Medal awards at sporting events an important media event, the medals are often an important identification object of this

Show events. Even collector coins, which are arranged for example behind a showcase, should meet the aesthetic requirements. The appearance of a coin is often formed only by the embossing, ie a three-dimensional relief.

The disadvantage of this is that coins, viewed from a distance, seldom satisfy the aesthetic requirements, or have little distinctive character from a distance, since the characteristic embossing can only be clearly recognized from close up.

The object of the invention is therefore to provide a metal plate of the type mentioned, with which the mentioned disadvantages can be avoided, with which the aesthetic requirements is still guaranteed even at a greater distance, and which is durable and can be produced at the same time with little effort.

This is achieved by the features of claim 1 according to the invention.

This results in the advantage that the coins are well distinguishable and / or identifiable to the observer even from a distance, since a good contrast can be achieved by the two-colored optical element. As a result, for example, lose medals of a sporting event in one

TV broadcasting nothing of their important identity-giving character. Also, in collector coins and / or foams from a distance already given the desired optical effect, which is why it is sufficient to consider these coins in a closed showcase, whereby a for the coin weary or polluting removal from the showcase is no longer necessary.

Furthermore, the two-color optical element allows a large number of further, sophisticated and hitherto impossible coin designs. The oxide layer offers the advantage that its interference color has substantially the same gloss as a polished metal surface, and is not dull or darker like a pigment paint or a finish, and therefore the highest aesthetic

Requirements fulfilled. Furthermore, oxides are chemically slower than metals, whereby the coin does not change the appearance even after many years, since there is no further unwanted oxidation.

Furthermore, the invention relates to a method for producing a two-color optical element of a metal plate according to the preamble of

Claim 10.

The object of this method is to produce a two-color optical element described above in a particularly simple and reliable manner.

This allows coins to be added with little extra effort

conventional coins, be prepared with a beneficial two-colored optical element.

The subclaims relate to further advantageous embodiments of the invention.

It is hereby expressly referred to the wording of the claims, whereby the claims at this point are incorporated by reference into the description and are considered to be reproduced verbatim.

The invention will be described in more detail with reference to the accompanying drawings, in which only preferred embodiments are shown by way of example. Showing:

Fig. 1 shows a preferred embodiment of a coin with a pill

trained metal plate in plan view; FIG. 2 shows the section along the line A in FIG. 1 as the preferred first intermediate stage of a two-color optical element; FIG.

Fig. 3 shows the section of Fig. 2 as a preferred second intermediate stage of

two-color optical element;

Fig. 4 shows the section of Fig. 2 as the first preferred embodiment of a

two-color optical element;

FIG. 5 shows the section from FIG. 2 as the second preferred embodiment of a two-color optical element; FIG. and

Fig. 6 shows the section of Fig. 2 as a third preferred embodiment of a

two-color optical element.

1 to 6 show preferred embodiments of a metal plate 1 for a coin 2, for a pill 3 of a coin 2 or for a ring 4 of a coin 2, wherein at least a portion of a surface on at least one side of the coin

Metal plate 1 has a two-color optical element 5. The metal plate 1 can in this case particularly preferably be formed in one piece and / or homogeneously. Homogeneous in this context means that the metal plate 1 has substantially the same chemical composition over the entire volume, in other words that it is not a bimetallic plate. A coin 2 may be formed in one piece or in several pieces, in particular in two pieces. As pill 3 of a coin 2, in a two-part coin 2, for example one euro coin, preferably the inner part of the coin 2 is designated. The ring 4 of a coin 2 is preferably that part of a two-part coin 2 which preferably surrounds the pill 3 at the edge. The metal plate may be square or round, in particular circular, be formed. A coin 2, or a part of a coin 2, consisting of the metal plate 1 may particularly preferably be designed as a collector coin and / or as a foam, in particular as a medal. The partial area of the surface on at least one side of the metal plate 1 will hereinafter be referred to merely as the partial area. The two-color optical element 5 is arranged on at least one side of the metal plate 1. It can also be provided that a further two-color optical element 5 on the is arranged opposite side. The bichromal optical element 5 may also have more than two colors, and is hereinafter referred to merely as the optical element 5.

The optical element 5 has at least a first region 6 with a first oxide layer 7 with a first color, which first color is an interference color. Particularly preferably, the first oxide layer 7 is at least partially transparent. An interference color in this context is a color which arises when a light beam, in particular white light, is at least partially reflected at both boundary surfaces of a layer of an at least partially transparent material, whereby the difference in the optical path length leads to a constructive and / or destructive interference the individual color components of the reflected light beam comes. Therefore, portions of the spectrum of the reflected light are canceled, depending on the wavelength, whereby the reflected light as

Interference color has the complementary color of the deleted spectral regions. In particular, since an interference color depends on the observation angle, the observation direction for defining the first color can be set as normal to the viewed surface of the metal plate 1.

In particular, it can be provided that the first oxide layer 7 has a first thickness of 20 nm to 2000 nm, in particular 30 nm to 1000 nm, particularly preferably 50 nm to 500 nm. Up to 2000 nm, interference colors are still good

imperceptible. In the range from 50 nm to 500 nm in this case interference colors are particularly pronounced.

Particularly preferably, it can be provided that the first thickness of the first

Oxide layer 7 over the entire surface of the at least one first region 6 is substantially constant.

Furthermore, it can be particularly preferably provided that the first oxide layer 7 is formed as a metal oxide layer.

The optical element 5 furthermore has at least one second area 8 with a second color, the first color being different from the second color. Here, the first area 6 and the second area 8 parts of Be subarea. In particular, it can be provided that the first region 6 is arranged directly adjacent to the second region 8. Furthermore, it can be provided that the subarea is designed to be continuous.

The difference in color can be defined here particularly preferably according to the Lab color space, which is also known under the name CIELAB color space. The Lab color space has three dimensionless axes, the L axis, which represents the brightness and can assume a value between 0 and 100, the a axis which represents the green or red portion of a color and a value between -150 and 100, as well as the b-axis which represents the blue or yellow part of a color and can assume a value between -100 and 150. Through the Lab color space all colors perceivable by humans with different color valences, saturations and brightnesses can be represented as coordinate point, whereby by the choice of the axes equal Euclidean distances of two coordinate points

according to the same color distances.

In this regard, it can be particularly preferably provided that the Euclidean distance of the first color to the second color in the dimensionless Lab color space is at least 5, in particular at least 10, particularly preferably at least 20, dimensionless units. Here, the first color represents a first coordinate point, and the second color represents a second coordinate point of the dimensionless Lab color space.

The first area 6 and / or the second area 8 may be formed, for example, according to a predetermined motif. The choice of motive shown here is absolutely arbitrary and it is clear that the first area 6 and / or the second area 8 can represent any motive. In FIG. 1, the capital letter H is shown as a motif, the H being the second area 8, and the surrounding area being the first area 6. The first region 6 and / or the second region 8 may be formed here as a contiguous region, as shown in FIG. 1, or from a plurality of subregions.

Particularly preferably, it can be provided that the first region 6 is formed as a recess 9 with respect to the second region 8. The optical element 5 can in other words be provided with a height profile. In this case, the optical element 5 may in particular be provided with an embossment, wherein, as shown in FIGS. 2 to 6, the first region 6 is formed as a depression, and the second region 8 as an elevation 13. As a result, the optical element 5 can be produced particularly easily. Furthermore, the motif can be represented congruently by the embossing as well as by the optical element 5. In Fig. 2 to 6, the dimension for better understanding are reproduced very distorted.

Alternatively it can be provided that the second region 8 is formed as a recess 9 with respect to the first region 6.

In particular, it can be provided that the first region 6 is formed as a depression 9 by at least a height of 0.05 mm with respect to the second region 8. Furthermore, it can be provided that the first region 6 and / or the second region 8 have a further embossing, but which have a smaller depth than 0.05 mm. This further embossing can preferably represent fine details of the motif here.

For the production of thin oxide layers, the skilled person many different

Known method.

The first oxide layer 7 can, for example, by means of a physical

Be prepared by vapor deposition method. Such physical

Vapor phase deposition methods, in particular sputtering or sputtering, offer the advantage that a large number of possible oxides can be applied. As a result, the material of the first oxide layer 7 can be selected substantially independently of the material of the metal plate 1.

The first oxide layer 7 may be produced as a further example also by means of a chemical vapor deposition method. Again, many methods for producing uniform oxide layers are known.

The first oxide layer 7 may alternatively be produced by means of a thermal process, for example annealing. In this case, the metal plate 1 is heated in such a way that a first oxide layer 7 of predeterminable thickness is formed. Particularly preferably, it can be provided that the first oxide layer 7 is produced electrochemically. An electrochemical coating process has the advantage of being simple to control and easy to control

can be carried out.

It has proved to be particularly advantageous in this case if the first

Oxide layer 7 is produced by anodic oxidation electrochemically. Anodic oxidation is also known by the term anodic dip coating, ATL for short. For aluminum, anodic oxidation is often referred to as anodization. An oxide layer produced by anodic oxidation advantageously has a particularly uniform layer thickness. Furthermore, the anodic oxidation is easy to control, the coating process being self-stopping at a certain thickness, depending on the coating parameters.

Selbststoppend in this context means that due to the high electrical resistance of the growing oxide layer, it starts at a certain

Layer thickness to no further, or only a negligible,

Layer growth comes. As a result, a final first thickness of the first oxide layer 7 can be specified particularly well by the different coating parameters. Furthermore, in the case of anodic oxidation, a particularly good mechanical toothing of the first oxide layer 7 with the remaining metal plate 1 is provided.

In particular, it can be provided that the first oxide layer 7 comprises an oxide of the material of the metal plate 1. As a result, the first oxide layer 7 is particularly stable, and has a particularly high adhesion to the metal plate 1.

Particularly preferably, it can be provided that the metal plate 1 consists of a metal or a metal alloy of group 4, 5 and / or 6 of the Periodic Table, in particular Ti, Mo, and / or Nb. It has been found that these metals or metal alloys due to the properties of the metals or the

associated metal oxides for the optical element 5 are particularly suitable.

In particular, it can be provided that the metal plate 1 consists of Nb, ie niobium, since Nb has been found to be particularly suitable. The second region 8 can be designed in different ways. For example, it can be provided that the second area 8 is painted, painted and / or printed.

It may preferably be provided that the second region 8 is uncoated, that is, no further coloring layer is artificially applied to the second region. In this case, the second region 8 essentially has the color of the material of the metal plate 1. The second region 8 can also be regarded as uncoated if a natural oxide layer forms by reaction of the bare metal plate 1 with the surrounding atmosphere, for example aluminum oxide on aluminum. An uncoated second area 8 is easy to produce and has a good contrast to the first area 6 with its interference color.

Particularly preferably, it can be provided that the second region 8 has a second oxide layer 10, and in particular the second color is an interference color. This can be, especially from a distance, aesthetically particular

sophisticated optical element 5 are formed, wherein now the second region 8 through the second oxide layer 10 sluggish to the outside

Environmental influences is.

The second oxide layer 10, like the first oxide layer 7, can be produced by different coating methods.

In particular, it can be provided that the second oxide layer 10

electrochemical, in particular by anodic oxidation, is produced. The anodic oxidation here has the additional effect that, if the thickness of the first oxide layer 7 is already self-stopping, there is no further increase of the first thickness, whereby the manufacturing process is particularly easy to control.

It can preferably be provided that the first oxide layer 7 and the second oxide layer 10 are produced by the same coating method, and in particular, except for the thickness, substantially the same as the first oxide layer 7 is formed. In particular, it can be provided that the second oxide layer 10 has a second thickness of 20 nm to 2000 nm, in particular 30 nm to 1000 nm, particularly preferably 50 nm to 500 nm.

Particularly preferably, it can be provided that the second thickness of the second oxide layer 10 is substantially constant over the entire area of the at least one second area 8.

Furthermore, it can be particularly preferably provided that the first oxide layer 7 is thicker than the second oxide layer 10. By the thicker first oxide layer 7, a good contrast of the two interference colors of the first region 6 and the second region 8 can be achieved. In particular, it may be provided here that the first oxide layer 7 is thicker than the second oxide layer 10 by 25 nm, in particular 50 nm, particularly preferably 100 nm.

Alternatively it can be provided that the first oxide layer 7 and the second oxide layer 10 have substantially the same thickness. The different color of the first region 6 and of the second region 8 can in this case take place in that the first region 6 and the second region 8 have a different surface roughness, whereby already differently perceivable interference colors of the first region 6 and the second region 8 can be achieved.

According to the preferred embodiment of a coin in Fig. 1 may be particularly preferably a coin 2 with pill 3 and ring 4, may be provided, wherein at least the pill 3 is formed as a metal plate 1 as advantageously formed above metal plate 1 with an optical element 5. The ring 4 of the coin may in this case particularly preferably be formed from a metal other than the pill 3, in particular silver. The advantage of this is that the ring 4 protects the pill 3, and thus also the optical element 5, from mechanical wear.

Furthermore, the invention comprises methods for producing the bicolor optical element 5 on at least one side of the metal plate 1, in particular a coin 2, a pill 3 of a coin 2 or a ring 4 of a coin 2, comprising an oxide layer generating step and a Surface modification step.

In the oxide film forming step, at least on the one portion of the surface of the metal plate 1, one having an interference color,

Oxide layer 11 is generated.

Furthermore, in a surface modification step, the at least one second region 8 of the subregion of the surface is changed by means of an erosive method in order to achieve different optical properties of a first region 6 of the subregion of the surface. The different optical property can be formed for example as a different color or different dullness.

As a result, a coin 2, a pill 3 of a coin 2 or a ring 4 of a coin 2 with an advantageous optical element 5 can be produced in a particularly simple and reliable manner.

Although coating methods are also known which, for example by means of a mask, specifically coat only the first region 6 with an oxide layer 11, it has proved to be advantageous and simpler to use a whole

To coat part of the surface of the metal plate 1, and to change separately from the oxide layer generating step selectively optical properties of the surface by means of an erosive method, this

Surface modification step before or after the oxide layer generating step can take place. This surface modification step may include partially removing the oxide layer 11, but may also only involve modification of the surface prior to the oxide layer generation step, for example by using the

Surface roughened or polished surface, whereby the color of the oxide layer 11 produced thereon can be changed.

In this case, it can preferably be provided that before

Surface modification step at least a part of the surface of the metal plate 1 roughened, in particular pickled, is. This can improve both the adhesion of the oxide layer 11, as well as a better and

more uniform optical sensation of the oxide layer 11 can be achieved. Furthermore, For example, by selectively polishing and / or abrading the roughened surface, a first region 6 and a second region 8 of the surface can be produced which have different optical properties, in this case gloss or mattness.

To produce an optical element 5 can be provided that the

Surface modification step before the oxide layer forming step

is carried out. In this case, in particular by selective roughening, grinding or polishing of the portion of the still metal surface of the metal plate 1, a first region 6 and a second region 8 with different optical properties can be produced. By the subsequent generation of the oxide layer 11 on the portion of the surface, the oxide layer 11 has substantially the same thickness, but the different structure of the underlying metal surface, the optical effect of the oxide layer 11 can be changed, whereby the first region 6 and the second Area 8 are perceived differently colored. Thereby, a particularly simple method of manufacturing an optical element 5 can be provided because the oxide layer forming step can be formed as a final manufacturing step, and with the generation of only one oxide layer, an interference color-having first region 6 and second region 8 having different colors can be provided.

Alternatively, it may be preferably provided that the oxide layer generating step is performed before the surface modification step, and that at

Surface modification step, the oxide layer 11 is removed in the at least one second region 8, and is left in the at least one first region 6. This also makes it possible to produce an optical element 5 in a particularly simple manner, since first an oxide layer 11 is applied to the at least one subregion of the surface, and then the oxide layer 11 is selectively removed only in the second region 8.

Particularly preferably, it can be provided that before the

Surface modification step the at least a portion of the surface of the metal plate 1 is impressed a height profile. In this case, in particular, the first region 6 as a recess 9, and the second region 8 as elevation 13th be formed. This can be determined by the height profile, in which areas of the at least a portion of the surface of the

Metal plate 1, the ablative process of the surface modification step ablates the surface.

By the height profile, for example, the selective removal of the oxide layer 11 in the second region 8 can be simplified. The embossment of the height profile may be performed before or after the oxide layer forming step. It has proved to be advantageous if the height profile before the

Oxide layer forming step is impressed on the metal plate, since thereby the oxide layer 1 1 is not injured by the embossing process.

Preferably, it can further be provided that after the removal of the oxide layer 1 1 in the second region 8, the metal plate 1 is again embossed. These

Repeated imprinting can in particular include fine details.

When the surface modification step is performed before the oxide layer forming step, by impressing the height profile, the first region 6 and the second region 8 can be lifted apart from each other such that the second region 6 is changed in the ablation process of the surface modification step and the first region 8 is not changed.

It can preferably be provided that as ablative method of

Surface modification step, a mechanical method, in particular a planar grinding and / or polishing, is selected. If the first region 6 is formed as a depression 9, and the second region 8 as an elevation 13, it can be provided, in particular, that the at least one second region 8 is removed mechanically by abrading and / or polishing. This offers the great advantage that the shaping of the first region 6 and of the second region 8 can be effected by the embossing which is usual in any case with a coin 2. As a result, no complicated further method for shaping the first region 6 and the second region 8 is necessary.

The selective removal of the second region 8 can also be done by others

erosive processes take place. For example, by a laser, an ion and / or plasma jet, or by engraving. If the

Oxide layer generating step has already taken place, the oxide layer 11 can also be removed by means of a lithographic process.

In particular, it can be provided that as oxide layer 11 of the

Oxide layer forming step, an oxide of the material of the metal plate 1 is generated. As a result, the oxide layer 11 is particularly resistant, and has a particularly high adhesion to the metal plate 1.

It can preferably be provided that the oxide layer 11 of the

Oxide layer generating step by means of an electrochemical method, in particular by oxidizing the metal plate 1 by anodic oxidation, is generated. By an electrochemical method, the oxide layer 11 can be produced particularly easily. Particularly preferably, it can be provided that the oxide layer 11 is produced by oxidizing the metal plate 1 by anodic oxidation. The advantages of anodic oxidation are, as already described above, the uniform layer thickness and the good

Controllability. Alternatively, the oxide layer 11 also by means of a

physical vapor deposition process, by means of a chemical

Gas phase deposition process or by thermal annealing are generated.

Individual steps of a first preferred embodiment of such

Method are shown in Fig. 2 to Fig. 4.

In Fig. 2, a part of the metal plate 1 is shown, which has been provided with a height profile. In this case, a height profile has already been embossed on the metal plate 1. FIG. 3 shows the location of FIG. 2, wherein the metal plate has been coated with the oxide layer 11 which covers the first area 6 and the second area 8 equally, that is, the oxide layer generating step has already taken place. In FIG. 4, in the surface modification step, the surface of the metal plate 1 was ground flat, as indicated by the dot-dash line, whereby the oxide layer 11 was ablated in the second region 8 and left in the first region 6. FIG. 4 also illustrates a first preferred embodiment of the bichromal optical element 5. In this case, the one left in the first region 6

Oxide layer 11, the first oxide layer 7 of the optical element 5 is. The second region 8 is formed uncoated.

Preferably, when the surface modification step is after the

Oxidschichterzeugungsschritt was carried out, it should be provided that after the

Surface modification step on the at least a portion of the

Surface of the metal plate 1, a further oxide layer 12 is generated. In this case, it can preferably be provided, in particular, that the further oxide layer 12 is produced by the same method as the oxide layer 11. As a result, an optical element can be provided with a first region 6 and a second region 8, wherein both regions 6, 8 have an interference color.

Particularly preferably, it can further be provided that the further oxide layer 12 is produced such that the first region 6 has a first oxide layer 7 with a first thickness, and the second region 8 has a second oxide layer 10 with a second thickness, and that the first Thickness is greater than the second thickness. This results in two different interference colors, which are well distinguishable from each other. By the thicker first oxide layer 7, a good contrast of the two interference colors of the first region 6 and the second region 8 can be achieved.

In particular, it can be provided that the further oxide layer 12 in the second region 8 represents the second oxide layer 10.

FIG. 5 shows a second preferred embodiment of the bichromal optical element 5. In this case, the first oxide layer 7 has a self-stopping first thickness, and the further oxide layer 12 was produced by means of anodic oxidation, which means that there is essentially no further layer growth in the first region 6 came. Therefore, also in the second preferred

Embodiment, the oxide layer 11 left in the first region 6 is the first oxide layer 7 of the optical element 5. The further oxide layer 12 in the second region 8 represents the second oxide layer 10 of the optical element 5 in the second preferred embodiment. In the third preferred embodiment in FIG

Coating process for producing the further oxide layer 12 for a further layer growth in the first region 6. This is the case, for example, when the further oxide layer 12 by means of a physical

Gas phase deposition process was created where it is independent of

Underground to a layer growth comes, or because in an anodic oxidation, the first thickness before the generation of the further oxidation layer was not self-stopping. The first oxide layer 7 in the first region 6 therefore consists of the oxide layer 11 and the further oxide layer 12 in the third preferred embodiment. The further oxide layer 12 in the second region 8 also represents the second oxide layer 10 of the optical element 5 in the third preferred embodiment.

According to a fourth preferred embodiment, not shown, it can preferably be provided that the at least one subregion of the surface of the metal plate 1 is embossed and roughened, in particular pickled. This creates a height profile with a roughened surface. Then the

Surface modification step wherein the second region 8 is ground and polished, whereby the second region 8 is glossy but the first region is still dull. Subsequently, in the oxide layer generation step, the oxide layer 11 is produced on the at least one subregion of the surface, whereby, due to the different surface structure and resulting optical properties of the first region 6 and second region 8

different interference colors are generated.

In order to produce an optical element 5 with more than two colors, can

For example, be provided that a third area, which is in particular a sub-area of the second area 8, is removed. As a result, an optical element 5 having three colors can be manufactured. By further coating with oxides, and / or again abrading area by area, an optical element 5 with any number of colors can be produced.

Claims

PATENT APPLICATIONS

1. Metaüplatte (1) for a coin (2), for a pill (3) of a coin (2) or for a ring (4) of a coin (2), characterized in that at least a portion of a surface on at least one side the metal plate (1) has a bichromal optical element (5), that the optical element (5) has at least a first region (6) with a first oxide layer (7) of a first color, which first color is an interference color, and at least one second area (8) having a second color, wherein the first color is different from the second color.

2. Metal plate (1) according to claim 1, characterized in that the first region (6) as a recess (9) opposite the second region (8) is formed.

3. Metal plate (1) according to claim 1 or 2, characterized in that the first oxide layer (7) is made electrochemically, in particular by anodic oxidation.

4. metal plate (1) according to one of claims 1 to 3, characterized

characterized in that the first oxide layer (7) is an oxide of the material of

Metal plate (1) comprises.

5. metal plate (1) according to one of claims 1 to 4, characterized

characterized in that the metal plate (1) made of a metal or a

Metal alloy of group 4, 5 and / or 6 of the Periodic Table, in particular Ti, Mo, and / or Nb exists.

6. metal plate (1) according to one of claims 1 to 5, characterized

characterized in that the second region (8) has a second oxide layer (10), and in particular the second color is an interference color.

7. metal plate (1) according to claim 6, characterized in that the second oxide layer (10) is made electrochemically, in particular by anodic oxidation.

8. metal plate (1) according to claim 6 or 7, characterized in that the first oxide layer (7) is thicker than the second oxide layer (10).

9. coin (2) with pill (3) and ring (4), characterized in that at least the pill (3) as a metal plate (1) according to claim 1 to 8 is formed.

10. A method for producing a two-color optical element (5) on at least one side of a metal plate (1), in particular a coin (2), a pill (3) of a coin (2) or a ring (4) of a coin (2) , full

- An oxide layer generating step, wherein at least on a portion of a surface of the metal plate (1), an interference color having, oxide layer (11) is generated

- And a surface modification step, wherein at least a second region (8) of the portion of the surface to achieve different optical properties of a first portion (6) of the portion of the surface is changed by means of a removing method.

11. A method according to claim 10, characterized in that before the surface modification step at least a portion of the surface of the metal plate (1) roughened, in particular pickled, is.

12. The method according to claim 10 or 1 1, characterized in that the surface modification step before the oxide layer generation step

is carried out.

A method according to claim 10 or 11, characterized in that the oxide layer generating step is prior to the surface modification step

is performed, and that in the surface modification step, the oxide layer (11) is removed in the at least one second region (8) and is left in the at least one first region (6).

14. The method according to any one of claims 10 to 13, characterized

in that, prior to the surface modification step, a height profile is impressed on the at least one subregion of the surface of the metal plate (1).

15. The method according to any one of claims 10 to 1, characterized

characterized in that as the ablating method of

Surface modification step is a mechanical method, in particular plan grind and / or polish off, is selected.

16. The method according to any one of claims 10 to 15, characterized

in that an oxide of the material of the metal plate (1) is produced as the oxide layer (11) of the oxide layer generating step.

17. The method according to any one of claims 10 to 16, characterized

characterized in that the oxide layer (11) of the oxide layer generating step is produced by an electrochemical method, in particular by oxidizing the metal plate (1) by anodic oxidation.

18. The method according to any one of claims 13 to 17, characterized

in that, after the surface modification step, a further oxide layer (12) is produced on the at least one subregion of the surface of the metal plate (1).

19. The method according to any one of claims 13 to 17, characterized

characterized in that the further oxide layer (12) is produced such that the first region (6) has a first oxide layer (7) with a first thickness, and the second region (8) has a second oxide layer (10) with a second thickness , and that the first thickness is greater than the second thickness.