Object with surface covering layer obtained through electrolytic deposition, electrolytic solution used for said deposition and method for making said object.

Description

FIELD OF APPLICATION OF THE INVENTION

[0001] The present invention concerns the technical field of production of objects with a surface covering.

[0002] In particular, the present invention concerns the production of objects with a surface covering obtained through electrolytic deposition.

[0003] The present invention concerns also the method for making said objects and the electrolytic solution used in said method.

DESCRIPTION OF THE STATE OF THE ART

[0004] Techniques for covering objects, in particular metal objects, are widely used in the most varied sectors.

[0005] We make reference, in particular, to metal objects comprising, for example, accessories for bags, shoes, belts (such as buckles, rings, spring catches, chains, fasteners etc.), parts of glasses (such as sides, bridges, inserts etc.), zip fasteners, buttons, components of watches (such as casings, buckles, bracelet meshes etc.), trinkets (such as bracelets, rings, earrings, pendants etc.), handles (for pieces of furniture, doors, refrigerators etc.), valves, gift items (such as trays, vases and pots, cups, tea pots, milk pots etc.), technical items (such as bushings).

[0006] The objects indicated above are typically produced using brass as base material. The brass that is commonly used and ensures good workability contains a certain percentage of lead. The presence of lead may cause problems related to its toxicity and its release into the environment.

[0007] In order to overcome said drawback, brass alloys without lead have been created that, however, are more expensive and also involve higher processing costs, as they need to be worked with more expensive equipment that wears out more quickly.

[0008] According to the known technique, in order to resolve said problem it has been devised to replace brass with a zama alloy, a material of poorer quality, and to cover said zama alloy with a surface layer in order to improve its aesthetic characteristics and thus make it as similar to a brass object as possible.

[0009] According to a known technique, the surface layer is obtained by means of a galvanic finishing treatment by means of which a layer of an appropriate alloy suited to cover the underlying part in zama alloy is deposited thereon.

[0010] The deposited layer is typically made with alloys containing copper, tin and zinc or copper and zinc, a few microns thick.

[0011] The same covering technique with a galvanic treatment is used also in sectors where base materials of a different type are used, like for example plastic, resins, low-melting alloys etc.

[0012] Also in this case, the surface layer is typically made with alloys containing copper, tin and zinc or copper and zinc, a few microns thick.

[0013] The covering techniques of the known type, however, pose some drawbacks.

[0014] A first drawback of the objects obtained through the above mentioned covering techniques is represented by the appearance of defects as a result of corrosion phenomena, in particular between the surface covering layer and the underlying material, due to transpiration through the surface layer, which can give rise to dangerous electrochemical processes.

[0015] Another drawback arises if the objects obtained by means of the above mentioned covering techniques have to be subjected to welding operations. The covering layers obtained with the known technique do not guarantee the resistance of the weld, and sometimes may even make it impossible to perform the welding operation.

[0016] Another drawback posed by the objects obtained using the techniques of the known type is due to the wearing action to which the external surface of the object is subjected, which causes a deterioration of the aesthetic characteristics of the object and/or the need to restore the ideal conditions with a new covering treatment.

[0017] Thus, the main object of the present invention is to at least partially overcome the drawbacks described above.

[0018] It is a first object of the present invention to provide an object whose surface covering layer has reduced defects compared to the objects belonging to the known art.

[0019] It is another object of the present invention to provide an object having a surface covering layer that can be subjected to welding operations without affecting the mechanical resistance characteristics and/or the aesthetic aspect of the object itself.

[0020] It is another object of the present invention to provide an object having a surface covering layer that maintains its mechanical resistance and/or ornamental characteristics for a longer time compared to the objects of the known type.

[0021] Patent document US 1,970,548 describes a composite article comprising a base material made of ferrous metal and having surface irregularities therein, an electroplated coating composed of 10 - 25 % tin and balance copper bonded to said metal and having a smooth buffed surface free from corresponding surface irregularities, and an overcoating of another metal, preferably chromium.

[0022] In patent document US 1,970,549 is described a process of electroplating bronze. The copper-tin coating is electrodeposited by electrolyzing a solution containing a soluble tin compound and a soluble copper compound, maintaining the alkalinity of said solution within a range from pH 11.7 to 13.8 and maintaining free cyanide in an amount not to exceed 60 grams per liter, preferably within a range between 15 and 25 grams per liter.

[0023] In patent document EP 2 071 057 A2 is described a composition comprising one or more sources of tin ions, one or more sources of copper ions and one or more mercaptans selected from the group consisting of mercaptotriazoles and mercaptotetrazoles.

[0024] Patent document EP 0 163 419 A2 describes a coin comprising a coin-shaped core of mintable metallic material and an electroplated coating completely encasing the core, wherein the electroplated coating has a thickness of 10 to 150 µm, preferably 30 to 50 µm, and contains from 8 to 16 %, preferably 11 to 14 wt.% tin and the balance copper.

[0025] In Patent document US 2006/0068219 A1 is described a coin comprising a metallic core and an electroplated layer of white bronze adhered to the external surfaces of the core and encasing the core.

SUMMARY OF THE PRESENT INVENTION

[0026] The above-mentioned problems are solved by the teaching of independent claim 1. The method for making the object is given in the independent claim 4.

[0027] The present invention is based on the general consideration that it is desirable to make an object having a surface covering layer constituted by an alloy comprising copper and tin whose thickness exceeds 30 micrometres.

[0028] According to a first aspect of the present invention, the subject of the same is, therefore, an object of the type comprising a main body and a surface covering layer suited to at least partially cover said main body, wherein said surface covering layer is constituted by an alloy comprising copper in a percentage varying in weight from 90 to 95 %, tin in a percentage varying in weight from 10 to 5% and impurities in a percentage varying in weight from 0 to 1%, and wherein the thickness of said surface covering layer exceeds 30 micrometres. The main body comprises a conductive material.

[0029] Said main body properly comprises a zama alloy. The surface covering layer is obtained through electrolytic deposition.

[0030] Preferably, the alloy of the deposited layer does not comprise zinc. The subject of the invention is an object being a fashion accessory or a trinket, and belonging to the group comprising: accessories for bags, for shoes, for belts, for example buckles, rings, spring catches, chains, fasteners; parts of glasses, for example sides, bridges, inserts; components of watches, for example casings, buckles, bracelet meshes; trinkets, for example bracelets, rings, earrings, pendants. The subject of the invention is a fashion accessory, like for example said accessories for bags, shoes, belts, for example buckles, rings, spring catches, chains, fasteners etc., or it is a trinket like for example said bracelets, rings, earrings, pendants, etc..

[0031] According to another aspect the subject of the same is an aqueous electrolytic solution used in an electrolytic deposition process for making an object, wherein the solution comprises:

• copper cyanide (CuCN), with values preferably included between 15 and 30 g/l, more preferably included between 24 and 28 g/l, even more preferably equal to 26 g/l;
• potassium stannate (K2SnO3.3H2O), with values preferably included between 10 and 25 g/l, more preferably included between 18 and 22 g/l, even more preferably equal to 20 g/l;
• potassium cyanide (KCN), with values preferably included between 40 and 50 g/l, more preferably included between 43 and 47 g/l, even more preferably equal to 45 g/l;
• free potassium hydroxide (KOH), with values preferably included between 5 and 20 g/l, more preferably included between 8 and 14 g/l, even more preferably equal to 11 g/l.

[0032] Advantageously, the electrolytic solution does not comprise zinc.

[0033] Said electrolytic solution is preferably used to make an object belonging to the group comprising: accessories for bags, for shoes, for belts, for example buckles, rings, spring catches, chains, fasteners; parts of glasses, for example sides, bridges, inserts; components of watches, for example casings, buckles, bracelet meshes; trinkets, for example bracelets, rings, earrings, pendants. Actually, said electrolytic solution is used for making a fashion accessory, like for example said accessories for bags, shoes, belts, for example buckles, rings, spring catches, chains, fasteners etc., or a trinket, like for example said bracelets, rings, earrings, pendants, etc..

[0034] According to a second aspect of the present invention, the subject of the same is a method for making an object of the type comprising a main body and a surface covering layer suited to cover said main body at least partially, said method comprising a stage during which said surface covering layer is obtained through electrolytic deposition in an aqueous electrolytic solution, wherein said electrolytic solution is of the type described above.

[0035] Preferably, during the chemical deposition the pH value of the electrolytic solution is maintained between 12 and 12.5.

[0036] Preferably, during the chemical deposition the temperature of the electrolytic solution is maintained between 58 and 62 °C.

[0037] Preferably, during the chemical deposition the process current is maintained between 0.3 and 2.5 A/dm2.

[0038] Said method is used to make an object belonging to the group comprising: accessories for bags, for shoes, for belts, for example buckles, rings, spring catches, chains, fasteners; parts of glasses, for example sides, bridges, inserts; components of watches, for example casings, buckles, bracelet meshes; trinkets, for example bracelets, rings, earrings, pendants. Actually, said method is used for making a fashion accessory, like for example said accessories for bags, for shoes, for belts, for example buckles, rings, spring catches, chains, fasteners etc., or a trinket, like for example said bracelets, rings, earrings, pendants, etc..

BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Further objects, advantages and characteristics, as well as embodiments of the present invention, are defined in the claims and will be illustrated below by means of the following description with reference to the attached drawings. In particular:

• Figure 1 shows a plan view of an object according to a preferred embodiment of the invention;
• Figure 2 shows a sectional view of a detail of the object of Figure 1 at the level of its external surface;
• Figure 3 shows an apparatus for making the object shown in Figure 1;
• Figure 4 shows an exemplification diagram of some stages of the production process of the object of Figure 1 obtained in the apparatus shown in Figure 3;
• Figure 5 shows a sectional view of a detail of a variant embodiment of the object according to the invention, at the level of its external surface;
• Figure 6 schematically shows one stage of the production process of a variant embodiment of the object according to the invention.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

[0040] Although the present invention is described below with reference to its embodiments illustrated in the drawings, the present invention is not limited to the embodiments described below and illustrated in the drawings. On the contrary, the embodiments described and illustrated herein clarify some aspects of the present invention, the scope of which is defined in the claims.

[0041] The present invention has proved particularly useful when applied to objects comprising a base material constituted by a metallic material, in particular a zama alloy, as is explained in greater detail below. It should however be noted that the present invention is not limited to the production of said objects. On the contrary, the present invention can be conveniently applied in all those cases requiring the production of objects comprising a base material having an external layer made of a non-precious metal, for example objects comprising a base material such as plastic or resin. The base material, furthermore, can be solid or hollow, without distinction.

[0042] A method for making an object according to a preferred embodiment of the invention is described here below with reference to Figures 3 and 4.

[0043] Reference is made, in particular, to the production of a buckle 1 for belts, shown in Figure 1.

[0044] It is evident, however, that the invention can be applied to the production of other objects, in particular metal objects like, for example, accessories for bags, for shoes, for belts (such as buckles, rings, spring catches, chains, fasteners etc.), parts of glasses (such as sides, bridges, inserts etc.), zip fasteners, buttons, components of watches (such as casings, buckles, bracelet meshes etc.), trinkets (such as bracelets, rings, earrings, pendants etc.), handles (for pieces of furniture, doors, refrigerators etc.), valves, gift items (such as trays, vases and pots, cups, tea pots, milk pots etc.), technical items (such as bushings).

[0045] More particularly, the invention is applied to the production of a fashion accessory, like for example said accessories for bags, for shoes, for belts, for example buckles, rings, spring catches, chains, fasteners etc., or of a trinket, like for example said bracelets, rings, earrings, pendants etc..

[0046] The object of the invention 1, meaning the buckle 1, comprises a base material or core 2 and a surface covering layer 3, as shown in the sectioned detail illustrated in Figure 2.

[0047] In the preferred embodiment of the invention, the base material 2 comprises a metallic material, preferably a zama alloy.

[0048] A known process for the production of said objects uses electrolytic deposition technology.

[0049] An apparatus 101 suited to allow the production of an object 1 according to a preferred embodiment of the invention is described with reference to Figure 3.

[0050] The apparatus 101 is substantially constituted by an apparatus for electrolytic deposition.

[0051] The apparatus 101 substantially comprises a tank 102 suited to contain an electrolytic solution, or electrolytic bath, in which the elements to be deposited and intended to make up the surface covering layer 3 of the object 1 of the invention are dissolved, as will be described in greater detail below.

[0052] The tank 102 containing the electrolytic solution is preferably arranged inside a suitable external tank 121.

[0053] The apparatus 101 furthermore comprises a supporting system 103 for the objects 1 to be made. Typically, a plurality of said objects 1 are made at the same time in the apparatus 101.

[0054] In the embodiment illustrated herein, and only by way of example, there are six buckles 1. It is evident that in variant embodiments of the invention a different number of objects having any shape can be made, for example rings, earrings, etc., as already explained.

[0055] The supporting system 103 preferably comprises a centre rotary shaft 104 provided with arms 105 on which the objects 1 to be made are properly arranged.

[0056] The rotary shaft 4 is properly piloted by power means that are not represented herein. A centre control unit of the apparatus 101 is advantageously connected to said power means.

[0057] The centre control unit can be constituted, for example, by a PLC unit installed on a control cabinet.

[0058] The apparatus 101 is also provided with a suitable power supply system suited to create an electric electrodeposition circuit through which a given current I flows.

[0059] In the embodiment shown in the figure, the power supply system comprises a power supply unit electrically connected with a first one of its poles, for example the negative one (cathode), to the supporting system 103 and connected with its second pole, for example the positive one (anode), to annular electrodes 112 arranged inside the tank 121.

[0060] The power supply unit is preferably piloted by the control unit, in such a way as to define the voltage and/or current values that are appropriate for the electric electrodeposition circuit.

[0061] The apparatus 101 will also be provided with further elements, not illustrated herein, suited to allow and guarantee the correct operation of the apparatus 101 itself.

[0062] For example, the apparatus 101 will be preferably provided with an electrolytic solution feeding system and a top-up system suited to compensate for the variations in the components of the electrolytic solution during operation. The apparatus 101 will be preferably provided also with a stirring system suited to mix the electrolytic solution in order to maintain its conditions of homogeneity inside the tank 102 during operation. The apparatus 101 will be preferably provided also with a heating system suited to bring the electrolytic solution to a desired operating temperature T and to maintain it at that temperature. The apparatus 101 will be provided with suitable sensors for measuring operating parameters like, for example, sensors for detecting the level and the temperature of the electrolytic solution.

[0063] The apparatus 101 is preferably provided with a filtering system suited to filter any impurities present in the electrolytic solution.

[0064] A method for making the object 1 using the apparatus 101 of Figure 3 illustrated above is described with reference to Figure 4.

[0065] In an initial stage (block 200), a core made of a conductive material in a suitable shape is prepared, for example, in the case illustrated herein, in the shape of a buckle.

[0066] The core 2 is positioned on the supporting system 103 and immersed in the electrolytic solution previously prepared.

[0067] According to the present invention, the electrolytic solution is constituted by an aqueous solution comprising:

• copper cyanide (CuCN), with values preferably included between 15 and 30 g/l, more preferably included between 24 and 28 g/l, even more preferably equal to 26 g/l;
• potassium stannate (K2SnO3.3H2O), with values preferably included between 10 and 25 g/l, more preferably included between 18 and 22 g/l, even more preferably equal to 20 g/l;
• potassium cyanide (KCN), with values preferably included between 40 and 50 g/l, more preferably included between 43 and 47 g/l, even more preferably equal to 45 g/l;
• free potassium hydroxide (KOH), with values preferably included between 5 and 20 g/l, more preferably included between 8 and 14 g/l, even more preferably equal to 11 g/l.

[0068] According to the present invention, therefore, the electrolytic solution comprises the four elements indicated above, in the corresponding quantities, properly dissolved in water.

[0069] In the successive stage of the method (block 210), the values of the parameters that will determine the successive deposition stage (block 220) are then defined. In particular, the values are defined within which a series of process parameters should be maintained, including:

• the pH value of the electrolytic solution;
• the operating temperature T of the electrolytic solution;
• the process current I;
• the expected duration t1 of the deposition stage.

[0070] The pH value is preferably maintained within the range 12÷12.5.

[0071] The temperature T of the electrolytic solution is preferably maintained within the range 58÷62 °C.

[0072] The process current I is preferably maintained within the range 0.3÷2.5 A/dm2.

[0073] The expected duration t1 of the deposition stage will depend on the desired thickness of the surface covering layer 3, taking into account the deposition speed that derives from the previously set parameter values.

[0074] For example, the process will make it possible to deposit a layer with a thickness of 1 micrometre in a time t1 equal to 100 seconds, with a process current I equal to 2.0 A/dm2, or it will allow the deposit of a layer with a thickness of 1 micrometre in 400 seconds, with a process current I equal to 0.5 A/dm2.

[0075] Once the process parameters (I, pH, T, t1, etc) have been defined,
the deposition stage (block 220) will follow.

[0076] During this stage, thanks to the current I and to the elements that make up the electrolytic solution, a surface covering layer 3 is deposited on the core 2.

[0077] During this stage, inside the tank 102 the electrolytic solution is advantageously kept moving by means of the specific stirrers, not represented herein, while, advantageously, the objects 1 and the supporting element 103 are set rotating through the power means.

[0078] Furthermore, always during said stage, the appropriate checks and corrections will be advantageously made in order to maintain the correct process parameters, like for example the quantity of the various elements of the solution, the pH value, the temperature T, etc.

[0079] At the end of the stage of deposition (block 220) according to the present invention, a surface covering layer 3 will be obtained on the core 2, said layer being constituted by an alloy comprising copper in a percentage varying in weight from 90 to 95 %, tin in a percentage varying in weight from 10 to 5% and impurities in a percentage varying in weight from 0 to 1 %, wherein the thickness of said alloy layer will exceed 30 micrometres.

[0080] In a preferred embodiment of the invention, the object 1 obtained as described above is ready for its final use. In variant embodiments of the invention, however, further external finishing operations can be carried out.

[0081] Usable finishing operations may preferably include mechanical polishing treatments, like for example a vibratory finishing treatment, a tumbling treatment, a rumbling treatment, a lapping treatment, or further galvanic finishing treatments intended to deposit layers a few micrometres thick, using, for example, white bronze, silver, palladium, ruthenium, gold, alloys of these elements, etc.

[0082] Advantageously, the possibility to obtain a thickness of 30 micrometres or more for the surface covering layer 3 makes it possible to obtain a substantially tight covering for the underlying layer 2, actually eliminating the phenomenon of transpiration through the surface layer itself, which instead is present in the known art. Consequently, there is a tendency to avoid creating situations that trigger electrochemical processes that would deteriorate the object 1.

[0083] Always according to the present invention, the possibility to obtain thicknesses of 30 micrometres or more derives from the fact that there is no zinc, in any form, in the electrolytic solution.

[0084] Therefore, the possibility to obtain a thickness of : more than 30 micrometres : makes it possible to obtain a tight surface covering layer that allows the transpiration phenomenon to be avoided, while on the other hand this phenomenon appears in the known art.

[0085] It is to be understood that the surface covering layer may comprise, in addition to copper or tin, low percentages of other elements, or impurities, with values below 1%.

[0086] In this case a thicker layer, in addition to further guaranteeing the tightness provided by the surface covering layer 3, makes it possible to carry out welding operations at the level of the surface covering layer 3. Such a thickness value, considerably higher than the values of a few microns obtainable with the known technique, allows the welded object to maintain the desired mechanical resistance characteristics.

[0087] The object 1, therefore, can be welded to other metallic elements, or other elements of the same type obtained according to the process of the present invention.

[0088] Again, the possibility to obtain thicknesses of more than 30 microns derives from the fact that there is no zinc in the electrolytic solution, as already explained above. The presence of zinc, in this case, would cause the generation of cracks and would damage the surface layer 3 itself.

[0089] Again, the possibility to make a thicker surface layer increases the useful life of the object in terms of surface wear.

[0090] A variant embodiment of an object 51 produced according to the present invention is described with reference to Figures 5 and 6.

[0091] The object 51 described differs from the previously described object due to the fact that the core 52 comprises a layer of non-metallic material 54, for example represented in Figure 6. It is known, in fact, that in order to deposit a material on an object through electrolysis, said object must have electric conductivity properties.

[0092] The metallization stage makes it possible to create the layer of conductive material 55 on top of the layer of non-metallic material 54 so as to obtain the core 52 to be immersed in the electrolytic solution. The metallization process is preferably carried out by depositing a conductive layer through spraying, as schematically shown exactly in Figure 6, preferably a layer of a material containing microparticles in silver or copper or brass.

[0093] The core 52 obtained in this way, that is, the core 52 provided with the conductive layer 55, is then subjected to the successive deposition stages, according to the description provided above, through the use of the apparatus 101.

[0094] The object 51 obtained in this way will therefore have the same characteristics and offer the same advantages described above with reference to the first embodiment.

[0095] In further embodiments of the invention, not illustrated herein, further intermediate layers can be present between the underlying core and the surface covering layer. For example, according to the invention, it is possible to make a layer of alkaline copper or acid copper, in particular when the core is constituted by a zinc alloy.

[0096] Said intermediate layers make it possible to improve the mechanical and/or ornamental characteristics of the object as a whole.

[0097] It has thus been shown that the present invention allows the set objects to be achieved. In particular, it makes it possible to produce an object provided with a surface covering layer having reduced defects compared to the objects belonging to the known art.

[0098] While the present invention has been described with reference to the particular embodiments described and shown in the figures, it should be noted that the present invention is not limited to the specific embodiments illustrated and described herein; on the contrary, further variants of the embodiments described herein fall within the scope of the present invention, which is defined in the claims.

Claims

1. A fashion accessory or a trinket (1; 51) of the type comprising a base material (2) and a surface covering layer (3) obtained through electrolytic deposition, suited to at least partially cover said base material (2), characterized in that said base material (2) comprises a zama alloy and said surface covering layer (3) is constituted by an alloy comprising copper in a percentage varying in weight from 90 to 95%, tin in a percentage varying in weight from 10 to 5%and impurities in a percentage varying in weight from 0 to 1%, and in that the thickness of said surface covering layer (3) exceeds 30 micrometres.

2. Fashion accessory or a trinket (1; 51) according to any of the preceding claims, characterized in that said alloy does not comprise zinc.

3. Fashion accessory or a trinket (1; 51) according to any of the preceding claims, characterized in that it is an object (1; 51) belonging to the group comprising: accessories for bags, for shoes, for belts, for example buckles, rings, spring catches, chains, fasteners; parts of glasses, for example sides, bridges, inserts; components of watches, for example casings, buckles, bracelet meshes; trinkets, for example bracelets, rings, earrings, pendants;

4. Method for making an fashion accessory or a trinket (1; 51) according to one of claims 1 to 3, said method comprising a stage for making said surface covering layer (3) through electrolytic deposition in an aqueous electrolytic solution, characterized in that said electrolytic solution is comprising

- copper cyanide (CuCN), with values included between 15 and 30 g/l, more preferably included between 24 and 28 g/l, even more preferably equal to 26 g/l;

- potassium stannate (K2SnO3 · 3H2O), with values included between 10 and 25 g/l, more preferably included between 18 and 22 g/l, even more preferably equal to 20 g/l;

- potassium cyanide (KCN), with values included between 40 and 50 g/l, more preferably included between 43 and 47 g/l, even more preferably equal to 45 g/l;

- free potassium hydroxide (KOH), with values included between 5 and 20 g/l, more preferably included between 8 and 14 g/l, even more preferably equal to 11 g/l.

5. Method according to claim 4, characterized in that said electrolytic solution does not comprise zinc.

6. Method according to claim 5, characterized in that during said chemical deposition the pH value of said electrolytic solution is maintained between 12 and 12.5.

7. Method according to claim 5 or 6, characterized in that during said chemical deposition the temperature of said electrolytic solution is maintained between 58° and 62°C.

8. Method according to any of the claims from 5 to 7, characterized in that during said chemical deposition the process current is maintained between 0.3 and 2.5 A/dm2.

Ansprüche

1. Ein Modeaccessoire oder Modeschmuck (1, 51) des Typs, der ein Grundmaterial (2) und eine durch elektrolytische Ablagerung gebildete Oberflächendeckschicht (3) umfasst, welche dazu geeignet ist, das besagte Grundmaterial (2) wenigstens teilweise zu bedecken, dadurch gekennzeichnet, dass das besagte Grundmaterial (2) eine Zamak-Legierung umfasst, und die besagte Oberflächendeckschicht (3) aus einer Legierung besteht, die einen zwischen 90 und 95 % variierenden Gewichtsanteil Kupfer, einen zwischen 10 bis 5 % variierenden Gewichtsanteil Zinn, und einen zwischen 0 bis 1 % variierenden Gewichtsanteil Verunreinigungen enthält, und dadurch, dass die Dicke der besagten Oberflächendeckschicht (3) mehr als 30 Mikrometer beträgt.

2. Modeaccessoire oder Modeschmuck (1, 51) gemäß eines jeden der vorstehenden Patentansprüche, dadurch gekennzeichnet, dass die besagte Legierung kein Zink enthält.

3. Modeaccessoire oder Modeschmuck (1, 51) gemäß eines jeden der vorstehenden Patentansprüche, dadurch gekennzeichnet, dass es ein Objekt (1; 51) ist, welches zu der Gruppe gehört, die Folgendes umfasst: Accessoires für Taschen, für Schuhe, für Gürtel, zum Beispiel Schnallen, Ringe, Karabinerhaken, Ketten, Verschlüsse; Teile von Brillen wie zum Beispiel Bügel, Stege, Einsätze; Komponenten von Armbanduhren wie zum Beispiel Gehäuse, Schnallen, Armbandmaschen; Modeschmuck wie zum Beispiel Armreifen, Ringe, Ohrringe, Anhänger.

4. Verfahren zur Herstellung eines Modeaccessoires oder Modeschmucks (1, 51) gemäß eines der Patentansprüche von 1 bis 3, wobei das besagte Verfahren eine Phase der Ausführung der besagten Oberflächendeckschicht (3) durch elektrolytische Ablagerung in wässriger Elektrolytlösung umfasst, dadurch gekennzeichnet, dass die besagte Elektrolytlösung Folgendes umfasst:

- Kupfercyanid (CuCN) mit Werten zwischen 15 und 30 g/l, besonders bevorzugt zwischen 24 und 28 g/l, noch bevorzugter gleich 26 g/l;

- Kaliumstannat (K2Sn03 · 3H20) mit Werten zwischen 10 und 25 g/l, besonders bevorzugt zwischen 18 und 22 g/l, noch bevorzugter gleich 20 g/l;

- Kaliumcyanid (KCN) mit Werten zwischen 40 und 50 g/l, besonders bevorzugt zwischen 43 und 47 g/l, noch bevorzugter gleich 45 g/l;

- freies Kaliumhydroxid (KOH) mit Werten zwischen 5 und 20 g/l, besonders bevorzugt zwischen 8 und 14 g/l, noch bevorzugter gleich 11 g/l.

5. Verfahren gemäß Patentanspruch 4, dadurch gekennzeichnet, dass die besagte Elektrolytlösung kein Zink enthält.

6. Verfahren gemäß Patentanspruch 5, dadurch gekennzeichnet, dass während der besagten chemischen Ablagerung der pH-Wert der besagten Elektrolytlösung bei 12 bis 12,5 gehalten wird.

7. Verfahren gemäß Patentanspruch 5 oder 6, dadurch gekennzeichnet, dass während der besagten chemischen Ablagerung die Temperatur der besagten Elektrolytlösung bei 58° bis 62°C gehalten wird.

8. Verfahren gemäß eines jeden der Patentansprüche von 5 bis 7, dadurch gekennzeichnet, dass während der besagten chemischen Ablagerung der Verfahrensstrom zwischen 0,3 und 2,5 A/dm2 gehalten wird.

Revendications

1. Accessoire de mode ou bijou (1 ; 51) du type comprenant un matériau de base (2) et une couche superficielle de revêtement (3) obtenue par dépôt électrolytique, apte à recouvrir au moins partiellement ledit matériau de base (2), caractérisé en ce que ledit matériau de base (2) comprend un alliage de zamak et ladite couche superficielle de revêtement (3) se compose d'un alliage comprenant du cuivre dans un pourcentage variable en poids de 90 à 95%, étain dans un pourcentage en poids de 10 à 5% et des impuretés dans un pourcentage variable en poids de 0 à 1%, et en ce que ladite couche superficielle de revêtement (3) présente une épaisseur supérieure à 30 micromètres.

2. Accessoire de mode ou bijou (1 ; 51) selon l'une quelconque des revendications précédentes, caractérisé en ce que ledit alliage ne comprend pas de zinc.

3. Accessoire de mode ou bijou (1 ; 51) selon l'une quelconque des revendications précédentes, caractérisé en ce qu'il est un objet (1 ; 51) appartenant au groupe comprenant : accessoires pour sacs, pour chaussures, pour ceintures, par exemple boucles, anneaux, mousquetons, chaînes, fermetures ; parties de lunettes, par exemple branches, ponts, inserts ; composants de montres, par exemple boîtiers, boucles, mailles de bracelet ; bibelots, par exemple bracelets, anneaux, boucles d'oreilles, pendentifs.

4. Méthode pour la réalisation d'un accessoire de mode ou bijou (1 ; 51) selon l'une des revendications de 1 à 3, ladite méthode comprenant une phase de réalisation de ladite couche superficielle de revêtement (3) par dépôt électrolytique dans une solution électrolytique aqueuse, caractérisée en ce que ladite solution électrolytique comprend :

- cyanure de cuivre (CuCN) avec des valeurs comprises entre 15 et 30 g/l, plus préférablement comprises entre 24 et 28 g/l, encore plus préférablement égales à 26 g/l ;

- stannate de potassium (K2SnO3·3H2O) avec des valeurs comprises entre 10 et 25 g/l, plus préférablement comprises entre 18 et 22 g/l, encore plus préférablement égales à 20 g/l ;

- cyanure de potassium (KCN) avec des valeurs comprises entre 40 et 50 g/l, plus préférablement comprises entre 43 et 47 g/l, encore plus préférablement égales à 45 g/l ;

- hydroxyde de potassium libre (KOH) avec des valeurs comprises entre 5 et 20 g/l, plus préférablement entre 8 et 14 g/l, encore plus préférablement égales à 11 g/l.

5. Méthode selon la revendication 4, caractérisée en ce que ladite solution électrolytique comprend du zinc.

6. Méthode selon la revendication 5, caractérisée en ce que durant ledit dépôt chimique la valeur du pH de ladite solution électrolytique est maintenue entre 12 et 12,5.

7. Méthode selon la revendication 5 ou 6, caractérisée en ce que durant ledit dépôt chimique la température de ladite solution électrolytique est maintenue entre 58° et 62° C.

8. Méthode selon l'une quelconque des revendications de 5 à 7, caractérisée en ce que durant ledit dépôt chimique le courant de processus est maintenu entre 0,3 et 2,5 A/dm2.

Drawing