METHOD OF DECORATING PVD COATED SURFACES AND DECORATED SURFACES OBTAINED
20230071739 · 2023-03-09
Inventors
Cpc classification
C25D11/024
CHEMISTRY; METALLURGY
C25F7/00
CHEMISTRY; METALLURGY
International classification
Abstract
A method for decorating metallic or non-metallic surfaces treated with Physical Void Deposition, PVD, comprising: an electrochemical activation action of the decoration by means of an electrical circuit with electrodes in electrical contact and for at least one thereof with the mediation of an electrolytic solution towards a surface being treated; an electrically conductive surface facing one of said electrodes to form said surface being treated; at least one masking resistant to the electrochemical activation action of the decoration and interposed between the facing electrode and the surface being treated; and has the electrochemical action of activating the decoration of the treated surface occurs by electrochemical oxidation of the metallic oxide layer normally present on the electrically conductive surface whether it is placed below the PVD coating layer, i.e., performed before such PVD coating, or such electrochemical oxidation action is performed above said vacuum metallic coating, electrically conductive PVD layer; the electrochemical oxidation acts with the surface of the treated metal, its natural oxide, or the PVD coating itself, i.e., on the oxides, carbides, nitrides forming it, without any removal of metallic material but with the aesthetic modification of the treated surface in the shape determined by the aforesaid masking.
Claims
1. A method for decorating metallic or non-metallic surfaces treated with Physical Void Deposition, PVD, comprising: an electrochemical activation action of the decoration by means of an electrical circuit with electrodes in electrical contact and for at least one thereof with the mediation of an electrolytic solution towards a surface being treated; an electrically conductive surface facing one of said electrodes forming said surface being treated; at least one masking resistant to the electrochemical activation action of the decoration and interposed between the facing electrode and the surface being treated; characterized in that the electrochemical activation action of the decoration of the treated surface occurs by electrochemical oxidation of the metallic oxide layer normally present on the electrically conductive surface, whether it is placed below the PVD coating layer, i.e., carried out before such PVD coating, or such electrochemical oxidation action is carried out on said vacuum metallic coating, electrically conductive PVD layer; the electrochemical oxidation acts with the treated metallic surface, its natural oxide, or the PVD coating itself, i.e., on the oxides, carbides, nitrides forming it, without any removal of metallic material but with the aesthetic modification of the treated surface in the shape determined by the aforesaid masking.
2. A method for decorating surfaces according to claim 1, wherein the decoration with a graphic shape on the treated electrically conductive surface is performed by electrochemical oxidation and subsequently said decorated surface is covered with decorative PVD coating.
3. A method for decorating surfaces according to claim 2, wherein the electrically conductive surface treated with the decoration and coated with a PVD coating is in turn treated with a decoration by means of electrochemical oxidation directly on the decorative PVD coating layer, to form a repeated graphic shape combined with the original graphic shape.
4. A method for decorating surfaces, according to claim 3, wherein the decoration made on the PVD coating has a graphic shape associated with the first decoration creation, graphic shape, previously made on the electrically conductive surface below the decorative PVD coating and has a conformation such as to make a three-dimensional effect for the user of the final decoration.
5. A method for decorating surfaces, according to claim 1, wherein the treated surface in non-conductive material and continuous conformation with a metallic vacuum coating, decorative or even functional/technical PVD coating, electric conductor on which the decoration is made with a graphic shape obtained directly by electrochemical oxidation with masking on such PVD coating.
6. A method for decorating surfaces, according to claim 1, wherein the treated surface in conductive material and continuous conformation with a metallic vacuum coating applied, decorative or even functional/technical PVD coating, electric conductor on which the decoration is made with a graphic shape obtained directly by electrochemical oxidation with masking on such PVD coating.
7. A method for decorating surfaces, according to claim 1, wherein the treated surface in conductive material and non-continuous conformation, such as metallic mesh or fabric, with a metallic vacuum coating, decorative or even functional/technical PVD coating, electric conductor on which the decoration is made with a graphic shape obtained directly by electrochemical oxidation with masking on such PVD coating.
8. A method for decorating surfaces according to claim 1, wherein the electrochemical oxidation action applied on the PVD coating generates shimmering and iridescent oxides in the decoration obtained.
9. A method for decorating surfaces according to claim 1, wherein the electrochemical oxidation action applied to the electrically conductive surface being treated occurs at an electrical voltage between 6 and 14 Volts, in alternating current AC, with a current density of 100 Amps per square metre, for a treatment time of 20 seconds per square metre at each decoration step possibly repeated.
10. A method for decorating surfaces, according to claim 9, wherein the electrochemical oxidation action applied to the electrically conductive surface being repeatedly treated, in order to achieve specific optical and/or iridescent colours or effects, occurs with the decoration action of four to eight repeated steps; the treatment time is thus 2 minutes per square metre of conductive surface being decorated.
11. Decorated surfaces of electrically conductive materials with continuous or non-continuous conformation with the decoration method according to claim 1, wherein the decoration has shimmering and iridescent colours.
12. Decorated surfaces of electrically conductive materials with continuous or non-continuous conformation with the decoration method according to claim 4, wherein the decoration has shimmering and iridescent colours.
13. Decorated surfaces of electrically conductive materials with continuous or non-continuous conformation with the decoration method according to claim 1, wherein with the application of the decorative metallic PVD vacuum coating, they have high surface hardness, high corrosion resistance, resistance to salt spray without surface alteration, scratch and abrasion resistance, resistant to solvents, acids or alkalis and household anti-limescale products, as well as being unalterable with prolonged UV light exposure.
14. Decorated surfaces of electrical non-conductive materials with continuous conformation and treated with the decoration method according to claim 5, wherein the electrically conductive PVD coating has the electrochemical oxidation decoration obtained on the PVD coating with shimmering and iridescent visual effects.
15. Decorated surfaces of electrically conductive materials with continuous or discontinuous conformation and treated with the decoration method according to claim 4, wherein the superimposition of the decorations creates a three-dimensional graphic shape to the user's view.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0029]
[0030]
[0031]
[0032]
[0033]
[0034]
DETAILED DESCRIPTION OF SOME ACTUATION MODES
[0035]
[0036] The aesthetic effect obtained shows a different conformation of the graphic shape applied with the same masking. As already stated for the graphic shape 3, the application of the PVD coating softens the lines thereof, i.e., blurs the graphic shape, but the subsequent application of a further electrochemical action, i.e., on the metallic coating layer below the PVD micrometre covering it, highlights and marks the contours, triggering particular decorative effects due to the electrochemical action on the metallic material of the deposited PVD of oxides, carbides and metallic nitrides transforming them with greater visibility to the user. This gives the decoration obtained a new and different aesthetic effect. Furthermore, the decorative effect obtained is not constant but depends on the metallic material used for the PVD coating and on the electrochemical action and electrical current applied in the electrochemical action on the metallic PVD coating layer, creating new oxides, in addition to the oxides of the electrochemical action on the base metal, which generate shimmering and iridescent effects as well as more marked colours and combined with the decoration oxides previously obtained.
[0037] The graphic shape 12 can be further modified and rendered with a three-dimensional effect if the applications of the original electrochemical decoration of the graphic shape 3, directly on the metallic surface of the sheet or plate 2, and of the subsequent application of the decoration at such graphic shape on the applied PVD coating, are made to create a scenic depth effect of the decoration obtained as a figure obtained in 3D i.e., three-dimensional. This additional possibility of 3D graphic shape combined with the shimmering and iridescent effect indicated makes the decoration obtained even more refined and attractive to the user, whether it is applied to surfaces intended for decorative indoor furniture or if it is intended to be applied to surfaces for outdoor furniture.
[0038] Moreover, in the graphic shape 13 made with the electrochemical decoration directly on the PVD coating layer of the zone 14, without making a prior decoration on the surface of the sheet or plate 2 below, the decoration effect remains, i.e., it is shown with shimmering and iridescent contours, obtaining a new decorative effect, given the electrochemical decoration action which, performed directly on the PVD coating, is regardless of the base material on which the PVD coating is made. In fact, since making the PVD metallic coating on plastic, glass, ceramic and carbon fibre is known and the same coating is an electrical conductor, this form of decoration of the surface of the PVD coating alone can advantageously be decorated with electrochemical action, moreover including the shimmering and iridescent effects found on the PVD after the described electrochemical decoration action.
[0039]
[0040] The simplest device 20 for flat materials of limited size, in
[0041] The electrochemical action is activated by the passage at a short distance of an electrode 27, not in contact with the surface 25 being treated, immersed in an electrolytic solution bath, with level 28, which allows the activation of the electrochemical action on the treated surface leaving the parts covered by the masking 26 in their original state without the electrochemical oxidation action intervening on said surface. The electrode is connected to the other end 29, generally the phase, of the electrical circuit for activating the electrochemical action of the expected decoration.
[0042] The decoration action of
[0043] Furthermore, in
[0044] Moreover, in
[0045] A device 60 for planar materials of limited size, in
[0046] The electrochemical action is activated by the passage at a short distance of a roller electrode 69, not in contact with the surface of the sheet 65 being treated, immersed in an electrolytic solution bath, with level 70, which allows the activation of the electrochemical action on the treated surface leaving the parts covered by the masking 66 in their original state without the electrochemical oxidation action intervening on said surface. The roller electrode 69 is connected to the other end 71, generally the phase, of the electrical circuit for activating the electrochemical action of the expected decoration. The electrode is placed to roll facing the surface being treated, generating the activation of the electrochemical action of the expected decoration even several times with alternating motion by the action of a robotic mechanical arm.
[0047] The decoration action of
[0048] To complete a device 75 for flat materials of limited size, in
[0049] The electrochemical action is activated by the passage at a short distance of the double electrode 76, not in contact with the surface 79 being treated, immersed in an electrolytic solution bath, with level 70, which allows the activation of the electrochemical action on the treated surface leaving the parts covered by the masking 83 in their original state without the electrochemical oxidation action intervening on said surface. The double electrode 76 is placed to slide facing the surface being treated, generating the activation of the electrochemical action of the expected decoration even several times with alternating motion by the action of a robotic mechanical arm.
[0050] The decorative action of
[0051] The device of
[0052] Similarly to what is stated for continuous surfaces in non-conductive base material such as plastic, glass, crystal, ceramic and the like, with a double electrode 51, in
[0053] The use of the method for decorating metallic or non-metallic surfaces treated with PVD according to the invention occurs as already described above and in which the execution variants of the decoration with electrochemical action are shown below.
[0054] With the decoration process with electrochemical oxidation, a conversion reaction is carried out of the surface part, less than 100 nanometres of the natural oxide of the metal or of the surface part of the PVD coating deposited on the metallic or non-metallic material to be decorated, always within 100 nanometres. This decoration creates a compact and thin oxide layer, without any porosity, conditioning the natural metal oxide or the deposited PVD coating. In the case of prior deposit of the decorative PVD, the layer deposited by the PVD about 1000 nanometres thick, goes to superimpose the natural oxide which, as indicated, is of the order of 100 nanometres.
[0055] As a result of the combination of the decorative treatments mentioned above, interesting chromatic effects are formed as a result of the non-homogeneous combination which generates the treatment on the surface part of the PVD deposit, producing various interference colouring.
[0056] Moreover, even a treatment with an aesthetic colouring purpose similar to the PVD deposit, such as the treatment of galvanic chromium coating with thin thickness called “electrocolouration”, allows to make, with the same electrochemical process, decorations on the surface of a stainless steel plate previously treated with electrocolouration; the decorative effect almost completely modifies the thickness of the thin chromium oxide coating created, and gives rise to decorative forms which are still appreciable even if less incisive than the decorations obtained on PVD deposit and without obtaining iridescent effects.
[0057] Other differences that make PVD preferable to the “electrocolouration” treatment are as follows. The PVD deposit, with respect to the aforesaid “electrocolouration” treatment, occurs at room temperature without the need for long stops in galvanic baths at a temperature of 80-90°, which are necessary for the deposit of chromium to increase its oxide, and in the complete absence of any dangerous chemical emission for the environment. The electrocolouration treatment does not increase the technical features of the metallic support which are obtainable, however, with the PVD deposit.
[0058] The application of the electrochemical oxidation process, by means of the devices described above, is regularly carried out at low voltage, from 6 to 14 volts in alternating current, AC, and current of 100 Ampere per square surface metre, at a speed of 20 seconds per square metre. Depending on the desired colour intensity, repeated steps can be carried out to obtain different colour intensities (from a minimum of 4 to 8 steps). Therefore, with the electrochemical decoration speed of a metallic surface or a PVD layer applied to a surface to be decorated, the treatment time with the electrical activation data shown above is 2 minutes for each square surface metre treated.
[0059] Following the methods of execution of the electrochemical decoration described, and claimed in this invention, the application of the decoration method is very fast with respect to the usual galvanic, electroerosion or electrodeposition treatments, as well as the time to obtain a minimum deposit of a PVD layer, since the process described in the method of this invention does not perform any deposit and does not perform any erosion of metals, but only a conditioning of the oxide present in the treated outer surface which is less than 100 nanometres.
[0060] A surface investigation of a surface treated with the described method is possible with classical chemical analyses, as well as with investigation with the Electronic Microscope and also specifically to distinguish the oxide layers from each other by Reflection Spectroscopy (for example RAMAN spectroscopy).
[0061] In the art it is known to use a screen printing net, as mentioned in
[0062] Furthermore, a single electrode 27 or 38 or double electrode 51 or 76 can operate if a buffer is placed between the electrode and the metallic treatment surface or the PVD coating which, if soaked with electrochemical solution, in addition to performing the function of a spacer between the surface and the electrode, bathes both the electrode and the surface being treated, making the electrochemical action possible.
[0063] The advantages in using a method for decorating metallic or non-metallic surfaces treated with PVD as described can be summarized as follows.
[0064] With the application of the PVD coating to the conductive surfaces already decorated with selective electrochemical decoration, even by masking the treated surface, an improvement in the performance of resistance to external agents of the decorated surface is achieved, in fact the protection obtained by the PVD coating makes the decorated surface more unattackable with respect to the original surface, however, the creations of known PVD coatings do not have decorations of any kind, thus even one PVD decoration is new and more decorative if it is placed to cover an electrochemical decoration of an electrically conductive surface.
[0065] Moreover, the creation of a PVD coating on a conductive surface, even if not continuous or even non-conductive, but continuous, allows to further decorate the metallic PVD coating, which in itself is electrically conductive, obtaining new graphic shapes of decoration in relation to the metallic material deposited with the PVD and the particular regulation of the electrical parameters of the electrochemical decoration action. Thereby, the graphic shape of the decoration obtained on the PVD coating has shimmering and iridescent characters which are not possible with a simple electrochemical decoration of metals, while the use of specific mixtures of metals or metal oxides of the PVD coating and the electrical parameters of the decoration allow it.
[0066] A further and not previously known advantage is obtained if a graphic shape made on an electrically conductive surface, for example the graphic shape 3 of the example of
[0067] Obviously, a person skilled in the art, in order to satisfy specific and contingent requirements, may make numerous modifications to a decorating method of metallic or non-metallic surfaces treated with PVD, as previously described, all nevertheless falling within the scope of protection of the present invention as defined by the following claims. In particular, although less conveniently, it is known that in the decorated surfaces a decoration with a three-dimensional effect is obtainable with the execution of an electrochemical decoration with different maskings but made for the purpose and with repeated applications on the same surface point in the decoration treatment, this effect can also be used on the PVD coating of the decorated surfaces object of the present disclosure.