AUTHENTICATION OF METALLIC OBJECTS

Abstract

The present invention provides an anti-counterfeit marking technique for verifying authenticity of objects using x-rays fluorescence (XRF) analysis.

Claims

1. A marker composition comprising at least one XRF-sensitive marker and at least one surface binding material, wherein the concentration of the at least one marker is between 0.1 and 10,000 ppm.

2. The composition according to claim 1, wherein the concentration of said marker is between about 0.1 and 200 ppm, or between about 0.1 and 20 ppm.

3. A film-forming composition for forming a film on at least a region of a surface material, the composition comprising at least one XRF-sensitive marker, at least one surface binding material and at least one chemical etchant for increasing surface contact with said marker and said binder.

4. The composition according to claim 1, wherein the XRF sensitive marker is a compound comprising one or more element which in response to X-Ray or gamma-ray radiation emits an x-ray signal with spectral features characteristic of the element.

5. The composition according to claim 4, wherein said element is selected from the group consisting of Si, P, S, Cl, K, Ca, Br, Ti, Fe, V, Cr, Mn, Co, Ni, Ga, As, Fe, Cu, Zn, Ga, Rb, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Ag, Cd, In, Sn, Sb, Te, I, Cs, Ba, La and Ce.

6. The composition according to claim 1, further comprising at least one polymerization initiator, and optionally at least one agent selected from at least one adhesion promoter, at least one wetting agent, at least one etching agent, at least one dispersant and at least one solvent.

7. The composition according to claim 1, the composition being selected from: the compositions being selected from: a composition comprising a marker material comprising Ca and/or Ti and/or Mo and/or Zn and/or Zr and/or Sb, wherein the at least one binding material is acrylate-based; said etching material is selected from phosphoric acid and 2-propenoic acid; a composition comprising a marker material comprising Ca and/or Ti and/or Mo and/or Zn and/or Zr and/or Sb, wherein the at least one binding material comprises at least one binder material and at least one adhesion promoter; said etching material is phosphoric acid and/or 2-propenoic acid; a composition comprising a marker material comprising Ca and/or Ti and/or Mo and/or Zn and/or Zr and/or Sb, wherein the at least one binding material comprises at least one binder and at least one adhesion promoter being methacryloxy silane and/or methacryloxypropyl terminated polydimethylsiloxane and/or acrylic silane and/or aromatic acid methacrylate half ester; said etching material is phosphoric acid and/or 2-propenoic acid; a composition comprising a marker material comprising Ca and/or Ti and/or Mo and/or Zn and/or Zr and/or Sb, wherein the at least one binding material comprises at least one binder material selected from acrylate resins and at least one adhesion promoter; said etching material is phosphoric acid and/or 2-propenoic acid; a composition comprising a marker material comprising Ca and/or Ti and/or Mo and/or Zn and/or Zr and/or Sb, wherein the at least one binding material comprises at least one binder material selected from acrylate resins and at least one adhesion promoter being methacryloxy silane and/or methacryloxypropyl terminated polydimethylsiloxane and/or acrylic silane and/or aromatic acid methacrylate half ester; said etching material is phosphoric acid and/or 2-propenoic acid; a composition comprising a marker material comprising an XRF-sensitive element, at least one binding material being acrylate-based; and an etching material being phosphoric acid and/or 2-propenoic acid; a composition comprising a marker material comprising an XRF-sensitive element, at least one binding material comprising at least one binder material and at least one adhesion promoter; and an etching material being phosphoric acid and/or 2-propenoic acid; a composition comprising a marker material comprising an XRF-sensitive element, at least one binding material comprising at least one binder and at least one adhesion promoter being methacryloxy silane and/or methacryloxypropyl terminated polydimethylsiloxane and/or acrylic silane and/or aromatic acid methacrylate half ester; and an etching material being phosphoric acid and/or 2-propenoic acid; a composition comprising a marker material comprising an XRF-sensitive element, at least one binding material comprising at least one binder material selected from acrylate resins and at least one adhesion promoter; and an etching material being phosphoric acid and/or 2-propenoic acid; and a composition comprising a marker material comprising an XRF-sensitive element, at least one binding material comprising at least one binder material selected from acrylate resins and at least one adhesion promoter being methacryloxy silane and/or methacryloxypropyl terminated polydimethylsiloxane and/or acrylic silane and aromatic acid/or methacrylate half ester; and an etching material being phosphoric acid and/or 2-propenoic acid.

8. An object having on at least a region thereof a film comprising at least one XRF-sensitive marker and at least one binding material, wherein the concentration of said XRF-sensitive in the film is between about 0.1 and 10,000 ppm.

9. The object according to claim 8, wherein the concentration of said XRF-sensitive in the film is between about 0.1 and 200 ppm or between about 0.1 and 20 ppm.

10. The object according to claim 8, wherein the film comprises an amount of at least one marker material, at least one binder material selected amongst poly-acrylates, and wherein the film having a thickness of between 0.1 and 4 microns.

11. The object according to claim 8, wherein the film comprises two or more marker materials, each being based on a different element.

12. The object according to claim 8, being a metallic object.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0148] In order to better understand the subject matter that is disclosed herein and to exemplify how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

[0149] FIG. 1 is a schematic illustration of a method for marking and authenticating metallic objects, according to some embodiments of the invention.

[0150] FIG. 2 is a schematic illustration of a method for marking and authenticating metallic objects, according to further embodiments of the present invention.

[0151] FIG. 3 is a schematic illustration of a system for marking and authenticating metallic objects according to certain embodiments of the present invention.

[0152] FIGS. 4A-B provide an example x-ray response signal and the corresponding enhanced response x-ray signal, respectively.

DETAILED DESCRIPTION OF EMBODIMENTS

[0153] Reference is now made to FIG. 1 which is a schematic illustration of a method for marking and authenticating metallic objects, according to some embodiments of the invention. In the Figure, the metallic object is generally referenced 100. Procedure 102 of the method is carried out in a first preparation stage, in which the metallic object is marked. In procedure 102 a marking composition is applied to the metallic object. The marking composition includes one or more markers and one or more binders. According to this embodiment, the marker comprises a selected element or compound which can be identified by its x-ray fluorescence (XRF) signature. Namely, a compound generating an x-ray signal in response to being irradiated by x-ray or gamma-ray radiation wherein the response x-ray signal includes one or more spectral features associated with and identifying the material. Hereinafter, the particular XRF signature of a marker is referred to as a “marking signal”.

[0154] The binder binds the marker to the surface of the metallic object, as explained herein. For example, the binder may be a thermoset polymer such as polyurethane acrylate, poly-acrylate, poly-epoxy amine, poly-epoxy anhydride, poly-ester, and poly-styrene. In addition to markers and the binders the marking composition may include solvents, and dispersants which assist in dissolving the marker enabling the marking composition to contain suitable concentrations of markers. For example, the marking composition may include a benzene ring substituted with OH and/or COOH groups. The marking composition may also include adhesion promoters which assist in binding the marker to the surface of the metallic object. For example, the marking composition may include hydroxy-functional copolymer with acidic groups, oligomers in the form of aromatic acid methacrylate half ester or aromatic acid acrylate half ester blends in solvent or monomer.

[0155] The XRF signatures of one or more of the binders (hereinafter referred to as “auxiliary signals) may be used, in addition to the marking signals to authenticate the metallic object. In addition, the XRF signature of at least one of the metals present in the metallic object for authenticating the metallic object (hereinafter the marking signal, the auxiliary signal and the XRF signatures of the metals in the metallic object are collectively referred to as “authenticating signals”).

[0156] The marking composition does not affect the mechanical/physical or chemical properties of the metallic object. In particular, the marking composition is invisible to a naked eye and does not deform or alter any physical features which may be printed engraved or coined on the surface of the metallic object. Furthermore, the marking composition does not alter the electric or magnetic properties (e.g. conductivity, capacitance, magnetic susceptibility) of the metallic object. Therefore, any electrical or magnetic test conducted on the metallic object measuring any of the above properties does not reveal whether the metallic object is marked by the marking composition or not.

[0157] Procedures 104, 106, 108 and 110 are carried out at a second authentication stage wherein the metallic object is examined and authenticated. In procedure 104, the metallic object is irradiated with x-ray or gamma-ray radiation causing the metallic object and the marking composition, if present, to generate x-ray signals in response. In procedure 106 the response x-ray signal arriving from the metallic object is detected. In procedure 108 the response x-ray signal is processed in order to reduce noise and clutter caused, for example, by back-scattering, instrumental noise of the detection device and foreign materials in the vicinity of the metallic object, and to amplify or enhance the authenticating signals relatively to the background. The processing may include for example statistical processing, such as time series analysis, which may be carried out to remove at least one of the trend and/or periodic components from the spectral profile (e.g. from the power spectrum) of the detected X-Ray response signal, and/or both trend and periodic components. However, naïve filtration of the background and the noise, for example by using common methods such as quasi-Gaussian spectroscopy amplifier and Gaussian filtering may also significantly reduce all or part of the authentication signals. Hence, more advanced signal processing methods should be employed. For example, the response x-ray signal may be processed using statistical methods such as time series analysis. The output of procedure 108 is an “enhanced signal” having an improved Signal to Noise Ratio (SNR) and Signal to Clutter Ratio (SCR) from which the authenticating signals can be accurately derived.

[0158] In FIGS. 4A and 4B an example x-ray response signal and the corresponding enhanced response x-ray signal are respectively shown. As shown, much of the noise and clutter appearing in the response x-ray signal is suppressed in the enhanced response signal. The prominent peaks appearing in the enhanced response signal of FIG. 3B associated mainly with the authenticating signals. Consequently, the enhanced response signal enables the user to identify the presence of the authenticating signals with better sensitivity, as can be seen by comparing the scale of the y-axes in FIGS. 4A and 4B. This improved sensitivity allows the user to detect and identify significantly smaller amounts of markers and binders found in the marking composition. For example, the method 100 allows the user to detect markers within the marking composition in concentrations of 0.1-100 ppm. Furthermore, the enhanced response signal can be used to measure the concentrations of the different markers and the binder within the marking composition to a high accuracy (e.g. 0.1-100 ppm).

[0159] In procedure 110 the authenticating signals are identified in the enhanced response signal, and the authenticity of the metallic object is determined according to the presence of these signals. For example, the metallic object may be deemed as authentic if the marking signals (one or more) are detected, alternatively the metallic object may be deemed authentic only if in addition to the marking signal one or both of (i) the at least one auxiliary signal and (ii) at least one XRF signatures of at least one of the metals present in the metallic object, are identified in the enhanced response signal.

[0160] Reference is now made to FIG. 2 which is a schematic illustration of a method for marking and authenticating metallic objects, generally referenced 200, according to a further embodiment of the present invention. Procedures 202 and 204 of the method 200 is carried out in a first preparation stage, in which the metallic object is marked and according with a preselected code. Procedures 206-214 are carried out in a later authentication stage. Procedures 206-210 are generally similar to procedures 104-108 of method 100 described above and therefore would not be described in detail below.

[0161] In procedure 202 a marking composition including one or more markers and one or more binders, is applied to the metallic object, wherein the concentrations of the one or markers and the one or more binders in the marking are determined according to a preselected code. Hence, for example, using a single marker which may be present in the marking composition in K different concentrations corresponds to a preselected code with K different code-words (each code-word corresponding to a different concentration). In case where N different markers are used each in K possible concentrations, a corresponding preselected code includes K to the power of N code-words.

[0162] The application of the marking composition is implemented similarly procedure 102 of method 100. The particular markers and binders present in the marking composition and their concentrations within the marking composition are set according to a preselected code. The preselected code may be used purely for authentication purposes. That is, the code is used to verify at a later stage that the metallic object includes the markers and binders in the correct concentrations as preselected. Alternatively, the code may be used also to provide additional information associated with the metallic object and/or the production process, such as the production/marking date, the identity of the manufacturer, a production/serial number, or the production cite of the metallic object. In procedure 204 the preselected code is a database. The preselected code may also include information relating to the concentration of at least one metal in the metallic object.

[0163] In procedures 206 the metallic object is irradiated with x-ray or gamma-ray radiation causing the metallic object and the marking composition to generate x-ray signals in response, and in procedure 208 the response x-ray signal arriving from the metallic object is detected in a similar way to procedures 104 and 106 of method 100 respectively. Likewise, in procedure 210 response x-ray signal is processed to obtain an enhanced response signal similarly to procedure 108 of method 100.

[0164] In procedure 212 the enhanced response signal is utilized to measure the concentrations of the one or more markers and the binder associated with the auxiliary signal. Since the enhanced response signal, in which noise and clutter are greatly reduced a very accurate measurement, allows for an accurate measurement even for very low concentrations of the markers and binders. Additionally, the concentration of the at least one of the metals present in the metallic object and associated with the preselected code may also be measured.

[0165] Since the accuracy and resolution of the measurement of the different concentrations in high (for example up to 0.5-30 ppm) the number of different concentrations of each of the marker/binder included in the preselected code is relatively high. For example, 10-200 different level of concentrations for each marker or binder may be included in the marking composition and the preselected code.

[0166] In procedure 214 the concentrations measured in procedure 212 are compared with the concentrations derived from the preselected code and the authenticity of the metallic object is determined accordingly. In an example in order for the metallic object to be deemed authentic the concentrations measured in procedure 212 must fully agree with the concentrations level as derived from the preselected code. Alternatively, a certain margin of error can be tolerated and the metallic object is deemed authentic if the concentrations measured in procedure 212 are similar up to a selected error margin to the concentration derived from the preselected code.

[0167] Reference is now made to FIG. 3 which is a schematic illustration of a system for marking and authenticating metallic objects (hereinafter “authenticating system”) (e.g. spheres), generally referenced 300, according to an embodiment of the present invention. System 300 includes a marking module 302, a reading module 304, a signal processor 306, and a database 308. Reading module 304 includes a radiation emitter 310 and a radiation detector 312. The processor 306 is coupled to the reading module 304 and to the database 308. The database may also be coupled to the marking module 302.

[0168] The marking module 302 may apply the marking composition to new coins at the production site of the metallic objects during the production process or in a post-production stage. Alternatively, the marking may be applied to metallic objects that have already been used at a separate designated facility. The marking module may be configured, for example, to carry out the procedure 104 of method 100 to apply a marking composition to a metallic object comprising at least one marker and a binder.

[0169] The different markers and binders included in the marking composition and their respective concentrations may be determined according to a preselected code. Namely the preselected code is used as a ‘recipe’ for preparing the marking composition. The preselected code may be stored in database 208.

[0170] The reading module 304 is configured to emit an x-ray and/or gamma-ray radiation (primary radiation) towards the metallic object under examination and detect the response x-ray signal (secondary radiation) that is emitted in response from the metallic object. The radiation emitter 310 emits an x-ray and/or gamma-ray radiation towards the metallic object and the detector 312 detects the response x-ray signal arriving from the metallic object. The reading module transmits the response x-ray signal to the signal processor 306 and optionally to the database 308 as well. The reading module may be constructed as a single device such as handheld or portable XRF analyzer, or a benchtop XRF spectroscopy device. Alternatively, radiation emitter 310 and radiation detector 312 may be constructed as separate devices. The reading module 304 may be either of-the-shelf device integrated within the authenticating system 300 or a device which is specifically designed and constructed for exciting and detecting a response signal from the metallic object. The reading module 304 may be configured, for example, to carry out procedures 104 and 106 of method 100 to irradiate the metallic object with x-ray or gamma ray radiation and to detect the response x-ray signal arriving from the metallic object.

[0171] The signal processor 306 receives the response x-ray signal from the reading module and processes it so as to filter out the background radiation noise and clutter from the response signal. It should be noted, that common filtration methods such as for example quasi-Gaussian spectroscopy amplifier and Gaussian filtering if applied naively to the response x-ray signal may reduce or obscure also the authentication signals. To overcome this problem the signal processor 306 may employ more advanced methods for processing the response signal, for example statistical methods such as time series analysis in order to obtain an enhanced response signal with an improved SNR and SCR. The signal processor may be configured, for example, to carry out procedures 106 and 108 of method 100 to process the response x-ray signal and obtain an enhanced response signal, and to identify the at least one marking signal and optionally the auxiliary signal an/or the XRF signature of at least one of the metals present within the metallic object.

[0172] According to some embodiments of the present invention, the signal processor 306 may also measure the concentrations of the markers and binders present within the marking composition, and in addition the concentration of one or more metals present within the metallic object. The signal processor is also configured to compare the measured concentrations with the concentrations derived from the preselected code which is stored in the database 208, and determine its authenticity accordingly. The signal processor may be configured, for example, to carry out the procedures 212 and 214 of method 200 to utilize the enhanced response signal to measure the concentrations of the at least one marker and optionally at least one of the materials present in the binder within the marking composition, and optionally the concentration of at least one metal within the metallic object, and to compare the measured concentrations of the at least ones marker and optionally at least one of the materials present in the binder, and at least of the metals present in the metallic object to the preselected code.