MXPA01005904A - Resonant tag with a conductive composition closing an electrical circuit - Google Patents

Abstract

Briefly stated a tag (10) includes a dielectric substrate having first and second opposite principal surfaces. An electrical circuit having an electrically conductive pattern (18) is formed on at least one of the principal surfaces of the dielectric substrate, the conductive pattern including a gap (22) which establishes an electrical open circuit. An electrically conductive composition (24) including electro-conductive particles (24) is provided for bridging the gap in the conductive pattern to temporarily establish an electrical closed circuit which resonates when exposed to electromagnetic energy at a frequency within a predetermined frequency.

Description

RESONANCE LABEL WITH A CONDUCTIVE COMPOSITION THAT CLOSES AN ELECTRICAL CIRCUIT BACKGROUND OF THE INVENTION The present invention relates to security labels and, more particularly, to security labels that can be deactivated for use with electronic article surveillance systems for the detection of unauthorized removal of articles from secured spaces. Electronic article surveillance (EAS) systems to detect and prevent theft or unauthorized removal of items or goods from retail establishments and / or other facilities, such as bookstores, are well known and widely used. In general, security systems employ a security tag or label that is fixed and related, or otherwise secured, to an item or item to be protected or in its packaging. Security labels can take many different sizes, shapes and figures, depending on the particular type of security system in use, the type and size of the item, etc. In general, said security systems detect the presence of an active security label as the security label (and thus the protected article) passes through a surveillance zone or passes through or near a security control point .

Certain security labels of the prior art work primarily with electronic security systems for detecting electromagnetic radiofrequency (RF) field interruption, such as, but not limited to, those described in the U.S. patent. No. 3,810,147, entitled "Electronic Security System", patent of E.U.A. No. 3, 863,244, entitled "Electronic Security System Having Improved Noise Discrimination", and patent of E.U.A. No. 5,276,431, entitled "Security Tag For Use With Article Having Inherent Capacitance", and its instrumentations and counterparts available in the market. Said electronic security systems in general establish an electromagnetic radio frequency (RF) field in a surveillance zone through which the articles must pass when being extracted from the controlled facilities. A label having a resonance circuit is attached to each article, and the presence of the resonance circuit in the surveillance zone is detected by a receiving system to signal the unauthorized removal of an article. Items that are authorized to be removed from controlled facilities require that the attached security tag be deactivated before extraction. The physical deactivation of a tag that has a resonance circuit can be done by: 1) altering the tag to de-tune or disable the resonance circuit, 2) protection of the resonant circuit of the incident RF energy, or 3) withdrawal of the Article tag All of these physical deactivation techniques require that the security label be identifiable and accessible, which prohibits the use of labels found within the merchandise in locations that are not displayed or labels concealed in or on the packaging. The trend in the electronic article surveillance industry is to install a label on a product at the time of its manufacture, since at this stage, it is relatively inexpensive to install the label and also because it can be concealed or hidden from view for encourage fraud. Placing the label on the product or product packaging requires that the label has a remote deactivation. Remote deactivation of the label can be achieved through electromagnetic means. Said labels can be deactivated in a conventional manner: at the collection counter or another location by placing them for a moment on or near a deactivation device, which subjects the label to RF energy at a sufficient level of energy to cause one or more of the components of the resonance circuit of the safety label short circuit or open, depending on the detailed structure of the label. Typical methods for causing a short circuit or opening the circuit employ dielectric failure and fusible links. All of these techniques require a predetermined RF energy level of specialized equipment to deactivate the labels appropriately.

There are circumstances when labels can be installed on articles, and articles are put into legitimate use without first having disabled the label. There is a need to permanently deactivate such labels during their use without the benefit of specialized equipment to minimize the likelihood that the label will subsequently create a false alarm, if the item were subsequently to pass through an article surveillance system.

BRIEF DESCRIPTION OF THE INVENTION Broadly speaking, the present invention comprises a label that includes a dielectric substrate having first and second opposed major surfaces. An electrical circuit having an electrically conductive pattern is formed on at least one of the main surfaces of the dielectric substrate, the conductive pattern includes a space that establishes an electric open circuit. An electrically conductive composition that includes electrically conductive particles is provided to form a bridge with the space in the conductive pattern to temporarily establish an electrical closed circuit that causes the resonance circuit to resonate when exposed to electromagnetic energy at a frequency within a range of default frequency. The present invention further comprises a method for making a label. The method includes the steps for forming an electrical circuit having an electrically conductive pattern on a dielectric substrate; form a space in the conductive pattern to establish an open circuit; apply a liquid composition to the conductive pattern to form a bridge with the space in the conductive pattern; and drying the liquid composition to form an electrically conductive composition to cause the circuit to resonate upon exposure to electromagnetic energy at a frequency within a predetermined frequency scale. The present invention further comprises a method for deactivating a tag. The method includes the steps for forming an electrical circuit having an electrically conductive pattern on a dielectric substrate; form a space in the conductive pattern to establish an open circuit; apply a liquid composition so that the conductive pattern bridges the space in the conductive pattern; drying the liquid composition to form an electrically conductive composition to cause the circuit to resonate upon exposure to electromagnetic energy at a frequency within a predetermined frequency scale; and restoring the space in the conductive pattern, so that the circuit no longer resonates at a frequency within the predetermined frequency scale.

BRIEF DESCRIPTION OF THE DRAWINGS The above brief description, as well as the following detailed description of a preferred embodiment of the invention will be better understood by reading it together with the accompanying drawings. For the purpose of illustrating the invention, embodiments are shown in the drawings that are preferred herein. However, it should be understood that the invention is not limited to the precise arrangements and instrumentation illustrated. In the drawings: Figure 1 is a plan view of a first major surface of a typical prior art label; Figure 2 is a plan view of a second opposing main surface of the label illustrated in Figure 1; Figure 3 is a plan view of a first major surface of a label having a space in a conductive path in accordance with a preferred embodiment of the present invention; Figure 4 is an enlarged fragmentary view of a portion of the label of Figure 3, illustrating the space in the conductive path; Figure 5 is an elongated fragment view of a portion of the label of Figure 3 which illustrates a conductive composition that bridges the space; and Figure 6 is a cross-sectional view of the space in the conductive path with the conductive bridge-making composition, taken along line 6-6 of Figure 5.

DETAILED DESCRIPTION OF THE INVENTION Next, with respect to the drawings, where the same reference numerals are applied to corresponding elements in all the figures, a typical security label or label 10 is illustrated in FIGS. 1 and 2 for use with an electronic security system of articles. In general, label 10 is of a type that is well known in the art electronic security systems technique, which has two states of operation: 1) an active state in which the label 10 can be detected by an electronic security system of articles, and 2) an inactive state in which the label 10 is not usually detected by an electronic article security system. As is well known in the art, the label 10 is adapted to be secured or, otherwise, in an article or item that bears it, or in the packaging of said article for which security or surveillance is sought. The label 10 can be secured to the article or its packaging at the place of retail sale or other installation, or as is preferred today, insure it or incorporate it into the article or its packaging by the manufacturer or wholesaler of the article. The label 10 is used in conjunction with an electronic article security system (not illustrated), in particular an electronic security system for articles of the radio frequency or RF type, such as for example exemplified by US Patent No. 3,863,244 , entitled "Electronic Security System Having Improved Noise Discrimination" which is incorporated herein by reference. Such electronic article security systems are well known in the art, and therefore, a complete description of the structure and operation of such electronic article security systems is not necessary for the understanding of the present invention. Suffice it to say that such electronic article security systems establish a surveillance area or zone, generally close to an entrance or exit from a facility, such as a retail store. The function of the security system is to detect the presence within the surveillance zone of an article that has an active security label 10 secured to the article or secured to the article packaging. The security tag 10 includes components described hereinafter in greater detail, which establishes a resonance circuit 11 that resonates and exposes it to RF energy at or near a predetermined detection resonance frequency. A typical electronic item security system employing label 10 includes means for transmitting energy from! RF of a frequency at or near the resonance frequency of the security tag 10 in or through the surveillance zone and means to detect an RF field interruption that is caused by the presence of the resonance circuit 11 of the tag 10 to establish the presence of the security label 10 and, consequently, a protected article within the surveillance zone. The typical label 10, illustrated in FIGS. 1 and 2, generally comprises a rectangular, flat insulator or dielectric substrate 12 having first and second opposing main surfaces 14, 16. The substrate material can be any solid material or structure mixed material, as long as it is insulating and can be used as a dielectric element. Preferably, the substrate 12 is formed of an isolated dielectric material of a type already known in the art, for example, a polymeric material, such as polyethylene. However, those skilled in the art will recognize that other dielectric materials may alternatively be used to form the substrate 12. The tag 10 further comprises circuitry located on the substrate 12 to establish at least one resonance circuit 11 by forming elements or components of predetermined circuits in the main surfaces 14, 16 of the substrate 12 which will be described hereinafter. The circuit elements are formed by a combination of a first conductive pattern 18 imposed on the first major surface 14 of the substrate 12, which is best seen in Figure 1; the surface is arbitrarily selected as the upper surface of the label 10, and a second conductive pattern 20 is imposed on the opposite side or second major surface 16 of the substrate 12 (best seen in Figure 2). The conductive patterns 18, 20 are formed on the substrate surfaces 14, 16, respectively, with electrically conductive materials of a known type and in a manner that is well known in the art electronic article surveillance technique. The conductive material is preferably found in patterns by a subtraction procedure (ie chemical etching), whereby the unwanted conductive material is removed by etching after having protected the desired conductive material to form the conductive patterns 18, 20, almost always with a printed ink resistant to chemical attack. A suitable method for forming such conductive patterns is described in detail in the U.S.A. No. 3,913,219, entitled "Planar Circuit Fabrication Process" which is incorporated by reference. In the present embodiment, the conductive material is aluminum; however, other conductive materials (eg gold, nickel, copper, phosphor bronzes, brass, solder, high density graphite, conductive epoxies filled with aluminum or conductive epoxies filled with silver) can be replaced by aluminum without changing the nature of the circuit of resonance 11 or its operation. Although it is preferred that the material and the methods explained in the patent of E.U.A. No. 3,913,219 mentioned above and that another prior art is employed to manufacture the security tag 10, those skilled in the art will appreciate that other suitable electrically conductive materials and / or alternative manufacturing methods may be employed. The first and the second conductive patterns 18, 20 establish a resonance circuit 11 having a resonance frequency within the electronic article security detection scale with which the label 10 is employed. In the case of the label 10, the resonance circuit 11 consists of an inductance that is electrically connected in parallel with a capacitance. As best illustrated in Figure 1, the inductance comprises an inductive coil 26 formed within the first conductive pattern 18. However, it can be recognized that the inductive coil 26 can be formed within the second conductive pattern 20, or it can be formed in both conductive patterns 18, 20. Alternatively there could be a plurality of inductive coils formed within the first and / or second conductive patterns 18, 20. In addition, the conductive patterns 18, 20 do not need to form an inductive coil 26, but for example, a inductive reactance from the formation of an electric transmission line constructed by means of microstrip or tape line methods and remaining within the spirit and scope of the invention. The resonance circuit of the label 10 further includes a capacitor element having a first plate formed by a first generally planar rectangular portion 28 of the first conductive pattern 18, as illustrated in FIG. 1, and a second plate formed by a second generally rectangular planar portion 30 of the second conductive pattern 20, as illustrated in Figure 2. The conductive planar zone patterns 28, 30 are separated by the dielectric substrate 12 to form the capacitor element. With respect to FIGS. 1 and 2, the resonance circuit 11 is formed by the combination, in a series of cycles, of the inductive coil 26 electrically connected at one end to the generally rectangular planar portion 28 of the first conductive pattern 18. and at the other end to the generally flat rectangular planar portion 30 of the second cord pattern 20, by a bond (not shown) passing through the dielectric substrate 12 to electrically connect the conductive patterns., 20. Although the preferred embodiment of the label 10 includes a single capacitor formed by the portions of the flat area 28, 30, the multiple capacitor elements can be used alternately and still remain within the spirit and scope of the invention. The label 10 as described so far is typical of security labels that are well known in the electronic security and surveillance art and have been in general use. In the formation of said safety labels, the area of the inductive coil 26 and the overlapping areas of the capacitor plates 28, 30 are carefully selected so that the resonance circuit 11 formed in this manner has a predetermined resonance frequency which in general corresponds or approaches a detection frequency employed in an electronic article security system for which the label 10 to be used is designed. In the present embodiment, the tag 10 resonates at or near 8.2 megahertz which is a frequency commonly employed by electronic security systems of articles from various manufacturers. However, this specific frequency will not be considered a limitation of the present invention. The resonance circuit 10 can be altered through the use of remote electronic devices. Said alteration of circuits, which may be activation or deactivation of the label 10, may occur in a manufacturing facility or a collection counter when a person purchases an item with a security label 10 placed or fixed, depending on the intended use of the item. label. The deactivation of the label 10, which almost always occurs at the point of sale, prevents the resonance circuit 11 from resounding so that the electronic article security system no longer detects the article in the surveillance zone. Various physical methods have been developed to deactivate security labels 10, such as physically removing the label 10 from the article or covering the label with a protection or asynchrony device, such as a metallized decal. Other methods include exposing label 10 to predetermined energy levels to cause the creation of an open circuit or short circuit within label 10, usually through the use of a weak link or depression in the designated conductive pattern for change electrical characteristics in a predictable manner at the time of exposure to sufficient energy. The present invention provides other means for deactivating the resonance circuit 11 'of the label 10' by including a non-conductive space 22 in at least one of the conductive patterns 18 ', 20' (not shown) to form an electrical open circuit, as shown in Figures 3-6, where the main designations refer to main parts; of the present embodiment and the prior art and the alternative methods of constructing the label 10 of the prior art apply in the same way to the present embodiment. Those skilled in the art will understand that the term "open circuit" implies an electrical circuit condition wherein: 1) the "Q" of the resonance circuit 11 'has sufficient reduction so that the resonance circuit 11' does not break the field RF produced by an electronic item surveillance system sufficient to detect it, or 2) the resonance frequency of the resonance circuit 11 'is outside a predetermined detection scale of an electronic article surveillance system, or 3) the resonance circuit 11 'does not resonate. In the present embodiment, the space 22 is formed in the inductive coil 26 'at the time of forming the first conductive pattern 18' using the "flat circuit fabrication method" described above. Alternatively, the space 22 can be formed by removing a portion of the conductive pattern 18 'after forming it, by selective etching, or by cutting, or otherwise removing a portion of the already formed conductive pattern 18' with an instrument. sharp and removing a section of the material. Those skilled in the art understand that other techniques or methods may be employed to form the space 22 in order to form an open circuit within the spirit and scope of the invention. In addition, the space 22 could be formed in any portion of the conductive pattern 18 ', such as between the inductive coil 26' and the rectangular planar portion 28 ', and multiple spaces 22 could be formed in the inductive patterns 18', 20 ' within the spirit and scope of the invention. In the present embodiment, illustrated in Figures 5 and 6, a conductive composition 24 bridges the space 22 in the conductive pattern 18 'at least to temporarily establish an electrical closed-loop condition in the conductive pattern 18' that enables the resonance circuit 11 'to resonate by exposing it to RF energy at a frequency within a predetermined frequency scale. Those skilled in the art understand that the term "closed circuit" implies an electrical circuit condition that enables resonance circuit 11 'to resonate at a frequency within a predetermined frequency scale with high "Q" high enough for it to detect it. an electronic article surveillance system, when the label is within the surveillance zone. In the present embodiment, the resonance circuit Q is preferably in the range of 50-80, when space 22 bridges the conductive composition 24. However, those skilled in the art understand that the circuit Q may be greater or lesser than the preceding scale, depending on the electronic security system of articles with which the label 10 is designed to operate with it, and still remains within the spirit and scope of the invention. It is also understood that where there is a plurality of spaces 22, the conductive composition 24 is applied to each space 22 to establish a closed circuit and further that the specific composition of the conductive composition 24 may be different to be applied to each space 22 with the object of achieving a variety of label deactivation properties on the 10 'label. The conductive composition 24 is preferably formed by drying a liquid composition comprising a solution, suspension or dispersion of a matrix material in a solvent base in which conductive particles are dispersed or otherwise suspended. An aplícador can be used to apply the liquid composition 25 to the conductive pattern 18 '. The space 22 is preferably filled with the liquid composition 25 to bridge the space 22 in the conductive pattern 18 ', as illustrated in Figures 5-6. After the application of the liquid composition 25 to the conductive pattern 18 ', the solvent base of the liquid composition 25 is removed by drying, leaving the conductive composition 24 adhered to the conductive pattern 18 'and dielectric 12'. The conductive composition 24 is preferably dried by heating, but may be dried by evaporation at room temperature, through infrared rays or other suitable means within the spirit and scope of the invention. The first preferred embodiment of the conductive composition 24, sensitive to water after drying, comprises water as a solvent base, a water-soluble polyvinyl alcohol matrix material and conductive metal particles. A suitable and preferred polyvinyl alcohol is the polyvinyl alcohol available under the trademark Elvano ™ available from E.l. DuPont as part number 52-22. Preferably, the conductive particles are silver, and preferably have an approximate size below 10 microns. The preferred embodiment of the water-sensitive conductive composition 24 is first constituted by the formation of an aqueous solution of about 90% by weight of water and about 10% by weight of Elvano ™. In general, an amount of silver particles equal to the weight of the Elvanol ™ / water solution is added to the Elvanol ™ / water solution to form the liquid composition 25. Those skilled in the art will understand that the percentages and amounts of the constituents of the liquid composition can vary, so long as the conductive composition 24 has the ability to exhibit the desired conductive and physical properties. In forming the matrix material, the percentage of Elvano ™ ', preferably, ranges from about 1% to about 12% by weight of the Elvanol ™ / water solution. Further, in the formation of the conductive composition 24, the percentage of silver particles in the liquid composition 25, preferably, ranges from about 10% to about 70% of the liquid composition 25 by weight. In addition, those skilled in the art will understand from this description that the formulation of the conductive composition 24 is not limited to silver particles, Elvano ™ and water. Other suitable conductive particles include conductive metals, metal alloys, conductive polymers or carbon. Other suitable matrix materials include a wide variety of one or more polymers including homopolymers and copolymers of vinyl, acrylic, styrene, vinylpyrrolidone, cellulose polymers, as well as polylactic acid and polyglycolic acid and derivatives thereof. In addition, the solvent or suspension material in which the matrix material and metal is incorporated is not limited to a water solution, but may include other aqueous solutions or organic solvents. The conductive composition can also incorporate additives, such as fillers, pigments, silica, talc, binders, suspending agents, thixotropic agents and the like to adjust the viscosity of the liquid composition 25, sensitivity to solvents and flexion after evaporation, as required.

A second preferred embodiment of the dry conductive composition 24, sensitive to water and dry cleaning solution (almost always perchlorethylene) after drying comprises a water-soluble Elvano ™ solution, silver particles, water and polymethylvinyl ether. A suitable and preferred polymethylvinyl ether is the polymethylvinyl ether-sensitive perchlorethylene prepared by Aldrich Chemical Company as part number 18-272-9. The second preferred embodiment of the conductive composition 24 is first formed by the preparation of a first aqueous solution (A) of about 90% by weight of water and about 10% by weight of Elvano ™. An amount of a second aqueous solution (B) of about 50% by weight of polyvinyl vinyl ether and about 50% by weight of water is provided for the first aqueous solution, so that the weight of the second solution (B) is about of 24% by weight of the final combined solution (A) and (B). A quantity of silver particles in general equal to the weight of the final combined solution is then added to the final combined solution to form the liquid composition 25. It will be understood that it is not necessary that the percentages and amounts be precious, as explained above. , and may vary as long as the conductive composition 24 has the ability to exhibit the desired conductive and physical properties. The proportions of silver particles, polymethylvinyl ether and Elvanol ™ to the total weight of the conductive composition 24, preferably range from about 10% to 70% by weight of silver particles, from about 3% to 10% by weight of polymethylvinyl ether and around 2 to 10% by weight for Elvano- ™, where the water is the rest. In addition, those skilled in the art understand that conductive composition 24, sensitive to water and dry cleaning fluid, upon drying, is not limited to silver particles, Elvanol ™, polymethylvinyl ether and water, and that other conductive particles and materials The matrix can be used as already explained above in the spirit and scope of the invention. A third preferred embodiment of the conductive composition 24, frangible and not soluble in water or dry cleaning liquid after drying, comprises a water-based dispersion of polymeric particles and water (latex) and metal particles. The third preferred embodiment of the conductive composition 24 is constituted by mixing the water-based dispersion made under the trademark of Adcote ™ by Morton International Company (Part Number 37T77) with an amount of silver particles equal to about 60. % by weight of the total weight of the liquid composition 25. Those skilled in the art will understand that the proportion of silver particles to Adcote ™ need not be 60% accurate by weight of the liquid composition 25 and that the percentage of silver particles can vary according to the liquid composition 25, as long as the conductive composition 24 has the ability to exhibit the desired conductive and physical properties. The percentage of silver particles preferably varies from about 20% to about 70% for a preferred scale of effectiveness. In addition, it is understood that latex dispersion does not need to be consisted of specifically Adcote ™ and silver particles. Other similar water-based dispersions, such as those based on vinyl or acrylic polymers having suitable viscosity of liquid and frangibility when dried, and other conductive particles as explained above, may be employed within the spirit and scope of the invention. The present invention provides a means to deactivate the label 10 '. In this invention, the label 10 'can be deactivated by exposing the conductive composition 24 to a fluid for a predetermined time to make at least a portion of the conductive composition dissolve, dissipate or disintegrate, thereby causing dispersion of at least a portion of the conductive composition 24, which results in an electrical open circuit condition in circuit 11 'which prevents circuit 11' from resonating within the predetermined frequency scale. Alternatively, the label 10 'can be deactivated by exposing the label 10' to a mechanical force for a predetermined time to cause the label 10 'to flex and consequently cause at least a portion of the composition 24 to fracture or otherwise otherwise it dissipates or disperses, resulting in an electrical open-circuit condition in circuit 1", which prevents circuit 11 'from resonating within the predetermined frequency scale, although it is preferred that the characteristics of conductive composition 24 altered by dissolving the composition 24 with a fluid, or fracturing the composition 24 with mechanical force, those skilled in the art understand that the characteristics of the composition 24 can be altered by other physical or chemical changes to the composition 24 and also altered through of methods other than exposure to a fluid or mechanical force, which include heating and sonic, without to depart from the spirit and scope of the invention. For example, in use, the tag 10 'may be incorporated into a garment, such as a shirt dress at the point of manufacture and before the item is shipped to the retail outlet. Label 10 'would ordinarily be deactivated through any of the aforementioned prior art means at the time of selling the item in the retail store. However, it is possible that the tagged item could be sold through channels that do not provide normal deactivation. Alternatively, the label 10 'may not be deactivated appropriately at the point of sale. In any case, by using the dress or shirt, the conductive composition 24 would now provide an additional deactivation mechanism generally provided. For example, a label 10 'employing a soluble composition would dissolve to deactivate the label 10' upon exposure to a fluid, so that it could be found in normal washing of the dress or shirt, by cleaning in a cleaning solution in dry or through exposure to body perspiration. Similarly, the label 10 'employing a frangible composition 24 could be incorporated into an article, such as a garment, in a location where the garment exposes the label 10' to a sufficient mechanical force to fracture the composition. conductive 24 when using the article for a predetermined time. For example, a shoe worn during a period or a shirt or pants worn during a period would fracture the frangible conductive composition 24 and deactivate the label 10 '. In some embodiments of the label 10 ', the frangible conductive composition 2: 4 could be constituted so that the label 10' would retain its resonance properties after exposure to water or dry cleaning fluid for a predetermined time, as could be find yourself in a prewash of the garment before selling the items. One skilled in the art will recognize that the use of the label 10 'with a conductive composition 24 for deactivating the label 10' is not limited to the use in garments, and that the label 10 'can be used in other articles in which it is used. Desires the permanent deactivation without departing from the spirit and scope of the invention. The label 10 'is preferably assembled by the steps of: 1) laminating an electrically conductive sheet on at least one major surface of a dielectric substrate 12', 2) forming an electrical circuit 11 'from the conductive film electrically in the dielectric substrate 12 'which comprises at least one electrically conductive pattern 18', 20 ', 3) form a space 22 in the conductive pattern 18', 20 ', and 4) apply a liquid composition 25 to the label 10' with an applicator to bridge the space 22 in the conductive pattern 18 ', 20 ', to cause the circuit 11' to resonate when the liquid composition 25 is dried and when the label 10 'is exposed to the RF energy at a frequency within a predetermined frequency scale. The label 10 'is deactivated by reforming the space 22 in the conductive pattern, so that the circuit 11' no longer resonates at a frequency within the predetermined frequency scale. Those skilled in the art understand that other means of assembly may be employed, and that the order of the assembly steps may vary without departing from the spirit and scope of the invention. For example, space 22 can be formed at the same time that electric circuit 11 'is formed. Those skilled in the art will appreciate that changes can be made to the embodiments described above without departing from the broad concept of the invention. Therefore, it is understood that this invention is not limited to particular embodiments described, but is intended to encompass the modifications within the spirit and scope of the present invention, as defined by the appended claims.

Claims (30)

NOVELTY OF THE INVENTION CLAIMS

1. - A label comprising: a dielectric substrate having first and second opposing main surfaces; an electrical circuit comprising an electrically conductive pattern formed on at least one of the major surfaces of the dielectric substrate, wherein the conductive pattern includes a space that establishes an electric open circuit; and an electrically conductive composition that includes electroconductive particles that bridge the space in the conductive pattern to temporarily establish an electrical closed loop, wherein the electrical circuit resonates upon exposure to electromagnetic energy at a frequency within a predetermined frequency scale , wherein the electroconductive particles are dispersed in a polymeric matrix material.

2. The label according to claim 1, further characterized in that the electrical circuit includes an inductive element and the space is formed in a portion of the inductive element.

3. The label according to claim 2, further characterized in that the inductive element is a coil.

4. - The label according to claim 2, further characterized in that the inductive element is a transmission line.

5. The label according to claim 1, further characterized in that exposing the conductive composition to a durein fluid for a predetermined time causes at least a portion of the composition to partially dissipate, which results in a circuit condition. electrical open in the electrical circuit that prevents it from resonating within the predetermined frequency scale.

6. The label according to claim 5, further characterized in that the fluid is at least one of water and dry cleaning fluid.

7. The label according to claim 1, further characterized in that the electroconductive particles are selected from the group consisting of metals, metal alloys, conductive polymers and carbon.

8. The label according to claim 7, further characterized in that the electroconductive particles are metal, and the metal is; silver.

9. The label according to claim 1, further characterized in that the polymeric matrix material is selected from the group consisting of homopolymers and copolymers of vinyl monomers, acrylate monomers, styrene, lactic acid, glycolic acid, vinylpyrrolidone and materials of cellulose, and derivatives thereof.

10. The label according to claim 9, further characterized in that the polymeric matrix material comprises polyvinyl alcohol.

11. A method for making a label comprising the steps of: forming an electrical circuit in a dielectric substrate, the circuit comprising at least one electrically conductive pattern; form a space in the conductive pattern to establish an open circuit; applying a liquid composition to the conductive pattern to bridge the space, the liquid composition includes electro-conductive particles dispersed in a polymeric matrix material and a water-based dispersion; and drying the liquid composition to form an electrically conductive composition in the conductive pattern to cause the electrical circuit to resonate upon exposure to electromagnetic energy at a frequency within a predetermined frequency scale.

12. The method according to claim 11, further characterized in that the step to make the electric circuit form an inductive element and the space is formed in a portion of the inductive element.

13. The method according to claim 11, further characterized in that the step to form the space includes acid chemical attack of a portion of the conductive pattern.

14. - The method according to claim 11, further characterized in that the step to form the space includes cutting a portion of the conductive pattern.

15. The method according to claim 11, further characterized in that the step to form the space includes the formation of space at the same time that the electrical circuit is formed.

16. A method for deactivating a tag, comprising the steps of: forming an electrical circuit in a dielectric substrate, the circuit comprising at least one electrically conductive pattern; form a s in the conductive pattern to establish an open circuit; apply a liquid composition to the conductive pattern to bridge s; drying the liquid composition to form an electrically conductive composition in the conductive pattern to cause the electrical circuit to resonate upon exposure to electromagnetic energy at a frequency within a predetermined frequency scale; and restoring the s in the conductive pattern by exposing at least a portion of the conductive composition to a fluid for a predetermined time to make at least a portion of the conductive composition partially dissipate, which results in a condition of electric open circuit in the electric circuit to avoid that it resonates within the predetermined frequency scale.

17. A label comprising: a dielectric substrate having first and second opposing main surfaces; an electrical circuit comprising an electrically conductive pattern formed on at least one of the major surfaces of the dielectric substrate, the conductive pattern includes a s that establishes an electrical open circuit in the electrical circuit; and an electrically conductive composition that bridges the s in the conductive pattern that temporarily establishes an electrical closed circuit in the electrical circuit, such that the latter resonates upon exposure to electromagnetic energy at a frequency within a predetermined frequency scale, the composition is such that exposing it to a fluid for a predetermined time causes at least a portion of the composition to dissipate at least partially, which results in an electrical open circuit condition in the electrical circuit which prevents it from resonating within of the default frequency scale.

18. The label according to claim 17, further characterized in that the fluid is at least one of water and dry cleaning fluid.

19. A label comprising: a dielectric substrate having a first and a second major opposing surfaces; an electrical circuit comprising an electrically conductive pattern formed on at least one of the major surfaces of the dielectric substrate, wherein the conductive pattern includes a s that establishes an electrical open circuit; and an electrically conductive composition that includes electroconductive particles that bridge the s in the conductive pattern to temporarily establish an electrical closed loop, wherein the electrical circuit resonates upon exposure to electromagnetic energy at a frequency within a predetermined frequency scale , wherein exposing the label to a mechanical force for a predetermined time causes at least a portion of the composition to dissipate at least partially, which results in an electrical open circuit condition in the electrical circuit that prevents it from resonate within the predetermined frequency scale.

20. The label according to claim 19, further characterized in that the exposure of the conductive composition to at least one of water and dry cleaning solution for a given time does not cause the conductive composition to dissipate.

21. The label according to claim 19, further characterized in that the mechanical force is caused by bending the label.

22. A method for deactivating a tag, comprising the steps of: forming an electrical circuit in a dielectric substrate, the circuit comprising at least one electrically conductive pattern; form a s in the conductive pattern to establish an open circuit; apply a liquid composition to the conductive pattern to bridge s; drying the liquid composition to form an electrically conductive composition in the conductive pattern to cause the electrical circuit to resonate upon exposure to electromagnetic energy at a frequency within a predetermined frequency scale; and resetting the space by exposing the label to a mechanical force for a predetermined time to cause at least a portion of the conductive composition to dissipate at least partially, which results in an electrical open circuit condition in the electrical circuit to prevent it from resonating within the predetermined frequency scale.

23. The method according to claim 22, further characterized in that the step to expose the label to a mechanical force is carried out by flexing the label.

24. A label comprising: a dielectric substrate having first and second opposing main surfaces; an electrical circuit comprising an electrically conductive pattern formed on at least one of the main dielectric substrate surfaces, wherein the conductive pattern includes a space that establishes an electric open circuit; and an electrically conductive composition that includes electro-conductive particles dispersed in a water-based dispersion that bridges the space in the conductive pattern to temporarily establish an electrical closed circuit, whereby the electrical circuit resonates upon exposure to electromagnetic energy at a frequency within a predetermined frequency scale.

25. The label according to claim 24, further characterized in that the electric circuit includes an inductive element and the space is formed in a portion of the inductive element.

26. - The label according to claim 25, further characterized in that the inductive element includes a coil.

27. The label according to claim 25, further characterized in that the element includes a transmission line.

28. The label according to claim 24, further characterized in that exposing the label to a mechanical force for a predetermined time causes at least a portion of the composition to dissipate at least partially, which results in a condition of electric open circuit in the electric circuit that prevents it from resonating within the predetermined frequency scale.

29. The label according to claim 24, further characterized in that exposing the conductive composition to at least one of water and a dry cleaning solution for a predetermined time does not cause the conductive composition to dissipate.

30. A label comprising: a dielectric substrate having first and second surfaces; an electrical circuit comprising an electrically conductive pattern formed on at least one of the major surfaces of the dielectric substrate, wherein the conductive pattern includes a space that establishes an electrical open circuit; and an electrically conductive composition that includes electro-conductive particles that bridge the space in the conductive pattern to temporarily establish an electrical closed circuit therein, the electrical circuit resonates upon exposure to electromagnetic energy at a frequency within a frequency range predetermined time, wherein the exposure of the conductive composition to a mechanical force for a predetermined time causes at least one portion of the composition to dissipate at least partially, which results in an electrical open circuit condition in the electrical circuit that it prevents it from resonating within the predetermined frequency scale, and exposure of the conductive composition to at least one of water and a dry cleaning solution for a predetermined time does not cause the conductive pattern to dissipate.