CA1309847C - Tag and method of making same - Google Patents

Abstract

Docket No. M-501 Abstract of the Disclosure This invention relates to a deactivatable tag useable with an electronic article surveillance system and comprised of planar conductive material cut into a pair of inverse, first and second spiral conductors wrapped about each other and positioned for capacitive and inductive coupling. The invention also relates to method of making tags wherein conductors are cut from a planar web of conductive material in a continuous process in a manner that the cutting results in the formation of two spiral conductors without accompanying waste of conductive material, and thereafter positioning the conductors to provide resonant circuits. The conductors of each pair are connected by welding to provide a reliable circuit.

Description

1 ~09~47 Backqround of the Invention Field of the Invention This invention relates to the art of resonant tags used in electronic article surveillance systems and to method of making such tags.
Brief Description of the Prior Art The following patents are made of record: UOS.
patent 3,240j647 to Morgan grantea March lS, 1966; U.S.
patent 3,624,631 to Chomet granted November 30, 1971; U.S.
patent 3,810,147 to Lichtblau granted May 7, 1974; U.S.
patent 3,913,219 to Lichtblau granted October 21, 1975; U.S.

1 3nq~7 Docket No. M-501 -2-patent 4,369,557 to Vandebult granted January 25, 1983; U.S.
patent 4,482,874 to Rubertus et al granted November 13, 1984;
U.S. patent 4,541,559 to O'Brien granted September 17, 1985;
U.S. patent 4,555,414 to Hoover granted November 26, 1985;
U.S. patent 4,555,291 to Tait et al granted November 26, l9B5; U.S. patent 4,567,473 to Lichtblau granted January 28, 1986; and French patent 2,412,923 to Degueldre.
Summary of the Invention This invention relates to im~roved, reliable methods of making tags for use in an electronic article surveillance system. This invention also relates to improved tags for use in such systems.
It is a feature of the invention to provide an improved method of making such tags which typically include a pair of conductors spaced by dielectric material. The connectors, both of which are preferably spiral, are locally welded to each other and, as thus connected, provide a detectable resonant circuit. It is preferred that the conductors are both inductively coupled and that there is distributed capacitance between the conductors. It is also preferred that the place or places where the spiral conductors are welded be free of any dielectric, adhesive or other materials that could hinder the formation of a good weld. It is also preerred that the welding be performed at a temperature and/or at a location which would not adversely affect either the resonant circuit or the means for deactivating the resonant circuit.
It is a feature of the invention to provide improved methods of making tags with detectable resonant circuits economically on a mass production basis, wherein conductors used in making each circuit are connected by welding to provide a reliable connection.
It is another feature of the invention to make tags with resonant circuits using connected conductors, in which the conductors are connected without the need for staking.

- Docket No. M-501 3- 1 3 [)9 ~ ~ 7 It is also a feature of the invention to provide an electronic article surveillance tag with a resonant circuit of improved reliahility. The resonant circuit is made by welding portions of two conductors to each other. The welding is performed by heating welding matexial dispersed between adjacent connector portions of the connectors.
Alternatively, the connector portions can be heated and fused locally as by a laser beam or other suitable contact or non-contact heater.
Brief Description of the Drawinqs FIGURE 1 is an exploded perspective view of a tag in accordance with an embodiment of the invention;
FIGURE 2 is a fragmentary sectional view of the tag shown in FIGURE l;
FIGU~E 3 is a diagrammatic perspective view illustrating method of making a tag in accordance with the invention;
FIGURE 4 iS a diagrammatic top plan view showing a mask having been applied to a first adhesive coated web and showing an electrically conductive web being laminated to the masked first adhesive coated web;
FIGURE 5 is a diagrammatic top plan view showing the conductive web having been cut to provide first and second pairs of conductors and showing a masked second adhesive coated web being laminated to the conductive web;
FIGURE 6 is a diagrammatic top plan view showing the first coated web with the first conductors adhered thereto being separated relatiYe to the second coated web with the second conductors adhered thereto, and showing further the first coated web having been recoated with adhesive and two webs of dielectric being laminated to the recoated first coated web, and showing the dialectric webs having been coated with adhesive;
FIGURE 7 is a diagrammatic top plan view showing the second coated web with the second conductors adhered thereto having been shifted and laminated over and to the dialectric Docket No. M-501 -4~ 9 ~ 4 7 webs and to the first coated web with the first conductors to provide a composite tag web, showing the staking of the first and second conductors of each tag to provide resonant circuits for each tag, and showing slitting of the composite tag web to provide a plural series of composite tag webs;
FIGURE 8 is a vertically exploded view showing the Eirst and second coated webs with the Eirst and second conductors that result from cutting the electrically conductive web spirally;
FIGURE 9 is a top plan view showing the first and second coated webs shifted by a distance e~ual to the width of one conductor spiral plus the width of one conductor;
FIGURE 10 is a top plan view of two tags with the dialectric web shown in phantom lines;
FIGURE 11 is a fragmentary perspective view which, when taken together with the preceding figures of the drawings, illustrates an improved method of making deactivatable tags;
FIGURE 12 is a Cragmentary top plan view taken along line 12--12 of FIGURE 11;
FIGURE 13 is a sectional view taken along line 13 -13 of FIGURE 12;
FIGURE 14 is a fragmentary perspective view similar to FIGURE 1, but showing one embodiment of structure for deactivating the tag;
; FIGURE 15 i5 a fragmentary top plan view of the tag shown in FIGURE 14;
FIGURE 16 is a fragmentary perspective view which, taken together with FIGURES 1 through 10, illustrated an alternative improved method of making deactivatable tags;
FIGURE 17 is a fragmentary top plan view taken along line 17--17 of FIGURE 16;
FIGURE 18 is a sectional view taken along line 18--18 of FIGURE 17;

. ....

Docket No. M-501 -5- 1 ~ 0 9 ~3 ~ 7 FIGURE 19 is a fragmentary perspective view similar to FIGURE 14 but showing another embodiment of structure for deactivating the tag;
FIGURE 20 iS a fragmentary top plan view of the tag shown in FIGVRE 19;
FIGURE 21 is a sectional view similar to FIGURE 18 but showing an alternative structure for deactivating the tag;
FIGURE 22 is a top plan view of an alternative cut pattern for the web of conductive material corresponding generally to D in FIGURE 5;
FIGURE 23 is a top plan view of the alternative cut pattern with one-half of the conductive material removed and corresponding generally to G in FIGURE 6;
FIGURE 24 is a diagrammatic perspective view showing the manner in which the webs of deactivating material are cut into stripes or strips;
FIGURE 25 is a top plan view of a pair of longitudinally spaced resonant circuits with separate respective deactivator strips;
FIGURE 26 is a fragmentary, diagrammatic, perspective view showing the portion of a tag making process which incorporates the present invention;
FIGURE 27 iS a top plan view similar to FIGURE 25, but incorporating the invention also illustrated in FIGURE
26;
FIGU~E 28 iS a sectional view taken generally along line 28--28 of FIGVRE 27;
FIGURE 29 is a fragmentary perspective view showing an alternative arrangement for welding the spiral conductors to each other; and FI5URE 30 is a sectional view taken generally along 30--30 of FIGURE 29.
Description of the Preferred Embodiments Referring initially to FIGURE 1, there is shown an exploded view of a tag generally indicated at 19~ The tag 19 .

Docket No. M-501 ~ 3 0 q 8 4 7 is shown to include a sheet 20T having pressure sensitive adhesive 21 and 22 on opposite faces thereof. A mask 23 in a spiral pattern covers a portion of the adhesive 21 and a release sheet 24T i5 releasably adhered to the adhesive 22.
The mask 23 renders the adhesive 21 which it covers non-tacky or substantially so. A conductor spiral indicated generally at 25 includes a spiral conductor 26 having a number of turns. The conductor 26 is of ~ubstantially the same width throughout its length except for a connector bar 27 at the outer end portion of the conductor spiral 26. There is a sheet of dielectric 28T over and adhered to the conductor spiral 25 and the underlying sheet 20T by means of adhesive 29. A conductor spiral generally indicated at 30 includes a spiral conductor 31 having a number of turns. The conductor 31 is adhered to adhesive 29 on the dielectric 28T. The conductor 31 is substantially the same width throughout its length except Eor a connector bar 32 at the outer end portion of the conductor spiral 30. The conductor spirals 25 and 30 are generally aligned in face-to-face relationship except for portions 33 which are not face-to-face with the conductor 26 and except for portions 35 which are not face-to-face with the conductor 31. A sheet 37T has a coating of a pressure sensitive adhesive 38 masked off in a spiral pattern 39. The exposed adhesive 38l is aligned with the conductor spiral 30.
Adhesive is shown in FIGURE 1 by heavy stippling and the masking is shown in FIGURE 1 by light stippling with cross-hatching. The connector bars 27 and 32 are electrically connected, as for example by staking 90~ It should be noted that the staking gn occurs where connector bars 27 and 32 are separated only by adhesive 29. There is no paper, film or the like between the connector bars 27 and 32. Accordingly, the staking disclosed in the present application is reliable.
With reference to FIGURE 3, there is shown diagrammatically a method or making the tag 19 shown in FIGURES 1 and 2. A roll 40 is shown to be comprised of a 1 3~)9('~7 Docket No. M-501 - 7-composite web 41 having a web 20 with a full-gum or continuous coatings of pressure sensitive adhesive 21 and 22 on opposite faces thereof. The web 20 is "double-faced" with adhesive. A release liner or web 42 is releasably adhered to the upper side of the web 20 by the pressure sensitive adhesive 21, and the underside of the web 20 has a release liner or web 24 releasably adhered to the pressure sensitive adhesive 22. As shown, the release liner 42 is delaminated from the web 20 to expose the adhesive 21. The adhesive coated web 20 together with the release liner 24 pass partially about a sandpaper roll 43 and between a pattern roll 44 and a back-up roll 45 where mask pattern~ 23 are applied onto the adhesive 21 to provide longitudinally recurring adhesive patterns 21'. Masking material from a fountain 46 is applied to the pattern roll 44. With reference to FIGURE 4, the portion marked A represents the portion of the web 20 immediately upstream of the pattern roll 44. The portion marked B shows the mask patterns 23 printed by the roll 44. The patterns 23 are represented by cross-hatching in FIGURE 4. With reference to FIGURE 3, the web 20 now passes through a dryer 47 where the mask patterns 23 are dried or cured. The adhesive 21 is rendered non-tacky at the mask patterns 23. A web 49 of planar, electrically conductive material such as copper or aluminum xom a roll 48 is laminated onto the coated web 20 as they pass between laminating rolls 50 and 50'. Reference character C in FIGURE
4 denotes the line where l~mination of the webs 20 and 49 occurs. With reference to FIGURE 3, the laminated webs 20 and 49 now pass between a cutting roll 51 having cutting blades 52 and a back-up roll 5~ The blades 52 cut completely through the conductive material web 49 but preferably do not cut into the web 20, The blades 52 cut the web 49 into a plurality of series of patterns 25 and 30 best shown in the portion marked D in FIGURE 5. With reerence again to FIGURE 3, there is shown a roll 54 comprised of a co~posite web 55 having a web 37 with a full-~um or 1 ~()')~47 Docket No. M-501 -8-continuous coating of pressure sensitive adhesive 38 and a release liner 56 releasably adhered to the adhesive 38 on the web 37~ The release liner 56 is separated from the web 37 and the web 37 passes about a sandpaper roll 57. From there the web 37 passes between a pattern roll 58 and a back-up roll 59 where mask patterns 39 are applied onto the adhesive 38 to render the adhesive 38 non-tacky at the mask patterns 39 to provide longitudinally recurring adhesive patterns 38' (FIGURE 1). Masking material from a fountain 60 is applied to the pattern roll 58. The masking material of which the patterns 23 and 39 are comprised is a commercially available printable adhesive deadener such as sold under the name "Aqua Superadhesive Deadener by Environmental Inks and Coating Corp, Morganton, North Carolina~ From there the web 37 passes partially about a roll 61 and through A dryer 62 where the mask patterns 39 are dried or cured. The adhesive 38 is rendered non-tacky at the mask patterns 39. From there the webs 20, 49 and 37 pass between laminating rolls 63 and 64.
FIGURE 5 shows that lamination occurs along line E where the web 37 meets the web 49. When thus laminated, each adhesive pattern 21' registers only with an overlying conductor spiral 25 and each adhesive pattern 38' registers only with an underlying conductor spiral 30.
The webs 20, 37 and 49 pass successively partially about rolls 65 and 66 and from there the web 37 delaminates from the web 20 and passes partially about a roll 67. Ak the place of delamination, the web 49 separates into two webs of conductor spirals 25 and 30. As shown in FIGURE 6, delamination occurs along the line marked F. When delamination occurs, the conductor spirals 30 adhere to the adhesive patterns 38' on the web 37, and the conductor spirals 25 adhere to the adhesive patterns 21' on the web 20.
Thus, the conductor spirals 30 extend in one web and the spirals 25 extend in another web. The web 20 passes partially about rolls 68, 69 and 70 and from there pass between an adhesive coating roll 71 and a back-up roll 72.

Docket No. M-501 -9- 1 3 ~ 9 ~ 4 7 Adhesive 29 from a fountain 73 is applied to the roll 71 which in turn applies a uniform or continuous coating of adhesive 29 to the web 20 and over conductive spirals 25.
The portion marked G in FIGURE 6 shows the portion of the web 20 and conductor spirals 25 between the spaced rolls 66 and 72. The portion marked H shows the portion of the web 20 between the spaced rolls 72 and 74. With reference to FIGURE
3, the web 20 passes through a dryer 75 where the adhesive 29 is dried. A plurality, specifically two laterally spaced dialectric webs 28a and 28b wound in rolls 76 and 77 are laminated to the web 20 as the webs 20, 28a and 28b pass between the rolls 74 and 74'. This laminating occurs along reference line I indicated in FIGURE 6. With reference to FIGURE 3, the web 20 with the conductor spirals 25 and the dialectric webs 28a and 28b pass about rolls 78 and 79 and pass between an adhesive applicator roll 80 and a back-up roll 81. The roll 80 applies adhesive 29' received from a fountain 83 to the webs 28a and 28b and to the portions of the web 20 not covered thereby. From there, the webs 20, 28a and 28b pass through a dryer 84 and partially about a roll 85.
The web 37 which had been separat~d from the web 20 is laminated at the nip of laminating rolls 86 and 87 along a line marked J in FIGURE 7 to provide a composite tag web generally indicated at 88. The w~bs 20, 28a, 28b and 37 are laminated between rolls 86 and 87 after the conductor spirals 30 have been shifted longitudinally with respect to the conductor spirals 25 so that each conductor spiral 30 is aligned or registered with an underlying conductor spiral 25.
The shifting can be equal to the pitch of one conductor spiral pattern as indicated at p (FIGURE 9) plu5 the width w of one conductor, or by odd multiples of the pitch p plus the width w of one conductor. Thus, each pair of conductor spirals 25 and 30 is capable of making a resonant circuit detectable by an appropriate article surveillance cirruit.

3 ~
Docket NoO M-501 -lO-FIGURE 8 shows the web 20 and the web 37 rotated apart by 180. FIGURE 9 shows the web 20 and the web 37 rotated ap~rt by 180 and as having been shifted with respect to each other 50 that the conductor spirals 25 and 30 are aligned. As best shown in FIGU~E 10, the dialectric 28a terminates short of stakes 90 resulting from the staking operation. By this arrangement the stakes 90 do not pass through the dielectric 28a (or 28b). FIGURE 10 shows the conductor spirals 25 and 30 substantially entirely vverlapped or aligned with each other, except as indicated at 35 for the conductor spiral 25 and as indicated at 33 for the conductor spiral 30. Each circuit is completed by staking the conductor bars 27 and 32 to each other as indicated at 90 or by other suitable means. The staking 90 is performed by four spiked wheels 89 which make four stake lines 90 in the composite web 88. The spiked wheels 89 pierce through the conductor bars 27 and 32 and thus bring the conductor bars 27 and 32 into electrically coupled r~lationship. The web composite 88 is slit into a plurality of narrow webs 91 and 92 by slitter knife 93 and excess material 94 is trimmed by slitter knives 95. The webs 91 and 92 are next cut through up to but not into the release liner 24 by knives on a cutter roll 96, unless it is desired to cut the tags T into separated tags in which event the web 88 is completely severed transversely. As shown, the webs 91 and 92 continue on and pass about respective rolls 97 and 98 and are wound into xolls 99 and 100. As shown in FIGURE 7, the staking 90 takes place along a line marked R and the slitting *akes place along a line markea L.
The sheet 37T, the dialectric 28T, the sheet 20T and the sheet 24T are respectively provided by cutting the web 37, the web 28a (or 28b), the web 20 and the web 24.
FIGU~E 11 is essentially a duplicate of a portion of FIGURE 3, but a pair of coating and drying stations generally indicated at 111 and 112 where respective coatings 113 and 114 in the form of continuous stripes are printed and dried.

1 3"~7 Docket No. M-501 -11-The coating 113 is conductive and is applied directly onto the pressure sensitive adhesive 38 on the web 37. The coatings 114 are wider than the respective coatings 113 which they cover to assure electrical isolation, as best shown in FIG~RES 12 and 13. The coatings 114 are composed of a normally non-conductive activatable material. The remainder of the process is the same as the process taught in connection with FIGURES 1 through 10.
With reference to FIGURES 14 and 15, there is shown a fragment of the finished tag 37T' with the coatings 113 and 114 having been severed as the tag 37T' is severed from the tag web as indicated at 113T and 114T respectively. As shown the coating 113T is of constant width and thickness throughout its length and the coating 114T is of constant width and thickness but is wider than the coating 113T. The coating 113T which is conductive is thus electrically isolated from the conductor spiral 30. The coatings 113T and 114T comprise an activatable connection AC which can be activated by subjecting the tag to a hiyh level of energy above that for causing the resonant circuit to be detected at an interrogation ~one.
FIGURE 16 is essentially a duplicate of a portion of FIGURE 3, but a pair of webs 118 and 119 are adhered to the adhesive 38 on the web 37. The webs 118 and 119 are wound onto spaced reels 120 and 121. The webs 118 and 119 pass from the reels 120 and 121 partially about a roll 122. The webs 118 and 119 are spaced apart from each other and from the side edges of the web 37. The webs 118 and 119 are identical in construction, and each includes a thin layer of conductive material 123 such as copper or aluminum on a layer of paper 123', a high temperature, normally non-conductive, activatable, conductor-containing layer 124, and a low temperature, normally non-conductive, activatable, conductor-containing layer 125. The layers 124 and 125 contain conductors such as metal particles or encapsulated carbon. The layer 125 bonds readily when heated, so a drum I ~()q~3~/
Docket No. M-501 -12-heater 115 is positioned downstream of the roll 67 (FIGURES 3 and 16) and upstream of the rolls 86 and 87 (FIGURE 3). The heated circuits 30, heat the layer 125 and a bond is formed between the circuits 30 and the layer 125. Rolls 116 and 117 (FIGURE 16) guide the web 37 about the drum heater 115. The heating of the layer 125 has some tendency to break down the normally non-conductive nature of the layer 125, but this is not serious because the layer 124 is not broken down or activated by heat from the drum heater 115.
With reference to FIGURES 19 and 20, there is shown a fragment of a finished tag 37T" with the webs 118 and 119 having been severed so as to be coextensive with the tag 37T"
and is indicated at 118T. The web strip or stripe 118T
includes the paper layer 123', the conductive layer or conductor 123 and the normally non-conductive layers 124 and 125. The layers 123, 124 and 125 are shown to be of the same w.idth and comprise an activatable connection AC. Both coatings 124 and 125 electrically i~olate the conductor 123 form the conductor spiral 30. In other respects the tag 37T"
i5 identical to the tag 37T and is made by the same process as depicted for example in FIGURE 3.
The embodiment of FIGURE 21 is identical to the embodiment of FIGURES 16 through 20 except that instead of the webs 118 and 119 there are a pair of webs comprised of flat bands, one of which is shown in FIGURE 21 and is depicted at 118'. The band 118' is comprised of a web or band conductor 126 of a conductive material such as copper enclosed in a thin coating of a non-conductive material 127.
The band 118' comprises an activatable connection AC. As seen in FIGURE 21, the upper surface of the coating 127 electrically isolates the conductor 126 from the conductor spiral 30. The band 118' is processed according to one specific embodiment, by starting with coated motor winding wire, Specification No. 8046 obtained from the Belden Company, Geneva, Illinois 60134 U.S.A. and having a diameter oE about 0.004 inch with an insulating coating of about -~ Docket No. M-501 -13- 1 3 0 9 ~ ~ 7 0.0005, flattening the wire between a pair of rolls into a thin band having a thicknes~ of 0.0006 inch. Thus processed, the insulating coating is weakened to a degree which breaks down when the resulting tag is subjected to a sufficiently high energy level signal. The coating 118' is thus termed a "breakdown coating" because it acts as an insulator when the tag is subjected to an interrogation signal at a first energy level but no longer acts as an electrical insulator when subjected to a sufficently higher energy level signal. The conductor 126 accordingly acts to short out the inductor 30 at the higher energy level signal.
The embodiments depicted in FIGURES 11 through 20 and described in connection therewith enable the tag 37T' or 37T"
to be ~etected in an interrogation zone when subjected to a radio frequency signal at or near the resonant frequency of the resonant circuit. By sufficiently increasing the energy level of the signal, the normally non-conductive coating 114 lor 114T), or 124 and 125 becomes conductive to alter the response of the resonant circuit. This is accomplished in a specific embodiment by using a normally non-conductive coating to provide an open short-circuit between different portions of the conductor spiral 30.
When the tag is subjected to a high level of energy, in the embodiments of FIG~ES 11 through 15, and 16 through 20 the normally non conductive coating becomes conductive and shorts out the inductor. Thus, the resonant circuit is no longer able to resonate at the proper frequency and is unable to be detected by the receiver in the interrogation ~one.
While the illustrated embodiments disclose the activatable connection AC provided by an additional conductor as extending across all the turns of the conductor spiral 30 and by a normally non-conductive material or breakdown insulation electrically isolating the conductor from the conductor ~piral 30 and also e~tending across all of the turns of the conductor ~piral 30, the invention is not to be considered limited thereby.

1 309~7 Docket No. M-501 -~4-By way of example, not limitation, examples of the various coatings are stated below:
I. For the embodiment of FIGURES ll through 15 A. Examples of the normally non-conductive coating 114 are:
Example 1Parts by Weiqht cellulose acetate (C.A.) powder (E-398-3) 60 acetone 300 Mixing procedure: Solvate C.A. powder in acetone with stirring.
C.A./copper dispersion above C.A. solution (16~T.S.) 15 copper 8620 powder 2.5 Mixing procedure: Add copper powder to C.A. solution with adequate stirring to efEect a smooth metallic dispersion.
Example 2 acrylvid B-48N
~45~ in toluene~ 30 acetone 20 isopropanol 3 Above solution (25%T.S.) lO
copper 8620 powder 5 Mixing procedure: disperse copper powder into B-48N solution (Percent copp~r powder is 60-70% on dry weight basis.) B. Examples of the conductive coating 113 are:
Example l Parts by_~eight acryloid B-67 acrylic t45% in naptha) 25 naptha 16 silflake #237 metal powder 42 Mixing procedure: add metal powder to solvent and wet out. Add solvated acrylic and stir well to disperse. Mix or shake 1 3 ~ 7 ,,.,~ .
Docket No. M-501 -15-well prior to use~ (75% to 85~ conductive metal on dry weight basis.) Example 2 acryloid NAD-10 (4~ in naptha) 10 ; silflake ~237 metal powder 20 Mixing procedure: Add metal powder to acrylic dispersion with stirring.
Example 3 S & V aqueous foil ink OFG 11525 (37~T.S.) 5 silflake #237 metal powder Mixing procedure: Add metal powder to aqueous dispersion slowly with adequate agitation to effect a smooth metallic dispersion.
I. For the embodiment of FIGURES 16 throuqh 20 A. Examples of the low temperature coating 125 are:
Example 1 Parts by Weiqht acryloid NAD-10 dispersion ~30% T. Solids) 10 naptha 2 copper 8620 copper powder 5 Mixing procedure: wet copper powder with Naptha and disperse completely. ~dd NAD-10 dispersion slowly with stirringO Mix well or shake before useO
Example 2 polyester resin ~K-1979) 28 ethanol 10 isopropanol 10 ethyl acetate 20 ~bove polyester solution 10 copper 8620 powder 2.5 1 30q~7 . .
Docket No. M-501 -r 6-Mixing procedure: add copper powder to polyester solution while stirring to effect a smooth metallic dispersion.
~48% copper powder on dry basis) B. Examples of the high temperature coating 124 are:
Example 1 cellulose acetate butyrate tC.A.B.)(551-0.2) 40 toluene 115 Ethyl Alcohol 21 Above C.A.B. solution (22.7%) 10 toluene 2 copper 8620 copper powder 5 Mixing procedure: wet copper powder with solvent and add C.A.B. solution with stirring.
Example 2 acryloid B-48N
(~5% in toluene) 30 acetone 20 isopropanol 3 Above solution (25%T.S.) 10 copper 8620 copper powder 5 (Dry weight basis -- copper is 60-70%) Mixing procedure: add copper powder to above solution with proper agitation to effect a smooth metallic dispersion.
The materials used in the above examples are obtainable from the following suppliers-Acryloid NAD-10, Acryloid B-48N and Acryloid B-67, Rohm & ~ass, Philadelphia, Pennsylvania;

1 309g47 Docket No. M-501 -17-Cellulose Acetate (E-398-3) and Cellulose Acetate sutyrate (551-0.2), Eastman Chemical Products, Inc., Kingsport, TennesseP;
Copper 8620, U.S. Bronze, Flemington, New Jersey;
Silflake ~237, Handy & Harmon, Fairfield, Connecticut;
Krumbhaar K-1979, Lawter International, Inc., Northbrook, Illinois;
Aqeuous foil ink OFG 11525, Sinclair ~ Valentine~ St.
Paul, Minnesota.
FIGURES 22 through 25 depict an improved method over the embodiment of FIGURES 11 through 15, over the embodiment of FIGURES 16 through 20, and over the embodiment of FIGURE
21. The method of the embodiment of FIGURES 22 through 25 relates to the formation of longitudinally spaced deactivatable resonant circuits arranged in a web. The longitudinal spacing of the resonant circuits assures that electrostatic charge that can prematurely deactivate one resonant circuit in the web cannot arc longitudinally to the other resonant circuits in the web to cause their premature deactivation. Where possible r the same reference character will be used in the embodiment of FIGURES 22 through 25 as in the embodiment of FIGURES 16 through 20 to designate components having the same general construction and function, but increased by 200. It will be appreciated that reEerence is also made to FIGURES 3, 5 and 6.
; With reference initially to FIGURE 22, web 249 of planar, electrically conductive material is cut in patterns of conductor spirals 400 and 401. The cut patterns include lateral or transverse lines of complete severing 402. The conductor spirals 400 and 401 are generally similar to tha conductor spirals 25 and 30, however 3 inspection of FIGURE 5 will indicate that all conductor spirals 25 and 30 are in very close proximity to each other .Ln the longitudinal direction, being spaced only by knife cuts themselves. In addition, spirals 25 are connected to each other and spirals .

~ 3(~9~347 Docket No. M-501 -18-30 are connected to each other. In contrast, in the embodiment of FIGURES 22 through 25, only the conductor spirals 400 and 401 between adjacent lines of complete severing 402 are connected to each other. In the method of FIGURES 22 through 25, reference may be had to FIGURE 3 which shows that the conductor spiral webs 20 and 37 are separated as they pass partly about roll 66, thereafter dielectric material webs 28a and 28b are applied, the webs 20 and 37 are shifted longitudinally by the pitch of one conductor spiral 400 (or 401) plus the width of one conductor, and thereafter the webs 20 and 37 are re-laminated as they pass between rolls 86 and 87.
As is evident from FIGURE 23, once the web of resonant circuits 401 is stripped away, the resultant web 220 has pairs of resonant circuits 401 that are longitudinally spaced apart. In like manner, the pairs of resonant circuits 400 in the stripped away web (corresponding to the web 37 in FIGURE 3), are also spaced apart longitudinally.
The method of the embodiment oE FIGURES 22 through 25, relates to production of deactivatable tags. The illustrated arrangement for deactivating the tags utilizes the arrangement taught in the embodiment of FIGURES 16 through 20 with the exception that the deactivator webs 318 and 319 (corresponding to the deactivator webs 118 and 119 in FIGURE 16 fox example), are separated into longitudinally spaced deactivator strips or stripes 318' and 319'. The separation is accomplished in accordance with the specific embodiment shown in FIGURE 24, by punching out portions or holes 407 of the web 238 and the deactivator webs 318 and 319. For this purpose, a diagrammatically illustrated rotary punch 403 and a rotary die 404 are used. The rotary punch 403 has punches 405 and the rotary die 404 has cooperating die holes 406~ The resultant holes 407 are wider than the spacing between the xesonant circuits. The holes 407 are thus registered with the margins of the longitudinally spaced resonant circuits are shown in FIGURE 25. Thus, static --~~ Docket No. M-501 -19- 1 3 0 q ~ 4 7 electricity cannot arc between resonant circuits in a longitudinal direction and static electricity cannot arc between deactivator strips 318' (or 319l).
The invention of the embodiments of FIGURES 26 through 28, and 29 and 30 has applicability in general to tags with resonant circuits with generally spaced but connected conductors. For example, the invention is useful in the embodiments of FIGURES 1 through 10, 11 through 13, l4 through 20, 21 and 22 through 25. The invention i5 not limited to applications involving a pair of spiral conductors. It is useful for example in resonant circuits where at least one of the conductors is ~ot a spiral. This type of a circuit is shown for example in U.S. patent 3,913,219. The invention is, however, illustrated with the structure according to the most preferred embodiment of FIGURES 22 through 25.
~ ith reference initially to FIGURE 26, there are illustrated several of the steps in the improved process. It is to be understood that other steps in the process are illustrated in other figures, for example FIGURES 3 and 16.
It is seen in FI~URE 3 that the roll 71 applies a coating of adhesive 29 fully across the web 24 and that the roll 80 applies a coating of adhesive 29' fully across the dielectric webs 28a and 28b, but also fully across the exposed portions of the web 24. This means that when the staking occurs as illustrated at 90, the spiked wheels 89 are re~uired to pass through adhesive and also that the spiral conductors are spaced by that adhesive except where the staking w curs. By a construction not shown, and with respect to the embodiments of FIGURES 26 through 28, and 29 and 30, the roll 29 is patterned so it will not apply adhesive to the web 24 except in the path of the dielectric webs 28a and 28b. Roll 80' is identical to the roll 80 except it is patterned to apply adhesive 29' only to the upper sides of the dielectric webs 28a and 28b so that portions 24(1), 24(2) and 24~3) of the web 24 are free of adhesive. From there the web 24 and 1 309~7 Docket No. M-501 -20-associated webs 28a and 28b pass through a drier 84 and partly around a roll 85. A fountain 500 has a roll 501 cooperating with a back-up roll 502 to deposit or print a welding material 503 onto the connector portions 400c of spiral conductors 400 in a predetermined repetitive pattern.
It is preferred that two spaced spots of the welding material 503 be applied to each connector portion 400c. As shown, once the welding material 503 has been applied, the web 24 is laminated to the web 37 as they pass between rolls 504 and 505. From there the combined webs 24 and 37 pass partially around and in contact with a drum heater 506 and from there partially about rolls 507 and 508 to slitters 93 and 95.
From there the tag web 89 can be acted upon by transverse cutter 96 and the resulting narrow webs rolled into individual rolls. The drum heater 506 causes the connector portions 400c and 401c to be welded to each other to make good electrical connection. The expression "welding" as used herein includes what is sometimes referred to as "solderingn.
The heater 506 heats the welding material to the temperature where it fuses to the connector portions 400 and 401 to each other but below the temperature where the resonant circuit is degraded or where the activatable connection AC causes deactivation of the resonant circuit. By way o~ example, not limitation, the welding material fuses at 96C and the breakdown coating 114 for example breaks down at 103C. The welding material is comprised of 80~ by weight of metal alloy and of 20~ by weight of flux and is designated BI 52 PRMAA4 and sold by Multicore Solders Inc., Cantiague Rock Road, Westbury N.Y. 11590. The metal alloy contains 15~ tin, 33%
lead and 52~ bismuth. The 20~ by weight oE flux comprises 10.3~ resin 9 8.4% glycol, 0.3% activators and 1.0~ gelling agent.
In an alternative embodiment, the tags can be made as illustrated for example in FIGURES 3 and 16 except instead of applying the welding material 503, the connector portions 400C and 401C are connected by welding using localized heat to bring the temperature of the connector portions 400 and . Docket No. M-501 2l- . 1 3 098 4 7 401 to the melting point. The resulting weld is shown at 509. This can be accomplished for example by a laser beam.
Laser guns 510 illustrated in FIGURE 29 are operated to effect the welds 509.
Other embodiments and modifications of the invention will suggest themselves to those skilled in the art, and all such of these as come within the spirit of this invention are included within its scope as best defined by the appended claims.

.

Claims (4)

1. Method of making tags for use in an electronic article surveillance system, comprising the steps of providing a web having a series of first conductors, providing another web having a series of second conductors, positioning the webs so that the first and second conductors are in adjacent pairs and the first and second conductors of each pair are spaced apart by dielectric material, and using a laser beam to weld adjacent portions of the first and second conductors of each pair so that each pair provides a detectable resonant circuit.

2. Method of making tags for use in an electronic article surveillance system, comprising the steps of: providing a series of pairs of first and second conductors spaced apart by dielectric material, with each first and second conductor having a connector portion free of dielectric material, and using a laser beam to weld the connector portions of each pair of each other to provide a series of detectable resonant circuits.

3. Method of making tags for use in an electronic article surveillance system, comprising the steps of: providing a series of pairs of first and second conductors spaced apart by dielectric material and adhesively attached, with each first and second conductors having a connector portion free of dielectric material and free of adhesive, and welding the connector portions to each other to provide a series of detectable resonant circuits.

4. Method of making tags for use in an electronic article surveillance system, comprising the steps of providing a web having a series of first conductors, providing another web having a series of second conductors, wherein at least one of the conductors is a spiral conductor, depositing welding material on each conductor of one of said series, positioning a deactivator adjacent one conductor of one of said series, wherein the deactivator includes heat activatable material rendered conductive by the application of heat, positioning the webs so that the first and second conductors are in adjacent pairs spaced apart by dielectric material to provide a tag web, and applying heat to the tag web at a temperature high enough to cause the welding material to weld the conductors to each other to provide a detectable resonant circuit but low enough to prevent the activatable material from being rendered conductive.