SELECTIVELY ACTIVATABLE TIME TEMPERATURE INDICATORS

Abstract

A selectively activatable time-temperature indication (TTI) device, an article of manufacture comprising thereof and an activation method thereof. The TTI comprises a first element, a second element and a spacer configured to separate between the first element and the second element and is having a non-activated state and an activated state. TTI devices of this disclosure can be utilized to indicate the shelf life of a perishable good.

Claims

1. A time-temperature indication (TTI) device, comprising: a first element comprising a substrate film carrying a first reactant layer; a second element comprising a carrier film having at least one pressable section, said pressable section carrying a second reactant layer on at least a portion thereof, the second reactant layer configured to adhere to the first reactant layer; a spacer configured to separate between the first element and the second element, and having a hollow activation zone substantially aligned with said at least one pressable section; the device having a non-activated state, in which the first reactant layer and the second reactant layer are non-contacted, and an activated state, in which said second reactant layer is adhered to at least a portion of said first reactant layer to enable a reaction therebetween that causes at least one substantially irreversible change in physical property of the device, said reaction being indicative to time-temperature history of the device, the device being switchable from the non-activated state to the activated state by displacing the pressable section into the hollow activation zone towards said first element to cause adhering of the second reactant layer to the first reactant layer.

2. The TTI device of claim 1, wherein the pressable section is plastically deformable or elastically deformable.

3. (canceled)

4. The TTI of claim 1, wherein one or both of the first reactant layer and the second reactant layer is detachable from the substrate film and the carrier film, respectively, to permit detachment of said first reactant layer and/or second reactant layer from said substrate film and carrier film, respectively, after adherence of the second reactant layer to the first reactant layer.

5. The TTI device of claim 1, wherein the first reactant layer is detachable from the substrate film, such that adherence to the second reactant layer detaches at least a portion of the first reactant layer from the substrate film.

6. The TTI device of claim 1, wherein the first reactant layer is attached to the substrate film by a first adhesive and the second reactant layer comprises a second adhesive in which the second reactant is embedded or dispersed, the first adhesive having a lower adhesion strength to the substrate film than the adhesion strength of the second adhesive to the first reactant layer.

7. (canceled)

8. (canceled)

9. (canceled)

10. (canceled)

11. The TTI device of claim 1, wherein at least a portion of the first element is deformable or pressable, and said hollow activation zone is configured to accommodate displacement of at least a portion of the first reactant layer thereinto.

12. (canceled)

13. The TTI device of claim 1, wherein the first reactant layer-comprises a metal-containing sub-layer.

14. The TTI device of claim 13, wherein said metal-containing sub-layer is in the form of metal particles embedded in a polymeric matrix.

15. (canceled)

16. (canceled)

17. (canceled)

18. (canceled)

19. (canceled)

20. (canceled)

21. (canceled)

22. (canceled)

23. (canceled)

24. The TTI device of claim 1, wherein the pressable section of the carrier film is clear, transparent, or semi-transparent.

25. (canceled)

26. (canceled)

27. The TTI device of claim 1, wherein the carrier film is coated by a protective coating.

28. (canceled)

29. The TTI device of claim 1, encapsulated by one or more encapsulation layers.

30. The TTI device of claim 1, wherein said physical property is selected from at least one of color, transparency, electric conductivity, reflectance, volume and fluidity.

31. The TTI device of claim 1, wherein the first element is configured for attachment to a surface of an article.

32. (canceled)

33. (canceled)

34. (canceled)

35. (canceled)

36. (canceled)

37. An article of manufacture comprising one or more time-temperature indication (TTI) device of claim 1.

38. The article of claim 37, being a perishable good and/or a packaging of a perishable good.

39. A method of activating a time-temperature indication (TTI) device, the method comprising: displacing a pressable section of a carrier film of a second element of the TTI device towards a first reactant layer of a first element of the TTI device, the pressable section carrying a second reactant layer on at least a portion thereof which is configured to adhere to the first reactant layer, said displacing being through a hollow activation zone that is substantially aligned with said at least one pressable section and being defined in a spacer configured to separate between the first element and the second element, and said displacing causing adhering of the second reactant layer to the first reactant layer to activate a reaction therebetween, the reaction causing at least one substantially irreversible change in physical property of the device that is indicative to time-temperature history of the device.

40. The method of claim 39, further comprising displacing at least a portion of the first reactant layer into the hollow activation zone towards the second reactant layer.

41. The method of claim 40, wherein displacing said portion of the first reactant layer into the hollow activation zone is carried out concomitantly with pressing of the pressable section of the second element.

42. The method of claim 39, wherein one or both of the first reactant layer and the second reactant layer are detachable from the substrate film and the carrier film, respectively, to permit detachment of said first reactant layer and/or second reactant layer from said substrate film and carrier film, respectively, after adherence of the second reactant layer to the first reactant layer.

43. (canceled)

44. (canceled)

45. (canceled)

46. (canceled)

47. An indication device, comprising: a first element comprising a substrate film carrying a first reactant layer; a second element comprising a carrier film having at least one pressable section, said pressable section carrying a second reactant layer on at least a portion thereof, the second reactant layer configured to adhere to the first reactant layer; a spacer configured to separate between the first element and the second element, and having a hollow activation zone substantially aligned with said at least one pressable section; the device having a non-activated state, in which the first reactant layer and the second reactant layer are non-contacted, and an activated state, in which said second reactant layer is adhered to at least a portion of said first reactant layer to enable a reaction therebetween that causes at least one substantially irreversible change in physical property of the device, the device being switchable from the non-activated state to the activated state by displacing the pressable section into the hollow activation zone towards said first element to cause adhering of the second reactant layer to the first reactant layer, the reaction being indicative to time-temperature history, temperature history, or time history of the device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0084] 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:

[0085] FIGS. 1A-1C are schematic cross-sections of a TTI device according to an embodiment of this disclosure in a non-activated state (FIG. 1A), a transient position (FIG. 1B) and an activated state (FIG. 1C).

[0086] FIGS. 1D-1E are schematic cross-sections of variations of the TTI device according of FIGS. 1A-1C.

[0087] FIGS. 2A-2D are schematic top views of a TTI device according to an embodiment of this disclosure, as viewed by the user, at a non-activated state (FIG. 2A) and at various stages after activation (FIG. 2B-2C) until the device indicates that the perishable good is no longer usable (FIG. 2D).

[0088] FIGS. 3A-3D are schematic cross-sections of a TTI device according to a variation of the embodiment shown in FIGS. 1A-1C however also including a release layer between the second reactant layer and the carrier film—in a non-activated state (FIG. 3A), a transient position (FIG. 3B) and an activated state (FIGS. 3C-3D).

[0089] FIG. 3E is a schematic cross-sections of a variation of the TTI device according of FIGS. 3A-3D.

[0090] FIGS. 4A-4C are schematic cross-sections of a TTI device according to another embodiment of this disclosure in a non-activated state (FIG. 4A), a transient position (FIG. 4B) and an activated state (FIG. 4C).

[0091] FIGS. 5A-5C are schematic cross-sections of a TTI device according to a variation of the embodiment shown in FIGS. 4A-4C, however also including a release layer between the first reactant layer and the substrate film—in a non-activated state (FIG. 5A), a transient position (FIG. 5B) and an activated state (FIG. 5C).

[0092] FIGS. 6A-6B are schematic cross-sections of a TTI device according to another embodiment of this disclosure, with a plastically deformable pressable section, in a non-activated state (FIG. 6A) and an activated state (FIG. 6B).

[0093] FIGS. 7A-7B are schematic cross-sections of a TTI device according to another embodiment of this disclosure, in which both the first element and the second element have elastically deformable pressable sections, in a non-activated state (FIG. 7A) and an activated state (FIG. 7B).

[0094] FIGS. 8A-8B are schematic cross-sections of a TTI device according to another embodiment of this disclosure, similar to the embodiment of FIGS. 7A-7B, however also comprising a barrier membrane between the first and second elements—in a non-activated state (FIG. 8A) and an activated state (FIG. 8B).

[0095] FIGS. 9A-9B are schematic cross-sections of a TTI device according to another embodiment of this disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

[0096] In FIGS. 1A-4B, some representations of TTI devices according to this disclosure will be exemplified. It is to be understood that the various element of the devices are schematically represented and are not indicative of any specific scale or size.

[0097] Further, in the examples herein, the reaction between the first and second reactant layers (or first and second reactants) is a metal-etching mechanism. However, it is to be understood that these are merely provided for exemplifications of the principles of operation of the TTI devices described herein, and any other suitable type of reaction between the first and second reactants are encompassed by this disclosure.

[0098] Turning first to FIGS. 1A-1C, shown is a schematic representation of a TTI device according to an embodiment of this disclosure, at its non-activated and activated operational states.

[0099] TTI device 100 comprises a first element 102 and a second element 104, separated by a spacer 106. First element 102 comprises a substrate film 108, onto which a first reactant layer 112 is adhered by a first adhesive 110. In this exemplified embodiment, first reactant layer 112 is a metalized polymeric film comprising a polymeric film 114 coated by a thin metal (e.g. aluminum) film 116. Metal film 116 constitutes the first reactant of this embodiment. In order to permit the device to be attached to a perishable good or to an article of manufacture, substrate 108 is typically coated by package-attaching adhesive layer 118, which is covered by a user-removable protective release layer 120. For attaching the TTI device to the perishable good, a user needs to peel release layer 120 of the package-attaching adhesive layer 118, and attach the device to the perishable good or to a packaging thereof.

[0100] Second element 104 comprises carrier film 122 that has a pressable section 124 (the pressable section being an integral part of the carrier film), the function of which will be described below. The pressable section 124 is attached to a second reactant layer 126, which comprises or consists of a second reactant. In this specific example, the second reactant is a pressure-sensitive adhesive matrix in which an etchant is dispersed. In this example, the second reactant layer 126 is attached to the carrier film 122 by an intermediate adhesive 128.

[0101] The spacer 106 has a hollow activation zone 130 that is aligned with the pressable section 124, and is sized to permit the displacement of the second reactant layer 126 therein when the pressable section 124 is deformed for activation of the device 100, as will now be explained.

[0102] In FIG. 1A, the TTI device 100 is at its non-activated state, in which the first reactant layer 102 and the second reactant layer 104 are non-contacted and separated by spacer 106.

[0103] For activating the TTI device, a user applies force onto the pressable section 124 (represented by arrow 132 in FIG. 1B), thereby pressing (or elastically deforming) the pressable section and causing the second reactant layer 126 to be displaced through hollow activation zone 130 towards the first reactant layer 112. Once the second reactant layer 126 and the first reactant layer 112 are contacted, the second reactant layer 126 (being or comprising an adhesive matrix) adheres to metal film 116 of the first reactant layer 112.

[0104] In this example, the second reactant layer 126 has lower adhesion strength to intermediate adhesive 128 than to first reactant layer 112 (more specifically to the metal film 116). Hence, once second reactant layer 126 is adhered to metal film 116, and pressable section 124 returns to its non-pressed state (in the direction of arrow 134), or any intermediate state between the fully deformed and non-deformed states, due to its elasticity, second reactant layer detaches from the intermediate adhesive 128 and remains adhered to metal film 116, and the TTI device is activated.

[0105] By this simple mechanism, a user merely needs to slightly press on the pressable section 124 to cause displacement of the second reactant layer 126 until it adheres to metal layer 116 in order to activate the device.

[0106] The contacting between the second reactant layer 126 and the first reactant layer 112 causes the beginning of a reaction between the etchant in the second reactant layer and metal film 116. The reaction rate depends on time and temperature, and hence can be used to indicate the time-temperature behavior of the perishable good to which the device is attached. In order to provide an easily identified indication, the device is designed such that the reaction between the first and second reactants (e.g. between the metal and the etchant) causes at least one irreversible physical change in the device.

[0107] For example, one or both of the substrate film 108 and the polymeric film 114 can be colored or printed with any type of marking (e.g. lettering, pattern, signs, etc.). As metal film 116 is etched, it becomes thinner Below a certain threshold thickness, metal film 116 becomes transparent, thereby exposing the color or printing of substrate film 108 and/or the polymeric film 114. The pressable section 124 is transparent, semi-transparent or clear, and hence a user can view the appearance of color or printing in the device following etching of metal film 116—providing an indication to the user of the usability of the perishable good.

[0108] A variation of this embodiment is shown in FIG. 1D. In the variation of FIG. 1D, intermediate adhesive 128 is also used to adhere the second element 104 to the spacer. Further, carrier film 122 and substrate film 108 are extended, such that their ends can be attached together in order to form a protective capsule around the active zone of the device, thus isolating the device from environmental effects (such as moisture). Extended carrier and substrate films 122 and 108, respectively, can be attached at their ends by any suitable method, e.g. adhering, welding, hot lamination, ultrasonic welding, etc. For such purposes, carrier and substrate films 122 and 108 may be made of or be coated by a material suitable for the desired attachment method.

[0109] In the variation of FIG. 1E, spacer 106 is extended and can be made of a material that is suitable for hot lamination, welding, ultrasonic lamination, etc., such that sealing of the active zone of the device can be obtained between extended substrate 108 and spacer 106.

[0110] An exemplary TTI device at its various operational states is shown in FIGS. 2A-2D. In this example, the TTI device provides indication to the user about the time-temperature history of the perishable good by a visual observable change in the color of the active area of the TTI. Pressable section 124 is clear (or transparent) and therefore a user can view the change in color resulting from the advancement of the reaction between the first and second reactants (in this example between the etchant and the metal film). To permit accurate reading of the color, carrier layer 122 is printed with reference color blocks 136, such that the user can easily compare between the color developed beneath pressable section 124 and the reference colors 136, thus obtaining an indication of the usability of the perishable good. In this specific example, the color blocks 136 provide a graduated color index that matches the color development as a result of the reaction between the etchant and the metal. As can be seen, before activation (FIG. 2A), the color beneath pressable section 124 observable by the user is light. After activation, and depending on time and temperature, the color becomes darker (FIG. 2B-2C), until turning dark (FIG. 2D), indicating that the perishable good is no longer usable.

[0111] While in this specific example the physical change in the device is a color change from bright to dark, it is well understood that any other color change is encompassed by this disclosure (for example dark to bright, change of shade, change from one color to another, change in reflectance, appearance/disappearance of lettering, patterns, pictograms or signs, etc.).

[0112] Further, while in this example a plurality of reference color blocks is shown, it is to be understood that only a single-color block can be used. In some configurations, no reference color blocks are present and the change in color of the device may be identified without any comparison to a reference color.

[0113] A variant of the exemplary configuration of FIGS. 1A-1C is shown in FIGS. 3A-3C (elements having the same function as those in FIGS. 1A-1C are marked in FIGS. 3A-3C with a “′” marking; the reader is directed to the description of FIGS. 1A-1C for full understanding of the functionality of such elements). In FIGS. 3A-3C, second reactant layer 126′ is an active adhesive (i.e. an adhesive comprising or constituting the second reactant) and is associated with carrier film 122′ through a release layer 150. The release layer 150 is bonded to the carrier film 122′ by an adhesive 152. Release layer 150 comprises or is made of a material that binds to the second reactant layer 126′ less effectively than the binding of the second reactant layer 126′ to metal film 116′. Hence, due to the difference in binding, bringing the second reactant layer 126′ into contact with the metal film 116′ by elastically deforming section 124′ will cause the second reactant layer 126′ to adhere to metal film 116′, and detach from release layer 150, as seen in FIG. 3C.

[0114] In the variation of FIG. 3D, the adhesion strength of adhesive 152 to release layer 150 is lower than the adhesion strength of second reactant layer 126′ to metal film 116′. Hence, once second reactant layer 126′ is adhered to metal film 116′, it detaches, together with release layer 150 from adhesive 152.

[0115] In the variation of FIG. 3E, second reactant layer 126′ (which is constituted by an active adhesive) is carried by film 158, which is attached to release layer 150 via lamination adhesive 156.

[0116] Another example is provided in FIGS. 4A-4C. TTI device 200 comprises first element 202 and second element 204, which are separated by a spacer 206. Similar to the device of FIGS. 1A-1C, first element 202 comprises substrate film 108, onto which a first reactant layer 212 is adhered by a first adhesive 210. First reactant layer 212 is a metalized polymeric film comprising polymeric film 214 and thin metal (e.g. aluminum) film 216. Substrate 208 is coated by package-attaching adhesive layer 218, which is covered by a user-removable protective release layer 220 to permit attachment of the device to the perishable good or to a packaging thereof.

[0117] Second element 204 comprises carrier film 222 that has a pressable section 224, which is attached to second reactant layer 226 (for example a pressure-sensitive adhesive matrix in which an etchant is dispersed). In this example, the presence of intermediate adhesive 228 is optional.

[0118] In FIG. 4A, the TTI device 200 is at its non-activated state, in which the first reactant layer 202 and the second reactant layer 204 are non-contacted and separated by spacer 206.

[0119] Similar to the example of FIG. 1A, a user applies force onto the pressable section 224 (represented by arrow 232 in FIG. 4B), in order to activate the device. Due to this force application, pressable section 224 is elastically deformed, causing the second reactant layer 226 to be displaced through hollow activation zone 230 towards the first reactant layer 212, and once contacted, the second reactant layer 226 (being or comprising an adhesive matrix) adheres to metal film 216.

[0120] In this example, the first adhesive 210 has a lower adhesion strength to film 214 than that of the adhesion strength of the adhesive constituting (or being part of) the second reactant layer 226 to metal film 216. Hence, once second reactant layer 226 is adhered to metal film 216, and pressable section 224 returns to its non-pressed state (in the direction of arrow 234) due to its elasticity, a portion of metal film 216 and polymeric film 214 detaches from the first adhesive 210 and is displaced upwards together with second reactant layer 226, and the TTI device is activated.

[0121] A variant of the exemplary configuration of FIGS. 4A-4C is shown in FIGS. 5A-5C (elements having the same function as those in FIGS. 4A-4C are marked in FIGS. 5A-5C with a “ ” marking; the reader is directed to the description of FIGS. 4A-4C for full understanding of the functionality of such elements). In FIGS. 5A-5C, the first reactant layer 212′ is associated with substrate film 208′ through a release layer 254. The release layer 254 is bonded to the substrate film 208′ by adhesive 210′ and to polymeric film 214′ via adhesive 256. Release layer 254 comprises or is made of a material that binds to the polymeric film 214′ less effectively than the binding of the second reactant layer 226′ to the metal film 216′. Hence, due to the difference in binding, bringing the second reactant layer 226′ into contact with metal film 216′ by elastically deforming section 224′ will cause the second reactant layer 226′ to adhere to the metal film 216′, and when the pressable section 224′ returns to its substantively non-pressed state—a position of the first reactant layer 212′ will detach from the release layer 254 and its associated adhesive 256.

[0122] Another configuration of the TTI device is shown in FIGS. 6A-6B. In the device 300 shown in FIGS. 6A-6B, similar elements to those of FIGS. 1A-1C are included, shifted by 200. For example, spacer 306 in FIG. 3A has the same function as spacer 106 in FIG. 1A. Hence, the reader is referred to the description of FIG. 1A for a detailed description of the various functional elements.

[0123] Unlike the devices of FIGS. 1A-1C and 3A-5C, the TTI device 300 comprises the pressable section 324 that is plastically deformed when force is applied thereonto. Hence, once force is applied and removed, pressable section 324 does not return to its non-pressed state, and serves to further secure the adhered second reactant layer 326 and the first reactant layer 312 in position.

[0124] It is noted that in any of the variations of FIGS. 3A-6B, the same environmental protection configurations may be used as in the variants of FIGS. 1D-1E described above.

[0125] Another exemplary embodiment is shown in FIGS. 7A-7B. In the device 400 shown in FIGS. 8A-8B, similar elements to those of FIGS. 1A-1C are included, shifted by 300. For example, spacer 406 in FIG. 7A has the same function as spacer 106 in FIG. 1A. Hence, the reader is referred to the description of FIG. 1A for a detailed description of the various functional elements.

[0126] TTI device 400 comprises a first element 402 and a second element 404, separated by a spacer 406. Spacer 406 further comprises protrusions 460 that extend into hollow activation zone 430.

[0127] First element 402 comprises a substrate film 408, which is associated with first reactant layer 412 via release layer 454 (which is bonded to polymeric film 414 through adhesive 456). Second reactant layer 426, which is an adhesive that comprises or constitutes the second reactant, is attached to release layer 450, which is bonded carrier film 422 via adhesive 452 (as shown in FIG. 7A).

[0128] In this configuration, both the carrier film 422 and the first element 402 have pressable portions, such that when force is applied along oppositely directed arrows 432A and 432B, both the first element and the second element oppositely displace into hollow activation zone 430. In this embodiment, the second reactant layer 426 is larger than the opening defined between the protrusions 460, and hence will be arrested from further displacement within the hollow activation zone once contacting and binding to the protrusions 460. The first reactant layer 412 will be displaced in the direction of arrow 432B until a portion of metal film 416 contacts and adheres to second reactant layer 426. As the adhesion strength between the metal film 416 and the second reactant layer 426 is stronger than both the binding of adhesive 452 to the release layer 450 and from the adhesion strength of adhesive 410 to release layer 454—the second reactant layer 426 will detach together with release layer 450 from adhesive 452 and the portion of the first reactant layer 412 will detach together release layer 454 from adhesive 410 when the first and second elements return to their substantially non-pressed states (as shown in FIG. 7B).

[0129] Another variant of the configuration of FIGS. 7A-7B is shown in FIG. 8A-8B, with the only difference being the presence of membrane barrier member 462. Membrane barrier element 462 may be porous (or permeable) to the etchant contained in the second reactant layer 426 as to permit diffusion of the etchant through the membrane to cause etching of the metal film 416 when contacted. Alternatively, membrane barrier member 462 can be breakable or breachable upon application of force (e.g. along arrows 432A and/or 432B), such that once force is applied onto the device in order to bring the first and second reactant layers into contact with one another, such force is sufficient to break or breach the membrane barrier member 462 to permit contact between the etchant and the metal film.

[0130] Another device is shown in FIGS. 9A-9B, in which the pressable section is part of the substate film of the first element rather than of the carrier film of the second element. In the device 500 shown in FIGS. 9A-9B, similar elements to those of FIGS. 1A-1C are included, shifted by 400. For example, spacer 506 in FIG. 9A has the same function as spacer 106 in FIG. 1A. Hence, the reader is referred to the description of FIG. 1A for a detailed description of the various functional elements.

[0131] As can be seen, in the device 500, first element 502 has a pressable section 524, which can be pressed to displace the first reactant layer 512 into hollow reaction zone 530 towards second reactant layer 526. First reactant layer 512 is adhered to release layer 554 via adhesive 556; while release layer 554 is adhered to substrate film 508 via adhesive 510. As the adhesion strength between the active adhesive constituting second reactant layer 526 and metal layer 516 is stronger than the adhesion strength between adhesive 510 and release layer 554—once the first and second reactant layers are attached to one another by pressing onto pressable section 524, metal film 516 (together with polymeric film 514 and release layer 554) will detach from the substrate 508.