WO2012110702A2

WO2012110702A2 - Label with radio frequency transponder

Info

Publication number: WO2012110702A2
Application number: PCT/FI2012/050144
Authority: WO
Inventors: Soma KAZUHIKO; Goto TOYOHIRO; Yamakami HIROSHI
Original assignee: Upm Rfid Oy
Priority date: 2011-02-17
Filing date: 2012-02-15
Publication date: 2012-08-23
Also published as: WO2012110702A3

Abstract

According to an aspect of the invention,a label is provided, comprising: a facestock material layer; an adhesive layer; a metallic layer arranged between the adhesive layer and the facestock material layer for preventing or at least reducing migration of chemicals from or through the adhesive layer towards the facestock material layer, and a radio frequency identification transponder. A slot type antenna pattern is provided for the radio frequency identification transponder by the metallic layer, the antenna pattern being formed via absence of metal from a defined area of the metallic layer.

Description

LABEL WITH RADIO FREQUENCY TRANSPONDER

Field

The present invention relates to a label with radio-frequency tran- sponder. Background

Car and other vehicle tyres represent a significant size of market globally. This market would benefit from well-handled logistics as car tyres come in very wide variety of sizes, shapes and types. This forces the manufacturers and dealers to store and handle large amounts of tyres that need also to be individually identifiable. If such logistics are poorly handled, this leads to rise of expenses.

Labelling of tyres is a challenging task for many reasons. First of all, the rubber material provides a rather non-ideal surface for the self-adhesive labels to be attached. The surface is not even or smooth and many times it is covered with residual chemicals arising from the tyre manufacturing process. These reasons lead to the selection of strong and aggressive adhesives in order to ensure that the self-adhesive labels will hold to the tyre surface through- out the whole logistic chain from the manufacturing up to the point when the tyre is finally installed to a vehicle. Such adhesives often have chemicals that have a tendency to migrate to the face material of the label causing unwanted colouring, staining or other imperfections to the visual appearance of the label. Furthermore, the residual chemicals from the rubber material of the tyre may as well migrate through the pressure sensitive adhesive layer to the face material causing similar unwanted effects. To prevent this, metallic layers may be used in the label structure as migration barrier. In such labels, the structure of the label can be, for example, the following the layers listed from top surface to bottom: printed surface film typically of plastic - aluminium film attached to the surface film - pressure sensitive adhesive on the metal film - release liner to protect the sticky pressure sensitive adhesive. The release liner is removed from the label before the labelling action (manual or automatic) to expose the sticky pressure sensitive adhesive to provide adhesion to the tyre.

Traditionally, labels are printed with text and images for identifica- tion and advertising purposes. Furthermore, bar codes are often used to facilitate machine readability. Radio frequency identification (RFID) tags are well- known from many different type of applications. An RFID tag comprises basically a RF transponder composed from an antenna structure and a microcircuit attached to the antenna. In its simplest form such RFID tag is a so-called passive tag without any internal power source. Such tags are powered from the electromagnetic field created by a reader device and the tag can reply to the reader using so-called backscattering principle: the tag modulates and backscatters the electromagnetic field created by the reader and is thus able to identify itself with an identification code or depending of the capabilities of the tag even with further information stored in the tags memory. RFID tags provide convenient means to facilitate wireless identification over a significant reading distance of several meters.

However, the RFID tagging of tyres is not without challenges. The dielectric constant of the tyre can interfere with the functioning of the RFID tag attached onto the tyre surface. Typically modern tyres are also equipped with steel belt structures to enforce the tyre structure. It is well-known in the art that close presence of conducting materials will typically reduce the reading distance of RFID tags because of detuning the tags resonance circuitry. For example, in a warehouse the RFID tags should be readable from a distance and without effects arising from the fact how the tyres have been piled on the shelves, the options being the tags facing towards the reader or the tags facing away from the reader depending on the orientation of the tyres and depending on the shielding effect of the nearby other tyres or structures. In order to overcome these problems, typically the antenna area of the passive RFID tags needs to be increased in order to obtain better overall reading sensitivity. Natu- rally, this leads to the increase of the size of the RFID tag together with the increase of the tag manufacturing costs.

Brief description

According to an aspect of the present invention, there is provided a label, comprising a facestock material layer; an adhesive layer; a metallic layer arranged between the adhesive layer and the facestock material layer for preventing or at least reducing migration of chemicals from or through the adhesive layer towards the facestock material layer, and a radio frequency identification transponder. A slot type antenna pattern is provided for the radio fre- quency identification transponder by the metallic layer, the antenna pattern being formed via absence of metal from a defined area of the metallic layer. It has been surprisingly found out that there is a way to avoid or at least alleviate simultaneously at least some of the above indicated problems, i.e. the migration problem causing degration of the visual appearance of the label and the reading sensitivity problem caused by the electromagnetic prop- erties of the tyre. The metallic layer of the label can be used as migration barrier and to increase the effective area of the RFID transponder antenna. Thus, it becomes possible to improve readability of the RFID tags in such labels without requiring addition of any further layers or material.

According to an embodiment, the slot type antenna pattern is of di- pole type.

According to an embodiment, the slot type antenna pattern is arranged towards one end of the label.

According to an embodiment, the radio frequency identification transponder comprises a primary antenna and is arranged to use the slot type an- tenna pattern as a secondary antenna to boost the performance of the radio frequency identification transponder.

According to an embodiment, the radio frequency identification transponder comprises a loop type primary antenna arranged in inductive and/or capacitive communication with the slot type antenna pattern.

According to an embodiment, the radio frequency identification transponder is arranged between the facestock material layer and the metallic layer carrying the slot type antenna pattern.

According to an embodiment, the radio frequency identification transponder is arranged between the metallic layer carrying the slot type antenna pattern and the adhesive layer.

According to an embodiment, the radio frequency identification transponder is attached on the sticky side of the adhesive layer without any other adhesive means.

According to an embodiment, the label further comprises a remova- ble release liner protecting the adhesive layer.

According to a still further embodiment, the label is a tyre label. According to a further aspect of the invention, there is provided a method for manufacturing a label, comprising: providing input material comprising at least a metallic layer with absence of metal from a defined area of the metallic layer to form a slot type antenna pattern by the metallic layer; providing a radio frequency identification transponder for the label for electro- magnetic coupling with the slot type antenna pattern, and adding a facestock material layer and an adhesive layer at opposite sides of the metallic layer.

List of drawings

Embodiments of the present invention are described below, by way of example only, with reference to the accompanying drawings, in which

Figure 1 a is a schematic top view of a portion of an example label with RFID transponder;

Figure 1 b is a schematic side view of structure of an example label; Figure 2 is an example of RFID transponder with loop shaped antenna;

Figures 3a and 3b illustrated example structures for booster antennas;

Figure 4 illustrates an example of a metal layer with dipole shaped slot type antenna;

Figure 5 is an example of a tyre label according to an embodiment; Figure 6 is a top view of en example tyre label; and

Figure 7 is a top view of an example of the metal layer of the tyre label Figure 5.

Description of embodiments

Figure 1 a illustrates a label 1 , such as a tyre label, according to an embodiment. The label comprises an RFID transponder 2 comprising an integrated circuit attached to an antenna. The label 1 may have a general structure as illustrated in Figure 1 b: a facestock material sheet or layer 5, a metallic layer 3, pressure sensitive adhesive layer 6, and a release liner 7.

The facestock layer 5 of the label is of suitable material to enable printing of text and images. The facestock material is typically plastic or paper. In many label applications strong adhesives are required to ensure reliable attachment to a target product. The facestock 5 material may thus be protected by the metallic layer 3, to prevent or at least substantially reduce migration of chemicals from or through the adhesive layer towards the facestock material 5. The metallic layer 3 is often aluminum, but it will be appreciated that various other metals may be applied. The thickness of the layers may be varied, typi- cally layer thicknesses of around 10 to 100 micrometers are applied. According to present embodiments, at least one antenna pattern 4 is provided for the RFID transponder 2 by the metallic layer 3. The antenna pattern 4 may be formed by removing metal from a defined area of the metallic layer 3, in which case the antenna pattern may be referred to as a slot type antenna. Thus, the protective metallic layer 3, or actually an aperture thereof, of the label may serve as an antenna for the RFID transponder embedded in or attached on the label 1 .

In some embodiments, the RFID transponder 2 comprises a primary antenna and the antenna pattern 4 is used as a secondary booster antenna for the RFID transponder 2. For example, as illustrated in Figure 2, the primary antenna 9 connected to the IC 8 may be a loop type ultrahigh frequency (UHF) antenna. However, it will be appreciated that also other types of antennas may be applied as the primary antenna. The connection between the primary antenna 9 and secondary antenna 4 is preferably based on non-galvanic cou- pling, i.e. on inductive and/or capacitive coupling, but it is also possible that there is a galvanic connection between said antennas.

The RFID transponder 2 may be positioned on or at least nearby the antenna pattern 4 to enable coupling to the antenna pattern 4 electromagneti- cally. Positioning around the center area of the antenna pattern 4 is beneficial for the inductive and/or capacitive coupling between the primary and secondary antennas. For example, as illustrated in Figure 1 a, the RFID transponder 2 may be positioned in the center of the two branches of a dipole type antenna structure 4. There may be a non-conductive coating preventing connection between the loop antenna 9 and the metal layer 3, e.g. enclosing the entire transponder structure. However, depending on the form of the antenna pattern 4 and/or the tuning of the transponder 2, the transponder could also be positioned in one end of the antenna pattern 4. However, in an alternative embodiment, the transponder 2 is directly connected to the antenna structure 4, which in some cases could be used as the only antenna for the RFID IC.

The antenna pattern 4 formed on the metallic layer of the label can take different forms. The area and shape of the edges of the antenna pattern may be designed to provide desirable performance of the antenna. As illustrated in Figure 3a, the antenna could take a form of a metallized area 10 on a substrate with certain outer edge shape, but it has now been found that also similar shapes formed by removing metal from the corresponding area of similar shape will act as an antenna. In both cases the outer edge shape of the antenna can be equal but in the example of Figure 3a the antenna area is "filled" with metal 10 and the other example antenna of Figure 3b is a negative image with metal 1 1 on the outside of the antenna area. The slot type antenna pattern of Figure 3b may be formed by removing the metal inside the edges of the antenna shape. Both antenna types will act as booster antennas if a RFID transponder, such as the transponder of Figure 2 is arranged nearby. However, it will be appreciated that the illustrated dipole types of antenna structures represent only some example of available antenna forms that may be applied as the antenna pattern 4 by the protective metal layer in the label.

The RFID transponder 2 may be an UHF or very high frequency

(VHF) transponder, for example. In case of a loop type transponder, the diameter of the entire transponder structure may be around 10 mm, for example. One or more coatings may be applied on the RFID transponder to protect the RFID transponder, e.g. on the IC 8. It is to be appreciated that a large variety of already commercially available RFID transponders or transponder inlays may be applied for the present purposes.

The RFID transponder 2 may be attached on outer layers 5, 7 of the label 1 . However, in many cases it is desirable to have the RFID transponder embedded in the label 1 . In an embodiment, the RFID transponder 2 is ar- ranged between the facestock material layer 5 and the metallic layer 3 carrying the antenna pattern 4.

According to another embodiment, the RFID transponder is arranged between the metallic layer 3 and the adhesive layer 6.

According to a yet another embodiment, the RFID transponder is at- tached on the sticky side of the pressure sensitive adhesive layer 6, i.e. facing the liner 7. Thus, the attachment of the transponder 2 may be based on the pressure sensitive adhesion layer 6 of the label 1 .

The RFID transponder 2 may itself have a pressure sensitive adhesive surface to facilitate easy application onto a surface, such as directly onto the antenna pattern 4 functioning as the secondary booster antenna. Additional adhesive layer(s) may be applied when affixing the RFID transponder 2.

However, it is also possible to apply other means for attaching the transponder 2 in or on the label 1 . For example, lamination may be applied to include the transponder 2 between the different layers of the label 1 .

Figure 4 shows an example of a metall ic layer 3 with a dipole shaped secondary slot type antenna structure 4 and a transponder 2 with loop type primary antenna arranged into communication with the secondary antenna 4.

Figure 5 shows an example of a tyre label with printed facestock 5, metallic layer 3 with a slot type antenna structure 4 formed towards one end of the label and equipped with a RFID transponder 2 in communication with the slot antenna 4. The label further comprises pressure sensitive adhesive layer protected with a release liner 7, which may be made of siliconised paper, for example. Such tyre label may be around 8^*22 centimeters, for example. However, it will be appreciated that the size, form, as well as the position of the transponder 2 and the antenna structure 4 may be widely varied depending on the target application. For example, in case of a dipole type slot antenna structure for tyre label, the width of the antenna structure 4 could be between 1 to 15 centimeters and the height between 10 millimeter to 2 centimeters.

Figure 6 shows a more detailed picture of the facestock of the label in Fig. 5. The RFID transponder and the secondary slot antenna (not shown) are arranged in the left-side end of the label. The label has an additional enforcing layer indicated by a dashed line in the same end of the label in order to provide mechanical protection for the RFID transponder, especially for the critical galvanic connection between the integrated circuit and the primary anten- na. However, depending on the label structure and materials such additional protection may not be necessary.

Figure 7 shows a more detailed picture of the metallic layer 3 of the label in Fig. 5. Figure 7 shows the slot type antenna 4 formed onto the metallic sheet and also the position of the RFID transponder 2 arranged on the slot area communicating inductively and/or capacitively with the slot structure.

Although tyre labels have been illustrated above, it will be appreciated that the present features may be applied in a wide variety of label applications, where there is a need to have a protective layer, suitable for antenna formation purposes, to at least reduce migration of chemicals from or through the adhesive layer towards the facestock material. An example of such an application could be labeling plastic containers used for holding chemicals, for example plastic bottles or canister for holding oils. Ingredients of such chemicals may migrate through the wall of the plastic container and have adverse effects on the label without used of a metallic layer in between as barrier. Oth- er applications may include any applications requiring use of heavy-duty aggressive adhesives that need to be used, for example, due to problematic tar- get surfaces providing poor surface properties for adhesion, or in cases where a very strong adhesion is required to prevent removal of a label intended for permanent fixation, for example, in environmentally challenging (temperature, moisture) applications. The reason for having a metallic barrier layer in the la- bel may also be other than chemical, the barrier may be needed, for example, against radiation such as ultraviolet radiation. Applications requiring such barrier against chemical migration and/or radiation include, among others, packaging food or medical industry products.

The present features may thus be applied in label applications relat- ing to packaging of chemicals, in which applications there is a need to provide a label providing both an identification of the product by using the radio frequency identification and a protective layer for at least reducing the migration of chemicals or radiation through the label. The protective layer may thus prevent or at least reduce the migration of chemicals or their ingredients originat- ing either from the adhesive layer of the label or from the interior of the package or container of the chemical towards the facestock material of the label, as disclosed above. Alternatively, or at a same time, the protective layer may prevent or reduce the migration of chemicals or radiation from the surroundings of the package or container through the walls of the package or container to the actual chemical industry product inside the package or container. In these applications the protective layer may be an aluminum layer or made of some other electrically conductive metal material suitable for antenna formation purposes, whereby a slot type antenna pattern for the radio frequency identification transponder may be provided by the protective layer the same as dis- closed above.

According to an embodiment the chemical industry product is a pharmaceutical product and the label to be attached to the package of the pharmaceutical product is a label for pharmaceutical product.

According to an embodiment the chemical industry product is a cosmetic product and the label to be attached to the package of the cosmetic product is a label for cosmetic product.

The manufacturing of labels applying at least some of above- illustrated embodiments may be arranged in various ways. For example, such a production apparatus may comprise a unit or an element for each or at least some of the following production stages: providing input material comprising at least a metallic layer; removing metal from a defined area of the metallic layer to form a slot type antenna pattern by the metallic layer; provide a radio frequency identification transponder for coupling to the slot type antenna pattern, and adding a facestock material layer and an adhesive layer at opposite sides of the metallic layer. The removal of the metal layer portion to form the antenna structure may be arranged on the basis of a stamping or punching action applying accordingly formed stamp element, for example. The final label structure may be formed starting from the siliconized release liner 7, whereupon a suitable pressure sensitive adhesive is applied and then this structure is laminated onto a metallized plastic surface film with the slot type antenna and the tran- sponder. The order of the above described manufacturing steps may be freely chosen according to the application in question.

It will be appreciated that the application of the present invention should not be limited to the exact embodiments described herein, but according to the normal design skills of a man skilled in the art the label may have some further layer(s) provided, e.g. for mechanical stiffness and rigidity, as well as the RFID transponder could be of different type and shape. Furthermore, the slot type antenna pattern(s) 4 formed by removing metallic material from the metal layer can take any form, dimensions and location on the label applicable to the RFID frequencies relevant for the given application.

It will be obvious to a person skilled in the art that, as technology advances, the inventive concept can be implemented in various ways. The invention and its embodiments are not l imited to the examples described above but may vary within the scope of the claims. The features of the embodiments described herein may be combined in all possible combinations of methods, apparatuses, and products. Single features of different embodiments may be combined to provide other embodiments. The combinations of claim elements as stated in the claims and above embodiments can be changed in a number of different ways and still be within the scope of various embodiments of the invention.

Claims

1 . A self-adhesive label, comprising:

a facestock material layer;

an adhesive layer;

a metallic layer arranged between the adhesive layer and the facestock material layer for preventing or at least reducing migration of chemicals from or through the adhesive layer towards the facestock material layer, and

a radio frequency identification transponder;

wherein a slot type antenna pattern is provided for the radio frequency identification transponder by the metallic layer, the antenna pattern being formed via absence of metal from a defined area of the metallic layer.

2. The label according to claim 1 , wherein the slot type antenna pat- tern is of dipole type.

3. The label according to claim 1 or 2, wherein the slot type antenna pattern is arranged towards one end of the label.

4. The label according to any preceding claim, wherein the radio frequency identification transponder comprises a primary antenna and is arranged to use the slot type antenna pattern as a secondary antenna to boost the performance of the radio frequency identification transponder.

5. The label according to claim 4, wherein the radio frequency identification transponder comprises a loop type primary antenna arranged in inductive and/or capacitive communication with the slot type antenna pattern.

6. The label according to any preceding claim, wherein the radio frequency identification transponder is arranged between the facestock material layer and the metallic layer carrying the slot type antenna pattern.

7. The label according to any preceding claim 1 to 5, wherein the radio frequency identification transponder is arranged between the metallic layer carrying the slot type antenna pattern and the adhesive layer.

8. The label according to any preceding claim 1 to 5, wherein the radio frequency identification transponder is attached on the sticky side of the adhesive layer without any other adhesive means.

9. The label according to any preceding claim, further comprising a removable release liner protecting the adhesive layer.

10. The label according to any preceding claim, wherein the label is a tyre label.

1 1 . The label according to any preceding claim 1 to 9, wherein the label is a label for a pharmaceutical product.

12. The label according to any preceding claim 1 to 9, wherein the label is a label for a cosmetic product.

13. A method for manufacturing a label, comprising:

providing input material comprising at least a metallic layer with absence of metal from a defined area of the metallic layer to form a slot type an- tenna pattern by the metallic layer;

providing a radio frequency identification transponder for the label for electromagnetic coupling with the slot type antenna pattern, and

adding a facestock material layer and an adhesive layer at opposite sides of the metallic layer.