JP2019192084A - RF tag - Google Patents

Abstract

To provide an RF tag capable of being affixed to a product without generating heat or catching fire when a product is heated in a microwave oven.SOLUTION: An RF tag 10 includes: a base sheet 11 of a first resin; an RFID inlet 12 that includes an antenna 15 disposed on a surface 11a of the base sheet 11, which resonates with a radio wave having a frequency of microwave band, and an IC chip 16 connected to the antenna; and a protective sheet 13 covering at least the antenna 15. The protective sheet is composed of a second resin having a lower heat-resistant temperature than the first resin.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an RF tag that can be attached to a product heated in a microwave oven.

  In recent years, RFID (Radio Frequency Identification) technology has been used for inventory management and sales management of products. In the convenience store industry in particular, the shortage of manpower is a major problem, and therefore, inventory and accounting operations are made more efficient by attaching RF tags to products. Specifically, an RF tag storing information such as an identification code, product name, price, expiration date, etc. is attached to the product, and the information stored in the RF tag is contactless using a device called a reader / writer. By reading the above, it is possible to carry out inventory management, sales management, etc. of products (see, for example, Patent Document 1).

JP 2011-28715 A

  However, in the conventional technique such as Patent Document 1 described above, an RF tag using a frequency in the microwave band is heated while the antenna of the tag resonates with the microwave irradiated from the microwave oven. There was a problem that it could not be attached to products heated in a microwave oven such as sashimi and side dishes. When the antenna of the RF tag is heated in resonance with microwaves in the microwave oven, sparks are emitted from the antenna or the antenna becomes hot, which may cause a fire accident in the microwave oven or a container such as a lunch box or side dish May be deformed or have holes.

  The present invention has been devised in view of such problems of the prior art, and has as its main object to provide an RF tag that can be attached to a product heated in a microwave oven.

  An RF tag according to the present invention includes a base sheet made of a first resin, an antenna disposed on the surface of the base sheet, resonating with a radio wave having a frequency in a microwave band, and an IC chip connected to the antenna. It includes an inlet and a protective sheet that covers at least the antenna, and the protective sheet is made of a second resin having a lower heat resistant temperature than the first resin.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the RF tag which can be affixed on the goods heated with a microwave oven.

Sectional drawing which shows RF tag which concerns on this invention Top view of a base sheet included in the RF tag shown in FIG. The figure which shows the state which stuck the RF tag to the lunch The figure which shows a mode that the lunch box with which the RF tag was stuck is heated with a microwave oven The figure which shows the state which RF tag deform | transformed

  A first invention made to solve the above problems includes a base sheet made of a first resin, an antenna disposed on a surface of the base sheet and resonating with a radio wave having a frequency in a microwave band, and the antenna. An RFID inlet including a connected IC chip, and a protective sheet covering at least the antenna, wherein the protective sheet is made of a second resin having a lower heat resistant temperature than the first resin. To do.

  According to this, when heated in a microwave oven, an antenna (metal) that resonates with radio waves having a frequency in the microwave band resonates, and the protective sheet is heated and contracted by a heat source generated by this resonance, and this protective sheet By deforming the antenna by contraction deformation of the antenna, it is possible to prevent the antenna from resonating with the microwave of the microwave oven. Accordingly, it is possible to prevent a spark from the antenna of the RF tag and the antenna from becoming high temperature when heated in the microwave oven. Therefore, it is possible to provide an RF tag that can be attached to a product heated in a microwave oven.

  According to a second aspect, in the first aspect, the antenna is made of a nonmagnetic metal.

  According to this, at the time of heating in a microwave oven, it becomes possible to suppress heating of the antenna due to electromagnetic induction by microwaves in the microwave oven.

  Moreover, 3rd invention is that said adhesive or glue used for adhere | attaching the said protection sheet to the said surface of the said antenna or the said base sheet contains water | moisture content in said 2nd invention. Features.

  According to this, at the time of heating in a microwave oven, the protective sheet can be heated by vibrating water molecules of water contained in the adhesive or glue by microwaves irradiated from the microwave oven.

  According to a fourth aspect of the present invention, in the first to third aspects of the invention, when the first resin exceeds a heat resistant temperature of the resin, the shape is changed so as to be deformed into a predetermined deformation mode. It contains a memorized shape memory resin.

  According to this, the base sheet can be easily deformed into a predetermined deformation mode during heating in the microwave oven.

  Further, a fifth aspect of the present invention is the first aspect to the fourth aspect of the present invention, wherein the second resin is shaped so as to be deformed into a predetermined deformation mode when the heat resistance temperature of the resin is exceeded. It contains a memorized shape memory resin.

  According to this, at the time of heating in a microwave oven, it becomes possible to easily deform the protective sheet into a predetermined deformation mode.

  According to a sixth aspect of the present invention, in the first to fifth aspects of the present invention, when the antenna exceeds a heat resistant temperature of the first resin, the shape is deformed to a predetermined deformation mode. It is made of a memorized shape memory alloy.

  According to this, when the protective sheet is deformed, the antenna can be easily deformed into a predetermined deformation mode following the deformation.

  According to a seventh invention, in the first to sixth inventions described above, the RF tag is attached to at least a part of the region other than the peripheral portion on the back surface opposite to the front surface of the base sheet. It is characterized in that an adhesive layer for adhering to is provided.

  According to this, when the heat-resistant temperature of 1st resin is exceeded, the peripheral part of a protection sheet can change easily. In addition, the peripheral portion of the antenna and the base sheet can be easily deformed following the deformation of the protective sheet.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
First, a first embodiment of the present invention will be described. FIG. 1 is a cross-sectional view of an RF tag according to the present invention, and FIG. 2 is a top view of a base sheet 11 included in the RF tag shown in FIG. Note that FIGS. 1 and 2 are for illustrative purposes, and the components in the drawings are not to scale.

  As shown in FIG. 1, the RF tag 10 includes a base sheet 11, an RFID inlet 12 disposed on the surface of the base sheet 11, and a protective sheet that covers the RFID inlet 12 (hereinafter simply referred to as “inlet 12”). 13 and so on. The protective sheet 13 is bonded to the inlet 12 and the surface 11a of the base sheet 11 with an adhesive or glue (not shown).

  In addition, an adhesive layer 14 made of an adhesive is provided on at least a part (a central portion in FIG. 1) of the region other than the peripheral portion on the back surface 11 b of the base sheet 11. Although not shown, release paper for protecting the adhesive surface 14a is attached to the adhesive surface 14a of the adhesive layer 14 when the adhesive layer 14 is not used.

  The RF tag 10 is a type of RF tag that uses a frequency in the microwave band of 2.45 GHz. In the present embodiment, it is assumed that the RF tag 10 does not have a built-in battery and is a passive type that operates using radio waves received from a reader / writer as an energy source.

  As shown in FIG. 2, the inlet 12 disposed on the surface 11 a of the base sheet 11 includes an antenna 15 and an IC chip 16 connected to the antenna 15. The antenna 15 and the IC chip 16 constituting the inlet 12 are protected by a protective sheet 13 that covers the inlet 12 (see FIG. 1).

  The antenna 15 is a meander-shaped conductor pattern formed on the surface 11a of the base sheet 11 by plating, etching, or the like. In the present embodiment, a magnetic metal such as iron is used as the conductor. The shape of the conductor pattern is not limited to the meander shape, and may be various other shapes such as a straight shape, an L shape, and a folded shape.

  The antenna 15 transmits and receives signals using a reader / writer (not shown) and a microwave band frequency of 2.45 GHz. Various information (for example, identification code, product name, price, expiration date, etc.) relating to the product 20 (see FIG. 3) is stored in the IC chip 16. The IC chip 16 is equipped with a predetermined arithmetic processing function and the like.

  When the antenna 15 receives a signal from the reader / writer, the antenna 15 outputs the signal to the IC chip 16. The IC chip 16 executes predetermined arithmetic processing based on a command included in the signal input from the antenna 15 and outputs the processing result to the antenna 15. The antenna 15 transmits a signal including the processing result input from the IC chip 16 to the reader / writer.

  The base sheet 11 is made of a first resin, and the protective sheet 13 is made of a second resin having a heat resistant temperature lower than that of the first resin. The first resin and the second resin are such that the heat resistance temperature of the second resin is lower than the heat resistance temperature of the first resin (that is, the heat resistance temperature of the first resin is the heat resistance temperature of the second resin). Selected to be higher). For example, polystyrene (heat-resistant temperature is about 110 to 130 degrees) can be used as the first resin, and polystyrene (heat-resistant temperature is about 70 to 80 degrees) can be used as the second resin.

  The first resin and the second resin are not limited to a combination of polystyrene (PS) and polypropylene (PP), and the heat resistance temperature of the second resin is higher than the heat resistance temperature of the first resin. Various other resins such as polyethylene (PE), polyethylene terephthalate (PET), vinyl chloride (PVC) can be used as long as the temperature is low (that is, the heat resistance temperature of the first resin is higher than the heat resistance temperature of the second resin). Can be used.

  When the first resin and the second resin exceed the heat-resistant temperature, they contract and deform. Since the heat resistant temperature of the second resin is lower than the heat resistant temperature of the first resin, when the RF tag 10 is heated to a high temperature, the protective sheet 13 made of the second resin is made of the first resin. It contracts and deforms before the base sheet 11 is made.

  Although there are various modes of contraction deformation, in this embodiment, both end portions of the protective sheet 13 are contracted and deformed so as to curl toward the opposite side of the inlet 12. In addition, the contraction deformation | transformation aspect of the protection sheet 13 is not limited to this, For example, there can exist other various aspects, such as the aspect which the peripheral part of the protection sheet 13 shrinks and deforms toward a center part.

  The base sheet 11 is formed thin so that it can be deformed following the contraction deformation when the protective sheet 13 contracts. That is, the base sheet 11 is formed thin so that the waist becomes weak.

  The antenna 15 is also formed thin so that when the protective sheet 13 is contracted and deformed, it can be contracted and deformed following the contraction. Specifically, it may be formed to a thickness of about 0.1 mm.

  In the present embodiment, the protective sheet 13 contracts and deforms so that both end portions thereof are curled toward the opposite side of the inlet 12, so that both end portions of the base sheet 11 and the antenna 15 are formed on the protective sheet 13. Following the contraction deformation, it is formed so that it can curl toward the protective sheet 13 side.

  The RF tag 10 configured in this manner is attached to the product 20 heated by a microwave oven 30 (see FIG. 4) such as a lunch box or a side dish by the adhesive layer 14. In the present embodiment, the product 20 is a lunch box. FIG. 3 is a diagram illustrating a state where the RF tag 10 is attached to the surface of the container of the lunch box 20. Note that the product 20 is not limited to lunch boxes and side dishes, and may be other products as long as the product is heated in the microwave oven 30.

  FIG. 4 is a diagram illustrating a state where the lunch box 20 to which the RF tag 10 is attached is heated by the microwave oven 30. Hereinafter, the change of the RF tag 10 when the lunch box 20 is heated by the microwave oven 30 will be described.

  First, the microwave oven 30 heats the food in the lunch box 20 by irradiating the lunch box 20 with microwaves and oscillating water molecules of water contained in the food in the lunch box 20. At this time, since the resonance frequency (2.45 GHz) of the antenna 15 of the RF tag 10 overlaps with the frequency (2.45 GHz) of the microwave irradiated from the microwave oven 30, the antenna 15 is connected to the microwave of the microwave oven 30. Resonated and heated.

  Further, since the antenna 15 is made of a magnetic metal, an eddy current is generated on the surface of the antenna 15 due to electromagnetic induction by microwaves in the microwave oven 30, and the antenna 15 is also heated by induction heating due to this eddy current. The

  When the heated antenna 15 reaches a high temperature, the protection sheet 13 contracts due to the heat of the antenna 15. As described above, since the second resin constituting the protective sheet 13 has a lower heat resistant temperature than the first resin constituting the base sheet 11, the protective sheet 13 is deformed before the base sheet 11.

  When the protective sheet 13 is contracted and deformed, the antenna 15 (that is, the inlet 12) is deformed following the deformation. As described above, the antenna 15 can be deformed following the contraction deformation of the protective sheet 13.

  Further, when the protective sheet 13 is contracted and deformed, the base sheet 11 is also deformed following the deformation. As described above, the base sheet 11 can be deformed following the contraction deformation of the protective sheet 13.

  When the product 20 is heated in the microwave oven 30 in this way, the RF tag 10 attached to the product 20 is deformed. Further, the adhesive layer 14 for attaching the RF tag 10 to the product 20 is provided only at the central portion of the back surface 11b of the base sheet 11, and is not provided at the peripheral portion of the back surface 11b. When the heat resistance temperature is exceeded, the peripheral edge of the protective sheet 13 can be easily deformed. Further, following the deformation of the protective sheet 13, the peripheral portions of the antenna 15 and the base sheet 11 can be easily deformed.

  FIG. 5 is a diagram illustrating a state where the RF tag 10 is deformed. As shown in FIG. 5, the base sheet 11, the inlet 12, and the protective sheet 13 of the RF tag 10 are deformed so that both end portions thereof are curled toward the opposite side of the adhesive layer 14.

  As a result, the antenna 15 of the inlet 12 is deformed and its projected area is reduced. When the projected area of the antenna 15 is reduced, the resonance frequency (natural frequency) of the antenna 15 changes, so that the antenna 15 does not resonate with the microwave of the microwave oven 30. As a result, heating of the antenna 15 of the RF tag 10 due to resonance with the microwave of the microwave oven 30 can be prevented.

  As described above, according to the RF tag 10 according to the first embodiment of the present invention, the antenna 15 is deformed by contraction deformation of the protective sheet 13 during heating in the microwave oven, so that the antenna 15 becomes a micro of the microwave oven 30. It can be prevented from resonating with the wave. Accordingly, it is possible to prevent a spark from the antenna of the RF tag and the antenna from becoming high temperature when heated in the microwave oven. Therefore, it is possible to provide an RF tag that can be attached to a product heated in a microwave oven.

(Second Embodiment)
Next, the RF tag 10 according to the second embodiment of the present invention will be described. In the second embodiment, items not particularly mentioned below are the same as those in the first embodiment described above.

  In this second embodiment, the antenna 15 of the RF tag 10 is made of nonmagnetic metal instead of magnetic metal, and the adhesive or glue used for the protective sheet 13 contains moisture. This is different from the first embodiment.

  The antenna 15 is made of a nonmagnetic metal such as aluminum, copper, or stainless steel. A non-magnetic metal is less likely to be heated by microwaves in the microwave oven 30 because eddy currents are less likely to be generated by electromagnetic induction. Therefore, by manufacturing the antenna 15 from a nonmagnetic metal, the antenna 15 is suppressed from being heated due to electromagnetic induction by microwaves in the microwave oven 30.

  On the other hand, when the adhesive or glue used to adhere the protective sheet 13 to the inlet 12 or the surface 11a of the base sheet 11 contains water, the water molecules of water vibrate, and the protective sheet 13 is heated.

  When the lunch box 20 to which the RF tag 10 according to the second embodiment is attached is heated in the microwave oven 30, it is contained in the adhesive or glue used for the protective sheet 13 by the microwave irradiated from the microwave oven 30. The water molecules of the water that has been vibrated vibrate, and the protective sheet 13 is heated.

  In the second embodiment, since the antenna 15 is made of a nonmagnetic metal, heating of the antenna 15 due to electromagnetic induction by microwaves in the microwave oven 30 is suppressed.

  When the adhesive or paste containing moisture used for the heated protective sheet 13 becomes high temperature and exceeds the heat resistance temperature of the second resin constituting the protective sheet 13, the protective sheet 13 is contracted and deformed. When the protective sheet 13 is deformed, the antenna 15 (that is, the inlet 12) and the base sheet 11 are deformed following the deformation of the protective sheet 13 as in the case of the first embodiment.

  In this way, the base sheet 11, the inlet 12, and the protective sheet 13 of the RF tag 10 are warped toward the opposite side of the adhesive layer 14, as in the case of the first embodiment. And deformed so as to be rounded (see FIG. 5). As a result, the antenna 15 of the inlet 12 is deformed to reduce the projection area, and the resonance frequency (natural frequency) of the antenna 15 changes, so that the antenna 15 does not resonate with the microwave of the microwave oven 30. As a result, heating of the antenna 15 of the RF tag 10 due to resonance with the microwave of the microwave oven 30 can be prevented.

  As described above, according to the RF tag 10 according to the second embodiment of the present invention, the antenna 15 is made of a non-magnetic metal so that it can be used for electromagnetic induction by microwaves in the microwave oven 30 when heated in the microwave oven. The resulting heating of the antenna can be suppressed. Further, when the heating in the microwave oven is performed, the antenna 15 is not resonated with the microwave of the microwave oven 30 by deforming the antenna 15 by the contraction deformation of the protective sheet 13 as in the first embodiment. Can do. Accordingly, it is possible to prevent a spark from the antenna of the RF tag and the antenna from becoming high temperature when heated in the microwave oven. This makes it possible to provide an RF tag that can be attached to a product heated in a microwave oven.

  In the first and second embodiments described above, the first resin constituting the base sheet 11 stores a shape so as to be deformed into a predetermined deformation mode when the heat resistance temperature of the resin is exceeded. It may be a shape memory resin. According to this, at the time of heating in the microwave oven 30, the base sheet 11 can be easily deformed into a predetermined deformation mode.

  In the first embodiment and the second embodiment described above, the second resin constituting the protective sheet 13 stores a shape so as to be deformed into a predetermined deformation mode when the heat resistant temperature of the resin is exceeded. It may be a shape memory resin. According to this, at the time of heating in the microwave oven 30, the protective sheet 13 can be easily deformed into a predetermined deformation mode.

  Moreover, in said 1st Embodiment and 2nd Embodiment, when the heat-resistant temperature of 1st resin was exceeded as a conductor which comprises the antenna 15, the shape was memorize | stored so that it might deform | transform into a predetermined deformation | transformation aspect. It may be a shape memory alloy. According to this, when the protection sheet 13 is deformed, the antenna 15 can be easily deformed into a predetermined deformation mode following the deformation.

  As mentioned above, although this invention was demonstrated based on specific embodiment, these embodiment is an illustration to the last, Comprising: This invention is not limited by these embodiment. Further, all the components of the RF tag according to the present invention shown in the above embodiment are not necessarily essential, and can be appropriately selected as long as they do not depart from the scope of the present invention.

  The RF tag according to the present invention is useful as an RF tag that makes it possible to provide an RF tag that can be attached to a product heated in a microwave oven.

10 RF Tag 11 Base Sheet 11a Surface 12 RFID Inlet 13 Protective Sheet 14 Adhesive Layer 15 Antenna 16 IC Chip 20 Product (Bento)
30 Microwave oven

Claims (7)

A base sheet made of a first resin;
An RFID inlet including an antenna disposed on a surface of the base sheet and resonating with a radio wave having a frequency in a microwave band; and an IC chip connected to the antenna;
A protective sheet covering at least the antenna,
The RF tag, wherein the protective sheet is made of a second resin having a heat resistant temperature lower than that of the first resin.   The RF tag according to claim 1, wherein the antenna is made of a nonmagnetic metal.   The RF tag according to claim 2, wherein an adhesive or glue used for adhering the protective sheet to the surface of the antenna or the base sheet contains moisture.   4. The shape memory resin according to claim 1, wherein the first resin includes a shape memory resin having a shape memorized so as to be deformed into a predetermined deformation mode when the heat resistance temperature of the resin is exceeded. The RF tag according to any one of the above.   5. The shape memory resin according to claim 1, wherein the second resin includes a shape memory resin having a shape memorized so as to be deformed into a predetermined deformation mode when the heat resistance temperature of the resin is exceeded. The RF tag according to any one of the above.   The said antenna consists of a shape memory alloy memorize | stored in the shape so that it may deform | transform into a predetermined deformation | transformation aspect, when the heat-resistant temperature of said 1st resin is exceeded. The RF tag according to any one of the above.   The adhesive layer for sticking the said RF tag to a target object is provided in at least one part of areas other than the peripheral part in the back surface on the opposite side to the said surface of the said base sheet. The RF tag according to claim 6.

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