IC tag and method of manufacturing rubber products

Abstract

To provide an IC tag which is highly adhesive to rubber products.SOLUTION: An IC tag designed to be attached to a rubber product for use is provided. The IC tag comprises a base material sheet having a first surface and a second surface, an IC chip provided on the first surface of the base material sheet, and a first epoxy resin layer provided on the first surface of the base material sheet to cover the IC chip.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an IC tag and a method for manufacturing a rubber product. [Background technology]

[0002] In recent years, IC (Integrated Circuit) tags are sometimes attached to rubber products such as tires in order to realize traceability in the manufacturing process of the rubber products and for the maintenance of the rubber products after shipment. Patent Document 1 discloses fusing an RFID (Radio Frequency Identification) device into a rubber product while vulcanizing unvulcanized rubber. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2022-506921 Summary of the Invention [Problem to be solved by the invention]

[0004] In order to prevent the IC tag from peeling off from the rubber product during the manufacture or after shipping of the rubber product, it is important to ensure the adhesion of the IC tag to the rubber product. For example, when attaching the IC tag to the rubber product, it is possible to use a vulcanizing adhesive to bond the two while vulcanizing the rubber product. However, depending on the substrate of the IC tag, there is no vulcanizing adhesive that is compatible with both the substrate and the rubber, or it is not necessarily easy to obtain such a vulcanizing adhesive.

[0005] The present invention provides an IC tag that has high adhesiveness to rubber products, and a method for producing rubber products to which an IC tag is well adhered. [Means for solving the problem]

[0006] (1) An IC tag according to one aspect of the present invention is an IC tag that is attached to a rubber product for use, and comprises a base sheet having a first side and a second side, an IC chip disposed on the first side of the base sheet, and a first epoxy resin layer disposed on the first side of the base sheet so as to cover the IC chip.

[0007] (2) The IC tag of (1) above may further include a second epoxy resin layer disposed on the second surface of the base sheet.

[0008] (3) The IC tag of (1) or (2) above may further include a first vulcanized adhesive layer disposed on the surface of the first epoxy resin layer opposite to the base sheet.

[0009] (4) The IC tag of (1) or (2) above may further include a first woven fabric layer disposed on the surface of the first epoxy resin layer opposite to the base sheet.

[0010] (5) The IC tag of (2) above may further include a first vulcanized adhesive layer arranged on the side of the first epoxy resin layer opposite the substrate sheet, and a second vulcanized adhesive layer arranged on the side of the second epoxy resin layer opposite the substrate sheet.

[0011] (6) The IC tag of (2) above may further include a first woven fabric layer arranged on the side of the first epoxy resin layer opposite the base sheet, and a second woven fabric layer arranged on the side of the second epoxy resin layer opposite the base sheet.

[0012] (7) In any one of the IC tags (1) to (6) above, the base sheet may be made of polyimide.

[0013] (8) A method for producing a rubber product according to another aspect of the present invention includes preparing an IC tag as described above in (3) or (5), preparing unvulcanized rubber, and vulcanizing the unvulcanized rubber while bringing the unvulcanized rubber into contact with the first vulcanizing adhesive layer contained in the IC tag, thereby producing a rubber product having an IC tag attached.

[0014] (9) A method for producing a rubber product according to yet another aspect of the present invention includes preparing an IC tag as described above in (4) or (6), preparing unvulcanized rubber, and vulcanizing the unvulcanized rubber while bringing the unvulcanized rubber into contact with the first woven fabric layer included in the IC tag, thereby producing a rubber product having the IC tag attached. Effect of the Invention

[0015] According to the present invention, it is possible to provide an IC tag having high adhesiveness to rubber products, and to provide a method for producing a rubber product to which an IC tag is well adhered. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a schematic cross-sectional side view of an IC tag according to a first embodiment. [Diagram 2] FIG. 2 is a plan view of the inlay according to the first embodiment. [Figure 3A] 2A to 2C are diagrams illustrating a method for manufacturing a rubber product according to the first embodiment. [Figure 3B] FIG. 4 is another view illustrating the method for manufacturing a rubber product according to the first embodiment. [Figure 3C] FIG. 4 is yet another view illustrating the method for manufacturing a rubber product according to the first embodiment. [Figure 3D] FIG. 4 is yet another view illustrating the method for manufacturing a rubber product according to the first embodiment. [Figure 3E] FIG. 4 is yet another view illustrating the method for manufacturing a rubber product according to the first embodiment. [Figure 3F] FIG. 4 is yet another view illustrating the method for manufacturing a rubber product according to the first embodiment. [Figure 4]FIG. 11 is a schematic cross-sectional side view of an IC tag according to a second embodiment. [Diagram 5] FIG. 11 is a schematic cross-sectional side view of an IC tag according to a third embodiment. [Figure 6] 1 is a table showing an embodiment. [Figure 7] 1 is a table showing comparative examples. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, several embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and their description will not be repeated. In addition, in order to facilitate understanding, each drawing is drawn in a schematic manner with objects appropriately omitted or exaggerated.

[0018] <1. First embodiment> <1-1. IC tag structure> Fig. 1 shows a schematic side cross-sectional view of an IC tag 100 according to the first embodiment, and Fig. 2 shows a plan view of an inlay 101 included in the IC tag 100. The IC tag 100 is attached to a rubber product G for use. In addition to the IC tag 100, Fig. 1 also shows the rubber product G to which the IC tag 100 is attached. In the example of Fig. 1, the IC tag 100 is attached to the surface of the rubber product G. The rubber product G is, for example, a tire, although it is not limited thereto.

[0019] As shown in FIG. 1, the IC tag 100 includes a base sheet 1 and an IC chip 2 disposed on a first surface 1A of the base sheet 1. In the following description, for convenience of explanation, the top and bottom are defined based on the orientations of FIG. 1, 3A to 3D, 3F, 4, and 5. Therefore, of the pair of top and bottom surfaces of the base sheet 1, the top surface on which the IC chip 2 is disposed is called the first surface 1A, and the bottom surface is called the second surface 1B. However, the top and bottom in the following description do not necessarily coincide with the vertical top and bottom in the manufacturing process and in the use state of the IC tag 100 and the rubber product G to which the IC tag 100 is attached. The same applies to the IC tags 200 and 300 according to the second and third embodiments.

[0020] The IC tag 100 of this embodiment further includes an antenna 3. The antenna 3 is also disposed on the first surface 1A of the base sheet 1. In the example of Fig. 1, the IC chip 2 is disposed on the antenna 3, and is disposed on the base sheet 1 via the antenna 3.

[0021] The base sheet 1 and the IC chip 2 and antenna 3 mounted thereon constitute an inlay 101. The IC chip 2 can store data and communicates non-contact with an external device such as an RFID reader / writer via the antenna 3. This allows the external device to read and write data from and to the IC chip 2. This communication is realized, for example, by radio waves in the UHF band. The IC tag 100 may be of a passive type or an active type. Although not limited thereto, typical applications of the IC tag 100 include realizing traceability in the manufacturing process of the rubber product G and maintaining the rubber product G after shipment. In this case, various information related to the rubber product G (for example, identification information of the rubber product G, information indicating the time and contents of maintenance, etc.) is written into the IC chip 2.

[0022] The base sheet 1 is typically made of a resin material, but is not limited thereto. The base sheet 1 of this embodiment is made of polyimide. The base sheet 1 made of polyimide has excellent heat resistance, can withstand a high-temperature environment during vulcanization of the rubber product G described below, and can protect the IC chip 2 and the antenna 3. The base sheet 1 may contain components other than polyimide in addition to polyimide as the main component. The components other than polyimide may include, for example, a resin component different from polyimide, or may contain various additives instead of or in addition to the resin component. The thickness of the base sheet 1 is not particularly limited, but is, for example, 25 to 200 μm.

[0023] The IC chip 2 has a circuit structure that realizes a memory function. Although not limited thereto, the antenna 3 of this embodiment is a dipole antenna. The antenna 3 is electrically connected to the IC chip 2. In the example of FIG. 2, the antenna 3 has an impedance matching section 31 and a pair of dipole sections 32, 32 arranged on the left and right of the impedance matching section 31. The base sheet 1 of this embodiment is rectangular. The impedance matching section 31 is a rectangular frame and is arranged near the center of the longitudinal direction (left and right direction) of the base sheet 1. The left dipole section 32 is generally in the shape of a rectangular spiral, and the outer end of the spiral extends to near the center of one side of the impedance matching section 31 and is continuous with the part near the center. The pair of dipole sections 32, 32 are roughly symmetrical, and the right dipole section 32 also has a similar shape.

[0024] The antenna 3 is made of a conductive material such as silver, copper, or aluminum, but is not limited thereto. The antenna 3 can be formed on the first surface 1A of the base sheet 1 by using such a material, by a method such as screen printing or etching. The thickness of the antenna 3 is not particularly limited, but is, for example, 5 to 20 μm. In the example of FIG. 2, the IC chip 2 is fixed near the center of one side of the impedance matching section 31. The IC chip 2 is fixed on the antenna 3 by various methods. Possible fixing methods include a method using a conductive adhesive such as ACP (anisotropic conductive paste), flip chip mounting, and the like. The thickness of the IC chip 2 is not particularly limited, but is, for example, 20 to 150 μm.

[0025] The IC tag 100 further includes a first epoxy resin layer 4. In this embodiment, the first epoxy resin layer 4 is disposed on the first surface 1A of the base sheet 1 so as to cover the IC chip 2 and the antenna 3. The first epoxy resin layer 4 seals the IC chip 2 and the antenna 3 on the base sheet 1. This protects the IC chip 2 and the antenna 3, and more firmly fixes the positions of the IC chip 2 and the antenna 3 on the base sheet 1. The IC chip 2 and the antenna 3 are sandwiched between the first surface 1A of the base sheet 1 and the first surface 4A of the first epoxy resin layer 4. Here, of the pair of upper and lower surfaces of the first epoxy resin layer 4, the lower surface facing the base sheet 1 is referred to as the first surface 4A, and the upper surface is referred to as the second surface 4B. The first epoxy resin layer 4 covers the entire upper surface of the inlay 101.

[0026] The first epoxy resin layer 4 is mainly composed of epoxy resin, which is a thermosetting resin. The first epoxy resin layer 4 may contain a component other than epoxy resin. The component other than epoxy resin may contain, for example, a resin component different from epoxy resin, or may contain various additives instead of or in addition to the epoxy resin. The thickness of the first epoxy resin layer 4 is not particularly limited, but is, for example, 20 to 500 μm. The ratio of the thickness of the first epoxy resin layer 4 to the thickness of the IC chip 2 is preferably 1 or more, and more preferably 1.1 or more. The upper limit of this ratio is appropriately determined depending on the type and application of the IC tag 100 and the rubber product G, but the ratio of the thickness of the first epoxy resin layer 4 to the thickness of the IC chip 2 is preferably 10 or less, and more preferably 5 or less.

[0027] As described above, in this embodiment, the first epoxy resin layer 4 is laminated on the first surface 1A of the base sheet 1 included in the inlay 101. The first epoxy resin layer 4 covers the IC chip 2 and the antenna 3 on the first surface 1A from above, and absorbs the unevenness of the upper surface of the inlay 101 caused by the presence of the IC chip 2 (and the antenna 3 in some cases). Note that absorbing the unevenness here includes eliminating the unevenness and flattening the second surface 4B (the surface opposite to the inlay 101) of the first epoxy resin layer 4 covering the upper surface of the inlay 101, as well as mitigating the unevenness. That is, the second surface 4B of the first epoxy resin layer 4 is not necessarily flat, and may form a gentle surface as shown in FIG. 1, or may have unevenness. However, the surface unevenness of the second surface 4B is smaller than that of the upper surface of the inlay 101.

[0028] In this embodiment, the presence of the first epoxy resin layer 4 as described above absorbs the unevenness of the upper surface of the inlay 101, making it difficult for unnecessary gaps to occur when attaching the IC tag 100 to the rubber product G. In addition, the possibility of stress concentration occurring from the unevenness of the upper surface of the inlay 101 during vulcanization bonding, which will be described later, can be reduced. As a result, the IC tag 100 is prevented from peeling off from the rubber product G, and the adhesion between the IC tag 100 and the rubber product G is improved.

[0029] Moreover, the IC tag 100 of this embodiment further includes a first vulcanized adhesive layer 5. The first vulcanized adhesive layer 5 is disposed on the second surface 4B of the first epoxy resin layer 4, and in this embodiment, covers the entire second surface 4B. As described above, the second surface 4B is the surface of the first epoxy resin layer 4 opposite to the base sheet 1.

[0030] The first vulcanizing adhesive layer 5 is composed of a vulcanizing adhesive. The vulcanizing adhesive selected here is one that has high adhesion to both the components of the portion of the rubber product G where the IC tag 100 is attached and the components of the first epoxy resin layer 4. The first vulcanizing adhesive layer 5 may contain components other than the vulcanizing adhesive. The thickness of the first vulcanizing adhesive layer 5 is not particularly limited, but is preferably 10 to 40 μm, and more preferably 10 to 20 μm.

[0031] However, a vulcanization adhesive compatible with both the base sheet 1 and the rubber product G is not necessarily easily available. In particular, generally, there is no vulcanization adhesive compatible with both polyimide and rubber. In this respect, in this embodiment, the first epoxy resin layer 4 and the first vulcanization adhesive layer 5 are inserted between the rubber product G and the inlay 101. That is, the rubber product G and the base sheet 1 included in the inlay 101 are not directly bonded using a vulcanization adhesive, but are indirectly bonded to the base sheet 1 side via the first epoxy resin layer 4. As a result, the adhesion between the IC tag 100 and the rubber product G is ensured, and the IC tag 100 is prevented from peeling off from the rubber product G. In addition, as described above, the IC tag 100 of this embodiment can exhibit a good adhesion function with the rubber product G with a simple structure. Therefore, since the IC tag 100 has a small number of layers and is thin, it has excellent resistance to stress in the shear direction and is prevented from breaking down.

[0032] <1-2. Manufacturing methods for rubber products> 3A to 3F, a method for manufacturing the above-mentioned IC tag 100 and the rubber product G to which the IC tag 100 is attached will be described below. Note that the manufacturing method described here is an example, and the above-mentioned IC tag 100 and the rubber product G can also be manufactured by other methods.

[0033] First, an inlay 101 is manufactured as shown in Fig. 3A. Specifically, a base sheet 1 is prepared. Then, a circuit for an antenna 3 is formed on a first surface 1A of the base sheet 1 by a method such as screen printing or etching as described above. Furthermore, an IC chip 2 is fixed to a predetermined position on the antenna 3 by a method such as using a conductive adhesive or flip chip mounting as described above. In this embodiment, in order to simultaneously manufacture a large number of IC tags 100, patterns of antennas 3 and IC chips 2 corresponding to a large number of IC tags 100 are formed side by side on one base sheet 1.

[0034] Next, a first epoxy resin layer 4 is formed on the base sheet 1 included in the inlay 101. Specifically, as shown in FIG. 3B, an epoxy resin sheet 4 (the sheet before processing is also designated by reference symbol 4) is prepared and superimposed on the first surface 1A of the base sheet 1. Next, a vacuum press is used to press the epoxy resin sheet 4 against the base sheet 1 in a planar manner. During this process, the sheet 4 is appropriately heated. As a result, as shown in FIG. 3C, a first epoxy resin layer 4 integrated with the inlay 101 is formed, and the IC chip 2 and the antenna 3 are sealed between the base sheet 1 and the first epoxy resin layer 4. In the example of FIG. 3C, the second surface 4B of the first epoxy resin layer 4 opposite the inlay 101 forms a gentle surface and is formed approximately flat. Note that the above method using a vacuum press prevents air from entering between the first epoxy resin layer 4 and the inlay 101. That is, no gaps are generated at the interfaces between the first epoxy resin layer 4 and the base sheet 1, the IC chip 2, and the antenna 3. This suppresses failure of the IC tag 100 (mainly failure of the circuits of the IC chip 2 and the antenna 3) that may occur due to air expansion during the vulcanization process of the rubber product G described later.

[0035] The method for forming the first epoxy resin layer 4 is not limited to the above method, and the following method may be considered as another method. As shown in Fig. 3D, liquid epoxy resin 4 (the epoxy resin as the material before processing is also designated by reference symbol 4) is applied to the first surface 1A of the base sheet 1 using a brush or the like, and then appropriately cured or solidified. As a result, the first epoxy resin layer 4 integrated with the base sheet 1 is formed as shown in Fig. 3C.

[0036] Next, a first vulcanizing adhesive layer 5 is formed on the second surface 4B of the first epoxy resin layer 4. Specifically, as shown in FIG. 3E, a pair of rollers 20, 20 are prepared, and a liquid vulcanizing adhesive 5 (the vulcanizing adhesive, which is a material before processing, is also designated by reference symbol 5) is applied to the surface of one of the rollers 20 in advance. Then, the laminate of the inlay 101 and the first epoxy resin layer 4 is passed between the rollers 20, 20, so that the vulcanizing adhesive 5 is transferred from the roller 20 to the first epoxy resin layer 4. At this time, the laminate is passed so that the first epoxy resin layer 4 faces the roller 20 side to which the vulcanizing adhesive 5 is applied. Thereafter, the vulcanizing adhesive 5 is appropriately cured or solidified to form the first vulcanizing adhesive layer 5 integrated with the first epoxy resin layer 4. Note that the IC chip 2 and the antenna 3 are covered and protected by the first epoxy resin layer 4 as described above. Therefore, in the pressing process by the rollers 20, 20, the mechanical load applied to the IC chip 2 and the antenna 3 is reduced, and failure of the IC tag 100 (mainly failure of the circuits of the IC chip 2 and the antenna 3) is suppressed.

[0037] The method for forming the first vulcanizing adhesive layer 5 is not limited to the above method, and for example, the following method may be considered as another method. The liquid vulcanizing adhesive 5 may be applied to the second surface 4B of the first epoxy resin layer 4 using a brush or the like, and then appropriately cured or solidified. In this way, the first vulcanizing adhesive layer 5 integrated with the first epoxy resin layer 4 is formed.

[0038] As described above, the second surface 4B of the first epoxy resin layer 4 has less unevenness than the upper surface of the inlay 101. This prevents air bubbles from being generated at the interface with the first epoxy resin layer 4 when the first vulcanization adhesive layer 5 is formed.

[0039] In this manner, the IC tag 100 is manufactured to be attached to the rubber product G. However, since the above process results in a large number of IC tags 100 being connected to a single sheet, the sheet is appropriately cut to prepare the individually separated IC tags 100.

[0040] Next, an unvulcanized rubber product G is prepared. The term "unvulcanized" here means that the degree of vulcanization is low compared to the state of the final product. Then, as shown in FIG. 3F, the unvulcanized rubber product G is vulcanized in a state where the first vulcanization adhesive layer 5 included in the IC tag 100 is in contact with the unvulcanized rubber product G. Specifically, the IC tag 100 is attached to a predetermined portion of the surface of the unvulcanized rubber product G with the surface of the first vulcanization adhesive layer 5 facing. Then, in this state, the rubber product G and the IC tag 100 are heated. During this time, pressure may be applied. In addition, such heating and pressure can be performed in a mold. This allows the vulcanization reaction of the rubber product G to proceed. In addition, during this time, the adhesion reaction between the rubber product G and the first vulcanization adhesive layer 5 also proceeds, and the IC tag 100 and the rubber product G are integrated. In addition, the vulcanization adhesive constituting the first vulcanization adhesive layer 5 has excellent adhesion to both the rubber product G and the first epoxy resin layer 4. Therefore, the first epoxy resin layer 4 and the rubber product G are firmly bonded via the first vulcanization adhesive layer 5. In this manner, the rubber product G to which the IC tag 100 is well bonded is manufactured.

[0041] <2. Second embodiment> An IC tag 200 according to a second embodiment of the present invention will be described below. Fig. 4 is a schematic side cross-sectional view of the IC tag 200 according to the second embodiment. As can be seen from a comparison of Fig. 1 and Fig. 4, the IC tag 200 according to the second embodiment differs from the IC tag 100 according to the first embodiment in that it has additional layers 204, 205. The following description of the IC tag 200 according to the second embodiment will focus on the differences from the first embodiment, and a description of the commonalities will be omitted.

[0042] <2-1. Structure of IC tag> The IC tag 200, like the IC tag 100, includes an inlay 101 and a first epoxy resin layer 4 covering the upper surface of the inlay 101, and further includes a second epoxy resin layer 204. The second epoxy resin layer 204 is disposed on the second surface 1B of the base sheet 1. That is, the two epoxy resin layers 4, 204 are disposed on the opposite surfaces of the base sheet 1 with the base sheet 1 sandwiched therebetween. Here, of the pair of upper and lower surfaces of the second epoxy resin layer 204, the upper surface facing the base sheet 1 is referred to as the first surface 204A, and the lower surface is referred to as the second surface 204B. The second epoxy resin layer 204 covers the entire second surface 1B of the base sheet 1.

[0043] Similarly to the IC tag 100, the IC tag 200 includes a first vulcanized adhesive layer 5 and further includes a second vulcanized adhesive layer 205. The second vulcanized adhesive layer 205 is disposed on the second surface 204B of the second epoxy resin layer 204, and in this embodiment, covers the entire second surface 204B. As described above, the second surface 204B is the surface of the second epoxy resin layer 204 opposite the base sheet 1. That is, the two vulcanized adhesive layers 5, 205 are disposed separately on both sides of the base sheet 1 with the base sheet 1 (and the two epoxy resin layers 4, 204) sandwiched therebetween.

[0044] Like the first epoxy resin layer 4, the second epoxy resin layer 204 is mainly composed of epoxy resin, which is a thermosetting resin. The second epoxy resin layer 204 may also contain components other than epoxy resin. The components other than epoxy resin may include, for example, a resin component different from epoxy resin, or may contain various additives instead of or in addition to the epoxy resin. The thickness of the second epoxy resin layer 204 is not particularly limited, but is, for example, 20 to 500 μm. The second epoxy resin layer 204 can be formed to have the same thickness as the first epoxy resin layer 4 using materials with the same composition.

[0045] The second vulcanizing adhesive layer 205 is made of a vulcanizing adhesive. The vulcanizing adhesive selected here is one that has high adhesion to both the components of the portion of the rubber product G where the IC tag 200 is attached and the components of the second epoxy resin layer 204. The second vulcanizing adhesive layer 205 may also contain components other than the vulcanizing adhesive. The thickness of the second vulcanizing adhesive layer 205 is not particularly limited, but is preferably 10 to 40 μm, and more preferably 10 to 20 μm. The second vulcanizing adhesive layer 205 can be configured to have the same thickness as the first vulcanizing adhesive layer 5 by using materials with the same composition as the first vulcanizing adhesive layer 5.

[0046] As described above, the IC tag 200 includes the epoxy resin layers 4, 204 on both the top and bottom surfaces of the inlay 101, and the vulcanization adhesive layers 5, 205 covering these layers from the outside. As a result, the IC tag 200 has excellent adhesion to the rubber product G on both the top and bottom surfaces. Therefore, the IC tag 200 is suitable for use in being embedded inside the rubber product G, in addition to being attached to the surface of the rubber product G. If a cavity is formed inside the rubber product G, this can cause deterioration such as cracks in the rubber product G. In this regard, the IC tag 200 is less likely to peel off from the interface with the rubber, and is less likely to cause the above-mentioned deterioration even when embedded inside the rubber product G.

[0047] As in the first embodiment, in the second embodiment, the rubber product G and the base sheet 1 included in the inlay 101 are not directly bonded to each other using a vulcanizing adhesive, but are indirectly bonded to the base sheet 1 side via an epoxy resin layer 4, 204. As a result, the adhesion between the IC tag 200 and the rubber product G is ensured, and the IC tag 200 is prevented from peeling off from the rubber product G. As described above, the IC tag 200 of this embodiment can also exhibit a good adhesive function to the rubber product G with a simple structure. Therefore, the IC tag 200 also has a small number of layers and is thin, so it has excellent resistance to stress in the shear direction and is prevented from breaking down.

[0048] <2-2. Manufacturing methods of rubber products> Next, a manufacturing method for the above-mentioned IC tag 200 and the rubber product G to which it is attached will be described. Here, a manufacturing method will be described in which the IC tag 200 is embedded in the rubber product G. Note that the manufacturing method described here is also an example, and the above-mentioned IC tag 200 and rubber product G can also be manufactured by other methods. In addition, since the manufacturing method described here has many points in common with the manufacturing method of the first embodiment, the differences from the first embodiment will be mainly described while referring to the description of the first embodiment.

[0049] First, the inlay 101 is manufactured in the same manner as in the first embodiment. Next, a first epoxy resin layer 4 and a second epoxy resin layer 204 are formed on the first surface 1A and the second surface 1B of the base sheet 1 included in the inlay 101, respectively. The method of forming the first epoxy resin layer 4 on the first surface 1A has already been explained, and the second epoxy resin layer 204 can be formed on the second surface 1B in the same manner. The two epoxy resin layers 4, 204 may be formed simultaneously, or one may be formed first and then the other.

[0050] Next, the first vulcanized adhesive layer 5 is formed on the second surface 4B of the first epoxy resin layer 4, and the second vulcanized adhesive layer 205 is formed on the second surface 204B of the second epoxy resin layer 204. The method of forming the first vulcanized adhesive layer 5 on the second surface 4B has already been described, and the second vulcanized adhesive layer 205 can be formed on the second surface 204B in a similar manner. The two vulcanized adhesive layers 5, 205 may be formed simultaneously, or one may be formed and then the other may be formed. When the vulcanized adhesive layers 5, 205 are formed simultaneously using the rollers 20, 20, the vulcanized adhesive 5 may be applied to both rollers 20, 20 in advance.

[0051] In this manner, the IC tag 200 is manufactured to be embedded in the rubber product G. Here, too, the multiple connected IC tags 200 are appropriately cut to prepare the individually separated IC tags 200.

[0052] Next, an unvulcanized rubber product G is prepared. Then, an IC tag 200 is embedded inside the unvulcanized rubber product G. As a result, the first vulcanization adhesive layer 5 and the second vulcanization adhesive layer 205 included in the IC tag 200 are in contact with the unvulcanized rubber product G. At this time, the first vulcanization adhesive layer 5 and the second vulcanization adhesive layer 205 are attached to the area surrounding the IC tag 200 inside the unvulcanized rubber product G. In this state, the unvulcanized rubber product G is vulcanized. Specifically, similar to the first embodiment, the rubber product G and the IC tag 200 are heated and appropriately pressurized. As a result, the vulcanization reaction of the rubber product G, the adhesion reaction between the rubber product G and the first vulcanization adhesive layer 5, and the adhesion reaction between the rubber product G and the second vulcanization adhesive layer 205 progress, and the IC tag 200 and the rubber product G are integrated. As a result, a rubber product G to which the IC tag 200 is well adhered is manufactured.

[0053] <3. Third embodiment> Hereinafter, an IC tag 300 according to a third embodiment of the present invention will be described. Fig. 5 is a schematic side cross-sectional view of the IC tag 300 according to the third embodiment. As can be seen by comparing Fig. 5 with Fig. 4, the IC tag 300 according to the third embodiment differs from the IC tag 200 according to the second embodiment in that it has woven fabric layers 301, 302 instead of the vulcanized adhesive layers 5, 205, respectively. Hereinafter, the IC tag 300 according to the third embodiment will be described, focusing on the differences from the first and second embodiments, and a description of the commonalities will be omitted.

[0054] <3-1. Structure of IC tag> Like the IC tags 100 and 200, the IC tag 300 includes an inlay 101 and a first epoxy resin layer 4 covering the upper surface of the inlay 101, and further includes a first woven fabric layer 301. The first woven fabric layer 301 is disposed on the second surface 4B of the first epoxy resin layer 4, and in this embodiment, covers the entire second surface 4B. As described above, the second surface 4B is the surface of the first epoxy resin layer 4 opposite to the base sheet 1.

[0055] Similarly to the IC tag 200, the IC tag 300 includes a second epoxy resin layer 204 and further includes a second woven fabric layer 302. The second woven fabric layer 302 is disposed on the second surface 204B of the second epoxy resin layer 204, and in this embodiment, covers the entire second surface 204B. As described above, the second surface 204B is the surface of the second epoxy resin layer 204 opposite the base sheet 1. That is, the two woven fabric layers 301, 302 are disposed separately on both sides of the base sheet 1 with the base sheet 1 (and the two epoxy resin layers 4, 204) sandwiched therebetween.

[0056] The first woven fabric layer 301 and the second woven fabric layer 302 are both made of woven fabric. Although not limited thereto, the first woven fabric layer 301 and the second woven fabric layer 302 in this embodiment are made of canvas. The canvas can be made, for example, as a woven fabric made by plain weaving twisted yarn. The material of the yarn can be appropriately selected and may be natural fibers such as cotton and hemp, or chemical fibers such as polyester and nylon. The first woven fabric layer 301 and the second woven fabric layer 302 may be made of the same type of yarn or different types of yarn. The thicknesses of the first woven fabric layer 301 and the second woven fabric layer 302 may be the same or different.

[0057] In this embodiment, the first woven fabric layer 301 and the second woven fabric layer 302 are the interface between the IC tag 300 and the rubber product G. The first woven fabric layer 301 and the second woven fabric layer 302 generate an anchor effect due to the structure of the fabric. That is, the first woven fabric layer 301 and the second woven fabric layer 302 typically have a woven structure in which warp and weft threads cross, and the rubber product G penetrates and bites into this structure during vulcanization. The first epoxy resin layer 4 and the second epoxy resin layer 204 can also penetrate and bite into it in the same way. This ensures adhesion between the IC tag 300 and the rubber product G, and prevents the IC tag 300 from peeling off from the rubber product G. In this embodiment, the adhesion is due to the anchor effect, so that flexible adhesion is possible. As described above, the IC tag 300 of this embodiment can also exhibit good adhesion function with the rubber product G with a simple structure. Therefore, the IC tag 300 also has a small number of layers and is thin, so that it has excellent resistance to stress in the shear direction and is prevented from breaking down.

[0058] As described above, the IC tag 300 has epoxy resin layers 4, 204 on both the top and bottom surfaces of the inlay 101, and further has woven fabric layers 301, 302 covering these layers from the outside. As a result, the IC tag 300 has excellent adhesion to the rubber product G on both the top and bottom surfaces. Therefore, the IC tag 300 is suitable not only for attachment to the surface of the rubber product G, but also for embedding inside the rubber product G. The IC tag 300 is less likely to peel off from the interface with the rubber, and is less likely to cause deterioration such as cracks even when embedded inside the rubber product G.

[0059] <3-2. Manufacturing methods of rubber products> Next, a manufacturing method for the above-mentioned IC tag 300 and the rubber product G to which it is attached will be described. Here, a manufacturing method will be described in which the IC tag 300 is embedded in the rubber product G. Note that the manufacturing method described here is also an example, and the above-mentioned IC tag 300 and rubber product G can also be manufactured by other methods. In addition, since the manufacturing method described here has many points in common with the manufacturing methods of the first and second embodiments, the following description will focus on the differences from the first and second embodiments while referring to the descriptions of the first and second embodiments.

[0060] First, the inlay 101 is manufactured, and then the first epoxy resin layer 4 and the second epoxy resin layer 204 are formed. The flow up to this point is the same as in the second embodiment.

[0061] Next, a first woven fabric layer 301 is formed on the second surface 4B of the first epoxy resin layer 4, and a second woven fabric layer 302 is formed on the second surface 204B of the second epoxy resin layer 204. Specifically, a woven fabric sheet 301 (the sheet as a material is also designated by reference symbol 301) is prepared and superimposed on the second surface 4B of the first epoxy resin layer 4. Similarly, another woven fabric sheet 302 (the sheet as a material is also designated by reference symbol 302) is prepared and superimposed on the second surface 204B of the second epoxy resin layer 204. Here, the woven fabric sheets 301 and 302 are merely superimposed on the epoxy resin layer 4 and 204, and do not need to be integrated with the epoxy resin layer 4 and 204 and fixed firmly. However, in order to facilitate subsequent handling, the woven fabric sheets 301 and 302 may be lightly or firmly fixed to the epoxy resin layer 4 and 204 by a method such as heat pressing or tape attachment.

[0062] In this manner, the IC tag 300 is prepared for embedding in the rubber product G. Here, too, the multiple connected IC tags 300 are appropriately cut to prepare the individually separated IC tags 300.

[0063] Next, an unvulcanized rubber product G is prepared. Then, an IC tag 300 is embedded inside the unvulcanized rubber product G. As a result, the first woven fabric layer 301 and the second woven fabric layer 302 included in the IC tag 300 are in contact with the unvulcanized rubber product G. In this state, the unvulcanized rubber product G is vulcanized. Specifically, similar to the first and second embodiments, the rubber product G and the IC tag 300 are heated and appropriately pressurized. As a result, the vulcanization reaction of the rubber product G progresses, and the components of the rubber product G penetrate and bite into the fabric structure of the first woven fabric layer 301 and the second woven fabric layer 302. At the same time, the components included in the first epoxy resin layer 4 and the second epoxy resin layer 204 can also penetrate and bite into the fabric structure of the first woven fabric layer 301 and the second woven fabric layer 302. As a result, the epoxy resin layers 4, 204, the woven fabric layers 301, 302, and the rubber product G are integrated. In this manner, the rubber product G to which the IC tag 300 is adhered satisfactorily is manufactured.

[0064] <4. Modifications> Although several embodiments of the present invention have been described above, the present invention is not limited to the above-mentioned embodiments, and various modifications are possible without departing from the spirit of the present invention. For example, the following modifications are possible.

[0065] <4-1> In the third embodiment, the second woven fabric layer 302 may be omitted. That is, a woven fabric layer (first woven fabric layer 301) may be disposed on only one side of the inlay 101. Although not limited thereto, an IC chip having a woven fabric layer on only one side is suitable for use in being attached to the surface of a rubber product G. When the second woven fabric layer 302 is omitted, the second epoxy resin layer 204 may also be omitted. Conversely, in the third embodiment, the first woven fabric layer 301 may be omitted instead of the second woven fabric layer 302.

[0066] <4-2> In the above embodiment, an example was shown in which the first vulcanizing adhesive layer 5 or the first woven fabric layer 301 was disposed on the first epoxy resin layer 4. However, a layer different from the vulcanizing adhesive and the woven fabric may be disposed on the first epoxy resin layer 4, and the IC tag may be attached to the rubber product G via the layer. As described above, the second surface 4B of the first epoxy resin layer 4 has less unevenness than the upper surface of the inlay 101, so that various layers can be formed on the first epoxy resin layer 4. The same applies to the second epoxy resin layer 204, and a layer different from the vulcanizing adhesive and the woven fabric may be disposed on the second epoxy resin layer 204, and the IC tag may be attached to the rubber product G via the layer.

[0067] <4-3> In the first and second embodiments, the epoxy resin layer 4, 204 and the vulcanization adhesive layer 5, 205 are integrated in advance before vulcanization of the rubber product G. However, the epoxy resin layer 4, 204 and the vulcanization adhesive layer 5, 205 may be integrated simultaneously with vulcanization by heat during vulcanization.

[0068] <4-4> In the above embodiment, the base sheet 1 is made of polyimide, but it may be made of other materials, for example, PET (polyethylene terephthalate) is preferably used. EXAMPLES

[0069] Examples of the present invention will be described below, but the present invention is not limited to the following examples.

[0070] IC tags according to Examples 1 to 5 shown in the table of Fig. 6 and IC tags according to Comparative Examples 1 to 7 shown in the table of Fig. 7 were manufactured. Specifically, first, two types of base sheets were prepared: a polyamide (PI) film and a PET film. The PET film was used only in Example 5, and a PI film was used in the other examples. Then, an antenna and an IC chip as shown in Fig. 2 were mounted on one surface of these base sheets (hereinafter referred to as the circuit mounting surface) by the method described in the above embodiment.

[0071] For Examples 1 to 5 and Comparative Example 1, an epoxy resin sheet (thermosetting epoxy resin) was superimposed on the surface of the base sheet carrying the antenna and IC chip (hereinafter referred to as the circuit mounting surface), and a vacuum press was used to perform heat pressing for 40 minutes using a heating plate heated to 160°C to adhere the epoxy resin sheet to the circuit mounting surface of the base sheet, thereby forming an epoxy resin layer.

[0072] Next, in Examples 1 to 4, a liquid vulcanizing adhesive was applied to the epoxy resin layer with a brush to form a vulcanizing adhesive layer. In Example 5, a canvas was placed on the epoxy resin layer, and the canvas was further recoated with a chloroprene rubber solvent. In Comparative Examples 2 and 3, a liquid adhesive was applied to the circuit mounting surface of the PI film with a brush to form an adhesive layer. In Comparative Examples 4 and 5, a liquid vulcanizing adhesive was applied to the circuit mounting surface of the PI film with a brush to form a vulcanizing adhesive layer. In Comparative Examples 6 and 7, a liquid primer was applied to the circuit mounting surface of the PI film with a brush to form a primer layer, and a liquid vulcanizing adhesive was further applied to the primer layer with a brush to form a vulcanizing adhesive layer. The manufacturers' names and model numbers of the vulcanizing adhesive, adhesive, and primer used here are as shown in the tables of FIG. 6 and FIG. 7. The primer used in Comparative Examples 6 and 7 is a primer recommended by the manufacturer to be used together with the vulcanizing adhesive used in Comparative Examples 6 and 7.

[0073] Next, the IC tags of Examples 1 to 5 and Comparative Examples 1 to 7 manufactured as described above were attached to a rubber sheet of unvulcanized natural rubber, and in this state, the unvulcanized rubber sheet and the IC tag were vulcanized and integrated. At this time, the surface of the rubber sheet to which the IC tag was attached was the surface opposite to the base sheet, as shown in the layer structure in the tables of Figures 6 and 7. The vulcanization conditions regarding temperature and time were as shown in the tables of Figures 6 and 7.

[0074] The IC tagged rubber sheets according to Examples 1 to 5 and Comparative Examples 1 to 7 manufactured by the above procedure were each 125 cm square. Five samples measuring 25 mm x 125 mm were cut out from this sheet. At this time, the antenna and IC chip patterns in each sample were made to be the same. Of the five samples cut out from one IC tagged rubber sheet, the left and right samples were not used in the following tests because the film was sometimes misaligned due to the flow of rubber during vulcanization, and only the three samples in the center were used for the tests.

[0075] The samples according to Examples 1 to 5 and Comparative Examples 1 to 7 cut out as described above were subjected to a 180° peel test according to JIS K 6256-1 to measure the strength of the adhesive surface. The number of samples in each of Examples 1 to 5 and Comparative Examples 1 to 7 was all three. That is, for each of Examples 1 to 5 and Comparative Examples 1 to 7, three samples cut out from the same rubber sheet with an IC tag were used. In the 180° peel test, the upper part of the sample (the part where the IC chip and antenna were not arranged) was held by the chuck of a tensile tester, and the adhesive surface was peeled off by pulling so that the peeling direction was 180° to the adhesive surface. Then, the average peel force during peeling was measured, and the smallest average peel force among the three samples for each example was taken as the peel force for that example. The results are shown in the tables of FIG. 6 and FIG. 7. The tables of FIG. 6 and FIG. 7 also show the percentage of the position in the layer direction where peeling occurred as the destruction mode. For example, in Example 1, the failure mode is shown as "FE70 / A30," which means that 70% peeling occurred at the interface between the base sheet (F) and the epoxy resin layer (E) and 30 percent peeling occurred within the vulcanized adhesive layer (A).

[0076] The results of Fig. 6 and Fig. 7 show that the peel strength is larger in Examples 1 to 5 than in Comparative Examples 1 to 7. That is, from the results of the above peel test, it was confirmed that the adhesion between the base sheet and the rubber sheet is improved by interposing an epoxy resin layer and a vulcanized adhesive layer or a woven fabric layer between the base sheet and the rubber sheet. In particular, when comparing Example 3 and Comparative Example 6, Comparative Example 6 differs from Example 3 only in that a primer recommended by the manufacturer was used instead of an epoxy resin layer. However, there was a large difference in adhesion, and the superiority of the Examples was confirmed. [Explanation of symbols]

[0077] 100, 200, 300 IC tags 101 Inlay 1 Base sheet 1A 1st page 1B 2nd side 2. IC chip 3 Antennas 31 Impedance matching section 32 Dipole section 4. First epoxy resin layer 4A 1st page 4B 2nd side 204 Second epoxy resin layer 204A 1st page 204B 2nd page 5 First vulcanized adhesive layer 205 Second vulcanized adhesive layer 301 1st woven fabric layer 302 2nd woven fabric layer 20. Laura G Rubber products

Claims

1. An IC tag that is attached to a rubber product and used, A base sheet having a first surface and a second surface; An IC chip disposed on the first surface of the base sheet; a first epoxy resin layer disposed on the first surface of the base sheet so as to cover the IC chip; An IC tag comprising:

2. a second epoxy resin layer disposed on the second surface of the base sheet; Further comprising: The IC tag according to claim 1.

3. a first vulcanizing adhesive layer disposed on the surface of the first epoxy resin layer opposite to the base sheet; Further comprising: The IC tag according to claim 1 or 2.

4. a first woven fabric layer disposed on the surface of the first epoxy resin layer opposite to the base sheet; Further comprising: The IC tag according to claim 1 or 2.

5. a first vulcanizing adhesive layer disposed on a surface of the first epoxy resin layer opposite to the base sheet; a second vulcanized adhesive layer disposed on a surface of the second epoxy resin layer opposite to the base sheet; Further comprising: The IC tag according to claim 2.

6. a first woven fabric layer disposed on a surface of the first epoxy resin layer opposite to the base sheet; a second woven fabric layer disposed on a surface of the second epoxy resin layer opposite to the base sheet; Further comprising: The IC tag according to claim 2.

7. The base sheet is made of polyimide. The IC tag according to claim 1 or 2.

8. Preparing the IC tag according to claim 3; Providing unvulcanized rubber; vulcanizing the unvulcanized rubber in a state where the unvulcanized rubber is in contact with the first vulcanization adhesive layer contained in the IC tag, thereby producing a rubber product having the IC tag attached thereto; A method for producing a rubber product comprising the steps of:

9. Preparing the IC tag according to claim 4; Providing unvulcanized rubber; vulcanizing the unvulcanized rubber in a state where the unvulcanized rubber is in contact with the first woven fabric layer included in the IC tag, thereby manufacturing a rubber product to which the IC tag is attached; A method for producing a rubber product comprising the steps of:

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