JP2006178638A - Metallic material corresponding to ic tag, ic tag corresponding to metal, metallic container corresponding to ic tag, and method for manufacturing the metallic material corresponding to ic tag - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain accurate radio communication in a communication range originally suitable to an existing IC tag without requiring any specific constitution or the like only for a metal on the tag side. <P>SOLUTION: A metallic material 10 to which an IC tag 20 for performing radio communication between a reader and a writer is to be attached is provided with: a metallic layer 11 which is a base material; a resin layer 13 laminated on the metallic layer 11 and consisting of a thermoplastic such as a PET resin for separating the IC tag 20 from the metallic layer 11; an electromagnetic wave shielding layer 14 laminated on the resin layer 13 and consisting of an electromagnetic wave shielding coating material containing a metal oxide material for interrupting the passage of a magnetic field of the IC tag up to the metallic layer 11; and a cavity layer 15 laminated on the electromagnetic wave shielding layer 14 and consisting of nonwoven fabric for further separating the IC tag 20 from the metallic layer 11: and constituted so that the IC tag 20 is mounted on the cavity layer 15. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a metal material that serves as a base material for a metal container such as an aluminum can, a steel can, or a pouch container, and more particularly to an IC tag-compatible metal material to which an IC tag that performs wireless communication with a reader / writer can be attached. And an IC tag-compatible metal container made of the metal material and a method for producing the metal material.

Generally, metal containers such as aluminum cans and steel cans are, for example, carbonated drinks such as beer, cola, cider, fruit juice drinks, containers for various teas, containers for canned foods, containers for various liquid products, etc. Widely used.
In addition, pouch containers made of packaging materials in which a metal layer such as an Al foil is laminated on a soft packaging material such as a resin film are lightweight, flexible, durable, gas barrier properties, etc., easy to process and can be manufactured at low cost. It is widely used as a container for mainly liquid products such as detergents and cosmetics as well as food and beverages.
Such various metal containers are provided with characters, bar codes, or the like displaying predetermined product information such as product names, contents components, producers, production locations, expiration dates, and the like. This kind of product information display is usually printed directly on the outer surface of a metal container or printed on a label.

However, labels and prints for displaying product information are generally displayed small so as not to impair the design of the container. As a result, the display area, the size of characters to be displayed, the number of characters, etc. are limited. There was a problem that sufficient product information could not be displayed.
In the case of bar code display, the bar code itself must be displayed in a flat shape on the surface of the container in order to be read by a reader. Since the amount of information that can be encoded with a code is limited, there is a certain limit as a means for displaying and recognizing product information, as in the case of display by characters.

Therefore, as a means for eliminating such disadvantages and inconveniences of conventional product information display and displaying necessary and sufficient product information simply and accurately, an IC tag has recently been used.
An IC tag is also called a non-contact IC tag, an RFID (Radio Frequency Identification) tag, etc., and is an ultra-small communication terminal in which an IC chip and a radio antenna are sealed with resin, glass, etc. and formed into a tag (tag) shape. , Record predetermined information on the IC chip, attach a tag to the object, and pick up the recorded information on the reading device (reader / writer) side by wireless communication to recognize and display the information recorded on the IC chip To do.

Such an IC tag can record hundreds of bytes of data in the memory of the IC chip, can record sufficient information, etc., and is non-contact with the reader side, so that the contact is worn, scratched, dirty, etc. In addition, since the tag itself can be powered off, it can be processed according to the object and can be made smaller and thinner.
By using such an IC tag, various information related to the product, such as the name and weight of the product, the content, the name of the manufacturer / seller, the manufacturing location, the date of manufacture, the expiration date / expiration date, etc. Information can be recorded, and even a wide variety of product information that was impossible with conventional product display using characters and barcodes can be used simply by attaching a small and thin tag to the product. It became possible.

However, when such an IC tag is attached to a metal container such as an aluminum can, a steel can or a pouch container, the IC tag is affected by the conductivity of the metal container, and accurate wireless communication cannot be performed. There has occurred.
When the IC tag is attached to the container, the magnetic flux generated by the IC tag is generated in a direction penetrating the container. For this reason, when a tag is attached to a metal container, a heat loss or the like in which a magnetic wave / electromagnetic wave generated by the antenna unit is absorbed to the metal container side occurs, and the communication characteristics of the tag are impaired.

For example, as shown in FIG. 7A, when the IC tag 120 is attached to the metal container 110, an eddy current is induced on the surface of the metal container 110 by the magnetic flux generated by the tag 120 as shown in FIG. 7B. The eddy current cancels out the magnetic flux of the IC tag 120 and causes heat loss. In addition, the inductance of the antenna coil portion of the tag 120 changes due to the influence of the metal container 110, which causes resonance of the resonance circuit of the antenna. The frequency will also shift.
In this way, when a general-purpose IC tag that is generally used is attached to a metal container as it is, a problem occurs that the tag malfunctions or wireless communication with a reader / writer cannot be performed.

So far, when attaching an IC tag to a metal container such as an aluminum can or a steel can, a proposal to change the configuration of the IC tag to a dedicated one for the metal container to avoid the influence from the metal container (For example, refer to Patent Documents 1-3.)
Specifically, as shown in FIG. 8, a conventionally proposed IC tag 220 dedicated to a metal container has a magnetic body (high magnetic permeability) formed in a sheet shape or the like on the side facing the metal container 110 inside the tag. Body) 221 and a dielectric are arranged, thereby preventing the magnetic flux generated by the IC tag 220 from passing through the magnetic body 221 and preventing an eddy current from being generated on the metal container 110 side. It was like that.

JP 2002-207980 (page 2-4, FIG. 1) Japanese Unexamined Patent Publication No. 2004-127057 (page 3-4, FIG. 1) JP 2004-164055 A (page 4-5, FIG. 1)

However, the conventionally proposed IC tag for a metal container is designed and configured only for metal, and the existing IC tag cannot be used for a metal container.
That is, it has not solved the problem when a general-purpose tag is used for a metal container.

In addition, the IC tag configured exclusively for metal in this way has a complicated configuration in which a magnetic material and a dielectric material are arranged inside, and the tag becomes larger and heavier, and is small and thin. There also arises a problem that the maximum advantage of the light weight IC tag is impaired.
IC tags can be used as a wireless communication means with low cost, small size, light weight and large storage capacity only by using inexpensive and mass-produced general-purpose tags. Dedicated large and complex tags have significantly reduced the merits of such general purpose tags.

  The present invention has been proposed in order to solve the problems of the conventional techniques as described above, and a general-purpose IC tag can be used as it is, not by a change on the IC tag side but by a correspondence on the metal container side, In addition, an IC tag compatible metal material that enables accurate wireless communication within the proper proper communication range of the IC tag without impairing the communication characteristics of the tag, a metal compatible IC tag, an IC tag compatible metal container, and an IC tag compatible metal An object is to provide a method for manufacturing a material.

In order to achieve the above object, an IC tag-compatible metal material according to the present invention is a metal material to which an IC tag that performs wireless communication with a reader / writer is attached, A metal layer, an electromagnetic wave shielding layer that does not allow the magnetic field of the IC tag to pass to the metal layer, and a distance layer that separates the IC tag from the metal layer.
Further, as described in claim 2, the metal material corresponding to the IC tag of the present invention further includes a second distance layer made of a material different from the distance layer, which separates the IC tag from the metal layer.

According to the IC tag-compatible metal material of the present invention having such a configuration, an electromagnetic wave shielding layer that does not allow the magnetic field of the IC tag to reach the metal material on the metal layer that is the base material of the metal container, and the IC tag from the metal layer By laminating the distance layer to be separated and, if necessary, the second distance layer, it is possible to reliably prevent the heat loss of the communication gain and the resonance frequency from being shifted by the influence of the metal.
As a result, any existing IC tag can be attached to the metal container of the present embodiment to perform accurate wireless communication within the proper communication range of the tag.

That is, by providing an electromagnetic wave shielding layer made of an electromagnetic wave shielding paint or the like, generation of eddy current generated on the metal container side can be suppressed, and a cavity made of nonwoven fabric or the like as a distance layer separating the IC tag from the metal layer By providing a resin layer made of a layer or PET resin, the IC tag can be sufficiently separated from the metal layer to prevent changes in the inductance of the IC tag due to the influence of the metal container, and the resonance frequency of the IC tag antenna It is possible to effectively prevent the deviation.
As a result, no matter what IC tag is attached to the metal material of the present invention, the communication gain of the IC tag can be secured satisfactorily, and accurate wireless communication is possible. Can be used as is.

Specifically, the metal material corresponding to the IC tag of the present invention is configured such that the distance layer or the second distance layer is a hollow layer made of a nonwoven fabric or a foamed resin.
According to the IC tag-compatible metal material of the present invention having such a configuration, a hollow layer such as a nonwoven fabric or a foamed resin can be laminated as a distance layer (or a second distance layer) for separating the IC tag from the metal layer. it can.
In order to reduce the influence of the metal layer on the IC tag, it is ideal that the effective relative dielectric constant is 1.0 (air), but this means that the IC tag is levitated in the air, It is impossible in reality.

If the nonwoven fabric is a nonwoven fabric made of, for example, a PET resin, a large number of cavities are formed inside, so that the effective relative dielectric constant can be made smaller than that of the PET resin itself, and can be set to a value closer to 1.0, It is optimal as a material constituting a cavity layer that separates the IC tag from the metal layer. Similarly, in the case of foamed resin, the inside is filled with gas such as air, nitrogen, carbon dioxide, etc., and the effective relative dielectric constant can be made a value close to 1.0.
Further, the feature of the nonwoven fabric and the foamed resin is the degree of design freedom, and a hollow layer having a desired thickness and size can be formed easily and at low cost.

Therefore, in the present invention, a non-woven fabric or a foamed resin is used as a distance layer that separates the IC tag from the metal layer, thereby reducing a resonance frequency shift and heat loss caused by the metal caused when the IC tag contacts and approaches the metal. It can be effectively prevented.
From the same viewpoint, in addition to non-woven fabric and foamed resin, for example, a resin coating can be applied in a lattice shape to form a cavity layer having a cavity inside, and this is employed as the cavity layer of the present invention. You can also.

Further, in the metal material corresponding to the IC tag of the present invention, the second distance layer or the distance layer is a resin layer made of a thermoplastic plastic containing polyester, polyethylene, polypropylene, and polyamide. As a configuration.
According to the metal material corresponding to the IC tag of the present invention having such a structure, the distance layer (or the second distance layer) that separates the IC tag from the metal layer by coating the metal layer with a plastic such as PET resin. ) Can be formed.

The resin layer made of PET resin or the like can be formed in a layer shape having a predetermined thickness on the surface of the metal layer. With this resin layer, the IC tag does not directly contact the metal layer but only the thickness of the resin layer. It will be separated from the metal layer.
Also, PET resin has an effective dielectric constant of about 2.7, which is sufficiently small compared to other materials, and since the PET resin is interposed between the metal layer and the IC tag, the inductance on the IC tag side Etc. can also be suppressed.
Accordingly, it is possible to effectively prevent the deviation of the resonance frequency caused by the IC tag coming into contact with or close to the metal and the heat loss due to the metal.
In addition, a resin layer such as a PET resin can be quickly formed by laminating a resin layer having a desired thickness by a simple process. Therefore, a resin layer having a suitable thickness corresponding to the output and frequency characteristics of an IC tag to be used is provided. It is possible to provide a metal material easily and at low cost.

Here, in the field of metal containers such as aluminum cans and steel cans, a resin-coated can container in which a metal serving as a base material is coated with a plastic resin such as a PET resin may be used. Such resin-coated can containers are much less waste and energy consumed in the can-making process than ordinary can containers, and can be manufactured at low cost and resource saving. It is known as an excellent can container.
In the case of a pouch container, for example, a multilayer film in which a metal layer (aluminum layer) serving as a base material is an intermediate layer, an outer layer is a polyethylene terephthalate (PET) layer, an inner layer is an unstretched polypropylene (CPP) layer, etc. used.
The metal material of the present invention is a metal material of such a resin-coated can container or pouch container by laminating a plastic such as PET resin on the metal layer as a resin layer that becomes a distance layer for separating the IC tag from the metal layer. Can be used as

Further, in the metal material corresponding to the IC tag of the present invention, the electromagnetic wave shielding layer is made of a metal oxide material as described in claim 5.
Specifically, as described in claim 6, the metal oxide material can be made of Mn—Zn, Ni—Zn, or Mg—Zn based soft ferrite.
According to a seventh aspect of the present invention, the metal oxide material can be made of a magnetic material containing flakes or particles of Al, C, Cu, Ag, Nb, Co, Cr, or Pd.

According to the IC tag-compatible metal material of the present invention having such a configuration, any metal oxide material can be selected and used as an electromagnetic wave shielding layer that does not allow the magnetic field of the IC tag to pass through the metal layer.
As a result, it is possible to set an electromagnetic wave shielding layer with suitable permeability corresponding to the output and frequency characteristics of the IC tag to be used, and provide an IC tag-compatible metal material excellent in versatility and expandability. can do.

Moreover, the metal material corresponding to the IC tag of the present invention is configured such that the electromagnetic wave shielding layer is laminated on the surface of the metal layer by application.
According to the IC tag-compatible metal material of the present invention having such a structure, the electromagnetic wave shielding paint is applied to the surface of the metal layer (or the surface of the distance layer in the case of the metal layer in which the distance layers are laminated). A layer can be formed.
In particular, by applying an electromagnetic wave shielding paint only to the mounting part to which the IC tag is attached, an electromagnetic wave shielding layer having an arbitrary size and shape on an arbitrary part of the metal material in accordance with the size or mounting part of the IC tag to be used. Can be formed easily and rapidly.
On the other hand, for example, when an IC tag is later attached to a can product at a retail store, the IC tag is randomly attached to an arbitrary part of a metal container, so an electromagnetic shielding paint is applied to the entire metal material. To form an electromagnetic wave shielding layer.
As a result, it is possible to realize a metal material with high versatility and high expandability that can be used for any IC tag at low cost.

  On the other hand, the metal-compatible IC tag according to the present invention includes an IC chip, an antenna, and a base material on which the IC chip and the antenna are mounted. The IC tag performs wireless communication with a writer, and the base material includes a distance layer that separates the IC chip and the antenna from the metal material.

Thus, in the present invention, a distance layer for separating the IC tag from the metal material can be provided on the IC tag side. The distance layer provided in the IC tag can be formed of a non-woven fabric or foamed resin similarly to the distance layer provided in the metal material described above, and the distance layer can be formed on the IC tag easily and at low cost.
In particular, in consideration of productivity, it is advantageous to provide the distance layer on the IC tag side, enabling accurate wireless communication within the proper communication range of the tag without impairing the communication characteristics of the tag. The features of the present invention can be realized at a lower cost and with higher productivity.

And the metal container corresponding to IC tag of this invention is a metal container which can accommodate the content inside, as described in Claim 10, Comprising: All or one part of a container is Claims 1-9. The structure is made of a metal material corresponding to the described IC tag.
Thus, the metal container corresponding to the IC tag of the present invention can form an arbitrary metal container such as an aluminum can, a steel can, a pouch container or the like using the metal material according to the present invention.
The metal container can be formed entirely of the metal material according to the present invention, or can be formed by using the metal material only in the portion of the container where the IC tag is mounted.
In this way, according to the present invention, an IC that can satisfactorily ensure the communication gain of an IC tag, regardless of what IC tag is attached to a metal container of any shape, size, application, etc. It can be provided as a compatible metal container.

The method for producing a metal material corresponding to an IC tag of the present invention is a method for producing a metal material to which an IC tag for performing wireless communication with a reader / writer is attached. The method includes a step of laminating an electromagnetic wave shielding layer that does not allow the magnetic field of the IC tag to pass through to the metal layer on all or part of the surface of the metal layer as a material, and the electromagnetic wave shielding layer is laminated by applying an electromagnetic wave shielding paint. There is a way.
Furthermore, as described in claim 12, the method for producing a metal material corresponding to an IC tag of the present invention further includes a step of laminating a distance layer for separating the IC tag from the metal layer on the surface of the electromagnetic wave shielding layer, The distance layer is a method of laminating by applying a resin paint.

According to such a method for producing a metal material corresponding to an IC tag of the present invention, an electromagnetic wave shielding layer is formed by applying an electromagnetic wave shielding paint to any part of the surface of the metal layer or the distance layer laminated on the metal layer. be able to.
In addition, the distance layer can be formed by applying a resin paint to any part of the surface of the electromagnetic wave shielding layer. The distance layer can be formed as a cavity layer having a cavity inside by applying a resin coating in a lattice pattern.
Accordingly, an electromagnetic wave shielding layer and a distance layer having an arbitrary size and shape can be easily and quickly applied and formed on an arbitrary part of the metal material in accordance with the size and mounting part of the IC tag to be used. In particular, by applying an electromagnetic wave shielding paint or a distance layer only to the mounting portion to which the IC tag is attached, a metal material that can be used for any IC tag can be provided at low cost.

According to the metal material corresponding to the IC tag of the present invention, any existing IC tag can be used by being attached to a metal container without requiring a special configuration for metal countermeasures on the tag side. Therefore, accurate wireless communication within the proper communication range of the tag is possible.
As a result, the original good communication characteristics of the IC tag can be obtained even when used for various metal containers without any loss of the advantages of a general-purpose IC tag that is small, thin, and lightweight. A metal container suitable for a steel can, a pouch container or the like can be provided.

Hereinafter, preferred embodiments of a metal material corresponding to an IC tag according to the present invention, a metal IC tag, a metal container made of a metal material corresponding to an IC tag, and a method for producing the metal material will be described with reference to the drawings.
[Metal materials]
1A and 1B are perspective views schematically showing a main part of a metal material corresponding to an IC tag according to an embodiment of the present invention. FIG. 1A shows a state before the IC tag is mounted, and FIG. 1B shows an IC tag. The mounted state is shown.
As shown in FIG. 1, a metal material 10 according to this embodiment is a metal material to which an IC tag 20 that performs wireless communication with a reader / writer (not shown) is attached, and is a metal layer serving as a base material. 11, a container inner surface layer 12 and a resin layer 13 laminated on both surfaces of the metal layer 11, an electromagnetic wave shielding layer 14 laminated on the resin layer 13, and a cavity layer 15 laminated on the electromagnetic wave shielding layer 14, The IC tag 20 is mounted on an arbitrary portion of the hollow layer 15.

[Metal layer]
The metal layer 11 is a base material for a metal container such as an aluminum can, a steel can, or a pouch container, and is made of an arbitrary metal material formed in a plate shape.
As this metal layer 11, arbitrary metals can be selected according to the use of metal materials, such as Al, copper, iron, steel, silver, gold, etc., for example.
The thickness of the metal layer 11 is, for example, a container formed of the metal material 10 from a deposited metal layer of several nanometers for a pouch container to a metal plate of several millimeters for an aluminum can or a steel can. It can be set to any thickness depending on the use and size of the product.
A container inner surface layer 12 and a resin layer 13 are laminated on both surfaces of the metal layer 11, respectively.

[Container inner layer]
The container inner surface layer 12 is a layer constituting the inner surface of the container when a can container or the like is formed of the metal material 10, and is formed of, for example, a PET resin layer.
In can containers such as aluminum cans and steel cans, a resin-coated can container in which a plastic layer such as a PET resin is coated on a metal layer serving as a base material may be used. In the case of a pouch container, a base material may be used. A multilayer film having an aluminum layer as an intermediate layer, an outer layer as a polyethylene terephthalate (PET) layer, an inner layer as an unstretched polypropylene (CPP) layer, and the like is used.
The container inner surface layer 12 becomes a resin layer inside the container in such a resin-coated can container or a pouch container.
Therefore, when the metal material 10 is not used as a base material for a resin-coated can container or a pouch container, the container inner surface layer 12 can be appropriately omitted.
In addition, it is preferable from the point of efficiency of a manufacturing process and manufacturing cost that the container inner surface layer 12 is laminated | stacked simultaneously with the resin layer 13 with the same material as the resin layer 13 mentioned later.

[Resin layer]
The resin layer 13 is laminated on the surface of the metal layer 11 opposite to the container inner surface layer 12 described above, and a distance layer (or second layer) for separating the IC tag 20 mounted on the metal material 10 from the metal layer 10. The distance layer is formed of PET resin or the like.
Specifically, the resin layer 13 is formed of a thermoplastic plastic such as polyester, polyethylene, polypropylene, or polyamide.
A resin layer such as PET can be formed on the surface of the metal layer 11 with a predetermined thickness, and the resin layer is separated from the metal layer 11 by the thickness of the resin layer without directly contacting the IC tag 20 with the metal layer 11. Can be made. Moreover, the effective relative dielectric constant of PET resin is about 2.7, which is a sufficiently small value compared with other substances, and the interposition of the PET resin between the metal layer and the IC tag allows the IC tag side. Changes in inductance and the like can be sufficiently suppressed.
Therefore, by providing the resin layer 13 made of PET resin or the like, the IC tag 20 can be sufficiently separated from the metal layer 10, and the resonance frequency shift caused when the IC tag 20 contacts and approaches the metal layer 11. And heat loss due to the metal layer 11 can be effectively prevented.

The resin layer 13 is formed by laminating the both surfaces of the metal layer 11 together with the above-described container inner surface layer 12 with, for example, a thermoplastic polyester resin film.
The thermoplastic polyester resin can be, for example, a copolymer or blend having polyethylene terephthalate or polybutylene terephthalate as a main component and having a melting point of about 200 to 260 ° C. The thickness of the polyester resin film is Usually about 5 to 40 μm.

Here, the thermoplastic polyester-based resin coating is an amorphous and non-cooled material that is rapidly cooled after heat bonding by extrusion lamination method, unstretched cast film laminating method, or the like on both sides of a belt-like metal plate (metal layer 11). A stretched one is preferred. The non-stretched, amorphous thermoplastic polyester resin film is excellent in stretchability and adhesion, and can be peeled off or stretched by thinning the metal layer 11 serving as a base material. It is possible to follow without causing damage such as cracks.
The resin layer 13 (and the container inner surface layer 12) may be a single layer (one layer) or may be a multilayer such as two layers or three layers. In the case of multiple layers, the stretched film can be formed by bonding through thermal bonding or an adhesive layer.

Further, the resin layer 13 may be omitted as appropriate.
As will be described later, the metal material 10 of the present embodiment is provided with a cavity layer 15 as a distance layer that separates the IC tag 20 from the metal layer 11. The resin layer 13 becomes a second distance layer. Therefore, if the IC tag 20 is sufficiently separated from the metal layer 11 by the hollow layer 15 and good communication characteristics can be obtained, the resin layer 13 serving as the second distance layer can be omitted. The same applies when the cavity layer 15a is provided on the IC tag 20 side (see FIG. 2). Of course, by providing the resin layer 13 together with the cavity layer 15, the IC tag 20 is further sufficiently separated from the metal layer 11 by the distance layer and the second distance layer. Both may be provided side by side.

[Electromagnetic wave shielding layer]
The electromagnetic wave shielding layer 14 is a layer that is laminated on the resin layer 13 and does not allow the magnetic field of the IC tag 20 to pass to the metal layer 11. When the cavity layer 15 described later is omitted, the IC tag 20 is mounted on the electromagnetic wave shielding layer 14.
The electromagnetic wave shielding layer 14 is made of a metal oxide material, and specifically can be made of Mn—Zn, Ni—Zn, or Mg—Zn soft ferrite. Moreover, it can comprise with the magnetic material containing the flake or particle | grains of Al, C, Cu, Ag, Nb, Co, Cr, or Pd.
As described above, in this embodiment, any metal oxide material can be selected and used as the electromagnetic wave shielding layer 14 that does not allow the magnetic field of the IC tag 20 to pass through the metal layer 11. The electromagnetic wave shielding layer 14 having suitable permeability corresponding to the frequency characteristics can be formed.

The electromagnetic wave shielding layer 14 composed of the components as described above is an electromagnetic wave shielding paint such as a conductive paint applied to the surface of the resin layer 13 in which the metal oxide material is liquefied. That is, the electromagnetic wave shielding layer 14 is laminated on the surface of the resin layer 13 by applying a paint. Thereby, the manufacturing process of the electromagnetic wave shielding layer 14 can be performed very easily and rapidly.
In addition, since the electromagnetic wave shielding layer 14 can be formed simply by applying the electromagnetic wave shielding paint in this way, by applying the paint only to the mounting portion to which the IC tag 20 is attached, the size or mounting part of the IC tag 20 to be used is applied. In addition, the electromagnetic wave shielding layer 14 having an arbitrary size and shape can be easily and rapidly applied and formed on an arbitrary part of the metal material 10.
When the IC tag 20 is randomly attached to an arbitrary part of the metal material 10, the electromagnetic wave shielding layer 14 is formed by applying an electromagnetic wave shielding paint to the entire surface of the resin layer 13.

[Creation of electromagnetic wave shielding paint]
As a method for producing the electromagnetic wave shielding paint, magnetic powder such as Fe-Si can be mixed with a resin solvent such as varnish, primer, epoxy and the like. The magnetic powder is preferably flaky, but may be powder. Also, magnetic flakes and powder may be mixed.
The major axis of the flat shape of the magnetic flakes used is preferably, for example, in the range of 15 μm to 40 μm. In the case of magnetic powder, the particle diameter is preferably in the range of 15 μm to 30 μm.
As the solvent, an oily or water-based paint can be used, and there is no particular limitation such as a heat drying type or a UV curing type.
The mixing ratio of the magnetic substance and the solvent is preferably in the range of 40% to 75% in consideration of the electromagnetic wave shielding effect and the viscosity applicable to the metal.

[Method of applying electromagnetic shielding paint]
A bar coater, roll coat, brush, or the like can be used to apply the electromagnetic wave shielding paint to the metal. In addition, the paint may be applied directly to the metal. However, in consideration of adhesion, it is preferable to apply an electromagnetic wave shielding paint on the metal after applying an adhesive such as a primer on the metal.
Alternatively, electromagnetic wave shielding paint and varnish, primer, resin, or the like may be alternately applied on a metal and laminated. In this case, the uppermost layer is preferably not an electromagnetic wave shielding paint.
The coating thickness of the coating is preferably about 0.1 mm to 1.0 mm, although it depends on the concentration of the magnetic powder in the solvent and the size of the powder. About 5 mm is desirable.

[Cavity layer]
The cavity layer 15 is a layer that is laminated on the electromagnetic wave shielding layer 14 and separates the IC tag 20 from the metal layer 11, and the IC tag 20 is mounted on the cavity layer 15.
The hollow layer 15 can be made of nonwoven fabric, foamed resin, or the like.
In order to reduce the influence of the metal layer 11 on the IC tag 20, it is ideal that the effective relative dielectric constant is 1.0 (air), but this means that the IC tag is levitated in the air. However, it is impossible in reality.

If the nonwoven fabric is a nonwoven fabric made of, for example, a PET resin, a large number of cavities are formed therein, so that the effective relative dielectric constant can be made smaller than that of the PET resin itself, and a value closer to 1.0 can be set. Similarly, in the case of foamed resin, the inside is filled with gas such as air, nitrogen, carbon dioxide, etc., and the effective relative dielectric constant can be made a value close to 1.0.
Further, the feature of the nonwoven fabric and the foamed resin is the degree of design freedom, and it becomes possible to easily and inexpensively form a hollow layer having a desired thickness and size.

Therefore, in this embodiment, a non-woven fabric or a foamed resin is employed as the hollow layer 15 that separates the IC tag 20 from the metal layer 11, thereby causing a resonance frequency shift or metal generated when the IC tag contacts or approaches the metal. The heat loss due to is prevented.
From the same viewpoint, in addition to non-woven fabric and foamed resin, for example, a resin coating can be applied in a lattice shape to form a cavity layer having a cavity inside, and this can be adopted as the cavity layer 15. it can.

The nonwoven fabric can be selected from any material such as synthetic fiber or natural fiber, and the thickness, size, shape, etc. can be arbitrarily set according to the IC tag 20 to be mounted. .
The foamed resin suitable for the cavity layer 15 can be formed by various methods. For example, a method using a foaming agent, a method of injecting air or nitrogen gas when mixing (kneading) a polymer, There are methods using chemical reactions.
The nonwoven fabric and the foamed resin constituting the hollow layer 15 are bonded and laminated on the upper surface of the electromagnetic wave shielding layer 14 laminated on the resin layer 13 by an adhesive or heat fusion.

The cavity layer 15 can be omitted as appropriate when the communication gain of the IC tag is sufficiently secured by the resin layer 13 and the electromagnetic wave shielding layer 14 described above.
Further, as shown in FIG. 1, the cavity layer 15 can be provided not only on the metal material 10 side but also on the IC tag 20 side.
FIG. 2 is a main part perspective view schematically showing a case where a cavity layer 15a is provided on the IC tag 20 side instead of the cavity layer 15 on the metal material 10 side.
As shown in FIG. 2, the cavity layer 15 a included in the IC tag 20 is made of a nonwoven fabric or foamed resin, similar to the cavity layer 15 included in the metal material 10, and the lower surface side of the IC chip and the antenna of the IC tag 20, That is, it is disposed so as to be positioned between the IC chip and antenna and the metal material 10. As a result, the IC tag 20 can be made to function as a distance layer that separates the metal material from the metal material, similarly to the case where the hollow layer 15 is provided on the metal material 10 side. Providing the cavity layer 15a on the IC tag side in this way is advantageous particularly when considering productivity and the like. In the example shown in FIG. 2, the cavity layer 15 a on the IC tag 20 side is provided in place of the cavity layer 15 on the metal material 10 side, but this is provided together with the cavity layer 15 on the metal material 10 side. You may make it do.

[IC tag]
The IC tag 20 includes an IC chip and an antenna. The IC chip and the antenna are mounted on a base material made of resin, glass, or the like and are integrally sealed to form one IC tag.
The IC tag 20 is mounted on the surface of the cavity layer 15 of the metal material 10 described above, as shown in FIG.
When the cavity layer 15 is omitted or when the cavity layer 15a is provided on the IC tag side as shown in FIG. 2, the IC tag 20 is mounted on the surface of the electromagnetic wave shielding layer 14. It has become.

This IC tag 20 can also be mounted on the metal material 10 in advance in the manufacturing process of the metal container formed of the metal material 10, and the manufactured and shipped metal material 10 and the metal container can be later installed. It can also be attached.
At that time, when the IC tag 20 includes the cavity layer 15 a, the IC tag 20 is mounted so that the cavity layer 15 a side contacts the metal material 10.
In the example shown in FIGS. 1 and 2, the IC tag 20 is mounted in advance in the manufacturing process of the metal material 10, and the IC tag 20 mounted on the surface of the cavity layer 15 is further covered with the cover film layer 16. It has come to be.

Here, the IC chip provided in the IC tag 20 is composed of a semiconductor chip such as a memory, and can record, for example, several hundred bytes of data.
Then, reading and writing (data calling / registration / deletion / update etc.) is performed by wireless communication with the reader / writer via the antenna, and the data recorded on the IC chip is recognized.
As data recorded on the IC chip, for example, arbitrary information and data such as product name and weight, content, manufacturer / seller name, manufacturing location, date of manufacture, expiration date can be recorded, Rewriting is also possible. Data can be recorded and rewritten by a dedicated reader / writer.

The frequency band used in the IC tag 20 includes several types of frequency bands such as a band of 135 kHz or less, a 13.56 MHz band, an 860 M to 960 MHz band belonging to a so-called UHF band, and a 2.45 GHz band.
The communication distance that enables wireless communication varies depending on the frequency band used, and the optimum antenna length varies depending on the frequency band.

FIG. 3 is an explanatory view schematically showing the state of communication characteristics when the IC tag 20 is mounted on the metal material 10 shown in FIG. 1, and (a) shows the state of the IC tag mounted on the metal material. (B) has shown the state of the magnetic flux which the IC tag shown to (a) emits.
As shown in the figure, when the IC tag 20 performs wireless communication, a magnetic wave / electromagnetic wave is generated in the antenna coil section. Conventionally, heat loss or the like in which the magnetic wave / electromagnetic wave is absorbed on the metal container side occurs, and the communication characteristics of the tag are impaired. In addition, the inductance of the antenna coil portion has changed due to the influence of the metal container, and the resonance frequency of the antenna has also shifted.
The metal material 10 of the present embodiment can prevent eddy currents and the like from being generated in the metal layer 11 by the electromagnetic wave shielding layer 14 made of an electromagnetic wave shielding paint or the like. Moreover, since the IC tag 20 can be sufficiently separated from the metal layer 11 by providing the resin layer 13 made of PET resin or the like and the cavity layer 15 (or cavity layer 15a) made of nonwoven fabric or the like, the metal layer 11 It is possible to prevent changes in the inductance on the tag side due to the influence of the above, and thereby it is possible to prevent deviation of the resonance frequency of the antenna of the IC tag 20.

FIG. 4 is a graph showing the relationship between the resonance frequency of the IC tag and the intensity of the radio signal when an IC tag having a resonance frequency of 13.65 MHz is mounted on the metal material 10 of the present embodiment and a conventional metal container.
In the figure, a solid line indicates a case where an existing general-purpose tag is attached to the metal material 10 of the present embodiment in which the thickness of the cavity layer 15 (or the cavity layer 15a) is set to 0.5 mm, and the IC tag has a resonance frequency. It is driven with an output of 30 dB or more in the 13.65 MHz band.
A two-dot chain line is a case where an existing general-purpose tag is attached to an existing aluminum can, and the output is greatly reduced to about 15 dB, and the resonance frequency of the tag is also shifted.

An alternate long and short dash line is a case where an existing general-purpose tag is attached to the metal material 10 of the present embodiment in which the thickness of the cavity layer 15 (or the cavity layer 15a) is set to 0.1 mm, and an output of about 25 dB is secured. However, the resonance frequency of the tag shifts to the 13.4 MHz band.
A broken line is a case where a tag is attached on a general-purpose electromagnetic shielding material having a magnetic body (high permeability body) such as a ferrite sheet inside, and the output is secured about 25 dB, but the resonance frequency of the tag is 13 It has shifted greatly to 3MHz band.
As described above, the metal material 10 of the present embodiment is used, and the thickness of the cavity layer 15 is set to an optimum value, so that the original communication characteristics can be ensured satisfactorily even with an existing general-purpose tag. It becomes possible to use for etc.

[Production method]
Next, the manufacturing method of the metal material 10 of this embodiment as described above will be described.
In the metal material 10, first, a plastic resin such as a PET resin is laminated on the surface of the metal layer 11 serving as a base material to form a container inner surface layer 12 and a resin layer 13.
Next, the electromagnetic wave shielding layer 14 is formed by applying the electromagnetic wave shielding paint made of the above-described metal oxide material to the surface of the resin layer 13 laminated on the metal layer 11.
At this time, the electromagnetic wave shielding coating applied to the resin layer 13 can be applied to the entire surface of the resin layer 13, or can be applied only to the portion where the IC tag 20 is mounted.
Thereafter, a hollow layer 15 made of a nonwoven fabric is laminated on the portion where the electromagnetic wave shielding paint is applied. The non-woven fabric is fixed to the surface of the electromagnetic wave shielding layer 14 by means such as adhesive or heat fusion so as not to peel off.
The cavity layer 15 can also be formed by applying a resin paint on the surface of the electromagnetic wave shielding layer 14. That is, the cavity layer 15 having a cavity inside can be formed by applying a resin paint in a lattice shape to any part of the surface of the electromagnetic wave shielding layer 14.
The metal material 10 of this embodiment is completed by the above.

[Metal container]
Next, an example of a metal container formed of the metal material 10 of the present embodiment as described above is shown in FIGS.
The metal container 30 shown in FIG. 5 is an aluminum can or a steel can formed by the metal material 10 of the present embodiment.
Moreover, the metal container 40 shown in FIG. 6 is a pouch container formed of the metal material 10 of this embodiment.
Thus, an arbitrary metal container can be formed using the metal material 10 according to the present embodiment. In addition, the metal container should just be equipped with the metal material 10 of this embodiment about the site | part in which the IC tag 20 is mounted at least. That is, the entire metal container can be formed of the metal material 10 of the present embodiment, but only a part of the metal container (IC tag mounting portion) is formed of the metal material 10, and other parts are, for example, Electromagnetic wave shielding paints and non-woven fabrics can be omitted.

As described above, according to the metal material corresponding to the IC tag according to the present embodiment, the eddy current generated on the metal container side can be suppressed by including the electromagnetic wave shielding layer 14 made of an electromagnetic wave shielding paint or the like. In addition, by providing the resin layer 13 made of PET resin and the like, and further having the hollow layer 15 made of non-woven fabric or the like, the IC tag is separated from the metal layer to prevent a change in inductance of the IC tag due to the influence of the metal container. This can effectively prevent deviation of the resonance frequency of the antenna of the IC tag.
Thereby, no matter what IC tag 20 is attached to the metal container formed of the metal material 10 according to the present embodiment, the communication gain of the IC tag can be ensured satisfactorily, and the original accurate wireless communication of the tag Even existing general-purpose tags can be used as they are.

[Example 1]
Toyo Aluminum Co., Ltd. silicon steel paste RFS54CM (90.5Fe-5.5Si-4Cr, shape: flakes, flake major axis: 20 μm to 30 μm) was mixed in the oil-based paint about 70% to prepare an electromagnetic shielding paint. This paint was applied to the front side of each of the following metal plates using a bar coater so that the paint thickness would be 0.15 mm.

[Metal plate]
Resin-coated metal plate A: Resin-coated metal plate coated with 0.25 mm thick tin-free steel (TFS) on the front side with 20 μm thick polyethylene terephthalate (PET) resin and on the back side with 30 μm thick PET resin ( Thickness 0.3 mm).
Metal plate B: a tin-free steel (TFS) plate having a thickness of 0.3 mm.
Resin-coated metal plate C: a resin-coated metal plate (thickness) coated on an aluminum (AL) plate having a thickness of 0.20 mm with a polyethylene terephthalate (PET) resin having a thickness of 20 μm on the front side and a PET resin having a thickness of 30 μm on the back side 0.25 mm).
Metal plate D: Aluminum (AL) plate having a thickness of 0.25 mm.

[IC tag label]
An IC tag (manufactured by Texas Instruments, operating frequency: 13.56 MHz) was sandwiched between a PET film (film thickness: 45 μm) and a PET non-woven fabric (thickness: about 100 μm), and adhered by a laminator to produce a label.

An IC tag label was attached to each of the metal plates A to D, and a non-woven fabric side was bonded to the metal plate side on a resin-coated metal plate to which a paint was applied to create a metal material with an IC tag.
Table 1 shows the results of a communication test between the reader and the writer using the metal material with an IC tag in a form almost close to contact.

[Comparative Example 1]
The electromagnetic shielding coating is 0.15 mm thick on the TFS plate (metal plate E) having a thickness of 0.3 mm and the aluminum plate (metal plate F) having a thickness of 0.25 mm, which is not coated with resin, as in the example. Then, an IC tag label in which the same IC tag as in Example 1 was sandwiched between PET films (film thickness: 45 μm) was attached.
Table 1 shows the results of a communication test between the reader and the writer using the metal material with an IC tag in a form almost close to contact.

[Example 2]
A metal material with an IC tag was prepared under the same conditions as in Example 1 except that the electromagnetic wave shielding paint was applied so that the paint thickness was 035 mm.
Using this metal material with an IC tag, a communication test between a reader and a writer was performed and the maximum communication distance was measured. The results are shown in Table 2.

[Comparative Example 2]
The electromagnetic shielding coating is 0.35 mm thick on the TFS plate (metal plate E) with a thickness of 0.3 mm and the aluminum plate (metal plate F) with a thickness of 0.25 mm that is not coated with resin, as in the example. Then, an IC tag label in which the same IC tag as in Example 1 was sandwiched between PET films (film thickness: 45 μm) was attached.
Using this metal material with an IC tag, a communication test between a reader and a writer was performed and the maximum communication distance was measured. The results are shown in Table 2.

  As described above, the metal material corresponding to the IC tag of the present invention, the metal container corresponding to the IC tag made of the metal material, and the method of manufacturing the metal material have been described with reference to the preferred embodiments. It goes without saying that the manufacturing method of the container and the metal material is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention.

For example, in the above-described embodiment, a can container or a pouch container used as a beverage or food container has been described as an example of a metal container formed of the metal material of the present invention. However, a container to which the metal material of the present invention can be applied. As for, the use of the container, the contents to be stored, the components of the container, etc. are not particularly limited. That is, as long as it is a metal container, it may be any size, shape, material, etc., and the contents stored in the container may be any.
The metal material of the present invention can also be used as a base material for metal products other than containers, and can be applied to, for example, a housing of an electronic device.

  The IC tag-compatible metal material, metal-compatible IC tag, metal container, and metal material manufacturing method of the present invention described above can be suitably used, for example, in the fields of aluminum cans, steel cans, pouch containers, and manufacturing methods thereof.

BRIEF DESCRIPTION OF THE DRAWINGS It is a principal part perspective view which shows typically the IC tag corresponding | compatible metal material and IC tag which concern on one Embodiment of this invention, (a) is the state before mounting an IC tag, (b) is mounting an IC tag. Shows the state. It is a principal part perspective view which shows typically the IC tag corresponding | compatible metal material and IC tag which concern on other embodiment of this invention, (a) is the state before mounting an IC tag, (b) is an IC tag. The mounted state is shown. It is explanatory drawing which shows typically the state of the communication characteristic at the time of mounting an IC tag in the metal material shown in FIG. 1, (a) is the state of the IC tag mounted in the metal material, (b) is (a ) Shows the state of magnetic flux generated by the IC tag. It is a graph which shows the relationship between the resonant frequency of the IC tag mounted in the IC tag corresponding | compatible metal material which concerns on one Embodiment of this invention, and the intensity | strength of a radio signal. It is a perspective view which shows one Embodiment of the metal container formed with the IC tag corresponding | compatible metal which concerns on this invention, and has shown the case where a metal container is an aluminum can or a steel can. It is a perspective view which shows one Embodiment of the metal container formed with the IC tag corresponding | compatible metal which concerns on this invention, and has shown the case where a metal container is a pouch container. It is explanatory drawing which shows typically the state of the communication characteristic at the time of mounting an IC tag in the conventional general metal container, (a) is the state of the IC tag mounted in the metal container, (b) is ( The state of the magnetic flux which the IC tag shown to a) emits is shown. It is explanatory drawing which shows typically the state of the communication characteristic at the time of mounting the conventional metal exclusive IC tag in a metal container, (a) is the state of the metal exclusive IC tag mounted in the metal container, (b) is The state of the magnetic flux which the metal exclusive use IC tag shown to (a) emits is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Metal material 11 Metal layer 12 Container inner surface layer 13 Resin layer 14 Electromagnetic wave shielding layer 15 Cavity layer 15a Cavity layer 16 Cover film layer 20 IC tag 30 Metal container 40 Metal container

Claims (12)

A metal material to which an IC tag for wireless communication with a reader / writer is attached,
A metal layer as a substrate;
An electromagnetic wave shielding layer that does not allow the magnetic field of the IC tag to pass to the metal layer;
A distance layer separating the IC tag from the metal layer;
A metal material corresponding to an IC tag, comprising: A metal material to which an IC tag for wireless communication with a reader / writer is attached,
A metal layer as a substrate;
An electromagnetic wave shielding layer that does not allow the magnetic field of the IC tag to pass to the metal layer;
A distance layer separating the IC tag from the metal layer;
A second distance layer made of a material different from the distance layer, the IC tag being separated from the metal layer;
A metal material corresponding to an IC tag, comprising:   The metal material corresponding to an IC tag according to claim 1 or 2, wherein the distance layer or the second distance layer is a hollow layer made of a nonwoven fabric or a foamed resin.   The metal material corresponding to an IC tag according to claim 1, 2 or 3, wherein the second distance layer or the distance layer is a resin layer made of a thermoplastic including polyester, polyethylene, polypropylene, and polyamide.   The metal material for an IC tag according to claim 1, wherein the electromagnetic wave shielding layer is made of a metal oxide material.   6. The metal material for an IC tag according to claim 5, wherein the metal oxide material is made of Mn—Zn, Ni—Zn, or Mg—Zn soft ferrite.   6. The metal material for an IC tag according to claim 5, wherein the metal oxide material is made of a magnetic material containing flakes or particles of Al, C, Cu, Ag, Nb, Co, Cr, or Pd.   The metal material for IC tags according to claim 1, wherein the electromagnetic wave shielding layer is laminated on the surface of the metal layer by coating. An IC tag comprising an IC chip, an antenna, and a base material on which the IC chip and the antenna are mounted, attached to a metal material, and performing wireless communication with a reader / writer,
The metal-compatible IC tag, wherein the base material includes a distance layer that separates the IC chip and the antenna from the metal material. It is a metal container that can store the contents inside,
A metal container corresponding to an IC tag, wherein all or part of the container is made of the metal material corresponding to an IC tag according to any one of claims 1 to 9. A method of manufacturing a metal material to which an IC tag for wireless communication with a reader / writer is attached,
A step of laminating an electromagnetic wave shielding layer that does not allow the magnetic field of the IC tag to pass through to the metal layer on all or part of the surface of the metal layer to be a base material;
A method for producing a metal material for an IC tag, wherein the electromagnetic wave shielding layer is laminated by applying an electromagnetic wave shielding paint. A step of laminating a distance layer for separating the IC tag from the metal layer on the surface of the electromagnetic wave shielding layer;
The manufacturing method of the metal material corresponding to an IC tag according to claim 12, wherein the distance layer is laminated by applying a resin paint.

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