JP4402367B2 - Non-contact IC card - Google Patents

Description

【００３６】
表１のように両者の値は、プレスラミネート直後でも既に３倍以上の大きな差がある。さらに、従来技術のカードは、高温度で保存されると顕著に強度低下することが認められる。実際、６Ｎ／ｃｍ以下では、指先で剥離できる程度に弱くなる。それに対し、本願発明のカードでは、９０°Ｃで２４時間保存した後でも十分な剥離強度を維持することが確認できた。
【００３７】
【発明の効果】
上述のように、本発明の非接触ＩＣカードでは、スペーサシートと印刷シートが強固に接着しているので、実使用時に受ける曲げやねじり負荷に対して優れた耐久性を有する。また、スペーサシートの表裏の接着剤層を共押出しして設けるため、重ね合わせするシート数を減らすことができて、材料費と製造コストの低減を図ることができる。なおかつ、アンテナシートの凹凸を吸収するのに十分な接着剤層の厚みが得られる。
プレスラミネート時の加熱温度を高くする必要がないので、印刷インキの色焼けや変色、絵柄の歪みがなく、カード基材が脆く割れ易くなる心配がない。
接着剤層に硬化剤を含有させる場合は、再加熱しても軟化しないため、特に高温環境下の使用においても層間剥離の問題が生じない。
【図面の簡単な説明】
【図１】 本発明のカードの層構成を示す分解断面図である。
【図２】 本発明で使用するアンテナシートの平面図である。
【図３】 図１の層構成をプレスラミネートした後のカードの状態を示す表面側平面図である。
【図４】 図３のカードの断面図である。
【図５】 従来の非接触ＩＣカードの層構成を示す図である。
【符号の説明】
１ 非接触ＩＣカード、リライトカード
３ コイルアンテナ
４ ＩＣチップ
１０ カード基材
１１ アンテナシート
１２ リライトシート
１３，１４ 接着シート
１５，１６ スペーサシート
２０，３０ 印刷シート
２１ おもて面印刷層
３１ 裏面印刷層[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a contactless IC card which encloses an IC chip and an antenna sheet.
In particular, in a non-contact IC card manufactured by laminating and press laminating a plurality of sheets including an antenna sheet, it has excellent appearance quality and delamination strength, and when it has a rewritable recording layer, its printability is improved. IC card is intended.
Therefore, the application field of the present invention relates to the manufacture and application field of non-contact IC cards.
[0002]
[Prior art]
The non-contact IC card includes an antenna sheet (generally sometimes referred to as “inlay”) in which a coil is formed inside the card in order to obtain electric power and signals from the outside in a non-contact manner based on the principle of electromagnetic induction. An IC chip that processes and stores signals to be transmitted and received is used when connected to a coil antenna and integrated with an antenna sheet, and is mounted on a card surface as an IC module with a substrate. May be connected.
In the former case, since the IC chip (which may be modularized) and the coil antenna are both embedded in the card base, the surface smoothness is particularly likely to deteriorate.
The base material of conventional non-contact IC cards is manufactured by press laminating PVC, PET (polyethylene terephthalate) or PET-G, or bonding an adhesive sheet. Attempts have been made to absorb irregularities on the card surface caused by the IC chip or coil antenna by foaming the adhesive sheet or by foaming the adhesive sheet.
[0003]
For example, Patent Document 1 describes forming a foamed resin layer by injection molding a foamed resin on an outer peripheral portion of an IC module, but because it is a limited range of only an outer peripheral portion of an IC module, It is considered difficult to smooth the entire surface of the IC card.
Further, Patent Document 2 discloses a non-contact type IC in which a spacer sheet having a size that fits inside a circle formed by a coil of a coil antenna with an IC chip is inserted and heat-pressed in order to remove air traps contained in the antenna coil. Although the card and its manufacturing method have been proposed, it is considered difficult to absorb the uneven shape of the IC chip.
[0004]
In addition, the previous application (Patent Document 3) by the applicant of the present application uses a biaxially stretched polyethylene terephthalate resin sheet containing fine cavities of 20 to 30% by volume in the IC card substrate as the front and back printed sheets. Propose to do.
In the previous application (Patent Document 4, Patent Document 5), a spacer sheet provided on both sides of the antenna sheet is provided with a through hole that absorbs the thickness of the IC chip, and an adhesive sheet is used between the antenna sheet and the spacer sheet. Proposed to have a symmetrical layer structure.
[0005]
FIG. 5 shows a layer structure of a conventional non-contact IC card.
In this layer configuration, spacer sheets 15 and 16 made of a PET-G resin sheet having a thickness of 180 μm are placed on both sides of the antenna sheet 11 having a thickness of 40 μm, and a biaxially stretched PET (polyethylene terephthalate) sheet having a thickness of 125 μm is placed on the outer surface thereof. The print sheets 20 and 30 are stacked. The antenna sheet 11 and the spacer sheets 15 and 16 are bonded via adhesive sheets 13 and 14 having a thickness of 50 μm.
A through hole 151 is provided in the spacer sheet 15 and a through hole 161 is provided in the spacer sheet 16 to absorb the thickness of the IC chip 4, and the thickness of each sheet on both sides of the antenna sheet 11 is the same, and the base material layer structure is symmetrical. By doing so, the occurrence of warpage is suppressed.
[0006]
[Patent Document 1]
JP-A-6-183190 [Patent Document 2]
JP 2001-109863 A [Patent Document 3]
Japanese Patent Application No. 2002-148596 [Patent Document 4]
Japanese Patent Application No. 2002-148597 [Patent Document 5]
Japanese Patent Application No. 2003-001735 [0007]
[Problems to be solved by the invention]
According to the technique of the previous application (Patent Document 5), the IC chip mounted on the antenna sheet and the protrusion of the antenna can be absorbed to some extent, and the printability when there is a rewrite layer is excellent, There was a tendency for the delamination strength between the printed sheet and the spacer sheet to be insufficient.
That is, since the printed sheet made of stretched PET is not softened at the heating temperature of the press laminate, the adhesion between the two layers is generated solely by the fusion force of the spacer sheet made of PET-G resin having a low softening temperature. For this reason, the adhesion durability of the bonded surface with respect to bending and twisting loads received during actual use is not sufficient, and peeling may occur between the printing sheet and the spacer sheet.
[0008]
As a countermeasure, in addition to the layer structure already filed, an adhesive sheet was also provided outside the spacer sheet (printed sheet side), but the number of sheets to be stacked increased, so the material and manufacturing costs were very high. The problem of becoming.
We also tried to soften the printed sheet made of stretched PET by increasing the heating temperature of the press laminate, but the printing ink was discolored due to color burn, or the pattern was stretched and distorted by heat with the sheet It became. Furthermore, the recrystallization of stretched PET has progressed, causing a problem that the card substrate is brittle and easily cracked.
[0009]
Therefore, the inventor of the present application, in a non-contact IC card manufactured by embedding an antenna sheet, absorbs the protrusions of the IC chip and the antenna to ensure the smoothness of the card and the delamination strength between the printed sheet and the spacer sheet. The present invention has been completed by researching to solve the problem of increasing the frequency by another method.
[0010]
[Means for Solving the Problems]
Abstract of the invention to solve the above problems is to center the antenna sheet equipped with IC chips, sandwiched between front and back surfaces of the printed sheets through the both sides of the spacer sheet, the base integral with hot pressing in the non-contact IC card in the spacer sheet, the three layers of polyester adhesive was coextruded to a thickness on both surfaces of the PET-G resin substrate contains a thermally curing agent is 30~50μm configuration And a through hole that absorbs the thickness of the IC chip is formed in the front and back spacer sheets .
[0012]
DETAILED DESCRIPTION OF THE INVENTION
There are various types of non-contact IC cards, but in order to make the card thickness stipulated by JIS and ISO and to make the card surface smooth, the antenna sheet with the IC chip mounted is sandwiched between the card substrates on the front and back sides. It is common to have a form.
Even if an antenna is formed by etching a metal thin film without using a winding, a projection of 20 μm to 30 μm is formed from the sheet surface.
Since the IC chips attached to both ends of the antenna further have a thickness (projection) of about 150 μm to 300 μm, the antenna sheet has inevitable projections or irregularities, and is press-laminated between ordinary front and back substrates as it is. Therefore, an IC card with sufficiently excellent smoothness cannot be obtained.
[0013]
The present invention has the following layer structure in order to solve the problem of the delamination strength together with the problem of smoothness.
As the spacer sheet, a sheet having a two-layer or three-layer structure in which a polyester adhesive is coextruded on one side or both sides of a PET-G resin sheet is used.
In this case, the melt viscosity of the adhesive was 190 ° C. and 2500 poise or less, and the thicknesses of the adhesive layers on the front and back sides were about 30 to 50 μm, respectively.
[0014]
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an exploded sectional view showing the layer structure of the card of the present invention, FIG. 2 is a plan view of an antenna sheet used in the present invention, and FIG. 3 is a press-laminated layer structure of FIG. FIG. 4 is a cross-sectional view taken through the IC chip portion of the card of FIG. 3.
In each figure, it should be noted that the thickness direction of the card is enlarged as compared with the width direction. For example, since the IC chip 4 is only about 150 μm to 300 μm in height, it actually has a flat appearance.
[0015]
As shown in FIG. 2, the antenna sheet 11 has a planar coil antenna 3 on a PET sheet, and the IC chip 4 is attached to both ends 31 t and 32 t of the coil antenna 3.
Although the coil antenna 3 is illustrated in a simplified manner, the coil antenna 3 is formed so as to go around the card base (a hatched portion) several times. The coil antenna 3 is obtained by forming a resist on an aluminum foil or copper foil (thickness 20 to 30 μm) laminated on a sheet, and leaving only the coil shape by a well-known photo-etching technique.
Although not limited to an IC chip, an IC module sealed with resin may be used, but hereinafter, it will be collectively expressed as an IC chip.
[0016]
When stacking card bases, as shown in FIG. 1, the antenna sheet 11 is arranged at the center, and spacer sheets 15 and 16 are inserted between the antenna sheet 11 and the front and back printed sheets 20 and 30, respectively. . The spacer sheet 15 has a configuration in which spacer / adhesive layers 15a and 15b are laminated on a spacer / core layer 15c made of PET-G resin. The spacer sheet 16 also has the same configuration.
The PET-G resin is generally a dehydration condensate of an aromatic dicarboxylic acid and a diol, and is composed of a substantially non-crystalline aromatic polyester resin having a particularly low crystallinity among the copolyesters. However, in the present invention, a special blend is used.
[0017]
For the spacer / adhesive layers 15a, 15b, 16a, 16b themselves, a polyester-based adhesive is used in consideration of heat fusion between the layers.
The spacer / adhesive layers 15 a and 16 a are intended to adhere to the print sheet 20 or the print sheet 30, and the spacer / adhesive layers 15 b and 16 b are intended to adhere to the antenna sheet 11. As a result, a stronger bond can be obtained with respect to the PET sheets of the print sheets 20 and 30 and the antenna sheet 11 that do not have heat-fusibility than the PET-G sheet alone.
However, when the printing sheet is a PET-G base material having heat-fusibility, the spacer / adhesive layers 15a and 16a may be omitted.
[0018]
In the case of the card layer configuration of the present invention, the adhesive layer needs to have a melt viscosity of 190 ° C. and a low viscosity of 2500 poise or less and up to about 1500 poise. This is because a flow is generated by heat at the time of press lamination, and the effect of completely absorbing the unevenness of the antenna sheet is exhibited.
Further, the spacer / adhesive preferably contains a curing agent that causes a curing reaction by heat or moisture adsorption. This is because when the curing agent is contained in the adhesive, it does not soften even when reheated, and therefore, delamination does not occur even when the card is used in a high temperature environment.
[0019]
Through holes 151 and 161 are formed in portions of the spacer sheets 15 and 16 where the IC chip 4 abuts or is positioned so as to absorb the thickness of the IC chip.
The total thickness of the two spacer sheets 15 and 16 is equal to the thickness of the IC chip 4 of the antenna sheet 11, and a through hole having substantially the same size as the IC chip 4 is provided.
[0020]
As the front and back printed sheets 20 and 30, a white PET sheet biaxially stretched as described above or a white PET-G sheet that is not stretched is used. Generally, a decorative front surface printing layer 21 is often printed on the front side printing sheet 20 before pressing, and a back side printing layer 31 such as letters is printed on the back side printing sheet 30 after pressing. However, it is not limited to this. Moreover, in order to protect the printed layer of the front and back, a protective layer with a transparent protective film or transparent ink may be provided.
[0021]
In the case of transportation use or the like, a rewrite sheet 12 capable of thermal recording is attached to a part or the entire surface of the surface printing sheet 20. The rewritable sheet is transparent and does not hinder the visibility of the front printed layer 21.
The rewritable sheet 12 is formed by forming a rewritable recording layer of leuco dye on a biaxially stretched PET resin film and a protective layer thereof, and further having an adhesive layer on the card surface side of the PET resin film.
When the rewritable sheet is provided on one side, the card is likely to be warped. Therefore, it is necessary to take measures to use a biaxially stretched PET sheet as the print sheet and to completely align the stretch direction. That is, the front and back printed sheets 20 and 30 are all aligned in the longitudinal and lateral directions, and the front and back printed sheets are arranged symmetrically with respect to the center layer of the card. Preferably, the sheet is taken from the original sheet. To match.
Details of these techniques are described in Japanese Patent Application No. 2002-337238 by the present applicant.
[0022]
The rewritable sheet becomes a rewritable recording layer after completion, and it is possible to use the thermal head to clearly print the boarding section and the valid period, and to erase and use it after use. In addition, although not shown, it is also possible to provide an image receiving layer for sublimation transfer recording and to emboss characters.
Instead of the rewrite sheet 12, a rewrite layer may be provided by printing. In the case of not using the rewritable sheet 12 or in the case of a rewritable layer by printing, there is little warping of the card, so an unstretched PET-G sheet can be used for the front and back printed sheets. In this case, the stretching direction is changed as described above. You don't need to do anything to align. Further, it may be a two-layer spacer sheet in which an adhesive is coextruded only on one side (the side in contact with the antenna sheet).
[0023]
After the press lamination of the layer configuration of FIG. 1, the contactless IC card 1 as shown in FIGS. 3 and 4 is obtained. FIG. 3 is a plan view of the surface side, and the rewrite prints 2a, 2b, and 2c printed on the rewrite recording layer can be visually recognized together with the printed patterns 5a and 5b.
4 is a cross-sectional view through the IC chip portion of the card of FIG. The antenna sheet 11 is firmly bonded to the print sheet 20 by the spacer sheet 15 with the spacer / adhesive layer and to the print sheet 30 by the spacer sheet 16 with the spacer / adhesive layer.
In addition, since the IC chip 4 is positioned substantially at the center of the card base by providing the through holes 151 and 161, the appearance is not significantly impaired by the influence of the IC chip. In FIG. 4, the antenna sheet 11 is bent only in the IC chip 4 portion, and the coil antenna 3 itself is in the flat portion, so that the communication characteristics are not affected.
[0024]
【Example】
An embodiment of the present invention will be described with reference to FIGS. A non-contact IC card with a rewrite recording layer was manufactured for use in ticket gates for transportation.
(Example)
<Preparation of antenna sheet>
A coil antenna 3 was formed by bonding an aluminum foil having a thickness of 20 μm to an PET film having a thickness of 40 μm via an adhesive and etching the aluminum foil using a photoresist. Further, an IC chip 4 having a thickness of 300 μm was mounted by being electrically connected to both ends 31t and 32t of the coil antenna 3 to complete an antenna sheet (inlay) 11 included in the card.
The IC chip 4 has a total thickness of 300 μm after adding a reinforcing plate of 100 μm and an anisotropic conductive sheet of 50 μm to an IC chip having a thickness of 175 μm and receiving pressure from a press lamination.
[0025]
<Manufacture of card base>
The layer structure of the card substrate is such that printed sheets 20 and 30 on the front and back sides are arranged on the front and back sides of the antenna sheet 11 via spacer sheets 15 and 16.
The spacer sheets 15 and 16 are three-layered sheets in which a polyester adhesive is coextruded on both sides of a PET-G resin sheet. Each of the spacer core layers 15c and 16c has a thickness of 120 μm, and polyester adhesive on both sides. The total thickness of the spacer / adhesive layers 15a, 15b, 16a, and 16b is 30 μm. The total thickness is 180 μm.
The spacer core layers 15c and 16c were made of PET-G resin by blending polycarbonate resin to Tg (glass transition temperature) = 100 ° C.
For the spacer / adhesive layers 15a, 15b, 16a and 16b, a polyester-based adhesive (melt viscosity 2000 poise; 190 ° C.) containing a thermosetting agent was employed.
[0026]
On the outer side of the spacer sheets 15 and 16, biaxially stretched PET sheets with a thickness of 188 μm are adopted as the print sheets 20 and 30 and arranged so that the stretch directions are completely coincided and the front and back are symmetrical. did.
On the print sheet 20 on the front side of the card, a picture matched to the layout of the inlay was printed in advance. Printing was carried out by silk screen printing and offset printing.
A rewrite sheet 12 with an adhesive having a thickness of 50 μm is provided only on the outermost surface side of the card so that the date using the card can be displayed in the ticket gate application.
As a result, a layer structure of six layers was obtained. The total thickness of the material used excluding the thickness of the coil antenna 3 and the IC chip is 826 μm.
[0027]
In the spacer sheets 15 and 16, through holes 151 and 161 having the same size as the IC chip 4 (about 5 mm × 5 mm) were punched in advance so that the IC chip mounted on the antenna sheet penetrates.
The antenna sheet 11, the spacer / adhesive layer, and the spacer sheet were aligned by fitting the antenna sheet, each spacer / adhesive layer, and a hole provided in the spacer sheet to a pin.
The six-layer laminate was placed on a hot plate of a press machine and press laminated. The conditions of the pressing process were as follows: hot plate temperature 120 ° C, pressure 2.0 MPa, molding (heating) time 20 min. I went to set.
[0028]
The sheet integrated by the press was punched into a card shape according to the pattern, and finally pattern printing (back surface printing layer 31) was performed on the back side. In the same manner as the front side, printing was performed by printing offset printing on silk screen printing.
In this way, a non-contact IC card 1 having a total thickness of 0.82 mm and having a rewrite recording layer was completed. The finished card was highly durable, and even when used and stored in a high temperature environment, the substrate did not peel off. In addition, it was inexpensive, free from discoloration and distortion of the pattern, excellent appearance quality, and excellent rewrite printability.
[0029]
A comparative example of the present invention will be described with reference to FIG.
(Comparative example)
<Preparation of antenna sheet>
The antenna sheet was prepared using the same material as in the example and having the same thickness.
[0030]
<Manufacture of card base>
The layer structure of the card substrate is as shown in FIG. That is, 50 μm thick adhesive sheets 13, 14 on the front and back of the antenna sheet 11, 180-μm thick PET-G spacer sheet 15 on the outer card surface side, and 180 μm-thick PET-G made on the back side of the card. A spacer sheet 16 and a biaxially stretched PET sheet having a thickness of 125 μm were disposed outside the spacer sheets 16 as printing sheets 20 and 30, and a rewrite sheet 12 having a thickness of 50 μm was provided only on the outermost surface side of the card. On the print sheet 20 on the card surface side, a picture matched to the layout of the inlay was printed in advance. Printing was carried out by silk screen printing and offset printing.
A polyester hot melt adhesive (melt viscosity 2000 poise: 190 ° C.) was used for the adhesive sheets 13 and 14 in consideration of the adhesion suitability between the PET film of the antenna sheet and the spacer sheets 15 and 16.
Thereby, it became a layer structure of 8 layers for convenience. The total thickness of the materials used excluding the thickness of the coil antenna and the IC chip is 800 μm.
[0031]
The spacer sheet 16 on the side of the antenna sheet 11 from which the IC chip 4 protrudes and the spacer sheet 15 on the back side have the same size as the IC chip 4 (about 5 mm in advance) so that the IC chip mounted on the antenna sheet penetrates. × 5 mm) through-holes 151 and 161 were provided by punching.
However, the adhesive sheets 13 and 14 were not provided with through holes.
[0032]
The alignment of each layer was performed in the same manner as in the example, and the laminate composed of 8 layers was placed on a hot plate of a press machine and press laminated. The conditions for the pressing step were the same as in the example, hot plate temperature 120 ° C, pressure 2.0 MPa, molding (heating) time 20 min. I went to set.
[0033]
The sheet integrated by the press was punched into a card shape according to the pattern, and finally pattern printing (back surface printing layer 31) was performed on the back side. In the same manner as the front side, printing was performed by printing offset printing on silk screen printing.
In this way, a non-contact IC card having a total thickness of 800 μm was completed.
[0034]
The delamination strength between the printed sheet and the spacer sheet of the non-contact IC card obtained in Examples and Comparative Examples was measured immediately after press lamination and after aging.
The measurement results are shown in Table 1. For the test apparatus, TG-500N manufactured by NMB was used, and the peeling speed was 100 mm / min. The test was conducted under the following conditions.
The test was conducted using a sample having a width of 15 mm, and the measured value was converted to a width of 10 mm.
[0035]
Results of T-type peel test between printed sheet and spacer sheet [Table 1]

[0036]
As shown in Table 1, there is already a large difference of 3 times or more between both values even immediately after press lamination. Furthermore, it can be seen that prior art cards are significantly reduced in strength when stored at high temperatures. In fact, at 6 N / cm or less, it becomes weak enough to be peeled off with a fingertip. On the other hand, it was confirmed that the card of the present invention maintains a sufficient peel strength even after being stored at 90 ° C. for 24 hours.
[0037]
【The invention's effect】
As described above, in the non-contact IC card of the present invention, since the spacer sheet and the printed sheet are firmly bonded, they have excellent durability against bending and torsional loads received during actual use. Further, since the adhesive layers on the front and back sides of the spacer sheet are provided by coextrusion, the number of sheets to be superimposed can be reduced, and the material cost and the manufacturing cost can be reduced. In addition, the thickness of the adhesive layer sufficient to absorb the unevenness of the antenna sheet can be obtained.
Since there is no need to increase the heating temperature during press lamination, there is no color burn or discoloration of the printing ink, no distortion of the pattern, and there is no concern that the card substrate is brittle and easily cracked.
In the case where a curing agent is contained in the adhesive layer, it does not soften even when reheated, so that there is no problem of delamination even when used in a high temperature environment.
[Brief description of the drawings]
FIG. 1 is an exploded sectional view showing a layer structure of a card according to the present invention.
FIG. 2 is a plan view of an antenna sheet used in the present invention.
3 is a top plan view showing a state of a card after press laminating the layer configuration of FIG. 1; FIG.
4 is a cross-sectional view of the card of FIG.
FIG. 5 is a diagram showing a layer structure of a conventional non-contact IC card.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Non-contact IC card, rewrite card 3 Coil antenna 4 IC chip 10 Card base material 11 Antenna sheet 12 Rewrite sheet 13, 14 Adhesive sheet 15, 16 Spacer sheet 20, 30 Print sheet 21 Front surface print layer 31 Back surface print layer

Claims (4)

Arranged around the antenna sheet equipped with IC chips, sandwiched between front and back surfaces of the printed sheets through the both sides of the spacer sheet, in the contactless IC card to the substrate of the integrated and hot pressing, the spacer sheet to, use a sheet of polyester adhesive co-extruded three-layer structure thickness on both surfaces of the PET-G resin substrate containing a thermosetting agent be 30 to 50 [mu] m, more sides of the spacer sheet A non-contact IC card, wherein a through-hole that absorbs the thickness of an IC chip is formed . 2. The non-contact IC card according to claim 1, further comprising a rewrite recording layer on an outermost surface. Contactless IC card according to claim 1, wherein the der Rukoto those thermosetting agent is curing reaction by adsorption heat or moisture. The melt viscosity of the polyester adhesive before curing, the non-contact IC card according to claim 1, wherein a is less than or equal 2500Poise (190 ° C).

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