JP2009262557A - Core sheet for card, and card substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an IC card substrate drastically improved in disadvantages related to material strength such as cracks and further fusion after screen printing. <P>SOLUTION: In a core sheet for a card made of a thermoplastic resin composition, the thermoplastic resin composition contains a resin component (A) containing a copolymer polyester resin (a1) made by substituting cyclohexanedimethanol for 10 mol.% to 70 mol.% of an ethyleneglycol component of a polyethylene terephthalate resin, and a polycarbonate resin (a2) having a predetermined melt flow. The weight ratio ((a1)/(a2)) of the copolymer polyester resin (a1) in the resin component (A) to the polycarbonate resin (a2) is (a1)/(a2)=60/40 to 30/70. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a card substrate for an IC card produced by combining a core sheet for a screen printing card and an oversheet used by being laminated on the core sheet.

  In recent years, in various types of cards such as a credit card, a cash card, and a prepaid card, an IC card equipped with an IC module having a large recording capacity and excellent security is widely used in place of a conventional magnetic card. There are two types of IC cards, contact type and non-contact type, depending on the recording medium reading method. Conventionally, in the contact type method, when the IC card and the reader come into contact with each other when communicating with the terminal, the contact is dirty or easily broken, and the maintenance of the reader also requires man-hours. In the non-contact type, the recording medium and the reader do not have a contact point, so there is a problem in security systemization. However, many of these problems have already been solved by various system improvements, and IC cards are widely deployed in the field of transportation such as financial cash cards, credit cards, and commuter passes. Practical use is progressing rapidly.

These IC card manufacturing methods include a method of cutting an IC module embedding hole in a core sheet, or a space between the core sheet and the oversheet to secure an embedding space. The method of embedding IC modules by laminating and hot pressing has become the mainstream. However, when cutting is performed, the thickness of the core sheet is structurally reduced in the embedded portion of the IC module. Even when the spacer is used, the thickness of the IC module embedded portion is relatively thinner than the other portions. In such a state, for example, when a financial IC card such as a cash card is repeatedly inserted into an automatic cash payment machine (hereinafter referred to as ATM), cracks in the vicinity of the IC module caused by the force applied to the IC card, The crack of the IC card body is a big problem.

By the way, plastic cards are generally produced by laminating transparent sheets called oversheets on both sides of a white colored sheet called a core sheet. The lamination of the core sheet and the oversheet is often performed by bonding heat-sealable resins together or using an adhesive.

In general, a sheet made of a polyvinyl chloride resin has been used for these card sheets, but due to the problem of incineration, cases in which a polyester resin is used are increasing. Among them, a copolymerized polyester resin (hereinafter referred to as PETG resin) obtained by substituting the ethylene glycol component of the polyethylene terephthalate resin with cyclohexanedimethanol is particularly often used.

However, non-crystalline polyester resins such as PETG resin are slow to dry the ink and solvent, so if the sheets are stacked immediately after printing, the ink and solvent of the lower sheet are placed on the back side of the upper sheet stacked on the printed surface of the sheet. May be transferred and a defective fusion may occur between the two sheets when creating a card.

In order to prevent such poor fusion, measures such as increasing the drying time and changing the solvent composition of the ink have been studied. However, from the viewpoint of production efficiency, it is necessary to carry out production under the same conditions as those of conventional PVC cards, and development of polyester sheets that can shorten the drying time is required.

  Further, as one of the card applications that have been spreading in recent years, there is a non-stop automatic toll collection system (ETC) application on a highway. There are cases where the ETC card is left in the car interior or used while being inserted into the vehicle-mounted device in the car. Therefore, even in the summer when the room temperature rises to 80 ° C. to nearly 90 ° C., it is required that the card does not warp when left in the vehicle and that no dent occurs when it is inserted into the vehicle-mounted device in the vehicle. That is, the card sheet is required to have heat resistance that does not cause the above problems.

If the card is not heat resistant, warping and dents are generated, which is not preferable in appearance. In the case of a contact type IC card or magnetic stripe card (hereinafter referred to as a magnetic card), the card is inserted into and removed from the reader / writer. Resistance occurs. Since the PETG resin itself has low heat resistance, it has been pointed out that the heat resistance required for the ETC card application as described above cannot be sufficiently satisfied.

Many techniques for imparting heat resistance to a PETG resin card sheet have been reported. For example, Patent Documents 1 and 2 report that heat resistance can be imparted by blending or laminating a heat-resistant resin such as polycarbonate resin (PC resin) to PETG resin. However, the technique described in this document has not yet solved the problem of poor fusing between two sheets when screen printing is performed under the same conditions as a card made of polyvinyl chloride resin.

Conventionally, as an oversheet for an IC card, a mixture of a non-crystalline aromatic polyester resin composition and a polycarbonate resin set is used as a single layer sheet, or a non-crystalline aromatic polyester resin composition A multilayer film composed of a skin layer composed of the above and a core layer composed of a polycarbonate resin composition and laminated in at least three layers of skin layer / core layer / skin layer by a coextrusion method has been used. (For example, Patent Document 3)

It is assumed that conventional IC card oversheets are designed to provide resistance to cracking and impact by using polycarbonate resin, but as described above, IC cards with embedded IC modules are subject to repeated external forces, etc. Many problems such as cracks and the IC card itself are broken, resulting in a serious quality problem.

Recently, a card substrate having a module hole or embedded recess for mounting an IC module having an IC chip and an oversheet bonded to the card core sheet so as to close the IC module hole or embedded recess. And at least the IC chip of the IC module is an elastic body having a 2% elastic modulus of 0.05 to 50 kgf / mm ² and sealed in the IC module hole or the embedded recess. IC card manufacturing methods have also been proposed. (For example, Patent Document 4)

  As described above, although attempts to improve the impact resistance by devising the IC module embedding method are sporadic, among the materials that have been used for IC cards so far, it has caused poor fusion after screen printing. However, the development of materials for a core sheet and an oversheet that have sufficient strength against cracks and cracks generated around the IC module portion due to external stress has not been made yet.

Japanese Patent Application No. 2000-89403

Japanese Patent Laid-Open No. 2005-84931

JP 2001-80251

Patent No. 3045112

An object of the present invention is to provide a core sheet for card for screen printing and an IC card using the same, which are excellent in heat resistance, warpage, impact resistance, flex resistance and printability.

Such an object is achieved by the present invention described below.

[1] A card core sheet made of a thermoplastic resin composition, wherein the thermoplastic resin composition is a copolymerized polyester resin obtained by substituting 10 to 70 mol% of an ethylene glycol component of a polyethylene terephthalate resin with cyclohexanedimethanol. A resin component comprising (a1) and a polycarbonate resin (a2) having a melt flow rate (measurement condition ASTM D-1238 compliant, resin melting temperature 300 ° C., weight 1.2 kg) of 3.0 to 13.0 g / 10 min. (A), and the weight ratio ((a1) / (a2)) of the copolymerized polyester resin (a1) and the polycarbonate resin (a2) in the resin component (A) is (a1) / (a2) = Core sheet for card which is 60 / 40-30 / 70.

[2] The thermoplastic resin composition further comprises 5 to 25 parts by weight of an inorganic filler (B), 5 to 20 parts by weight of a rubber-like elastic body (C), and 100 parts by weight of the resin component (A). The core sheet for cards according to [1] above, comprising 10 to 20 parts by weight of titanium oxide (D).

[3] A card substrate produced by assembling a card core sheet and an oversheet, wherein the card core sheet is the card core sheet of [1] or [2].

[4] The oversheet includes a fusion layer mainly composed of a copolyester obtained by substituting 10 to 70 mol% of the ethylene glycol component of the polyethylene terephthalate resin with cyclohexanedimethanol, a polycarbonate resin (PC) and a poly The card substrate according to the above [3], which is an oversheet comprising a protective layer containing a resin component having a weight ratio to the butylene terephthalate resin (PBT) of PC / PBT = 70/30 to 25/75.

  The core sheet for a card according to the present invention is a polyester-based sheet, and can improve the fusion property when pressing two sheets without requiring a long drying process after printing. Even if screen printing is performed under the production conditions when using a conventional PVC sheet in a printing facility or the like, it is possible to reduce the occurrence of poor fusion and improve productivity.

  Hereinafter, the card core sheet and the substrate according to the present invention will be described in detail. The card core sheet of the present invention comprises a thermoplastic resin composition, and the thermoplastic resin composition was measured at a resin melting temperature of 300 ° C. and a load of 1.2 kg in accordance with PETG resin (a1) and ASTM D-1238. A resin component (A) containing a polycarbonate resin (a2) having a melt flow rate of 3.0 to 13.0 g / 10 min, and the copolymer polyester resin (a1) and the polycarbonate resin in the resin component (A) The weight ratio ((a1) / (a2)) to (a2) is (a1) / (a2) = 60/40 to 30/70.

 The PETG resin which is the component (a) used in the present invention is a copolymerized polyester resin obtained by substituting 10 to 70 mol% of an ethylene glycol component of a polyethylene terephthalate resin with cyclohexanedimethanol, and the amount of substitution of the ethylene glycol component Is more preferably 20 to 35 mol%.

  If the substitution amount of the ethylene glycol component is less than 10 mol%, the resin does not become sufficiently amorphous, and thus the elastic modulus of the sheet when it is made into a sheet, weakening of the sheet occurs, and the moldability is lowered. Also, in applications that require heat fusion, recrystallization of the sheet proceeds at the time of cooling after fusing, and heat fusion properties are lost, so there is a problem that sufficient adhesive strength cannot be obtained. Arise. On the other hand, when the substitution amount of the ethylene glycol component exceeds 70 mol%, the resin is not sufficiently amorphous, and the same problem as when the substitution amount of the ethylene glycol component is less than 10 mol% occurs. It is not preferable.

  The polycarbonate resin which is the component (b) used in the present invention is obtained by a phosgene method in which various dihydroxydiaryl compounds and phosgene are reacted, or a transesterification method in which a dihydroxydiaryl compound and a carbonate such as diphenyl carbonate are reacted. It is a polymer.

  Examples of the dihydroxydiaryl compound include bisphenol 4-, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) butane, 2, 2-bis (4-hydroxyphenyl) octane, bis (4-hydroxyphenyl) phenylmethane, 2,2-bis (4-hydroxyphenyl-3-methylphenyl) propane, 1,1-bis (4-hydroxy-3) Bis (hydroxyaryl) alkanes such as tert-butylphenyl) propane, bis (hydroxy) such as 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (4-hydroxyphenyl) cyclohexane Aryl) cycloalkanes, 4,4′-dihydroxydiphenyl ether, Dihydroxy diaryl ethers such as 4,4'-dihydroxy-3,3'-dimethyldiphenyl ether, dihydroxy diaryls such as 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfide Sulfides, 4,4′-dihydroxydiphenyl sulfoxide, dihydroxydiaryl sulfoxides such as 4,4′-dihydroxy-3,3′-dimethyldiphenyl sulfoxide, 4,4′-dihydroxydiphenyl sulfone, 4,4′-dihydroxy Examples include dihydroxydiaryl sulfones such as −3,3′-dimethyldiphenyl sulfone, and these may be used alone or in combination.

  The polycarbonate resin melt flow rate used in the present invention is a resin melt temperature of 300 ° C. and a load of 1.2 kg in accordance with ASTM D-1238 from the viewpoint of moldability, strength, heat resistance, and printability. When measured by (3), it is 3.0 to 13.0 g / 10 min, and preferably 4.0 to 8.0 g / 10 min. When the melt flow rate of the polycarbonate resin is less than 3.0 g / 10 min, it cannot be extruded. On the other hand, if it exceeds 13.0 g / 10 min, after screen printing, ink and solvent enter the PC molecular chain, and it is difficult for the solvent to escape under drying conditions of 40 ° C. and 10 min. For this reason, when the two sheets are pressed, poor fusion occurs. Moreover, when manufacturing this polycarbonate resin, you may add a molecular weight regulator, a catalyst, etc. as needed.

  Furthermore, when the blending amount of the polycarbonate resin in the core sheet is less than 40 parts by weight, defects related to material strength such as cracking occur due to various external stresses that are received when the IC card is carried. On the other hand, when the amount exceeds 70 parts by weight, when the embossed characters are imprinted under the same conditions as the card made of polyvinyl chloride resin, the warp of the card increases.

  The core sheet used in the present invention may contain an inorganic filler and a rubber-like elastic body, and examples of the inorganic filler include talc, mica, calcium carbonate and the like. Among these, talc having an average particle size of 0.5 to 50 μm is preferable.

  Rubber-like elastic materials include acrylic polymers and methacrylic polymers mainly composed of alkyl acrylate and alkyl methacrylate, diene polymers mainly composed of conjugated dienes such as butadiene and isoprene, and silicones composed mainly of polyorganosiloxane. There are one or more types of copolymers, methyl methacrylate / butyl acrylate / styrene resin, methyl methacrylate / butadiene / styrene resin (hereinafter abbreviated as MBS resin), butyl acrylate / isoprene / styrene resin, etc. Can be used. In particular, MBS resin is preferable. Examples of rubber-like elastic bodies other than the above include butadiene rubber, styrene-butadiene rubber, acrylonitrile-butadiene-styrene, isobutylene-isoprene rubber, ethylene-propylene rubber, ethylene-propylene-diene rubber, acrylonitrile-butadiene rubber, styrene-butadiene- Examples include styrene rubber, hydride of styrene-butadiene rubber, hydride of styrene-isoprene-styrene rubber, styrene-isoprene rubber, and the like. These rubber-like elastic bodies may be used alone or in combination of two or more.

  The card substrate according to the present invention is produced by combining the card core sheet and the oversheet.

The oversheet used for the card substrate according to the present invention includes a fusion layer containing PETG resin, 70 to 25% by weight of polycarbonate resin, and 30 to 75% by weight of polybutylene terephthalate.
It is preferable to consist of a protective layer having a resin component containing.

  When the blending amount of the polycarbonate resin in the oversheet protective layer is less than 25 parts by weight, problems relating to material strength such as cracking occur. Moreover, when it exceeds 70 weight part, the curvature of a card | curd will become large.

  In the card substrate of the present invention, additives usually used as desired, for example, compatibilizers, stabilizers, lubricants, reinforcing agents, processing aids, pigments, antistatic agents, antioxidants, neutralizing agents. , UV absorbers, dispersants, thickeners, other inorganic fillers, or other synthetic resins may be included.

(Film forming method)
In order to process the card core sheet of the present invention into a sheet, there are a calendering method, an extrusion method, a pressing method, a casting method and the like, but there is no particular limitation here. Moreover, the manufacturing method of the multilayer film of this invention is not specifically limited, Any conventionally well-known manufacturing methods of a multilayer film, such as a co-extrusion method, an extrusion lamination method, and a dry lamination method, can be used. The multilayer film of the present invention thus obtained forms a card with a press configuration of a patch plate / oversheet / core sheet / oversheet / plate. The pressing condition is not particularly limited, but the pressing temperature is 80 to 150 ° C, preferably 100 to 130 ° C.

(IC card manufacturing method)
The multilayer film of the present invention is suitable as an oversheet used on the front and back sides of a card substrate, particularly a core sheet. The oversheet may be further provided with a concealing layer, a protective layer and the like as necessary. In order to produce an IC card using the multilayer film of the present invention, the same production method as in the case of a known multilayer film may be used. In the conventional IC card, the IC module is made of a material different from that of the card substrate. As a method of embedding such an IC module in a card substrate, for example, a card having an oversheet laminated on a core sheet is provided with a concave part of the size of the IC module by an end mill, a drill or the like, and the IC module is bonded to the concave part. There is a method of embedding an IC module through an agent.

Hereinafter, the present invention will be described by way of examples, but this is merely an example, and the present invention is not limited thereto. The raw materials used in the examples are as follows, and the raw materials shown in Table 1 are as follows.
(1) PETG resin: poly (ethylene-1,4-cyclohexylenedimethylene terephthalate) resin, GN071, manufactured by Eastman Chemical Japan Co., Ltd. (2) PC resin 1: polycarbonate resin, 200-3 (MFR: 3 0.0 g / 10 min), manufactured by Sumitomo Dow Co., Ltd. (3) PC resin 2: polycarbonate resin, E2000N (MFR: 5.0 g / 10 min), manufactured by Mitsubishi Engineering Plastics Co., Ltd.
(4) PC resin 3: polycarbonate resin, S-1000 (MFR: 7.5 g / 10 min), manufactured by Mitsubishi Engineering Plastics (5) PC resin 4: polycarbonate resin, 200-13 (MFR: 13 g / 10 min), Sumitomo Dow (6) PC resin 5: Polycarbonate resin, 200-22 (MFR: 22 g / 10 min), Sumitomo Dow (7) PC resin 6: Polycarbonate resin, H3000 (MFR: 28 g / 10 min) ), Manufactured by Mitsubishi Engineering Plastics Co., Ltd. (8) PBT resin: polybutylene terephthalate resin, 5020, manufactured by Mitsubishi Engineering Plastics Co., Ltd.

[Examples and Comparative Examples]
(Production of core sheet)
The composition content of Table 1 was extruded into a sheet shape to prepare a core sheet. The thickness of the sheet was 310 μm. The prepared core sheet and oversheet were sandwiched between press plates in the form of oversheet / core sheet / core sheet / oversheet, and pressed at 140 ° C. for 10 minutes. The obtained multilayer sheet is punched into a card size specified by ISO / IEC7810 to produce a card-like sample, and a concave portion of an IC module size is provided, and the IC module is embedded in the concave portion via an adhesive. Fusing, heat resistance, impact resistance, bending resistance after screen printing, cracks during ATM transport, and card warpage when embossed letters were imprinted were evaluated. The results are shown in Table 2. Various evaluations were performed based on the following. The results are shown in Table 1.

(Fusibility after screen printing)
After printing on the produced sheet and stacking for 30 days, the unprinted surfaces were fused together, and the peel strength was measured.
○: Material breakage ×: Peeling material punchability

(Heat-resistant)
The produced card-like sample was inserted into the vehicle-mounted device, and the vehicle-mounted device was placed in an oven at 90 ° C. to check whether the card was recessed (vehicle-mounted device: EP221 manufactured by Mitsubishi Electric).
Each code | symbol is as follows. X was rejected, and the others were determined to be acceptable.
○: The indentation is inconspicuous ×: The indentation is conspicuous

(Flexibility)
The produced card-like sample was bent 250 times in the short side direction, long side direction, short side back direction, and long side back direction of the card-like sample by a bending tester, and it was confirmed whether or not the sample was broken. X was rejected, and the others were determined to be acceptable.
○: No cracking 3000 times or more Δ: Cracking 2000 times to 3000 times ×: Cracking less than 2000 times

(Crack during ATM transport: durability against cracking)
The created card-like sample was put in and out of the ATM conveyance tester 100 times, and it was confirmed whether or not it cracked. X was rejected, and the others were determined to be acceptable.
○: No cracking 3000 times or more Δ: Cracking 2000 times to 3000 times ×: Cracking less than 2000 times

(warp)
After the embossed characters were imprinted on the card-like sample thus produced using Japanese Data Card Embosser DC9000, the warpage of the card-like sample was measured according to JIS X6301. X was rejected, and the others were determined to be acceptable.
○: Warpage after embossed character marking was less than 2.5 mm △: Warpage after embossed character marking was 2.5 mm or more or less than 3.0 mm ×: Warpage after embossed character marking was 3.0 mm or more Things

  The IC card substrate formed from the core sheet and the multilayer film of the present invention has heat resistance and high bending resistance, and is naturally used for fusion after printing, low warpage, repeated transport in ATM and daily life. With respect to the external stress that can be received, it can be used for a long period of time, which has heretofore been difficult to achieve.

Claims (4)

A core sheet for a card comprising a thermoplastic resin composition,
A copolymer polyester resin (a1) in which the thermoplastic resin composition is obtained by substituting 10 to 70 mol% of an ethylene glycol component of a polyethylene terephthalate resin with cyclohexanedimethanol;
A resin component (A) containing a polycarbonate resin (a2) having a melt flow rate (measuring condition ASTM D-1238 compliant, resin melting temperature 300 ° C., weight 1.2 kg) of 3.0 to 13.0 g / 10 min. ,
The weight ratio ((a1) / (a2)) between the copolymerized polyester resin (a1) and the polycarbonate resin (a2) in the resin component (A) is (a1) / (a2) = 60 / 40-30. / 70 core sheet for cards.   The thermoplastic resin composition further comprises 5 to 25 parts by weight of an inorganic filler (B), 5 to 20 parts by weight of a rubber-like elastic body (C), and titanium oxide (100 parts by weight of the resin component (A). D) The core sheet for cards according to claim 1, comprising 10 to 20 parts by weight. The card base material which is a card produced by combining a card core sheet and an oversheet, and the said core sheet for cards is the core sheet for cards of Claim 1 or 2. A fusing layer mainly composed of a copolyester obtained by replacing 10 to 70 mol% of the ethylene glycol component of the polyethylene terephthalate resin with cyclohexanedimethanol;
4. The card according to claim 3, which is an oversheet comprising a protective layer containing a resin component in which the weight ratio of the polycarbonate resin (PC) and the polybutylene terephthalate resin (PBT) is PC / PBT = 70/30 to 25/75. Base material.