Highly flexible foil composite material and its use in card bodies

Abstract

A foil composite material usable as a layer in a card body of a portable data carrier, that includes one outer plastic layer, one inner plastic layer and one second outer plastic layer. All the layers jointly form a coextruded composite, and the plastic of one outer layer is a thermoplastic polymer or a mixture thereof. The plastic of the one inner layer is a mixture of at least one thermoplastic elastomer and at least one thermoplastic polymer. The plastic of the second outer layer is a thermoplastic polymer or a mixture thereof.

Claims

1. A foil composite material comprising: at least one first outer plastic layer, at least one inner plastic layer, at least one second outer plastic layer, wherein all the layers jointly form a coextruded composite, the plastic of the at least one first outer layer being a thermoplastic polymer or a mixture of thermoplastic polymers, the plastic of the at least one inner layer being a mixture of at least one thermoplastic elastomer and at least one thermoplastic polymer, the plastic of the at least one second outer layer being a thermoplastic polymer or a mixture of thermoplastic polymers, wherein the foil composite material is transparent and has a first outer plastic layer, a first exterior inner plastic layer, an interior inner plastic layer, a second exterior inner plastic layer and a second outer plastic layer, the plastic of the first and the second outer layer is 100% thermoplastic, the plastic of the first and the second exterior inner layer comprises 50 to 80% thermoplastic and 20 to 50% elastomer, and the plastic of the interior inner layer comprises 30 to 70% thermoplastic and 70 to 30% elastomer.

2. The foil composite material according to claim 1, wherein the inner plastic layer comprises an interior layer and a first exterior layer and a second exterior layer.

3. The foil composite material according to claim 1, wherein the inner plastic layer contains the same thermoplastic polymer or mixture of thermoplastic polymers as the first and/or the second outer layer.

4. The foil composite material according to claim 1, wherein the plastic of the first and/or the second outer layer comprises a polyester or a mixture of polyesters, a polycarbonate or a mixture of polycarbonates, or a blend of polyester and polycarbonate.

5. The foil composite material according to claim 1, wherein the at least one thermoplastic elastomer of the inner layer comprises a urethane elastomer.

6. The foil composite material according to claim 1, wherein the plastic of the first and/or the second outer layer comprises a PET copolyester, the thermoplastic elastomer of the inner layer comprises an elastomer with a Shore D hardness of 35 to 50.

7. The foil composite material according to claim 1, wherein the thermoplastic elastomer comprises an elastomer that has a Shore D hardness between 40 and 70, and/or an elongation at break between 300% and 700%, and/or a melt viscosity of 7 to 10 cm3/10 min, and/or a processing temperature between 190 C. and 240 C.

8. The foil composite material according to claim 1, wherein the thickness of the inner plastic layer constitutes 40 to 80% of the total thickness of the foil composite material.

9. A portable data carrier including a card body, the card body including a plurality of plastic layers laminated to each other, the card body comprising a card core made of at least one inner core layer, and at least two cover layers for covering both surfaces of the card core, wherein at least one of the cover layers and/or at least one outer core layer comprises the foil composite material recited in claim 1.

10. A card body comprising the foil composite material according to claim 1.

11. The foil composite material according to claim 1, wherein the first outer plastic layer or the second outer plastic layer is in direct contact with the inner plastic layer.

12. The foil composite material according to claim 1, wherein the plastic of the first and/or the second outer layer comprises a polycarbonate, the thermoplastic elastomer of the inner layer comprises an elastomer with a Shore D hardness of 50 to 70.

13. The foil composite material according to claim 1, wherein the at least one thermoplastic elastomer is a thermoplastic urethane elastomer.

14. The foil composite material according to claim 13, wherein the thermoplastic urethane elastomer is based on aromatic esters or ethers.

15. The foil composite material according to claim 13, wherein the mixture of at least one thermoplastic elastomer and at least one thermoplastic polymer includes a UV stabilizer.

16. A foil composite material comprising: at least one first outer plastic layer, at least one inner plastic layer, at least one second outer plastic layer, wherein all the layers jointly form a coextruded composite, the plastic of the at least one first outer layer being a thermoplastic polymer or a mixture of thermoplastic polymers, the plastic of the at least one inner layer being a mixture of at least one thermoplastic elastomer and at least one thermoplastic polymer, the plastic of the at least one second outer layer being a thermoplastic polymer or a mixture of thermoplastic polymers, wherein the foil composite material is opaque and comprises a first outer plastic layer, a first exterior inner plastic layer, an interior inner plastic layer, a second exterior inner plastic layer and a second outer plastic layer, wherein the material of the first and the second outer plastic layer comprises of 85% to 95% thermoplastic and 5 to 15% filler, the material of the first and the second exterior inner plastic layer comprises 20 to 50% elastomer, 75 to 25% thermoplastic and 5 to 15% filler, and the material of the interior inner plastic layer comprises of 50 to 70% elastomer, 15 to 45% thermoplastic and 5 to 15% filler.

17. The foil composite material according to claim 16, wherein the inner plastic layer comprises an interior layer and a first exterior layer and a second exterior layer.

18. A portable data carrier including a card body, the card body including a plurality of plastic layers laminated to each other, the card body comprising a card core made of at least one inner core layer, and at least two cover layers for covering both surfaces of the card core, wherein at least one of the cover layers and/or at least one outer core layer comprises the foil composite material recited in claim 16.

19. A card body comprising the foil composite material according to claim 16.

20. The foil composite material according to claim 16, wherein the first outer plastic layer or the second outer plastic layer is in direct contact with the inner plastic layer.

Description

DESCRIPTION OF THE DRAWINGS

(1) The invention will hereinafter be illustrated further on the basis of figures. It is pointed out that the figures are not true to proportion and not true to scale. Moreover, it is pointed out that the figures are only intended to explain the invention more closely and are by no means to be understood as restrictive. Identical reference numbers designate identical elements.

(2) There are shown:

(3) FIG. 1 a section through a foil composite material according to the invention having an inner plastic layer which consists of an interior inner layer and two exterior inner layers, a first outer plastic layer and a second outer plastic layer,

(4) FIG. 2 a section through a foil composite material according to the invention having an inner plastic layer, a first outer plastic layer and a second outer plastic layer,

(5) FIG. 3 a section through a foil composite material according to the invention having an inner plastic layer which consists of an interior inner layer and two exterior inner layers, as well as having two first outer plastic layers and two second outer plastic layers,

(6) FIG. 4 a section through a card body according to the invention having two foil composite materials according to the invention as cover layers and having a chip module,

(7) FIG. 5 a section through a card body according to the invention having two foil composite materials according to the invention as partial layers of the card core and having a chip module, and

(8) FIG. 6 a section through a card body according to the invention having two foil composite materials according to the invention as cover layers, as well as two foil composite materials according to the invention as partial layers of the card core, and having a chip module.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(9) FIG. 1 shows a first embodiment of a foil composite material 4 according to the invention in cross section. In this embodiment, the inner plastic layer consists of an interior partial layer 31, a first exterior partial layer 32 and a second exterior partial layer 33. Located thereon are a first outer plastic layer 1 and a second outer plastic layer 2. These outer plastic layers contain as the plastic component (besides any additives that might be present) a thermoplastic polymer or a mixture of thermoplastic polymers. The inner layers 31, 32, 33 contain as the plastic component (besides any additives that might be present) respectively a mixture of at least one thermoplastic elastomer and at least one thermoplastic polymer. The interior inner layer 31 has a higher content of thermoplastic elastomer than the exterior inner layers 32, 33. In the inner layer 3 or the partial layers 31, 32, 33 there is used the same thermoplastic polymer or mixture of thermoplastic polymers as in the outer layers 1, 2. Through the gradation in the compositions of the layers from pure thermoplastic on the outside to a mixture with a high elastomer content in the innermost layer, respective neighboring layers are relatively similar to each other or approximated to each other, and upon extrusion there can be obtained a homogeneous superimposition of the melt layers and a good mutual adhesion of the individual partial layers.

(10) The manufacture of the foil composite material 4 can be effected for example by melting granules with three different compositions or compoundings (granules A for the first and the second outer plastic layer 1, 2; granules B for the first and the second exterior inner plastic layer 32, 33; granules C for the interior inner plastic layer 31) in three extruders A, B, C, and respectively extruding the corresponding molten streams (material A from extruder A, material B from extruder B, material C from extruder C) through a wide slot nozzle and merging them into the represented layer construction. Alternatively, it is possible to merge the layers in the feedblock prior to extruding through the wide slot nozzle. Further, there is the alternative possibility of merging the layers only in the wide slot nozzle, a so-called multi-channel nozzle, itself, prior to the melt discharge. In the represented embodiment, the foil composite material is symmetrical in construction, i.e. the outer layers 1, 2 and the partial layers of the inner layer 32, 33 respectively have the same composition and the same thickness. This is not necessary, however. In the case of asymmetrical foil composite materials, a corresponding greater number of extruders and a different corresponding feedblock constellation are required for manufacture.

(11) Hereinafter there will be stated some concrete exemplary formulations for a transparent foil composite material and an opaque foil composite material.

(12) Transparent foil, material thickness 105 to 110 m, layer thickness ratio 1/32/31/33/2=10/20/40/20/10:

(13) Layers 1, 2: 4% S462+4% S465+92% PETG

(14) Layers 32, 33: 4% S465+32% 9665 DU+64% PETG

(15) Layer 31: 4% S465+65% 9665 DU+31% PETG

(16) Opaque foil, material thickness 120 m, layer thickness ratio 1/32/31/33/2=10/20/40/20/10:

(17) Layers 1, 2: 20% S469-YE+80% PETG

(18) Layers 32, 33: 55% PETG+25% DP 9665 DU+20% S469-YE

(19) Layer 31: 30% PETG+50% DP 9665 DU+20% S469-YE

(20) Desmopan 9665 DU, from the company Bayer Material Science, is a thermoplastic elastomer based on urethane (ether type) with a Shore D hardness of 75 (Shore A hardness 98) and an elongation at break of 350% (foil M5e). It is UV-stabilized, resistant to microbes and to hydrolysis.

(21) S469-YE from the company Sukano is a white additive.

(22) S462 from the company Sukano is an antiblocking agent.

(23) S465 from the company Sukano is a laser additive.

(24) Hereinafter there will be stated some exemplary extruder settings for manufacturing the foil composite material 4.

(25) Processing Parameters:

(26) TABLE-US-00001 Preferred processing temperatures Extruder C Zone 1 Zone 2 Zones 3 to n Melt pipes, pump, filter Feedblock/Nozzle 30 C.-80 C. 180 C.-270 C. 190 C.-270 C. 190 C.-270 C. 190 C.-270 C.

(27) TABLE-US-00002 Particularly preferred processing temperatures Extruder C Zone 1 Zone 2 Zones 3 to n Melt pipes, pump, filter Feedblock/Nozzle 40 C.-70 C. 200 C.-250 C. 210 C.-250 C. 210 C.-250 C. 220 C.-250 C.

(28) TABLE-US-00003 Preferred processing temperatures Extruder B Zone 1 Zone 2 Zones 3 to n Melt pipes, pump, filter Feedblock/Nozzle 30 C.-70 C. 190 C.-270 C. 200 C.-270 C. 200 C.-270 C. 200 C.-270 C.

(29) TABLE-US-00004 Particularly preferred processing temperatures Extruder B Zone 1 Zone 2 Zones 3 to n Melt pipes, pump, filter Feedblock/Nozzle 40 C.-60 C. 200 C.-260 C. 210 C.-260 C. 210 C.-260 C. 210 C.-260 C.

(30) TABLE-US-00005 Preferred processing temperatures Extruder A Zone 1 Zone 2 Zones 3 to n Melt pipes, pump, filter Feedblock/Nozzle 30 C.-70 C. 200 C.-280 C. 200 C.-280 C. 200 C.-280 C. 200 C.-280 C.

(31) TABLE-US-00006 Particularly preferred processing temperatures Extruder A Zone 1 Zone 2 Zones 3 to n Melt pipes, pump, filter Feedblock/Nozzle 40 C.-60 C. 210 C.-260 C. 210 C.-260 C. 210 C.-260 C. 210 C.-260 C.

(32) The respective favorable extruder settings can vary in dependence on the extruders used (throughput, screw geometries). They provide information for orientation, which a person skilled in the art can optionally adapt to the given extruder configurations by a few routine tests.

(33) FIG. 2 shows another embodiment of the foil composite material 4 according to the invention. This embodiment has the simplest layer construction with a single inner layer 3 and two outer layers 1, 2. The outer layers 1, 2 consist in turn of a thermoplastic polymer or a mixture of thermoplastic polymers. As in all embodiments, polyester, polyester mixtures, in particular PETG, polycarbonate, polycarbonate mixtures and blends of polyester and polycarbonate are preferred thermoplastic polymers. The inner layer 3 consists of a mixture of at least one thermoplastic elastomer, preferably an elastomer based on urethane, with a proportion of thermoplastic polymer. The thermoplastic polymer used for the inner layer 3 is identical with the thermoplastic polymer or polymer mixture that is used for the outer layers 1, 2. For all embodiments of the foil composite material according to the invention, urethane elastomers based on aromatic esters or aromatic ethers are particularly preferred because of their special suitability for coextrusion with thermoplastics. They are very particularly preferred for an only three-layered foil composite material as represented in FIG. 2, because there are fewer possibilities for gradation with only a single inner layer than for example with a three-layered inner layer as represented in FIG. 1. Hence, it is more difficult to create compatible transitions between the individual layers.

(34) FIG. 3 shows a further embodiment of the foil composite material 4 according to the invention wherein the inner layer 3 is constructed as in the foil composite material represented in FIG. 1, but the first outer layer 1 and the second outer layer 2 are respectively constructed from an exterior outer layer 12, 22 and an interior outer layer 11, 21. The foil composite material thus has altogether seven layers. As a general rule, the manufacture of the foil composite material is the more difficult the more layers the foil composite material has. Hence, variants with outer layers 1, 2 that are constructed from several partial layers are less preferred. They are expedient primarily when there is to be incorporated into an exterior partial layer 12, 22 a constituent that is incompatible with a constituent of the inner layer 3, or when for example a separate partial layer is to be equipped with an antiblocking agent. The corresponding admixtures are then present only in the exterior first outer layer 12 and/or the exterior second outer layer 22.

(35) FIGS. 4, 5 and 6 respectively show exemplary layer constructions for card bodies 5 according to the invention. In general, card bodies according to the invention consist of a card core 6 which is typically constructed from one to seven layers. In the figures there are respectively represented three core layers, an inner core layer 9, a first outer core layer 7 and a second outer core layer 7. In card bodies of the prior art, the card cores consist of thermoplastic foils, typically made of PVC, PET, ABS, polyester, PC, PEC and the like. Such foils can also be used for card cores according to the invention. Between the foil layers and/or in recesses of the foil layers there can be located electronic components such as electronic modules and antennas. Other features, such as for example security elements or imprints, can also be provided. The layer construction of the card bodies 5 is respectively completed on the outer side by a cover layer 8, 8. The foils forming the layer construction are preferably interconnected by laminating, which is why all materials used should be readily laminatable to each other.

(36) FIG. 4 shows an embodiment of a card body 5 according to the invention having a card core 6, consisting of a PVC or PET foil 9 onto which a coil (not shown) is imprinted, and two PVC films 7, 7. The layer construction is completed by the two cover foils 8, 8 which consist of the foil composite material 4 according to the invention, as was described hereinabove.

(37) In recesses of the foils 7, 8 there is located a chip module 15 which is glued to the card body by means of a module pad 16 made of module adhesive. Contacts 17 establish the electrical contact to the coil (not shown) imprinted onto the foil 9.

(38) When the foil composite material 4 according to the invention is used as a cover layer (overlay foil), as represented in FIG. 4, it is preferably transparent. The use of the foil composite material according to the invention exclusively as a cover layer has the advantage that the gluing of the chip module 15 is effected exclusively to standard card foils, so that the usual standard module adhesive can still be used for the module pad 16.

(39) FIG. 5 shows another embodiment of a card body 5 according to the invention. Here the card core 6 consists of a PVC or PET foil 9 with an imprinted antenna coil (not shown) which is adjoined on both sides by the layers 7, 7 made of the foil composite material 4 according to the invention. The layer construction is completed by the two cover layers 8, 8 made of PVC foil. As in the embodiment represented in FIG. 4, a chip module 15 is glued into the card body 5 by means of a module pad 16 and has contacts 17 for contacting the antenna coil.

(40) When the foil composite material 4 according to the invention forms a partial layer or partial layers of the core 6, as in the embodiment represented in FIG. 5, it is preferably of opaque design. This embodiment has the advantage that the foil composite material according to the invention, because it is located in the gluing region of the chip module, can especially well compensate stresses that are built up in the material through the action of temperature (hot-melt gluing) upon implanting of the module.

(41) A further alternative embodiment of a card body 5 according to the invention is represented in FIG. 6. Here, the card core 6 consists of the inner core layer 9 made of PVC or PET foil, the first outer core layer 7 and the second outer core layer 7, both made of foil composite material 4 according to the invention in opaque design. The two cover layers 8, 8 likewise consist of foil composite material 4 according to the invention, this time in transparent design. A chip module 15 is implanted into the card body and glued as in the embodiments of FIG. 4 and FIG. 5. This embodiment with foil composite material 4 according to the invention both as a partial core layer and as a cover layer gives the card body 5 especially advantageous mechanical properties. On the one hand, stresses built up through the action of temperature upon implanting of the module are compensated well by the partial core layers according to the invention, and, on the other hand, the far outwardly located cover foils 8, 8 made of foil composite material 4 according to the invention ensure a high breaking strength, lack of tendency to block, good printability and stiffness.

(42) In FIGS. 4, 5 and 6, the card constructions are respectively represented symmetrically, but this is not necessary. Embodiments are for example also possible wherein the foil composite material 4 according to the invention is used only as one of the cover layers and/or as a partial core layer. Upon use as a cover layer, the layer thickness of the foil composite material 4 is typically no more than half as great as upon the use as a partial core layer.

(43) Through the employment of the foil composite material according to the invention as a cover layer (or cover layers) and/or as a core layer (or core layers) in a card body, the mechanical properties of card bodies can be decisively improved over card bodies of the prior art. The card bodies can be subjected to stronger and more frequent bending loads without there occurring stresses, cracks or breaks of the card body. Stresses arising from the installation of electronic modules, which always cause a weakening of the card body, can also be compensated and thus the mechanical properties of the card body improved. The foil composite material according to the invention can be employed in the card bodies instead of any standard foil.

(44) In particular card constructions wherein the foil composite material according to the invention is employed in the interior of the card construction, as represented by way of example in FIG. 5, have excellent mechanical properties, such as excellent strength and stiffness. This becomes evident particularly in the case of actions of impact force, which otherwise as a rule lead to card breakage. This is due to the greater thickness of the foil composite material core layers, and thus the higher proportion of the foil composite material according to the invention in the card body altogether.

(45) The foil composite material according to the invention is also very stable in itself, i.e. there is a firm bond between its individual partial layers without any danger of the partial layers separating from each other upon load. This stability is achieved by suitable gradations of the compositions of the partial layers which result in similar processing properties of neighboring partial layers.

(46) The foil composite material according to the invention can be manufactured inexpensively, and there is a wide spectrum of suitable thermoplastic elastomers with different properties available on the market. The foil composite material is easy to process by the coextrusion method and is also characterized by especially simple handling in further processing, i.e. it can for example be printed without any problems and laminated to all common card materials. It also does not tend to block. The foil material can be manufactured with a high proportion of thermoplastic elastomer, which makes it very elastic and, upon use as a layer in a card body, considerably improves the mechanical properties of the card body over card bodies without the foil composite material according to the invention.