Coextruded foil composite material and its use in card bodies

1. A foil composite material for a card body of a portable data carrier, the foil composite material comprising:

an inner layer formed between a first outer layer and a second outer layer, wherein

the first outer layer, the inner layer, and the second outer layer jointly form a coextruded composite,

within the coextruded composite, the first outer layer is in direct contact with a first surface of the inner layer, and the second outer layer is in direct contact with a second surface of the inner layer, the second surface of the inner layer being opposite from the first surface of the inner layer,

the first outer layer includes at least a first partial layer and a second partial layer, the second partial layer being between the first partial layer and the inner layer, the first partial layer containing 95 wt. % or more polyethylene terephthalate glycol copolymer (PETG),

the inner layer consists essentially of 100% of a single thermoplastic copolyester elastomer (TPC) material or consists essentially of a plurality of inner plastic layers, each of the plurality of inner plastic layers consisting essentially of a same thermoplastic copolyester elastomer (TPC), and

the second outer layer comprises polyethylene terephthalate glycol copolymer (PETG),

wherein the first outer layer, the inner layer, and the second outer layer jointly form a coextruded composite formed by the materials of each of the first outer layer, the inner layer, and the second outer layer are coextruded by being merged into said coextruded composite before leaving an extruder nozzle, and

wherein the inner layer constitutes 60 to 80% of a total thickness of the foil composite material,

wherein a thickness of each of the first outer layer and the second outer layer is in the range of 10 μm to 70 μm, and

wherein the first partial layer and the second partial layer of the first outer layer include a mixture of PETG and TPC and the content of TCP is higher in the second partial layer than in the first partial layer and the content of PETG is higher in the first partial layer than in the second partial layer.

2. The foil composite material according to claim 1 , wherein the first layer of the first outer layer contains an antiblocking agent in the range of up to and including 5 wt. %.

3. The foil composite material according to claim 1 , wherein the first outer layer further includes a second layer, the second layer of the first outer layer being an interior layer formed closer to the inner layer than the first layer of the first outer layer is to the inner layer.

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

5. The foil composite material according to claim 1 , wherein one or more of the first outer layer, the inner layer, and the second outer layer contains one or more additives selected from the group consisting of fillers, color pigments, oxidation stabilizers, UV stabilizers, laser additives, flame retardants, and optical brighteners.

6. The foil composite material according to claim 1 , wherein the foil composite has a thickness between 50 μm and 350 μm.

7. The foil composite material according to claim 1 , wherein the thermoplastic copolyester elastomer is a copolyester elastomer of polyether.

8. The foil composite material according to claim 1 , wherein the thermoplastic copolyester elastomer has a Shore D hardness of 33 to 55.

9. The foil composite material according to claim 1 , wherein the thermoplastic copolyester elastomer has an elongation at break greater than 300%.

10. The foil composite material according to claim 1 , wherein the thermoplastic copolyester elastomer has a melting viscosity (MFI) of 7 to 11cm 3 /10 min.

11. The foil composite material according to claim 1 , having a mutual adhesive strength of the layers of at least 30 N/cm.

12. The foil composite material according to claim 1 , wherein the first layer of the first outer layer contains 96 wt. % polyethylene terephthalate glycol copolymer (PETG).

13. The foil composite material according to claim 1 , wherein the first outer layer further includes a second layer that contains 100 wt. % polyethylene terephthalate glycol copolymer (PETG).

14. The foil composite material according to claim 13 , wherein the second layer of the first outer layer is an interior layer formed closer to the inner layer than the first layer of the first outer layer is to the inner layer.

15. The foil composite material according to claim 14 , wherein the second outer layer further includes a second layer that contains 100 wt. % polyethylene terephthalate glycol copolymer (PETG).

16. The foil composite material according to claim 1 , wherein the second outer layer includes a first layer that contains 95 wt. % or more polyethylene terephthalate glycol copolymer (PETG).

17. The foil composite material according to claim 16 , wherein the first layer of the second outer layer contains an antiblocking agent in the range of up to and including 5 wt. %.

18. The foil composite material according to claim 16 , wherein the second outer layer further includes a second layer, the second layer of the second outer layer being an interior layer formed closer to the inner layer than the first layer of the second outer layer is to the inner layer.

19. A data card body of a portable data carrier comprising:

a card core including at least one core layer,

a first cover layer covering a first surface of the card core, and

a second cover layer covering a second surface of the card core,

wherein at least one of the first cover layer or the second cover layer or at least one intermediate layer comprises a foil composite material, the foil composite material including

an inner layer formed between a first outer layer and a second outer layer, wherein the first outer layer, the inner layer, and the second outer layer jointly form a coextruded composite,

within the coextruded composite, the first outer layer is in direct contact with a first surface of the inner layer, and the second outer layer is in direct contact with a second surface of the inner layer, the second surface of the inner layer being opposite from the first surface of the inner layer,

the first outer layer includes at least a first partial layer and a second partial layer, the second partial layer being between the first partial layer and the inner layer, the first layer containing 95 wt. % or more polyethylene terephthalate glycol copolymer (PETG),

the inner layer consists essentially of 100% of a single thermoplastic copolyester elastomer (TPC) material or consists essentially of a plurality of inner plastic layers, each of the plurality of inner plastic layers consisting essentially of a same thermoplastic copolyester elastomer (TPC), and

the second outer layer comprises polyethylene terephthalate glycol copolymer (PETG),

wherein the first outer layer, the inner layer, and the second outer layer jointly form a coextruded composite formed by the materials of each of the first outer layer, the inner layer, and the second outer layer are coextruded by being merged into said coextruded composite before leaving an extruder nozzle,

wherein the inner layer constitutes 60 to 80% of a total thickness of the foil composite material

wherein a thickness of each of the first outer layer and the second outer layer is in the range of 10 μm to 70 μm, and

wherein the first partial layer and the second partial layer of the first outer layer include a mixture of PETG and TPC and the content of TCP is higher in the second partial layer than in the first partial layer and the content of PETG is higher in the first partial layer than in the second partial layer.