Robust planar composite with an intermediate layer of increased vicat softening temperature

1. A sheetlike composite comprising a layer configuration with the following layers:

o. optionally a layer of thermoplastic KSu;

i. a carrier layer;

ii. a first layer of thermoplastic KSv;

iii. a barrier layer;

iv. a second layer of thermoplastic KSa; and

v. at least one further layer of thermoplastic KSw;

wherein the Vicat softening temperature of the layer of thermoplastic KSv and the Vicat softening temperature of the layer of thermoplastic KSa is in each case higher than the Vicat softening temperature of the layer of thermoplastic KSw.

2. The sheetlike composite according to claim 1 , wherein the Vicat softening temperature of the layer of thermoplastic KSv and the Vicat softening temperature of the layer of thermoplastic KSa is in each case higher than the Vicat softening temperature of the layer of thermoplastic KSw by at least 4 K.

3. The sheetlike composite according to claim 1 , wherein the melting temperature of the layer of thermoplastic KSv and the melting temperature of the layer of thermoplastic KSa is in each case higher than the melting temperature of the layer of thermoplastic KSw.

4. The sheetlike composite according to claim 3 , wherein the melting temperature of the layer of thermoplastic KSv and the melting temperature of the layer of thermoplastic KSa is in each case higher than the melting temperature of the layer of thermoplastic KSw by at least 3 K.

5. The sheetlike composite according to claim 1 , wherein the modulus of the difference between the Vicat softening temperature of the layer of thermoplastic KSv and the Vicat softening temperature of the layer of thermoplastic KSa is in a range of from 0 to 10 K.

6. The sheetlike composite according to claim 1 , wherein the modulus of the difference between the melting temperature of the layer of thermoplastic KSv and the melting temperature of the layer of thermoplastic KSa is in a range of from 0 to 10 K.

7. The sheetlike composite according to claim 1 , wherein at least one of the layers of thermoplastic KSu, KSv, KSa or KSw is made of a polyethylene or a polypropylene or a mixture of at least two of these.

8. The sheetlike composite according to claim 1 , wherein at least one of the layers of plastic KSu, KSv, KSa or KSw comprises at least one polyolefin with a mass density in a range of from 0.925 g/cm 3 to 0.980 g/cm 3 in a range of from 20 wt. % to 100 wt. %, in each case based on the total weight of the layer of plastic.

9. The sheetlike composite according to claim 1 , wherein the barrier layer is chosen from

a. a barrier layer of plastic, or

b. a metal layer, or

c. a metal oxide layer, or

d. a combination of at least two of a. to c.

10. The sheetlike composite according to claim 1 , wherein the carrier layer has at least one hole which is covered at least with the barrier layer and at least with one of the layers of thermoplastic KSa or KSw as hole-covering layers.

11. A container surrounding an interior, comprising at least one sheetlike composite according to claim 1 .

12. The sheetlike composite according to claim 1 , wherein at least one of the layers of thermoplastic KSu, KSv, KSa or KSw is a plastics mixture of at least two plastics.

13. The sheetlike composite according to claim 12 , wherein the plastics mixture of at least one layer of thermoplastic contains as one of at least two mixture components a polyolefin prepared by means of a metallocene.

14. A process for the production of a container surrounding an interior, comprising the process steps

a. providing a sheetlike composite comprising a layer configuration with the following layers:

o. optionally a layer of thermoplastic KSu of a plastics composition KSum;

i. a carrier layer;

ii. a first layer of thermoplastic KSv of a plastics composition KSvm;

iii. a barrier layer;

iv. a second layer of thermoplastic KSa of a plastics composition KSam; and

v. a further layer of thermoplastic KSw of a plastics composition KSwm;

wherein the Vicat softening temperature of the plastics composition KSvm and the Vicat softening temperature of the plastics composition KSam is in each case higher than the Vicat softening temperature of the plastics composition KSwm;

b. folding the sheetlike composite to form a fold with at least two fold surfaces adjacent to one another, wherein layer v. faces the interior of the container;

c. joining at least a part region of the at least two fold surfaces to form a container region.

15. The process according to claim 14 , wherein at least one of the layers of thermoplastic KSu, KSv, KSa or KSw in step b. is heated above its melting temperature.

16. The process according to claim 14 , wherein at least one of the layers of thermoplastic KSu, KSv, KSa or KSw in step b. has a temperature which is below its melting temperature.

17. The process according to claim 14 , wherein at least one of the layers of thermoplastic KSu, KSv, KSa or KSw has a melting temperature below the melting temperature of the barrier layer.

18. The process according to claim 14 , wherein the fold surfaces form an angle μ of less than 90°.

19. The process according to claim 14 , wherein the joining according to step c. is carried out by sealing by means of at least one of the layers of thermoplastic KSu, KSa or KSw.

20. The process according to claim 14 , wherein the container is filled with a foodstuff before step b. or after step c.

21. The process according to claim 14 , wherein a further folding follows step c. as step d., and wherein, in the further folding in step d., at least one of the layers of thermoplastic KSu, KSv, KSa or KSw has a temperature which is below the melting temperature of this layer of plastic.

22. The process according to claim 14 , wherein at least one of the layers of thermoplastic KSu, KSv, KSa or KSw is produced by extrusion of at least one polymer P 1 through a slot die to obtain an emerging surface, at least one polymer P 2 which differs from polymer P 1 being provided on the flanks of the emerging surface of the at least one polymer P 1 emerging from the slot die.

23. The process according to claim 22 , wherein the emerging surface is cooled to a temperature below the lowest melting temperature of the polymer P 2 , and at least the flanks of the emerging surface are then separated off from the emerging surface.

24. The process according to claim 14 , wherein at least one of the layers of thermoplastic KSu, KSa or KSw is heated above its melting temperature directly before step c.

25. The process according to claim 24 , wherein the heating is carried out by irradiation, contact with a hot solid or hot gas, or a combination thereof.

26. The process according to claim 24 , wherein the heating is carried out by a mechanical vibration.

27. The process according claim 26 , wherein the heating is carried out by ultrasound.

28. The process according to claim 14 , wherein the sheetlike composite has at least one score and the fold is effected along the score.

29. The process according to claim 28 , wherein the score demarcates the sheetlike composite into a part of large area and a part of small area compared with the part of large area.

30. A container obtainable by a process according to claim 14 .