Disposable bag comprising a multilayer film

1. A disposable bag comprising a multilayer film for accommodating a fluid, wherein said multilayer film has a tensile elongation in longitudinal direction of 250% to 850%, and in transverse direction of 300% to 1050% and comprises:

a) a type (A) layer, comprising several components, wherein one component is a styrene-isoprene block copolymer, styrene-ethylene-butylene block copolymer, styrene-ethylene-propylene block copolymer or a mixture thereof, and a further component is polyethylene or a copolymer which comprises ethylene units

and wherein the proportion of the one component in the type (A) layer lies in the range of 35 wt. % to 99.99 wt. %, relative to the total composition of the type (A) layer and

b) two or more type (B) layer(s) comprising several components independently of one another, wherein one component is a styrene-ethylene-butylene block copolymer, styrene-ethylene-propylene block copolymer, styrene-isoprene block copolymer or a mixture thereof, and a further component is a polypropylene or a copolymer which comprises propylene units and

wherein the proportion of the one component in the type (B) layer lies in the range of 55 wt. % to 99.99 wt. % and the proportion of the further component in the type (B) layer is in the range of 1 wt. % to 45 wt. %, relative to the total composition of the type (B) layer and wherein the type (A) layer is a middle layer having a thickness of ≧100 μm and is surrounded by two type (B) layers having a thickness of ≦40 μm.

2. A disposable bag according to claim 1 , wherein the multilayer film has a tear strength in longitudinal direction 300 N/mm 2 to 350 N/mm 2 and in transverse direction 220 N/mm 2 to 270 N/mm 2 .

3. A disposable bag according to claim 1 , wherein the multilayer film has a transverse strain ratio μ in the rubber-elastic state of 0.45 to 0.55.

4. A disposable bag according to claim 1 , wherein the multilayer film can be extended by up to 500% by a force of 45 N/15 mm to 60 N/15 mm.

5. A disposable bag according to claim 1 , wherein the ratio of the external surface of the disposable bag when filled to the maximum to the external surface when unfilled is ≧2/1.

6. A disposable bag according to claim 1 , wherein the holding capacity of the disposable bag when filled to the maximum to the holding capacity in the state in which the multilayer film is present unextended is ≧3/1.

7. A disposable bag according to claim 1 , wherein the holding capacity of the disposable bag when filled to the maximum lies in the range of 30 L to 120 L.

8. A disposable bag according to claim 1 which contains several chambers.

9. A disposable bag according to claim 8 , wherein the chambers are arranged alongside one another in longitudinal direction of the disposable bag.

10. A disposable bag according to claim 8 , wherein at least one chamber has a feed line and a drainage line is attached to a different chamber.

11. A disposable bag according to claim 1 , wherein the multilayer film comprises a type (A) layer, which contains several components, wherein one of the components is a styrene-ethylene-butylene block copolymer.

12. A disposable bag according to claim 1 , wherein the proportion of the further component in the type (A) layer lies in the range of 0.01 wt. % to 65 wt. %, relative to the total composition of the type (A) layer.

13. A disposable bag according to claim 1 , wherein the multilayer film comprises one or more type (B) layer(s) which contains several components independently of one another, wherein one of the components is a styrene-ethylene-butylene block copolymer.

14. A disposable bag according to claim 13 , wherein the first component in the type (B) layer has an average molecular weight of ≧120000 g/mol.

15. A method of carrying out a medical treatment comprising using a disposable bag of claim 1 or a support apparatus comprising such a bag.

16. A method according to claim 15 , for carrying out haemodialysis or peritoneal dialysis.

17. A process for the production of a disposable bag according to claim 1 , comprising the following steps:

a) producing said multilayer film;

and

b) welding said multilayer film into a disposable bag.

18. A disposable bag according to claim 1 , wherein the proportion of the one component in said type (A) layer lies in the range of 55 wt. % to 99.99 wt. %.

19. A disposable bag according to claim 1 , wherein the proportion of the one component in said type (A) and said type (B) layer lies in the range of 60 wt. % to 99.99 wt. %.

20. A disposable bag according to claim 1 , wherein layer (A) has a thickness of ≧300 μm.