Multi-layered polymer film

1. A multi-layered polymer film, comprising a sealing layer and a base layer,

wherein the sealing layer comprises a polypropylene, and

wherein the sealing layer polypropylene SL-PP

comprises comonomer units derived from ethylene in an amount of from 0.5 wt % to 25 wt %, and from at least one C 5-12 alpha-olefin in an amount of from 0.5 mol % to 4.0 mol %, and

has an amount of xylene solubles XS of at least 20 wt %, and the xylene solubles have an amount of ethylene-derived comonomer units of from 4 wt % to 50 wt % and an amount of comonomer units which are derived from the at least one C 5-12 alpha-olefin of from 0.01 mol % to 2.0 mol %.

2. The multi-layered polymer film according to claim 1 , wherein the at least one C 5-12 alpha-olefin is selected from 1-hexene, 1-octene, or any mixture thereof.

3. The multi-layered polymer film according to claim 1 , wherein the sealing layer polypropylene complies with the following relation:

[ C 2 (XS)×XS/100 ]/C 2 (total)≥0.90

wherein

C 2 (XS) is the amount in wt % of the ethylene-derived comonomer units in the xylene solubles of the sealing layer polypropylene,

XS is the amount in wt % of xylene solubles of the sealing layer polypropylene,

C 2 (total) is the amount in wt % of the ethylene-derived comonomer units in the sealing layer polypropylene.

4. The multi-layered polymer film according to claim 1 , wherein the sealing layer polypropylene complies with the following relation:

[ C 5-12 (XS)×XS/100 ]/C 5-12 (total)≤0.30

wherein

C 5-12 (XS) is the amount in wt % of the C 5-12 alpha-olefin-derived comonomer units in the xylene solubles of the sealing layer polypropylene,

XS is the amount in wt % of xylene solubles of the sealing layer polypropylene,

C 5-12 (total) is the amount in wt % of the C 5-12 alpha-olefin-derived comonomer units in the sealing layer polypropylene.

5. The multi-layered polymer film according to claim 1 , wherein the total amount of comonomer units in the sealing layer polypropylene is from 1.7 mol % to 33 mol %.

6. The multi-layered polymer film according to claim 1 , wherein the sealing layer polypropylene is a blend comprising the following propylene polymer fractions P1, P2 and P3:

(P1) a propylene homopolymer or a propylene copolymer comprising comonomer units derived from at least one C 5-12 alpha-olefin in an amount of less than 1.0 mol%,

(P2) a propylene copolymer comprising comonomer units derived from at least one C 5-12 alpha-olefin in an amount of from 2.0 mol % to 7.0 mol %, and

(P3) a propylene copolymer comprising ethylene-derived comonomer units in an amount of from 4 wt % to 50 wt %.

7. The multi-layered polymer film according to claim 1 , having a sealing initiation temperature SIT of 110° C. or less.

8. The multi-layered polymer film according to claim 1 , wherein the base layer comprises a polyvinyl alcohol, a poly(meth)acrylate, a polyamide, a poly(ethylene terephthalate), a polyolefin, or any mixture thereof.

9. The multi-layered polymer film according to claim 1 , wherein the base layer comprises a polypropylene.

10. The multi-layered polymer film according to claim 1 , wherein the base layer has a thickness in the range of 5 to 120 μm, and/or the sealing layer has a thickness in the range of 3 to 40 μm.

11. The multi-layered polymer film according to claim 1 , wherein the multi-layered polymer film comprises three layers, namely a base layer, a sealing layer and

(a) an outer layer being a polyolefin,

or

(b) a further sealing layers,

or

(c) a metal layer,

wherein the multi-layered polymer film has the following layer sequence:

(a1) sealing layer-base layer-outer layer,

or

(b1) sealing layer-base layer-sealing layer,

or

(c1) sealing layer-base layer-metal layer.

12. The multi-layered polymer film according to claim 1 , being a cast film, a blown film, a biaxially oriented film, or a combination thereof.

13. The multi-layered polymer film according to claim 1 , wherein the xylene solubles of the sealing layer polypropylene contain an amount of comonomer units which are derived from the least one C 5-12 alpha-olefin of from 0.05 mol % to 1.0 mol %.

14. The multi-layered polymer film according to claim 1 , wherein the total amount of comonomer units, derived from ethylene and at least one C 5-12 alpha-olefin, in the sealing layer polypropylene is from 1.7 mol % to 33 mol %.

15. The multi-layered polymer film according to claim 1 , wherein the total amount of comonomer units in the sealing layer polypropylene is from 2.5 mol % to 14 mol %.

16. The multi-layered polymer film according to claim 1 , wherein the total amount of comonomer units, derived from ethylene and at least one C 5-12 alpha-olefin, in the sealing layer polypropylene is from 2.5 mol % to 14 mol %.

17. The multi-layered polymer film according to claim 1 , wherein the sealing layer polypropylene is a reactor blend comprising the following propylene polymer fractions P1, P2 and P3:

(P1) a propylene homopolymer or a propylene copolymer comprising comonomer units derived from at least one C 5-12 alpha-olefin in an amount of less than 1.0 mol %,

(P2) a propylene copolymer comprising comonomer units derived from at least one C 5-12 alpha-olefin in an amount of from 2.0 mol % to 7.0 mol %, and

(P3) a propylene copolymer comprising ethylene-derived comonomer units in an amount of from 4 wt % to 50 wt %.

18. The multi-layered polymer film according to claim 1 , having a sealing initiation temperature SIT of 105° C. or less.

19. The multi-layered polymer film according to claim 1 , wherein the multi-layered polymer film consists of three layers, namely a base layer, a sealing layer and

(a) an outer layer being a polyolefin,

or

(b) a further sealing layers,

or

(c) a metal layer,

wherein the multi-layered polymer film has the following layer sequence:

(a1) sealing layer-base layer-outer layer,

or

(b1) sealing layer-base layer-sealing layer,

or

(c1) sealing layer-base layer-metal layer.

20. The multi-layered polymer film according to claim 10 , wherein the ratio of the sealing layer thickness to the base layer thickness being in the range of from 1/10 to 9/10.