Multilayer polyproylene film

1. Multilayer film comprising

at least a skin layer, a core layer and an inner layer,

the skin layer comprising a homo polypropylene or a random propylene ethylene copolymer including up to 2.5 wt. % units derived from ethylene, the homo polypropylene or the random propylene ethylene copolymer having a MFR 2 (ISO1133, 230° C.) of 2.0 to 20 g/10 min and a melting temperature (Tm) of above 148° C. measured by DSC according to ISO 11357-3:1999 and a scan rate of 10° C./min;

the core layer comprising a mixture obtainable by melt blending 20 to 100 wt. % of a random heterophasic copolymer and 0 to 80 wt. % of styrene based thermoplastic elastomer (TPE),

whereby the random heterophasic copolymer has a melting temperature (Tm) of 134° C. 148° C. measured by DSC according to ISO 11357-3:1999 and a scan rate of 10° C./min and includes a propylene ethylene copolymer rubber; and

whereby the styrene based TPE has a styrene content of from 5 to 20 wt. %, and

the inner layer comprising a random propylene ethylene copolymer having a melting temperature (Tm) from 132° C. to 144° C. measured by DSC according to ISO 11357-3:1999 and a scan rate of 10° C./min,

wherein the multilayer film is free of phthalic acid esters as well as decomposition products thereof.

2. Multilayer film according to claim 1 , whereby xylene cold soluble fraction (XCS) of the random heterophasic copolymer contributing to the core layer has an intrinsic viscosity of 1.0 to 2.0 dl/g (DIN ISO 1628/1, 10/1999; Decalin, 135° C.).

3. Multilayer film according to claim 1 , in which the random heterophasic copolymer of the core layer is a random heterophasic copolymer of propylene.

4. Multilayer film according to claim 1 , which has a total thickness of 150 to 250 micrometer determined according to ISO4593.

5. Multilayer film according to claim 1 , whereby the core layer has a thickness of 70 to 85% with respect to the thickness of the multilayer film.

6. Multilayer film according to claim 1 , whereby the thicknesses of the skin layer is 10 to 15% with respect to the total thickness of the multilayer film,

and whereby the thicknesses of the inner layer is 10 to 15% with respect to the total thickness of the multilayer film.

7. Multilayer film according to claim 1 , whereby:

the skin layer consists of the homo polypropylene or random propylene ethylene copolymer; and/or

the core layer consists of a mixture obtainable by melt blending 20 to 100 wt. % of a random heterophasic copolymer and 0 to 80 wt. % of styrene based TPE.

8. Multilayer film according to claim 1 , whereby:

the inner layer consists of the random propylene ethylene copolymer,

or

the inner layer consists of

a mixture obtainable by blending the random propylene ethylene copolymer and a propylene ethylene elastomer having an ethylene content of less than 20 wt. %;

or the inner layer consists of

a mixture obtainable by blending the random propylene ethylene copolymer and a styrene ethylene butylene styrene copolymer (SEBS).

9. Multilayer film according to claim 1 ,

whereby the propylene homopolymer of the skin layer has an MFR (230° C., 2.16 kg, ISO1133) of 4.0 to 13 g/10 min,

and/or

a melting temperature of above 162° C. measured by DSC according to ISO 11357-3:1999 and a scan rate of 10° C./min,

and/or

a flexural modulus of above 1450 MPa when measured on injection molded specimens (23° C., 50% humidity, ISO 178),

or

the random propylene ethylene copolymer of the skin layer has,

an MFR (230° C., 2.16 kg, ISO1133) of 4.0 to 13 g/10 min,

an ethylene content of 0.5 to 2.2 wt. %

and/or,

a melting temperature of 152 to 155° C. measured by DSC according to ISO 11357-3:1999 and a scan rate of 10° C./min,

and/or,

a flexural modulus of above 975 MPa when measured on injection molded specimens (23° C., 50% humidity, ISO 178).

10. Multilayer film according to according to claim 1 ,

whereby the random heterophasic copolymer having a melting temperature (Tm) of 134 to 148° C. measured by DSC according to ISO 11357-3:1999 and a scan rate of 10° C./min contributing to the core layer has,

a MFR 2 of 3.0 to 7.0 g/10 min (ISO 1133, 230° C., 2.16 kg)

and/or

a total ethylene content of 7.0 to 14.0 wt. %

and/or

an amount of the xylene cold soluble fraction (XCS) in the range of 18.0 to 25.0 wt. %

and/or

an intrinsic viscosity of 1.0 to 1.6 dl/g (DIN ISO 1628/1, 10/1999; Decalin, 135° C.) of the xylene cold soluble fraction (XCS).

11. Multilayer film according to claim 1 ,

whereby the propylene ethylene copolymer of the inner layer having a melting temperature (Tm) from 132° C. to 144° C. measured by DSC according to ISO 11357-3:1999 and a scan rate of 10° C./min

has an ethylene content of 3.5 to 6.0 wt. %

and/or

has a melt flow rate of 6.0 to 13.0 g/10 min (230° C., 2.16 kg, ISO1133),

and/or

a flexural modulus of from 600 to 900 MPa when measured on injection molded specimens (23° C., 50% humidity, ISO 178).

12. Multilayer film according to claim 1 ,

whereby the core layer comprises a mixture obtainable by melt blending 40 to 91 wt. % of a random heterophasic copolymer and 9 to 60 wt. % of styrene based TPE.

13. Multilayer film according to claim 1 ,

whereby the core layer comprises a mixture obtainable by melt blending 45 to 65 wt. % of a random heterophasic copolymer and 35 to 55 wt. % of styrene based TPE.

14. Pouches made from the multilayer film as defined in claim 1 .

15. Process for preparing a film according to claim 1 , comprising:

extruding on a multilayer cast film line the components forming the skin layer, the core layer and the inner layer of claim 1 .