This application is the U.S. National Phase of PCT International Application PCT/EP2019/053512, filed Feb. 13, 2019, claiming benefit of priority to European Patent Application No. 18159267.6, filed Feb. 28, 2018, the contents of which are incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

In general, the present disclosure relates to the field of chemistry. More specifically, the present disclosure relates to polymer chemistry. In particular, the present disclosure relates to a polymer film, including polymers films for food packaging.

BACKGROUND OF THE INVENTION

In some instances, polypropylene films as well as biaxially oriented polypropylene films (BOPP) are used for the packaging of foodstuff using automatic machines. In some instances, the films have a good balance of processability (“machinability”), optical and mechanical properties, and low permeability to gases and water vapor. In some instances, the gases are oxygen or carbon dioxide.

For the packaging of fresh foods, greater gas transmission rates are sought. Because the metabolic activity of vegetable cells continues after fresh foods are harvested, cleaned and cut into pieces, the cells of the fresh foods continue consuming oxygen and emitting carbon dioxide and water vapor. In a closed package, this process changes the atmosphere inside the package, making the environment detrimental for the metabolic activity yet favorable for the development of harmful micro-organisms.

In some instances, the oxygen and water vapor transmission rate of films made from or containing propylene homopolymers are low and can be increased.

SUMMARY OF THE INVENTION

In a general embodiment, the present disclosure provides a multilayer film made from or containing a core layer made from or containing a polypropylene composition made from or containing:

A) from 90 wt % to 50 wt %; of a propylene homopolymer having a fraction insoluble in xylene at 25° C. greater than 90 wt %, based upon the total weight of the propylene homopolymer; and

B) from 10 wt % to 50 wt %; of a propylene ethylene copolymer having:

i) xylene soluble fraction at 25° C. ranging from 14 wt % to 27 wt %, based upon the total weight of the propylene ethylene copolymer;

ii) intrinsic viscosity of the fraction soluble in xylene at 25° C. ranging from 1.0 to 2.4 dl/g;

iii) melt flow rate, MFR, measured according to ISO 1133 at 230° C. with a load of 2.16 kg, ranging from 1.0 g/10 min to 4.0 g/10 min;

iv) an ethylene derived units content ranging from 5.0 wt % to 12.0 wt %, based upon the total weight of the propylene ethylene copolymer;

v) the ethylene derived units content on the fraction insoluble in xylene at 25° C. ranging from 2.5 wt % to 6.0 wt %, based upon the total weight of the propylene ethylene copolymer;

vi) the ethylene derived units content on the fraction soluble in xylene at 25° C. ranging from 15.2. wt % to 30.2 wt %, based upon the total weight of the propylene ethylene copolymer; and

vii) the C13NMR sequences PEP measured on the fraction insoluble in xylene at 25° C. ranging from 3.5 mol % to 5.5 mol % and the C13NMR sequences PEP measured on the fraction soluble in xylene at 25° C. ranging from 11.0 mol % to 14.2 mol %;

the sum of the amounts of A) and B) being 100 wt %.

