WO2018069540A1

WO2018069540A1 - Sterilizable packaging material

Info

Publication number: WO2018069540A1
Application number: PCT/EP2017/076264
Authority: WO
Inventors: Sarah Van Mierloo; Bart VAN DEN ESSCHERT; Paul Davidson
Original assignee: Sabic Global Technologies B.V.
Priority date: 2016-10-14
Filing date: 2017-10-15
Publication date: 2018-04-19
Also published as: EP3526039A1; CN110049873A

Abstract

Sterilized packaging material comprising - A. a copolymer of ethylene and at least one α-olefin and/or a copolymer of propylene with an α-olefin and/or mixtures of two or more thereof, and - B. between 50 and 200 ppm by weight of α-tocopherol relative to the component A.

Description

Sterilizable packaging material

The invention relates to a serialized packaging material and comprising a polyethylene and an a-tocopherol.

The stabilization of polyolefins is known in the art.

Suitable stabilisers known in the art are for example synthetic (poly)phenolic compounds such as tetrakis[methylene-3-(3',5')-di-t-butyl-4-hydroxyphenyl)propionate] methane;

octadecyl 3,5-di-t-butyl-4-hydroxyhydrocinnamate; 1 ,1 ,3-tris(2-methyl-4-hydroxy-5-t- butylphenyl)butane; 1 ,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, bis- [3,3-bis-(4'-hydroxy-3'-t-butylphenyl butanoic acid]-glycol ester; tris(3,5-di-t-butyl-4-hydroxy benzyl)isocyanurate; 1 ,3,5-tris(4-t-butyl-2,6-dimethyl-3-hydroxy-benzyl)isocyanurate; 5-di-t- butyl-4-hydroxy hydrocinnamic acid triester with 1 ,3,5-tris(2-hydroxyethyl)-s-triazine- 2,4,6(1 H, 3H, 5H)trione; p-cresol/dicyclopentadiene butylated reaction product and 2,6- bis(2'-bis-hydroxy-3'-t-butyl-5'-methyl-phenyl-4-methyl-phenol). Also known in the art are stabilizers selected from the group consisting of organic phosphites or phosphonites. For example tris (2,4-di-t-butylphenyl) phosphite. The stabilized polyolefins and/or the packaging material may be processed via for example injection moulding, blow moulding, extrusion moulding, compression moulding or thin-walled injection moulding techniques. The obtained products may be applied in a huge amount of applications for example in food packaging applications, biomedical applications, health care applications or pharmaceutical applications.

Moreover, in some case sterilization is required or desired. Sterilization can thereby be achieved for example through a heat treatment and/or by irradiation, especially for example by irradiation with a-radiation (alpha radiation) and/or β-radiation (beta radiation) and/or v- radiation (gamma radiation).

Sterilization may thereby possibly lead to degradation, especially for example to a degradation of some stabilizers, which in turn may influence product properties, especially mechanical properties. Indeed, degradation products obtained after sterilization may have an influence on mechanical properties. In addition, most of the synthetic (poly)phenolic antioxidants used and/or related

degradation products may thereby be regulated by governments because they are suffering from serious limitations. Synthetic antioxidants and/or related degradation products can especially diffuse into the surrounding medium. This can in turn lead to contamination of food and/or other products with potentially toxic or at least concerning substances or byproducts as well as related degradation products. This problem may arise simply because some antioxidants or degradation products or by-products are toxic above a certain level of concentration or are just perceived as concerning. Sterilization may thereby furthermore increase the likelihood of leakage of stabilizers, by-products and/or degradation products.

There is thus a continuous need to provide improved packaging material having no dangerous effects and which also fulfill all requirements related to mechanical properties, processing and/or short term heat stabilization.

The invention is characterized in that sterilized packaging material comprises:

A. a copolymer of ethylene and at least one a-olefin and/or a copolymer of propylene with an a-olefin and/or mixtures of two or more thereof, and - B. between 50 and 200 ppm by weight of a-tocopherol relative to the component

A.

This may especially for example allow to reduce the leak of phosphate(s) and/or di-tert- butyl-phenol and/or 7,9-di-tert-butyl-1 -oxaspiro[4.5]deca-6,9-diene-2,8-dione from sterilized, especially irradiated material. This may for example improve organoleptic properties.

The risk related to and/or the amount of compound(s) possibly migrating out of the packaging material may thereby be reduced. Furthermore the sterilizable packaging material may show improved processing stability.

The sterilizable packaging material is efficiently stabilized, while limiting and/or avoiding the use of toxic substances. This may especially for example allow to improve processing stability, especially for example by reducing cross-linking or chain scission during sterilization and/or (multiple) extrusion(s). Component A may be for example a polyethylene, especially for example a copolymer of ethylene with at least one a-olefin, preferably a linear low density polyethylene (LLDPE), a high density polyethylene (HDPE), a low density polyethylene (LDPE) and/or mixtures of two or more thereof. A copolymer of ethylene with at least one α-olefin may thereby preferably be a copolymer comprising ethylene and at least one α-olefin or a copolymer of ethylene and only one a-olefin.

The packaging material according to the invention may comprise component A in an amount of for example between 50 and 100 wt. % preferably between 60 and > 99.5 wt. %, further preferred between 70 and >99.7 wt. %, further preferred between 80 and > 99.8 wt. %, further preferred between 90 and >99.9 wt. % based on the total weight of the material.

The production processes of LDPE, HDPE and LLDPE are summarised in Handbook of Polyethylene by Andrew Peacock (2000; Dekker; ISBN 0824795466), especially for example at pages 43-66. The catalysts used can include for example Ziegler Natta catalysts, Phillips catalysts and single site catalysts. The latter class is a family of different classes of compounds, which comprises metallocene catalysts. A polymer prepared using a Ziegler-Natta catalyst is obtained for example via the interaction of an organometallic compound or hydride of a Group l-lll metal with a derivative of a Group I - I 11 transition metal. An example of a (modified) Ziegler-Natta catalyst may thereby be for example a catalyst based on titanium tetra chloride and the organometallic compound

triethylaluminium.

With linear low density polyethylene as used herein is meant an ethylene-alpha olefin copolymer comprising ethylene and a C3-C10 alpha-olefin comonomer. Suitable alpha- olefin comonomers include 1 -butene, 1 -hexene, 4-methyl pentene and 1 -octene. The preferred comonomer may be 1 -hexene or 1 -butene. Preferably, the alpha-olefin comonomer is present in an amount of for example from about 2.5 to 30 percent by weight of the ethylene-alpha olefin copolymer, preferably from 5 to about 20 percent by weight of the ethylene-alpha olefin copolymer, more preferably an amount of from about 7 to about 15 percent by weight of the ethylene-alpha olefin copolymer.

Linear low density polyethylene used herein may thereby for example comprise between 3 and 200 CH₃ per 1000 carbon atoms, preferably between 4 and 100 CH₃ per 1000 carbon atoms, preferably between 5 and 40 CH₃ per 1000 carbon atoms, preferably between 10 and 30 CH₃ per 1000 carbon atoms, further prefer between 15 and 25 CH₃ per 1000 carbon atoms, as determined by NMR.

The technologies suitable for the LLDPE manufacture include but are not limited to gas- phase fluidized-bed polymerization, polymerization in solution, and slurry polymerization. According to a preferred embodiment of the present invention the LLDPE has been obtained by gas phase polymerization in the presence of a Ziegler-Natta catalyst. According to another preferred embodiment, the LLDPE may be obtained by gas phase polymerization in the presence of a metallocene catalyst. A polyethylene and/or copolymer of ethylene and at least one a-olefin may for example have a density as determined according to ISO 1 183-1 (2012), method A of ≥ 850 kg/m³ and < 950 kg/m³, preferably≥ 910 kg/m³ and < 940 kg/m³, further preferred between 913 kg/m³ and 923 kg/m³. This may lead to mechanical properties suitable for the use for film applications.

A polyethylene and/or a copolymer of ethylene and at least one a-olefin may for example have an MFI represented by the corresponding melt mass flow rate (MFR) as measured according to ISO 1 131 -1 (201 1 ) at 190°C and at a load of 2.16 kg of between 0.1 dg/min and 10 dg/min, preferably between 0.5 dg/min and 6 dg/min, further preferred between 0.5 dg/min and 4 dg/min, even further preferred between >0.5 dg/min and 3.5 dg/min or between >0.5 dg/min and < 2 dg/min. This may lead to a processability suitable for the use for film applications.

Component B may be α-tocopherol. Component B may be added for example as a liquid and/or using a master batch comprising between 0.5 w.-% and 5 w.-%, preferably between 1 and 5 w.-% of α-tocopherol and/or between 5 and 40 w.-%, preferably between 5 and 15 w.-%, of a organometallic stearate as component C and the rest of the master batch up to 100 w.-% being a further polyethylene as component D, preferably low density

polyethylene.

According to the invention the α-tocopherol may be preferably synthetic α-tocopherol. This allows a good control over wat is actually added.

A suitable example of α-tocopherol and/or synthetic α-tocopherol according to the invention may be Irganox E 201 (supplied by BASF) which is a racemic mixture of equal amounts of all eight possible stereoisomers of α-tocopherol (RRR, SSS, RRS, RSR, SSR, SRS, SRR, RSS) and is referred to as D,L-a-tocopherol or all-rac-alpha-tocopherol.

The use of a-tocopherol may for example allow to achieve efficient stabilization with relatively low loadings of a-tocopherol.

The sterilizable packaging material may preferably not comprise other tocopherols and/or no tocotrienol and/or preferably comprise no natural vitamin E and/or no other antioxidant and/or no other compound comprising at least one phenolic motif. This may allow an efficient stabilization of the packaging material, while reducing the risk associated with and/or the amount of compounds that may migrate out of the packaging material. This may thus reduce possible health hazards.

The amount of component B ranges between 25 ppm and 300 ppm by weight, preferably between 50 ppm and 200 ppm by weight, further preferred between > 50 ppm and <180 ppm by weight, further preferred between > 75 ppm and <175 ppm, further preferred between > 90 ppm and 170 or <170 ppm relative to the component A. In addition or alternatively, the copolymer of ethylene and at least one a-olefin and/or a copolymer of propylene with an α-olefin and/or mixtures of two or more thereof of the packaging material according to the invention is/are produced using one Ziegler-Natta catalyst.

This may allow an efficient stabilization of the packaging material composition, while reducing the risk associated with and/or the amount of compounds that may migrate out of the packaging material composition. This may thus reduce possible health hazards. Besides components A and B, the sterilizable packaging material according to the invention may also comprise component C, which may be at least one acid scavenger , preferably at least one organometallic stearate such as for example magnesium stearate, aluminum stearate, sodium stearate and calcium stearate and/or at least one inorganic hydrotalcites, such as for example DHT4A , preferably calcium stearate. This may further contribute to improve processability.

The amount of optional component C may range between 100 ppm and 1000 ppm by weight, more preferably between 200 ppm and 800 ppm by weight, further preferred between 400 ppm and 600 ppm by weight, relative to the component A. The weight ratio B:C may range for example between 0.05:1 and 0.6:1 , preferably 0.07:1 to 0.5:1 , further preferred between 0.1 :1 and 0.4:1 .

Besides components A, B and C, the sterilizable packaging material according to the invention may also comprise component D, which may be at least one further polyethylene, preferably a low density polyethylene or a polypropylene. The amount of compound D may be between 0 and 10 000 ppm, preferably between 2000 and 7000 ppm. Preferably, the further polyethylene may be different from component A and/or may especially be for example LDPE.

The packaging material according to the invention may thereby for example have an extractable amount (in mg of compounds per kg of packaging material) measured by PTV- GC-MS in a NIAS study (as explained below) of 2,6-di-tert-butylbenzoquinone preferably below 0.8 mg/kg, preferably below 0.5 mg/kg, and/or of 7,9-di-tert-butyl-1 - oxaspiro[4.5]deca-6,9-diene-2,8-dione below 0.4 mg/kg, preferably below 0.2 mg/kg, and/or methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate below 0.5 mg/kg and/or of 2,4 di-tert- butyl-phenol below 10 mg/kg, preferably below 1 mg/kg, further preferred below 0.5 mg/kg, and/or an extractable amount measured by LC-MS in a NIAS study (as explained below) of phosphate below 5 mg/kg, preferably below 1 mg/kg. The substances above may thereby be undesired. Phosphate as used herein may thereby especially for example refer to tris(2,4-di-tert-butylphenyl)phosphate.

The analytic methods used for the NIAS study are described in the following (results reported in mg of compounds per kg of packaging material).

Volatiles were analyzed by TD-GC-MS, which couples thermal desorption (TD), gas chromatography (GC) and mass spectroscopy (MS).

A thermal desorption unit Markes TD100 was thereby used together with a GC Agilent 7890A and Agilent 5975C Mass detector, further using ChemStation E.02.02.1431 software and a column Agilent HP-ULTRA 2 50m^*0.320mm, 0.52 μηι film.

The following temperature program was used: initial temperature of 40 °C, hold for 2 min, ramp 3 ^<C/min until 92 ^<C, ramp 5°C/min until 160 ^<C, ramp 10°C/min until 280°C, hold for 10 min. Detection range was 29 - 450 AMU. Thermal desorption was performed for 40 minutes at 1 10 ^°C. The sample was weighed in empty thermal desorption tubes. Calculations were performed against an external standard of toluene. Semi-volatiles were analyzed by PTV-GC-MS, which couples programmed temperature vaporization (PTV), GC and MS.

A GC Agilent 6890N was thereby used with a Agilent 5973 mass detector and an autosampler Agilent G2614, whereby further using ChemStation E.02.02.1431 software and an Agilent HP5MS 60M^*0.250mm Column, 1.0 μηι film .20 μΙ were thereby injected at 50^° C.

The following temperature program was used: initial temperature of 70 °C, hold for 0.5 min, ramp 10^<C/min until 300 ^<C, hold for 45 min. Detection range in MS was 30 - 500 AMU.

5 grams of cryogenically grounded pellets of each material were extracted with 200 ml_ dichloromethane using 8 hours boiling under reflux conditions. The extracts were concentrated by evaporating the solvent to 1 ml. The dichloromethane extracts were injected without further treatment. Calculations were performed against an external standard of naphthalene.

Non-volatiles were analyzed by LC-MS, which couples liquid chromatography (LC) and MS. A liquid chromatography unit LC Waters Acquity H Class was thereby used together with a Waters SQ Detector 2 detector and MassLynx V4.1 software as well as

Column Waters Acquity UPLC BEH Phenyl, 2.1 x 100mm, 1 .7 μηι film. The column temperature was 40°C and 5 μΙ were injected.

The mobile phase comprised 0.1 % formic acid in water (A), methanol (B) and isopropanol (C) with a gradient from 20% A, 70% B and 10% C to 90% B and 10% C within 6 min and a hold for 1 min. The flow was set to 0.4 ml/min.

The MS-screening was performed for the range of m/z 100-2000 with atmospheric pressure chemical ionization (APCI) in positive/negative mode.

5 grams of cryogenically grounded pellets were extracted with 200 ml_ dichloromethane using 8 hours boiling under reflux conditions. The extracts were concentrated by evaporating the solvent to dryness and dissolving in 1 ml 80/20 2-propanol/water. The dichloromethane extracts were evaporated and dissolved in isopropanol/water (80/20). The target components were quantitated using external standards of each component. The methods used for the migration study are described in the following (results are reported in mg of compounds per kg of food).

Complete migration calculation:

6 dm^2* density polyethylene ^* thickness of film ^* additive concentration = migration into 1 kg food

Migration of additives was validated using the Migratest EXP2013 software (Fabes) based on generally recognised migration models as permitted in the latest version of the Plastics Directive (2002/72/EC, as amended). The migration from packaging was thereby calculated for 10 days contact with fatty food at 60 'C (only diffusion in the packaging determines migration, no partitioning limitation).

The packaging material according to the invention may thereby have an amount of compound migrating based on a migration study applying the modelling software Migratest EXP2013 (Fabes) and/or a complete migration calculation (as described above) of < 1 mg/kg (in mg of compounds per kg of food).

A sterilized packaging material according to the invention may preferably for example comprise and/or consist of:

A. a copolymer of ethylene and at least one a-olefin and/or a copolymer of propylene with an a-olefin and/or mixtures of two or more thereof, and

B. between 50 and 200 ppm by weight of a-tocopherol relative to the component A. and

- C. between 100 ppm and 1000 ppm by weight of an acid scavenger, for example a organometallic stearate, preferably calcium stearate, relative to the component A,

D. optionally a further polyethylene.

That the sterilizable packaging material consists of the components listed above may thereby preferably mean that no other antioxidant and/or no other acid scavenger and/or no other acid scavenger and/or no other organometallic stearate or hydrotalcite and/or no other compound/component is present. The sterilizable packaging material according to the invention may be used in the production of specific packaging articles. Examples of preferred articles are films and/or pouches, especially for applications such as food and/or beverage packaging applications, for health care applications and/or pharmaceutical applications and/or medical or biomedical applications, whereby the packaging material according to the invention is sterilized.

The present invention also concerns the use of a sterilizable packaging material according to the invention may be used in the production of specific articles. Examples of preferred articles are films and/or pouches, especially for applications such as food and/or beverage packaging applications, for health care applications and/or

pharmaceutical applications and/or medical or biomedical applications, whereby the packaging material according to the invention is sterilized.

The sterilizable packaging material according to the invention may for example be part of a multi-layer structure, especially for example a multi-layer structure that comprises at least one aluminum layer, preferably at least one aluminum intermediate layer, and/or at least one PET layer, preferably at least one PET outer layer, and/or a at least one inner layer of the packaging material according to the invention.

The packaging material according to the invention may especially be used in so called blow-fill-seal applications and processes. Blow-fill-seal applications and processes may thereby be applications and processes, used for example in the pharmaceutical industry, where a container is formed, filled, preferably for example with a liquid, and sealed in one process, which preferably does require a little human interaction as possible and/or is carried out inside a machine and/or in a sterile enclosed environment. This may improve antiseptic processing. The packaging material according to the invention may for example be part of a multi-layer structure, especially for example a multi-layer structure that comprises at least one PET layer, preferably at least one PET outer layer, and/or a at least one inner layer of the packaging material according to the invention. Such a multilayer structure may be used for example as lid film for trays, especially for example for food trays. Sterilizable in the sense present invention may thereby especially mean that it can for example be subjected to sterilisation by a γ-radiation (gamma radiation) of for example 20 kilogray, preferably 25 kilogray, further preferred 35 kilogray (kGy). Sterilizable may however also be used herein as synonymous of and interchangeably with (actually) sterilized, especially for example by a γ-radiation (gamma radiation) of for example 20 kilogray, preferably 25 kilogray, further preferred 35 kilogray (kGy). The packaging material and/or sterilisable packaging material according to the invention may thus preferably be a sterilized packaging material.

Each of the and/or all of the tensile modulus MD 1 % secant ( in MPa) measured according to ASTM D882 and/or the impact resistance F max (N) measured according to ISO 7765-2 and/or the haze (%) measured according to ASTM D1003 of the sterilizable packaging material according to the invention, does not vary by more than 50 %, preferably more than 25 %, further preferred by more than 20 %, further preferred by more than 10 %, further preferred by more than 5 %, when blown films with film thickness 25 and/or 125 micron are subjected to sterilization by a γ-radiation (gamma radiation) with a dose of 20 kilogray, preferably 25 kilogray, further preferred

35 kilogray (kGy) compared to samples not subjected to such sterilization.

The sterilized packaging material according to the invention may be so, that the Mw/Mn of the linear low density polyethylene is between 4 and 12, preferably between 4.5 and 1 1 , further preferred between 4.7 and 10, further preferred between 5 and 8, further preferred between > 5 and < 7, further preferred between > 5.5 and < 6.5 and/or the Mz/Mw of the linear low density polyethylene between 4 and 12, preferably between 4.5 and 1 1 , further preferred between 4.7 and 10, further preferred between 5 and 8, further preferred between > 5 and < 7, further preferred between > 5.8 and < 6.8.

The sterilized packaging material according to the invention may be so, that the linear low density polyethylene has a density of≥ 850 kg/m³ and < 950 kg/m³, preferably≥ 910 kg/m³ and < 940 kg/m³, further preferred between 913 kg/m³ and 923 kg/m³, further preferred between > 915 kg/m³ and < 921 and/or a melt mass flow rate (MFR) as measured according to ISO 1 131 -1 (201 1 ) at 190°C and at a load of 2.16 kg of between 0.1 dg/min and 12 dg/min, preferably between 1 dg/min and 1 1 dg/min, further preferred between 3 dg/min and 10 dg/min, even further preferred 4 dg/min and 9 dg/min, even further preferred > 4 dg/min and < 9 dg/min.

The sterilized packaging material according to the invention may be so, that the packaging material does not comprise other tocopherols and/or comprises no tocotrienol and/or no natural vitamin E and/or no other antioxidant and/or no other compound comprising at least one phenolic motif and/or wherein the packaging material comprises only a-tocopherol as antioxidant. The invention also concerns a sterilized packaging

comprising a multi-layer structure that comprise at least one aluminum intermediate layer and/or at least PET outer layer, and/or a at least one inner layer of the packaging material according to invention. The invention further concerns a sterilized packaging, whereby

the multi-layer structure is a lid or pouch for food and/or beverage packaging, especially for food trays, and/or as lid or pouch for a packaging for a medicine, an implant, a patch or another item for medical or biomedical use. Example

Blown Films of 25 and 125 μηι and BUR=2 have been produced on a Kuhne blown film line with 35 kg/h (die size 120 mm, die gap 2,7 mm) with the sterilizable

packaging material according to the invention.

Blown films with film thickness 25 and 125 micron were subjected to

gamma radiation. Chosen setting was gamma radiation with doses of 35 kGy.

Dosimeters were added to the samples to ensure that the requested dose was applied.

For gamma radiation which has a high penetration depth, the polymer was packaged in transparent bags without particular handling.

Irradiation may take several hours. The gamma rays may result from the decay of the radioactive isotope Cobalt-60 (⁶⁰Co). They have a high penetration depth and can penetrate complete pallets or lots. A conveyor system transports around the source rack which houses the radiation sources. Controls ensure that the total gamma irradiation dose that has been fixed for each product is adhered to. Sterilized packaging material according to the invention may (after sterilization) thereby displayed an extractable amount (in mg of compounds per kg of packaging material) measured by PTV-GC-MS in a NIAS study (as explained herein) of 2,6-di-tert- butylbenzoquinone preferably below 0.8 mg/kg, preferably below 0.5 mg/kg, and/or of 7,9- di-tert-butyl-1 -oxaspiro[4.5]deca-6,9-diene-2,8-dione below 0.4 mg/kg, preferably below 0.2 mg/kg, and/or methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate below 0.5 mg/kg and/or of 2,4 di-tert-butyl-phenol below 10 mg/kg, preferably below 1 mg/kg, further preferred below 0.5 mg/kg, and/or an extractable amount measured by LC-MS in a NIAS study (as explained herein) of phosphate below 5 mg/kg, preferably below 1 mg/kg.

Claims

Sterilized packaging material comprising

- A. a copolymer of ethylene and at least one α-olefin and/or a copolymer of

propylene with an α-olefin and/or mixtures of two or more thereof, and

B. between 50 and 200 ppm by weight of a-tocopherol relative to the component A.

Sterilized packaging material according to Claims 1 , wherein the composition further comprises:

C. an acid scavenger, preferably a organometallic stearate.

Sterilized packaging material according to any one of Claims 1 -2, wherein the amount of component B ranges > 50 ppm and <180 ppm by weight, further preferred between > 75 ppm and <175 ppm, further preferred between > 90 ppm and 170 or <170 ppm relative to the component A and/or the copolymer of ethylene and at least one α-olefin and/or a copolymer of propylene with an α-olefin and/or mixtures of two or more thereof is/are produced using one Ziegler-Natta catalyst. 4. Sterilized packaging material according to any one of Claims 2-3, wherein the

amount of component C ranges between 100 ppm and 1000 ppm by weight relative to the component A.

5. Sterilized packaging material according to any one of Claims 1 -4 wherein the

amount of component A is between 50 and <100 wt. % preferably between 60 and >

99.5 wt. %, further preferred between 70 and >99.7 wt. %, further preferred between 80 and > 99.8 wt. %, further preferred between 90 and >99.9 wt. % based on the total weight of the material. 6. Sterilized packaging material according to any one of Claims 1 -5, wherein the

Mw/Mn of the linear low density polyethylene is between 4 and 12, preferably between 4.5 and 1 1 , further preferred between 4.7 and 10, further preferred between 5 and 8, further preferred between > 5 and < 7, further preferred between > 5.5 and < 6.5 and/or the Mz/Mw of the linear low density polyethylene between 4 and 12, preferably between 4.5 and 1 1 , further preferred between 4.7 and 10, further preferred between 5 and 8, further preferred between > 5 and < 7, further preferred between > 5.8 and < 6.8.

Sterilized packaging material according to any one of Claims 1 -6, wherein the linear low density polyethylene has a density of≥ 850 kg/m³ and < 950 kg/m³, preferably≥ 910 kg/m³ and < 940 kg/m³, further preferred between 913 kg/m³ and 923 kg/m³, further preferred between > 915 kg/m³ and < 921 and/or a melt mass flow rate (MFR) as measured according to ISO 1 131 -1 (201 1 ) at 190 ^<C and at a load of 2.16 kg of between 0.1 dg/min and 12 dg/min, preferably between 1 dg/min and 1 1 dg/min, further preferred between 3 dg/min and 10 dg/min, even further preferred 4 dg/min and 9 dg/min, even further preferred > 4 dg/min and < 9 dg/min.

Sterilized packaging material according to any one of Claims 1 -7, wherein the packaging material does not comprise other tocopherols and/or comprises no tocotrienol and/or no natural vitamin E and/or no other antioxidant and/or no other compound comprising at least one phenolic motif and/or wherein the packaging material comprises only a-tocopherol as antioxidant.

Sterilized packaging material according to any one of Claims 1 -8, wherein the packaging material comprises LLDPE as component A in an amount between 50 and <100 wt- % of the packaging material, whereby the LLDPE comprises between 3 and 200 CH₃ per 1000 carbon atoms, preferably between 4 and 100 CH₃ per 1000 carbon atoms, preferably between 5 and 40 CH₃ per 1000 carbon atoms, preferably between 10 and 30 CH₃ per 1000 carbon atoms, further prefer between 15 and 25 CH₃ per 1000 carbon atoms, as measured by NMR.

Sterilized packaging material according to any one of Claims 1 -9, wherein each of the and/or all of the tensile modulus MD 1 % secant ( in MPa) measured according to ASTM D882 and/or the impact resistance F max (N) measured according to ISO 7765-2 and/or the haze (%) measured according to ASTM D1003 of the sterilizable packaging material according to the invention, does not vary by more than 50 %, preferably more than 25 %, further preferred by more than 20 %, further preferred by more than 10 %, further preferred by more than 5 % when blown films with film thickness 25 and/or 125 micron are subjected to sterilization by a γ-radiation (gamma radiation) with a dose of 20 kilogray, preferably 25 kilogray, further preferred 35 kilogray (kGy) compared to samples not subjected to such sterilization.

1 1 . Sterilized film or pouch comprising the packaging material according to any one of Claims 1 - 10. 12. Use of a sterilized packaging material according to any one of Claims 1 -10

for films and/or pouches for food and/or beverage packaging applications, whereby the packaging material according to the invention is directly in contact with an item intended for human use, such as a beverage or a food item or another item for nutritional use. 13. Use of a sterilized packaging material according to any one of Claims 1 -10

for films and/or pouches for health care applications and/or pharmaceutical applications and/or medical or biomedical applications, whereby the packaging material according to the invention is directly in contact with an item intended for human use, such as a medicine, an implant, a patch or another item for medical or biomedical use.

14. Sterilized packaging

comprising a multi-layer structure that comprise at least one aluminum intermediate layer and/or at least PET outer layer, and/or a at least one inner layer of the packaging material according to any one of claims 1 -10.

15. Sterilized packaging according to claim 14, whereby

the multi-layer structure is a lid or pouch for food and/or beverage packaging, especially for food trays, and/or as lid or pouch for a packaging for a medicine, an implant, a patch or another item for medical or biomedical use.