PET-free package with PP-EVOH multi-layer structure

Abstract

Multilayer film made of a polymeric material comprising a polypropylene homopolymer, a polypropylene copolymer and EVOH in an amount of at least 96 wt%, preferably at least 98 wt%, relative to the polymeric material, said multilayer film comprising at least 6 layers: a base layer (BL) / laminate layer (LL) / tie layer 1 (TL1) / core layer (CL) / tie layer 2 (TL2) / sealant layer (SL) wherein all layers do not contain polyethylene terephthalate (PET).

Description

TECHNICAL FIELD

[0001] The present invention relates to a multilayer film structure and packaging for food packaging, in particular food packaging comprising a lid and a tray that can be mechanically recycled. The present invention also relates to a mechanically recycled composition based on these structures and packaging. BACKGROUND

[0002] The market for food products for mass retail, such as supermarket chains, requires advanced packaging and packaging materials, most importantly to improve the shelf life of these food products and the aesthetic qualities of the packaging, such as the transparency of the container. A technical requirement for the market of food retail is to have a packaging available formed by a tray or container and by a top film or lidding, which provides a proper barrier to prevent oxygen from entering the tray, thus preserving the quality of the product contained therein. The known packaging commonly used on the market comprises a polyethylene terephthalate (PET) carrier (single or triple layer) on which a three-layer laminated film PE / EVOH / PE is applied. This type of packaging system is commonly known as modified atmosphere packaging system (MAP). The PET carrier is almost impossible to recycle in any polyolefin stream, while the barrier film laminate (PE / EVOH / PE) makes the recycling in the PET stream difficult and expensive. There is an urgent need for a packaging made of compatible polymers, so as to obtain a composition with reasonable mechanical properties by means of simple shredding and re-extrusion of mixed plastics. Since the state of the art describes high gas permeability, there is an urgent need to provide a multilayer film with low water vapor transmission rate and low oxygen transmission rate. US2022081523A1 describes a high gas permeable film comprising an ethylene-vinyl alcohol copolymer (A), a polyolefin (B) and an acid-modified ethylene-a-olefin copolymer (C), in some embodiments the mass ratio A / (B+C) of the ethylene-vinyl alcohol copolymer (A) to the total amount of unmodified polyolefin (B) and acid-modified ethylene-a-olefin copolymer (C) is 78 / 22-62 / 38.

[0003] EP1059163A2 describes a multilayer structure in which an A layer made of ethylene-vinyl alcohol copolymer resin (A) and a C layer made of polypropylene (C) are laminated by a B layer made of adhesive resin (B). EP1059163A2 teaches to perform a biaxial stretching by a factor of 4-10 in the longitudinal direction and 5-12 in the transverse direction. It is known that this biaxially oriented polypropylene (BOPP) film has better barrier properties than non-oriented films, but also requires complex processing equipment.

[0004] It has been found that by combining a polypropylene support layer with a polypropylene-based multilayer barrier system and EVOH, a packaging system for MAP with the same polymer structure in the tray and lid can be manufactured. The present invention is based on the unexpected finding that this packaging system can be mechanically recycled. SUMMARY

[0005] The present invention relates to a multilayer film made of a polymeric material comprising a content of at least 96 wt%, preferably at least 98 wt% of polypropylene homopolymer, polypropylene copolymer and EVOH, relative to the polymeric material, the multilayer film comprising at least 6 layers:

[0006] a base layer (BL) / a lamination layer (LL) / a tie layer 1 (TL1) / a core layer (CL) / a tie layer 2 (TL2) / a sealing layer (SL),

[0007] wherein all layers are free of polyethylene terephthalate (PET);

[0008] the base layer (BL) comprises polypropylene homopolymer and / or random propylene copolymer;

[0009] the lamination layer (LL) comprises random propylene copolymer;

[0010] the tie layer 1 (TL1) comprises a polar modified polypropylene copolymer, preferably selected from maleic anhydride grafted polypropylene (PP-g-MAH), maleic anhydride grafted polypropylene co-grafted with styrene (PP-g-MAH-coSt), or a combination thereof;

[0011] the core layer (CL) comprises ethylene-vinyl alcohol copolymer (EVOH);

[0012] the tie layer 2 (TL2) comprises a polar modified polypropylene copolymer, preferably selected from maleic anhydride grafted polypropylene (PP-g-MAH), or maleic anhydride grafted polypropylene copolymer co-grafted with styrene (PP-g-MAH-coSt), or a combination thereof;

[0013] the sealing layer (SL) comprises random propylene copolymer; and

[0014] the multilayer film is not biaxially oriented.

[0015] The present invention also relates to a package comprising a tray and a lid made of the multilayer film of any one of claims 1-11 or the package of claim 12 or 13.

[0016] The present invention also relates to a material obtainable by mechanical recycling of the multilayer film of any one of claims 1-11 or the package of claim 12 or 13, preferably having one or more of the following properties:

[0017] - a melt flow rate of 3.0 to 10 g / 10 min (ISO 1133; 2.16 kg; 230 °C);

[0018] - a tensile modulus (ISO 527, injection molded specimen) of 1300 to 2000 MPa;

[0019] - a strain at break (ISO 527, injection molded specimens) of at least 400%, preferably at least 500%, most preferably at least 600%.

[0020] As used herein, the term film is equivalent to sheet. As is commonly understood, "sheet" merely denotes a relatively thick film.

[0021] The multilayer films of the present application are not biaxially oriented. Biaxially oriented polypropylene (BOPP) films are films that are stretched in both the machine direction and the transverse direction, thereby creating molecular chain orientation in both directions. Thus, "not biaxially oriented" encompasses only stretching of the film or sheet in one direction.

[0022] Visbreaking refers to a process in which polypropylene or polypropylene copolymers are extruded with a free radical initiator, typically a peroxide, and conventional additives, such as stabilizers to shorten the polymer chain length by chemical reaction. Polar modified polypropylene generally refers to polypropylene modified by grafting of polar groups, and / or to the introduction of monomers containing polar groups. "Grafted polypropylene" refers to polypropylene having more than one species attached to the backbone in the form of a side chain. A typical example is maleic anhydride grafted polypropylene (PP-g-MAH) or maleic anhydride grafted polypropylene co-grafted with styrene (PP-g-MAH-co-St).

[0023] Packaging refers to packaging articles. Mechanical recycling is defined as shredding and re- extrusion, optionally in the presence of other additives, and optionally further processing steps in the mechanical recycling line. "Recycling" refers to the situation where a material is used for a second time after it has been used for the first time by a private or industrial consumer.

[0024] The multilayer films described herein have a water vapor transmission rate (WVTR, ISO 15106-2:2003, measured at 38°C; 85% relative humidity) of preferably less than 0.30 g / m 2 / day, more preferably less than 0.28 g / m 2 / day.

[0025] In another aspect, the multilayer films described herein have an oxygen transmission rate (OTR, 23°C; 100% O2; 0% RH; pressure differential method) of preferably less than 5.0 cm 3 / m 2 · day · bar, more preferably less than 2.0 cm 3 / m 2 · day · bar, most preferably less than 1.4 cm 3 / m 2 · day · bar, measured according to ISO 15105-1 :2007.

[0026] The polypropylene homopolymer and / or the random propylene copolymer comprised in the base layer (BL) has one or more of the following properties:

[0027] - a melt flow rate MFR2of 1.5 to 15 g / 10 min, preferably 2.0 to 12 g / 10 min (ISO 1133; 2.16 kg; 230 °C);

[0028] - a melting temperature (DSC, ISO 11357) in the range of 150 to 172 °C, preferably in the range of 150 to 158 °C;

[0029] - in case of a copolymer, ethylene is the only comonomer present;

[0030] - less than 0.9 wt% of units derived from ethylene, preferably less than 0.5 wt% of units derived from ethylene;

[0031] - a flexural modulus (ISO 178; measured on injection moulded samples, determined at 23 °C) of at least 1600 MPa, preferably at most 2300 MPa;

[0032] - a content of 2.1 -regio defects of 0.2 mol% or more, preferably 0.35 mol% or more;

[0033] - preferably derived from a single site catalyst;

[0034] - is

[0035] o a blend of a single site catalyst derived polymer and a Ziegler-Natta derived polymer,

[0036] o more preferably a blend of a single site catalyst derived polymer and a Ziegler-Natta derived polymer containing a polymeric nucleating agent,

[0037] o even more preferably a blend obtained by blending 97.0 to 99.0 wt% of a single site catalyst derived polymer with 1.0 to 3.0 wt% of a Ziegler-Natta derived polymer containing a polymeric nucleating agent, wherein the percentages refer to the sum of the blend,

[0038] o most preferably a blend obtained by blending 97.0 to 99.0 wt% of a single site catalyst derived polymer with 1.0 to 3.0

[0039] wt% of a Ziegler-Natta derived polymer containing a polyvinylcyclohexane, wherein the percentages refer to the sum of the blend;

[0040] - a xylene cold soluble fraction (analysed according to ISO 16152) of less than 0.5 wt%;

[0041] - greater than 97.0 wt.-% relative to the base layer (BL).

[0042] Preferably, the polypropylene in the base layer (BL) is a homopolymer. Alternatively, a random propylene copolymer with a very low amount of ethylene, for example less than 0.9 wt.-% or less than 0.5 wt.-%, can be used, but is less preferred. Such random propylene copolymers are often referred to as mini-random.

[0043] The preferred melting temperature is in the range of 150 to 172 °C, more preferably in the range of 150 to 158 °C. Generally, by using a single-site catalyst, a range of 150 to 158 °C can be achieved. In contrast, by using a Ziegler-Natta catalyst, a range of 160 to 170 °C can be achieved.

[0044] When the polypropylene is produced under suitable conditions by using a single-site catalyst, the content of 2.1 -regio defects can preferably be 0.2 mol-% or more, more preferably 0.35 mol-% or more, generally with an upper limit of 1.0 mol-%. The degree of 2.1 -regio defects can be influenced by the polymerization temperature.

[0045] The xylene cold soluble fraction (analyzed according to ISO 16152) is preferably less than 0.50 wt.-%; more preferably less than 0.40 wt.-%.

[0046] All features described above in relation to the homopolymer and / or the random propylene copolymer shall also apply to the blend, in particular to a blend of a single-site catalyst derived polymer and a Ziegler-Natta derived polymer as described above. This means that the blend comprised in the base layer (BL) of the multilayer film has one or more of the following properties:

[0047] - the blend is a mixture of a homopolymer and / or a random propylene copolymer;

[0048] - the blend has a melt flow rate MFR2 of 1.5 to 15 g / 10 min, preferably 2.0 to 12 g / 10 min (ISO 1133; 2.16 kg; 230 °C);

[0049] - the blend has a melting temperature (DSC, ISO 11357) in the range of 150 to 172 °C, preferably in the range of 150 to 158 °C;

[0050] - in case of a copolymer, ethylene is the only comonomer present in the blend;

[0051] - the blend has less than 0.9 wt.-% of units derived from ethylene, preferably less than 0.2 wt.-% of units derived from ethylene;

[0052] - the blend has a flexural modulus (ISO 178; measured on injection moulded samples, determined at 23 °C) of at least 1600 MPa, preferably at most 2300 MPa;

[0053] - the blend has a content of 2.1 -regio defects of 0.2 mol% or more, preferably 0.35 mol% or more, most preferably at most 1.0 mol%.

[0054] - the blend is preferably a mixture of a single-site catalyst derived polymer and a Ziegler-Natta derived polymer, preferably the blend is a mixture of a single-site catalyst derived polymer and a Ziegler-Natta derived polymer containing a polymer nucleating agent, even more preferably the blend is obtained by blending 97.0 to 99.0 wt% of a single-site catalyst derived polymer with 1.0 to 3.0 wt% of a Ziegler-Natta derived polymer containing a polymer nucleating agent, wherein the percentages refer to the total of the blend, most preferably the blend is obtained by mixing 97.0 to 99.0 wt% of a single-site catalyst derived polymer with 1.0 to 3.0 wt% of a Ziegler-Natta derived polymer containing polyvinylcyclohexane, wherein the percentages refer to the total of the blend;

[0055] - the blend has a xylene cold soluble fraction (analysed according to ISO 16152) of less than 0.5 wt%;

[0056] - the blend has a content of more than 97.0 wt% relative to the base layer (BL).

[0057] The random propylene copolymer comprised in the lamination layer (LL) and / or the sealing layer (SL) has one or more of the following properties:

[0058] - a melt flow rate MFR2 of 5.0 to 15 g / 10min (ISO 1133; 2.16 kg; 190 °C);

[0059] - ethylene is the only comonomer present;

[0060] - an ethylene content of 1.0 to 6.0 wt%, preferably 1.0 to 3.0 wt%;

[0061] - a melting temperature (DSC, ISO 11357) in the range of 122 to 145 °C, preferably in the range of 123 to 136 °C;

[0062] - a content of 2.1 -regio defects of 0.2 mol% or more, preferably 0.35 mol% or more;

[0063] - derived from a Ziegler-Natta catalyst free of phthalate esters or preferably derived from a single-site catalyst;

[0064] - a xylene cold soluble fraction (analysed according to ISO 16152) of less than 1.0 wt%, preferably less than 0.8 wt%;

[0065] - a flexural modulus (ISO 178; measured on injection moulded samples, determined at 23 °C) of at least 600 MPa, preferably at least 800 MPa;

[0066] - vis-broken;

[0067] - a content of more than 97.0 wt% with respect to the lamination layer (LL) or sealing layer (SL), respectively.

[0068] The preferred melting temperature (DSC, ISO 11357) falls in the range of 122 to 145 °C, more preferably 123 to 136 °C. By using a single site catalyst a melting temperature of 123 to 136 °C can be achieved.

[0069] 2.1 - The content of regio-defects is preferably more than 0.2 mol%, more preferably more than 0.35 mol%, with an upper limit of typically 1.0 mol%. The use of a single site catalyst introduces 2.1 regio-inversion, wherein the amount of 2.1 regio-inversion can be varied by polymerization temperature variation. In an alternative embodiment, the random propylene copolymer comprised in the lamination layer (LL) and / or sealing layer (SL) can be derived from a Ziegler-Natta catalyst free of phthalate esters.

[0070] The xylene cold soluble fraction (analysed according to ISO 16152) is preferably less than 1.0 wt%, more preferably less than 0.8 wt%. The flexural modulus (ISO 178; measured on injection moulded samples, determined at 23 °C) is preferably at least 600 MPa, more preferably at least 800 MPa.

[0071] The random propylene copolymer comprised in the lamination layer (LL) and / or sealing layer (SL) can be vis-broken. Vis-breaking can directly adjust the melt flow rate.

[0072] The content of random propylene copolymer is preferably more than 97.0 wt% with respect to the lamination layer (LL) or sealing layer (SL), respectively.

[0073] The multilayer film according to the present application is preferably characterized in that the lamination layer (LL) and sealing layer (SL) comprise the same random propylene copolymer.

[0074] The ethylene-vinyl alcohol copolymer (EVOH) forming the core layer (CL) has one or more of the following properties:

[0075] - a density (ISO 1183) of 1190 to 1230 kg / m 3 ;

[0076] - a melt flow rate MFR2 of 0.5 to 5.0 g / 10 min (ISO 1133; 2.16 kg; 190 °C);

[0077] - a melting temperature (DSC; ISO 11357) of 175 °C or more, preferably up to 190 °C.

[0078] Such ethylene-vinyl alcohol copolymers (EVOH) are commercially available, for example, from Kuraray Co., Ltd.

[0079] The core layer (CL) based on ethylene-vinyl alcohol copolymer (EVOH) is encapsulated by two tie layers (TL1, TL2). These tie layers (TL1, TL2) are preferably made of maleic anhydride grafted polypropylene (PP-g-MAH) or maleic anhydride grafted polypropylene co-grafted with styrene (PP-g-MAH-coSt). The maleic anhydride grafted polypropylene co-grafted with styrene (PP-g-MAH-coSt) is a standard material, commercially available from producers in this technical field.

[0080] Preferably, the material of the tie layer 1 (TL1) is the same as the material of the tie layer 2 (TL2).

[0081] Preferably, the polar modified polypropylene copolymer comprised in the tie layer 2 (TL2) has one or more of the following properties:

[0082] - is maleic anhydride grafted polypropylene (PP-g-MAH), optionally maleic anhydride grafted polypropylene comprising co-grafted styrene (PP-g-MAH-coSt);

[0083] - a melt flow rate of 7.0 to 100.0 g / 10 min (ISO 1133; 5 kg; 190 °C);

[0084] - a density (ISO 1183) of 870 to 900 kg / m 3 ;

[0085] - a melting temperature (ASTM D3418) in the range of 135 °C to 155 °C;

[0086] - is the same as the material of the tie layer 1 (TL1).

[0087] Preferably, the layer thicknesses of the multilayer film according to the present application are as follows:

[0088] - the base layer (BL) is 50 to 350 pm, preferably 70 to 300 pm; and / or

[0089] - the lamination layer (LL) is 5 to 50 pm, preferably 7 to 35 pm; and / or

[0090] - the tie layer 1 (TL1) is 1 to 7 pm, preferably 1 to 4 pm; and / or

[0091] - the core layer (CL) is 3 to 15 pm, preferably 4 to 12 pm; and / or

[0092] - the tie layer 2 (TL2) is 1 to 7 pm, preferably 1 to 4 pm; and / or

[0093] - the sealing layer (SL) is 5 to 50 pm, preferably 7 to 35 pm.

[0094] More preferably, the layer thicknesses of the multilayer film according to the present application are as follows:

[0095] - the base layer (BL) is 70 to 300 pm; and

[0096] - the lamination layer (LL) is 7 to 35 pm; and

[0097] - the tie layer 1 (TL1) is 1 to 4 pm; and

[0098] - the core layer (CL) is 4 to 12 pm; and

[0099] - the tie layer 2 (TL2) is 1 to 4 pm, and

[0100] - the sealing layer (SL) is 7 to 35 pm.

[0101] Further preferably, the total thickness of the multilayer film is 70 to 440 pm, preferably 90 to 390 pm, for example 100 to 250 pm.

[0102] The multilayer film of the present application can preferably be obtained by the following steps:

[0103] (a) preparing a cast film by extruding a base layer polypropylene homopolymer and / or random propylene copolymer;

[0104] (b) co-extruding a barrier cast film comprising a lamination layer, a tie layer 1, a core layer, a tie layer 2 and a sealing layer (LL / TL1 / CL / TL2 / SL); and

[0105] (c) pressing the cast film prepared in step a) with the barrier cast film prepared in step b) at a temperature in the range of 120 to 130 °C.

[0106] In yet another aspect, the present application relates to a package comprising a tray and a lid made of the multilayer film described herein. All preferred aspects with regard to the multilayer film shall also apply to the package.

[0107] With respect to the packaging, the packaging according to the present application comprises polypropylene, polypropylene copolymer and EVOH in an amount of at least 96 wt%, preferably at least 98 wt%. This does not include a large amount of other materials, such as undesired PET.

[0108] In yet another aspect, the present application relates to a material obtainable by mechanical recycling of the multilayer film described herein or the packaging described herein, said material preferably having one or more of the following properties:

[0109] - a melt flow rate of 3.0 to 10 g / 10 min (ISO 1133; 2.16 kg; 230 °C);

[0110] - a tensile modulus (ISO 527, injection molded specimen) of 1300 to 2000 MPa;

[0111] - a strain at break (ISO 527, injection molded specimen) of at least 400%, preferably at least 500%, most preferably at least 600%.

[0112] The material according to the present application preferably has one or more of the following properties:

[0113] - a melt flow rate of 3.0 to 10 g / 10 min (ISO 1133; 2.16 kg; 230 °C);

[0114] - a strain at break (ISO 527, injection molded specimen) of at least 700%.

[0115] A strain at break (ISO 527, injection molded specimen) of at least 700% can easily be achieved when the base layer (BL) comprises a polypropylene homo- and / or random propylene copolymer derived from a single-site catalyst.

[0116] In the following, a preparation method is described for:

[0117] - a polypropylene homo- and / or random propylene copolymer comprised in the base layer (BL), and

[0118] - a random propylene copolymer comprised in the lamination layer (LL) and / or the sealing layer (SL).

[0119] Polymerization processes suitable for the preparation of random copolymers generally comprise at least two polymerization stages, and each stage can be carried out in solution, slurry, fluidized bed, bulk, or gas phase.

[0120] The term "polymerization reactor" means where the main polymerization takes place. Thus, in case the process consists of one or two polymerization reactors, the definition does not exclude the option that the whole system comprises a prepolymerization step, for example in a prepolymerization reactor. The term "consists of is a closed expression only for the main polymerization reactors.

[0121] The term "sequential polymerization process" refers to the preparation of a C2C3 random copolymer (A) or a propylene homopolymer in at least two reactors in series. Thus, such a polymerization system comprises at least a first polymerization reactor (R1) and a second polymerization reactor (R2) and optionally a third polymerization reactor (R3).

[0122] The first polymerization reactor (R1) is preferably a slurry reactor and can be any continuous or simply agitated batch tank reactor or loop reactor operated in bulk or slurry. Bulk means polymerization in a reaction medium comprising at least 60% (w / w) of monomers. According to the present application, the slurry reactor is preferably a (bulk) loop reactor.

[0123] The second polymerization reactor (R2) and optionally the third polymerization reactor (R3) are preferably gas phase reactors (GPR), i.e. a first gas phase reactor (GPR1) and a second gas phase reactor (GPR2). The gas phase reactor (GPR) according to the present application is preferably a fluidized bed reactor, a fast fluidized bed reactor or a settled bed reactor or any combination thereof.

[0124] A preferred multistage process is a "loop-gas phase" process, for example the BORSTAR® process developed by Borealis (referred to as the BORSTAR® technology), for example described in the patent literature, such as in EP 0 887 379, WO 92 / 12182, WO 2004 / 000899, WO 2004 / 111095, WO 99 / 24478, WO 99 / 24479 or WO 00 / 68315. The BORSTAR® technology, for example described in the patent literature, such as in EP 0 887 379, WO 92 / 12182, WO 2004 / 000899, WO 2004 / 111095, WO 99 / 24478, WO 99 / 24479 or WO 00 / 68315.

[0125] Another suitable slurry-gas phase process is the Unipol® process of Marl.

[0126] Preferably, in the inventive process for the preparation of a C2C3 random copolymer and / or a propylene homopolymer as defined above, the conditions of the first reactor (R-1) in step (a) (i.e. the slurry reactor (SR), for example a loop reactor (LR)) can be as follows:

[0127] - the temperature is in the range of 40°C to 110°C, preferably in the range of 60°C to 100°C, more preferably in the range of 65 to 95°C;

[0128] - the pressure is in the range of 20 bar to 80 bar, preferably in the range of 40 bar to 70 bar;

[0129] - hydrogen can be added in a manner known per se to control the molar mass.

[0130] Subsequently, the reaction mixture of the first reactor (R-1 ) is transferred to the second reactor (R-2) (i.e. gas phase reactor (GPR-1 )), wherein the conditions are preferably as follows:

[0131] - the temperature is in the range of 50 °C to 130 °C, preferably in the range of 60 °C to 100 °C;

[0132] - the pressure is in the range of 5 bar to 50 bar, preferably in the range of 15 bar to 35 bar;

[0133] - hydrogen can be added in a manner known per se to control the molar mass.

[0134] Preferably, the random copolymer and / or the propylene homopolymer is prepared in the presence of a metallocene catalyst.

[0135] Thus, the random copolymer and / or the propylene homopolymer is prepared by a process comprising the steps of:

[0136] a) polymerizing propylene and ethylene in a first reactor to obtain a polymer fraction (A-1 ) of a random copolymer,

[0137] b) transferring the polymer fraction (A-1 ) and unreacted comonomer from the first reactor into a second reactor (R-2),

[0138] c) feeding propylene and ethylene into the second reactor (R-2),

[0139] d) polymerizing propylene and ethylene in the presence of the polymer fraction (A-1 ) in the second reactor (R-2) to obtain a polymer fraction (A-2).

[0140] The polymer fraction (A-1 ) and the polymer fraction (A-2) form the random copolymer used herein.

[0141] The polymerization is carried out in the presence of a metallocene catalyst comprising: (a) a complex of formula (I):

[0142]

[0143] wherein,

[0144] M is zirconium or hafnium;

[0145] each X is a sigma ligand;

[0146] L is a divalent bridge selected from -R'2C-, -R'2C-CR'2-, -R'2Si-, -R'2Si-SiR'2-, -R'2Ge-, wherein each R' is independently a hydrogen atom, a Ci-C6hydrocarbyl group, a C6-Ci0aryl group, a C7-Ci0aralkyl group, a C7-Ci0alkylaryl group, or a C4-Ci0cycloalkyl group, or two R' groups together form a C2-C6hydrocarbylene group, or a C2-C6haloalkylidene group; 20 - a C6-Ci0aryl group, a C7-Ci0aralkyl group, a C7-Ci0alkylaryl group, or a C4-Ci0cycloalkyl group; 20 - a C6-Ci0aryl group, a C7-Ci0aralkyl group, a C7-Ci0alkylaryl group, or a C4-Ci0cycloalkyl group; 20 - a C6-Ci0aryl group, a C7-Ci0aralkyl group, a C7-Ci0alkylaryl group, or a C4-Ci0cycloalkyl group; 20 - a C6-Ci0aryl group, a C7-Ci0aralkyl group, a C7-Ci0alkylaryl group, or a C4-Ci0cycloalkyl group; 20 - a C6-Ci0aryl group, a C7-Ci0aralkyl group, a C7-Ci0alkylaryl group, or a C4-Ci0cycloalkyl group;

[0147] R 2 and R 2' are each independently a C1-C20hydrocarbyl group optionally containing one or more heteroatoms from Groups 14-16; 20 - a C6-Ci0aryl group, a C7-Ci0aralkyl group, a C7-Ci0alkylaryl group, or a C4-Ci0cycloalkyl group;

[0148] R 5' is a C1-C20hydrocarbyl group optionally containing one or more heteroatoms from Groups 14-16; 1-20 - a C6-Ci0aryl group, a C7-Ci0aralkyl group, a C7-Ci0alkylaryl group, or a C4-Ci0cycloalkyl group;

[0149] R 6 and R 6' are each independently hydrogen or a C1-C20hydrocarbyl group optionally containing one or more heteroatoms from Groups 14-16; 1-20 - a C6-Ci0aryl group, a C7-Ci0aralkyl group, a C7-Ci0alkylaryl group, or a C4-Ci0cycloalkyl group; 6' preferably a tertiary alkyl group;

[0150] R 7 is hydrogen or a C1-C20hydrocarbyl group optionally containing one or more heteroatoms from Groups 14-16; 1-20 - a C6-Ci0aryl group, a C7-Ci0aralkyl group, a C7-Ci0alkylaryl group, or a C4-Ci0cycloalkyl group;

[0151] R 7' is hydrogen;

[0152] Ar is independently an aryl or heteroaryl group having up to 20 carbon atoms optionally substituted with one or more groups R 1 ;

[0153] Ar' is independently an aryl or heteroaryl group having up to 20 carbon atoms optionally substituted with one or more groups R 1 ;

[0154] each R 1 is a C 1-20 hydrocarbyl group, or two R 1 groups on adjacent carbon atoms can together form a fused 5- or 6-membered non-aromatic ring with the Ar group, said ring itself optionally being substituted with one or more R 4 groups;

[0155] each R 4 is a C 1-20 hydrocarbyl group;

[0156] and

[0157] (ii) a co-catalyst comprising at least one or two compounds of a Group 13 metal (e.g. Al and / or boron compounds).

[0158] The catalyst used in the process of the present application is in the form of solid particles. As mentioned above, it can be supported on a conventional support known to the skilled person. Preferably, the catalyst used does not contain an external support.

[0159] Ideally, the catalyst can be obtained by a process wherein,

[0160] (a) forming a liquid / liquid emulsion system comprising a solution of the catalyst components (i) and (ii) dispersed in a solvent to form dispersed droplets; and

[0161] (b) forming solid particles by solidifying said dispersed droplets.

[0162] The term C 1-20 hydrocarbyl groups include C 1-20 alkyl, C 2-20 alkenyl, C 2-20 alkynyl, C 3-20 cycloalkyl, C 3-20 cycloalkenyl, C 6-20 aryl, C 7-20 alkylaryl, or C 7-20 arylalkyl, or of course mixtures of these groups, for example a cycloalkyl group which is substituted by an alkyl group.

[0163] Unless otherwise indicated, preferred C 1-20 hydrocarbyl groups are C 1-20 alkyl, C 4-20 cycloalkyl, C 5-20 cycloalkyl-alkyl, C 7-20 alkylaryl, C 7-20 arylalkyl, or C 6-20 aryl, especially C 1-10 alkyl, C 6-10 aryl, or C 7-12 arylalkyl, for example C 1-8 alkyl. Most preferred hydrocarbyl groups are methyl, ethyl, propyl, isopropyl, t-butyl, isobutyl, C 5-6 cycloalkyl, cyclohexylmethyl, phenyl or benzyl.

[0164] The term halogen includes fluorine, chlorine, bromine and iodine groups, especially chlorine groups, when referring to complex definitions.

[0165] The oxidation state of the metal ion is determined mainly by the nature of the metal ion in question and the stability of the individual oxidation states of each metal ion.

[0166] It will be appreciated that in the complex of the present application the metal ion M is coordinated by the ligands X to satisfy the valency of the metal ion and to fill its available coordination sites. The nature of these σ-ligands can vary greatly.

[0167] Such catalysts are described in WO 2013 / 007650, which is incorporated herein by reference. Thus, the preferred complex used in the present application has the formula (II') or (II):

[0168]

[0169] wherein,

[0170] M is zirconium or hafnium;

[0171] each X is a σ-ligand, preferably each X is independently a hydrogen atom, a halogen atom, a C 1-6 alkoxy group, a C 1-6 alkyl group, a phenyl group or a benzyl group;

[0172] L is a divalent bridge selected from -R'2C-, -R'2C-CR'2-, -R'2Si-, -R'2Si-SiR'2-, -R'2Ge-, wherein each R' is independently a hydrogen atom, a C 1-20 hydrocarbyl group, a C 3-10 cycloalkyl group, a tri(C 1-20- alkyl)silyl group, a C 6-20 aryl group, a C 7-20 arylalkyl group or a C 7-20 alkylaryl group;

[0173] each R 2 or R 2' is a C 1-10 alkyl group;

[0174] R 5' is a C 1-10 alkyl group or a Z'R 3 group;

[0175] R 6 is hydrogen or a C 1-10 alkyl group;

[0176] R 6' is a C 1-10 alkyl group or a C 6-10 aryl group; preferably a tertiary alkyl group;

[0177] R 7 is hydrogen, a C 1-6 alkyl group or a ZR 3group;

[0178] R 7' is hydrogen;

[0179] Z and Z' are independently O or S;

[0180] R 3' is C 1-10 alkyl, or C 6-10 aryl optionally substituted with one or more halo groups;

[0181] R 3 is C 1-10 alkyl;

[0182] each n is independently 0 to 4, for example 0, 1 or 2;

[0183] each R 1 is independently C 1-20 hydrocarbyl, for example C 1-10 alkyl.

[0184] Further preferred complexes for use in the present application have the formula (III') or (III):

[0185]

[0186] M is zirconium or hafnium;

[0187] each X is a sigma ligand, preferably each X is independently a hydrogen atom, a halogen atom, a C 1-6 alkoxy group, a C 1-6 alkyl group, a phenyl group or a benzyl group;

[0188] L is a divalent bridge selected from -R'2C- or -R'2Si-, where each R' is independently a hydrogen atom, a C 1-20 alkyl group or a C 3-10 cycloalkyl group;

[0189] R 6 is hydrogen or C 1-10 alkyl;

[0190] R 6 is C 1-10 alkyl or C 6-10 aryl, preferably a tertiary alkyl group;

[0191] R 7 is hydrogen, C 1-6 alkyl or OC 1-6 alkyl;

[0192] Z' is O or S;

[0193] R 3' is C 1-10alkyl or C 6-10 aryl;

[0194] n is independently 0 to 4, for example 0, 1 or 2; and

[0195] each R 1 is independently C 1-10 alkyl.

[0196] Further preferred complexes used in the present application have the formula (IV') or (IV):

[0197]

[0198] M is zirconium or hafnium;

[0199] each X is a sigma ligand, preferably each X is independently a hydrogen atom, a halogen atom, C 1-6 -alkoxy, C 1-6 -alkyl, phenyl or benzyl;

[0200] each R' is independently a hydrogen atom, C 1-20 alkyl or C 3-7 cycloalkyl;

[0201] R 6 is hydrogen or C 1-10 alkyl;

[0202] R 6' is C 1-10 alkyl or C 6-10 aryl, preferably tertiary alkyl;

[0203] R 7 is hydrogen, C 1-6 alkyl or OC 1-6 alkyl;

[0204] Z' is O or S;

[0205] R 3' is C 1-10 alkyl or C 6-10 aryl optionally substituted by one or more halogen groups;

[0206] n is independently 0, 1 to 2; and

[0207] each R 1 is independently C 3-8 alkyl.

[0208] Most particularly, the complexes used in the present application have the formula (V') or (V):

[0209]

[0210] wherein each X is a sigma ligand, preferably each X is independently a hydrogen atom, a halogen atom, a C 1-6 -alkoxy, C 1-6 -alkyl, phenyl or benzyl;

[0211] R' is independently C 1-6 alkyl or C 3-10 cycloalkyl;

[0212] R 1 is independently C 3-8 alkyl;

[0213] R 6 is hydrogen or C 3-8 alkyl;

[0214] R 6' is C 3-8 alkyl or C 6-10 aryl, preferably tertiary C 4-8 alkyl;

[0215] R 3' is C 1-6 alkyl or C 6-10 aryl, optionally substituted with one or more halogen groups; and

[0216] n is independently 0, 1 or 2.

[0217] Particular compounds of the application include:

[0218]

[0219]

[0220] Most preferably, rac-trans-Me2Si(2-Me-4-(p-tBuPh)-Ind)(2-Me-4-Ph-5-OMe-6-tBu- Ind)ZrCl2 is used.

[0221] The synthesis of these materials is described in WO2013 / 007650.

[0222] In order to form the active catalytic species, it is generally necessary to employ a co-catalyst as is well known in the art. Co-catalysts comprising a compound of one or more Group 13 metals (such as organoaluminium compounds, borates or combinations thereof for activating metallocene catalysts) are suitable for use in the present application. Thus, the co-catalyst is preferably an aluminoxane, such as MAO. As an alternative, a borate co-catalyst can also be employed. A combination of aluminoxane and borate co-catalysts can also be used.

[0223] As borate cocatalyst, it is particularly preferred to use B(C6F5)3, C6H5N(CH3)2H:B(C6F5)4, (C6H5)3C:B(C6F5)4 or Ni(CN)4[B(C6F5)3]4 2- .

[0224] Other suitable cocatalysts are described in WO2013 / 007650.

[0225] Suitable amounts of cocatalyst are well known to the skilled person, for example as disclosed in WO2015 / 11135.

[0226] The catalysts for the preparation of random copolymers and propylene homopolymers are ideally provided in the form of solid particles, but are non-supported, i.e. no external support is used. In order to provide the catalysts of the present application in solid form without using an external support, it is preferred to use a liquid-liquid emulsion system. This method comprises forming a dispersion of catalyst components (i) and (ii) in a solvent and solidifying the droplets of the dispersion to form solid particles.

[0227] In particular, the method comprises preparing a solution of one or more catalyst components; dispersing the solution in a solvent to form an emulsion, wherein the one or more catalyst components are present in the droplets of the dispersed phase; immobilising the catalyst components in the dispersed droplets in the absence of an external particulate porous support to form solid particles comprising the catalyst, and optionally recovering said particles.

[0228] The method enables the preparation of active catalyst particles with improved morphology, for example with a predetermined spherical shape and particle size, and without the use of any added external porous support material, such as inorganic oxides, for example silica. Furthermore, desired surface properties can also be obtained. WO2013 / 007650 also contains a comprehensive detail of the method.

[0229] The use of heterogeneous non-supported catalysts (i.e. "self-supported" catalysts) can have the tendency to dissolve to some extent in the polymerisation medium (as a disadvantage), i.e. some of the active catalyst components can leach out of the catalyst particles during slurry polymerisation, whereby the original good catalyst morphology can be lost. These leached catalyst components are very active and can cause problems during polymerisation. Therefore, the amount of leached components should be minimised, i.e. all catalyst components should remain in heterogeneous form.

[0230] Furthermore, due to the high content of catalytically active species in the catalyst system, the self-supported catalyst generates a high temperature at the beginning of the polymerisation, which can lead to the melting of the product material. Both effects, i.e. partial dissolution of the catalyst system and heat generation, can lead to fouling, sheeting and deterioration of the morphology of the polymer material.

[0231] To minimize possible problems associated with high activity or leaching, the catalyst is preferably "prepolymerized" prior to use in the polymerization process. It is noted that in this respect the prepolymerization is part of the catalyst preparation process and becomes a step that is carried out after the formation of the solid catalyst. This catalyst prepolymerization step is not part of the actual polymerization setup, which can also contain a prepolymerization step of the conventional process. After the catalyst prepolymerization step, a solid catalyst is obtained and used in the polymerization.

[0232] The catalyst "prepolymerization" takes place after the solidification step of the liquid-liquid emulsion process described hereinbefore. The prepolymerization can be carried out by known methods described in the art, such as described in WO 2010 / 052263, WO 2010 / 052260 or WO 2010 / 052264. Preferred embodiments of this aspect of the present application are described herein.

[0233] As comonomer in the catalyst prepolymerization step, preferably an alpha-olefin is used. Preferably, a C2-C 10 Olefins, such as ethylene, propylene, 1 -butene, 1 -pentene, 1 -hexene, 4-methyl- 1 -pentene, 1 -heptene, 1 -octene, 1 -nonene, 1 -decene, styrene and vinylcyclohexene. The most preferred alpha-olefins are ethylene and propylene.

[0234] The catalyst prepolymerization can be carried out in the gas phase or in an inert diluent, typically an oil or a fluorinated hydrocarbon, preferably in a fluorinated hydrocarbon or a mixture of fluorinated hydrocarbons. Preferably, a perfluorinated hydrocarbon is used. Such (per)fluorinated hydrocarbons have a melting point typically in the range of 0 to 140 °C, preferably 30 to 120 °C, such as 50 to 110 °C.

[0235] In case the catalyst prepolymerization is carried out in a fluorinated hydrocarbon, the temperature of the prepolymerization step is less than 70 °C, such as in the range of -30 to 70 °C, preferably 0 to 65 °C, more preferably in the range of 20 to 55 °C.

[0236] The pressure in the prepolymerization vessel is preferably higher than atmospheric pressure to minimize air and / or moisture from the outside to enter the catalyst vessel. Preferably, the pressure is in the range of at least 1 to 15 bar, more preferably 2 to 10 bar. The prepolymerization vessel is preferably kept under an inert atmosphere, such as under nitrogen, argon or similar.

[0237] The prepolymerization is continued until a prepolymerization degree (defined as the weight of the polymer matrix / the weight of the solid catalyst before the prepolymerization step) is reached. The prepolymerization degree is less than 25, preferably in the range of 0.5 to 10.0, more preferably in the range of 1.0 to 8.0, most preferably in the range of 2.0 to 6.0.

[0238] Using a catalyst prepolymerization step offers the advantage of minimizing catalyst component leaching, thereby minimizing local overheating.

[0239] After prepolymerization, the catalyst can be separated and stored.

[0240] The polymer used in this article also contains one or more additives, the total amount of which is 0.1 to 2.0 wt% based on the resulting stabilized polymer. The additives are selected from:

[0241] -UV stabilizer

[0242] - Antioxidants

[0243] -Acid remover

[0244] - Chloride inhibitors

[0245] - Dispersant

[0246] -Lactant,

[0247] - Anti-blocking agent,

[0248] -Antistatic agent, and

[0249] -α-nucleating agent.

[0250] Such additives are generally known to those skilled in the art.

[0251] Slip agents are also well known in the art. Slip agents migrate to surfaces and act as lubricants between polymers and between a polymer and a metal roller, thereby reducing the coefficient of friction (CoF). Examples are fatty acid amides, such as erucamide (CAS No. 112-84-5), oleamide (CAS No. 301-02-0), stearamide (CAS No. 124-26-5), or combinations thereof.

[0252] Examples of antioxidants commonly used in this field are sterically hindered phenols (e.g., CAS No. 6683-19-8, also produced by BASF as Irganox 1010FF). TM (For sale), phosphorus-based antioxidants (e.g., CAS No. 31570-04-4, also available from Clariant as Hostanox PAR 24(FF)). TM For sale, or by BASF for Irgafos 168 (FF). TM (For sale), sulfur-based antioxidants (e.g., CAS No. 693-36-7, manufactured by BASF as Irganox PS-802FL) TM (For sale), nitrogen-based antioxidants (e.g., 4,4'-bis(1,1'-dimethylbenzyl)diphenylamine), or antioxidant blends.

[0253] Antacids are also known in the art. Examples are calcium stearate, sodium stearate, zinc stearate, magnesium oxide and zinc oxide, synthetic hydrotalcite (e.g. SHT, CAS No. 11097-59-9), lactylate and lactylates and calcium stearate (CAS No. 1592-23-0) and zinc stearate (CAS No. 557-05-1). Particularly preferred is Hycite 713, commercially available from BASF AG.

[0254] Common anti-blocking agents are natural silicas, such as diatomaceous earth (e.g. CAS No. 60676-86-0 (Superf Floss 1000® TM ), CAS No. 60676-86-0 (Superf Floss E TM ), or CAS No. 60676-86-0 (Celite 499 TM )), synthetic silicas (e.g. CAS No. 7631-86-9, CAS No. 7631-86-9, CAS No. 7631-86-9, CAS No. 7631-86-9, CAS No. 7631-86-9, CAS No. 7631-86-9, CAS No. 112926-00-8, CAS No. 7631-86-9, or CAS No. 7631-86-9), silicates (e.g. aluminum silicate (kaolin) CAS No. 1318-74-7, sodium aluminum silicate CAS No. 1344-00-9, calcined kaolin CAS No. 92704-41-1, aluminum silicate CAS No. 1327-36-2, or calcium silicate CAS No. 1344-95-2), synthetic zeolites (e.g. hydrated sodium calcium aluminum silicate CAS No. 1344-01-0, CAS No. 1344-01-0, or hydrated sodium calcium aluminum silicate CAS No. 1344-01-0).

[0255] Suitable UV-stabilizers are, for example, bis-(2,2,6,6-tetramethyl-4-piperidyl)-sebacate (CAS No. 52829-07-9, Tinuvin 770); 2-hydroxy-4-n-octyloxy-benzophenone (CAS No. 1843-05-6, Chimassorb 81).

[0256] Alpha nucleating agents can also be added, such as sodium benzoate (CAS No. 532-32-1); a mixture of bis[2,2'-methylene-bis(4,6-di-tert-butylphenyl)phosphoric acid]aluminum hydroxide and lithium myristate (commercially available as Adekastab NA-21 from Adeka Palmarole, France), or 1,3:2,4-bis(3,4-dimethylbenzylidene)sorbitol (CAS No. 135861-56-2, commercially available as Millad 3988 from Milliken, USA).

[0257] Suitable antistatic agents are, for example, glycerol esters (CAS No. 97593-29-8) or ethoxylated amines (CAS No. 71786-60-2 or 61791-31-9) or ethoxylated amides (CAS No. 204-393-1).

[0258] Generally, these additives are added in amounts of 100 to 1,000 ppm for each single component.

[0259] Preferably, at least an antioxidant is added.

[0260] If additional polymer components are blended, their amount should preferably be less than 2.0 wt.-%, relative to the resulting polymer mixture.

[0261] When the polypropylene homopolymer or random copolymer is prepared by a Ziegler Natta catalyst, nucleation by a polymer nucleating agent is preferred.

[0262] The propylene homopolymer composition (H-PP) comprises a reactor blend of a propylene homopolymer and a polymer nucleating agent.

[0263] The polymer nucleating agent is present in an amount in the range of 20 to 300 wt-ppm, more preferably 20 to 200 wt-ppm, most preferably 20 to 100 wt-ppm, relative to the total weight of the nucleated polypropylene homopolymer.

[0264] The polymer nucleating agent comprises a monomer (I) having the general formula

[0265] H2C=CH-CHR 1 R 2 (I)

[0266] wherein R 1 and R 2 are individual alkyl groups having more than one carbon atom, or form an optionally substituted saturated, unsaturated or aromatic ring or fused ring system containing 4 to 20 carbon atoms, wherein, in case R 1 and R 2 form an aromatic ring, the hydrogen atom of the -CHR 1 R 2 moiety is absent.

[0267] Preferably, the monomer (I) of the polymer nucleating agent is selected from the group consisting of vinyl cyclohexane, vinyl cyclopentane and 4-methyl-pent-1-ene, most preferably the monomer is vinyl cyclohexane.

[0268] Although other monomers, most commonly propylene monomers, can be present in the polymer nucleating agent, preferably the polymer nucleating agent consists of monomers having the general formula (I).

[0269] In a particularly preferred embodiment, the polymeric nucleating agent is a homopolymer of vinylcyclohexane (pVCH).

[0270] Since the nucleated propylene homopolymer is present as a reactor blend of a propylene homopolymer and a polymeric nucleating agent when using a Ziegler Natta catalyst, all polymer properties relevant to the propylene homopolymer derived from the Ziegler Natta catalyst have been measured for the nucleated propylene homopolymer.

[0271] The propylene homopolymer and the random propylene copolymer can be produced in the presence of:

[0272] (a) a Ziegler-Natta catalyst (ZN-C) comprising a compound of a transition metal of IUPAC Groups 4 to 6 (TC), a compound of a Group 2 metal (MC), and an internal donor (ID) free of phthalic acid esters;

[0273] (b) optionally a co-catalyst (Co), and

[0274] (c) optionally an external donor (ED).

[0275] The propylene homopolymer composition (H-PP) is preferably produced in a sequential polymerization process, regardless of the catalyst nature.

[0276] The same above process layout can be used again for the random polypropylene copolymer, regardless of the catalyst nature.

[0277] Therefore, the propylene homopolymer in the first polymerization reactor (R1), i.e. the polymer slurry in the loop reactor (LR) comprising the first fraction of the final propylene homopolymer, more preferably the first fraction of the final propylene homopolymer, is directly fed into the second polymerization reactor (R2), i.e. the (first) gas phase reactor (GPR1), without performing a flashing step between the stages. This direct feeding is described in EP 887379 A, EP 887380 A, EP 887381 A and EP 991684 A. By “direct feeding” is meant a process where the content of the first polymerization reactor (R1), i.e. the loop reactor (LR), comprising the polymer slurry of the first fraction of the propylene homopolymer composition (H-PP1), is directly fed to the next stage gas phase reactor.

[0278] Suitable Ziegler Natta catalysts with internal donors free of phthalic acid esters are well known in the art, for example described in WO 2015197435 A1, WO 2015197354 A2 and WO 2015197434 A1.

[0279] The process for the preparation of the multilayer film according to the present application is simple and straightforward and can be accomplished according to common general knowledge following the steps:

[0280] (a) preparing a cast film by extruding a base layer polypropylene homopolymer and / or random propylene copolymer;

[0281] (b) co-extruding a barrier cast film comprising a lamination layer, a tie layer 1, a core layer, a tie layer 2 and a sealing layer (LL / TL1 / CL / TL2 / SL); and

[0282] (c) pressing lamination at a temperature in the range of 120 to 130 °C of the cast film prepared in step a) with the barrier cast film prepared in step b). DETAILED DESCRIPTION

[0283] In the following, two particularly preferred embodiments of the multilayer film are described. The first particularly preferred embodiment relates to:

[0284] A multilayer film made of a polymeric material, the polymeric material comprising polypropylene homopolymer, polypropylene copolymer and EVOH in an amount of at least 96 wt%, preferably at least 98 wt% relative to the polymeric material, the multilayer film comprising at least 6 layers:

[0285] a base layer (BL) / a lamination layer (LL) / a tie layer 1 (TL1) / a core layer (CL) / a tie layer 2 (TL2) / a sealing layer (SL),

[0286] wherein all layers are free of polyethylene terephthalate (PET);

[0287] the base layer (BL) comprises polypropylene homopolymer;

[0288] the lamination layer (LL) comprises random propylene copolymer;

[0289] the tie layer 1 (TL1) comprises a polar modified polypropylene copolymer selected from maleic anhydride grafted polypropylene (PP-g-MAH), maleic anhydride grafted polypropylene co-grafted with styrene (PP-g-MAH-coSt), or a combination thereof;

[0290] the core layer (CL) comprises ethylene-vinyl alcohol copolymer (EVOH);

[0291] the tie layer 2 (TL2) comprises a polar modified polypropylene copolymer selected from maleic anhydride grafted polypropylene (PP-g-MAH), maleic anhydride grafted polypropylene co-grafted with styrene (PP-g-MAH-coSt), or a combination thereof;

[0292] the sealing layer (SL) comprises random propylene copolymer;

[0293] the multilayer film is not biaxially oriented,

[0294] wherein the polypropylene homopolymer comprised in the base layer (BL) has one or more of the following properties:

[0295] - a melt flow rate MFR2of 1.5 to 15 g / 10 min, preferably 2.0 to 12 g / 10 min (ISO 1133; 2.16

[0296] kg; 230 °C);

[0297] - a melting temperature (DSC, ISO 11357) in the range of 150 to 158 °C;

[0298] - a content of 2.1 -regio defects of 0.2 mol% or more, preferably 0.35 mol% or more, determined by NMR spectroscopy;

[0299] - derived from a single-site catalyst;

[0300] - preferably

[0301] o a blend of a single-site catalyst derived polymer and a Ziegler-Natta derived polymer,

[0302] o more preferably a blend of a single-site catalyst derived polymer and a Ziegler-Natta derived polymer containing a polymeric nucleating agent,

[0303] o even more preferably a blend obtained by blending 97.0 to 99.0 wt% of a single-site catalyst derived polymer with 1.0 to 3.0 wt% of a Ziegler-Natta derived polymer containing a polymeric nucleating agent, wherein the percentages refer to the sum of the blend,

[0304] o most preferably a blend obtained by blending 97.0 to 99.0 wt% of a single-site catalyst derived polymer with 1.0 to 3.0

[0305] wt% of a Ziegler-Natta derived polymer containing a polyvinylcyclohexane, wherein the percentages refer to the sum of the blend;

[0306] - a xylene cold soluble fraction (analysis according to ISO 16152) of less than 0.5 wt%;

[0307] - a content of greater than 97.0 wt% relative to the base layer (BL).

[0308] All preferred aspects disclosed in the description and claims of the present application shall also apply to the particularly preferred embodiments of the present application, as appropriate.

[0309] A second particularly preferred embodiment relates to:

[0310] A multilayer film made of a polymeric material, said polymeric material comprising a content of polypropylene homopolymer, polypropylene copolymer and EVOH of at least 96 wt%, preferably at least 98 wt%, relative to the polymeric material, said multilayer film comprising at least 6 layers:

[0311] base layer (BL) / lamination layer (LL) / tie layer 1 (TL1) / core layer (CL) / tie layer 2 (TL2) / sealing layer (SL),

[0312] wherein all layers are free of polyethylene terephthalate (PET);

[0313] the base layer (BL) comprises a polypropylene homopolymer;

[0314] the lamination layer (LL) comprises a random propylene copolymer;

[0315] the tie layer 1 (TL1) comprises a polar modified polypropylene copolymer selected from a maleic anhydride grafted polypropylene (PP-g-MAH), a maleic anhydride grafted polypropylene co-grafted with styrene (PP-g-MAH-coSt) or a combination thereof;

[0316] the core layer (CL) comprises an ethylene-vinyl alcohol copolymer (EVOH);

[0317] the tie layer 2 (TL2) comprises a polar modified polypropylene copolymer selected from a maleic anhydride grafted polypropylene (PP-g-MAH), a maleic anhydride grafted polypropylene co-grafted with styrene (PP-g-MAH-coSt) or a combination thereof;

[0318] the sealing layer (SL) comprises a random propylene copolymer;

[0319] the multilayer film is not biaxially oriented,

[0320] wherein the polypropylene homopolymer comprised in the base layer (BL) has one or more of the following properties:

[0321] - a melt flow rate MFR2 of 1.5 to 15 g / 10 min, preferably 2.0 to 12 g / 10 min (ISO 1133; 2.16 kg; 230 °C);

[0322] - a melting temperature (DSC, ISO 11357) in the range of 150 to 158 °C;

[0323] - a content of 2.1 -regio defects of 0.2 mol% or more, preferably 0.35 mol% or more, determined by NMR spectroscopy;

[0324] - derived from a single site catalyst;

[0325] - preferably

[0326] o a blend of a single-site catalyst-derived polymer and a Ziegler-Natta derived polymer,

[0327] o more preferably a blend of a single-site catalyst-derived polymer and a Ziegler-Natta derived polymer containing a polymeric nucleating agent,

[0328] o even more preferably a blend obtained by blending 97.0 to 99.0 wt% of a single-site catalyst-derived polymer with 1.0 to 3.0 wt% of a Ziegler-Natta derived polymer containing a polymeric nucleating agent, wherein the percentages refer to the sum of the blend,

[0329] o most preferably a blend obtained by blending 97.0 to 99.0 wt% of a single-site catalyst-derived polymer with 1.0 to 3.0

[0330] wt% of a Ziegler-Natta derived polymer containing a polyvinylcyclohexane, wherein the percentages refer to the sum of the blend;

[0331] - a xylene cold soluble fraction (analysed according to ISO 16152) of less than 0.5 wt%;

[0332] - an amount greater than 97.0 wt.% with respect to the base layer (BL), and

[0333] further,

[0334] the random propylene copolymer contained in the lamination layer (LL) and / or in the sealing layer (SL) has one or more of the following properties:

[0335] - a melting temperature (DSC, ISO 11357) in the range of 123 to 136 °C;

[0336] - a content of 2.1 - regio defects (determined by NMR spectroscopy) of 0.2 mol% or more, preferably of 0.35 mol% or more, even more preferably of 0.2 to 1.0 mol%, most preferably of 0.35 to 1.0 mol%;

[0337] - derived from a single-site catalyst;

[0338] - a flexural modulus (ISO 178; measured on injection moulded samples, determined at 23 °C) of at least 800 MPa;

[0339] - an amount greater than 97.0 wt.% with respect to the lamination layer (LL).

[0340] All preferred aspects disclosed in the present application specification and claims shall also apply to the particularly preferred embodiments of the present application, as appropriate.

[0341] A third particularly preferred embodiment relates to:

[0342] A material obtainable by mechanical recycling of the multilayer film described in the general specification and claims herein or the packaging described herein, preferably having one or more of the following properties:

[0343] - a melt flow rate of 3.0 to 10 g / 10 min (ISO 1133; 2.16 kg; 230 °C);

[0344] - a tensile modulus (ISO 527, injection molded specimens) of 1300 to 2000 MPa;

[0345] - a strain at break (ISO 527, injection molded specimens) of at least 600%.

[0346] All preferred aspects disclosed in the present application specification and claims shall also apply to the particularly preferred embodiments of the present application, as appropriate.

[0347] Experiments

[0348] Measurement methods

[0349] a) MFR2 is measured according to ISO 1133 (230 °C, 2.16 kg load) (230 °C for polypropylene polymers; 190 °C for polyethylene polymers).

[0350] b) Quantification of the microstructure by NMR spectroscopy

[0351] Quantitative nuclear magnetic resonance (NMR) spectroscopy is used to quantify isotacticity and regio-regularity.

[0352] For 1 H and 13 C, quantitative 13 C{ 1 H} NMR spectra in solution state are recorded using a Bruker Advance III 400 NMR spectrometer operating at 400.15 MHz and 100.62 MHz, respectively. All spectra are recorded using nitrogen as the gas for all pneumatically operated devices, at 125 °C, using a 10 mm extended temperature probe optimized for 13 C.

[0353] For propylene homopolymers, about 200 mg of material was dissolved in 1,2-tetrachloroethane-d2(TCE-d2). To ensure a homogeneous solution, after initial sample preparation in the hot zone, the NMR tube was further heated in a rotating furnace for at least 1 hour. The tube was spun at 10 Hz when inserted into the magnet. This setting was chosen mainly for the high resolution required for tacticity distribution quantification (Busico, V., Cipullo, R., Prog. Polym. Sci. 26 (2001) 443; Busico, V.; Cipullo, R., Monaco, G., Vacatello, M., Segre, A. L., Macromolecules 30 (1997) 6251). Standard single-pulse excitation with NOE and bi-level WALTZ16 decoupling was employed (Zhou, Z., Kuemmerle, R., Qiu, X., Redwine, D., Cong, R., Taha, A., Baugh, D. Winniford, B., J. Mag. Reson. 187 (2007) 225; Busico, V., Carbonniere, P., Cipullo, R., Pellecchia, R., Severn, J., Talarico, G., Macromol. Rapid Commun. 2007, 28, 11289). A total of 8192 (8k) transients were acquired for each spectrum.

[0354] Quantification 13 C{ 1 The1H NMR spectra were processed, integrated, and the relevant quantification properties were determined from the integrals by means of a proprietary computer program.

[0355] For propylene homopolymers, all chemical shifts were internally referenced to the methyl isotactic pentad (mmmm) at 21.85 ppm.

[0356] Characteristic signals corresponding to regio defects (Resconi, L., Cavallo, L., Fait, A., Piemontesi, F., Chem. Rev. 2000, 100, 1253; Wang, W-J., Zhu, S., Macromolecules 33 (2000), 1157; Cheng, H. N., Macromolecules 17 (1984), 1950) or comonomer were observed.

[0357] Quantification of the stereoregularity distribution was performed by integration of the methyl region between 23.6 and 19.7 ppm, calibrated on any site not related to the stereosequence of interest (Busico, V., Cipullo, R., Prog. Polym. Sci. 26 (2001) 443; Busico, V., Cipullo, R., Monaco, G., Vacatello, M., Segre, A. L., Macromolecules 30 (1997) 6251).

[0358] In particular, the effect of the regio defects and of the comonomer on the quantification of the stereoregularity distribution was corrected by subtracting the integral representative of the regio defects and of the comonomer from the specific integral region of the stereosequence.

[0359] The isotacticity was determined at pentad level and was reported as the percentage of isotactic pentads (mmmm) sequences with respect to the total of pentad sequences:

[0360] [mmmm] % = 100 x (mmmm / sum of all pentads)

[0361] The presence of 2,1-erythro regiodefects was shown by the presence of two methyl sites at 17.7 ppm and 17.2 ppm and was confirmed by other characteristic sites. No characteristic signals corresponding to other types of regiodefects were observed (Resconi, L., Cavallo, L., Fait, A., Piemontesi, F., Chem. Rev. 2000, 100, 1253).

[0362] The amount of 2,1-erythro regiodefects was quantified using the average integration of the two characteristic methyl sites at 17.7 ppm and 17.2 ppm:

[0363] P 21e = (I e6 + I e8 ) / 2

[0364] The amount of 1,2 primary inserted propylene was quantified on the basis of the methyl region and was corrected for sites in this region not related to the primary insertion and for primary insertion sites excluded from this region:

[0365] P 12 = I CH3 + P 21e

[0366] The total amount of propylene was quantified as the sum of the primary inserted propylene and all other regiodefects present:

[0367] P 总 = P12 +P 21e

[0368] The molar percentage of 2,1 erythro regio defects was quantified relative to all propylene:

[0369] [21e] mol% = 100 x (P 21e / P 总 )

[0370] c) based on 13 C NMR spectroscopy for calibration standards

[0371] For H and 1 C, respectively, quantitative 13 C{ 13 H} NMR spectra were recorded in solution state using a Bruker Avance III 400 NMR spectrometer operating at 400.15 and 100.62 MHz for H and 1 C, respectively. All spectra were recorded using nitrogen for all pneumatic devices at 125 °C using a 10 mm extended temperature probe optimized for 13 C. Approximately 200 mg of material was dissolved in 3 ml of 1,2-tetrachloroethane-d2 (TCE-d2) with chromium (III) acetylacetonate (Cr(acac)3) to obtain a 65 mM solution of relaxer in solvent (Singh, G., Kothari, A., Gupta, V., Polymer Testing 28 5 (2009), 475). To ensure a homogeneous solution, the NMR tube was further heated in a rotating oven for at least 1 hour after the initial sample was prepared in the heating block. The tube was spun at 10 Hz after it was inserted into the magnet. This setting was chosen mainly to obtain high resolution and is quantitatively required due to the accurate quantification of ethylene content. Standard single pulse excitation was employed with optimized tip angle, 1 s recycle delay and double level WALTZ16 decoupling scheme without NOE (Zhou, Z., Kuemmerle, R., Qiu, X., Redwine, D., Cong, R., Taha, A., Baugh, D. Winniford, B., J. Mag. Reson. 187 (2007) 225, Busico, V., Carbonniere, P., Cipullo, R., Pellecchia, R., Severn, J., Talarico, G., Macromol. Rapid Commun. 2007, 28, 1128). A total of 6144 (6k) transients were acquired per spectrum. For quantitative 13 C{ 1H}NMR spectra were processed, integrated, and the relevant quantitative properties were determined from the integrals. Using the chemical shift of the solvent, all chemical shifts were referenced indirectly to the central methylene of the ethylene block (EEE) at 30.00 ppm. This approach can be made comparable even in the absence of this structural unit. The characteristic signals corresponding to ethylene incorporation were observed (Cheng, H. N., Macromolecules 17 (1984), 1950) and the comonomer fraction was calculated as the fraction of ethylene in the polymer relative to all monomers in the polymer:

[0372] fE= (E / (P+E))

[0373] Using the method of Wang et al. (Wang, W-J., Zhu, S., Macromolecules 33 (2000), 1157), the comonomer fraction was calculated from the integrals of the signals in the 13 C{ 1 The comonomer fraction was quantified by integrating multiple signals over the entire spectral region in the1H spectrum. This approach was chosen due to its robustness and ability to indicate the presence of regional imperfections when needed. The integration region was slightly adjusted to improve applicability over the entire range of comonomer contents encountered. For systems with very low ethylene content, where only isolated ethylenes in PPEPP sequences are observed, the method of Wang et al. was modified to reduce the influence of the integration of sites that are no longer present. This approach reduces the overestimation of the ethylene content for such systems and is achieved by reducing the number of sites used to determine the absolute ethylene content to:

[0374] E = 0.5 (Sββ + Sβγ + Sβδ + 0.5 (Sαβ + Sαγ))

[0375] By using this set of sites, the corresponding integral equation becomes:

[0376] E = 0.5 (I H + I G + 0.5 (I C + I D ))

[0377] The same notation as used in the article of Wang et al. (Wang, W-J., Zhu, S., Macromolecules 33 (2000), 1157) was used. The equation for the absolute propylene content was not modified. The molar percentage of comonomer incorporation was calculated from the mole fraction:

[0378] E [mol%] = 100 x fE

[0379] The weight percentage of comonomer incorporation was calculated from the mole fraction:

[0380] E [wt%] = 100 x (fE x 28.06) / ((fE x 28.06) + ((1 - fE) x 42.08))

[0381] d) Tensile test

[0382] Injection moulded samples (dog bone shape, 4 mm thickness) were moulded according to ISO 527-2 (1 B) at 230 °C, manufactured according to EN ISO 1873-2 and the tensile modulus, tensile strength and elongation at break were measured according to ISO 527-2 at 23 °C (for tensile modulus the crosshead speed was 1 mm / min, for the others 50 mm / min).

[0383] c) Melting temperature Tm m and crystallization temperature Tc c

[0384] Melting temperature Tm m Differential scanning calorimetry (DSC) was determined according to ISO 11357-3 with a TA-Instruments 2920 Dual-Cell with RSC refrigeration unit and data station. A heating / cooling / heating cycle between +23 °C and +210 °C was applied with a heating and cooling rate of 10 °C / min. The crystallization temperature (Tc) was determined from the cooling step, while the melting temperature (Tm) and the melting enthalpy (Hm) were determined in the second heating step. c m m

[0385] c) Xylene cold soluble (XCS)

[0386] The xylene cold soluble (XCS) fraction as defined and described herein was determined according to ISO 16152 as follows: 2.0 g of polymer was dissolved in 250 ml of p-xylene at 135 °C under stirring. After 30 minutes, the solution was cooled at ambient temperature for 15 minutes and then left standing for 30 minutes at 25 ± 0.5 °C. The solution was filtered with filter paper into two 100 ml flasks. The solution from the first 100 ml flask was evaporated under a stream of nitrogen and the residue was dried under vacuum at 90 °C to constant weight. Then, the xylene soluble fraction (in percent) can be determined as follows:

[0387] XCS% = (100 x m x V0) / (m0 x v);

[0388] m0 = initial polymer amount (g); m = weight of residue (g); V0 = initial volume (ml); v = volume of analysed sample (ml).

[0389] ​​​d) Barrier properties of the multilayer film (WVTR and OTR)

[0390] Water vapor transmission rate - WVTR (38°C; 85% relative humidity, RH) and oxygen transmission rate - OTR (23°C; 100% O2; 0% RH) were measured after conditioning of the multilayer film for at least 96 hours under standard laboratory conditions (23°C, 30-50% RH). For WVTR, ISO 15106-2:2003 was used with detection by infrared sensor. For OTR, ISO 15105-1 :2007 (using the pressure differential method) was used.

[0391] Examples

[0392] Multilayer films were prepared from the polymers in Table 1 characterized by the parameters as shown in Table 2.

[0393] Table 1 : Multilayer film structure and polymers

[0394]

[0395] Table 2: Characteristics of the polymers

[0396]

[0397] 230 °C for PP, 190 °C for PE and EVOH; n.d. - not defined

[0398] Two experimental unit point polypropylene grades were prepared in a Borstar TM Prepared in a pilot plant PP unit using a liquid bulk prepolymerization reactor, a liquid bulk loop reactor and three gas phase reactors of which one was used. The polymerization conditions for SSC-PPH1 and SSC-PPR2 are shown in Table 3.

[0399] The catalysts used in the polymerization process for the two experimental unit point polypropylene grades were prepared as follows:

[0400] The metallocene MC1 (rac-trans-dimethylsilanediyl(2-methyl-4-phenyl-5-methoxy-6-tert-butyl-indenyl)(2-methyl-4-(4-tert-butylphenyl)indenyl)zirconium dichloride) has been synthesized as described in WO 2013 / 007650.

[0401] The catalyst was prepared using the metallocene MC1 and the catalyst system of MAO and trityl tetra(pentafluorophenyl)borate according to catalyst 3 of WO 2015 / 11135 with the proviso that the surfactant is 2,3,3,3-tetrafluoro-2-(1,1,2,2,3,3,3-heptafluoropropoxy)-1 -propanol.

[0402] Table 3: Polymerization data for SSC-PP grades

[0403]

[0404] SSC-PPH1 was compounded with 2.0 wt% of the above mentioned commercial Borealis HD905CF, 0.05 wt% of pentaerythrityl tetrakis(3-(3',5'-di-tert-butyl-4- hydroxyphenyl)propionate (available as Irganox 1010 from BASF AG, Germany; CAS No. 6683-19-8), 0.05 wt% of tris(2,4-di-tert-butylphenyl) phosphite (available as Irgafos 168 from BASF AG, Germany; CAS No. 31570-04-4) and 0.03 wt% of synthetic hydrotalcite (available as Hycite 713 from BASF AG, Germany; CAS No. 11097-59-9) in a co-rotating twin screw extruder Coperion ZSK 47 at 220 °C.

[0405] SSC-PPR2 was compounded with 0.05 wt% of pentaerythrityl tetrakis(3-(3',5'-di-tert- butyl-4-hydroxyphenyl)propionate (available as Irganox 1010 from BASF AG, Germany; CAS No. 6683-19-8), 0.05 wt% of tris(2,4-di-tert-butylphenyl) phosphite (available as Irgafos 168 from BASF AG, Germany; CAS No. 31570-04-4) and 0.03 wt% of synthetic hydrotalcite (available as Hycite 713 from BASF AG, Germany; CAS No. 11097-59-9) in a co-rotating twin screw extruder Coperion ZSK 47 at 220 °C. The viscosity break was performed using an appropriate amount of 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane to a MFR2 of 11.0 g / 10 min. The XCS, T m , C2 (total) and 2,1 -regio defects content did not change.

[0406] The films for the base layer (BL) were prepared from PPA or PPB by single layer cast film extrusion to the target thickness. The 5 layer barrier films consisting of a lamination layer (LL), a tie layer 1 (TL1), a core layer (CL), a tie layer 2 (TL2) and a sealing layer (SL) were prepared by cast film co-extrusion using a multi-layer die. Subsequently, the 2 films were hot laminated by compression at 124 °C. The final layer thickness values are shown in Table 4. The comparative examples were made from pure base layer (CE1) and polyethylene (CE2, CE3, CE4) and polyethylene terephthalate (PET).

[0407]

[0408] All multilayer structures were comminuted and re-extruded in a conventional twin-screw extruder at 220 °C.

[0409] It can be seen that the multilayer structures of the present application have a remarkable strain at break, excellent OTR and WVTR performance and acceptable tensile properties, in particular a higher tensile modulus compared to the pure PP film of CE1.

[0410] From the comparison of IE3 and IE4 it can be seen that a base layer made of a polypropylene homopolymer derived from a single-site catalyst leads to an increase in strain at break, in addition to a decrease in F max Puncture energy can be increased. Water vapor transmission rate (WVTR) remains at the same level, while oxygen transmission rate (OTR) is decreased.

[0411] From the comparison of IE4 and IE2 it can be seen that when the lamination layer is additionally made of a polypropylene homopolymer derived from a single-site catalyst (as shown in IE2), the strain at break and F max Puncture energy can even be further improved. In addition, the tensile modulus can also be increased.

[0412] The comparison of IE1 and IE2 further shows the influence of a lamination layer made of a polypropylene homopolymer derived from a single-site catalyst (as a separate effect).

[0413] Comparing the inventive examples with the comparative example CE2, the influence of using polypropylene with polyethylene can be understood. The use of polypropylene significantly increases the stiffness (which is reflected in the tensile modulus), significantly improves the strain at break, and significantly increases the oxygen transmission rate (OTR) as well as the water vapor transmission rate (WVTR).

[0414] After mechanical recycling (i.e. comminution and re-extrusion), the inventive examples show an impressive strain at break, in particular an excellent balance between tensile modulus and strain at break, making mixed plastics a very attractive material for many applications. The mechanically recycled mixture (IM) of the inventive examples IE2 and IE4 is characterized in that the sheet originating from a base layer comprising a polypropylene homopolymer derived from a single-site catalyst shows surprisingly high strain at break values.

[0415] The mechanically recycled mixture (IM) of the inventive examples IE1 and IE3 is characterized in that the sheet originating from a base layer comprising a polypropylene homopolymer derived from a Ziegler-Natta catalyst shows surprisingly high stiffness.

Claims

1. A multilayer film made of a polymer material, wherein the polymer material comprises at least 96 wt%, preferably at least 98 wt%, of a polypropylene homopolymer, a polypropylene copolymer, and EVOH, and the multilayer film comprises at least 6 layers: Base layer (BL) / Laminate layer (LL) / Connecting layer 1 (TL1) / Core layer (CL) / Connecting layer 2 (TL2) / Sealing layer (SL) in, None of the layers contain polyethylene terephthalate (PET); The base layer (BL) comprises polypropylene homopolymer and / or random propylene copolymer; The laminate (LL) contains a random propylene copolymer; The connecting layer 1 (TL1) comprises a polar modified polypropylene copolymer, which is preferably selected from maleic anhydride-grafted polypropylene (PP-g-MAH), maleic anhydride-grafted polypropylene (PP-g-MAH-coSt) co-grafted with styrene, or a combination thereof. The core layer (CL) contains an ethylene-vinyl alcohol copolymer (EVOH); The connecting layer 2 (TL2) comprises a polar modified polypropylene copolymer, which is preferably selected from maleic anhydride-grafted polypropylene (PP-g-MAH), or maleic anhydride-grafted polypropylene (PP-g-MAH-coSt) co-grafted with styrene, or a combination thereof. The sealing layer (SL) comprises a random propylene copolymer; and The multilayer film is not biaxially oriented.

2. The multilayer film according to claim 1, wherein, The water vapor transmission rate (WVTR, ISO 15106-2:2003, measured at 38°C; 85% relative humidity) of the multilayer membrane is less than 0.30 g / m³. 2 / sky, and / or The oxygen permeability (OTR, 23°C; 100% O2; 0% RH; differential pressure method) of the multilayer membrane, measured according to ISO 15105-1:2007, is less than 5.0 cm. 3 / m 2 ·Tian·Ba, preferably less than 2.0cm 3 / m 2 · Tian·ba, the optimal size is less than 1.4cm 3 / m 2 ·Tian·Ba.

3. The multilayer film according to claim 1 or 2, wherein, The polypropylene homopolymer and / or random propylene copolymer contained in the base layer (BL) have one or more of the following properties: - The melt flow rate (MFR2) is 1.5 to 15 g / 10 min, preferably 2.0 to 12 g / 10 min (ISO 1133; 2.16 kg; 230 °C); - The melting temperature (DSC, ISO 11357) is in the range of 150 to 172°C, preferably in the range of 150 to 158°C; - In the case of copolymers, ethylene is the only comonomer present; - Less than 0.9 wt% of ethylene-derived units, preferably less than 0.5 wt% of ethylene-derived units (determined by NMR spectroscopy); - Flexural modulus (ISO 178; measured on injection-molded specimens at 23°C) is at least 1600 MPa, preferably at most 2300 MPa; - The content of defects in region 2.1, as determined by NMR spectroscopy, is 0.2 mol% or more, preferably 0.35 mol% or more; -Derived from unit-point catalyst; - Preferably, it is a blend of polymers derived from o-unit catalysts and polymers derived from Ziegler-Natta. More preferably, a blend of polymers derived from single-point catalysts and Ziegler-Natta-derived polymers containing polymer nucleating agents. o or even more preferably, a blend obtained by blending 97.0 to 99.0 wt% of a polymer derived from a single-site catalyst with 1.0 to 3.0 wt% of a Ziegler-Natta-derived polymer containing a polymer nucleating agent. The percentage refers to the total amount of the blends. The most preferred blend is obtained by blending 97.0 to 99.0 wt% of a polymer derived from a single-point catalyst with 1.0 to 3.0 wt% of a Ziegler-Natta-derived polymer containing polyvinylcyclohexane. Wherein, the percentage refers to the total amount of the blends; - Xylene cold soluble fraction (analyzed according to ISO 16152) less than 0.5 wt%; - Content greater than 97.0 wt% relative to base layer (BL).

4. The multilayer film according to claim 1 or 2, wherein, The random propylene copolymer contained in the laminate (LL) and / or sealing layer (SL) has one or more of the following properties: - Melt flow rate (MFR2) of 5.0 to 15 g / 10 min (ISO 1133; 2.16 kg; 190 °C); - Ethylene is the only existing comonomer; - The ethylene content (determined by NMR spectroscopy) is 1.0 to 6.0 wt%, preferably 1.0 to 3.0 wt%; - The melting temperature (DSC, ISO 11357) is in the range of 122 to 145°C, preferably in the range of 123 to 136°C; -2.1- The content of regional defects (determined by NMR spectroscopy) is 0.2 mol% or more, preferably 0.35 mol% or more, even more preferably 0.2 mol% to 1.0 mol%, and most preferably 0.35 mol% to 1.0 mol%. -Derived from phthalate-free Ziegler-Natta catalysts or preferably derived from unit-point catalysts; - Xylene cold soluble fraction (analyzed according to ISO 16152) less than 1.0 wt%, preferably less than 0.8 wt%; - Flexural modulus (ISO 178; measured on injection-molded specimens at 23°C) is at least 600 MPa, preferably at least 800 MPa; - Viscosity-reducing cracking; - The content is greater than 97.0 wt% relative to either the laminate (LL) or the sealant (SL).

5. The multilayer film according to any one of the preceding claims, wherein, The polypropylene homopolymer and / or random propylene copolymer contained in the base layer (BL) have one or more of the following properties: - Melting temperature (DSC, ISO 11357) is in the range of 150 to 158°C; - Less than 0.5 wt% of ethylene-derived units (determined by NMR spectroscopy); -2.1- The content of regional defects (determined by NMR spectroscopy) is 0.2 mol% or more, preferably 0.35 mol% or more, even more preferably 0.2 mol% to 1.0 mol%, and most preferably 0.35 mol% to 1.0 mol%. -Derived from unit point catalyst; - Content greater than 97.0 wt% relative to base layer (BL); Furthermore, The random propylene copolymer contained in the laminate (LL) and / or sealing layer (SL) has one or more of the following properties: - Melting temperature (DSC, ISO 11357) is in the range of 123 to 136°C; -2.1- The content of regional defects (determined by NMR spectroscopy) is 0.2 mol% or more, preferably 0.35 mol% or more, even more preferably 0.2 mol% to 1.0 mol%, and most preferably 0.35 mol% to 1.0 mol%. -Derived from unit-point catalyst; - Flexural modulus (ISO 178; measured on injection-molded specimens at 23°C) is at least 800 MPa; - Content greater than 97.0 wt% relative to laminate (LL).

6. The multilayer film according to any one of the preceding claims, wherein, The laminate (LL) and the sealant (SL) contain the same random propylene copolymer.

7. The multilayer film according to any one of the preceding claims, wherein, The ethylene-vinyl alcohol copolymer (EVOH) forming the core layer (CL) has one or more of the following properties: - Density (ISO 1183) is 1190 to 1230 kg / m³ 3 ; - Melt flow rate (MFR2) is 0.5 to 5.0 g / 10 min (ISO 1133; 2.16 kg; 190 °C); - Melting temperature (DSC; ISO 11357) is above 175°C, preferably up to 190°C.

8. The multilayer film according to claim 7, wherein, The core layer (CL) based on ethylene-vinyl alcohol copolymer (EVOH) is encapsulated by two connecting layers (TL1, TL2), which are made of maleic anhydride-grafted polypropylene (PP-g-MAH) and / or maleic anhydride-grafted polypropylene (PP-g-MAH-coSt) containing co-grafted styrene.

9. The multilayer film according to any one of the preceding claims, wherein, The polar modified polypropylene copolymer contained in the connecting layer 2 (TL2) has one or more of the following properties: - is maleic anhydride-grafted polypropylene (PP-g-MAH), optionally maleic anhydride-grafted polypropylene (PP-g-MAH-coSt) containing co-grafted styrene. - Melt flow rate of 7.0 to 100.0 g / 10 min (ISO 1133; 5 kg; 190 °C); - Density (ISO 1183) is 870 to 900 kg / m³ 3 ; - Melting temperature (ASTM D3418) is in the range of 135°C to 155°C; - The same material as the connecting layer 1 (TL1).

10. Multilayer films, wherein, The layer thickness is as follows: - The base layer (BL) is 50 to 350 μm, preferably 70 to 300 μm; and / or - The laminate (LL) is 5 to 50 μm, preferably 7 to 35 μm; and / or - The connecting layer 1 (TL1) is 1 to 7 μm, preferably 1 to 4 μm; and / or - The core layer (CL) is 3 to 15 μm, preferably 4 to 12 μm; and / or - The connecting layer 2 (TL2) is 1 to 7 μm, preferably 1 to 4 μm; and / or - The sealing layer (SL) is 5 to 50 μm, preferably 7 to 35 μm, and Optionally, the total thickness of the multilayer film is 70 to 440 μm.

11. The multilayer film according to any one of the preceding claims, wherein, The multilayer film can be obtained through the following steps: (a) A cast film is prepared by extruding a base layer of polypropylene homopolymer and / or random propylene copolymer; (b) Co-extruded barrier cast film, the barrier cast film comprising a laminate, a connecting layer 1, a core layer, a connecting layer 2, and a sealing layer (LL / TL1 / CL / TL2 / SL); and (c) The cast film prepared in step a) and the barrier cast film prepared in step b) are pressed and laminated at a temperature in the range of 120 to 130°C. Optionally, the total thickness of the multilayer film is 70 to 440 μm.

12. A package comprising a tray and a lid made of any one of the multilayer films of claims 1-11.

13. The packaging according to claim 12, wherein, The content of polypropylene, polypropylene copolymer and EVOH relative to the packaging is at least 96 wt%, preferably at least 98 wt%.

14. A material obtainable by mechanically recycling any of the multilayer films of claims 1-11 or the packaging of claim 12 or 13, said material preferably having one or more of the following properties: - Melt flow rate of 3.0 to 10 g / 10 min (ISO 1133; 2.16 kg; 230 °C); - Tensile modulus (ISO 527, injection molded specimens) is 1300 to 2000 MPa; - Fracture strain (ISO 527, injection molded specimen) is at least 400%, preferably at least 500%, and most preferably at least 600%.

15. The material according to claim 14, wherein, The material has one or more of the following properties: - Melt flow rate of 3.0 to 10 g / 10 min (ISO 1133; 2.16 kg; 230 °C); - Fracture strain (ISO 527, injection molded specimens) is at least 700%.

Images