Film comprising polyethylene for packaging applications

Abstract

The present invention relates to a film comprising or consisting of a sealing layer comprising or consisting of an ethylene-based polymer, preferably comprising units derived from ethylene and one of more comonomer selected from 1-butene, 1-hexene and 1-octene, more preferably 1- octene, wherein the ethylene-based polymer has: • a density of ≥ 850 and ≤ 920 kg / m3, preferably ≥ 870 and ≤ 910 kg / m3, more preferably ≥ 890 and ≤ 910 kg / m3, as determined in accordance with ASTM D792 (2013); • a melt mass-flow rate determined at 190°C under a load of 2.16 kg in accordance with ASTM D1238-13 (MFR2) of ≥ 0.2 and ≤ 5.0 g / 10 min; • a melt mass-flow rate determined at 190°C under a load of 21.6 kg in accordance with ASTM D1238-13 (MFR21) of ≥ 5 and ≤ 100 g / 10 min, preferably ≥ 25 and ≤ 100 g / 10 min; and • a melt mass-flow rate ratio (MRR) determined as MFR21 / MFR2 of ≤ 30.0, preferably of ≥ 20.0 and ≤ 30.0; preferably wherein the sealing layer comprises ≥ 60.0 wt% of the ethylene-based polymer, preferably ≥ 70.0 wt%, more preferably ≥ 70.0 and ≤ 95.0 wt, even more preferably ≥ 70.0 and ≤ 90.0 wt%, with regard to the total weight of the layer. Such film has desirable seal-through-contamination ability, as well as low surface friction, and thus allows for high-speed high-quality packing of for example powdery, liquid or viscous products whilst enabling high quality thermal seal formation.

Description

Film

[0001] The present invention relates to a film comprising polyethylene. In particular, the invention relates to a film comprising a polyethylene sealing layer. The invention also related to a package comprising such film.

[0002] Polyethylene materials are abundantly used for packaging applications. Polyethylenes exhibit a wide array of properties that render them particularly suitable for packaging applications. For example, their inertness and impermeability are very desirable properties for packaging perishable goods, such as foodstuffs. By use of polyethylene materials in packaging solutions of such products, the shelf life of such products can be significantly improved. This also contributes to the reduction of waste of such foodstuffs, and thereby is favourable in view of the sustainable use of such scare resources.

[0003] In the packaging industry, packaging solutions comprising polyethylenes include for example bag-type packages, in which the bag is produced using a polyethylene-containing film or laminate. Such bag-type packages are commonly sealed by applying a thermal seal. In producing such package, first, a bag is made that contains an opening for supplying the contents into the package, such as for example an open top end. Then, the bag is filled with the contents, upon which the bag is sealed by thermally sealing the laminate, such as by contacting the inner surface of the back to form a closure upon heat exposure. In such healing technique, the film material at least partially softens or melts, and becomes adhesive, so that by applying a force and subsequently reducing the temperature to a temperature at which the film material solidifies, a closed seal is formed.

[0004] To allow for forming such seal, the inner side of the package needs to be made of a material that allows for such softening and adhesion to be performed. The material that is to be present on that inner side of the package thus needs to comply with certain material characteristics that render it suitable for such use. In addition, packaging process efficiency and quality requirements result in the need for such material to be sealable at high packaging speeds and at low temperatures.

[0005] What is further important for such inner layer of a package is that the adherence of the good that is to be packed to the surface is minimised. When supplying certain critical goods tothe package, such as for example ground coffee, the adherence must be so that the bag is filled perfectly in all corners. This means that the flow of the goods to be contained in the bag during filling of the package must be so that no blockage will occur that could lead to suboptimal filling of the package. In particular when filling is performed at high line speeds, which in view of procedural efficiency is throughout desirable in industry, a reliable filling of the package is paramount. Ease of flow of the content, and thus low friction between content and inner surface of the package, is required to enable this.

[0006] A further requirement for reliable and high-speed filling of such packages is that the seal that is made by the thermal sealing method is sufficiently tight. In particular in packaging of powdery or liquid substances, it may occur that at the area where the seal is to be formed, a certain quantity of such substance remains, thereby contaminating the area to be sealed. In order to ensure reliable quality of sealing, the package is to be formed from a material that is capable of being sealed even though a certain amount of contamination on the sealing surface, also referred to as ‘seal-through contamination’ ability or ‘caulkability’. If such caulkability properties are not sufficiently high, this may result in packages having so-called channel leaks that can lead to product waste and spoilage.

[0007] The present inventors have now provided a film comprising or consisting of a sealing layer comprising or consisting of an ethylene-based polymer, preferably comprising units derived from ethylene and one of more comonomer selected from 1-butene, 1-hexene and 1- octene, more preferably 1-octene, wherein the ethylene-based polymer has:• a density of > 850 and < 920 kg / m3, preferably > 870 and < 910 kg / m3, more preferably > 890 and < 910 kg / m3, as determined in accordance with ASTM D792 (2013);• a melt mass-flow rate determined at 190°C under a load of 2.16 kg in accordance with ASTM D1238-13 (MFR2) of > 0.2 and < 5.0 g / 10 min;• a melt mass-flow rate determined at 190°C under a load of 21.6 kg in accordance with ASTM D1238-13 (MFR21) of > 5 and < 100 g / 10 min, preferably > 25 and < 100 g / 10 min; and• a melt mass-flow rate ratio (MRR) determined as MFR21 / MFR2 of < 30.0, preferably of > 20.0 and < 30.0;preferably wherein the sealing layer comprises > 60.0 wt% of the ethylene-based polymer, preferably > 70.0 wt%, more preferably > 70.0 and < 95.0 wt, even more preferably > 70.0 and < 90.0 wt%, with regard to the total weight of the layer.

[0008] Such film has desirable seal-through-contamination ability, as well as low surface friction, and thus allows for high-speed high-quality packing of for example powdery, liquid or viscous products whilst enabling high quality thermal seal formation.

[0009] The ethylene-based polymer may for example have an MFR2 of > 0.2 and < 3.0, preferably of > 0.5 and < 2.0, more preferably of > 0.5 and < 1.5 g / 10 min.

[0010] The ethylene-based polymer may for example have an MFR21 of > 25 and < 75, preferably of > 30 and < 75, more preferably of > 30 and < 50 g / 10 min.

[0011] It is preferred that the ethylene-based polymer comprises > 15.0 and < 25.0 wt% of units derived from the one or more comonomer, more preferably 17.5 and < 22.5 wt%, with regard to the total weight of the ethylene-based polymer.

[0012] The ethylene-based polymer may for example have a weight-average molecular weight (Mw) of > 70 kg / mol, preferably of > 70 and < 200 kg / mol, more preferably of > 80 and < 150 kg / mol, even more preferably of > 90 and < 120 kg / mol, wherein the Mwis determined in accordance with ASTM D6474 (2012).

[0013] The ethylene-based polymer may for example have a number-average molecular weight (Mn) of > 20 and < 50 kg / mol, preferably of > 25 and < 40 kg / mol, more preferably of > 30 and < 40 kg / mol, even more preferably of > 33 and < 40 kg / mol, wherein the Mnis determined in accordance with ASTM D6474 (2012).

[0014] The ethylene-based polymer may for example have a z-average molecular weight (Mz) of > 150 and < 300 kg / mol, preferably of > 175 and < 225 kg / mol, more preferably of > 185 and < 225 kg / mol, wherein the Mzis determined in accordance with ASTM D6474 (2012).

[0015] Preferably, the ethylene-based polymer has a molecular weight distribution Mw / Mnof > 2.5 and < 3.5, preferably of > 2.5 and < 3.0, more preferably of > 2.5 and < 2.8, wherein Mwand Mnare determined in accordance with ASTM D6474 (2012).

[0016] The ethylene-based polymer may for example have a fraction eluted in a-TREF below 30°C of < 15.0 wt%, preferably > 5.0 and < 15.0 wt%, more preferably >7.5 and < 12.5 wt%, as determined according to the method of the description.

[0017] The ethylene-based polymer may for example have a long chain branching content of < 4.0 branches / 100,000 carbon atoms, preferably < 3.0, as determined in accordance with the method of the description.

[0018] The ethylene-based polymer may for example have a shear thinning index of < 5.0, preferably > 1.0 and < 5.0, wherein the shear thinning index is calculated as the ratio r)o.oi / r|ioo, wherein r|O.oi is the complex viscosity at 0.01 rad / s and r|i00is the complex viscosity at 100 rad / s, both measured according to ISO 6721-10 at 190°C.

[0019] The ethylene-based polymer may for example have a zero shear viscosity (r|o) of < 10,000 Pa.s, preferably of < 7,500 Pa.s, more preferably of > 5,000 and < 7,500, as determined in accordance with ISO 6721-10.

[0020] The sealing layer may for example comprise a high-density polyethylene (HDPE), preferably having a density of > 940 and < 970 kg / m3, more preferably of > 945 and < 965 kg / m3, even more preferably of > 950 and < 965 kg / m3. The HDPE may for example have an MFR2 of > 0.2 and < 5.0 g / 10 min, preferably of > 0.5 and < 3.0 g / 10 min. The sealing layer may for example comprise > 5.0 and < 25.0 wt% of the HDPE, preferably > 5.0 and < 15.0 wt%, with regard to the total weight of the sealing layer.

[0021] The sealing layer may for example comprise a linear low-density polyethylene (LLDPE) preferably having a density of > 910 and < 935 kg / m3, more preferably of > 915 and < 930 kg / m3, even more preferably of > 915 and < 925 kg / m3. The LLDPE may for example have an MFR2 of > 0.2 and < 5.0 g / 10 min, preferably of > 0.5 and < 3.0 g / 10 min. The sealing layer may for example comprise > 5.0 and < 25.0 wt% of the LLDPE, preferably > 5.0 and < 15.0 wt%, with regard to the total weight of the sealing layer. The LLDPE may for example be a copolymer of ethylene and at least one comonomer selected from 1 -butene, 1-hexene and 1-octene.

[0022] The sealing layer may for example comprise a low-density polyethylene (LDPE), preferably having a density of > 905 and < 930 kg / m3, more preferably of > 910 and < 925 kg / m3, even more preferably of > 915 and < 925 kg / m3. The LDPE may for example have anMFR2 of > 0.2 and < 5.0 g / 10 min, preferably of > 0.5 and < 3.0 g / 10 min. The sealing layer may for example comprise > 5.0 and < 25.0 wt% of the LDPE, preferably > 5.0 and < 15.0 wt%, with regard to the total weight of the sealing layer.

[0023] The film may for example be a cast film or a blown film. Preferably, the film is a multilayer film, and the sealing layer is positioned as one outer layer of the film. It is particularly preferred that the film is a 3-layer film, a 5-layer film or a 7-layer film.

[0024] The film may for example have a first outer layer (A), a second outer layer (C), and one or more inner layers (B), wherein the second outer layer (C) is the sealing layer, preferably the first outer layer (A) and each of the one or more inner layers (B) are of the same composition.

[0025] The film may for example have a thickness of > 25 and < 200 pm, preferably >25 and < 100 pm.

[0026] The sealing layer may for example consist of the ethylene-based polymer, and optionally a slip agent, preferably an erucamide, and / or an antiblock agent, preferably a natural silicate.

[0027] The invention, in one of its embodiments, also relates to a laminate comprising the film of the invention. For example, such laminate may comprise at least a first film adhered to a second film, wherein the first film is the film according to the invention, wherein the first film is adhered to the second film via its first outer layer (A).

[0028] The laminate may comprise, in this order, the first film, an optional second film and a third film, wherein:• the second film is a metallic film, preferably an aluminium film; and• the third film is a polymer film, preferably a bidirectionally oriented polyethylene (BOPE), bidirectionally oriented polypropylene (BOPP) or bidirectionally oriented polyethylene terephthalate (BOPET) film; preferably wherein the first film is laminate to the third film or the first film is laminated to the second film and the second film laminated to the third film; and preferably wherein lamination of a film to another film is done by an adhesive layer.

[0029] The invention also relates, in an embodiment, to a package comprising or consisting of the film according to the invention, or the laminate according to the invention. Such package may for example be a gusseted bag, a stand-up pouch, or a pillow pouch.

[0030] In yet a further embodiment, the invention also relates to the use of a sealing layer comprising a first ethylene-based copolymer having a density of > 850 and < 920 kg / m3, preferably > 870 and < 910 kg / m3, more preferably > 890 and < 910 kg / m3, as determined in accordance with ASTM D792 (2013), and a melt mass-flow rate determined at 190°C under a load of 2.16 kg in accordance with ASTM D1238-13 of > 0.2 and < 5.0 g / 10 min; wherein the first ethylene-based copolymer is an ethylene / 1 -octene copolymer comprising < 18.0 wt% of polymeric units derived from 1 -octene, with regard to the total weight of the first ethylene-based copolymer, and wherein the first ethylene-based copolymer has a molecular weight distribution Mw / Mnof > 3.0, wherein Mwis the weight average molecular weight and Mnis the number average molecular weight, as determined in accordance with ASTM D6474 (2012) in a film, to reduce the tendency for contamination in the heat seal area and / or the caulkability of a package, preferably a gusseted bag, comprising such film.

[0031] The comonomer content and the comonomer type may be determined by13C NMR, such as on a Bruker Avance 500 spectrometer equipped with a cryogenically cooled probe head operating at 125°C, whereby the samples are dissolved at 130°C in C2D2CI4 containing DBPC as stabiliser.

[0032] According to the invention, analytical temperature rising elution fractionation, also referred to as a-TREF, may be carried out using a Polymer Char Crystaf-TREF 300 equipped with stainless steel columns having a length of 15 cm and an internal diameter of 7.8 mm, with a solution containing 4 mg / ml of sample prepared in 1 ,2-dichlorobenzene stabilised with 1 g / l Topanol CA (1 ,1 ,3-tri(3-tert-butyl-4-hydroxy-6-methylphenyl)butane) and 1 g / l Irgafos 168 (tri(2,4-di-tert-butylphenyl) phosphite) at a temperature of 150°C for 1 hour. The solution may be further stabilised for 45 minutes at 95°C under continuous stirring at 200 rpm before analyses. For analyses, the solution was crystallised from 95°C to 30°C using a cooling rate of 0.1°C / min. Elution may be performed with a heating rate of 1°C / min from 30°C to 140°C. The set-up may be cleaned at 150°C. The sample injection volume may be 300 pl, and the pump flow rate during elution 0.5 ml / min. The volume between the column and the detector may be 313 pl. The fraction that is eluted at a temperature of <30.0°C may in the context of the present invention be calculated by subtracting the sum of the fraction eluted >30.0°C from 100%, thus the total of the fraction eluted < 30.0°C, and the fraction eluted >30.0°C to add up to 100.0 wt%.

[0033] Particularly, a-TREF may be carried out using a Polymer Char Crystaf-TREF 300 using a solution containing 4 mg / ml of the polymer in 1 ,2-dichlorobenzene, wherein the solution is stabilised with 1 g / l 1,1,3-tri(3-tert-butyl-4-hydroxy-6-methylphenyl)butane and 1 g / l tri(2,4-di- tert-butylphenyl) phosphite) at a temperature of 150°C for 1 hour, and further stabilised for 45 minutes at 95°C under continuous stirring at 200 rpm, wherein the prior to analyses the solution is crystallised from 95°C to 30°C using a cooling rate of 0.1°C / min, and elution is performed at a heating rate of 1°C / min from 30°C to 140°C, and wherein the equipment has been cleaned at 150°C.

[0034] The invention will now be illustrated by the following non-limiting examples.

[0035] In the context of the present invention, the below materials were used in the experiments.Table 1 : Materials used in experimental film / laminate testing.Table 2: Characteristics of ethylene-based polymer materials used in the present invention.

[0036] Wherein• The MFR2 is the melt mass-flow rate, determined at 190°C under a load of 2.16 kg, and the MFR21 is the melt mass-flow rate determined at 190°C under a load of 21.6 kg, both determined in accordance with ASTM D1238 (2013);• The MRR is the ratio of the MFR21 I MFR2;• The density is determined in accordance with ASTM D792 (2013);• The fraction a-TREF <30°C is the fraction eluted in an a-TREF analysis conducted as described above below 30°C; • The weight-average molecular weight (Mw), the number-average molecular weight (Mn) , and the z-average molecular weight (Mz) were determined in accordance with ASTM D6474 (2012);• The comonomer content indicates the weight quantity of units present in the polymer that are derived from the comonomer, also referred to as the quantity of moieties derived from the comonomer, with regard to the total weight of the polymer, expressed in wt%;• The comonomer type indicates the type of comonomer used in the production of the polymer, where C8 is 1 -octene;• The intrinsic viscosity was determined according to ASTM D2857-95 (Re 2007), in decalin at 135°C;• LOB is long chain branching, expressed in the number of branches per 10.000 carbon atoms in the polymer molecule, determined via GPC-IR;• The shear thinning index was calculated as the ratio qo.oi / r|ioo, wherein qos is the complex viscosity at 0.01 rad / s and r)ioo is the complex viscosity at 100 rad / s, both measured according to ISO 6721-10 at 190°C;• The zero shear viscosity (r|0) was determined in accordance with ISO 6721-10.

[0037] The comonomer content and the comonomer type were determined by13C NMR on a Bruker Avance 500 spectrometer equipped with a cryogenically cooled probe head operating at 125°O, whereby the samples are dissolved at 130°C in C2D2CI4 containing DBPO as stabiliser.

[0038] The a-TREF analyses were carried out using a Polymer Char Crystaf TREF 300 device using a solution containing 4mg / ml of sample in 1,2-dichlorobenzene stabilised with 1 g / l Topanol CA (1 ,1 ,3-tri(3-tert-butyl-4-hydroxy-6-methylphenyl)butane) and 1 g / l Irgafos 168 (tri(2,4-di-tert-butylphenyl)phosphite) at a temperature of 150°C for 1 hour. The solution was further stabilised for 45 minutes at 95°C under continuous stirring at 200 rpm before analyses. For analyses, the solution was crystallised from 95°C to 30°C using a cooling rate of 0.1 °C / min. Elution was performed with a heating rate of 1 °C / min from 30°C to 140°C. The set-up was cleaned at 150°C.

[0039] Using the defined materials, 3-layer films were produced. The 3-layer PE films were fabricated on a 3-layer coextrusion blown line equipped with 3 extruders via processing parameters as shown in table 3. The L / / D ratio was 30:1 for all three extruders and the screw diameter was 40 / 40 / 35 mm for extruder A / B / C respectively. The blown line had a die diameter of 200 mm and die gap of 2.0 mm. Cooling of the extruded film was done via a dual-lip cooling system. The conditions used in the film fabrication were: average film thickness = 50 ± 5 pm; blow up ratio (BUR) = 2.5; corona treatment = 40 dyne (0.04 N / m); layer ratio = 20:60:20; line speed = 9 m / min. The tube film was opened and cut to film with width of 50 cm.Table 3: Blown film processing parameters

[0040] Wherein the layer ratio is the weight fraction of each given layer compared to the weight of the total film; the screw speed is the rotation speed of the extruder screws in rpm; the temperature profile reflects the set temperatures of the zones of the extruders, starting at feed zone; and Tdie is the set temperature of the die of the extruder.

[0041] By varying the ethylene-based polymer in the formulation of the sealing layer, 5 different films were produced according to the formulation as in table 4 below.Table 4: Formulations of 3-layer blown films

[0042] Using the films prepared as above, laminates were produced by laminating the 3-layer film samples with a BOPET substrate (12 pm in thickness) using a solventless laminator. The adhesive was a two-component polyurethane. The coating weight of adhesives applied to the BOPET film was 1.4 ~ 1.6 g / m2. The speed of the laminator was 100 m / min. The final structure of the laminates was: sealing layer C I inner layer B / outer layer A / adhesive layer I BOPET, and the final thickness of laminates was ~ 62 pm. After lamination, the film rolls were cured for 48 hours at 40 °C.

[0043] Of the 3-layer films and laminates prepared as described above, properties were tested. The results of these tests are presented in the table below.

[0044] Wherein:• The maximum hot tack force is the maximum of the tack force / temperature curve obtained via testing according to ASTM F1921 (2012), on a seal of 25 mm width, expressed in N / 15 mm;• The seal strength at given temperature and the maximum seal strength were obtained by testing in accordance with ASTM F88 (2015), on a seal of 25 mm width, expressed in N / 15 mm;• The seal initiation temperature is the temperature at which a seal of given strength is obtained as determined by seal strength testing in accordance with ASTM F88 (2015);• The static and kinetic coefficient of friction were determined in accordance with ASTM D1894 -14.

[0045] The testing of the seal strength of contaminated laminates was done by preparing samples via using coffee powder as representative of powder-like contaminant simulant. The film sample was cut in machine direction (MD) with a width of 50 mm and a proper length to ensure the test operation of seal strength. An area with 40 mm length in transverse direction (TD) and 20 mm width in MD was marked out on the film sample. The seal width of the sealing bar was 10 mm, so 20 mm was chosen to ensure that the contamination is distributed over the full width of the seal. The required amount of coffee powder was weighted using Mettler-Toledo balance with resolution of 0.0001 g. In order to facilitate the contamination preparation and sealing operation, a PC plate with 2 mm of thickness was made into a tool. This tool had an inner hole with a larger width and length than the seal jaw. The detail procedure for sample preparation and sealing operation was as below:1) The PC plate tool was put onto the film sample with sealing layer up, ensuring that the two marked areas were positioned in the middle of inner hole.2) Adhesive tape was used to fix the position of first film sample to the PC tool.3) 0.020 g of coffee powder was weighed and applied to the 40 x 20 mm marked area to achieve a 25 m2 / g contamination density via evenly distribution of the powder manually.4) The first film was folded back to the PC plate to cover the first layer of it.5) The PC tool with the contaminated film samples was manually placed between the seal jaws to make the seals.

[0046] A Brugger HSG-C apparatus was used to make the seal using two heating platen with size of 150 mm in length and 10 mm in width under sealing pressure of 450 N and dwell time of 1s. After 40 hours conditioning in the oven under 23°C at 50% humidity, the sealing samples were cut into testing specimens with width of 15 mm. For each sample at each sealing temperature, 4 contamination areas were made with each contamination area making two specimens, which means 8 specimens in total were tested for each sample at each sealing temperature.

Claims

Claims1. Film comprising or consisting of a sealing layer comprising or consisting of an ethylenebased polymer, preferably comprising units derived from ethylene and one of more comonomer selected from 1 -butene, 1 -hexene and 1 -octene, more preferably 1 -octene, wherein the ethylene-based polymer has:• a density of > 850 and < 920 kg / m3, preferably > 870 and < 910 kg / m3, more preferably > 890 and < 910 kg / m3, as determined in accordance with ASTM D792 (2013);• a melt mass-flow rate determined at 190°C under a load of 2.16 kg in accordance with ASTM D1238-13 (MFR2) of > 0.2 and < 5.0 g / 10 min;• a melt mass-flow rate determined at 190°C under a load of 21.6 kg in accordance with ASTM D1238-13 (MFR21) of > 5 and < 100 g / 10 min, preferably > 25 and < 100 g / 10 min; and• a melt mass-flow rate ratio (MRR) determined as MFR21 / MFR2 of < 30.0, preferably of > 20.0 and < 30.0; preferably wherein the sealing layer comprises > 60.0 wt% of the ethylene-based polymer, preferably > 70.0 wt%, more preferably > 70.0 and < 95.0 wt, even more preferably > 70.0 and < 90.0 wt%, with regard to the total weight of the layer; and preferably wherein the ethylene-based polymer comprises > 15.0 and < 25.0 wt% of units derived from the one or more comonomer, more preferably 17.5 and < 22.5 wt%, with regard to the total weight of the ethylene-based polymer.

2. Film according to claim 1 , wherein the ethylene-based polymer has• a weight-average molecular weight (Mw) of > 70 kg / mol, preferably of > 70 and < 200 kg / mol, more preferably of > 80 and < 150 kg / mol, even more preferably of > 90 and < 120 kg / mol, wherein the Mwis determined in accordance with ASTM D6474 (2012); and / or• a number-average molecular weight (Mnj of > 20 and < 50 kg / mol, preferably of > 25 and < 40 kg / mol, more preferably of > 30 and < 40 kg / mol, even more preferably of > 33 and < 40 kg / mol, wherein the Mnis determined in accordance with ASTM D6474 (2012); and / ora z-average molecular weight (Mz) of > 150 and < 300 kg / mol, preferably of > 175 and < 225 kg / mol, more preferably of > 185 and < 225 kg / mol, wherein the Mzis determined in accordance with ASTM D6474 (2012).

3. Film according to any one of claims 1-2, wherein the ethylene-based polymer has a molecular weight distribution Mw / Mnof > 2.5 and < 3.5, preferably of > 2.5 and < 3.0, more preferably of > 2.5 and < 2.8, wherein Mwand Mnare determined in accordance with ASTM D6474 (2012).

4. Film according to any one of claims 1-3, wherein the ethylene-based polymer has a fraction eluted in a-TREF below 30°C of < 15.0 wt%, preferably > 5.0 and < 15.0 wt%, more preferably >7.5 and < 12.5 wt%, as determined according to the method of the description.

5. Film according to any one of claims 1-4, wherein the ethylene-based polymer has a long chain branching content of < 4.0 branches 1 100,000 carbon atoms, as determined in accordance with the method of the description.

6. Film according to any one of claims 1-5, wherein the ethylene-based polymer has a shear thinning index of < 5.0, wherein the shear thinning index is calculated as the ratio r)o.oi / r]ioo, wherein r]o.oi is the complex viscosity at 0.01 rad / s and rjioo is the complex viscosity at 100 rad / s, both measured according to ISO 6721-10 at 190°C.

7. Film according to any one of claims 1-6, wherein the ethylene-based polymer has a zero shear viscosity (q0) of < 10,000 Pa.s, preferably of < 7,500 Pa.s, as determined in accordance with ISO 6721-10.

8. Film according to any one of claims 1-7, wherein the film is a cast film or a blown film, preferably wherein the film has a thickness of > 25 and < 200 pm.

9. Film according to any one of claims 1-8, wherein the film is a multilayer film, and the sealing layer is positioned as one outer layer of the film, preferably wherein the film is a 3- layer film, a 5-layer film or a 7-layer film.

10. Film according to claim 9, wherein the film has a first outer layer (A), a second outer layer (C), and one or more inner layers (B), wherein the second outer layer (C) is the sealinglayer, preferably wherein the first outer layer (A) and each of the one or more inner layers (B) are of the same composition.

11. Film according to any one of claims 1-10, wherein the sealing layer consists of the ethylene-based polymer, and optionally a slip agent, preferably an erucamide, and / or an antiblock agent, preferably a natural silicate.

12. Laminate comprising at least a first film adhered to a second film, wherein the first film is the film according to any one of claims 1-11 , wherein the first film is adhered to the second film via its first outer layer (A).

13. Laminate according to claim 12, wherein the laminate comprises, in this order, the first film, an optional second film and a third film, wherein:• the second film is a metallic film, preferably an aluminium film; and• the third film is a polymer film, preferably a bidirectionally oriented polyethylene (BOPE), bidirectionally oriented polypropylene (BOPP) or bidirectionally oriented polyethylene terephthalate (BOPET) film; preferably wherein the first film is laminate to the third film or the first film is laminated to the second film and the second film laminated to the third film; and preferably wherein lamination of a film to another film is done by an adhesive layer.

14. Package comprising or consisting of the film according to any one of claims 1-11 or the laminate according to any one of claims 12-13, preferably wherein the package is a gusseted bag, a stand-up pouch, or a pillow pouch.

15. Use of a sealing layer comprising a first ethylene-based copolymer having a density of > 850 and < 920 kg / m3, preferably > 870 and < 910 kg / m3, more preferably > 890 and < 910 kg / m3, as determined in accordance with ASTM D792 (2013), and a melt mass-flow rate determined at 190°C under a load of 2.16 kg in accordance with ASTM D1238-13 of > 0.2 and < 5.0 g / 10 min; wherein the first ethylene-based copolymer is an ethylene / 1 -octene copolymer comprising < 18.0 wt% of polymeric units derived from 1 -octene, with regard to the total weight of the first ethylene-based copolymer, and wherein the first ethylene-based copolymer has a molecular weight distribution Mw / Mnof > 3.0, wherein Mwis the weight average molecular weight and Mnisthe number average molecular weight, as determined in accordance with ASTM D6474 (2012); in a film, to reduce the tendency for contamination in the heat seal area and / or the caulkability of a package, preferably a gusseted bag, comprising such film.

Images