Flexible laminate with excellent sealing performance

Abstract

The present invention relates to a laminate film comprising a polyethylene sealant film including at least an outer layer O, an inner layer I and a core layer C, the core layer C being present between the outer layer O and the inner layer I, wherein the inner layer I has a compressive strength of 915 to 925 kg / m 3 and melt flow rate (MFR) of 0.5 to 3.0 g / 10 min as determined by ISO 1133 2 %, wherein the weight percent is based on the total weight of the inner layer composition; and The present invention relates to a substrate film laminated to a polyethylene sealant film, wherein the substrate film comprises a polyester polymer selected from the group consisting of polyethylene terephthalate, polybutylene terephthalate and polytrimethylene terephthalate, and mixtures thereof, and the seal initiation temperature SIT (5N) of the laminate film is less than 100°C, determined at the inner layer of the polyethylene sealant film according to ASTM F2029, ASTM F88. The present invention further relates to an article comprising said laminate film, and the use of the laminate film for packaging an article. Furthermore, the present invention relates to the use of the polyethylene sealant film to improve the sealing performance of a substrate film comprising a polyester polymer.

Description

[Technical field]

[0001] The present invention relates to a laminate film comprising a polyethylene sealant film and a substrate film comprising a polyester-based polymer. Further, the present invention relates to an article comprising the laminate film and the use of the laminate film in packaging applications. [Background technology]

[0002] Laminate films in the packaging industry are often prepared from flexible film structures that include a polyethylene sealant film bonded to a substrate film, typically made of polyester (e.g. PET), biaxially oriented polypropylene (BOPP) or biaxially oriented polyamide (BOPA). Laminate films are generally used to meet multifunctional requirements, i.e., the sealant film is used to ensure sufficient toughness-related properties, package seal integrity and lower sealing temperatures; whereas, the substrate film is used for stiffness and barrier-related properties, ensuring improved shelf life of the packaged goods and subsequent handling operations during packaging in Form, Fill & Seal (FFS) machines.

[0003] To achieve high speed packaging processes, it is important that the sealing layer of the film has a low seal initiation temperature (SIT). A lower seal initiation temperature of the sealing layer reduces the time to seal the package, allowing for faster packaging line speeds.

[0004] Lower sealing temperatures can be achieved, for example, by reducing the density of the polyethylene present in the sealing layer. However, polyethylene polymers with lower density suffer from several drawbacks. First, a higher comonomer content (which is usually more expensive than ethylene monomer) is required to achieve the reduced density of the polymer, resulting in higher production costs. Second, the reduction in density of the polyethylene copolymers simultaneously leads to a reduction in the melting point. As a result, the film becomes more sticky and difficult to handle when running on machines with very high line speeds. There is therefore a need to develop film structures that contain moderately high density polyethylene polymers in the sealing layer, but with similar or even improved sealing performance, reflected in a lower seal initiation temperature. Furthermore, these film structures must meet all the requirements necessary for their use in packaging applications, such as optical properties, aesthetics, stiffness, moisture resistance, gas resistance, etc.

[0005] Polyester-based film structures such as PET films have long proven themselves as suitable films for packaging applications: they are characterized by excellent stiffness and optical properties and, thus, are widely applied in this sector.

[0006] For example, WO 2018 / 195269 describes a laminate structure for packaging applications comprising a first film comprising biaxially oriented polyethylene terephthalate (BOPET); and a second film laminated to the first film, comprising a coextruded film, the second film comprising a polyamide layer and a polyolefin layer, the polyolefin layer comprising a first composition, the first composition comprising at least one ethylene polymer, the first composition having a molecular weight comonomer distribution index (MWCDI) value greater than 0.9 and ... 10 Melt index ratio (I / I2 ≥ 7.0-1.2 × log(I2) 10 / I2). The publication does not disclose any details regarding the sealing properties of the laminate construction. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] International Publication No. 2018 / 195269 Summary of the Invention [Problem to be solved by the invention]

[0008] Many commercially available laminate structures are prepared from multiple polymers. Sorting and recycling such laminates is difficult and expensive, but recyclability is a high priority for today's packaging materials.

[0009] SUMMARY OF THE DISCLOSURE In view of the above, it is a general object of the present invention to provide a new laminate structure for packaging applications.

[0010] The object of the present invention is to provide a laminate structure based on a common and already established film, which has good heat resistance and mechanical properties and, as a result, exhibits excellent performance in high speed VFFS operations, while at the same time exhibiting excellent sealing performance.

[0011] It is a further object of the present invention to provide a laminate structure that has good optical properties (eg, gloss and haze) that also meet the aesthetic requirements met by films for packaging applications.

[0012] Finally, it is an object of the present invention to provide a laminate structure that is relatively easy to recycle and has low cost. [Means for solving the problem]

[0013] The combination of these objects is achieved by the present invention, which comprises: a) a polyethylene sealant film comprising at least an outer layer O, an inner layer I and a core layer C, the core layer C being between the outer layer O and the inner layer I; Here, the inner layer I has a compressive strength of 915 to 925 kg / m 3and a melt flow rate (MFR2) of 0.5 to 3.0 g / 10 min as determined by ISO 1133, wherein the weight percent is based on the total weight of the inner layer composition; and b) a substrate film laminated to the polyethylene sealant film; wherein the substrate film comprises a polyester polymer selected from the group consisting of polyethylene terephthalate, polybutylene terephthalate, and polytrimethylene terephthalate, and mixtures thereof; Laminate films, including Wherein, the seal initiation temperature SIT (5N) of the laminate film is less than 100°C, and is determined by ASTM F2029, ASTM F88 for the inner layer of the polyethylene sealant film; to provide.

[0014] The present invention is based on the finding that an advantageous laminate structure can be provided as a laminate film by combining a polyester-based base film and a polyethylene sealant film, the inner layer of the polyethylene sealant film having specific properties and containing a specific content of LLDPE, and the seal initiation temperature SIT (5N) of the laminate film in the inner layer of the polyethylene sealant film is low, at 100°C or less.

[0015] By using LLDPE, the same density (e.g. 918 kg / m 3 It has surprisingly been found that improved sealing performance can be achieved with the LLDPE 100 having a viscosity of 100 MPa (100 MPa) over other LLDPEs having a viscosity of 100 MPa (100 MPa). This improvement has been observed in the base sealant film before lamination as well as in the laminate film. Thus, reducing the density - which may be done to reduce the sealing temperature - is not necessary and does not result in the disadvantages mentioned above (stickiness, cost, etc.).

[0016] The use of a polyethylene sealant film comprising the described composition together with a polyester-based substrate film provides a laminate film that benefits from the established properties of the substrate film in terms of their mechanical and optical properties, and further imparts improved sealing performance to the laminate film.Furthermore, the mechanical and optical properties of the substrate film are not significantly affected by the presence of the sealant film.

[0017] Thus, the polyethylene sealant film may be used to improve the sealing performance of commercially available polyester-based substrate films.

[0018] Finally, the laminate films of the present invention are of relatively simple composition based on a few polymers and, as a result, are easier and less costly to recycle than more complex laminate structures. [Brief description of the drawings]

[0019] [Figure 1] Comparison of the heat seal initiation temperature at 5N measured on the inner layer of the sealant film before lamination and the density of the LLDPE of the examples.

[0020] [Diagram 2] Sealing temperature curve of sealant film before lamination.

[0021] [Diagram 3] Hot tack temperature curve of sealant film before lamination.

[0022] [Figure 4] Comparison of the seal initiation temperature at 5N measured on the inner layer of the sealant film in the laminate film and the density of the LLDPE in the examples.

[0023] [Diagram 5] Hot tack temperature curve for laminate film. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] In the present invention, the laminate film comprises or consists of a sealant film and a base film.

[0025] Sealant Film structure The expression "sealant film" refers to a film that includes a sealing layer, which is a layer that promotes adhesion to another film, layer, or article.

[0026] The sealant film according to the present invention comprises or consists of a plurality of layers and at least an outer layer O, a core layer C, and an inner layer I. The core layer C is the outer layer, i.e., located between the outer layer O and the inner layer I. The inner layer I is the sealing layer of the sealant film.

[0027] In one embodiment, the sealant film consists of an outer layer O, a core layer C, and an inner layer I. In another embodiment, the sealant film comprises one or more additional intermediate (or subskin) layers X.

[0028] In certain embodiments, the sealant film further comprises one or more intermediate layers X between the core layer C and the inner layer I, and between the core layer C and the outer layer O, for example in a five-layer film structure O / X1 / C / X2 / I or a seven-layer film structure O / X1 / X1 / C / X2 / X2 / I. Preferably, the sealant film comprises up to 9 layers, more preferably up to 7 layers.

[0029] When present, the intermediate layer X preferably comprises or consists of a composition similar to that of the adjacent layer, and thus its composition may be that of the core layer C, or of the components adjacent to the inner layer I or adjacent to the outer layer O.

[0030] Preferably, the sealant film has a thickness of 35 to 120 μm, more preferably 40 to 110 μm, and most preferably 40 to 100 μm.

[0031] In the sealant film, the core layer C preferably has a thickness of 30 to 80%, more preferably 35 to 75%, and most preferably 40 to 70% of the total thickness of the sealant film.

[0032] The outer layer O and / or the inner layer I each preferably has a thickness of 10 to 35%, more preferably 15 to 30%, of the total thickness of the sealant film. In the five-layer film structure O / X1 / C / X2 / I, the inner layer I and / or the outer layer O each preferably has a thickness of 5 to 20%, more preferably 7.5 to 15%, of the total thickness of the sealant film.

[0033] The sealant film is a "polyethylene film", i.e. a film comprising or consisting of at least one type of ethylene polymer, which may be a homopolymer or copolymer of ethylene. Preferably, the polyethylene film comprises at least 90% by weight, more preferably at least 95% by weight, most preferably at least 98% by weight, based on the total weight of the polyethylene film. Preferably, the polyethylene film comprises 90-100% by weight, more preferably 95-100% by weight, most preferably 98-100% by weight, based on the total weight of the polyethylene film. Most preferably, the polyethylene film consists only of ethylene polymer. Preferably, the ethylene polymer comprises or consists of an ethylene homopolymer and / or a copolymer of ethylene and propylene and / or any α-olefin having 4-10 carbon atoms. Preferably, the polyethylene film does not comprise a non-polyolefin polymer, more preferably does not comprise a non-polyethylene polymer. Particularly preferably, the polyethylene film does not comprise a polyester or polyamide polymer.

[0034] In general, sealant films may be provided as oriented or non-oriented films. Oriented films are films that have been "stretched" after their manufacture. Oriented films are typically stretched in the machine direction (MD) and / or transverse direction (TD) by more than 300%, preferably 500% or more. Films stretched in the machine direction are often called "MDO" films. Films stretched in two directions are called "biaxially oriented polyethylene" ("BOPE") films. Non-oriented films are blown or cast films that are not intentionally stretched (preferably more than 200%) after film manufacture by any suitable means, i.e., by subsequent heating and / or by the use of rollers during film manufacture.

[0035] Preferably, the sealant film is a non-oriented film. Preferably, the sealant film is produced on a standard blown and / or cast film line through a standard film machine system (nip rollers or take-off rollers and winder) without using any stretching unit.

[0036] As understood in the sense of the present disclosure, the sealant film and its respective layer compositions for layer preparation may also contain additives such as stabilizers, processing aids and / or pigments. Examples of such additives are antioxidants, UV stabilizers, acid scavengers, nucleating agents, antiblocking agents, slip agents, etc., as well as polymer processing agents (PPAs). The additives can be present in the same or different contents in some or only one layer of the film. The additives may be added to the respective layer compositions during the preparation of the compositions, or may already be included in any of the polymers used to prepare the respective layer compositions.

[0037] Generally, each additive may be present in an amount of 0 to 5000 ppm based on the total weight of each layer composition used to prepare the layer of the film. Additives are generally available from a number of suppliers and are included in the composition as a single additive or as a mixture of two or more additives. Such compositions may generally be present in the layer composition in an amount of 0 to 5 wt %, based on the weight of each layer composition used to prepare the layer of the film.

[0038] Generally, within the meaning of the present disclosure, percentages (%) are understood as percentages by weight (wt %), unless otherwise indicated.

[0039] composition Each sealant film layer is made of a composition that includes at least one polymer (e.g., polyethylene) component. When the composition includes more than one polymer component, it is a blend of these components. Additional compounds (polymer processing aids, additives such as antiblock agents or slip agents, etc.) may be present in the composition.

[0040] Inner Layer I The inner layer I is made of an inner layer composition that contains ingredients that contribute, among other things, to the heat sealability and optical properties of the film. The inner layer I of the sealant film is usually the sealing layer.

[0041] Ingredient AI The inner layer I of the sealant film is made of an inner layer composition containing component AI, which has a compressibility of 915 to 925 kg / m2 as determined by ISO 1133. 3 and MFR2 of 0.5-3.0 g / 10 min.

[0042] LLDPE is well known in the art and is produced by a catalytic polymerization process.

[0043] Preferably, component AI is a multimodal linear low density ethylene polymer, preferably a multimodal ethylene copolymer of ethylene and one or more comonomers selected from α-olefins having 4 to 10 carbon atoms, more preferably a bimodal ethylene copolymer of ethylene and one or more comonomers selected from α-olefins having 4 to 10 carbon atoms.

[0044] In a particular embodiment, component AI is a multimodal, preferably bimodal, copolymer of ethylene and two comonomers selected from α-olefins having 4 to 10 carbon atoms, preferably 1-butene and 1-hexene, i.e. a multimodal terpolymer.

[0045] Preferably, the ethylene copolymer has a specific MFR of 13 to 30. 21 / Has MFR2 and / or MWD ≤6.

[0046] Preferably, the ethylene copolymer comprises or consists of a multimodal polymer of ethylene with one or more comonomers selected from α-olefins having from 4 to 10 carbon atoms and has a specific MFR of 13 to 30. 21 / Has MFR2 and MWD ≤6.

[0047] Such multimodal ethylene copolymers are disclosed, for example, in WO 2016 / 083208.

[0048] The multimodal ethylene copolymer preferably has a MFR2 of 1.0 to 2.0 g / 10 min, particularly preferably 1.2 to 1.8 g / 10 min.

[0049] The multimodal ethylene copolymer preferably has a viscosity of 915 to 925 kg / m 3 and preferably 916 to 920 kg / m 3 has a density of

[0050] The multimodal ethylene copolymer preferably has a specific MFR of 13 to 30, more preferably 15 to 25. 21 / Has MFR2.

[0051] Multimodal ethylene copolymers preferably have an MWD of 6 or less, usually greater than 1, more preferably 3-5.

[0052] The α-olefin comonomers having 4 to 10 carbon atoms of the multimodal ethylene copolymers are preferably 1-butene and / or 1-hexene.

[0053] Preferably, the total amount of comonomers present in the multimodal ethylene copolymer is from 0.5 to 10 mol %, preferably from 1 to 8 mol %, more preferably from 1 to 5 mol %, even more preferably from 1.5 to 5 mol %, and most preferably from 2.5 to 4 mol %.

[0054] In a preferred embodiment, the multimodal ethylene copolymer is a bimodal copolymer, i.e., comprising a low molecular weight component and a high molecular weight component, and has a MFR2 of 1.2 to 1.8 g / 10 min, and / or a MFR5 of 3.0 to 5.0 g / 10 min, and / or a MFR of 20 to 40 g / 10 min. 21 , and / or density is 916-920 kg / m 3 , and / or a molecular weight distribution (MWD) of 3 to 5, and / or M n is 15-25 kg / mol, and / or M w is 80-115 kg / mol, and / or MFR 21 / MFR2 ratio (FRR 21 / 2 ) is between 15 and 25, and / or MFR 21 / MFR5 ratio (FRR 21 / 5 ) is 6 to 9.

[0055] In a further preferred embodiment, component AI comprises or consists of a multimodal ethylene terpolymer.

[0056] Preferably, the multimodal ethylene terpolymer has a viscosity of 915 kg / m 3 from 925kg / m 3 and MFR2 of 0.5-2.0 g / 10 min.

[0057] The multimodal ethylene terpolymer preferably comprises or consists of a multimodal polymer of ethylene and at least two different comonomers selected from α-olefins having 4 to 10 carbon atoms, the ratio MFR 21 / MFR2 is 13-30 and MWD is less than 5.

[0058] Such multimodal ethylene terpolymers are disclosed, for example, in WO 2016 / 083208. For the definition of these ethylene terpolymers (e.g., the "modality" of the polymer) and the method of production, see WO 2016 / 083208. In addition, the viscosity of the ethylene terpolymers is preferably within the range of 915 to 925 kg / m 3 All embodiments and preferred embodiments of ethylene terpolymers as described in WO 2016 / 083208 having a density in the range of 0.1 to 1.0 MPa are also preferred embodiments of multimodal ethylene terpolymers in this disclosure, whether or not explicitly described herein.

[0059] The multimodal ethylene terpolymer preferably has a MFR2 of 0.6 to 2.0 g / 10 min, particularly preferably 1.2 to 1.8 g / 10 min.

[0060] Preferably, the multimodal ethylene terpolymer has a viscosity of 915 to 925 kg / m 3 , more preferably 916 to 920 kg / m 3 has a density of

[0061] The multimodal ethylene terpolymer preferably has a specific MFR of 13 to 30, more preferably 15 to 25. 21 / Has MFR2.

[0062] The at least two α-olefin comonomers having 4 to 10 carbon atoms of the multimodal ethylene terpolymer are preferably 1-butene and 1-hexene.

[0063] Preferably, the total amount of comonomers present in the multimodal ethylene terpolymer is from 0.5 to 10 mol %, more preferably from 1 to 8 mol %, even more preferably from 1 to 5 mol %, still more preferably from 1.5 to 5 mol %, and most preferably from 2.5 to 4 mol %.

[0064] The multimodal ethylene terpolymer, which is preferably a bimodal terpolymer, preferably comprises or consists of an ethylene polymer component (A) and an ethylene polymer component (B), where the ethylene polymer component (A) has a higher MFR2 than the ethylene polymer component (B).

[0065] Preferably, the ethylene polymer component (A) has a MFR2 of from 1 to 50 g / 10 min, more preferably from 1 to 40 g / 10 min, even more preferably from 1 to 30 g / 10 min, still more preferably from 2 to 20 g / 10 min, even more preferably from 2 to 15 g / 10 min, and most preferably from 2 to 10 g / 10 min.

[0066] The ratio of MFR2 of the ethylene polymer component (A) to MFR2 of the ethylene polymer component (B) is 2-50, preferably 5-40, more preferably 10-30, further preferably 10-25, and most preferably 11-25.

[0067] Preferably, the ethylene polymer component (A) contains a different comonomer than the ethylene polymer component (B).

[0068] Preferably, the ethylene polymer component (A) has a lower comonomer amount (mol %) than the ethylene polymer component (B), and more preferably the ratio of the amount (mol %) of the α-olefin comonomer having a comonomer having from 4 to 10 carbon atoms present in the ethylene polymer component (A) to the amount (mol %) of the at least two α-olefin comonomers having from 4 to 10 carbon atoms in the final multimodal ethylene terpolymer is from 0.10 to 0.60, preferably from 0.15 to 0.50.

[0069] Preferably, the α-olefin comonomer having 4 to 10 carbon atoms of the ethylene polymer component (A) is 1-butene and the α-olefin comonomer having 4 to 10 carbon atoms of the ethylene polymer component (B) is 1-hexene.

[0070] Preferably, the ethylene polymer component (A) has a density different from, and preferably higher than, the density of the ethylene polymer component (B).

[0071] The density of the ethylene polymer component (A) is preferably 925 to 950 kg / m 3 , more preferably 930 to 945 kg / m 3 It is.

[0072] Preferably, the multimodal ethylene terpolymer comprises ethylene polymer component (A) in an amount of 30-70 wt%, more preferably 40-60 wt%, even more preferably 35-50 wt%, and still more preferably 40-50 wt%, and ethylene polymer component (B) in an amount of 70-30 wt%, more preferably 60-40 wt%, even more preferably 50-65 wt%, and still more preferably 50-60 wt%, based on the total amount (100 wt%) of the multimodal ethylene terpolymer.

[0073] Most preferably, the multimodal ethylene terpolymer comprises the ethylene polymer components (A) and (B) as the sole polymer components. Thus, the ratio of the ethylene polymer component (A1) to the ethylene polymer component (B1) is (30-70):(70-30), preferably (40-60):(60-40), more preferably (35-50):(65-50), and even more preferably (40-50):(50-60).

[0074] In a preferred embodiment, the multimodal ethylene terpolymer has an MFR2 between 1.0 and 2.0 g / 10 min and / or has a molecular weight distribution (MWD) between 3.0 and 5.0 and / or is a multimodal terpolymer of ethylene and two comonomers selected from an α-olefin having 4 to 10 carbon atoms, preferably 1-butene and 1-hexene.

[0075] In a further preferred embodiment, the multimodal ethylene terpolymer is a bimodal terpolymer comprising an ethylene polymer component (A) and an ethylene polymer component (B), wherein the ethylene polymer component (A) has a higher MFR2 than the ethylene polymer component (B), the ethylene polymer component (A) being a copolymer of ethylene and 1-butene and the ethylene polymer component (B) being a copolymer of ethylene and 1-hexene, preferably the total comonomer content in the multimodal ethylene terpolymer is 1-5 mol%.

[0076] In a particularly preferred embodiment, the multimodal ethylene terpolymer is a bimodal terpolymer, i.e., comprising a low molecular weight component and a high molecular weight component, and has a MFR2 of 1.2 to 1.8 g / 10 min, and / or a MFR5 of 3.0 to 5.0 g / 10 min, and / or a MFR of 20 to 40 g / 10 min. 21 , and / or 916-920 kg / m 3 and / or a molecular weight distribution (MWD) between 3.0 and 5.0, and / or a M between 15 and 25 kg / mol. n , and / or M between 80 and 115 kg / mol w , and / or MFR between 15 and 25 21 / MFR2 ratio (FRR 21 / 2 ), and / or MFR of 6-9 21 / MFR5 ratio (FRR 21 / 5 ).

[0077] For all polymers described herein, all molecular weight parameters are measured by GPC conventional methods detailed below unless otherwise noted. Comonomer content is measured by NMR spectroscopy as further described below.

[0078] Preferred multimodal ethylene terpolymers are also commercially available products such as Anteo™ from Borealis or Borouge, in particular Anteo™ FK1828 or Anteo™ FK1820, having the properties required herein.

[0079] Component AI is present in the inner layer composition in an amount of 75 to 95 weight percent, preferably 75 to 85 weight percent, based on the total weight of the inner layer composition.

[0080] Component AI is particularly suitable for imparting a low seal initiation temperature to the sealant film while maintaining good optical properties.

[0081] Ingredient B The inner layer I composition is a low density ethylene polymer (LDPE), preferably 915 kg / m 3 The composition may further comprise a component BI having a density equal to or greater than 10 ....

[0082] LDPE is well known in the art and is usually manufactured in a high pressure process carried out in a tubular reactor or autoclave.

[0083] LDPE and its production are described, for example, in WO 2017 / 055174 (see page 9, line 29 to page 12, line 6).

[0084] Preferably, component BI is 918 to 928 kg / m 3 , more preferably 919 to 927 kg / m 3 , and most preferably 920 to 925 kg / m 3 has a density of

[0085] Preferably, ingredient BI has a MFR2 determined by ISO 1133 of 1.5 to 2.5 g / 10 min, more preferably 1.6 to 2.4 g / 10 min.

[0086] In a preferred embodiment, the MFR2 is 1.6 to 2.4 and the tensile strength is 920 to 925 kg / m 3 has a density of

[0087] In a particularly preferred embodiment, the component BI has a MFR2 of 1.6 to 2.4 and / or a MFR of 920 to 925 kg / m 3and / or MWD between 5.5 and 9, and / or M between 12 and 18 kg / mol n , and / or M between 80 and 130 kg / mol w All molecular weight parameters are determined by GPC viscosimetry with standard calibrations, as described in more detail below.

[0088] As component BI the resins FT6230 or FT6236 from Borealis or Borouge may be used.

[0089] Component BI is preferably present in the inner layer composition in an amount of 5 to 25 weight percent, more preferably 15 to 25 weight percent, based on the total weight of the inner layer composition.

[0090] In one embodiment, the inner layer composition consists of components AI and BI in any of the embodiments described above.

[0091] Additives The inner layer composition may include additives as described above.

[0092] In certain embodiments, the inner layer composition includes a slip agent, preferably in an amount of 50-5000 ppm, and / or an antiblock agent, preferably in an amount of 50-5000 ppm, each amount based on the total weight of the inner layer composition.

[0093] Preferably, the slip agent comprises a compound selected from the group consisting of fatty acid amides such as erucamide, oleamide or stearamide, and combinations thereof.

[0094] Preferably, the anti-blocking agent comprises a compound selected from the group consisting of inorganic compounds such as talc, kaolin, cristobalite, natural and synthetic silica, diatomaceous earth, mica, calcium carbonate, calcium sulfate, magnesium carbonate, magnesium sulfate, and feldspar, and combinations thereof.

[0095] The described additives may further improve the properties of the inner layer composition.

[0096] Core layer C The core layer C of the sealant film is generally made of a core layer composition that includes components that contribute to the film's stiffness, dart impact and other mechanical properties such as tear resistance, among others. However, by using a polyester-based substrate, the demands on the sealant film in terms of mechanical properties such as stiffness are lowered.

[0097] Component AC The core layer composition may include Component AC. Preferably, Component AC is a linear low density ethylene polymer (LLDPE).

[0098] Preferably, component AC is a multimodal linear low density ethylene polymer, more preferably a multimodal, e.g. bimodal, linear low density ethylene copolymer of ethylene and a comonomer selected from α-olefins having from 4 to 10 carbon atoms. More preferably, component AC is a copolymer of ethylene and 1-butene or 1-hexene, most preferably 1-butene.

[0099] Preferably, component AC is 915 to 925 kg / m 3 and an MFR2 of 0.2 to 2.0 g / 10 min, as determined by ISO 1133.

[0100] Such multimodal LLDPE and its preparation are described, for example, in WO 2004 / 000933 A1 (see pages 9-12) and WO 2021 / 013552.

[0101] In the first embodiment, the component AC is 918 to 925 kg / m 3 , more preferably 920 to 925 kg / m 3 and MFR2 of 0.2 to 0.5 g / 10 min, more preferably 0.2 to 0.4 g / 10 min.

[0102] Preferably, the total amount of comonomers present in component AC of the first embodiment is from 2.0 to 6.0 mol %, more preferably from 2.5 to 5.5 mol %, and most preferably from 3.0 to 5.2 mol %.

[0103] In a particularly preferred embodiment of the first aspect, component AC is a multimodal linear low density ethylene polymer, more preferably a bimodal linear low density ethylene copolymer of ethylene and a comonomer selected from an α-olefin having 4 to 10 carbon atoms, most preferably 1-butene, having a MFR2 of 0.2 to 0.4 g / 10 min, and / or a MFR5 of 0.8 to 1.2 g / 10 min, and / or a MFR of 18 to 26 g / 10 min. 21 , and / or 920-925 kg / m 3 and / or a molecular weight distribution (MWD) between 10 and 20, and / or a M between 10 and 15 kg / mol n , and / or M between 150 and 250 kg / mol w , and / or MFR between 80 and 110 21 / MFR2 ratio (FRR 21 / 2 ), and / or MFR of 18-26 21 / MFR5 ratio (FRR 21 / 5 ).

[0104] In a second embodiment, the component AC is 915 to 920 kg / m 3 , more preferably 916 to 920 kg / m 3 and MFR2 of 0.8 to 2.0 g / 10 min, more preferably 0.8 to 1.5 g / 10 min.

[0105] Preferably, the total amount of comonomers present in component AC of the second aspect is from 7.0% to 13.0% by weight, preferably from 7.3% to 12.0% by weight, more preferably from 7.5% to 11.5% by weight, and most preferably from 7.7% to 11.0% by weight, based on the total weight of monomer units in component AC.

[0106] Preferably, component AC of the second embodiment comprises or consists of two ethylene-1-butene copolymer fractions (A1) and (B1), where the first ethylene-1-butene copolymer fraction (A1) has a higher MFR2 than the second ethylene-1-butene copolymer fraction (B1).

[0107] The first ethylene-1-butene copolymer fraction (A1) has a 1-butene content of 0.5 wt.% to 7.5 wt.%, preferably 0.6 wt.% to 5.0 wt.%, even more preferably 0.7 wt.% to 3.5 wt.%, and most preferably 0.8 wt.% to 3.0 wt.%, based on the total weight of monomer units in the first ethylene-1-butene copolymer fraction (A1).

[0108] The first ethylene-1-butene copolymer fraction (A1) preferably has a viscosity of 915 kg / m 3 ~955kg / m 3 , more preferably 925 kg / m 3 ~950kg / m 3 , most preferably 935 kg / m 3 ~945kg / m 3 has a density of

[0109] The first ethylene-1-butene copolymer fraction (A1) preferably consists of ethylene and 1-butene monomer units.

[0110] The first ethylene-1-butene copolymer fraction (A1) has a melt flow rate MFR2 of from 1.0 g / 10 min to less than 50.0 g / 10 min, preferably from 2.0 g / 10 min to 45.0 g / 10 min, even more preferably from 3.0 g / 10 min to 30.0 g / 10 min, even more preferably from 3.5 g / 10 min to 20.0 g / 10 min, and most preferably from 4.0 g / 10 min to 10.0 g / 10 min.

[0111] The first ethylene-1-butene copolymer fraction (A1) preferably has a higher melt flow rate MFR2 than the second ethylene-1-butene copolymer fraction (B1). It is further preferred that the first ethylene-1-butene copolymer fraction (A1) has a higher melt flow rate MFR2 than component AC.

[0112] A higher MFR2 value of the first ethylene-1-butene copolymer fraction (A1) may be indicative of a lower molecular weight of the first ethylene-1-butene copolymer fraction (A1), e.g., a lower weight average molecular weight M w indicates that is lower.

[0113] The first ethylene-1-butene copolymer fraction (A1) is preferably present in component AC in an amount of 30 to 47% by weight, more preferably 32 to 46% by weight, and most preferably 35 to 45% by weight, based on the total weight of component AC.

[0114] The first ethylene-1-butene copolymer fraction (A1) is usually polymerized as the first polymer fraction in a multi-stage polymerization process having two or more polymerization stages in sequence, and therefore the properties of the first ethylene-1-butene copolymer fraction (A1) can be measured directly.

[0115] The second ethylene-1-butene copolymer fraction (B1) has a 1-butene content of 10.0 wt.% to 25.0 wt.%, preferably 12.5 wt.% to 22.0 wt.%, more preferably 15.0 wt.% to 21.0 wt.%, and most preferably 16.0 wt.% to 20.0 wt.%, based on the total weight of monomer units in the second ethylene-1-butene copolymer fraction (B1).

[0116] The second ethylene-1-butene copolymer fraction (B1) preferably has a melting point of 870 kg / m 3 ~912kg / m 3 , more preferably 880 kg / m 3 ~910kg / m 3, most preferably 890 kg / m 3 ~905kg / m 3 has a density of

[0117] The second ethylene-1-butene copolymer fraction (B1) preferably consists of ethylene and 1-butene monomer units.

[0118] The second ethylene-1-butene copolymer fraction (B1) has a melt flow rate MFR2 of 0.05 g / 10 min to less than 1.0 g / 10 min, preferably 0.1 g / 10 min to 0.8 g / 10 min, more preferably 0.2 g / 10 min to 0.7 g / 10 min, and most preferably 0.3 g / 10 min to 0.6 g / 10 min.

[0119] It is further preferred that the second ethylene-1-butene copolymer fraction (B1) has a lower melt flow rate MFR2 as component AC.

[0120] The lower MFR2 value of the second ethylene-1-butene copolymer fraction (B1) may correspond to a higher molecular weight, e.g. a higher weight average molecular weight M, of the second ethylene-1-butene copolymer fraction (B1) compared to the first ethylene-1-butene copolymer fraction (A1) and / or component AC. w Shows.

[0121] The second ethylene-1-butene copolymer fraction (B1) is usually polymerized in a multi-stage polymerization process having two or more polymerization stages in sequence as a second polymer fraction in the presence of the first ethylene-1-butene copolymer fraction (A1). As a result, the properties of the second ethylene-1-butene copolymer fraction (B1) cannot be measured directly and must be calculated. Suitable methods for calculating the comonomer content, density and MFR2 of the second ethylene-1-butene copolymer fraction (B1) are described in WO 2021 / 013552.

[0122] The second ethylene-1-butene copolymer fraction (B1) is preferably present in component AC in an amount of 43 to 65% by weight, more preferably 44 to 62% by weight, most preferably 45 to 60% by weight, based on the total weight of component AC.

[0123] The weight ratio of the first ethylene-1-butene copolymer fraction (A1) to the second ethylene-1-butene copolymer fraction (B1) in component AC is preferably 35:65 to 47:53, more preferably 37:63 to 46:54, and most preferably 40:60 to 45:55.

[0124] In one preferred embodiment of the invention, component AC consists of a first ethylene-1-butene copolymer fraction (A1) and a second ethylene-1-butene copolymer fraction (B1).

[0125] In a particularly preferred embodiment of the second aspect, component AC is a multimodal linear low density ethylene polymer, more preferably a bimodal linear low density ethylene copolymer of ethylene and a comonomer selected from an α-olefin having 4 to 10 carbon atoms, most preferably 1-butene, comprising two ethylene-1-butene copolymer fractions (A1) and (B1) and having a MFR2 of 0.8 to 1.5 g / 10 min and / or a MFR of 15 to 35 g / 10 min. 21 , and / or 915-920 kg / m 3 and / or MFR of 15-25 21 / MFR2 ratio (FRR 21 / 2 ).

[0126] As component AC, the resins Borstar FB2230 from Borealis or Borouge, or the resins Anbiq® FM1810 or FM1818 from Borouge may be used.

[0127] Preferably, component AC is present in the core layer composition in an amount of 50 to 90 weight percent, more preferably 60 to 85 weight percent, based on the total weight of the core layer composition.

[0128] Ingredient BC The core layer composition may include component BC which is a low density ethylene polymer (LDPE). Preferably, component BC is an LDPE as described for component BI of the inner layer composition, preferably having a density of 918 to 928 kg / m 3 and / or has a MFR2 of 1.5 to 2.5 g / 10 min, as determined by ISO 1133.

[0129] All embodiments described for component BI are also embodiments for component BC. Component BC may be independently selected from any one of these embodiments, and the selected embodiments may be the same or different for BC and BI.

[0130] Preferably, component BC is present in the core layer composition in an amount of from 10 to 40 weight percent, more preferably from 15 to 25 weight percent, based on the total weight of the core layer composition.

[0131] In one embodiment, the core layer composition comprises or consists of components AC and BC in any of the embodiments described above.

[0132] In a preferred embodiment, the core layer composition comprises or consists of component AC in an amount of 50 to 90 wt. %, and component BC in an amount of 10 to 40 wt. %, based on the total weight of the core layer composition.

[0133] The core layer composition may include additional ethylene polymer components, such as other LLDPEs and LDPEs.

[0134] outer layer O The outer layer O of the sealant film is made from an outer layer composition that includes one or more components. In a laminate film, the outer layer O may be disposed between the core layer C and the substrate film, and contributes to the mechanical and optical properties of the film.

[0135] Ingredient AO The outer layer composition may include component AO, preferably a linear low density ethylene polymer (LLDPE), as described for component AC of the core layer composition.

[0136] All the aspects described for component AC are also aspects of component AO. Component AO may be independently selected from any one of these aspects, and the selected aspects may be the same or different for AO and AC.

[0137] Preferably, component AO is present in the outer layer composition in an amount of from 50 to 90 weight percent, more preferably from 60 to 85 weight percent, based on the total weight of the outer layer composition.

[0138] Ingredient BO The outer layer composition may include component BO, which is a low density ethylene polymer (LDPE). Preferably, component BO is an LDPE as described for component BI of the inner layer composition, preferably having a viscosity of 918 to 928 kg / m 3 and / or MFR2, as determined by ISO 1133, of 1.5 to 2.5 g / 10 min.

[0139] All the aspects described for component BI are aspects for component BO. Component BO may be independently selected from any one of these aspects, and the selected aspects may be the same or different for BO and BI.

[0140] Preferably, component BO is present in the outer layer composition in an amount of from 10 to 40 weight percent, more preferably from 15 to 25 weight percent, based on the total weight of the outer layer composition.

[0141] In one embodiment, the outer layer composition comprises or consists of components AO and BO in any of the embodiments described above.

[0142] In a preferred embodiment, the outer layer composition comprises or consists of component AO in an amount of 50 to 90 weight percent, and component BO in an amount of 10 to 40 weight percent, based on the total weight of the outer layer composition.

[0143] The outer layer composition may include additional ethylene polymer components, such as other LLDPEs and LDPEs.

[0144] In certain embodiments, the core layer composition and the outer layer composition contain the same ingredients, optionally in the same amounts.

[0145] In a preferred embodiment, the polyethylene sealant film has a compressibility of 915 to 925 kg / m 3 and 5-30% by weight of a low density ethylene polymer (LDPE), both weight percentages being based on the total weight of the polyethylene sealant film. These properties can be achieved by using the above ethylene polymers in each layer, with additional ethylene polymers having the required properties present as needed.

[0146] characteristics The sealant film exhibits excellent sealing behavior with lower seal initiation and hot tack temperatures (e.g., seal initiation temperature of less than 95° C. for a single sealant film, i.e., before lamination). These properties can be achieved by using component AI in the inner layer of the sealant film and can be further improved by the presence of component BI.

[0147] The mechanical and optical properties of the sealant film are in a range that is well suited for use as a sealant film for laminate construction in packaging applications.

[0148] Preferably, the sealant film (before lamination) has a seal initiation temperature at 5N (SIT) of less than 100° C., preferably less than 95° C., for example less than 92° C., when measured at the inner layer I of the sealant film. Preferably, the sealant film (before lamination) has a seal initiation temperature at 5N (SIT) of 80 to 100° C., preferably 85 to 95° C., when measured at the inner layer I of the sealant film. The seal initiation temperature at 5N (SIT) is determined according to ASTM F 2029 and ASTM F 88.

[0149] Preferably, the sealant film (before lamination) has a hot tack temperature at 1N of less than 95° C., preferably less than 90° C., when measured at inner layer I of the sealant film. Preferably, the sealant film (before lamination) has a hot tack temperature at 1N of 80-95° C., preferably 82-90° C., when measured at inner layer I of the sealant film. The hot tack temperature at 1N is determined by ASTM F1921.

[0150] Preferably, the sealant film (before lamination) has a haze value of less than 14%, more preferably less than 12%. Preferably, the sealant film (before lamination) has a haze value of 3 to 14%, most preferably 5 to 12%. The haze value is determined by ASTM D1003 as a measure of the transparency of the film, and this value indicates good transparency.

[0151] Preferably, the sealant film (before lamination) has a dart impact (DDI) of at least 200 g, more preferably at least 250 g. Preferably, the sealant film (before lamination) has a dart impact (DDI) of 200-600 g, more preferably 250-500 g. The dart impact (DDI) is determined according to ASTM D1709 "Method A" on a sealant film having a thickness of preferably 35-120 μm, more preferably 40-110 μm, most preferably 40-100 μm.

[0152] Preferably, the sealant film (before lamination) has a coefficient of friction less than 0.50, more preferably less than 0.40. Preferably, the sealant film (before lamination) has a coefficient of friction of 0.05 to 0.50, more preferably 0.10 to 0.40. The coefficient of friction is determined by ISO 8295 under dynamic conditions (in / in or out / out).

[0153] preparation The sealant films are generally prepared by conventional processes for the preparation of multilayer films, where the layers of the film are coextruded.

[0154] The different polymeric components contained in any layer of the film are usually thoroughly mixed prior to layer formation, for example using a twin-screw extruder, preferably a counter-rotating or co-rotating extruder, and the mixture is then converted into a coextruded film.

[0155] Films can be produced by blown film or cast film processes. To produce such multilayer films, for example, at least two polymer melt streams are typically extruded simultaneously (i.e., coextruded) through a multi-channel tubular, annular, or circular die to form a tube, which is then blown with air (or a combination of gases) to expand and / or cool to form the film. The production of blown films is well known.

[0156] Blow (co)extrusion can be carried out at a temperature ranging from 150°C to 230°C, more preferably from 160°C to 225°C, and cooled with blow gas (generally air) at a temperature of 10-40°C, more preferably from 12-16°C, to provide a frost line height of 0.5-4 times, more preferably 1-2 times the die diameter.

[0157] The blow-up ratio (BUR) is generally in the range of 1.5 to 3.5, preferably 2.0 to 3.0, and more preferably 2.1 to 2.8.

[0158] Since the sealant film is preferably a non-oriented film, it is preferable not to carry out a stretching step for orientation.

[0159] Base Film The phrase "substrate film" refers to a film that contributes to the mechanical properties, heat resistance, and optical properties of the laminate film.

[0160] The substrate film comprises or consists of a polyester polymer selected from the group consisting of polyethylene terephthalate (PET), polybutylene terephthalate (PBT) and polytrimethylene terephthalate (PTT), and mixtures thereof; preferably, the polyester polymer comprises or consists of polyethylene terephthalate (PET).

[0161] As the substrate film of the laminate film of the present invention, any PET, PBT and PTT films known in the art may be used.

[0162] Such polyester-based films generally contribute film stiffness, heat resistance, puncture resistance, and / or barrier properties to the laminate film.

[0163] In a preferred embodiment, the substrate film is a polyethylene terephthalate (PET) film, i.e., consists essentially of (i.e., at least 95% by weight, more preferably up to 97% by weight) polyethylene terephthalate and optional additives used in the PET polymer.

[0164] In general, polyester-based polymers optionally contain additives that are commonly used to improve slip and anti-friction properties. Such additives are, for example, inorganic pigments such as CaCO3, SiO2, kaolin, BaSO4 and TiO2, or crosslinked organic polymer particles. Additional commonly used additives such as nucleating agents, antioxidants, antistatic agents, heat stabilizers, UV-blocking or UV-absorbing additives, flame retardant additives, waxes and dyes may also be added as known in the art.

[0165] Polyester-based films are generally produced by extrusion. The molten polyester material is extruded through a flat film extrusion die and cooled on a chill roll as an amorphous prefilm. The film is then reheated and stretched in the longitudinal and transverse directions, or in the transverse and longitudinal directions, or in the longitudinal, transverse and again longitudinal directions. The stretching temperature is generally 100-130°C. The draw ratio of the longitudinal stretching is about 2-6, preferably 3-4.5. The draw ratio of the transverse stretching is about 2-5, especially 3-4. If necessary, the draw ratio of the second longitudinal stretching may be about 1.1-3. The first longitudinal stretching may be carried out simultaneously with the transverse stretching (simultaneous stretching) if necessary. After stretching, the film is heat-set at 150-240°C, especially 180-220°C, to significantly reduce the tendency of the film to shrink.

[0166] The substrate film may be a non-oriented film or an oriented film. Particularly preferred are oriented substrate films such as oriented PET films, for example biaxially oriented PET films ("BOPET").

[0167] The substrate film may be constructed of one or more layers, each layer comprising a polyester polymer, differing essentially only in additives. Multilayer films are generally produced by lamination, preferably by coextrusion. Layering offers the advantage, among other things, that the various additives used contribute to the film in the required way.

[0168] The substrate film may comprise one or more layers, however, a single layer substrate film is preferred.

[0169] The surface properties and surface roughness can be influenced, inter alia, by selectively additionally coating the substrate film with a solution or dispersion containing crosslinkable, curable, or already crosslinked or cured substances or particles, as known in the art. The coating is preferably carried out using an in-line coating process, i.e., coating the film during the stretching step or after orientation.

[0170] Selective surface modification of polyester-based films using electrical corona discharge may be carried out after the film is completed, i.e., after heat curing, by methods known in the art.

[0171] Substrate films of different thicknesses may be used, but preferred substrate films have a thickness of 10 to 25 μm, preferably 10 to 20 μm.

[0172] PET, PBT and PTT films are commercially available from several suppliers, such as brand name films of Sarafil® PET films (Polyplex), Melinex® and Mylar® PET films (Tekra), or Hostaphan® PET films (Mitsubishi Polyester Film). Films may be prepared as described above from the respective polymers commercially available from companies such as BASF, DuPont, Lanxess, Sinopec, RTP Company, and others.

[0173] Laminate Film Structure and preparation Generally, a laminate film refers to a multi-layer structure including multiple films and / or layers. In the present invention, the laminate film includes or consists of the sealant film and the base film of any of the above-mentioned embodiments laminated together.

[0174] In the laminate film, the base film and the sealant film are connected through the outer layer O of the sealant film and the layer of the base film, respectively. The inner layer I of the sealant film forms the inner layer of the laminate film and is used as the sealing layer of the laminate film. The base film forms or contains the outer layer of the laminate film, respectively.

[0175] The connection, i.e., lamination of the substrate and sealant film to each other, can be effected by conventional lamination equipment using any conventional lamination method, such as adhesive lamination, including both solvent-based and solventless adhesive lamination using conventional commercially available adhesives. The adhesive may be applied to the sealant film and / or substrate film by any suitable method. For example, methods may include the use of a laminator, gravure coating, roll coating, wire rod coating, spray coating, and the like. The film surface for applying the adhesive may be corona treated to increase the surface energy and provide sufficient wettability for the adhesive components.

[0176] The lamination may alternatively be performed as a sandwich lamination, with or without a melt web, which may be pressed between the films without any adhesive. Such a melt web may be any conventional melt web material based on polyethylene, such as LDPE. The lamination may also be performed by extrusion coating techniques. All these lamination methods are well known in the art and described in the literature.

[0177] Preferably, the lamination is performed using an adhesive, such as a solventless adhesive, which may form a layer between the sealant and the substrate film.

[0178] Preferably, the adhesive has a weight per square meter of 1.0 g / m 2 ~3.5g / m 2 , more preferably 1.2 g / m 2 ~2.5g / m 2 It is.

[0179] Preferably, the adhesive (or adhesive layer) comprises less than 5% by weight of the total weight of the laminate film. The percentage of adhesive usually depends on the total weight of the laminate film, which correlates with the thickness of the laminate film. For example, a laminate film of about 75 μm preferably comprises a maximum of 4% by weight of adhesive based on the total weight of the laminate film, while a laminate film of about 130 μm preferably comprises a maximum of 3% by weight of adhesive based on the total weight of the laminate film.

[0180] Preferably, the laminate film has a thickness of 45 to 150 μm, more preferably 50 to 140 μm, and most preferably 50 to 120 μm.

[0181] Preferably, the laminate film consists of a sealant film, a substrate film, and optionally an adhesive layer between the polyethylene sealant film and the substrate film.

[0182] Preferably, the laminate film does not contain any further polymers other than those of the sealant film, the substrate film and, optionally, the adhesive layer, with the exception of polymer additives commonly used in the art.

[0183] The simple structure of the laminate film and the absence of various types of polymers allow the laminate film to be recycled more efficiently.

[0184] characteristics The laminate film according to the present invention is characterized by excellent sealing properties. These properties are imparted by the sealant film, which contains a specific inner layer composition. The LLDPE used in the inner layer composition has a strength of 915 to 925 kg / m 3 (a specific example is 918 kg / m 3100°C at 5N for the inner layer of the laminate film. As shown in the Examples section, the inventive example IE2 reached a seal initiation temperature of 95.1°C. Compared to other examples using LLDPE of the same density (i.e. CE5 and CE7), the inventive examples had a seal initiation temperature that was at least 5°C lower. 3 or 914 kg / m 3 Only the very low LLDPEs (CE4 and CE3) showed relatively low seal initiation temperatures. However, low density LLDPEs usually suffer from drawbacks such as stickiness.

[0185] Drawing comparisons between sealant films, it can be seen that the sealant film used in the laminate film of the present invention exhibits superior seal initiation temperature over all comparative examples (IE1 vs. CE1-CE4).

[0186] Therefore, the laminate film has a seal initiation temperature at 5N (SIT) of less than 100° C., preferably less than 99° C., more preferably less than 98° C., when measured on the inner surface of the laminate film. Preferably, the laminate film has a seal initiation temperature at 5N (SIT) of 85 to 100° C., preferably 90 to 99° C., when measured on the inner surface (inner layer I) of the laminate film. The seal initiation temperature at 5N (SIT) is determined according to ASTM F 2029 and ASTM F 88.

[0187] In a particular embodiment, the seal initiation temperature SIT(5N) of the laminate film is further determined by the following relationship (I): SIT (℃) ≦ 1.6278 × density of component AI (kg / m 3 )-1395(I) and the seal initiation temperature is determined for the inner layer of the polyethylene sealant film according to ASTM F2029, ASTM F88. This mathematical relationship (I) correlates the density of the LLDPE polymer used as component AI in the present invention with the seal initiation temperature of the laminate film. This relationship shows that when the density of the LLDPE is relatively high, the seal initiation temperature is relatively low when compared to conventional LLDPE. In Figure 4, the density of the LLDPE used in the examples is plotted against the SIT temperature of the respective laminate film. The comparative examples are based on the following relationship: SIT (°C) = 1.6278 x density of LLDPE (kg / m 3 )-1393 (shown by an approximate line), but the SIT temperature is lower for the LLDPE of the embodiment of the present invention having a relatively high density.

[0188] Preferably, the laminate film has a hot tack temperature at 1N, measured at the inner layer surface (inner layer I) of less than 98°C, preferably less than 95°C, for example less than 93.5°C, when measured at the inner layer surface (inner layer I) of the laminate film. Preferably, the laminate film has a hot tack temperature at 1N, measured at the inner layer surface (inner layer I) of 80 to 98°C, preferably 85 to 95°C, when measured at the inner layer surface (inner layer I) of the laminate film. The hot tack temperature at 1N is determined by ASTM F1921.

[0189] The laminate film according to the present invention has improved mechanical properties along with good optical properties. The good heat resistance imparted by the substrate film allows the laminate film to run smoothly on high speed VFFS equipment.

[0190] For example, tensile modulus (1% secant) is a measure of the strength properties in the elastic region of a film and represents the actual deformation at a selected point on the stress-strain curve. As a result, tensile modulus provides useful insight into the stiffness and resistance to elongation in use, or how much a film will stretch during packaging operations such as Form, Fill & Seal (FFS) machines and / or under the normal operating tensions of the package. A high tensile modulus is highly advantageous.

[0191] Preferably, the laminate film has a tensile modulus in the machine direction (MD) (1% secant modulus) of at least 900 MPa, preferably at least 1000 MPa. Preferably, the laminate film has a tensile modulus in the machine direction (MD) (1% secant modulus) of 900 MPa to 1400 MPa, preferably 1000 MPa to 1300 MPa. The tensile modulus in the machine direction (MD) (1% secant modulus) is determined according to ASTM D882.

[0192] Preferably, the laminate film has a tensile modulus in the transverse direction (TD) (1% secant modulus) of at least 800 MPa, preferably at least 900 MPa. Preferably, the laminate film has a tensile modulus in the transverse direction (TD) (1% secant modulus) of 800 MPa to 1400 MPa, preferably 900 MPa to 1300 MPa. The tensile modulus in the transverse direction (TD) (1% secant modulus) is determined according to ASTM D882.

[0193] Preferably, the laminate film has a relative tear resistance in the machine direction (MD) of 4.0 to 6.0 N / mm, more preferably 4.2 to 5.5 N / mm. Preferably, the laminate film has a relative tear resistance in the transverse direction (TD) of 4.0 to 6.0 N / mm, more preferably 4.1 to 5.5 N / mm. The relative tear strength is determined according to ISO 6383-2.

[0194] Preferably, the laminate film has a deformation at maximum force of 20 to 40 mm, and / or a maximum force of 150 to 200 N, and / or an energy to maximum force of 1.5 to 3.0 J. These parameters are determined according to ASTM D5748.

[0195] Preferably, the laminate film has a dart impact (DDI) of at least 350 g, more preferably at least 400 g. Preferably, the laminate film has a dart impact (DDI) of 350 to 700 g, more preferably 400 to 650 g. The dart impact (DDI) is determined according to ASTM D1709 "Method A" on a laminate film having a thickness of preferably 45 to 150 μm, more preferably 50 to 140 μm, most preferably 50 to 120 μm.

[0196] Preferably, the laminate film has a coefficient of friction less than 0.40, more preferably less than 0.35, when measured on the inner surface; and / or a coefficient of friction less than 0.30, more preferably less than 0.20, when measured on the outer surface. Preferably, the laminate film has a coefficient of friction between 0.10 and 0.40, more preferably between 0.15 and 0.35, when measured on the inner surface; and / or a coefficient of friction between 0.05 and 0.30, more preferably between 0.08 and 0.20, when measured on the outer surface. The coefficient of friction is determined according to ISO 8295 under dynamic conditions (in / in or out / out).

[0197] The laminate films according to the present invention exhibit very good optical properties (ie haze and gloss) and are thus well suited for packaging applications where aesthetic demands are high.

[0198] Preferably, the laminate film has a haze value of less than 12%, more preferably less than 10%. Preferably, the laminate film has a haze value of 3 to 12%, more preferably 5 to 10%. The haze value is determined by ASTM D1003 as a measure of the transparency of the film, and this value indicates good transparency.

[0199] Preferably, the laminate film has a gloss value of at least 80, more preferably at least 85. Preferably, the laminate film has a gloss value of 80 to 140, more preferably 85 to 130. The gloss value (GU) is determined at 45° according to ASTM D2457 on the inner or outer surface of the laminate film, preferably on the outer surface.

[0200] Goods and Use The present invention also relates to an article comprising a laminate film according to the present invention. Preferred articles are packaging articles, preferably flexible packaging articles, for example pouches such as stand-up pouches, sacks, bags, sachets, lamitubes and the like.

[0201] The invention further relates to the use of the laminated film according to the invention for packaging of articles, in particular for use in (mechanical) form-fill-seal packaging techniques or for forming pouches, such as stand-up pouches, sacks, bags, sachets, laminated tubes.

[0202] Specific articles and uses are heavy duty packing bags, detergent pouches and articles / uses for packaging various food items such as rice, wheat, cereals, flour, food grains, pet food etc, and non-food items such as detergent / laundry powders, building materials, chemicals and other materials.

[0203] Any one of the aspects of the invention described herein can be combined with one or more of these aspects. In particular, any aspect described for the laminate film of the invention is applicable to the use of the laminate film or article.

[0204] Furthermore, the present invention relates to the use of a polyethylene sealant film comprising an inner layer I, the inner layer I having a compressibility of 915 to 925 kg / m 3and a melt flow rate (MFR2) of 0.5 to 3.0 g / 10 min as determined by ISO 1133, wherein the weight % is based on the total weight of the inner layer composition. The present invention relates to use of a sealant film for improving the sealing performance of a base film comprising a polyester polymer selected from the group consisting of polyethylene terephthalate, polybutylene terephthalate, and polytrimethylene terephthalate, preferably polyethylene terephthalate, when laminating the sealant film onto the base film.

[0205] For specific embodiments of the inner layer composition, the polyethylene sealant film and the substrate film, please refer to the embodiments described in the relevant positions above. These embodiments are also applicable to the use of the present invention.

[0206] The invention will now be further explained by way of examples, with reference to the figures in which:

[0207] Figure 1: Comparison of heat seal initiation temperature at 5N measured on the inner layer of the sealant film before lamination and density of the LLDPE of the examples.

[0208] Figure 2: Sealing temperature curve of sealant film before lamination.

[0209] Figure 3: Hot tack temperature curves of sealant film before lamination.

[0210] Figure 4: Comparison of the seal initiation temperature at 5N measured on the inner layer of the sealant film in the laminate film and the density of the LLDPE of the examples.

[0211] Figure 5: Hot tack temperature curves of laminated films.

[0212] Measurement and determination methods The following definitions and determination methods of terms apply to the general description of the invention above as well as to the examples below, unless otherwise defined.

[0213] a) Measurement of Melt Flow Rate (MFR) Melt flow rate (MFR) is determined according to ISO 1133 and is expressed in g / 10 min. The higher the melt flow rate, the lower the viscosity of the polymer. MFR is determined for polyethylene at 190°C under a load of 2.16 kg (MFR2), 5.00 kg (MFR5) or 21.6 kg (MFR 21 ) is determined.

[0214] The quantity FRR (Flow Rate Ratio) is an index of molecular weight distribution and refers to the flow rate ratio at different loads. Thus, FRR 21 / 5 MFR 21 Refers to the / MFR5 value.

[0215] b) Density The density of the polymer is determined according to ISO 1183-1:2004 (Method A) on compression moulded specimens prepared according to ISO 17855-2 and is expressed in kg / m 3 As shown in the figure.

[0216] c) GPC 1) Conventional GPC method Molecular weight average (M z , M w , M n ), molecular weight distribution (MWD), and polydispersity index PDI=M w / M n (In the formula, M n is the number average molecular weight, M w The breadth, expressed as the weight average molecular weight, was determined by gel permeation chromatography (GPC) according to ISO 16014-1:2003, ISO 16014-2:2003, ISO 16014-4:2003 and ASTM D 6474-12 using the following formula: TIFF2025505804000001.tif17153(1) TIFF2025505804000002.tif17153(2) TIFF2025505804000003.tif17153(3)

[0217] Fixed elution interval ΔV i In the case of A i and M. i are the elution volumes V i is the chromatographic peak slice area related to the molecular weight (MW) of the polyolefin, and N is equal to the number of data points obtained from the chromatogram between the integration limits.

[0218] A high-temperature GPC instrument equipped with an infrared (IR) detector (IR4 or IR5 from PolymerChar, Valencia, Spain) or a differential refractometer (RI) from Agilent Technologies and equipped with 3x Agilent-PLgel Olexis and 1x Agilent-PLgel Olexis Guard columns was used. The mobile phase was 1,2,4-trichlorobenzene (TCB) stabilized with 250 mg / L of 2,6-ditertbutyl-4-methyl-phenol. The chromatographic system was operated at a column temperature of 160 °C, a detector temperature of 160 °C, and a constant flow rate of 1 mL / min. 200 μL of sample solution was injected per analysis. Data collection was performed using Agilent Cirrus software version 3.3 or PolymerChar GPC-IR control software.

[0219] The column set was calibrated with 19 narrow MWD polystyrene (PS) standards ranging from 0.5 kg / mol to 11,500 kg / mol. The PS standards were dissolved at room temperature for several hours. Conversion of the polystyrene peak molecular weights to polyolefin molecular weights was performed using the Mark Houwink equation and the following Mark Houwink constants: K PS =19×10 -3 mL / g,α PS =0.655 K PE =39×10 -3 mL / g,α PE =0.725

[0220] A third order polynomial fit was used to fit the calibration data.

[0221] All samples were prepared in a concentration range of approximately 1 mg / ml and dissolved for PE in freshly distilled TCB stabilized with 250 ppm Irgafos 168 at 160° C. for 3 hours with continuous gentle shaking.

[0222] 2)GPC viscosity method Molecular weight average of LDPE (M z ,M w and M. n ), the molecular weight distribution (MWD) is determined by GPC-viscosity method using universal correction. w ,M n ), molecular weight distribution (MWD), and polydispersity index PDI=M w / M n (where M n is the number average molecular weight, M w Its breadth, expressed as the weight average molecular weight (MWD), was determined by gel permeation chromatography (GPC) according to ISO16014-4:2019. A PL 220 (Polymer Laboratories) GPC equipped with an IR4 infrared detector, an online 4-capillary bridge viscometer (PL-BV 400-HT) was used. A 3× Olexis Guard column and a 1× Olexis Guard column from Polymer Laboratories were applied as stationary phase and 1,2,4-trichlorobenzene (TCB, stabilized with 250 mg / L 2,6-ditertbutyl-4-methyl-phenol) as mobile phase at 160 °C and a constant flow rate of 1 mL / min. 200 μL of sample solution were injected per analysis. A narrow PS standard with a molar mass of 132900 g / mol and an intrinsic viscosity of 0.4789 dl / g (MWD = 1.01) was used to determine the corresponding detector constant of the viscometer as well as the inter-detector delay volume. The detector constant of the IR4 detector is dn / dc = 0.094 cm using NIST1475a. 3 / g.

[0223] The column set was calibrated using universal calibration (according to ISO16014-2:2019) with at least 15 narrow MWD polystyrene (PS) standards ranging from 0.5 kg / mol to 11600 kg / mol. The corresponding intrinsic viscosities of the PS standards were calculated from their corresponding concentrations (IR4), the online viscometer signal, and the determined detector constant for polystyrene. For low molecular weight PS with molar masses below 3000 g / mol, the initial off-grain concentrations were used due to end group effects in the IR detector.

[0224] The molecular weight (M2) of the sample in each chromatographic slice using the universal calibration approach is given by the following correlation equation: logM1[η1]=V R =logM2[η2] where: molar mass of M1PS Intrinsic viscosity of η1PS M2 Molar mass of the sample η2 Intrinsic viscosity of sample V R Retention Volume It can be calculated as follows.

[0225] All data processing and calculations were performed using Cirrus Multi-Offline SEC-Software Version 3.2 (Polymer Laboratories a Varian inc.).

[0226] All samples were prepared by dissolving 5.0–9.0 mg of polymer in 8 mL of stabilized TCB (same as the mobile phase) with continuous gentle shaking at 160 °C for 2.5 h for PP and up to 3 h for PE.

[0227] d) Comonomer Content Comonomer content was determined as described in WO199081611, pages 31 to 34.

[0228] e) Mechanical properties Tensile modulus and tensile stress at break The tensile properties of the films were determined using type 2 specimens with blown films according to ISO 527-3 at 23 °C. The tensile modulus in the machine direction (MD) and transverse direction (TD) were determined as 1% secant modulus according to ASTM D882 at a test speed of 5 mm / min and a gauge length of 50 mm.

[0229] Tensile stress at break was determined using ISO 527-3 specimen type 2 with a gauge length of 50 mm and a test speed of 500 mm / min. Film samples were prepared as described in the Examples section below.

[0230] Tensile Breaking Stress Machine direction (MD) and transverse direction (TD) tensile stresses at break were determined according to ISO 527-3 for films of the indicated thicknesses produced as described in the Examples below.

[0231] Relative Tear Resistance Relative tear resistance in the machine direction (MD) and transverse direction (TD) was determined according to ISO 6383-2 for films of thickness as indicated, produced as described in the Examples below.

[0232] Breakdown resistance Puncture resistance testing according to ASTM D5748 is performed on films having thicknesses as indicated and produced as described in the Examples below. The test method determines the resistance of film samples to penetration of a probe having a specific size of a 19 mm diameter pear-shaped TFE fluorocarbon coated at a standard low speed, single test speed (250 mm / min). Performed at standard conditions, the test method imparts biaxial stress loading. Film specimens are cut to 150 mm x 150 mm to fit into a jig and conditioned at 23±2°C and 50±5% relative humidity.

[0233] This method yielded the following parameters: maximum force / fracture resistance force (N), deformation at maximum force (mm) and energy for maximum force / fracture resistance energy (J).

[0234] The breaking force (N) is the maximum or peak force observed during the test, and the breaking energy (J) is the energy used until the probe breaks the specimen, both measured using a high precision 500N load cell and crosshead position sensor.

[0235] Dart Impact Dart Impact (DDI) was determined by ASTM D1709, Method "A", for films having the thicknesses indicated and produced as described in the Examples below.

[0236] f) Optical properties Gloss, clarity and haze as measures of the optical appearance of a film were determined according to ASTM D2457 (gloss) and ASTM D1003 (haze and clarity) for films having thicknesses as shown in the Examples below and produced as described.

[0237] The gloss of the outer and inner layers was determined at a 45° angle according to ASTM D2457. A BYK-Gardner Micro-TRI-Gloss Meter was used as the gloss measuring instrument, and the gloss values ​​were recorded and reported as Gloss Units (GU). The gloss was determined separately on both surfaces of the film.

[0238] g) Friction coefficient The coefficient of friction in dynamic and static conditions, both in / in and out / out, was determined according to ISO 8295.

[0239] h) Seal Initiation Temperature (SIT) In principle, a heat seal is formed by pressing two (polymeric) films together in intimate contact with each other while at least partially molten. This test method also covers the evaluation of the part after the heat sealing process. The force required to separate the specimens of the material containing the seal was measured using a UTM (also to identify the failure mode of the specimens). The specimens with the selected sealed surfaces and the films formed are prepared according to the ASTM F 2029;ASTM F 88 standards, as explained in the "Examples" below. A minimum of five specimens are used for each sealing temperature for the test. The term "seal initiation temperature" (SIT) is defined as "seal initiation temperature at 5N" and refers to the temperature at which a seal with a strength of 5N is formed after cooling. This is the temperature at which a heat seal is formed immediately after the sealing operation (seal time 1.0 sec, seal pressure 3 bar for films less than 65 microns thick, seal time 1.5 sec for films 65 microns thick or greater), and the strength of the heat seal is measured at predetermined time intervals (at least 24 hours after completion of the sealing cycle and after the seal has cooled to ambient temperature and reached maximum strength).

[0240] i) Hot tack temperature This test method is a procedure to determine the temperature required to reach a specified seal strength of a film sample under a specified seal time and pressure according to the ASTM F1921 standard. Thus, the hot tack test measures the heat seal strength of a film immediately after sealing, before cooling to room temperature conditions. The test requires a film specimen of at least 25 mm width and 250 mm length for each sealing temperature. The hot tack temperature (°C) at 1 N force was measured according to ASTM F1921 under the following conditions: sealing pressure 3 bar, dwell / seal time 1 second, cooling / delay time 100 ms (release), and test / peel speed 200 mm / s for films less than 65 microns. For thicknesses of 65 microns and above, similar test conditions with a dwell / seal time of 1.5 seconds were used.

[0241] j) Thickness Film thickness was determined according to ASTM D6988. EXAMPLES

[0242] Working Example A sealant (base) film with a three-layer structure was produced, consisting of a core layer, an inner layer and an outer layer. Example IE1 (BB5) represents a sealant film used in the laminate film of the present invention, while Examples CE1 (BB1), CE2 (BB2), CE3 (BB3) and CE4 (BB4) are comparative sealant films. Each sealant film has a thickness of 60 μm. The thickness of the core layer of each sealant film is 60% of the total thickness of each film, and the thickness of each outer layer (i.e., the inner layer and the outer layer) is 20% of the total thickness of each film.

[0243] The sealant films are non-oriented films (by definition). All film details are summarized below:

[0244] [Table 1]

[0245] The polymers used in the film preparation are shown below.

[0246] [Table 2]

[0247] The sealant film was laminated to a conventional PET substrate (12 μm) to form a PE sealant film-PET substrate laminate, and the laminate was named as follows: IE2: Laminate according to the invention comprising the sealant film IE1 (BB5) CE5: Comparative laminate containing sealant film CE1 (BB1) CE6: Comparative laminate containing sealant film CE2 (BB2) CE7: ​​Comparative laminate containing sealant film CE3 (BB3) CE8: Comparative laminate containing sealant film CE4 (BB4)

[0248] experiment Preparation of sealant films Blown films (60 μm) were produced on a Polyrema (Reifenhauser blown film line equipped with an internal bubble cooling system) with a production capacity of 150 kg / h and a cooling air temperature of 12-16° C. Details are as follows:

[0249] [Table 3]

[0250] Table 4 shows the temperature profile of the blown film line, i.e., the temperatures used for different layers of the blown film extruder at different locations in the blown film line.

[0251] [Table 4]

[0252] Lamination process The PET film was laminated with different sealant PE examples at Henkel Corporation using a 2:1 mixture of adhesive LA7732 and hardener LA6159. Lamination was performed using a solventless laminator at a running speed of 150 m / min at 2 g / m2. 2 The corona treatment intensity of the carrier web was 2.5 kW, and the secondary web was also 2.5 kW.

[0253] Film properties Sealant film (before lamination) Mechanical and other properties The sealant films were tested for several properties. The methods and results are shown below. As can be seen directly, the sealant film IE1 used in the laminate film of the present invention shows very good mechanical performance compared to the comparative films. The haze and friction coefficient are also improved over most of the comparative films.

[0254] [Table 5]

[0255] Sealing performance The sealing behavior of the base PE sealant films was determined by measuring the seal initiation temperature (SIT) at 5 N and hot tack temperature at 1 N on the inner (sealing) layer I of the inventive and comparative sealant films. In general, a lower heat seal initiation temperature and a lower hot tack temperature indicate better seal integrity performance, resulting in faster packaging speeds when the films are used in vFFS packaging applications.

[0256] Table 6 and Figures 2 and 3 show the results obtained, with the sealant film IE1 used in the laminate film of the present invention exhibiting the lowest seal initiation temperature at 5N and the lowest hot tack temperature at 1N.

[0257] Figure 1 shows the seal initiation temperature as a function of density for the LLDPE polymer used in the seal layer. As shown, in general, the seal initiation temperature decreases as the density of the polymer decreases. However, the IE1 film has a higher seal initiation temperature at the same density of 918 kg / m 3 The seal initiation temperature is 9°C to 10°C lower than that of the two comparative films CE1 and CE3.

[0258] [Table 6]

[0259] Laminate film (sealant film laminated to PET film) Mechanical and other properties Various properties of the laminate film were measured and the results are shown below.

[0260] [Table 7]

[0261] All laminate films show good stiffness (determined as tensile modulus), which is expected based on the PET substrate. The inventive film IE2 has the highest MD tensile modulus and also has good impact balance.

[0262] Also, the fracture resistance (energy to break) of the IE2 film is higher than that of films using LLDPE of similar density in the sealant layer. Surprisingly, however, the dart impact of all the laminate films was found to be in the range of 450-490g. This range is not significantly different from that obtained with the (base) sealant films. Only the CE2 and CE4 (base) sealant films have very high dart impact, but once these films were laminated to a PET film, they did not perform better than the other laminate films.

[0263] The optical properties of the IE2 film are comparable to those of the comparison film, making the laminate film sufficient for packaging applications, and the coefficient of friction is relatively low, making the IE2 film suitable for high-speed packaging operations on vFFS machines.

[0264] Sealing performance The sealing behavior of the laminated films was determined and is summarized below. [Table 8]

[0265] The seal initiation temperature of IE2 film is 95.1℃, and the same density is 918kg / m 3Lower seal initiation temperature (i.e., SIT is 100-102°C) than that of CE5 and CE7 films containing LLDPE. Much lower density (912 kg / m 3 Only the CE6 film containing 100% LLDPE showed a lower SIT temperature.

[0266] FIG. 4 depicts the seal initiation temperature of the laminate films as a function of the density of the LLDPE polymer used in the seal layer of each laminate film, illustrating the described correlation.

[0267] Similarly, the hot tack temperature of the IE2 film of the present invention is lower than that of the CE5 and CE7 films, at about 90° C. Among all the laminate films, only the CE8 film exhibits a lower hot tack temperature, and this film has a much lower density (914 kg / m) than the IE2 film. 3 ) LLDPE.

[0268] Figure 5 shows the hot tack temperature curves of the IE2, CE5 and CE7 laminate films. The IE2 film showed a broader hot tack strength curve than the comparative CE5 and CE7 films in the temperature range from 95°C to 130°C.

[0269] The improved sealing behavior of the IE2 films of the present invention results in better performance in faster packaging operations on vFFS equipment.

Claims

1. A laminate film, a) a polyethylene sealant film comprising at least an outer layer O, an inner layer I and a core layer C, the core layer C being between the outer layer O and the inner layer I; Here, the inner layer I has a strength of 915 to 925 kg / m ３ and a melt flow rate (MFR) of 0.5 to 3.0 g / 10 min as determined by ISO 1133 ２ an inner layer composition comprising 75 to 95 weight percent of component AI, which is a linear low density ethylene polymer having a molecular weight of 100 to 2000, weight percent being based on the total weight of the inner layer composition; and b) a substrate film laminated to the polyethylene sealant film; wherein the substrate film comprises a polyester polymer selected from the group consisting of polyethylene terephthalate, polybutylene terephthalate, and polytrimethylene terephthalate, and mixtures thereof; Including, Wherein, the seal initiation temperature SIT (5N) of the laminate film is less than 100°C, and is determined by ASTM F2029, ASTM F88 for the inner layer of the polyethylene sealant film; Laminating film.

2. The seal initiation temperature SIT (5N) of the laminate film is expressed by the following formula (I): SIT (°C) ≦ 1.6278 × density of component AI (kg / m ３ )-1395(I) The laminate film according to claim 1, wherein the seal initiation temperature is determined in the inner layer of the polyethylene sealant film according to ASTM F2029 and ASTM F88.

3. 3. A laminate film according to claim 1, wherein component AI is a multimodal linear low density ethylene polymer, preferably a multimodal terpolymer of ethylene with two comonomers selected from an α-olefin having 4 to 10 carbon atoms, preferably 1-butene and 1-hexene.

4. The component AI has a melt flow rate (MFR) of 1.0 to 2.0 g / 10 min as determined by ISO 1133. ２ 4. The laminate film of claim 1, having a molecular weight distribution (MWD) of 3.0 to 5.0 as determined by GPC conventional methods as defined herein.

5. The component AI is a bimodal terpolymer comprising an ethylene polymer component (A) and an ethylene polymer component (B), the ethylene polymer component (A) having a higher melt flow rate (MFR) as determined by ISO 1133 than the ethylene polymer component (B). ２ 5. The laminate film according to claim 1, wherein the ethylene polymer component (A) is a copolymer of ethylene and 1-butene and the ethylene polymer component (B) is a copolymer of ethylene and 1-hexene, preferably having a total comonomer content of 1 to 5 mol % in component AI.

6. The inner layer composition has a viscosity of 915 kg / m based on the total weight of the inner layer composition. ３ 6. The laminate film of claim 1, further comprising 5 to 25 weight percent of component BI, which is a low density ethylene polymer having a density greater than 0.

1.

7. Polyethylene sealant film: 915-925 kg / m ３ 70-95% by weight of an ethylene polymer having a density of 0.01 to 0.5% by weight of a low density ethylene polymer, both weight percentages being based on the total weight of the polyethylene sealant film.

8. At least one of the outer layer O and the core layer C comprises a composition comprising 50 to 90 weight % of a component AO or AC, said weight % being based on the total weight of the respective layer composition, which is a linear low density ethylene polymer, preferably a multimodal linear low density ethylene polymer, more preferably a bimodal linear low density ethylene copolymer of ethylene and a comonomer selected from α-olefins having 4 to 10 carbon atoms, said component AO or said AC having a viscosity of 915 to 925 kg / m ３ and a melt flow rate (MFR) of 0.2 to 2.0 g / 10 min as determined by ISO 1133 ２ The laminate film according to any one of claims 1 to 7, wherein

9. The laminate film according to any one of claims 1 to 8, wherein the polyethylene sealant film has a thickness of 40 to 100 μm and the base film has a thickness of 10 to 20 μm, the thickness being determined by ASTM D6988.

10. The laminate film according to any one of claims 1 to 9, wherein the substrate film is a monolayer film, preferably an oriented monolayer film, and / or the polyester polymer is polyethylene terephthalate.

11. The laminate film according to any one of claims 1 to 10, wherein the laminate film comprises the polyethylene sealant film, the base film, and optionally an adhesive layer between the polyethylene sealant film and the base film.

12. The following characteristics: a) a seal initiation temperature SIT(5N) of 90-99°C, determined on the inner layer of said polyethylene sealant film by ASTM F2029, ASTM F88; b) a hot tack temperature (1N) of 85-95°C, determined on the inner layer of the polyethylene sealant film by ASTM F1921; c) a machine direction (MD) tensile modulus (1% secant) of at least 1000 MPa, and / or a transverse direction (TD) tensile modulus (1% secant) of at least 900 MPa, as determined by ASTM D882; d) a haze value of less than 10% as determined by ASTM D1003, and / or a gloss value of at least 80 as determined by ASTM D2457 at 45° on the inner layer of the polyethylene sealant film; and / or e) Dart impact of at least 400 g as determined by ASTM D1709 "Method A" The laminate film according to any one of claims 1 to 11, having at least one of the following:

13. An article comprising the laminate film according to any one of claims 1 to 12.

14. 13. Use of the laminate film according to any one of claims 1 to 12 for packaging of articles.

15. 915 to 925 kg / m for improving the sealing performance of a base film comprising a polyester polymer selected from the group consisting of polyethylene terephthalate, polybutylene terephthalate, and polytrimethylene terephthalate, and mixtures thereof, when the polyethylene sealant film is laminated onto the base film. ３ and a melt flow rate (MFR) of 0.5 to 3.0 g / 10 min as determined by ISO 1133. ２ 2. Use of a polyethylene sealant film comprising an inner layer I made from an inner layer composition comprising 75 to 95 weight percent of component AI, which is a linear low density ethylene polymer having the formula:

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