Polyolefin composition with excellent balance of stiffness and toughness for films

Abstract

The present invention relates to a composition comprising a polyethylene-based material and a polypropylene-based material, a method of forming a film therefrom, and a film formed therefrom.

Description

Technical Field

[0001] The present invention relates to a composition comprising a polyethylene-based material and a polypropylene-based material, and a method of forming a film therefrom and a film formed therefrom. Background Art

[0002] In the production of polymer films, especially cast films, it is desirable to have a polymer with good processability to achieve commercial production volumes while maintaining sufficient toughness. In addition, the physical properties required for the final film product include stiffness, toughness and / or tear strength, etc.

[0003] Stiffness and toughness are key properties of polyethylene (PE) films. Examples of applications where stiffness and toughness of PE films are key properties include stand-up bags, sealed bags, heavy-duty bags, etc. Toughness can be characterized, for example, by dart impact resistance and needle puncture strength. Stiffness can be characterized, for example, by machine direction (MD) 1% secant modulus.

[0004] High-density polyethylene (HDPE) and polypropylene (PP) are two possible blending partners for polyethylene (PE) films to improve stiffness. However, the selection of PP as a blending partner is limited because PP and PE have different crystal phases and types, and there is little or no co-crystallization between PP and PE. Those skilled in the art generally believe that blending PP with PE can improve the stiffness of PE films, but will simultaneously reduce the toughness of PE films.

[0005] On the other hand, PP has many advantages over HDPE, such as lower density, higher stiffness, and higher heat resistance. If PP can be used in most PE formulations to improve the stiffness of the film while still maintaining toughness properties, it will show great value for industrial and food packaging thickness reduction of PP / PE film structures.

[0006]

[0006] Therefore, there is a need for improved polyolefin compositions having increased stiffness and having an excellent balance of stiffness and toughness, as well as methods of forming films from the polyolefin compositions and films formed from the polyolefin compositions.

[0007] Relevant publications include, for example, WO 2017 / 068106 and WO 2021 / 040760. Summary of the invention

[0008] The present invention provides a polyolefin composition using PP instead of HDPE, a method for forming a film from the polyolefin composition, and a film formed from the polyolefin composition, wherein the polyolefin composition using PP of the present invention unexpectedly achieves an excellent balance of stiffness and toughness compared to a polyolefin composition using HDPE.

[0009] According to one aspect of the present invention, there is provided a polyolefin composition comprising one or more broad orthogonal composition distribution (BOCD) polyethylenes and one or more polypropylenes.

[0010] According to embodiments of the present invention, the polyolefin composition comprises (or consists essentially of, or consists of) about 60 wt % to about 95 wt % BOCD polyethylene and about 5 wt % to about 40 wt % polypropylene, based on the weight of the polyolefin composition.

[0011] According to an embodiment of the present invention, the polyolefin composition comprises, for example, about 60wt%, about 65wt%, about 70wt%, about 75wt%, about 80wt%, about 85wt%, about 90wt%, about 95wt% of BOCD polyethylene based on the weight of the polyolefin composition. The content range of BOCD polyethylene includes a combination of any two of the above content values, such as about 60wt% to about 95wt%, about 60wt% to about 90wt%, etc. based on the weight of the polyolefin composition.

[0012] According to an embodiment of the present invention, based on the weight of the polyolefin composition, the polyolefin composition comprises, for example, about 5wt%, about 10wt%, about 15wt%, about 20wt%, about 25wt%, about 30wt%, about 35wt%, about 40wt% polypropylene. Based on the weight of the polyolefin composition, the content range of the polypropylene includes a combination of any two content values, for example, about 5wt% to about 40wt%, about 5wt% to about 35wt% etc.

[0013] According to an embodiment of the present invention, the BOCD polyethylene contains about 70 mol% to about 99 mol% of polymer units derived from ethylene, based on the total moles of polymer units of the BOCD polyethylene, and a density of about 0.91 g / cm 3 To about 0.925g / cm 3 , which is measured according to ASTM D-792 or ASTM D-1505, and a melt index (MI, or I 2.16 ), which is measured according to ASTM D-1238-E (190°C / 2.16kg).

[0014] According to embodiments of the present invention, the BOCD polyethylene is characterized as having a composition distribution breadth index (CDBI) of from about 25 wt % to about 55 wt %.

[0015] According to an embodiment of the present invention, the polypropylene is selected from the group consisting of homopolymers of polypropylene and impact copolymers of polypropylene and combinations thereof.

[0016] According to an embodiment of the present invention, the homopolymer of polypropylene has a melt index from about 1 g / 10 min to about 6 g / 10 min, as measured according to ASTM D1238-L (230° C. / 2.16 kg).

[0017] According to an embodiment of the present invention, the homopolymer of polypropylene has a molecular weight of from about 0.8 g / cm 3 To about 0.98g / cm 3 The density of the composite is determined according to ASTM D792-13.

[0018] According to an embodiment of the present invention, the homopolymer of polypropylene has a tensile strength at yield of from about 20 MPa to about 100 MPa, as measured according to ASTM D638.

[0019] According to an embodiment of the present invention, the impact copolymer of polypropylene has a melt index from about 1 g / 10 min to about 6 g / 10 min, as measured according to ASTM D1238-L (230° C. / 2.16 kg).

[0020] According to an embodiment of the present invention, the impact copolymer of polypropylene has a strength of from about 0.8 g / cm 3 To about 0.98g / cm 3 The density of the composite is determined according to ASTM D792-13.

[0021] According to an embodiment of the present invention, the impact copolymer of polypropylene has a tensile strength at yield of from about 10 MPa to about 100 MPa, as measured according to ASTM D638.

[0022] According to an embodiment of the present invention, the polyolefin composition of the present invention has a machine direction (MD) 1% secant modulus from greater than about 200 MPa, preferably greater than about 250 MPa, preferably greater than about 300 MPa, preferably greater than about 350 MPa, preferably greater than about 400 MPa, to less than about 410 MPa, or less than about 400 MPa, or less than about 350 MPa, or less than about 300 MPa, or less than about 250 MPa, when a film comprising (or consisting essentially of, or consisting of) the polyolefin composition of the present invention has a thickness of about 25 μm, measured, wherein the machine direction (MD) 1% secant modulus is measured according to ASTM D 882 method.

[0023] According to an embodiment of the present invention, the polyolefin composition comprising polypropylene (PP) of the present invention has substantially the same, preferably from greater than about 10%, or greater than about 20%, or greater than about 30%, or greater than about 40%, or greater than about 50%, or greater than about 60%, or greater than about 70%, or greater than about 80%, or greater than about 90%, or greater than about 100%, or greater than about 110%, or greater than about 120%, or greater than about 130%, or greater than about 140%, or greater than about 150%, or greater than about 160%, or greater than about 170%, or greater than about 180%, or greater than about 190%, or greater than about 200%, or greater than about 210%, or greater than about 220%, or greater than about 240%, or greater than about 250%, or greater than about 260%, or greater than about 270%, or greater than about 280%, or greater than about 290%, or greater than about 300%, or greater than about 310%, or greater than about 320%, or greater than about 330%, or greater than about 340%, or greater than about 350%, or greater than about 360%, or greater than about 370%, or greater than about 380%, or greater than about 390%, or greater than about 400%, or greater than about 410%, or greater than about 420%, or greater than about 430%, or greater than about 440%, or greater than about 450%, or greater than about 460%, or greater than about 470%, or greater than about 480%, or greater than about 490%, or greater than about 500%, or greater than about 510%, or greater than about 520%, or greater than about 530%, or greater than about 540%, or greater than about 550%, or greater than about about 220%, or greater than about 230%, or greater than about 240%, or greater than about 250%, to less than about 260%, or less than about 250%, or less than about 240%, or less than about 230%, or less than about 220%, or less than about 210%, or less than about 200%, or less than about 190%, or less than about 180%, or less than about 170%, or less than about 160%, or less than about 150%, or less than about 140%, or less than about 130%, or less than about 120%, or less than about 110%, or less than about 100%, or less than about 90%, or less than about 80%, or less than about 70%, or less than about 60%, or less than about 50% of the dart drop impact strength / thickness value (g / μm), wherein the dart drop impact strength is measured according to ASTM D 1709 method, wherein the high density polyethylene (HDPE) has a dart drop impact strength / thickness value (g / μm) greater than 0.940 g / cm 3 and a melt index of about 0.5 g / 10 min to about 10 g / 10 min, wherein the density is measured according to ASTM D-1505 and the melt index is measured according to ASTM D1238-E (190° C. / 2.16 kg).

[0024] According to an embodiment of the present invention, the expression "substantially the same dart impact strength / thickness value (g / μm)" with respect to the polyolefin composition means that the dart impact strength / thickness values ​​differ by about ±1%, or by about ±2%, or by about ±3%, or by about ±4%.

[0025] According to an embodiment of the present invention, the polyolefin composition comprising polypropylene (PP) of the present invention has a needle punch strength value (mN / μm) that is substantially the same, preferably from greater than about 4%, or greater than about 5%, or greater than about 6%, or greater than about 7%, or greater than about 8%, or greater than about 9%, or greater than about 10%, or greater than about 15%, or greater than about 20%, or greater than about 25%, or greater than about 26%, or greater than about 27%, or greater than about 28%, or greater than about 29%, to less than about 30%, or less than about 29%, or less than about 28%, or less than about 27%, or less than about 26%, or less than about 25%, or less than about 20%, or less than about 15%, or less than about 10%, or less than about 9%, or less than about 8%, or less than about 7%, compared to a polyolefin composition with high density polyethylene replacing the polypropylene and being the same in other aspects, wherein the needle punch strength is measured according to CEN 14477 method, wherein the high density polyethylene (HDPE) has a value of greater than 0.940 g / cm 3 and a melt index of about 0.5 g / 10 min to about 10 g / 10 min, wherein the density is measured according to ASTM D-1505 and the melt index is measured according to ASTM D1238-E (190° C. / 2.16 kg).

[0026] According to an embodiment of the present invention, the expression "substantially the same needle punch strength value (mN / μm)" regarding the polyolefin composition means that the needle punch strength values ​​differ by about ±1%, or by about ±2%, or by about ±3%.

[0027] According to an embodiment of the present invention, the present invention provides a polyolefin composition comprising about 60 wt % to about 95 wt % of BOCD polyethylene and about 5 wt % to about 40 wt % of polypropylene, based on the weight of the polyolefin composition,

[0028] wherein the BOCD polyethylene contains from about 70 mol % to about 99 mol % of polymer units derived from ethylene, based on the total moles of polymer units of the BOCD polyethylene, and has a density of about 0.918 g / cm 3 , which is measured according to ASTM D-792, and a melt index (MI, or I 2.16 ), which is measured according to ASTM D-1238-E (190°C / 2.16 kg), and the BOCD polyethylene has a composition distribution breadth index (CDBI) of about 38.6 wt%, or

[0029] wherein the BOCD polyethylene contains from about 70 mol % to about 99 mol % of polymer units derived from ethylene, based on the total moles of polymer units of the BOCD polyethylene, and has a density of about 0.915 g / cm3 , which is measured according to ASTM D1505, and a melt index (MI, or I 2.16 ), which is measured according to ASTM D-1238-E (190°C / 2.16kg), and the BOCD polyethylene has a composition distribution breadth index (CDBI) of about 43 wt%,

[0030] The polypropylene is selected from the group consisting of a homopolymer of polypropylene, an impact copolymer of polypropylene, and a combination thereof,

[0031] wherein the homopolymer of polypropylene has a melt index of about 3.2 g / 10 min as measured according to ASTM D1238-L (230° C. / 2.16 kg), and

[0032] wherein the impact copolymer of polypropylene has a melt index of about 4.0 g / 10 min as measured according to ASTM D1238-L (230° C. / 2.16 kg); or

[0033] Preferably, the homopolymer of polypropylene has a tensile strength at yield of about 31.5 MPa, as measured according to ASTM D638; or

[0034] Preferably, the impact copolymer of polypropylene has a strength of 0.900 g / cm 3 Preferably, the impact copolymer of polypropylene has a yield tensile strength of 23.7MPa, as determined in accordance with ASTM D638; or

[0035] Preferably, the polyolefin composition has a machine direction (MD) 1% secant modulus from greater than about 200 MPa to less than about 410 MPa, measured when a film comprising the polyolefin composition has a thickness of about 25 μm, wherein the machine direction (MD) 1% secant modulus is measured according to ASTM D 882 method; or

[0036] Preferably, the polyolefin composition comprising the polypropylene has a dart drop impact strength / thickness value (g / μm) that is substantially the same, or from greater than about 10% to less than about 260%, as compared to an otherwise identical polyolefin composition in which the polypropylene is replaced with a high density polyethylene, wherein the dart drop impact strength is measured according to the ASTM D 1709 method, wherein the high density polyethylene (HDPE) has a value of about 0.961 g / cm 3 A density of about 0.70 g / 10 min and a melt index of about 0.70 g / 10 min, wherein the density is measured according to ASTM D-1505 and the melt index is measured according to ASTM D1238-E (190° C. / 2.16 kg); or

[0037] Preferably, the polyolefin composition comprising the polypropylene has a needle punch strength value (mN / μm) that is substantially the same, or from greater than about 4% to less than about 30%, compared to an otherwise identical polyolefin composition in which the polypropylene is replaced with a high density polyethylene, wherein the needle punch strength is measured according to the CEN 14477 method, wherein the high density polyethylene (HDPE) has a value of about 0.961 g / cm 3 and a melt index of about 0.70 g / 10 min, wherein the density is measured according to ASTM D-1505 and the melt index is measured according to ASTM D1238-E (190° C. / 2.16 kg).

[0038] According to one aspect of the present invention, there is provided a film comprising (or consisting essentially of, or consisting of) the polyolefin composition of the present invention.

[0039] The film of the present invention may be a monolayer film, or a multilayer film, wherein any layer of the multilayer film may comprise (or consist essentially of, or consist of) the polyolefin composition of the present invention.

[0040] The thickness of the film of the present invention can be selected and determined according to actual needs.

[0041] The film of the present invention can be produced using a casting method known in the art for producing polyethylene (PE) films.

[0042] According to an embodiment of the present invention, the film comprising (or consisting essentially of, or consisting of) the polyolefin composition of the present invention has a machine direction (MD) 1% secant modulus from greater than about 200 MPa, preferably greater than about 250 MPa, preferably greater than about 300 MPa, preferably greater than about 350 MPa, preferably greater than about 400 MPa, to less than about 410 MPa, or less than about 400 MPa, or less than about 350 MPa, or less than about 300 MPa, or less than about 250 MPa, measured when the film comprising the polyolefin composition of the present invention has a thickness of about 25 μm, wherein the machine direction (MD) 1% secant modulus is measured according to ASTM D 882 method.

[0043] According to an embodiment of the present invention, the film of the present invention comprising (or consisting essentially of, or consisting of) the polyolefin composition has substantially the same, preferably from greater than about 10%, or greater than about 20%, or greater than about 30%, or greater than about 40%, or greater than about 50%, or greater than about 60%, or greater than about 70%, or greater than about 80%, or greater than about 90%, or greater than about 100%, or greater than about 110%, or greater than about 120%, or greater than about 130%, or greater than about 140%, or greater than about 150%, or greater than about 160%, or greater than about 170%, or greater than about 180%, or greater than about 190%, or greater than about 200%, or greater than about 210%, compared to a film in which high density polyethylene (HDPE) is substituted for polypropylene and which is otherwise the same. or greater than about 220%, or greater than about 230%, or greater than about 240%, or greater than about 250%, to less than about 260%, or less than about 250%, or less than about 240%, or less than about 230%, or less than about 220%, or less than about 210%, or less than about 200%, or less than about 190%, or less than about 180%, or less than about 170%, or less than about 160%, or less than about 150%, or less than about 140%, or less than about 130%, or less than about 120%, or less than about 110%, or less than about 100%, or less than about 90%, or less than about 80%, or less than about 70%, or less than about 60%, or less than about 50% of the dart drop impact strength / thickness value (g / μm), wherein the dart drop impact strength is measured according to ASTM D 1709 method, wherein the high density polyethylene (HDPE) has a dart drop impact strength / thickness value (g / μm) greater than 0.940 g / cm 3 and a melt index of about 0.5 g / 10 min to about 10 g / 10 min, wherein the density is measured according to ASTM D-1505 and the melt index is measured according to ASTM D1238-E (190° C. / 2.16 kg).

[0044] According to an embodiment of the present invention, the expression "substantially the same dart impact strength / thickness values ​​(g / μm)" with respect to the film of the present invention comprising (or essentially consisting of, or consisting of) the polyolefin composition means that the dart impact strength / thickness values ​​differ by about ±1%, or by about ±2%, or by about ±3%, or by about ±4%.

[0045] According to an embodiment of the present invention, the film of the present invention comprising (or consisting essentially of, or consisting of) the polyolefin composition has a needle punch strength value (mN / μm) substantially the same, preferably from greater than about 4%, or greater than about 5%, or greater than about 6%, or greater than about 7%, or greater than about 8%, or greater than about 9%, or greater than about 10%, or greater than about 15%, or greater than about 20%, or greater than about 25%, or greater than about 26%, or greater than about 27%, or greater than about 28%, or greater than about 29%, to less than about 30%, or less than about 29%, or less than about 28%, or less than about 27%, or less than about 26%, or less than about 25%, or less than about 20%, or less than about 15%, or less than about 10%, or less than about 9%, or less than about 8%, or less than about 7%, compared to a film in which the polypropylene is replaced with a high density polyethylene (HDPE) and is the same in other aspects, wherein the needle punch strength is measured according to the CEN 14477 method, wherein the high density polyethylene (HDPE) has a needle punch strength value (mN / μm) of greater than 0.940 g / cm 3 and a melt index of about 0.5 g / 10 min to about 10 g / 10 min, wherein the density is measured according to ASTM D-1505 and the melt index is measured according to ASTM D1238-E (190° C. / 2.16 kg).

[0046] According to an embodiment of the present invention, the expression "substantially the same needle puncture strength value (mN / μm)" with respect to the film of the present invention comprising (or essentially consisting of, or consisting of) the polyolefin composition means that the needle puncture strength values ​​differ by about ±1%, or by about ±2%, or by about ±3%.

[0047] According to an embodiment of the present invention, the present invention provides a film comprising a polyolefin composition, wherein the polyolefin composition comprises from about 60 wt % to about 95 wt % of BOCD polyethylene and from about 5 wt % to about 40 wt % of polypropylene, based on the weight of the polyolefin composition,

[0048] wherein the BOCD polyethylene contains from about 70 mol % to about 99 mol % of polymer units derived from ethylene, based on the total moles of polymer units of the BOCD polyethylene, and has a density of about 0.918 g / cm 3 , which is measured according to ASTM D-792, and a melt index (MI, or I 2.16 ), which is measured according to ASTM D-1238-E (190°C / 2.16 kg), and the BOCD polyethylene has a composition distribution breadth index (CDBI) of about 38.6 wt%, or

[0049] wherein the BOCD polyethylene contains from about 70 mol % to about 99 mol % of polymer units derived from ethylene, based on the total moles of polymer units of the BOCD polyethylene, and has a density of about 0.915 g / cm 3 , which is measured according to ASTM D1505, and a melt index (MI, or I 2.16 ), which is measured according to ASTM D-1238-E (190°C / 2.16kg), and the BOCD polyethylene has a composition distribution breadth index (CDBI) of about 43 wt%,

[0050] The polypropylene is selected from the group consisting of a homopolymer of polypropylene, an impact copolymer of polypropylene, and a combination thereof,

[0051] wherein the homopolymer of polypropylene has a melt index of about 3.2 g / 10 min as measured according to ASTM D1238-L (230° C. / 2.16 kg), and

[0052] wherein the impact copolymer of polypropylene has a melt index of about 4.0 g / 10 min as measured according to ASTM D1238-L (230° C. / 2.16 kg); and

[0053] wherein the film has a machine direction (MD) 1% secant modulus from greater than about 200 MPa to less than about 410 MPa, measured when the film comprising the polyolefin composition has a thickness of about 25 μm, wherein the machine direction (MD) 1% secant modulus is measured according to ASTM D 882 method; or

[0054] Preferably, the homopolymer of polypropylene has a density of about 0.900 g / cm 3 A density of about 31.5 MPa as measured in accordance with ASTM D792-13; preferably, the homopolymer of polypropylene has a yield tensile strength of about 31.5 MPa as measured in accordance with ASTM D638; or

[0055] Preferably, the impact copolymer of polypropylene has a strength of 0.900 g / cm 3 Preferably, the impact copolymer of polypropylene has a yield tensile strength of 23.7 MPa, as measured in accordance with ASTM D638; or

[0056] Preferably, the film comprising polypropylene has a dart drop impact strength / thickness value (g / μm) that is substantially the same, or from greater than about 10% to less than about 260%, as compared to an otherwise identical film in which the polypropylene is replaced with a high density polyethylene, wherein the dart drop impact strength is measured according to the ASTM D 1709 method, wherein the high density polyethylene (HDPE) has a thickness of about 0.961 g / cm 3A density of about 0.70 g / 10 min and a melt index of about 0.70 g / 10 min, wherein the density is measured according to ASTM D-1505 and the melt index is measured according to ASTM D1238-E (190° C. / 2.16 kg); or

[0057] Preferably, the film comprising polypropylene has a needle punch strength value (mN / μm) that is substantially the same, or from greater than about 4% to less than about 30%, compared to an otherwise identical film in which the polypropylene is replaced with a high density polyethylene, wherein the needle punch strength is measured according to the CEN 14477 method, wherein the high density polyethylene (HDPE) has a value of about 0.961 g / cm 3 and a melt index of about 0.70 g / 10 min, wherein the density is measured according to ASTM D-1505 and the melt index is measured according to ASTM D1238-E (190° C. / 2.16 kg).

[0058] According to one aspect of the present invention, the present invention provides packaging, such as industrial packaging and food packaging, comprising the film of the present invention, wherein the film of the present invention comprises the polyolefin composition of the present invention.

[0059] According to an embodiment of the present invention, the films made by the present invention are suitable for use in upright, flexible packages or pouches. Such a package will be stiff enough to be formed into a shape that allows it to stand upright, for example, with a label on the front thereof, but soft enough to allow the user to bend and / or squeeze the package to force and / or pour out the liquid.

[0060] Broad Orthogonal Composition Distribution (BOCD) Polyethylene

[0061] The polyolefin compositions of the present invention include one or more broad orthogonal composition distributions (BOCD) polyethylenes. Broad orthogonal composition distributions (BOCD) polyethylenes are polyethylene homopolymers or polyethylene copolymers, in most cases polyethylene copolymers. It is desirable that polyethylene has a broad orthogonal composition distribution, which provides enhanced stiffness, toughness and processability (S / T / P) balance for polyethylene and compositions comprising these polymers. Considering that polymers are blends of molecules with different chain length distributions, polymers with BOCD are branched polymers, which have any branching that occurs on the high molecular weight molecules of the polymer, if not all, which makes them less crystalline. This microstructure has a trend of improving certain properties of products made from the BOCD type polymers (including polyolefin compositions as described herein).

[0062] Ziegler-Natta ("ZN") produced polyethylenes tend not to have a BOCD type structure, with most of the short chain branching occurring on the low molecular weight portion of the molecules so produced. On the other hand, some metallocene polyethylenes can often have a BOCD type structure. The value of BOCD polymers relative to conventional polymers is significant.

[0063] In embodiments of the present invention, the BOCD polyethylene may have a "broad orthogonal composition distribution" ("BOCD"). The broad orthogonal composition distribution may be determined using a fractionation technique, such as gel permeation chromatography-differential viscometer (GPC-DV), temperature rising elution fractionation-differential viscometer (TREF-DV), or a cross-fractionation technique. For example, WO 2015 / 123164A1 (which is incorporated herein by reference) discusses the TREF technique, providing a measurement of the bivariate mass distribution of the crystalline portion of a BOCD polyethylene.

[0064] The BOCD polyethylene of the present invention comprises about 70 mol% to about 99 mol% of units derived from ethylene, based on the total moles of polymer units of the BOCD polyethylene. Based on the total moles of polymer units of the BOCD polyethylene, the lower limit of the content range of units derived from ethylene can be 70 mol%, 75 mol%, 80 mol%, 85 mol%, 90 mol%, 92 mol%, 94 mol%, 95 mol%, 96 mol%, 97 mol%, 98 mol% or 99 mol%. Based on the total moles of polymer units of the BOCD polyethylene, the upper limit of the content range of units derived from ethylene can be 80 mol%, 85 mol%, 90 mol%, 92 mol%, 94 mol%, 95 mol%, 96 mol%, 97 mol%, 98 mol%, 99 mol%, 99.5 mol% or 100 mol%. Any of the above upper limit contents can be combined with any of the above upper limit contents; any of the above upper limit contents can be combined with any of the above lower limit contents; and any of the above upper limit contents can be combined with any of the above lower limit contents.

[0065] The BOCD polyethylene of the present invention may have equal to or less than 30 mol% of polymer units derived from C3-C20 olefins, such as C3-C20 α-olefins, such as hexene or octene. Based on the total moles of polymer units of the BOCD polyethylene, the upper limit of the content range of polymer units derived from C3-C20 olefins may be 30 mol%, 25 mol%, 20 mol%, 15 mol%, 10 mol%, 8 mol%, 6 mol%, 5 mol%, 4 mol%, 3 mol%, 2 mol%, 1 mol% or 0.5 mol%. Based on the total moles of polymer units of the BOCD polyethylene, the lower limit of the content range of polymer units derived from C3-C20 olefins may be 0 mol%, 1 mol%, 2 mol%, 3 mol%, 4 mol%, 5 mol%, 6 mol%, 8 mol%, 10 mol%, 15 mol%, 20 mol% or 25 mol%. Any of the above upper limits may be combined with any of the above upper limits; any of the above upper limits may be combined with any of the above lower limits; and any of the above upper limits may be combined with any of the above lower limits.

[0066] According to an embodiment of the present invention, the density of BOCD polyethylene measured according to ASTM D-792 or ASTM D-1505 may be 0.910 g / cm 3 Up to 0.925g / cm 3 , or 0.910g / cm 3 Up to 0.923g / cm 3 , 0.910g / cm 3 Up to 0.920g / cm 3 , 0.915g / cm 3 To 0.921g / cm 3 , 0.910g / cm 3 Up to 0.918g / cm 3 , 0.912g / cm 3 Up to 0.918g / cm 3 or 0.912 g / cm 3 Up to 0.917g / cm 3 .

[0067] According to an embodiment of the present invention, the BOCD polyethylene has a melt index (MI, or I) of about 0.5 g / 10 min to about 3.0 g / 10 min, preferably about 1.0 g / 10 min to about 2.0 g / 10 min. 2.16 ), which is measured according to ASTM D-1238-E (190°C / 2.16kg).

[0068] The term "Composition Distribution Breadth Index (CDBI)" represents the weight percent of copolymer molecules having a comonomer content within 50% of the median molar content of all comonomers. The BOCD polyethylenes of the present invention typically have a broad composition distribution as measured by the Composition Distribution Breadth Index (CDBI).

[0069] The CDBI of a copolymer can be measured using techniques known in the art. The CDBI of a copolymer is easily determined using well-known techniques for isolating individual fractions of a copolymer sample. One such technique is temperature rising elution fractionation (TREF), as described in Wild et al., J. Poly. Sci., Poly. Phys. Ed., Vol. 20, pp. 441-455 (1982), which is incorporated herein by reference. Generally, a high CDBI indicates that most components are washed out in a shorter period of time (smaller temperature range) and the comonomer distribution is narrow; a low CDBI indicates that most components are washed out in a longer period of time (larger temperature range), indicating that the comonomer distribution is wide.

[0070] Details on determining the CDBI of a copolymer are known to those skilled in the art, for example, see PCT patent application WO 1993 / 003093 published on February 18, 1993 (which is incorporated herein by reference), the content regarding CDBI in the specification, such as the fourth paragraph on page 13 of the specification, the transition paragraph on pages 14-15, the transition paragraph on pages 18-19, etc.

[0071] According to embodiments of the present invention, the BOCD polyethylene is characterized as having a composition distribution breadth index (CDBI) of from about 25 wt % to about 55 wt %.

[0072] Materials and methods for making BOCD polyethylene have been described in, for example, U.S. Patent No. 6,956,088, particularly Example 1; U.S. Patent Application Publication No. 2009 / 0297810, particularly Example 1; U.S. Patent Application Publication No. 2015 / 0291748, particularly PE1-PE5 in the examples; and WO 2014 / 099356, particularly PE3 mentioned on page 12 and in the examples, including the use of a silica-supported hafnium transition metallocene / methylaluminoxane catalyst system as described, for example, in U.S. Patent Nos. 6,242,545 and 6,248,845 (particularly Example 1).

[0073] Many BOCD polyethylenes are commercially available. One or more BOCD polyethylenes are commercially available from ExxonMobil Chemical Company, Houston, TX, and as Exceed TMXP metallocene polyethylene (mPE) sales. Exceed TM XPmPE offers advantageous properties such as dart impact strength, flex crack resistance and machine direction (MD) tear, as well as maintaining stiffness at lower density. TM XP mPE also offers a good balance of melt strength, toughness, stiffness and sealing capabilities, which makes this class of polymers well suited for example in blown film / sheet applications.

[0074] Other BOCD polyethylenes commercially available from ExxonMobil Chemical Company, Houston, TX include EXT515 and the like.

[0075] The following BOCD polyethylene was used in the examples of this application:

[0076] Exceed TM XP 8318 is a polyethylene available from ExxonMobil Chemical Company, Houston, TX, which is a copolymer of ethylene and 1-hexene with a molecular weight of 0.918 g / cm2 as measured according to ASTM D792. 3 A density of 1.0 g / 10 min and a melt index of 1.0 g / 10 min measured according to ASTM D1238-E (190° C. / 2.16 kg), and a composition distribution breadth index (CDBI) of about 38.6 wt %;

[0077] EXT515 is a polyethylene available from ExxonMobil Chemical Company, Houston, TX, which is a copolymer of ethylene and 1-hexene with a molecular weight of 0.915 g / cm2 as measured according to ASTM D1505. 3 and a melt index of 1.4 g / 10 min measured according to ASTM D1238-E (190° C. / 2.16 kg), and a composition distribution breadth index (CDBI) of about 43 wt %.

[0078] Polypropylene

[0079] According to the present invention, the polypropylene is selected from homopolypropylene and impact polypropylene.

[0080] The polyolefin composition of the present invention comprises one or more polypropylenes. The polypropylene may be a propylene homopolymer or a propylene copolymer.

[0081] "Polypropylene" is a polymer comprising at least 50 mol%, e.g., at least 60 mol%, at least 70 mol%, at least 80 mol%, at least 90 mol%, or even 100 mol%, of polymer units derived from propylene, based on the total moles of polymer units of polypropylene.

[0082] The polypropylene may have a polymer unit derived from ethylene and / or one or more C4-C20 olefins, such as C4-C20 alpha-olefins, such as hexene or octene, equal to or less than 50 mol%, based on the total moles of the polymer units of the polypropylene. The upper limit of the content range of the polymer unit derived from C4-C20 olefins based on the total moles of the polymer units of the polypropylene may be 50 mol%, 45 mol%, 40 mol%, 35 mol%, 30 mol%, 25 mol%, 20 mol%, 15 mol%, 10 mol%, 8 mol%, 6 mol%, 5 mol%, 4 mol%, 3 mol%, 2 mol%, 1 mol% or 0.5 mol%. The lower limit of the content range of the polymer unit derived from C4-C20 olefins based on the total moles of the polymer units of the polypropylene may be 0 mol%, 0.5 mol%, 2 mol%, 3 mol%, 4 mol%, 5 mol%, 6 mol%, 8 mol%, 10 mol%, 15 mol%, 20 mol%, 25 mol%, 30 mol%, 35 mol%, 40 mol% or 45 mol%. Any of the above upper limits may be combined with any of the above upper limits; any of the above upper limits may be combined with any of the above lower limits; and any of the above upper limits may be combined with any of the above lower limits.

[0083] According to an embodiment of the present invention, the polypropylene may be or include one or more homopolymers (hPP) of PP, or one or more impact copolymers (ICP) of PP, or any combination thereof.

[0084] Homopolymer of polypropylene (hPP)

[0085] In an embodiment of the present invention, the polypropylene may be or include one or more homopolymers of polypropylene (hPP).

[0086] According to an embodiment of the present invention, the homopolymer of polypropylene (hPP) can have a melt index of from about 1 g / 10min, about 1.2 g / 10min, about 1.4 g / 10min, about 1.6 g / 10min or about 1.8 g / 10min to about 2 g / 10min, about 2.2 g / 10min, about 2.5 g / 10min, about 2.8 g / 10min, about 3 g / 10min, about 3.5 g / 10min, about 4 g / 10min, about 4.5 g / 10min, about 5 g / 10min, about 5.5 g / 10min or about 6 g / 10min, which is measured according to ASTM D1238-L (230°C / 2.16 kg). The combination of any of the above upper limits and any of the lower limits is also within the scope of the present invention.

[0087] According to an embodiment of the present invention, the homopolymer of polypropylene (hPP) may have a molecular weight from about 0.8 g / cm 3 , about 0.82g / cm 3 , about 0.84g / cm 3 , about 0.85g / cm 3 , about 0.86g / cm 3 or about 0.88g / cm 3 To about 0.9g / cm 3 , about 0.92g / cm 3 , about 0.95g / cm 3 or about 0.98g / cm 3 The density of the present invention is determined according to ASTM D792-13. The combination of any upper limit and any lower limit mentioned above is also within the scope of the present invention.

[0088] According to an embodiment of the present invention, the homopolymer of polypropylene (hPP) can have a yield tensile strength of from about 20 MPa, about 25 MPa, about 30 MPa, or about 35 MPa to about 40 MPa, about 45 MPa, about 50 MPa, about 60 MPa, about 80 MPa or about 100 MPa, as measured according to ASTM D638. The combination of any upper limit and any lower limit mentioned above is also within the scope of the present invention.

[0089] In the examples of the present invention, T30S from Maoming Petrochemical, ie, "PP PPH-T03 (T30S) Sinopec / Wire Drawing Grade" is used as the polypropylene homopolymer (hPP).

[0090] The polypropylene homopolymer of "PP PPH-T03 (T30S) Sinopec / Drawing Grade" has the following performance parameters:

[0091] Melt index: 3.2 g / 10 min, measured at 230 ° C and 2.16 kg;

[0092] Isotactic index: 97.2%;

[0093] Ash content: 0.02%;

[0094] Tensile break nominal strain: 498%;

[0095] Yield tensile strength: 31.5MPa;

[0096] Density: 0.900g / cm 3 , which is measured according to ASTM D792-13.

[0097] Impact Copolymer of Polypropylene (ICP)

[0098] In an embodiment of the present invention, the polypropylene may be or include one or more impact copolymers (ICP) of polypropylene.

[0099] According to an embodiment of the present invention, the impact copolymer of polypropylene (ICP) can have a melt index of from about 1 g / 10min, about 2 g / 10min, about 2.2 g / 10min, about 2.5 g / 10min, about 2.8 g / 10min, about 3 g / 10min, about 3.2 g / 10min, about 3.5 g / 10min to about 3.8 g / 10min, about 4 g / 10min, about 4.5 g / 10min, about 5 g / 10min, about 5.5 g / 10min or about 6 g / 10min, which is measured according to ASTM D1238-L (230°C / 2.16 kg). The combination of any of the above upper limits and any of the lower limits is also within the scope of the present invention.

[0100] According to an embodiment of the present invention, the impact copolymer of polypropylene (ICP) may have a molecular weight from about 0.8 g / cm 3 , about 0.82g / cm 3 , about 0.84g / cm 3 , about 0.85g / cm 3 , about 0.86g / cm 3 or about 0.88g / cm 3 To about 0.9g / cm 3 , about 0.92g / cm 3 , about 0.95g / cm 3 or about 0.98g / cm 3 The density of the present invention is determined according to ASTM D792-13. The combination of any upper limit and any lower limit mentioned above is also within the scope of the present invention.

[0101] According to an embodiment of the present invention, the impact copolymer of polypropylene (ICP) can have a yield tensile strength of from about 10MPa, about 15MPa, about 18MPa, about 20MPa, about 25MPa, about 30MPa, or about 35MPa to about 40MPa, about 45MPa, about 50MPa, about 60MPa, about 80MPa or about 100MPa, as measured according to ASTM D638. The combination of any of the above upper limits and any of the lower limits is also within the scope of the present invention.

[0102] In the embodiments of the present invention, ExxonMobil TM PP7032E3 was used as the impact copolymer of polypropylene (ICP), which was purchased from ExxonMobil Chemical Company, Houston, TX.

[0103] ExxonMobil TM PP7032E3 has the following performance parameters:

[0104] Melt index: 4.0 g / 10 min, measured according to ASTM D1238-L (230°C / 2.16 kg);

[0105] Density: 0.900g / cm 3 , which is determined according to ASTM D792-13;

[0106] Tensile strength at yield: 23.7 MPa, measured according to ASTM D638.

[0107] High Density Polyethylene

[0108] The high density polyethylene (HDPE) according to the present invention has a thickness greater than 0.940 g / cm 3 and a melt index of about 0.5 g / 10 min to about 10 g / 10 min, wherein the density is measured according to ASTM D-1505 and the melt index is measured according to ASTM D1238-E (190° C. / 2.16 kg).

[0109] In the embodiments of the present invention, ExxonMobil TM HDPE HTA 108 was used as high density polyethylene, which was purchased from ExxonMobil Chemical Company, Houston, TX.

[0110] ExxonMobil TM HDPE HTA 108 has the following performance parameters:

[0111] Density: 0.961g / cm 3 , measured according to ASTM D-1505;

[0112] Melt index: 0.70 g / 10 min, which is measured according to ASTM D-1238-E (190° C. / 2.16 kg).

[0113] additive

[0114] According to embodiments of the present invention, other additives may also be present in the polyolefin compositions and films of the present invention.

[0115] These additives may include antioxidants (e.g., hindered phenols and phosphites), stabilizers such as lactones and vitamin E, nucleating agents (α-nucleating agents and β-nucleating agents), clarifying agents, colorants (dyes or pigments), fillers (silicon dioxide or talc), UV stabilizers, mold release agents, slip agents, tackifiers, antistatic agents, acid scavengers (e.g., calcium stearate), antiblocking agents, antiblooming agents, polymer processing aid masterbatch (PPA MB) additives / agents, hydrocarbon resins such as Oppera TM Resin or a combination thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0116] Figure 1 is a bar graph showing the MD elongation at break (%) of the following formulations: pure Exceed XP 8318ML; 90wt% Exceed XP 8318ML+10wt% T30S; 80wt% Exceed XP 8318ML+20wt% T30S; 80wt% Exceed XP 8318ML+20wt% ICP7032; and 80wt% Exceed XP 8318ML+20wt% HTA108, based on the weight of the monolayer film; and

[0117] Pure EXT 515; 80 wt% EXT 515 + 20 wt% T30S; 80 wt% EXT 515 + 20 wt% ICP7032; and 80 wt% EXT 515 + 20 wt% HTA 108, based on the weight of the monolayer film. ICP7032 is an ExxonMobil TM PP7032E3.

[0118] Figure 2 is a bar graph showing the MD 1% secant modulus (MPa) of the following formulations: pure Exceed XP 8318ML; 90wt% Exceed XP 8318ML+10wt% T30S; 80wt% Exceed XP 8318ML+20wt% T30S; 80wt% Exceed XP 8318ML+20wt% ICP7032; and 80wt% Exceed XP 8318ML+20wt% HTA 108, based on the weight of the monolayer film; and

[0119] Pure EXT 515; 80 wt% EXT 515 + 20 wt% T30S; 80 wt% EXT 515 + 20 wt% ICP7032; and 80 wt% EXT 515 + 20 wt% HTA 108, based on the weight of the monolayer film. ICP7032 is an ExxonMobil TM PP7032E3.

[0120] Figure 3 The following is a bar graph showing the dart impact strength / thickness (g / μm) for the following formulations:

[0121] Pure Exceed XP 8318ML; 90wt% Exceed XP 8318ML+10wt% T30S; 80wt% Exceed XP 8318ML+20wt% T30S; 80wt% Exceed XP 8318ML+20wt% ICP7032; and 80wt% Exceed XP 8318ML+20wt% HTA 108, based on the weight of the monolayer film; and

[0122] Pure EXT 515; 80 wt% EXT 515 + 20 wt% T30S; 80 wt% EXT 515 + 20 wt% ICP7032; and 80 wt% EXT 515 + 20 wt% HTA 108, based on the weight of the monolayer film. ICP7032 is an ExxonMobil TM PP7032E3.

[0123] Figure 4 A bar graph showing the needle puncture strength (mN / μm) of the following formulations: pure Exceed XP 8318ML; 90wt% Exceed XP 8318ML+10wt% T30S; 80wt% Exceed XP 8318ML+20wt% T30S; 80wt% Exceed XP 8318ML+20wt% ICP7032; and 80wt% Exceed XP 8318ML+20wt% HTA108, based on the weight of the monolayer film; and

[0124] Pure EXT 515; 80 wt% EXT 515 + 20 wt% T30S; 80 wt% EXT 515 + 20 wt% ICP7032; and 80 wt% EXT 515 + 20 wt% HTA 108, based on the weight of the monolayer film. ICP7032 is an ExxonMobil TM PP7032E3. DETAILED DESCRIPTION

[0125] In order to better understand the technical solution of the present invention, the applicant provides the following examples for illustration. The examples are only for the purpose of illustration and do not limit the scope of protection of the present invention.

[0126] Measurement method

[0127] The present invention uses the following measurement method.

[0128]

[0129] Example

[0130] Examples 1-2 are both single-layer films, and the thickness of the films is 25 μm. Examples 1-2 are both manufactured under the same casting process conditions.

[0131] Casting process: The screw temperature of extruders ABCDE is set at about 265℃, the distributor temperature is set at about 265℃, and the die head temperature is set at about 265℃. The sampling line speed is about 200m / min.

[0132] Example 1

[0133] Table 1 compares the various properties of the following monolayer films with different compositions: pure Exceed XP 8318ML; 80 wt% Exceed XP 8318ML + 20 wt% T30S; 80 wt% Exceed XP 8318ML + 20 wt% ICP7032; and 80 wt% Exceed XP 8318ML + 20 wt% HTA 108, based on the weight of the monolayer film. ICP7032 is ExxonMobil purchased from ExxonMobil Chemical Company, Houston, TX. TM PP7032E3.

[0134] Table 1

[0135]

[0136] in:

[0137] A means comparison with pure Exceed XP 8318ML;

[0138] B represents the comparison with the combination of 80wt% Exceed XP 8318ML+20wt% HTA 108.

[0139] From Table 1, it can be seen that compared with adding 20wt% of high-density polyethylene HTA 108, adding 20wt% of homopolypropylene T30S increases the MD 1% secant modulus by 31.6%, and at the same time, the dart impact strength / thickness (g / μm) and needle punch strength (mN / μm) are significantly increased by 74% and 20.5%, respectively. This shows that using homopolypropylene instead of high-density polyethylene significantly improves the stiffness and toughness of the film.

[0140] From Table 1, it can be seen that compared with adding 20wt% of high-density polyethylene HTA 108, adding 20wt% of polypropylene impact copolymer ICP7032, although the MD 1% secant modulus slightly decreased (decreased by about 10.2%), the dart impact strength / thickness (g / μm) and needle punch strength (mN / μm) were significantly increased by 256% and 19.4%, respectively. This shows that using polypropylene impact copolymer instead of high-density polyethylene significantly improves the toughness of the film while maintaining basically the same stiffness.

[0141] Example 2

[0142] Table 2 compares the various properties of the following monolayer films of different compositions: pure EXT 515; 80 wt% EXT 515 + 20 wt% T30S; 80 wt% EXT 515 + 20 wt% ICP7032; and 80 wt% EXT 515 + 20 wt% HTA108, based on the weight of the monolayer film. ICP7032 is an ExxonMobil TM PP7032E3.

[0143] Table 2

[0144]

[0145] in:

[0146] A indicates comparison with pure EXT 515;

[0147] B represents the comparison with the combination of 80wt% EXT 515+20wt% HTA 108.

[0148] From Table 2, it can be seen that compared with adding 20wt% of high-density polyethylene HTA 108, adding 20wt% of homopolypropylene T30S increases the MD 1% secant modulus by 37.4%, while maintaining the needle punch strength (mN / μm) substantially the same, and significantly increases the dart impact strength / thickness (g / μm) by 62.4%. This shows that using homopolypropylene instead of high-density polyethylene significantly improves the stiffness and toughness of the film at the same time.

[0149] From Table 2, it can be seen that compared with adding 20wt% of high-density polyethylene HTA 108, adding 20wt% of polypropylene impact copolymer ICP7032 maintains the MD 1% secant modulus basically the same (decreased by 0.74%), while the dart impact strength / thickness (g / μm) and needle punch strength (mN / μm) are significantly increased by 132% and 2.0%, respectively. This shows that using polypropylene impact copolymer instead of high-density polyethylene significantly improves toughness while maintaining basically the same stiffness.

[0150] All documents described herein, including any priority documents and / or test procedures are introduced for reference under all jurisdictions that do not conflict with the present invention. It is obvious from the above overview and specific embodiments that, although the form of the present disclosure has been illustrated and described, various modifications can be made without departing from the spirit and scope of the present disclosure. Therefore, it is not desired that the present disclosure be limited in this way. Similarly, the term "comprising" is considered to be synonymous with the term "including". Similarly, whenever a composition, element or element group is in front of the transitional term "comprising", it should be understood that it is also considered to have the transitional term "essentially consisting of", "consisting of", "selected from" or "being" in front of the listed composition, element or each element The same composition or element group, and vice versa.

[0151] For simplicity, only some numerical ranges are clearly disclosed herein. However, a certain lower limit can be used in combination with any other upper limit to limit the scope that is not clearly recorded. Similarly, a certain lower limit can be used in combination with any other lower limit to limit the scope that is not clearly recorded. Similarly, a certain upper limit can also be used in combination with any upper limit to limit the scope that is not clearly recorded. In addition, even if there is no clear description, each point or individual value between the two end points is also included in the scope. Therefore, each point or individual value itself can be used as a lower limit or upper limit in combination with other points or individual values ​​or other lower or upper limits to limit the scope that is not clearly recorded.

Claims

1. A polyolefin composition comprising from about 60 wt % to about 95 wt % of BOCD polyethylene and from about 5 wt % to about 40 wt % of polypropylene, based on the weight of the polyolefin composition, wherein the BOCD polyethylene contains from about 70 mol % to about 99 mol % of polymer units derived from ethylene, based on the total moles of polymer units of the BOCD polyethylene, and has a density of about 0.91 g / cm 3 To about 0.925g / cm 3 , which is measured according to ASTM D-792 or ASTM D-1505, and a melt index (MI, or I 2.16 ), which is measured according to ASTM D-1238-E (190°C / 2.16kg), and the BOCD polyethylene has a composition distribution breadth index (CDBI) from about 25 wt% to about 55 wt%, The polypropylene is selected from the group consisting of a homopolymer of polypropylene, an impact copolymer of polypropylene, and a combination thereof, wherein the homopolymer of polypropylene has a melt index of from about 1 g / 10 min to about 6 g / 10 min as measured according to ASTM D1238-L (230° C. / 2.16 kg), and The impact copolymer of the polypropylene has a melt index of from about 1 g / 10 min to about 6 g / 10 min as measured according to ASTM D1238-L (230° C. / 2.16 kg).

2. The polyolefin composition according to claim 1, wherein the homopolymer of polypropylene has one or more of the following properties: (1) From about 0.8 g / cm 3 To about 0.98g / cm 3 A density of , as determined in accordance with ASTM D792-13; and (2) A tensile strength at yield of from about 20 MPa to about 100 MPa as measured in accordance with ASTM D638.

3. The polyolefin composition according to any one of claims 1 to 2, wherein the impact copolymer of polypropylene has one or more of the following properties: (1) From about 0.8 g / cm 3 To about 0.98g / cm 3 A density of , as determined in accordance with ASTM D792-13; and (2) A tensile strength at yield of from about 10 MPa to about 100 MPa as measured in accordance with ASTM D638.

4. The polyolefin composition according to any one of claims 1 to 3, wherein the polyolefin composition has a machine direction (MD) 1% secant modulus from greater than about 200 MPa to less than about 410 MPa, measured when a film comprising the polyolefin composition has a thickness of about 25 μm, wherein the machine direction (MD) 1% secant modulus is measured according to ASTM D 882 method.

5. The polyolefin composition according to any one of claims 1 to 4, wherein the polyolefin composition comprising the polypropylene has a dart drop impact strength / thickness value (g / μm) that is substantially the same, or from greater than about 10% to less than about 260%, as compared to an otherwise identical polyolefin composition in which the polypropylene is replaced with a high density polyethylene, wherein the dart drop impact strength is measured according to the ASTM D1709 method, wherein the high density polyethylene (HDPE) has a value greater than 0.940 g / cm 3 and a melt index of about 0.5 g / 10 min to about 10 g / 10 min, wherein the density is measured according to ASTM D-1505 and the melt index is measured according to ASTM D1238-E (190° C. / 2.16 kg).

6. The polyolefin composition according to any one of claims 1 to 5, wherein the polyolefin composition comprising the polypropylene has a needle punch strength value (mN / μm) that is substantially the same, or from greater than about 4% to less than about 30%, compared to an otherwise identical polyolefin composition in which the polypropylene is replaced with a high density polyethylene, wherein the needle punch strength is measured according to the CEN 14477 method, wherein the high density polyethylene (HDPE) has a value of greater than 0.940 g / cm 3 and a melt index of about 0.5 g / 10 min to about 10 g / 10 min, wherein the density is measured according to ASTM D-1505 and the melt index is measured according to ASTM D1238-E (190° C. / 2.16 kg).

7. A polyolefin composition comprising from about 60 wt % to about 95 wt % of BOCD polyethylene and from about 5 wt % to about 40 wt % of polypropylene, based on the weight of the polyolefin composition, wherein the BOCD polyethylene contains from about 70 mol % to about 99 mol % of polymer units derived from ethylene, based on the total moles of polymer units of the BOCD polyethylene, and has a density of about 0.918 g / cm 3 , which is measured according to ASTM D-792, and a melt index (MI, or I 2.16 ), which is measured according to ASTM D-1238-E (190°C / 2.16 kg), and the BOCD polyethylene has a composition distribution breadth index (CDBI) of about 38.6 wt%, or wherein the BOCD polyethylene contains from about 70 mol % to about 99 mol % of polymer units derived from ethylene, based on the total moles of polymer units of the BOCD polyethylene, and has a density of about 0.915 g / cm 3 , which is measured according to ASTM D1505, and a melt index (MI, or I 2.16 ), which is measured according to ASTM D-1238-E (190°C / 2.16kg), and the BOCD polyethylene has a composition distribution breadth index (CDBI) of about 43 wt%, The polypropylene is selected from the group consisting of a homopolymer of polypropylene, an impact copolymer of polypropylene, and a combination thereof, wherein the homopolymer of polypropylene has a melt index of about 3.2 g / 10 min as measured according to ASTM D1238-L (230° C. / 2.16 kg), and The impact copolymer of the polypropylene has a melt index of about 4.0 g / 10 min, as measured according to ASTM D1238-L (230° C. / 2.16 kg).

8. A film comprising, preferably consisting of, the polyolefin composition according to any one of claims 1 to 7.

9. A film comprising a polyolefin composition, wherein the polyolefin composition comprises from about 60 wt % to about 95 wt % of BOCD polyethylene and from about 5 wt % to about 40 wt % of polypropylene, based on the weight of the polyolefin composition, wherein the BOCD polyethylene contains from about 70 mol % to about 99 mol % of polymer units derived from ethylene, based on the total moles of polymer units of the BOCD polyethylene, and has a density of about 0.91 g / cm 3 To about 0.925g / cm 3 , which is measured according to ASTM D-792 or ASTM D-1505, and a melt index (MI, or I 2.16 ), which is measured according to ASTM D-1238-E (190°C / 2.16kg), and the BOCD polyethylene has a composition distribution breadth index (CDBI) from about 25 wt% to about 55 wt%, The polypropylene is selected from the group consisting of a homopolymer of polypropylene, an impact copolymer of polypropylene, and a combination thereof, wherein the homopolymer of polypropylene has a melt index of from about 1 g / 10 min to about 6 g / 10 min, as measured according to ASTM D1238-L (230° C. / 2.16 kg), wherein the impact copolymer of polypropylene has a melt index of from about 1 g / 10 min to about 6 g / 10 min as measured according to ASTM D1238-L (230° C. / 2.16 kg), and wherein the film has a machine direction (MD) 1% secant modulus from greater than about 200 MPa to less than about 410 MPa, measured when the film comprising the polyolefin composition has a thickness of about 25 μm, wherein the machine direction (MD) 1% secant modulus is measured according to ASTM D 882 method.

10. The film according to claim 9, wherein the film comprising polypropylene has a dart drop impact strength / thickness value (g / μm) that is substantially the same, or from greater than about 10% to less than about 260%, as compared to an otherwise identical film in which the polypropylene is replaced with a high density polyethylene, wherein the dart drop impact strength is measured according to the ASTM D 1709 method, wherein the high density polyethylene (HDPE) has a value greater than 0.940 g / cm 3 and a melt index of about 0.5 g / 10 min to about 10 g / 10 min, wherein the density is measured according to ASTM D-1505 and the melt index is measured according to ASTM D1238-E (190° C. / 2.16 kg).

11. The film according to any one of claims 9 to 10, wherein the film comprising polypropylene has a needle punch strength value (mN / μm) that is substantially the same, or from greater than about 4% to less than about 30%, compared to an otherwise identical film in which the polypropylene is replaced with a high density polyethylene, wherein the needle punch strength is measured according to the CEN 14477 method, wherein the high density polyethylene (HDPE) has a value of greater than 0.940 g / cm 3 and a melt index of about 0.5 g / 10 min to about 10 g / 10 min, wherein the density is measured according to ASTM D-1505 and the melt index is measured according to ASTM D1238-E (190° C. / 2.16 kg).

12. A film comprising a polyolefin composition, wherein the polyolefin composition comprises from about 60 wt % to about 95 wt % of BOCD polyethylene and from about 5 wt % to about 40 wt % of polypropylene, based on the weight of the polyolefin composition, wherein the BOCD polyethylene contains from about 70 mol % to about 99 mol % of polymer units derived from ethylene, based on the total moles of polymer units of the BOCD polyethylene, and has a density of about 0.918 g / cm 3 , which is measured according to ASTM D-792, and a melt index (MI, or I 2.16 ), which is measured according to ASTM D-1238-E (190°C / 2.16 kg), and the BOCD polyethylene has a composition distribution breadth index (CDBI) of about 38.6 wt%, or wherein the BOCD polyethylene contains from about 70 mol % to about 99 mol % of polymer units derived from ethylene, based on the total moles of polymer units of the BOCD polyethylene, and has a density of about 0.915 g / cm 3 , which is measured according to ASTM D1505, and a melt index (MI, or I 2.16 ), which is measured according to ASTM D-1238-E (190°C / 2.16kg), and the BOCD polyethylene has a composition distribution breadth index (CDBI) of about 43 wt%, The polypropylene is selected from the group consisting of a homopolymer of polypropylene, an impact copolymer of polypropylene, and a combination thereof, wherein the homopolymer of polypropylene has a melt index of about 3.2 g / 10 min as measured according to ASTM D1238-L (230° C. / 2.16 kg), and wherein the impact copolymer of polypropylene has a melt index of about 4.0 g / 10 min as measured according to ASTM D1238-L (230° C. / 2.16 kg); and wherein the film has a machine direction (MD) 1% secant modulus from greater than about 200 MPa to less than about 410 MPa, measured when the film comprising the polyolefin composition has a thickness of about 25 μm, wherein the machine direction (MD) 1% secant modulus is measured according to ASTM D 882 method.

13. The method for producing a film according to any one of claims 8 to 12, produced by a casting method.

14. A package comprising a film according to any one of claims 8 to 12, for example selected from food packaging and industrial packaging.

Images