Olefin polymer, film produced therefrom, and method for producing the same

Abstract

The present invention relates to olefin polymers, films produced therefrom, and methods for producing the same. The olefin polymers according to specific embodiments of the present invention exhibit excellent processability, and films produced therefrom, particularly linear low-density polyethylene films, exhibit excellent mechanical strength and heat-sealing properties, particularly low-temperature heat-sealing properties.

Description

Technical Field

[0001] The present invention relates to olefin polymers, films produced therefrom, and methods for producing the same. Specifically, the present invention relates to olefin polymers having excellent processability, olefin polymer films produced therefrom and having excellent heat seal strength, particularly low-temperature heat seal strength, and methods for producing the same. Background Art

[0002] Metallocene catalysts, one of the catalysts used for olefin polymerization, are compounds composed of ligands such as cyclopentadienyl, indenyl, or cycloheptadienyl coordinated to transition metals or transition metal halides, and have a basic sandwich structure.

[0003] Ziegler-Natta catalysts, another catalyst used for olefin polymerization, have active sites (i.e., metal components) dispersed on an inert solid surface, resulting in heterogeneous properties. In contrast, metallocene catalysts are compounds with a fixed structure, and therefore are known as single-site catalysts, where all active sites exhibit identical polymerization characteristics. Polymers polymerized using these metallocene catalysts have a narrow molecular weight distribution and a uniform distribution of comonomers, resulting in higher copolymerization activity than Ziegler-Natta catalysts.

[0004] On the other hand, linear low-density polyethylene (LLDPE) is produced by copolymerizing ethylene and alpha-olefins under low pressure using a polymerization catalyst. It has a narrow molecular weight distribution, short chain branches (SCB) of fixed length, and generally lacks long chain branches (LCB). Films made from LLDPE not only possess the properties of conventional polyethylene but also have high breaking strength and elongation, as well as excellent tear strength and impact strength. Therefore, it is widely used in stretch films and cover films, where existing low-density polyethylene (LDPE) or high-density polyethylene (HDPE) is difficult to use.

[0005] However, linear low-density polyethylene produced using a metallocene catalyst has a narrow molecular weight distribution, which reduces processability, and films produced therefrom tend to have reduced heat-sealing properties.

[0006] Therefore, there is a demand for olefin polymers that are excellent in processability and can produce films having excellent mechanical strength and heat-sealing properties, particularly low-temperature heat-sealing properties. Summary of the Invention

[0007] An object of the present invention is to provide an olefin-based polymer having excellent processability and capable of producing an olefin-based polymer film having excellent mechanical strength and heat-sealing properties, particularly low-temperature heat-sealing properties.

[0008] Another object of the present invention is to provide an olefin polymer film produced from the above-mentioned olefin polymer and having excellent mechanical strength and heat-sealing properties, especially low-temperature heat-sealing properties.

[0009] Another object of the present invention is to provide a method for producing the above-mentioned olefin-based polymer and olefin-based polymer film.

[0010] According to a specific embodiment of the present invention, an olefin polymer is provided, wherein the density of the olefin polymer (1) is 0.910 to 0.940 g / cm 3 , preferably 0.910~0.925g / cm 3 (2) Melt index (I) measured at 190°C with a load of 2.16 kg 2.16 ) is 0.5 to 2.0 g / 10 minutes, preferably 0.8 to 1.5 g / 10 minutes; (3) the melt index (I 21.6 ) and the melt index (I 2.16 ) ratio (melt flow ratio; MFR) is 20 to 60, preferably 20 to 50; (4) the comonomer distribution slope (comonomer distribution slope; CDS) defined by the following mathematical formula 1 is 3 or more, preferably 3 to 15.

[0011] [Mathematical formula 1]

[0012] Among them, C 20 and C 80 is the comonomer content at the points where the cumulative weight fraction in the comonomer distribution is 20% and 80%, respectively, and M 20 and M 80 are the molecular weights at the points where the cumulative mass fractions of the comonomer distribution are 20% and 80%, respectively.

[0013] In a specific example of the present invention, the above-mentioned olefin-based polymer can be produced by polymerizing olefin-based monomers in the presence of a composite catalyst, wherein the above-mentioned composite catalyst comprises at least one first transition metal compound represented by the following chemical formula 1; and at least one second transition metal compound selected from the compound represented by the following chemical formula 2 and the compound represented by the following chemical formula 3.

[0014] [Chemical Formula 1]

[0015] [Chemical Formula 2]

[0016] [Chemical Formula 3]

[0017] In the above Chemical Formulas 1 to 3, M1 and M2 are different from each other and are each independently titanium (Ti), zirconium (Zr), or hafnium (Hf).

[0018] X is independently halogen, C 1-20 Alkyl, C 2-20 Alkenyl, C 2-20 Alkynyl, C 6-20 Aryl, C 1-20 Alkyl C 6-20 Aryl, C 6-20 Aryl C 1-20 Alkyl, C 1-20 Alkylamide or C 6-20 Arylamide,

[0019] R1 to R 10 are each independently hydrogen, substituted or unsubstituted C 1-20 Alkyl, substituted or unsubstituted C 2-20 Alkenyl, substituted or unsubstituted C 6-20 Aryl, substituted or unsubstituted C 1-20 Alkyl C 6-20 Aryl, substituted or unsubstituted C 6-20 Aryl C 1-20 Alkyl, substituted or unsubstituted C 1-20 Heteroalkyl, substituted or unsubstituted C 3-20 Heteroaryl, substituted or unsubstituted C 1-20 Alkylamide, substituted or unsubstituted C 6-20 Arylamide, substituted or unsubstituted C 1-20 Alkylene, or substituted or unsubstituted C 1-20 silyl, and R1 to R 10 Each independently connects adjacent groups to form a substituted or unsubstituted saturated or unsaturated C 4-20 ring.

[0020] In a specific embodiment of the present invention, M1 and M2 are different from each other and are each zirconium or hafnium, and X is each halogen or C 1-20 Alkyl, R1 to R 10 Each may be hydrogen, substituted or unsubstituted C 1-20 Alkyl, substituted or unsubstituted C 1-20 Alkenyl, or substituted or unsubstituted C 6-20 Aryl.

[0021] In a preferred embodiment of the present invention, M1 is hafnium, M2 is zirconium, and X can be chlorine or methyl.

[0022] In a preferred embodiment of the present invention, the first transition metal compound may be at least one of the transition metal compounds represented by the following chemical formulas 1-1 and 1-2, and the second transition metal compound may be at least one of the transition metal compounds represented by the following chemical formulas 2-1, 2-2 and 3-1.

[0023] In the above chemical formula, Me is a methyl group.

[0024] In a specific example of the present invention, the molar ratio of the first transition metal compound to the second transition metal compound is in the range of 100:1 to 1:100.

[0025] In a specific example of the present invention, the catalyst may include at least one co-catalyst selected from the group consisting of the compound represented by the following Chemical Formula 4, the compound represented by the following Chemical Formula 5, and the compound represented by the following Chemical Formula 6.

[0026] [Chemical Formula 4]

[0027] [Chemical Formula 5]

[0028] [Chemical Formula 6]

[0029] [LH] + [Z(A)4] - or [L] + [Z(A)4] -

[0030] In the above chemical formula 4, n is an integer greater than 2, R a Halogen atoms, C 1-20 Hydrocarbon, or halogen-substituted C 1-20 Hydrocarbon group,

[0031] In the above chemical formula 5, D is aluminum (Al) or boron (B), R b 、R c and R d are each independently a halogen atom, C 1-20 Hydrocarbon, halogen-substituted C 1-20 Hydrocarbon, or C 1-20 Alkoxy,

[0032] In the above chemical formula 6, L is a neutral or cationic Lewis base, [LH] + and [L] + is a Bronsted acid, Z is a Group 13 element, and A is independently a substituted or unsubstituted C 6-20 Aryl, or substituted or unsubstituted C 1-20 alkyl.

[0033] In a specific example of the present invention, the catalyst may further include a carrier supporting a transition metal compound, a co-catalyst compound, or both.

[0034] In a preferred embodiment of the present invention, the support may include at least one selected from silicon oxide, aluminum oxide, and magnesium oxide.

[0035] The total amount of the composite transition metal compound supported on the carrier is 0.001 to 1 mmole based on 1 g of the carrier, and the total amount of the co-catalyst compound supported on the carrier is 2 to 15 mmole based on 1 g of the carrier.

[0036] In a specific example of the present invention, the olefin polymer is a copolymer of an olefin monomer and an olefin comonomer. Specifically, the olefin monomer is ethylene, and the olefin comonomer can be at least one selected from propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, and 1-hexadecene. Preferably, the olefin polymer is a linear low-density polyethylene in which the olefin monomer is ethylene and the olefin comonomer is 1-hexene.

[0037] According to a specific embodiment of the present invention, a method for producing an olefin-based polymer is provided, comprising the steps of polymerizing an olefin-based monomer in the presence of a composite catalyst to obtain an olefin-based polymer, wherein the composite catalyst comprises at least one first transition metal compound represented by the above chemical formula 1; and at least one second transition metal compound selected from the group consisting of a compound represented by the above chemical formula 2 and a compound represented by the above chemical formula 3, and wherein the density (1) of the olefin-based polymer is 0.910 to 0.940 g / cm 3 , preferably 0.910~0.925g / cm 3 (2) Melt index (I) measured at 190°C with a load of 2.16 kg 2.16 ) is 0.5 to 2.0 g / 10 minutes, preferably 0.8 to 1.5 g / 10 minutes; (3) the melt index (I 21.6 ) and the melt index (I 2.16 ) ratio (melt flow ratio; MFR) is 20 to 60, preferably 20 to 50; (4) the comonomer distribution slope (comonomer distribution slope; CDS) defined by the above mathematical formula 1 is 3 or more, preferably 3 to 15.

[0038] In a specific example of the present invention, the polymerization of the olefinic monomers can be carried out by gas phase polymerization. Specifically, the polymerization of the olefinic monomers can be carried out in a gas phase fluidized bed reactor.

[0039] According to a specific example of the present invention, an olefin-based polymer film is provided, which is made from the above-mentioned olefin-based polymer. The heat seal strength of the olefin-based polymer film measured under the conditions of 0.2 bar, 1.5 seconds and 130°C is 30 gf / 2.5 cm or more, preferably 30 to 150 gf / 2.5 cm; the heat seal strength measured under the conditions of 0.2 bar, 1.5 seconds and 135°C is 150 gf / 2.5 cm or more, preferably 150 to 210 gf / 2.5 cm; the hot tack strength at 100°C is 0.45 N / 2 cm or more, preferably 0.45 to 2.5 N / 2 cm; and the hot tack strength at 110°C is 3.45 N / 2 cm or more, preferably 3.45 to 3.57 N / 2 cm.

[0040] In a specific example of the present invention, the film may be at least one selected from a stretch film, a mulch film, a laminate film, a silage film, and an agricultural film.

[0041] According to a specific example of the present invention, a method for producing an olefin-based polymer film is provided, comprising the following steps: (a) polymerizing an olefin-based monomer in the presence of a composite catalyst to obtain an olefin-based polymer; and (b) molding the olefin-based polymer to obtain a film, wherein the composite catalyst comprises at least one first transition metal compound represented by the above-mentioned Chemical Formula 1; and at least one second transition metal compound selected from the compound represented by the above-mentioned Chemical Formula 2 and the compound represented by the above-mentioned Chemical Formula 3, and the olefin-based polymer film has a heat seal strength (heat seal strength) measured under the conditions of 0.2 bar, 1.5 seconds and 130° C. of 30 gf / 2.5 cm or more, preferably 30 to 150 gf / 2.5 cm, a heat seal strength measured under the conditions of 0.2 bar, 1.5 seconds and 135° C. of 150 gf / 2.5 cm or more, preferably 150 to 210 gf / 2.5 cm, and a hot tack strength (hot tack strength) at 100° C. The thermal adhesive strength is 0.45 N / 2 cm or more, preferably 0.45 to 2.5 N / 2 cm, and the hot tack strength at 110° C. is 3.45 N / 2 cm or more, preferably 3.45 to 3.57 N / 2 cm.

[0042] The olefin polymer according to the embodiment of the present invention has excellent processability, and films produced therefrom, particularly linear low-density polyethylene films, have excellent mechanical strength and heat-sealing properties, particularly low-temperature heat-sealing properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a GPC-FTIR chart for explaining the method for measuring CDS defined by Mathematical Formula 1.

[0044] Figures 2 to 6 These are GPC-FTIR charts for CDS measurement of olefin-based polymers in Examples 1 to 5, respectively.

[0045] Figure 7 and 8 These are GPC-FTIR charts for CDS measurement of olefin-based polymers in Comparative Examples 1 and 2, respectively.

[0046] Figure 9 : is a graph showing the heat seal strength of Examples 1 to 55 and Comparative Examples 1 and 2.

[0047] Figure 10 Graph showing the hot tack strength of Examples 1 to 55 and Comparative Examples 1 and 2. DETAILED DESCRIPTION

[0048] Hereinafter, the present invention will be described in more detail.

[0049] Olefin polymers

[0050] According to a specific embodiment of the present invention, an olefin polymer is provided, wherein the density of the olefin polymer (1) is 0.910 to 0.940 g / cm 3 (2) Melt index (I) measured at 190°C with a load of 2.16 kg 2.16 ) is 0.5 to 2.0 g / 10 minutes; (3) the melt index (I 21.6 ) and the melt index (I 2.16 ) ratio (melt flow ratio; MFR) is 20 to 60; (4) the comonomer distribution slope (comonomer distribution slope; CDS) defined by the following mathematical formula 1 is 3 or more.

[0051] In a specific embodiment of the present invention, the density of the olefin polymer is 0.910 to 0.940 g / cm 3 Preferably, the density of the olefin polymer can be 0.910 to 0.925 g / cm 3 .

[0052] In a specific example of the present invention, the melt index (I 2.16) is 0.5 to 2.0 g / 10 minutes. Preferably, the melt index of the olefin polymer measured at 190° C. with a load of 2.16 kg may be 0.8 to 1.5 g / 10 minutes.

[0053] In a specific example of the present invention, the melt index (I 21.6 ) and the melt index (I 2.16 ) ratio (melt flow ratio; MFR) is 20 to 60. Preferably, the MFR of the olefin-based polymer may be 20 to 50.

[0054] In a specific example of the present invention, the comonomer distribution slope (CDS) of the olefinic polymer, as defined by the following mathematical formula 1, is 3 or greater. Preferably, the CDS of the olefinic polymer may be 3-15.

[0055] [Mathematical formula 1]

[0056] In the above mathematical formula 1, C 20 and C 80 is the comonomer content at the points where the cumulative weight fraction in the comonomer distribution is 20% and 80%, respectively, and M 20 and M 80 are the molecular weights at the points where the cumulative mass fractions of the comonomer distribution are 20% and 80%, respectively.

[0057] The CDS of an olefin polymer represents the slope of the comonomer content relative to molecular weight at the 20% and 80% cumulative mass fraction points on a comonomer distribution chart. A higher CDS indicates a greater concentration of high molecular weight chains in the copolymer, resulting in superior mechanical strength and heat-sealing properties.

[0058] The comonomer distribution of olefin polymers can be continuously measured along with the molecular weight and molecular weight distribution of the polymer using a GPC-FTIR device.

[0059] In a specific example of the present invention, an olefin-based polymer can be produced by polymerizing an olefin-based monomer in the presence of a composite catalyst, wherein the composite catalyst comprises at least one first transition metal compound represented by the following chemical formula 1; and at least one second transition metal compound selected from a compound represented by the following chemical formula 2 and a compound represented by the following chemical formula 3.

[0060] [Chemical Formula 1]

[0061] [Chemical Formula 2]

[0062] [Chemical Formula 3]

[0063] In the above Chemical Formulas 1 to 3, M1 and M2 are different from each other and are each independently titanium (Ti), zirconium (Zr), or hafnium (Hf). Specifically, M1 and M2 are different from each other and can each be zirconium or hafnium. Preferably, M1 is hafnium and M2 can be zirconium.

[0064] X is independently halogen, C 1-20 Alkyl, C 2-20 Alkenyl, C 2-20 Alkynyl, C 6-20 Aryl, C 1-20 Alkyl C 6-20 Aryl, C 6-20 Aryl C 1-20 Alkyl, C 1-20 Alkylamide or C 6-20 Specifically, X can be halogen or C 1-20 Preferably, X can be chlorine or methyl.

[0065] R1 to R 10 are each independently hydrogen, substituted or unsubstituted C 1-20 Alkyl, substituted or unsubstituted C 2-20 Alkenyl, substituted or unsubstituted C 6-20 Aryl, substituted or unsubstituted C 1-20 Alkyl C 6-20 Aryl, substituted or unsubstituted C 6-20 Aryl C 1-20 Alkyl, substituted or unsubstituted C 1-20 Heteroalkyl, substituted or unsubstituted C 3-20 Heteroaryl, substituted or unsubstituted C 1-20 Alkylamide, substituted or unsubstituted C 6-20 Arylamide, substituted or unsubstituted C 1-20 Alkylene, or substituted or unsubstituted C 1-20 Silyl, wherein R1 to R 10 Each independently connects adjacent groups to form a substituted or unsubstituted saturated or unsaturated C 4-20 Specifically, R1 to R 10 Each may be hydrogen, substituted or unsubstituted C 1-20 Alkyl, substituted or unsubstituted C 1-20 Alkenyl, or substituted or unsubstituted C 6-20 Aryl.

[0066] In a specific embodiment of the present invention, M1 and M2 are different from each other and are each zirconium or hafnium, and X is each halogen or C1-20 Alkyl, R1 to R 10 Each may be hydrogen, substituted or unsubstituted C 1-20 Alkyl, substituted or unsubstituted C 1-20 Alkenyl, or substituted or unsubstituted C 6-20 Aryl.

[0067] In a preferred embodiment of the present invention, M1 is hafnium, M2 is zirconium, and X can be chlorine or methyl.

[0068] In a preferred embodiment of the present invention, the first transition metal compound is at least one of the transition metal compounds represented by the following chemical formulas 1-1 and 1-2, and the second transition metal compound can be at least one of the transition metal compounds represented by the following chemical formulas 2-1, 2-2 and 3-1.

[0069] In the above chemical formula, Me is a methyl group.

[0070] In a specific example of the present invention, the molar ratio of the first transition metal compound to the second transition metal compound is in the range of 100:1 to 1:100. Preferably, the molar ratio of the first transition metal compound to the second transition metal compound is in the range of 50:1 to 1:50. Preferably, the molar ratio of the first transition metal compound to the second transition metal compound is in the range of 10:1 to 1:10.

[0071] In a specific example of the present invention, the catalyst may include at least one co-catalyst compound selected from the group consisting of the compound represented by the following Chemical Formula 4, the compound represented by the following Chemical Formula 5, and the compound represented by the following Chemical Formula 6.

[0072] [Chemical Formula 4]

[0073] In the above chemical formula 4, n is an integer greater than 2, R a It can be a halogen atom, C 1-20 Hydrocarbons, or C substituted by halogen 1-20 Hydrocarbons. Specifically, R a It may be methyl, ethyl, n-butyl or isobutyl.

[0074] [Chemical Formula 5]

[0075] In the above chemical formula 5, D is aluminum (Al) or boron (B), R b 、R c and R d are each independently a halogen atom, C 1-20 Hydrocarbon, halogen-substituted C 1-20 Hydrocarbon, or C 1-20 Specifically, when D is aluminum (Al), R b 、R cand R d Each independently can be methyl or isobutyl, when D is boron (B), R b 、R c and R d Each may be a pentafluorophenyl group.

[0076] [Chemical Formula 6]

[0077] [LH] + [Z(A)4] - or [L] + [Z(A)4] -

[0078] In the above chemical formula 6, L is a neutral or cationic Lewis base, [LH] + and [L] + is a Bronsted acid, Z is a Group 13 element, and A is independently a substituted or unsubstituted C 6-20 Aryl, or substituted or unsubstituted C 1-20 Specifically, [LH] + It can be a dimethylanilinium cation, [Z(A)4] - It can be [B(C6F5)4] - , [L] + It can be [(C6H5)3C] + .

[0079] Specifically, examples of the compound represented by the above Chemical Formula 4 include methylaluminoxane, ethylaluminoxane, isobutylaluminoxane, butylaluminoxane, and the like, preferably methylaluminoxane, but not limited thereto.

[0080] Examples of the compound represented by Chemical Formula 5 include trimethylaluminum, triethylaluminum, triisobutylaluminum, tripropylaluminum, tributylaluminum, dimethylaluminum chloride, triisopropylaluminum, tri-sec-butylaluminum, tricyclopentylaluminum, tripentylaluminum, triisopentylaluminum, trihexylaluminum, trioctylaluminum, ethyldimethylaluminum, methyldiethylaluminum, triphenylaluminum, tri-p-tolylaluminum, dimethylaluminum methoxide, dimethylaluminum ethoxide, trimethylboron, triethylboron, triisobutylboron, tripropylboron, and tributylboron. Preferred examples include trimethylaluminum, triethylaluminum, and triisobutylaluminum, but not limited thereto.

[0081] Examples of the compound represented by the above Chemical Formula 6 include triethylammonium tetraphenylboron, tributylammonium tetraphenylboron, trimethylammonium tetraphenylboron, tripropylammonium tetraphenylboron, trimethylammonium tetra(p-tolyl)boron, trimethylammonium tetra(o-, p-dimethylphenyl)boron, tributylammonium tetra(p-trifluoromethylphenyl)boron, trimethylammonium tetra(p-trifluoromethylphenyl)boron, tributylammonium tetra(pentafluorophenyl)boron, N,N-diethylanilinium tetraphenylboron, N,N-diethylanilinium tetra(pentafluorophenyl)boron, diethylammonium tetra(pentafluorophenyl)boron, triphenyltetraphenylboron, trimethyltetraphenylboron, triethylammonium tetraphenylaluminum, tributylammonium tetraphenylaluminum, trimethylammonium tetraphenylaluminum, and tripropylammonium tetraphenylboron. Aluminum, trimethylammonium tetra(p-tolyl)aluminum, tripropylammonium tetra(p-tolyl)aluminum, triethylammonium tetra(o-, p-dimethylphenyl)aluminum, tributylammonium tetra(p-trifluoromethylphenyl)aluminum, trimethylammonium tetra(p-trifluoromethylphenyl)aluminum, tributylammonium tetra(pentafluorophenyl)aluminum, N,N-diethylanilinium tetraphenylaluminum, N,N-diethylanilinium tetra(pentafluorophenyl)aluminum, diethylammonium tetra(pentafluorophenyl)aluminum, triphenyltetraphenylaluminum, trimethyltetraphenylaluminum, tripropylammonium tetra(p-tolyl)boron, triethylammonium tetra(o-, p-dimethylphenyl)boron, tributylammonium tetra(p-trifluoromethylphenyl)boron, triphenylcarbon tetra(p-trifluoromethylphenyl)boron, triphenylcarbon tetra(pentafluorophenyl)boron, etc.

[0082] In a specific example of the present invention, the catalyst may further comprise a carrier supporting a transition metal compound, a co-catalyst compound, or both. Specifically, the carrier may support both the transition metal compound and the co-catalyst compound.

[0083] At this time, the carrier may include a substance containing a hydroxyl group on the surface. Preferably, a substance having a hydroxyl group and a siloxane group that has been dried and the surface has been dehydrated and that is highly reactive can be used. For example, the carrier may include at least one selected from silicon oxide, aluminum oxide, and magnesium oxide. Specifically, silicon oxide, silicon oxide-aluminum oxide, and silicon oxide-magnesium oxide, etc., dried at high temperatures, may be used as carriers. These may typically contain oxides, carbonates, sulfates, and nitrate components such as Na2O, K2CO3, BaSO4, and Mg(NO3)2. In addition, they may also include carbon, zeolite, magnesium chloride, etc. However, the carrier is not limited thereto and is not particularly limited as long as it can support transition metal compounds and co-catalyst compounds.

[0084] The average particle size of the carrier may be 10 to 250 μm, preferably, the average particle size may be 10 to 150 μm, and more preferably, the average particle size may be 20 to 100 μm.

[0085] The micropore volume of the carrier may be 0.1 to 10 cc / g, preferably 0.5 to 5 cc / g, and more preferably 1.0 to 3.0 cc / g.

[0086] The specific surface area of ​​the carrier can be 1 to 1000 m 2 / g, preferably 100 to 800 m 2 / g, more preferably 200 to 600 m 2 / g.

[0087] In a preferred embodiment of the present invention, the carrier can be silicon oxide. In this case, the drying temperature of the silicon oxide can be 200-900°C. The drying temperature is preferably 300-800°C, and more preferably 400-700°C. If the drying temperature is less than 200°C, excessive moisture may occur, causing the surface moisture to react with the co-catalyst compound. If the drying temperature is greater than 900°C, the carrier structure may disintegrate.

[0088] The concentration of hydroxyl groups in the dried silica can be 0.1 to 5 mmole / g, preferably 0.7 to 4 mmole / g, and more preferably 1.0 to 2 mmole / g. If the concentration of hydroxyl groups is less than 0.1 mmole / g, the amount of the co-catalyst compound supported will be low, while if it is greater than 5 mmole / g, deactivation of the catalyst components may occur.

[0089] The total amount of the transition metal compound supported on the carrier can be 0.001 to 1 mmole based on 1 g of the carrier. When the ratio of the transition metal compound to the carrier satisfies the above range, the supported catalyst exhibits appropriate activity, which is advantageous in maintaining catalyst activity and economic efficiency.

[0090] The total amount of the promoter compound supported on the carrier can be 2 to 15 mmole based on 1 g of the carrier. When the ratio of the promoter compound to the carrier satisfies the above range, it is advantageous in terms of maintaining catalyst activity and economic efficiency.

[0091] The carrier may be one or more than one. For example, the transition metal compound and the co-catalyst compound may both be supported on one carrier, or the transition metal compound and the co-catalyst compound may each be supported on two or more carriers. Alternatively, only one of the transition metal compound and the co-catalyst compound may be supported on the carrier.

[0092] As a method for supporting the transition metal compound and / or the co-catalyst compound that can be used in the olefin polymerization catalyst, a physical adsorption method or a chemical adsorption method can be used.

[0093] For example, the physical adsorption method may be a method in which a solution containing a transition metal compound dissolved therein is brought into contact with a carrier and then dried; a method in which a solution containing a transition metal compound and a co-catalyst compound dissolved therein is brought into contact with a carrier and then dried to produce a carrier loaded with the transition metal compound; separately, a solution containing a co-catalyst compound dissolved therein is brought into contact with a carrier and then dried to produce a carrier loaded with the co-catalyst compound; and then the materials are mixed, etc.

[0094] The chemical adsorption method can be a method in which the surface of the carrier is first loaded with a co-catalyst compound and then the co-catalyst compound is loaded with a transition metal compound; or a method in which the functional groups on the surface of the carrier (for example, when using silicon oxide, the hydroxyl groups (-OH) on the surface of silicon oxide) are covalently bonded to the catalyst compound, etc.

[0095] In a specific example of the present invention, the olefin polymer can be a homopolymer of an olefin monomer or a copolymer of an olefin monomer and a comonomer. Preferably, the olefin polymer is a copolymer of an olefin monomer and an olefin comonomer.

[0096] Among them, the olefin monomer can be selected from C 2-20 Alpha-olefins (α-olefin), C 1-20 Diolefins, C 3-20 Cycloolefins and C 3-20 At least one of cyclodiolefins.

[0097] For example, the olefin monomer may be ethylene, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene or 1-hexadecene, and the olefin polymer may be a homopolymer containing only one of the above-mentioned olefin monomers, or may be a copolymer containing two or more of the above-mentioned olefin monomers.

[0098] In an exemplary embodiment, the olefin polymer may be ethylene and C 3-20 The copolymer is formed by copolymerization of alpha-olefins. Preferably, the olefin-based polymer may be a linear low-density polyethylene in which the olefin-based monomer is ethylene and the olefin-based comonomer is 1-hexene.

[0099] In this case, the ethylene content is preferably 55 to 99.9% by weight, more preferably 90 to 99.9% by weight, and the alpha-olefin comonomer content is preferably 0.1 to 45% by weight, more preferably 0.1 to 10% by weight.

[0100] Method for producing olefin polymer

[0101] According to a specific example of the present invention, a method for producing an olefin-based polymer is provided, comprising the steps of polymerizing an olefin-based monomer in the presence of a composite catalyst to obtain an olefin-based polymer, wherein the composite catalyst comprises at least one first transition metal compound represented by the following chemical formula 1; and at least one second transition metal compound selected from a compound represented by the following chemical formula 2 and a compound represented by the following chemical formula 3.

[0102] [Chemical Formula 1]

[0103] [Chemical Formula 2]

[0104] [Chemical Formula 3]

[0105] In the above chemical formula, M1, M2, X and R1 to R 10 Same as the description in the above-mentioned olefin polymer section.

[0106] As described above, the olefin polymer produced by the production method according to one embodiment of the present invention has a density (1) of 0.910 to 0.940 g / cm 3 , preferably 0.910~0.925g / cm 3 (2) Melt index (I) measured at 190°C with a load of 2.16 kg 2.16 ) is 0.5 to 2.0 g / 10 minutes, preferably 0.8 to 1.5 g / 10 minutes; (3) the melt index (I 21.6 ) and the melt index (I 2.16 ) ratio (melt flow ratio; MFR) is 20 to 60, preferably 20 to 50; (4) the comonomer distribution slope (comonomer distribution slope; CDS) defined by the following mathematical formula 1 is 3 or more, preferably 3 to 15.

[0107] [Mathematical formula 1]

[0108] C in the above formula 1 20 、C 80 、M 20 and M 80 Same as the description in the above-mentioned olefin polymer section.

[0109] In specific examples of the present invention, the olefin polymer can be polymerized by, for example, free radical, cationic, coordination, condensation, addition, or other polymerization reactions, but is not limited thereto.

[0110] As one embodiment of the present invention, the olefin polymer can be produced by gas phase polymerization, solution polymerization, or slurry polymerization. Preferably, the polymerization of the olefin monomer can be carried out by gas phase polymerization, specifically, the polymerization of the olefin monomer can be carried out in a gas phase fluidized bed reactor.

[0111] When the olefin polymer is produced by solution polymerization or slurry polymerization, examples of solvents that can be used include C 2+, C 3+, C 4+, C 5+, C 6+, C 7+, C 8+, C 9+, C 10+, C 11+, C 12+, C 13+, C 14+, C 15+, C 16+, C 17+, C 18+, C 19+, C 5-12 Aliphatic hydrocarbon solvents; aromatic hydrocarbon solvents such as toluene and benzene; hydrocarbon solvents substituted with chlorine atoms such as dichloromethane and chlorobenzene; and mixtures thereof, but not limited thereto.

[0112] Olefin polymer films

[0113] According to a specific example of the present invention, an olefin-based polymer film is provided, which is manufactured by molding the above-mentioned olefin-based polymer. The olefin-based polymer film has a heat seal strength of not less than 30 gf / 2.5 cm when measured under the conditions of 0.2 bar, 1.5 seconds and 130°C, a heat seal strength of not less than 150 gf / 2.5 cm when measured under the conditions of 0.2 bar, 1.5 seconds and 135°C, a hot tack strength of not less than 0.45 N / 2 cm at 100°C, and a hot tack strength of not less than 3.45 N / 2 cm at 110°C.

[0114] In a specific embodiment of the present invention, the olefin polymer film has a heat seal strength of 30 gf / 2.5 cm or greater, as measured according to ASTM F88 at 0.2 bar, 1.5 seconds, and 130° C. Preferably, the heat seal strength (130° C.) of the olefin polymer film can be 30 to 150 gf / 2.5 cm.

[0115] In a specific embodiment of the present invention, the olefin polymer film has a heat seal strength of 150 gf / 2.5 cm or greater, as measured according to ASTM F88 at 0.2 bar, 1.5 seconds, and 135° C. Preferably, the heat seal strength (135° C.) of the olefin polymer film can be 150 to 210 gf / 2.5 cm.

[0116] In a specific example of the present invention, the olefin polymer film has a hot tack strength of 0.45 N / 2 cm or more at 100° C. measured according to ASTM F1921. Preferably, the hot tack strength of the olefin polymer film at 100° C. may be 0.45 to 2.5 N / 2 cm.

[0117] In a specific example of the present invention, the olefin polymer film has a hot tack strength of 3.45 N / 2 cm or more at 110° C. measured according to ASTM F1921. Preferably, the hot tack strength of the olefin polymer film at 110° C. may be 3.45 to 3.57 N / 2 cm.

[0118] The olefin polymer film according to a specific embodiment of the present invention comprises the above-mentioned olefin polymer, thereby exhibiting excellent mechanical properties and heat-sealing properties. The above-mentioned olefin polymer has a relatively broad molecular weight distribution, with a relatively large number of short chain branches in the high molecular weight component. Therefore, it is understood that the olefin polymer film produced therefrom exhibits excellent mechanical strength and low-temperature heat-sealing properties.

[0119] In specific examples of the present invention, the olefin polymer film can be effectively used as a stretched film, a cover film, a laminate film, a silage film, an agricultural film, and the like.

[0120] Method for producing olefin polymer film

[0121] According to a specific example of the present invention, a method for producing an olefin-based polymer film is provided, comprising the following steps: (a) polymerizing an olefin-based monomer in the presence of a composite catalyst to obtain an olefin-based polymer; and (b) molding the olefin-based polymer to obtain a film, wherein the composite catalyst comprises at least one first transition metal compound represented by the following Chemical Formula 1; and at least one second transition metal compound selected from the group consisting of a compound represented by the following Chemical Formula 2 and a compound represented by the following Chemical Formula 3, and wherein the olefin-based polymer film has a heat seal strength of 30 gf / 2.5 cm or greater, preferably 30 to 150 gf / 2.5 cm, measured at 0.2 bar, 1.5 seconds, and 130° C., a heat seal strength of 150 gf / 2.5 cm or greater, preferably 150 to 210 gf / 2.5 cm, and a hot tack strength of 100° C. or greater. The thermal adhesive strength is 0.45 N / 2 cm or more, preferably 0.45 to 2.5 N / 2 cm, and the hot tack strength at 110° C. is 3.45 N / 2 cm or more, preferably 3.45 to 3.57 N / 2 cm.

[0122] [Chemical Formula 1]

[0123] [Chemical Formula 2]

[0124] [Chemical Formula 3]

[0125] In the above chemical formula, M1, M2, X and R1 to R 10 Same as described above in the olefin polymer section.

[0126] In the above step (a), the transition metal compound, the olefinic monomer and the polymerization method thereof are the same as those described in the above sections on olefin polymers and on the production method of olefinic polymers.

[0127] In step (b), the method for forming the olefin polymer film according to the embodiment of the present invention is not particularly limited, and any molding method known in the art can be used. For example, the olefin polymer film can be produced by conventional methods such as blown film molding, extrusion molding, and casting molding. Among them, blown film molding is the most preferred method.

[0128] The properties of the olefin-based polymer film obtained by the method for producing an olefin-based polymer film according to a specific example of the present invention are the same as those described in the above section on the olefin-based polymer film.

[0129] Modes for Carrying Out the Invention

[0130] Example

[0131] The present invention will be described in more detail below with reference to the following examples. However, the following examples are only for illustrating the present invention, and the scope of the present invention is not limited thereto.

[0132] Manufacturing Example

[0133] The transition metal compound of Chemical Formula 1-1 (bis(n-propylcyclopentadienyl)hafnium dichloride) and the transition metal compound of Chemical Formula 2-1 (bis(n-butylcyclopentadienyl)zirconium dichloride) were purchased from TCI, and the transition metal compound of Chemical Formula 1-2 (dimethylbis(n-propylcyclopentadienyl)hafnium dichloride) and the transition metal compound of Chemical Formula 2-2 (bis(isobutylcyclopentadienyl)zirconium dichloride) were purchased from TCI. dichloride) and the transition metal compound of Chemical Formula 3-1 ((pentamethylcyclopentadienyl)(n-propylcyclopentadienyl)zirconium dichloride) were purchased from MCN and used without further purification.

[0134] Production Example 1

[0135] 892 g of a 10% methylaluminoxane toluene solution was added to 4.47 g of the transition metal compound of Chemical Formula 1-1 and 1.67 g of the transition metal compound of Chemical Formula 2-1, and the mixture was stirred at room temperature for 1 hour. The resulting solution was added to 200 g of silica (XPO-2402), and 1.5 liters of toluene was further added, followed by stirring at 70°C for 2 hours. The supported catalyst was washed with 500 ml of toluene and dried under vacuum at 60°C overnight to obtain 280 g of a powdered supported catalyst.

[0136] Production Example 2

[0137] 277 g of a supported catalyst was obtained by the same method as in Production Example 1 except that 4.47 g of the transition metal compound of Chemical Formula 1-1 and 1.67 g of the transition metal compound of Chemical Formula 2-2 were used.

[0138] Production Example 3

[0139] 280 g of a supported catalyst was obtained by the same method as in Production Example 1 except that 4.47 g of the transition metal compound of Chemical Formula 1-1 and 1.68 g of the transition metal compound of Chemical Formula 3-1 were used.

[0140] Production Example 4

[0141] 282 g of a supported catalyst was obtained by the same method as in Production Example 1 except that 4.07 g of the transition metal compound of Chemical Formula 1-2 and 1.67 g of the transition metal compound of Chemical Formula 2-2 were used.

[0142] Production Example 5

[0143] 279 g of a supported catalyst was obtained by the same method as in Production Example 1 except that 4.07 g of the transition metal compound of Chemical Formula 1-2 and 1.68 g of the transition metal compound of Chemical Formula 3-1 were used.

[0144] Examples 1 to 5

[0145] Ethylene / 1-hexene copolymers were produced using a gas phase fluidized bed reactor in the presence of the supported catalysts obtained in Production Examples 1 to 5. The ethylene partial pressure in the reactor was maintained at approximately 15 kg / cm 2 , and maintain the polymerization temperature at 80-90°C.

[0146] The polymerization conditions of the above examples are shown in Table 1 below.

[0147] [Table 1]

[0148] Example 1 Example 2 Example 3 Example 4 Example 5 catalyst Production Example 1 Production Example 2 Production Example 3 Production Example 4 Production Example 5 Polymerization temperature (℃) 85.1 84.6 84.3 84.8 85.2 Superficial gas velocity (m / s) 53.2 53.1 53.4 53.2 53.2 Production capacity (kg / h) 10.1 9.9 10.0 9.7 10.3 <![CDATA[Ethylene pressure (kg / cm 2 )]]> 14.18 14.12 14.13 14.21 14.13 Hydrogen / ethylene molar ratio 0.03 0.03 0.05 0.03 0.05 1-Hexene / ethylene molar ratio 1.32 1.23 1.37 1.17 1.47 Catalyst activity (gPE / gCat) 3,489 3,171 3,780 5,185 4,802 Bulk density (g / cc) 0.413 0.426 0.434 0.415 0.433

[0149] Comparative Examples 1-2

[0150] For comparison, Hanwha Solutions' linear low-density polyethylene M1810HN (density 0.9180 g / cm 3 , melt index 1.0g / 10min; Comparative Example 1) and M2010HN (density 0.9200g / cm 3 , melt index 1.0 g / 10 min; Comparative Example 2).

[0151] Test example

[0152] The physical properties of the olefin polymers of the above examples were measured according to the following methods and standards. The results are shown in Table 2 below.

[0153] (1) Density

[0154] The measurement was performed according to ASTM D1505.

[0155] (2) Melt index and melt flow ratio (MFR)

[0156] According to ASTM D 1238, the melt index was measured at 190°C with a load of 21.6 kg and with a load of 2.16 kg, and the ratio (MI 21.6 / MI 2.16 ).

[0157] (3) Comonomer distribution slope (CDS)

[0158] The measurement was performed at 170°C using gel permeation chromatography-Fourier transform infrared absorption spectroscopy (GPC-FTIR).

[0159] (4) Melting temperature

[0160] The melting point of the polymer was measured using a differential scanning calorimeter (DSC, DSC 2920, manufactured by TA Instruments). Specifically, the polymer was heated to 200°C, maintained at that temperature for 5 minutes, cooled to 20°C, and then heated again at a rate of 20°C / min.

[0161] [Table 2]

[0162] The resins of Examples 1-5 and Comparative Examples 1-2 were used to produce 50 μm thick films through a 40 mm blown film extruder (40 mm Φ screw, 75 mm Φ die, 2 mm die gap). Extrusion conditions were fixed at C1 / C2 / C3 / A / D1 / D2 = 160 / 165 / 170 / 175 / 180 / 180°C, a rotation speed of 60 rpm, and a blow-up ratio (BUR) of 2.

[0163] The physical properties of the olefin polymer films of the above Examples and Comparative Examples were measured according to the following methods and standards. The results are shown in Table 3 below.

[0164] (5) Haze

[0165] A film was formed into a thickness of 50 μm and measured according to ASTM D 1003. Each test piece was measured five times, and the average value was calculated.

[0166] (6) Transparency

[0167] A film was formed into a thickness of 50 μm and measured according to ASTM D 01003. Each test piece was measured five times, and the average value was calculated.

[0168] (7) Heat seal strength

[0169] The measurement was performed according to ASTM F88.

[0170] (8) Hot tack strength

[0171] The measurement was performed according to ASTM F1921.

[0172] [Table 3]

[0173] Industrial Application Possibilities

[0174] The olefin polymer according to the embodiment of the present invention has excellent processability, and the olefin polymer film produced therefrom, specifically, the linear low-density polyethylene film, has excellent mechanical strength and heat-sealing properties, especially low-temperature heat-sealing properties.

Claims

1. An olefin polymer having a density (1) of 0.910 to 0.940 g / cm 3 (2) Melt index (I) measured at 190°C with a load of 2.16 kg 2.16 ) is 0.5 to 2.0 g / 10 minutes; (3) the melt index (I 21.6 ) and the melt index (I 2.16 ) ratio, i.e., MFR, is 20 to 60; (4) the comonomer distribution slope, i.e., CDS, defined by the following mathematical formula 1 is 3 or more, in, The olefin polymer is produced by polymerizing an olefin monomer in the presence of a composite catalyst, the composite catalyst comprising: at least one first transition metal compound, which is at least one of the transition metal compounds represented by the following chemical formulas 1-1 and 1-2; and at least one second transition metal compound, which is at least one of the transition metal compounds represented by the following chemical formulas 2-1, 2-2, and 3-1: In the chemical formula, Me is a methyl group, [Mathematical formula 1] Among them, C 20 and C 80 is the comonomer content at the points where the cumulative mass fractions are 20% and 80% in the comonomer distribution, M 20 and M 80 are the molecular weights at the points where the cumulative mass fractions of the comonomer distribution are 20% and 80%, respectively.

2. The olefin-based polymer according to claim 1, wherein (1) The density of olefin polymers is 0.910 to 0.925 g / cm 3 ; (2) The melt index measured at 190°C with a load of 2.16 kg is 0.8 to 1.5 g / 10 minutes; (3) MFR is 20 to 50; (4) CDS is 3 to 15.

3. The olefin-based polymer according to claim 1, wherein The molar ratio of the first transition metal compound to the second transition metal compound is in the range of 100:1 to 1:

100.

4. The olefin-based polymer according to claim 1, wherein The catalyst comprises at least one co-catalyst compound selected from the group consisting of a compound represented by the following Chemical Formula 4, a compound represented by Chemical Formula 5, and a compound represented by Chemical Formula 6. [Chemical Formula 4] [Chemical Formula 5] [Chemical Formula 6] [L-H] + [Z(A)4] - or [L] + [Z(A)4] - In the chemical formula 4, n is an integer greater than or equal to 2, and R a Halogen atoms, C 1-20 Hydrocarbon, or halogen-substituted C 1-20 Hydrocarbon group, In the chemical formula 5, D is aluminum (A1) or boron (B), R b 、R c and R d are each independently a halogen atom, C 1-20 Hydrocarbon, halogen-substituted C 1-20 Hydrocarbon, or C 1-20 Alkoxy, In the chemical formula 6, L is a neutral or cationic Lewis base, [LH] + and [L] + is a Bronsted acid, Z is a Group 13 element, and A is independently a substituted or unsubstituted C 6-20 Aryl, or substituted or unsubstituted C 1-20 alkyl.

5. The olefin-based polymer according to claim 4, wherein The catalyst further comprises a support that supports the transition metal compound, the co-catalyst compound, or both. The olefin polymer according to claim 5, wherein The support comprises at least one selected from the group consisting of silicon oxide, aluminum oxide, and magnesium oxide.

7. The olefin-based polymer according to claim 5, wherein Based on 1 gram of the carrier, the total amount of the composite transition metal compound supported by the carrier is 0.001 to 1 mmole, and based on 1 gram of the carrier, the total amount of the co-catalyst compound supported by the carrier is 2 to 15 mmole.

8. The olefin-based polymer according to claim 1, wherein The olefin-based polymer is a copolymer of an olefin-based monomer and an olefin-based comonomer.

9. The olefin-based polymer according to claim 8, wherein The olefin monomer is ethylene, and the olefin comonomer is one or more selected from propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, and 1-hexadecene.

10. The olefin-based polymer according to claim 9, wherein The olefin polymer is linear low-density polyethylene, the olefin monomer is ethylene, and the olefin comonomer is 1-hexene.

11. A method for producing an olefin-based polymer, comprising the step of polymerizing an olefin-based monomer in the presence of a composite catalyst to obtain an olefin-based polymer, wherein the composite catalyst comprises: at least one first transition metal compound which is at least one of the transition metal compounds represented by the following chemical formulas 1-1 and 1-2; and at least one second transition metal compound which is at least one of the transition metal compounds represented by the following chemical formulas 2-1, 2-2, and 3-1, and wherein the density (1) of the olefin-based polymer is 0.910 to 0.940 g / cm 3 (2) Melt index (I) measured at 190°C with a load of 2.16 kg 2.16 ) is 0.5 to 2.0 g / 10 minutes; (3) the melt index (I 21.6 ) and the melt index (I 2.16 ) is 20 to 60; (4) the comonomer distribution slope, i.e., CDS, defined by the following mathematical formula 1 is 3 or more: In the chemical formula, Me is a methyl group, [Mathematical formula 1] C of the mathematical formula 1 20 、C 80 、M 20 and M 80 Same as defined in claim 1.

12. The method for producing an olefin-based polymer according to claim 11, wherein The polymerization of the olefin-based monomers is carried out by gas phase polymerization.

13. An olefin polymer film is made from the olefin polymer according to claim 1, wherein the heat sealing strength measured under the conditions of 0.2 bar, 1.5 seconds and 130°C is greater than 30 gf / 2.5 cm, the heat sealing strength measured under the conditions of 0.2 bar, 1.5 seconds and 135°C is greater than 150 gf / 2.5 cm, the hot tack strength at 100°C is greater than 0.45 N / 2 cm, and the hot tack strength at 110°C is greater than 3.45 N / 2 cm.

14. The olefin polymer film according to claim 13, wherein The heat seal strength measured under the conditions of 0.2 bar, 1.5 seconds and 130°C is 30-150 gf / 2.5 cm, and the heat seal strength measured under the conditions of 0.2 bar, 1.5 seconds and 135°C is 150-210 gf / 2.5 cm. The hot tack strength at 100°C is 0.45-2.5 N / 2 cm, and the hot tack strength at 110°C is 3.45-3.57 N / 2 cm. The olefin polymer film according to claim 14 , wherein The olefin-based polymer film is at least one selected from a stretch film, a cover film, a laminate film, a silage film, and an agricultural film.

16. A method for producing an olefin-based polymer film, comprising the steps of: (a) polymerizing an olefin-based monomer in the presence of a composite catalyst to obtain an olefin-based polymer; and (b) molding the olefin-based polymer to obtain a film, wherein the composite catalyst comprises: at least one first transition metal compound selected from the compounds represented by the following chemical formulas 1-1 and 1-2; and at least one second transition metal compound selected from the compounds represented by the following chemical formulas 2-1, 2-2, and 3-1, wherein the olefin-based polymer film has a heat seal strength of 30 gf / 2.5 cm or greater measured at 0.2 bar, 1.5 seconds, and 130° C., a heat seal strength of 150 gf / 2.5 cm or greater measured at 0.2 bar, 1.5 seconds, and 135° C., a hot tack strength of 0.45 N / 2 cm or greater at 100° C., and a hot tack strength of 3.45 N / 2 cm or greater at 110° C. In the chemical formula, Me is a methyl group.

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