Olefin-based polymer, film made therefrom, and method for producing the same

Abstract

The present invention relates to an olefin-based polymer, a film made therefrom, and a method for producing the same. The olefin-based polymer according to a specific example of the present invention has excellent processability, and the film made therefrom, particularly a linear low-density polyethylene film, has excellent mechanical strength, particularly impact strength.

Description

Technical Field

[0001] The present invention relates to olefin polymers, films made therefrom, and methods for producing them. Specifically, the present invention relates to olefin polymers having excellent processability, olefin polymer films made therefrom and having excellent mechanical strength, particularly falling impact strength, and methods for producing them. Background Art

[0002] As one of the catalysts for olefin polymerization, a metallocene catalyst is a compound formed by coordinating ligands such as cyclopentadienyl, indenyl, cycloheptadienyl, etc. to a transition metal or transition metal halide, and has a sandwich structure as its basic form.

[0003] As another catalyst for olefin polymerization, in the Ziegler-Natta catalyst, the active sites, i.e., the metal components, are dispersed on the surface of an inert solid, and the properties of the active sites are non-uniform. In contrast, a metallocene catalyst is a compound having a fixed structure, and thus is known as a single-site catalyst in which all active sites have the same polymerization characteristics. The polymer obtained by polymerizing with such a metallocene catalyst has a narrow molecular weight distribution, a uniform comonomer distribution, and a higher copolymerization activity than the Ziegler-Natta catalyst.

[0004] On the other hand, linear low-density polyethylene (LLDPE) is produced by copolymerizing ethylene and alpha-olefins at low pressure using a polymerization catalyst. It has a narrow molecular weight distribution, short chain branches (SCB) of a fixed length, and generally does not have long chain branches (LCB). Films made of linear low-density polyethylene not only have the characteristics of conventional polyethylene, but also have high tensile strength and elongation at break, and are excellent in tear strength, impact strength, etc., and are thus widely used in stretch films, covering films, etc. where it is difficult to apply existing low-density polyethylene or high-density polyethylene.

[0005] However, linear low-density polyethylene produced by a metallocene catalyst has a tendency to have reduced processability due to its narrow molecular weight distribution.

[0006] Therefore, there is a need for olefin polymers that have excellent processability and can produce films having excellent mechanical strength, particularly falling impact strength. 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, particularly drop impact strength.

[0008] Another object of the present invention is to provide an olefin-based polymer film made of the above olefin-based polymer and having excellent mechanical strength, particularly drop impact strength.

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

[0010] According to a specific example of the present invention, there is provided an olefin-based polymer having a (1) density of 0.9 to 0.95 g / cm 3 ; (2) melt index (I 2.16 ) measured at 190 °C under a load of 2.16 kg is 0.1 to 5.0 g / 10 min; (3) melt index (I 21.6 ) measured at 190 °C under a load of 21.6 kg and the melt index (I 2.16 ) measured under a load of 2.16 kg have a ratio (melt flow ratio; MFR) of 20 or more; (4) shear thinning index defined by the following mathematical formula 1 is 8 to 15; (5) extrusion load (torque) when the extrusion amount is 5.8 to 5.9 kg / hr is 270 Nm or less, and the film produced therefrom has a drop impact strength (Type B) of 700 g or more, preferably 700 to 2000 g, based on a thickness of 50 μm.

[0011] [Mathematical formula 1]

[0012] Shear thinning index = η0 / η 500

[0013] wherein η0 and η 500 are complex viscosities at frequencies of 0.1 rad / s and 500 rad / s, respectively.

[0014] In a specific example of the present invention, the (1) density of the olefin-based polymer may be 0.915 to 0.945 g / cm 3 ; (2) melt index (I 2.16 ) measured at 190 °C under a load of 2.16 kg is 0.1 to 5.0 g / 10 min; (3) melt index (I 21.6 ) measured at 190 °C under a load of 21.6 kg and the melt index (I 2.16The melt flow ratio (MFR) is 20 or more; (4) The shear thinning index defined by Mathematical Formula 1 is 9 to 15; (5) When the extrusion amount is 5.8 to 5.9 kg / hr, the extrusion load (torque) is 260 Nm or less, and the film produced therefrom can have a falling impact strength (Type B) of 700 g or more based on a thickness of 50 μm.

[0015] In a preferred specific example of the present invention, the olefin-based polymer may be (1) The density of the olefin-based polymer is 0.915 to 0.942 g / cm 3 ; (2) The melt index measured at 190 °C under a load of 2.16 kg is 0.5 to 3.5 g / 10 minutes; (3) The MFR is 20 to 50; (4) The shear thinning index defined by Mathematical Formula 1 is 9 to 12; (5) When the extrusion amount is 5.8 to 5.9 kg / hr, the extrusion load is 200 to 255 Nm.

[0016] In a specific example of the present invention, the above olefin-based polymer can be produced by polymerizing an olefin-based monomer in the presence of a composite catalyst, and the composite catalyst includes 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 compounds represented by the following Chemical Formula 2 and the compounds represented by the following Chemical Formula 3.

[0017] [Chemical Formula 1]

[0018]

[0019] [Chemical Formula 2]

[0020]

[0021] [Chemical Formula 3]

[0022]

[0023] In the above Chemical Formula 1 to Chemical Formula 3, M1 and M2 are different from each other and are each independently titanium (Ti), zirconium (Zr), or hafnium (Hf),

[0024] X is each independently a 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, or C 1-20 alkyl amido,

[0025] R1 to R 10 are each independently hydrogen, a substituted or unsubstituted C 1-20 alkyl group, a substituted or unsubstituted C 2-20 alkenyl group, a substituted or unsubstituted C 6-20 aryl group, a substituted or unsubstituted C 1-20 alkyl C 6-20 aryl group, a substituted or unsubstituted C 6-20 aryl C 1-20 alkyl group, a substituted or unsubstituted C 1-20 heteroalkyl group, a substituted or unsubstituted C 3-20 heteroaryl group, a substituted or unsubstituted C 1-20 alkylamido group, a substituted or unsubstituted C 6-20 aryl amido group, a substituted or unsubstituted C 1-20 alkylene group, or a substituted or unsubstituted C 1-20 silyl group, and R1 to R 10 are each independently connected to adjacent groups and can form a substituted or unsubstituted saturated or unsaturated C 4-20 ring.

[0026] In a specific example 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 group, and R1 to R 10 can each be hydrogen, a substituted or unsubstituted C 1-20 alkyl group, a substituted or unsubstituted C 1-20 alkenyl group, or a substituted or unsubstituted C 6-20 aryl group.

[0027] In a preferred specific example of the present invention, M1 can be hafnium, M2 can be zirconium, and X can be chlorine or methyl.

[0028] In a preferred specific example of the present invention, the first transition metal compound can 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 can be at least one of the transition metal compounds represented by the following Chemical Formulas 2-1, 2-2, and 3-1.

[0029] [Chemical Formula 1-1][Chemical Formula 1-2]

[0030]

[0031] [Chemical Formula 2-1][Chemical Formula 2-2][Chemical Formula 3-1]

[0032]

[0033] In the above chemical formulas, Me is a methyl group.

[0034] 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.

[0035] In a specific example of the present invention, the above catalyst may contain at least one cocatalyst selected from the compounds represented by the following Chemical Formula 4, the compounds represented by Chemical Formula 5, and the compounds represented by Chemical Formula 6.

[0036] [Chemical Formula 4]

[0037]

[0038] [Chemical Formula 5]

[0039]

[0040] [Chemical Formula 6]

[0041] [L-H] + [Z(A)4] - or [L] + [Z(A)4] -

[0042] In the above Chemical Formula 4, n is an integer of 2 or more, and R a is a halogen atom, a C 1-20 hydrocarbon group, or a C 1-20 hydrocarbon group substituted with a halogen.

[0043] In the above Chemical Formula 5, D is aluminum (Al) or boron (B), and R b , R c and R d are each independently a halogen atom, a C 1-20 hydrocarbon group, a C 1-20 hydrocarbon group substituted with a halogen, or a C 1-20 alkoxy group.

[0044] In the above Chemical Formula 6, L is a neutral or cationic Lewis base, [L-H] + and [L] + are Bronsted acids, Z is a Group 13 element, and A is each independently a substituted or unsubstituted C 6-20 aryl group, or a substituted or unsubstituted C 1-20 alkyl group.

[0045] In a specific example of the present invention, the above catalyst may further contain a supported transition metal compound, a cocatalyst compound, or a carrier for both of them.

[0046] In a preferred specific example of the present invention, the above carrier may contain at least one selected from silica, alumina, and magnesia.

[0047] Among them, based on 1 g of the carrier, the total amount of the composite transition metal compound supported on the carrier is 0.001 to 1 mmole, and based on 1 g of the carrier, the total amount of the cocatalyst compound supported on the carrier is 2 to 15 mmole.

[0048] In a specific example of the present invention, the olefin-based polymer is a copolymer of an olefin-based monomer and an olefin-based comonomer. Specifically, the olefin-based monomer is ethylene, and the olefin-based comonomer may 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-based polymer is linear low density polyethylene in which the olefin-based monomer is ethylene and the olefin-based comonomer is 1-hexene.

[0049] According to a specific example of the present invention, there is provided a method for producing an olefin-based polymer, including a step of polymerizing an olefin-based monomer in the presence of a composite catalyst to obtain an olefin-based polymer, wherein the composite catalyst includes 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 compounds represented by the above Chemical Formula 2 and the compounds represented by the above Chemical Formula 3, and the olefin-based polymer has (1) a density of 0.9 to 0.95 g / cm 3 , preferably 0.91 to 0.945 g / cm 3 ; (2) a melt index (I 2.16 ) measured at 190 °C under a load of 2.16 kg is 0.1 to 5.0 g / 10 minutes, preferably 0.3 to 4.0 g / 10 minutes; (3) the ratio (melt flow ratio; MFR) of the melt index (I 21.6 ) measured at 190 °C under a load of 21.6 kg to the melt index (I 2.16 ) measured under a load of 2.16 kg is 20 or more, preferably 22; (4) the shear thinning index defined by the following Mathematical Formula 1 is 8 to 15, preferably 9 to 15; (5) the extrusion load (torque) when the extrusion amount is 5.8 to 5.9 kg / hr is 270 Nm or less, preferably 260 Nm or less, and the film produced therefrom has a falling impact strength (Type B) of 700 g or more, preferably 700 to 2000 g, based on a thickness of 50 μm.

[0050] In a specific example of the present invention, the polymerization of the olefin-based monomer can be carried out by gas phase polymerization. Specifically, the polymerization of the olefin-based monomer can be carried out in a gas phase fluidized bed reactor.

[0051] The processability of the olefin polymer according to a specific example of the present invention is excellent, and the mechanical strength, particularly the drop impact strength, of the film made therefrom, particularly the linear low density polyethylene film, is excellent. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 It is a graph showing the complex viscosity according to the frequency of the olefin polymer in Example 1 and 2 and Comparative Example 1.

[0053] Figure 2 It is a graph showing the extrusion load (torque) according to the extrusion amount of the olefin polymer in Example 1 and 2 and Comparative Example 1. DETAILED DESCRIPTION

[0054] Hereinafter, the present invention will be described in more detail.

[0055] Olefin polymer

[0056] According to a specific example of the present invention, there is provided an olefin polymer having a (1) density of 0.9 to 0.95 g / cm 3 ; (2) a melt index (I 2.16 ) measured at 190 ° C under a load of 2.16 kg of 0.1 to 5.0 g / 10 minutes; (3) a melt index (I 21.6 ) measured at 190 ° C under a load of 21.6 kg and a melt index (I 2.16 ) measured under a load of 2.16 kg has a ratio (melt flow ratio; MFR) of 20 or more; (4) a shear thinning index defined by the following Mathematical Formula 1 of 8 to 15; (5) an extrusion load (torque) when the extrusion amount is 5.8 to 5.9 kg / hr is 270 Nm or less, and the film made therefrom has a drop impact strength (Type B) of 700 g or more, preferably 700 to 2000 g, based on a thickness of 50 μm.

[0057] In the specific example of the present invention, the (1) density of the olefin polymer is 0.915 to 0.945 g / cm 3 ; (2) a melt index (I 2.16 ) measured at 190 ° C under a load of 2.16 kg of 0.1 to 5.0 g / 10 minutes; (3) a melt index (I 21.6 ) measured at 190 ° C under a load of 21.6 kg and a melt index (I 2.16) has a melt flow ratio (MFR) of 20 or more; (4) the shear thinning index defined by Mathematical Formula 1 is 9 to 15; (5) the extrusion load (torque) when the extrusion amount is 5.8 to 5.9 kg / hr is 260 Nm or less, and the film produced therefrom can have a falling impact strength (Type B) of 700 g or more based on a thickness of 50 μm.

[0058] In a preferred specific example of the present invention, the olefin-based polymer may be (1) the density of the olefin-based polymer is 0.915 to 0.942 g / cm 3 ; (2) the melt index measured at 190 °C under a load of 2.16 kg is 0.5 to 3.5 g / 10 minutes; (3) the MFR is 20 to 50; (4) the shear thinning index defined by Mathematical Formula 1 is 9 to 12; (5) the extrusion load when the extrusion amount is 5.8 to 5.9 kg / hr is 200 to 255 Nm.

[0059] In a specific example of the present invention, the density of the olefin-based polymer is 0.9 to 0.95 g / cm 3 . Preferably, the density of the olefin-based polymer can be 0.91 to 0.945 g / cm 3 , 0.915 to 0.945 g / cm 3 , 0.91 to 0.93 g / cm 3 , 0.915 to 0.942 g / cm 3 or 0.915 to 0.925 g / cm 3 .

[0060] In a specific example of the present invention, the melt index (I 2.16 ) of the olefin-based polymer measured at 190 °C under a load of 2.16 kg is 0.1 to 5.0 g / 10 minutes. Preferably, the melt index of the olefin-based polymer measured at 190 °C under a load of 2.16 kg can be 0.3 to 4.0 g / 10 minutes, 0.5 to 3.5 g / 10 minutes or 0.5 to 3.0 g / 10 minutes.

[0061] In a specific example of the present invention, the ratio (melt flow ratio; MFR) of the melt index (I 21.6 ) of the olefin-based polymer measured at 190 °C under a load of 21.6 kg to the melt index (I 2.16 ) measured under a load of 2.16 kg is 20 or more. Preferably, the MFR of the olefin-based polymer can be 22 or more or 20 to 50.

[0062] In a specific example of the present invention, the shear thinning index of the olefin-based polymer defined by the following Mathematical Formula 1 is 8 to 15. Preferably, the shear thinning index of the olefin-based polymer can be 9 to 15 or 9 to 12.

[0063] [Mathematical Formula 1]

[0064] Shear thinning index = η0 / η 500

[0065] where η0 and η 500 are the complex viscosities at frequencies of 0.1 rad / s and 500 rad / s, respectively.

[0066] A polymer has a property intermediate between that of a perfectly elastic substance and a viscous liquid in the molten state, which is called viscoelasticity. That is, when a polymer is subjected to a shear stress in the molten state, the deformation is not proportional to the shear stress, and in addition, it has the property that the viscosity changes according to the shear stress. Such a property is understood to be due to the large molecular size and complex intermolecular structure of the polymer.

[0067] In particular, when a molded article is manufactured using a polymer, the shear thinning phenomenon is taken into serious consideration. The shear thinning phenomenon refers to the phenomenon that the viscosity of the polymer decreases as the shear rate increases, and such shear thinning characteristics have a great influence on the molding method of the polymer.

[0068] The larger the shear thinning index, the higher the complex viscosity at low frequencies and the lower the complex viscosity at high frequencies. Therefore, the physical properties and processability of the polymer can be excellent.

[0069] In a specific example of the present invention, the extrusion load (torque) when the extrusion amount of the olefin-based polymer is 5.8 to 5.9 kg / hr is 270 Nm or less. Preferably, the extrusion load (torque) of the olefin-based polymer with an extrusion amount of 5.8 to 5.9 kg / hr is 260 Nm or less or 200 to 255 Nm.

[0070] In a specific example of the present invention, the film made of the olefin-based polymer has a falling impact strength of 700 g or more based on a thickness of 50 μm. Preferably, the film made of the olefin-based polymer can have a falling impact strength of 700 to 2000 g based on a thickness of 50 μm.

[0071] The olefin-based polymer according to the specific example of the present invention has a relatively wide molecular weight distribution, and relatively more short side chains exist in the high molecular weight component. Therefore, it can be understood that the mechanical strength, especially the falling impact strength, of the olefin-based polymer film manufactured therefrom is excellent.

[0072] In a specific example of the present invention, the olefin-based polymer film can be effectively used as a stretch film, a covering film, a laminated film, a silage film, an agricultural film, etc.

[0073] In a specific example of the present invention, the method for forming an olefin-based polymer film according to the specific example of the present invention is not particularly limited, and a forming method known in the technical field to which the present invention pertains can be used. For example, the above-mentioned olefin-based polymer can be processed by conventional methods such as blown film forming, extrusion forming, and casting forming to manufacture an olefin-based polymer film. Among them, blown film forming is most preferred.

[0074] In a specific example of the present invention, the olefin-based polymer can be produced by polymerizing an olefin-based monomer in the presence of a composite catalyst, and the composite catalyst includes 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 compounds represented by the following Chemical Formula 2 and the compounds represented by the following Chemical Formula 3.

[0075] [Chemical Formula 1]

[0076]

[0077] [Chemical Formula 2]

[0078]

[0079] [Chemical Formula 3]

[0080]

[0081] In the above Chemical Formula 1 to Chemical Formula 3, M1 and M2 are different from each other and are each independently titanium (Ti), zirconium (Zr), or hafnium (Hf). Specifically, M1 and M2 can be different from each other and can each be zirconium or hafnium. Preferably, M1 can be hafnium and M2 can be zirconium.

[0082] X is each independently a 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 alkylamido, or C 6-20 arylamido. Specifically, each X can be a halogen or C 1-20 alkyl. Preferably, X can be chlorine or methyl.

[0083] R1 to R 10Each independently is hydrogen, a substituted or unsubstituted C 1-20 alkyl group, a substituted or unsubstituted C 2-20 alkenyl group, a substituted or unsubstituted C 6-20 aryl group, a substituted or unsubstituted C 1-20 alkyl C 6-20 aryl group, a substituted or unsubstituted C 6-20 aryl C 1-20 alkyl group, a substituted or unsubstituted C 1-20 heteroalkyl group, a substituted or unsubstituted C 3-20 heteroaryl group, a substituted or unsubstituted C 1-20 alkylamido group, a substituted or unsubstituted C 6-20 aryl amido group, a substituted or unsubstituted C 1-20 alkylene group, or a substituted or unsubstituted C 1-20 silyl group, wherein, R1 to R 10 each independently connect adjacent groups and can form a substituted or unsubstituted saturated or unsaturated C 4-20 ring. Specifically, R1 to R 10 each can be hydrogen, a substituted or unsubstituted C 1-20 alkyl group, a substituted or unsubstituted C 1-20 alkenyl group, or a substituted or unsubstituted C 6-20 aryl group.

[0084] In a specific example of the present invention, M1 and M2 are different from each other, and each is zirconium or hafnium, X is each halogen or C 1-20 alkyl group, R1 to R 10 each can be hydrogen, a substituted or unsubstituted C 1-20 alkyl group, a substituted or unsubstituted C 1-20 alkenyl group, or a substituted or unsubstituted C 6-20 aryl group.

[0085] In a preferred specific example of the present invention, M1 can be hafnium, M2 can be zirconium, and X can be chlorine or methyl.

[0086] In a preferred specific example of the present invention, the first transition metal compound can 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 can be at least one of the transition metal compounds represented by the following Chemical Formulas 2-1, 2-2 and 3-1.

[0087] [Chemical Formula 1-1][Chemical Formula 1-2]

[0088]

[0089] [Chemical Formula 2-1][Chemical Formula 2-2][Chemical Formula 3-1]

[0090]

[0091] In the above chemical formula, Me is methyl.

[0092] In a specific example of the present invention, the molar ratio of the first transition metal compound to the second transition metal compound ranges from 100:1 to 1:100. Preferably, the molar ratio of the first transition metal compound to the second transition metal compound ranges from 50:1 to 1:50. Preferably, the molar ratio of the first transition metal compound to the second transition metal compound ranges from 10:1 to 1:10.

[0093] In a specific example of the present invention, the above catalyst may include at least one cocatalyst compound selected from the compounds represented by the following Chemical Formula 4, the compound represented by Chemical Formula 5, and the compound represented by Chemical Formula 6.

[0094] [Chemical Formula 4]

[0095]

[0096] In the above Chemical Formula 4, n may be an integer of 2 or more, and R a may be a halogen atom, C 1-20 hydrocarbon, or C 1-20 hydrocarbon substituted by halogen. Specifically, R a may be methyl, ethyl, n-butyl, or isobutyl.

[0097] [Chemical Formula 5]

[0098]

[0099] In the above Chemical Formula 5, D is aluminum (Al) or boron (B), and R b , R c and R d are each independently a halogen atom, C 1-20 hydrocarbyl group, C 1-20 hydrocarbyl group substituted by halogen, or C 1-20 alkoxy group. Specifically, when D is aluminum (Al), R b , R c and R d may each independently be methyl or isobutyl, and when D is boron (B), R b , R c and R d may each be pentafluorophenyl.

[0100] [Chemical Formula 6]

[0101] [L-H] + [Z(A)4] - or [L]+ [Z(A)4] -

[0102] In the above chemical formula 6, L is a neutral or cationic Lewis base, [L-H] + and [L] + are Bronsted acids, Z is a Group 13 element, and A is independently a substituted or unsubstituted C 6-20 aryl, or a substituted or unsubstituted C 1-20 alkyl. Specifically, [L-H] + can be a dimethylanilinium cation, [Z(A)4] - can be [B(C6F5)4] - [L] + can be [(C6H5)3C] + .

[0103] Specifically, examples of the compound represented by the above chemical formula 4 include methylaluminoxane, ethylaluminoxane, isobutylaluminoxane, butylaluminoxane, etc. Preferably, it is methylaluminoxane, but it is not limited thereto.

[0104] Examples of the compound represented by the above 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 methanolate, dimethylaluminum ethanolate, trimethylboron, triethylboron, triisobutylboron, tripropylboron, tributylboron, etc. Preferably, they are trimethylaluminum, triethylaluminum, and triisobutylaluminum, but it is not limited thereto.

[0105] Examples of the compound represented by the above chemical formula (6) include triethylammonium tetraphenylborate, tributylammonium tetraphenylborate, trimethylammonium tetraphenylborate, tripropylammonium tetraphenylborate, trimethylammonium tetrakis(p-tolyl)borate, trimethylammonium tetrakis(o,p-dimethylphenyl)borate, tributylammonium tetrakis(p-trifluoromethylphenyl)borate, trimethylammonium tetrakis(p-trifluoromethylphenyl)borate, tributylammonium tetrakis(pentafluorophenyl)borate, N,N-diethylbenzylammonium tetraphenylborate, N,N-diethylbenzylammonium tetrakis(pentafluorophenyl)borate, diethylammonium tetrakis(pentafluorophenyl)borate, triphenyltetraphenylborate, trimethyltetraphenylborate, triethylammonium tetraphenylaluminate, tributylammonium tetraphenylaluminate, trimethylammonium tetraphenylaluminate, tripropylammonium tetraphenylaluminate, trimethylammonium tetrakis(p-tolyl)aluminate, tripropylammonium tetrakis(p-tolyl)aluminate, triethylammonium tetrakis(o,p-dimethylphenyl)aluminate, tributylammonium tetrakis(p-trifluoromethylphenyl)aluminate, trimethylammonium tetrakis(p-trifluoromethylphenyl)aluminate, tributylammonium tetrakis(pentafluorophenyl)aluminate, N,N-diethylbenzylammonium tetraphenylaluminate, N,N-diethylbenzylammonium tetrakis(pentafluorophenyl)aluminate, diethylammonium tetrakis(pentafluorophenyl)aluminate, triphenyltetraphenylaluminate, trimethyltetraphenylaluminate, tripropylammonium tetrakis(p-tolyl)borate, triethylammonium tetrakis(o,p-dimethylphenyl)borate, tributylammonium tetrakis(p-trifluoromethylphenyl)borate, triphenylcarbenium tetrakis(p-trifluoromethylphenyl)borate, triphenylcarbenium tetrakis(pentafluorophenyl)borate, and the like.

[0106] In a specific example of the present invention, the above catalyst may further contain a support for supporting a transition metal compound, a cocatalyst compound, or both of them. Specifically, the support may support all of the transition metal compound and the cocatalyst compound.

[0107] At this time, the support may contain a substance having a hydroxyl group on its surface. Preferably, a substance having a hydroxyl group and a siloxanyl group with high reactivity and having been dried to remove moisture on its surface may be used. For example, the support may contain at least one selected from silica, alumina, and magnesia. Specifically, silica, silica-alumina, and silica-magnesia dried at a high temperature may be used as the support, and they usually may contain oxide, carbonate, sulfate, and nitrate components such as Na2O, K2CO3, BaSO4, and Mg(NO3)2. In addition, they may also contain carbon, zeolite, magnesium chloride, and the like. However, the support is not limited thereto, and there is no particular limitation as long as it can support the transition metal compound and the cocatalyst compound.

[0108] The average particle size of the support may be 10 to 250 μm. Preferably, the average particle size may be 10 to 150 μm, and more preferably, it may be 20 to 100 μm.

[0109] The micropore volume of the support 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.

[0110] 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.

[0111] In a preferred specific example of the present invention, the carrier can be silica. At this time, the drying temperature of the silica can be 200 to 900 °C. The drying temperature is preferably 300 to 800 °C, more preferably 400 to 700 °C. When the drying temperature is less than 200 °C, there is too much moisture, and the moisture on the surface reacts with the promoter compound. When it is greater than 900 °C, the structure of the carrier may disintegrate.

[0112] The concentration of hydroxyl groups in the dried silica can be 0.1 to 5 mmole / g, preferably 0.7 to 4 mmole / g, more preferably 1.0 to 2 mmole / g. When the concentration of hydroxyl groups is less than 0.1 mmole / g, the loading amount of the first promoter compound becomes low. When it is greater than 5 mmole / g, there may be a problem of catalyst component deactivation.

[0113] Based on 1 g of the carrier, the total amount of the transition metal compound supported on the carrier can be 0.001 to 1 mmole. When the ratio of the transition metal compound to the carrier satisfies the above range, appropriate supported catalyst activity is exhibited, which is advantageous in maintaining catalyst activity and economy.

[0114] Based on 1 g of the carrier, the total amount of the promoter compound supported on the carrier can be 2 to 15 mmole. When the ratio of the promoter compound to the carrier satisfies the above range, it is advantageous in maintaining catalyst activity and economy.

[0115] One or more than two kinds of carriers can be used. For example, the transition metal compound and the promoter compound can be both supported on one kind of carrier, or the transition metal compound and the promoter compound can be respectively supported on two or more kinds of carriers. In addition, only one of the transition metal compound and the promoter compound can be supported on the carrier.

[0116] As a method for supporting the transition metal compound and / or the promoter compound that can be used in the olefin polymerization catalyst, a physical adsorption method or a chemical adsorption method can be used.

[0117] For example, the physical adsorption method may be as follows: a method of contacting a solution in which a transition metal compound is dissolved with a carrier and then drying; a method of contacting a solution in which a transition metal compound and a promoter compound are dissolved with a carrier and then drying; or a method of contacting a solution in which a transition metal compound is dissolved with a carrier and then drying to produce a carrier supporting the transition metal compound, and separately, contacting a solution in which a promoter compound is dissolved with a carrier and then drying to produce a carrier supporting the promoter compound, and then mixing them, etc.

[0118] The chemical adsorption method may be as follows: a method of first supporting a promoter compound on the surface of a carrier and then supporting a transition metal compound on the promoter compound; or a method of covalently bonding a functional group on the surface of the carrier (for example, when using silica, the hydroxyl group (-OH) on the silica surface) to a catalyst compound, etc.

[0119] In a specific example of the present invention, the olefin-based polymer may be a homopolymer of an olefin-based monomer or a copolymer of an olefin-based monomer and a comonomer. Preferably, the olefin-based polymer is a copolymer of an olefin-based monomer and an olefin-based comonomer.

[0120] Among them, the olefin-based monomer is selected from C 2-20 alpha-olefin, C 1-20 diolefin, C 3-20 cycloolefin, and C 3-20 cyclodiolefin, at least one of which.

[0121] For example, the olefin-based 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, etc. The olefin-based polymer may be a homopolymer containing only one of the above-exemplified olefin-based monomers, or may be a copolymer containing two or more of the above olefin-based monomers.

[0122] In an exemplary embodiment, the olefin-based polymer may be a copolymer copolymerized from ethylene and C 3-20 alpha-olefin. Preferably, the olefin-based polymer may be linear low-density polyethylene in which the olefin-based monomer is ethylene and the olefin-based comonomer is 1-hexene.

[0123] At this time, the content of ethylene is preferably 55 to 99.9% by weight, more preferably 90 to 99.9% by weight. The content of the alpha-olefin-based comonomer is preferably 0.1 to 45% by weight, more preferably 0.1 to 10% by weight.

[0124] Process for producing an olefin polymer

[0125] According to a specific example of the present invention, there is provided a process for producing an olefin polymer, which includes a step of polymerizing an olefin monomer in the presence of a composite catalyst to obtain an olefin polymer, wherein the composite catalyst includes 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 compounds represented by the following Chemical Formula 2 and the compounds represented by the following Chemical Formula 3.

[0126] [Chemical Formula 1]

[0127]

[0128] [Chemical Formula 2]

[0129]

[0130] [Chemical Formula 3]

[0131]

[0132] In the above chemical formulas, M1, M2, X, and R1 to R 10 are the same as those described in the above item of olefin polymer.

[0133] As described above, the olefin polymer produced by the production method according to a specific example of the present invention has (1) a density of 0.9 to 0.95 g / cm 3 ; (2) a melt index (I 2.16 ) measured at 190 °C under a load of 2.16 kg of 0.1 to 5.0 g / 10 min; (3) a ratio (melt flow ratio; MFR) of the melt index (I 21.6 ) measured at 190 °C under a load of 21.6 kg to the melt index (I 2.16 ) measured under a load of 2.16 kg of 20 or more; (4) a shear thinning index defined by the following Mathematical Formula 1 of 8 to 15; (5) an extrusion load (torque) of 270 Nm or less when the extrusion amount is 5.8 to 5.9 kg / hr, and the film produced therefrom has a falling impact strength (Type B) of 700 g or more based on a thickness of 50 μm.

[0134] [Mathematical Formula 1]

[0135] Shear thinning index = η0 / η 500

[0136] wherein η0 and η 500They are the complex viscosities at frequencies of 0.1 rad / s and 500 rad / s respectively.

[0137] In a specific example of the present invention, the (1) density of the olefin-based polymer is 0.915 to 0.945 g / cm 3 ; (2) the melt index (I 2.16 ) measured at 190 °C under a load of 2.16 kg is 0.1 to 5.0 g / 10 min; (3) the ratio (melt flow ratio; MFR) of the melt index (I 21.6 ) measured at 190 °C under a load of 21.6 kg to the melt index (I 2.16 ) measured under a load of 2.16 kg is 20 or more; (4) the shear thinning index defined by Mathematical Formula 1 is 9 to 15; (5) the extrusion load (torque) when the extrusion amount is 5.8 to 5.9 kg / hr is 260 Nm or less, and the film made therefrom can have a falling impact strength (Type B) of 700 g or more based on a thickness of 50 μm.

[0138] In a preferred specific example of the present invention, the olefin-based polymer may be (1) the density of the olefin-based polymer is 0.915 to 0.942 g / cm 3 ; (2) the melt index measured at 190 °C under a load of 2.16 kg is 0.5 to 3.5 g / 10 min; (3) the MFR is 20 to 50; (4) the shear thinning index defined by Mathematical Formula 1 is 9 to 12; (5) the extrusion load when the extrusion amount is 5.8 to 5.9 kg / hr is 200 to 255 Nm.

[0139] In a specific example of the present invention, the olefin-based polymer can be polymerized by, for example, polymerization reactions such as free radical, cationic, coordination, condensation, addition, etc., but is not limited thereto.

[0140] As an embodiment of the present invention, the olefin-based polymer can be produced by gas phase polymerization method, solution polymerization method or slurry polymerization method, etc. Preferably, the polymerization of the olefin-based monomer can be carried out by gas phase polymerization. Specifically, the polymerization of the olefin-based monomer can be carried out in a gas phase fluidized bed reactor.

[0141] When the olefin-based polymer is produced by solution polymerization method or slurry polymerization method, examples of the solvent that can be used include C such as pentane, hexane, heptane, nonane, decane and their isomers 5-12Aliphatic hydrocarbon solvents; aromatic hydrocarbon solvents such as toluene and benzene; hydrocarbon solvents substituted by chlorine atoms such as dichloromethane and chlorobenzene; and mixtures thereof, etc., but not limited thereto.

[0142] Mode of carrying out the invention

[0143] Examples

[0144] Hereinafter, the present invention will be described more specifically by way of examples. However, the following examples are only for illustrating the present invention, and the scope of the present invention is not limited thereto.

[0145] Production examples

[0146] 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 used without further purification process.

[0147] 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, 892 g of a toluene solution of 10% methylaluminoxane was added, and the mixture was stirred at room temperature for 1 hour. The solution after the reaction was added to 200 g of silica (XPO-2402), and 1.5 liters of toluene was further added, and the mixture was stirred at 70 °C for 2 hours. The supported catalyst after the loading was washed with 500 Ml of toluene and dried under vacuum at 60 °C overnight, thereby obtaining 280 g of a supported catalyst in powder form.

[0148] Examples 1 to 2

[0149] Using a gas-phase fluidized bed reactor, an ethylene / 1-hexene copolymer was produced in the presence of the supported catalyst obtained in Production Example 1. The ethylene partial pressure in the reactor was maintained at about 15 kg / cm 2 , and the polymerization temperature was maintained at 70 to 90 °C.

[0150] The polymerization conditions of the above examples are shown in Table 1 below.

[0151] [Table 1]

[0152] Example 1 Example 2 Polymerization temperature (°C) 75.4 80.9 Catalyst injection amount (g / h) 2.0 1.4 Hydrogen injection amount (g / h) 2.22 2.34 1-Hexene injection amount (kg / h) 1.60 1.63 Hydrogen / ethylene concentration (%) ratio 0.047 0.048 1-Hexene / ethylene concentration (%) ratio 2.096 1.993

[0153] Comparative Example 1

[0154] For comparison, linear low density polyethylene M1810HA (density 0.9200 g / cm 3 , melt index 1.0 g / 10 min) of Hanwha Total was used.

[0155] Test Example

[0156] The physical properties of the olefin polymers of the above examples were measured according to the methods and standards described below. The results are shown in Table 2 below.

[0157] (1) Density

[0158] It was measured according to ASTM D1505.

[0159] (2) Melt index and melt flow ratio (MFR)

[0160] According to ASTM D 1238, the melt index was measured at 190 °C with a load of 21.6 kg and a load of 2.16 kg, respectively, and the ratio (MI 21.6 / MI 2.16 ) was calculated.

[0161] (3) Rheological properties

[0162] The complex viscosity according to frequency was measured using Anton Parr's MCR702 at 190 °C in the frequency range of 0.1 - 500 rad / s and a strain condition of 5%.

[0163] (4) Extrusion load

[0164] The extrusion load according to the extrusion rate was measured using Collin's Gottfert at 190 °C under the conditions of screw rpm 20 - 80 and extrusion rate 1.4 - 5.8 kg / hr.

[0165] In addition, the resins of the examples and comparative examples were each made into a film with a thickness of 50 μm using a 40 mm blown film extruder (40 mm Φ screw, 75 mm Φ die, 2 mm die gap). At this time, the extrusion conditions were fixed as C1 / C2 / C3 / A / D1 / D2 = 160 / 165 / 170 / 175 / 180 / 180 °C, rotation speed 80 rpm, and blow-up ratio (BUR) 2.0. The physical properties of the manufactured films were measured according to the methods and standards described below. The measurement results are shown in Table 2 below.

[0166] (5) Drop impact strength

[0167] The film with a thickness of 50 μm was measured according to ASTM D1709 Type B.

[0168] [Table 2]

[0169]

[0170] The processability of the olefin polymer according to the specific example of the present invention is excellent, and the olefin polymer film produced therefrom, specifically, the linear low-density polyethylene film, has excellent mechanical strength, particularly excellent drop impact strength.

[0171] Industrial applicability

[0172] Therefore, the present invention can provide an olefin polymer with excellent processability and a film produced therefrom that has excellent mechanical strength, particularly excellent drop impact strength.

Claims

1. A method for manufacturing an olefin-based polymer, the method comprising a step of polymerizing an olefin-based monomer in the presence of a composite catalyst, the composite catalyst including at least one first transition metal compound represented by the following Chemical Formula 1-1 and 1-2, and at least one second transition metal compound selected from compounds represented by the following Chemical Formula 2-1, 2-2, and 3-1, wherein the olefin-based polymer has (1) a density of 0.9 to 0.95 g / cm 3 ; (2) a melt index measured at 190 °C under a load of 2.16 kg and represented by I 2.16 of 0.1 to 5.0 g / 10 min; (3) a melt index measured at 190 °C under a load of 21.6 kg is represented by I 21.6 , where the melt index ratio represented by MFR, which is the ratio of I 21.6 to I 2.16 , is 20 or more; (4) a shear thinning index defined by the following Mathematical Formula 1 of 8 to 15; (5) an extrusion load, i.e., torque, of 270 Nm or less when the extrusion amount is 5.8 to 5.9 kg / hr, and the film manufactured therefrom has a drop impact strength of 700 g or more measured according to ASTM D1709 Type B at a thickness of 50 μm: The polymerization of the olefin monomer is carried out at a polymerization temperature of 70.0 to 75.4 °C in the presence of the above-mentioned composite catalyst: In the said chemical formula, Me is methyl [Mathematical formula 1] Shear thinning index = η0 / η 500 Among them, η0 and η 500 are the complex viscosities at frequencies of 0.1 rad / s and 500 rad / s, respectively.

2. The method for producing an olefin polymer according to claim 1, wherein, The (1) density of the olefin polymer is 0.915 to 0.945 g / cm 3 ; (2) the melt index measured at 190 °C under a load of 2.16 kg and represented by I 2.16 is 0.1 to 5.0 g / 10 min; (3) the melt index measured at 190 °C under a load of 21.6 kg is represented by I 21.6 , where the melt index ratio represented by MFR, which is the ratio of I 21.6 to I 2.16 , is 20 or more; (4) the shear thinning index defined by Mathematical Formula 1 is 9 to 15; (5) the extrusion load, i.e., the torque, when the extrusion rate is 5.8 to 5.9 kg / hr is 260 Nm or less.

3. The method for producing an olefin 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 method for producing an olefin polymer according to claim 1, wherein, The catalyst contains at least one cocatalyst compound selected from the compounds represented by the following Chemical Formula 4, the compounds represented by Chemical Formula 5, and the compounds 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 Chemical Formula 4, n is an integer of 2 or more, and R a is a halogen atom, C 1-20 hydrocarbyl, or C 1-20 hydrocarbyl substituted by a halogen. In Chemical Formula 5, D is aluminum (Al) or boron (B), and R b , R c and R d are each independently a halogen atom, a C 1-20 hydrocarbyl group, a C 1-20 hydrocarbyl group substituted with a halogen, or a C 1-20 alkoxy group. In the chemical formula 6, L is a neutral or cationic Lewis base, [L-H] + and [L] + are Bronsted acids, Z is a Group 13 element, and each A is independently a substituted or unsubstituted C 6-20 aryl, or a substituted or unsubstituted C 1-20 alkyl.

5. The production method of the olefin polymer according to claim 4, wherein, The catalyst further contains a support carrying a transition metal compound, a cocatalyst compound, or both of them.

6. The method for producing an olefin polymer according to claim 5, wherein, The support contains at least one selected from silica, alumina, and magnesia.

7. The method for producing an olefin polymer according to claim 5, wherein, Based on 1 g of the support, the total amount of the composite transition metal compound carried by the support is 0.001 to 1 mmole, and based on 1 g of the support, the total amount of the cocatalyst compound carried by the support is 2 to 15 mmole.

8. The method for producing an olefin polymer according to claim 1, wherein, The olefin polymer is a copolymer of an olefin monomer and an olefin comonomer.

9. The method for producing an olefin 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 method for producing an olefin polymer according to claim 9, wherein, The olefin polymer is linear low-density polyethylene in which the olefin monomer is ethylene and the olefin comonomer is 1-hexene.

11. The method for producing an olefin polymer according to claim 1, wherein, The polymerization of the olefin monomer is carried out by gas-phase polymerization.

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