Method for solution polymerization of ethylene-alpha-olefin copolymer using transition metal compound

Abstract

The method for solution polymerization of an ethylene-alpha-olefin copolymer according to the present invention can produce an ethylene-alpha-olefin copolymer having a low viscosity of 20,000 cP or less, a molecular weight distribution of 3.0 or more, and a low molecular weight and also can produce an ethylene-alpha-olefin copolymer having said physical properties without the introduction of hydrogen or with the introduction of a small amount of hydrogen compared to the prior art.

Description

Solution polymerization method of ethylene-α-olefin copolymer using transition metal compounds

[0001] The present invention relates to a solution polymerization method for an ethylene-α-olefin copolymer.

[0002] Conventional catalysts used for polymerization of olefin-based polymers include metallocene catalysts and Ziegler-Natta catalysts, and the two conventional catalysts have different characteristics in terms of molecular weight, molecular structure, density, and melt flow index of the olefin-based polymers produced.

[0003] The above conventional metallocene catalyst is one of the catalysts used for ethylene polymerization in which a ligand such as cyclopentadienyl, cycloheptadienyl, indenyl, or fluorenyl is coordinated to a metal or a halogen compound on a metal, and the parent groups basically have a sandwich structure.

[0004] The above conventional metallocene catalyst is a compound having a constant structure, in which all active sites are uniform, and an ethylene polymer polymerization method using the same has the advantage of being able to produce an ethylene polymer having a narrow molecular weight distribution and a uniform distribution of comonomers.

[0005] In contrast, conventional Ziegler-Natta catalysts have non-uniform active sites due to the metal components dispersed on the solid surface being non-uniform, and therefore, an ethylene polymer polymerization method using the catalyst is suitable for polymerizing ethylene polymers having a high molecular weight distribution and various molecular structures.

[0006] Polymers used as materials for conventional films, containers, cables, pipes or fibers include both low molecular weight polymers and high molecular weight polymers, and in some cases, polymers having a high melt flow index and very low viscosity are required, and in these cases, a conventional polymerization method using a Ziegler-Natta catalyst may be preferred.

[0007] However, as described above, the conventional Ziegler-Natta catalyst has a non-uniform active site, and therefore, it is difficult for a person skilled in the art to precisely control the viscosity, molecular weight distribution, molecular structure, and repeating unit content of comonomer, etc. that are targeted, making it difficult to polymerize an olefin polymer having optimal properties for the material.

[0008] Accordingly, as described in the following patent document 1 (US Patent Publication No. US 5272236 A), a conventional method for polymerizing an olefin-based polymer using a metallocene catalyst has been known as a technology for controlling the properties of an olefin-based polymer to be polymerized by controlling various polymerization conditions such as reaction temperature, monomer input amount, oxygen input amount, and stirring speed.

[0009] However, the conventional polymerization method of olefin-based polymers using metallocene catalysts only controls the polymerization conditions, and thus cannot dramatically control the properties of the olefin-based polymers produced.

[0010] Therefore, there is a need for a new olefin polymerization method using a metallocene catalyst that can polymerize olefin polymers with high molecular weight distribution and low viscosity and whose properties can be easily controlled.

[0011] The purpose of the present invention is to provide a solution polymerization method for an ethylene-α-olefin copolymer capable of producing a transition metal compound having high activity and an ethylene-α-olefin copolymer having low viscosity, including the same.

[0012] Another object of the present invention is to provide a solution polymerization method for an ethylene-α-olefin copolymer capable of producing an ethylene-α-olefin copolymer having low viscosity even without adding hydrogen or by adding a very small amount of hydrogen.

[0013] Another object of the present invention is to provide a solution polymerization method for an ethylene-α-olefin copolymer capable of producing an ethylene-α-olefin copolymer having a low density.

[0014] Another object of the present invention is to provide a solution polymerization method for an ethylene-α-olefin copolymer capable of producing an ethylene-α-olefin copolymer having a broad molecular weight distribution.

[0015] Another object of the present invention is to provide an ethylene-α-olefin copolymer which can have low viscosity, low density, low molecular weight and broad molecular weight distribution.

[0016] As one embodiment of the present invention, the solution polymerization method of the ethylene-α-olefin copolymer is a solution polymerization method of the ethylene-α-olefin copolymer using a catalyst composition including a transition metal compound of the following chemical formula 1 and a cocatalyst, wherein the ethylene-α-olefin copolymer manufactured by adding hydrogen in an amount of 1000 ppm or less with respect to the total amount of input materials in the solution polymerization method of the ethylene-α-olefin copolymer may have a measured viscosity of 20,000 cP or less when the viscosity is defined as a value satisfying a torque value of 99% or more in a copolymer melted at 177°C using an SC-31 spin needle of a Brookfield DV2TLV viscometer.

[0017] [Chemical Formula 1]

[0018]

[0019] (In the above chemical formula 1, R1 and R2 are each independently a straight chain or branched C1-C7 alkyl, R3 and R4 are each independently a straight chain or branched C1-C7 alkyl, C6-C 12 Aryl or C7-C 20 Arylalkyl, R5 and R6 are each independently hydrogen or straight or branched C1-C4 alkyl, x and y are each independently an integer from 1 to 5, and M is titanium (Ti), zirconium (Zr), or hafnium (Hf).

[0020] As one embodiment of the present invention, in the chemical formula 1, R1 and R2 are each independently methyl, ethyl or n-butyl, R3 and R4 are each independently methyl, ethyl, n-butyl, phenyl or benzyl, R5 and R6 are each independently hydrogen or methyl, x and y are each independently integers from 1 to 5, and M may be Zr or Hf.

[0021] As one embodiment of the present invention, the ethylene-α-olefin copolymer may have a density of 0.9 g / cc or less as measured by ASTM D1505.

[0022] In another embodiment, the ethylene-α-olefin copolymer may have a density as measured by ASTM D1505 of 0.850 to 0.900 g / cc, 0.850 to 0.8850 g / cc, or 0.850 to 0.879 g / cc.

[0023] As one embodiment of the present invention, the ethylene-α-olefin copolymer may have a weight average molecular weight of 30,000 g / mol or less.

[0024] As another embodiment, the ethylene-α-olefin copolymer may have a weight average molecular weight of 10,000 to 30,000 g / mol, 15,000 to 30,000 g / mol.

[0025] As one embodiment of the present invention, the ethylene-α-olefin copolymer may have a molecular weight distribution of 3.0 or more.

[0026] As another embodiment, the molecular weight distribution may be 3.0 to 6.0, 3.0 to 5.0, or 3.0 to 4.5.

[0027] As one embodiment of the present invention, the ethylene-α-olefin copolymer may have 50 to 99 mol% of ethylene repeating units, 60 to 99 mol%, 70 to 99 mol%, or 80 to 99 mol%.

[0028] As one embodiment of the present invention, the cocatalyst may be at least one selected from N,N-diethylanilinium tetrakispentafluorophenylborate, N,N-2,4,6-pentamethylanilinium tetrakispentafluorophenylborate, and N,N-dimethylanilinium tetrakis3,5-bistrifluoromethylphenylborate.

[0029] As one embodiment of the present invention, the ethylene-α-olefin copolymer may be a copolymer comprising ethylene and at least one α-olefin selected from the group consisting of 1-octene, 1-hexene, and 1-butene.

[0030] As one embodiment of the present invention, the solution polymerization method of the ethylene-α-olefin copolymer may use at least one solvent selected from the group consisting of n-hexane, n-heptane, n-butane, n-pentane, n-octane, and cyclohexane.

[0031] As one embodiment of the present invention, the solution polymerization method of the ethylene-α-olefin copolymer may have a polymerization reaction temperature of 30 to 200°C.

[0032] As one embodiment of the present invention, the solution polymerization method of the ethylene-α-olefin copolymer may include the steps of a) preparing an α-olefin composition by mixing α-olefin in a solvent, and b) introducing a catalyst composition into the α-olefin composition and introducing ethylene into a reactor to copolymerize the ethylene-α-olefin copolymer.

[0033] As one embodiment of the present invention, the solution polymerization method of the ethylene-α-olefin copolymer may further include at least one aluminum scavenger selected from the group consisting of trimethylaluminum, triethylaluminum, tripropylaluminum, triisobutylaluminum, and trihexylaluminum.

[0034] According to the present invention, the solution polymerization method of the ethylene-α-olefin copolymer can produce an ethylene-α-olefin copolymer having a viscosity of 20,000 cP or less, and thus the produced ethylene-α-olefin copolymer has excellent biaxial stretching process or blow molding properties, and thus can have the effect of being usefully used as a film or a container.

[0035] According to the present invention, the solution polymerization method of the ethylene-α-olefin copolymer can be performed without or with hydrogen input, and as an example, even with a very small amount of hydrogen of 1,000 ppm or less based on the total amount of input, an ethylene ethylene-α-olefin copolymer having a viscosity of 20,000 cP or less can be produced, thereby achieving superior polymerization stability, a polymerization reactor with a small volume, and a short polymerization reaction time.

[0036] According to the present invention, the solution polymerization method of the ethylene-α-olefin copolymer can copolymerize ethylene-α-olefin copolymers having various molecular weights with a molecular weight distribution index (PDI) of 3 or more, so that the produced ethylene-α-olefin copolymer can be usefully used as a material for films, pipes, sheets, etc.

[0037] As one embodiment of the present invention, the solution polymerization method of the ethylene-α-olefin copolymer can produce an ethylene-α-olefin copolymer having a density measured by ASTM D1505 of 0.9 g / cc or less, 0.850 to 0.900 g / cc, or 0.850 to 0.879 g / cc, so that the produced ethylene-α-olefin copolymer can be usefully used as a material for articles requiring low density, such as beverage bottles.

[0038] The present invention will be described in more detail below. However, the following specific examples or examples are merely references for explaining the present invention in detail, and the present invention is not limited thereto, and may be implemented in various forms.

[0039] Additionally, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing specific embodiments only and is not intended to be limiting.

[0040] Additionally, the singular forms used in the specification and the appended claims are intended to include the plural forms as well, unless the context clearly dictates otherwise.

[0041] Additionally, when a part is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise specifically stated.

[0042] In addition, the terms "about", "substantially", etc. used in this specification are used in the sense of or close to the numerical value when manufacturing and material tolerances inherent to the meanings mentioned are presented, and are used to prevent unscrupulous infringers from unfairly exploiting the invention contents in which exact or absolute numerical values ​​are mentioned to aid understanding of the invention.

[0043] As one embodiment of the present invention, the solution polymerization method of the ethylene-α-olefin copolymer may be a method of producing an ethylene-α-olefin copolymer having a viscosity of 20,000 cP or less using a catalyst composition including a transition metal compound of the following chemical formula 1 and a cocatalyst.

[0044] [Chemical Formula 1]

[0045]

[0046] (In the above chemical formula 1, R1 and R2 are each independently a straight chain or branched C1-C7 alkyl, and R3 and R4 are each independently a straight chain or branched C1-C7 alkyl or C7-C 20Arylalkyl, R5 and R6 are each independently hydrogen or straight or branched C1-C4 alkyl, x and y are each independently an integer from 1 to 5, and M is titanium (Ti), zirconium (Zr), or hafnium (Hf).

[0047] As one embodiment of the present invention, the ethylene-α-olefin copolymer may have a viscosity of 20,000 cP or less, preferably 15,000 cP or less, more preferably 10,000 cP or less, or 9,000 cP or less, and although the lower limit is not limited, it may be 1,000 cP or more, 3,000 cP or more, or 5,000 cP or more.

[0048] An ethylene-α-olefin copolymer satisfying the viscosity in the above range may have excellent molding processability such as injection, extrusion or casting, and may be preferred in particular because it may be easy to use in a biaxially oriented film molding process or a blow molding process.

[0049] The viscosity measurement method of the above ethylene-α-olefin copolymer will be described in more detail in the examples to be described later, but may be measured using a Brookfield viscometer (Brookfield Engineering, DV2TLV) on an ethylene-α-olefin copolymer melted at 177°C, and may be measured by putting 10 g of the above ethylene-α-olefin copolymer into the sample chamber of the viscometer. In addition, the viscosity measurement method of the above ethylene-α-olefin copolymer may be one that satisfies a torque value of 99% or more when using an SC-31 spindle, but the above measurement method is only one example and is not necessarily limiting.

[0050] In one embodiment of the present invention, the ethylene-α-olefin copolymer may have a density measured by ASTM D1505 of 0.9 g / cc or less, preferably 0.88 g / cc or less, more preferably 0.879 g / cc or less or 0.875 g / cc or less, and although the lower limit is not limited, it may be 0.850 g / cc or more.

[0051] The above ethylene-α-olefin copolymer has a very low viscosity when melted at 177°C and a low density within the above range, so that films and containers can be manufactured with excellent processability, and can be manufactured with properties at a level that is commercially available for films and containers.

[0052] In one embodiment of the present invention, the ethylene-α-olefin copolymer may have a weight average molecular weight of 30,000 g / mol or less, in another embodiment, 27,000 g / mol or less or 25,000 g / mol or less, and although the lower limit is not limited, it may be 15,000 g / mol or more or 20,000 g / mol or more.

[0053] The above solution polymerization method of the ethylene-α-olefin copolymer can produce an ethylene-α-olefin copolymer having a lower weight average molecular weight than the conventional solution polymerization method of the ethylene-α-olefin copolymer using a transition metal compound, and thus can have a viscosity within the above range and a melt flow index within the range described below.

[0054] As one embodiment of the present invention, the ethylene-α-olefin copolymer may have a melt flow index of 500 g / 10 min or more at a load of 2.16 kg as measured by ASTM D1238, preferably 1,000 g / 10 min or more, more preferably 1,500 g / 10 min or more, and although the upper limit is not limited, it may have a melt flow index of 2,000 g / 10 min or less, or so high that it cannot be measured.

[0055] The melt flow index of the above ethylene-α-olefin copolymer was specifically measured according to ASTM D1238, and may be measured by melting the ethylene-α-olefin copolymer at 190°C and then measuring the melt flow index (g / 10 min) under the condition of a load of 2.16 kg.

[0056] The above ethylene-α-olefin copolymer may have a very low weight average molecular weight of 30,000 g / mol or less depending on one implementation, and therefore may have a very high melt flow index that cannot be measured using a conventional melt flow index measurement method.

[0057] As one embodiment of the present invention, the ethylene-α-olefin copolymer may have a molecular weight distribution of 3.0 or more, 3.1 or more, preferably 4.0 or more, more preferably 4.3 or more, and although the upper limit is not limited, it may be 5.0 or less or 4.5 or less.

[0058] Since the above ethylene-α-olefin copolymer can have a low weight average molecular weight in the above range, a resin containing both a low molecular weight ethylene-α-olefin copolymer and a high molecular weight ethylene-α-olefin copolymer can be provided, and the provided resin can be usefully used as a film and a container manufactured with excellent processability such as high biaxial stretching molding and blow molding.

[0059] As one embodiment of the present invention, the ethylene-α-olefin copolymer may be a copolymer of ethylene and at least one α-olefin selected from the group consisting of 1-octene, 1-hexene, and 1-butene, and as another embodiment, the α-olefin may be 1-octene, 1-hexene, or a mixed monomer thereof, or may be 1-octene, but is not necessarily limited thereto.

[0060] In one embodiment of the present invention, the ethylene-α-olefin copolymer may have 50 to 99 mol% of ethylene repeating units based on the total repeating units, and in another embodiment, may have 60 to 99 mol% or 70 to 99 mol%, but is not necessarily limited thereto.

[0061] An ethylene-α-olefin copolymer containing α-olefin repeating units in the above range may have excellent mechanical strength and high heat-sealability, and thus may be advantageously used as a heat-sealable film.

[0062] As one embodiment of the present invention, the ethylene-α-olefin copolymer can be produced by using a catalyst composition including a transition metal compound represented by the following chemical formula 1 and a cocatalyst, thereby satisfying the above-described physical properties.

[0063] [Chemical Formula 1]

[0064]

[0065] (In the above chemical formula 1, R1 and R2 are each independently a straight chain or branched C1-C7 alkyl, and R3 and R4 are each independently a straight chain or branched C1-C7 alkyl or C7-C 20 Arylalkyl, R5 and R6 are each independently hydrogen or straight or branched C1-C4 alkyl, x and y are each independently an integer from 1 to 5, and M is titanium (Ti), zirconium (Zr), or hafnium (Hf).

[0066] A transition metal compound satisfying the above structure may be preferred because it can produce an ethylene-α-olefin copolymer having a very low viscosity by including the ligand structure satisfying the above chemical formula 1, even if the activated metal (M in chemical formula 1) is not hydrogenated.

[0067] As one embodiment of the present invention, in the chemical formula 1, R1 and R2 are each independently methyl, ethyl or n-butyl, R3 and R4 are each independently methyl, ethyl, n-butyl, phenyl or benzyl, R5 and R6 are each independently hydrogen or methyl, x and y are each independently integers from 1 to 5, and M may be Zr or Hf.

[0068] When the above transition metal compound has the structure of the chemical formula 1 described above, it can have high activation and rapid chain transfer reaction even without hydrogenation of the activating metal M. Therefore, an ethylene-α-olefin copolymer manufactured by including the above-described transition metal compound can have a lower viscosity without adding hydrogen during the polymerization process, which is preferred.

[0069] In one embodiment of the present invention, the transition metal compound may have an activity of 400 to 600 kg(mPo) / g·hr(cat), and in another embodiment, it may have an activity of 400 to 500 kg(mPo) / g·hr(cat).

[0070] The activity of the above transition metal compound may be the content (kg) of ethylene-α-olefin copolymer (mPo) produced per hour relative to the content (g) of the transition metal compound (cat) included in the solution polymerization method of the ethylene-α-olefin copolymer, and the above transition metal compound may satisfy the activity in the above range even if the active metal (M in Chemical Formula 1) is hydrogenated or not.

[0071] Since the above transition metal compound has an activity in the above range, solution polymerization of an ethylene-α-olefin copolymer using the same can have excellent polymerization reactivity, and the transition metal compound having the above structure can have excellent copolymerization reactivity, and the solution polymerization method of an ethylene-α-olefin copolymer using the same can produce a low-viscosity ethylene-α-olefin copolymer with only a small amount of hydrogen input.

[0072] As one embodiment of the present invention, the solution polymerization method of the ethylene-α-olefin copolymer may be such that the amount of hydrogen input is 1,000 ppm or less with respect to the total amount of input materials, and in another embodiment, it may be such that the amount of hydrogen input is 500 ppm or less, or no hydrogen is input.

[0073] The above input may refer to all compounds input to the reaction, such as solvent, monomer, scavenger, catalyst composition, and hydrogen, which are input to the polymerization reactor.

[0074] Since the above transition metal compound has high activity even without adding hydrogen, a solution polymerization method of an ethylene-α-olefin copolymer including the same can produce a low-viscosity ethylene-α-olefin copolymer even without adding hydrogen or with a very small amount of hydrogen, and thus can have excellent polymerization stability, a polymerization device with a small volume, and a shorter polymerization time, and thus can be preferred.

[0075] As one embodiment of the present invention, the cocatalyst may be any one or more selected from the group consisting of N,N-diethylanilinium tetrakispentafluorophenylborate, N,N-2,4,6-pentamethylanilinium tetrakispentafluorophenylborate, and N,N-dimethylanilinium tetrakis3,5-bistrifluoromethylphenylborate, etc., as long as it is recognizable by a person skilled in the art, but is not particularly limited thereto.

[0076] In another embodiment of the present invention, the cocatalyst may be N-diethylanilinium tetrakispentafluorophenylborate or N,N-2,4,6-pentamethylanilinium tetrakispentafluorophenylborate, or N-diethylanilinium tetrakispentafluorophenylborate may be used alone.

[0077] The above N-diethylanilinium tetrakispentafluorophenylborate may be preferred because it may have excellent compatibility with the above-described transition metal compound, but is not necessarily limited thereto.

[0078] As one embodiment of the present invention, the catalyst composition may have a molar ratio of the transition metal compound and the cocatalyst of 1:5 to 1:10, and as another embodiment, it may be 1:5 to 1:8 or 1:5 to 1:7.

[0079] A catalyst composition satisfying the above range of molar ratios may be preferred because the activity, selectivity and stability of the transition metal compound are increased, and thus a solution polymerization method of an ethylene-α-olefin copolymer using the catalyst composition may more easily control the weight average molecular weight of the produced ethylene-α-olefin copolymer, but this is not necessarily limited thereto.

[0080] In one embodiment of the present invention, the solution polymerization method of the ethylene-α-olefin copolymer may include the steps of a) preparing an α-olefin composition by mixing an α-olefin in a solvent, and b) introducing a catalyst composition into the α-olefin composition and introducing ethylene into a reactor to copolymerize the ethylene-α-olefin copolymer.

[0081] It may be preferred that the above manufacturing steps a) and b) are performed sequentially, but each of the above steps is an embodiment of the present invention, and is not necessarily limited thereto, as long as it does not impair the properties of the ethylene-α-olefin copolymer being manufactured.

[0082] As one embodiment of the present invention, the solvent may be at least one selected from the group consisting of n-hexane, n-heptane, n-butane, n-pentane, n-octane, and cyclohexane.

[0083] As another embodiment, the solvent may be n-hexane or cyclohexane, and n-hexane may be used alone in view of its excellent solubility in α-olefins, but this is not necessarily limited as long as it allows α-olefin dissolution and does not impair the properties of the ethylene-α-olefin copolymer produced.

[0084] In one embodiment of the present invention, the α-olefin composition may contain 0.1 to 1 M of α-olefin, and in another embodiment, it may contain 0.5 to 1 M, but this is not necessarily limited thereto.

[0085] As one embodiment of the present invention, the solution polymerization method of an ethylene-α-olefin copolymer may have an internal pressure of 10 to 50 bar in the reactor, and as another embodiment, it may be 20 to 40 bar.

[0086] The solution polymerization method of the above ethylene-α-olefin copolymer may preferably have an internal pressure in the reactor within the range described above in terms of the ethylene-α-olefin copolymer being manufactured having the target weight average molecular weight, content of ethylene repeating units, and molecular weight distribution, but this is not particularly limited as long as it is recognizable by a person skilled in the art.

[0087] As another embodiment of the present invention, the solution polymerization method of the ethylene-α-olefin copolymer may be such that ethylene is introduced at an internal pressure of 10 to 30 bar in the reactor, or may be introduced at 15 to 25 bar.

[0088] An ethylene-α-olefin copolymer manufactured by injecting ethylene at a pressure within the above range may be preferred because it may contain the target ethylene repeating unit and thus have the target properties.

[0089] As one embodiment of the present invention, the solution polymerization method of the ethylene-α-olefin copolymer may further include introducing an inert gas, and the gas may be introduced at an internal pressure of 10 to 40 bar, 10 to 30 bar, or 20 to 30 bar in the reactor.

[0090] The above inert gas may be introduced after ethylene is introduced into the reactor, and this may be preferred because the pressure inside the reactor, which is lowered due to consumption of ethylene in the step of copolymerizing the b) ethylene-α-olefin copolymer, can be maintained at 10 to 50 bar as described above.

[0091] The above inert gas is not particularly limited, but as a non-limiting example, may be one or more selected from helium, neon, and argon, and it may be preferred to use argon in terms of providing a safer solution polymerization method of ethylene-α-olefin copolymer.

[0092] As one embodiment of the present invention, the solution polymerization method of the ethylene-α-olefin copolymer may further include an aluminum scavenger, and it may be preferred to introduce the scavenger before introducing ethylene, a transition metal compound, and a cocatalyst.

[0093] The solution polymerization method of an ethylene-α-olefin copolymer further including the above aluminum scavenger may be preferred because it can produce a high-purity ethylene-α-olefin copolymer by removing oxygen, moisture, and impurities contained in the above α-olefin composition.

[0094] In one embodiment of the present invention, the aluminum scavenger may be any one or more selected from the group consisting of trimethylaluminum, triethylaluminum, tripropylaluminum, triisobutylaluminum, and trihexylaluminum, as long as it is recognizable by a person skilled in the art, but is not particularly limited thereto. In another embodiment, the use of triisobutylaluminum alone may be preferred because it enables the production of a higher purity ethylene-α-olefin copolymer.

[0095] As one embodiment of the present invention, the aluminum scavenger may be added in an amount of 0.5 to 2 μmol or 0.5 to 0.5 to 1.5 μmol per 1 liter of the α-olefin composition, but this is not necessarily limited thereto.

[0096] As one embodiment of the present invention, the solution polymerization method of the ethylene-α-olefin copolymer may have a polymerization reaction temperature of 30 to 200°C, 30 to 150°C, or 30 to 100°C, and in another embodiment, 50 to 100°C, or 60 to 80°C.

[0097] The polymerization temperature in the above range can be preferred because it allows the transition metal compound to have high activity, so that the polymerization process of the solution polymerization method of the ethylene-α-olefin copolymer can be excellent, and the content of unreacted ethylene and α-olefin is small, so that the volume of the process and process equipment for recycling unreacted monomers can be reduced. However, this is not necessarily limited as long as it does not impair the physical properties of the ethylene-α-olefin copolymer produced.

[0098] The present invention will be described in more detail based on the following examples and comparative examples. However, the following examples and comparative examples are merely illustrative examples for further explaining the present invention, and the present invention is not limited by the following examples and comparative examples.

[0099] [measurement method]

[0100] 1. GPC (gel permeation chromatography) measurement

[0101] The measurement solution of ethylene-α-olefin copolymer dissolved in trichlorobenzene was measured using GPC (Polymer Char, GPC-6). The weight average molecular weight and molecular weight distribution (PDI) were obtained by controlling the ethylene-α-olefin copolymer at 160°C and a flow rate of 1.0 ml / min using a column (Agilent, PLgel olexis).

[0102] 2. Viscosity measurement

[0103] The ethylene-α-olefin copolymer was introduced into the sample chamber of a Brookfield DV2TLV viscometer, and the viscosity was measured using an SC-31 spin needle at a value satisfying a torque value of 99% or more in the ethylene-1-octene copolymer melted at 177°C.

[0104] 3. Density measurement

[0105] Measured according to ASTM D1505.

[0106] [Manufacturing Example 1]

[0107]

[0108] 3.00 g (14.5 mmol) of 2-methyl-7-phenyl-1H-indene was dissolved in 30 ml of diethyl ether, and 4.7 ml of a hexane solution of 1.6 M n-Butyllithium was slowly added at room temperature, and the mixture was stirred at the initial reactor temperature for 12 hours. The stirred solution was then cooled to -30 °C, 0.94 g (7.3 mmol) of dichlorodimethylsilane was slowly added, the solution was warmed to room temperature again, and stirred for 12 hours. The stirred solution was filtered, and the filtered solution was dried in an oven to obtain 3.2 g (6.9 mmol) of compound A in a yield of 95%.

[0109]

[0110] Afterwards, 1.0 g (2.13 mmol) of the obtained compound A was dissolved in 20 ml of ether, and 2.6 ml of a hexane solution of 1.6 M n-Butyllithium was slowly added at -30 °C. The mixture was then warmed to room temperature and stirred for 12 hours, and the temperature was lowered again to -30 °C, after which 496 mg (2.13 mmol) of ZrCl4 was added. The mixture was then warmed to room temperature again and stirred for 12 hours to perform the reaction. After completion of the reaction, the solvent was dried, and the dried reactant was immersed in toluene to wash away residual impurities, and then dried in an oven to remove toluene, obtaining 224 g of compound B in a yield of 15%. The NMR measurement results of the obtained compound [1H-NMR (CDCl3, 300 MHz)] were confirmed to be 7.68-6.83 (m, 18H), 2.46 (s, 3H), 2.26 (s, 3H), 1.48-1.26 (m, 6H).

[0111]

[0112] Finally, 0.1 g (0.16 mmol) of the obtained compound B was dissolved in 2 ml of toluene, and then, after cooling to -30°C, 0.16 ml of a 3.0 M ether solution of methylmagnesium bromide was slowly added. After warming to room temperature, the mixture was stirred for 12 hours to react. After completion of the reaction, the solvent was dried and the mixture was immersed in hexane to wash away impurities, and then dried in an oven to obtain 375 mg of the compound of Preparation Example 1 with a yield of 82%. The obtained Preparation Example 1 was confirmed as a result of NMR measurement [1H-NMR (C6D6, 300 MHz)] 7.76-6.82 (m, 18H), 1.97 (s, 6H), 0.78 (s, 6H), -0.78 (s, 6H).

[0113] [Manufacturing Example 2]

[0114]

[0115] In the above Manufacturing Example 1, 0.1 g (0.16 mmol) of compound B was dissolved in 2 ml of toluene, and then, while cooled to -30°C, 0.48 ml of a 1.0 M ether solution of benzylmagnesium bromide was slowly added. After the temperature was raised to room temperature, the mixture was stirred for 12 hours and reacted. After completion of the reaction, the solvent was dried and impurities were washed away by immersion in hexane, and then dried in an oven to obtain 69 mg of Manufacturing Example 2 with a yield of 58%. As a result of NMR measurement of the obtained manufacturing example 2, [1H-NMR (C6D6, 300 MHz)] 7.46-6.24 (m, 18H), 1.99 (s, 6H), 1.13 (d, 2H), 0.82 (s, 6H), -0.30 (d, 3H) were confirmed.

[0116] [Comparative Manufacturing Example 1]

[0117]

[0118] In the above Manufacturing Example 1, the reaction was performed in the same manner except that 2-methyl-7-phenyl-1H-indene was used as 2-methyl-1H-indene, and 121 mg of Comparative Manufacturing Example 1 was obtained in a yield of 48%.

[0119] [Comparative Manufacturing Example 2]

[0120]

[0121] In the above Manufacturing Example 2, the reaction was carried out in the same manner except that 2-methyl-7-phenyl-1H-indene was used as 1-(2-methyl-1H-inden-7-yl)naphthalene, and 102 mg of Comparative Manufacturing Example 4 was obtained with a yield of 23%.

[0122] [Comparative Manufacturing Example 3]

[0123]

[0124] In the above Manufacturing Example 1, the reaction was carried out in the same manner except that 2-methyl-7-phenyl-1H-indene was used as 1-(2-methyl-1H-inden-7-yl)naphthalene, and 21 mg of Comparative Manufacturing Example 3 was obtained in a yield of 32%.

[0125] [Comparative Manufacturing Example 4]

[0126]

[0127] In the above Manufacturing Example 2, the reaction was carried out in the same manner except that 2-methyl-7-phenyl-1H-indene was used as 1-(2-methyl-1H-inden-7-yl)naphthalene, and 102 mg of Comparative Manufacturing Example 4 was obtained in a yield of 23%.

[0128] [Comparative Manufacturing Example 5]

[0129] A transition metal compound of Comparative Manufacturing Example 5 represented by the following chemical formula 2 was prepared by reacting in the same manner as disclosed in U.S. Patent Publication No. US 5272236 A (November 29, 1993).

[0130] [Chemical Formula 2]

[0131]

[0132] [Examples 1 to 2 and Comparative Examples 1 to 5]

[0133] A 2-liter autoclave reactor was used to remove moisture and impurities inside the reactor using a vacuum pump and maintain a low pressure of 0.3 torr or less, and the temperature of the reactor was raised to 60°C while purging the reactor with argon (Ar) gas for more than 30 minutes.

[0134] A hexane solution containing 1-octene dissolved at a concentration of 0.8 M was introduced into a heated reactor, and 2 ml of triisobutyl aluminum (TiBAL) at a concentration of 1 M was introduced as a scavenger. The reactor was then stirred at a speed of 500 rpm and heated to 80°C. Once it reached 80°C, stirring was stopped, and 2 μmol of the catalyst shown in Table 1 below and ethylene gas were introduced into the reactor at a pressure of 20 bar. Argon was continuously introduced into the reactor to maintain a pressure of 25 bar after the introduction of the catalyst and ethylene, and 12 μmol of dimethylanilinium tetrakis(pentafluorophenyl)borate was additionally introduced as a cocatalyst into the pressurized reactor.

[0135] The temperature of the reactor, in which the cocatalyst and argon gas were maintained at a constant pressure, was raised from 80°C to 120°C to carry out a polymerization reaction, and 5 minutes after the polymerization reaction, the argon injection was stopped to terminate the reaction.

[0136] The molten polymer inside the reactor was transferred to a separator through the reactor outlet, unreacted ethylene and 1-octene were separated from the hexane solvent, and the polymer was dried in a vacuum oven at 80°C for 12 hours to obtain an ethylene-1-octene copolymer.

[0137] The obtained ethylene-1-octene copolymer was then measured using the above measurement method, and the measurement results are shown in Table 1 below.

[0138] [Examples 3 to 4 and Comparative Examples 6 to 8]

[0139] In the above Example 1, a hexane solution in which 1-octene was dissolved at a concentration of 0.8 M was introduced into the reactor at elevated temperature, 2 ml of triisobutyl aluminum (TiBAL) at a concentration of 1 M was introduced as a scavenger, and then 1,000 ppm of hydrogen was additionally introduced based on the total amount of the introduced input, and the reaction was conducted in the same manner except that the transition metal compound used was a transition metal compound of Table 1 below.

[0140] The obtained ethylene-1-octene copolymer was then measured using the above measurement method, and the measurement results are shown in Table 1 below.

[0141] Catalyst type Hydrogen input (ppm) Viscosity (cP) Weight average molecular weight (g / mol) PDI Density (g / cc) Example 1 Manufacturing example 1018,750 26,100 3.10.87 1 Example 2 Manufacturing example 208,670 21,2004.30.87 1 Example 3 Manufacturing example 11,000 8,427 20,330 3.50.87 1 Example 4 Manufacturing example 21,000 5,769 19,880 4.60.87 2 Comparative example 1 Comparative manufacturing example 10180,578 41,210 2.10.88 2 Comparative example 2 Comparative manufacturing example 2040,224 38,1542.80.880 Comparative example 3 Comparative manufacturing example 30270,54742,1201.80.879 Comparative Example 4 Comparative Manufacturing Example 4062,48732,1002.40.880 Comparative Example 5 Comparative Manufacturing Example 50298,00043,7911.80.880 Comparative Example 6 Comparative Manufacturing Example 11,000178,21438,2782.40.880 Comparative Example 7 Comparative Manufacturing Example 31,000254,57836,7362.20.878 Comparative Example 8 Comparative Manufacturing Example 51,000274,47839,1742.30.877

[0142] In Table 1 above, it was confirmed that Examples 1 and 2 had very low viscosities of 20,000 cP or less. This suggests that the solution polymerization method of ethylene-1-octene copolymer using the transition metal compound of Preparation Examples 1 and 2 can produce low-viscosity ethylene-1-octene copolymer without adding hydrogen.

[0143] In Table 1 above, Examples 1 and 2 have a low molecular weight with a weight average molecular weight of 30,000 g / mol or less and a wide molecular weight distribution with a PDI of 3.0 or more. In addition, it was confirmed that the ethylene-1-octene copolymers manufactured in Examples 1 and 2 have a low density of 0.9 g / cc or less, preferably 0.880 g / cc or less.

[0144] In contrast, in Table 1 above, Comparative Examples 1 to 5 confirmed that the viscosity of the ethylene-1-octene copolymers manufactured compared to Examples 1 and 2 exceeded 20,000 cP, the weight average molecular weight also exceeded 30,000 g / mol, and the molecular weight distribution was less than 3.0, or at worst, 2.0 or less.

[0145] In the above Examples 3 and 4, ethylene-α-olefin copolymers were produced by adding 1,000 ppm of hydrogen to the total amount of hydrogen added to the reactor. As shown in Table 1, it was confirmed that the viscosity of Examples 3 and 4 was further reduced.

[0146] Comparative Examples 6 to 8 above are examples of manufacturing ethylene-α-olefin copolymers using the transition metal compounds of Comparative Manufacturing Example 1, Comparative Manufacturing Example 3, and Comparative Manufacturing Example 5, and it was confirmed that the viscosity was very high even when 1,000 ppm of hydrogen was added to the total amount.

[0147] Therefore, the solution polymerization method of an ethylene-α-olefin copolymer using a transition metal compound according to the present invention can produce an ethylene-α-olefin copolymer having low viscosity, low molecular weight, and high molecular weight distribution even with a small amount of hydrogen added, or preferably without adding hydrogen, and the produced ethylene-α-olefin copolymer can satisfy a density of 0.9 g / cc or less.

[0148] As described above, the present invention has been described through specific matters and limited examples, but these are provided only to help a more general understanding of the present invention, and the present invention is not limited to the above examples, and those skilled in the art to which the present invention pertains can make various modifications and variations based on this description.

[0149] Therefore, the idea of ​​the present invention should not be limited to the described embodiments, and all things that are equivalent or equivalent to the following claims as well as the claims are considered to fall within the scope of the idea of ​​the present invention.

Claims

1. A solution polymerization method of an ethylene-α-olefin copolymer using a catalyst composition comprising a transition metal compound of the following chemical formula 1 and a cocatalyst, A solution polymerization method for an ethylene-α-olefin copolymer, wherein the viscosity of the above ethylene-α-olefin copolymer is defined as a value satisfying 99% or more of the torque value of the copolymer melted at 177°C using a Brookfield DV2TLV viscometer and an SC-31 spin needle, and the measured viscosity is 20,000 cP or less. [Chemical Formula 1] In the above chemical formula 1, R1 and R2 are independently straight or branched C1-C7 alkyl, R3 and R4 are independently straight or branched C1-C7 alkyl, C6-C 12 Aryl or C7-C 20 Arylalkyl, R5 and R6 are independently hydrogen or straight or branched C1-C4 alkyl, x and y are integers from 1 to 5, independently of each other, M is Ti, Zr or Hf.

2. In paragraph 1, A solution polymerization method for an ethylene-α-olefin copolymer, wherein in the above chemical formula 1, R1 and R2 are each independently methyl, ethyl or n-butyl, R3 and R4 are each independently methyl, ethyl, n-butyl, phenyl or benzyl, R5 and R6 are each independently hydrogen or methyl, x and y are each independently integers from 1 to 5, and M is Zr or Hf.

3. In paragraph 1, The above ethylene-α-olefin copolymer is a solution polymerization method of an ethylene-α-olefin copolymer having a density of 0.9 g / cc or less as measured by ASTM D1505.

4. In paragraph 1, The above ethylene-α-olefin copolymer is a solution polymerization method of an ethylene-α-olefin copolymer having a weight average molecular weight of 30,000 g / mol or less.

5. In paragraph 1, The above ethylene-α-olefin copolymer is a solution polymerization method of an ethylene-α-olefin copolymer having a molecular weight distribution of 3.0 or more.

6. In paragraph 1, The above ethylene-α-olefin copolymer is a solution polymerization method of an ethylene-α-olefin copolymer having 50 to 99 mol% of ethylene repeating units.

7. In paragraph 1, A solution polymerization method for an ethylene-α-olefin copolymer, wherein the cocatalyst is at least one selected from the group consisting of N,N-diethylanilinium tetrakispentafluorophenylborate, N,N-2,4,6-pentamethylanilinium tetrakispentafluorophenylborate, and N,N-dimethylanilinium tetrakis3,5-bistrifluoromethylphenylborate.

8. In paragraph 1, A solution polymerization method for an ethylene-α-olefin copolymer, wherein the above ethylene-α-olefin copolymer is copolymerized by including ethylene and at least one α-olefin selected from the group consisting of 1-octene, 1-hexene, and 1-butene.

9. In paragraph 8, The above α-olefin is a solution polymerization method for an ethylene-α-olefin copolymer which is 1-octene, 1-hexene or a mixed monomer thereof.

10. In paragraph 1, The solution polymerization method of the above ethylene-α-olefin copolymer is a solution polymerization method of an ethylene-α-olefin copolymer using at least one solvent selected from the group consisting of n-hexane, n-heptane, n-butane, n-pentane, n-octane, and cyclohexane.

11. In paragraph 1, The solution polymerization method of the above ethylene-α-olefin copolymer is a solution polymerization method of the ethylene-α-olefin copolymer having a polymerization reaction temperature of 30 to 200°C.

12. In paragraph 1, The solution polymerization method of the above ethylene-α-olefin copolymer comprises the steps of: a) preparing an α-olefin composition by mixing α-olefin in a solvent; and b) A solution polymerization method for an ethylene-α-olefin copolymer, comprising the steps of: adding a catalyst composition to the above α-olefin composition, and introducing ethylene into a reactor to copolymerize an ethylene-α-olefin copolymer.

13. In paragraph 1, A solution polymerization method for an ethylene-α-olefin copolymer, wherein the solution polymerization method for an ethylene-α-olefin copolymer further comprises at least one aluminum scavenger selected from the group consisting of trimethylaluminum, triethylaluminum, tripropylaluminum, triisobutylaluminum, and trihexylaluminum.

14. In paragraph 1, The solution polymerization method of the above ethylene-α-olefin copolymer is a solution polymerization method of an ethylene-α-olefin copolymer, wherein in step b), additional hydrogen is added, but the amount of hydrogen added is 1000 ppm or less with respect to the total amount of added materials.

15. An ethylene-α-olefin copolymer, wherein the copolymer has 50 to 99 mol% of ethylene repeating units, a density measured by ASTM D1505 of 0.85 to 0.90 g / cc, a weight average molecular weight of 10,000 to 30,000 g / mol, and a molecular weight distribution of 3.0 to 6.0.

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