KR101818371B1 - Tandem catalyst system and preparation method for polyethylene using the system - Google Patents

Abstract

Disclosed are a transition metal compound for alpha-olefin synthesis which enables synthesis of alpha-olefin from ethylene, and a tandem catalyst composition for polyethylene production including the transition metal compound. The present invention provides a catalyst composition for polyethylene production comprising: (A) a first transition metal catalyst for olefin oligomerization including a ligand compound represented by chemical formula 1 or 2, a chromium compound, and a metal alkyl compound; (B) a second transition metal catalyst which is capable of polymerizing ethylene and alpha-olefin; and (C) a co-catalyst which activates the first transition metal catalyst and the second transition metal catalyst. The catalyst composition according to the present invention enables polyethylene having low density and uniform composition to be produced from ethylene only without using a separate comonomer by enabling alpha-olefin to be prepared at higher activity and selectivity than an existing oligomerized catalyst compound.

Description

TECHNICAL FIELD [0001] The present invention relates to a tandem catalyst system and a method of manufacturing the same. BACKGROUND ART < RTI ID = 0.0 > TANDEM CATALYST < / RTI > SYSTEM AND PREPARATION METHOD FOR POLYETHYLENE USING THE SYSTEM &

The present invention relates to a tandem catalyst system and a method for producing polyethylene using the tandem catalyst system. More particularly, the present invention relates to a tandem catalyst system and a method for producing polyethylene through the alpha-olefin oligomerization reaction.

Polyethylene is a polymer compound produced by the polymerization of ethylene and is classified into low density polyethylene (LDPE) and high density polyethylene (HDPE) depending on its density. Generally, ethylene and a catalyst are used for the production of polyethylene, and alpha-olefins such as 1-hexene are used as comonomers for the purpose of controlling the density of the polymer. However, recently, as demand and supply of comonomers have been unstable and price fluctuations have been intensified, various methods for preparing polyethylene having necessary physical properties by controlling the catalyst system without using comonomers have been proposed.

For example, U.S. Patent No. 6,586,550 discloses a tandem catalyst system comprising an oligomerization catalyst of ethylene and a polymerization catalyst. However, when the oligomerization catalyst is used, the catalyst system may not be uniform in composition even when polyethylene having the same density is produced, and it is not easy to control the reaction in which ethylene is oligomerized to form alpha-olefin .

As another example, U.S. Patent No. 7,214,749 discloses that a polymer having a microstructure similar to linear LDPE can be obtained by ethylene homopolymerization using a specific constrained geometry catalyst. Although the technology according to the patent document has an advantage of using a single kind of catalyst, it has disadvantages that it is difficult to produce a polymer having homogeneous physical properties because branches generated in the polymer are irregular.

As another example, in a non-patent document (Tobin J. Marks et al. / J. Am. Chem. Soc. / 2002, 124, 13966), borate co- The results of the tandem catalyzed polymerization are obtained by using the catalyst. However, since the use of the unconjugated dinuclear co-catalyst and the atmospheric pressure condition are very economical in the use of the catalyst, the practical application of the catalyst may be difficult.

Therefore, there is an urgent need to develop a catalyst system capable of producing polyethylene having homogeneous physical properties without using a comonomer.

The present invention provides a transition metal compound for alpha-olefin synthesis and a tandem catalyst composition for the production of polyethylene comprising the same, which enables the synthesis of alpha-olefin from ethylene.

The present invention also provides a process for producing polyethylene comprising the step of polymerizing ethylene in the presence of a tandem catalyst composition.

(A) a first transition metal catalyst for olefin oligomerization comprising a ligand compound, a chromium compound and a metal alkyl compound represented by the following general formula (1) or (2); (B) a second transition metal catalyst capable of polymerizing ethylene and an alpha olefin; And (C) a cocatalyst for activating the first transition metal catalyst and the second transition metal catalyst.

[Chemical Formula 1]

(2)

Wherein E1 and E2 are each independently an element of boron (B), carbon (C), nitrogen (N), oxygen (O), silicon (Si), phosphorus (P) or sulfur (S) At least one of E1 and E2 is boron (B), nitrogen (N), oxygen (O), silicon (Si), phosphorus (P) or sulfur (S) Wherein R 1 to R 6 each independently represent hydrogen, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms, An alkylsilyl group having 1 to 20 carbon atoms, a haloalkyl group having 1 to 20 carbon atoms, an aryl (Aryl) group having 6 to 40 carbon atoms, an arylalkyl group having 7 to 20 carbon atoms, An Arylsilyl group, an Alkylaryl group having 7 to 20 carbon atoms, an Aryloxy group having 6 to 20 carbon atoms, a Halogen group or an amino group)

Also, (A) the first transition metal catalyst is used for the reaction of synthesizing alpha-olefin from ethylene.

And the chromium compound is chromium (III) or chromium (II) containing compound.

Also, the metal alkyl compound is at least one selected from the group consisting of an alkyl aluminum compound, an alkyl boron compound, an alkyl magnesium compound, an alkyl zinc compound, and an alkyl lithium compound.

The alkylaluminum compound may also be selected from the group consisting of triethylaluminum, tripropylaluminum, tributylaluminum, diethylaluminum chloride, diethylaluminum bromide, diethylaluminum ethoxide, diethylaluminum phenoxide, ethylaluminum dichloride and ethylaluminum sesquichloride And at least one member selected from the group consisting of a catalyst component and a catalyst component.

And the molar ratio of the ligand compound, the chromium compound, and the metal alkyl compound is 0.5: 1: 1 to 5: 1: 3,000 based on the chromium compound.

And wherein the alpha olefin is 1-hexene or 1-octene.

The second transition metal catalyst (B) is at least one selected from the group consisting of a Ziegler-Natta catalyst, a chromium catalyst, a metallocene catalyst, and a constrained geometry catalyst. to provide.

The catalyst (C) is at least one selected from the group consisting of compounds represented by the following formulas (3) to (5).

(3)

(Wherein R ³ is an alkyl group having 1 to 10 carbon atoms and n is an integer of 1 to 70)

[Chemical Formula 4]

(Wherein R ⁴ , R ⁵ and R ⁶ are each independently an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms or a halogen group, and R ⁴ , R ⁵ and R ⁶ Is an alkyl group having from 1 to 10 carbon atoms.

[Chemical Formula 5]

[CD]

Wherein C is a metal or a nonmetal compound having a proton-binding cations or oxidation potential of Lewis Base, D is a compound of an element belonging to Groups 5 to 15 on the periodic table, to be.)

The compound of the above formula (3) may be prepared by reacting a compound represented by the general formula (1) with at least one selected from the group consisting of Methylaluminoxane, Ethylaluminoxane, Butylaluminoxane, Hexylaluminoxane, Octylaluminoxane and Decylaluminoxane Wherein the catalyst is at least one compound selected from the group consisting of

In addition, the compound of the above formula (4) may be used in combination with one or more compounds selected from the group consisting of trimethylaluminum, triethylaluminum, tributylaluminum, trihexylaluminum, trioctylaluminum, tridecylaluminum, Examples of the organic peroxide include dimethylaluminum methoxide, diethylaluminum methoxide, dibutylaluminum methoxide, dimethylaluminum chloride, diethylaluminum chloride, dibutylaluminum chloride, but are not limited to, chloride, methylaluminum dimethoxide, ethylaluminum dimethoxide, butylaluminum dimethoxide, methylaluminum dichloride, ethylaluminum dichloride, De (Ethylaluminum dichloride) and butyl aluminum dichloride provides a catalyst composition, characterized in that at least one compound selected from the group consisting of (Butylaluminum dichloride).

The compound of Chemical Formula 5 may be prepared by reacting trimethylammonium tetraphenylborate, triethylammonium tetraphenylborate, tripropylammonium tetraphenylborate, tributylammonium tetraphenylborate, tributylammonium tetraphenylborate, (Pentafluorophenyl) borate, triethylammonium tetrakis (pentafluorophenyl) borate, tripropylammonium tetrakis (pentafluorophenyl) borate, and triethylammonium tetrakis (Pentafluorophenyl) borate, tributylammonium tetrakis (pentafluorophenyl) borate, anilinium tetraphenylborate, anilinium tetrakis (pentafluorophenyl) borate, Anilinium tetrakis (pentafluorophenyl) borate, pyridinium tetraphenylborate, pyridinium tetrakis (pentafluorophenyl) borate, ferrocenium tetrakis (pentafluorophenyl) But are not limited to, tetrakis (pentafluorophenyl) borate, silver tetraphenylborate, silver tetrakis (pentafluorophenyl) borate, tris (pentafluorophenyl) Tetrafluorophenyl) borane, tris (2,3,5,6-tetrafluorophenyl) borane, tris (2,3,5,6-tetrafluorophenyl) borane, 3,4,5-tetraphenylphenyl) borane and tris (3,4,5-trifluorophenyl) borane (Tris (3,4, 5-trifluorophenyl) borane), which is one or more compounds selected from the group consisting of It provides a catalyst composition of.

The second transition metal catalyst (B) is contained in a molar ratio of 1: 0.001 to 1: 5 based on the transition metal atom contained in each compound with respect to the first transition metal catalyst (A) The cocatalyst is contained in a molar ratio of 1: 1 to 1: 10,000 based on the transition metal atom contained in each compound with respect to the (A) first transition metal catalyst.

The present invention also provides a catalyst composition, characterized by further comprising a carrier on which the first transition metal catalyst (A), the second transition metal catalyst (B), and the cocatalyst (C) are supported.

The carrier may also be selected from the group consisting of silica, alumina, magnesium chloride, calcium chloride, bauxite, zeolite, magnesium oxide, zirconium oxide, titanium oxide, boron trioxide, calcium oxide, zinc oxide, barium oxide, And at least one selected from the group consisting of the catalyst component and the catalyst component.

According to another aspect of the present invention, there is provided a process for producing polyethylene, comprising polymerizing ethylene in the presence of the catalyst composition.

(A) forming an alpha-olefin from ethylene in the presence of a first transition metal catalyst; And (B) supplying a second transition metal catalyst and ethylene to the alpha-olefin formation reaction system to form a copolymer of alpha-olefin and ethylene.

And wherein the polymerized copolymer has a density of 0.960 g / cc or less.

The tandem catalyst system according to the present invention enables the production of alpha-olefins with high activity and selectivity compared to conventional oligomerization catalyst compounds, so that the production of polyethylene having low density and homogeneous composition with ethylene alone without using any other comonomer It is possible.

Hereinafter, preferred embodiments of the present invention will be described in detail. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. Throughout the specification, when an element is referred to as "including " an element, it means that it can include other elements, not excluding other elements, unless specifically stated otherwise.

According to one aspect of the present invention, a ligand compound; Chromium compounds; (B) capable of polymerizing ethylene and an alpha olefin; (C) a second transition metal catalyst (B) capable of polymerizing ethylene and an alpha olefin; and (C) a second transition metal catalyst And a promoter (C) for activating the second transition metal catalyst.

In the present invention, when the first transition metal catalyst is applied to a tandem catalyst system together with a conventional transition metal compound (B) applied to alpha-olefin and ethylene copolymerization, ethylene alone can be used at low density It was confirmed that polyethylene having a uniform composition can be produced.

In the present invention, the ligand compound is a compound represented by the following formula (1) or (2).

[Chemical Formula 1]

(2)

In the general formulas (1) and (2), E1 and E2 are each independently an element of boron (B), carbon (C), nitrogen (N), oxygen (O), silicon (Si), phosphorus (P) At least one of E1 and E2 may be boron (B), nitrogen (N), oxygen (O), silicon (Si), phosphorus (P) or sulfur (S) ) And E2 may be oxygen (O).

B1 may be aluminum (Al), boron (B), nitrogen (N), or phosphorus (P) element, preferably aluminum (Al).

 Each of R 1 to R 6 is independently hydrogen, an alkyl (Alky) group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an alkylsilyl group having 1 to 20 carbon atoms, An aryl group having 6 to 40 carbon atoms, an arylalkyl group having 7 to 20 carbon atoms, an arylsilyl group having 6 to 20 carbon atoms, an alkylaryl group having 7 to 20 carbon atoms ( Alkylaryl group, an aryloxy group having 6 to 20 carbon atoms, a halogen group or an amino group. Wherein the aryl group is optionally substituted with at least one substituent selected from the group consisting of phenyl, biphenyl, triphenyl, triphenylene, naphthalenyl, anthracenyl, phenalenyl, phenanthrenyl, fluorenyl, pyrenyl, Aromatic hydrocarbon functional groups, dibenzothiophenyl, dibenzofuranyl, dibenzoselenophenyl, furanyl, thiophenyl, benzofuranyl, benzothiophenyl, benzoselenophenyl, carbazonyl, indolocarbazolyl, Pyridyl, pyridyl, pyridyl, pyridyl, pyridyl, pyridyl, pyridyl, pyridyl, pyridyl, pyridyl, pyridyl, pyridyl, pyridyl, pyrimidinyl, Pyrimidyl, pyrazinyl, triazinyl, oxazinyl, oxathiazinyl, oxadiazinyl, indolinine, benzimidazolyl, indazolyl, indoxazinyl, benzoxazolyl, benzisoxazolyl, benzothiazolyl, quinolyl Nin, isoquinolinyl, cinnolinyl, quinazolyl, quinoxalinine, But are not limited to, phthalidyl, phthalazinyl, phthalidinyl, xanthenyl, acridyl, phenazinyl, phenothiazinyl, phenoxazinyl, benzofuropyridyl, furodipyridyl, benzothienopyridyl, Aromatic heterocyclic functional groups such as benzenesulfonylphenidyl, benzoselenophenopyridyl, selenophenodipyridyl, and the like.

R 1 to R 6 in Formula 1 are preferably hydrogen, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group, or an aryl group in view of stabilization of the central metal.

The term " olefin oligomerization " as used herein means that the olefin is polymerized. It is called "trimerization" and "tetramerization" according to the number of olefins to be polymerized, and is collectively referred to as "multimerization". In particular, the present invention can mean selectively producing 1-hexene and 1-octene from ethylene.

In addition, the first transition metal catalyst may be a mixture of the ligand compound, the chromium compound, and the metal alkyl compound, regardless of whether the composition is a simple mixture of the ligand compound, the chromium compound, and the metal alkyl compound, Any composition, compound or complex that exhibits catalytic activity for ' olefin oligomerization ' including catalytically active species may be collectively referred to.

The optional olefin oligomerization reaction is also closely related to the catalyst system used. The catalyst system used in the olefin oligomerization reaction includes a chromium compound serving as a main catalyst and a metal alkyl compound as a cocatalyst wherein the structure of the active catalyst can be changed according to the chemical structure of the ligand, The activity becomes different.

The present inventors have found that a ligand compound having a specific structure as described above and a catalyst system for olefin oligomerization comprising a metal compound as a chromium compound and a promoter can control the electronic and stereoscopic environment around a transition metal by suitably controlling the ligand compound Therefore, it has been confirmed through experiments that oligomerization of olefins with high catalytic activity and selectivity is possible, and the present invention has been completed.

Particularly, the ligand compound is a hexagonal ring compound. The ligand compound is a hexagonal ring compound, and includes boron (B), nitrogen (N), oxygen (O), silicon (Si), phosphorus (P), sulfur ). Due to such structural features, the ligand compound can be applied to oligomerization catalyst systems of olefins to exhibit a high oligomerization reaction activity, and particularly, 1-hexene and 1-octene Can exhibit a high degree of selectivity. This is presumably due to the interaction between each adjacent chromium active point.

In the present invention, the chromium compound may be one or more organic or inorganic compounds, wherein the chromium oxidation state is 0-6. In general, the chromium compound will have the general formula CrXn, where X can be the same or different and can be any organic or inorganic radical and n is an integer from 1 to 6. Representative organic radicals can have from about 1 to 20 carbon atoms per radical and are selected from the group consisting of alkyl, alkoxy, ester, ketone, and / or amido radicals. The organic radicals can be linear or branched, cyclic or acyclic, aromatic or aliphatic, and can be composed of mixed aliphatic, aromatic, and / or cycloaliphatic groups. Representative inorganic radicals include, but are not limited to, halides, sulfates, and / or oxides.

The chromium compound of the catalyst system for olefin oligomerization according to one embodiment of the present invention serves as a main catalyst, and it is preferable to use a compound containing chromium (III) or chromium (II) because the reaction activity can be enhanced.

Examples of the chromium (III) compound include chromium carboxylate, chromium naphthenate, chromium halide, chromium dionate and the like. More specific examples thereof include chromium (III) 2,2,6,6-tetramethylheptanedio (III) naphthenate [Cr (NP) 3], bis (2-ethylhexanoate), chromium ) Chromium (III) hydroxide, bis (2-butanoate) chromium (III) hydroxide, chromium (III) chloride, iodine chromium bromide, iodine chromium, chromium (III) acetylacetonate, chromium ) Acetate, chromium (Ⅲ) butyrate, chromium (Ⅲ) neopentanoate, chromium (Ⅲ) laurate, chromium (Ⅲ) stearate, chromium (Ⅲ) oxalate, bis (2-ethylhexanoate) III) hydroxide, and the like.

Specific examples of the chromium (II) compound include chromium bromide, chromium fluoride, chromium (II) chloride, chromium (II) acetate, chromium (II) (II) neopentanoate, chromium (II) laurate, chromium (II) stearate, chromium (II) oxalate and the like.

Meanwhile, the chromium compound may be in a state dissolved in a hydrocarbon solvent. The hydrocarbon solvent is an inert solvent which does not react with a chromium compound or a cocatalyst and may be selected from benzene, benzene, toluene, heptane, cyclohexane, methylcyclohexane, methylcyclopentane, hexane, pentane, butane, isobutane, But is not limited thereto.

(III) 2-ethylhexanoate, chromium (III) acetylacetonate or bis (2-ethylhexanoate) chromium (III) hydroxide is used as the chromium compound in the olefin oligomerization catalyst system of this embodiment , It is preferable to use it by dissolving it in anhydrous toluene or anhydrous cyclohexane solvent in view of the improvement of the catalytic activity by the difference in the solubility of the solvent.

In the present invention, the metal alkyl compound is not particularly limited as long as it can be used as a cocatalyst in an olefin oligomerization catalyst system and is generally used for mass-producing olefins under a transition metal compound catalyst. For example, as the metal alkyl compound, an alkyl aluminum compound, an alkyl boron compound, an alkyl magnesium compound, an alkyl zinc compound, an alkyl lithium compound and the like can be used.

However, in order to exhibit high selectivity and activity in the olefin oligomerization reaction, an alkylaluminum compound can be used as the above-described promoter compound. Specific examples of such alkylaluminum compounds include triethylaluminum, tripropylaluminum, tributylaluminum, diethyl There may be mentioned aluminum chloride, diethylaluminum bromide, diethylaluminum ethoxide, diethylaluminum phenoxide, ethylaluminum dichloride, ethylaluminum sesquichloride and the like, preferably triethylaluminum, ethylaluminum dichloride or ethylaluminum Sesquichloride can be mixed and used. In such a case, it is preferable to effectively remove moisture and improve catalytic activity including electron donating atoms.

The molar ratio of the ligand compound: chromium compound: metal alkyl compound is in the range of 0.5: 1: 1 to 10: 1 based on the chromium compound in order to increase the selectivity for the linear alpha-olefin and increase the mass- 1: 10,000, preferably 0.5: 1: 100 to 5: 1: 3,000. However, the present invention is not limited thereto.

In the catalyst system for olefin oligomerization comprising the ligand compound, the chromium compound and the metal alkyl compound, the three components may be used in combination with one or more precursors thereof, either simultaneously or in any order, in any suitable solvent, Can be added to give an active catalyst. Suitable solvents include, but are not limited to, heptane, toluene, cyclohexane, methylcyclohexane, 1-hexene, diethyl ether, tetrahydrofuran, acetonitrile, dichloromethane, chloroform, chlorobenzene, methanol and acetone.

According to an embodiment of the present invention, there is provided a process for preparing an olefin oligomer comprising the step of mass-reacting an olefin in the presence of the catalyst system for olefin oligomerization. The use of the catalyst system for olefin oligomerization according to one embodiment of the present invention can provide a method for oligomerization of olefins having improved reaction activity and selectivity. At this time, the olefin is preferably ethylene.

In the present invention, the olefin oligomerization is carried out by using the olefin oligomerization catalyst system and a conventional apparatus and contact technique, in a homogeneous liquid phase reaction in the presence or absence of an inert solvent, a slurry reaction in which the catalyst system is partially or completely dissolved, Liquid / liquid reaction or product phase reaction or gas phase reaction in which the olefin serves as the main medium, preferably a homogeneous liquid phase reaction can be employed.

The olefin oligomerization reaction may be carried out in any inert solvent that does not react with the catalyst compound and the activator. Suitable inert solvents include, but are not limited to, benzene, toluene, xylene, cumene, heptane, cyclohexane, methylcyclohexane, methylcyclopentane, hexane, pentane, butane and isobutane. At this time, the solvent may be treated with a small amount of alkylaluminum to remove a small amount of water or air acting as a catalyst poison.

The olefin oligomerization reaction may be carried out at a temperature of 0 to 250 ° C, preferably 20 to 200 ° C, more preferably 40 to 130 ° C. Excessively low reaction temperatures can produce, for example, undesirable insoluble products such as polymers in excess, and excessively high temperatures can cause decomposition of the catalyst system and reaction products, Do. In addition, the olefin oligomerization reaction can be carried out at a pressure of 1 to 200 bar, preferably 10 to 150 bar. Excessively low reaction pressures can result in low catalytic activity. In the process for preparing the olefin oligomer, hydrogen may be added to the reactor at 0.01 to 50 bar, preferably at 0.5 to 10 bar, in order to promote the reaction or to increase the activity of the catalyst system.

In the present invention, the (B) second transition metal catalyst is a catalyst component for copolymerization of ethylene and olefin series.

That is, the catalyst composition according to the present invention is a catalyst system usable in synthesizing polyethylene wherein the first transition metal catalyst comprised in the catalyst system is selected from alpha-olefins (especially 1-hexene and 1- Octene), and the produced alpha-olefin can be copolymerized with ethylene by the catalytic action of the second transition metal compound to produce polyethylene. Accordingly, the catalyst system enables the production of polyethylene having low density and uniform composition with only ethylene without using (adding) a separate comonomer.

In such a tandem catalyst system, the second transition metal catalyst may be applied without limitation to catalyst compounds which enable the copolymerization of alpha-olefin with ethylene in the art to which the present invention pertains. However, according to the present invention, the second transition metal compound may be at least one selected from the group consisting of a Ziegler-Natta catalyst, a chromium catalyst, a metallocene catalyst and a constrained geometry catalyst, Compound, and preferably a metallocene catalyst may be used.

The Ziegler-Natta catalyst may be a compound such as titanium trichloride or titanium tetrachloride. The chromium-based catalyst may be a compound such as chromium trioxide or bis (triphenylsilyl) chromate, and the metallocene The catalyst may be bis (cyclopentadienyl) zirconium chloride, bis (indenyl) zirconium chloride or the like, and the geometric constraining catalyst may be [Me ₂ Si (Me ₄ C ₅ ) NtBu] TiCl ₂ . However, the above-exemplified compounds are merely examples of compounds applicable to the catalyst system, and the examples are not intended to limit the scope of the present invention.

In the present invention, the cocatalyst (C) is a substance which reacts with the metal or transition metal precursor or ligand and the transition metal catalyst for polymerization to have a catalytic activity. Specifically, among the compounds represented by the following formulas Can be selected.

(3)

In Formula (3), R ³ is an alkyl group having 1 to 10 carbon atoms, and n is an integer of 1 to 70.

[Chemical Formula 4]

R ⁴ , R ⁵ and R ⁶ are each independently an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms or a halogen group, and R ⁴ , R ⁵ and R ⁶ Is an alkyl group having from 1 to 10 carbon atoms.

[Chemical Formula 5]

[CD]

In Chemical Formula 5, C is a metal or nonmetal compound having a proton-binding cations or oxidation potential of Lewis Base, and D is a compound of an organic material and an element belonging to Groups 5 to 15 in the periodic table .

The cocatalysts of the formulas (3) to (5) serve to cationize or activate the central metal of the transition metal compound, which is the main catalyst, so that ethylene reacts well with the core metal. The compound represented by Formula 3 may have a chain, cyclic or network structure. Non-limiting examples of the compound include methylaluminoxane, ethylaluminoxane, butylaluminoxane, Butylaluminoxane, hexylaluminoxane, octylaluminoxane, decylaluminoxane, and the like.

Examples of the compound represented by Formula 4 include, but are not limited to, trimethylaluminum, triethylaluminum, tributylaluminum, trihexylaluminum, trioctylaluminum, But are not limited to, tridecylaluminum, dimethylaluminum methoxide, diethylaluminum methoxide, dibutylaluminum methoxide, dimethylaluminum chloride, diethylaluminum chloride, Dibutylaluminum chloride, Methylaluminum dimethoxide, Ethylaluminum dimethoxide, Butylaluminum dimethoxide, Methylaluminum dichloride, Methylaluminum dichloride, ide, ethylaluminum dichloride, butylaluminum dichloride, and the like.

Non-limiting examples of the compound represented by Formula 5 include trimethylammonium tetrakis (pentafluorophenyl) borate, triethylammonium tetrakis (pentafluorophenyl) borate, triethylammonium tetrakis (pentafluorophenyl) pentafluorophenyl) borate, tripropylammonium tetrakis (pentafluorophenyl) borate, tri (n-butyl) ammonium tetrakis (pentafluorophenyl) borate (Ttri tetrakis (pentafluorophenyl) borate, tri (sec-butyl) ammonium tetrakis (pentafluorophenyl) borate, tri (sec- butyl) ammonium tetrakis (pentafluorophenyl) borate, N, N-dimethylanilinium tetrakis N, N-dimethyltris (pentafluorophenyl) borate, N, N-dimethylanilinium n-butyltris (pentafluorophenyl) N, N-dimethylanilinium benzyltris (pentafluorophenyl) borate, N, N-dimethylanilinium tetrakis (4- (t (Butyldimethylsilyl) -2,3,5,6-tetrafluorophenyl) borate, N, N-dimethylanilinium tetrakis (4- (t- N-dimethyl anilinium tetrakis (4- (t-triisopropylsilyl) -2,3,5,6-tetrafluorophenyl) borate (N, N-dimethylanilinium tetrakis (4- , 5,6-tetrafluorophenyl) borate, N, N-dimethylanilinium pentafluorophenoxytris (pentafluorophenyl) borate, N, N-dimethylanilinium pentafluorophenoxytris N, N-dimethyl-2,4,6-trimethylanilinium tetrakis (pentafluorophenyl) borate (N, N-diethylanilinium tetrakis (pentafluorophenyl) N-dimethyl-2,4,6-trimethylanilinium tetrakis (pentafluorophenyl) borate, N, N-dimethylammonium tetrakis (2,3,5,6-tetrafluorophenyl) , 3,4,6-tetrafluorophenyl) borate, N, N-diethylammonium tetrakis (2,3,4,6-tetrafluorophenyl) borate (triethylammonium tetrakis borate, tripropylammonium tetrakis (2,3,4,6-tetrafluorophcnyl) borate, tri (n-butyl) ammonium tetrakis (triphenylphosphine) 2,3,4,6-tetrafluorophenyl) borate, dimethyl (t-butyl) ammonium tetrakis (2,3 , 4,6-tetrafluorophenyl) borate, dimethyl (t-butyl) ammonium tetrakis (2,3,4,6-tetrafluorophenyl) borate, N, N-dimethylanilinium tetrakis 6-tetrafluorophenyl) borate (N, N-dimethylanilinium tetrakis (2,3,4,6-tetrafluorophe nyl) borate, N, N-diethylanilinium tetrakis (2,3,4,6-tetrafluorophenyl) borate, , N, N-dimethyl 2,4,6-trimethylanilinium tetrakis (2,3,4,6-tetrafluorophenyl) 3,4,6-tetrafluorophenyl) borate).

In the case of dialkylammonium, it is also possible to use di- (i-propyl) ammonium tetrakis (pentafluorophenyl) borate (di- (i-propyl) ammonium tetrakis (pentafluorophenyl) borate), dicyclohexylammonium tetrakis Dicyclohexylammonium tetrakis (pentafluorophenyl) borate), and the like.

In the case of trialkylphosphonium, triphenylphosphonium tetrakis (pentafluorophenyl) borate, tri (o-tolylphosphonium tetrakis (pentafluorophenyl) borate tri (o-tolylphosphonium tetrakis (pentafluorophenyl) borate, tri (2,6-dimethylphenyl) phosphonium tetrakis (pentafluorophenyl) borate and the like.

In the case of dialkyl oxonium, diphenyloxonium tetrakis (pentafluorophenyl) borate, di (o-tolyl) oxonium tetrakis (pentafluorophenyl) borate (di tetrakis (pentafluorophenyl) borate, di (2,6-dimethylphenyloxonium tetrakis (pentafluorophenyl) borate), and the like. have.

Also, in the case of dialkylsulfonium, diphenylsulfonium tetrakis (pentafluorophenyl) borate, di (o-tolyl) sulfonium tetrakis (pentafluorophenyl) borate (di bis (2,6-dimethylphenyl) sulfonium tetrakis (pentafluorophenyl) borate, and the like can be used. .

In the case of the carbonium salt, tropylium tetrakis (pentafluorophenyl) borate, triphenylmethylcarbenium tetrakis (pentafluorophenyl) borate, triphenylmethylcarbenium tetrakis (pentafluorophenyl) (Diazonium) tetrakis (pentafluorophenyl) borate (benzene (diazonium) tetrakis (pentafluorophenyl) borate).

Such a promoter compound is not limited to the above examples, and the catalyst of the present invention can be used singly or in combination of two or more.

On the other hand, in the catalyst composition according to the present invention, the amount of the co-catalyst (C) is sufficient to activate the second transition metal catalyst, and the specific content is not particularly limited. Type and content. However, according to the present invention, the co-catalyst compound is used in a molar ratio of 1: 1 to 1: 100,000, preferably 1: 1 to 1: 10,000, based on the central transition metal atom of the transition metal compound contained in the catalyst system ≪ / RTI > That is, it is advantageous from the viewpoint of improving the reaction efficiency that the above-mentioned co-catalyst compound is included in the above-mentioned range.

In the catalyst system of the present invention, the content ratio of the first transition metal catalyst and the second transition metal catalyst is determined by the oligomerization reaction of the alpha-olefin by the first transition metal catalyst and the alpha-olefin polymerization by the second transition metal catalyst, The efficiency of the copolymerization reaction of olefin and ethylene, and the like, so that it is not particularly limited. However, according to the present invention, the second transition metal catalyst is used in a molar ratio of 1: 0.001 to 1: 5, preferably 1: 0.005 to 1: 5, based on the transition metal atom contained in each compound, 1: 2.5, more preferably 1: 0.01 to 1: 2 in terms of improving the reaction efficiency.

The tandem catalyst system according to the present invention may further include a carrier on which the first transition metal catalyst, the second transition metal catalyst and the cocatalyst compound are supported.

The carrier is a porous organic / mucilaginous compound having fine pores on its surface or inside, and can be applied without limitation to those conventional in the art to which the present invention belongs. According to the present invention, however, the carrier is selected from the group consisting of silica, alumina, magnesium chloride, calcium chloride, bauxite, zeolite, magnesium oxide, zirconium oxide, titanium oxide, boron trioxide, calcium oxide, zinc oxide, barium oxide, And a complex of a compound represented by the following formula (1).

The method of supporting the transition metal catalyst and the promoter on the carrier may include a method of directly supporting the transition metal catalyst on a dehydrated carrier, a method of pretreating the carrier with the promoter compound, A method in which the transition metal catalyst is supported on the support, followed by post treatment with a promoter compound, a method in which the transition metal catalyst is reacted with a cocatalyst, and then a carrier is added to react.

Examples of the solvent applicable to the above-mentioned carrying method include pentane, hexane, heptane, octane, nonane, decane, undecane, Aromatic hydrocarbon solvents such as benzene, monochlorobenzene, dichlorobenzene, trichlorobenzene, toluene and the like, aromatic hydrocarbon solvents such as dichloromethane (dichloromethane, Halogenated aliphatic hydrocarbon solvents such as dichloromethane, trichloromethane, dichloroethane and trichloroethane, and mixtures thereof.

The step of carrying the transition metal compound and the promoter compound on the carrier is advantageously carried out at a temperature of 0 to 120 캜, preferably 20 to 100 캜, from the viewpoint of efficiency of the supporting step.

Meanwhile, the tandem catalyst system according to the present invention may further include an organic solvent.

The type of the organic solvent is not particularly limited, and a solvent known to be commonly used in the synthesis of polyethylene in the technical field of the present invention can be applied. Suitably, the organic solvent is selected from the group consisting of butane, pentane, hexane, heptane, octane, nonane, decane, undecane, Aromatic hydrocarbon solvents such as benzene, monochlorobenzene, dichlorobenzene, trichlorobenzene, toluene and the like, or aromatic hydrocarbon solvents such as dichloromethane, toluene, and the like; aliphatic hydrocarbons such as benzene, Halogenated aliphatic hydrocarbon solvents such as dichloromethane, trichloromethane, dichloroethane, and trichloroethane, and the like.

According to another aspect of the present invention, there is provided a process for producing polyethylene comprising polymerizing ethylene in the presence of the tandem catalyst system described above.

As the process for preparing polyethylene is carried out in the presence of the above-described tandem catalyst system, ethylene alone is used as a reaction raw material without using (adding) additional comonomers or additional compounds for controlling the density of the polymer, And polyethylene having a uniform composition can be produced.

The process for producing such polyethylene preferably comprises oligomerizing ethylene from ethylene in the presence of said first transition metal catalyst to form an alpha-olefin; And supplying the second transition metal catalyst and ethylene to the resulting alpha-olefin formation reaction system to form a copolymer of alpha-olefin and ethylene.

In the step of forming the alpha-olefin, the content of the first transition metal catalyst may be adjusted in consideration of the efficiency of the synthesis reaction of alpha-olefin, so that the specific content is not particularly limited. However, according to the present invention, the content of the first transition metal catalyst is preferably ^10-8 mol / kg to 1 mol / kg, preferably 10 ^-7 mol / kg, based on the transition metal atom, / Kg to 10 ^-1 mol / kg, more preferably 10 ^-7 mol / kg to 10 ^-2 mol / kg.

In addition, the co-catalyst compound is contained in a molar ratio of 1: 1 to 1: 10,000, preferably 1: 100 to 1: 3,000, based on the transition metal atom contained in the first transition metal catalyst, It is advantageous in terms of improvement.

The step of forming an alpha-olefin from the ethylene can be carried out by introducing the first transition metal catalyst, ethylene and a solvent into the reactor, in particular, trimerizing and quantifying ethylene to produce 1-hexene and 1-octene. At this time, the type of the solvent used in the alpha-olefin forming step is not particularly limited, but may be n-hexane, normal heptane, cyclohexane, toluene, benzene or a mixture thereof in accordance with the present invention.

In the step of forming the copolymer, the content of the second transition metal catalyst is not particularly limited as it can be controlled in consideration of the efficiency of copolymerization of alpha-olefin and ethylene. However, according to the present invention, the second transition metal catalyst is used in a molar ratio of 1: 0.001 to 1: 5, preferably 1: 0.005 to 1: 5, based on the transition metal atom contained in each compound, 1: 2.5, more preferably 1: 0.01 to 1: 2 in terms of improving the reaction efficiency.

On the other hand, in the step of forming the alpha-olefin, in particular, according to the present invention, when the first transition metal catalyst is used as a ligand, a chromium compound and an alkyl metal represented by Chemical Formula 1 or Chemical Formula 2, Chain alpha-olefins, 1-hexene and 1-octene can be more selectively synthesized.

The step of forming the copolymer may be carried out by applying a polymerization reaction such as a slurry phase, a solution phase, a gas phase, and a bulk phase. When the step of forming the copolymer is carried out in a liquid phase or slurry phase reaction, a solvent or a monomer itself can be used as a medium, and the solvent used at this time is as described above.

The step of polymerizing ethylene in the presence of the tandem catalyst system can be carried out under temperature and pressure conditions which are applied to the polymerization of conventional polyethylene. However, according to the present invention, the production method of the polyethylene can be carried out under a temperature condition of 0 to 300 ° C, preferably 15 to 200 ° C, under a pressure of 1 to 1,000 atm, preferably 2 to 200 atm . That is, the production method of the polyethylene is advantageously carried out under the temperature and pressure conditions in consideration of the minimum conditions required for the reactive expression of the ethylene monomer and the yield of the resulting polymer.

According to the production process of the present invention, polyethylene having a low density and uniform composition can be produced in a single process using only ethylene as a reaction raw material without using any additional comonomer or additional compound for controlling the density of the polymer or the like . Preferably, the ethylene / alpha-olefin copolymer produced according to the process can have a density of 0.900 to 0.960 g / cc or less.

Meanwhile, the process for producing a polyolefin according to the present invention may be carried out in addition to the above-mentioned steps, further including steps which can be carried out conventionally in the art before or after the above step.

Hereinafter, the present invention will be described in more detail with reference to Examples.

Manufacturing example  One: Ligand  Compound manufacturing

Triethylaluminum (63.1 mmol) was dissolved in toluene (60 mL), and 2,6-dimethylmorpholine (15.8 mmol) was further added thereto under an inert atmosphere (nitrogen) Lt; / RTI > Next, toluene and unreacted triethyl aluminum were removed by vacuum distillation (0.3 mmHg, 70 DEG C) to prepare a ligand compound represented by the following formula (6).

[Chemical Formula 6]

Manufacturing example  2: Preparation of the first transition metal catalyst

(Nitrogen) using chromium (III) 2-ethylhexanoate (21.3 mmol), 2,6-dimethylmorpholine (63.8 mmol), ethylaluminum dichloride (85.1 mmol) and triethylaluminum (319 mmol) A representative catalyst system was prepared. Specifically, chromium (III) 2-ethylhexanoate was dissolved in 30 mL anhydrous toluene and the ligand was added. Ethyl aluminum dichloride and triethyl aluminum were mixed together in a separate vessel. The aluminum alkyl solution was then slowly poured into the chromium / ligand solution. The reaction solution was stirred for 5 minutes and then the solvent was removed under vacuum. The remaining oily liquid was diluted with cyclohexane to 150 mL and the solution was filtered to remove the black precipitate from the filtrate containing the catalyst system and diluted with toluene to a volume of 250 mL to prepare the first transition metal catalyst.

Preparation Example 3: Preparation of the first transition metal catalyst

Except that the bis (2-ethylhexanoate) chromium (III) hydroxide was used in place of the chromium (III) 2-ethylhexanoate in Production Example 2, a first transition metal catalyst .

Preparation Example 4: Preparation of a first transition metal catalyst

A first transition metal catalyst was prepared in the same manner as in Preparation Example 2, except that the ligand compound prepared in Preparation Example 2 was used instead of 2,6-dimethylmorpholine.

Preparation Example 5: Preparation of the first transition metal catalyst

Except that bis (2-ethylhexanoate) chromium (III) hydroxide was used in place of chromium (III) 2-ethylhexanoate in Production Example 2, and, instead of 2,6-dimethylmorpholine, A first transition metal catalyst was prepared in the same manner as in Production Example 2, except that the ligand compound was used.

Example  And Comparative Example : Preparation of Polyethylene by Tandem Reaction

The first transition metal catalyst was prepared by stirring in a glove box in a Schlenk vessel with 10 mL of toluene for 5 minutes. The polymerization characteristics for the tandem catalyst system comprising the second transition metal catalyst were evaluated by the following method. At this time, the content of the first transition metal catalyst (component (A)), the content of the second transition metal catalyst (component (B)), the content of the promoter compound (component (C) And the melting point and density of the resulting polymer are shown in Table 1, respectively.

A 2L high pressure reactor was used for the polymerization. After completely replacing the reactor with nitrogen, 1 L of cyclohexane and 1 mL of triethylaluminum were added to Scavenger, and then ethylene was charged at 10 bar, and the temperature was maintained at 90 ° C. Then, the mixture was stirred at a speed of 500 rpm. A predetermined amount of the first transition metal catalyst and the second transition metal catalyst were fed into the reactor through a separate catalyst inlet vessel. The pressure of the reactor was kept constant by the ethylene introduced into the reactor, and the polymerization reaction proceeded for 1 hour. When the polymerization reaction was completed, the supply of ethylene was stopped, the reactor temperature was cooled to 20 DEG C, and unreacted ethylene was vented to the outside of the reactor. The activity of the remaining catalyst, alkyl aluminum and methylaluminoxane, was deactivated by the addition of 20 mL of acidified ethanol. Then, the reaction product was filtered to remove unreacted alpha-olefin monomer, and then dried in a vacuum oven at 80 DEG C to obtain polyethylene.

Example  One

As the first transition metal catalyst, a first transition metal catalyst prepared according to Preparation Example 2 was used, and as a second transition metal catalyst, bis (indenyl) zirconium dichloride was used.

Example  2

As the first transition metal catalyst, a first transition metal catalyst prepared according to Preparation Example 3 was used and bis (indenyl) zirconium dichloride was used as a second transition metal catalyst.

Example  3

A first transition metal catalyst was used as the first transition metal catalyst and bis (indenyl) zirconium dichloride was used as the second transition metal catalyst.

Example  4

As the first transition metal catalyst, a first transition metal catalyst prepared according to Preparation Example 5 was used, and as a second transition metal catalyst, bis (indenyl) zirconium dichloride was used.

Example  5

The first transition metal catalyst was a first transition metal catalyst prepared according to Preparation Example 5, and the second transition metal catalyst was bis (indenyl) zirconium dichloride supported thereon. The method for preparing the supported catalyst is as follows. In a glove box, 135 μmol of bis (indenyl) zirconium dichloride and 1.0 g of Silica were placed in a 250 mL RBf (round bottom flask), taken out of the glove box, 10 mL of toluene was added to the catalyst compound, , MAO (8 mL) was slowly added to the catalyst compound solution at room temperature and then stirred for 1 hour. 10 mL of toluene was added to silica, the temperature of the silica in the slurry state was lowered to 0 ° C, and the mixed reaction solution of the catalyst and MAO was added slowly. After stirring for 1 hour, the temperature was raised to 70 ° C and the reaction was further continued for 6 hours. After the completion of the reaction, stirring was stopped, and the toluene layer was separated and removed. Then, the solution was washed with n-hexane, and then vacuum was applied to remove all of the toluene to obtain a supported catalyst of free flowing powder (Free Flowing Powder) .

Example  6

As the first transition metal catalyst, the first transition metal catalyst prepared according to Preparation Example 5 was used, and as the second transition metal catalyst, ethylene bis (indenyl) zirconium dichloride was used.

Comparative Example  One

Example 1 was repeated except that TaCl ₅ disclosed in U.S. Patent No. 6344594 was used as an ethylene oligomerization catalyst instead of the first transition metal catalyst and the ethylene partial pressure was adjusted to 9.0 bar Polyethylene was prepared in the same manner.

Comparative Example  2

Polyethylene was prepared in the same manner as in Example 4 except that the first transition metal catalyst was not added.

Comparative Example  3

Polyethylene was prepared in the same manner as in Example 6 except that the first transition metal catalyst was not added.

Comparative Example  4

Polyethylene was prepared in the same manner as in Example 4, except that 10 mL of 1-hexene was added instead of adding the first transition metal catalyst.

As can be seen from the above Table 1, polyethylene having a density of 0.942 g / cm 3 or less was obtained in the case of alpha-olefin and ethylene copolymer (Examples 1 to 6) polymerized in the presence of the tandem catalyst system according to the present invention And the density of the polyethylene copolymer was lowered to 0.910 g / cm 3 according to the oligomerization activity and conversion of the first transition metal catalyst. That is, compared with the case of using a separate comonomer (Comparative Example 4), a polyethylene copolymer having a density lower than that obtained by adding 1-hexene was efficiently obtained without using a comonomer, -Hexene together with hexene are optionally made together and provided as alpha-olefins.

On the contrary, in the case of polymerizing by applying the previous catalyst system (Comparative Example 1), the density is higher than that of the copolymer according to the examples. In order to lower the density, the amount of the catalyst is increased or the use of additional comonomer I can confirm that it is required.

The preferred embodiments of the present invention have been described in detail above. It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Accordingly, the scope of the present invention is defined by the appended claims rather than the foregoing detailed description, and all changes or modifications derived from the meaning, range, and equivalence of the claims are included in the scope of the present invention Should be interpreted.

Claims (18)

(A) a first transition metal catalyst for olefin oligomerization comprising a ligand compound, a chromium compound and a metal alkyl compound represented by the following general formula (1) or (2);
[Chemical Formula 1]

(2)

Wherein E1 and E2 are each independently nitrogen (N), oxygen (O), phosphorus (P) or sulfur (S) elements, B1 is aluminum (Al) or boron (B) R 1 to R 6 are each independently hydrogen or an alkyl (Alky) group having 1 to 20 carbon atoms.
(B) a second transition metal catalyst capable of polymerizing ethylene and an alpha olefin; And
(C) a cocatalyst for activating the first transition metal catalyst and the second transition metal catalyst;
≪ / RTI > The method according to claim 1,
Wherein the first transition metal catalyst (A) is used in a reaction for synthesizing an alpha-olefin from ethylene. The method according to claim 1,
Wherein the chromium compound is chromium (III) or chromium (II) containing compound. The method according to claim 1,
Wherein the metal alkyl compound is at least one selected from the group consisting of an alkyl aluminum compound, an alkyl boron compound, an alkyl magnesium compound, an alkyl zinc compound, and an alkyl lithium compound. 5. The method of claim 4,
The alkyl aluminum compound is preferably selected from the group consisting of triethylaluminum, tripropylaluminum, tributylaluminum, diethylaluminum chloride, diethylaluminum bromide, diethylaluminum ethoxide, diethylaluminum phenoxide, ethylaluminum dichloride and ethylaluminum sesquichloride Wherein the catalyst composition is at least one selected from the group consisting of: The method according to claim 1,
Wherein the molar ratio of the ligand compound, the chromium compound, and the metal alkyl compound is 0.5: 1: 1 to 5: 1: 3,000 based on the chromium compound. The method according to claim 1,
Wherein the alpha olefin is 1-hexene or 1-octene. The method according to claim 1,
Wherein the second transition metal catalyst (B) is at least one selected from the group consisting of a Ziegler-Natta catalyst, a chromium catalyst, a metallocene catalyst, and a constrained geometry catalyst. The method according to claim 1,
Wherein the cocatalyst (C) is at least one selected from the group consisting of compounds represented by the following Chemical Formulas (3) to (5).
(3)

(Wherein R ³ is an alkyl group having 1 to 10 carbon atoms and n is an integer of 1 to 70)
[Chemical Formula 4]

(Wherein R ⁴ , R ⁵ and R ⁶ are each independently an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms or a halogen group, and R ⁴ , R ⁵ and R ⁶ Is an alkyl group having from 1 to 10 carbon atoms.
[Chemical Formula 5]
[CD]
Wherein C is a metal or a nonmetal compound having a proton-binding cations or oxidation potential of Lewis Base, D is a compound of an element belonging to Groups 5 to 15 on the periodic table, to be.) 10. The method of claim 9,
The compound of Formula 3 may be selected from the group consisting of Methylaluminoxane, Ethylaluminoxane, Butylaluminoxane, Hexylaluminoxane, Octylaluminoxane, and Decylaluminoxane. Lt; RTI ID = 0.0 > 1, < / RTI > 10. The method of claim 9,
The compound of Chemical Formula 4 may be used in combination with one or more compounds selected from the group consisting of trimethylaluminum, triethylaluminum, tributylaluminum, trihexylaluminum, trioctylaluminum, tridecylaluminum, But are not limited to, dimethylaluminum methoxide, diethylaluminum methoxide, dibutylaluminum methoxide, dimethylaluminum chloride, diethylaluminum chloride, dibutylaluminum chloride ), Methylaluminum dimethoxide, ethylaluminum dimethoxide, butylaluminum dimethoxide, methylaluminum dichloride, ethyl aluminum dichloride (Et wherein the catalyst composition is at least one compound selected from the group consisting of dibutyltin dichloride, dibutyltin dichloride and butylaluminum dichloride. 10. The method of claim 9,
The compound of Chemical Formula 5 may be at least one selected from the group consisting of trimethylammonium tetraphenylborate, triethylammonium tetraphenylborate, tripropylammonium tetraphenylborate, tributylammonium tetraphenylborate, trimethylammonium tetraphenylborate, (Pentafluorophenyl) borate, triethylammonium tetrakis (pentafluorophenyl) borate, tripropylammonium tetrakis (pentafluorophenyl) borate, triethylammonium tetrakis ) Pentafluorophenyl borate, triphenyl tetrakis (pentafluorophenyl) borate, tributylammonium tetrakis (pentafluorophenyl) borate, anilinium tetraphenylborate, anilinium tetra Anilinium tetrakis (pentafluorophenyl) borate, pyridinium tetraphenylborate, pyridinium tetrakis (pentafluorophenyl) borate, ferrocenium tetrachloride, (Pentafluorophenyl) borate, Silver tetrakis (pentafluorophenyl) borate, Silver tetrakis (pentafluorophenyl) borate, Silver tetraphenylborate, Silver tetrakis Tris (pentafluorophenyl) borane, Tris (2,3,5,6-tetrafluorophenyl) borane, Tris (2,3) , 4,5-tetraphenylphenyl) borane and tris (3,4,5-trifluorophenyl) borane (Tris (3,4,5) -trifluorophenyl) borane), and more preferably at least one compound selected from the group consisting of Catalyst composition. The method according to claim 1,
The second transition metal catalyst (B) is contained in a molar ratio of 1: 0.001 to 1: 5 based on the transition metal atom contained in each compound with respect to the first transition metal catalyst (A)
Wherein the cocatalyst (C) is contained in a molar ratio of 1: 1 to 1: 10,000 based on the transition metal atom contained in each compound with respect to the (A) first transition metal catalyst. The method according to claim 1,
Further comprising a carrier on which the first transition metal catalyst (A), the second transition metal catalyst (B), and the cocatalyst (C) are supported. 15. The method of claim 14,
The carrier is selected from the group consisting of silica, alumina, magnesium chloride, calcium chloride, bauxite, zeolite, magnesium oxide, zirconium oxide, titanium oxide, boron trioxide, calcium oxide, zinc oxide, barium oxide, By weight based on the total weight of the catalyst composition. A process for the production of polyethylene, comprising polymerizing ethylene in the presence of the catalyst composition according to claim 1. 17. The method of claim 16,
(A) forming an alpha-olefin from ethylene in the presence of a first transition metal catalyst; And
Forming a copolymer of the alpha-olefin and ethylene by feeding the second transition metal catalyst (B) and ethylene to the alpha-olefin formation reaction system;
≪ / RTI > 17. The method of claim 16,
Wherein the polymerized copolymer has a density of 0.960 g / cc or less.