KR20190057542A - Catalyst system for oligomerization of ethylene - Google Patents

Abstract

The present invention relates to preparation of alpha-olefins and, more specifically, to an alpha-olefin catalyst suitable for preparation of alpha-olefins having a novel structure, comprising a transition metal or transition metal precursor, a ligand having a framework represented by chemical formula 1, and a co-catalyst; and to a method of preparing alpha-olefins. In the chemical formula 1 of R^1-S(=O)-Y-S(=O)-R^2: R^1 and R^2 are each independently hydrocarbyl, substituted hydrocarbyl, heterohydrocarbyl, or substituted heterohydrocarbyl, and Y is a group linking S(=O). A catalyst system according to the present invention exhibits excellent activities of the catalyst, and the alpha-olefins with C8″-C18″ occupy a large portion of the distribution of generated alpha-olefins.

Description

Catalyst system for oligomerization of ethylene < RTI ID = 0.0 >

The present invention relates to a catalyst for use in ethylene oligomerization and a method for oligomerizing ethylene using the catalyst, and more particularly, to a catalyst for use in a new oligomerization reaction and a process for producing the same, The present invention relates to a method of reaction.

Conventional ethylene oligomerization techniques include the catalyst technology to produce a variety of alpha olefins with a Schulze-Flory or Poisson distribution-the catalyst technology is called Full Range- and 1-butene Or on-purpose technology for more selective production of 1-hexene or 1-octene, and more recently, 1-hexene or 1-octene has been developed more selectively The catalyst technology to produce has made great progress.

In the case of 1-butene, 1-hexene or 1-octene, applications as comonomers in the production of linear low density polyolefins have been greatly expanded. Various other alpha olefins having a carbon number of 10 or more are widely used as raw materials for producing polyalphaolefins, detergent alcohols, lubricants for oil fields and waxes, . Full-range catalyst technology has a long history, and a representative example is the Ni-based catalyst used in the SHOP processor developed by Shell. In this connection, EP 0,177,999 and US 3,676,523 illustrate a catalyst system comprising a diphenylphosphinoacetic acid ligand and a Ni compound, and US 4,528,416 exemplifies a method of oligomerizing the catalyst in a mono-alcohol or a diol solvent . German Patent No. 1,443,927 and US Patent No. 3,906,053 illustrate a method of oligomerizing ethylene under a high-pressure ethylene pressure using a trialkylaluminum catalyst. A method for oligomerizing ethylene in the presence of a solvent of toluene, cyclohexane, and n-octane in a catalyst system composed of a zirconium alkoxide, an alcohol, and an aluminum compound is illustrated in U.S. Patent No. 6,930,218. However, the above catalysts have a relatively low activity of the catalyst. European Patent No. EP 0,444,505 discloses a processor for producing alpha olefins using Ziegler catalysts. Alpha olefins are produced efficiently but at relatively high pressure ethylene pressures and high temperatures.

In recent years, on-per-pose catalyst technologies have been developed in which ethylene is selectively quaternized to quaternized with 1-hexene or 1-octene by various catalyst techniques, and most of the catalysts are based on chromium-based catalysts. A highly active and highly selective ethylene trimerization catalyst system commercialized by Philips is disclosed in U.S. Patent Nos. 5,198,563, 5,376,612, and EP 0,608,447, wherein chromium 3 is a compound, a pyrrole compound, an aluminum alkyl . In recent years, it has been disclosed that a chromium-based catalyst containing a chelating ligand containing phosphorus and nitrogen heteroatoms produces 1-hexene and 1-octene by selectively trimerizing or quaternizing ethylene (US Pat. No. 7,964,763) Examples of catalysts include (phenyl) ₂ PN (isopropyl) P (phenyl) ₂ . The prior art is limited primarily to the selective production of alpha olefins of 1-hexene or 1-octene with chromium catalysts containing chelate ligands containing heteroatoms, and as the chelating ligands, (R ₁ ) (R ₂ ) PN (R ₅ ) -P (R ₃ ) (R ₄ ) structure. Also, a highly selective quatification catalyst system is disclosed in Korean Patent No. 1,074,202, which is based on a catalyst system consisting of a chromium compound, a -PCCP-skeleton di-phosphine ligand, and a cocatalyst compound.

As can be seen, the development of full range or on-perforated alpha olefin manufacturing technology is based on advances in various catalytic technologies, especially on novel ligand structures, and the diverse needs of alpha olefins for developing various applications have led to improved catalysts Need

More particularly, the present invention relates to a novel transition metal or transition metal precursor suitable for the production of alpha olefins, a ligand having a skeletal structure represented by the following formula (1), an alpha olefin catalyst comprising a cocatalyst And a process for producing an alpha-olefin.

[Chemical Formula 1]

R ¹ -S (= O) -YS (= O) -R ²

Wherein R ¹ and R ² are independently hydrocarbyl, substituted hydrocarbyl, heterohydrocarbyl, or substituted heterohydrocarbyl, and Y is a group connecting S (= O).

The ethylene oligomerization catalyst system according to the invention is made, including the transition metal or transition metal ^{precursor, R 1 -S (= O)} -YS (= O) -R 2 skeleton structure ligand and co-catalyst, wherein R ¹ -S (= O) -YS (= O) -R ² skeleton ligands are represented by the following formula (1).

[Chemical Formula 1]

R ¹ -S (= O) -YS (= O) -R ²

Wherein R ¹ and R ² are the same or different and each independently represents a substituted or unsubstituted C1-C20 alkyl group adjacent to S (= O); A substituted or unsubstituted C6-C20 aryl group; And a substituted or unsubstituted C3-C20 heteroaryl group. Y is a group connecting S (= O), a substituted or unsubstituted C1-C20 alkyl group; A substituted or unsubstituted C6-C20 aryl group; And a substituted or unsubstituted C3-C20 heteroaryl group.

Suitable examples of R ¹ and R ² include, independently, phenyl, benzyl, naphthyl, anthraceny, mesityl, xylyl, methyl, ethyl, propyl, isoproyl, butyl, isobutyl, tert.butyl, cyclohexyl, 4-methylpentyl, 4-methylpentyl, 4-methylcyclohexyl, 4-ethylcyclohexyl, 4-isopropylcyclohexyl, tolyl, xylyl, Wherein the alkyl moiety is selected from the group consisting of methyl, ethyl, propyl, isopropyl, butyl, isopropyl, n-butyl, , Imidazolyl, pyrazolyl, pyridinyl, pyrimidinyl, pyrazinyl, indolyl, isoindolyl, indolinyl, benzofuryl, benzothienyl, benzimidazolyl, benzthiazolyl, benzoxazolyl, quinolyl Can be selected from the group consisting of gentyl, quinolinyl, isoquinolinyl and quinazolinyl. Preferably R ¹ and R ² are independently selected from the group consisting of methyl, ethyl, propyl, isoproyl, butyl, isobutyl, tertiary butylphenyl, tolyl, biphenyl, naphthyl, cyclohexyl, Phenyl, 4-isopropylphenyl, 4-tertiary-butylphenyl, 4-methoxyphenyl, 4-isopropoxyphenyl. Suitable examples of Y include methylene, 1,2-ethane, 1,2-phenylene, 1,3-propane, 1,4-butane, 1,5-pentane and the like.

An example of the R ¹ -S (= O) -YS (= O) -R ² skeleton ligand according to the present invention includes the following structure: However, the following structural examples are merely examples for illustrating the present invention, and do not limit the protection range of the above-mentioned chemical formula 1 of the present invention.

(2)

R ¹ -S (= O) -CHR ³ -CHR ⁴ -S (= O) -R ²

R ¹ and R ² are the same or different and are selected from the group consisting of a linear C1-C20 alkyl group, a C1-C20 branched alkyl group, a vinyl group, a C1-C20 A straight chain halogenated alkyl group having 1 to 20 carbon atoms, a straight chain halogenated alkyl group having 1 to 20 carbon atoms, a straight chain halogenated alkyl group having 1 to 20 carbon atoms, a straight chain halogenated alkenyl group having 1 to 20 carbon atoms, An alkyl group, a C1-C20 cycloalkenyl group, a C1-C20 halogenated cycloalkyl group, and a C1-C20 halogen substituted cycloalkenyl group; R ³ and R ⁴ are the same or different and each represents a straight chain alkyl group having 1 to 20 carbon atoms, a branched alkyl group having 1 to 20 carbon atoms, a vinyl group, a straight chain alkenyl group or a branched alkenyl group having 1 to 20 carbon atoms, Substituted or unsubstituted C1-C20 branched alkyl group, a C1-C20 branched halogen substituted alkyl group, a C1-C20 linear halogen substituted alkenyl group or a branched halogen substituted alkenyl group, a C1-C20 cycloalkyl group, a C1-C20 cycloalkenyl group, An alkyl group, or a halogen-substituted cycloalkenyl group having 1 to 20 carbon atoms.

A specific example is a 1,2-bissulfinylbenzene compound. Examples of the 1,2-bissulfinylbenzene compound include 1,2-bis (methylsulfinyl) benzene, 1,2-bis (ethylsulfinyl) benzene, Bis (isobutylsulfinyl) benzene, 1,2-bis (isopropylsulfinyl) benzene, 1,2-bis ) Benzene, 1,2-bis [(2-methylbutyl) sulfinyl] benzene, 1,2-bis [ Bis [(2-methylhexyl) sulfinyl] benzene, 1,2-bis (n-hexylpentylsulfinyl) benzene, 1,2- Benzene, bis [(2-ethylpentyl) sulfinyl]] benzene, 1,2-bis (isoheptylsulfinyl) benzene, 1,2- (2-methylheptyl) sulfinyl) benzene, 1,2-bis (isooctylsulfinyl) benzene, 1,2-bis [ )] Benzene, 1,2-bis (neoctylsulfinyl) benzene, 1,2-bis (n-nonylsulfinyl) Benzene, 1,2-bis (isononylsulfinyl) benzene, 1,2-bis (nonadecylsulfinyl) benzene, 1,2- ) Benzene, 1,2-bis (methylsulphinyl) ethane, 1,2-bis (ethylsulphinyl) ethane, 1,2- ) Ethane, 1,2-bis (phenylsulfinyl) ethane, 1,2-bis (methylsulfinyl) -1,2-dimethylethane, 1,2- Bis (isopropylsulfinyl) -1,2-dimethylethane, 1,2-bis (phenylsulfinyl) -1,2-dimethylethane, 1,2- Methylsulfinyl-2-ethylsuccinyl ethane, 1-methylsulfinyl-2-ethylsuccinyl ethane, 1- Methylsulfinyl-2-phenylsupinyl ethane and the like.

The transition metal or transition metal precursor according to the present invention is selected from the group consisting of Group 3 to Group 10 elements on the periodic table. It is preferably chromium. The transition metal or transition metal precursor of the ethylene oligomerization catalyst according to the present invention may be a simple inorganic or organic salt, coordination or organometallic complex, preferably a chromium or chromium precursor, and the chromium or chromium precursor may be chromium (III) acetylacetonate, chromium trichlorotris tetrafluoride and chromium (III) 2-ethylhexanoate.

The catalyst system according to the present invention can be prepared through the steps of producing a ligand coordination complex (catalyst precursor) from a ligand of the transition metal compound and the above-mentioned R ¹ -S (═O) -YS (═O) -R ² skeleton , A coordination complex prepared by using a ligand of the R ¹ -S (═O) -YS (═O) -R ² skeleton and a transition metal or transition metal precursor is added to the reaction mixture, or R ¹ -S = O) -Y (= O) -R ² skeleton structure and a transition metal or transition metal precursor are separately added to the reactor to form an R ¹ -S (═O) -YS (═O) -R ² skeleton Of ligand coordination complexes can be produced. The formation of a ligand coordination complex of the R ¹ -S (═O) -YS (═O) -R ² skeleton means that the complex is formed in the medium in which the catalytic reaction takes place so that the coordination complex is formed in situ The transition metal or transition metal precursor and the transition metal precursor are so selected that the ratio of metal to ligand is typically about 0.01: 1 to 100: 1, preferably about 0.1: 1 to 10: 1, more preferably 0.5: Mix the ligands of the R ¹ -S (= O) -YS (= O) -R ² skeleton.

The cocatalyst according to the present invention may be any compound that produces an active catalyst upon mixing with a transition metal or transition metal precursor and R ¹ -S (= O) -YS (= O) -R ² skeleton ligands .

The cocatalyst can be a single compound or a mixture thereof, and examples thereof include an organoaluminum compound, an organic boron compound, an oil, an inorganic acid, and a salt. The organoaluminum compound includes compounds such as LiAlH ₄ and compounds of the formula AlR ₃ , wherein each R is independently C ₁ -C ₁₂ alkyl, oxygen containing alkyl or halide. Examples include trimethyl aluminum, triethyl aluminum, triisobutyl aluminum, tri-n-octyl aluminum, methyl aluminum dichloride, methyl aluminum dichloride, ethyl aluminum dichloride, dimethyl aluminum chloride, diethyl aluminum chloride, , Methyl aluminum sesquichloride, and aluminoxane. Aluminoxane is well known in the art as a typical oligomeric compound that can be prepared by the addition reaction of an alkyl aluminum compound, such as trimethyl aluminum and water. Such oligomeric compounds may be linear, cyclic, cage or mixtures thereof. Commercially available aluminoxanes are generally believed to be mixtures of linear and cyclic compounds. Nonlimiting examples thereof include, but are not limited to, methylaluminoxane, ethylaluminoxane, isobutylaluminoxane, hexylaluminoxane, octylaluminoxane, decylaluminoxane, or A mixture thereof and the like may be used.

Examples of the organic boron compound include borosilicate, NaBH4, trimethylboron, triethylboron, dimethylphenylammoniumtetra (phenyl) borate, trityltetra (phenyl) borate, triphenylboron, dimethylphenylammoniumtetra (pentafluorophenyl ) Borate, sodium tetrakis [(bis-3,5-trifluoromethyl) phenyl] borate, [(bis-3,5-trifluoromethyl) phenyl] borate, trityltetra (pentafluorophenyl) And tri (tetrafluorophenyl) borate, trimethylammonium tetraphenylborate, triethylammonium tetraphenylborate, tripropylammonium tetraphenylborate, tributylammonium tetraphenylborate, trimethylammonium tetrakis (pentafluorophenyl) borate, tri Ethyl ammonium tetrakis (pentafluorophenyl) borate, tripropylammonium tetrakis (pentafluorophenyl) borate, tributylammonium (Pentafluorophenyl) borate, anilinium tetraphenylborate, anilinium tetrakis (pentafluorophenyl) borate, pyridinium tetraphenylborate, pyridinium tetrakis (pentafluorophenyl) borate, ferrocenium tetrakis (Pentafluorophenyl) borate, tris (2,3,5,6-tetrafluorophenyl) borate, silver tetraphenylborate, silver tetrakis (pentafluorophenyl) Phosphorus, tris (2,3,4,5-tetraphenyl) borane, and tris (3,4,5-trifluorophenyl) borane.

These organoboron compounds may be used in a form mixed with the organoaluminum compound.

The present invention relates to a catalyst system having a novel structure for providing an ethylene oligomer produced by ethylene oligomerization, a method for producing the same, a catalyst system comprising the transition metal compound having a simple catalytic process and excellent catalytic activity during ethylene oligomerization, A production method thereof, and an ethylene oligomerization method using the above catalyst system.

[Ethylene oligomerization method]

The present invention provides a process for preparing an ethylene oligomer by introducing the catalyst for the production of the ethylene oligomer into an oligomerization reaction.

In order to exhibit higher catalytic activity of the catalyst system of the present invention in performing the ethylene oligomer reaction, a suitable reaction solvent is used, and components necessary for constituting the catalyst system, that is, the main catalyst, cocatalyst and other additive compounds are selected It is preferable to use it in a range of composition ratios under the reaction conditions. In this case, the trimerization reaction can be carried out in slurry, liquid, gaseous and massive form, and a reaction solvent can be used as a medium when a reaction is carried out in a slurry phase or a liquid phase. As a preferred example of the above-mentioned production method, an ethylene oligomer can be prepared by introducing the aforementioned catalyst for an ethylene oligomer (for example, a main catalyst, a cocatalyst), ethylene and a solvent into the reactor to convert ethylene into ethylene oligomer.

In the preparation of the catalyst used in the present invention, the amount of cocatalyst to be used is generally from 0.1 to 20,000, preferably from 1 to 4,000, aluminum or boron atoms per chromium atom. If the concentration of each component is out of the above range, the catalytic activity is too low, and undesirable side reactions such as polymer formation occur.

The catalyst system used in the present invention can be prepared by reacting a transition metal or transition metal precursor R ¹ -S (= O) -YS (= O) -R ² skeleton ligand and cocatalyst simultaneously or in any order, Can be added together in the presence or absence of monomers to obtain a catalyst that is active. For example, the transition metal precursor, the R ¹ -S (= O) -YS (= O) -R ² skeleton ligand, the cocatalyst and the monomer can be contacted together at the same time or the component transition metal precursor R ¹ -S (═O) -Y (═O) -R ² skeleton ligand and cocatalyst can be added together either sequentially or sequentially in any order and then contacted with the monomer, or the component transition metal precursor, R ¹ -S = O) -Y (= O) -R ² skeleton ligand may be added together to form a separable metal-ligand complex and then added to the co-catalyst and contacted with the monomer, or the transition metal precursor, R ¹ -S (= O) -Y (= O) -R ² skeleton ligand and cocatalyst together to form a separable metal-ligand complex and then contact with the monomer. Solvents suitable for contacting the catalyst or catalyst system components include hydrocarbon solvents such as heptane, toluene, 1-hexene and the like and polar solvents such as diethyl ether, tetrahydrofuran, acetonitrile, dichloromethane, chloroform, chlorobenzene, methanol , Acetone, and the like.

The reaction conditions for oligomerizing ethylene in the presence of the catalyst of the present invention are not particularly limited. For example, the reaction temperature is 0 to 200 ° C, preferably 20 to 100 ° C, the reaction pressure is 1 to 100 bar, It is 70 bar. The reaction duration may vary depending on the activity of the catalyst system, but the reaction can be effectively completed by applying the reaction time in the range of 5 minutes to 3 hours.

Hereinafter, embodiments of the present invention will be described in more detail. It should be understood, however, that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. And changes are possible.

[Materials and Analytical Instruments]

All the synthesis reactions described below were carried out under an inert atmosphere such as nitrogen or argon, and standard Schlenk technique and glove box technique were used.

A solvent for synthesis such as tetrahydrofuran (THF), n-hexane, n-pentane, diethyl ether and methylene chloride (CH ₂ Cl ₂ ) Solvent was passed through an activated alumina column to remove water and used in storage on activated molecular sieve.

Agilent Technologies 7890A GC was used for the analysis of gas chromatography. The analysis conditions were Carrier gas N ₂ , Carrier gas flow (2.0 mL / min) Split ratio (20/1), Initial oven temperature (50 ° C), Initial time (2 min), Ramp (10 ° C / min), Final temperature ) (280 DEG C). The column used was HP-5 and quantified using ethanol or nonane as internal standard.

[Example]

(Tetrahedron Lett., 1993. 34. 2975-2978.), 2,3-bis (tertiarybutylsulfinyl) butane (Phosphorus, Sulfur Silicon Relat. 180. 1509-1510.) Were synthesized by the process shown in the literature. 1,2-Bis (phenylsulfinyl) ethane (CAS: 6099-21-4) was purchased from a TCI chemical company. Methylaluminoxane (MAO), 10% w / w toluene solution in Albemarle, and other reagents such as trityl (tetrafluorophenyl) borate and triethylaluminum were purchased from Aldrich Chemical Company Aldrich chemical company, Alfa chemical company, Strem chemical company, or TCI chemical company.

Example 1

A 300 ml stainless steel reactor was purged with nitrogen and vacuum, 50 ml of toluene was added, 10.0 mmol-Al of methylaluminoxane (MAO) was added, and the temperature was raised to 65 占 폚.

CrCl ₃ (THF) ₃ (0.02 mmol) and 1,2-bis (phenylsulfinyl) ethane (0.02 mmol) were introduced into a Schlenk flask, 10 ml of methylene chloride was added and the solution was stirred for 4 hours. The solvent was then removed under reduced pressure and the resulting solid was suspended in 20 ml toluene. The toluene solution corresponding to 0.01 mmol was taken and injected into the reactor.

The pressure reactor was charged with 32 bar of ethylene and stirred at a stirring speed of 600 rpm. After 30 minutes, the ethylene feed to the reactor was stopped, the stirring was stopped to stop the reaction and the reactor was cooled to below 10 ° C. Unreacted ethylene in the reactor was discharged, and then ethanol containing 10 vol% hydrochloric acid was injected into the liquid contained in the reactor. A small amount of organic layer sample was passed over anhydrous magnesium sulfate, dried and analyzed by GC-FID. The remaining organic layer was filtered to separate the solid wax / polymer product. These solid products were dried overnight in a 100 < 0 > C oven, then the polymer was obtained and weighed. The oligomer distribution of the reaction mixture obtained by GC analysis is summarized in Table 1

Example 2

The procedure of Example 1 was repeated except that 1,2-bis (methylsulfinyl) benzene (0.02 mmol) was used instead of 1,2-bis (phenylsulfinyl) The results and the weight of the polymer are summarized in Table 1.

Example 3

Except that 2,3-bis (tertiarybutylsulfinyl) butane (0.02 mmol) was used in place of 1,2-bis (phenylsulfinyl) ethane, and the procedure of Example 1 was repeated except that GC The results of the analysis and the weight of the polymer are summarized in Table 1.

Comparative Example 1

Zirconium tetrachloride (ZrCl4) (2.5 mmol) was poured into a Schlenk flask, and 50 ml toluene was added. Triethyl aluminum solution (3.9 mmol) was added while stirring, and the mixture was stirred for 30 minutes. Ethylaluminum sesquichloride solution (13.6 mmol) was injected for 30 minutes. Thereafter, the temperature was raised to 70 캜 and reacted for 1 hour. The temperature was lowered to room temperature, and the entire solution was used as a catalyst stock solution. The toluene solution corresponding to 0.03 mmol was injected into the reactor and the oligomerization reaction was carried out as in Comparative Example 1. The oligomer distribution of the reaction mixture obtained by GC analysis is summarized in Table 1.

Comparative Example 2

Zirconium tetrachloride (ZrCl4) (0.03 mmol) was injected into a Schlenk flask, and 5 ml toluene was added and n-butanol (0.12 mmol) was added while stirring. Thereafter, the temperature was raised to 50 캜 and reacted for 30 minutes. Ethylaluminum sesquichloride solution (0.12 mmol) was slowly added thereto and stirred for 15 minutes. The temperature was lowered to room temperature, and the entire solution was injected into the reactor. The oligomerization reaction was carried out as in Comparative Example 1, and the oligomer distribution of the reaction mixture obtained by GC analysis is summarized in Table 1.

Comparative Example 3

After dissolving tris (2-ethylhexanoate) chromium (Cr (EH) 3) (0.03 mmol) in toluene (3 mL), 2,5-dimethylpyrrole (0.09 mmol) Respectively. A solution of triethylaluminum (0.33 mmol) and diethylaluminum chloride (0.24 mmol) was slowly added thereto and reacted for 1 hour. The total solution was injected into the reactor, and the oligomerization reaction proceeded as in Comparative Example 1. The oligomer distribution of the reaction mixture obtained by GC analysis is summarized in Table 1.

Comparative Example 4

After dissolving tris (2-ethylhexanoate) chromium (Cr (EH) 3) (0.03 mmol) in toluene (3 mL), 2,5-dimethylpyrrole (0.09 mmol) Respectively. Ethylaluminum sesquichloride solution (0.60 mmol) was slowly added thereto and reacted for 1 hour. The total solution was injected into the reactor, and the oligomerization reaction proceeded as in Comparative Example 1. The oligomer distribution of the reaction mixture obtained by GC analysis is summarized in Table 1.

As shown in Table 1, the oligomerization catalyst according to the present invention exhibits high catalytic activity, as can be seen from the oligomerization reaction of the present invention. C8 " (C8 olefin) and C10 " -18 " olefins are very high in the distribution of oligomers and are very useful catalysts for C8 " -C18 " alpha olefins.

Claims (6)

A transition metal or transition metal precursor, a ligand having a skeletal structure represented by the following formula (1), and a cocatalyst:
[Chemical Formula 1]
R ¹ -S (= O) -YS (= O) -R ²
Wherein R ¹ and R ² are independently hydrocarbyl, substituted hydrocarbyl, heterohydrocarbyl, or substituted heterohydrocarbyl, and Y is a group connecting S (= O). The ethylene oligomerization catalyst system according to claim 1, comprising a transition metal or transition metal precursor, a ligand having a skeletal structure represented by the following formula (2), and a cocatalyst:
(2)
R ¹ -S (= O) -CHR ³ -CHR ⁴ -S (= O) -R ²
Wherein R ¹ and R ² are the same or different and each represents a straight chain alkyl group having 1 to 20 carbon atoms, a branched alkyl group having 1 to 20 carbon atoms, a vinyl group, a straight chain alkenyl group or a branched alkenyl group having 1 to 20 carbon atoms, C20 halogenated alkyl group, a C1-C20 straight chain halogenated alkenyl group or a branched halogenated alkenyl group, a C1-C20 cycloalkyl group, a C1-C20 cycloalkenyl group, a C1-C20 halogen A substituted cycloalkyl group, or a compound having a halogen-substituted cycloalkenyl group of a C1-C20; R ³ and R ⁴ are the same or different and each represents a straight chain alkyl group having 1 to 20 carbon atoms, a branched alkyl group having 1 to 20 carbon atoms, a vinyl group, a straight chain alkenyl group or a branched alkenyl group having 1 to 20 carbon atoms, Substituted or unsubstituted C1-C20 branched alkyl group, a C1-C20 branched halogen substituted alkyl group, a C1-C20 linear halogen substituted alkenyl group or a branched halogen substituted alkenyl group, a C1-C20 cycloalkyl group, a C1-C20 cycloalkenyl group, An alkyl group, or a halogen-substituted cycloalkenyl group having 1 to 20 carbon atoms. The ethylene oligomerization catalyst system according to claim 1 or 2, wherein the transition metal or transition metal precursor is chromium or chromium precursor. 4. The process of claim 3, wherein the chromium or chromium precursor is selected from the group consisting of chromium (III) acetylacetonate, chromium trichlorotris tetrafluoride, and chromium (III) 2-ethylhexanoate. Oligomerization catalyst system. The ethylene oligomerization catalyst system according to claim 1 or 2, wherein the promoter is methylaluminoxane (MAO), ethylaluminoxane (EAO), or isobutylaluminoxane (IBAO). 3. The ethylene oligomerization catalyst system according to claim 1 or 2, wherein the promoter is a combination of trialkyl aluminum and the following borate or boron compound:
(Phenyl) borate, trimethyltetra (phenyl) borate, triphenylboron, dimethylphenylammoniumtetra (pentafluorophenyl) borate, sodium tetrakis [(bis-3,5-trifluoromethyl) phenyl ] Borate, H + (0Et2) 2 [(bis-3,5-trifluoromethyl) phenyl] borate, trityltetra (pentafluorophenyl) borate and tris (pentafluorophenyl) boron, trimethylammonium tetraphenylborate , Triethylammonium tetraphenylborate, tripropylammonium tetraphenylborate, tributylammonium tetraphenylborate, trimethylammonium tetrakis (pentafluorophenyl) borate, triethylammonium tetrakis (pentafluorophenyl) borate, tripropylammonium Tetrakis (pentafluorophenyl) borate, tributylammonium tetrakis (pentafluorophenyl) borate, anilinium tetraphenylborate, (Pentafluorophenyl) borate, pyridinium tetraphenylborate, pyridinium tetrakis (pentafluorophenyl) borate, ferrocenium tetrakis (pentafluorophenyl) borate, silver tetraphenyl borate, silver tetrakis (Pentafluorophenyl) borate, tris (pentafluorophenyl) borane, tris (2,3,5,6-tetrafluorophenyl) borane, tris (2,3,4,5-tetraphenylphenyl) Borane, tris (3,4,5-trifluorophenyl) borane.