KR101277295B1

KR101277295B1 - Novel compound, catalyst composition comprising the same and a process of preparing for polyethylene using the same

Info

Publication number: KR101277295B1
Application number: KR1020110081241A
Authority: KR
Inventors: 이용호; 이기수; 권헌용; 조민석; 전만성; 송은경; 홍대식
Original assignee: 주식회사 엘지화학
Priority date: 2010-08-17
Filing date: 2011-08-16
Publication date: 2013-07-04
Also published as: KR20120048468A

Abstract

The present invention relates to a novel compound, a catalyst composition comprising the same, and a method for preparing a linear low-density polyethylene (LLDPE) using the same, and more particularly, a novel organic chromium compound having a predetermined chemical structure according to the present invention. And a method for producing linear low density polyethylene using a catalyst composition comprising the same.

Description

Novel compound, catalyst composition comprising the same and a process of preparing for polyethylene using the same}

The present invention relates to a novel compound, a catalyst composition comprising the same, and a method for producing polyethylene using the same.

Linear alpha-olefins are widely used commercially as important substances used in comonomers, detergents, lubricants, plasticizers, etc. In particular, 1-hexene and 1-octene are used in the production of linear low density polyethylene (LLDPE). It is often used as a comonomer to control the density.

Conventional production processes of LLDPE (linear low-density polyethylene) include forming alpha-olefins, such as alpha-olefins, for example, by forming branches in the polymer backbone with ethylene to control the density 1-hexene, and 1-octene.

Therefore, in the case of LLDPE having a high comonomer content, there is a problem that the comonomer occupies a large part of the manufacturing cost. Various attempts have been made to solve these problems.

Since alpha-olefins vary in application field or market size depending on the type of olefin, the technology capable of selectively producing a specific olefin is of great commercial significance. Recently, selective ethylene oligomerization has been used to produce 1-hexene or 1 - octene catalysts have been studied extensively.

Conventional commercial manufacturing methods for producing 1-hexene or 1-octene include SHOP process of Shell Chemical and Ziegler Process of Chevron Philips. Lower alpha-olefins can be produced with a wide distribution of C4 to C20.

The present invention can maintain high activity and alpha-olefin selectivity even when used on a carrier, and can produce low density polyethylene in one reactor using only ethylene without using a small amount of comonomer or comonomer. It is to provide a novel organic chromium compound, a supported catalyst and a catalyst composition comprising the same.

In addition, to provide a method for producing polyethylene at a low cost by using the organic chromium compound.

The present invention provides an organochrome compound represented by the following formula (1).

[Formula 1]

Wherein R ₁ and R ₁ ′ are the same or different from each other and are each independently a hydrocarbyl group having 2 to 20 carbon atoms containing a hetero atom selected from the group consisting of O, N and P; R ₂ is hydrogen or a hydrocarbyl group having 2 to 20 carbon atoms containing a hetero atom selected from the group consisting of O, N, and P; Each X is independently halogen, hydrogen, or a hydrocarbyl group having 1 to 4 carbon atoms.

The present invention provides a catalyst composition comprising the organic chromium compound.

The present invention provides a supported catalyst on which the organic chromium compound is supported on a carrier.

In addition, the present invention provides a method for producing polyethylene comprising the step of polymerizing a monomer composition comprising ethylene in the presence of the organochrome compound.

By using the organic chromium compound according to the present invention, it is possible to maintain high catalytic activity and alpha-olefin selectivity even when supported on a carrier. In addition, when mixed and supported with one or more polymerization catalysts on one carrier, alpha-olefins can be produced at the same time of polymerization, so that ethylene can be produced without using a small amount of comonomers or comonomers. It is possible to produce low density polyolefins in one reactor alone.

In addition, in the case of using the organic chromium compound according to the present invention, it has a feature of maintaining high activity and alpha-olefin selectivity even in solution polymerization without using a carrier.

Hereinafter, an olefin copolymer and a preparation method thereof according to a specific embodiment of the present invention will be described.

According to one embodiment of the invention, an organic chromium compound represented by the following Chemical Formula 1 is provided:

[Formula 1]

As is also supported in the examples below, the use of the organochrome compound not only produces an alpha-olefin, such as 1-hexene, but also uses a small amount of comonomer or no comonomer. And a process for producing linear low density polyethylene (LLDPE) with ethylene alone may be provided.

Many existing organic chromium catalysts can produce alpha-olefins such as 1-hexene with high activity and selectivity in the liquid phase reaction using MAO or borate as a cocatalyst. In this case, the activity was extremely reduced.

However, the use of the organic chromium compound not only maintains high catalytic activity and alpha-olefin selectivity even when supported on a carrier such as silica, but also supports hybridization with one or more polymerization catalysts on one carrier. At the same time, alpha-olefins can be prepared, allowing linear low density polyolefins (LLDPEs) to be produced in one reactor without substantially using comonomers.

In addition, in the case of using the organic chromium compound, it is possible to maintain high activity and high alpha-olefin selectivity even in solution polymerization without using a carrier.

In the case of the organic chromium catalyst mentioned in the previous document ( J. Am. Chem. Soc 2003, 125, 5272), it is reported that the higher the solubility in the solvent, the higher the activity. It is believed that not only the solubility of the catalyst was increased by introducing an alkoxy group to the terminal but also the alkoxy group at the end acts as a Lewis basic ether group that can be efficiently supported on Lewis acidic parts such as Si or Al of the carrier. Due to this will be obtained the effect.

R ₁ or R ₁ ′ is a hydrocarbyl group having 2 to 20 carbon atoms including a hetero atom selected from the group consisting of O, N and P, preferably t-butoxy (tertiary) at the end of the alkyl group butoxy) group may be a hydrocarbyl group having 2 to 20 carbon atoms, preferably 4 to 12 carbon atoms to which an alkoxy group is bonded. For example, an alkoxy group such as t-butoxy, iso-butoxy, sec-butoxy, iso-propoxy, n-propoxy, ethoxy, methoxy, etc. may be a hydrocarbyl group having 2 to 20 carbon atoms bonded to the terminal. And most preferably t-butoxy hexyl.

R ₂ is hydrogen or a hydrocarbyl group having 2 to 20 carbon atoms including a hetero atom selected from the group consisting of O, N and P, preferably t-butoxy at the end of hydrogen or an alkyl group It may be a hydrocarbyl group having 2 to 20 carbon atoms, preferably 4 to 12 carbon atoms bonded to an alkoxy group such as a tertiary butoxy group. For example, hydrogen or alkoxy groups such as t-butoxy, iso-butoxy, sec-butoxy, iso-propoxy, n-propoxy, ethoxy, and methoxy have 2 to 20 carbon atoms bonded to the terminals. May be hydrocarbyl, and most preferably hydrogen.

Each X is independently halogen, hydrogen or a hydrocarbyl group having 1 to 4 carbon atoms, preferably Cl or a methyl group, more preferably Cl. Specific examples of the hydrocarbyl group include methyl, ethyl, propyl, isopropyl, t-butyl, iso-butyl, sec-butyl and the like.

In addition, according to another embodiment of the invention, there is provided a catalyst composition comprising the organochromium compound described above.

The catalyst composition may further include one or more cocatalysts selected from the group consisting of compounds represented by Formulas 2 and 3 below, and the compound of Formula 3 may be MAO (methylalumoxane). However, other cocatalysts known to be usable for the polymerization of polyethylene and the like can be used:

[Formula 2]

[LH] ⁺ [ZA ₄ ] ^- or [L] ⁺ [ZA ₄ ] ^-

Wherein L is a neutral or cationic Lewis acid; H is a hydrogen atom; Z is a Group 13 element; Each A is independently aryl having 6 to 20 carbon atoms or alkyl having 1 to 20 carbon atoms, in which at least one hydrogen atom is substituted with halogen, hydrocarbyl having 1 to 20 carbon atoms, alkoxy having 1 to 20 carbon atoms or phenoxy radical;

(3)

-[Al (R8) -O] _n-

In Formula 3, R8 may be the same or different from each other, and each independently halogen; Hydrocarbons having 1 to 20 carbon atoms; Or a hydrocarbon having 1 to 20 carbon atoms substituted with halogen; n is an integer of 2 or more.

The component ratio range of the cocatalyst of Chemical Formula 3 is preferably 50 to 300 mole ratio with respect to the catalyst compound of Chemical Formula 1, and the component ratio range of the promoter of Chemical Formula 2 is 1 to 100 with respect to the catalyst compound of Chemical Formula 1 It is preferred, but not limited to.

In addition, the catalyst composition may further include one or more other polymerization catalysts, and the polymerization catalyst is not particularly limited.

According to another embodiment of the invention, the present invention also provides a supported catalyst carrying an organic chromium compound represented by the formula (1) or a catalyst composition comprising the same on a carrier.

The carrier may be an inert inorganic carrier such as silica or alumina, but is not limited thereto.

The catalyst composition may include one or more other polymerization catalysts, in which case the organic chromium compound and one or more other polymerization catalysts may be mixedly supported on one carrier, and in this case, high activity and high alpha- Olefin selectivity can be maintained.

The supported catalyst may be supported in an amount of 1 wt% to 20 wt% based on the weight of the carrier, but is not limited thereto.

According to another embodiment of the invention, there is provided a process for producing polyethylene comprising the step of polymerizing a monomer composition comprising ethylene in the presence of the organochromium compound described above. In this preparation method, the organochrome compound may be used in the form of a catalyst composition or a supported catalyst as described above. Using this production method, low density polyethylene can be produced effectively.

As described above, the organic chromium compound or the catalyst composition including the same has high activity and high alpha-olefin selectivity, especially 1-hexene, even when used on a carrier, unlike conventional catalysts. Can be maintained. In this case, a carrier used may include silica or alumina, but is not limited thereto.

When preparing polyethylene, when the organochromium compound is mixedly supported on one or more polymerization catalysts and one carrier, alpha-olefins are produced simultaneously with polymerization, so that only a small amount of comonomer is used in one reactor. Alternatively, low density polyethylene can be prepared using only ethylene without using a comonomer. Therefore, in the case of manufacturing linear low density polyethylene (LLDPE) having a high comonomer content, it is possible to reduce the use of comonomers, which occupy a large part of the manufacturing cost, thereby reducing the cost.

In addition, even in the case of solution polymerization without using a carrier in the production of polyethylene, the use of the organic chromium compound or the catalyst composition containing the same results in high activity and high alpha-olefin selectivity, particularly 1-hexene selectivity. Can be maintained.

In the polyethylene production method, the catalyst composition is an aliphatic hydrocarbon solvent having 4 to 12 carbon atoms suitable for an olefin polymerization process, for example, isobutane, pentane, hexane, heptane, nonane, decane, or an isomer thereof and aromatics such as toluene and benzene. It can be injected by dissolving or diluting in a hydrocarbon solvent substituted with a chlorine atom such as a hydrocarbon solvent, dichloromethane or chlorobenzene. The solvent used herein is preferably used by removing a small amount of water or air acting as a catalyst poison by treating with a small amount of scavenger such as alkylaluminum, and may be carried out by further using a promoter.

In the polyethylene production method, the supported catalyst may include a catalyst, for example, the organic chromium compound, in the range of 1% to 20% by weight based on the weight of the carrier.

In the polyethylene production method, the reaction temperature is preferably in the range of 40 ℃ to 150 ℃, but is not limited thereto.

In the polyethylene production method, the reaction pressure is preferably 1 bar to 60 bar, but is not limited thereto.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, these Examples are only for illustrating the present invention and the present invention is not limited thereto.

The structures of the catalysts T1 and T2 used in the comparative examples below and the catalyst T3 used in the examples are as follows.

R ₁ R ₁ R ₂ X T1 Ethyl group Ethyl group Hydrogen Cl T2 Dodecyl Dodecyl Hydrogen Cl T3 t-butoxy hexyl group t-butoxy hexyl group Hydrogen Cl

These catalysts were prepared by the following method:

Production Example 1 Preparation of T3

(1) Preparation of tert-butoxyhexane-1-thiol

1-tert-butoxy-6-chlorohexane 73.2g (0.38mol), thiourea 38g (0.5mol) and 30ml of distilled water were added to a 500ml two-necked flask equipped with a condenser and refluxed at 120 ° C for 5 hours. Lowered to 300ml of a prepared aqueous solution of 30g NaOH was refluxed at 110 ℃ for 14 hours. The reaction was cooled to room temperature, the resulting organic layer was extracted with ether to remove residual water with MgSO _4, and the solvent was removed under reduced pressure to obtain 55.6 g of oily product (6-tert-butoxyhexane-1-thiol, yield 76.9mol%). . The product was confirmed to be purity 97% by GC analysis, and the results of ¹ H-NMR analysis were as follows. ¹ H-NMR (500 MHz) (CDCl 3) δ (ppm): 3.33 (t, 2H), 2.53 (t, 2H), 1.62 (m, 2H), 1.52 (m, 2H), 1.31-1.41 (m, 4H ), 1.18 (s, 9 H)

(2) Preparation of bis (2- (6-tert-butoxyhexylthio) ethyl) amine

NaOH 1g (25mmol) was added to 50ml ethanol solution of bis (2-chloroethyl) amine hydrochloride salt 4.46g (25mmol) at room temperature for 10 minutes, followed by 9.52g (50mmol) of tert-butoxyhexane-1-thiol prepared above. ) And 2 g (50 mmol) of NaOH were added to a 75 ml ethanol solution and stirred at room temperature for overnight. The filtrate obtained by filtering the reactant was dried, dissolved in ether, and the solid which was not dissolved was removed again. The filtrate was dried and the oily product 10.7g (bis (2- (6-tert-butoxyhexylthio) ethyl) amine, yield 95mol%) Obtained. ^The results of the ¹ H-NMR analysis were as follows. ^{1 H-NMR (500MHz) (} CDCl3) δ (ppm): 3.29 (t, 4H), 2.79 (t, 4H), 2.64 (t, 4H), 2.48 (t, 4H), 1.56 (m, 4H), 1.48 (m, 4H), 1.31-1.39 (m, 8H), 1.15 (s, 18H)

(3) Preparation of CrCl ₃ complex of bis (2- (6-tert-butoxyhexylthio) ethyl) amine

0.2 mmol of CrCl ₃ (THF) ₃ and 10 ml of purified THF were added to a Schlenk flask in an argon atmosphere. 0.2 mmol of bis (2- (6-tert-butoxyhexylthio) ethyl) amine prepared above was also prepared as a 10 ml solution of THF purified in a Schlenk flask under argon atmosphere. Each solution was cooled to −5 ° C. and the ligand solution was slowly added to the solution of CrCl ₃ (THF) ₃ using cannula. The color of the solution gradually changed from purple to green and slowly warmed to room temperature and stirred overnight. The solvent was removed under reduced pressure, and the resulting sticky dark green solid was dissolved in 50 ml of purified toluene to prepare CrCl ₃ complex of bis (2- (6-tert-butoxyhexylthio) ethyl) amine.

<Comparative Preparation Examples 1 and 2>: Preparation of T1 and T2

T1 and T2 were prepared in the same manner as in Preparation Example 1, except that ethanethiol and dodecane-1-thiol were used instead of tert-butoxyhexane-1-thiol in Preparation Example 1, respectively.

end. Solution polymerization result of T1 and T3

Comparative Example 1

T1 prepared in Comparative Preparation Example 1 was prepared, and a comparative experiment was conducted.

First, after depressurizing the 500 ml high-pressure reaction vessel under vacuum to make the internal atmosphere inert (Inert) condition with argon gas, 100 ml of purified toluene was added and MAO was added at 300 times the Al / Cr mole ratio compared to the T1 catalyst. Then, toluene solution (5ml, T1 20μmol) of 4mM T1 catalyst was added and the solution reaction was carried out at 90 ° C for 1 hour under the condition of pressurization with 50psig of ethylene, and then the activity was increased through the weight of the reactor with the increased weight of the solution. After the temperature of the reactor was lowered to 0 ° C., a small amount of HCl aqueous solution was added to remove residual MAO and a catalyst, and an organic layer was obtained. The resulting polymer was separated and dried by filtration.

In addition, the organic layer portion was removed with MgSO ₄ to remove residual water, and then the composition of the organic layer was confirmed by GC-MS / MS, and GC area% from which toluene was removed was determined by GC-FID.

The measurement results are shown in Table 2 below.

Example 1

The same process as in Comparative Example 1 was carried out except that New Catalyst T3 obtained in Preparation Example 1 was used instead of T1. The measurement results are shown in Table 2 below.

Example 2

The reaction was carried out in the same manner as in Example 1, except that the reaction temperature was 70 ° C. The measurement results are shown in Table 2 below.

Example 3

The same procedure as in Example 1 was carried out except that 250 ml of solvent toluene was used. The measurement results are shown in Table 2 below.

Example 4

250 ml of solvent toluene was used, and MAO was carried out in the same manner as in Example 1, except that MAO was added at an Al / Cr mole ratio of 600 times that of the T3 catalyst. The measurement results are shown in Table 2 below.

Cr catalyst Solvent-toluene
(ml) MAO
(Al / Cr molar ratio) Temperature
(℃) 1-C6 selectivity (GC area%) C6 selectivity (GC area%) Polyethylene
(%) activation
(g / gCr / hr) Comparative Example 1 T1 100 300 90 98.9 88.4 0.9 2404 Example 1 T3 100 300 90 98.9 82.8 7.7 6154 Example 2 T3 100 300 70 99.3 89.1 4.1 7692 Example 3 T3 250 300 90 99.1 85.2 4.0 9712 Example 4 T3 250 600 90 98.9 83.1 1.6 10288

Polymerization conditions; 20 μmol Cr catalyst, 50 psig ethylene pressure, 60 minutes reaction.

* 1-C6 = selectivity; Proportion of 1-Hexene in C6

* C6 selectivity; Numerical selectivity of isomers such as 1-hexene, 2-hexene, etc.

As shown in Table 2, in the case of using the catalyst according to the embodiment in the production of polyethylene, compared to the case of using the conventional organic chromium compound of the comparative example, high activity appears, high selectivity for 1-hexene It was confirmed that indicates.

I. Polymerization Results of Supported Catalysts of T2 and T3

The process for preparing a supported catalyst was carried out according to a method similar to the method of supporting a metallocene catalyst on a carrier in general, in which MAO was supported as a promoter on a vacuum dehydrated silica at a high temperature and a polymerization catalyst was carried out.

First, 500 ml of the reaction vessel was depressurized in vacuo, and then the internal atmosphere was made inert under argon gas, and 100 ml of purified toluene was filled, followed by vacuum dehydration at 200 ° C. for 2 hours. Was added to the reactor using Schlenk technology. Then 70 ml of 10% MAO toluene solution was added in the same manner. Thereafter, after stirring at 80 rpm at 200 rpm for 12 hours, the temperature was lowered to 40 ℃ to stop the stirring.

After 30 minutes, the toluene filtrate except the sunk silica was removed, followed by addition of 200 ml of toluene and T2 catalyst (T2: 1.0 mmol) toluene dilution solution obtained in Comparative Preparation Example 2, followed by stirring at 200 rpm for 2 hours at 40 ° C., followed by 30 Agitation was stopped for a minute and the filtrate was removed. The slurry left in the reactor was vacuum dried to store the T2 supported catalyst (# B3) in the glove box for future use.

The supported catalysts (# B1 and # B2) of T3 were also prepared in the same manner as above using 0.5 mmol and 1.0 mmol of T3, respectively.

Comparative Example 2

After vacuum drying, 1L of hexane and 1ml of 1M hexane solution of 1M TEAl (triethylaluminum) were added to a 2L high pressure reaction vessel under argon atmosphere, and the reactor temperature was adjusted to 70 ° C.

200 mg of the # B3 supported catalyst prepared above was weighed in a 50 ml glass jar in a glove box, and the slurry containing 40 ml of purified hexane was passed through a cannula to a sample port connected to the reactor. The catalyst slurry was added to the reactor while washing with 0.2 L of hexane. Ethylene 40bar was added to the reactor and ethylene was saturated in the reactor for 1 minute, and then stirred at 500 rpm to proceed with the reaction for 1 hour. After the reaction, stirring was stopped and the reactor was cooled to room temperature, and then the remaining ethylene gas was slowly vented.

The reactor was opened, the polymerization solution was taken, the composition of the organic layer was confirmed by GC-MS / MS, and GC area% obtained by removing hexane as the reaction solution was determined by GC-FID. In addition, the reaction solution was filtered to record the amount of polyethylene produced after drying the solid powder. The measurement results are shown in Table 3 below.

Example 5

The polymerization and analysis were conducted in the same manner as in Comparative Example 2, except that the prepared T3-supported # B1 supported catalyst was used. The measurement results are shown in Table 3 below.

Example 6

The polymerization and analysis were carried out in the same manner as in Comparative Example 2, except that the prepared T3-supported # B2 supported catalyst was used. The measurement results are shown in Table 3 below.

Supported Catalyst Loading
(mmol / g SiO ₂₎ 1-C6 selectivity (GC area%) Total olefins (g) Polyethylene
(%) activation
(g / gCr / hr) Comparative Example 2 # B3 0.10 95.5 1.8 3 3462 Example 5 # B1 0.05 95.0 1.7 4 6538 Example 6 # B2 0.10 91.7 4.9 10 9423

As shown in Table 3, when the organic chromium compound of Example was supported on a carrier (Examples 5 and 6), compared with the case of using the existing organic chromium compound on a carrier (Comparative Example 2) It was confirmed that excellent 1-hexene selectivity was maintained while showing high activity.

All. Polymerization Results of Hybrid Supported Catalysts of T2 and T3

The method for preparing a supported catalyst proceeds similarly to the method of supporting a metallocene catalyst on a carrier, in which MAO is supported as a cocatalyst on vacuum dehydrated silica at high temperature and a polymerization catalyst is generally supported.

First, 500 ml of the reaction vessel was depressurized with vacuum, and then the internal atmosphere was made inert under argon gas, and 100 ml of purified toluene was charged, followed by 10 g of spherical silica having an average particle diameter of 30 μm, vacuum dehydrated at 200 ° C. for 2 hours. It was added to the reactor using Schlenk technology. Then 70 ml of 10% MAO toluene solution was added in the same manner. Thereafter, after stirring at 80 rpm at 200 rpm for 12 hours, the temperature was lowered to 40 ℃ to stop the stirring.

After 30 minutes, remove the toluene filtrate except the sunk silica, and further add 200 ml of toluene and 100 ml of a diluted solution of T2 or T3 catalyst (0.4 mmol) toluene, stir at 200 rpm for 2 hours at 40 ° C, and stop stirring for 30 minutes Was removed. Subsequently, 100 ml of a toluene solution in which 0.5 mmol of the compound (FY5H) having the following structure was dissolved as a catalyst for polymerization was added to the reactor, stirred at 200 rpm for 2 hours at 40 ° C, and stirring was stopped for 30 minutes, and the filtrate was removed. The slurry left in the reactor was vacuum dried to store the hybrid supported catalyst (Y, Z) in the glove box for future use.

FY5H alone supported catalyst (X) degree FY5H It was prepared in the same manner as above using 0.5mmol.

[FY5H]

(tert-Bu-O- (CH ₂ ) 6) MeSi (9-C ₁₃ H ₉ ) ₂ ZrCl ₂

Comparative Example 3

30 mg of the supported catalyst X prepared above was weighed in a 50 ml glass jar in a glove box, and the slurry containing 40 ml of purified hexane was passed to the sample port connected to the reactor using a cannula. The catalyst slurry was added to the reactor while washing with 0.2 L of hexane. Ethylene 40bar was added to the reactor and ethylene was saturated in the reactor for 1 minute, and then stirred at 500 rpm to proceed with the reaction for 1 hour. After the reaction, stirring was stopped and the reactor was cooled to room temperature, and then the remaining ethylene gas was slowly vented.

After opening the reactor, the produced PE resin was filtered and dried, and then further analyzed for physical properties. The measurement results are shown in Table 4 below.

Comparative Example 4

Polymerization and analysis were carried out in the same manner as in Comparative Example 3, except that 20 ml of 1-Hexene was introduced into the reactor before the polymerization. The measurement results are shown in Table 4 below.

Comparative Example 5

T2 and FY5H prepared in the above mixed support The polymerization and analysis were carried out in the same manner as in Comparative Example 3, except that the supported catalyst Y was used. The measurement results are shown in Table 4 below.

Example 7

The polymerization and analysis were carried out in the same manner as in Comparative Example 3, except that the supported catalyst Z having T3 and FY5H hybridized thereon was used. The measurement results are shown in Table 4 below.

Catalyst name and experiment number Supported precursor
Polymerization prescription Activity (kg / g? Hr) DSC 1 H-NMR 1-hexene (ml) Tm (占 폚) 1-hexene
(weight%) Comparative Example 3 X_ # 17 FY5H 0 5.6 133.2 0.10 Comparative Example 5 Y_ # 18 FY5H + T2 0 2.1 131.7 0.55 Example 7 Z_ # 19 FY5H + T3 0 5.9 128.8 1.93 Comparative Example 4 X_ # 21 FY5H 20 5.8 127.0 2.36

As shown in Table 4, when the hybrid supported catalyst of the embodiment is used, it can be seen that low density polyethylene (LLDPE) can be produced using only ethylene.

Claims

An organochrome compound represented by Formula 1 below:
[Formula 1]

Wherein R ₁ and R ₁ ′ are the same as or different from each other, and each independently represent a hydrocarbyl group having 2 to 20 carbon atoms containing an oxygen atom; R ₂ is hydrogen or a hydrocarbyl group having 2 to 20 carbon atoms containing an oxygen atom; Each X is independently halogen, hydrogen, or a hydrocarbyl group having 1 to 4 carbon atoms.

The organochrome compound according to claim 1, wherein R ₁ or R ₁ ′ is a C 2-20 hydrocarbyl group having an alkoxy group bonded to an alkyl group.

The organic chromium compound according to claim 1, wherein R ₂ is hydrogen or a C 2-20 hydrocarbyl group having an alkoxy group bonded to an end of an alkyl group.

The organochrome compound according to claim 1, wherein each X is independently Cl or a methyl group.

The organochrome compound according to claim 1, which is used as a catalyst for polyethylene polymerization.

A supported catalyst carrying the organic chromium compound of claim 1 on a carrier.

The supported catalyst according to claim 6, wherein the carrier is silica or alumina.

The supported catalyst according to claim 6, which is used as a catalyst for polyethylene polymerization.

A catalyst composition comprising the organochrome compound of claim 1.

The catalyst composition according to claim 9, further comprising at least one cocatalyst selected from the group consisting of compounds represented by formulas (2) and (3):
(2)
[LH] ⁺ [ZA ₄ ] ^- or [L] ⁺ [ZA ₄ ] ^-
In Formula 2, L is a neutral or cationic Lewis acid; H is a hydrogen atom; Z is a Group 13 element; Each A is independently aryl having 6 to 20 carbon atoms or alkyl having 1 to 20 carbon atoms in which at least one hydrogen atom is substituted with halogen, hydrocarbyl having 1 to 20 carbon atoms, alkoxy having 1 to 20 carbon atoms, or a phenoxy radical;
(3)
-[Al (R8) -O] _n-
In Formula 3, R8 may be the same or different from each other, and each independently halogen; Hydrocarbons having 1 to 20 carbon atoms; Or a hydrocarbon having 1 to 20 carbon atoms substituted with halogen; n is an integer of 2 or more.

10. The catalyst composition according to claim 9, which is used as a catalyst composition for polyethylene polymerization.

A process for producing polyethylene, comprising the step of polymerizing a monomer composition comprising ethylene in the presence of an organochrome compound according to claim 1.

13. The method of claim 12, wherein the monomer composition comprises only ethylene as the monomer.