Ligand compound, catalyst system for olefin oligomerization, and method for olefin oligomerization using the same

Abstract

Provided are ligand compounds selected from among N-(diphenylphosphino)-1,1-diphenyl-N-(4-phenylbutan-2-yl)phosphinamine and N.sup.4,N.sup.4-bis(diphenylphosphino)-N.sup.1,N.sup.1-diethylpentane-1,4-diamine, a catalyst system for olefin oligomerization, and a method for olefin oligomerization using the same. The catalyst system for olefin oligomerization has excellent catalytic activity, and yet, exhibits high selectivity to 1-hexene or 1-octene, thus enabling more efficient preparation of alpha-olefin.

Claims

1. A ligand compound selected from the group consisting of: ##STR00011##

2. A catalyst system for olefin oligomerization, comprising the ligand compound according to claim 1, a source of transition metal and a cocatalyst.

3. The catalyst system according to claim 2, wherein the source of transition metal is at least one selected from the group consisting of chromium(III)acetylacetonate, tris(tetrahydrofuran)chromium trichloride, chromium(III)-2-ethylhexanoate, and chromium(III)tris(2,2,6,6-tetramethyl-3,5-heptanedionate).

4. The catalyst system according to claim 2, wherein the cocatalyst is at least one selected from the group consisting of the compounds of Chemical Formulae 2, 3 and 4:
[Al(R.sub.7)O]c-[Chemical Formula 2] wherein in the Chemical Formula 2, each R.sub.7 is identical or different, and are independently a halogen radical, a C1-20 hydrocarbyl radical, or a C1-20 hydrocarbyl radical substituted with halogen, and c is an integer of 2 or more,
D(R.sub.8).sub.3[Chemical Formula 3] wherein in the Chemical Formula 3, D is aluminum or boron, each R.sup.8 is identical or different, and are independently hydrogen, halogen, a C1-20 hydrocarbyl or a C1-20 hydrocaryl substituted with halogen,
[LH].sup.+[Q(E).sub.4].sup.[Chemical Formula 4] wherein in the Chemical Formula 4, L is a neutral Lewis base, [LH].sup.+is a Bronsted acid, Q is B.sup.3+or Al.sup.3+, and E is independently a C.sub.6-20 aryl group or a C.sub.1-20 alkyl group, unsubstituted or substituted with at least one group selected from the group consisting of halogen, C.sub.1-20 hydrocarbyl, a C.sub.1-20 alkoxy and phenoxy.

5. A method for olefin oligomerization, comprising the step of multimerizing olefins in the presence of the catalyst system for olefin oligomerization of claim 2.

6. The method for olefin oligomerization according to claim 5, wherein the olefin is ethylene.

7. The method for olefin oligomerization according to claim 5, wherein the multimerization temperature is 5 to 200 C.

8. The method for olefin oligomerization according to claim 5, wherein the multimerization pressure is 1 to 300 bar.

Description

DETAILED DESCRIPTION OF THE EMBODIMENTS

(1) Hereinafter, the present invention will be explained in detail with reference to the following examples. However, these examples are only to illustrate the invention and the scope of the invention is not limited thereto.

(2) <Synthesis of Ligand Compound>

SYNTHESIS EXAMPLE

(3) All the reactions were progressed using Schlenk technique or a Glove box under argon atmosphere. The synthesized compounds were analyzed by .sup.1H(500 MHz) and .sup.31P(202 MHz) NMR spectra using a Varian 500 MHz spectrometer. Shift was expressed in ppm, downfield from TMS, with a residual solvent peak as a reference. A phosphorous probe was calibrated with aqueous H.sub.3PO.sub.4. Under argon atmosphere, amine (10 mmol) and triethylamine (310 equiv. to amine) were dissolved in dichloromethane (80 mL). While the flaks was immersed in a water bath, chlorodiphenylphosphine(20 mmol) was slowly introduced, and the mixture was stirred overnight. The solvent was removed under vacuum, and then, another solvent (diethyl ether, tetrahydrofuran or hexane) was introduced, the mixture was sufficiently stirred, and triethylammoniumchloride salt was removed with an air-free glass filter. The solvent was removed in the filtrate to obtain a product. Starting amines for preparing ligands used in each Example and Comparative Example are shown in the following Table 1.

(4) TABLE-US-00001 TABLE 1 Synthesis Example Starting amine Ligand Synthesis Example 1 2-amino-4- phenylbutane Synthesis Example 2 4-Amino-1- diethylaminopentane Synthesis Example 3 1,2- diphenylethylamine Comparative Synthesis Example 1 2-aminopropane Comparative Synthesis Example 2 3-aminopentane Comparative Synthesis Example 3 2-amino-1- diethylaminopropane 0

(5) <Ethylene Oligomerization>

Example 1

(6) Under argon gas, Cr(acac).sub.3 (17.5 mg, 0.05 mmol) and the ligand prepared in the Synthesis Example 1 (0.1 mmol) were put in a flask, toluene (10 mL) was added, and the mixture was stirred to prepare a 5 mM solution.

(7) A 600 mL Parr reactor was prepared, vacuum was applied at 120 C. for 2 hours, and then, the temperature was decreased to 45 C., and the inside was replaced with argon. Cyclohexane (270 g) and 2 mL of MAO (10 wt % toluene solution, Al/Cr=300) were introduced, and 2 mL of the 5 mM solution(10 umol) was introduced in the reactor. The mixture was stirred at 500 rpm for 2 minutes, and then, a valve of an ethylene line adjusted to 45 bar was opened to fill the inside of the reactor with ethylene, and the mixture was stirred at 500 rpm for 15 minutes. The ethylene line valve was closed, the temperature was adjusted to 0 C., the reactor was cooled with an ice/acetone bath, and then, non-reacted ethylene was slowly vented, and 0.5 mL of nonane (GC internal standard) was put. Thereafter, 2 mL of the liquid part of the reactor was taken and quenched with water, and the organic part was filtered with a PTFE syringe filter to make a GC sample. The GC sample was analyzed with GC. To the remaining reaction solution, 400 mL of ethanol/HCl (10 vol %) was added, and the mixture was stirred and filtered to obtain polymer. The obtained polymer was dried overnight in a 65 C. vacuum oven.

Example 2

(8) A reaction was conducted by the same method as Example 1, except using 1 ml (5 umol) of the catalyst 5 mM solution.

Example 3

(9) A reaction was conducted by the same method as Example 1, except using the ligand prepared in Synthesis Example 2.

Example 4

(10) A reaction was conducted by the same method as Example 2, except using the ligand prepared in Synthesis Example 2.

Example 5

(11) A reaction was conducted by the same method as Example 1, except using the ligand prepared in Synthesis Example 3.

Comparative Example 1

(12) Under argon gas, Cr(acac).sub.3 (17.5 mg, 0.05 mmol) and the ligand prepared in the Comparative Synthesis Example (0.1 mmol) were put in a flask, toluene (10 mL) was added, and the mixture was stirred to prepare a 5 mM solution.

(13) A 600 mL Parr reactor was prepared, vacuum was applied at 120 C. for 2 hours, and then, the temperature was decreased to 45 C., and the inside was replaced with argon. And then, 300 g of toluene and 2 mL of MAO (10 wt % toluene solution, Al/Cr=300) were introduced, and 2 mL of the 5 mM solution (10 umol) was introduced in the reactor. The mixture was stirred at 500 rpm for 2 minutes, and then, a valve of an ethylene line adjusted to 45 bar was opened to fill the inside of the reactor with ethylene, and the mixture was stirred at 500 rpm for 30 minutes. The ethylene line valve was closed, the temperature was adjusted to 0 C., the reactor was cooled with an ice/acetone bath, and then, non-reacted ethylene was slowly vented, and 0.5 mL of nonane(GC internal standard) was put. Thereafter, 2 mL of the liquid part of the reactor was taken and quenched with water, and the organic part was filtered with a PTFE syringe filter to make a GC sample. The GC sample was analyzed with GC. To the remaining reaction solution, 400 mL of ethanol/HCl (10 vol %) was added, and the mixture was stirred and filtered to obtain polymer. The obtained polymer was dried overnight in a 65 C. vacuum oven.

Comparative Example 2

(14) A reaction was conducted by the same method as Comparative Example 1, except using a ligand prepared in Comparative Synthesis Example 2, and using 1 ml (5 umol) of the catalyst 5 mM solution.

Comparative Example 3

(15) A reaction was conducted by the same method as Comparative Example 1, except using a ligand prepared in Comparative Synthesis Example 3.

(16) The results of Examples 1 to 5 and Comparative Examples 1 to 3 are shown in the following Table 2.

(17) TABLE-US-00002 TABLE 2 Activity Selectivity (wt %) Solid PE (kg/mol/Cr/hr) 1-hexene 1-octene Sum (wt %) Comparative 5182 14.4 69.6 84.0 1.1 Example 1 Comparative 10269 14.0 70.1 84.1 0.11 Example 2 Comparative 1600 9.9 36.5 46.4 2.3 Example 3 Example 1 14177 17.5 69.1 86.6 0.53 Example 2 11280 15.8 70.3 86.1 0.85 Example 3 8111 20.6 66.6 87.2 0.53 Example 4 12603 15.2 70.1 85.3 0.18 Example 5 6017 19.6 67.2 86.8 0.80

(18) From the results of the Table 2, it can be seen that in the case of Examples, compared to Comparative Examples, very high multimerization activity is exhibited, selectivity to 1-hexene and 1-octene is remarkably improved, and the amount of by-product, solid PE is small.