CATALYST SYSTEM FOR OLEFIN OLIGOMERIZATION AND METHOD FOR OLIGOMERIZING OLEFINS USING THE SAME

Abstract

The present invention relates to a catalyst system for olefin oligomerization, and a method for oligomerizing olefins using the same. The catalyst system for olefin oligomerization according to the present invention exhibits high selectivity to 1-hexene and 1-octene while having excellent catalytic activity, thereby enabling more efficient preparation of alpha-olefins.

Claims

1. A catalyst system for olefin oligomerization comprising: a ligand compound represented by Chemical Formula 1 below; a transition metal source; and a cocatalyst: ##STR00003## in the above Chemical Formula 1, E.sub.1 and E.sub.2 are each independently an element selected from the group consisting of boron (B), nitrogen (N), oxygen (O), silicon (Si), phosphorus (P), and sulfur (S), and R.sub.1 to R.sub.6 each independently represent hydrogen, an alkyl 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, a haloalkyl 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, an alkoxy group having 1 to 20 carbon atoms, an alkylsiloxy group having 1 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, a halogen group, or an amino group.

2. The catalyst system for olefin oligomerization of claim 1, wherein at least one of E.sub.1 and E.sub.2 in Chemical Formula 1 is nitrogen (N) or oxygen (O).

3. The catalyst system for olefin oligomerization of claim 1, wherein at least one of R.sub.1 and R.sub.4 in Chemical Formula 1 is an alkyl group, a cycloalkyl group, or an aryl group having 1 to 20 carbon atoms.

4. The catalyst system for olefin oligomerization of claim 1, wherein the ligand compound includes piperazine substituted with one or more functional groups selected from the group consisting of an alkyl group having 1 to 5 carbon atoms and a cycloalkyl group having 4 to 10 carbon atoms.

5. The catalyst system for olefin oligomerization of claim 1, wherein the ligand compound is selected from the group consisting of: ##STR00004##

6. The catalyst system for olefin oligomerization of claim 1, wherein the transition metal source includes one or more compounds selected from the group consisting of chromium(III) 2,2,6,6-tetramethylheptanedionate, chromium(III) 2-ethylhexanoate, chromium(III) tris(2-ethylhexanoate), chromium(III) naphthenate [Cr(NP).sub.3], chromium(III) chloride, chromium(III) bromide, chromium(III) fluoride, chromium(III) acetylacetonate, chromium(III) acetate, chromium(III) butyrate, chromium(III) neopentanoate, chromium(III) laurate, chromium(III) stearate, chromium(III) oxalate, chromium bromide, chromium fluoride, chromium chloride, chromium(II) bis(2-ethylhexanoate), chromium(II) acetate, chromium(II) butyrate, chromium(II) neopentanoate, chromium(II) laurate, chromium(II) stearate, and chromium(II) oxalate.

7. The catalyst system for olefin oligomerization of claim 1, wherein the cocatalyst one or more alkyl aluminum compounds selected from the group consisting of triethyl aluminum, tripropyl aluminum, tributyl aluminum, diethyl aluminum chloride, diethyl aluminum bromide, diethyl aluminum ethoxide, diethyl aluminum phenoxide, ethyl aluminum dichloride, and ethyl aluminum sesquichloride.

8. The catalyst system for olefin oligomerization of claim 1, wherein the molar ratio of the ligand compound to the transition metal source to the cocatalyst is in the range of 0.5:1:1 to 10:1:10,000.

9. A method for oligomerizing olefins comprising a step of subjecting an olefin to a multimerization reaction in the presence of the catalyst system for olefin oligomerization of claim 1.

10. The method for oligomerizing of claim 9, wherein the multimerization reaction temperature is 0 to 250 C.

11. The method for oligomerizing of claim 9, wherein the multimerization reaction pressure is 1 to 200 bar.

Description

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0056] The present invention will be described in more detail with reference to the following examples. However, these examples are given for illustrative purposes only, and the scope of the invention is not intended to be limited thereto.

Examples and Comparative Example: Preparation of a Catalyst System for Olefin Oligomerization

Example 1

[0057] 30 mL (21.3 mmol) of chromium(III) 2-ethylhexanoate was dissolved in anhydrous toluene and 63.8 mmol of 1-methylpiperazine ligand was added thereto.

[0058] In a separate vessel, 85.1 mmol of ethylaluminum dichloride and 319 mmol of triethylaluminum were mixed together.

[0059] Then, the mixed solution of ethylaluminum dichloride and triethylaluminum was slowly added to the chromium compound/ligand solution.

[0060] Subsequently, the dark yellowish brown solution was stirred for 5 minutes and the solvent was removed under vacuum.

[0061] The remaining oily liquid was diluted with 150 mL of cyclohexane and the solution was filtered to remove a black precipitate from the filtrate containing the catalyst system, and this was diluted with toluene to have a volume of 250 mL to prepare a catalyst system for olefin oligomerization.

Example 2

[0062] A catalyst system for olefin oligomerization was prepared in the same manner as in Example 1, except that 1000 ml of anhydrous cyclohexane was used instead of anhydrous toluene.

Example 3

[0063] A catalyst system for olefin oligomerization was prepared in the same manner as in Example 1, except that ethyl aluminum sesquichloride (85.1 mmol) was used instead of ethyl aluminum dichloride.

Comparative Example 1

[0064] A catalyst system for olefin oligomerization was prepared in the same manner as in Example 1, except that 2,5-dimethylpyrrole (63.8 mmol) was used instead of the 1-methylpiperazine ligand.

Experimental Example: Olefin Oligomerization

[0065] A 2 L stainless steel reactor was charged with nitrogen to which 1 L of reaction solvent was added, 3 mL of triethylaluminum was added, ethylene was charged at 10 bar, and the temperature was raised to 90 C.

[0066] Then, the catalyst solution prepared in Examples 1 to 3 or Comparative Example 1 was added to a reactor, charged with ethylene at 35 bar, and then stirred at a stirring speed of 500 rpm.

[0067] After one hour, feeding of ethylene to the reactor was stopped, the stirring was stopped, and the reaction was stopped. The reactor was cooled to below 10 C.

[0068] After excess ethylene was discharged from the reactor, ethanol mixed with 10 vol % hydrochloric acid was injected into the liquid contained in the reactor.

[0069] A small amount of the organic layer sample was passed over silica gel, dried, and then analyzed by GC-FID.

[0070] The remaining organic layer was filtered to separate the solid wax/polymer product.

[0071] These solid products were dried in an oven at 80 C. for 8 hours to give polyethylene and then weighed.

[0072] The results of the production of 1-hexene and 1-octene using the catalysts prepared in the respective examples and comparative example are shown in Table 1 below.

TABLE-US-00001 TABLE 1 1-hexene 1-octene PE Catalyst Reaction solvent (wt %) (wt %) Activity (g) xample 1 Cyclohexane 21.2 76.0 5.2 2.8 Example 1 Toluene 17.9 81.0 6.1 0.8 Example 2 Cyclohexane 20.4 77.5 4.5 2.1 Example 2 Toluene 25.9 72.9 3.2 1.2 Example 3 Cyclohexane 19.3 78.8 5.6 1.9 Example 3 Toluene 22.5 77.3 5.9 1.2 Comparative Cyclohexane 92.3 5.1 3.2 2.6 Example 1 * Catalytic activity unit: (Kg of Product/mmol of Cat)

[0073] As shown in Table 1, it was confirmed that the experimental examples using the catalyst systems of the examples produce a low amount of polyethylene (byproduct) while exhibiting high catalytic activity.

[0074] In addition, in the experimental examples using the catalyst systems of the examples, the selectivity to 1-octene was 70 wt % or more, which confirms that the 1-octene selectivity was significantly improved as compared with the case of using the catalyst system of the comparative example.