JPH07157444A - Method for producing linear alpha-olefin - Google Patents

Abstract

PURPOSE:To provide a method for producing a 4-10C linear alpha-olefin in high activity and in high selectivity by oligomerizing ethylene. CONSTITUTION:Ethylene is oligomerized in the presence of a catalyst system of the formula ((ml) is 0.1-1000; (n) is 1, 1.5, 2, 3; R is a 1-20C alkyl; X<1>, X<2> are each a halogen) and a Lewis acid, preferably aluminum chloride, aluminum bromide or stannous chloride, at 10-180 deg.C preferably 30-150 deg.C, and under an absolute pressure of 0-200kg/cm<2>, preferably 10-150kg/cm<2>, to produce a 4-10C linear alpha-olefin. The catalyst system can be prepared by charging a zirconium halide, preferably ZrCl4, in a solvent and subsequently charging an alkyl aluminum compound, preferably Al(C2H5)2Cl, into the produced suspension. The Lewis acid is added in an amount of 0.010-50 equivalents, preferably 0.015-10 equivalents, per mole of zirconium.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a chain α-olefin having 4 to 10 carbon atoms. The chain α-olefin having 4 to 10 carbon atoms obtained in the present invention is utilized as a comonomer for modifying high-density polyethylene (HDPE) or linear low-density polyethylene (LLDPE), or as a plasticizer and poly-α-. It is a very useful compound as a raw material for olefins.

[0002]

2. Description of the Prior Art It is known to produce chain .alpha.-olefins using a Ziegler catalyst system in a reaction for oligomerizing ethylene. This technology is, for example,
-39003, Japanese Patent Publication No. 2-37883, Japanese Patent Publication No. 3-33133 and Chemical R
E-views, 91, 613 (1991) and the like. However, in the method using the Ziegler catalyst system described above, in addition to the chain α-olefin having 4 to 10 carbon atoms, a large amount of chain α-olefin having 12 or more carbon atoms and wax having 32 or more carbon atoms are produced. In addition, Chemical
In Reviews, influence of reaction pressure, reaction temperature, ratio of zirconium compound to alkylaluminum compound of Ziegler catalyst system, kind of alkylaluminum compound, etc. on distribution of chain α-olefin produced in oligomerization reaction of ethylene. It is disclosed.
According to this document, the higher the ratio of the alkylaluminum compound to the zirconium compound and the more cationic the zirconium compound, the greater the selectivity of the chain α-olefin having 4 to 10 carbon atoms. However, the selectivity of the desired chain α-olefin is still insufficient, and there is a drawback that the amount of wax produced as a by-product is too large.

Therefore, some attempts have been made to selectively obtain a chain α-olefin having 4 to 10 carbon atoms in the ethylene oligomerization reaction. For example, Japanese Patent Publication No. 2-13649 discloses a method of using a phenoxy group-containing zirconium compound having an electron-withdrawing substituent on an aromatic ring and an alkylaluminum compound as a catalyst, and selecting a desired α-olefin of 80% or more. You are getting at a rate. However, this method requires that the ratio of the alkylaluminum compound to the zirconium compound is 15 or more, so that the yield of the chain α-olefin is low with respect to the catalyst composed of the zirconium compound and the alkylaluminum compound, and the aroma is not high. This is a big problem from the economical point of view, such as using an expensive phenoxy group-containing zirconium compound having an electron-withdrawing substituent on the ring.

Japanese Patent Publication No. 4-80014 and WO9
No. 2-10446 discloses a catalyst system composed of a zirconium compound, an alkylaluminum compound, and a phosphine compound or an ether compound. However, this method also has a drawback that the catalytic activity is low and that a phosphine or an ether compound is mixed in the product chain α-olefin.

[0005]

Therefore, in a reaction for oligomerizing ethylene, a chain α having 12 or more carbon atoms is formed.
The development of a method for suppressing the by-product of olefins and waxes having 32 or more carbon atoms and obtaining a chain α-olefin having 4 to 10 carbon atoms with high activity and high selectivity has been expected. That is, the object of the present invention is to have a highly active and highly selective carbon number of 4-10.
The present invention provides a method for producing a chain α-olefin of

[0006]

[Means for Solving the Problems] In view of such a current situation,
The present inventors diligently studied the oligomerization reaction of ethylene. As a result, in the reaction for oligomerizing ethylene, when a Lewis acid is added to a catalyst system composed of zirconium halide and an alkylaluminum compound and reacted, a chain α-olefin having 4 to 10 carbon atoms is highly active and highly selective. The inventors have found that they can be obtained and completed the present invention.

That is, the present invention relates to a method for producing a chain α-olefin by oligomerizing ethylene, wherein the following general formula (1) Zr (X ¹ ) _4. [AlR _n (X ² ) _3-n ] _m ( 1) (In the formula, m is 0.1 to 1000, and n is 1, 1.
5, 2 or 3, R is an alkyl group having 1 to 20 carbon atoms, and X ¹ and X ² are halogen atoms, which are the same or different halogen atoms, respectively). A method for producing a chain α-olefin having 4 to 10 carbon atoms, which comprises adding and reacting. Hereinafter, the present invention will be described in more detail.

According to the present invention, the catalyst represented by the general formula (1), which comprises zirconium halide and an alkylaluminum compound, is used in the reaction for oligomerizing ethylene. The zirconium halide used in the present invention is Zr (X ¹ ) ₄ , where X ¹ represents a halogen atom. The halogen atom is chlorine, bromine, fluorine or iodine, and the four X ^1's may be the same or different halogen atoms. These are, for example, Zr
F ₄ , ZrCl ₄ , ZrBr ₄ , ZrI ₄ , ZrBrC
l ₃ , ZrBr ₂ Cl ₂ and ZrBr ₃ Cl, of which ZrCl ₄ is preferably used. The zirconium halides may be used alone or in combination of two or more.

The alkylaluminum compound used in the present invention is AlR _n (X ² ) _3-n . Where n
Is 1, 1.5, 2 or 3, and R is 1 to 20 carbon atoms.
And the alkyl group X ² represents a halogen atom. The halogen atom is chlorine, bromine, fluorine or iodine, and (3-n) X ^2's may be the same or different halogen atoms. In this AlR _n (X ² ) _3-n , when n is 1.5, it becomes AlR _1.5 (X ² ) _1.5 .
Although such a compound does not theoretically exist, it is usually conventionally expressed as a sesqui-form of Al ₂ R ₃ (X ² ) ₃ and these compounds are also used in the present invention.

Examples of these alkyl aluminum compounds include Al (CH ₃ ) ₃ , Al (C ₂ H ₅ ) ₃ and Al
_{(N-C 3 H 7)} 3, Al (iso-C 3 H 7) 3, Al (n
_{-C 4 H 9) 3, Al} (iso-C 4 H 9) 3, Al (C 5 H
₁₁ ) ₃ , Al (C ₈ H ₁₇ ) ₃ , Al (CH ₃ ) ₂ Cl, Al
(C ₂ H ₅ ) ₂ Cl, Al (C ₂ H ₅ ) ₂ Br, Al (C
_{2 H 5) 2 I, Al} (C 2 H 5) 2 F, Al (n-C 3 H 7) 2
_{Cl, Al (iso-C 3} H 7) 2 Cl, Al (n-C 4 H
₉ ) ₂ Cl, Al (iso-C ₄ H ₉ ) ₂ Cl, Al (C ₅ H
₁₁ ) ₂ Cl, Al (C ₈ H ₁₇ ) ₂ Cl, Al (CH ₃ ) C
l _{2 and the} like.

Further, Al (C ₂ H ₅ ) Cl ₂ , Al (C ₂
H ₅ ) Br ₂ , Al (C ₂ H ₅ ) I ₂ , Al (C ₂ H ₅ ) F ₂ ,
_{Al (n-C 3 H 7} ) Cl 2, Al (iso-C 3 H 7) C
l ₂ , Al (n-C ₄ H ₉ ) Cl ₂ , Al (iso-C
_{4 H 9) Cl 2, Al} (C 5 H 11) Cl 2, Al (C 8 H 17)
Cl ₂ , Al ₂ (CH ₃ ) ₃ Cl ₃ , Al ₂ (C ₂ H ₅ ) ₃ C
_{l 3, Al 2 (n-} C 3 H 7) 3 Cl 3, Al 2 (iso-C 3
_{H 7) 3 Cl 3, Al} 2 (n-C 4 H 9) 3 Cl 3, Al 2 (i
_{so-C 4 H 9) 3} Cl 3, Al 2 (C 5 H 11) 3 Cl 3, Al
_{2 (C 8 H 17) 3} Cl 3 , and the like. Among these Al
(C ₂ H ₅ ) ₂ Cl is preferably used. These alkylaluminum compounds can be used alone, or two or more kinds can be mixed.

The catalyst system represented by the general formula (1), which is used in the present invention and comprises zirconium halide and an alkylaluminum compound, is prepared by contacting the zirconium halide and the alkylaluminum compound in an inert solvent. Can be prepared by The contact method is not particularly limited, but usually, zirconium halide is put into a solvent to prepare a zirconium halide suspension, and then the catalyst system is prepared by adding an alkylaluminum compound to the suspension. You can

The concentration of zirconium halide in preparing this catalyst system is not particularly limited, but is usually 10 to 200 mmol, preferably 20 per liter of solvent.
Used at a concentration of ~ 150 mmol. The amount of the alkylaluminum compound used is 0.1 to 1000 equivalents, preferably 0.5 to 500 equivalents, and more preferably 1.0 to 100 equivalents, relative to 1 mol of zirconium halide.
It is equivalent. Examples of the inert solvent include benzene, toluene, xylene, ethylbenzene, chlorobenzene,
Aromatic hydrocarbons such as chlorotoluene or halogen-substituted products thereof, saturated hydrocarbons such as pentane, hexane, heptane, octane, nonane, decane, cyclohexane, cyclooctane and decalin, and halogenated hydrocarbons such as dichloroethane are used. The temperature during preparation of the catalyst system is 10
-100 ° C, preferably 30-80 ° C. A catalyst system obtained at a temperature lower than this may not provide sufficient oligomerization activity, and conversely at a temperature higher than this, the wax having a carbon number of 32 or more may increase. Further, the preparation time of the catalyst system is 5 minutes to 5 hours, preferably 10 minutes to 2 hours.

According to the present invention, an ethylene oligomerization reaction is carried out by further adding a Lewis acid to the catalyst system comprising the zirconium halide and the alkylaluminum compound prepared as described above. Here, the Lewis acid is a compound having an atom capable of accepting an electron by expanding the outer shell valence orbit. Examples of Lewis acids include IIIA, IVA, and VIII metal halides of the Periodic Table of Elements. Examples of these Lewis acids include AlCl ₃ , AlBr ₃ , AlF ₃ , GaCl ₃ , and InCl.
₃ , TlCl ₃ , SnCl ₂ , SnCl ₄ , FeCl ₂ , F
Examples thereof include eCl ₃ , RuCl ₄ , OsCl _{4 and the} like. Of these, from the viewpoint of easy availability, chemical stability, etc.,
Aluminum chloride, aluminum bromide or stannic chloride are more preferably used. Further, the Lewis acids can be used alone, or two or more kinds can be mixed.

The Lewis acid may be added at the time of preparing a catalyst system comprising zirconium halide and an alkylaluminum compound, or may be added directly to the oligomerization reaction system. The addition amount of this Lewis acid is 0.010 to 50 equivalents, and preferably 0.015 to 10 equivalents, relative to 1 mol of zirconium. When the amount of the Lewis acid added is less than 0.010 equivalent to 1 mol of zirconium, the effect of adding the Lewis acid does not substantially appear. On the other hand, if the addition amount of the Lewis acid exceeds 50 equivalents to 1 mol of zirconium, the catalytic activity may decrease, which may be economically disadvantageous.

In the ethylene oligomerization of the present invention, the amount of the catalyst used is not particularly limited, but usually 0.01 to 100 millimoles of the catalyst represented by the general formula (1), and preferably 1 to 1 liter of the oligomerization reaction liquid. 0.1-
Used at a concentration of 50 mmol. At a catalyst concentration lower than this, sufficient oligomerization activity cannot be obtained, and on the contrary, at a catalyst concentration higher than this, the catalyst activity does not increase, which is not economical. At this time, the amount of the alkylaluminum compound used is 0.1 to 1 with respect to 1 mol of the zirconium halide.
It is 000 equivalents, preferably 0.5 to 500 equivalents, and more preferably 1.0 to 100 equivalents.

The ethylene oligomerization reaction in the present invention is carried out by adding a Lewis acid using the above catalyst, in which case a solvent is used. As the solvent, those mentioned in the preparation of the catalyst system can be used.
The reaction temperature for oligomerization is 10 to 180 ° C, preferably 30 to 150 ° C. The reaction pressure is 0 to 200 kg / cm ² in absolute pressure, preferably 10 to 15
It is 0 kg / cm ² . Moreover, the reaction time depends on the temperature and pressure and cannot be determined unconditionally.
Minutes to 6 hours. The raw material gas ethylene may contain a gas inert to the reaction, such as nitrogen, argon or helium. In addition, it is desirable that all operations from the preparation of the catalyst to the end of the oligomerization reaction are carried out while avoiding air and water. Further, it is preferable that ethylene, the catalyst preparation raw material and the solvent are sufficiently dried.

This reaction can be carried out batchwise, semi-continuously or continuously. After completion of the oligomerization reaction, a polymerization deactivator is added to the reaction solution to stop the reaction, and then unreacted ethylene is separated. After removing the by-produced wax and the deactivated catalyst, the formed chain α-olefin having 4 to 10 carbon atoms is separated from the reaction solution by a known extraction method or distillation method.

[0019]

EXAMPLES The present invention will be described in more detail below with reference to examples, but these examples show an outline of the present invention, and the present invention is not limited to these examples. .

Example 1 1.17 g (5.0 mmol) of zirconium tetrachloride and 50 ml of dried n-heptane were added to a Schlenk tube having an internal volume of 100 ml, and the mixture was stirred for 10 minutes. 12.5 ml of 1.0 M diethylaluminum chloride / n-hexane solution was added dropwise to this suspension, and the mixture was stirred at 70 ° C. for 30 minutes to prepare a catalyst. In a 200-ml Schlenk tube, 100 ml of n-heptane and 1.5 ml of undecane for internal standard were put, and then the catalyst solution was mixed with 23 mg (0.10 mmol) of anhydrous zirconium tetrachloride and 30 mg (0.25 mmo of diethylaluminum chloride).
l) was added separately. All the operations for preparing the catalyst solution were performed under a nitrogen atmosphere.

Internal volume 30 equipped with thermometer and stirrer
A 0 ml pressure-resistant stainless steel pressure reaction vessel was sufficiently replaced with nitrogen gas and then kept at 70 ° C. The catalyst solution was pressure-fed to this container with nitrogen, and then 10 mg of anhydrous aluminum chloride was added.
(0.075 mmol) was added. Agitation speed 600r
After adjusting to pm, the absolute pressure in the reaction vessel is 35 kg / cm
Blowing ethylene gas to ² and temperature 100 ℃
The temperature was raised to. Ethylene was continuously introduced so as to maintain the above pressure, and the reaction was carried out for 1 hour while maintaining these reaction conditions, and the catalyst was deactivated by injecting sodium hydroxide aqueous solution into the reaction vessel with nitrogen to cause the reaction. Ended.

The reaction vessel was cooled to room temperature and then depressurized. The wax component contained in the reaction solution was filtered using a filter paper, the filtrate was washed with 200 ml of pure water, and then dried with anhydrous potassium carbonate. The products contained in this reaction solution were analyzed by gas chromatography. The wax fraction separated by filtration was air-dried and then dried under reduced pressure (1 mmH
g, 100 ° C.) and weighed. The K value represents the relative proportion of the product chain α-olefin, and C
_{b + 2} / C _b (wherein, b is having 6 to 18, alpha-olefins represent the number of carbon atoms) is the average value of the molar ratio of. The lower K value indicates that the proportion of the chain α-olefin having 4 to 10 carbon atoms in the oligomerization product is higher. The yield of the C4 fraction was estimated from the K value. The results are shown in Table 1.

Example 2 33 mg (0.25 mmol) of anhydrous aluminum chloride
The reaction was performed in the same manner as in Example 1 except that it was used. The results are shown in Table 1.

Example 3 60 mg of diethylaluminum chloride was used in the reaction.
(0.50 mmol), anhydrous aluminum chloride 23m
The reaction was performed in the same manner as in Example 1 except that g (0.17 mmol) was used. The results are shown in Table 1.

Example 4 90 mg of diethyl aluminum chloride was added during the reaction.
(0.75 mmol), anhydrous aluminum chloride 33m
The reaction was performed in the same manner as in Example 1 except that g (0.25 mmol) was used. The results are shown in Table 1.

Example 5 121 mg of diethylaluminum chloride was used in the reaction.
(1.0 mmol), 44 mg of anhydrous aluminum chloride
The reaction was performed in the same manner as in Example 1 except that (0.33 mmol) was used. The results are shown in Table 1.

Examples 6-9 121 mg of diethylaluminum chloride was used in the reaction.
(1.0 mmol), 44 mg of anhydrous aluminum chloride
(0.33 mmol) was used, and the reaction was performed in the same manner as in Example 1 except that the reaction pressure and temperature were changed as shown in Tables 1 and 2. The results are shown in Tables 1 and 2.

Example 10 In the reaction, 29 mg (0.25 mmo) of triethylaluminum was used instead of diethylaluminum chloride.
l) and 33 mg of anhydrous aluminum chloride (0.25
mmol) was used, and the reaction was performed in the same manner as in Example 1. The results are shown in Table 2.

Example 11 The reaction was carried out in the same manner as in Example 1 except that 67 mg (0.25 mmol) of anhydrous aluminum bromide was used as the Lewis acid instead of anhydrous aluminum chloride. The results are shown in Table 2.

Example 12 The reaction was performed in the same manner as in Example 1 except that 6.5 mg (0.025 mmol) of stannic chloride was used as the Lewis acid instead of anhydrous aluminum chloride. The results are shown in Table 2.

Example 13 The reaction was performed in the same manner as in Example 1 except that 4.4 mg (0.017 mmol) of stannic chloride was used as the Lewis acid instead of anhydrous aluminum chloride. The results are shown in Table 2.

Comparative Example 1 The reaction was carried out in the same manner as in Example 1 except that anhydrous aluminum chloride was not added.
The results are shown in Table 2.

Comparative Example 2 60 mg of diethylaluminum chloride was used in the reaction.
(0.50 mmol) was used, and the reaction was performed in the same manner as in Example 1 except that anhydrous aluminum chloride was not added. The results are shown in Table 2.

Comparative Example 3 29 mg (0.25 mmol) of triethylaluminum was used instead of diethylaluminum chloride during the reaction.
Was used, and the reaction was performed in the same manner as in Example 1 except that anhydrous aluminum chloride was not added. The results are shown in Table 2.

[0035]

[Table 1]

[0036]

[Table 2]

The abbreviations in the table are as follows.

TEA; triethylaluminum DEAC; diethylaluminum chloride C4; butene, C6; hexene, C8; octene, C1
0: decene, C12 +; higher olefin of dodecene or higher Wax ratio = wax / (olefin having 4 to 30 carbon atoms + wax) × 100

[0039]

INDUSTRIAL APPLICABILITY According to the present invention, in the ethylene oligomerization reaction, the carbon number of 4 to 10 is highly active and highly selective.
It is possible to obtain a chain α-olefin of

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Claims (2)

[Claims] 1. A method for producing a chain α-olefin by oligomerizing ethylene, comprising the following general formula (1) Zr (X ¹ ) _4. [AlR _n (X ² ) _3-n ] _m (1) ( In the formula, m is 0.1 to 1000, and n is 1, 1.
5, 2 or 3, R is an alkyl group having 1 to 20 carbon atoms, and X ¹ and X ² are halogen atoms, which are the same or different halogen atoms, respectively). A method for producing a chain α-olefin having 4 to 10 carbon atoms, which comprises adding and reacting. 2. The method for producing a chain α-olefin according to claim 1, wherein the Lewis acid is aluminum chloride, aluminum bromide or stannic chloride.