JPH10101587A - Production of alpha-olefin oligomer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to obtain highly selectively and efficiently the subject compound, especially ethylene trimer in a high yield, by reacting a specific transition metal compound and an aluminum compound with an α-olefin. SOLUTION: An α-olefin is reacted in the presence of (A) a compound represented by the formula MX<1> X<2> (TR<1> R<2> R<3> )k [M is a transition metal; X<1> and X<2> are each H, a halogen or a (substituted)(branched)alkyl; R<1> to R<3> are each H, OH, a (substituted)(branched)alkyl, etc.; and may mutually be bonded to form a ring or a cross-linkage or two may be united to form an alkylidene, etc.; T is N, P or O; (k) is 2 or 4] [e.g. bis(triphenylphosphine)nickel(II) bromide] and (B) a compound represented by the formula R<4> m Al(OR<5> )n X<3> p Hq R<4> and R<5> are each a 1-15C hydrocarbon group; X<3> is a halogen; 0<(m)<=3; 0<=(n)<3; 0<=(p)<3; 0<=(q)<3; [(m)+(n)+(p)+(q)] is 3} (e.g. methylaluminum dichloride).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an α-olefin multimer (oligomer), and more particularly to an α-olefin suitable for selectively and efficiently producing a trimer C ₆ olefin from ethylene. -It relates to a method for producing an olefin multimer.

[0002]

2. Description of the Related Art An α-olefin polymer for a polyolefin raw material can be produced by increasing a relatively low molecular weight α-olefin. In recent years, 1-hexene, 1-octene, and the like, which can be produced by increasing the amount of ethylene, are useful as comonomers of linear low-density polyethylene (LLDPE), and their importance is increasing industrially. Conventionally, as a method for multiplying an α-olefin such as ethylene, a method using a chromium-based catalyst comprising a combination of a specific chromium compound and a specific aluminum compound has been known.

For example, JP-B-43-18707 discloses that a catalyst system comprising a transition metal compound of the VIA group represented by the general formula MXn (M) containing chromium and polyhydrocarbyl aluminum oxide (X) is used to convert ethylene into ethylene. 1
-A method for obtaining hexene is described. However, this method has low selectivity, and a large amount of polyethylene is by-produced simultaneously with 1-hexene. Further, there is a problem that the catalyst activity is reduced under the condition that the by-product of polyethylene is suppressed.

Japanese Patent Application Laid-Open No. 3-128904 discloses that
A method of trimerizing an α-olefin using a catalyst obtained by previously reacting a chromium-containing compound having a chromium-pyrrolyl bond with an alkyl metal or a Lewis acid is described. However, in this method, there is a problem that the catalytic activity is low and the multiplication cannot be performed efficiently.

On the other hand, a catalyst system comprising a nickel compound and an organoaluminum compound is known. For example, JP-B-62-19408 discloses a catalyst comprising (A) a nickel compound such as a nickel salt or a complex compound, (B) a bis-dialkylaluminoxane, (C) a phosphorus-containing compound, and (D) a halogenated phenol. A method for dimerizing a lower α-olefin using is described. However, this method can dimerize an α-olefin, but is not suitable for trimerization.

Japanese Patent Application Laid-Open No. 6-254402 discloses that
It is described that a catalyst obtained by combining a nickel compound such as a nickel salt or a complex compound with an organic aluminum oxy compound having 3 or more aluminum atoms trimerizes ethylene. However, this method has a problem that the selectivity of the trimer is low.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide α-
An olefin trimer can be efficiently produced with high yield and high selectivity.
_An object of the present invention is to propose a method for producing an α-olefin multimer capable of efficiently producing ₆ olefins with high yield and high selectivity.

[0008]

The present invention is the following method for producing an α-olefin multimer. (1) A method for producing an α-olefin multimer comprising a step of reacting an α-olefin in the presence of a transition metal compound represented by the general formula [1] and an aluminum compound represented by the general formula [2].

Embedded image MX ¹ X ² (TR ¹ R ² R ³ ) _k (1) wherein M is a transition metal, and X ¹ and X ² are each a hydrogen atom, a halogen atom, a straight-chain or branched And may be the same or different, and may have a substituent. R ^{1 to} R ³ are a hydrogen atom, a hydroxyl group, a linear or branched alkyl group, an alkenyl group or an aryl group, which may be the same or different, may have a substituent, They may combine to form a ring or a bridge, or two of them may combine to form an alkylidene group, an alkenylidene group or an arylidene group. T is a nitrogen atom, a phosphorus atom or an oxygen atom, which may be the same or different. k is 2 or 4
It is. ]

Embedded image R ⁴ _m Al (OR ⁵ ) _n X ³ _{pH q} (2) [wherein R ⁴ and R ⁵ are each a hydrocarbon group having 1 to 15 carbon atoms and are the same or different. X ³ represents a halogen atom. m is 0 <m ≦ 3, n is 0 ≦ n <3, p is 0 ≦ p <3, q is 0 ≦ q <3, and m is
+ N + p + q = 3. (2) When the transition metal compound has the general formula [3a] or [3
b) The method according to the above (1), which is selected from the compounds represented by b).

Embedded image Wherein X ¹ and X ² are each a hydrogen atom, a halogen atom,
It is a linear or branched alkyl group which may be the same or different and may have a substituent. R ^{1 to} R ³ are each a hydrogen atom, a hydroxyl group, a linear or branched alkyl group, an alkenyl group or an aryl group, which may be the same or different, and may have a substituent;
They may combine with each other to form a ring or a bridge, or the two may combine to form an alkylidene group, an alkenylidene group or an arylidene group. T ^{1 to} T ⁴
Is a nitrogen atom, a phosphorus atom or an oxygen atom, respectively.
They may be the same or different. (3) The method according to the above (1), wherein the transition metal compound is selected from compounds represented by formulas [4a] to [4g].

Embedded image [In the formula, Me represents a methyl group and Ph represents a phenyl group. (4) The aluminum compound is any of the general formulas [5a] to [5
d) The method according to any one of the above (1) to (3), which is selected from d).

Embedded image R ⁴ ₃ Al ... [5a] _{^{R 4 m AlX 3 3-m}} (m is 1.5 ≦ m <3) ... [5b] _{^{R 4 m Al (OR 5)}} 3-m (m is 0 <m <3) ... [5c] _{^{R 4 m AlH 3-m (}} m is 0 <m <3) ... [5d] [wherein a hydrocarbon group of R ^4, R ⁵ each having 1 to 15 carbon atoms X ³ may be the same or different, and X ³ represents a halogen atom. ]

In the present invention, α-
Olefin multimer (oligomer), generally 2
To 20-mer, preferably 3 to 10-mer, particularly trimer. As the α-olefin used as a raw material, a substituted or unsubstituted α-olefin having 2 to 30 carbon atoms is used. Specific examples include ethylene, propylene, 1-butene, 1-hexene, 1-octene, 3-methyl-1-butene, 4-methyl-1-pentene and the like. In particular, ethylene is preferred as the raw material α-olefin,
It is suitable for a method for producing a C ₆ olefin which is a trimer thereof from ethylene, and a C ₆ olefin can be obtained with high yield and high selectivity. Here, the C ₆ olefin which is a trimer of ethylene is mainly a branched olefin, and includes hexenes. The main C ₆ olefins include 3-methyl-2-pentene, 2-ethyl-
Examples thereof include 1-butene and 2-hexene. These contents vary depending on the reaction conditions.

In the present invention, the catalyst used for the α-olefin multimerization reaction is a catalyst system comprising the above transition metal compound and an aluminum compound. The compound represented by the general formula [1] is used as the transition metal compound, and the compound represented by the general formula [2] is used as the aluminum compound.

The transition metal represented by M in the general formula [1] is not particularly limited, but is preferably at least one transition metal selected from nickel, palladium, platinum, rhodium, iron, cobalt, and ruthenium. Is preferred. The compound of the general formula [1] is a complex of at least one transition metal selected from these.
Typical examples are nickel (II) complex, palladium (II) complex, platinum (II) complex, rhodium (II) complex, iron (II) complex, cobalt (II) complex, ruthenium (II) complex and the like. Is mentioned. Among these, a nickel (II) complex is preferred.

In the general formula [1], X ¹ and X ² are each a hydrogen atom, a halogen atom, a linear or branched alkyl group, which may be the same or different and have a substituent. Is also good. T is a nitrogen atom, a phosphorus atom or an oxygen atom, which may be the same or different.

In the general formula [1], R ^{1 to} R ³ each represent a hydrogen atom, a hydroxyl group, a carbon number of 1 to 15, preferably 1 to
8 linear or branched alkyl, alkenyl, or aryl groups, which may be the same or different, may have a substituent, and are mutually bonded to form a ring or a bridge. Or two may be combined to form an alkylidene group, an alkenylidene group or an arylidene group. In this case, the alkylidene group, alkenylidene group, or arylidene group bonded to each T is bonded to R ^{1 to} R ³ bonded to the same T to form a ring, or R ¹ to R bonded to the adjacent T. ^It may combine with ³ or an alkylidene group, an alkenylidene group or an arylidene group to form a crosslink. k is 2 or 4;

As the transition metal compound of the general formula [1],
Nickel (II) complexes represented by the general formulas [3a] and [3b] are preferable. General formulas [3a] and [3b]
In the formula, R ^{1 to} R ³ are the same as described above. T ^{1 to} T ⁴
Is a nitrogen atom, a phosphorus atom or an oxygen atom, which may be the same or different. The general formula [3a] shows a complex in which ^two (TR ¹ R ² R ³ ) in the general formula [1] are coordinated, and the general formula [3b] shows a complex in which four (TR ¹ R ² R ³ ) are coordinated.

Preferred examples of the nickel (II) complex represented by the general formulas [3a] and [3b] are those of the above formula [4a]
To [4 g]. The compound of the formula [4a] is bis (triphenylphosphine) nickel (II) bromide, which can be produced by reacting nickel bromide with triphenylphosphine.

The compound of the formula [4b] is bis [tris (4-
[Methoxyphenyl) phosphine] nickel (II) bromide, which can be produced by reacting nickel bromide with tris (4-methoxyphenyl) phosphine.
The compound of formula [4c] is bis [tris (pentafluorophenyl) phosphine] nickel (II) bromide,
It can be produced by reacting nickel bromide with tris (pentafluorophenyl) phosphine.

The compound of the formula [4d] is [1,2-bis (diphenylphosphino) ethane] nickel (II) chloride, which is obtained by reacting nickel chloride with 1,2-bis (diphenylphosphino) ethane. Can be manufactured.
Compound [1,3-bis (diphenylphosphino) propane] nickel (II) chloride of formula [4e], which can be produced by reacting nickel chloride with 1,3- (diphenylphosphino) propane. .

The compound of the formula [4f] is diphenyl (2-methoxyphenyl) phosphine nickel (II) bromide, which can be produced by reacting nickel bromide with diphenyl (2-methoxyphenyl) phosphine.
The compound of the formula [4g] is 2,2'-dipyridylbis (triphenylphosphine) nickel (II) bromide, which can be produced by reacting nickel bromide with 2,2'-dipyridyl and triphenylphosphine. it can.

The above general formulas (1), (3a) and (3)
b), the compounds of formulas [4a] to [4g] are preferably introduced into the reaction system to carry out the multimerization reaction, but the respective compounds can be reacted by introducing the respective raw materials into the reaction system. A compound of the formula may be formed and used as a multimerization catalyst.

In the aluminum compound represented by the general formula [2], R ⁴ and R ⁵ are each a hydrocarbon group having 1 to 15, preferably 1 to 8 carbon atoms, which may be the same or different. X ³ represents a halogen atom. m, n, p, q
Is the average number and indicates the above value.

Preferred examples of the aluminum compound represented by the general formula [2] include those represented by the general formulas [5a] to [5a].
[5d] compounds. General formulas [5a] to [5
In d), R ⁴ and R ⁵ are preferably an alkyl group, an alkenyl group or an aryl group having 1 to 15, preferably 1 to 8 carbon atoms. In the general formulas [5c] and [5d], m
Is 0 <m <3, preferably 1.5 ≦ m <3.

Specific examples of the above aluminum compounds include trimethylaluminum, triethylaluminum, triisobutylaluminum, diethylaluminum monochloride, ethylaluminum dichloride, diethylaluminum ethoxide, diethylaluminum hydride and the like.

In the method for producing an α-olefin multimer of the present invention, the raw material α-olefin is multiplied in a solvent using a catalyst system comprising the above-mentioned catalyst components, and the multimer is recovered. The amount of the transition metal compound used is, per 10 ml of the solvent,
Usually, the range is 1 × 10 ^{−4 to 5} g, preferably 1 × 10 ^{−3 to 4} g. The amount of the aluminum compound used is usually 0.01 mmol to 1 per 1 mmol of the transition metal compound.
0000 mmol, preferably 0.1 mmol to 100
The range is 0 mmol.

Examples of the solvent include linear or alicyclic saturated hydrocarbons such as pentane, hexane, cyclohexane, methylcyclohexane, heptane, octane and decalin;
Aromatic hydrocarbons such as benzene, toluene, ethylbenzene, xylene, mesitylene, tetralin, diethyl ether, diisopropyl ether, tetrahydrofuran,
Aliphatic ether compounds such as dioxane, chain chlorinated hydrocarbons such as dichloromethane, chloroform, carbon tetrachloride and dichloroethane, and chlorinated aromatic hydrocarbons such as chlorobenzene and dichlorobenzene are used. These can be used alone or as a mixed solvent.
Especially benzene, toluene, ethylbenzene, xylene,
Aromatic hydrocarbons such as mesitylene and tetralin, aliphatic ether compounds such as diethyl ether, diisopropyl ether, tetrahydrofuran and dioxane, and chain chlorinated hydrocarbons such as dichloromethane, chloroform, carbon tetrachloride and dichloroethane have high catalytic activities. It is suitable because it is.

The reaction temperature is usually in the range of -40 to + 150 ° C, preferably 0 to 150 ° C. The reaction pressure is from normal pressure to 200 kg / cm ² , preferably from normal pressure to 100 k
g / cm ² . The reaction time is not particularly limited and can be set as appropriate. In the present invention, the method of contacting the transition metal compound and the aluminum compound with the raw material α-olefin is not particularly limited, and the multimerization reaction can be selectively performed, and the polymer is selectively produced from the raw material α-olefin. can do.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples.

Example 1 A heated and dried 50 cc two-neck glass flask was purged with vacuum nitrogen. This flask was placed in a nitrogen atmosphere under the above formula [4
a) bis (triphenylphosphine) nickel (II)
10% bromide (0.010 mmol) and toluene
Then, the mixture was replaced with ethylene at normal pressure, and then 3.00 ml (3.00 m) of a methylaluminum dichloride solution was added at room temperature.
mol)), and after 0.5 hour of reaction, methanol was added to stop the reaction.

Gas analysis in the reaction system and analysis of products in the reaction solution were performed by gas chromatography.
As a result of observing the inner wall surface of the flask in this example, no adhesion of the by-product polymer was observed. Even when the reaction solution was treated with dilute hydrochloric acid, no polymer was found.
Table 1 shows the results of the composition analysis of the α-olefin multimer by gas chromatography.

Examples 2 to 7 In Example 1, as shown in Table 1, the reaction was carried out in the same manner as in Example 1 except that the nickel compound of the catalyst was changed to the above formulas [4b] to [4g]. . Table 1 shows the results of the composition analysis of the α-olefin multimer by gas chromatography. Ratio of isomers of C ₆ in the olefin in the second embodiment, 3-methyl-2-pentene 47 wt%, 2
-Ethyl-1-butene 21% by weight and 2-hexene 25% by weight.

Example 8 A 50 cc heat-dried autoclave was assembled while hot, and then replaced with vacuum nitrogen. Bis (triphenylphosphine) nickel (II) bromide (0.010 mmol) of the formula [4a] was added to the autoclave in a nitrogen atmosphere.
Methyl aluminum dichloride (3.00 mmol),
10 ml of toluene was added, and the total pressure of ethylene was 30 kg /
Ethylene was introduced until cm ² and the temperature was maintained at 100 ° C. After 0.5 hour, methanol was added into the autoclave to stop the reaction.

The pressure in the autoclave was released, degassing was performed, and gas analysis of the reaction system and analysis of products in the reaction solution were performed by gas chromatography. As a result of observing the inner wall surface of the autoclave in this example, no adhesion of the by-product polymer was observed. Even when the reaction solution was treated with dilute hydrochloric acid, no polymer was found. Table 1 shows the results of the composition analysis of the α-olefin multimer by gas chromatography.

[0032]

[Table 1]

Note to Table 1: TON (Turn Over Number); The amount (mol) of olefin multimer formed per gram atom of Ni is indicated on an ethylene basis.

From the results shown in Table 1, in each of Examples 1 to 8, ethylene trimer can be produced with high selectivity.
It can be seen that catalyst activities are high in 2, 4 to 8.

[0035]

According to the present invention, an α-olefin trimer can be selectively and efficiently produced in a high yield and selectively by using a specific catalyst. _Six olefins can be efficiently produced with high yield and high selectivity.

Claims (4)

[Claims] 1. Production of an α-olefin multimer comprising a step of reacting an α-olefin in the presence of a transition metal compound represented by the general formula [1] and an aluminum compound represented by the general formula [2] Method. Embedded image MX ¹ X ² (TR ¹ R ² R ³ ) _k (1) wherein M is a transition metal, and X ¹ and X ² are each a hydrogen atom, a halogen atom, a straight-chain or branched And may be the same or different, and may have a substituent. R ^{1 to} R ³ are a hydrogen atom, a hydroxyl group, a linear or branched alkyl group, an alkenyl group or an aryl group, which may be the same or different, may have a substituent, They may combine to form a ring or a bridge, or two of them may combine to form an alkylidene group, an alkenylidene group or an arylidene group. T is a nitrogen atom, a phosphorus atom or an oxygen atom, which may be the same or different. k is 2 or 4
It is. Embedded image R ⁴ _m Al (OR ⁵ ) _n X ³ _{pH q} (2) wherein R ⁴ and R ⁵ are each a hydrocarbon group having 1 to 15 carbon atoms and are the same or different. X ³ may represent a halogen atom. m is 0 <m ≦ 3, n is 0 ≦ n <3, p is 0 ≦ p <3, q is 0 ≦ q <3, and m is
+ N + p + q = 3. ] 2. The method according to claim 1, wherein the transition metal compound is selected from compounds represented by the general formula [3a] or [3b]. Embedded image Wherein X ¹ and X ² are each a hydrogen atom, a halogen atom,
It is a linear or branched alkyl group which may be the same or different and may have a substituent. R ^{1 to} R ³ are each a hydrogen atom, a hydroxyl group, a linear or branched alkyl group, an alkenyl group or an aryl group, which may be the same or different, and may have a substituent;
They may combine with each other to form a ring or a bridge, or the two may combine to form an alkylidene group, an alkenylidene group or an arylidene group. T ^{1 to} T ⁴
Is a nitrogen atom, a phosphorus atom or an oxygen atom, respectively.
They may be the same or different. ] 3. The transition metal compound of the formula [4a] to [4g]
The method according to claim 1, which is selected from the compounds represented by the following formulae. Embedded image [In the formula, Me represents a methyl group and Ph represents a phenyl group. ] 4. An aluminum compound represented by the general formula [5a]:
The method according to any one of claims 1 to 3, wherein the method is selected from [5d]. Embedded image R ⁴ ₃ Al ... [5a] _{^{R 4 m AlX 3 3-m}} (m is 1.5 ≦ m <3) ... [5b] _{^{R 4 m Al (OR 5)}} 3-m (m is 0 <m <3) ... [5c] _{^{R 4 m AlH 3-m (}} m is 0 <m <3) ... [5d] [wherein a hydrocarbon group of R ^4, R ⁵ each having 1 to 15 carbon atoms X ³ may be the same or different, and X ³ represents a halogen atom. ]