JPH1160627A - Preparation of alpha-olefin multimer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for preparing an α-olefin multimer which can efficiently produce a trimer of an α-olefin in a high yield with high selectivity by reacting an α-olefin in the presence of a specified transition metal compd. and an organoaluminum oxy compd. SOLUTION: A 2-30C (un)substd. α-olefin is reacted in the presence of a transition metal compd. represented by the formula (wherein M represents a transition metal; X<1> and X<2> represent each H, a halogen, or a substd. or unsubstd. straight-chain or branched alkyl; R<1> to R<3> represent each H, a hydroxyl group, or a substd. or unsubstd. alkyl, alkenyl, or aryl group, provided that R<1> to R<3> may mutually combine to form a ring or a crosslink, or two of R<1> to R<3> may be combined with each other to form an alkylidene, an alkenylidene, or an arylidene; T represents N, P, or O; and (k) is 2 or 4) and an organoaluminum oxy compd. at a pressure in the range of atmospheric pressure to 200 kg/cm<2> , pref. atmospheric pressure to 100 kg/cm<2> at a temp. of -40 to 150 deg.C, pref. 0 to 150 deg.C. This process is suitable particularly for the preparation of a 6C olefin which is a trimer of ethylene.

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. A method for obtaining hexene-1 has been 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]

The problem to be solved by the present invention is that 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 polymer comprising a step of reacting an α-olefin in the presence of a transition metal compound represented by the general formula [1] and an organoaluminum oxy compound.

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. (2) The transition metal compound represented by the general formula [2a] or [2
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 [3a] to [3g].

Embedded image [In the formula, Me represents a methyl group and Ph represents a phenyl group. (4) The method according to any one of the above (1) to (3), wherein the organoaluminum oxy compound is methylaluminoxane.

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 organic aluminum oxy compound. As the transition metal compound, a compound represented by the general formula [1] is used.

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 is bonded to the adjacent T. ^It may combine with ^{1 to} R 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],
The nickel (II) complex represented by the general formula [2a] or [2b] is preferable. General formulas [2a] and [2b]
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 [2a] indicates a complex in which ^two (TR ¹ R ² R ³ ) in the general formula [1] are coordinated, and the general formula [2b] indicates 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 [2a] and [2b] are those of the above formula [3a]
To [3 g]. The compound of the formula [3a] is bis (triphenylphosphine) nickel (II) bromide, which can be produced by reacting nickel bromide with triphenylphosphine.

The compound of the formula [3b] 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 [3c] 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 [3d] 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] of formula [3e] is nickel (II) chloride, which can be produced by reacting nickel chloride with 1,3- (diphenylphosphino) propane. .

The compound of the formula [3f] 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 [3g] 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 general formulas (1), (2a) and (2)
b) and the compounds of the formulas [3a] to [3g] are preferably prepared by introducing them into a reaction system to carry out the multimerization reaction. A compound of the formula may be formed and used as a multimerization catalyst.

The organoaluminum oxy compound used in the present invention may be a conventionally known aluminoxane or a benzene-insoluble organoaluminum oxy compound as exemplified in JP-A-2-78687. You may. The organoaluminum oxy compounds can be used alone or in combination of two or more.

The aluminoxane is produced, for example, by the following method, and is usually recovered as a solution in a hydrocarbon solvent. (1) Compounds containing water of adsorption or salts containing water of crystallization such as hydrated magnesium chloride, hydrated copper sulfate, hydrated aluminum sulfate, hydrated nickel sulfate, hydrated cerous chloride A method of adding an organoaluminum compound to a suspension in which is suspended in a hydrocarbon medium, and reacting the water of adsorption or water of crystallization with the organoaluminum compound. (2) A method in which water (water, ice or steam) is allowed to directly act on an organoaluminum compound in a medium such as benzene, toluene, ethyl ether, or tetrahydrofuran. (3) A method in which an organoaluminum compound is reacted with an organotin oxide such as dimethyltin oxide or dibutyltin oxide in a hydrocarbon medium such as decane, benzene or toluene.

The aluminoxane may contain a small amount of an organometallic component. The solvent or unreacted organoaluminum compound may be removed from the recovered aluminoxane solution by distillation, and then redissolved in a solvent or suspended in a poor aluminoxane solvent.

Specific examples of the organoaluminum compound used for producing the aluminoxane include trimethylaluminum, triethylaluminum, tripropylaluminum, triisopropylaluminum,
Tri-n-butylaluminum, triisobutylaluminum, trisec-butylaluminum, tritert
-Butyl aluminum, tripentyl aluminum, trihexyl aluminum, trioctyl aluminum,
Trialkyl aluminum such as tridecyl aluminum; tricycloalkyl aluminum such as tricyclohexyl aluminum and tricyclooctyl aluminum; dialkyl aluminum halide such as dimethyl aluminum chloride, diethyl aluminum chloride, diethyl aluminum bromide and diisobutyl aluminum chloride; diethyl aluminum hydride and diisobutyl Dialkylaluminum hydrides such as aluminum hydride; dialkylaluminum alkoxides such as dimethylaluminum methoxide and diethylaluminum ethoxide; and dialkylaluminum aryloxides such as diethylaluminum phenoxide. Among these, trialkylaluminum and tricycloalkylaluminum are particularly preferred.

As the organoaluminum compound used for preparing aluminoxane, isoprenylaluminum represented by the following general formula can also be used. _{(I-C 4 H 9)} x Al y (C 5 H 10) z ( wherein, x, y, z are each a positive number, and z ≧ 2x.) Organoaluminum compounds mentioned above, One type is used alone, or two or more types are used in combination.

Examples of the solvent used in the production of aluminoxane include benzene, toluene, xylene,
Aromatic hydrocarbons such as pentane, hexane, heptane, octane, decane, dodecane, hexadecane and octadecane; alicyclic hydrocarbons such as cyclopentane, cyclohexane, cyclooctane and methylcyclopentane Ethers such as ethyl ether and tetrahydrofuran; gasoline, kerosene,
Petroleum fractions such as gas oil; and hydrocarbon solvents such as the above-mentioned aromatic hydrocarbons, aliphatic hydrocarbons, and alicyclic hydrocarbon halides, for example, chlorinated products and brominated products. Among these solvents, aromatic hydrocarbons and aliphatic hydrocarbons are particularly preferred.

In the benzene-insoluble organoaluminum oxy compound used in the present invention, the Al component soluble in benzene at 60 ° C. is usually 10% or less, preferably 5% or less, particularly preferably 2% or less in terms of Al atom. Yes, insoluble or poorly soluble in benzene.

In the method for producing an α-olefin multimer of the present invention, the α-olefin as a raw material is multiplied in a solvent using a catalyst system comprising the above 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 organic aluminum oxy compound to be used is generally 0.01 mmol to 10000 mmol, preferably 0.1 mmol to 1000 mmol, in terms of Al atoms, per 1 mmol of the transition metal compound.

Pentane, hexane,
Linear or alicyclic saturated hydrocarbons such as cyclohexane, methylcyclohexane, heptane, octane and decalin; benzene, toluene, ethylbenzene, xylene,
Aromatic hydrocarbons such as mesitylene and tetralin; aliphatic ether compounds such as diethyl ether, diisopropyl ether, tetrahydrofuran and dioxane; chain chlorinated hydrocarbons such as dichloromethane, chloroform, carbon tetrachloride and dichloroethane; and chlorobenzene and dichlorobenzene Chlorinated aromatic hydrocarbons and the like are used. These can be used alone or as a mixed solvent. In particular, aromatic hydrocarbons such as benzene, toluene, ethylbenzene, xylene, mesitylene, and tetralin; aliphatic ether compounds such as diethyl ether, diisopropyl ether, tetrahydrofuran, and dioxane; chain chlorinations such as dichloromethane, chloroform, carbon tetrachloride, and dichloroethane. Hydrocarbons are preferred because of their high catalytic activity.

The reaction temperature is usually in the range of -40 to + 150 ° C, preferably 0 to 150 ° C. The reaction pressure is normal pressure to 200 kg / cm ² , preferably normal pressure to 100 kg / cm ² .
cm ² . The reaction time is not particularly limited and can be set as appropriate. In the present invention, the manner of contact between the transition metal compound and the organoaluminum oxy compound and the raw material α-olefin is not particularly limited, and the multimerization reaction can be selectively performed. Can be manufactured.

[0031]

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 ml two-neck glass flask was purged with vacuum nitrogen. This flask was placed in a nitrogen atmosphere under the above formula [3
a) bis (triphenylphosphine) nickel (II)
10% bromide (0.010 mmol) and toluene
After addition of water and substitution with ethylene at normal pressure, 3.00 ml of a methylaluminoxane solution (3.00 mmol in terms of Al atom) was added at room temperature, 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 The same procedures as in Example 1 were carried out except that the nickel compound of the catalyst was changed to the above-mentioned formulas [3b] to [3g] as shown in Table 1. . Table 1 shows the results of the composition analysis of the α-olefin multimer by gas chromatography.

Example 8 A 50 ml autoclave, which had been dried by heating, was assembled while being heated and then replaced with vacuum nitrogen. Bis (triphenylphosphine) nickel (II) bromide (0.010 mmol) of the formula [3a] was added to this autoclave under a nitrogen atmosphere.
Methylaluminoxane (3.00 mmol) and 10 ml of toluene were added, and the total ethylene pressure was 30 kg / cm ^2.
Until the temperature reached 100 ° C., 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.

[0037]

[Table 1]

Note to Table 1: TON (Turn Over Number); the amount (mol) of olefin multimer formed per Ni catalyst (mol) 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.

[0040]

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. The method of claim 1 wherein α-α is present in the presence of a transition metal compound represented by the general formula [1] and an organic aluminum oxy compound.
A method for producing an α-olefin polymer comprising a step of reacting an olefin. 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. ] 2. The method according to claim 1, wherein the transition metal compound is selected from compounds represented by the general formula [2a] or [2b]. 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 [3a] to [3g]
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. The method according to claim 1, wherein the organoaluminum oxy compound is methylaluminoxane.