JPH09268135A - Production of 1-hexene - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing 1-hexene by trimerizing ethylene in the presence of a chromium catalyst comprising three components, capable of obtaining the 1-hexene in extremely high purity by using an aliphatic hydrocarbon as a solvent and adding a specific aromatic hydrocarbon in a specified amount to the reaction system. SOLUTION: This method for producing 1-hexene comprises trimerizing ethylene in the presence of a chromium catalyst comprising a chromium compound, an alkyl metal compound and highly safe and easily handleable imide compound. Therein, an aliphatic hydrocarbon is used as a solvent, and a 1-6C alkyl or halogen atom-substituted or non-substituted aromatic hydrocarbon is further added to the reaction system in an amount of 0.01-50vol.% based on the charged solution. The solvent is preferably cyclohexane, heptane, etc. The aromatic hydrocarbon is preferably toluene, butylbenzene, etc. The chromium compound is preferably a chromium carboxylate compound, etc., and the alkyl metal compound is preferably triethyl aluminum, etc. The imide compound is preferably maleimide, etc.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a method for producing 1-hexene by trimerizing ethylene. The 1-hexene obtained in the present invention is a linear low density polyethylene (LLD).
It is an extremely useful compound as a raw material comonomer for PE) or a raw material for a plasticizer.

[0002]

2. Description of the Prior Art It is known to produce 1-hexene using a chromium catalyst in a reaction for trimerizing ethylene. For example, in U.S. Pat. No. 3,347,840 and JP-A-62-265237, catalyst systems comprising chromium compounds, aluminoxanes and ether compounds such as dimethoxyethane are disclosed in JP-A-6-239920. Discloses a catalyst system consisting of a chromium compound, a pyrrole-containing compound, a metal alkyl.

On the other hand, the present inventors previously mentioned that
We proposed an easy-to-handle low-polymerization catalyst for olefins consisting of an alkyl metal compound and an imide compound, and a low-polymerization reaction for olefins using the catalyst. According to this method,
1-Hexene can be obtained with high activity by a low polymerization reaction of olefin, particularly by a trimerization reaction of ethylene.

[0004]

Generally, in the trimerization reaction of ethylene using a chromium catalyst, it is necessary to treat the waste chromium catalyst at the end of the trimerization reaction, but chromium, which is the main catalyst metal, is extremely different depending on the structure. Make highly toxic compounds. Therefore, in terms of safety, it is necessary to use as little chromium metal as possible. However, U.S. Pat. No. 3,347,840 and JP-A-62-26.
The method described in Japanese Patent No. 5237 has a problem that the catalytic activity is not sufficient and a large amount of chromium metal must be used. Further, the method described in JP-A-6-239920 has significantly improved catalytic activity and is excellent in suppressing the amount of chromium metal used. However, one component of the catalyst, pyrrole, is a unstable compound that is poor in storage stability, such as easily colored and deteriorated, so it is difficult to handle, and it is not yet sufficient as an industrial catalyst. It was

The present invention has been made in view of the above problems, and an object thereof is to use a catalyst system which is easy to handle and highly active in a reaction for trimerizing ethylene, and which is highly selective. It is to provide a method for producing hexene.

[0006]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that a chromium catalyst comprising a chromium compound, an alkyl metal compound and a highly stable and easily handled imide compound. In the reaction of trimerizing ethylene in the presence of, by using an aliphatic hydrocarbon as a solvent and further adding a specific aromatic hydrocarbon to the reaction system in an amount within a specific range, 1-hexene can be obtained with extremely high purity. As a result, they have completed the present invention.

That is, the present invention uses an aliphatic hydrocarbon as a solvent in a reaction for trimerizing ethylene in the presence of a chromium catalyst composed of a chromium compound, an alkyl metal compound and an imide compound, and further uses an alkyl group having 1 to 6 carbon atoms. Base,
The present invention relates to a method for producing 1-hexene, characterized in that a halogen atom-substituted or unsubstituted aromatic hydrocarbon is added to the reaction system at a rate of 0.01 to 50% by volume of the charged solution.

[0008]

Next, the present invention will be described in more detail.

In the present invention, a chromium catalyst composed of a chromium compound, an alkyl metal compound and an imide compound is used. The imide compound used in the present invention may be any compound as long as it is a compound having an imide structure, and examples thereof include maleimide and 1-chloroethene-1,2-.
Dicarboximide, 1-bromoethene-1,2-dicarboximide, 1-fluoroethene-1,2-dicarboximide, 1-trifluoromethylethene-1,2
-Dicarboximide, 1,2-dichloroethene-1,
2-dicarboximide, citraconimide, 2-butene-2,3-dicarboximide, 1-cyclopentene-1,2-dicarboximide, succinimide, α,
α-dimethyl-β-methylsuccinimide, α-methyl-α-propylsuccinimide, glutarimide, 3,
3-dimethylglutarimide, bemeglide, phthalimide, 3,4,5,6-tetrachlorophthalimide, 1,
2-cyclohexanedicarboximide, 1,2,3
6-tetrahydrophthalimide, 1,2,3,4-tetrahydrophthalimide, 3,4,5,6-tetrahydrophthalimide, 1,8-naphthalimide, 2,3-naphthalenedicarboximide, cycloheximide, N-
Chloro succinimide, N-bromosuccinimide, N
-Iodosuccinimide, N- (methoxycarbonyl)
Examples include imides such as maleimide, N- (hydroxy) maleimide and N- (carbamoyl) maleimide.

Further, N- (trimethylsilyl) maleimide, N- (trimethylsilyl) succinimide, N-
(Trimethylsilyl) citraconimide, N- (trimethylsilyl) -2-butene-2,3-dicarboximide, N- (trimethylsilyl) -1-cyclopentene-
1,2-dicarboximide, N- (trimethylsilyl) -3,4,5,6-tetrahydrophthalimide, N
-(Trimethylsilyl) succinimide, N- (triethylsilyl) maleimide, N- (tri-n-propylsilyl) maleimide, N- (tri-n-butylsilyl) maleimide, N- (tri-n-hexylsilyl) maleimide, N -(Tribenzylsilyl) maleimide, N- (n
-Butyldimethylsilyl) maleimide, N- (t-butyldimethylsilyl) maleimide, N- (dimethylzexylsilyl) maleimide, N- (n-octyldimethylsilyl) maleimide, N- (n-octadecyldimethylsilyl) maleimide, N- (benzyldimethylsilyl) maleimide, N- (methyldibutylsilyl) maleimide,
N- (phenyldimethylsilyl) maleimide, N- (p
-Methoxyphenyldimethylsilyl) maleimide, N-
(P-toluyldimethylsilyl) maleimide, N- (triphenylsilyl) maleimide, N- (tributyltin) maleimide, N- (trioctyltin) maleimide, N- (diisobutylaluminum) maleimide, N
Metal imides such as-(diethylaluminum) maleimide, mercury maleimide, silver maleimide, calcium maleimide, potassium maleimide, sodium maleimide, and lithium maleimide; Of these, from the aspect of activity, the following general formula (1)

[0011]

Embedded image

(In the formula, d is an integer of 1 to 4. M is hydrogen or IA, IIA, IB, IIB, II of the Periodic Table.
It represents a substituent-containing or unsubstituted metal element of group IB or IVB. R ¹ and R ² each represent hydrogen, an alkyl group having 1 to 10 carbon atoms, a halogen atom, an aryl group, or R ¹ and R ^2;
Represents at least one selected from the group consisting of cyclic substituents bonded by a carbon-carbon bond). More preferably maleimide, N- (trimethylsilyl) maleimide or N-
(Tributyltin) maleimide is used. In addition, the imide compounds can be used alone or in combination of two or more.

Here, the metal imide is a metal imide derived from imide or a mixture thereof, and specifically, imide and IA group, IIA group, IB group, IIB.
An imide compound obtained by a reaction with a metal selected from Group IIIB, Group IIIB and Group IVB. The method for synthesizing the metal imide compound is not particularly limited, and can be synthesized by a known method. For example, imide compounds of Group IA and IIA metals include IA and II such as lithium, butyllithium, sodium, sodium hydride, potassium hydride, methylmagnesium bromide, and butylmagnesium chloride.
It can be synthesized by reacting a group A metal compound with an imide compound. The imide compounds of IB and IIB metals can be synthesized by reacting IB and IIB metal compounds such as silver nitrate, silver chloride and mercury chloride with imide compounds in the presence of an alkali. The imide compound of a Group IIIB or IVB metal can be obtained by reacting an imide compound with a Group IIIB or IVB metal chloride such as trimethylsilyl chloride, tributylsilyl chloride, tributyltin chloride or diethylaluminum chloride in the presence of an alkali.
Group IIB and IVB metal chlorides with IA, IIA, I
Reacting a metal imide compound of group B or IIB, or
It can be synthesized by reacting an imide compound with a IIIB or IVB group metal hydride such as tributyltin hydride or triisobutylaluminum hydride. Specifically, Polymer Journal, 24, 679
According to (1992), N- (trialkylsilyl) maleimide is synthesized by reacting maleimide or silver maleimide with a trialkylsilyl chloride in the presence of a tertiary amine compound, followed by distillation or recrystallization. Also, J
ournalof Organic Chemistr
According to y, 39, 21 (1974), silver maleimide is synthesized by reacting maleimide and silver nitrate in ethanol / dimethyl sulfoxide in the presence of caustic soda.

The amount of the imide compound used is usually 0.1 to 1,000 equivalents, preferably 0.5 to 500 equivalents, and more preferably 1 to 300 equivalents, relative to 1 mol of the chromium compound.
Is equivalent. When the amount of the imide compound used is less than 0.1 equivalent to 1 mol of the chromium compound, low polymerization reaction activity cannot be sufficiently obtained, and a large amount of polymer is produced as a by-product. On the other hand, if the amount used exceeds 1,000 equivalents relative to 1 mol of the chromium compound, the catalytic activity tends to decrease, which is not economically preferable.

The chromium compound used in the present invention is not particularly limited, but for example, the following general formula (2) CrA _m B _n (2) (where m is an integer of 1 to 6) , N is an integer of 0 to 4. A is an alkyl group having 1 to 20 carbon atoms, an aryl group, an arene, an alkoxy group, a carboxylate group, β.
-Diketonate groups, β-ketoester groups and amide groups,
Represents at least one selected from the group consisting of a halogen atom, a hydroxyl group, a nitrate group, a sulfate group, a perchlorate group, carbonyl and oxygen, and B represents a nitrogen-containing compound, a phosphorus-containing compound, an arsenic-containing compound, an antimony-containing compound. Compound,
A compound represented by at least one selected from the group consisting of oxygen-containing compounds and sulfur-containing compounds) is preferably used.

In the general formula (2), the number of carbon atoms is 1 to 2.
The alkyl group of 0 is not particularly limited, and examples thereof include a methyl group, an ethyl group, a butyl group, an allyl group, a neopentyl group, a cyclopentadienyl group, a pentamethylcyclopentadienyl group, and a trimethylsilylmethyl group. Is mentioned. The aryl group having 6 to 20 carbon atoms is not particularly limited, and examples thereof include a phenyl group and a toluyl group. The arene having 6 to 20 carbon atoms is not particularly limited, and examples thereof include benzene, ethylbenzene, and hexamethylbenzene. Although it does not specifically limit as a C1-C20 alkoxy group, For example, a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a hexyloxy group, a stearyloxy group, a phenoxy group, etc. are mentioned. Examples of the carboxylate group having 1 to 20 carbon atoms include, but are not particularly limited to, an acetate group, a propionate group, a butyrate group, a neopentanoate group, a 2-ethylhexanoate group, and an oxy-2 group. -Ethylhexanoate group, isooctanoate group, dichloroethylhexanoate group, laurate group, stearate group, oleate group, benzoate group or naphthenate group. Examples of the β-diketonate group having 1 to 20 carbon atoms include, but are not particularly limited to, acetylacetonate group, trifluoroacetylacetonate group, hexafluoroacetylacetonate group,
2,6,6-tetramethyl-3,5-heptanedionate group, 1,3-butanedionate group, 2-methyl-1,
Examples thereof include a 3-butanedionate group and a benzoylacetonate group. Although it does not specifically limit as a C1-C20 (beta) -ketoester group, For example, an acetylacetate group etc. are mentioned. The amide group is not particularly limited, but includes, for example, a dimethylamide group or a dicyclohexylamide group. Although it does not specifically limit as a halogen atom, For example,
Fluorine, chlorine, bromine or iodine.

In the general formula (2), the nitrogen-containing compound is not particularly limited, but examples thereof include amine, pyridine, amide, and nitrile. Although it does not specifically limit as a phosphorus compound, For example, a phosphine, a phosphite, a phosphine oxide, etc. are mentioned. As the oxygen-containing compound,
Although it is not particularly limited, for example, water, carboxylic anhydride, ester, ether, alcohol or ketone, and the sulfur-containing compound is not particularly limited, and examples thereof include carbon disulfide, sulfone, and thiophene. , Or sulfide and the like.

The chromium compound represented by the general formula (2) is not particularly limited, but for example, chromium (II) dimethyl, chromium (III) trimethyl, chromium (IV) tetramethyl, chromium (III). Tris (η-allyl), dichromium (II) tetrakis (η-allyl), chromium (IV) tetrakis (neopentyl),
Chromium (IV) tetrakis (trimethylsilylmethyl), chromium (II) bis (cyclopentadienyl),
Chromium (II) bis (pentamethylcyclopentadienyl), chromium (III) tris (π-allyl), chromium (IV) tetrakis (π-allyl), chromium (II) diphenyl, chromium (0) bis (benzene) , Chrome (I
I) diphenyl (benzene), chromium (0) bis (ethylbenzene), chromium (0) bis (hexamethylbenzene), chromium (I) cyclopentadienyl (benzene), chromium (IV) tetramethoxide, chromium (I
V) tetraethoxide, chromium (IV) tetrapropoxide, chromium (IV) tetrabutoxide, chromium (I
V) Tetrahexyl oxide, chromium (IV) tetrastearyl oxide, chromium (IV) tetraphenoxide, chromium (II) bis (acetate), chromium (II
I) Tris (acetate), chromium (II) bis (propionate), chromium (III) tris (propionate), chromium (III) tris (butyrate), chromium (II) bis (2-ethylhexanoate), chromium ( III) Tris (2-ethylhexanoate), chromium (II) bis (isooctanoate), chromium (II
I) tris (isooctaneate), chromium (III) tris (oxy-2-ethylhexanoate), chromium (III) tris (dichloroethylhexanoate),
Chromium (III) tris (neopentanoate), chromium (II) bis (neopentanoate), chromium (II
I) tris (laurate), chromium (II) bis (laurate), chromium (III) tris (stearate),
Chromium (II) bis (stearate), chromium (II
I) Tris (oleate), chromium (II) bis (oleate), chromium (III) tris (benzoate),
Chromium (II) bis (naphthenate), chromium (II
I) Tris (naphthenate), chromium (II) oxalate, chromium (II) bis (acetylacetonate),
Chromium (III) tris (acetylacetonate), chromium (III) tris (trifluoroacetylacetonate), chromium (III) tris (hexafluoroacetylacetonate), chromium (III) tris (2,
2,6,6-tetramethyl-3,5-heptanedionate), chromium (III) tris (1,3-butanedionate), chromium (III) tris (2-methyl-1,3
-Butane dionate), chromium (III) tris (benzoylacetonate), chromium (III) tris (acetyl acetate), chromium (III) tris (dimethylamide), chromium (III) tris (dicyclohexylamide), fluorinated Chromium monochromate, chromium fluoride, chromium chloride, chromium chloride, chromium bromide, chromium bromide, chromium iodide, chromium iodide, chromyl chloride, chromium perchlorate , Hydroxychromium dichloride,
Examples thereof include chromium nitrate and chromium sulfate.

Further, trichlorotrianiline chromium (III), dichlorobis (pyridine) chromium (I
I), dichlorobis (4-ethylpyridine) chromium (I
I), trichlorotripyridinechromium (III), trichlorotris (4-isopropylpyridine) chromium (I
II), trichlorotris (4-ethylpyridine) chromium (III), trichlorotris (4-phenylpyridine) chromium (III), trichloro (1,4,7-trimethyl-1,4,7-triazacyclononane) Chromium (III), dichlorodinitrosylbis (4-ethylpyridine) chromium (II), dichlorodinitrosylbis (triphenylphosphine oxide) chromium (II),
Dichlorobis (triphenylphosphine oxide) chromium (II), trichlorotris (triphenylphosphine) chromium (III), trichlorobis (tributylphosphine) chromium (III) dimer, trichlorotris (butylacetate) chromium (III), trichlorotris ( Ethyl acetate) chromium (III), trichlorotris (tetrahydrofuran) chromium (III),
Trichlorotris (dioxane) chromium (III), trichlorotris (iso-propanol) chromium (II)
I), trichlorotris (2-ethylhexanol) chromium (III), triphenyltris (tetrahydrofuran) chromium (III), chromium (III) tris (acetate) acetic anhydride adduct, hydridotricarbonyl (η-cyclopentane) Dienyl) chromium (III) and the like.

Of these, from the viewpoint of ease of handling and stability, a chromium carboxylate compound having a carboxylate group and a chromium β having a β-diketonate group.
-Diketonate compounds are preferably used. More preferably, chromium (III) tris (2-ethylhexanoate), chromium (III) tris (naphthenate),
Chromium (III) tris (acetylacetonate), chromium (III) tris (trifluoroacetylacetonate), and chromium (III) tris (2,2,6,6-tetramethyl-3,5-heptanedionate) Used. Further, the above chromium compounds can be used alone or in combination of two or more.

The alkyl metal compound used in the present invention is not particularly limited, but for example, the following general formula (3) R _p MX _q (3) (In the formula, p is 0 <p ≦ 3. , Q is 0 ≦ q <3, and p + q is 1 to 3. M represents lithium, magnesium, zinc, boron or aluminum, and R is at least selected from an alkyl group having 1 to 10 carbon atoms. 1
Or more, X represents at least one selected from the group consisting of a hydrogen atom, an alkoxy group, an aryl group and a halogen atom), or an aluminoxane is preferable.

In the general formula (3), the number of carbon atoms is 1 to 1.
The alkyl group of 0 is not particularly limited, and includes, for example, a methyl group, an ethyl group, a propyl group, a butyl group, a cyclohexyl group, an octyl group, and the like. Although it does not specifically limit as an alkoxy group, For example, a methoxy group, an ethoxy group, a butoxy group, a phenoxy group, etc. are mentioned. As an aryl group,
Although not particularly limited, for example, a phenyl group and the like can be mentioned. Although it does not specifically limit as a halogen atom, For example, fluorine, chlorine, bromine, or iodine is mentioned.

In the above general formula (3), M is A
1 and p and q are 1.5, respectively, AlR _1.5 X _1.5
Becomes Although such compounds do not exist in theory, they are usually conventionally expressed as sesqui-forms of Al ₂ R ₃ X ₃ , and these compounds are also included in the present invention.

Examples of the alkyl metal compound represented by the above general formula (3) include methyllithium, ethyllithium, propyllithium, n-butyllithium, s-butyllithium, t-butyllithium, diethylmagnesium, ethylbutylmagnesium. , Ethylchloromagnesium, ethylbromomagnesium, dimethylzinc, diethylzinc, dibutylzinc, trimethylborane, triethylborane, trimethylaluminum, triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, tricyclohexyl. Aluminum, dimethylethyl aluminum, diethyl aluminum hydride, diisobutyl aluminum hydride, diethyl aluminum ethoxide, diethyl Rumi bromide phenoxide, dicyclohexyl phenyl aluminum, ethyl aluminum ethoxy chloride, diethylaluminum chloride, diethylaluminum bromide, diisobutylaluminum chloride, dicyclohexyl aluminum chloride,
Examples include methylaluminum sesquichloride, ethylaluminum sesquichloride, butylaluminum sesquichloride, ethylaluminum dichloride, isobutylaluminum dichloride and the like.

The aluminoxane used in the present invention is a hydrolysis product obtained by reacting the above-mentioned alkylaluminum compound and water in a quantitative ratio within a certain range. The method of hydrolyzing the alkylaluminum compound is not particularly limited and can be synthesized by a known method. For example, (1) a method in which water is brought into contact with an alkyl aluminum compound as it is or a diluted solution in an organic solvent, (2) an alkyl aluminum compound and magnesium chloride · 6 hydrate, iron sulfate · 7 hydrate, copper sulfate · 5 water A method of reacting with water of crystallization of a metal salt such as a salt is employed. Specifically, it is disclosed in the above-mentioned JP-A-62-265237 and JP-A-62-148491. The molar ratio of the alkylaluminum compound and water during the hydrolysis is usually 1: 0.4 to 1: 1.2, preferably 1: 0.5.
˜1: 1.0.

Among these alkyl metal compounds, triethylaluminum and triisobutylaluminum are preferably used from the viewpoints of availability and activity. Not only can these alkyl metal compounds be used alone,
It is also possible to use a mixture of two or more. The amount of the alkyl metal compound used is usually 0.1 to 10,000 equivalents, preferably 3 to 1 mol, relative to 1 mol of the chromium compound.
The amount is 3,000 equivalents, more preferably 10 to 2,000 equivalents.

The chromium catalyst of the present invention can be prepared by bringing the above-mentioned chromium compound, alkyl metal compound and imide compound into contact with each other in a solvent. Although the contact method is not particularly limited, for example, a method of contacting a chromium compound, an alkyl metal compound and an imide compound in the presence of ethylene, which is a trimerization reaction raw material, to prepare a catalyst, and starting the trimerization reaction at the same time as the contact ( Hereinafter, referred to as a simultaneous catalyst preparation method), or a method of contacting with a chromium compound, an alkyl metal compound and an imide compound in advance to prepare a catalyst, and then contacting with ethylene to carry out a trimerization reaction (hereinafter referred to as a pre-catalyst preparation method). Referred to). Specifically, in the case of the simultaneous catalyst preparation method, (1) a chromium compound, an alkyl metal compound, an imide compound and ethylene are simultaneously and independently introduced into the reaction system, and (2) a chromium compound is added to a solution containing the alkyl metal compound. , (3) Introduce imide compound and ethylene, (3) Introduce alkyl metal compound and ethylene to solution containing chromium compound and imide compound, (4) Introduce chromium compound and ethylene to solution containing alkyl metal compound and imide compound The catalyst can be prepared by a method of introducing an alkyl metal compound, an imide compound and ethylene into a solution containing (5) a chromium compound. In the case of the pre-catalyst preparation method, (1) the alkyl metal compound is introduced into the solution containing the chromium compound and the imide compound, and (2) the chromium compound is introduced into the solution containing the alkyl metal compound and the imide compound. The catalyst can be prepared by a method of introducing a chromium compound and an imide compound into a solution containing an alkyl metal compound, and (4) introducing an imide compound and an alkyl metal compound into a solution containing a chromium compound.
The order of mixing these raw materials is not particularly limited.

The concentration of the chromium compound in preparing the catalyst system is not particularly limited, but is usually 0.001 to 100 mmol, preferably 0.01 to 10 mmol per liter of the solvent. used. The solvent used here is an aliphatic hydrocarbon and is not particularly limited, but for example, butane,
Saturated aliphatic hydrocarbons such as pentane, hexane, heptane, octane, isooctane, nonane, decane, cyclopentane, cyclohexane, methylcyclohexane, cyclooctane, decalin, and chlorination of methylene chloride, chloroform, carbon tetrachloride, dichloroethane, etc. Aliphatic hydrocarbons are mentioned. Further, the olefin itself as the reaction raw material or the reaction product, for example, unsaturated aliphatic hydrocarbons such as butene, 1-hexene, octene, decene, dodecene can also be used as a solvent. Of these, saturated aliphatic hydrocarbons are preferable from the viewpoint of activity and availability, and cyclohexane and heptane are more preferably used. These solvents can be used alone or in combination of two or more. Here, for the purpose of controlling the catalyst concentration at the time of preparing the catalyst, it may be concentrated or diluted as necessary.

The temperature at which the chromium compound, the alkyl metal compound and the imide compound are contacted is usually -100.
˜250 ° C., preferably 0˜200 ° C. The preparation time of the catalyst system is not particularly limited, and is usually 0 minutes to 24 hours, preferably 0 minutes to 2 hours. It is desirable that all operations for preparing the catalyst be performed while avoiding air and moisture. Further, it is preferable that the catalyst preparation raw material and the solvent are sufficiently dried.

According to the invention, the chromium compound prepared as described above, the catalyst system consisting of an alkyl metal compound and an imide compound, adding a halide represented further by the general formula _{R 'i M' j X '} k , Served as a chromium catalyst. Effects such as improvement of catalytic activity and suppression of by-product of polymer are recognized by the coexistence of halide.

The halide used in the present invention is not particularly limited, but for example, the following general formula (4) R ′ _i M ′ _j X ′ _k (4) (wherein i is 0 to 4) Is an integer of 0, j is an integer of 0 to 1, and k is an integer of 1 to 4. R'represents hydrogen or a hydrocarbon having 1 to 20 carbons, and M'is I.
Compounds represented by A, IIA, VIII, IIB, IIIB, IVB or VB group, and X ′ represents at least one or more selected from halogen atoms) are preferred.

Examples of the halide of the general formula (4) include chlorine, bromine, iodine, butyl chloride, amyl chloride, hexyl chloride, heptyl chloride, octyl chloride, nonyl chloride, desyl chloride, lauryl chloride, methyl bromide, propyl. Bromide, butyl bromide, amyl bromide, hexyl bromide, ethylhexyl bromide, nonyl bromide, cetyl bromide, dibromomethane, dichloroethane, dibromoethane, dichlorobutene, cyclohexyl bromide, chloroform, tetrachlorohydrocarbon, chlorobenzene, dichlorobenzene, bromobenzene, dibromobenzene. , Sodium chloride, potassium chloride, cesium chloride, magnesium chloride, zinc chloride, zinc bromide, zinc iodide, boron trichloride,
Boron tribromide, aluminum trichloride, aluminum tribromide, silicon tetrachloride, germanium tetrachloride, germanium tetrabromide, stannous chloride, stannous chloride, tin iodide, phosphorus trichloride, phosphorus pentachloride, tris Antimony chloride, antimony pentachloride, antimony tribromide, antimony trifluoride, antimony pentafluoride, dimethyl aluminum chloride, dimethyl aluminum bromide, dimethyl aluminum iodide, diethyl aluminum chloride, diethyl aluminum bromide, diethyl aluminum iodide, ethyl aluminum Dichloride, ethyl aluminum dibromide, ethyl aluminum diiodide, diisopropyl aluminum chloride, diisobutyl aluminum chloride, isobutyl aluminum dichloride, dihexyl alcohol Nium chloride, dicyclohexyl aluminum chloride, dioctyl aluminum chloride, methyl aluminum sesquichloride, ethyl aluminum sesquichloride, butyl aluminum sesquichloride, trimethylsilyl chloride, trimethylsilyl bromide, dimethylsilyl dichloride, methylsilyl trichloride, phenylsilyl trichloride, diphenylsilyl dichloride, Examples include methyldichlorosilane, tributyltin chloride, dibutyltin dichloride, butyltin trichloride, triphenyltin chloride, diphenyltin dichloride, and phenyltin trichloride. Of these, chlorinated products are preferably used from the viewpoint of ease of handling and economy, and more preferably, diethyl aluminum chloride, ethyl aluminum dichloride, stannic chloride, germanium tetrachloride, and antimony pentachloride are used. These halides can be used alone, or two or more of them can be used in combination.

The halide may be added at the time of preparing the chromium catalyst composed of the chromium compound, the alkyl metal compound and the imide compound, or may be added directly to the ethylene trimerization reaction system. The amount of this halide used is usually 0.2 with respect to 1 mol of the chromium compound.
To 5,000 equivalents, preferably 0.5 to 2,000
It is 0 equivalent, more preferably 1 to 1,000 equivalents.

According to the present invention, a Lewis acid is further added to the catalyst system composed of the chromium compound, the alkyl metal compound and the imide compound prepared as described above to serve as a catalyst for low polymerization of olefins. The effect of improving the catalytic activity is recognized by the coexistence of the Lewis acid.

The Lewis acid used in the present invention is not particularly limited, but for example, the following general formula (5) M (Ar) _l (5) (wherein, l is an integer of 2 to 4) , M is Periodic Table II
A compound represented by group B, IIIB or IVB, and Ar represents at least one selected from aryl groups).

Examples of the Lewis acid represented by the general formula (5) include tris (2-fluorophenyl) boron, tris (3-fluorophenyl) boron, tris (4-fluorophenyl) boron and tris (2,4-difluoro). Phenyl) boron, tris (2,5-difluorophenyl)
Boron, tris (2,6-difluorophenyl) boron, tris (2,4,5-trifluorophenyl) boron, tris (2,4,6-trifluorophenyl) boron, tris (pentafluorophenyl) boron, bis (Pentafluorophenyl) zinc, tris (pentafluorophenyl) aluminum, tetrakis (pentafluorophenyl) germanium, tetrakis (pentafluorophenyl) tin, tris (4-trifluoromethylphenyl) boron, and the like. Of these, tris (pentafluorophenyl) boron is preferably used in terms of availability and activity. These Lewis acids can be used not only alone but also as a mixture of two or more kinds. It is also possible to use a mixture with the above halide.

The Lewis acid may be added at the time of preparing the catalyst comprising the chromium compound, the alkyl metal compound and the imide compound, or may be added directly to the low polymerization reaction system. The amount of the Lewis acid used is usually 0.1 to 2,000 equivalents, preferably 0.5 to 1,500 equivalents, and more preferably 1 to 1 mol with respect to 1 mol of the chromium compound.
It is 1,000 equivalents. When the amount of the Lewis acid used is less than 0.1 equivalent to 1 mol of the chromium compound, low polymerization reaction activity cannot be sufficiently obtained. On the other hand, if the amount used exceeds 2,000 equivalents relative to 1 mol of the chromium compound, the catalytic activity will not increase and it is economically undesirable.

According to the present invention, in the reaction for trimerizing ethylene in the presence of a chromium catalyst composed of a chromium compound, an alkyl metal compound and an imide compound, the number of carbon atoms is 1 to 6
Alkyl group, halogen atom-substituted or unsubstituted aromatic hydrocarbon is added to the reaction system.

The above-mentioned aromatic hydrocarbon is not particularly limited, but for example, toluene, ethylbenzene, cumene, butylbenzene, xylene, cymene, diisopropylbenzene, dibutylbenzene, pentamethylbenzene, trifluoromethylbenzene, etc. Alkyl group-substituted monocyclic aromatic hydrocarbons, alkyl group-substituted polycyclic aromatic hydrocarbons such as naphthalene, methylnaphthalene, and dimethylnaphthalene, and halogen atom-substituted hydrocarbons such as chlorobenzene, dichlorobenzene, and bromobenzene. An unsubstituted benzene is mentioned. Of these, alkyl-substituted monocyclic aromatic hydrocarbons are preferable, and toluene and butylbenzene are more preferable, from the viewpoint of safety and availability. Further, the above aromatic hydrocarbons can be used not only individually but also as a mixture of two or more kinds.

The timing of addition of the aromatic hydrocarbon is not particularly limited, but it may be added in advance when the chromium catalyst is prepared, or may be added directly to the ethylene trimerization reaction system. Here, when an aromatic hydrocarbon is added in the step of preparing the catalyst by the above-mentioned pre-catalyst preparation method, the catalytic activity may be remarkably reduced. It is preferably added directly to the system. The amount of aromatic hydrocarbon used is 0.01 to 50% by volume, preferably 0.05 to 20% by volume, more preferably 0.1 to 50% by volume of the charged solution.
It is 10% by volume. When the amount of the aromatic hydrocarbon used is more than 50% by volume of the charged solution, the catalytic activity tends to decrease, which is not economically preferable. Here, the charged solution represents a total amount of a trimerization reaction solution during the trimerization reaction of ethylene, that is, a solution of an aliphatic hydrocarbon used as a solvent and a solution of an aromatic hydrocarbon used in the present invention.

The trimerization reaction of ethylene is carried out using the chromium catalyst thus prepared. In the present invention, the amount of the chromium catalyst used is not particularly limited, but it is usually diluted with the above solvent, and the chromium compound is 0.001 micromol to 100 millimol, preferably 0.01 micromol to 1 liter of the trimerization reaction liquid. Used at a concentration of 10 mmol. At a catalyst concentration lower than this, sufficient 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.

The temperature of the trimerization reaction in the present invention is usually -100 to 250 ° C, preferably 0 to 200 ° C.
It is. The reaction pressure is not particularly limited as long as the trimerization reaction system is an ethylene atmosphere, but is usually 0 to 3 in absolute pressure.
000 kg / cm ² , preferably 0-300 kg
/ Cm ² . The reaction time depends on the temperature and the pressure and cannot be determined unconditionally, but is usually 5 seconds to 6 hours. In addition, ethylene may be continuously supplied so as to maintain the above pressure, or may be sealed at the above pressure at the start of the reaction and reacted. The raw material gas ethylene is
A gas inert to the reaction, such as nitrogen, argon or helium, may be contained. In addition, it is desirable to perform all the operations of the trimerization reaction while avoiding air and water. Further, it is preferable that ethylene is sufficiently dried.

This reaction can be carried out batchwise, semi-continuously or continuously. After completion of the trimerization reaction, the reaction is stopped by adding a polymerization deactivator such as water, alcohol, or sodium hydroxide aqueous solution to the reaction solution. The deactivated waste chromium catalyst is removed by a known deashing treatment method, for example, extraction with water or an aqueous alkaline solution, and then the produced 1-hexene is separated from the reaction solution by a known extraction method or distillation method. The by-produced polymer is separated and removed at the outlet of the reaction solution as a residue in a known centrifugation method or distillation separation of the produced 1-hexene.

[0044]

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 Inner volume 3 equipped with thermometer, catalyst feed tube and stirring device
A 00 ml stainless steel pressure resistant reactor was heated and vacuum dried at 90 ° C., and then sufficiently replaced with nitrogen gas. 0.885m
mol / L of chromium (III) tris (2-ethylhexanoate) / cyclohexane solution 1.1 ml, 0.6
0 mmol / L maleimide / cyclohexane solution 10
0 ml and 5.3 ml of dried toluene were charged on the barrel side of the reaction vessel and sufficiently replaced with ethylene. On the other hand, in a catalyst feed tube, a triethylaluminum / cyclohexane solution (2.3 ml, 0.188 mol / L), 73.9 mmol
/ L of diethylaluminum chloride / cyclohexane solution (2.2 ml) was charged.

After heating the reaction vessel to 120 ° C. and adjusting the stirring speed to 1,000 rpm, ethylene was introduced into the catalyst feed tube, and a mixed solution of triethylaluminum and diethylaluminum chloride was introduced into the reaction vessel body side by ethylene pressure. Then, the trimerization reaction of ethylene was started. Ethylene gas was blown in so that the absolute pressure in the reaction vessel became 40 kg / cm ^2, and thereafter, introduction was continued so as to maintain the pressure, and a reaction was carried out for 30 minutes while maintaining these reaction conditions. After 30 minutes, the reaction was stopped by injecting an aqueous sodium hydroxide solution into the reaction vessel with nitrogen to deactivate the catalyst.

The reaction vessel was cooled to room temperature and then depressurized. The products contained in the reaction solution and the recovered gas were analyzed by gas chromatography. The solid content contained in the reaction solution was filtered using a filter paper, air-dried, and then dried under reduced pressure (1 mmHg, 100 ° C.), and the weight was measured. The results are shown in Table 1.

Example 2 The reaction was carried out in the same manner as in Example 1 except that the amount of toluene was changed to 0.11 ml. The results are shown in Table 1.

Example 3 The reaction was carried out in the same manner as in Example 1 except that the amount of toluene was changed to 11.6 ml. The results are shown in Table 1.

Example 4 1.6 ml of t-butylbenzene instead of toluene
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 5 A reaction was carried out in the same manner as in Example 1 except that 4.5 ml of benzene was used instead of toluene. The results are shown in Table 1.

Example 6 A reaction was carried out in the same manner as in Example 1 except that 0.10 ml of chlorobenzene was used instead of toluene.
The results are shown in Table 1.

Example 7 Maleimide (5.8 mg, 60 mg) was added to a 100 ml Schlenk tube.
μmol) was weighed and dissolved in 100 ml of dry cyclohexane to obtain 0.885 mmol / L of chromium (III).
1.1 ml of a tris (2-ethylhexanoate) / cyclohexane solution was added and mixed. 0.188 mol / L
Triethylaluminum / cyclohexane solution 2.3
ml, 73.9 mmol / L diethylaluminum chloride / cyclohexane solution (2.2 ml) were added, and the mixture was stirred at room temperature for 1 hour to prepare a catalyst solution.

A pressure-resistant stainless steel reactor having an internal volume of 300 ml equipped with a thermometer, a catalyst feed tube and a stirrer was heated and vacuum dried at 90 ° C., and then sufficiently replaced with nitrogen gas. The total amount of the catalyst solution was charged into a container, and 1.1 ml of toluene was further added. Stir speed 1,000 rpm
After heating the reaction container to 120 ° C., ethylene gas was blown into the reaction container so that the absolute pressure in the reaction container became 40 kg / cm ^2, and the trimerization reaction of ethylene was started. Thereafter, the introduction was continued so as to maintain the pressure, and the reaction was carried out for 30 minutes while maintaining these reaction conditions. After 30 minutes, the reaction was stopped by injecting an aqueous sodium hydroxide solution into the reaction vessel with nitrogen to deactivate the catalyst.

The reactor was cooled to room temperature and then depressurized. The products contained in the reaction solution and the recovered gas were analyzed by gas chromatography. The solid content contained in the reaction solution was filtered using a filter paper, air-dried, and then dried under reduced pressure (1 mmHg, 100 ° C.), and the weight was measured. The results are shown in Table 1.

Example 8 A pressure-resistant stainless steel reactor having an internal volume of 300 ml equipped with a thermometer, a catalyst feed pipe tail and a stirrer was heated and vacuum-dried at 90 ° C., and then sufficiently replaced with nitrogen gas. 0.189
3.2 ml of a mol / L triethylaluminum / cyclohexane solution and 25 ml of dried cyclohexane were charged on the barrel side of the reaction vessel and sufficiently replaced with ethylene. on the other hand,
9.80 mmol / L of chromium (II
I) 2.1 ml of tris (2-ethylhexanoate) / cyclohexane solution and 80 ml of a 0.750 mmol / L maleimide / cyclohexane solution and 5.3 ml of dry toluene were charged.

After heating the reaction vessel to 80 ° C. and adjusting the stirring speed to 1,000 rpm, ethylene was introduced into the catalyst feed tube, and the mixed solution of the chromium compound and the maleimide was introduced into the reaction vessel barrel side by ethylene pressure. The trimerization reaction of ethylene was started. Absolute pressure in the reaction vessel is 40 kg /
Ethylene gas was blown in so that the pressure became cm ^2, and thereafter introduction was continued so as to maintain the pressure, and the reaction was carried out for 30 minutes while maintaining these reaction conditions. After 30 minutes, the reaction was stopped by injecting an aqueous sodium hydroxide solution into the reaction vessel with nitrogen to deactivate the catalyst.

The reaction vessel was cooled to room temperature and then depressurized. The products contained in the reaction solution and the recovered gas were analyzed by gas chromatography. The solid content contained in the reaction solution was filtered using a filter paper, air-dried, and then dried under reduced pressure (1 mmHg, 100 ° C.), and the weight was measured. The results are shown in Table 1.

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

Comparative Example 2 The reaction was carried out in the same manner as in Example 8 except that toluene was not added. The results are shown in Table 1.

[0060]

[Table 1]

[0061]

INDUSTRIAL APPLICABILITY According to the present invention, aromatic hydrocarbons are reacted in the reaction of trimerizing ethylene in the presence of a chromium catalyst consisting of a chromium compound, an alkyl metal compound and a highly stable and easily handled imide compound. When added to the system, it is highly active, highly selective, and with extremely high purity.
Hexene can be obtained.

[0062]

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location // C07B 61/00 300 C07B 61/00 300 C08F 10/02 C08F 10/02

Claims (5)

[Claims] 1. An aliphatic hydrocarbon is used as a solvent in a reaction for trimerizing ethylene in the presence of a chromium catalyst composed of a chromium compound, an alkyl metal compound and an imide compound, and an alkyl group having 1 to 6 carbon atoms and a halogen. Atom-substituted or non-substituted aromatic hydrocarbon was added to the charged solution at 0.0
A method for producing 1-hexene, which comprises adding 1 to 50% by volume to a reaction system. 2. An imide compound represented by the following general formula (1): (In the formula, d is an integer of 1 to 4. M represents hydrogen or a substituent-containing or unsubstituted metal element of Group IA, IIA, IB, IIB, IIIB or IVB of the periodic table.
¹ and R ² are each hydrogen, an alkyl group having 1 to 10 carbon atoms, a halogen atom, an aryl group, or R ¹ and R ² are carbon-
The compound represented by at least one selected from the group consisting of cyclic substituents bonded by a carbon bond)), The method for producing 1-hexene according to claim 1. 3. A chromium compound represented by the following general formula (2) CrA _m B _n (2) (wherein m is an integer of 1 to 6 and n is an integer of 0 to 4. A is a carbon number. 1-20 alkyl groups, aryl groups, arenes, alkoxy groups, carboxylate groups, β
-Diketonate groups, β-ketoester groups and amide groups,
Represents at least one selected from the group consisting of a halogen atom, a hydroxyl group, a nitrate group, a sulfate group, a perchlorate group, carbonyl and oxygen, and B represents a nitrogen-containing compound, a phosphorus-containing compound, an arsenic-containing compound, an antimony-containing compound. Compound,
A compound represented by at least one selected from the group consisting of an oxygen-containing compound and a sulfur-containing compound), the method for producing 1-hexene according to claim 1 or 2. 4. An alkyl metal compound having the following general formula (3) R _p MX _q (3) (wherein p is 0 <p ≦ 3, q is 0 ≦ q <3, and p + q is 1 to 3. M represents lithium, magnesium, zinc, boron or aluminum, and R is at least 1 selected from an alkyl group having 1 to 10 carbon atoms.
1 or more, and X represents at least one selected from the group consisting of hydrogen atom, alkoxy group, aryl group and halogen atom), or an aluminoxane. 1 described in 3
Method for producing hexene. 5. The chromium catalyst according to claim 1, further comprising the following general formula (4) R ′ _i M ′ _j X ′ _k (4) (wherein i is 0 to 4). It is an integer, j is an integer of 0 to 1, and k is an integer of 1 to 4. R'represents hydrogen or a hydrocarbon having 1 to 20 carbon atoms, and M'is I of the periodic table.
A, IIA, VIII, IIB, IIIB, IVB or VB group element, and X ′ represents at least one or more selected from halogen atoms). Method for producing hexene.