JP2010189297A - Method for producing 1-hexene and/or 1-octene by trimerizing and/or tetramerizing ethylene - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method efficiently synthesizing 1-hexene and/or 1-octene with high selectivity. <P>SOLUTION: The method for producing 1-hexene and/or 1-octene comprises trimerizing and/or tetramerizing ethylene in the presence of a compound represented by formula (1) (wherein R<SP>1</SP>, R<SP>2</SP>, R<SP>3</SP>, and R<SP>4</SP>are each hydrogen or the like; R<SP>5</SP>and R<SP>6</SP>are each a 1-12C hydrocarbon group or the like; and n is an integer of 1-6), a chromium compound, and an organoaluminum compound at a temperature of 30-200°C under pressure of 100 kPa-20 MPa. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a process for producing 1-hexene and / or 1-octene by trimerization and / or tetramerization of ethylene.

  1-hexene and 1-octene are very important compounds as comonomers of linear low density polyethylene. Its production is mainly carried out by low polymerization of ethylene. In such a low polymerization method, the obtained product has a distribution, and it is impossible to selectively obtain only a desired compound.

  Therefore, synthetic studies on 1-hexene / 1-octene by selective trimerization / tetramerization of ethylene have been conducted. In Sasol, 1-hexene synthesis has been energetically studied and reported by Morgan et al. (See Non-Patent Document 1).

  In addition, the synthesis of 1-hexene using PNP or SNS ligands has been reported by Hanson, Overett, McGuiness et al. Of Sasol (see Non-Patent Documents 2, 3, and 4).

  CPChem uses a catalyst system consisting of a chromium compound, pyrrole, and an organoaluminum compound, and operates a 1-hexene plant based on trimerization of ethylene on a scale of 47,000 tons in Qatar.

  Furthermore, a low polymerization method of ethylene using a chromium compound and an imide compound (see Patent Document 1), and a trimerization method of ethylene using a chromium complex and a tripodal ligand in the presence of hydrogen (see Patent Document 2). It has been known. Patent Document 2 exemplifies trispyrazolylmethane as a tripodal ligand, and clearly shows the use of an aluminumoxy compound typified by methylaluminoxane.

JP 08-59732 A JP 2002-205960 A

J. et al. Organomet. Chem. , 2004, 689, 3641 Organometallics, 2007, 26, 2782 J. et al. Am. Chem. Soc. 2005, 127, 10723 J. et al. Am. Chem. Soc. , 2003, 125, 5272

  As described above, there are many reports on the synthesis of 1-hexene and 1-octene from ethylene. From the viewpoint of improving the selectivity of 1-hexene and 1-octene and suppressing the formation of polyethylene and wax. There is still room for improvement before it can be put to practical use. In addition, if the production of polyethylene or the like cannot be suppressed, the selectivity of 1-hexene and 1-octene which are the target products becomes insufficient, and depending on the production location, the apparatus may be blocked and the operation may be stopped. There is.

  In addition, when chromium is used as the catalyst, the catalyst is mostly disposable for each batch. For this reason, it is extremely important to improve the activity of the catalyst from the viewpoints of improving the economy and reducing chromium waste.

  Furthermore, when the pyrrole ligand introduced above is used, there is a problem in the stability of the catalyst. In particular, pyrrole is easily oxidized by oxygen in the air, resulting in a decrease in catalyst efficiency and a decrease in 1-hexene selectivity. Further, pyrrole oxide is intensely colored, and there is a concern that the color tone of the target product is deteriorated.

  In addition, trispyrazolylmethanes disclosed in Patent Document 2 are difficult to synthesize, and methylaluminoxane is particularly expensive. In the example illustrated here, the polymer is generated twice or more than the oligomer, and the 1-olefin selectivity is not as high as about 90%.

  The present invention has been made in view of such circumstances, and its purpose is to produce polyethylene and wax in the production of 1-hexene and / or 1-octene by trimerization and / or tetramerization of ethylene. It is an object of the present invention to provide a method capable of efficiently synthesizing 1-hexene and / or 1-octene with high selectivity while sufficiently suppressing the above. In addition, another object of the present invention is to have high activity, no coloration on the product, and stable, to improve the selectivity of 1-hexene and / or 1-octene and to suppress the formation of polymer. Is to provide a suitable catalyst.

［式中、Ｒ^１、Ｒ^２、Ｒ^３およびＲ^４は各々独立に水素原子または炭素数１〜１２の炭化水素基を示し、Ｒ^１とＲ^２、Ｒ^２とＲ^３、Ｒ^３とＲ^４とで環を形成していてもよく、Ｒ^５およびＲ^６は各々独立に水素原子または炭素数１〜１２の炭化水素基を示し、ｎは１〜６の整数を示す。］ In order to solve the above-mentioned problems, the present invention provides ethylene under the conditions of a temperature of 30 to 200 ° C. and a pressure of 100 kPa to 20 MPa in the presence of a compound represented by the following general formula (1), a chromium compound and an organoaluminum compound. A method for producing 1-hexene and / or 1-octene is provided, characterized in that 1-hexene and / or 1-octene is obtained by trimerization and / or tetramerization.

[Wherein, R ¹ , R ² , R ³ and R ⁴ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, R ¹ and R ² , R ² and R ³ , R ³ and R ⁴ may form a ring, R ⁵ and R ⁶ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and n represents an integer of 1 to 6. ]

  In the present invention, a complex of the compound represented by the general formula (1) and the chromium compound can be preferably used as the compound represented by the general formula (1) and the chromium compound.

In addition, when R ⁵ and R ⁶ in the general formula (1) are aromatic substituents, a contact product of the compound represented by the general formula (1) and the chromium compound, or the general formula (1) It is preferable to prepare a catalyst by bringing a complex of the compound represented by and a chromium compound into contact with an organoaluminum compound and a solvent used as necessary, and then bringing the catalyst into contact with the ethylene.

In addition, when R ⁵ and R ⁶ in the general formula (1) are alkyl groups, a contact product between the compound represented by the general formula (1) and the chromium compound, or the general formula (1) It is preferable to mix a complex of a compound and a chromium compound with a mixture of an organoaluminum compound, ethylene and a solvent used as necessary.

  Moreover, it is preferable that the molar ratio of an organoaluminum compound and a chromium compound is 0.01-100,000 by Al / Cr ratio.

  According to the present invention, when 1-hexene and / or 1-octene is produced by trimerization and / or tetramerization of ethylene, the production of polyethylene and wax is sufficiently suppressed, while 1-hexene and / or 1-octene is sufficiently suppressed. A method capable of efficiently synthesizing octene with high selectivity can be provided.

  Hereinafter, preferred embodiments of the present invention will be described in detail.

［式中、Ｒ^１、Ｒ^２、Ｒ^３およびＲ^４は各々独立に水素原子または炭素数１〜１２の炭化水素基を示し、Ｒ^１とＲ^２、Ｒ^２とＲ^３、Ｒ^３とＲ^４とで環を形成していてもよく、Ｒ^５およびＲ^６は各々独立に水素原子または炭素数１〜１２の炭化水素基を示し、ｎは１〜６の整数を示す。］ The method for producing 1-hexene and / or 1-octene of the present invention is carried out at a temperature of 30 to 200 ° C. and a pressure of 100 kPa to 20 MPa in the presence of a compound represented by the following general formula (1), a chromium compound and an organoaluminum compound. Under the conditions, trimerization and / or tetramerization of ethylene is performed to obtain 1-hexene and / or 1-octene.

[Wherein, R ¹ , R ² , R ³ and R ⁴ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, R ¹ and R ² , R ² and R ³ , R ³ and R ⁴ may form a ring, R ⁵ and R ⁶ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and n represents an integer of 1 to 6. ]

  In the present invention, the compound represented by the general formula (1), the chromium compound and the organoaluminum compound serve as a catalyst.

First, the compound represented by the general formula (1) will be described. In the general formula (1), as R ^{1 to} R ⁴ , specifically, a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tertiary butyl group, a pentyl group, Examples include isopentyl group, neopentyl group, cyclopentyl group, hexyl group, isohexyl group, cyclohexyl group, phenyl group, tolyl group, xylyl group, and naphthyl group. R ¹ and R ² , R ² and R ³ , R ³ and R ⁴ may form a ring. As R ^{1 to} R ⁴ , hydrogen is particularly preferable. Examples of forming a ring include quinoline and isoquinoline. In the case of quinoline, R ¹ and R ² form a ring, and in the case of isoquinoline, R ² and R ³ or R ³ and R ⁴ form a ring.

  N in General formula (1) is an integer of 1-6, Preferably it is an integer of 1-5, More preferably, it is 1-2.

Specific examples of R ⁵ and R ⁶ in the general formula (1) include a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tertiary butyl group, a pentyl group, and isopentyl. Group, neopentyl group, cyclopentyl group, hexyl group, isohexyl group, cyclohexyl group, phenyl group, tolyl group, xylyl group, naphthyl group and the like.

  Preferable examples of the compound represented by the general formula (1) include 2-methoxyloyl (diphenylphosphino) pyridine, 2-ethoxyloyl (diphenylphosphino) pyridine, 2-methoxyloyl (dio-tolylphosphino) pyridine. 2-ethoxyloyl (dio-tolylphosphino) pyridine, 2-methoxyloyl (dim-tolylphosphino) pyridine, 2-ethoxyloyl (dim-tolylphosphino) pyridine, 2-methoxyloyl (di-p-tolylphosphino) pyridine, 2 -Ethoxyloyl (di-p-tolylphosphino) pyridine, di2-methoxyloyl (dihexylphosphino) pyridine, 2-ethoxyloyl (dihexylphosphino) pyridine, 2-methoxyloyl (cyclohexylphosphino) pyridine, 2-ethoxyloyl ( The Chlohexylphosphino) pyridine, 2-methoxyloyl (ditertiarybutylphosphino) pyridine, 2-ethoxyloyl (ditertiarybutylphosphino) pyridine, 2-methoxyloyl (diisobutylphosphino) pyridine, 2-ethoxyroyl (diisobutyl) Phosphino) pyridine, 2-methoxyloyl (dipropylphosphino) pyridine, 2-ethoxyloyl (dipropylphosphino) pyridine, 2-methoxyloyl (diisopropylphosphino) pyridine, 2-ethoxyloyl (diisopropylphosphino) pyridine 2-methoxyloyl (diethylphosphino) pyridine, 2-ethoxyloyl (diethylphosphino) pyridine, 2-methoxyloyl (dimethylphosphino) pyridine, 2-ethoxyloyl (dimethylphosphine) I Roh) such as pyridine, and the like.

  The compound represented by the general formula (1) is more stable than pyrroles, and a complex formed from a metal salt or a metal complex described later is also stable, and 1-hexene and / or 1- High catalytic activity with excellent octene selectivity.

  In addition, as the chromium compound used in the present invention, salts having a trivalent cation are preferably used. Specifically, chromium chloride (III), chromium bromide (III), chromium iodide (III), chromium acetate (III), chromium acetylacetonate (III), chromium naphthenate (III), chromium nitrate (III ), Chromium (III) sulfate, chromium (III) oxide, and chromium (III) 2-ethylhexanoate.

  Further, a chromium complex is also preferably used, and specific examples include benzene chromium tricarbonyl (0), bisbenzene chromium (0), and chromium chloride (III) thf complex.

Moreover, as an organoaluminum compound used by this invention, the compound represented by following General formula (2) is suitable.
R _3-m AlX _m (2)
[In Formula (2), R shows a C1-C6 alkyl group, X shows a halogen atom, and m shows the integer of 0-2. ]

  Specific examples of the alkyl group having 1 to 6 carbon atoms represented by R include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tertiary butyl, pentyl, isopentyl, and hexyl. Group, phenyl group and the like. When 3-m is 2 or 3, the plurality of Rs present in one molecule may be the same as or different from each other.

  Examples of the halogen atom represented by X include fluorine, chlorine, bromine and iodine. When m is 2, the two halogen atoms present in the molecule may be the same as or different from each other.

  Preferred examples of the organoaluminum compound used in the present invention include trimethylaluminum, triethylaluminum, tripropylaluminum, triisopropylaluminum, tributylaluminum, triisobutylaluminum, tripentylaluminum, trihexylaluminum, triphenylaluminum, dimethylaluminum. Chloride, diethylaluminum chloride, dipropylaluminum chloride, dibutylaluminum chloride, dipentylaluminum chloride, dihexylaluminum chloride, methylaluminum dichloride, ethylaluminum dichloride, propylaluminum dichloride, butylaluminum dichloride, pentylaluminum dichloride, hexyl Such Rumi pyridinium dichloride and the like. These may be used alone or in a mixture of two or more.

  Also, ethylaluminum sesquichloride can be used, and an aluminumoxy compound typified by methylaluminoxane can also be used.

  In the catalyst according to the present invention, when the molar ratio (Al / Cr ratio) between the organoaluminum compound and the chromium compound is within a predetermined range, further improvement in catalytic activity and workability can be achieved. Specifically, Al / Cr = 0.01 to 100,000 is preferable, Al / Cr = 0.1 to 50,000 is more preferable, and Al / Cr = 0.1 to 30,000 is more preferable. . If the Al / Cr ratio is less than the lower limit, the reaction tends to be difficult to proceed, such being undesirable. Further, when the Al / Cr ratio exceeds the upper limit, an aluminum hydroxide gel is generated during post-reaction treatment, particularly when the organoaluminum compound is inactivated by water, and the handling tends to be troublesome. Absent.

  Reaction of selective trimerization and / or tetramerization of ethylene by contacting the compound represented by the above general formula (1), chromium compound, organoaluminum compound, ethylene, or a solvent used as necessary. Active species are formed. There is no particular limitation on the contact order.

  For example, the compound represented by the general formula (1), the chromium compound and the organoaluminum compound may be subjected to the reaction alone, or the components may be dissolved in an organic solvent in advance and mixed to prepare the catalyst. The catalyst prepared and obtained may be subjected to the reaction.

  As the organic solvent used for preparing the catalyst, benzene, toluene, xylene, hexane, cyclohexane, methylcyclohexane, tetrahydrofuran, diethyl ether, dichloromethane, chloroform and the like are suitable.

  The catalyst thus prepared can be subjected to the reaction in the form of a catalyst solution. Moreover, it can carry | support for support | carriers, such as a silica, and can use for reaction.

  In addition, the compound represented by the general formula (1) and the chromium compound can be subjected to a reaction after contacting them in advance in a solvent or in the absence of a solvent. In that case, a complex of the compound represented by the general formula (1) and the chromium compound may be isolated and the complex may be subjected to the reaction.

  When the compound represented by the general formula (1) and the chromium compound are contacted in advance and then subjected to the reaction, or when a complex of the compound represented by the general formula (1) and the chromium compound is used, The contact order of the components, ie the organoaluminum compound, ethylene and the solvent used as required, is arbitrary.

In addition, when the compound represented by the general formula (1) and R ⁵ and R ⁶ are aromatic substituents is contacted with a chromium compound in advance or when a complex of both is used, the contact product or complex is Furthermore, it is preferable to contact ethylene last, after making it a catalyst by making it contact with the organoaluminum compound and the solvent used as needed. By setting it as such a form, production | generation of heavy parts, such as polyethylene and a wax, can be suppressed more reliably, and 1-hexene selectivity and 1-octene selectivity can be improved further.

Further, when a compound represented by the general formula (1) and R ⁵ and R ⁶ are alkyl groups is contacted with a chromium compound in advance or when a complex of both is used, an organoaluminum compound, ethylene, and as necessary It is preferable to mix the contact product or complex with a mixture of solvents used accordingly. By setting it as such a form, production | generation of heavy parts, such as polyethylene and a wax, can be suppressed more reliably, and 1-hexene selectivity and 1-octene selectivity can be improved further.

  Regarding the reaction conditions for the trimerization and / or tetramerization of ethylene in the presence of the compound represented by the general formula (1), the chromium compound and the organoaluminum compound, the temperature is 30 to 200 ° C., and the pressure is 100 kPa to It is important that the pressure is 20 MPa. When the temperature is lower than 30 ° C., the conversion rate from ethylene to 1-hexene and / or 1-octene decreases. On the other hand, when the temperature exceeds 200 ° C., decomposition of the catalyst components and increase in the amount of ethylene due to thermal reaction occur. It becomes easy. In addition, when the pressure is less than 100 kPa, the reaction is difficult to proceed. On the other hand, when the pressure exceeds 20 MPa, excessive production facilities are required. For the same reason, the temperature is preferably 50 to 190 ° C, more preferably 60 to 180 ° C. The pressure is preferably 150 kPa to 19 MPa, more preferably 200 kPa to 18 MPa.

  EXAMPLES Hereinafter, although this invention is demonstrated further more concretely based on an Example and a comparative example, this invention is not restrict | limited to a following example at all.

(Complex synthesis example 1)
Under a nitrogen atmosphere, 2-pyridinomethanol (14 mmol) and triethylamine (42.5 mmol) were dissolved in THF (30 ml) and cooled to -78 ° C. To this solution maintained at −78 ° C., diphenylchlorophosphine (14 mmol) was added and stirred at −78 ° C. for 2 hours. Thereafter, the temperature was raised to room temperature, and the reaction solution was concentrated under reduced pressure. Diethyl ether was added to the concentrate, and the ammonium salt that was insoluble was removed by filtration. By concentrating the ether-soluble component, 2-methoxyloyl (diphenylphosphino) pyridine was obtained in a yield of 83 mol%. In addition, 2-methoxyloyl (diphenorphosphino) pyridine was stored for one week in a nitrogen atmosphere, but no change was visually observed.
The 2-methoxyloyl (diphenylphosphino) pyridine (1 mmol) thus obtained was dissolved in dichloromethane (4 ml) under a nitrogen atmosphere, and a dichloromethane solution (7 ml) of chromium chloride (III) THF complex (1 mmol) was obtained. Added over 10 minutes. After completion of the reaction, dichloromethane was distilled off under reduced pressure to obtain a chromium (III) chloride · 2-methoxyloyl (diphenylphosphino) pyridine complex in a yield of 76 mol%. Elemental analysis values of the complex thus obtained were C 41.09% (47.87%), H 4.13% (3.57%), N 3.16% (3.10%). there were. The values in parentheses are calculated values.

(Complex synthesis example 2)
Except that ditertiarybutylchlorophosphine was used instead of diphenylchlorophosphine, the same procedure as in Complex Synthesis Example 1 was repeated, except that 2-methoxyloyl (ditertiarybutylphosphino) pyridine and chromium (III) chloride-2-methoxyloyl ( Ditertiary butylphosphino) pyridine complex was synthesized.
The yield of 2-methoxyloyl (ditertiary butylphosphino) pyridine was 87%, and the yield of chromium (III) chloride · 2-methoxyloyl (ditertiarybutylphosphino) pyridine complex was 76 mol%.
2-Methoxyloyl (ditertiary butylphosphino) pyridine was stored for one week under a nitrogen atmosphere, but no change was observed visually.
The elemental analysis values of the complex were C 39.68% (40.85%), H 4.32% (5.88%), and N 3.54% (3.40%). The values in parentheses are calculated values.

Example 1
Chromium (III) chloride 2-methoxyloyl (diphenylphosphino) pyridine complex (10 μmol), triethylaluminum (0.1 mmol), diethylaluminum chloride (0.1 mmol), ethylaluminum chloride (0.1 mmol) in toluene (30 ml) ) And introduced into a 100 ml autoclave. After raising the temperature to 100 ° C., 6 MPa of ethylene was introduced. After 20 minutes, the apparatus was cooled and the product was analyzed by gas chromatography. As a result, it was confirmed that only C6 compound and C8 compound were produced. The C6 selectivity is 76 mol% (1-hexene selectivity 99%), the C8 selectivity is 24 mol% (1-octene selectivity 99%), and the catalyst efficiency of the C6 compound and the C8 compound is 300 C′2 mol / Cr mol h. “C6 selectivity” means the selectivity of all C6 compounds including 1-hexene, and “1-hexene selectivity” means the proportion of 1-hexene in the C6 compounds. Further, “C8 selectivity” means the selectivity of all C8 compounds including 1-octene, and “1-octene selectivity” means the proportion of 1-octene in the C8 compounds (see the following implementations). The same applies to the examples and comparative examples.)
100 ml of acidic methanol was added to the reaction product. The precipitate was filtered through a pre-weighted filter paper, washed with methanol, dried at 40 ° C. under reduced pressure, and the weight of the filter paper was measured. There was no change in the weight of the filter paper.
In addition, said analysis was performed by GC analysis using GL Sciences Inc. GC353B. Various conditions are as follows (the same applies to the following examples and comparative examples).
Detector and temperature: FID, 220 ° C
Make-up gas and flow rate: Nitrogen, 6.6 cm ³ / min Injection temperature: 220 ° C.
Split ratio: 0.006
Sample volume: 1 μL
Column and temperature conditions: TC-1, diameter 0.25 mm, 60 m, 40 ° C. → 200 ° C. (5 ° C./min)
Carrier gas and flow rate: Helium, 0.68 cm ³ / spinning speed: 16 cm / sec Internal standard: Toluene

(Example 2)
The reaction was conducted in the same manner as in Example 1 except that 0.6 mmol of triethylaluminum was used instead of triethylaluminum (0.1 mmol), diethylaluminum chloride (0.1 mmol) and ethylaluminum chloride (0.1 mmol). Went. Only C6 and C8 compounds were produced, and no change in weight of the heavy component, that is, the filter paper was observed. The C6 selectivity is 79 mol% (1-hexene selectivity 99%), the C8 selectivity is 21 mol% (1-octene selectivity 99%), and the catalyst efficiency of the C6 compound and the C8 compound is 300 C′2 mol / Cr mol h.

(Example 3)
Triethylaluminum (0.1 mmol), diethylaluminum chloride (0.1 mmol), and ethylaluminum chloride (0.1 mmol) were dissolved in toluene (30 ml) and introduced into a 100 ml autoclave. The autoclave was cooled with liquid nitrogen and ethylene was introduced. Chromium (III) chloride · 2-methoxyloyl (ditertiary butylphosphino) pyridine complex (10 μmol) was fed into the cooled autoclave enclosing ethylene in a nitrogen stream. After the temperature was raised to 100 ° C., the overall pressure was 6 MPa. After 20 minutes, the apparatus was cooled and the product was analyzed by gas chromatography. As a result, C4 selectivity was 4 mol% (1-butene selectivity 99%), C6 selectivity was 91 mol% (1-hexene selectivity 99%). ), The C8 selectivity was 5 mol% (1-octene selectivity 99%), and the catalyst efficiency of the C6 compound and the C8 compound was 850 C′2 mol / Cr mol h. When heavy substances were quantified in the same manner as in Example 1, no change was observed in the weight of the filter paper. “C4 selectivity” means the selectivity of all C4 compounds including 1-butene, and “1-butene selectivity” means the proportion of 1-butene in the C4 compounds.

Example 4
Triisobutylaluminum (110 μmol) was dissolved in toluene (30 ml) and introduced into a 100 ml autoclave. The autoclave was cooled with liquid nitrogen and ethylene was introduced. Chromium (III) chloride · 2-methoxyloyl (ditertiary butylphosphino) pyridine complex (10 μmol) was fed into the cooled autoclave enclosing ethylene in a nitrogen stream. After the temperature was raised to 100 ° C., the overall pressure was 6 MPa. After 20 minutes, the apparatus was cooled and the product was analyzed by gas chromatography. The C6 selectivity was 94 mol% (1-hexene selectivity 99%), and the C8 selectivity was 6 mol% (1-octene selectivity 99%). The catalytic efficiency of the C6 compound and the C8 compound was 460 C′2 mol / Cr mol h. When heavy substances were quantified in the same manner as in Example 1, no change was observed in the weight of the filter paper.

(Comparative Example 1)
The reaction was performed in the same manner as in Example 2 except that triethylaluminum was not used, but no product was observed.

(Comparative Example 2)
Triethylaluminum (110 μmol), diethylaluminum chloride (80 μmol) and 2,5-dimethylpyrrole (33 μmol) were dissolved in toluene (30 ml) and introduced into a 100 ml autoclave. The autoclave was cooled with liquid nitrogen and ethylene was introduced. Chromium (III) 2-ethylhexanoate (10 μmol) was fed into the cooled autoclave enclosing ethylene in a nitrogen stream. After the temperature was raised to 100 ° C., the overall pressure was 6 MPa. After 20 minutes, the apparatus was cooled and the product was analyzed by gas chromatography. The C6 selectivity was 93% (1-hexene selectivity 99%), the C8 selectivity was 7% (1-octene selectivity 99%). The catalytic efficiency of the C6 compound and the C8 compound was 280C′2 mol / Cr mol h. When the heavy material was quantified in the same manner as in Example 1, the weight of the filter paper slightly increased.

  In the production of 1-hexene and / or 1-octene by trimerization and / or tetramerization of ethylene, the present invention sufficiently suppresses the formation of polyethylene and wax, and reduces 1-hexene and / or 1-octene. It is possible to provide a method for efficiently synthesizing with high selectivity.

Claims (5)

In the presence of a compound represented by the following general formula (1), a chromium compound and an organoaluminum compound, ethylene is trimerized and / or tetramerized under the conditions of a temperature of 30 to 200 ° C. and a pressure of 100 kPa to 20 MPa. A process for producing 1-hexene and / or 1-octene, characterized in that hexene and / or 1-octene is obtained.

[Wherein, R ¹ , R ² , R ³ and R ⁴ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, R ¹ and R ² , R ² and R ³ , R ³ and R ⁴ may form a ring, R ⁵ and R ⁶ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and n represents an integer of 1 to 6. ]   2. The complex according to claim 1, wherein a complex of the compound represented by the general formula (1) and the chromium compound is used as the compound represented by the general formula (1) and the chromium compound. -A process for producing hexene and / or 1-octene. R ⁵ and R ⁶ in the general formula (1) are aromatic substituents,
A contact product between the compound represented by the general formula (1) and the chromium compound or a complex of the compound represented by the general formula (1) and the chromium compound is used as the organoaluminum compound and, if necessary. The method for producing 1-hexene and / or 1-octene according to claim 1 or 2, wherein the catalyst is prepared by contacting with a solvent to be contacted, and then the catalyst is contacted with the ethylene. R ⁵ and R ⁶ in the general formula (1) are alkyl groups,
A contact product between the compound represented by the general formula (1) and the chromium compound, a complex of the compound represented by the general formula (1) and the chromium compound, an organoaluminum compound, ethylene, and as necessary. The method for producing 1-hexene and / or 1-octene according to claim 1, wherein the mixture is mixed with a mixture of solvents used. The molar ratio between the organoaluminum compound and the chromium compound is 0.01 to 100,000 in terms of Al / Cr ratio, according to any one of claims 1 to 4. A method for producing hexene and / or 1-octene.