JPH10109946A - Production of alpha-olefin oligomer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for successively producing an α-olefin oligomer in a high catalyst efficiency, high yield and high selectivity by supplying a specific chromic catalyst so that the concentration of the chromium in a reaction zone may be within a specified range. SOLUTION: In this method for producing an α-olefin oligomer, (B) α-olefin in successively polymerized by successively charging (A) a chromic catalyst, which is a combination of a chromium compound (e.g. an alkoxy salt, a carboxyl salt, a halogenized material of chromium) (A1 ), a compound containing nitrogen such as an amine, an amide or an imide [e.g. a primary or a secondary amine, a compound of formula I (M<1> H, a metal of groups I, II, XI or XIII in the periodic table; R<1> is H, a 1-30C alkyl, etc.; R<2> is the R<1> , etc.)] (A2 ), an alkylaluminum compound (A3 ) and a compound containing a halogen e.g. a compound of formula II [X<1> to X<8> are each H or a halogen, with the proviso that three or more of X<1> to X<5> are the halogen; (r) is 0-8]} (A4 ), so that the chromium concentration in the reaction zone may be maintained to <=1ppm.

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 low polymer, and more particularly to a method for producing an α-olefin low polymer mainly composed of 1-hexene from ethylene with high yield and high selectivity. The present invention relates to an industrially advantageous method for producing an α-olefin low polymer which can be produced.

[0002]

2. Description of the Related Art Heretofore, as a method for low polymerization of an α-olefin such as ethylene, a method using a chromium catalyst comprising a chromium compound and an organoaluminum compound has been known. For example, Japanese Patent Publication No. 43-18707 discloses a chromium-based catalyst comprising a transition metal compound of Group 6 containing chromium and polyhydrocarbyl aluminum oxide.
A method for obtaining 1-hexene and polyethylene from ethylene is described.

JP-A-3-128904 discloses that an α-olefin is trimerized using a chromium-based catalyst obtained by previously reacting a compound having a chromium-pyrrolyl bond with a metal alkyl or Lewis acid. A method is described. Further, South African Patent ZA93 / 0350 discloses that ethylene is purified by using a chromium-based catalyst obtained by mixing a chromium salt, a pyrrole ring-containing compound, a metal alkyl and a halide source in a common solvent. Methods for quantification are described.

On the other hand, the present inventors have disclosed Japanese Patent Laid-Open No. 6-1452.
No. 41 employs a mode in which a chromium-based catalyst comprising a combination of a compound having a chromium-pyrrolyl bond and alkylaluminum is used, and a compound containing chromium does not come into contact with a metal alkyl compound before contacting with an α-olefin. The proposed low polymerization reaction of α-olefin was proposed. According to this method, in particular, by a low polymerization reaction of ethylene,
1-hexene can be obtained with high activity.

Further, the present inventors have disclosed a technique disclosed in Japanese Patent Application Laid-Open No. H6-1576.
No. 55 proposes a low-polymerization reaction of an α-olefin in which a compound obtained by reacting a chromium salt with a pyrrole ring-containing compound in a hydrocarbon solvent is brought into contact with an alkylaluminum compound in the same manner as described above. According to this method, the ethylene trimerization reaction can be performed with high activity, and 1-hexene having high purity can be produced.

Recently, the present inventors have disclosed in Japanese Patent Laid-Open No. 8-3
No. 216, a chromium catalyst comprising a combination of a chromium-containing compound, a pyrrole ring-containing compound, a metal alkyl compound and a halide source is used, and the chromium-containing compound does not come into contact with the metal alkyl compound before coming into contact with the α-olefin. A low polymerization reaction of an α-olefin employing the embodiment was proposed. According to this method, in particular, 1-hexene can be obtained with higher activity by a low polymerization reaction of ethylene.

[0007]

However, in the method described in JP-B-43-18707, under the condition that the amount of polyethylene produced simultaneously with 1-hexene is large and the amount of by-produced polyethylene is reduced, the catalyst is not used. There is a problem that activity is reduced. Also, JP-A-3-12890
In the method described in Japanese Patent Publication No. 4 (1994), the production amount of a high molecular weight polymer is small, but there is a problem that the catalytic activity is not sufficient.

[0008] South African patent ZA93 / 0350
Although the selectivity of 1-hexene is high in the method described in the specification, the catalytic activity is still insufficient from the viewpoint of an industrial method for producing an α-olefin low polymer. Further, JP-A-6-145241 and JP-A-6-15
Even in the method described in JP-A-7655, the catalytic performance is still insufficient from the viewpoint of an industrial method for producing an α-olefin low polymer. On the other hand, in the method described in JP-A-8-3216, a sufficiently high activity is achieved from the viewpoint of an industrial production method of an α-olefin low polymer, but the selectivity of 1-hexene is increased. Have the disadvantage of being inadequate.

The present invention has been made in view of the above-mentioned circumstances, and has as its object the industrial advantage that an α-olefin low polymer such as 1-hexene can be produced at an extremely high yield and a high selectivity. An object of the present invention is to provide a method for producing an α-olefin low polymer.

[0010]

According to the present invention, in producing an α-olefin low polymer by a continuous reaction method using a chromium-based catalyst, at least a chromium compound (a), an amine And a combination of a nitrogen-containing compound (b), an alkylaluminum compound (c) and a halogen-containing compound (d) selected from the group consisting of amides and amides, and maintaining the chromium concentration in the reaction zone at 1 ppm or less. By continuously feeding the catalyst to the reaction zone as described above, α-olefin low polymers can be produced with extremely high catalyst efficiency and selectivity.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, at least one chromium compound (a), at least one nitrogen-containing compound (b) selected from the group consisting of amines, amides and imides; (C)
And a catalyst prepared from the halogen-containing compound (d). The chromium-based catalyst used in the present invention can be prepared by a known method. As the chromium compound, a compound represented by the general formula CrXn is used. However, in the general formula, X is an arbitrary organic or inorganic group or a negative atom, n represents an integer of 1 to 6, and when n is 2 or more, Xs may be the same or different from each other . The valence of chromium is 0 to 6, and n in the above formula is preferably 2 or more.

Examples of the organic group include various groups having usually 1 to 30 carbon atoms. Specific examples include a hydrocarbon group, a carbonyl group, an alkoxy group, a carboxyl group, a β-diketonate group, a β-ketocarboxyl group, a β-ketoester group, and an amide group. Examples of the hydrocarbon group include an alkyl group, a cycloalkyl group, an aryl group, an alkylaryl group, an aralkyl group, and a cyclopentadienyl group. Examples of the inorganic group include a chromium salt-forming group such as a nitrate group and a sulfate group, and examples of the negative atom include oxygen and halogen.

Preferred chromium compounds belonging to this category are alkoxy salts of chromium, carboxyl salts, β-diketonate salts, salts with β-ketoester anions, or chromium halides. ) Tert-butoxide, chromium (III) acetylacetonate, chromium (III) trifluoroacetylacetonate, chromium (III) hexafluoroacetylacetonate, chromium (III) (2,2,6,6-tetramethyl-
3,5-heptane dionate), Cr (PhCOCHC)
OPh) ₃ (where Ph represents a phenyl group), chromium (II) acetate, chromium (III) acetate, chromium (III) 2-ethylhexanoate, chromium
(III) benzoate, chromium (III) naphthenate, Cr
(CH ₃ COCHCOOCH ₃ ) ₃ , chromium chloride, chromium chloride, chromium bromide, chromium bromide, chromium iodide, chromium iodide, chromium fluoride,
Chromic fluoride and the like can be mentioned. Further, a complex composed of the above chromium compound and an electron donor can also be suitably used. The electron donor is selected from compounds containing nitrogen, oxygen, phosphorus or sulfur.

Examples of the nitrogen-containing electron donor include nitriles, amines, amides, nitro compounds and the like. Specifically, acetonitrile, pyridine, dimethylpyridine, dimethylformamide, N-methylformamide,
Examples include aniline, nitrobenzene, tetramethylethylenediamine, diethylamine, isopropylamine, hexamethyldisilazane, and pyrrolidone.

Examples of the oxygen-containing electron donor include esters, ethers, ketones, alcohols, aldehydes, and the like. Specific examples include ethyl acetate, methyl acetate, tetrahydrofuran, dioxane, diethyl ether, dimethoxyethane, diglyme, and the like. Triglyme, acetone, methyl ethyl ketone, methanol, ethanol, acetaldehyde and the like.

Examples of the phosphorus-containing electron donor include hexamethylphosphoramide, hexamethylphosphorustriamide, triethylphosphite, tributylphosphine oxide, and triethylphosphine. Examples of the sulfur-containing electron donor include carbon disulfide, dimethyl sulfoxide, tetramethylene sulfone, thiophene, and dimethyl sulfide.

Of a complex comprising a chromium compound and an electron donor
Examples are, for example, chromium halide ether complexes,
Ester complex, ketone complex, aldehyde complex, alcohol
Complexes, amine complexes, nitrile complexes, phosphine complexes,
Thioether complexes and the like. Specifically, Cr
Cl_Three・ 3THF, CrCl_Three・ 3dioxane, Cr
Cl_Three・ (CH_ThreeCO_Twon-C_FourH₉), CrCl_Three・ (CH
_ThreeCO_TwoC_TwoH_Five), CrCl_Three・ 3 (i-C_ThreeH₇OH),
CrCl_Three.3 [CH_Three(CH_Two)_ThreeCH (C_TwoH_Five) CH_Two
OH], CrCl_Three・ 3pyridine, CrCl_Three・
2 (i-C_ThreeH₇NH_Two), [CrCl_Three・ 3CH_ThreeCN]
・ CH_ThreeCN, CrCl_Three・ 3PPh_Three, CrCl_Two・ 2T
HF, CrCl_Two・ 2pyridine, CrCl_Two・ 2
[(C_TwoH _Five)_Two NH], CrCl_Two・ 2CH_ThreeCN, Cr
Cl_Two.2 [P (CH_Three)_TwoPh] and the like. What
In the above, THF represents tetrahydrofuran.
You.

The chromium compound is preferably a compound soluble in a solvent used for preparing the catalyst, usually a hydrocarbon solvent.
Examples of such chromium compounds include chromium β-diketonate salts, carboxylate salts, salts with β-ketoester anions, β-ketocarboxylate salts, amide complexes, carbonyl complexes, carbene complexes, cyclopentadienyl complexes, alkyl Complexes, phenyl complexes and the like. Specific examples of chromium carbonyl complex, carbene complex, cyclopentadienyl complex, alkyl complex, and phenyl complex include:
Cr (CO) ₆ , (C ₆ H ₆ ) Cr (CO) ₃ , (CO) ₅
Cr (= CCH ₃ (OCH ₃ )), (CO) ₅ Cr (= C
_{C 6 H 5 (OCH 3)} ), CpCrCl 2 ( where Cp is a cyclopentadienyl group.), (Cp * CrClC
H ₃ ) ₂ (where Cp * indicates a pentamethylcyclopentadienyl group), (CH ₃ ) ₂ CrCl and the like.

The chromium compound can be used by being supported on a carrier such as an inorganic oxide. However, it is preferable to use the chromium compound in combination with another catalyst component without supporting the carrier. That is, the chromium-based catalyst used in the present invention is:
By appropriately controlling the preparation conditions, a high catalytic activity can be obtained without carrying a chromium compound on a carrier. And when the chromium compound is used without being supported on the carrier, the support on the carrier involving complicated operations can be omitted,
In addition, the problem of an increase in the total amount of catalyst used (total amount of the carrier and the catalyst component) due to the use of the carrier can be avoided.

The nitrogen-containing compound (b) used for preparing the catalyst
Is one or more compounds selected from the group consisting of amines, amides and imides. As the amine, a primary or secondary amine, or a mixture thereof is used. 1
As the secondary amine, ammonia, ethylamine, isopropylamine, cyclohexylamine, benzylamine,
Examples include aniline and naphthylamine. Examples of the secondary amine include diethylamine, diisopropylamine, dicyclohexylamine, dibenzylamine, bis (trimethylsilyl) amine, morpholine, imidazole, indoline, indole, pyrrole, 2,5-dimethylpyrrole, and 2,4-dimethylpyrrole, 3,4-diethylpyrrole, 2,3,4-trimethylpyrrole, 3,4-dichloropyrrole, 2,3,4,5-tetrachloropyrrole, 2-acetylpyrrole, 3,3 ′ , 4,4'-Tetramethyldipyrromethane, pyrazole, pyrrolidine and the like.

As the amide, those obtained by reacting the above primary or secondary amine with a metal selected from the group consisting of Groups 1, 2, 4, and 13 of the periodic table are used. . Examples of such metal amides include lithium amide, sodium ethylamide, calcium diethylamide, lithium diisopropylamide, potassium benzylamide, sodium bis (trimethylsilyl) amide, lithium indolide, sodium pyrrolide, lithium pyrrolide, potassium pyrrolide, Examples include potassium pyrrolidide, aluminum diethylpyrrolide, ethylaluminum dipyrrolide, aluminum tripyrolide, and lithium (2,5-dimethylpyrrolide). Further, acid amides and imides represented by the following (1) to (3) are also used.

[0022]

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In these equations (1) to (3), M ¹
To M ⁴ are each independently a hydrogen atom or group 1;
A metal element selected from Group 11, Group 13 or Group 13. R ¹ represents a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, an alkenyl group, an aralkyl group, an optionally substituted aryl group, or, an aryl group which may contain a hetero element, R ² Is a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, an alkenyl group, an aralkyl group, an aryl group which may have a substituent, an aryl group which may contain a hetero element, or an acyl group C (= O) R ³ (R ³
Is the same as R ¹ , but may be different from R ¹ ), and R ¹ and R ² may form a ring.

R ⁴ and R ^{5 each} represent a hydrogen atom, having 1 to 30 carbon atoms.
Represents an alkyl group, an alkenyl group, an aralkyl group, an aryl group optionally having a substituent, or an aryl group optionally containing a hetero element, wherein R ⁴ and R ⁵ form a ring. A represents an alkylene group which may contain an unsaturated bond. R ⁶ is a hydrogen atom, having 1 to 3 carbon atoms.
0 represents an alkyl group, an alkenyl group, an aralkyl group, an aryl group which may have a substituent, or an aryl group which may contain a hetero element, and R ⁷ is a hydrogen atom, a carbon atom having 1 to 30 carbon atoms. An alkyl group, an alkenyl group, an aralkyl group, an aryl group optionally having a substituent, an aryl group optionally containing a hetero element, or SO ₂
(Although the definition of R ⁸ is the same as R ^6, may be different from R ⁶⁾ R ⁸ group represents, R ⁶ and R ⁷ may form a ring.

Examples of the acid amide represented by the formula (1) or (2) include, for example, acetamide, N-methylhexaneamide, succinamide, maleamide, N-methylbenzamide, imidazole-2-carboxamide and di-amide.
2-thenoylamine, β-lactam, δ-lactam, ε
Caprolactam, and these and family 1 of the periodic table, 2
And salts with metals of Group 11, Group 13 or Group 13.

The sulfonamides and sulfonimides represented by the formula (3) include, for example, benzenesulfonamide, N-methylmethanesulfonamide, N-methyltrifluoromethanesulfonamide, and And salts with metals of groups 2, 2, 11 or 13. Examples of the imides include 1,2-cyclohexanedicarboximide, succinimide, phthalimide, maleimide, 2,4,6-piperidinetrione, perhydroazecin-2,10-dione, and those of the periodic table. Salts with metals of Groups 1, 2, 11, or 13 are mentioned. Among the acid amide or imide compounds described above, a compound represented by the formula (1) is preferable, and particularly, R ² in the formula (1) represents an acyl group C (＝ O) R ³ ,
An imide compound in which R ¹ and R ³ form a ring is preferred.

As the nitrogen-containing compound used for preparing the catalyst,
Secondary amines or metal amides derived therefrom are preferred. Particularly preferred are compounds having a pyrrole ring, namely pyrrole, 2,5-dimethylpyrrole, 3,4-dimethylpyrrole, 2,3,4-trimethylpyrrole,
3,4-dichloropyrrole, 2,3,4,5-tetrachloropyrrole, 2-acetylpyrrole, 3,3'-4,
4'-tetramethyldipyrrolomethane, aluminum pyrrolide, ethylaluminum dipyrrolide, aluminum tripyrolide, sodium pyrrolide, lithium pyrrolide,
Potassium pyrrolide, aluminum (2,5-dimethylpyrrolide), ethylaluminum bis (2,5-dimethylpyrrolide), aluminum tris (2,5-dimethylpyrrolide), sodium (2,5-dimethylpyrrolide) ,
Pyrrole, pyrrole derivatives such as lithium (2,5-dimethylpyrrolide) and potassium (2,5-dimethylpyrrolide), or metal pyrrolides thereof. Of these, those having a hydrocarbon group on the pyrrole ring, such as 2,5-dimethylpyrrole, are preferred.

As the alkylaluminum compound (c), a compound represented by the following formula (4) is preferably used. R ⁹ mAl (OR ¹⁰ ) n Hp Xq (4) In the formula (4), R ⁹ and R ^{10 each} usually have 1 to 15 carbon atoms.
It is preferably 1 to 8 hydrocarbon groups, which may be the same or different, and X represents a halogen atom. m,
n, p and q each represent a number, and m is 0 <m ≦ 3, n
Is 0 ≦ n <3, p is 0 ≦ p <3, q is 0 ≦ q <3, and m + n + p + q = 3. Examples of the alkylaluminum compound include a trialkylaluminum compound represented by the following formula (5), an alkylaluminum halide compound represented by the formula (6), an alkoxyalkylaluminum compound represented by the formula (7), And alkyl aluminum hydride compounds represented by 8).

R ⁹ ₃ Al (5) R ⁹ m AlX3-m (1.5 ≦ m <3) (6) R ⁹ m Al (OR ¹⁰ ) 3-m (0 <m <3, preferably 1.5 ≦ m <3) (7) R ⁹ m AlH3-m (0 <m <3, preferably 1.5 ≦ m <3) (8) Note that R ⁹ , X and The definition of R ¹⁰ is the same as in formula (4).

Specific examples of the above-mentioned alkylaluminum compound include trimethylaluminum, triethylaluminum, triisobutylaluminum, diethylaluminum monochloride, diethylaluminum ethoxide, diethylaluminum hydride and the like. These alkylaluminum compounds may be a mixture of two or more kinds, for example, a mixture of a trialkylaluminum compound and an alkylaluminum halide compound may be used. Among these, trialkylaluminum is particularly preferred in that the amount of by-products of the polymer is small.

As the halogen-containing compound (d), any compounds containing a halogen atom can be used, and usually, the following halogen-containing compounds (1) to (1) are used.
The halogen-containing compound (1) using any of (4) is selected from the group 3 and 4 of the periodic table,
It is a halogen-containing compound containing an element selected from Group 5, Group 6, Group 13, Group 14, and Group 15. For example, scandium chloride, yttrium chloride, lanthanum chloride, titanium tetrachloride, zirconium tetrachloride, hafnium tetrachloride, boron trichloride, aluminum chloride, diethyl aluminum chloride, ethyl aluminum sesquichloride, gallium chloride, carbon tetrachloride, chloroform, methylene chloride, Dichloroethane, hexachlorobenzene, 1,3,5-trichlorobenzene, trityl chloride, silane tetrachloride, trimethylchlorosilane, germanium tetrachloride, tin tetrachloride, tributyltin chloride, phosphorus trichloride, antimony trichloride, trityl hexachloroantimonate, pentachloride Antimony, bismuth trichloride, boron tribromide, aluminum tribromide, carbon tetrabromide, bromoform, bromobenzene, iodomethane, silicon tetrabromide, hexafluorobenzene Include aluminum fluoride and the like. Among these, a compound having a large number of halogen atoms is preferable, and a compound soluble in a solvent for performing a low polymerization reaction is preferable.
Halogen is preferably bromine or chlorine, and above all chlorine is preferred in terms of activity, selectivity of the target product, and the like. Particularly preferred halogen-containing compounds (1) are carbon tetrachloride, chloroform, dichloroethane, titanium tetrachloride, and tetrachloride. Germanium and tin tetrachloride. A mixture of two or more of these can also be used.

The halogen-containing compound (2) is a straight-chain hydrocarbon having 2 or more carbon atoms substituted with 3 or more halogen atoms. The straight-chain hydrocarbons in the halogen-containing compound (2) are preferably straight-chain saturated hydrocarbons. Linear hydrocarbons in which two or more adjacent carbons are substituted with three or more halogen atoms are preferable, and are represented by the formulas (9) and (1).
Linear halogenated hydrocarbons represented by (0) and (11) are particularly preferred.

[0033]

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In the formula (9), X ^{1 to} X ⁸ represent a hydrogen atom or a halogen atom, and at least three of X ^{1 to} X ⁵ are halogen atoms, and r is 0 to 8.

[0035]

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In the formula (10), X ^{9 to} X ¹¹ represent a halogen atom, X ^{12 to} X ¹⁶ are a halogen atom or a hydrogen atom, and s is 0 to 8.

[0037]

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In the formula (11), X ^{17 to} X ²⁰ represent a halogen atom, X ^{21 to} X ²⁴ are a halogen atom or a hydrogen atom, and w is 0 to 8. The halogen in the halogen-containing compound (2) is preferably chlorine or bromine, especially chlorine in view of the activity, selectivity of the target product and the like, and r, s and w in the formulas (9) to (11) are preferable. Is preferably 0 to 3, respectively. As the linear halogenated hydrocarbons represented by the formulas (9) to (11), specifically, 1,1,1-trichloroethane, 1,1,2-
Trichloroethane, 1,1,2,2-tetrachloroethane, pentachloroethane, hexachloroethane, 1,
1,1-trichloropropane, 1,1,2,2-tetrachloropropane, 1,1,1-trichlorobutane, 1,
1,2,2-tetrachlorobutane, 1,1,1-trichloropentane, 1,1,2,2-tetrachloropentane, 1,1,1-tribromoethane, 1,1,2,2-
Tetrabromoethane and the like. Among these,
In particular, 1,1,1-trichloroethane, pentachloroethane, hexachloroethane, and 1,1,2,2-tetrachloroethane are preferred.

The use of the halogen-containing compound (2) has an advantage that not only the catalytic activity and the selectivity of the trimer can be remarkably improved, but also the deterioration with time of the catalyst can be improved. The halogen-containing compound (3) is a halogenated cyclic hydrocarbon. As the cyclic hydrocarbon, a cyclic saturated hydrocarbon is preferable, and as the halogen-containing compound (3), a cyclic saturated hydrocarbon substituted with three halogen atoms is particularly preferable. As the halogen atom, chlorine or bromine, among them, chlorine is preferable in view of activity, selectivity of the target product and the like.

Specific examples of the halogen-containing compound (3) include 1,2,3-trichlorocyclopropane, 1,1,1
Trihalogenated cyclopropanes such as 2-trichlorocyclopropane, 1,2,3-tribromocyclopropane and 1,1,2-tribromocyclopropane;
Tetrahalogenation such as 3-tetrachlorocyclopropane, 1,1,2,2-tetrachlorocyclopropane, 1,1,2,3-tetrabromocyclopropane, 1,1,2,2-tetrabromocyclopropane Pentahalogenated cyclopropanes such as cyclopropane, pentachlorocyclopropane and pentabromocyclopropane; hexahalogenated cyclopropanes such as hexachlorocyclopropane and hexabromocyclopropane; 1,2,3-trichlorocyclobutane; -Trichlorocyclobutane,
Trihalogenated cyclobutane such as 1,2,3-tribromocyclobutane, 1,1,2-tribromocyclobutane, 1,2,3,4-tetrachlorocyclobutane, 1,
1,2,3-tetrachlorocyclobutane, 1,2,3
Tetrahalogenated cyclobutane such as 4-tetrabromocyclobutane, 1,1,2,3-tetrabromocyclobutane, 1,1,2,3,4-pentachlorocyclobutane,
1,1,2,2,3-pentachlorocyclobutane, 1,
1,2,3,4-pentabromocyclobutane, 1,1,
Pentahalogenated cyclobutane such as 2,2,3-pentabromocyclobutane, 1,1,2,2,3,4-hexachlorocyclobutane, 1,1,2,2,3,3-hexachlorocyclobutane, 1,1,1 Hexahalogenated cyclobutane such as 2,2,3,4-hexabromocyclobutane, 1,1,2,2,3,3-hexabromocyclobutane, heptahalogenated cyclobutane such as heptachlorocyclobutane, heptabromocyclobutane, octachloro Octahalogenated cyclobutanes such as cyclobutane and otakubromocyclobutane are exemplified.

Also, 1,2,3-trichlorocyclopentane, 1,1,2-trichlorocyclopentane, 1,1,2
Trihalogenated cyclopentane such as 2,3-tribromocyclopentane, 1,1,2-tribromocyclopentane, 1,2,3,4-tetrachlorocyclopentane,
1,1,2,3-tetrachlorocyclopentane, 1,
2,3,4-tetrabromocyclopentane, 1,1,
Tetrahalogenated cyclopentane such as 2,3-tetrabromocyclopentane, 1,2,3,4,5-pentachlorocyclopentane, 1,1,2,3,4-pentachlorocyclopentane, 1,1,1 2,2,3-pentachlorocyclopentane, 1,2,3,4,5-pentabromocyclopentane, 1,1,2,3,4-pentabromocyclopentane, 1,1,2,2,3 Pentahalogenated cyclopentanes such as -pentabromocyclopentane, 1,1,
2,3,4,5-hexachlorocyclopentane, 1,
Hexahalogenated cyclopentanes such as 1,2,3,4,5-hexabromocyclopentane, 1,1,2,2
3,4,5-heptachlorocyclopentane, 1,1,
Heptahalogenated cyclopentane such as 2,2,3,4,5-heptabromocyclopentane, 1,1,2,2
3,3,4,5-octachlorocyclopentane, 1,
Octahalogenated cyclopentanes such as 1,2,2,3,3,4,5-octabromocyclopentane; nonahalogenated cyclopentanes such as nonachlorocyclopentane; decahalogenated cyclopentanes such as decachlorocyclopentane; No.

Further, 1,2,3-trichlorocyclohexane, 1,1,2-trichlorocyclohexane, 1,1,
Trihalogenated cyclohexane such as 2,3-tribromocyclohexane and 1,1,2-tribromocyclohexane, 1,2,3,4-tetrachlorocyclohexane,
1,1,2,3-tetrachlorocyclohexane, 1,
2,3,4-tetrabromocyclohexane, 1,1,
Tetrahalogenated cyclohexane such as 2,3-tetrabromocyclohexane, 1,2,3,4,5-pentachlorocyclohexane, 1,1,2,3,4-pentachlorocyclohexane, 1,1,2,2 Penta such as 3-pentachlorocyclohexane, 1,2,3,4,5-pentabromocyclohexane, 1,1,2,3,4-pentabromocyclohexane, 1,1,2,2,3-pentabromocyclohexane Halogenated cyclohexane, 1,2,2
3,4,5,6-hexachlorocyclohexane, 1,
Hexahalogenated cyclohexane such as 2,3,4,5,6-hexabromocyclohexane, 1,1,2,3
4,5,6-heptachlorocyclohexane, 1,1,
Heptahalogenated cyclohexane such as 2,3,4,5,6-heptabromocyclohexane, 1,1,2,2
3,4,5,6-octachlorocyclohexane, 1,
Octahalogenated cyclohexane such as 1,2,2,3,4,5,6-octabromocyclohexane,
Nona halogenated cyclohexane such as 2,2,3,3,4,5,6-nonachlorocyclohexane, 1,1,2,2
Examples include decahalogenated cyclohexane such as 2,3,3,4,4,5,6-decachlorocyclohexane, undecahalogenated cyclohexane such as undecachlorocyclohexane, and dodecahalogenated cyclohexane such as dodecachlorocyclohexane.

Among the above, especially 1,2,3-trichlorocyclopropane, pentachlorocyclopropane,
2,3,4-tetrachlorocyclobutane, 1,2,3
4,5-pentachlorocyclopentane, 1,2,3
4,5,6-Hexachlorocyclohexane is preferred. The use of the halogen-containing compound (3) has an advantage that not only the catalytic activity and the selectivity of the trimerized product are remarkably improved, but also the deterioration with time of the catalyst can be improved. The halogen-containing compound (4) is represented by the following formula (12).

[0044]

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In the formula (12), R ^{11 to} R ¹⁴ represent hydrogen or an alkyl group, X ²⁵ represents a hydrogen atom, an alkyl group or a halogen atom, and X ²⁶ represents a halogen atom. Further, as the halogen, chlorine or bromine, particularly, chlorine is preferable in view of activity, selectivity of a target product and the like. As the halogen-containing compound (4), specifically, allyl chloride,
3,3-dichloro-1-propene, 3-chloro-1-butene, 3,3-dichloro-1-butene, 1-chloro-2
-Butene, 1,1-dichloro-2-butene, 3-chloro-3-methyl-1-butene, 3-chloro-1-pentene, 3,3-dichloro-1-pentene, 4-chloro-2
-Pentene, 4,4-dichloro-2-pentene, 1-chloro-2-pentene, 1,1-dichloro-2-pentene and the like, with allyl chloride being most preferred.

The use of the halogen-containing compound (4) not only significantly improves the catalytic activity and the selectivity of the trimer, but also uses a small amount of the halogen-containing compound because of the high activity per halogen atom. In addition, since the amount of halogen-containing decomposition products generated during the reaction step or distillation purification is small, it is possible to easily separate the halogen-containing impurities when purifying the obtained trimerized product, and to recover the target product with high purity. There is an advantage that can be.

In the present invention, the halogen-containing compound
As a compound, t-butyldimethylsilyl triflate
(T-BuMe_TwoSiOSO_TwoCF_Three), Trispentaf
Fluorophenylboron (B (C₆F_Five)_Three), Trifluo
Methanesulfonic acid (CF_ThreeSO _ThreeH),), Hexaflu
Oroisopropanol ((CF_Three)_TwoCHOH) is also suitable
Can be used for

In the case where chromic chloride is used as the chromium compound used for preparing the catalyst or diethylaluminum chloride is used as the alkylaluminum compound, either the chromium compound or the alkylaluminum compound contains a halogen. When these are used, they also function as halogen-containing compounds, so that the use of a separate halogen-containing compound (d) can be omitted if desired.

Chromium compound (a) for preparing the catalyst,
The ratio of the nitrogen-containing compound (b), the alkylaluminum compound (c) and the halogen-containing compound (d) is 0.1 to 1 mol of the chromium compound.
100 mol, preferably 0.1 to 10 mol, and the alkylaluminum compound is 0.1 to 500 mol, preferably 1 to 100 mol.
To 100 mol, and the halogen-containing compound is 0.1 to 100 mol, preferably 0.1 to 20 mol. Particularly preferred is a nitrogen-containing compound 1 to 1 mole of the chromium compound.
5 mol, 5 to 50 mol of alkylaluminum compound, and 1 to 10 mol of halogen-containing compound. Preparation of the catalyst is performed by mixing a chromium compound, a nitrogen-containing compound, an alkylaluminum compound and a halogen-containing compound in a solvent. Usually, a hydrocarbon solvent is used as the solvent. Further, a halogenated hydrocarbon can be used as a solvent.

In preparing the catalyst, the chromium compound (a) and the alkylaluminum compound (c) are preferably brought into contact in the presence of an olefin. As a result, a catalyst which is very excellent in both catalytic activity and trimer selectivity can be obtained. Although the details of the reason are unclear, it is considered that the unstable chromium complex generated by the reaction between the chromium compound and the alkylaluminum compound is stabilized by the coexisting olefin. The olefin is preferably present in a high concentration in the medium for preparing the catalyst, usually in an amount of 5 to 100 mol%. Preferably 10 to 100 mol%, especially 20 to 1
It is present so as to be 00 mol%. When the catalyst is prepared in an atmosphere in which a low-boiling α-olefin such as ethylene is present, the partial pressure is usually about 3 to 250 kg /
cm ² . The pressure of the low-boiling α-olefin is about 5 to 100 kg / cm ² , especially about 5 to 50 kg / c
It is preferable to prepare the catalyst in an atmosphere of m ² .

Examples of the mode of preparing the catalyst by bringing the chromium compound (a) and the alkylaluminum compound (c) into contact with each other in the presence of an olefin include (1) a nitrogen-containing compound (b) and an alkylaluminum compound (c). And a chromium compound (a) and an α-olefin are introduced into a solution containing the halogen-containing compound (d). (2) Chromium compound (a), halogen-containing compound (d)
And an alkylaluminum compound (c) and an α-olefin into a solution containing a nitrogen-containing compound (b). (3) A nitrogen-containing compound (b), an alkylaluminum compound (c) and an α-olefin are introduced into a solution containing a chromium compound (a) and a halogen-containing compound (d). (4) a chromium compound (a) in a solution containing an alkyl aluminum compound (c) and a halogen-containing compound (d);
A nitrogen-containing compound (b) and an α-olefin are introduced.

(5) An alkylaluminum compound (c), a halogen-containing compound (d) and an α-olefin are introduced into a solution containing a chromium compound (a) and a nitrogen-containing compound (b). (6) A chromium compound (a), a halogen-containing compound (d) and an α-olefin are introduced into a solution containing a nitrogen-containing compound (b) and an alkylaluminum compound (c). (7) A chromium compound (a), a nitrogen-containing compound (b), a halogen-containing compound (d) and an α-olefin are introduced into a solution containing an alkylaluminum compound (c).

(8) A halogen-containing compound (d), a nitrogen-containing compound (b), an alkylaluminum compound (c) and an α-olefin are introduced into a solution containing a chromium compound (a). And the like. The catalyst is prepared and used in advance, and a chromium compound (a), a nitrogen-containing compound (b), an alkylaluminum compound (c), and a halogen-containing compound (d) are added to the reaction zone of the α-olefin low polymerization reaction. Each can be fed to form a catalyst in the reaction zone. According to this embodiment in the low polymerization of ethylene,
As described above, the pressure of the α-olefin is about 3 to 250 kg.
It is preferable to supply each component forming the catalyst to the zone of / cm ² .

The α-olefin to be subjected to the low polymerization reaction includes a substituted or unsubstituted α-olefin having 2 to 30 carbon atoms. For example, ethylene, propylene, 1-
Butene, 1-hexene, 1-octene, 3-methyl-1
-Butene, 4-methyl-1-pentene and the like.
In particular, ethylene is preferred, and 1-hexene, a trimer thereof, can be obtained from ethylene with high yield and high selectivity.

As the reaction solvent for the low polymerization reaction, butane,
Pentane, 3-methylpentane, hexane, heptane,
A linear or alicyclic saturated hydrocarbon having 1 to 20 carbon atoms, such as 2-methylhexane, octane, cyclohexane, methylcyclohexane, and decalin, and an aromatic hydrocarbon such as benzene, toluene, xylene, ethylbenzene, mesitylene, and tetralin. Is used. These can be used alone or as a mixed solvent. The α-olefin itself as a reaction raw material or an α-olefin other than the main raw material can be used as a reaction solvent. For the reaction solvent, α-olefins having 4 to 30 carbon atoms are used, and α-olefins which are liquid at room temperature are particularly preferred.

Particularly preferred as the solvent is one having 4 carbon atoms.
To 7 chain saturated hydrocarbons or alicyclic saturated hydrocarbons. By using these solvents, by-products of the polymer can be suppressed, and when an alicyclic saturated hydrocarbon is used, there is an advantage that a high catalytic activity can be obtained. The reaction temperature is generally 0 to 250 ° C, preferably 10
To 150 ° C, more preferably 20 to 100 ° C. On the other hand, the reaction pressure can be usually selected from a range of 3 to 250 kg / cm ² , but preferably is about 5 to 100 kg / cm ^2.
m ² . The residence time is usually in the range of 1 minute to 20 hours, preferably 0.5 to 6 hours.

If hydrogen is allowed to coexist during the reaction,
It is preferable because improvement in the catalytic activity and the selectivity of the trimer can be recognized. The amount of coexisting hydrogen is usually 0.1 to 100 kg / cm ² , preferably 1 to 80 kg as hydrogen partial pressure.
/ Cm ² . The reaction is a continuous reaction system, that is, the raw material α-olefin is continuously supplied to the reaction zone,
The reaction is carried out in such a manner that the produced low polymer is continuously discharged from the reaction zone. As the reactor, any one commonly used for a continuous reaction, such as a stirring tank, a tubular reactor, a bubble column, etc., can be used.

In the present invention, the catalyst is continuously supplied to the reaction zone. The supply rate must be such that the chromium concentration in the liquid phase in the reaction zone is 1 ppm or less. If the chromium concentration in the reaction zone is too high, both the catalytic activity and the selectivity of the α-olefin low polymer decrease. However, if the chromium concentration in the reaction zone is too low, the reaction rate decreases and the reaction zone becomes impractical, so the chromium concentration in the reaction zone is 0.01 to 1 ppm, particularly 0.1 to 0.5 ppm.
It is preferable to control it in the range of ppm. In the present invention, the chromium concentration is the weight of chromium metal per unit weight of the solution. Separation of the product from the reaction solution flowing out of the reaction zone can be performed according to a conventional method. Usually, the by-product polymer in the reaction solution is first removed by using an appropriate solid-liquid separator, and then separated into components by distillation.

[0059]

EXAMPLES The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. Example 1 2 having two catalyst supply pipes and one reaction liquid discharge pipe
One liter of the autoclave was dried and assembled in a dryer at 150 ° C., and then purged with vacuum nitrogen. In this autoclave, 0.031 mmol / hr of 2,5-dimethylpyrrole, 0.16 mmol / hr of triethylaluminum and 0.06 mmol / hr of carbon tetrachloride were supplied from one catalyst supply tube.
Each was continuously supplied as an n-heptane solution at a supply rate of 21 mmol / hr. From the other catalyst supply tube, 0.010 mmol / hr (5.0 mg / hr) of chromium (III) 2-ethylhexanoate was added together with ethylene.
At a feed rate of n-heptane. The total supply of n-heptane to the autoclave is 1 liter / hr. Keep the autoclave at 80 ° C,
Ethylene was continuously supplied so that the total pressure became 35 kg / cm ² G to cause a low polymerization reaction of ethylene. From the autoclave, make the content liquid 1 liter,
The reaction solution was withdrawn through a reaction solution withdrawing tube. The extracted reaction solution was introduced into a degassing tank, degassed to normal pressure, and the liquid component and the gas component were analyzed by gas chromatography. Table 1 shows the results.

Example 2 The feed rate of the catalyst-forming component to the autoclave was changed to 2,62-dimethylpyrrole 0.062 mmol / hr triethylaluminum 0.31 mmol / hr carbon tetrachloride 0.042 mmol / hr chromium (III) 2-ethyl The reaction was carried out in the same manner as in Example 1 except that the hexanoate was changed to 0.021 mmol / hr. Table 1 shows the results.

Example 3 A reaction was carried out in the same manner as in Example 2 except that ethylene was supplied so that the pressure in the autoclave was 50 kg / cm ² G. Table 1 shows the results.

Comparative Example 1 The supply rate of the catalyst-forming component to the autoclave was as follows: 2,5-dimethylpyrrole 0.37 mmol / hr triethylaluminum 1.9 mmol / hr carbon tetrachloride 0.26 mmol / hr chromium (III) 2-ethyl The reaction was carried out in the same manner as in Example 1 except that hexanoate was changed to 0.13 mmol / hr. Table 1 shows the results.

Comparative Example 2 A reaction was carried out in the same manner as in Example 1 except that the supply rate of the catalyst-forming component to the autoclave was changed as shown in Table 1. Table 1 shows the results.

Example 4 A sample having two catalyst supply tubes and one reaction solution withdrawing tube
One liter of the autoclave was dried and assembled in a dryer at 150 ° C., and then purged with vacuum nitrogen. To this autoclave, n-heptane was supplied at a supply rate of 0.067 mmol / hr of 2,5-dimethylpyrrole, 0.448 mmol / hr of triethylaluminum, and 0.045 mmol / hr of hexachloroethane from one catalyst supply tube. It was fed continuously as a solution. From the other catalyst supply pipe, chromium (III) 2-ethylhexanoate was added together with ethylene at 0.011 mmol / hr (5.4
(mg / hr) as an n-heptane solution. The total supply of n-heptane to the autoclave is 1.8 l / hr. The autoclave was kept at 80 ° C., and ethylene was continuously supplied so that the total pressure became 35 kg / cm ² G, thereby causing a low polymerization reaction of ethylene. The reaction solution was withdrawn from the autoclave via a reaction solution withdrawal tube so that the content liquid was 1 liter. The extracted reaction solution was introduced into a degassing tank, degassed to normal pressure, and the liquid component and the gas component were analyzed by gas chromatography. Table 1 shows the results.

Examples 5 to 16 Example 4 was repeated except that the supply rate of the catalyst-forming component to the autoclave or the reaction conditions were changed as shown in Tables 1 and 2.
The reaction was carried out in the same manner as in. The results are shown in Tables 1 and 2.

[0066]

[Table 1]

[0067]

[Table 2]

[0068]

According to the production method of the present invention, an α-olefin low polymer such as 1-hexene can be produced with an extremely high yield and a high selectivity.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI // C07B 61/00 300 C07B 61/00 300 (72) Inventor Takeshi Okano 3-10 Utsudori, Kurashiki-shi, Okayama Prefecture Mitsubishi Chemical Corporation Mizushima Office

Claims (6)

[Claims] When producing an α-olefin low polymer by a continuous reaction method using a chromium catalyst, the chromium catalyst is selected from the group consisting of at least a chromium compound (a), an amine, an amide and an imide. A catalyst comprising a combination of a nitrogen-containing compound (b), an alkylaluminum compound (c) and a halogen-containing compound (d), and a catalyst continuously connected to the reaction zone such that the chromium concentration in the reaction zone is maintained at 1 ppm or less. A process for producing an α-olefin low polymer, characterized in that it is supplied in a continuous manner. 2. The method according to claim 1, wherein at least one of the chromium compound (a) and the alkylaluminum compound (c) is a compound containing a halogen, and this compound is also used as the halogen-containing compound (d). The method for producing an α-olefin low polymer according to claim 1. 3. A chromium compound (a) which is at least a compound soluble in a solvent used for preparing a catalyst, a nitrogen-containing compound (b) which is a compound having at least a pyrrole ring, and an alkylaluminum compound (c) which is at least a trialkyl The method for producing an α-olefin low polymer according to claim 1 or 2, wherein aluminum is used. 4. The chromium-based catalyst is prepared through a process of contacting a chromium compound (a) and an alkylaluminum compound (c) in the presence of an α-olefin. 4. The method for producing an α-olefin low polymer according to any one of 1 to 3. 5. The method for producing an α-olefin low polymer according to claim 1, wherein the chromium-based catalyst is prepared in a reaction zone. 6. The α-olefin low polymer according to claim 1, wherein the α-olefin to be subjected to the low polymerization reaction is ethylene and the main product is 1-hexene. Production method.