JP3505211B2 - Method for producing low α-olefin polymer - Google Patents

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

[0002]

2. Description of the Related Art Conventionally, as a method for low polymerization of α-olefin such as ethylene, there has been known a method of using a chromium-based catalyst comprising a combination of a specific chromium compound and a specific organoaluminum compound. For example, Japanese Patent Publication No.
8707 describes a method for obtaining 1-hexene from ethylene by a catalyst system composed of a transition metal compound (M) of Group VIA containing chromium and having a general formula MXn and polyhydrocarbyl aluminum oxide (X). ing.

Further, in JP-A-3-128904, α-olefin is trimerized by using a catalyst obtained by previously reacting a chromium-containing compound having a chromium-pyrrolyl bond with a metal alkyl or Lewis acid. How to do is described.

[0004]

However, in the method described in Japanese Patent Publication No. 43-18707, the amount of polyethylene by-produced at the same time as 1-hexene is large and the amount of polyethylene by-produced is small. There is a problem that the catalytic activity is lowered. In addition, JP-A-3-12890
The method described in Japanese Patent No. 4 has a problem that although the amount of by-produced polymers such as polyethylene is small, the catalytic activity is not sufficient.

Moreover, the method described in JP-A-3-128904 uses a chromium-containing compound having a chromium-pyrrolyl bond as a catalyst in addition to the low polymerization process of α-olefin, and therefore, a chromium salt and a metal pyrrolide are used. The reaction step and the step of isolating the obtained chromium-containing compound are required, and the operation is complicated, and the construction cost required for the entire manufacturing process is high. Further, since the chromium-containing compound having a chromium-pyrrolyl bond is a substance that is extremely unstable to air and humidity, it has a drawback that it is not easy to handle.

The present invention has been made in view of the above situation, and an object thereof is to industrially advantageously 1-without complicated operations.
It is an object of the present invention to provide a method for producing an α-olefin low polymer capable of producing an α-olefin low polymer such as hexene with high yield and high selectivity.

[0007]

The inventors of the present invention have conducted extensive studies to achieve the above object, and as a result, when a specific chromium-based catalyst is used in a specific contact mode, the amount of α-olefin is reduced. It was found that a polymerization reaction, particularly a low polymerization reaction mainly composed of trimerization of ethylene proceeds highly active to produce highly pure 1-hexene.

The present invention has been completed based on the above findings, and the gist thereof is, in a method for producing an α-olefin low polymer using a chromium-based catalyst, at least a chromium compound as a chromium-based catalyst. And an amine or a metal amide and an alkylaluminum compound are used as a catalyst system, and the α-olefin and the chromium-based catalyst are contacted in a solvent in such a manner that the chromium compound and the alkylaluminum compound do not come in contact with each other beforehand. The method for producing an α-olefin low polymer is characterized by using a reactor having a plurality of different reaction zones when performing the low polymerization of.

The present invention will be described in detail below. In the present invention, a catalyst system comprising at least a combination of a chromium compound and an amine or a metal amide and an alkylaluminum compound is used as the chromium-based catalyst.

The chromium compound used in the present invention is represented by the general formula CrXn. However, in the general formula, X represents an arbitrary organic group or inorganic group or a negative atom, n represents an integer of 1 to 6, and when n is 2 or more, X may be the same or different from each other. Good. 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 thereof 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 and an aralkyl 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.

The preferred chromium compound is an alkoxy salt of chromium, a carboxyl salt, a β-diketonate salt, a salt of β-ketoester with an anion, or a chromium halide, specifically, chromium (IV) tert-butoxide. , Chromium (III) acetylacetonate, chromium (III)
Trifluoroacetylacetonate, chromium (III) Hexafluoroacetylacetonate, chromium (III) (2
2,6,6-tetramethyl-3,5-heptanedionate), Cr (PhCOCHCOPh) ₃ (provided that P is
h 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 (III) chloride , Chromium chloride, chromium bromide, chromium bromide, chromium iodide, chromium iodide, chromium fluoride, chromium fluoride and the like.

Further, a complex composed of the above-mentioned chromium compound and an electron donor can also be preferably used. The electron donor is selected from compounds containing nitrogen, oxygen, phosphorus or sulfur.

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

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

Examples of phosphorus-containing compounds include hexamethylphosphamide, hexamethylphosphorus triamide, triethylphosphite, tributylphosphine oxide, triethylphosphine and the like. On the other hand, examples of the sulfur-containing compound include carbon disulfide, dimethyl sulfoxide, tetramethylene sulfone, thiophene and dimethyl sulfide.

Therefore, as an example of a complex composed of a chromium compound and an electron donor, a chromium halide ether complex,
Ester complex, ketone complex, aldehyde complex, alcohol complex, amine complex, nitrile complex, phosphine complex,
Examples thereof include thioether complexes. Specifically, Cr
Cl ₃ / 3THF, CrCl ₃ / 3dioxane, C
_{rCl 3 · (CH 3 CO 2} n-C 4 H 9), CrCl 3
_{· (CH 3 CO 2 C 2} H 5), CrCl 3 · 3 (i-C
₃ H ₇ OH), CrCl ₃ · 3 [CH ₃ (CH ₂ ) ₃ C
H (C ₂ H ₅ ) CH ₂ OH], CrCl ₃ / 3pyri
_{dine, CrCl 3 · 2 (i} -C 3 H 7 NH 2),
[CrCl ₃ · 3CH ₃ CN] · CH ₃ CN, CrCl
_{3 · 3PPh 3, CrCl 2 ·} 2THF, CrCl 2 ·
2pyridine, CrCl ₂ · 2 [(C ₂ H ₅ ) ₂ N
H], CrCl ₂ · 2CH ₃ CN, CrCl ₂ · 2 [P
(CH ₃ ) ₂ Ph] and the like.

The chromium compound can be used in a hydrocarbon solvent.
Soluble compounds are preferred, chromium β-diketonate salts,
Carboxylates, salts with anions of β-ketoesters, β
-Ketocarboxylates, amide complexes, carbonyl complexes,
Ruben complex, various cyclopentadienyl complexes, alkyl
Examples thereof include complexes and phenyl complexes. Various chrome power
Rubonyl complex, carbene complex, cyclopentadienyl complex
As the body, the alkyl complex, and the phenyl complex,
Is Cr (CO)₆, (C₆H₆) Cr (CO) ₃,
(CO)_FiveCr (= CCH₃(OCH₃)), (CO)
_FiveCr (= CC₆H_Five(OCH₃)), CpCrCl₂
(Where Cp represents a cyclopentadienyl group), (
Cp * CrClCH₃)₂(Where Cp * is pentamethyl
Indicates a cyclopentadienyl group. ), (CH₃)₂CrC
1 and the like are exemplified.

The chromium compound can be used by supporting it on a carrier such as an inorganic oxide, but it is preferable to use it in combination with other catalyst components without supporting it on the carrier. That is, in the present invention, the chromium-based catalyst is used in a specific contact mode described later, but according to such a mode, high catalytic activity can be obtained without supporting the chromium compound on the carrier. When the chromium compound is used without being loaded on the carrier, the loading on the carrier which involves complicated operations can be omitted, and the total amount of the catalyst used (the total amount of the carrier and the catalyst component) is increased by the use of the carrier. It is possible to avoid the problem.

The amine used in the present invention is a primary or secondary amine.
It is a class amine. As the primary amine, ammonia,
Ethylamine, isopropylamine, cyclohexylamine, benzylamine, aniline, naphthylamine, etc. are exemplified, and secondary amines include diethylamine, diisopropylamine, dicyclohexylamine, dibenzylamine, bis (trimethylsilyl) amine, morpholine, imidazole, indoline, indole. , Pyrrole, 2,5-dimethylpyrrole, 3,4-dimethylpyrrole, 3,4-dichloropyrrole, 2,3,4,5-tetrachloropyrrole, 2-acylpyrrole, pyrazole and pyrrolidine.

The metal amide used in the present invention is a metal amide derived from a primary or secondary amine, specifically, a primary or secondary amine and a group IA or IIA,
An amide obtained by reaction with a metal selected from Group IIIB and Group IVB. Specific 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 and potassium. Examples thereof include pyrrolide, potassium pyrrolidide, aluminum diethylpyrrolide, ethylaluminum dipyrrolide and aluminum tripyrolide.

In the present invention, a secondary amine, a metal amide derived from a secondary amine, or a mixture thereof is preferably used. Particularly, as the secondary amine, pyrrole, 2,5-dimethylpyrrole, 3,4-dimethylpyrrole, 3,4-dichloropyrrole, 2,3,4,5
-Tetrachloropyrrole, 2-acylpyrrole, and metal amides derived from secondary amines include aluminum pyrrolide, ethylaluminum dipyrrolide, aluminum tripyrolide, sodium pyrrolide, lithium pyrrolide and potassium pyrrolide. It is suitable. Among the pyrrole derivatives, those having a hydrocarbon group on the pyrrole ring are particularly preferable.

In the present invention, an alkylaluminum compound represented by the following general formula (1) is preferably used as the alkylaluminum compound.

Embedded image R ¹ _m Al (OR ² ) _n H _p X _q (1)

In the formula, R ¹ and R ² usually have 1 to 10 carbon atoms.
15, preferably 1 to 8 hydrocarbon groups, which may be the same or different from each other, X represents a halogen atom, m is 0 <m ≦ 3, n is 0 ≦ n <3, p Is 0 ≦ p <
3 and q are numbers of 0 ≦ q <3, and
It represents a number that is m + n + p + q = 3.

Examples of the alkylaluminum compound include trialkylaluminum compounds represented by the following general formula (2), halogenated alkylaluminum compounds represented by the general formula (3), and alkoxy groups represented by the general formula (4). Examples thereof include aluminum compounds and alkylaluminum hydride compounds represented by the general formula (5). The meanings of R ¹ , X and R ² in each formula are the same as above.

[0026]

Embedded image R ¹ ₃ Al (2) R ¹ _m AlX _3-m (m is 1.5 ≦ m <3) (3) R ¹ _m Al (OR ² ) _3-m ( m is 0 <m <3, preferably 1.5 ≦ m <3) (4) R ¹ _m AlH _3-m (5) (m is 0 <m <3, preferably 1. 5 ≦ m <3)

Specific examples of the above-mentioned alkylaluminum compound include trimethylaluminum, triethylaluminum, triisobutylaluminum, diethylaluminum monochloride, diethylaluminum ethoxide, diethylaluminum hydride and the like. Among these, trialkylaluminums are particularly preferable in that the amount of polymer by-products is small.

In the present invention, a low polymerization of α-olefin is carried out in a solvent using a catalyst system comprising the above catalyst components. Then, it is important to contact the α-olefin and the chromium-based catalyst in such a manner that the chromium compound and the alkylaluminum compound do not come into contact with each other in advance to carry out low polymerization of the α-olefin. According to such a specific contact mode, it is possible to selectively carry out the trimerization reaction and obtain 1-hexene from the raw material ethylene in a high yield.

The above-mentioned specific contact mode is specifically as follows.
When the amine is represented by “amine or metal amide”, (1) a method of introducing α-olefin and a chromium compound into a solution containing an amine and an alkylaluminum compound, and (2) α into a solution containing a chromium compound and an amine. A method of introducing an olefin and an alkylaluminum compound, (3) a method of introducing α-olefin, an amine and an alkylaluminum compound into a solution containing a chromium compound, (4) an α-olefin in a solution containing an alkylaluminum compound, It can be performed by a method of introducing a chromium compound and an amine. And
Each of the above solutions is usually prepared using a reaction solvent.

In the present invention, "a mode in which a chromium compound and an alkylaluminum compound do not come into contact in advance"
Means not only at the start of the reaction, but also after the additional α-
It means that such a mode is maintained in the supply of the olefin and the catalyst component to the reactor.

The reason why the activity of the low polymerization reaction of α-olefin becomes low when the chromium-based catalyst is used in such a manner that the chromium compound and the alkylaluminum compound are in contact with each other in advance is not clear, but it is presumed as follows. To be done.

That is, it is considered that when the chromium compound and the alkylaluminum are brought into contact with each other, the ligand exchange reaction proceeds between the ligand coordinated with the chromium compound and the alkyl group in the alkylaluminum compound. And, the alkyl-chromium compound produced by such a reaction is unstable in itself, unlike the alkyl-chromium compound obtained by a usual method. Therefore, alkyl-
The decomposition / reduction reaction of the chromium compound preferentially proceeds, and as a result, inappropriate demetallation is induced in the low polymerization reaction of α-olefin, and the activity of the low polymerization reaction of α-olefin decreases.

In the present invention, the above specific contact is performed in a plurality of different zones. Specifically, a pipe reactor or a multi-stage mixing tank is used as the reaction device. The pipe reactor is basically a reaction device of a type in which a reaction component is introduced from one end of a straight pipe or a coiled or U-shaped bent pipe and a reaction product is allowed to flow out from the other end. Basically, a multi-stage mixing tank is a type in which reaction components are introduced into the first tank of a plurality of mixing tanks arranged in series, sequentially moved to the subsequent tanks, and the reaction products flow out from the final tank. It is a reactor.

In the present invention, when a pipe reactor is used, some of the necessary reaction components are introduced from one end of a straight pipe or a curved pipe, and the remaining components are introduced in the middle thereof. For example, the amine or metal amide and the alkylaluminum compound are introduced from the tip of the pipe reactor, and the α-olefin and the chromium compound are introduced from the middle of the pipe reactor. Further, for example, the chromium compound and the amine or metal amide are introduced from the tip of the pipe reactor, and the α-olefin and the alkylaluminum compound are introduced from the middle of the pipe reactor. Further, in the use of the pipe reactor, the introduction positions of the reaction components are not limited to two as long as the α-olefin and the chromium-based catalyst can be brought into contact with each other in such a manner that the chromium compound and the alkylaluminum compound do not come into contact with each other in advance.

In the present invention, when a multi-stage mixing tank is used, for example, an amine or metal amide and an alkylaluminum compound are introduced into the first tank, and an α-olefin and a chromium compound are introduced into the second tank. Also, for example, the first
The amine or metal amide and the alkylaluminum compound are introduced into the tank, and the α-olefin and the chromium compound are introduced into the second tank. And even when using a multi-stage mixing tank,
The number of mixing tanks is not limited to two as long as the α-olefin and the chromium-based catalyst can be brought into contact with each other in such a manner that the chromium compound and the alkylaluminum compound do not come into contact with each other in advance.

In the present invention, as the starting α-olefin, a substituted or unsubstituted α-olefin having 2 to 30 carbon atoms is used. Specific examples include ethylene, propylene, 1-butene, 1-hexene, 1-octene, 3-methyl-1-butene, 4-methyl-1-pentene and the like. Particularly, ethylene is suitable as the raw material α-olefin, and 1-hexene, which is a trimer of ethylene, can be obtained from ethylene in high yield and high selectivity.

In the present invention, the solvent is butane,
Linear or alicyclic saturated hydrocarbons such as pentane, hexane, heptane, octane, cyclohexane, methylcyclohexane and decalin, aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, mesitylene and tetralin, chloroform and tetrachloride. Chain chlorinated hydrocarbons such as carbon, methylene chloride, dichloroethane, trichloroethane and tetrachloroethane, and chlorinated aromatic hydrocarbons such as chlorobenzene and dichlorobenzene are used. These may be used alone or as a mixed solvent.

Further, as the solvent, the α-olefin itself as the reaction raw material or the α-olefin other than the main raw material can be used. As a solvent, it has 4 to 30 carbon atoms.
Although the α-olefins are used, α-olefins which are liquid at room temperature are particularly preferable.

As the solvent, a linear saturated hydrocarbon having 4 to 7 carbon atoms or an alicyclic saturated hydrocarbon is particularly preferable. By using these solvents, it is possible to suppress the by-product of the polymer, and further, when the alicyclic hydrocarbon is used, there is an advantage that a high catalytic activity can be obtained.

In the present invention, the amount of chromium compound used is usually 0.1 × 10 ^{−3 to} 5 per liter of solvent.
g, preferably in the range of 1.0 × 10 ^{−3 to} 2 g.
On the other hand, the amount of the alkylaluminum compound used is usually 0.1 mmol or more per 1 g of the chromium compound,
5 mmol from the viewpoint of catalytic activity and selectivity of trimer
The above is preferable. And the upper limit is usually 50 mol
Is. The amount of the amine or metal amide used is usually 0.001 equivalent or more per 1 g of the chromium compound,
The range is preferably 0.005 to 1000 equivalents, and more preferably 0.01 to 100 equivalents.

In the present invention, the chromium compound (a),
The molar ratio (a) :( b) :( c) of amine or metal amide (b) and alkylaluminum compound (c) is 1: 2.
It is preferred that the low polymerization of the α-olefin is carried out under the condition that the reaction temperature is 70 ° C. or lower. Due to the combination of such specific conditions, as an α-olefin low polymer,
For example, hexene can be produced in a yield of 90% or more (ratio to the total amount produced), and the purity of 1-hexene in hexene can be increased to 99% or more.

A preferable molar ratio of each of the above catalyst components,
(A) :( b) :( c) is 1: 2.5 to 3.5: 4.
The reaction temperature is 5 to 5.5, and the preferable reaction temperature is 0 to 60 ° C. On the other hand, the reaction pressure is from normal pressure to 250 kg / cm.
Can be selected from the range of ² , but usually 100 kg / cm
A pressure of ² is sufficient. The residence time is usually in the range of 1 minute to 20 hours, preferably 0.5 to 6 hours. Further, if hydrogen is allowed to coexist during the reaction, the catalytic activity and the selectivity of the trimer are improved, which is preferable.

Separation and removal of the by-product polymer in the reaction solution is carried out by appropriately using a known solid-liquid separation device, and the recovered α
-Olefin low polymer is purified if necessary. Distillation purification is usually employed for purification, and the target component can be recovered in high purity. In the present invention, in particular, highly pure 1-hexene can be industrially advantageously produced from ethylene.

[0044]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples as long as the gist thereof is not exceeded.

Example 1 As a reactor, a pressure resistant flexible tube having an inner diameter of 6 mm and a length of 10.5 m was placed inside a jacket, and a catalyst foot tube was provided in the middle of the flexible tube (position 0.5 m from the tip). A reactor was used. After replacing the pipe reactor with vacuum nitrogen, the internal temperature of the jacket was maintained at 100 ° C.

From the tip of the pipe reactor, 253 ml / Hr of n-heptane, 10 ml / Hr of n-heptane solution of pyrrole (0.017 mmol / ml), and n-heptane solution of triethylaluminum (0.453 m
(mol / ml) was continuously introduced at a rate of 10 ml / Hr, while chromium (III) -acetylacetonate (5. 5) slurried with n-heptane from the catalyst feed tube.
6 mg, 0.0164 mmol / ml) to 10 ml / H
It was introduced continuously with ethylene at 100 ° C. at a rate of r. The reaction pressure was set to 35 Kg / cm ² by ethylene pressure. The introduction speed of each component was adjusted so that the residence time was 1 hour. The reaction liquid flowing out from the pipe reactor is
It was connected to a pipe reactor and introduced into a pressure vessel separately arranged. Then, ethanol was pressed into the reaction liquid in the pressure vessel to stop the reaction.

After depressurizing the pressure of the pressure vessel and degassing, the by-produced polymer (mainly polyethylene) in the reaction solution was separated and removed by a filter to recover the α-olefin low polymer. Table 1 shows the results of the composition analysis of the α-olefin low polymer by gas chromatography.

Examples 2 to 12 The reaction was carried out in the same manner as in Example 1 except that the conditions shown in Tables 1 to 3 were adopted. However, in Example 12, 2,5-dimethylpyrrole was used instead of pyrrole. The results are shown in Tables 1 to 3.

Example 13 In Example 1, in order to change the contact method between ethylene and a chromium-based catalyst, n-
253 ml / h of heptane, chromium (III) (2-
Ethyl hexanoate) in n-heptane (107.
6 mg, 0.226 mmol / ml) to 10 ml / H
An n-heptane solution of r, 2,5-dimethylpyrrole (0.012 mmol / ml) was continuously introduced at a rate of 10 ml / Hr, and a heptane solution of triethylaluminum (0.037 mmol / m) was introduced from a catalyst feed tube.
The reaction was performed in the same manner as in Example 1 except that l) was continuously introduced at a rate of 10 ml / Hr together with ethylene at 100 ° C. The results are shown in Table 4.

Examples 14 to 17 As a reactor, a multi-stage mixing tank was used in which two 2.4 liter (1 liter of liquid) autoclaves were arranged in series, and the autoclaves were connected by overflow pipes. Each autoclave was heated and dried in a dryer at 150 ° C. to assemble it while hot, and then vacuum nitrogen substitution was performed. In the first autoclave, n-heptane 970 ml / Hr, pyrrole n-heptane solution (0.124 mmol / ml)
10 ml / Hr, triethylaluminum n-heptane solution (0.200 mmol / ml) 10 ml / H
It was continuously introduced at a rate of r, and the resulting mixed solution was overflowed into the second autoclave. At the same time, the second
(3) Chromium (III) -acetylacetonate slurried in n-heptane (14 mg, 0.
042 mmol / ml) was introduced continuously with ethylene at a rate of 10 ml / Hr. As the reaction conditions, the conditions shown in Tables 4 to 5 were adopted. The reaction pressure was adjusted by ethylene pressure, and the residence time was adjusted by the introduction rate of each component. Second
The reaction liquid flowing out from the overflow pipe of the autoclave was introduced into a pressure vessel separately connected to the overflow pipe. Then, ethanol was pressed into the reaction liquid in the pressure vessel to stop the reaction.

After depressurizing the pressure of the pressure vessel and performing degassing, the by-produced polymer (mainly polyethylene) in the reaction solution was separated and removed by a filter to recover the α-olefin low polymer. The results of the composition analysis of the α-olefin low polymer by gas chromatography are shown in Tables 4-5.

Comparative Example 1 A 300 ml autoclave that had been heated and dried in a dryer at 150 ° C. was assembled while hot, and then vacuum nitrogen substitution was performed. A catalyst feed tube equipped with a rupture plate was attached to this autoclave. Charge n-heptane (44 ml), a solution of chromium (III) 2-ethylhexanoate (10 mg, 0.021 mmol) and triethylaluminum (0.400 mmol) dissolved in heptane into the autoclave barrel side. On the other hand, a catalyst feed tube was charged with a heptane solution of 2,5-dimethylpyrrole (0.0650 mmol). The total amount of n-heptane is 50
It was ml.

First, the autoclave was heated to 100 ° C., and then ethylene was introduced at 100 ° C. through the catalyst feed pipe. The rupture disk bursts due to ethylene pressure,
Dimethylpyrrole was introduced into the autoclave barrel side to start low polymerization of ethylene. Total pressure is 35 Kg / cm ²
Ethylene is introduced until the temperature reaches
In cm ² , the temperature was maintained at 100 ° C. After 1 hour, ethanol was pressed into the autoclave to stop the reaction.
Thereafter, the same operation as in Example 1 was carried out to recover the α-olefin low polymer. Table 5 shows the results of composition analysis of the α-olefin low polymer by gas chromatography.

Comparative Example 2 <Production of Cr compound A> 0.815 g of NaH (20.3
15 ml of THF was added to (mmol) and 1.4 ml (20 mmol) of pyrrole dissolved in 5 ml of THF was added dropwise. After stirring at room temperature for 1 hour, the resulting solution was treated with THF2.
1.23 g of CrCl ₂ suspended in 0 ml (10 mmo
It was dripped at l). After the dropping, 5 ml of THF was added, and the mixture was heated under reflux for 20 hours. After filtering off the precipitate, pentane 1 was added to the filtrate.
00 ml was added and the mixture was left standing at 5 ° C. The generated precipitate was separated by filtration and dried to obtain 0.506 g of dark green powder. The content of each element in this powder is Cr: 19.1%, C: 52.3.
%, H: 5.45%, N: 11.6%.

300 m heated and dried in a dryer at 150 ° C.
The 1 autoclave was hot assembled and then vacuum nitrogen purged. In this autoclave, n-heptane (44m
l), triethylaluminum (0.120 mmol)
Was charged into the n-heptane solution described above, and the above Cr compound A (10 mg) slurried in heptane was charged, and after heat treatment at 90 ° C. for 30 minutes, ethylene was introduced. The total amount of n-heptane was 50 ml. After that, the total pressure is 35 Kg / c
in m ^2, and the temperature was maintained at 100 ° C.. After 0.5 hours, the reaction was stopped by pressurizing ethanol into the autoclave. Thereafter, the same operation as in Example 1 was carried out to recover the α-olefin low polymer. Α by gas chromatography
Table 5 shows the results of composition analysis of the olefin low polymer.

In each table, “HP” of solvent type represents n-heptane, “CHX” represents cyclohexane, “Cr-1” of Cr compound type represents chromium (III) acetylacetonate, and “Cr-2” represents Chromium (III) (2,2,6,6-tetramethyl-3,5-heptanedionate), "Cr-
3 "is chromium (III) 2-ethylhexanoate," Cr
-4 "is CrCl ₃ .3pyridine," Cr-
5 "is (CO) ₅ Cr (= CCH ₃ (OCH ₃ )),
“Cr-A” represents the chromium compound synthesized in Comparative Example 2.

In each table, "contact method A" is a method of introducing α-olefin and a chromium compound into a solution containing an amine (pyrrole) and an alkylaluminum compound, and "contact method B" is a chromium compound and A method of introducing α-olefin and an alkylaluminum compound into a solution containing an amine (pyrrole), “contact method C” represents a method of contacting a chromium compound and an alkylaluminum compound with α-olefin after heat treatment, and shows catalytic efficiency. The unit of g-α-olefin / g-chromium compound is
The unit of catalytic activity is g-α-olefin / 1g-chromium · Hr.

[0058]

[Table 1] ──────────────────────────────────── Example 1 2 3 4 Solvent type HP HP HP HP Cr Compound type Cr-1 Cr-1 Cr-1 Cr-1 Cr-1 Cr compound amount (mg / Hr) 56 56 56 56 Cr compound amount (mmol / Hr) (a) 0.164 0.164 0.164 0.164 Pyrrole amount (mmol / Hr) Hr) (b) 0.170 0.340 0.510 0.283 Et ₃ Al amount (mmol / Hr) (c) 4.530 4.530 4.530 2.260 Catalyst component molar ratio (a: b: c) 1: 1: 28 1: 2: 28 1: 3: 28 1: 2: 14 Reaction temperature (℃) 100 100 100 100 Ethylene pressure (Kg / cm ² ) 35 35 35 35 Residence time (Hr) 1.0 1.0 1.0 1.0 Contact method A A A A A <Product amount (g / Hr) > 90.6 87.2 83.2 80.4 <Composition distribution (wt%)> C ₄ 6.0 6.3 6.0 4.5 C ₆ Overall 45.8 45.2 48.6 47.6 1-hexen content in C ₆ (wt%) 94.7 94.2 93.3 94.3 C ₈ 8.0 7.8 7.3 5.5 C _{10 -20 26.2 27.9 22.3 17.7 C 22-30 6.5} 6.7 6.7 6.4 Wax 2.6 2.9 3.4 12.7 byproduct PE 4.9 3.2 5.7 5.6 <catalytic efficiency> 1595 1546 1465 1419 <catalytic activity> 10743 10382 9863 9526 ── ─────────────────────────────────

[0059]

[Table 2] ──────────────────────────────────── Example 5 6 7 8 Solvent type ( Amount: ml) HP HP HP CHX Cr Compound type Cr-2 Cr-3 Cr-3 Cr-3 Cr-3 Cr Compound amount (mg / Hr) 5.6 5.7 5.7 5.7 Cr Compound amount (mmol / Hr) (a) 0.096 0.119 0.119 0.119 Amount of pyrrole (mmol / Hr) (b) 0.283 0.283 0.368 0.368 Et ₃ Al amount (mmol / Hr) (c) 2.260 2.260 2.260 2.260 Catalyst component molar ratio (a: b: c) 1: 3: 24 1: 2: 19 1: 3: 19 1: 3: 19 Reaction temperature (℃) 100 100 100 100 Ethylene pressure (Kg / cm ² ) 35 35 35 35 Residence time (Hr) 1.0 1.0 1.0 1.0 Contact method A A A A A <Product amount (g / Hr)> 55.5 36.8 41.3 67.4 <Composition distribution (wt%)> C ₄ 10.8 9.0 10.1 16.5 C ₆ Overall 58.6 68.7 61.4 50.0 1-hexen content in C ₆ (wt%) 92.2 92.6 92.5 92.4 C ₈ 8.8 7.0 8.2 11.4 C _10-20 20.4 13.4 19.5 21.8 C _22-30 1.0 0.9 0.8 0.4 Wax 0.1 0.0 0.1 0.1 By-product PE 0.3 1.0 0.8 0.2 <Catalytic efficiency> 976 648 736 1189 <Catalytic activity> 11355 6005 6793 10995 ────────────────────────────────────

[0060]

[Table 3] ──────────────────────────────────── Example 9 10 11 12 Solvent type HP HP HP HP Cr Compound type Cr-3 Cr-4 Cr-5 Cr-3 Cr Compound amount (mg / Hr) 5.7 5.7 5.7 5.7 Cr Compound amount (mmol / Hr) (a) 0.119 0.142 0.113 0.119 Pyrrole amount (mmol / Hr) Hr) (b) 0.368 0.425 0.340 0.368 Et ₃ Al amount (mmol / Hr) (c) 23.50 2.890 2.260 2.260 Catalyst component molar ratio (a: b: c) 1: 3: 198 1: 3: 20 1: 3: 20 1: 3: 19 Reaction temperature (℃) 100 100 60 100 Ethylene pressure (Kg / cm ² ) 35 35 35 35 Residence time (Hr) 1.0 1.0 1.0 1.0 Contact method A A A A <Product amount (g / Hr) > 75.3 41.9 10.7 152.8 <Composition distribution (wt%)> C ₄ 13.0 4.6 8.3 10.3 C ₆ overall 66.9 71.8 81.0 60.1 1-hexen content in C ₆ (wt%) 93.1 92.9 94.5 90.1 C ₈ 7.7 4.9 3.7 5.8 C _{10 -20 11.7 16.5 7.0 23.7 C 22-30 0.1} 0.6 0.0 0.1 Wax 0.1 0.1 0.0 0.0 byproduct PE 0.5 1.6 0.1 0.0 <catalytic efficiency> 1335 742 387 2690 <catalytic activity> 12335 5683 1869 25019 ── ─────────────────────────────────

[0061]

[Table 4] ──────────────────────────────────── Example 13 14 15 16 Solvent type HP HP HP HP Cr Compound type Cr-3 Cr-3 Cr-3 Cr-3 Cr-3 Cr Compound amount (mg / Hr) 5.7 200 200 200 Cr Compound amount (mmol / Hr) (a) 0.119 0.420 0.420 0.420 Pyrrole amount (mmol / Hr) Hr) (b) 0.368 1.244 1.244 1.244 Et ₃ Al amount (mmol / Hr) (c) 2.260 2.000 2.000 2.000 Catalyst component molar ratio (a: b: c) 1: 3: 19 1: 3: 5 1: 3: 5 1: 3: 5 Reaction temperature (℃) 100 60 40 30 Ethylene pressure (Kg / cm ² ) 35 35 35 35 Residence time (Hr) 1.0 1.0 1.0 1.0 Contact method B A A A A <Product amount (g / Hr) > 184.0 57.4 41.8 45.2 <composition distribution _{(wt%)> C 4 2.3} 2.4 3.3 4.5 C 6 total 71.6 90.5 92.1 89.0 1-hexen content in _{C 6 (wt%) 92.7 99.2} 99.5 99.4 C 8 1.5 2.2 2.9 3.6 C 10 _-20 18.8 4.6 1.3 1.8 C _22-30 5.7 0.1 0.1 0.1 Wax 0.1 0.1 0.0 0.0 Byproduct PE 0.0 0.3 0.5 1.1 <Catalytic efficiency> 3250 285 211 220 <Catalytic activity> 30111 2761 2015 2176 ─────── ─────────────────────────────

[0062]

[Table 5] ─────────────────────────────── Example Comparison Comparative Example 17 12 Solvent type (amount: ml) HP HP (50) HP (50) Cr compound type Cr-3 Cr-3 Cr-A Cr compound amount (mg / Hr) 200 10 10 Cr compound amount (mmol / Hr) (a) 0.420 0.021-Pyrrole amount (mmol / Hr) (b) 1.659 0.065 − Et ₃ Al amount (mmol / Hr) (c) 2.000 0.400 0.120 Catalyst component molar ratio (a: b: c) 1: 4: 5 1: 3: 19 − Reaction temperature (° C ) 60 100 100 Ethylene pressure (Kg / cm ² ) 35 35 35 Residence time (Hr) 1.0 1.0 1.0 Contact method A C C <Product amount (g / Hr)> 41.5 0.7 0.5 <Composition distribution (wt%)> C ₄ 1.1 3.0 8.5 C ₆ overall 92.6 85.8 78.5 1-hexen content in C ₆ (wt%) 99.6 90.6 85.0 C ₈ 2.5 1.3 0.1 C _10-20 3.1 8.4 0.1 C _22-30 0.1 0.5 0.0 Wax 0.0 0.0 0.0 PE by-product 0.5 1.2 4.9 <Catalyst efficiency> 213 79 62 <Catalyst activity> 2011 724 631 ────────────────────────────────

[0063]

INDUSTRIAL APPLICABILITY According to the present invention described above, a low polymerization product of α-olefin such as 1-hexene can be industrially produced in a high yield and a high selectivity without a complicated operation. Therefore, the industrial value of the present invention is remarkable.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shinji Iwade, 3-10-10, Shiodotsu, Kurashiki-shi, Okayama Mitsubishi Kasei Co., Ltd. Mizushima Plant (56) Reference JP-A-7-165815 (JP, A) JP 50-5048 (JP, B1) (58) Fields investigated (Int.Cl. ⁷ , DB name) C07C 2/30 C07C 11/02-11/113 C10G 50/00 C08F 4/60 C08F 4/69 C08F 10/00 B01J 8/06

Claims (5)

(57) [Claims] 1. A method for producing an α-olefin low polymer using a chromium-based catalyst, wherein a catalyst system comprising at least a combination of a chromium compound and an amine or a metal amide and an alkylaluminum compound is used as the chromium-based catalyst, In the solvent, when the chromium compound and the alkylaluminum compound are not contacted in advance, α-olefin and the chromium-based catalyst are brought into contact with each other to carry out low polymerization of α-olefin, the contact is performed in a plurality of different zones. And a method for producing an α-olefin low polymer. 2. The method for producing an α-olefin low polymer according to claim 1, wherein the α-olefin and chromium compound are introduced into a solution containing an amine or metal amide and an alkylaluminum compound. 3. The method for producing an α-olefin low polymer according to claim 1, wherein the α-olefin and the alkylaluminum compound are introduced into a solution containing a chromium compound and an amine or a metal amide. 4. The method for producing an α-olefin low polymer according to claim 1, wherein a pipe reactor is used as a reaction device. 5. The method for producing an α-olefin low polymer according to claim 1, wherein a multi-stage mixing tank is used as a reaction device.