JPH1087517A - Production of alpha-olefin low grade polymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing an α-olefin low grade polymer excellent in heat conductivity, capable of effectively removing a reaction heat, with high productivity. SOLUTION: This low grade polymerization reaction of an αw1-olefin using a chromium-based catalyst is performed in a tank having a structure in which partition plates 7 are placed orthogonally to an outer face of an inner cylinder 6 at intervals and an outer strip is mounted between tips of the partition plates 7, then a temperature control element 5B having a flowing path of a heating medium is formed, thus the outer strip side of the temperature control element 5B is fixed in opposing to an inner face of the vessel main body.

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 in a high yield and a high selectivity. The present invention relates to an industrially advantageous method for producing an α-olefin low polymer which can be produced with high productivity.

[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-based catalyst comprising a combination of a specific chromium compound and a specific organic aluminum compound is known. For example, Japanese Patent Publication No. 43-187
No. 07 describes a method for obtaining 1-hexene from ethylene using a catalyst system comprising a VIA transition metal compound containing chromium and polyhydrocarbyl aluminum oxide. JP-A-3-128904 discloses a method for trimerizing an α-olefin using a catalyst obtained by previously reacting a chromium compound having a chromium-pyrrolyl bond with a metal alkyl or Lewis acid. Have been described. Further, JP-A-6-239920 discloses that an α-olefin is low-polymerized using a catalyst obtained by mixing a chromium compound, a pyrrole, a metal alkyl compound and a halide source in a common solvent. A method is described.

By the way, a considerable amount of by-product of the polymer cannot be avoided by any of the above-mentioned methods, and this by-product of the polymer is attached to a polymerization reactor or equipment in an industrial operation or a reaction product solution is produced. A problem of polymer removal. Generally, a stirred tank reactor having an outer jacket or an inner jacket is industrially used as a polymerization reactor. However, when the above stirred tank reactor is used for the low polymerization reaction of the α-olefin, a secondary tank is used. The produced polymer adheres to the wall surface of the outer jacket or the inner jacket, particularly to the heat transfer surface of the jacket, and causes a problem that heat removal efficiency is reduced. In order to achieve high productivity in the low polymerization reaction of the α-olefin, it is important to improve the heat removal efficiency of the reaction heat.

[0004] In general, a vessel used for a polymerization reaction on an industrial scale is an outer jacket type vessel as shown in FIG. 7, that is, a vessel main body 1 'is welded to a cylindrical body with plate-shaped end plates welded to both ends thereof. A jacket 20 for removing generated heat or heating the contents while being formed in a pressure-resistant closed container,
A tank container provided outside the container body 1 'is used.

In this type of vessel, in order to maintain the pressure resistance in the vessel body, the vessel thickness is generally increased, the thermal conductivity through the wall of the vessel body is low, and α is an exothermic reaction.
-In low polymerization of olefins, it was difficult to obtain high productivity. Further, when the size of the vessel container is increased, it is necessary to increase the thickness of the wall of the vessel body from the viewpoint of strength, and there is a disadvantage that the thermal conductivity is further reduced.

To solve this disadvantage due to heat conduction, as shown in FIG. 8, partition plates 21 are arranged at right angles to the inner surface of the container body 1 'and are spaced apart from each other. An inner jacket type tank container in which a spiral flow path 23 partitioned by a partition plate 21 is formed between the inner strip 22 and the inner surface of the container body 1 'by straddling the inner strip 22 therebetween. It has been known.

However, the inner jacket type vessel has excellent thermal conductivity, but has a large number of welds between the inner strips 22 on the inner surface of the vessel in contact with the contents during the low polymerization reaction of α-olefin. There are disadvantages due to being exposed. In other words, the welded portion is
Inevitably, the surface roughness is rough and there is a weld defect, but in the low polymerization reaction of α-olefin, if the surface of the contact portion of the reaction mixture (hereinafter referred to as a liquid contact portion) is rough,
The by-product polymer tends to adhere. In addition, in order to prevent the adhesion of the by-product polymer, the cost of manufacturing and maintaining the equipment is extremely high, such as the need to extremely smooth a large number of welding lines and to introduce a special adhesion prevention or removal technique. There is a disadvantage that it becomes larger.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to produce an α-olefin low polymer with high productivity by using a tank vessel which has solved the disadvantages while taking advantage of the above-mentioned inner jacket system. It is an object of the present invention to provide a method which can be performed by using a specific vessel.

[0009]

That is, the gist of the present invention is as follows.
When the α-olefin is subjected to a low polymerization reaction in the reaction medium using a chromium-based catalyst, the low polymerization reaction is performed by arranging partition plates at right angles to the outer surface of the inner cylinder at intervals, and between the ends of the partition plates. By straddling the outer strip, a flow path wall (hereinafter, referred to as a “temperature control element”) having a flow path of a heat medium partitioned by a partition plate is formed between the inner cylinder and the outer strip. A method for producing an α-olefin low polymer, characterized in that the conditioning element is carried out in a vessel having a structure in which the outer strip side is fixed to the inside of the vessel body with the outer strip side facing the inner surface of the vessel body.

Another gist of the present invention is that when the α-olefin is subjected to a low-polymerization reaction in a reaction medium using a chromium-based catalyst, the low-polymerization reaction is carried out by placing a temperature control element in an outer strip side in a container body. Having a structure in which a gap chamber is formed by fixing the gap between the outer strip side of the temperature control element and the inner surface of the container body, and fixing the gap at an interval facing the inner surface of the container body. A process for producing an α-olefin low polymer, which is carried out in a container.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. (Tank container) Tank container body The temperature-adjusting element type tank container used in the method of the present invention has the following structure. (1) Embodiment-1 As shown in FIGS. 1 to 3, the partition plate 7 is perpendicular to the outer surface of the inner cylinder 6.
Are arranged in parallel at intervals, and the outer strip 8 is straddled between the ends of the partition plate 7, whereby the flow path of the heat medium partitioned by the partition plate 7 between the inner cylinder 6 and the outer strip 8 is provided. Forming a flow path wall (temperature control element) 5A (5B) having 9;
The temperature control element 5A (5B) is fixed to the inner surface of the container body 1 by the outer strip 8, that is, the inner surface of the body 2 of the container body 1 and (if necessary) the bottom mirror plate 3 in contact with the heat exchange material. Things can be used.

To fix the temperature control element 5A (5B), the upper end of the temperature control element is set to the position shown in FIG. 1A by, for example, fixing a lug provided on the temperature control element or by direct welding (continuous or intermittent). The lower end is connected to the cylindrical body 2 as shown, and the lower end thereof is connected to the bottom mirror plate 3 around the tank nozzle 12 as shown in FIG. Just do it. When stirring is performed from the lower portion of the tank container, a stirring shaft is often installed at a position corresponding to the tank container nozzle 12 in FIG. 1 and the like. May be connected and fixed.

(2) Embodiment-2 As shown in FIGS. 4 to 6, the partition plate 7 is perpendicular to the outer surface of the inner cylinder 6.
Are arranged in parallel at intervals, and the outer strip 8 is straddled between the ends of the partition plate 7, whereby the flow path of the heat medium partitioned by the partition plate 7 between the inner cylinder 6 and the outer strip 8 is provided. 9 is formed, the outer diameter of the temperature control element 5A (5B) is formed smaller than the inner diameter of the tank container, and the outer strip 8 side of the temperature control element is set to the inner surface of the container body 1. It is fixed at an interval facing the.

The temperature control element 5A (5B) is preferably fixed so that its center line substantially coincides with the center line of the container. At this time, the inner surface of the container body and the outer surface of the temperature control element (ie, the outer surface) A gap corresponding to the difference between the two diameters is formed between the first and second strips), and is substantially uniform in the circumferential direction. As shown in FIG. 4, the lower end of the temperature control element may be directly fixed to the bottom end plate 3 around the tank nozzle 12 by continuous welding or the like, or may be fixed via a partition.

At the upper end of the temperature control element, a partition 13 is usually fixed to the cylindrical body 2 or the upper end plate 4 of the container. Since there is a gap between the outer surface of the temperature control element 5A (5B) fixed inside the container body 1 and the inner surface of the container body 1, the upper and lower portions of the gap are connected by, for example, direct welding or partition walls. The gap chamber is formed by sealing with a space 13 or the like. This can prevent the reaction mixture from penetrating into the above-mentioned gaps and the accompanying formation of scale adhesion. It is preferable to provide an expansion and contraction absorbing portion capable of absorbing expansion and contraction of the temperature control element due to heat in the partition walls and the like for sealing the upper and / or lower portions of the gap. It is necessary to have strength enough to withstand the temperature and pressure normally used in the polymerization.

Further, in order to prevent the temperature control element and the welding for sealing the upper and lower portions of the gap between the element and the container body and the partition from being destroyed by reaction pressure or the like, the inner surface of the container body (usually the top end plate) is used. For the sake of security, it is preferable that the internal pressure of a space (hereinafter, referred to as “main chamber”) surrounded by the inner cylinder of the temperature control element and the internal pressure of the gap chamber be substantially the same. In this case, the pressure resistance of the partition walls as described above is not required. In this case, it is preferable that the difference between the internal pressure of the main chamber and the internal pressure of the gap chamber is 1 kg / cm ² or less, more preferably 0.7 kg / cm ² or less.

As a method for making the main chamber and the gap chamber have substantially the same pressure, for example, a method using a pressure balance mechanism 15 (in which a balance piston 17 is installed in a communication pipe 16) as shown in FIG. The communication pipe 16 ₁ as shown in FIG.
Or a method of detecting the internal pressure of the main chamber and the gap chamber and adjusting the pressure in the gap chamber by a separately installed pressurizing / depressurizing device so as to be substantially equal to the internal pressure of the main chamber. There are no particular restrictions, and these may be used in combination.

The flow path of the heat medium in the temperature control element 5A (5B) may be spiral as shown in FIGS. 1 and 4, or as shown in FIG. 3 and FIG. May have a spiral shape, and the container body may have a meandering shape in the circumferential direction, and is not particularly limited. As the heat medium flowing through the flow path, steam, hot water, or the like is used for heating, and room temperature water such as industrial water, water cooled by a separate refrigerator, a refrigerant such as ethylene glycol, chlorofluorocarbon, or the like is used for cooling. Can be used, but none of them is particularly limited.

The thickness of the inner cylinder 6 depends on the required strength and the interval between the partition plates 7. However, since the interval between the partition plates 7 is smaller than the body length of the container body 1, the thickness of the inner cylinder 6 is small. The plate thickness can be reduced. The surface of the inner cylinder 6 is preferably smooth from the viewpoint of preventing scale adhesion. In order to smooth the surface, methods such as bubbling and electrolytic polishing, which are usually carried out industrially, can be used. Further, the surface roughness is usually not more than 10 μm in Rmax, preferably 3 μm.
m or less, more preferably 1 μm or less. The measurement of Rmax may use the method specified in JIS B0601.

[0020] Attached equipment to the vessel vessel. A vessel vessel (low polymerization reaction vessel) used in the method of the present invention.
There are no particular restrictions on the shape of the stirring blades, baffles, and the like, which are auxiliary equipment, and equipment and equipment generally used in various organic reactions and polymerization reactions can be used.

Chromium-based catalyst The chromium-based catalyst used in the α-olefin low polymerization reaction of the present invention is a catalyst comprising at least a combination of a chromium compound (a), a nitrogen-containing compound (b) and an alkylaluminum compound (c). It is preferred to use a system. As a more preferred embodiment, a catalyst system comprising a combination of a chromium compound (a), a nitrogen-containing compound (b), an alkylaluminum compound (c) and a halogen-containing compound (d) is used.

Chromium compound (a) As the chromium compound (a) used in the present invention, a compound represented by the general formula CrXn is used. However, in the general formula, X is 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, 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.
Oxygen, halogen and the like can be mentioned.

Preferred chromium compounds are chromium alcohols.
Xylate, carboxyl group, β-diketoner salt, β-keto
Ester salt with anion or chromium halide
And specifically, chromium (IV) -t-butoxy
De, chromium (III) acetylacetonate, chromium (III)
Trifluoroacetylacetonate, chromium (III) hex
Safluoroacetylacetonate, chromium (III) (2,
2,6,6-tetramethyl-3,5-heptanedioner
G), Cr (PhCOCHCOPh)_Three, Chrome (II)
Acetate, chromium (III) acetate, chromium (III)-
2-ethylhexanoate, chromium (III) benzoate
Chromium (III) naphthenate, Cr (CH _ThreeCOCH
COOCH_Three)_ThreeChromic chloride, chromic chloride,
Chromium bromide, chromium bromide, chromium iodide,
Chromium iodide, chromium fluoride, chromium fluoride
And the like. (However, Rh represents a phenyl group.
You. ) It also consists of the above chromium compound and an electron donor
Complexes can also be suitably used. As an electron donor
Is any of the compounds containing nitrogen, oxygen, phosphorus or sulfur
Selected from

Of a complex comprising a chromium compound and an electron donor
Examples include chromium halide ether complexes,
Complex, ketone complex, aldehyde complex, alcohol complex
, Amine complex, nitrile complex, phosphine complex, thio
Ether complexes and the like. Specifically, CrCl
_Three・ 3THF, CrCl_Three・ 3DOX, CrCl_Three・
(CH_ThreeCO_Two-N-C_FourH₉), CrCl_Three・ (CH
_ThreeCO_TwoC_TwoH_Five), CrCl_Three・ 3 (i-C_ThreeH₇O
H), CrCl_Three・ 3 [CH_Three(CH_Two)_ThreeCH (C_Two
H_Five) CH_TwoOH], CrCl_Three・ 3PRD, CrCl
_Three・ 2 (i-C_ThreeH ₇NH_Two), [CrCl_Three・ 3CH
_ThreeCN] ・ CH_ThreeCN, CrCl_Three・ 3PPh_Three, Cr
Cl_Two・ 2THF, CrCl_Two・ 2PRD, CrCl_Two
・ 2 [(C_TwoH_Five)_TwoNH], CrCl_Two・ 2CH_ThreeC
N, CrCl_Two・ 2 [P (CH_Three)_TwoPh] and the like
It is. (However, THF is tetrahydrofuran, DOX
Represents dioxane and PRD represents pyridine.
You. )

As the chromium compound, it can be used in hydrocarbon solvents.
Soluble compounds are preferred, β-diketonate salts of chromium,
Carboxylates, salts of β-ketoesters with anions, β
-Ketocarboxylates, amide complexes, carbonyl complexes,
Ruben complex, various cyclopentadienyl complexes, alkyl
Complexes, phenyl complexes and the like. Various types of chrome
Rubonyl complex, carbene complex, cyclopentadienyl complex
, Alkyl complex and phenyl complex
Is Cr (CO)₆, (C₆H₆) Cr (CO) _Three,
(CO)_FiveCr (= CCH_Three(OCH_Three)), (CO)
_FiveCr (= CC₆H _Five(OCH_Three)), CpCrC
l_Two, (Cp * CrClCH_Three)_Two, (CH_Three) _TwoCr
Cl and the like are exemplified. (However, Cp is cyclopentadie
Cp * is pentamethylcyclopentadienyl
The groups represent each. )

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. 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 (the total amount of the carrier and the catalyst component) due to the use of the carrier can be avoided.

Nitrogen-containing compound (b) As the nitrogen-containing compound (b) used in the present invention, one or more compounds selected from the group consisting of amines, amides and imides are used. As the amine used in the present invention, 1
Grade or secondary amines are used. Examples of the primary amine include ethylamine, isopropylamine, cyclohexylamine, benzylamine, aniline, and naphthylamine. Examples of the secondary amine 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-
Examples include tetrachloropyrrole, 2-acetylpyrrole, pyrazole, pyrrolidine and the like.

The amide used in the present invention includes a metal amide derived from a primary or secondary amine. For example, the above-mentioned primary or secondary amine and the IA group,
Amides obtained by reaction with metals selected from Group IIA, IIIB and IVB. Specific examples of such a metal amide include lithium amide, sodium ethylamide, calcium diethylamide, lithium diisopropylamide, potassium benzylamide, sodium bis (trimethylsilyl) amide, lithium indolide, sodium pyrrolide, lithium pyrrolide, and potassium pyrrolide. , Potassium pyrrolidide, aluminum diethylpyrrolidide, ethylaluminum dipyrrolide, aluminum tripyrolide and the like.

In the present invention, the above-mentioned secondary amine,
Metal amides derived from secondary amines or mixtures thereof are preferably used. In particular, as the secondary amine, pyrrole, 2,5-dimethylpyrrole, 3,4-dimethylpyrrole, 3,4-dichloropyrrole, 2,3,3
As metal amides derived from 4,5-tetrachloropyrrole, 2-acetylpyrrole and secondary amine,
Aluminum pyrrolide, ethylaluminum dipyrrolide, aluminum tripyrolide, sodium pyrrolide,
Lithium pyrrolide and potassium pyrrolide are preferred. And, among the pyrrole derivatives, derivatives having a hydrocarbon group on the pyrrole ring are particularly preferred.

Examples of the amide or imide compound other than the above used in the present invention include compounds represented by the following general formulas (1) to (3).

[0032]

Embedded image

In the general formula (1), M ¹ is a hydrogen atom or a metal element selected from Groups IA, IIA and IIIB of the periodic table, and R ¹ is a hydrogen atom, an alkyl having 1 to 30 carbon atoms. 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, wherein R ² is a hydrogen atom,
30, an alkyl group, 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 (the definition of R ³ is the same as R ^1, R ¹ and may be different) represents, R ¹ and R ² may form a ring.

In the general formula (2), M ² and M ³ are a hydrogen atom or a metal element selected from Groups IA, IIA and IIIB of the periodic table, and R ⁴ and R ⁵ are a hydrogen atom, a carbon atom Number 1
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, wherein R ⁴ and R ⁵ form a ring; A may represent an alkylene group which may contain an unsaturated bond.

In the general formula (3), M ⁴ is a hydrogen atom or a metal element selected from Groups IA, IIA and IIIB of the periodic table, and R ⁶ is a hydrogen atom, an alkyl having 1 to 30 carbon atoms. 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, wherein R ⁷ is a hydrogen atom,
30, an alkyl group, an alkenyl group, an aralkyl group, an aryl group which may have a substituent, an aryl group which may contain a hetero element, or a SO ₂ R ⁸ group (R ⁸ is defined as R ⁶ The same and may be different from R ⁶ )
And R ⁶ and R ⁷ may form a ring.

The amides represented by the general formula (I) or (2) include, for example, acetamide, N-methylhexaneamide, succinamide, maleamide, N-methylbenzamide, imidazole-2-carboxamide, di-amide Examples include 2-thenoylamine, β-lactam, δ-lactam, ε-caprolactam, and salts thereof with metals of Groups IA, IIA or IIIB of the periodic table. Examples of the imides include 1,2-cyclohexanedicarboximide, succinimide, phthalimide,
Maleimide, 2,4,6-piperidinetrione, perhydroazecin-2,10-dione, and salts of these with metals of Groups IA, IIA or IIIB of the periodic table.

The sulfonamides and sulfonimides represented by the general formula (3) include, for example, benzenesulfonamide, N-methylmethanesulfonamide, N-
Methyl trifluoromethanesulfonamide, and salts thereof with metals of Groups IA, IIA or IIIB of the Periodic Table. Among these amide or imide compounds, compounds represented by the general formula (1) are preferable, and particularly,
An imide compound in which R ² in the general formula (1) represents an acyl group C (＝ O) R ³ and R ¹ and R ² form a ring is preferable.

Alkyl aluminum compound (C) Alkyl aluminum compound (c) used in the present invention
An alkylaluminum compound represented by the following general formula (4) is preferably used.

[0039]

## STR2 ## _{^{R 1 m Al (OR 2)}} n H p X q ... (4)

In the general formula (4), R ¹ and R ² are hydrocarbon groups having usually 1 to 15, preferably 1 to 8 carbon atoms, which may be the same or different from each other. Represents a halogen atom, m, n, p and q are each 0 <m
≦ 3, 0 ≦ n <3, 0 ≦ p <3, and 0 ≦ q <3, where m + n + p + q = 3.

Examples of the above alkylaluminum compound include a trialkylaluminum compound represented by the following general formula (5), an alkylaluminum halide compound represented by the following general formula (6), and an alkoxyaluminum compound represented by the following general formula (7). Aluminum compounds, alkyl aluminum hydride compounds represented by the general formula (8), and the like can be given. The meanings of R ¹ , X and R ² in each formula are the same as described above.

[0042]

Embedded image _{^{R 1 3 Al ... (5)}} R 1 m Alx 3-m (M is 1.5 ≦ m <3) ... ( 6) R 1 m Al (OR 2) 3-m (m is 0 < m <3, preferably 1.5 ≦ m <3) (7) R ¹ _m AlH _3-m (8) (m is 0 <m <3, preferably 1.5 ≦ m <3)

Specific examples of the above alkylaluminum compound include trimethylaluminum, triethylaluminum, triisobutylaluminum, diethylaluminum monochloride, diethylaluminum ethoxide, diethylaluminum hydride and the like. Of these, trialkylaluminum is particularly preferred in that it produces less polymer by-products. The alkylaluminum compound may be a mixture of two or more.

Halogen-Containing Compound (d) The catalyst used in the present invention is preferably formed essentially of the above-mentioned three components. In addition to these three components, the halogen-containing compound (d) is used for preparing the catalyst. Is more preferred. The halogen-containing compound (d) may be any compound containing a halogen atom, but the following halogen-containing compounds (1) to (4) are preferred.

The halogen-containing compound (1) is represented by the following formula:
It is a halogen-containing compound containing an element selected from Group IIIA, IIIB, IVA, IVB, VA, VB, and VIB. Specifically, 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, antimony pentachloride, bismuth trichloride, boron tribromide, aluminum tribromide, tetra Examples thereof include carbon bromide, bromoform, bromobenzene, iodomethane, silicon tetrabromide, hexafluorobenzene, and aluminum fluoride. 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. As the halogen of the halogen-containing compound (1), it is preferable to use bromine or chlorine, especially chlorine in view of the activity, selectivity of the target product, and the like. Particularly preferable halogen-containing compound (1) is carbon tetrachloride, Chloroform, dichloroethane, titanium tetrachloride, germanium tetrachloride, tin tetrachloride. A mixture of two or more of these can also be used. Halogen-containing compound (2)
Is a straight-chain hydrocarbon having 2 or more carbon atoms substituted with 3 or more halogen atoms. Halogen-containing compound (2)
As the straight chain hydrocarbons in the above, straight chain saturated hydrocarbons are preferable, and straight chain hydrocarbons in which two or more adjacent carbon atoms are substituted with three or more halogen atoms are preferable.

As the halogen in the halogen-containing compound (2), it is preferable to use chlorine or bromine, especially chlorine in view of the activity, selectivity of the target product and the like. As the halogen-containing compound (2), specifically,
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,
Examples thereof include 1-tribromoethane and 1,1,2,2-tetrabromoethane. Among these, in particular,
1,1-Trichloroethane, pentachloroethane, hexachloroethane, 1,1,2,2-tetrachloroethane are preferred.

The use of the halogen-containing compound (2) has the advantage that not only the catalytic activity and the selectivity of the trimer can be remarkably improved, but also the deterioration of the catalyst with time 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. It is preferable to use chlorine or bromine as the halogen atom, especially chlorine in view of the activity, selectivity of the target product and the like.

Among the halogen-containing compounds (3), in particular, 1,2,3-trichlorocyclopropane, pentachlorocyclopropane, 1,2,3,4-tetrachlorocyclobutane, 1,2,3,4,5 -Pentachlorocyclopentane, 1,2,3,4,5,6-hexachlorocyclohexane are 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) has the following general formula (9)
It is a compound represented by these.

[0049]

Embedded image

In the general formula (9), 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. It is preferable to use chlorine or bromine as the halogen, especially chlorine in view of activity, selectivity of the target product, and the like. Specific examples of the halogen-containing compound (4) include allyl chloride, 3,3-dichloro-1-propene, 3-chloro-1-butene, 3,3-dichloro-1-butene, and 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,
Examples thereof include 1-chloro-2-pentene and 1,1-dichloro-2-pentene, 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 trimerization, but also uses a small amount of the halogen-containing compound because the activity per halogen atom is high. 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), Trispenta
Fluorophenylboron (B (C₆F_Five)_Three), Trif
Fluoromethanesulfonic acid (CF _ThreeSO_ThreeH), Hexaf
Fluoroisopropanol ((CF_Three)_TwoCHOH) etc.
It can be suitably used.

In the present invention, preferably, each of the above-mentioned catalyst components (a) to (c), more preferably (a) to (d)
Is carried out in a liquid reaction medium using a chromium-based catalyst prepared from the above. When a chromium compound containing a halogen, such as chromic chloride, is used as the chromium compound (a), the chromium compound also functions as the halogen-containing compound (d).
Similarly, when an alkylaluminum compound containing a halogen such as diethylaluminum monochloride is used as the (c) alkylaluminum compound (c), the alkylaluminum compound also functions as the halogen-containing compound (d). I do.

Α-Olefin In the present invention, the starting α-olefin to be subjected to the low polymerization reaction includes a substituted or unsubstituted α-olefin having 2 to 30 carbon atoms.
Olefins are used. Specifically, ethylene, propylene, 1-butene, 1-hexene, 1-octene, 3
-Methyl-1-butene, 4-methyl-1-pentene and the like. In particular, ethylene is preferable as the raw material α-olefin, and according to the present invention, 1-hexene, a trimer thereof, can be obtained from ethylene with high yield and high selectivity.

Reaction Solvent In the present invention, the reaction solvent may be a chain having 1 to 20 carbon atoms such as butane, pentane, 3-methylpentane, hexane, heptane, 2-methylhexane, octane, cyclohexane, methylcyclohexane, decalin and the like. Saturated or alicyclic saturated hydrocarbons, aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, mesitylene, and tetralin are used. These can be used alone or as a mixed solvent. In the present invention, the α-olefin itself as a reaction raw material or another olefin may be used as the solvent. When an olefin is used as the solvent, it is preferable to use a liquid at room temperature. Particularly preferred as the solvent are those having 4 to 7 carbon atoms.
Is a chain saturated hydrocarbon or alicyclic saturated hydrocarbon.
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.

Catalyst Preparation The catalyst used in the low polymerization reaction of the present invention is preferably a chromium compound (a), a nitrogen-containing compound (b) selected from amines, amides and imides, an alkylaluminum compound (c), and more preferably Is a halogen-containing compound (d)
The chromium compound (a) and the alkylaluminum compound (c) are preferably contacted in this case in the presence of an α-olefin. That is, each of the chromium compound (a) and the alkylaluminum compound (c) may be brought into contact with the nitrogen-containing compound (b) or the halogen-containing compound (d) in advance, but both may be in the presence of an α-olefin. Contact for the first time. When the catalyst is prepared in this way, there are advantages that the catalytic activity is remarkably improved, the selectivity of the trimer is very high, and the purity of the obtained α-olefin low polymer is also extremely high.

The method for preparing the catalyst in the present invention will be described in more detail. The catalyst is preferably (a) to (c),
More preferably, it is prepared by mixing the components of (d) at 20 to 150 ° C., preferably 50 to 100 ° C., but may be prepared in advance and supplied to the reaction zone, or used for catalyst preparation. The components (a) to (d) may be supplied to a reaction zone to generate a catalyst in situ. In either case, the preparation of the catalyst is carried out as described in (a) above.
The chromium compound and the (c) alkylaluminum compound are contacted for the first time in the presence of an α-olefin. The reason that a high-performance catalyst is produced by this embodiment is that the reactant produced by contact between the chromium compound (a) and the alkylaluminum compound (c) is extremely unstable and easily decomposes as it is. It is considered that the presence of the α-olefin causes coordination of the α-olefin with the α-olefin, and the reaction product is appropriately stabilized.

In the low polymerization reaction of the α-olefin according to the present invention, the α-olefin, the alkylaluminum compound, the chromium compound and other catalyst components are continuously supplied using the above-mentioned temperature-controlled element type vessel. Then, a low polymerization reaction of an α-olefin is carried out under the following reaction conditions (reaction temperature and reaction pressure, etc.). The supply of each catalyst component into the reaction zone of the vessel was carried out by converting the chromium compound and the alkyl aluminum compound into α-
Any method may be used as long as the contact is made for the first time in the presence of the olefin, and an example of the supply method is shown below.

(1) A solution containing a chromium compound (a), a solution containing a nitrogen-containing compound (b) and an alkylaluminum compound (c) and a halogen-containing compound (d), and a method of supplying an α-olefin to the reaction zone, respectively. (2) A method including supplying a solution containing a chromium compound (a), a nitrogen-containing compound (b) and a halogen-containing compound (d), a solution containing an alkylaluminum compound (c), and an α-olefin to a reaction zone. (3) A method including supplying a solution containing a chromium compound (a) and a halogen-containing compound (d), a solution containing a nitrogen-containing compound (b) and an alkylaluminum compound (c), and an α-olefin to the reaction zone. (4) A method including supplying a solution containing a chromium compound (a) and a nitrogen-containing compound (b), a solution containing an alkylaluminum compound (c) and a halogen-containing compound (d), and an α-olefin to the reaction zone. (5) A method in which a chromium compound (a), a nitrogen-containing compound (b), an alkylaluminum compound (c), a halogen-containing compound (d), and an α-olefin are respectively supplied to a reaction zone.

The amount of the chromium compound (a) supplied to the reaction zone is 2 × 10 ⁻² mmol or less, preferably 1 × 10 ⁻⁵ to 1 × 10 ⁻⁷ mmol, per liter of the reaction medium. The molar ratio of each catalyst component supplied to the reaction zone is usually (a) :( b) :( c) :( d) = 1:
0.1-100: 0.1-500: 0.1-100, preferably (a) :( b) :( c) :( d) = 1: 1-1
The range is from 0: 5 to 50: 1 to 10.

Further, as the supply amount of the α-olefin,
In order to improve the catalytic activity and the selectivity of the target product, it is desirable to use a high concentration of α-olefin.
Specifically, the concentration of α-olefin in the reaction solvent is usually 5 to 100 mol%, preferably 10 to 100 mol%.
%, Particularly preferably 20 to 100 mol%,
It is desirable to contact the chromium-based catalyst with an α-olefin. In particular, when a low-boiling α-olefin such as ethylene is used as the α-olefin, the α-olefin pressure is usually about 3 to 250 kg / cm ² , preferably about 5 to 250 kg / cm ² .
100 kg / cm ² , more preferably about 5 to 50 kg / cm ²
The contact is preferably performed under the condition of cm ² . By contacting under such conditions, low polymerization of α-olefin can be performed without going through a catalyst preparation step.

The conditions for the low polymerization reaction of the α-olefin in the reaction zone in the present invention are, for example, a reaction temperature of usually 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 ,
Preferably, the pressure is about 5 to 100 kg / cm 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 . Separation and removal of the by-product polymer in the reaction solution are appropriately performed using a known solid-liquid separation device, and the recovered α-olefin low polymer is purified if necessary. For purification, distillation purification is usually employed,
In the present invention, the target component can be recovered with high purity because the amount of the halogen-containing compound used is small and the decomposition products are small. According to the present invention, 1-hexene of high purity can be industrially advantageously produced particularly from ethylene.

[0064]

EXAMPLES Next, specific embodiments of the present invention will be described with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof. Example 1 Inner wall (surface of inner cylinder of temperature control element) of tank vessel of temperature control element type shown in FIG.
5.6 from a catalyst supply pipe into one of stainless steel temperature control element type tank vessels equipped with a stirrer having an Rmax of about 1.2 μm by electrolytic polishing.
mmol / hr, 37.4 m of triethylaluminum
mol / hr, and 3.74 mmol of hexachloroethane
Each was fed as an n-heptane solution at a feed rate of 1 / hr. From the other catalyst supply tube, 0.93 mm of chromium (III) -2-ethylhexanoate was added together with ethylene.
ol / hr (0.44 g / hr) was continuously fed as an n-heptane solution. The total supply of n-heptane to the vessel is 150 l / hr. The vessel was kept at 80 ° C., and ethylene was fed at a total pressure of 35 kg / cm ^2.
G was continuously supplied so as to cause a low polymerization reaction of ethylene. The 1-hexene was continuously produced by a low-polymerization reaction of ethylene while the reaction solution was withdrawn from the vessel via a reaction solution withdrawing tube so that the internal solution volume was maintained at 150 liters. After the operation was continued for a long time, unreacted ethylene was recovered, the reaction product liquid was extracted, the vessel was opened, and the state of adhesion of the polymer to the inner wall of the vessel was observed. Table 1 shows the results. Table 1 also shows the catalyst efficiency (g-1-hexene / g-chromium) during operation and the polyethylene by-product rate.

Comparative Example 1 A low-polymerization reaction of ethylene was carried out under the same conditions as in Example 1 except that the type of the vessel was the internal jacket type shown in FIG. 8, and the same evaluation was carried out. Table 1 shows the results.

[0066]

[Table 1]

[0067]

According to the present invention, the low polymerization reaction of the α-olefin is carried out by using a temperature control element type vessel in the same manner as in the inner jacket type, so that the plate for separating the contents and the refrigerant during the low polymerization can be formed. Since the thickness can be reduced, the heat conductivity is excellent, the reaction heat can be effectively removed, and the α-olefin low polymer can be produced with high productivity. Further, in the method of the present invention, the proportion of the welded portion occupying the inner surface of the tank vessel is small, so that the adhesion of the polymer polymer is reduced, and the low polymerization reaction of α-olefin can be performed continuously for a long time. is there.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an example of a tank container used in the method of the present invention.

FIG. 2 is an enlarged view of a main part of FIG. 1;

FIG. 3 is a longitudinal sectional view showing another example of a tank container used in the method of the present invention.

FIG. 4 is a longitudinal sectional view showing still another example of the tank container used in the method of the present invention.

FIG. 5 is an enlarged view of a main part of FIG. 4;

FIG. 6 is a longitudinal sectional view showing still another example of a tank container used in the method of the present invention.

FIG. 7 is a longitudinal sectional view showing an example of a conventional tank container.

FIG. 8 is an enlarged sectional view of a main part showing another example of a conventional tank container.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Container main body 2 Cylindrical trunk part 3 Bottom end plate 4 Top end plate 5A, 5B Temperature control element 6 Inner cylinder 7,21 Partition plate 8 Outer strip 9,23 Heat medium channel 10 Heat medium channel inlet 11 Heat medium channel outlet DESCRIPTION OF SYMBOLS 12 Tank container nozzle 13 Partition wall 14 Gap chamber 15 Pressure balance mechanism 16, 16 ₁ Communication pipe 17 Balance piston H Gap 20 Outer jacket 22 Inner strip

Claims (3)

[Claims] When a low-polymerization reaction of an α-olefin is carried out in a reaction medium using a chromium-based catalyst, the low-polymerization reaction is carried out by arranging partition plates at right angles to an outer surface of an inner cylinder at intervals.
A channel wall (hereinafter, referred to as a "temperature control element") having a flow path of a heat medium partitioned by the partition plate between the inner cylinder and the outer strip by straddling the outer strip between the distal ends of the partition plates. And forming the temperature control element in a vessel having a structure in which the outer strip is fixed to the inside of the vessel body with the outer strip side facing the inner surface of the vessel body. 2. A low-polymerization reaction of an α-olefin in a reaction medium using a chromium-based catalyst, the low-polymerization reaction is performed by arranging partition plates at right angles to the outer surface of the inner cylinder at intervals.
A channel wall (hereinafter, referred to as a "temperature control element") having a flow path of a heat medium partitioned by the partition plate between the inner cylinder and the outer strip by straddling the outer strip between the distal ends of the partition plates. The temperature control element is fixed in the container body with the outer strip side facing the inner surface of the container body at an interval, and a gap between the outer strip side of the temperature control element and the inner surface of the container body is formed. A process for producing an α-olefin low polymer, wherein the process is carried out in a vessel having a structure in which a gap chamber is formed by sealing the upper and lower portions. 3. The process for producing an α-olefin low polymer according to claim 1, wherein the low polymerization reaction is a process for trimerizing ethylene to obtain a product mainly composed of 1-hexene.