Method for producing low alpha olefin polymer

Abstract

An object of the present invention is to provide a method for suppressing precipitation of high-concentration polymers dissolved in a solvent in the finishing step and suppressing clogging of the apparatus by polymers even when high-concentration polymers precipitate. The present invention relates to a method for producing a low-alpha olefin polymer comprising a production step and a finishing step, wherein the position of the liquid supplied to the distillation column in the finishing step is lower than the position of the liquid supplied to the distillation column in the production step.

Description

Description of the invention Title of the invention Method for producing low alpha olefin polymer Field of invention

[0001] This invention relates to a method for producing a low alpha olefin polymer. A low alpha olefin polymer is a useful material that is widely used as a raw material for a monomer for an olefinic polymer, as a comonomer for various polymers, and also as a raw material for plasticizers, surfactants, lubricating oils, etc. In particular, 1-hexene to be produced through the polymerization reaction of ethylene is useful as a raw material for linear low density polyethylene. History of the invention

[0002] A low alpha olefin polymer is produced by subjecting a crude alpha olefin to a low polymerization reaction in the presence of a catalyst such as a homogeneous catalyst and a solvent, but in this case the resulting polymers such as polyethylene depend on the reaction system such as a reactor.

[0003] Patent Document No. 1 discloses a method of carrying out a reaction under conditions where the polymer is in a granular form, centrifuging the reaction liquid containing the granular polymers to separate the solid, and discharging the separated solid with a rotating screw out of the system. Patent Document 2 describes a method of operation such that the temperature of the reaction liquid in the process lines where polymers are present is controlled to a temperature range in which adhesion and precipitation of the polymers do not occur. Patent Document 3 discloses dissolving in a solvent in a pressure space lower than the partial pressure of the alpha olefin material during the low polymerization reaction to effectively remove polymers adhering to the alpha olefin low polymerization reaction equipment. Prior knowledge documents

[0004] Patent document [Patent document 1] JP-A-7-149671 [Patent document 1] JP-A-2003-261602 [Patent document 1] JP-A-2013-170135 Summary of the invention Problems that this invention should solve

[0005] However, in the method described in Patent Document 1, there is no method for separating polymers dissolved in the solvent, and this method requires a solid-liquid viscous separation device, and the construction costs increase. In the method described in Patent Document 2, when the purpose is to maintain the process at a temperature where polymers do not precipitate, this becomes a limitation for the optimal design such as a distillation column, and the construction costs increase. Also, adhesion and loading of polymers are inevitable, but any countermeasures are not generally disclosed at that time. Patent Document 3 does not have an efficient cleaning process that can discharge polymers from the process without clogging.

[0006] In an industrial production method of low-alpha olefin polymer, there is a case where polymers are formed as by-products, they are not dissolved in the solvent for precipitation, and they mostly stick to the reactor, heat exchanger, and the like. It is also important to prevent polymers from being produced as by-products and polymers from being precipitated, but there is a case where polymers are inevitably produced as by-products and precipitated. For example, in the termination stage of the operation, polymers may inevitably precipitate.

[0007] In the industrial production method of low-L-olefin polymer, even when the polymers precipitate, it is desirable that they be discharged from the process without sticking to the production apparatus or that the polymers be discharged from the process without clogging the production apparatus when the polymers are slightly stable. Accordingly, the present invention has been made in view of the above circumstances. That is, an object of the invention is to provide a method for suppressing precipitation of polymers dissolved in a solvent at a high concentration in the termination stage of the operation, and to provide a method for inhibiting clogging of the apparatus by the polymer in the low alpha olefin polymer production apparatus even when the polymers are dissolved in the solvent at a high concentration due to a temperature drop or the like.

[0008] In addition, another object of the invention is to provide a suitable and efficient separation method of polymers. Furthermore, another object of the present invention is to provide a convenient and efficient cleaning method of a reactor and / or a heat exchanger. Ways to solve the problem

[0009] As a result of extensive studies, the present inventors have found that the above problems can be solved by adjusting the position of the source liquid supply to the distillation column in the termination stage of the operation in which a solvent is supplied between a reactor and the distillation column, especially at the time of cleaning after the termination of the reaction, to a position lower than the position of the prepared liquid supply to the distillation column in the production operation stage, that is, when the stable low alpha olefin polyliquid is produced. Therefore, the present invention has been made based on these findings.

[0010] Specifically, the main point of this invention is as follows. [1] A method for producing a low alpha olefin polymer, comprising a production operation step in which alpha olefin, which is a raw material, is supplied to a reactor and subjected to a low polymerization reaction in the presence of a catalyst and a solvent, and a reaction product containing low alpha olefin polymer, which is a normal product, is supplied as a liquid to a distillation column for product purification; and a termination operation step in which the supply of the catalyst to the reactor is stopped and the solvent is supplied as a liquid between the reactor and the distillation column, Wherein the position of the liquid supply to the distillation column in the termination stage of the operation is at a lower position than the position of the liquid supply to the distillation column in the production stage of the operation. [2] The method for producing a low alpha olefin polymer according to [1] above, wherein in the operation termination step, after the catalyst is supplied to the reactor, the position of the supply liquid to the distillation column is changed to a position lower than the position of the supply liquid to the distillation column in the production operation step. [3] This method for producing a low alpha olefin polymer according to [1] or [2] above, wherein in the feed liquid to the distillation column in the termination step, the concentration of polymers having a molecular weight of 100,000 or more is 100 ppm by weight or more relative to the solvent. [4] The method for producing a low alpha olefin polymer according to any one of [1] to [3] above, wherein the temperature inside the distillation column at the position of supplying the feed liquid to the distillation column in the termination stage of the operation is 110°C or higher. [5] A method for producing a low alpha olefin polymer according to any one of [1] to [4] above, wherein the termination step comprises reducing the partial pressure of the alpha olefin in a portion of the vapor phase of the reactor in at least two stages. [6] The method for producing a low alpha olefin polymer according to any one of [1] to [5] above, wherein the termination step comprises cleaning at least the reactor and a heat exchanger for removing the heat of reaction. [7] The method for producing a low alpha olefin polymer according to any one of [1] to [6] above, wherein the position of supplying the feed liquid to the distillation column is at the end of the operation of the lower section of the distillation column. [8] The method for producing a low alpha olefin polymer according to any one of [1] to [7] above, wherein the distillation column comprises a high alkali separation column. [9] The method for producing a low alpha olefin polymer according to [8] above, wherein the distillation column further comprises an alpha olefin separation column and a product separation column.

[10] The method for producing a low alpha olefin polymer according to [8] or [9] above, wherein the high boiling point components extracted from the lower column of the high boiling point separation column section are supplied to the high boiling point tank in the production operation step and are used as a supply liquid in the operation termination step to the lower column of the high boiling point separation column section.

[11] The method for producing a low alpha olefin polymer according to any one of [1] to

[10] above, wherein the alpha olefin as the raw material is ethylene and the poly-low alpha olefin as the target product is a low alpha olefin having 4 to 10 carbon atoms.

[12] An apparatus for separating alpha olefin polymer and low-polymer from a solution containing alpha olefin poly-complex, a solvent and polymers, wherein the apparatus has two or more source ports of the solution at different vertical positions.

[13] An apparatus according to

[12] , wherein the position of the source port near the upper column, which is above the supply port of the supply ports, is above the lowest tray or filled material and the position of the source port near the lower column, which is the lowest port of the supply ports, is below the end of the lowest tray or filled material.

[14] The apparatus according to

[12] or

[13] above, wherein the low alpha olefin polymer is a polymerization product of ethylene and the alpha olefin has 4 to 10 carbon atoms. Effects of the invention

[0011] According to the present invention, even when the polymer concentration is low in the termination stage of the low-alpha polyolefin polymer production operation (operational operation step), especially during cleaning of the production apparatus, the loading of polymers is suppressed, and furthermore, even when the polymers precipitate, the production of the apparatus is prevented and the operation of the apparatus is continued. Brief description of the maps

[0012] Figure 1 is a schematic view showing the 1-hexene production process of the present invention. Method for implementing the invention

[0013] In the following, this invention will be described in detail: In fact, this invention is not limited to the following embodiments and can be carried out with various modifications within its basic scope.

[0014] 1. Production operation step The method for producing a low alpha olefin polymer according to this invention includes a production operation stage and a termination operation stage. The production operation step is a step in which alpha olefin, which is a raw material, is supplied to a reactor and undergoes a low polymerization reaction in the presence of a catalyst and a solvent, and a reaction product containing a low alpha olefin polymer, which is a target product, is supplied as a feed liquid to a distillation column for product purification. The production operation step of this invention is a continuous step of producing a low alpha olefin polymer, which is the target product, and includes the compositions, apparatus, means, operations, conditions, and the like, which are described hereinafter.

[0015] (Alpha Olefin Raw Material) In this invention, the alpha olefin which is a raw material (sometimes referred to herein as "alpha olefin", "alpha olefin raw material" or "alpha olefin which is a monomer") is a linear or branched alpha olefin having 2 to 30 carbon atoms which may be substituted. Preferably it is a linear or branched alpha olefin having 2 to 6 carbon atoms which may be substituted, and most preferably it is a non-uniform linear alpha olefin having 2 to 6 carbon atoms.

[0016] Specific examples of this alpha olefin include ethylene, propylene, 1-butene, 1-hexene, 1-octene, 3-methyl-1-butene and 4-methyl-1-pentene. Of these, ethylene, propylene and 1-butene are preferred, and ethylene is more preferred. They become poor solvents for the precipitate (mainly polymers formed by the reaction as by-products) which accumulate inside the reactor and / or inside the heat exchanger to remove the heat of reaction.

[0017] Furthermore, also from the viewpoint that the alpha olefin concentration can be easily reduced by low pressure control where the reactor pressure is kept lower than that during operation, alpha olefin, ethylene, propylene or 1-butene are preferred as feedstocks, and ethylene is more preferred. In cases where ethylene is used as a raw material, a pure ethylene product can be used, but a mixture of raw materials containing methane, ethane, acetylene, carbon dioxide, etc. can be used. In cases where a mixture of raw materials is used, the sum of the other components of ethylene is preferably 0.1 mol% or less relative to ethylene. The same is true for other alpha olefins.

[0018] (Low alpha olefin polymer) The low alpha olefin polymer in this invention means an oligomer in which several alpha olefin molecules, which are a monomer, are linked. Specifically, it means an oligomer in which 2 to 10 molecules, preferably 2 to 5 molecules, of alpha olefins, which are a monomer, are linked. Therefore, the low olefin polymer in this invention is sometimes referred to as an alpha olefin ionogram. Similarly, the polymerization reaction of low alpha olefins is sometimes referred to as alpha olefin oligomerization. In cases where ethylene is used as a raw material, an alpha-olefin containing 4 to 10 linear or branched carbon atoms with or without substitution is formed as a target product, and an unsubstituted linear alpha-olefin with 4 to 10 carbon atoms is preferred. Specifically, it can be mentioned that 1-butene is a dimer of ethylene, 1-hexene is a trimer, 1-octene is a tetramer, 1-decane is a pentamer and its fused form, and 1-hexene is more preferred. In cases where the target product is 1-hexene, the content of 1-hexene in the product mixture is preferably 90% by weight or more.

[0019] In cases where propylene is used as a feedstock, a hexane or nanol or a nitrogen or substituted hydrocarbon containing 6 to 9 substituted or unsubstituted carbon atoms is formed as a normal product. In the case where 1-butene is used as a raw material, an octane, which is a dimer of 1-butene, is formed as a target product.

[0020] (Catalyst) The catalyst for use in the present invention is not particularly limited as long as it can oligomerize alpha-olefin and can form oligomers, and those commonly known are used. Usually, a homogeneous catalyst is used. As the homogeneous catalyst, it is preferable that the homogeneous catalyst contains a metallurgical metal compound, an aluminum-containing compound, and a nitrogen-containing compound as catalyst components. Suitable catalyst options of the invention are described below, but the catalyst is not limited thereto.

[0021] (Compound containing a transition metal) The transition metal of the transition metal-containing composition of the present invention means one of the elements belonging to groups 3 to 11 of the periodic table. Of these, transition metals belonging to groups 4 to 6 of the periodic table are preferred. In particular, chromium, titanium, zirconium, vanadium, hafnium and tantalum are more preferred. These transition metals may be used alone or two or more of them may be used. Chromium or titanium is more preferred, and chromium is more preferred than the others.

[0022] As a transition metal-containing compound, a compound represented by formula (1) can be mentioned: MeZn(1) wherein Me represents a transition metal element, Z represents an organic group or an inorganic group or a negative atom, and n represents an integer of 1 to 6, and preferably 2 or more than 2. If n is 2 or more than 2, Z may be the same or different. The organic group may be a hydrocarbon group having 1 to 30 carbon atoms and preferably a substituent, and specific examples include a carbonyl group, an alkoxy group, a carboxyl group, a -diketonate group, a -ketocarboxyl group, a -ketoester group, an amide group, etc. Examples of the inorganic group include a salt-forming metal group such as a nitrous acid group, a sulfuric acid group, etc. Examples of the negative atom include an oxygen atom, a halogen atom. In fact, compounds containing transition metals containing halogens are not included in the halogen-containing compounds to be mentioned subsequently.

[0023] Specific examples of the transition metal-containing compound in which the transition metal is chromium (hereinafter referred to as the chromium-containing compound) include 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 (wherein Ph represents a phenyl group), chromium(II) acetate, chromium(III) acetate, chromium(III)-2-ethylhexanoate, chromium(III) benzoate, chromium(III) naphthenate, chromium(III) heptanoate, Cr(CH3COCHCOOCH3)3, divalent chromium chloride, chromium chloride, divalent chromium bromide, chromium bromide, divalent chromium iodide, chromium iodide, divalent chromium fluoride, chromic fluoride, etc.

[0024] Specific examples of the transition metal-containing compound in which the transition metal is titanium (hereinafter referred to as the titanium-containing compound) include TiCl4, TiBr4, TiI4, TiBrCl3, TiBr2Cl2, , Ti(OC2H5)4, Ti(OC2H5)2Cl2, Ti(On-C3H7)4, Ti(On-C3H7)2Cl2, Ti(O-iso-C3H7)4, , Ti(O-iso-C3H7)2Cl2, Ti(On-C4H9)4, Ti(On-C4H9)2Cl2, Ti(O-iso-C4H9)4, Ti(O-iso-C4H9)2Cl2, , Ti(O-tert-C4H9)4, Ti(O-tert-C4H9)2Cl2, TiCl4(thf)2 (In this chemical formula, thf represents tetrahydrofuran) is), Ti((CH3)2N)4, Ti((C2H5)2N)4, Ti((n-C3H7)2N)4, Ti((iso-C3H7)2N)4,, Ti((n-C4H9)2N)4, Ti((tert-C4H9)2N)4, Ti(OSO3CH3)4, Ti(OSO3C2H5)4, Ti(OSO3C3H7)4, Ti(OSO3C4H9)4, TiCp2Cl2, TiCp2ClBr, Ti(OCOC2H5)4, Ti(OCOC2H5)2Cl2, Ti(OCOC2H5)2Cl2, Ti(OCOC3H7)4, Ti(OCOC3H7)2Cl2, Ti(OCOC3H7)2Cl2, Ti(OCOC4H9)4 and Ti(OCOC4H9)2Cl2.

[0025] Specific examples of the transition metal-containing compound in which the transition metal is zirconium (hereinafter referred to as the zirconium-containing compound) include ZrCl4, ZrBr4, ZrI4, ZrBrCl3, ZrBr2Cl2, Zr(OC2H5)4, Zr(OC2H5)2Cl2, Zr(On-C3H7)4, Zr(On-C3H7)2Cl2, Zr(O-iso-C3H7)4, Zr(O-iso-C3H7)2Cl2, Zr(On-C4H9)4, Zr(On-C4H9)2Cl2, Zr(O-iso-C4H9)4, Zr(O-iso-C4H9)2Cl2, Zr(O-tert-C4H9)4, Zr(O-tert-C4H9)2Cl2, Zr((CH3)2N)4, Zr((C2H5)2N)4, Zr((n-C3H7)2N)4, Zr((iso-C3H7)2N)4, Zr((n-C4H9)2N)4, Zr((tert-C4H9)2N)4, Zr(OSO3CH3)4, Zr(OSO3C2H5)4, Zr(OSO3C3H7)4, Zr(OSO3C4H9)4, ZrCp2Cl2, ZrCp2ClBr, Zr(OCOC2H5)4, Zr(OCOC2H5)2Cl2, Zr(OCOC3H7)4, Zr(OCOC3H7)2Cl2, Zr(OCOC3H7)2Cl2, Zr(OCOC4H9)4, Zr(OCOC4H9)2Cl2, ZrCl2(HCOCFCOF)2, ZrCl2(CH3COCFCOCH3)2.

[0026] Specific examples of a transition metal-containing compound wherein the transition metal is hafnium (hereinafter referred to as a hafnium-containing compound) include: dimethylsilylenebis{1-(2-methyl-4-isopropyl-4H-azulenyl)}hafnium dichloride, dimethylsilylenebis{1-(2-methyl-4-phenyl-4H-azulenyl)}hafnium dichloride, dimethylsilylenebis[1-{2-methyl-4-(4-chlorophenyl)-4H-azulenyl}]hafnium dichloride, dimethylsilylenebis[1-{2-methyl-4-(4-fluorophenyl)-4H-azulenyl}]hafnium dichloride, dimethylsilylenebis[1-{2-methyl-4-(3-chlorophenyl)-4H-azulenyl}]hafnium dichloride, dimethylsilylenebis[1-{2-methyl-4-(2,6-dimethylphenyl)-4H-azulenyl}]hafnium dichloride, dimethylsilylenebis{1-(2-methyl-4,6-diisopropyl-4H-azulenyl)}hafnium dichloride, diphenylsilylenebis{1-(2-methyl-4-phenyl-4H-azulenyl)}hafnium dichloride, methylphenylsilylenebis{1-(2-methyl-4-phenyl-4H-azulenyl)}hafnium dichloride, methylphenylsilylenebis[1-{2-methyl-4-(1-naphthyl)-4H-azulenyl}]hafnium dichloride, dimethylsilylenebis{1-(2-ethyl-4-phenyl-4H-azulenyl)}hafnium dichloride, dimethylsilylenebis[1-{2-ethyl-4-(1-anthracenyl)-4H-azulenyl}]hafnium dichloride,dimethylsilylenebis[1-{2-ethyl-4-(2-anthracenyl)-4H-azulenyl}]hafnium dichloride, dimethylsilylenebis[1-{2-ethyl-4-(9-phenanthryl)-4H-azulenyl}]hafnium dichloride, dimethylmethylenebis[1-{2-methyl-4-(4-biphenylyl)-4H-azulenyl}]hafnium dichloride, dimethylgermylenebis[1-{2-methyl-4-(4-biphenylyl)-4H-azulenyl}]hafnium dichloride, dimethylsilylenebis[1-{2-ethyl-4-(3,5-dimethyl-4-trimethylsilylphenyl)-4H-azulenyl}]hafnium dichloride, dimethylsilylene[1-{2-methyl-4-(4-biphenylyl)-4H-azulenyl}][1-{2-methyl-4-(4-biphenylyl)indenyl}]hafnium dichloride, dimethylsilylene{1-(2-ethyl-4-phenyl-4H-azulenyl)}{1-(2-methyl-4,5-benzoindenyl)}hafnium dichloride, dimethylsilylenebis{1-(2-methyl-4-phenylindenyl)}hafnium dichloride, dimethylsilylenebis{1-(2-methyl-4,5-benzoindenyl)}hafnium dichloride, و dimethylsilylenebis[1-{2-methyl-4-(1-naphthyl)indenyl}]hafnium dichloride هستند. Among these transition metal-containing compounds, chromium-containing compounds are preferred; and among chromium-containing compounds, chromium(III)-2-ethylhexanoate is particularly preferred.

[0027] (Aluminum-containing compounds) As the aluminum-containing compound of the present invention, for example, a trialkylaluminum compound, an alkoxyalkylaluminum compound, or a hydrogenated alkylaluminum compound can be mentioned. Trialkylaluminum compounds have alkyl groups that have 1 to 8 carbon atoms, and the alkyl groups may be the same or different from each other. Examples include trimethylaluminum, triethylaluminum, and triisobutylaluminum.

[0028] The alkyne alkyl aluminum compound has alkyl groups of 1 to 8 carbon atoms and an alkyne group of 1 to 8 carbon atoms, and specific examples thereof include aluminum ethoxides and the like. The hydrogenated alkyl aluminum compound has alkyl groups having 1 to 8 carbon and hydrogen atoms, and specific examples thereof include aluminum hydride and the like. Of these, trialkylaluminum compounds are preferred, and triethylaluminum is particularly preferred. These compounds may be used as a single compound or may be used as a combination of a number of compounds.

[0029] (nitrogen-containing compounds) As a nitrogen-containing compound, it can be referred to as an amino compound, an amide compound, or an amide compound. As an amino compound, a pyrrole compound can be mentioned, for example. Specific examples thereof include pyrrole, 2,4-dimethylpyrrole, 2,5-dimethylpyrrole, 2,5-diethylpyrrole, 2,4-diethylpyrrole, 2,5-di-n-propylpyrrole, 2,5-di-n-butylpyrrole, 2,5-di-n-pentylpyrrole, 2,5-di-n-hexylpyrrole, 2,5-dibenzylpyrrole, 2,5-diisopropylpyrrole, 2-methyl-5-ethylpyrrole, 2,5-dimethyl-3-ethylpyrrole, 3,4-dimethylpyrrole, 3,4-dichloropyrrole, 2,3,4,5-tetrachloropyrrole, 2-acetylpyrrole, indole, 2-methylindole and dipyrrole in which two pyrrole rings are linked through a substituent and derivatives thereof. Derivatives include, for example, metal derivatives of pyrrolide, and specific examples thereof include, for example, aluminum pyrrolides such as diethylaluminium pyrrolide, ethylaluminium dipyrrolide, aluminum tripyrrolide, diethylaluminium (2,5-dimethylpyrrolide), ethylaluminium bis(2,5-dimethylpyrrolide), aluminum tris (2,5-dimethylpyrrolide), diethylaluminium (2,5-diethylpyrrolide), ethylaluminium bis(2,5-diethylpyrrolide), aluminium tris(2,5-diethylpyrrolide); sodium pyrrolides such as sodium pyrrolide, sodium (2,5-dimethylpyrrolide); lithium pyrrolides such as lithium pyrrolide, lithium (2,5-dimethylpyrrolide); potassium pyrrolides such as potassium pyrrolide, potassium (2,5-dimethylpyrrolide). Aluminium pyrrolides are not included in the above-mentioned aluminium-containing compounds. Also, halogen-containing pyrroles are not included in the halogen-containing compounds mentioned below.

[0030] Examples of imide compounds include acetamide, N-methylhexanamide, succinamide, maleamide, N-methylbenzamide, imidazole-2-carboxamide, di-2-thioylamine, -lactam, -lactam, and ε-caprolactam or their salts with a metal belonging to Group 1, 2, or 13 of the Periodic Table. Examples of imides include 1,2-cyclohexanedicarboxyimide, succinimide, phthalimide, maleimide, 2,4,6-piperidinetrione and perhydroazecine-2,10-dione, or their salts with a metal belonging to groups 1, 2 or 13 of the periodic table. Examples of sulfonamides and sulfonimides include benzenesulfonamide, N-methylmethanesulfonamide and N-methyltrifluoromethylsulfonamide, or their salts with a metal belonging to groups 1, 2 or 13 of the periodic table. These compounds may be used as a single compound or as a number of compounds.

[0031] In the present invention, of these, an amine is preferred. In particular, a pyrrole compound is preferred, and 2,5-dimethylpyrrole or diethylaluminum (2,5-dimethylpyrrolide) is particularly preferred. Furthermore, in the case of using a homogeneous catalyst in the invention, in addition to the above three harmful fluoride compounds, aluminum compounds and nitrogen-containing compounds, it is preferable to also contain halogen-containing compounds.

[0032] As the halogen-containing compounds, there may be a halogenated alkali aluminum compound, a compound containing a benzyl chloride skeleton, a linear halogenated hydrocarbon having one or more carbon atoms and two or more halogen atoms, and a halogenated hydrocarbon having three or more carbon atoms and two or more halogen atoms. The halogenated alkali aluminum compound is not contained in the aluminum compound. Examples include diethylaluminum chloride, ethylaluminum sesquichloride, benzyl chloride, (1-chloroethyl)benzene, 2-methylbenzyl chloride, 3-methylbenzyl chloride, 4-methylbenzyl chloride, 4-ethylbenzyl chloride, 4-isopropylbenzyl chloride, 4-tert-butylbenzyl chloride, 4-vinylbenzyl chloride,  -ethyl-4-methylbenzyl chloride,  , '-dichloro-o-xylene,  , '-dichloro-m-xylene,  , '-dichloro-p-xylene, 2,4-dimethylbenzyl chloride, 2,5-dimethylbenzyl chloride, 2,6-dimethylbenzyl chloride, 3,4-dimethylbenzyl chloride, 2,3,5,6-tetramethylbenzyl chloride, 1-(chloromethyl)naphthalene, 1-(chloromethyl)-2-methylnaphthalene, 1,4-bis-chloromethyl-2,3-dimethylnaphthalene, 1,8-bis-chloromethyl-2,3,4,5,6,7-hexamethylnaphthalene, 9-(chloromethyl)anthracene, 9,10-bis(chloromethyl)anthracene, 7-(chloromethyl)benzanthracene, 7-chloromethyl-12-methylbenzanthracene, carbon tetrachloride, 1,1,1-trichloroethane, 1,1,2,2-tetrachloroethane, pentachloroethane, hexachloroethane, 1,2,3-trichlorocyclopropane, 1,2,3,4,5,6-hexachlorocyclohexane, and 1,4-bis(trichloromethyl)-2,3,5,6-tetrachlorobenzene They are.

[0033] (Contact method) In this invention, in cases where the catalyst for low polymerization (oligomerization) is used, a three-component catalyst containing the aforementioned transition metal compound, aluminum compound and nitrogen compound or a four-component catalyst containing halogen-containing compound, it is preferred to contact the raw alpha olefin material with the catalyst in a state where the crystallized metal compound is preliminarily combined with an aluminum-containing compound or a previous contact time is short; By adopting such a contact state, the low polymerization (oligomerization) reaction of the raw alpha olefin can be selected and the raw alpha olefin oligomer can be obtained in high yield. In this invention, "contacting is carried out under conditions in which the transition metal-containing compound and the aluminum-containing catalyst compound are not previously in contact with each other, or the time for the two is short" means that the above-mentioned conditions are maintained not only at the beginning of the reaction but also during the period in which the alpha-olefin feedstock and the catalyst components are also fed to the reactor.

[0034] The reason why the activity of the low alpha olefin polymerization reaction is reduced in cases where the catalyst is used in a state where the transition metal compound-containing compound is previously contacted with the aluminum compound is not yet clear, but it is assumed to be as follows. For example, in cases where the crystalline metal compound is obtained with an alkali aluminum compound, it is considered that the ligand exchange reaction between the ligand correlation to the corresponding metal compound and the alkyl group in the alkali aluminum compound and thus the catalyst becomes unstable. For this reason, the decomposition reaction and the reaction of the alkali metal containing metal compound and mainly proceed, resulting in metallization which is unsuitable for the low alpha olefin polymerization reaction, and the activity of the low alpha olefin polymerization reaction is reduced.

[0035] Therefore, in cases where the catalyst is composed of the above four components, namely the metal comprising the compounds (a), the nitrogen-containing compounds (b), the aluminum-containing compounds (c) and the halogen-containing compounds (d), the mode for contacting the components, usually in the presence of an alpha-olefin, is carried out, for example, (1) a method for introducing a solution containing the catalyst components (b), (c) and (d) and a solution containing the catalyst generator (a) into the reactor, (2) a method for introducing the solution (a), (b) and (d) of the catalyst and the solution containing the catalyst generator (c) into the reactor, (3) a method for introducing the solution containing the catalyst components (a) and (d) and the solution containing the catalyst components (b) and (c) into the reactor, (4) a method for introducing a solution containing the catalyst components (c) and (d) and a solution containing the catalyst components (a) and (b) into the reactor (5) A method for introducing a solution containing catalysts (a) and (b) and a solution containing catalyst components (c) and (d) into a reactor. (6) A method for introducing a solution containing catalyst components (b) and (c) and a solution containing catalyst components (a) and (d) into a reactor. (7) A method for introducing a solution containing catalyst generator (c) and a solution containing(8) a method of introducing a solution containing the catalyst precursor (a) and a solution containing the catalyst components (b) to (d) into the reactor, and (9) a method of simultaneously introducing each of the catalyst components (a) to (d) into the reactor, each of the above solutions typically using the solvent used for the reaction.

[0036] (Halal) The solvent for the present invention is not specifically limited, but is preferably a saturated hydrocarbon. For example, the solvent is a linear saturated hydrocarbon having 1 to 20 carbon atoms or alicyclic saturated hydrocarbon having 1 to 20 carbon atoms such as butane, pentane, 3-methylpentane, n-hexane, n-heptane, 2-methylhexane, octane, cyclohexane, methylcyclohexane, 2,2,4-trimethylpentane, decalin. In addition, aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, mesitylene, tetralin or an alpha oligomer such as 1-hexene, 1-octene or 1-decene are used as a solvent. They can be used alone or as a mixed solvent.

[0037] Of these solvents, it is preferable to use linear saturated hydrocarbons or alicyclic mixed hydrocarbons having 4 to 10 carbon atoms from the viewpoint of preventing the formation or precipitation of by-product polymers such as polyethylene and the like, and also from the viewpoint of being able to achieve high catalytic activity. Specifically, n-heptane or cyclohexane is preferred; and n-heptane is most preferred.

[0038] (Conditions for low polymerization reaction (oligomerization)) In this invention, in cases where a homogeneous catalyst is used as a catalyst, a three-component catalyst comprising the above-mentioned alternating compound-containing compounds, aluminum compounds and nitrogen-containing compounds or a four-component catalyst comprising a halogen compound containing, according to the ratio of each constituent molecule, usually relative to 1 mol of the metal-containing compound, the aluminum compound is 1 mol or more, preferably 10 mol or more and 200 mol or less, preferably 150 mol or less, and the nitrogen compound is 1 mol or more and 50 mol or less, preferably 30 mol or less. The halogen-containing compound is 1 mol or more, preferably 3 mol or more and 60 mol or less, preferably 40 mol or less.

[0039] In this invention, the amount of the catalyst used is not particularly limited, but in the case of a three-component catalyst containing the aforementioned transition metal-containing compounds, an aluminum compound and nitrogen-containing compounds or a four-component catalyst containing halogen-containing compounds, the amount is usually 1.010-8 mmol to 0.05 mol, preferably 5.010-8 mol to 0.02 mol, and more preferably 1.010-7 mol to 0.005 mol in terms of 1 atom of the crystallized transition metal, per liter of solvent.

[0040] In this invention, the low polymerization reaction temperature for alpha-olefin is not particularly limited. In general, the temperature may be between 0 and 250°C, preferably from 50 to 200°C, and even more preferably from 80 to 170°C. In addition, the reaction pressure is usually from normal pressure to 0 to 25 MPaG (gauge pressure, this will be true hereinafter in this text), preferably from 0.5 to 15 MPaG, and more preferably from 0.1 to 10 MPaG. The partial pressure of the alpha-olefin feedstock during the reaction period is not particularly limited. In general, the pressure may be from normal pressure to 23 MPaG, preferably from 0.4 to 14 MPaG, and more preferably from 0.9 to 3.7 MPaG. Furthermore, the residence time in the reactor is not particularly limited. Generally, the time is from 1 minute to 10 hours, preferably from 5 minutes to 3 hours, and more preferably from 10 minutes to 1 hour. The type of reaction in this invention is not particularly limited and can be closed, semi-closed, or continuous.

[0041] (Method for producing low alpha olefin polymer) The method for producing a low-alpha-olefin polymer has been described with reference to the example of low-polymerization of 1-hexene in which the ethylene trimer is a low-alpha-olefin polymer using ethylene as the alpha-olefin. However, the alpha-olefin is not limited to ethylene and the low-alpha-olefin polymer is not limited to 1-hexene, and the following production method is used for cases in which the above-mentioned low-alpha-olefin polymer is produced using the alpha-olefin described above in this invention.

[0042] Figure 1 is a flow chart of a 1-hexene production process using ethylene as a feedstock. Figure 1 shows a fully mixed and stirred reactor 10 in which ethylene undergoes low polymerization in the presence of a catalyst, a stripping vessel 20 that separates unreacted ethylene gas from a reaction liquid extracted from the reactor 10, an ethylene separation column 30 that separates ethylene in the reaction liquid extracted from the stripping vessel 20, a high-boiling material separation column that separates a high-boiling material in the reaction liquid extracted from the ethylene separation column 30, and a 1-hexene separation column 50 that distills the reaction liquid extracted from the top of the high-boiling material separation column to 1-hexene, respectively. In addition, a compressor 17 circulates the unreacted ethylene separated in the discharge tank 20 and a condenser 16 to the reactor 10 through a pipe 21.

[0043] The reactor 10 in Fig. 1 is of a conventionally known type equipped with a stirring machine 10a, a reflector, a jacket, and the like. In addition, as the reactor, a ring reactor or the like can be used. The stirring machine 10a is of a paddle type, and in addition, a stirring blade of the type such as Pfaudler, impeller, turbine or the like can be used in combination with a reflector such as a flat plate, a cylinder or a coiled hook. Ethylene is continuously supplied to the reactor 10 from an ethylene supply pipe 12a through a compressor 17 and a first-stage pipe 12. Here, if the compressor 17 is, for example, a two-stage compression system, the first stage is connected to the transfer pipes 31 and the second stage is connected to the transfer pipes 21 and 31 and the ethylene supply pipe 12a, so it is possible to reduce power consumption.

[0044] In addition, a solvent, n-heptane, used in the ethylene bottom polymerization reaction, is supplied to the reactor 10 from the second pipe 13. Common metal compounds and nitrogen-containing compounds are prepared in advance in catalyst tanks (not shown in the figure) and are supplied from the second pipe 13 supplied by the reactor 10 via a catalyst supply pipe 13a. Aluminum-containing compounds are usually supplied from a pipe provided by the third pipe 14, but if the time it takes to transfer to the reactor is within a few minutes after contact with the metallurgical compound of the alternating metal, it is supplied to the reactor 10 through the second pipe 13.

[0045] The halogen-containing compounds are usually supplied from a fourth supply line but may also be supplied to the reactor 10 via a second delivery line 13. In order to deliver a uniform mixture of each catalyst generator to the reactor 10 and to reduce the stirring power of the reactor 10, a static mixer or the like can be placed between the second supply pipes 13 and the reactor 10.

[0046] The ethylene trimerization reaction is preferably carried out so that the molar ratio of 1-hexene to ethylene in the reaction liquids ((molar concentration of 1-hexene in the reaction liquid) / (molar concentration of ethylene in the reaction liquid) is from 0.05 to 1.5, and particularly from 10.10 to 1.0. Accordingly, in the case of a continuous reaction, it is preferable to control the catalyst concentration, reaction pressure and other conditions so that the molar ratio of 1-hexene to ethylene in the reaction liquid is in a high range. In the case of a batch reaction, the ethylene trimerization reaction is preferably stopped when the molar ratio is in a higher range. As a result, the by-production of components with a higher boiling point than 1-hexene is suppressed, and hence the selectivity of 1-hexene is further increased.

[0047] The reaction liquid is continuously extracted from the bottom of the reactor 10 through a pipe 11 and is transferred to the gas discharge tank 20 by the inactivator action supplied from an inactivator supply pipe 11a. The reaction liquid from which the unreacted ethylene is denatured is extracted from the bottom of the gas discharge tank 20. The operating conditions of the gas discharge tank 20 are not particularly limited, but the temperature is usually from 0°C to 240°C, and preferably from 50°C to 190°C, and the pressure is not particularly limited, but is usually from atmospheric pressure to 14 MPa, and preferably from atmospheric pressure to 9 MPa.

[0048] The reaction liquid from which the reacted ethylene gas is discharged in the gas discharge tank 20 is extracted from the bottom of the discharge tank 20 and is conveyed to the ethylene separation column 30 by a pipe 22. In the ethylene separation column 30, the distilled ethylene is distilled from the top of the column and conveyed into the reactor 10 and is supplied through the circulating pipe 31 and the first pipe 12. The reaction liquid from which the ethylene is removed is extracted from the bottom of the column. Meanwhile, as a sealing pipe to the ethylene separation column, in addition to the pipes 22, the pipe is capable of being supplied to a position where the internal temperature of the distillation column is higher than that of the pipes 22.

[0049] The operating conditions of the ethylene separation column 30 are that the column top pressure is not particularly limited, but is usually from normal pressure to 3 MPa and preferably from normal pressure to 2 MPa, the reflux ratio (R / D) is generally from 0 to 500, and preferably from 0.1 to 100, and the supply plate temperature is usually from 80°C to 170°C. Then the reaction product (also called reaction liquid) containing low alpha olefin polymer which is the target product and after ethylene is distilled in the ethylene separation column, it is separated from the ethylene separation column 30 and supplied to the boiling material separation column 40 with pipes 32 and purified. As the distillation column of the invention, the high boiling material separation column 40 is well illustrated.

[0050] In the high-boiling material separation column 40, the low-boiling components (1-hexene as the target product, n-heptane as the solvent) are removed from the column by distillation through a pipe 41. In addition, the high-boiling components (high-boiling material, inactive catalyst) are obtained from the bottom of the pipe by a pipe 42. The high-boiling components extracted from the pipe 42 are transferred to a boiling liquid tank (not shown in the figure). In the high-boiling components, an alcohol or amine having 6 or more carbon atoms is preferably present in the free state because it can deactivate a minute amount of catalyst components such as alkali aluminum contained in the polymer.

[0051] The operating conditions of the high-boiling material separation column are that the column top pressure is usually not particularly limited, but is usually from normal pressure to 1 MPa and preferably from normal pressure to 0.5 MPa, the reflux ratio (R / D) is not particularly limited, but is usually from 0 to 100 and preferably from 0.1 to 20, and the feed plate temperature (tube feed plate 32) is usually from 60°C to 105°C. Distillation from the top column of the high-boiling material separation column is applied to the 1-hexene separation column 50 by pipe 41. In the 1-hexene separation column 50, 1-hexene is supplied as a distillate from a pipe 51 in the upper mixing column. In addition, n-heptane, which is a solvent, is extracted from the column separated from the 1-hexene separation column 50 through the solvent continuous pipe 52 and, passing through the solvent 60, is further supplied as a reaction solvent to the reactor 10 through the second supply pipe 13.

[0052] The operating conditions of the 1-hexene separation column 50 are not particularly limited, but the column top pressure is usually from atmospheric pressure to 1 MPa, and preferably from atmospheric pressure to 0.5 MPa, and the reflux ratio (R / D) is usually from 0 to 100, and preferably from 0.1 to 20.

[0053] (substance with high boiling point) A high-boiling material is a material with a higher boiling point than the target product, and a polymer lower than the alpha-olefin, especially one with a molecular weight of 10,000, is called a polymer. For example, in cases where the alpha-olefin is ethylene and the target product is 1-hexene, a low-olefin polymer with more than 6 carbon atoms is the boiling material, in which case the decanes become the main components.

[0054] 2. End of operation step. The termination step of the inventive operation includes that the catalyst supply to the reactor is stopped and the solvent is supplied and supplied between the reactor and the distillation column as a supply liquid, and the supply liquid to the distillation column is supplied from a position lower than the position of the supply liquid supply to the distillation column in the production operation stage. Here, the supply of catalyst to the reactor may be the supply of catalyst to the reactor after the catalyst has been formed outside the reactor or may be the formation of a catalyst active material in the reactor. Thus, the termination of the supply of catalyst to the reactor may be the termination of the supply of catalyst or the termination of the supply of the described compounds that form the catalyst. The supply and circulation of solvent between the reactor and the distillation column means the supply and circulation of solvent after the separation of the reaction product in the distillation column.

[0055] In addition, the solvent circulation between the reactor and the distillation column is the same as the solvent circulation between the ethylene separation column, the high-boiling material separation column or the target product (1-hexene) separation column and the reactor in the same production operation step as described above. Of these separation columns, the high-boiling material separation column is preferred, but the solvent can be circulated to other separation columns in addition to the alkali separation column, and more preferably, the α-olefin separation column and the product separation column.

[0056] In addition, the position lower than the position of the supply liquid supply to the distillation column in the production operation stage is a position near the bottom of the column from the position of the supply liquid supply to the distillation column in the production operation stage. That is, it is sufficient that the position of the supply liquid supply to the distillation column in the completion operation stage is lower than the position of the supply liquid supply in the production operation stage by one or more theoretical plates (about 0.5 m or more), more preferably two or more plates (about 1.0 m or more). This distillation column is preferably a device that separates low alpha olefin polymer and polymers from a solution containing low alpha olefin polymer, solvent and polymer, and is preferably a high boiling point separation column in a production operation. The distillation column is a device that has two or more source ports from the solution at different vertical positions, for example, supply ports near the top of the column and supply ports (near the bottom of the column). It is further preferred that the position of the supply port near the top column, which is the highest feed port, is higher than the end of the lowest tray or filled material and the position of the supply port near the bottom of the column, which is the lowest inlet port, is lower than the end of the lowest tray or filled material. Additionally, the inventive termination operational step includes creating a partial pressure of alpha olefin in a portion of the vapor phase of the reactor for reduction in at least two stages and cleaning the reactor and / or heat exchanger to eliminate the reaction heat.

[0057] As a method of terminating the supply of catalyst to the reactor, for example, in Figure 1, the supply of the transition metal-containing compound and the nitrogen-containing compound from the catalyst supply pipes 13, the supply of the aluminum-forming material from the third supply pipe pipes 14, and the supply of the halogen-containing compound from the fourth supply pipe pipe 15 are terminated. When the supply of the catalyst to the reactor is stopped, the active species of the catalyst are reduced and the reaction is gradually terminated. In the invention, even after the catalyst supply to the reactor is terminated, the solvent circulation continues in the production operation stage. The amount of solvent circulation may be increased or decreased.

[0058] At the same time as the reaction is terminated, the supply of alpha-olefin feedstock also decreases. This means that the partial pressure of alpha-olefin in the vapor phase of the reactor has decreased. When the solvent circulation continues in this state, the polymer concentration in the solvent increases. The reason is not clear, but the inventors of this invention believe that: Solid matter is produced as a by-product by the low polymerization (oligomerization) reaction of alpha olefin. The solid matter is one of them containing polymers and catalyst residue which is transferred to the reactor and the matter precipitates when it is not dissolved in the solvent and sticks to the inner walls of the production equipment such as the reactor, heat exchanger and distillation column and also the catalyst supplied to the reactor or its residue remains in a physical boundary of the liquid present at the solid-liquid phase boundary on the inner wall of the reactor and as a result polymers are formed and grown on the inner wall of the reactor. In addition, when the solid matter reaches the inner walls of the production equipment or the precipitated solid matter precipitates, the production equipment may sometimes be blocked.

[0059] When the alpha olefin is kept in the solvent, the alpha olefin acts as a poor solvent for the solid, so that the solid is prevented from dissolving in the solvent. In addition, when the polymerization reaction of the low alpha olefin is completed, the concentration of the alpha olefin oligomer, which is an unsuitable solvent for the solid (polymer) in the solvent, is reduced, so that the solid is likely to dissolve in the solvent. When the polymer concentration in the solvent increases, the trays, guts, or packings of the distillation column may sometimes become clogged by the polymers that are trapped due to the temperature drop after passing through the valve that provides the liquid flow for supply to the distillation column (especially the boiling point separation column).

[0060] As the concentration of the polymer solvent supplied to the distillation column, it is desirable that the concentration of polymers having a molecular weight of 100,000 or more is 1500 ppm or less, more preferably 1000 ppm by weight or less. When the polymer concentration is too high, the polymers precipitate due to the temperature drop after passing through a valve that controls the flow rate of the liquid delivered to the distillation column, and hence the risk of pipe blockage when the polymer concentration in the solvent increases, by changing the supply position of the supply liquid to the distillation column to a position lower than the supply position in the production operation stage, and the solid matter estimation can be suppressed or even when solid matter precipitates, the apparatus can be prevented from clogging.

[0061] The mode of changing the position of the liquid feed source to the distillation column to the lower position is not particularly limited, and examples thereof include a mode of changing the line from the upper line to the lower line, and a mode of decreasing the supply amount from the upper line and increasing the supply amount from the lower line. In FIG. 1, for example, a sealing pipe to the high-boiling material separation column 40, in addition to the pipes 32, there is a pipe 33 for supplying a distillation column with a temperature higher than the pipes 32. Since the distillation column is usually a boiler at the bottom of the column, the pipe 33 is lower than the pipe 32. When the pipe 33 is used, in cases where the polymer concentration in the reaction liquid extracted from the ethylene separation column 30 increases, it is performed to prevent the high-boiling material separation column 40 from clogging.

[0062] The timing of changing the position of the liquid feed source to the distillation column to the lower position is not particularly limited, since the change is made at the end of the operation. For example, the change may be made simultaneously with the end of the catalyst supply to the reactor, after the end of the catalyst supply, or it may even be made before the end of the catalyst supply because the timing in the end of the operation and thus the catalyst supply may end soon. Furthermore, the inventors have found that the above problem such as the risk of pipe blockage due to the increase of precipitated polymers in a large amount is likely to occur in cases where the concentration of polymers having a molecular weight of 100,000 or more in the supply liquid to the distillation column is 100 ppm by weight or more. In other words, when a solution containing polymers having a molecular weight of 100,000 or more in an amount of 100 ppm by weight or more is supplied to the distillation column, the solvent is precipitated by a pressure drop in the supply portion of the distillation column after passing through a valve that controls the flow of the liquid, and at the time of temperature drop, the polymer precipitates under fluidization and agitation conditions, and hence the large polymers precipitate rapidly so that the distillation column may in some cases cause flooding. It is considered that this is because the liquid supplied from the discharge of the feed plate with the deposition of polymer precipitates uniformly on the lower portion of the plate.The reason for the loading of large polymers is not clear, but it is considered that if polymers with a large molecular weight are present at a certain concentration or more under fluidization or co-precipitation conditions, the polymers will form filaments or large enough to form complex entanglements, and individual polymer molecules will be formed during precipitation. In the case of polymers with a molecular weight of less than 100,000, since the molecular chain is short, it is considered that the polymer molecular chains are less likely to cross-link. Therefore, in the present invention, it is preferable to change the supply position of the feed liquid to the distillation column to a lower position before the concentration of polymers having a molecular weight of 100,000 or more in the feed liquid to the distillation column becomes 100 ppm by weight, in other words, the effect of the invention is to change the supply position of the feed liquid to the distillation column in the operation termination stage to a position that is lower than the supply position of the feed liquid to the distillation column in the production operation stage, and in cases where the feed liquid is used in which the concentration of polymers having a molecular weight of 100,000 or more is 100 ppm by weight or more, the efficiency is lower. In addition, this phenomenon may occur in common cases not only in cases where the alpha olefin raw material is ethylene but also in the alpha olefin raw materials defined in the invention.

[0063] The internal temperature of the column at the position of supplying the feed liquid to the distillation column is preferably 110°C or higher, which is the temperature at which the polymer swelling, adhesion and hardness reduction and solubility of the polymer increase, and more preferably 130°C or higher, which is the melting point of the polymer. The upper limit of the liquid temperature inside the column at the position of feeding the liquid to the distillation column is not particularly limited, but can usually correspond to the upper limit of the reaction temperature.

[0064] As the position of supplying the supply liquid to the distillation column in the termination stage of the operation, it is preferably a lower part of the column without trays or packed materials. In other words, the distillation column is roughly classified into a packed column and a tray column according to the internal structure. In the packed column, the packed materials are incorporated and distillation is achieved by contacting the liquid gas on the surface of the packed materials. In the tray column, a number of plates with open holes, called trays, are installed, and distillation is achieved by contacting the liquid gas in the trays. The bottom of a distillation column means a position below the packing or tray which is at the end of the least number of packings or trays installed in this distillation column.

[0065] As a method of releasing the partial pressure of the alpha olefin in the vapor phase part of the reactor, the pressure is reduced in two stages, more preferably in three stages. Thus, it is preferable to release the partial pressure of the alpha olefin in a small amount in the next stage. In this way, the effect of preventing the polymer from clogging in the low-temperature piping parts is achieved. The pressure of the alpha olefin in the operation termination stage is from 0% to 99%, preferably from 1% to 75%, of the pressure of the alpha olefin raw material in the production operation stage (at the time of reaction). In cases where the alpha olefin raw material is ethylene and the low alpha olefin polymer is 1-hexane, the pressure is more than 10 to 45% of the pressure of the alpha olefin raw material at the time of reaction.

[0066] As the pressure drop rate of the alpha olefin fraction, for example, the amount of ethylene supplied from the initial supply pipes in Figure 1 is reduced, and the reactor pressure is reduced from 7 MPa to 3 MPa. The rate of reduction is usually 10 minutes or more, preferably 30 minutes or more, and more preferably 60 minutes or more per 1 MPa. In the termination stage of the invention, the position of the feed liquid supply to the distillation column is lower than that of the production stage, but in the distillation column, the target product is distilled from the column and the high-boiling material is discharged from the bottom. In the production stage, the base product is preferably stored in the high-boiling material tank, and in the termination stage, the base product is preferably located between the distillation column and the high-boiling material tank. This is because since the polymer concentration of the liquid supplied to the distillation column is supplied in the termination stage, the above operation leads to dilution with the bottom product having a lower polymer concentration than that in the feed liquid and from the high-boiling material tank with a volume much larger than the lower part of the distillation column, and thus prevents blockage.

[0067] In Figure 1, the high-boiling components are removed from the lower column of the high-boiling separation column through pipe 42 and transferred to the high-boiling tank (not shown in the figure). As for the high-boiling components in the large-boiling tank, in order to prevent clogging of the pipe and apparatus when the polymer concentration in the lower section of the high-boiling separation column increases, it is preferable to have a means for supplying and circulating a certain amount of components to the lower section of the high-boiling separation column. In addition, there is an effect that the reduction of the heat transfer coefficient of the distillation column boiler is prevented by reducing the highly viscous polymer liquid to a low viscosity, and thus the loss of solvent due to the solvent not boiling is prevented.

[0068] (Cleaning of production equipment) In the termination stage of the operation of this invention, cleaning of the production equipment is preferred. Cleaning means removing solid matter at the base and deposits at places through which process fluids pass, such as inner walls and the like, atomic ancillary equipment, and heat exchangers to remove heat of reaction, and dissolving or swelling the matter with a solvent, and may also include discharging the solid matter from the process system.

[0069] The solid material in the vapor phase section of the reactor and the like may be dissolved in the solvent after the solid material has been separated from the internal walls of the devices, and the solvent may be directly injected into the material before it dissolves in the solvent. Referring to the example of low polymerization (oligomerization) to 1-hexene, which is an ethylene trimer as an alpha olefin oligomer using ethylene as the alpha olefin, the method for cleaning the equipment for producing alpha olefin oligomers will be described. Alpha olefin is not limited to ethylene and alpha olefin oligomers are not limited to 1-hexene, and the following cleaning method may also be carried out in cases where other alpha olefins are produced as raw materials or other alpha olefin oligomers.

[0070] Cleaning of the reactor and the like is carried out by circulating the solvent in the reactor 10, pipe 11, discharge tank 20, pipe 22, ethylene separation column 30, pipe 33, alkali separation column 40, pipe 41, 1-hexene separation column 50, solvent purification pipes 52 and second supply pipes 13, dissolving the polymers mainly into the reactor 10 in the solvent and extracting the polymers dissolved in the solvent from the piping 42 of the lower part of the high-boiling material separation column 40.

[0071] In addition, as a cleaning operation of the heat exchanger for removing the heat of reaction, an operation of introducing the solvent from a lower nozzle and extracting it from an upper nozzle or an operation of introducing the solvent from a spray nozzle and extracting it from a lower nozzle may also be considered. In this method, cleaning is completed without opening the reactor after the low polymerization (oligomerization) reaction of the alpha olefin is completed, so that this method is preferable because various operations involved in opening the equipment can be eliminated and heat generation from the catalyst residue in the solids, which may be caused by opening the reactor, can be suppressed.

[0072] As a temperature of the solvent used in cleaning, the temperature can be appropriately adjusted depending on the partial pressure of the alpha olefin material at the time of cleaning, but the temperature is preferably from 100°C to 250°C, more preferably from 110°C to 200°C, and particularly preferably from 130°C to 190°C. The concentration of crude alpha olefin in the solvent used during cleaning is given by dividing the weight (kg / Hr) of alpha olefin dissolved in the solvent by the amount of solvent (kg / Hr) and expressing the product as a percentage. The concentration is preferably from 0 to 16% by weight, and more preferably from 1 to 8% by weight. Examples

[0073] The invention will be further described in more detail with reference to the following examples. Without departing from the scope or spirit of the invention, it is to be understood that the invention is not limited by and to the following examples. (Example 1) >Production step structure< Figure 1 shows a production flow. There is a thoroughly mixed and agitated reactor 10 in which ethylene undergoes low polymerization in the presence of a catalyst, a discharge tank 20 which removes unreacted ethylene gas from a reaction liquid extracted from the reactor 10, an ethylene separation column 30 which separates ethylene in the reaction liquid extracted from the discharge tank 20, a high-boiling material separation column which separates a high-boiling material in the reaction liquid extracted from the ethylene separation column 30, and a 1-hexene separation column 50 which distills the reaction liquid extracted from the top of the high-boiling material separation column 40 to separate 1-hexene, and there are also lines 21 (tubes) and 12 (primary tube tubes) which separate unreacted ethylene from the discharge tank 20 and condenser 16 to the reactor 10 via a compressor 17. Also lines 52 (solvent pipe lines) and 13 (second supply pipe c) which transport the separated solvent in the 1-hexene separation column 50 to the reactor 10.

[0074] >Conditions in stable operation (production operation step) < From the first supply pipes 12, unreacted ethylene from the discharge tank 20 and the ethylene separation column 30 is continuously supplied to the reactor 10 via the compressor 17 together with the ethylene newly supplied from the ethylene transfer pipes 12. In addition, from the second supply pipe 13, the recycled n-heptane solvent separated in the 1-hexene separation column 50 is continuously supplied to the reactor 10 at a flow rate of 25 kg / h, by passing through the solvent drum 60 (0.1 MPa nitrogen sealing).

[0075] After the tubular catalyst 13a, an n-heptane solution containing chromium(III) 2-ethylhexanoate and 2,5-dimethylpyrrole (b) is supplied at a flow rate of 0.04 L / Hr and continuously supplied to the reactor 10 through the second pipe 13. In addition, a nitrogen hydrocarbon solution of ethyl aluminum (c) is continuously supplied at a flow rate of 0.04 L / Hr from the third supply pipe 14 to the reactor 10. In addition, a heptane solution of hexachloroethane (d) is continuously supplied at a flow rate of 0.02 L / Hr from the fourth supply pipe 15 to the reactor 10.

[0076] The catalyst component solution is sealed from the tanks (not shown in the figure) with 0.1 nm MPa. Meanwhile, the catalysts are continuously fed to the reactor 10 so that the molar ratio of the components in the reactor is as follows: (a):(b):(c):(d) = 1:25:80:5. The reaction liquid is continuously extracted from the reactor 10 with 2-ethylhexanol in a molar ratio of 3.3 to triethylaluminum (c) added from the deactivator supply pipes 11 and then supplied to the 1-hexene separation column 50 via the discharge tank 20, the ethylene separation column 30, the pipe 32 and the high-boiling material separation column 40.

[0077] The large boiling material separation column 40 was a conventional pressure distillation column in which the concentration section was made of 2.8 m thick material packed material and the recovery section was made of real four-digit blue sheets and operated under reflux ratio conditions of 0.6. The continuous polymerization reaction of low ethylene was carried out at 30°C under a reaction pressure of 0.7 MPa for 30 days. This was followed by a cleaning operation at a reactor liquid temperature of 140°C under a maximum reactor pressure of 3.0 MPa.

[0078] >Operation termination step < The supply of catalysts (a), (b), (c) and (d) from the catalyst supply pipes 13a, the third supply pipes 14 and the fourth supply pipes 15 to the reactor was terminated and n-heptane as solvent was still circulated in the system at 25 kg / h. To prevent the temperature drop by the termination of the reaction, the solvent was heated with the heat exchanger provided in the tubes 13 until the reactor liquid temperature was 140°C. At this time, the pressure in the reactor was 7.0 MPa.

[0079] Thereafter, the feed plate was moved to the high boiling separation column 40 from the fourth plate position counted from the lower part of the column (temperature 101°C) to the lower part of the column (temperature 157°C), and the operation was carried out under reflux conditions at a ratio of 1.0. The reactor cleaning operation was carried out in conjunction with each of the operation termination steps. While maintaining the temperature at 140°C, the pressure was reduced from 7.0 MPa to 5.0 MPa in about 1 hour. After the pressure was reduced to 5.0 MPa, the liquid sample (1) was collected from the bottom of the ethylene separation column 30 after about 10 hours. After that, while maintaining the temperature at 140°C, the pressure was reduced from 5.0 MPa to 3.0 MPa in about 1 hour. After the pressure was reduced to 3.0 MPa, the liquid sample (2) was collected from the bottom of the ethylene separation column 30 after about 10 hours. During this period, no flooding tendency was observed in the boiling material separation column 40 and the operation could be carried out stably.

[0080] After the samples were subjected to sealed samples in a metal container, the samples were cooled to room temperature, and after measuring the weight of the collected liquid, the total polymers in the liquid were filtered. The filtered polymers were dried at 80°C under vacuum for 1 hour using a pressure dryer, and their weights were measured after cooling. In addition, according to the molecular weight of the polymers, the molecular weight distribution of polystyrene was determined on a Waters GPCV 2000 gel permeation chromatograph, and the amount of polymers with a molecular weight of 100,000 or more was determined by multiplying the weight of the filtered polymers by the ratio of polymers with a molecular weight of 100,000 or more. The polymer concentration in the liquid was calculated by dividing the measured polymer amount (g) by the weight (g) of the liquid.

[0081] By the above method, in order to understand the composition of the liquids supplied to the high-boiling material separation column 40, as a result of sampling the liquid from the bottom of the ethylene separation column 30 and measuring the concentration of polymers having a molecular weight of 100,000 or more in n-heptane, a concentration of 610 ppm was obtained in sample (1) and a concentration of 1110 ppm in sample (2). >End of production and inspection operations open <

[0082] After the circulation in the system was terminated, the equipment was stopped and the high-boiling separation column 40 was opened and subjected to internal inspection, and curved polymers were observed on the supply plate and other plates without deterioration. Table 1 shows the results.

[0083] (Comparative Example 1) The operation was carried out in the same manner as in Example 1, except that no feed plate switching was performed in the high-boiling material separation column 40, the reactor pressure was maintained at 7.0 MPa in the purge, and as a liquid sample from the bottom of the ethylene separation column 30, sample (3) was collected after about 20 hours after the catalyst supply was terminated. The high-boiling material separation column 40 showed a tendency to flood, and as a result of the open inspection, corrosion was observed in the feed plate. Table 1 shows the results. As a result of measuring the concentration of polymers having a molecular weight of 100,000 or more in n-heptane, the concentration of sample (3) was found to be 120 ppm.

[0084] (Reference Example 1) The continuous polymerization reaction of low ethylene was carried out under the same conditions as in Example 1 for 70 days, and in Sample (4) by the method described in Example 1 to measure the polymer concentration in the bottom of the ethylene separation column 30 at that time there was no contact of the flood in the melt separation column 40 and as a result no open inspection was observed on the supply plate. Table 1 shows the results. As a result of measuring the concentration of polymers having a molecular weight of 100,000 or more in n-heptane, the sample concentration in the various samples was 50 ppm. Table 1 shows the results.

[0085] [Table 1] Example 1 Comparative Example 1 Reference 1 Polymer Concentration * Liquid supplied to high-boiling separation column 40 ppm Weight 1110 120 50 High-boiling separation column display page 40 - Bottom of page 4 from bottom of page 4 from bottom of page High-boiling separation column feed page temperature 40  C 157 101 101 High-boiling separation column flooding 40 - None observed trending None Sheet shedding - None observed None * Molecular weight 100,000 or more

[0086] In Example 1, since the change of the feed plate of the high-boiling separation column 40 was carried out at the end of the operation, no flooding occurred in the alkali separation column 40 and no loading of polymers onto the screening trays was observed. However, in the comparative comparison of Example 1, since the change of the feed plate of the high-boiling separation column 40 was not carried out, although the polymer concentration was 100 ppm or more, flooding was observed, and when the high-boiling separation column 40 was subjected to open inspection, deterioration due to adhesion of curved polymers was observed on the lower part of the supply plate. In Reference Example 1, since the polymer concentration entering the high-boiling 40 separation column is 100 ppm by weight or less, it indicates that flooding does not occur.

[0087] (Reference Example 2) The production and termination steps were carried out under the same conditions as in Example 1. After every 8 hours, 16 hours, 32 hours, 40 hours and 56 hours from the time the reactor liquid temperature reached 140°C and its pressure reached 3.0 MPa, the liquid was collected as a sample with a tank from the bottom of the ethylene separation column 30 and the polymer concentration was measured. On the other hand, sampling was carried out into a glass container while the liquid below 0.5 MPa in the bottom was exhausted to an atmospheric pressure through a valve (i.e. under rapid cooling and shaking conditions) and the shape of the precipitated polymers was observed. Table 2 shows the results.

[0088] [Table 2] Table 2 Sample No. Polymer Concentration* [ppm by weight] Polymer Form Precipitated Under Flushing Conditions 1 1030 Bulk Form and Filament Form 2 370 Bulk Form and Filament Form 3 120 Filament Form 4 90 Granular Form 5 20 Granular Form * Molecular weight 100,000 or more

[0089] In samples 1 and 2, crushed polymer deposits with a diameter of several centimeters and filamentous polymers with a length of several centimeters were confirmed. Filamentous polymers with a length of several centimeters were observed in sample 3, and granular polymers with a diameter of several millimeters or less were observed in samples 4 and 5. (Example Reference 3)

[0090] In the alpha-olefin oligomer production equipment, 0.3 g of the polymers were attached to the inner wall of the reactor. A round glass flask containing 150 g of 1-decane was added and the temperature was raised to 160°C to complete solution. After that, while still standing and cooling at room temperature, the granule-shaped polymers with a diameter of a few millimeters or less were dispersed in the solution in a spray state. Next, when the molecular weight distribution of the polymers was measured in the same manner as in Example 1, the concentration of polymers having a molecular weight of 100,000 or more was found to be 1590 ppm by weight.

[0091] As a result, in a solution in which the concentration of polymers having a molecular weight of 100,000 or more is 1590 ppm by weight or less, it has been found that the polymers precipitate only in granular form, when the polymers are in a stationary state during precipitation. It is clear from the above text that when the concentration of polymers with a molecular weight of 100,000 or more in the supply liquid exceeds 100 ppm by weight, the large polymers precipitate in the supply liquid section of the distillation column and cause flooding of the distillation column, but the flooding caused by loading large polymers can be prevented by changing the position of the feed panel to a position lower than the stable operation position (production operation stage).

[0092] While the invention has been described in detail with reference to specific configurations thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof. This application is based on Patent Application No. 2015-062877, filed March 25, 2015, the contents of which are incorporated herein by reference. Explanation of reference marks

[0093] 10 reactors 10a Stirring machine 11, 22, 32, 33, 41, 42, 51 tubes 11a Drain supply pipes 12 Primary supply pipes 12a Ethylene supply pipes 13 Second supply pipe 13a Catalyst supply pipes 14 Third supply pipes 15 Fourth supply pipe 21, 31 circulation pipes 16 Condenser 17 compressors 20 refueling tanks 30 Ethylene separation columns 40 High-boiling material separation columns 50 1-Hexene Separation Column 52 Solvent purification tubes 60 halal drums Complaint [Claim 1] A method for producing a low alpha olefin polymer includes a production operation step in which alpha olefin, which is a raw material, is supplied to a reactor and subjected to a low polymerization reaction in the presence of a catalyst and a solvent, and a reaction product containing low alpha olefin polymer, which is a normal product, is supplied as a feed liquid to a distillation column for product purification; and a termination operation step in which the supply of the catalyst to the reactor is stopped and the solvent is supplied as a liquid between the reactor and the distillation column, Wherein the position of supplying the supply liquid to the distillation column in the termination stage of the operation is at a lower position than the position of supplying the supply liquid to the distillation column in the production stage of the operation. [Claim 2] The method for producing a low alpha olefin polymer according to claim 1, wherein in the termination step, after the catalyst is supplied to the reactor, the position of the supply liquid to the distillation column is changed to a lower position than the position of the supply liquid to the distillation column in the production step. [Claim 3] The method for producing a low alpha olefin polymer according to claim 1 or 2, wherein in the liquid supply to the distillation column in the termination step, the concentration of polymers having a molecular weight of 100,000 or more is 100 ppm by weight relative to the solvent or more. [Claim 4] The method for producing a low alpha olefin polymer according to any one of claims 1 to 3, wherein the temperature inside the distillation column at the position of supplying the feed liquid to the distillation column in the termination stage of the operation is 110°C or higher. [Claim 5] A method of producing a low alpha olefin polymer according to any one of claims 1 to 4, wherein the termination step comprises creating a partial pressure of the alpha olefin in a portion of the vapor phase of the reactor to reduce it in at least two stages. [Claim 6] The method for producing a low alpha olefin polymer according to any one of claims 1 to 5, wherein the termination step comprises cleaning at least one of the reactor and the heat exchanger to remove the heat of reaction. [Claim 7] The method for producing a low alpha olefin polymer according to any one of claims 1 to 6, wherein the position of supplying the prepared liquid to the distillation column is at the end of the operation of the bottom section of the distillation column. [Claim 8] The method for producing a low alpha olefin polymer according to any one of claims 1 to 7, wherein the distillation column comprises a boiling material separation column. [Claim 9] The method for producing a low alpha olefin polymer according to claim 8, wherein the distillation column comprises an alpha olefin separation column and a product separation column. [Claim 10] The method for producing a low alpha olefin polymer according to claim 8 or 9, wherein the high boiling point components extracted from the lower column of the high boiling point separation column are supplied to the high boiling point tank in the production operation stage and are supplied as a feed liquid to the lower part of the high boiling point separation column section in the termination operation stage. [Claim 11] The method for producing a low alpha olefin polymer according to claim 1 to 10, wherein the alpha olefin which is the raw material is ethylene and the polymer which is the target product is an alpha olefin having 4 to 10 carbon atoms. [Claim 12] An apparatus for separating low alpha olefin polymer and polymers from a low alpha olefin polymer solution, a solvent and polymers, wherein the apparatus has two or more solution source ports at different vertical positions. [Claim 13] The apparatus of claim 12, wherein the position of the supply port near the top column, which is above the supply port, is higher than the end of the lowest tray or filled material, and the position of the supply port near the bottom column, which is the lowest supply port, is lower than the end of the lowest tray or filled material. [Claim 14] The device according to claim 12 or 13, wherein the low alpha olefin polymer is a polymerized product of ethylene and an alpha olefin having 4 to 10 carbon atoms. Summary of the invention An object of the present invention is to provide a method for suppressing precipitation of high-concentration polymers dissolved in a solvent in the termination stage and suppressing clogging of the apparatus by polymers even when high-concentration polymers precipitate. The present invention relates to a method for producing a low-alpha olefin polymer comprising a production stage and a termination stage, wherein the supply position of the liquid supplied to the distillation column in the termination stage is lower than the supply position of the liquid supplied to the distillation column in the production stage.

Claims

ادعانامه [ادعای 1] یک روش برای تولید پلیمر کم اولفین آلفا شامل گام عملیاتی تولید که در آن یک کاتالیزور و یک حلال به راکتور خوراک ‌دهی می‌شوند ، و یک اولفین آلفا که یک ماده خام است به یک راکتور تامین می شود و تحت یک واکنش پلیمریزاسیون کم در حضور کاتالیزور و حلال و یک محصول واکنش حاوی پلیمر کم ولفین آلفا که یک محصول عادی است به عنوان یک مایع تامین به یک ستون تقطیر برای خالص‌سازی محصول تامین می شود؛ و یک مرحله خاتمه عملیاتی که در آن عرضه کاتالیزور به راکتور متوقف می شود و حلال بعنوان مایع تامین بین راکتور و ستون تقطیر به گردش در می‌آید ، که در آن موقعیت تامین مایع تامین به ستون تقطیر در مرحله خاتمه عملیات در موقعیت پایین تر از موقعیت عرضه مایع تامین به ستون تقطیر در مرحله عملیات تولید است. [ادعای 2] روش تولید پلیمر کم اولفین آلفا برطبق ادعای شماره 1، که در آن مرحله خاتمه عملیات، پس از عرضه کاتالیزور به راکتور، خاتمه می یابد، موقعیت عرضه مایع تامین به ستون تقطیر به یک موقعیت پایین تر از موقعیت عرضه مایع تامین به ستون تقطیر در مرحله عملیات تولید. تغییر می کند. [ادعای 3]روش تولید پلیمر کم اولفین آلفا برطبق ادعای 1 یا 2، که در آن در تامین مایع به ستون تقطیر در مرحله خاتمه عملیات، غلظت پلیمرهای دارای وزن مولکولی 100،000 یا بیشتر 100 ppm در وزن نسبت به حلال یا بیشتر است. [ادعای 4] روش تولید پلیمر کم اولفین آلفا برطبق هر یک از ادعاهای 1 تا 3، که در آن دمای داخل ستون تقطیر در موقعیت عرضه مایع تامین به ستون تقطیر در مرحله خاتمه عملیات 110 درجه سانتیگراد یا بالاتر است. [ادعای 5] روش تولید پلیمر کم اولفین آلفا برطبق هر یک از ادعاهای 1 تا 4، که در آن مرحله خاتمه عملیات شامل ایجاد فشار جزئی اولفین آلفا در بخشی از فاز بخار راکتور می شود تا حداقل در دو مرحله کاهش یابد. [ادعای 6] روش تولید پلیمر کم اولفین آلفا برطبق هر یک از ادعاهای 1 تا 5، که در آن مرحله خاتمه عملیات شامل تمیز کردن حداقل یکی از راکتور و مبدل حرارتی برای حذف گرمای واکنش است. [ادعای 7] روش تولید پلیمر کم اولفین آلفا برطبق هر یک از ادعاهای 1 تا 6، که در آن موقعیت عرضه مایع تهیه شده به ستون تقطیر در مرحله خاتمه عملیات، بخش پایین ستون تقطیر است. [ادعای 8] روش تولید پلیمر کم اولفین آلفا برطبق هر یک از ادعاهای 1 تا 7، که در آن ستون تقطیر حاوی ستون جدایی ماده جوش است. [ادعای 9]روش تولید پلیمر کم اولفین آلفا برطبق ادعای شماره 8، که در آن ستون تقطیر حاوی ستون جداسازی اولفین آلفا و ستون جداسازی محصول است. [ادعای 10]روش تولید پلیمر کم اولفین آلفا برطبق ادعای شماره 8 یا 9، که در اجزایی که دارای نقطه جوش بالا هستند استخراج شده از بخش پایین ستون جداسازی ماده جوش بالا به تانک ماده جوش بالا در مرحله عملیاتی تولید تامین می شود و به قسمت پایین بخش ستون جدایی ماده جوش بالا تامین می شود. [ادعای 11]روش تولید پلیمر کم اولفین آلفا برطبق ادعای شماره 1 تا 10، که در آن اولفین آلفا که مواد خام است اتیلن است و پلیمری که محصول هدف است یک اولفین آلفا با 4 تا 10 اتم کربن است.

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