Reaction product promoter for trialkylaluminum

Abstract

To provide a reaction product promoter for trialkylaluminum, a production method therefor, and an application thereof.SOLUTION: The present invention provides a reaction product promoter for trialkylaluminum, wherein: trialkylaluminum is reacted and produced in an organic solvent; the trialkylaluminum is removed through distillation; solid matter remaining in the resulting slurry is recovered; the recovered solid matter is hydrolyzed to yield an organic layer; the organic layer is purified; and the recovered organic solvent is used to provide the trialkylaluminum reaction product promoter.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention provides a trialkylaluminum reaction product promoter, a method for its preparation and use. [Background technology]

[0002] Since alkylaluminum is a typical Lewis acid and has high reactivity, it is used as a polymerization catalyst and a raw material for higher alcohols. Among them, monoalkylaluminum, dialkylaluminum, and trialkylaluminum can generally be obtained by reacting aluminum powder or an alloy containing aluminum with an alkyl halide, and high purity products can be obtained by distillation. Trialkylaluminum in particular has high product value and is also a raw material for electronic materials and semiconductors, which are in extremely high demand in recent years, so the establishment of an efficient production method is desired.

[0003] Trialkylaluminum is an aluminum sesquihalide (Me3Al2X) obtained by reacting aluminum powder with alkyl halides (e.g., methyl chloride, methyl bromide). 3、X=Cl, Br) can be obtained by reducing it with an alkali metal or an alkaline earth metal (Non-Patent Document 1; Patent Document 1). As another method, it can also be obtained by reacting an alloy containing aluminum with an alkyl halide in an organic solvent in the presence of a catalyst (Patent Document 2). Iodine and nitrogen-containing organic compounds are known as reaction promoters for the production of these trialkylaluminums (Patent Document 2). It is true that the production of trialkylaluminums can be promoted by adding iodine and nitrogen-containing organic compounds. However, iodine is highly toxic and corrosive, so there are restrictions on how it can be handled, and it is also a substance that is prone to causing trouble. On the other hand, nitrogen-containing organic compounds, such as pyridine, have a pungent odor similar to ammonia, are highly irritating to the eyes and skin, and are highly toxic, so care must be taken in the work environment and when handling them. In recent years, the price of chemical products has been on the rise due to the global rise in energy prices, so the emergence of an accelerator that is not affected by economic circumstances to replace iodine and nitrogen-containing organic compounds has been desired. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent No. 5,380,898 [Patent Document 2] JP 2018-135300 A [Non-patent literature]

[0005] [Non-Patent Document 1] AV Grosse, et.al., J. Org. Chem., 05, 2.106-121 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention provides a trialkylaluminum reaction product promoter, a method for its preparation and use. [Means for solving the problem]

[0007] The present inventors have discovered that in a reaction to produce trialkylaluminum using an organic solvent, if the solids in the slurry remaining in the reaction tank are recovered after the trialkylaluminum is separated and recovered by distillation under reduced pressure, and the organic layer obtained by hydrolyzing the solids is purified by distillation and then reused as the organic solvent for the reaction to produce trialkylaluminum, then surprisingly, the conversion rate of trialkylaluminum is significantly improved compared to a reaction system in which a new organic solvent is used, and the resulting organic solvent can be used as a reaction production promoter for trialkylaluminum.

[0008] Therefore, this application includes the following inventions. (1) A trialkylaluminum reaction accelerator comprising a process comprising: reacting a trialkylaluminum in an organic solvent, distilling off the trialkylaluminum, recovering a solid from the remaining slurry, hydrolyzing the solid to obtain an organic layer, purifying the organic layer, and recovering the organic solvent. (2) The trialkylaluminum reaction product accelerator according to (1), wherein the organic solvent is purified from the organic layer by distillation. (3) The trialkylaluminum reaction product accelerator according to (1) or (2), wherein the solid content in the slurry is recovered by filtration and / or distillation. (4) The trialkylaluminum reaction product accelerator according to (1), wherein the solid content contains the organic solvent in an amount of 1 to 30% by weight. (5) The trialkylaluminum reaction product accelerator according to (1), wherein the hydrolysis of the solid content is carried out by contact with an aqueous acid solution. (6) The trialkylaluminum reaction product accelerator according to (5), wherein the aqueous acid solution is an aqueous hydrochloric acid solution. (7) The trialkylaluminum reaction product accelerator according to (6), wherein the aqueous hydrochloric acid solution has a hydrochloric acid concentration of 1 to 36% by weight. (8) The trialkylaluminum reaction product accelerator according to (1), wherein the organic solvent is a hydrocarbon solvent. (9) The trialkylaluminum reaction product accelerator according to (8), wherein the hydrocarbon solvent is at least one selected from the group consisting of saturated hydrocarbon solvents having 5 to 18 carbon atoms and aromatic hydrocarbon solvents having 6 to 12 carbon atoms. (10) The trialkylaluminum reaction product accelerator according to (9), wherein the hydrocarbon solvent is n-dodecane. (11) The trialkylaluminum reaction production accelerator according to (1), wherein the reaction production of trialkylaluminum is carried out by reacting aluminum and a metal or alloy thereof serving as a reducing agent with an alkyl halide in the organic solvent. (12) The trialkylaluminum reaction product accelerator according to (1), wherein the reaction product of the trialkylaluminum is carried out in the presence of a nitrogen-containing organic compound. (13) The trialkylaluminum reaction product accelerator according to (12), wherein the nitrogen-containing organic compound is a conjugated heterocyclic compound containing at least one nitrogen atom and having a 5-membered ring and / or 6-membered ring skeleton. (14) The trialkylaluminum reaction product accelerator according to (13), wherein the conjugated heterocyclic compound is selected from the group consisting of pyridine, 2-methylpyridine, 4-methylpyridine, 2,6-dimethylpyridine, 2,4,6-trimethylpyridine, 2,6-diethylpyridine, 2,6-diisopropylpyridine, quinoline, isoquinoline, 2,2-bipyridine, and 1-methylimidazole. (15) The trialkylaluminum reaction accelerator according to (1), wherein the reaction of the trialkylaluminum is carried out in the presence of a halogen element. (16) The trialkylaluminum reaction product accelerator according to (15), wherein the halogen element is iodine. (17) The trialkylaluminum reaction product accelerator according to (1), wherein the trialkylaluminum is trimethylaluminum. (18) A method for producing trialkylaluminum, which uses the trialkylaluminum reaction promoter according to (1) as a solvent. (19) The method for producing trialkylaluminum according to (18), wherein the production of trialkylaluminum is carried out by reacting aluminum and a metal or an alloy thereof serving as a reducing agent with an alkyl halide in the trialkylaluminum reaction product accelerator used as a solvent. (20) A method for producing a trialkylaluminum reaction product accelerator, comprising: reacting trialkylaluminum in an organic solvent, distilling off the trialkylaluminum, recovering a solid fraction from the remaining slurry, and purifying an organic layer obtained by hydrolyzing the solid fraction, thereby recovering the organic solvent. (21) The method for producing a trialkylaluminum reaction product accelerator according to (20), wherein the organic solvent is purified from the organic layer by distillation. (22) The method for producing a trialkylaluminum reaction product accelerator according to (20) or (21), wherein the solid content is recovered from the slurry by filtration and / or distillation. (23) The method for producing a trialkylaluminum reaction product accelerator according to (20), wherein the solid content contains the organic solvent in an amount of 1 to 30% by weight. (24) The method for producing a trialkylaluminum reaction product accelerator according to (20), wherein the hydrolysis of the solid content is carried out by contact with an aqueous acid solution. (25) The method for producing a trialkylaluminum reaction product accelerator according to (24), wherein the aqueous acid solution is an aqueous hydrochloric acid solution. (26) The method for producing a trialkylaluminum reaction product accelerator according to (25), wherein the aqueous hydrochloric acid solution has a hydrochloric acid concentration of 1 to 36% by weight. (27) The method for producing a trialkylaluminum reaction product accelerator according to (20), wherein the organic solvent is a hydrocarbon solvent. (28) The method for producing a trialkylaluminum reaction product accelerator according to (27), wherein the hydrocarbon solvent is at least one selected from the group consisting of saturated hydrocarbon solvents having 5 to 18 carbon atoms and aromatic hydrocarbon solvents having 6 to 12 carbon atoms. (29) The method for producing a trialkylaluminum reaction product accelerator according to (28), wherein the hydrocarbon solvent is n-dodecane. (30) The method for producing a trialkylaluminum reaction product accelerator according to (20), wherein the reaction production of trialkylaluminum is carried out by reacting aluminum and a metal or an alloy thereof serving as a reducing agent with an alkyl halide in the organic solvent. (31) The method for producing a trialkylaluminum reaction product accelerator according to (20), wherein the trialkylaluminum is trimethylaluminum. Effect of the Invention

[0009] By using the trialkylaluminum reaction accelerator of the present invention, the production efficiency of trialkylaluminum can be significantly improved, and since the bottoms generated in the reaction generation process of trialkylaluminum are reused, the effects of improving profitability, reducing the amount of organic solvent used, and reducing waste disposal costs can be achieved. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present invention provides a reaction promoter for trialkylaluminum, a method for producing the same and use thereof. Trialkylaluminum includes, for example, trimethylaluminum, triethylaluminum, triisobutylaluminum, etc., and trimethylaluminum is particularly useful industrially.

[0011] The reaction method for producing trialkylaluminum in the present invention is not particularly limited, and may be any method including a step of distillation separation for the purpose of purification after the reaction of trialkylaluminum. Specific reaction methods include, for example, (i) a method of reacting aluminum with a metal or alloy thereof as a reducing agent and an alkyl halide in an organic solvent in the presence of a catalyst to produce trialkylaluminum, (ii) a method of contacting an alkylaluminum halide synthesized from aluminum and an alkyl halide with sodium or magnesium to obtain trialkylaluminum by reduction, and (iii) a method of activating aluminum with alkylaluminum and hydrogen, reacting it with an unsaturated hydrocarbon, and producing trialkylaluminum by a substitution reaction. In all of these methods, aluminum or an alkali metal is used, and therefore unreacted raw materials, inorganic salts by-produced in the reaction, and organic solvent remain in the bottom residue, so a step of treating the bottom residue is essential.

[0012] Since alkylaluminum remains in these residues, it is necessary to pay close attention to the treatment method and handling. In particular, alkylaluminum spontaneously ignites when it comes into contact with air, and when it comes into contact with water, it reacts explosively, generates heat, and thermally decomposes, causing a chain reaction explosion, which may lead to serious accidents and disasters. Therefore, it is desirable to propose an appropriate treatment or an effective treatment method for the residue slurry. The so-called residue slurry remaining in the reaction apparatus after this distillation separation process can be separated into solids and liquids by using a conventional separation method such as filtration, sedimentation, centrifugation, distillation, etc., and each of them can be recovered. Specifically, examples include cake filtration using a filter material, distillation using a distillation tower, centrifugation or centrifugal sedimentation (decanter), sedimentation concentration such as liquid cyclone or settler, and the like, and these may be combined to separate and recover. Here, the solids may contain a certain amount of the organic solvent used in the reaction production of trialkylaluminum, for example, 1 to 30% by weight.

[0013] The liquid can be recovered and reused as an organic solvent in the reaction production process of trialkylaluminum. On the other hand, the solids contain hazardous substances such as alkylaluminum, and therefore must be rendered harmless safely and efficiently. In the present invention, the solids separated and recovered from the above slurry are hydrolyzed to separate into an organic layer and an aqueous layer. An acid selected from inorganic acids such as hydrochloric acid, nitric acid, sulfuric acid, and phosphoric acid is used for the hydrolysis. In relation to alkylaluminum, an aqueous hydrochloric acid solution is particularly preferred, and an aqueous solution of 1 to 36% by weight, particularly preferably 5 to 30% by weight, and most preferably 5 to 10% by weight is used. The amount of the aqueous acid solution used for hydrolysis is not particularly limited, and it is ideal to use an excess amount of the aqueous acid solution, but in consideration of the subsequent neutralization process, it is preferable to set an upper limit on the amount of the aqueous acid solution used. Although not particularly limited, the aqueous acid solution and the solids are mixed and contacted at a weight ratio of 20:1 to 1:1, preferably 10:1 to 3:1.

[0014] The aqueous layer obtained by hydrolysis of the above-mentioned slurry is neutralized with an aqueous alkali solution, etc., as necessary, and then discarded. Examples of the aqueous alkali solution include sodium hydroxide, potassium hydroxide, and calcium hydroxide. On the other hand, the organic layer obtained by hydrolysis of the above-mentioned slurry has an unpleasant odor and cannot be reused as an organic solvent for the reaction production of trialkylaluminum. The present inventor then attempted to further purify this organic layer, and reused the purified organic solvent in the reaction for the production of trialkylaluminum. Surprisingly, the conversion rate of trialkylaluminum was significantly improved compared to the reaction system using a new organic solvent. Therefore, it was found that the organic solvent recovered in this manner is effective as a reaction production promoter for trialkylaluminum. The significant improvement here means a statistically significant improvement, and can mean, for example, an improvement of the conversion rate of 5% or more, preferably 10% or more, and more preferably 20% or more compared to a new organic solvent.

[0015] The method for purifying and recovering the trialkylaluminum reaction product accelerator of the present invention from the organic layer resulting from the hydrolysis of the solid content is not particularly limited, but specifically, a conventionally known separation method such as filtration, sedimentation, centrifugation, distillation, etc. can be used. For example, cake filtration using a filter medium, distillation using a distillation column, centrifugation or centrifugal sedimentation (decanter), sedimentation concentration using a liquid cyclone or settler, etc. can be exemplified, and recovery may be performed by combining these.

[0016] The trialkylaluminum reaction accelerator of the present invention can be reused for trialkylaluminum reaction and then recovered, and can be reused as a trialkylaluminum reaction accelerator again. Therefore, the recovered solvent can be used repeatedly, i.e., it can be used semi-permanently as a trialkylaluminum reaction accelerator.

[0017] An especially preferred method for producing trialkylaluminum is the above method (i), in which aluminum, a metal or alloy thereof serving as a reducing agent, and an alkyl halide are reacted in an organic solvent in the presence of a catalyst to produce trialkylaluminum.

[0018] Specific examples of the metal that serves as the reducing agent include alkali metals such as lithium, sodium, and potassium, and alkaline earth metals such as magnesium, calcium, barium, and strontium. Magnesium is particularly preferred as the metal that serves as the reducing agent. Examples of alloys of aluminum and a metal that serves as the reducing agent include lithium alloys, sodium alloys, potassium alloys, magnesium alloys, calcium alloys, barium alloys, and strontium alloys. Aluminum-magnesium alloys are particularly preferred as the alloy. When using an aluminum-magnesium alloy, it may be an alloy containing 20 to 99% by weight of magnesium, for example, and the magnesium content is more preferably 30 to 99% by weight, and even more preferably 35 to 99% by weight.

[0019] Although there is no particular limitation, aluminum, a metal serving as a reducing agent, or an alloy thereof can be pulverized into a powder form for use in the reaction. For the pulverization, a conventionally known general alloy pulverization method such as a ball mill, a bead mill, or a jet mill can be used. Although there is no particular limitation, the particle size of these powders is preferably 1 μm to 1000 μm, and more preferably 5 to 500 μm.

[0020] Examples of the alkyl halide include methyl chloride, methyl bromide, methyl iodide, ethyl chloride, ethyl bromide, ethyl iodide, isobutyl chloride, isobutyl bromide, isobutyl iodide, etc. This reaction is carried out by adding an alkyl halide to aluminum and a metal or alloy thereof serving as a reducing agent, but it is also possible to mix aluminum and a metal or alloy thereof serving as a reducing agent with a part of the alkyl halide in advance in a reaction vessel, and then add the remaining alkyl halide after the reaction has started.

[0021] The amount of alkyl halide used is not particularly limited, but may be 3 mol or more per mol of aluminum in the aluminum or its alloy, preferably 3 mol or more and 5 mol or less, and more preferably 3 mol or more and 4 mol or less.

[0022] The reaction may be carried out by any of batch operation, semi-batch operation, and continuous operation without any particular limitation. As the reaction apparatus, a vertical or horizontal pressure-resistant reaction vessel may be used. For example, a pressure-resistant autoclave equipped with a stirrer may be used. As the stirring blade to be used, any commonly known type may be used, for example, a propeller, a turbine, a triple-swept blade, a large blade, etc. Furthermore, a homogenizer or the like may be used.

[0023] The alkyl halide may be fed into the reactor continuously or intermittently. When the alkyl halide is fed continuously, the reaction is an exothermic reaction, so it is necessary to control the amount fed and the heating temperature to prevent an excessive rise in temperature. When the alkyl halide is fed intermittently, it is preferable to heat the alkyl halide after feeding and carry out the reaction until the exothermic reaction is completed. When the alkyl halide is fed intermittently, the above reaction may be repeated. In the present invention, it is preferable to suspend aluminum and a metal or an alloy thereof serving as a reducing agent in a solvent to form a slurry and feed the alkyl halide.

[0024] The reaction temperature is not particularly limited, but is preferably 20° C. to 200° C., more preferably 60° C. to 160° C. The reaction time is not particularly limited, but is preferably 1 to 12 hours, more preferably 3 to 8 hours.

[0025] A solvent can be used for the reaction, and examples of the solvent include hydrocarbon solvents. The hydrocarbon solvent is preferably a hydrophobic and poorly reactive hydrocarbon solvent, and examples of such organic solvents include at least one selected from the group consisting of saturated hydrocarbon solvents and aromatic hydrocarbon solvents.

[0026] The hydrocarbon solvent preferably has a boiling point in the range of 30° C. to 250° C. The saturated hydrocarbon solvent may be a substituted or unsubstituted linear saturated hydrocarbon having 5 to 18 carbon atoms, or a substituted or unsubstituted cyclic saturated hydrocarbon. Paraffin oil or a mixture thereof may also be included.

[0027] Specific examples of the saturated hydrocarbon solvent include n-pentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane, n-undecane, n-dodecane, n-tridecane, n-tetradecane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclodecane, o-menthane, m-menthane, p-menthane, decahydronaphthalene, and paraffins C n H2n+2 , Isoparaffins C n H 2n+2 Examples include n-dodecane.

[0028] The aromatic hydrocarbon used as the solvent is preferably an aromatic hydrocarbon having a substituent selected from the group consisting of an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, and an alkylene group having 2 to 8 carbon atoms, or an unsubstituted aromatic hydrocarbon.

[0029] Examples of alkyl groups having 1 to 8 carbon atoms which are substituents of aromatic hydrocarbons include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, n-hexyl, isohexyl, neohexyl, tert-hexyl, n-heptyl, isoheptyl, neoheptyl, tert-heptyl, n-octyl, isooctyl, neooctyl, and tert-octyl groups.

[0030] Examples of the cycloalkyl group having 3 to 8 carbon atoms which is a substituent of an aromatic hydrocarbon include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl groups.

[0031] Examples of the alkylene group having 2 to 8 carbon atoms which is a substituent of an aromatic hydrocarbon include ethylene, propylene, butylene, pentene, hexene, heptene, and octene groups.

[0032] Specific examples of the aromatic hydrocarbons include cumene, o-cumene, m-cumene, p-cumene, propylbenzene, n-butylbenzene, sec-butylbenzene, tert-butylbenzene, 1-phenylpentane, 1-phenylheptane, 1-phenyloctane, 1,2-diethylbenzene, 1,4-diethylbenzene, mesitylene, 1,3-di-tert-butylbenzene, 1,4-di-tert-butylbenzene, di-n-pentylbenzene, tri-tert-butylbenzene, cyclohexylbenzene, indane, and tetralin.

[0033] The amount of the solvent used is not particularly limited, but can be, for example, in the range of 0.1 mol to 100 mol, and preferably in the range of 1 mol to 10 mol, per mol of aluminum or aluminum of the alloy thereof.

[0034] The reaction of aluminum and the reducing metal or their alloy with the alkyl halide may be carried out in the presence of a nitrogen-containing organic compound. The nitrogen-containing organic compound is a compound containing one or more nitrogen atoms. Examples of the nitrogen-containing organic compound include amine compounds, heterocyclic compounds containing a nitrogen atom, and amide compounds. Two or more of these nitrogen-containing organic compounds may be used in combination.

[0035] Examples of the amine compound include an aliphatic amine compound, an aromatic amine compound, and a heterocyclic compound containing a nitrogen atom.

[0036] Examples of the aliphatic amine compound include primary amines such as methylamine, ethylamine, butylamine, amylamine, isoamylamine, cyclohexylamine, hexamethylenediamine, spermidine, spermine, and amantadine, secondary amines such as dimethylamine, diethylamine, diisopropylamine, dibutylamine, diisobutylamine, diamylamine, and dicyclohexylamine, and tertiary amines such as trimethylamine, triethylamine, tributylamine, triisobutylamine, triethanolamine, tricyclohexylamine, and N,N-diisopropylethylamine. In the present invention, it is particularly preferable to use a tertiary amine.

[0037] Examples of the aromatic amine compound include aniline, N,N-dimethylaniline, phenethylamine, toluidine, catecholamine, and 1,8-bis(dimethylamino)naphthalene.

[0038] Examples of the heterocyclic compound containing a nitrogen atom include saturated heterocyclic compounds such as pyrrolidine, piperidine, piperazine, morpholine, quinuclidine, 1,4-diazabicyclo[2.2.2.]octane, and pyrrole, and unsaturated heterocyclic compounds such as pyrazole, imidazole, pyridine, 2-methylpyridine, 2,6-dimethylpyridine, 2,4,6-trimethylpyridine, 2,6-diethylpyridine, 2,6-diisopropylpyridine, 2,2-bipyridine, pyridazine, pyrimidine, pyrazine, oxazole, thiazole, 4-dimethylaminopyridine, indole, quinoline, isoquinoline, purine, imidazole, 1-methylimidazole, 1-ethylimidazole, and 1-butylimidazole. In the present invention, it is preferable to use unsaturated heterocyclic compounds.

[0039] The amount of the nitrogen-containing organic compound present may be 1 mol or less per mol of aluminum in the aluminum or its alloy, but is preferably in the range of 0.001 mol to 0.2 mol, more preferably 0.001 mol to 0.1 mol, and even more preferably 0.01 mol to 0.08 mol.

[0040] In the reaction of aluminum and a metal or alloy thereof serving as a reducing agent with an alkyl halide, at least one additive selected from the group consisting of an alkylaluminum compound, iodine, bromine and a halogenated compound can be present in addition to the nitrogen-containing organic compound.

[0041] Examples of the alkylaluminum compound include trialkylaluminum, alkylaluminum sesquichloride, dialkylaluminum chloride, and alkylaluminum dichloride. The addition of the alkylaluminum compound improves the trialkylaluminum selectivity and trialkylaluminum conversion rate in the above reaction. The alkylaluminum compound used as an additive can be the mixture of trialkylaluminum and dialkylaluminum chloride, which are the reaction products of the above reaction, as is.

[0042] The amount of the alkylaluminum compound added is preferably in the range of 0.001 mol to 0.1 mol, more preferably 0.01 mol to 0.05 mol, per mol of aluminum in the aluminum or aluminum alloy.

[0043] Examples of halogenated compounds as additives include methyl iodide, ethyl iodide, ethyl bromide, and methyl bromide. By adding iodine, bromine, and / or halogenated compounds, the conversion rate of aluminum or its alloy in the above reaction is improved, and the trialkylaluminum selectivity and trialkylaluminum conversion rate are improved.

[0044] The amount of iodine, bromine, or a halogenated compound added is preferably in the range of 0.001 mol to 0.20 mol, more preferably in the range of 0.01 mol to 0.10 mol, per mol of aluminum in the aluminum or its alloy.

[0045] As the additive, it is preferable to use an alkylaluminum compound in combination with iodine, bromine, or a halogenated compound and a nitrogen-containing organic compound, since this improves the conversion rate of aluminum or its alloy, and also improves the trialkylaluminum selectivity and trialkylaluminum conversion rate. In particular, a combination of a dialkylaluminum halide as the alkylaluminum compound, iodine, and 2,6-dimethylpyridine as the nitrogen-containing organic compound is preferable, and when the alkyl halide as the raw material is methyl chloride and the trialkylaluminum as the product is trimethylaluminum, it is preferable that the dialkylaluminum halide is dimethylaluminum chloride, and the additive is a combination of dimethylaluminum chloride, iodine, and 2,6-dimethylpyridine.

[0046] All documents mentioned herein are incorporated by reference in their entirety.

[0047] The following examples of the present invention are for illustrative purposes only and do not limit the technical scope of the present invention. The technical scope of the present invention is limited only by the claims. The present invention can be modified, for example, by adding, deleting, and replacing the constituent elements of the present invention, without departing from the spirit of the present invention. EXAMPLES

[0048] The present invention will be described in more detail below with reference to examples, but these are not intended to limit the present invention in any way.

[0049] Step (1) (Use new dodecane) In a 1.5L autoclave that had been purged with nitrogen, 92.59g of AlMg alloy powder (Al: 39.35g, 1.46mol, Mg: 53.24g, 2.19mol), 10.0g of iodine (0.0270mol per 1mol of aluminum in the AlMg alloy), 6.02g of 2,6-dimethylpyridine (0.0385mol per 1mol of aluminum in the AlMg alloy), 3.34g of dimethylaluminum chloride (DMAC) (0.0248mol per 1mol of aluminum in the AlMg alloy), and 313.66g of n-dodecane were added. The temperature was then raised to 145°C, and methyl chloride was added to carry out the reaction. The point at which heat generation ceased was regarded as the end point of the reaction, and the addition of methyl chloride was terminated. The addition time of methyl chloride was 7 hours, the pressure was 0.2MPa, and the amount added was 236.61g (3.21mol per 1mol of aluminum in the AlMg alloy). After the reaction was completed, a mixture of trimethylaluminum (TMAL) and dimethylaluminum chloride (DMAC) was obtained by vacuum distillation, and the aluminum and chlorine contents were quantitatively analyzed. The amounts of TMAL and DMAC in the obtained solution were 60.2g (0.84mol) for TMAL and 16.4g (0.18mol) for DMAC, respectively, and 69.5% of the aluminum contained in the input AlMg alloy was converted to TMAL or DMAC.

[0050] Process (2) (solid-liquid separation) The residue slurry (412.45 g, slurry concentration 37.4 wt%) remaining in the autoclave in step (1) was extracted. This was filtered under reduced pressure (20 kPaA) using a G4 (pore size 5-10 μm) glass filter at room temperature and in a nitrogen atmosphere. The amount of cake obtained was 220.53 g, and the cake was mortar-like and contained 66.27 g of n-dodecane (n-dodecane content approximately 30 wt%). Step (1) and step (2) were repeated for 6 batches to obtain 1,330 g of cake.

[0051] Step (3) (Cake hydrolysis, oil-water separation) 300 g of 7 wt% hydrochloric acid was placed in a 1 L separable flask and heated to 50°C under a nitrogen atmosphere. Then, the cake obtained in step (2) was added at 250 g / h at the same temperature, while 7 wt% hydrochloric acid was supplied at about 1500 g / h. The liquid was transferred from the 1 L separable flask to a 2 L settler at a rate of about 2 L / h using a feed pump, and 380 g of an organic layer was recovered from the settler. The obtained organic layer was analyzed by gas chromatography and mass spectrometry, and was found to be n-dodecane with a purity of 98.8%, and also contained cycloheptadiene and cyclooctadiene.

[0052] Step (4) (Distillation purification of organic layer) The organic layer obtained in step (3) was distilled under reduced pressure to obtain an n-dodecane fraction having a boiling point of 107° C. and 3 kPaA. The amount of n-dodecane recovered was 348.69 g, and the recovery rate was 92%. The obtained n-dodecane was analyzed by gas chromatography to find that its purity was 99.4%, and cycloheptadiene and cyclooctadiene were not detected.

[0053] Step (5) (using a reaction promoter) In a 1.5L autoclave that had been purged with nitrogen, 91.86g of AlMg alloy powder (Al: 38.61g, 1.43mol, Mg: 53.25g, 2.19mol), 11.12g of iodine (0.0306mol per 1mol of aluminum in the AlMg alloy), 5.50g of 2,6-dimethylpyridine (0.0359mol per 1mol of aluminum in the AlMg alloy), 3.36g of dimethylaluminum chloride (DMAC) (0.0254mol per 1mol of aluminum in the AlMg alloy), and 312.80g of distilled n-dodecane obtained in step (4) were added. The temperature was then raised to 145°C, and methyl chloride was added to carry out the reaction. The point at which heat generation ceased was regarded as the end point of the reaction, and the addition of methyl chloride was terminated. The methyl chloride feeding time was 7 hours, the pressure was 0.2 MPa, and the amount fed was 236.30 g (3.29 mol per mol of aluminum in the AlMg alloy). After the reaction was completed, a mixture of trimethylaluminum (TMAL) and dimethylaluminum chloride (DMAC) was obtained by vacuum distillation, and the aluminum and chlorine contents were quantitatively analyzed. The amounts of TMAL and DMAC in the obtained solution were 68.1 g (0.94 mol) and 18.6 g (0.20 mol), respectively, and 79.7% of the aluminum contained in the fed AlMg alloy was converted to TMAL or DMAC. Compared to step (1), the conversion of aluminum to TMAL or DMAC was significantly improved in step (5) using the solvent obtained in step (4). Therefore, the solvent recovered in step (4) is useful as a reaction promoter for TMAL production.

Claims

1. A trialkylaluminum reaction accelerator comprising a process comprising: reacting a trialkylaluminum in an organic solvent, distilling off the trialkylaluminum, recovering a solid content from the remaining slurry, hydrolyzing the solid content to obtain an organic layer, purifying the organic layer, and recovering the organic solvent.

2. 2. The trialkylaluminum reaction product accelerator according to claim 1, wherein the organic solvent is purified from the organic layer by distillation.

3. 3. The trialkylaluminum reaction product accelerator according to claim 1 or 2, wherein the solid content in the slurry is recovered by filtration and / or distillation.

4. 2. The trialkylaluminum reaction product accelerator of claim 1, wherein said solids content comprises said organic solvent in an amount of 1 to 30% by weight.

5. 2. The trialkylaluminum reaction product accelerator according to claim 1, wherein the hydrolysis of the solids is carried out by contact with an aqueous acid solution.

6. The trialkylaluminum reaction product accelerator according to claim 5, wherein the aqueous acid solution is an aqueous hydrochloric acid solution.

7. 7. The trialkylaluminum reaction product accelerator according to claim 6, wherein the aqueous hydrochloric acid solution has a hydrochloric acid concentration of 1 to 36% by weight.

8. 2. The trialkylaluminum reaction product accelerator of claim 1, wherein the organic solvent is a hydrocarbon solvent.

9. The trialkylaluminum reaction product accelerator according to claim 8, wherein the hydrocarbon solvent is at least one selected from the group consisting of saturated hydrocarbon solvents having 5 to 18 carbon atoms and aromatic hydrocarbon solvents having 6 to 12 carbon atoms.

10. The trialkylaluminum reaction product accelerator of claim 9, wherein the hydrocarbon solvent is n-dodecane.

11. 2. The trialkylaluminum reaction accelerator according to claim 1, wherein the reaction of trialkylaluminum is carried out by reacting aluminum and a metal or alloy thereof serving as a reducing agent with an alkyl halide in the organic solvent.

12. 2. The trialkylaluminum reaction accelerator according to claim 1, wherein the reaction of the trialkylaluminum is carried out in the presence of a nitrogen-containing organic compound.

13. The trialkylaluminum reaction product accelerator according to claim 12, wherein the nitrogen-containing organic compound is a conjugated heterocyclic compound containing at least one nitrogen atom and having a five-membered and / or six-membered ring skeleton.

14. The trialkylaluminum reaction product accelerator according to claim 13, wherein the conjugated heterocyclic compound is selected from the group consisting of pyridine, 2-methylpyridine, 4-methylpyridine, 2,6-dimethylpyridine, 2,4,6-trimethylpyridine, 2,6-diethylpyridine, 2,6-diisopropylpyridine, quinoline, isoquinoline, 2,2-bipyridine, and 1-methylimidazole.

15. 2. The trialkylaluminum reaction accelerator according to claim 1, wherein the reaction of the trialkylaluminum is carried out in the presence of a halogen element.

16. The trialkylaluminum reaction product accelerator according to claim 15, wherein the halogen element is iodine.

17. 2. The trialkylaluminum reaction product accelerator of claim 1, wherein said trialkylaluminum is trimethylaluminum.

18. A method for producing trialkylaluminum, comprising using the trialkylaluminum reaction promoter according to claim 1 as a solvent.

19. The method for producing trialkylaluminum according to claim 18, wherein the production of trialkylaluminum is carried out by reacting aluminum and a metal or alloy thereof serving as a reducing agent with an alkyl halide in the trialkylaluminum reaction product promoter used as a solvent.

20. A method for producing a trialkylaluminum reaction product accelerator, comprising: reacting trialkylaluminum in an organic solvent, distilling off the trialkylaluminum, recovering a solid content from the remaining slurry, and purifying an organic layer obtained by hydrolyzing the solid content to recover the organic solvent.

21. The method for producing a trialkylaluminum reaction product accelerator according to claim 20, wherein the organic solvent is purified from the organic layer by distillation.

22. The method for producing a trialkylaluminum reaction product accelerator according to claim 20 or 21, wherein the solid content is recovered from the slurry by filtration and / or distillation.

23. The method for producing a trialkylaluminum reaction product accelerator according to claim 20, wherein the solid content contains 1 to 30% by weight of the organic solvent.

24. The method for producing a trialkylaluminum reaction product accelerator according to claim 20, wherein the hydrolysis of the solid content is carried out by contact with an aqueous acid solution.

25. The method for producing a trialkylaluminum reaction product accelerator according to claim 24, wherein the aqueous acid solution is an aqueous hydrochloric acid solution.

26. The method for producing a trialkylaluminum reaction product accelerator according to claim 25, wherein the hydrochloric acid aqueous solution has a hydrochloric acid concentration of 1 to 36% by weight.

27. The method for producing a trialkylaluminum reaction product accelerator according to claim 20, wherein the organic solvent is a hydrocarbon solvent.

28. The method for producing a trialkylaluminum reaction product accelerator according to claim 27, wherein the hydrocarbon solvent is at least one selected from the group consisting of saturated hydrocarbon solvents having 5 to 18 carbon atoms and aromatic hydrocarbon solvents having 6 to 12 carbon atoms.

29. The method for producing a trialkylaluminum reaction product accelerator according to claim 28, wherein the hydrocarbon solvent is n-dodecane.

30. The method for producing a trialkylaluminum reaction product accelerator according to claim 20, wherein the reaction production of trialkylaluminum is carried out by reacting aluminum and a metal or alloy thereof serving as a reducing agent with an alkyl halide in the organic solvent.

31. The method for producing a trialkylaluminum reaction product accelerator according to claim 20, wherein the trialkylaluminum is trimethylaluminum.