RU2295532C1 - Method for preparing aluminum alkyls - Google Patents

Abstract

FIELD: chemistry of organometallic compounds, chemical technology.

SUBSTANCE: invention relates to the improved method for synthesis of alumino-organic compounds, namely, to aluminum alkyls. Method is realized by interaction of aluminum, hydrogen and olefin, or aluminum, hydrogen, olefin and recirculating aluminum alkyl in organic solvent medium at elevated temperature and pressure. Method involves the preliminary alkylation reaction of aluminum at temperature 80-120°C with feeding 2-20 wt.-% of the measured amount of olefin, and remained amount of olefin is subjected for interaction at temperature 120-200°C. Proposed substances are used widely in different branches of industry, in particular, as components of chelate catalysts used in process for synthesis of synthetic rubbers, polyolefins, higher α-olefins and saturated alcohols and others substances. Invention provides high conversion of aluminum and enhancing activity of aluminum in the process for synthesis of aluminum alkyls.

EFFECT: improved method of synthesis.

3 cl, 2 tbl, 14 ex

Description

The invention relates to the production of organoaluminum compounds, specifically aluminum alkyls, which are widely used in various industries, in particular, as components of metal complex catalysts used in the production of synthetic rubbers, polyolefins, higher α-olefins and fatty alcohols, etc.

Known for the direct synthesis of aluminum trialkyls from activated alkali or alkaline earth metal aluminum, hydrogen and olefin at temperatures of 100-240 ° C and a pressure of 35-240 atm (US Patent No. 3100786, publ. 13.08.63).

The disadvantage of this method is the low conversion of aluminum.

A known method for the simultaneous production of trialkylaluminum and alkylaluminum hydrides by reacting aluminum with olefins and hydrogen in the presence of dialkylaluminum monohalides. Preliminarily, aluminum is activated by trialkylaluminum at a ratio of trialkylaluminum: aluminum equal to 10: 1 (German Application No. 1031792, IPC C 07 F 5/06, publ. 12.06.58).

The high content of trialkylaluminum relative to aluminum in the initial reaction mass leads to an increased content of trialkylaluminum compared to the content of dialkylaluminum in the reaction products.

A known method of producing alkylaluminum compounds (USSR Patent No. 404263, IPC C 08 F 5/06, publ. 26.10.73). The described method consists in the fact that the alloy of aluminum with silicon is reacted with an aluminum-aluminum compound and hydrogen or with hydrogen, an aluminum-aluminum compound and olefin when heated to 50-200 ° C under pressure, preferably 10-300 kg / cm ² . Used olefins contain 2-20 carbon atoms. Mechanical or chemical activation of the initial aluminum alloy is preliminarily carried out. As the activating metal compound, aluminum hydride, sodium hydride, diethyl aluminum chloride, diisobutyl aluminum chloride, triethyl aluminum, triisobutyl aluminum and the like can be used. An aluminum alkyl compound, which may be, for example, triethyl aluminum, hydrogen and an olefin, is fed to the lower or middle part of the reactor filled with an alloy. The metal residue can be extruded through a sieve from the top of the reactor by feeding an aluminum alkyl compound and hydrogen, then it is separated from the organoaluminum compound. The target product is formed due to the interaction of aluminum, olefin and hydrogen in the presence of triethylaluminum, which is the starting substance in this reaction.

The disadvantage of this method is that for the synthesis using the original trialkylaluminum and olefin having the same number of carbon atoms in the chain. To obtain higher trialkylaluminum, for example, with the number of carbon atoms C ₅ -C ₂₀ , it is first necessary to synthesize the starting higher trialkylaluminum, which requires an increased consumption of the starting components.

A known method of producing higher aluminum alkyl by the interaction of aluminum, hydrogen and ethylene (AS USSR No. 237891, IPC C 07 F 5/06, publ. 17.12.69). The process is carried out in one stage at a temperature of 50-150 ° C and a gas mixture pressure of 1 to 100 atm using aluminum in the form of a powder with a developed micropore network doped with transition metal additives.

The disadvantage of the described method is the inability to obtain an individual organoaluminum compounds.

Closest to the proposed method is the production of aluminum alkyl by a batch or continuous method by reacting aluminum powder, recirculating aluminum alkyl, hydrogen and olefin in a hydrocarbon solvent, for example gasoline, heptane or toluene, at a temperature of 100-140 ° C and a pressure of 2-5 MPa (N .N. Lebedev “Chemistry and technology of basic organic and petrochemical synthesis”, 4th ed., Moscow: Chemistry, 1988, pp. 297-299).

The disadvantages of this method are the high content of trialkylaluminum in the reaction product, which negatively affects the activity and stability of the obtained component of the catalytic system used in the polymerization of conjugated dienes, as well as the low conversion of aluminum metal, which leads to its increased consumption and low yield of the target product in the process of one synthesis cycle.

The objective of the invention is to achieve a high conversion of aluminum and increase the activity of aluminum in the synthesis of aluminum alkyl.

The problem is solved by the method of producing aluminum alkyls, including the interaction of aluminum, hydrogen and olefin or aluminum, hydrogen, olefin and recycled aluminum alkyl in an organic solvent at elevated temperature and pressure, while the aluminum alkylation reaction is preliminarily carried out at a temperature of 80-120 ° C with a supply of 2- 20 wt.% Of the calculated amount of olefin, and the remaining amount of olefin is subjected to interaction at a temperature of 120-200 ° C.

After supplying 2-20 wt.% Of the calculated amount of olefin, it is possible to withstand the reaction mass for 0.5-3.0 hours, possibly in the absence of hydrogen.

As an organic solvent in the production of aluminum alkyls, it is possible to use, for example, a hexane-containing solvent that meets the requirements of normative and technical documentation TU 0251-120-05766801-2003 “Hexane solvents” or TU 38.1011228-90 “Hexane solvents (nefras)”, or GOST 8505- 80 "Nefras-S 50/170" or any other hexane-containing solvent.

The difference of the invention is the preliminary aluminum alkylation reaction at a temperature of 80-120 ° C with a feed of 2-20 wt.% Of the calculated amount of olefin and the interaction of the remaining amount of olefin at a temperature of 120-200 ° C, the use of a hexane solvent in the synthesis of aluminum alkyls and also the exposure of the reaction mass for 0.5-3.0 hours after feeding 2-20 wt.% of the calculated amount of olefin.

The proposed method for producing aluminum alkyl is as follows.

A suspension of aluminum powder in an organic solvent and, possibly, a solution of recycle aluminum alkyl or a suspension of aluminum powder in a solution of recycle aluminum alkyl, hydrogen and 2-20 wt.% Are fed into a reactor equipped with a stirrer and a thermostatic jacket, previously free of oxygen and moisture and purged with nitrogen. from the total estimated amount of olefin containing, for example, from 4 to 6 carbon atoms. The reaction mass is maintained with constant stirring at a temperature of 80-120 ° C for 0.5-3.0 hours, after which the remaining amount of olefin is fed into the reactor, the reaction mass is kept at a temperature of 120-200 ° C. At the end of the synthesis, the obtained aluminum alkyls are incubated for 0.2-4.0 hours. The pressure in the reactor throughout the process withstand 0.25-6.5 MPa. At the end of the process, the reactor is cooled and the excess olefin and hydrogen are blown away. The resulting aluminum alkyl is discharged from the reactor.

The implementation of the proposed method for producing aluminum alkyls is illustrated by the following examples.

Example 1

In a steel reactor with a volume of 0.5 l, equipped with a mixing device in the form of a stirrer and a thermostatic jacket, previously freed from oxygen and moisture and purged with nitrogen, 24.5 g of aluminum powder of the ASDT grade corresponding to the requirements of the normative and technical documentation TU 1791 are loaded in the form of a suspension -99-019-98, in 22 ml of Nefras solvent that meets the requirements of normative and technical documentation TU 38.1011228-90, and 42.5 g of a 48.9% recycle solution of diisobutylaluminium hydride in Nefras solvent. The mixer is turned on, the temperature in the reactor is raised to 80 ° C and 3.4 g of hydrogen and 17.5 g of isobutylene are fed, which is 17.24 wt.% Of the total calculated amount. The reaction mass is kept for 3 hours at a temperature of 80 ° C, after which the temperature is raised to 120 ° C and 84 g of isobutylene are fed into the reactor. At the end of the synthesis, the reaction mass is kept for 2 hours, after which the reaction mass is cooled by supplying refrigerant to the reactor jacket, the resulting product, which contains mainly diisobutylaluminum hydride (DIBAG) and triisobutylaluminum (TIBA), is discharged from the reactor.

The conditions of the process and the results of the experiment are shown in table 1.

Example 2

The method of producing aluminum alkyls is also carried out as described in example 1, but 3.0 g of hydrogen and 20.2 g of isobutylene, which is 19.86 wt.% Of the calculated amount, are preliminarily fed into the reactor and the reaction mass is maintained at a temperature of 100 ° C. for 1 hour, after which the temperature is raised to 150 ° C and 81.5 g of isobutylene are fed. At the end of the synthesis, the reaction mass was incubated for 2.5 hours. The resulting product, containing mainly DIBAG and TIBA, after cooling, is discharged from the reactor.

The conditions of the process and the results of the experiment are shown in table 1.

Example 3

The method of producing aluminum alkyls is carried out in the same manner as described in example 1, but 3.0 g of hydrogen and 10 g of isobutylene, which is 9.95 wt.% Of the calculated amount, are preliminarily fed into the reactor and the reaction mass is maintained at a temperature of 120 ° C. for 0.5 hours, after which the temperature is raised to 200 ° C and serves 90.5 g of isobutylene. At the end of the synthesis, the reaction mass was incubated for 2.5 hours. The resulting product, containing mainly DIBAG and TIBA, after cooling, is discharged from the reactor.

The conditions of the process and the results of the experiment are shown in table 1.

Example 4

The method of producing aluminum alkyl is carried out in the same manner as described in example 1. 28 g of aluminum powder of the ASDT grade in 50 ml of Nefras solvent are fed into the reactor in suspension. The mixer is turned on, the temperature in the reactor is raised to 110 ° C and 3.4 g of hydrogen and 25 g of 2-methyl-1-pentene are fed, which is 16.45 wt.% Of the total calculated amount. The reaction mass is kept for 2 hours at a temperature of 110 ° C, after which the temperature is raised to 160 ° C and 127 g of 2-methyl-1-pentene are fed into the reactor. At the end of the synthesis, the reaction mass is kept for 3 hours, after which the reaction mass is cooled, the resulting product, containing mainly di-2-methylpentylaluminium hydride and tri-2-methylpentylaluminum, is discharged from the reactor.

The conditions of the process and the results of the experiment are shown in table 1.

Example 5

The method of producing aluminum alkyls is carried out in the same manner as described in example 1. 20 g of ASDT grade aluminum powder in a suspension of 30 ml of Nefras solvent and 25 g of a 60% recycled solution of triethyl aluminum, 5.0 g of hydrogen and 10 are fed into the reactor g of ethylene, which is 20 wt.% of the total calculated amount. The reaction mass is kept at a temperature of 80 ° C for 1 hour, after which the temperature is raised to 140 ° C, 40 g of ethylene are fed. At the end of the synthesis, the reaction mass is maintained for 2 hours, after which the reaction mass is cooled, the resulting product, which contains mainly triethylaluminum and diethylaluminum hydride, is discharged from the reactor.

The conditions of the process and the results of the experiment are shown in table 1.

Example 6

The method of producing aluminum alkyls is carried out in the same manner as described in Example 1. 23 g of aluminum powder of the ASDT grade in a suspension of 20 ml of Nefras solvent and 8.8 g of a 60% recycle solution of diisobutylaluminium hydride, 3.2 g of hydrogen are fed into the reactor and 1.9 g of isobutylene, which is 2 wt.% of the total calculated amount. The reaction mass is kept at a temperature of 100 ° C for 1.5 hours, after which the temperature is raised to 150 ° C, 93 g of isobutylene are fed. At the end of the synthesis, the reaction mass is maintained for 1.5 hours, after which the reaction mass is cooled, and the resulting product, containing mainly DIBAG and TIBA, is discharged from the reactor.

The conditions of the process and the results of the experiment are shown in table 1.

Example 7

In a steel reactor with a volume of 0.5 l, equipped with a mixing device in the form of a stirrer and a thermostatic jacket, previously freed from oxygen and moisture and purged with nitrogen, 32.5 g of aluminum powder of the ASDT grade, corresponding to the requirements of the normative and technical documentation TU 1791, are loaded in the form of a suspension -99-019-98, in 60 ml of Nefras solvent, which meets the requirements of normative and technical documentation TU 38.1011228-90, and 4.5 g of hydrogen. The mixer is turned on, the temperature in the reactor is raised to 110 ° C, and 27.4 g of isobutylene is fed, which is 20 wt.% Of the total calculated amount. The reaction mass is kept for 3 hours at a temperature of 110 ° C, after which the temperature is raised to 170 ° C and 110 g of isobutylene are fed into the reactor. At the end of the synthesis, the reaction mass is kept for 2 hours, after which the reaction mass is cooled by supplying refrigerant to the reactor jacket, the resulting product, which contains mainly diisobutylaluminum hydride (DIBAG) and triisobutylaluminum (TIBA), is discharged from the reactor.

The conditions of the process and the results of the experiment are shown in table 1.

Example 8

The method of producing aluminum alkyls is carried out in the same manner as described in example 7, but 21.9 g of isobutylene, which is 16.0 wt.% Of the calculated amount, are preliminarily fed into the reactor and the reaction mass is maintained at a temperature of 115 ° C for 2.5 hours, after which the temperature is raised to 180 ° C and 115.1 g of isobutylene are fed. At the end of the synthesis, the reaction mass was incubated for 2.5 hours. The resulting product, containing mainly DIBAG and TIBA, after cooling, is discharged from the reactor.

The conditions of the process and the results of the experiment are shown in table 1.

Example 9

Under industrial conditions, a suspension of aluminum powder of the ASDT grade containing 90 kg of aluminum and 88 kg of Nefras solvent is fed into a 2 m ³ mixer. 145 kg of a 60% DIBAG solution, 2 kg of hydrogen (up to a pressure of 1.5 MPa) are pushed into the reactor and 80 kg of isobutylene is fed, which is 19.66 wt.% Of the total calculated amount. The reaction mass at a temperature of 90 ° C is maintained with stirring for 2 hours. Then the temperature in the reactor is increased to 150 ° C and 327 kg of isobutylene and 12 kg of hydrogen are metered in for 2.5 hours with constant stirring. At the end of the synthesis, the reaction mass is maintained for 1 hour, after which it is cooled to 80 ° C. Excessive amounts of isobutylene and hydrogen are blown through an oil separator. After cooling, the resulting product, containing mainly DIBAG and TIBA, is discharged from the reactor.

The conditions of the process and the results of the experiment are shown in table 1.

Examples 10 and 11

The method of producing aluminum alkyl is carried out as described in example 7. At a temperature of 80 ° C and 110 ° C, 41 kg and 60 kg of isobutylene are supplied, which is 10.07 wt.% And 14.74 wt.%, Respectively. Under such conditions, the reaction mass is kept under stirring for 2 and 3 hours, hydrogen is supplied to a pressure of 1.5 MPa and the temperature is increased to 140 ° C and 160 ° C, respectively. Then, with stirring, 366 kg and 347 kg of isobutylene, 13.6 kg and 15 kg of hydrogen are dosed. At the end of the synthesis, the reaction mass is maintained with a working stirrer for another 1-4 hours. The contents of the reactor are cooled down to 70-80 ° C, and excess amounts of isobutylene and hydrogen are blown off through an oil separator. After cooling, the resulting product, containing mainly DIBAG and TIBA, is discharged from the reactor.

The conditions of the process and the results of the experiment are shown in table 1.

Example 12

24.3 g of a 5% hexane solution of neodymium neodecanoate (NN) (1.85 mmol), 18.2 g of DIBAG solution (16.7 mmol) obtained in Example 2 and introduced into a flask, dried and nitrogen-purged at room temperature, are introduced diluted to 13 wt.% (according to DIBAG), and 0.63 g of piperylene (9.25 mmol), add 33 g of a 10% hexane solution of TIBA (16.7 mmol) and 2 g of a 15% hexane solution of ethyl aluminum sesquichloride (EASC) (2.4 mmol).

1470 g of Nefras solvent, 200 g of butadiene are charged into a 5 liter autoclave and mixed. At a temperature of 35 ° C, 15.6 g of a solution of a catalytic complex containing 0.37 mmol of neodymium neodecanoate is introduced into the autoclave. The polymerization of butadiene is carried out at a temperature of 60 ° C for 1 hour. The obtained polymerizate is stabilized and isolated by aqueous degassing, dried in an oven at a temperature of 60-70 ° C in a nitrogen atmosphere. Monomer conversion is 98%.

The resulting rubber is analyzed for microstructure, molecular weight distribution (MMP), gel content and physical and mechanical tests of the rubber compound. The data obtained are shown in table 2.

Example 13

According to example 12, in the preparation of the catalytic complex, a DIBAG solution diluted to 11.5 wt.% Obtained according to example 9 is used.

A solution of the catalytic complex is introduced into an autoclave containing 1670 g of a mixture obtained by mixing 1470 g of Nefras solvent and 200 g of butadiene at a temperature of 35 ° C. The polymerization is carried out at a temperature of 60 ° C, the polymerizate is stabilized, isolated by aqueous degassing and dried.

The data obtained are shown in table 2.

Example 14

According to example 12, 24.3 g of a 5% hexane solution of neodymium neodecanoate (1.85 mmol), 15.8 g of DIBAG solution (16.7 mmol) obtained in example 3 and diluted to 15 wt are introduced into the flask at room temperature. % (according to DIBAG), and 0.63 g of piperylene (9.25 mmol) add 19 g of a 10% hexane solution of triethyl aluminum (16.7 mmol) obtained in example 5, and 2 g of 15% hexane EAAC solution (2.4 mmol).

The polymerization of butadiene is carried out. A 12% solution of butadiene in the Nefras solvent and a catalytic complex containing 0.37 mmol of neodymium neodecanoate are introduced into the autoclave.

The data obtained are shown in table 2.

As can be seen from the above examples, the proposed method allows to achieve high conversion of aluminum and increase the activity of aluminum in the synthesis of aluminum alkyl.

Table 1 Indicator Examples one 2 3 four 5 6 7 8 9 10 eleven Preliminary aluminum alkylation reaction Temperature ° C 80 one hundred 120 110 80 one hundred 110 115 90 80 110 Holding time, hour 3 one 0.5 2 one 1,5 3.0 2,5 2 2 3 The olefin consumption, wt.% 17.24 19.86 9.95 16.45 20,0 2.0 20,0 16,0 19.66 10.07 14.74 The completion of the aluminum alkylation reaction Temperature ° C 120 150 200 160 140 150 170 180 150 140 160 Experience Results The conversion of aluminum,% 93.0 91.6 94.3 79.8 90,4 92.8 82.3 84.1 86.4 85,2 93.5 Mass fraction of active aluminum,% 15.0 14.9 15.0 10.8 17.8 16,4 14.5 14.7 14.5 14,4 14.8 Alkylaluminium hydride, wt.% 76.9 77.1 78.0 72.9 1,6 84.0 74.1 75.3 75.1 73.7 76.8 Alkyl aluminum, wt.% 2,4 2.1 1,6 4.1 73,2 3.3 3,5 2.6 2,3 3,5 1.7

table 2 Indicator Example 12 Example 13 Example 14 Monomer Conversion,% 98 one hundred one hundred Mooney viscosity, ML 1 + 4 (100 ° C) 45 46 46 The content of 1,4-cis units,% 98 98 98.5 The content of the gel fraction, wt.% 0.05 0.04 0.02 Molecular weight distribution Mn 10 ^-3 175 166 165 Mw 10 ^-3 429 425 411 Mz 10 ^-3 921 928 855 Polydispersity 2,4 2.6 2,5 Physico-mechanical properties of the rubber compound Elongation stress 300%, MPa 10.1 9.8 10.3 Tensile strength, MPa 22.5 21.9 22.2 Elongation at break,% 510 526 500

Claims (3)

1. A method of producing aluminum alkyls by reacting aluminum, hydrogen and an olefin or aluminum, hydrogen, olefin and recycled aluminum alkyl in an organic solvent at elevated temperature and pressure, characterized in that the aluminum alkylation reaction is preliminarily carried out at a temperature of 80-120 ° C. with a feed of 2- 20 wt.% Of the calculated amount of olefin, and the remaining amount of olefin is subjected to interaction at a temperature of 120-200 ° C. 2. The method of producing aluminum alkyl according to claim 1, characterized in that after feeding 2-20 wt.% Of the calculated amount of olefin, the reaction mass is kept for 0.5-3.0 hours 3. The method of producing aluminum alkyl according to claim 1, characterized in that a hexane-containing solvent is used as an organic solvent.