RU2131889C1 - Polyisobutylene production process - Google Patents

Abstract

FIELD: polymer production. SUBSTANCE: polyisobutylene production process via polymerization of isobutylene in hydrocarbon solvent in presence of preliminarily prepared catalyst containing Lewis acid and organoaluminum compound is distinguished by that preliminarily prepared catalyst additionally contains isobutylene and represents complex prepared by interaction of Lewis acid, organoaluminum compound, and isobutylene at molar ratio 1:0.1: 0.01. Organoaluminum compound is selected from the group including: interaction products of equimolar amounts of trialkylaluminum and alkanolamine of formula

, wherein R is ethyl or isobutyl, R' and R" are hydrogen, ethyl, isobutyl, group

, or polyaluminooxane with general formula

Description

 The invention relates to the field of technology of synthetic polymeric materials, in particular to a method for producing polyisobutylene, and may find application in the petrochemical industry.

 Known methods for producing low molecular weight polyisobutylene by polymerization of isobutylene in the presence of Lewis acid and organoaluminum compounds as modifiers [1] (Belgian patent N 538782, Montecatini, prior. 08.06.54), [2] (Belgian patent N 546846, Hercules Powder company, date of grant of the patent 07.04.56).

 Closest to the proposed method is a laboratory method for producing low molecular weight polyisobutylene in the presence of a preformed complex of titanium tetrachloride with triethyl aluminum [3] [prototype] (A. V. Topchiev, B. A. Krenzel et al. "Polymerization of isobutylene in the presence of triethyl aluminum and titanium tetrachloride "- Reports of the Academy of Sciences of the USSR, vol. III, N 1, 1956, p. 121-124).

 The disadvantage of these processes is the presence of an induction period reaching 40-60 minutes. To eliminate it, the dosage of the catalyst is usually increased, which complicates the maintenance of a stable temperature regime of polymerization, contributes to an increase in ash in the polymer and a decrease in its quality.

The selection of the polymer is carried out traditionally in three stages:
1) stopping the polymerization reaction, meaning catalyst deactivation by introducing special reagents into the reaction zone,
2) water-alkaline washing of the polymerizate from catalyst residues,
3) degassing or removal of residual water, monomer and solvent from the polymer, which means drying.

где R= этил, изобутил, R',R''=-Н, этил, изобутил,

полиалюмоксан общей формулы:

где n = 0-30, R, R', R'' = -H, этил, изобутил,
диалкилалюминийгидрид общей формулы

где R = этил, изобутил,
триалкилалюминий (Г), или смесь полиалюмоксана общей формулы (Б) с диалкилалюминийгидридом общей формулы ((В) или смесь полиалюмоксана (Б) с триалкилалюминием.The aim of the invention is to increase the activity of the catalyst by introducing isobutylene in the preliminary formation of a complex based on Lewis acid and an organoaluminum compound selected from the group:
the product of the interaction of equimolar amounts of trialkylaluminum with alkanolamine of the General formula

where R = ethyl, isobutyl, R ', R''= - H, ethyl, isobutyl,

polyalumoxane of the general formula:

where n = 0-30, R, R ', R''= -H, ethyl, isobutyl,
dialkylaluminum hydride of the general formula

where R = ethyl, isobutyl,
trialkylaluminum (G), or a mixture of polyaluminoxane of general formula (B) with dialkylaluminum hydride of general formula ((C) or a mixture of polyaluminoxane (B) with trialkylaluminum.

 The components of the catalyst: Lewis acid, modifier, isobutylene are mixed at a certain temperature in a molar ratio of the components of the Lewis acid: organoaluminum compound: isobutylene from 1: 0.1: 0.01 to 1: 3: 50, respectively. The complex is maintained at the same temperature for a certain time and fed to the polymerization.

 In this case, the polymerization process proceeds without an induction period. The polymerization time is reduced, the catalyst consumption is reduced, and the ash content in the polymerizate is accordingly reduced.

 The conditions for the preparation of complexes and the polymerization process are reflected in the examples and tables. As a Lewis acid, it is proposed to use either titanium tetrachloride or boron trifluoride.

Use as a stopping agent of a compound selected from the group:
Catamine "AB" -50% aqueous solution of alkyldimethylbenzylammonium chloride (TU 24-012-1316 44 01-94),
sodium methylsiliconate, sodium ethylsiliconate, tetrahydrofurfuryl alcohol, tetraethoxysilane can not only effectively interrupt the polymerization process, but also complex the catalyst residues, which are then filtered off. Thus, the ash content in the finished product does not exceed 0.0001% of the mass.

Example 1 (prototype) [3]
In a reaction vessel, which is a four-necked flask with a stirrer and bubbler, equipped with a reflux condenser and a thermometer, 18 ml (16 mol / t of isobutylene or 0.3% by weight of isobutylene) of a toluene solution of triethyl aluminum are poured.

The reactor is placed in a cooling mixture and, when the temperature in the reactor reaches 0 - +5 ^o C, 200 ml or 140 g of isobutylene is passed through. The polymerization temperature is maintained in the range +35 - +37 ^o C. The test time is 120 minutes.

 At the end of the experiment, 0.5 ml of ethanol is added to the reaction mass to decompose the catalyst. Then the polymerizate is transferred to a separatory funnel, where it is washed with a 10% soda solution, and then with water from the catalyst residues.

The reaction product is dried over calcined CaCl ₂ , the solvent with the remaining water is distilled off in a rotary film evaporator (T = 80 ^o C, vacuum 2 - 3 mm RT. Art.). The polymer yield is 60% of the mass. The polymer is characterized by a viscosity molecular weight of 2000, Mw = 17360, Mn = 2860, Mw / Mn = 6.07, flash point 98 ^o C.

 The ash content of 0.02% wt., The polymer is colorless, transparent.

 Example 2

The experiment is carried out according to example 1, the difference is that complex (1) prepared as follows is used as a catalyst: the reaction vessel is cooled to a temperature of minus 78 ^o C and 11 ml of titanium tetrachloride (10 mol / t) are fed into it in a stream of nitrogen isobutylene), then 4.1 ml of triethyl aluminum (10 mol / t of isobutylene) and 5 ml of toluene solution of isobutylene (1 mol / t of isobutylene). The molar ratio of TiCl ₄ : triethylaluminum: isobutylene = 1: 1: 0.1. Maintain the complex at minus 78 ^o C for 60 minutes.

The complex is then placed in a warm polymerization reactor with a stirrer and reflux condenser and isobutylene vapors are passed through it, maintaining the polymerization temperature +35 - +37 ^o C. The test time is 60 minutes. The output of polyisobutylene 100% of the mass.

At the end of the polymerization, 2 ml of tetrahydrofurfuryl alcohol in a molar ratio TiCl ₄ : alcohol = 1: 4 is introduced into the reactor as a stopper.

 The polymerizate is intensively mixed, filtered through belting and degassed.

 The viscosity molecular weight of the polymer is 2400, the polymer is colorless, transparent, no ash.

и с 2,9 мл раствора изобутилена (0,6 мол/т изобутилена). Мольное соотношение при этом TiCl₄ : (А) : изобутилен = 1 : 1 : 0,1. Время выдержки 60 минут.Example 3
It differs from example 1 in that complex (2) prepared as follows is used as a catalyst: 6.5 ml of a titanium tetrachloride solution (6 mol / t of isobutylene), mixed at minus 30 ^o C with 2.4 ml of alkanolamine solution (6 mol / t isobutylene) of the formula

and with 2.9 ml of isobutylene solution (0.6 mol / t of isobutylene). The molar ratio in this case is TiCl ₄ : (A): isobutylene = 1: 1: 0.1. The exposure time is 60 minutes.

The difference also lies in the fact that the polymerization is carried out in a metal reactor with a stirrer and a cooling jacket as follows:
at minus 30 ^° C, 200 ml of isobutylene (125 g) are fed into the reactor. Serve the entire cooked complex. By cooling, maintain the polymerization temperature minus 20 ^o C.

 After 10 minutes, the polymer yield is 95% wt. For stoppering, the compound Catamine AB is introduced (TU 24-012013164401-94) in an amount of 1 ml. Catamine is a 50% aqueous solution of pentyldimethylbenzylammonium chloride.

 After vigorous stirring, the polymer is separated from the resulting complex by filtration.

 After degassing, polyisobutylene is characterized by a viscous molecular weight of 25,000. No ash.

и 193 мл раствора изобутилена (40 мол/т изобутилена). Мольное соотношение TiCl₄ : Б : изобутилен = 1 : 1 : 10. Комплекс выдерживают при минус 30^oC 20 минут. Комплекс подают в реакционную зону таким образом, чтобы поддерживать температуру полимеризации в интервале минус 15^o - минус 20^oC. Время полимеризации 3 минуты. Обрыв полимеризации проводят введением 5 мл метилсиликоната натрия.Example 4
Differs from example 3 in that the polymerization of isobutylene is carried out in 1 liter of a 15% solution in toluene. Amount of isobutylene 200 ml (125 g). The difference also lies in the fact that a toluene solution of complex (3) is used as a catalyst, prepared as follows: in a reactor at minus 30 ^o C, 4.4 ml of a solution of titanium tetrachloride (4 mol / t of isobutylene), 3 ml of a polyaluminoxane solution ( 4 mol / t isobutylene) of the following formula:

and 193 ml of isobutylene solution (40 mol / t of isobutylene). The molar ratio of TiCl ₄ : B: isobutylene = 1: 1: 10. The complex is maintained at minus 30 ^o C for 20 minutes. The complex is fed into the reaction zone in such a way as to maintain the polymerization temperature in the range of minus 15 ^o - minus 20 ^o C. The polymerization time is 3 minutes. The polymerization is terminated by introducing 5 ml of sodium methylsiliconate.

 After filtering the polymerizate through a layer of white soot, it is degassed from the residues of monomer and toluene.

 The output of polyisobutylene is 89% of the mass. The molecular weight of the polymer is 15700. There is no ash, the polymer is transparent and colorless.

 Example 5

и 64 мл раствора изобутилена в гексане (12 мол/т изобутилена). Мольное соотношение TiCl₄ : Б : изобутилен = 1 : 0,1 : 3. Время выдержки 1 минута.The isobutylene polymerization is carried out according to example 3, but complex (4) prepared as follows is used as a catalyst: 5 ml of a solution of titanium tetrachloride in hexane (4 mol / t of isobutylene), 5 ml of a solution of polyaluminoxane in hexane are mixed (0.4 mol / t of isobutylene) of the following formula:

and 64 ml of a solution of isobutylene in hexane (12 mol / t of isobutylene). The molar ratio of TiCl ₄ : B: isobutylene = 1: 0.1: 3. The exposure time is 1 minute.

The polymerization is carried out at minus 10 ^o C for 1 minute. To stop the polymerization, 1 ml of sodium ethylsiliconate was added to the reaction mixture.

After filtration and degassing, a yield of polyisobutylene of 90%, a molecular weight of 20,000, an ash content of 0.0001% by mass. (1 ppm)
Example 6

The isobutylene polymerization is carried out according to example 4, the difference is that the butane-butene fraction of the following composition (% wt.) Is used for polymerization: iso-C ₄ H ₁₀ 60 - 63; iso-C ₄ H ₈ 15-22; nC ₃ H ₈ 0.5 - 0.7; α-C ₄ H ₈ 15 - 5; cis-β-C ₄ H ₈ 0.01 - 1.3; tr-β-C ₄ H ₈ 0.3 - 6.

1 мл диизобутилалюминийгидрида (0,3 мол/т изобутилена) и 0,15 мл раствора изобутилена (0,03 мол/т изобутилена). Мольное соотношение TiCl₄ : Б : изобутилен = 1 : 3 : 0,01. Выдерживают комплекс в течение 4 суток при минус 30^oC и весь подают на полимеризацию.1000 ml of the fraction are charged into a reactor cooled to minus 30 ^° C and complex (5) is prepared, prepared as follows:
at a temperature of minus 30 ^o C mix 3.03 ml of a toluene solution of titanium tetrachloride (3 mol / t of isobutylene), 6.75 ml of a solution of polyaluminoxane (9 mol / t of isobutylene) of the following formula:

1 ml of diisobutylaluminium hydride (0.3 mol / t of isobutylene) and 0.15 ml of isobutylene solution (0.03 mol / t of isobutylene). The molar ratio of TiCl ₄ : B: isobutylene = 1: 3: 0.01. Maintain the complex for 4 days at minus 30 ^o C and all served for polymerization.

The polymerization is carried out at 0 ^o C for 3 minutes. For stopping, 2 ml of tetraethoxysilane are introduced into the polymerizate. After filtration and degassing, the yield is 90% of the mass. Viscosity molecular weight 5000. No ash.

 Example 7

The polymerization is carried out as in example 2, but the isobutylene vapor is passed through complex (6), prepared as follows: at a temperature of minus 30 ^o C through 40 ml of a solution of polyaluminoxane (n = 0) in toluene (3 mol / t of isobutylene) containing isobutylene (in amount of 0.03 mol / t of isobutylene), boron trifluoride in an amount of 3 mol / t of isobutylene is passed. The molar ratio of BF ₃ : B: isobutylene = 1: 1: 0.01. The exposure time is 10 minutes.

200 ml of isobutylene are passed through the complex at a temperature of +35 ^o C. The polymerization time is 3 minutes. The cliff spend 1 ml of catamine "AB" TU 24-012-13164401-94.

 After filtration and degassing, the polymer yield is 98% of the mass. Viscosity molecular weight 3500. Ash content of 0.0001% of the mass. (1 ppm).

 Example 8

The polymerization is carried out according to example 4. The difference is that the complex used is the catalyst (7), obtained as follows: at a temperature of 0 ^o C through a toluene solution containing polyaluminoxane (n = 30) in an amount of 3 mol / t of isobutylene, triisobutylaluminum in an amount of 0.3 mol / t of isobutylene, isobutylene in an amount of 150 mol / t of isobutylene, boron trifluoride in an amount of 3 mol / t of isobutylene is passed. The complex is kept for 5 minutes and fed to the polymerization of isobutylene in a metal reactor. The polymerization temperature +15 ^o C. After 5 minutes, the process break off 1 ml of sodium methylsiliconate.

 After filtration and drying, a yield of polyisobutylene of 98% by weight with a viscous molecular weight of 24,500 is obtained. Ash content of 0.0001% by weight. (1 ppm).

 Example 9

The polymerization is carried out as in example 6. The difference is that complex (8) is used as a catalyst, which is prepared as follows: at a temperature of minus 10 ^o C through a hexane solution containing polyaluminoxane (n = 10) in an amount of 1 mol / t of isobutylene , diethylaluminum hydride in an amount of 0.1 mol / t of isobutylene, isobutylene in an amount of 1 mol / t of isobutylene, boron trifluoride in an amount of 0.5 mol / t of isobutylene is passed. The molar ratio of BF ₃ : B: C: isobutylene = 1: 2: 0.2: 2.

The complex is incubated for 30 minutes and fed to the polymerization of isobutylene from the butane-butylene fraction. The polymerization temperature is -10 ^° C. The polymerization time is 30 seconds. For stopping, 1 ml of tetraethoxysilane is introduced into the polymerizate. After filtration and degassing, polyisobutylene is obtained with a yield of 100% of the mass. and a viscosity molecular weight of 25,000.

 The ash content of 0.0001% of the mass. (1 ppm).

 Example 10

The polymerization of isobutylene is carried out according to example 4, the difference is that hexane is used instead of toluene. The difference also lies in the fact that the catalytic complex (9) is prepared in a hexane solution as follows: at minus 25 ^o C through a solution containing polyaluminoxane (n = 4) in an amount of 0.3 mol / t of isobutylene, isobutylene in an amount of 5 mol / t of isobutylene, boron trifluoride is passed in an amount of 0.1 mol / t of isobutylene. The molar ratio of BF ₃ : B: isobutylene = 1: 3: 50. The complex is incubated for 10 minutes and the whole is fed for polymerization. The polymerization temperature is maintained at -50 ^° C. The polymerization time is 4 seconds. To terminate, 3 ml of sodium ethylsiliconate are introduced into the polymerizate.

After filtration and drying, polyisobutylene is obtained with a yield of 98% of the mass. and a viscous molecular weight of 10,000. No ash,
Example 11

The polymerization of isobutylene is carried out according to example 4, but as the catalyst used complex (10), prepared as follows:
at a temperature of minus 10 ^o C in the reaction vessel mix 4.4 ml of a solution of titanium tetrachloride in toluene (4 mol / t of isobutylene), 5 ml of a solution of diisobutylaluminum hydride (0.4 mol / t of isobutylene). The molar ratio of TiCl ₄ : B: isobutylene = 1: 1: 10. The complex is maintained at minus 10 ^o C for 20 minutes.

The complex is fed into the reaction zone so as to maintain the polymerization temperature minus 5 ^° C. The polymerization time is 10 minutes. The output of polyisobutylene is 90% of the mass.

 Interruption of polymerization (stoppering) is carried out by introducing 5 ml of sodium methylsiliconate.

 After filtering the polymerizate through a layer of white soot, it is degassed from residues of isobutylene and toluene.

 The molecular weight of polyisobutylene is 10000. No ash. The polymer is transparent and colorless.

 Thus, the use of preformed complexes based on Lewis acids, organoaluminum compounds and isobutylene allows the polymerization of isobutylene with a reduced catalyst consumption. The use of special stoppers for complexing the catalyst and subsequent filtration of the polymerizate makes it possible to anesthetize polyisobutylene to an ash content of 0.0001% wt. (1 ppm).

Literature
1. Belgian patent N 538782, firm Montecatini, prior. 06/08/54
2. Belgian patent N 546846, the company Hercules Powder company, the date of issue of the patent 07.04.56.

 3. A.V. Topchiev, B.A. Krenzel et al. "Polymerization of isobutylene in the presence of triethylaluminum and titanium tetrachloride", Reports of the USSR Academy of Sciences, vol. III, N 1, 1956, p. 121-124.

Claims (3)

1. The method of producing polyisobutylene by polymerization of isobutylene in a hydrocarbon solvent in the presence of a preformed catalyst from Lewis acid and an organoaluminum compound followed by isolation of the polymer, characterized in that the preformed catalyst further comprises isobutylene and is a complex obtained by reacting at a molar ratio of the components of the catalytic complex Lewis acid: organoaluminum compound: isobutylene from 1: 0.1: 0.0 1 to 1: 3: 50, respectively, wherein the organoaluminum compound is selected from the group consisting of the reaction product of equimolar amounts of trialkylaluminum with alkanolamine of general formula A

where R is ethyl, isobutyl;
R ', R''- H, ethyl, isobutyl,

or polyalumoxane general formula B

where n = 0 - 30;
R, R ′, R ″ —H, ethyl, isobutyl;
or dialkylaluminum hydride of the general formula B

where R is ethyl, isobutyl;
or trialkylaluminum (D); or a mixture of polyaluminoxane of general formula B with dialkylaluminium hydride of general formula B; or a mixture of polyaluminoxane (B) with trialkylaluminium (D), wherein the subsequent isolation of the polymer includes stoppering the polymerization with substances selected from the group: alkyl dimethylbenzylammonium chloride, sodium methylsiliconate, sodium ethylsiliconate, tetrahydrofurfuryl alcohol, tetraethoxysilane polymerization, followed by polymerization, followed by polymerization of the polymer, followed by degumming, and .  2. The method according to claim 1, characterized in that either titanium tetrachloride or boron trifluoride is used as the Lewis acid.  3. The method according to claim 1, characterized in that the polymerization of isobutylene is carried out in bulk or in the medium of butane-butylene fraction.

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