RU2432365C1 - Method of producing catalyst for (co) - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: described is a method of producing a catalyst for (co)polymerisation of butadiene by reacting components comprising triazobutylaluminium, conjugated diene and a rare-earth element compound, holding the reaction mass, followed by addition of diisobutylaluminium hydride and alkylaluminium chloride. The alkylaluminium chloride is added in a mixture with triisobutylaluminium in molar ratio 1:1. The process is carried out in molar ratio triisobutylaluminium: conjugated diene: rare-earth element compound: diisobutylaluminium hydride: alkylaluminium chloride (in terms of Cl) equal to 6-12:1-20:1:6-12:1.5-1.7.

EFFECT: method enables synthesis of a highly-efficient catalyst for polymerisation of butadiene in order to produce polymers with narrow molecular weight distribution and low content of high-molecular fractions, which simplifies the technology of producing rubber, improves said rubber properties and widens the field of use.

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Description

The invention relates to methods for producing a polymerization catalyst for butadiene and copolymerization of butadiene with isoprene and may find application in the synthetic rubber industry in the production of cis-1,4-polydienes.

A known method for the synthesis of a catalyst for the polymerization of butadiene or its copolymerization with isoprene, which consists in mixing in a hydrocarbon solvent butadiene, triisobutylaluminum (TIBA) and a specially synthesized catalytic component based on neodymium neodecanoate, holding the mixture for 15 minutes to 96 hours at 20 ÷ 50 ° C followed by the introduction of diisobutylaluminum hydride (DIBAG) at a molar ratio of butadiene: TIBA: catalytic component: DIBAG = (5 ÷ 30) :( 2 ÷ 10): 1: (2 ÷ 10) (US Pat. RF 2248845, B0IJ 37/04, C08F 4/52, prior, from 04.29.04). The process of (co) polymerization of butadiene is carried out in the presence of a halogenating agent (ethyl aluminum sesquichloride, diisobutyl aluminum chloride, silicon tetrachloride, methyl trichlorosilane), which, as a rule, is added to the monomer solution after the pre-formed catalytic complex is fed. The molar ratio of neodymium: halogen = 1: 1.47 ÷ 1.52. Moreover, an additional amount of DIBAG is always introduced into the monomer solution.

The catalytic component used to prepare the catalyst by the described method is synthesized by reacting neodymium oxide with neodecanoic acid in the presence of a catalyst selected from a number of chlorides of elements Ш, 1У, УШ groups of the Periodic system or zinc, having a pH of 3.6 ÷ 3.9 in aqueous solutions , and activators forming stable complexes with them. Activators selected from the group of esters, acetyl-acetone or chloroparaffins not only accelerate the synthesis of the catalytic component, but also activate the catalyst and also increase its stability.

Nevertheless, the polymerization rate of butadiene in the presence of such a catalyst is not high enough - the monomer conversion reaches 85–97% in only 3 hours.

A disadvantage of the described catalyst is also a too narrow range of halogen: catalytic component ratios (1.47 ÷ 1.52: 1), at which the highest activity is achieved. This makes it difficult to prepare a catalyst uniform in properties on an industrial scale.

The polydispersity coefficient of the obtained polymers is in the range of 2.58 ÷ 3.27.

A known method of producing a catalyst for the polymerization of butadiene and the copolymerization of butadiene with conjugated dienes, in particular, isoprene, mixing in a hydrocarbon solvent of a carboxylate or REE alcoholate, a conjugated diene and diisobutylaluminum hydride, keeping the mixture for 10-30 minutes with stirring, followed by the addition of tibia the molar ratio of REE: diene: DIBAG: TIBA: alkylaluminium halide equal to I: (2 ÷ 20) :( 3 ÷ 12) :( 6 ÷ 12) :( 1,5 ÷ 3). As the conjugated diene use piperylene or isoprene (US Pat. RF 2267497, C08F 4/52, prior, from 22.12.03). After keeping the catalytic mixture for 10-15 hours, it actively co (polymerizes) butadiene - a polymer yield of 87% can be achieved in 0.5 hours.

However, the polymers synthesized at all the indicated molar ratios of the components of the catalyst are characterized by a wide molecular weight distribution (MMP) —the polydispersity coefficient is 3.1–4.6.

In addition, the preparation of the catalytic mixture is complicated by the strict regulation of the reaction time of the REE compound, DIBAG and the conjugated diene (10-30 min), the violation of which, according to the authors of this application, negatively affects the polymerization rate.

The closest analogue is a method of producing a catalyst for the polymerization of butadiene and the copolymerization of butadiene with isoprene by introducing a rare earth element carboxylate and piperylene into an inert gas mixture of TIBA under inert gas, keeping the reaction mass for at least 10 minutes at 20-60 ° C, followed by the addition of DIBAG and aluminum alkyl aluminum (RF patent 2345092, C08F 2/00, prior. from 05.23.07).

The molar ratio of TIBA: REE: piperylene: DIBAG: alkylaluminium halide is 6 ÷ 12: 1: 1 ÷ 5 ÷ 20: 6 ÷ 12: 1,8 ÷ 3. After "ripening" for 0.5 hours at 40 ° C to 10-15 hours at 20 °, the catalyst exhibits high activity. The output of polybutadiene in 0.5 hours is 92-98%.

The method of preparation of the catalytic complex is quite simple: for example, a mixture of the first three ingredients can be prepared in advance in large quantities and subsequently be consumed to prepare the catalyst as necessary, which increases its standard.

However, the polymers obtained using such a catalyst are characterized by a wide MWD (polydispersity coefficient is 2.9-3.4). In addition, a common drawback of known methods for the synthesis of catalysts, according to the authors of this application, is that the resulting polymers contain a significant amount (more than 10%) of a fraction with a molecular weight (MM) of more than 1 million and, accordingly, have high values of viscosity "- 400-500 mm ² / s. This negatively affects the production technology of such polymers and limits the scope of their application.

The objective of the proposed technical solution is to develop a method for producing a highly active catalyst for (co) polymerization of butadiene, which allows to obtain polymers with a narrower MMP.

The problem is solved in that in the inventive method for producing a catalyst for (co) polymerization of butadiene by the interaction of components including triisobutylaluminum, a conjugated diene and a compound of a rare-earth element, holding the reaction mass and subsequent introduction of diisobutylaluminum hydride and alkylaluminum chloride, they are added to a mixture of 1 : 1 and the process is carried out at a molar ratio of triisobutylaluminum: conjugated diene: compound of rare earth eleme that: diisobutylaluminum hydride: alkyl aluminum (Chlorine) equal to ÷ 12 6: 1 20 ÷ 1: 6 ÷ 12: 1.5 ÷ 1.7.

The essence of the process is that first, in an atmosphere of inert gas and at ambient temperature, hydrocarbon solutions of triisobutylaluminum, conjugated diene and rare earth carboxylate are mixed and the reaction mass is held for at least 10 minutes at 20 ÷ 60 ° C, after which DIBAG and previously prepared a mixture of alkylaluminium chloride with TIBA at a molar ratio of chlorine-containing compound: TIBA equal to 1: 1.

As a rare-earth element compound, carboxylates formed by an individual lanthanide neodymium (TU 48-4-186-72) or a technical mixture of rare-earth metals, the so-called "Didim", containing at least 85% neodymium and praseodymium from the sum of all incoming metals (TU) are used HELL 11.46-89) and acids, for example neodecanoic, naphthenic, bis (2-ethylhexyl) phosphoric,

Piperylene (TU 38.10.3300-88) or butadiene (TU 38.103658-88) is used as the conjugated diene.

Ethylaluminium sesquichloride (EACC), isobutylaluminium sesquichloride (IBACC), diisobutylaluminium chloride (DIBAC), and isobutylaluminium dichloride (IBADC) are used as alkylaluminium chloride. Alkylaluminium halides before use for the synthesis of the catalyst are mixed at room temperature with TIBA in a molar ratio of 1: 1.

The components of the catalyst are introduced into the reaction sphere in the form of solutions in a hydrocarbon solvent.

Aliphatic (e.g. hexane, gasoline), aromatic (e.g. toluene), cycloaliphatic (e.g. cyclohexane) hydrocarbons can be used as a solvent.

The catalytic complex can withstand from 0.5 hours at 40 ° to 10 ÷ 15 hours at 20 ° C, after which it is used for (co) polymerization of butadiene.

Co (polymerization) of butadiene is carried out at a temperature of 0 ÷ 120 ° C, preferably 30 ÷ 70 ° C, in an organic solvent, for example, gasoline, hexane, cyclohexane or mixtures thereof.

The following are examples illustrating the invention.

Example 1

In a glass reactor with a magnetic stirrer, previously evacuated and heated, in an atmosphere of dry argon, load 1.96 ml of a solution of TIBA in toluene with a concentration of 1 m / l. Then, with stirring, 0.11 ml of piperylene and 1 ml of neodymium neodecanoate in hexane are introduced (concentration 0.22 m / l). The reaction mixture was incubated for 30 minutes at 20 ° C, and then 1.4 ml of DIBAG toluene solution with a concentration of 1.1 m / l and 0.61 ml of a previously prepared mixture of EAC (conc. 0.22 m / l) were added to it with stirring. ) and TIBA (conc. 1 m / l) in a 1: 1 molar ratio.

The molar ratio of catalyst components

TIBA: piperylene: neodymium: DIBAG: C1 is 9: 5: 1: 7: 1.5.

The resulting mixture was stirred for 3 hours at 20 ° C, then stirring was stopped and incubated for another 12 hours. After that, butadiene is used as a polymerization catalyst.

In a glass ampoule with a capacity of 80 ml, previously evacuated, heated and filled with argon, load 40 ml of a solution of 3.25 g of butadiene in gasoline. The ampoule is thermostated at 50 ° C and 0.139 ml of the catalyst solution is added to it with a syringe.

The polymer yield after 30 minutes is 3.09 g (95.0%).

The content of cis-1,4 units of 96.5%

M _w polybutadiene 295,000

M _n 146000

The coefficient of polydispersity of 2.0. The content of the fraction with MM≥10 ⁶ - 4.2%.

The kinematic viscosity of a 5% polymer solution in toluene is 190 mm ² / s.

Example 2

2.62 ml of a TIBA solution in cyclohexane with a concentration of 1 m / l was placed in a glass stirred reactor prepared according to Example 1. Then, with stirring, 0.44 ml of piperylene and 1 ml of neodymium neodecanoate in hexane are introduced with a concentration of 0.22 m / l. The reaction mixture was kept for 10 minutes at 40 ° C and then 1.2 ml of a solution of DIBAG in cyclohexane with a concentration of 1.1 m / l and 1.11 ml of a pre-prepared mixture of IBACX with a concentration of 0.11 m / l and TIBA ( conc. 1 m / l) in a molar ratio of 1: 1.

The molar ratio of the components of the catalyst TIBA: piperylene: neodymium: DIBAG: C1 = 12: 20: 1: 6: 1.5.

The resulting mixture was stirred for 0.5 hours at 40 ° C and then used as a polymerization catalyst for butadiene.

In a glass ampoule prepared as in example 1, load 40 ml of a solution of 3.25 g of butadiene in cyclohexane. The ampoule is thermostated at 70 ° C and 0.174 ml of the catalyst solution is added to it with a syringe.

The polymer yield after 30 minutes was 3.19 g (98.0%).

The content of cis-1,4-units 97.0%

M _w 315000

M _n 150,000

The polydispersity coefficient is 2.1.

Content of fraction with MM≥10 ⁶ 4.7%

The kinematic viscosity of a 5% polymer solution in toluene is 205 mm ² / s.

Example 3

In a glass reactor with a stirrer prepared analogously to example 1, 1.44 ml of TIBA in gasoline with a concentration of 0.9 m / l are placed.

Then, with stirring, 1.1 ml of a solution of butadiene in gasoline (concentration 2 m / l) and 2 ml of neodymium bis (2-ethylhexyl) neodymium phosphate in gasoline with a concentration of 0.11 m / l are introduced. The reaction mixture was stirred at 20 ° C for 30 minutes. Then, 2.4 ml of DIBAG in gasoline with a concentration of 1.1 m / l and 0.66 ml of a previously prepared mixture of EACC with a concentration of 0.22 m / l and TIBA (conc. 0.9 m / l) in molar are introduced into it 1: 1 ratio. The molar ratio of the components of the catalyst TIBA: butadiene: neodymium: DIBAG: C1 = 6: 10: 1: 12: 1.6. The resulting mixture was stirred for 3 hours at 20 ° C and then used as a catalyst for the copolymerization of butadiene with isoprene. For this, in a glass ampoule prepared as in Example I, 40 ml of a solution containing 2.9 g (53.7 mmol) of butadiene and 0.64 g (9.4 mmol) of isoprene in a mixture of gasoline (80% wt.) Are loaded and cyclohexane (20% wt.).

The mass ratio of monomers 82:18.

The ampoule is thermostated at 30 ° C and 0.22 ml of the catalyst solution is added to it.

After 30 minutes, the copolymer is discharged.

The product yield is 95.5%.

The copolymer contains 96.7% cis-1,4 units.

M _w is 285,000

M _n 129500

The polydispersity coefficient is 2.2.

The content of the fraction with MM≥10 ⁶ 5.1%

The kinematic viscosity of a 5% polymer solution in toluene is 175 mm ² / s.

Example 4

2.62 ml of TIBA in hexane (conc. 1 m / l), 0.03 ml of piperylene and 1 ml of didim naphthenate with a concentration in hexane of 0.3 m / l are charged into a glass stirred reactor prepared in analogy to Example 1. The mixture is stirred for 10 minutes at 60 °, then the temperature is reduced to room temperature and 2.7 ml of a solution of DIBAG in hexane with a concentration of 1 m / l and 1.1 ml of a pre-prepared mixture of IBADC (conc. 0.3 m / l) are successively introduced with stirring. ) and TIBA (conc. 1 m / l) in a 1: 1 molar ratio.

The molar ratio of TIBA: piperylene: didim: DIBAG: C1 = 9: 1: 1: 9: 1.7.

The resulting mixture was incubated for 10 hours at 20 ° C and used as a catalyst.

In a glass ampoule prepared as in example 1, load 40 ml of a solution containing 3.25 g of butadiene in hexane.

The ampoule is thermostated at 50 ° C and 0.149 ml of catalyst is added with a syringe.

After 30 minutes, the polymer yield is 97%.

The content of CIS-1,4-units of 96.7%

M _w polybutadiene equal to 290000

M _n 116000

The polydispersity coefficient is 2.5.

The content of the fraction with MM≥10 ⁶ 7.5%.

Kinematic viscosity 185 mm ² / s.

Example 5

1.69 ml of a solution of TIBA in toluene with a concentration of 1 m / l are placed in a stirred reactor prepared as in Example 1. Then, with stirring, 0.22 ml of piperylene and 1 ml of neodymium neodecanoate in hexane are introduced with a concentration of 0.22 m / l. The mixture was incubated for 30 minutes at 20 ° C. and then, with stirring, 1.4 ml of a solution of DIBAG in toluene with a concentration of 1.1 m / l and 0.88 ml of a mixture of DIBAC (s = 0.6 m / l) with TIBA (s = 1 m / l) in a 1: 1 molar ratio.

The molar ratio of the components of the catalyst TIBA: piperylene: neodymium: DIBAG: C1 = 8: 10: 1: 7: 1.5.

The mixture is kept under stirring for 30 minutes at 40 ° C and used as a catalyst for the polymerization of butadiene.

In a glass ampoule with a capacity of 80 ml, prepared as in example 1, load 40 ml of a solution of 3.25 g of butadiene in gasoline. The ampoule is thermostated at 50 ° C and injected with a syringe 0.142 ml of catalyst.

After 30 minutes, the polymer is discharged.

The product yield is 96.5%.

The content of cis-1,4-units is 97.0%.

M _w polybutadiene 312000.

M _n 142000,

The coefficient of polydispersity (M _w / M _n ) = 2.2

The content of the fraction with MM≥10 ⁶ 4.9%.

The kinematic viscosity of a 5% polymer solution in toluene is 200 mm ² / s.

Example 6 (control)

2.7 ml of TIBA in hexane (conc. 1 m / l), 0.03 ml of piperylene and 1 ml of didim naphthenate with a concentration in hexane of 0.3 m / l are loaded into a glass stirred reactor prepared in analogy to Example 1. The mixture is stirred for 10 minutes at 60 ° C, then the temperature is reduced to room temperature and 2.7 ml of a solution of DIBAG in hexane with a concentration of 1 m / l and 0.9 ml of IBADC (conc. 0.3 m / l) are successively introduced with stirring.

The molar ratio of TIBA: piperylene: didim: DIBAG: C1 = 9: 1: 1: 9: 1.8.

The resulting mixture was incubated for 10 hours at 20 ° C and used as a catalyst.

In a glass ampoule prepared as in example 1, load 40 ml of a solution containing 3.25 g of butadiene in hexane.

The ampoule is thermostated at 50 ° C and 0.149 ml of catalyst is added with a syringe.

After 30 minutes, the polymer yield of 92%

The content of CIS-1,4-units of 96.7%

M _w polybutadiene equal to 410000

M _n 124200

Polydispersity coefficient 3.3

Content of fraction with MM≥10 ⁶ 12.5%

Kinematic viscosity 480 mm ² / s.

Thus, the proposed method makes it possible to synthesize a highly effective catalyst for (co) polymerization of butadiene, which allows to obtain polymers with a narrow MMP ((M _w / M _n = 2.0-2.5) and a lower content of high molecular weight fraction with MM≥10 ^6. This makes the polymerization process more technologically advanced and energy-efficient, since it reduces the rate of overgrowth of the polymerization apparatus during continuous industrial production and reduces the load on the mixers.In addition, low kinematic viscosity values allow Use the resulting polymers in the production of high impact polystyrene.

Claims (1)

A method of producing a catalyst for (co) polymerization of butadiene by the interaction of components including triisobutylaluminum, a conjugated diene and a compound of a rare-earth element, holding the reaction mass and then introducing diisobutylaluminum hydride and alkylaluminium chloride, which consists in introducing an aluminum-aluminum chloride in a mixture of tri-isobutyl the process is carried out at a molar ratio of triisobutylaluminum: conjugated diene: compound of the rare earth element: diisobutylaluminium Rid: alkyl aluminum (for Cl) was equal to 12 ÷ 6: 1 20 ÷ 1: 6 ÷ 12: 1.5 ÷ 1.7.