RU2267497C2 - Method for preparing catalyst for polymerization of butadiene and copolymerization of butadiene with coupled dienes - Google Patents

Abstract

FIELD: chemistry of polymers, chemical technology, catalysts.

SUBSTANCE: invention relates to a method for preparing a catalyst used in polymerization of butadiene and copolymerization of butadiene with coupled dines. Method involves interaction of components comprising the compound of rare-earth element, diisobutyl aluminum hydride, triisobutyl aluminum, alkyl aluminum halide and coupled diene. Firstly, method involves mixing rare-earth element and coupled diene solutions with diisobutyl aluminum hydride solution, and the mixture is kept for 10-30 min at stirring, and then triisobutyl aluminum and alkyl aluminum halide solutions are added. After mixing all components the mixture is kept for 10-15 h in the following mole ratio of components: rare-earth element : diisobutyl aluminum hydride : triisobutyl aluminum : alkyl aluminum halide : coupled diene = 1:(3-12):(6-12):(1.5-3):(2-20), respectively, wherein rare-earth element carboxylate or alcoholate is used as a source of rare-earth element. Invention provides preparing the high-effective catalyst allowing preparing highly stereoregular polybutadiene and butadiene copolymer with the couples diene with simultaneous reducing the range of molecular-mass disposition by 3-3.5 times.

EFFECT: improved preparing method.

5 ex

Description

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

A known method of producing a butadiene polymerization catalyst by the interaction of a mixture of rare earth metal carboxylate (REE) with atomic number 57-71 with trialkylaluminum, pre-prepared and aged for 15 minutes, with an additional amount of trialkylaluminum and aluminum halide, which can be introduced in any sequence. The molar ratio of REE components: trialkylaluminum: alkylaluminium halide is 1: 10 ÷ 100: 0.4 ÷ 5, respectively (US Pat. Germany 2830080, С 08 F 236/06, prior. 08.07.78).

The disadvantage of this method is the low activity of the resulting catalyst so that the output of polybutadiene is only 190 kg / g-REE atom for one hour of polymerization at 56 ° C. In addition, the polybutadiene synthesized using such a catalyst has insufficient stereo-regularity (the content of cis-1,4-units is not more than 95%) and wide MMP (according to the authors of this application, M _w / M _n is about 14).

A known method of producing a catalyst for the polymerization of butadiene and its copolymerization with isoprene and other conjugated dienes, which consists in the interaction of trialkylaluminum or dialkylaluminium hydride with a rare earth metal compound (REE) with atomic number 21, 39, 57-71 and alkylaluminium halide (US Pat. US 3794604 1/14, prior. 24.9.71). The components are mixed in any order, but it is preferred that the organoaluminum compound is introduced into the reaction mixture prior to the introduction of the aluminum alkyl halide. The catalyst is prepared in the presence of a conjugated diene at a molar ratio of REE components: organoaluminum compound: alkylaluminium halide: diene equal to 1: 8 ÷ 100: 0.5 ÷ 3.5: 5 ÷ 500, and then kept for 1 hour to 7 days . Based on the description of the invention, the highest polymerization rate is achieved using a catalyst obtained at a molar ratio of cerium octanoate: diisobutylaluminium hydride: ethylaluminium dichloride: butadiene equal to 1: 20: 1: 50, respectively, and aged for 7 days. In this case, the yield of polybutadiene is 760 kg / g-atom of Ce in 1 hour. The resulting polymer contains 96.8-98.7% of cis-1,4 units.

The disadvantages of the method include the need for long aging of the catalyst to achieve maximum activity. In addition, according to the authors of this application, the resulting polymer is characterized by a wide molecular weight distribution: M _w / M _n is 17.

Closest to the proposed technical solution, the technical essence is a method for producing a catalyst for the polymerization of butadiene or its copolymerization with isoprene by reacting in a hydrocarbon solvent a carboxidate compound of a rare-earth element with an alkylaluminum halide, a conjugated diene and a mixture of dieobutylaluminium hydride (DIBAH) and triium equal to 1: 1 ÷ 5: 5 ÷ 60: 0.5 ÷ 20: 0.5 ÷ 39 (Pat. RF 2087488, C 08 F 36/06, prior.16. 03.94).

However, the catalyst obtained in this way is not sufficiently active. So, the highest polymer yield (example 6 of the description of the invention) is only 430 kg / g-at REE for 1 hour at 50 ° C, while the content of cis-1,4-units in the polymer does not exceed 95%, and the width of the molecular mass distribution of the polymer, according to the authors of this application, is at least 14.

The objective of the proposed technical solution is to develop a method for producing a catalyst for the polymerization of butadiene and copolymerization of butadiene with conjugated dienes, which has high activity and allows to obtain a highly stereoregular polymer with a narrower molecular weight distribution. This object is achieved in that in the inventive method for producing a catalyst for the polymerization of butadiene and copolymerization of butadiene with conjugated dienes by the interaction of components including a compound of a rare earth element, diisobutylaluminum hydride, triisobutylaluminum, alkylaluminium halide and a conjugated diene, first the mixture of DI for 10-30 minutes, and then add TIBA and alkylaluminium halide. The process is carried out with stirring in an atmosphere of inert gas (argon) and ambient temperature. The molar ratio of REE: DIBAG: TIBA: alkylaluminium halide (according to Cl): conjugated diene is 1: 3 ÷ 12: 6 ÷ 12: 1,5 ÷ 3: 2 ÷ 20. As the aluminum alkyl halide, isobutylaluminium sesquichloride (IBACC), isobutylaluminium chloride (IBADC), diisobutylaluminium chloride (DIBAC) are used. The components of the catalyst, with the exception of the conjugated diene, are introduced as a solution in a hydrocarbon solvent. Aliphatic (e.g., gasoline), aromatic (e.g., toluene), or cycloaliphatic (e.g., cyclohexane) hydrocarbons may be used as a solvent.

As a rare-earth element compound, carboxylates or alcoholates formed by an individual neodymium lanthanide (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 are used (TU AD 11.46-89), and acids, for example naphthenic, α- and α, α'-branched monocarboxylic (TU 2431-200-00203312-2000).

As the conjugated diene, piperylene (TU 38.103300-83), isoprene (TU 38.103653-88), butadiene (TU 38.103658-88), 2-ethylbutadiene, 4-methylpentadiene, 1,3-cyclohexadiene, etc. Alkylaluminium halide and TIBA (TU (TU) 38.1031.54-79) are entered in any sequence. After mixing all the components of the catalyst, the mixture is incubated for 10-15 hours and used for the polymerization of butadiene and its copolymerization with conjugated dienes.

The polymerization is carried out at a temperature of 0-80 ° C, preferably 30-60 ° C, in an organic solvent, for example heptane, toluene, cyclohexane or a mixture of isoamylenes. The activity of the catalyst is estimated in kg of polymer obtained per 1 g-atom of rare-earth element in 1 hour. Butadiene or its mixture with isoprene or piperylene is used as a monomer. The following are examples illustrating the invention.

Example 1

In a glass reactor with a magnetic stirrer, previously evacuated, warmed up and filled with dry argon, 2 ml of a solution of neodymium carboxylate in toluene (concentration 0.15 mol / L) are loaded, stirring is switched on and 0.1 ml of piperylene and 2 ml of solution are introduced at room temperature DIBAG in toluene (concentration 1.35 mol / L). The reaction mixture was kept under stirring for 15 minutes, after which 0.5 ml of a solution of IBASX in toluene (concentration of Cl ions 1.2 ion / L) and 5.4 ml of TIBA in toluene (concentration 0.5 mol / L) were successively added to it. . The molar ratio of REE: DIBAG: TIBA: IBASH (Cl): piperylene = 1: 9: 9: 2: 5. The resulting reaction mixture was stirred for 3 hours, after which the stirring was stopped, and the mixture was kept for 10 hours and used as a catalyst.

An 80 ml glass ampoule pre-evacuated and filled with dry argon is charged with 40 ml of a solution of butadiene in heptane containing 3.25 g of butadiene. The ampoule is thermostated at 50 ° C and 0.2 ml of the catalyst solution is added via syringe. After 30 minutes, the polymer was isolated. The polymer yield is 943.3 kg / g-atom of neodymium in 1 hour. Polybutadiene contains 98.6% cis-1,4 units, has an intrinsic viscosity of 3.2 dl / g and a molecular weight distribution of 3.3.

Example 2

In the conditions of example 1, but using gasoline as a solvent, 0.04 ml of piperylene, 2 ml of neodymium N-butylate solution (concentration 0.15 mol / l) and 0.66 ml DIBAG solution (concentration 1.35 mol / l). The mixture is kept under stirring for 10 minutes, and then 0.37 ml of DIBAC solution (Cl ion concentration ^is 1.2 ion / L) and 7.2 ml of TIBA solution (concentration 0.5 mol / L) are introduced into it. The molar ratio of REE: DIBAG: TIBA: DIBAC (Cl): piperylene = 1: 3: 12: 1.5: 2.

The resulting mixture was stirred for 2 hours, then stirring was stopped, and the mixture was incubated for 13 hours and used as a catalyst.

The polymerization of butadiene is carried out under the conditions of example 1, but in cyclohexane. The polymer yield is 710 kg / g-atom of neodymium in 1 hour. Polybutadiene contains 98.2% cis-1,4 units, has an intrinsic viscosity of 5.8 dl / g and a molecular weight distribution of 3.1.

Example 3

Under the conditions of example 1, but using cyclohexane as a solvent, 2 ml of a solution of Didim carboxylate (concentration 0.15 mol / L), 2.64 ml of a solution of DIBAT (concentration 1.35 mol / L) and 0.4 ml of isoprene are mixed . The mixture is kept under stirring for 30 minutes, and then 3.6 ml of TIBA solution (concentration of 0.5 mol / L) and 0.75 ml of IBADC solution (Cl ion concentration of 1.2 g-ion / l) are introduced into it.

The molar ratio of REE: DIBAG: TIBA: IBADH (Cl): isoprene = 1: 12: 6: 3: 20.

The resulting mixture was stirred for 2.5 hours, and then left without stirring for 12 hours and used as a catalyst. The copolymerization of butadiene and isoprene in a molar ratio of 75:25, respectively, is carried out under the conditions of example 1, but in toluene.

The copolymer yield is 750 kg / g-REE atom for 1 hour.

The composition of the copolymer: 74.8 mol%. butadiene units and 25.2 mol%. isoprene units. The copolymer contains 98.0% cis-1.14 units, has an intrinsic viscosity of 4.6 dl / g and a molecular weight distribution of 4.6.

Example 4

Under the conditions of example 1, but using toluene as a solvent, 2 ml of neodymium carboxylate solution (concentration 0.15 mol / l), 0.2 ml piperylene and 1.32 ml DIBAG solution (concentration 1.35 mol / l) are mixed . The mixture is kept under stirring for 10 minutes, and then 6 ml of TIBA solution (concentration of 0.5 mol / L) and 0.62 ml of DIBAC solution are introduced into it. The molar ratio of REE: DIBAG: TIBA: DIBAC (Cl): piperylene = 1: 6: 10: 2.5: 10. The resulting mixture was stirred for 1 hour, and then incubated for another 10 hours without stirring and used as a catalyst.

The copolymerization of butadiene and piperylene in a molar ratio of 85:15, respectively, is carried out under the conditions of example 1, but in a mixture of isoamylenes.

The copolymer yield is 710 kg / g-REE atom for 1 hour. The composition of the copolymer: 85.2 mol%. butadiene units and 14.8 mol%. piperylene units. The copolymer contains 98.0% cis-1,4 units, has an intrinsic viscosity of 4.0 dl / g, and a molecular weight distribution of 4.3.

Example 5

Under the conditions of Example 1, but using cyclohexane as a solvent, 2 ml of a solution of neodymium carboxylate (concentration 0.15 mol / L), 0.5 ml of butadiene and 2 ml of DIBAG solution (concentration 1.35 mol / L) are mixed. The mixture is kept under stirring for 15 minutes, and then 5.4 ml of a TIBA solution with a concentration of 0.5 mol / L and a 0.5 ml of a DIBAC solution (concentration 1.2 mol / L) are introduced into it. The molar ratio of REE: DIBAG: TIBA: DIBAC: butadiene = 1: 9: 9: 2: 20. The resulting mixture was stirred for 1 hour, and then incubated for another 10 hours without stirring and used as a catalyst.

The polymerization of butadiene is carried out under the conditions of example 1, but in gasoline.

The copolymer yield is 830 kg / g-atom of neodymium in 1 hour. Polybutadiene contains 98.2% cis-1,4 units, has an intrinsic viscosity of 3.0 dl / g and a molecular weight distribution of 3.0.

Thus, the proposed method makes it possible to obtain a highly active catalyst that allows the production of highly stereoregular polybutadiene and butadiene copolymers with conjugated dienes with a much narrower molecular weight distribution.

Claims (1)

A method of obtaining a catalyst for the polymerization of butadiene and the copolymerization of butadiene with conjugated dienes by the interaction of components including a compound of a rare-earth element (REE), diisobutylaluminium hydride (DIBAG), triisobutylaluminum (TIBA), an alkylaluminium halide and a conjugated diene, which differs by mixing diene and a solution of diisobutylaluminum hydride, the mixture is kept for 10-30 minutes with stirring, and then a solution of triisobut aluminum and a solution of aluminum alkyl halide, after mixing all the components, the mixture is kept for 10-15 hours, with the following molar ratio: REE: DIBAG: TIBA: alkyl aluminum halide: conjugated diene = 1: (3 ÷ 12) :( 6 ÷ 12) :( 1 , 5 ÷ 3) :( 2 ÷ 20), moreover, the carboxylate or rare earth alcoholate is used as a rare-earth element.