RU2268894C1 - Method of preparing catalyst for polymerization/copolymerization of conjugated diene hydrocarbons - Google Patents

Abstract

FIELD: polymerization reaction catalysts.

SUBSTANCE: catalyst, which may be useful in production of cis-1,4-polymers and cis-1,4-copolymers in synthetic rubber industry, is prepared by mixing, in hydrocarbon solvent, rare-earth element compound, conjugated diene, alkylation agent, and halogen source, said halogen source being aryldimethyl halides or their mixtures with alkylaluminum chlorides. Process is carried out at molar ratio 1:(1-100):(10-100):(0.3-3), respectively.

EFFECT: increased catalytic activity and enabled production of low-dispersity polymers characterized by good performance properties resulting in a high level of physicochemical characteristics of rubber manufactured from these polymers.

2 cl, 1 tbl

Description

The invention relates to the field of petrochemistry, specifically to the preparation of polymerization and copolymerization catalysts for conjugated diene hydrocarbons, and may find application in the production of cis-1,4 polymers and cis-1,4 copolymers in the synthetic rubber industry.

A known method of producing a catalyst for the polymerization of dienes by preliminary reaction in a hydrocarbon solvent of a lanthanide carboxylate having an atomic number from 57 to 60 with triisobutylaluminum or diisobutylaluminum hydride, an organohalogen compound selected from among aluminum halides, alkylaluminum halides, and conjugated Mphenol. F 1/14, publ. 1974). The molar ratio of lanthanide: aluminum: halogen: conjugated diene is in the range 1: 4-200: 0.1-6: 5-500. The mixture is kept at room temperature from several minutes to several days, and then used in the polymerization of diene hydrocarbons.

The catalyst obtained in this way is characterized by time stability, but it has low activity (polybutadiene yield is only 74 kg / g-cerium) and relatively low stereoselectivity (cis-1.4 units in the polymer is about 97%).

A known method of producing a catalyst for the polymerization and copolymerization of conjugated dienes by reacting an organoaluminum compound, neodymium alcoholate and aluminum halides or alkylaluminum halides directly in a hydrocarbon solution of a (co) monomer (US Patent No. 4429089, IPC C 08 F 004/72, C 08 F 036/04, publ. . 1984). The molar ratio of lanthanide: aluminum: halogen is in the range 1: 1-120: 0.1-10.

The catalyst thus obtained is characterized by a higher activity than described in the previous analogue (polymer yield up to 200 kg / g-at of neodymium), but insufficient activity. The content of cis-1.4 units in the polymer in this case reaches 98.1%.

The closest in technical essence to the present invention is a method in which a conjugated diene polymerization catalyst is prepared by reacting in a hydrocarbon solvent compounds of individual rare-earth metals or mixtures thereof with an organohalogen compound selected from the group of primary, secondary or tertiary alkyl, cycloalkyl, aryl-, alkylaryl ", vinyl-, alkoxy-, epoxyhalides, and trialkylaluminum or diisobutylaluminum hydride (US Patent No. 4461883, IPC C 08 F 4/14, C 08 F 4/52, C 0 8 F 2/06, publ. 1984). The molar ratio of lanthanide: aluminum: halogen is in the range 1: 30-200: 0.5-3. The catalyst is prepared by mixing the components at room temperature in any order in the presence or absence of monomer and maintain 15 minutes, the Catalyst is stable in time, allows you to get polymers with cis-1,4-units up to 99%, its activity reaches 280 kg of polybutadiene per 1 g-atom of neodymium per hour. In the case of copolymerization using a catalyst of optimal composition in a molar ratio lanthanide: aluminum: halogen, equ ohm 1: 50: 2, the copolymer yield for 1 hour is more than 500 kg / g-atom of neodymium.

The disadvantages of the described method is that the organohalogen compounds used to prepare the catalyst are inaccessible and expensive; the obtained polybutadiene using the above catalyst has a high intrinsic viscosity (more than 5.15 dl / g), and the copolymer of butadiene with isoprene 6.02 dl / g; a significant consumption of the organoaluminum compound necessary to achieve maximum activity leads not only to an increase in the cost of the catalyst, but also to an increased ash content in the rubber, which narrows the scope of its application.

The objective of the proposed technical solution is to develop a method that allows to obtain a highly active catalyst for the polymerization and copolymerization of conjugated diene hydrocarbons using available components, as well as making it possible to obtain polymers with the necessary Mooney viscosity and low polydispersity, which ensures their good technological properties and a high level of physical -mechanical indicators of rubbers based on the obtained (co) polymers.

The problem is solved in that in the proposed method, the catalyst for the polymerization and copolymerization of conjugated diene hydrocarbons is obtained by reacting in a hydrocarbon solvent the compounds of the rare-earth element (A), the conjugated diene (B), the alkylating agent (C) and the halogen source (D), while as the source of halogen (D), use an aryldimethyl halide or a mixture of an aryldimethyl halide with an aluminum alkyl chloride, maintaining a molar ratio of components (A) :( B) :( C) :( D) equal to 1: 1-100: 10-100: 0.3-3 .

The molar ratio of aryldimethyl halide: alkylaluminium chloride in component (D) is maintained at 1: 0-99.

As the compound of the rare-earth element (A), salts formed by neodymium, praseodymium, lanthanum, cerium or mixtures thereof with alpha-branched saturated C ₆ -C ₂₀ or naphthenic acids are used, preferably neodymium neodecanoate, neodymium naphthenate, neodymium octanoate, praseodymium neodecanoate, praseodymium naphthenate, praseodymium octanoate, lanthanum neodecanoate, lanthanum octanoate, cerium neodecanoate, cerium octanoate, didim neodecanoate, didim naphthenate, didime octanoate.

Butadiene, isoprene, piperylene or mixtures thereof are used as conjugated diene (B).

As the alkylating agent (C), compounds from the group consisting of triisobutylaluminum (TIBA), diisobutylaluminium hydride (DIBAG), triethylaluminium (TEA) or a mixture of these compounds are used.

Aromatic and aliphatic hydrocarbons, for example, toluene, hexane, etc., are used as solvents for components (A), (B), (C), (D).

As the source of halogen (D), aryldimethyl halides, for example, such as hexachlor-p-xylene (HCCH), p-methyltrichloromethylbenzene (MTXMB), dichloro-p-xylene (DHPC), etc., and mixtures thereof with the following composition of aluminum alkyl : AlR _n Cl _3-n , R - aliphatic C ₂ -C ₈ hydrocarbon radical, n = 1-2. In the case of using the mixture, the separate administration of the aryldimethyl halide and the alkyl aluminum chloride is possible.

The use of aryldimethyl halides or mixtures thereof with alkylaluminium chlorides as a source of halogen (D) will significantly reduce the cost of the catalyst and, therefore, the polymer. The much lower toxicity and fire hazard of aryldimethyl halides and their mixtures with alkylaluminium chlorides in comparison with individual alkylaluminium chlorides makes it possible to use reagents in the form of concentrated solutions, which leads to a decrease in solvent consumption in the preparation of the catalyst. The high activity of the catalyst synthesized by the proposed method leads not only to a significant reduction in the consumption rates for the catalyst, but also to a lower ash content in the rubber, which makes it possible to use it not only in the tire industry, but also in the medical and food industries.

The use of highly active catalyst obtained by the proposed method leads to almost complete conversion of the monomer, which in turn allows to reduce the loss of both monomer and solvent during the regeneration of circulating reagents.

The catalyst is prepared by mixing solutions of the compound of the rare-earth element (A), conjugated diene (B), an alkylating agent (C) and a halogen source (D). After mixing all the components of the catalyst in the reactor, the mixture is kept for 0.5 to 24 hours at a temperature of 15-50 ° C and used in the polymerization and copolymerization of conjugated diene hydrocarbons, for example, such as butadiene, isoprene, piperylene.

(Co) polymerization is carried out in aliphatic, alicyclic or aromatic hydrocarbons, for example in hexane, cyclohexane, toluene, etc., at a temperature of 0-120 ° C. At the end of the polymerization, the catalyst is deactivated, and the polymer is precipitated by the introduction of ethanol containing an antioxidant.

The activity of the catalyst is estimated in kg of polymer per 1 g-atom of rare-earth metal for 1 hour. The resulting polymer is analyzed for cis-1,4 units, polydispersity (Mw / Mn) and Mooney viscosity.

The implementation of the proposed method for the preparation of a catalyst (co) polymerization of conjugated diene hydrocarbons is illustrated by the following examples.

Example 1

0.3 ml (0.0225 mmol) of a hexane solution of neodymium neodecanoate are added to a glass reactor preheated in a vacuum and filled with dry nitrogen, to which 0.1 ml (0.225 mmol) of a piperylene toluene solution, 0.25 are added successively with stirring ml (0.225 mmol) of a toluene solution of diisobutylaluminum hydride, 0.25 ml (0.225 mmol) of a toluene solution of triisobutylaluminum, 0.2 ml (0.01125 mmol) of a toluene solution of HCCH. The molar ratio of rare earth element: conjugated diene: alkylating agent: source of halogen is 1: 10: 20: 0.5.

The contents of the reactor are incubated for 24 hours at a temperature of 25 ° C until the complete maturation of the catalytic complex.

The resulting catalyst with a neodymium ion concentration of 0.020 g-at / L is used in the polymerization of butadiene. 40 ml of a hexane solution containing 3.24 g of butadiene are loaded into a glass ampoule preheated in vacuum at 150-200 ° C and filled with dry nitrogen with a self-tightening rubber stopper, the ampoule is thermostated at 60 ° C and 0.3 ml of the catalyst is added using a syringe . The molar ratio of butadiene to neodymium is equal to 10,000.

After 1 hour, the polymer is isolated, dried to constant weight. The conditions of the experiment and the data obtained are shown in the table.

Example 2

0.3 ml (0.0225 mmol) of praseodymium octanoate was added to a glass reactor, previously heated in vacuum and filled with dry nitrogen, to which 0.1 ml (1.12 mmol) of butadiene toluene solution, 0.5, was successively added with stirring. ml (0.225 mmol) of toluene solution of disobutylaluminium hydride, 0.2 ml (0.0067 mmol) of toluene solution of HCCH. The molar ratio of rare earth element: conjugated diene: alkylating agent: source of halogen is 1: 100: 10: 0.3.

The contents of the reactor are incubated for 24 hours at a temperature of 25 ° C until the complete maturation of the catalytic complex.

The resulting catalyst with a praseodymium ion concentration of 0.020 g-at / L is used in the polymerization of isoprene. 40 ml of a cyclohexane solution containing 4.08 g of isoprene are loaded into a glass ampoule preheated in vacuum at 150-200 ° C and filled with dry nitrogen with a self-tightening rubber stopper, the ampoule is thermostated at 60 ° C and 0.3 ml of catalyst is added via syringe . The molar ratio of isoprene to praseodymium is equal to 10,000.

After 1 hour, the polymer is isolated, dried to constant weight. The conditions of the experiment and the data obtained are shown in the table.

Example 3

0.3 ml (0.0225 mmol) of cerium naphthenate, to which 0.1 ml (0.45 mmol) of isoprene toluene solution is added, is added successively with stirring, 0.5 ml (0.5 ml) of isoprene to a glass reactor, preheated under vacuum and filled with dry nitrogen. ml (2.25 mmol) of toluene solution of triisobutylaluminum, 0.2 ml of toluene solution containing MTXMB (0.0004 mmol) and diisobutylaluminium chloride (DIBAC) (0.0668 mmol). The molar ratio of rare earth element: conjugated diene: alkylating agent: source of halogen is 1: 20: 100: 3.

The contents of the reactor are incubated for 24 hours at a temperature of 25 ° C until the complete maturation of the catalytic complex.

The resulting catalyst with a cerium ion concentration of 0.020 g-at / L is used in the copolymerization of butadiene and isoprene. In a glass ampoule with self-tightening rubber stopper preheated in vacuum at 150-200 ° C and filled with dry nitrogen, 40 ml of a toluene solution containing 2.754 g of butadiene and 0.612 g of isoprene are loaded. The molar ratio of butadiene to isoprene is 85:15. The ampoule is thermostated at 60 ° C and 0.3 ml of the catalyst is added via syringe. The molar ratio of monomers to cerium is equal to 10000.

After 1 hour, the polymer is isolated, dried to constant weight. The conditions of the experiment and the data obtained are shown in the table.

Example 4

0.3 ml (0.0225 mmol) of didim neodecanoate was added to a glass reactor preheated in a vacuum and filled with dry nitrogen, to which 0.05 ml (0.0112 mmol) of piperylene toluene solution, 0.05, were successively added with stirring. ml (0.0112 mmol) of isoprene toluene solution, 0.5 ml (0.675 mmol) of triethylaluminum toluene solution, 0.2 ml of toluene solution containing HCCH (0.0045 mmol) and ethyl aluminum sesquichloride (EAC) (0.0045 mmol). In this case, the molar ratio of rare earth element: conjugated diene: alkylating agent: source of halogen is 1: 1: 30: 0.4.

The contents of the reactor are incubated for 24 hours at a temperature of 25 ° C until the complete maturation of the catalytic complex.

The resulting catalyst with a concentration of didim ions of 0.020 g-at / L is used in the copolymerization of butadiene and piperylene. 40 ml of a hexane solution containing 2.754 g of butadiene and 0.612 g of piperylene are loaded into a glass ampoule preheated in vacuum at 150-200 ° C and filled with dry nitrogen with a self-tightening rubber stopper. The molar ratio of butadiene to piperylene is 85:15. The ampoule is thermostated at 60 ° C and 0.3 ml of the catalyst is added via syringe. The molar ratio of monomers to Didim is equal to 10000.

After 1 hour, the polymer is isolated, dried to constant weight. The conditions of the experiment and the data obtained are shown in the table.

Example 5

0.3 ml (0.0225 mmol) of neodymium neodecanoate is placed in a glass reactor preheated under vacuum and filled with dry nitrogen, to which 0.1 ml (0.45 mmol) of piperylene toluene solution, 0.5, are added successively with stirring ml (0.675 mmol) of toluene solution of diisobutylaluminum hydride, 0.2 ml of toluene solution containing DHPC (0.001 mmol) and diisobutylaluminum chloride (DIBAC) (0.044 mmol). The molar ratio of rare earth element: conjugated diene: alkylating agent: source of halogen is 1: 20: 30: 2.

The contents of the reactor are incubated for 24 hours at a temperature of 25 ° C until the complete maturation of the catalytic complex.

The resulting catalyst with a concentration of neodymium ions of 0.020 g-at / L is used for the polymerization of butadiene. 40 ml of a hexane solution containing 3.24 g of butadiene are loaded into a glass ampoule preheated in vacuum at 150-200 ° C and filled with dry nitrogen with a self-tightening rubber stopper, the ampoule is thermostated at 60 ° C and 0.3 ml of the catalyst is added using a syringe . The molar ratio of butadiene to neodymium is equal to 10,000.

After 1 hour, the polymer is isolated, dried to constant weight. The conditions of the experiment and the data obtained are shown in the table.

As can be seen from the above examples, the proposed method allows to obtain a highly active catalyst for the polymerization and copolymerization of conjugated diene hydrocarbons. The polymers obtained using the catalyst have a low polydispersity, which ensures their good technological properties and a high level of physical and mechanical properties of rubbers based on them.

Table Example No. Rare earth compound (A) Conjugated diene (B) Alkylating Agent (C) Halogen Source (D) Solvent The molar ratio (A) :( B) :( C) :( D) The molar ratio of aryldimethylgalogenide: alkyl aluminum chloride Conjugated Diene Hydrocarbon The content of cis-1,4-units,% Activity, kg / g-atom Polydispersity (Mw / Mn) Mooney viscosity, units one Neodymium neodecanoate Piperylene DIBAG CHIBA GHPK Hexane 1: 10: 20: 0,5 1-0 Butadiene 99,2 724 2.7 45.1 2 Praseodymium Octanoate Butadiene DIBAG GHPK Cyclohexane 1 100: 10: 0,3 1-0 Isoprene 99,4 645 2.9 49.4 3 Cerium Naphthenate Isoprene Chiba MTHMB DIBAH Toluene 1: 20: 100: 3 1:99 Butadiene isoprene 97.9 704 2,8 43,2 four Didima neodecanoate Piperylene isoprene Tea GHPK EASH Hexane 1: 1: 30: 0.4 1: 1 Butadiene piperylene 97.4 694 3.0 44.3 5 Neodymium neodecanoate Piperylene DIBAG DHPC DIBAH Hexane 1: 10: 30: 2 1:44 Butadiene 98.0 711 3,1 44,4

Claims (2)

1. A method of obtaining a catalyst for the polymerization and copolymerization of conjugated diene hydrocarbons by mixing in a hydrocarbon solvent a compound of a rare-earth element (A), a conjugated diene (B), an alkylating agent (C) and a halogen source (D), characterized in that as a source of halogen ( D) use an aryldimethyl halide or a mixture of an aryldimethyl halide and alkyl aluminum chloride, wherein the molar ratio of components (A) :( B) :( C) :( D) is maintained at 1: 1-100: 10-100: 0.3-3. 2. A method of producing a catalyst for the polymerization and copolymerization of conjugated diene hydrocarbons according to claim 1, characterized in that the molar ratio of aryldimethyl halide: alkylaluminium chloride in the source of halogen (D) is maintained equal to 1: 0-99.