MXPA01000616A - Method for polymerizing conjugated diolefins (dienes) with catalysts based on cobalt compounds in the presence of vinylaromatic solvents - Google Patents

Abstract

Conjugated diolefins, optionally combined with other unsaturated compounds that may be copolymerized with diolefins, are polymerized by conducting polymerization of the diolefins in the presence of catalysts based on cobalt compounds, organoaluminum compounds and modifiers in the presence of aromatic vinyl compounds at temperatures ranging from -30°C to +80°C. The invention provides a simple method for producing polydiolefin solutions such as polybutadiene with contents of 1,2-units of 10 to 30%in aromatic vinyl compounds which can be further processed to obtain ABS or HIPS.

Description

PROCEDURE FOR THE POLYMERIZATION OF CONJUGATED DIOLEFTNES (WITH USERS OF COALTO COMPONENTS BASED ON VINYLAROMETALLIC SOLVENTS) FIELD OF THE INVENTION The present invention relates to a process for the polymerization of conjugated diolefins with catalysts based on compounds of cobalt in the presence of aromatic vinyl compounds Description of the prior art Polymerization of conjugated diolefins in the presence of a solvent has been known for a long time and have been described, for example, by W. Hoffmann, Rubber Technology Handbook, Hanser Publishers (Cari Hanser Velarg) München, Vienna, New York, 1989. Thus, polybutadiene is currently predominantly manufactured by solution polymerization with the aid of Ziegler-Natta-type coordination catalysts, for example based on titanium compounds, of cobalt, nickel and neodymium, or in the presence of alkyl lithium compounds The solvent used in each case depends to a large extent on the type of catalyst used. Preference is given to using benzene or toluene as well as aliphatic or cycloaliphatic hydrocarbons. The disadvantage of the polymerization processes currently carried out for the production of polyolefins, such as for example BR, IR, or SBR, consists in the expensive preparation of the polymer solution for the isolation of the polymers, for example by drag with water vapor or direct concentration by evaporation. In addition, it is a disadvantage, especially when the polymerized diolefins have to be further processed as resilience modifiers for the applications of the synthetic materials, that the polymeric diolefins obtained have to be dissolved first in a second time.

Ref: 125995 new solvent, for example styrene, so that they can be further processed, for example, to give copolymers of acrylonitrile-butadiene-styrene (ABS) or high-resilience polystyrene (HIPS). A catalyst system based on TiCl4 / iodine / Al (iso-Bu) 3 is claimed in US Pat. No. 3 299 178 for the polymerization of butadiene in styrene with homogeneous polybutadiene formation. The copolymerization of butadiene and styrene with the same catalyst system by Harwart et al. in Plaste und Kautschuk, 24/8 (1977) 540 as well as the adequacy of the catalyst for the manufacture of polystyrene. It is known from US 4 311 819 the use of anionic initiators for the polymerization of butadiene in styrene. The disadvantage of the anionic initiators is that, in this case, butadiene-styrene (SBR) copolymers are formed, which allow only a slight increase in the microstructure relative to the butadiene units. Only the proportion in 1,2 or 1,4-trans units can now be increased by the addition of modifiers, which leads to an increase in the vitreous transition temperature of the polymer. It is not possible to obtain an SBR with high cis content with anionic initiators. This is a disadvantage primarily because SBR is formed in this process, which results in a further increase in vitreous transition temperature as the styrene content increases as compared to the homopolymer polybutadiene (BR). However, a high vitreous transition temperature of the rubber has a negative effect on the low temperature properties of the material when the rubber is used for resilience modification for example of HIPS or ABS. It has been described, for example, by Kobayashi et al. in J. Polym. Sci., Part A, Polym. Chem. 33 (1995) 2175 and 36 (1998) 241 a catalytic system consisting of halogenated acetates of the rare earths, such as Nd (OCOCCl3) 3 or Gd (OCOCF3) 3, with tri (isobutyl) aluminum and diethylaluminum chloride, which enables the copolymerization of butadiene and styrene in an inert solvent such as hexane. The drawback of these catalysts resides, in addition to the presence of inert solvents, in which the activity of the catalyst already decreases, with a reduced incorporation of styrene of approximately 5 mol per%, to a value situated below 10 g of polymer / mmol of catalyst per hour and in that the 1, 4-cis content of the polymer clearly decreases as the styrene content increases. There is described in US 5096970 and EP 304088 a process for obtaining polybutadiene in styrene using catalysts based on neodymium phosphonates, organic aluminum compounds, such as di (iso-butyl) aluminum hydride (DIBAH), and a Lewis halogenated acid, such as ethylaluminum sesquichloride, in which butadiene and styrene are reacted, without further addition of inert solvents, to give a 1,4-cis-polybutadiene. The drawback of this catalyst is that the polymers obtained have a very low content in units 1, 2, which is below 1%. This is a disadvantage because a higher 1.2 content in the polymer has a positive effect on the graft behavior between the rubber and the polymer matrix, for example homopolymers or copolymers of vinylaromatic compounds. The rubber solutions in styrene, described in the cited patent publications, were used for the manufacture of HIPS by reacting the rubber solutions in styrene, after removal of the converted monomers, with radical initiators. Detailed description of the invention.

The present invention therefore consisted in providing a process for the polymerization of conjugated diolefins in vinylaromatic solvents, with which it was possible to obtain polydienes with a content in units 1, 2 above 1%, being able to vary the content in units 1, 2 in a simple manner and being able to obtain a high conversion of the conjugated diolefins used, of more than 50%. Furthermore, practically no conversion of the vinylaromatic solvent used must take place, ie the conversion must be below 1%. The object of the present invention therefore consists in a process for the polymerization of conjugated diolefins, characterized in that the polymerization of the conjugated diolefins is carried out in the presence of catalysts consisting of: a) cobalt compounds, b) organoaluminum compounds and c) modifiers as well as in the presence of aromatic vinyl compounds, at temperatures of -30 ° C to + 80 ° C, the molar ratio of components a) being: b): c) in the range of 1: 10 to 1,000: 0 , From 1 to 100, the amount of component (a) used for the catalyst being from 1 μmol to 10 mmole, based on 100 g of the monomers used, and the amount being in aromatic vinyl compounds of 10 g to 2,000 g, based on 100 g of the monomers used. Preferably, the components a): b) are used: c) in the process according to the invention in the range from 1: 10 to 500: 0.5 to 50. As conjugated diolefins, they can be used in the process according to the invention, for example, 1,3-butadiene, 1,3-isoprene, 2,3-dimethylbutadiene, 2,4-hexa-diene, 1,3-pentadiene and / or 2-methyl-1,3-pentadiene.

Suitable cobalt compounds (component (a)) are those which are soluble in inert organic solvents and which are selected from the groups consisting of complexes of β-diketones with cobalt, II complexes of β-ketoacids with cobalt, III cobalt salts with organic acids with 6 to 15 carbon atoms IV complexes of halogenated cobalt compounds of the formula CoXaDb, means a halogen atom, a means the numbers 2 or 3, D means an organic compound, chosen from a group consisting of tertiary amines, alcohols, tertiary phosphines, ketones and N, N-dialkylamides, and b means a number from 0 to 6, as well as V organometallic complexes of cobalt with anions with p-bonds. As cobalt compounds (component (a)), which are soluble in organic solvents, there can be used, for example: (I) ß-diketone-cobalt complexes, with ß-diketones of the formula R'-CO-CR2-CO- R3, in which R1 to R3 can be the same or different and denote hydrogen or an alkyl group with 1 to 10, preferably with 1 to 4 carbon atoms, for example Co (Me-CO-CH-CO-Me) 2 and Co (Me-CO-CH-CO-Me) 3; (II) complexes of esters of cobalt ß-keto acids with keto acid esters of the formula R'-CO-CR2-CO-0-R3, where R1 to R3 may be the same or different and mean hydrogen or an alkyl group with 1 to 10, preferably 1 to 4 carbon atoms, for example Co (Me-CO-CH-CO-0-Me) 2, Co (Me-CO-CH-CO-0-Et) 2, Co (Me-CO) -CH-CO-O-Me) 3 and Co (Me-CO-CH 2 -CO-0-Et) 3; (ip) cobalt salts of organic acids with 6 to 15, preferably 6 to 10 carbon atoms, for example Co (octanoate) 2, CO (versatate) 2; (IV) complexes of halogenated cobalt compounds of the above formula CoXaDb, for example CoCl2- (pyridine) 2, CoBr2- (pyridine) 2, CoCl2- (PPh3) 2, CoBr2- (PPh3) 2, CoCl2- (vinylimidazole) 4, CoCl2- (EtOH); (V) organometallic complexes of cobalt with anions with p-bonds, for example tris- (p-allyl) -cobalt, bis- (p-allyl) -cobalt chloride, bis- (p-allyl) -cobalt bromide, iodide of bis- (p-allyl) -cobalt, bisacrylonitrile- (p-allyl) -cobalt, (1,3-butadiene) [1- (2-methyl-3-butenyl) -p-allyl] -cobalt, bis- (p-1, 5-cyclooctadienyl) - (tert-butyl-isonitrile) -cobalt, (p-cyclooctenyl) - (p-1, 5-cyclooctadienyl) -cobalt, (p-cycloheptadienyl) - (pl, 5-cyclooctadienyl) -cobalt, (bicyclo [3.3.0] octadienyl) - (p- 1, 5-cyclooctadienyl) -cobalt. The abovementioned catalysts based on cobalt compounds are known and have been described and explained in greater detail, for example in the following publications: B.A. Dolgoplosk et al., Polym. Sci, Ser. A. 36/10 (1994) 1380. L. Porri et al., Comp. Polym. Sci. 4/2 (1989) 53, O.K. Scharajew et al. Vysokomol. Soyed. A 38: No. 3 (1996) 447, M. Takeuchi et al., Polym. Int. 29 (1992) L. Porri et al., Macromol. Chem., Macromol. Symp. 48/49 (1991) 239, G. Ricci et al., Polym. Common. 29 (1988) 305, N.D. Golubeva et al. J. Polym. Sci .: Polym Symp. 68 (1980) 33 and S. S. Potapov et al. Vysokomol, Seyed. A 16: No. 1 1 (1974) 2515. Particularly suitable aluminum organic compounds of component (b) are alumoxanes and / or organoaluminum compounds. As alumoxanes, aluminum-oxygen compounds will be used, which, as is known to those skilled in the art, are obtained by compound contact. organic compounds of aluminum with condensation components, such as water and containing the non-cyclic or cyclic compounds of the formula (-Al (R) 0-) n, where R can be the same or different and mean a linear or branched alkyl group with 1 to 10 carbon atoms, which may also contain heteroatoms, such as oxygen or halogen. Especially R stands for methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, tere-butyl, n-octyl or iso-octyl, more preferably means methyl, ethyl or iso-butyl. Examples of alumoxanes which may be mentioned are methylalumoxane, ethylalumoxane and isobutylalumoxane, preferably methylalumoxane and isobutylalumoxane. The aforementioned alumoxanes have been described and explained in greater detail for example in "Alumoxanes" Macromol, Symp. 97 (1995). Organic compounds of aluminum are compounds which are formed by reacting compounds of the formula AlR3-d-Xd, where R can be the same or different and represent an alkyl group with 1 to 12 carbon atoms, a cycloalkyl group with 5 to 12 carbon atoms or an aryl group with 6 to 12 carbon atoms, X means a hydrogen or a halogen, such as chlorine, bromine, and d means a number from 0 to 2, with compounds of the formula HYR'e, where Y means an element of groups Vb and VIb of the Periodic System of the Elements, preferably means oxygen, sulfur and nitrogen, R 'may be the same or different and mean a hydrogen, an alkyl, cycloalkyl or aryl group with 1 to 12 carbon atoms and in accordance with the valence of Y means 1 or 2. As compounds of the formula AlR3-dXd, especially: trimethylaluminum, triethylaluminum, tri-n-propylaluminum, tri-iso-propylaluminum, tri-n- butylaluminum, tri-isobutylaluminum, tripentylaluminum, trihexylaluminum, tricyclohexyl aluminum, trioctylaluminum, diethylaluminum hydride, n-butylaluminum hydride, diisobutylaluminum hydride, diethylaluminum chloride, ethyl aluminum sesquichloride, dichloride ethylaluminum, ethylaluminum dibromide. diethyl aluminum bromide, diiodide. ethylaluminum, diethylaluminum iodide, di-isobutylaluminum chloride, octylaluminum dichloride, dioctylaluminum chloride. Preference is given to using: trimethylaluminum, triethylaluminum, triisobutylaluminum, trioctylaluminum, diisobutylaluminum chloride, octylaluminum dichloride. As compounds of the formula HYR'e, it is possible to use, in particular: water, alcohols, such as methanol, ethanol, n-propanol, iso-propanol, n-butanol, isobutanol, tere. -butanol, hexanol, octanol and glycol, phenols, such as for example phenol, methylphenol, ethylphenol, butylphenol, octylphenol, dodecylphenol, tert-butylphenol, bis-2,6,6-tert. butylphenol and 4-methyl-bis-2,6-tert-butylphenol, aliphatic and aromatic amines, such as methylamine, ethylamine, butylamine, phenylamine, dimethylamine, diethylamine, dibutylamine, diphenylamine, pyrrolidine and pyridine. Aluminum organole compounds have been described, for example, in Abel Stone, Wilkinson, Comprehensive Organometallic Chemistry, Pergamon Press Ltd. Oxford, 1995. As modifiers (component (c)), those compounds which are known to the skilled worker are particularly suitable. in the matter as Lewis bases. Especially preferred are Lewis bases which contain as a donor atom at least one element of groups Vb and VIb of the Periodic System of the elements, such as nitrogen, phosphorus, oxygen and sulfur, particularly preferably nitrogen or phosphorus. As modifiers, it is possible to use, in particular: pyridine, aliphatic or aromatic tertiary amines or aliphatic or tertiary aromatic phosphines, such such as, for example, pyridine, vinylimidazole, triethylphosphine and triphenylphosphine. In this context it will be indicated that the component cobalt compounds (a), the organic compounds of the aluminum of component (b) and the modifiers of component (c) can be used either alone or in mixtures with each other. The most convenient mixing ratio can easily be determined by means of corresponding pre-tests. In the process according to the invention, the catalysts will be used in quantities of preferably 10 μmoles to 5 mmoles, referred to 100 g of monomers. Of course it is also possible to use the catalysts in arbitrary mixtures with each other. The process according to the invention is carried out in the presence of aromatic vinyl compounds, especially in the presence of styrene, α-methylstyrene, α-methylstyrene-dimer, p-methylstyrene, vinylbenzene and / or other alkylstyrenes with 2 to 6 carbon atoms in the alkyl moiety, such as p-ethylstyrene and p-butylstyrene. In the process according to the invention, very particularly preferably in the presence of styrene, α-methylstyrene, α-methylstyrene-dimer and / or p-methylstyrene will be used. Solvents can be used alone or as a mixture; the most convenient mixing ratio can also easily be determined by means of corresponding preliminary tests. The amount of the aromatic vinyl compounds used is preferably from 30 to 1000 g, very particularly preferably from 50 to 500 g, based on 100 g of the monomers used.

The process according to the invention is preferably carried out at temperatures of 0 to 70 ° C. The process according to the invention can be carried out without pressure or with a higher pressure (from 0.1 to 12 bar). The process according to the invention can be carried out continuously or discontinuously, preferably in a continuous working mode. The solvents to be used in the process according to the invention (vinylaromatic compound) need not be removed by distillation but may remain in the reaction mixture. Thus, it is possible, for example, when styrene is used as a solvent, then to carry out a second polymerization of the styrene, obtaining an elastomeric polydiene in a polyethylene matrix. Analogously, acrylonitrile can be added to the polybutadiene solution in styrene, before carrying out the second polymerization. In this way ABS is obtained. Such products have a special interest as modified thermoplastics to resilience. Naturally, it is also possible to remove, after the polymerization, a part of the solvent used and / or the unconverted monomers, preferably by means of a distillation, if appropriate under reduced pressure, to obtain the desired polymer concentration. It is also possible to add other components to the polymer solution before or during the subsequent polymerization of the solvent, which can be initiated, in a known manner, by means of radicals or thermally, for example unsaturated organic compounds, such as acrylonitrile, methacrylate. of methyl, maleic anhydride, maleinimide, which can be copolymerized with the vinylaromatic solvent; and / or customary aliphatic and / or aromatic solvents such as benzene, toluene, ethylbenzene, dimethylbenzene, hexane, heptane or octane and / or solvents polar, such as ketones, ethers or esters, which are usually employed as solvents and / or diluents for the polymerization of vinylaromates. As already mentioned above, the process according to the invention is characterized by a special economy and by a good compatibility with the environment, since the solvent used can be polymerized in a subsequent stage, the polymer serving in the solvent , for the modification of the thermoplastics (for example, increased notch resilience). According to the process of the invention, the composition and, therefore, the properties of the obtained polymers can be varied very widely. By way of example, the content in units 1, 2, that is to say in double bonds located laterally in the polymer chain by variation of the composition of the catalyst, preferably by varying the modifiers, can be adjusted within specific limits. , without polymerization or copolymerization of the vinylaromatic solvent taking place. It is also possible to influence in a very simple way the molecular weights, the branching of the polymers and, thus, also the solubility of the polymers, such as by varying the concentration of the catalyst, the concentration in dienes. , of the temperature of the reaction or by the addition of suitable molecular weight regulators, such as hydrogen, 1,2-butadiene or cyclooctadiene. Another advantage of the process according to the invention lies in the fact that, in direct polymerization in styrene, it is also possible to manufacture and transform further in a simple manner those low molecular weight polymers which can only be transformed and stored with difficulty as solid products with high creep in cold or with high stickiness. The advantage of low molecular weight polymers is that the viscosity The solution in solution remains low, as is desirable, even with a high content of the polymers in vinylaromatic solvents and in which, in this way, the solutions can be easily transported and processed. Examples The polymerizations were carried out under the exclusion of air and humidity, under argon. The isolation of the polymers described in the individual examples from the solutions in styrene was carried out only for the purpose of characterizing the polymers obtained. The polymers can also be stored naturally, without isolation, in the styrene solution and subsequently converted accordingly. The styrene, used as solvent for the polymerization of the dienes, was stirred under argon for 24 hours on CaH2 at 25 ° C and was distilled off under reduced pressure at 25 ° C. To demonstrate that the polymerization is also possible with styrene, certain amounts of the stabilizer (2,6-di-tert.-butyl) (4-methyl-) phenol (- = Ionol) were added in some examples and the polymerization of the butadiene was carried out in the presence of the stabilizer. The determination of the styrene content in the polymer was carried out by means of 'H-NMR spectroscopy, the determination of the selectivity of the polybutadiene (content of 1,4-cis, 1,4-trans and 1,2) was carried out performed by IR spectroscopy. Examples 1 to 7. In a 0.5 liter bottle, which was equipped with a crown cap with integrated septum, under argon, at 25 ° C, to the styrene disposed in advance, the indicated quantities of liquid butadiene were added through of a cannula and, subsequently, the indicated amounts of the individual catalytic components in the order of methylalumoxane (MAO, 10% solution in toluene) and C0CI2 (pyridine) 2 (0.0235 molar solution in CH2Cl2). During the polymerization the temperature was adjusted by means of a water bath, the polymer was isolated, after the time of the reaction had elapsed, by precipitation of the polymer solution with methanol? BKF (BKF = bis [(3-hydroxy) (2,4-di-tert-butyl) (6-methyl) -fe-nil] methane) and dried for one day in the cabinet for drying under vacuum at 60 ° C. The magnitude of the face, the conditions of the reaction and the properties of the polymer have been given in Table 1. Table 1: Examples 1 to 7. Example 1 CoBr2 (pyridine) in mmoles 0.05 0.05 0.05 0 , 05 0.1 0.1 0.1 MAO in mmoles 5 5 5 5 10 10 10 Polymerization. Styrene in ml 75 75 75 75 75 75 75 1,3-Butadiene in g 18.1 20.9 29.5 20.6 23.2 18.1 18.5 Temperature in ° C 25 40 40 60 25 25 40 Reaction time in h 3 3 21 21 2 21 3 Polymer Yield in g 2.69 6.0 17.1 8 8.0 8.5 10.8 7, 7 BR with 1, 4-cis in% 92 95 92 89 92 93 93 1, 4-trans in% 5 3 4 6 5 4 4 1.2 in% 2 2 4 5 3 3 3 PS * in% 0.08 0 0, 25 0.95 0.12 0.16 0 PS *: Content of polymerized styrene, based on the amount used in% by weight.

Examples 8 to 13. To a 0.5 liter bottle, which was equipped with a crown plug with an integrated septum, under argon, at 25 ° C, to the styrene disposed in advance, the indicated amounts of liquid butadiene through of a cannula and then the indicated amounts of the individual components of the catalyst in the order of (2,6-di-tert.-butyl) (4-methyl) phenol (Ionol), methylalumoxane (MAO, 10% solution). % in toluene) and CoCl2 (PPh3) 2 (0.0086 molar solution in CH2C12). During the polymerization the temperature was adjusted by means of a water bath, the polymer was isolated, after the time of the reaction had elapsed, by precipitation of the polymer solution in methanol / BKF and dried for 1 day in the cabinet for Vacuum drying at 60 ° C. The magnitudes of the charge, the reaction conditions and the properties of the polymer have been given in Table 2. Table 2: Examples 8 to 13. Example 10 11 12 13 CoCl2 (PPh3) 2 in mmoles 0.011 0.011 0.00570, 011 0.011 0.011 MAO in mmoles 1 1 0.5 1 1 1 Ionol in mmoles 0.05 0.2 0.5 Polymerization. Styrene in ml 40 40 40 40 40 40 1, 3-Butadiene in g 7.2 10.0 8.3 8.5 8.8 7.1 Temperature in ° C 0 30 25 30 30 30 Reaction time in h 0 , 25 0.03 1 0.03 0.03 1.03 Polymer Performance in g 6.4 6.4 6.6 6.1 6.1 7.1 5.1 BR 1,4-cis in% 12 10 11 19 12 14 1, 4-trans in% 2 2 1 2 1 1,2 in% 86 88 88 79 87 85 PS * in% 0,35 0,58 0,51 0 , 34 0.63 0.45 PS * content of polymerized styrene, based on the amount used in% by weight. Examples 14 to 19. In a 0.5 liter bottle, which was equipped with a crown cap with integrated septum, under argon, at 25 ° C, to the styrene disposed in advance, the indicated quantities of liquid butadiene were added through of a cannula and then the indicated amounts of the individual components of the catalyst in the order of (2,6-di-tert.-butyl) (4-methyl) phenol (Ionol), methylalumoxane (MAO, 10% solution in toluene ) and CoBr2 (PPh3) 2 (0.0459 molar solution in CH2Cl2). During the polymerization the temperature was adjusted by means of a water bath, the polymer was isolated, after the time of the reaction had elapsed, by precipitation of the polymer solution in methanol / BKF and dried for one day in the cabinet for Dry in vacuum at 60 ° C. The magnitudes of the charge, the reaction conditions and the properties of the polymer have been given in Table 3. Table 3: Examples 14 to 19. Example 14 15 16 17 18 19 CoCl (PPh3) 2 in mmoles 0.01 0 , 05 0.01 0.01 0.01 0.01 MAO in mmoles 1 5 2.5 1 1 1 Ionol in mmoles 0.05 0.2 0.5 Polymerization. Styrene in ml 40 75 75 40 40 40 1, 3-Butadiene in g 7.1 21.1 20.8 9.6 9.1 7.1 Temperature in ° C 24 24 40 24 24 24 Reaction time in h 1.75 1.25 0.9 1 , 75 1.75 1.75 Polymer: Yield in g 5.1 18.6 8.5 6.1 6.5 7.5 BR with 1, 4-cis in% 12 15 16 16 12 9 1, 4- trans in% 2 4 2 1 1 1 1, 2 in% 86 81 82 83 87 90 PS * in% 0.28 0.74 0.40 0.17 0.18 0.39 PS * Polymerized styrene content, based on the amount used in% by weight. It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention is that which is clear from the present description of the invention.

Claims (7)

1. REIVI DICACIO ES Having described the invention as above, the content of the following claims is claimed as property: 1. Process for the polymerization of conjugated diolefins, characterized in that the polymerization of the diolefins is carried out in the presence of catalysts consisting of: (a) cobalt compounds, (b) organic compounds of aluminum and (c) modifiers as well as in the presence of aromatic vinyl compounds, at temperatures of -30 to 80 ° C, the molar proportion of the components being (a) :( b ) :( c) in the range from 1: 10 to 1,000: 0.1 to 100, the amount of the components used (a) of the catalyst being from 1 μmol to 10 mmole, based on 100 g of the monomers used, and the amount being found in vinyl aromatic compounds from 10 g to 2,000 g, based on 100 g of the monomers used.
2. 2. Process according to claim 1, characterized in that 1,3-butadiene, 1,3-isoprene, 2,3-dimethylbutadiene, 2,4-hexadiene, 1,3-pentadiene and / or 2 are used as conjugated diolefins. methyl-1,3-pentadiene.
3. 3. Method according to claims 1 and 2, characterized in that as cobalt compounds at least one compound from the group consisting of complexes of ß-diketones with cobalt, complexes of ß-ketoacids of cobalt, cobalt salts of organic acids is chosen with 6 to 15 carbon atoms, the complexes of halogenated cobalt compounds and / or cobalt organometallic complexes with anions with p-bonds.
4. 4. Process according to claims 1 to 3, characterized in that at least one compound selected from the group of alumoxanes is used as organic compounds of aluminum.
5. 5. - Process according to claims 1 to 3, characterized in that as organic compounds of aluminum is used at least one organoaluminum compound, which is formed by reaction of compounds of the formula R may be the same or different and mean an alkyl, cycloalkyl or aryl group with 1 to 12 carbon atoms, X means a hydrogen or a halogen and d means a number from 0 to 2, with compounds of the formula HYR'e, where Y means an element of groups Vb and VIb of the Periodic System of the Elements, R 'may be the same or different and mean a hydrogen, an alkylene group. cycloalkyl or aryl with 1 to 12 carbon atoms and according to the valence of Y means 1 or 2.
6. 6. Process according to claims 1 to 5, characterized in that at least one Lewis base, which contains, is used as modifiers. as a donor atom, at least one element of group Vb or VIb of the Periodic System of the Elements.
7. 7. Process according to claims 1 to 6, characterized in that styrene, α-methylstyrene, α-methyl styrene-dimer, p-methylstyrene, divinylbenzene and / or alkylstyrenes having 2 to 6 carbon atoms are used as aromatic vinyl compounds. alkyl rest.