High-mooney ndbr having mooney jump.

HIGH NUMBER VALUE OF MOONEY

Field of the Invention

The invention relates to a method for achieving a gradual increase in Mooney viscosity in the production of high molecular weight polybutadiene having a content> 95% by weight of cis-1.4 units and having a low content of 1 , 2-vinyl <1% by weight.

Polybutadienes are used as important constituents of rubber mixtures in the tire industry, and it is desirable to achieve an improvement in the final properties, for example a reduction in rolling resistance and abrasion value. Another area of ​​application is provided through golf ball cores or shoe soles, where high rebound resilience is a major issue.

Polybutadienes that have a high content of cis-1.4 units have been produced on a large industrial scale for quite some time and are used in the production of tires and other rubber products, and also for impact modification of polystyrene.

Background of the Invention

Currently, the high content of cis-1.4 units is achieved almost exclusively by the use of catalysts based on the compounds of rare earth metals, as described by way of example in EP-A 1 0 011 184 and in document EP-B-A1 0 007

-2027.

It is known from the prior art that polybutadienes specifically catalyzed by neodymium within high cis polybutadienes have particularly advantageous properties in relation to rolling resistance, abrasion value and rebound resilience. The catalyst systems used play an important part in the production of polybutadienes.

Ά As an example, the neodymium catalyst used in industry is a Ziegler / Natta system formed by a plurality of catalyst components. Catalyst formation involves the formation of different catalyst centers, resulting in a at least bimodal molar mass distribution in the polymer. The 3 known catalyst components of the Ziegler / Natta catalyst system are mostly formed by a neodymium source, a chloride source and an organoaluminum compound, these being mixed under particular temperature conditions in a wide variety of ways, once they are has prepared the catalyst system, with or without curing, for the polymerization process.

The prior art discloses a plurality of production processes for Ziegler / Natta catalyst systems used for the production of polybutadienes.

Another known document of the prior art is EP 0 127 236, in which the catalyst is produced by mixing neodymium oxides and neodymium alcoholates, and carboxylates, with organometallic halides, and also with an organic compound at a temperature of 20 ° C to 25 ° C.

-3 It is also possible to mix said 4 components at a temperature of 50 ° C to 80 ° C. In this variant, the mixture is cooled to a temperature of 20 to 25 ° C, and then DIBAH is added. No mention is made of curing.

EP 1 17 6 ​​157 B1 discloses a process for the production of polybutadienes with a lower proportion of Mooney's viscosity of dissolution / viscosity, in which catalyst production uses a pre-forming process. In this case, neodymium versatate is mixed first at 50 ° C with DIBAH and isoprene, then this mixture is cooled to 5 ° C, and then ethylaluminum sesquichloride (EASC) is added. Curing can take place from a number of minutes to a number of days at a temperature of 10 ° C to -80 ° C. During the polymerization process, comonomers, for example a bisdiene, are added in order to increase the degree of branching of the polymer and, thus, also to obtain the very restricted proportion of solution viscosity / Mooney viscosity. Due to the coupling by means of bisdiene, the number of chain ends per molecule in the resulting branched polymer is at least 4, while the linear molecules are only 2.

The number of chain ends in the polymer is directly correlated with energy dissipation. As the number of free chain ends increases, the dissipation of energy through the polymer also increases. However, as the energy dissipation decreases, the rolling resistance of the polymer as an example also decreases, and its rebound resilience improves. For an identical molar mass, therefore, the

-4 final properties of a linear polymer having only 2 chain ends per molecule are therefore always better than those of a branched polymer.

It is known that commercially produced polymers have a statistical molar mass distribution and the extent of the molar mass distribution is influenced by the catalyst production process.

The term gradual increase in Mooney viscosity and similar expressions such as gradual increase in Mooney value or Mooney jump refer to techniques that significantly increase the Mooney viscosity of polymers.

The ability to increase the molecular weight of elastomeric unsaturated diene polymers is important for several reasons. This allows the initial production of low molecular weight parental polymers, with the great advantage, in the currently used dissolution polymerization techniques, of introducing lower viscosities in the cement (dissolution of the polymer in the organic solvent medium used in the process of polymerization) and allow operation with higher solids contents in the cement, since a better heat transfer is achieved. It is also possible to reduce the cold flow of these diene polymers, thereby increasing their capacity for oil expansion.

It is also known from the prior art that the use of solution polymerization methods for the direct production of high molecular weight polymers, in particular of molecular weight neodymium catalyzed polybutadiene

-5 particularly high, it is particularly complicated and not profitable due to the high viscosities of dissolution. There are difficulties with agitation. Other phenomena are the heterogeneity of the polymerization system and the drastically reduced heat transfer. The direct polymerization process that extends to high molecular weights, therefore, would require lower polymer production rates due to a lower solids content in the reaction space. This type of process increases the costs of polymer production considerably.

Although it is known that the pre-forming process can alter the catalytic effect of Nd catalysts, and these pre-formed Nd catalysts provide polymers with a relatively low cold flow, the pre-forming process mostly reduces the activity of the Catalyst and, therefore, the consumption of neodymium sometimes increases considerably.

Furthermore, it is known that low flow cold polydiene can be produced if diene polymers are treated after the polymerization process with diazufre dichloride, sulfur chloride, thionyl chloride, diazufre dibromide or thionyl bromide (German document Auslegeschrift 12 60 7 94). However, the method described in German Auslegeschrift 12 60 794 for the production of elastomeric diene polymers is such that said process is inappropriate for high molecular weight neodymium catalyzed polybutadiene if the gradual increase in Mooney's value is at least 50% higher than the Mooney viscosity of the polymer after the polymerization process, because the

-6 gradual increase of the polymer exhibits gel formation, and this reduces the operating time of the reactor, due to deposits on the internal walls of the reactor. The maintenance and cleaning of the reactors is time consuming and expensive. In addition, there is a risk that the gel content is present in the current polymer and, therefore, cannot be used for tire applications.

Similarly, document DE 44 36 059 Al describes a method for achieving a gradual increase in the molecular weight of diene rubbers catalyzed by Nd, in which the intrinsic odor of the polymer is reduced by means of a depressurization step after polymerization process, in order to remove all the low boiling constituents of the reaction mixture. The gradual increase in Mooney value is approximately 27% higher than the Mooney viscosity of diene rubber after the polymerization process.

Summary of the Invention

Therefore, the objective of the present invention is to provide a simple, efficient and cost-effective process to achieve a gradual increase in Mooney viscosity, in which the gradual increase in Mooney viscosity is at least 50% greater than Mooney viscosity of the polymer after the polymerization process and at the same time does not exhibit gel formation or exhibit gel formation in a non-significant way.

Detailed description of the invention

-7 A process of the type mentioned in the introduction is proposed in order to achieve the objective, and includes

1) polymerize at least one monomer selected from

<td>butadiene</td><td>or</td><td>isoprene to</td><td>temperatures of -20 ° C</td><td>to 150</td><td>° C</td><td>in</td>

<td>presence</td><td>from</td><td>at least</td><td>an organic solvent</td><td>inert</td><td>Y</td><td>in</td>

<td>presence</td><td>from</td><td>at least one</td><td colspan="3">carboxylate based catalyst</td><td>from</td>

<td>neodymium,</td><td></td><td></td><td></td><td></td><td></td><td></td>

2) subsequently terminate the polymerization by adding protic compounds and

3) then add sulfur chlorides to the polymer, and before the addition treat this sulfur chloride with a carboxylic acid, fatty acid and / or fatty acid ester.

Another term used for the addition of sulfur chlorides to the polymer is the modification of the polymer.

Surprisingly, it was discovered that the treatment of sulfur chlorides before the addition of a carboxylic acid, fatty acid and / or fatty acid ester allows to achieve a reaction of gradual increase or major modification, without any unwanted gel formation as a result Of the same.

It is assumed - although without any intention to adopt particular theory - that treatment with a carboxylic acid, fatty acid and / or fatty acid ester improves the solubility of sulfur chloride in the polymerization solvent, in particular hexane, and thus guarantees the uniform distribution of sulfur chloride in the polymer, thus allowing to avoid, or at least reduce, local crosslinking. This means avoiding or reducing gel formation. In this way, it is possible to control the reactivity of the chloride of

-8azufre.

Surprisingly, it has been found that the gel content of the polybutadiene produced by the claimed method is preferably smaller than 1% by weight, preferably smaller than 0.3% by weight, particularly preferably smaller than 0 , 2% by weight. The method for determining the gel content is described below.

Now the terminology used is explained:

Initial Mooney Viscosity: Mooney viscosity (ML 1 + 4 100 ° C) after polymerization of the polymer, that is, after step 2).

Final Mooney Viscosity: Mooney viscosity (ML 1 + 4 100 ° C) after modification or after the gradual increase of the Mooney value or a gradual increase reaction of the polymer (gradual increase polymer), ie after step 3 ).

Gradual increase polymer: high molecular weight polybutadiene after modification, after gradual increase in Mooney value or after gradual increase reaction.

It is preferable to use Ziegler-Natta catalysts based on rare earth metal compounds, for example cerium compounds, lanthanum compounds, praseodymium compounds, gadolinium compounds or neodymium compounds, which are soluble in hydrocarbons. It is particularly preferred to use the corresponding salts of the rare earth metals as ZieglerNatta catalysts, examples of the same neodymium carboxylates, in particular neodymium neodecanoate, neodymium octanoate, neodymium naphthenate, 2,2 2,2-diethylhexanoate

ϊ neodymium or neodymium 2,2-diethylheptanoate, or any of the corresponding salts of lanthanum or praseodymium. Ziegler-Natta catalysts which can also be used comprise catalyst systems based on metallocenes, as described by way of example in EP-A 1025136 and in EPA 1078939.

It is preferable that the claimed method is based on the following steps:

a) Catalyst production with or without pre-forming process with the use of neodymium-based catalyst systems formed by component A: an alcoholate or a neodymium carboxylate, preferably neodymium versatate, component B: a dialkylaluminium hydride, preferably hydride of diisobutylaluminum (DIBAH), component C: a diene, preferably butadiene or isoprene and component D: at least one organometallic halide, preferably ethylaluminum sesquichloride (EASC),

<td>b)</td><td>polymerization of</td><td>monomers to</td><td>a</td><td>Temperature of -</td>

<td> 20</td><td>° C to 150 ° C,</td><td></td><td></td><td></td>

<td>c)</td><td>use of compounds</td><td>protics</td><td colspan="2">to finish the</td>

<td colspan="2">polymerization and</td><td></td><td></td><td></td>

<td>d)</td><td>addition of chlorides of</td><td>sulfur in</td><td>the</td><td>what are the</td>

sulfur chlorides with a carboxylic acid, fatty acid and / or fatty acid ester before the addition.

The dienes that can be used are butadiene, isoprene, pentadiene and 2,3-dimethylbutadiene, in particular butadiene and isoprene. The mentioned dienes can be used individually or mixed with each other, producing in this way

-10 or well homopolymers or copolymers of the mentioned dienes.

Once the catalyst system has been produced, the polymerization process in organic solvents is implemented. These solvents must be inert to the catalyst system used. Examples of suitable materials are aromatic, aliphatic and cycloaliphatic hydrocarbons such as benzene, toluene, pentane, n-hexane, isohexane, heptane, isomeric pentanes and cyclohexane. These solvents can be used individually or in combination. Preference is given to cyclohexane and n-hexane. Mixing with polar solvents is also possible.

The amounts of inert and organic solvents used are from 200 to 900 parts by weight, based on 100 parts by weight of monomers. Preference is given from 300 to 500 parts by weight.

The polymerization process can be carried out continuously or in batches.

<td>Is carried out</td><td>the process of</td><td>polymerization</td><td>to one</td>

<td>-20 temperature</td><td>° C to 150 ° C,</td><td>preferably</td><td>from 0 to</td>

<td>130 ° C</td><td></td><td></td><td></td>

<td>The process of</td><td>polymerization</td><td>You can use</td><td>methods</td>

conventional and can comprise one or more stages, in batches or continuously. Preference is given to the continuous process in a reactor cascade formed by a plurality of reactors, preferably at least 2, in particular 2

6.

protic compounds, that is the process of

Once the desired conversion has been achieved, the catalyst is normally deactivated by the addition of polymerization. The amount of protic compounds is

-11 preferably from 0 to 1 phr, based on the monomer used.

It is preferable that the protic compounds involve carboxylic acids and / or fatty acids.

It is preferable to use stearic acid or lauric acid for deactivation of the polymerization process.

It is also possible, once the desired conversion has been achieved, to react the catalyst with one or more reactive polar organic compounds which, after reaction with the catalyst, can be attached as a functional terminal group to the polymer chain.

It is also possible, although not essential, to carry out a depressurization step after the polymerization process, in order to remove all the low boiling constituents of the polymer.

Sulfur chlorides are mixed with the resulting polymer, and these sulfur chlorides are pretreated with carboxylic acid, fatty acid and / or fatty acid ester. For pretreatment, the carboxylic acid, fatty acid and / or fatty acid ester is mixed with sulfur chlorides.

The quantitative proportion of sulfur chlorides used in relation to carboxylic acid, fatty acid and / or fatty acid ester is preferably 1: 0.01 to 1:10.

It is preferable that the carboxylic acid involves compounds selected from the group of carboxylic acids having 8 to 20 carbon atoms, an example being versatile acid, octanoic acid or isooctanoic acid.

It is preferable that the fatty acid involves saturated, mono- or polyunsaturated animal or vegetable fatty acids, such as lauric acid, myristic acid, palmitic acid or oleic acid.

-12 It is preferable that the fatty acid ester involves saturated animal or vegetable, mono- or polyunsaturated, modified or natural fatty acid esters, such as epoxidized soybean oil (ESBO).

It is preferable that sulfur chlorides involve diazufre dichloride, sulfur dichloride and / or thionyl chloride. The use of diazufre dichloride to carry out the modification is particularly preferred.

The added amounts of sulfur chlorides, preferably diazufre dichloride, are generally of

0.05 to 0.7 parts by weight, preferably 0.1 to

0.4 parts by weight, per 100 parts by weight of diene rubber.

Normally, the temperatures at which the modification takes place are from 20 ° C to 150 ° C, preferably from 50 to

120 ° C.

In the claimed method, sulfur chlorides pretreated with carboxylic acid, fatty acid and / or fatty acid ester are stirred with the polymer for approximately 5 to 60 minutes.

Conventional amounts of conventional stabilizers can be added to the polymer solution before processing. Examples of stabilizers used are spherical hindered phenols, for example 2,6-di-tert-butyl-4,5-methylphenol, 4,6-bis (octylthiomethyl) -o-cresol or 3- (3,5-di-tert-butyl- Octadecyl 1,4-hydroxyphenyl) propionate or aromatic amines, such as N- (1,3-dimethylbutyl) -N'-phenylparaphenylenediamine or phosphites, for example tris (nonylphenyl) phosphite. It is also possible to use other commercially available stabilizers.

-13 Polymers are isolated by evaporation to increase the concentration of the polymer solution, by precipitation with a non-solvent substance such as methanol, ethanol or acetone, or preferably by steam distillation of the solvent.

After steam separation, the water is removed by using appropriate sieve assemblies or appropriate screw assemblies, for example, extractor screws or expander screws or fluidized bed drying devices.

The drying process uses conventional methods, for example, in a drying oven or in a screw conveyor belt drying device.

The Mooney viscosity (ML 1 + 4 at 100 ° C) of high molecular weight polybutadiene produced by the claimed method is at least 50% higher after step 3) than the Mooney viscosity of the polybutadiene after the stage two).

It is preferable that the Mooney viscosity of the claimed high molecular weight polybutadiene (NdBR) is at least 20 MU (ML 1 + 4 at 100 ° C), preferably 20 to 25 MU (ML 1 + 4 at 100 ° C) , particularly preferably at least 40 MU (ML 1+ 4 at 100 ° C), and that after the addition of sulfur chlorides, such as diazufre dichloride, sulfur dichloride and / or thionyl chloride, its viscosity of Final Mooney is at least 30 MU (ML 1 + 4 at 100 ° C), preferably from 40 to 50 MU (ML 1 + 4 at 100 ° C), particularly preferably from 60 to 80 MU (ML 1 + 4 at 100 ° C), without gel formation or with significantly reduced gel formation.

-14 Preferably, the gel content is less than 1% by weight.

The initial Mooney viscosity refers to the Mooney viscosity of polybutadiene after the polymerization process.

It is also possible to determine the gradual increase in Mooney's value through the use of Mooney stress relaxation in accordance with ASTM D1646-00 (MSR). In this case, the MSR values ​​are measured after stage 2) and stage 3). The ratio calculated from MSR (2) and MSR (3) provides the modification coefficient. The MSR value is measured at 100 ° C according to the conventional method of ASTM D1646-00.

The modified coefficient of modified polybutadiene is preferably 1.3 to 2.5, preferably 1.4 to 2.1.

The invention also comprises a high molecular weight neodymium catalyzed polybutadiene which can be obtained by means of the claimed method.

It is preferable that the high molecular weight neodymium catalyst polybutadiene claimed comprises carboxylic acid, fatty acid and / or fatty acid ester. In particular, animal or vegetable fatty acids esters, saturated or mono- or polyunsaturated, natural or modified, in particular epoxidized soybean oil, or versatic acid, octanoic acid, isooctanoic acid, lauric acid, myristic acid, palmitic acid or oleic acid in the claimed neodymium polybutadiene. The person skilled in the art is aware of conventional detection methods, for example using thin layer chromatography, gas chromatography, HPLC or mass spectroscopy; prior extraction / acid isolation

-15 carboxylic acid, fatty acid and / or fatty acid esters is optional.

The claimed high molecular weight neodymium catalyzed polybutadiene does not require additions of expander oils, for example aromatic expander oils, in order to adjust the Mooney viscosity of the rubbers.

Polybutadienes can be used alone, in a mixture with aliphatic or aromatic oils or in a mixture with other rubbers. Additional rubbers suitable for producing 10 vulcanized rubber are not only natural rubber but also synthetic rubbers. Preferred synthetic rubbers are described by way of example in W. Hofmann, Kautschuktechnologie, Genter Verlag, Stuttgart 1980 and I. Fanta, Elastomers and Rubber Compounding Materials, Elsevier, 15 Amsterdam 1989. They understand, among others

BR - conventional polybutadiene

ABR - butadiene / alkyl acrylate copolymers

C1-C4

CR - polychloroprene

IR - polyisoprene

SBR - styrene / butadiene copolymers having styrene contents of 1 to 60% by weight, preferably 20 to 50% by weight

IIR - isobutylene / isoprene copolymers

NBR - butadiene / acrylonitrile copolymers with acrylonitrile contents of 5 to 60% by weight, preferably 10 to 40% by weight

HNBR - partially or completely hydrogenated NBR rubber

-16EPDM

- ethylene / propylene / diene copolymers and also mixtures for the production of tires for motor vehicles with the help of modified surface loads are in particular natural rubber,

Emulsion SBR, and also dissolution SRR rubbers with a glass transition temperature above -50 ° C, optionally modified with silyl ethers or other functional groups, as described in EP-A-0 447 066 , polybutadiene rubber having a high content of 1,4-cis (> 90% by weight) produced with catalysts based on Ni, Co, Ti or Nd, and also polybutadiene rubber having 0 to 75% in vinyl content weight, and also mixtures of these.

Rubber mixtures are also provided by means of the invention and generally comprise from 5 to 300 parts by weight of an active or inert filler, for example silica in the form of fine particles, produced for example by precipitation from solutions of silicates, flame hydrolysis or silicon halides with specific surface areas of 5 to 1000 m²/ g, preferably 20 to 40 m²/ g (BET surface area) and with main particle sizes from 10 to 400 nm. Silicas may, if appropriate, also take the form of mixed oxides with other metal oxides, such as oxides of Al, Mg, Ca, Ba, Zn, Zr or Ti, synthetic silicates, such as aluminum silicate, or silicate of ferrous alkali metal, such as magnesium silicate or calcium silicate, with BET surface areas of 20 to 400 m²/ g main particle diameters from 10 to 400 nm,

-17 natural silicates, such as kaolin and any other form of naturally occurring silica, glass fibers and fiberglass products (meshes, strands), or glass micro-beads, metal oxides, such as zinc oxide, oxide calcium, magnesium oxide, aluminum oxide, metal carbonates, such as magnesium carbonate, calcium carbonate, zinc carbonate, metal hydroxides, for example, aluminum hydroxide, magnesium hydroxide, metal salts, for example zinc or magnesium salts of fatty acids [alpha], [beta] -unsaturated, for example, acrylic or methacrylic acid, having 3 to 8 carbon atoms, examples being zinc acrylate, zinc diacrylate, methacrylate zinc, zinc dimethacrylate and mixtures thereof;

carbon blacks The carbon blacks to be used in this case are those produced through carbon black processes, furnace black processes or gas black processes, and which have BET surface areas of 20 to 200 m²/ g, examples being carbon black SAF, ISAF, HAF, FEF or GPG.

rubber gels, in particular those based on polybutadiene, butadiene / styrene copolymers, butadiene / acrylonitrile copolymers and polychloroprene.

Particular preference is given to zinc diacrylates, fine particle silicas and carbon blacks.

The mentioned loads can be used alone or in the form of a mixture. In a particularly preferred embodiment, the rubber mixtures comprise, as fillers, a mixture of pale-colored fillers, for example silica with particles

-18 fine, and carbon black, in which the proportion of pale-colored fillers relative to carbon blacks in the mixture is 0.05 to 20, preferably 0.1 to 10.

The form in which the charges are added to the claimed polybutadiene solution (s) is preferably that of solids or suspension in water or in a solvent. The rubber solution can be produced in advance, but it is preferable to directly use the solution from the polymerization reaction.

Subsequently, be the solvent or preferably with the help of steam.

The conditions for said separation process can easily be determined through preliminary experimentation.

Preference is given to the addition of the fillers to the solid polybutadiene or a mixture of rubbers, and to the incorporation by means of mixing in a known manner, for example, by the use of a kneader.

The claimed rubber mixtures also comprise crosslinking agents, if appropriate. The crosslinking agents used may comprise sulfur or peroxides, and sulfur herein is particularly preferred. The rubber mixtures according to the invention may further comprise rubber auxiliary substances, such as reaction accelerators, antioxidants, thermal stabilizers, light stabilizers, anti-ozonants, processing aids, plasticizers, adhesives, blowing agents, dyes, pigments, waxes, expanders, organic acids, retarding agents, metal oxides and also activators, for example triethanolamine, polyethylene glycol, hexanotriol, etc., these being known in the rubber industry.

ϊ

-19 In preferred rubber mixtures using high activity precipitated silicas, it is particularly advantageous to use additional charge activators. Additional charge activators are sulfur-containing silyl ethers, in particular bis (trialkoxysilylalkyl) polysulfides, as described herein.

DE-A-2,141,159 and DE-A-2,255,577, oligomeric and / or polymeric silyl ethers containing sulfur from DE-A-4,435,311 and EP-A-0 670 347, and mercaptoalkyltrialkoxysilanes, in particular mercaptopropyltriethoxysilane and thiocyanatoalkyl silyl ether, for example, as described in DE-A195 44 469.

The quantities used of the auxiliary materials are normal quantities, and depend, among others, on the intended use. Examples of normal amounts are amounts from 0.1 to 50% by weight, based on rubber.

Further mixing of the rubbers with the other auxiliary products mentioned, crosslinking agents and accelerators can be carried out normally with the aid of appropriate mixing assemblies, such as rollers, internal mixers and mixing extrusion devices.

Vulcanization and compound formation processes are described in more detail by way of example in Encyclopedia of Polymer Science and Engineering, Vol 4, pp. 66 ff (compound formation) and Vol. 17, pp 666 ff (vulcanization).

The rubber mixtures according to the invention can be vulcanized at normal temperatures of 100 to 200 ° C, preferably 130 to 180 ° C (if appropriate at

-20 pressure from 10 to 200 bar).

The rubber mixtures claimed have excellent suitability for producing molds of any type.

Non-limiting examples of said molding are 0-rings, profiles, joints, membranes, tires, tire treads, damping elements and flexible tubes.

Particular preference is given to various tire components and tire treads.

The rubber mixtures according to the invention are also suitable for impact modification thermoplastics, in particular for polystyrene and styrene / acrylonitrile copolymers.

Rubber blends are used particularly well for golf balls, in particular golf ball cores.

The scope of the invention encompasses combinations of all remaining definitions, indices, parameters and explanations provided above and listed hereinafter in general terms or at preferred intervals, that is, it also encompasses any desired combination that involves the respective intervals and intervals. preferred.

The following examples are used for further explanation of the invention.

I. Production of high molecular weight neodymium catalyzed polybutadienes (NdBR)

Several NdBRs were produced with a stepwise molecular weight increase.

Comparative Example 1: NdBR with a small gradual increase &lt;

% of Mooney value, without gel formation ϊ

-21 Polymerization process:

8500 g of hexane (dried on a molecular sieve), 1300 g of 1,3-butadiene, 21.4 mmol of a 20% solution of diisobutylaluminum hydride in hexane, 1.44 mmol of a 10% solution were introduced of ethylaluminum sesquichloride in hexane, and 1.44 mmol of a 40% solution of neodymium versatate in hexane, in a 20 1 steel autoclave inertized with nitrogen and dried. The system was heated to 73 ° C, with stirring and the mixture was polymerized for 60 minutes, with stirring. A conversion sample was taken. The conversion of butadiene after the polymerization process was 99.7%.

The polymerization process was terminated by adding 3.75 g of stearic acid (0.25 phr) and 1.3 g of Irganox 1520 (0.1 phr) were used for stabilization. The solution was maintained at 65 ° C for another 15 minutes.

Initial Mooney Viscosity (ML 1 + 4 at 100 ° C): 39 MU Mooney Tension Relaxation (MSR at 100 ° C according to ASTM D1646-00): MSR (2) = 0.64.

Modification:

720 g of polymer solution was transferred to a 2 1 glass reactor. For the modification process, 1.7 g of a diazufre dichloride solution (11% concentration (0.2 phr)) was added. The solution was stirred at ° C for 15 minutes. The polymer was precipitated by introduction into 5 kg of ethanol, stabilized with Irganox 1520 (0.2 phr) and dried under vacuum at 70 ° C. Weight after drying: 95 g.

Mooney Final Viscosity (ML 1 + 4 at 100 ° C): 44 MU Mooney Stress Relaxation MSR (3) = 0.52;

-22 Gel content &lt;0.3% by weight

Microstructure: 97.5% by weight of 1,4-cis; 1.7% by weight of

1,4-trans; 0.8% by weight of 1,2-vinyl.

High molecular weight neodymium catalyzed polybutadiene does not exhibit gel formation, with a small stepwise increase in the Mooney value of 12.8% above the initial Mooney viscosity.

The modification coefficient (MC) is 1.2.

Comparative Example 2: NdBR with a high stepwise increase in Mooney value> 50% with gel formation

Polymerization process:

8500 g of hexane (dried on a molecular sieve), 1300 g of 1,3-butadiene, 21.3 mmol of a 20% solution of diisobutylaluminium hydride in hexane, 1.44 mmol of a 10% solution were introduced of ethylaluminum sesquichloride in hexane, and 1.44 mmol of a 40% solution of neodymium versatate in hexane, in a 20 1 steel autoclave inertized with nitrogen and dried. The system was heated to 73 ° C, with stirring and the mixture was polymerized for 60 minutes, with stirring. A conversion sample was taken. The conversion of butadiene after the polymerization process was 99.7%.

The polymerization process was terminated by adding 6.5 g of stearic acid. The solution was maintained at 65 ° C for another 15 minutes.

Initial Mooney Viscosity (ML 1 + 4 at 100 ° C): 36 MU

MSR (2) = 0.77.

Modification:

720 g of polymer solution was transferred to a 2 1 glass reactor. For the modification process,

-23 added 3.42 g of a solution of diazufre dichloride (concentration of 11% (0.4 phr)). The solution was stirred at ° C for 15 minutes. The polymer was precipitated by introduction into 5 kg of ethanol, stabilized with Irganox 1520 (0.2 phr) and dried under vacuum at 70 ° C. Weight after drying: 95 g.

Mooney Final Viscosity (ML 1 + 4 at 100 ° C): 82 MU;

MSR (3) = 0.35;

Gel content 8.5% by weight

Microstructure: 97.6% by weight of 1,4-cis; 1.7% by weight of

1,4-trans; 0.7% by weight of 1,2-vinyl.

The high molecular weight neodymium catalyzed polybutadiene exhibits gel formation in an amount of 8.5% by weight, with a large stepwise increase in the Mooney value of 127.8% above the initial viscosity of

Mooney

Therefore, the modification coefficient is 2.2.

Example of Invention 1: NdBR with a high stepwise increase in Mooney value of 83% without gel formation

Polymerization process:

8500 g of hexane (dried on a molecular sieve), 1300 g of 1,3-butadiene, 29.2 mmol of a 20% solution of diisobutylaluminium hydride in hexane, 1.44 mmol of a 10% solution were introduced of ethylaluminum sesquichloride in hexane, and 1.44 mmol of a 40% solution of neodymium versatate in hexane, in a 20 1 steel autoclave inertized with nitrogen and dried. The system was heated to 73 ° C, with stirring and the mixture was polymerized for 60 minutes, with stirring. A conversion sample was taken. Butadiene conversion after the process of

-24 polymerization was 99.5%.

The polymerization process was terminated by adding 5.5 g of stearic acid (0.5 phr). The solution was maintained at 65 ° C for another 15 minutes.

Initial Mooney Viscosity (ML 1 + 4 at 100 ° C): 24 MU MSR (2) = 0.78.

Modification:

720 g of polymer solution was transferred to a 2 1 glass reactor. For the modification process, 1.24 g of a solution of diazufre dichloride in ESBO (concentration of 54% (0.7 phr)) was added. The solution was stirred at 65 ° C for 15 minutes. The polymer was precipitated by introduction into 5 kg of ethanol, stabilized with Irganox 1520 (0.2 phr) and dried under vacuum at ° C. Weight after drying: 95.2 g.

Mooney Final Viscosity (ML 1 + 4 at 100 ° C): 44 MU;

MSR (3) = 0.46;

Gel content &lt;0.3% by weight

Microstructure: 97.4% by weight of 1,4-cis; 1.9% by weight of

1,4-trans; 0.6% by weight of 1,2-vinyl.

Therefore, the modification coefficient is 1.7.

Example of Invention 2: NdBR with a high stepwise increase in Mooney value of 55% without gel formation

Polymerization process:

8500 g of hexane (dried on a molecular sieve), 1300 g of 1,3-butadiene, 21 mmol of a 20% solution of diisobutylaluminium hydride in hexane, 1.44 mmol of a 10% sesquichloride solution were introduced of ethyl aluminum in hexane, and 1.44 mmol of a solution of% neodymium versatate in hexane, in an autoclave of

-25 steel of 1 inertized with nitrogen and dry. The system was heated to 73 ° C, with stirring and the mixture was polymerized for 60 minutes, with stirring. A conversion sample was taken. The conversion of butadiene after the polymerization process was 98.7%.

The polymerization process was terminated by adding 6.5 g of stearic acid (0.5 phr). The solution was maintained at 65 ° C for another 15 minutes.

Initial Mooney Viscosity (ML 1 + 4 at 100 ° C): 40 MU MSR (2) = 0.65.

Modification:

720 g of polymer solution was transferred to a 2 1 glass reactor. For the modification process, 0.40 g of a solution of diazufre dichloride in ESBO (concentration of 64% (0.3 phr)) was added. The solution was stirred at 65 ° C for 15 minutes. The polymer was precipitated by introduction into 5 kg of ethanol, stabilized with Irganox 1520 (3.2 phr) and dried under vacuum at ° C. Weight after drying: 95.1 g.

Mooney Final Viscosity (ML 1 + 4 at 100 ° C): 62 MU;

MSR (3) = 0.36;

Gel content &lt;0.3% by weight

Microstructure: 97.4% by weight of 1,4-cis; 2.0% by weight of

1,4-trans; 0.6% by weight of 1,2-vinyl.

Molar mass: Mn = 202 kg / mol, Mw = 418 kg / mol, Mz = 1050 kg / mol; polydispersity (Mw / Mn) = 2.07.

Viscosity of the solution: 218 mPas.

Therefore, the modification coefficient is 1.8.

Example of Invention 3: NdBR with a high stepwise increase in Mooney value of 97% without gel formation

-26 Polymerization process:

8500 g of hexane (dried on a molecular sieve), 1300 g of 1,3-butadiene, 21 mmol of a 20% solution of diisobutylaluminium hydride in hexane, 1.44 mmol of a 10% sesquichloride solution were introduced of ethylaluminum in hexane, and 1.44 mmol of a 40% solution of neodymium versatate in hexane, in a 20 1 steel autoclave inertized with nitrogen and dried. The system was heated to 73 ° C, with stirring and the mixture was polymerized for 60 minutes, with stirring. A conversion sample was taken. The conversion of butadiene after the polymerization process was 99.5%. The polymerization solution was not terminated and processed directly afterwards. A polymer sample was taken and the Mooney value of the polymer was determined.

Initial Mooney Viscosity (ML 1 + 4 at 100 ° C): 37 MU

MSR (2) = 0.65.

Modification:

720 g of polymer solution was transferred to a 2 1 glass reactor. For the modification process, 0.76 g of a solution of diazufre dichloride in ESBO was added (concentration of 37.5% (0.3 phr) ). The solution was stirred at 65 ° C for 15 minutes. The polymer was precipitated by introduction into 5 kg of ethanol, stabilized with Irganox 1520 (0.2 phr) and dried under vacuum at ° C. Weight after drying: 95.1 g.

Mooney Final Viscosity (ML 1 + 4 at 100 ° C): 73 MU;

MSR (3) = 0.33;

Gel content &lt;0.3% by weight

Microstructure: 97.7% by weight of 1,4-cis; 1.7% by weight of

-271,4-trans; 0.6% by weight of 1,2-vinyl.

The modification coefficient (MC) is 1.97.

All NdBRs produced by the claimed method exhibit a large stepwise increase in Mooney's value. The final Mooney viscosity is more than 50% above the initial Mooney viscosity of the NdBR with a gel content &lt;0.3% by weight.

Test:

A. Determination of the content of polybutadiene gel in styrene by means of a gravimetric method based on the BAYELAS MO AQ 259 - A LAB method:

25.0 g of polymer were weighed with an accuracy of 0.1 g on a laboratory scale. The edges were cut and discarded before the procedure. The polymer is cut into small pieces. 850 ml of filtered styrene is introduced into a 1 1 wide neck bottle, and the polymer is dissolved in approximately 4 hours on a shaker.

The wire net formed by a wire fabric with a mesh width of 0.036 mm, 50 mm diameter, heated to red before the procedure, is cooled in a desiccant bottle. After cooling, the wire net is removed from the desiccant bottle and accurately weighed 0.1 mg on an analytical balance. This provides weight A. 100 ml of filtered styrene is provided in each of the three glass beakers. The 50 mm diameter wire net is placed in the Gelman metal filtration system (sealed-filter-sealed) and the connection to the funnel is threaded in place.

The polymer solution is now poured through the filter.

The first of the three glass beakers is used

-28 containing styrene to rinse the wide neck bottle and this solution is passed through the filter in this way. Subsequently, the other two parts are used to rinse the filter.

Then, the filter is carefully removed with tweezers and placed on a clean paper. Pressure is carefully applied with the tweezers on the edge of the filter. A lens is used to observe the evaporation of styrene. The wet wire filter, still moistened with styrene, becomes visibly paler as the amount of styrene decreases. Once all filter meshes are free of styrene, it is immediately weighed again into the balance. This provides weight B.

After the second filter weighing, it is dried in a drying cabinet for 15 minutes at 100 ° C (± 5 ° C) in order to determine the dry gel content. In this case, the filter is in an open desiccant bottle. After drying, the bottle together with the filter are placed in a desiccator for approximately 10 minutes and subsequently reweighed. This provides weight C.

Calculations

Wet gel = (B - A) ★ 10⁶ [ppm]

Dry gel = (C - A) * 10⁶ [ppm] swelling index = ____ Wet Gel [dimensionless]

Dry gel

-29B: Mooney viscosity and Mooney strain relaxation according to ASTM D1646-00

C: Viscosity of the solution according to ISO 3105:

A Brookfield DV-I rotary viscometer is used to measure the viscosity of a polymer solution of 5.43% in toluene at room temperature.

D: GPC was carried out by Currenta.

E: Determination of microstructure.

Currenta, ELA 101: A polymer solution in toluene is placed in a KBr window, the solvent is evaporated, and the polymer film is studied by means of FTIR spectroscopy between 2 KBr windows.

ESBO: Cognis epoxidized soybean oil

Irganox 1520: 4,6-bis (octylthiomethyl) -o-cresol from BASF.

II. Production of rubber and vulcanized mixtures

Comparative Example 2 is not suitable for a compound test due to the very high gel content.

Rubber mixtures comprising BUNATM CB 22 were produced in the form of Nd-catalyzed polybutadiene without gradual increase in Mooney's value, and also the polymer of Comparative Example 1 and the polymer claimed from Example of Invention 2. Table 2 lists the constituents of the mixture. Initially the mixtures were produced in a 1.5 1 mixer without sulfur or accelerator. Subsequently, the constituents of the sulfur and accelerator mixture were mixed at 40 ° C in a roller.

The initial Mooney viscosity of NdBR of Comparative Example 1 is 39 MU; The initial Mooney viscosity of NdBR claimed from the Example of Invention 2 is 39 MU. The Mooney viscosity of Buna CB22 without gradual increase of

-30 Mooney value is 63 MU.

The substances used for the mixing studies were the following:

Table 1:

Table 1

<td>Tradename .....</td><td>Producer</td>

<td>BUNA ™ CB 22 as Nd polybutadiene</td><td>Lanxess Deutschland GmbH</td>

<td>CORAX N 326 as black from carbon</td><td>Evonik Degussa GmbH</td>

<td>VIVATEC 500 as oil</td><td>Hansen und Rosenthal KG</td>

<td>ZINKWEIL ROTSIEGEL as oxide zinc</td><td>Cricket Zinkoxid GmbH</td>

<td>EDENOR C 18 98-100 as acid stearic</td><td>Caldic Deutschland GmbH</td>

<td>VULKANOX 4020 / LG as stabilizer</td><td>Lanxess Deutschland GmbH</td>

<td>VULKANOX HS / LG as stabilizer</td><td>Lanxess Deutschland GmbH</td>

<td>VULKACIT® CZ / EGC as throttle</td><td>Lanxess Deutschland GmbH</td>

<td>RHENOGRAN IS 60-75 as sulfur</td><td>RheinChemie Rheinau GmbH</td>

<td>TSR / RSS 3 DEFO 700</td><td>Natural rubber Defo 700</td>

Table 2: Constitution of the mixtures

<td>NdBR</td><td>CE1</td><td>IE2</td><td>CE2</td><td>CE1 *</td><td>IE2 *</td><td>CE2 *</td>

<td>Example Comparative 1</td><td> 100</td><td></td><td></td><td> 70</td><td></td><td></td>

ϊ

I IVI UI

..............................................., ο

<td>Example Invention</td><td>from two</td><td>the</td><td></td><td> 100</td><td></td><td></td><td> 70</td><td></td>

<td colspan="3">Buna CB 22</td><td></td><td></td><td> 100</td><td></td><td></td><td> 70</td>

<td>TSR / RSS 700</td><td> 3</td><td>DEFO</td><td></td><td></td><td></td><td> 30</td><td> 30</td><td> 30</td>

<td colspan="3">CORAX N 326</td><td> 50</td><td> 50</td><td> 50</td><td> 50</td><td> 50</td><td> 50</td>

<td colspan="3">VIVATEC 500</td><td> 4</td><td> 4</td><td> 4</td><td> 4</td><td> 4</td><td> 4</td>

<td colspan="3">ZINKWEISS ROTSIEGEL</td><td> 2</td><td> 2</td><td> 2</td><td> 2</td><td> 2</td><td> 2</td>

<td>EDENOR C 100</td><td> 18</td><td> 98-</td><td> 3</td><td> 3</td><td> 3</td><td> 3</td><td> 3</td><td> 3</td>

<td>VULKANOX</td><td colspan="2">4020 / LG</td><td> 2</td><td> 2</td><td> 2</td><td> 2</td><td> 2</td><td> 2</td>

<td>VULKANOX</td><td colspan="2">HS / LG</td><td> 3</td><td> 3</td><td> 3</td><td> 3</td><td> 3</td><td> 3</td>

<td>VULKACIT</td><td colspan="2">CZ / EGC</td><td> 1,4</td><td> 1,4</td><td> 1,4</td><td> 1,4</td><td> 1,4</td><td> 1,4</td>

<td>RHENOGRAN 75</td><td>IS</td><td> 60-</td><td> 2,36</td><td> 2,36</td><td> 2, 36</td><td> 2,36</td><td> 2,36</td><td> 2,36</td>

For the evaluation of the ability of compound formation, ground sheets were evaluated before and after mixing to incorporate the rubber chemicals. The 5 mixtures CE1 and CE1 *, and also IE2 and IE2 * according to the invention exhibited soft milled sheets, while the mixtures CE2 and CE2 * with unmodified Buna CB22 exhibited in-homogeneous ground sheets with severe bagging and improper contact with the roller

The following properties of the vulcanizates were determined according to the commented patterns:

DIN 53505: Shore A hardness at 23 ° C and 70 ° C

DIN 53512: rebound resilience at 23 ° C and 70 ° C (R23)

-32DIN 53504: tension values ​​at 10%, 25%, 50%, 100%, 200% and 300% stretch (σιο, Π25, aso, σιοο, 0200 and disgust), tensile strength and stretch until breakage . DIN 53516: abrasion value

The Eplexor (Eplexor 500 N) equipment from Gabo-Testanlagen GmbH, Ahlden, Germany was used to determine the dynamic properties (temperature dependence of the storage module E 'in the temperature range of -60 ° C to 0 ° C, and also so δ at 60 ° C). Values ​​according to DIN 53513 at 10 Hz were determined in cylindrical samples in the temperature range of -100 ° C to + 100 ° C at a heating rate of 1 K / minute. Measurements were carried out in comparison mode with static compression of 1% and dynamic deformation of 0.1%.

<td>I know</td><td>Use the</td><td>method for</td><td>get the</td><td>following variables,</td>

<td>it is</td><td>tando la</td><td>terminology</td><td>in this case</td><td>in accordance with ASTM</td>

<td colspan="2">D5992-96.</td><td></td><td></td><td></td>

<td>AND'</td><td>(-60 ° C):</td><td>module</td><td>storage</td><td>at -60 ° C</td>

<td>AND'</td><td>(-50 ° C):</td><td>module</td><td>storage</td><td>-50 ° C</td>

<td>AND'</td><td>(-40 ° C):</td><td>module</td><td>storage</td><td>-40 ° C</td>

<td>AND'</td><td>(-30 ° C):</td><td>module</td><td>storage</td><td>-30 ° C</td>

<td>AND'</td><td>(-20 ° C):</td><td>module</td><td>storage</td><td>-20 ° C</td>

<td>AND'</td><td>(-10 ° C):</td><td>module</td><td>storage</td><td>-10 ° C</td>

<td>AND'</td><td>(0 ° C):</td><td>module</td><td>storage</td><td>0 ° C,</td>

<td>Y</td><td>too</td><td></td><td></td><td></td>

tan δ (60 ° C): loss factor (E '' / E ') at 60 ° C.

E 'provides an indication of the tread grip of a winter tire on ice and snow. As E 'decreases, the grip increases.

-33tan δ (60 ° C) is a measure of hysteresis loss from the tire under operating conditions. As so δ (60 ° C) decreases, the rolling resistance of the tire decreases.

Table 3 shows the vulcanizing properties of the mixtures.

Table 3: Vulcanized Properties

<td></td><td colspan="2"></td><td>ΞΕ2</td><td>CE2</td><td>CE1 *</td><td>IE2 *</td><td>CS2 *</td>

<td>Test</td><td>Unit</td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>ML 1 + 4/100</td><td>MU</td><td> 49, 7</td><td> 59, 0</td><td> 75, 1</td><td> 50,5</td><td> 56, 9</td><td> 68,7</td>

<td>ShA hardness at 23 ° C</td><td></td><td> 59, 5</td><td> 60, 4</td><td> 61, 6</td><td> 58,0</td><td> 59, 1</td><td> 60,3</td>

<td colspan="2">Traction stretch</td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>S10 at 23 ° C</td><td>MPa</td><td> 0,5</td><td> 0,5</td><td> 0,6</td><td> 0,5</td><td> 0,5</td><td> 0,5</td>

<td>S300 at 23 ° C</td><td>MPa</td><td> 7,3</td><td> 8,5</td><td> 8,3</td><td> 8,3</td><td> 8,9</td><td> 8,6</td>

<td>S300 / S10</td><td></td><td> 14,6</td><td> 17</td><td> 13, 8</td><td> 16, 6</td><td> 17,8</td><td> 17,2</td>

<td>Amplitude deviation 60 ° C</td><td>MTS to</td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>G * (0.5%) first measurement</td><td></td><td> 1,91</td><td> 1,89</td><td> 1,91</td><td> 1,94</td><td> 1,88</td><td> 1, 98</td>

<td>G * (15%) first measurement</td><td></td><td> 1,16</td><td> 1,19</td><td> 1,22</td><td> 1,12</td><td> 1,12</td><td> 1, 19</td>

<td>Tan d maximum</td><td></td><td> 0,13</td><td> 0,12 1</td><td> 0,11 6</td><td> 0,13 7</td><td> 0,12 2</td><td> 0,11 9</td>

<td>Bounce Resilience</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>at 60 ° C</td><td>Or</td><td> 63, 3</td><td> 64,6</td><td> 65, 7</td><td> 61, 8</td><td> 63,3</td><td> 62,0</td>

<td colspan="2">Dynamic damping, DIN 53513</td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>E '(0 ° C)</td><td>MPa</td><td> 10, 3 7</td><td> 9,43</td><td> 9,34</td><td> 12,4 2</td><td> 10, 6 7</td><td> 12,5 4</td>

<td></td><td></td><td></td><td>CE1</td><td>IE2</td><td>CE-2</td><td>CE1 *</td><td>IE2 *</td><td>C '⁰*</td>

<td>E '</td><td>(23 ° C)</td><td>MPa</td><td> 9,2</td><td> 8,47</td><td> 8,43</td><td> 10,7</td><td> 9,3</td><td> 10, 9 2</td>

<td>AND'</td><td>(60 ° C)</td><td>MPa</td><td> 8,34</td><td> 7,83</td><td> 7,85</td><td> 9,19</td><td> 8,19</td><td> 9,56</td>

<td>E '' &lt;</td><td>&gt; (0 ° C)</td><td>MPa</td><td> 0,87</td><td> 0,74</td><td> 0,63</td><td> 1,17</td><td> 0,94</td><td> 1, 09</td>

<td>E ''</td><td>(23 ° C)</td><td>MPa</td><td> 0,67</td><td> 0,57</td><td> 0,49</td><td> 0,83</td><td> 0,67</td><td> 0,78</td>

<td>E ''</td><td>(60 ° C)</td><td>MPa</td><td> 0,55</td><td> 0,44</td><td> 0,34</td><td> 0,59</td><td> 0,47</td><td> 0,54</td>

<td>E * (</td><td>0 ° C)</td><td>MPa</td><td> 10, 4 1</td><td> 9,46</td><td> 9,36</td><td> 12,4 7</td><td> 10,7 1</td><td> 12,5 9</td>

<td>AND*</td><td>(23 ° C)</td><td>MPa</td><td> 9,22</td><td> 8,49</td><td> 8,44</td><td> 10,7 3</td><td> 9,33</td><td> 10,9 5</td>

<td>AND*</td><td>(60 ° C)</td><td>MPa</td><td> 8,36</td><td> 7,84</td><td> 7,86</td><td> 9,21</td><td> 8,21</td><td> 9, 58</td>

<td>so</td><td>d (0 ° C)</td><td></td><td> 0,08 5</td><td> 0,08</td><td> 0,06 8</td><td> 0,09 5</td><td> 0,08 9</td><td> 0,08 8</td>

<td>so</td><td>d (23 ° C)</td><td></td><td> 0,07 3</td><td> 0,06 8</td><td> 0,05 9</td><td> 0,07 8</td><td> 0,07 3</td><td> 0,07 2</td>

<td>so</td><td>d (60 ° C)</td><td></td><td> 0,06 7</td><td> 0,05 8</td><td> 0,04 5</td><td> 0,06 5</td><td> 0,05 8</td><td> 0,05 8</td>

<td colspan="3">Abrasion, DIN 53516</td><td></td><td></td><td></td><td></td><td></td><td></td>

<td colspan="2">Abrasion value</td><td>mm³</td><td> 13</td><td> 12</td><td> 15</td><td> 29</td><td> 29</td><td> 33</td>

In comparison with Comparative Examples CE1 and CE1 *, IE2 and IE2 * according to the invention exhibit a marked improvement of the indicators for low rolling resistance, 5 for example high rebound resilience at 60 ° C, low value of maximum delta tangent in the MTS test at 60 ° C and low delta tangent value at 60 ° C in the Eplexor test, better results in the tensile stretch test, discernible from a large S300 / S10 ratio, and also very

-35good values ​​in the abrasion test.

Compared to the unmodified Buna CB22 of Comparative Examples CE2 and CE2 *, Examples of the Invention IE2 and IE2 * exhibit a marked improvement in the processing quality, discernible of a homogeneously smooth smooth sheet appreciably and a subject fraction Garvey extrusion completely satisfactory, while the properties of the compounds are comparatively good.

Description of the Figures of the Invention

Figure 1 shows the Garvey extrusion fractions of Comparative Example CE1, Example of Invention IE2 and Comparative Example CE2 (from the top to the bottom) at 90 ° C and a rotation rate of 50 rpm.

CE1 and IE2 provide smooth extruded fractions, while CE2 has a different sawtooth profile.

Above all, it has been found that the claimed polymers with a large stepwise increase of Mooney value of> 50% can be used to produce mixtures that are easy to process and provide smooth extrusion fractions, but which in terms of properties Physical compounds are equivalent to unmodified neodymium catalyzed polybutadiene rubbers that are difficult to process.