WO2003044065A2

WO2003044065A2 - Microstructure modifier for anionic polymerization

Info

Publication number: WO2003044065A2
Application number: PCT/EP2002/012687
Authority: WO
Inventors: Walter Hellermann
Original assignee: Walter Hellermann
Priority date: 2001-11-23
Filing date: 2002-11-13
Publication date: 2003-05-30
Also published as: WO2003044065A3; EP1453869A2; AU2002358503A1; AU2002358503A8

Abstract

Disclosed is a method for the production of optionally coupled, non-blocking polymers based on conjugated dienes and optionally monovinyl aromatic compounds by anionic polmerization in an inert organic solvent in the presence of a lithium organic compound as an initiator and a microstructure modifier and/or randomizer. Specific ether compounds are used as a microstructure modifier and/or randomizer. The polymers thus produced are particularly suitable for the production of damping material, tires and tire components (e.g. tire treads or tire sidewalls) and technical rubber articles.

Description

Microstructure regulator for anionic polymerization I

The present invention relates to a process for the preparation of optionally coupled, non-blocking polymers based on conjugated dienes and optionally monovinylaromatic compounds by anionic polymerization, in particular at high temperatures, and to the process products or polymers prepared in this way and their use, in particular for the preparation of Tires and tire components as well as damping elements.

The development of tires with a perfected property profile represents a complex optimization task in which the tire manufacturer moves in the area of tension between the magic triangle of rolling resistance, abrasion resistance and wet skid resistance. In order to improve the wet skid behavior, it is necessary to manufacture tire rubbers with the highest possible glass temperature, as is the case, for. B. with the 3,4-polyisoprene rubber. In the case of the modern solution SBR rubbers, this leads to tire polymers with the highest possible 1,2-vinyl units and 3,4 structural units. At the same time, the trend in anionically produced butadiene / styrene rubbers is towards higher styrene contents of more than 25%, based on the entire polymer. As a result, the requirements for the randomizer effect of the microsliic controller used increase significantly.

Basic polar compounds, so-called microstructure regulators, are used in modern solution polymers to adjust these tailor-made microstructures both for the homopolymerization and for the copolymerization of dienes and vinyl aromatics.

The microstructure regulators of the prior art have the disadvantage that their efficiency is significantly reduced at high polymerization temperatures. Furthermore, in most cases they have only a weak influence on the statistical incorporation of the vinyl aromatic component, ie there is a poor randomizer effect. For the purposes of the present invention, the term microstructure regulator includes, in particular, a multidentate Lewis base which, in addition to the microstructure, also specifically controls the statistical incorporation of vinylaromatic compounds - usually styrene - at the same time; ie a good randomizer effect is also achieved at the same time. For further details, reference can be made, for example, to H. Koch, W. Adametz "Microstructure Regulators for Custom-Made Solution Rubbers", GAK 3/2002, Volume 55, pages 162 to 166.

Numerous compounds are known from the prior art which influence the course of the polymerization with regard to the preferred formation of 1,2- and 3,4-structural units (cf. KH Nordsiek, KM Kiepert, caoutchouc and rubber, plastics 35 , 371 (1982) and KH Nordsiek, caoutchouc and rubber, plastics 39, 599 (1986).

In the past, numerous ethers, amines, phosphines, etc. have been proposed as microstructure regulators (DE-PS 27 07 761 and 31 15 878). However, since these substances alone do not have a satisfactory randomizing effect, surface-active agents must also be used for the statistical incorporation of the monomers in the polymer molecule.

EP-A-0 304 589 describes certain ethylene glycol dialkyl ethers as suitable microstructure regulators. However, these compounds show a significant drop in the microstructure control action at higher polymerization temperatures and, moreover, do not have an optimal randomizer action. A major disadvantage of the microstructure regulators of the prior art is the often weakening regulating action when the polymerization temperature rises. It is known, for example, that with the frequently used microstructure regulator tetramethylethylenediamine (TMEDA) in isoprene polymerization with a molar ratio of molecular structure regulator / initiator of about 5 high levels of 3,4-structural units, but at the same time the polymerization rate drops significantly (cf.WL Hsu, AF Halasa and TT Wetli, Rubber Chemistry and Technology 71 (1998), pages 62 ff.).

For this purpose, EP-A-507 222 and US-A-5 112 929 describe cyclic 1,3-dioxolane acetals such as e.g. B. 2- (2-oxolanyl) dioxolane as micro structure regulator for the anionic polymerization of dienes. However, no statement is made regarding the polymerization rate achieved with this.

In the patents US-A-5 552 490, US-A-5 231 153, US-A-5 470 929, US-A-5 488 003 and US-A-5 359 016 alkyltetrahydroformryl ether are essentially suitable Modifiers for the anionic polymerization of dienes described. These regulators are said to be able to achieve much higher polymerization rates in the case of isoprene polymerization than in the case of TMEDA. However, these compounds are still too slow and at the same time are noticeable in the rubber due to an unpleasant smell.

There is therefore a need for microstructure controllers or randomizers that should meet the following extensive requirement profile:

1. The reduction in the microstructure control effect which occurs with increasing temperature should be small in order to enable a high polymerization temperature. Basically, the effect of a molecular structure regulator depends on the ratio of the molar amounts of regulator and initiator. The

Molar ratio regulator / initiator is generally between 1: 1 to 10: 1. The effect to be achieved according to 1. should already be achievable with a molar ratio regulator / initiator of less than 5: 1.

2. They should accelerate the copolymerizations so that profitable production services can be achieved.

3. They are intended to prevent the formation of block polyvinyl aromatic in copolymerizations of dienes with vinyl aromatics and thus have a good randomizer effect.

4. They should lead to high monomer conversions of at least 95%. 5. They should be largely inert to the "living" polymers present as anions in the polymerization. This requirement is of particular importance when the living polymers are converted into star-shaped rubbers or with suitable electrophilic compounds after the end of the polymerization with coupling agents. 6. They should be able to be completely separated from the polymerization solvent. Depending on the specific conditions of the respective polymerization plant, the focal points in the aforementioned requirements 1 to 6 can be weighted differently.

In view of the state of the art listed, there was no process for the preparation of polymers in which at least two compounds from the group of butadiene, isoprene and styrene are used and in which the above-mentioned requirements for the microstructure regulator which come from practice are ideal be fulfilled.

An object of the present invention is to provide a method of the type described above which avoids the aforementioned disadvantages. Another object of the invention is to produce non-blocking polymers (that is, in the case of diene copolymerization, the styrene units should be largely incorporated statically in the polymer chain so that the copolymers can be used, for example, to produce tires and damping materials). In particular, the polymers or rubbers obtainable by this process should have a glass transition temperature in the range from -70 ° C. to +10 ° C., in particular -30 ° C. to 0 ° C.

The subject of the present invention - according to a first aspect of the present invention - is therefore a method according to claim 1. Further advantageous configurations are the subject of the dependent claims (claims 2 to 10).

Another object of the present invention - according to a second aspect of the present invention - are the products or polymers obtainable by the process according to the invention. The process products or polymers according to the invention are distinguished in particular by a high proportion of 1,2-structural units of butadiene and 1,2- and 3,4-structural units of isoprene.

Another object of the present invention - according to a third aspect of the present invention - is the use of the products or polymers obtainable by the process according to the invention, as described in more detail in claims 12 to 16. Another object of the present invention - according to a fourth aspect of the present invention - are products produced with the polymers produced according to the invention, in particular damping materials, tires and tire components (for example tire treads or sidewalls) and technical rubber articles.

Finally, a further object of the present invention - according to a fifth aspect of the present invention - are the compounds of the general formulas (I c) and (I d) defined in claims 1 to 3, in particular for anionic polymerization.

The present invention shows that the compounds of the general formulas (I a) to (I g), as defined in the claims, can be used as Milσostmktur controllers and randomizers for anionic polymerization.

The compounds of the general formulas (I a) to (I g) have both the properties of a good microstructure regulator and that of a good randomizer. Compared to the many other known Lewis bases, the compounds of the general formulas (I a) to (I g) - generally ethers such as alkyl or alkylamino ethers or cyclic dioxolane or dioxane alkyl ethers or cyclic dioxolane or dioxane alkylamino ethers - have particular advantage of having a pronounced MilαO structure control effect even at a relatively high polymerization temperature (and consequently short reaction times).

The compounds of the general formula (I a) to (I g) used according to the invention can be prepared by the processes known per se and described in the literature. So z. B. the Akylaminoether used according to the invention for example by Williamson ether synthesis from a sodium alcoholate and the corresponding alkyl halide (DE 41 19 576 AI). 2-Dimethylaminomethyl-1,3-dioxolane (DM AD) is produced, for example, according to US Pat. No. 2,439,969 and DE 825 416.

An inert organic solvent is generally used as the reaction medium for the process according to the invention. Are particularly suitable Hydrocarbons with 5 to 12 carbon atoms, such as pentane, hexane, heptane and octane, and their cyclic analogs. Aromatic solvents such as. B. benzene, toluene, etc. Of course, mixtures of the compounds described above can be used.

Alkyl lithium compounds which are easily accessible by reacting lithium with the corresponding alkyl halides are generally used as the catalyst for the process according to the invention. The alkyl radicals generally have 1 to 10 carbon atoms. Individual hydrogen atoms can be substituted by phenyl radicals. The following alkyl lithium compounds are particularly suitable: methyl lithium, ethyl lithium and pentyllithium. Sec. And n-butyl lithium is preferred. In principle, bi-functional organic lithium compounds can also be used. However, these are less easily accessible and, in particular, less cheap than their monofunctional analogs if one wants to produce star-shaped solution rubbers.

The amount of catalyst used depends on the molecular weight to be adjusted. This is usually in the range of 50,000 to 1,500,000.

The microstructure regulator is preferably added at the start of the reaction. However, if it should be appropriate for any reason, it can also be added during the polymerization. The Milσostruktur controllers according to the invention can also be used individually or in any quantity ratio with one another.

If appropriate, it may be advantageous to add a potassium or sodium alcoholate in addition to the initiator in order to further improve the statistical distribution of the styrene units in the copolymers. For this purpose, the alkali metal or alkaline earth metal salts, in particular potassium or sodium salts, mono- or polyhydric alcohols and phenols and mono- or polyvalent carboxylic acids come into consideration. In general, the potassium compounds are preferred. Examples include the sodium or potassium salts of dimethylamine, di-n-butylamine, dibutylamine, lauric acid, palmitic acid, stearic acid, benzoic acid, phthalic acid, methyl alcohol, ethyl alcohol, Isopropyl alcohol, propyl alcohol, tert-butyl alcohol, tert-amyl alcohol, n-hexyl alcohol, cyclohexyl alcohol or phenol. Potassium tert-butoxide is particularly preferred.

Anionic surface-active compounds with a hydrophilic group, such as. B. -S0 ₃ M or -OS0 ₃ M, where M is potassium or sodium or rubidium, are additionally added to the initiator. Examples are salts of alkylarylsulfonic acids, such as. As potassium stearyl benzene sulfonate, potassium dodecyl benzene sulfonate, potassium nonyl benzene sulfonate and potassium decyl benzene sulfonate or salts of sulfuric acid esters of higher alcohols, such as. B. Potassium stearyl sulfate, potassium dodecyl sulfate, potassium decyl sulfate, potassium nonyl sulfate and potassium N-methyl taurate.

Based on 1 mol of the lithium alkyl initiator, amounts of 0.1 to 15 mol, preferably 0.1 to 5 mol, are generally used in the anionic polymerization using the microstructure regulators according to the invention.

The following compounds are suitable as conjugated dienes: 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene (piperylene), 2,3-dimethyl-1,3-butadiene and 1,3-hexadiene. 1,3-Butadiene and isoprene are particularly preferred.

The following vinyl aromatic compounds are suitable for copolymerization with the conjugated dienes: 3-methylstyrene, 4-methylstyrene, styrene, 1-vinylnaphthalene and 2-vinylnaphthalene, styrene being particularly preferred. The vinyl aromatic compounds as well as the conjugated dienes can be used individually or as a mixture with one another.

A variant of the process according to the invention consists in coupling the polymerization units obtained after the monomers have been largely reacted with a coupling agent to form star-shaped polymers. Coupling agents suitable for this purpose are in particular tetrahalides of the elements silicon, germanium, tin and lead and aromatics which carry at least two vinyl groups, such as, for example, B. 1,3,5-trivinylbenzene and 1,3- and 1,4-divinylbenzene. The polymerization is generally carried out in the temperature range from 50 to 90 ° C. The polymerization is preferably carried out at temperatures from 80 to 150.degree. The coupling is generally carried out at 0 to 150 ° C, preferably at 40 to 100 ° C.

The process according to the invention can be operated batchwise or continuously.

If the amorphous polymers obtained are to be processed into vulcanizates, they are generally mixed with active, reinforcing fillers, a vulcanizing agent and customary additives. The active and inactive fillers used in the rubber industry are used as fillers. Primarily, these are highly disperse silicas treated with silane coupling agents with specific surfaces of 5 to 1000 m ² / g, preferably 20-400 m ² / g, and with primary particle sizes of 10 to 400 μm and carbon blacks with BET surfaces of 20 up to 200 m ² / g. The fillers can be used alone or in a mixture.

Masses which are intended for the production of tire treads are generally formed into raw tread strips. In the case of homogenization and shaping, which can be carried out, for example, in an extruder, the conditions of temperature and time are chosen so that no vulcanization occurs.

The rubber component can in this case, for example, 10 to 70% by mass from a reaction product according to the invention and 90 to 30% by mass from a known, amorphous, highly unsaturated general-purpose rubber, such as. B. styrene / butadiene rubber, 1,4-cis-polybutadiene, 1,4-cis-polyisoprene or natural rubber.

Usual vulcanizing agents contain e.g. B. sulfur in combination with accelerators. The amount of the vulcanizing agent depends on the other components in the vulcanizable mass and can be determined by simple, orientation tests. As an additive, it is also possible, for example, to add the customary amounts of plasticizer oils customary in rubber technology, preferably aromatic, aliphatic and naphthenic and paraffinic hydrocarbons, and customary auxiliaries such as zinc oxide, stearic acid, resin acids, anti-aging agents and ozone protection waxes. Particularly preferred are the new, label-free naphthenic process oils of the type TDAE (Treated Distillate Aromatic Extracts), such as. B. BP Vivatec 500, or of the type MES (M Idly Refined Solvates), such as. B. BP Vivatec 200.

The polymers according to the invention are particularly suitable for the production of treads for car and truck tires, both for the production of new tires and for retreading old tires. The tire treads obtained are characterized by an excellent braking effect both in ABS braking and in blocking braking on wet roads. Also to be emphasized is the extraordinarily high reversion stability during the vulcanization process and the extraordinarily high network stability of the tire treads under dynamic stress. The polymers according to the invention can also be used for the production of damping elements (see, for example, DE-OS 24 59 357).

Further refinements, modifications and variations of the present invention are readily recognizable and realizable for the person skilled in the art on reading the description, without thereby leaving the scope of the present invention.

The present invention is illustrated by means of the following exemplary embodiments, which, however, in no way limit the present invention. EMBODIMENTS:

The polymers according to the invention are produced as follows:

A hydrocarbon mixture which consisted of approximately 50% n-hexane and is referred to as a C _{6 cut was} used as the solvent. Other components of this mixture were in particular pentane, heptane and octane and their isomers. The solvent was dried over a molecular sieve with a pore size of 0.4 nm, so that the water content was reduced to below 10 ppm, and then stripped with Na. The organic lithium compound was n-butyllithium (BuLi), which was used in the form of a 15 percent by weight solution in hexane. Before being used, isoprene was separated from the stabilizer by distillation. The glycol and amino ethers were dried over aluminum oxide and then titrated with n-butyllithium in the presence of o-phenanthroline.

The divinylbenzene (DVB) was used in the form of a solution dried over A1 ₂ 0 ₃ and containing 44% m- and 20% p-divinylbenzene. Coupling yield is the percentage of rubber which has a star-shaped structure after reaction with a coupling agent and which is distinguished from the uncoupled rubber by a considerably higher molecular weight. The determination is carried out with the GPC analysis, using tetrahydrofuran as the solvent and polystyrene as the column material. The polymers are characterized by a light scattering detector. For this purpose, samples are taken from the reactor before the coupling agent is added and at the end of the reaction.

The microstructure is determined by 'H-NMR or by means of IR spectrometry.

The glass transition temperature Tg was measured with a vibration elastometer (1 Hz at 1 ° C / min. Heating time). The block styrene content was determined according to Houben-Weyl, Methods of Organic Chemistry Vol. 14/1 (1961), page 698. The following examples serve to further illustrate the present invention without, however, restricting its scope.

basic tests

The controllers were used

MDE = 1-memoxy-2-dimethylaminoethane

EDE = 1-emoxy-2-dimethylaminoethane

PDE = 1-propoxy-2-dimethylaminoethane EDEE = 1-ethoxy-2-diethylaminoethane

BDE = 1-n-butoxy-2-dimethylaminoethane

EDP = 1-ethoxy-3-dimethylaminopropane

DMAD = 2-dimethylaminomethyl-1,3-dioxolane

TBEE = 1-ethoxy-2-tert-butoxy-ethane NBEE = 1-ethoxy-2-n-butoxy-ethane

example 1

In a V2A autoclave flushed with dry nitrogen, 400

Parts of hexane, a monomer mixture of 40 parts of 1,3-butadiene, 40 parts of isoprene, 20 parts of styrene, 0.02 parts of DVB and 1.0 part of ethylene glycol tert-butyl ether (TBEE), and after drying over molecular sieves (0, 4 µm) titrated with butyllithium under thermoelectric control. The polymerization was started at 40 ° C. by adding 0.05 part of n-butyllithium. The temperature reached 108 ° C after 8 minutes with slight cooling. At this temperature, the mixture was allowed to react for 30 minutes. After cooling to 50 ° C., the polymerization was stopped by adding a solution of 0.5 part of 2,2'-methylene-bis (4-methyl-6-tert-butylphenol) in 2 parts of moist toluene. The solvent was distilled off with steam and the polymer was dried in a forced-air drying cabinet at 70 ° C. for 24 hours.

Examples 2 to 8

The procedure corresponds to example 1. Experiments 1 to 3 are to be regarded as comparative experiments. The results are summarized in Table 1. Table 1: Basic tests

^* 'contained in 1,2 butadiene

resistance

In order to determine the resistance of the regulator to the living chain ends, star polymers were produced in the subsequent experiments.

Example 9

550 parts of hexane, a monomer mixture of 75 parts of 1,3-butadiene and 25 parts of styrene and 0.7 part of l-ethoxy-2-n-butoxyethane are placed in a V2A autoclave flushed with dry nitrogen and, after drying over molecular sieves (0 , 4 nm) titrated with butyl lithium under thermoelectric control. The polymerization was started at 35 ° C. by adding 0.080 parts of n-BuLi. The temperature reached 113 ° C after 10 minutes with slight cooling. At this temperature, the mixture could react for 30 minutes. Then 0.81 part of divinylbenzene was added at this temperature. After 20 minutes and after cooling to 50 ° C., the polymerization was carried out by adding a solution of 0.5 part of 2,2'-methylene bis (4-methyl-6-tert-butylphenol) stopped in 2 parts of wet toluene. The solvent was distilled off with steam and the polymer was dried in a forced-air drying cabinet at 70 ° C. for 24 hours.

Examples 10 to 12

The procedure corresponds to example 9 (see table 2).

Table 2: Production of the star polymers

^* '1,2 butadiene contains determination of the block styrene content according to Houben-Weyl, Methods of Organic Chemistry Vol. 14/1 (1961), page 698 Temperature dependence and speed

The temperature dependence of the microstructure control effect was investigated using isoprene and butadiene polymerizations. The microstructures of the polyisoprenes were determined by 'H-NMR analysis. In order to be able to compare the rates of the polymerizations carried out with the individual regulators, the reaction rate constants were calculated from the time conversion curves in accordance with a 1st order reaction.

Homopolymerization of isoprene

704 g of hexane, 82 g (1.21 mol) of isoprene and 4.7 mmol of the corresponding regulator as microstructure regulator are introduced into a 2-1 steel autoclave under a nitrogen atmosphere. After the temperature control, the reactor contents are titrated with 0.4 mmol of n-butyllithium (14% solution in hexane) until the color changes, after addition of 1 ml of 1% benzene o-phenanthroline solution, and the polymerization is carried out by adding 0.94 mmol n-butyllithium started. The polymerization was stopped after two hours. The 3,4-polyisoprene was stabilized with 0.5% BKF and worked up by precipitation with isopropanol / methanol and subsequent drying at 50 ° C. The microstructure of the polymer is determined by 'H-HMR analysis:

Table 3: Temperature dependency of the microstructure control effect and reaction speed, mol ratio regulator / BuLi = 5 / l, isoprene = 1.0 mol / l

Starting from EDE, shortening the R ₅ radical from ethyl to methyl (MDE) on the one hand leads to slightly higher levels of 1,2- and 3,4-polyisoprene, but on the other hand leads to a drastic, unacceptable drop in monomer conversion. The exchange of the ethyl for an n-butyl group on oxygen has no influence on the 1,2- and 3,4-content of the polyisoprene.

An extension of the alkyl residues on the nitrogen atom from methyl to ethyl (EDEE) causes a decrease in the side chain branches and thus the Milσostruktur control effect.

Extending the distance between the two donor atoms from - (CH ₂ ) ₂ - to - (CH ₂ ) ₃ - (EDP) results in a significantly lower microstructure control effect. Of the three amino ethers EDE, PDE and BDE, which have a very good milk structure control effect, EDE and PDE have the highest Polymerization rates. NBEE is also significantly faster than TBEE.

Homopolymerization of Butadiene Exemplary polymerisation experiments were carried out with butadiene, similar to the isoprene polymerisation experiments. The results are summarized in Table 4.

Table 4: Microstructure control effect and reaction rate in butadiene polymerization at 70 ° C and molar ratio controller / BuLi = 5 / l, butadiene = 1.0 mol / 1

Here too, EDE is significantly faster than TBEE, although EDE also performs better in the microstructure control at 70 ° C.

Randomizerwirkung

The randomizer effects of the regulators were investigated using isothermal butadiene / styrene copolymerizations with 40% by weight styrene at 50 ° C. with a regulator / n-BuLi ratio of 5.

Copolymerization of butadiene and styrene to determine the randomizer effect 703 g of hexane, 50.6 g (0.94 mol) of butadiene, 33.7 g (0.32 mol) of styrene and 4.8 are placed in a 2-1 steel reactor under a nitrogen atmosphere mmol filled microstructure regulator. After the temperature has been raised to 50 ° C., the reactor contents are titrated with 0.33 mmol of n-butyllithium (14% solution in hexane) until the color changes, after addition of 1 ml of 1% benzene o-phenanthroline solution, and the polymerization started by adding 0.96 mmol of n-butyllithium. The structure of the copolymer is determined by IR analysis. The block polystyrene content is determined by KMn0 ₄ degradation. The results are summarized in Table 5. Table 5: Randomizer effect when copolymerizing butadiene / styrene 60/40 at 50 ° C

*) due to the termination of the polymerization, no analysis for block polystyrene was carried out.

While MDE and EDP terminate the copolymerization with lower monomer conversions, the lengthening of the alkyl groups on the nitrogen atom leads to a drastic increase in the block polystyrene content.

An extension of the alkyl groups on the oxygen atom from ethyl to n-butyl shows no serious influence on the randomizer effect.

Claims

claims:

Process for the preparation of optionally coupled, non-blocking polymers based on conjugated dienes and optionally monovinylaromatic compounds by anionic polymerization in an inert organic solvent in the presence of an organic lithium compound as initiator and a microstructure regulator and / or randomizer, characterized in that the microstructure regulator and / or randomizer uses the following compounds), alone or in combination: a)

\

CHOIR.

R ₄ da)

wherein R and R ₂ independently represent CC ₄ alkyl radicals, R ₃ and R ₄ independently represent H or C _r C ₆ alkyl radical and R _{5 is} a C _r C ₄ alkyl radical or a radical of the formula

represents;

b)

\ / ~ \

N CH ₂ CH, (CR ₂ )

wherein R represents a hydrogen atom or a C _r C ₄ alkyl radical and R 1 and R ₂ independently represent C, -C ₄ alkyl radicals and x is 0 or 1;

c)

wherein R represents a hydrogen atom or a C _r C ₄ alkyl radical and R, and R ₂ independently represent C _r C ₆ alkyl radicals and x = 0 or 1;

d)

(I d)

wherein R represents a hydrogen atom or a CC ₄ alkyl radical and R, represents a CC ₆ alkyl radical and x = 0 or 1;

e)

where R represents a hydrogen atom or a C _r C ₄ alkyl radical and R _! represents a hydrogen atom or a C _r C ₆ alkyl radical and x = 0 or 1 and n = 3 or 4;

)

wherein R] is an n-butyl radical and R _{2 represents} a hydrogen atom or a C _r C ₆ alkyl radical;

G)

in which:

X, Y and Z independently represent a radical -OR with R = C _r C ₆ alkyl; or but

X and Y independently of one another represent a radical -OR with R = -C ₆ - alkyl and Z represents a radical -N (R) ₂ with R = C, -C ₆ - alkyl; or X represents a radical -OR with R = C, -C ₆ - alkyl and Y and Z independently of one another represent a radical -N (R) ₂ with R = CC ₆ - alkyl; or X, Y and Z independently of one another a radical -N (R) ₂ with R = CC ₆ -

Represent alkyl.

, A method according to claim 1, characterized in that the microstructure regulator and / or randomizer is selected from the group of the following compounds according to claim 1:

• Compound (s) of the general formula (I a) with R ,, R ₂ = methyl; R ₃ , R ₄ = H and R ₅ = C _r C ₄ alkyl

• Compound (s) of the general formula (I b) with x = 0 and R = H and R _b R ₂ = methyl or ethyl

• Compound (s) of the general formula (I c) with x = 0 and R = H and RR ₂ = methyl or ethyl

• Compound (s) of the general formula (I d) with x = 0 and R = H and R, = methyl or ethyl

3. The method according to claim 1 or 2, characterized in that the microstructure regulator and / or randomizer is selected from the group of l-ethoxy-2-dimethylaminoethane, l-propoxy-2-dimethylaminoethane, 2-dimethylaminomethyl-1,3 -dioxolane, 2-ethoxymethyl-

1,3-dioxolane, dimethyl- (2-ethoxymethyl-l, 3-dioxolanethyl) amine and 1-ethoxy-2-n-butoxyethane.

4. The method according to any one of claims 1 to 3, characterized in that additional alcoholates with the general formula MOR, wherein

M is an alkali metal, preferably sodium or potassium, and R is an alkyl group with 2 to 8 carbon atoms, in particular where the molar ratio of microstructure regulator (s) and / or randomizer (s) to alcoholate is in the range from 1: 0 , 1 to 1: 1 can be.

5. The method according to any one of claims 1 to 4 for the anionic polymerization of at least two monomers from the group of butadiene, isoprene and styrene.

6. The method according to any one of claims 1 to 5, characterized in that the following monomer mixtures are used, the percentages in each case relating to the weight of the total mixture:

• mixture of isoprene and up to 75% butadiene; • mixture of isoprene and up to 45% styrene;

• mixture of butadiene and up to 45% styrene;

• Mixture of 15 to 75% butadiene, 20 to 85% isoprene and up to 45% styrene.

7. The method according to any one of claims 1 to 6, characterized in that the microstructure regulator and / or randomizer are used individually or in any combination with one another.

8. The method according to any one of claims 1 to 7, characterized in that the microstructure regulator and / or randomizer are added at the beginning of the polymerization or the microstructure regulator and / or randomizer are added in doses over the course of the polymerization, in particular with a two to three doses are particularly preferred.

9. The method according to any one of claims 1 to 8, characterized in that the molar ratio of microstructure regulator (s) and / or randomizer (s) to initiator (s) in the range from 0.5: 1 to 15: 1; in particular 0.1: 1 to 5: 1.

10. The method according to any one of claims 1 to 9, characterized in that a coupling agent is added to the polymerization batch, preferably at the end of the reaction, the coupling agent in particular being a di- or trivinylbenzene or silicon tetrachloride.

1 1. Polymers which can be prepared by the process according to claims 1 to 10.

12. Use of the polymers obtainable by the process according to claims 1 to 10 for the production of damping materials, tires and tire components, such as tire treads or sidewalls.

13. Use of the polymers obtainable by the process according to claims 1 to 10 for the production of technical rubber articles.

14. Use of the polymers obtainable by the process according to claims 1 to 10 for modifying plastics.

15. Use of microstructure regulator (s) and / or randomizer (s), as defined in claims 1 to 3, for the production of polymers based on conjugated dienes and optionally monovinylaromatic compounds.

16. Use of microstructure regulator (s) and / or randomizer (s) as defined in claims 1 to 3 for the anionic polymerization, in particular for the anionic polymerization of at least two

Monomers from the group of butadiene, isoprene and styrene.

17. Damping materials, tires and tire components, such as tire treads or sidewalls, as well as technical rubber articles, produced on the basis of polymers obtainable by the process according to claims 1 to 10.

18. Compounds of the general formulas (I c) and (I d), as defined in claims 1 to 3, in particular for the anionic polymerization.