Process for producing diene polymers

Abstract

The invention describes a process for producing a diene polymer, the process comprising the following steps in this order: i) polymerizing one or more diene monomers in the presence of a catalyst composition to give a reaction mixture; ii) adding to the reaction mixture one or more alkoxysilane compounds; iii) adding S.sub.2Cl.sub.2, SCl.sub.2, SOCl.sub.2, S.sub.2Br.sub.2, SOBr.sub.2 or a mixture thereof to the reaction mixture; and iv) optionally adding a protic agent to the reaction mixture so as to deactivate the catalyst. The invention further includes polymers that are obtainable according to this process, as well as products including the polymer.

Claims

1. Process for producing a diene polymer, the process comprising the following steps in this order: i) polymerizing one or more diene monomers in the presence of a catalyst composition to give a reaction mixture; wherein the catalyst composition comprises one or more of a carboxylate, an alkyl phosphate, an alkyl phosphite, an alcoholate, an amide and a hydrocarbyl compound of a rare earth element having an atomic number of 57 to 71 in the periodic table, and at least one activator compound, or a reaction product of the at least one activator compound and the carboxylate, alkyl phosphate, alkyl phosphite, alcoholate, amide and/or hydrocarbyl compound of the rare earth element; ii) adding to the reaction mixture one or more alkoxysilane compounds selected from the compounds represented by the following formulae (A1), (A2), (A3), (A4) and (A5):
((R.sup.1O).sub.q(R.sup.2).sub.rSi).sub.s  (A1) wherein in formula (A1): Si is silicon and O is oxygen; s is an integer selected from 1 and 2; with the proviso that if s is 1, then q is an integer selected from 2, 3 and 4; r is an integer selected from 0, 1 and 2; and q+r=4; and if s is 2, then q is an integer selected from 1, 2 and 3; r is an integer selected from 0, 1 and 2; and q+r=3;
((R.sup.3O).sub.t(R.sup.4).sub.uSi).sub.2O  (A2) wherein in formula (A2): Si and O are as defined above; t is an integer selected from 1, 2 and 3; u is an integer selected from 0, 1 and 2; and t+u=3;
(R.sup.5O).sub.w(R.sup.6).sub.xSi—R.sup.7—S—SiR.sup.8.sub.3  (A3) wherein in formula (A3): Si and O are as defined above, and S is sulfur; w is an integer selected from 2 and 3; x is an integer selected from 0 and 1; and w+x=3;
(R.sup.9O).sub.y(R.sup.10).sub.zSi—R.sup.11—N(SiR.sup.12.sub.3).sub.2  (A4) wherein in formula (A4): Si and O are as defined above, and N is nitrogen; y is an integer selected from 2 and 3; z is an integer selected from 0 and 1; and y+z=3;
(Si(OR.sup.13).sub.3).sub.2(Si(OR.sup.14).sub.2).sub.p  (A5) wherein in formula (A5): Si and O are as defined above; p is an integer selected from 1 to 10; and wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.8, R.sup.9, R.sup.10, R.sup.11, R.sup.13 and R.sup.14 in the above formulae (A1) to (A5) independently are selected from: (C.sub.6-C.sub.21) aryl, (C.sub.7-C.sub.22) alkylaryl and (C.sub.1-C.sub.16) alkyl; and R.sup.7 and R.sup.11 in formulae (A3) and (A4) independently are a divalent (C.sub.6-C.sub.21) aryl group, a divalent (C.sub.7-C.sub.22) alkylaryl group, or a divalent (C.sub.1-C.sub.16) alkylen group; iii) adding S.sub.2Cl.sub.2, SCl.sub.2, S.sub.2Br.sub.2, SOBr.sub.2 or a mixture thereof to the reaction mixture; and iv) optionally adding a protic agent to the reaction mixture so as to deactivate the catalyst.

2. The process according to claim 1, wherein the one or more diene monomer comprises at least one of 1,3-butadiene, isoprene, 1,3-pentadiene and 2,3-dimethyl-1,3-butadiene or a mixture thereof.

3. The process according to claim 1, wherein groups R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.8, R.sup.9, R.sup.10, R.sup.12, R.sup.13 and R.sup.14 in formulae (A1) to (A5) independently from each other are C.sub.1-8 alkyl groups.

4. The process according to claim 1, wherein groups R.sup.1, R.sup.3, R.sup.5, R.sup.9, R.sup.13 and R.sup.14 in formulae (A1) to (A5) independently from each other are C.sub.1-4 alkyl groups.

5. The process according to claim 1, wherein the rare earth element is one or more of lanthanum, praseodymium, cerium, neodymium, gadolinium and dysprosium.

6. The process according to claim 1, wherein the catalyst composition comprises a neodymium carboxylate.

7. The process according to claim 1, wherein the activator compound comprises dialkylaluminum hydride according to general formula (A6) and a Lewis acid:
R.sup.15.sub.2AlH  (A6) wherein both groups R.sup.15 in formula (A6) independently from each other are C.sub.1-10 alkyl groups.

8. The process according to claim 7, wherein the Lewis acid is an alkyl aluminum chloride selected from alkyl aluminum sesquichloride, dialkyl aluminum chloride and alkyl aluminum dichloride.

9. The process according to claim 1, wherein S.sub.2Cl.sub.2, SCl.sub.2, S.sub.2Br.sub.2, SOBr.sub.2 or the mixture thereof is added in an amount of less than 0.05 parts by weight based on 100 parts by weight of diene polymer.

10. The process according to claim 1, wherein the one or more alkoxysilane compounds are selected from the compounds represented by formulae (A1), (A2), (A3) and (A4).

11. The process according to claim 1, wherein the one or more alkoxysilane compounds are selected from the compounds represented by formulae (A1) and (A3).

12. The process according to claim 1, wherein the one or more alkoxysilane compounds are selected from (CH.sub.3O).sub.4Si, ((CH.sub.3O).sub.3Si).sub.2 and (CH.sub.3O).sub.3Si—(CH.sub.2).sub.3—S—Si(CH.sub.3).sub.2C(CH.sub.3).sub.3.

13. The process according to claim 1, further comprising the additional step v): adding oil and/or a filler.

14. The process according to claim 1, further comprising the additional step vi): adding a vulcanizing agent and vulcanizing the polymer.

Description

EXAMPLES

(1) Test Methods

(2) cis-1,4- and 1,2-polybutadiene content

(3) The concentration of cis-1,4- and 1,2-polybutadiene was determined by IR and 13C NMR-spectroscopy. The 1D NMR spectra were collected on a BRUKER Avance 200 NMR spectrometer (BRUKER BioSpin GmbH), using a “5 mm Dual detection probe.” The field homogeneity was optimized by maximizing the deuterium lock signal. The samples were shimmed by optimizing the deuterium lock signal. The samples were run at room temperature (298 K). The following deuterated solvents were used: C6D6 (7.15 ppm for 1H; 128.02 ppm for 13C), the signals of the remaining protons of deuterated solvents were each used as an internal reference.

(4) For spectral processing, the BRUKER 1D WINNMR software (version 6.0) was used. Phasing, base line correction and spectral integration of the resulting spectra was done in the manual mode. For acquisition parameters see Table 1.

(5) TABLE-US-00001 TABLE 1 1D-NMR acquisition parameters using BRUKER standard pulse sequences 1H-NMR 13C-NMR Observe frequency 200.130 MHz 50,323 MHz Spectral width 4139.073 Hz 12562.814 BRUKER Pulse Zg30 Zgpg30 program Pulse angle 30° 30° Relaxation delay 1.0 s 2.0 s Number of Data 32K 32K points for FT Line broadening 0.5 Hz 1 Hz Number of 64 >1000 accumulated scans
Size Exclusion Chromatography

(6) Molecular weight and molecular weight distribution of the polymer were each measured using Size Exclusion Chromatography (SEC) based on polystyrene standards.

(7) Sample Preparation:

(8) a1) Oil free polymer samples:

(9) About “9-11 mg” dried polymer sample (moisture content <0.6%) was dissolved in 10 mL tetrahydrofurane, using a brown vial of 10 mL size. The polymer was dissolved by shaking the vial for 20 min at 200 u/min.

(10) a2) oil containing polymer samples:

(11) About “12-14 mg” dried polymer sample (moisture content <0.6%) was dissolved in 10 mL tetrahydrofurane, using a brown vial of 10 mL size. The polymer was dissolved by shaking the vial for 20 min at 200 u/min.

(12) b) Polymer solution was transferred into a 2 ml vial using a 0.45 μm disposable filter.

(13) c) The 2 ml vial was placed on a sampler for GPC-analysis.

(14) Elution rate: 1.00 mL/min

(15) Injection volume: 100.00 μm (GPC-method B 50.00 μm)

(16) The measurement was performed in THF at 40° C.). Instrument: Agilent Serie 1100/1200; Module setup: Iso pump, autosampler, thermostate, VW—Detector, RI—Detector, Degasser; Columns PL Mixed B/HP Mixed B.

(17) In each GPC-device 3 columns were used in an connected mode. The length of each of the columns: 300 mm; Column Type: 79911 GP-MXB, Plgel 10 μm MIXED-B GPC/SEC Columns, Fa. Agilent Technologies (eigentlicher Hersteller ist auch Polymer Laboratories)

(18) GPC Standards: EasiCal PS-1 Polystyrene Standards, Spatula A+B (Styrene Standard Manufacturer: Polymer Laboratories (Now entity of Varian, Inc.; Varian Deutschland GmbH; http://www.polymerlabs.com)

(19) Mooney Viscosity ML1+4 (100° C.)

(20) Mooney viscosity was measured according to ASTM D 1646 (2004), with a preheating time of one minute and a rotor operation time of 4 minutes, at a temperature of 100° C. [ML1+4(100° C.)], on a MV 2000E from Alpha Technologies UK. The rubber Mooney viscosity measurement is performed on dry (solvent free) raw polymer (unvulcanized rubber). The Compound Moony viscosity is measured on an uncured (unvulcanized) second state polymer compound sample prepared according to Tables 4, 5 and 6. The Compound Mooney values are listed in Tables 8 and 10.

(21) Vulcanizate Compound Properties

(22) Tensile Strength, Elongation at Break and Modulus at 300% Elongation (Modulus 300) were measured according to ASTM D 412-98A (reapproved 2002), using a dumbbell die C test pieces on a Zwick Z010. Of the standardized dumbbell die C test pieces, those of “2 mm thickness” were used. The tensile strength measurement was performed at room temperature, on a cured (vulcanized) second stage polymer sample, prepared according to Tables 4, 5 and 6. Stage 2 formulations were vulcanized within 20 minutes at 160° C. to TC 95 (95% vulcanization conversion).

(23) Heat build up was measured according to ASTM D 623, method A, on a Doli ‘Goodrich’-Flexometer. The heat built up measurement was performed on vulcanized second stage polymer samples.

(24) Tan δ at 60° C. and Tan δ at 0° C., as well as Tan δ at −10° C. measurements, were performed on cylindrical specimen, using a dynamic mechanical thermal spectrometer “Eplexor 150N,” manufactured by Gabo Qualimeter Testanlagen GmbH (Germany), by applying a compression dynamic strain of 0.2%, at a frequency of 2 Hz, at the respective temperatures. The smaller the index at a temperature of 60° C., the lower is the rolling resistance. Tan δ (0° C.) was measured using the same equipment and load conditions at 0° C. The larger the index at this temperature, the better the wet skid resistance. Tan δ at 60° C. and Tan δ at 0° C., as well as Tan δ at −10° C. were determined (see Tables 9 and 11).

(25) DIN abrasion was measured according to DIN 53516 (1987-06-01). The larger the index, the lower the wear resistance. The abrasion measurement was performed on a vulcanized, second stage polymer formulation. In general, the higher the values for Elongation at Break, Tensile Strength, Modulus 300, and Tan δ at 0° C., the better the sample performance; whereas the lower the Tan δ at 60° C., Heat Build Up, and Abrasion, the better the sample performance.

Examples 1 to 3—Batch Polymerisation/In Situ Formation of Catalyst

(26) 4000 g Cyclohexane and 1,3-butadiene (see table 1 for amount of 1,3-butadiene) were placed in a 20 l polymerization pressure reactor (available from Karl Kurt Juchheim Laborgerate GmbH, 1997 model, fabric. No. 2245) under nitrogen at 20° C. before adding di-iso-butyl aluminum hydride (DiBAH; 0.25 molar solution in Cyclohexane) and diethylaluminum chloride (DEAC; 0.1 molar solution in cyclohexane) in the amounts specified in table 1.

(27) 360 g cyclohexane was placed in a second pressure vessel under nitrogen (1 to 2 liter pressure reaction vessel available from Büchiglasuster, fabric. No. 3618, model 2002) and cooled to 10° C. before 8 g DiBAH (0.25 molar solution in cyclohexane), Neodymium(versatate).sub.3 (0.029 molar in cyclohexane; NdV40® purchased from Rhodia; see “rare earth element compound” in table 1 for amount) and 1,3-butadiene (molar ratio of butadiene to Nd=12) were added.

(28) Polymerization was started by adding the content of the second vessel to the polymerization reactor. The temperature was adjusted to 65° C. and rose up to 80° C. within 30 min. Monomer conversion was monitored using a halogen moisture Analyzer HR 73 (Mettler Toledo) by weighing 3 to 4 g polymer solution into 50 ml Ethanol, filtering and transferring the precipitate to the sample holder of the moisture analyzer and drying at 140° C. for 5 to 10 minutes until weight remains constant. Conversion is calculated as: conversion %=[weight (dried polymer sample)*(total weight of reaction mixture)*100]/[weight (sample of polymer solution)*total weight of monomers]. Once 98% butadiene conversion was reached, a solution of alkoxysilane (1 weight percent in cyclohexane) was added (see table 1 for amount and silane). The reaction mixture was stirred for another 15 minutes before a solution of disulfur dichloride (0.1 weight percent in cyclohexane) was added in the amount specified in table 1.

(29) The resulting polymer solution was stirred for 30 minutes before it was stripped with steam for one hour to remove solvent and other volatiles and dried in an oven at 70° C. for 30 minutes and another one to three days at room temperature.

Examples 4 to 6, 8 to 10—Continuous Polymerisation/Preformed Catalyst

(30) Examples 4 to 6 and 8 to 10 were performed by means of three continuous stirred tank reactors (CSTRs) connected in series. Each reactor had a volume of 5 liter and was equipped with a helicoidal stirrer, suitable for mixing high viscous solutions, the speed of the stirrer during all trials was 200 rpm. External water circulation in the reactor walls regulated the temperature of all three reactors to 80° C.

(31) The reagents required for polymerization, i.e. the preformed catalyst (COMCAT Nd8.8; available from COMAR Chemicals Ltd.; applied as solution of 0.022 mol Nd per kg cyclohexane solution) and 1,3-butadiene (see table 1 for amount) as well as cyclohexane were continuously fed into the head of the first reactor with mass flow-meters. Each flow-meter regulated the desired feed, and guaranteed a constant flow of the reagent. The flow of the preformed catalyst was 0.68 to 0.69 mmol/h based on Nd (see “rare earth element compound” in table 1 for exact amount), the values indicated in table 1 are calculated based on the product specification available from COMAR Chemicals Ltd. taking this flow into account. The flow of butadiene is indicated in table 1. The flow of cyclohexane was adjusted such that the total flow of reactants and solvent was 2.500 g/h.

(32) The flow of the total amount of 1,3-butadiene, catalyst solution and solvent was adjusted in order to achieve a residence time of 115 minutes in each reactor. The conversion after the first reactor was >95% conversion (calculated as described above with respect to Example 1). In the second reactor, a solution of alkoxysilane (1 weight percent in cyclohexane) was added to the polymer solution (see table 1 for amount and silane) followed by the addition of a solution of disulfur dichloride (0.1 weight percent in cyclohexane) through the inlet of the third reactor see table 1 for amount).

(33) The resulting polymer solution continuously collected and afterwards stripped with steam for one hour to remove solvent and other volatiles and dried in an oven at 70° C. for 30 minutes and another one to three days at room temperature.

Example 7—Batch Polymerisation/Preformed Catalyst

(34) 4000 g Cyclohexane and 1,3-butadiene (see table 1 for amount of 1,3-butadiene) were placed in a 20 l polymerization pressure reactor (available from Karl Kurt Juchheim Laborgerate GmbH, 1997 model, fabric. No. 2245) under nitrogen at 20° C. Polymerization was started by adding a solution of a preformed catalyst containing 0.89 mmol based on Nd (COMCAT Nd8.8; available from COMAR Chemicals Ltd.; applied as solution of 0.022 mol Nd per kg cyclohexane solution; amount as indicated in table 1-see “rare earth element compound”; the values for DEAC/EASC and DiBAH are estimated based on the product specification available from COMAR Chemicals Ltd.) to the polymerization reactor. The temperature was adjusted to 65° C. and rose up to 80° C. within 20 minutes. Monomer conversion was monitored as described above for Example 1. Once 98% Butadiene conversion was reached, 3.5 mmol “alkoxysilane compound SS” (see below for preparation of alkoxysilane compound SS) was added. The reaction mixture was stirred for another 15 minutes before adding 1 mmol disulfur dichloride.

(35) The resulting polymer solution was stirred for 30 minutes before it was stripped with steam for one hour to remove solvent and other volatiles and dried in an oven at 70° C. for 30 minutes and another one to three days at room temperature.

(36) Preparation of Alkoxysilane Compound SS

(37) Alkoxysilane Compound SS is represented by Formula SS below, and can be prepared as follows by preparation pathway 1 or 2.

(38) ##STR00001##
Preparation Pathway 1 (SS):

(39) To a 100 mL Schlenk flask was charged 25 ml tetrahydrofuran (THF), 79.5 mg (10 mmol) lithium hydride, and subsequently, 1.96 g (10 mmol) gamma-mercaptopropyl trimethoxy silane [Silquest A-189] from the Cromton GmbH. The reaction mixture was stirred for 24 hours at 20 to 25° C., and another two hours at 50° C. Then, tert-butyl dimethyl chloro silane (1.51 g (10 mmol)) was dissolved in 10 g THF, and the resulting solution was added drop wise to the Schlenk flask. Lithium chloride precipitated. The suspension was stirred for about 24 hours at room temperature, and for another two hours at 50° C. The THF solvent was removed under vacuum before cyclohexane (30 ml) was added to yield a white precipitate. The white precipitate was subsequently separated by filtration. The cyclohexane solvent was removed under vacuum (reduced pressure). The resulting colorless liquid proved to be alkoxysilane compound SS in 99% purity (GC), and therefore no further purification was necessary. A yield of 2.9 g (9.2 mmol) of modified coupling agent (SS) was obtained.

(40) Preparation Pathway 2 (SS):

(41) To a 100 mL Schlenk flask was charged 1.96 g (10 mmol) gamma-mercaptopropyl trimethoxy silane [Silquest A-189] from Cromton GmbH, 25 ml tetrahydrofuran (THF), and subsequently, 0.594 g (11 mmol) sodium methanolate (NaOMe) dissolved in 10 mL THF. The reaction mixture was stirred for 18 hours at 20 to 25° C. Then, tert-butyl dimethyl chloro silane (1.51 g (10 mmol)) was dissolved in 10 g THF, and the resulting solution was added drop wise to the Schlenk flask. Sodium chloride precipitated. The suspension was stirred for about 24 hours at room temperature, and for another two hours at 50° C. The THF solvent was removed under vacuum before cyclohexane (30 ml) was added to yield a white precipitate which was subsequently removed by filtration. The cyclohexane solvent was removed under vacuum (reduced pressure). The resulting colorless liquid solution proved to be alkoxysilane compound SS in 89% purity (GC). After further purification by means of fractionated distillation, a yield of 2.2 g (7.2 mmol) of alkoxysilane compound SS was obtained.

(42) TABLE-US-00002 TABLE 1 polymerization rare alkoxy earth silane Thio Ex- element 1,3- compound compound am- compound DEAC.sup.1 DiBAH butadiene (silane: (S2Cl2; ple (mmol) (mmol) (mmol) (mol) mmol) mmol) 1 1   2.5  12 12.37 0 0 2 1.05 2.57   13.3 12.73 TMS: 2.5 4.46 3 1.13 2.51 12 12.7  HMDS: 1.6 3.22 4 0.68/h 1.7-2/h 7-12/h 6.1/h TMS: 0.5/h 0.55/h 5 0.69/h 1.7-2/h 7-12/h 6.2/h TMS: 0.6/h 0.32/h; HMDS: 0.08/h 6 0.69/h 1.7-2/h 7-12/h 6.3/h HMDS: 0.54/h  0.3/h 7 0.89 2.2-2.6 9-15 6.3 ,,SS”: 1 3.5 8 0.68/h 1.7-2/h 7-12/h 6.2/h TMS: 0.5/h 0.6/h 9 0.68/h 1.7-2/h 7-12/h 6.1/h TMS: 0.5/h 0.55/h 10 0.69/h 1.7-2/h 7-12/h 6.1/h HMDS: 0.4/h 0.3/h TMS = tetramethoxysilane HMDS = hexamethoxydisilane .sup.1instead of DEAC alone, a mixture of diethyl aluminum chloride (DEAC) and ethyl aluminum sesquichloride (EASC) was used in examples 4 to 10 for catalyst formation

(43) The polymers obtained according to examples 1 to 10 were analyzed. The cis-1,4 polybutadiene content was determined to be above 96% for each polymer, the trans-1,4 content was of from 1.5 to 2.5% for each polymer, and the vinyl content (1,2-polybutadiene unit content) was found to be 1 mol % for each polymer. Further polymer characteristics are given in Table 2.

(44) TABLE-US-00003 TABLE 2 Polymer Characteristics Polymer Solution Viscosity [cPoise at Mooney Polymer Mn.sup.A Mw.sup.A shear-rate viscosity Example [g/mol] [g/mol] Mw/Mn.sup.A 16/s] [MU] 1 247223 853819 3.45 17500E 43.6 2 185190 670038 3.63 20200D 45.5 3 211410 711052 3.36 n.d..sup.G 47.6 4 n.d. n.d. n.d. n.d. 41.8 5 217812 463498 2.13 n.d. 43.6 6 195969 470850 2.40 n.d. 40.6 7 252037 571765 2.27 n.d. 46.6 8 181403 444036 2.45 12200E 41.2 9 192888 453605 2.35 n.d. 41.8 10 194744 442152 2.27 n.d. 40.0 CB25.sup.F 273917 599730 2.19 24200D 46.0 D: measured at 19 wt.-% polymer concentration in cyclohexane at 70° C. using a RS600 rheometer instrument from Thermo-Haake, Germany; E: measured at 19 wt.-% polymer concentration in an equimolar mix of n-hexane and n-heptane at 45° C. using a RheolabQC instrument from Anton Paar. .sup.FCB25 is a high cis butadiene rubber that is commercially available from Lanxess and is produced using a neodymium catalyst and reacting the polymer chains with S2C12. .sup.Gn.d.—not detected
Polymer Compositions Comprising a Filler

(45) Polymer compositions were prepared by combining the polymers obtained in examples 1 to 10 above or commercially available polymer CB25 with the constituents listed below in Table 4 (for polymers obtained in examples 1, 2 and 3), Table 5 (for polymers obtained in examples 4, 5, 6 and 7 or CB25) and Table 6 (for polymers obtained in examples 5, 8, 9 and 10 or CB25), in a “380 cc Banbury mixer (Labstation 350S from Brabender GmbH&Co KG),” following a two-stage mixing process. Stage 1: all components as indicated in tables 4 or 5 were mixed together for 7 minutes at 70 to 80 rpm, except for the components of the vulcanizing agent (i.e. sulfur, TBBS, and DPG) to form a stage 1 formulation. Stage 2: Subsequently, the vulcanizing agent was added and the mixture was mixed for additional 3 minutes at 40 rpm to give stage 2 formulations. Corresponding values for stage 1 and stage 2 formulations obtained from the components identified in table 6 are: 6 minutes at 90 rpm (stage 1) and 3 minutes at 50 rpm (stage 2), respectively. Mooney values were determined for each of these compositions (“stage 2 formulation”) and are indicated in tables 8 and 10 below as “Compound Mooney” values. Values for the compositions addressed in tables 4 and 6 were each determined after sample preparation by the same operator on the same day. Likewise, Compound Mooney values for composition 4 and 5 (table 5) were determined after sample preparation by the same operator on one day, and Compound Mooney values for compositions 6, 7 and CB25 were also determined after sample preparation by the same operator on the same day. After preparation of stage 2 formulations, vulcanization was started by heating the stage 2 formulations at 160° C. for 20 minutes.

(46) TABLE-US-00004 TABLE 4 Polymer Compositions 1, 2 and 3 using polymers obtained in examples 1, 2 and 3, respectively Components Amount (phr).sup.n SSBR (solution made styrene VSL5025-OHM.sup.m 60.0 butadiene copolymer) Polymer 1, 2 or 3 (High cis- 40.0 polybutadiene) Precipitated silica Ultrasil 7000GR.sup.f 80.0 Silane NXT.sup.f,i 9.7 Stearic acid.sup.j 1.0 Stabilizer system: Ozone protecting wax Antilux 654.sup.h 1.5 Antiozonant Dusantox.sup.g 6PPD 2.0 Zinc oxide.sup.k 2.5 Softener (Oil) TDAE.sup.e 20.0 Sulfur.sup.d,l 1.4 TBBS.sup.b,d 1.5 DPG.sup.c,d 1.5 .sup.a2 stage mixing, Brabender 350S, Internal Banbury mixer .sup.bN-t-butyl-2-benzothiazolsulfenamide, Santocure-TBBS, Flexsys Inc. .sup.cDiphenylguanidine, Vulkacit D, Lanxess AG .sup.dSecond stage (curing system) .sup.eVivaTec 500, Hansen & Rosenthal KG .sup.fEvonic AG .sup.gN-(1,3-dimethylbutyl)-N′-phenyl-1,4-benzenediamine, Duslo a.s. .sup.hLight & ozone protective wax, Rhein Chemie Rheinau GmbH .sup.iMomentive .sup.jCognis GmbH .sup.kGrillo-Zinkoxid GmbH .sup.lSolvay AG .sup.mLanxess AG .sup.nBased on sum weight of the styrene butadiene copolymer and elastomeric diene polymer

(47) TABLE-US-00005 TABLE 5 Polymer Compositions 4, 5, 6, 7 and CB25_silica using polymers obtained in examples 4, 5, 6 and 7 or CB25, respectively Components Amount (phr).sup.n SSBR (solution made styrene ZA28-X1Sprintan(R) 60.0 butadiene copolymer) SLR-4602 - Schkopau.sup.m Polymer 4, 5, 6, 7 or CB25 40.0 (High cis-polybutadiene) Precipitated silica Ultrasil 7000GR.sup.f 80.0 Silane Si 75.sup.f,i 6.9 Stearic acid.sup.j 1.0 Stabilizer system: Ozone protecting wax Antilux 654.sup.h 1.5 Antiozonant Dusantox.sup.g 6PPD 2.0 Zinc oxide.sup.k 2.5 Softener (Oil) TDAE.sup.e 20.0 Sulfur.sup.d,l 1.4 TBBS.sup.b,d 1.5 DPG.sup.c,d 1.5 .sup.a2 stage mixing, Brabender 350S, Internal Banbury mixer .sup.bN-t-butyl-2-benzothiazolsulfenamide, Santocure-TBBS, Flexsys Inc. .sup.cDiphenylguanidine, Vulkacit D, Lanxess AG .sup.dSecond stage (curing system) .sup.eVivaTec 500, Hansen & Rosenthal KG .sup.fEvonic AG .sup.gN-(1,3-dimethylbutyl)-N′-phenyl-1,4-benzenediamine, Duslo a.s. .sup.hLight & ozone protective wax, Rhein Chemie Rheinau GmbH .sup.iBis(triethoxysilylpropyl)disulfan, sulfur equivalents per molecule: 2.35 .sup.jCognis GmbH .sup.kGrillo-Zinkoxid GmbH .sup.lSolvay AG .sup.mStyron Deutschland GmbH .sup.nBased on sum weight of the styrene butadiene copolymer and elastomeric diene polymer

(48) TABLE-US-00006 TABLE 6 Polymer Compositions 5A, 8, 9, 10 and CB25_carbon black using polymers obtained in examples 5, 8, 9 and 10 or CB25, respectively Amount Components (phr).sup.h Polymer 5, 8, 9, 10 or CB25 100 (High cis-polybutadiene) IRB 7 international ref. 50 carbon black, Sid Richardson Stearic acid.sup.e 1.5 Zinc Oxide.sup.f 3.0 Softener (Aromatic Oil) TDAE.sup.d 5.0 Sulfur.sup.c,g 1.75 TBBS.sup.c,d 1.0 .sup.a2 stage mixing, Brabender 350S, Internal Banbury mixer .sup.bN-t-butyl-2-benzothiazolsulfenamide, Santocure-TBBS, Flexsys Inc. .sup.cSecond stage (curing system) .sup.dVivaTec 500, Hansen & Rosenthal KG .sup.eCognis GmbH .sup.fGrillo-Zinkoxid GmbH .sup.gSolvay AG .sup.hBased on weight of the elastomeric diene polymer

(49) The compositions thus prepared were evaluated after vulcanization to give properties as disclosed in tables 9 and 11.

(50) TABLE-US-00007 TABLE 8 Compound Mooney of Polymer compositions (“stage 2 formulations”) Compound Polymer Mooney Compound Mooney - Composition [Mu] Mooney Polymer 1 54.2 10.6 2 47.6 2.1 3 47.5 −0.1 4 51.2 9.4 5 74.6 31.0 6 78.9 38.3 7 91.2 44.6 CB25 95.3 49.3

(51) TABLE-US-00008 TABLE 9 Silica Containing Polymer Vulcanizate Composition Properties (“Stage 2 formulations” after vulcanization) DIN Abrasion Elongation Tensile Modulus 0.5 kg load at Break Strength 300 Tan δ Tan δ Tan δ Example [mm] [%] [MPa] [MPa] at −10° C. at 0° C. at 60° C. 4 86 410 17.8 11.0 0.286 0.229 0.107 5 80 409 17.4 10.9 0.279 0.228 0.114 6 95 449 18.2 10.1 0.287 0.232 0.117 7 82 436 18.6 10.9 0.263 0.221 0.112 CB25 95 400 18.2 11.1 0.255 0.225 0.116

(52) TABLE-US-00009 TABLE 10 Compound Mooney of Polymer Compositions (“Stage 2 Formulations”) Polymer Compound Mooney Compound Composition [Mu] Mooney - Mooney Polymer 5A 65.2 21.6 CB25_carbon 73.9 28.1 black  8 62.5 21.3  9 62.5 20.7 10 61.6 21.6

(53) TABLE-US-00010 TABLE 11 Carbon Black Containing Polymer Vulcanizate Composition Properties (“Stage 2 formulations” after vulcanization) DIN Abrasion Elongation Tensile Modulus 0.5 kg load at Break Strength 300 Tan δ Tan δ Tan δ Example [mm] [%] [MPa] [MPa] at −10° C. at 0° C. at 60° C. 5A 20 477 17.7 9.5 0.149 0.142 0.117 CB25_Carbon 20 470 19.8 11.1 0.139 0.133 0.112 black 8 20 453 16.9 9.7 0.148 0.141 0.120 9 20 415 15.5 10.0 0.147 0.142 0.118 10 19 468 17.1 9.6 0.151 0.146 0.121

(54) Polymer compositions 2 and 3 show lower Compound Mooney values as compared to polymer composition 1 (table 8). Since the mooney viscosity values of the corresponding polymers that were used for the preparation of polymer compositions 1, 2 and 3 are similar (see table 2), the difference of “Compound Mooney” (indicated in Table 8) and “Mooney Polymer” (indicated as Mooney viscosity [MU] in table 2), i.e. “Compound Mooney—Mooney Polymer” (herein also referred to as “delta Mooney”) is lower for polymer compositions 2 and 3 as compared to polymer composition 1 that makes use of the linear, non-branched reference polymer 1.

(55) Likewise, table 8 reveals lower delta Mooney values for polymer compositions 4, 5, 6 and 7 as compared to comparative composition CB25. At the same time, the examples according to the invention show comparable or even better vulcanizate composition properties as expressed in table 9.

(56) Similarly, carbon black containing polymer compositions 5A, 8, 9 and 10 show lower delta Mooney values as compared to reference composition CB25 Carbon black (table 10), and vulcanizate composition properties were again found to be comparable or better for the examples according to the invention (table 11).

(57) The process of the invention yields polymers with improved processing properties. Without wishing to be bound by theory, the inventors believe that the improved processing behavior is the result of a specific branching between the polymer chains. The experiments show, that the unique polymer properties are the result of first adding one or more alkoxysilane compounds and then, subsequently, adding a thio compound to the reaction mixture derived from process step i).