Claims:1) A Process for preparing polybutadiene rubber, wherein said process comprising polymerization of butadiene in the presence of organocobalt salt, alkyl halo aluminium component and chain terminating agent.
2) A process for preparing polybutadiene rubber, wherein said process comprising the steps:
- adding dried solvent into a reactor followed by purging with inert gas;
- adding co-catalyst followed by addition of cobalt catalyst to the dried solvent containing reactor to obtain mixture -I;
- adding chain transfer agent to the mixture I to obtain mixture-II; and
- adding butadiene monomer to the mixture-III to obtain polybutadiene rubber mixture.
3) The process as claimed in claims 1 and 2, further comprising the step of coagulation of polymer from solvent medium by adding polar solvent(s).
4) The process as claimed in claim 1, wherein the polybutadiene rubber is selected from a group comprising l,4-polybutadiene rubber, high cis -l,4-polybutadiene rubber, low cis -l,4-polybutadiene rubber, trans -l,4-polybutadiene rubber, and combination thereof.
5) The process as claimed in claim 1, wherein the polybutadiene rubber is selected from a group comprising l,4-polybutadiene rubber, high linear-l,4-polybutadiene rubber and combinations thereof.
6) The process as claimed in claim 1, wherein the polybutadiene rubber is l,4-polybutadiene rubber with high solution viscosity
7) The process as claimed in claim 1, wherein the polybutadiene rubber is selected from a group comprising l,4-polybutadiene rubber with improved physical properties such as high tensile strength.
8) The process as claimed in claim 1, wherein the butadiene is selected from a group comprising 1,3-butadiene, cis-1,3-butadiene, 1,2 butadiene, and combination thereof.
9) The process as claimed in claim 1, wherein the organocobalt salt is cobalt octanoate.
10) The process as claimed in claim 1, wherein the alkyl halo aluminium component is selected from a group comprising alkyl chloro aluminium component, diethyl aluminium chloride, methyl aluminoxane, triisobutyl aluminium and combination thereof.
11) The process as claimed in claim 1, wherein the alkyl chloro aluminium component is selected from a group comprising chloroethyl aluminoxane, diethyl aluminium chloride, methyl aluminoxane, triisobutyl aluminium, and combination thereof.
12) The process as claimed in claim 1, wherein the chain terminating agent is selected from a group comprising butadiene, 1,2 butadiene, and combination thereof.
13) A process for preparing cis-polybutadiene rubber, wherein said process comprising the steps:
- adding dried benzene into a reactor followed by purging with nitrogen gas;
- adding alkyl halo aluminium component followed by Cobalt octanoate to the dried solvent containing reactor to obtain mixture -I;
- adding 1,2-butadiene to the mixture I to obtain mixture-II; and
- adding 1, 3-butadiene monomer to the mixture-III to obtain cis-polybutadiene rubber mixture.
14) The process as claimed in claim 1, wherein the concentration of organocobalt salt ranges from 1 x 10-5 to 2 x 10-5 mole per mole of 1,3-butadiene.
15) The process as claimed in claim 1, wherein the concentration of alkyl halo aluminium component in an ratio amount of 155 per mole of organocobalt salt.
16) The process as claimed in claim 1, wherein the concentration of chain terminating agent ranges from an amount of 1 to 100 ppm per 100 g of butadiene.
17) The process as claimed in claim 1, wherein the process is carried out at temperature ranging from 10 to 50 ? preferably 20 to 35 ?.
18) The process as claimed in claim 1, wherein the process is carried out at temperature ranging from 10 to 30? preferably 15 to 25 ?.
19) The process as claimed in claim 1, wherein the concentration of the monomer ranges from 10 to 60 wt % of the dry feed more precisely 20 to 30 wt%.
20) The process as claimed in claim 1, wherein the process is carried for a time period ranging from 10 minutes to 300 minutes, preferably for a time period ranging from 20 minutes to 60 minutes.
21) The process as claimed in claim 1, wherein the process is carried out in presence of a solvent, wherein the solvent is at least one or mixture of aromatic and non-aromatic solvent with C6 units.
22) The process as claimed in claim 1, wherein the coagulation of polymer from the solvent medium is carried using polar solvents.
23) The process as claimed in claim 1, wherein said polar solvent is selected from a group comprising water, alcohol containing C1 to C5 chain units and combinations thereof.
24) The catalyst composition for preparing cis-polybutadiene rubber with narrow molecular weight and with high molecular weight with lower branching, wherein said composition comprising organocobalt salt, alkyl chloro aluminium component, chain terminating agent.
Dated this 5th day of March 2021
Signature:
Name: Durgesh Mukharya
To: Of K&S Partners, Bangalore
The Controller of Patents Agent for the Applicant
The Patent Office, at Mumbai IN/PA-1541
, Description:TECHNICAL FIELD
[001]. The present disclosure is in the chemical sciences and material sciences. The present disclosure generally relates to a process for preparing polybutadiene rubber by employing a composition comprising co-catalyst as active species without water as activator. In particular, the disclosure relates to a process for preparing cobalt-based polybutadiene rubber with specific microstructure configuration by employing chloroethylalumioxane as a co-catalyst which is active species. Thus, the disclosure relates to a process for butadiene polymerization and improvement in the resultant product properties like high cis content, lower gel content and high linearity with improved physical product properties.

BACKGROUND OF THE DISCLOSURE
[002]. Butadiene Rubber (BR) is a synthetic rubber prepared by solution polymerization method using butadiene monomer. BR is widely used for tires, shoes and golf balls due to its excellent wear resistance, bend resistance, rebound resilience and cold resistance. Properties of polydienes mainly governed by their microstructures generated during polymerization process. BR is typically categorized according to the polymerization technology and an initiator or a catalyst used during the process of preparation.
[003]. PBR grades can be categorized based on method of preparation, viz., radical polymerization using emulsion method, anionic polymerization using lithium catalyst and coordination polymerization using transition metal-based Ziegler-Natta catalyst system.
[004]. Amongst above methods PBR synthesis using cobalt based catalyst system has received considerable attention due to control over molecular structure and other physical properties of resultant polymer.
[005]. During polymerization process cross linking of chains takes place results in gel formation and is non-desirable component of the process. Such gel formation can reduce the efficiency of the process mainly by disturbing smoothness of hardware operations and the quality of polybutadiene rubber is reduced. It is believed that one of the components, water in this catalyst system is found to disperse non uniformly in the organic solvent medium thus uneven activation of co-catalyst and catalyst system. This leads to rapid cross linking in polymer back bone resulting in gel formation.
[006]. Accordingly, there has been a continuing need in the art to provide compositions or process which could provide cis-polybutadiene rubber with narrow molecular weight and with high molecular weight with lower branching.
[007]. BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES
[008]. The novel features and characteristics of the disclosure are set forth in the appended description. The disclosure itself, however, as well as a preferred mode of use, further objectives, and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying figures. One or more embodiments are now described, by way of example only, with reference to the accompanying figures wherein like reference numerals represent like elements and in which:
[009]. Figure 1 shows NMR analysis of CEAO-PBR with cis 99 %, trans 0.6 %, vinyl 0.4 %
[0010]. Figure 2 shows NMR analysis of Commercial PBR with cis 97.1 %, trans 1,8 %, vinyl 1,2 %

DESCRIPTION OF THE DISCLOSURE
[0011]. The present disclosure aims to overcome the aforesaid drawbacks by providing an efficient process or composition(s) comprising organocobalt salt, alkyl halo aluminium component and chain terminating agent.

[0012]. In an embodiment, the present disclosure includes a process for preparing polybutadiene rubber, wherein said process comprising polymerization of butadiene in the presence of organocobalt salt, alkyl halo aluminium component and chain terminating agent.

[0013]. The present disclosure relates to a process for preparing polybutadiene rubber, wherein said process comprising the steps:
- adding dried solvent into a reactor followed by purging with inert gas;
- adding co-catalyst followed by addition of cobalt catalyst to the dried solvent containing reactor to obtain mixture -I;
- adding chain transfer agent to the mixture I to obtain mixture-II; and
- adding butadiene monomer to the mixture-III to obtain polybutadiene rubber mixture.
[0014]. In a non-limiting embodiment of the present disclosure, the above process further comprising the step of coagulation of polymer from solvent medium by adding polar solvent(s).
[0015]. In a non-limiting embodiment of the present disclosure, wherein the polybutadiene rubber is selected from a group comprising l,4-polybutadiene rubber, high cis -l,4-polybutadiene rubber, low cis 1,4 polybutadiene, high trans-1,4 polybutadiene and combination thereof.
[0016]. In a non-limiting embodiment of the present disclosure, wherein the polybutadiene rubber is selected from a group comprising l,4-polybutadiene rubber with high linearity compared to standard DEAC (diethyl aluminium chloride) process and combination thereof,
[0017]. non-limiting embodiment of the present disclosure, wherein the polybutadiene rubber is selected from a group comprising l,3-polybutadiene rubber has high solution viscosity
[0018]. non-limiting embodiment of the present disclosure, wherein the polybutadiene rubber is selected from a group comprising l,3-polybutadiene rubber with improved physical properties of high tensile strength.
[0019]. In a non-limiting embodiment of the present disclosure, wherein the butadiene is 1,3-butadiene.
[0020]. In a non-limiting embodiment of the present disclosure, the organocobalt salt is Cobalt octanoate and combination thereof.
[0021]. In a non-limiting embodiment of the present disclosure, the alkyl halo aluminium component is selected from a group comprising alkyl chloro aluminium component, diethyl aluminum chloride , methyl aluminoxane, triisobutyl aluminium, and combination thereof.
[0022]. In a non-limiting embodiment of the present disclosure, the alkyl chloro aluminium component is selected from a group comprising chloroethyl aluminoxane, diethyl aluminium chloride, methyl aluminoxane, triisobutyl aluminium, and combination thereof.
[0023]. In a non-limiting embodiment of the present disclosure, the chain terminating agent is butadiene, 1,2 butadiene, and combination thereof.
[0024]. In a non-limiting embodiment of the present disclosure, the concentration of organocobalt salt ranges from 1 x 10-5 to 2 x 10-5 mole per mole of 1,3 butadiene.
[0025]. In a non-limiting embodiment of the present disclosure, the concentration of alkyl halo aluminium component in ratio amount of 155 per mole of organocobalt salt.
[0026]. In a non-limiting embodiment of the present disclosure, the concentration of chain terminating agent ranges from an amount of 1 to 100 ppm per 100 g of butadiene.
[0027]. In a non-limiting embodiment of the present disclosure, the process is carried out at temperature ranging from 10 to 50 ? preferably 20 to 35 ?.
[0028]. In a non-limiting embodiment of the present disclosure, the process is carried out at temperature ranging from 10 to 30? preferably 15 to 25 ?.
[0029]. In a non-limiting embodiment of the present disclosure, the concentration of monomer ranges from 10 to 60 wt % of the dry feed more precisely 20 to 30 wt%.
[0030]. In a non-limiting embodiment of the present disclosure, the process is carried for a time period ranging from 10 minutes to 300 minutes, preferably for a time period ranging from 20 minutes to 60 minutes.
[0031]. In a non-limiting embodiment of the present disclosure, the process is carried out in presence of a solvent, wherein the solvent is at least one or mixture of aromatic and non-aromatic solvent with C6 units.
[0032]. In a non-limiting embodiment of the present disclosure, the coagulation of polymer from the solvent medium is carried using polar solvents.
[0033]. In a non-limiting embodiment of the present disclosure, a polar solvent is selected from a group comprising water, alcohol containing C1 to C5 chain units and combinations thereof.
[0034]. The present disclosure also provides a catalyst composition for preparing cis-polybutadiene rubber with narrow molecular weight and with high molecular weight with lower branching, wherein said composition comprising organocobalt salt, alkyl chloro aluminium component, chain terminating agent.
[0035]. In a non-limiting embodiment of the present disclosure, wherein the polybutadiene rubber is selected from a group comprising l,4-polybutadiene rubber, high cis -l,4-polybutadiene rubber, _low cis-l,4-polybutadiene rubber, high trans -l,4-polybutadiene rubber, and combination thereof.
[0036]. In a non-limiting embodiment of the present disclosure, wherein the butadiene is selected from a group comprising 1,3-butadiene, cis-1,3-butadiene, 1,2-butadiene and combination thereof.
[0037]. In a non-limiting embodiment of the present disclosure, the organocobalt salt is cobalt octanoate.
[0038]. In a non-limiting embodiment of the present disclosure, the alkyl halo aluminium component is selected from a group comprising alkyl chloro aluminium component, diethyl alumiunium chloride, methyl aluminoxane, triisobutyl aluminium, and combination thereof.
[0039]. In a non-limiting embodiment of the present disclosure, the alkyl chloro aluminium component is selected from a group comprising chloroethyl aluminoxane, diethyl aluminium chloride, methyl aluminoxane, triisobutyl aluminium, and combination thereof.
[0040]. In a non-limiting embodiment of the present disclosure, the chain terminating agent is selected from a group comprising butadiene, 1,2 butadiene, and combination thereof.
[0041]. In a non-limiting embodiment of the present disclosure, a composition comprises about 0.5% wt/wt to 50% wt/wt of organocobalt salt, about 0.5% wt/wt to 50% wt/wt of alkyl chloro aluminium component; and about 1 ppm to 1 % chain terminating agent.
[0042]. In a non-limiting embodiment of the present disclosure, a composition comprises about 1 %wt/wt to 20 %wt/wt of organocobalt salt, about 1 %wt/wt to 30 %wt/wt of alkyl chloro aluminium component; and about 1 %wt/wt to 100 %wt/wt chain terminating agent.
[0043]. The present disclosure provides process for preparing cis-polybutadiene rubber, wherein said process comprising the steps:
- adding dried benzene into a reactor followed by purging with nitrogen gas;
- adding alkyl halo aluminium component followed by Cobalt octanoate to the dried solvent containing reactor to obtain mixture -I;
- adding 1,2-butadiene to the mixture I to obtain mixture-II; and
- adding 1, 3-butadiene monomer to the mixture-III to obtain cis-polybutadiene rubber mixture.
- wherein the concentration of organocobalt salt ranges from 1 x 10-5 to 2 x 10-5 mole per mole of 1,3-butadiene.
[0044]. In a non-limiting embodiment of the present disclosure, the concentration of alkyl halo aluminium component in ratio amount of 155 per mole of organocobalt salt.
[0045]. In a non-limiting embodiment of the present disclosure, the concentration of chain terminating agent ranges from an amount of 1 to 100 ppm per 100 g of butadiene.
[0046]. In a non-limiting embodiment of the present disclosure, the reaction is carried out at temperature ranging from 10 to 50 ? preferably 20 to 35 ?.
[0047]. In a non-limiting embodiment of the present disclosure, the reaction is carried out at temperature ranging from 10 to 30? preferably 15 to 25 ?.
[0048]. In a non-limiting embodiment of the present disclosure, the concentration of monomer ranges from 10 to 60 wt % of the dry feed more precisely 20 to 30 wt%.
[0049]. In a non-limiting embodiment of the present disclosure, the process is carried for a time period ranging from 10 minutes to 300 minutes, preferably for a time period ranging from 20 minutes to 60 minutes.
[0050]. In a non-limiting embodiment of the present disclosure, the process is carried out in presence of a solvent, wherein the solvent is at least one or mixture of aromatic and non-aromatic solvent with C6 units.
[0051]. In a non-limiting embodiment of the present disclosure, the coagulation of polymer from the solvent medium is carried using polar solvents.
[0052]. In a non-limiting embodiment of the present disclosure, a polar solvent is selected from a group comprising water, alcohol containing C1 to C5 chain units and combinations thereof.
[0053]. The present disclosure also provides a catalyst composition for preparing cis-polybutadiene rubber with narrow molecular weight and with high molecular weight with lower branching, wherein said composition comprising organocobalt salt, alkyl chloro aluminium component, chain terminating agent.
[0054]. In a non-limiting embodiment of the present disclosure, wherein the polybutadiene rubber is selected from a group comprising l,4-polybutadiene rubber, high cis -l,4-polybutadiene rubber, _low cis-l,4-polybutadiene rubber, high trans -l,4-polybutadiene rubber, and combination thereof.
[0055]. In a non-limiting embodiment of the present disclosure, wherein the butadiene is selected from a group comprising 1,3-butadiene, cis-1,3-butadiene, 1,2-butadiene and combination thereof.
[0056]. In a non-limiting embodiment of the present disclosure, the PBR product obtained in the present invention has high linearity and low gel content.
[0057]. The process disclosed in the present application reduces gel content in the polymerization process thus improving the smooth operation of plant as well as superior grade PBR product.
[0058]. In an embodiment, the foregoing descriptive matter is illustrative of the disclosure and not a limitation. While considerable emphasis has been placed herein on the particular features of this disclosure, it will be appreciated that various modifications can be made, and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. Those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
[0059]. Additional embodiments and features of the present disclosure will be apparent to one of ordinary skill in art based upon description provided herein. The embodiments herein provide various features and advantageous details thereof in the description. Descriptions of well-known/conventional methods/steps and techniques are omitted so as to not unnecessarily obscure the embodiments herein. Further, the disclosure herein provides for examples illustrating the above described embodiments, and in order to illustrate the embodiments of the present disclosure certain aspects have been employed. The examples used herein for such illustration are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the following examples should not be construed as limiting the scope of the embodiments herein.

EXAMPLES:
[0060]. EXAMPLE 1:
[0061]. A composition comprising organocobalt salt, alkyl chloro aluminium component ; and chain terminating agent.

[0062]. EXAMPLE 2:
[0063]. A composition comprising organocobalt salt 0.5 to 50 wt.wt %, alkyl chloro aluminium component 0.5 to 30 wt/wt %; and chain terminating agent 1 to 100 ppm.

[0064]. EXAMPLE 3:
[0065]. A composition comprising cobalt octanoate , chloroethyl aluminoxane (CEAO) and 1,2 butadiene.

[0066]. EXAMPLE 4:
[0067]. A composition comprising cobalt octanoate at a concentration ranging from about 1 to 100 ppm, CEAO at a concentration ranging from about 50 to 500 ppm; and 1,2 butadiene at a concentration ranging from about 1 to 100 ppm.

[0068]. EXAMPLE 5: General process for preparing high cis-polybutadiene rubber:
Polybutadiene polymerization was prepared in solution polymerization technique and using benzene as solvent. Benzene was dried over molecular sieves overnight prior to experiment. Moisture content to be kept as low as 30 – 50 ppm which was measured by Karl Fisher titration method.

Dry solvent was charged to reactor vessel by means of nitrogen pressure in order to prevent any atmospheric moisture exposure. Solvent was purged with nitrogen in the reactor prior to begin polymerization. Co-catalyst containing alkyl halo aluminium component was charged in dilute form (7%) followed by organic ester based cobalt salts as catalyst in solvent (5%). Reaction mixture was subjected to stirring followed by addition of 1,2 butadiene as chain transfer agent [Chain transfer agent contributes in terminating growing chain after specific growth of chain length], and then by the addition of 1,3 butadiene. Reaction initiation was indicated by exothermicity in the reaction and reaction was performed for 1-2 hours. Reaction was terminated by adding polar solvent to reaction mixture and polymer was coagulated using polar solvent. Polymer was dried in vacuum oven and weighed.
EXAMPLE 6: Specific process for preparing high cis-polybutadiene rubber: In a typical reaction condition, benzene dried over molecular sieves was taken in glass reactor as a solvent, to which chloroethyl aluminoxane was added and the mixture is stirred for 5 mins. A catalyst Cobalt octanoate is added to the above mixture and allowed to react for 10 mins. 1,2 butadiene was added as a chain transfer/terminating agent and the reaction was initiated by adding 1,3 butadiene as monomer at 25 oC. Reaction temperature is controlled by using oil circulator. Reaction was allowed to proceed for 60 mins and methanol was used to quench the reaction followed by coagulation with methanol and dried under vacuum to get high cis-polybutadiene rubber.

[0069]. EXAMPLE 7: Specific Application of Composition: Halogen based aluminoxane reagents mentioned are important component in preparing high cis polybtudiene rubber with higher linearity. Such rubber products find application in high performance tyre due to improved product properties.

Table 1: Reaction conditions and composition of experiments performed. Polybutadiene rubber synthesis performed by two methods, a. conventional method by utilizing DEAC-water system as co-catalyst; b. halogen based aluminoxane –CEAO co-catalyst system. Polymerization process conducted with general procedure mentioned in earlier section with below shown components.
Experimental Data
Units a. DEAC-PBR b. CEAO-PBR
Total Volume mL 1200 1200
Benzene mL 1000 1000
Co Octonate ppm
15
15

Co-catalyst ppm
DEAC
160
CEAO
160
1,3-butadiene g 200 200
1,2-butadiene ppm
100
100
Initial temp oC 26 27
Pressure bar 1.5 1.5
Quenching Methanol (ml) 4 4

Table 2: Microstructural analysis of PBR product
a. Gel content
Commercial PBR DEAC-PBR CEAO-PBR
Gel (%) 0.4 1.4 0.24

From the above provided Gel content analysis, it is evident that the gel content of CEAO-PBR is less than that of commercial PBR and DEAC-PBR.
b. Cis content & molecular weight analysis
Commercial PBR DEAC-PBR CEAO-PBR
%Cis 97.1 96.1 99.0
% Trans 1.8 1.5 0.6
% Vinyl 1.2 2.4 0.4
Mw (mol/g) 385868 346288 357442
From the above provided cis content analysis, it is evident that the cis content of CEAO-PBR is less than that of commercial PBR and DEAC-PBR.
c. Branching by RPA Studies: Higher value indicates higher linearity
Commercial PBR DEAC-PBR CEAO-PBR
RPA Molecular Weight Distribution (Frequency Sweep) [1/(TD @ 0.2 Hz- TD@32Hz)] 3.5 8.1
1.7

MW distribution pattern broad broad narrow
From the above provided RPA Studies, it is evident that the RPA Molecular Weight Distribution of CEAO-PBR is less than that of commercial PBR and DEAC-PBR.
d. Linearity study by Fluid Viscosity
Commercial PBR DEAC-PBR CEAO-PBR
Fluid Viscosity (cP) 134 122 282
From the above provided fluid viscosity Studies, it is evident that the fluid viscosity of CEAO-PBR is less than that of commercial PBR and DEAC-PBR.
Table 3: Rubber processing analysis and rheology studies of PBR
ASTM MIM Single stage
Ingredients Phr
Commercial PBR DEAC-PBR CEAO-PBR
PBR 100.0 100.0 100.0
IRB#8 60.0 60.0 60.0
ZNO 3.0 3.0 3.0
ST ACID 2.0 2.0 2.0
Napthanic Oil 15.0 15.0 15.0
TBBS 0.9 0.9 0.9
Sol S 1.5 1.5 1.5
Total 182.4 182.4 182.4
RPA STUDY
Commercial PBR DEAC-PBR CEAO-PBR
RPA Molecular Weight Distribution (Frequency Sweep) [1/(TD @ 0.2 Hz- TD@32Hz)] 3.5 8.1
1.7

MW distribution pattern broad broad narrow
RPA Long Chain Branching (Strain Sweep) [TD@1000%-TD@10%] 1.90
1.49
2.17

Chain linearity pattern Less linear less linear High linear
Fluid Viscosity (cP) 134 122 282
Rheology Study ( ODR 2000 ) (160°C/21min
Commercial Standard Lab Standard PBR 3
ML(dN-M) 9.9 8.27 7.14
MH(dN-M) 42.91 36.45 39.53
Ts1 (Min) 2.53 3.17 2.93
Ts2 (Min) 3.47 3.87 3.82
TC10 (Min) 4.28 4.2 4.33
TC25 (Min) 5.45 4.98 5.15
TC40 (Min) 6 5.59 5.72
TC50 (Min) 6.34 6.04 6.16
TC90 (Min) 9.11 9.6 9.88
Final Tq.(dN-M) 42.48 36.01 39.23
Cure Rate 5.85 4.92 5.34
Delta Tq.(dN-M) 33.01 28.18 32.39

From the above provided rubber processing analysis and rheology studies of PBR, it is evident that the CEAO-PBR is highly linear than that of commercial PBR and DEAC-PBR.
Table 4: Physical Properties
Physicals - Unaged ( Cured @145°C/35 min)
Commercial PBR DEAC-PBR CEAO-PBR
Mod @100% Elong. (MPa) 2.4 2.3 2.8
Mod @300% Elong.(MPa) 9.4 9.9 11.2
Tensile Strength ( MPa) 14.7 14.3 16.3
Elong @ Brk. (%) 369 400 419

From the above provided physical property Studies, it is evident that the CEAO-PBR has high tensile strength than that of commercial PBR and DEAC-PBR.
[0070]. EXAMPLE 9:
[0071]. The invention is further described by the following numbered paragraphs:
1) A Process for preparing polybutadiene rubber, wherein said process comprising polymerization of butadiene in the presence of organocobalt salt, alkyl halo aluminium component and chain terminating agent.
2) A process for preparing polybutadiene rubber, wherein said process comprising the steps:
- adding dried solvent into a reactor followed by purging with inert gas;
- adding co-catalyst followed by addition of cobalt catalyst to the dried solvent containing reactor to obtain mixture -I;
- adding chain transfer agent to the mixture I to obtain mixture-II; and
- adding butadiene monomer to the mixture-III to obtain polybutadiene rubber mixture.
3) The process of paragraphs 1 and 2, further comprising the step of coagulation of polymer from solvent medium by adding polar solvent(s).
4) The process of paragraph 1, wherein the polybutadiene rubber is selected from a group comprising l,4-polybutadiene rubber, high cis -l,4-polybutadiene rubber, low cis -l,4-polybutadiene rubber, trans -l,4-polybutadiene rubber, and combination thereof.
5) The process of paragraph 1, wherein the polybutadiene rubber is selected from a group comprising l,4-polybutadiene rubber, high linear-l,4-polybutadiene rubber and combinations thereof.
6) The process of paragraph 1, wherein the polybutadiene rubber is l,4-polybutadiene rubber with high solution viscosity.
7) The process of paragraph 1, wherein the polybutadiene rubber is selected from a group comprising l,4-polybutadiene rubber with improved physical properties such as high tensile strength.
8) The process of paragraph 1, wherein the butadiene is selected from a group comprising 1,3-butadiene, cis-1,3-butadiene, 1,2 butadiene, and combination thereof.
9) The process of paragraph 1, wherein the organocobalt salt is cobalt octanoate.
10) The process of paragraph 1, wherein the alkyl halo aluminium component is selected from a group comprising alkyl chloro aluminium component, diethyl aluminium chloride, methyl aluminoxane, triisobutyl aluminium and combination thereof.
11) The process of paragraph 1, wherein the alkyl chloro aluminium component is selected from a group comprising chloroethyl aluminoxane, diethyl aluminium chloride, methyl aluminoxane, triisobutyl aluminium, and combination thereof.
12) The process of paragraph 1, wherein the chain terminating agent is selected from a group comprising butadiene, 1,2 butadiene, and combination thereof.
13) A process for preparing cis-polybutadiene rubber, wherein said process comprising the steps:
- adding dried benzene into a reactor followed by purging with nitrogen gas;
- adding alkyl halo aluminium component followed by Cobalt octanoate to the dried solvent containing reactor to obtain mixture -I;
- adding 1,2-butadiene to the mixture I to obtain mixture-II; and
- adding 1, 3-butadiene monomer to the mixture-III to obtain cis-polybutadiene rubber mixture.
14) The process of paragraph 1, wherein the concentration of organocobalt salt ranges from 1 x 10-5 to 2 x 10-5 mole per mole of 1,3-butadiene.
15) The process of paragraph 1, wherein the concentration of alkyl halo aluminium component in an ratio amount of 155 per mole of organocobalt salt.
16) The process of paragraph 1, wherein the concentration of chain terminating agent ranges from an amount of 1 to 100 ppm per 100 g of butadiene.
17) The process of paragraph 1, wherein the process is carried out at temperature ranging from 10 to 50 ? preferably 20 to 35 ?.
18) The process of paragraph 1, wherein the process is carried out at temperature ranging from 10 to 30? preferably 15 to 25 ?.
19) The process of paragraph 1, wherein the concentration of the monomer ranges from 10 to 60 wt % of the dry feed more precisely 20 to 30 wt%.
20) The process of paragraph 1, wherein the process is carried for a time period ranging from 10 minutes to 300 minutes, preferably for a time period ranging from 20 minutes to 60 minutes.
21) The process of paragraph 1, wherein the process is carried out in presence of a solvent, wherein the solvent is at least one or mixture of aromatic and non-aromatic solvent with C6 units.
22) The process of paragraph 1, wherein the coagulation of polymer from the solvent medium is carried using polar solvents.
23) The process of paragraph 1, wherein said polar solvent is selected from a group comprising water, alcohol containing C1 to C5 chain units and combinations thereof.
24) The catalyst composition for preparing cis-polybutadiene rubber with narrow molecular weight and with high molecular weight with lower branching, wherein said composition comprising organocobalt salt, alkyl chloro aluminium component, chain terminating agent.

[0072]. Additional embodiments and features of the present disclosure will be apparent to one of ordinary skill in art based on the description provided herein. The embodiments herein provide various features and advantageous details thereof in the description. Descriptions of well-known/conventional methods and techniques are omitted so as to not unnecessarily obscure the embodiments herein.

[0073]. The foregoing description of the specific embodiments fully reveals the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments in this disclosure have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

[0074]. Throughout this specification, the word “comprise”, or variations such as “comprises” or “comprising” wherever used, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

[0075]. With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.

[0076]. Any discussion of documents, acts, materials, devices, articles and the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.

[0077]. While considerable emphasis has been placed herein on the particular features of this disclosure, it will be appreciated that various modifications can be made, and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other modifications in the nature of the disclosure or the preferred embodiments will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.