FORM 2
THE PATENTS ACT, 1970 (39 of 1970) & THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10, rule 13)
1. Title of the invention: AN IMPROVED PROCESS OF PREPARING AN ELASTOMER
COMPOSITE
2. Applicant(s)
NAME NATIONALITY ADDRESS
CEAT LIMITED Indian RPG HOUSE, 463, Dr. Annie
Besant Road, Worli, Mumbai -Maharashtra 400 030, India
3. Preamble to the description
COMPLETE SPECIFICATION
The following specification particularly describes the invention and the manner in which it
is to be performed.

The present Application is a Patent of Addition Application to the Parent Application no: 201921040613.
The present Application provides an improved process for preparing an elastomer composite, and the process enables ease of processing and ensures homogenous mixing of the components to obtain a homogenized elastomer composite.
FIELD OF INVENTION
[001] The present disclosure broadly relates to an elastomer composite and
particularly refers to a process of preparing an elastomer composite for masterbatch.
BACKGROUND OF INVENTION
[002] Elastomers, especially natural rubber latex, are subjected to multiple processing to convert it into bale or sheet form. During such processing, the polymer chains get degraded. Solid rubber is mixed with other solid ingredients in with shear intensive thermomechanical energy, which causes further degradation of the elastomer, resulting in deterioration of properties. Additionally, homogenous distribution of solid particles in solid rubber is difficult and the dispersion is very poor, which prohibits achieving good elastomer properties in final material obtained. [003] Handling powder materials like carbon black is difficult and tedious, which makes the entire production floor dirty. Therefore, most of the reported methods for the preparation of an elastomer composite, mentioned in literatures start with the preparation of a slurry of filler. In such processes acids are added at the final step to coagulate the rubber. However, acids de-accelerate the curing rate of rubber compound and deteriorate the rubber properties in long run. Also, the existing processes for the production of the rubber compound involves several process steps and hence is also expensive.
[004] As per the available literature method, a separate apparatus has been used for the preparation of carbon black dispersion, mixing of latex with carbon black dispersion and coagulation, and finally for drying which makes the process costly and cumbersome. Accordingly, there is dire need in the state of art for a process of

preparing an elastomer composite with minimal steps, less intensive which can retain the elastomer properties as well as should be energy and cost saving.
SUMMARY OF THE INVENTION
[005] In an aspect of the present disclosure, there is provided an improved process for preparing an elastomer composite, the process comprising: a) mixing at least one solid particulate with at least one elastomer in latex form in the presence of at least one surfactant in a mixer to obtain a first mix; and b) processing the first mix in an extruder to obtain the elastomer composite, wherein processing the first mix is carried out at a temperature in a range of 90 to 150℃.
[006] In another aspect of the present disclosure, there is provided a formulation comprising: a) the elastomer composite prepared by the process as disclosed herein; and b) at least one additive selected from fillers, activators, accelerators, antioxidant, antiozonant, peptizer, processing aid, retarder, or combinations thereof. [007] These and other features, aspects, and advantages of the present subject matter will be better understood with reference to the following description and appended claims. This summary is provided to introduce a selection of concepts in a simplified form. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
DETAILED DESCRIPTION OF THE INVENTION
[008] Those skilled in the art will be aware that the present disclosure is subject to variations and modifications other than those specifically described. It is to be understood that the present disclosure includes all such variations and modifications. The disclosure also includes all such steps, features, compositions, and compounds referred to or indicated in this specification, individually or collectively, and any and all combinations of any or more of such steps or features. Definitions

[009] For convenience, before further description of the present disclosure, certain
terms employed in the specification, and examples are delineated here. These
definitions should be read in the light of the remainder of the disclosure and
understood as by a person of skill in the art. The terms used herein have the meanings
recognized and known to those of skill in the art, however, for convenience and
completeness, particular terms and their meanings are set forth below.
[0010] The articles “a”, “an” and “the” are used to refer to one or to more than one
(i.e., to at least one) of the grammatical object of the article.
[0011] The terms “comprise” and “comprising” are used in the inclusive, open sense,
meaning that additional elements may be included. It is not intended to be construed
as “consists of only”.
[0012] Throughout this specification, unless the context requires otherwise the word
“comprise”, and variations such as “comprises” and “comprising”, will be
understood to imply the inclusion of a stated element or step or group of element or
steps but not the exclusion of any other element or step or group of element or steps.
[0013] The term “including” is used to mean “including but not limited to”.
“Including” and “including but not limited to” are used interchangeably.
[0014] The term “phr” used herein refers to parts per hundred rubber/resin. It is a
unit well defined in the field of rubber technology to define the amount of ingredients
used. The unit “phr” can also be interchangeably used with the unit “gram” as both
denote phr/gram of ingredient per 100 phr/gram of rubber.
[0015] The term “rpm” used herein refers to rotations/revolutions per minute. It is a
unit well used in the field of rubber technology to define the speed of any rotating
part of the machine, in this disclosure especially for co-rotating twin screw extruder
(CRTSE).
[0016] The term “at least one elastomer” or “at least one elastomer in latex form”
used herein refers to an elastic polymer in the form of latex or dispersion or solution.
Examples include, but are not limited to, natural rubber, styrene butadiene rubber,
butadiene rubber, acrylonitrile butadiene rubber, chloroprene rubber, neoprene
rubber and the like. In the present disclosure, the at least one elastomer in latex form

is a natural rubber in latex form is obtained naturally from the latex (milky tree sap) derived from bark of trees.
[0017] The term “at least one solid particulate” used herein refers to particulate compound which act as a bulking agent and/ or as a filling material. The at least one solid particulate of the present disclosure includes but not limited to carbon black, silica, calcium carbonate, clay, or combinations thereof.
[0018] The term “mixer” used herein refers to a device or a machine which facilitates mixing of the components under set speed and the mixer enables complete and homogenous mixing of the components. The mixer used in the present disclosure refers to a “high speed mixer” used to mix at least one solid particulate with at least one elastomer in latex form in the presence of at least one surfactant to obtain a first mix.
[0019] The term “extruder” used herein refers to co-rotating twin screw extruder (CRTSE) comprises two screws which co-rotates and is useful for compounding, mixing, and processing of rubbers or elastomers. The process of preparing an elastomer composite involves the use of CRTSE which provides homogenous mixing of the components to form the elastomer composite. The CRTSE operates at a specific speed, wherein the processing of the first mix is carried out at a speed in a range of 100 to 1000 rpm, and preferably in a range of 300 to 600 rpm. [0020] The term “surfactant” used herein refers to chemical compounds which helps to reduce the surface tension of the components. The surfactants comprises hydrophobic and hydrophilic ends and hence are useful in blending components of varying polarities. The surfactants of the present disclosure include but are not limited to anionic, cationic and non-ionic surfactants. Examples of anionic surfactants include alkoxylated fatty alcohol ether sulphates or its salts, fatty acid salts, alkyl sulfates, alkyl benzene sulfonate, alkyl naphthalene sulfonate or its sodium salt, alkyl sulfosuccinate, alkyl diphenyl ether disulfonate, sodium 2-naphthalene sulfonate formaldehyde condensate, polycarboxylate polymer type surfactants, or combinations thereof. Examples of alkoxylated fatty alcohol ether sulphates include but not limited to sodium salt of alkoxylated fatty alcohol ether sulphate, preferably Disponil® FES. Examples of fatty acid salts include but not

limited to stearates, oleates, laurates, their salts and so on. Examples of alkyl sulfates
include but not limited to ammonium lauryl sulfate, sodium lauryl sulfates, sodium
lauryl ether sulfate, sodium myreth sulfates and so on. Examples of alkyl benzene
sulfonates include but not limited to linear alkyl benzene sulphonates, sodium
dodecylbenzenesulfonates, and so on. Alkyl sulfosuccinates are alkyl esters of
sulfosuccinic acids selected from compounds having Formula
NaO3SCH(CO2R')CH2CO2R where R and R' can be independently H or alkyl groups. Examples of alkyl diphenyl ether disulfonates include disodium alkyl diphenyl ether disulfonate, sodium dodecyl diphenyl ether disulfonate and so on. Polycarboxylate polymer type surfactants are polymers of carboxylic acids such as polymers of fatty acids, polymers of acrylic acid or copolymers of acrylic acid and maleic acid, copolymers consisting polyethylene oxides and polypropylene oxides, and so on. [0021] The term “filler” used in the present disclosure refer to a carbon black. Selection of the filler or mixture of fillers will depend largely upon the intended use of a product prepared from the elastomer masterbatch. As used herein, filler can include any material which is appropriate for use in the masterbatch process. Conventional fillers such as silica, clay, calcium carbonate, talc and other functional equivalents thereof are within the scope of the fillers of the present disclosure. [0022] The term “activator” used herein refers to the substances that have a strong activation effect of increasing the vulcanization speed in the cross-linking reaction of rubbers or elastomers. Activators are required to achieve the desired vulcanization and end-user properties.
[0023] The term “accelerator” used herein refers to the substances used with a cross-linking agent to increase the speed of vulcanization of rubber and enhance its physical properties. Examples of accelerators include but are not limited to N-cyclohexyl-2-benzothiazole sulfenamide.
[0024] The term “antioxidant” used herein refers to the substances that are used to protect rubber articles against the attack of oxygen. Examples of antioxidant include but not limited to N-(1,3-dimethylbutyl)-N'- phenyl-p-phenylenediamine (6PPD)

[0025] The term “antiozonant” used herein refers to the substances that prevent the degradation due to ozone cracking. Examples include ethylene di-urea, microcrystalline wax, and others.
[0026] The term “peptizer” used herein refers to the substances which break down polymer chains and reduce rubber viscosity during its processing. [0027] The term “processing aid” used herein refers to the substances which helps in rubber processing. Examples include, but are not limited to, wood rosin. [0028] The term “retarder” used herein refers to the substances added to rubber compounds to delay premature vulcanization during its processing. Examples include, but are not limited to, pre-vulcanization inhibitors (PVI), N-(cyclohexylthio) phthalimide (CTP).
[0029] The term “dry rubber content” used herein refers to the amount in grams of a rubber per 100 grams of the elastomer in latex form. In present disclosure, the elastomer has dry rubber content in a range of 20 to 70%, in turns refers to 20 to 70 grams of rubber in 100 grams elastomer in latex form.
[0030] The terms “composite”, “masterbatch” and “elastomer composite” have been used interchangeably throughout the specification.
[0031] Ratios, concentrations, amounts, and other numerical data may be presented herein in a range format. It is to be understood that such range format is used merely for convenience and brevity and should be interpreted flexibly to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. For example, a temperature range of about 90 ℃ - 150 ℃ should be interpreted to include not only the explicitly recited limits of about 100 ℃ to about 150 ℃, but also to include sub-ranges, such as 92 ℃, 100 ℃, 105 ℃, 110 ℃ and so forth, as well as individual amounts, including fractional amounts, within the specified ranges, such as 110.4 ℃, and 140.8 ℃, for example.
[0032] As discussed in the background, there is a need in the state of art for a simple yet efficient, cost sensitive process of industrial production of elastomer composite or rubber masterbatch for use in synthesizing rubber formulations. It is also

necessary that the masterbatches prepared should be homogenous, with no batch-to-batch variations. The existing process uses two feeders in loading the extruder which makes the elastomer composite preparation process cumbersome and challenging. Accordingly, the present disclosure provides a process of preparing an elastomer composite, the process comprising: obtaining a premix of at least solid particulate with at least one elastomer in latex form in the presence of a surfactant in a high¬speed mixer and feeding the obtained premix in an extruder for processing to obtain the elastomer composite. The present disclosure therefore avoids problems associated with use of two feeders in an extruder and utilizes only one feeder, thus making the process efficient and less cumbersome. Premixing is advantageous in multiple ways, such as avoids use of solvent in preparation of slurry, provides homogenous dispersion of solid particulate in elastomer and moreover helps in maintaining the production floor clean and tidy by avoiding the direct addition of solid particulates in powder form. Thus, the process of the present disclosure is an economically affordable process yet an efficient process of preparing an elastomer composite without any degradation in elastomer properties.
[0033] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the disclosure, the preferred methods, and materials are now described. All publications mentioned herein are incorporated herein by reference.
[0034] The present disclosure is not to be limited in scope by the specific embodiments described herein, which are intended for the purposes of exemplification only. Functionally-equivalent products, compositions, and methods are clearly within the scope of the disclosure, as described herein.
[0035] In an embodiment of the present disclosure, there is provided an improved process for preparing an elastomer composite, the process comprising: a) mixing at least one solid particulate with at least one elastomer in latex form in the presence of at least one surfactant in a mixer to obtain a first mix; and b) processing the first mix in an extruder to obtain the elastomer composite, wherein processing the first mix is

carried out at a temperature in a range of 90 to 150℃. In another embodiment of the present disclosure, processing the first mix is carried out at a temperature in a range of 100 to 130℃, preferably in a range of 110 to 130℃, and more preferably at 120℃. [0036] In an embodiment of the present disclosure, there is provided an improved process for preparing an elastomer composite as disclosed herein, wherein mixing at least one solid particulate with at least one elastomer in latex form in the presence of at least one surfactant in a mixer is carried out at a speed in a range of 200 to 800 rpm. In another embodiment of the present disclosure, mixing at least one solid particulate with at least one elastomer in latex form in the presence of at least one surfactant in a mixer is carried out at a speed in a range of 300 to 700 rpm, preferably at a speed of 500 rpm.
[0037] In an embodiment of the present disclosure, there is provided an improved process for preparing an elastomer composite as disclosed herein, wherein processing the first mix is followed by drying at a temperature in a range of 90 to 150℃. In another embodiment of the present disclosure, processing the first mix followed by drying is carried out at a temperature in a range of 95 to 120℃, preferably in a range of 100 to 110℃, and more preferably at 105℃. [0038] In an embodiment of the present disclosure, there is provided an improved process for preparing an elastomer composite as disclosed herein, wherein processing the first mix in an extruder is carried out at a speed in a range of 100 to 1000 rpm. In another embodiment of the present disclosure, processing the first mix in an extruder is carried out at a speed-in a range of 300 to 600 rpm. [0039] In an embodiment of the present disclosure, there is provided an improved process for preparing an elastomer composite as disclosed herein, wherein the elastomer, the solid particulate and the surfactant are in weight ratio range of 100:50:2 to 100:40:0.1.
[0040] In an embodiment of the present disclosure, there is provided an improved process for preparing an elastomer composite as disclosed herein, wherein the at least one solid particulate is selected from carbon black, silica, calcium carbonate, clay, or combinations thereof. In another embodiment of the present disclosure, the at least one solid particulate ingredient is in the form of powder or granules. In another

embodiment of the present disclosure, the at least one solid particulate is carbon black in powder form.
[0041] In an embodiment of the present disclosure, there is provided an improved process for preparing an elastomer composite as disclosed herein, wherein the at least one elastomer is selected from natural rubber, styrene butadiene rubber, butadiene rubber, acrylonitrile butadiene rubber, chloroprene rubber, neoprene rubber, or combinations thereof. In another embodiment of the present disclosure, the at least one elastomer is natural rubber.
[0042] In an embodiment of the present disclosure, there is provided an improved process for preparing an elastomer composite as disclosed herein, wherein the surfactant is selected from anionic, cationic, non-ionic surfactants or combinations thereof. In another embodiment the surfactant is an anionic surfactant selected from the anionic surfactant is selected from alkoxylated fatty alcohol ether sulphates, fatty acid salts, alkyl sulfates, alkyl benzene sulfonates, alkyl naphthalene sulfonates, alkyl sulfosuccinates, alkyl diphenyl ether disulfonates, sodium 2-naphthalene sulfonate formaldehyde condensates, polycarboxylate polymer type surfactants, or combinations thereof. In yet another embodiment of the present disclosure, the surfactant is sodium salt of alkoxylated fatty alcohol ether sulphate.
[0043] In an embodiment of the present disclosure, there is provided an improved process for preparing an elastomer composite, the process comprising: a) mixing at least one solid particulate with at least one elastomer in latex form in the presence of at least one surfactant in a mixer at a speed in a range of 200 to 800 rpm to obtain a first mix; and b) processing the first mix in an extruder followed by drying at a temperature in a range of 90 to 150℃ to obtain the elastomer composite, wherein processing the first mix is carried out at a temperature in a range of 90 to 150℃ and at a speed in a range of 100 to 1000 rpm; and the elastomer, the solid particulate and the surfactant are in weight ratio range of 100:50:2 to 100:40:0.1.
[0044] In an embodiment of the present disclosure, there is provided an improved process for preparing an elastomer composite, the process comprising: a) mixing at least one solid particulate with at least one elastomer in latex form in the presence of at least one surfactant in a mixer at a speed in a range of 200 to 800 rpm to obtain a

first mix; and b) processing the first mix in an extruder followed by drying at a temperature in a range of 90 to 150℃ for a time period in a range of 1 to 3 hours to obtain the elastomer composite, wherein processing the first mix is carried out at a temperature in a range of 90 to 150℃ for a time period in a range of 20 to 80 minutes and at a speed in a range of 100 to 1000 rpm; and the elastomer, the solid particulate and the surfactant are in weight ratio range of 100:50:2 to 100:40:0.1
[0045] In an embodiment of the present disclosure, there is provided an improved process for preparing an elastomer composite, the process comprising: a) mixing at least one solid particulate with at least one elastomer in latex form in the presence of at least one surfactant in a mixer at a speed of 500 rpm to obtain a first mix; and b) processing the first mix in an extruder followed by drying at a temperature of 105℃ to obtain the elastomer composite, wherein processing the first mix is carried out at a temperature of 120℃ and at a speed in a range of 300 to 600 rpm; and the elastomer, the solid particulate and the surfactant are in weight ratio range of 100:50:2 to 100:40:0.1.
[0046] In an embodiment of the present disclosure, there is provided an improved process for preparing an elastomer composite, the process comprising: a) mixing at least one solid particulate with at least one elastomer in latex form in the presence of at least one surfactant in a mixer at a speed of 500 rpm to obtain a first mix; and b) processing the first mix in an extruder followed by drying at a temperature of 105℃ for 2 hours to obtain the elastomer composite, wherein processing the first mix is carried out at a temperature of 120℃ for 60 minutes and at a speed in a range of 300 to 600 rpm; and the elastomer, the solid particulate and the surfactant are in weight ratio range of 100:50:2 to 100:40:0.1.
[0047] In an embodiment of the present disclosure, there is provided an improved process for preparing an elastomer composite as disclosed herein, wherein the elastomer has a dry rubber content (DRC) in the range of 20- 70%. In another embodiment of the present disclosure, the elastomer has a dry rubber content is about 60%.
[0048] In an embodiment of the present disclosure, there is provided an improved process for preparing an elastomer composite as disclosed herein, wherein the

extruder is a co-rotating twin screw extruder. In another embodiment of the present disclosure, wherein processing is carried out in co-rotating twin screw extruder (CRTSE) at kneading block percentage in the range of 10-60%. In one another embodiment of the present disclosure, processing is carried out in CRTSE, with an output of 50 kg/h. In yet another embodiment of the present disclosure, wherein processing is carried out in CRTSE having a screw diameter of 50 mm and L/D (length/diameter) ratio of 60.
[0049] In an embodiment of the present disclosure, there is provided a formulation comprising: a) an elastomer composite as obtained by process as disclosed herein; and b) at least one additive selected from fillers, activators, accelerators, antioxidant, antiozonant, peptizer, processing aid, retarder, or combinations thereof. [0050] In an embodiment of the present disclosure, there is provided a formulation comprising the elastomer composite prepared by the process as described herein, fillers, activators, accelerators, antioxidant, antiozonant, peptizer, processing aid, retarder, and combinations thereof, wherein the formulation is prepared in a Banbury mixer or intermix or Haake Rheomix OS mixer.
[0051] In an embodiment of the present disclosure, there is provided a formulation comprising: the elastomer composite comprising carbon black and natural rubber latex, sodium salt of alkoxylated fatty alcohol ether sulphate as surfactant, zinc oxide as fillers, combination of stearic acid and sulfur as activators, N-cyclohexyl-2-benzothiazole sulfenamide (CBS) as accelerators, N-(1,3-dimethylbutyl)-N'- phenyl-p-phenylenediamine (6PPD) as antioxidant, wax as antiozonant, and wood rosin as processing aid.
[0052] In an embodiment of the present disclosure, there is provided a formulation comprising the elastomer composite comprising carbon black and natural rubber latex, , sodium salt of alkoxylated fatty alcohol ether sulphate as surfactant, zinc oxide as fillers, combination of stearic acid and sulfur as activators, N-cyclohexyl-2-benzothiazole sulfenamide (CBS) as accelerators, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD) as antioxidant, wax as antiozonant, wood rosin as processing aid, and N-(cyclohexylthio) phthalimide (CTP) as retarder.

[0053] Although the subject matter has been described in considerable detail with reference to certain examples and implementations thereof, other implementations are possible.
EXAMPLES
[0054] The disclosure will now be illustrated with working examples, which are intended to illustrate the working of disclosure and not intended to take restrictively to imply any limitations on the scope of the present disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this disclosure belongs. Although methods and materials similar to or equivalent to those described herein can be used in the practice of the disclosed methods and compositions, the exemplary methods, devices, and materials are described herein. It is to be understood that this disclosure is not limited to particular methods, and experimental conditions described, as such methods and conditions may apply.
Abbreviations:
MDR: Moving Die Rheometer
DMTA: Dynamic mechanical thermal analysis
MOD: Modulus
Materials and Methods
[0055] Moisture content was measured using moisture analyzer (MA). CRTSE, Alpha 25 was procured from Steer Eng., India. Haake Rheomix OS mixer was procured from Thermo Fischer Scientific. Moving Die Rheometer, MDR 3000, MonTech, and Mooney viscosity (ML 1+4) at 100oC using Mooney Viscometer, VR-1132, Ueshima, Japan. Stress vs. strain and tear test was performed using Universal testing machine (UTM), Strograph AE, Toyoseiki. Hardness was measured using Durometer, MonTech. The tensile strength and elongation at break were measured in Zwick universal testing machine Z010 under DIN 53516 in S2 sample size cut from 2 mm sheets. The Shore A hardness was measured with respect to DIN 53516 with 6 mm vulcanized sheet under room temperature. The thickness of the sample 6 mm is made by cutting three 2 mm sheets.

EXAMPLE 1
Preparation of an elastomer composite
[0056] The process of preparation of the elastomer composite of the present disclosure is described herein. In an example, about 12.5 kg of carbon black (equivalent to 47.3 phr of carbon black per 100 phr of rubber), 1 kg of sodium salt of alkoxylated fatty alcohol ether sulphate (surfactant) and 44 kg of natural rubber latex having dry rubber content of 60% were mixed together in a high-speed mixer at speed of 500 rpm for about 60 minutes to obtain a first mix. The first mix was fed into a co-rotating twin screw extruder (50 mm screw diameter, L/D: 60) at an output of 50 kg/h at 120℃ with a screw speed of 500 rpm, followed by drying at 105℃ for 2 h in a hot air dryer to obtain the elastomer composite having moisture level <1%. [0057] The obtained elastomer composite was further used in the preparation of rubber formulations.
EXAMPLE 2
Preparation of formulation comprising the NR-N134 composite
[0058] Table 1 depicts 4 truck tire tread formulations prepared by mixing the present NR-N134 composite with the other formulation ingredients (as per recipe shown in Table 1). The mixing was done in Haake Rheomix OS mixer. Each compound (TC-1, TC-2, TC-3, and TC-4) comprised the same NR-N134 composite having 44 phr carbon black with 100 phr RSS4 natural rubber as shown in Example 1. Fill factor (FF) was of 68%. The rotor speed was maintained at 40 rpm and dumped at 105oC. To prepare the standard or control truck tire tread formulation, mixing was done in three steps; (i) preparation of masterbatch with rubber and other ingredients, except curatives, (ii) repass, (ii) final mixing with curatives. Further detailing of the process as follows:
Step 1: Preparation of masterbatch: At first, all rubbers/elastomers/NR-N134 MB were incorporated and mixed for 45 seconds at a speed of 60 rpm. Then half of all ingredients (except curative system- i.e., sulfur, accelerator) were incorporated and mixed again for 60 seconds at a speed of 60 rpm. After that, the remaining half of the ingredients were incorporated and mixed again for 45 seconds at a speed of 60

rpm. Finally, the mixing was continued for 340 seconds. At this stage, the rpm was varied to maintain the barrel temperature of the extruder at 150 ℃. Step 2: Repass: The masterbatch was kept overnight for relaxation. Next day, it was re-mixed for 210 seconds at 70 rpm. 5 Step 3: Final mixing with additives: The masterbatch and additives were incorporated and mixed for 200 seconds to obtain the vulcanization mix. At this stage, the temperature was maintained below 100 ℃ by controlling the mixing speed.

Component Control TC-1 TC-2 TC-3 TC-4
Natural rubber (NR) RSS4 100.00 - - - -
Carbon black powder N134 44.00 - - - -
NR-N134 - 144.00 144.00 144.00 144.00
Filler Zinc oxide 3.50 3.50 3.50 3.50 3.50
Activator Stearic acid 2.00 2.00 2.00 2.00 2.00

Sulfur 2.25 2.25 2.25 2.25 2.25
Anti-oxidant 6PPD 2.70 2.70 2.70 2.70 2.70
Antiozonant Wax 1.00 1.00 1.00 1.00 1.00
Processing aid Wood rosin 1.00 1.00 1.00 1.00 1.00
Accelerator CBS 0.75 0.75 0.75 0.75 0.75
Screw speed (rpm) in
elastomer composite
preparation as shown in
Example 1 500 1000 500 1000
Barrel temperature of the extruder 150℃ 150℃ 200℃ 200℃
Moisture content* (%) 2.2 2.4 1.4 1.6
*Moisture content was measured at 125oC for 10 minutes

[0059] The tread samples TC-1, TC-2, TC-3, and TC-4 comprising the NR-N134
composite were investigated for their mechanical properties using the rheometric test
at 140oC and Mooney viscosity (ML 1+4) at 100oC. The tensile, hardness and tear
testing samples were cured at 148oC for 30 minutes. For tensile strength and hardness
5 , five measurements were taken for each sample and the average was taken as the
final value. The results of the rheometric test are recorded in Table 2.

Properties Control TC-1 TC-2 TC-3 TC-4
Mooney viscosity (ML1+4) @100oC 87 96.4 115.8 95.7 105.9
Modulus 100% (kg/cm2) 28.2 26.6 29.3 25.3 24.9
Modulus 200% (kg/cm2) 78.3 68.3 79.9 70.3 67.5
Modulus 300% (kg/cm2) 152 136 158 142 139
Modulus 400% (kg/cm2) 232 214 241 221 220
Tensile strength (kg/cm2) 309.9 275.6 277.3 282.4 303.7
Elongation at break (%) 500.4 477 445.8 477.6 494.9
Hardness shore A 69.1 67.8 69.8 66.7 66.0
[0060] Mooney viscosity of the formulations comprising natural rubber-N134 masterbatch composites produced at lower screw speed (TC-1 and TC-3) was lower
10 than that of higher screw speed. So, based on Mooney viscosity requirement,
production parameter of NR-N134 masterbatch can be optimized. Modulus, tensile strength, elongation at break and hardness shore A properties of all the compounds were comparable. [0061] Another truck tire tread compound comprising NR-N115 masterbatch was
15 prepared to test the compatibility of the present process with other carbon black
grades. Control compounds with N134 and N115 carbon black were prepared for comparison purposes. Both NR-N134 MB and NR-N115 MB were prepared in accordance with the process of the present disclosure. Table 3 depicts the concentration in phr for each of the components present in the compound.
20 Table 3

Components Control A with N134 (phr) MB with N134 (phr) Control B with N115 (phr) MB with N115 (phr)
Natural rubber (NR) RSS4 100 - 100 -
Carbon black powder N134 44 - - -
Carbon black powder N115 44 -
NR Latex-carbon black masterbatch 144 - 144
Filler ZnO 3.50 3.50 3.50 3.50
Activator Stearic acid 2.00 2.00 2.00 2.00

Sulfur 2.00 2.00 2.00 2.00
Antioxidant 6PPD 2.00 2.00 2.00 2.00
Antiozonant Micro
crystalline
wax 1.00 1.00 1.00 1.00
Processing aid Wood rosin 1.00 1.00 1.00 1.00
Antioxidant TMQ 0.70 0.70 0.70 0.70
Accelerator CBS 0.75 0.75 0.75 0.75
Retarder CTP 0.25 0.25 0.25 0.25
[0062] The mechanical properties of the compounds were tested and the results are
depicted in Table 4. It could be observed that all the properties of the compounds
containing NR-N134 MB and NR-N115 MB are comparable with respect to their
controlled compounds. Hence, it was clear that no significant deterioration occurred
5 in the quality of the compounds on changing the carbon black grade.

Table 4
Property Control A with N134 LMB with N134 Control B with N115 LMB with N115
Specific gravity 1.0962 1.1026 1.0968 1.1170
ML (1 + 4) @100oC 61.3 63.7 57.5 93.0
ML 5 UP Mins @ 125°C 22.9 26.6 20.9 22.6

MDR @ 148°CX60'
ML (dN-m) 2.44 1.87 2.26 2.5
MHF/MHR/MH (dN-m) 15.80 15.52 14.69 16.59
MH-ML (dN-m) 13.36 13.65 12.43 14.09
FINAL S' (dN-m) 13.91 13.20 13.27 14.48
ts - 2 Mins 4.38 4.18 4.14 3.76
ts - 30 Mins 5.03 5.00 4.79 4.6
ts - 90 Mins 10.92 10.80 11.49 10.65
Stress-strain SC
50% MOD kg/cm2 12.63 12.84 12.07 14.89
100% MOD kg/cm2 20.88 20.57 19.71 25.85
200% MOD kg/cm2 54.51 52.68 49.80 70.15
300% MOD kg/cm2 107.43 106.74 95.46 132.99
400% MOD kg/cm2 168.73 169.75 150.14 200.51
Tensile
strength (kg/cm2) 294.93 298.80 279.58 287.00
Elongation at break % 601.4 601.0 614.2 533.9
M300% / M50% 8.51 8.31 7.91 8.93
Tensile strength (SD) 8.68 10.23 7.42 4.43
Hardness Shore A 66.7 66.4 62.9 66.7
Angle tear strength (kg/cm) 128.87 130.21 127.71 119.78
Carbon black dispersion
X-Value 7.65 4.56 7.85 6.20
Y-Value 9.61 8.51 9.47 9.04
Z-Value 88.22 79.41 90.04 83.88
DMTA – ISO @ 70°
E’ (Mpa) 5.3880 5.7195 5.2765 5.9360

E’’ (Mpa) 0.9001 1.0145 0.9603 1.0220
Tan delta 0.1671 0.1774 0.1819 0.1722
E* (Mpa) 5.4630 5.8085 5.3635 6.0235
DIN Abrasion (DIN 53516)
Abrasion resistance index (%) 124.76 121.45 110.71 124.10
Advantages of the present disclosure
[0063] The above-mentioned implementation examples as described on this
subject matter and its equivalent thereof have many advantages, including those
5 which are described.
[0064] The present disclosure discloses a simple, cost effective, one step process for the preparation of an elastomer composite. The process includes pre-mixing of the particulate and the elastomer in a high-speed mixer which results in complete dispersion of the particulate in the elastomer. The process of the present disclosure
10 provides an enhanced homogenous distribution of the solid particulate ingredients in
the elastomer present in liquid phase and hence eliminates the step of adding carbon black slurry. Mixing solid particulate (carbon black) with the elastomer in latex form is also helpful in keeping the production floor clean and devoid of dust and dirt. The elastomer composite of the present disclosure involves use of premix material which
15 is more uniform in terms ingredient ratio. The process of the present disclosure
enables ease of processing, since one feeder in the extruder is used for loading the material instead of the use of 2 feeders. Use of extruder with one feeder ensures uniform addition of ingredient and thereby yields consistent elastomer composite(masterbatch). The process of the present disclosure avoids the use of two
20 feeders in extruders and thereby eliminates the inconsistencies in the masterbatches
obtained arising due to independent additions of ingredients and/or malfunctioning of the feeders. Thus, the process of the present disclosure is an efficient and effective process for industrial scale preparation of the elastomer composite.

I/We Claim:
1. An improved process for preparing an elastomer composite, the process
comprising:
a. mixing at least one solid particulate with at least one elastomer in
latex form in the presence of at least one surfactant in a mixer to
obtain a first mix; and
b. processing the first mix in an extruder to obtain the elastomer
composite,
wherein processing the first mix is carried out at a temperature in a range of 90 to 150℃.
2. The process as claimed in claim 1, wherein mixing at least one solid particulate with at least one elastomer in latex form in the presence of at least one surfactant in a mixer is carried out at a speed in a range of 200 to 800 rpm.
3. The process as claimed in claim 1, wherein processing the first mix is followed by drying at a temperature in a range of 90 to 150℃.
4. The process as claimed in claim 1, wherein processing the first mix in an extruder is carried out at a speed in a range of 100 to 1000 rpm.
5. The process as claimed in claim 1, wherein the elastomer, the solid particulate and the surfactant are in weight ratio range of 100:50:2 to 100:40:0.1.
6. The process as claimed in claim 1, wherein the at least one solid particulate is selected from carbon black, silica, calcium carbonate, clay, or combinations thereof.
7. The process as claimed in claim 1, wherein the at least one elastomer is selected from natural rubber, styrene butadiene rubber, butadiene rubber, acrylonitrile butadiene rubber, chloroprene rubber, neoprene rubber, or combinations thereof.
8. The process as claimed in claim 1, wherein the surfactant is selected from anionic, cationic, and non-ionic surfactants; and the anionic surfactant is selected from alkoxylated fatty alcohol ether sulphates, fatty acid salts, alkyl sulfates, alkyl benzene sulfonates, alkyl naphthalene sulfonates, alkyl

sulfosuccinates, alkyl diphenyl ether disulfonates, sodium 2-naphthalene sulfonate formaldehyde condensates, polycarboxylate polymer type surfactants, or combinations thereof.
9. The process as claimed in claim 1, wherein the elastomer has a dry rubber content (DRC) in a range of 20-70%.
10. The process as claimed in claim 1, wherein the extruder is a co-rotating twin screw extruder.
11. A formulation comprising:

a) the elastomer composite prepared by the process as claimed in any one of the claims 1-10; and
b) at least one additive selected from fillers, activators, accelerators, antioxidant, antiozonant, peptizer, processing aid, retarder, or combinations thereof.