Description:FIELD OF THE INVENTION
The present disclosure relates to a rubber composition. In particular, the present disclosure relates to a rubber composition that includes an industrial waste.
BACKGROUND
Brine sludge is an industrial waste generated in large amounts by the Chlor-alkali industry which produces chlorine, sodium hydroxide (caustic soda). Typically, in the chloro-alkali industry, the production of sodium hydroxide (NaOH) and chlorine is carried out by the electrolysis of a brine solution. The brine solution that is used in this process is purified such that sulphate and chloride salts are removed from the brine before it can be used. For the removal of sulphate and chloride from the brine solution barium carbonate and sodium carbonate is respectively used. Because of the use of these chemical a brine sludge waste containing mainly barium sulphate, calcium carbonate and magnesium hydroxide is generated. In addition to these chemical the brine sludge also contains sodium chloride and various other materials such as chromium, zinc, copper and vanadium. Thus, a major challenge that is faced by this industry is the disposal of the brine sludge that is discharged. Traditionally, the brine sludge is disposed in landfills that adversely affects the ecosystem. It is, therefore, required to find alternate solutions for brine sludge management.
SUMMARY
A rubber composition is provided. The rubber composition comprises a rubber component; and a filler in a range of 40 to 80 parts by mass per 100 parts by mass of rubber component. The filler comprises brine sludge powder in a range of 20wt% to 100wt%, wherein the brine sludge powder has 2% to 5% moisture and a particle size distribution of D90 in a range of 50 to 500 µm..
A rubber compounding filler is also provided. The filler comprises of brine sludge powder in a range of 20wt% to 100wt%, wherein the brine sludge powder has 2% to 5% moisture and a particle size of D90 in a range of 50 to 500 µm.
A method of preparing the rubber compounding filler is also provided. The method comprises drying brine sludge to reduce the moisture content of the brine sludge to 2wt% to 5wt% weight of the brine sludge ; and milling the dried brine sludge such that the dried brine sludge powder has a particle size distribution of D90 in a range of 50 to 500 µm.
DETAILED DESCRIPTION
To promote an understanding of the principles of the disclosure, reference will now be made to embodiments and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the disclosure is thereby intended, such alterations and further modifications in the disclosed composition and process, and such further applications of the principles of the disclosure therein being contemplated as would normally occur to one skilled in the art to which the disclosure relates.
It will be understood by those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the disclosure and are not intended to be restrictive thereof.
Reference throughout this specification to “one embodiment” “an embodiment” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Thus, appearances of the phrase “in one embodiment”, “in an embodiment” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.
In the broadest scope, the present disclosure relates to a rubber composition that comprises a rubber component and a filler wherein the filler comprises brine sludge powder.
As used herein, the term “weight percent” or “weight %” or “wt%” is meant to refer to the quantity of weight of the constituent/material in the composition or the component as a percentage weight to the total weight of the composition or the component. For example, the term 10wt% would mean that if the total weight of composition is 100g, the wight of the constituent is 10g.
Rubber component
In an aspect, the rubber component includes but is not limited to a styrene butadiene rubber (SBR), a natural rubber, a butadiene rubber, an isoprene rubber, a butyl rubber, a halogenated butyl rubber, an ethylene propylene diene rubber, a butadiene acrylonitrile copolymer rubber and a chloroprene rubber. These rubbers may be used alone or in the form of a mixture of any two or more thereof.
In an aspect, the method of producing the rubber used as the rubber component is not particularly limited, and any suitable commercially available products may be used as the rubber component.
Filler
The rubber composition comprises the filler in a range of 40 to 80 parts by mass on the basis of 100 parts by mass of the rubber component. In an embodiment, the filler in the rubber composition is in a range of 50 to 70 parts by mass on the basis of 100 parts by mass of the rubber component. In an embodiment, the filler is 50 parts by mass on the basis of 100 parts by mass of the rubber component.

The filler comprises 20wt% to 100wt% of brine sludge powder, based on the total weight of the filler. In some embodiments, the filler comprises of 100wt% brine sludge powder. In other embodiments, the filler comprises brine sludge powder along with calcium carbonate. In such embodiments, the brine sludge powder in the range of 20wt% to 90 wt% and calcium carbonate is in the range of 80wt% to 10wt%. In some embodiments, the filler comprises 50 wt% brine sludge powder and 50wt% calcium carbonate.
In accordance with an aspect, the brine sludge powder has between 2% to 5% moisture. In some embodiments, the brine sludge powder has between 2% to 3% moisture. In another aspect the brine sludge powder in the filler has a particle size of D90 in a range of 50 to 500 µm and preferably in a range of 100 to 250 µm. In some embodiments the brine sludge powder in the filler has a particle size distribution of D10 – 0.89 µm, D50 – 3.79 µm, D90 – 11.86 µm and D100 – 24.03 µm. Smaller the particle size along with a narrow particle size distribution allows for better compounding of the rubber composition.
The brine sludge powder comprises:
- Barium Sulphate in a range of 10 to 55wt%,
- Calcium Carbonate in a range of 15 to 40wt%,
- Magnesium Hydroxide in a range of 10 to 30wt%,
- Sodium Chloride in a range of 5 to 20wt%,
- Sodium Carbonate in a range of 0.6 to 0.9wt%,
- Sodium Hydroxide in a range of 0.2 to 0.4wt%,
- Sodium Sulphate in a range of 0.1 to 0.3 wt%; and
- moisture in a range of 2 to 5%.
In some embodiments, the brine sludge powder has a composition, comprising:
- Barium Sulphate in a range of 25 to 55wt%,
- Calcium Carbonate in a range of 10 to 20wt%,
- Magnesium Hydroxide in a range of 7 to 15wt%,
- Sodium Chloride in a range of 10 to 20wt%,
- Sodium Carbonate in a range of 0.6 to 0.9wt%;
- Sodium Hydroxide in a range of 0.2-0.4wt%;
- Sodium Sulphate in a range of 0.1 to 0.3wt%; and
- moisture in a range of 2-3wt%.
Each of the components of the brine sludge powder work in a synergistic manner to enable the brine sludge powder to be used as a filler in rubber.
Carbon Black
In an aspect, the rubber composition comprises carbon black. The carbon black is present in the rubber composition in an amount ranging from 50 to 70 parts by mass on the basis of 100 parts by mass of the rubber component. In an embodiment, 60 parts by mass on the basis of 100 parts by mass of the rubber component of carbon black is present in the rubber composition. The examples of carbon black that may be added include but are not limited to furnace black, channel black, thermal black, acetylene black and Ketjen black. Any known and commercially available carbon black may be added to the rubber composition. The carbon black preferably has an average particle size of from 5 to 100 nm, more preferably from 5 to 80 nm, and still more preferably from 5 to 70 nm form the viewpoint of enhancing a dispersibility, a mechanical strength and a hardness of the resulting rubber composition.
Crosslinking Agents
In an aspect, the rubber composition includes a crosslinking agent. The crosslinking agent may be selected from a group consisting of sulfur, sulfur compounds, peroxides, phenol resin, amino resins, quinone and quinone dioxime derivatives, halogen compounds, aldehyde compounds, alcohol compounds, epoxy compounds, metal halides and organic metal halides, and silane compounds. These crosslinking reagents may be used alone or in combination of any two or more thereof. In an embodiment, the cross-linking agent is a sulphur compound. In an embodiment, the cross-linking agent is sulphur.
The crosslinking agent in the rubber composition is in an amount from 0.1 to 5 parts by mass on the basis of 100 parts by mass of the rubber component. In some embodiments, the crosslinking agent in the rubber composition is in an amount of 1.5 to 2.5 parts by mass on the basis of 100 parts by mass of the rubber component. In an embodiment, the rubber composition comprises sulphur in an amount of 2 parts by mass on the basis of 100 parts by mass of the rubber component.
Vulcanization aid
In accordance with an aspect, a vulcanization aid is added to the rubber composition when sulphur is used as a crosslinking reagent. The vulcanization aid is selected from a group including fatty acids such as stearic acid and metal oxides such as zinc oxide. The vulcanization aid in the rubber composition is in an amount from 0.1 to 10 parts by mass on the basis of 100 parts by mass of the rubber component. In some embodiments, a combination of zinc oxide and stearic acid is used as the vulcanization aid in the rubber composition. In some embodiments, the rubber composition comprises zinc oxide in an amount of 4 to 6 parts by mass on the basis of 100 parts by mass of the rubber component and stearic acid in an amount of 0.5 to 1.5 parts by mass on the basis of 100 parts by mass of the rubber component. In an embodiment, the rubber composition comprises zinc oxide in an amount of 5 parts by mass on the basis of 100 parts by mass of the rubber component and stearic acid in an amount of 1 part by mass on the basis of 100 parts by mass of the rubber component.
Vulcanization accelerator
In addition to the vulcanization aid, a vulcanization accelerator may also be added to the rubber composition, to accelerate the process of vulcanization. Examples of the vulcanization accelerator include guanidine-based compounds, sulfene amide-based compounds, thiazole-based compounds, thiuram-based compounds, thio urea-based compounds, dithiocarbamic acid-based compounds, aldehyde-amine-based compounds or aldehyde-am monia-based compounds, imidazoline-based compounds and Xanthate-based compounds. In some embodiments, the vulcanization accelerator is Zinc Dibutyldithiocarbamate (ZDBC). The vulcanization accelerator is added to the rubber composition in an amount in a range from 0.1 to 5 parts by mass on the basis of 100 parts by mass of the rubber component. In an embodiment, the vulcanization accelerator is added to the rubber composition in an amount of 2 parts by mass on the basis of 100 parts by mass of the rubber component. In an embodiment, the vulcanization accelerator is N-cyclohexyl-2- benzothiazole sulfenamide and is added in an amount of 1.5 parts by mass on the basis of 100 parts by mass of the rubber component.
Super vulcanization accelerator
In accordance with an aspect, the rubber composition may further comprise of a super vulcanization accelerator. Examples include Tetramethylthiuram disulfide, Zinc dibenzyldithiocarbamate (ZBEC). The super vulcanization accelerator may be added to the rubber composition in an amount from 0.5 to 2 parts by mass on the basis of 100 parts by mass of the rubber component. In an embodiment, the rubber composition comprises Tetramethylthiuram disulfide in an amount of 2 parts by mass on the basis of 100 parts by mass of the rubber component. In an embodiment, the rubber composition comprises tetramethylthiuram disulfide in an amount of 1.5 parts by mass on the basis of 100 parts by mass of the rubber component.
Curing accelerator
In accordance with an aspect, the rubber composition may further comprise of a curing accelerator. Examples of curing accelerators include 2-Mercaptobenzothiazole (MBT), zinc 2-Mercaptobenzothiazole and tetramethylthiuram disulfide. The curing accelerator may be added to the rubber composition in an amount ranging from 1 to 2 parts by mass on the basis of 100 parts by mass of the rubber component. In an embodiment, the rubber composition comprises 2-Mercaptobenzothiazole in an amount of 1.5 parts by mass on the basis of 100 parts by mass of the rubber component.
Softening reagent
In some embodiments, the rubber composition may also contain, if required, a softening reagent for the purpose of improving a processability, flowability or the like of the resulting rubber composition. Examples of the softening reagent include a process oil such as a silicone oil, an aroma oil, TDAE (treated distilled aromatic extracts). MES (mild extracted Solvates), RAE (residual aromatic extracts), a paraffinic oil and a naphthene oil; and a liquid polymer such as a low-molecular weight polybutadiene, a low-molecular weight polyisoprene, a low-molecular weight styrene-butadiene copolymer and a low-molecular weight styrene-isoprene copolymer. The process oil or liquid polymer as the softening reagent is added in the rubber composition in an amount of less than 50 parts by mass on the basis of 100 parts by mass of the rubber component. In an embodiment, the rubber composition comprises paraffinic oil in a range of 18 to 22 parts by mass on the basis of 100 parts by mass of the rubber component. In an embodiment, the rubber composition comprises paraffinic oil in an amount of 20 parts by mass on the basis of 100 parts by mass of the rubber component.

Silica
The rubber composition may optionally include silica. In some embodiments, the rubber composition comprises silica in an amount ranging from 40 to 70 parts by mass on the basis of 100 parts by mass of the rubber component. Any known commercially available silica may be added to the rubber composition.
Additives
For the purposes of enhancing a mechanical strength of the rubber composition, improving various properties such as a heat resistance and a weathering resistance thereof, controlling a hardness, thereof, additives may be added to the rubber composition. These additives are selected from the group consisting of an antioxidant, an oxidation inhibitor, a lubricant, a light stabilizer, a scorch retarder, a processing aid, a colorant, a flame retardant, an antistatic reagent, a delustering reagent, an anti-blocking reagent, an ultraviolet absorber, a release reagent, a foaming reagent, an antimicrobial reagent, a mildew-proofing reagent and a perfume. These additives are added for improving a weathering resistance, a heat resistance, an oxidation resistance or the like of the resulting rubber composition. In an embodiment, the rubber composition comprises 6PPD as an antioxidant in an amount of 1.5 by mass on the basis of 100 parts by mass of the rubber component.
Additional fillers
The rubber composition may also contain other or additional fillers, if required. These additional fillers may be selected based on the application for which the rubber composition is finally being used. These additional fillers are selected from a group consisting of organic fillers, and inorganic fillers such as clay, talc, mica, glass fibers, fibrous fillers and glass balloons. These additional fillers may be added alone or as mixtures. These additional fillers may be added in an amount from 40 to 70 parts by mass on the basis of 100 parts by mass of the rubber component. When the amount of the filler compounded falls within the above-specified range, the resulting rubber composition can be furthermore improved in mechanical strength.
Any method for producing the rubber composition may be used.
Method of preparing a filler
The disclosure also provides a method of preparing a filler for a rubber composition. The method comprises of drying brine sludge to reduce the moisture content of the brine sludge to 2wt% to 5wt% of the total brine sludge to obtain dried brine sludge. The dried brine sludge is then milled to obtain a brine sludge powder having a particle size distribution of D90 in the range of 50 to 500 µm, preferably in a range of 100 to 250 µm. In an embodiment, the dried brine sludge is then milled to obtain a brine sludge powder having a particle size distribution of D10 – 0.89 µm, D50 – 3.79 µm, D90 – 11.86 µm and D100 – 24.03 µm.
In some embodiments, the brine sludge is dried at 150oC for 2 to 10 hours till the water content of the brine sludge is reduced to 2wt% to 5wt% of the total brine sludge to obtain a dried brine sludge .
In some embodiments, the brine sludge powder obtained is used as such in the rubber composition as a filler. In other words, the filler comprises of 100wt% of the brine sludge powder. In some other embodiments, the brine sludge powder obtained is mixed with calcium carbonate. In some embodiments, the filler may be such that it comprises brine sludge powder in the range of 20wt% to 90 wt% and calcium carbonate in the range of 80wt% to 10wt%.
Examples
The compositions of the following examples were prepared using the components disclosed in Table 1 below. The compositions so obtained were then tested for various properties. The Table 2 below provides the properties of the compositions prepared.
Table 1 - Rubber Compounding Formulations of Example 1
Ingredients UOM Comparative Example
CaCO3 Example 1A
Treated BSP* Example 1B
Untreated BSP
EPDM (Keltan 4450S) PHR# 100 100 100
Carbon Black (N550) 65 65 65
CaCO3 60 -- --
Brine Sludge Powder (BSP) -- 60 60
Paraffinic Oil 20 20 20
ZnO 5 5 5
Stearic Acid 1 1 1
Sulphur 1 1 1
Zinc Dibutyldithiocarbamate (ZDBC) 2 2 2
Tetramethylthiuram disulfide (TMTD) 0.5 0.5 0.5
2-Mercaptobenzothiazole (MBTS) 1.5 1.5 1.5
* - The Brine Sludge Powder was treated with 1% stearic acid
# parts by mass per 100 parts by mass of the rubber component
Table 2 - Summary of all results
Test Unit CaCO3 Treated BSP Untreated BSP
Ts2 (Scorch Safety) Minute 1.4 1.2 1.2
Tc90 @ 160°C Minute 12.6 17.3 25.8
MH-ML (Cross-link density) Lbin 22.2 21.5 19.9
Hardness (B.A) Shore A 76 77 74
100% Modulus(B.A) MPa 3.1 3.4 3
200% Modulus (B.A) MPa 6.6 6.9 6.8
300% Modulus (B.A) MPa 9.6 - -
Tensile Strength (B.A) MPa 10.7 7.5 7.8
Elongation @ Break(B.A) % 350 230 220
100% Modulus (A.A 100°C/24hr) MPa 3.3 3.3 3.2
200% Modulus (A.A 100°C/24hr) MPa 7.4 6.8 7.1
300% Modulus (A.A 100°C/24hr) MPa 9.5 - -
Change in Hardness Point +1 0 +1
Change in Tensile Strength
(A.A 100°C/24hr ) % -7 0 +9

Change in E.B (A.A 100°C/24hr ) % -11 -4 +9

Compression Set
(100°C/25% defl./ 24hr) % 22 27 22

Flame Test - Burn continuously
on removal of flame Burn continuously
on removal of flame Burn continuously
on removal of flame

Abrasion Resistance Index (ARI) - 52 57 64
Residual Volume Loss (RVL) mm3 262 240 213
Tear Strength N/mm 33 32 33
Demattia Flexing
(Bend flexing, Cut initiation) Cycles (For cut initiation) 3250 200 200

B.A – Before Aging and A.A – After Aging
Example 1 – Discussion of Results
By replacing CaCO3 with the Brine Sludge Powder
1. Scorch safety (Ts2) is reducing slightly while time taken to achieve 90% cure (Tc90) has increased significantly for both treated and untreated BSP. The above can be adjusted by tweaking the curing package.
2. The cross link density is also reducing slightly which shall get reflected in the mechanical properties
3. Before Aging - The tensile strength and elongation are reducing while hardness is maintained
4. Post Aging – The CaCO3 sample is showing reduction in strength and elongation while it is increasing for the untreated brine sludge sample. The hardness is maintained post aging as well
5. Before Aging - The moduli at 100% & 200% strains respectively is maintained. However, the sample is becoming brittle/rigid enough to not stretch beyond 300% strain
6. Post Aging – Similar trend
7. The abrasion resistance index is improving while the relative volume loss is reducing significantly (lower is better)
8. Compression set (a measure of resilience in sample) is maintained. Lower is better.
9. Flame property and tear strength are maintained as well.
10. Cut initiation on the other hand is happening much earlier.
11. Overall, treatment of the brine sludge powder is not making any improvements, rather the untreated powder is performing better at most instances.

Example 2 – Rubber Compounding Formulation
The compositions were prepared using the components disclosed in Table 3 below. The compositions so obtained were then tested for various properties. The Table 4 below provides the properties of the compositions prepared.

Table 3: Rubber Compounding Formulations of Example 2
Ingredients UOM Comparative Example
CaCO3 Example 2A
50:50 Example 2B
100% BSP
Natural Rubber PHR* 100 100 100
Carbon Black (N774) 50 50 50
CaCO3 50 25 --
Brine Sludge Powder (BSP) -- 25 50
Clay 70 70 70
Aromatic Oil 12 12 12
Sulphur 2 2 2
ZnO 5 5 5
Stearic Acid 1.5 1.5 1.5
N-cyclohexyl-2- benzothiazole sulfenamide (CBS) 1.5 1.5 1.5
Tetramethylthiuram disulfide (TMTD) 0.25 0.25 0.25
6PPD 1.5 1.5 1.5
* parts by mass per 100 parts by mass of the rubber component
Table 3 - Summary of all results
Test Unit Comparative Example
CaCO3 Inventive Example 2A
50:50 Inventive Example 2B
100% BSP
Ts2 (Scorch Safety) Minute 1.7 1.3 1.1
Tc90 @ 150°C Minute 3.3 2.7 2.4
MH-ML (Cross-link density) Lbin 21.9 23.9 23.5
Hardness (B.A) Shore A 76 78 80
100% Modulus (B.A) MPa 4.4 4.3 5.0
200% Modulus (B.A) MPa 7.4 7.5 8.5
300% Modulus (B.A) MPa 10.4 * *
Tensile Strength (B.A) MPa 10.9 8.5 9.2
Elongation @ Break (B.A) % 311 239 227
100% Modulus (A.A 70°C/24hr) MPa 4.8 4.4 4.9
200% Modulus (A.A 70°C/24hr) MPa 7.8 7.5 8.3
300% Modulus (A.A 70°C/24hr) MPa 10.9 * *
Change in Hardness (A.A 70°C/24hr) Point +2 +3 +1
Change in Tensile Strength
(A.A 70°C/24hr) % +3 +1 +2
Change in E.B (A.A 70 oC/24hr) % -24 -2 +2
Tear Strength N/mm 34 35 35
Flame Test - Burn continuously on removal of flame Burn continuously on removal of flame Burn continuously on removal of flame

Compression Set
(70°C/25% defl./ 24 hr) % 36 48 35

Surface Resistivity ? 9.8 X 107 15.0 X 107 12.9 X 107
Volume Resistivity ?/cm 6.3 X 107 10.5 X 107 7.9 X 107
Taber Abrasion- Mass loss
(H-18/1000 revolutions/ 500gm load) mg/revolution 0.22 0.27 0.22

Demattia Flexing
(Bend flexing, Cut initiation) cycles
(For cut initiation) 1000 300 100

Example 2– Discussion of Results
By replacing CaCO3 with the Brine Sludge Powder
1. Scorch safety (Ts2) is reducing and so is the Tc90. Tc90 going down is favorable in terms of better productivity.
2. The cross link density is improving slightly which shall get reflected in the mechanical properties both prior to and after thermal aging
3. Before Aging – The tensile strength is dropping by about 18% at 100% replacement. Hardness is increasing and tear strength is maintained. With inclusion of BSP in the matrix the rubber samples are becoming more rigid and harder. This is resulting in drop in elongation.
4. Post Aging – There is increase in tensile strengths for all the samples. However, interestingly the pure CaCO3 sample is showing big drop in elongation while the 100% BSP samples show an increase. The hardness is further increasing post aging for all samples.
5. Before Aging – With inclusion of BSP in the matrix the rubber samples are becoming more rigid and harder resulting in higher modulus at low and medium strains. However, BSP samples are not elongating to similar extent as the pure CaCO3 sample
6. Post Aging – The trend is maintained post aging
7. The taber abrasion (Mass Loss) should be lower. With BSP replacement it is getting maintained at 100% replacement
8. Compression set (a measure of resilience in sample is lower better) is also getting maintained at 100% replacement
9. Electrical properties are maintained as well
10. Cut initiation is again happening at a much faster rate compared to the pure CaCO3 sample
11. 100% replacement of CaCO3 with BSP is more favorable than 50%

Specific embodiments are disclosed herein below:

A rubber composition comprising: a rubber component; and a filler in a range of 40 to 80 parts by mass per 100 parts by mass of rubber component wherein the filler comprises brine sludge powder in a range of 20wt% to 100wt%, wherein the brine sludge powder has 2% to 5% moisture and a particle size distribution of D90 in a range of 50 to 500 µm. .

Such rubber composition(s), wherein the brine sludge powder comprises:
- Barium Sulphate in a range of 10 to 55wt%,
- Calcium Carbonate in a range of 15 to 40wt%,
- Magnesium Hydroxide in a range of 10 to 30wt%,
- Sodium Chloride in a range of 5 to 20wt%,
- Sodium Carbonate in a range of 0.6 to 0.9wt%,
- Sodium Hydroxide in a range of 0.2 to 0.4wt%,
- Sodium Sulphate in a range of 0.1 to 0.3wt%, and
- moisture in a range of 2 to 5wt%.
Such rubber composition(s), wherein the filler comprises brine sludge powder in the range of 20wt% to 90 wt% and calcium carbonate in the range of 80 wt% to 10 wt%.

Such rubber composition(s), wherein the rubber composition comprises carbon black in a range of 50 to 70 parts by mass per 100 parts by mass of rubber component.

Such rubber composition(s), wherein the rubber composition comprises:
- a cross-linking agent in a range of 0.1 to 5 parts by mass per 100 parts by mass of the rubber component;
- a vulcanization aid in a range of 0.1 to 10 parts by mass per 100 parts by mass of the rubber component;
- a vulcanization accelerator in a range of 0.1 to 5 parts by mass per 100 parts by mass of the rubber component;
- a super vulcanization accelerator in a range of 0.5 to 2 by mass per 100 parts by mass of the rubber component;
- a curing accelerator in a range of 1 to 2 by mass per 100 parts by mass of the rubber component; and
- a softening reagent in a range of 18 to 22 parts by mass per 100 parts by mass of the rubber component.

Such rubber composition(s), wherein
- the vulcanization aid is sulphur in a range of 0.5 to 1.5 parts by mass per 100 parts by mass of the rubber component;
- the vulcanization aid is zinc oxide in a range of 4 to 6 parts by mass per 100 parts by mass of the rubber component and stearic acid in a range of 0.5 to 1.5 parts by mass per 100 parts by mass of the rubber component;
- the vulcanization accelerator is Zinc Dibutyldithiocarbamate in range of 1.5 to 2.5 parts by mass per 100 parts by mass of the rubber component;
- the super vulcanization accelerator is Tetramethylthiuram disulfide in a range of 0.5 to 1 parts by mass per 100 parts by mass of the rubber component;
- the curing accelerator is 2-Mercaptobenzothiazole in a range of 1 to 2 parts by mass per 100 parts by mass of the rubber component; and
- the softening reagent is paraffinic oil in a range of 18 to 22 parts by mass per 100 parts by mass of the rubber component.
Such rubber composition(s), wherein the composition further comprises additional fillers selected from a group comprising china clay and silica in a range of 40 to 70 parts by mass per 100 parts by mass of the rubber component.

A rubber compounding filler comprising brine sludge powder brine sludge powder in a range of 20wt% to 100wt%, wherein the brine sludge powder has 2% to 5% moisture and a particle size distribution of D90 in a range of 50 to 500 µm. .

Further, specific embodiments are provided herein below:

A method of preparing the rubber compounding filler, the method comprising drying brine sludge to reduce the moisture content of the brine sludge to 2wt% to 5wt% weight of the brine sludge ; and milling the dried brine sludge such that the dried brine sludge powder has a particle size distribution of D90 in a range of 50 to 500 µm. .
Such method(s), wherein the brine sludge is dried at 150oC for 5 to 10 hours.
INDUSTRIAL APPLICABILITY
The present disclosure provides a filler for a rubber composition that is obtained from an industrial waste. This filler allows for the use of brine sludge powder which is a major waste product produced by the Chloralkaline industry, for a producing a useful product. Moreover, since an industrial waste product is used, the overall cost of the rubber composition is reduced. Moreover, the filler used results in a rubber composition having almost the same properties as those obtained using traditional fillers. It is possible that addition of that the filler that includes the brine sludge powder may enhance flame properties and limited oxygen index (LOI). It is the various components that are present in the brine sludge that work in a synergistic manner to achieve these properties. The rubber composition as disclose thus find use in variety of applications such as hoses, mudflaps, Floormat, O-rings, Gaskets and bushes etc.

Additionally, the method of preparing the filler is simple and does not require any complex chemical reactions etc, without using any specialized and expensive equipment. This further, keeps the cost of production of the rubber composition down. , Claims:1. A rubber composition comprising:
a rubber component; and
a filler in a range of 40 to 80 parts by mass per 100 parts by mass of rubber component wherein the filler comprises brine sludge powder in a range of 20wt% to 100wt%, wherein the brine sludge powder has 2% to 5% moisture and a particle size distribution of D90 in a range of 50 to 500 µm. .
2. The rubber composition as claimed in claim 1, wherein the brine sludge powder comprises:
- Barium Sulphate in a range of 10 – 55wt%,
- Calcium Carbonate in a range of 15 to 40wt%,
- Magnesium Hydroxide in a range of 10 to 30wt%,
- Sodium Chloride in a range of 5 to 20wt%,
- Sodium Carbonate in a range of 0.6 to 0.9wt%,
- Sodium Hydroxide in a range of 0.2 to 0.4wt%,
- Sodium Sulphate in a range of 0.1 to 0.3wt%, and
- moisture in a range of 2 to 5wt%.
3. The rubber composition as claimed in claim 1, wherein the filler comprises brine sludge powder in the range of 20wt% to 90 wt% and calcium carbonate in the range of 80 wt% to 10 wt%.
4. The rubber composition as claimed in claim 1, wherein the rubber composition comprises carbon black in a range of 50 to 70 parts by mass per 100 parts by mass of rubber component.
5. The rubber composition as claimed in claim 1, wherein the rubber composition comprises:
- a cross-linking agent in a range of 0.1 to 5 parts by mass per 100 parts by mass of the rubber component;
- a vulcanization aid in a range of 0.1 to 10 parts by mass per 100 parts by mass of the rubber component;
- a vulcanization accelerator in a range of 0.1 to 5 parts by mass per 100 parts by mass of the rubber component;
- a super vulcanization accelerator in a range of 0.5 to 2 by mass per 100 parts by mass of the rubber component;
- a curing accelerator in a range of 1 to 2 by mass per 100 parts by mass of the rubber component; and
- a softening reagent in a range of 18 to 22 parts by mass per 100 parts by mass of the rubber component.
6. The rubber composition as claimed in claim 6, wherein
- the vulcanization aid is sulphur in a range of 0.5 to 1.5 parts by mass per 100 parts by mass of the rubber component;
- the vulcanization aid is zinc oxide in a range of 4 to 6 parts by mass per 100 parts by mass of the rubber component and stearic acid in a range of 0.5 to 1.5 parts by mass per 100 parts by mass of the rubber component;
- the vulcanization accelerator is Zinc Dibutyldithiocarbamate in range of 1.5 to 2.5 parts by mass per 100 parts by mass of the rubber component;
- the super vulcanization accelerator is Tetramethylthiuram disulfide in a range of 0.5 to 1 parts by mass per 100 parts by mass of the rubber component;
- the curing accelerator is 2-Mercaptobenzothiazole in a range of 1 to 2 parts by mass per 100 parts by mass of the rubber component; and
- the softening reagent is paraffinic oil in a range of 18 to 22 parts by mass per 100 parts by mass of the rubber component.
7. The rubber composition as claimed in claim 1, wherein the composition further comprises additional fillers selected from a group comprising china clay and silica in a range of 40 to 70 parts by mass per 100 parts by mass of the rubber component.
8. A rubber compounding filler comprising brine sludge powder brine sludge powder in a range of 20wt% to 100wt%, wherein the brine sludge powder has 2% to 5% moisture and a particle size distribution of D90 in a range of 50 to 500 µm. .
9. A method of preparing the rubber compounding filler, the method comprising drying brine sludge to reduce the moisture content of the brine sludge to 2wt% to 5wt% weight of the brine sludge; and milling the dried brine sludge such that the dried brine sludge powder has a particle size distribution of D90 in a range of 50 to 500 µm. .
10. The method of preparing the rubber compounding filler as claimed in claim 10, wherein the brine sludge powder is dried at 150oC for 5 to 10 hours.