Description:FIELD OF THE INVENTION
The present disclosure relates to a polyvinyl chloride (PVC) composition. In particular, the present disclosure relates to a PVC composition that includes an industrial waste.
BACKGROUND
Polyvinyl chloride (PVC) is widely used in a variety of applications including wire and cable coating, other electrical applications such as plugs, film, foil and sheeting, flooring, wall covering, roofing and membranes. Other uses include films such as stationary films, adhesives tapes and agricultural films. Polyvinyl chloride is also used in footwear, pipe and guttering and fabric coating. The PVC that is used for these purposes, consists of a combination of polyvinyl chloride resin along with other additives such as fillers. Fillers may be broadly defined as solid particulate or fibrous materials are usually incorporated into the polyvinyl chloride resin. These are primarily added to reduce formulation costs. However, fillers are also known to affect the properties of the formulations. Various fillers are known including calcium carbonate, talc, fibres etc. Since, fillers are added to primary decrease the costs of the formulation, the costs of these fillers can have a significant impact of the final cost of the formulation on a commercial scale.

Brine sludge is an industrial waste generated in large amounts by the Chlor-alkali industry which produces chlorine and 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 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 polyvinyl chloride (PVC) composition is provided. The composition comprises a polyvinyl chloride resin in a range of 40 wt % to 70 wt %, a plasticizer in a range of 10wt% to 40wt%, a stabilizer in a range of 0.01wt% to 0.5wt%; and a filler in a range of 15wt% to 50wt%. The filler comprises 20wt% to 100wt% brine sludge powder based on the total weight of the filler. The brine sludge powder has 2wt% to 5wt% moisture and a particle size of D90 in a range of 50 to 500 µm.

A filler for a polyvinyl chloride composition is also provided. The filler comprises 20wt% to 100wt% of brine sludge powder. The brine sludge powder has 2% to 5% moisture and particle size distribution of D90 in a range of 50 to 500 µm.

A method of preparing a filler for a polyvinyl chloride composition is also provided. The method comprises drying brine sludge to reduce the moisture content of the brine sludge to 2wt% to 5wt% to obtain dried brine sludge; and milling the dried brine sludge to obtain brine sludge powder with 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.

All the components in the following disclosure are provided by way of “weight percent” abbreviated to “wt%”. 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.

In the broadest scope, the present disclosure relates to a polyvinyl chloride (PVC) composition that comprises a polyvinyl chloride resin and a filler wherein at least 50wt% of the filler is brine sludge powder.

In some embodiments, the PVC composition comprises a polyvinyl chloride resin; a plasticizer; a stabilizer; and a filler, wherein the filler comprises at least 20wt% brine sludge powder based on the total weight of the filler.

As used herein, the term “polyvinyl chloride resin or PVC resin' means homopolymers of polyvinyl chloride resin(s), copolymers of polyvinyl chloride resin(s), and mixtures thereof. Copolymers of vinyl chloride are formed by the copolymerization of vinyl chloride and other monomers or monomer blends. Suitable monomers include vinyl acetate, ethylene, propylene, maleate, methacrylate, acrylate, high alcohol vinyl ester, urethane, chlorinated urethane, methylmethacrylate, and mixtures thereof. Examples of monomer blends include ethylene-vinyl acetate copolymer, acrylonitrile-butadiene-styrene terpolymer, acrylonitrile-butadiene copolymer, and mixtures thereof. The monomers or monomer blends may be present in an amount of up to 10 parts per hundred parts resin (the term “parts per hundred parts resin' is used herein to define the quantity of the components based on the weight of the resin and is abbreviated “PHR).
In an aspect, the polyvinyl resin of the PVC composition has a degree of polymerization (DP) which is between 650 and 1600, preferably between 900 and 1100, and an inherent viscosity (IV) between 0.5 and 1.4 (based on ASTMD-1243). The polyvinyl resin may be formulated from a single PVC resin or a mixture of two or more different PVC resins. When two or more different PVC resins are used, the PVC resins preferably have degrees of polymerization which are relatively close in value. The polyvinyl chloride resin in the PVC composition is in a range of 30wt% to 80wt%. In some embodiment, the polyvinyl chloride in the PVC composition is in a range of 40wt% to 70wt%. In an embodiment, the PVC composition comprises 50wt% of the polyvinyl chloride resin.

The PVC composition comprises the filler in a range of 15wt% to 50wt%. In some embodiments, the PVC composition comprises the filler in a range of 25wt% to 45wt%. In an embodiment, the filler in the PVC composition is 20 wt%. The amount of filler that may be added to the PVC composition depends on the application of the PVC composition.

The filler comprises of the total weight of the filler, 20wt% to 100wt% of brine sludge powder. In some embodiments, the filler comprises brine sludge powder along with calcium carbonate. In such embodiments, the filler includes the brine sludge powder in the range of 20wt% to 90 wt% and calcium carbonate in a range of 80wt% to 10wt% of the total weight of the filler. In an embodiment, the filler comprises 50wt% brine sludge powder and 50wt% calcium carbonate of the total weigh of the filler.
In accordance with an aspect, the brine sludge powder has between 2wt% to 5wt% moisture. In some embodiments, the brine sludge powder has between 2wt% to 3wt% 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 the reinforcement of the PVC 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 30%,
- 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%.
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 to15wt%,
- 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 to 0.4wt%;
- Sodium Sulphate in a range of 0.1 to 0.3wt%; and
- moisture in a range of 2 to 3wt%.
The various components that are present in the brine sludge work in a synergistic manner to allow them to be used as a part of the filler in the PVC composition. The PVC compositions that are obtained with brine sludge powder as a part of the filler, have the same properties as those obtained using traditional fillers. Additionally, the addition of that the filler that includes the brine sludge powder may also enhance the flame properties along with thermal stability of base PVC resin.

In an aspect, the plasticizer in the PVC composition is in a range of 10wt% to 40wt%. In some embodiments the plasticizer is in a range from 15wt% to 25wt%. In an embodiment, the PVC composition includes 15wt%. of the plasticizer. Any known plasticizer may be utilized in the PVC composition. The plasticizer includes but is not limited to dioctyl phthalate, di-2-ethyl hexyl phthalate, diisooctyl phthalate, diisononyl phthalate, di-linear nonyl phthalate, di linear nonyl, undecyl phthalate, di-linear undecyl phthalate, diundecyl phthalate, diisodecylpthalate, Co-Co straight chain phthalates, C, linear phthalate, Colinear phthalate, C linear phthalate, ditridecyl phthalate, undecyl dodecyl phtha late, di(2-propylheptyl phthalate), nonylundecyl phthalate, texanolbenzylphthalate, polyester phthalate, diallylphtha late, n-butylphthalyl-n-butyl glycosate, dicaprylphthalate, butylcyclohexyl phthalate, dicyclohexyl phthalate, butyl octyl phthalate, dioctylterephthalate, di-2-ethylhexyltereph thalate, dioctyl adipate, di-2-ethyl hexyl adipate, diisonyl adipate, diisooctyladipate, diisodecyl adipate, ditridecyladi pate, dibutoxyethyl adipate, dibutoxyethoxy adipate, di(noc tyl, indecyl)adipate, polyester adipate, poly glycol adipates, trioctyl trimellitate, tri-2-ethylhexyl trimellitate, triisooctyl trimellitate, tri isononyl trimellitate, triisodecyl trimellitate, tri-n-hexyl trimelitate, dioctyl azelate, di-2-ethylhexyl glut arate, di-2-ethylhexyl sebecate, dibutyl sebecate, dibutoxy ethyl sebecate, triethyl citrate, acetyl triethyl citrate, tri-nbutyl citrate, acetylri-n-butyl citrate, acetyltri-n-hexylcitrate, n-butyl tri-n-hexyl citrate, isononyl benzoate, isodecyl ben Zoate, 1.4 cyclohexane dimethanol dibenzoate, 2.2.4 trim ethyl-1.3 pentane diol dibenzoate, 2.2.-dimethyl-1,3 pro panediol dibenzoate, Co-C alkane phenol esters or alkyl Sulphonic phenol ester, acetic acid reaction products with fully hardened castor oil, pentaerythritol tetrabenzoate, glyc erol tribenzoate, polypropylene glycol dibenzoate, tri arylphosphates, diisononyl cyclohexane 1.2 dicarboxylate, polymers of adipic acid/phthalates/adipates/Sebecates/ with glycols and often acid terminated, butylbenzyl phthalate, alkylbenzyl phthalate, C7-Cobutyl phthalate, diethylene glycol dibenzoate, dipropylene glycol dibenzoate, 2-ethylhexyl benzoate, texanolbenzoate, ethylene glycol dibenzoate, pro pylene glycol dibenzoate, triethylene glycol dibenzoate, di heptyl phthalate, dihexyl phthalate, dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, and mixtures thereof. In some embodiments, the plasticizer is selected from a group consisting of Diisononyl phthalate (DINP), Diisodecyl phthalate (DIDP), di(2- ethylhexyl) phthalate (DEHP) and a combination thereof.

In an aspect, the stabilizer in the PVC composition is in a range of 0.01 to 0.5%, preferably 0.05 to 0.1%. In an embodiment, the PVC composition includes 0.03% of stabilizer. The PVC composition may contain a single stabilizer or a mixture of stabilizers. The stabilizer includes metal soaps, organic phosphites, epoxy compounds, tin stabilizers, and mixtures thereof. The stabilizers provide protection against deficient PVC homopolymerization and copolymerization, and functions to eliminate or retard the process of polymer degradation. Metal Soap stabilizers include Zinc Stearate, barium Stearate, calcium stearate, cadmium stearate, barium ricinolate, calcium oleate, calcium laurelate, Zinc octoate, and mixtures thereof. Preferably, the metal soap stabilizers are mixtures of barium Stearate, Zinc Stearate and cadmium Stearate. Epoxy compound stabilizers include epoxy Soybean oil, e.g., Srapex 6.8, ESO, epoxy linseed oil, epoxy polybutadiene, epoxy methylstearate, epoxy Stearate, epoxy ethylhexyl Stearate, epoxy Stearyl Stearate, epoxy propyl isocyanalate 3-(2-case INO)-1,2-epoxy propane, bis-phenol A diglycidyl ether, vinyl dicyclohexanediepoxide, 2.2-bis-(4-hydroxyphenol) propane and epichlorohydrine condensation copolymeration, and mixtures thereof. Organic phosphite stabilizers include diphenyldecyl phosphite, triphenyl phosphite, tris-nonylphenyl phosphite, tri-steareal phosphite, octyldiphenylphosphite, and mixtures thereof. Tin stabilizers include tin dilaurate, dibutyl tin maleate, organic tin mercaptide and organic tin Sulfonic amide, and mixtures thereof.
In some embodiments, the heat stabilizer is selected from a group consisting of lead-based stabilizers such as tribasic lead sulfate, dibasic lead phosphite, dibasic lead stearate, dibasic lead phthalate or basic lead sulfite, calcium zinc stabilizers, barium zinc stabilizer, Barium cadmium stabilizer, Ba-Cd-Zn stabilizer, and Cd-Zn stabilizer.

The PVC compositions may additionally include other additives to impart desired properties to the PVC composition. Various additives may be added depending upon the end use of the PVC composition. Such additives are generally known in the art and may be present in the compositions in an amount sufficient to impart the desired property. The amount of these additives is generally known. Such other additives include but are not limited to anti-static agents, anti-fogging agents, ultra-violet inhibitors, anti-oxidants, light stabilizers, fire retardants, pigments, whiteners and mixtures thereof.

The disclosure also provides a method of preparing a free-flowing powder of PVC composition. To prepare the PVC composition, solid ingredients are first combined and mixed thoroughly. To said mixture, liquid ingredients are slowly added. The mixture is blended until a temperature below the fusion temperature of the PVC is reached. In some embodiments, the mixture is blended till a temperature of about 88°C. is reached. This procedure produced a free-flowing powder of PVC composition in which polyvinyl chloride resin particles are free flowing having the other ingredients absorbed therein.

Alternatively, pellets of PVC composition may also be prepared. To prepare the PVC composition, solid ingredients are first combined and mixed thoroughly. To said mixture, liquid ingredients are slowly added. In an embodiment, pellets of PVC composition are prepared in a PVC pelletizing extrusion line. The PVC pelletizing extrusion lines use a die and cutting system to transform molten PVC compound into uniform-sized pellets. The die shapes the molten PVC into the desired pellet size and shape. The cutting system then cuts the material into pellets as it emerges from the die.

The disclosure also provides a method of preparing a filler for a PVC 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 6 hours till the water content of the brine sludge is reduced to 2wt% to 5wt% of the total brine sludge powder to obtain a dried brine sludge powder.

In some embodiments, the brine sludge powder obtained is used as such in the PVC 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 by mixing the liquid ingredients together using a high intensity mixer and mixed sufficiently to produce a substantially homogeneous mixture. The PVC resin and other solid ingredients are added over a short time period with mixing. The resultant dispersion often is deaerated under vacuum or other conditions. The following properties of were measured:
Table 1: Test method used for measuring various properties of the PVC composition.
Property Test Method
Yield Strength ASTM D 638
Tensile Strength ASTM D 638
Tensile Modulus ASTM D 638
Elongation at Break ASTM D 638
Flexural Strength ASTM D 790
Flexural Modulus ASTM D 790
Izod Impact Strength ASTM D 256
Hardness ASTM D 2240
Density ASTM D 792
Static Coefficient of friction ASTM D 1894
Kinetic Coefficient of friction ASTM D 1894
Abrasion Loss ASTM D 4060
UL-94 Vertical Burning Test Rating ASTM D 3801
UL-94 Horizontal Burning Test (Burning Rate) ASTM D 635
Glass Transition Temperature ASTM D 3418-08
Final Degradation Temperature ASTM E 1131

Example 1
A PVC formulation without the filler was first prepared by mixing the components mentioned in Table 2. From this formulation, PVC composition was prepared by adding various fillers. Table 3 below provides the details of the fillers that are added for preparing the PVC composition. Various properties of the PVC composition were measured. The results obtained are tabulated in Table 4.

Table 2: PVC Formulation (without filler)
Ingredient UOM Amount
PVC Resin (K-67) g 1000
Heat Stabilizer (Ca & Zn Stearate) 30
Stearic Acid 10
Plasticizer (DOP) 200

Table 3: PVC Composition with various fillers
Ingredient UOM Control BSP – 20% BSP – 40%
PVC Compound (as prepared above) % wt. 100 100 100
Brine Sludge Powder (BSP) 0 20 40
Table 4 - Summary of all results
Property UOM Control BSP – 20% BSP – 40%
Yield Strength MPa 28 30 31
Tensile Strength MPa 26 26 23
Tensile Modulus MPa 995 1493 1457
Elongation at Break % 146 8 7
Flexural Strength MPa 26 46 43
Flexural Modulus MPa 867 1980 2299
Izod Impact Strength J/m 51 40 43
Hardness Shore D 65 72 74
Density g/cc 1.32 1.41 1.52
Static Coefficient of friction -- 0.30 0.26 0.30
Kinetic Coefficient of friction -- 0.23 0.21 0.21
Abrasion Loss % 0.04 0.07 0.11
UL-94 Vertical Burning Test Rating -- V0 V0 V0
UL-94 Horizontal Burning Test (Burning Rate) mm/min No Burning No Burning No Burning
Glass Transition Temperature oC 56 53 51
Final Degradation Temperature oC 503 561 565

Discussion of Results
With the addition of Brine Sludge Powder (BSP) to PVC the following with respect to the properties was observed:
1. Yield strength is improving slightly while ultimate tensile strength is initially maintained @ 20% loading and only decreases slightly later @ 40% loading.
2. Tensile modulus is increased by almost 50% with the incorporation of BSP in PVC.
3. Since with the addition of BSP the PVC is becoming more rigid/tougher, the elongation is reducing drastically.
4. Flexural strength is improving by about 70% with the addition of BSP to PVC while the modulus is improving by 130% & 160% respectively @ 20% & 40% loadings.
5. The energy to break and hence the Izod impact strength is reducing only slightly.
6. The hardness is increasing and with incorporation of BSP (which is ~ 50% BaSO4 having density of ~ 4.4 g/cc) the density of the composites is also increasing.
7. The abrasion loss is only increasing slightly while the coefficient of friction (both static & kinetic) is reducing with incorporation of BSP in PVC.
8. Both vertical & horizontal burning tests are maintained. There is no deterioration to the natural flame-retardant properties of PVC.
9. Glass transition is reducing slightly due to increase in segmental mobility while the thermal stability is improving.
Example 2:
A PVC composition was prepared according to the table 5 below. Various properties of the PVC composition were measured. The results obtained are tabulated in Table 6.
Table 5: PVC Composition
Ingredient UOM Control 50:50 100% BSP
PVC Resin (K-67) % wt. 100 100 100
Heat Stabilizer (Ca – Zn) 2 2 2
Plasticizer (DINP) 90.5 90.5 90.5
Oxidized Polyethylene Wax 0.4 0.4 0.4
Stearic Acid 0.2 0.2 0.2
Barium Stearate 1 1 1
Calcium Stearate 0.5 0.5 0.5
CaCO3 41.5 20.75 0
Brine Sludge Powder 0 20.75 41.5

Table 6 - Summary of all results
Properties UOM Specifications Control 50:50 100% BSP
Specific Gravity -- 1.28 ± 0.03 1.30 1.29 1.29
Hardness Shore A 65 ± 3 62 65 66
Tensile Strength MPa 6 8.4 9.3 7.7
EB – Manual % 300 300 300 263
Thermal stability Minutes 15 28 30 30
With the replacement of CaCO3 with Brine Sludge Powder (BSP), as can be seen from the table above, except for elongation with 100% BSP sample rest all properties are within the specifications.

Specific Embodiments are disclosed as herein below:

A polyvinyl chloride (PVC) composition comprising:
a polyvinyl chloride resin in a range of 40 wt % to 70 wt %;
a plasticizer in a range of 10wt% to 40wt%;
a stabilizer in a range of 0.01wt% to 0.5wt%; and
a filler in a range of 15wt% to 50wt%,
wherein the filler comprises 20wt% to 100wt% brine sludge powder based on the total weight of the filler, and wherein the brine sludge powder has 2wt% to 5wt% moisture and a particle size distribution of D90 in a range of 50 to 500 µm..

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

Such polyvinyl chloride 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 polyvinyl chloride composition(s), wherein the plasticizer is selected from a group consisting of Diisononyl phthalate (DINP), Diisodecyl phthalate (DIDP), di(2- ethylhexyl) phthalate (DEHP) and a combination thereof.

Such polyvinyl chloride composition(s), wherein the stabilizer is selected from a group consisting of tribasic lead sulfate, dibasic lead phosphite, dibasic lead stearate, dibasic lead phthalate or basic lead sulfite, calcium zinc stabilizers, barium zinc stabilizer, barium cadmium stabilizer, barium cadmium zinc stabilizer, and cadmium zinc stabilizer.

Such polyvinyl chloride composition(s), wherein the composition comprises additives selected from a group comprising anti-static agents, anti-fogging agents, ultra-violet inhibitors, anti-oxidants, light stabilizers, fire retardants, pigments, whiteners and mixtures thereof.

Further specific embodiments are disclosed as herein below:

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

Such filler(s) for a polyvinyl chloride composition, 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%.

A method of preparing a filler for a polyvinyl chloride composition, the method comprising drying brine sludge to reduce the moisture content of the brine sludge to 2wt% to 5wt% to obtain dried brine sludge; and milling the dried brine sludge to obtain brine sludge powder with particle size distribution of D90 in a range of 50 to 500 µm..

Such method(s) of preparing a filler for a polyvinyl chloride composition, wherein the brine sludge is dried at 150oC for 2 to 6 hours.

INDUSTRIAL APPLICABILITY
The present disclosure provides a filler for a PVC 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 PVC composition is reduced. Moreover, the filler used results in a PVC 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 the flame properties along with thermal stability of base PVC resin. It is the various components that are present in the brine sludge that work in a synergistic manner to achieve these properties. Moreover, brine sludge has a reasonable amount of chloride content that allows to be used as a filler for thermoplastics such as PVC and related polymers. The PVC composition as disclose thus find use in variety of applications such as in adhesives and sealants, in coated fabrics, wire and cable coatings, foams, footwear, gaskets, inks, cosmetics, and medical devices. PVC-based applications include floor coverings, wallpaper, roofing membranes, tubing, inks, and calendared film 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 PVC composition down. , Claims:1. A polyvinyl chloride (PVC) composition comprising:
a polyvinyl chloride resin in a range of 40 wt % to 70 wt %;
a plasticizer in a range of 10wt% to 40wt%;
a stabilizer in a range of 0.01wt% to 0.5wt%; and
a filler in a range of 15wt% to 50wt%,
wherein the filler comprises 20wt% to 100wt% brine sludge powder based on the total weight of the filler, and wherein the brine sludge powder has 2wt% to 5wt% moisture and a particle size distribution of D90 in a range of 50 to 500 µm..
2. The polyvinyl chloride composition as claimed in claim 1, wherein the brine sludge powder comprises:
- Barium Sulphate in a range of 10 wt% to 55wt%;
- Calcium Carbonate in a range of 15wt% to 40wt%;
- Magnesium Hydroxide in a range of 10wt% to 30wt%;
- Sodium Chloride in a range of 5wt% to 20wt%;
- Sodium Carbonate in a range of 0.6wt% to 0.9wt%;
- Sodium Hydroxide in a range of 0.2wt% to 0.4wt%;
- Sodium Sulphate in a range of 0.1wt% to 0.3wt%; and
- moisture in a range of 2wt% to 5wt%.
3. The polyvinyl chloride 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 polyvinyl chloride composition as claimed in claim 1, wherein the plasticizer is selected from a group consisting of Diisononyl phthalate (DINP), Diisodecyl phthalate (DIDP), di(2- ethylhexyl) phthalate (DEHP) and a combination thereof.
5. The polyvinyl chloride composition as claimed in claim 1, wherein the stabilizer is selected from a group consisting of tribasic lead sulfate, dibasic lead phosphite, dibasic lead stearate, dibasic lead phthalate or basic lead sulfite, calcium zinc stabilizers, barium zinc stabilizer, barium cadmium stabilizer, barium cadmium zinc stabilizer, and cadmium zinc stabilizer.
6. The polyvinyl chloride composition as claimed in claim 1, wherein the composition comprises additives selected from a group comprising anti-static agents, anti-fogging agents, ultra-violet inhibitors, anti-oxidants, light stabilizers, fire retardants, pigments, whiteners and mixtures thereof.
7. A filler for a polyvinyl chloride composition, the filler comprising 20wt% to 100wt% brine sludge powder, wherein the brine sludge powder has 2% to 5% moisture and particle size distribution of D90 in a range of 50 to 500 µm. .
8. The filler for a polyvinyl chloride composition as claimed in claim 7, 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%.
9. A method of preparing a filler for a polyvinyl chloride composition, the method comprising drying brine sludge to reduce the moisture content of the brine sludge to 2wt% to 5wt% to obtain dried brine sludge; and milling the dried brine sludge to obtain brine sludge powder with particle size distribution of D90 in a range of 50 to 500 µm. .
10. The method of preparing the filler for a polyvinyl chloride composition as claimed in claim 9, wherein the brine sludge is dried at 150oC for 2 to 6 hours.