Polymeric composition and a method for preparation thereof

Abstract

The present disclosure relates to a tablet comprising at least one property modifying agent adapted to modify at least one property of a melt processable polymer and at least one processing aid having softening temperature lower than or equal to the melt processing temperature of the melt processable polymer.

Claims

1. A tablet adapted to modify at least one property of a melt processable polymer, said tablet comprising at least one property modifying agent and at least one processing aid having a softening temperature lower than or equal to the melt processing temperature of the melt processable polymer; wherein the amount of the processing aid is at least 0.005% with respect to the total mass of the tablet and the melt processing temperature of the melt processable polymer is higher than or equal to the initial degradation temperature of the property modifying agent.

2. The tablet as claimed in claim 1, wherein the property modifying agent is at least one selected from the group consisting of surfactants, polymerization modifiers, plasticizers, stabilizers, colorants, toners, antimicrobial agents, insect repellants, insecticides, catalysts, initiators, chain extenders, and cross linkers.

3. The tablet as claimed in claim 1, wherein the property modifying agent is at least one insect repellant selected from the group consisting of deltamethrin, permethrin, fenvalerate, cypermethrin, bifenthrin, resmethrin, sumethrin and n-octyl bicycloheptene dicarboximide.

4. The tablet as claimed in claim 1, wherein the property modifying agent is at least one synergist selected from the group consisting of piperonyl butoxide and n-octyl bicycloheptene dicarboximide.

5. The tablet as claimed in claim 1, wherein the property modifying agent is at least one insecticide and at least one synergist.

6. The tablet as claimed in claim 1, wherein the processing aid is at least one selected from the group consisting of carriers, binders, lubricants, glidants, dispersing agents and disintegrants; wherein the at least one carrier is selected from the group consisting of polymeric carriers, oligomeric carriers and monomeric carriers.

7. The tablet as claimed in claim 1, wherein the melt processable polymer is at least one polymer selected from the group consisting of polyethylene terephthalate, polypropylene, polyethylene, poly methyl methacrylate, polystyrene, polycarbonate, polyamide and high density polyethylene.

8. The tablet as claimed in claim 1, wherein the processing aid comprises at least one polymeric carrier selected from the group consisting of Acrylonitrile butadiene styrene (ABS), Cellulose acetate, Cellulose, Ethyl cellulose, Fluoroplastics (PTFE) Cyclic Olefin Copolymer (COC), Ethylene-Vinyl Acetate (EVA), acrylic/PVC alloy, Ethylene vinyl alcohol (EVOH), Liquid Crystal Polymer (LCP), Polyoxymethylene (POM or Acetal), Polyacrylates (Acrylic), Polyacrylonitrile (PAN or Acrylonitrile), Polyaryletherketone (PAEK or Ketone), Polybutylene terephthalate (PBT), Polycaprolactone (PCL), Polychlorotrifluoroethylene (PCTFE), Polyethylene terephthalate (PET), Polycyclohexylenedimethylene terephthalate (PCT), Polyhydroxyalkanoates (PHAs), Polyketone (PK) Polyester, Polyethylene (PE), Polyetheretherketone (PEEK), Polyetherketoneketone (PEKK), Polyethersulfone (PES)/Polysulfone, Chlorinated Polyethylene (CPE), Polylactic acid (PLA), Polymethylpentene (PMP), Polyphenylene oxide (PPO), Polyphenylene sulfide (PPS), Polypropylene (PP), Polystyrene (PS), Polysulfone (PSU), Polytrimethylene terephthalate (PTT), Polyvinyl acetate (PVAc), Polyvinyl alcohol (PVA), Polyvinyl chloride (PVC), Polyvinylidene chloride (PVDC), High Density Polyethylene (HDPE), Low Density Polyethylene (LDPE), Polyvinyl Chloride (PVC), Polymethylmethacrylate (PMMA), p-Polycarbonate (PC), Polyaryletherketone (PAEK) and Self-reinforced polyphenylene (SRP), Polyvinylidene chloride (PVDC), Styrene-acrylonitrile (SAN), Polychlorotrifluoroethylene (PCTFE), Thermoplastic polyurethanes, Phenol-formaldehyde resin, Para-aramid, Polychloroprene, Polyimide, aromatic polyester, poly-p-phenylene-2,6-benzobisoxazole (PBO), Polyethylene glycol (PEG), Polyurethane (PU), Polyvinylidene fluoride (PVDF) and Ethylene methyl acrylate.

9. The tablet as claimed in claim 1, wherein the processing aid consists of at least one binder selected from the group consisting of Glucose, sorbitol Mannitol, Sorbitol, Fructose, Maltose, xylitol, maltitol, sucrose, lactose, starch, cellulose, microcrystalline cellulose, hydroxypropyl cellulose (HPC); Ethyl cellulose, methyl cellulose, carboxy methyl cellulose, gelatin, polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), poly vinyl alcohol (PVA), Polymethycrylate, Calcium phosphate, Camphor, naphthalene, wax and water.

10. A tablet adapted to modify at least one property of a melt processable polymer, said tablet comprising at least one property modifying agent and at least one processing aid having a softening temperature lower than or equal to the melt processing temperature of the melt processable polymer; wherein, melt processing temperature of said melt processable polymer is higher than or equal to the initial degradation temperature of said property modifying agent; the amount of said processing aid is at least 0.005% with respect to the total mass of said tablet; and said processing aid is at least one oligomeric carrier selected from the group consisting of macrocyclic polycarbonates oligomer, macrocyclic polyesters oligomer, macrocyclic polyimides oligomer, macrocyclic polyetherimide oligomer, macrocyclic polyphenylene ether-polycarbonate co-oligomers, macrocyclic polyetherimide-polycarbonate co-oligomers.

11. A tablet adapted to modify at least one property of a melt processable polymer, said tablet comprising at least one property modifying agent and at least one processing aid having softening temperature lower than or equal to the melt processing temperature of the melt processable polymer; wherein, melt processing temperature of said melt processable polymer is higher than or equal to the initial degradation temperature of said property modifying agent; the amount of said processing aid is at least 0.005% with respect to the total mass of said tablet; and said processing aid is at least one monomeric carrier selected from the group consisting of glucose, sorbitol, mannitol, fructose, maltose, xylitol, maltitol, sucrose, lactose, calcium phosphate, naphthalene, camphor, calcium stearate, magnesium stearate, sodium stearate, fumed silica, calcium carbonate, magnesium carbonate, carbon black, diatomaceous earth, magnesium silicate, calcium silicate, sodium silicate, alumina and wax.

Description

DETAILED DESCRIPTION

(1) The present disclosure is directed to solve the problem associated with the loss and/or degradation and/or denaturation of the property modifying agent during the preparation of a property modified composition. This is accomplished by formulating a tablet of the property Modifying agent(s) and then incorporating it into a melt processable polymer.

(2) One of the distinct advantages associated with the tablet of the present disclosure is that it allows the incorporation of property modifying agents in the polymer even in trace amounts.

(3) In accordance with one aspect of the present disclosure there is provided a tablet containing one or more property modifying agents along with processing aid. The amount of the processing aid is greater than or equal to 0.005% with respect to the total mass of the tablet.

(4) In accordance with another aspect of the present disclosure there is provided a method for preparation of the tablet. The method involves mixing of at least one property modifying agent and at least one processing aid to obtain a pre-mix and subjecting the pre-mix to a mechanical compression or compaction to obtain a tablet.

(5) The property modifying agent used to prepare the tablet of the present disclosure are selected from surfactants, polymerization modifiers, plasticizers, stabilizers, cross-linkers, antimicrobial agents, insect repellents, insecticides catalyst, initiators, chain extenders, colorants, toners and the combinations thereof.

(6) The aforementioned insect repellant includes but is not limited to deltamethrin, permethrin, fenvalerate, cypermethrin, bifenthrin, resmethrin, sumethrin and n-octyl bicycloheptene dicarboximide.

(7) In one of the exemplary embodiments, the tablet contains deltamethrin as insect repellent.

(8) In another exemplary embodiment, the tablet contains insect repellent in combination with the synergist as the property modifying agent.

(9) The synergist includes but is not limited to piperonyl butoxide and n-octyl bicycloheptene dicarboximide.

(10) The processing aid used to prepare the tablet of the present disclosure is classified into various categories such as carrier, binders, diluents, lubricants, glidants, dispersing agents, disintegrants and combinations thereof.

(11) The selection of appropriate processing aid necessitates temperature conditions such as softening temperature of the processing aid should be lower than or equal to the melt processing temperature of the melt processable polymer and furthermore said softening temperature should be higher than the initial degradation temperature of the property modifying agent.

(12) One of the processing aids used in the tablet of the present disclosure is carrier and it is further classified as monomeric carrier, oligomeric carrier and polymeric carrier.

(13) The monomeric carrier includes glucose, sorbitol, mannitol, sorbitol, fructose, maltose, xylitol, maltitol, sucrose, lactose, calcium phosphate, naphthalene, camphor, calcium stearate, magnesium stearate, sodium stearate, fumed silica, calcium carbonate, magnesium carbonate, carbon black, diatomaceous earth, magnesium silicate, calcium silicate, sodium silicate, alumina, wax and combinations thereof.

(14) The oligomeric carrier used in the tablet includes macrocyclic polycarbonates oligomer, macrocyclic polyesters oligomer, macrocyclic polyimides oligomer, macrocyclic polyetherimide oligomer, macrocyclic polyphenylene ether-polycarbonate co-oligomers, macrocyclic polyetherimide-polycarbonate co-oligomers and combinations thereof.

(15) The polymeric carrier includes Acrylonitrile butadiene styrene (ABS), Cellulose, Cellulose acetate, Ethyl cellulose, Fluoroplastics (PTFE) Cyclic Olefin Copolymer (COC), Ethylene-Vinyl Acetate (EVA), acrylic/PVC alloy, Ethylene Vinyl Alcohol (EVOH), Liquid Crystal Polymer (LCP), Polyoxymethylene (POM or Acetal), Polyacrylates (Acrylic), Polyacrylonitrile (PAN or Acrylonitrile), Polyaryletherketone (PAEK or Ketone), Polybutylene terephthalate (PBT), Polycaprolactone (PCL), Polychlorotrifluoroethylene (PCTFE), Polyethylene terephthalate (PET), Polycyclohexylenedimethylene terephthalate (PCT), Polyhydroxyalkanoates (PHAs), Polyketone (PK) Polyester, Polyethylene (PE), Polyetheretherketone (PEEK), Polyetherketoneketone (PEKK), Polyethersulfone (PES)/Polysulfone, Chlorinated Polyethylene (CPE), Polylactic acid (PLA), Polymethylpentene (PMP), Polyphenylene oxide (PPO), Polyphenylene sulfide (PPS), Polypropylene (PP), Polystyrene (PS), Polysulfone (PSU), Polytrimethylene terephthalate (PTT), Polyvinyl acetate (PVAc), Polyvinyl alcohol (PVA), Polyvinyl chloride (PVC), Polyvinylidene chloride (PVDC), High Density Polyethylene (HDPE), Low Density Polyethylene (LDPE), Polyvinyl Chloride (PVC), Polymethylmethacrylate (PMMA), p-Polycarbonate (PC), Polyaryletherketone (PAEK) and Self-reinforced polyphenylene (SRP), Polyvinylidene chloride (PVDC), Styrene-acrylonitrile (SAN), Polychlorotrifluoroethylene (PCTFE), Nylon, Teflon, Thermoplastic polyurethanes, Phenol-formaldehyde resin, Para-aramid, Polychloroprene, Polyimide, aromatic polyester, poly-p-phenylene-2,6-benzobisoxazole (PBO), Polyethylene glycol (PEG), Polyurethane (PU), Polyvinylidene fluoride (PVDF), Ethylene methyl acrylate and combinations thereof.

(16) The binder includes glucose, sorbitol mannitol, sorbitol, fructose, maltose, xylitol, maltitol, sucrose, lactose, starch, cellulose, microcrystalline cellulose, hydroxypropyl cellulose, ethyl cellulose, methyl cellulose, carboxy methyl cellulose, gelatin, polyvinylpyrrolidone, polyethylene glycol, poly vinyl alcohol polymethycrylate, calcium phosphate, camphor, naphthalene, wax, water and combinations thereof.

(17) In accordance with yet another aspect of the present disclosure, a property modified composition is prepared by incorporating one or more tablets into one or more melt processable polymers to obtain a polymeric mix. The tablet is incorporated into the melt processable polymer without being heated or melted. This polymeric mix is further processed in a melt processing machine at a temperature which is higher than either the softening temperature or the melting temperature of the melt processable polymer to obtain a property modified composition.

(18) In one embodiment of the present disclosure the tablet is mixed with the melt processable polymer before melting the melt processable polymer.

(19) In another embodiment of the present disclosure the tablet is mixed with the melt processable polymer after melting the melt processable polymer.

(20) The melt processable polymer in which said table is being incorporated is selected from polyethylene terephthalate, polypropylene, polyethylene, poly methyl methacrylate, polystyrene, polycarbonate, polyamide, high density polyethylene and combinations thereof.

(21) In accordance one embodiment of the present disclosure the carrier and the melt processable polymer are selected from polyethylene terephthalate, polypropylene, polyethylene, poly methyl methacrylate, polystyrene, polycarbonate, polyamide, high density polyethylene and combinations thereof.

(22) The melt processing machine used to prepare the property modified composition includes but is not limited to melt spinning, blow molding, extrusion blow molding, stretch blow molding, compression molding, injection molding, film casting, film extrusion, electro spinning, injection molding, compression molding, transfer molding, extrusion molding, blow molding, dip molding, rotational molding, thermoforming, laminating, expandable bead molding, foam molding, vacuum plug assist molding, pressure plug assist, matched mold, shrink fitting, shrink wrapping, die casting, rotational molding, thermoforming, blown film extrusion, over jacketing extrusion, tubing extrusion, co-extrusion, extrusion coating, and compounding.

(23) In accordance the present disclosure the property modified composition is obtained as a molten composition or a solid composition or a molded composition.

(24) In accordance the present disclosure the property modified composition may also be obtained in the form of chips, flaks, sheets, fibers, filaments, yarns, films or extrusions.

(25) In accordance with still another aspect of the present disclosure an article is configured by using the property modified composition.

(26) In one embodiment of the present disclosure the property modified composition is in the form of fibers and the article is a woven or non-woven fabric configured from said fibers.

(27) In one embodiment the article of the present disclosure contains a core layers and a sheath layers and theses layers are prepared by using the melt processable polymer containing one or more tablets.

(28) In another embodiment of the present disclosure the core and the sheath of the article is prepared by using same melt processable polymer containing one or more tablets.

(29) In another embodiment of the present disclosure the core and the sheath of the article is prepared by using different melt processable polymers and one or more said melt processable polymer contains one or more tablets.

(30) In yet another embodiment of the present disclosure the article is a bicomponent filament having the core and the sheath prepared by using same melt processable polymers containing one or more tablets.

(31) In still another embodiment of the present disclosure the article is a bicomponent filament having the core and the sheath prepared by using different melt processable polymer and one or more said melt processable polymer contains one or more tablets.

(32) The disclosure will now be described with the help of the following non-limiting examples. Although the example discloses the deltamethrin as a property modifying agent, person ordinarily skilled in the art can explore these examples for preparing a tablet by using other property modifying agents.

COMPARATIVE EXAMPLE

(33) 5 parts Deltamethrin powder and 95 parts Polyethylene terephthalate (PET) powder (0.80 IV) were premixed, dried at 80 C. in vacuum oven and extruded through twin screw extruder to get 5% Deltamethrin master batch. Extruder temperatures were in the range of 265 C. to 285 C. This master batch was used for making 130/36 denier partially oriented yarn (POY). Standard SD PET was used for making POY.

(34) TABLE-US-00001 TABLE 1 POY details 130/36-POY 130/36-POY Denier/Filament/cross section Round Round Polymer SDPET SDPET DeltamethrinMB LDR 4 10

(35) Determination of Deltamethrin in POY

(36) POY was textured for making mosquito repellent nets. Deltamethrin Master Batch (MB) and textured yarn were tested for Deltamethrin content. Samples (0.5 g chips/1.0 g yarn) were dissolved in 10 ml Hexafluoroisopropanol (HFIP) & solution was diluted with 10 ml chloroform. The diluted solution was added to 50 ml Acetone under stirring to precipitate PET. Solution was filtered through GFC paper and filtrate was evaporated to obtain Deltamethrin residue. Residue was dissolved in carbon tetra chloride and volume was adjusted to 4 ml. Solution was filtered through GFC paper and FTIR spectra was recorded. Area of peak at 1488 cm1 was calculated, to determine deltamethrin concentration using a calibration based on use of known amounts of deltamethrin (0.25% to 2.5% solution).

(37) TABLE-US-00002 TABLE 2 Determination of Deltamethrin in POY Deltamethrin conc. Deltamethrin conc. (%) Sample Identity (%) expected measured Deltamethrin (MB) 5.0% 4.3 (14% loss) POY containing 10% 0.43% 0.343 (20.2% loss) Deltamethrin (MB) POY containing 4% 0.172% 0.13 (24.4% loss) Deltamethrin MB

(38) There was a 14% loss in deltamethrin content during masterbatch making and 20-24% loss in Deltamethrin content during POY spinning by due to evaporation at high temp.

Example 1

(39) 5 parts deltamethrin powder & 95 parts HDPE powder (18MFI) were mixed to obtain a premix. The premix was then compacted to obtain a HDPE tablet having avg. diameter of 8 mm and avg. weight of 200 mg. Since the tablet making was carried out at temperature of 25 C., there was no loss of deltamethrin due to evaporation.

(40) HDPE tablets were then incorporated into the melt processable polymer,

(41) HDPE at a temperature of 190 C. to obtain a property modified composition containing 1% deltamethrin. The composition was then extruded through an extruder to obtain a bi-component FDY containing a sheath of the property modified composition and a core of polyethylene terephthalate (PET)

(42) TABLE-US-00003 TABLE 3 Fully Drawn Yarn (FDY) details: Cross Section Geometry Sheath/Core Round Proportion 25/75 (HDPE/PET) Den/Fil 50/24

(43) Determination of Deltamethrin in FDY

(44) FDY sample was refluxed at a temperature of 140 C. in 40 ml xylene for 1 hr. and was then cooled at a temperature of 25 C. and filtered by using GFC filter paper. Filtrate was diluted to 50 ml with xylene and injected in GC for determination of percentage of detamethrin in FDY. Std. Deltamethrin solution was prepared by dissolving pure deltamethrin powder in xylene.

(45) TABLE-US-00004 TABLE 4 Determination of Deltamethrin in FDY Sample Identity Deltamethrin conc. (%) FDY containing 1% Deltamethrin 0.238 in a Sheath (Total Deltamethrin (4.8% Deltamethrin loss) concentration in Bicomponent FDY = 0.25%)

(46) Since the tablet preparation process was carried out at temperature of 25 C. by mechanical compression, there was no loss of Deltamethrin. During Bicomponent FDY spinning there was 4.8% loss in deltamethrin content compared to 20% to 24% loss during polyester POY.

Example 2

(47) 50 parts deltamethrin powder & 50 parts polyvinyl pyrrolidone powder (PVP K 30) were mixed to obtain a premix. The premix was then compacted to obtain a polyvinyl pyrrolidone tablet having avg. diameter of 5 mm and avg. weight of 50 mg. Since the tablet making was carried out at temperature of 25 C., there was no loss of deltamethrin due to evaporation. Polyvinyl pyrrolidone tablets were then incorporated into the melt processable polymer, polyethylene at a temperature of 190 C. to obtain a property modified composition containing 1% of detamethrin. The composition was then extruded through extruder to obtain a bi-component FDY containing a core of polyethylene terephthalate and a sheath of the property modified composition.

(48) TABLE-US-00005 TABLE 3 Fully Drawn Yarn (FDY) details: Cross Section Sheath/Core Geometry Round Proportion 25/75 (PE/PET) Den/Fil 70/36

(49) Determination of Deltamethrin in FDY

(50) FDY sample was refluxed at a temperature of 140 C. in 40 ml xylene for 1 hr. and was then cooled at a temperature of 25 C. and filtered by using GFC filter paper. Filtrate was diluted to 50 ml with xylene and injected in GC for determination of percentage of detamethrin in FDY. Std. Deltamethrin solution was prepared by dissolving pure deltamethrin powder in xylene.

(51) TABLE-US-00006 TABLE 4 Determination of Deltamethrin in FDY Sample Identity Deltamethrin conc. (%) FDY containing 1% Deltamethrin 0.233 in a Sheath (Total Deltamethrin (6.8% Deltamethrin loss) concentration in Bicomponent FDY = 0.25%)

(52) Since the tablet preparation process was carried out at temperature of 25 C. by mechanical compression, there was no loss of Deltamethrin. During Bicomponent FDY spinning there was 6.8% loss in deltamethrin content compared to 20% to 24% loss during polyester POY.

Example 3

(53) 80 parts deltamethrin powder & 20 parts ethyl cellulose powder (ethyl cellulose grade M 10) were mixed to obtain a premix. The premix was then compacted to obtain a deltamethrin tablet having avg. diameter of 4.5 mm and avg. weight of 50 mg. Since the tablet making was carried out at temperature of 25 C., there was no loss of deltamethrin due to evaporation.

(54) Deltamethrin tablets were then incorporated into a melt processable polymer, polyethylene at a temperature of 190 C. to obtain a property modified composition containing 1% detamethrin. The composition was then extruded through extruder to obtain a bi-component FDY containing a core of polyethylene terephthalate and a sheath of the property modified composition.

(55) TABLE-US-00007 TABLE 3 Fully Drawn Yarn (FDY) details: Cross Section Geometry Sheath/Core Round Proportion 25/75 (PE/PET) Den/Fil 70/36

(56) Determination of Deltamethrin in FDY

(57) FDY sample was refluxed at a temperature of 140 C. in 40 ml xylene for 1 hr. and was then cooled at a temperature of 25 C. and filtered by using GFC filter paper. Filtrate was diluted to 50 ml with xylene and injected in GC for determination of percentage of detamethrin in FDY. Std. Deltamethrin solution was prepared by dissolving pure deltamethrin powder in xylene.

(58) TABLE-US-00008 TABLE 4 Determination of Deltamethrin in FDY Sample Identity Deltamethrin conc. (%) FDY containing 1% Deltamethrin 0.241 in a Sheath (Total Deltamethrin (3.6% Deltamethrin loss) concentration in Bicomponent FDY = 0.25%)

(59) Since the tablet preparation process was carried out at temperature of 25 C. by mechanical compression, there was no loss of Deltamethrin. During Bicomponent FDY spinning there was 3.6% loss in deltamethrin content compared to 20 to 24% loss during polyester POY.

Example 4

(60) 80 parts deltamethrin powder & 20 parts poly ethylene glycol (PEG 6000) were mixed to obtain a premix. The premix was then compacted to obtain a deltamethrin PEG tablet having avg. diameter of 4.5 mm and avg. weight of 50 mg. Since the tablet making was carried out at temperature of 25 C., there was no loss of deltamethrin due to evaporation.

(61) Deltamethrin tablets were then incorporated into the melt processable polymer, polyethylene at a temperature of 190 C. to obtain a property modified composition containing 1% detamethrin. The composition was extruded through extruder to obtain a bi-component FDY containing a core of polyethylene terephthalate and a sheath of the property modified composition.

(62) TABLE-US-00009 TABLE 3 Fully Drawn Yarn (FDY) details: Cross Section Geometry Sheath/Core Round Proportion 25/75 (PE/PET) Den/Fil 70/36

(63) Determination of Deltamethrin in FDY

(64) FDY sample was refluxed at a temperature of 140 C. in 40 ml xylene for 1 hr. and was then cooled at a temperature of 25 C. and filtered by using GFC filter paper. Filtrate was diluted to 50 ml with xylene and injected in GC for determination of percentage of detamethrin in FDY. Std. Deltamethrin solution was prepared by dissolving pure deltamethrin powder in xylene.

(65) TABLE-US-00010 TABLE 4 Determination of Deltamethrin in FDY Sample Identity Deltamethrin conc. (%) FDY containing 1% Deltamethrin 0.236 in a Sheath (Total Deltamethrin (5.6% Deltamethrin loss) concentration in Bicomponent FDY = 0.25%)

(66) Since the tablet preparation process was carried out at temperature of 25 C. by mechanical compression, there was no loss of Deltamethrin. During Bicomponent FDY spinning there was 5.6% loss in deltamethrin content compared to 20 to 24% loss during polyester POY.

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

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

(69) Throughout this specification the word comprise, or variations such as comprises or comprising, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

(70) The use of the expression at least or at least one suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.

(71) When an amount, concentration, or other value or parameter is given as a range, or a list of upper and lower values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper and lower range limits, regardless of whether ranges are separately disclosed. Where a range of numerical values is recited herein, unless otherwise stated, the range is intended to include the endpoints thereof, and all integers and fractions within the range. It is not intended that the scope of the present disclosure be limited to the specific values recited when defining a range.

(72) When the term about is used in describing a value or an end-point of a range, the disclosure should be understood to include the specific value or end-point referred to.