FIELD OF THE INVENTION
[0001] The present invention relates to a formulation for flame retardance and UV resistance particularly for wires and cables. More particularly, the invention deals with a formulation for flame retardant and UV resistant insulation, free of antimony compounds.
BACKGROUND OF THE INVENTION
[0002] Flexible polyvinyl chloride (PVC) has been the material of choice for cable sheathing for many years due to economics and material properties of PVC. PVC has excellent mechanical and electrical properties and readily tolerates a wide range of additives. PVC is commonly used as the insulation on electrical cables; PVC used for this purpose need to be plasticized that is making PVC softer and flexible. A sizable fraction of ignitions of structures of wires and cables are due to electrical faults associated with wiring or with wiring devices. To prevent electrical faults, wires and cables have to be coated with flame retardant PVC. Flame retardant PVC has been well documented and traditionally includes additives such as antimony trioxide. Flame retardance can also be improved by replacing phthalate plasticisers with less flammable chlorinated waxes or phosphate esters. The main disadvantages with PVC are secondary fire characteristics, that are minor and do not include any property damage, for example smoke and corrosive acid gas emission,.
[0003] The choice of flame retardants for wires and cables in some appliances is largely dependent on the desired physical and electrical properties of the final insulation material. The flame retardant resin compositions used in cables and wires are well known as shown in Indian patent application no 3060/CHENP/2012. PVC itself has relatively low flammability due to its chlorine content. Inorganic synergists such as antimony trioxide have been added to enhance fire safety performance of the PVC resin. But the major drawback of adding antimony trioxide is that it reacts with evolving HCl when PVC catches fire, thus forming trioxide oxychlorides which then decomposes to antimony trichloride. Antimony trichloride has a boiling point of 283oC and it is apprehended that it participates in the gas phase during combustion of PVC, thus introducing an additional source of chlorine into flame. This increases the smoke level in the atmosphere. Essentially this is the reason as to how the use of antimony trioxide in PVC generally elevates the smoke level and such smoke is hazardous to safety of the human being during fire, besides pollution.

[0004] There have been many prior disclosures teaching use of antimony trioxide. Patent no. US5, 891,571 and many others describe fire resistant PVC formulation comprising antimony trioxide.
[0005] Flame retardant resin compositions have been used in the past. Patent publication no. US20030166812 describes a flame retardant made of phosphazene having a polymerizable functional group with a resin.
[0006] Patent no. CN1052211 and Patent no. WO9101348A1 describe fire resistant formulations that are smoke suppressants containing halogen free flame retardants and stannates.
[0007] Patent no. CN104558937A describes epoxidized-soybean-oil ultraviolet-resistant PVC cable sheath containing antimony oxide as its constituent.
[0008] To enable wires to be easily and safely identified, wiring safety codes generally mandate a colour scheme for the insulation on wires and cables. It is known that continuing exposure of ultra violet (UV) irradiation on several engineering plastics and rubbers cases leads to fading of the colour with time. Source of such irradiation are sunlight, gadgets like tube lights, et cetera. Such an unintended colour change DUE TO UV irradiation would be a serious safety hazard for example, a wire with black or red coloured insulation may turn greyish and someone may mistake it to a ground conductor and consequent wrong connection may lead to shock, fire and or other accident. Thus it is important that the wires retain their original colour for the life span for the use of the cables and wires as most common and neglected cause of breakdown is penetration of UV rays. UV problem has been a subject of concern in the past and this has been attempted to solve, for example, in the Indian Patent application no 1301/DEL/2014. The said patent applications has identified the problem of UV radiation on the life of cables and its colour degradation but haven’t provided an effective solution by giving a composition that could combat UV radiation.
[0009] Cables exposed to water, also have the challenge of preventing the possible ingress of water, in the case of underground cables, or sea water in the case of submarine cables), or from atmospheric humidity). Water ingress in multicore cables causes short circuit consequent to imperfect impermeability of insulation of the cable.
[0010] Thus there is a need in the art to find efficient alternative flame retardant agents which are able to replace antimony trioxide or antimony based compounds in PVC formulations due to its inherent disadvantages and resistant to any changes in presence of UV light. It is also necessary to find a solution which envisages not only the absorption of water inside cable but also the permeability from the outer coating.
OBJECT OF THE INVENTION
[0011] The object of the present invention is to provide a flame retardant compound that can be used as flame retardant agent in PVC formulations and which is able to completely replace antimony trioxide or any other antimony based compound in the same formulations, still maintaining the desired flame retardant characteristics.

[0012] Another object of the present invention is to provide flame retardant PVC formulations having reduced smoke density.

[0013] Another object of the present invention is to provide flame retardant PVC formulations that prevent the absorption of moisture into the cables and wires.

[0014] Still another object of the present invention is to provide wires and cables that do not degrade in color when exposed to UV radiation.

SUMMARY
[0015] The present invention yields a flame retardant compound with UV resistance that is used as flame retardant agent in PVC formulation comprising PVC resin, at least one plasticizer from a primary plasticizer or and a secondary plasticizer, at least one flame retardant agent primary Flame Retardant (FR) plasticizer or and secondary Flame Retardant (FR) plasticizer, stabilizers, co-stabilizers, metal hydrate, lubricants, fillers, colorants, catalysts, desiccants and other conventional additives wherein the PVC resin and at least one plasticizer includes at least one phthalate plasticizer and wherein, the phthalate plasticizer and the flame retardant compound are present in a total amount effective to render the formulation capable of passing the flame-resistant requirements of wires and cables that are free of antimony based or antimony flame retardant compounds.
[0016] Also included in the present invention is a method for limiting the absorption of water by a cable, characterized in that a predetermined quantity of Zeolite is added to at least one coating layer of said cable.
[0017] A catalyst is added to make a reaction occur faster and primarily increasing the rate of reaction. Tetra- butyl ammonium bromide (TBAB) is one such catalyst used in the present invention which not only acts as a catalyst but also prevents hygroscopy i.e. the ability of a PVC formulation to attract and hold water molecules from the surrounding environment.
[0018] Primarily, PVC Resin at 40 ~ 50 ? is masticated i.e. grinded in a mixer for 5 to 6 minutes. Subsequently adding semi-reinforcing activated carbon black, calcium carbonate, Ca-Zn stabilizer, Chlorinated paraffin, and then subsequently adding aluminium trihydrate, TiO2, Zinc Borate, Magnesium hydroxide, Zeolite, Di Octyl Phthalate, epoxidized soya bean oil, Tetra- butyl ammonium bromide. All the above constituents are thereafter kneaded for 25 to 30 minutes into a dough or pulp form, maintaining the temperature in the mixer to 90 ~ 100 ?. The optimum time required for kneading the mixture is 30 minutes. This mixture is intimately mixed in a mixer at the application of the total composition to an object, such as surface of concrete or metal.
[0019] The resultant flame retardant formulations are free from antimony trioxide, have reduced smoke density, with no sign of cracks or scales as well as no colour change of the wires and cables when exposed to sunlight.
BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure-1 gives a matrix of various constituents and additives contributing to flame retardance.

[0021] Figure-2 gives a flow diagram of the first embodiment giving the constituents and method for making flame retardant UV resistant formulation

[0022] Figure -3 gives a flow diagram of the second embodiment giving the constituents and method for making flame retardant UV resistant formulation

DETAILED DESCRIPTION OF THE INVENTION
[0023] Referring to Figure 2 and Figure 3, the essential ingredients for flame retardance and UV resistance for wires and cables formulation are: a PVC resin (1), at least one plasticizer from a primary plasticizer or and a secondary plasticizer, at least one flame retardant agent i.e. primary Flame Retardant (FR) plasticizer or and secondary Flame Retardant (FR) plasticizer, stabilizers, co-stabilizers, metal hydrate, lubricants, fillers, colorants, catalysts, desiccants and other conventional additives wherein the PVC resin(1) and at least one plasticizer (primary or secondary) includes at least one phthalate plasticizer and wherein, the phthalate plasticizer and the flame retardant agent are present in a total amount effective to render the formulation capable of passing the flame-resistant requirements of wires and cables that are free of antimony based or antimony flame retardant compounds.
[0024] PVC resin - (1)
There are different kinds of PVC resins grouped together according to the polymerization method used for their production: suspension grade PVC, emulsion grade PVC, bulk polymerized PVC, copolymer PVC, chlorinated PVC (CPVC). Suspension grade PVC is the most widely prevalent type, obtained by polymerizing droplets of vinyl chloride in the monomer form suspended in water. When polymerization is complete, the slurry is centrifuged and the PVC cake thus obtained is gently dried by special heating systems in order to avoid heat degradation of the un-stabilized resin. Particles have porous structures which readily absorbs plasticizers. The structure of the PVC particles can be modified by selecting suitable suspending agents and polymerization catalyst. Less porous types are extensively used for the high volume rigid or un-plasticized PVC applications like PVC pipes, windows, sidings, ductings. Suspension grades of a coarser particle size and very porous structures are able to absorb large quantities of plasticizer instead, thus forming a dry blend at relatively low temperatures, such as, for example, 80°C. Emulsion grade PVC corresponds to paste grade resin and is almost exclusively used for plastisols. Paste grade resin is a very fine particle size PVC produced by spray drying an emulsion of PVC in water. Paste grade resin needs much more energy to be produced and is considerably much expensive than suspension resin. The paste grade resin carries the emulsifying chemicals and catalysts within. It is therefore less pure than suspension polymerized or bulk polymerized PVC. The electrical properties of paste grade resin plastisols are therefore much poorer than suspension resin compounds. Clarity is poorer than the same parameter in suspension or bulk PVC. Paste grade resin is compact in structure, and does not absorb much plasticizer at room temperatures. Temperatures exceeding 160-180°C are needed to drive the plasticizer into the resin during curing.
[0025] Bulk polymerized PVC is obtained by polymerization that gives the purest form of PVC resin as no emulsifying or suspending agents are used. The PVC formulations thus obtained are mainly used in transparent applications. They are mainly made available in the lower K value groups.
[0026] Copolymer PVC is obtained when vinyl chloride is copolymerized with co- monomers such as, for example, vinyl acetate to give a range of resins with unique properties, and they are used in adhesive or coatings.
[0027] PVC Resins (1) are classified by their K-Value, an indicator of the molecular weight and degree of polymerization.
[0028] K70-75 is high K value resins which give best mechanical properties but are more difficult to process. They need more plasticizer for same softness.
[0029] K65-68 is medium K value resins which are the most popular. They have a good balance of satisfactory mechanical properties and process ability.
[0030] K58-60 is low K- value resins. Their mechanical properties are not so satisfactory, but their processing is easiest.
[0031] K50-55 is special resins which are specially made for some demanding applications. Processing is easiest.
[0032] Polymer PVC Resin (1) having K value 70 is used in the present invention.
[0033] Chlorinated PVC (CPVC) is PVC that has been chlorinated via a free radical chlorination reaction. This reaction is typically initiated by application of thermal or UV energy utilizing various approaches. In the process, chlorine gas is decomposed into free radical chlorine which is then reacted with PVC in a post-production step, essentially replacing a portion of the hydrogen in the PVC with chlorine. Depending on the method, a varying amount of chlorine is introduced into the polymer allowing for a measured way to fine tune the final properties. The chlorine content may vary from manufacturer to manufacturer; the base can be as low as PVC 56.7% to as high as 74% by mass, although most commercial CPVC resins have chlorine content from 63% to 69%.
[0034] Primary plasticizers
A plasticizer material for plastics formulations that has sufficient affinity to a polymer or resin so that it is considered compatible and therefore may be used as the sole plasticizer is called as primary plasticizer. The present invention uses at least one plasticizer. Plasticizers make the hard PVC resin softer. Primary plasticizers have good compatibility with PVC resins and can be absorbed in large quantities. In special cases up to 140-150 phr of primary plasticizer can be put into PVC formulations for extremely soft products. Phr is defined as part by weight of ingredient per 100 parts of PVC resin. Nearly all plasticizers are liquids and have to be absorbed in suspension resins through heated mixers. High speed mixers (which generate frictional heat while mixing) are the most popular types of dry-blending equipment. Mastication is one such option that can be used for blending the resin in a suitable form. There is a vast choice of primary plasticizers for PVC. Some of the requirements plasticizers must satisfy are the following: high compatibility with PVC, good plastic properties, low volatility, good ageing properties, electrolyte-free.
[0035] The most popular primary plasticizers are phthalate esters. Phthalic acid is reacted with various alcohols to produce a family of phthalates which can be used as primary plasticizers among which Di Octyl Phthalate (DOP) (11) is the most popular. The primary plasticizer is selected among Di Octyl Phthalate (DOP) (11), Di isononyl phthalate (DINP), Tri Octyl trimellitate (TOTM), Di isodecyl phthalate (DIDP), Di isotridecyl phthalate (DITP). Other important primary plasticizers are the following:
DINP = Diisononylphthalate
TOTM = Trioctyltrimellitate
DIDP= Diisodecylphthalate
DITP = Diisotridecylphthalate
[0036] PVC compounds which need low temperature resistance can be prepared in combination with phthalic acid esters and dicarboxylic acids such as Dioctyladipate (DOA), Dioctylazelate (DOZ) or Dioctylsebacate (DOS). The number of carbon atoms in the alcohol is important for the modification of properties.
[0037] Primary FR (Flame Retardant) plasticizers
Alkyl aryl phosphate esters can be optionally used as an additional constituent in the present invention. Flame retardant plasticizer based on phosphate esters effectively replace and avoid the use of the most flammable component, i.e. the plasticizer itself. Commonly available phosphate ester plasticizers are of three major types: triaryl phosphates, alkyl diaryl phosphates, and their mixtures. Although most phosphate ester plasticizers can be used as primary plasticizers, they are usually blended with lower costly phthalate ester plasticizers to obtain the desired performances at a minimum loading. The blend is required because they are quite expensive than standard plasticizers, and also because they are characterized by poor low temperatures properties. They have the additional advantage of being non-pigmenting and hence clear flame retardant formulations can be obtained.
[0038] Secondary plasticizers (or extenders)
For price optimization of PVC formulations, secondary plasticizers (also indicated as extenders) such as aromatic hydrocarbons or paraffin oils are used. Secondary plasticizers are not possible to be used as the only plasticizer in PVC, because of low compatibility causing migration and poor low temperature properties, so they have to be used together with primary plasticizers. In the current invention secondary plasticizer can be used along with Di Octyl Phthalate (DOP) which the primary plasticizer.
[0039] Secondary FR (Flame Retardant) plasticizer
Secondary plasticizers containing halogen such as chlorinated paraffin (5) or chlorinated oils are used. Chlorinated paraffin (5) or oils also act as flame retardant. Chlorinated paraffin (5) is viscous and has limited compatibility. In using chlorinated paraffin (5), it is necessary to substitute the primary plasticizer with twice as much chlorinated paraffin (5) to ensure the same degree of plasticization. Chlorinated oils are less viscous and the plasticizing efficiency is better, but adversely affects gelation rates. Also bromine containing compounds such as Tetrabromo Dioctyl phthalate find use as secondary plasticizers in flame retardant PVC formulations. The primary flame retarding mechanism of these brominated compounds, involves the release of halogen (bromine) into the vapor phase to inhibit combustion. Since bromine tends to be more active in the vapor phase than the chlorine which normally evolves from PVC during combustion, improvements in flame retardance are often seen when this plasticizer is used in flexible PVC formulations. Due to its bromine content, Tetrabromo Dioctyl phthalate (11) tends to develop more smoke than other plasticizers during combustion.
[0040] Stabilizers and co-stabilizers
PVC must be stabilized, in order to be processed, against the action of heat required at processing temperatures. When PVC is processed as pure polymer, it would rapidly and completely decompose at the required temperature for molding or extrusion (150°C - 200°C). The necessary protection is provided by the addition of heat stabilizers. PVC molecule is unstable to heat and light. Heating PVC causes breakage of the polymer chains, liberating hydrochloric acid in the gaseous state. HCl catalyzes additional degradation, releasing large quantities of corrosive HCl. This autocatalytic reaction begins at 100°C, while at 180°C a marked brown color occurs after few minutes.
[0041] A majority of stabilizers contain metal elements which react with HCl and inhibit further degradation. They are metal salts, soaps or complexes. Heat stabilizers retard dehydrochlorination and auto-oxidation and reduce fragmentation by substitution of structural defeats for more stable groups in the polymer chain, scavenge the evolved hydrogen chloride and block the free radicals formed during the degradation process. The main classes of PVC stabilizers are complex mixtures of metal soaps with co- stabilizers, antioxidants, solvents, lubricants, etc. The most used mixture of metals is Ba/Zn and Ca/Zn (4). Mixed metals stabilizers can be liquid or solid.
[0042] Epoxidized soybean oil (12) is an example of co-stabilizer that very often is used in addition with Ca/Zn stabilizers (4).
[0043] Exposure to ultraviolet radiation also breaks up polymer chains, but is slower than heat degradation. PVC compounds intended for outdoor application require UV stabilizers. UV stabilizers have generally high absorption coefficients for UV radiation in the 290-315 nm range, and exert their effect at relatively low concentration levels like 0.2- 0.3 phr range.Various pigments such as activated carbon black (2) functions as UV absorber and titanium dioxide (7) as a light scatterer and opacifier.

[0044] Lubricants
Lubricants are processing additives. Lubricant actions and effects can be divided into external and internal, some lubricant can combine both functions. The external lubrication effect is the reduction of the coefficient of friction and adhesion between hot PVC composition and the surfaces of the processing machine. The basic internal lubrication effect is the lowering of the internal friction of the composition, which reduce melt viscosity. Whereas rigid PVC compositions generally require both internal and external lubricant, usually in PVC-P only external lubricant are considered, as in PVC-P the plasticizer will also provide internal lubrication.
[0045] Fillers
Certain minerals, especially some naturally occurring silicates and natural carbonates, represent some of the most widely used fillers for PVC. They are used for instance in insulating and jacket formulas for wire and cable to reduce the price of the compound and to improve electrical as well as other properties. There may be at least one inorganic substance selected from the group consisting of calcium carbonate (3), magnesium carbonate, etc. Calcium carbonate (3) can provide favourable effects on flow and processing behaviour of the PVC mass. Primarily calcium carbonate (3) type such as chalk, limestone and marble of various fineness are deployed. Their surfaces can be treated or untreated. Treated surfaces lead to a reduction of plasticizer absorption of the filler material.
[0046] Flame retardants
Referring to Figure 1, a matrix of various constituents and additives contributing to flame retardance is illustrated. Of those which are in the form of solid particulates, those of significant functional advantage are aluminum Trihydrate (6) and their mixture with zinc borate (8). They are used in low proportion, (up to about 10 parts per hundred resin) not to affect drastically the mechanical and physical properties of PVC.
[0047] Zinc Borate (8)
Another additive in the inventive PVC formulation is zinc borate (8). The grade of zinc borate (8) used has the molecular formula of 2ZnO.3B2 O3.3.5H2 O and is thermally stable up to 290° C. This grade has a surface area of 10 meter2/ gram. Surface area is an important parameter because all the constituents are absorbed on to the surface of it. Zinc species (zinc chloride or oxychlorides) can catalyse the dehydrohalogenation reaction during PVC combustion and acts as a vapour phase flame retardant. There is also promotion of cross-linking reactions causing formation of a carbonaceous char; which is a solid material that remains after light gases and tar have been driven out or released from a carbonaceous material during the initial stage of combustion. Zinc borate (8) has been recognized for its ability to suppress smoke and afterglow, which often occur during the burning of a polymer composite or wood.
[0048] Titanium dioxide (7) acts as a white coloring pigment. TiO2 (7) is also an effective opacifier in powder form, where it is employed as a pigment to provide whiteness and opacity to products such as paints, cable coatings, plastics, papers, inks, foods, medicines(i.e. pills and tablets) as well as most toothpastes. Therefore, its gives and opacifying effect on the coloring of PVC formulations. The effect is partially reduced when it is used together with borates. Titanium dioxide (7) particle size has a role in the pigmenting properties, as coarser grades are less opaque, and allow the use of lower pigment loading.
[0049] By adding a predetermined quantity of Zeolites (10), which is an aluminosilicate compound, to the cable coating, it is possible to limit the ingress of water to the inside of the cable, for a sufficiently long period. Zeolite (10) acts as a desiccant and prevents the moisture from getting absorbed into the wires and cables containing copper and other metals. Zeolite (10) does not degrade the compound as it allows the bond of the constituents to remain intact and prevents it from being broken. The amount of zeolite (10) used in the present invention is 0.1 phr or 0.1 parts.
[0050] Substantial loading (i.e. about 40 - 100 phr or even more) with metal hydrates like aluminum hydroxide or magnesium hydroxide (9) is necessary to realize the effects of these additives, so that the effect on the mechanical properties as well as on certain other properties of the PVC can be considerable.
[0051] A catalyst is added to primarily increase or accelerate the rate of a reaction. Tetra- butyl ammonium bromide (TBAB) is one such catalyst used in the present invention. TBAB, however, not only acts as a catalyst but also prevents hygroscopy i.e. the ability of a PVC formulation to attract and hold water molecules from the surrounding environment. The amount of TBAB used in the present invention is 0.2 phr or 0.2 parts.
[0052] A flame-retardant UV cable, wherein: it is composed of the following parts by weight of raw materials obtained:
PVC resin -- 150 parts per Weight of PVC Polymer Resin (1) having K value 70,
Primary Plasticizer-- 48 parts of DOP (Dioctyl phthalate) (11),
Filler-- 25 parts of calcium carbonate or CaCO3 (3) having its particle size 5 mm,
Stabilizers-- 9 parts of Ca-Zn stabiliser (4) (Repak G-NT/7526),
Co-stabilizer-- Not more than 5-7 parts of Epoxidized Soybean oil (12) (Reaflex EP/6),
Colorant, Light scatterer and opacifier-- 1 part of TiO2 (7),
Flame Retardant agents—10 parts of Zinc Borate (8), 20parts of aluminium Trihydrate (6)
Secondary FR (Flame Retardant) plasticizer 3 to 5 parts of Chlorinated paraffin (5) (Cereclor 70),
UV absorber-- 2parts of activated carbon black (2)
Metal Hydrate- 2 parts of magnesium hydroxide (9)
Catalyst – 0.2 parts of Tetra- butyl ammonium bromide (TBAB)
Desiccant - 0.1 parts of Zeolite (10)
[0053] Initially PVC Resin (1) at 40 ~ 50 ? is masticated i.e. grinded in a mixer for5 to 6 minutes. Subsequently adding semi-reinforcing activated carbon black (2), calcium carbonate (3), Ca-Zn stabilizer (4), Chlorinated paraffin (5), and then subsequently adding aluminium trihydrate (6), TiO2 (7), Zinc Borate (8), Magnesium hydroxide (9), Zeolite (10), Di Octyl Phthalate (11), epoxidized soya bean oil (12), Tetra- butyl ammonium bromide. All the above constituents are thereafter kneaded for 25 to 30 minutes into a dough or pulp form, maintaining the temperature in the mixer to 90 ~ 100 ?. The optimum time required for kneading the mixture is 30 minutes. This mixture is intimately mixed in a mixer at the application of the total composition to an object, such as surface of concrete or metal.
[0054] The resultant flame retardant UV cable obtained has following parameter observed:
Density 1.365 gm. /cm3

Thermal conductivity 255 W/ (m °K)
Tensile strength 16.72 N/mm2
Elongation 275%
Hardness 88 HV
Oxygen Index 30

[0055] UV radiation Test exposed at BIS/NABL ACCRETATED LABORATORY as Per ASTM G154-00a.
[0056] There is no sign of cracks or scales as well as no colour change in the resultant Flame retardant UV cable formed when exposed to sunlight for considerable period of several weeks
[0057]While the invention has been described with reference to specific preferred embodiments, the invention is certainly not limited to those precise embodiments. Rather, many modifications and variations will become apparent to persons of skill in the art without departure from the scope and spirit of this invention, as defined in the appended claims.

Claims:We Claim,
1. A formulation for flame retardance and UV resistance for wires and cables, the formulation being free of antimony based compounds, comprising:
a) 150 parts of a PVC resin;
b) 5 to 50 parts of at least one plasticizer;
c) 7 to 30 parts of at least one flame retardant compound;
d) 5 to 16 parts of a plurality of stabilizers;
e) 2 to 5 parts of a metal hydrate;
f) 2 to 5 parts of an activated carbon black;
g) 0.2 to 0.5 parts of a Tetra-butyl ammonium bromide and
h) 0.1 to 0.2 parts of a Zeolite
in addition to additives, like lubricants, fillers, colorants wherein the PVC resin and at least one plasticizer includes at least one phthalate plasticizer and wherein, the phthalate plasticizer and the flame retardant compound are present in a total amount effective to render the composition capable of passing the flame-resistant requirements of wires and cables that are free of antimony compounds.

2. A formulation for flame retardance and UV resistance for wires and cables, the formulation being free of antimony based compounds, comprising:
a) 150 parts of a PVC resin;
b) 5 to 50 parts of at least one plasticizer;
c) 7 to 30 parts of at least one flame retardant compound;
d) 5 to 16 parts of a plurality of stabilizers;
e) 2 to 5 parts of a metal hydrate;
f) 2 to 5 parts of an activated carbon black;
g) 0.2 to 0.5 parts of a Tetra-butyl ammonium bromide and
in addition to additives, like lubricants, fillers, colorants wherein the PVC resin and at least one plasticizer includes at least one phthalate plasticizer and wherein, the phthalate plasticizer and the flame retardant compound are present in a total amount effective to render the composition capable of passing the flame-resistant requirements of wires and cables that are free of antimony compounds.

3. The formulation for flame retardance and UV resistance for wires and cables as claimed in claim 1 or 2, characterized in that it further comprises at least one of the following additional components: primary plasticizer, secondary plasticizer, and secondary flame retardant plasticizer.
4. The formulation for flame retardance and UV resistance for wires and cables as claimed in claim 1 or 2, characterized in that it comprises primary FR (Flame Retardant) plasticizers.
5. The formulation for flame retardance and UV resistance for wires and cables as claimed in claim 1 or 2, wherein the formulation additionally comprising flame retardant compound selected from the group consisting of aluminum trihydrate, zinc borate and barium sulfate.
6. The formulation for flame retardance and UV resistance for wires and cables as claimed in claim 1 or 2, characterized in that said primary plasticizer is selected among phthalate plasticizers like Di Octyl Phthalates (DOP), Di isononyl phthalate (DINP), Tri Octyl trimellitate (TOTM), and Di isodecyl phthalate (DIDP), Di isotridecyl phthalate (DITP).
7. The formulation for flame retardance and UV resistance for wires and cables as claimed in claim 1 or 2, additionally comprising chlorinated paraffin or chlorinated oils as secondary plasticizers.
8. The formulation for flame retardance and UV resistance for wires and cables as claimed in claim 1 or 2, additionally comprising a coloring pigment, a light scatterer, an opacifier such as titanium dioxide.
9. The formulation for flame retardance and UV resistance for wires and cables as claimed in claim 1 or 2, wherein metal hydrates is selected from aluminium hydroxide or magnesium hydroxide
10. The formulation for flame retardance and UV resistance for wires and cables as claimed in claim 1 or 2, wherein stabilizers is selected from mixture of metals such as Ba/Zn and Ca/Zn and the co-stabilizer used is epoxidized soya bean oil.
11. The formulation for flame retardance and UV resistance for wires and cables as claimed in claim 1 or 2, wherein fillers may be selected from group of inorganic substance consisting of calcium carbonate and magnesium carbonate.
12. A method for making formulation for flame retardance and UV resistance for wires and cables, the method comprising the steps of:
masticating PVC resin at 40 ~ 50 ? in a mixer for 5 to 6 minutes;
subsequently adding semi-reinforcing activated carbon black, tetra-butyl ammonium bromide, calcium carbonate, Ca-Zn stabilizer, Chlorinated paraffin, then adding aluminium Trihydrate, TiO2, Zinc Borate, magnesium hydroxide, Zeolite, Di Octyl Phthalate, epoxidized soya bean oil;
kneading all the above constituents for 25 to 30 minutes into a dough or pulp form;
maintaining the temperature in the mixer to 90 ~ 100 ?; and
intimately mixing a mixture at the application of the total composition to an object, such as surface of concrete or metal.
13. The method for making formulation for flame retardance and UV resistance for wires and cables as claimed in claim 12, kneading the constituents of the mixture for 30 minutes which is the optimum time required.