Title of Invention

"ELECTRICALLY INSULATING, FLAME RETARDANT TAPE AND THE PROCESS OF MANUFACTURING THE SAME"

Abstract

"Electrically Insulating, Flame retardant Tape", which does not stretch during application and is suitable for splicing electrical joints for low voltage applications, especially in humid conditions, comprises of the steps (a) preparation of formulated plastisol compound by suspension of PVC in a plasticizer, having flame retardant and electrical insulation properties; (b) preparation of formulated pressure sensitive adhesive having flame retardant and electrical insulation properties; (c) coating the said formulated plastisol compound on one side of synthetic fabric by knife coating or calendaring technique; (d) coating the said formulated pressure sensitive adhesive on the other side of the said plastisol compound coated fabric by conventional coating method and thereafter diying by passing through air dryers to get the electrically insulating, flame retardant tape; (e) cutting the said electrically insulating, flame retardant tape in desired length and width.

Full Text

FORM 2 THE PATENTS ACT, 1970 (39 of 1970) COMPLETE SPECIFICATION (See Section 10) "ELECTRICALLY INSULATING, FLAME RETARDANT TAPE AND THE PROCESS OF MANUFACTURING THE SAME" PRS Solutions Private Limited, a Company incorporated under the Companies Act, 1956 and having its office at 63, Bombay Samachar Marg, Mumbai - 400 001 Maharashtra State, India. The following Specification particularly describes and ascertain the nature of this invention and the manner in which it is to be performed. FIELD OF THE INVENTION: The present invention relates to "electrically insulating, flame retardant tape and the process of manufacturing the same". It is an electrical insulation adhesive tape comprising of a synthetic fabric having a polymeric flame retardant material on one side and a flame retardant pressure sensitive adhesive on the other side. The said tape, which is electrically insulating and flame retardant, does not stretch during application and is suitable for splicing electrical joints such as wires for low voltage applications, especially in humid conditions. DESCRIPTION OF THE PRIOR ART: Most electrical fires result from defects in, or misuse of, the power delivery system. Overloaded extension cords, the use of unsuitable insulation material for electrical joints such as masking or cellophane tape, damaged plugs, a build-up of dust and dirt in the electrical system, exposure to moisture, heat and chemicals all pose as fire hazards. In the electrical industry polyvinyl chloride (PVC) film based pressure sensitive adhesive tapes are widely used for providing insulation on the joints. While such tapes provide the desired flame retardancy and self extinguishing properties they can withstand temperatures only upto 80°C and may melt due to high heat generated by strong sparks in a joint. Further PVC tapes suffer from the disadvantages of being stretched during application and have tendency to melt and drip when in contact with fire. Stretching during application leads to stress being imparted to the joint where the tape is applied resulting in the tape unfurling later at the ends. Melting and dripping of the tape can lead to propagation of fire to the flammable materials in the vicinity. Other available pressure sensitive adhesive tapes for electrical insulation are based on backing materials such as cotton cloth, film or paper etc. Cotton cloth and paper based tapes absorb moisture and are not suitable for use under high humid conditions. Hence, there was a need to overcome these shortcomings by developing a tape, which does not stretch during application, does not absorb moisture, extinguishes flames and sparks without melting or dripping. The objective of the present invention is to provide an electrical tape which is designed to work at low voltage applications such as insulating joints in a cable or wire and which does not stretch during application, does not absorb moisture, extinguishes flame and sparks without melting or dripping thereby preventing propagation of flame in case of fire and which is suitable for splicing electrical joints for low voltage applications, especially in humid conditions. SUMMARY OF THE INVENTION The present invention relates to "Electrically insulating, flame retardant tape" which is flame retardant, electrically insulating, and is suitable for application in humid conditions. The process of manufacturing the said electrically insulating, flame retardant tape comprises of preparing the formulated plastisol compound by suspension of PVC in a plasticizer, having flame retardant properties and coating the same on one side of synthetic fabric followed by preparing formulated pressure sensitive adhesive having flame retardant properties and coating on the other side of the said plastisol compound coated fabric to get the electrically insulating, flame retardant tape. THE INVENTION This invention provides an insulation tape comprising of a synthetic fabric having a polymeric flame retardant material on one side and a flame retardant pressure sensitive adhesive on the other side which can be applied to insulate low tension joints without stretch thereby giving a firm splice on the joint. The said flame retardant low tension electrical insulation tape has high adhesion to metal as well as self-adhesion, the most important feature of this tape is that it is flame-retardant and will self- extinguish in case of sparks and will not propagate the flame to the vicinity as it does not melt or drip due to high heat generated by a strong spark. It has excellent resistance to moisture, alkalis and acids thereby making it a perfect insulation in humid and/or industrial atmosphere as well as for domestic applications. When PVC polymer particles are mixed at room temperature with sufficient plasticisers and all voids are filled, the PVC particles will become suspended in the plasticiser and a paste called "plastisol" will be formed. The plastisols are converted into tough rubbery products by heating at about 160°C. The present invention also describes the process of manufacturing the said electrically insulating flame retardant tape which comprises of:- (a) preparation of formulated plastisol compound consisting of at least one polymeric resin which has flame retardant and electrical insulation properties and plasticizers, stabilizers and pigments.; (b) preparation of formulated pressure sensitive adhesive having flame retardant and electrical insulation properties and consisting of at least one flame retardant ingredient; (c) coating the said formulated plastisol compound on one side of synthetic fabric thereby providing a layer of thickness preferably ranging between 0.05 mm to 0.15 mm by knife coating or calendaring technique; (d) coating the said formulated pressure sensitive adhesive on the other side of the said plastisol compound coated fabric thereby depositing a layer of adhesive having thickness preferrably ranging between 0.08mm to 0.15 mm by conventional coating method and thereafter drying by passing through air dryers to get the electrically insulating, flame retardant tape; (e) cutting the said electrically insulating, flame retardant tape in desired length and width. The backing material in this invention is a woven fabric comprising of polyester yarn in both warp and weft directions and having thickness preferrably in the range of 0.13 mm to 0.14 mm, however any other thickness can also be used. The plastisol compound is manufactured by blending materials comprising of synthetic polymers such as polyvinyl chloride preferrably 40% to 60%, plasticizers such as , tricresyl phosphate preferrably 30% to 40%, fillers like oxides and/or hydroxides of metal, naturally occurring minerals preferrably 10% to 20%,, stabilisers and pigments, (preferrably 1% to 2%), to form a compound of coatable consistency and texture commensurate to the coating technique. The pressure sensitive adhesive is manufactured by blending materials comprising elastomeric material eg. natural and/or synthetic rubbers, tackifying resins like hydrocarbon or polyterpene resins, fillers like oxides and/or hydroxides of metals, naturally occurring minerals, halogenated organic compounds, and followed by solvating with hydrocarbon/aromatic solvents to form a compound of coatable consistency and texture commensurate to the coating equipment. The elastomeric component which forms 30% to 50% of the pressure sensitive adhesive comprises of two parts (I) natural rubber like Rubber Manufacturers Association (RMA) Grade-I, RMA Grade-II, RMA Grade-Ill, RMA Grade-IV, Pale Crepe of various grades and (ii) synthetic rubber like Styrene Butadiene Rubber, Fluro elastomer, Polychloroprene. The said tackifying resins used in the said adhesive is in the range of 10 % to 50% preferrably between 15 % to 20% which can be formed of hydrocarbon resins, rosin and rosin derivatives, polyterpenes, coumarone-indene resins, any compatible conventional tackifier or mixtures thereof. The resins can be modified with alpha methyl styrene. It has been found that a mixture of resins does provide a better balance of properties than any one resin alone. The said fillers used in the said adhesive can be in the range of 15%-50% preferrably between 20%-30% and is formed of calcium carbonate, barytes, aluminium trihydroxide, zinc oxide, clay, antimony oxide and mixtures thereof in order to extend the adhesive and alter its appearance. For preparation of the said adhesive small amounts of other modifiers such antioxidants, heat stabilizers and pigments are added. Antioxidants and heat stabilizers are to be used for improved heat stability of the adhesive. Typical antioxidants are 2, 5, ditertiaiy amyl hydroquinone, di-tertiary butyl cresol and amines. Conventional heat stabilizers such as Zinc salts of alkyl dithiocarbomates are used in the present invention. Ultraviolet absorbers are added to the adhesive when improved outdoor weathering is required. Coloured pigments in the range of 2% to 10% is added to obtain a colored adhesive. The electrically insulating, flame retardant tape obtained by the above mentioned process is suitable for use as electrical insulation tape mainly over joints of electrical cables/wires and is: 1. Highly flexible and conformable but non stretchable 2. Having very high adhesion to metal and self 3. Easy to unwind from the roll 4. Self extinguishing 5. Flame retardant meeting various test methods such as IS 7809, ASTM D 1000, and UL 510 6. Not affected by flame and does not melt or drip when exposed to spark and/or flame 7. Having good electrical strength both in dry as well as in humid conditions Description of the Drawing in Figure 1 of 1 : 1. Flame retardant Plastisol coating 2. Fabric 3. Flame retardant Adhesive WE CLAIM :- 1. "Electrically Insulating, Flame retardant Tape, that does not stretch during application and is suitable for splicing electrical joints for low voltage applications, especially in humid conditions, comprising of a synthetic fabric having a polymeric flame retardant material on one side and a formulated pressure sensitive adhesive on the other side. 2. "Electrically Insulating, Flame retardant Tape as claimed in Claim 1, wherein the said synthetic fabric is a woven fabric comprising of polyester yarn in both warp and weft directions and having thickness preferably in the range of 0.13 mm to 0.14 mm however any other thickness he also used. 3. A process of manufacturing electrically insulating, flame retardant tape comprises of the following steps:- (a) preparation of formulated plastisol compound consisting of at least one polymeric resin that has flame retardant and electrical insulation properties and plasticizers, stabilizers and pigment; (b) preparation of formulated pressure sensitive adhesive having flame retardant and electrical insulation properties and consisting of at least one flame retardant ingredient; (c) coating the said formulated plastisol compound on one side of synthetic fabric thereby providing a layer of thickness preferably ranging between 0.05 mm to 0.15 mm by knife coating or calendaring technique; (d) coating the said formulated pressure sensitive adhesive on the other side of the said plastisol compound coated fabric depositing a layer of adhesive having thickness preferably ranging between 0.08mm to 0.15 mm by conventional coating methoand thereafter drying by passing through air dryers to get the Electrically Insulating, Flame Retardant Tape; (e) the said Electrically Insulating, Flame Retardant Tape is cut in desired length and width. 4. A process as claimed in Claim 3 wherein, the said synthetic polymer is polyvinyl chloride resin. 5. A process as claimed in Claim 3, wherein the said formulated plastisol compound is made by blending of synthetic polymer (40% to 60%), plasticizers preferably 30% to 40%, fillers (10% to 20%) and/or hydroxides of metal, naturally occurring minerals, stabilisers and pigments. 6. A process as claimed in Claim 3 and 5 wherein, the said plasticizer is tricresyl phosphate. 7. A process as claimed in Claim 5 wherein, the said fillers are oxides. 8. A process as claimed in Claim 3, wherein the said formulated pressure sensitive adhesive is manufactured by blending elastomeric components, fillers like oxides and/or hydroxides of metal, naturally occurring minerals, halogenated organic compounds preferrably (20-25%), tackifying resins of natural/synthetic type followed by solvating with hydro carbon/aromatic solvents to form a compound of coatable consistency and texture commensurate to the coating equipment. 9. A process as claimed in Claim 8, wherein the said elastomeric component forms 30% to 50% of the pressure sensitive adhesive which comprises of two parts (I) natural rubber like Rubber Manufacturers Association (RMA) Grade-I, RMA Grade-II, RMA Grade-Ill, RMA Grade-IV, Pale Crepe of various grades and (ii) synthetic rubber like Styrene Butadiene Rubber, Fluro elastomer, Polychlor oprene. 10. A process as claimed in Claim 8, wherein the said tackifying resins used in the said adhesive is in the range of 10 to 50% preferrably between 15 to 20% and is formed of hydrocarbon resins, rosin and rosin derivatives, polyterpenes, coumarone-indene resins, any compatible conventional tackifier or mixtures thereof. 11. A process as claimed in Claim 8 wherein the said fillers used in the said adhesive is in the range of 15 to 50% preferrably between 20-30% and is formed of calcium carbonate, barytes, aluminium trihydroxide, zinc oxide, clay, antimony oxide and mixtures thereof in order to extend the adhesive and alter its appearance.

Documents:

487-mum-2010-abstract.doc

487-mum-2010-abstract.pdf

487-MUM-2010-CLAIMS(AMENDED)-(18-10-2013).pdf

487-MUM-2010-CLAIMS(AMENDED)-(3-7-2014).pdf

487-mum-2010-claims.doc

487-mum-2010-claims.pdf

487-MUM-2010-CORRESPONDENCE(13-6-2014).pdf

487-MUM-2010-CORRESPONDENCE(29-7-2010).pdf

487-MUM-2010-CORRESPONDENCE(5-3-2010).pdf

487-MUM-2010-CORRESPONDENCE(IPO)-(13-10-2010).pdf

487-mum-2010-correspondence.pdf

487-mum-2010-description(complete).pdf

487-mum-2010-drawing.pdf

487-mum-2010-form 1.pdf

487-MUM-2010-FORM 18(29-7-2010).pdf

487-mum-2010-form 2(title page).pdf

487-mum-2010-form 2.doc

487-mum-2010-form 2.pdf

487-mum-2010-form 26.pdf

487-mum-2010-form 3.pdf

487-mum-2010-form 5.pdf

487-MUM-2010-FORM 9(5-3-2010).pdf

487-MUM-2010-ORIGINAL CLAIMS(3-7-2014).pdf

487-MUM-2010-OTHER DOCUMENT(18-10-2013).pdf

487-MUM-2010-REPLY TO EXAMINATION REPORT(18-10-2013).pdf

487-MUM-2010-REPLY TO HEARING(3-7-2014).pdf

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