Title of Invention

A BIODEGRADABLE INSULATING FLUID COMPOSITION

Abstract

A composition for biodegradable insulating fluid that mainly contains non-edible vegetable oil or its monoesters. The mono ester is ester of fatty acid or epoxy fatty acid or mono ring aryl substituted fatty acid from the non-edible triglyceride and higher mono alcohol or mixture thereof. In addition to non-edible vegetable oil or its monoesters, the composition also contains an antioxidant, an antifoaming agent, a pour point depressant, a corrosion inhibitor and a detergent-dispersant additive. The product is from renewable source, produce less toxic waste & pollution due to leakage and spillage, reduces fire hazards, safe to use, able to replace the mineral lube oil and has utility as an insulating fluid in electrical installations such as transformer. The main advantages are, it reduces use of petroleum, cheaper than synthetic oil, product is significantly biodegradable and eco-freindly, and safe to use due to higher flash point.

Full Text

FIELD OF THE INVENTION The present invention relates to a biodegradable insulating fluid composition. This invention particularly relates to biodegradable insulating fluid composition that mainly contains non-edible vegetable oil monoesters. In addition to monoesters, the composition also contains an antioxidant, an antifoaming agent, a pour point depressant, a corrosion inhibitor and a detergent-dispersant additive. The product of this invention is significantly biodegradable from renewable source and has utility as an insulating fluid in electrical installations such as transformer. BACKGROUND AND PRIOR ART OF THE INVENTION Enhancing the life of an electrical transformer is an essential part of a modern power operation technology. The aging or deterioration of insulating oil is normally associated with oxidation. Due to the presence of oxygen and water, insulating oil oxidizes even under ideal conditions. The insulating properties of the oil are also affected by contaminants from the solid materials in the transformer dissolving in the oil. The reaction between unstable hydrocarbons in the oil and oxygen, moisture or other chemicals in the atmosphere, with the assistance of accelerators such as heat, results in decay products in the oil. Mineral oil insulating fluids undergo oxidative degradation in the presence of oxygen to give a number of oxidation products. The final products of oxidation are acidic materials that can affect the characteristics of the insulating fluid as well as damage the components of the electrical unit. The high temperatures in due course cause the fluid to oxidize and ultimately produce sludge and soluble acid in sufficient quantity to impair its heat transfer and dielectric efficiency. Sludge formation is the terminal stage of the deterioration process. The acids formed in the process of oxidation attack on the cellulose fibers and metals forming metallic soaps, lacquers, aldehydes, alcohols and ketones which precipitate as heavy tarry acidic sludge on the insulation. Sludge appears faster in heavily loaded, hot running and abused transformers causing shrinkage of the insulation through leaching out varnishes and cellulose materials. The main purpose of transformer oil is to insulate and cool the transformer. A specification is a good start, but to successfully find just the right oil for transformer, details are needed. All transformers and their requirements are different. And right oils are needed that are tailored for each transformer's need for availability, performance and its geographical conditions. The Naphthenic oils are the best, which have outstanding properties for use in a transformer. Much due to their low viscosity at high temperatures and excellent solvency at very low temperatures. They also have high oxidation stability and great electrical properties that make them the perfect choice for a transformer. Now, pollution and environmental aspects of various products have become important issues. The uncontrolled loss of lubricants can endanger environment by coming into contact directly with the nature (organisms, soil, live water etc.) as a consequence of leakage, throw off, emissions, spillage or careless disposal. Great efforts have been made during the last 25 years by several countries and major industries to develop and find more and more environment friendly products and technologies which have a less negative impact on our precious environment. Reference may be made to US Patent 6,726,857 and US Patent 6,485,659 Goedde , et al. April 27, 2004 Cooper Industries, Inc. (Houston, TX) Dielectric fluid having defined chemical composition for use in electrical apparatus. The dielectric coolants for use in sealed, non-vented transformers, and have improved performance characteristics, including decreased degradation of the paper insulating layers, as well as a greater degree of safety and environmental acceptability. This consist of aromatic hydrocarbons (di or tri aryl ethane such as biphenyl ethane or ethyl naphthalene), polyalphaolefins, polyol esters, and natural vegetable oils, along with additives to improve pour point, increase stability and reduce oxidation rate.(blend of mineral oil, polyalphaolefins, polyol esters and natural vegetable oils was used ) Reference may be made to US Patent 6,645,404 Oommen , et al. November 11, 2003 ABB Technology AG (Zurich, CH) High oleic acid oil compositions and methods of making and electrical insulation fluids and devices comprising the same. High oleic acid triglyceride having the properties of a dielectric strength of at least 35 KV/100 mil gap, a dissipation factor of less than 0.05% at 25 NC., acidity of less than 0.03 mg KOH/g, electrical conductivity of less than 1 pS/m at 25 NC., a flash point of at least 250 NC. and a pour point of at least -15 NC with additives are disclosed as electrical insulation fluids, .(natural vegetable oils, sunflower oil, was used ) Reference may be made to US Patent 6,340,658 Cannon , et al. January 22, 2002 Wavely Light and Power (Waverly, IA) Vegetable-based transformer oil and transmission line fluid. A vegetable oil-based electrically-insulating fluid is environmentally-friendly and has a high flash point and a high fire point. The base oil is hydrogenated to produce maximum possible stability of the oil, or alternatively, is a higher oleic acid oil. The vegetable oils of the preferred embodiments are soybean or corn oils. The oil can be winterized to remove crystallized fats and improve the pour point of the base oil, without the necessity of heating the oil. The base oil can also be combined with an additive package containing materials specifically designed for improved pour point, improved cooling properties, and improved dielectric stability. The fluid is useful in electrical components such as transformers and transmission lines. It also provides methods for making the fluid and fluid-filled electrical components, (natural vegetable, soybean or corn oils were used ) In 'the prior art for producing Insulating fluids, generally, mineral oils or mineral oil with synthetic fluids or complex ester of fatty acids were used. The focus has been on the use of such oil base to enhance the performance. In view .of the growing concern about the environment, there is a need for developing new significantly biodegradable insulating fluid composition from renewable source such as vegetable oil mono-esters. These objectives must be met, while simultaneously satisfying stringent performance standards of insulating fluids. Vegetable oil that is long chain fatty acid tri-ester of glycerol possesses most of the desirable lubricant properties such as high viscosity index, high flash point, low volatility and good boundary lubrication. As per fatty acid typical composition of vegetable oils, it contains unsaturated acids such as oleic C18:1 as a major component. It is understood that some of the carbon chain lengths of the carboxylic acids and/or esters disclosed herein are average numbers. This reflects the fact that some of the carboxylic acids and/or esters are derived from naturally occurring materials and therefore contain a mixture of compounds the major component of which is the stated compound. Non-edible vegetable oil, which are found in abundance in India are (1) Neem - Mellia Azadirachta in the family Meliaceae, (2) Karanja - Pongamia glabra in the family Leguminaceae, (3) Ricebran - Oryza sativa in the family Graminaceae, (4) Mahua- Madhuca Indica & Madhuca Longifolia, (5) Castor - Ricinus communis in the family Euphorbiaceae (spurge), (6) Linseed - Flax oil plant Linium usitatissimum ( Linacae), (7) Other similar vegetable oil or their mixture. Vegetable oils are completely biodegradable. Thermo-oxidative, cold behavior and flow properties of vegetable oil can be enhanced by converting it into epoxy, aryl or simple mono ester of its fatty acid and a suitable higher alcohol. The vegetable oil or its mono ester can be used as an alternate to mineral base stock of lubricants. It will reduce the hazard potential of the lubricants. It will provide required properties such as good insulating, dissipation of heat, stability, anti-corrosion properties and more eco-friendliness. OBJECTIVES OF THE INVENTION The main object of the present invention is to provide a composition for insulating fluid from renewable source and based on mono-ester from non-edible vegetable oil found in India. Another object of the present invention is not to use mineral oil and reducing pollution potential of the insulating fluid formulation. Yet another object of the present invention is to provide insulating fluid compositions and its base stocks for both as transformer liquid and oil-paper insulation. Yet another object of the present invention is to provide excellent miscibility of formulated insulating fluid with mineral and synthetic oil in all proportions. SUMMARY OF THE INVENTION Accordingly the present invention provides an insulating fluid composition comprising: i. mono-esters of non-edible vegetable oils fatty acid in the range of ii. anti-oxidant in the range of iii. detergent -dispersant in the range of iv. anti-foaming agent in the range of v. pour point depressant in the range of vi. corrosion inhibitor in the range of 97.70-99.894 wt%, 0.006-0.05% by weight, 0.05-0.15% by weight, 0.01 to 1.0% by weight, 0.01 to 1.0% by weight, 0.03-0.1% by weight. In an embodiment of the present invention the insulating fluid composition further comprising: i. mono-esters of non-edible vegetable oils fatty acid selected from the group consisting of butyl-9-octadecenoic ester of formula-[C8Hi7CH=CHC7Hi4COOC4H9], ethyl-(10-epoxy)-9-octadecenoic ester, of formula [C8Hi7(>O)CH=CHC7H14COOC2H5], 2-propyl-(10-tolune)-9-octadecenoic ester of formula [CsH-CehUChChCHCTHu COO C3H7 ] and a mixture thereof in the range of: 97.70-99.894 wt%, ii. anti-oxidant in the range of 0.006-0.05% by weight, 0.01 to 1.0% by weight, 0.01 to 1.0% by weight, 0.03-0.1% by weight. iii. detergent -dispersant in the range of 0.05-0.15 % by weight, iv. anti-foaming agent in the range of v. pour point depressant in the range of vi. corrosion inhibitor in the range of In an embodiment of the present invention, the monoester of non-edible vegetable oil fatty acid used is a monoester of fatty acid with C1 to C16 preferably C7 to C8 primary alcohol. In another embodiment of the present invention, the mono-ester of vegetable oil fatty acid used is selected from the group consisting of simple ester, partially hydrogenated ester, epoxy ester, aryl alkyl ester of fatty acids and a mixture thereof. In still another embodiment of the present invention, the non-edible vegetable oil triglyceride fatty acid used for making ester is selected from the group consisting of C18:1, C18:2, C18:3, having the mono-unsaturation character in the range of about 50 to 70 weight percent. In yet another embodiment of the present invention, the non-edible vegetable oil used is selected from the group consisting of karanja (Pongamia glabra) oil, neem (Mellia azadirachta) oil, ricebran (Oryza sativa) oil, mahua (Madhuca indica) oil, castor (Ricinus communis) oil, acetylated castor, linseed (flax-Linium usitatissimum) oil, other vegetable oils and a mixture thereof. In yet another embodiment of the present invention, the non-edible vegetable oil used is preferably selected from the group consisting of karanja, ricebran, mahua, neem and a mixture thereof. In yet another embodiment of the present invention, the mono-esters of fatty acids used as base stock have viscosity, cst, of at most 27 at about 27°C and a flash point of at least 150°C (Cleveland Open Cup). In yet another embodiment of the present invention, the anti-oxidant is selected from the group consisting of hindered phenol, alkyl amine, amino phenol and tetrazole, preferably 4-methyl-2,6-di-(t-butyl) phenol, or Methyl hydroxy hydro cinnamide or N-tetra propylene 5-amino tetrazole or 5-amino tetrazole 2,6,di-tert. butyl phenol. In yet another embodiment of the present invention, the detergent-dispersant is selected from the group consisting of calcium alkyl benzene sulfonate, sodium alkyl benzene sulfonate, propylene teramer succinimide of pentaethylene hexamine, octyl phosphonates, etc. preferably succinimide or sulfonate.- In yet another embodiment of the present invention, the anti-foaming agent is selected from the group consisting of silicone oil, polyvinyl alcohol, polyethers, etc. preferably silicone oil or polyvinyl alcohol. In yet another embodiment of the present invention, the anti-foaming agent is selected from the group consisting of silicone oil, polyvinyl alcohol. In yet another embodiment of the present invention, the pour point depressants is selected from the group consisting of diethylhexyl adipate, polymethacrylate and polyvinylacrylate. In yet another embodiment of the present invention, the rust or anti-corrosion additive is selected from the group consisting of octyl 1H benzotriazole, ditertiary butylated 1 H-Benzotriazole, propyl gallate, polyoxyalkylene polyols, octadecyl amines, nonyl phenol ethoxylates, calcium phenolates of hydrogenated pentadecyl phenol, magnesium alkyl benzene sulfonates. In yet another embodiment of the present invention, the rust or anti-corrosion additive is selected from the group consisting of ditertiary butylated 1H-Benzotriazole, magnesium alkyl benzene sulfonates, and octadecyl amines. In yet another embodiment of the present invention, the non-edible vegetable oil compositions exhibit excellent miscibility with mineral and synthetic oil in all proportions and is useful in both liquid insulation and oil-paper insulation. In still another embodiment the biodegradable insulating fluid composition obtained having the following characteristics: i. kinetic viscosity at 27°C is in the range of 5-27 cst, ii. viscosity index is between 160-300, iii. oxidation stability is Pass (IP 48/97) iv. rotatory bomb oxidation test (ROBOT) at 95°C is between 80-190 min., v. flash point is between 170-260°C, vi. pour point is between (-)15 - (-)25°C, vii. ash sulfated % is viii. copper Strip corrosion test 1A, ix. foam test ASTM D892 Pass, x. inlerfacial tension against water is between 40-60 N/m, xi. reactive sulfur- NIL, xii. electrical strength is between 30-50KV, xiii. dissipation factor is between 0.002 - 0.2 xiv: specific Resistance (ohm"cm ) at 90°C is between 34-38 xv. density at 20°C is between 0.880-0.884. xvi. biodegradability is between 90-100%. DETAILED DESCRIPTION OF THE INVENTION The compositions are significantly biodegradable in the range of 90 to 99 %, Kinetic viscosity at 27°C is in the range of 5-27 cst, Viscosity index is between 160-300, Rotatory bomb oxidation test (ROBOT) at 95°C is between 80-190 min., Flash point is between 170-260°C, Pour point is between (-)15 - (-)25°C, Copper Strip corrosion test 1A, Interfacial tension against water is between 40-60 N/m, Reactive sulfur- NIL, Electrical strength is between 30-50KV, Dissipation factor is between 0.002 - 0.2, Specific Resistance (ohm"cm ) at 90°C is between 34-38, Density at 20°C is between 0.880-0.884, exhibit excellent miscibility with mineral and synthetic oil in all proportions and can be used in both liquid insulation and oil-paper insulation. The main advantages are, it reduces use of petroleum, safe to use due to higher flash point, non-toxic, eco-friendly, made from renewable source and beneficial to the farmers. The temperature used for blending all the components to make the homogenous composition at the moderate temperature of 60°C at which no chemical reaction occur, but all constituents get blended to obtain the desired composition having the synergistic effect reflecting a different characteristics as the individual constituents as described in the examples. The present invention provides an insulating fluid which is superior in performance, particularly in biodegradability and cost, as compared below, Comparison of properties of insulating fluids The following examples are given by way of illustration and therefore should not be constructed to limit the scope of the invention. EXAMPLE 1 MONO-ESTER PURIFICATION - Simple mono-ester of fatty acid from Neem oil, and primary alcohols iso-butanol [major portion is of butyl,9,octadecenoic ester, formula- CsHirCCHCyHCOOCg], purified by the known methods of chilling in light solvent such as hexane at 10 to 15°C for 10 to 20 hrs, decanted or cold • filtered and clay treated. Solvent was recovered to get acid free and thin oil. EXAMPLE 2 EPOXY MONO-ESTER PURIFICATION - Simple epoxy mono-ester of fatty acid from Rice bran oils and primary alcohols such as ethanol [major portion is of ethyl, (10-epoxy) 9,octadecenoic ester, formula- C8Hi7(0)CH=CHC7H14COOC2H5], purified by the known methods of chilling in light solvent such as hexane at 10 to 15°C for 10 to 20 hrs, decanted or cold filtered and clay treated. Solvent was recovered to get acid free and thin oil. EXAMPLE 3 ALKYLATED MONO-ESTER PURIFICATION - Simple toluene substituted (alkyl) mono-ester of fatty acid from Karanja oils and primary alcohol propanol [major portion is of 2 propyl,(10-tolune) 9,octadecenoic ester, formula- C8H17(-CeHUCHsJChbCHCyHu COO C3H7 ] purified by the known methods of chilling in light solvent such as hexane at 10 to 15°C for 10 to 20 hrs, decanted or cold filtered and clay treated. Solvent was recovered to get acid free and thin oil. EXAMPLE 4 PREPARATION OF BASE STOCK (A): The esters were blended to match the viscosity and stability as per requirement. 80 % (w/w) of purified simple mono-ester of neem oil & isobutanol mixed with 20 % (w/w) of the purified epoxy mono ester specially from ricebran oil fatty acid & ethanol. Blending was done by known methods. The typical kinetic viscosity of the base oil at 40°C was 4.2 cst. EXAMPLE 5 PREPARATION OF BASE STOCK (B): The esters were blended to match the viscosity and stability as per requirement. 80 % (w/w) of purified simple mono-ester of neem oil & isobutanol mixed with 20 % (w/w) of the purified alkylated (Tolune substituted) mono ester specially from Karanja oil fatty acid & propanol. Blending was done by known methods. The typical kinetic viscosity of the base oil at 40°C was 5.5 cst. EXAMPLE 6 PREPARATION OF BASE STOCK (C): 70 % (w/w) of purified simple mono-ester of neem oil & isobutanol mixed with 15 % (w/w) of the purified epoxy mono ester specially from ricebran oil fatty acid & ethanol and 15 % (w/w) of the purified alkylated (Tolune substituted) mono ester specially from karanja oil fatty acid & propanol. Blending was done by known methods. The typical kinetic viscosity of the base oil at 40°C was 6.6 cst. EXAMPLE 7 PREPARATION OF BASE STOCK (D): 90 % (w/w) of purified simple mono-ester of neem oil & isobutanol mixed with 10 % (w/w) of the purified liquid paraffin having distillation range 180 - 200°C. Blending was done by known methods. The typical kinetic viscosity of the base oil at 40°C was 4 cst. EXAMPLE 8 PREPARATION OF BASE STOCK (E): 100 % (w/w) of purified epoxy simple mono-ester specially from ricebran oil fatty acid & ethanol. The typical kinetic viscosity of the base oil at 40°C was 6.1 cst. EXAMPLE 9 PREPARATION OF INSULATING FLUID : The base stock (A) in 99.845 % (w/w) was blended with additives Methyl Hydroxy Hydro Cinnamate in 0.025 % (w/w) concentration, silicone oil in 0.01 % (w/w) concentration, Propylene tetramer succinimide of pentaethylene hexamine in 0.05 % (w/w), polyacrylate in 0.02 % (w/w), and Calcium HAB sulfonate having base number 500 in 0.05 % (w/w) concentration. The doping was done at 60°C with stirring for 2 hours. The fluid has viscosity, cst at 27°C was 8.2, viscosity index was 165, flash point 192°C, pour point (-)15°C, copper corrosion EXAMPLE 10 PREPARATION OF INSULATING FLUID : The base stock (B) in 99.86 % (w/w) was blended with performance additives 4-methyl-2,6-di-(t-butyl) phenol, in 0.02 % (w/w) concentration, silicone oil in 0.01 % (w/w) concentration, sodium alkyl benzene sulfonate in 0.06 % (w/w), polyvinylacrylate in 0.01 % (w/w), and calcium phenolates of hydrogenated pentadecyl phenol in 0.04 % (w/w) concentration. The doping was done at 60°C with stirring for 2 hours. The fluid has viscosity, cst at 27°C was 9.5, viscosity index was 164, flash point 194°C, pour point (-)15°C, copper corrosion EXAMPLE 11 PREPARATION OF INSULATING FLUID : The base stock (C) in 99.84 % (w/w) was blended with performance additives N-tetra propylene 5-amino tetrazole in 0.02 % (w/w) concentration, silicone oil in 0.01 % (w/w) concentration, octyl phosphonates in 0.01 % (w/w), polyacrylate in 0.01 % (w/w), and magnesium alkyl benzene sulfonates having base number 500 in 0.01 % (w/w) concentration. The doping was done at 60°C with stirring for 2 hours. The fluid has viscosity, cst at 27°C was 11.8, viscosity index was 163, flash point 196°C, pour point (-)15°C, copper corrosion EXAMPLE 12 PREPARATION OF INSULATING FLUID: The base stock (D) in 99.845 % (w/w) was blended with performance additives 5-amino tetrazole 2,6,di-tert. butyl phenol in 0.025 % (w/w) concentration, silicone oil in 0.01 % (w/w) concentration, Propylene tetramer succinimide of pentaethylene hexamine in 0.07 % (w/w), polyvinylacrylate in 0.01 % (w/w), and octyl 1H benzotriazole in 0.04 % (w/w) concentration. The doping was done at 60°C with stirring for 2 hours. The fluid has viscosity, cst at 27°C was 7.6, viscosity index was 170, flash point 182°C, pour point (-)12°C, copper corrosion EXAMPLE 13 • PREPARATIpN OF INSULATING FLUID: The base stock (E) in 99.72 % (w/w) was blended with performance additives 5-amino tetrazole 2,6,di-tert. butyl phenol in 0.03 % (w/w) concentration, silicone oil in 0.02 % (w/w) concentration, Propylene tetramer succinimide of pentaethylene hexamine in 0.1 % (w/w), polyvinylacrylate in 0.05 % (w/w), and octyl 1H benzotriazole in 0.08 % (w/w) concentration. The doping was done at 60°C with stirring for 2 hours. The fluid has viscosity, cst at 27°C was 9.9, viscosity index was 168, flash point 252°C, pour point (-)15°C, copper corrosion EXAMPLE 14 CHARACTERIZATION AND EVALUATION OF LUBE OIL: The formulations were analyzed and evaluated as per ASTM or BIS methods such as ASTM D445/BIS-14234, P25/56 -K.Viscosity & Viscosity index, ASTM D 92/BIS-P21/69- Flash point, ASTM D1217/BIS-P16 - Rel.Density, ASTM D130/BIS-P15-Copper corrosion, ASTM D97/BIS-P10- Pour point, ASTM D874/BIS-P4- Ash sulfated, ASTM D 664/BIS-P1- TAN, ASTM D4377/BIS-P40- Water, IP 280, 306, 307-Oxidation Test, BIS 6792 Electrical strength, BIS 6103- Specific resistance, BIS6104- Interfacial Tension, BIS6262-Dessipation factor, and ASTM 5864-Biodegradability ADVANTAGES OF THE INVENTION The advantage of this invention that the composition of the insulating fluid based on non-edible vegetable oil derivatives from an renewable source of the present invention is significantly eco-friendly, safe due to higher flash point, beneficial to the farmers and provides better or equivalent performance as mineral oil based insulating fluids. We Claim : 1. An insulating fluid composition comprising: i) mono-esters of non-edible vegetable oils fatty acid monoester of fatty acid with C1 to C16 preferably C7 to C8 primary alcohol in the range of 97.70-99.894 wt%, ii) anti-oxidant selected from the group consisting of hindered phenol, alkyl amine, amino phenol and tetrazole, in the range of 0.006-0.05% by weight, iii) detergent -dispersant selected from the group consisting of sulfonate, succinimide and phosphonates in the range of 0.05- 0.15 % by weight, iv) anti-foaming agent selected from the group consisting of silicone and polymer compound in the range of 0.01 to 1.0% by weight, v) pour point dispersant selected from the group consisting of adipate and acrylate in the range of 0.01 to 1.0% by weight, vi) corrosion inhibitor selected from the group consisting of azole, Gallate, polyols, amines, phenols and sulfonates in the range of 0.03-0.1% by weight. 2. An insulating fluid composition as claimed in claiml, wherein, mono-esters of non-edible vegetable oils fatty acid selected from the group consisting of butyl-9-octadecenoic ester of formula-[C8H17CH=CHC7H14COOC4H9], ethyl-(10-epoxy)-9-octadecenoic ester, of formula [C8H17(>O)CH=CHC7H14COOC2H5], 2-propyl-(10-tolune)-9-octadecenoic ester of formula [C8H17(-C6H4CH3)CH=CHC7H14 COO C3H7 ] and a mixture thereof. 3. The composition as claimed in claim 1, wherein the mono-ester of vegetable oil fatty acid used is selected from the group consisting of simple ester, partially hydrogenated ester, epoxy ester, aryl alkyl ester of fatty acids and a mixture thereof. 4. The composition as claimed in claims 1-3, wherein the non-edible vegetable oil triglyceride fatty acid used for making ester is selected from the group consisting of C18:1, C18:2, C18:3, having the mono-unsaturation character in the range of about 50 to 70 weight percent. 5. The composition as claimed in claim 1| wherein the non-edible vegetable oil used is selected from the group consisting of karanja (Pongamia glabra) oil, neem (Mellia azadirachta) oil, ricebran (Oryza sativa) oil, mahua (Madhuca indica) oil, castor (Ricinus communis) oil, acetylated castor, linseed (flax-Linium usitatissimum) oil, other vegetable oils and a mixture thereof. 6. The composition as claimed in claim 1, wherein the non-edible vegetable oil used is preferably selected from the group consisting of karanja, ricebran, mahua, neem and a mixture thereof. 7. The composition as claimed in claim 1, wherein the mono-esters of fatty acids used as base stock have viscosity (cst) of at most 27 cst, at about 27°C and a flash point of at least 150°C (Cleveland Open Cup). 8. The composition as claimed in claim 1, wherein the anti-oxidant used is preferably selected from the group consisting of 4-methyl-2,6-di-(t-butyl) phenol, Methyl hydroxy hydro cinnamide, N-tetra propylene 5-amino tetrazole and 5-amino tetrazole 2,6,di-tert. butyl phenol. 9. The composition as claimed in claim 1, wherein the detergent-dispersant used is selected from the group consisting of calcium alkyl benzene sulfonate, sodium alkyl benzene sulfonate, propylene teramer succinimide of pentaethylene hexamine and octyl phosphonates. 10.The composition as claimed in claim 1, wherein the anti-foaming agent used is selected from the group consisting of silicone oil, polyvinyl alcohol, and polyethers. 11. The composition as claimed in claim 1, wherein the anti-foaming agent used is preferably selected from the group consisting of silicone oil and polyvinyl alcohol. 12.The composition as claimed in claim 1, wherein the pour point depressants used is selected from the group consisting of diethylhexyl adipate, polymethacrylate and polyvinylacrylate. 13.The composition as claimed in claim 1, wherein the rust or anti-corrosion additive used is selected from the group consisting of octyl 1H benzotriazole, ditertiary butylated 1 H-Benzotriazole, propyl gallate, polyoxyalkylene polyols, octadecyl amines, nonyl phenol ethoxylates, calcium phenolates of hydrogenated pentadecyl phenol and magnesium alkyl benzene sulfonates. 14.The composition as claimed in claim 1, wherein the rust or anti-corrosion additive used is preferably selected from the group consisting of ditertiary butylated 1 H-Benzotriazole, magnesium alkyl benzene sulfonates, and octadecyl amines. 15.The composition as claimed in claim 1, having the following characteristics: i. kinetic viscosity at 27°C is in the range of 5-27 cst, ii. viscosity index is between 160-300, iii. oxidation stability is Pass (IP 48/97) iv. rotatory bomb oxidation test (ROBOT) at 95°C is between 80-190 min., v. flash point is between 170-260°C, vi. pour point is between (-)15- (-)25°C, vii. ash sulfated % is viii. copper Strip corrosion test 1A, ix. foam test ASTM D892 Pass, x. interfacial tension against water is between 40-60 N/m, xi. reactive sulfur- NIL, xii. electrical strength is between 30-50KV, xiii. dissipation factor is between 0.002 - 0.2 xiv. specific Resistance (ohm-cm) at 90°C is between 34-38 xv. density at 20°C is between 0.880-0.884. xvi. biodegradability is between 90-100%.

Documents:

781-del-2006-abstract.pdf

781-del-2006-claims.pdf

781-del-2006-Correspondence-Others-(05-02-2013).pdf

781-del-2006-correspondence-others.pdf

781-del-2006-description(complete).pdf

781-del-2006-description(provisional).pdf

781-del-2006-form-1.pdf

781-del-2006-form-2.pdf

781-del-2006-Form-3-(05-02-2013).pdf

781-del-2006-form-3.pdf

781-del-2006-form-5.pdf