US 20080135817A1 (19) United States (12) Patent Application Publication (10) Pub. No.: US 2008/0135817 A1 Luly et al. (43) Pub. Date: Jun. 12, 2008

(54) GASEOUS DIELECTRICS WITH LOW (22) Filed: Dec. 12, 2006 GLOBAL WARMING POTENTIALS Publication Classification (75) Inventors: Matthew H. Luly, Hamburg, NY (51) Int. Cl. (US); Robert G. Richard, HOIB 3/20 (2006.01) Hamburg, NY (US) (52) U.S. Cl...... 252/571 Correspondence Address: (57) ABSTRACT Honeywell International Inc. A dielectric gaseous compound which exhibits the following Patent Services Department properties: a boiling point in the range between about -20° 101 Columbia Road C. to about -273°C.; non-ozone depleting; a GWP less than Morristown, NJ 07962 about 22,200; chemical stability, as measured by a negative standard enthalpy of formation (dElf<0); a toxicity level such (73) Assignee: Honeywell International Inc. that when the dielectric gas leaks, the effective diluted con centration does not exceed its PEL; and a dielectric strength (21) Appl. No.: 11/637,657 greater than air. US 2008/O 135817 A1 Jun. 12, 2008

GASEOUS DELECTRICS WITH LOW –63.8°C., which allows pressures of 400 kPa to 600 kPa (4 GLOBAL WARMING POTENTIALS to 6 atmospheres) to be employed in SF-insulated equip ment. It is easily liquefied underpressure at room temperature 1. FIELD allowing for compact storage in gas cylinders. It presents no handling problems, is readily available, and reasonably inex 0001. The present disclosure relates generally to a class of pensive. gaseous dielectric compounds having low global warming 0006 SF replaced air as a dielectric in gas insulated potentials (GWP). In particular, such gaseous dielectric com equipment based on characteristics such as insulation ability, pounds exhibits the following properties: a boiling point in boiling point, compressibility, chemical stability and non the range between about -20°C. to about -273° C.; low, toxicity. They have found that pure SF, or SF-nitrogen preferably non-ozone depleting; a GWP less than about mixtures are the best gases to date. 22,200; chemical stability, as measured by a negative stan 0007. However, SF has some undesirable properties: it dard enthalpy of formation (dHf<0); a toxicity level such that can form highly toxic and corrosive compounds when Sub when the dielectric gas leaks, the effective diluted concentra jected to electrical discharges (e.g., SF SOF); non-polar tion does not exceed its PEL, e.g., a PEL greater than about contaminants (e.g., air, CF) are not easily removed from it: 0.3 ppm by Volume (i.e., an Occupational Exposure Limit its breakdown Voltage is sensitive to water vapor, conducting (OEL or TLV) of greater than about 0.3 ppm); and a dielectric particles, and conductor Surface roughness; and it exhibits strength greater than air. These gaseous dielectric compounds non-ideal gas behavior at the lowest temperatures that can be are particularly useful as insulating-gases for use with elec encountered in the environment, i.e., in cold climatic condi trical equipment, such as gas-insulated circuit breakers and tions (about -50° C.). SF becomes partially liquefied at current-interruption equipment, gas-insulated transmission normal operating pressures (400 kPa to 500 kPa). SF is also lines, gas-insulated transformers, or gas-insulated Substa an efficient infrared (IR) absorber and due to its chemical tions. inertness, is not rapidly removed from the earth's atmosphere. Both of these latter properties make SF a potent greenhouse 2. BACKGROUND gas, although due to its chemical inertness (and the absence of 0002 Sulfur hexafluoride (SF) has been used as a gas chlorine and bromine atoms in the SF molecule) it is benign eous dielectric (insulator) in high Voltage equipment since the with regard to stratospheric ozone depletion. 1950s. It is now known that SF6 is a potent greenhouse 0008 That is, greenhouse gases are atmospheric gases Warming gas with one of the highest global Warming poten which absorb a portion of the infrared radiation emitted by the tials (GWP) known. Because of its high GWP, it is being earth and return it to earth by emitting it back. Potent green phased out of all frivolous applications. However, there is house gases have strong infrared absorption in the wavelength currently no known Substitute for SF in high Voltage equip range from approximately 7 um to 13 Jum. They occur both ment. The electrical industry has taken steps to reduce the naturally in the environment (e.g., H2O, CO., CH, NO)and leak rates of equipment, monitor usage, increase recycling, as man-made gases that may be released (e.g., SF, perfluori and reduce emissions to the atmosphere. However, it would nated compound (PFC); combustion products such as CO, still be advantageous to find a substitute for SF in electrical nitrogen, and Sulfur oxides). The effective trapping of long dielectric applications. wavelength infrared radiation from the earth by the naturally 0003. The basic physical and chemical properties of SF, occurring greenhouse gases, and its reradiation back to earth, its behavior in various types of gas discharges, and its uses by results in an increase of the average temperature of the earth's the electric power industry have been broadly investigated. Surface. Mans impact on climate change is an environmental 0004. In its normal state, SF is chemically inert, non issue that has prompted the implementation of the Kyoto toxic, non-flammable, non-explosive, and thermally stable (it Protocol regulating the emissions of man made greenhouse does not decompose in the gas phase attemperatures less than gases in a number of countries. 500° C.). SF exhibits many properties that make it suitable 0009 SF is an efficient absorber of infrared radiation, for equipment utilized in the transmission and distribution of particularly at wavelengths near 10.5 Lum. Additionally, electric power. It is a strong electronegative (electron attach unlike most other naturally occurring greenhouse gases (e.g., ing) gas both at room temperature and at temperatures well CO, CH). SF is only slowly decomposed; therefore its above ambient, which principally accounts for its high dielec contribution to global warming is expected to be cumulative tric strength and good arc-interruption properties. The break and long lasting. The strong infrared absorption of SF and its down Voltage of SF is nearly three times higher than air at long lifetime in the environment are the reasons for its atmospheric pressure. Furthermore, it has good heat transfer extremely high global warming potential which for a 100 properties and it readily reforms itself when dissociated under year time horizon is estimated to be approximately 22.200 high gas-pressure conditions in an electrical discharge or an times greater (per unit mass) than that of CO, the predomi arc (i.e., it has a fast recovery and it is self-healing). Most of nant contributor to the greenhouse effect. The concern about its stable decomposition byproducts do not significantly the presence of SF in the environment derives exclusively degrade its dielectric strength and are removable by filtering. from this very high value of its potency as a greenhouse gas. It produces no polymerization, carbon, or other conductive 0010. Accordingly, many in the electrical equipment deposits during arcing, and its is chemically compatible with industry have spent Substantial time and effort seeking Suit most Solid insulating and conducting materials used in elec able replacement gases to reduce the use of SF in high Volt trical equipment attemperatures up to about 200° C. age electrical equipment. To date, the possible replacement 0005 Besides it good insulating and heat transfer proper gases have been identified as (i) mixtures of SF and nitrogen ties, SF has a relatively high pressure when contained at for which a large amount of research results are available; (ii) room temperature. The pressure required to liquefy SF at 21° gases and mixtures (e.g., pure nitrogen, low concentrations of C. is about 2100 kPa; its boiling point is reasonably low, SF in N, and SF. He mixtures) for which a smaller yet US 2008/O 135817 A1 Jun. 12, 2008

significant amount of data is available; and (iii) potential trifluoro-nitroso-ethene?/Trifluor-nitroso-aethen gases for which little experimental data is available. 0011. Some replacements which have been proposed have Tetrafluoroethene higher GWPs than SF. For example, CFSF's falls into this 0017 3,3,4,4-tetrafluoro-3,4-dihydro-1,2diazete category. Because of fugitive emissions in the manufacture, transportation, filling and use of Such chemicals, they should (Difluoramino)difluoracetonitril be avoided. Tetrafluorooxirane 0012 However, the present inventors have determined that given the environmental difficulty of SF, it is necessary to Trifluoroacetyl fluoride relax certain of the requirements traditionally held as impor Perfluorimethylfluorformiat tant and accept as an alternative gas, compromise candidates with a lower GWP. For example, gases which are non-toxic 0018 trifluoro-acetyl hypofluorite are often inert with long atmospheric lifetimes which can perfluoro-2-aza-1-propene yield high GWP. By accepting a somewhat more reactive gas than SF, the GWP can be greatly reduced. It may also be Perfluor-2-aza-1-propen (germ.) necessary to accept slightly more toxic materials in order to find the best alternative in these applications. Such an N-Fluor-tetrafluor-1-aethanimin (germ.) increase intoxicity can be offset by reducing equipment leak 0019. 3.3-difluoro-2-trifluoromethyl-oxaziridine rates or installing monitoring equipment. In some cases, the bis-trifluoromethyl-diazene/hexafluoro-icis-azomethane gases discovered by the present inventors as Suitable alterna tives to SF are show to be efficient at low levels and can be Fluoroxypentafluoroethane mixed with nitrogen and/or another non-toxic gas to give dielectrics with greatly reduced toxicity and acceptably low (0020 bis-trifluoromethyl peroxide GWPS. 1,1-Bis(fluoroxy)tetrafluoroaethan 0013 The unique gaseous compounds discovered by the present inventors for use as substitutes for SF can be used in Hexafluorodimethyl sulfide Some existing electrical equipment, although they would preferably be used in specific electrical equipment optimized 0021 3-fluoro-3#H!-diazirine-3-carbonitrile for them. The gaseous compounds of the present disclosure Ethyne are preferably used in pure form, but can also be used as part of an azeotrope, or a mixture with an appropriate second gas, 0022 1.2.2-trifluoro-aziridine such as nitrogen, CO or NO. Ketene SUMMARY (0023 (difluoro)vinylboran 0014. A dielectric gaseous compound which exhibits the (Difluor)vinylboran (germ.) following properties: a boiling point in the range between about -20°C. to about -273°C.; low, preferably non-ozone 0024 trifluoro-vinyl-silane depleting; a GWP less than about 22,200; chemical stability, as measured by a negative standard enthalpy of formation Ethinylsilan (dHf<0); a toxicity level such that when the dielectric gas (0025 ethyl-difluor-borane leaks, the effective diluted concentration does not exceed its PEL (i.e., an Occupational Exposure Limit (OEL or TLV) of Ethyl-difluor-boran (germ.) at least about 0.3 ppm); and a dielectric strength greater than a1. 0026 methyl-methylen-amine 0015 The dielectric gaseous compound is at least one compound selected from the group consisting of Dimethyl ether (0027 vinyl-silane Arsenic pentafluoride Arsine Dimethylsilane Diboron tetrafluoride Chloroethyne 0028 fluoroethyne/fluoro-acetylene Diborane Perchloric acid, 2-chloro-1,1,2,2-tetrafluoroethyl ester (9CI) Ethanedinitrile Perchloric acid, 1.2.2-trichloro-1,2-difluoroethyl ester 0029 tetrafluoropropyne?/1,3,3,3-tetrafluoropropyne hexafluoro-oxetane Trifluoroacetyl chloride 0016 trifluoromethylisocyanide (CF3-NC) Trifluoro(trifluoromethyl)oxirane trifluoromethyl isocyanide 1,1,1,3,3,3-Hexafluoropropanone US 2008/O 135817 A1 Jun. 12, 2008

0030 pentafluoro-propionyl fluoride?/perfluoropropionyl #Sil-bromo-it-Sil. iSi!'-methanediyl-bis-silane fluoride #Si-iodo-it-Sili Si'-methanediyl-bis-silane Trifluoromethyl trifluorovinyl ether Difluormethylnitrit 1-Propyne 0039 trifluoromethanol Cyclopropane Formyl fluoride Propane Cyanic acid Trimethylborane Chlorine 0031 cyanoketene Chlorine fluoride butatriene Chlorine trioxide fluoride Cyano-bispentafluorethyl-phosphin 0040 carbon oxide selenide/Kohlenoxidselenid Trimethyl-1,1,2,2-tetrafluorethylsilan 0032 methyl diborane Fluorine Difluorosilane Methyldiboran (germ.) Fluorine oxide 0033 carbonyl bromide fluoride chloro-difluoro-nitroso-methane?/Chlor-difluor-nitroso 0041 fluorine peroxide methan chloroperoxytrifluoromethane Sulfuryl fluoride carbonylchlorid-fluorid 0042 sulphur difluoride Carbonychloridifluorid (germ.) Phosphorus trifluoride oxide 0034 33-difluoro-3HH-diazirine Phosphorus trifluoride sulfide difl1UOO C187Oleadi th 0043 tetrafluorophosphorane Difluordiazomethan (germ.) Tetrafluorohydrazine Carbonyl fluoride Sulfur tetrafluoride Difluordioxiran 0044 hexafluoro disiloxane 0035 difluoro-(3-fluoro-3HH!-diazirin-3-yl)-amine trifluoromethylazide Hexafluordisiloxan (germ.) Trifluormethylazid (germ.) Nitryl fluoride 0036 tetrafluoro-diaziridine Hydrogen Hydrogen selenide Fluorperoxytrifluorimethan Phosphorus trihydride Bis(fluoroxy)difluormethan Germanium hydride Trifluormethyl-phosphonylfluorid Silane Cyanogen fluoride Tin tetrahydride Trifluorimethylphosphane (germ.) Oxygen Diazomethane OZone 0037 formaldehyde/Formalin (methyl)difluoroborane Antimony monophosphide (Methyl)difluorboran (germ.) Disilicon monophosphide Radon Chloromethane Argon 0038 methylphosphonous acid difluoride/difluoro-me thyl-phosphine Trifluoroborane trifluoro-methoxy-silane Hydrogen bromide Methylhypofluorid Bromopentafluoroethane Methane Chlorotrifluoroethene Methylsilane Trifluoroacetonitrile US 2008/O 135817 A1 Jun. 12, 2008

0045 trifluoromethyl isocyanate tetrafluorocyclopropene trifluoromethyl thiocarbonyl fluoride Perfluoropropionyliodid Trifluormethylthiocarbonylfluorid (germ.) 0053 pentafluoro-propionitrile?/pentafluoropropiononi 0046) pentafluoro-nitroso-ethane//Pentafluor-nitroso trile aethan hexafluoro-cyclopropane?/Hexafluor-cyclopropan//freon (trifluoromethyl-carbonyl)-difluoro-amine HCl216 Hexafluoropropylene Hexafluoroethane 0054 hexafluoro-1,3dioxolane Bis-trifluorimethyl-nitroxid Octafluoropropane 0047 bis-trifluoromethyl ether bis(trifluoromethyl)tellurium Perfluormethylethylether bis(trifluoromethyl)ditelluride 0055 1,1-difluoro-propadiene/allenylidene difluoride/1. 1-difluoro-allene N,N-Difluor-pentafluoraethylarnin (germ.) 2,3,3,3-tetrafluoro-propene/HFO-1234yf N-Fluor-bis(trifluorimethyl)-amin (germ.) trans. HFO-1234ze N-Fluor-N-trifluorimethoxy-perfluormethylamin (germ.) 3,3,3-Trifluoropropene 0048 fluoroformyl cyanide 0056 cyclopropene 1-chloro-1-fluoro-ethene/71-Chlor-1-fluor-aethen//1-chloro Allene 1-fluoroethylene 0057 1,1-difluoro-propene/propenylidene difluoride/1. 1-Difluor-propen 1,1-Difluoroethene methylketene 0049 it trans-1,2-difluoro-ethene/#trans-vinylene dif 2-fluoropropene luoride/(E)-1,2-difluoroethylene?/(E)-1,2-difluoro-ethene/ itrans-vinylene fluoride 1-Propene 1,2-difluoro-ethene/icis-vinylene difluoride/1.2-Difluor DL-2-aminopropanoic acid aethen//vinylene fluoride icis-1,2-difluoro-ethene//icis-Vinylene difluoride//(Z)-1, 0058 3,3,3-trifluoro-propyne/3,3,3-Trifluor-propin/trif 2-difluoroethylene//(Z)-1,2-difluoro-ethene/icis-Vinylene luoromethyl-ethyne/3,3,3-trifluoro-1-propyne fluoride 1,1,3,3,3-pentafluoro-propene/1,1,3,3,3-Pentafluor-propen 1.2.3.3.3-pentafluoro-propene 1,1,1,2-Tetrafluoroethane 1.1.1.4.4.4-hexafluoro-2-butyne 1,1,4,4-tetrafluoro-butane-2,3-dione 1,1,2,2-Tetrafluoroethane Fluoroethene Trifluormethylhypochlorit Chlor-difluor-methyl-hypofluorit 1,1,1-Trifluoroethane N-Chlor-N-fluor-trifluorimethylamin (germ.) Ether, methyl trifluoromethyl Chlordifluordifluoraminomethan Ethene 0059 thiocarbonyl difluoride 1,1-Difluoroethane Thiocarbonyldifluorid (germ.) Fluoroethane 0060 selenocarbonyl difluoride Ethane 0050 fluoro-dimethyl-borane Trifluoroiodomethane N-Fluor-difluorimethanimin (germ.) Disiloxane, 1,1,3,3-tetrafluoro-1,3-dimethyl-Trifluoroethene 0061 trifluoro-nitroso-methane/Trifluor-nitroso-methan 0051 trifluoroacetaldehyde?/Trifluor-acetaldehyd difluoro-carbamoyl fluoride trifluoro-nitro-methane/Trifluor-nitro-methan//fluoropicrin Pentafluoroethane Tetrafluoromethane Difluoromethyl trifluoromethyl ether Tetrafluorformamidin (germ.) Tris(trifluoromethyl)bismuth 0062 tetrafluorourea 0052 tetrafluoropropadiene/tetrafluoro-allene/ 1,1,3,3- hypofluorous acid trifluoromethyl ester//Hypofluorigsaeure tetrafluoro-1,2-propadiene trifluorimethylester//trifluoromethyl hypofluorite US 2008/O 135817 A1 Jun. 12, 2008

trifluoromethanesulfonyl fluoride (0071 thiazyl trifluoride N,N-Difluor-trifluorimethylamin (germ.) Phosphorus trifluoride Trifluormethyloxydifluoramin Germanium(IV) fluoride (Difluoraminoxy)difluorimethylhypofluorit Tetrafluorosilane 0063 sulfurcyanide pentafluoride Phosphorus pentafluoride Schwefelcyanid-pentafluorid (germ.) Selenium hexafluoride 0064 difluoro-trifluoromethyl-phosphine Tellurium hexafluoride 0072 fluorosilane Hexafluormethandiamin 0065 perfluoro methylsilane Nitrosyl fluoride Fluorine nitrate Perfluorimethylsilan (germ.) Hydrogen sulfide Trifluormethyl-tetrafluorphosphoran (germ.) Ammonia Difluoromethane Helium Fluoroiodomethane Hydrogen iodide 0066 fluoromethane/methyl fluoride/Fluor-methan// freon-41 Krypton trifluoromethyl-silane' CF3SiH3 Nitrogen methyltrifluorosilane difluoro-methyl-silane (0073 dinitrogen oxide fluoro-methyl-silane methylgermane Neon Nitrogen oxide; and Difluorformimin Xenon Trifluoromethane 0074 More preferably, the dielectric compounds can be 0067 trifluoromethane thiol selected from the group consisting of: Trifluormethanthiol (germ.) Argon N.N.,1,1-Tetrafluorimethylamin Trifluoroborane 0068 difluoro dichlorosilane Hydrogen bromide Difluordichlorsilan (germ.) Bromopentafluoroethane 0069 difluoro chlorosilane Chlorotrifluoroethene Difluorchlorsilan (germ.) Trifluoroacetonitrile (0075 trifluoromethyl isocyanate Phosphorus chloride difluoride trifluoromethyl thiocarbonyl fluoride Chlorotrifluorosilane Hydrogen chloride Trifluormethylthiocarbonylfluorid (germ.) Chlorosilane 0076 pentafluoro-nitroso-ethane/Pentafluor-nitroso aethan Carbon monoxide (trifluoromethyl-carbonyl)-difluoro-amine Carbon dioxide Hexafluoroethane Carbonyl sulfide Bis-trifluorimethyl-nitroxid Difluoramine (0077 bis-trifluoromethyl ether 0070 trans-Difluorodiazine bis(trifluoromethyl)tellurium cis-Difluorodiazine bis(trifluoromethyl)ditelluride Thionyl fluoride N,N-Difluor-pentafluoraethylamin (germ.) Trifluorosilane N-Fluor-bis(trifluorimethyl)-amin (germ.) Nitrogen trifluoride N-Fluor-N-trifluorimethoxy-perfluormethylamin (germ.) Trifluoramine oxide (0078 fluoroformylcyanide US 2008/O 135817 A1 Jun. 12, 2008

1-chloro-1-fluoro-ethene/71-Chlor-1-fluor-aethen//1-chloro 2-fluoropropene 1-fluoroethylene 1,1-Difluoroethene itrans-1,2-difluoro-ethene//#trans-vinylene difluoride/ 1-Propene (E)-1,2-difluoroethylene/(E)-1,2-difluoro-ethene/#trans DL-2-aminopropanoic acid vinylene fluoride 1,2-difluoro-ethene/icis-vinylene difluoride/1.2-Difluor I0087 3,3,3-trifluoro-propyne/3,3,3-Trifluor-propin/trif aethen//vinylene fluoride luoromethyl-ethyne/3,3,3-trifluoro-1-propyne icis-1,2-difluoro-ethene//icis-Vinylene difluoride//(Z)-1, 1,1,3,3,3-pentafluoro-propene/1,1,3,3,3-Pentafluor-propen 2-difluoroethylene//(Z)-1,2-difluoro-ethene/icis-Vinylene 1.2.3.3.3-pentafluoro-propene fluoride 1.1.1.4.4.4-hexafluoro-2-butyne 1,1,4,4-tetrafluoro-butane-2,3-dione 1,1,1,2-Tetrafluoroethane Trifluormethylhypochlorit 1,1,2,2-Tetrafluoroethane Chlor-difluor-methyl-hypofluorit Fluoroethene N-Chlor-N-fluor-trifluorimethylamin (germ.) 1,1,1-Trifluoroethane Ether, methyl trifluoromethyl Chlordifluordifluoraminomethan Ethene I0088 thiocarbonyl difluoride 1,1-Difluoroethane Thiocarbonyldifluorid (germ.) Fluoroethane I0089 selenocarbonyl difluoride Ethane Trifluoroiodomethane 0079 fluoro-dimethyl-borane N-Fluor-difluorimethanimin (germ.) Disiloxane, 1,1,3,3-tetrafluoro-1,3-dimethyl-Trifluoroethene 0090 trifluoro-nitroso-methane/Trifluor-nitroso-methan 0080 trifluoroacetaldehyde?/Trifluor-acetaldehyd difluoro-carbamoyl fluoride trifluoro-nitro-methane/Trifluor-nitro-methan//fluoropicrin Pentafluoroethane Tetrafluoromethane Difluoromethyl trifluoromethyl ether Tris(trifluoromethyl)bismuth Tetrafluorformamidin (germ.) 0091 tetrafluorourea 0081 tetrafluoropropadiene/tetrafluoro-allene/ 1,1,3,3- hypofluorous acid trifluoromethyl ester//Hypofluorigsaeure tetrafluoro-1,2-propadiene trifluorimethylester//trifluoromethyl hypofluorite tetrafluorocyclopropene trifluoromethanesulfonyl fluoride Perfluoropropionyliodid N,N-Difluor-trifluorimethylamin (germ.) 0082 pentafluoro-propionitrile?/pentafluoropropiononi Trifluormethyloxydifluoramin trile hexafluoro-cyclopropane?/Hexafluor-cyclopropan//freon (Difluoraminoxy)difluorimethylhypofluorit HCl216 0092 sulfurcyanide pentafluoride Hexafluoropropylene Schwefelcyanid-pentafluorid (germ.) 0083 hexafluoro-1,3dioxolane 0093 difluoro-trifluoromethyl-phosphine Octafluoropropane Hexafluormethandiamin Perfluormethylethylether (0094 perfluoro methylsilane 0084 1,1-difluoro-propadiene/allenylidene difluoride/ 1,1-difluoro-allene Perfluorimethylsilan (germ.) 2,3,3,3-tetrafluoro-propene/HFO-1234yf Trifluormethyl-tetrafluorphosphoran (germ.) trans. HFO-1234ze Difluoromethane 3,3,3-Trifluoropropene Fluoroiodomethane I0085 cyclopropene 0.095 fluoromethane//methyl fluoride/Fluor-methan// freon-41 Allene trifluoromethyl-silane' CF3SiH3 I0086 1,1-difluoro-propene/propenylidene difluoride/1. methyltrifluorosilane 1-Difluor-propen difluoro-methyl-silane methylketene fluoro-methyl-silane US 2008/O 135817 A1 Jun. 12, 2008

methylgermane Neon Difluorformimin Nitrogen oxide; and Trifluoromethane Xenon 0102 The dielectric gaseous compound is optionally form 0096 trifluoromethane thiol as an azeotrope, which imparts many advantages in handling Trifluormethanthiol (germ.) the mixture. Preferred mixtures for dielectric gaseous com pound contain one additional gas selected from the group N.N.,1,1-Tetrafluorimethylamin consisting of nitrogen, CO and N.O. 0097 difluoro dichlorosilane 0103) The present disclosure also includes an insulation gas for use in electrical equipment, wherein said insulation Difluordichlorsilan (germ.) gas is a dielectric gaseous compound which exhibits the fol lowing properties: a boiling point in the range between about 0098 difluoro chlorosilane -20° C. to about -273° C.: low, preferably non-ozone depleting; a GWP less than about 22,200; chemical stability, Difluorchlorsilan (germ.) as measured by a negative standard enthalpy of formation Phosphorus chloride difluoride (dHf<0); a toxicity level such that when the dielectric gas Chlorotrifluorosilane leaks, the effective diluted concentration does not exceed its PEL (i.e., Occupational Exposure Limit (OEL or TLV) of at Hydrogen chloride least about 0.3 ppm); and a dielectric strength greater than air. Chlorosilane 0104 Preferably, the electrical equipment is at least one selected from the group consisting of gas-insulated circuit Carbon monoxide breakers and current-interruption equipment, gas-insulated Carbon dioxide transmission lines, gas-insulated transformers, and gas-insu lated Substations. Carbonyl sulfide DETAILED DESCRIPTION OF THE PREFERRED Difluoramine EMBODIMENT 0099 trans-Difluorodiazine 0105. The compounds of the present disclosure are useful cis-Difluorodiazine in gaseous phase for electrical insulation and for arc quench Thionyl fluoride ing and current interruption equipment used in the transmis sion and distribution of electrical energy. Generally, there are Trifluorosilane four major types of electrical equipment which the gases of the present disclosure can be used for insulation and/or inter Nitrogen trifluoride ruption purposes: (1) gas-insulated circuit breakers and cur Trifluoramine oxide rent-interruption equipment, (2) gas-insulated transmission lines, (3) gas-insulated transformers, and (4) gas-insulated 0100 thiazyl trifluoride Substations. Such gas-insulated equipment is a major compo nent of power transmission and distribution systems all over Phosphorus trifluoride the world. It offers significant savings in land use, is aestheti Germanium(IV) fluoride cally acceptable, has relatively low radio and audible noise emissions, and enables Substations to be installed in popu Tetrafluorosilane lated areas close to the loads. Phosphorus pentafluoride 0106 Depending on the particular function of the gas insulated equipment, the gas properties which are the most Selenium hexafluoride significant vary. Tellurium hexafluoride 0.107 For circuit breakers the excellent thermal conduc tivity and high dielectric strength of Such gases, along with 0101 fluorosilane the fast thermal and dielectric recovery (short time constant for increase in resistivity), are the main reasons for its high Nitrosyl fluoride interruption capability. These properties enable the gas to Fluorine nitrate make a rapid transition between the conducting (arc plasma) and the dielectric state of the arc, and to withstand the rise of Hydrogen sulfide the recovery Voltage. Ammonia 0.108 For gas-insulated transformers the cooling ability, compatibility with sold materials, and partial discharge char Helium acteristics, added to the dielectric characteristics, make them Hydrogen iodide a desirable medium for use in this type of electrical equip ment. The compounds have distinct advantages over oil insu Krypton lation, including none of the fire safety problems or environ Nitrogen mental problems related to oil, high reliability, flexible layout, little maintenance, long service life, lower noise, bet Nitrous oxide ter handling, and lighter equipment. US 2008/O 135817 A1 Jun. 12, 2008

0109 For gas-insulated transmission lines the dielectric 0114 Extrinsic properties are those which describe how a strength of the gaseous medium under industrial conditions is gas may interact with its Surroundings, or in response to of paramount importance, especially the behavior of the gas external influences, such as electrical breakdown and dis eous dielectric under metallic particle contamination, Switch charges. To be used in electrical applications, a dielectric gas ing and lightning impulses, and fast transient electrical should: (undergo no extensive decomposition; lead to no stresses. These gases also have a high efficiency for transfer of polymerization; form no carbon or other deposits; and be heat from the conductor to the enclosure and are stable for non-corrosive and non-reactive to metals, insulators, spacers, long periods of time (e.g., 40 years). These gas-insulated and seals. In addition it should have: no byproduct with tox transmission lines offer distinct advantages: cost effective icity unacceptable for industrial applications; removable ness, high-carrying capacity, low losses, availability at all byproducts; and a high recombination rate for reforming Voltage ratings, no fire risk, reliability, and a compact alter itself, especially for arc interruption. Finally, the gas must be native to overhead high Voltage transmission lines in con environmentally friendly, e.g., it must not contribute to global gested areas that avoids public concerns with overhead trans warming, must not deplete stratospheric oZone, and must not mission lines. persist in the environment for long periods of time. 0110. For gas-insulated substations, the entire substation 0115 Specific properties of the gas under discharge and (circuit breakers, disconnects, grounding Switches, busbar, breakdown conditions include: a high breakdown Voltage transformers, etc., are interconnected) is insulated with the under uniform and non-uniform electric fields; insensitivity gaseous dielectric medium of the present disclosure, and, to surface roughness or defects and freely moving conducting thus, all of the above-mentioned properties of the dielectric particles; good insulation properties under practical condi gas are significant. tions; good insulator flashover characteristics; good heat 0111. The properties of a dielectric gas that are necessary transfer characteristics; good recovery (rate of Voltage recov for its use in high Voltage equipment are many and vary ery) and self-healing; no adverse reactions with moisture and depending on the particular application of the gas and the common impurities; and no adverse effects on equipment, equipment. especially on spacers and electrode surfaces. 0112 Intrinsic properties are those properties of a gas 0116 Specific properties of gaseous insulators for specific which are inherent in the physical atomic or molecular struc electrical equipment is set forth below: ture of the gas. These properties are independent of the appli Circuit breakers—The most significant required gas proper cation or the environment in which a gas is placed. One of the ties for arc interruption are: (i) high dielectric strength com desirable properties of a gaseous dielectric is high dielectric parable to that of SF; (ii) high thermal conductivity; (iii) fast strength (higher, for instance than air). The gas properties that gas recovery; and (iv) self-healing/dielectric integrity. are principally responsible for high dielectric strength are Gas-insulated transmission lines—The required properties those that reduce the number of electrons which are present in include: (i) high dielectric strength; (ii) high vapor pressure at an electrically-stressed dielectric gas. To effect Such a reduc operating and ambient temperature; (iii) chemical inertness; tion in the electron number densities, as gas should: (i) be (iv) high thermal conductivity; (v) no thermal aging; (vi) no electronegative (remove electrons by attachment over as wide deposits; (vii) easily removable, non-harmful byproducts; an energy range as possible); it should preferably exhibit and (viii) no unacceptable level of hazards (fire, explosion, increased electron attachment with increasing electron toxicity, corrosion). energy and gas temperature since electrons have a broad Gas-insulated transformers—The properties of the gas range of energies and the gas temperature in many applica required for this application include: (i) high dielectric tions is higher than ambient; (ii) have good electron slowing strength at reasonable pressures (e.g., 500 kPa); (ii) low boil down properties (slow electrons down so that they can be ing point; (iii) acceptably low toxicity; (iv) chemical inert captured efficiently at lower energies and be prevented from ness; (V) good thermal stability; (vi) non-flammable; (vii) generating more electrons by electron impactionization); and high cooling capability; (viii) good compatibility with Solid (iii) have low ionization cross section and high ionization materials; (ix) good partial discharge characteristics; (X) use onset (prevent ionization by electron impact). Besides the able over a range of temperatures; and (xi) safe, easy to above properties, there are a number of other basic properties handle, inexpensive and securely available. which are necessary for the complete characterization of the 0117 The present inventors have discovered a unique dielectric gas behavior and its performance in practice, e.g., series of dielectric gases for use in electric equipment appli secondary processes such as electron emission from Surfaces cations, which exhibit many of the aforementioned proper by ion and photon impact; photoprocesses; absorption of ties, which avoiding the greenhouse problems associated with photoionizing radiation (this is a controlling factor in dis SF. Such dielectric compounds exhibit at least one of the charge development in non-uniform fields); dissociation following properties: under electron impact decomposition; ion-molecule reac 0118. A boiling point in the range between about -20° tions; reactions with trace impurities; and reactions with Sur C. to about -273° C. faces. 0119 Low, preferably, Non-ozone depleting 0113. The dielectric gas must also have the following 0120 A GWP less than about 22,200 chemical properties: high vapor pressure; high specific heat, 0121 Chemical stability, as measured by a negative high thermal conductivity for gas cooling; thermal stability standard enthalpy of formation (dHf<0) over long periods of time for temperatures greater than 400° 0.122 A toxicity level such that when the working gas K; chemical stability and inertness with regard to conducting leaks from equipment at the manufacturer's specified and insulating materials; non-flammable; toxicity acceptable maximum leak rate, the effective diluted concentration for industrial exposure; and non-explosive. When used in does not its PEL, i.e., does not exceed the PEL of that mixtures, it must have appropriate thermodynamic properties specific compound. In general with minimal ventilation for mixture uniformity, composition, and separation. PELs greater than about 0.3 ppm by volume are accept

US 2008/O 135817 A1 Jun. 12, 2008 10

TABLE 1-continued

Dielectric Compound Structure Name CAS MW C3 ,1,1,3,3,3- 684-16-2 166.O2 -27.3 Hexafluoropropanone pentafluoro-propionyl 422-61-7 166.O2 -27.0 fluoride?/perfluoropropionyl fluoride Trifluoromethyl 1187-93-5 166.O2 -26.0 trifluorovinyl ether -Propyne 74-99-7 40.06 -23.2 Cyclopropane 75-19-4 42.08 -32.8 Propane 74-98-6 44.10 -42.0 Trimethylborane 593-90-8 55.92 -20.2 cyanoketene 4452-08-8 67.05 -34.0 butatriene 2873-SO-9 S2.08 -78.0 Cyano-bispentafluorethyl- 35.449-90-2 295.02 -78.0 phosphin Trimethyl-1,1,2,2- 41 68-08-5 174.21 -72.O etrafluorethylsilan methyl diborane 23777-55-1 41.70 -350 Methyldiboran (germ.) CBrFO carbonyl bromide fluoride 753-56-0 126.91 -20.6 CCIF2NO chloro-difluoro-nitroso- 421-13-6 115.47 -350 methane, Chlor-difluor nitroso-methan CF3- O O. Cl chloroperoxytrifluoromethane 327SS-26-3 136.46 -22.0 COCIF carbonylchlorid-fluorid 353-49-1 82.46 -46.0 Carbonychloridifluorid (germ.) CF 3,3-difluoro-3#H-diazirine 693-85-6 -91.3 CF difluoro diazomethane 814-73-3 -91.3 Difluordiazomethan (germ.) Carbonyl fluoride 3S3-SO-4 66.01 -84.6 Difluordioxiran 96.740-99-7 82.01 -85.0 difluoro-(3-fluoro-3#H- 4823-43-2 111.03 -36.0 diazirin-3-yl)-amine C trifluoromethylazide 3802-95-7 110.03 -285 Trifluormethylazid (germ.) etrafluoro-diaziridine 17224-09-8 116.02 -350 Fluorperoxytrifluorimethan 34511-13-2 120.00 -69.4 Bis(fluoroxy)difluormethan 16282-67-O 120.00 -64.0 Trifluormethyl- 19162-94-8 153.98 -20.1 phosphonylfluorid Cyanogen fluoride 1495-SO-7 45.02 -46.2 Trifluormethylphosphane 420-52-O 102.00 -26.5 (germ.) Diazomethane 334-88-3 42.04 -23.2 ormaldehyde?/Formalin SO-OO-O 30.03 -21.0 (methyl)difluoroborane 373-64-8 63.84 -62.3 (Methyl)difluorboran (germ.) Chloromethane 74-87-3 SO.49 -24.2 methylphosphonous acid difluoridefidifluoro 84.01 -28.0 methyl-phosphine trifluoro-methoxy-silane 2S711-11-9 116.11 -78.0 Methylhypofluorid 36336-08-0 SO.O3 -33.0 Methane 74-82-8 16.04 -161.5 Methylsilane 992-94-9 46.14 -56.9 #Sil-bromo-#SilitSi!'- 56962-86-8 1SS.14 -64.0 methanediyl-bis-silane C #Si!-iodo-#SilitSi!'- 56962-87-9 2O2.14 -49.0 methanediyl-bis-silane F2CH O NO Difluorimethylnitrit 1493-06-7 97.02 -20.0 F3COH trifluoromethanol 1493-11-4 86.01 -20.0 HFCO Formyl fluoride 1493-02-3 48.02 -26.5 HOCN Cyanic acid 420-05-3 43.03 -64.2 C2 Chlorine 7782-50-5 70.91 -34.0 CIF Chlorine fluoride 7790-89-8 S4.45 -101.0 Chlorine trioxide fluoride 7616-94-6 102.45 -46.7 carbon oxide 1603-84-5 106.97 -21.7 selenide? Kohlenoxidselenid Fluorine 77.82-41-4 38.00 -1882 Difluorosilane 13824-36-7 68.10 -77.8 Fluorine oxide 7783-41-7 S400 -144.7 US 2008/O 135817 A1 Jun. 12, 2008 11

TABLE 1-continued

Dielectric Compound Structure Name CAS MW FOOF fluorine peroxide 7783-44-0 70.00 -S7.0 SO2F2 Sulfuryl fluoride 2699-79-8 102.06 -SS3 SF2 sulphur difluoride 13814-25-0 70.06 -350 POF3 Phosphorus trifluoride 13478-20-1 103.97 -39.7 oxide PSF3 Phosphorus trifluoride 120.03 -52.3 sulfide etrafluorophosphorane 13659-66-0 107.98 -37.0 Tetrafluorohydrazine 10O36-47-2 104.01 -74.2 Sulfur tetrafluoride 7783-60-0 108.OS -40.5 hexafluoro disiloxane 1451S-39-0 186.16 -23.0 Hexafluordisiloxan (germ.) Nitryl fluoride 10O22-SO-1 6S.OO -72.3 Hydrogen 1333-74-0 2.02 -2529 Hydrogen selenide 7783-07-5 80.98 -41.3 Phosphorus trihydride 78O3-51-2 34.00 -87.8 Germanium hydride 7782-6S-2 76.62 -88.2 Silane 78O3-62-5 32.12 -112.2 Tin tetrahydride 24O6-52-2 122.72 -51.8 Oxygen 7782-44-7 32.00 -183.0 Ozone 10O28-15-6 48.00 -111.3 Antimony monophosphide l 152.72 -52.3 Disilicon monophosphide l 87.14 -52.3 Radon 10043-92-2 222.00 -61.7 Argon 7440-37-1 39.95 -1859 Trifluoroborane 7637-07-2 67.81 -101.2 Hydrogen bromide 10O3S-1O-6 80.91 -66.7 Bromopentafluoroethane 354-55-2 98.92 -21.0 Chlorotrifluoroethene 79-38-9 16.47 -28.4 Trifluoroacetonitrile 353-85-5 95.02 - 68.8 trifluoromethyl isocyanate 460-49-1 11.02 -36.0 trifluoromethylthiocarbonyl fluoride 32.08 -21.0 Trifluorimethylthiocarbonylfluorid (germ.) C pentafluoro-nitroso 49.02 -45.7 ethane, Pentafluor-nitroso aethan C (trifluoromethyl-carbonyl)- 32822-49-4 -21.1 difluoro-amine Hexafluoroethane 76-16-4 -78.2 Bis-trifluormethyl-nitroxid 2154-71-4 -20.0 bis-trifluoromethyl ether 1479–49-8 -59.0 bis(trifluoromethyl)tellurium SS642-42-7 -98.0 bis(trifluoromethyl) 1718-20-3 -53.0 ditelluride N,N-Difluor -38.0 pentafluoraethylamin (germ.) N-Fluor-bis(trifluorimethyl)- 359-62-6 71.02 -37.0 amin (germ.) N-Fluor-N-trifluormethoxy 4217-92-9 87.02 -25.0 perfluorimethylamin (germ.) fluoroformyl cyanide 683-55-6 73.03 -21.0 1-chloro-1-fluoro-ethene, 1 2317-91-1 80.49 -2S.S Chlor-1-fluor-aethen 1 chloro-1-fluoroethylene CF2-CH2 1,1-Difluoroethene 75-38-7 64.03 -85.7 CHF CHF #trans-1,2-difluoro 1630-78-0 64.03 -53.1 ethenefiti trans-vinylene difluoride? (E)-1,2- difluoroethylene? (E)-1,2- difluoro-ethenefiti trans vinylene fluoride FHC-CHF 1,2-difluoro-ethenefiticist 1691-13-O 64.03 -28.0 vinylene difluoride?/1,2- Difluor-aethen vinylene fluoride CHF CHF #cis-1,2-difluoro 1630-77-9 64.03 -26.0 ethenefiticist-vinylene difluoride? (Z)-1,2- difluoroethylene, f(Z)-1,2- difluoro-ethenefiticist vinylene fluoride 1,1,1,2-Tetrafluoroethane 811-97-2 102.03 -26.1 US 2008/O 135817 A1 Jun. 12, 2008 12

TABLE 1-continued

Dielectric Compound Structure Name CAS MW 1.22-Tetrafluoroethane 359-35-3 102.03 -23.0 luoroethene 75-02-5 46.04 -72.2 1,1-Trifluoroethane 420-46-2 84.04 -47.3 Ether, methyl 421-14-7 100.04 -24.0 trifluoromethyl Ethene 74-85-1 28.05 -103.7 ,1-Difluoroethane 75-37-6 66.OS -24.0 3S3-36-6 48.06 -37.7 8le 74-84-O 30.07 -88.6 fluoro-dimethyl-borane 353-46-8 59.88 -44.0 Disiloxane, 1,1,3,3- 63O89-45-2 178.23 -39.0 etrafluoro-1,3-dimethyl Trifluoroethene 359-11-5 82O2 -510 trifluoroacetaldehyde?/Trifluor 75-90-1 98.02 -21.0 acetaldehy F5 Pentafluoroethane 354-33-6 2O.O2 -48.1 FSO Difluoromethyl 3822-68-2 36.02 -35.3 trifluoromethyl ether Tris(trifluoromethyl)bismuth S863-80-9 416.00 -SS.O etrafluoropropadienefitetrafluoro 461-68-7 12.03 -38.0 allene? (1,1,3,3- etrafluoro-1,2-propadiene etrafluorocyclopropene 19721-29-O 12.03 -20.0 Perfluoropropionyliodid 137741-03-8 273.93 -27.0 pentafluoropropionitrile?/ 422-04-8 45.03 -350 pentafluoropropiononitrile (X8OO 931-91-9 -33.0 cyclopropane? Hexafluor cyclopropan freon-#C216 Hexafluoropropylene 116-15-4 SO.O2 -29.6 hexafluoro-1,3dioxolane 21297-65-4 82O2 -22.1 Octafluoropropane 76-19-7 88.02 -36.7 Perfluormethylethylether 665-1 6-7 204.O2 -20.0 1-difluoro 430-64-8 76.05 -21.0 propadiene fallenylidene difluoride? 1,1-difluoro allene 2,3,3,3-tetrafluoro 754-12-1 114.04 -28.3 propene/HFO-1234yf EranSHFO-1234ze 114.04 -19.0 3,3,3-Trifluoropropene 677-21-4 96.OS -25.0 cyclopropene 2781-85-3 40.06 -36.0 Allene 463-49-O 40.06 -34.5 1-difluoro 430-63-7 78.06 -29.0 propenef propenylidene difluoride? 1,1-Difluor Oel methylketene 6004-44-0 56.06 -23.0 CH2CFCH3 2-fluoropropene 1184-60-7 60.07 -24.0 CH2CHCH3 -Propene 115-07-1 42.08 -47.7 DL-2-aminopropanoic acid 302-72-7 89.09 -50.2 3,3,3-trifluoro 661-54-1 94.04 -48.0 propyne? (3,3,3-Trifluor propini?trifluoromethyl ethyne? (3,3,3-trifluoro-1- propyne 1,1,3,3,3-pentafluoro 690-27-7 32.03 -21.0 propenef, 1,1,3,3,3- Pentafluor-propen ,2,3,3,3-pentafluoro 2252-83-7 32.03 -20.0 propene 1,144.4-hexafluoro-2- 692-50-2 62.03 -24.6 butyne 144-tetrafluoro-butane 58.05 -81.0 2,3-dione 14.10 -33.0 F3C O Cl Trifluormethylhypochlorit 22082-78-6 20.46 -47.0 CF2C OF Chlor-difluor-methyl 2O614-17-9 20.46 -25.0 hypofluorit CC N-Chlor-N-fluor 1388O-72-3 37.46 -32.8 trifluorimethylamin (germ.) CC CCF2 NF2 Chlordifluordifluoraminomethan 13880-71-2 37.46 -28.0 US 2008/O 135817 A1 Jun. 12, 2008 13

TABLE 1-continued

Dielectric Compound Structure Name CAS MW thiocarbonyl difluoride 420-32-6 82.07 -46.0 Thiocarbonyldifluorid (germ.) selenocarbonyl difluoride S4393-39-4 128.97 -28.0 Trifluoroiodomethane 2314-97-8 195.91 -21.8 N-Fluor-difluorimethanimin 338-66-9 83.01 -101.0 (germ.) trifluoro-nitroso- 334-99-6 99.01 -86.0 methane, Trifluor-nitroso methan difluoro-carbamoyl fluoride 2368-32-3 99.01 -52.0 trifluoro-nitro- 335-02-4 15.01 -33.6 methane, Trifluor-nitro methan fluoropicrin CF Tetrafluoromethane 75-73-0 88.00 -128.1 Tetrafluorformamidin 14362-70-0 16.O2 -3O.O (germ.) etrafluorourea 10256-92-5 -20.0 hypofluorous acid trifluoromethylester?, -95.0 Hypofluorigsa.eure trifluorimethylesteri?trifluoromethyl hypofluorite trifluoromethanesulfonyl 335-05-7 52.07 -21.7 fluoride CFSN N,N-Difluor- 335-01-3 21.01 -7S.O trifluorimethylamin (germ.) CFSNO Trifluormethyloxydifluoramin 4217-93-O 37.01 -59.8 CFSNO2 (Difluoraminoxy)difluorimethyl- 36781-60-9 53.01 -29.0 hypofluorit CFSNS SFSCN Sulfurcyanide pentafluoride 1512-13-6 53.08 -25.0 Schwefelcyanid pentafluorid (germ.) CFSP difluoro-trifluoromethyl- 1112-04-5 37.98 -43.0 phosphine Hexafluorimethandiamin 4394-93-8 54.O1 -37.0 perfluoro methylsilane 335-06-8 54.09 -42.0 Perfluormethylsilan (germ.) Trifluormethyl- 1184-81-2 75.97 -350 etrafluorphosphoran (germ.) Difluoromethane 75-10-5 S2.O2 -51.7 Fluoroiodomethane 373-53-5 59.93 -53.8 fluoromethanet methyl 593-53-3 34.03 -78.3 fluoride, Fluormethan reon-41 C trifluoromethyl-silane' 1O112-11-5 OO.12 -383 CF3SH3 methyltrifluorosilane 373-74-0 OO.12 -3O.O difluoro-methyl-silane 420-34-8 82.12 -35.6 fluoro-methyl-silane 753-44-6 64.13 -44.0 methylgermane 449-65-6 90.65 -23.0 Difluorformimin 2712-98-3 6S.O2 -22.0 Trifluoromethane 75-46-7 70.01 -82.1 trifluoromethane thiol 493-15-8 102.08 -36.7 Trifluormethanthiol (germ.) N,N,1,1- 24708-53-0 103.02 -43.0 Tetrafluormethylamin difluoro dichlorosilane 8356-71-3 136.99 -31.8 Difluordichlorsilan (germ.) difluoro chlorosilane 8OOO3-43-6 102.56 -500 Difluorchlorsilan (germ.) Phosphorus chloride 4335-40-1 104.42 -47.3 difluoride SCF3 Chlorotrifluorosilane 4049-36-6 120.53 -70.2 HCI Hydrogen chloride 7647-01-0 36.46 -85.0 SH3C Chlorosilane 3465-78-6 66.56 -303 CO Carbon monoxide 630-08-0 28.01 -1915 CO2 Carbon dioxide 24-38-9 44.01 -78.4 OCS Carbonyl sulfide 463-58-1 60.07 -50.3 NHF2 Difluoramine O405-27-3 53.01 -23.2 FNNF trans-Difluorodiazine 3776-62-O 66.01 -111.5 FNNF cis-Difluorodiazine 3812-43-6 66.01 -105.8 F2SO Thionyl fluoride 7783-42-8 86.06 -43.8 US 2008/O 135817 A1 Jun. 12, 2008 14

TABLE 1-continued

Dielectric Compound Structure Name CAS MW SHF3 Trifluorosilane 13465-71-9 86.09 -95.2 NF3 Nitrogen trifluoride 7783-54-2 71.OO -129.1 NOF3 Trifluoramine oxide 13847-6S-9 87.00 -87.5 NSF3 thiazyl trifluoride 15930-75-3 103.07 -27.1 PF3 Phosphorus trifluoride 7783-55-3 87.97 -101.5 GeF4 Germanium(IV) fluoride 7783-58-6 148.58 -36.5 SF4 Tetrafluorosilane 7783-61-1 104.08 -86.0 PF5 Phosphorus pentafluoride 7647-19-0 125.97 -84.5 SeF6 Selenium hexafluoride 7783-79-1 192.95 -46.5 TeF6 Tellurium hexafluoride 7783-80-4 241.59 -38.8 SH3F fluorosilane 13537-33-2 SO.11 -98.0 Nitrosyl fluoride 7789-25-5 49.00 -59.9 Fluorine nitrate 7789-26-6 81.00 -46.2 Hydrogen sulfide 7783-06-4 34.08 -59.5 Ammonia 7664-41-7 17.03 -33.3 Helium 7440-59-7 4.OO -268.9 HI Hydrogen iodide 10O34-85-2 127.91 -35.6 Krypton 7439-90-9 83.80 -1534 N2 Nitrogen 7727-37-9 28.01 -1958 NNO dinitrogen oxide 10O24-97-2 44.01 -88.5 Ne Neon 7440-01-9 20.18 -246.1 NO Nitrogen oxide 10102-43-9 30.01 -151.8 Xenon 7440-63-3 131.29 -108.1

0125 The preferred dielectric compounds are selected from the group consisting of those set forth in Table 2 below:

TABLE 2

Dielectric Compound Structure Name CAS MW Air Argon 7440-37-1 39.95 -1859 Trifluoroborane 7637-07-2 67.81 -101.2 Hydrogen bromide 10O3S-1O-6 80.91 -66.7 Bromopentafluoroethane 354-55-2 98.92 -21.0 Chlorotrifluoroethene 79-38-9 16.47 -28.4 Trifluoroacetonitrile 353-85-5 95.02 - 68.8 trifluoromethyl isocyanate 460-49-1 11.02 -36.0 trifluoromethylthiocarbonyl fluoride 32.08 -21.0 Trifluorimethylthiocarbonylfluorid (germ.) pentafluoro-nitroso 49.02 -45.7 ethane, Pentafluor-nitroso aethan C (trifluoromethyl-carbonyl)- 32822-49-4 -21.1 difluoro-amine Hexafluoroethane 76-16-4 -78.2 Bis-trifluorimethyl-nitroxid 2154-71-4 -20.0 bis-trifluoromethyl ether 1479–49-8 -59.0 bis(trifluoromethyl)tellurium SS642-42-7 -98.0 bis(trifluoromethyl) 1718-20-3 -53.0 ditelluride N,N-Difluor -38.0 pentafluoraethylamin (germ.) N-Fluor-bis(trifluorimethyl)- 359-62-6 71.02 -37.0 amin (germ.) N-Fluor-N-trifluormethoxy 4217-92-9 87.02 -25.0 perfluorimethylamin (germ.) fluoroformyl cyanide 683-55-6 73.03 -21.0 1-chloro-1-fluoro-ethene, 1 2317-91-1 80.49 Chlor-1-fluor-aethen 1 chloro-1-fluoroethylene CF2-CH2 1,1-Difluoroethene 75-38-7 64.03 -85.7 CHF CHF #trans-1,2-difluoro 1630-78-0 64.03 -53.1 ethenefiti trans-vinylene difluoride? (E)-1,2- difluoroethylene? (E)-1,2- US 2008/O 135817 A1 Jun. 12, 2008 15

TABLE 2-continued

Dielectric Compound Structure Name CAS MW difluoro-ethenefiti trans vinylene fluoride FHC-CHF 1,2-difluoro-ethenefiticist 1691-13-O 64.03 -28.0 vinylene difluoride?/1,2- Difluor-aethen vinylene fluoride CHF CHF #cis-1,2-difluoro 1630-77-9 64.03 -26.0 ethenefiticist-vinylene difluoride? (Z)-1,2- difluoroethylene, f(Z)-1,2- difluoro-ethenefiticist vinylene fluoride C ,1,1,2-Tetrafluoroethane 811-97-2 -26.1 C 1.22-Tetrafluoroethane 359-35-3 -23.0 C Fluoroethene 75-02-5 -72.2 C 1,1-Trifluoroethane 420-46-2 -47.3 Ether, methyl 421-14-7 -24.0 trifluoromethyl Ethene 74-85-1 -103.7 ,1-Difluoroethane 75-37-6 -24.0 Fluoroethane 3S3-36-6 -37.7 Ethane 74-84-O -88.6 fluoro-dimethyl-borane 353-46-8 -44.0 Disiloxane, 1,1,3,3- 63O89-45-2 -39.0 etrafluoro-1,3-dimethyl Trifluoroethene 359-11-5 -510 trifluoroacetaldehyde?/Trifluor 75-90-1 -21.0 acetaldehy Pentafluoroethane 354-33-6 -48.1 Difluoromethyl 3822-68-2 -35.3 trifluoromethyl ether Tris(trifluoromethyl)bismuth S863-80-9 -SS.O etrafluoropropadienefitetrafluoro 461-68-7 -38.0 allene? (1,1,3,3- etrafluoro-1,2-propadiene etrafluorocyclopropene 19721-29-O -20.0 Perfluoropropionyliodid 137741-03-8 -27.0 pentafluoropropionitrile?/ 422-04-8 -350 pentafluoropropiononitrile hexafluorocyclopropane?. 931-91-9 -33.0 Hexafluorcyclopropan. reon-iiCl216 Hexafluoropropylene 116-15-4 SO.O2 -29.6 hexafluoro-1,3dioxolane 21297-65-4 82O2 -22.1 Octafluoropropane 76-19-7 88.02 -36.7 Perfluormethylethylether 665-1 6-7 204.O2 -20.0 1-difluoro 430-64-8 76.05 -21.0 propadiene fallenylidene difluoride? 1,1-difluoro allene 2,3,3,3-tetrafluoro 754-12-1 114.04 -28.3 propene/HFO-1234yf EranSHFO-1234ze 114.04 -19.0 3,3,3-Trifluoropropene 677-21-4 96.OS -25.0 cyclopropene 2781-85-3 40.06 -36.0 Allene 463-49-O 40.06 -34.5 ,1-difluoropropenefit 430-63-7 78.06 -29.0 propenylidene difluoride?/1,1-Difluorpropen methylketene 6004-44-0 56.06 -23.0 CH2CFCH3 2-fluoropropene 1184-60-7 60.07 -24.0 CH2CHCH3 -Propene 115-07-1 42.08 -47.7 DL-2-aminopropanoic acid 302-72-7 89.09 -50.2 3,3,3-trifluoro 661-54-1 94.04 -48.0 propyne? (3,3,3-Trifluor propini?trifluoromethyl ethyne? (3,3,3-trifluoro-1- propyne 1,1,3,3,3-pentafluoro 690-27-7 132.03 -21.0 propenef, 1,1,3,3,3- Pentafluor-propen CF3 CF CFEH ,2,3,3,3-pentafluoro 2252-83-7 132.03 -20.0 propene US 2008/O 135817 A1 Jun. 12, 2008 16

TABLE 2-continued

Dielectric Compound Structure Name CAS MW 1,1,144.4-hexafluoro-2- 692-50-2 62.03 -24.6 butyne 1,144-tetrafluoro-butane 58.05 -81.0 2,3-dione 14.10 -33.0 F3C O Cl Trifluormethylhypochlorit 22082-78-6 20.46 -47.0 CF2C OF Chlor-difluor-methyl 2O614-17-9 20.46 -25.0 hypofluorit N-Chlor-N-fluor 1388O-72-3 37.46 -32.8 trifluorimethylamin (germ.) Chlordifluordifluoraminomethan 13880-71-2 37.46 -28.0 thiocarbonyl difluoride 420-32-6 82.07 -46.0 Thiocarbonyldifluorid (germ.) selenocarbonyl difluoride S4393-39-4 28.97 -28.0 Trifluoroiodomethane 2314-97-8 95.91 -21.8 N-Fluor-difluorimethanimin 338-66-9 83.01 -101.0 (germ.) trifluoro-nitroso 334-99-6 99.01 -86.0 methane, Trifluor-nitroso methan difluoro-carbamoyl fluoride 2368-32-3 99.01 -52.0 trifluoro-nitro 335-02-4 15.01 -33.6 methane, Trifluor-nitro methan fluoropicrin Tetrafluoromethane 75-73-0 88.00 -128.1 Tetrafluorformamidin 14362-70-0 16.O2 -3O.O (germ.) etrafluorourea 10256-92-5 32.O2 -20.0 hypofluorous acid trifluoromethyl -95.0 ester? Hypofluorigsaeure trifluorimethylesteri?trifluoromethylhypofluorite trifluoromethanesulfonyl 335-05-7 52.07 -21.7 fluoride N,N-Difluor 335-01-3 21.01 -7S.O trifluorimethylamin (germ.) CFSNO Trifluormethyloxydifluoramin 4217-93-O 37.01 -59.8 CFSNO2 (Difluoraminoxy)difluorimethyl 36781-60-9 53.01 -29.0 hypofluorit CFSNS SFSCN Sulfurcyanide pentafluoride 1512-13-6 53.08 -25.0 Schwefelcyanid pentafluorid (germ.) CFSP difluoro-trifluoromethyl 1112-04-5 37.98 -43.0 phosphine Hexafluorimethandiamin 4394-93-8 54.O1 -37.0 perfluoro methylsilane 335-06-8 54.09 -42.0 Perfluormethylsilan (germ.) Trifluormethyl 1184-81-2 75.97 -350 etrafluorphosphoran (germ.) Difluoromethane 75-10-5 S2.O2 -51.7 Fluoroiodomethane 373-53-5 59.93 -53.8 fluoromethanet methyl 593-53-3 34.03 -78.3 fluoride, Fluormethan reon-41 C trifluoromethyl-silane' 1O112-11-5 OO.12 -383 CF3SH3 methyltrifluorosilane 373-74-0 OO.12 -3O.O difluoro-methyl-silane 420-34-8 82.12 -35.6 fluoro-methyl-silane 753-44-6 64.13 -44.0 methylgermane 1449-65-6 90.65 -23.0 Difluorformimin 2712-98-3 6S.O2 -22.0 Trifluoromethane 75-46-7 70.01 -82.1 trifluoromethane thiol 1493-15-8 102.08 -36.7 Trifluormethanthiol (germ.) C N,N,1,1- 24708-53-0 103.02 -43.0 Tetrafluormethylamin difluoro dichlorosilane 18356-71-3 136.99 -31.8 Difluordichlorsilan (germ.) difluoro chlorosilane 8OOO3-43-6 102.56 -500 Difluorchlorsilan (germ.) Phosphorus chloride 14335-40-1 104.42 -47.3 difluoride US 2008/O 135817 A1 Jun. 12, 2008 17

TABLE 2-continued

Dielectric MY Compound Structure Name CAS MW BP(° C.) CF3S SCF3 Chlorotrifluorosilane 14049-36-6 120.53 -702 CH HCI Hydrogen chloride 7647-01-0 36.46 -85.0 CH3S SH3C Chlorosilane 13465-78-6 66.56 -30.3 CO CO Carbon monoxide 630-08-0 28.01 -1915 CO2 CO2 Carbon dioxide 124-38-9 44.01 -78.4 COS OCS Carbonyl sulfide 463-58-1 60.07 -SO3 F2HN NHF2 Difluoramine 1040S-27-3 53.01 -23.2 F2N2 FNNF trans-Difluorodiazine 13776-62-0 66.01 -111.5 F2N2 FNNF cis-Difluorodiazine 13812-43-6 66.01 -105.8 F2OS F2SO Thionyl fluoride 7783-42-8 86.06 -43.8 F3HS SHF3 Trifluorosilane 13465-71-9 86.09 -95.2 F3N NF3 Nitrogen trifluoride 7783-54-2 71.OO -129.1 F3NO NOF3 Trifluoramine oxide 13847-6S-9 87.00 -87.5 F3NS NSF3 thiazyl trifluoride 15930-7S-3 103.07 -27.1 F3P PF3 Phosphorus trifluoride 7783-55-3 87.97 -101.5 F4Ge GeF4 Germanium(IV) fluoride 7783-58-6 148.58 -36.5 F4S. SF Tetrafluorosilane 7783-61-1 104.08 -86.0 PF5 Phosphorus pentafluoride 7647-19-0 125.97 -84.5 F6Se SeF6 Selenium hexafluoride 7783-79-1 192.95 -46.5 F6Te TeF6 Tellurium hexafluoride 7783-80-4 241.59 -38.8 FH3S SH3F fluorosilane 13537-33-2 50.11 -98.0 FNO Nitrosyl fluoride 7789-25-5 49.00 -59.9 FNO3 Fluorine nitrate 7789-26-6 81.00 -46.2 H2S H2S Hydrogen sulfide 7783-06-4 34.08 -59.5 H3N NH3 Ammonia 7664-41-7 17.03 -33.3 He He Helium 7440-59-7 4.00 -268.9 HI H Hydrogen iodide 10O34-85-2 127.91 -35.6 Kr Kr Krypton 7439-90-9 83.80 -1534 N2 N2 Nitrogen 7727-37-9 28.01 - 1958 N2O NON Nitrous oxide 10O24-97-2 44.01 -88.5 Ne Ne Neon 7440-01-9 20.18 -246.1 NO NO Nitrogen oxide 10102-43-9 3O.O1 -151.8 Xe Xe Xenon 7440-63-3 131.29 -108.1

0126 The aforementioned dielectric compounds may be EXAMPLE 1. used in pure form, but can also be used as part of an azeotrope, or a mixture with an appropriate second gas, i.e., nitrogen, 0.138 Measurements of the dielectric strength of potential CO, or N.O. alternatives were determined using ASTM D2477 or obtained 0127 Particularly preferred non-electrical properties for from literature. These measurements were performed at 1 dielectric gases according to the present disclosure, include: atmosphere pressure across a 0.1 inch gap and at ambient 0128 Non-liquefying, e.g., T. less than -20°C. temperature. I0129. Chemically stable—decomposition temperature 0.139. In the intended applications, the gas will not be at 1 must be higher than hot spot temperature in equipment, atmosphere pressure but at a higher pressure. In this example e.g., T 200° C., and gas should not decompose in 5 atmospheres pressure is used as a maximum pressure. If the partial discharge spark (approximately 1000 K) gas liquefies at a lower pressure than that pressure was used. 0.130 Low environmental impact, i.e., little to no These gases have higher dielectric strengths and break down destruction of ozone layer ODP=0; and low global Voltages than air. Using 5 atmospheres (73.5 psia) pressure as warming impact GWP less than SF the upper pressure (rating of the equipment). I0131. Acceptably low toxicity of gas and discharge byproducts 0132 Electrical equipment property requirements for Breakdown voltage at dielectric gases according to the present disclosure, include: Dielectric strength Pressure maximum pressure 0.133 Insulation specific criteria include a critical field Gas kVO.1 inch gap (psia) (kVO.1 inch gap) of E, and no conducting decomposition products Air 4.75 73.5 23.75 should be generated by discharge R143a 5.8 73.5 29 0.134 Switching specific criteria include high critical R152a. 5.9 73.5 29.5 field of E, arcing stability, i.e., a gas must recombine to R12S 6.4 73.5 32 R134a 6.6 73.5 33 original molecular structure after being decomposed in R22 7.2 73.5 39.9 switching arc (Gibbs free energy of reaction is <0) R124 10.4 55.5 39.3 0.135 Specific thermal interruption performance, i.e., SF6 14.O 73.5 70 C318 16.O 45.3 49.3 must be able to interrupt current flow at accurrent Zero R115 16.O 73.6 8O 0.136 Arc erosion product from equipment and gas R114 17.0 31.1 36 must not form conduction deposits I0137 Low velocity of sound US 2008/O 135817 A1 Jun. 12, 2008

EXAMPLE 2 Ethinylsilan ethyl-difluor-borane 0140. The dielectric strength of additional gases is mea Ethyl-difluor-boran (germ.) Sure at 1 atmosphere and at the maximum system pressure. methyl-methylen-amine Their breakdown voltages are found to be greater then air, Dimethyl ether which allows Smaller gaps and therefore Smaller equipment vinyl-silane then would be need if air was used. Here the measurements Dimethylsilane were performed on CTFE (Chlorotrifluoroethylene), HCl Chloroethyne (hydrogen chloride) and SiF4 (silicon tetrafluoride). fluoroethyne/fluoro-acetylene 0141 Having described the invention in detail by refer Ethanedinitrile ence to the preferred embodiments and specific examples tetrafluoropropyne?/1,3,3,3-tetrafluoropropyne thereof, it will be apparent that modifications and variations hexafluoro-oxetane are possible without departing from the spirit and scope of the Trifluoro(trifluoromethyl)oxirane disclosure and claims. 1,1,1,3,3,3-Hexafluoropropanone What is claimed is: pentafluoro-propionyl fluoride/perfluoropropionyl fluo 1. A dielectric gaseous compound which exhibits the fol ride lowing properties: Trifluoromethyl trifluorovinyl ether a boiling point in the range between about -20°C. to about 1-Propyne -273° C.; Cyclopropane low non-oZone depleting: Propane a GWP less than about 22,200; Trimethylborane chemical stability, as measured by a negative standard cyanoketene enthalpy of formation (dHf-0); butatriene a toxicity level such that when the dielectric gas leaks, the Cyano-bispentafluorethyl-phosphin effective diluted concentration does not exceed its PEL Trimethyl-1,1,2,2-tetrafluorethylsilan in the working environment; and a dielectric strength greater than air. methyl diborane 2. The dielectric gaseous compound according to claim 1, Methyldiboran (germ.) wherein said dielectric gaseous compound is at least one carbonyl bromide fluoride compound selected from the group consisting of: chloro-difluoro-nitroso-methane?/Chlor-difluor-nitroso Arsenic pentafluoride methan Arsine chloroperoxytrifluoromethane Diboron tetrafluoride carbonylchlorid-fluorid Diborane Carbonychlorid fluorid (germ.) Perchloric acid, 2-chloro-1,1,2,2-tetrafluoroethyl ester 3,3-difluoro-3HH-diazirine (9CI) difluoro diazomethane Perchloric acid, 1.2.2-trichloro-1,2-difluoroethyl ester Difluordiazomethan (germ.) Trifluoroacetyl chloride Carbonyl fluoride trifluoromethylisocyanide (CF3-NC) Difluordioxiran trifluoromethyl isocyanide difluoro-(3-fluoro-3#H!-diazirin-3-yl)-amine trifluoro-nitroso-ethene?/Trifluor-nitroso-aethen trifluoromethylazide Tetrafluoroethene Trifluormethylazid (germ.) tetrafluoro-diaziridine 3,3,4,4-tetrafluoro-3,4-dihydro-1,2diazete Fluorperoxytrifluorimethan (Difluoramino)difluoracetonitril Bis(fluoroxy)difluormethan Tetrafluorooxirane Trifluormethyl-phosphonylfluorid Trifluoroacetyl fluoride Cyanogen fluoride Perfluorimethylfluorformiat Trifluorimethylphosphane (germ.) trifluoro-acetyl hypofluorite Diazomethane perfluoro-2-aza-1-propene formaldehyde/Formalin Perfluor-2-aza-1-propen (germ.) (methyl)difluoroborane N-Fluor-tetrafluor-1-aethanimin (germ.) 3.3-difluoro-2-trifluoromethyl-oxaziridine (Methyl)difluorboran (germ.) bis-trifluoromethyl-diazene/hexafluoro-icis Chloromethane aZomethane methylphosphonous acid difluoride/difluoro-methyl Fluoroxypentafluoroethane phosphine bis-trifluoromethyl peroxide trifluoro-methoxy-silane 1,1-Bis(fluoroxy)tetrafluoroaethan Methylhypofluorid Hexafluorodimethyl sulfide Methane 3-fluoro-3HH-diazirine-3-carbonitrile Methylsilane Ethyne #Si-bromo-it-Sili Si'-methanediyl-bis-silane 1,2,2-trifluoro-aziridine #Si-iodo-it-Sili Si'-methanediyl-bis-silane Ketene Difluormethylnitrit (difluoro)vinylboran trifluoromethanol (Difluor) vinylboran (germ.) Formyl fluoride trifluoro-vinyl-silane Cyanic acid US 2008/O 135817 A1 Jun. 12, 2008 19

Chlorine Ether, methyl trifluoromethyl Chlorine fluoride Ethene Chlorine trioxide fluoride 1,1-Difluoroethane carbon oxide selenide/Kohlenoxidselenid Fluoroethane Fluorine Ethane Difluorosilane fluoro-dimethyl-borane Fluorine oxide Disiloxane, 1,1,3,3-tetrafluoro-1,3-dimethyl-Trifluoroet fluorine peroxide hene Sulfinuryl fluoride trifluoroacetaldehyde?/Trifluor-acetaldehyd sulphur difluoride Pentafluoroethane Phosphorus trifluoride oxide Difluoromethyl trifluoromethyl ether Phosphorus trifluoride sulfide Tris(trifluoromethyl)bismuth tetrafluorophosphorane tetrafluoropropadiene/tetrafluoro-allene?/1,1,3,3-tet Tetrafluorohydrazine rafluoro-1,2-propadiene Sulfur tetrafluoride tetrafluorocyclopropene hexafluoro disiloxane Perfluoropropionyliodid Hexafluordisiloxan (germ.) pentafluoro-propionitrile?/pentafluoropropiononitrile Nitryl fluoride hexafluoro-cyclopropane?/Hexafluor-cyclopropan//freon Hydrogen HCl216 Hydrogen selenide Hexafluoropropylene Phosphorus trihydride hexafluoro-1,3dioxolane Germanium hydride Octafluoropropane Silane Perfluormethylethylether Tin tetrahydride 1,1-difluoro-propadiene/allenylidene difluoride?/1,1-dif Oxygen luoro-allene OZone 2,3,3,3-tetrafluoro-propene/HFO-1234yf Antimony monophosphide trans. HFO-1234ze Disilicon monophosphide 3,3,3-Trifluoropropene Radon cyclopropene Argon Allene Trifluoroborane 1,1-difluoro-propene/propenylidene difluoride?/1,1-Dif Hydrogen bromide luor-propen Bromopentafluoroethane methylketene Chlorotrifluoroethene 2-fluoropropene Trifluoroacetonitrile 1-Propene trifluoromethyl isocyanate DL-2-aminopropanoic acid trifluoromethylthiocarbonyl fluoride 3,3,3-trifluoro-propyne/3.3.3-Trifluor-propin/trifluo Trifluormethylthiocarbonylfluorid (germ.) romethyl-ethyne/3,3,3-trifluoro-1-propyne pentafluoro-nitroso-ethane//Pentafluor-nitroso-aethan 1,1,3,3,3-pentafluoro-propene/1,1,3,3,3-Pentafluor-pro (trifluoromethyl-carbonyl)-difluoro-amine pen 1.2.3,3,3-pentafluoro-propene Hexafluoroethane 1.1.1.4.4.4-hexafluoro-2-butyne Bis-trifluormethyl-nitroxid 1,1,4,4-tetrafluoro-butane-2,3-dione bis-trifluoromethyl ether Trifluormethylhypochlorit bis(trifluoromethyl)tellurium Chlor-difluor-methyl-hypofluorit bis(trifluoromethyl)ditelluride N-Chlor-N-fluor-trifluorimethylamin (germ.) N,N-Difluor-pentafluoraethylamin (germ.) Chlordifluordifluoraminomethan N-Fluor-bis(trifluorimethyl)-amin (germ.) thiocarbonyl difluoride N-Fluor-N-trifluorimethoxy-perfluormethylamin (germ.) Thiocarbonyldifluorid (germ.) fluoroformyl cyanide selenocarbonyl difluoride 1-chloro-1-fluoro-ethene/71-Chlor-1-fluor-aethen/71 Trifluoroiodomethane chloro-1-fluoroethylene N-Fluor-difluorimethanimin (germ.) 1,1-Difluoroethene trifluoro-nitroso-methane/Trifluor-nitroso-methan itrans-1,2-difluoro-ethene/#trans-vinylene difluoride/ difluoro-carbamoyl fluoride (E)-1,2-difluoroethylene/7(E)-1,2-difluoro-ethene/ trifluoro-nitro-methane/Trifluor-nitro-methan//fluoropi itrans-vinylene fluoride crin 1,2-difluoro-ethene//icis-Vinylene difluoride?/1,2-Dif Tetrafluoromethane luor-aethen//vinylene fluoride Tetrafluorformamidin (germ.) icis-1,2-difluoro-ethene/icis-Vinylene difluoride//(Z)- tetrafluorourea 1,2-difluoroethylene/(Z)-1,2-difluoro-ethene/icis hypofluorous acid trifluoromethyl ester//Hypofluorigsae vinylene fluoride ure-trifluormethylester//trifluoromethyl hypofluorite 1,1,1,2-Tetrafluoroethane trifluoromethanesulfonyl fluoride 1,1,2,2-Tetrafluoroethane N,N-Difluor-trifluorimethylamin (germ.) Fluoroethene Trifluormethyloxydifluoramin 1,1,1-Trifluoroethane (Difluoraminoxy)difluorimethylhypofluorit US 2008/O 135817 A1 Jun. 12, 2008 20

sulfurcyanide pentafluoride Bromopentafluoroethane Schwefelcyanid-pentafluorid (germ.) Chlorotrifluoroethene difluoro-trifluoromethyl-phosphine Trifluoroacetonitrile Hexafluorimethandiamin trifluoromethyl isocyanate perfluoro methylsilane trifluoromethyl thiocarbonyl fluoride Perfluorimethylsilan (germ.) Trifluormethylthiocarbonylfluorid (germ.) Trifluormethyl-tetrafluorphosphoran (germ.) pentafluoro-nitroso-ethane//Pentafluor-nitroso-aethan Difluoromethane (trifluoromethyl-carbonyl)-difluoro-amine Fluoroiodomethane Hexafluoroethane fluoromethane/methyl fluoride/Fluor-methan//freon-41 Bis-trifluorimethyl-nitroxid trifluoromethyl-silane” CF3SiH3 bis-trifluoromethyl ether methyltrifluorosilane bis(trifluoromethyl)tellurium difluoro-methyl-silane bis(trifluoromethyl)ditelluride fluoro-methyl-silane N,N-Difluor-pentafluoraethylamin (germ.) methyl germane N-Fluor-bis(trifluormethyl)-amin (germ.) Difluorformimin N-Fluor-N-trifluorimethoxy-perfluormethylamin (germ.) Trifluoromethane fluoroformyl cyanide trifluoromethane thiol 1-chloro-1-fluoro-ethene/71-Chlor-1-fluor-aethen/71 Trifluormethanthiol (germ.) chloro-1-fluoroethylene N.N.,1,1-Tetrafluormethylamin 1,1-Difluoroethene difluoro dichlorosilane itrans-1,2-difluoro-ethene/#trans-vinylene difluoride/ Difluordichlorsilan (germ.) (E)-1,2-difluoroethylene/7(E)-1,2-difluoro-ethene/ difluoro chlorosilane itrans-vinylene fluoride Difluorchlorsilan (germ.) 1,2-difluoro-ethene/icis-vinylene difluoride?/1,2-Dif Phosphorus chloride difluoride luor-aethen//vinylene fluoride Chlorotrifluorosilane icis-1,2-difluoro-ethene//icis-Vinylene difluoride//(Z)- Hydrogen chloride 1,2-difluoroethylene/(Z)-1,2-difluoro-ethene/icis Chlorosilane vinylene fluoride Carbon monoxide 1,1,1,2-Tetrafluoroethane Carbon dioxide 1,1,2,2-Tetrafluoroethane Carbonyl sulfide Fluoroethene Difluoramine 1,1,1-Trifluoroethane trans-Difluorodiazine Ether, methyl trifluoromethyl cis-Difluorodiazine Ethene Thionyl fluoride 1,1-Difluoroethane Trifluorosilane Fluoroethane Nitrogen trifluoride Ethane Trifluoramine oxide fluoro-dimethyl-borane thiazyl trifluoride Disiloxane, 1,1,3,3-tetrafluoro-1,3-dimethyl-Trifluoroet Phosphorus trifluoride hene Germanium(IV) fluoride trifluoroacetaldehyde?/Trifluor-acetaldehyd Tetrafluorosilane Pentafluoroethane Phosphorus pentafluoride Difluoromethyl trifluoromethyl ether Selenium hexafluoride Tris(trifluoromethyl)bismuth Tellurium hexafluoride tetrafluoropropadiene/tetrafluoro-allene?/1,1,3,3-tet fluorosilane rafluoro-1,2-propadiene Nitrosyl fluoride tetrafluorocyclopropene Fluorine nitrate Perfluoropropionyliodid Hydrogen sulfide pentafluoro-propionitrile?/pentafluoropropiononitrile Ammonia hexafluoro-cyclopropane?/Hexafluor-cyclopropan//freon Helium HCl216 Hydrogen iodide Hexafluoropropylene Krypton hexafluoro-1,3dioxolane Nitrogen Octafluoropropane dinitrogen oxide Perfluormethylethylether Neon 1,1-difluoro-propadiene/allenylidene difluoride?/1,1-dif Nitrogen oxide; and luoro-allene Xenon 2,3,3,3-tetrafluoro-propene/HFO-1234yf 3. The dielectric gaseous compound according to claim 2, trans. HFO-1234ze wherein said dielectric gaseous compound is at least one 3,3,3-Trifluoropropene compound selected from the group consisting of cyclopropene Argon Allene Trifluoroborane 1,1-difluoro-propene/propenylidene difluoride?/1,1-Dif Hydrogen bromide luor-propen US 2008/O 135817 A1 Jun. 12, 2008 21

methylketene Difluoramine 2-fluoropropene trans-Difluorodiazine 1-Propene cis-Difluorodiazine DL-2-aminopropanoic acid Thionyl fluoride 3,3,3-trifluoro-propyne/3.3.3-Trifluor-propin/trifluo Trifluorosilane romethyl-ethyne/3,3,3-trifluoro-1-propyne Nitrogen trifluoride 1,1,3,3,3-pentafluoro-propenef/1.1.3.3.3-Pentafluor-pro Trifluoramine oxide pen thiazyl trifluoride 1,2,3,3,3-pentafluoro-propene Phosphorus trifluoride 1.1.1.4.4.4-hexafluoro-2-butyne Germanium(IV) fluoride 1,1,4,4-tetrafluoro-butane-2,3-dione Tetrafluorosilane Trifluormethylhypochlorit Phosphorus pentafluoride Chlor-difluor-methyl-hypofluorit Selenium hexafluoride N-Chlor-N-fluor-trifluorimethylamin (germ.) Tellurium hexafluoride Chlordifluordifluoraminomethan fluorosilane thiocarbonyl difluoride Nitrosyl fluoride Thiocarbonyldifluorid (germ.) Fluorine nitrate selenocarbonyl difluoride Hydrogen sulfide Trifluoroiodomethane Ammonia N-Fluor-difluorimethanimin (germ.) Helium trifluoro-nitroso-methane?/Trifluor-nitroso-methan Hydrogen iodide difluoro-carbamoyl fluoride Krypton trifluoro-nitro-methane/Trifluor-nitro-methan//fluoropi Nitrogen crin Nitrous oxide Tetrafluoromethane Neon Tetrafluorformamidin (germ.) Nitrogen oxide; and tetrafluorourea Xenon hypofluorous acid trifluoromethyl ester//Hypofluorigsae 4. The dielectric gaseous compound according to claim 1, ure-trifluormethylester//trifluoromethyl hypofluorite further comprising forming an azeotrope of said dielectric trifluoromethanesulfonyl fluoride gaseous compound. N,N-Difluor-trifluorimethylamin (germ.) 5. The dielectric gaseous compound according to claim 1, Trifluormethyloxydifluoramin further comprising admixing said dielectric gaseous com (Difluoraminoxy)difluorimethylhypofluorit pound with at least one gas selected from the group consisting sulfurcyanide pentafluoride of nitrogen, CO and N.O. Schwefelcyanid-pentafluorid (germ.) 6. An insulation-gas for use in electrical equipment, difluoro-trifluoromethyl-phosphine wherein said insulation-gas is a dielectric gaseous compound Hexafluorimethandiamin which exhibits the following properties: perfluoro methylsilane a boiling point in the range between about -20°C. to about Perfluorimethylsilan (germ.) -273° C.; Trifluormethyl-tetrafluorphosphoran (germ.) low non-oZone depleting: Difluoromethane a GWP less than about 22,200; Fluoroiodomethane chemical stability, as measured by a negative standard fluoromethane/methyl fluoride/Fluor-methan//freon-41 enthalpy of formation (dHf-0); trifluoromethyl-silane” CF3SiH3 a toxicity level such that when the dielectric gas leaks, the methyltrifluorosilane effective diluted concentration does not exceed its PEL; difluoro-methyl-silane and fluoro-methyl-silane a dielectric strength greater than air. methyl germane 7. The insulation-gas according to claim 6, wherein said Difluorformimin dielectric gaseous compound is at least one compound Trifluoromethane selected from the group consisting of: trifluoromethane thiol Arsenic pentafluoride Trifluormethanthiol (germ.) Arsine N.N.,1,1-Tetrafluormethylamin Diboron tetrafluoride difluoro dichlorosilane Diborane Difluordichlorsilan (germ.) Perchloric acid, 2-chloro-1,1,2,2-tetrafluoroethyl ester difluoro chlorosilane (9CI) Difluorchlorsilan (germ.) Perchloric acid, 1.2.2-trichloro-1,2-difluoroethyl ester Phosphorus chloride difluoride Trifluoroacetyl chloride Chlorotrifluorosilane trifluoromethylisocyanide (CF3-NC) Hydrogen chloride trifluoromethyl isocyanide Chlorosilane trifluoro-nitroso-ethene?/Trifluor-nitroso-aethen Carbon monoxide Tetrafluoroethene Carbon dioxide 3,3,4,4-tetrafluoro-3,4-dihydro-1,2diazete Carbonyl sulfide (Difluoramino)difluoracetonitril US 2008/O 135817 A1 Jun. 12, 2008 22

Tetrafluorooxirane Bis(fluoroxy)difluormethan Trifluoroacetyl fluoride Trifluormethyl-phosphonylfluorid Perfluorimethylfluorformiat Cyanogen fluoride trifluoro-acetyl hypofluorite Trifluorimethylphosphane (germ.) perfluoro-2-aza-1-propene Diazomethane Perfluor-2-aza-1-propen (germ.) formaldehyde/Formalin N-Fluor-tetrafluor-1-aethanimin (germ.) (methyl)difluoroborane 3.3-difluoro-2-trifluoromethyl-oxaziridine (Methyl)difluorboran (germ.) bis-trifluoromethyl-diazene/hexafluoro-icis- Chloromethane aZomethane methylphosphonous acid difluoride/difluoro-methyl Fluoroxypentafluoroethane phosphine bis-trifluoromethyl peroxide trifluoro-methoxy-silane 1,1-Bis(fluoroxy)tetrafluoroaethan Methylhypofluorid Hexafluorodimethyl sulfide Methane 3-fluoro-3HH-diazirine-3-carbonitrile Methylsilane Ethyne #Si-bromo-it-Sili Si'-methanediyl-bis-silane 1,2,2-trifluoro-aziridine #Si-iodo-it-Sili Si'-methanediyl-bis-silane Ketene Difluormethylnitrit (difluoro)vinylboran trifluoromethanol (Difluor) vinylboran (germ.) Formyl fluoride trifluoro-vinyl-silane Cyanic acid Ethinylsilan Chlorine ethyl-difluor-borane Chlorine fluoride Ethyl-difluor-boran (germ.) Chlorine trioxide fluoride methyl-methylen-amine carbon oxide selenide/Kohlenoxidselenid Dimethyl ether Fluorine vinyl-silane Difluorosilane Dimethylsilane Fluorine oxide Chloroethyne fluorine peroxide fluoroethyne/fluoro-acetylene Sulfinuryl fluoride Ethanedinitrile sulphur difluoride tetrafluoropropyne/1,3,3,3-tetrafluoropropyne Phosphorus trifluoride oxide hexafluoro-oxetane Phosphorus trifluoride sulfide Trifluoro(trifluoromethyl)oxirane tetrafluorophosphorane 1,1,1,3,3,3-Hexafluoropropanone Tetrafluorohydrazine pentafluoro-propionyl fluoride/perfluoropropionyl fluo- Sulfur tetrafluoride ride hexafluoro disiloxane Trifluoromethyl trifluorovinyl ether Hexafluordisiloxan (germ.) 1-Propyne Nitryl fluoride Cyclopropane Hydrogen Propane Hydrogen selenide Trimethylborane Phosphorus trihydride cyanoketene Germanium hydride butatriene Silane Cyano-bispentafluorethyl-phosphin Tin tetrahydride Trimethyl-1,1,2,2-tetrafluorethylsilan Oxygen methyl diborane OZone Methyldiboran (germ.) Antimony monophosphide carbonyl bromide fluoride Disilicon monophosphide chloro-difluoro-nitroso-methane?/Chlor-difluor-nitroso- Radon methan Argon chloroperoxytrifluoromethane Trifluoroborane carbonylchlorid-fluorid Hydrogen bromide Carbonychlorid fluorid (germ.) Bromopentafluoroethane 3,3-difluoro-3HH-diazirine Chlorotrifluoroethene difluoro diazomethane Trifluoroacetonitrile Difluordiazomethan (germ.) trifluoromethyl isocyanate Carbonyl fluoride trifluoromethyl thiocarbonyl fluoride Difluordioxiran Trifluormethylthiocarbonylfluorid (germ.) difluoro-(3-fluoro-3#H!-diazirin-3-yl)-amine pentafluoro-nitroso-ethane//Pentafluor-nitroso-aethan trifluoromethylazide (trifluoromethyl-carbonyl)-difluoro-amine Trifluormethylazid (germ.) Hexafluoroethane tetrafluoro-diaziridine Bis-trifluorimethyl-nitroxid Fluorperoxytrifluorimethan bis-trifluoromethyl ether US 2008/O 135817 A1 Jun. 12, 2008 23

bis(trifluoromethyl)tellurium Chlor-difluor-methyl-hypofluorit bis(trifluoromethyl)ditelluride N-Chlor-N-fluor-trifluorimethylamin (germ.) N,N-Difluor-pentafluoraethylamin (germ.) Chlordifluordifluoraminomethan N-Fluor-bis(trifluorimethyl)-amin (germ.) thiocarbonyl difluoride N-Fluor-N-trifluornethoxy-perfluorimethylamin (germ.) Thiocarbonyldifluorid (germ.) fluoroformyl cyanide selenocarbonyl difluoride 1-chloro-1-fluoro-ethene/71-Chlor-1-fluor-aethen/71 Trifluoroiodomethane chloro-1-fluoroethylene 1,1-Difluoroethene N-Fluor-difluorimethanimin (germ.) itrans-1,2-difluoro-ethene/#trans-vinylene difluoride/ trifluoro-nitroso-methane/Trifluor-nitroso-methan (E)-1,2-difluoroethylene/7(E)-1,2-difluoro-ethene/ difluoro-carbamoyl fluoride itrans-vinylene fluoride trifluoro-nitro-methane/Trifluor-nitro-methan//fluoropi 1,2-difluoro-ethene//icis-Vinylene difluoride?/1,2-Dif crin luor-aethen//vinylene fluoride Tetrafluoromethane icis-1,2-difluoro-ethene/icis-Vinylene difluoride//(Z)- Tetrafluorformamidin (germ.) 1,2-difluoroethylene/(Z)-1,2-difluoro-ethene/icis tetrafluorourea vinylene fluoride hypofluorous acid trifluoromethyl ester//Hypofluorigsae 1,1,1,2-Tetrafluoroethane ure-trifluormethylester//trifluoromethyl hypofluorite 1,1,2,2-Tetrafluoroethane trifluoromethanesulfonyl fluoride Fluoroethene N,N-Difluor-trifluorimethylamin (germ.) 1,1,1-Trifluoroethane Trifluormethyloxydifluoramin Ether, methyl trifluoromethyl (Difluoraminoxy)difluorimethylhypofluorit Ethene sulfurcyanide pentafluoride 1,1-Difluoroethane Schwefelcyanid-pentafluorid (germ.) Fluoroethane difluoro-trifluoromethyl-phosphine Ethane Hexafluormethandiamin fluoro-dimethyl-borane perfluoro methylsilane Disiloxane, 1,1,3,3-tetrafluoro-1,3-dimethyl-Trifluoroet Perfluorimethylsilan (germ.) hene Trifluormethyl-tetrafluorphosphoran (germ.) trifluoroacetaldehyde?/Trifluor-acetaldehyd Difluoromethane Pentafluoroethane Fluoroiodomethane Difluoromethyl trifluoromethyl ether fluoromethane/methyl fluoride/Fluor-methan//freon-41 Tris(trifluoromethyl)bismuth trifluoromethyl-silane” CF3SiH3 tetrafluoropropadiene/tetrafluoro-allene?/1,1,3,3-tet methyltrifluorosilane rafluoro-1,2-propadiene difluoro-methyl-silane tetrafluorocyclopropene fluoro-methyl-silane Perfluoropropionyliodid methylgermane pentafluoro-propionitrile?/pentafluoropropiononitrile Difluorformimin hexafluoro-cyclopropane?/Hexafluor-cyclopropan// Trifluoromethane freon-HCl216 trifluoromethane thiol Hexafluoropropylene Trifluormethanthiol (germ.) hexafluoro-1,3dioxolane N.N.,1,1-Tetrafluorimethylamin Octafluoropropane difluoro dichlorosilane Perfluormethylethylether Difluordichlorsilan (germ.) 1,1-difluoro-propadiene/allenylidene difluoride?/1,1-dif difluoro chlorosilane luoro-allene Difluorchlorsilan (germ.) 2,3,3,3-tetrafluoro-propene/HFO-1234yf Phosphorus chloride difluoride trans. HFO-1234ze Chlorotrifluorosilane 3,3,3-Trifluoropropene Hydrogen chloride cyclopropene Chlorosilane Allene Carbon monoxide 1,1-difluoro-propene/propenylidene difluoride?/1,1-Dif Carbon dioxide luor-propen Carbonyl sulfide methylketene Difluoramine 2-fluoropropene trans-Difluorodiazine 1-Propene cis-Difluorodiazine DL-2-aminopropanoic acid Thionyl fluoride 3,3,3-trifluoro-propyne/3.3.3-Trifluor-propin/trifluo Trifluorosilane romethyl-ethyne/3,3,3-trifluoro-1-propyne Nitrogen trifluoride 1,1,3,3,3-pentafluoro-propenef/1.1.3.3.3-Pentafluor-pro Trifluoramine oxide pen thiazyl trifluoride 1,2,3,3,3-pentafluoro-propene Phosphorus trifluoride 1.1.1.4.4.4-hexafluoro-2-butyne Germanium(IV) fluoride 1,1,4,4-tetrafluoro-butane-2,3-dione Tetrafluorosilane Trifluormethylhypochlorit Phosphorus pentafluoride US 2008/O 135817 A1 Jun. 12, 2008 24

Selenium hexafluoride Tris(trifluoromethyl)bismuth Tellurium hexafluoride tetrafluoropropadiene/tetrafluoro-allene?/1,1,3,3-tet fluorosilane rafluoro-1,2-propadiene Nitrosyl fluoride tetrafluorocyclopropene Fluorine nitrate Perfluoropropionyliodid Hydrogen sulfide pentafluoro-propionitrile?/pentafluoropropiononitrile Ammonia hexafluoro-cyclopropane?/Hexafluor-cyclopropan//freon Helium HCl216 Hydrogen iodide Hexafluoropropylene Krypton hexafluoro-1,3dioxolane Nitrogen Octafluoropropane dinitrogen oxide Perfluormethylethylether Neon 1,1-difluoro-propadiene/allenylidene difluoride?/1,1-dif Nitrogen oxide; and luoro-allene Xenon 2,3,3,3-tetrafluoro-propene/HFO-1234yf 8. The insulation-gas according to claim 7, wherein said trans. HFO-1234ze dielectric gaseous compound is at least one compound 3,3,3-Trifluoropropene selected from the group consisting of: cyclopropene Argon Allene Trifluoroborane 1,1-difluoro-propene/propenylidene difluoride?/1,1-Dif Hydrogen bromide luor-propen Bromopentafluoroethane methylketene Chlorotrifluoroethene 2-fluoropropene Trifluoroacetonitrile 1-Propene trifluoromethyl isocyanate DL-2-aminopropanoic acid trifluoromethylthiocarbonyl fluoride 3,3,3-trifluoro-propyne/3.3.3-Trifluor-propin/trifluorom Trifluormethylthiocarbonylfluorid (germ.) ethyl-ethyne/3,3,3-trifluoro-1-propyne pentafluoro-nitroso-ethane//Pentafluor-nitroso-aethan 1,1,3,3,3-pentafluoro-propene/1,1,3,3,3-Pentafluor-pro (trifluoromethyl-carbonyl)-difluoro-amine pen Hexafluoroethane 1.2.3,3,3-pentafluoro-propene Bis-trifluormethyl-nitroxid 1.1.1.4.4.4-hexafluoro-2-butyne bis-trifluoromethyl ether 1,1,4,4-tetrafluoro-butane-2,3-dione bis(trifluoromethyl)tellurium Trifluormethylhypochlorit bis(trifluoromethyl)ditelluride Chlor-difluor-methyl-hypofluorit N,N-Difluor-pentafluoraethylamin (germ.) N-Chlor-N-fluor-trifluorimethylamin (germ.) N-Fluor-bis(trifluorimethyl)-amin (germ.) Chlordifluordifluoraminomethan N-Fluor-N-trifluorimethoxy-perfluormethylamin (germ.) thiocarbonyl difluoride fluoroformyl cyanide Thiocarbonyldifluorid (germ.) 1-chloro-1-fluoro-ethene/71-Chlor-1-fluor-aethen/71 selenocarbonyl difluoride chloro-1-fluoroethylene Trifluoroiodomethane 1,1-Difluoroethene N-Fluor-difluorimethanimin (germ.) itrans-1,2-difluoro-ethene/#trans-vinylene difluoride/ trifluoro-nitroso-methane/Trifluor-nitroso-methan (E)-1,2-difluoroethylene/7(E)-1,2-difluoro-ethene/ difluoro-carbamoyl fluoride itrans-vinylene fluoride trifluoro-nitro-methane/Trifluor-nitro-methan//fluoropi 1,2-difluoro-ethene//icis-Vinylene difluoride?/1,2-Dif crin luor-aethen//vinylene fluoride Tetrafluoromethane icis-1,2-difluoro-ethene/icis-Vinylene difluoride//(Z)- Tetrafluorformamidin (germ.) 1,2-difluoroethylene/(Z)-1,2-difluoro-ethene/icis tetrafluorourea vinylene fluoride hypofluorous acid trifluoromethyl ester//Hypofluorigsae 1,1,1,2-Tetrafluoroethane ure-trifluormethylester//trifluoromethyl hypofluorite 1,1,2,2-Tetrafluoroethane trifluoromethanesulfonyl fluoride Fluoroethene N,N-Difluor-trifluorimethylamin (germ.) 1,1,1-Trifluoroethane Trifluormethyloxydifluoramin Ether, methyl trifluoromethyl (Difluoraminoxy)difluorimethylhypofluorit Ethene sulfurcyanide pentafluoride 1,1-Difluoroethane Schwefelcyanid-pentafluorid (germ.) Fluoroethane difluoro-trifluoromethyl-phosphine Ethane Hexafluormethandiamin fluoro-dimethyl-borane perfluoro methylsilane Disiloxane, 1,1,3,3-tetrafluoro-1,3-dimethyl-Trifluoroet Perfluorimethylsilan (germ.) hene Trifluormethyl-tetrafluorphosphoran (germ.) trifluoroacetaldehyde?/Trifluor-acetaldehyd Difluoromethane Pentafluoroethane Fluoroiodomethane Difluoromethyl trifluoromethyl ether fluoromethane/methyl fluoride/Fluor-methan//freon-41 US 2008/O 135817 A1 Jun. 12, 2008 25

trifluoromethyl-silane” CF3SiH3 Tetrafluorosilane methyltrifluorosilane Phosphorus pentafluoride difluoro-methyl-silane Selenium hexafluoride fluoro-methyl-silane Tellurium hexafluoride methylgermane fluorosilane Difluorformimin Nitrosyl fluoride Trifluoromethane Fluorine nitrate trifluoromethane thiol Hydrogen sulfide Trifluormethanthiol (germ.) Ammonia N.N.,1,1-Tetrafluormethylamin Helium difluoro dichlorosilane Hydrogen iodide Difluordichlorsilan (germ.) Krypton difluoro chlorosilane Nitrogen Difluorchlorsilan (germ.) Nitrous oxide Phosphorus chloride difluoride Neon Chlorotrifluorosilane Nitrogen oxide; and Hydrogen chloride Xenon Chlorosilane 9. The insulation-gas according to claim 6, further com Carbon monoxide prising forming an azeotrope of said dielectric gaseous com Carbon dioxide pound. Carbonyl sulfide 10. The insulation-gas according to claim 6, further com Difluoramine prising admixing said dielectric gaseous compound with at trans-Difluorodiazine least one gas selected from the group consisting of nitrogen, cis-Difluorodiazine CO and N.O. Thionyl fluoride 11. The insulation-gas according to claim 6, wherein said Trifluorosilane electrical equipment is at least one selected from the group Nitrogen trifluoride consisting of gas-insulated circuit breakers and current-in Trifluoramine oxide terruption equipment, gas-insulated transmission lines, gas thiazyl trifluoride insulated transformers, and gas-insulated substations. Phosphorus trifluoride Germanium(IV) fluoride c c c c c