Methods for preparing ethers, halogenated ethers, fluoroethers as well as uses of the latter in fire extinguishing systems

TECHNICAL FIELD [0001] The present invention is directed to novel ether compounds and in particular aspects halogenated ether compounds and in other embodiments fluorinated ether compounds. Other aspects of the present invention are also directed to the production of these ether compounds and their uses.

[0002] Certain aspects of the present invention are directed to fluoroether fire extinguishing agents and methods for extinguishing fires using the fluoroethers.

BACKGROUND OF THE INVENTION [0003] Bromine, chlorine, and iodine containing halogenated chemical agents are in general thought to be effective fire extinguishing agents. One mechanism for flame suppression is the radical trap mechanism proposed by Fryburg in Review of Literature Pertinent to Fire Extinguishing Agents and to Basic Mechanisms Involved in Their Action, NACA-TN 2102 (1950). Some have found that the effectiveness of the halogens are on a molar basis in the order CI<Br<l, as reported by Malcom I Vaporizing Fire Extinguishing Agents, Report 117, Dept. of Army Engineering Research and Development Laboratories, Fort Bevoir, VA, 1950 (Project-8-76-04-003).

[0004] The use of iodine-containing compounds as fire extinguishing agents has been avoided in certain circumstances due to the expense of their manufacture or due to toxicity considerations. Until recently, fire extinguishing agents presently in common use were all bromine-containing compounds; Halon 1301 (CF₃Br), Halon 1211 (CF₂BrCI) and Halon 2402 (BrCF₂CF₂Br). The effectiveness of these volatile bromine-containing compounds in extinguishing fires has been described in U.S. Pat. No. 4,014,799 to Owens. Certain chlorine containing compounds are also known to be effective extinguishing agents, for example Halon 251 (CF3CF2CI) as described by Larsen in U.S. Pat. No. 3,844,354.

[0005] Although the above-named bromine or chlorine-containing Halons are effective fire fighting agents, those agents containing bromine or chlorine are asserted by

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Docket No. PC3-045 some to be capable of the destruction of the earth’s protective ozone layer. Also, some believe these agents may also contribute to a greenhouse warming effect, sometimes corresponding to a high global warming potential.

[0006] More recently, hydrofluorocarbons have been proposed for fire suppression, for example in U.S. Pat. No. 5,124,053. However, these compounds may demonstrate a relatively high global warming potential.

SUMMARY OF THE INVENTION [0007] One embodiment of the present invention provides processes for producing halogenated ethers from olefins and alcohols. In one aspect, the present invention provides processes for producing halogenated ethers from olefins and methanol. In a particular aspect, the present invention provides a continuous process of producing halogenated ethers by combining olefins and alcohols in the presence of an aqueous solution containing a base.

[0008] Another aspect of the present invention provides processes for the production of halogenated ether intermediates useful in the production of fluoroethers. In one aspect, the halogenated ether intermediate can be produced by combining the ether with a halogenating agent in the presence of ultraviolet (uv) radiation.

[0009] In a further aspect of the present invention, halogenated ether intermediates can be converted to fluoroethers. In one aspect, CF₃CHFCF₂OCCl3 can be fluorinated in the presence of gaseous HF and a catalyst to produce CF3CHFCF2OCF3. In one aspect, CF3CHFCF2OCHF2 can be produced by reacting CF3CHFCF2OCHCI2 with HF in the presence of a catalyst.

[0010] In another aspect, the halogenated ether intermediate can be fluorinated in the presence of liquid hydrogen fluoride (HF) to obtain the fluoroether intermediate which can subsequently be fluorinated to form a fluoroether. In an exemplary aspect, CF3CHFCF2OCCI3 can be fluorinated in the presence of liquid HF to form CF3CHFCF2OCCI2F which can subsequently be fluorinated in the presence of gaseous HF to form CF3CHFCF2OCF3.

[0011 ] The fluoroethers of this invention may be produced via multi-step routes. For example, CF3CHFCF2OCF2H may be prepared via a three step process that includes:

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i. reaction of methanol with commercially available hexafluoropropene (CF₃CF=CF₂) in the presence of base to produce CF₃CHFCF₂OCH₃;

ii. chlorination of CF3CHFCF2OCH3 with Cl₂ to produce CF₃CHFCF₂OGHCI₂; and iii. fluorination of CF₃CHFCF2OCHCl2 with HF to produce the final product CF3CHFCF2OCF2H. .

. [0012] In still another embodiment of the present invention, fluoroethers of the present invention are used as extinguishants (including streaming and total flooding agents).

[0013] The foregoing and other objects, advantages and features of the present invention may be achieved by employing saturated or unsaturated, fluoroethers and blends ® thereof with other agents as fire extinguishants for use in fire extinguishing methods and apparatus. Methods of according to the present can involve introducing to a fire a saturated or unsaturated, fluoroether in a fire extinguishing concentration and maintaining such concentration until the fire is extinguished. Specific saturated fluoroethers of this invention include: CF₃CHFCF₂OCH₃, CF₃CHFCF₂OCH₂F, CF₃CHFCF₂OCF₂H,

CF3CHFCF2OCF3, (CFaJaCHCFaOCHa, (CF₃)₂CHCF₂OCH₂F, (CFafeCHCFgOCHFa. and (CFajaCHCFgOCFs.

[0014] These fiuoroethers may be used alone, in admixture with each other or as blends with other fire extinguishing agents. Suitable extinguishing agents (’blends*) for admixture with the hydrofluoroethers include CF^CHFGF_3| GFsGFzCFaH, OF₃GH2GF₃,CF3CF2H, and CF₃H.

[0015] In still another embodiment of the present invention, fiuoroethers of the present invention can be used as solvents, refrigerants, blowing agents, etchants, anesthetics, and propellants. Novel compositions of matter such as CF₃CHFCF2OCF3 are also provided.

[0015a] In another aspect, the present invention provides a fire extinguishing, preventing or suppressing system configured to introduce to a space a mixture comprising an extinguishing compound having the general formula Z¹-O-Z², wherein Z¹is selected from the group comprising CF₃CHFCF₂-, CF₃CF₂CF₂-, (CF₃)2 CHCF₂-,

CF₂=C(CF₃)-_i CF₃CF=CF-, CF₂=CFCF₂-, CF₃CH=CF-, CF₃CHBrCF₂-, CF₃CFBrCF₂-, or CF₂BrCF₂- and Z² is selected from the group comprising -CHF₂, -CF_3l -CH₂CF₃, -CH₂Br, -CFBr₂, or-CF₂Br. Preferably, the extinguishing compound comprises about 0.1% (v/v) to about 10% (v/v) ofthe space.

INTELLECTUAL PROPERTY OFFICE OF N.Z.

MAR OT

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PCT/US2003/019693 [0016] The above and other embodiments, aspects, alternatives, and advantage^ of the present invention will become more apparent from the following detailed description of the present invention taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS [0017] Fig. 1. is a diagram of one embodiment of ether production in accordance with an aspect of the present invention.

[0018] Fig. 2 is an illustration of an application of extinguishing mixtures in accordance with an aspect of the present invention.

intellectual property office OF N.Z.

o MAR 2007

RECEIVED

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DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0019] According to an embodiment of the present invention fluoroethers are produced and can be utilized to extinguish combustion. For purposes of this disclosure the term fluoroethers includes all compounds having an ether group and a fluorine atom. Examples of these compounds include, but are not limited to perfiuoroethers, hydrofluoroethers, fluorohalogenated ethers, and/or hydrofluorohalogenated ethers. Exemplary aspects of the present invention are described with reference to Figures 1 and 2.

[0020] Referring now to Fig. 1, a reaction apparatus 10 including a source of olefin 1, a source of alcohol 2, and basic aqueous solution 4 (with the olefin, alcohol, and basic aqueous solution being reagents 7) is shown. The apparatus further includes a reaction vessel 3. In one aspect, olefin 1, alcohol 2, and a basic aqueous -solution 4 are combined to form an ether containing reaction product 5. Reagents can be combined in a batch, semi-continuous, or continuous fashion. Reaction product 5 can remain in reaction vessel 3 and/or be transferred to a separation vessel 6, as shown, where a crude ether product 8 is separated from reagents 7. Reagents 7 can then be returned to reaction vessel 3 to react in the presence of additional or remaining basic aqueous solution 4.

[0021] Depending on the specific olefins and alcohols selected as reagents, the ether containing reaction product may be removed from reaction vessel 3 in a number of forms including as a gas or as a top, middle or bottom liquid layer. Likewise, the separation of crude ether 8 from reagents 7 may involve removal of crude ether product 8 as a gas or as a top, middle, or bottom liquid layer and otherwise removal of reagents 7 as a gas or a top, middle, or bottom layer. Consequently, the return of reagents 7 to reaction vessel 3 may take the form of the return of a gas and/or liquid composition.

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Docket No. PC3-045 [0022] Olefin 1 can have the general formula R’(R²)C=CXY. Olefin 1 can generally be referred to as a hydrogenated, halogenated, and/or a perhalogented olefin. R¹ can include lone halogens, lone hydrogens, halogenated alkyl groups, hydrogenated alkyl groups or perhalogenated alkyl groups either alone or in combination. For purposes of this disclosure, the halogenated alkyl groups includes all alkyl groups having at least one halogen, regardless of what the remaining elements of the alkyl might be. For example, and by way of example only, halogenated alkyl groups include but are not limited to -CHFCI, -CF3, or -CF2CI. R² can include lone halogens, lone hydrogens, halogenated alkyl groups, hydrogenated alkyl groups or perhalogenated alkyl groups either alone or in combination. R¹ and R² can be the same or different groups. In one aspect R¹ includes CF3- or F. In one aspect of the present invention, R² can be H or F. In one combination, R¹ can be F and R² can be F. In another combination, R¹ can be F and R² can be H.

[0023] For purposes of this disclosure, X and Y can generally represent hydrogen and/or the halogens I, Br, Cl, and/or F. In one aspect of the present invention, X and Y can be the same element, for example, X can be F and Y can be F. In an exemplary aspect, X and Y can be different elements, for example, X can be F and Y can be H.

[0024] According to an aspect of the present invention, olefin 1 includes CF₃CF=CF₂ (hexafluoropropene, HFP), CF₃CH=CF₂ (pentafluoropropene, PFP), or CF2=CF₂ (tetrafluoroethene, TFE). In certain aspects of the present invention, olefin 1, can comprise, consist, and/or consist essentially of CF₃CF=CF₂. In exemplary aspects, olefin 1 can comprise, consist, and/or consist essentially of CF₂=CF₂.

[0025] Alcohol 2 includes hydrogenated and halogenated alcohols. According to an aspect of the present invention, alcohol 2 can include methanol (CH₃OH), ethanol (CH₃CH₂OH), and/or isopropanol ((CH₃)₂CHOH).

[0026] Basic aqueous solution 4 can include sufficient base to ensure the formation of an alkoxide upon combination with an alcohol. Bases that can be used to form the alkoxide include those of sodium and potassium such as sodium hydroxide (NaOH) or potassium hydroxide (KOH). In an aspect of the present invention, basic aqueous solution includes KOH.

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PCT/US2003/019693 [0027] According to an aspect of the present invention, basic aqueous solution 4 includes an aqueous solution having a KOH concentration of 10-45% (wt./wt.). This KOH solution can be combined with alcohol 2 in reaction vessel 3 to form a first reactant mixture having an alcohol concentration of 50-60% (wt./wt.) and a KOH concentration of 5-20% (wt./wt.). Olefin 1 can then be combined with the first reactant mixture in reaction vessel 3. Reaction vessel 3 can have a temperature from about 10°Cto about 50°C.

[0028] According to one aspect, the bottom organic phase containing crude ether 8 can be separated from the top mixture that can include reagents 7. In an exemplary aspect reagents 7 can be returned to reaction vessel 3.

[0029] The crude ether 8 of the present invention can generally be referred to as an ether or halogenated ether and have the general formula R³CXY-O-R⁴. The R³group can include hydrogenated alkyl groups, halogenated alkyl groups, and/or perhalogenated alkyl groups. For example, and by way of example only, R³ can include CF3CHF-, CF3CH2-, and/or CHF2-. The R⁴ group can include hydrogenated alkyl groups, halogenated alkyl groups, and/or perhalogenated alkyl groups. For example, and by way of example only, R⁴ can include -CH3, -CH₂CH₃, and/or CH(CH₃)₂. In an aspect of the present invention, the halogenated ether includes CF₃CHFCF₂OCH₃. In another aspect of the present invention, the halogenated ether includes CF₃CH₂CF₂OCH₃. In still another aspect of the present invention, the halogenated ether includes CHF₂CF₂OCH₃. Non-limiting examples 1-3 demonstrate aspects of ether preparation according to the present invention.

[0030] According to another aspect ofthe present invention'a halogenated ether intermediate can be formed by reacting an ether with a halogen in the presence of actinic energy. This reaction can be carried out in a photochemical reactor. The reactor may be configured to provide actinic energy to its content from an internal and/or an external source. For example, and by way of example only, a medium pressure mercury lamp (100 watt, 11.49 watt total radiant energy) can be utilized to provide the necessary radiation from within the reactor. Other configurations may include the use of 90% 3500 angstrom range of photon black light providing 24 watts of total radiant energy. The reactor may be cooled, for example, from a municipal water source.

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PCT/US2003/019693 [0031] The halogen can include chlorine (Cl₂). Depending on the product desired, halogens such as bromine or iodine may be utilized as well. The reaction can be performed at a temperature from about 10°C to about 70°C.

[0032] In an exemplary aspect, methods include providing a photochemical reactor containing an ether. The ether can have the general fonnula R³CXY-O-R⁴, as described above.

[0033] The halogenated either intermediate can have the general formula R⁵CXY-O-R⁶. The R⁵ group can include hydrogenated alkyl groups, halogenated alkyl groups, and/or perhalogenated alkyl groups. For example, and by way of example only, R⁵ can include CF3CHF-, CF3CCIF-, CF3CH2-, CF3CHCI-, CF3CCI2-, CHF2-, and/or CCIF2-. The R⁶ group can include halogenated alkyl groups or perhalogenated alkyl groups. For example, and by way of example only, R⁶ can include -CH2CI, -CHCI₂, and/or -CCI₃. In an aspect of the present invention, the halogenated ether intermediate can include CF₃CHFCF₂OCCI₃. In another aspect of the present invention, the halogenated ether intermediate can include CF₃CHFCF₂OCHCI₂. In still another aspect of the present invention, the halogenated ether intermediate can include CF₃CHFCF₂OCH₂CI. In an exemplary aspect, the halogenated ether intermediate can include CF₃CCIFCF₂OCCl3.

[0034] In certain aspects of the present invention, two halogenated ether intermediates useful in the production of fluoroethers can be produced according to the present invention. In one aspect, the ether CF₃CHFCF₂OCH₃ can be chlorinated according to the present invention to produce a mixture of halogenated ether intermediates such as CF₃CHFCF₂OCHCi₂ and CF₃CHFCF₂OCCI₃. Non-limiting Example 4 demonstrates an aspect of the halogenated ether intermediate production methods according to the present invention.

[0035] Another aspect of the present invention provides methods for converting halogenated ether intermediates to useful fluoroethers. Aspects of the present invention provide efficient processes for fluorinating halogenated ethers to produce heretofore unknown compounds.

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Docket No. PC3-045 [0036] In an aspect of the present invention, the halogenated ether intermediate can have the general formula R⁵CXY-O-R⁶, as described above. In an aspect of the present invention, the halogenated ether intermediate can be selectively fluorinated in the presence of HF and a catalyst to produce a fluoroether.

[0037] The catalyst can include a chromium/carbon catalyst that has been prefluorinated. The catalyst utilized may take pure or supported forms. Supports include but are not limited to those of activated carbon. The catalysts themselves include but are not limited to such catalysts as those of chromium, nickel, iron, vanadium, manganese, cobalt, and/or zinc. The preparation can occur from about 100 °C to about 300 °C. In certain aspects, the temperature of the reaction is about 200 °C. [0038] The fluoroether produced can have the general formula R⁷-O-R⁸. The R⁷group can include hydrogenated alkyl groups, hydrofluorohalogenated alkyl groups, hydrofluorinated alkyl groups, fluorohalogenated alkyl groups, and/or perfluorinated alkyl groups. For example, and by way of example only, R⁷ can include CF3CHFCF2-, CF3CCIFCF2-, CF3CF2CF2-, CF3CH2CF2-, CF3CHCICF2-, CF3CCI2CF2-, CHF2CF2-, CF3CF2-, and/or CCIF2CF2-. The R⁸ group can include hydrofluorohalogenated alkyl groups, hydrofluorinated alkyl groups, fluorohalogenated alkyl groups, and/or perfluorinated alkyl groups. For example, and by way of example only, R⁸ can include CFCI2, -CF2Cl, -CF_3i -CHFCI, -CF₂H, and/or CFH₂. In an aspect of the present invention, the fluoroether includes the hydrofluoroether CF3CHFCF2OCF3. In another aspect of the present invention, the fluoroether includes the hydrofiuoroether CF3CHFCF2OCHF2. In still another aspect of the present invention, the fluoroether includes the perfluorinated ether CF₃CF2CF2OCF₃.

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Docket No. PC3-045 [0039] According to one aspect of the present invention, an ether can be fluorinated in the presence of liquid hydrogen fluoride (HF). In one aspect, an ether having at least one of the halogens I, Br, or Cl can be fluorinated in the presence of liquid HF to produce a fluoroether. The fluoroether produced according to this aspect of the present invention can be characterized as having at least one more fluorine atom than the ether. For example, and by way of example only, the ether CF3CHFCF2OCCI3 can be fluorinated in the presence of liquid HF to produce the fluoroether CF3CHFCF2OCFCI2. In one aspect of the present invention, this fluorination can occur from about 40°C to about 120°C. In one aspect of the present invention, this fluorination can occur at approximately 70°C.

[0040] The fluoroether produced according to an aspect of the present invention may be utilized as starting materials for other aspects of the present invention. Accordingly, the ether can be fluorinated at about 70°C and subsequently fluorinated at about 200°C. The ether may also be fluorinated at about 70°C and subsequently fluorinated at about 230°C or 280°C. For example, and by way of example only, the ether CF3CHFCF2OCGI3 can be fluorinated in the presence of liquid HF to produce the fluoroether CF3CHFCF2OCFCI2, which can be fluorinated in the presence of HF and a catalyst as described above to produce the hydrofluoroether CF₃CHFCF₂OCF₃.

[0041] An embodiment of the present invention also provides multi-step synthetic processes for the production of fluoroethers. According to one aspect of the present invention, methods are provided for manufacturing fluoroethers that include combining an alcohol with an olefin to produce an ether. Subsequently, reacting the ether with a halogenating agent to produce a halogenated ether intermediate and then fluorinating the halogenated ether intermediate with HF to from a fluoroether. In another aspect, the halogenated ether intermediate can be fluorinated with HF at a first temperature to from a fluoroether intermediate. The fluoroether intermediate can then be fluorinated with HF at a second temperature to form a fluoroether.

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Docket No. PC3-045 [0042] An embodiment of the present invention also provides halogenated ether compounds. Generally, these ether compounds have the formula R⁹OR¹⁰. Generally, R⁹ can be partially or fully halogenated, saturated or unsaturated, organic groups, and R¹⁰ can be partially or fully halogenated, saturated or unsaturated organic groups. In particular aspects, these halogenated ether compounds include CF₃CHFCF₂OCF₃.

The structure of CF₃CHFCF₂OCF₃ was confirmed by gas chromatography mass spectrometry (GC-MS) and fluorine (¹⁹F), proton (¹H), and carbon (¹³C) nuclear magnetic resonance (NMR). The boiling point of this compound was also determined. GC-MS (m/e): 69 (CF₃), 82 (CF₃CH), 101 (CF₃CHF),

129 (CHFCF₂OCF or CHCF₂OCF₂), 135 (CF₂OCF₃),

151 (CF₃CHFCF₂), 217 (CF₃CHFCF₂OCF₂)

High Resolution MS Theoretical: 235.98837 Found: 235.98726

NMR: F¹⁹ (282 MHz, CFCI₃): δ -55.4 (t, 3F, J = 8.9 Hz), -75.3 (m, 3F),

-81.4 (m, 2F), -211.5 (d, t, q, 1F, J = 43.64,10.91 Hz) ppm H¹: (300 MHz, CDCI3): δ 4.86 (d, t, q, 1H, J = 43.8, 5.51,5.98 Hz) ppm C¹³: (75 MHz, CDCI3): δ 77 (t, J = 31.78 Hz), 84.1 (d, t, q, J = 204.69, 35.79, 35.79 Hz), 119.2 (q, J = 267.68 Hz), 112 -125 (m) ppm

Boilinij point: 23 - 24‘C.

[0043] Non-limiting Examples 5,6,7, and 8 demonstrate preparations according to aspects of the present invention.

[0044] The present invention also provides fire extinguishing mixtures which comprise fluoroether extinguishing agents that can extinguish fires through inertion, and/or dilution, as well as, chemical, physical, and/or thermal extinguishment methods. Thermal extinguishment includes cooling a combustion. The present invention also provides methods of extinguishing, preventing, and/or suppressing a fire using such fire extinguishing mixtures. The present invention further provides fire extinguishing, preventing, and/or suppressing systems for delivering such fire extinguishing mixtures. Exemplary aspects of the present invention are described with reference to Fig. 2.

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Docket No. PC3-045 [0045] Referring to Fig. 2, a space 27 configured with a fire extinguishing system 11 is shown. Fire extinguishing system 11 includes an extinguishing agent storage vessel 13 contiguous with an extinguishing agent dispersing nozzle 17. As depicted, a combustion 21 occurs within a pan 23 on a pedestal 25. An extinguishing mixture 19 exists within space 27 and is applied to combustion 21 to substantially extinguish the flame.

[0046] While depicted in two dimensions, space 27, for purposes of this disclosure, should be considered to have a volume determined from its dimensions (e.g., width, height and length). While Fig. 2 illustrates a system configured for extinguishing fires within a space that, as illustrated, appears to be enclosed, the application of the mixtures, systems, and methods of the present invention are not so limited. In some aspects, the present invention may be used to extinguish fires in open spaces, as well as, confined spaces.

[0047] Alternatively, the fluoroether extinguishing agents may be applied to a fire through the use of conventional portable fire extinguishing equipment. Fluoroether containing systems in accordance with this invention may be conveniently pressurized with diluents up at any desirable pressure up to about 600 psig at ambient conditions. [0048] All combustion suitable for extinguishment, suppression or prevention using the mixtures of the present invention or utilizing the methods and systems according to the present invention, are at least partially surrounded by a space. The available volume of this space can be filled with the compositions of the present invention to extinguish, suppress, and/or prevent combustion. Typically, the available volume is that volume which can be occupied by a liquid or a gas [i.e. that volume within which fluids (gases and liquids) can exchange]. Solid constructions typically are not part of the available volume.

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Docket No. PC3-045 [0049] Furthermore, Fig. 2 illustrates a single extinguishing agent storage vessel 13. It should be understood that extinguishing mixture 19 can be provided to room 27 from multiple extinguishing agent storage vessels 13 and the present invention should not be limited to mixtures, methods, and/or systems that can be provided from a single vessel nor methods or systems that utilize a single vessel. Generally, combustion 21 is extinguished when extinguishing mixture 19 is introduced from vessel 13 through nozzle 17 to space 27. It should also be understood, that while Fig. 2 illustrates a single nozzle 17, multiple nozzles may be utilized, and the present invention should not be limited to mixtures, methods, and/or systems utilizing a single nozzle.

[0050] In one aspect of the present invention, extinguishing mixture 19 can comprise, consist essentially of, and/or consist of a fluoroether extinguishing agent. In another aspect, extinguishing mixture 19 can comprise, consist essentially of, and/or consist of a fluoroether extinguishing agent and a suppressing additive and/or other fire extinguishing agents.

[0051] The suppressing additive employed can include diluent gases, water, and/or mixtures thereof. Exemplary diluent gases can include nitrogen, argon, helium, carbon dioxide, and/or mixtures thereof. In an exemplary aspect, these gases can deprive fires of necessary ingredients, such as oxygen and/or fuel. In the same or other aspects, these diluent gases resist decomposition when exposed to combustion, in some cases, these gases are referred to as inert gases. An exemplary diluent gas can comprise, consist essentially of, and/or consist of nitrogen.

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Docket No. PC3-045 [0052] Generally, the fluoroether extinguishing agent can have the formula R⁹OR¹⁰. Generally, R⁹ can be partially or fully halogenated, saturated or unsaturated, organic groups, and R¹⁰ can be partially or fully halogenated, saturated or unsaturated organic groups. More specifically, the fluoroether extinguishing agents of the present invention can have the general formula Z¹-O-Z². The Z¹ group can include CF3CHFCF2-, CF3CF2CF2-, (CF3)2CHCF2-, CHF2CF2-, CF2=C(CF3)-, cf3cf=cf-, CF2=CFCF2-, CF3CH=CF-, CFaCHBrCFz-, CF3CFBrCF2- or CF2BrCF2-. The Z² group can include -CHF2, -CF₃, -CH₂F, -CH₂Br, -CFBr₂, -CHFBr or -CF₂Br. In particular aspects the fluoroether extinguishing agent includes CF₃CHFCF₂OCF₃ and/or CF₃CHFCF₂OCHF₂, and/or CHF₂CF₂OCF₃.. GenerallyFluoroether extinguishing agent concentrations lying in the range from about 3 to about 15% in air, preferably from about 5 to about 10% in air, on a v/v basis can be employed.

[0053] These fluoroether extinguishing agents may be used alone, as admixtures with each other or as blends with other fire extinguishing agents. As admixtures with fire extinguishing agents, concentrations lying in the range from about 3 to about 15%, and/or from about 5 to about 10% in air, on a v/v basis, can be employed. Where the fluoroether extinguishing agents of the present invention are employed in admixture with other fire extinguishing agents (blends), the fluoroether extinguishing agents can comprise of at least about 10% by weight of the blends, and the overall concentration of the blend lies in the range from about 3 to about 15% and/or from about 5 to about 10% in air, on a v/v basis. The fire extinguishing agents of this invention are suitable for use in both total flooding and portable fire suppression applications.

[0054] It should be understood that the % (v/v) values set forth in this description and in the claims are based on space volume and refer to the design concentration as adopted and described by the National Fire Protection Association in NFPA 2001, Standard on Clean Agent Fire Extinguishing, 2000 edition.

[0055] The equation used to calculate the concentrations of extinguishing compounds has likewise been adopted by the National Fire Protection Association and is as follows:

W=V/s(C/100-C)

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Where:

W = weight of extinguishing compound (kg)

V = volume of test space (m³) s = specific volume of extinguishing compound at test temperature (m³/kg)

C = concentration (% (v/v)) [0056] Suitable fire extinguishing agents for blends with the fluoroether extinguishing agents include: difluoromethane (HFC-32), chlorodifluoromethane (HCFC-22), 2,2-dichloro-1,1,1-trifluoroethane (HCFC-123), 1,2-dichloro-1,1,2trifluoroethane (HCFC-123a), 2-chloro-1,1,1,2-tetrafluoroethane (HCFC-124), 1-chloro1.1.2.2- tetrafluoroethane (HCFC-124a), pentafluoroethane (HFC-125), 1,1,2,2tetrafluoroethane (HFC-134), 1,1,1,2-tetrafluoroethane (HFC-134a), 3,3-dichioro1.1.1.2.2- pentafluoropropane (HCFC-225ca), 1,3-dichloro-1,1,2,2,3pentafluoropropane (HCFC-225cb), 2,2-dichloro-1,1,1,3,3-pentafluoropropane (HCFC225aa), 2,3-dichloro-1,1,1,3,3-pentafluoropropane (HCFC-225da), 1,1,1,2,2,3,3heptafluoropropane(HFC-227ca), 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea),

1,1,1,2,3,3-hexafluoropropane (HFC-236ea), 1,1,1,3,3,3-hexafluoropropane (HFC236fa), 1,1,1,2,2,3-hexafluoropropane (HFC-236cb), 1,1,2,2,3,3-hexafluoropropane (HFC-236ca), 3-chlor0-1,1,2,2,3-pentafludrdpfopane (HCFC-235ca), 3-chloro-l ,1,1,2,2pentafluoropropane (HCFC-235cb), 1-chloro-1,1,2,2,3-pentafluoropropane (HCFC235cc), 3-chloro-1,1,1,3,3-pentafluoropropane (HCFC-235fa), 1,1,1,3,3pentafluoropropane (HFC-245fa), 3-chloro-1,1,1,2,2,3-hexafluoropropane (HCFC226ca), 1-chloro-1,1,2,2,3,3-hexafluoropropane (HCFC-226cb), 2-chloro-1,1,1,3,3,3hexafluoropropane (HCFC-226da), 3-chloro-1,1,1,2,3,3-hexafluoropropane (HCFC226ea), and 2-chloro-1,1,1,2,3,3-hexafluoropropane (HCFC-226ba), and inert gases such as nitrogen.

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PCT/US2003/019693 [0057] The fluoroether fire extinguishing agents of the present invention may be effectively employed at substantially any minimum concentrations at which fire may be extinguished, the exact minimum level being dependent on the particular combustible material, the particular fluoroether extinguishing agent, and the combustion conditions. In general, however, acceptable results are achieved where the fluoroether extinguishing agents or mixtures and blends thereof are employed at a level of at least about 3% (v/v). Where fluoroether extinguishing agents alone are employed, acceptable results are achieved with fluoroether extinguishing agent levels of at least about 5% (v/v). Likewise, the maximum amount to be employed may be governed by matters of economics and potential toxicity to living things. About 15% (v/v) provides a convenient maximum concentration for use of fluoroether extinguishing agents and mixtures and blends thereof in occupied areas. Concentrations above 15% (v/v) may be employed in unoccupied areas, with the exact level being determined by the particular combustible material, the fluoroether extinguishing agents (or mixture or blend thereof) chosen, and the conditions of combustion. A concentration of the fluoroether extinguishing agents, mixtures, and blends in accordance with an aspect of this invention lies in the range of about 5 to 10% (v/v).

[0058] In particular aspects, an extinguishing mixture comprising, consisting essentially of, and/or consisting of CF3CHFCF2OCF3 may be employed. CF3CHFCF2OCF3 can be employed at concentrations of about 5 % (v/v).

[0059] Some of the applications of the fluoroether extinguishing agents of the present invention are the extinguishing of liquid and gaseous fueled fires, the protection of electrical equipment, ordinary combustibles such as wood, paper, and textiles, hazardous solids, and the protection of computer facilities, data processing equipment, and control rooms.

[0060] The novel ethers according to the present invention can also be introduced to a fire for suppression purposes as a liquid or gas or combination of both. This is sometimes referred to as utilizing the composition as a streaming agent. The novel ethers according to the present invention can be introduced to fires in combination with other compounds as blends.

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Docket No. PC3-045 [0061] In still another embodiment of the present invention, ethers of the present invention are used either alone or as blends as extinguishants, including streaming and total flooding agents, solvents, refrigerants, blowing or expansion agents, etchants, anesthetics, propellants, and as power cycle working fluids.

[0062] The novel ethers of the present invention may be used to produce refrigeration by condensing the ether either alone or as a blend and thereafter evaporating the condensate in the vicinity of a body to be cooled. The novel ethers of the present invention may also be used to produce heat by condensing the refrigerant in the vicinity of the body to be heated and thereafter evaporating the refrigerant.

[0063] The invention will be further described with reference to the following specific examples. However, it will be understood that these examples are illustrative in nature and not restrictive in nature. Where referenced, G.C. area % corresponds to percentage area of peak in comparison to all peaks generated when the respective sample is analyzed by a gas chromatograph equipped with a flame ionization detector and a silica-plot column.

Example 1: Ether Preparation aq. KOH

CF₃CF=CF₂ + CH₃OH-► CF₃CHFCF₂OCH₃ [0064] An aqueous 45% (wt./wt.) KOH solution is added to methanol to produce a mixture containing 60% (wt./wt.) methanol and 18% (wt./wt.) KOH. This mixture is placed in a three-neck glass flask equipped with a dry ice condenser, a dip tube, and a thermometer. HFP is fed through the dip tube into the solution at -3°C to 0°C. The condenser is kept at -30 to -40°C in order to condense unreacted HFP back into the reactor. A water bath is used to control the exothermic reaction. When the solution becomes a milky suspension, the mixture is drawn out of the reactor and allowed to phase separate. The bottom organic phase containing crude CF₃CHFCF₂OCH₃ is separated out, and the top mixture with additional methanol is fed back to the reactor. Four aliquots of the crude CF₃CHFCF₂OCH₃ are collected at time intervals and analyzed by gas chromatography for lights, unreacted olefin, ether, and heavies. The results are shown below in Table 1.

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<td colspan="6"> Table 1</td>

<td></td><td colspan="5"> aq. KOH CF₃CF=CF₂ + CH3OH-► CF₃CHFCF₂OCH₃</td>

<td></td><td></td><td colspan="4"> (G.C. Area %)</td>

<td> Aliquot</td><td> Crude Product Collected (g)</td><td> Lights</td><td> Olefin CF₃CF=CF₂</td><td> CF₃CHFCF₂OCH₃</td><td> Heavies</td>

<td> A</td><td> 22.5</td><td> trace</td><td> 4.04</td><td> 89.09</td><td> 6.12</td>

<td> B</td><td> 18.5</td><td> 0.46</td><td> 3.49</td><td> 88.72</td><td> 6.73</td>

<td> C</td><td> 26.6</td><td> 0.44</td><td> 3.49</td><td> 85.59</td><td> 9.73</td>

<td> D</td><td> 97.84</td><td> trace</td><td> 5.14</td><td> 87.78</td><td> 6.11</td>

<td colspan="6"> Overall Crude Yield 84.9% based on HFP</td>

Example 2: Ether Preparation aq. KOH

CF₃CF=CF₂ + CH₃OH-► CF₃CHFCF₂OCH₃ [0065] Example 2 is performed as Example 1 with the modification that the reaction is performed using an aqueous mixture having 13% (wt./wt.) KOH and 57% (wt./wt.) methanol at 15°C to 25°C, and two collection aliquots are taken and analyzed by gas chromatography. The gas chromatography results are reported below in Table

2.

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<td colspan="6"> Table 2 aq. KOH CF₃CF=CF₂ + CH₃OH-► CF₃CHFCF₂OCH₃</td>

<td></td><td></td><td colspan="4"> G.C. Area %</td>

<td> Aliquot</td><td> Crude Product Collected (g)</td><td> Lights</td><td> Olefin CF₃CF=CF₂</td><td> CF₃CHFCF₂OCH₃</td><td> Heavies</td>

<td> A</td><td> 77.2</td><td> trace</td><td> 0.65</td><td> 94.99</td><td> 3.68</td>

<td> B</td><td> 45</td><td> trace</td><td> 1.69</td><td> 95.08</td><td> 2.12</td>

Example 3: Ether Preparation aq. KOH

CF₂=CF₂ + CH₃OH-CHF₂CF₂OCH₃ [0066] Example 3 is performed as example 1 with the modification that the reaction is performed in a 600 cc stainless steel pressure reactor using an aqueous mixture having 10% (wt./wt.) KOH and 50% (wt./wt.) methanol. The reactor is cooled to -10°C and then pressurized with tetrafluoroethylene (CF₂=CF₂) which is first passed through a bubbler filled with α-pinene. The reaction is carried out at 60°C under 60 psig to generate 97% (G.C. Area %) pure CHF₂CF₂OCH₃. No polytetrafluoroethylene is visually observed.

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Example 4: Preparation of Halogenated Ether Intermediates uv light

CF3CHFCF2OCH3 + Cl₂-► CF3CHFCF2OCHCI2+CF3CHFCF2OCCI3 [0067] This reaction is carried out in a jacketed glass photochemical reactor cooled with tap water. A medium pressure mercury lamp (100 watt, 11.49 watt total radiant energy) is used for the reaction. Chlorine gas is bubbled into 400g of liquid CF3CHFCF2OCH3 at 20°C - 30°C and by-product HCI is vented to a water scrubber. The reaction is stopped, the crude reaction mixture is sampled, analyzed by gas chromatography, and then distilled. Two major products are generated in the reaction, CF3CHFCF2OCHCI2 [37% (G.C. Area %), b.p. 75°C@42 cmHg] and CF₃CHFCF₂OCCI; [61% (G.C. Area %), b.p. 82°C@32 cmHg] for a total of 482g of recovered crude material.

Example 5: Preparation of Fiuoroethers

Cr/AC - gas phase

CF₃CHFCF₂OCHCI₂ + HF-► CF₃CHFCF₂OCHF₂ [0068] 50 g chromium/carbon catalyst is charged to a 0.5 inch x 24 inch long

Inconel® tubing reactor which is heated using radiant heat. After pre-fluorinating the catalyst, HF and 99.8% pure CF₃CHFCF₂OCHCI₂ are fed into a reactor at predetermined rates and temperature under atmospheric pressure. The crude product is collected in an ice water scrubber and washed with H₂O, dried over MgSO4, and purified by distillation. The boiling point of the resulting CF₃CHFCF₂OCHF₂ is 47-48°C and the density d=1.529. GC analysis of the collections corresponding to the parameters utilized are shown in the Table 3 below.

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<td colspan="7"> Table 3 Cr/AC - gas phase</td>

<td colspan="4"> . urr</td><td colspan="3" rowspan="2"> -► CF₃CHFCF₂OCHF₂</td>

<td></td><td colspan="3"> υΓ3^πΓνΓ2νυπυΐ2 τ nr</td>

<td></td><td></td><td></td><td></td><td colspan="3"> G.C. Area %</td>

<td> Run</td><td> Temp. (°C)</td><td> HF/RfOCHCb (mole ratio)</td><td> Contact time (sec)</td><td> r,ochf₂</td><td> RfOCHFCI</td><td> RfOCHCfe</td>

<td> 1</td><td> 120</td><td> 7.6/1</td><td> 17</td><td> 95.6</td><td> 1.11</td><td> 0.23</td>

<td> 2</td><td> 125</td><td> 6.2/1</td><td> 21</td><td> 99.2</td><td> 0.05</td><td> 0.003</td>

<td> 3</td><td> 150</td><td> 7.8/1</td><td> 12</td><td> 98.3</td><td> 0.23</td><td> 0.003</td>

<td> 4</td><td> 150</td><td> 6.0/1</td><td> • 11.6</td><td> 98.8</td><td> 0.05</td><td> 0.927</td>

R_f=CF₃CHFCF₂

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Example 6: Preparation of Fluoroethers

Cr₂O₃ - gas phase

CF₃CHFCF₂OCCI₃ + HF-► CF₃CHFCF₂OCF₃ [0069] 38 g chromium (III) oxide catalyst* is charged to a 0.5 inch x 14.125 inch long Inconel® tubing reactor which is heated by a ceramic fiber heater. The catalyst is dried under nitrogen at 250-300°C. After drying, the catalyst is prefluorinated at 250300°C using a HF:N₂ mixture (using a 1:20 dilution). This prefluorination is continued until HF is detected exiting the reactor. At this point, the nitrogen is turned off, and the temperature is increased to 350°C. The catalyst is held under these conditions for 16 hours. After pre-flu orinating the catalyst, HF and CF₃CHFCF₂OCCI₃ were fed into the reactor at predetermined rates and temperature under atmospheric pressure. The crude product is washed with H₂O, passed over calcium sulfate, and collected in a dry ice/acetone cooled trap. GC analysis of the reactor products corresponding to the parameters utilized are shown in the Table 4 below. The boiling point of the resulting CF₃CHFCF₂OCF₃ was 23-24°C.

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<td colspan="6"> Table 4</td>

<td rowspan="2"></td><td colspan="5"> Cr₂O₃ - gas phase</td>

<td colspan="3"> CF₃CHFCF₂OCCI₃ + HF-</td><td colspan="2"> —►CF₃CHFCF₂OCF₃</td>

<td></td><td></td><td></td><td></td><td colspan="2"> G.C. Area %</td>

<td> Run</td><td> Temp. (°C)</td><td> HF/RfOCCI₃ (mole ratio)</td><td> Contact time (sec)</td><td> RfOCFg</td><td> CF₃CHFCF₃</td>

<td> 1</td><td> 150</td><td> 6.04</td><td> 8.66</td><td> 4.28</td><td> 15.78</td>

<td> 2</td><td> 175</td><td> 7.12</td><td> 8.13</td><td> 62.00</td><td> 12.21</td>

<td> 3</td><td> 200</td><td> 7.12</td><td> 8.09</td><td> 71.89</td><td> 13.67</td>

<td> 4</td><td> 200</td><td> 10.87</td><td> 19.27</td><td> 72.58</td><td> 15.41</td>

<td> 5</td><td> 200</td><td> 21.07</td><td> 8.43</td><td> 77.06</td><td> 12.01</td>

<td> 6</td><td> 250</td><td> 8.0</td><td> 6.58</td><td> 30.4</td><td> 52.23</td>

Rf=CF₃CHFCF₂, ^TSynetix® CP200A catalyst, PO Box 1, Billingham, TS23 1 LB, UK

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Example 7: Preparation of Fluoroethers Liquid phase

CF₃CHFCF₂OCCI₃ + HF-► CF₃CHFCF₂OCFCI₂ [0070] 405 g of CF₃CHFCF₂OCCI₃ produced according to the present invention is placed in a stainless steel pressure reactor. The reactor is cooled to -9°C and 76g of HF is added to the reactor. The reaction is carried out at 70°C, and a pressure of 300 psig is maintained in the reactor by venting the formed HCI to a water scrubber. 367.6 g crude product is collected. Gas chromatography analysis showed 91.1% (G.C. Area %) of CF₃CHFCF₂OCFCI₂₎ 3.6% (G.C. Area %) of CF₃CHFCF₂OCF₂CI, and 3.5% (G.C. Area %) of unreacted CF₃CHFCF₂OCCI₃.

Example 8: Preparation of Fluoroethers

Cr/AC - gas phase

CF₃CHFCF₂OCFCI₂ + HF-► CF₃CHFCF₂OCF₃ [0071] Similar set-up and procedure was used as in Example 6 above. After pre-fluorinating the catalyst, HF and 99% pure CF3CHFCF₂OCFCI₂ are fed into a reactor at predetermined rates and temperature under atmospheric pressure. The resulting crude product is passed through a heated scrubber and collected in a trap cooled by dry ice/acetone. This liquid is then dried over CaSO4 and GC analysis of the collected crude mixtures is shown in Table 5. The collected material is combined and distilled to give two fractions of CF₃CHFCF₂OCF₃ of 99.6% and 99.77% G.C. assay at a boiling point of 23-24°C.

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<td colspan="7"> Table 5</td>

<td rowspan="2"></td><td colspan="6"> Cr/AC - gas phase</td>

<td colspan="2"> CF3CHFCF2OCFCI2 + HF</td><td colspan="4"> -► CF₃CHFCF₂OCF₃</td>

<td></td><td></td><td></td><td></td><td colspan="3"> G.C. Area %</td>

<td> Run</td><td> Temp. (°C)</td><td> HF/RfOCFCI₂ (mole ratio)</td><td> Contact Time (sec)</td><td> HFC-227ea</td><td> RfOCFg</td><td> RfOCF₂CI</td>

<td> 1</td><td> 230</td><td> 9.4/1</td><td> 9</td><td> 3.7</td><td> 91.7</td><td> 2.7</td>

<td> 2</td><td> 200</td><td> 10/1</td><td> 11</td><td> 6.6</td><td> 66.8</td><td> 24.4</td>

<td> Rf=C</td><td colspan="6"> F₃CHFCF₂</td>

EXAMPLE 9 [0072] This example demonstrates the desirable “throw” obtainable with the fire suppression agents of the present invention when employed in portable (“streaming”) applications. The throw is the distance the stream of agent can be discharged; the longer the throw the better, as this allows extinguishment without approaching the fire at too close a distance, which can lead to exposure of the operator to fire and toxic fumes from the combustion process.

[0073] A 150 mL SS cylinder is equipped with an inlet tube and a dip tube connected via an on/off valve to a delivery nozzle. The cylinder is charged with 50 grams of CF₃CHFCF₂OCF₂H and then pressurized with nitrogen to the desired pressure. The cylinder contents are completely discharged and the throw distance noted (Table 6).

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<td colspan="2"> Table 6</td>

<td colspan="2"> Throw vs. Pressure for CF₃CHFCF₂OCF₂H System</td>

<td> Pressure, psig</td><td> Throw, feet</td>

<td> 25</td><td> 10</td>

<td> 80</td><td> 15</td>

<td> 120</td><td> 17</td>

<td> 150</td><td> 18</td>

EXAMPLE 10 [0074] This example demonstrates the extinguishment of Class B fires with the agents of the present invention. A 150 mL SS cylinder is equipped with an inlet tube and a dip tube connected via an on/off valve to a delivery nozzle. The cylinder is charged with 30 grams of CF₃CHFCF₂OCF₂H and then pressurized with nitrogen to 120 psig. A 2 inch x 4 inch x 0.5 inch SS pan is filled with 20 mL of methanol. The methanol is ignited and allowed to bum for 30 seconds; the agent is then discharged from a distance of 4 feet onto the fire. The methanol fire can be extinguished in 1.5 seconds; a total of 16 grams of agent was discharged:

EXAMPLE 11 [0075] The method of Example 10 is employed with acetone, isopropanol, and heptane fuels. All fires are rapidly extinguished (see Table 7).

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<td colspan="3"> TABLE 7</td>

<td colspan="3"> Extinguishment with CF₃CHFCF₂OCF₂H</td>

<td> Fuel</td><td> Extinguishing Time, seconds</td><td> Agent discharged, Grams</td>

<td> Acetone</td><td> 2.0</td><td> 25</td>

<td> Isopropanoi</td><td> 1.5</td><td> 21</td>

<td> Heptane</td><td> 1.8</td><td> 11</td>

EXAMPLE 12 [0076] This example demonstrates the extinguishment of deep-seated Class A fires with the agents of the present invention. A 150 mL SS cylinder is equipped with an inlet tube and a dip tube connected via an on/off valve to a delivery nozzle. The cylinder is charged with 30 grams of CF3CHFCF2OCF2H and then pressurized with nitrogen to 120 psig. A wood crib can be constructed of six layers of 6 inch x 2 inch by 0.125 inch strips of kiln dried fir, each layer consisting of 4 pieces. The crib is soaked with heptane, ignited, and allowed to burn for five minutes. The agent is then discharged onto the fire, rapid (&lt; 2 seconds) extinguishment can be achieved; a total of 25 grams of agent is discharged. Immediately after extinguishment, the wood crib is cold to the touch, demonstrating the efficient suppression afforded by the agent.

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Example 13: CF₃CHFCF₂OCF₃ Cup Burner [0077] Extinguishing concentrations of the hydrofluoroether CF₃CHFCF₂OCF₃ can be determined using a cup burner apparatus, as described in M. Robin and

Thomas F. Rowland, “Development of a Standard Cup Burner Apparatus: NFPA and

ISO Standard Methods, 1999 Halon Options Technical Working Conference, Apr.

27-29,1999, Albuquerque, N.Mex.”. The cup burner method is a standard method for determining extinguishing mixtures and has been adopted in both national and international fire suppression standards. For example, NFPA 2001 Standard on Clean · Agent Fire Extinguishing Systems and ISO 14520-1: Gaseous Fire-Extinguishing Systems, both utilize the cup burner method.

[0078] A mixture of air and CF₃CHFCF₂OCF₃ is flowed through an 85 mm (ID) Pyrex chimney around a 28 mm (OD) fuel cup. A wire mesh screen and a 76 mm (3 inch) layer of 3 mm (OD) glass beads are employed in the diffuser unit to provide thorough mixing of air and CF₃CHFCF₂OCF₃.

[0079] n-Heptane is gravity fed to a cup from a liquid fuel reservoir consisting of a 250 mL separatory funnel mounted on a laboratory jack, which can allow for an adjustable and constant liquid fuel level in the cup. The fuel is ignited with a propane mini-torch and the chimney is placed on the apparatus. The fuel level is then adjusted such that fuel is 1-2 mm from the ground inner edge of the cup. A 90 second preburn period is allowed, and a primary flow of air is initiated via a calibrated flow meter @ 2040 L/min.

[0080] Primary and secondary air flows are monitored by calibrated flow meters (210,225,230 and 240 tubes). The flows are maintained until the flames are extinguished. A constant primary flow (240 tube) between 20 to 40 L/min is maintained in all the tests. The secondary flow of air is passed through CF₃CHFCF₂OCF₃contained in a 1150 ml steel mixing chamber equipped with a dip-tube. The secondary flow, containing air saturated with CF₃CHFCF₂OCF₃, exits the mixing chamber and is mixed with the primary air flow before entering the cup burner's diffuser unit.

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Docket No. PC3-045 · [0081] Immediately following flame extinction, a sample of the gas stream at a point near the lip of the cup is collected through a length of plastic tubing attached to a three way valve and multifit gas syringe. The sample is then subjected to gas chromatographic analysis (G.C.). G.C. calibration is performed by preparing standards samples in a 1L Tedlar® (E.I. DuPont De Nemours and Co. Corp., 1007 Market Street, Wilmington, Delaware) bag.

[0082] A summary of test parameters and results are shown below in Table 8.

TABLE 8

<td colspan="3"> Extinguishment of n-heptane Flames with CF3CHFCF2OCF3</td>

<td> Test</td><td> Primary Airflow (L/min)</td><td> CF3CHFCF2OCF3 % (v/v)</td>

<td> 1</td><td> 20.6</td><td> 4.97</td>

<td> 2</td><td> 20.6</td><td> 5.40</td>

<td> 3</td><td> 20.6</td><td> 5.38</td>

<td> 4</td><td> 20.6</td><td> 5.38</td>

<td> 5</td><td> 34.2</td><td> 4.90</td>

<td> 6</td><td> 41.1</td><td> 5.18</td>

<td> 7</td><td> 41.1</td><td> 5.13</td>

<td> 8</td><td> 41.1</td><td> 5.37</td>

<td> 9</td><td> 41.1</td><td> 5.40</td>

<td> 10</td><td> 41.1</td><td> 5.36</td>

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Docket No. PC3-045 [0083] Additional objects, advantages, and other novel features of the invention will become apparent to those skilled in the art upon examination of the foregoing or may be learned with practice of the invention. The foregoing description of the embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in the light of the above teachings. Embodiments were chosen and described to provide the best illustrations of the principals of the invention and their practical application, thereby enabling one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled.