[0001] This invention relates to fire extinguishing compositions comprising at least one
fluorinated ketone compound and at least one to co-extinguishing agent, and to systems
for extinguishing, controlling, or preventing fires using such compositions.
[0002] Various different agents and methods of fire extinguishing are known and can be selected
for a particular fire, depending upon its size and location, the type of combustible
materials involved, etc. Halogenated hydrocarbon fire extinguishing agents have traditionally
been utilized in flooding applications protecting fixed enclosures (e.g., computer
rooms, storage vaults, telecommunications switching gear rooms, libraries, document
archives, petroleum pipeline pumping stations, and the like), or in streaming applications
requiring rapid extinguishing (e.g., military flight lines, commercial hand-held extinguishers,
or fixed system local application). Such extinguishing agents are not only effective
but, unlike water, also function as "clean extinguishing agents," causing little,
if any, damage to the enclosure or its contents.
[0003] The most commonly-used halogenated hydrocarbon extinguishing agents have been bromine-containing
compounds, e.g., bromotrifluoromethane (CF
3Br, Halon
TM 1301) and bromochlorodifluoromethane (CF
2ClBr, Halon
TM 1211). Such bromine-containing halocarbons are highly effective in extinguishing
fires and can be dispensed either from portable streaming equipment or from an automatic
room flooding system activated either manually or by some method of fire detection.
However, these compounds have been linked to ozone depletion. The Montreal Protocol
and its attendant amendments have mandated that Halon
TM 1211 and 1301 production be discontinued (see, e.g.,
P. S. Zurer, "Looming Ban on Production of CFCs, Halons Spurs Switch to Substitutes,"
Chemical & Engineering News, page 12, November 15, 1993).
[0004] Thus, there has developed a need in the art for substitutes or replacements for the
commonly-used, bromine-containing fire extinguishing agents. Such substitutes should
have a low ozone depletion potential; should have the ability to extinguish, control,
or prevent fires or flames, e.g., Class A (trash, wood, or paper), Class B (flammable
liquids or greases), and/or Class C (electrical equipment) fires; and should be "clean
extinguishing agents," i.e., be electrically non-conducting, volatile or gaseous,
and leave no residue. Preferably, substitutes will also be low in toxicity, not form
flammable mixtures in air, have acceptable thermal and chemical stability for use
in extinguishing applications, and have short atmospheric lifetimes and low global
warming potentials. The urgency to replace bromofluorocarbon fire extinguishing compositions
is especially strong in the U.S. military (see, e.g.,
S. O. Andersen et al., "Halons, Stratospheric Ozone and the U.S. Air Force," The Military
Engineer, Vol. 80, No. 523, pp. 485-492, August, 1988). This urgency has continued throughout the 1990s (see
US Navy Halon 1211 Replacement Plan Part 1 - Development of Halon 1211 Alternatives,
Naval Research Lab, Washington, D.C., November 1, 1999).
[0005] Various different fluorinated hydrocarbons have been suggested for use as fire extinguishing
agents. However, to date, we are unaware that any fluorinated ketone having zero,
one, or two hydrogen atoms on the carbon backbone has been evaluated as a fire-fighting
composition.
[0006] In one aspect, this invention provides a fire extinguishing composition comprising:
- (a) at least one fluorinated ketone containing up to two hydrogen atoms and having
a boiling point of about 0°C to about 150°C; and
- (b) at least one co-extinguishing agent selected from the group consisting of hydrofluorocarbons,
hydrochlorofluorocarbons, hydrofluoroethers, hydrofluoropolyethers, chlorofluorocarbons,
bromofluorocarbons, bromochlorofluorocarbons, iodofluorocarbons, hydrobromofluorocarbons,
hydrobromocarbons, and mixtures thereof.
[0007] In a further aspect, the invention provides a system comprising the above composition
and means for introducing said composition to a fire.
[0008] In a further aspect, this invention provides a process for controlling or extinguishing
fires. The process comprises introducing to a fire or flame (e.g., by streaming or
by flooding) the above non-flammable extinguishing composition comprising at least
one fluorinated ketone compound containing up to two hydrogen atoms. Preferably, the
extinguishing composition is introduced in an amount sufficient to extinguish the
fire or flame. The fluorinated ketone compound can optionally contain one or more
catenated (i.e., "in-chain") oxygen, nitrogen or sulfur heteroatoms and has a boiling
point in the range of from about 0° C. to about 150° C.
[0009] The fluorinated ketone compounds used in the process of the invention are surprisingly
effective in extinguishing fires or flames while leaving no residue (i.e., function
as clean extinguishing agents). The compounds can be low in toxicity and flammability,
have no or very low ozone depletion potentials, and have short atmospheric lifetimes
and low global warming potentials relative to bromofluorocarbons, bromochlorofluorocarbons,
and many substitutes therefor (e.g., hydrochlorofluorocarbons, hydrofluorocarbons,
and perfluorocarbons). Since the compounds exhibit good extinguishing capabilities
and are also environmentally acceptable, they satisfy the need for substitutes or
replacements for the commonly-used bromine-containing fire extinguishing agents which
have been linked to the destruction of the earth's ozone layer.
[0010] In other aspects, this invention also provides a process for preventing fires in
enclosed areas.
[0011] The present invention also uses fluoroketones of the formula (CF
3)
2CFC(O)CF
2Cl and CF
3OCF
2CF
2C(O)CF(CF
3)
2 in fire extinguishing compositions which include such fluoroketones in amounts sufficient
to extinguish a fire.
[0012] Compounds that can be utilized in the processes and composition of the invention
are fluorinated ketone compounds. The compounds are utilized alone or in combination
with one another, and in combination with at least one other known extinguishing agent
selected from hydrofluorocarbons, hydrochlorofluorocarbons, hydrofluoropolyethers,
hydrofluoroethers, chlorofluorocarbons, bromofluorocarbons, bromochlorofluorocarbons,
hydrobromocarbons, iodofluorocarbons, and hydrobromofluorocarbons. The compounds can
be solids, liquids, or gases under ambient conditions of temperature and pressure,
but are preferably utilized for extinguishing in either the liquid or the vapor state
(or both). Thus, normally solid compounds are preferably utilized after transformation
to liquid and/or vapor through melting, sublimation, or dissolution in a liquid co-extinguishing
agent. Such transformation can occur upon exposure of the compound to the heat of
a fire or flame.
[0013] Fluorinated ketones useful in this invention are ketones which are fully fluorinated,
i.e., all of the hydrogen atoms in the carbon backbone have been replaced with fluorine;
or ketones which are folly fluorinated except for one or two hydrogen, chlorine, bromine
and/or iodine atoms remaining on the carbon backbone. Fire performance is compromised
when too many hydrogen atoms are present on the carbon backbone. For example, a fluorinated
ketone with three or more hydrogen atoms on the carbon backbone performs more poorly
than a ketone with the same fluorinated carbon backbone but having two, one or zero
hydrogen atoms, so that significantly more extinguishing composition of the former
is required to extinguish a given fire. The fluoroketones may also include those that
contain one or more catenated heteroatoms interrupting the carbon backbone in the
perfluorinated portion of the molecule. A catenated heteroatom is, for example, a
nitrogen, oxygen or sulfur atom.
[0014] Preferably, the majority of halogen atoms attached to the carbon backbone are fluorine;
most preferably, all of the halogen atoms are fluorine so that the ketone is a perfluorinated
ketone. More preferred fluorinated ketones have a total of 4 to 8 carbon atoms. Representative
examples of perfluorinated ketone compounds suitable for use in the processes and
compositions of the invention include CF
3CF
2C(O)CF(CF
3)
2, (CF
3)
2CFC(O)CF(CF
3)
2, CF
3(CF
2)
2C(O)CF(CF
3)
2, CF
3(CF
2)
3C(O)CF(CF
3)
2, CF
3(CF
2)
5C(O)CF
3, CF
3CF
2C(O)CF
2CF
2CF
3, CF
3C(O)CF(CF
3)
2 and perfluorocyclohexanone.
[0015] In addition to demonstrating excellent fire-fighting performance, the fluorinated
ketones offer important benefits in environmental friendliness and can offer additional
important benefits in toxicity. For example, CF
3CF
2C(O)CF(CF
3)
2 has low acute toxicity, based on short term inhalation tests with mice exposed for
four hours at a concentration of 50,000 ppm in air. Based on photolysis studies at
300 nm, CF
3CF
2C(O)CF(CF
3)
2 has an estimated atmospheric lifetime of 3 to 5 days. Other fluorinated ketones show
similar absorbances and are expected to have similar atmospheric lifetimes. As a result
of their rapid degradation in the lower atmosphere, the perfluorinated ketones have
short atmospheric lifetimes and would not be expected to contribute significantly
to global warming.
[0016] Fluorinated ketones can be prepared by known methods, e.g., by dissociation of perfluorinated
carboxylic acid esters by reacting the perfluorinated ester with a source of fluoride
ion under reacting conditions, as described in
U.S. Patent No. 5,466,877 (Moore et al.), by combining the ester with at least one initiating reagent selected from the group
consisting of gaseous, non-hydroxylic nucleophiles; liquid, non-hydroxylic nucleophiles;
and mixtures of at least one non-hydroxylic nucleophile (gaseous, liquid, or solid)
and at least one solvent which is inert to acylating agents. The fluorinated carboxylic
acid ester precursors can be derived from the corresponding fluorine-free or partially
fluorinated hydrocarbon esters by direct fluorination with fluorine gas as described
in
U.S. Patent No. 5,399,718 (Costello et al.).
[0017] Fluorinated ketones that are alpha-branched to the carbonyl group can be prepared
as described in, for example,
U.S. Patent No. 3,185,734 (Fawcett et al.) and
J. Am. Chem. Soc., v. 84, pp. 4285-88, 1962. These branched fluorinated ketones are most conveniently prepared by hexafluoropropylene
addition to acyl halides in an anhydrous environment in the presence of fluoride ion
at an elevated temperature, typically at around 50 to 80°C. The diglyme/fluoride ion
mixture can be recycled for subsequent fluorinated ketone preparations, e.g., to minimize
exposure to moisture. When this reaction scheme is employed, a small amount of hexafluoropropylene
dimer and/or trimer may reside as a by-product in the branched perfluoroketone product.
The amount of dimer and/or trimer may be minimized by gradual addition of hexafluoropropylene
to the acyl halide over an extended time period, e.g., several hours. These dimer
and/or trimer impurities can usually be removed by distillation from the perfluoroketone.
In cases where the boiling points are too close for fractional distillation, the dimer
and/or trimer impurity may be conveniently removed in an oxidative fashion by treating
the reaction product with a mixture of an alkali metal permanganate in a suitable
organic solvent such as acetone, acetic acid, or a mixture thereof at ambient or elevated
temperatures, preferably in a sealed vessel. Acetic acid is a preferred solvent for
this purpose; it has been observed that acetic acid tends not to degrade the ketone
whereas in some instances some degradation of the ketone was noted when acetone was
used. The oxidation reaction is preferably carried out at an elevated temperature,
i.e., above room temperature, preferably from about 40°C or higher, to accelerate
the reaction. The reaction can be carried out under pressure, particularly if the
ketone is low boiling. The reaction is preferably carried out with agitation to facilitate
complete mixing of two phases which may not be totally miscible.
[0018] When relatively volatile, short-chain acyl halides are employed (e.g., acyl halides
containing from two to about five carbon atoms) in the hexafluoropropylene addition
reaction; significant pressure build-up can occur in the reactor at elevated reaction
temperatures (e.g., at temperatures ranging from about 50°C to about 80°C). It has
been discovered that this pressure build-up can be minimized if only a fraction of
the acyl halide charge (e.g., about 5 to 30 percent) is initially added to the reactor
and the remaining portion of acyl halide is co-charged with the hexafluoropropylene
continuously or in small increments (preferably in an equimolar ratio) over an extended
time period (e.g., 1 to 24 hours, depending in part upon the size of the reactor).
The initial acyl halide charge and the subsequent co-feeding to the reactor also serves
to minimize the production of by-product hexafluoropropylene dimers and/or trimers.
The acyl halide is preferably an acyl fluoride and may be perfluorinated (e.g., CF
3COF, C
2F
5COF, C
3F
7COF), may be partially fluorinated (e.g., HCF
2CF
2COF), or may be unfluorinated (e.g., C
2H
5COF), with the product ketone formed being perfluorinated or partially fluorinated.
The perfluoroketones may also include those that contain one or more catenated heteroatoms
interrupting the carbon backbone in the perfluorinated portion of the molecule, such
as, for example, a nitrogen, oxygen or sulfur atom.
[0019] Perfluorinated ketones which may be linear can be prepared according to the teachings
of
U.S. Pat. No. 4,136,121 (Martini et al.) by reacting a perfluorocarboxylic acid alkali metal salt with a perfluorinated acid
fluoride. Such ketones can also be prepared according to the teachings of
U.S. Pat. No. 5,998,671 (Van Der Puy) by reacting a perfluorocarboxylic acid salt with a perfluorinated acid anhydride
in an aprotic solvent at elevated temperatures.
[0020] The extinguishing process of the invention can be carried out by introducing a non-flammable
extinguishing composition comprising at least one fluorinated ketone compound and
at least one co-extinguishing agent to a fire or flame. The fluorinated ketone compounds)
are utilized alone or in a mixture with each other, and with other commonly used clean
extinguishing agents, selected from hydrofluorocarbons, hydrochlorofluorocarbons,
hydrofluoroethers, hydrofluoropolyethers, chlorofluorocarbons, bromofluorocarbons,
bromochlorofluorocarbons, hydrobromocarbons, iodofluorocarbons, and hydrobromofluorocarbons.
Such co-extinguishing agents can be chosen to enhance the extinguishing capabilities
or modify the physical properties (e.g., modify the rate of introduction by serving
as a propellant) of an extinguishing composition for a particular type (or size or
location) of fire and can preferably be utilized in ratios (of co-extinguishing agent
to fluorinated ketone compound(s)) such that the resulting composition does not form
flammable mixtures in air. Preferably, the extinguishing mixture contains from about
10-90% by weight of at least one fluorinated ketone and from about 90-10% by weight
of at least one co-extinguishing agent. The fluorinated ketone compound(s) used in
the composition has a boiling points in the range of from about 0° C to about 150°
C, preferably from about 0° C to about 110° C.
[0021] The extinguishing composition can preferably be used in either the gaseous or the
liquid state (or both), and any of the known techniques for introducing the composition
to a fire can be utilized. For example, a composition can be introduced by streaming,
e.g., using conventional portable (or fixed) fire extinguishing equipment; by misting;
or by flooding, e.g., by releasing (using appropriate piping, valves, and controls)
the composition into an enclosed space surrounding a fire or hazard. The composition
can optionally be combined with inert propellant, e.g., nitrogen, argon, or carbon
dioxide, to increase the rate of discharge of the composition from the streaming or
flooding equipment utilized. When the composition is to be introduced by streaming
or local application, fluorinated ketone compound(s) having boiling points in the
range of from about 20° C to about 110° C (especially fluorinated ketone compounds
which are liquid under ambient conditions) can preferably be utilized. When the composition
is to be introduced by misting, fluorinated ketone compound(s) having boiling points
in the range of from about 20° C to about 110° C are generally preferred. And, when
the composition is to be introduced by flooding, fluorinated ketone compound(s) having
boiling points in the range of from about 0° C to about 75° C (especially fluorinated
ketone compound(s) which are gaseous under ambient conditions) are generally preferred.
[0022] Preferably, the extinguishing composition is introduced to a fire or flame in an
amount sufficient to extinguish the fire or flame. One skilled in the art will recognize
that the amount of extinguishing composition needed to extinguish a particular fire
will depend upon the nature and extent of the hazard. When the extinguishing composition
is to be introduced by flooding, cup burner test data (e.g., of the type described
in the Examples, infra) can be useful in determining the amount or concentration of
extinguishing composition required to extinguish a particular type and size of fire.
[0023] This invention also provides an extinguishing composition comprising (a) at least
one fluorinated ketone compound; and (b) at least one co-extinguishing agent selected
from the group consisting of hydrofluorocarbons, hydrochlorofluorocarbons, hydrofluoroethers,
hydrofluoropolyethers, chlorofluorocarbons, bromofluorocarbons, bromochlorofluorocarbons,
iodofluorocarbons, hydrobromofluorocarbons, and hydrobromocarbons. Representative
examples of co-extinguishing agents which can be used in the extinguishing composition
include CF
3CH
2CF
3, C
5F
11H, C
6F
13H, C
4F
9H, CF
3CFHCFHCF
2CF
3, H(CF
2)
4H, CF
3H, C
2F
5H, CF
3CFHCF
3, CF
3CF
2CF
2H, CF
3CHCl
2, CF
3CHClF, CF
3CHF
2, C
3F
7OCH
3, C
4F
9OCH
3, F(C
3F
6O)CF
2H, F(C
3F
6O)
2CF
2H, HCF
2O(CF
2CF
20)CF
2H, HCF
2O(CF
2CF
2O)
2CF
2H, HCF2O(CF
2O)(CF
2CF
2O)CF
2H, C
2F
5Cl, CF
3Br, CF
2ClB
r, CF
3I, CF
2HBr,
n-C
3H
7Br, and CF
2BrCF
2Br. (For a representative listing of known clean extinguishing agents, see
NFPA 2001, "Standard for Clean Agent Fire Extinguishing Systems," 2000 Edition, Table
1-5.1.2, p. 2001-5.) The ratio of co-extinguishing agent to fluorinated ketone is preferably such that
the resulting composition does not form flammable mixtures in air (as defined by standard
test method ASTM E681-85). The weight ratio of co-extinguishing agent to fluorinated
ketone may vary from about 9:1 to about 1:9.
[0024] These fluorinated ketone compositions can be utilized in co-application processes
with not-in-kind fire-fighting technologies to provide enhanced extinguishing capabilities.
For example, the liquid composition CF
3CF
2C(O)CF(CF
3)
2 can be introduced into an aqueous film forming foam (AFFF) solution stream, for example,
utilizing a Hydro-Chem
TM nozzle manufactured by Williams Fire & Hazard Control, Inc., Mauriceville, TX to
give the AFFF three-dimensional fire-fighting capability. The AFFF can carry the CF
3CF
2C(O)CF(CF
3)
2 a much longer distance than it could be delivered by itself to a remote three dimensional
fuel fire, allowing the CF
3CF
2C(O)CF(CF
3)
2 to extinguish the three-dimensional fuel fire where the AFFF stream by itself would
not.
[0025] Another co-application process utilizing fluorinated ketones can be extinguishing
a fire using a combination of a gelled halocarbon with dry chemical. A dry chemical
can be introduced in suspension in the liquid CF
3CF
2C(O)CF(CF
3)
2 and discharged from a manual handheld extinguisher or from a fixed system.
[0026] Yet another co-application process utilizing fluorinated ketones is the process where
the fluorinated ketone is super-pressurized upon activation of a manual hand-held
extinguisher or a fixed system using an inert off-gas generated by the rapid burning
of an energetic material such as glycidyl azide polymer. In addition, rapid burning
of an energetic material such as glycidyl azide polymer that yields a hot gas can
be used to heat and gasify a liquid fluorinated ketone of the invention or other liquid
fire extinguishing agent to make it easier to disperse. Furthermore, an unheated inert
gas (e.g., from rapid burning of an energetic material) might be used as to propel
liquid fluorinated ketones of the invention or other liquid fire extinguishing agents
to facilitate dispersal.
[0027] The above-described fluorinated ketone compounds can be useful not only in controlling
and extinguishing fires but also in preventing the combustible material from igniting.
The invention thus also provides a process for preventing fires or deflagration in
an air-containing, enclosed area which contains combustible materials of the self-sustaining
or non-self-sustaining type. The process comprises the step of introducing into an
air-containing, enclosed area a non-flammable extinguishing composition which is essentially
gaseous, i.e., gaseous or in the form of a mist, under use conditions and which comprises
at least one fluorinated ketone compound containing up to two hydrogen atoms, optionally
up to two halogen atoms selected from chlorine, bromine, iodine, and a mixture thereof,
and optionally containing additional catenated heteroatoms, and the composition being
introduced and maintained in an amount sufficient to impart to the air in the enclosed
area a heat capacity per mole of total oxygen present that will suppress combustion
of combustible materials in the enclosed area.
[0028] Introduction of the extinguishing composition can generally be carried out by flooding
or misting, e.g., by releasing (using appropriate piping, valves, and controls) the
composition into an enclosed space surrounding a fire. However, any of the known methods
of introduction can be utilized provided that appropriate quantities of the composition
are metered into the enclosed area at appropriate intervals. Inert propellants, such
as those propellants generated by decomposition of energetic materials such as glycidyl
azide polymers, can optionally be used to increase the rate of introduction.
[0029] For fire prevention, fluorinated ketone compound(s) (and any co-extinguishing agent(s)
utilized) can be chosen so as to provide an extinguishing composition that is essentially
gaseous under use conditions. Preferred compound(s) have boiling points in the range
of from about 0° C to about 110° C.
[0030] The composition is introduced and maintained in an amount sufficient to impart to
the air in the enclosed area a heat capacity per mole of total oxygen present that
will suppress combustion of combustible materials in the enclosed area. The minimum
heat capacity required to suppress combustion varies with the combustibility of the
particular flammable materials present in the enclosed area. Combustibility varies
according to chemical composition and according to physical properties such as surface
area relative to volume, porosity, etc.
[0031] In general, a minimum heat capacity of about 45 cal/°C per mole of oxygen is adequate
to extinguish or protect moderately combustible materials (e.g., wood and plastics),
and a minimum of about 50 cal/°C per mole of oxygen is adequate to extinguish or protect
highly combustible materials (e.g., paper, cloth, and some volatile flammable liquids).
Greater heat capacities can be imparted if desired but may not provide significantly
greater fire suppression for the additional cost involved. Methods for calculating
heat capacity (per mole of total oxygen present) are well-known (see, e.g., the calculation
described in
U.S. Patent No. 5,040,609 (Dougherty et al.).
[0032] The fire prevention process of the invention can be used to eliminate the combustion-sustaining
properties of air and to thereby suppress the combustion of flammable materials (e.g.,
paper, cloth, wood, flammable liquids, and plastic items). The process can be used
continuously if a threat of fire always exists or can be used as an emergency measure
if a threat of fire or deflagration develops.
[0033] Objects and advantages of this invention are further illustrated by the following
examples, but the particular materials and amounts thereof recited in these examples,
as well as other conditions and details, should not be construed to unduly limit this
invention. Unless otherwise specified, all percentages and proportions are by weight,.
Examples
Example 1. CF3CF2C(O)CF(CF3)2 - 1,1 1 ,2,2,4,5,5,5-nonafluoro-4-trifluoromethyl-pentane-3-one
[0034] Into a clean dry 600 mL Parr reactor equipped with stirrer, heater and thermocouple
were added 5.6 g (0.10 mol) of anhydrous potassium fluoride and 250 g of anhydrous
diglyme (anhydrous diethylene glycol dimethyl ether, available from Sigma Aldrich
Chemical Co. used in all subsequent syntheses). The anhydrous potassium fluoride used
in this synthesis, and in all subsequent syntheses, was spray dried, stored at 125°C
and ground shortly before use. The contents of the reactor were stirred while 21.0
g (0.13 mol) of C
2F
5COF (approximately 95.0 percent purity) was added to the sealed reactor. The reactor
and its contents were then heated, and when a temperature of 70°C had been reached,
a mixture of 147.3 g (0.98 mol) of CF
2=CFCF
3 (hexafluoropropylene) and 163.3 g (0.98 mol) of C
2F
5COF was added over a 3.0 hour time period. During the addition of the hexafluoropropylene
and the C
2F
5COF mixture, the pressure was maintained at less than 95 psig (7500 torr). The pressure
at the end of the hexafluoropropylene addition was 30 psig (2300 torr) and did not
change over the 45-minute hold period. The reactor contents were allowed to cool and
were one-plate distilled to obtain 307.1 g containing 90.6% 1,1,1,2,2,4,5,5,5-nonafluoro-4-trifluoromethyl-pentane-3-one
and 0.37% C
6F
12 (hexafluoropropylene dimer) as determined by gas chromatography. The crude fluorinated
ketone was water-washed, distilled, and dried by contacting with silica gel to provide
a fractionated fluorinated ketone of 99% purity and containing 0.4% hexafluoropropylene
dimers.
Example 1A.
[0035] A fractionated fluorinated ketone made according to the same procedures as in Example
1 was purified of dimers using the following procedure. Into a clean dry 600 mL Parr
reactor equipped with stirrer, heater and thermocouple were added 61 g of acetic acid,
1.7 g of potassium permanganate, and 301 g of the above-described fractionated 1,1,1,2,2,4,5,5,5-nonafluoro-4-trifluoromethyl-pentane-3-one.
The reactor was sealed and heated to 60°C, while stirring, reaching a pressure of
12 psig (1400 torr). After 75 minutes of stirring at 60°C, a liquid sample was taken
using a dip tube, the sample was phase split and the lower phase was washed with water.
The sample was analyzed using glc and showed undetectable amounts of hexafluoropropylene
dimers and small amounts of hexafluoropropylene trimers. A second sample was taken
60 minutes later and was treated similarly. The glc analysis of the second sample
showed no detectable dimers or trimers. The reaction was stopped after 3.5 hours,
and the purified ketone was phase split from the acetic acid and the lower phase was
washed twice with water. 261 g of the ketone was collected, having a purity greater
than 99.6% by glc and containing no detectable hexafluoropropylene dimers or trimers.
Example 1B.
[0036] The following example was run to demonstrate the use of KMnO
4/acetic acid to purify C
2F
5COCF(CF
3)
2, made according to the teachings set forth in Example 1, which contained a high concentration
(about 5%) of hexafluoropropylene dimers.
[0037] Into a clean dry 600 mL Parr reactor equipped with a stirrer, heater and thermocouple
were added 60 g of acetic acid, 30 g of potassium permanganate and 286 g of the fluorinated
ketone, C
2F
5COCF(CF
3)
2 (94% purity, containing about 5.2% dimers of hexafluoropropylene). The contents of
the reactor were held at 60°C for 25 hours to ensure that all of the dimers had been
oxidized. While holding at 60°C, the reactor pressure continued to rise until a final
pressure of 70 psig (4400 torr) was reached. The fluorinated ketone was distilled
from the acetic acid, 255 g was collected, and the distilled ketone was washed twice
with water. Ultimately, 242 g of the ketone was collected, having a purity of greater
than 99.1% with no detectable hexafluoropropylene dimers or trimers (by glc).
Example 1C.
[0038] The following example was run to demonstrate the use of KMnO
4/acetone to purify C
2F
5COCF(CF
3)
2, made according to the teachings set forth in Example 1, which contained a very high
concentration (about 20%) of hexafluoropropylene dimers.
[0039] A two liter three-necked round bottom flask was equipped with an overhead air stirrer,
water condenser and addition funnel. 360 g of acetone and 78 g (0.49 mol) of potassium
permanganate were placed in the flask and the contents cooled to about 18°C. 357 g
(0.90 mol) of C
2F
5COCF(CF
3)
2 (80% purity and containing about 20% hexafluoropropylene dimers, made according to
the general procedure described in Example 1), was added slowly dropwise to the cooled
contents. After the addition was complete, the resulting solution was stirred for
about two hours at room temperature. A small amount (about 10 mL) of water was added,
followed by the addition of just enough aqueous saturated sodium bisulfite solution
to completely decolorize the acetone solution and dissolve the brown manganese dioxide
precipitate. Additional water was added to give a clean phase separation, and the
lower phase was separated and washed again with an equal volume of water to give 138
g of product. This product was combined with the product of an earlier experiment
(198 g), and the combined product, which still contained acetone, was treated with
80 mL of concentrated sulfuric acid by addition of the acid through the top of a water
cooled condenser to the product contained in a water bath-cooled round bottom flask.
The ketone was then distilled from the combined product/sulfuric acid mixture as an
azeotrope with the residual acetone. The resulting distillate contained two phases
which were separated, and the lower phase was washed again with deionized water to
provide 138 g of C
2F
5COCF(CF
3)
2 in a purity of 99.7% and which contained no hexafluoropropylene dimers nor any acetone
as determined by glc.
Example 2. (CF3)2CFC(O)CF(CF3)2 - 1,1,1,2,4,5,5,5,6,6,6-octafluoro-2,4-bis(trifluoromethyl)pentan-3-one
[0040] 8.1 g (0.14 mol) of anhydrous potassium fluoride, 216 g (0.50 mol) of perfluoro(isobutyl
isobutyrate) and 200 grams of anhydrous diglyme were charged to a clean dry 600 mL
Parr pressure reactor. After cooling the reactor to < 0° C, 165 g (1.10 mol) of hexafluoropropylene
was added to the resulting mixture. The contents in the reactor were allowed to react
overnight at 70° C with stirring, then the reactor was allowed to cool and the excess
pressure in the reactor was vented to the atmosphere. The contents of the reactor
were then phase split to obtain 362.5 g of lower phase. The lower phase was retained
and mixed with lower phases saved from previous analogous reactions. To 604 g of accumulated
lower phases containing 22% perfluoroisobutyryl fluoride and 197 g (1.31 mol) of hexafluoropropylene
was added 8 g (0.1 mol) of anhydrous potassium fluoride and 50 g of anhydrous diglyme,
and the resulting mixture was allowed to react in the Parr reactor in the same manner
as before. This time 847 g of lower phase resulted, containing 54.4% desired material
and only 5.7% perfluoroisobutyryl fluoride. The lower phase was then water washed,
dried with anhydrous magnesium sulfate, and fractionally distilled to give 359 g of
1,1,1,2,4,5,5,5,6,6,6-octafluoro-2,4-bis(trifluoromethyl)pentan-3-one having 95.2%
purity as determined by gas chromatography and mass spectroscopy ("gcms") (47% theoretical
yield) and having a boiling point of 73°C.
Example 3. 65% (CF3)2CFC(O)CF(CF3)2, 35% CF3CF2CF2C(O)CF(CF3)2 - a blend of compounds from Examples 2 and 7, respectively
Example 4. CF3CF2CF2CF2CF2CF2C(O)CF3 - 1,1,1,3,3,4,4,5,5,6,6,7,7,8,8,8-hexadecafluorooctan-2-one
[0041] 1052 mL of 2-octyl acetate was converted to the perfluorinated ester via direct fluorination
as described in
U.S. Patent No. 5,488,142 (Fall et al.). The resulting perfluorinated ester was treated with methanol to convert it to the
hemiketal to allow distillation of the reaction solvent. 1272 g of the resulting hemiketal
was slowly added to 1200 mL of concentrated sulfuric acid, and the resulting reaction
mixture was re-fractionated to yield 1554.3 g of 1,1,1,3,3,4,4,5,5,6,6,7,7,8,8,8-hexadecafluoro-octan-2-one,
having a boiling point of 97°C and having a purity of 98.4% as measured by nuclear
magnetic resonance spectroscopy.
Example 5. CF3C(O)CF(CF3)2 - 1,1,1,3,4,4,4-heptafluoro-3-trifluoromethylbutan-2-one
[0042] A mixture consisting of 421 g of trifluoroacetic anhydride, 319.5 g of anhydrous
diglyme, 131 g of anhydrous potassium fluoride and 315 g of hexafluoropropylene was
heated in a 3-liter HASTELLOY
TM (Haynes, Inc., Kokomo, IN) pressure vessel under autogenous pressure at 50°C for
16 hours. The gaseous product was fractionally distilled to give 319.1 g of 1,1,1,3,4,4,4-heptafluoro-3-trifluoromethyl-butan-2-one
having a boiling point of 25°C. Purity was 99.6% as determined by gas chromatography.
The structure was verified using nuclear magnetic resonance spectroscopy.
Example 6. HCF2CF2C(O)CF(CF3)2 - 1,1,1,2,4,4,5,5-octafluoro-2-trifluoromethylpentan-3-one
[0043] Into a one liter three-necked round bottom flask equipped with an overhead stirrer,
condenser and addition funnel were charged 315 g (1.07 mol) of potassium dichromate
and 442 g of water. To this mixture was added 212 g of concentrated sulfuric acid
in portions so that the temperature of the reaction mixture reached 54°C by the end
of the acid addition. The reaction mixture was then heated to 88°C, and 141.2 g (1.07
mol) of tetrafluoropropanol was slowly added dropwise, which warmed the contents to
102°C during the course of the addition. Following the addition the reaction temperature
was held at 102°C for two hours. The resulting aqueous solution was then separated
into two portions, and each portion was extracted twice with about 170 g of diethyl
ether. The two aqueous portions were recombined, and a final extraction of the entire
aqueous solution was then carried out using 205 g of diethyl ether. The ether solution
portions were combined and the combined portions were then neutralized and extracted
by vigorous stirring with 100 g of 40% aqueous potassium hydroxide. The ether layer
was discarded and the water was removed from the dark blue aqueous layer by heating
at 50-60°C under aspirator vacuum until nearly dry. Hexane was added and distilled
off to azeotropically remove the last residue of water from the chromium salt. About
700 mL of denatured alcohol was added to the mixture, and the resulting mixture was
heated to reflux for two hours with stirring. The residual chromium salts were removed
from the alcohol solution via filtration, and the light yellow filtrate was evaporated
to dryness. This filtrate residue was then carefully treated with concentrated sulfuric
acid, and the resulting acid was removed by distillation from the sulfuric acid. 127
g of the acid, HC
2F4C0
2H, was recovered having a boiling point of 132-134°C.
[0044] The entire recovered acid product was treated with 264 g (1.35 mol) of benzotrichloride,
and the resulting mixture was heated to 70°C for 19 hours. Some of the desired acid
chloride product, HC
2F
4C(O)Cl, distilled from the reaction mixture during this time and was collected in
an ice water-cooled trap. The contents of the trap were combined with the reaction
mixture and were distilled to yield 70g of acid chloride having 95% purity as determine
by glc, and having a (C=O) stretch of 1795 cm -1 as determined by infrared spectroscopy.
This product was used without further purification in the next step.
[0045] In order to convert the carbonyl chloride to carbonyl fluoride, 65 g (0.375 mole)
of HC
2F
4C(O)Cl was added dropwise to 60 g of anhydrous sodium fluoride (dried at 125°C for
one hour) in 150 mL of freshly distilled anhydrous sulfolane at 60°C. During this
dropwise addition the desired acid fluoride product distilled from the reaction mixture
and was collected using a dry ice cooled condenser. After the end of the addition
the flask was heated to 70°C for one hour to complete the removal of the acid fluoride,
resulting in the recovery of 35 g of HC
2F
4C(O)F having greater than 99% purity as determined by glc.
[0046] The final ketone product, 1,1,1,2,4,4,5,5-octafluoro-2-trifluoromethylpentan-3-one,
was prepared by fluoride-catalyzed addition of hexafluoropropylene to HC
2F
4C(O)F using essentially the same procedure as described by
R D. Smith et al. in J. Am. Chem. Soc., 84, 4285 (1962). The resulting fluorinated ketone product had a boiling point of 70-71 °C.
Example 7. CF3CF2CF2C(O)CF(CF3)2 - 1,1,1,2,4,4,5,5,6,6,6-undecafluoro-2-trifluoromethylhexan-3-one
[0047] Into a clean dry 600 mL Parr reactor equipped with stirrer, heater and thermocouple
were added 5.8 g (0.10 mol) of anhydrous potassium fluoride and 108 g of anhydrous
diglyme. The contents of the reactor were stirred and cooled with dry ice while 232.5
g (1.02 mol) of n-C
3F
7COF (approximately 95.0 percent purity) was added to the sealed reactor. The reactor
and its contents were then heated, and when a temperature of 72°C had been reached,
141 g (0.94 mol) of CF
2=CFCF
3 (hexafluoropropylene) was added at a pressure of 85 psig (5150 torr) over a 3.25
hour time period. During the addition of hexafluoropropylene the temperature of the
reactor was increased slowly to 85°C while maintaining the pressure at less than 90
psig (5400 torr). The pressure at the end of the hexafluoropropylene addition was
40 psig (2800 torr) and did not change over an additional 4-hour hold period. The
lower phase was fractionally distilled to give 243.5 grams of 1,1,1,2,4,4,5,5,6,6,6-undecafluoro-2-trifluoromethylhexan-3-one,
having a boiling point of 72.5°C and a purity of 99.9% as determined by gas chromatography.
The structure was confirmed by gcms.
Example 8. (CF3)2CFC(O)CF2Cl - 1-chloro-1,1,3,4,4,4-hexafluoro-3-trifluoromethyl-butan-2-one
[0048] To a clean dry 600 mL Parr pressure reactor was charged 53.5 g (0.92 mol) of anhydrous
potassium fluoride, 150 g of anhydrous diglyme and 150 g of chlorodifluoroacetic anhydride.
With the reactor set at 80°C and 92 psig (5500 torr), 123 g (0.820 mol) of hexafluoropropylene
was charged over a 3 hour period at a tank pressure not exceeding 120 psig (7000 torr).
Following reaction for ½ hour at 80°C, the reactor contents were allowed to cool and
were distilled to obtain 180.6 g of crude material. Upon fractional distillation,
acetic acid/KMnO
4 treatment and refractionation of the crude material, 46.1 g (26% of theoretical yield)
of (CF
3)
2CFC(O)CF
2Cl, a clear colorless liquid, was obtained having a purity of 98.8% as determined
by gas chromatography.
Example 9. CF3CF2C(O)CF2CF2CF3 - 1,1,1,2,2,4,4,5,5,6,6,6-dodecafluorohexan-3-one
[0049] 545 g of 3-hexyl acetate was fluorinated using essentially the same procedure as
described in
U.S. Patent No. 5,488,142 (Fall et al.). 1031 g of the resulting perfluorinated ester was then converted to the ketone,
using essentially the same procedure as described in Example 13 (i.e., for the preparation
of CF
3C(O)CF
2CF
3). The crude ketone was fractionally distilled from concentrated sulfuric acid to
give 90 g of 1,1,1,2,2,4,4,5,5,6,6,6-dodecafluorohexan-3-one, having a boiling point
of 50°C and having a purity of 98.7% as determined by gcms.
Example 10. CF3C(O)CH2C(O)CF3 - 1,1,1,5,5,5-hexafluoropentan-2,4-dione
[0050] This diketone is available from Sigma Aldrich Chemical Co .
Example 11. (CF3)2CFC(O)C(O)CF(CF3)2 - 1,1,1,2,5,6,6,6-octafluoro-2,5-bis(trifluoromethyl)hexan-3,4-dione
[0051] Perfluorodibutyl oxalate was prepared from direct fluorination of dibutyl oxalate
using essentially the same procedure as described in
U.S. Patent No. 5,488,142 (Fall et al.). A mixture of 1002 g of perfluorodibutyl oxalate, 1008 g of anhydrous diglyme, 40.4
g of anhydrous potassium fluoride and 806 g of hexafluoropropylene was heated in a
3-liter HASTELLOY
TM pressure vessel under autogenous pressure with stirring for 16 hours at 50°C. The
resulting reaction . product was fractionated to produce 1,1,1,2,5,6,6,6-octafluoro-2,5-bis-trifluoromethyl-hexan-3,4-dione,
having a boiling point of 92°C and having a purity of 93.4% as measured by gas chromatography
and mass spectroscopy.
Example 12. CF3CF2CF2C(O)CF2CF2CF3 - 1,1,1,2,2,3,3,5,5,6,6,7,7,7-tetradecafluoroheptan-4-one
[0052] This linear ketone can be prepared using essentially the same procedure as described
in
U.S. Pat. No 4,136,121 (Martini et al.), for example, by reacting CF
3CF
2CF
2COO
-K
+ with CF
3CF
2CF
2COF in tetraethylene glycol dimethyl ether for about 60 hours at a temperature of
about 100°C.
Example 13. CF3C(O)CF2CF3 - 1,1,1,3,3,4,4,4-octafluorobutan-2-one
[0053] 1341 g of
sec-butyl acetate was fluorinated using essentially the same procedure as described in
U.S. Patent No. 5,488,142 (Fall et al.). The resulting perfluorinated ester (688 g) was isolated from the reaction mixture
by fractionation. The ester was then decomposed according to the method described
by Moore in
U.S. Pat. No. 5,466,877 wherein the ester was added dropwise to a 1-liter, 3-neck flask equipped with a magnetic
stirrer, dry ice condenser and temperature probe containing 0.5 mL of pyridine. The
pot temperature was maintained at about -10°C, during which time the conversion to
the ketone occurred. The gaseous ketone product was fractionated to give 435 g. of
1,1,1,3,3,4,4,4-octafluoro-butan-2-one, having a boiling point of 0°C, with purity
of 99.7% as determined by gas chromatography and mass spectroscopy.
Example 14. CF3OCF2CF2C(O)CF(CF3)2 - 1,1,2,2,4,5,5,5-octafluoro-1-trifluoromethoxy-4-trifluoromethylpentan-3-one
[0054] Into a clean dry 600 mL Parr reactor were added 11.6 g (0.20 mol) of anhydrous potassium
fluoride and 113.5 g of anhydrous diglyme. The contents of the reactor were stirred
and cooled with dry ice, then 230 g (0.96 mol) of CF
3OCF
2CF
2COF (approximately 97 percent purity) was added to the sealed reactor using isolated
vacuum. With the reactor at 80° C and pressure of 80 psig (4900 torr), 154 g (1.03
mol) of CF
2=CFCF
3 was gradually added over a 3
1/
2 hour time period. Following a one hour reaction hold time, the product was recovered
from the reaction mixture by distillation and phase split prior to fractionation to
give 100 g of 1,1,2,2,4,5,5,5-octalluoro-1-trilluoromethoxy-4-trifluoromethylpentan-3-one,
having a boiling point of 77° C and a purity of 99.8% as determined by gas chromatography.
The structure was confirmed by gas chromatography and mass spectroscopy.
Example 15.
[0055]
[0056] 2500 mL of cyclohexyl acetate was converted to the perfluorinated ester via direct
fluorination using 1,1,2-trichlorotrifluoroethane as the reaction medium as described
in
U.S. Patent No. 5,399,718 (Costello et al.). Methanol was added to the reaction mixture to convert the perfluorinated ester
to the corresponding hemiketal. The mixture was then fractionated to isolate the hemiketal
from the 1,1,2-trichlorotrifluoroethane. 1686 g of the purified hemiketal was slowly
added to 1800 mL of concentrated sulfuric acid and was re-fractionated to give 1054
g decafluorocyclohexanone having a boiling point of 53°C and having a purity of greater
than 95% as determined by gas chromatography (55.7% yield). The structure was confirmed
by nuclear magnetic resonance spectroscopy.
Example 16. CF3CF2CF2CF2C(O)CF(CF3)2 - 1,1,1,2,4,4,5,5,6,6,7,7,7-tridecafluoro-2-trifluoromethylheptan-3-one
[0057] A mixture consisting of 775 g of perfluoropentanoyl fluoride, 800 g of anhydrous
diglyme, 13.1 g of potassium fluoride, 17.8 g of anhydrous potassium bifluoride and
775 g of hexafluoropropylene was heated in a 3-liter stainless steel pressure vessel
under autogeneous pressure at 50°C for 16 hours. The product was fractionally distilled
to give 413 g of 1,1,1,2,4,4,5,5,6,6,7,7,7-tridecafluoro-2-trifluoromethyl-heptan-3-one,
having a boiling point of 97°C and a 99.0% purity as determined by gas chromatography
and mass spectroscopy.
Comparative Example C1. CF2ClBr - bromochlorodifluoromethane
[0058] This manufacture of this product, commercially known as HALON™ 1211 fire extinguishing
agent, was commercially phased out as of January 1, 1994 in countries signatory to
Montreal Protocol.
Comparative Example C2. CF3I - iodotrifluoromethane
[0059] This compound is available as TRIODIDE™ fire extinguishing agent from Pacific Scientific,
Carpinteria, CA.
Comparative Example C3. CF3CH2CF3 - 1,1,1,3,3,3-hexafluoropropane
[0060] This compound is available as FE-36™ fire extinguishing agent from E. I. duPont de
Nemours & Co., Wilmington, DE.
Comparative Example C4
[0061] This mixture is an 80/20 blend of
CF3CHCl2 (HCFC-123 or 2,2-dichloro-1,1,1-trifluoroethane - available from Sigma Aldrich Chemical
Co.) and
CF4 (tetrafluoromethane - available from Sigma Aldrich Chemical Co., Milwaukee, WI).
Comparative Example C5. CF3CFHCF3 - 1,1,1,2,3,3,3-heptafluoropropane
[0062] This compound is available as FM-200™ fire extinguishing agent from Great Lakes Chemical,
West Lafayette, IN.
Comparative Example C6. CF3CF2CF3 - perfluoro-n-propane
[0063] This compound is available as 3M™ CEA-308 fire extinguishing agent from 3M Company,
St. Paul, MN.
Comparative Example C7. CF3(CF2)2CF3 - perfluoro-n-butane
[0064] This compound is available as 3M™ CEA-410 fire extinguishing agent from 3M Company.
Comparative Example C8. CF3(CF2)4CF3 - perfluoro-n-hexane
[0065] This compound is available as 3M™ CEA-614 fire extinguishing agent from 3M Company.
Comparative Example C9. CF3CF(OCH3)CF(CF3)2 - 1,1,1,2,3,4,4,4-octafluoro-3-trifluoromethyl-2-methoxybutane
[0066] To a one liter round bottom flask equipped with an overhead stirrer, a condenser
and an addition funnel was charged 12.8 g (0.22 mol) of anhydrous potassium fluoride,
106 g of anhydrous diglyme, 4 g of methyltrialkyl(C
8-C
10)ammonium chloride (ADOGEN™ 464, available from Aldrich Chemical Company), 53.2 g
(0.20 mol) of CF
3C(O)CF(CF
3)
2 (the perfluorinated ketone was prepared as described in Example 13), and 33.9 g (0.72
mol) of dimethyl sulfate. The resulting mixture was allowed to react at 40 °C for
approximately 24 hours. Then approximately 25 g of a 50% aqueous potassium hydroxide
solution was added to the reaction mixture, followed by 200 mL of water. The resulting
crude product was azeotropically distilled from the reaction mixture. The lower phase
of the resulting distillate was separated from the upper phase, was washed with water,
was dried over anhydrous sodium sulfate, and was distilled (boiling point of 82-83°C;
yield of 45 g). The product identity, 2-methoxy-perfluoro(3-methylbutane), was confirmed
by gcms and FTIR.
Comparative Example C10. C4F9OCH3 - perfluorobutyl methyl ether
[0067] This compound is available from 3M Company, St. Paul, MN as NOVEC™ HFE-7100 engineering
fluid, which is an isomeric mixture of approximately 60% (CF
3)
2CFCF
2OCH
3 and approximately 40% CF
3CF
2CF
2CF
2OCH
3.
Comparative Example C11. CF3CF2CF2OCH3 -1,1,1,2,2,3,3-heptafluoro-3-methoxypropane
[0068] A jacketed one liter round bottom flask was equipped with an overhead stirrer, a
solid carbon dioxide/acetone condenser, and an addition funnel. The flask was charged
with 85 g (1.46 mol) of anhydrous potassium fluoride and 375 g of anhydrous diglyme,
and the flask and its contents were then cooled to about -20°C using a recirculating
refrigeration system. 196 g (1.18 mol) of C
2F
5COF was further added to the flask over a period of about one hour. The flask was
then warmed to about 24°C, and 184.3 g (1.46 mol) of dimethyl sulfate was then added
dropwise via the addition funnel over a 45 minute period. The resulting mixture was
then stirred at room temperature overnight. A total of 318 mL water was then added
dropwise to the mixture. The mixture was transferred to a one liter round bottom flask,
and the resulting product ether was azeotropically distilled. The desired lower product
phase of the resulting distillate was separated from the upper aqueous phase, was
washed once with cold water, and was subsequently distilled to give 180 g of product
(b.p. 36°C; >99.9% purity by glc). The product identity, CF
3(CF
2)
2OCH
3 , was confirmed by gcms and by
1H and
19F NMR.
Comparative Example C12. (CF3)2CFC(O)CH3 - 3,4,4,4-tetralluoro-3-trifluoromethylbutan-2-one
[0069] To a clean dry 600 mL Parr pressure reactor was charged 3.5 g (0.060 mol) of anhydrous
potassium fluoride and 110 g of anhydrous diglyme. The contents in the reactor were
stirred and cooled to less than 0° C, and 25.0 g (0.403 mol) of acetyl fluoride, CH
3C(O)F, was charged from a cylinder. The reactor and its contents were then heated
to 70°C, then 80.1 g (0.534 mol) of hexafluoropropylene was charged over a 6 hour
period at a tank pressure not exceeding 55 psig (3600 torr) and preferentially less
than 45 psig (3240 torr). After the reaction was allowed to proceed overnight at 70°C,
the reactor contents were allowed to cool and were then distilled to obtain 85 g of
material that contained 59% desired product. Upon fractional distillation there was
obtained 24.0 g (28% of theoretical) of 3,4,4,4-tetralluoro-3-trilluoromethylbutan-2-one,
a clear colorless liquid boiling at 56°C and having a purity of 97.8% as determined
by gas chromatography and mass spectroscopy.
Comparative Example C13. CF3CF2CF2CF2C(O)CH3 - perfluorobutyl methyl ketone -
[0070] available from Fluorochem USA (Catalog 00/01, Catalog number 6819), West Columbia,
SC.
TEST METHODS
Micro-Cup Burner Test
[0071] The Micro-Cup Burner Test is a laboratory test which measures the extinguishing ability
of an agent based on the quantity of agent required to extinguish a fire under the
following test conditions. The Micro-Cup Burner Test utilizes a quartz concentric-tube
laminar-diffusion flame burner (micro-cup burner, of similar design to the above-described
cup apparatus) aligned vertically with all flows upward. A fuel, typically propane
unless otherwise specified, flows at 10.0 sccm (standard cubic centimeters per minute)
through a 5-mm I.D. inner quartz tube which is centered in a 15-mm I.D. quartz chimney.
The chimney extends 4.5 cm above the inner tube. Air flows through the annular region
between the inner tube and the chimney at 1000 sccm. Prior to the addition of extinguishing
composition, a visually stable flame is supported on top of the inner tube, and the.
resulting combustion products flow out through the chimney. An extinguishing composition
to be evaluated is introduced into the air stream upstream of the burner. Liquid compositions
are introduced by a syringe pump (which is calibrated to within 1%) and are volatilized
in a heated trap. Gaseous compositions are introduced via a mass-flow controller to
the air stream upstream from the burner. For consistency, the air-gaseous composition
mixture then flows through the heated trap prior to its introduction to the flame
burner. A gas flows are maintained by electronic mass-flow controllers which are calibrated
to within 2%. The fuel is ignited to produce a flame and is allowed to burn for 90
seconds. After 90 seconds, a specific flow rate of composition is introduced, and
the time required for the flame to be extinguished is recorded. The reported extinguishing
concentrations are the recorded volume % of extinguishing composition in air required
to extinguish the flame within an average time of 30 seconds or less.
Mass Ratio Calculation
[0072] The above-mentioned cup burner test measures the performance of an extinguishing
composition by determining the minimum volume percent of composition in air required
to extinguish a test fire. However, it is often desirable to directly compare the
fire performance of an experimental extinguishing composition (e.g., a fluorinated
ketone) against the performance of a state-of-the-art extinguishing composition, such
as HALON™ 1211 fire extinguishing agent (CF
2ClBr, a bromochlorofluorocarbon). One way to make such a comparison is to derive the
mass ratio of experimental composition to HALON™ 1211 fire extinguishing agent from
the volume percentages of each composition required for extinguishing. The mass ratio
can be calculated by dividing the experimental composition's extinguishing volume
percent by the HALON™ 1211 agent's extinguishing volume percent and multiplying the
resulting quotient (which, according to the ideal gas law, also represents the ratio
of mole percents) times the weight average molecular weight of the experimental composition
divided by the molecular weight of HALON™ 1211 agent (165 g/mole).
TESTING
Examples 1-16 and Comparative Examples C1-C13
[0073] In Comparative Example C1, the extinguishing concentration (volume % in air) of HALON™
1211 fire extinguishing agent was determined as using the Micro-Cup Burner Test.
[0074] In Examples 1-16, the extinguishing concentration of several perfluorinated ketones
was also determined using the Micro-Cup Burner Test. The mass ratio as compared to
HALON™ 1211 fire extinguishing agent was then calculated using the Mass Ratio Calculation.
[0075] In Comparative Examples C2-C11, various fluorinated extinguishing compositions known
in the art (hydrofluorocarbons, perfluorocarbons, hydrochlorofluorocarbons, hydrofluoroethers,
and iodofluorocarbons) were evaluated for their extinguishing concentration, and subsequently
their mass ratios were calculated with respect to HALON™ 1211 agent.
[0076] In Comparative Examples C12-C13, two fluorinated ketones, each containing three hydrogen
atoms on the carbon backbone, were evaluated for their extinguishing concentration
and their mass ratio with respect to HALON™ 1211 agent.
[0077] Results from these evaluations are shown in TABLE 1 and are presented in ascending
order of "Mass Ratio to HALON™ 1211," which represents the most meaningful clean extinguishing
agent comparative performance parameter.
TABLE 1
Ex. |
Extinguishing Composition |
Mol. Wt. |
Boiling Point (°C) |
Ext. Conc. (vol %) |
Mass Ratio to HALON TM 1211 |
C1 |
CF2ClBr
(HALONTM 1211) |
165 |
-3 |
3.6 |
1.00 |
1 |
CF3CF2C(O)CF(CF3)2 |
316 |
47 |
3.5 |
1.86 |
2 |
(CF3)2CFC(O)CF(CF3)2 |
366 |
71-72 |
3.3 |
2.03 |
3 |
65/35 (wt) ratio of
(CF3)2CFC(O)CF(CF3)2(Ex. 2) and
CF3CF2CF2C(O)CF(CF3)2 (Ex. 7) |
366 |
71-75 |
3.4 |
2.09 |
4 |
CF3(CF2)5C(0)CF3 |
416 |
97 |
3.1 |
2.17 |
5 |
CF3C(O)CF(CF3)2 |
266 |
24 |
4.9 |
2.19 |
6 |
HCF2CF2C(O)CF(CF3)2 |
298 |
70-71 |
4.4 |
2.20 |
7 |
CF3(CF2)2C(O)CF(CF3)2 |
366 |
73-75 |
3.6 |
2.21 |
8 |
(CF3)2CFC(O)CF2CI |
282.5 |
56 |
4.7 |
2.23 |
9 |
CF3CF2C(O)CF2CF2CF3 |
316 |
52 |
4.5 |
2.39 |
10 |
CF3C(O)CH2C(O)CF3 |
208 |
70-71 |
7.3 |
2.55 |
11 |
(CF3)2CFC(O)C(O)CF(CF3)2 |
382 |
98 |
4.0 |
2.57 |
12 |
CF3CF2CF2C(O)CF2CF2CF3 |
366 |
75 |
4.3 |
2.64 |
13 |
CF3C(O)CF2CF3 |
216 |
0 |
7.4 |
2.68 |
14 |
CF3OCF2CF2C(O)CF(CF3)2 |
382 |
77 |
4.3 |
2.76 |
15 |
perfluorocyclohexanone |
278 |
53 |
6.0 |
2.80 |
16 |
CF3(CF2)3C(O)CF(CF3)2 |
416 |
97 |
4.3 |
3.00 |
C2 |
CF3I |
196 |
-23 |
3.5 |
1.14 |
C3 |
CF3CH2CF3 |
152 |
-1 |
6.3 |
1.61 |
C4 |
CF3CHCl2 (80%)
+ CF4 (20%) |
165 |
-4 |
6.7 |
1.87 |
C5 |
CF3CHFCF3 |
170 |
-16 |
6.6 |
1.90 |
C6 |
CF3CF2CF3 |
188 |
-37 |
6.5 |
2.05 |
C7 |
CF3(CF2)2CF3 |
238 |
-2 |
5.3 |
2.12 |
C8 |
CF3(CF2)4CF3 |
338 |
56 |
4.0 |
2.27 |
C9 |
CF3CF(OCH3)CF(CF3)2 |
300 |
72-73 |
4.5 |
2.27 |
C10 |
C4F9OCH3 |
250 |
61 |
6.1 |
2.52 |
C11 |
CF3(CF2)20CH3 |
200 |
34 |
7.5 |
2.52 |
C12 |
(CF3)2CFC(O)CH3 |
212 |
53-55 |
6.8 |
2.42 |
C13 |
CF3(CF2)3C(O)CH3 |
262 |
87 |
6.3 |
2.77 |
[0078] The data in TABLE 1 show that the extinguishing concentrations and mass ratios of
perfluorinated ketones (see Examples 1-16) generally exhibit good performance as extinguishing
compositions when compared to clean agent extinguishing compositions being evaluated
as HALON
TM fire extinguishing agent replacements (see Comparative Examples C2-C11).
[0079] The data also demonstrate generally superior fire extinguishing performance of the
perfluoroketones when compared to partially fluorinated ketones with approximately
the same carbon number. For example CF
3(CF
2)
5C(O)CF
3 (Ex. 4) and CF
3C(O)CF(CF
3)
2 (Ex. 5), where the ketone has a trifluoromethyl group on one side of the carbonyl
group and has a perfluorinated alkyl group of 3 or 6 carbons on the other side, both
show a lower "Mass Ratio to HALON™ 1211" value (2.17 and 2.19, respectively) than
do either (CF
3)
2CFC(O)CH
3 (Comp. Ex. C12) or CF
3(CF
2)
3C(O)CH
3 (Comp. Ex. C13), which showed "Mass Ratio to HALON™ 1211" values of 2.42 and 2.77,
respectively, where the ketone has an unfluorinated methyl on one side of the carbonyl
group and a perfluorinated alkyl group (straight or branched) of 4 carbons on the
other side. Also, the perfluorinated CF
3CF
2C(O)CF(CF
3)
2 (Ex. 1) shows a lower "Mass Ratio to HALON™ 1211" value than does the monohydrido
analogue, HCF
2CF
2C(O)CF(CF
3)
2 (Ex. 6) (1.86 compared to 2.20), though the monohydrido ketone outperformed the trihydrido
ketones (Comp. Ex. C12 and C13).
Examples 17-18.
[0080] These two examples were run to illustrate the fire performance of a fluorinated ketone,
CF
3CF
2C(O)CF(CF
3)
2 (the fluorinated ketone as prepared in Example 1), using a manual suppression full-scale
streaming test for a clean extinguishing agent.
[0081] For each example, a standard off-the-shelf Amerex 131b HALON
TM 1211 handheld extinguisher was used to introduce the extinguishing composition to
the fire. The extinguisher was equipped with a standard 1/2 in (1.3 cm) nominal diameter
rubber hose with a clean extinguishing agent nozzle attached to the end. In each case,
the composition was super-pressurized using dry nitrogen at 130-150 psi (900-1040
kPa). The only modification to the standard extinguisher apparatus was that the nozzle
orifice used had a slightly larger diameter (0.277 in, 0.70 cm) than did the standard
nozzle orifice (0.234 in, 0.60 cm).
[0082] Both fire extinguishing tests were run following essentially the same test procedures
and conditions as outlined in UL Standard 711 for the 2B and 5B pan fire scenarios,
as normally conducted for UL approval at Underwriters Laboratories, Inc., Northbrook,
IL. The only deviation from that test procedure was that the fire tests for these
examples were conducted outside. The fire test pans for the respective fires were
sized to be 2.5 times larger than the ultimate extinguisher rating. For example, a
2B UL-rated extinguisher rating requires a skilled firefighter to be able to extinguish
a 5 ft
2 (0.46 m
2) fire, a 5B UL-rated extinguisher rating requires extinguishing a 12.5 ft
2(1.16 m
2) fire, etc. For both examples, the UL specified pans were 12 in (30 cm) deep, into
which was introduced 4.0 in (10 cm) of water, onto which was introduced 2 in (5 cm)
of commercial grade heptane for fuel, leaving a 6 in (15 cm) freeboard above the fuel
surface. Each fire was allowed to pre-burn 60 seconds before extinguishing commenced,
using an agent flow rate of 0.75-0.80 kg/sec. The discharge time for the extinguishing
of the fire was recorded as was the amount of agent discharged.
[0083] Results from these evaluations are presented in TABLE 2.
TABLE 2
Ex. |
UL Fire Pan Used |
Pre-Burn Time (sec) |
Extinguished (Y/N)? |
Discharge Time (sec) |
Agent Discharged (kg) |
Flow Rate (kg/sec) |
17 |
UL 2B |
60 |
Y |
3.5 |
2.59 |
0.74 |
18 |
UL5B |
60 |
Y |
3.8 |
2.87 |
0.76 |
[0084] The data in TABLE 2 show that the fluorinated ketone performed well as a streaming
agent for fire extinguishing.
Example 19.
[0085] This example was run to evaluate the fire performance of a fluorinated ketone, CF
3CF
2C(O)CF(CF
3)
2 (the fluorinated ketone as prepared in Example 1), in a total flooding evaluation
for a clean extinguishing agent.
[0086] For this evaluation, a 1.28 m
3 (0.915 m x 0.915 m x 1.525 m) steel reinforced polycarbonate "box" enclosure was
used, into which a fixed piping system, normally designed to deliver a gaseous clean
extinguishing agent, was filled instead with a composition that is liquid at room
temperature and discharged into the "box" to extinguish a fire. Using this modified
system and procedure, the liquid fluorinated ketone used, CF
3CF
2C(O)CF(CF
3)
2, could be discharged into the enclosure indirectly in the same manner as could a
gaseous clean extinguishing agent and thus allow the liquid agent to extinguish an
obstructed fire located remotely in the enclosure.
[0087] In this modified procedure, a Swagelok Whitey 2000 mL cylinder was filled with 1000
g of CF
3CF
2C(O)CF(CF
3)
2 and was super-pressurized with nitrogen to 50 psi (345 kPa). Attached to the bottom
of the cylinder was a 0.25 in (0.6 cm) Swagelok Whitey SS1RFA-A stainless steel angle
valve, to which was fixed 34 in (86.4 cm) of nominal 0.25 in (6.5 mm) piping arrangement,
including a 0.25 in (6.5 mm) Jamesbury Clincher 1/4-turn ball valve. The piping was
connected to a Bete NF 0500 square edge orifice nozzle. The Bete nozzle was installed
to discharge horizontally from a side wall of the box equidistant from two adjacent
walls of the enclosure, at a point 35 cm down from the ceiling of the enclosure.
[0088] The fire testing procedure followed was essentially the same as that described in
the Ohmic Heating Test performed by Hughes Associates, Inc., Baltimore, MD (see section
A-3-6 of the 2000 Edition of the National Fire Protection Association NFPA 2001, Standard
for Clean Agent Fire Extinguishing Systems). The discharge time was approximately
50 seconds and extinguishing of the obstructed fire using CF
3CF
2C(O)CF(CF
3)
2 was achieved within 35 seconds from the beginning of agent discharge, indicating
good performance as a flooding clean extinguishing agent.
[0089] Various modifications and alterations of this invention will become apparent to those
skilled in the art without departing from the scope of this invention. The above Examples
1 to 19 are not within the following claims.