Note: Descriptions are shown in the official language in which they were submitted.
--1--
ANTI MISTING ADDITIVE
FOR ~I~lDROCARBON FLUIDS
The invention relates to a process for pre~
venting the dissemination of a hydrocarbon liquid
having a free surface into a dispersion of fine liquid
droplets under conditions of shock or stress. It is
often desirable to control the extent of misting or
dispersion-in-air of hydrocarbon liquids having rather
low flash points. More particularly, hydrocarbon fuels
such as are employed in aircraft are desirably protected
from misting under conditions of shock or stress as
produced, for example, during an aircraft crash, or
whenever such ~uels are subjected to shock or stress
while exposed to an ignition source. Additionally it
is also desirable to control mist formation in
hydrocarbon-based metal cutting fluids employed in
metal cutting, grinding and machining operations.
In U.S. Patent 3,996,023, several polymers
suitably employed in preventing the misting of
hydrocarbon fuels aré disclosed. Preferred compounds
include non-crystalline polymers substantially devoid
of polar groups, especially polymers of ethylenically
unsaturated hydrocarbons such as ethylene, propylene,
24,801B-F
IL80~
isobutylene, and butadiene. Polymers formed by the
addition polymerization of alkylene oxides are briefly
discussed. In U.S. Patent 3,557,017, ultra high
molecular weight oxyalkylene polymers are taught as
demulsifiers and thickeners for hydrocarbon systems
used in oil well fracturing. Preferred oxyalkylene
oxide polymers were those derived from propylene oxide.
Numerous catalyst systems are known for prep-
aration of high molecular weight alkylene oxides.
Illustrative are a combination of ferric halide salts
and propylene oxide disclosed in U.S. Patent 2,706,181,
or organoaluminum, organozinc and organomagnesium
compounds taught in U.S. Patent 2,870,100. Improved
coordination anionic polymerization systems include
chelated forms of organoaluminum such as disclosed in
U.S.Patents 3,219,591; 3,186,958; 3,301,796; and
3,135,705.
In recent investigations the important contri-
bution of elongation deformation to polymeric rheo-
logical behavior has been identified. It has now beenrecognized that various properties of significant
commercial application cannot be adequately predicted
by viscometric (shear) flow behavior alone. Often, due
to inherent differences in elongation or tensile
deformation versus shear deformation, the corresponding
elongational viscosity and shear viscosity may be
related in only the extremely limited case where the
material is Newtonian in both elongation and shear.
Because of this recognized difference between elonga-
tional and shear flow, the researcher is not necessarilyable to predict the response to elongational flow of a
viscoelastic material based on knowledge of its shear
24,801B-F -2-
--3--
flow behavior. Such elongational deformation
properties are in fact particularly relevant in
imparting improved performance to anti-misting agents.
Because the tensile or elongational viscosity of
various materials appears to be affected by molecular
weight considerations, particularly the average molecular
weight and the distribution thereof, as well as by
molecular geometry, the elongation properties of polymeric
compounds and therefore the anti-misting properties
thereof are not necessarily predictable on the basis of
shear viscosity considerations.
Another important property of an anti-misting
agent is the shear stability of the material. Application
of relatively mild shear should not significantly
degrade the polymer and thereby destroy the polymer's
ability to prevent the dispersion of the hydrocarbon
liquid. For example, normal pumping and handling
procedures used in transporting a jet fuel should not
cause deterioration of the anti-misting properties of
the polymer. Shear stability is particularly desired
in cutting fluids due to repeated use under conditions
of relatively high shear.
It would be desirable to provide a polymer
that is effective in preventing the formation of hydro-
carbon-air dispersions or mists at low levels of con-
centration, that is highly soluble in the hydrocarbon
liguid, such that even at extremely low temperatures
essentially no precipitate or colloidal state forms,
and that is relatively stable and not degraded by shear
forces.
24,801B-F -3-
--4--
Accordingly, there is now provided an improved
process for preventing the dispersion o~ a hydrocarbon
liquid having a free surface upon application of shock
or stress comprising adding to the hydrocarbon liquid
an effective amount to prevent the dispersion thereof
of a high molecular weight addition polymer comprising
polymerized 1,2-epoxybutane. Also provided is a compo-
sition comprising a hydrocarbon liquid and an effective
amount to prevent the formation of a dispersion thereof
upon application of shock or stress thereto of a high
molecular weight addition polymer comprising polymer-
ized 1,2-epoxybutane.
Addition polymers comprising polybutylene
oxide, e.g., addition polymers of 1,2-epoxybutane, use-
ful herein may be prepared by any technique suited tothe preparation of extremely high molecular weight
polymers. Examples include the anionic polymerization
of U.S. Patents, 2,870,100 and 3,219,591.
A preferred catalyst for polymerizing 1,2-
epoxybutane to extremely high molecular weight polybutyl-
ene oxide comprises a composition prepared by contacting:
Component A/ a compound represented by the
formula RR'AlX wherein R and R' each independently
represent an alkyl group of 1 to 4 carbon atoms,
and X represents hydrogen or an alkyl or alkoxy
group of 1 to 4 carbon atoms;
Component B, an organic nitrogen base com-
pound selected from secondary nitrogen-containing
compounds having basicity about e~ual to cr less
than the basicity of dimethylamine and having no
active hydrogen atoms other than those of the
secondary nitrogen;
24,801B-F -4-
Component C, a ~-diketone; and
Component D, water;
in the molar ratios o~
B:A - 0.01:1 to 2.5:1
C:A - 0.1:1 to 1.5:1
D:A - 0.01:1 to 1.5:1
provided that when the molar ratio o~ (C + 2D):A is
greater than 3:1, the B:A molar ratio is at least 1:1.
The preferred catalyst is more particularly
defined as follows. Component A is a compound repre-
sented by the formula RR'AlX wherein R and R' each
independently represent an alkyl group of 1 to 4 carbon
atoms, and X represents hydrogen or an alkyl or alkoxy
group of 1 to 4 carbon atoms. In a preferred mode, X
represents an alkyl group.~ In a more preferred mode,
R, R' and X all represent the same alkyl group and most
preferably, the compound is triethylaluminum. Examples
o~ suitable compounds are trimethylaluminum, triethylalu-
minum, triisobutylaluminum, tri-n-propylaluminum,
tri-n-butylaluminum, diethylaluminum hydride, dipropyl-
aluminum hydride, diisobutylaluminum hydride, diethyl
ethoxy aluminum, and diisobutyl ethoxy aluminum. In
practice, Component A is normally supplied in a solution
of a hydrocarbon OL other solvent.
Component B is an organic nitrogen base com-
pound selected from secondary nitrogen-containing com-
pounds having basicity about equal to or less than the
basicit,v of dimethylamine and having no active hydrogen
atoms other than those of the secondary nitrogen. By
24,801B-F -5-
~13L8~l86
--6--
"active hydrogen atoms" are mear.t Zerewitinoff hydrogen
atoms (see J. Am. Chem. Soc., 49:3181 (19Z8)) which
initiate alkylene oxide polymerization as are found on
hydroxyl, thio or primary and secondary amine functional
groups. Such secondary amines are commonly those bear-
ing electron-withdrawing groups in close proximity to
the nitrogen atom such as carbonyl groups, phenyl
rings, cyano groups, halo groups, carboxylic acids or
ester groups, and other such groups that have strong
electron-withdrawing effects on -the secondary amine.
For example, such compounds are N-alkyl or -aryl amides,
arylalkylamines, diarylamines, and other weak bases.
Secondary amines having a PKb Of greater than 4 are
suitable and those having PKb of greater than 6 are
preferred. Examples of suitable secondary amines are
dimethylamine, diethylamine, N-methylaniline, N-methyl-
-p-nitroaniline, N alkylacetamide, N-arylacetamide,
succinimide, diphenylamine, phenothiazines, and phen-
oxazines. Especially preferred are phenoxazine,
phenothiazine and N-acetamide.
The strengths of organic bases are compiled
for a large number of such bases in the IUPAC work by
D. D. Perrin, "Dissociation Constants of Organic Bases
in Aqueous Solutions", Butterworths (London, 1965).
For most secondary organic amines not listed therein,
relative base strength may be deduced by examining the
value noted for a structurally related amine then
estimating the effect of structural differences on the
base strength. For example, conjugation of the amino
group with electron-withdrawing groups lowers the base
strength of the amino group. The effects of structural
changes in organic amines are discussed in great detail
in numerous works, for example in "The Chemistry of the
24,801B-F -6-
~8~
Amino Group", S. Patai, Ed., Chapter 4, "Basicity and
Complex Formatlon" by J. W. Smith, pp. 161-204, Inter-
science (New York, 1968).
One simple method for determining whether a
secondary amine is less basic than dimethylamine is to
employ both in side-by-side preparation of the catalyst,
use the resulting catalyst in polymerization of a
monomer such as propylene oxide, and then determine the
intrinsic viscosities of the resulting polypropylene
oxide products. If the intrinsic viscosity of the
product derived from the catalyst prepared with
dimethylamine is lower than the one from the o-ther
amine, then the other amine may be considered less
basic than dimethylamine.
The amount of Component B to be employed may
be expressed in the molar ratio of Component B per mole
of Component A. The lower amount is suitably about
0.01, pref-erably 0.05 and most preferably 0.1. The
upper amount is suitably 2.5, preferably 1 and most
preferably 0.5. The optimum molar ratio of B:A for
producing very high molecular weight polyethers is
about 0.25:1.
Component C is selected from ~-diketones or
the tautomeric enol form thereof. Suitable, for example,
are 2,4-pentanedione, 2,4-hexanedione, 3,5-heptanedione,
l-phenyl-1,3-butanedione, ethylacetylacetate, and
similar materials. Examples of numerous suitable
~-diketones are described in U.S. Patent 2,866,761.
Preferred for use as Component C is 2,4-pentanedione
because of its relative availability.
24,801B-F -7-
--8--
For the amount of Component C to be employed,
expressed as moles of C per mole of A, a lower amount
is suitably 0.1 and preferably 0.2. As an upper amount
the ratio is suitably 1.5 and preferably 0.8. The
optimum molar ratio of C:A is about 0.5:1.
Component D is water and is suitably employed
in a lower amoun'c of about 0.1, preferably 0.3 and more
preferably 0.4, mole of D per mole of A. The upper
amount is suitably 1.5, preferably 1.1 and more
preferably 1.0, mole of D per mole of A. The optimum
ratio of D:A is 0.5 to 0.8:1.
The above components are employed such that
when the molar ratio sum of (C + 2D):A is greater than
3:1, then the B:A molar ratio is at least 1:1.
Preferably the components are combined in the ratio
where (B + C + 2D):A is less than or equal to 3:1 and
more preferably less than 2:1. In one embodiment, the
following molar ratios are employed to form a catalyst
which when contacted with a vicinal alkylene oxide pro-
duces a polyether of a very high intrinsic viscosity:B:A - about 0.~5:1; C:A - about 0.5:1; and D:A - about
0.6:1. In a second embodiment, a catalyst is prepared
which will give moderateIy high intrinsic viscosity
polyethers when contacted with vicinal alkylene oxides
according to the process described herein. The molar
ratios in this second embodiment are: B:A - about
2.5:1; C:A -about 0.5:1; and D:A - about 0.5:1. The
most preferred species of the ca-talyst are prepared in
the form where B is phenothiazine or N-methylacetamide
or C is 2,4-pentanedione.
Additional components may be present in the
catalyst and certain additives have in fact been found
24,801B-F -8-
~,
- 9 -
to provide improved catalytic performance. In particu-
lar, a small but effective amount of a Lewis base such
as a tertiary amine or an aliphatic ether capable of
forming a complex with Component A may be added to the
catalyst mixture. Preferred Lewis base compounds are
the aliphatic ethers, most suitably cyclic aliphatic
ethers such as tetrahydrofuran or dioxane. These
compounds are employed in minor amounts sufficient to
form a complex with Component A in the presence of the
remaining components of the catalys-t. Suitably the
aliphatic ether is present in molar amounts from 1 to 6
for each mole of Component A.
Additional components may also be present in
the catalyst if desixed. For example, ether alcohols
such as 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol,
2-methoxypropanol, 2-ethoxypropanol, and lower alkyl
monoethers of diethylene glycol or dipropylene glycol
may be added to the catalyst in purified form as an aid
in rendering the catalyst soluble in various solvents.
The catalyst formation and polymerization are
carried out according to known techniques such as those
of U.S. Patents 3,186,958 and 3,219,591. Suitably the
catalyst is prepared by contacting the components in
the desired ratios in any of the common hydrocarbon or
chlorinated hydrocarbon diluents employed for organic
reactions so long as they do not bear Zerewitinoff
hydrogen atoms. Suitable diluents, for example, are
hexane, toluene, benzene, styrene, decane, chloroben-
zene, trichloroethane, perchloroethylene and the like.
A preferred diluent is the hydrocarbon fluid, e.g.,
fuel or cutting oil, to which the polymer will be later
added.
24,801B-F -9-
--10--
While the catalyst components may be combined
in any order desired, because it has been found most
effective to employ polymers of relatively high intrinsic
viscosity in the present invention, it is preferable,
S particularly where the catalyst consists essentially of
only Components A, B, C and D, that Components B, C and
D be first combined by mixing them well and thereafter
adding Component A to the mixture of the other three
components. It is also convenient to prepare the
catalyst ln situ in the butylene oxide monomer to be
polymerized. This is most preferably done by combining
Components B, C and D in a solvent witk the desired
quantity of butylene oxide monomer and thereafter
adding Component A to the mixture after which the
polymerization is allowed to proceed. In this fashion,
the butylene oxide monomer acts as a cosolvent for the
catalyst prior to initiation of the polymerization.
Butylene oxide for polymerization and use herein may
first be purified as by the technique described in U.S.
Patent 3,987,065.
After preparation of the high molecular
weight polymer, the catalyst may be "killed'l or
deactivated by addition of a reactive hydroxyl compound
such as water, alcohols or organic acids. Where the
polymer is prepared in the hydrocarbon fluid, such as
jet fuel, the catalyst may be effectively "killed" by
exposure to the atmosphere for a short time. It is
believed that water vapor present in the air is
sufficient to deactivate the catalyst.
The polymer employed in the instant process
comprises polybutylene oxide. Where the hydrocarbon
liquid is a fuel, for example, a jet fuel for gas
24,801B-F -10-
turbines, it is highly desirable that the polymeric
anti-misting additive not detrimentally form a pre-
cipitate or colloidal state, particularly at low
temperatuxes. The temperature at which such formation
occurs, e.g., the theta temperature of the solution, is
desirably less than -50C. Further discussion of theta
temperature as well as a more detailed description of
suitable components of fuels for gas turbines is con-
tained in U.S. Patent 3,996,0Z3.
In other applications such as where the
hydrocarbon liquid is a cutting fluid, extremely low
theta temperatures are not as necessary. Accordingly,
a theta temperature of greater than -50C may be sui-table.
At the same time certain hydrocarbon liquids, especially
cutting fluids, may contain substantial amounts of a
non-hydrocarbon component, such as an alkylene glycol,
an alkylene glycol ether or even water. Therefore
under conditions where an extremely low theta temperature
is not requisite or the hydrocarbon liquid additionally
comprises non-hydrocarbon components, the polybutylene
oxide anti-misting agent may include comonomers of
additional alkylene oxides. Compatibility with fluids
consisting essentially of hydrocarbon liquids is impaired
by use of excessive amounts of lower alkylene oxide
comonomers such as propylene oxide and especially
ethylene oxide. Accordingly, only relatively minor
amounts of such lower alkylene oxide comonomers are
suitably employed where compatibility with hydrocarbon
liquids, particularly a jet fuel, is desired. Higher
vicinal alkylene oxides such as 1,2-epoxypentane,
1,2-epoxyhexane, etc., or glycidyl ethers such as
n-butyl glycidyl ether, tertiarybutyl glycidyl ether,
n-octyl glycidyl ether, etc., may be employed as
24,801B-F -11-
. . .
-12-
comonomers without as significant a detrimen-tal effect
on compatibility with the hydrocarbon fluid.
The preferred anti-misting agent for use in
hydrocarbon fuels consists essentially of polymerized
1,2-epoxybutane.
While in most applications the catalyst resl-
due may be left in the polymer solution without disadvan-
tageous results, it is also possible to remove catalyst
residue. For example, the aluminum compound which
exists as a hydroxide or oxide after deactivation is
only sparingly soluble in hydrocarbon liquids, particu-
larly at low temperatures and may be removed by filtration.
This process may be particularly desired where the
polymer solution is employed as a jet fuel.
Conventional approaches to molecular weight
measure of polyethers employed herein are often not
appropriate. This is usually due to plugging effects
because of the propensity of high molecular weight
polyethers to "thicken with shear". It is especially
troublesome with such techniques as gel permeation
chromatography for molecular weight estimation. None-
theless, dissolved concentrations of less than 0.06
weight percent of the polyethers generally do not
undergo the shear thickening phenomenon.
In view of the difficulties in employing gel
permeation chromatography to compare the relative
molecular weights of polyethers produced herein, the
alternate method of comparing intrinsic viscosities was
instead employed. Intrinsic viscosity [~] is related
to molecular weight by the equation:
24,801B-F -12-
1~81D~
-13-
[~] = MK~
wherein K is a constant, M is molecular weight and ~ is
another constant (correlated to the degree of configura-
tional coiling in the architecture of an involved poly-
mer).
The value of [~] is determined by plotting
the measured specific viscosity divided by concentration
of polymer in solution (~Sp/conc.) vs. conc. and
extrapolating to zero concentration. It is dependent
upon the solvent and temperature used during measurements.
Toluene is a good solvent for the purpose. And, 100F
(38C) is an apt temperature at which to measure ~sp'
per the equation:
~sp = t
wherein t is the efflux time of solution and to is the
efflux time of solvent.
Efflux times are readily measurable in an
Ostwald viscometer taking values of solutions at four
different concentrations. Usually 1-2 g of the polymer
solution ( 30 percent solids) is dissolved in toluene
overnight with stirring. It is then volumetrically
diluted to ~100 ml. Aliquots of 2 ml, 5 ml, and 15 ml
from this stock solution are then further diluted to:
10 ml, 10 ml, and 25 ml, respec~tively, with more toluene.
Efflux times are then measured on the stock solution,
each of the three solutions and on toluene. With the
24,801B-F -13-
~8~
-14-
viscometer employed, toluene had a to of 30.6 seconds,
while t for the most concentrated solution being tested
is best kept below 200 seconds by adjusting concentration.
Concentration for each diluted solution is
simply calculable from the concentration of the stock
solution. Three samples of this stock solution are
then ordinarily weighed into aluminum dishes from T~hich
they are devolatilized in a vacuum oven at 100C over-
night (under a normal line vacuum). The aluminum
dishes are then reweighed to determine the weight of
pure polymer remaining. Concentratlon is then calcu-
lated as weight percent. This method of determining
concentration is quite convenient since concentration
normally associated with measuring [~] is reported in
the literature as "grams/deciliter". Therefore, values
for concentration so determined are higher by a factor
corresponding to the density of toluene (0.8502 g/cc at
38C). Values for ~sp/conc. and [~] are correspondingly,
therefore, lower by this factor also. Consistent with
this, the herein given [~] values are corrected for the
density factor, with [~] being herein reported in units
of dl/g.
Of particular value in the present invention
as anti-misting agents in hydrocarbon fuels are poly-
meriæed 1,2-epoxybutanes having relatively high intrinsic
viscosity, e.g., intrinsic viscosities in toluene at
38C of at least and preferably 2 and up to 30. Because
of the greater effectiveness toward preventing misting
of higher molecular weight polybutylene oxide polymers,
such polymers of higher molecular weight may be employed
in reduced concentrations thereby resulting in more
economical operation. Preferred are concentrations by
24,801B-F -14-
-15-
weight from 0.05 percent to 1 percent, and preferably
from 0.1 percent to 0.5 percent by weight.
In other applications, such as the prevention
of cutting oil misting, polybutylene oxide polymers of
reduced molecular weight and therefore intrinsic viscosity
may be more suitably employed in order to avoid the
necessary reduction in polymer effectiveness due to
shear degradation of the polymer under long-life service
conditions. A-t the same time, increased levels of
polymer may be employed in order to offset the loss in
effectiveness due to decreased molecular chain length.
Preferred for use in cutting fluids are amounts of
polymer by weight from 0.1 percent to 5.0 percent, most
preferably from 0.2 percent to 1.0 percent.
In particular regard to hydrocarbon fuels, it
should be noted that while the extremely high molecular
weight butylene oxide polymers herein employed are
highly shear stable, they will in fact degrade under
application of sufficien-tly high shear. Accordingly,
20; it is possible, employing mechanical shearing or other
treatment, to degrade the polymer and thereby render
the fuel atomizable or dispersible prior to injection
into -the gas turbine.
The following examples are provided as further
illustrations of the invention.
Example 1 - Cutting Oil
Twenty-five grams of 1,2-butylene oxide,
Mobilmet 308~ metal cutting and working oil available
commercially from Mobil Oil Corporation (225 g), pheno-
thiazine (1.17 g) and 2,4-pentanedione (1.18 g) are
24,801B-F -15-
-16-
combined in a glass reactor. A sample is removed for
water analysis and found to contain 86 ppm water.
Additional water (0.19 g) is added by syringe to
produce a total water content of 0.21 g, triethyl-
aluminum (14.8 percent in hexane) (18.0 g) is addedunder a nitrogen blanket. The reactor is sealed and
placed in a tumbling cage inside a warm water ba-th at
about 86C for 44 hours.
After polymerization, cutting oil containing
polymerized 1,2-butylene oxide is tested for mist
formation. A solution of Mobilmet 308~ cutting oil
containing 0.25 percent by weight of the above polyrner
is prepared by rapidly stirring a portion of the above
product in the cutting oil. Viscosity of the solution
as determined by the cone-plate method is 0.055 Pa S
(55 cps). Unmodified oil has a viscosity of 0.051 Pa S
(51 cps).
Mist control is tested by comparing mist for-
mation upon injecting air (0.38 MPa; 40 psig) through a
drop tube immersed in the fluid to be tested. Mist
formation is noted by visual reference and assigned
values of no-mist, low mist or fail. The fluid is then
exposed to high shear in a laboratory blender for one
hour and retested for anti-mist properties. The
cutting oil containing 0.25 weight percent polybutylene
oxide showed no mist formation even after blending for
one hour. Untreated Mobilmet 308~ produced large
amounts of mist under all testing conditions.
ExamPle 2 - Jet Fuel
~n additional quantity of polymerized 1,2-
butylene oxide is prepared in hexane solvent. The
24,801B-F -16-
`:
-17-
catalyst employed is prepared by com~ininy in a dry box
under nitrogen atmosphere at ambient temperature wi-th
stirring, hexane solutions of triisobutylaluminum
(0.015 mole) and phenothiazine (0.004 mole) ~total hex-
ane is about 40 ml~. Tetrahydrofuran (0.090 mole) isadded dropwise with stirring over a period of about 10
minutes at reduced temperature of 0C-10C. Next,
water (enough to provide 0.006 mole total) is added
dropwise over a period of 10 minutes, followed by
acetylacetone (0.006 mole) which is added dropwise over
a period of 5 minutes. The reaction mixture is stirred
for 1 hour and transferred to a Parr bomb reactor and
diluted with hexane (100 g) and toluene (30 g). After
aging by heating and stirring under nitrogen for one
hour at 95~C, catalyst preparation is compléte.
The polymer is formed by adding about one
mole of 1,2-butylene oxide to the Paar bomb in incre-
ments at 75C over a one-hour period. The reaction
mixture is stirred at 75C for 5 hours and then cooled.
Evaporation of solvent leaves the desir~d polymer, a
light amber colored rubbery solid.
Jet fuel (Jet A) containing 0.2 percent by
weight of polymerized 1,2-butylene oxide prepared
employing the catalyst prepared according to the above
process is tested for anti-misting properties by means
of the Flammability Comparison Test Apparatus (FCTA).
The testing device consists of a compressed air source
connected to a sonic orifice and a diffuser cone. Fuel
is supplled through a metal tube terminating in the
airstream at a point selected to produce high shear to
the fuel entering the airstream. The air fuel mist
thereby prepared is passed over a propane torch flame.
24,801B-F -17-
~18-
Mist ignition is determined by fuel type (including the
presence or absence of an antl-misting agent), the fuel
flow rate and the air velocity.
Passing, marginal and fail grades are assigned
according to visual examination of the flame propagation.
No propagation ahead of the torch constitutes a passing
grade. Propagation ahead of the torch but not to the
diffuser cone constitutes a marginal grade. Propagation
ahead of the torch all the way to the diffuser cone
constitutes a failing grade.
Jet A fuel at 27C which is not treated with
an anti-misting agent consistently fails under all con-
ditions of air velocity above 40 m/sec at fuel flow
rates above 10 ml/sec. To the contrary, when modified
by addition of 0.2 weight percent of polymerized
1,2-butylene oxide, no consistent failure is observed
at fuel flow rates less than 15 ml/sec at air velocities
less than 70 m/sec.
The above test demonstrates that polymerized
1,2-butylene oxide is an effective anti-misting agent
which demonstrates surprisingly good effectiveness at
preventing the formation of a hydrocarbon fuel/air
dispersion even at extremely low concentrations.
2'~,801B-F -18-
