Deicing composition contianing one or more fluorinated surfactants

A deicing composition for use in removing ice from a surface such as the windshield of an automobile, which consists essentially of one or more monohydric alcohols, one or more polyhydric alcohols, and one or more anionic fluorinated surfactants in combination.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to fluids for melting and/or preventing the 
formation or re-formation of ice on a surface, and more particularly, to 
deicing compositions for removing ice from the windshield of an 
automobile. 
2. Brief Description of the Prior Art 
The difficulties occasioned by the formation of ice on a surface are well 
known. The term "ice" as used herein refers generically to the various 
forms of frozen water which may be encountered on surfaces such as 
sidewalks, aircraft, automobile windshields, car doors and locks, roads 
and the like. 
In the specific context of a deicing composition for use on automobile 
windshields, for example, the characteristics that are desired in the 
deicing composition are also well known. Among the more important of these 
characteristics are the ability to melt ice quickly, to inhibit its 
re-formation after a period of time, and to have a sufficiently low 
viscosity to "wet" the windshield fully without smearing or streaking, and 
the compatibility of the composition with the materials comprising the 
automobile's windshield and its immediate surroundings. 
A number of deicing formulations have been developed over the years, and 
the art reflects a continuing effort to find a formulation which fully 
possesses each of the recited characteristics. Several deicing 
compositions have been developed containing monohydric alcohols to 
initially melt the ice on a windshield, polyhydric alcohols to inhibit the 
reformation of ice, and surfactants. 
For example, one commercially available deicing product utilizes a 
composition including monohydric and polyhydric alcohols, a dye, about 1.5 
percent by weight of water, and an alkyloxyalkyl sodium sulfate 
surfactant. 
U.S. Pat. No. 3,245,912 to White discloses a deicing composition including 
monohydric alcohols, polyhydric alcohols, and from 0.25 to about 3 percent 
by weight of an alkylphenoxypolyethanoxyethanol surfactant. The monohydric 
alcohols fraction is preferably mostly isopropanol, and the reference 
discusses the previous commercial use of combinations of monohydric and 
polyhydric alcohols in deicing. 
U.S. Pat. No. 4,235,637 to Singleton discloses an anti-foggant composition, 
as opposed to a deicing composition, which incorporates a lower alcohol, a 
lower polyhydric alcohol, and a surfactant or a mixture of anionic or 
nonionic surfactants such as contained in an IVORY liquid dishwashing 
detergent, for example, with starch granules for spraying onto mirrors and 
the like. The lower alcohol can be isopropyl alcohol, propyl alcohol, 
ethyl alcohol, or methyl alcohol, for example. 
Japanese Application 63-077,987 discloses a foam composition for use in 
preventing the freezing over of windshields, for example. The composition 
contains lower alcohols such as methanol and isopropanol, hygroscopic 
polyhydric alcohols such as ethylene glycol and glycerol, and 
polyoxyethylene stearyl and cetyl ethers as surfactants for forming and 
maintaining the foam. 
A liquid deicing formulation containing 30 percent of ethylene glycol, 70 
percent of isopropanol, and 1-10 percent of nonionic surfactants based on 
the combined ethylene glycol and isopropanol is reported by Ushakova, Tr. 
Nauch.-Issled. Tekhnokhim. Inst. Byt. Obsluzhivaniya, No.6, 34-39(1965). 
Japanese Application 71-16487 discloses a frost-preventing agent for car 
windshields and windows which comprises as a major component one or more 
glycols, an alcohol diluent, 2-ethoxyethanol and a surfactant for use as a 
wetting agent. 
West German patent DE 3,208,219 A1 to Wack et al. discloses an anti-icing 
liquid for the windshield of an automobile which contains an "active 
substance" such as a citrate, phosphate, nitrilotriacetic acid or 
ethylenediaminetetraacetic acid in a concentration between 3 percent and 
the saturation concentration of the active substance in water, 0.01 to 5 
percent of a (fluoro)surfactant for improved wetting of the windshield, 
2-12 percent alcohol for improved wetting also, 5-30 percent of glycol(s), 
and 1-8 percent of a "solvent aid", with the remainder being water. 
Examples of suitable "solvent aids" include "toluene sulfonate, xylene 
sulfonate, cumene sulfonate or a derivative of an alkyl-substituted 
dicarboxylic acid such as an alkyl radical from C.sub.1 to C.sub.12 
reacted with maleic anhydride." 
The seemingly complete body of art relating to deicing compositions does 
not, however, appear to disclose or suggest the comparatively simple yet 
efficacious composition described below. 
SUMMARY OF THE INVENTION 
It has been discovered that a simple composition consisting essentially of 
one or more monohydric alcohols, one or more polyhydric alcohols, and one 
or more fluorinated surfactants possesses the characteristics desired of a 
deicing fluid for automobile windshields and windows particularly. 
More specifically, it has been discovered that a composition consisting 
essentially of from about 70 percent by weight of the one or more 
monohydric alcohols, from about 5 percent by weight of the one or more 
polyhydric alcohols, and from about 0.001 percent up to about 5 percent by 
weight of the one or more fluorinated surfactants melts ice from a 
windshield, inhibits its effective re-formation, and is compatible with 
older and newer car finishes as well as vinyl tops, windshield seals and 
wiper blades.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
The monohydric alcohol or alcohols which comprise a portion of the 
composition of the present invention are water-soluble and are primarily 
included to melt existing ice from a surface such as an automobile 
windshield quickly. Preferred monohydric alcohols possess from one to 
three carbon atoms and include methanol, ethanol, n-propanol, and 
isopropanol. The monohydric alcohol portion or fraction preferably 
comprises from about 70 to about 95 percent by weight of the deicing 
composition. Most preferably, the monohydric alcohol portion of the 
composition is at least about 70 percent by weight of isopropanol, and 
comprises from about 70 to about 90 percent by weight of the composition. 
The polyhydric alcohol or alcohols which are used in the present invention 
provide a resistance to re-freezing and to the effective re-formation of 
ice on the windshield or other surface after the ice has been once melted. 
Preferred polyhydric alcohols are the alkylene and dialkylene glycols 
containing from two to four carbon atoms in the alkyl portion or portions, 
respectively, thereof- for example, ethylene glycol, diethylene glycol, 
propylene glycol, and dipropylene glycol. The polyhydric alcohol portion 
preferably comprises from about 5 to about 30 percent by weight of the 
composition. Most preferably, the polyhydric alcohol portion is at least 
about 10 percent by weight of propylene glycol, and comprises from about 
10 to about 30 percent by weight of the composition. 
The one or more fluorinated surfactants which are necessary to the present 
invention are preferably included in amounts which are effective for the 
primary purpose of increasing the speed at which the monohydric alcohol or 
alcohols melt existing ice from a surface, while at the same time being 
compatible with automobile finishes, vinyl coverings, windshield seals, 
windshield wipers and other materials likely to be contacted by the 
windshield deicer composition. 
Fluorinated surfactants which have specifically been found suitable for use 
in the deicing composition of the present invention are presently sold as 
Zonyl* FSJ fluorosurfactant by E. I. DuPont de Nemours & Co., Inc., 
Wilmington, Del. The Zonyl* FSJ fluorosurfactant material is said by the 
manufacturer to comprise about 15 percent by weight of isopropanol, about 
40 to 45 percent by weight of water, and about 40 percent by weight of a 
mixture of fluorinated surfactants and non-fluorinated surfactants, of 
which mixture the non-fluorinated surfactants comprise about 15 percent by 
weight. The fluorinated surfactants are a mixture of mono- and bis- 
fluoroalkyl phosphates, ammonium salt, complexed with an aliphatic 
quaternary methosulfate. 
Other fluorinated surfactants which may be suitably used include the 
fluorosurfactant materials presently commercially available under the 
Zonyl* FSK, Zonyl* FSN, Zonyl* FSO, and Zonyl* FSP product designations 
from E. I. DuPont de Nemours & Co., Inc., Wilmington, Del. The Zonyl* FSK 
material is described by its manufacturer as comprising about 53% by 
weight of acetic acid and about 47% by weight of a perfluoroalkyl N-type 
betaine. The Zonyl* FSN fluorosurfactant material is described as 
comprising about 40% of a perfluoroalkyl ethoxylate, about 30% by weight 
of isopropanol, and about 30% by weight of water. The Zonyl* FSO material 
is said to comprise about 50% by weight of a perfluoroalkyl ethoxylate 
mixture, about 25% by weight of ethylene glycol, and about 25% by weight 
of water, while the Zonyl* FSP material is described as comprising about 
35% by weight of a mixture of mono- and bis- perfluoroalkylphosphates, 
about 20% by weight of isopropanol, and about 45% by weight of water. 
The fluorinated surfactants contributed by these Zonyl* fluorosurfactant 
materials preferably comprise from about 0.001 to about 1.0 percent by 
weight of the deicing composition, although it is anticipated that 
generally up to about 5 percent by weight could be used of the 
fluorosurfactants without detrimental effect on the performance of the 
windshield deicer provided by the present invention, with the amount of 
isopropanol or other monohydric alcohol(s) being reduced proportionately. 
Most preferably, the fluorinated surfactants are employed in the form of 
an amount of the Zonyl* FSJ fluorosurfactant material that is from about 
0.01 to about 0.5 percent by weight of the deicer, which would correspond 
according to the manufacturer's specifications to a fluorinated surfactant 
content of from about 0.003 to about 0.17 percent by weight of the deicer. 
While additional Zonyl* FSJ fluorosurfactant material may be added above 
the range of amounts thus specified for the most preferred embodiment, no 
particular advantage has been seen from doing so, and embodiments 
employing amounts in the neighborhood of about 0.05 percent by weight of 
the Zonyl* FSJ material have been found to be fully effective. 
While the Zonyl* FSJ material contributes some water and some 
non-fluorinated surfactants to the deicer composition in its preferred 
form, the amounts of water and non-fluorinated surfactants contributed 
thereby each comprise less than about 0.5 percent by weight of the overall 
composition. It should be noted that while additional water and other 
materials could conceivably be added to the deicer of the present 
invention without substantially diminishing its effectiveness, it will be 
seen that the present deicer is possessed in the simple formulations set 
forth above of the desired characteristics for such a deicer without 
incurring the expense associated with adding such additional materials. In 
particular, the deicer constituted as described herein melts ice from a 
windshield, inhibits its effective re-formation, and is compatible with 
older and newer car finishes as well as vinyl tops, windshield seals, and 
wiper blades. 
The deicer may optionally contain from about 0.0001 to about 0.1 percent by 
weight of a dye for purposes of identification, and preferably this dye is 
a nonionic polymeric, non-azo dye which will not stain clothing, skin, or 
the interior of an automobile on which the deicer is used. Most preferably 
the dye is a polymer bound triphenyl methane colourant, an example of 
which is presently sold under the designation Liquitint Patent Blue* by 
Milliken Chemical. 
The deicer of the present invention is further illustrated by the following 
Examples. 
EXAMPLE 1 
Two deicer formulations were prepared and tested for compatibility with 
windshield wipers, vinyl exterior coverings, butyl rubber for sealing 
windshields, and various painted surfaces and finishes prepared on test 
panels and on autos from a scrap yard. Formulation A was comprised of 
79.98 wt. percent isopropanol, 20.00 wt. percent propylene glycol, 0.02 
wt. percent Zonyl* FSJ fluorosurfactant, and 0.004 wt. percent of the 
Liqui-Tint Patent Blue* dye Formulation B was comprised of 79.98 wt. 
percent isopropanol, 15.00 wt. percent propylene glycol, 5.00 wt percent 
ethylene glycol, 0.02 wt. percent Zonyl* FSJ fluorosurfactant, an percent 
Liqui-Tint Patent Blue* dye. 
a. Windshield Wiper Compatibility 
Windshield wiper samples were weighed and measured, then immersed in the 
deicer formulations for a period of 48 hours. After immersion, the samples 
were removed and remeasured and reweighed. The weight of the samples after 
immersion in formulations A and B increased less than 0.01 percent. 
b. Vinyl Covering Compatibility 
A sample of brown vinyl used for exterior car roofs was tested per ASTM 
1882 for both formulations, and the formulations were also tested on the 
vinyl tops of automobiles from a scrap yard, one automobile from the 1978 
model year having beige vinyl and one automobile from the 1981 model year 
with red vinyl. Neither formulation was seen to have an effect on the 
vinyl samples tested. 
c. Butyl Rubber Compatibility 
Samples of butyl rubber were weighed and the dimensions measured, then 
immersed in the two formulations for three weeks at room temperature 
(about 20.degree. C.). The samples were then removed, reweighed and 
remeasured. The formulations both were clear upon removal of the samples, 
and no dimensional or weight changes were noted for samples soaked in 
either formulation. 
d. Painted Surfaces Compatibility 
Samples of formulations A and B were tested according to ASTM 1882 on test 
panels prepared using a PPG Industries high solids white enamel base 
coat/clear coat finish, an Inmont Canada,Inc. high solids white enamel 
base coat/clear coat finish, and a PPG Industries high solids white enamel 
basecoat finish. Formulations A and B were also tested on a number of 
randomly selected autos from a local scrapyard. No change was noted in the 
test panels. Results from the scrapyard testing are reported in Table 1. 
"Soft Wax Finish" as used in Table 1 will be understood to mean that the 
wax finish of the automobile was softened. 
TABLE 1 
______________________________________ 
A B 
______________________________________ 
1975 Pontiac Phoenix 
No effect No effect 
(Grey Metallic) 
1978 Chev. Impala 
No effect No effect 
(Brown Metallic) 
1978 Ford Cougar 
Soft Wax Finish 
Soft Wax Finish 
(Beige Metallic) 
1982 Ford Marquis 
Soft Wax Finish 
Soft Wax Finish 
(Yellow) 
1983 Chev. Malibu Classic 
No effect No effect 
(Green Metallic) No effect 
1981 Chev. Camaro 
No effect 
(Blue Metallic) 
1987 Chrysler Rampage 
No effect No effect 
(Grey Clear Coat) 
______________________________________ 
EXAMPLE 2 
The deicing ability and ability to inhibit the effective reformation of ice 
on a surface were tested for deicer formulations containing propylene 
glycol, isopropanol, the Liqui-Tint Patent Blue* dye, and various amounts 
of the Zonyl* FSJ material. In each of the deicer formulations, the dye 
comprised 0.004 wt. percent of the composition and the propylene glycol 
20.00 wt. percent, with 0 wt. percent (formulation C),0.01 wt. percent 
(formulation D), 0.05 wt. percent(E), and 1.0 wt. percent (F) of the 
Zonyl* FSJ material, and the remainder comprising isopropanol. 
a. Deicing Ability 
In this and subsequent tests performed for this Example, a testing chamber 
capable of maintaining temperatures between -20.degree. C. and 60.degree. 
C. and a relative humidity between 50 and 100% was used. A heat exchanger 
unit was located inside of the test chamber with four 20 cm..times.30 cm. 
polished aluminum panels carried thereby. Each panel was held at a slope 
of 10.+-..02 degrees. The test panels were maintained at -5.+-.0.5.degree. 
C. 
The test chamber also was capable of simulating freezing rain conditions by 
supplying water at a constant pressure through nozzles producing a mist of 
specified droplet size, distribution and intensity. For purposes of this 
Example, the rain was applied at a rate of 5.+-.0.2 g/dm.sup.2/ hour, with 
an average droplet size of 20 microns and with 50 percent of the droplets 
being between 15 and 35 microns in diameter. 
For the test of the deicing ability of the various formulations, the 
relative humidity of the test chamber was set at 80%, and freezing rain 
was applied for 15 minutes. After the rain had been applied, the panels 
were allowed to equilibrate for 5 minutes, and using a hand-held spray 
bottle 2.5 grams of a respective deicer formulation was applied to each 
panel. After one minute, a window "squeegee" was dragged across the 
surface of each panel twice with constant pressure. 
Not all of the ice was removed from panels treated with formulation C, a 
smaller amount of ice was observed to remain for panels treated with 
formulation D, and all of the ice appeared to have been melted on panels 
treated with formulations E and F. 
b. Time to Re-formation of Ice 
For this test, the room temperature was maintained at from 0.degree. to 
1.degree. C., and the relative humidity controlled at 95 percent. After 
freezing rain was applied for 15 minutes, the test panels were again 
allowed to equilibrate for 5 minutes, whereupon generous quantities of a 
formulation were sprayed onto each panel. After one minute, the squeegee 
was dragged across each panel three times. The time to re-formation of ice 
was noted for the panels treated with the various formulations. 
Each formulation containing the Zonyl* FSJ material appeared to perform 
identically well with this test. After one minute, some light condensation 
was noted. After three minutes at rest, ice was observed for each such 
formulation to cover about 5 percent of the surface. After four minutes 15 
percent of the ice had reformed, and after 5 minutes, 50 percent had 
reformed. Finally, after 6 minutes, 70 percent of the surface of the 
panels was again covered. In contrast, formulation C (with none of the 
Zonyl* FSJ material) showed light condensation after one minute at rest, 
heavy condensation with ice over 5 percent of the surface after 2 minutes, 
ice over 25 percent of the surface after 3 minutes, over 50 percent of the 
surface after 4 minutes, over 70 percent of the surface after 5 minutes, 
and over 80 percent of the surface after 6 minutes. 
c. Apparent Strength of Re-formed Ice 
The same procedure was followed as in test (b) above, except that after 5 
minutes of allowing the ice to reform, the squeegee was dragged across the 
surface of each panel twice and the surface of each panel examined for 
residual ice. 
Panels treated with formulation C exhibited ice over 30 percent of the 
surface which strongly adhered to the surface, while panels treated with 
the remaining formulations were left with 20 percent of their surfaces 
covered with ice. 
It can be seen from the foregoing examples that the deicing composition of 
the present invention is possessed of the characteristics which are 
desired of such materials, and is well suited for use with automobile 
windshields and the like in particular. Further, while preferred 
embodiments of the present invention have been set forth herein, it will 
nevertheless be appreciated that numerous modifications can be made 
thereto which do not depart from the spirit and scope of the present 
invention as defined by the appended claims.