Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
  • C09D5/02—Emulsion paints including aerosols
  • C09D5/024—Emulsion paints including aerosols characterised by the additives
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D105/00—Coating compositions based on polysaccharides or on their derivatives, not provided for in groups C09D101/00 or C09D103/00
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
  • C09D5/04—Thixotropic paints
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K3/00—Materials not provided for elsewhere
  • C09K3/18—Materials not provided for elsewhere for application to surfaces to minimize adherence of ice, mist or water thereto; Thawing or antifreeze materials for application to surfaces
  • C09K3/185—Thawing materials

Definitions

• the present provides a non-toxic anti-icing or deicing fluid for use on surfaces.
• This invention typically relates to an aqueous, non-electrolytic, essentially non-toxic, easily biodegradable, benign, continuous single phase, environmentally- friendly, anti-icing and/or deicing fluid (or composition) for use in the removal of ice and/or for protection against further icing-up by acting as a barrier to the formation of or the adhesion of ice by liquid coating on substrate surfaces.
• the compositions are also useful to produce a transparent coating on surfaces which causes the surface to be a barrier to graffiti and facilitates its removal.
• the fluid typically has a composition of water, non-toxic freezing point depressant(s), at least one non-toxic thickener, e.g.
• a monohydric aliphatic alcohol is optionally present as a surface modifier as a means for forming a hydrophobic thin layer on the surface of the fluid structure.
• the alcohol is 1-dodecanol, which unexpectedly performs its intended functions when present in small amounts.
• the sugar is a hetreopolysaccharide, preferably a xanthan.
• the composition of water, freezing point depressant, and sugar, e.g., a xanthan when placed on the surface of an object has unexpectedly high static viscosity (higher than that of the prior art), a pseudoplastic viscosity-shear response, and also rapid recovery of high static viscosity for improved durability.
• the high static viscosity, achieved by a small amount of incorporated xanthan is thus an unexpected result, and produces a fluid protective barrier to ice accretion that is very durable and long lasting for anti-icing or deicing.
• the rapid viscosity drop induced by increase in shear rate is a desirable feature that enables ease of fluid application and uniformity of distribution.
• the fluid is typically non-toxic and is biodegradable under normal atmospheric temperature, soil, and aquatic conditions.
• Description of the Problem and Related Art The present invention addresses major problems caused by snow, sleet, ice, frost and the like as they exist or as they form on the surfaces of objects.
• ice it is to be understood that the term encompasses all forms of frozen water by whatever names they are known. The following icing problems in the art are presented.
• Ice protection fluids such as those commonly referred to in the art as Type II compositions, are suitable for application to all naval vessels, including their weather decks and even carrier flight decks.
• Aircraft Icing weather conditions produce especially acute problems to aircraft that are temporarily parked on the ground between flights where they can accumulate a variety of frozen precipitation, such as snow, sleet, hail, frost, hoar frost, slush and particularly ice.
• frozen precipitation such as snow, sleet, hail, frost, hoar frost, slush and particularly ice.
• These accreted deposits which form more readily on flat horizontal surfaces such as wings and empennage, can have serious consequences, for example, the aerodynamic performance characteristics of airfoils (e.g. lift and drag) may be degraded by even small accumulations of frozen water, making removal prior to flight important.
• Aircraft icing prior to takeoff is a significant problem.
• NTSB National Transportation Safety Board
• icing has been identified as the cause of 127 fatal accidents in which 496 lives were lost between 1977 and March 1992.
• Federal Aviation Administration (FAA) regulations require that all ice and snow accumulated under freezing conditions be removed from the aircraft prior to takeoff.
• aircraft operated during cold weather (icing) conditions are sprayed with fluids to remove ice (deicing) or to prevent ice and snow accretions (anti-icing) as a safety precaution.
• the aviation regulatory agencies e.g. FAA
• Table IA shows the Association of European Airlines (AEA) guide for suggested icing treatment procedures for various ambient air temperatures at the airport.
• AEA Association of European Airlines
• Table IB shows the AEA suggested guidelines, correlating holdover times after application of Type II certified fluids with current local weather conditions. Type II anti-icing fluids are applied at ambient temperatures.
• the second approach is to remove all ice and snow with a hot spray and then quickly spray a modified (thickened) FPD fluid (Type II) onto the aircraft surface that becomes a "thickened gel" which, acting as a protective blanket, provides a significantly longer time period of protection between the deicing step and aircraft's actual takeoff.
• Type II modified FPD fluid
• the two fluids that match these different approaches are termed Type I (unthickened) and Type II (thickened) fluids, respectively, in accordance with the Association of European Airlines (A.E. A.) standards.
• the properties of Type I and Type II fluids represent different compositions of the same family of FPD chemicals.
• Type II compounds usually contain thickening additives which cause the fluid to "cling" to the aircraft under various weather and pre-takeoff and taxi conditions, and then be shed automatically at a critical velocity close to (and lower than) the aircraft takeoff speed.
• This desirable shedding is achieved by the thickener's unusual property of having a very high viscosity until the takeoff s airflow shear rate dramatically lowers the viscosity to the point of where the fluid flows off rapidly as illustrated, for example, in Figures IA to IF.
• the viscosity-shear rate effect can be translated directly to viscosity-airspeed effect, which is a more practical correlation for aeronautical uses.
• Type II fluid's rheological properties have been correctly matched to the particular aircraft's takeoff performance, there are no appreciable amounts of anti-icing or deicing fluid remaining on the critical surfaces of the aircraft just prior to lift off and during climb acceleration.
• the known Type I (unthickened) fluids are described as having a rheological flow behavior known as Newtonian flow, that is, the fluid shows a constant slope straight line relationship between shear stress and shear rate. If shown on a plot, the straight line passes through the origin.
• Type II (thickened) fluids exhibit non-Newtonian flow characteristics, which are broadly defined as one for which the relationship of shear rate and shear stress is not constant. Thus, as shear rate is varied, the shear stress doesn't vary proportionately (refer, for example, to textbook Figure 3).
• the Type II fluid For the Type II fluid to perform as an ice barrier "blanket" protector, it must have very high static and near or quasi-static viscosity while there is little aerodynamic shear.
• the currently used toxic deicing fluids of the art are based on gly cols, primarily ethylene glycol, diethylene glycol, and propylene glycol. Significant evidence exists that these fluid formulations have detrimental affects on the environment (for example, see “Biodegradation & Toxicity of Glycols,” ARCO Chemical Company, Newton Square, PA 19073, May 1990; and “Toxicity of Aircraft De-icers and Anti-icer Solutions to Aquatic Organisms, " S. I. Hartwell et al, Chesapeake Bay Research and Monitoring Division, Maryland Dept. of Natural Resources, Annapolis, MD. 21401, May 1993, CBRM-TX-93-1).
• Ethylene glycol and diethylene glycol are in themselves toxic, while propylene glycol generally is not.
• the toxicity of these fluids of the art is enhanced.
• Type II fluids which have improved aerodynamic performance include compounds that are generally non-biodegradable. All of the currently used glycol deicing fluids fail to meet the U.S. Clean Water Act of 1987 environmental and safety requirements. The Environmental Protection Agency is imposing clean water rules which are stringent, and consequently costly, constraints on discharge at airports of these glycol-based fluids into storm water drains and ground water supplies.
• H.L. West et al. in U.S. Patent 2,373,727 teach a composition such as described by Kormamm, but also including a hydrocarbon, disclose a method and a composition for the prevention of the formation or accretion of ice on an exposed surface.
• the composition is for application to surfaces exposed to the deposition of ice to prevent the formation or accretion of ice.
• It comprises a jelly base composed of from about 7 to 17 percent by weight of a gelatinous material and from about 83 to 93 percent by weight of an antifreeze material of the class consisting of glycol, glycerol, polyglycols, polyglycerols and their mixtures, having incorporated therein from about 5 to 20 percent by weight of an organic liquid, which is immiscible with ice and water and which remains liquid at temperatures below plus 10°F.
• an antifreeze material of the class consisting of glycol, glycerol, polyglycols, polyglycerols and their mixtures, having incorporated therein from about 5 to 20 percent by weight of an organic liquid, which is immiscible with ice and water and which remains liquid at temperatures below plus 10°F.
• J.M. Fain et al. in U.S. Patent No. 2,716,067, discloses a composition of ethylene diamine and potassium thiocyanate, and optionally at least one of aqueous morpholine, potassium acetate or monomethyl amine.
• J.M. Fain et al. in U.S. Patent No. 2,716,068, discloses a composition of a glycol, and potassium thiocyanate, and optionally sodium nitrite.
• H.R. Schuppner in U.S. Patent No. 3,557,016, disclose to a useful combination achieved by adding some xanthan to locust bean gum.
• This composition includes (a) glycols, usually toxic ethylene glycol, (b) water, (c) 0.05 to 1.5 percent by wieght of a particular crosslinked polyacrylate, (d) 0.05 to 1 percent by weight of a mixed-base mineral oil which is insoluble in water, (e) surface-active agents, (f) corrosion inhibitors, and (g) alkaline compounds.
• glycols usually toxic ethylene glycol
• water water
• 0.05 to 1 percent by weight of a mixed-base mineral oil which is insoluble in water e
• surface-active agents e
• corrosion inhibitors e.g
• alkaline compounds alkaline compounds
• Xanthan is suggested only as a possible synergistic viscosity enhancer to the claimed thickener, and xanthan is always in the presence of one or more of the other thickeners. It is never used as a single thickener alone.
• the working examples the thickeners are always at 1 percent by weight of the total in addition to any xanthan present. Many other specific components are usually present.
• the pH value of the composition is 7.5 to 10.
• the agent... can also contain appropriate additives, preferably anti-oxidants and polysaccharides (gums) in effective quantities (gums and additional thickeners).
• polysaccharides have an advantageous effect on the rheological properties of crosslinked polyacrylates, particularly those having viscosity values in the lower range of the viscosity limits indicated above, that is within the range from about 1000 to 5000 cPs.
• Preferred polysaccharides are those of the type of high molecular xanthan gum"
• the composition includes (1) a polyhydroxy compound or monoalkyl ether thereof, (2) an organic non-volatile compound having at least one hydrophilic group, (2) being different than (1), and optionally a salt which functions to increase the viscosity and tackiness of the composition sufficient to retain the composition on non-horizontal surfaces to freeze proof the same.
• the composition comprises (A) a water- soluble polyhydroxy compound or monoalkylether thereof and (B) a water-soluble organic nonvolatile compound having a hydrophilic group such as amine, carboxyl or carboxylate groups in an amount to provide an effective amount, e.g., on the order of about 0.25 to 5 weight percent, of (A) plus (B) based on the weight of water.
• This method is especially useful for application to particulate solids, such as coal and mineral ores, which are shipped and stored in masses exposed to freezing temperatures. Any ice that is formed is physically weak and will not deter the unloading of the conditioned particulate solids.
• the deicing composition includes (a) an alkylene polyol, (b) an anionic surfactant capable of forming a hydrophobic monolayer on the metal surfaces of the aircraft, (c) a hydrophilic wetting agent which is capable of associating with the hydrophobic monolayer, and (d) a coupling agent, which facilitates the association between the wetting agent and monolayer.
• an alkylene polyol an alkylene polyol
• anionic surfactant capable of forming a hydrophobic monolayer on the metal surfaces of the aircraft
• a hydrophilic wetting agent which is capable of associating with the hydrophobic monolayer
• a coupling agent which facilitates the association between the wetting agent and monolayer.
• a dry and free-flowing composition is claimed containing (1) salt, (2) to C 6 monohydric and/or (3) polyhydric alcohol, (4) diatomaceous earth (or suitable substitute), and (5) sodium metasilicate characterized by a particle size smaller than about 80 mesh.
• the composition is useful for facilitating the melting and removal of snow and ice.
• the water soluble thickeners are made by alkoxylating monohydric alcohol hydrophobes.
• the monohydric alcohol has at least 18 carbon atoms to be properly hydrophobic.
• a large proportion of ethylene oxide is added, such that the molar ratio of ethylene oxide to monohydric alcohol hydrophobe is at least 40:1. Improved results are obtained when 8-15 moles of propylene oxide are added first as a block to the single mole of hydrophobe.
• the alkoxylations are necessary to provide the desired viscosities and hydrophilic nature.
• A.B. Ganncy in U.S. Patent No. 4,606,836, discloses a calcium magnesium acetate deicer of a particular pellet size.
• R.J. Tye, et al. in U.S. Patent No. 4,698,172, disclose an aircraft anti-icing fluid.
• the anti-icing fluid is suitable for ground treatment of aircraft.
• the anti-icing fluid is a glycol-based solution containing a gel-forming carrageenan, in an amount of less than 5 wt % .
• the carrageenan is present in the glycol-based solution in an amount sufficient to thicken the fluid to promote its adherence to aircraft surfaces when applied to a stationary aircraft.
• this thickened deicing fluid does not adversely affect airfoil lift characteristics during takeoff, because the fluid exhibits shear minning and readily flows off the aircraft surfaces when exposed to wind shear during the aircraft's takeoff run.
• D.A. Coffey et al. in U.S. Patent 5,389,276 disclose an ethylene glycol based deicing/anti-icing composition which contains a thickener comprising a polyacrylic acid.
• the present invention provides a non-toxic anti-icing fluid or a deicing fluid of water, freezing point depressant and thickener, wherein the fluid is a single phase.
• the present invention provides an anti-icing or deicing composition, which composition comprises:
• At least one non-toxic, water soluble, freezing point depressant selected from the group consisting of monohydric alcohols having from 2 to 6 carbon atoms, polyhydric alcohols having from 3 to 12 carbon atoms, monomethyl or monoethyl ethers of polyhydric alcohols having from 3 to 12 carbon atoms, or mixtures thereof;
• a non-toxic thickener which when combined with (a) and (b) provides a continuous liquid, wherein the liquid is a homogeneous, continuous single phase, and the liquid when formed has a high near-static initial viscosity when measured using a viscosity measuring device under specified conditions, and the formed liquid after being subjected to at least one external dynamic strain rate of at least 20.0 sec "1 for at least 1.0 min., has a second, lower viscosity as measured using the viscosity measuring device under specified conditions, and upon removal of the external dynamic strain rate, within 5 min. , said liquid has a third viscosity of within about 99.5% of the initial viscosity when the third viscosity is measured on the viscosity measuring device at the specified conditions.
• the present invention also provides an environmentally friendly composition which, as a coating on objects or structures (e.g. signs, walls, cars, etc.), provides protection for graffiti. That is, the novel coating (usually having glycerin as a component) prevents the adhering of the graffiti to a surface and the graffiti-coating are easily and quickly removed - e.g. using water usually under pressure.
• the novel coating usually having glycerin as a component
• in component (a) the water is present in between about 40 and 86 percent by weight of the combined water and freezing point depressant weights; in component (b) the freezing point depressant is present in between about 14 and 60 percent by weight of the combined water and freezing point depressant weights; and in component (c) the thickener is present in between about 0.01 and 10 perent by weight of the total composition, and the sum of components (a), (b) and (c) are about 90% or higher by weight or greater of the total composition, wherein the specified conditions are between about -20 and +20°C, and preferably wherein the specified conditions are about 20 °C and 760 torr.
• the present invention concerns an aqueous, non-electrolytic, essentially non- toxic, easily biodegradable, environmentaly benign, continuous phase liquid composition for use as an anti-icing or a deicing agent.
• the composition includes water, a non-toxic freezing point depressant, a thickener, optional one or more non- toxic environmentally benign corrosion inhibitors or surfactants, optional monohydric aliphatic unbranched alcohol, and optional coloring agent, wherein the thickener produces an aqueous liquid composition having the properties of non- Newtonian pseudoplastic rheological behavior wherein the near-static viscosity exceeds 20,000 cPs at temperature ranges of between about of -30°C and 0°C for icing protection and said viscosity rapidly decreases with moderate increase in shear rate to asymptomatically approach a low viscosity (below 600 cps), when a film of the composition is exposed to shear rates in excess of 20 reciprocal seconds.
• the present invention also relates to an aqueous, non-electrolytic, essentially non-toxic, easily biodegradable, environmentally benign, continuous single-phase, composition for use as an anti-icing agent and/or a deicing agent.
• These agents are for use on surfaces of an object, where ice accretion and build-up is detrimental, including but not limited to airplanes, airport pavements, roadways, bridges, walkways, entrances, electrical tower structures and their components, canals, locks, vessels, nautical components, railroad switches, automobiles, and motor vehicles.
• the unexpected static and dynamic icing protection properties of these novel, aqueous, non-toxic and biodegradable fluid compositions are equal to those of the present art and in most cases are superior to those of the art.
• the anti-icing/deicing composition comprises:
• a non-toxic freezing point depressant selected from the group consisting of monohydric alcohols having from 2 to 6 carbon atoms, polyhydric alcohols having from 3 to 12 carbon atoms, mono methyl or ethyl ethers of polyhydric alcohols having from 3 to 12 atoms or mixtures thereof, wherein the freezing point depressant is present in between about 10 to 60 percent by weight of the sum of the weights of the freezing point depressants and water;
• a thickener for producing resultant pseudoplastic flow behavior wherein the thickener preferably consists essentially of bacterium produced hydrophilic hetero-polysaccharide colloid which is present in between about 0.01 and 10 percent by weight of the total composition;
• the anti-icing/deicing composition can further include:
• a monohydric alcohol as means for forming a hydrophobic monolayer on the exterior surface of the fluid composition applied to the structure to be given ice protection, which alcohol is selected from the group consisting of alcohols having between 8 to 24 carbon atoms.
• the alcohol is a primary aliphatic alcohol with minimal or no sidechains, preferably present in between a trace quantity (i.e., between about 0.01 wt%) sufficient to form hydrophobic thin layers, essentially a monolayer, on the exterior surface, and 5.0 wt% of the total composition.
• the non-toxic freezing point depressant can be selected from the group of alkanols consisting of ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2- methyl-1-propanol, 2-mefhyl-2-propanol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, 1,3-butylene glycol, 2,3-butylene glycol, glycerol, and mixtures thereof.
• the freezing point depressant is present preferably in between about 14 and 60 percent by weight of the sum of the weights of the freezing point depressant and water; and in component (c), the thickener is a xanthan selected to impart viscosity thickening when dispersed or hydrated in the aqueous media.
• the xanthan is present in between about 0.01 and 10 percent by weight of the sum of the total composition.
• additional optional constituents which may be further incorporated to enhance overall performance include, for example:
• oxygenator(s) such as a water-soluble peroxide (i.e. H 2 O 2 ), which is added during application of the fluid to the surface to assist in subsequent biodegradation and is present in between about 0.1 and 5 percent by weight; or
• optional degradation agents which are present in amounts effective to facilitate biodegradation of the fluid after its use.
• Such agents include, but are not limited to enzymes, microbes, bacteria, and the like.
• Suitable degradation agents are optionally present between about 0.001 wt% and 2.0 wt%.
• these degradation agents are added just prior to fluid application or after use, to assist in biodegradation (and decomposition) of the runoff fluid composition after its use on the surface of the object; or (i) environmentally benign non-toxic (i.e., foodgrade) bacteriostat such as those described in the art, present between about 0.001 and 0.1 percent by weight.
• the anti-icing or deicing composition further includes a monohydric alcohol as a means for forming a hydrophobic thin layer, essentially a monolayer, on the exterior surface of the composition applied to the structure to be ice protected, which alcohol is selected from the group of monohydric alcohols having between 8 and 16 carbon atoms, preferably between 8 and 12 carbon atoms, and more preferably, 1-dodecanol.
• the fluid further includes 1-dodecanol which is present between about 0.01 and 5.0 percent by weight of the total composition.
• the present invention also relates to anti-icing or deicing compositions for use on the surfaces of objects such as, airplanes, runways; streets, roads, bridges, sidewalks, entrances, building and tower structures, vessels, nautical components, automobiles, trees, shrubs and the like.
• the anti-icing/deicing composition comprises:
• a non-toxic freezing point depressant selected from the group consisting of mono hydric alcohols having from 2 to 6 carbon atoms, polyhydric alcohols having from 3 to 12 carbon atoms, mono methyl or ethyl ethers of polyhydric alcohols which have from 3 to 12 atoms or mixtures thereof, wherein the freezing point depressant is present between about 14 to 60 percent by weight; (c) a selected xanthan present in between about 0.01 and 5 percent by weight;
• an environmentally benign non-toxic (i.e., foodgrade) bacteriostat such as those described in the art, e.g. cetylpyridinium chloride, benzylpyridinium chloride between about 0.001 and 0.1 percent by weight.
• the anti-icing or deicing composition further includes component (f) a monohydric alcohol as means for forming a hydrophobic thin layer, essentially a monolayer, on the exterior surface of the fluid composition as applied to the structure to be given ice protection which alcohol is selected from the group consisting of alcohols having between 10 to 20 carbon atoms.
• the anti-icing or deicing composition further includes component (g) an environmentally friendly non-toxic surfactant such as these described in the art, between about 0.001 and 0.1 percent by weight.
• the freezing point depressant is selected from the group consisting of ethanol, 1-propanol, 2- propanol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, 1,3- butylene glycol, 2,3-butylene glycol, glycerol, and mixtures thereof.
• the ratio of freezing point depressant is present between about 14 and 60 percent by weight of the sum of the weights of freezing point depressant and water; and in component (c), and the thickener, xanthan, is present in between about 0.01 and 10 percent by weight.
• the composition further includes a monohydric alcohol as means for forming a hydrophobic monolayer on the exterior surface of the composition as applied to the structure to be ice protected, which alcohol is selected from the group of monohydric alcohols having between 10 and 14 carbon atoms, preferably 1- dodecanol.
• the anti-icing/deicing composition further includes a liquid aliphatic wax ester as an optional means for forming a hydrophobic monolayer on the exterior surface of the fluid composition as applied to the structure to be ice protected, which liquid wax comprises natural occuring esters of cis- monounsaturated omega-9 C 16 to 4 linear fatty acids and 8 to 6 linear alcohols, with an overall chain length predominantly C 40 to C 44 , preferably "Jojoba" as derived from the seeds of the Simmondsia chinensis plant.
• a liquid aliphatic wax ester as an optional means for forming a hydrophobic monolayer on the exterior surface of the fluid composition as applied to the structure to be ice protected, which liquid wax comprises natural occuring esters of cis- monounsaturated omega-9 C 16 to 4 linear fatty acids and 8 to 6 linear alcohols, with an overall chain length predominantly C 40 to C 44 , preferably "Jojoba" as derived from the seeds of the Simmondsia chinensis
• the anti-icing or deicing composition may be desirable to use on a surface, with small grit sized, preferably biodegradable, solid particles, to increase friction and/or traction on the surface (e.g. in roads or sidewalks).
• small grit sized preferably biodegradable, solid particles
• aircraft surfaces will not include grit.
• a composition consists essentially of water, a non-toxic freezing point depressant (described above), a xanthan and an optional monohydric aliphatic alcohol (described above) and optionally a corrosion inhibitor and optionally a bacteriostat.
• the present invention relates to an anti-icing or deicing composition for use on surfaces of objects where ice accretion is detrimental and when protection from ice build-up is desired which anti-icing or deicing composition comprises:
• a non-toxic freezing point depressant selected from the group consisting of monohydric alcohols having from 2 to 6 carbon atoms, polyhydric alcohols having from 3 to 12 carbon atoms, mono methyl or mono ethyl ethers of polyhydric alcohols having from 3 to 12 aoms or mixtures thereof, wherein the amount of freezing point depressant is between about 14 to 60 percent by weight;
• a thickener for producing resultant pseudoplastic flow behavior of the composition which thickener is present in between about 0.01 and 10 percent by weight;
• a non-toxic environmentally benign corrosion inhibitor which is present in between about 0.01 and 0.1 percent by weight of the total composition, or (e) optionally an environmentally benign, non-toxic (i.e., foodgrade) bacteriostat such as those described in the art, between about 0.001 and 0.1 percent by weight.
• the present invention relates to an anti-icing or deicing composition
• the freezing point depressant is selected from the group consisting of ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-l- propanol, 2-methyl-2-propanol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4- butylene glycol, 1,3 -butylene glycol, 2,3-butylene glycol, glycerol, and mixtures thereof
• the thickener is xanthan selected to impart viscosity thickening when dispersed or hydrated in the aqueous media, and the xanthan is present in between about 0.01 and 5 percent by weight, and the freezing point depressant is between about 14 and 60 percent by weight
• the objects are selected from the group consisting of aircraft, airport pavements, roadways, walkways, bridges, entrances, structures, canals, locks,
• the present invention relates to an anti-icing or deicing composition for use on the surfaces of objects, which anti-icing or deicing composition comprises:
• a non-toxic freezing point depressant selected from the group consisting of mono hydric alcohols having from 2 to 6 carbon atoms, polyhydric alcohols having from 3 to 12 carbon atoms, mono methyl or mono ethyl ethers of polyhydric alcohols having from 3 to 12 atoms or mixtures thereof, wherein the amount of freezing point depressant is between about 14 to 60 percent by weight of the sum of the weights of FDP(s) and water;
• the present invention relates to an anti-icing or deicing composition
• the freezing point depressant is selected from the group consisting of ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-l- propranol, 2-methyl-2-propanol, 1 ,2-propylene glycol, 1,3 -propylene glycol, 1,4- butyleneglycol, 1,3-butylene glycol, 2,3-butyleneglycol, glycerol, and mixtures thereof, and the freezing point depressant is between about 30 and 60 percent by weight of the sum of the weights of FDP(s) and water; and in component (c), the xanthan is present in between about 0.1 and 1 percent by weight; and the objects are selected from the group consisting of aircraft, airport pavements, roadways, walkways, bridges, entrances, structures, canals, locks, components, vessels, nautical components, railroad switches, and motor vehicles.
• the present invention relates to an anti-icing or deicing or anti-icing composition for use on the surfaces of objects, which anti-icing or deicing composition consists essentially of:
• a non-toxic freezing point depressant selected from the group consisting of mono hydric alcohols having from 2 to 6 carbon atoms, polyhydric alcohols having from 3 to 12 carbon atoms, mono methyl or mono ethyl ethers of polyhydric alcohols having from 3 to 12 atoms or mixtures thereof, wherein the amount of freezing point depressant is between about 40 to 60 percent by weight of the sum of the weights of FDP(s) and water; (c) a xanthan which is present in between about 0.01 and 10 percent by weight; and
• the present invention relates to an anti-icing or deicing composition which further includes solid particle means for increasing friction and traction in the composition on the surface to be anti-iced or deiced, wherein said solid particles are present in between about 0.1 and 20 percent by weight of the sum of the solid particle means and the fluid composition.
• the present invention relates to an anti-icing or deicing composition for use in motor vehicle surface applications: in subpart(b) the non-toxic freezing point depressant is a mixture of propylene glycol present in about 5 to 15 weight percent, and isopropanol about 40 to 55 weight percent of the sum of the weights of the FPD(s) and water, and optionally further includes 1-dodecanol in between about 0.01 and 5.0 weight percent.
• the non-toxic freezing point depressant is a mixture of propylene glycol present in about 5 to 15 weight percent, and isopropanol about 40 to 55 weight percent of the sum of the weights of the FPD(s) and water, and optionally further includes 1-dodecanol in between about 0.01 and 5.0 weight percent.
• the present invention relates to an anti-icing or deicing composition for aircraft surfaces, said composition having a near-static viscosity at a shear rate of about 0.1 sec 1 of 25,000 to 75,000 cPs and a shear thinned viscosity at a shear rate greater than 20 sec 1 , below 1000 cPs, at a temperature of between about 0° and -20 °C.
• the present invention relates to an anti-icing or deicing composition having a near static viscosity of between about 20,000 to 120,000 cPs at between about 0° and -20°C.
• Figures IA, IB, IC, ID, IE and IF are each a graphic and pictoral representation of the rheological behavior of conventional Type II FPD fluids (for example, ABC-3 of KILFROST * , (a deicing fluid of KILFROST Ltd,
• Figure 1 A is a graph of viscosity versus aircraft speed at brake release.
• Figure ID is a cross-sectional representation of the wing (11) covered on the top with Type II fluid (12) at aircraft brake release.
• Figure IB is a graph of viscosity versus aircraft speed during takeoff roll.
• Figure IE is a cross-sectional representation of the wing (11) partially covered on top with Type II fluid (13) during the aircraft takeoff roll.
• Figure IC is a graph of viscosity versus aircraft speed at rotation.
• Figure IF is a cross-sectional representation of the wing (11) having most of the Type II fluid (14) removed at the speed of aircraft takeoff.
• Figure 2 is a textbook graphic representation of the invariant or constant apparent viscosity of a typical Newtonian behaving fluid when subjected to varying shear rates, at constant temperature.
• Figure 3 is a textbook graphic representation of a non-Newtonian fluid, typical of a xanthan thickened FPD fluid representative of the compositions of this invention. It shows both the characteristic pseudoplastic flow behavior and the Ellis type flow behavior yield value.
• Figure 4 is an overall, idealized, textbook graphic representation of the germane flow behavior of generic types of non-Newtonian fluids whose viscosity properties vary with shear rates.
• Figure 5 is a graphic, textbook log-log presentation of the idealized Ellis- type, pseudoplastic flow behavior of a typical xanthan thickened FPD fluid of this invention. It highlights the near-zero shear viscosity C ⁇ ,,) at and about the "yield point” and the infinite shear rate viscosity ( ⁇ j, with power law behavior between these points.
• Figure 6 is a graphic representation typical of the compositions of the prior art presenting the apparent viscosity in centipoise (cPs) versus shear rate (sec _1 ), as taken from Figure 1 of Tye, et al, U.S. 4,698,172 (original in semi-log plot), and compared in that patent with measured values for Hoechst 1704 * Type II (icing protection fluid of Hoechst AGF, Frankfort, Germany), and intended to show superior properties of that invention's thickener, carrageenan gum.
• cPs centipoise
• sec _1 shear rate
• Figure 7 is a graphic representation of the present invention's composition of water (44.5 wt%), isopropyl alcohol (55 wt%), and xanthan (0.5 wt%) showing the response of the apparent viscosity in centipoise versus the shear rate at 20°C.
• Figure 8 is a graphic representation of apparent viscosity versus shear rate.
• Figure 9 is a graphic representation of the apparent viscosity versus shear rate for one embodiment of the present invention's composition of water (44.5 wt%), propylene glycol (55 wt%) and xanthan thickener (0.5 wt%), at -20°C, 0°C, and +20°C. Note particularly, the higher near static viscosity and rapid shear- thinning of the viscosity of a composition of the present invention.
• Figure 10 is a graphic representation of the magnified, low shear rate portion of the -20 °C shear rate of Figure 9.
• Figure 11 is a graphic representation, of one embodiment of the present invention, of apparent viscosity and shear rate for water (44.625 wt%), propylene glycol (55 wt%) and xanthan thickener (0.375 wt%) at 0°C and +20°C.
• Figure 12 is the magnified, low shear rate portion of the shear rate of Figure 11, and further includes behavior at -20 °C.
• Figure 13 is a graphic representation of one embodiment of the present invention showing apparent viscosity and shear rate for water (44.75 wt%), propylene glycol (55 wt%) and xanthan thickener (0.25 wt%) at 20°C.
• Figure 14 is a semi-log plot of embodiments of the present invention at 0.25, 0.375 and 0.5 wt% xanthan thickener. It demonstrates the linear relationship of the near-static viscosity of a 55 wt% FPD fluid with changes in concentration of the xanthan at 20°C.
• Figure 15 is a graphic representation of the apparent near-static viscosity
• Figure 17 is a graph similar to Figure 16, but using data characteristic of a different composition of the present invention as shown for 55.0 wt% propylene glycol, 0.5 wt% xanthan, and 44.5 wt% water.
• Figure 18 is a graphic textbook representation of the rheological moduli typical of a classically behaving elastic type liquid, showing that elastic modulus has a stronger contribution to shear stress ( ⁇ ) than does viscous modulus, as indicated by angle ⁇ .
• Figure 19 is a graphic textbook representation of the rheological moduli typical of a classically behaving viscous type liquid, showing, as opposed to the type of Figure 18, that the viscous modulus is dominant, and hence a stronger factor on temperature effects.
• Figure 20 is a graphic textbook representation of the rheological behavior of a Newtonian fluid and a pseudoplastic Type II anti-ice or deicing fluid (ADF), for example, as shown in Figure 10.
• ADF pseudoplastic Type II anti-ice or deicing fluid
• Figure 21 A is a textbook graph which shows a characteristic curve for viscosity versus shear strain rate for a pseudoplastic and a Newtonian fluid.
• Figure 21B is a textbook graph which shows a characteristic curve for shear stress versus shear strain rate for a Newtonian and pseudoplastic fluid.
• Figure 22A is a textbook graph of a curve of viscosity versus shear rate for a thixotropic fluid.
• Figure 22B is a textbook graph of a curve of shear stress versus shear rate for a thixotropic fluid.
• Figure 23 is a textbook graph of a curve for apparent viscosity versus time at constant shear for a thixotropic fluid.
• Figure 24 is a textbook graph of a curve for viscosity versus shear strain rate for a non-recovering, thixotropic viscosity reduction through three shear cycles.
• Figure 25 is a graphic representation of the cold storage stability, characteristic of this invention's fluid composition.
• the viscosity versus shear rate rheological data presented in the figure represents the results of evaluating small portions, each taken from the fluid stored in a freezer in a closed glass container. These samples were warmed slowly to room temperature (around +20°C), also in a closed glass container, and then evaluated for shear rate dependency of viscosity using the same laboratory Brookfield viscometer that was used throughout the development work herein. A comparison was made of each sample's characteristic with the original data. No changes were observed throughout the test series, which lasted for over 106 days of cold storage viscosity tests (and continues).
• Figure 26 is a photograph of a 3M "SCOTCHLITE ® " coated aged stop sign in colors of red and white and a portion is first coated with the composition and then sprayed with black lacquer.
• Figure 27 is a photograph of the sign of the Figure 26 after contact with water under mild pressure.
• Figure 28 is a photograph of a new sample of 3M SCOTCHLITE ® material, coated with the composition, dried, contacted with black spray laquer, dried and contacted with water at low pressure.
• Figure 29 is a photograph of a commercial painted road sign first completely covered with composition of Example 13 and dried.
• Figure 30 is a photograph of the sign of Figure 29 after contact with commercial black spray can lacquer.
• Figure 31 is a photograph of the coated graffitied sign of Figure 30 showing a stream of water washing away the black lacquer.
• Figure 32 is a photograph of the coated sign of Figure 31 wherein virtually all the black lacquer is removed.
• Figure 33 is a photograph of a commercial porous concrete stepping block wherein a portion is first contacted with the composition of Example 13, dried in the shape of a capital Z, contacted with black spray can lacquer, dried and washed with low pressure water to remove portions of the lacquer.
• Figure 34 is a photograph of Figure 33 without the added lines to show the prior layer of black spray can lacquer in the form of the letter "Z".
• Figure 35 is a photograph of sign of Figure 29 which is first completely coated with the composition of Example 13. Green spray can enamel is sprayed into the coated surface.
• Figure 36 is a photograph of the dried enamel of Figure 35 which is partially removed using low water pressure.
• Figure 37 is a photograph of the sign of Figure 36 wherein all the dried enamel is completely removed.
• the figures included here present representative rheological characteristics of various compositions typical of some of the embodiments of the invention herein. They graphically demonstrate some improved properties of these new compositions, and in many examples, how these non-toxic compositions have properties which exceed those of the known art, e.g., KILFROST ABC-3 * ; HOECHST 1704 * ; UCAR ULTRA * ; and OCTAGON FORTY BELOW * .
• Alginate refers to any of several derivatives of alginic acid (e.g., calcium, sodium or potassium salts or propylene glycol alginate). They are hydrophilic colloids (hydrocolloids) obtained from seaweed. Sodium alginate is water-soluble but reacts with calcium salts to form insoluble calcium alginate. Algenates are commonly used as food additives. "Ambient conditions” refers to those pressure, temperature, humidity, etc. conditions of the actual environment. Typically ambient conditions are about 20°C and 760 torr.
• Anti-graffiti refers to a coating which causes a surface to resist marking by paint, enamel, lacquer, ink and the like.
• Anti-icing refers to the general term in this art. It usually describes the use of some external force, heating, shock, a liquid (gel) composition; whose function is to slow or to stop the icing process or to render any icing which might occur to be easily removed.
• Biodegradable refers to the eventual decomposition of the fluid after use by the action of the environment, e.g. microorganisms resulting in innocuous end products.
• Carrageenan refers to a sulfated phycocolloid.
• the aqueous, usually gel- forming, cell-wall polysaccharide mucilage is found in the red marine algae (Chondrus crispus and several other species) and from red seaweed (Rhodophyceae). It is commonly used as an emulsifier in food products, etc.
• Continuous single phase refers to the property of a fluid such that there is no abrupt discontinuities of physical properties throughout its bulk.
• the present invention is essentially free of mineral oil or any other water insoluble liquid (e.g. less than about 0.25 wt. percent).
• Deicing refers to the general term in this art, which usually describes the use of some external force (e.g. a hot liquid composition, scraping, lowering the freezing point, etc.) to remove ice already formed on a surface.
• some external force e.g. a hot liquid composition, scraping, lowering the freezing point, etc.
• Effective amount refers to the amount sufficient to provide the desired properties of anti-ice or deice to meet the particular application requirements, for example, a clear automotive windshield.
• "Ellis fluid” is defined as a pseudoplastic fluid with a well defined yield point or yield stress which must be overcome before flow commences, and that flow follows the pseudoplastic model.
• Xanthomona campestris thickened fluids of the present invention being Ellis fluids in behavior, do not exhibit any thixotropic (nor rheopectic) characteristics. Therefore, they do not have time-dependent plasticity in their rheological performance. Fluids thickened with, for example, a xanthan of this invention behave as an Ellis fluid.
• Environmentally benign means that the impact to the environment by the component or composition under normal use conditions is not harmful to plant or animal health.
• Gramfiti refers to the undesirable marking of a surface with paint, enamel, lacquer, ink, etc. usually for the purpose of defacing the surface.
• Halzardous or toxic materials refers to those compounds so designated by the Environmental Protection Agency (EPA), 40 CFR 261.33 (1994).
• “Holdover time” is the expected aircraft icing protection time of the anti- icing fluid under various weather conditions.
• the estimated protection time is the time interval between the beginning of the anti-icing operation and the inability of the fluid to protect water on the wing from freezing. As mentioned earlier in the discussions of Tables IA and IB, it is difficult to accurately predict the holdover time or the protection time for the known art compositions.
• “Monolayer” refers to a single continous layer or film that is one cell or molecule in thickness.
• Neutral when referring to the total composition means a pH of between about 6.9 and 7.1 preferably about 7.0.
• Non-electrolytic refers to the inherent non-ionic non-conductivity property of the fluid since it contains no ionic species (i.e. salts) in the composition.
• Non-Newtonian fluids refer to fluids which exhibit different apparent viscosity values when tested at the same temperature, and with the only parameter variant being that of rate of shear. Non-Newtonian fluids show changing viscosity with changing shear rate. There are five types of non-Newtonian fluids; three which are shear rate dependent (dilatant, pseuodplastic, and Ellis, see textbook Figures 21 A and 2 IB) and two which are time dependent (rheopectic and thixotropic). One of the shear rate dependent types is pseudoplastic, in which the apparent viscosity decreases with increasing shear rate until finally leveling out at very high shear rates.
• Textbook Figure 21A shows an example of the characteristic viscosity
• Figure 2 IB shows an example of the shear stress versus shear rate curves for pseudoplastic non-Newtonian fluids.
• thixotropic in which viscosity decreases with time under exposure to a constant shear stress such as gravity.
• Thixotropic fluids are complex because their visicosities are, in reality, dependent both on time and shear rate (textbook Figures 22 A and 22B).
• a thixotropic fluid does not follow the same stress and viscosity curves when shear strain is applied and then removed. Further, thixotropic behavior may be either recoverable or nonrecoverable. This is, if after being subjected to the shear cycle shown in textbook Figures 22 A and 22B, a fluid is static, some fluids will recover the viscosity reduction ⁇ and start the next shear cycle at the original viscosity level.
• an undesired characteristic of thixotropic compositions is the time dependent plasticity or flow under an applied constant stress.
• Figure 23 shows this behavior of thixotropic fluids, as responding, for example, to the constant shear force caused by gravitational effect.
• Other fluids however, do not recover to the original viscosity value, but instead begin each shear cycle at progressively lower viscosities as shown in the textbook Figure 24.
• the current A.E.A. type ⁇ fluids exhibit both pseudoplastic and thixotropic behavior.
• the pseudoplastic behavior of the fluid allows it to remain thick and cling to a stationary or taxiing aircraft, but thin out and blow off as shear forces (due to high speed wind during acceleration for takeoff) act upon it.
• the thixotropic property of the fluid makes it difficult to handle, because of "shear damage", wherein the original level of high viscosity is never attained again.
• thixotropic rheological behavior is a very undesirable property for these fluids.
• Non-toxic refers to the benign nature of the interaction of the component or composition with respect to the tolerance by specific plant or animal organisms (i.e. vegetables, animals, humans, and aquatic life), at the concentrations of normal use.
• Non-toxic therefore refers to those compounds that are General Recognized As Safe (GRAS) for direct addition to human food by the Federal Drug Administration (FDA) standards, or compounds which are practically non-toxic to aquatic life as defined by the U.S. Fish and Wildlife Service, U.S. Department of Interior under the conditions for the use of the invention for anti-icing or deicing purposes.
• GRAS General Recognized As Safe
• FDA Federal Drug Administration
• the LD 50 of the composition for rat
• the LD 50 of the composition is about 1 g/kg or greater.
• Protection time refers to the useful time provided by the deicing step, there are many variables affecting the protection time: e.g. wind velocity, precipitation rate, outside air temperature (OAT), aircraft skin temperature, solar radiation, types of precipitation or other hydrometeorological deposits (drizzle, rain, freezing drizzle, freezing rain, snow, snow pellets, snow grains, ice pellets, hail, hailstones, ice crystals, dew, frost, hoar frost, rime, glaze, and/or blowing snow), jet blast from other aircraft, sudden changes in temperature or precipitation type or rate, etc. All these can affect the holdover protection time.
• OAT outside air temperature
• Propylene glycol refers to 1 ,2-propanediol (the product of the hydrolysis of propylene oxide). The term may also include the 1,3-propanediol isomer.
• centipoise refers to centipoise, a unit(s) measure of viscosity, and is interchangeable with “mPaS", milli Pascal seconds.
• Specified conditions refers to those conditions to perform physical property measurements, e.g. viscosity.
• the temperature can be between about -20 and +20°C and at ambient pressure. More preferably, the temperature are each about -20, -10, 0, +10, +20°C.
• Static viscosity and near static viscosity are terms which refer to the viscosity of the pseudoplastic fluid at the onset of flow resulting from low shear rates (i.e., 0.102 sec "1 , or less).
• Thixotropy refers to a non-Newtonian rheological flow behavior where viscosity depends on the shear history. The viscosity decreases with time at a constant shear rate, has an initial yield point characteristic of a solid, and behaves with time dependent plasticity with a reversible time dependent recovery. That is, the state changes from gel to sol to gel, and behaves the opposite to "rheopectic" materials.
• Viscosity and "apparent viscosity” are, for purposes herein, used interchangeably, and without being bound by theory. They refer to all measured viscosities presented here (i.e., as measured by the Brookfield Viscometer). They are derived by the device by determining the ratio of the torque ( ⁇ ) to shear speed(s). Absolute viscosity ( ⁇ / ⁇ s) is obtained by calculating the ratio of incremental torque ( ⁇ ) to speed increment ( ⁇ s).
• Weight percent refers to the weight of that constituent, per hundred ratio, with respect to total weight of the combined composition, unless otherwise specified.
• Xanthan generally refers to variety of synthetic, water-soluble (either hot or cold) hydrophilic heteropolysaccharide colloid polymers, e.g. one made by in- vitro fermentation of carbohydrates by the bacterium xanthomonas campestris.
• the xanthan polysaccharide colloids to be used in accordance with this invention and their preparation are described in U.S. Pat. No. 3,557,016. They are known commercially available food thickening and suspending agents that are heat-stable, with a tolerance for strongly acidic and basic solutions.
• the solutions have stability and compatibility with high concentrations of salts (sodium chloride 15% and calcium chloride 25%). The viscosity remains stable over wide temperature ranges (-18°C to +80°C) and over wide pH ranges (1 to 11).
• high molecular-weight polymeric dispersions exhibit forms as non-Newtonian flow, most often pseudoplastic to some extent, and is characteristic of aqueous solutions of polysaccharides. It is well known in literature describing the art for the use of xanthan gum, that these certain polysaccharides dissolve in water to form solutions; that is, homogeneous single phase aqueous constituents.
• xanthan gum ENCYCLOPEDIA OF CHEMICAL TECHNOLOGY. Third Ed. Vol 12 (1980), John Wiley & Sons, N. Y., which describes on page 62 that, "Xanthan gum is a cream-colored powder that dissolves in either hot or cold water to produce solutions with high viscosity at low concentration.
• Xanthan aqueous colloidal solutions of the embodiment compositions of this invention display excellent viscosity versus shear rate characteristics, and have no time-dependent plasticity behavior.
• the fluid flow behavior shown in Figure 5, highlights the zero-shear viscosity ( ⁇ 0 ) and infinite-shear viscosity ( ⁇ ⁇ ) with power law behavior in between these two limits.
• This initial yield stress characterizes the xanthan thickened fluids of this invention as an Ellis (or non- Bingham plastic) variant of pseudoplasticity, and the Ellis curve in Figure 4.
• This thickener has an initial value of infinite shear stress (known as yield stress). That initial resistance, which must be exceeded to initiate flow, can be determined for each set of conditions such as fluid temperature and thickener concentration, leading to the development of a "smart fluid" or ice protection. This fluid and its properties are described in detail in the text below.
• a thickener discovered to possess the unexpectedly desirable features of the present invention is a select xanthan, the hydrophobic polysaccharide colloid described above. Its use imparts surprisingly improved Type U fluid properties, and is compatible with essentially all FPD fluids tested (including mixed glycols).
• a comparison of a fluid of the present invention with a current commercially used Type II fluid KILFROST ABC-3 * is shown in Figure 8. This figure highlights the rheological performance of a composition typical of the fluid composition of this invention, and compares its dramatic viscosity decline with shear rate to that of the KILFROST ABC-3 * . This behavior can be described as, "like going from lime sherbet to limeade during takeoff roll".
• the present invention improves on fluids of the art, and claims compositions different from any presently used, as is described hereinbelow. Further, the present invention results in a new series of compositions of such fluids that are superior to those presently known of the prior art in essentially all significant properties, including, but not limited to, rheological flow behavior; resistance to mechanical (hysteresis) damage to viscosity; shelf-life (in excess of three years); hold over times (in excess of 36 hrs); resistance to drizzle dilution; and the ability to be foamed in- situ or be varied in composition in-situ (“a smart fluid”) to meet specific requirements.
• icing particularly for aircraft, which fulfills the demands mentioned initially, and particularly those relating to the important properties, namely, controlled stability against shear, controlled viscosity, rheological behavior (this is, in particular, the controlled viscosity and controlled flow behavior at a low and at a very high shear rate), holdover time, and particularly, low toxicity and facile environmental degradation.
• Figures 7, 8, 9, 10 and 11 show the rheological behavior of compositions of this invention.
• Figure 7 is a graphic representation of the present composition of water (44.5 wt%), isopropyl alcohol (55 wt%), and xanthan (0.5 wt%) showing the response of the apparent viscosity in centipoise versus the shear rate at 20 °C. Note the similarity of this flow behavior to that of the composition shown in Figure 9.
• Figure 8 is a graphic representation of apparent viscosity versus shear rate. It compares the commercially available deicing composition KILFROST ® ABC 3 (propylene glycol with toxic and environmentally detrimental additives) with a version in accordance with this invention having an approximate composition of water (44.5 wt%), isopropyl alcohol (55 wt%), and xanthan (0.5 wt%). Note the higher near static viscosity and rapid shear thinning of the composition of the present invention.
• Figure 9 is a graphic representation of the apparent viscosity versus shear rate for one embodiment of the present invention's composition of water (44.5 wt%), propylene glycol (55 wt%) and xanthan thickener (0.5 wt%), at -
• Figure 10 is a graphic representation of the magnified, low shear rate portion of the -20 °C shear rate of Figure 9. It shows the maximum variation emphasized.
• Figure 11 is a graphic representation of one embodiment of the present invention of apparent viscosity and shear rate for water (44.625 wt%), propylene glycol (55 wt%) and xanthan thickener (0.375 wt%) at 0°C and glycol (55 wt%) and xanthan thickener (0.375 wt%) at 0°C and +20°C.
• Figure 12 is the magnified, low shear rate portion of the shear rate of Figure 11, and further includes behavior at -20 °C. It shows the maximum variations emphasized.
• Figure 13 is a graphic representation of one embodiment of the present invention showing apparent viscosity and shear rate for a composition of water (44.75 wt%), propylene glycol (55 wt%) and xanthan thickener (0.25 wt%) at 20°C.
• Expensive low shear pumps and special handling that current Type U fluids require is not needed; thus eliminating a two step process using two different fluid types, one to deice and one to provide anti-ice protection and additional equipment.
• the fluid of the present invention exhibits no viscosity loss due to pump-shear effects or rough handling; thus, its use reduces the uncertainty that the currently used fluids' unknown prior shear damage histories may place on the safety of the aircraft.
• the compositions of the present invention are also much more shear rate sensitive than currently used Type II fluids. This means the initial static viscosity can be and is significantly higher, resulting in more effective adherence (creating a better ice protection blanket) and less fluid usage. Due to the small quantity of thickener needed, it is very cost effective.
• Figure 8 shows the improved viscosity performance of the compositions of the present invention as compared to the fluids of the prior art. Higher static viscosities typically equate to longer holdover times; a feature deemed desirable for aircraft ice protection. For aircraft applications, it is important to note that the static viscosity of the present invention's composition (as shown in Figure 8) is about a factor of at least ten higher than that of the prior art's upper value ( ⁇ .
• the fluid composition of the present invention has higher static viscosity which drops quickly in response to increasing shear rate until is asymptotically falls to the same low value ( ⁇ j of viscosity found in the prior art fluids, and is achieved in the equally brief span from 0 to 20 reciprocal seconds (20 sec "1 ).
• the higher static viscosity characteristics of fluid compositions of this invention have a direct correlation with holdover time. That is to say, the higher static viscosity equates to longer holdover times, which is highly desirable. Yet the fluid's behavior of the rapid viscosity drop to the lower value is also a very desirable characteristic because it assures proper shedding from the aircraft's surfaces during takeoff for maximum effectiveness.
• Figures 9 to 13 also show the typical temperature response of viscosity versus shear rate for the compositions of the present invention.
• the compositions of the present invention are superior, e.g. viscosity, non-toxic, neutral, etc. with the same propylene glycol as the FPD.
• the trisaccharide side chains (two mannos, and one glucuronic) on alternating anhydroglucose units is the feature that distinguishes this moiety from cellulose, plus the pyruvate species at most terminal mannose units.
• xanthomonas polysaccharides e.g. xanthans
• xanthomonas campestris of the preferred embodiments were examined as potential candidates for use as thickners for the aqueous freezing point depressant (FPD) embodiments of this invention.
• FPD freezing point depressant
• Some of these xanthomonas, for example, those described by Schuppner, (supra) are listed in Table 2. Those four listed in Table 2 with an asterisk are deemed most suitable as potential candidates, based on the relatively high viscosities at shear rates of 10.2 sec. "1 .
• the initial criterion for selection was the value of the 20° C viscosity of a 1.0% by weight aqueous solution, as measured by a Brookfield viscometer at a constant shear rate of 10.2 reciprocal seconds (sec l ) .
• a l l v i s c o s ity measurements were made using a conventional Brookfield viscometer, spindle set SC 4-31, from Brookfield Engineering Laboratories, Inc., 240 Cushing Street, Stoughton, MA 02072.
• xanthan thickeners xanthomonas polysaccharide
• xanthomonas campestris xanthomonas Incanae
• xanthomonas Malvacaerum R 2 xanthomonas Malvacaerum R 2
• Aqueous xanthan (xanthomonas hydrophilic colloidal polymer) solutions of preferred embodiments of the present invention have surprising and unexpected rheological properties.
• Their pseudoplastic flow behavior is characterized by a dramatic decrease from a high value (obtained with only minimal quantity of thickener) as the shear rate is increased to a low value.
• the viscosity drop is rapid and yet fully reversible (nearly instantaneously) with no hysteresis.
• the solutions also have rheological yield points (dyne/cm 2 ), indicating a further uniqueness of simultaneously having an Ellis behavior at very low shear rates.
• thixotropic polysaccharides solutions can include carboxy methyl cellulose, starch, alginates and the family of galactomannans derived from seeds which include guar gum, locust bean gum, and casia gum. Also included is the sulfated polysaccharide gum derived from marine algae, carrageenan.
• xanthan gum is a polysaccharide thickener that retains very high and durable pseudoplastic behavior, but is not thixotropic. It has essentially no time-dependent plasticity. Xanthan thickened systems of the present invention thus do not flow or sag with time under the constant shear stress of gravity or steady wind. This is a desirable requirement for aeronautical applications, and for some nautical, civil (e.g. bridges, roads), and domestic (e.g., sidewalks) applications as well, especially on inclined surfaces.
• the selected polysaccharide is: 1. an exocellular hydrophilic heteropolysaccharide
• an exocellular hydrophilic polysaccharide polymer eg. a specific selected xanthan
• a water-dispersible thickener for mono- and polyhydric-based aqueous deicing and anti-icing fluids, especially in the resulting rheological behavior it produces.
• the xanthan' s thickened fluids have a number of attributes, some of which are useful in the present invention, e.g.:
• shear rate dependency of the fluids of the present invention e.g. the rate at which viscosity drops from a very high static value, in a steep smooth and predictable manner, to an asymptotic very low value with increasing rate of shear, and is a highly sought after feature
• the shear rate dependency characteristic of the fluids of the present invention is not damaged by high shear forces, unlike that of the prior art, and thus it displays no hysteresis of viscosity with shear rate T .
• the aqueous freezing point depressant (FPD) anti-icing or deicing fluids thickened by the selected xanthan polymer have inherent high static and low dynamic viscosity values that are less temperature variant than those of the commercially available prior art thickened fluids described herein.
• the art compositions have characteristics which are less of the elastic liquid type and tend more toward the viscous liquid in behavior.
• Additional bacterium progenated heteropolysaccharide hydrophilic colloids produced in-vitro by controlled aerobic fermentation by select bacteria strains and suitable as thickeners for fluids of the present invention include:
• Beijerinekia Indica from bacterium Azotobacer Indicus, in aqueous dispersions are viscosity reversible and pseudoplastic, stable over a wide temperature range and exhibit higher static viscosities (at low concentrations) than even most xanthanes.
• the present anti-icing and/or de-icing fluid is formulated around a type of hydrophilic colloidal polymers, preferably comprising of heteropolysaccharides that are usually manufactured in-vitro by the action of bacterial aerobic fermentation.
• That process results in a simple, one-component thickening agent, e.g. a xanthan, that readily combines with a non-toxic, freezing point depressant aqueous fluid to give continuous phase stable solutions having improved Type II anti-icing fluid behavior and having improved holdover times.
• the aqueous solution provides the desired anti-icing behavior over a practical range of operating temperatures.
• the entire formulation is comprised of food grade constituents, and thus is essentially non-toxic.
• hydrophilic- hydrophobic constituent e.g., (1-n-dodecanol) constituent
• extended holdover times are also achieved, which are in excess of the times characteristic of the current state- of-the-art fluids.
• the hydrophobic upper layer formed constitutes an effective barrier to penetration by ambient precipitation, e.g. freezing rain or drizzle, thereby minimizing dilution or washing away of the protective barrier coating.
• deicing fluids described by Ma, et al., U.S. Patent 4,954,279 and K ⁇ nig-Lumer, et al., U.S. Patent 4,358,389 form gels.
• the solutions of the present invention typically require no oil- based micro-emulsions for fabrication or for storage stability and do not form gels.
• the fluids of the present invention have high static viscosities to provide improved durable icing protection coverage prior to aerodynamic air flow, and which then drop to ensure complete coating removal by airflow during the aircraft's take-off and prior to flight. This viscosity decrease, as the shear rate increases, is substantially instantaneous and is also fully reversible. Further, the fluids of the present invention have excellent thermal stability, and their viscosities are essentially constant over the range of 0° to +80°C.
• xanthan thickeners are synthetically produced (in-vitro) food grade heteropolysaccharides, (for example by the genus of bacterium, xanthomonas) they do not appear to be susceptible to microbial or fungal attack (nor are the polyacrylate polymers), prior to application. However, after spraying and use, they are consumed by these natural agents present in the local environment (unlike the acrylates) to greatly reduce any environmental impact.
• Ma et al. describes using a de-icing composition using ethylene glycol and other alcohols with a xanthan gum as an optional (preferred) thickening agent for anti-icing fluids.
• a water-insoluble mineral oil in micro-emulsion is added to keep the fluid as a homogenous two-phase blended suspension (lyophobic/lyophilic) system, and to prevent gelling or phase separation caused viscosity decrease (either of which renders the fluid useless) from occurring when the composition is stored at sub-zero temperatures for prolonged period of time.
• Ma, et al. discloses at column 5, line 38, et sec,
• the partially polar compounds comprise at least a portion of the oil and are provided in an amount of about 0.1 to 2.5% by weight based on the total composition.
• the partially polar compounds will usually comprise a micro- emulsion of micelles.
• the total oil is an amount up to about 5% by weight based on the total composition and when oils other than partially polar compounds are used, they are prefereably present in amounts of at least about 0.01 % by weight of the total composition.
• the amount of such oil present in the micro-emulsion with the continuous phase components of the composition of this invention should be in the range of from 0.01 % to 5.0% by weight based on the total weight of the composition.
• the present composition does not require the addition of mineral oil as a micro-emulsifier to form tiny micelles since the xanthan gum type that is used goes readily into solution with aqueous anti-icing fluids, using conventional mixing procedures. Also, the present composition is cold-storage stable and has been freezer stored for over three months with weekly testing which confirms that there is no change in desired chemical or physical properties. Unlike the fluids of the Ma et al. patent (without the micro-emulsion of water insoluble oils), the fluids of the present invention show the ability to maintain their original flow characteristics, clarity, or storage ability (thus showing no tendency to .ge_l) even after prolonged cold storage.
• Viscosity versus shear rate rheologial data presented in Figure 25 represents the results of evaluating small portions, each taken from the fluid stored in a freezer in a closed glass container. These samples were warmed slowly to room temperature (around +20°C), also in a closed glass container, and then evaluated for shear rate dependency of viscosity using the same Laboratory Brookfield Viscometer that was used throughout the development work herein. A comparison was made of each sample's characteristic with the original data. No changes were observed throughout the test serves, which lasted for 106 days of cold storage viscosity tests (and continues). (See Figure 25). While not wanting to be bound by theory, the following explanation is presented. Viscosity moduli are generally far more temperature dependent than are elastic moduli.
• the lower variation of viscosity with temperature is a very valuable feature for Type II thickened FPD anti-icing fluids for aircraft reasons, e.g. formulation, storage, shelf- life.
• Low dependence of viscosity with variation of temperature is a very desirable feature for Type II thickened FPD anti-icing fluids for the following reasons: ⁇ Safety-Hold over times and fluid release speeds are less affected by weather-related temperature fluctuations.
• Hydrophobic Thin layer - A hydrophobic very thin layer surface, described herein as essentially a monolayer, is formed on the exterior surface (or surfaces) of the fluid composition applied to the structure to be given ice protection, by the incorporation of component (e), the primary unbranched aliphatic alcohol, such as 1-dodecanol. Presumably, the hydrophilicity of the hydroxy 1 end alighn that end of the molecule towards the aqueous FPD, while the opposite end of the hydrocarbon chain is repulsed to form a hydrophobic layer.
• component (e) the primary unbranched aliphatic alcohol, such as 1-dodecanol.
• the 1-dodecanol as an additional component to the FPD fluid, imparts two very desirable properties. First, it produces a hydrophobic outer layer to enhance the ability of the applied ice protection fluid to resist ambient moisture incursion. This feature produces an extended holdover time for aircraft, and added weather resistance and durability for other uses.
• the hydrophobic layer presumably is achieved by the 1-dodecanol' s having a polar hydroxy 1 end group with a strong, hydrophilic affinity to the aqueous fluid surface, while the aliphatic chain portion is repelled. This type of structure causes a close-knit parallel alignment of the linear molecules to create a paraffin-like facade or exterior layer that limits moisture attraction and incursion.
• 1-Dodecanol while not very soluble in water at room temperature, is readily soluble (to extents suitable for the purposes of this invention) in at least the following: propylene glycol; blends of propylene glycol and water; blends of propylene glycol, xanthan (and other polysaccharide gum thickeners) and water; blends of propylene glycol, xanthan gum, isopropyl alcohol (2-propanol) and water.
• Incorporation of 1-dodecanol to all the various ice protection compositions of this invention indeed has been shown to impart a hydrophobic outer layer which then is better able to resist drizzle or rain droplet incursions. Both clear water and also water dyed to enhance observabilty when applied topically in the form of droplets remained beaded without dissolving into the bulk of the coating.
• 1-dodecanol apparently forms a hydrogen-bonded complex of the hydrated xanthan thickener.
• This property permits the FPD fluid to be foamed to a creamy homogenized fine consistency during application, creating a highly stable and mechanically firm, better clinging (especially to inclined or complex surfaces), durable and a long-lived expanded layer of FPD fluid.
• This foaming of the 1-dodecanol compositions is readily achieved by conventional mechanical agitation with aeration. The foam is capable of being pumped for conventional nozzle spray application with no loss of rheological of FPD properties.
• foaming occurs at the nozzle, which is modified for this purpose.
• foamed versions of the fluid display significantly higher static viscosity than the same fluid has prior to foaming
• the viscosity versus shear rate dependency was found to be identical to that of the fluids of Figures 11 and 12. This result serves to indicate that the shear minning behavior appears to have remained unaffected by the foaming action.
• Resistance to "rain” of the foamed fluids appears to be significantly improved, with the water droplets observed to be beading on the hydrophobic surface.
• the amount of water in the composition according to the present invention is between about 40.0 and 86.0 weight percent of the sum of weights of water and FPD(s), more preferably between about 40.0 and 80.0 weight percent, and especially between about 40.0 and 50.0 weight percent.
• the freezing point depressant is present in the composition in between about 14.0 and 60.0 weight percent of the water and FPD combined weight, more preferably between about 20.0 and 60.0 weight percent, and especially between about 50.0 and 60.0 weight percent.
• the thickener is a food grade xanthan, which is present in the composition in between about 0.01 and 10.0 weight percent, more preferably in between about 0.10 and 5.0 weight percent and especially between about 0.25 and 1.0 weight percent of the total composition.
• the optional monohydric alcohol is a to C straight chain aliphatic primary alcohol, more preferably a to C 16 , straight chain primary aliphatic alcohol, especially a C 10 to 4 , straight chain unbranched primary aliphatic alcohol, and specifically 1-dodecanol.
• the monohydric alcohol is present in between about trace amounts, sufficient to form a thin layer on the exterior surface of the applied compositions, e.g. between about 0.01; and 5.0 weight percent, more preferably between about 0.10 and 5.0 weight percent and especially about 0.75% weight percent.
• water is present in the composition in between about 40.0 and 70.0 weight percent of the sum of the water and FPD weights, more preferably between about 35.0 and 55.0 weight percent, and especially between about 40.0 and 44.5 weight percent.
• the freezing point depressant for aircraft applications is present in between about 40.0 and 60.0 weight percent of the combined FPD and water weight, more preferably between about 45.0 and 60.0 weight percent, and especially between about 50.0 and 60.0 weight percent.
• the thickener as a heteropolysaccharide is preferably a food grade xanthan which is preferably present in between about 0.2 and 1.0 weight percent, more preferably in between about 0.25 and 0.75 weight percent and especially between about 0.45 and 0.55 weight percent of the total composition.
• a monohydric alcohol 1-dodecanol which is preferably present in between about 0.10 and 5.0 weight percent, more preferably between about 0.01 and 3.0 weight percent and especially between about 0.10 and 0.75 weight percent of the total composition.
• compositions of the present invention polymers of acrylates, acrylic acid, methacrylates or methacrylic acid are not present.
• Isopropanol Additive ⁇ The combination of isopropanol as a major portion of the FPD blend with propylene glycol (PG) imparts certain beneficial characteristics. For example: in compositions of 45 wt% isopropanol (IPA) and 10 wt% propylene glycol (PG) and suitably thickened with xanthan, almost identical ice protection and rheological properties (compared to using only PG as the FPD, components using only PG as the FPD, i.e., using 55 wt% PG), are obtained. After application to the surface, the IPA/PG blend has a far less environmental impact on the airport environment. This is because of the IPA higher vapor pressure.
• IPA isopropanol
• PG propylene glycol
• This alcohol evaporates into the atmosphere where it is decomposed by ultra violet/air oxidation to carbon dioxide and water.
• the PG residue locally is reduced to less than one fifth initially, compared to an all glycol FPD fluid.
• the IPA acts as an extender and a uniform distributor of the PG mix.
• the friction enhancing solids comprise beach sand sized small grit, preferrably biodegradable non-toxic or minimally toxic and non-soluble.
• a freezing point depressant (FPD) fluid composition thickened as described herein, and further includes friction enhancing agents(s) that are co-applied or sequentially applied to the surface where it is desired to provide both anti-ice/deice protection and increased friction/traction.
• Such friction enhancing agent(s) are comprised of suitably fine pulverized solid(s) having the following desirable features: (a) the pulverized solid particles are essentially sharp cornered or edged, (b) are not soluble nor significantly softened by the FPD fluid mixture, (c) preferably biodegradable and non-toxic, and (d) non- corrosive in the FPD fluid mixture.
• these solids include, but are not limited to, pulverized organic nut shells, husks, kernels, seeds, bark, and wood fragments, and certain synthetic polymers, and for selected situations, sand. It should be noted that deliberate ingestion of certain nut shell fragments below a particular size is universally used by maintenance facilities to remove incrusted coke and deemed beneficial to jet aircraft engines. Smart Fluids for Use as Anti-Icing Fluids or Deicing Fluids
• a "one-fits-all" Type II deicing fluid has some drawbacks.
• Each size and type of aircraft has a characteristic rotational airspeed that itself is dependent on many internal and external factors, not the least of which include density altitude and loading factors.
• This tailored result is referred to herein as "a smart fluid”.
• a smart fluid With the teachings of the present invention, such a capability now becomes a practical reality.
• Xanthan thickened FPD fluids exhibit useful and desirable pseudoplastic flow (with little or no thixotropic time-dependent plasticity).
• the fluids have a yield value. That initial value of finite shear stress (also known as yield stress) resistance, which must be exceeded to initiate fluid flow, is determined for a given set of conditions such as fluid temperature and thickener concentration.
• the smart fluid is described herein with reference to Figures 16 and 17.
• Figure 16 graphically presents a plot of the square root of apparent viscosity
• Figure 17 is a graph similar to Figure 16, but using data characteristic of different composition of this invention, as shown: 55.0 wt% propylene glycol 0.5 wt% xanthan 44.5 wt% water
• the desired characteristics for a FPD fluid to function as a suitable Type H ice protection fluid include how its viscous and structural integrity properties are optimized to assure that, statically, an effective ice protective blanket covers a surface e.g., an aircraft's critical flight surfaces.
• the structural (i.e. viscosity) integrity to this layer rapidly disintegrates to a low viscosity, easy flowing fluid under the aerodynamic airflow shear just prior to the aircraft attaining its liftoff airspeed.
• the fluid readily flows off the critical exterior surfaces, carrying away any ice that had accreted superficially, so that the aircraft then is essentially clean aerodynamically at or immediately before lift off.
• Figure 20 shows a graphic representation of the rheological behavior of Newtonian fluid and a typical pseudoplastic Type LI anti-ice or deicing fluid (ADF).
• ADF pseudoplastic Type LI anti-ice or deicing fluid
• a composition is formed in-situ whose initial unsheared "static" viscosity corresponds to a pre-specified or required yield value, i.e. the yield value obtained for the composition by the incorporation of a given amount of xanthan, predetermined by a plot of the square root of viscosity versus shear rate (for the intended temperature) to obtain the provide slope.
• the slope squared provides the yield point, which then is correlated to the equivalent aerodynamic shear speed, representing the value where the applied fluid is essentially all shed due to shear thinning.
• the low shear rate (nearly static) viscosity as shown in Figure 13 is very high at 56,500 cPs and rapidly dropping to about 400 cPs at 20.5 reciprocal seconds, already close to limiting high shear viscosity, ⁇ ⁇ , of 169 cPs in Figure 17. From Figure 17, one is able to determine from the slope ( ⁇ 0 ' A ) the yield stress value of 51.6 dyne/cm 2 (0.108 lbf/ft 2 ).
• an anti- icing freezing point depressant fluid composition having rheological properties which are specifically tailored to meet the specific aerodynamic requirements of the surface to be anti-iced.
• This process includes, but is not limited to selecting and producing an anti-icing composition whose rheological properties are specifically tailored to meet the aerodynamic requirements for the surface to be anti-iced, either that the freezing point depressant fluid composition be all removed, i.e. shed, peeled off; or that the fluid must be able to withstand without shedding, for cases such as nautical powerlines, bridges, etc. Since xanthan's overall concentration affects on the fluid viscosity far exceeds the contribution of any other component, the composition determination for aerodynamic tailoring reduces to finding the xanthan concentration by:
• D/S is the drag affect
• p is the density altitude of air
• C D is the aerodynamic drag coefficient
• U is the air velocity
• (c) correlating the yield stress, ⁇ 0 , to the drag affect, using the equation: ⁇ 0 D/S;
• step (g) adjusting the result of step (f) for any temperature corrections necessary by utilizing data from Figure 15;
• composition determinations for aerodynamic tailoring reduces essentially to the determination of the appropriate thickener (e.g., xanthan) concentration.
• One example of blending consists of mixing during aircraft application proper ratios of the same FPD concentrations but with differing thickener concentrations in order that the desired final viscosity is achieved.
• FPD embodiment compositions of this invention especially considering their unusual long-term durability.
• compositions are described herein for use in anti- icing and deicing situations. Another aspect to this invention is that these compositions are useful to provide a coating on a surface to provide a barrier to prevent graffiti (pain, enamel, lacquer, ink, dyes, etc.) from adhering to the surface.
• a polyol e.g., propylene glycol, glycerin, butylene glycol, etc.
• Glycerin is the preferred polyol for solving graffiti problems, usually present in the composition between 10 and 45% by weight, more preferably between about 27 and 35.
• the coating on the surface is essentially transparent, and is very durable.
• the glycerin version is effective as an anti-graffiti coating, even as a thin residual layer. Thus, except for the most sever torrential driving rain, sufficient protection usually remains after exposure to normal rainfall to be effective in providing the desired protection.
• the surface of the coated object e.g. a sign, a concrete wall, a wooden wall, etc.
• graffiti in the form of paint, lacquer, enamel, ink, etc.
• the coating and surface is next contacted with water, (hot or cold) usually under low or moderate pressure. As can been seen in the Figures 26-37, the graffiti is easily and quickly removed. A renewed application of the composition then creates a new coating barrier on the surface to protect against later applied graffiti.
• the xanthan is available from many commercial sources and in a variety of grades.
• the xanthan used in this invention was obtained from the Kelco Division of Merck, Inc. of San Diego, California, grade KELTROL 1 * . It was used directly without further purification.
• the compositions are prepared in a conventional manner. The order of addition or combination is generally not critical.
• a composition was prepared containing 55.0 wt% isopropanol, 44.0 wt% water, 0.75 wt% xanthan, and 0.25 wt% 1-dodecanol. These components were combined, and applied to the windshield of an automobile. This composition formed a protective blanket to prevent subsequent ice accretion and adherence, and render ice on the glass to be soft and easily removed.
• the application of the composition occurs by using a mechanical "spritzer" type hand sprayer.
• other techniques include a pressurized can, or by the windshield washer system which has been suitably modified. Overnight windshield ice protection is possible by spraying prior to overnight ice or frost formation.
• the fluid composition was applied in early evening to portions of the windshield of an automobile parked outdoors under freezing conditions in early March 1994. Upon returning to the automobile at 7:30 the next morning, the surfaces where the fluid composition was applied had no frost. On the other hand, all other external glass surfaces were frozen over with hoar-frost. Clearing the unprotected windshield required time and heat and/or considerable manual scraping. One revolution of the windshield wiper completely cleared the fluid from the windshield surface and the windshield was sufficiently clean and clear for immediate operation of the automobile.
• compositions for Figures 7 and 8 were 52.1 and 45.0 wt% isopropanol; 5.2 and 10.0 wt% propylene glycol; 0.4 and 0.5 wt% xanthan; and 42.3 and 44.5 wt% water; respectively. These components were combined mixed and applied to the surface to remove formed ice or to cause any ice formation to be soft and easily removed.
• 1-Dodecanol is an optional added component included as a means of forming a monolayer and further has the advantage of being transparent and not obscuring vision. The ice was not formed at -40°C.
• the shelf life of the present composition was in excess of 36 months; samples stored in sealed light-tight containers and subsequently evaluated exhibited little or no observed degradation in performance when compared to freshly prepared compositions.
• Example 1(b) or 1(c) are repeated except that the xanthan concentration was 5 percent by weight and the water was 40 percent by weight, similar anti-icing or deicing results were obtained; including no ice formed at -40°C.
• Example 1(b) or 1(c) were repeated except that the xanthan concentration is 0.01 percent by weight and the water is 40 percent by weight, similar anti-icing or deicing results were obtained; including no ice formed at -40°C.
• compositions containing 45.0 wt% isopropanol; 10.0 wt% propylene glycol, 0.1 or 5.0 wt% xanthan, and the remainder being water were prepared.
• the amount of xanthan is dictated by the desired "static" unsheared viscosity as prescribed for the specific application. No ice formed at -40C
• PROPYLENE GLYCOL COMPOSITIONS FOR AIRCRAFT (a) A composition containing 55.0 wt% propylene glycol, water 44.5 wt%, xanthan 0.5 wt%, and 1-dodecanol varying in quantity, from just a trace (sufficient to form an exterior thin coating, essentially a monolayer about 0.01 wt%) or approximately 2 wt%.
• the resultant Type LI layer formed for anti-ice protection ranges in thickness from about 25 x 10 3 mm to approximately 10.0 mm.
• Example 3(a) embodiment was reconstituted, except that the 1-dodecanol concentration in the composition was increased from the trace monolayer amount, 0.01 wt% or 5 wt%, depending on the aircraft application, this enables the forming of a stable, firm, long lived, homogenized foam with the hydrated xanthan thickener, upon application of mechanical agitation and aeration (a process similar to making whipped cream).
• the beneficial results of foaming the Type II fluids of this invention upon application also includes producing a protective "blanket" layer that is far thicker for a given amount (or weight) of fluid applied, and results in a better barrier to ice accretation, than if applied unfoamed.
• aqueous composition containing 55.0 wt% (of the combined glycol and water weight) propylene glycol (as FPD), xanthan of 0.5 wt% or 20 wt% can be prepared. The remainder is water.
• the amount of xanthan is dictated by the required "static" unsheared viscosity as prescribed for those various specific nautical (shipboard) applications (such as above deck mesh traps, rigging, weather decks, etc.) where tenacity, resistance to wind shear and mist dilution are very desirable features.
• an extrapolation of the line maybe used to predict the approximate xanthan concentration necessary to obtain the desired "static" viscosity.
• data from Figures 10, 11, and 13 predict that, while “static" viscosity is significantly increased with increase in the xanthan concentration, the dynamic viscosity drop due to shear rate increase results in about equally low values.
• This embodiment composition further contains 1-dodecanol varying in quantity from a trace (0.01 wt%), (sufficient to form an exterior coating, essentially a monolayer), or 2 wt%. The remainder of the composition is water.
• Example 4(a) or 4(b) composition blending is repeated, except that the 1-dodecanol concentration is increased from the trace monolayer forming amount 0.01 wt% or 5 wt%, depending on the intended nautical application.
• This increase in dodecanol content enables forming a stable, firm, clinging, homogenized foam with the hydrated (i.e. water treated) xanthan thickener.
• the result of forming the foam is an increase both in tenacity and resistance to dilution of the composition.
• ice generally will not form down to about -40°C.
• a composition is proposed containing 45.0 wt% isopropanol (as one FPD), 10 wt% propylene glycol (as a second FPD) based on the combined weight of FPDs and water, and xanthan of 0.5 wt% or 20 wt% and the remainder is water.
• the amount of xanthan is dictated by the required "static" unsheared viscosity as prescribed for those various specific nautical applications (such as mesh traps stored above deck, rigging, weather decks, etc.) where the composition's tenacity, resistance to wind shear and mist dilution are very desirable features.
• Example 5(a) The composition of Example 5(a) which further contains 1-dodecanol of 0.01 wt% (sufficient to form an exterior coating, essentially a monolayer), or 2 wt% . The remainder of the composition is water. For this composition ice will not form down to about -40 °C.
• a composition is proposed containing 45.0 wt% isopropanol (as one FPD), 10 wt% propylene glycol (as a second FPD) based on the combined weight of FPDs and water; and xanthan of 0.5 wt% or 2.0 wt% . The remainder of the composition is water.
• the amount of xanthan is dictated by the required "static" unsheared viscosity as prescribed for those various specific nautical applications (such as above deck mesh traps, rigging, weather decks, etc.) where tenacity, resistance to wind shear and mist dilution are desirable features.
• Example 6(a) which further contains 1-dodecanol of 0.01 wt% or 2 wt% (sufficient to form an exterior coating, essentially a monolayer) to approximately 2 wt% .
• Example 6(b) composition blending is repeated, except that an environmentally benign coloring agent, F.D.&C. food colorings (yellow #5 and blue #1), is included as a means of tracing visually the location and extent of applied fluid coverage.
• F.D.&C. food colorings yellow #5 and blue #1
• Examples 6(a), 6(b) and 6(c), ice generally will not form at down to about -40 °C.
• compositions containing 45.0 wt% isopropanol (as one FPD), 10 wt% propylene glycol (as a second FPD) based on the combined weight of FPDs and water, and xanthan of 0.5 wt% or 5 wt% . The remainder is water.
• the amount of xanthan is dictated by the required "static" unsheared viscosity as prescribed for those various specific nautical applications (such as mesh traps stored above deck, rigging, weather decks, etc.) where the composition's tenacity, resistance to wind shear and mist dilution are very desirable features.
• an extrapolation of the line may be used to predict the approximate xanthan concentration necessary to obtain the desired "static" viscosity.
• data from Figures 10, 11, and 13 confirm that, while "static" viscosity is significantly increased with increase in the xanthan concentration, the dynamic viscosity drop due to shear rate increase results in about equally low values.
• the result indicates a facility in spray application.
• the composition further contains 1-dodecanol varying in quantity from just a trace to approximately 2 wt% (sufficient to form an exterior monolayer). The remainder of the composition is water.
• Example 7(a) or 7(b) composition blending is repeated, except that an environmentally benign coloring agent, F.D.&C. food coloring (yellow #5 and blue #1), is included (0.1 wt%) as a means of tracing visually the location and extent of applied fluid coverage.
• Example 7(a) or 7(b) composition blending is repeated, except that 1-dodecanol concentration is added of 0.01 wt%, or 5 wt%, depending on the application.
• a stable firm, clinging homogenized foam with the hydrated (water treated) xanthan thickener is formed by aeration/mechanical agitation, which increases both the tenacity and resistance to dilution of the composition.
• Example 7(d) composition blending is repeated, except that an environmentally benign coloring agent, F.D.&C. food colorings (yellow #5 and blue #1), is included (0.5 wt%) as a means of tracing visually the location and extent of applied fluid coverage.
• F.D.&C. food colorings yellow #5 and blue #1
• ice does not form at down to about -40°C.
• An anti-icing composition was prepared according to Example 3(a): propylene glycol 54.9 wt. % water 43.7 wt %
• An anti-icing composition was prepared according to Example 3(a): propylene glycol 54.9 wt % water 43.9 wt %
• Keltrol T (xanthan) 0.5 wt %
• compositions are used for coating glass surfaces, automotive windshields, etc.
• a composition was prepared consisting of 30.0% by weight by weight is isopropanol, 25.0% by weight propylene glycol, 0.10% by weight xanthan, 0.20% by weight, 1-dodecanol, and 44.7% by weight water.
• a composition was prepared consisting of 30.0% by weight isopropanol, 15.0% by weight propylene glycol, 10% by weight glycerin, 0.01 % by weight xanthan, 0.20% by weight 1-dodecanol, and 44.7% by weight water.
• a car side window was similarly treated except that the concentration of xanthan and water were changed and the window was placed in a laboratory freezer over night at -40°C. In one application, the xanthan concentration was 0.5% by weight and the water was 39.8% by weight.
• the xanthan concentration was 0.01 % by weight and the water was 44.8% by weight. Similar anti-icing ad de-icing results occured. Further tests yielded results that no ice formed on the treated surface to -40°C.
• a composition was prepared containing 45.0% by weight glycerin, 10.0% by weight isopropanol, and 0.5 to 5% by weight xanthan with the remainder water.
• the amount of xanthan is dictated by the required "static" viscosity as prescribed for those various specific nautical applications (such as mesh traps stored above deck, rigging, weather decks, etc.) where the composition's tenacity, resistance to wind shear and mist dilution are very desirable features. Referring to the experimental graphic data of Figure 14, an extrapolation of the line may be used to predict the approximate xanthan concentration necessary to obtain the desired "static" viscosity.
• the composition contains 1-dodecanol varying in quantity from a trace to approximately 2% by weight (sufficient to form a monolayer of dodecanol on the exterior surface of the coating. The remainder of the composition was water. This composition is also useful in graffiti protection.
• composition blending was repeated using an environmentally benign coloring agent, F.D. & C. food coloring (yellow #5 and blue #1), included (0.1 % by weight) as a means of visually tracing the location and extent of applied fluid coverage.
• F.D. & C. food coloring yellow #5 and blue #1
• included 0.1 % by weight
• composition blending was repeated adding an environmentally benign coloring agent.
• F.D.&C. Food colorings (yellow #5 and blue#l), was included at 0.5% by weight as a means of tracing visually the location and extent of applied fluid coverage.
• ice does not form at down to about -40°C.
• a composition was prepared consisting of 27.5% by being glycerin, 27.5% by weight isopropanol, 2.5% by weight xanthan, and the remainder water.
• the amount of thickener was selected as the near ideal compromise between that dictated by the desired "state" of unsheared viscosity to ensure the composition's protection tenacity, resistance to windshear and mist dilution, and desirable features for ease of application such as the dynamic viscosity drop due to shear to facilitate spray or brush/roller application.
• the composition further contains 1-dodecanol varying in quantity from a trace to approximately 2.0% by weight which is sufficient to form an monolayer on the exterior surface of the applied coating.
• compositions of example 12 ice formation is inhibited from forming onsurfaces to about -40 °C.
• compositions of example 12 applied to reflective roadway sign material, such as the well-known "SCOTCHLITE ® ,” off-angle reflectance of incident light was noticeably enhanced.
• compositions of example 12 applied to roadway signs, and then vigorous wiped to replicate a "seasons" weathering (none visually apparent remaining) sufficient residue of the fluid composition remained to permit easy removal of simulated spray-can graffiti (enamel or laquer) using only low pressure stream of water.
• compositions of this example which contains hygroscopic glycerin, fluid dryout did not occur after 45 days of horizontal exposure to direct (diurnal) summer sun.
• Figure 26 is a photograph of a 3M "SCOTCHLITE ® " coated stop sign in colors of red and white. A portion of the area below the "O" of the word 'STOP' was coated with the composition of Example 12. The thickness of this added coating was about 1 to 10 mil (0.025-0.25 mm). The coating remained at ambient conditions from 48 to 72 hr. The coated sign was then contacted with a layer of commercial black spray which extended beyond the composition coated area can lacquer to simulate graffiti. The lacquer coating dried very quickly in a matter of minutes. The lacquer was further dried for about 24 hr. at ambient conditions.
• Figure 27 is a photograph which shows the effect of contact with low water pressure with the lacquer coating.
• the area where the lacquer is removed is the area originally coated with the composition.
• the lacquer is completely removed from this area.
• the lacquer was not removed from the uncoated areas and remained tenaciously bonded to the surface.
• a similar experiment was performed on a new 3M "SCOTCHLITE ® " surface. The results were essential the same as with the aged surface. See Figure 28.
• This composition is used for imparting long term ice protection for power lines and components; railroad switches; road and highway signs and airport runway signs and lighting; and for other vertical surfaces where long duration protection is desired and it is believed is achieved by the hygroscopic behavior of glycerin, which minimizes the dryout behavior typically observed for glycols.
• a composition was prepared consisting of 35.0% by weight glycerin, 20.0% by weight isopropanol, 2.5% is by weight xanthan, 0.1% by weight water soluble oil and the remainder is water. The composition further contained 0.45% 1- dodecanol by weight of total composition.
• the thickness of the coating on the surface was between about 1 to 10 mils (0.025-0.25 mm).
• Example 12 Similar to the behavior observed in Example 12 compositions, ice formation is inhibited from forming on surfaces by application of Example 13 to about -40 °C.
• Example 12 Similar behavior to Example 12 's performance on roadway sign material and especially the graffiti protection was observed, but this time achieved after over
• Example 13 fluid material was applied to a flat surface section of a grey concrete stepping block.
• the coating between about 5-10 mils (0.125-0.25 mm), was dried for a week.
• the surface coated and uncoated was then contacted "tagged" with graffiti in the form of commercial black lacquer spray can paint.
• the surface area coated with the composition prevented permanent adhesion of the paint, whereas the paint on the uncoated surface penetrated and bonded into the porous block.
• Figure 29 is a photograph of a commercial painted road sign which is first completely coated with a layer (1 to 10 mil) of the composition of Example 13 and dried overnight (16 hr.). The coating is essentially transparent to the eye.
• Figure 30 is a photograph of the coated sign of Figure 29 which has been contacted with commercial black spray can lacquer to simulate graffiti and dried for 24-48 hrs.
• Figure 31 is a photograph of the coated sign of Figure 30 wherein the coating is contacted with low pressure water (garden hose) and with removal of portions of the black lacquer.
• Figure 32 is a photograph of the coated sign of Figure 31 wherein virtually all the black lacquer and the coating is removed using low pressure water within a few minutes. The sign is restored to its original appearance.
• Figure 33 is a photograph of a grey concrete stepping stone. First a portion of the surface is contacted with composition of Example 13 from about mid vertical to near the right edge and dried. The coating is virtually transparent. The coated and uncoated portions are strayed with black spray can lacquer in the form of a capital "Z" (as shown by added outlines) and dried. The surface is contacted with lower pressure water (garden hose) for a few minutes. The portion of the lacquer on the composition coated area is essentially completely removed. The portion of the uncoated area having a layer of lacquer remains. (See Figure 34)
• Figure 35 is a photograph of the sign of Figure 29 which is first coated with a layer of the composition of Example 13 (1-10 mil) (0.025-0.25mm) and dried (at least 24 hrs.). Green commercial spray can enamel was sprayed into the coated sign and dried (24-48 hrs). Next the coated surface is contacted with low pressure water from a pressure can (portable garden sprayer pump can). As can be seen in Figure 36 the usually tenacious enamel is easily removed.
• Figure 37 is a photograph of the resulting cleared formerly coated sign.
• Figure 35 is a photograph of sign of Figure 29 which is first completely coated with the composition of Example 13. Green spray can enamel is sprayed into the coated surface.
• Figure 36 is a photograph of the dried enamel of Figure 35 which is removed using low water pressure.
• Figure 37 is a photograph of the sign of Figure 36 wherever all the dried enamel is completely removed.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Organic Chemistry (AREA)
• Life Sciences & Earth Sciences (AREA)
• Wood Science & Technology (AREA)
• Dispersion Chemistry (AREA)
• Combustion & Propulsion (AREA)
• Materials Applied To Surfaces To Minimize Adherence Of Mist Or Water (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=22313354

Family Applications (1)

Country Status (4)

Cited By (1)

Families Citing this family (12)

Family Cites Families (2)

• 1999
  • 1999-06-29 EP EP99932030A patent/EP1092002A1/de not_active Withdrawn
  • 1999-06-29 AU AU48425/99A patent/AU4842599A/en not_active Abandoned
  • 1999-06-29 CA CA002336111A patent/CA2336111A1/en not_active Abandoned
  • 1999-06-29 WO PCT/US1999/014678 patent/WO2000000568A1/en not_active Ceased

Non-Patent Citations (1)

Also Published As

Similar Documents