ANTI-ICE COATING

Abstract

Anti-ice coating, including: a continuous phase comprising a first material; a plurality of domains comprising a second material, the plurality of domains being dispersed in the continuous phase and being immersible with the continuous phase; wherein one of the first and second materials comprises a fluorine-containing polymer formed from a fluorine-containing precursor having a functionality greater than 2; wherein the other of the first material and the second material comprises a fluorine-free material, wherein the fluorine-free material comprises at least one of a hygroscopic material and a hydrophilic material; wherein at least a portion of the fluorine-free material is bonded to the fluorine-containing polymer having an isocyanate-containing portion; and wherein the fluorine-containing polymer is crosslinked with a crosslinking molecule having at least 4 functional groups comprising a nitrogen-containing moiety, an oxygen-containing moiety, or a combination thereof, wherein: the first material comprises the fluorine-containing polymer; and the second material comprises the fluorine-free material, and further comprising at least one ionic species which is polymerized by the isocyanate-containing portion simultaneously with the fluorine-containing polymer and the fluorine-free material, so that the at least one ionic species lies between the fluorine-containing polymer and the fluorine-free hygroscopic or hydrophilic material, wherein the at least one ionic species is selected from the group consisting of (2,2-bis-(1-(1-methylimidazolium)-methylpropane-1,3-diol bromide), 1,2-bis(2'-hydroxyethyl)imidazolium bromide, (3-hydroxy-2-(hydroxymethyl)-2-methylpropyl)-3-methyl-1H-3λ4-imidazol-1-ium bromide, 2,2-bis(hydroxymethyl)butyric acid, N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid, N-methyl-2,2'-iminodiethanol, 3-dimethylamino-1,2-propanediol, 2,2-bis(hydroxymethyl)propionic acid, 1,4-bis(2-hydroxyethyl)piperazine, 2,6-diaminocaproic acid, N,N-bis(2-hydroxyethyl)glycine, 2-Hydroxypropanoic acid hemipotassium salt, dimethylolpropionic acid, N-methyldiethanolamine, N-ethyldiethanolamine, N-propyldiethanolamine, N-benzyldiethanolamine, Nt-butyldiethanolamine, bis(2-hydroxyethyl)benzylamine and bis(2-hydroxypropyl)aniline.

Description

INTRODUCTION

[0001] The present disclosure relates to coatings for exterior surfaces of vehicles, in particular to anti-icing coatings for exterior sensors and body components of vehicles.

[0002] Modern vehicles, especially semi- and fully autonomous vehicles, are equipped with external sensors that collect information about the vehicle's surroundings. Radar (Radio Detection and Range), Lidar (Light Detection and Range), ultrasound, and cameras represent the majority of external sensors used in the automotive industry. These external sensors are typically mounted on exterior surfaces or in pockets defined in the vehicle's exterior panels. The external surfaces of vehicle sensors and components are made of various materials such as plastics, metals, sensors, glass, and painted surfaces, which are exposed to the vehicle's harsh external operating conditions.

[0003] Road debris such as dirt, dust, solvents (including oils and fuels), as well as water, sleet, ice, and snow under freezing conditions, accumulate on the exterior surfaces of sensors and components. These accumulations not only impair the aesthetics of the sensors and components, but also the performance of these sensors and operating surfaces. Particularly in sub-freezing operating environments, ice, sleet, and snow can accumulate on the exterior surfaces of these sensors and impair the operation of these sensors and moving exterior components such as fuel filler flaps, charging ports, hoods, and trunk lids.

[0004] Anti-deposit coatings have been applied to the exterior surfaces of sensors and vehicle components. However, these anti-deposit coatings have limited effectiveness against ice formation and a limited duration of effectiveness, which can be prematurely shortened by solvents such as oil and fuel that can contaminate the surfaces of the anti-deposit coatings. While these anti-deposit coatings serve their intended purpose, there is still a need for an improved or new coating that has improved anti-icing properties, is solvent-resistant, and can withstand the harsh operating conditions of vehicles.

[0005] EP 4 039 757 A1 and WO 2018 / 140 212 A1 disclose known anti-icing coatings based on microphase-separated materials having a hydrophobic phase and a hydrophilic or hygroscopic phase. SUMMARY

[0006] According to the invention, an anti-icing coating is provided having the features of claim 1. An anti-icing coating according to the invention comprises a continuous phase comprising a first material and a plurality of domains comprising a second material. The plurality of domains are dispersed in the continuous phase and immersible with the continuous phase. One of the first and second materials comprises a fluorine-containing polymer formed from a fluorine-containing precursor having a functionality greater than 2. The other of the first and second materials comprises a fluorine-free, hygroscopic or hydrophilic material. At least a portion of the fluorine-free material is bonded to the fluorine-containing polymer with an isocyanate-containing moiety. The fluorine-containing polymer is crosslinked with a crosslinking molecule having at least 4 functional groups, including a nitrogen-containing moiety,an oxygen-containing portion and a combination thereof, wherein: the first material comprises the fluorine-containing polymer; and the second material comprises the fluorine-free material, and further comprises at least one ionic species which is polymerized by the isocyanate-containing portion simultaneously with the fluorine-containing polymer and the fluorine-free material, such that the at least one ionic species is located between the fluorine-containing polymer and the fluorine-free hygroscopic or hydrophilic material, wherein the at least one ionic species is selected from the group consisting of (2,2-bis-(1-(1-methylimidazolium)-methylpropane-1,3-diol bromide), 1,2-bis(2'-hydroxyethyl)imidazolium bromide, (3-hydroxy-2-(hydroxymethyl)-2-methylpropyl)-3-methyl-1H-3λ4-imidazol-1-ium bromide, 2,2-bis(hydroxymethyl)butyric acid, N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid, N-methyl-2,2'-iminodiethanol, 3-Dimethylamino-1,2-propanediol, 2,2-bis(hydroxymethyl)propionic acid, 1,4-bis(2-hydroxyethyl)piperazine, 2,6-diaminocaproic acid, N,N-bis(2-hydroxyethyl)glycine, 2-hydroxypropanoic acid hemipotassium salt, dimethylolpropionic acid, N-methyldiethanolamine, N-ethyldiethanolamine, N-propyldiethanolamine, N-benzyldiethanolamine, Nt-butyldiethanolamine, bis(2-hydroxyethyl)benzylamine and bis(2-hydroxypropyl)aniline.

[0007] In another aspect of the present disclosure, the fluorine-free material comprises at least one of poly(acrylic acid), poly(ethylene glycol), poly(2-hydroxyethyl methacrylate), poly(vinylimidazole), poly(2-methyl-2-oxazoline), poly(2-ethyl-2-oxazoline), poly(vinylpyrolidone), and modified cellulose polymers comprising at least one of carboxymethylcellulose, a hydroxyethylcellulose, hydroxypropylcellulose, and / or methylcellulose.

[0008] In another aspect of the present disclosure, the fluorine-free material is a poly(ethylene glycol).

[0009] In another aspect of the present disclosure, the fluorine-containing polymer comprises at least one of fluorinated polyol, perfluorocarbon, perfluoropolyether, polyfluoroacrylate, polyfluorosiloxane, polyvinylidene fluoride, polytrifluoroethylene, polytetrafluoroethylene, and copolymers thereof.

[0010] In another aspect of the present disclosure, the fluorine-containing precursor comprises at least one of a hydroxyl and / or amine functional group.

[0011] In another aspect of the present disclosure, the fluorine-containing precursor is a polytetrafluoroethylene having a plurality of pendant hydroxyl groups.

[0012] According to the invention, the at least one ionic species is selected from the group consisting of (2,2-bis-(1-(1-methylimidazolium)-methylpropane-1,3-diol bromide), 1,2-bis(2'-hydroxyethyl)imidazolium bromide, (3-hydroxy-2-(hydroxymethyl)-2-methylpropyl)-3-methyl-1 H-3λ4-imidazol-1-ium bromide, 2,2-bis(hydroxymethyl)butyric acid, N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid, N-methyl-2,2'-iminodiethanol, 3-dimethylamino-1,2-propanediol, 2,2-bis(hydroxymethyl)propionic acid, 1,4-bis(2-hydroxyethyl)piperazine, 2,6-diaminocaproic acid, N,N-bis(2-hydroxyethyl)glycine, 2-Hydroxypropanoic acid hemipotassium salt, dimethylolpropionic acid, N-methyldiethanolamine, N-ethyldiethanolamine, N-propyldiethanolamine, N-benzyldiethanolamine, Nt-butyldiethanolamine, bis(2-hydroxyethyl)benzylamine and bis(2-hydroxypropyl)aniline.

[0013] The anti-icing coating comprises at least one ionic species which is polymerized by the isocyanate-containing portion simultaneously with the fluorine-containing polymer and the fluorine-free material, such that the at least one ionic species is located between the fluorine-containing polymer and the fluorine-free material.

[0014] In another aspect of the present disclosure, the plurality of domains has an average size of greater than or equal to about 100 nm to less than or equal to about 5,000 nm.

[0015] According to several aspects, an anti-ice coated appliqué is disclosed. The appliqué comprises a polymer film having an outer surface and an inner surface opposite the outer surface, a pressure-sensitive adhesive applied to the inner surface, and an anti-ice coating applied to the outer surface. The anti-ice coating comprises a continuous phase comprising a fluorine-containing polymer having a functionality greater than 2, a plurality of domains comprising a fluorine-free material, and a crosslinking molecule having 4 or more functional groups that links a portion of the fluorine-containing polymer to a portion of the fluorine-free material through at least one diisocyanate-containing moiety or a triisocyanate-containing moiety. The plurality of domains is dispersed in the continuous phase and is immiscible with the fluorine-containing polymer.

[0016] In another aspect of the present disclosure, the crosslinking molecule comprises a nitrogen-containing moiety, an oxygen-containing moiety, and a combination thereof.

[0017] In another aspect of the present disclosure, the crosslinking molecule is a pentaerythritol propoxylate.

[0018] In another aspect of the present disclosure, the anti-icing coating further comprises 0.5-5 wt% colloidal silicon dioxide.

[0019] In another aspect of the present disclosure, the anti-icing coating further comprises at least one of an antioxidant and / or a hindered amine stabilizer.

[0020] According to several aspects, an anti-ice coating for a vehicle component is disclosed. The anti-ice coating comprises a continuous phase comprising a fluorine-containing polymer formed from a fluorine-containing precursor having a functionality greater than 2, and a plurality of domains comprising a fluorine-free material. The plurality of domains are dispersed in the continuous phase and immersible with the continuous phase. At least a portion of the fluorine-free material is bonded to the fluorine-containing polymer with an isocyanate-containing moiety. The fluorine-containing polymer is crosslinked with a crosslinking molecule having at least four functional groups comprising a nitrogen-containing moiety, an oxygen-containing moiety, or a combination thereof.

[0021] In another aspect of the present disclosure, the fluorine-containing precursor comprises a fluorinated material having at least one of a hydroxyl group and / or an amine group. The fluorinated material comprises at least one of a fluorinated polyol, perfluorocarbon, perfluoropolyether, polyfluoroacrylate, polyfluorosiloxane, polyvinylidene fluoride, polytrifluoroethylene, and / or polytetrafluoroethylene.

[0022] In another aspect of the present disclosure, the fluorine-free material comprises at least one of poly(acrylic acid), poly(ethylene glycol), poly(2-hydroxyethyl methacrylate), poly(vinylimidazole), poly(2-methyl-2-oxazoline), poly(2-ethyl-2-oxazoline), poly(vinylpyrolidone), and modified cellulosic polymers comprising at least one of carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, and / or methylcellulose.

[0023] In another aspect of the present disclosure, the fluorine-free material is a poly(ethylene glycol).

[0024] In another aspect of the present disclosure, the anti-ice coating is applied to an exterior surface of a vehicle component.

[0025] Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are for purposes of illustration only and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings described herein are for illustrative purposes only and are not intended to limit the scope of the present disclosure in any way. Fig. 1 is a functional diagram of a vehicle equipped with a sensing system according to an exemplary embodiment; Fig. 2 is a schematic diagram illustrating a surface of an article coated with a two-phase anti-icing coating according to the present disclosure, according to an exemplary embodiment; Fig. 3A-3C are confocal laser scanning microscope images of the two-phase anti-icing coating according to an exemplary embodiment; and Fig. 4 is an illustration of an application with the two-phase anti-icing coating according to an exemplary embodiment. DETAILED DESCRIPTION

[0027] The following description is merely exemplary and is not intended to limit the present disclosure, application, or uses. The illustrated embodiments are disclosed with reference to the drawings, wherein like reference numerals designate corresponding parts throughout the various drawings. The figures are not necessarily to scale, and some features may be larger or smaller to show details of particular features. The specific structural and functional details disclosed are not to be interpreted as limiting, but as a representative basis for teaching one skilled in the art to utilize the disclosed concepts.

[0028] As used herein, a module or control module is one or more combinations of one or more processors, associated memory, and other components capable of executing software, firmware, a program, an instruction, a routine, code, or an algorithm to provide the described functions. The processors include, but are not limited to, application-specific integrated circuits (ASICs), electronic circuits, central processing units, microprocessors, and microcontrollers. The associated memory includes, but is not limited to, read-only memory (ROM), random-access memory (RAM), and electrically programmable read-only memory (EPROM). The functions of a control module according to this disclosure may be performed in a distributed control architecture among multiple networked control modules.A control module may include a variety of communication interfaces, including point-to-point or discrete lines, as well as wired or wireless interfaces to other control modules.

[0029] Fig.1 shows a functional diagram of a non-limiting example vehicle 100 equipped with a sensing system 102. The vehicle 100 generally includes a body 104 having front wheels 106A, 106B and rear wheels 108A, 108B. The front wheels 106A, 106B and the rear wheels 108A, 108B are each rotatably disposed near a respective corner of the body 104. The sensing system 102 includes a sensing module 110 in communication with a plurality of external sensors 112A-112E, including, but not limited to, optical laser devices such as radars. B. a LIDAR (Light Detection and Ranging) device 112A that provides a 360-degree view of the vehicle 100, a forward-facing camera 112B, a rear-facing camera 112C, a side-facing camera 112D and a range sensor 112E such as a sonar device.

[0030] One or more of the external sensors 112A-112E may be equipped with localized processing components that process the collected data. The processed data or raw sensor data may be forwarded directly to the sensing module 110 for further processing. The processed data may be forwarded to an advanced driver assistance system (ADAS) module 114 to increase operator awareness, such as by activating a driver alert interface or by enhancing vehicle functions according to the Society of Automotive Engineers (SAE) standard taxonomy of automated driving levels "J3016."

[0031] To ensure optimal sensing of the vehicle's external environment, the sensing surfaces of sensors 112A-112E should be as free of deposits as possible. During wet and icy operating conditions, liquid water may penetrate the mounting surfaces of sensors 112A-112E and the vehicle body 104, wetting the exterior surfaces of sensors 112A-112E. As the liquid water freezes on the sensor surfaces, the ice formation may have undesirable effects on the operating parameters of the sensors. Likewise, water and sleet may penetrate and freeze into movable panels of vehicle 100, such as the fuel filler flap / charge port 114, causing these movable panels to be temporarily inoperable.

[0032] The present disclosure provides a two-phase anti-ice coating that, compared to known anti-deposit coatings, exhibits improved adhesion, improved bonding to the surfaces of exterior sensors and panels, and improved resistance to solvents such as oil and fuel. The present two-phase anti-ice coating, also referred to as the anti-icing coating, contains two chemically distinct materials, including a fluorinated material and a non-fluorinated (fluorine-free) anti-freeze material. The two-phase anti-ice coating inhibits the wetting and freezing of water on the surfaces of sensors and vehicle components to ensure the proper function of these sensors and vehicle components.As used herein, the terms "composition," "chemistry," and "material" are used interchangeably to generally refer to a substance that contains at least the preferred chemical constituents, elements, or compounds, but which may also contain additional elements, compounds, or substances, including trace impurities, unless otherwise specified.

[0033] The controlled phase separation of the two chemically distinct materials allows both materials to come into contact with ice and inhibits wetting with water and the formation of ice on the coated surfaces. The combination of immiscible chemical functions and controlled phase separation of the anti-icing coating is achieved through the use of a fluorinated material precursor, such as a branched fluorinated polyol, capable of creating a highly cross-linked network due to the high proportion of hydroxyl groups found throughout the backbone of the fluorinated polymer and a cross-linking molecule with four (4) or more functional groups.

[0034] The prior art teaches that increased crosslinking reduces the ice-repelling performance of a coating (Kevin Golovin et al., Designing durable icephobic surfaces. Sci. Adv. 2, e1501496(2016). DOI:10.1126 / sciadv.1501496). In contrast, the present anti-ice coating exhibits a highly crosslinked network by distributing the crosslinking along a fluorinated polyol. The highly crosslinked network of the present anti-ice coating does not form crystalline domains, resulting in a hard coating that cannot break up ice deposits. The branched fluorinated polyol and crosslinker molecule with four (4) or more functional groups work synergistically to resist water and stop ice penetration, while also resisting solvents such as oils and fuels commonly found on roadways.The fluorinated polymer phase repels water, while the non-fluorinated solid anti-frost material prevents ice from forming.

[0035] Fig. Figure 2 shows a portion of a coated article 200 with the two-phase anti-icing coating 202, which has a continuous phase 204 and a discrete phase 206. The two-phase anti-icing coating 202 is disposed on a surface 208 of an article 210, thus providing anti-icing and anti-wet properties to the article 210. The discrete phase 206 defines a plurality of domains 212 with an average size of greater than or equal to approximately 100 nm to less than or equal to approximately 5,000 nm. It should be noted that Fig.2 is merely a simplified schematic representation and not to scale, since the plurality of domains 212 may be smaller than those shown and may be distributed not only on the surface but also within / throughout the majority of the continuous phase 204.

[0036] In certain aspects, the plurality of domains 212 are substantially evenly or homogeneously distributed within the continuous phase 204.

[0037] One of the continuous phase 204 and the discrete phase 206 comprises a fluorinated material, also referred to as the first chemistry. The other of the continuous phase 204 and the discrete phase 206 comprises an immiscible, fluorine-free material, also referred to as the immiscible second chemistry. A miscible material, such as a miscible polymeric material, is a material that can be mixed with another dissimilar material at the molecular level, whereas a substantially immiscible material cannot be mixed or dispersed into another dissimilar material, but instead forms distinct phases, layers, intrusions, such as domains, from the main material without additional manipulation or reaction within the matrix.

[0038] The fluorine-containing material is a fluorine-containing polymer material, also called a fluorinated polymer, formed from a fluorine-containing precursor with a functionality greater than 2. The fluorine-containing precursor, also called a fluorinated oligomer, is essentially immiscible with the fluorine-free material. In the highly cross-linked versions, the fluorinated polymer is usually the continuous phase. A functionality greater than 2 means that each individual precursor molecule has, on average, more than 2 functional groups, such as a hydroxyl group or other functional groups, that react to form a cross-linked fluorine-containing polymer network.

[0039] At least a portion of the fluorine-free material is bonded to an isocyanate-containing moiety. "Isocyanate" is the functional group with the formula -N=C=O. For the purposes of this disclosure, SC(=O)-N(H)-R is considered an isocyanate derivative.

[0040] In the non-limiting example in Fig. 2, the fluorinated polymer forms the continuous phase. The fluorinated polymer inhibits wetting and penetration of water, while the immiscible fluorine-free material defines the discrete phase and acts as a solid antifreeze for ice. The fluorinated polymer and the fluorine-free material are held together by multifunctional isocyanates, and the fluorinated polymer is cross-linked with molecules having four or more functional groups. The cross-linking molecule with at least four functional groups includes a nitrogen-containing moiety, an oxygen-containing moiety, and a combination thereof. It should be noted that the fluorinated polymer can be one of the discrete phase and the continuous phase in the biphasic polymer, and the immiscible fluorine-free material can be the other of the discrete phase and the continuous phase.

[0041] Both the continuous phase and the discrete phase are present on the surface in nanometer (nm) sizes. Ice is formed in millimeter (mm) or larger droplets / areas. The continuous and discrete phases of the coating are significantly smaller than the ice, so both the fluorinated polymer and the fluorine-free material act on the ice. The fluorinated polymer prevents wetting with water and also reduces the adhesion of ice to the surface. The fluorine-free material is a fluorine-free hygroscopic material and / or a hydrophilic material. A hygroscopic material is a material capable of absorbing or adsorbing water from its surroundings. A hydrophilic material is a material that has an affinity for water.In one non-limiting exemplary embodiment, the fluorine-free material is poly(ethylene glycol), also known as PEG, which acts as a solid antifreeze. The PEG mixes with the water molecules that come into contact with the surface, preventing them from crystallizing into ice. By inhibiting ice formation, a liquid water layer is maintained at the surface, drastically reducing ice adhesion.

[0042] The fluorinated polymer is a low-surface-energy material that inhibits wetting and adhesion, while the fluorine-free hygroscopic or hydrophilic material breaks the ice contact line along the surface. Low-surface-energy materials are defined as materials with a surface tension or energy of less than or equal to approximately 50 mJ / m 2 have. (I) The low surface energy fluorinated polymer, the first chemistry, is a fluoropolymer with a functionality greater than two (2), such as fluorinated polyols, perfluorocarbons, perfluoropolyethers, polyfluoroacrylates, polyfluorosiloxanes, polyvinylidene fluoride, polytrifluoroethylene, polytetrafluoroethylene, and copolymers of these materials. These fluoropolymers have hydroxyl or amine functional groups. Polytetrafluoroethylene with pendant hydroxyl groups is an exemplary embodiment. (II) The fluorine-free material, the secondary chemistry, is immiscible with the fluoropolymer and is a material such as poly(acrylic acid), poly(ethylene glycol), poly(2-hydroxyethyl methacrylate), poly(vinylimidazole), poly(2-methyl-2-oxazoline), poly(2-ethyl-2-oxazoline), poly(vinylpyrolidone), and modified cellulose polymers, including: carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, and methylcellulose. The secondary chemistry has hydroxyl or amine functional groups. Poly(ethylene glycol) is an exemplary embodiment. (III) An isocyanate is added to covalently link the first and second chemistries. The reactive agent is selected from the group consisting of polyisocyanate, hexamethylene diisocyanate-based monomers, isophorone diisocyanate-based monomers, methylene diphenyl diisocyanate-based monomers, toluene diisocyanate-based monomers, blocked isocyanate monomers, and a combination thereof. (IV) A crosslinking group with a functionality of 4 or more is added with reactive hydroxyl or amine groups. This may include crosslinkers based on pentaerythritol, triglycerol, di(trimethylolpropane), or combinations thereof. Pentaerythritol propoxylate is an exemplary embodiment. (V) An ionic species or an ionic polyol is added. At least one ionic species is selected from the group consisting of (2,2-bis-(1-(1-methylimidazolium)-methylpropane-1,3-diol bromide), 1,2-bis(2'-hydroxyethyl)imidazolium bromide, (3-hydroxy-2-(hydroxymethyl)-2-methylpropyl)-3-methyl-1H-3λ4-imidazol-1-ium bromide, 2,2-bis(hydroxymethyl)butyric acid, N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid, N-methyl-2,2'-iminodiethanol, 3-dimethylamino-1,2-propanediol, 2,2-bis(hydroxymethyl)propionic acid, 1,4-bis(2-hydroxyethyl)piperazine, 2,6-diaminocaproic acid, N,N-bis(2-hydroxyethyl)glycine, 2-Hydroxypropanoic acid hemipotassium salt, dimethylolpropionic acid, N-methyldiethanolamine, N-ethyldiethanolamine, N-propyldiethanolamine, N-benzyldiethanolamine, Nt-butyldiethanolamine, bis(2-hydroxyethyl)benzylamine, bis(2-hydroxypropyl)aniline. 2,2-Bis(hydroxymethyl)propionic acid (DMPA) is an exemplary embodiment.

[0043] The at least one ionic species is polymerized by the isocyanate-containing portion simultaneously with the fluorine-containing polymer and the fluorine-free hygroscopic or hydrophilic material, so that the at least one ionic species lies between the fluorine-containing polymer and the fluorine-free hygroscopic or hydrophilic material. The at least one ionic species does not enter the fluorinated region because it is insoluble in the fluorine-containing polymer.

[0044] The direct addition of stabilizers to polymers can help prevent oxidation, polymer chain scission, and crosslinking reactions caused by UV radiation or high temperatures. Antioxidants can be added to minimize or terminate oxidation caused by UV or heat. Hindered amine stabilizers are effective in resisting light-induced degradation. Phenyl groups can be added in the chain or at the chain ends to increase heat resistance. These materials can also be combined with one or more additional materials such as a particulate filler, a pigment, a dye, a plasticizer, a flame retardant, a smoothing agent, and coupling agents.The particulate fillers may be selected, among others, from the group consisting of silica, alumina, silicates, talc, aluminosilicates, barium sulfate, mica, diatomaceous earth, calcium carbonate, calcium sulfate, carbon, wollastonite, and combinations thereof; and wherein the particulate filler is optionally surface-modified with a compound selected from the group consisting of fatty acids, silanes, alkylsilanes, fluoroalkylsilanes, silicones, alkylphosphonates, alkylphosphonic acids, alkylcarboxylates, alkyldisilazanes, and combinations thereof. Additional additives may be blended to modify the appearance of the coating. Colloidal silica at 0.5-5 weight percent (wt%) may be added to reduce gloss.

[0045] The anti-ice coating can be applied as a solution to the intended surfaces by drop-pouring, spraying, roller coating, and the like. The solvent is allowed to evaporate, forming a coating with self-cleaning and easy-to-clean properties. Various exterior vehicle surfaces can be coated with the two-phase anti-ice coating of the present disclosure to achieve increased ice resistance and cleanability. The coatings can be applied to a variety of surfaces, including a surface made of a material selected from the group consisting of plastic, glass, a painted surface, metal, and a combination thereof.

[0046] Fig.3A-3C are confocal laser scanning microscopy images of the biphasic anti-icing coating with a branched fluorinated polymer in the continuous phase and a poly(ethylene glycol) in the discrete phase. Fig. 3A is shown at a magnification level with a scale bar of 100 µm, Fig. 3B with a scale bar of 25 µm, and Fig. Figure 3C with a scale bar of 5 µm. The biphasic anti-icing coating was impregnated with a fluorescent dye that preferentially penetrates polyethylene glycol regions (domains). The film was then imaged with a confocal laser scanning microscope. The sample was excited with an argon laser, which excites the dye and causes it to fluoresce. The more strongly fluorescent regions, the brighter areas, represent areas rich in polyethylene glycol. Fig.3A-3C confirm discrete regions of the secondary chemical phase separated from the highly fluorinated regions.

[0047] Although vehicle applications are generally discussed, the two-phase anti-ice coating can also be used in other applications, such as other vehicle applications (e.g., motorcycles and RVs), the aerospace industry (e.g., airplanes, helicopters, drones), nautical applications (e.g., ships, jet skis, docks), agricultural equipment, industrial facilities, and the like, including building gutters and anti-ice coatings on sidewalks and pavements.

[0048] A method of treating an article is provided by the present disclosure. The article may comprise an external sensor, such as a LIDAR sensor or an ultrasonic sensor, a glass plate, a plastic component, a painted surface, a metal plate, and equivalents and combinations thereof. The method comprises (a) obtaining a substrate, such as a sensor, a body component, or a plate; (b) optionally, applying an adhesive layer or a primer to a designated surface of the substrate; (c) forming a polymer solution by combining precursors of the first chemistry and the second chemistry and diluting the combined precursors with a solvent to concentrations ranging from 5 to 60 wt. % of the solids including the polymer components and fillers.Typical solvents include MEK, MIBK, xylenes, butyl acetate, and toluene; (d) spraying the polymer solution onto the intended surface of the substrate; and (e) heating to cure the coating or curing at room temperature.

[0049] Possible adhesion promoters include: a. Alkoxysilanes that form chemical groups on a surface that bind to polyols or isocyanates, such as (3-glycidyloxypropyl)trimethoxysilane (GPTMS), (3-aminopropyl)triethoxysilane (APS), (3-aminopropyl)triethoxysilane (APS) with (3,3,3-trifluoropropyl)trimethoxysilane (FPTS) or (3-aminopropyl)triethoxysilane (APS) with trimethoxyphenylsilane (TMPS). b. Epoxy or polyurethane paints with organic primer. c. Adding a third polymer block to the polymer that physiologically adsorbs to specific surfaces. For example, polyurethanes form hydrogen bonds with polyester and nylon surfaces.

[0050] Another method for treating an article is provided by the present disclosure. With reference to Fig. 4, the anti-icing coating can be processed into an appliqué 400. The polymer film 402 includes an inner surface 404 and an outer surface 406 opposite the inner surface 404. The polymer film 402 can comprise non-fluorinated polymers or fluorinated polymers. Fluoropolymer films include Teflon FEP, Teflon PFA, Teflon AF, NEOFLON™ EFEP, or PVDF. The inner surface 404 can be treated for adhesion, i.e., the inner surface 404 is ozone treated, corona treated, chemically etched, or plasma treated. An adhesive layer 408 is applied to the treated inner surface 404. The anti-icing coating 410 of the present disclosure is applied to the outer surface 406 and cured.

[0051] The adhesive layer 408 may be a hot-melt adhesive, a chemically curing adhesive (epoxy-amine), or a pressure-sensitive adhesive. A pressure-sensitive adhesive is defined herein to mean a special category of adhesive material that, in a dry form (e.g., substantially free of solvent and water), is aggressively and permanently tacky at room temperature and adheres firmly to a variety of dissimilar surfaces, including paper, plastic, glass, wood, cement, and metal, upon mere contact, without the need to apply pressure in excess of 20 pounds per square inch. These products do not require activation by water, solvent, or heat to exert a strong adhesive holding force on such materials.They have sufficient cohesive holding power and an elastic nature so that, despite their aggressive stickiness, they can be handled with the fingers and removed from smooth surfaces without leaving any significant residue.

[0052] The pressure-sensitive adhesive may comprise linear or branched, random, or block polymers having one, two, three, or more monomer units. Exemplary pressure-sensitive adhesives may comprise a material selected from the adhesives of acrylic resin, polyurethane, rubber, styrene-butadiene-styrene copolymers, ethylene-vinyl acetate, styrene block copolymers, and combinations thereof, such as styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-ethylene-propylene block copolymer (SEP), styrene-isoprene-styrene block copolymer (SIS), or combinations thereof.

[0053] Comparative Example 1: Example 1 is a two-phase polymer comprising a branched fluorinated polymer, a poly(ethylene glycol) antifreeze phase, a 4,4'-methylenebis(cyclohexyl isocyanate) isocyanate, and a crosslinker having three reactive groups (trimethylolpropane).

[0054] Example 1 (not according to the invention), 4-arm crosslinker: A biphasic polymer comprising a branched fluorinated polymer, a poly(ethylene glycol) antifreeze phase, a 4,4'-methylenebis(cyclohexyl isocyanate) isocyanate, and a crosslinker with four reactive groups (pentaerythritol propoxylate). For preparation, a container was charged with Zeffle GK-570 (3.08 g), poly(ethylene glycol) (0.99 g), pentaerythritol propoxylate (0.96 g), and 2-butanone (7.79 g). The solution was mixed until homogeneous. 4,4'-methylenebis(cyclohexyl isocyanate) (2.77 g) and dibutyltin dilaurate (6.3 µL) were added and mixed until homogeneous. The resulting solution was used for spray application.

[0055] Example 2, 4-Arm Crosslinker and Addition of Charged Species: A biphasic polymer comprising a branched fluorinated polymer, a poly(ethylene glycol) antifreeze phase, a 4,4'-methylenebis(cyclohexyl isocyanate) isocyanate, a crosslinker with four reactive groups (pentaerythritol propoxylate), and ionic species (DMPA). To prepare, a container was loaded with Zeffle GK-570 (3.08 g), poly(ethylene glycol) (0.99 g), pentaerythritol propoxylate (0.96 g), DMPA (0.03 g), trimethylamine (0.02 g), and 2-butanone (7.90 g). The solution was mixed until homogeneous and all solids were dissolved. 4,4'-Methylenebis(cyclohexyl isocyanate) (2.83 g) and dibutyltin dilaurate (3.7 µL) were added and mixed until homogeneous. The resulting solution was used for spray application.

[0056] The solvent resistance of the polymers was compared to understand if complete curing had occurred and if the coatings would be solvent-resistant throughout their lifetime. A solvent resistance testing procedure was used that involves curing a coating, wiping it with a solvent-soaked tissue, and inspecting the coating for scratches or solvent damage. Coatings are rated on a scale of 0 to 5, with 0 representing no change and 5 representing complete removal. Methyl ethyl ketone (MEK) was used as the solvent for the liquid formulation of this coating. The ratings are listed in Table 1. The addition of the crosslinker with four reactive groups eliminated solvent damage. Table 1. Resistance to solvent damage sample Evaluation of the observation Example 1 1 (Minor: Barely noticeable cloudiness) Example 2 0 (no change) Comparative Example 1 3 (Moderate: Noticeable cloudiness, stickiness)

[0057] Example 1, Example 2, and Comparative Example 1 were applied to ultrasonic support sensors. The sensors were masked using a combination of painter's tape and Parafilm to limit the coating application to the sensor cylinder. A silane solution was prepared from 2% (3-glycidoxypropyl)trimethoxysilane (GPTMS) in 95% ethanol and 5% water. This silane solution was sprayed onto the sensor at a thickness of approximately 0.5 mil (wet) and allowed to dry. An aerospace primer (PRC-DeSoto CA7502) was then sprayed according to the manufacturer's instructions. The example coatings were sprayed onto the respective sensor cylinders in three separate coats. The masking was removed, and the sensors were cured in an oven at 65°C for 4 hours. The resulting coatings were approximately 1.5 mil thick after drying.

[0058] The sensors were installed in a vehicle. The vehicle was placed in a cold chamber, the temperature was reduced to -10°C, water was sprayed onto a sensor, and the sensor was tested for functionality. The water spraying and sensor functionality testing were repeated until the sensor failed. The process of spraying the sensor with water and then testing the sensor functionality counts as one cycle. The number of cycles until sensor failure was counted and is listed in Table 2. An uncoated sensor was used as a control. Multiple numbers mean that the sensor was retested after thawing. As shown in Table 2, Examples 1 and 2 best withstood sensor immobilization by freezing water. Table 2. Cycles until sensor failure. sample Freeze cycles before failure . Control - uncoated sensor 5, 2, 7 Example 1 12, 11 Example 2 11,11 Comparative Example 1 5, 2,11

[0059] The description of the present disclosure is merely exemplary, and variations that do not depart from the general spirit of the disclosure are to be considered within the scope of the present disclosure. Such variations should not be construed as a departure from the spirit and scope of the present disclosure.

Claims

[1] Anti-ice coating comprising: a continuous phase comprising a first material; a plurality of domains comprising a second material, the plurality of domains being dispersed in the continuous phase and being immersible with the continuous phase; wherein one of the first and second materials comprises a fluorine-containing polymer formed from a fluorine-containing precursor having a functionality greater than 2; wherein the other of the first material and the second material comprises a fluorine-free material, wherein the fluorine-free material comprises at least one of a hygroscopic material and a hydrophilic material; wherein at least a portion of the fluorine-free material is bonded to the fluorine-containing polymer having an isocyanate-containing portion; and wherein the fluorine-containing polymer is crosslinked with a crosslinking molecule having at least 4 functional groups comprising a nitrogen-containing moiety, an oxygen-containing moiety, or a combination thereof, wherein: the first material comprises the fluorine-containing polymer; and the second material comprises the fluorine-free material, and further comprising at least one ionic species which is polymerized by the isocyanate-containing portion simultaneously with the fluorine-containing polymer and the fluorine-free material, so that the at least one ionic species lies between the fluorine-containing polymer and the fluorine-free hygroscopic or hydrophilic material, wherein the at least one ionic species is selected from the group consisting of (2,2-bis-(1-(1-methylimidazolium)-methylpropane-1,3-diol bromide), 1,2-bis(2'-hydroxyethyl)imidazolium bromide, (3-hydroxy-2-(hydroxymethyl)-2-methylpropyl)-3-methyl-1H-3λ4-imidazol-1-ium bromide, 2,2-bis(hydroxymethyl)butyric acid, N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid, N-methyl-2,2'-iminodiethanol, 3-dimethylamino-1,2-propanediol, 2,2-bis(hydroxymethyl)propionic acid, 1,4-bis(2-hydroxyethyl)piperazine, 2,6-diaminocaproic acid, N,N-bis(2-hydroxyethyl)glycine, 2-Hydroxypropanoic acid hemipotassium salt, dimethylolpropionic acid, N-methyldiethanolamine, N-ethyldiethanolamine, N-propyldiethanolamine, N-benzyldiethanolamine, Nt-butyldiethanolamine, bis(2-hydroxyethyl)benzylamine and bis(2-hydroxypropyl)aniline. [2] The anti-icing coating according to claim 1, wherein the fluorine-free material comprises at least one of poly(acrylic acid), poly(ethylene glycol), poly(2-hydroxyethyl methacrylate), poly(vinylimidazole), poly(2-methyl-2-oxazoline), poly(2-ethyl-2-oxazoline), poly(vinylpyrolidone), and modified cellulose polymers comprising at least one of carboxymethylcellulose, a hydroxyethylcellulose, a hydroxypropylcellulose, and / or a methylcellulose. [3] The anti-icing coating according to claim 1, wherein the fluorine-free material is a poly(ethylene glycol). [4] The anti-icing coating according to claim 1, wherein the fluorine-containing polymer comprises at least one of fluorinated polyol, perfluorocarbon, perfluoropolyether, polyfluoroacrylate, polyfluorosiloxane, polyvinylidene fluoride, polytrifluoroethylene, polytetrafluoroethylene and copolymers thereof. [5] The anti-icing coating according to claim 1, wherein the fluorine-containing precursor comprises at least one of a hydroxyl or amine functional group. [6] The anti-icing coating of claim 1, wherein the fluorine-containing precursor is a polytetrafluoroethylene having a plurality of pendant hydroxyl groups. [7] The anti-icing coating of claim 1, wherein the plurality of domains have an average size of greater than or equal to about 100 nm to less than or equal to about 5,000 nm.

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