WO2019008589A1 - Micro-nano patterned anti-abrasive polymeric coatings and a method of production thereof - Google Patents

Abstract

A composition made of a polymeric substrate having deposited on at least one surface thereof a cross-linked polymeric coating layer, with the coating layer being characterized by: (i) nanosized or microsized surface pattern; (ii) pencil hardness of 2H to 9H; and (iii) water contact angle in a range of: 130° to 170°, or 10° to 50° is disclosed. Processes of making the composition are further disclosed herein.

Description

MICRO-NANO PATTERNED ANTI-ABRASIVE POLYMERIC COATINGS AND A METHOD OF PRODUCTION THEREOF

[001] This application claims the benefit of priority from U.S. Provisional Patent Application No. 62/528,583, filed on July 5, 2017. The content of the above document is incorporated by reference in its entirety as if fully set forth herein

FIELD OF THE INVENTION

[002] This invention, inter alia, relates to micrometric and/or nanometric patterned anti-abrasive coatings a method of their production.

BACKGROUND OF THE INVENTION

[003] Patterned surfaces are known to enhance surface properties such as (but not limited to) hydrophobicity (water repulsion) and hydrophilicity (water attraction). It has been shown that for an already chemically hydrophobic surface, roughness may increase hydrophobicity ("Wenzel equation"). The finer the roughness the better, to a point that micro-nano textured hydrophobic surfaces may become super-hydrophobic i.e. repel water totally, this phenomenon is popularly known as the "Lotus Effect".

[004] On the other hand, already chemically hydrophilic surfaces may become more hydrophilic when roughened and super-hydrophilic when micro-nano textured. Both super-hydrophobic and super-hydrophilic surfaces can be used for (but not limited to) self-cleaning or easy-cleaning, anti-icing, anti-fouling, anti-graffiti, anti-fogging and anti-dripping applications.

[005] The advantages of these surfaces are obvious, for example: reducing maintenance costs, prevention of snow and ice build-up in aircrafts, protection from environmental pollution, improving and protecting greenhouse crops and in transparent materials, maintaining the transparency in any conditions and for long time. Transparent polymer surfaces of the kind can be used as skylights, windows, walls, light openings, car glazing, car wrapping, solar collectors, greenhouses, optical lenses, electronic screens, cellular devices screens, etc. Opaque products can be used for internal walling of bathrooms, medical rooms, aviation external parts, easy to clean cars, etc. Medical devices require hydrophobic or hydrophilic properties as well. The range of practical applications is endless.

[006] Reducing the size of the pattern is not only necessary to enhance the specific property, but also to maintain the surface transparent if needed. Amorphous polymers such as (but not limited to) poly methyl methacrylate (PMMA), polycarbonate (PC), styrene acrylonitrile (SAN), polyethylene terephthalate (PET) and polystyrene (PS) are highly transparent. Transparency and surface roughness are usually contradictory properties. A macroscopic patterned surface on these polymers disturbs and scatters the passage of light increasing the haze, reducing light transmission and distorting the see- through property. If the surface pattern is reduced in size, the light scattering is reduced. The smaller the pattern scale, the better. When the pattern scale approaches the light wavelength, the haze is reduced, the surface becomes increasingly transparent and see- through can be maintained. In such a way, a micro-nano textured surface will render the unique properties of the surface while maintaining the light transmission and the see-through properties of the original polymer.

[007] Finally, the anti-abrasive nature of the cured coating provides durability and significantly increases the lifetime of the surface and its properties. Patterned Super- hydrophobic, super-hydrophilic anti-icing, antifouling, anti-fogging and anti-dripping surfaces have been attempted and achieved in various ways, also in polymer surfaces. However, all the technologies for producing this type of polymer surfaces face a common problem, namely lack of durability.

[008] This drawback is the main barrier to industrial and commercial implementation of these technologies. For example, the most super-hydrophobic technologies developed until today are based on the "Lotus Effect". The lotus is a symbol of purity in Asian cultures. It grows in muddy waters, however it keeps clean and fresh without being harmed by dirt, pollution and living organisms. The leaf of the lotus is hydrophobic and micro-nano-rough i.e. super-hydrophobic.

[009] The super-hydrophobicity creates a high contact angle of water with the solid surface, reaching above 150° and the micro-nano roughness reduces the area of contact leading to lower adhesion of water and dirt particles. Water drops roll easily on the leaf surface picking up dirt particles with them. This mechanism is known as self-cleaning lotus effect. However, at the same time fine roughness causes a durability problem common for all super-hydrophobic, or generally speaking, all micro-nanoscopic textured surfaces. The smaller the scale of the texture, the better the property. On the other hand, the finer the texture, the lower the mechanical stability of the surface texture. The lotus leaf can cope with this problem because as a living organism it can grow and self-heal. This problem is even more critical for polymers since they have relatively soft surfaces as compared to metals and ceramics.

[010] Current lotus effect developments and technologies for polymer surfaces are typically sensitive/weak to abrasion stresses, with low durability and short life-time, which makes them not suitable for most practical applications.

[011] Polymer materials are relatively soft materials. Under outdoor conditions of rain, UV radiation, snow and wind, they will be scratched, abraded and degraded. In order to improve the abrasion resistance of polymers they are coated with surface abrasion resistant coatings. Commercial transparent abrasion resistant coatings are available for polymers such as PMMA, PC, SAN, PET and PS . These coatings are based on thermosetting polysiloxanes, polyurethanes, silicones, and acrylates with and without functional additives that can cure and harden on the soft polymer surface creating a hard "glass like" transparent abrasion resistant micronic layer. The abrasion resistant coating of polymers significantly increases the life expectancy of the polymer product. Commercial abrasion coatings formulations include UV absorbers that protect the coating and the polymer under the coating from the harmful effects of outdoor or indoor UV radiation: sun or artificial light, increasing even further the durability of the coated product.

[012] The problem of the low durability of the micro-nano patterned surfaces on polymers is considerably reduced by this invention, via creating a micro/nano -pattern, not on the surface of the polymer itself, but on the abrasion coating that protects it, thus increasing the life time of the property to the maximum possible for a polymer.

[013] Commercial anti-abrasive and/or anti-scratch transparent coatings for polymers such as PMMA, PC, SAN, PET and PS are available in two types: thermally cured and ultra-violet (UV) cured. Since the UV-curing chemistry is more limited, the range of thermal cured coatings is broader, however, UV-cured coatings have a significant advantage over the thermal cured ones. While thermal curing takes hours, UV-curing takes minutes or less. This is not only a significant cost advantage in terms of production time, but also allows for the on-line application of the UV-coating, meaning that the coating can be applied and cured at the same production line and time as the product itself (e.g. an extruded polymer sheet or film). SUMMARY OF THE INVENTION

[014] This invention, inter alia, relates to micrometric and/or nanometric patterned anti-abrasive coatings a method of their production.

[015] According to an aspect of the present invention, there is provided a composition comprising a polymeric substrate having deposited on at least one surface thereof a cross-linked polymeric coating layer, wherein the coating layer is characterized by:

(i) nanosized or microsized surface pattern;

(ii) pencil hardness of 2H to 9H; and

(iii) water contact angle in a range of: 130° to 170°, or 10° to 50°.

[016] In some embodiments, the coating layer is further characterized by visible light transparency in a range of 70 to 95% in accordance to ASTM D1746.

[017] In some embodiments, the coating layer comprises one or more ultraviolet (UV)-absorbent additives.

[018] In some embodiments, the coating is characterized by water contact angle of at least 150°.

[019] In some embodiments, the coating is characterized by water contact angle of less than 50°.

[020] In some embodiments, the coating layer is covalently attached to the polymeric substrate.

[021] In some embodiments, the coating layer is in the form of a textured pattern comprising an array of pillars.

[022] In some embodiments, the coating layer is in the form of a textured pattern comprising an array of cones.

[023] In some embodiments, the coating layer is in the form of a textured pattern comprising an array of holes.

[024] In some embodiments, the array have pillars, cones or holes with a median height/depth of about 2 to about 20 micrometers.

[025] In some embodiments, the array have pillars, cones or holes having one or more dimensions selected from length or width or diameter, characterized by about 0.5 to about 5 micrometers.

[026] In some embodiments, the textured pattern comprises pillars, cones or holes having a median space therebetween of 1 to 20 micrometers.

[027] In some embodiments, the pillars, cones or holes are round-, band-, sleeve-, elliptical-, square-, rectangular-, triangle-, or star-shaped. [028] In some embodiments, the array of pillars, cones or holes covers from about 0.5% to about 95%, of the total area of the at least one surface.

[029] In some embodiments, the composition is characterized by delta E color shift of no greater than 1.5, as tested according to ASTM G155 after 2000 hours.

[030] In some embodiments, the composition is characterized by Yellowness index of less than 5 according to ASTM E313 after 2000 hours according to ASTM G155.

[031] In some embodiments, the coating has attached thereto one or more hydrophobic groups or agents.

[032] In some embodiments, the coating has attached thereto one or more hydrophilic groups or agents.

[033] According to another aspect there is provided a process for producing the composition disclosed herein, the process comprising the steps of: (i) providing a polymeric mold; (ii) casting a UV transmitting desired material onto the polymer mold in a liquid form and curing the material, thereby creating a template; (iii) Coating the polymer sheet or film substrate with a liquid anti-abrasive coating; and (iv) cross- linking of the coating material through the UV-transmitting template.

[034] In some embodiments, the process further comprises, prior to step (i), the steps of: (a) producing a micro- to nano- patterned maser; and (b) producing a replica of the master.

[035] In some embodiments, the process further comprises, prior to step (iii), the step of cleaning the surface of the polymer.

[036] In some embodiments, the process further comprises the step of applying a coating on a polymeric substrate.

[037] In some embodiments, the polymeric substrate is in the form of a sheet or film.

[038] In some embodiments, the process further comprises a step of applying a UV- transmitting template onto the coating layer.

[039] In some embodiments, the process further comprises a step of cross-linking the coating material, optionally through the template.

[040] In some embodiments, the process further comprises a step of cooling the coating layer to a temperature of below 40 °C.

[041] In some embodiments, the process further comprises a step of peeling the template.

[042] In some embodiments, the process further comprises a step of adding or attaching a hydrophobic agent to the coating layer. [043] In some embodiments, the process further comprises a step of adding or attaching a hydrophobic agent to the coating layer.

[044] In some embodiments, the replica comprises a polymer.

[045] In some embodiments, the polymer comprises polydimethyl siloxane (PDMS).

[046] In some embodiments, the UV-transmitting material comprises a material having an epoxy group.

[047] In some embodiments, the coating comprises thermosetting polysiloxanes, polyurethanes, silicones, and acrylates with and without functional additives.

[048] In some embodiments, the coating comprises l-methoxy-2-propanol, trimethylol propane triacrylate, pentaerythritol tetraacrylate, hexamethylene diacrylate, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, pentaerythritol triacrylate, 2- methoxypropanol, or any combination thereof. The process of claim 19, wherein the coating is characterized by a dynamic viscosity of 1 to 100 cP.

[049] In some embodiments, the process further comprises a step of adding a UV- absorbent additive to the coating layer.

[050] In some embodiments, the UV-transmitting template is a UV-transmitting roll- band-sleeve micro-textured surface.

[051] In some embodiments, the coating can be applied from both sides or surfaces of a polymer.

[052] In some embodiments, the process is a batch process, semi-continuous e.g., step-and-repeat, or continuous process.

[053] In some embodiments, the coating is applied at the same production line and time of the polymer product.

[054] Unless otherwise defined, all technical and/or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the invention, exemplary methods and/or materials are described below. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and are not intended to be necessarily limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

[055] Figure 1 shows a micro-patterned silicon (Si) master produced by photolithography and ion-etching method. This is done on 2" (50.8 mm) diameter [100] -oriented Silicon wafer with 100 nm S1O2 layer. Sample was patterned with 1818 photoresist by GCA Autostep 200 DSW i-line Wafer Stepper UV exposure followed by tetra-methyl ammonium hydroxide (TMAH) aqueous alkaline development. The pattern is transferred onto the silicon dioxide layer, used as a hard mask, by CF₄/0₂ reactive ion etching (RIE) in a 790 PlasmaTherm tool. The subsequent etching of Silicon pillars to the depth of 10 μιη is carried out in a PlasmaTherm Versaline inductively coupled plasma (ICP) system by a deep reactive ion etching (DRIE) process. The etching process is terminated with C₄F₈ plasma (which is known to deposit a thin Teflon-like layer) in order to induce hydrophobic properties to the etched Silicon surface, followed by removal of residual photoresist in commercial solvent solution. Upper left panel: a photographic image showing the fabrication step of photolithography and ion-etching technique; Upper right panel: high resolution scanning electron microscopic (HR-SEM) image showing a top view of the pattern; Lower left panel: HR-SEM image showing a top view of the pattern, tilt 7°; Lower left panel: HR-SEM image showing the dimension of the pattern.

[056] Figure 2 shows a double-replication process to produce a micro-nano patterned UV-cured UV-transmitting template produced from epoxy. (1) The initial Si master is covered by polydimethyl siloxane (PDMS, Dow-Sylgard 184), vacuum treated for 1 h and cured at 80°C for 3 h. (2, 3) This forms a PDMS mold which can be easily removed from the Si master. (4) A curable UV-transmitting epoxy OG-178 (Epoxy Technology) is poured over the PDMS mold and UV-cured until reaching full curing. (5) Following full curing, the micro-nano patterned UV-transmitting epoxy replica is peeled off from the PDMS. This UV-transmitting cured replica will be used as a template to impress the micro-nano pattern onto the coated polymer surface.

[057] Figure 3 shows a micro-patterned elastomeric mold produced from PDMS (upper left panel) and a micro-patterned UV-transmitting template produced from epoxy OG-178 (upper right panel) fabricated following the process described in Figure 2; Lower left panel: HR-SEM image showing a top view of the epoxy pattern, tilt 7°; Lower left panel: HR-SEM image showing the dimension of the epoxy pattern.

[058] Figure 4 shows a photographic image of Poly(methyl methacrylate) (PMMA) sheet being coated with a UV-curing anti-abrasive coating by a roll coating method as described herein.

[059] Figure 5 shows an exemplary photographic image of micro-patterned epoxy template applied onto the UV-curing anti-abrasive coating as described herein. [060] Figure 6 shows exemplary photographic images of the anti-abrasive coating (with right panel presenting a closer look) being UV-cured through a micro-patterned epoxy template as described herein.

[061] Figure 7 shows exemplary photographic images of the polymer surface after the micro-patterned epoxy template has been peeled off, as described herein (left panel- UV transmitting template, right panel- the pillar shaped micro-nano abrasive PMMA coating).

[062] Figures 8-10 show HR-SEM micrographs of the resultant micro pattern on the polymer coating surface. Figure 8 demonstrates a HR-SEM top view image of the resulted polymer coating taken via In-Lens detector. Figure 9 shows a high magnification HR-SEM top view image of the resulted polymer coating taken via In- Lens detector. Figure 10 demonstrates a HR-SEM image of the resulted polymer coating obtained with a tilt of 7 deg. As can be estimated from the image the actual depth of the fabricated features on the surface of the polymer coating is around 6 μιη.

[063] Figure 11 demonstrates static contact angle measurements on the micro- patterned polymer anti-abrasive coating produced using the method describe herein and after treatment with fluorosilanes. Contact angle formed by a sessile water drop exceeds 150 deg revealing a super-hydrophobic surface.

[064] Figure 12 demonstrates a non-limiting exemplary schematics of the coating process when a UV-transmitting template is introduced as micro-nano textured roll/glass sleeve which continuously patterns the coating and contains within a UV radiation source. This process is also applied on-line i.e. at the same production line and time as the polymer product (sheet, film) itself; " 1"- substrate, "2"- coating, "3"- textured x-linked surface, "4"- UV source, "5"- transparent, micro/nano- textured roll.

DETAILED EMBODIMENTS OF THE INVENTION

[065] Micro to nanometric sized patterned anti-abrasive and/or anti-scratch coatings can be used to render highly durable surfaces on opaque or transparent polymers with special properties such as super-hydrophobicity and super-hydrophilicity for self- cleaning, easy-cleaning, anti-fouling, anti-icing, anti-fogging or anti-dripping applications.

[066] Currently known methodologies of preparing transparent and/or durable superhydrophopic on a plastic surfaces is a difficult task to achieve. [067] The problem of the low durability of the micro-nano patterned surfaces on polymers may considerably be reduced by the current disclosure, e.g., via creating a micro- or nano-pattern, not on the surface of the polymer itself, but on the abrasion coating that protects it, thus increasing the life time of the property to the maximum possible for a polymer.

[068] While conceiving the present invention, the present inventors have considered employing novel production routes for providing the desired surfaces.

[069] In one embodiment, the invention provides a micrometric and/or nanometric patterned anti-abrasive transparent and/or non-transparent coating on polymers surfaces. The micrometric and/or nanometric patterned anti-abrasive coatings may be used to render highly durable surfaces on opaque or transparent polymers with special properties such as super-hydrophobicity and super-hydrophilicity for self-cleaning, easy-clean, anti-fouling, anti-icing, anti-fogging or anti-dripping applications.

[070] The Composition

[071] According to an aspect of some embodiments of the present invention, there is provided a composition comprising a polymeric substrate (also referred to as "core" or "core material") , having deposited on at least one surface thereof an anti-abrasive (e.g., resistance to mechanical damage) and/or anti-scratch, hard coating.

[072] In some embodiments, by "at least one surface" it is meant to refer to one surface. In some embodiments, by "at least one surface" it is meant to refer to two surfaces, e.g., two opposite surfaces.

[073] Hereinthroughout, the expression "substrate having or deposited on a surface or a portion thereof" is also referred to herein, for simplicity, as a coated substrate, a coated surface, a coated sample, a substrate or surface having a film deposited thereon, and as varying combination of the above expressions, and all of these expressions are referred to herein interchangeably.

[074] Herein, the term "coating" and any grammatical derivative thereof, is defined as a coating that (i) is positioned above the substrate, (ii) is not necessarily in contact with the substrate/coating, that is to say one or more intermediate coatings may be arranged between the substrate and the coating in question (however, it may be in contact with the substrate), and (iii) does not necessarily completely cover the substrate.

[075] The coating may be in the form of a flat or tubular structure e.g., a sheet having substantially greater area than thickness. [076] By "a portion" it is meant to refer to, for example, a surface or a portion thereof, and/or a body or a portion thereof.

[077] In some embodiments, the coating layer is physically adhered to the substrate.

[078] In some embodiments, the coating layer is adhered to the substrate via a covalent bonds.

[079] In some embodiments, the coating is characterized by super-hydrophobicity.

[080] In some embodiments, the coating is characterized by super-hydrophillity.

[081] In some embodiments, the coating is characterized by high transparency.

[082] In some embodiments, the coating is characterized by one or more from: super- hydrophobicity, and high transparency. In some embodiments, the coating is characterized by super-hydrophobicity.

[083] The term "transparency" refers to the clarity of a plastic. Transparency can be measured light transmission by a spectrophotometer, or by any method known in the art.

[084] In some embodiments, by "high transparency" it is meant to refer to light transmission of at least 70%, at least 80%, or at least 90% of the light (e.g., visible light). In some embodiments, by "high transparency" it is meant to refer to light transmission of 70% to 95% of the light (e.g., visible light), as determined by methods known in the art, e.g., according to ASTM D1746 or similar methods.

[085] In some embodiments, the composition exhibits transparency and structural integrity.

[086] The term "structural integrity," as used herein, refers to an article that does not exhibit any visible cracks.

[087] In some embodiments, the coating is characterized by having one or more properties selected from, without being limited thereto, self-cleaning, easy-cleaning, anti-fouling, anti-icing, anti-fogging or anti-dripping.

[088] In some embodiments, the term "anti-fogging" or any grammatical derivative thereof, refers to a property of reducing or prevent water from condensing on a film in the form of water droplets.

[089] In some embodiments, the term "self-cleaning" means the property of a surface that generally keeps the surface clean without mechanical force or detergent to loosen and remove visual detractants.

[090] In some embodiments, the term "anti-icing" refers to preventing ice from forming at the surface or selected areas thereof. [091] In some embodiments, the coating layer (also referred to as: "coating", "layer", interchangeably) is in the form of a cross-linked polymeric structure. In some embodiments, the cross-linking is obtained via UV curing of a curable material being in a liquid form prior to the curing step.

[092] In some embodiments, the curable material comprises an epoxy group.

[093] In some embodiments, the coating comprises thermosetting polysiloxanes, polyurethanes, silicones, and acrylates with and without functional additives.

[094] As used herein, the term "coating", or any grammatical derivative thereof, refers to a separate and distinct layer of material from an underlying material a material. The coating may form a substantially continuous layer on a substrate (e.g., the polymer).

[095] In some embodiment, at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, 99%, or 99.5% of the substrate is coated by the coating layer.

[096] In some embodiments, the coating has a thickness of at least 500 nm, at least 600 nm, at least 700 nm, at least 800 nm, at least 900 nm, or at least 1 μηι.

[097] In some embodiments, the coating has a thickness in a range of from 100 nm to 30 microns, including any value and range therebetween. In some embodiments, at least some of the coating is positioned perpendicular to the substrate. In some embodiments, the coating forms a layer in the form of a defined texture or pattern, such as, without being limited thereto, cones, or holes, or pillar structures, e.g., an array of pillars.

[098] In some embodiments the pattern (e.g., the cones) may have a truncated shape.

[099] In some embodiments, the coating is in the form of alignment pillar structures.

[0100] Hereinthroughout, the term "pillar" as used herein refers to a structure which passes through or extends from the cross-brace and has a generally-constant cross- section. Herein, in some embodiments, by "structure" it is meant to refer to pillars that are round-, band-, sleeve-, elliptical-, square-, rectangular-, triangle-, or star-shaped.

[0101] In some embodiments, the array of pillars has a total solid area coverage of from about 0.5% to about 95%, with respect to that total area of the surface on which the array is attached.

[0102] In some embodiments, the alignment pillar structures are arranged along a single straight line.

[0103] In some embodiments, a median distance (also referred to as "spacing") between the pillars is, 100 nm, 500 nm, 1 μιη, 2 μιη, 3 μιη, 4 μιη, 5 μιη, 6 μιη, 7 μιη, 8 μιη, 9 μιη, or 10 μιη, including any value and range therebetween.

[0104] In some embodiments, the spacing is in the range of 1 to 20 μιη. [0105] In some embodiments, the pillars are characterized by height of 2 to 20 micron, e.g., 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 μιη, including any value and range therebetween.

[0106] In some embodiments, the pillars are characterized by at least one dimension of length or with of 0.5 to 5 micron, e.g., 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, or 5 μιη, including any value and range therebetween.

[0107] In some embodiments, the size of the pillar described herein represents a median size of a plurality of pillars. In some embodiments, the coating is deposited on a polymeric surface, also referred to as "substrate".

[0108] Substrate or Substrate's surfaces usable according to some embodiments of the present invention can therefore be hard or soft, organic or inorganic surfaces, including, but not limited to, glass surfaces; porcelain surfaces; ceramic surfaces; polymeric surfaces such as, for example, plastic surfaces, rubbery surfaces, and surfaces comprising or made of polymers such as polypropylene (PP), polycarbonate (PC), high- density polyethylene (HDPE), amorphous polymers such as (but not limited to) poly methyl methacrylate (PMMA), polycarbonate (PC), styrene acrylonitrile (SAN), polyethylene terephthalate (PET) and polystyrene (PS), unplasticized polyvinyl chloride (PVC), and fluoropolymers including but not limited to polytetrafluoroethylene (PTFE, Teflon®); metallic surfaces (e.g., gold surfaces) or can comprise or be made of silicon, organosilicon, MICA, a polymers as described herein or include any combination of the above. Furtther exemplary substrate comprises, without limitation, shape memory polymers, liquid metals, alloys having a low melting point (e.g., Ga, InBi, and Woods alloy), and ceramics.

[0109] In some embodiments, the substrate is in the form selected from, without being limited thereto, a sheet or a film.

[0110] The substrate's surfaces as described herein can further be modified by various chemical and mechanical processes, including, for example, SAMs, PVD, lithography and plasma etching.

[0111] In some embodiments, the substrate's surface can be crystalline or non- crystalline and is typically utilized without further modification of its crystalline nature.

[0112] In some embodiments, the coating layer has a thickness of at least 100 nm. In some embodiments, the film has a thickness in a range of from 100 nm to 10 microns, including any integer therebetween. [0113] In some embodiment, at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, 99%, or 99.5% of the substrate is coated by the coating layer.

[0114] The term "superhydrophobic", or any grammatical derivative thereof, as used herein, may be determined by static contact angle measurement of a hydrophilic liquid having above 120°, above 130°, above 140°, or above 150°.

[0115] The term "superhydrophillity", or any grammatical derivative thereof, as used herein, may be determined by static contact angle measurement of a hydrophilic liquid of less than 50°, less than 40°, less than 30°, or less than 25°, less than 20°, less than 15°, less than 10°, or less than 5°.

[0116] As used herein, "static contact angle" describes the angle that a liquid substance forms with respect to the substrate surface at the place where the free surface of quiescent liquid contacts to the horizontal surface of the substrate.

[0117] Typically, but not exclusively, in order to measure the static contact angle, a drop of liquid is formed on the tip of a hypodermic needle attached to a screw syringe.

[0118] The syringe is fastened to a stand which reduces any irregularities that are produced by manual drop deposition. The substrate is then raised until it touches the drop using the Y control of the stage. The drop is the then brought into the field of view and onto the focal point of the microscope by x-y translation of the stage and image is captured. The static contact angle is calculated by methods known in the art.

[0119] The static contact angle of a surface corresponds to a tested liquid.

[0120] As used herein and in the art, a "hydrophilic liquid" is a substance which is liquid at room temperature and which readily interacts with or is dissolved by water and other polar substances.

[0121] Exemplary hydrophilic liquids include, but are not limited to, water, aqueous solutions, and any other liquids which are polar and dissolvable in water.

[0122] In some embodiments, the term, "crosslinked" and/or "crosslinking", as used herein, and any grammatical derivative thereof refers generally to a chemical process or the corresponding product thereof in which two chains of polymeric molecules are attached by bridges, a "cross-linker", composed of an element, a group or a compound, which join certain carbon atoms of the chains by primary chemical. Therefore, the general properties of a cross-linker compound, include: having bi- or poly-functional groups enabling attachment to at least two moieties.

[0123] In some embodiments, the transparency and superhydrophobic properties are durable. The term "durable" is defined as a composition which provides a benefit, or a property which remains stable upon subjecting to an aqueous or non-aqueous media, or other body fluids. By "stable" it is meant that the relevant property changes (e.g., the measured contact angle) within less 10%, less than 5%, or less than 1%, for at least on day, one week or for at least one month.

[0124] In some embodiments, the composition in any embodiments as disclosed herein, is characterized by low optic absorption in the visible light range. In some embodiments, the composition or the article is characterized by high transparency in the visible light range. In some embodiments, the article is characterized by high transparency in the visible light range. As used herein and in the art, visible light range refers to a range of from about 380 nm to about 780 nm.

[0125] By "antifogging", or any grammatical derivative thereof, it is meant to refer, inter alia, to the capability of a substrate's surface to prevent water vapor from condensing onto its surface in the form of small water drops redistributing them in the form of a continuous film of water in a very thin layer.

[0126] In some embodiments, the antifogging properties do not change significantly with time, when maintained both at room temperature, at elevated temperatures (e.g., 70-90 °C) and at lower temperatures (e.g., -50 °C).

[0127] In some embodiments, the composition herein exhibits antifogging properties that last for at least e.g., 1 h, 2 h, 3 h, 4 h, 5 h, 10 h, 1 day, 2 days, 3 days, 4 days, 5 days, or even at least several months.

[0128] Antifogging properties may be characterized visually or may be characterized or measured by one or more methods known in the art. Optionally, antifogging properties may be characterized by e.g., roughness, contact angle, haze and gloss or by a combination thereof.

[0129] In some embodiments, the coating layer is characterized by abrasion resistance.

[0130] The term "abrasion resistance" is used to denote resistance of the film to relatively mild abrasion throughout the entire thickness of the film.

[0131] Measurements of resistance of coatings to abrasion may be obtained by a Taber Abrasion Machine.

[0132] In some embodiments, the Taber Abrasion test provides less than 15%, or less than 10% haze change according to ASTM D1003.

[0133] In some embodiments, the composition is characterized by a defined pencil hardness. The term "pencil hardness" as used herein is meant to include but not be limited to a surface hardness defined by the hardest pencil grade that just fails to mar the coated surface. Typically, the pencil hardness of the film is in the range of 2H to 9H, or, in some embodiments from 3H to 6H.

[0134] In some embodiments, the weather resistance of the composition is characterized by Delta E of 0.2 to 1.5, e.g., 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, or 1.5, including any value and range therebetween, after 2000 hours according to ASTM G155 or similar method. The term "delta E" is indicative of the difference between the target color value and another color value.

[0135] In some embodiments, the weather resistance of the composition is characterized by Delta Yellowness index of less than 5, less than 3, or less than 1, less than 0.6, less than 0.5, or less than 0.4, according to ASTM E313 after 2000 hours according to ASTM G 155, or by any method known in the art method.

[0136] Specific Embodiments of the Composition

[0137] In one embodiment, there is provided a micrometric and/or nanometric textured coating which can be applied on polymer (or other) surfaces.

[0138] In another embodiment, there is provided a micrometric and/or nanometric textured coating where the coating is transparent.

[0139] In another embodiment, the micrometric -nanometric texture can be flexibly and specifically designed according to the application needs.

[0140] In another embodiment, the coating is anti-abrasive and/or anti-scratch and renders a highly durable surface.

[0141] In another embodiment, the coating includes UV-absorbing additives that improve even further the durability of the coated surface and the product.

[0142] In another embodiment, the coating can be treated with hydrophobic chemical entities to render a super-hydrophobic surface.

[0143] In another embodiment, the coating contains chemical entities to render a super- hydrophobic surface.

[0144] In another embodiment, the coating can be treated with hydrophilic chemical entities to render a super-hydrophilic surface.

[0145] In another embodiment, the coating contains chemical entities to render a super- hydrophilic surface.

[0146] The process

[0147] According to an aspect of some embodiments of the present invention there is provided a process of the coating a polymeric substrate, the process comprising the steps of applying a UV curable, anti-abrasive, anti-scratch, transparent, and/or hard coating onto the polymer surface and cross-linking the coating through a UV- transmitting template. In some embodiments, the template is micrometric-nanometric patterned.

[0148] As described herein, in some embodiments, the anti-abrasive nature of the cured coating renders high durability and significantly increases the lifetime of the surface and its properties. The process for the production of the coating may be introduced as a batch, semi-continuous (e.g., step-and-repeat) or a continuous process.

[0149] In some embodiments, the process comprises the steps of:

(i) providing polymer mold. In some embodiments, the polymer is an elastomer; (ii) casting an irradiation (e.g., UV)-transmitting desired material onto the polymer mold in a liquid form and curing it to create a template;

(iii) Coating the polymer sheet or film substrate with a liquid anti-abrasive coating;

(iv) cross-linking of the coating material. In some embodiments, the cross- linking is performed by irradiation assisted curing.

[0150] In some embodiments, the irradiation is performed in the ultraviolet range.

[0151] In some embodiments, the term, "crosslinked" and/or "crosslinking", as used herein, and any grammatical derivative thereof refers generally to a chemical process or the corresponding product thereof in which two chains of polymeric molecules are attached by bridges, a "cross-linker", composed of an element, a group or a compound, which join certain carbon atoms of the chains by primary chemical.

[0152] In some embodiments, the process comprises a step of peeling off the template so as to reveal the replicated micro-nano texture of the coating. This step allows fabricating replicated micro-nano structured replicas comprising a variety of materials, such as, without being limited thereto, polymers, e.g., shape memory polymers, liquid metals, and alloys that have a low melting point (e.g., Ga, InBi, and Woods alloy), and ceramics. Further embodiments of this step are described hereinbelow.

[0153] In some embodiments, the irradiation-transmitting template can be in the form of roll, band, or sleeve micro-textured surface.

[0154] In some embodiments, step (i) is performed in a soft-lithography technique.

[0155] In some embodiments, the soft-lithography technique includes two-step lithography process: firstly, the micro-nano patterned master is copied into an elastomeric polymer mold which thereafter may be easily removed from the initial master. [0156] In some embodiments, the process comprises, prior to step (i), a step of fabricating of a micro- or nano- patterned master (e.g., Si micro-patterned wafer).

[0157] In some embodiments, the master is fabricated and shaped (e.g., in the form of cones, holes, or a pillars array) by a technique selected from, without being limited thereto, photolithography, etching, or laser-patterning techniques.

[0158] In some embodiments, the process comprises, prior to step (ii) a step of cleaning the polymeric surface.

[0159] In some embodiments, the polymeric surface is cleaned prior to coating application (step (iii)) in order to remove any contamination or dust from the surface. This step allows to obtain a clean coating and the desired properties of the surface. The surface of the polymer may be treated with an ionizing air gun in order to remove static charges in the polymer surface that attract dust particles.

[0160] In exemplary embodiments, the polymer surface is cleaned with polar solvent, for example, without limitation, 1-propanol using a soft cloth that does not leave any residues (e.g. deer skin cloth). Additionally, or alternatively, the polymer surface may be pre-coated with a thin layer of a primer material that bonds to the coating and/or be pre-treated by surface activating techniques such, without being limited thereto, as plasma, corona or flame.

[0161] In some embodiments, the coating (step iii) is applied by a method selected from, without being limited thereto, roll coating, dip coating, spray coating, tambon coating, gravure coating, slot-die coating, comma-coating, or blade coating.

[0162] In some embodiments, the coating mixture may comprise one or more from: 1- methoxy-2-propanol (e.g., 20-95 wt%), trimethylol propane triacrylate (e.g., 0-45 wt%), pentaerythritol tetraacrylate (e.g., 2-20 wt%), hexamethylene diacrylate (e.g., 0- 10 wt%), diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (e.g., 0-6 wt%), pentaerythritol triacrylate, 2-methoxypropanol (e.g., 0-2 wt%).

[0163] In some embodiments, the coating mixture may comprise 20-70% solids, e.g., 20%, 30%, 40%, 50%, 60%, or 70% solids, including any value and range therebeween.

[0164] In some embodiments, the coating mixture is characterized by 0.9-1.1 g/cm³ density.

[0165] As described herein, in some embodiments, the coating is anti-abrasive and/or anti- scratch coating.

[0166] In some embodiments, the material casted onto the elastomeric polymer has a desired viscosity that allows for penetration into the pattern of the polymeric template. [0167] In some embodiments, the material casted onto the elastomeric polymer can be UV-cured.

[0168] In some embodiments, the UV-curing coating has a proper viscosity, typically but not exclusively, ranging from 1 to 100 cP, e.g., 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 99, or 100 cP, including any value and range therebetween, depending on the scale of the pattern.

[0169] In some embodiments, the coating mixture is characterized by kinematic viscosity of 7 tol3 cSt, e.g., 7, 8, 9, 10, 11, 12, or 13 cSt, including any value therebetween. In some embodiments, the coating mixture is characterized by dynamic viscosity of 6-12 mPa s, e.g., 6, 7, 8, 9, 10, 11, or 12, mPa s, including any value and range therebetween.

[0170] Typically but not exclusively, the finer the pattern the lower the viscosity.

[0171] In some embodiments, the viscosity may be regulated by using a specific solvent, e.g., a polar solvent, such as, without being limited thereto, 2-propyol or 1- methoxy-2-propanol, or any other solvent suitable for the specific coating technique according to the manufacturer's instructions. If necessary, the coating may be applied under mechanical pressure to allow a desired incorporation of the coating.

[0172] In some embodiments, the process further comprises a step of stabilizing the coating. In some embodiments, once the coating is applied onto the polymer surface it is left to set ("flash-off") for period of 90 to 300 seconds (also referred to as "flash off period"), e.g., 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, or 300 seconds, including any value and range therebetween.

[0173] In some embodiments, the flash-off is performed at room temperature.

[0174] The term "room temperature", as used herein, means a temperature between 22 °C to 28 ⁰C, e.g., 25 °C.

[0175] In some embodiments, the flash-off period allows obtaining the desired coating stabilization. In some embodiments, the flash-off period may be shortened by external means such as temperature, vacuum and forced convection.

[0176] In some embodiments, during step (iv) the irradiation-transmitting template is pressed onto the pre-cured liquid irradiation-curable anti-abrasive coating in such a way that the coating penetrates, at least to some extent, into the micro-nano pattern of the polymeric template. [0177] Optionally, venting channels are designed into the polymeric template in order to properly vent the air that may be trapped within the pattern.

[0178] By "properly vent" it is meant to refer to avoiding trapping of the air into the pattern depletions such that the pattern cannot be fully replicated.

[0179] Optionally, e.g., if the replication is not satisfactory, the coating viscosity must be reduced with a solvent as described hereinabove.

[0180] In some embodiments, during the cross-linking step of the coating (step (iv)), the pre-cured irradiation-curable liquid (material) is radiated with UV light.

[0181] Typically, but not exclusively, the UV light should be suitable- on the one hand, to pass through the UV-transmitting template with minimum absorption and, on the other hand to cure the coating so as to obtain its maximum hardness.

[0182] In some embodiments, this step includes setting up the optimal wavelength and intensity of the UV light, thereby allowing optimal curing. In some embodiments, the coating is cured until it reaches full cross-linking and its maximum abrasion resistance, typically pencil hardness of 2H for PC and 6H for PMMA.

[0183] In some embodiments, by "full cross-linking" it is meant to refer to at least 70% cross -linking, at least 80% cross -linking, at least 90% cross-linking, or at least 95% cross -linking.

[0184] In some embodiments, following the cross-linking step, the irradiation- transmitting template and the cured coat are cooled slowly, until the polymer reaches a temperature of at least 30°, at least 40°, or at least 50° below its glass transition temperature.

[0185] As described herein, in some embodiments, the irradiation-transmitting template is peeled off leaving the positive micro-nano pattern onto the UV-cured hard abrasion-resistant surface.

[0186] In some embodiments, the coating layer pattern is chemically treated by a method known in the art, with hydrophobic or hydrophilic precursors (for example, and without being limited thereto, silanes) in order to render the desired super-hydrophobic or, in some embodiments, super-hydrophilic surface.

[0187] Alternatively, the coating may already contain functionalized additives or chemical side groups which may give the coating layer the required functionality.

[0188] Specific Embodiments of the Process

[0189] In one embodiment, there is provided a process for producing a coating according to any embodiment disclosed herein, comprising the following steps: a. Producing a micro-nano patterned master;

b. Producing a replica (e.g. PDMS) of the master;

c. Producing an UV-transmitting template of the replica;

d. Cleaning the surface of the polymer;

e. Coating a polymer surface with a UV-curing coating;

f. Stabilizing the coating;

g. Applying the template onto the coating;

h. UV-curing the coating through the UV-transmitting template; i. Cooling the coating; and

j. Peeling the template.

[0190] In another embodiment, the process comprises the steps of:

a. Producing a micro-nano patterned master;

b. Producing a replica (e.g. PDMS) of the master;

c. Producing an UV-transmitting template of the replica;

d. Cleaning the surface of the polymer;

e. Coating a polymer surface with a UV-curing coating;

f. Stabilizing the coating;

g. Applying the template onto the coating;

h. UV-curing the coating through the UV-transmitting template; i. Cooling the coating;

j. Peeling the template; and

k. Treating the surface of the micro-nano patterned coating with hydrophobic chemical entities to render a super-hydrophobic surface.

[0191] In another embodiment, the process comprises the steps of:

a. Producing a micro-nano patterned master;

b. Producing a replica (e.g. PDMS) of the master;

c. Producing an UV-transmitting template of the replica;

d. Cleaning the surface of the polymer;

e. Adding a hydrophobic chemical additive to a UV-curing coating to render a hydrophobic coating;

f. Coating a polymer surface with a UV-curing hydrophobic coating g. Stabilizing the coating;

h. Applying the template onto the coating;

i. UV-curing the coating through the UV-transmitting template; j. Cooling the coating; and

k. Peeling the template.

[0192] In another embodiment, the process comprises the steps of:

a. Producing a micro-nano patterned master;

b. Producing a replica (e.g. PDMS) of the master;

c. Producing an UV-transmitting template of the replica;

d. Cleaning the surface of the polymer;

e. Coating a polymer surface with a UV-curing coating;

f. Stabilizing the coating;

g. Applying the template onto the coating;

h. UV-curing the coating through the UV-transmitting template; i. Cooling the coating;

j. Peeling the template; and

k. Treating the surface of the micro-nano patterned coating with hydrophilic chemical entities to render a super-hydrophilic surface.

[0193] In another embodiment, the process comprises the steps of:

a. Producing a micro-nano patterned master;

b. Producing a replica (e.g. PDMS) of the master;

c. Producing an UV-transmitting template of the replica;

d. Cleaning the surface of the polymer;

e. Adding a hydrophilic chemical additive to a UV-curing coating to render a hydrophobic coating;

f. Coating a polymer surface with a UV-curing hydrophilic coating; g. Stabilizing the coating;

h. Applying the template onto the coating;

i. UV-curing the coating through the UV-transmitting template; j. Cooling the coating; and

k. Peeling the template.

[0194] In another embodiment, the UV-transmitting template is a UV-transmitting roll/band/sleeve micro-textured surface.

[0195] In another embodiment, the coating can be applied from both sides/surfaces of a polymer.

[0196] In another embodiment, the process is a batch process, semi-continuous (step- and-repeat) or continuous process. [0197] In another embodiment, the process is an on-line process, i.e. the coating is applied at the same production line and time as the polymer product itself

[0198] General:

[0199] As used herein the term "about" refers to ± 10 %.

[0200] The terms "comprises", "comprising", "includes", "including", "having" and their conjugates mean "including but not limited to".

[0201] The term "consisting of means "including and limited to".

[0202] The term "consisting essentially of" means that the composition, method or structure may include additional ingredients, steps and/or parts, but only if the additional ingredients, steps and/or parts do not materially alter the basic and novel characteristics of the claimed composition, method or structure.

[0203] The word "exemplary" is used herein to mean "serving as an example, instance or illustration". Any embodiment described as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments and/or to exclude the incorporation of features from other embodiments.

[0204] The word "optionally" is used herein to mean "is provided in some embodiments and not provided in other embodiments". Any particular embodiment of the invention may include a plurality of "optional" features unless such features conflict.

[0205] As used herein, the singular form "a", "an" and "the" include plural references unless the context clearly dictates otherwise. For example, the term "a compound" or "at least one compound" may include a plurality of compounds, including mixtures thereof.

[0206] Throughout this application, various embodiments of this invention may be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.

[0207] Whenever a numerical range is indicated herein, it is meant to include any cited numeral (fractional or integral) within the indicated range. The phrases "ranging/ranges between" a first indicate number and a second indicate number and "ranging/ranges from" a first indicate number "to" a second indicate number are used herein interchangeably and are meant to include the first and second indicated numbers and all the fractional and integral numerals therebetween.

[0208] As used herein the term "method" refers to manners, means, techniques and procedures for accomplishing a given task including, but not limited to, those manners, means, techniques and procedures either known to, or readily developed from known manners, means, techniques and procedures by practitioners of the chemical, and mechanical arts.

[0209] It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination or as suitable in any other described embodiment of the invention. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments, unless the embodiment is inoperative without those elements.

[0210] Various embodiments and aspects of the present invention as delineated hereinabove and as claimed in the claims section below find experimental support in the following examples.

EXAMPLES

[0211] Reference is now made to the following examples which, together with the above descriptions, illustrate the invention in a non-limiting fashion.

[0212] In exemplary procedures, a micro-patterned silicon (Si) master was produced by photolithography and ion-etching method. This is done on 2" (50.8 mm) diameter [100]- oriented Silicon wafer with 100 nm S1O2 layer.

[0213] The sample was patterned with 1818 photoresist by GCA Autostep 200 DSW i- line Wafer Stepper UV exposure followed by tetra-methyl ammonium hydroxide (TMAH) aqueous alkaline development.

[0214] The pattern was then transferred onto the silicon dioxide layer, used as a hard mask, by CF₄/0₂ reactive ion etching (RIE) in a 790 PlasmaTherm tool. The subsequent etching of Silicon pillars to the depth of 10 μιη was carried out in a PlasmaTherm Versaline inductively coupled plasma (ICP) system by a deep reactive ion etching (DRIE) process. The etching process was terminated with C₄F₈ plasma (which is known to deposit a thin Teflon-like layer) in order to induce hydrophobic properties to the etched Silicon surface, followed by removal of residual photoresist in commercial solvent solution (see Figure 1).

[0215] In additional exemplary procedures, double -replication process was performed to produce a micro-nano patterned UV-cured UV-transmitting template produced from epoxy: (1) The initial Si master is covered by polydimethyl siloxane (PDMS, Dow- Sylgard 184), vacuum treated for 1 h and cured at 80°C for 3 h. (2, 3) This formed a PDMS mold which could be easily removed from the Si master. (4) A curable UV- transmitting epoxy OG-178 (Epoxy Technology) was poured over the PDMS mold and UV-cured until reaching full curing. (5) Following full curing, the micro-nano patterned UV-transmitting epoxy replica is peeled off from the PDMS. This UV-transmitting cured replica was used as a template to impress the micro-nano pattern onto the coated polymer surface (see Figure 2). Reference is made to Figure 3 showing a micro- patterned elastomeric mold produced from PDMS (left) and a micro-patterned UV- transmitting template produced from epoxy OG-178 (right) as fabricated.

[0216] Figure 4 shows a PMMA sheet being coated with a UV-curing anti-abrasive coating by a roll coating method as described herein. Figure 5 shows a micro-patterned epoxy template applied onto the UV-curing anti-abrasive coating. Figure 6 shows the anti-abrasive coating being UV-cured through a micro-patterned epoxy template. Figure 7 shows the polymer surface after the micro -patterned epoxy template has been peeled off. Figure 8 demonstrates a high resolution scanning electron microscopy (HR-SEM) top view image of the resulted polymer coating taken via In-Lens detector. Figure 9 shows a high magnification HR-SEM top view image of the resulted polymer coating taken via In-Lens detector. Figure 10 demonstrates a HR-SEM image of the resulted polymer coating obtained with a tilt of 7 deg. As can be estimated from the image the actual depth of the fabricated features on the surface of the polymer coating is around 6 μ m .

[0217] Table 1 shows a comparison between the original micro-pattern on Si master and the final micro-pattern obtained on the surface of the coated polymer. Table 1

[0218] Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims.

[0219] All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention. To the extent that section headings are used, they should not be construed as necessarily limiting.

Claims

WHAT IS CLAIMED IS:

1. A composition comprising a polymeric substrate having deposited on at least one surface thereof a cross-linked polymeric coating layer, wherein said coating layer is characterized by:

(i) nanosized or microsized surface pattern;

(ii) pencil hardness of 2H to 9H; and

(iii) water contact angle in a range of: 130° to 170°, or 10° to 50°.

2. The composition of claim 1, wherein said coating layer is further characterized by visible light transparency in a range of 70 to 95% in accordance to ASTM D1746.

3. The composition of any one of claims 1 or 2, wherein said coating layer comprises one or more ultraviolet (UV)-absorbent additives.

4. The composition of any one of claims 1 to 3, wherein said coating is characterized by water contact angle of at least 150°.

5. The composition of any one of claims 1 to 3, wherein said coating is characterized by water contact angle of less than 50°.

6. The composition of any one of claims 1 to 5, wherein said coating layer is covalently attached to said polymeric substrate.

7. The composition of any one of claims 1 to 6, wherein said coating layer is in the form of a textured pattern comprising an array of pillars.

8. The composition of any one of claims 1 to 6, wherein said coating layer is in the form of a textured pattern comprising an array of cones.

9. The composition of any one of claims 1 to 6, wherein said coating layer is in the form of a textured pattern comprising an array of holes.

10. The composition of any one of claims 7 to 9, wherein said array have pillars, cones, or holes, respectively, with a median height or depth of about 2 to about 20 micrometers.

11. The composition of any one of claims 7 to 10, wherein said array have pillars, cones, or holes having one or more dimensions selected from length, width, or diameter, characterized by about 0.5 to about 5 micrometers.

12. The composition of any one of claims 7 to 11, wherein said textured pattern comprises pillars, cones or holes having a median space therebetween of 1 to 20 micrometers.

13. The composition of any one of claims 7 to 12, wherein said pillars, cones or holes are round-, band-, sleeve-, elliptical-, square-, rectangular-, triangle-, or star- shaped.

14. The composition of any one of claims 7 to 13, wherein the array of pillars, cones or holes covers from about 0.5% to about 95%, of the total area of said at least one surface.

15. The composition of any one of claims 1 to 14, characterized by delta E color shift of no greater than 1.5, as tested according to ASTM G155 after 2000 hours.

16. The composition of any one of claims 1 to 15, characterized by Yellowness index of less than 5 according to ASTM E313 after 2000 hours according to ASTM G155

17. The composition of any one of claims 1 to 16, wherein said coating has attached thereto one or more hydrophobic groups or agents.

18. The composition of any one of claims 1 to 16, wherein said coating has attached thereto one or more hydrophilic groups or agents.

19. A process for producing the composition of claim 1, the process comprising the steps of:

(i) providing a polymeric mold;

(ii) casting a UV transmitting material onto the polymer mold in a liquid form and curing the material, thereby creating a template;

(iii) Coating the polymer sheet or film substrate with a liquid anti- abrasive coating; and

(iv) cross-linking of the coating material through the UV-transmitting template.

20. The process of claim 19, further comprising, prior to step (i), the steps of

(a) producing a micro- to nano- patterned maser; and

(b) producing a replica of said master.

21. The process of any of the claims 19 or 20, where said polymeric substrate is in the form of a sheet or film.

22. The process of any one of claims 19 to 21, further comprising a step of cooling the coating layer to a temperature of below 40 °C.

23. The process of any one of claims 19 to 22, further comprising a step of peeling the template.

24. The process of any one of claims 19 to 23, further comprising a step of adding or attaching a hydrophobic agent to said coating layer.

25. The process of any one of claims 19 to 24, further comprising a step of adding or attaching a hydrophobic agent to said coating layer.

26. The process of any one of claims 20 to 25, wherein said replica is a polymer comprising polydimethyl siloxane (PDMS).

27. The process of any one of claims 19 to 26, wherein said UV-transmitting material comprises a material having an epoxy group.

28. The process of any one of claims 19 to 27, wherein said coating comprises thermosetting polysiloxanes, polyurethanes, silicones, and acrylates with and without functional additives.

29. The process of any one of claims 19 to 28, further comprising a step of adding a UV-absorbent additive to said coating layer.

30. The process of any one of claims 19 to 29, wherein said UV-transmitting template is a UV-transmitting roll- band- or sleeve- micro-textured surface.