WO2016044880A1 - Article hydrofuge et son procédé de préparation - Google Patents

Article hydrofuge et son procédé de préparation Download PDF

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Publication number
WO2016044880A1
WO2016044880A1 PCT/AU2015/000585 AU2015000585W WO2016044880A1 WO 2016044880 A1 WO2016044880 A1 WO 2016044880A1 AU 2015000585 W AU2015000585 W AU 2015000585W WO 2016044880 A1 WO2016044880 A1 WO 2016044880A1
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WO
WIPO (PCT)
Prior art keywords
coating
article
group
substrate
poly
Prior art date
Application number
PCT/AU2015/000585
Other languages
English (en)
Inventor
Tong Lin
Hua Zhou
Hongxia Wang
Original Assignee
Deakin University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from AU2014903835A external-priority patent/AU2014903835A0/en
Application filed by Deakin University filed Critical Deakin University
Publication of WO2016044880A1 publication Critical patent/WO2016044880A1/fr

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Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61D—VETERINARY INSTRUMENTS, IMPLEMENTS, TOOLS, OR METHODS
    • A61D13/00—Thermometer holders specially adapted to veterinary purposes
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D169/00—Coating compositions based on polycarbonates; Coating compositions based on derivatives of polycarbonates
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
    • C07F7/00—Compounds containing elements of Groups 4 or 14 of the Periodic System
    • C07F7/02—Silicon compounds
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
    • C07F7/00—Compounds containing elements of Groups 4 or 14 of the Periodic System
    • C07F7/02—Silicon compounds
    • C07F7/08—Compounds having one or more C—Si linkages
    • C07F7/18—Compounds having one or more C—Si linkages as well as one or more C—O—Si linkages
    • C07F7/1804—Compounds having Si-O-C linkages
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L69/00—Compositions of polycarbonates; Compositions of derivatives of polycarbonates
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D127/00—Coating compositions based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Coating compositions based on derivatives of such polymers
    • C09D127/02—Coating compositions based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Coating compositions based on derivatives of such polymers not modified by chemical after-treatment
    • C09D127/12—Coating compositions based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Coating compositions based on derivatives of such polymers not modified by chemical after-treatment containing fluorine atoms
    • C09D127/16—Homopolymers or copolymers of vinylidene fluoride
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D183/00—Coating compositions based on macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon, with or without sulfur, nitrogen, oxygen, or carbon only; Coating compositions based on derivatives of such polymers
    • C09D183/04—Polysiloxanes
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D183/00—Coating compositions based on macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon, with or without sulfur, nitrogen, oxygen, or carbon only; Coating compositions based on derivatives of such polymers
    • C09D183/04—Polysiloxanes
    • C09D183/08—Polysiloxanes containing silicon bound to organic groups containing atoms other than carbon, hydrogen, and oxygen
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
    • C08G77/04—Polysiloxanes
    • C08G77/22—Polysiloxanes containing silicon bound to organic groups containing atoms other than carbon, hydrogen and oxygen
    • C08G77/24—Polysiloxanes containing silicon bound to organic groups containing atoms other than carbon, hydrogen and oxygen halogen-containing groups

Definitions

  • the present invention generally relates to a liquid repellent article.
  • the invention relates to a liquid repellent article comprising a micro-rough substrate and a substantially particle-free, nano-rough low surface energy coating on the substrate.
  • the invention also relates to a process for preparing the liquid repellent article.
  • the invention is particularly directed to liquid repellent textile articles, such as clothing, that comprise a substantially particle-free, nano-rough low surface energy coating, and to a process for the preparation of such textile articles.
  • Liquid repellent coatings have the potential to impart self-cleaning and contamination-resistant surface properties to a range of materials.
  • fabrics imbibed with liquid repellency are particularly useful for the development of protective clothing, which offers the wearer protection against toxic, flammable or corrosive liquids.
  • challenges still remain that hinder their effective, widespread use in practice.
  • Clothing and other textile articles having liquid repellent properties can be obtained by applying a liquid repellent coating, such as an amphiphobic or superamphiphobic coating, on to a fabric substrate.
  • a liquid repellent coating such as an amphiphobic or superamphiphobic coating
  • Amphiphobic and superamphiphobic coatings have both hydrophobic and oleophobic properties, with the ability to repel both water and oil.
  • Amphiphobic coatings typically exhibit a contact angle of greater than 90 degrees to water and oil, while superamphiphobic coatings generally exhibit a contact angle of greater than 150 degrees to water and oil.
  • Amphiphobic or superamphiphobic properties may be conferred to a material by forming a surface having a rough topography and low surface free energy on the material.
  • a coating composition containing a low surface energy binder and either micro- or nanoparticles dispersed in the binder, which may be applied to the material as a coating treatment.
  • the microparticles and nanoparticles employed in prior art coatings are typically either added to the coating or are formed in situ.
  • microparticles and nanoparticles to provide rough surfaces in liquid repellent coatings can be of concern for textile articles as the particles may affect the handling, wear and comfort of the textiles. There may also be potential health and safety issues surrounding the presence of microparticles and nanoparticles in the coatings.
  • liquid repellent surfaces can have poor repellency to low surface tension liquids, particularly those with a surface tension of less than 35 mN/m. Since low surface tension liquids are widely used in daily life and industry, the inability to repel these liquids has been an issue that restricts the wide use of many liquid repellent textiles.
  • a further important challenge for liquid repellent textiles is coating durability. For instance, many coatings on fabrics have low durability and can only withstand limited washing and abrasion before its ability to effectively repel liquids is compromised.
  • the present invention relates generally to a liquid repellent article and to a process for the preparation of a liquid repellent article.
  • the liquid repellent article is capable of repelling both water and oil.
  • the present invention provides an amphiphobic article, preferably a superamphiphobic article.
  • the present invention provides a liquid repellent article comprising a substrate having a micro-rough surface and a substantially particle-free coating on the micro-rough surface of the substrate, wherein the coating comprises at least one low surface energy polymer and at least one coupling agent and has a nano-rough topography, and wherein the article is capable of repelling both water and oil.
  • the substrate employed in the liquid repellent article of the invention has a micro-rough surface.
  • the substrate having a micro-rough surface may be selected from the group consisting of porous substrates, fibrous substrates (e.g. wovens, non-wovens, knitted, braided), fibres, yarns, porous films and foams.
  • the substrate may be selected from the group consisting of a mesh, paper and fabric substrate.
  • the liquid repellent article of the present invention also comprises a substantially particle-free low surface energy coating on the micro-rough surface of the substrate.
  • the low surface energy coating has a nano-rough topography.
  • the substantially particle-free coating has a RMS roughness of between 10 to 200 nm.
  • the low surface energy coating employed in the liquid repellent article is substantially free of particles such as microparticles and nanoparticles. In one set of embodiments the coating comprises less than 0.5% (w/v) particles.
  • the substantially particle-free coating present in the liquid repellent article comprises at least one coupling agent.
  • the substantially particle-free coating comprises a silane coupling agent.
  • Exemplary silane coupling agents may comprise at least one hydrolysable group and at least one non-hydrolysable group.
  • the non-hydrolysable group may comprise a moiety selected from the group consisting of hydrocarbyl and halocarbyl moieties.
  • the non-hydrolysable group imparts low surface energy properties to the coupling agent.
  • the silane coupling agent is of formula (I):
  • R 1 is a hydrolysable group and at each occurrence is independently selected from the group consisting of alkoxy, alkenyloxy and halo,
  • R 2 is a hydrolysable group selected from the group consisting of alkoxy, alkenyloxy and halo, or
  • R 2 is a non-hydrolysable group comprising a moiety selected from the group consisting of alkyl, alkenyl, alkynyl, alkylepoxy, alkyl ethers, alkyl esters, aryl, cycloalkyi, fluoroalkyi, fluoroether, fluoroester, fluoroaryl, and polyhedral oligomeric silsequioxane; and
  • R 3 is a non-hydrolysable group comprising a moiety selected from the group consisting of alkyl, alkenyl, alkynyl, alkylepoxy, alkyl ethers, alkyl esters, aryl, cycloalkyi, fluoroalkyi, fluoroether, fluoroester, fluoroaryl, and polyhedral oligomeric silsequioxane.
  • the substantially particle-free coating comprises an amount of coupling agent in a range of from about 0.5 to 10% (v/v), preferably from about 1 to 5% (v/v).
  • the substantially particle-free coating present in the liquid repellent article also comprises at least one low surface energy polymer.
  • the coating comprises a polymer having a surface free energy of no more than about 50 mN/m at 20°C.
  • the substantially particle-free coating comprises a low surface polymer selected from the group consisting of polyolefins, fluoropolymers, perfluoropolymers, vinyl polymers, polysiloxanes, polyesters, polyurethanes, polycarbonates, copolymers thereof, and mixtures thereof.
  • the low surface energy polymer may be selected from the group consisting of polyethylene, polyisobutylene, polystyrene, poly(a-methyl styrene), polyvinylchloride, poly(vinylidene fluoride), poly(vinylidene fluoride-co- hexafluoropropene), polyvinyl acetate), polytrifluoroethylene, polytetrafluoroethylene, poly(chlorotrifluoroethylene), poly(ethyl acrylate), poly(ethyl methacrylate), poly(butyl methacrylate), poly(iso-butyl methacrylate), poly(hexyl methacrylate), poly(tetramethylene oxide), polydimethylsiloxane, polycarbonates, polyesters, polyurethanes, fluorinated olefin-based polymers, fluoroacrylates, fluorosilicone acrylates, fluorourethanes, and mixture
  • the substantially particle-free coating may comprise a suitable amount of low surface energy polymer and the quantity may depend on the desired thickness and/or coverage of coating on the underlying substrate.
  • the coating comprises an amount of low surface energy polymer in a range selected from the group consisting of from about 0.2 to 10% (w/v), from about 0.5 to 5% (w/v), and from about 1 to 3% (w/v).
  • the present invention provides a process for the preparation of a liquid repellent article comprising the steps of: applying a substantially particle-free coating composition comprising a low surface energy polymer, coupling agent, and a volatile carrier to a micro-rough surface of a substrate; and evaporating the volatile carrier from the coating composition applied on the substrate to thereby form a substantially particle-free coating on the substrate, wherein the coating comprises the low surface energy polymer and coupling agent and has a nano-rough topography, and wherein the article is capable of repelling both water and oil.
  • the process of the present invention provides an effective and facile method for forming a liquid repellent article that is capable of repelling a range of different liquids and most particularly is capable of repelling water and oil.
  • the process of the invention advantageously avoids the need to employ particles such as nanoparticles and microparticles in the manufacture of the liquid repellent article.
  • the process of the invention employs a substantially particle-free coating composition comprising a low surface energy polymer, a coupling agent, and a volatile carrier.
  • the coating composition may comprise at least one low surface energy polymer and at least one coupling agent selected from any one of those described herein.
  • the low surface energy polymer and coupling agent are typically dissolved in the volatile carrier.
  • the coating composition be a homogeneous liquid comprising the polymer, coupling agent and volatile carrier in a single phase.
  • the volatile carrier comprises at least one volatile solvent.
  • Volatile solvents useful in the process of the invention may have a vapour pressure of at least 10 kPa at 20°C. It is preferred that the volatile carrier be capable of rapidly evaporating under ambient conditions.
  • the volatile carrier may comprise at least one volatile solvent selected from the group consisting of alcohols (preferably C1 -C4 alcohols), glycols, ethers, esters, ketones, amides, and halohydrocarbon solvents.
  • Exemplary volatile solvents may be selected from the group consisting of trichloroethane, trichloroethylene, methylene chloride, chloroform, carbon tetrachloride, tetrachlorethylene, methanol, ethanol, propanol, butanol, ethylene glycol, diethyl ether, ethyl acetate, acetone, N, N-dimethylformamide, and tetrahydrofuran.
  • the volatile carrier comprises an aqueous mixture of the volatile solvent.
  • the ratio of water, when used, to volatile solvent will depend on the nature of the volatile solvent and other components of the composition as well as the drying conditions to be used.
  • the volume ratio of watenvolatile solvent is no more than 1 :1 such as no more than 1 :2, no more than 1 :4 or no more than 1 :8.
  • the coating composition may comprise a suitable amount of low surface energy polymer and coupling agent and the quantity may depend on factors such as the solubility of the polymer and coupling agent in the volatile carrier, as well as the desired thickness and/or coverage of resulting coating.
  • the coating composition may comprise an amount of coupling agent in a range of from about 0.5 to 10% (w/v), preferably from about 1 to 5% (w/v).
  • the coating composition may comprise an amount of low surface energy polymer in a range selected from the group consisting of from about 0.2 to 10% (w/v), from about 0.5 to 5% (w/v), and from about 1 to 3% (w/v).
  • the coating composition is applied to a substrate having a micro-rough substrate.
  • substrates having micro-rough surfaces may be selected from any one of those described herein.
  • the substrate may be selected from the group consisting of porous substrates, fibrous substrates (e.g. wovens, non-wovens, knitted, braided), fibres, yarns, films and foams.
  • the substrate may be selected from the group consisting of a mesh, paper and fabric substrate.
  • Any suitable technique may be used to apply the coating composition, including dipping, spraying, brushing, padding, roll coating, curtain coating, or any combination of such techniques.
  • the volatile carrier is evaporated from the applied composition. Evaporation results in the removal of a substantial proportion of the volatile carrier and in the formation of a coating comprising the low surface energy polymer and coupling agent on the micro-rough substrate surface.
  • rapid evaporation means that a substantial proportion (such as least 50%, at least 60%, at least 70%, at least 80% or at least 90%) of the volatile solvent is removed from the coating composition applied to the substrate in a time period of less than 10 minutes, preferably less than 8 minutes, more preferably less than 5 minutes.
  • time period for solvent evaporation can vary, as it might depend on variables such as the thickness and surface area of the applied coating, as well as the environmental conditions under which the volatile carrier is removed.
  • the evaporation of the volatile carrier may occur under a range of conditions, including under ambient conditions or at elevated temperature. In one set of embodiments, evaporation of the volatile carrier from the coated substrate occurs at an elevated temperature, preferably at a temperature in the range of from about 60 to 140°C.
  • the evaporation of the volatile carrier may also be facilitated by the use of a flow of air, which may be directed across the coating composition applied to the substrate.
  • a flow of air may be used in conjunction with an elevated temperature to facilitate rapid evaporation of the volatile carrier.
  • the process of the invention may further comprise the step of curing the substantially particle-free coating formed on the substrate.
  • the curing step is preferably carried out at elevated temperature. In some embodiments, the curing step is carried out at a temperature in a range of from about 50 to 160°C.
  • the curing step may facilitate covalent reactions of the coupling agent, either with itself or other components of the coating composition, or with the substrate, to crosslink the coupling agent or to help bond the coating to the substrate.
  • a substantially particle-free low surface energy coating is formed on the substrate.
  • the coating comprises the low surface energy polymer and coupling agent.
  • the coating formed by the process of the invention also comprises a nano-rough topography.
  • the nanostructure of the coating is such that the surface of the coating is nano rough.
  • the nano-rough topography is achieved without the need to incorporate particles such as microparticles or nanoparticles in the coating, or the need to disperse particles in between the coating and the underlying substrate.
  • the liquid repellent article of the present invention may be substantially particle-free.
  • the substantially particle-free nano-rough coating covers the micro-rough surface of the substrate and operates in conjunction with the substrate to impart liquid repellent properties to the resulting article.
  • the liquid repellent properties are such that the article is capable of repelling both water and oil.
  • Other liquids or solvents, in particular, low surface tension liquids, may also be repelled by the articles of the present invention.
  • the present invention also provides a liquid repellent article prepared by the process of any one of the embodiments described herein.
  • An article that is liquid repellent generally means that the article provides a high liquid contact angle for a liquid that is in contact with the article.
  • the liquid repellent article of one or more aspects of the invention may provide a liquid contact angle of at least about 90 degrees, at least about 120 degrees, or at least about 150 degrees.
  • a liquid repellent article of one or more aspects of the invention is amphiphobic and capable of repelling both water and oil.
  • the liquid repellent article may be superamphiphobic.
  • the liquid repellent article of one or more aspects of the invention possesses a number of advantageous properties, such as being capable of self-cleaning as well as being durable and resistant to damage by abrasion, chemicals, high temperature treatment and repeated washing.
  • the liquid repellent article of embodiments of the invention may furthermore retain an acceptable aesthetic appearance and be air permeable.
  • a liquid repellent article of one or more embodiments of the invention is capable of withstanding at least 100 washing cycles, when tested according to AATCC Test Method 61 -2006.
  • a liquid repellent article of one or more embodiments of the invention is capable of withstanding 10,000 cycles of abrasion, when tested according to ASTM D4966-98.
  • the coating present in the liquid repellent article is capable of self-healing after damage, thus imparting self-healing properties to the article.
  • the self-healing property is repeatable.
  • the liquid repellent article is a textile article comprising a fabric substrate and a substantially particle-free low surface energy coating as described herein on a surface of the fabric substrate.
  • the low surface energy coating has a nano-rough topography.
  • the present invention therefore is particularly useful in the preparation of textile articles that are highly repellent to liquids, and may be used to resist damage and soils, such as protective clothing.
  • Figure 1 is a schematic illustrating a process for the preparation of a liquid repellent article in accordance with an embodiment of the invention
  • Figure 2 is a schematic illustrating the formation of a liquid repellent textile article in which a fabric substrate is coated with a composition comprising a silane coupling agent and a low surface energy polymer in accordance with an embodiment of the invention
  • Figure 3 shows an image of droplets of ethanol, water, olive oil and hexadecane on a liquid repellent article of an embodiment of the invention and an image of a comparative uncoated substrate that is not liquid repellent;
  • Figure 4 is a graph illustrating the change in contact angle (CA) over time for droplets of ethanol, water, olive oil and hexadecane on a liquid repellent article of an embodiment of the invention;
  • Figure 5 is a graph illustrating the dependency of contact angle (CA) and sliding angle (SA) with liquid surface tension for a liquid repellent article of an embodiment of the invention
  • Figure 6 is an image showing that a liquid repellent article of an embodiment of the invention maintains liquid repellent properties after immersion in 40% KOH and 40% H 2 S0 4 for 12 hours;
  • Figure 7 is a graph illustrating a change in contact angle for various liquids in contact with liquid repellent articles of embodiments of the invention comprising varying ratios of coupling agent and polymer in the coating.
  • the present invention provides a liquid repellent article that is capable of repelling both water and oil.
  • the liquid repellent article of the invention does not require the presence of particles, such as microparticles and nanoparticles, in order to achieve rough surface topographies which are conventionally required to impart liquid repellency.
  • the present invention provides a liquid repellent article comprising a substrate having a micro-rough surface and a substantially particle-free low surface energy coating on the micro-rough surface of the substrate, wherein the coating has a nano-rough topography, and wherein the article is capable of repelling both water and oil.
  • the low surface energy coating comprises at least one low surface energy polymer and at least one coupling agent.
  • the present invention provides a liquid repellent article comprising a substrate having a micro-rough surface and a substantially particle-free coating on the micro-rough surface of the substrate, wherein the coating comprises at least one low surface energy polymer and at least one coupling agent and has a nano-rough topography, and wherein the article is capable of repelling both water and oil.
  • the liquid repellent article of the invention has both hydrophobic and oleophobic properties.
  • the liquid repellent article can therefore be regarded as an amphiphobic article and in some embodiments, is a superamphiphobic article.
  • the liquid repellent article of the present invention comprises a substrate having a micro-rough surface.
  • a substrate having a micro-rough surface generally has non-planar topography that may arise as a result of the morphology or surface features of the substrate.
  • the substrate comprises microscale roughness with uneven surface features evident on a micrometre scale.
  • a substrate with a "micro-rough" surface may have a surface comprising profile peaks having a height in a range from 0.1 ⁇ to 50 ⁇ and a distance between the profile peaks in a range from 1 ⁇ to 50 ⁇ .
  • a micro-rough surface of a substrate may comprise profile peaks having a height and distance in a range of 5 ⁇ to 30 ⁇ .
  • a substrate having a micro-rough surface may be selected from the group consisting of porous substrates, woven substrates, non- woven substrates, braided substrates, fibres, yarns, films (including thin films) and foams.
  • the substrate may further be a flexible substrate.
  • the substrate is a porous substrate.
  • Porous substrates comprise at least one opening, and may comprise a plurality of openings, in the substrate. Such substrates are generally air permeable.
  • Porous substrates that may be used can be in any form, including in the form of sheets, webs, foams and films. Examples of porous substrates include woven and non-woven fabrics and textiles, foam sheets and woven and non-woven papers.
  • the substrate may be a thin porous substrate having a thickness selected from the group consisting of less than about 10 mm, less than about 5 mm or less than about 1 mm.
  • the substrate may be a textile substrate.
  • textile substrates include woven, non-woven, knitted or braided fabrics, fibres, filaments, yarns, etc.
  • the substrate may be a fabric substrate.
  • the fabric substrate may be woven, non-woven, braided or knitted substrate, and may be formed from synthetic or natural fibres, either alone or blended in any combination thereof.
  • the fabric substrate may comprise a fibre selected from the group consisting of cotton, cellulose, wool, cashmere, angora, silk, and combinations thereof.
  • the fabric substrate comprises cotton, wool or silk.
  • Fabric substrates may also be considered porous substrates due to their air permeability.
  • the liquid repellent article of the invention also comprises a substantially particle-free coating.
  • a reference to a composition or coating being “substantially particle-free” generally means that the composition or coating contains (on a w/v basis) less than 5%, less than 2%, less than 1 %, or less than 0.5% particles. Most preferably, the coating contains no particles.
  • microparticle as used herein is generally a reference to microparticles and nanoparticles. Such particles have been used in liquid repellent coatings, such as hydrophobic or amphiphobic coatings described in the prior art and desirably, are not employed in the liquid repellent article of the present invention, nor are they employed in processes or coatings used to form the liquid repellent article of the invention .
  • Microparticles that are excluded from the present invention described herein generally have at least one particle dimension in the micrometre ( ⁇ ) range, while nanoparticles that are excluded from the present invention generally have at least one particle dimension in the nanometre scale. In general, it is desirable that nanoparticles having a particle dimension of 5 nm or greater be excluded or substantially excluded from liquid repellent articles, coatings and coating compositions as described herein.
  • Percentages referred to herein are generally percentages by volume (e.g. %w/v) unless otherwise specified.
  • the substantially particle- free coating of the liquid repellent article comprises a low surface energy polymer and a coupling agent.
  • a variety of low surface energy polymers may be used in the coating.
  • the low surface energy polymer may be selected from any polymer that is able to effectively reduce the surface energy of a substrate to which the coating has been applied.
  • Low surface energy polymers are available commercially and may also be synthesised from appropriate monomers using various polymerisation techniques. In some embodiments it may be desirable for the low surface energy polymers employed in the coating be non-crosslinked.
  • the coating comprises at least one low surface energy polymer having a surface free energy selected from the group consisting of no more than about 50 mN/m, no more than about 40 mN/m, and no more than about 35 mN/m at 20°C.
  • the substantially particle-free coating may comprise a single type of low surface energy polymer, or it may comprise a mixture of two or more different types of such polymers.
  • each polymer has a surface free energy of no more than about 50 mN/m, no more than about 40 mN/m, and no more than about 35 mN/m, at 20°C. It is further desirable that the polymers be compatible with one another and miscible with the other components of the coating so as to form of a single phase. In some embodiments it is desirable that the components of the low surface energy coating do not phase separate.
  • the coating may comprise at least one polymer selected from the group consisting of polyolefins, halogenated polymers (such as fluoropolymers and perfluoropolymers), vinyl polymers, polysiloxanes, polyesters, polyurethanes, polycarbonates, copolymers thereof, and mixtures thereof.
  • polyolefins, fluoropolymers and perfluoropolymers may be preferred.
  • the coating may comprise a polymer selected from the group consisting of polyethylene (including low density polyethylene and copolymers of polyethylene and polycyclic olefin), polyisobutylene, cyclic olefin copolymers such as ethylene-norbornene copolymer, polystyrene, poly(a-methyl styrene), polyvinylchloride, poly(vinylidene fluoride), poly(vinylidene fluoride-co- hexafluoropropene), polyvinyl chloride), polyvinyl acetate), polytrifluoroethylene, poly(chlorotrifluoroethylene), poly(methyl acrylate), poly(ethyl acrylate), poly(methyl methacrylate), poly(ethyl methacrylate), poly(butyl methacrylate), poly(iso-butyl methacrylate), poly(hexyl methacrylate), poly(ethylene (including low density polyethylene and copolymers
  • Polyvinylidene fluoride 30.3 poly(vinylidene fluoride-co-hexafluoropropylene) 19.2
  • the coating may comprise at least one polymer selected from the group consisting of low density polyethylene, poly(vinylidene fluoride), poly(vinylidene fluoride-co-hexafluoropropene), polyvinyl chloride), polyvinyl acetate), polytrifluoroethylene, polytrifluoroethylene, polyvinyl fluoride, poly(chlorotrifluoroethylene), cyclic olefin copolymer, polydimethylsiloxane and mixtures thereof.
  • the substantially particle-free coating may comprise a suitable amount of low surface energy polymer.
  • the coating comprises an amount of low surface energy polymer selected from the group consisting of from about 0.2 to 10% (wt/v), from about 0.5 to 5% (wt/v), and from about 1 to 3% (wt/v).
  • the coating employed in the liquid repellent article of the invention also comprises a coupling agent.
  • the coupling agent is preferably a low surface energy coupling agent.
  • Low surface energy coupling agents may comprise at least one moiety that imparts low surface energy properties.
  • the coating may possess enhanced low surface energy properties due to the presence of the coupling agent. Enhancements in low surface energy properties may be provided by the coupling agent and low surface energy polymer operating in combination or synergistically in the coating.
  • the coupling agents useful for the present invention may comprise at least one low surface energy moiety selected from the group consisting of hydrocarbyl and halocarbyl moieties.
  • low surface energy moieties include alkyl, aryl, haloalkyl (preferably fluoroalkyl or perfluoroalkyl) and haloaryl (preferably fluoroaryl) moieties.
  • the coupling agent may assist to enhance adhesion or bonding of the coating with the underlying substrate.
  • the selection of coupling agent may be dependent on the type of low energy polymer employed in the coating and the nature of the substrate of the liquid repellent article.
  • a single type of coupling agent may be employed, or a combination of two or more different types of coupling agent.
  • the coupling agent is a silane coupling agent.
  • Silane coupling agents are compounds comprising a silane head group and functional groups that are capable of bonding with different materials. Bonding interactions between the silane coupling agent and different materials may occur through hydroxyl groups present in the coupling agent.
  • silane head group refers to a moiety comprising a silicone (Si) atom and a hydrolysable group covalently bonded to the Si atom.
  • silane coupling agents employed in the coating comprise at least one low surface energy group, and may comprise a plurality (such as two or three) low surface energy groups.
  • the silane head can bond with polar groups present on a substrate surface, while the low surface energy group has strong affinity with the low surface energy polymer.
  • the coupling agent may act as a binder between the substrate and polymer in the coating to promote adhesion between the materials.
  • exemplary silane coupling agents may comprise a hydrolysable group and at least one non-hydrolysable group.
  • the non- hydrolysable group imparts low surface energy properties to the coupling agent.
  • the non-hydrolysable group may be considered to be a low surface energy group.
  • the non-hydrolysable group may be selected from the group consisting of hydrocarbyl and halocarbyl groups.
  • the silane coupling agent may comprise a non- hydrolysable group comprising a moiety selected from the group consisting of alkyl, aryl, haloalkyl (preferably fluoroalkyl or perfluoroalkyl) and haloaryl (preferably fluoroaryl).
  • exemplary alkyl and haloalkyl may comprise at least 4 carbon atoms while exemplary aryl and haloaryl may comprise at least 6 carbon ring atoms.
  • the silane coupling agent may comprise at least one non-hydrolysable group comprising a moiety selected from the group consisting of Ci to C 2 o alkyl, C 2 to C 30 alkenyl, C 3 to C-io alkyl epoxy, C5 to C- 20 aryl, Ci to C 20 haloalkyl, C3 to C- 2 o cycloalkyl and C 2 to C 2 o cyanoalkyl.
  • the non- hydrolysable group comprises a moiety selected from the group consisting of Ci to C 20 alkyl, C 5 to C-10 aryl and Ci to C 20 haloalkyl (such as Ci to C 20 perfluoroalkyl moiety).
  • the silane coupling agent may comprise a non- hydrolysable group comprising a long chain alkyl moiety.
  • Long chain alkyl may comprise at least 4 carbon atoms and may be C8-C20 alkyl. Long chain alkyl may help to provide a coating having greater liquid repellency than coatings formed with silane compounds having shorter alkyl substituents.
  • Some examples of long chain alkyl are octyl and hexadecyl.
  • the silane coupling agent may comprise a non- hydrolysable group comprising a haloalkyl moiety.
  • the haloalkyl may be fluoroalkyl or perfluoroalkyl.
  • the non-hydrolysable group comprises a Ci to C20 perfluoroalkyl moiety.
  • An exemplary perfluoroalkyl moiety is - (CH 2 )2-(CF 2 )5-CF3. Without wishing to be limited by theory, it is believed that fluorinated alkyl chains may be advantageous in assisting to impart a low surface free energy to the coating that results after application of the coating composition to the surface of a substrate.
  • silane coupling agents employed in the process and coating of the invention have a structure of formula (I):
  • R 1 is a hydrolysable group and at each occurrence is independently selected from the group consisting of alkoxy, alkenyloxy and halo;
  • R 2 is a hydrolysable group selected from the group consisting of alkoxy, alkenyloxy and halo; or
  • R 2 is a non-hydrolysable group comprising a moiety selected from the group consisting of alkyl, alkenyl, alkynyl, alkylepoxy, alkyl ethers, alkyl esters, aryl, cycloalkyl, fluoroalkyl, fluoroether, fluoroester, and polyhedral oligomeric silsequioxane; and R 3 is a non-hydrolysable group comprising a moiety selected from the group consisting of alkyl, alkenyl, alkynyl, alkylepoxy, alkyl ethers, alkyl esters, aryl, cycloalkyi, cyanoalkyi, fluoroalkyi, fluoroether, fluoroester, and polyhedral oligomeric silsequioxane.
  • R 3 comprises a moiety selected from the group consisting of Ci to C20 alkyl, C2 to C30 alkenyl, C5 to do aryl, Ci to C20 haloalkyl, C3 to C10 cycloalkyi and C 2 to C 2 o cyanoalkyi.
  • R 3 comprises a moiety selected from the group consisting of Ci to C 20 alkyl, C 5 to do aryl, and Ci to C 20 haloalkyl.
  • hydrolysable group of the coupling agent may be reactive under hydrolysis conditions and under such conditions, may form covalent bonds with appropriate functional groups present on other molecules or compounds.
  • a silane coupling agent undergoes hydrolysis and forms a covalent bond with another molecule, a hydrolysate of the coupling agent is produced.
  • the coating of the liquid repellent article may comprise a hydrolysate of at least one silane coupling agent.
  • the silane coupling agent may be selected from any one of those described herein.
  • the non-hydrolysable group is not reactive under hydrolysis conditions.
  • the non-hydrolysable group can generally impart low surface energy properties to the coupling agent.
  • R 3 comprises a moiety selected from the group consisting of Cs to C 2 o alkyl, and Ci to C 2 o perfluoroalky.
  • the silane coupling agent may be a trialkoxysilane.
  • Trialkoxysilanes include three hydrolysable groups and one non-hydrolysable group.
  • the non-hydrolysable group preferably comprises a moiety as described herein. Examples of suitable trialkoxysilanes that may be used in accordance with the invention are as follows:
  • Alkyl [0100] Methyl-tripropoxysilane, Trimethoxymethylsilane, Methyltris(tri-sec- butoxysilyloxy)silane, 1 -(Triethoxysilyl)-2-pentene, Ethyltrimethoxysilane, Propyltriethoxysilane, Trimethoxy(propyl)silane, Triethoxy(isobutyl)silane, lsobutyl(trimethoxy)silane, Triethoxy(octyl)silane, Trimethoxy(octyl)silane, Dodecyltriethoxysilane, Hexadecyltrimethoxysilane, Trimethoxy(octadecyl)silane, Octyl triethoxysilane.
  • Chloropropyl)triethoxysilane (Pentafluorophenyl)triethoxysilane, Triethoxy(4- (trifluoromethyl)phenyl)silane, 1 ⁇ , ⁇ /-/,2/-/,2/-/-Perfluorooctyltriethoxysilane, Trimethoxy(3,3,3-trifluoropropyl)silane, Tridecafluorooctyl triethoxysilane,
  • Triethoxyphenylsilane Triethoxy-p-tolylsilane, Triethoxy(4- methoxyphenyl)silane, Trimethoxy(2-phenylethyl)silane , Triethoxy(1 phenylethenyl)silane.
  • silane coupling agents employed in the coating of the liquid repellent article of the invention may be selected from polyhedral oligomeric silsequioxane agents having a structure of formula (II):
  • R is a non-hydrolysable group comprising a moiety selected from the group consisting of alkyl, alkenyl, alkynyl. alkylepoxy, alkyl ethers, alkyl esters, aryl. cycloalkyi, haloalkyl, haloether, haloester, polyhedral oligomeric silsequioxane. and fluorinated derivatives thereof; and
  • R ' is of formula (III):
  • R 3 (in ) wherein in formula (III): at least one of R 2 and R 3 is covalently bonded to formula (II), through a -C-Si- bond; R 2 and R 3 when not bonded to formula (II) represents a hydrolysable group comprising a moiety selected from the group consisting of alkoxy, alkenyloxy and halo; and
  • R 1 is a hydrolysable group and at each occurrence is independently selected from the group consisting of alkoxy, alkenyloxy and halo.
  • silane coupling agent of formula (II) examples include 1 H,1 H,2H,2H-heptadecafluorodecyl polyhedral oligomeric polysilsequioxane (heptadecafluorodecyl POSS) and iso-butyl polyhedral oligomeric polysilsequioxane (iso-butyl POSS).
  • silane coupling agents of formula (II) belong to the class of polyhedral oligomeric silsequioxane coupling agents. Such coupling agents are generally regarded as large molecular entities. While they might be considered to be particulate in nature, the molecular size of these compounds is generally less than 2 nm, and thus they are not considered to be nanoparticles and are not excluded from coatings and coating compositions of embodiments of the invention described herein.
  • the coating of the liquid repellent article may comprise at least one silane coupling agent of formula (I) and (II), and mixtures thereof.
  • the silane coupling agent may comprise one or more functional moieties that confer additional functionality or properties to the coating.
  • functional moieties include chromophores, luminescents, UV absorbing agents, antimicrobial agents, and antistatic agents.
  • the functional moiety may be included as a moiety within a non-hydrolysable group of the coupling agent.
  • Such functionalised silane coupling agents have been described in the prior art such as Lin et al, Fibers Polym. 2008, 9(5):521 -6; Zareba-Grodz et al, Journal of Luminescence, 2006, 1 19-120(0):148-52; Mohorcic ef al, J Mater Sci: Mater Med.
  • the coupling agent may be a fluorinated hydrocarbyl silane.
  • fluorinated hydrocarbyl silanes comprise silicone atoms bonded to four chemical groups. One or more of these groups contains fluorinated alkyl or aryl moieties that are not hydrolysable, and the remaining groups(s) attached to the silicon atoms are typically alkoxy (i.e. hydrocarbon attached to oxygen), or halide (e.g. chlorine) group(s).
  • alkyl As used herein, the terms “alkyl”, “alkenyl and alkynyl” refers to both linear (straight chain) and branched hydrocarbon structures.
  • the coupling agent may be a fluorinated silane coupling agent selected from the group consisting of 1H, 1H, 2H, 2H- perfluorodecyltriethyoxysilane (CF 3 (CF2)7(CH2)2Si(OCH 2 CH3)3), 3,3,3- trifluoropropyltrimethoxysilane (CF 3 (CH 2 ) 2 Si(OCH 3 ) 3 ), tridecafluoro-1 ,1 ,2,2- tetrahydrooctyl-1 -triethoxysilane (CF 3 (CF 2 ) 5 (CH 2 ) 2 Si(OCH 2 CH 3 ) 3 ), CF 3 (CH 2 ) 2 SiCI 3 , CF 3 (CF 2 ) 5 (CH 2 ) 2 SiCI 3 , CF 3 (CF 2 ) 7 (CH 2 ) 2 Si(OCH 3 ) 3 , CF 3 (CF 2 ) 5 (CH 2 )
  • the coupling agent may be present in the coating of the liquid repellent article in a suitable amount.
  • the coating comprises an amount of coupling agent in a range of from about 0.5 to 10% (w/v), or from about 1 to 5% (w/v).
  • the liquid repellent article comprises a substantially particle-free coating comprising at least one low surface energy polymer selected from the group consisting of low density polyethylene, poly(vinylidene fluoride), poly(vinylidene fluoride-co-hexafluoropropene), polytrifluoroethylene, polyvinyl fluoride, cyclic olefin copolymer, polydimethylsiloxane and poly(chlorotrifluoroethylene); and a coupling agent selected from the group consisting of fluorinated hydrocarbyl silane coupling agents and polyhedral oligomeric silsequioxane coupling agents.
  • low surface energy polymer selected from the group consisting of low density polyethylene, poly(vinylidene fluoride), poly(vinylidene fluoride-co-hexafluoropropene), polytrifluoroethylene, polyvinyl fluoride, cyclic olefin copolymer, polydimethylsilox
  • the substantially particle-free coating of the liquid repellent article also has a nano-rough topography.
  • the substantially particle-free coating has an average root mean square (RMS) roughness of at least 10 nm, at least 12 nm, or at least 15 nm.
  • the coating has a RMS roughness of between 10 to 200 nm, preferably between 15 to 100 nm.
  • Topography and roughness of the coating may be characterised using conventional techniques, such as atomic force microscopy (AFM).
  • the coating of the liquid repellent article may comprise optional additives, which may be used to confer additional properties to the coating and/or article or enable the aesthetic appearance (e.g. colour) of the coating and/or article to be modified.
  • optional additives may include but are not limited to antistatic agents, ultraviolet (UV) absorbers, stabilisers, antioxidants, lubricants, pigments or other opacifiers, dyes, plasticisers, suspending agents, anti-fouling agents, insect repellents, and the like.
  • the liquid repellent article comprises a fabric substrate and a substantially particle-free coating on the fabric substrate, wherein the coating comprises a low surface energy polymer and a coupling agent and has a nano-rough topography, and wherein the article is capable of repelling both water and oil.
  • Liquid repellent articles comprising a fabric substrate may be textile articles, such as clothing.
  • the substantially particle-free nano-rough coating is optically transparent, such that the aesthetic appearance of the underlying substrate is not substantially modified. This property may be advantageous when the coating is used in liquid repellent textile articles where it might be desired to preserve the appearance of the underlying fabric substrate. However, where desired, the appearance of the coating may be modified through the inclusion of appropriate optional additives. For example, pigments or dyes may be incorporated in the coating to modify its colour.
  • the substantially particle-free nano-rough coating does not modify the porosity of the underlying substrate or its permeability to air.
  • fabric substrates may be considered to be "breathable" due to the permeability of the fabric web to air and moisture. It has been found that the coating does not interfere with the breathability of the fabric and in some instances, may enhance breathability. Therefore, liquid repellent textile articles of the present invention may possess acceptable or favourable breathability. When the liquid repellent textile article is an article of clothing, breathability may aid a wearer's comfort.
  • the present invention also provides a process for the preparation of a liquid repellent article.
  • the process of the invention allows the article to be prepared in a simple and convenient manner, without the need to employ particles, such as microparticles and nanoparticles, to produce the rough topography that is normally required to impart liquid repellency.
  • a process for the preparation of a liquid repellent article comprising the steps of: applying a substantially particle-free coating composition comprising a low surface energy polymer, coupling agent, and a volatile carrier to a micro-rough surface of a substrate; and evaporating the volatile carrier from the coating composition applied on the substrate to thereby form a substantially particle-free coating on the substrate; wherein the coating comprises the low surface energy polymer and coupling agent and has a nano-rough topography, and wherein the article is capable of repelling both water and oil.
  • the process of the invention employs a substantially particle-free coating composition. It is an important feature of the invention that the coating composition be "substantially particle-free". As described herein, this generally means that the composition contains (on a w/v basis) less than 5%, less than 2%, less than 1 %, or less than 0.5% particles. Most preferably, the composition contains no particles.
  • the coating composition comprises a low surface energy polymer and a coupling agent.
  • the coating composition comprises at least one low surface energy polymer and at least one coupling agent and may, in some embodiments, comprise a plurality of low surface energy polymers and/or coupling agents. Suitable low surface energy polymers and coupling agents may be selected from any one of the low surface energy polymers and coupling agents described herein.
  • the coating composition comprises at least one low surface energy polymer having a surface free energy selected from the group consisting of no more than about 50 mN/m, no more than about 40 mN/m, and no more than about 35 mN/m at 20°C.
  • the polymer may be selected from the group consisting of polyolefins, halogenated polymers (such as fluoropolymers and perfluoropolymers), vinyl polymers, polysiloxanes, polyesters, polyurethanes, polycarbonates, copolymers thereof, and mixtures thereof.
  • polyolefins, fluoropolymers and perfluoropolymers may be preferred.
  • the coating composition may comprise a polymer selected from the group consisting of polyethylene (including low density polyethylene), polyisobutylene, cyclic olefin copolymers such as ethylene-norbornene copolymer, polystyrene, poly(a-methyl styrene), polyvinylchloride, poly(vinylidene fluoride), poly(vinylidene fluoride-co-hexafluoropropene), polyvinyl chloride), polyvinyl acetate), polytrifluoroethylene, poly(chlorotrifluoroethylene), poly(methyl acrylate), poly(ethyl acrylate), poly(methyl methacrylate), poly(ethyl methacrylate), poly(butyl methacrylate), poly(iso-butyl methacrylate), poly(hexyl methacrylate), poly(tetramethylene oxide), polydimethylsiloxane,
  • polyethylene including low density polyethylene
  • the coating composition comprises an amount of low surface energy polymer in a range of from about 0.2 to 10% (w/v), preferably from about 0.5 to 5% (w/v), more preferably about 1 to 3% (w/v).
  • the coating composition comprises at least one silane coupling agent.
  • suitable silane coupling agents are described herein.
  • Exemplary silane coupling agents comprise at least one non-hydrolysable group.
  • Non-hydrolysable groups present in the silane coupling agent may be low surface energy groups.
  • the silane coupling agent may comprise at least one non-hydrolysable group comprising a moiety selected from the group consisting of Ci to C20 alkyl, C2 to C30 alkenyl, C3 to do alkyl epoxy, C5 to C-20 aryl, Ci to C20 haloalkyl, C3 to C-20 cycloalkyl and C 2 to C 2 o cyanoalkyl. More preferably, the non- hydrolysable group comprises a moiety selected from the group consisting of Ci to C 2 o alkyl, C5 to C-10 aryl and Ci to C 20 haloalkyl (such as Ci to C 2 o perfluoroalkyl moiety).
  • the coating composition comprises at least one silane coupling agent selected from the group consisting of silane coupling agents of formula (I) or (II) as described herein, and mixtures thereof.
  • the coating composition may comprise an amount of coupling agent in a range of from about 0.5 to 10% (w/v), preferably from about 1 to 5% (w/v).
  • the coating composition comprises at least one low surface energy polymer selected from the group consisting of low density polyethylene, poly(vinylidene fluoride), poly(vinylidene fluoride-co- hexafluoropropene), polytrifluoroethylene, polyvinyl fluoride, cyclic olefin copolymer, polydimethylsiloxane and poly(chlorotrifluoroethylene); and a coupling agent selected from the group consisting of fluorinated hydrocarbyl silane coupling agents and polyhedral oligomeric silsequioxane coupling agents.
  • the coating composition may comprise a functionalised silane coupling agent as described herein.
  • Functionalised silane coupling agents may comprise one or more functional moieties selected from the group consisting of chromophores, luminescents, UV absorbing agents, antimicrobial agents, and antistatic agents.
  • the coating composition employed in the process of the invention also comprises a volatile carrier.
  • the volatile carrier is selected to be miscible with, and capable of dissolving the low surface energy polymer and coupling agent so that a homogenous coating composition is formed with little or no phase separation evident.
  • the coating composition is a liquid composition having a single phase. It is desirable that the volatile carrier be capable of evaporation under selected conditions once the coating composition has been applied to the surface of a substrate.
  • the volatile carrier comprises at least one volatile solvent.
  • the solvent is desirably one that is capable of dissolving the low surface energy polymer and coupling agent so as to provide a homogeneous solution.
  • the volatile carrier may comprise a mixture of two or more volatile solvents. In such embodiments it is preferred that the volatile solvents be compatible and miscible with one another.
  • volatile solvents may be employed in volatile carrier of the coating composition.
  • Preferred volatile solvents are capable of vaporising under ambient conditions.
  • Exemplary volatile solvents may have a saturated vapour pressure of at least 10 kPa at 20°C.
  • the volatile solvent may be selected from esters such as methyl acetate, ethyl acetate and butyl acetate; alcohols such as methanol, ethanol, propanol and butanol; glycols such as ethylene glycol; amides such as dimethylacetamide and N, N-dimethylformamide; dimethylsulfoxide; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl amyl ketone, cyclohexanone and N-methylpyrrolidinone; sulfolane; ethers such as diethyl ether, tetrahydrofuran, 2-methyl tetrahydrofuran and methyl tetrahydrofurfuryl ether; cyclic esters such as delta-valerolactone and gamma-valerolactone; fluorinated solvents such as perfluoro-2-butylt
  • Preferred volatile solvents may be selected from the group consisting of trichloroethane, trichloroethylene, methylene chloride, chloroform, carbon tetrachloride, tetrachlorethylene, methanol, ethanol, propanol, butanol, ethylene glycol, diethyl ether, ethyl acetate, acetone, N, N-dimethylformamide, and tetrahydrofuran, most preferably acetone.
  • the coating composition preferably comprises volatile carrier in an amount of from 75 to 99% (wt/v) of the total composition, preferably in an amount of from 80 to 98% (wt/v) of the total composition.
  • volatile carrier consists essentially of volatile solvent.
  • the volatile carrier may further comprise a propellant.
  • propellant is used herein to refer to materials that are aerosol spray propellants and generally have a boiling point lower than room temperature. Propellants may be used to provide for aerosol delivery of the coating composition. When present in the coating composition, the propellant is generally used in admixture with the volatile solvent and together with the solvent, forms the volatile carrier. Propellants are not considered as part of the volatile solvent in compositions of the invention and amounts based on the weight of the composition do not include propellants or materials having a boiling point below 25°C.
  • propellants such as hydrofluorocarbons, hydrocarbons, hydrochlorofluorocarbons, compressed gases, and their mixtures may be used in aerosol or spray application of the coating composition.
  • suitable propellants include ethane, propane, isobutene, dimethyl ether, HFO-1234ze, HFC- 134a, HFC-152a, and mixtures thereof.
  • the selection of propellant would be dependent on the solubility and miscibility of the propellant with the volatile solvent, polymer and coupling agent contained in the coating composition.
  • the coating composition may comprise optional additives.
  • the optional additives may include but are not limited to, antistatic agents, ultraviolet (UV) absorbers, stabilisers, antioxidants, lubricants, pigments or other opacifiers, dyes, plasticisers, anti-fouling agents, insect repellents, and the like. It is preferred that any optional additives also be soluble in the coating composition such that a homogeneous composition is maintained.
  • the low surface energy polymer and coupling agent are typically mixed with and dissolved in the volatile carrier. Any optional additives may also be dissolved in the volatile carrier. In one set of embodiments, it is preferred that the coating composition be a homogeneous liquid comprising the polymer, coupling agent and volatile carrier in a single phase.
  • the coating composition employed in the process of the invention consists of a low surface energy polymer, a coupling agent and a volatile carrier.
  • the coating composition consists of 0.5 to 10% (w/v) low surface energy polymer and 1 to 5% (w/v) coupling agent, with the balance of the composition being a volatile carrier comprising at least one volatile solvent.
  • the volatile carrier consists of volatile solvent.
  • the process may also comprise a step of providing a substantially particle-free coating composition comprising a low surface energy polymer, coupling agent, and a volatile carrier.
  • a process for the preparation of a liquid repellent article comprises the steps of: providing a substantially particle-free coating composition comprising a low surface energy polymer, coupling agent, and a volatile carrier; applying the coating composition to a micro-rough surface of a substrate; and evaporating the volatile carrier from the coating composition applied on the substrate to thereby form a substantially particle-free coating on the substrate; wherein the coating comprises the low surface energy polymer and coupling agent and has a nano-rough topography; and wherein the article is capable of repelling both water and oil.
  • the coating composition is applied to a substrate having a micro-rough surface.
  • the coating composition is applied to at least one surface of the substrate, but may be applied to a plurality of surfaces. It is requirement that the surface to which the coating composition is applied be a micro-rough surface.
  • the coating composition may be applied to the micro-rough surface of a substrate using conventional techniques, such as by dipping, spraying, brushing, padding, roll coating, curtain coating, or any combination of such techniques.
  • the desired method of application may depend on the type of substrate being coated.
  • the coating composition may be applied in a continuous manner, e.g. by coating a moving web or other substrate, to provide a roll or length of coated article.
  • the coating composition may be applied to a range of different substrates having a micro-rough surface.
  • a substrate having a micro-rough surface may be selected from the group consisting of non-porous substrates, porous substrates, woven substrates, non-woven substrates, braided substrates, fibres, yarns, films (including thin films) and foams.
  • the substrate may further be a flexible substrate.
  • the coating composition is applied to a surface of a porous substrate.
  • Porous substrates may be in the form of sheets, webs, foams and films. Examples of porous substrates include woven and non-woven fabrics and textiles, foam sheets and woven and non-woven papers.
  • the coating composition is applied to a surface of a textile substrate.
  • textile substrates include woven, non-woven, knitted or braided fabrics, fibres, filaments, yarns, etc.
  • a skilled person would understand that textile substrates would possess a surface having microscale profile features.
  • the substrate is a fabric substrate and the coating composition is applied to one or more surfaces of the fabric.
  • the fabric substrate may be a woven, non-woven, braided or knitted substrate and may be formed from synthetic or natural fibres, either alone or blended in any combination thereof.
  • the fabric substrate may comprise a fibre selected from the group consisting of cotton, cellulose, wool, cashmere, angora, silk, and combinations thereof.
  • the fabric substrate comprises cotton, wool or silk.
  • a coated substrate may be formed.
  • the volatile carrier is then removed from the applied coating composition by evaporation.
  • the volatile nature of the carrier (including solvents and other volatile compounds contained in the carrier) promotes its rapid evaporation.
  • evaporation of the volatile carrier may proceed under passive conditions at ambient temperature. In some embodiments, evaporation of the volatile carrier may be facilitated by exposing the coated substrate to elevated temperatures and/or by flowing air over the coated substrate. [0158] In one set of embodiments, the volatile carrier comprises or consists of at least one volatile solvent and the process of the invention comprises the step of evaporating the volatile solvent from the coating composition applied on the micro- rough surface of the substrate.
  • rapid evaporation means that a substantial proportion (such as least 50%, at least 60%, at least 70%, at least 80% or at least 90%) of the volatile solvent is removed from the coating composition applied on the substrate in a time period of less than 10 minutes, preferably less than 8 minutes, more preferably less than 5 minutes.
  • time period for solvent evaporation can vary, as it might depend on variables such as the thickness and surface area of the applied composition.
  • the coated substrate may be heated at an elevated temperature in a range of from about 40 to 200°C, preferably from about 60 to 140°C to facilitate evaporation of the volatile carrier.
  • the temperature may be selected based on the boiling point of the volatile solvent and/or the glass transition temperature (T g ) of the low surface energy polymer.
  • Heat may be applied by a range of devices, including convection or forced-air ovens, infrared heaters, or other sources of thermal energy.
  • Heating of the coated substrate may occur for a time period sufficient to result in evaporation of a desired quantity of volatile carrier and a skilled person would understand that the time period may depend on the selected temperature, the nature of the volatile carrier and the desired processing time.
  • heating of the coated substrate may occur for a time period selected from the group consisting of at least 5 minutes, at least 10 minutes, at least 15 minutes, at least 20 minutes and at least 30 minutes.
  • a time period selected from the group consisting of at least 5 minutes, at least 10 minutes, at least 15 minutes, at least 20 minutes and at least 30 minutes.
  • a combination of airflow and elevated temperature may be used to evaporate the volatile carrier.
  • the combination of airflow and elevated temperature may be employed concurrently or sequentially.
  • the coated substrate may be initially dried at room temperature in the presence of a flow of air to remove at least some of the volatile carrier and form a partially dried coated substrate.
  • the flow of air may be provided by a fan or similar device.
  • the partially dried coated substrate may then be heated at an elevated temperature to evaporate and remove the remaining quantity of volatile carrier.
  • the volatile carrier may be removed from the coated substrate at an elevated temperature in the presence of a flow of air, which may be provided by a fan- assisted oven or similar apparatus.
  • the process of the invention may further comprise the step of curing the substantially particle-free coating formed on the substrate.
  • the curing step is preferably carried out at elevated temperature. In some embodiments, the curing step is carried out at a temperature in a range of from about 40 to 200°C or in a range from about 60 to 160°C.
  • the curing step may facilitate covalent reactions of the coupling agent, either with itself or other components of the coating composition, or with the substrate, to crosslink the coupling agent or help with bonding of the coating to the substrate.
  • evaporation of the volatile carrier and curing of the coating may occur within a single vessel.
  • the coated substrate may be conveyed to an oven and heated in the oven at elevated temperature. The elevated temperature enables the volatile solvent to be removed by evaporation and also facilitates curing of the coupling agent.
  • the coating formed by the process of the invention is a low surface energy coating and comprises the low surface energy polymer and the coupling agent.
  • the coating formed by the process of the invention also has a nano-rough topography.
  • the nano-rough coating produced by the process of the invention has an average root mean square (RMS) roughness of at least 10 nm, at least 12 nm, or at least 15 nm. In some embodiments, the coating has a RMS roughness of between 10 to 200 nm, preferably between 15 to 100 nm.
  • RMS root mean square
  • a skilled person would be able to ascertain roughness and surface topography using conventional techniques such as atomic force microscopy (AFM).
  • a skilled person would be able to ascertain roughness and surface topography using conventional techniques such as atomic force microscopy (AFM).
  • AFM atomic force microscopy
  • the nano-rough topography of the coating is produced through rapid evaporation of the volatile carrier from the coating applied to the substrate.
  • the rapid evaporation of the volatile carrier is believed to result in fast solidification of the coating.
  • This rapid solidification locks the morphology of the polymer and coupling agent contained in the coating as a very limited time is available for the components of the coating to flatten and smooth out along the substrate surface. As a result, the coating acquires a nano-rough topography or nano-rough surface.
  • the liquid repellent properties of the article of the invention arise due to the combination of effects provided by the low surface energy nano-rough coating and the micro-rough substrate. It is believed that the nano-rough coating and the micro-rough substrate can operate in combination or synergistically to provide the advantages of the liquid repellent article that are observed. It is therefore an important feature of the invention that the liquid repellent article comprises a micro- rough substrate and a nano-rough low surface energy coating, where the coating is moreover substantially free of particles.
  • the substantially particle-free coating formed on the substrate has a surface free energy of no more than about 40 mN/m, no more than about 38 mN/m, no more than about 35 mN/m, or no more than about 30 mN/m, at 20°C.
  • the substantially particle-free coating comprises at least one low surface energy polymer and at least coupling agent.
  • the coupling agent is desirably a low surface energy coupling agent.
  • the low surface energy coupling agent may be silane coupling agent comprising a low surface energy group as described herein.
  • a low surface coupling agent may advantageously enable higher surface energy polymers to be used, provided that the combination of coupling agent and polymer together produce a coating having a low surface energy (e.g. a surface energy of no more than about 40 mN/m, no more than about 38 mN/m, no more than about 35 mN/m, or no more than about 30 mN/m, at 20°C).
  • silane coupling agents When silane coupling agents are used, it is believed that molecules of silane coupling agent can aggregate in the coating composition to form micelle-like structures so that the molecules can remain stable within the low surface energy polymer matrix.
  • the coupling agent comprises a hydrolysable group, condensation reactions between the hydrolysed molecules of silane agent may take place, which can stabilise the micellar structures because of the stronger interactions between silane molecules within the micelle.
  • the micellar aggregates may have some mobility within the polymer matrix, especially when the coating is at a temperature that is above the glass transition temperature (T g ) of the polymer.
  • T g glass transition temperature
  • the micelles may stably orientate at the air-solid interface of the polymer coating.
  • the micelles When orientated at the air-solid interface, the micelles may contribute to the nano-rough topography of the coating.
  • the surface energy of the micelle is lower than that of the polymer, the micelle at the air-solid interface of the coating can contribute to lower the overall surface free energy of the coating and hence enhance liquid repellency.
  • a liquid repellent article is able to be produced in a simple method, with no additional pre- or post-treatment required to control roughness and/or surface chemical composition.
  • the process of the invention enables amphiphobic articles and superamphiphobic articles to be prepared in a facile manner.
  • the present invention provides a liquid repellent article prepared by a process of any one of the embodiments described herein.
  • the liquid repellent article of one or more aspects of the invention is capable of repelling both water and oil.
  • Liquid repellent articles of the present invention are hydrophobic and provide a contact angle of at least about 90 degrees, at least 120 degrees, or at least 150 degrees, for water.
  • Liquid repellent articles of the present invention are also oleophobic and provide a contact angle of at least about 90 degrees, at least 120 degrees, or at least 150 degrees, for oil.
  • the liquid repellent article may provide approximately the same liquid contact angle or different liquid contact angles for water and oil.
  • the liquid repellent article may provide a contact angle of at least 150 degrees for water and a contact angle of at least 120 degrees for oil.
  • the article remains hydrophobic and oleophobic and able to repel both water and oil.
  • An oil may be a hydrocarbon compound or lipid substance that is liquid at room temperature.
  • oils have a low surface tension, such as for example, a surface tension of 35 mN/m or less at 20°C.
  • the liquid repellent article is capable of repelling other solvents and liquids in addition to water and oil.
  • liquid repellent articles of one or more embodiments of the invention provide a liquid contact angle of at least about 90 degrees, at least 120 degrees, or at least 150 degrees, for a liquid in contact with the article.
  • a liquid repellent article of one or more aspects of the invention advantageously exhibits combined hydrophobic and oleophobic properties and may in some embodiments exhibit superhydrophobic and superoleophobic properties where water and oil display contact angles (CAs) at least 120 degrees or at least 150 degrees when in contact with the article.
  • CAs water and oil display contact angles
  • the articles in accordance with the invention may therefore be regarded as superamphiphobic.
  • a liquid contact angle above 150 degrees allows liquids to form nearly spherical shapes on coated substrate surfaces. Such contact angles can maintained for a long period of time on the coated surfaces.
  • the liquid contact angle is often determined by measuring the liquid-solid angle of a liquid drop of given volume with a horizontally laid surface. A skilled person would appreciate that high liquid contact angles (i.e. 90 degrees or higher) are indicative of highly effective liquid repellent surfaces.
  • the desired liquid contact angle is preferably exhibited by both water and oil when in contact with a liquid repellent article of embodiments described herein.
  • liquid repellent articles of one or more aspects of the present invention are capable of repelling low surface tension liquids.
  • Low surface tension liquids may have a surface tension of 35 mN/m or less at 20°C.
  • the liquid having a surface of 35 mN/m or less exhibits a liquid contact angle of at least 90 degrees, at least 120 degrees or at least 150 degrees, when in contact with a liquid repellent article of the present invention.
  • Low surface tension liquids may include organic solvent liquids such as hydrocarbons including ethanol and hexadecane and halohydrocarbons such as chloroform.
  • a liquid repellent article of one or more aspects of the invention also exhibits a low sliding angle (SA).
  • SA low sliding angle
  • the sliding angle is a measure of the critical angle at which a droplet of liquid (such as water or oil) will slide down an inclined plane.
  • the sliding angle may be indicative of the relative liquid repellency of the article.
  • the liquid repellent article may exhibit a liquid sliding angle selected from the group consisting of no more than about 35 degrees, no than about 20 degrees, no more than about 15 degrees, and no more than about 10 degrees.
  • the present invention provides a liquid repellent textile article comprising a fabric substrate and a substantially particle-free low surface energy nano-rough coating on a surface of the fabric substrate.
  • the present invention provides a liquid repellent textile article comprising a fabric substrate and a substantially particle-free coating on a surface of the fabric substrate, wherein the coating comprises a low surface energy polymer and a coupling agent and has a nano-rough topography.
  • the fabric substrate employed in the liquid repellent textile article would comprise a micro-rough surface.
  • the low surface energy polymer may be at least one selected from those described herein.
  • the coupling agent may be a silane coupling agent. Suitable silane coupling agents may be selected from any one of those described herein.
  • the fabric substrate of the textile article may be a woven, non-woven, braided or knitted fabric formed from synthetic or natural fibres, either alone or blended in any combination thereof.
  • the fabric substrate may comprise a fibre selected from the group consisting of cotton, cellulose, wool, cashmere, angora, silk, and combinations thereof.
  • the fabric substrate comprises cotton, wool or silk.
  • the present invention also provides a method of preparing a liquid repellent textile article comprising the steps of: applying a substantially particle-free coating composition comprising a low surface energy polymer, coupling agent, and a volatile carrier to a surface of a fabric substrate; and evaporating the volatile carrier from the applied coating composition to thereby form a substantially particle-free coating on the fabric substrate; wherein the coating comprises the low surface energy polymer and coupling agent and has a nano-rough topography, and wherein the textile article is capable of repelling both water and oil.
  • the coating composition may be applied to the fabric substrate by means of spray, brush, roll coating, curtain coating, or any combination of these application techniques.
  • the liquid repellent textile article provides a contact angle selected from the group consisting of at least about 90 degrees, at least about 120 degrees, or at least 150 degrees, for water and oil in contact with the article.
  • the liquid repellent textile article is hydrophobic and provides a contact angle selected from the group consisting of at least about 90 degrees, at least about 120 degrees, or at least 150 degrees, for water in contact with the article.
  • the liquid repellent textile article is oleophobic and provides a contact angle selected from the group consisting of at least about 90 degrees, at least about 120 degrees, or at least 150 degrees, for oil in contact with the article.
  • liquid repellent article produced of one or more aspects of the present invention possesses a number of advantageous properties as discussed below.
  • the liquid repellent article of the invention is durable.
  • the article is able to resist physical and chemical damage without loss of its liquid repellent properties.
  • the liquid repellent article is able to repel corrosive chemicals such as strong acids and strong alkali, which enables the article to resist chemical damage.
  • the article is also capable of withstanding repeated physical abrasion, rubbing or mechanical stress.
  • a liquid repellent article of one or more aspects of the invention is capable of withstanding 10,000 cycles of abrasion, when tested according to ASTM D4966-98. This test indicates that the article is able to maintain the ability to repel water and oil after 10,000 cycles of abrasion.
  • the liquid repellent article of the invention When damaged, the liquid repellent article of the invention is capable of undergoing self-healing to repair the damage. In some embodiments, repeated self- healing is possible. Self-healing may be possible as the coating on the article may be capable of repairing itself after damage. Damage may occur by chemical means (e.g. by radiation or oxidation induced damage) or by physical means (e.g. by abrasion, cutting or short time burning). Such damage may introduce high surface energy groups in the coating and article, which can lead to a loss of liquid repellency.
  • chemical means e.g. by radiation or oxidation induced damage
  • physical means e.g. by abrasion, cutting or short time burning
  • the ability of the liquid repellent article to self-heal and regain liquid repellency may be due to the ability of the components in the coating of the article to reorientate in the coating to cover any high surface energy groups that may be introduced as a result of damage.
  • the low surface energy polymer may be capable of rotating in the coating in order to cover and conceal high surface energy groups.
  • micellar structures comprising low surface energy coupling agent may migrate to the air-solid interface of the coating to conceal high surface energy groups.
  • the liquid repellent article is also able to withstand repeated washing. This property is advantageous for textile articles which are generally washed repeatedly in order to remove stains and soils.
  • a liquid repellent article of one or more aspects of the invention is capable of withstanding at least 100 washing cycles, when tested according to AATCC Test Method 61 -2006. In some embodiments, the repellent article is capable of withstanding at least 200, at least 400, or at least 600 washing cycles, when tested according to AATCC Test Method 61 -2006. This test indicates that articles of the invention, such as liquid repellent textile articles, are able to maintain their ability to repel water and oil despite repeated washing cycles.
  • the liquid repellent article is also resistant to high temperature treatment and may be exposed to high temperature, such as immersion in boiling water, without suffering from a significant loss of liquid repellency.
  • Washing durability of a coated fabric was examined by reference to a standard method for testing washing fastness of fabrics (AATCC Test Method 61-2006 test No 2A).
  • the test was performed using a standard laundering machine (Fong, Fong's National Engineering CO. LTD, Hong Kong, China) equipped with 500 mL (75 mm ⁇ 75 mm) stainless-steel lever-lock canisters.
  • the coated fabric sample (size, 50 mm *150 mm) was laundered in a 150 mL aqueous solution containing 0.15% (w/w) AATCC standard reference detergent WOB.
  • the temperature was controlled at 49 °C, and the stirring speed was 40 ⁇ 2 rpm.
  • Abrasion resistance of a coated fabric was tested using the Martindale method according to ASTM D4966. The test was performed under a commercial Martindale abrasion tester (I.D.M Instrument Design & Maintenance). In our experiment, the untreated wool fabric was used as abradant, 12 kPa of pressure was employed, which is often used to evaluate the coated fabrics for heavy duty upholstery usages.
  • G 0.10MC 3 (2)
  • G (mg cm) is the flexural rigidity of the fabric sample
  • M (mg cm “2 ) is the areal density of the fabric.
  • C (cm) and g (cm) are bending length and fabric thickness, respectively.
  • the fabric thickness was measured using a thickness tester (MESDAN micrometer). The measurements were carried out in both warp and weft directions.
  • 1 H, 1 H,2H,2H-perfluorodecyltriethoxysilane (C 16 H 19 Fi 7 O 3 Si) (FAS coupling agent), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and acetone were obtained from Aldrich and used as received.
  • the coating composition was prepared by mixing PVDF-HFP (1.0 g) and FAS (0.75 ml_) in acetone (50 ml_) and stirring with a magnetic stirring bar for 30 minutes at 50 °C to get a homogenous solution.
  • Figure 2 shows the chemical structure of the materials employed in the coating composition and the procedure to prepare the coating on the fabric substrate.
  • Acetone is a high volatile solvent, and under a high temperature with high speed fan, it evaporated rapidly, thus, a nano-rough -structure of PVDF-HFP polymer layer was formed.
  • Surface roughness measured by AFM imaging indicated that the root mean square (RMS) roughness of the fabric changed from 9.82 nm to 15.1 nm after coating treatment, confirming that a rough coating layer can be formed after the rapid evaporation of the solvent.
  • RMS root mean square
  • the coated fabric is able to repel a range of liquids, as it was observed that water, olive oil, hexadecane and ethanol formed spherical droplets when in contact with the coated fabric. In comparison, these liquids spread out when in contact with a comparative uncoated fabric due to wetting effects.
  • the coated fabric provided liquid contact angles (CA) of 162°, 156°, 154° and 146°, and sliding angles (SA) of 4°, 15°, 22° and 35°, to water, olive oil, hexadecane and ethanol, respectively. All CAs had little change with time. For ethanol, the droplet evaporated off in 10 minutes, while water drop evaporated completely in 40 minutes.
  • Figure 5 shows the dependency of CA and SA on the surface tension of liquids. It is clearly indicated that the coated fabric is capable of repelling liquids with a surface tension greater than 22.3 mN/m.
  • Washing is an essential treatment for the practical uses of fabrics. During washing, the fabric undergoes mechanical stresses in addition to chemical agents. The synergistic effect of chemical and physical actions accelerates the detachment of coating layer on fiber substrate.
  • the washing durability of the coated fabric was evaluated by reference of a standard machine laundry process. The coated fabric can withstand at least 600 cycles of machine wash without losing its liquid repellency. After 600 washing cycles, the SA of the coated fabric just had a slight increase, while the CA maintained unchanged.
  • the treated fabric can withstand boiling treatment in water.
  • One hour of boiling in water did not affect the liquid repellency of the coated fabric and the CA for all the liquids studied had no change.
  • the boiling treatment led to a slight increase in SA.
  • the SA increased to 6°, 21 °, 27° and 43° for water, olive oil, hexadecane and ethanol, respectively.
  • the PVDF-HFP/FAS coating has a self-healing property to recover its liquid repellent properties after chemical damage.
  • the coated fabric was deliberately treated with a vacuum plasma using air as gas source.
  • the plasma treatment introduces polar functional groups such as oxygen, hydroxyl and carboxylic acid groups to the coating surface.
  • Such a plasma treatment made the coating surface both hydrophilic and oleophilic with a CA of 0°.
  • the plasma treated fabric was heated at 130° for 5 minutes, the liquid repellency was restored.
  • the treated fabric was able to be repeatedly damaged and repaired and retained its liquid repellent properties even after 60 cycles of plasma and self-healing.
  • Table 1 shows the effect of the coating treatment on fabric properties.
  • the coating had almost no influence on the air permeability, but slightly affected the fabric rigidity and the permeability to moisture. For colored fabrics, it was hard to distinguish the color change after coating treatment.
  • the color difference data ( ⁇ ) was less than 1 (Table 1 ).
  • the ⁇ value of 1 is the smallest color difference that human eye can distinguish, and any materials of ⁇ less than 1 .0 is indistinguishable.
  • To evaluate the coating transparency a dense PVDF-HFP/FAS film was prepared on a glass slide. The coated glass slide looked transparent. The transmission spectrum also confirmed that the PVDF-HFP/FAS layer was highly transparent, hence did not influence the fabric original color. Table 1 Effect of coating treatment on fabric properties
  • Polystyrene (PS) solution was prepared by dissolving PS (2.5 g) in chloroform (100 ml). After 30 minutes of magnetic stirring, a homogeneous solution was formed. Tridecafluorooctyl triethoxysilane was then added into the polymer solution with magnetic stirring for 30 minutes. Fabric substrates were immersed into the coating solution for 1 minute. After squeezing to remove excess solution, the coated fabrics were dried at 1 10 °C for 30 minutes.
  • polyester fabric plain weave, 168g/m2
  • cotton fabric plain weave, 146g/m2
  • wool fabric plain weave, 196 g/m2
  • electrospun polyacrylonitrile (PAN) nanofibres mat average fibre diameter 370 ⁇ 22 nm, thickness 0.35 ⁇ 0.01 mm.
  • PAN polyacrylonitrile
  • PEEK polyetheretherketone
  • PC Polycarbonate
  • 5g was dissolved in 100 ml methylene chloride.
  • 2 ml phenyl triethoxysilane silane was then added in the as-prepared PC solution under magnetic stirring to get a homogeneous coating solution.
  • the solution can be applied onto the substrates directly by different coating techniques, such as spraying, padding and dip-coating.
  • the coated fabric substrates were further dried at 130 °C for 10 minutes. All the coated substrates showed superamphiphobic surface.
  • the CAs of the coated wool fabric are 166° to water, 158° to cooking oil and 150° to hexadecane, respectively.
  • Polyisobutylene (PIB) 2.5 g was dissolved in 100 ml dichloromethane under stirring for 2 hours to get a homogeneous polymer solution .
  • octyl triethoxysilane was then added in the coating solution with continuous stirring for 30 minutes to form a superamphiphobic coating solution. Dip- coating the fabric substrates in the solution and the coated substrates were finally heated at 130 °C for 1 hour. After coating, the fabric showed high liquid repellency to both water and oil liquid.
  • Low density polyethylene (LDPE) 2 g was dissolved in 100 ml xylene, the solution was mixed with (iso-butyl)-POSS heptyl silane, and stirred intensively at room temperature for 3 hours to produce homogeneous coating solution. Brush painting was used to apply the coating solution onto the substrates. The coated substrates were then dried at 130 °C for 20 minutes. After coating, the porous film turned superamphiphobic, with CAs of 155° and 150° to water and soybean oil.
  • LDPE low density polyethylene
  • the solution can be applied onto the substrates directly by different coating techniques, such as spraying, padding and dip-coating.
  • the coated fabric substrates were further dried at 120 °C for 30 minutes.
  • the coated substrates showed super-repellent to water and oils.
  • the CAs of the coated polyester fabric are 166° to water and 152° to cooking coil.

Abstract

L'invention concerne de manière générale un article hydrofuge. Elle concerne en particulier un article hydrofuge comprenant un substrat micro-rugueux; et un revêtement nano-rugueux à faible énergie de surface, sensiblement exempt de particules, disposé sur le substrat. L'invention concerne également un procédé de préparation de l'article hydrofuge.
PCT/AU2015/000585 2014-09-25 2015-09-24 Article hydrofuge et son procédé de préparation WO2016044880A1 (fr)

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WO2019231755A1 (fr) * 2018-05-29 2019-12-05 Sonoco Development, Inc. Revêtement et encre de barrière de protection
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Cited By (12)

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Publication number Priority date Publication date Assignee Title
WO2018031356A1 (fr) * 2016-08-06 2018-02-15 Hrl Laboratories, Llc Revêtements combinant des constituants absorbant les huiles et oléophobes, permettant d'augmenter la résistance aux taches
CN109563359A (zh) * 2016-08-06 2019-04-02 Hrl实验室有限责任公司 用于增加的耐污性的结合吸油和斥油组分的涂层
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CN109563359B (zh) * 2016-08-06 2021-07-23 Hrl实验室有限责任公司 用于增加的耐污性的结合吸油和斥油组分的涂层
US11203695B2 (en) * 2016-09-06 2021-12-21 The Regents Of The University Of Michigan Durable superhydrophobic surfaces
WO2019231755A1 (fr) * 2018-05-29 2019-12-05 Sonoco Development, Inc. Revêtement et encre de barrière de protection
US10941523B2 (en) 2018-05-29 2021-03-09 Sonoco Development, Inc. Protective barrier coating and ink
US11499270B2 (en) 2018-05-29 2022-11-15 Sonoco Development, Inc. Protective barrier coating for tubes and cores
CN110734525A (zh) * 2018-07-18 2020-01-31 浙江省化工研究院有限公司 一种含氟笼型倍半硅氧烷改性聚三氟氯乙烯树脂
CN110734525B (zh) * 2018-07-18 2022-07-01 浙江省化工研究院有限公司 一种含氟笼型倍半硅氧烷改性聚三氟氯乙烯树脂
CN111825984A (zh) * 2020-06-30 2020-10-27 苏州天澜生物材料科技有限公司 一种固液填充的低表面能光滑功能材料及其制备方法
WO2022000944A1 (fr) * 2020-06-30 2022-01-06 苏州天澜生物材料科技有限公司 Matériau fonctionnel lisse à faible énergie de surface chargé de solide-liquide et procédé de préparation associé

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