WO2025148015A1

WO2025148015A1 - Fluorine-free omniphobic coating

Info

Publication number: WO2025148015A1
Application number: PCT/CN2024/072039
Authority: WO
Inventors: Hau To Wong; Alex Chan; Lee Ying Yu; Kun Wang
Original assignee: Hong Kong Research Institute of Textiles and Apparel Ltd
Current assignee: Hong Kong Research Institute of Textiles and Apparel Ltd
Priority date: 2024-01-12
Filing date: 2024-01-12
Publication date: 2025-07-17
Anticipated expiration: 2026-07-12

Abstract

A fluorine-free omniphobic coating composite useful for providing water and oil repellency to a textile, coated textiles including the same, and a method of preparation thereof. The omniphobic coating composite can include a water-repellant layer, an oil-repellant layer, and optionally one or more adhesion promotion layers, wherein the water-repellant layer includes at least one hydrophobic additive, the oil-repellant layer includes at least one oleophobic additive, and the one or more adhesion promotion layers include one or more crosslinking agents, wherein the omniphobic coating composite is fluorine-free.

Description

FLUORINE-FREE OMNIPHOBIC COATING

TECHNICAL FIELD

The present disclosure relates to a fluorine-free omniphobic coating composite useful for imparting water-repellant and oil-repellant properties to a textile, coated textiles comprising the omniphobic coating composite, and methods of preparation thereof.

BACKGROUND

Global textile chemicals market size is anticipated to grow at a rate of 4.7%from 2022 to 2030. Chemicals for water and oil repellent products are one of the boosters. Durable water and oil repellent surface finishes bring value-added functions to fabric materials and are significant to the textile industry.

To date, the most effective liquid repellents on textile materials are all made of C8 based fluorochemicals (

Table 1) , which are able to lower the surface energies of the materials, prevent liquid droplets from wetting and staying on the material surface when it is tilted.

Table 1: C8 based fluorochemicals for water and oil repellents.

However, the products of C8 fluorochemicals consist of two side products, which are perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) . They are considered as “Persistent, Bioaccumulative and Toxic” , “Toxic to Reproduction” and “Persistent Organic Pollutant” . PFOA is also classified as “possibly carcinogenic to humans” by IARC, a specialized cancer agency of the WHO. Uses of chemicals, containing PFOA and PFOS, become restricted in major markets. Classifications of PFOA are as below:

Table 2: Classification 1272/2008 (CLP) of PFOA.

To address this problem, products based on C6 fluorochemicals are alternatives to C8 fluorochemicals. C6 fluorochemicals share the same working principles as C8 fluorochemicals, by lowering the surface energies of material surfaces.

Table 3: Example of C6 fluorochemicals,

The side product of C6 fluorochemicals is called PFHA (perfluoroheptanoic acid) , which is 40 times less bioaccumulative than PFOA. Although it is more environmental-friendly than PFOA, it is still considered as “Persistent, Bioaccumulative and Toxic” and “Toxic to Reproduction” . Proposals have been made to restrict the use of C6 fluorochemicals in certain applications, including textiles. Therefore, development of an effective fluorine-free oil repellent coating is highly demanded.

Fluorine-free water-repellent surface finishes have achieved further advancement compared to oil-repellent surface finishes partly due to market demand. Another major reason is that water generally has high surface tension compared with oils as shown in

Table 4. To achieve water and oil repellency on a surface, the surface energy of the material must be significantly lower than the surface tension of water and oils. This makes it easier to fabricate surfaces that are highly repellent towards water than towards oils.

Table 4: Surface tensions of common liquids and polymers

At present, there are no examples of fluorine-free surface finish, which is an effective repellent towards oil on textile fabrics.

Siloxanes are polymers that have a silicone-oxygen-silicone backbone that is highly stable. The most commonly used siloxane polymer is poly (dimethylsiloxane) (PDMS) and its derivatives. The surface energy of PDMS typically ranges 19-20 mN/m, which is significantly lower than the surface tensions of water and oils as shown above. Thus, PDMS can be used for modifying fabric surfaces so that water and oils do not stick and stay on the fabric surfaces.

For example, siloxane was used as a water-repellent on cotton fabric in CN104911907A. A co-polymer of acrylic acid ester and organopolysiloxane was synthesized and imparted on fibers. The fibers exhibit water-repellent in JP2017222967A and JP2017218713A. CN108385375A, CN111454430A, WO2021235334 A1, WO2022171581A1 are also examples, in which siloxanes were used as the active water-repellent agent.

Polysaccharides are typically highly hydrophilic due to the large number of polar substituents. Examples, such as alginates and celluloses, have been demonstrated to reduce the degree of oil wetting on their surfaces.

In the context of the above, there remains a need for an effective and generic surface modification method on common fabrics for oil-and water-repellent without the use of fluorochemicals. Therefore, there is a need to develop a fluorine-free surface modification method for textiles.

SUMMARY

Provided herein is a fluorine-free surface modification method for textile fabrics, that can enhance the oil-repellent and water-repellent properties without using fluorochemicals. With fabric surface modification, the fabric repels water and oil to a greater extent, and these properties can be durable. Thus, the oil-repellent and water-repellent properties can be maintained after multiple cycle (s) of washing, drying and re-use.

In a first aspect, provided herein is an omniphobic coating composite comprising a water-repellant layer, an oil-repellant layer, and optionally one or more adhesion promotion layers, wherein the water-repellant layer comprises at least one hydrophobic additive, the oil-repellant layer comprises at least one oleophobic additive, and the one or more adhesion promotion layers comprise one or more crosslinking agents, wherein the omniphobic coating composite is fluorine-free.

In certain embodiments, the at least one oleophobic additive is selected from the group consisting of a polysaccharide, a polyvinyl alcohol, a siloxane, a silane, and a polyacrylic acid.

In certain embodiments, the polysaccharide comprises chitosan, fully deacetylated chitosan, partially deacetylated chitosan, a metal alginate, a starch, or a mixture thereof.

In certain embodiments, the at least one hydrophobic additive comprises a siloxane, a silane, a hydrophobic binder, or a mixture thereof.

In certain embodiments, the siloxane comprises a poly (dialkylsiloxane) , a poly (alkylhydrogensiloxane) , a poly (dialkylsiloxane-co-alkyllhydrosiloxane) , or a mixture thereof; the silane comprises at least one hydrolyzable group and at least one C₁₀-C₂₀ alkyl, wherein the hydrolysable group is selected from the group consisting of halide and alkoxide; and the hydrophobic binder comprises an acrylic copolymer.

In certain embodiments, the oil-repellant layer further comprises a binder.

In certain embodiments, the water-repellant layer further comprises a crosslinking agent.

In certain embodiments, the crosslinking agent is a polyisocyanate, a polycarbodiimide, a polyaziridine, a silane, a calcium salt, an aluminum salt, or a mixture thereof.

In certain embodiments, the one or more crosslinking agent comprises a polyisocyanate, a polycarbodiimide, a polyaziridine, a silane, a calcium salt, an aluminum salt, or a mixture thereof.

In certain embodiments, the one or more crosslinking agent is calcium chloride.

In certain embodiments, the at least one oleophobic additive comprises a polysaccharide, a polyvinyl alcohol, a partially hydrolyzed polyvinyl acetate, a poly (dialkylsiloxane) , a poly (alkylhydrogensiloxane) , a poly (dialkylsiloxane-co-alkyllhydrosiloxane) , or a polyacrylic acid; the at least one hydrophobic additive comprises a poly (dialkylsiloxane) , a poly (alkylhydrogensiloxane) , a poly (dialkylsiloxane-co-alkyllhydrosiloxane) , a silane, a hydrophobic binder, or a mixture thereof; and the one or more crosslinking agents comprise a polyisocyanate, a polycarbodiimide, a polyaziridine, a silane, a calcium salt, an aluminum salt, or a mixture thereof.

In certain embodiments, the at least one oleophobic additive comprises a poly (dialkylsiloxane) , a poly (alkylhydrogensiloxane) , a poly (dialkylsiloxane-co-alkyllhydrosiloxane) , sodium alginate, or a mixture thereof; the at least one hydrophobic additive comprises a poly (dialkylsiloxane) , a poly (alkylhydrogensiloxane) , a poly (dialkylsiloxane-co-alkyllhydrosiloxane) , an acrylic copolymer, wherein the acrylic copolymer comprises one or more repeating units selected from the group consisting of acrylate, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, methacrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, ethacrylate, methyl ethacrylate, ethyl ethacrylate, propyl ethacrylate, butyl ethacrylate, acrylic acid, ethylene monomers, or combinations or blends thereof; and the one or more crosslinking agents comprise calcium chloride.

In certain embodiments, the water-repellant layer further comprises calcium chloride.

In a second aspect, provided herein is a coated textile comprising the omniphobic coating composite described herein disposed on at least one surface of a textile.

In certain embodiments, the oil-repellant layer is disposed between the textile and the water-repellant layer.

In a third aspect, provided herein is a method of preparing the coated described herein, the method comprising:

(a) depositing a water-repellant layer precursor solution comprising the at least one hydrophobic additive thereby forming a water-repellant layer precursor coating and curing the water-repellant layer precursor thereby forming the water-repellant layer;

(b) depositing an oil-repellant layer precursor solution comprising the at least one oleophobic additive thereby forming an oil-repellant layer precursor coating and curing the oil-repellant layer precursor thereby forming the oil-repellant layer;

(c) optionally depositing an adhesion promotion layer precursor solution comprising one or more crosslinking agents thereby forming an adhesion promotion layer precursor coating; and curing the adhesion promotion layer precursor coating thereby forming an adhesion promotion layer; and

(d) optionally repeating step (c) thereby forming the one or more adhesion promotion layers, wherein (a) , (b) , optionally (c) , and optionally (d) are conducted on or more surfaces of the textile in any order thereby forming the preparing the coated textile.

In certain embodiments, the method comprises:

(a) depositing the adhesion promotion layer precursor solution on a surface of the textile thereby forming the adhesion promotion layer precursor coating the surface of the textile;

(b) curing the adhesion promotion layer precursor coating thereby forming the adhesion promotion layer;

(c) depositing the oil-repellant layer precursor solution on a surface of the adhesion promotion layer thereby forming the oil-repellant layer precursor coating;

(d) curing the oil-repellant layer precursor coating thereby forming the oil-repellant layer;

(e) depositing the water-repellant layer precursor solution on a surface of the oil-repellant layer thereby forming the water-repellant layer precursor coating; and

(f) curing the water-repellant layer precursor coating thereby forming the coated textile.

In certain embodiments, the water-repellant layer precursor solution further comprises a crosslinking agent.

18. In certain embodiments, each curing step independently comprises heating at 40℃ –200℃.

19. In certain embodiments, each of the water-repellant layer precursor solution, the oil-repellant layer precursor solution, and optionally the adhesion promotion layer precursor solution comprise water.

BRIEF DESCRIPTION OF THE DRAWING

The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated and understood by reference to the following detailed description, when taken in conjunction with the accompanying drawing.

The Figure illustrates a cross-sectional view of the coated textile comprising the omniphobic coating composite in accordance with certain embodiments described herein.

DESCRIPTION OF THE INVENTION

Definitions

Throughout the present disclosure, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising" , will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers. It is also noted that in this disclosure and particularly in the claims and/or paragraphs, terms such as “comprises” , “comprised” , “comprising” and the like can have the meaning attributed to it in U.S. Patent law; e.g., they can mean “includes” , “included” , “including” , and the like; and that terms such as “consisting essentially of” and “consists essentially of” have the meaning ascribed to them in U.S. Patent law, e.g., they allow for elements not explicitly recited, but exclude elements that are found in the prior art or that affect a basic or novel characteristic of the present invention.

Furthermore, throughout the present disclosure and claims, unless the context requires otherwise, the word “include” or variations such as “includes” or “including” , will be understood to imply the inclusion of a stated integer or group of integers, but not the exclusion of any other integer or group of integers.

The use of the singular herein includes the plural (and vice versa) unless specifically stated otherwise. In addition, where the use of the term "about" is before a quantitative value, the present teachings also include the specific quantitative value itself, unless specifically stated otherwise. As used herein, the term "about" refers to a ±10%, ±7%, ±5%, ±3%, ±1%, or ±0%variation from the nominal value unless otherwise indicated or inferred.

As used herein, a "polymeric compound" (or "polymer" ) refers to a molecule including a plurality of one or more repeating units connected by covalent chemical bonds. A polymeric compound can be represented by General Formula I:
*- (- (Ma) _x- (Mb) _y-) _z*

General Formula I

wherein each Ma and Mb is a repeating unit or monomer. The polymeric compound can have only one type of repeating unit as well as two or more types of different repeating units. When a polymeric compound has only one type of repeating unit, it can be referred to as a homopolymer. When a polymeric compound has two or more types of different repeating units, the term "copolymer" or "copolymeric compound" can be used instead. For example, a copolymeric compound can include repeating units where Ma and Mb represent two different repeating units. Unless specified otherwise, the assembly of the repeating units in the copolymer can be head-to-tail, head-to-head, or tail-to-tail. In addition, unless specified otherwise, the copolymer can be a random copolymer, an alternating copolymer, or a block copolymer. For example, General Formula I can be used to represent a copolymer of Ma and Mb having x mole fraction of Ma and y mole fraction of Mb in the copolymer, where the manner in which comonomers Ma and Mb is repeated can be alternating, random, regiorandom, regioregular, or in blocks, with up to z comonomers present. In addition to its composition, a polymeric compound can be further characterized by its degree of polymerization (n) and molar mass (e.g., number average molecular weight (M) and/or weight average molecular weight (Mw) depending on the measuring technique (s) ) . The polymers described herein can exist in numerous stereochemical configurations, such as isotactic, syndiotactic, atactic, or a combination thereof.

The term "alkyl" is art-recognized, and includes saturated aliphatic groups, including straight-chain alkyl groups, branched-chain alkyl groups, cycloalkyl (alicyclic) groups, alkyl substituted cycloalkyl groups, and cycloalkyl substituted alkyl groups. In certain embodiments, a straight chain or branched chain alkyl has about 30 or fewer carbon atoms in its backbone (e.g., C₁-C₃₀ for straight chain, C₃-C₃₀ for branched chain) , and alternatively, about 20 or fewer. Likewise, cycloalkyls have from about 3 to about 10 carbon atoms in their ring structure, and alternatively about 5, 6 or 7 carbons in the ring structure.

The term “omniphobic” as used herein refers to a material or compound that exhibits both hydrophobic (low wettability for water and other polar liquids) and oleophobic (low wettability for low surface tension and nonpolar liquids) properties.

Provided herein is an omniphobic coating composite comprising a water-repellant layer, an oil-repellant layer, and optionally one or more adhesion promotion layers, wherein the water-repellant layer comprises at least one hydrophobic additive, the oil-repellant layer comprises at least one oleophobic additive, and the one or more adhesion promotion layers comprise one or more crosslinking agents, wherein the omniphobic coating composite is fluorine-free.

The oil-repellant layer primarily acts as a barrier to prevent oils (e.g., Kaydol oil, mineral oil, paraffin oil, n-hexadecane, n-tetradecane, n-dodecane, n-decane, n-octane, n-heptane, corn oil) and also aqueous liquids (including but not limited to water, alcohol, and mixtures thereof) from wicking or penetrating into fabric.

The oil-repellant layer can comprise 1, 2, 3, 4, 5, or more oleophobic additives. In certain embodiments, the at least one oleophobic additive is selected from the group consisting of a polysaccharide, a polyvinyl alcohol, a partially hydrolyzed polyvinyl acetate, a siloxane selected from the group consisting of poly (dialkylsiloxane) , a poly (alkylhydrogensiloxane) and poly (dialkylsiloxane-co-alkyllhydrosiloxane) , a silane and a polyacrylic acid. The one more oleophobic additives can be present in the oil-repellant layer at a concentration from 0.1-55%wt/wt, 0.1-54%wt/wt, 0.1-53%wt/wt, 0.1-52%wt/wt, 0.1-45%wt/wt, 0.1-40%wt/wt, 0.1-35%wt/wt, 0.1-30%wt/wt, 0.1-20%wt/wt, 0.1-15%wt/wt, 0.1-10%wt/wt, 0.1-9%wt/wt, 0.1-8%wt/wt, 0.1-7%wt/wt, 0.1-6%wt/wt, 0.1-5%wt/wt, 0.1-4%wt/wt, 0.1-3%wt/wt, 0.1-2%wt/wt, 0.1-1%wt/wt, 0.05-1%wt/wt, 0.05-2%wt/wt, 5-10%wt/wt, 6-10%wt/wt, 7-10%wt/wt, 8-10%wt/wt, 9-10%wt/wt, 5-9%wt/wt, 5-8%wt/wt, 5-7%wt/wt, 5-6%wt/wt, 1-5%wt/wt, 2-5%wt/wt, 3-5%wt/wt, 3-4%wt/wt, 1-4%wt/wt, 1-3%wt/wt, or 1-2%wt/wt. In certain embodiments, the one more oleophobic additives are present in the oil-repellant layer at a concentration of about 3.8%to about 3.9%.

The polysaccharide can be selected from alginate, agarose, hyaluronic acid, carboxymethyl cellulose, hydroxypropyl methylcellulose, carrageenan, collagen, dextran, dextran sulfate, chondroitin sulfate, dermatan sulfate, chitin, chitosan, fully deacetylated chitosan, partially deacetylated chitosan, heparan, heparan sulfate, and conjugate salts thereof and combinations thereof. In certain embodiments the polysaccharide is sodium alginate.

The partially hydrolyzed polyvinyl acetate and partially deacetylated chitosan can comprise up to 10%, up to 20%, up to 30%, up to 40%, up to 50%, up to 60%, up to 70%, up to 80%, up to 90%, up to 95%, or up to 99%of the acetate moieties hydrolyzed.

In certain embodiments, the oil-repellant layer further comprises a binder. Any binder useful as a coating agent for textiles can be used, such as polyacrylate (PA) , polyurethane (PU) , polyvinyl alcohol (PVA) , polyvinyl acetate (PVAc) , polyvinyl butyral (PVB) , polyester (PET) , polylactic acid (PLA) , polyhydroxyalkanoates (PHA) , or polysaccharides. In certain embodiments, the oil-repellant layer comprises a binder selected from the group consisting of polyacrylate, polysaccharides, and a combination thereof. The binder can be present in the oil-repellant layer at a concentration from 10-99%wt/wt, 20-99%wt/wt, 30-99%wt/wt, 40-99%wt/wt, 50-99%wt/wt, 60-99%wt/wt, 70-99%wt/wt, 80-99%wt/wt, 90-99%wt/wt, 91-99%wt/wt, 92-99%wt/wt, 93-99%wt/wt, 94-99%wt/wt, 95-99%wt/wt, 96-99%wt/wt, 90-98%wt/wt, 90-97%wt/wt, 91-97%wt/wt, 92-97%wt/wt, 93-97%wt/wt, 94-97%wt/wt, 95-97%wt/wt, 93-99%wt/wt, 94-98%wt/wt, or 95-97%wt/wt. In certain embodiments, the binder is present in the oil-repellant layer at a concentration about 96%wt/wt. The water-repellant layer primarily acts as a barrier to prevent aqueous liquids, including but not limited to water, alcohol, and mixtures thereof, from wetting the surface of fabric.

The water-repellant layer can comprise 1, 2, 3, 4, 5, or more hydrophobic additives. In certain embodiments, the at least one hydrophobic additive comprises a siloxane, a hydrophobic binder, a silane or a mixture thereof. The hydrophobic additives can be present in the water-repellant layer at a concentration of 80-100%wt/wt, 85-100%wt/wt, 90-100%wt/wt, 91-100%wt/wt, 92-100%wt/wt, 93-100%wt/wt, 94-100%wt/wt, 95-100%wt/wt, 96-100%wt/wt, 97-100%wt/wt, 98-100%wt/wt, or 99-100%wt/wt. In certain embodiments, the water-repellant layer comprises a hydrophobic binder at a concentration of 99-100%wt/wt. In certain embodiments, the water-repellant layer comprises the siloxane and the hydrophobic binder in a mass ratio of 1: 99 to 1: 4, 1: 99 to 3: 17, 5: 95 to 3: 17, 1: 9 to 3: 17, 1: 9 to 7: 43, 1: 9 to 13: 87, 1: 9 to 3: 22, respectively. In certain embodiments, the water-repellant layer comprises the siloxane and the hydrophobic binder at about 1 to about 8 mass ratio, respectively.

In instances in which the surface energy of the siloxanes and silanes used in the preparation of the omniphobic composite coating described herein have a lower surface energy than oils, e.g., less than 50 mJ/m², less than 45 mJ/m², less than 40 mJ/m², less than 35 mJ/m², less than 30 mJ/m², less than 25 mJ/m², less than 20 mJ/m², or less than 19 mJ/m² than they can be used as a hydrophobic additive as well as an oleophobic additive. In certain embodiments, the siloxane and/or silane has a surface energy of between 19-40 mJ/m², 19-35 mJ/m², 19-30 mJ/m², 19-25 mJ/m², 19-24 mJ/m², 19-23 mJ/m², 19-22 mJ/m², 19-21 mJ/m², or 19-20 mJ/m².

The siloxane can be liner, cyclic, branched, unbranched, or mixtures thereof. The siloxane can be terminated by a trialkylsilane group, such as a trimethyl, triethyl, or tripropylsilane) or a vinyl group. In certain embodiments, the siloxane is crosslinked (e.g., such as by hydrosilation of a vinyl terminated siloxane) . Exemplary siloxanes, include but are not limited to polyalkylsiloxanes, In certain embodiments, the siloxane can be a poly [di (C₁-C₆) alkylsiloxane] , a poly [di (C₁-C₅) alkylsiloxane] , a poly [di (C₁-C₄) alkylsiloxane] , a poly [di (C₁-C₃) alkylsiloxane] , a poly [di (C₁-C₂) alkylsiloxane] , a poly [hydrogen (C₁-C₆) alkylsiloxane] , a poly [hydrogen (C₁-C₅) alkylsiloxane] , a poly [hydrogen (C₁-C₄) alkylsiloxane] , a poly [hydrogen (C₁-C₃) alkylsiloxane] , a poly [hydrogen (C₁-C₂) alkylsiloxane] , a poly [di (C₁-C₆) alkylsiloxane-co- (C₁-C₆) alkyllhydrosiloxane] , a poly [di (C₁-C₅) alkylsiloxane-co- (C₁-C₅) alkyllhydrosiloxane] , a poly [di (C₁-C₄) alkylsiloxane-co- (C₁-C₄) alkyllhydrosiloxane] , a poly [di (C₁-C₃) alkylsiloxane-co- (C₁-C₃) alkyllhydrosiloxane] , a poly [di (C₁-C₂) alkylsiloxane-co- (C₁-C₂) alkyllhydrosiloxane] , or a mixture thereof. In certain embodiments, the siloxane is polydimethylsiloxane, poly (dimethylsiloxane-co-methylhydrosiloxane) , or a mixture thereof.

The silane can be a fluorine-free silane with at least one hydrolyzable group and at least one C₁₀-C₂₀alkyl, wherein the hydrolysable group is selected from the group consisting of halide and alkoxide. Exemplary silanes include, but are not limited to, C₁₀-C₂₀alkyltriethoxysilane, C₁₀-C₂₀alkyltrimethoxysilane, C₁₀-C₂₀alkyltrichlorosilane, C₁₀-C₂₀alkyldimethylmethoxysilane, C₁₀-C₂₀alkyldimethylethoxysilane, C₁₀-C₂₀alkyldimethylchlorosilane, C₁₀-C₂₀alkylmethyldimethoxysilane, C₁₀-C₂₀alkylmethyldiethoxysilane, and C₁₀-C₂₀alkylmethyldichlorosilane. In instances in which the water-repellant layer and the oil-repellant layer both comprise a silane, the silane used in the water-repellant layer and the oil-repellant layer can be the same or different.

The hydrophobic binder can comprise an acrylic polymer or copolymer suitable for use as a coating agent for textiles. Acrylic polymers and copolymers useful as hydrophobic additives can comprise C₁-C₆ acrylates, C₁-C₆ methacrylates, C₁-C₆ ethacrylates, acrylic acid, methacrylic acid, and combinations thereof. Acrylic polymers and copolymers can comprise one or more repeating units selected from the group consisting of acrylate, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, methacrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, ethacrylate, methyl ethacrylate, ethyl ethacrylate, propyl ethacrylate, butyl ethacrylate, acrylic acid, and combinations and blends thereof. Acrylic copolymers can further comprise one or more ethylene repeating units. Exemplary binders include, but are not limited to, a fluorine-free waterproofing resin sold under the tradename NOVAGUARD FF Plus by Achitex Minerva S. p. A.

Adhesion promotion layers can increase the adhesion between the water-repellant layer, the oil-repellant layer, and/or the omniphobic coating composite to a textile surface. Crosslinking agents useful for use in the adhesion promotion layers can comprise a polyisocyanate, a polycarbodiimide, a polyaziridine, a silane, a calcium salt, an aluminum salt, or a mixture thereof.

The polyisocyanate is not particularly limited and generally can include any aromatic, alicyclic, and/or aliphatic isocyanates having at least two reactive isocyanate groups (-NCO) . Exemplary polyisocyanates include, but are not limited to 1, 4-diisocyanate, butane 1, 4-diisocyanate, hexane 1, 6-diisocyanate (or hexamethylene diisocyanate; HDI) , HDI dimer (HDID) , HDI trimer (HDIT) , HDI biuret, dicyclohexylmethane diisocyanate, cyclohexane 1, 4-diisocyanate, ethylene diisocyanate, or mixtures thereof.

The silane can be a tetra (C₁-C₃) alkoxysilane, a C₁-C₃alkyltri (C₁-C₃) alkoxysilane, a (3-glycidyloxyalkyl) tri (C₁-₃) alkoxyoxysilane, or a mixture thereof. Exemplary silanes include, but are not limited to tetraethoxysilane (TEOS) , methyltrimethoxysilane (MTMS) , (3-glycidyloxypropyl) trimethoxysilane (GPTMS) , and (3-glycidyloxypropyl) triethoxysilane (GPTES) .

The calcium salt can be any calcium salt that is as at least partially soluble in water. The calcium salt can comprise one or more anions selected from the group consisting of halides (e.g., chloride, bromide, and iodide) , carbonate, nitrate, sulfate, bicarbonate, phosphate, monohydrogen phosphate, dihydrogen phosphate, sulfamate, acetate. In certain embodiments, the calcium salt is calcium chloride.

The aluminum salt can comprise one or more anions selected from the group consisting of (e.g., chloride, bromide, and iodide) , sulfate, and nitrate.

In certain embodiments, each of the one or more adhesion promotion layers independently optionally further comprises a binder. In certain embodiments, the binder comprises polyacrylate (PA) , polyurethane (PU) , polyvinyl alcohol (PVA) , polyvinyl acetate (PVAc) , polyvinyl butyral (PVB) , polyester (PET) , polylactic acid (PLA) , polyhydroxyalkanoates (PHA) , or polysaccharides. The concentration of the binder in the one or more adhesion promotion layers can range from 80-100%wt/wt, 85-100%wt/wt, 90-100%wt/wt, 91-100%wt/wt, 92-100%wt/wt, 93-100%wt/wt, 94-100%wt/wt, 95-100%wt/wt, 96-100%wt/wt, 97-100%wt/wt, 98-100%wt/wt, or 99-100%wt/wt.

In certain embodiments, the omniphobic coating further comprises one or more additives selected from the group consisting of a defoamer, a theological controller, an antimicrobial agent, an antibacterial agent, an antifungal agent, a flame retardant, a UV inhibitor, an antioxidant, a coloring agent, a lubricant, a thickener, an antistatic agent, a fragrance, or mixtures thereof. The one or more additives can be present in the water-repellant layer, the oil-repellant layer, the one or more adhesion promotion layers, or any combination thereof.

The present disclosure also provides a coated textile comprising the omniphobic coating composite described herein disposed on at least one surface of a textile.

The type of textile is not particularly limited and can include individual staple fibers or filaments, yarns, fabrics, and articles (e.g., garments) . Yarns can include, for instance, multiple staple fibers that are twisted together, filaments laid together without twist, filaments laid together with a degree of twist, and a single filament with or without twist. Suitable fabrics can likewise include, for instance, woven fabrics, knit fabrics, and non-woven fabrics. Garments can be apparel and industrial garments. Fabrics and textiles can include home goods, such as linens, drapery, and upholstery.

The omniphobic coating composite of the present disclosure can be applied to all types of textiles, including but not limited to synthetic fibers, such as polyester, a polyamide, a polyolefin, an acrylic, modacrylic, an acetate, a polyurethane, or combinations thereof. Exemplary synthetic fibers include, but are not limited to polyethylene terephthalate (PET) , Kevlar, nomex, spandex, nylon, and the like; organic fibers, such as celluloses, such as one or more of wood, bamboo, cotton, banana, hemp ramie, linen, coconut palm, soya, milk, hoya, bagasse, kanaf, retting, mudrar, silk, wool, cashmere, alpaca, angora wool, mohair, shearling, shahtoosh, and the like; semi-synthetic fibers, such as viscose, cuprammonium, rayon, polynosic, lyocell, cellulose acetate, and the like and combinations thereof. In certain embodiments, the textile comprises cotton or a PET/cotton blend (polycotton) .

Referring to the Figure, the sequence of the water-repellant layer (101) , the oil-repellant layer (102) , and optionally the one or more adhesion promotion layers (103) of the omniphobic coating composite relative to the textile (104) can be varied depending on the desired properties of the coated textile (100) . The Figure illustrates various exemplary embodiments of the omniphobic coating composite including 0, 1, or 2 adhesion promotion layers (103) , between the sequence of the water-repellant layer (101) , the oil-repellant layer (102) , and/or the textile (104) . In certain embodiments, the coated textile comprises the adhesion promotion layer (103) disposed on a surface of the textile (104) , the oil-repellant layer (102) disposed on a surface of the adhesion promotion layer (103) ; and the water-repellant layer (101) disposed on a surface of the oil-repellant layer (102) . It was found that water-repellency and oil-repellency are optimal when the oil-repellant layer (102) is disposed between the textile (104) and the water-repellant layer (101) , wherein the adhesion promotion layer (103) is optionally disposed between one or both of the textile (104) and the oil-repellant layer (102) and the oil-repellant layer and the water-repellant layer (101) .

The one or more adhesion promotion layers can each independently present at 1-5owf%of the blank textile. The oil-repellant layer can be present at 1-20owf%of the blank fabric. The water-repellant layer can be present at 1-20owf%of the blank fabric.

The coated textile can have a water contact angle of up to 140°. In certain embodiments, the coated substrate has a water contact angle of 70-140°, 80-140°, 90-140°, 100-140°, 110-140°, 120-140°, or 130-140°.

The oil-repellent and water-repellent properties of the coated textiles described herein can be preserved even after a number of cycle (s) of washing, drying and re-use. In certain embodiments, the coated textile can have a durability of 1-20, 1-15, 1-10, 1-5, 2-5, 3-5, 4-5, 3-20, 5-20, 10-20, 15-20, 16-20, 17-20, 18-20, or 19-20 washing cycles without significant drop (e.g., less than 1%, less than 2%, less than 3%, less than 4%, less than 5%, less than 10%, less than 15%, or less than 20%drop) in water repellency and oil repellency.

Also provided herein is a method of preparing a coated textile, the method comprising:

The oil-repellant layer precursor solution can comprise any solvent in which the at least one oleophobic additive is at least partially soluble. Exemplary solvents include water, alcohols, and mixtures thereof. In certain embodiments, the solvent is water. The concentration of the at least one oleophobic additive in the oil-repellant layer precursor solution can range from 0.1-10%wt/wt, 1-10%wt/wt, 1-9%wt/wt, 1-8%wt/wt, 1-7%wt/wt, 1-6%wt/wt, 1-5%wt/wt, 1-4%wt/wt, 1-3%wt/wt, or 1-2%wt/wt. In instances in which the oil-repellant layer further comprises a binder, the binder can be present in the oil-repellant layer precursor solution at a concentration of 10-70%wt/wt, 20-70%wt/wt, 30-70%wt/wt, 40-70%wt/wt, 40-60%wt/wt, 45-55%wt/wt, 30-60%wt/wt, 30-50%wt/wt, or 40-50%wt/wt.

The oil-repellant layer precursor solution can be deposited using any number of methods known in the art.

The water-repellant layer precursor solution can comprise any solvent in which the at least one hydrophobic additive is at least partially soluble. Exemplary solvents include water, alcohols, and mixtures thereof. In certain embodiments, the solvent is water. The concentration of the at least one hydrophobic additive in the water-repellant layer precursor solution can range from 0.1-10%wt/wt, 0.1-9%wt/wt, 0.1-8%wt/wt, 0.1-7%wt/wt, 0.1-6%wt/wt, 0.1-5%wt/wt, 0.1-4%wt/wt, 0.1-3%wt/wt, 0.1-2%wt/wt, or 0.1-1%wt/wt. In instances in which the water-repellant layer further comprises a binder, the binder can be present in the water-repellant layer precursor solution at a concentration of 0.1-10%wt/wt, 1-10%wt/wt, 2-10%wt/wt, 3-10%wt/wt, 4-10%wt/wt, 5-10%wt/wt, 6-10%wt/wt, 7-10%wt/wt, 8-10%wt/wt, 9-10%wt/wt, 1-9%wt/wt, 1-8%wt/wt, 1-7%wt/wt, 1-6%wt/wt, 1-5%wt/wt, 2-5%wt/wt, 3-5%wt/wt, or 4-5%wt/wt.

In instances in which the oil-repellant layer comprises sodium alginate, the adhesion of the water-repellant layer with the oil-repellant layer can be advantageously increased by addition of a calcium salt to the water-repellant layer. In certain embodiments, the water-repellant layer precursor solution further comprises a calcium salt comprising one or more anions selected from the group consisting of chloride, bromide, iodide, carbonate, nitrate, sulfate, bicarbonate, phosphate, monohydrogen phosphate, dihydrogen phosphate, sulfamate, acetate. In certain embodiments, the water-repellant layer further comprises calcium chloride. The concentration of the calcium salt in the water-repellant layer precursor solution can range from 0.1-10%wt/wt, 1-10%wt/wt, 1-9%wt/wt, 1-8%wt/wt, 1-7%wt/wt, 1-6%wt/wt, 1-5%wt/wt, 1-4%wt/wt, 1-3%wt/wt, or 1-2%wt/wt. When a water-repellant layer precursor solution comprising a calcium salt is deposited on a surface of an oil-repellant layer comprising sodium alginate an anion exchange reaction results thereby forming calcium alginate.

The adhesion promotion layer precursor solution can comprise any solvent in which the one or more crosslinking agents are at least partially soluble. Exemplary solvents include water, alcohols, alkyl halides, ethers, esters, ketones, formamides, alkylnitriles, alkylsulfoxides, aromatic solvents, and mixtures thereof. In certain embodiments, the solvent is water. The concentration of the one or more crosslinking agents in the adhesion promotion layer precursor solution can range from 0.1-10%wt/wt, 0.1-9%wt/wt, 0.1-8%wt/wt, 0.1-7%wt/wt, 0.1-6%wt/wt, 0.1-5%wt/wt, 0.1-4%wt/wt, 0.1-3%wt/wt, 0.1-2%wt/wt, 0.5-2%wt/wt, or 0.5-1.5%wt/wt.

The order of steps (a) , (b) , optionally (c) , and optionally (d) is determined based on the desired sequence of the water-repellant layer, oil-repellant layer, and optionally the one or more adhesion promotion layers on the textile surface. In certain embodiments, the method comprises:

The precursor solutions described herein can be applied to a surface of a textile using any method known in the art, such as by spin coating, printing, print screening, spraying, electrospinning, painting, brushing, dip coating, dip-padding, knife coating, . The precursor solutions described herein can be applied to a surface of a textile using a brush, blade, roller, sprayer (for example, air-assisted or airless, electrostatic) , vacuum coater, curtain coater, flood coater, or any other means known in the art.

The precursor coatings described herein can be cured at 40-200℃. In certain embodiments, the step of curing can be conducted for 3-30 minutes. Any means for applying heat can be used to cure the precursor coatings described herein. In certain embodiments, an oven and/or hot press machine is used to cure the precursor coatings.

Examples

The present disclosure is further defined in the following Examples. It should be understood that these Examples, while indicating certain preferred embodiments of the disclosure, are given by way of illustration only. The amounts thereof, as well as the conditions elaborated should not be limited in the Examples only.

Example 1

A polyester-cotton fabric was treated by a 3-layer composite surface finish. The composition of fabric includes 65%polyester and 35%cotton and its nominal weight is 180 g/sqm.

The bottom layer of the composite surface finish was directly deposited on the fabric by dipping (1%calcium chloride) , padding (speed=1.0 m/min, pressure=0.98bar) and drying (temperature=60℃, duration=10mins) processes.

The middle layer was applied on top of the bottom layer by knife coating in coating-drying cycles. The process was performed by using knife coating machine at 50mm/sdrawdown speed. The coated fabric was dried in an oven at 60℃ for 10mins. The composition of the coating paste is shown in

Table 5.

Table 5: Composition of knife coating paste of the middle layer.

Finally, the top layer was coated on top of the middle layer by dipping into the paste of

Table 6, padding (speed=1.0 m/min, pressure=0.98bar) and curing (temperature=160℃, duration=5mins) processes.

Table 6: Composition of padding paste of the top layer

The coated fabric was compared with an un-coated fabric in terms of water repellency and oil repellency. The results are shown in

Table 7.

Table 7: Water repellency and oil repellency of coated fabric

The above results show that the 3-layer composite surface finish provides significant water repellency and oil repellency to the fabric.

Example 2

Table 8.

Table 8: Composition of knife coating paste of the middle layer

Table 9, padding (speed=1.0 m/min, pressure=0.98bar) and curing (temperature=160℃, duration=5mins) processes.

Table 9: Composition of padding paste of the top layer

The coated fabric was compared with an un-coated fabric and a C6 fluorochemical comparative example in terms of water repellency and oil repellency. The results are shown in

Table 10.

Table 10: Water repellency and oil repellency of coated fabric

The above results show that the 3-layer composite surface finish provides significant water repellency and oil repellency to the fabric. It also shows comparable performance to a C6 fluorochemical coating system.

Example 3

The middle layer was applied on top of the bottom layer by knife coating in coating-drying cycles. The process was performed by using knife coating machine at 50mm/sdrawdown speed. The coated fabric was dried in an oven at 60℃ for 10mins. The composition of the coating paste is shown in .

Table 11.

Table 11: Composition of knife coating paste of the middle layer

Table 12, padding (speed=1.0 m/min, pressure=0.98bar) and curing (temperature=160℃, duration=5mins) processes.

Table 12: Composition of padding paste of the top layer

Table 13.

Table 13: Water repellency and oil repellency of coated fabric

Example 4

A polyester-cotton fabric was treated by a 3-layer composite surface finish. The composition of fabric includes 65%polyester and 35%cotton and its nominal weight is 225 g/sqm.

Table 14.

Table 14: Composition of knife coating paste of the middle layer

Table 15, padding (speed=1.0 m/min, pressure=0.98bar) and curing (temperature=160℃, duration=5mins) processes.

Table 15: Composition of padding paste of the top layer

Table 16.

Table 16: Water repellency and oil repellency of coated fabric

Example 5

A polyester-cotton fabric was treated by a 2-layer composite surface finish. The composition of fabric includes 65%polyester and 35%cotton and its nominal weight is 180 g/sqm.

The bottom layer of the composite surface finish was directly deposited on the fabric by dipping into the paste of

Table 17, padding (speed=1.0 m/min, pressure=0.98bar) and curing (temperature=60℃, duration=10mins) processes.

Table 17: Composition of knife coating paste of the bottom layer

The top layer was applied on top of the bottom layer by knife coating in coating-drying cycles. The process was performed by using knife coating machine at 50mm/sdrawdown speed. The coated fabric was dried in an oven at 160℃ for 5mins. The composition of the coating paste is shown in Table 18.

Table 18: Composition of padding paste of the top layer

The coated fabric was compared with an un-coated fabric and a C6 fluorochemical comparative example in terms of water repellency and oil repellency. The results are shown in Table 19.

Table 19: Water repellency and oil repellency of coated fabric

Claims

An omniphobic coating composite comprising a water-repellant layer, an oil-repellant layer, and optionally one or more adhesion promotion layers, wherein the water-repellant layer comprises at least one hydrophobic additive, the oil-repellant layer comprises at least one oleophobic additive, and the one or more adhesion promotion layers comprise one or more crosslinking agents, wherein the omniphobic coating composite is fluorine-free.
The omniphobic coating composite of claim 1, wherein the at least one oleophobic additive is selected from the group consisting of a polysaccharide, a polyvinyl alcohol, a siloxane, a silane, and a polyacrylic acid.
The omniphobic coating composite of claim 2, wherein the polysaccharide comprises chitosan, fully deacetylated chitosan, partially deacetylated chitosan, a metal alginate, a starch, or a mixture thereof.
The omniphobic coating composite of claim 1, wherein the at least one hydrophobic additive comprises a siloxane, a silane, a hydrophobic binder, or a mixture thereof.
The omniphobic coating composite of claim 4, wherein the siloxane comprises a poly (dialkylsiloxane) , a poly (alkylhydrogensiloxane) , a poly (dialkylsiloxane-co-alkyllhydrosiloxane) , or a mixture thereof; the silane comprises at least one hydrolyzable group and at least one C₁₀-C₂₀ alkyl, wherein the hydrolysable group is selected from the group consisting of halide and alkoxide; and the hydrophobic binder comprises an acrylic copolymer.
The omniphobic coating composite of claim 1, wherein the oil-repellant layer further comprises a binder.
The omniphobic coating composite of claim 1, wherein the water-repellant layer further comprises a crosslinking agent.
The omniphobic coating composite of claim 7, wherein the crosslinking agent is a polyisocyanate, a polycarbodiimide, a polyaziridine, a silane, a calcium salt, an aluminum salt, or a mixture thereof.
The omniphobic coating composite of claim 1, wherein the one or more crosslinking agent comprises a polyisocyanate, a polycarbodiimide, a polyaziridine, a silane, a calcium salt, an aluminum salt, or a mixture thereof.
The omniphobic coating composite of claim 1, wherein the one or more crosslinking agent is calcium chloride.
The omniphobic coating composite of claim 1, wherein the at least one oleophobic additive comprises a polysaccharide, a polyvinyl alcohol, a partially hydrolyzed polyvinyl acetate, a poly (dialkylsiloxane) , a poly (alkylhydrogensiloxane) , a poly (dialkylsiloxane-co-alkyllhydrosiloxane) , or a polyacrylic acid; the at least one hydrophobic additive comprises a poly (dialkylsiloxane) , a poly (alkylhydrogensiloxane) , a poly (dialkylsiloxane-co-alkyllhydrosiloxane) , a silane, a hydrophobic binder, or a mixture thereof; and the one or more crosslinking agents comprise a polyisocyanate, a polycarbodiimide, a polyaziridine, a silane, a calcium salt, an aluminum salt, or a mixture thereof.
The omniphobic coating composite of claim 1, wherein the at least one oleophobic additive comprises a poly (dialkylsiloxane) , a poly (alkylhydrogensiloxane) , a poly (dialkylsiloxane-co-alkyllhydrosiloxane) , sodium alginate, or a mixture thereof; the at least one hydrophobic additive comprises a poly (dialkylsiloxane) , a poly (alkylhydrogensiloxane) , a poly (dialkylsiloxane-co-alkyllhydrosiloxane) , an acrylic copolymer, wherein the acrylic copolymer comprises one or more repeating units selected from the group consisting of acrylate, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, methacrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, ethacrylate, methyl ethacrylate, ethyl ethacrylate, propyl ethacrylate, butyl ethacrylate, acrylic acid, ethylene monomers, or combinations or blends thereof; and the one or more crosslinking agents comprise calcium chloride.
The omniphobic coating composite of claim 12, wherein the water-repellant layer further comprises calcium chloride.
A coated textile comprising the omniphobic coating composite of claim 1 disposed on at least one surface of a textile.
The coated textile of claim 14, wherein the oil-repellant layer is disposed between the textile and the water-repellant layer.
A method of preparing the coated textile of claim 14, the method comprising:

(a) depositing a water-repellant layer precursor solution comprising the at least one hydrophobic additive thereby forming a water-repellant layer precursor coating and curing the water-repellant layer precursor thereby forming the water-repellant layer;

(b) depositing an oil-repellant layer precursor solution comprising the at least one oleophobic additive thereby forming an oil-repellant layer precursor coating and curing the oil-repellant layer precursor thereby forming the oil-repellant layer;

(c) optionally depositing an adhesion promotion layer precursor solution comprising one or more crosslinking agents thereby forming an adhesion promotion layer precursor coating; and curing the adhesion promotion layer precursor coating thereby forming an adhesion promotion layer; and

(d) optionally repeating step (c) thereby forming the one or more adhesion promotion layers,

wherein (a) , (b) , optionally (c) , and optionally (d) are conducted on or more surfaces of the textile in any order thereby forming the preparing the coated textile.
The method of claim 16, wherein the method comprises:

(a) depositing the adhesion promotion layer precursor solution on a surface of the textile thereby forming the adhesion promotion layer precursor coating the surface of the textile;

(b) curing the adhesion promotion layer precursor coating thereby forming the adhesion promotion layer;

(c) depositing the oil-repellant layer precursor solution on a surface of the adhesion promotion layer thereby forming the oil-repellant layer precursor coating;

(d) curing the oil-repellant layer precursor coating thereby forming the oil-repellant layer;

(e) depositing the water-repellant layer precursor solution on a surface of the oil-repellant layer thereby forming the water-repellant layer precursor coating; and

(f) curing the water-repellant layer precursor coating thereby forming the coated textile.
The method of claim 17, wherein the water-repellant layer precursor solution further comprises a crosslinking agent.
The method of claim 17, wherein each curing step independently comprises heating at 40℃ –200℃.
The method of claim 17, wherein each of the water-repellant layer precursor solution, the oil-repellant layer precursor solution, and optionally the adhesion promotion layer precursor solution comprise water.