MANUFACTURE OF GARMENT MATERIALS FIELD OF THE INVENTION

[0001] The present invention relates to functionalized, water vapor permeable composites, a process for their manufacture, and use thereof.

BACKGROUND OF THE INVENTION

[0002] Description of the Related Art

[0003] The term "functionalization" and related terminology are used in the art and herein to refer to the process of treating a material to alter its surface properties to meet specific requirements for a particular application. For example, the surface energy of a material may be treated to render it particularly hydrophobic or hydrophilic as may be desirable for a given use. Thus, surface functionalization has become common practice in the manufacture of many materials because it adds value to the end product. In order to achieve such different ultimate results, functionalization may be carried out in a variety of ways ranging from wet chemistry to various forms of vapor deposition, vacuum metallization and sputtering.

[0004] Some examples of functional materials include hydrophilic materials, including monomers containing one or more of hydroxyl, carboxyl, sulphonic, amino, or amido functional groups; hydrophobic materials, including monomers or sol-gels containing a fluorinated functional group, or monomers or sol-gels comprising a hydrophobic nanostructure; antimicrobial materials, including monomers or sol-gels comprising an antimicrobial functional group, an encapsulated antimicrobial agent, a chlorinated aromatic compound, or a naturally occurring antimicrobial agent; fire-retardant materials, including monomers or sol-gels comprising a brominated functional group; self-cleaning materials, including photo-catalytically active chemicals, a metal oxide; zinc oxide, titanium dioxide, or tungsten dioxide; ultraviolet protective materials, including titanium dioxide; highly conjugated organic compounds or metal oxide compounds, acrylic polymers; and, infrared- reflective materials, including materials comprising aluminum, gold, silver, zinc, tin, lead, copper, AgGe, CuZn, CuSn, CuAg, CuAgSn, or any alloy, oxide, or combination of these materials having a desired emissivity.

[0005] The term "superhydrophobic" is known in the art, and includes a material property whereby the contact angle of a water droplet is extremely high, for example, exceeding 150°.

[0006] The term "superhydrophilic" is known in the art, and includes a material property whereby the contact angle of a water droplet is extremely low, for example, approximately 0°.

[0007] The term "wicking" is known in the art, and includes a material property whereby moisture is transported into a fabric or other material by capillary or other action.

[0008] Various types of composite materials manufacturing are known in the prior art.

[0009] Unfortunately, these manufacturing methods and devices have a number of deficiencies making them less suitable for creating composites for incorporation into apparel, particularly in the resulting composites' thermal properties, moisture management, water repellency, and durability. [0010] For example, US Patent Application Publication US

2004/0213918 A1 (Mikhael et al.) discloses a process for functionalizing a porous substrate, such as a nonwoven fabric or paper, with a layer of polymer, and optionally a layer of metal or ceramic. According to one embodiment, the process includes the steps of flash evaporating a monomer having a desired functionality in a vacuum chamber to produce a vapor, condensing the vapor on the porous substrate to produce a film of the monomer on the porous substrate, curing the film to produce a functionalized polymeric layer on the porous substrate, vacuum depositing an inorganic layer over the polymer layer, flash evaporating and condensing a second film of monomer on the inorganic layer and curing the second film to produce a second polymeric layer on the inorganic layer. Mikhael et al. also discloses another embodiment including the steps of flash evaporating and condensing a first film of monomer on the porous substrate to produce a first film of the monomer on the porous substrate, curing the film to produce a functionalized polymeric layer on the porous substrate, vacuum depositing a metal layer over the polymer layer, and flash evaporating and condensing a second film of monomer on the metal layer and curing the second film to produce a second polymeric layer on the metal layer.

[0011] US Patent Applications US 2007/0166528 A1 (Barnes et al.) discloses a process for oxidising the surface of a metal coating with an oxygen-containing plasma to form a synthetic metal oxide coating, making a superior resistance to corrosion of the metallized porous sheet. For applications whereby it is desirable to have some amount of stretch of the functionalised composite, current coating processes have produced unsatisfactory results with reduced benefit of the functionalization of the outer exposed surface(s). [0012] However, in these cases, the coating layers do not cover the underlying sub-surfaces of the substrate that are exposed only after stretching the material.

[0013] It is therefore desirable to provide methods and devices for the manufacture of composite garment materials which address these

deficiencies.

SUMMARY OF THE INVENTION

[0014] Accordingly, it is an object of the present invention to provide a method and apparatus for the manufacture of composite garment materials.

[0015] These and other objectives are achieved by providing a method of manufacturing a heat reflective composite comprising the steps of providing a stretchable porous substrate; stretching the stretchable porous substrate; and depositing at least one coating onto one or more surfaces of the stretchable porous substrate while it is stretched. At least one coating comprises an infrared-reflective material; and, at least one coating is deposited such that when the stretchable porous substrate is unstretched, the coating or coatings do not extend completely across pores of the stretchable porous substrate.

[0016] Other objects of the present invention are achieved by providing an apparatus for manufacturing a heat reflective composite comprising a vacuum chamber; a vacuum pump evacuating the vacuum chamber; an unwind roll within the vacuum chamber; substrate material wound onto the unwind roll; a cooled rotating drum rotating within the vacuum chamber, unwinding the substrate material from the unwind roll onto the surface of the cooled rotating drum such that a first surface of the substrate faces outward from the cooled rotating drum and a second surface of the substrate faces the cooled rotating drum; one or more deposition stations within the vacuum chamber depositing materials onto the substrate material while the substrate material is disposed on the surface of the cooled rotating drum, creating a coated substrate material; and, a wind-up roll within the vacuum chamber, winding the coated substrate material up off of the cooled rotating drum.

[0017] Other objects of the invention and its particular features and advantages will become more apparent from consideration of the following drawings and accompanying detailed description.

[0018] In view of the foregoing, this invention is directed at a process that is suitable for functionalizing a broad range of stretchable substrates, including synthetic and natural fabrics, fibres and non-woven materials.

Because of the fibrous nature of these substrates and their general commercial uses, the invention is directed particularly at maintaining the breathability of the materials, providing durability in the coatings and prolonged resistance to washing and cleaning, and selectively treating one or both sides of the fabric material. The invention also aims at a process that is compatible with the use of existing equipment and with the application of other coating layers, including various additives and catalysts currently utilized in the art.

[0019] According to a first embodiment, the present invention is directed to a functionalised composite comprising a stretchable porous substrate having first and second outer surfaces and at least one coating on said first or second outer surface of the substrate, said coating comprising an organic or inorganic coating layer of a composition containing a material selected from the group consisting of organic polymers, organic oligomers, sol-gels and combinations thereof, having a thickness between about 0.2 micrometer and 2.5 micrometers deposited on the substrate, wherein the total combined thickness of all coating layers is no greater than about 2.5 micrometers.

[0020] Another embodiment of the present invention relates to an infrared reflective functionalised composite comprising a stretchable porous substrate having first and second outer surfaces whereby the composite is formed by coating at least one side of the substrate with at least one metal layer and at least one thin organic or in-organic coating layer deposited on the surface of the substrate between the substrate layer and the metal coating layer. A further organic or in-organic layer is optionally applied on the outside of the metal layer. Said organic or in-organic coatings are comprised of a material selected from the group consisting of organic polymers, organic oligomers, sol-gels and combinations thereof and have a thickness between about 0.2 micrometer and 2.5 micrometers, wherein the total combined thickness of the intermediate and outer organic or in-organic coating layers is no greater than about 2.5 micrometers.

[0021] In one aspect of the present invention, the said substrate is stretched before the application of the said coating layers as to allow the underlying sub-surfaces of the substrate that are only exposed in the materials extended state to also be coated. The coatings are preferably formed under vacuum using vapor deposition techniques under conditions that substantially coat the substrate without significantly reducing its moisture vapor permeability.

[0022] In another embodiment of the present invention, the metal layer can additionally have increased corrosion resistance by oxidizing the surface of a metal coating with an oxygen-containing plasma to form a self protecting metal oxide coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG. 1 is a schematic diagram of an example apparatus suitable for forming the composites according to aspects of the invention with the stretching feature omitted for clarity.

[0024] FIGS. 2a and 2b are flow charts illustrating example methods according to aspects of the invention.

[0025] FIG. 3 is a flow chart illustrating an example method according to aspects of the invention.

[0026] FIG. 4 is a cross-sectional view of an example coated material according to aspects of the invention.

[0027] FIG. 5a and 5b are illustrations of example composite materials according to aspects of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0028] As used herein, the term "metal" includes metal alloys as well as metals.

[0029] In one embodiment, the present invention is directed to a functionalised composite comprising a stretchable porous substrate having first and second outer surfaces and at least one coating on at least one surface of the substrate, said coating comprising an organic or inorganic coating layer of a composition containing a material selected from the group consisting of organic polymers, organic oligomers, sol-gels and combinations thereof, having a thickness between about 0.2 micrometer and 2.5

micrometers deposited on the substrate, wherein the total combined thickness of all coating layers is no greater than about 2.5 micrometers. [0030] Another embodiment of the present invention relates to an infrared reflective functionalised composite comprising a stretchable porous substrate having first and second outer surfaces whereby the composite is formed by coating at least one side of the substrate with at least one metal layer and at least one thin organic or in-organic coating layer deposited on the surface of the substrate between the substrate layer and the metal coating layer. The coatings are preferably formed under vacuum using vapor deposition techniques under conditions that substantially coat the substrate without significantly reducing its moisture vapor permeability.

[0031] Another embodiment of the present invention relates to an infrared reflective functionalised composite comprising a stretchable porous substrate having first and second outer surfaces whereby the composite is formed by coating at least one side of the substrate with at least one metal layer and at least one thin organic or in-organic coating layer deposited on the surface of the substrate between the substrate layer and the metal coating layer and at least one thin organic or in-organic coating layer on the surface of the metal layer opposite the substrate layer. The coatings are preferably formed under vacuum using vapor deposition techniques under conditions that substantially coat the substrate without significantly reducing its moisture vapor permeability.

[0032] The composite of the present invention can include the following layers: Substrate/L2, Substrate/L1/M, Substrate/L1/M/L2, and

Substrate/L1/M/L2/M/L3, Substrate/IL2 Substrate/L1/M/IL2,

Substrate/IL1/M/IL2 etc. where Substrate is a stretchable porous substrate layer, L1 , L2, and L3 are organic coating layers comprising an organic polymer or organic oligomer, or blends thereof and IL1 and IL2 are inorganic coating layers comprising a sol-gel and M is a low emissivity metal layer. For composites with one or more metal layers, the abbreviations "L1" and "IL1" are used herein to refer to an intermediate organic coating layer that is deposited on a surface of the substrate layer prior to depositing a metal layer thereon. In composite substrate structures having more than one metal layer, individual metal layers can be formed from the same or different metal and can have the same or different thickness. Similarly, in structures having more than one organic or in-organic coating layer, the individual organic or inorganic coating layers can have the same or different composition and/or thickness. Each metal layer can comprise more than one adjacent metal layers wherein the adjacent metal layers can be the same or different.

Similarly, each organic or in-organic layer can comprise more than one adjacent organic or inorganic layer, wherein the adjacent organic or in-organic layers can be the same or different. The substrate layer can be coated on one side, as in the structures described above, or on both sides such as in the following structures: L1/Substrate/L1 , L1/Substrate/L1/M/L2,

L2/M/L1/Substrate/L1/M/L2, IL1/Substrate/L1 , I L1 /Substrate/I L1 , IL1

/Substrate/L1/M/IL2, IL2/M/IL1/Substrate/IL1/M/IL2 etc.

[0033] In a preferred embodiment of the present invention, the said organic or in-organic coatings comprise one or more functional components. Functionalities include hydrophilic coatings from monomers functionalized with groups including hydroxyl, carboxyl, sulphonic, amino, amido and others. Hydrophobic coatings from monomers and/or sol-gels with fluorinated functional groups and/or monomers and/or sol-gels that create nanostructure on the textile surface. Antimicrobial coatings from a monomer and/or sol-gels with antimicrobial functional groups and/or encapsulated antimicrobial agents (including chlorinated aromatic compounds and naturally occurring

antimicrobials). Fire retardant coatings from monomers and/or sol-gels with a brominated functional group. Self cleaning coatings from monomers and/or sol gels that have photo-catalytically active chemicals present (including zinc oxide, titanium dioxide, tungsten dioxide and other metal oxides). Ultraviolet protective coating from monomers and/or sol-gels that contain UV absorbing agents (including highly conjugated organic compounds and metal oxide compounds).

[0034] In a preferred embodiment of the present invention, the porous substrate is a stretchable, woven non-woven or knitted textile. Textiles are fiber-based porous materials with inherent properties derived from the nature of the fibers. Synthetic and natural fibers (for example, polypropylene, nylon, polyethylene, polyester, spandex, cellulosic fibers, wool, silk, and other polymers and blends) can be shaped into different products with a great range of mechanical and physical properties. In addition, the porosity of these materials usually serves a necessary function, such as gas and/or liquid permeation, particulate filtration, liquid absorption, etc. Therefore, any subsequent treatment designed to further modify the chemical properties of the fibers by appropriately functionalizing them must be carried out, to the extent possible, without affecting the porosity of the material. This has heretofore been virtually impossible when such functionalization results from the deposition of polymers.

[0035] In another embodiment of the invention, the porous substrate features a stretchable micro-porous, moisture vapour permeable and substantially liquid impermeable film. Microporous films are well known in the art, such as those formed from a mixture of a polyolefin (e.g. polyethylene) and fine particulate fillers, which is melt-extruded, cast or blown into a thin film and stretched, either mono- or bi-axially to form irregularly shaped micropores which extend continuously from the top to the bottom surface of the film. U.S. Pat. No. 5,955,175 discloses microporous films, which have nominal pore sizes of about 0.2 micrometer. Microporous films can be laminated between nonwoven or woven layers using methods known in the art such as thermal or adhesive lamination. [0036] In another embodiment of the present invention, the said porous substrate is combined with non-porous substrate prior to the application of said functional metal or organic or in-organic coating layers. The said coating layers can be applied the surface of the substrate facing away from the said non-porous substrate and also to the surface of the non-porous substrate facing away from the porous substrate. In one embodiment said non-porous substrate is a neoprene or neoprene foam cut into thin sheets about 0.5mm- 5mm in thickness. In another embodiment said non-porous substrate is water vapour permeable, substantially liquid impermeable non-porous monolithic film or membrane. Moisture vapor permeable monolithic (non-porous) films are formed from a polymeric material that can be extruded as a thin, continuous, moisture vapor permeable, and substantially liquid impermeable film. The film layer can be extruded directly onto a first nonwoven, woven or knitted layer using conventional extrusion coating methods. Preferably, the monolithic film is no greater than about 3 mil (76 micrometers) thick, even no greater than about 1 mil (25 micrometers) thick, even no greater than about 0.75 mil (19 micrometers) thick, and even no greater than about 0.60 mil (15.2 micrometers) thick. In an extrusion coating process, the extruded layer and substrate layer are generally passed through a nip formed between two rolls (heated or unheated), generally before complete solidification of the film layer, in order to improve the bonding between the layers. A second nonwoven, woven or knitted layer can be introduced into the nip on the side of the film opposite the first substrate to form a moisture vapor permeable, substantially air impermeable laminate wherein the monolithic film is sandwiched between the two textile layers. Polymeric materials suitable for forming moisture vapor permeable monolithic films include block polyether copolymers such as a block polyether ester copolymers, polyetheramide copolymers, polyurethane copolymers, poly(etherimide) ester copolymers, polyvinyl alcohols, or a combination thereof. Preferred copolyether ester block copolymers are segmented elastomers having soft polyether segments and hard polyester segments, as disclosed in Hagman, U.S. Pat. No. 4,739,012 that is hereby incorporated by reference. Suitable copolyether ester block copolymers include Hytrel® copolyether ester block copolymers sold by E. I. du Pont de Nemours and Company (Wilmington, Del.), and Arnitel® polyether-ester copolymers manufactured by DSM Engineering Plastics, (Heerlen,

Netherlands). Suitable copolyether amide polymers are copolyamides available under the name Pebax® from Atochem Inc. of Glen Rock, N.J . , USA. Pebax® is a registered trademark of Elf Atochem, S.A. of Paris, France. Suitable polyurethanes are thermoplastic urethanes available under the name Estane® from The B. F. Goodrich Company of Cleveland, Ohio, USA.

Suitable copoly(etherimide) esters are described in Hoeschele et al., U.S. Pat. No. 4,868,062. The monolithic film layer can be comprised of multiple layers moisture vapor permeable film layers. Such a film may be co-extruded with layers comprised of one or more of the above described breathable

thermoplastic film materials. According to the present invention, the metal or organic or in-organic coating layers are deposited on a stretchable porous, substrate using methods that do not substantially reduce the moisture vapor permeability of the substrate. The metal and organic or in-organic coating layers are deposited via a vacuum vapour deposition on the surface such that the coating layers are applied only to the exposed "outer" surfaces of the fibres or film without covering the pores of the substrate.

[0037] In a further aspect of the present invention, the metal or organic or in-organic coating layers are deposited on a stretchable porous substrate via a vacuum vapour deposition method wherein the substrate is pre- stretched so that the said coating layers are deposited onto the substrate while it in a stretched state. This method has been shown to improve the coverage of the coating layers by coating underlying sub-surfaces of the substrate that are only exposed when the material is stretched to an extended state. The substrate is preferably stretched in either or both length and width prior to the application of the said coating layers, the amount in which the substrate is stretched should be the same or more than the substrate would typically be stretched during normal use. For example, the substrate may be stretched to any desired additional fraction of its unstretched length, of which it is capable without damage.

[0038] In a further aspect of the present invention, the said metal, or organic, or in-organic coatings are deposited on the stretchable porous substrate so that said coatings do not extend across the pores of the said substrate so thatonly the coated surface is funtionalized thereby allowing both surfaces of the said substrate to have different functional properties.

[0039] Vacuum vapor deposition methods known in the art are preferred for depositing the metal and organic or inorganic coatings. The thickness of the metal and organic or in-organic coatings are preferably controlled within ranges that provide a composite substrate having an emissivity no greater about 0.35.

[0040] For embodiments with that feature a infra-red reflective metal layer, the thickness and the composition of the organic or in-organic coating layer(s) are selected such that, in addition to not substantially changing the moisture vapor permeability of the substrate layer, it does not significantly increase the emissivity of the metalized substrate. The outer organic or inorganic coating layer preferably has a thickness between about 0.2 pm and 2.5 μιτι, which corresponds to between about 0.15 g/m 2 to 1.9 g/m 2 of the coating material. In one embodiment, the outer coating layer has a thickness between about 0.2 pm and 1.0 pm (about 0.15 g/m 2to 0.76 g/m 2 ). The combined thickness of the intermediate and outer organic or in-organic layers is preferably no greater than about 2.5 pm, even no greater than about 2.0 pm, even no greater than about 1.5 pm. In one embodiment, the combined thickness of the intermediate and outer organic or in-organic coating layers is no greater than about 1.0 pm. For the structure Substrate/L1/M/L2, the intermediate coating layer preferably has a thickness between about 0.02 pm and 2 μηη, corresponding to between about 0.015 g/m 2 and 1.5 g/m 2 . In one embodiment, the intermediate coating layer has a thickness between about 0.02 μιτι and 1 pm (0.015 g/m 2 and 0.76 g/m 2 ).

[0041] When additional metal and organic or in-organic layers are deposited, the thickness of each organic or in-organic coating layer is adjusted such that the total combined thickness of all the organic or in-organic coating layers is no greater than about 2.5 μηη. If the outer organic or inorganic coating layer is too thin, it may not protect the metal layer from oxidation, resulting in an increase in emissivity of the composite substrate. If the outer organic or in-organic coating layer is too thick, the emissivity of the composite substrate can increase, resulting in lower thermal barrier properties.

[0042] Suitable compositions for the organic coating layer(s) include polyacrylate polymers and oligomers. The coating material can be a cross- linked compound or composition. Precursor compounds suitable for preparing the organic coating layers include vacuum compatible monomers, oligomers or low MW polymers and combinations thereof. Vacuum compatible monomers, oligomers or low MW polymers should have high enough vapor pressure to evaporate rapidly in the evaporator without undergoing thermal degradation or polymerization, and at the same time should not have a vapor pressure so high as to overwhelm the vacuum system. The ease of evaporation depends on the molecular weight and the intermolecular forces between the monomers, oligomers or polymers. Typically, vacuum compatible monomers, oligomers and low MW polymers useful in this invention can have weight average molecular weights up to approximately 1200. Vacuum compatible monomers used in this invention are preferably radiation polymerizable, either alone or with the aid of a photoinitiator, and include acrylate monomers functionalized with hydroxyl, ether, carboxylic acid, sulfonic acid, ester, amine and other functionalities. The coating material may be a hydrophobic compound or composition. The coating material may be a crosslinkable, hydrophobic and oleophobic fluorinated acrylate polymer or oligomer, according to one preferred embodiment of the invention. Vacuum compatible oligomers or low molecular weight polymers include diacrylates, triacrylates and higher molecular weight acrylates functionalized as described above, aliphatic, alicyclic or aromatic oligomers or polymers and fluorinated acrylate oligomers or polymers. Fluorinated acrylates, which exhibit very low intermolecular interactions, useful in this invention can have weight average molecular weights up to approximately 6000. Preferred acrylates have at least one double bond, and preferably at least two double bonds within the molecule, to provide high-speed polymerization. Examples of acrylates that are useful in the coating of the present invention and average molecular weights of the acrylates are described in U.S. Pat. No. 6,083,628 and WO 98/18852. Suitable compositions for the in-organic coating layers include metal oxide components including but not limited to Silicone dioxide, titanium dioxide, tungsten dioxide, zinc oxide. Inorganic coating layer(s) can be made by the sol-gel process of depositing a partially reacted metal alkoxide onto the substrate in the presence of water and an alcohol. The layer can also be produced from the deposition of a metal chloride solution. After application layers may be reduced in thickness by dry or moist heat treatment. The most effective method for deposition of metal alkoxide or metal chloride solutions onto the substrate is by flash evaporation and deposition in a vacuum environment.

[0043] Metals suitable for forming the metal layer(s) of the composites of the present invention include aluminum, gold, silver, zinc, tin, lead, copper, and their alloys. The metal alloys can include other metals, so long as the alloy composition provides a low emissivity composite substrate. Each metal layer has a thickness between about 10 nm and 200 nm. In one embodiment, the metal layer comprises aluminum having a thickness between about 10 and 150 nm. Methods for forming the metal layer are known in the art and include resistive evaporation, electron beam metal vapor deposition, or sputtering. If the metal layer is too thin, the desired thermal barrier properties will not be achieved. If the metal layer is too thick, it can crack and flake off and also reduce the moisture vapour permeability of the composite. Generally it is preferred to use the lowest metal thickness that will provide the desired thermal barrier properties. When the composite of the present invention is used in a garment the metal layer reflects infrared radiation providing a radiant thermal barrier that reduces energy loss and keeps the person wearing the garment warmer.

[0044] The thermal barrier properties of a material can be characterized by its emissivity. Emissivity is the ratio of the power per unit area radiated by a surface to that radiated by a black body at the same temperature. A black body therefore has an emissivity of one and a perfect reflector has an emissivity of zero. The lower the emissivity, the higher the thermal barrier properties. Each metal layer, intermediate organic or in-organic coating and adjacent outer organic in-organic coating layer is preferably deposited sequentially under vacuum without exposure to air or oxygen so that there is no substantial oxidation of the metal layer. Polished aluminum has an emissivity between 0.039-0.057, silver between 0.020 and 0.032, and gold between 0.018 and 0.035. A layer of uncoated aluminum generally forms a thin aluminum oxide layer on its surface upon exposure to air and moisture. The thickness of the oxide film increases for a period of several hours with continued exposure to air, after which the oxide layer reaches a thickness that prevents or significantly hinders contact of oxygen with the metal layer, reducing further oxidation. Oxidized aluminum has an emissivity between about 0.20-0.31. By minimizing the degree of oxidation of the aluminum by depositing the outer organic or in-organic coating layer prior to exposing the aluminum layer to the atmosphere, the emissivity of the composite substrate is significantly improved compared to an unprotected layer of aluminum. The outer organic coating layer also protects the metal from mechanical abrasion during roll handling, garment production and end-use.

[0045] In its preferred embodiment, the invention is practiced by first pretreating the porous substrate in a plasma field and then immediately subjecting it to the deposition of a thin layer of vaporized monomer or sol-gel in a vacuum deposition process under conditions that prevent the formation of condensate blocking the pores of the substrate. The monomer or sol-gel film is subsequently cured by exposing it to an electron-beam field or other radiation curing process. The monomer or sol-gel is flash-evaporated and condensed on the porous substrate in conventional manner but, in order to retain the structural porosity and the related functional properties of the substrate, the residence time of the substrate within the deposition zone of the vacuum chamber is controlled to ensure that a very thin film is deposited relative to the size of the pores in the substrate. Thus, monomer or sol-gel penetration within the porous structure of the substrate produces a coating of individual fibers (or pore walls) without sealing the openings between fibers. This is achieved by controlling the vapor density and the speed of the moving substrate to limit the thickness of the coating to about 0.02 to 3 μιτι.

[0046] Vacuum plasma has been used for some time to pretreat as well as to finish treating products of vapor deposition processes. Pretreatment is used to clean and activate the substrate. These functions are attributed to the plasma ablation of contaminants and the generation of free radical and ionic species, respectively. Plasma finishing treatment has been shown to have chemical and physical effects that are useful in improving the outcome of vapor-deposition processes. For example, plasma for hydrocarbon gases and other functional monomer vapors that polymerize on the vapor-deposited surface may be added (plasma grafting and polymerization) to produce specific results, such as hydrophilic and hydrophobic surfaces. [0047] We found that, when coupled with the vacuum deposition of monomers or sol-gels over fibrous substrates, plasma pretreatment produces the additional unexpected effect of preventing the formation of monomer or sol-gel droplets (an effect referred to as "beading" in the art) over the substrate. This discovery is particularly advantageous to prevent the plugging of pores in fabrics, paper and other porous materials being coated with functionalizing monomers. Therefore, the combination of plasma pretreatment with vapor deposition is much preferred in carrying out the invention.

[0048] FIG. 1 is a schematic diagram of an apparatus 10 suitable for vapor-deposition coating of a substrate layer with organic, in-organic and metal layers under vacuum. In the description that follows, the term monomer is used to refer to vaporizable monomers, oligomers, and low molecular weight polymers. In the description that follows, the term sol-gel is used to refer to a solution of partially reacted metal alkoxide in the presence of water and an alcohol. The term inorganic layer includes layers of sol-gel

composition.

[0049] A vacuum chamber 12 is connected to a vacuum pump 14 , which evacuates the chamber to the desired pressure. Suitable pressures are between 2x10 -4 to 2^10 -5 Torr (2.66x 10 -5 to 2.66x10 -6 kPa). Moisture vapor permeable substrate 20 is fed from unwind roll 18onto a cooled rotating drum 16 , which rotates in the direction shown by arrow "A", via guide roll 24 . The surface speed of drum 16 is generally in the range of 1 to 1000 cm/second. The substrate passes through several deposition stations after which it is picked off of the surface of the rotating drum by guide roller 26 and taken up by wind-up roll 22 as a coated composite substrate. Drum 16 is cooled to a temperature specific to the particular monomer or sol-gel being used to form the organic or in-organic coating, and can be cooled down to -20° C. to facilitate condensation of the monomer or sol-gel. After unwinding from roll 18 , the substrate layer passes through optional plasma treatment unit 36 , where the surface of the substrate is exposed to a plasma to remove adsorbed oxygen, moisture, and any low molecular weight species on the surface of the substrate prior to forming the metal or monomer coating thereon. The surface energy of the substrate is generally modified to improve wetting of the surface by the coating layers. The plasma source may be low frequency RF, high frequency RF, DC, or AC. Suitable plasma treatment methods are described in U.S. Pat. No. 6,066,826, WO 99/58757 and WO 99/59185.

[0050] An intermediate organic or in-organic layer is formed on the substrate layer prior to depositing the metal layer. In one embodiment, organic monomer or sol-gel is deposited on the moisture vapor permeable substrate layer by monomer evaporator 28 , which is supplied with liquid monomer or sol-gel solution from a reservoir 40 through an ultrasonic atomizer 42 , where, with the aid of heaters (not shown), the monomer or sol-gel liquid is instantly vaporized, i.e., flash vaporized, so as to minimize the opportunity for polymerization or thermal degradation prior to being deposited on the substrate layer. The monomer, oligomer, sol-gel solution or low molecular weight polymer liquid or slurry is preferably degassed prior to injecting it as a vapor into the vacuum chamber, as described in U.S. Pat. No. 5,547,508, which is hereby incorporated by reference. The specific aspects of the flash evaporation and monomer deposition process are described in detail in U.S. Pat. Nos. 4,842,893; 4,954,371 ; and 5,032,461 , all of which are incorporated herein by reference.

[0051] The flash-vaporized monomer or sol-gel solution condenses on the surface of the substrate and forms a liquid monomer or sol-gel film layer. The monomer or sol-gel coating layer so that the composite substrate has a moisture vapor permeability of at least about 80% of the starting substrate layer. The condensed liquid monomer or sol-gel is solidified within a matter of milliseconds after condensation onto the substrate using a radiation curing means 30 . Suitable radiation curing means include electron beam and ultraviolet radiation sources which cure the monomer or sol-gel film layer by causing polymerization or cross-linking of the condensed layer. If an electron beam gun is used, the energy of the electrons should be sufficient to polymerize the coating in its entire thickness as described in U.S. Pat. No. 6,083,628, which is incorporated herein by reference. The polymerization or curing of monomer and oligomer layers is also described in U.S. Pat. Nos. 4,842,893, 4,954,371 and 5,032,461. Alternately, an oligomer or low molecular weight polymer can solidify simultaneously with cooling. For oligomers or low MW polymers that are solid at room temperature, curing may not be required as described in U.S. Pat. No. 6,270,841 that is incorporated herein by reference. Alternatively a sol-gel solution can be cured by the addition of heat to the coating film.

[0052] After depositing the intermediate organic or inorganic layer, the coated substrate layer then passes to metallization system 32 , where the metal layer is deposited on the solidified and optionally cured organic or inorganic layer. When a resistive metal evaporation system is used, the metallization system is continually provided with a source of metal from wire feed 44.

[0053] Following the metallization step, the outer organic or inorganic coating layer is deposited in a similar process as described above for the intermediate polymer layer using evaporator 128 , monomer reservoir 140 , ultrasonic atomizer 142 , and radiation curing means 130 . The composition of the outer organic or inorganic coating layer can be the same or different than the intermediate organic or inorganic coating layer. Optionally, a metal, organic coated or in-organic coated side of the substrate layer can be plasma treated prior to depositing an additional organic, inorganic or metal coating layer thereon. [0054] The thickness of the coating is controlled by the line speed and vapor flux of the flash evaporator used in the vapor deposition process. As the coating thickness increases, the energy of the electron beam must be adjusted in order for the electrons to penetrate through the coating and achieve effective polymerization. For example, an electron beam at 10 kV and 120 mA can effectively polymerize acrylate coatings up to 2 μιη thick.

[0055] If more than one metal layer and/or more than two organic or inorganic layers are desired, additional flash evaporation apparatuses and metallization stations can be added inside the vacuum chamber. Alternately, a substrate layer can be coated in a first pass in the apparatus shown in FIG. 1 , followed by removing the coated substrate and running it in a second pass through the apparatus. Alternately, a separate apparatus can be used for the metallization and organic or inorganic coating steps.

[0056] Coatings can be applied on the reverse side of the composite through use of a second rotating drum 16 that can be added within vacuum chamber 12 , with additional plasma treatment units 36 , monomer

evaporators 28 , 128 , radiation curing means 30 , 130 and metallization system 32 , which can be operated independently as desired. Such a dual- drum coating system is illustrated in FIG. 1 of WO 98/18852, which is incorporated herein by reference.

[0057] It is preferred that an organic or in-organic coating is deposited on a metal layer prior to removing the coated substrate from the vacuum chamber to prevent significant oxidation of the metal layer. It is most preferred to deposit the organic or in-organic coating layer(s) and metal layer(s) in a single pass to minimize the processing cost.

[0058] At any part of the above process, the stretchable substrate is placed in the path of the coating and plasma treatment parts of the machinery in a way that controls the stretch in both the width (weft) and the length (warp) of the substrate. This can occur in a number of ways including the two detailed below.

[0059] Before width control, the substrate first passes over a scroll roller to ensure that the substrate is open in its width. The amount of scroll rolling required will depend on the way that the substrate is presented to the scroll roller. If it is drawn directly from a roll and passed over the scroll roller then it will not require as much scroll intervention as a substrate coming from a roll some distance away or from an unrolled substrate. Automated width (weft) straitening by bowed rollers could also be part of the process just before scroll rolling if required. For substrates that feature a textile fabric, after scroll rolling, each selvedge could be passed through either rotating selvedge un-curler or selvedge uncurling plates or another method of selvedge uncurling. The substrate is then ready to be placed onto the method of width (warp) and length (weft) control.

[0060] A preferred method of width (weft) control is to place the open width substrate onto a belt of the same width (or wider) that provides resistance to the surface of the substrate. This resistance stops the substrate from sliding over its surface and curling on the edges. The resistance could be caused by surface roughness and/or a pile like structure and/or an adhesive and/or a static treatment. An example of a suitable pile like structure is a velour fabric. The fabric of the belt can then be directed around the treatment drum so that the substrate is presented to the treatment zones in the standard format detailed in this document.

[0061] Another preferred method of length (weft) control is to place the substrate onto a pinned or clipped belt. This belt would be similar to or the same as those used in fabric drying equipment. The equipment to place the substrate onto the belt would be similar to or the same as that used in this equipment and would include underfeed and overfeed devices on either edge of the edge of the substrate. The distance between the pin frames could also be increased or decrease to allow control of the level of stretch applied to the fabric as it goes through the treatment zone.

[0062] The metalized composite substrates of the present invention are especially suitable for use in apparel or outdoor equipment such as tents or sleeping bags. The highly reflective metalized surface of the composite substrate provides a low emissivity surface that enhances the performance of the apparel and reduces heat loss from the body by reflecting body heat back in the system. Additional benefits include shielding the body from excessive heat during the summer months.

[0063] Fig. 2a illustrates an example method 200 according to aspects of the invention. It is understood that the various steps and materials described may be performed and comprised in a way consistent with any part of this disclosure.

[0064] In a step 202, a stretchable porous substrate is provided. The stretchable porous substrate can be comprised in any way consistent with the disclosure herein.

[0065] In step 204, the stretchable porous substrate is stretched. The stretching may be in the warp or weft direction, or both.

[0066] In a step 206, a coating comprised of an infrared-reflective material such as a metal, organic material, or inorganic material is deposited on one or both surfaces of the substrate.

[0067] In a optional step 208, an additional infrared-reflective, metal, organic, or inorganic coating is deposited on one or both surfaces of the substrate, either on the substrate itself, or over previous coatings. This step may be repeated a desired number of times in a desired order to contribute desired properties and functionalities to a composite. Optionally, more than one coating can be applied simultaneously.

[0068] In a step 210, the substrate is unstretched.

[0069] Fig. 2b illustrates another example method 250 according to aspects of the invention, which incorporates a vacuum and plasma treatment. It is understood that the various steps and materials described may be performed and comprised in a way consistent with any part of this disclosure.

[0070] In a step 252, a stretchable porous substrate is provided. The stretchable porous substrate can be comprised in any way consistent with the disclosure.

[0071] In a step 254, the stretchable porous substrate is placed within a vacuum chamber. The vacuum chamber is evacuated to any desired pressure as discussed further herein.

[0072] In a step 256, the stretchable porous substrate is stretched. The stretching may be in the warp or weft direction, or both.

[0073] In an optional step 258, the stretchable porous substrate is treated by exposure to a plasma. Optionally, an exposure to plasma can also or alternatively take place prior to stretching, and/or after a later deposition step.

[0074] In a step 260, a coating comprised of an infrared-reflective material such as a metal, organic material, or inorganic material is deposited on one or both surfaces of the substrate. [0075] In an optional step 262, an additional metal, organic, or inorganic coating is deposited on one or both surfaces of the substrate, either on the substrate itself, or over previous coatings. This step may be repeated a desired number of times in a desired order to contribute desired properties and functionalities to a composite. Optionally, more than one coating can be applied simultaneously

[0076] In a step 264, the substrate is unstretched.

[0077] In a step 266, the substrate is removed from the vacuum chamber.

[0078] Fig. 3 illustrates an example method 300 according to aspects of the invention.

[0079] In step 301 , a stretchable porous substrate is provided. The stretchable porous substrate can be comprised in any way consistent with the disclosure.

[0080] In a step 302, the stretchable porous substrate is placed within a vacuum chamber. The vacuum chamber is evacuated to any desired pressure as discussed further herein.

[0081] In an optional step 318, the stretchable porous substrate is treated by exposure to a plasma. Optionally, an exposure to plasma can also or alternatively take place after stretching, and/or after one or more deposition steps.

[0082] In an optional step 304, the substrate is bonded to a nonporous substrate. [0083] In an optional step 306, the substrate is bonded to a vapor permeable, substantially liquid impermeable, film or membrane.

[0084] In a step 308, the stretchable porous substrate is stretched. The stretching may be in the warp or weft direction, or both.

[0085] In a step 310, a coating comprised of an infrared-reflective material such as a metal, organic material, or inorganic material is deposited on one or both surfaces of the substrate.

[0086] In an optional step 320, the coating is cured. Curing may be performed by exposure to heat, ultraviolet light, an electron beam, or other suitable curing consistent with this disclosure. Optionally, a curing step may be performed after additional subsequent deposition steps.

[0087] In a step 312 an additional infrared-reflective, metal, organic, or inorganic coating is deposited on one or both surfaces of the substrate, either on the substrate itself, or over previous coatings. This step may be repeated a desired number of times in a desired order to contribute desired properties and functionalities to a composite. Optionally, more than one coating can be applied simultaneously.

[0088] In a step 314 the substrate is unstretched.

[0089] In a step 316 the substrate is removed from the vacuum chamber.

[0090] It should be understood that the steps of the example methods according to aspects of the invention which have been described with respect to figures 2a, 2b, and 3 may be rearranged in any way that is consistent with any part of this disclosure without departing from the essence of the invention, for example, to create composites having a different ordering and

arrangement of materials, and/or different materials.

[0091] FIG. 4 illustrates an example reflective material 400 which may be fabricated according to aspects of the invention. A coating 401 , shown in cross section as applied to the fibres 402 of the supporting fabric may be fabricated using the apparatus more fully described with respect to FIG. 1 . This reflective coating 401 effectively applies to one side of the textile fibres 402. In this preferred embodiment the reflective layer is one that is comprised of a metallic material, preferably aluminium, applied to the fibres of a supporting fabric via a plasma vacuum deposition method. In this case the coating 401 to the base fabric fibres 402 is very thin, typically 10nm to 200nm, and can be coated to one side of the fabric without significantly impeding the fabrics handle, drape, air and moisture transport properties.

[0092] FIG. 5a and 5b illustrate example composite materials which may be fabricated according to aspects of the invention.

[0093] In Fig. 5a, Composite 500 comprises an outer weather layer 520 laminated to a reflective layer 521. Fig. 5b illustrates composite 550, which comprises rearrangement of the same material layers shown in Fig. 5a.

[0094] In Fig. 5a, the outer weather layer 520 is made up of an outer fabric 501 combined with a watertight, water-vapour-permeable membrane 503. The reflective layer 521 is made up of a supporting fabric 502 that is metalized 504. Layer 502 is metalized onto 504 per the vacuum plasma vapour deposition method described herein. In Figure 5a the metallization 504 is facing the membrane 503 and in figure 5b the metallization 504 is facing from the membrane 503 away upon lamination or bonding. [0095] With the metallization 504 facing the membrane 503 as in Fig 5a, the metallization 504 is more protected from convection, helping to minimize conductive heat transfer. With the metallization 504 facing away from the membrane 503 as in Fig 5b, the emissivity of the composite laminate is higher helping to improve heat reflection. In both constructions of Fig 5a and Fig 5b the composite laminate can be constructed to be a durable, watertight, heat reflective material with good water-vapour-permeability.

[0096] In the various compositions, layers of material within any given layer can be attached to each other either by an adhesive (breathable adhesive if necessary), mechanical bonding (or stitch bonding), lamination (flame or adhesive lamination, for example), welding or a combination of these applications or coated using either atmospheric or vacuum plasma deposition.

[0097] Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment, but may.

[0098] Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.

[0099] Similarly it should be appreciated that in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment.

[00100] Thus, the claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of this invention. Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination. In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practiced without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

[00101] Although the present invention has been described with particular reference to certain preferred embodiments thereof, variations and modifications of the present invention can be effected within the spirit and scope of the following claims.