Treatment of fibrous materials using atmospheric pressure plasma polymerization

Abstract

An apparatus and method for plasma finishing of fibrous materials including paper and knitted, woven and non-woven fibrous substrates such that desired characteristics are imparted are described. The method includes depositing a monomer comprising at least one fluorocarbon monomer with chemical additives, as required, at atmospheric pressure onto the paper or knitted, woven or non-woven substrate; exposing the monomer on a single surface of the fibrous material to an inert gas, atmospheric-pressure plasma, thereby causing polymerization of the monomer species; and repeating this sequence using multiple sequential deposition and plasma discharge steps to create a layered surface having durability against abrasion for both water-based laundry methods and dry-cleaning methods, and normal wear, without affecting the feel, drape, appearance or breathability of the substrate material. The present method uses a high-power, continuously operating plasma that is 10 4 times more powerful than the prior art plasma sources utilized in the textile industry, and produces a durable finish with between 0.5 and 2 s of plasma exposure. This is sufficiently rapid to meet commercial fabric processing throughput, and repeated cleaning of the electrodes is not required.

1 - 26 . (canceled) 
     
     
         27 . An apparatus for treating a substrate with a finish having a chosen characteristic, comprising in combination:
 an evaporator for receiving at least one monomeric precursor to a polymer having said chosen characteristic in liquid form, and for generating a vapor therefrom;   an applicator for receiving the vapor of the at least one monomeric precursor and for spraying the vapor onto said substrate, thereby forming a coating thereon;   means for moving said coated substrate to a location away from said applicator; and   an inert gas atmospheric pressure plasma disposed at the location away from said applicator, for exposing said coated substrate to products generated by said plasma, whereby the at least one monomeric precursor is polymerized forming said finish having said chosen characteristic.   
     
     
         28 . The apparatus of  claim 27 , wherein said atmospheric pressure inert gas plasma comprises an rf electrode and a grounded electrode parallel thereto, and wherein the coated substrate is disposed in the vicinity of either said rf electrode or said grounded electrode. 
     
     
         29 . The apparatus of  claim 27 , wherein said atmospheric pressure inert gas plasma is generated using an rf frequency between 40 kHz and 100 MHz. 
     
     
         30 . The apparatus of  claim 27 , wherein said atmospheric pressure inert gas plasma is a continuously operating plasma. 
     
     
         31 . The apparatus of  claim 27 , wherein the inert gas is selected from the group consisting of helium, neon, argon, krypton, and xenon. 
     
     
         32 . The apparatus of  claim 27 , wherein gases selected from the group consisting of H 2 , N 2 , NH 3 , and CF 4 , are mixed with the inert gas. 
     
     
         33 . The apparatus of  claim 27 , wherein said substrate is a flexible substrate. 
     
     
         34 . The apparatus of  claim 27 , wherein said substrate is selected from the group consisting of paper and woven, non-woven, and knitted fibrous materials. 
     
     
         35 . The apparatus of  claim 27 , wherein said chosen characteristic is selected from the group consisting of oleophobicity, hydrophobicity, anti-microbial, anti-static, ultraviolet insensitivity, softness, fade resistivity, and durability. 
     
     
         36 . The apparatus of  claim 27 , wherein said at least one monomeric precursor is selected from the group consisting of fluorocarbon telomers, and aliphatic and aromatic compounds. 
     
     
         37 . The apparatus of  claim 36 , wherein said at least one monomeric precursor is selected from the group consisting of Zany TA-N, Zonyl® TM and perfluorooctyl acrylate. 
     
     
         38 . The apparatus of  claim 27 , wherein said evaporator further receives cornpositions selected from the group consisting of fatty acids, esters and materials which augment the chosen characteristic in liquid form, in addition to said at least one monomeric precursor in liquid form, and generates a vapor therefrom which is received by said applicator and sprayed onto said substrate. 
     
     
         39 . The apparatus of  claim 38 , wherein the fatty acids comprise stearic acid, wherein the esters comprise octyl acetate and methyl salicylate, and wherein the characteristic augmenting materials comprise 1,6-hexanediol diacrylate, avobenzone and oxybenzone.