Waterproof Vapor-Permeable Multilayer Article

Abstract

A waterproof vapor-permeable multilayer article, comprising at least one first layer made of a material that is vapor-permeable and microporous and is at least partially hygroscopic or can assume hygroscopic characteristics over time, and at least one second layer that is waterproof and vapor-permeable.

1 - 38 . (canceled)  
     
     
         39 . A waterproof vapor-permeable multilayer article, comprising: 
 at least one first layer made of a material that is vapor-permeable and microporous, said first layer material being further selected from a group comprising materials that are at least partially hygroscopic and material that can assume hygroscopic characteristics over time; and    at least one second layer that is waterproof and vapor-permeable.    
     
     
         40 . The multilayer article according to  claim 39 , wherein said at least one first layer comprises a base of polyolefin and a filler made of filler particles.  
     
     
         41 . The multilayer article according to  claim 40 , wherein the molecular weight of said polyolefin is at least 500,000 g/mole.  
     
     
         42 . The multilayer article according to  claim 41 , wherein the molecular weight of said polyolefin is between 4×10 6  g/mole and 7×10 6  g/mole.  
     
     
         43 . The multilayer article according to  claim 40 , wherein said polyolefin is constituted by a material selected from a group consisting of isotactic polypropylene and polyethylene.  
     
     
         44 . The multilayer article according to  claim 40 , wherein said filler is silicon dioxide SiO 2 .  
     
     
         45 . The multilayer article according to  claim 44 , wherein an average diameter of the filler particles of silicon dioxide SiO 2  is substantially between 0.01 pm and 20 μm, while an average surface area of said fillers is substantially between 30 m 2 /g and 950 m 2 /g.  
     
     
         46 . The multilayer article according to  claim 44 , wherein an average surface area of said filler particles is at least 100 m 2 /g.  
     
     
         47 . The multilayer article according to  claim 39 , wherein said at least one first layer made of microporous material has a pore size of less than 1 μm in diameter.  
     
     
         48 . The multilayer article according to  claim 47 , wherein more than 50% of the pores of said at least one first layer made of microporous material have a diameter of less than 0.5 μm.  
     
     
         49 . The multilayer article according to  claim 48 , wherein the porosity of said at least one first layer made of microporous material is at least 50%.  
     
     
         50 . The multilayer article according to  claim 39 , wherein said at least one first layer made of microporous material has a thickness comprised between 200 μm and 1.5 cm.  
     
     
         51 . The multilayer article according to  claim 50 , wherein said at least one first layer made of microporous material has a thickness between 200 μm and 600 μm.  
     
     
         52 . The multilayer article according to  claim 39 , wherein said at least one first layer is constituted by a microporous membrane that is available on the market.  
     
     
         53 . The multilayer article according to  claim 39 , wherein said at least one second waterproof vapor-permeable layer is constituted by a polypropylene-based microporous hydrophobic material.  
     
     
         54 . The multilayer article according to  claim 53 , wherein the polypropylene of said microporous hydrophobic material is an isotactic homopolymer.  
     
     
         55 . The multilayer article according to  claim 53 , wherein said at least one second layer is constituted by a hydrophobic membrane that is available on the market.  
     
     
         56 . The multilayer article according to  claim 39 , wherein said at least one second layer is composed of a polymer based on fluoropolymer or polysiloxane, said at least one second layer adhering to said first layer by spreading or immersing said first layer in a bath of said polymer.  
     
     
         57 . The multilayer article according to  claim 56 , wherein said fluoropolymer is a material that is available on the market.  
     
     
         58 . A method for manufacturing a multilayer article as set forth in  claim 39 , consisting of: 
 preparing a solution or dispersion of a basic polymeric mix for a first layer in a volatile organic liquid with low surface tension, in order to produce a spreading solution that has a certain viscosity;    applying said solution by spreading to a surface of a second layer, which acts as a backing, in order to form a coating layer on the surface thereof;    evaporating volatile components of the spread in order to promote cross-linking reaction of the spread surface; and    drying the coating in order to remove the residual humidity.    
     
     
         59 . A method for producing a multilayer article as set forth in  claim 39 , which consists of coupling a first layer and a second layer by lamination of one of said layers onto the other.  
     
     
         60 . A method for producing a multilayer article as set forth in  claim 39 , which consists of coupling a first layer in sheet form to a second layer, also in sheet form, by any of an adhesive spot application, by ultrasound and by high-frequency welding.  
     
     
         61 . The multilayer article as set forth in  claim 39 , comprising the step of providing at least one second layer of material that is constituted by a film obtained by way of a plasma deposition treatment.  
     
     
         62 . The multilayer article of  claim 61 , wherein the step for plasma deposition treatment is carried out by working in high-vacuum cold plasma conditions.  
     
     
         63 . The multilayer article of  claim 62 , wherein said step for plasma deposition treatment is carried out by using a radiofrequency generator so that an electrical field in the treatment oscillates with a frequency substantially between 13 MHz and 14 MHz.  
     
     
         64 . The multilayer article according to  claim 63 , wherein said step for plasma deposition treatment is carried out by using a radiofrequency generator so that an electrical field in the treatment oscillates with a frequency on the order of 13.56 MHz.  
     
     
         65 . The multilayer article of  claim 64 , wherein the step for plasma deposition treatment is carried out by using a power of the electrical field applied in the treatment that is substantially between 50 watts and 700 watts.  
     
     
         66 . The multilayer article of  claim 65 , wherein the duration of said plasma deposition treatment for a siloxane-based monomer is between 160 and 600 seconds.  
     
     
         67 . The multilayer article according to  claim 66 , wherein the duration of said plasma deposition treatment for a siloxane-based monomer is substantially equal to 420 seconds.  
     
     
         68 . The multilayer article according to  claim 67 , wherein the level of vacuum in said plasma deposition treatment is substantially between 10 −1  mbar and 10 −5  mbar.  
     
     
         69 . The multilayer article according to  claim 61 , wherein the step for plasma deposition treatment is carried out by working in high-vacuum cold plasma conditions and by using a radiofrequency generator so that an electrical field in the treatment oscillates with a frequency on the order of 13.75 MHz, with an applied electrical field power of 300-500 watts, and a vacuum level comprised between 10 −1  and 10 −5  mbar.  
     
     
         70 . The multilayer article of  claim 69 , wherein the plasma deposition precursor material is a siloxane-based monomer.  
     
     
         71 . The multilayer article according to  claim 69 , wherein the plasma deposition precursor material is an oil-repellent and water-repellent fluoropolymer.  
     
     
         72 . The multilayer article of  claim 69 , wherein the material of said at least one second layer is a polysiloxane.  
     
     
         73 . The multilayer article according to one of  claim 69 , wherein the material of said at least one second layer is an oil-repellent and water-repellent fluoropolymer.  
     
     
         74 . The multilayer article of  claim 73 , wherein said fluoropolymer is a material available on the market.  
     
     
         75 . A method for producing a multilayer article according to  claim 72 , comprising the steps of: 
 loading the first layer to be coated into a reaction chamber;    bringing the reaction chamber to a preset vacuum pressure;    starting plasma generating electrical discharge;    injecting vaporized precursor monomer into said reaction chamber; and    waiting for a preset deposition time.    
     
     
         76 . A production method according to  claim 75 , comprising a pretreatment step that consists of the surface cleaning of said first layer by subjecting it to an inert gas that is injected into said reaction chamber.