Disposable,moisture vapour permeable, liquid impermeable mattress cover having an improved structure for increased stability

Abstract

The present invention relates to a disposable mattress cover which is moisture vapour permeable and liquid impermeable and comprises an improved liquid impermeable formed structure having an enhanced moisture vapour permeability and comprising preferred thermoplastic compositions which can provide a better stability of the mattress cover in use. The disposable mattress cover of the present invention can find a variety of applications wherein moisture vapour permeability combined with liquid imperviousness are desirable, combined with stability in use.

What is claimed is:  
     
         1 . A disposable moisture vapor permeable and liquid impermeable mattress cover, said mattress cover comprising a moisture vapor permeable and liquid impermeable structure, said structure comprising a thermoplastic composition intended for direct contact with a mattress; 
 wherein said thermoplastic composition comprises 
 (a) from about 10% to about 80% by weight of said thermoplastic composition, of a thermoplastic polymer or a mixture of polymers selected from the group consisting of: polyurethanes, poly-ether-amides block copolymers, polyethylene-acrylic acid copolymers, polyethylene oxide, polyethylene oxide copolymers, ethylene acrylic ester copolymers, poly lactide, poly lactide copolymers, polyamides, polyester block copolymers, sulfonated polyesters, poly-ether-ester block copolymers, poly-ether-ester-amide block copolymers, polyacrylates, polyacrylic acids and derivatives thereof, ionomers, polyethylene-vinyl acetate with a vinyl acetate content of greater than about 28% by weight, polyvinyl alcohol, polyvinyl alcohol copolymers, polyvinyl ethers, polyvinyl ether copolymers, poly-2-ethyl-oxazoline and derivatives thereof, polyvinyl pyrrolidone, polyvinyl pyrrolidone copolymers, thermoplastic cellulose derivatives and mixtures thereof;  
 (b) from about 20% to about 90% by weight of said thermoplastic composition, of a plasticiser or mixture of plasticisers selected from the group consisting of: 
 citric acid esters, tartaric acid esters, glycerol, glycerol esters, adipates, sebacates, sorbitol, epoxidized vegetal oils, polymerized vegetal oils, polyols, phthalates, liquid polyesters, glycolates, p-toluene sulfonamide, p-toluene sulfonamide derivatives, glycols, polyglycols, sorbitan esters, phosphates, monocarboxylic fatty acids (C 8 -C 22 ), monocarboxylic fatty acid (C 8 -C 22 ) derivatives and mixtures thereof;  
 
 (c) from about 2% to about 60% by weight of said thermoplastic composition, of a tackifier resin or mixture of tackifier resins selected from the group consisting of: rosin, rosin esters, terpene-phenolic resins, aromatic resins and mixtures thereof.  
   
     
     
         2 . A disposable, moisture vapor permeable and liquid impermeable mattress cover according to  claim 1 , wherein said thermoplastic composition comprises from about 25% to about 70% of said thermoplastic polymer or mixture of polymers.  
     
     
         3 . A disposable, moisture vapor permeable and liquid impermeable mattress cover according to  claim 1 , wherein said thermoplastic composition comprises from about 30% to about 75% of said plasticizer or mixture of plasticizers.  
     
     
         4 . A disposable, moisture vapor permeable and liquid impermeable mattress cover according to  claim 1 , wherein said thermoplastic composition comprises from about 5% to about 50% of said tackifier resin or mixture of tackifier resins.  
     
     
         5 . A disposable, moisture and vapor permeable and liquid impermeable mattress cover according to  claim 1 , wherein said layer of thermoplastic composition is applied onto a substrate, said substrate being moisture and vapor impermeable.  
     
     
         6 . A disposable, moisture and vapor permeable and liquid impermeable mattress cover according to  claim 1 , wherein said blend of tackifier resins comprises from about 0% to about 20% by weight of said blend of tackifier resins, of a resin or blend of resins having a softening point of less than about 25° C., and from about 80% to about 100%, by weight of said blend of tackifier resins, of a resin or blend of resins having a softening point of at least about 70° C., said softening points measured according to the Ring and Ball ASTM E28 method.  
     
     
         7 . A disposable, moisture and vapor permeable and liquid impermeable mattress cover according to  claim 1 , wherein said blend of tackifier resins comprises from about 2% to about 15% by weight of said blend of tackifier resins, of a resin or blend of resins having a softening point of less than about 25° C., and from about 85% to about 98%, by weight of said blend of tackifier resins, of a resin or blend of resins having a softening point of at least about 70° C., said softening points measured according to the Ring and Ball ASTM E28 method.  
     
     
         8 . A disposable, moisture and vapor permeable and liquid impermeable mattress cover according to  claim 1 , wherein said layer of said thermoplastic composition is liquid impervious and has a water vapor transmission rate (WVTR) of at least about 300 g/m 2 ·24 h with a thickness of said layer of at least about 0.5 μm.