Disposable, moisture vapour permeable, liquid impermeable covering sheet for bedding articles having an improved comfort

Abstract

Disposable covering sheet for bedding articles that is moisture vapour permeable and liquid impermeable and comprises at least a moisture vapour permeable fibrous layer and a liquid impermeable but moisture vapour permeable film layer of preferred thermoplastic compositions. Use of the disposable covering sheet as, for example, a mattress or pillow cover provides increased comfort to the user. The disposable covering sheet disclosed herein can be used in a variety of applications, particularly when the benefits of moisture vapour permeability, liquid imperviousness, disposability and increased in-use comfort are desired.

What is claimed is:  
     
         1 . A disposable, moisture vapour permeable, liquid impermeable, covering sheet for bedding articles, said sheet comprising: 
 a. a moisture vapour permeable fibrous layer; and    b. a liquid impermeable but moisture vapour permeable film layer of thermoplastic composition applied onto said fibrous layer;    wherein said covering sheet comprises: a water vapour transmission rate value of at least about 400 g/m 2 ·24 h; a hydrostatic water head value of at least about 1 cm; and a ratio R of the caliper, expressed in micrometers to the basis weight, expressed in g/m 2 , of at least about 2.5.    
     
     
         2 . A disposable, moisture vapour permeable, liquid impermeable, covering sheet for bedding articles according to  claim 1  wherein said thermoplastic composition comprises: 
 a. a thermoplastic hydrophilic polymer selected from the group consisting of polyurethanes, poly-ether-amides block copolymers, polyethylene-acrylic acid and polyethylene-methacrylic acid copolymers, polyethylene oxide and its copolymers, ethylene acrylic esters and ethylene methacrylic esters copolymers, poly lactide and copolymers, polyamides, polyesters and copolyesters, polyester block copolymers, sulfonated polyesters, poly-ether-ester block copolymers, poly-ether-ester-amide block copolymers, polyacrylates, polyacrylic acids and derivatives, ionomers, polyethylene-vinyl acetate with a vinyl acetate content of more than about 28% by weight, polyvinyl alcohol and its copolymers, polyvinyl ethers and their copolymers, poly-2-ethyl-oxazoline and derivatives, polyvinyl pyrrolidone and its copolymers, thermoplastic cellulose derivatives, poly-caprolactone and copolymers, poly glycolide, polyglycolic acid and copolymers, polylactic acid and copolymers, polyureas, and mixtures thereof;  
 b. optionally, a compatible hydrophilic tackifying resin having an equilibrium contact angle with water no greater than about 86 degrees; and  
 c. optionally, a blend of compatible hydrophilic tackifying resins, said blend of compatible hydrophilic tackifying resins comprising at least about 50% by weight of a tackifying resin or resins having an equilibrium contact angle with water no greater than about 86 degrees.  
 
     
     
         3 . A thermoplastic hydrophilic polymeric composition according to  claim 2 , wherein said equilibrium contact angle with water is no greater than about 84 degrees.  
     
     
         4 . A thermoplastic hydrophilic polymeric composition according to  claim 2 , wherein said equilibrium contact angle with water is no greater than about 82 degrees.  
     
     
         5 . A disposable, moisture vapour permeable, liquid impermeable covering sheet for bedding articles according to  claim 2 , wherein said thermoplastic composition further comprises a compatible plasticiser selected from the group consisting of citric acid esters, tartaric acid esters, glycerol and its esters, sucrose esters, adipates, sebacates, sorbitol, epoxidized vegetal oils, polymerised vegetal oils, polyols, phthalates, liquid polyesters, glycolates, p-toluene sulfonamide and derivatives, glycols and polyglycols and their derivatives, sorbitan esters, phosphates, monocarboxylic fatty acids (C 8 -C 22 ) and their derivatives, and mixtures thereof.  
     
     
         6 . A disposable, moisture vapour permeable, liquid impermeable, covering sheet for bedding articles according to  claim 1 , wherein said water vapour transmission rate is at least about 500 g/m 2 ·24 h.  
     
     
         7 . A disposable, moisture vapour permeable, liquid impermeable, covering sheet for bedding articles according to  claim 6 , wherein said water vapour transmission rate is at least about 600 g/m 2 ·24 h.  
     
     
         8 . A disposable, moisture vapour permeable, liquid impermeable covering sheet for bedding articles according to  claim 1 , wherein said hydrostatic water head value is at least about 10 cm.  
     
     
         9 . A disposable, moisture vapour permeable, liquid impermeable covering sheet for bedding articles according to  claim 1 , wherein said ratio R is at least about 3.5.  
     
     
         10 . A disposable, moisture vapour permeable, liquid impermeable covering sheet for bedding articles according to  claim 1 , wherein said hydrostatic water head value is at least about 10 cm, and said ratio R is at least about 3.5.  
     
     
         11 . A disposable, moisture vapour permeable, liquid impermeable, covering sheet for bedding articles according to  claim 1 , wherein said covering sheet is a disposable mattress cover or a disposable pillow cover having a rectangular shape and a surface area from about 15.0 m 2  to about 0.3 m 2 .  
     
     
         12 . A disposable, moisture vapour permeable, liquid impermeable, covering sheet for bedding articles according to  claim 11 , wherein said covering sheet is a disposable mattress cover or a disposable pillow cover having a rectangular shape and a surface area from about 8.0 m 2  to about 0.5 m 2 .  
     
     
         13 . A disposable mattress cover according to  claim 11  having a surface area from about 4.0 m 2  to about 1.0 m 2 .  
     
     
         14 . A disposable mattress cover according to  claim 13  having at least four adhesive means.