Water dispersible, salt sensitive nonwoven materials

Abstract

The present invention is directed to a non-woven material having an emulsion binder, which is dispersible in water, yet non-dispersible in aqueous solutions containing 0.5 weight percent or more of an inorganic salt. The water-dispersible polymer comprises from 1 to 100 percent by weight of a hydrophilic monomer and from 0 to 99 percent by weight of at least one non-hydrophilic monomer, wherein a film formed from said polymer has a Tg of from −40 to 105° C. The dispersible non-woven material is useful in forming disposable articles which can be disposed of by flushing down a toilet.

What is claimed is:  
     
         1 . A non-woven material comprising 
 c) a web of fibers; and    d) an aqueous emulsion binder comprising a water-dispersible polymer which is non-dispersible in aqueous solutions containing 0.5 weight percent or more of an inorganic salt, wherein said water-dispersible polymer comprises from 1 to 100 percent by weight of a hydrophilic monomer and from 0 to 99 percent by weight of at least one non-hydrophilic monomer, wherein a film formed from said polymer has a Tg of from −40 to +105° C.    
     
     
         2 . The non-woven material of  claim 1  wherein said fibers have a length of less than 5 cm.  
     
     
         3 . The non-woven material of  claim 1  wherein said fibers have a length of less than 2 cm.  
     
     
         4 . The non-woven material of  claim 1  comprising 50 to 98 percent by weight of fibers.  
     
     
         5 . The non-woven material of  claim 1  comprising 70 to 85 percent by weight of fibers.  
     
     
         6 . The non-woven material of  claim 1  wherein said material has a binder add-on of from 2 to 50 percent by weight.  
     
     
         7 . The non-woven material of  claim 1  wherein said material has a wet tensile strength in 3 percent aqueous inorganic salt solution of at least 100 g/in, and a wet tensile strength in tap water of at least 40 g/in.  
     
     
         8 . The non-woven material of  claim 1  wherein said binder further comprises at least one component selected from the group consisting of plasticizers, tackifiers, fillers, humectants, surfactants, salts, fragrances, pigments, titanium dioxide, and encapsulated components.  
     
     
         9 . The non-woven material of  claim 1  having a web basis weight of from 20 to 200 gsm.  
     
     
         10 . A non-woven article comprising the non-woven material of  claim 1 .  
     
     
         11 . The non-woven article of  claim 9  further comprising a lotion containing at least one ingredient selected from the group consisting of sodium chloride solution, preservatives, boric acid, bicarbonates, moisturizers, emollients, surfactants, humectants, alcohols, water, and fragrances.  
     
     
         12 . The non-woven article of  claim 9  further comprising at least 0.5 percent by weight of inorganic salt, or a mixture of inorganic salts.