Sulfonated substantiallly random interpolymer-based absorbent materials

Abstract

The present invention pertains to absorbent polymer composition comprising A) one or more sulfonated substantially random interpolymers comprising repeating units derived from; a) ethylene and/or one or more alpha olefins; b) one or more sulfonated vinyl or vinylidene aromatic monomers; c) one or more vinyl or vinylidene aromatic monomers, or a combination of one or more vinyl or vinylidene aromatic monomers and one or more sterically hindered aliphatic or cycloaliphatic vinyl or vinylidene monomers; and optionally, B) one or more polymers other than said sulfonated substantially random interpolymer. Uses of the compositions include the preparation of absorbent foams, fibers films and membranes for the preparation of absorbent articles for personal hygiene. These include diapers, sanitary napkins adult incontinence pads, and highly absorbent wipes, and dust pickups.

What is claimed is:  
     
         1 . A bicomponent fiber comprising an inner core and an outer sheath; wherein said inner core or said outer core sheath can comprises one or more sulfonated substantially random interpolymers wherein said bicomponent fiber can absorb at least 50% of the total weight of the sulfonated substantially random interpolymers of water.  
     
     
         2 . A bicomponent fiber comprising an inner core and an outer sheath of  claim 2  wherein; 
 (A) said inner core comprises from 25 to 80 wt percent (based on the total fiber weight) of one or more propylene hompolymers or copolymers; and  
 (B) said outer sheath comprises from 20 to 75 wt percent (based on the total fiber weight) of a composition comprising 
 1) from 10 to 100 wt percent of one or more sulfonated substantially random interpolymers comprising units derived from; 
 a) from 35 to 98.5 mol percent ethylene and/or one or more alpha olefins;  
 b) from 1.5 to 65 mol percent of one or more sulfonated vinyl aromatic monomers which are mono substituted with either a sulfonic acid group or a sulfonic acid salt;  
 c) from 0 to 63.5 mol percent of one or more vinyl aromatic monomers; and  
 
 2) from 0 to 90 wt percent of one or more polymers other than said sulfonated substantially random interpolymer,  
 
 wherein said bicomponent fiber is able to absorb at least 50% of the total sulfonated substantially random interpolymer of the outer sheath weight of water.  
 
     
     
         3 . A bicomponent fiber of  claim 2  wherein; 
 A) said inner core comprises from 25 to 80 wt percent (based on the total fiber weight) of one or more propylene hompolymers or copolymers; and  
 B) said outer sheath comprises from 20 to 75 wt percent (based on the total fiber weight) of a composition comprising 
 1) from 10 to 50 wt percent of one or more sulfonated substantially random interpolymers comprising units derived from; 
 a) from 35 to 98.5 mol percent ethylene and/or one or more alpha olefins;  
 b) from 1.5 to 65 mol percent of one or more sulfonated vinyl aromatic monomers which are mono substituted with either a sulfonic acid group or a sulfonic acid salt;  
 c) from 0 to 63.5 mol percent of one or more vinyl aromatic monomers; and  
 
 2) from 50 to 90 wt percent of one or more polymers other than said sulfonated substantially random interpolymer.  
 
 
     
     
         4 . The bicomponent fiber of claim claims  1 - 3 , wherein the sheath has a higher softening and melting point than the core material.  
     
     
         5 . The bicomponent fiber of claim claims  1 - 3 , wherein the sheath material has a lower softening and melting point than the core material.  
     
     
         6 . An absorbent fabricated article comprising 
 1) one or more sulfonated substantially random interpolymers comprising units derived from; 
 a) from 35 to 98.5 mol percent ethylene and/or one or more alpha olefins;  
 b) from 1.5 to 65 mol percent of one or more sulfonated vinyl aromatic monomers;  
 c) from 0 to 63.5 mol percent of one or more vinyl aromatic monomers; and  
   2) one or more other polymers,    wherein said absorbent fabricated article is able to absorb at least 50% of the total polymer weight of water.    
     
     
         7 . The absorbent fabricated article of  claim 6  is in the form of a diaper, sanitary napkins or an adult incontinence article.  
     
     
         8 . The absorbent fabricated article of  claim 7 , wherein the article comprises at least one acquisition distribution layer, a binder material or a plurality of binder fibers, an absorbent core material, or a topsheet/backsheet.  
     
     
         9 . The absorbent fabricated article of  claim 8 , wherein the absorbent core material comprises multilobal shaped fibers to provide wicking.  
     
     
         10 . The absorbent fabricated article of  claim 8 , wherein the acquisition distribution layer comprises a foam material or nonwoven material.  
     
     
         11 . The absorbent fabricated article of  claim 8 , wherein the acquisition distribution layer comprises a foam material and a nonwoven material.  
     
     
         12 . The absorbent fabricated article of claim claims  10  and  11 , wherein the nonwoven material comprises carded, air laid, or wet laid structures from staple fibers.  
     
     
         13 . The absorbent fabricated article of claim claims  10  and  11 , wherein the nonwoven material comprises curly, self crimping, bicomponent, multicomponent, tip trilobal, bonded multiconstituent, microfiber, capillary or hollow fibers.  
     
     
         14 . The absorbent fabricated article of claim claims  10  and  11 , wherein the nonwoven material comprises surface treated fibers.  
     
     
         15 . The absorbent fabricated article of  claim 14 , wherein the surface treated fibers are prepared by a surface treatment which includes plasma, corona, sulfonation or azide treatment.  
     
     
         16 . A method of absorbing an aqueous liquid comprising the steps of: 
 placing the fabricated article of  claim 6  in contact with an aqueous liquid.