Absorbent composites adapted to provide improved permeability

Abstract

Absorbent composites suitable for incorporation into the absorbent core of disposable absorbent articles. The absorbent composites include at least one particle of a superabsorbent material covered with a coating of particles. The absorbent composites are adapted to exhibit an improved Gel Bed Permeability.

1 . An absorbent composite comprising at least one particle of a superabsorbent material covered with a coating of hydrophilic and silicate particles, the absorbent composite having a Free Swell Gel Bed Permeability of at least 40×10 −8  cm 2 .  
     
     
         2 . The absorbent composite of  claim 1 , wherein the absorbent composite has a Centrifuge Retention Capacity of no less than 20 g/g.  
     
     
         3 . The absorbent composite of  claim 2 , wherein the absorbent composite has a Free Swell Gel Bed Permeability of at least 60×10 −8  cm 2 .  
     
     
         4 . The absorbent composite of  claim 2 , wherein the absorbent composite has a Free Swell Gel Bed Permeability of at least 75× 10   −8  cm 2 .  
     
     
         5 . The absorbent composite of  claim 2 , wherein the superabsorbent material is no less than 65 percent by weight of the absorbent composite.  
     
     
         6 . The absorbent composite of  claim 5 , wherein the hydrophilic and silicate particles are no more than 35 percent by weight of the absorbent composite.  
     
     
         7 . The absorbent composite of  claim 6 , wherein the hydrophilic particles are fibers.  
     
     
         8 . The absorbent composite of  claim 7 , wherein the hydrophilic particles are particles of a cellulosic material.  
     
     
         9 . The absorbent composite of  claim 7 , wherein the hydrophilic particles have a length of no less tan 50 microns; and wherein the hydrophilic particles have a length of no more than 900 microns.  
     
     
         10 . The absorbent composite of  claim 7 , wherein the hydrophilic particles have a length of no less than 100 microns; and wherein the hydrophilic particles have a length of no more than 300 microns.  
     
     
         11 . The absorbent composite of  claim 10 , wherein at least a portion of at least one of the hydrophilic particles extends outwardly from the surface of the absorbent composite.  
     
     
         12 . The absorbent composite of  claim 10 , wherein the hydrophilic particles are particles of a cellulosic material.  
     
     
         13 . The absorbent composite of  claim 12 , wherein the hydrophilic particles have a diameter of no less than 30 microns; and wherein the hydrophilic particles have a diameter of no more than 50 microns.  
     
     
         14 . The absorbent composite of  claim 6 , wherein the hydrophilic particles have a diameter of no less than 5 microns; and wherein the hydrophilic particles have a diameter of no more than 75 microns.  
     
     
         15 . The absorbent composite of claim A 7 , wherein the hydrophilic particles have a diameter of no less than 30 microns; and wherein the hydrophilic particles have a diameter of no more than 50 microns.  
     
     
         16 . The absorbent composite of  claim 15 , wherein the hydrophilic particles are particles of a cellulosic material.  
     
     
         17 . The absorbent composite of  claim 6 , wherein the silicate particles are selected from the group consisting of precipitated silica, fumed silica, silicon dioxide, zeolites, clays, vermiculite, perlite and mixtures thereof.  
     
     
         18 . The absorbent composite of  claim 17 , wherein the silicate particles have a diameter of no less than 100 microns; and wherein the silicate particles have a diameter of no more than 600 microns.  
     
     
         19 . The absorbent composite of  claim 17 , wherein the silicate particles have a diameter of no less than 150 microns; and wherein the silicate particles have a diameter of no more than 450 microns.  
     
     
         20 . An absorbent composite comprising at least one particle of a superabsorbent material covered with a coating of hydrophilic and silicate particles, the absorbent composite having a Gel Bed Permeability Under Load of at least 20×10 −8  cm 2 .  
     
     
         21 . The absorbent composite of  claim 20 , wherein the absorbent composite has a Centrifuge Retention Capacity of no less than 20 g/g.  
     
     
         22 . The absorbent composite of  claim 21 , wherein the absorbent composite has a Gel Bed Permeability Under Load of at least 25×10 −8  cm 2 .  
     
     
         23 . The absorbent composite of  claim 21 , wherein the superabsorbent material is no less than 65 percent by weight of the absorbent composite.  
     
     
         24 . The absorbent composite of  claim 23 , wherein tle hydrophilic and silicate particles are no more than 35 percent by weight of the absorbent composite.  
     
     
         25 . The absorbent composite of  claim 24 , wherein the hydrophilic particles are fibers.  
     
     
         26 . The absorbent composite of  claim 25 , wherein the hydrophilic particles are particles of a cellulosic material.  
     
     
         27 . The absorbent composite of  claim 25 , wherein the hydrophilic particles have a length of no less than 50 microns; and wherein the hydrophilic particles have a length of no more than 900 microns.  
     
     
         28 . The absorbent composite of  claim 25 , wherein the hydrophilic particles have a length of no less than 100 microns; and wherein the hydrophilic particles have a length of no more than 300 microns.  
     
     
         29 . The absorbent composite of  claim 28 , wherein at least a portion of at least one of the hydrophilic particles extends outwardly from the surface of the absorbent composite.  
     
     
         30 . The absorbent composite of  claim 28 , wherein the hydrophilic particles are particles of a cellulosic material.  
     
     
         31 . The absorbent composite of  claim 24 , wherein the hydrophilic particles have a diameter of no less than 5 microns; and wherein the hydrophilic particles have a diameter of no more than 75 microns.  
     
     
         32 . The absorbent composite of  claim 31 , wherein the hydrophilic particles are articles of a cellulosic material.  
     
     
         33 . The absorbent composite of  claim 25 , wherein the hydrophilic particles have a diameter of no less than 30 microns; and wherein the hydrophilic particles have a diameter of no more than 50 microns.  
     
     
         34 . The absorbent composite of  claim 33 , wherein the hydrophilic particles are particles of a cellulosic material.  
     
     
         35 . The absorbent composite of  claim 24 , wherein the silicate particles are selected from the group consisting of precipitated silica, fumed silica, silicon dioxide, zeolites, clays, vermiculite, perlite and mixtures thereof.  
     
     
         36 . The absorbent composite of  claim 35 , wherein the silicate particles have a diameter of no less than 100 microns; and wherein the silicate particles have a diameter of no more than 600 microns.  
     
     
         37 . The absorbent composite of  claim 35 , wherein the silicate particles have a diameter of no less than 150 microns; and wherein the silicate particles have a diameter of no more than 450 microns.  
     
     
         38 . A disposable absorbent article, the article comprising: 
 a fluid pervious topsheet;    a liquid impervious backsheet; and    an absorbent core disposed intermediate the topsheet and the backsheet, the absorbent core having an absorbent composite, the absorbent composite including at least one particle of a superabsorbent material covered with a coating of hydrophilic and silicate particles, the absorbent composite having a Free Swell Gel Bed Permeability of at least 40×10 −8  cm 2  and a Centrifuge Retention Capacity of no less than 20 g/g.    
     
     
         39 . The disposable absorbent article of  claim 38 , wherein at least one region of the absorbent core comprises the absorbent composite in a concentration of no less than 40 percent by weight of the absorbent core.  
     
     
         40 . The disposable absorbent article of  claim 38 , wherein at least one region of the absorbent core comprises the absorbent composite in a concentration of no less than 50 percent by weight of the absorbent core.  
     
     
         41 . The disposable absorbent article of  claim 38 , wherein at least one region of the absorbent core comprises the absorbent composite in a concentration of no less than 75 percent by weight of the absorbent core.  
     
     
         42 . The disposable absorbent article of  claim 38 , wherein at least one region of the absorbent core comprises the absorbent composite in a concentration of no less than 95 percent by weight of the absorbent core.  
     
     
         43 . The disposable absorbent article of  claim 38 , wherein the absorbent composite has a Gel Bed Permeability Under Load of at least 20×10 −8  cm 2 .  
     
     
         44 . The disposable absorbent article of  claim 40 , wherein the superabsorbent material is no less than 65 percent by weight of the absorbent composite.  
     
     
         45 . The disposable absorbent article of  claim 44 , wherein the hydrophilic and silicate particles are no more than 35 percent by weight of the absorbent composite.  
     
     
         46 . The disposable absorbent article of  claim 45 , wherein the hydrophilic particles are fibers.  
     
     
         47 . The disposable absorbent article of  claim 46 , wherein the hydrophilic particles are particles of a cellulosic material.  
     
     
         48 . The disposable absorbent article of  claim 46 , wherein the hydrophilic particles have a length of no less than 50 microns; and wherein the hydrophilic particles have a length of no more than 900 microns.  
     
     
         49 . The disposable absorbent article of  claim 48 , wherein the hydrophilic particles have a length of no less than 100 microns; and wherein the hydrophilic particles have a length of no more than 300 microns.  
     
     
         50 . The disposable absorbent article of  claim 49 , wherein at least a portion of at least one of the hydrophilic particles extends outwardly from the surface of the absorbent composite.  
     
     
         51 . The disposable absorbent article of  claim 50 , wherein the hydrophilic particles are particles of a cellulosic material.  
     
     
         52 . The disposable absorbent article of  claim 51 , wherein the hydrophilic particles have a diameter of no less than 30 microns; and wherein the hydrophilic particles have a diameter of no more than 50 microns.  
     
     
         53 . The disposable absorbent article of  claim 45 , wherein the hydrophilic particles have a diameter of no less than 5 microns; and wherein the hydrophilic particles have a diameter of no more than 75 microns.  
     
     
         54 . The disposable absorbent article of  claim 46 , wherein the hydrophilic particles have a diameter of no less than 30 microns; and wherein the hydrophilic particles have a diameter of no more than 50 microns.  
     
     
         55 . The disposable absorbent article of  claim 54 , wherein the hydrophilic particles are particles of a cellulosic material.  
     
     
         56 . The disposable absorbent article of  claim 45 , wherein the silicate particles are selected from the group consisting of precipitated silica, fumed silica, silicon dioxide, zeolites, clays, vermiculite, perlite and mixtures thereof.  
     
     
         57 . The disposable absorbent article of  claim 56 , wherein the silicate particles have a diameter of no less than 100 microns; and wherein the silicate particles have a diameter of no more than 600 microns.  
     
     
         58 . The disposable absorbent article of  claim 56 , wherein the silicate particles have a diameter of no less tan 150 microns; and wherein the silicate particles have a diameter of no more than 450 microns.