Absorbent articles with biocompostable properties

Abstract

Disclosed is an absorbent article with biocompostable properties, such as a baby diaper or adult incontinence product. Particularly, the present invention is directed to a biocompostable absorbent sanitary article including a blend of synthetic and bio-based superabsorbent polymers with a high degree of biocompostability. The sanitary article comprises, in one embodiment, at least a top layer, a back layer, and absorbent core, wherein the absorbent core includes a superabsorbent polymer, and wherein at least the superabsorbent polymer is biocompostable.

The invention claimed is: 
     
         1 . An absorbent article, comprising:
 a fluid-permeable top layer;   a fluid-resistant back layer; and   an absorbent core;   wherein the absorbent core includes an absorbent fiber and a superabsorbent polymer (SAP);   wherein the SAP includes a charge modified starch-based biopolymer;   wherein a biobased carbon content of the charge modified starch-based biopolymer is at least approximately 50%;   wherein the charge modified starch-based biopolymer is not a dermal irritant; and   wherein the charge modified starch-based biopolymer has a Centrifuge Retention Capacity (CRC) of at least 16 g/g, and an Absorbency Under Load (AUL) of at least 6 g/g at 0.7 psi.   
     
     
         2 . The article of  claim 1 , wherein the charge modified starch-based biopolymer has a moisture content of less than 20% by weight. 
     
     
         3 . The article of  claim 1 , wherein the charge modified starch-based biopolymer includes a negatively charged moiety. 
     
     
         4 . The article of  claim 1 , wherein the charge modified starch-based biopolymer has a charge density of at least 3 meq/g. 
     
     
         5 . The article of  claim 1 , wherein the charge modified starch-based biopolymer is not a graft polymer. 
     
     
         6 . The article of  claim 1 , wherein at least 85% of the particle sizes of the charge modified starch-based biopolymer are between 100 and 850 microns. 
     
     
         7 . The article of  claim 1 , wherein the charge modified starch-based biopolymer is made from corn starch, potato starch, pea starch, tapioca starch, wheat starch, cassava starch, rice starch, sorghum starch, barley starch, or combinations thereof. 
     
     
         8 . The article of  claim 1 , wherein alcohol is not used during the charge modification step in making the charge modified starch-based biopolymer. 
     
     
         9 . The article of  claim 1 , wherein the absorbent article is a baby diaper, an adult incontinence product, a feminine hygiene product, or an absorbent dressing. 
     
     
         10 . An absorbent article, comprising:
 a fluid-permeable top layer;   a fluid-resistant back layer; and   an absorbent core;   wherein the absorbent core includes an absorbent fiber and a superabsorbent polymer (SAP);   wherein the SAP includes a modified biopolymer;   wherein a biobased carbon content of the modified biopolymer is at least approximately 50%;   wherein the modified biopolymer exhibits no cytotoxicity; and   wherein the modified biopolymer has a Centrifuge Retention Capacity (CRC) of at least 16 g/g, an Absorbency Under Load (AUL) of at least 6 g/g at 0.7 psi, and a Free Swell Capacity (FSC) of at least 25 g/g in a saline solution.   
     
     
         11 . The article of  claim 10 , wherein alcohol is not used during the charge modification step in making the modified biopolymer. 
     
     
         12 . The article of  claim 10 , wherein the modified biopolymer is not a graft polymer. 
     
     
         13 . The article of  claim 10 , wherein the modified biopolymer is synthesized from a biopolymer selected from a group including starches, chitosans, hemicelluloses, lignins, celluloses, chitins, alginates, dextrans, pullanes, polyhydroxyalkanoates, fibrins, cyclodextrins, proteins, polysaccharides, polylactic acids, or combinations thereof. 
     
     
         14 . An absorbent article, comprising:
 a fluid-permeable top layer;   a fluid-resistant back layer; and   an absorbent core;   wherein the absorbent core includes an absorbent fiber and a superabsorbent polymer (SAP);   wherein the SAP does not include a graft polymer or a non-biobased polymer;   wherein the SAP includes a starch-based biopolymer, wherein the starch-based biopolymer exhibits no cytotoxicity and is not a dermal irritant.   
     
     
         15 . The article of  claim 14 , wherein a biobased carbon content of the SAP is at least approximately 50%. 
     
     
         16 . The article of  claim 14 , wherein the starch-based biopolymer has a Centrifuge Retention Capacity (CRC) of at least 20 g/g and an Absorbency Under Load (AUL) of at least 8 g/g at 0.7 psi in a saline solution. 
     
     
         17 . The article of  claim 14 , wherein the density of the absorbent core is at least 0.15 g/cm 3 . 
     
     
         18 . The article of  claim 14 , wherein a ratio of the SAP to fluff in the absorbent core is between approximately 70% SAP to approximately 30% fluff and approximately 45% SAP to approximately 55% fluff. 
     
     
         19 . The article of  claim 14 , wherein the components of the absorbent core degrade 90% within 180 days in standard aerobic composting conditions according to ASTM 5338. 
     
     
         20 . The article of  claim 14 , wherein the absorbent core is operable to be inserted into at least one sleeve, at least one pouch, and/or at least one retaining element, wherein the absorbent core is removable from the at least one sleeve, the at least one pouch, and/or the at least one retaining element.