Superabsorbent surface-treated carboxylated polysaccharides and process for producing same

The superabsorbent material according to claim 1, wherein said carboxyalkylated starch exhibits a substitution degree ranging from 0.2 to 1.0.

The superabsorbent material according to claim 5, wherein said carboxyalkylated starch exhibits a substitution degree ranging from 0.4 to 0.7.

The superabsorbent material according to claim 1, wherein said carboxalkylated starch is carboxyalkylated in an aqueous alkaline medium.

A superabsorbent material comprising:

• a particle formed of a carboxyalkylated polysaccharide having a pH in a range from about 5.0 to about 10, said particle having an interior and a surface, each exhibiting a differentiated functionality;
• said interior is absorbent;
• said surface is treated with a non-crosslinking acid, such that penetration depth of said non-crosslinking acid is limited to said surface, said non-crosslinking acid induces ester linkages between polysaccharide strands at said particle surface, which imparts said particle with a sufficient structural rigidity to enable said particle to maintain a discrete particle shape when contacted with a salt solution, and said carboxyalkylated polysaccharide particle has a greater absorbance under load (AUL) of said salt solution at 0.7 psi than a comparative particle formed of the carboxyalkylated polysaccharide having a surface that is not treated with the non-crosslinking acid.

A hygiene article comprising an absorbent member, said absorbent member includes from 15% to 80% of a carboxylated polysaccharide particle, said carboxylated polysaccharide particle having an external surface treated with a non-crosslinking acid, such that penetration depth of said non-crosslinking acid is limited to said surface, and said carboxylated polysaccharide particle having a homogeneous carboxyalkylated substitution pattern.

A process of making a carboxyalkylated polysaccharide particle, comprising:

• treating a glass-like polysaccharide particle with a non-crosslinking acid, such that penetration depth of said non-crosslinking acid is limited to a surface of said glass-like polysaccharide particle, such that said non-crosslinking acid generates ester linkages between polysaccharide strands at said particle surface, which imparts said particle with a sufficient structural rigidity to enable said particle to maintain a discrete particle shape when contacted with a salt solution.