Absorbent composition of matter

A dry, solid, water-swellable, water-insoluble absorbent composition of matter consisting essentially of an ionic complex of

• (a) an anionic polyelectrolyte which is water-soluble in the absence of the cation of (b) and has 40-85% of its anionic groups neutralized;
• and
• (b) a polyvalent metal cation having a valence of at least 3, said cation being present in an amount within the range of 0.01-5.0 milliequivalents per gram of said polyelectrolyte, depending on said polyelectrolyte, sufficient to render said polyelectrolyte both water-insoluble and water-swellable;
• said composition further being defined as providing a gelantinous agglomerate of liquid-swollen particulate members in the presence of a quantity of body exudate, as having a film swell index in synthetic urine of at least 15, as being capable of absorbing at least about fifteen times its weight in body exudate, as capable of retaining said absorbed exudate when exposed to pressure sufficient to deform said agglomerate, and as capable of uncomplexing at an elevated pH to form said water-soluble anionic polyelectrolyte and recomplexing at a lower pH.

A dry, solid, water-swellable, water-insoluble absorbent composition of matter consisting essentially of an ionic complex of

• (a) an anionic polyelectrolyte which is water-soluble in the absence of the cation of (b);
• and
• (b) a polyvalent metal cation having a valence of at least 3, said cation being present in an amount within the range of 0.01-1.42 milliequivalents per gram of said polyelectrolyte, depending on said polyelectrolyte, sufficient to render said polyelectrolyte both water-insoluble and water-swellable;
• said composition further being defined as providing a gelatinous agglomerate of liquid-swollen particulate members in the presence of a quantity of body exudate, as having a film swell index in synthetic urine of at least 15, as being capable of absorbing at least about 15 times its weight in body exudate, as capable of retaining said absorbed exudate when exposed to pressure sufficient to deform said agglomerate, and as capable of uncomplexing at an elevated pH to form said water-soluble anionic polyelectrolyte and recomplexing at a lower pH.

A dry, solid, water-swellable, water-insoluble absorbent composition of matter consisting essentially of an ionic complex of

• (a) an anionic polyelectrolyte which is water-soluble in the absence of the cation of (b);
• and
• (b) a polyvalent metal cation of aluminum having a valence of 3, said cation being present in an amount within the range of 0.01-5.0 milliequivalents per gram of said polyelectrolyte, depending on said polyelectrolyte, sufficient to render said polyelectrolyte both water-insoluble and water-swellable;
• said composition further being defined as providing a gelatinous agglomerate of liquid-swollen particulate members in the presence of a quantity of body exudate, as having a film swell index in synthetic urine of at least 15, as being capable of absorbing at least fifteen times its weight in body exudate, as capable of retaining said absorbed exudate when exposed to pressure sufficient to deform said agglomerate, and as capable of uncomplexing at an elevated pH to form said water-soluble anionic polyelectrolyte and recomplexing at a lower pH.

A dry, solid, water-swellable, water-insoluble absorbent composition of matter consisting essentially of an ionic complex of

• (a) an anionic polyelectrolyte which is a water-soluble synthetic polymer in the absence of the cation of (b);
• and
• (b) a polyvalent metal cation having a valence of at least 3, said cation being present in an amount within the range of 0.1-5.0 milliequivalents per gram of said polyelectrolyte, depending on said polyelectrolyte, sufficient to render said polyelectrolyte both water-insoluble and water-swellable;
• said composition further being defined as providing a gelatinous agglomerate of liquid-swollen particulate members in the presence of a quantity of body exudate, as having a film swell index in synthetic urine of at least 15, as being capable of absorbing at least 15 times its weight in body exudate, as capable of retaining said absorbed exudate when exposed to pressure sufficient to deform said agglomerate, and as capable of uncomplexing at an elevated pH to form said water-soluble anionic polyelectrolyte and recomplexing at a lower pH.