Absorbent composition of matter

Claim 2

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 0.1-1.0 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.

Claim 3

The composition of claim 1 wherein said cation is aluminum.

Claim 4

The composition of claim 1 wherein said polyelectrolyte has 40-85% of its carboxylate groups neutralized by an alkali metal hydroxide or a primary, secondary or tertiary amine or a mixture thereof.

Claim 5

The composition of claim 1 wherein said polyelectrolyte is polyacrylic acid having 40-85% of its carboxylate groups neutralized.

Claim 6

The composition of claim 4 wherein said polyelectrolyte has 40-85% of its anionic groups neutralized by an alkali metal hydroxide or a primary, secondary or tertiary amine or a mixture thereof.

Claim 7

The composition of claim 1 wherein said polyelectrolyte contains anionic groups selected from the group consisting of carboxylate, sulfonate, sulfate and phosphate groups, and mixtures thereof.

Claim 8

The composition of claim 1 wherein said cation is selected from the group consisting of aluminum, iron, chromium, zirconium, titanium and mixtures thereof.

Claim 9

The composition of claim 1 wherein said polyelectrolyte is an anionic starch or cellulose.

Claim 10

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.

Claim 11

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.

Claim 12

The composition of claim 9 wherein said polyelectrolyte is polyacrylic acid having 40-85% of its carboxylate groups neutralized.

Claim 13

The composition of claim 10 wherein said polyelectrolyte has 40-85% of its carboxylate groups neutralized by an alkali metal hydroxide or a primary, secondary or tertiary amine or a mixture thereof.

Claim 14

The composition of claim 9 wherein said polyelectrolyte has 40-85% of its anionic groups neutralized by an alkali metal hydroxide or a primary, secondary or tertiary amine or a mixture thereof.

Claim 15

The composition of claim 9 wherein said cation is present in an amount not in excess of 1.0 milliequivalents per gram of polyelectrolyte.

Claim 16

The composition of claim 9 wherein said cation is aluminum.

Claim 17

The composition of claim 9 wherein said polyelectrolyte contains anionic groups selected from the group consisting of carboxylate, sulfonate, sulfate and phosphate groups, and mixtures thereof.

Claim 18

The composition of claim 9 wherein said cation is selected from the group consisting of aluminum, iron, chromium, zirconium, titanium and mixtures thereof.

Claim 19

The composition of claim 9 wherein said polyelectrolyte is an anionic starch or cellulose.

Claim 20

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.

Claim 21

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.

Claim 22

The composition of claim 18 wherein said polyelectrolyte contains anionic groups selected from the group consisting of carboxylate, sulfonate, sulfate and phosphate groups, and mixtures thereof.

Claim 23

The composition of claim 18 wherein said cation is selected from the group consisting of aluminum, iron, chromium, zirconium, titanium and mixtures thereof.

Claim 24

The composition of claim 18 wherein said polyelectrolyte is an anionic starch or cellulose.

Claim 25

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.

Claim 26

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.

Claim 27

The composition of claim 22 wherein said polyelectrolyte is polyacrylic acid having 40-85% of its carboxylate groups neutralized.

Claim 28

The composition of claim 23 wherein said polyelectrolyte has 40-85% of its carboxylate groups neutralized by an alkali metal hydroxide or a primary, secondary or tertiary amine or a mixture thereof.

Claim 29

The composition of claim 23 wherein said cation is present in an amount not in excess of 1.0 milliequivalents per gram of polyelectrolyte.

Claim 30

The composition of claim 23 wherein said cation is present in the amount of 0.1-1.0 milliequivalents per gram of polyelectrolyte.

Claim 31

The composition of claim 22 wherein said polyelectrolyte has 40-85% of its anionic groups neutralized by an alkali metal hydroxide or a primary, secondary or tertiary amine or a mixture thereof.

Claim 32

The composition of claim 22 wherein said cation is present in an amount not in excess of 1.0 milliequivalents per gram of polyelectrolyte.

Claim 33

The composition of claim 22 wherein said cation is present in the amount of 0.1-1.0 milliequivalents per gram of polyelectrolyte.

Claim 34

The composition of claim 22 wherein said polyelectrolyte contains anionic groups selected from the group consisting of carboxylate, sulfonate, sulfate and phosphate groups, and mixtures thereof.

Claim 35

The composition of claim 22 wherein said polyeletrolyte is an anionic starch or cellulose.

Claim 36

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.

Claim 37

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.

Claim 38

The composition of claim 32 wherein said cation is aluminum.

Claim 39

The composition of claim 32 wherein said synthetic polymer is polyacrylic acid.

Claim 40

The composition of claim 34 wherein said polyacrylic acid polymer has 40-85% of its carboxylate groups neutralized by an alkali metal hydroxide or a primary, secondary or tertiary amine or a mixture thereof.

Claim 41

The composition of claim 32 wherein said cation is selected from the group consisting of aluminum, iron, chromium, zirconium, titanium and mixtures thereof.

Claim 42

The composition of claim 32 wherein said synthetic polymer has 40-85% of its anionic groups neutralized.

Claim 43

The composition of claim 32 wherein said synthetic polymer has 40-85% of its anionic groups neutralized by an alkali metal hydroxide or a primary, secondary or tertiary amine or a mixture thereof.

Claim 44

The composition of claim 32 wherein said cation is present in an amount not in excess of 1.0 milliequivalents per gram of polyelectrolyte.

Claim 45

The composition of claim 32 wherein said synthetic polymer is a carboxylic acid homopolymer or copolymer containing at least 20 mole percent carboxylic acid units.

Claim 46

The composition of claim 32 wherein said synthetic polymer contains anionic groups selected from the group consisting of carboxylate, sulfonate, sulfate and phosphate groups, and mixtures thereof.

Claim 47

The composition of claim 41 wherein said synthetic polymer has up to 95% of its anionic groups neutralized.