Superabsorbent polymer with high permeability
AssigneeStockhausen GmbH & Co. KG
InventorsScott J. Smith, Mark C. Joy, Whei-Neen Hsu, Markus Frank
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Abstract
The invention relates to absorptive, crosslinked polymers which are based on partly neutralized, monoethylenically unsaturated monomers carrying acid groups, and have improved properties, in particular in respect of their capacity for transportation of liquids in the swollen state, and which has a high gel bed permeability and high centrifuge retention capacity.
Claims74
A superabsorbent polymer composition comprising a polymer consisting essentially of:
- a) from about 55 to about 99.9 wt. % of polymerizable unsaturated acid group containing monomers;
- b) from about 0.001 to about 5.0 wt. % based on the weight of a) of internal crosslinking agent;
- said superabsorbent polymer composition further comprising
- c) from about 0.001 to about 5.0 wt. % based on dry polymer powder weight of surface crosslinking agent applied to the particle surface;
- d) from about 0.01% to about 5 wt. % based on dry polymer powder weight of a penetration modifier added immediately before, during or immediately after the surface crosslinking step;
- e) from 0 to about 5 wt. % based on dry polymer powder weight of a multivalent metal salt on the surface;
- f) from 0 to 2 wt % based on dry polymer powder weight of a surfactant on the surface;
- and
- g) from about 0.01 to about 5 wt % based on dry polymer powder weight of an insoluble, inorganic powder wherein the composition has a degree of neutralization of more than about 25%;
- and a gel bed permeability numeric value GBP is at least about [54000 e−0.18x+75]×10−9 cm2 where x is the numeric value of centrifuge retention capacity;
- and a shear modulus G′ is less than about 9,500 dynes/cm2 and an absorption against pressure at 0.7 psi of less than about 23 g/g.
A water insoluble, slightly cross-linked, partially neutralized, superabsorbent polymer composition comprising a polymer consisting essentially of a polymerizable unsaturated acid group containing monomers and an internal crosslinking agent, and the superabsorbent polymer further comprising a penetration modifier, wherein the superabsorbent polymer has a gel bed permeability numeric value, GBP, of at least about [54000 e−0.18x+75]×10−9 cm2 where x is the numeric value of the centrifuge retention capacity;
- and a shear modulus, G′, is less than about 9,500 dynes/cm2 and an absorption against pressure at 0.7 psi of less than about 23 g/g.
A superabsorbent polymer composition comprising a polymer consisting essentially of:
- a) from about 55 to about 99.9 wt. % of polymerizable unsaturated acid group containing monomers;
- and
- b) from about 0.001 to about 5.0 wt. % based on the weight of a) of internal crosslinking agent;
- said superabsorbent polymer composition further comprising
- c) from about 0.001 to about 5.0 wt. % based on dry polymer powder weight of surface crosslinking agent applied to the particle surface;
- d) from about 0.01% to about 5 wt. % based on dry polymer powder weight of a penetration modifier added immediately before, during or immediately after the surface crosslinking step;
- e) from 0 to about 5 wt. % based on dry polymer powder weight of a multivalent metal salt on the surface;
- f) from 0 to 2 wt % based on dry polymer powder weight of a surfactant on the surface;
- and
- g) from about 0.01 to about 5 wt % based on dry polymer powder weight of an insoluble, inorganic powder wherein the composition has a degree of neutralization of more than about 25%;
- having the characteristics of centrifuge retention capacity from about 27 to about 30 g/g;
- a shear modulus from about 6400 to about 8000 dynes/cm2 and a gel bed permeability from about 800×10−9 cm2 to about 1500×10−9 cm2 and an absorption against pressure at 0.7 psi of less than about 23 g/g.
A superabsorbent polymer composition comprising a polymer consisting essestially of:
- a) from about 55 to about 99.9 wt. % of polymerizable unsaturated acid group containing monomers;
- b) from about 0.001 to about 5.0 wt. % based on the weight of a) of internal crosslinking agent;
- said superabsorbent polymer composition further comprising
- c) from about 0.001 to about 5.0 wt. % based on dry polymer powder weight of surface crosslinking agent applied to the particle surface;
- d) from about 0.01% to about 5 wt. % based on dry powder weight of a penetration modifier added immediately before, during or immediately after the surface crosslinking step;
- e) from 0 to about 5 wt. % based on dry polymer powder weight of a multivalent metal salt on the surface;
- f) from 0 to 2 wt % based on dry polymer powder weight of a surfactant on the surface;
- and
- g) from about 0.01 to about 5 wt % based on dry polymer powder of an insoluble, inorganic powder wherein the composition has, a degree of neutralization of more than about 25%;
- and a gel bed permeability numeric value GBP is at least about [54000 e−0.18x+75]×10−9 cm2 where x is the numeric value of centrifuge retention capacity;
- and an absorption against pressure at 0.7 psi of less than about 23 g/g.
A superabsorbent polymer composition comprising a polymer consisting essentially of:
- a) from about 55 to about 99.9 wt. % of polymerizable unsaturated acid group containing monomers;
- b) from about 0.001 to about 5.0 wt. % based on the weight of a) of internal crosslinking agent;
- said superabsorbent polymer composition further comprising
- c) from about 0.001 to about 5.0 wt. % based on dry polymer powder weight of surface crosslinking agent applied to the particle surface;
- d) from about 0.01% to about 5 wt. % based on dry poymer powder weight of a penetration modifier added immediately before, during or immediately after the surface crosslinking step;
- e) from 0 to about 5 wt. % based on dry polymer powder weight of a multivalent metal salt on the surface;
- f) from 0 to 2 wt % based on dry polymer powder weight of the surfactant on the surface;
- and
- g) from about 0.01 to about 5 wt % based on dry polymer powder weight of an insoluble, inorganic powder wherein the composition has, a degree of neutralization of more than about 25%;
- having the characteristics of centrifuge retention capacity from about 27 to about 30 g/g;
- a gel bed permeability from about 800×10−9 cm2 to about 1500×10−9 cm2 and an absorption against pressure at 0.7 psi of less than about 23 g/g.
A superabsorbent polymer composition comprising a polymer consisting essentially of:
- a) from about 55 to about 99.9 wt. % of polymerizable unsaturated acid group containing monomers;
- b) from about 0.001 to about 5.0 wt. % based on the weight of a) of internal crosslinking agent;
- said superabsorbent polymer composition further comprising
- c) from about 0.001 to about 5.0 wt. % based on dry polymer powder weight of surface crosslinking agent applied to the particle surface;
- d) from about 0.01% to about 5 wt. % based on dry polymer powder weight of a penetration modifier added immediately before, during or immediately after the surface crosslinking step;
- e) from 0 to about 5 wt. % based on dry polymer powder weight of a multivalent metal salt on the surface;
- f) from 0 to 2 wt % based on dry polymer powder weight of a surfactant on the surface;
- and
- g) from about 0.01 to about 5 wt % based on dry polymer weight of an insoluble, inorganic powder wherein the composition has, a degree of neutralization of more than about 25%;
- and a gel bed permeability is at least 300×10−9 cm2 and greater than [0.34(G′)−2080]×10−9 cm2 where G′ is the numeric value of shear modulus in dynes/cm2;
- and an absorption against pressure at 0.7 psi of less than about 23 g/g.
A water insoluble, slightly cross-linked, partially neutralized, superabsorbent polymer composition comprising a polymer consisting essentially of a polymerizable unsaturated acid group containing monomers and an internal crosslinking agent, and the superabsorbent polymer further comprising a penetration modifier, wherein the superabsorbent polymer has a gel bed permeability numeric value, GBP, at least about [0.34(G′−(2080)]×10−9 cm2 where G′ is the numeric value of the shear modulus;
- with a minimum GBP of 300×10−9 cm2 and an absorption against pressure at 0.7 psi of less than about 23 g/g.
A superabsorbent polymer composition comprising a polymer consisting essentially of:
- a) from about 55 to about 99.9 wt. % of polymerizable unsaturated acid group containing monomers;
- b) from about 0.001 to about 5.0 wt. % based on the weight of a) of internal crosslinking agent;
- said superabsorbent polymer composition further comprising
- c) from about 0.001 to about 5.0 wt. % based on dry polymer powder weight of surface crosslinking agent applied to the particle surface;
- d) from about 0.01% to about 5 wt. % based on dry polymer powder weight of a penetration modifier added immediately before, during or immediately after the surface crosslinking step;
- e) from 0 to about 5 wt. % based on dry polymer powder weight of a multivalent metal salt on the surface;
- f) from 0 to 2 wt % based on dry polymer powder weight of a surfactant on the surface;
- and
- g) from about 0.01 to about 5 wt % based on dry polymer powder weight of an insoluble, inorganic powder wherein the composition has a degree of neutralization of more than about 25%;
- and a gel bed permeability numeric value GBP is at least about [54000 e−0.18x+75]×10−9 cm2 where x is the numeric value of centrifuge retention capacity;
- and a shear modulus G′ is less than about 9,500 dynes/cm2.
A water insoluble, slightly cross-linked, partially neutralized, superabsorbent polymer composition comprising a polymer consisting essentially of a polymerizable unsaturated acid group containing monomers and an internal crosslinking agent, and the superabsorbent polymer further comprising a penetration modifier, wherein the superabsorbent polymer has a gel bed permeability numeric value, GBP, of at least about [54000 e−0.18x+75]×10−9 cm2 where x is the numeric value of the centrifuge retention capacity;
- and a shear modulus, G′, is less than about 9,500 dynes/cm2.
A superabsorbent polymer composition comprising a polymer consisting essentially of:
- a) from about 55 to about 99.9 wt. % of polymerizable unsaturated acid group containing monomers;
- b) from about 0.001 to about 5.0 wt. % based on the weight of a) of internal crosslinking agent;
- said superabsorbent polymer composition further comprising
- c) from about 0.001 to about 5.0 wt. % based on dry polymer powder weight of surface crosslinking agent applied to the particle surface;
- d) from about 0.01% to about 5 wt. % based on dry polymer powder weight of a penetration modifier added immediately before, during or immediately after the surface crosslinking step;
- e) from 0 to about 5 wt. % based on dry polymer powder weight of a multivalent metal salt on the surface;
- f) from 0 to 2 wt % based on dry polymer powder weight of a surfactant on the surface;
- and
- g) from about 0.01 to about 5 wt % based on dry polymer powder of an insoluble, inorganic powder wherein the composition has a degree of neutralization of more than about 25%;
- having the characteristics of centrifuge retention capacity from about 27 to about 30 g/g;
- a shear modulus from about 6400 to about 8000 dynes/cm2 and a gel bed permeability from about 800×10−9 cm2 to about 1500×10−9 cm2.
A superabsorbent polymer composition comprising a polymer consisting essentially of:
- a) from about 55 to about 99.9 wt. % of polymerizable unsaturated acid group containing monomers;
- b) from about 0.001 to about 5.0 wt. % based on the weight of a) of internal crosslinking agent;
- said superabsorbent polymer composition further comprising
- c) from about 0.001 to about 5.0 wt. % based on dry polymer powder weight of surface crosslinking agent applied to the particle surface;
- d) from about 0.01% to about 5 wt. % based on dry polymer powder of a penetration modifier added immediately before, during or immediately after the surface crosslinking step;
- e) from 0 to about 5 wt. % based on dry polymer powder weight of a multivalent metal salt on the surface;
- f) from 0 to 2 wt % based on dry polymer powder weight of a surfactant on the surface;
- and
- g) from about 0.01 to about 5 wt % based on dry polymer powder weight of an insoluble, inorganic powder wherein the composition has a degree of neutralization of more than about 25%;
- and a gel bed permeability is at least 300×10−9 cm2 and greater than [0.34(G′)−2080]×10−9 cm2 where G′ is the numeric value of shear modulus in dynes/cm2.
A water insoluble, slightly cross-linked, partially neutralized, superabsorbent polymer composition comprising a polymer consisting essentially of a polymerizable unsaturated acid group containing monomers and an internal crosslinking agent, and the superabsorbent polymer further comprising a penetration modifier, wherein the superabsorbent polymer has a gel bed permeability numeric value, GBP, at least about [0.34(G′−(2080)]×10−9 cm2 where G′ is the numeric value of the shear modulus;
- with a minimum GBP of 300×10−9 cm2.
A superabsorbent polymer composition according 73 wherein the multivalent salt is aluminum sulfate.
Dependencies are inferred from the claim text.