Superabsorbent polymer with high permeability
View Patent ↗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.
1. 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 cm 2 where x is the numeric value of centrifuge retention capacity; and a shear modulus G′ is less than about 9,500 dynes/cm 2 and an absorption against pressure at 0.7 psi of less than about 23 g/g.
2. A superabsorbent polymer composition according to claim 1 wherein GBP is at least about [54000 e −0.175x +100]×10 −9 cm 2 .
3. A superabsorbent polymer according to claim 1 wherein GBP is at least about [54000 e −0.17x +100]×10 −9 cm 2 .
4. A superabsorbent polymer composition according to claim 1 wherein GBP is at least about [54000 e −0.165x +100]×10 −9 cm 2 .
5. A superabsorbent polymer composition according to claim 1 wherein the centrifuge retention capacity is greater than about 25 g/g.
6. A superabsorbent polymer compostion according to claim 1 wherein the centrifuge retention capacity is greater than about 27 g/g.
7. A superabsorbent polymer composition according to claim 1 wherein the gel bed permeability is at least about 500×10 −9 cm 2 .
8. A superabsorbent polymer composition according to claim 1 wherein the shear modulus is from about 4000 to about 9000 dynes/cm 2 .
9. A superabsorbent polymer composition according to claim 1 having the characteristics of centrifuge retention capacity from about 27 to about 30 g/g; a shear modulus from about 6400 to 8000 dynes/cm 2 , and a gel bed permeability from about 800×10 −9 cm 2 to about 1500×10 −9 cm 2 .
10. A superabsorbent polymer composition according to claim 1 having the characteristics of centrifuge retention capacity of at least about 30 g/g; a shear modulus from about 4500 to 6400 dynes/cm 2 , and a gel bed permeability of at least about 600×10 −9 cm 2 .
11. 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 cm 2 where x is the numeric value of the centrifuge retention capacity; and a shear modulus, G′, is less than about 9,500 dynes/cm 2 and an absorption against pressure at 0.7 psi of less than about 23 g/g.
12. A superabsorbent polymer composition according to claim 11 wherein GBP is at least about [54000 e −0.175x +100]×10 −9 cm 2 .
13. A superabsorbent polymer composition according to claim 11 wherein GBP is at least about [54000 e −0.17x +100]×10 −9 cm 2 .
14. A superabsorbent polymer composition according to claim 11 wherein GBP is at least about [54000 e −0.165x +100]×10 −9 cm 2 .
15. A superabsorbent polymer composition according to claim 11 wherein the gel bed permeability is at least about 500×10 −9 cm 2 .
16. A superabsorbent polymer composition according to claim 11 having the characteristics of centrifuge retention capacity from about 27 to about 30 g/g; a shear modulus from about 6400 to 8000 dynes/cm 2 , and a gel bed permeability from about 800×10 −9 cm 2 to about 1500×10 −9 cm 2 .
17. A superabsorbent polymer composition according to claim 11 having the characteristics of centrifuge retention capacity of at least about 30 g/g; a shear modulus from about 4500 to 6400 dynes/cm 2 , and a gel bed permeability of at least about 600×10 −9 cm 2 .
18. 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/cm 2 and a gel bed permeability from about 800×10 −9 cm 2 to about 1500×10 −9 cm 2 and an absorption against pressure at 0.7 psi of less than about 23 g/g.
19. 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 cm 2 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.
20. A superabsorbent polymer composition according to claim 19 wherein GBP is at least about [54000 e −0.175x +100]×10 −9 cm 2 .
21. A superabsorbent polymer composition according to claim 19 wherein GBP is at least about [54000 e −0.17x +100]×10 −9 cm 2 .
22. A superabsorbent polymer composition according to claim 19 wherein GBP is at least about [54000 e −0.165x +100]×10 −9 cm 2 .
23. A superabsorbent polymer composition according to claim 19 wherein the centrifuge retention capacity is greater than about 25 g/g.
24. A superabsorbent polymer composition according to claim 19 wherein the centrifuge retention capacity is greater than about 27 g/g.
25. A superabsorbent polymer composition according to claim 19 having the characteristics of centrifuge retention capacity from about 27 to about 30 g/g; and a gel bed permeability from about 800×10 −9 cm 2 to about 1500×10 −9 cm 2 .
26. A superabsorbent polymer composition according to claim 19 having the characteristics of centrifuge retention capacity of at least about 30 g/g; and a gel bed permeability of at least about 600×10 −9 cm 2 .
27. 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 cm 2 to about 1500×10 −9 cm 2 and an absorption against pressure at 0.7 psi of less than about 23 g/g.
28. 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 cm 2 and greater than [0.34(G′)−2080]×10 −9 cm 2 where G′ is the numeric value of shear modulus in dynes/cm 2 ; and an absorption against pressure at 0.7 psi of less than about 23 g/g.
29. A superabsorbent polymer according to claim 28 where the GBP is at least 400×10 −9 cm 2 .
30. A superabsorbent polymer composition according to claim 28 where the GBP is at least 500×10 −9 cm 2 .
31. A superabsorbent polymer composition according to claim 28 having the characteristics of centrifuge retention capacity from about 27 to about 30 g/g; a shear modulus from about 6400 to 8000 dynes/cm 2 .
32. A superabsorbent polymer composition according to claim 28 having the characteristics of centrifuge retention capacity of at least about 30 g/g; a shear modulus from about 4500 to 6400 dynes/cm 2 .
33. 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 cm 2 where G′ is the numeric value of the shear modulus; with a minimum GBP of 300×10 −9 cm 2 and an absorption against pressure at 0.7 psi of less than about 23 g/g.
34. A superabsorbent polymer composition according to claim 33 where the GBP is at least 400×10 −9 cm 2 .
35. A superabsorbent polymer composition according to claim 33 where the GBP is at least 500×10 −9 cm 2 .
36. A superabsorbent polymer composition according to claim 33 having the characteristics of centrifuge retention capacity from about 27 to about 30 g/g; a shear modulus from about 6400 to 8000 dynes/cm 2 .
37. A superabsorbent polymer composition according to claim 33 having the characteristics of centrifuge retention capacity of at least about 30 g/g; a shear modulus from about 4500 to 6400 dynes/cm 2 .
38. 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 cm 2 where x is the numeric value of centrifuge retention capacity; and a shear modulus G′ is less than about 9,500 dynes/cm 2 .
39. A superabsorbent polymer composition according to claim 38 wherein GBP is at least about [54000 e −0.175x +100]×10 −9 cm 2 .
40. A superabsorbent polymer composition according to claim 38 wherein GBP is at least about [54000 e −0.17x +100]×10 −9 cm 2 .
41. A superabsorbent polymer compositon according to claim 38 wherein GBP is at least about [54000 e −0.165x +100]×10 −9 cm 2 .
42. A superabsorbent polymer composition according to claim 38 wherein the centrifuge retention capacity is greater than about 25 g/g.
43. A superabsorbent polymer compositon according to claim 38 wherein the centrifuge retention capacity is greater than about 27 g/g.
44. A superabsorbent polymer composition according to claim 38 wherein the gel bed permeability is at least about 500×10 −9 cm 2 .
45. A superabsorbent polymer composition according to claim 38 wherein the shear modulus is from about 4000 to about 9000 dynes/cm 2 .
46. A superabsorbent polymer composition according to claim 38 having the characteristics of centrifuge retention capacity from about 27 to about 30 g/g; a shear modulus from about 6400 to 8000 dynes/cm 2 , and a gel bed permeability from about 800×10 −9 cm 2 to about 1500×10 −9 cm 2 .
47. A superabsorbent polymer composition according to claim 38 having the characteristics of centrifuge retention capacity of at least about 30 g/g; a shear modulus from about 4500 to 6400 dynes/cm 2 , and a gel bed permeability of at least about 600×10 −9 cm 2 .
48. 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 cm 2 where x is the numeric value of the centrifuge retention capacity; and a shear modulus, G′, is less than about 9,500 dynes/cm 2 .
49. A superabsorbent polymer composition according to claim 48 wherein GBP is at least about [54000 e −0.175x +100]×10 −9 cm 2 .
50. A superabsorbent polymer composition according to claim 48 wherein GBP is at least about [54000 e −0.17x +100]×10 −9 cm 2 .
51. A superabsorbent polymer composition according to claim 48 wherein GBP is at least about [54000 e −0.165x +100]×10 −9 cm 2 .
52. A superabsorbent polymer composition according to claim 48 wherein the gel bed permeability is at least about 500×10 −9 cm 2 .
53. A superabsorbent polymer composition according to claim 48 having the characteristics of centrifuge retention capacity from about 27 to about 30 g/g; a shear modulus from about 6400 to 8000 dynes/cm 2 , and a gel bed permeability from about 800×10 −9 cm 2 to about 1500×10 −9 cm 2 .
54. A superabsorbent polymer composition according to claim 48 having the characteristics of centrifuge retention capacity of at least about 30 g/g; a shear modulus from about 4500 to 6400 dynes/cm 2 , and a gel bed permeability of at least about 600×10 −9 cm 2 .
55. 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/cm 2 and a gel bed permeability from about 800×10 −9 cm 2 to about 1500×10 −9 cm 2 .
56. 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 cm 2 and greater than [0.34(G′)−2080]×10 −9 cm 2 where G′ is the numeric value of shear modulus in dynes/cm 2 .
57. A superabsorbent polymer composition according to claim 56 where the GBP is at least 400×10 −9 cm 2 .
58. A superabsorbent polymer composition according to claim 56 where the GBP is at least 500×10 −9 cm 2 .
59. A superabsorbent polymer composition according to claim 56 having the characteristics of centrifuge retention capacity from about 27 to about 30 g/g; a shear modulus from about 6400 to 8000 dynes/cm 2 .
60. A superabsorbent polymer composition according to claim 56 having the characteristics of centrifuge retention capacity of at least about 30 g/g; a shear modulus from about 4500 to 6400 dynes/cm 2 .
61. 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 cm 2 where G′ is the numeric value of the shear modulus; with a minimum GBP of 300×10 −9 cm 2 .
62. A superabsorbent polymer composition according to claim 61 where the GBP is at least 400×10 −9 cm 2 .
63. A superabsorbent polymer composition according to claim 61 where the GBP is at least 500×10 −9 cm 2 .
64. A superabsorbent polymer composition according to claim 61 having the characteristics of centrifuge retention capacity from about 27 to about 30 g/g; a shear modulus from about 6400 to 8000 dynes/cm 2 .
65. A superabsorbent polymer composition according to claim 61 having the characteristics of centrifuge retention capacity of at least about 30 g/g; a shear modulus from about 4500 to 6400 dynes/cm 2 .
66. A superabsorbent polymer composition according to claim 1 comprising from about 0.01 % to about 5 wt. % of a multivalent metal salt.
67. A superabsorbent polymer composition according to claim 66 wherein the multivalent salt is aluminum sulfate.
68. A superabsorbent polymer composition according to claim 11 comprising for about 0.01 % to about 5 wt. % of a pretration modifier.
69. A superabsorbent polymer composition according to claim 11 comprising from about 0.01 % to about 5 wt. % of a multivalent metal salt.
70. A superabsorbent polymer composition according to claim 69 wherein the multivalent said is aluminum sulfate.
71. A superabsorbent polymer composition according to claim 18 comprising from about 0.01 % to about 5 wt. % of a multivalent metal salt.
72. A superabsorbent polymer composition according to claim 71 wherein the multivalent salt is aluminum sulfate.
73. A superabsorbent polymer composition according to claim 27 comprising from about 0.01 % to about 5 wt. % of a multivalent metal salt.
74. A superabsorbent polymer composition according 73 wherein the multivalent salt is aluminum sulfate.