Source: https://patents.justia.com/patent/20070167560
Timestamp: 2020-04-04 12:38:08
Document Index: 539767240

Matched Legal Cases: ['arth 4', 'arth 4', 'arth 4', 'arth 4', 'arth 4', 'arth 4']

US Patent Application for SUPERABSORBENT POLYMER WITH HIGH PERMEABILITY Patent Application (Application #20070167560 issued July 19, 2007) - Justia Patents Search
Justia Patents US Patent Application for SUPERABSORBENT POLYMER WITH HIGH PERMEABILITY Patent Application (Application #20070167560)
In one embodiment of the present invention, the superabsorbent polymer is a crosslinked polymer wherein the superabsorbent polymer has a gel bed permeability (GBP) numeric value of at least about [54000e−0.18x+75]×10−9 cm2 where x is the numeric value of centrifuge retention capacity (CRC); and a shear modulus (G′) of less than about 9,500 dynes/cm2 . Preferably, such superabsorbent polymers exhibit a centrifuge retention capacity from about 25 to 35 g/g, a shear modulus from 5000 to 8500 dynes/cm2, and a gel bed permeability from about 500 to 2500×10−9 cm2, and an absorption against pressure of less than 23 g/g. One preferred embodiment is a such superabsorbent polymer having a 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 to about 1500×10−9 cm2 and an absorption against pressure of less than about 23 g/g. Other embodiments include, but not limited to, include a superabsorbent polymer according to the present invention wherein GBP is at least about [54000e−0.175+100]×10−9 cm2; or the GBP is at least about [54000e−0.17x+100]×10−9 cm2; or wherein GBP is at least about [54000e−0.165x+100]×10−9 cm2; or wherein the gel bed permeability is at least about 500×10−9 cm2; or the superabsorbent polymer having centrifuge retention capacity from about 27 to about 30 g/g; a shear modulus from about 6400 to 8000 dynes/cm2, and a gel bed permeability from about 800×10−9 cm2 to about 1500×10×9 cm2 ; or a superabsorbent polymer according to the present invention having the characteristics of centrifuge retention capacity of at least about 30 g/g; a shear modulus from about 4500 to 6400 dynes/cm2, and a gel bed permeability of at least about 600×10−9 cm2.
In one embodiment of the present invention, the superabsorbent polymer is a crosslinked polymer comprising 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. % of internal crosslinking agent; c) from about 0.001 to about 5.0 wt. % of surface crosslinking agent applied to the particle surface; d) from 0 to about 5 wt. % of a penetration modifier applied to the surface of the particle immediately before, during or immediately after the surface crosslinking step; e) from 0 to about 5 wt. % of a multivalent metal salt on the surface; and f) from about 0.01 to about 5 wt % of an insoluble, inorganic powder, and g) from about 0 to about 2% surface active agent on the surface, wherein the superabsorbent polymer has a degree of neutralization of more than about 25%; a gel bed permeability (GBP) numeric value of at least about [54000e−0.18x+75]×10−9 cm2 where x is the numeric value of centrifuge retention capacity (CRC); a shear modulus (G′) of less than about 9,500 dynes/cm2 and an absorption against pressure (AAP) of less than about 23 g/g. Preferably, such superabsorbent polymers exhibit a centrifuge retention capacity from about 25 to 35 g/g, a shear modulus from 5000 to 8500 dynes/cm2, and a gel bed permeability from about 500 to 2500×10−9 cm2, and an absorption against pressure of less than 23 g/g. One preferred embodiment is a such superabsorbent polymer having a centrifuge retention capacity from about 27 to about 30 g/g; a shear modulus from about 6400 to about 8,000 dynes/cm2; and a gel bed permeability from about 800 to about 1500×10−9 cm2 and an absorption against pressure of less than about 23 g/g.
As used herein, the Gel Bed Permeability (GBP) Test determines the permeability of a swollen bed of superabsorbent polymer under what is commonly referred to as “free swell” conditions. The term “free swell” means that the superabsorbent polymer is allowed to swell without a swell restraining load upon absorbing test solution as will be described. A suitable apparatus for conducting a Permeability Test is shown in FIG. 1 and 2 and indicated generally as 28. The test apparatus 28 comprises a sample container, generally indicated at 30, and a piston, generally indicated at 36. The piston 36 comprises a cylindrical LEXAN® shaft 38 having a concentric cylindrical hole 40 bored down the longitudinal axis of the shaft. Both ends of the shaft 38 are machined to provide upper and lower ends respectively designated 42, 46. A weight, indicated as 48, rests on one end 42 and has a cylindrical hole 48a bored through at least a portion of its center.
A circular piston head 50 is positioned on the other end 46 and is provided with a concentric inner ring of seven holes 60, each having a diameter of about 0.95 cm, and a concentric outer ring of fourteen holes 54, also each having a diameter of about 0.95 cm.
The holes 54, 60 are bored from the top to the bottom of the piston head 50. The piston head 50 also has a cylindrical hole 62 bored in the center thereof to receive end 46 of the shaft 38. The bottom of the piston head 50 may also be covered with a biaxially stretched 400 mesh stainless steel screen 64.
sample/bag after centrifuge−empty bag after centrifuge−dry sample weight dry sample weight
The superabsorbent polymer also suitably has a gel bed permeability (GBP) as determined by the Gel Bed Permeability Test described previously of at least [54000e−0.18x+75]×10−9 cm2, where x is the numeric value of centrifuge retention capacity; preferably GBP is at least about [54000e −0.175x+100]×10−9 cm2 and more preferably GBP is at least about [54000e−0.17x+100]×10−9 cm2 and most preferably GBP is at least about [54000e−0.165x+100]×10−9 cm2.
wherein G is the shear modulus in Nm−2; ρ is the density of the superabsorbent polymer sample in kg.m−3 and V is the wave propagation velocity in ms−1.
G′=[V2ρ(1−n2)]/(1+n2)2
In an insulated, flat-bottomed reaction vessel, 800 g of acrylic acid was added to 3090.26 g of distilled water and the solution cooled to 25° C. A second solution of 1600 g of acrylic acid containing 4.8 g of triallyamine, 120.53 g 50 wt % methoxypolyethyleneglycol(750)monomethacrylate in acrylic acid and 3.6 g of trimethylolpropanetriacrylate with 9 moles of ethoxylation were then added to the first solution, followed by cooling to 15° C., the addition of 24.0 g of allyl ether acrylate with 10 moles of ethoxylation, and additional cooling to 5° C., all while stirring. The monomer solution was then polymerized with a mixture of 150 ppm hydrogen peroxide, 200 ppm azo-bis-(2-amidino-propene)dihydrochloride, 350 ppm sodiumpersulfate and 100 ppm sodium erythorbate under adiabatic conditions and held near Tmax for 25 minutes. The resulting gel was chopped and extruded with a Hobarth 4M6 commercial extruder, followed by drying in a Procter & Schwartz Model 062 forced air oven at 175° C. for 10 minutes with upflow and 6 minutes with downflow air on a 20 in×40 in perforated metal tray to a final product moisture level of less than 5 wt %. The dried material was coarse ground in a Prodeva Model 315-S crusher, milled in an MPI 666-F three stage roller mill and sieved with an Minox MTS 600DS3V to remove particles greater than 850 microns and smaller than 150 microns. 400 g of the sieved powder was then blended uniformly with 0.5 wt % Aerosil 200 fumed silica and 0.2 wt % aluminium sulfate, followed by the uniform spray application of a solution 0.1 wt % disodium cocoamphopropionate, 0.5 wt % tetraethyleneglycol dimethyether, and 1.0 wt % ethylene carbonate in 4 g of water, using a finely atomized spray from a Paasche VL sprayer while the SAP particles are fluidized in air and continuously mixed. All wt % values based on the weight of dry SAP powder.
The coated material was then heated for 20 minutes at 180° C. in a General Signal/BM Model OV-510A-3 forced air oven.
In an insulated, flat-bottomed reaction vessel, 800 g of acrylic acid was added to 3090.26 g of distilled water and the solution cooled to 25° C. A second solution of 1600 g of acrylic acid containing 9.6 g of triallyamine, 120.53 g 50wt % methoxypolyethyleneglycol(750)monomethacrylate in acrylic acid and 7.2 g of trimethylolpropanetriacrylate with 9 moles of ethoxylation were then added to the first solution, followed by cooling to 15° C., the addition of 24.0 g of allyl ether acrylate with 10 moles of ethoxylation, and additional cooling to 5° C., all while stirring. The monomer solution was then polymerized with a mixture of 150 ppm hydrogen peroxide, 200 ppm azo-bis-(2-amidino-propene)dihydrochloride, 350 ppm sodiumpersulfate and 100 ppm sodium erythorbate under adiabatic conditions and held near Tmax for 25 minutes. The resulting gel was chopped and extruded with a Hobarth 4M6 commercial extruder, followed by drying in a Procter & Schwartz Model 062 forced air oven at 175° C. for 10 minutes with upflow and 6 minutes with downflow air on a 20 in×40 in perforated metal tray to a final product moisture level of less than 5 wt %. The dried material was coarse ground in a Prodeva Model 315-S crusher, milled in an MPI 666-F three stage roller mill and sieved with an Minox MTS 600DS3V to remove particles greater than 850 microns and smaller than 150 microns. 400 g of the sieved powder was then blended uniformly with 0.5 wt % Aerosil 200 fumed silica and 0.2 wt % aluminium sulfate, followed by the uniform spray application of a solution 0.1 wt % disodium cocoamphopropionate, 0.5 wt % tetraethyleneglycol dimethyether, and 1.0 wt % ethylene carbonate in 4 g of water, using a finely atomized spray from a Paasche VL sprayer while the SAP particles are fluidized in air and continuously mixed. All wt % values based on the weight of dry SAP powder. The coated material was then heated for 20 minutes at 180° C. in a General Signal/BM Model OV-510A-3 forced air oven.
In an insulated, flat-bottomed reaction vessel, 1866.7 g of 50% NaOH was added to 3090.26 g of distilled water and cooled to 25° C. 800 g of acrylic acid was then added to caustic solution and the solution again cooled to 25° C. A second solution of 1600 g of acrylic acid containing 4.8 g of triallyamine, 120.53 g of 50 wt % methoxypolyethyleneglycol(750)monomethacrylate in acrylic acid and 3.6 g of trimethylolpropanetriacrylate with 9 moles of ethoxylation were then added to the first solution, followed by cooling to 15° C., the addition of 24.0 g of hydroxymonoallyl ether with 10 moles of ethoxylation, and additional cooling to 5° C., all while stirring. The monomer solution was then polymerized with a mixture of 150 ppm hydrogen peroxide, 200 ppm azo-bis-(2-amidino-propene)dihydrochloride, 350 ppm sodiumpersulfate and 100 ppm sodium erythorbate (all as aqueous solutions) under adiabatic conditions and held near Tmax for 25 minutes. The resulting gel was chopped and extruded with a Hobarth 4M6 commercial extruder, followed by drying in a Procter & Schwartz Model 062 forced air oven at 175° C. for 10 minutes with upflow and 6 minutes with downflow air on a 20 in×40 in perforated metal tray to a final product moisture level of less than 5 wt %. The dried material was coarse ground in a Prodeva Model 315-S crusher, milled in an MPI 666-F three stage roller mill and sieved with an Minox MTS 600DS3V to remove particles greater than 850 microns and smaller than 150 microns. 400 g of the sieved powder was then blended uniformly with 0.5 wt % fumed alumina (Degussa Aluminaoxide C), followed by the uniform spray application of a solution containing 0.2 wt % sodium sulfate, 0.1 wt % cocomonoethanol amide with 4.5 moles ethoxylation, 0.5 wt % polyethylene glycol MW 600, and 0.5 wt % ethylene carbonate in 5 g of water, using a finely atomized spray while the SAP particles are fluidized in air. The coated material was then heated for 20 minutes at 180° C. in a General SignaVBM Model OV-510 A-3 forced air oven.
In an insulated, flat-bottomed reaction vessel, 1866.7 g of 50% NaOH was added to 3090.26 g of distilled water and cooled to 25° C. 800 g of acrylic acid was then added to caustic solution and the solution again cooled to 25° C. A second solution of 1600 g of acrylic acid containing 4.8 g of triallyamine, 120.53 g of 50 wt % methoxypolyethyleneglycol(750)monomethacrylate in acrylic acid and 3.6 g of trimethylolpropanetriacrylate with 9 moles of ethoxylation were then added to the first solution, followed by cooling to 15° C., the addition of 24.0 g of hydroxymonoallyl ether with 10 moles of ethoxylation, and additional cooling to 5° C., all while stirring. The monomer solution was then polymerized with a mixture of 150 ppm hydrogen peroxide, 200 ppm azo-bis-(2-amidino-propene)dihydrochloride, 350 ppm sodiumpersulfate and then 100 ppm sodium erythorbate (all aqueous solutions) under adiabatic conditions and held near Tmax for 25 minutes. The resulting gel was chopped and extruded with a Hobarth 4M6 commercial extruder, followed by drying in a Procter & Schwartz Model 062 forced air oven at 175° C. for 10 minutes with upflow and 6 minutes with downflow air on a 20 in×40 in perforated metal tray to a final product moisture level of less than 5 wt %. The dried material was coarse ground in a Prodeva Model 315-S crusher, milled in an MPI 666-F three stage roller mill and sieved with an Minox MTS 600DS3V to remove particles greater than 850 microns and smaller than 150 microns. 400 g of the sieved powder was then blended uniformly with 0.5 wt % fumed alumina (Degussa Aluminumaoxid C), followed by the uniform spray application of a solution containing 0.3 wt % aluminum sulfate, 0.1 wt % cocomonoethanol amide with 4.5 moles ethoxylation, 0.2 wt % polyethylene glycol MW 600, and 0.5 wt % ethylene carbonate in 5 g of water, using a finely atomized spray while the SAP particles are fluidized in air. The coated material was then heated for 20 minutes at 180° C. in a General Signal/BM Model OV-510 A-3 forced air oven.
In an insulated, flat-bottomed reaction vessel, 1866.7 g of 50% NaOH was added to 3090.26 g of distilled water and cooled to 25° C. 800 g of acrylic acid was then added to caustic solution and the solution again cooled to 25° C. A second solution of 1600 g of acrylic acid containing 4.8 g of triallyamine, 120.53 g of 50 wt % methoxypolyethyleneglycol(750)monomethacrylate in acrylic acid and 3.6 g of trimethylolpropanetriacrylate with 9 moles of ethoxylation were then added to the first solution, followed by cooling to 15° C., the addition of 24.0 g of hydroxymonoallyl ether with 10 moles of ethoxylation, and additional cooling to 5° C., all while stirring. The monomer solution was then polymerized with a mixture of 150 ppm hydrogen peroxide, 200 ppm azo-bis-(2-amidino-propene)dihydrochloride, 350 ppm sodiumpersulfate and then 100 ppm sodium erythorbate (all aqueous solutions) under adiabatic conditions and held near Tmax for 25 minutes. The resulting gel was chopped and extruded with a Hobarth 4M6 commercial extruder, followed by drying in a Procter & Schwartz Model 062 forced air oven at 175° C. for 10 minutes with upflow and 6 minutes with downflow air on a 20 in×40 in perforated metal tray to a final product moisture level of less than 5 wt %. The dried material was coarse ground in a Prodeva Model 315-S crusher, milled in an MPI 666-F three stage roller mill and sieved with an Minox MTS 600DS3V to remove particles greater than 850 microns and smaller than 150 microns. 400 g of the sieved powder was then blended uniformly with 0.5 wt % fumed alumina (Degussa Aluminumoxid C), followed by the uniform spray application of a solution containing 0.2 wt % aluminum sulfate, 0.1 wt % disodium cocoamphopropionate, 0.5 wt % tetraethyleneglycol dimethyl ether, and 1.0 wt % ethylene carbonate in 5 g of water, using a finely atomized spray while the SAP particles are fluidized in air. The coated material was then heated for 20 minutes at 180° C. in a General Signal/BM Model OV-510A-3 forced air oven.
Similar to Example 27 except 12.0 g of polyethylene glycol (300) diacrylate and 12.0 g of monoallyl ether acrylate with 10 moles of ethoxylation were used in the monomer solution,
In an insulated, flat-bottomed reaction vessel, 1866.7 g of 50% NaOH was added to 3090.26 g of distilled water and cooled to 25° C. 800 g of acrylic acid was then added to caustic solution and the solution again cooled to 25° C. A second solution of 1600 g of acrylic acid containing 120 g of 50 wt % methoxypolyethyleneglyco (750) monomethacrylate in acrylic acid and 6.0 g of trimethylolpropanetriacrylate with 3 moles of ethoxylation were then added to the first solution, followed by cooling to 15° C., the addition of 10.8 g of hydroxymonoallyl ether with 10 moles of ethoxylation, and additional cooling to 5° C., all while stirring. The monomer solution was then polymerized with a mixture of 100 ppm hydrogen peroxide, 125 ppm azo-bis-(2-amidino-propene)dihydrochloride, 300 ppm sodiumpersulfate and then 30 ppm sodium erythorbate (all aqueous solutions) under adiabatic conditions and held near Tmax for 25 minutes. The resulting gel was chopped and extruded with a Hobarth 4M6 commercial extruder, followed by drying in a Procter & Schwartz Model 062 forced air oven at 175° C. for 10 minutes with upflow and 6 minutes with downflow air on a 20 in×40 in perforated metal tray to a final product moisture level of less than 5 wt %. The dried material was coarse ground in a Prodeva Model 315-S crusher, milled in an MPI 666-F three stage roller mill and sieved with an Minox MTS 600DS3V to remove particles greater than 850 microns and smaller than 150 microns. 400 g of the sieved powder was then blended uniformly with 0.5 wt % fumed silica Aerosil 200 and 1.0 wt % kaolin (Neogen DGH), followed by the uniform spray application of a solution containing 0.01 wt % aluminum sulfate, and 1.0 wt % ethylene carbonate in 4 g of water, using a finely atomized spray while the SAP particles are fluidized in air. The coated material was then heated for 135 minutes at 175° C. in a General Signal/BM Model OV-510 A-3 forced air oven.
TABLE 1 CRC GBP G′ AAP (g/g) (×10 − 9 cm2) (dynes/cm2) (g/g)
Example 1 29 661 5568 19.3 Example 2 27.6 910 6386 20.4 Example 3 26.9 927 7746 20.1 Example 4 27 1194 6183 21.5 Example 5 25.1 1252 8436 22.05 Example 6 24 1589 8797 22.1 Example 7 30.1 554 6011 19.1 Example 8 27.8 928 7966 21.2 Example 9 26 1100 7999 21.4 Example 10 28.3 675 4248 18.9 Example 11 24.4 2039 6463 21.9 Example 12 23.1 1852 7312 22.2 Example 13 28.4 947 4472 19.1 Example 14 25.8 1510 4639 19.5 Example 15 24.2 2132 5536 20.4 Example 16 31.3 647 4813 19.7 Example 17 27.7 1055 5497 20.1 Example 18 26.4 1457 6110 21.1 Example 19 30.2 457 3484 18.5 Example 20 29.6 592 4275 20.5 Example 21 27.9 945 5017 20.1 Example 22 32.2 382 3890 19.6 Example 23 28.1 1091 5222 21.0 Example 24 26.5 1278 5862 20.5 Example 25 32 390 6227 20.3 Example 26 30 500 6797 21.5 Example 27 30 612 6899 21.2 Example 28 29 862 7777 22.4 Example 29 31 836 5182 19.7 Example 30 27.8 1456 6872 20.8 Example 31 31 736 6011 19.4
G′ AAP CRC (dynes/ (0.7 (g/g) cm2) GBP psi)
Sanwet 770H 32.4 4305 58 22.3 Hy-Sorb M 7055 33.1 4276 55 24.2 Hysorb 100 26.3 5649 95 24 BASF 2300 33.4 4034 58 19.7 BASF 7050 31.1 5033 62 26.5 BASF 2260 23.9 9025 553 19.5 BASF ASAP 2000 31.4 3688 50 21 Sumitumo SA60 32.5 3196 37 13 Kolon GS3400 30.4 6818 186 22.6 Kolon GS3000 38.9 2811 20 22 DryTech 2035M 30.4 7138 35 15.1 DOW S100R 28.2 6032 88 24.3 Aqualic CAB 34.4 3356 176 17.4 SAP from Pampers Baby Dry diapers 28.4 5746 143 20.6 SAP from Pampers Premium diapers 30.8 5573 130 23.3 SAP from Pampers Cruisers 28.9 6866 154 22.2 SAP from Luv's diapers 27.3 6954 137 22.0 SAP from Huggies UltraTrim diaper 21.5 11490 408 20.9 SAP from Huggies Overnites 29.6 6889 110 10.5 SAP from Huggies Supremes 22.2 11360 325 18.0 SAP from White Cloud diaper 22.1 9785 435 14.4 SAP from White Cloud training pants 22.3 9490 373 13.3 SAP from Walgreens UltraValue diapers 26.9 7590 278 15.9 SAP from DriBottoms diapers 22.4 9545 273 14.4 SAP recovered from PaperPak Adult 39.5 4554 10 13.1 Briefs
83. A superabsorbent polymer composition comprising a polymer consisting essentially of:
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 particle surface;
f) from about 0.01 to 10 wt % based on dry polymer powder weight of a water-soluble polymer including a polyvinyl portion; and
g) from about 0.01 to about 5 wt % based on dry polymer powder weight of an insoluble, inorganic phosphate powder wherein the composition has a degree of neutralization of more than about 25%; and a gel bed permeability of at least about [54000e−0.18x+75]×10−9 cm2 where x is the numeric value of centrifuge retention capacity.
84. A superabsorbent polymer composition according to claim 83 wherein the gel bed permeability is at least about [54000e−0.175x+100]×10−9 cm2.
85. A superabsorbent polymer composition according to claim 83 wherein the gel bed permeability is at least about [54000e−0.17x+100]×10−9 cm2.
86. A superabsorbent polymer composition according to claim 83 wherein the gel bed permeability is at least about [54000e−0.165x+100]×10−9 cm2.
87. A superabsorbent polymer composition according to claim 83 wherein the centrifuge retention capacity is greater than about 30 g/g.
88. A superabsorbent polymer composition according to claim 83 wherein the gel bed permeability is at least about 400×10−9 cm2.
89. 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; an insoluble inorganic phosphate powder, and water-soluble polymer including a polyvinyl portion, wherein the superabsorbent polymer has a gel bed permeability of at least about [54000e−0.18x+75]×10−9 cm2. where x is the numeric value of centrifuge retention capacity.
90. A superabsorbent polymer composition according to claim 89 wherein the gel bed permeability is at least about 400×10−9 cm2.
91. A superabsorbent polymer composition according to claim 89 wherein the gel bed permeability is at least about [54000e−0.175x+100]×10−9 cm2.
92. A superabsorbent polymer composition according to claim 89 wherein the gel bed permeability is at least about [54000e−0.17x+100]×10−9 cm2.
93. A superabsorbent polymer composition according to claim 89 wherein the gel bed permeability is at least about [54000e−0.165x+100]×10−9 cm2.
94. A superabsorbent polymer composition according to claim 89 wherein the centrifuge retention capacity is greater than about 30 g/g.
95. A superabsorbent polymer composition according to claim 89 having the characteristics of centrifuge retention capacity from about 30 g/g to about 36 g/g; and a gel bed permeability from about 450×10−9 cm2 to about 800×10−9 cm2.
96. A superabsorbent polymer composition comprising a polymer consisting essentially of:
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
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 about 30 wt % based on dry polymer powder weight of a from 0 to about 30 wt. % of water-soluble polymer including a polyvinyl portion; and
g) from about 0.01 to about 5 wt % based on dry polymer powder weight of an insoluble, inorganic phosphate powder wherein the composition has, a degree of neutralization of more than about 25%; having the characteristics of centrifuge retention capacity from about 30 to about 36 g/g, and a gel bed permeability of about [54000e−0.18x+75]×10−9 cm2 or more where x is the numeric value of centrifuge retention capacity.
97. A superabsorbent polymer composition according to claim 96 where the gel bed permeability is at least about 400×10−9 cm2.
Publication number: 20070167560
Patent Grant number: 7795345
Inventors: Scott Smith (Greensboro, NC), Mark Joy (Greensboro, NC), Whei-Neen Hsu (Greensboro, NC), Markus Frank (Baden-Baden)
Application Number: 11/562,760
Current U.S. Class: 524/556.000; 524/430.000; 524/431.000; 524/432.000; 525/194.000; 526/317.100; 526/240.000; 526/318.200
International Classification: C08L 31/00 (20060101);