US5419955A
Expired / Lapsed
US
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Method for immobilizing superabsorbent polymer and products derived therefrom
Assignee: CNA Holdings LLC
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Filing: 1993-06-17
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Granted: 1995-05-30
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Expires: 2013-06-17
Abstract
Abstract The present invention provides super absorbent materials in the form of sheets or fibers made from high melting polymers and having super absorbent polymer material dispersed uniformly throughout. The materials are capable of incorporating large amounts of super absorbent polymer and so demonstrate substantially improved absorbency and retention properties. The superabsorbent materials comprise a matrix material polymer selected from the group consisting of cellulose esters, acrylic acid esters, polyvinyl esters and copolymers of same, particles of superabsorbent material distributed throughout the matrix material and a plasticizer mixed into the matrix material.
Inventors
- 👤 Kenneth C. Ehrhardt
- 👤 John B. Hopkins, Jr.
- 👤 Joanne C. Maheras
- 👤 David R. McWilliams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:42
CPC Classifications
A; A61; A61L; A61L15/00; A61L15/16; A61L15/42; A61L15/60; A61L15/22; A61L15/24; A61L15/28; Y; Y10; Y10T; Y10T442/00; Y10T442/60; Y10T442/696; Y10T442/699
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
101 words
An absorbent material comprising a solution spinnable or solution extrudable matrix material, said matrix material being selected from the group consisting of cellulose esters, acrylic acid esters, polyvinyl esters, and copolymers and combinations of the foregoing, particles of a superabsorbent polymer distributed throughout the matrix material, and a plasticizer mixed into said matrix material, said plasticizer being present in an amount sufficient to enhance said absorbent materials's absorbency and retention properties, said plasticizer being selected from the group consisting of phthalate esters, phosphate esters, low molecular weight polypropylene glycol, oleates, sebacates, adipates, fatty acid esters, hydrocarbon derivatives sulfonamides, and glycol derivatives.
Claim 2
Dependent Claim
101 words
An absorbent material comprising a solution spinnable or solution extrudable matrix material, said matrix material being selected from the group consisting of cellulose esters, acrylic acid esters, polyvinyl esters, and copolymers and combinations of the foregoing, particles of a superabsorbent polymer distributed throughout the matrix material, and a plasticizer mixed into said matrix material, said plasticizer being present in an amount sufficient to enhance said absorbent materials's absorbency and retention properties, said plasticizer being selected from the group consisting of phthalate esters, phosphate esters, low molecular weight polypropylene glycol, oleates, sebacates, adipates, fatty acid esters, hydrocarbon derivatives sulfonamides, and glycol derivatives.
Claim 3
Dependent Claim
13 words
A molded or shaped article formed of the absorbent material of claim 1.
Claim 4
Dependent Claim
23 words
The absorbent material of claim 1 wherein said plasticizer being selected from the group consisting of phthalate esters, phosphate esters, and glycol derivatives.
Claim 5
Dependent Claim
13 words
The absorbent material of claim 1 wherein the plasticizer is a phthalate ester.
Claim 6
Dependent Claim
12 words
The absorbent material of claim 1 wherein the plasticizer is diethyl phthalate.
Claim 7
Dependent Claim
15 words
The absorbent material of claim 5 wherein diethyl phthalate comprises about 18% by weight solids.
Claim 8
Dependent Claim
30 words
The absorbent material of claim 1 wherein the matrix material is a cellulose ester selected from the group consisting of cellulose acetate, cellulose propionate, cellulose butyrate, and mixed esters thereof.
Claim 9
Dependent Claim
20 words
The absorbent material of claim 1 wherein the superabsorbent polymer constitutes at least about 40% by weight of the material.
Claim 10
Dependent Claim
20 words
The absorbent material of claim 1 wherein the superabsorbent polymer constitutes at least about 60% by weight of the material.
Claim 11
Dependent Claim
19 words
The absorbent material of claim 1 wherein the superabsorbent polymer is a sodium salt of a grafted starch polyacrylate.
Claim 12
Dependent Claim
114 words
An absorbent material comprising a solution spinnable or solution extrudable matrix material, said matrix material being selected from the group consisting of cellulose esters, acrylic acid esters, polyvinyl esters, and copolymers and combinations of the foregoing, particles of a superabsorbent polymer distributed throughout the matrix material and constituting greater than about 40% by weight solids of the absorbent material, and a plasticizer mixed into said matrix material, said plasticizer being present in an amount sufficient to enhance said absorbent material's absorbency and retention properties, said plasticizer being selected from the group consisting of phthalate esters, phosphate esters, low molecular weight polypropylene glycol, oleates, sebacates, adipates, fatty acid esters, hydrocarbon derivatives, sulfonamides, and glycol derivatives.
Claim 13
Dependent Claim
114 words
An absorbent material comprising a solution spinnable or solution extrudable matrix material, said matrix material being selected from the group consisting of cellulose esters, acrylic acid esters, polyvinyl esters, and copolymers and combinations of the foregoing, particles of a superabsorbent polymer distributed throughout the matrix material and constituting greater than about 40% by weight solids of the absorbent material, and a plasticizer mixed into said matrix material, said plasticizer being present in an amount sufficient to enhance said absorbent material's absorbency and retention properties, said plasticizer being selected from the group consisting of phthalate esters, phosphate esters, low molecular weight polypropylene glycol, oleates, sebacates, adipates, fatty acid esters, hydrocarbon derivatives, sulfonamides, and glycol derivatives.
Claim 14
Dependent Claim
13 words
A molded or shaped article formed of the absorbent material of claim 11.
Claim 15
Dependent Claim
31 words
The absorbent material of claim 11 wherein the matrix material is selected from the group consisting of cellulose acetate, cellulose propionate, cellulose butyrate, mixed esters thereof, polyvinyl acetate and polyethyl methacrylate.
Claim 16
Dependent Claim
23 words
The absorbent material of claim 11 wherein said plasticizer being selected from the group consisting of phthalate esters, phosphate esters, and glycol derivatives.
Claim 17
Dependent Claim
13 words
The absorbent material of claim 14 wherein the plasticizer is a phthalate ester.
Claim 18
Dependent Claim
12 words
The absorbent material of claim 14 wherein the plasticizer is diethyl phthalate.
Claim 19
Dependent Claim
15 words
The absorbent material of claim 16 wherein diethyl phthalate comprises about 18% by weight solids.
Claim 20
Dependent Claim
82 words
A composition comprising a stable suspension of a cellulose ester or a mixture of cellulose esters matrix material, particles of a superabsorbent polymer, and a plasticizer mixed into said matrix material, said plasticizer being present in an amount sufficient to enhance said absorbent material's absorbency and retention properties, said plasticizer being selected from the group consisting of phthalate esters, phosphate esters, low molecular weight polypropylene glycol, oleates, sebacates, adipates, fatty acid esters, hydrocarbon derivatives, sulfonamides, and glycol derivatives in a liquid carrier.
Claim 21
Dependent Claim
82 words
A composition comprising a stable suspension of a cellulose ester or a mixture of cellulose esters matrix material, particles of a superabsorbent polymer, and a plasticizer mixed into said matrix material, said plasticizer being present in an amount sufficient to enhance said absorbent material's absorbency and retention properties, said plasticizer being selected from the group consisting of phthalate esters, phosphate esters, low molecular weight polypropylene glycol, oleates, sebacates, adipates, fatty acid esters, hydrocarbon derivatives, sulfonamides, and glycol derivatives in a liquid carrier.
Claim 22
Dependent Claim
28 words
The composition of claim 18 wherein the cellulose ester matrix material is selected from the group consisting of cellulose acetate, cellulose propionate, cellulose butyrate, and mixed esters thereof.
Claim 23
Dependent Claim
113 words
A composition comprising a stable suspension of a matrix material, particles of a superabsorbent polymer and a plasticizer in a liquid carrier, the matrix material being selected from the group consisting of polyvinyl esters and polymers of acrylic acid esters, and the liquid carrier being selected from the group consisting of acetone, methanol, methylene chloride, and combinations thereof, and the plasticizer mixed into said matrix material, said plasticizer being present in an amount sufficient to enhance said absorbent material's absorbency and retention properties, said plasticizer being selected from the group consisting of phthalate esters, phosphate esters, low molecular weight polypropylene glycol, oleates, sebacates, adipates, fatty acid esters, hydrocarbon derivatives, sulfonamides, and glycol derivatives.
Claim 24
Dependent Claim
113 words
A composition comprising a stable suspension of a matrix material, particles of a superabsorbent polymer and a plasticizer in a liquid carrier, the matrix material being selected from the group consisting of polyvinyl esters and polymers of acrylic acid esters, and the liquid carrier being selected from the group consisting of acetone, methanol, methylene chloride, and combinations thereof, and the plasticizer mixed into said matrix material, said plasticizer being present in an amount sufficient to enhance said absorbent material's absorbency and retention properties, said plasticizer being selected from the group consisting of phthalate esters, phosphate esters, low molecular weight polypropylene glycol, oleates, sebacates, adipates, fatty acid esters, hydrocarbon derivatives, sulfonamides, and glycol derivatives.
Claim 25
Dependent Claim
130 words
A process for making an absorbent material containing a superabsorbent polymer comprising of steps of: solvating a matrix material in a suitable solvent, the matrix material being selected from the group consisting of cellulose esters, acrylic acid esters, polyvinyl esters, and copolymers and combination of the foregoing; mixing particles of a superabsorbent polymer and a plasticizer into said solvated matrix material to form a stable suspension and said plasticizer mixed into said matrix material, said plasticizer being present in an amount sufficient to enhance said absorbent material's absorbency and retention properties, said plasticizer being selected from the group consisting of phthalate esters, phosphate esters, low molecular weight polypropylene glycol, oleates, sebacates, adipates, fatty acid esters, hydrocarbon derivatives, sulfonamides, and glycol derivatives; cooling the stable suspension; and desolvating the stable suspension.
Claim 26
Dependent Claim
130 words
A process for making an absorbent material containing a superabsorbent polymer comprising of steps of: solvating a matrix material in a suitable solvent, the matrix material being selected from the group consisting of cellulose esters, acrylic acid esters, polyvinyl esters, and copolymers and combination of the foregoing; mixing particles of a superabsorbent polymer and a plasticizer into said solvated matrix material to form a stable suspension and said plasticizer mixed into said matrix material, said plasticizer being present in an amount sufficient to enhance said absorbent material's absorbency and retention properties, said plasticizer being selected from the group consisting of phthalate esters, phosphate esters, low molecular weight polypropylene glycol, oleates, sebacates, adipates, fatty acid esters, hydrocarbon derivatives, sulfonamides, and glycol derivatives; cooling the stable suspension; and desolvating the stable suspension.
Claim 27
Dependent Claim
24 words
The process of claim 21 wherein the stable suspension is formed by mixing the composition at high shear for at least about two hours.
Claim 28
Dependent Claim
159 words
A process for making an absorbent material containing a superabsorbent polymer comprising the steps of: solvating a matrix material in a suitable solvent, the matrix material being selected from the group consisting of cellulose esters acrylic acid esters, polyvinyl esters, and copolymers and combination of the foregoing; mixing particles of a superabsorbent polymer and a plasticizer, said plasticizer mixed into said matrix material, said plasticizer being present in an amount sufficient to enhance said absorbent material's absorbency and retention properties, said plasticizer being selected from the group consisting of phthalate esters, phosphate esters, low molecular weight polypropylene glycol, oleates, sebacates, adipates, fatty acid esters, hydrocarbons derivatives, sulfonamides, and glycol derivatives into said solvated matrix material; forming a stable suspension of said matrix material, solvent an superabsorbent polymer by high shear stirring at temperatures less than about 95° C. for about two hours; cooling the suspension to about -78° C. for at least about 6 hours; and desolvating the suspension.
Claim 29
Dependent Claim
159 words
A process for making an absorbent material containing a superabsorbent polymer comprising the steps of: solvating a matrix material in a suitable solvent, the matrix material being selected from the group consisting of cellulose esters acrylic acid esters, polyvinyl esters, and copolymers and combination of the foregoing; mixing particles of a superabsorbent polymer and a plasticizer, said plasticizer mixed into said matrix material, said plasticizer being present in an amount sufficient to enhance said absorbent material's absorbency and retention properties, said plasticizer being selected from the group consisting of phthalate esters, phosphate esters, low molecular weight polypropylene glycol, oleates, sebacates, adipates, fatty acid esters, hydrocarbons derivatives, sulfonamides, and glycol derivatives into said solvated matrix material; forming a stable suspension of said matrix material, solvent an superabsorbent polymer by high shear stirring at temperatures less than about 95° C. for about two hours; cooling the suspension to about -78° C. for at least about 6 hours; and desolvating the suspension.
Claim 30
Dependent Claim
22 words
The process of claim 23 wherein said plasticizer being selected from the group consisting of phthalate esters, phosphate esters, and glycol derivatives.
Claim 31
Dependent Claim
11 words
The process of claim 23 wherein the plasticizer is diethyl phthalate.
Claim 32
Dependent Claim
21 words
The process of claim 24 wherein the diethyl phthalate is added in sufficient quantity to comprise about 18% by weight solute.
Claim 33
Dependent Claim
26 words
The process of claim 22 wherein the cellulose ester is selected from the group consisting of cellulose acetate, celoulose propionate, cellulose butyrate, and mixed esters thereof.
Claim 34
Dependent Claim
38 words
The process of claim 22 wherein the suitable solvent is selected from the group consisting of acetone, methyl ethyl ketone, methyl acetate, ethyl acetate, propyl acetate, methyl formate, ethyl formate, propyl formate, methylene chloride, methanol, and combinations thereof.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1998-05-29 | 1998-11-28 | 1999-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-05-29 | 2002-11-28 | 2003-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-05-29 | 2006-11-28 | 2007-05-30 | $7700.00 | Window Closed / Lapsed |