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US4985467A Expired / Lapsed US ⏱️ 0.0 years remaining

Highly absorbent polyurethane foam

Assignee: SCOTFOAM Corp 1500 EAST SECOND STREET EDDYSTONE
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Filing: 1989-04-12
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Granted: 1991-01-15
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Expires: 2009-04-12
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Abstract

Abstract A highly hydrophilic polyurethane article, which is the skeletal network of a cellular polyurethane foam subjected to a reticulation process wherein the polyurethane contains up to 100 parts of a superabsorbent material per hundred parts of polyol used in preparing the polyurethane, is useful in absorbing and holding large amounts of aqueous liquids is prepared by: (a) mixing a polyisocyanate, a polyol and a blowing agent with a finely divided superabsorbent material which is insoluble in a liquid which the material absorbs and which absorbs at least 15 times its weight of said liquid, (b) reacting the polyisocyanate, polyol and blowing agent under foaming conditions to produce a foam of polyurethane which cmprises a multitude of gas cells or bubbles within the polyurethane matrix, (c) curing said foam of polyurethane, forming a cellular structure with windows or membranes of solid polyurethanes present between gas cells or bubbles, (d) removing the windows or membranes by thermal reticulation thereby leaving the skeletal structure of the cured polyurethane; and said article is useful wherever high absorption and retention of large quantities of aqueous liquids is needed, including diapers, surgical sponges, and so forth.

Inventors

  • 👤 David J. Kelly
  • 👤 Dai W. Kim

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-06 14:25
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/0061; C08J2375/00; C08J2375/04; Y; Y10; Y10S; Y10S521/00; Y10S521/905

Claims Analysis

Total Claims: 18
Claim 1
Independent Claim 41 words
A highly hydrophilic polyurethane article which is the skeletal network of a cellular polyurethane foam subjected to reticulation wherein the polyurethane contains about 1 to 100 parts of a superabsorbent material per hundred parts of polyol used in preparing the polyurethane.
Claim 2
Dependent Claim 41 words
A highly hydrophilic polyurethane article which is the skeletal network of a cellular polyurethane foam subjected to reticulation wherein the polyurethane contains about 1 to 100 parts of a superabsorbent material per hundred parts of polyol used in preparing the polyurethane.
Claim 3
Dependent Claim 22 words
The article according to claim 1 wherein the polyurethane contains 5 to 75 parts of superabsorbent material per hundred parts of polyol.
Claim 4
Dependent Claim 22 words
The article according to claim 1 wherein the polyurethane contains 10 to 50 parts of superabsorbent material per hundred parts of polyol.
Claim 5
Dependent Claim 22 words
The article according to claim 1 wherein the polyurethane contains 25 to 50 parts of superabsorbent material per hundred parts of polyol.
Claim 6
Dependent Claim 14 words
The article according to claim 1 wherein the superabsorbent material is a natural gum.
Claim 7
Dependent Claim 19 words
The article according to claim 1 wherein the superabsorbent material is a chemically modified cellulose or an acrylic polymer.
Claim 8
Dependent Claim 17 words
The article according to claim 6 wherein the superabsorbent material is sodium polyacrylate or starch-grafted sodium polyacrylate.
Claim 9
Dependent Claim 119 words
A process for producing a highly hydrophilic article comprises: (a) mixing a polyisocyanate, a polyol and a blowing agent with a finely divided superabsorbent material which is insoluble in a liquid which the material absorbs and which absorbs at least 15 times its weight of said liquid, (b) reacting the polyisocyanate, polyol and blowing agent under foaming conditions to produce a foam of polyurethane which comprises a multitude of gas cells or bubbles within the polyurethane matrix, (c) curing said foam of polyurethane, forming a cellular structure with windows or membranes of solid polyurethane present between gas cells or bubbles, then (d) removing the windows or membranes by thermal reticulation thereby leaving the skeletal structure of the cured polyurethane.
Claim 10
Dependent Claim 119 words
A process for producing a highly hydrophilic article comprises: (a) mixing a polyisocyanate, a polyol and a blowing agent with a finely divided superabsorbent material which is insoluble in a liquid which the material absorbs and which absorbs at least 15 times its weight of said liquid, (b) reacting the polyisocyanate, polyol and blowing agent under foaming conditions to produce a foam of polyurethane which comprises a multitude of gas cells or bubbles within the polyurethane matrix, (c) curing said foam of polyurethane, forming a cellular structure with windows or membranes of solid polyurethane present between gas cells or bubbles, then (d) removing the windows or membranes by thermal reticulation thereby leaving the skeletal structure of the cured polyurethane.
Claim 11
Dependent Claim 18 words
A process according to claim 8 wherein the blowing agent in step a) is an aqueous blowing agent.
Claim 12
Dependent Claim 24 words
A process according to claim 8 wherein the amount of superabsorbent material is from about 1 to 100 parts per hundred parts of polyol.
Claim 13
Dependent Claim 22 words
A process according to claim 8 wherein the amount of superabsorbent material is 5 to 75 parts per hundred parts of polyol.
Claim 14
Dependent Claim 22 words
A process according to claim 8 wherein the amount of superabsorbent material is 10 to 50 parts per hundred parts of polyol.
Claim 15
Dependent Claim 22 words
A process according to claim 8 wherein the amount of superabsorbent material is 25 to 50 parts per hundred parts of polyol.
Claim 16
Dependent Claim 14 words
A process according to claim 8 wherein the superabsorbent material is a natural gum.
Claim 17
Dependent Claim 19 words
A process according to claim 8 wherein the superabsorbent material is a chemically modified cellulose or an acrylic polymer.
Claim 18
Dependent Claim 17 words
A process according to claim 15 wherein the superabsorbent material is sodium polyacrylate or starch-grafted sodium polyacrylate.

References Cited (Backward Citations)

US3021290A Cited
US3175025A Cited
US3171820A Cited
US4359558A Cited
US4394930A Cited
US4521544A Cited
US4731391A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1994-01-14 1994-07-16 1995-01-15 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1998-01-14 1998-07-16 1999-01-15 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2002-01-14 2002-07-16 2003-01-15 $7700.00 Window Closed / Lapsed

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