Patent US4127516A successfully refreshed from Google Patents.
US4127516A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydrophilic polyurethane foams with good wet strength
Assignee: WR Grace and Co
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Filing: 1977-02-28
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Granted: 1978-11-28
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Expires: 1997-02-28
Abstract
Abstract Disclosed herein is a polyurethane foam having good wet strength. The foam is prepared by reacting a urethane prepolymer with large amounts of water containing a poly(amino)urea and optionally other ingredients, e.g. surfactants. The poly(amino)urea is characterized as being the water soluble reaction product of a polyamine with a urethane prepolymer, said reaction product being further reacted with a crosslinking agent, e.g. epichlorohydrin.
Inventors
- 👤 Donald W. Larsen
- 👤 Louis L. Wood
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 17:37
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/83; C08G18/831; C08G18/08; C08G18/10; C08G18/12; C08G18/28; C08G18/40; C08G18/48; C08G18/4833; C08G18/50; C08G18/5021; C08G18/5036; C08G18/5042; C08G2110/00; C08G2110/0083; Y; Y10; Y10S; Y10S521/00; Y10S521/905
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
62 words
A method for preparing a hydrophilic foam having good wet strength comprising reacting, under foam-forming conditions: (A) a urethane prepolymer formed by capping a hydrophilic oxyalkylene polyol with an isocyanate; and (B) an aqueous dispersion containing from about 0.1 to about 5 parts of weight based on the weight of the prepolymer of an essentially linear polyurea reacted with a crosslinking agent.
Claim 2
Independent Claim
62 words
A method for preparing a hydrophilic foam having good wet strength comprising reacting, under foam-forming conditions: (A) a urethane prepolymer formed by capping a hydrophilic oxyalkylene polyol with an isocyanate; and (B) an aqueous dispersion containing from about 0.1 to about 5 parts of weight based on the weight of the prepolymer of an essentially linear polyurea reacted with a crosslinking agent.
Claim 3
Dependent Claim
21 words
A method as in claim 1 wherein the polyurea is the reaction product of a polyamine and a hydrophilic urethane prepolymer.
Claim 4
Dependent Claim
45 words
A method as in claim 1 wherein the reaction product of the polyurea with the crosslinking agent is water soluble and characterized as providing a viscosity of from about 200 to about 15,000 cps when dissolved in water at a concentration of 25 weight percent.
Claim 5
Dependent Claim
12 words
A method as in claim 1 wherein the crosslinking agent is epichlorohydrin.
Claim 6
Dependent Claim
12 words
A method as in claim 1 wherein the crosslinking agent is formalin.
Claim 7
Dependent Claim
22 words
A method as in claim 1 wherein the polyol portion of the prepolymer contains at least 40 mole percent of oxyethylene units.
Claim 8
Dependent Claim
22 words
A method as in claim 1 wherein the polyol portion of the prepolymer contains at least 75 mole percent of oxyethylene units.
Claim 9
Dependent Claim
17 words
A method as in claim 1 wherein the aqueous polyurea dispersion additionally has hydrophilic fibers dispersed therein.
Claim 10
Dependent Claim
54 words
A hydrophilic foam comprising the reaction product of: (A) a urethane prepolymer formed by capping a hydrophilic oxyalkylene polyol with an isocyanate; and (B) an aqueous dispersion containing from about 0.1 to about 5 parts of weight based on the weight of the prepolymer of an essentially linear polyurea reacted with a crosslinking agent.
Claim 11
Dependent Claim
54 words
A hydrophilic foam comprising the reaction product of: (A) a urethane prepolymer formed by capping a hydrophilic oxyalkylene polyol with an isocyanate; and (B) an aqueous dispersion containing from about 0.1 to about 5 parts of weight based on the weight of the prepolymer of an essentially linear polyurea reacted with a crosslinking agent.
Claim 12
Dependent Claim
21 words
A foam as in claim 9 wherein the polyurea is the reaction product of a polyamine and a hydrophilic urethane prepolymer.
Claim 13
Dependent Claim
45 words
A foam as in claim 9 wherein the reaction product of the polyurea with the crosslinking agent is water soluble and characterized as providing a viscosity of from about 200 to about 15,000 cps when dissolved in water at a concentration of 25 weight percent.
Claim 14
Dependent Claim
12 words
A foam as in claim 9 wherein the crosslinking agent is epichlorohydrin.
Claim 15
Dependent Claim
12 words
A foam as in claim 9 wherein the crosslinking agent is formalin.
Claim 16
Dependent Claim
22 words
A foam as in claim 9 wherein the polyol portion of the prepolymer contains at least 40 mole percent of oxyethylene units.
Claim 17
Dependent Claim
22 words
A foam as in claim 9 wherein the polyol portion of the prepolymer contains at least 75 mole percent of oxyethylene units.
Claim 18
Dependent Claim
17 words
A foam as in claim 9 wherein the aqueous polyurea dispersion additionally has hydrophilic fibers dispersed therein.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-11-27 | 1982-05-29 | 1982-11-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-11-27 | 1986-05-29 | 1986-11-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-11-27 | 1990-05-29 | 1990-11-28 | $7700.00 | Window Closed / Lapsed |