US4798607A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of crosslinking a polyurethane prosthesis with a haloalkylisocyante
Assignee: University of Liverpool
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Filing: 1987-06-15
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Granted: 1989-01-17
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Expires: 2007-06-15
Abstract
Abstract A process is disclosed for producing a medical prosthesis by forming the prosthesis from an uncrosslinked polyurethane and then at least partially crosslinking the polyurethane with a vaporizable halo alkylisocyanate. The haloalkylisocyanate (e.g. chloromethylisocyanate) is reacted with the uncrosslinked polyurethane at a temperature which will not degrade or soften the polyurethane, (in its uncrosslinked form) in order to crosslink the polyurethane.
Inventors
- 👤 Ian P. Middleton
- 👤 Jerzy Paprotny
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 06:45
CPC Classifications
A; A61; A61L; A61L27/00; A61L27/14; A61L27/18; C; C08; C08G; C08G18/00; C08G18/06; C08G18/08; C08G18/10; Y; Y10; Y10S; Y10S264/00; Y10S264/42; Y10S264/77; Y10S623/00; Y10S623/92; Y10S623/921; Y10S623/924; Y10S623/926
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
67 words
A process for producing a medical prosthesis, comprising forming the prosthesis from an uncross-linked polyurethane and then at least partially cross-linking the polyurethane with a cross-linking agent, by treating the prosthesis with a vaporizable halo alkyl isocyanate and reacting said isocyanate with said polyurethane by vaporizing the isocyanate at a temperature below that temperature at which the polyurethane in its uncross-linked form tends to degrade and soften.
Claim 2
Dependent Claim
67 words
A process for producing a medical prosthesis, comprising forming the prosthesis from an uncross-linked polyurethane and then at least partially cross-linking the polyurethane with a cross-linking agent, by treating the prosthesis with a vaporizable halo alkyl isocyanate and reacting said isocyanate with said polyurethane by vaporizing the isocyanate at a temperature below that temperature at which the polyurethane in its uncross-linked form tends to degrade and soften.
Claim 3
Dependent Claim
13 words
The process of claim 1 wherein the medical prosthesis is formed by molding.
Claim 4
Dependent Claim
17 words
The process of claim 2, wherein the cross-linking agent is incorporated into and molded with the polyurethane.
Claim 5
Dependent Claim
13 words
The process of claim 1, wherein the medical prosthesis is formed by dip-casting.
Claim 6
Dependent Claim
27 words
The process of claim 1, wherein the medical prosthesis is formed by electrostatically spinning a melt or solution of the polyurethane material onto an appropriately shaped former.
Claim 7
Dependent Claim
26 words
The process of claim 1, wherein the prosthesis is treated with the vaporization halo-alkyl isocyanate by immersing the prosthesis in a liquid containing the halo-alkyl isocyanate.
Claim 8
Dependent Claim
13 words
The process of claim 6, wherein the liquid comprises only the cross-linking agent.
Claim 9
Dependent Claim
27 words
The process of claim 6, wherein the liquid comprises a solution of the cross-linking agent in a solvent which will not dissolve or react with the polyurethane.
Claim 10
Dependent Claim
26 words
The process of claim 1, wherein the prosthesis is treated with the vaporizable halo-alkyl isocyanate by exposing the prosthesis to a vapor containing the halo-alkyl isocyanate.
Claim 11
Dependent Claim
12 words
The process of claim 1 wherein the halo-alkyl isocyanate is chloromethyl isocyanate.
Claim 12
Dependent Claim
15 words
The process of claim 1, wherein the cross-linking reaction takes place at approximately room temperature.
Claim 13
Dependent Claim
22 words
The process of claim 1, wherein the prosthesis is washed in water or an aqueous solution after treatment with the cross-linking agent.
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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) | 1992-01-17 | 1992-07-18 | 1993-01-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-01-17 | 1996-07-18 | 1997-01-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-01-17 | 2000-07-18 | 2001-01-17 | $7700.00 | Window Closed / Lapsed |