US4183884A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for manufacturing hydrogel tubes
Assignee: Czech Academy of Sciences
•
Filing: 1976-11-01
•
Granted: 1980-01-15
•
Expires: 1996-11-01
Abstract
Abstract There is disclosed a method of producing hydrogel tubes comprising partially hydrolyzing an acrylonitrile-containing polymer in an inorganic acidic solvent solution at temperature of about -10° to 50° C., extruding said hydrolyzed polymer solution through a circular nozzle into an aqueous coagulating bath, the same or similar coagulating bath simultaneously being fed through a central tube or pin of the nozzle. Preferably, the surface of the tube is made very slippery in wet condition, by treating it with chemical agents causing either a further hydrolysis or other reaction leading to carboxylic, sulfonic or sulfuric groups, or an esterification with polyols such as glycerol, glycols or polyvinyl alcohol, preferably with simultaneous sulfonation or sulfuration.
Inventors
- 👤 Otto Wichterle
- 👤 Artur Stoy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 19:04
CPC Classifications
C; C08; C08J; C08J7/00; C08J7/12; B; B29; B29C; B29C48/00; B29C48/03; B29C48/09; B29C48/10; B29C48/25; B29C48/88; B29C48/919; C08J2333/00; C08J2333/18; C08J2333/20; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2973; Y10T428/2975
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
190 words
The method of forming an elastic hydrophilic tube from a rubbery-hydrogel, consisting of the steps of: (a) contacting an acrylonitrile containing polymer with a solvent solution of an acid or a salt, wherein said solvent is selected from the group consisting of mineral acids and salts capable of dissolving polyacrylonitrile, and subjecting said polymer to controlled partial acid hydrolysis in said solvent, terminating said acid hydrolysis and coagulating the solution of said polymer in a pre-extrusion coagulating bath, and redissolving the coagulated polymer in an organic solvent, (b) extruding the acid hydrolyzed polymer solution in the form of a tube, while feeding a coagulating bath into the interior of the formed tube, into an aqueous coagulation bath, said polymer solution being viscous in form, (c) treating and super-hydrophilizing the surface of the formed tube, while in a swollen state, with a hydrolyzing agent, wherein said polymer is a multi-block copolymer of acrylonitrile with acrylamide, which under X-ray diffraction analysis reveals a pattern of crystalline or quasi-crystalline polyacrylonitrile with an interplanar periodicity of 5.1 A on a background of an amorphous phase formed by acrylamide and/or acrylic acid polymer chain segments.
Claim 2
Independent Claim
190 words
The method of forming an elastic hydrophilic tube from a rubbery-hydrogel, consisting of the steps of: (a) contacting an acrylonitrile containing polymer with a solvent solution of an acid or a salt, wherein said solvent is selected from the group consisting of mineral acids and salts capable of dissolving polyacrylonitrile, and subjecting said polymer to controlled partial acid hydrolysis in said solvent, terminating said acid hydrolysis and coagulating the solution of said polymer in a pre-extrusion coagulating bath, and redissolving the coagulated polymer in an organic solvent, (b) extruding the acid hydrolyzed polymer solution in the form of a tube, while feeding a coagulating bath into the interior of the formed tube, into an aqueous coagulation bath, said polymer solution being viscous in form, (c) treating and super-hydrophilizing the surface of the formed tube, while in a swollen state, with a hydrolyzing agent, wherein said polymer is a multi-block copolymer of acrylonitrile with acrylamide, which under X-ray diffraction analysis reveals a pattern of crystalline or quasi-crystalline polyacrylonitrile with an interplanar periodicity of 5.1 A on a background of an amorphous phase formed by acrylamide and/or acrylic acid polymer chain segments.
Claim 3
Dependent Claim
22 words
The method of claim 1, wherein said solvent solution is at a temperature in the range from about 10° to 50° C.
Claim 4
Dependent Claim
24 words
The method of claim 2, wherein said solvent solution is at a temperature in the range from about 0° to below about 25° C.
Claim 5
Dependent Claim
22 words
The method of claim 1, wherein said solvent is selected from the group consisting of nitric acid, sulfuric acid and zinc chloride.
Claim 6
Dependent Claim
41 words
The method of claim 1, wherein said polymer is a 85 to 99% polymer of acrylonitrile and a monomer selected from the group consisting of methacrylamide, acrylamide, acrylic acid, methacrylic acid, vinyl pyridine, vinyl pyrrolidone, methyl methacrylate, methacrylonitrile, and vinyl carbazole.
Claim 7
Dependent Claim
27 words
The method of claim 1, wherein said organic solvent is selected from the group consisting of wet dimethyl sulfoxide, wet dimethyl formamide and wet cyclic ethylene carbonate.
Claim 8
Dependent Claim
32 words
The method of claim 1, wherein said hydrolyzing agent in step (c) is selected from the group consisting of nitrous acid, alkali metal hydroxide, chlorosulfonic acid, fuming sulfuric acid and suflur trioxide.
Claim 9
Dependent Claim
18 words
The method of claim 7, wherein said hydrolyzing agent includes sulfuric acid and a lower alkyl polyhydric alcohol.
Claim 10
Dependent Claim
15 words
The method of claim 1, wherein a pharmaceutical agent is incorporated into the hydrophilic tube.
Claim 11
Dependent Claim
22 words
The method of claim 9, wherein said pharmaceutical agent is added to a solution of the polymer during, or prior to coagulation.
References Cited (Backward Citations)
US3862452A
Cited
US3679355A
Cited
US3728072A
Cited
US3674628A
Cited
US3802954A
Cited
US3864323A
Cited
US3812071A
Cited
US3799356A
Cited
US3733386A
Cited
US3871950A
Cited
US3897382A
Cited
US4021382A
Cited
US4061821A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-01-14 | 1983-07-16 | 1984-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-01-14 | 1987-07-16 | 1988-01-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-01-14 | 1991-07-16 | 1992-01-15 | $7700.00 | Window Closed / Lapsed |