Patent FR927024A successfully refreshed from Google Patents.
US4534916A
Expired / Lapsed
US
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Method for the preparation of hydrophilic gels by monomer casting
Assignee: Czech Academy of Sciences
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Filing: 1984-04-06
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Granted: 1985-08-13
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Expires: 2004-04-06
Abstract
Abstract Hydrogels, e.g. hydrogel contact lens are prepared by casting, preferably spin casting, hydrophilic gels in a plastic mold, preferably polypropylene in the presence of a surface active agent.
Inventors
- 👤 Otto Wichterle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:11
CPC Classifications
B; B29; B29C; B29C33/00; B29C33/56; B29C33/60; B29D; B29D11/00; B29D11/00009; B29D11/00038; B29D11/00125; B29C41/00; B29C41/02; B29C41/04; B29C41/042; B29C41/045; B29K; B29K2033/00; B29K2033/04; B29K2823/00; B29K2823/10; B29K2823/12; B29L; B29L2011/00; B29L2011/0016; B29L2011/0041; Y; Y10; Y10S; Y10S525/00; Y10S525/937
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
53 words
In a process of preparing a hydrophilic gel article by monomer cast polymerization of a mixture containing a monoolefinic hydrophilic monomer in a plastic mold the improvement comprising including in the polymerizable monomer mixture a surface active agent in an amount effective to prevent grafting of the hydrophilic gel on the plastic mold.
Claim 2
Dependent Claim
53 words
In a process of preparing a hydrophilic gel article by monomer cast polymerization of a mixture containing a monoolefinic hydrophilic monomer in a plastic mold the improvement comprising including in the polymerizable monomer mixture a surface active agent in an amount effective to prevent grafting of the hydrophilic gel on the plastic mold.
Claim 3
Dependent Claim
14 words
A process according to claim 1 wherein the article is a hydrophilic contact lens.
Claim 4
Dependent Claim
12 words
A process according to claim 2 wherein the casting is centrifugal casting.
Claim 5
Dependent Claim
12 words
A process according to claim 1 wherein the casting is centrifugal casting.
Claim 6
Dependent Claim
16 words
A process according to claim 1 wherein the plastic mold is made of a hydrocarbon polymer.
Claim 7
Dependent Claim
16 words
A process according to claim 5 wherein the plastic mold is made of polyethylene or polypropylene.
Claim 8
Dependent Claim
20 words
A process according to claim 6 wherein there is employed up to 4 weight % of the surface active agent.
Claim 9
Dependent Claim
20 words
A process according to claim 7 wherein there is employed 0.1 to 3 weight % of the surface active agent.
Claim 10
Dependent Claim
31 words
A process according to claim 8 wherein the surface active agent has a hydrophobic predominantly hydrocarbon or completely hydrocarbon chain and either an ionizable group or a strongly hydrophilic nonionizable group.
Claim 11
Dependent Claim
20 words
A process according to claim 9 wherein the hydrophobic chain is a hydrocarbon chain having at least 6 carbon atoms.
Claim 12
Dependent Claim
16 words
A process according to claim 10 wherein the plastic mold is made of a hydrocarbon polymer.
Claim 13
Dependent Claim
15 words
A process according to claim 2 wherein the mold is made of a hydrocarbon polymer.
Claim 14
Dependent Claim
15 words
A process according to claim 12 wherein the mold is made of polyethylene or polypropylene.
Claim 15
Dependent Claim
20 words
A process according to claim 13 wherein there is employed 0.1 to 3 weight % of the surface active agent.
Claim 16
Dependent Claim
28 words
A process according to claim 14 wherein the surface active agent has at least 6 carbon atoms and either an ionizable group or a strongly hydrophilic nonionizable group.
Claim 17
Dependent Claim
42 words
A process according to claim 12 wherein there is employed 0.1 to 3 weight % of the surface active agent and the surface active agent has at least 6 carbon atoms and either an ionizable group or a strongly hydrophilic nonionizable group.
Claim 18
Dependent Claim
23 words
A process according to claim 16 wherein the hydrophilic monomer is a mono or polyalkylene glycol monoester of acrylic acid or methacrylic acid.
Claim 19
Dependent Claim
27 words
A process according to claim 17 wherein the polymerizable mixture includes a di or higher polyfunctional monomer in an amount effective to form a cross-linked hydrophilic gel.
Claim 20
Dependent Claim
20 words
A process according to claim 18 wherein the cross-linking agent is an alkylene glycol or polyalkylene glycol diacrylate or dimethacrylate.
References Cited (Backward Citations)
US2542386A
Cited
US3171869A
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US3944637A
Cited
GB1478455A
Cited
US4146696A
Cited
US4468184A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-08-12 | 1989-02-11 | 1989-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-08-12 | 1993-02-11 | 1993-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-08-12 | 1997-02-11 | 1997-08-13 | $7700.00 | Window Closed / Lapsed |