Patent US4801475A successfully refreshed from Google Patents.
US4801475A
Expired / Lapsed
US
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Method of hydrophilic coating of plastics
Assignee: Fujifilm Holdings Corp
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Filing: 1984-08-23
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Granted: 1989-01-31
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Expires: 2004-08-23
Abstract
Abstract Plastics, particularly a method hydrophilic coating of plastics, for example, a contact lens, with a lubricating and visually acute mucopolysaccharide film which is immobilized upon the surface of the plastic for the lifetime of the plastic. A preferred method includes first coating the plastic with an aqueous solution of a mucopolysaccharide, drying by applying a water-miscible solvent, then crosslinking and permanently immobilizing the first coating upon the plastic by applying a solution of catalyzed organic soluble aliphatic polyisocyanate.
Inventors
- 👤 Gregory Halpern
- 👤 Charles Campbell
- 👤 Ellington M. Beavers
- 👤 Huk Y. Cheh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:41
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/08; C08G18/28; C08G18/40; C08G18/62; C08G18/6216; C08G18/622; C08G18/6225; C08G18/6229; C08G18/64; C08G18/6484; C08G18/70; C08G18/72; C08G18/728; C08J; C08J7/00; C08J7/04; C08J7/0427; C08J7/043; C08J7/056; C08J2475/00
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
88 words
Method of hydrophilic coating of normally hydrophobic plastics to add wetability and lubricity comprising the steps of: (a) first coating a surface of the plastic with an aqueous solution of a mucopolysaccharide to define a wet film, then; (b) dehydrating water from said solution by applying a water-miscible solvent so as to precipitate mucopolysaccharide as a film onto said plastic surface, and drying said film; (c) subsequently to said drying, crosslinking and immobilizing said first coating upon the plastic by applying a solution of catalyzed organic-soluble aliphatic polyisocyanate.
Claim 2
Dependent Claim
88 words
Method of hydrophilic coating of normally hydrophobic plastics to add wetability and lubricity comprising the steps of: (a) first coating a surface of the plastic with an aqueous solution of a mucopolysaccharide to define a wet film, then; (b) dehydrating water from said solution by applying a water-miscible solvent so as to precipitate mucopolysaccharide as a film onto said plastic surface, and drying said film; (c) subsequently to said drying, crosslinking and immobilizing said first coating upon the plastic by applying a solution of catalyzed organic-soluble aliphatic polyisocyanate.
Claim 3
Dependent Claim
79 words
Method of hydrophilic colating of normally hydrophobic plastics to add wetability and lubricity comprising the steps of: (a) first coating the plastic with an aqueous solution of sodium hyaluronate, then; (b) dehydrating water from said solution by applying a water-miscible solvent so as to precipitate sodium hyaluronate as a film onto said plastic surface and drying said film; and, (c) subsequently to said drying, crosslinking and immobilizing said first coating by applying a solution of catalyzed organic-soluble aliphatic polyisocyanate.
Claim 4
Dependent Claim
79 words
Method of hydrophilic colating of normally hydrophobic plastics to add wetability and lubricity comprising the steps of: (a) first coating the plastic with an aqueous solution of sodium hyaluronate, then; (b) dehydrating water from said solution by applying a water-miscible solvent so as to precipitate sodium hyaluronate as a film onto said plastic surface and drying said film; and, (c) subsequently to said drying, crosslinking and immobilizing said first coating by applying a solution of catalyzed organic-soluble aliphatic polyisocyanate.
Claim 5
Dependent Claim
53 words
Method of hydrophilic coating of plastics as in claim 2, wherein a 100-mil coating is cast from 0.5% aqueous solution of sodium hyaluronate and said dehydrating step comprises applying a water-miscible solvent selected from the group consisting of acetone, methyl alcohol, methyl ethyl ketone, and ethyl alcohol, and said polyisocyanate is Desmodur N.
Claim 6
Dependent Claim
19 words
Method of hydrophilic coating of plastics as in claim 3, wherein said Desmodur N is catalyzed with dibutyltin dilaurate.
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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) | 1992-01-31 | 1992-08-01 | 1993-01-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-01-31 | 1996-08-01 | 1997-01-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-01-31 | 2000-08-01 | 2001-01-31 | $7700.00 | Window Closed / Lapsed |