Patent US4450198A successfully refreshed from Google Patents.
US4450198A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Microporous film with polymer in pores for regulating passage of fluid
Assignee: Alza Corp
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Filing: 1981-08-17
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Granted: 1984-05-22
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Expires: 2001-08-17
Abstract
Abstract A system is disclosed for dispensing an useful agent. The system comprises (1) means for storing an agent, (2) an agent stored in the means, (3) means for releasing agent from the system, (4) means for absorbing fluid into the system surrounding the storing means, and (5) means for admitting fluid into the system. In operation fluid is admitted into the system by the admitting means cooperating with the absorbing means, causing it to increase in dimensions and apply force against the storing means, which force urges the storing means to decrease its dimensions and correspondingly dispense agent through the releasing means from the system. Laminates are disclosed useful for manufacturing the system.
Inventors
- 👤 Alan S. Michaels
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 08:29
CPC Classifications
A; A61; A61J; A61J3/00; A61J3/07; A61K; A61K9/00; A61K9/0002; A61K9/0004; Y; Y10; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/249978; Y10T428/31504; Y10T428/31721; Y10T428/31725; Y10T428/31855
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
60 words
A microporous film comprising a microporous polymer selected from the group consisting of a microporous polyolefin, polyamide, polycarbonate, polyester, polystyrene, polysulphone, polyimide, polyvinyl chloride, polyaldehyde, polyarylate, polyhaloolefin polyacetyl, polyacrylate, and polyurethane, housing in its micropores a solid polymer selected from the group consisting of polyhydroxylalkyl acrylate, polyhydroxyalkyl methacrylate, polyacrylamide, poly(methacrylamide), polyvinyl pyrrolidone, polyvinyl alcohol, polyvinyl lactam acrylate, and polyvinyl piperidone.
Claim 2
Dependent Claim
60 words
A microporous film comprising a microporous polymer selected from the group consisting of a microporous polyolefin, polyamide, polycarbonate, polyester, polystyrene, polysulphone, polyimide, polyvinyl chloride, polyaldehyde, polyarylate, polyhaloolefin polyacetyl, polyacrylate, and polyurethane, housing in its micropores a solid polymer selected from the group consisting of polyhydroxylalkyl acrylate, polyhydroxyalkyl methacrylate, polyacrylamide, poly(methacrylamide), polyvinyl pyrrolidone, polyvinyl alcohol, polyvinyl lactam acrylate, and polyvinyl piperidone.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-05-22 | 1987-11-21 | 1988-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-22 | 1991-11-21 | 1992-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-22 | 1995-11-21 | 1996-05-22 | $7700.00 | Window Closed / Lapsed |