Patent US3793715A successfully refreshed from Google Patents.
US3793715A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing high-quality electrets
Assignee: Kureha Corp
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Filing: 1971-08-26
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Granted: 1974-02-26
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Expires: 1991-08-26
Abstract
Abstract A process for producing a high quality electret comprising treating an electret having a heterocharge and a homocharge prepared from a molded resin in the presence of water to decay the unstable component of the heterocharge and the homocharge and maintain only a stable heterocharge.
Inventors
- 👤 N Murayama
- 👤 M Fukuda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:41
CPC Classifications
H; H01; H01G; H01G7/00; H01G7/02; H01G7/021; H01G7/023; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
17 words
The process of claim 1, wherein said water is in the form of an aqueous electrolyte solution.
Claim 2
Dependent Claim
14 words
The process of claim 1, wherein said water is in the form of steam.
Claim 3
Dependent Claim
9 words
The electret produced by the process of claim 1.
References Cited (Backward Citations)
US2986524A
Cited
US3316620A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-25 | 1977-08-27 | 1978-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-25 | 1981-08-27 | 1982-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-25 | 1985-08-27 | 1986-02-26 | $7700.00 | Window Closed / Lapsed |