US5143636A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Controlled-porosity piezoelectric ceramic
Assignee: Thales SA
•
Filing: 1991-07-11
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Granted: 1992-09-01
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Expires: 2011-07-11
Abstract
Abstract The invention is a process to manufacture a controlled-porosity ceramic material by synthesizing an aerogel produced by hypercritical drying of a high-porosity gel. Applications in the submarine acoustic field (active and passive sonars).
Inventors
- 👤 Philippe Gaucher
- 👤 Jean-Pierre Ganne
- 👤 Jean-Claude Dubois
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 20:25
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/46; C04B35/462; C04B35/465; C04B35/468; C04B35/4682; C04B35/48; C04B35/49; C04B35/491; C04B38/00; C04B38/0045; H; H10; H10N; H10N30/00; H10N30/01; H10N30/09; H10N30/093; H10N30/097; H10N30/80; H10N30/85; H10N30/852; H10N30/853; H10N30/8536; H10N30/8548; H10N30/8554; C04B2111/00; C04B2111/00474; C04B2111/00844; H10N30/07; H10N30/074; H10N30/077; H10N30/078; H10N30/092
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
56 words
A process to manufacture a controlled porosity piezoelectric ceramic, the process consisting of the following steps: synthesis of a gel in the presence of a solvent, synthesis, using an autoclave, of an aerogel by drying the gel at pressure and temperature conditions which are hypercritical for the solvent, production of the ceramic by calcining the aerogel.
Claim 2
Dependent Claim
56 words
A process to manufacture a controlled porosity piezoelectric ceramic, the process consisting of the following steps: synthesis of a gel in the presence of a solvent, synthesis, using an autoclave, of an aerogel by drying the gel at pressure and temperature conditions which are hypercritical for the solvent, production of the ceramic by calcining the aerogel.
Claim 3
Dependent Claim
31 words
A process to manufacture a piezoelectric ceramic as described in claim 1, in which the shape of the pores in the gel is controlled by using chelating molecules to orientate gelling.
Claim 4
Dependent Claim
23 words
A process to manufacture a piezoelectric ceramic as described in claim 2 in which the chelating molecules are acetyl-acetone or acetic acid molecules.
Claim 5
Dependent Claim
42 words
A process to manufacture a piezoelectric ceramic as described in any of claims 1 to 3 in which the gel is synthesized by mixing lead in the form of carboxylate and titanium and zirconium in the form of alcooxides in an alcohol.
Claim 6
Dependent Claim
42 words
A process of manufacturing a piezoelectric ceramic as described in any of claims 1 to 3 in which the gel is produced by mixing barium in the form of a carboxylate and titanium in the form of an alcooxide in an alcohol.
References Cited (Backward Citations)
GB1313091A
Cited
FR2223324A1
Cited
US3892580A
Cited
US4402927A
Cited
US4784794A
Cited
WO1988008360A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-09-01 | 1996-03-02 | 1996-09-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-09-01 | 2000-03-02 | 2000-09-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-09-01 | 2004-03-02 | 2004-09-01 | $7700.00 | Window Closed / Lapsed |