US3861031A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making a moisture-sensitive element
Assignee: RIKEN
•
Filing: 1974-05-01
•
Granted: 1975-01-21
•
Expires: 1994-05-01
Abstract
Abstract Disclosed is a method of making a moisture-sensitive element having an increased sensitivity to humidity with minimum secular variation of electric characteristics. The method comprises the steps of subjecting an aluminum matrix to electrolytic treatment to produce a film of aluminum oxide on the matrix, removing the film from the matrix, heat treating the film, and attaching electrodes to opposite surfaces of the film.
Inventors
- 👤 Akio Furuichi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:28
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/02; G01N27/04; G01N27/12; G01N27/121; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49082; Y10T29/49101
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
58 words
A METHOD OF MAKING A MOISTURE-SENSITIVE ELEMENT COMPRISING THE STEPS OF:SUBJECTING AN ALUMINIUM MATRIX TO ELECTROLYTIC TREATMENT OF PRODUCE A POROUS FILM OF ALUMINIUM OXIDE ON SAID MATRIX; REMOVING SAID ALUMINIUM OXIDE FILM FROM SAID MATRIX; SUBJECTING SAID ALUMINUM OXIDE FILM TO A HEAT TREATMENT; AND ATTACHING METAL ELECTRODES TO THE OPPOSITE SURFACE OF SAID ALUMINIUM OXIDE FILM.
Claim 2
Independent Claim
58 words
A METHOD OF MAKING A MOISTURE-SENSITIVE ELEMENT COMPRISING THE STEPS OF:SUBJECTING AN ALUMINIUM MATRIX TO ELECTROLYTIC TREATMENT OF PRODUCE A POROUS FILM OF ALUMINIUM OXIDE ON SAID MATRIX; REMOVING SAID ALUMINIUM OXIDE FILM FROM SAID MATRIX; SUBJECTING SAID ALUMINUM OXIDE FILM TO A HEAT TREATMENT; AND ATTACHING METAL ELECTRODES TO THE OPPOSITE SURFACE OF SAID ALUMINIUM OXIDE FILM.
Claim 3
Dependent Claim
35 words
A method of making a moisture-sensitive element according to claim 1 wherein it further comprises the steps of subjecting said aluminium oxide film to a hot water treatment as a subsequent to said heat treatment.
Claim 4
Dependent Claim
23 words
A method of making a moisture-sensitive element according to claim 1 wherein said heat treatment is conducted at 900* C or higher temperature.
Claim 5
Dependent Claim
33 words
A method of making a moisture-sensitive element according to claim 2 wherein said hot water treatment includes exposing said aluminium oxide film to steam and soaking said aluminium oxide film in boiling water.
Claim 6
Dependent Claim
18 words
A method of making a moisture-sensitive element according to claim 1 wherein said electrolytic treatment is anodic oxidation.
Claim 7
Dependent Claim
37 words
A method of making a moisture-sensitive element according to claim 1 wherein an aqueous solution of mercuric chloride or methanol solution of bromide or iodine is used to remove said aluminium oxide film from said aluminium matrix.
References Cited (Backward Citations)
US2237006A
Cited
US3026255A
Cited
US3440372A
Cited
US3488262A
Cited
US3406106A
Cited
US3496075A
Cited
US3550057A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-01-20 | 1978-07-22 | 1979-01-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-20 | 1982-07-22 | 1983-01-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-20 | 1986-07-22 | 1987-01-21 | $7700.00 | Window Closed / Lapsed |