US4058639A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making fluorescent lamp
Assignee: GTE Sylvania Inc
•
Filing: 1975-12-09
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Granted: 1977-11-15
•
Expires: 1995-12-09
Abstract
Abstract A film of colloidal alumina is deposited on a fluorescent lamp envelope from a suspension containing nitrocellulose resin. After the film has dried, a phoshor coating is deposited thereon without the need of baking the film.
Inventors
- 👤 Willy P. Schreurs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 01:58
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/02
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
89 words
The process of manufacturing a fluorescent lamp of the type having a protective coating on the inner surface of the lamp envelope and a phosphor coating deposited on the protective coating comprising the steps of preparing a dispersion of finely powdered alumina in a solution of nitrocellulose in a highly polar solvent, the dispersion containing no phosphor, applying said dispersion to the inner surface of the lamp envelope to form said protective coating, drying said protective coating and depositing said phosphor coating thereon without first lehring the protective coating.
Claim 2
Dependent Claim
89 words
The process of manufacturing a fluorescent lamp of the type having a protective coating on the inner surface of the lamp envelope and a phosphor coating deposited on the protective coating comprising the steps of preparing a dispersion of finely powdered alumina in a solution of nitrocellulose in a highly polar solvent, the dispersion containing no phosphor, applying said dispersion to the inner surface of the lamp envelope to form said protective coating, drying said protective coating and depositing said phosphor coating thereon without first lehring the protective coating.
Claim 3
Dependent Claim
13 words
The process of claim 1 wherein said dispersion also includes an ampholytic surfactant.
Claim 4
Dependent Claim
13 words
The process of claim 2 wherein said ampholytic surfactant is an ethoxylated amine.
Claim 5
Dependent Claim
12 words
The process of claim 1 wherein said highly polar solvent is 2-ethoxyethanol.
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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) | 1980-11-14 | 1981-05-16 | 1981-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-11-14 | 1985-05-16 | 1985-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-11-14 | 1989-05-16 | 1989-11-15 | $7700.00 | Window Closed / Lapsed |