US3833392A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coating composition and method for preparing water-soluble cellulosic polymer coating compositions for coating fluorescent tubes
Assignee: Philips North America LLC
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Filing: 1971-08-09
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Granted: 1974-09-03
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Expires: 1991-08-09
Abstract
Abstract Method of preparing suspension for coating discharge devices with finely divided particulate material, wherein an aqueous solution of a hydroxy alkyl cellulose is initially purified by passing the solution through an ion exchange system, and the particulate material to be coated is thereafter suspended in the purified solution. The resulting coating composition has an extremely low level of impurity material which, if present, could impair the performance of the completed discharge device, after combustion.
Inventors
- 👤 R Luck
- 👤 D Davies
- 👤 R Repsher
- 👤 G Gainer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:14
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/02; C08; C08K; C08K3/00; C08K3/18; C08K3/20; C08K3/22; C08K3/32; C08K5/00; C08K5/04; C08K5/05; C08K9/00; C08K9/08
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
23 words
The method as specified in claim 1 wherein the hydroxy alkyl cellulose used in said aqueous solution consists essentially of hydroxy propylmethyl cellulose.
Claim 2
Dependent Claim
27 words
The method as specified in claim 1, wherein prior to purifying said aqueous solution, a wetting agent, a defoaming agent, and a plasticizing agent are added thereto.
Claim 3
Dependent Claim
70 words
A coating composition having a level of dissolved salts less than 0.0001 percent for applying a substantially uniform thin layer of inorganic particles onto the interior surface of a discharge lamp envelope, said coating substantially comprising: a. from about 0.06 to 2 percent by weight of hydroxy propylmethyl cellulose, and b. from about 5 to 50 percent by weight of finely divided inorganic particles, and c. the remainder being water.
Claim 4
Dependent Claim
17 words
The coating composition as defined in claim 4, wherein said inorganic particles consist essentially of phosphor particles.
Claim 5
Dependent Claim
17 words
The coating composition as defined in claim 4, wherein said inorganic particles consist essentially of pigment particles.
References Cited (Backward Citations)
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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) | 1977-09-02 | 1978-03-04 | 1978-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-02 | 1982-03-04 | 1982-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-02 | 1986-03-04 | 1986-09-03 | $7700.00 | Window Closed / Lapsed |