Patent US4287229A successfully refreshed from Google Patents.
US4287229A
Expired / Lapsed
US
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Method for surface treatment of phosphor particles
Assignee: Toshiba Corp
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Filing: 1979-11-05
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Granted: 1981-09-01
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Expires: 1999-11-05
Abstract
Abstract Disclosed is a method for surface treatment of phosphor particles which comprises forming a continuous film of silicon dioxide on the surface of each phosphor particle by treating the phosphor particle with a solution containing an aqueous solution of organic alkali and silicon dioxide dissolved therein.
Inventors
- 👤 Minoru Watanabe
- 👤 Mitsuhiro Oikawa
- 👤 Toshio Nishimura
- 👤 Masao Asada
- 👤 Masao Tezuka
- 👤 Tsurahide Cho
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 06:37
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/02; C09K11/025; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2993
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
48 words
A method for surface treatment of phosphor particles consisting essentially of forming a continuous film of silicon dioxide on the surface of each phosphor particle by treating said phosphor particle with a solution containing an aqueous solution of organic alkali and silicon dioxide dissolved in said aqueous solution.
Claim 2
Independent Claim
48 words
A method for surface treatment of phosphor particles consisting essentially of forming a continuous film of silicon dioxide on the surface of each phosphor particle by treating said phosphor particle with a solution containing an aqueous solution of organic alkali and silicon dioxide dissolved in said aqueous solution.
Claim 3
Dependent Claim
37 words
A method according to claim 1 or 3, wherein said organic alkali is a member selected from the group consisting of choline, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, tributylmonoethylammonium hydroxide, trimethylmonooctylammonium hydroxide, and triethylmonophenylammonium hydroxide.
Claim 4
Independent Claim
80 words
A method of forming of thin continuous silicon dioxide film on the surface of a phosphor consisting essentially of the steps of: (a) dissolving silicon dioxide in an organic alkali solution to form a silicon dioxide-containing solution; (b) adding the silicon dioxide-containing solution of step (a) to phosphor particles thereby depositing solid silicon dioxide on the surfaces of said phosphors to form a thin continuous silicon dioxide film thereon, and thereafter (c) drying the resulting continuous silicon dioxide film-coated particles.
Claim 5
Independent Claim
80 words
A method of forming of thin continuous silicon dioxide film on the surface of a phosphor consisting essentially of the steps of: (a) dissolving silicon dioxide in an organic alkali solution to form a silicon dioxide-containing solution; (b) adding the silicon dioxide-containing solution of step (a) to phosphor particles thereby depositing solid silicon dioxide on the surfaces of said phosphors to form a thin continuous silicon dioxide film thereon, and thereafter (c) drying the resulting continuous silicon dioxide film-coated particles.
Claim 6
Dependent Claim
27 words
A method according to claim 1 or 3 wherein the resulting coating amounts to from 0.02 to 4% by weight of the weight of the phosphor particles.
Claim 7
Dependent Claim
23 words
A method according to claim 1 or 3 wherein the continuous silicon dioxide film has a thickness of from 0.5 to 70 mμ.
Claim 8
Dependent Claim
21 words
A method according to claim 5 wherein the continuous silicon dioxide film has a thickness of from 1 to 40 mμ.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-08-31 | 1985-03-02 | 1985-09-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-08-31 | 1989-03-02 | 1989-09-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-08-31 | 1993-03-02 | 1993-09-01 | $7700.00 | Window Closed / Lapsed |