US5207948A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stir-in fluorescent lamp phosphor and method of making same
Assignee: Osram Sylvania Inc
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Filing: 1991-02-11
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Granted: 1993-05-04
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Expires: 2011-02-11
Abstract
Abstract A stir-in fluorescent lamp phosphor is coated with a 1:1 ratio of latex polymer and fumed silica. The polymer-coated fluorescent lamp phosphor exhibits improved dispersability and wettability in aqueous and organic binder media which are used to apply fluorescent lamp phosphors to the inside walls of a fluorescent lamp envelope.
Inventors
- 👤 Robert W. Wolfe
- 👤 Joseph J. Lenox
- 👤 Theodore J. Tomlinson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:00
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/02; C09K11/025; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2998
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
69 words
A method of making a stir-in magnesium tungstate phosphor, comprising the steps of: a) forming an aqueous slurry of said phosphor, a latex polymer and fumed silica; b) stirring said aqueous slurry to form a uniform dispersion of solid particles in an aqueous suspension; c) separating said solid particles from said aqueous suspension; and d) drying and screening said solid particles to form a stir-in polymer-coated magnesium tungstate phosphor.
Claim 2
Independent Claim
69 words
A method of making a stir-in magnesium tungstate phosphor, comprising the steps of: a) forming an aqueous slurry of said phosphor, a latex polymer and fumed silica; b) stirring said aqueous slurry to form a uniform dispersion of solid particles in an aqueous suspension; c) separating said solid particles from said aqueous suspension; and d) drying and screening said solid particles to form a stir-in polymer-coated magnesium tungstate phosphor.
Claim 3
Dependent Claim
25 words
The method of claim 1 wherein said latex polymer is selected from the group consisting of acrylic polymers, styrene/acrylic copolymers, and carboxylated acrylate acrylonitrile copolymers.
Claim 4
Dependent Claim
14 words
The method of claim 1 wherein said latex polymer is an acrylic latex polymer.
Claim 5
Dependent Claim
20 words
The method of claim 1 wherein said latex polymer comprises from 0.2 to 2.0 weight percent of said polymer-coated phosphor.
Claim 6
Dependent Claim
20 words
The method of claim 1 wherein said fumed silica comprises from 0.2 to 2.0 weight percent of said polymer-coated phosphor.
Claim 7
Dependent Claim
11 words
The method of claim 1 wherein said latex polymer is anionic.
Claim 8
Dependent Claim
22 words
The method of claim 1 wherein said solid particles are dried at 130° C. to 160° C. for at least one hour.
Claim 9
Dependent Claim
19 words
The method of claim 7 wherein said solid particles are dried at 140° C. for at least one hour.
Claim 10
Dependent Claim
55 words
A stir-in magnesium tungstate phosphor comprising magnesium tungstate phosphor coated with a 1:1 ratio of a latex polymer and fumed silica, said latex polymer and said fumed silica each comprising 0.5 weight percent of said phosphor, said latex polymer being selected from the group consisting of acrylic polymers, styrene/acrylic copolymers, and carboxylated acrylate acrylonitrile copolymers.
Claim 11
Dependent Claim
55 words
A stir-in magnesium tungstate phosphor comprising magnesium tungstate phosphor coated with a 1:1 ratio of a latex polymer and fumed silica, said latex polymer and said fumed silica each comprising 0.5 weight percent of said phosphor, said latex polymer being selected from the group consisting of acrylic polymers, styrene/acrylic copolymers, and carboxylated acrylate acrylonitrile copolymers.
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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) | 1996-05-03 | 1996-11-02 | 1997-05-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-05-03 | 2000-11-02 | 2001-05-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-05-03 | 2004-11-02 | 2005-05-04 | $7700.00 | Window Closed / Lapsed |