US4508760A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for microencapsulation
Assignee: NOVA TRAN Corp A CORP OF WI
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Filing: 1983-06-10
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Granted: 1985-04-02
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Expires: 2003-06-10
Abstract
Abstract A method and apparatus for microencapsulating an electroluminescent phosphor with an extremely thin coating. The process involves vaporizing a poly-para-xylylene, pyrolyzing the resulting vapors to form reactive monomeric radicals, and then passing such vaporous radicals to a vacuum deposition zone where they contact tumbling particles of an electroluminescent phosphor under vacuum conditions. As the particles are being coated, they are sifted by means of a screen. The reactive monomeric radicals deposit on the tumbling particles, are adsorbed by the particles, and polymerized into a very thin coating on the surfaces of the particles.
Inventors
- 👤 Roger Olson
- 👤 Ronald J. Versic
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 17:17
CPC Classifications
B; B01; B01J; B01J13/00; B01J13/02; B01J13/06; B01J13/14; Y; Y10; Y10S; Y10S118/00; Y10S118/05
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
88 words
A method for microencapsulating an electroluminescent phosphor with an extremely thin coating which comprises: vaporizing a poly-para-xylylene, pyrolyzing the resulting vapors to form reactive monomeric radicals, passing said monomeric radicals to a vacuum deposition zone, tumbling particles of an electroluminescent phosphor in said deposition zone, sifting said particles during such tumbling to thereby maintain the original particle size distribution during deposition, and depositing said reactive monomeric radicals on said particles to cause said radicals to be adsorbed and polymerized into a coating on the surfaces of said particles.
Claim 2
Independent Claim
88 words
A method for microencapsulating an electroluminescent phosphor with an extremely thin coating which comprises: vaporizing a poly-para-xylylene, pyrolyzing the resulting vapors to form reactive monomeric radicals, passing said monomeric radicals to a vacuum deposition zone, tumbling particles of an electroluminescent phosphor in said deposition zone, sifting said particles during such tumbling to thereby maintain the original particle size distribution during deposition, and depositing said reactive monomeric radicals on said particles to cause said radicals to be adsorbed and polymerized into a coating on the surfaces of said particles.
Claim 3
Dependent Claim
12 words
A method according to claim 1 in which: said poly-para-xylylene is dichloro-dipara-xylylene.
Claim 4
Dependent Claim
14 words
A method according to claim 1 in which: said electroluminescent phosphor is zinc sulfide.
Claim 5
Dependent Claim
16 words
A method according to claim 1 in which: said coating is less than 0.1 micron thick.
Claim 6
Dependent Claim
17 words
A method according to claim 1 in which: said coating is about 0.01 to 0.06 micron thick.
Claim 7
Dependent Claim
21 words
A method according to claim 1 in which the phosphor articles have a mean diameter of from 5 to 50 microns.
Claim 8
Independent Claim
108 words
An apparatus for encapsulating particles of an electroluminescent phosphor which comprises: a vaporizing zone for vaporizing a poly-para-xylylene, a pyrolysis zone connected to said vaporizing zone, a rotary drum receiving reactive monomers formed in said pyrolysis zone, said rotary drum having discrete particles of said electroluminescent phosphor therein, a vacuum chamber surrounding said drum and communicating with the interior of said drum, a screen disposed within said drum to sift particles during rotation of said drum and tumbling of said particles, said screen having openings therein of a size arranged to maintain the original particle size distribution by the sifting action, and drive means for rotating said drum.
Claim 9
Independent Claim
108 words
An apparatus for encapsulating particles of an electroluminescent phosphor which comprises: a vaporizing zone for vaporizing a poly-para-xylylene, a pyrolysis zone connected to said vaporizing zone, a rotary drum receiving reactive monomers formed in said pyrolysis zone, said rotary drum having discrete particles of said electroluminescent phosphor therein, a vacuum chamber surrounding said drum and communicating with the interior of said drum, a screen disposed within said drum to sift particles during rotation of said drum and tumbling of said particles, said screen having openings therein of a size arranged to maintain the original particle size distribution by the sifting action, and drive means for rotating said drum.
Claim 10
Dependent Claim
18 words
An apparatus according to claim 7 in which: said screen is fastened to said drum and rotates therewith.
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) | 1988-04-01 | 1988-10-01 | 1989-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-04-01 | 1992-10-01 | 1993-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-04-01 | 1996-10-01 | 1997-04-02 | $7700.00 | Window Closed / Lapsed |