Patent US4332329A successfully refreshed from Google Patents.
US4332329A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Implosion coatings
Assignee: PPG Industries Inc
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Filing: 1977-10-25
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Granted: 1982-06-01
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Expires: 1997-10-25
Abstract
Abstract An implosion-protected evacuated glass enclosure such as a cathode ray tube or an electric lamp is disclosed. The enclosure is made implosion resistant by depositing on the exterior surface thereof a polyurethane film. The mechanical properties of the polyurethane film result in outstanding glass retention properties when the evacuated glass enclosure implodes.
Inventors
- 👤 Roger L. Scriven
- 👤 Wen-Hsuan Chang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 22:22
CPC Classifications
H; H01; H01J; H01J61/00; H01J61/02; H01J61/30; H01J61/35; H01J29/00; H01J29/86; H01J29/87; H01J2229/00; H01J2229/87; H01J2229/875; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31551; Y10T428/31598; Y10T428/31601
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
152 words
An implosion protected evacuated glass enclosure which comprises in combination: (A) a sealed evacuated glass enclosure having exterior and interior surfaces, through at least a portion of said surfaces light is transmitted; and (B) a transparent, non-tacky, scratch-resistant, polyurethane film on the exposed exterior surface of said glass enclosure having a low degree of adhesion to the exterior surface of said sealed evacuated glass enclosure, said low degree of adhesion being such that said polyurethane film adheres to said glass surface with a 90° peel strength of less than about 20 pounds per lineal inch and the mechanical properties of the polyurethane film are such that when a free film of approximately 1 to 2.5 mils is subjected to tensile testing according to ASTM D-638-72, the film exhibits a tensile strength of from about 1000 to 15,000 pounds per square inch and a corresponding elongation of from about 150 to 1500 percent.
Claim 2
Dependent Claim
152 words
An implosion protected evacuated glass enclosure which comprises in combination: (A) a sealed evacuated glass enclosure having exterior and interior surfaces, through at least a portion of said surfaces light is transmitted; and (B) a transparent, non-tacky, scratch-resistant, polyurethane film on the exposed exterior surface of said glass enclosure having a low degree of adhesion to the exterior surface of said sealed evacuated glass enclosure, said low degree of adhesion being such that said polyurethane film adheres to said glass surface with a 90° peel strength of less than about 20 pounds per lineal inch and the mechanical properties of the polyurethane film are such that when a free film of approximately 1 to 2.5 mils is subjected to tensile testing according to ASTM D-638-72, the film exhibits a tensile strength of from about 1000 to 15,000 pounds per square inch and a corresponding elongation of from about 150 to 1500 percent.
Claim 3
Dependent Claim
14 words
The glass enclosure of claim 1 in the form of a cathode ray tube.
Claim 4
Dependent Claim
13 words
The glass enclosure of claim 2 in the form of a television tube.
Claim 5
Dependent Claim
13 words
The glass enclosure of claim 1 in the form of an electric lamp.
Claim 6
Dependent Claim
13 words
The glass enclosure of claim 4 in the form of a fluorescent lamp.
Claim 7
Dependent Claim
14 words
The glass enclosure of claim 1 in which the polyurethane is a thermoplastic polyurethane.
Claim 8
Dependent Claim
16 words
The glass enclosure of claim 1 in which the polyurethane is a poly(ester-urethane) or a poly(ether-urethane).
Claim 9
Dependent Claim
14 words
The glass enclosure of claim 1 in which the polyurethane is a thermosetting polyurethane.
Claim 10
Dependent Claim
21 words
The glass enclosure of claim 1 in which the polyurethane film has a thickness of from about 0.2 to 20 mils.
Claim 11
Dependent Claim
20 words
The glass enclosure of claim 1 in which the polyurethane film is deposited from an aqueous dispersion of a polyurethane.
Claim 12
Dependent Claim
28 words
The glass enclosure of claim 1 in which the polyurethane contains an adhesion control agent selected from the class consisting of adhesion inhibitors, adhesion promoters and mixture thereof.
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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) | 1985-05-31 | 1985-11-30 | 1986-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-05-31 | 1989-11-30 | 1990-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-05-31 | 1993-11-30 | 1994-06-01 | $7700.00 | Window Closed / Lapsed |