Patent US2683992A successfully refreshed from Google Patents.
Patent US4055685A successfully refreshed from Google Patents.
US4055685A
Expired / Lapsed
US
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Process for the improvement of the adhesion of photographic layers to a film web by means of a corona treatment
Assignee: Agfa Gevaert AG
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Filing: 1976-04-26
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Granted: 1977-10-25
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Expires: 1996-04-26
Abstract
Abstract Corona treatment involves the continuous subjection of the film web to a steady alternating current discharge. This treatment is carried out in two consecutive stages, the corona discharge frequency f 1 in the first stage being in the range f 1 = 5 to 100 kHz and the corona discharge frequency f 2 in the second stage being in the range f 2 = 500 to 2000 kHz.
Inventors
- 👤 Gunther Bayer
- 👤 Hans Georg Fitzky
- 👤 Herbert Hoyer
- 👤 Gunter Luttgens
- 👤 Wolfgang Muller-Bardorff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:28
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/76; G03C1/91; G03C1/915; B; B29; B29C; B29C59/00; B29C59/10; H; H01; H01T; H01T19/00; B29C2791/00; B29C2791/001; B29K; B29K2023/00; B29K2023/04; B29K2023/06; B29K2711/00; B29K2711/12; B29K2711/123
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
58 words
A process for the corona treatment of a web of polyethylene coated photographic paper in which the web is subjected to alternating current corona discharge in two consecutive stages, the frequency of the corona discharge in the first stage being from 5 to 100 kHz and the frequency in the second stage being from 500 to 2000 kHz.
Claim 2
Dependent Claim
58 words
A process for the corona treatment of a web of polyethylene coated photographic paper in which the web is subjected to alternating current corona discharge in two consecutive stages, the frequency of the corona discharge in the first stage being from 5 to 100 kHz and the frequency in the second stage being from 500 to 2000 kHz.
Claim 3
Dependent Claim
32 words
A process according to claim 1, wherein the frequency in the first stage is from 40 to 60 kHz and the frequency in the second stage is from 1000 to 1500 kHz.
Claim 4
Dependent Claim
31 words
A process according to claim 1 wherein the discharge current intensities are from 1 to 10 mA per cm and the web travels at a speed of 0.5 to 1.5 m/sec.
Claim 5
Dependent Claim
31 words
A process according to claim 1 wherein the corona discharge in the first stage takes place in air and in the second stage in air or in a pure nitrogen atmosphere.
Claim 6
Dependent Claim
27 words
A process according to claim 1 wherein the polyethylene coate paper web is coated immediately after the two stage corona treatment with a photographic silver halide emulsion.
References Cited (Backward Citations)
US3031332A
Cited
US3549406A
Cited
US3582338A
Cited
US3702258A
Cited
US3697305A
Cited
USRE28628E
Cited
US3730753A
Cited
US3860427A
Cited
US4009037A
Cited
US3853585A
Cited
US3983301A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-10-24 | 1981-04-25 | 1981-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-24 | 1985-04-25 | 1985-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-24 | 1989-04-25 | 1989-10-25 | $7700.00 | Window Closed / Lapsed |