Patent US4186007A successfully refreshed from Google Patents.
US4186007A
Expired / Lapsed
US
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Regeneration of spent color developers
Assignee: Agfa Gevaert AG
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Filing: 1978-04-17
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Granted: 1980-01-29
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Expires: 1998-04-17
Abstract
Abstract A new process for the regeneration of spent color developers using both an ion exchanger and certain adsorbents is described. This process preserves the capacity of the exchanger to be regenerated.
Inventors
- 👤 Heinz Meckl
- 👤 Karl Lohmer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:23
CPC Classifications
G; G03; G03C; G03C7/00; G03C7/30; G03C7/44
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
96 words
A process for the regeneration of a spent color developer solution which has been used for the color development of photographic materials containing at least one silver halide emulsion layer including the steps of first contacting a spent color developer solution containing bromide ions with an adsorbent selected from the group consisting of adsorption resins, active charcoal, surface-modified active charcoal, and Fuller's earths, and then contacting said spent color developer solution with an anion exchanger to remove bromide ions, and subsequently treating said anion exchanger to improve the bromide ion removable capability of said anion exchanger.
Claim 2
Dependent Claim
96 words
A process for the regeneration of a spent color developer solution which has been used for the color development of photographic materials containing at least one silver halide emulsion layer including the steps of first contacting a spent color developer solution containing bromide ions with an adsorbent selected from the group consisting of adsorption resins, active charcoal, surface-modified active charcoal, and Fuller's earths, and then contacting said spent color developer solution with an anion exchanger to remove bromide ions, and subsequently treating said anion exchanger to improve the bromide ion removable capability of said anion exchanger.
Claim 3
Dependent Claim
29 words
A process according to claim 1 wherein the colour developer solution is passed through a cation exchanger in addition to its treatment with the adsorbent and the anion exchanger.
Claim 4
Dependent Claim
23 words
A process according to claim 1 wherein the adsorption resins are phenol formaldehyde resins containing hydroxyl groups or secondary or tertiary amino groups.
Claim 5
Dependent Claim
16 words
A process according to claim 1 wherein the anion exchanger is a strongly basic anion exchanger.
Claim 6
Dependent Claim
25 words
A process according to claim 1 wherein the anion exchanger is a strongly basic anion exchanger and the adsorbent used is a phenol formaldehyde resin.
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) | 1983-01-28 | 1983-07-30 | 1984-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-01-28 | 1987-07-30 | 1988-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-01-28 | 1991-07-30 | 1992-01-29 | $7700.00 | Window Closed / Lapsed |