US3772020A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Persulfate bleach-fix solution
Assignee: Eastman Kodak Co
•
Filing: 1971-11-19
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Granted: 1973-11-13
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Expires: 1991-11-19
Abstract
Abstract Bleach-fix solutions utilizing a water-soluble persulfate as the silver oxidizing agent and an alkyl amino alkyl thiol as the fixing agent are described.
Inventors
- 👤 E Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 01:02
CPC Classifications
G; G03; G03C; G03C7/00; G03C7/30; G03C7/42
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
41 words
A composition as claimed in claim 1 wherein the concentration of said bleaching agent is from about 0.05 to about 0.5 moles per liter and the concentration of said fixing agent is from about 0.1 to about 2.0 moles per liter.
Claim 2
Dependent Claim
41 words
A composition as claimed in claim 1 wherein the concentration of said bleaching agent is from about 0.1 to about 0.4 moles per liter and the concentration of said fixing agent is from about 0.13 to about 1.5 moles per liter.
Claim 3
Dependent Claim
25 words
A composition as claimed in claim 1 wherein said bleaching agent is selected from the group consisting of potassium persulfate, sodium persulfate and ammonim persulfate.
Claim 4
Dependent Claim
21 words
A composition as claimed in claim 1 wherein R1 and R2 are CH3 or C2H5 and n is 2 or 3.
Claim 5
Dependent Claim
20 words
A composition as claimed in claim 1 wherein said bleaching agent is potassium persulfate and said fixing agent is 2,2-diethylaminoethanethiol.
Claim 6
Dependent Claim
46 words
In a method of photographic processing wherein an exposed photographic element is treated with a bleach-fixing solution containing both a bleaching agent and a fixing agent, the improvement wherein said bleaching agent is a water-soluble persulfate and said fixing agent is a compound of the formula:
Claim 7
Dependent Claim
41 words
A method as claimed in claim 7 wherein the concentration of said bleaching agent is from about 0.05 to about 0.5 moles per liter and the concentration of said fixing agent is from about 0.1 to about 2.0 moles per liter.
Claim 8
Dependent Claim
41 words
A method as claimed in claim 7 wherein the concentration of said bleaching agent is from about 0.1 to about 0.4 moles per liter and the concentration of said fixing agent is from about 0.13 to about 1.5 moles per liter.
Claim 9
Dependent Claim
25 words
A method as claimed in claim 7 wherein said bleaching agent is selected from the group consisting of potassium persulfate, sodium persulfate and ammonium persulfate.
Claim 10
Dependent Claim
21 words
A method as claimed in claim 7 wherein R1 and R2 are CH3 or C2H5 and n is 2 or 3.
Claim 11
Dependent Claim
20 words
A method as claimed in claim 7 wherein said bleaching agent is potassium persulfate and said fixing agent is 2,2-diethylaminoethanethiol.
Claim 12
Independent Claim
33 words
A method of color processing an exposed photographic element comprising the steps of color development, stop-fixing, and bleach-fixinG in solution containing a water-soluble persulfate bleaching agent and a fixing agent of the formula:
Claim 13
Dependent Claim
41 words
A method as claimed in claim 13 wherein the concentration of said bleaching agent is from about 0.05 to about 0.5 moles per liter and the concentration of said fixing agent is from about 0.1 to about 2.0 moles per liter.
Claim 14
Dependent Claim
41 words
A method as claimed in claim 13 wherein the concentration of said bleaching agent is from about 0.1 to about 0.4 moles per liter and the concentration of said fixing agent is from about 0.13 to about 1.5 moles per liter.
Claim 15
Dependent Claim
25 words
A method as claimed in claim 13 wherein said bleaching agent is selected from the group consisting of potassium persulfate, sodium persulfate and ammonium persulfate.
Claim 16
Dependent Claim
21 words
A method as claimed in claim 13 wherein R1 and R2 are CH3 or C2H5 and n is 2 or 3.
Claim 17
Dependent Claim
20 words
A method as claimed in claim 13 wherein said bleaching agent is potassium persulfate and said fixing agent is 2,2-diethylaminoethanethiol.
References Cited (Backward Citations)
GB1131108A
Cited
US3434796A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-12 | 1977-05-14 | 1977-11-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-12 | 1981-05-14 | 1981-11-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-12 | 1985-05-14 | 1985-11-13 | $7700.00 | Window Closed / Lapsed |