Patent US2827428A successfully refreshed from Google Patents.
US2827428A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photographic emulsion purification
Assignee: Veolia WTS Systems USA Inc
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Filing: 1955-03-21
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Granted: 1958-03-18
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Expires: 1975-03-21
Abstract
No abstract record available.
Inventors
- 👤 Joseph L Noble
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 20:02
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/005; G03C1/025; G03C2200/00; G03C2200/09
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
107 words
I N A METHOD OF PURIFYING A PHOTOGRAPHIC EMULSION COMPRISING AN AQUEOUS SUSPENSION OF GELATIN CONTAINING A PRECIPIATED PHOTOSENSITIVE SILVER HALIDE AND DISSOLVED IONIC IMPURITIES, THE STEPS COMPRISING PASSING SAID EMULSION INTO A FIRST ELECTROLYTIC CHAMBER BOUNDED ON EACH SIDE BY A SECOND AND THIRD ELECTROLYTIC CHAMBER RESPECTIVELY, SAID SECOND ELECTROLYTIC CHAMBER BEING SEPARATED FROM SAID FIRST ELECTROLYTIC CHAMBER BY A SELECTIVELY PERMEABLE CATION MEMBRANE AND SAID THIRD ELECTROLYTIC CHAMBER BEING SEPARATED FROM SAID FIRST ELECTROLYTIC CHAMBER BY A SELECTIVELY PERMEABLE ANION MEMBRANE, MEMBRANES COMPRISING ION EXCHANGE RESINS HAVING IONIC GROUPS CHEMICALLY BONDED THERETO WITH A DISSOCIATION CONSTANT OF AT LEAST 10**-5 AND BEING PRESENT IN AN
Claim 2
Dependent Claim
107 words
I N A METHOD OF PURIFYING A PHOTOGRAPHIC EMULSION COMPRISING AN AQUEOUS SUSPENSION OF GELATIN CONTAINING A PRECIPIATED PHOTOSENSITIVE SILVER HALIDE AND DISSOLVED IONIC IMPURITIES, THE STEPS COMPRISING PASSING SAID EMULSION INTO A FIRST ELECTROLYTIC CHAMBER BOUNDED ON EACH SIDE BY A SECOND AND THIRD ELECTROLYTIC CHAMBER RESPECTIVELY, SAID SECOND ELECTROLYTIC CHAMBER BEING SEPARATED FROM SAID FIRST ELECTROLYTIC CHAMBER BY A SELECTIVELY PERMEABLE CATION MEMBRANE AND SAID THIRD ELECTROLYTIC CHAMBER BEING SEPARATED FROM SAID FIRST ELECTROLYTIC CHAMBER BY A SELECTIVELY PERMEABLE ANION MEMBRANE, MEMBRANES COMPRISING ION EXCHANGE RESINS HAVING IONIC GROUPS CHEMICALLY BONDED THERETO WITH A DISSOCIATION CONSTANT OF AT LEAST 10**-5 AND BEING PRESENT IN AN
References Cited (Backward Citations)
US1801784A
Cited
US2694680A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-03-17 | 1961-09-16 | 1962-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-03-17 | 1965-09-16 | 1966-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-03-17 | 1969-09-16 | 1970-03-18 | $7700.00 | Window Closed / Lapsed |