Patent US2678885A successfully refreshed from Google Patents.
US2678885A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of photographic emulsions
Assignee: Eastman Kodak Co
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Filing: 1950-04-08
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Granted: 1954-05-18
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Expires: 1970-04-08
Abstract
No abstract record available.
Inventors
- 👤 Henry D Porter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:23
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/005; G03C1/015
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
96 words
THE METHOD OF MAKING A PHOTOGRAPHIC SILVER HALIDE EMULSION WHICH COMPRISES REACTING A CATION EXCHANGE MATERIAL CONTAINING SILVER IN THE CATION WITH AN AQUEOUS SOLUTION OF A WATERSOLUBLE HALIDE SELECTED FROM THE GROUP CONSISTING OF ALKALI METAL, ALKALINE EARTH METAL AND AMMONIUM HALIDE IN THE PRESENCE OF AN ORGANIC PEPTIZING AGENT FOR SILVER HALIDE, THEREBY EXCHANGING THE CATION OF THE HALIDE FOR SILVER AND FORMING A DISPERSION OF SILVER HALIDE IN AN AQUEOUS SOLUTION OF THE PEPTIZING AGENT WHICH DISPERSION IS SEPARABLE FROM THE SO-MODIFIED EXCHANGE MATERIAL, AND SEPARATING SAID DISPERSION FROM THE SO-MODIFIED EXCHANGE MATERIAL.
Claim 2
Independent Claim
96 words
THE METHOD OF MAKING A PHOTOGRAPHIC SILVER HALIDE EMULSION WHICH COMPRISES REACTING A CATION EXCHANGE MATERIAL CONTAINING SILVER IN THE CATION WITH AN AQUEOUS SOLUTION OF A WATERSOLUBLE HALIDE SELECTED FROM THE GROUP CONSISTING OF ALKALI METAL, ALKALINE EARTH METAL AND AMMONIUM HALIDE IN THE PRESENCE OF AN ORGANIC PEPTIZING AGENT FOR SILVER HALIDE, THEREBY EXCHANGING THE CATION OF THE HALIDE FOR SILVER AND FORMING A DISPERSION OF SILVER HALIDE IN AN AQUEOUS SOLUTION OF THE PEPTIZING AGENT WHICH DISPERSION IS SEPARABLE FROM THE SO-MODIFIED EXCHANGE MATERIAL, AND SEPARATING SAID DISPERSION FROM THE SO-MODIFIED EXCHANGE MATERIAL.
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) | 1957-05-17 | 1957-11-16 | 1958-05-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-05-17 | 1961-11-16 | 1962-05-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-05-17 | 1965-11-16 | 1966-05-18 | $7700.00 | Window Closed / Lapsed |