Patent US4429038A successfully refreshed from Google Patents.
US4429038A
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Process for concentrating yellow silver sols
Assignee: Agfa Gevaert AG
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Filing: 1982-07-26
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Granted: 1984-01-31
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Expires: 2002-07-26
Abstract
Abstract A yellow silver sol containing a binder is concentrated by flocculation in the presence of a calcium-free gelatin, a water-soluble chloride being added to the flocculation and/or after the redispersion.
Inventors
- 👤 Franz Moll
- 👤 Ingeborg Holl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 13:35
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/76; G03C1/825; G03C1/8255
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
70 words
A process for the production of a yellow silver sol prepared by reducing a water-soluble silver salt and precipitating the sol preparation and in the presence of a binder flocculating, washing and redispersing the preparation, wherein the improvement comprises in the presence of calcium-free gelatin flocculating and redispersing the sol, and adding to said sol preparation a water-soluble chloride selected from the group consisting of ammonium and alkali metal chlorides.
Claim 2
Dependent Claim
70 words
A process for the production of a yellow silver sol prepared by reducing a water-soluble silver salt and precipitating the sol preparation and in the presence of a binder flocculating, washing and redispersing the preparation, wherein the improvement comprises in the presence of calcium-free gelatin flocculating and redispersing the sol, and adding to said sol preparation a water-soluble chloride selected from the group consisting of ammonium and alkali metal chlorides.
Claim 3
Dependent Claim
32 words
A process according to claim 1, wherein the improvement comprises the calcium-free gelatine is added in a quantity of from 30 g to 300 g per mol of silver nitrate during flocculation.
Claim 4
Dependent Claim
33 words
A process as claimed in claim 1 in which said water-soluble chloride is added not subsequent to said flocculating in a concentration of from 0.05 to 0.7 mole per mol of silver sol.
Claim 5
Dependent Claim
37 words
A process as claimed in claim 1 in which said water-soluble chloride is added not prior to the redispersion in a concentration of from 10 -1 to 10 -2 mole of chloride per mol of silver sol.
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) | 1987-01-30 | 1987-08-01 | 1988-01-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-30 | 1991-08-01 | 1992-01-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-30 | 1995-08-01 | 1996-01-31 | $7700.00 | Window Closed / Lapsed |