US4391903A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ionic copolymers in photographic light-sensitive silver halide films
Assignee: Agfa Gevaert NV
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Filing: 1982-02-08
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Granted: 1983-07-05
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Expires: 2002-02-08
Abstract
Abstract Ionic copolymers of styrene sulfonic acid and maleic acid improve covering power when added to the gelatin binder employed in medical silver halide X-ray emulsions.
Inventors
- 👤 Peter K. Sysak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 17:12
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/005; G03C1/04; G03C1/053
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
66 words
A photographic film comprising a silver halide emulsion layer superimposed on a support, characterized in that the binder component of the silver halide emulsion layer consists essentially of a major amount in parts by weight of gelatin and a minor amount in parts by weight of a poly(styrene sulfonic acid-co-maleic acid) salt of the formula: ##STR3## wherein M is an alkali metal, m=1-3, n=1, and x=5-50.
Claim 2
Dependent Claim
66 words
A photographic film comprising a silver halide emulsion layer superimposed on a support, characterized in that the binder component of the silver halide emulsion layer consists essentially of a major amount in parts by weight of gelatin and a minor amount in parts by weight of a poly(styrene sulfonic acid-co-maleic acid) salt of the formula: ##STR3## wherein M is an alkali metal, m=1-3, n=1, and x=5-50.
Claim 3
Dependent Claim
17 words
The photographic film of claim 1 wherein the silver halide emulsion layer is a medical X-ray emulsion.
Claim 4
Dependent Claim
29 words
The photographic film of claim 1 wherein 17-35% by weight of the gelatin in the silver halide emulsion layer has been replaced with the poly(styrene sulfonic acid-co-maleic acid) salt.
Claim 5
Dependent Claim
10 words
The photographic film of claim 1 wherein M=sodium and m=n=1.
Claim 6
Dependent Claim
11 words
The photographic film of claim 1 wherein M=sodium, m=3, and n=1.
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) | 1986-07-04 | 1987-01-03 | 1987-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-07-04 | 1991-01-03 | 1991-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-07-04 | 1995-01-03 | 1995-07-05 | $7700.00 | Window Closed / Lapsed |