US3717466A
Expired / Lapsed
US
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Fogged direct positive silver halide element containing a selenium compound sensitizer
Assignee: Agfa Gevaert NV
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Filing: 1971-02-18
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Granted: 1973-02-20
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Expires: 1991-02-18
Abstract
Abstract Direct-positive photographic elements are described which comprise uniformly fogged radiation-sensitive silver halide and a selenium compound of the formula : R - Se - Q wherein R is alkyl, aralkyl, alkaryl, aryl or a heterocyclic ring system and Q represents -Se-R'' or -S-R'' wherein R'' has one of the significances given for R, halogen, cyano, or WHEREIN EACH OF R1, R2 and R3 is alkyl, aralkyl or aryl and X is an anion but does not exist when R itself contains an anionic group. The selenium compounds increase the speed of the directpositive silver halide elements.
Inventors
- 👤 R Florens
- 👤 R Pollet
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:07
CPC Classifications
C; C07; C07D; C07D209/00; C07D209/02; C07D209/44; C07D209/48; C07C; C07C391/00; C07C391/02; C07D277/00; C07D277/60; C07D277/62; C07D277/64; C07F; C07F9/00; C07F9/02; C07F9/28; C07F9/54; C07F9/5463; G; G03; G03C; G03C1/00; G03C1/005; G03C1/485; G03C1/48515; G03C1/48523; Y; Y10; Y10S; Y10S430/00; Y10S430/15
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
118 words
A direct-positive photographic element comprising uniformly fogged radiation-sensitive silver halide and a selenium compound corresponding to the following formula: R - Se - Q wherein: R stands for an alkyl group, an aralkyl group, an alkaryl group, an aryl group or a heterocycle, Q stands for -Se-R'' or -S-R'' wherein R'' stands for an alkyl group, an aralkyl group, an alkaryl group, an aryl group or a heterocycle; halogen; -CN or wherein each of R1, R2 and R3 stands for alkyl, aralkyl or aryl and X stands for an anion but does not exist when R itself contains an anionic group, said selenium compound being present in an amount sufficient to increase the speed of said direct-positive element.
Claim 2
Dependent Claim
118 words
A direct-positive photographic element comprising uniformly fogged radiation-sensitive silver halide and a selenium compound corresponding to the following formula: R - Se - Q wherein: R stands for an alkyl group, an aralkyl group, an alkaryl group, an aryl group or a heterocycle, Q stands for -Se-R'' or -S-R'' wherein R'' stands for an alkyl group, an aralkyl group, an alkaryl group, an aryl group or a heterocycle; halogen; -CN or wherein each of R1, R2 and R3 stands for alkyl, aralkyl or aryl and X stands for an anion but does not exist when R itself contains an anionic group, said selenium compound being present in an amount sufficient to increase the speed of said direct-positive element.
Claim 3
Dependent Claim
31 words
A direct-positive photographic element according to claim 1, wherein the said selenium compound is present in an amount of from about 1 mg - 100 mg per mole of silver halide.
Claim 4
Dependent Claim
19 words
A direct-positive photographic element according to claim 1, wherein the silver halide has been uniformly fogged by chemical means.
Claim 5
Dependent Claim
21 words
A direct-positive photographic element according to claim 3, wherein the silver halide has been uniformly fogged by means of reducing agents.
Claim 6
Dependent Claim
40 words
A direct-positive photographic element according to claim 1, wherein the fogged silver halide emulsion comprises silver halide grains having an interior core of silver halide comprising centers promoting the deposition of photolytic silver and an outer shell of silver halide.
Claim 7
Dependent Claim
24 words
A direct-positive photographic element according to claim 5, wherein the said centers are formed by chemical sensitization of the interior core of silver halide.
Claim 8
Dependent Claim
30 words
A direct-positive photographic element according to claim 6, wherein said centers are formed by treatment of the interior core of silver halide with a reduction sensitizer and/or noble metal compound.
Claim 9
Dependent Claim
23 words
A direct-positive photographic element according to claim 7, wherein said centers are formed by treatment with a reduction sensitizer and a gold sensitizer.
Claim 10
Dependent Claim
43 words
A direct-positive photographic element according to claim 8, wherein fogging of the silver halide emulsion comprising silver halide grains having an interior core of chemically sensitized silver halide and an outer shell of silver halide, is effected by treatment with a reduction sensitizer.
Claim 11
Dependent Claim
35 words
A direct-positive element according to claim 9, wherein the reduction sensitizer used in the chemical sensitization of the silver halide core is the same as the reduction sensitizer used for fogging the silver halide emulsion.
Claim 12
Dependent Claim
14 words
A direct-positive element according to claim 10, wherein said reduction sensitizer is thiourea dioxide.
Claim 13
Dependent Claim
28 words
A direct-positive element according to claim 5, wherein the silver halide of the interior core as well as the silver halide of the outer shell is silver bromide.
Claim 14
Dependent Claim
13 words
A direct-positive photographic element according to claim 2, wherein said selenium compound is
Claim 15
Dependent Claim
13 words
A direct-positive photographic element according to claim 2, wherein said selenium compound is
Claim 16
Dependent Claim
13 words
A direct-positive photographic element according to claim 2, wherein said selenium compound is
Claim 17
Dependent Claim
13 words
A direct-positive photographic element according to claim 2, wherein said selenium compound is
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) | 1976-02-20 | 1976-08-21 | 1977-02-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-20 | 1980-08-21 | 1981-02-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-20 | 1984-08-21 | 1985-02-20 | $7700.00 | Window Closed / Lapsed |