Claims
- 1. A light-sensitive fogged direct positive silver halide emulsion containing a sensitizing amount of at least one cyanine dye selected from the formulae:
- wherein
- Y is an oxygen or sulfur atom,
- n is 2, 3, or 4,
- m is 1 or 2,
- R and R.sub.1 are independently halogen atoms,
- R.sub.2 is H or an alkyl group of 1 to 4 carbon atoms,
- R.sub.3 is selected from the group consisting of acylic hydrocarbon, alkyl-aryl, or aryl groups,
- R.sub.4 is H or alkyl of 1 to 3 carbon atoms,
- Z represents the non-metallic atoms required to complete a 5 or 6 membered desensitizing heterocyclic nucleus, and
- X is an acid anion.
- 2. The light-sensitive fogged direct positive silver halide emulsion of claim 1 containing a sensitizing amount of at least one dye of the formula: ##STR39## wherein: Y is an oxygen or sulfur atom,
- n is 2, 3, or 4,
- R and R.sub.1 independently represent a halogen atom,
- R.sub.2 is H or an alkyl group of 1 to 4 carbon atoms,
- R.sub.3 represents an acyclic hydrocarbon, alkyl-aryl, or aryl group,
- R.sub.4 is H or alkyl of 1 to 3 carbon atoms, and
- X represents an acid anion.
- 3. The emulsion of claim 2 wherein R and R.sub.1 are independently selected from the group consisting of Cl and Br and R.sub.3 is an alkyl group of 1 to 12 carbon atoms.
- 4. The emulsion of claim 3 wherein R and R.sub.1 are the same halogen and R.sub.3 is alkyl of 1 to 4 carbon atoms.
- 5. The light-sensitive fogged direct positive silver halide emulsion of claim 1 containing a sensitizing amount of at least one dye of the formula: ##STR40## wherein: m is 1 or 2,
- Z represents the C, S, O, Se, or N atoms necessary to complete a 5- or 6-membered desensitizing heterocyclic nucleus,
- Y is an oxygen or sulfur atom,
- n is 2, 3, or 4,
- R and R.sub.1 independently represent a halogen atom,
- R.sub.2 is H or an alkyl group of 1 to 4 carbon atoms,
- R.sub.3 represents an acyclic hydrocarbon, alkyl aryl, or aryl group, and
- X represents an acid anion.
- 6. A light-sensitive fogged direct positive silver halide emulsion containing a sensitizing amount of 3,3'-diethyl-5,7-5',7'-tetrabromo-oxacarbocyanine perchlorate.
- 7. A light-sensitive fogged direct positive silver halide emulsion containing a sensitizing amount of 3,3'-dimethyl-5,7-5',7'-tetrabromo-9-ethyl-oxacarbocyanine perchlorate.
- 8. A light-sensitive fogged direct positive silver halide emulsion containing a sensitizing amount of 3,3'-diethyl-5,7-5',7'-tetrachloro-6,6'-dimethyloxacarbocyanine ethylsulfate.
- 9. A light-sensitive fogged direct positive silver halide emulsion containing a sensitizing amount of 3,3'-diethyl-5,6-5',6'-tetrachloro-thiacarbocyanine bromide.
- 10. A light-sensitive fogged direct positive silver halide emulsion containing a sensitizing amount of 3,3'-diethyl-5,7-5',7'-tetrachloro-thiocarbocyanine iodide.
- 11. A light-sensitive fogged direct positive silver halide emulsion containing a sensitizing amount of 3,3',9-triethyl-5,7-5',7'-tetrachloro-thiocarbocyanine iodide.
- 12. The light-sensitive fogged direct positive silver halide emulsion of claim 1 also containing a color coupler.
- 13. A direct positive photographic element containing at least one layer of the light-sensitive emulsion of claim 1.
Priority Claims (1)
Number |
Date |
Country |
Kind |
50883 A/73 |
Jun 1973 |
IT |
|
CROSS-REFERENCE TO RELATED APPLICATION
This is a continuation-in-part of Ser. No. 478,616, filed June 12, 1974, now abandoned.
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
3338714 |
Ficken et al. |
Aug 1967 |
|
3772030 |
Gilman et al. |
Nov 1973 |
|
3822136 |
Sakazume et al. |
Jul 1974 |
|
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
478616 |
Jun 1974 |
|