Claims
- 1. A method for enhancing and darkening the silver image density of a radiograph, which comprises contacting an underexposed, developed and fixed radiographic silver halide film with a composition to initially intensify the image density profile of the radiograph, said composition comprising an aqueous mixture of at least one water soluble organic or inorganic salt of copper, a water soluble ferricyanide salt and a sequestering agent having a stability constant of sufficient value to prevent substantial precipitation of cupric ferricyanide in said composition and to enable formation of a cupric ferrocyanide-containing composition in said radiographic film and subsequently darkening said enhanced silver image by contacting said treated radiograph with an aqueous solution of an iron salt.
- 2. The method of claim 1 wherein iron is present in the darkening solution in the range of between about 0.01 percent and about the solubility limit of the iron salt in solution.
- 3. The method of claim 1 wherein iron is present in the darkening solution in an amount between about 0.01 and about 10.0 percent by weight.
- 4. The method of claim 1 wherein the iron salt is inorganic.
- 5. The method of claim 1 wherein the iron salt is selected from the group consisting of ferrous and ferric salts of sulfate, nitrate, perchlorate, thiocyanate, formate, fluoride, chloride, bromide, 2-ethylhexanoate and mixtures thereof.
- 6. The method of claim 1 wherein the iron salt is the ferrous or ferric salt of sulfate or chloride.
- 7. The method of claim 1 wherein the iron salt is ferrous sulfate.
- 8. The method of claim 1 wherein the iron salt is ferric chloride.
- 9. A method for reducing the potential harmful effects of radiation resulting from radiographic diagnosis, which method comprises underexposing a radiographic silver halide film to radiation, developing and fixing the underexposed film and contacting the developed and fixed film with a composition to initially intensify the silver image density profile of the radiograph, said composition comprising an aqueous mixture of at least one water soluble organic or inorganic salt of copper, a water soluble ferricyanide salt and a sequestering agent having a stability constant of sufficient value to prevent substantial precipitation of cupric ferricyanide in said composition and to enable formation of a cupric ferrocyanide-containing composition in said radiographic film and subsequently darkening said enhanced silver image by contacting said treated radiograph with an aqueous solution of an iron salt.
- 10. The method of claim 9 wherein iron is present in the darkening solution in the range of between about 0.01 percent and about the solubility limit of the iron salt in solution.
- 11. The method of claim 9 wherein iron is present in the darkening solution in an amount between about 0.01 and about 10.0 percent by weight.
- 12. The method of claim 9 wherein the iron salt is inorganic.
- 13. The method of claim 9 wherein the iron salt is selected from the group consisting of ferrous and ferric salts of sulfate, nitrate, perchlorate, thiocyanate, formate, fluoride, chloride, bromide, 2-ethylhexanoate and mixtures thereof.
- 14. The method of claim 9 wherein the iron salt is the ferrous or ferric salt of sulfate or chloride.
- 15. The method of claim 9 wherein the iron salt is ferrous sulfate.
- 16. The method of claim 9 wherein the iron salt is ferric chloride.
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of application Ser. No. 971,922, field Dec. 21, 1978, now U.S. Pat. No. 4,238,563 which, in turn, was a continuation-in-part of application Ser. No. 848,993, filed Nov. 11, 1977, and is now abandoned.
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
2699994 |
Umberger |
Jan 1955 |
|
3083097 |
Lassig et al. |
Mar 1963 |
|
3753714 |
Sugiyama et al. |
Aug 1973 |
|
Non-Patent Literature Citations (5)
Entry |
British Journal of Photography, Jun. 1916, vol. 63, pp. 357-358. |
Amateur Photographer & Photography, Jun. 1923, pp. 567-568. |
Photo Technique, Oct. 1940, pp. 42-46. |
British Journal of Photography, Aug. 1955, pp. 376-377. |
Neblette: Photography 1952, pp. 351-363. |
Continuation in Parts (2)
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Number |
Date |
Country |
Parent |
971922 |
Dec 1978 |
|
Parent |
848993 |
Nov 1977 |
|