US2950972A - Photographic emulsions having increased sensitivity to x-ray and gamma ray radiation - Google Patents
Photographic emulsions having increased sensitivity to x-ray and gamma ray radiation Download PDFInfo
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- US2950972A US2950972A US471106A US47110654A US2950972A US 2950972 A US2950972 A US 2950972A US 471106 A US471106 A US 471106A US 47110654 A US47110654 A US 47110654A US 2950972 A US2950972 A US 2950972A
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- cadmium
- emulsion
- silver
- ray
- bromide
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- 239000000839 emulsion Substances 0.000 title claims description 50
- 230000035945 sensitivity Effects 0.000 title claims description 15
- 230000005251 gamma ray Effects 0.000 title description 6
- 230000005855 radiation Effects 0.000 title description 5
- 238000000034 method Methods 0.000 claims description 26
- 230000008569 process Effects 0.000 claims description 22
- BDOSMKKIYDKNTQ-UHFFFAOYSA-N cadmium atom Chemical class [Cd] BDOSMKKIYDKNTQ-UHFFFAOYSA-N 0.000 claims description 16
- 229910052709 silver Inorganic materials 0.000 claims description 14
- 239000004332 silver Substances 0.000 claims description 14
- SQGYOTSLMSWVJD-UHFFFAOYSA-N silver(1+) nitrate Chemical compound [Ag+].[O-]N(=O)=O SQGYOTSLMSWVJD-UHFFFAOYSA-N 0.000 claims description 14
- -1 SILVER HALIDE Chemical class 0.000 claims description 13
- YKYOUMDCQGMQQO-UHFFFAOYSA-L cadmium dichloride Chemical compound Cl[Cd]Cl YKYOUMDCQGMQQO-UHFFFAOYSA-L 0.000 claims description 10
- WLZRMCYVCSSEQC-UHFFFAOYSA-N cadmium(2+) Chemical compound [Cd+2] WLZRMCYVCSSEQC-UHFFFAOYSA-N 0.000 claims description 10
- 239000012876 carrier material Substances 0.000 claims description 10
- ADZWSOLPGZMUMY-UHFFFAOYSA-M silver bromide Chemical compound [Ag]Br ADZWSOLPGZMUMY-UHFFFAOYSA-M 0.000 claims description 9
- KPWJBEFBFLRCLH-UHFFFAOYSA-L cadmium bromide Chemical compound Br[Cd]Br KPWJBEFBFLRCLH-UHFFFAOYSA-L 0.000 claims description 8
- 229910001961 silver nitrate Inorganic materials 0.000 claims description 7
- XIEPJMXMMWZAAV-UHFFFAOYSA-N cadmium nitrate Inorganic materials [Cd+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O XIEPJMXMMWZAAV-UHFFFAOYSA-N 0.000 claims description 6
- 230000006872 improvement Effects 0.000 claims description 6
- NMHMNPHRMNGLLB-UHFFFAOYSA-N phloretic acid Chemical compound OC(=O)CCC1=CC=C(O)C=C1 NMHMNPHRMNGLLB-UHFFFAOYSA-N 0.000 claims description 6
- FOIXSVOLVBLSDH-UHFFFAOYSA-N Silver ion Chemical compound [Ag+] FOIXSVOLVBLSDH-UHFFFAOYSA-N 0.000 claims description 4
- LHQLJMJLROMYRN-UHFFFAOYSA-L cadmium acetate Chemical compound [Cd+2].CC([O-])=O.CC([O-])=O LHQLJMJLROMYRN-UHFFFAOYSA-L 0.000 claims description 4
- 238000002156 mixing Methods 0.000 claims description 4
- 229910001508 alkali metal halide Inorganic materials 0.000 claims description 3
- 150000008045 alkali metal halides Chemical class 0.000 claims description 3
- 238000002360 preparation method Methods 0.000 claims description 3
- 239000006185 dispersion Substances 0.000 claims description 2
- 229910052793 cadmium Inorganic materials 0.000 description 14
- 150000001661 cadmium Chemical class 0.000 description 11
- CPELXLSAUQHCOX-UHFFFAOYSA-M Bromide Chemical compound [Br-] CPELXLSAUQHCOX-UHFFFAOYSA-M 0.000 description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 9
- 108010010803 Gelatin Proteins 0.000 description 6
- 229920000159 gelatin Polymers 0.000 description 6
- 239000008273 gelatin Substances 0.000 description 6
- 235000019322 gelatine Nutrition 0.000 description 6
- 235000011852 gelatine desserts Nutrition 0.000 description 6
- 239000000463 material Substances 0.000 description 6
- 239000004372 Polyvinyl alcohol Substances 0.000 description 5
- 229920002451 polyvinyl alcohol Polymers 0.000 description 5
- 238000013019 agitation Methods 0.000 description 4
- 239000003513 alkali Substances 0.000 description 4
- 239000002585 base Substances 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 239000001397 quillaja saponaria molina bark Substances 0.000 description 3
- 229930182490 saponin Natural products 0.000 description 3
- 150000007949 saponins Chemical class 0.000 description 3
- PAYRUJLWNCNPSJ-UHFFFAOYSA-N Aniline Chemical compound NC1=CC=CC=C1 PAYRUJLWNCNPSJ-UHFFFAOYSA-N 0.000 description 2
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 229940006460 bromide ion Drugs 0.000 description 2
- 229920002678 cellulose Polymers 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 238000000502 dialysis Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000004848 polyfunctional curative Substances 0.000 description 2
- IOLCXVTUBQKXJR-UHFFFAOYSA-M potassium bromide Chemical compound [K+].[Br-] IOLCXVTUBQKXJR-UHFFFAOYSA-M 0.000 description 2
- FGIUAXJPYTZDNR-UHFFFAOYSA-N potassium nitrate Chemical compound [K+].[O-][N+]([O-])=O FGIUAXJPYTZDNR-UHFFFAOYSA-N 0.000 description 2
- 125000002924 primary amino group Chemical group [H]N([H])* 0.000 description 2
- 238000002601 radiography Methods 0.000 description 2
- 229910052705 radium Inorganic materials 0.000 description 2
- HCWPIIXVSYCSAN-UHFFFAOYSA-N radium atom Chemical compound [Ra] HCWPIIXVSYCSAN-UHFFFAOYSA-N 0.000 description 2
- 150000003839 salts Chemical class 0.000 description 2
- 239000004094 surface-active agent Substances 0.000 description 2
- ZTFYJIXFKGPCHV-UHFFFAOYSA-N 2-propan-2-ylnaphthalene-1-sulfonic acid Chemical compound C1=CC=CC2=C(S(O)(=O)=O)C(C(C)C)=CC=C21 ZTFYJIXFKGPCHV-UHFFFAOYSA-N 0.000 description 1
- QTBSBXVTEAMEQO-UHFFFAOYSA-M Acetate Chemical compound CC([O-])=O QTBSBXVTEAMEQO-UHFFFAOYSA-M 0.000 description 1
- 239000004354 Hydroxyethyl cellulose Substances 0.000 description 1
- 229920000663 Hydroxyethyl cellulose Polymers 0.000 description 1
- 239000004952 Polyamide Substances 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- BFNBIHQBYMNNAN-UHFFFAOYSA-N ammonium sulfate Chemical compound N.N.OS(O)(=O)=O BFNBIHQBYMNNAN-UHFFFAOYSA-N 0.000 description 1
- 229910052921 ammonium sulfate Inorganic materials 0.000 description 1
- 235000011130 ammonium sulphate Nutrition 0.000 description 1
- 150000001450 anions Chemical class 0.000 description 1
- CODNYICXDISAEA-UHFFFAOYSA-N bromine monochloride Chemical compound BrCl CODNYICXDISAEA-UHFFFAOYSA-N 0.000 description 1
- 239000001913 cellulose Substances 0.000 description 1
- 229920002301 cellulose acetate Polymers 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000004945 emulsification Methods 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- 235000019447 hydroxyethyl cellulose Nutrition 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 150000002895 organic esters Chemical class 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 229920002647 polyamide Polymers 0.000 description 1
- 229920002689 polyvinyl acetate Polymers 0.000 description 1
- 239000011118 polyvinyl acetate Substances 0.000 description 1
- 239000004323 potassium nitrate Substances 0.000 description 1
- 235000010333 potassium nitrate Nutrition 0.000 description 1
- 230000001376 precipitating effect Effects 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 230000005070 ripening Effects 0.000 description 1
- 230000001235 sensitizing effect Effects 0.000 description 1
- ZUNKMNLKJXRCDM-UHFFFAOYSA-N silver bromoiodide Chemical compound [Ag].IBr ZUNKMNLKJXRCDM-UHFFFAOYSA-N 0.000 description 1
- 230000007480 spreading Effects 0.000 description 1
- 238000003892 spreading Methods 0.000 description 1
- 239000000080 wetting agent Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
- G03C1/00—Photosensitive materials
- G03C1/005—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein
- G03C1/06—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein with non-macromolecular additives
- G03C1/08—Sensitivity-increasing substances
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
- G03C5/00—Photographic processes or agents therefor; Regeneration of such processing agents
- G03C5/16—X-ray, infrared, or ultraviolet ray processes
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S430/00—Radiation imagery chemistry: process, composition, or product thereof
- Y10S430/167—X-ray
Definitions
- This invention relates to the improvement of photographic materials, and more particularly to the production of silver halide photographic emulsions of increased sensitivity to X-rays.
- Cadmium salts have been used in the manufacture of photographic emulsions for recording the effects of visible light. For example, ammonia-type and neutral boil-type celerated by the use of cadmium.
- Cadmium salts were also used in gelatino silver halide emulsions to accelerate ripening and to increase the contrast for exposure to light.
- the activation produced by cadmium was greatest for chlorobromide emulsions containing from 25% to 30% bromide, but could no longer be observed when the bromide content Was lowered below or raised to 50%.
- the amounts of cadmium ion used range from about 0.001 to 0.2 mol percent relative to the amount of silver used. Expressed in terms ofparts per million, the amounts of cadmium ion used range from about 10 parts to about 2000 parts per million parts ofsilver ion.
- the concentration of cadmium based on the silver bromide content of the emulsion ranges from 0.007 to 1.4 milligrams of cadmium per gram of silver bromide.
- the cadmium When used in the small concentrations specified above, the cadmium produces a marked decrease in the sensitivity to visible light, although this sensitivity loss depends somewhat on the details of the emulsion formulation and the intensity level of the visible light to which the ex- Patented Aug. 30, 1960 7 can be introduced in the presence of a colloidal carrier as a water soluble salt of cadmium such as cadmium chloride or cadmium bromide mixed with the alkali bromide solution to which is added the silver nitrate solution to produce the formation of crystals or grains which consist primarily of silver bromide.
- a colloidal carrier as a water soluble salt of cadmium such as cadmium chloride or cadmium bromide mixed with the alkali bromide solution to which is added the silver nitrate solution to produce the formation of crystals or grains which consist primarily of silver bromide.
- a water soluble cadmium salt such as cadmium nitrate or acetate can be mixed with the silver nitrate solution which is then added to the alkali bromide solution during the emulsification step.
- wihch is used to introduce the cadmium ion, an increase in X-ray and gamma ray sensitivity is obtained, proving that the observed increase in sensitivity is a result of the addition of the cadmium ion and is not due to the particular anion used.
- the cadmium ion is built into the host silver halide lattice as an impurity occupying lattice sites throughout the crystal normally occupied by silver ion, resulting in a distortion of the normal lattice structure and .thereby altering the sensitivity to X rays and gamma rays.
- the two solutions were first heated separately to a temperature of 68 C. and then mixed by the addition of Solution 2 to Solution l at a slow rate over a period of 1 hour, with constant agitation. Thereafter, 60 grams of dry gelatin were added and the mixture was maintained at 68C. for 20 minutes, with agitation. The emulsion was then chilled, shredded, and washed until the bromide ion concentration was milligrams per kilogram of liquid emulsion. The emulsion was remelted and then after-ripened for 20 minutes at 60 C. Saponin was added as a spreading agent, formaldehyde was added as a hardener, and the emulsion coated onto a cellulose ester film base.
- the speed of this emulsion was determined for a series of exposures to X-rays generated at 10 kilovolts, 65 kilovolts, 250 kilovolts and for exposure to the gamma rays of radium.
- the emulsion containing cadmium was found to be more than 50% faster than the emulsion containing no cadmium.
- the two solutions were first heated separately to a temperature of 50 C. and then mixed by adding Solution 2 to Solution 1 at a rate which allowed completion of addition within 1 minute.
- the emulsion obtained was digested for minutes at 50 C., poured into a parchment bag and dialysed at C. in order to remove the potassium nitrate.
- 100 mls. of water and a small amount of saponin were added and the emulsion coated onto a fdm base which was especially subbed for polyvinyl alcohol coatings.
- the X-ray and gamma ray speed of this very fine grain emulsion was about 50% higher than the speed of a type which had been prepared in an identical manner except that it did not contain any cadmium ions.
- Example 111 Example H was repeated with the exception that the purification by dialysis was replaced by precipitation with ammonium sulfate, and that the precipitated particles were washed with water and remelted prior to coating.
- Example IV An X-ray emulsion was made according to the following procedure.
- the speed of this emulsion was determined for a series of exposures to X-rays generated at 10 kilovolts, 65 kilovolts, 250 kilovolts, and for exposure to the gamma rays of radium.
- the emulsion containing cadmium was found to be about 50% faster than the emulsion containing no cadmium.
- silver bromo-iodide emulsions can be used in place of the silver bromide emulsions illustrated in the examples and it is to be understood that the term silver bromide as used in the appended claims is intended to embrace silver bromide emulsions in which from to of the weight of the silver halide is silver bromide.
- colloidal carrier materials can be used such as water dispersible organic esters of cellulose, polyamides, hydroxyethyl cellulose, modified polyvinyl alcohol or partially hydrolyzed polyvinyl acetate. Special sensitizing agents which are known to the art can be added to the emulsions to increase their inherent speed.
- synthetic surfactants or wetting agents such as isopropylnaphthalene sulfonic acid can be used which aid in the preparation of even coatings without bubble formation.
- Color formers fast to diffusion and capable of forming, upon development with a primary amino developer, azometmne and quinonimine dye images, can be added to the emulsion in which case dye images are obtained upon color development with such primary amino developer.
- a process of preparing a photographic silver bromide emulsion which includes mixing a silver nitrate solution with an alkali bromide solution containing a colloidal carrier material, the improvement which comprises adding to at least one of said solutions prior to mixing a water soluble carmium salt selected from the group consisting of cadmium chloride, cadmium bromide, cadmium nitrate and cadmium acetate in a concentration ranging from 0.001 to 0.2 mole percent of cadmium ion per mol of silver ion, thereby increasing the sensitivity of said emulsion to X-ray and gamma ray radiation.
- colloidal carrier material is polyvinyl alcohol.
- colloidal carrier material is polyvinyl alcohol.
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- Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- General Physics & Mathematics (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Silver Salt Photography Or Processing Solution Therefor (AREA)
- Saccharide Compounds (AREA)
- Colloid Chemistry (AREA)
Description
PHOTGGRAPHIC EMULSIONS HAVING IN- CREASED SENSITIVITY TO X-RAY AND GAMIMA RAY RADIATION Fritz W. H. Mueller and Ernest T. Larson, Jr., Binghamton, N.Y., assignors to General Aniline & Film Corporation, New York, N.Y., a corporation of Delaware No Drawing. Filed Nov. 24, 1954, Ser. No. 471,106
19 Claims. (Cl. 96-108) This invention relates to the improvement of photographic materials, and more particularly to the production of silver halide photographic emulsions of increased sensitivity to X-rays.
Cadmium salts have been used in the manufacture of photographic emulsions for recording the effects of visible light. For example, ammonia-type and neutral boil-type celerated by the use of cadmium.
Cadmium salts were also used in gelatino silver halide emulsions to accelerate ripening and to increase the contrast for exposure to light. The activation produced by cadmium was greatest for chlorobromide emulsions containing from 25% to 30% bromide, but could no longer be observed when the bromide content Was lowered below or raised to 50%.
The prior art dealing with the use of cadmium salts in silver halide emulsions pertained exclusively to the improvement of photographic properties for exposures to light. No improvement in the sensitivity to X-rays and gamma rays was reported by the early investigators.
It is an object of this invention to increase the sensitivity of photographic emulsions to X-rays and gamma rays as used in the practice of X-ray diifraction, medical radiography, industrial radiography, detection of nuclear radiation, and similar applications.
Other objects will be apparent from the following description.
We have discovered that the addition of very small amounts of cadmium ion to the solutions used in precipitating a silver halide emulsion has the effect of increasing the X-ray and gamma ray sensitivity of the finished emulsion. The amounts of cadmium ion used range from about 0.001 to 0.2 mol percent relative to the amount of silver used. Expressed in terms ofparts per million, the amounts of cadmium ion used range from about 10 parts to about 2000 parts per million parts ofsilver ion. The concentration of cadmium based on the silver bromide content of the emulsion ranges from 0.007 to 1.4 milligrams of cadmium per gram of silver bromide. When used in the small concentrations specified above, the cadmium produces a marked decrease in the sensitivity to visible light, although this sensitivity loss depends somewhat on the details of the emulsion formulation and the intensity level of the visible light to which the ex- Patented Aug. 30, 1960 7 can be introduced in the presence of a colloidal carrier as a water soluble salt of cadmium such as cadmium chloride or cadmium bromide mixed with the alkali bromide solution to which is added the silver nitrate solution to produce the formation of crystals or grains which consist primarily of silver bromide. Except for the halide salts, a water soluble cadmium salt such as cadmium nitrate or acetate can be mixed with the silver nitrate solution which is then added to the alkali bromide solution during the emulsification step. Irrespective of the procedure wihch is used to introduce the cadmium ion, an increase in X-ray and gamma ray sensitivity is obtained, proving that the observed increase in sensitivity is a result of the addition of the cadmium ion and is not due to the particular anion used.
Without wishing to be bound by or limited to any particular theory of the mechanism involved in producing increased X-ray sensitivity, it is believed that the cadmium ion is built into the host silver halide lattice as an impurity occupying lattice sites throughout the crystal normally occupied by silver ion, resulting in a distortion of the normal lattice structure and .thereby altering the sensitivity to X rays and gamma rays.
The following examples serve to illustrate the invention, but it. is to be understood that the invention is not to be restricted thereto.
The two solutions were first heated separately to a temperature of 68 C. and then mixed by the addition of Solution 2 to Solution l at a slow rate over a period of 1 hour, with constant agitation. Thereafter, 60 grams of dry gelatin were added and the mixture was maintained at 68C. for 20 minutes, with agitation. The emulsion was then chilled, shredded, and washed until the bromide ion concentration was milligrams per kilogram of liquid emulsion. The emulsion was remelted and then after-ripened for 20 minutes at 60 C. Saponin was added as a spreading agent, formaldehyde was added as a hardener, and the emulsion coated onto a cellulose ester film base.
The speed of this emulsion, measured as th reciprocal of the exposure required to produce a density of 0.5 above base and fog density, relative to that of an emulsion made at the same time and in the same way except that the cadmium was omitted, was determined for a series of exposures to X-rays generated at 10 kilovolts, 65 kilovolts, 250 kilovolts and for exposure to the gamma rays of radium. The emulsion containing cadmium was found to be more than 50% faster than the emulsion containing no cadmium.
Development of the exposed X-raywas carried out 3 for 7 minutes at 20 C. in an X-ray developer having the following composition;
Water to make 50.0 mls.
The two solutions were first heated separately to a temperature of 50 C. and then mixed by adding Solution 2 to Solution 1 at a rate which allowed completion of addition within 1 minute. The emulsion obtained was digested for minutes at 50 C., poured into a parchment bag and dialysed at C. in order to remove the potassium nitrate. After dialysis, 100 mls. of water and a small amount of saponin were added and the emulsion coated onto a fdm base which was especially subbed for polyvinyl alcohol coatings. The X-ray and gamma ray speed of this very fine grain emulsion was about 50% higher than the speed of a type which had been prepared in an identical manner except that it did not contain any cadmium ions.
Example 111 Example H was repeated with the exception that the purification by dialysis was replaced by precipitation with ammonium sulfate, and that the precipitated particles were washed with water and remelted prior to coating.
Example IV An X-ray emulsion was made according to the following procedure.
Two solutions were prepared as follows:
Solution 1:
Water cc 150.0 Potassium bromide gms 60.0 Cadmium chloride gm 0.04 Gelatin gms 6.0 Solution 2:
Water cc 400 Silver nitrate gms 74 The two solutions were first heated and then mixed by adding Solution 2 to Solution 1 at a slow rate over a period of 1 hour, with constant agitation. Thereafter 60 grams of dry gelatin were added and the mixture maintained at 68 C. for 20 minutes, with agitation. The emulsion was then chilled, shredded, and washed until the bromide ion Concentration was 100 milligrams per kilogram of emulsion. The emulsion was remelted and after-ripened for 20 minutes at 60 C. A surfactant and a hardener were added and the emulsion was then coated onto a cellulose acetate support.
The speed of this emulsion, measured as the reciprocal of the exposure required to produce a density of 0.5 above base and fog density, relative to that of an emulsion made at the same time and in the same way except that the cadmium was omitted, was determined for a series of exposures to X-rays generated at 10 kilovolts, 65 kilovolts, 250 kilovolts, and for exposure to the gamma rays of radium. The emulsion containing cadmium was found to be about 50% faster than the emulsion containing no cadmium.
While the present invention has been described with reference to certain preferred procedures and uses, it is evident that the invention is not limited thereto, that variations, may be made in the procedure described herein and that equivalent materials may be substituted, without departing from the spirit and scope of the invention. For instance, silver bromo-iodide emulsions can be used in place of the silver bromide emulsions illustrated in the examples and it is to be understood that the term silver bromide as used in the appended claims is intended to embrace silver bromide emulsions in which from to of the weight of the silver halide is silver bromide. In place of the gelatin and polyvinyl alcohol illustrated in the examples, other colloidal carrier materials can be used such as water dispersible organic esters of cellulose, polyamides, hydroxyethyl cellulose, modified polyvinyl alcohol or partially hydrolyzed polyvinyl acetate. Special sensitizing agents which are known to the art can be added to the emulsions to increase their inherent speed.
In place of saponin, synthetic surfactants or wetting agents such as isopropylnaphthalene sulfonic acid can be used which aid in the preparation of even coatings without bubble formation. Color formers fast to diffusion and capable of forming, upon development with a primary amino developer, azometmne and quinonimine dye images, can be added to the emulsion in which case dye images are obtained upon color development with such primary amino developer.
We claim:
1. In a process of preparing a photographic silver halide emulsion in which the silver halide is predominantlysilver bromide, and wherein said process includes reacting a silver nitrate solution with an alkali metal halide solution in the presence of a dissolved colloidal carrier material so as to form a dispersion of silver halide grains in said colloidal carrier material, the improvement which comprises increasing the sensitivity of said emulsion to X-ray and gamma ray radiation by mixing said two solutions in the presence of a cadmium salt selected from the group consisting of cadmium chloride, cadmium bromide, cadmium nitrate and cadmium acetate, the concentration of the cadmium salt ranging from 0.001 to 0.2 mole percent of cadmium ion per mole of silver ion used in the preparation of the emulsion.
2. In a process of preparing a photographic silver bromide emulsion which includes mixing a silver nitrate solution with an alkali bromide solution containing a colloidal carrier material, the improvement which comprises adding to at least one of said solutions prior to mixing a water soluble carmium salt selected from the group consisting of cadmium chloride, cadmium bromide, cadmium nitrate and cadmium acetate in a concentration ranging from 0.001 to 0.2 mole percent of cadmium ion per mol of silver ion, thereby increasing the sensitivity of said emulsion to X-ray and gamma ray radiation.
3. A process according to claim 1 wherein said cadmium salt is cadmium nitrate.
4. A process according to claim 2 wherein said cadmium salt is cadmium nitrate.
5. A photographic emulsion prepared according to the process of claim 3.
6. A photographic emulsion prepared according to the process of claim 4.
7. A photographic emulsion prepared according to the process of claim 1.
8. A photographic emulsion prepared according to the process of claim 2.
9. A process according to claim 1 wherein said colloidal carrier material is gelatin.
10. A photographic material prepared according to the process of claim 9.
11. A process according to claim 1, wherein said colloidal carrier material is polyvinyl alcohol.
12. A photographic material prepared according to the process of claim 11.
13. A process according to claim 2, wherein said 001- loidal carrier material is gelatin.
14. A photographic material prepared according to the process of claim 13.
15. A process, according to claim 2, wherein said colloidal carrier material is polyvinyl alcohol.
16. A photographic material prepared according to the process of claim 15.
17. A process according to claim 1 wherein said cadmium salt is added to the alkali metal halide solution.
18. A process according to claim 2 wherein said cadmium salt is added to the alkali bromide solution.
19. A process according to claim 2 wherein said cadmium salt is cadmium acetate, and the cadmium actate is added to the silver nitrate solution.
Wall:
UNITED STATES PATENTS Waller et al Apr. 23, 1946 Dimsdale et al. Dec. 16, 1947 Staufier et al. May 27, 1952 Hewitson et a1. Nov. 18, 1952 Russell Oct. 23, 1956 FOREIGN PATENTS Great Britain July 26, 1917 OTHER REFERENCES Photographic Emulsions, pages 232-234,
American Photographic Publishing Co., Boston (1929).
UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No, 2,950,972 August 30, 1960 Column 2, line 17, for wihch" read which collim'n 4, line 30, for "lysilver" read 1 y silver line 48,, for "carmium" read cadmium Signed and sealed this 4th day of April 1961.,
(SEAL) Attest: ERNEST W. SWIDER XMXXXXXQX ARTHUR w. CROCKER Attesting Oflicer Acting Commissioner of Patents
Claims (1)
1. IN A PROCESS OF PREPARING A PHOTOGRAPHIC SILVER HALIDE EMULSION IN WHICH THE SILVER HALIDE IS PREDOMINANTLY SILVER BROMIDE, AND WHEREIN SAID PROCESS INCLUDES REACTING A SILVER NITRATE SOLUTION WITH AN ALKALI METAL HALIDE SOLUTION IN THE PRESENCE OF A DISSOLVED COLLOIDAL CARRIER MATERIAL SO AS TO FORM A DISPERSION OF SILVER HALIDE GRAINS IN SAID COLLOIDAL CARRIER MATERIAL, THE IMPROVEMENT WHICH COMPRISES INCREASING THE SENSITIVITY OF SAID EMULSION TO X-RAY AND GAMMA RAY RADIANTION BY MIXING SAID TWO SOLUTIONS IN THE PRESENCE OF A CADMIUM SALT SELECTED FROM THE GROUP CONSISTING OF CADMIUM CHLORIDE, CADMIUM BROMIDE, CADMIUM NITRATE AND CADMIUM ACETATE, THE CONCENTRATION OF THE CADMIUM SALT RANGING FROM 0.001 TO 0.2 MOLE PERCENT OF CADMIUM ION PER MOLE OF SILVER ION USED IN THE PREPARATION OF THE EMULSION.
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US471106A US2950972A (en) | 1954-11-24 | 1954-11-24 | Photographic emulsions having increased sensitivity to x-ray and gamma ray radiation |
GB31486/55A GB786924A (en) | 1954-11-24 | 1955-11-03 | Photographic emulsions having increased sensitivity to x-ray and gamma ray radiation |
DEG18427A DE1022468B (en) | 1954-11-24 | 1955-11-22 | Photographic emulsions with increased sensitivity to X-rays and ª rays and processes for their preparation |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US471106A US2950972A (en) | 1954-11-24 | 1954-11-24 | Photographic emulsions having increased sensitivity to x-ray and gamma ray radiation |
Publications (1)
Publication Number | Publication Date |
---|---|
US2950972A true US2950972A (en) | 1960-08-30 |
Family
ID=23870278
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US471106A Expired - Lifetime US2950972A (en) | 1954-11-24 | 1954-11-24 | Photographic emulsions having increased sensitivity to x-ray and gamma ray radiation |
Country Status (3)
Country | Link |
---|---|
US (1) | US2950972A (en) |
DE (1) | DE1022468B (en) |
GB (1) | GB786924A (en) |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3597610A (en) * | 1968-02-22 | 1971-08-03 | Eastman Kodak Co | Intensification screen for radiographic film |
US3854952A (en) * | 1973-09-19 | 1974-12-17 | Western Electric Co | Photosensitive silver halide composition |
US3874881A (en) * | 1972-03-14 | 1975-04-01 | Fuji Photo Film Co Ltd | Sensitizing a mixture of silver halide and lead halide by heat |
EP0017148A1 (en) * | 1979-04-05 | 1980-10-15 | EASTMAN KODAK COMPANY (a New Jersey corporation) | Internally doped high chloride silver halide emulsions, processes for their preparation and photographic elements |
US4269927A (en) * | 1979-04-05 | 1981-05-26 | Eastman Kodak Company | Internally doped surface sensitized high chloride silver halide emulsions and photograhic elements and processes for their preparation |
EP0198634A2 (en) | 1985-04-04 | 1986-10-22 | EASTMAN KODAK COMPANY (a New Jersey corporation) | Quaternized tellurium salt fog inhibiting agents for silver halide photography |
US4835093A (en) * | 1988-04-08 | 1989-05-30 | Eastman Kodak Company | Internally doped silver halide emulsions |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3123474A (en) * | 1958-05-26 | 1964-03-03 | byrne | |
US3147117A (en) * | 1961-05-26 | 1964-09-01 | Horizons Inc | Process of forming print-out images from light sensitive organic amine compositions |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB108193A (en) * | 1916-07-26 | 1917-07-26 | Edouard Blondel La Rougery | Improvements in or relating to Photography. |
US2399083A (en) * | 1942-02-13 | 1946-04-23 | Ilford Ltd | Photographic materials |
US2432865A (en) * | 1944-02-03 | 1947-12-16 | Ilford Ltd | Photographic elements having light-sensitive silver halide layers containing iron, cobalt and nickel derivatives of mercapto tetrazoles, triazoles or diazoles |
US2598079A (en) * | 1948-08-31 | 1952-05-27 | Eastman Kodak Co | High-speed photographic silver halide emulsions supersensitized with palladium salts |
US2618556A (en) * | 1947-11-19 | 1952-11-18 | Eastman Kodak Co | Process for preparing photographic emulsions |
US2768079A (en) * | 1954-01-25 | 1956-10-23 | Eastman Kodak Co | Method of preparing washed photographic emulsions |
-
1954
- 1954-11-24 US US471106A patent/US2950972A/en not_active Expired - Lifetime
-
1955
- 1955-11-03 GB GB31486/55A patent/GB786924A/en not_active Expired
- 1955-11-22 DE DEG18427A patent/DE1022468B/en active Pending
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB108193A (en) * | 1916-07-26 | 1917-07-26 | Edouard Blondel La Rougery | Improvements in or relating to Photography. |
US2399083A (en) * | 1942-02-13 | 1946-04-23 | Ilford Ltd | Photographic materials |
US2432865A (en) * | 1944-02-03 | 1947-12-16 | Ilford Ltd | Photographic elements having light-sensitive silver halide layers containing iron, cobalt and nickel derivatives of mercapto tetrazoles, triazoles or diazoles |
US2618556A (en) * | 1947-11-19 | 1952-11-18 | Eastman Kodak Co | Process for preparing photographic emulsions |
US2598079A (en) * | 1948-08-31 | 1952-05-27 | Eastman Kodak Co | High-speed photographic silver halide emulsions supersensitized with palladium salts |
US2768079A (en) * | 1954-01-25 | 1956-10-23 | Eastman Kodak Co | Method of preparing washed photographic emulsions |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3597610A (en) * | 1968-02-22 | 1971-08-03 | Eastman Kodak Co | Intensification screen for radiographic film |
US3874881A (en) * | 1972-03-14 | 1975-04-01 | Fuji Photo Film Co Ltd | Sensitizing a mixture of silver halide and lead halide by heat |
US3854952A (en) * | 1973-09-19 | 1974-12-17 | Western Electric Co | Photosensitive silver halide composition |
EP0017148A1 (en) * | 1979-04-05 | 1980-10-15 | EASTMAN KODAK COMPANY (a New Jersey corporation) | Internally doped high chloride silver halide emulsions, processes for their preparation and photographic elements |
US4269927A (en) * | 1979-04-05 | 1981-05-26 | Eastman Kodak Company | Internally doped surface sensitized high chloride silver halide emulsions and photograhic elements and processes for their preparation |
EP0198634A2 (en) | 1985-04-04 | 1986-10-22 | EASTMAN KODAK COMPANY (a New Jersey corporation) | Quaternized tellurium salt fog inhibiting agents for silver halide photography |
US4835093A (en) * | 1988-04-08 | 1989-05-30 | Eastman Kodak Company | Internally doped silver halide emulsions |
Also Published As
Publication number | Publication date |
---|---|
GB786924A (en) | 1957-11-27 |
DE1022468B (en) | 1958-01-09 |
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