US2870015A - Stabilized photographic silver halide emulsions - Google Patents

Stabilized photographic silver halide emulsions Download PDF

Info

Publication number
US2870015A
US2870015A US644733A US64473357A US2870015A US 2870015 A US2870015 A US 2870015A US 644733 A US644733 A US 644733A US 64473357 A US64473357 A US 64473357A US 2870015 A US2870015 A US 2870015A
Authority
US
United States
Prior art keywords
emulsions
silver halide
fog
photographic
emulsion
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US644733A
Other languages
English (en)
Inventor
Charles F H Allen
John J Sagura
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Eastman Kodak Co
Original Assignee
Eastman Kodak Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to BE565380D priority Critical patent/BE565380A/xx
Application filed by Eastman Kodak Co filed Critical Eastman Kodak Co
Priority to US644733A priority patent/US2870015A/en
Priority to FR1202249D priority patent/FR1202249A/fr
Priority to GB7200/58A priority patent/GB884514A/en
Application granted granted Critical
Publication of US2870015A publication Critical patent/US2870015A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D275/00—Heterocyclic compounds containing 1,2-thiazole or hydrogenated 1,2-thiazole rings
    • C07D275/04—Heterocyclic compounds containing 1,2-thiazole or hydrogenated 1,2-thiazole rings condensed with carbocyclic rings or ring systems
    • 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
    • G03C1/34—Fog-inhibitors; Stabilisers; Agents inhibiting latent image regression
    • G03C1/346—Organic derivatives of bivalent sulfur, selenium or tellurium

Definitions

  • Fog depends both on the emulsion and the conditions of. development; for a given emulsion it increases With the degree of development; With constant development conditions, it tends to increase with time, temperature and relative humidity of storage conditions; it is common practice to make accelerated tests of the stability of photo graphic emulsions by storage at increased temperature or humidity, or both. It is, of course, desirable to have emulsions as stable as possible under the conditions of high temperature and humidity which may occur in tropical climates, for example.
  • Fog usually appears over the 1 whole area of the sensitive coating, ⁇ but when'severe, it frequently is non-uniform; Fog may also be caused by exposure to chemicals, for example, hydrogen sulfide, and other reactive sulfur compounds, hydrogen peroxide vapor, and strongly reducing materials; While antifoggants and stabilizers may protect, to some extent, agains t such effects, it is normally understood that an antifoggant protects again st spontaneous growth of fog during prolonged storage or storage at high temperaturesand li lmtdities, or during development to maximum contrast and speed,
  • anobject of our invention to provide a method for stabilizing photographic silver halide emulsions. Another object is to maintain the sensitivity and fog of photographic silver halide emulsions at or close to initial optimum 'valuesunder keeping conditions of high temperature and humidity. A further-object is toprovide photographic silver halide emulsions containing antifoggarits -or stabilizers. Other objects will become apparent from a consideration of the followiug description and examples.
  • D represents the non metallic atoms necessary to complete a monocyclic aromaticgroup of the benzene series, such as benzene or substituted benzenes (i. e., benzene substituted by such radicals as chlorine, bromine, methoxyl, ethoxyl, methyl, ethyl, tc.).
  • the fog-inhibitors which we propose to use are added to the emulsion dur n he. pre ets-of. naautas to avoid loss of sensitivity and to inhibit the growth of fog with passage of time under non-ideal conditions of storage.
  • a solution of the compounds of the invention when added in suitable concentration, before coating, to unsensitized, chemically sensitized, or. optically sensitized photographic emulsions may not appreciably affect the sensitometric values for sensitivity and fo when measurements are made soon after coating.
  • sensitometric measurements are made at appreciable intervals of time, at elevatedtemperatures and dry or somewhat humid conditions, these compounds do stabilize photographic -speed and maintainfog at alow-level.
  • Thepreparatiori of silverhalide emulsions involves three separate operations: '(1) the emulsificationand digestion :or ripening of the silver halide, (2) the freeing of the emulsion from excess soluble salts, usually by washing, and (3) the second digestion of after-ripening prior to digestion.
  • th sis R er ata- Mas s an ass I Listed below are a number of compounds-coming within the scope of Formula I above which we have found to be particularly advantageous in practicingour inven- 2,8-dihydro-3-oigobenzoisothiazole (av s t -GHI c ll :2,3 si siro-z th aos snz is th aaqls Q SC I ll 2,3-dihydro-2-ethy1-3: oxcheuaoisothiaaole I (MeesflThe Theory of 2-n-butyl-2,3-dihydro-3-oxobenzoisothlaz01e 2-cety1-2,3dihydro-3-oxobenzolsothtazole /N--C ⁇ G H O 2-benzothiazy1-2,3-dihydro-3-oxoheuzoisothiazole (7) s N C
  • antifoggant compounds used in our invention have been found particularly useful when employed in conjunction with gelatinosilver-bromiodide emulsions, although they can also be advantageously employed for stabilizing other silver halide emulsions, such as gelatino-silverchloride, bromide, chlorobromide, chlorobromiodide, etc.
  • the emulsions can also be chemically sensitized by any of the accepted procedures.
  • the emulsions can be digested with naturally active gelatin, or sulfur compounds can be added such as those described in Sheppard U. S. Patent 1,574,944 and ,U.' S. 1,623,499, and Sheppard and Brigham U. S. Patent 2,410,689.
  • the emulsions can also be treated with salts of the noble metals such as ruthenium, rhodium, palladium, iridium and platinum, all of which belong to group VIII of the periodic table of elements and have an atomic weight greater than 100.
  • Representative compounds are ammonium chloropalladate, potassium chloroplatinate and sodium chloropalladite, which are used for sensitizing in amounts below that which produces any substantial fog inhibition, as described in Smith and Trivelli U. S. Patent 2,448,060, and as antifoggants in higher amounts, as described in Trivelli andSmith US. Patents 2,566,245 and 2,566,263.
  • the emulsions can also bechemically sensitized with gold salts as describedin'Waller and Dodd U. S. Patent 2,399,083, or stabilized with gold salts as described in Damschroder U. S. Patent 2,597,85 6 and Yutzy and Leermakers U. S. Patent 2,597,915, Suitable compounds are potassium chloroaurite, potassium aurithiocyanate, potassium chloroauratqauric trichloride and Z-aurosulfobenzothiazole methochlorid'e.
  • the emulsions can also be chemically sensitized with reducing agents such as stannous salts (Carroll U. S. Patent 2,487,850), polyamines such as diethylene triamine (Lowe and Jones U. S. Patent 2,518,698), polyamines, such as spermine (Lowe and Allen U. S. Patent 2,521,925), or bis-(fi-aminoethynsulfide and its watersoluble salts (Lowe and Jones U. S. Patent 2,521,926).
  • reducing agents such as stannous salts (Carroll U. S. Patent 2,487,850), polyamines such as diethylene triamine (Lowe and Jones U. S. Patent 2,518,698), polyamines, such as spermine (Lowe and Allen U. S. Patent 2,521,925), or bis-(fi-aminoethynsulfide and its watersoluble salts (Lowe and Jones U. S. Patent 2,521,926).
  • the emulsions can also be stabilized with the mercury compounds of Allen, Byers and Murray U. S. Patent 2,728,663, Carroll and Murray U. S. Patent 2,728,664, and Leubner and Murray U. S. Patent 2,728,665.
  • the stabilizing combinations of our compounds are effective in the presence or absence of optical sensitizing dyes. Since optical sensitizing may affect stability of emulsions with respect to sensitivity, fog and latent image changes, the action of the compounds of this invention is not completely independent of optical sensitizing or other emulsion variables. We have found, however, that both unsensitized emulsions and emulsions sensitized with cyanine or merocyanine dyes, or both, can be treated according to our invention.
  • the antifoggant and/or stabilizing action was determined by incubation of the emulsions for one week at a temperature of F. and constant relative humidity (obtained by placing the emulsions'in closed containers, the ambient temperature being about 70 F. and relative humidity about 50-55 percent prior to sealing the containers).
  • the etficiency of the various antifoggants was determined by measuring the speed, gamma and fog of the incubated emulsions containing an antifoggant and comparing these measurements with those of the same batch of emulsion before incubation. Also, similar measurements were made with a photographic emulsion containing no antifoggant both before and after incubation.
  • test films were exposed on an intensity scale sensitometer and developed for 5 minutes in a developer having the following composition:
  • Suitable dispersing agents for the silver halide emulsions stabilized according to our invention comprise gelatin, or other colloids, such as collodion, albumen, celluloseorg'anic derivatives, synthetic resins, etc.
  • the optimum amount of fog-inhibiting agent can be determined by making ;the customary tests employed in emulsion making. f course, the optimum amount for a given emulsion will varydepending on the presence of emulsion iaddenda, such as chemical ;sensitizers, optical sensitizers, etc. In general, we have found that from 0.001 to 5.0 g. of fog-inhibting agent per mole of silver halide is suflicient for the purposes of our invention.
  • the antifoggants ;of our invention functionadvantageou'sly in acid for alkaline photographic silver halideernul'sions. 7
  • certainnitrogen-containing compounds other than those of Formula I above can be used in photographic gsilver halide emulsions, frequently to give antifoggant .or stabilizing effects.
  • Such compounds include, for example, "ethylfurfurylidenedicarba'mate, The Furans," A. -C. :S. "Monograph No. 119' (1953), page 374, which can also be named furfurylidenebisurethane (ethyl ester).
  • furfurylidenebisurethane ethyl ester
  • Other related nitrogencontaining compounds, such as ethylidenebisurethane such as ethylidenebisurethane
  • Solution A grams of n-cetylamine were dissolved in 50 cc. of pyridine and 200 cc. of anhydrous carbon tetrachloride with warming.
  • Solution B grams of dithiodibenzoylchloride were i "added to 100 cc. of carbon tetrachloride and chlorinewas passed into the mixture until the dithiodibenzoylchloride had dissolved. Nitrogen was then passed into the container holding the solution to remove excess chlorine. The solution was then filtered.
  • Solution A was warmed to 55 C. to keep in solution and Solution B was slowly added to Solution A with stirring. The temperature rose to 60 C. and crystals appearing to be pyridine hydrochloride separated. After cooling to ambient temperature, the reaction mixture was poured onto one liter of ice and made acid (with hydrochloric acid) to Congo red. The carbon tetrachloride layer was separated and washed with cold water. The carbon tetrachloride solution was dried over calcium chloride, decolorized with decolorizing carbon and dried over magnesium sulfate. The solution was filtered and concentrated under reduced pressure on the steam bath. The concentrated solution was dissolved in ethyl alcohol, treated once again with decolorizing carbon, filtered and The put in the refrigerator. The desired material crystallized Two solutions were prepared as follows:
  • Solution A -7 grams of dithiodibenzoylchloride were added to cc. of carbon tetrachloride and chlorine passed into the mixture until complete solution ensued. Excess chlorine was then removed by passing in nitrogen gas and the solution was filtered.
  • Solution B 6 grams of Z-aminobenzothiazole were dissolved in a mixture of 50 cc. of pyridine and cc. of carbon tetrachloride.
  • Solution A was-added to Solution B slowly, the temperature rising to 45 C. during the addition.
  • the desired product separated immediately as crystalline material.
  • the reaction mixture was allowed to stand for an additional 1.5 hours and then filtered.
  • the filter cake was washed with 100 cc. of water to remove any pyridine hydrochloride present.
  • Thedesired product was recrystallized from dimethyl- 'forin'amid'e, collected on a filter, leached in diethyl ether,
  • R represents a member selected from the group consisting of a hydrogen atom, an alkyl group, a benzothiazyl group, a benzoxazyl group, and a pyridyl group and D represents the non-metallic atoms necessary to complete a benzene ring.
  • R represents a member selected from the group consisting of a hydrogen atom, an alkyl group, a hen zothiazyl group, a benzoxazyl group, and a pyridyl group.
  • R represents an alkyl group containing from l to 4 carbon atoms.
  • R represents a member selected from the group consisting of a hydrogen atom, an alkyl group, a henzothiazyl group, a benzoxazyl group, and a pyridyl group
  • D represents the non-metallic atoms necessary to complete a benzene ring.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • General Physics & Mathematics (AREA)
  • Thiazole And Isothizaole Compounds (AREA)
  • Plural Heterocyclic Compounds (AREA)
US644733A 1957-03-08 1957-03-08 Stabilized photographic silver halide emulsions Expired - Lifetime US2870015A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
BE565380D BE565380A (enrdf_load_html_response) 1957-03-08
US644733A US2870015A (en) 1957-03-08 1957-03-08 Stabilized photographic silver halide emulsions
FR1202249D FR1202249A (fr) 1957-03-08 1958-03-06 Nouveau produit photographique stabilisé
GB7200/58A GB884514A (en) 1957-03-08 1958-03-06 Improvements in photographic silver halide emulsions

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US644733A US2870015A (en) 1957-03-08 1957-03-08 Stabilized photographic silver halide emulsions

Publications (1)

Publication Number Publication Date
US2870015A true US2870015A (en) 1959-01-20

Family

ID=24586122

Family Applications (1)

Application Number Title Priority Date Filing Date
US644733A Expired - Lifetime US2870015A (en) 1957-03-08 1957-03-08 Stabilized photographic silver halide emulsions

Country Status (4)

Country Link
US (1) US2870015A (enrdf_load_html_response)
BE (1) BE565380A (enrdf_load_html_response)
FR (1) FR1202249A (enrdf_load_html_response)
GB (1) GB884514A (enrdf_load_html_response)

Cited By (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3012039A (en) * 1958-03-14 1961-12-05 Ici Ltd 2-p-chlorobenzyl-1, 2-benzisothiazolone
DE1135468B (de) * 1960-03-24 1962-08-30 Wander Ag Dr A Verfahren zur Herstellung von 6-Chlor-benzisothiazolon
US3065123A (en) * 1959-06-24 1962-11-20 Ici Ltd Process for control of micro-organisms
US3068100A (en) * 1960-11-14 1962-12-11 Gen Aniline & Film Corp N-acylhomocysteine thiolactone stabilizers for photographic silver halide emulsions
US3081170A (en) * 1958-10-06 1963-03-12 Gen Aniline & Film Corp Fog reduction in photographic silver halide emulsions
DE1147947B (de) * 1961-07-25 1963-05-02 Knoll Ag Verfahren zur Herstellung neuer 1, 2-Benzisothiazolone
US3161520A (en) * 1962-12-11 1964-12-15 Gen Aniline & Film Corp Fog reduction in photographic silver halide emulsions
US3238220A (en) * 1961-12-20 1966-03-01 Bayer Ag 3-hydroxy-benzisoxazoles and their production
US3300378A (en) * 1960-03-24 1967-01-24 Wander Ag Dr A Disinfectant and anti-inflammatory composition and method of using same
US3517022A (en) * 1967-10-03 1970-06-23 Rohm & Haas Certain 2-carbamoyl-1,2-benzisothiazolones
US4113728A (en) * 1975-11-18 1978-09-12 Beecham Group Limited 2-Substituted benzisothiazolones
US4224403A (en) * 1977-08-03 1980-09-23 Fuji Photo Film Co., Ltd. Method for preventing the degradation of a hydrophilic colloid solution for silver halide photographic light-sensitive material
US4349623A (en) * 1979-06-15 1982-09-14 Fuji Photo Film Co., Ltd. Silver halide photographic materials
JPS59226344A (ja) * 1983-06-06 1984-12-19 Konishiroku Photo Ind Co Ltd 写真用水性組成物の防腐方法
US4490462A (en) * 1982-03-27 1984-12-25 Konishiroku Photo Industry Co., Ltd. Light-sensitive silver halide photographic material
DE3517396A1 (de) * 1984-05-15 1985-11-21 Konishiroku Photo Industry Co., Ltd., Tokio/Tokyo Verfahren zum behandeln eines photographischen silberhalogenidmaterials
US5153116A (en) * 1988-10-31 1992-10-06 Konica Corporation Silver halide photographic light sensitive material excellent in antistatic property
US5185240A (en) * 1989-08-11 1993-02-09 Fuji Photo Film Co., Ltd. Silver halide photographic material
US5441852A (en) * 1991-12-27 1995-08-15 Konica Corporation Method of stabilizing a color silver halide image
WO1996022023A1 (en) * 1995-01-17 1996-07-25 Zeneca Limited Composition and use
US5580705A (en) * 1991-12-27 1996-12-03 Konica Corporation Method of bleaching silver halide color photographic light-sensitive materials using particular ferric chelates
US5866633A (en) * 1995-03-08 1999-02-02 Eastman Kodak Company Material and method for inhibiting bacterial growth in an aqueous medium
US6117611A (en) * 1998-12-14 2000-09-12 Konica Corporation Image forming method of a silver halide photographic light-sensitive material
US6214529B1 (en) 1998-10-22 2001-04-10 Eastman Kodak Company Method of suppressing fog in silver halide emulsions
US6350567B1 (en) 1998-10-22 2002-02-26 Eastman Kodak Company Precipitation of high chloride content silver halide emulsions

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5468602A (en) * 1993-11-10 1995-11-21 Konica Corporation Method for producing silver halide photographic light-sensitive material

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1725934A (en) * 1925-01-31 1929-08-27 Agfa Ansco Corp Silver-halide photographic emulsion and process of making the same

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1725934A (en) * 1925-01-31 1929-08-27 Agfa Ansco Corp Silver-halide photographic emulsion and process of making the same

Cited By (30)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3012039A (en) * 1958-03-14 1961-12-05 Ici Ltd 2-p-chlorobenzyl-1, 2-benzisothiazolone
US3081170A (en) * 1958-10-06 1963-03-12 Gen Aniline & Film Corp Fog reduction in photographic silver halide emulsions
US3065123A (en) * 1959-06-24 1962-11-20 Ici Ltd Process for control of micro-organisms
US3300378A (en) * 1960-03-24 1967-01-24 Wander Ag Dr A Disinfectant and anti-inflammatory composition and method of using same
DE1135468B (de) * 1960-03-24 1962-08-30 Wander Ag Dr A Verfahren zur Herstellung von 6-Chlor-benzisothiazolon
US3068100A (en) * 1960-11-14 1962-12-11 Gen Aniline & Film Corp N-acylhomocysteine thiolactone stabilizers for photographic silver halide emulsions
US3227715A (en) * 1961-07-25 1966-01-04 Knoll Ag Benzisothiazolones
DE1147947B (de) * 1961-07-25 1963-05-02 Knoll Ag Verfahren zur Herstellung neuer 1, 2-Benzisothiazolone
US3238220A (en) * 1961-12-20 1966-03-01 Bayer Ag 3-hydroxy-benzisoxazoles and their production
US3161520A (en) * 1962-12-11 1964-12-15 Gen Aniline & Film Corp Fog reduction in photographic silver halide emulsions
US3517022A (en) * 1967-10-03 1970-06-23 Rohm & Haas Certain 2-carbamoyl-1,2-benzisothiazolones
US4113728A (en) * 1975-11-18 1978-09-12 Beecham Group Limited 2-Substituted benzisothiazolones
US4224403A (en) * 1977-08-03 1980-09-23 Fuji Photo Film Co., Ltd. Method for preventing the degradation of a hydrophilic colloid solution for silver halide photographic light-sensitive material
US4349623A (en) * 1979-06-15 1982-09-14 Fuji Photo Film Co., Ltd. Silver halide photographic materials
US4490462A (en) * 1982-03-27 1984-12-25 Konishiroku Photo Industry Co., Ltd. Light-sensitive silver halide photographic material
JPS59226344A (ja) * 1983-06-06 1984-12-19 Konishiroku Photo Ind Co Ltd 写真用水性組成物の防腐方法
DE3517396A1 (de) * 1984-05-15 1985-11-21 Konishiroku Photo Industry Co., Ltd., Tokio/Tokyo Verfahren zum behandeln eines photographischen silberhalogenidmaterials
US4778746A (en) * 1984-05-15 1988-10-18 Konishiroku Photo Industry Co., Ltd. Method of processing a silver halide photographic material
DE3517396C2 (de) * 1984-05-15 1998-04-30 Konishiroku Photo Ind Verfahren zum Behandeln eines photographischen Silberhalogenidmaterials
US5153116A (en) * 1988-10-31 1992-10-06 Konica Corporation Silver halide photographic light sensitive material excellent in antistatic property
US5185240A (en) * 1989-08-11 1993-02-09 Fuji Photo Film Co., Ltd. Silver halide photographic material
US5580705A (en) * 1991-12-27 1996-12-03 Konica Corporation Method of bleaching silver halide color photographic light-sensitive materials using particular ferric chelates
US5441852A (en) * 1991-12-27 1995-08-15 Konica Corporation Method of stabilizing a color silver halide image
WO1996022023A1 (en) * 1995-01-17 1996-07-25 Zeneca Limited Composition and use
RU2157820C2 (ru) * 1995-01-17 2000-10-20 Зенека Лимитед Композиция для защиты пластиков и способ ее применения
US5866633A (en) * 1995-03-08 1999-02-02 Eastman Kodak Company Material and method for inhibiting bacterial growth in an aqueous medium
US5932183A (en) * 1995-03-08 1999-08-03 Eastman Kodak Company Material and method for inhibiting bacterial growth in an aqueous medium
US6214529B1 (en) 1998-10-22 2001-04-10 Eastman Kodak Company Method of suppressing fog in silver halide emulsions
US6350567B1 (en) 1998-10-22 2002-02-26 Eastman Kodak Company Precipitation of high chloride content silver halide emulsions
US6117611A (en) * 1998-12-14 2000-09-12 Konica Corporation Image forming method of a silver halide photographic light-sensitive material

Also Published As

Publication number Publication date
FR1202249A (fr) 1960-01-08
BE565380A (enrdf_load_html_response)
GB884514A (en) 1961-12-13

Similar Documents

Publication Publication Date Title
US2870015A (en) Stabilized photographic silver halide emulsions
US2566263A (en) Stabilizing photographic emulsions with chloropalladites and chloroplatinites
US2839405A (en) Inorganic salt antifoggants for photographic emulsions
US2819965A (en) Carboxymethylmercapto compounds as stabilizers for photographic emulsions
US3137578A (en) Photographic emulsions containing 2-heterocyclic benzimidazole antifoggants
US2772164A (en) Photographic silver halide emulsions containing 1-thia-3, 5, 7-triazaindenes
US2981624A (en) Antifoggants and stabilizers for photographic silver halide emulsion
US2843491A (en) 2-mercapto-1, 3, 4-oxadiazoles as antifoggants
US3615617A (en) Stabilized photographic material with tetrazole thiocarbonic acid ester
US2743181A (en) Stabilized photographic silver halide emulsions
US2743180A (en) Pentazaindene stabilizers for photo-graphic emulsions sensitized with alkylene oxide polymers
US2824001A (en) Stabilized photographic silver halide emulsions
US2835581A (en) Tetrazaindenes and photographic emulsions containing them
US2887378A (en) Photographic silver halide emulsions containing thiol compounds
US2552229A (en) Fog inhibitors for photographic emulsions
US2756147A (en) Tetrazaindene stabilizer for photographic emulsions sensitized with alkylene oxide polymers
US2728664A (en) Photographic emulsions containing mercury salts
US2897081A (en) Antifogging agent and bactericide for photographic emulsions
US2852375A (en) New tetrazaindene compounds and photographic emulsions containing them
US2728667A (en) Molecular compounds of mercury salts with benzothiazoles as fog inhibitors in a silver halide emulsion
US2891862A (en) Stabilized photographic silver halide emulsions
US2704716A (en) Melonate and cyamelurate stabilizers for photographic emulsions sensitized with alkylene oxide polymers
US2784090A (en) Stabilization of emulsions sensitized with onium compounds
US2860985A (en) Stabilization of photographic silver halide emulsions and means of increasing contrast
US2708161A (en) Parabanic acid stabilizer for photographic emulsions sensitized with alkylene oxide polymers