US2139774A - Sensitizing and hardening photographic emulsions - Google Patents
Sensitizing and hardening photographic emulsions Download PDFInfo
- Publication number
- US2139774A US2139774A US90000A US9000036A US2139774A US 2139774 A US2139774 A US 2139774A US 90000 A US90000 A US 90000A US 9000036 A US9000036 A US 9000036A US 2139774 A US2139774 A US 2139774A
- Authority
- US
- United States
- Prior art keywords
- emulsion
- hardening
- sensitizing
- emulsions
- gelatin
- 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
Links
- 239000000839 emulsion Substances 0.000 title description 55
- 230000001235 sensitizing effect Effects 0.000 title description 7
- 239000003795 chemical substances by application Substances 0.000 description 15
- 238000000034 method Methods 0.000 description 13
- 238000011534 incubation Methods 0.000 description 12
- 108010010803 Gelatin Proteins 0.000 description 11
- 229920000159 gelatin Polymers 0.000 description 11
- 239000008273 gelatin Substances 0.000 description 11
- 235000019322 gelatine Nutrition 0.000 description 11
- 235000011852 gelatine desserts Nutrition 0.000 description 11
- 230000008569 process Effects 0.000 description 9
- 229910052709 silver Inorganic materials 0.000 description 8
- 239000004332 silver Substances 0.000 description 8
- 230000029087 digestion Effects 0.000 description 7
- 239000011248 coating agent Substances 0.000 description 6
- 238000000576 coating method Methods 0.000 description 6
- 238000001035 drying Methods 0.000 description 6
- 238000000209 wet digestion Methods 0.000 description 6
- 238000010438 heat treatment Methods 0.000 description 5
- -1 hydroxy aldehydes Chemical class 0.000 description 5
- 238000002844 melting Methods 0.000 description 5
- 230000008018 melting Effects 0.000 description 5
- OJVAMHKKJGICOG-UHFFFAOYSA-N 2,5-hexanedione Chemical compound CC(=O)CCC(C)=O OJVAMHKKJGICOG-UHFFFAOYSA-N 0.000 description 4
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 description 3
- 230000001376 precipitating effect Effects 0.000 description 3
- 230000005070 ripening Effects 0.000 description 3
- 230000035945 sensitivity Effects 0.000 description 3
- 230000008961 swelling Effects 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- 230000009471 action Effects 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- VKYKSIONXSXAKP-UHFFFAOYSA-N hexamethylenetetramine Chemical compound C1N(C2)CN3CN1CN2C3 VKYKSIONXSXAKP-UHFFFAOYSA-N 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 206010010071 Coma Diseases 0.000 description 1
- 206010070834 Sensitisation Diseases 0.000 description 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- PXAJQJMDEXJWFB-UHFFFAOYSA-N acetone oxime Chemical compound CC(C)=NO PXAJQJMDEXJWFB-UHFFFAOYSA-N 0.000 description 1
- 150000001299 aldehydes Chemical class 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 230000006399 behavior Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- OIDPCXKPHYRNKH-UHFFFAOYSA-J chrome alum Chemical compound [K]OS(=O)(=O)O[Cr]1OS(=O)(=O)O1 OIDPCXKPHYRNKH-UHFFFAOYSA-J 0.000 description 1
- 238000000586 desensitisation Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- NKDDWNXOKDWJAK-UHFFFAOYSA-N dimethoxymethane Chemical compound COCOC NKDDWNXOKDWJAK-UHFFFAOYSA-N 0.000 description 1
- 239000004312 hexamethylene tetramine Substances 0.000 description 1
- 235000010299 hexamethylene tetramine Nutrition 0.000 description 1
- WSFSSNUMVMOOMR-NJFSPNSNSA-N methanone Chemical compound O=[14CH2] WSFSSNUMVMOOMR-NJFSPNSNSA-N 0.000 description 1
- 229960004011 methenamine Drugs 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 150000002972 pentoses Chemical class 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000008313 sensitization Effects 0.000 description 1
- HFFLGKNGCAIQMO-UHFFFAOYSA-N trichloroacetaldehyde Chemical compound ClC(Cl)(Cl)C=O HFFLGKNGCAIQMO-UHFFFAOYSA-N 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
- G03C1/30—Hardeners
Definitions
- This invention relates to finishing photographic emulsions and particularly, to sensitizing and hardening gelatino-silver halide emulsions.
- a gelatino-silver halide emulsion when first mixed is quite slow or insensitive, and unsatisfactory for making fast negative emulsions.
- the emulsion mixture is, therefore, digested or ripened in orderto increase the sensitivity.
- This ripening is ordinarily accomplished by the action of heat or by digestion with ammonia, either alone or in combination with heating. After treatment in this way the emulsion may be jelled and set and then re-melted and coated on the emulsion support.
- the hardening agent is added at some period subsequent to the digestion, before coating the emulsion on the support.
- the degree of hardening produced in this way is not complete after drying the product, but-a greater or lesser amount of so-called after hardening occurs on storage 5 of the plates or films. This may continue through a period of months'and may equal or surpass in degree the initial hardening on first drying. This after hardening, therefore, gives rise to a product whose properties are variable with time unless an inconvenientiy long period of storage prior to use is involved.
- One consequence of this is generally reduction of speed of development, but other objectionable changes in photographic properties may ensue.
- a further objection is that it is necessary to repeatedly subject samples of the plates or films to incubation tests in order to ascertain the amount of hardening that has taken place.'
- an object of the present invention to provide a means for eliminating after hardening and for producing a more stable emulsion which will show less change in regard to sensitometric and physical properties, such as hardening and swelling, on storage.
- a further object is to provide a novel method for hardening photographic emulsions.
- a still further object is to provide a photographic emulsion which will be resistant to relatively high temperatures without objectionable fogging or de-sensitizing. Other objects will appear hereinafter.
- the plate or film is then subjected to the heat treatment described below and the combined sensitizing and hardening action performed in this way.
- This dry digestion or moist incubation has a number of advantages over the usual wet digestion in which the emulsions are ripened prior to addition of the hardening agent, in that the progress of the hardening is more conveniently controlled and that there is less tendency to increased fogging with increasing sensitization. This is shown by the following tables indicating the speed of plates, subjected to digestion and obtained by moist incubation (for 3.5 hours) was nearly, twice that obtained by wet digestion (at twenty minutes) for a corresponding amount of fog formation.
- melting point is meant the temperature at which the emulsion or gelatin dissolves in water on heating the water.
- the temperature of our treatment may be greater or less than 70 C. and may vary from about 40 C. to
- the relative humidity may also vary somewhat within the range of about 50% to 80%, depending upon the amount and nature of the hardening agent used.
- the temperature of treatment is preferably 60 C. to 70 0., and the relative humidity therefor between 50% and 80%.
- the process of hardening gelatino silver halide emulsions and substantially eliminating after-hardening which comprises adding a hardening agent to the emulsion, coating the emulsion on a support and drying it, and subjecting the emulsion to moist incubation at a relative humidity of between 50% and 80% and a temperature of between 40 C. and 90 C. conjointly with ripening, for such length of time as will bring the emulsion to substantially uniform hardness.
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- Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- General Physics & Mathematics (AREA)
- Compositions Of Macromolecular Compounds (AREA)
- Processes Of Treating Macromolecular Substances (AREA)
- Silver Salt Photography Or Processing Solution Therefor (AREA)
- Application Of Or Painting With Fluid Materials (AREA)
- Paints Or Removers (AREA)
Description
atented Dec. 13, 1938 2,139,774 SENSITIZING AND HARDENING PHOTO- PATENT OFFICE GRAPHIC EMULSIONS Samuel E. Sheppard, Robert C. Houck, and Raymond H. Lambert, Rochester, N. Y., assignors,
by mesne assignments,
pany, Jersey City, N. J.,
Jersey to Eastman Kodak Coma corporation of New i No Drawing. Application July 10, 1936 Serial No. 90,000
4 Claims.
This invention relates to finishing photographic emulsions and particularly, to sensitizing and hardening gelatino-silver halide emulsions.
In practice it has been found necessary to treat 5 photographic gelatin or emulsion solutions or layers with a hardening agent in order to increase the resistance of the gelatin or emulsion layer to swelling or softening, particularly when processed at increased temperatures. Compounds which have been used for this purpose are chrome alum, formaldehyde, and other reagents. In application Serial No. 745,754, filed September 27, 1934 in thenames of S. E. Sheppard and R. C. Houck, there is disclosed the use of hydroxy aldehydes up to and including the pentoses for this purpose.
As is well known, a gelatino-silver halide emulsion when first mixed is quite slow or insensitive, and unsatisfactory for making fast negative emulsions. The emulsion mixture is, therefore, digested or ripened in orderto increase the sensitivity. This ripening is ordinarily accomplished by the action of heat or by digestion with ammonia, either alone or in combination with heating. After treatment in this way the emulsion may be jelled and set and then re-melted and coated on the emulsion support. The hardening agent is added at some period subsequent to the digestion, before coating the emulsion on the support.
In many cases the degree of hardening produced in this way, as indicated by the melting point, swelling, behavior on photographic processing and other ways, is not complete after drying the product, but-a greater or lesser amount of so-called after hardening occurs on storage 5 of the plates or films. This may continue through a period of months'and may equal or surpass in degree the initial hardening on first drying. This after hardening, therefore, gives rise to a product whose properties are variable with time unless an inconvenientiy long period of storage prior to use is involved. One consequence of this is generally reduction of speed of development, but other objectionable changes in photographic properties may ensue. A further objection is that it is necessary to repeatedly subject samples of the plates or films to incubation tests in order to ascertain the amount of hardening that has taken place.'
50 It is, therefore, an object of the present invention to provide a means for eliminating after hardening and for producing a more stable emulsion which will show less change in regard to sensitometric and physical properties, such as hardening and swelling, on storage. A further object is to provide a novel method for hardening photographic emulsions. A still further object is to provide a photographic emulsion which will be resistant to relatively high temperatures without objectionable fogging or de-sensitizing. Other objects will appear hereinafter.
We have discovered that with a considerable number of hardening agents the slow process of after hardening may be eliminated and the emulsion brought to a stable condition by heating the coated, dried plates or films, the emulsion of which has been subjected to little or no wet digestion, for a specified time (period of hours only) at specific temperatures and relative humidities. i
Our process of heat accelerated hardening would have only limited application as carried out on emulsions after ordinary finishing, that is, emulsions which had been subjected to digestion or ripening. Since our process is equivalent to a period of incubation under tropical conditions, photographic emulsions prepared in the usual way and subjected to our process would probably, if not certainly, show rapid deterioration, such as fogging, hypersensitization or desensitization, decrease in contrast, etc., on storage.
On the other hand, it is possible to treat a photographic emulsion to moist incubation at specified temperature and relative humidities, according to our invention, and thereby, to produce an emulsion which is fairly stable over a long period of time and which does not exhibit a tendency. to after hardening on storage. This treatment increases the sensitivity of the emulsion, and avoids the necessity of the usual wet digestion.
In accordance with our process a gelatino-silver halide emulsion prepared in the usual way by precipitating a silver halide in the presence of gelatin had added thereto a hardening agent and it is then coated ontoa suitable support at the usual temperature, for example 40 C. and dried in the usual way. The plate or film is then subjected to the heat treatment described below and the combined sensitizing and hardening action performed in this way.
This dry digestion or moist incubation has a number of advantages over the usual wet digestion in which the emulsions are ripened prior to addition of the hardening agent, in that the progress of the hardening is more conveniently controlled and that there is less tendency to increased fogging with increasing sensitization. This is shown by the following tables indicating the speed of plates, subjected to digestion and obtained by moist incubation (for 3.5 hours) was nearly, twice that obtained by wet digestion (at twenty minutes) for a corresponding amount of fog formation.
emulsions at a specified temperature and relative humidity containing. various hardening agents, where the emulsion was not subjected to digestion prior to adding the hardening agent. In each casethe time required to produce a certain melting point has been comparedwith the proper time that would be required to store the emulsion at room temperature in order toreach a melting point of 80 C. to 90 C.
pH6.2-6.7 (except where otherwise; noted).
70 C.60% relative humidity.
P 'ri me oft f ercentea ing a o me of incubation at room Hardening agent gfi ggf gi 3 2252? M l ing 1 1 11 tempere ture to reach gelatin tive hu- 80 midity Hours 0. 0 45 Formaldehyde 10 2 months. 0: 0 e2 0.18 1.0 90 3-4 days. 2. 0 97 0. 0 34 1. 0 34 1 '8 it 0 Months. Arabmose- 4' o 40 5. 5 51 6. 0 64 0.0 sees Z 0 8 22 Months. 3. 0 89 0. 0 e4 Questionable. Several DIBCBtYLL'. 4044 anontbs, perhaps a yea -s1 Acetonyl acetone 4- 2g 4 weeks 23. 0 45-55 0. 0 35-82 Acetonyl acetone 0 3:8 2 34 weeks.
23.0 70 0. 0 55 Acetoxime pH 10.0 aged 10 mos 6.0 m 0 90+ }Quesfionable.
(Very slowly) 'Ierephthalic aldehyde 6- 0 32 Chloral pH 8.0 aged 11 mos 14. 0 2:8 3? (Slowly melting) Methylal pH 8.0 aged 17 mos 14. 0 8:3 1 }Years. Hexamethylene tetramine 1. 0 8:8
a. o 2-8 }e-12 months (estimated). 6.0 g g }e-12 months (estimated).
Wet digestion at 60 C.
Fog 4 min- Time, Speed, H. minutes and D. 3255 Moist incubation at 60 C.
. Fog 4 min- Tune, Speed, H.
utes develophours and D. men;
The following examples illustrate the increased 7 hardening achieved by heating gelatin or gelatin By melting point is meant the temperature at which the emulsion or gelatin dissolves in water on heating the water.
In the above examples we have referred to the use of a pI-l of 6.2 to 6.7 with a temperature of 70 C. and relative humidity of 60%. These limits are for the purposes of example only and-do not exhaust the possibilities of our invention. It
. is known that during digestion of a photographic emulsion the sensitivity varies with the pH but there are practical pH limits above. which it is not desirable to go. In a similar manner the temperature of our treatment may be greater or less than 70 C. and may vary from about 40 C. to
90 C. The relative humidity may also vary somewhat within the range of about 50% to 80%, depending upon the amount and nature of the hardening agent used.
Where the emulsion is subjected to moist incubation without the usual wet digestion, before or after coating it on the support, the temperature of treatment is preferably 60 C. to 70 0., and the relative humidity therefor between 50% and 80%.
Efiect of heat on hardening of gelatin emulsion by various hardening agents 10 Although we have disclosed the use of a number of hardening agents together with a preferred method of carrying out our invention it is to be understood that we are not limited to the compounds and methods of procedure described herein, but that our invention is limited only by the scope of the appended claims.
What we claim is:
1. The process of hardening gelatino silver halide emulsions and substantially eliminating after-hardening, which comprises adding a hardening agent to the emulsion, coating the emulsion on a support and drying it, and subjecting the emulsion to moist incubation at a relative humidity of between 50% and 80% and a temperature of between 40 C. and 90 C. conjointly with ripening, for such length of time as will bring the emulsion to substantially uniform hardness.
2. The process of sensitizing and. hardening photographic emulsions which comprises precipitating a silver halide in the presence of gelatin to form an emulsion, adding a hardening agent to the emulsion, coating the emulsion on a support, drying and then subjecting the emulsion to moist incubation at a relative humidity between about and about 80%, and a. temperature of about C. to C. for such length of time as will bring the emulsion to substantially uniform hardness.
3. The process of sensitizing and hardening photographic emulsions which comprises precipitating a silver halide in the presence of gelatin to form an emulsion, adding a hardening agent to the emulsion, coating the emulsion on a support, drying and then subjecting the emulsion to incubation in air at about 60% relative humidity and 60 C. to 70 C. for such length of time as will bring the emulsion to substantially uniform hardness.
4. The process of sensitizing and hardening photographic emulsions which comprises precipiq tating a silver halidein the presence of gelatin to form an emulsion, adding a hardening agent to the emulsion, coating the emulsion on a support, drying and then subjecting the emulsion to incubation in air at 50% to relative humidity and 60 C. to 70 C. for such length of time as will bring'the emulsion to substantially uniform hardness. 4
SAMUEL E. SHEPPARD. ROBERT C. HOUCK. RAYMOND H. LAMBERT.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US90000A US2139774A (en) | 1936-07-10 | 1936-07-10 | Sensitizing and hardening photographic emulsions |
| FR824219D FR824219A (en) | 1936-07-10 | 1937-07-10 | Improvements to photographic emulsions |
| GB19172/37A GB479419A (en) | 1936-07-10 | 1937-07-10 | Improvements in ripening and hardening photographic emulsions |
| DE1937K0147221 DE696896C (en) | 1936-07-10 | 1937-07-10 | silver halide graphic gelatin emulsions |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US90000A US2139774A (en) | 1936-07-10 | 1936-07-10 | Sensitizing and hardening photographic emulsions |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2139774A true US2139774A (en) | 1938-12-13 |
Family
ID=22220603
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US90000A Expired - Lifetime US2139774A (en) | 1936-07-10 | 1936-07-10 | Sensitizing and hardening photographic emulsions |
Country Status (4)
| Country | Link |
|---|---|
| US (1) | US2139774A (en) |
| DE (1) | DE696896C (en) |
| FR (1) | FR824219A (en) |
| GB (1) | GB479419A (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2441440A (en) * | 1945-01-25 | 1948-05-11 | Du Pont | Silver halide photographic emulsions of enhanced light sensitivity |
| US2493838A (en) * | 1945-07-19 | 1950-01-10 | Bennett F Terry | Photoprinting processes |
| US2614928A (en) * | 1947-08-13 | 1952-10-21 | Eastman Kodak Co | Method of preparing photographic emulsions |
| US2614931A (en) * | 1947-08-13 | 1952-10-21 | Eastman Kodak Co | Method of preparing cellulose ester-silver-halide photographic emulsions |
| US2614930A (en) * | 1947-08-13 | 1952-10-21 | Eastman Kodak Co | Method of preparing polyvinyl alcohol-silver halide photographic emulsions |
| US2728662A (en) * | 1947-08-13 | 1955-12-27 | Eastman Kodak Co | Method of preparing photographic emulsions |
| US3047394A (en) * | 1958-08-01 | 1962-07-31 | Eastman Kodak Co | Photosensitive products containing therein layers hardened by bisepoxides |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2640752A (en) * | 1949-11-30 | 1953-06-02 | Ethicon Suture Lab Inc | Process of making sutures |
| US2938763A (en) * | 1956-02-20 | 1960-05-31 | Jr Edward H Harris | Tanning with acetonylacetone |
-
1936
- 1936-07-10 US US90000A patent/US2139774A/en not_active Expired - Lifetime
-
1937
- 1937-07-10 FR FR824219D patent/FR824219A/en not_active Expired
- 1937-07-10 DE DE1937K0147221 patent/DE696896C/en not_active Expired
- 1937-07-10 GB GB19172/37A patent/GB479419A/en not_active Expired
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2441440A (en) * | 1945-01-25 | 1948-05-11 | Du Pont | Silver halide photographic emulsions of enhanced light sensitivity |
| US2493838A (en) * | 1945-07-19 | 1950-01-10 | Bennett F Terry | Photoprinting processes |
| US2614928A (en) * | 1947-08-13 | 1952-10-21 | Eastman Kodak Co | Method of preparing photographic emulsions |
| US2614931A (en) * | 1947-08-13 | 1952-10-21 | Eastman Kodak Co | Method of preparing cellulose ester-silver-halide photographic emulsions |
| US2614929A (en) * | 1947-08-13 | 1952-10-21 | Eastman Kodak Co | Method of preparing photographic emulsions |
| US2614930A (en) * | 1947-08-13 | 1952-10-21 | Eastman Kodak Co | Method of preparing polyvinyl alcohol-silver halide photographic emulsions |
| US2728662A (en) * | 1947-08-13 | 1955-12-27 | Eastman Kodak Co | Method of preparing photographic emulsions |
| US3047394A (en) * | 1958-08-01 | 1962-07-31 | Eastman Kodak Co | Photosensitive products containing therein layers hardened by bisepoxides |
Also Published As
| Publication number | Publication date |
|---|---|
| FR824219A (en) | 1938-02-04 |
| DE696896C (en) | 1940-10-02 |
| GB479419A (en) | 1938-02-04 |
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