DE1096193B - Process for the production of antihalation and filter layers for reversal development - Google Patents
Process for the production of antihalation and filter layers for reversal developmentInfo
- Publication number
- DE1096193B DE1096193B DEP21443A DEP0021443A DE1096193B DE 1096193 B DE1096193 B DE 1096193B DE P21443 A DEP21443 A DE P21443A DE P0021443 A DEP0021443 A DE P0021443A DE 1096193 B DE1096193 B DE 1096193B
- Authority
- DE
- Germany
- Prior art keywords
- silver
- antihalation
- production
- layers
- 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.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims description 10
- 238000004519 manufacturing process Methods 0.000 title claims description 5
- 229920000159 gelatin Polymers 0.000 claims description 10
- 235000019322 gelatine Nutrition 0.000 claims description 10
- 229910052709 silver Inorganic materials 0.000 claims description 10
- 239000004332 silver Substances 0.000 claims description 10
- 108010010803 Gelatin Proteins 0.000 claims description 8
- 239000008273 gelatin Substances 0.000 claims description 8
- 235000011852 gelatine desserts Nutrition 0.000 claims description 8
- 239000000084 colloidal system Substances 0.000 claims description 7
- 230000001681 protective effect Effects 0.000 claims description 7
- 239000000725 suspension Substances 0.000 claims description 6
- OAKJQQAXSVQMHS-UHFFFAOYSA-N Hydrazine Chemical compound NN OAKJQQAXSVQMHS-UHFFFAOYSA-N 0.000 claims description 4
- ADZWSOLPGZMUMY-UHFFFAOYSA-M silver bromide Chemical compound [Ag]Br ADZWSOLPGZMUMY-UHFFFAOYSA-M 0.000 claims description 3
- 239000007795 chemical reaction product Substances 0.000 claims description 2
- 150000002429 hydrazines Chemical class 0.000 claims description 2
- 150000002894 organic compounds Chemical class 0.000 claims description 2
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 claims 1
- NGDDCFINDCHPTF-UHFFFAOYSA-N [Br].[Ag] Chemical compound [Br].[Ag] NGDDCFINDCHPTF-UHFFFAOYSA-N 0.000 claims 1
- ZYDVNTYVDVZMKF-UHFFFAOYSA-N [Cl].[Ag] Chemical compound [Cl].[Ag] ZYDVNTYVDVZMKF-UHFFFAOYSA-N 0.000 claims 1
- 239000002253 acid Substances 0.000 claims 1
- 150000008065 acid anhydrides Chemical class 0.000 claims 1
- 239000012670 alkaline solution Substances 0.000 claims 1
- 229910052801 chlorine Inorganic materials 0.000 claims 1
- 239000000460 chlorine Substances 0.000 claims 1
- 150000001805 chlorine compounds Chemical class 0.000 claims 1
- 238000011946 reduction process Methods 0.000 claims 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 8
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 6
- 230000005540 biological transmission Effects 0.000 description 4
- 238000010521 absorption reaction Methods 0.000 description 3
- 239000000654 additive Substances 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 2
- 239000001828 Gelatine Substances 0.000 description 2
- 229910021607 Silver chloride Inorganic materials 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- HKZLPVFGJNLROG-UHFFFAOYSA-M silver monochloride Chemical compound [Cl-].[Ag+] HKZLPVFGJNLROG-UHFFFAOYSA-M 0.000 description 2
- SQGYOTSLMSWVJD-UHFFFAOYSA-N silver(1+) nitrate Chemical compound [Ag+].[O-]N(=O)=O SQGYOTSLMSWVJD-UHFFFAOYSA-N 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- GGZHVNZHFYCSEV-UHFFFAOYSA-N 1-Phenyl-5-mercaptotetrazole Chemical compound SC1=NN=NN1C1=CC=CC=C1 GGZHVNZHFYCSEV-UHFFFAOYSA-N 0.000 description 1
- FUSNOPLQVRUIIM-UHFFFAOYSA-N 4-amino-2-(4,4-dimethyl-2-oxoimidazolidin-1-yl)-n-[3-(trifluoromethyl)phenyl]pyrimidine-5-carboxamide Chemical compound O=C1NC(C)(C)CN1C(N=C1N)=NC=C1C(=O)NC1=CC=CC(C(F)(F)F)=C1 FUSNOPLQVRUIIM-UHFFFAOYSA-N 0.000 description 1
- QAZFSCRQNWGQDE-UHFFFAOYSA-N 5,5-dimethyl-2-sulfanylidene-1,3-thiazolidin-4-one Chemical compound CC1(C)SC(=S)NC1=O QAZFSCRQNWGQDE-UHFFFAOYSA-N 0.000 description 1
- -1 Benzylidene rhodanine Chemical compound 0.000 description 1
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 1
- 239000005977 Ethylene Substances 0.000 description 1
- CPELXLSAUQHCOX-UHFFFAOYSA-N Hydrogen bromide Chemical compound Br CPELXLSAUQHCOX-UHFFFAOYSA-N 0.000 description 1
- LGRFSURHDFAFJT-UHFFFAOYSA-N Phthalic anhydride Natural products C1=CC=C2C(=O)OC(=O)C2=C1 LGRFSURHDFAFJT-UHFFFAOYSA-N 0.000 description 1
- 230000001746 atrial effect Effects 0.000 description 1
- PASDCCFISLVPSO-UHFFFAOYSA-N benzoyl chloride Chemical compound ClC(=O)C1=CC=CC=C1 PASDCCFISLVPSO-UHFFFAOYSA-N 0.000 description 1
- JHIWVOJDXOSYLW-UHFFFAOYSA-N butyl 2,2-difluorocyclopropane-1-carboxylate Chemical compound CCCCOC(=O)C1CC1(F)F JHIWVOJDXOSYLW-UHFFFAOYSA-N 0.000 description 1
- 229920002301 cellulose acetate Polymers 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 230000001627 detrimental effect Effects 0.000 description 1
- 238000007865 diluting Methods 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 239000000839 emulsion Substances 0.000 description 1
- 229910052736 halogen Inorganic materials 0.000 description 1
- 150000002367 halogens Chemical class 0.000 description 1
- 239000012493 hydrazine sulfate Substances 0.000 description 1
- 229910000377 hydrazine sulfate Inorganic materials 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 235000012149 noodles Nutrition 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 229910001961 silver nitrate Inorganic materials 0.000 description 1
- GGCZERPQGJTIQP-UHFFFAOYSA-N sodium;9,10-dioxoanthracene-2-sulfonic acid Chemical compound [Na+].C1=CC=C2C(=O)C3=CC(S(=O)(=O)O)=CC=C3C(=O)C2=C1 GGCZERPQGJTIQP-UHFFFAOYSA-N 0.000 description 1
- 230000003595 spectral effect Effects 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000001429 visible spectrum Methods 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
- G03C1/76—Photosensitive materials characterised by the base or auxiliary layers
- G03C1/825—Photosensitive materials characterised by the base or auxiliary layers characterised by antireflection means or visible-light filtering means, e.g. antihalation
- G03C1/8255—Silver or silver compounds therefor
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
Description
DEUTSCHESGERMAN
Aus der Praxis, der Literatur und aus Patentschriften sind zahlreiche Verfahren zur Herstellung von hochdispersen Suspensionen von metallischem Silber in Gelatine bekanntgeworden, die bei entsprechender Weiterverarbeitung zur Herstellung von Lichthofschutzschichten für solche photographische Filme verwendet werden, die einer Umkehrentwicklung unterzogen werden. Nach diesen bekannten Verfahren hergestellte Lichthofschutzschichten weisen im allgemeinen eine selektive Lichtdurchlässigkeit für bestimmte Bereiche des sichtbaren Spektrums auf. In den Bereichen erhöhter Lichtdurchlässigkeit ist daher auch die Lichthofschutzwirkung relativ geringer. Dieser Umstand wirkt sich besonders nachteilig aus, wenn man solche Schichten als Lichthofschutz für panchromatisch sensibilisierte Emulsionen verwenden will.There are numerous processes for the production of highly dispersed suspensions of metallic silver in gelatine from practice, the literature and from patents became known that with appropriate further processing for the production of antihalation layers can be used for those photographic films which are subjected to reversal development. To Antihalation layers produced by these known processes generally have selective light transmission for certain areas of the visible spectrum. In the areas of increased light transmission therefore the antihalation effect is also relatively lower. This fact is particularly detrimental if you use such layers as antihalation protection for panchromatically sensitized emulsions want.
Die vorliegende Erfindung befaßt sich mit der Aufgabe, hochdisperse Suspensionen von Silber in Schutzkolloiden herzustellen, die Lichthofschutzschichten mit einer für alle Wellenlängen möglichst gleich geringen Lichtdurchlässigkeit ergeben. Solche Lichthofschutzschichten sehen in der Durchsicht neutralgrau aus.The present invention is concerned with the problem of highly dispersed suspensions of silver in protective colloids to produce the antihalation layers with a light transmission that is as low as possible for all wavelengths result. Such antihalation layers look neutral gray when viewed through.
Die Aufgabe wird erfindungsgemäß dadurch gelöst, daß man hochdisperse Suspensionen von Chlorsilber oder Bromsilber in Gelatine oder einem ähnlichen Schutzkolloid bei pH-Werten über 8 mit Hydrazin oder Hydrazinderivaten reduziert und diese Reduktion in Gegenwart von organischen Verbindungen durchführt, die bei der gewöhnlichen Entwicklung belichteter Chlorsilber- oder Bromsilberschichten ein blauschwarzgetöntes Silber liefern. Stoffe dieser Art sind als Blauschwarzkörper bekannt und in der Literatur sowie in Patentschriften wiederholt beschrieben worden. Für das erfindungsgemäße Verfahren geeignete Blauschwarzkörper sind u. a.:The object is inventively achieved in that one highly dispersed suspensions of silver chloride or silver bromide in gelatin or a similar protective colloid at pH values above 8 is reduced with hydrazine or hydrazine derivatives and performs this reduction in the presence of organic compounds which are exposed in the ordinary development silver chloride - or bromide silver layers produce a blue-black tinted silver. Substances of this type are known as blue-black bodies and have been repeatedly described in the literature and in patents. Blue-black bodies suitable for the process according to the invention include:
Phenylmerkaptotetrazol(USA.-Patentschrift
2 403 927);Phenylmercaptotetrazole (U.S. Patent
2,403,927);
Benzylidenrhodanin (Phot. Korr., 1937 [Beil. 1], 1938, S. 84);Benzylidene rhodanine (Phot. Korr., 1937 [Beil. 1], 1938, p. 84);
Dimethyl-oxothion-tetrahydrothiazin (britische Patentschrift 644 788);Dimethyl-oxothione-tetrahydrothiazine (British patent specification 644 788);
5,5-Dimethylrhodanin (Phot. Korr., 1937 [Beil. 1], 1938, S. 84);5,5-dimethylrhodanine (Phot. Korr., 1937 [Beil. 1], 1938, p. 84);
2-Imino-5-thiourazol (USA.-Patentschrift 2 590 775);2-imino-5-thiourazole (U.S. Patent 2,590,775);
Äthylen-bis-(2-imino-5-thiourazol)-hydrobromid
(französische Patentschrift 964 821).Ethylene bis (2-imino-5-thiourazole) hydrobromide
(French patent specification 964 821).
Verfahren zur HerstellungMethod of manufacture
von Lichthofschutz- und Filterschichtenof antihalation and filter layers
für Umkehrentwicklungfor reversal development
Anmelder:Applicant:
Perutz Photowerke G.m.b.H.,
München 25, Kistlerhofstr. 75/82Perutz Photowerke GmbH,
Munich 25, Kistlerhofstr. 75/82
Dr.-Ing. Heinrich Socher, München-Solln,Dr.-Ing. Heinrich Socher, Munich-Solln,
und Dr.-Ing. Ernst Proeschl, München,and Dr.-Ing. Ernst Proeschl, Munich,
sind als Erfinder genannt wordenhave been named as inventors
vor Zugabe des Reduktionsmittels zugesetzt. Je nach der so spezifischen Wirksamkeit der Zusätze muß man dem Reduktionsgemisch verschiedene Mengen an Blauschwarzkörpern hinzufügen. Im allgemeinen bewegen sich die Mengen in der Größenordnung von 10 bis 500 mg auf 100 mMol Silbersalz. Die optimale Menge kann durch einfaches Probieren gefunden werden.added before adding the reducing agent. Depending on the specific effectiveness of the additives, you have to Add various amounts of blue-black bodies to the reduction mixture. In general, they move Amounts on the order of 10 to 500 mg per 100 mmol of silver salt. The optimal amount can go through easy trying can be found.
Man vermischt bei 40° C 1200 ecm einer 2°/0igen Gelatinelösung mit 660 ecm einer 0,5 η-Kochsalzlösung und läßt dazu unter starkem Rühren 600 ecm einer 0,5 n-Silbernitratlösung von 350C zufließen. Unmittelbar anschließend wird ein Blauschwarzkörper, z. B. 400 mg 2-Imino-5-thiourazol, in Alkohol gelöst, hinzugegeben und 10 Minuten bei 40°C digeriert. Dann fügt man eine Lösung von 16 g Hydrazinsulf at, 60 ecm Wasser und 46 ecm 3 η-Natronlauge unter langsamem Rühren hinzu und gibt zum Schluß 150 ecm 3 η-Natronlauge hinzu. Nach beendigter Reduktion löst man in dem Gemisch so viel trockene Gelatine auf, daß die Lösung etwa 8% Gelatine enthält, und neutralisiert mit 3 n-Schwefelsäure. Das Gemisch wird zum Erstarren gebracht, in Nudeln gepreßt und gründlich ausgewaschen, Nach dem Wiederaufschmelzen kann man die Lösung nach Zugabe der üblichen Gießzusätze direkt vergießen oder durch Verdünnen so abstimmen, daß nach dem Vergießen eine ganz bestimmte Dichte erreicht wird.Is mixed at 40 ° C 1200 cc of a 2 ° / 0 gelatin solution containing 660 cc of a 0.5 η-saline solution and allowed to vigorous stirring 600 cc of a 0.5 N silver nitrate solution of 35 0 C accrue. Immediately thereafter, a blue-black body, e.g. B. 400 mg of 2-imino-5-thiourazole, dissolved in alcohol, added and digested at 40 ° C. for 10 minutes. A solution of 16 g of hydrazine sulfate, 60 ecm of water and 46 ecm 3 of η sodium hydroxide solution is then added with slow stirring and finally 150 ecm 3 of η sodium hydroxide solution is added. When the reduction is complete, so much dry gelatin is dissolved in the mixture that the solution contains about 8% gelatin, and it is neutralized with 3N sulfuric acid. The mixture is made to solidify, pressed into noodles and thoroughly washed out. After remelting, the solution can be poured directly after adding the usual pouring additives or by diluting it so that a certain density is achieved after pouring.
Das Verfahren ist nicht auf die angeführten Beispiele beschränkt, sondern ist mit gleichem Ergebnis bei allen anderen wirkungsgleichen Blauschwarzkörpern durchfahrbar. The procedure is not limited to the examples given, but has the same result for all of them other blue-black bodies with the same effect can be passed through.
Diese Zusätze werden entweder in Wasser oder in Alkohol oder sonstigen mit Wasser mischbaren organischen Lösungsmitteln gelöst und der HalogensilberdispersionThese additives are either in water or in alcohol or other water-miscible organic Solvents and the halogen silver dispersion
Eine nach dem Beispiel 1 hergestellte Suspension von metallischem Silber wird in einer Stärke von 2 μ. auf eine Celluloseacetatunterlage vergossen und mit Hilfe eines Zeiss-Spektraldensitometers die Absorption zwischen 435 und 700 ηιμ ausgemessen (Kurve I). Als Vergleich dient eine gleichfalls durch Reduktion hergestellte Silber-A suspension of metallic silver prepared according to Example 1 is 2 μ thick. on a Cellulose acetate base potted and with the help of a Zeiss spectral densitometer the absorption between 435 and 700 ηιμ measured (curve I). As comparison a silver, also produced by reduction, serves
009 680/443009 680/443
schicht ohne Blauschwarzkörper (Kurve II). Aus Kurve I geht hervor, daß die Dichte der erfindungsgemäßen Schicht zwischen 700 und 590 ηιμ einen konstanten Wert von 1,7 aufweist, der nach dem kurzwelligeren Teil einen Endwert von 2,0 bei 450 πιμ erreicht. Bei der Vergleichsprobe (Kurve II), deren Schichtdicke 4 μ beträgt, hingegen zeigt sich im langwelligen Teil des Spektrums eine erhöhte Lichtdurchlässigkeit, die für den ungenügenden Lichthofschutz für panchromatisch sensibilisierte Schichten verantwortlich ist. Aus Kurve I geht ferner hervor, daß eine nach dem Verfahren hergestellte Silberschicht nicht nur eine gleichmäßige Absorption über den gesamten Wellenlängenbereich aufweist, sondern auch trotz der Verringerung der Schichtdicke um die Hälfte eine im Mittel um die Dichte 1 höhere Absorption gegenüber den Silberschichten ohne Blauschwarzkörper.layer without blue-black body (curve II). From curve I it can be seen that the density of the layer according to the invention between 700 and 590 ηιμ a constant value of 1.7 has, which reaches a final value of 2.0 at 450 πιμ after the shorter-wave part. With the comparison sample (Curve II), the layer thickness of which is 4 μ, on the other hand, there is an increased in the long-wave part of the spectrum Light transmission, which is responsible for the insufficient atrial protection for panchromatically sensitized layers is. From curve I it can also be seen that a silver layer produced by the method is not only has a uniform absorption over the entire wavelength range, but also in spite of the reduction the layer thickness by half an average density 1 higher absorption compared to the silver layers without blue-black body.
Bei der Herstellung der erfindungsgemäßen Schichten kann man an Stelle von Gelatine als Schutzkolloid auch Gelatinederivate verwenden, z. B. das Umsetzungsprodukt von Gelatine mit Phthalsäureanhydrid oder Benzoylchlorid. When producing the layers according to the invention, gelatine can also be used as a protective colloid Use gelatin derivatives, e.g. B. the reaction product of gelatin with phthalic anhydride or benzoyl chloride.
Claims (3)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP21443A DE1096193B (en) | 1958-09-30 | 1958-09-30 | Process for the production of antihalation and filter layers for reversal development |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP21443A DE1096193B (en) | 1958-09-30 | 1958-09-30 | Process for the production of antihalation and filter layers for reversal development |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| DE1096193B true DE1096193B (en) | 1960-12-29 |
Family
ID=7368252
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| DEP21443A Pending DE1096193B (en) | 1958-09-30 | 1958-09-30 | Process for the production of antihalation and filter layers for reversal development |
Country Status (1)
| Country | Link |
|---|---|
| DE (1) | DE1096193B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2337352A1 (en) * | 1975-12-30 | 1977-07-29 | Agfa Gevaert Ag | PROCESS FOR THE PREPARATION OF SILVER DISPERSIONS FOR FILTER LAYERS AND ANTIHALO LAYERS |
| JPS536636B1 (en) * | 1969-10-27 | 1978-03-09 | ||
| EP0563985A1 (en) | 1992-04-03 | 1993-10-06 | Fuji Photo Film Co., Ltd. | Silver halide color photographic material |
-
1958
- 1958-09-30 DE DEP21443A patent/DE1096193B/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS536636B1 (en) * | 1969-10-27 | 1978-03-09 | ||
| FR2337352A1 (en) * | 1975-12-30 | 1977-07-29 | Agfa Gevaert Ag | PROCESS FOR THE PREPARATION OF SILVER DISPERSIONS FOR FILTER LAYERS AND ANTIHALO LAYERS |
| EP0563985A1 (en) | 1992-04-03 | 1993-10-06 | Fuji Photo Film Co., Ltd. | Silver halide color photographic material |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| DE736554C (en) | Process for making highly sensitive photographic emulsions | |
| DE2700651A1 (en) | PHOTOGRAPHIC SILVER HALOGENIDE MATERIALS WITH LIGHT-ABSORBING COLORS | |
| DE1547819C3 (en) | Process for the preparation of dispersions of black colloidal silver | |
| DE1096193B (en) | Process for the production of antihalation and filter layers for reversal development | |
| DE2228543C3 (en) | Process for incorporating additives into a mixture intended for the manufacture of silver halide recording materials | |
| DE1809214A1 (en) | Process for the preparation of a black dispersion of silver in gelatin | |
| DE1173338B (en) | Silver salt photographic diffusion transfer process | |
| DE859711C (en) | Process for the direct production of positive photographic images | |
| DE1547902A1 (en) | Photosensitive photographic preparation | |
| DE1162689B (en) | Process for the preparation of light-sensitive photographic emulsions | |
| DE3017503A1 (en) | METHOD FOR TRAINING A PHOTOGRAPHIC IMAGE | |
| DE944232C (en) | Process for producing colored images | |
| DE811313C (en) | Process for the production of colloidal silver | |
| DE156345C (en) | ||
| DE2337172A1 (en) | PROCESS FOR THE MANUFACTURING OF PHOTOGRAPHIC GELATIN SILVER HALOGENIDE EMULSIONS | |
| DE2131455C3 (en) | Process for preparing a gelatin-silver halide emulsion | |
| DE966018C (en) | Process for preparing a photographic emulsion | |
| DE1597488A1 (en) | Improved photographic emulsion for the production of direct positive images | |
| DE937867C (en) | Process for the production of photographic layers | |
| DE3130345A1 (en) | METHOD FOR CONCENTRATING YELLOW SILVER SOLE | |
| DE1291997B (en) | Process for the production of stable dispersions of silver precipitating, metal sulfide or metal selenide containing germs for the silver salt diffusion process | |
| DE1045228B (en) | Process for the preparation of silver halide photographic emulsions | |
| DE1234031B (en) | Process for the preparation of dispersions of colloidal silver | |
| DE1008572B (en) | Mixtures of substances for the production of light-sensitive photographic layers | |
| DE1073305B (en) | Process for hardening a gelatinous composition applied as a layer to photographic material |