US2604400A - Naphthyl hydrazine sulfonic acids in direct positive photographic processes - Google Patents
Naphthyl hydrazine sulfonic acids in direct positive photographic processes Download PDFInfo
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- US2604400A US2604400A US218072A US21807251A US2604400A US 2604400 A US2604400 A US 2604400A US 218072 A US218072 A US 218072A US 21807251 A US21807251 A US 21807251A US 2604400 A US2604400 A US 2604400A
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- emulsion
- water
- naphthyl
- parts
- direct positive
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- 238000000034 method Methods 0.000 title claims description 15
- 239000002253 acid Substances 0.000 title description 16
- XBCIOBSQHJYVBQ-UHFFFAOYSA-N naphthalen-1-ylhydrazine Chemical compound C1=CC=C2C(NN)=CC=CC2=C1 XBCIOBSQHJYVBQ-UHFFFAOYSA-N 0.000 title description 8
- 239000000839 emulsion Substances 0.000 claims description 58
- 229910052709 silver Inorganic materials 0.000 claims description 23
- 239000004332 silver Substances 0.000 claims description 23
- -1 SILVER HALIDE Chemical class 0.000 claims description 21
- 238000011161 development Methods 0.000 claims description 8
- 238000012360 testing method Methods 0.000 claims description 7
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 33
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 32
- QIGBRXMKCJKVMJ-UHFFFAOYSA-N Hydroquinone Chemical compound OC1=CC=C(O)C=C1 QIGBRXMKCJKVMJ-UHFFFAOYSA-N 0.000 description 18
- IOLCXVTUBQKXJR-UHFFFAOYSA-M potassium bromide Chemical compound [K+].[Br-] IOLCXVTUBQKXJR-UHFFFAOYSA-M 0.000 description 14
- GEHJYWRUCIMESM-UHFFFAOYSA-L sodium sulfite Chemical compound [Na+].[Na+].[O-]S([O-])=O GEHJYWRUCIMESM-UHFFFAOYSA-L 0.000 description 12
- OAKJQQAXSVQMHS-UHFFFAOYSA-N Hydrazine Chemical compound NN OAKJQQAXSVQMHS-UHFFFAOYSA-N 0.000 description 10
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 10
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 8
- 239000000203 mixture Substances 0.000 description 8
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 6
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 5
- 150000004820 halides Chemical class 0.000 description 5
- 150000003839 salts Chemical class 0.000 description 5
- 229910000029 sodium carbonate Inorganic materials 0.000 description 5
- CYXJEHCKVOQFOV-UHFFFAOYSA-N (4-amino-2-methylphenyl) hydrogen sulfate Chemical compound CC1=CC(N)=CC=C1OS(O)(=O)=O CYXJEHCKVOQFOV-UHFFFAOYSA-N 0.000 description 4
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 4
- CPELXLSAUQHCOX-UHFFFAOYSA-M Bromide Chemical compound [Br-] CPELXLSAUQHCOX-UHFFFAOYSA-M 0.000 description 4
- 229940101006 anhydrous sodium sulfite Drugs 0.000 description 4
- YCIMNLLNPGFGHC-UHFFFAOYSA-N catechol Chemical compound OC1=CC=CC=C1O YCIMNLLNPGFGHC-UHFFFAOYSA-N 0.000 description 4
- 235000015424 sodium Nutrition 0.000 description 4
- LPXPTNMVRIOKMN-UHFFFAOYSA-M sodium nitrite Chemical compound [Na+].[O-]N=O LPXPTNMVRIOKMN-UHFFFAOYSA-M 0.000 description 4
- 229940001482 sodium sulfite Drugs 0.000 description 4
- 235000010265 sodium sulphite Nutrition 0.000 description 4
- LRUDIIUSNGCQKF-UHFFFAOYSA-N 5-methyl-1H-benzotriazole Chemical compound C1=C(C)C=CC2=NNN=C21 LRUDIIUSNGCQKF-UHFFFAOYSA-N 0.000 description 3
- WFDIJRYMOXRFFG-UHFFFAOYSA-N Acetic anhydride Chemical compound CC(=O)OC(C)=O WFDIJRYMOXRFFG-UHFFFAOYSA-N 0.000 description 3
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 3
- VMHLLURERBWHNL-UHFFFAOYSA-M Sodium acetate Chemical compound [Na+].CC([O-])=O VMHLLURERBWHNL-UHFFFAOYSA-M 0.000 description 3
- 238000005273 aeration Methods 0.000 description 3
- 150000001875 compounds Chemical class 0.000 description 3
- 239000000975 dye Substances 0.000 description 3
- 229920000159 gelatin Polymers 0.000 description 3
- 235000019322 gelatine Nutrition 0.000 description 3
- XMBWDFGMSWQBCA-UHFFFAOYSA-N hydrogen iodide Chemical compound I XMBWDFGMSWQBCA-UHFFFAOYSA-N 0.000 description 3
- 125000001624 naphthyl group Chemical group 0.000 description 3
- NLKNQRATVPKPDG-UHFFFAOYSA-M potassium iodide Chemical compound [K+].[I-] NLKNQRATVPKPDG-UHFFFAOYSA-M 0.000 description 3
- 229910052708 sodium Inorganic materials 0.000 description 3
- 239000011734 sodium Substances 0.000 description 3
- 239000001632 sodium acetate Substances 0.000 description 3
- 235000017281 sodium acetate Nutrition 0.000 description 3
- AZQWKYJCGOJGHM-UHFFFAOYSA-N 1,4-benzoquinone Chemical compound O=C1C=CC(=O)C=C1 AZQWKYJCGOJGHM-UHFFFAOYSA-N 0.000 description 2
- JKFYKCYQEWQPTM-UHFFFAOYSA-N 2-azaniumyl-2-(4-fluorophenyl)acetate Chemical compound OC(=O)C(N)C1=CC=C(F)C=C1 JKFYKCYQEWQPTM-UHFFFAOYSA-N 0.000 description 2
- LJCWONGJFPCTTL-UHFFFAOYSA-N 4-hydroxyphenylglycine Chemical compound OC(=O)C(N)C1=CC=C(O)C=C1 LJCWONGJFPCTTL-UHFFFAOYSA-N 0.000 description 2
- ZVNPWFOVUDMGRP-UHFFFAOYSA-N 4-methylaminophenol sulfate Chemical compound OS(O)(=O)=O.CNC1=CC=C(O)C=C1.CNC1=CC=C(O)C=C1 ZVNPWFOVUDMGRP-UHFFFAOYSA-N 0.000 description 2
- WKBOTKDWSSQWDR-UHFFFAOYSA-N Bromine atom Chemical compound [Br] WKBOTKDWSSQWDR-UHFFFAOYSA-N 0.000 description 2
- 238000007362 Burton trifluoromethylation reaction Methods 0.000 description 2
- 239000001828 Gelatine Substances 0.000 description 2
- 229910021612 Silver iodide Inorganic materials 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- LSNNMFCWUKXFEE-UHFFFAOYSA-N Sulfurous acid Chemical compound OS(O)=O LSNNMFCWUKXFEE-UHFFFAOYSA-N 0.000 description 2
- RAHZWNYVWXNFOC-UHFFFAOYSA-N Sulphur dioxide Chemical compound O=S=O RAHZWNYVWXNFOC-UHFFFAOYSA-N 0.000 description 2
- 229960000583 acetic acid Drugs 0.000 description 2
- ZMJZYXKPJWGDGR-UHFFFAOYSA-N aminosulfamic acid Chemical compound NNS(O)(=O)=O ZMJZYXKPJWGDGR-UHFFFAOYSA-N 0.000 description 2
- 229910021529 ammonia Inorganic materials 0.000 description 2
- GDTBXPJZTBHREO-UHFFFAOYSA-N bromine Substances BrBr GDTBXPJZTBHREO-UHFFFAOYSA-N 0.000 description 2
- 229910052794 bromium Inorganic materials 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 239000012954 diazonium Substances 0.000 description 2
- 150000001989 diazonium salts Chemical class 0.000 description 2
- NSNHWTBQMQIDCF-UHFFFAOYSA-N dihydrate;hydrochloride Chemical compound O.O.Cl NSNHWTBQMQIDCF-UHFFFAOYSA-N 0.000 description 2
- MCYYJHPHBOPLMH-UHFFFAOYSA-L disodium;dioxido-oxo-sulfanylidene-$l^{6}-sulfane;hydrate Chemical compound O.[Na+].[Na+].[O-]S([O-])(=O)=S MCYYJHPHBOPLMH-UHFFFAOYSA-L 0.000 description 2
- 239000000706 filtrate Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- 239000007800 oxidant agent Substances 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- WQGWDDDVZFFDIG-UHFFFAOYSA-N pyrogallol Chemical compound OC1=CC=CC(O)=C1O WQGWDDDVZFFDIG-UHFFFAOYSA-N 0.000 description 2
- 229940045105 silver iodide Drugs 0.000 description 2
- 235000010288 sodium nitrite Nutrition 0.000 description 2
- 159000000000 sodium salts Chemical class 0.000 description 2
- AKHNMLFCWUSKQB-UHFFFAOYSA-L sodium thiosulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=S AKHNMLFCWUSKQB-UHFFFAOYSA-L 0.000 description 2
- 235000019345 sodium thiosulphate Nutrition 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N sulfuric acid Substances OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- AFXIMOINFOVAPV-UHFFFAOYSA-N (4-amino-2-methylphenyl) hydrogen sulfate benzene-1,4-diol Chemical compound C1(O)=CC=C(O)C=C1.S(=O)(=O)(O)OC1=C(C=C(C=C1)N)C AFXIMOINFOVAPV-UHFFFAOYSA-N 0.000 description 1
- GZPWPJCVHJJOEV-UHFFFAOYSA-N (4-bromonaphthalen-1-yl)hydrazine Chemical compound C1=CC=C2C(NN)=CC=C(Br)C2=C1 GZPWPJCVHJJOEV-UHFFFAOYSA-N 0.000 description 1
- CDAWCLOXVUBKRW-UHFFFAOYSA-N 2-aminophenol Chemical compound NC1=CC=CC=C1O CDAWCLOXVUBKRW-UHFFFAOYSA-N 0.000 description 1
- 125000001622 2-naphthyl group Chemical group [H]C1=C([H])C([H])=C2C([H])=C(*)C([H])=C([H])C2=C1[H] 0.000 description 1
- ZFIQGRISGKSVAG-UHFFFAOYSA-N 4-methylaminophenol Chemical compound CNC1=CC=C(O)C=C1 ZFIQGRISGKSVAG-UHFFFAOYSA-N 0.000 description 1
- CMOLPZZVECHXKN-UHFFFAOYSA-N 7-aminonaphthalene-1,3-disulfonic acid Chemical compound C1=C(S(O)(=O)=O)C=C(S(O)(=O)=O)C2=CC(N)=CC=C21 CMOLPZZVECHXKN-UHFFFAOYSA-N 0.000 description 1
- LSNNMFCWUKXFEE-UHFFFAOYSA-M Bisulfite Chemical compound OS([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-M 0.000 description 1
- ADNTYVJFDLSQTP-UHFFFAOYSA-L C([O-])([O-])=O.[Na+].OC1=CC=C(C(N)C(=O)O)C=C1.[Na+] Chemical compound C([O-])([O-])=O.[Na+].OC1=CC=C(C(N)C(=O)O)C=C1.[Na+] ADNTYVJFDLSQTP-UHFFFAOYSA-L 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- 108010010803 Gelatin Proteins 0.000 description 1
- PVNIIMVLHYAWGP-UHFFFAOYSA-N Niacin Chemical compound OC(=O)C1=CC=CN=C1 PVNIIMVLHYAWGP-UHFFFAOYSA-N 0.000 description 1
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- HOLVRJRSWZOAJU-UHFFFAOYSA-N [Ag].ICl Chemical compound [Ag].ICl HOLVRJRSWZOAJU-UHFFFAOYSA-N 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 239000013543 active substance Substances 0.000 description 1
- 238000013019 agitation Methods 0.000 description 1
- 150000001412 amines Chemical class 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- MCWXGJITAZMZEV-UHFFFAOYSA-N dimethoate Chemical compound CNC(=O)CSP(=S)(OC)OC MCWXGJITAZMZEV-UHFFFAOYSA-N 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 239000008273 gelatin Substances 0.000 description 1
- 235000011852 gelatine desserts Nutrition 0.000 description 1
- 239000012362 glacial acetic acid Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 125000000717 hydrazino group Chemical group [H]N([*])N([H])[H] 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 238000005286 illumination Methods 0.000 description 1
- 238000010348 incorporation Methods 0.000 description 1
- CBEQRNSPHCCXSH-UHFFFAOYSA-N iodine monobromide Chemical compound IBr CBEQRNSPHCCXSH-UHFFFAOYSA-N 0.000 description 1
- 239000012452 mother liquor Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052700 potassium Inorganic materials 0.000 description 1
- 239000011591 potassium Substances 0.000 description 1
- 235000007715 potassium iodide Nutrition 0.000 description 1
- 229960004839 potassium iodide Drugs 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 229940079877 pyrogallol Drugs 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- 230000005070 ripening Effects 0.000 description 1
- 230000001235 sensitizing effect Effects 0.000 description 1
- ADZWSOLPGZMUMY-UHFFFAOYSA-M silver bromide Chemical compound [Ag]Br ADZWSOLPGZMUMY-UHFFFAOYSA-M 0.000 description 1
- ZUNKMNLKJXRCDM-UHFFFAOYSA-N silver bromoiodide Chemical compound [Ag].IBr ZUNKMNLKJXRCDM-UHFFFAOYSA-N 0.000 description 1
- SQGYOTSLMSWVJD-UHFFFAOYSA-N silver(I) nitrate Inorganic materials [Ag+].[O-]N(=O)=O SQGYOTSLMSWVJD-UHFFFAOYSA-N 0.000 description 1
- 239000011780 sodium chloride Substances 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
- 239000012265 solid product Substances 0.000 description 1
- 150000003460 sulfonic acids Chemical class 0.000 description 1
- 229940044609 sulfur dioxide Drugs 0.000 description 1
- 235000010269 sulphur dioxide Nutrition 0.000 description 1
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 239000010937 tungsten 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
- G03C1/485—Direct positive emulsions
- G03C1/48538—Direct positive emulsions non-prefogged, i.e. fogged after imagewise exposure
- G03C1/48546—Direct positive emulsions non-prefogged, i.e. fogged after imagewise exposure characterised by the nucleating/fogging agent
- G03C1/48561—Direct positive emulsions non-prefogged, i.e. fogged after imagewise exposure characterised by the nucleating/fogging agent hydrazine compounds
Definitions
- This emulsion is prepared'by first fonic acids may be used inthe developer or emulforming ,in' the absence of ammonia and in one sion to develop direct positive images in an inor more stages silver salt grains consisting at ternal latent imageseznulsion. These compounds least partly of a silver.
- the photographic emulsion used in the process total silver halide, treating such grains with an of our invention is a gelatino-silverv halide emuliodine compound to bring the silver iodide up sion such as a silver bromide emulsion, a silver to at least 6%, ripening preferably in theabbromoiodide emulsion or .a silver chloroiodide sence of ammonia and then either washing.
- emulsion of this type is that known as Burtons emulsion, described in Wall, Inert gela me grams a El otographic Emulsions, .l92 9, pages 52and 7 K01 20 grams at 535? Burtons emulsion'is ,made' a's'jfoIlows: j' Water 5 A. site; time. Solution N0. 2 a
- silver halide grains "as"des”cribedon' pages 296 ripen at 45 'C; 'for'l'5' minutes during which timerthe gelatine dissolves.
- An internal laten image type of silver halideemulsion may be defined as one which, when a test portion is exposed to a light intensity scale for a fixed time between 'and 1 second, and
- the maximum density obtained with the surface developer is not greater- -than the maximum density obtained when the same emulsion is developed in the internal type developer.
- an internal latent image emulsiQnLWhen developed in an internal type develop er exhibits a maximum density at least 5; and preferably at'least 10, tiines the maximum density obtained when the sameemulsion is exposed in the'same way; and developed in a surface developer (E ample I)
- Ourfprocess is carriedtoutl by exposing the internallatent image'emulsion layer to an object or image and then placing the exposed emulsion layer directly in a silver halide developing solution' containing one or more of the naphthyl hydrazine sulionic aeidsliorf by incorporating the naphthyl hydrazine sulfonic acid in ,the emulsion, and placing the exposed layer in a 1 developing solution not containing the hydrazine ,compound.
- Developing agents suitable for usefin the process of our invention includethe usualphenolic or aminophenol type developingr agents such ⁇ as N-
- the developing solution should have a pH of from 8.5 to 13 depending upon the degree of activity of the particular hydrazine compound'which it contains although the preferred'range with most hydrazineeompounds, is
- sulfonic acids are suitable for use according to our invention ⁇ g NHNHz l-naphthyl hydrazine-G-sulfonic acid 7 FHN V Bellsteln 15, 645) NHNH2 l-naphthyl hydrazine-l-sulfionic acid 4-bromo-1-naphthyl hydrazineJ-sulfonic acid 7 H093 -NHNH2 2maphthjlilfidrazineW-sulfonic acid -NHVNH2 c Z-naphthyl-,lrvdrazinefi-sulfiomc'acid I (J.
- Example IV A portion of the same emulsion as that used in Example III was coated and exposed in the sameway as ExampleIII and was developed for from 1 to 5 minutes at 70 F. in' a solution'of the following composition:
- Example V A portion of the same emulsion as that used in Example III was coated; and exposed in'the same way as Example III and was. developed for from 1 to 5 minutes at 70 F, in a solution of the following composition:
- the 'yield'oi gray product was about 70 parts (55 per cent).
- 4-bromo-1-naphthyl hydrazine-'l-sulfonic acid wasfprepared in the same way as l-naphthyl hydrazinefi sulfonic acid. using e-bromo-l-naphthyl amine-hsulfonic'acid in place of lsnaphthylamine-G-sulfonic acid.
- . .-V4-bromo-1-naphthylarnine-7-sulfonic acid was a prepared as follows A. 1-acetylaminonaphthalene-sulfonic we A mixture of 600 parts of technical l-naphthyle amine-'lsulfo'nic acid (sodium salt); 2500 Y parts of glacial acetic acid, 500 parts of acetic anhydride and 54 parts of sodium acetate was heated underre flux for 6 hours, cooled, and filtered.
- the filtrate was acidified with 300 parts by volurheof concentrated hydrochloric acid, and the product filtered, washed with acetic acid, and dried, The yield consistedof 354 parts of mate.- rial containing about 20% sodium chloride" 1 B.
- said emulsion layer the presence of at least one naphthyl hydrazine sulfonic acid
- The'method of obtaining a direct positive image in a silver halide emulsion layer which comprises exposing to light rays to which the emulsion is sensitive, a silver halide emulsion layer a test portion of which upon exposure to alight intensity scale for a fixed time between 5 and I second and development for 3 minutes at 20CK'in the folloy'ving' internal type developer v p Grams Hydroquinone 15 Monomethyl-p-aminophenol sulfate Q. '15 Anhydrousjsod-ium sulfite 50 Potassium bromide 10-v Sodium hydroxide Sodium thiosulfate 20 Water to 1 liter.
- the method .of obtaining a direct positive image "in a'silver' halide emulsion layer, which comprises exposing to light rays to whichthe emulsion is sensitive, a silver halide emulsion layer a test portion of which upon exposure to a.
- v The method of obtaining a direct positive image in a silver halide emulsion layer, which comprises exposing to light rays to which the emulsion is sensitive, a. silver halide emulsion layer a test portion of which upon exposure to a light intensity scale for a fixed time between $5 and 1 second and development for 3 minutes "at 20 C. in the following internal type developer Grams Hydroquinone 15 Monomethyl-p-aminophenol sulfate 15 Anhydrous sodium sulfite -1 50 Potassium bromide 10 Sodium hydroxide 25 Sodium thiosulfate 20 Water to 1 liter.
- the method of obtaining a direct positive image in a silver halide emulsion layer which comprises exposing to light rays to which the emulsion is sensitive, a silver halide emulsion layer a test portion of which upon exposure to a light intensity scale for a fixed time between A and 1 second and development for 3 minutes at 20 C. in the following internal type developer (II) Grams Hydroquinone Monomethyl-p-aminophenol sulfate 15 Anhydrous sodium sulfite 50 Potassium bromide 10 Sodium hydroxide 25 Sodium thiosulfate Water to 1 liter.
Description
Patented July 22, 1952 i 2,604,400
d ric R. Bean and Harold itussell, Itooliter, N. Y., assignors to Eastman Kodak Co Deny, Rochester, N. Y., a corporati of s.
n1. J e
' -No Drawing. Application March 28.11951.
, Serial No. 218,072 V H 6 Claims. (Cl. 95-88) I; r i ii: This invention relatesatophotography and parand 297 of Mees' The Theory of the Photo ticularly to a method-of making direct positive graphic Process, 1942, 1 'espeoially useful for photographs. the process of our'invention. r a
I In Fallesen U. S. Patent 2,497,875, a method is Most of th internalilatent.iinageemulsions described for making direct positive photographs 5 are silver bromoiodide emulsions of liig-h'iodide with an internal latent image type emulsion by content, preferably containin'g'at least 10';%'.2 0% developing the exposed emulsion in an aerial fogof iodide. Burton's emulsion is an emulsion of gins. developer with access ofoxyg'en. this type, having a silver-iodide content of ap- Ives U. S. application; Serial No. 192,380, filed proximately 40% of the content of silver. halide.
October 26, 1950, now Patent No. 2,588,982, de- 10 It isnot absolutely essential,.however,. fo'r 'the 1 scribes a met-nosref-develop ng direct positive emulsiontocontain silveriodidey;
images in an exposed internal latent image emul- An internal latent image 'emul'sion made as desion by the use of hydrazine orcertain hydrazine scribed in Davey and Knott' U. S. application derivatives so that'no special aeration technique Serial No. 82,914, filed March-22, 1949, now Patfor production of the positive image is required. ent No. 2,592, 250,Vmay also be according to We have found that naphthyl hydrazine sulour invention. This emulsion is prepared'by first fonic acids may be used inthe developer or emulforming ,in' the absence of ammonia and in one sion to develop direct positive images in an inor more stages silver salt grains consisting at ternal latent imageseznulsion. These compounds least partly of a silver. salt" which is more soluare relatively non toxidand produce satisfacble in water thanusilver ibromideg subsequently tory direct positive images; without the addition converting the grains tosilve'r' bromide or silver of oxidizing agents to the developer or the use bromoiodide and if thefs'ilver iodide content of of any special aeration methodla the emulsion is less than 6% calculated on the The photographic emulsion used in the process total silver halide, treating such grains with an of our invention is a gelatino-silverv halide emuliodine compound to bring the silver iodide up sion such as a silver bromide emulsion, a silver to at least 6%, ripening preferably in theabbromoiodide emulsion or .a silver chloroiodide sence of ammonia and then either washing. out emulsion. It need not "contain optical sensitizsome of the soluble salts or washing out. the whole ing dyes although certain sensitizing dyes, may of the soluble salts, followedby the addition of be added. to it for the purpose pf optical sensitizsoluble salts such as soluble chloride or bromide.- ing or forpromoting reversal.-; fine emulsion An example of an emulsion made in this way is should be undigested or if digested; the diges-' as follows:
tion should be carried out without the use of sul- SoZufion'NO- 1 fur sensitizers. An emulsion of this type is that known as Burtons emulsion, described in Wall, Inert gela me grams a El otographic Emulsions, .l92 9, pages 52and 7 K01 20 grams at 535? Burtons emulsion'is ,made' a's'jfoIlows: j' Water 5 A. site; time. Solution N0. 2 a
Water l .1" j rams Ammonia-to form clear solut n. 0 g at C.
1 7 Water 520 cc.
B; Potassium:bromide 89 Potassiumiodide; ,50 Solutzon No. 3 Soft gelatin;' L' '-i- "'20 AgNo3 j a Water 1000 fvv t 52 cm }a 5 C- Solution No. 4 B isch'eated to 70 C. and A, cold, added to B with constant-shaking,- digested for zc minutes at; & S a C., and allowed toj 0501 slowly. oils-ad ed K1 40 rams at 45 c. after-beingallowed-to swell for'f20 -minutesin 50 Water 5 v W156"-dminedandmeltediTheemulsion'isthen Run Solutions Nos 2-' and 3 simultaneously GFW I i-i1), r into Solution No. 1 in a vessel, taking seconds -l ln--internal'latent imageemulsion i. i to do this. Then ripenfor'l minute at 45 C. whi h f rms he.,.1atent ima mostly. I s d Next add 235 grams ofinert gelatine (dry). Then silver halide grains, "as"des"cribedon' pages 296 ripen at 45 'C; 'for'l'5' minutes during which timerthe gelatine dissolves. Set and shred the emulsion and then wash until free from all soluble bromide and then add about 150 cc. of 10% solution of KCl (by weight), and then add water tomake 3 /2 *litreslif v An internal laten image type of silver halideemulsion may be defined as one which, when a test portion is exposed to a light intensity scale for a fixed time between 'and 1 second, and
developed for 4 minutes at 20 'C'. in the-ordinary, "surface developer (Example I), exhibits a maximum density not greater, than /5 the maximum density obtained when the 'same emulsion is equally exposed and developed for 3Vminutesjat j 20 C. in an internal type developer (Example II). Preferably the maximum density obtained with the surface developer is not greater- -than the maximum density obtained when the same emulsion is developed in the internal type developer.
Stated conversely, an internal latent image emulsiQnLWhen developed in an internal type develop er (Example II) exhibits a maximum density at least 5; and preferably at'least 10, tiines the maximum density obtained when the sameemulsion is exposed in the'same way; and developed in a surface developer (E ample I) v Ourfprocess is carriedtoutl by exposing the internallatent image'emulsion layer to an object or image and then placing the exposed emulsion layer directly in a silver halide developing solution' containing one or more of the naphthyl hydrazine sulionic aeidsliorf by incorporating the naphthyl hydrazine sulfonic acid in ,the emulsion, and placing the exposed layer in a 1 developing solution not containing the hydrazine ,compound. Developing agents suitable for usefin the process of our invention includethe usualphenolic or aminophenol type developingr agents such {as N- methyl p aminophenol' sulfate, hydroquinone,
catechol; 2-inethyl hydroquinone, 2-chlorohydro-' quinone, peaminophenol, and 'pyrogallol'. If V the naphthyl' hydrazine sulfonic acid'is in the developing solution, the developing solution should have a pH of from 8.5 to 13 depending upon the degree of activity of the particular hydrazine compound'which it contains although the preferred'range with most hydrazineeompounds, is
' from 1:11 10.10 312.
The iollowing naphthyl hydrazine. sulfonic acids'are suitable for use according to our invention} g NHNHz l-naphthyl hydrazine-G-sulfonic acid 7 FHN V Bellsteln 15, 645) NHNH2 l-naphthyl hydrazine-l-sulfionic acid 4-bromo-1-naphthyl hydrazineJ-sulfonic acid 7 H093 -NHNH2 2maphthjlilfidrazineW-sulfonic acid -NHVNH2 c Z-naphthyl-,lrvdrazinefi-sulfiomc'acid I (J. Prakt. Chem. 19. 369) I 2-naphthyl hydrazine-efi disulfonic acid ('1', B. Report, no. 986. 330) Z-naphthyl hydrazine-dJ-disulfonic acid; (P; B. Report. No. .986. 330) B|O3H I 2-naphtl1yl:hydrazine-6,8 dlsi11fonic acid An" ordinary surface type developer, that is, one which develops an image only on the surface of the grains of an internal latent image emulsion is the following; I r
Example!" 7 f Grams p-Hydroxyphenylglycine 10 Sodium carbonate (crystals) Water to 1 liter. Development time, 4min. at 20 C,
An internal type developer, that is," onewhich develops an image inside the grains oi'an'intemal latent image emulsion is the iollowihgi:
' v Example II it -Gramsc Hydroquinone -----q--Q;---,- ;L....- -a 15. N-methyl -p-aminophenolsulfa 15 Sodium sulfite (anhydrous) 50 Potassium bromide 10. Sodium hydroxide 25 Sodium thiosulfate (crystals) Q. 20 Water to .1 liter.', r w I 1 Development time, 3 min. at 20 C.
zit- 94 499;
- Example III An emulsion made as describedin the Davey and Knott application Serial 'No. 82,914 was coated on a support, dried and exposed on an intensity scale sensitometer to 3000 .Kelvi: n tungsten illumination and developed for from 1 to 5 minutes at 75 F. in a solution of .the following composition:
- Grams N-methyl-p-aminophenol sulfate 5 Hydroquinone 10 Sodium sulfite 75 Sodium hydroxide 10 5-methyl benzotriaz'ole 0.2
l-naphthyl hydrazine-G-sulfonic acid {1 Water to'l liter.
With these developing conditions a direct positive image of satisfactory characteristics wasobtained.
Example IV A portion of the same emulsion as that used in Example III was coated and exposed in the sameway as ExampleIII and was developed for from 1 to 5 minutes at 70 F. in' a solution'of the following composition:
. t; Grams Hydroquinone 15 Sodium sulfite 75 Sodium carbonate g 50 Sodium hydroxide '1 v 5-methyl benzotriazole x2 l-naphthyl hydrazine-S-sulfonic acid 4 Water'to 1 liter.
With these developing conditions a direct positive. image of satisfactory characteristics was obtained. 1 .51. 1
Example V A portion of the same emulsion as that used in Example III was coated; and exposed in'the same way as Example III and was. developed for from 1 to 5 minutes at 70 F, in a solution of the following composition:
7 v Grams Pyrocatechol 15 Sodium'sulfite j 75 Sodium hydroxide 15 5-methylbenzotriazole 0.2
l-naphthyl hydrazine-G-sulfonic acid" 3 Water to 1 liter. f i
With these developing conditions a direct positive image of satisfactory characteristics was.ob-
tained.
The incorporation of the naphthyl hydrazine ing dye. When the dried emulsions were ex each of two or three washes.
posed :and developed in the following solution a positive image was obtained: f I
- L Grams N-methyl-p-aminophenol sulfate I-Iydroquinone 10 Sodium sulfite '75 Sodium hydroxide 10 5-methylbenzotriazole' 0.2 Water to 1 liter.
Although the reversal effect obtained in our process 'does not require agitation of the developer or the presence of oxidizing agents, we believe that the fogging action obtained is related' to aerial oxidation. 'The active agent, which is derived from the hydrazine compound appears -to'have a long life in the developing solutions and only .brief exposures to atmospheric oxygen appear sufiicient to produce fogging even in the absence of continued aeration. Our process, thereforefhas. distinct advantages for deep. tank photographic processing.
l-naphthyl hydrazinei-B-sulfonic acid was prepared as follows: I
A warm solution of 6'7 parts of l-naphthylamine-S-sulfonic acid in 450 parts of water and 10 parts of sodium hydroxide was treated with 46 parts of concentrated sulfuric acid, and the mixture cooled to 0 C. Fifty parts of ice were added, followed by. 44 parts by volume of a 40 per cent solution of sodium nitrite. After the solution had been stirred in the cold for 2 to 3 hours the brown diazonium salt was removed by filtration and washed with cold water.
The salt'was then added in portions to a cold (less than 10 C.) solution of parts ofstannous chloride dihydrate in 275 parts by volume of concentrated hydrochloric acid and 135- parts or" water. The mixture was stirred overnight; filtered, and the, white solid product washed thoroughly with water. 1
l-naphthyl hydrazine-'Z-sulfoni'c acid was prepared as follows:
A solution of parts (0.6 mole) of the sodium salt of 1:naphthylamine-l-sulfonic acid (70-75 per cent pure) in 2400 parts of water was stirred with 25 parts of Nuchar and filtered. The filtrat'ewas combined with '78 parts by volume of 40 per cent sodium nitrite solution, cooled to 15-20 C., and added in a fine stream during of'an hour to a cold solution of 93 parts of concentrated sulfuric acid in 500 parts of water. The temperature was maintained belowl0 0., and the mixture stirred for 1% hours after the addition was complete. The solid diazonium salt was allowed to settle, andthe clear mother liquor decanted. The dark brown solid was filtered and washed with a little cold water. It was made into a'thin' paste with water and added gradually hour) 'to' a cold solution (previously filtered throughFilter Cel) of 300 parts ofstannous chloride dihydrate in 550 parts by volume of concentrated hydrochloric acid and 275 parts of water. The reaction temperature was kept below 10 C. by an ice-saltbath and regulation of the rate of addition.
and washed thoroughly with water; this neces sitates removal of the cake from the filter for I The 'yield'oi gray product was about 70 parts (55 per cent).
4-bromo-1-naphthyl hydrazine-'l-sulfonic acid wasfprepared in the same way as l-naphthyl hydrazinefi sulfonic acid. using e-bromo-l-naphthyl amine-hsulfonic'acid in place of lsnaphthylamine-G-sulfonic acid.
. .-V4-bromo-1-naphthylarnine-7-sulfonic acid was a prepared as follows A. 1-acetylaminonaphthalene-sulfonic we A mixture of 600 parts of technical l-naphthyle amine-'lsulfo'nic acid (sodium salt); 2500 Y parts of glacial acetic acid, 500 parts of acetic anhydride and 54 parts of sodium acetate was heated underre flux for 6 hours, cooled, and filtered. The filtrate was acidified with 300 parts by volurheof concentrated hydrochloric acid, and the product filtered, washed with acetic acid, and dried, The yield consistedof 354 parts of mate.- rial containing about 20% sodium chloride" 1 B. c-bro'mosl'maphthyZamineJ-sdlfonic acid A solution of 324'parts of'the' l-acetylamino naphthalene-'I-sulfonic acid in 1400 parts of glacial acetic aeid'containing 100 parts of sodium acetate was filtered, and the'filtrate diluted with 2000 parts of acetic 'a'cid: Bromine (160 'parts) was-added dropwis'e'to this solution at 135-409. One hour later, the unused bromine was destroyed with sulfurdioxide, 82 partsof sodium acetate was added, and the mixture filtered.
Hydrolysis to the free amine was carried out by heating for 1.1/ hours on the steam bath with 800 parts of 6N hydrochloric acid. The 4-bromol-naphthylamine-7-sulfonic acid which separated (176 parts) was filtered, washed and dried. I
2.-,naph thyl' hydrazine'l-sulfonic acid and 2-,- naphthyl hydrazih-QH-disulfonic acid were'pre-' pared in the same way as 1,-naphthyl hydrazine- 'osulion ic acid using respectively, 2.naphthylamine- 7 sulfonic, acid and 2-naphthylamine-6,8- disulfonic acid instead of lnaphthylamineefisulfonic acid;
and l second anddevelopment for 3 minutes Y at2'0" C. in the following internal type: developer .(II) v V Grams Hydroquinone 1 15 Monomethyl-p-aminophenol sulfate 15 Anhydrous sodiumsulfite 50 Potassium bromide 10 Sodium hydroxide 25 Sodium thiosulfate- 20 Water to 1 liter.
gives a maximum dnsity at least times the maximum density obtained when the equallyexposed silver halide emulsion is developed'for 4 minutes .at 20 C. inthe following surface devel- Water to ,1 liter.
said emulsion layer the presence of at least one naphthyl hydrazine sulfonic acid;
2. The method ofobtaining a'direct positive image .infa silver halide emulsion; layer, which comprisesexposing 'to light rays to which the and developingronly the unexposed portion-oil,
emulsion; 111s "sensitive," asilver. halide emulsion layer 'a test'portion "of which upon exposure to a light intensity scale for: afixed time between and 1 second and development for 3 minutes at 2,0.- 0.1;; in theiollowingintemm type devel- Qnst X f V Grams l il ll V I 55 T----%-;--1?';?;----;-"-;----1 Monomethyl-p-aminophenol sulfate 15 Anhydrous sodium sulfite 50 Potassium bromide 10 Sodium hydroxide 25 Sodium thiosulfateli;
Water tolliter. i
gives a'maximum density at "least 5 times ithe maximum density obtained whentthe equallyexposed silverv halide emulsion is j developed .for' fl minutes at 20C. in the'following surface devel oper (I) l l V I I dm y en ye n l-J77": Sodium carbonate 100,
Water to 1 liter.
and developing only the unexposed portion of said emulsion layer in a developer containing at least one naphthyl' hydrazine sulfonic acid.
' 3'. The'method of obtaining a direct positive image in a silver halide emulsion layer, which comprises exposing to light rays to which the emulsion is sensitive, a silver halide emulsion layer a test portion of which upon exposure to alight intensity scale for a fixed time between 5 and I second and development for 3 minutes at 20CK'in the folloy'ving' internal type developer v p Grams Hydroquinone 15 Monomethyl-p-aminophenol sulfate Q. '15 Anhydrousjsod-ium sulfite 50 Potassium bromide 10-v Sodium hydroxide Sodium thiosulfate 20 Water to 1 liter.
gives a maximum-density at least 5'times the maximum density obtained when the equally ex posed-silver halide emulsion is developed for 4 minutes -at'zo" C. in the following surface developer (I):
- Grams p Hydroxyphenylglycine 10;
Sodium carbonate 100 Water tol liter.
' and developing only the unexposed portion of said emulsion layer in a developer containing l-naphthyl hydrazine-'l-sulfonic acid.
4. The method .of obtaining a direct positive image "in a'silver' halide emulsion layer, which comprises exposing to light rays to whichthe emulsion is sensitive, a silver halide emulsion layer a test portion of which upon exposure to a.
light intensity scale for a fixed time between A and 1 second and development for 3 minutes at 20 C. in the following internal type developer (II):
j 7 i V. v Grams Hydroquinone 15' Monomethyl p aminophenol sulfate '15 Anhydrous sodiums'ulfitei Potassium bromide -l- 10 Sodium hydroxide ium FhiQ I WQ 4 waterto iterix maximum density at least 5 times the ives a maximum density obtained when the equally exposed silver halide emulsion is developed for 4 minutes at 20 C. in the following surface developer (I) Grams p-I-Iydroxyphenylglycine 10 Sodium carbonate 100 Water to 1 liter.
and developing only the unexposed portion of said emulsion layer in a developer containing l-naphthyl hydrazine-B-sulfonic acid.
5. vThe method of obtaining a direct positive image in a silver halide emulsion layer, which comprises exposing to light rays to which the emulsion is sensitive, a. silver halide emulsion layer a test portion of which upon exposure to a light intensity scale for a fixed time between $5 and 1 second and development for 3 minutes "at 20 C. in the following internal type developer Grams Hydroquinone 15 Monomethyl-p-aminophenol sulfate 15 Anhydrous sodium sulfite -1 50 Potassium bromide 10 Sodium hydroxide 25 Sodium thiosulfate 20 Water to 1 liter.
gives a maximum density at least times the maximum density obtained when the equally exposed silver halide emulsion is developed for 4 minutes at 20 C. in the following surface developer (I):
Grams p-Hydroxyphenylglycine Sodium carbonate 100 Water to 1 liter.
'10 and developing only the unexposed portion of said emulsion layer in a developer containing l-naphthyl hydrazine-G-sulfonic acid and 1- naphthyl hydrazine-'Z-sulfonic acid.
6.'The method of obtaining a direct positive image in a silver halide emulsion layer, which comprises exposing to light rays to which the emulsion is sensitive, a silver halide emulsion layer a test portion of which upon exposure to a light intensity scale for a fixed time between A and 1 second and development for 3 minutes at 20 C. in the following internal type developer (II) Grams Hydroquinone Monomethyl-p-aminophenol sulfate 15 Anhydrous sodium sulfite 50 Potassium bromide 10 Sodium hydroxide 25 Sodium thiosulfate Water to 1 liter.
anddeveloping only the unexposed portion of said emulsion layer in a developer containing 4-bromo-1-naphthyl hydrazine-7 -sulfonic acid.
FREDERIC R. BEAN. HAROLD D. RUSSELL.
No references cited.
Claims (1)
1. THE METHOD OF OBTAINING A DIRECT POSITIVE IMAGE IN A SILVER HALIDE EMULSION LAYER, WHICH COMPRISES EXPOSING TO LIGHT RAYS TO WHICH THE EMULSION IS SENSITIVE, A SILVER HALIDE EMULSION LAYER A TEST PORTION OF WHICH UPON EXPOSURE TO A LIGHT INTENSITY SCALE FOR A FIXED TIME BETWEEN 1/100 AND 1 SECOND AND DEVELOPMENT FOR 3 MINUTES AT 20* C. IN TH FOLLOWING INTERNAL TYPE DEVELOPER (II):
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| BE510220D BE510220A (en) | 1951-03-28 | ||
| US218072A US2604400A (en) | 1951-03-28 | 1951-03-28 | Naphthyl hydrazine sulfonic acids in direct positive photographic processes |
| DEE5231A DE925691C (en) | 1951-03-28 | 1952-03-21 | Process for producing a direct positive image in a halide silver emulsion layer |
| FR65219D FR65219E (en) | 1951-03-28 | 1952-03-28 | Photographic inversion process and new products for its implementation |
| GB8003/52A GB712355A (en) | 1951-03-28 | 1952-03-28 | Improvements in photographic processes |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US218072A US2604400A (en) | 1951-03-28 | 1951-03-28 | Naphthyl hydrazine sulfonic acids in direct positive photographic processes |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2604400A true US2604400A (en) | 1952-07-22 |
Family
ID=22813626
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US218072A Expired - Lifetime US2604400A (en) | 1951-03-28 | 1951-03-28 | Naphthyl hydrazine sulfonic acids in direct positive photographic processes |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US2604400A (en) |
| BE (1) | BE510220A (en) |
| DE (1) | DE925691C (en) |
| FR (1) | FR65219E (en) |
| GB (1) | GB712355A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2675318A (en) * | 1951-06-27 | 1954-04-13 | Eastman Kodak Co | Hydroquinone monosulfonate in direct positive photographic developers |
| US3186840A (en) * | 1958-12-11 | 1965-06-01 | Agfa Ag | Direct positive colored photographic elements containing dihydrazones and process for forming colored masks therefrom |
-
0
- BE BE510220D patent/BE510220A/xx unknown
-
1951
- 1951-03-28 US US218072A patent/US2604400A/en not_active Expired - Lifetime
-
1952
- 1952-03-21 DE DEE5231A patent/DE925691C/en not_active Expired
- 1952-03-28 GB GB8003/52A patent/GB712355A/en not_active Expired
- 1952-03-28 FR FR65219D patent/FR65219E/en not_active Expired
Non-Patent Citations (1)
| Title |
|---|
| None * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2675318A (en) * | 1951-06-27 | 1954-04-13 | Eastman Kodak Co | Hydroquinone monosulfonate in direct positive photographic developers |
| US3186840A (en) * | 1958-12-11 | 1965-06-01 | Agfa Ag | Direct positive colored photographic elements containing dihydrazones and process for forming colored masks therefrom |
Also Published As
| Publication number | Publication date |
|---|---|
| GB712355A (en) | 1954-07-21 |
| DE925691C (en) | 1955-03-28 |
| FR65219E (en) | 1956-02-07 |
| BE510220A (en) |
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