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
  • G03C1/492—Photosoluble emulsions
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C5/00—Photographic processes or agents therefor; Regeneration of such processing agents
  • G03C5/26—Processes using silver-salt-containing photosensitive materials or agents therefor
  • G03C5/38—Fixing; Developing-fixing; Hardening-fixing

Definitions

• This invention relates to a process for forming images from photosoluble (photosolubilizable) silver halide layers.
• the present invention constitutes an improvement in a silver halide photosolubilization process by the use of an organic chemical compound adjuvant which helps to prevent dissolution of silver halide in unexposed areas while allowing dissolution to proceed in the exposed areas. Because of this characteristic, the adjuvant is referred to herein as a maximum density maintainer, or D maintainer.
• a silver halide solvent comprising an aqueous bath of an alkali metal or ammonium thiosulfate (preferably, alkali metal); the improvement being characterized by the presence, while said layer is in said bath at a pH of 3.5 to 11.0, of D maintaining amounts of the auxiliary organic compound devoid of ionizable iodine, or oxidizing or reducing groups that are active at the working pH, said compound having (1) at least one polar or ionic group, (2) at least one hydrocarbon group, and (3) a molecular weight between 61 and 300,
• the organic compound being present in sufficient quantity to retard solution of the unexposed silver halide and within the range of 0.1 to 50 grams per liter of the aqueous bath.
• the auxiliary compound should be devoid of oxidizing groups because these tend to oxidize the silver salts of the compound of step (a) so that exposed and unexposed areas cannot be distinguished easily in terms of their rates of solution in a silver halide solvent.
• the D maintaining organic compound effects an improvement by retarding the dissolution of silver halide preferentially in the unexposed as compared to the exposed areas of the photosoluble element.
• the presence of the D maintaining compounds has the advantage that more vigorous processing conditions may be used which can lead to greater speed. Also, greater latitude of processing conditions is permitted, e.g., in time, temperature and pH. Better control of contrast can be achieved in the presence of these compounds and, in the case of lthographic films, better halftone dot rendition is possible.
• a photosoluble silver halide layer as defined in Blake U.S. 3,155,507 preferably a layer of silver chloride emulsion insolubilized with 2-mercapto-4-phenylthiazole or a related mercaptan as disclosed in said patent is prepared.
• the element may advantageously have a photographic optical sensitizing dye associated with its silver halide crystals as disclosed in assignees copending application of Blake, U.S. Ser. No. 390,460 filed Aug. 18, 1964 (U.S.P. 3,384,- 485, May 21, 1968).
• the photosoluble layer is exposed, imagewise, to actinic radiation and then treated in an aque ous bath comprising from 0.1 to 2 moles per liter of a thiosulfate, e.g., sodium thiosulfate silver halide solvent and an organic DmflLx maintainer as defined above.
• a thiosulfate e.g., sodium thiosulfate silver halide solvent
• An organic DmflLx maintainer is 2-butoxyethanol in a concentration of 0.5 to 20 ml./1iter, preferably from 2 to 15 ml./ liter.
• the time and temperature of treatment in the aqueous bath are obviously dependent variables but at a temperature of F. the time should be about 30 sec. to 5 min.
• This treatment removes silver halide from the exposed areas at a much faster rate than from the unexposed areas, leaving a positive silver halide image.
• the presence of an organic compound such as Z-butoxyethanol further lowers the rate of dissolution of the unexposed silver halide, relative to that of the exposed silver halide, contributing to better image formation especially to higher densities in unexposed areas.
• a useful positive image can be produced, particularly for viewing by projection, by this single treatment, although a washing step is generally used.
• it is desirable to intensify the silver halide image usually by treating with a photographic silver halide developer solution to reduce the image to one of black metallic silver.
• the silver halide image may be fogged prior to reduction by flashing to white light or, more conveniently, by use of a prefogged element such as described in assignees copending U.S. applications of Blade, U.S. Ser. No. 629,426 and Haugh U.S. Ser. No. 478,421
• Other methods of intensifying the silver halide image e.g., by toning, color developing, etc., are disclosed in U.S. 3,155,507.
• any of the various photosoluble silver halide elements described in the U.S. patents and Blake and Haugh applications listed above can be used in the process of this invention. These, of course, may be modified as described in the patents and applications by variations in the silver halide, the binder (if present), the organic compounds for insolubilization of silver halide (whose utility can be established by the simple tests defined therein for determination of other useful compounds), the adjuvants generally employed ll'lSllVClf halide systerns the supports, and in the relative concentrations of the various components.
• Various auxiliary layers may be present, such as abrasion overcoatings, subbing layers, and antihalation undercoats o'r backing layers.
• the elements may include multilayer as well as monolayer structures,
• the various layers, including the support may include inert ingredients, e.g., pigments, organic polymer lattices, and matting agents.
• the silver halide may be insolubilized by treatment with an appropriateorganic compound either during emulsion manufacture or by treatment'of the coated element with a solution of the organic compound.
• the dissolution developer may contain various adjuvants such as shown below in Example III.
• sential components for this invention are water, a silver halide solvent, and a D maintainer.
• a silver halide solvent for this invention, water, a silver halide solvent, and a D maintainer.
• Numerous useful silver halide solvents are disclosed in US. 3,155,507 but in the present application only the use of preferred silver halide solvents which contain the thiosulfate anion will be described.
• EXAMPLE I A light-sensitive gelatino-silver chloride coagulum, made by precipitation, coagulation and washing in the manner taught in Moede, US. Patent 2,772,166, was redispersed in an aqueous gelatin solution so as to achieve a gelatin to silver chloride weight ratio of 0.79. The resulting emulsion was digested at 170 F. for 20 minutes in the presence of 0.80 g. of 2-mercapto-4-phenylthiazole and 0.025 g. of the merocyanine of Example I of Kendall U.S.P. 2,342,546, Feb. 22, 1944, per mole of silver chloride.
• Strip No. 1 the control, was processed for 45 sec. in equal parts of water and of the following silver halide solvent solution.
• the strip was rinsed in water for 15 sec., white fluorescent-room lamps were turned on, the image was intensified for 1 min. in the following solution:
• EXAMPLE II Exposed film strips as described in Example I were processed for 4 minutes at 68 F. in various dissolution developer solutions, then washed, light fogged, intensified in a silver halide photographic developing solution, washed and dried as described in Example I.
• the control strip (No. 1) was processed in a dissolution developer consisting of 270 nil. of the undiluted silver halide solvent solution of Example I, 4 g. Na SO 2.4 ml. of glacial acetic acid, and adding water to bring the total volume to 300 ml., the pH being 4.8.
• Strip No. 2 was processed in a similar solution but one which also contained 3 ml. of the D Maintainer 1, 2-dichloroethane, the pH being 4.8 (an optimum pH).
• Strip No. 1 had a D of 2.95 and a gamma of 4.05.
• Strip No. 2 processed in the presence of the D maintainer, had a D of well over 4.0 (the maximum which could be determined with the densitometer in use), had an extremely high gamma of about 28, and had an apparent speed about 5.6 times that of the control (at 0.02 optical transmission density above base plus fog level).
• EXAMPLE III A silver halide solvent solution was prepared like the control solution of Example I except that the pH was 6.0. A number of similar silver halide solvent solutions were prepared but to which was added one of the D maintainer compounds listed below at a concentration of either 0.05 or 0.1 percent by weight.
• Example II Exposed film strips as described in Example I were processed for 2 minutes at 68 F. in each of these silver halide solvent solutions. Processing of the films was. then continued as in Example I except that 6 g. of sodium hexametaphosphate were added per liter of the intensifying solution. Results are given in Table 2 and the effectiveness of the D maintainer is indicated by the increase in D (optical transmission density) over the control.
• Example III gram of 2-niercapto-4-cyclohexylthiazole per mole of (CH COH 2.25 silver halide, on the film base of Example I.
• the dried 3 2 4 element was then exposed behind a /2 step wedge for a( 2)5 5 seconds to the light source of Example I at a distance a( 2)5 2 5 of about inches.
• Exposed elements were then immersed 2)s in a dissolution developer (compositions shown in Table H N(CH NH 3) for 30 seconds and 3 minutes, rinsed in water, rc- CH (CH O(CH OH exposed, and bathed in a conventional photographic de- CH (CH OI-I 3.5 veloper of the type given in Example III.
• Example III Benzoic acid 2.0 g i g g g 5-8 Dmtmafter 30 seconds in...
• Example III The compounds listed in Example III fall within three general classifications, namely,
• Aromatic hydrocarbons and nitro, amino, aldehyde, halogen, carboxy and sulfonic acid-substituted aromatic hydrocarbons
• said process being characterized by the presence while said layer is in said bath, at a predetermined pH, of D -maintaining amounts of an auxiliary organic compound different from that in (a) devoid of ionizable iodine or oxidizing or reducing groups which are active at the working pH, said compound having (1) at least one polar or ionic group, (2) at least one hydrocarbon group, and (3) a molecular weight between 61 and 300, the organic compound being present in suflicient quantity to retard solution of the unexposed silver halide and within the range of 0.1 to grams per liter of the aqueous bath.
• n-Octadecanol Cyclohexanol Benzenesulfonic acid Br BICH CHgBf-l-ClCHaCHgCl Benzyl ether of 2-methoxyethanol..- 2-amino l-naphthalene-sulionlc aeid Diethylene glycol--. l-naphthalenesultonic acid Ethylene glycol 1,2-naphthaqmnone-4-snlfonic acid ycerol 4-amino-1-naphthalene sulionic acid Allyl alcohoL.
• the alcohols formed during hydrolysis fall under the generic formula.
• the present invention has the advantages of the basic process of photosolubilization, especially that of a very simple, single step process of obtainin a positive image.
• Advantages over the basic process include increased optical densities in unexposed or lightly exposed areas, both for silver halide images and for intensified images.
• processing is simpler because the D maintainers make the effects of such variables as concentration of silver halide solvent, solution of pH, processing times and temperatures less critically.
• the D maintainers often increase contrast and apparent speed although decreases in one or both of these variables sometimes occur.
• Another method is available for controlling speed and contrast. Still other advantages will be apparent from the above description of the invention.
• a photosolubilization process for forming a directpositive silver halide image which comprises:
• X Cl, Br, N0 CHYOH, C H YY", H, COOH or CHO; or NH when N 4; or OCH only when m:
• Y Cl, Br, OH, H, COOH, CHO, C H X'X", C H X'X" or NH when n 4;
• X' any value of X except NH 10
• X" any value of X plus SO H
• Y' any value of Y
• Y" any value of Y.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Silver Salt Photography Or Processing Solution Therefor (AREA)
• Non-Silver Salt Photosensitive Materials And Non-Silver Salt Photography (AREA)
• Photosensitive Polymer And Photoresist Processing (AREA)

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• 1967
  • 1967-06-23 US US653590A patent/US3495983A/en not_active Expired - Lifetime
  • 1967-06-23 US US648229A patent/US3493373A/en not_active Expired - Lifetime
  • 1967-06-23 US US648250A patent/US3495982A/en not_active Expired - Lifetime
• 1968
  • 1968-06-21 BE BE716966D patent/BE716966A/xx unknown
  • 1968-06-21 GB GB29787/68A patent/GB1234993A/en not_active Expired
  • 1968-06-22 DE DE19681772705 patent/DE1772705A1/de active Pending

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