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
  • G03C5/00—Photographic processes or agents therefor; Regeneration of such processing agents
  • G03C5/26—Processes using silver-salt-containing photosensitive materials or agents therefor
  • G03C5/29—Development processes or agents therefor
  • G03C5/315—Tanning development
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/004—Photosensitive materials
  • G03F7/06—Silver salts

Definitions

• the developed emulsion is pressed into contact With an absorbent receiving sheet such as paper to cause the less exposed regions, and thus the less developed regions, of the emulsion to adhere to the receiving sheet. Subsequently, when the emulsion and receiving sheet are separated a stratum of the less exposed regions of the emulsion remains on the sheet and appears as a positive silver image of the original subject.
• an absorbent receiving sheet such as paper
• the solution for activation of the exposed emulsion layer is necessarily alkaline to cause the exposed silver halide emulsion to develop rapidly and to be hardened in the more exposed regions.
• the mentioned patents recommend for this purpose the use of a sodium carbonate solution containing, among other ingredients, gelatin softening agents such as urea.
• a far superior alkaline activating solution for the process is one containing as the source of alkalinity a fi-lower alkyl aminoethanol such as B-diethylaminoethanol, fi-monomethylaminoethanol or [idimethylaminoethanol.
• a fi-lower alkyl aminoethanol such as B-diethylaminoethanol, fi-monomethylaminoethanol or [idimethylaminoethanol.
• These alkaline materials have the property of supplying the requisite alkalinity for the process yet can be readily packaged in the form of noncrystallizing concentrated solutions Whereas packages of the sodium carbonate compositions tend to cake and thus dissolve with difficulty. Also the carbonate solutions tend to crystallize out on processing equipment and eventually to render movable parts diflicult or impossible to operate.
• the B-lower alkylaminoethanols of our invention are valuable in reducing unwanted transfer of background areas from the matrix to the reception layer and increasing the press life of otfset plate images made by this process.
• a substantially unhardened gelatino-silver halide emulsion (having a hardness as defined in the above patents) is prepared as described in US. Patent 2,716,059 above and containing a mixture of tanning and substantially non-tanning silver halide developing agents.
• the emulsion is coated on a paper support and dried.
• the resultant sensitive element is then exposed to a two-toned subject (a line or halftone subject) if desired by reflex printing methods and placed in a 5 percent aqueous solution of [i-diethylaminoethanol.
• the sensitive element and receiving sheet are separated leaving a stratum of the less exposed and thus less hardened regions of the emulsion adhered to the receiving sheet.
• the result is a positive line or half tone silver-containing image aflixed to the sheet.
• the transfer operation may be repeated 2. number of times by merely rewetting the sensitive element in the alkaline solution and squeegeeing to a fresh reception sheet.
• spaasss Solutions A and B were used for activating exposed samples of a projection speed sensitive element prepared as described in Yutzy et al. U.S. Patent 2,596,756 and when development of each sample was complete transfers were made to lithographic paper plates as described in the Clark et a1. U.S. Patent 2,763,553 granted September 18, 1956, to yield silver-containing images on the hydrophilic surface of the plates. Each plate was then inked and printed in a lithographic printing press. It was noted that in this process Solution B caused the paper support of the exposed element to split apart during the transfer of the colloid image to the printing plate, the transferred image was not uniform in density, and the receptivity of the image for the printing ink was poor. Also, Solution B tended to cause the image on the plate to bleed and thus lose definition when activation of the emulsion was carried out at temperatures of the order of 85 F., whereas Solution A did not produce this eifect.
• gelatino-silver halide emulsions it may still be advantageous to add a gelatin softening agent such as urea or acetamide tofacilitate the transfer of the unhardened regions of the emulsion.
• a gelatin softening agent such as urea or acetamide tofacilitate the transfer of the unhardened regions of the emulsion.
• the amine solutions may be used over a range of pH of about 9 to 11, it being convenient to use acetic acid for the purpose of adjusting EXAMPLE III
• a buffered concentrated liquid activator solution was prepared by adding 0.65 cc. of glacial acetic acid to 20 grams of B-diethylaminoethanol.
• Another concentrate was prepared by adding the same amount of glacial acetic acid to fi-dimethylaminoethanol.
• the gelatin tanning and non-tanning developing agents are present in the emulsion.
• Other useful tanning and non-tanning silver halide developing agents are disclosed in the above patents.
• the process may be carried out using only a gelatin tanning silver halide developing agent in the emulsion or in the amine solution.
• Useful tanning and non-tanning developing agents are described in the above patents.
• a method of photographic reproduction which comprises exposing to a subject a substantially unhardened gelatino-silver halide emulsion layer, said emulsion being not harder than a gelatin layer containing 0.7 gram of formaldehyde per pound of gelatin freshly coated, developing said exposed emulsion layer with an aqueous alkaline solution of a ,B-lower alkyl-aminoethanol in the presence of a gelatin tanning silver halide developing agent to obtain a hardened gelatin and silver image in the areas of the emulsion layer corresponding to the highlights of the subject, and substantially unhardened gelatin, silver and silver halide in the areas of the emulsion layer corresponding to the shadows of the subject, said development being such as to prevent any substantial tanning of the emulsion layer in said areas corresponding to the shadows of the subject, pressing a .sheet having an absorbent surface against said emulsion layer while said emulsion layer is moist to cause only the shadow areas of the e
• a method of photographic reproduction which comprises exposing to a subject a substantially unhardened galatino-silver halide emulsion layer, said emulsion being not harder than a gelatin layer containing 0.7 gram of formaldehyde per pound of gelatin freshly coated, developing said exposed emulsion layer with an aqueous alkaline solution of a fi-lower alkylaminoethanol in the presence of both a gelatin tanning silver halide developing agent and a substantially non-tanning silver halide developing agent to obtain a hardened gelatin and silver image in the areas of the emulsion layer corresponding to the highlights of the subject, and substantially unhardened gelatin, silver and silver halide in the areas of the emulsion layer corresponding to the shadows of the subject, said development being such as to prevent any substantial tanning of the emulsion layer in said areas corresponding to the shadows of the subject, pressing a sheet having an absorbent surface against said emulsion layer while said emulsion layer is moist

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Silver Salt Photography Or Processing Solution Therefor (AREA)
• Photosensitive Polymer And Photoresist Processing (AREA)

Priority Applications (5)

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Publications (1)

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Cited By (5)

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Citations (4)

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• 0
  • BE BE590925D patent/BE590925A/xx unknown
• 1959
  • 1959-05-20 US US814378A patent/US3043688A/en not_active Expired - Lifetime
• 1960
  • 1960-04-30 DE DEE19275A patent/DE1098360B/de active Pending
  • 1960-05-16 GB GB17130/60A patent/GB945496A/en not_active Expired

Patent Citations (4)

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