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
  • G03C1/035—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein characterised by the crystal form or composition, e.g. mixed grain
• • 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
  • G03C1/035—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein characterised by the crystal form or composition, e.g. mixed grain
  • G03C2001/03564—Mixed grains or mixture of emulsions

Definitions

• valuable photographic emulsions' are obtained by mixing the components necessary for making an emulsion and subsequently ripening the mixture, and, dur- 5 ing the ripening stage, withdrawing at least two portions of the emulsion of different degrees of ripening and then uniting these portions,
• Emulsions made in this manner have the property that when spread. upon a support they give light-sensitive layers which, whileof good covering power, have a high sensitivity and a remarkable freedom from halation, even without the usual anti-halatlon devices. If the emulsion is made from only two withdrawn portions its properties will be influenced according tothe degree of ripening of each portion; for instance, if the portion of less ripeness prevails there will be obtained an emulsion which is less sensitive to light and shows steeper gradation and stronger covering power; if the portion of greater ripeness prevails the emulsion will. have a high sensitivity and a greater softness.
• the final emulsion obtained will have softer gradations which, according to the mode of working, will not be at fault or only little so'i'n the shadows. If the quantities of the portions of high degree of ripeness are still further increased at the cost of the quantities of the portions or lower degree of ripeness, one can lights.
• gradations oi emulsions may be influenced within wide limits by the manufacture of the emulsion and may be adapted to the requirements of the photographic material desired.
• the present invention may be used for making acid emulsions, ammoniacal emulsions and, it
• layers canbe obtained for various purposes oi -photography and kinematography, for instance, negative films, plates, diapositive layers, reversal, films, fine-gram layers, layers sensitive .to light for color photography and color kinematography, layers for'light-sound production,,.and developing papers;
• the negative and positive layers produced by the process may be used alone or in combination with other layers which are obtained from emulsions made by known processes. If as the negative layer there is used one the gamma in accordance with the invention may be used alone or together with other emulsions made according to this process or to *a known process.
• Example 1 A filtered solution of 1200 parts of silver nitrate, 1100 parts of ammonia (specific gravity 0.91) and 40 parts of citric acid in 6000 parts of water is run, in the course of 20 minutes, into a stirring vessel I containing a solution at a temperature of 28 C. consisting of 6000 parts of we.-
• the stirring vessel I In the stirring vessel I the temperature of 60 C. is maintained for about 50-60 minutes and care is taken, by adjusting the speed of outflow, that after this time, according to the desired gradation, all or the greater part of the mixture in vessel I is run into the vessel 11 cooled to 25 C.
• the mixture in vessel 11 is mixed with a solution of 250 parts of mediumand 250 parts of soft gelatine in 1000 parts of water, the whole is stirred for some time longer and the mixture in vessel 11 is allowed to solidify by cooling. The completely solid emulsion is cut up into small pieces and in this form thoroughly washed.
• the temperature in vessel I is raised to 50 C. this temperature is maintained until the desired sensitiveness to light has been attained and all the emulsion is in the vessel 11, cooled to 25 C.
• filtered emulsion is applied to the supports and dried as usual.
• composition of the emulsion By varying the composition of the emulsion by omitting sensitizers or using further sensitizers, and further by varying the ripening process, universal, portrait, dispositive, pan, reversal and other emulsions can be obtained.
• Example 2 The solutions necessary for making the emulsion areas follows:-
• Parts Solution 1 Water 6000 Silver nitrate 1200 Ammonia (specific gravity 0.91) to which are added 1100 Citric acid dissolved in Water 100 Parts Solution II: Water 6000 Hard gelatine 600 Potassium bromide 1000 Potassium iodide 18 Crystaliized sodium carbonate 20 Erythrosine solution (1:300)- 300 Parts Solution 111: Water 3000 Medium gelatine 250 Soft gelatine 550 Parts Solution IV: Water 2000 Potassium bromide solution of 10 per cent strength--- 10 Soft gelatine 400 Medium gelatine 300 Tarts Solution V: Alcohol 500 Chrome alum solution of 2 per cent strength 100 Tartrazine solution (1:100) 300 I a temperature of 28 C. of the emulsion thus obtained about 6 liters are run into Solution III,
• Solutions I, II and III are now mixed. The mixture is allowed to solidify by cooling and the solidifled emulsion is washed thoroughly with flowing water.
• Solutions I, II, I11 and IV are now mixed together.
• the mixture is diluted with water to 26 liters and the emulsion allowed to solidify by cooling.
• the solidified emulsion before it is cast is subdivided into several parts of about the same size as each other.
• the first part is melted at 50" 0., kept at this temperature for 5 minutes and then the second part of the emulsion is added and the procedure continued until all has been melted.
• Solution V To the completely melted emulsion there is then added Solution V and, after mixing, the whole is cooled to about 33 C. and this emulsion is filtered and cast.
• portions of emulsion are continuously or intermittently withdrawn from the ripening operation in such a manner that at the beginning of the ripening small portions and towards the end of the ripening large portions are withdrawn, highly sensi-- tlve ortho-chromatic photographic layers having gradation curves of particular technical value are obtained.
• Process 0! making photographic silver halide gelatlne emulsions by mixing the components necessary for the preparation 01' the emulsions and ripening the emulsions, consisting in withdrawing during the ripening of the silver halide gelatine emulsion several portions thereof, 01' different degrees of ripeness, into a common vessel, the withdrawal of the several portions being efle'cted at short intervals 0! time.

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• Chemical & Material Sciences (AREA)
• Crystallography & Structural Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Colloid Chemistry (AREA)
• Silver Salt Photography Or Processing Solution Therefor (AREA)
• Chemical Treatment Of Metals (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=4514878

Family Applications (1)

Country Status (5)

Cited By (4)

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• 0
  • BE BE400237D patent/BE400237A/xx unknown
  • FR FR767458D patent/FR767458A/fr not_active Expired
• 1932
  • 1932-12-13 DE DEG84281D patent/DE619238C/de not_active Expired
• 1933
  • 1933-12-08 US US701531A patent/US2029946A/en not_active Expired - Lifetime
  • 1933-12-09 GB GB34700/33A patent/GB428305A/en not_active Expired

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