US2604397A - Chemical sensitization of photographic emulsions - Google Patents
Chemical sensitization of photographic emulsions Download PDFInfo
- Publication number
- US2604397A US2604397A US60816A US6081648A US2604397A US 2604397 A US2604397 A US 2604397A US 60816 A US60816 A US 60816A US 6081648 A US6081648 A US 6081648A US 2604397 A US2604397 A US 2604397A
- Authority
- US
- United States
- Prior art keywords
- emulsion
- silver halide
- emulsions
- sulfoxalate
- silver
- 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.)
- Expired - Lifetime
Links
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
- G03C1/06—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein with non-macromolecular additives
- G03C1/08—Sensitivity-increasing substances
- G03C1/10—Organic substances
-
- 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
- G03C7/00—Multicolour photographic processes or agents therefor; Regeneration of such processing agents; Photosensitive materials for multicolour processes
- G03C7/26—Silver halide emulsions for subtractive colour processes
Definitions
- This invention relates to photographic emu1 sions and more particularly to chemical sensitizers therefor.
- silver halide emulsions may be chemically sensitized with a variety of materials so as to increase the speed and generally the gamma of the emulsion as opposed to :optical sensitization in which the optical 'range of sensitivity is increased'
- chemical sensitization results in either the formation of silver sulfide on the surface of the silver halide crystal thus increasing sensitivity or the formation of small amounts of silver from the reduction of silver halide.
- present invention is concerned'with chemical sensitization apparently of the latter type.
- one-object ofour invention is to provide novel chemicallysensitized emulsions. Another objectis' to provide silver halide emulsions containing sulfoxalate sensitizing as well as sensitivity due to otherchefnical and optical sensitizers. Other objects will appear from the following description of'o'ur-invention.
- the objects of our invention areyaccomplished by incorporating into photographic emulsions a water-soluble formaldehyde sulfoxalate salt such as an alkali metalformaldehydevsulfoxalateparticularly sodium formaldehyde sulfoxalate.
- a water-soluble formaldehyde sulfoxalate salt such as an alkali metalformaldehydevsulfoxalateparticularly sodium formaldehyde sulfoxalate.
- the novel sensitizers are incorporated in' the emulsions at any stage in their preparation but'pr-eferably before digestion is complete. Generally in order to obtain the optimum sensitizingefiect we heat the emulsion after addition of the sulfoxalate sensitizer.
- the sensitizers may be used in conjunction with other cheinical-a'ndoptical sensitizers such as the Well known sulfur sensitizing c'ompoundsy'for example, those disclosed in Sheppard U. S. Patents"1,574,'94l granted March 2, 1926, and 1523,499, granted April 5, 1927, and may be employed before, after or'simultaneously with such sulfur sensitizing and in conjunction with sensitizing dyes.
- Als o our lnovel sensitizers areuseful with a variety of emulsions producing pronounced speed increases in either negative orpositive typ'e's of emulsions;
- the emulsion was cooled to 100 F. and the pH raised to 6.0 with sodium hydroxide solution.
- hydrophilicf colloid material such as gelatin or polyvinyl alcohol; respectively, and after addition .of the usual emulsion addenda, the emulsions were coated andfdried in the usual manner. After exposure in an Eastman TXDeiZB Sensitometer (J. Soc. Mot. Pict. Eng. '1??- (1931) p.
- Example 2 100 cc. of the same type of emulsion as'was used in Example 1 but which hadpreviously. been sensitized with arsulfur type of sensitizer e. g. allyl thiourea, .asdescribed in the Lowe et al. in-
- Example 1 was adjusted to pH 4.5 by dilute acetic acid and treated with sodium formaldehyde sulfoxalate as in Example 1 and samples combined with gelatin and polyvinyl alcohol, respectively, to obtain emulsions the sensitivities of which are distinctly higher than obtained by "using either .sensitizer separately as is shown in the table following (samples D and'H compared to samplesB. C;FandG).r
- Example 3 100 cc. of emulsion prepared as described in Example 2 (sensitized with: sulfur and sulfoxalate sens'itizersl were precipitated withidilute sulfuric acid and washedtwice with'distilled water. After repeptizing the grains, the pH was adjusted to 6.0, the emulsion heated to 120 F. and 1.0 mg. of potassium auric chloride Was added. After five minutes the temperature was lowered to 100 F., the emulsion was added to gelatin and coated and dried as usual. Thecharacteristics of this emulsion having combined sulfur, sulfoxalate and gold sensitizing, are shown in the table (sample K compared to samples I, J and L).
- a light-sensitive photographic emulsion comprising silver halide and from about 0.03 to 0.75 gram per kilogram of-silver nitrate used in .making the emulsion and converted to silver halide, of a water-soluble formaldehyde sulfoxalate salt as a sensitizing agent.
- sulfoxalate sensitizer incorporated into an emulsion may, depending upon the type of emulsion used, vary somewhat from the optimum amount employed in the above examples, one-fifth to five times as much sensitizer producing emulsion of useful sensitivity that is, from about 0.03 to 0.75 gram of the sensitizer per kilogram of silver nitrate used in making the emulsion and converted to silver halide. Less V heating is usually required when the larger amounts are employed and conversely, when using the smaller quantities of sensitizer.
- the novel sensitizers may, in general, be employed i emulsions containing hydrophilic colloid vehicles; for example, gelatin, polyvinyl alcohol, partially hydrolized cellulose esters and co-polymers of polyvinyl alcohol.
- hydrophilic colloid vehicles for example, gelatin, polyvinyl alcohol, partially hydrolized cellulose esters and co-polymers of polyvinyl alcohol.
- the ratio of colloid to silver halide present during digestion is not critical in this type of sensitizing since the digestion conditions can be readily adjusted as is well known in the art of sulfur sensitizing.
- the sensitizers are suitable for the well known types of silver chloride, silver bromide and silver iodide emulsions and emulsions containing mixtures of these halides.
- the emulsions may contain the usual addenda including antifoggants, spreading agents, coupler compounds, etc.
- Such emulsions are adaptable to use informing single as well as multi-layer films useful in color photography which customarily include two or more emulsion layers on a support sensitized to different regions of the visible spectrum and may or may not contain coupler compounds.
- color films carry at least one emulsion layer containing a sulfoxalate salt sensitizing agent.
- a light-sensitive photographic emulsion comprising silver halide and from about 0.03 to 0.75 gram per kilogram of silver nitrate used in making the emulsion and converted to silver halide, of sodium formaldehyde sulfoxalate as a sensitizing agent.
- a light-sensitive photographic emulsion comprising sulfur sensitized silver halide and from about 0.03 to 0.75 gram per kilogram of silver nitrate used in making the emulsion and converted to silver halide, of sodium formaldehyde sulfoxalate as an additional sensitizing agent.
- a light-sensitive photographic emulsion comprising silver halide sensitized with a sulfur sensitizing compound, a gold salt sensitizer and sodium formaldehyde sulfoxalate.
- a light-sensitive photographic emulsion comprising silver halide uniformly dispersed in a hydrophilic colloid vehicle and sensitized with from about 0.03 to 0.75 gram per kilogram of silver nitrate used in making the emulsion and converted to silver halide, of a water-soluble formaldehyde sulfoxalate salt.
- a light-sensitive photographic emulsion comprising silver halide uniformly dispersed in gelatin and sensitized with from about 0.03 to 0.75 gram per kilogram of silver nitrate used in making the emulsion and converted to silver halide, of sodium formaldehyde sulfoxalate.
- a light-sensitive photographic emulsion comprising silver halide uniformly dispersed in polyvinyl alcohol and sensitized with from about 0.03 to 0.75 gram per kilogram of silver nitrate used in making the emulsion and converted to silver halide, of sodium formaldehyde sulfoxalate.
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- Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- General Physics & Mathematics (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Silver Salt Photography Or Processing Solution Therefor (AREA)
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
BE492187D BE492187A (fr) | 1948-11-18 | ||
US60816A US2604397A (en) | 1948-11-18 | 1948-11-18 | Chemical sensitization of photographic emulsions |
FR999692D FR999692A (fr) | 1948-11-18 | 1949-11-17 | Procédé de sensibilisation des émulsions photographiques et produits en résultant |
GB29567/49A GB663020A (en) | 1948-11-18 | 1949-11-18 | Improvements in sensitive photographic emulsions |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US60816A US2604397A (en) | 1948-11-18 | 1948-11-18 | Chemical sensitization of photographic emulsions |
Publications (1)
Publication Number | Publication Date |
---|---|
US2604397A true US2604397A (en) | 1952-07-22 |
Family
ID=22031929
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US60816A Expired - Lifetime US2604397A (en) | 1948-11-18 | 1948-11-18 | Chemical sensitization of photographic emulsions |
Country Status (4)
Country | Link |
---|---|
US (1) | US2604397A (fr) |
BE (1) | BE492187A (fr) |
FR (1) | FR999692A (fr) |
GB (1) | GB663020A (fr) |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1763533A (en) * | 1923-11-27 | 1930-06-10 | Agfa Ansco Corp | Process for hardening colloids |
US2059817A (en) * | 1934-09-27 | 1936-11-03 | Eastman Kodak Co | Hardening photographic gelatin emulsions and solutions |
GB496049A (en) * | 1937-04-19 | 1938-11-21 | Ig Farbenindustrie Ag | Improved manufacture of light-sensitive photographic preparations |
-
0
- BE BE492187D patent/BE492187A/xx unknown
-
1948
- 1948-11-18 US US60816A patent/US2604397A/en not_active Expired - Lifetime
-
1949
- 1949-11-17 FR FR999692D patent/FR999692A/fr not_active Expired
- 1949-11-18 GB GB29567/49A patent/GB663020A/en not_active Expired
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1763533A (en) * | 1923-11-27 | 1930-06-10 | Agfa Ansco Corp | Process for hardening colloids |
US2059817A (en) * | 1934-09-27 | 1936-11-03 | Eastman Kodak Co | Hardening photographic gelatin emulsions and solutions |
GB496049A (en) * | 1937-04-19 | 1938-11-21 | Ig Farbenindustrie Ag | Improved manufacture of light-sensitive photographic preparations |
Also Published As
Publication number | Publication date |
---|---|
BE492187A (fr) | |
GB663020A (en) | 1951-12-12 |
FR999692A (fr) | 1952-02-04 |
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